East African Publishers, Ltd.

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Serum acid phosphatase was measured in patients with enlarged benign and malignant prostate before and after rectal examination. Amongst the patients with benign glands, rectal examination did not produce any significant false elevation of the enzyme. Rectal examination, however, caused a rise in the enzyme level in a few untreated cancer patients and in cancer patients who has become refractory to hormonal therapy. This rise would help rather than mislead in the diagnosis of malignant prostate and also in the identifying treated patients who had become refractory to treatment. Thus, when serum acid phosphatase is properly determined, elevated levels should always arouse suspicion of malignant prostate or other lesions associated with high enzyme level even is such determination was preceded by rectal examination. There appears to be no merit in the teaching that the determination of serum acid phosphatase should be delayed after rectal examination.

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A study that devised a modified method of reporting antibiotic sensitivity results was undertaken. Enterobacteriaceae and Gram positive cocci were tested for drug sensitivity by a disc diffusion method. Zones of bacterial growth inhibition were measured, dividing the isolates into four groups: the highly sensitive, the moderately sensitive, the slightly sensitive and the resistant ones. The slightly sensitive isolates were taken as indicators of antibiotic resistance acquisition. By that system, when more than 50% of the isolates fell into the slightly and resistant groups, that meant that the antibiotic concerned would be discontinued for some time until the bacteria reverted to being moderately sensitive. The study also provided a method of making antibiotic discs from local blotting papers, and a sample of a form on which antibiotic sensitivity results could be recorded was presented. The method is considered to be easy and very appropriate for developing countries in detecting gradual and abrupt acquisition of antibiotic resistance by bacteria.

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This paper investigates the possibilities of applying emerging management theories and techniques to constitutionally created offices in Kenya and East African region. The benefits from application of these theories, particularly in the judicial services are highlighted.

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Experimentally, two hydatid cyst fluid (HCF) antigens (antigens 4 and 5) were found to be the most immunogenic antigens in HCF.  The two antigens were precipitated together from HCF.  This was done by adding 2M phosphotungstic acid and 2M magnesium chloride pollutions to clarified HCF whilte continuously stirring the mixture.  The precipitate formed was suspend in physiological saline (PS).  This antigens solutions was used to coat microtitre plates fro indirect ELISA.  Indirect ELISA was performed on 180 randomly selected bovine sera. The sensitivity of the test was found to be 98% while the specificity was 70%.  The predictive value was 89%.  Although the specificity of the test was relatively low, the test using these partially purified antigens was found to be useful because of its high sensitivity.

Antisera to thermostable muscle antigens from 13 wild animals: Buffalo, Waterbuck, Bushbuck, Eland, Oryx, Kongoni, Bushpig, Warthog, Topi, Thomson’s gazelle, Grant’s gazelle, Sheep, Pig, Horse, Camel & Dog, were raised in rabbits and/or goats. Absorptions of the antisera with copolymerized pooled serum from the 20 species and the thermostable muscle antigens rendered most of the antisera mmonospecific. It was possible to identify the species of origin of saline extracts of both cooked and fresh meat samples in immunodiffusion tests. The method is promising for use in identification of the species origin of fresh and cooked animal meats.

A study that devised a modified method of reporting antibiotic sensitivity results was undertaken. Enterobacteriaceae and Gram positive cocci were tested for drug sensitivity by a disc diffusion method. Zones of bacterial growth inhibition were measured, dividing the isolates into four groups: the highly sensitive, the moderately sensitive, the slightly sensitive and the resistant ones. The slightly sensitive isolates were taken as indicators of antibiotic resistance acquisition. By that system, when more than 50% of the isolates fell into the slightly and resistant groups, that meant that the antibiotic concerned would be discontinued for some time until the bacteria reverted to being moderately sensitive. The study also provided a method of making antibiotic discs from local blotting papers, and a sample of a form on which antibiotic sensitivity results could be recorded was presented. The method is considered to be easy and very appropriate for developing countries in detecting gradual and abrupt acquisition of antibiotic resistance by bacteria.

A study that devised a modified method of reporting antibiotic sensitivity results was undertaken. Enterobacteriaceae and Gram positive cocci were tested for drug sensitivity by a disc diffusion method. Zones of bacterial growth inhibition were measured, dividing the isolates into four groups: the highly sensitive, the moderately sensitive, the slightly sensitive and the resistant ones. The slightly sensitive isolates were taken as indicators of antibiotic resistance acquisition. By that system, when more than 50% of the isolates fell into the slightly and resistant groups, that meant that the antibiotic concerned would be discontinued for some time until the bacteria reverted to being moderately sensitive. The study also provided a method of making antibiotic discs from local blotting papers, and a sample of a form on which antibiotic sensitivity results could be recorded was presented. The method is considered to be easy and very appropriate for developing countries in detecting gradual and abrupt acquisition of antibiotic resistance by bacteria.

A study that devised a modified method of reporting antibiotic sensitivity results was undertaken. Enterobacteriaceae and Gram positive cocci were tested for drug sensitivity by a disc diffusion method. Zones of bacterial growth inhibition were measured, dividing the isolates into four groups: the highly sensitive, the moderately sensitive, the slightly sensitive and the resistant ones. The slightly sensitive isolates were taken as indicators of antibiotic resistance acquisition. By that system, when more than 50% of the isolates fell into the slightly and resistant groups, that meant that the antibiotic concerned would be discontinued for some time until the bacteria reverted to being moderately sensitive. The study also provided a method of making antibiotic discs from local blotting papers, and a sample of a form on which antibiotic sensitivity results could be recorded was presented. The method is considered to be easy and very appropriate for developing countries in detecting gradual and abrupt acquisition of antibiotic resistance by bacteria.

PIP: In 1990, the annual population growth rate in Kenya was 3.8%, among the highest rates world wide. The ever growing adolescent fertility rate (111-152/1000 from 1969-1989) contributed to this rapid growth. Further repeat pregnancies among adolescents remained high in the 1980's and ranged from 20%-28.6%, depending on the survey. Even though overall prevalence of pregnancy fell 15.4% between 1978-1984, it remained the same for the 15-19 year old group. Teenage births have made up at least 35% of total deliveries. 1985 data revealed that even though adolescents represent 11-35% of the total obstetric population, problems ranked high among them: 38% of all eclampsia cases and high maternal mortality (102/100,000 vs. 57/100,000 older mothers). Studies showed that adolescents are sexually active, are ignorant about contraception, and do not use contraception. Yet contraceptive and family planning services are free in Kenya. Nevertheless the teenagers are at high risk of an unwanted pregnancy, sexually transmitted diseases (STDs), and AIDS. In the early 1980s, Kenyatta National Hospital reported 53% of 74.1% of septic abortion cases being single women were between 14-20 years old. Similar results emerged from other studies. Health professionals believed these results to be underestimated, however. In the 1980s, 33% of all adolescents between 13-15 years old in a rural area had gonorrhea. In Kenyatta, 36% of pregnant 15-24 year olds had at least 1 STD while,e only 16% of those 24 years old did. Further, teenagers are especially vulnerable to psychological problems when they 1st learn of their pregnancy. Health services should be geared to meet the specific needs of adolescents, such as contraception education and antenatal services. PMID: 12316815 [PubMed - indexed for MEDLINE]

PIP: In 1990, the annual population growth rate in Kenya was 3.8%, among the highest rates world wide. The ever growing adolescent fertility rate (111-152/1000 from 1969-1989) contributed to this rapid growth. Further repeat pregnancies among adolescents remained high in the 1980's and ranged from 20%-28.6%, depending on the survey. Even though overall prevalence of pregnancy fell 15.4% between 1978-1984, it remained the same for the 15-19 year old group. Teenage births have made up at least 35% of total deliveries. 1985 data revealed that even though adolescents represent 11-35% of the total obstetric population, problems ranked high among them: 38% of all eclampsia cases and high maternal mortality (102/100,000 vs. 57/100,000 older mothers). Studies showed that adolescents are sexually active, are ignorant about contraception, and do not use contraception. Yet contraceptive and family planning services are free in Kenya. Nevertheless the teenagers are at high risk of an unwanted pregnancy, sexually transmitted diseases (STDs), and AIDS. In the early 1980s, Kenyatta National Hospital reported 53% of 74.1% of septic abortion cases being single women were between 14-20 years old. Similar results emerged from other studies. Health professionals believed these results to be underestimated, however. In the 1980s, 33% of all adolescents between 13-15 years old in a rural area had gonorrhea. In Kenyatta, 36% of pregnant 15-24 year olds had at least 1 STD while,e only 16% of those 24 years old did. Further, teenagers are especially vulnerable to psychological problems when they 1st learn of their pregnancy. Health services should be geared to meet the specific needs of adolescents, such as contraception education and antenatal services. PMID: 12316815 [PubMed - indexed for MEDLINE]

coming soon at the webstie

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Self-limited noncardiogenic interstitial pulmonary edema probably reflecting altered permeability of the pulmonary capillary membrane is reported in a patient being treated for severe diabetic ketoacidosis. The possible etiology, associated findings, and therapy with continuous positive airway pressure (CPAP) by facemask are discussed.

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The characteristics of light scattering of cell suspensions in norm (pH 7,2, t=20degreesC) and upon external influences (change of pH and increase of tdegree). The turbidity tauapproximatelylambda-n and n=0,2--0,3 for cells in norm. After cell damage n increases. Dependence of n correlates with the increase of some injured cells determined by eozin test. Alterations of light scattering after cell damage were connected with the increase of deposit of intercellular structure in general scattering.

It has been established that H+ secretion can be maintained in frog stomach in the absence of exogenous CO2 by using a nutrient bathing fluid containing 25 mM H2PO4 (pH approximately equal to 4.5) or by lowering the pH of a nonbuffered nutrient solution to about 3.0-3.6. Exogenous CO2 in the presence of these nutrient solutions uniformly caused a marked decrease in H+ secretion, PD, adn short-circuit current (Isc) and an increase in transmucosal resistance (R). Elevation of nutrient [k+] to 83 mM reduced R significantly but transiently without change in H+ when nutrient pH less than 5.0, whereas R returned to base line and H+ increased when nutrient pH greater than 5.0. Acidification of the nutrient medium in the presence of exogenous CO2 results in inhibition of the secretory pump, probably by decreasing intracellular pH, and also interferes with conductance at the nutrient membrane. Removal of exogenous CO2 from standard bicarbonate nutrient solution reduced by 50% the H+, PD, and Isc without change in R; K+-free nutrient solutions reverse these changes in Isc and PD but not in H+. The dropping PD and rising R induced by K+-free nutrient solutions in 5% CO2 - 95% O2 are returned toward normal by 100% O2. Our findings support an important role for exogenous CO2 in maintaining normal acid-base balance in frog mucosa by acting as an acidifying agent.

The distribution of blood flow to the subendocardial, medium and subepicardial layers of the left ventricular free wall was studied in anaesthetized dogs under normoxic (A), hypoxic (B) conditions and under pharmacologically induced (etafenone) coronary vasodilation (C). Regional myocardial blood flow was determined by means of the particle distribution method. In normoxia a transmural gradient of flow was observed, with the subendocardial layers receiving a significantly higher flow rate compared with the subepicardial layers. In hypoxia induced vasodilation this transmural gradient of flow was persistent. In contrast a marked redistribution of regional flow was observed under pharmacologically induced vasodilation. The transmural gradient decreased. In contrast to some findings these experiments demonstrate that a considerable vasodilatory capacity exists in all layers of the myocardium and can be utilized by drugs. The differences observed for the intramural distribution pattern of flow under hypoxia and drug induced vasodilation support the hypothesis that this pattern reflects corresponding gradients of regional myocardial metabolism.

RMI 61 140, RMI 61 144 and RMI 61 280 are newly synthetized N-[8-R-dibenzo(b,f)oxepin-10-yl]-N'-methyl-piperazine-maleates which show interesting psychopharmacologic effects. This work contains the results of a study performed with these three compounds, in order to demonstrate their neuropsycholeptic activity in comparison with chloropromazine (CPZ) and chlordiazepoxide (CPD). The inhibition of motility observed in mice shows that the compounds reduce the normal spontaneous motility as well as the muscle tone. The central-depressant activity is evidenced by increased barbiturate-induced sleep and a remarkable eyelid ptosis can also be observed. Our compounds do not show any activity on electroshock just as do CPZ and CPD. As to the antipsychotic outline, our compounds show strong reduction of lethality due to amphetamine in grouped mice and a strong antiapomorphine activity. They show also an antiaggressive effect and an inhibitory activity on avoidance behaviour much stronger than CPZ. We have also found extrapyramidal effects, as catalepsy, common to many tranquillizers of the kind of the standards used by us. As for vegetative phenomena, the compounds show hypotensive dose related action ranging from moderate to strong, probably due to an a-receptor inhibition. Adrenolytic activity against lethal doses of adrenaline, antiserotonin and antihistaminic effects, as well as other actions (hypothermia, analgesia, etc.) confirm that RMI 61 140, RMI 61 144 and RMI 61 280 are endowed with pharmacologic properties similar and more potent than those of CPZ. Studies on the metabolism of brain catecholamines show that they are similar to CPZ, although with less effect on dopamine level.

RMI 61 140, RMI 61 144 and RMI 61 280 are newly synthetized N-[8-R-dibenzo(b,f)oxepin-10-yl]-N'-methyl-piperazine-maleates which show interesting psychopharmacologic effects. This work contains the results of a study performed with these three compounds, in order to demonstrate their neuropsycholeptic activity in comparison with chloropromazine (CPZ) and chlordiazepoxide (CPD). The inhibition of motility observed in mice shows that the compounds reduce the normal spontaneous motility as well as the muscle tone. The central-depressant activity is evidenced by increased barbiturate-induced sleep and a remarkable eyelid ptosis can also be observed. Our compounds do not show any activity on electroshock just as do CPZ and CPD. As to the antipsychotic outline, our compounds show strong reduction of lethality due to amphetamine in grouped mice and a strong antiapomorphine activity. They show also an antiaggressive effect and an inhibitory activity on avoidance behaviour much stronger than CPZ. We have also found extrapyramidal effects, as catalepsy, common to many tranquillizers of the kind of the standards used by us. As for vegetative phenomena, the compounds show hypotensive dose related action ranging from moderate to strong, probably due to an a-receptor inhibition. Adrenolytic activity against lethal doses of adrenaline, antiserotonin and antihistaminic effects, as well as other actions (hypothermia, analgesia, etc.) confirm that RMI 61 140, RMI 61 144 and RMI 61 280 are endowed with pharmacologic properties similar and more potent than those of CPZ. Studies on the metabolism of brain catecholamines show that they are similar to CPZ, although with less effect on dopamine level.

A double-blind study with intra-individual comparisons was carried out to investigate the effects of 15 mg of (8r)-3alpha-hydroxy-8-isopropyl-1alphaH-tropanium bromide(+/-)-tropate (Sch 1000), 15 mg Sch 1000 + 10 mg oxazepam, 10 mg oxazepam and placebo with oral administration in randomized sequence on gastric juice volume, amount of acid, concentration and pH values in 12 healthy volunteers. The secretion parameters were measured during a 1-h basal period and a 2-h stimulation period. The gastric juice was obtained in 15 min portions via stomach tube. Stimulation was effected by 1 mug/kg/h pentagastrin via drip infusion. The Friedman test was used for the comparative statistical evaluation, and individual comparisons were carried out by means of the Wilcoxon test (pair-differences rank). The results show that Sch 1000 and Sch 1000 + oxazepam were equal in effect on basal and stimulated secretion volume. As compared with placebo, it was not possible to establish an effect on secretion volume for oxazepam alone. Sch 1000 and Sch 1000 + oxazepam were found to be equipotent in reducing the amount of basal acid, while oxazepam reduced this quantity only during the first 30 min of basal secretion. None of the three active preparations was capable of inhibiting the stimulated acid, although both Sch 1000 preparations produced a clear trend towards lowered mean values. During the basal secretion period, all three test preparations had an inhibiting action on acid concentration, but none of them had a significant effect during the stimulation period. The pH value was savely increased only by Sch 1000 and Sch 1000 + oxazepam, and this even only during the basal period. The results are discussed.

A new haemoglobin with increased oxygen affinity, beta82 (EF6) lysine leads to threonine (Hb Rahere), was found during the investigation of a patient who was found to have a raised haemoglobin concentration after a routine blood count. The substitution affects one of the 2, 3-diphosphoglycerate binding sites, resulting in an increased affinity for oxygen, but both the haem-haem interaction and the alkaline Bohr effect are normal in the haemolysate. This variant had the same mobility as haemoglobin A on electrophoresis at alkaline pH but was detected by measuring the whole blood oxygen affinity; it could be separated from haemoglobin A, however, by electrophoresis in agar at acid pH. The raised haemoglobin concentration was mainly due to a reduction in plasma volume (a relative polycythaemia) and was associated with a persistently raised white blood count. This case emphasises the need to measure the oxygen affinity of haemoglobin in all patients with absolute or relative polycythaemia when some obvious cause is not evident.

Five distinct ester hydrolases (EC 3-1) have been characterized in guinea-pig epidermis. These are carboxylic esterase, acid phosphatase, pyrophosphatase, and arylsulphatase A and B. Their properties are consistent with those of lysosomal enzymes.

The helix to coil transition of poly(L-glutamic acid) was investigated in 0.05 and 0.005 M aqueous potassium chloride solutions by use of potentiometric titration and circular dichroism measurement. Polymer concentration dependence of the transition was observed in the range from 0.006 to 0.04 monomol/e in 0.005 M KG1 solution. The polymer concentration dependence can be interpreted by current theories of the transition of charged polypeptides and of titration curves of linear weak polyelectrolytes taking the effect of polymer concentration into consideration.

Dental anomalies were observed in 43 of 1,226 barren-ground caribou (Rangifer tarandus groenlandicus) taken between 1966 and 1968. In five of these 43 animals, the mandibles had deformities which radiography showed to be the result of dental abscesses in four cases and probably of a trauma in the other. The absence of actinomycotic lesions of the jaw bones of these 1,226 animals, and of more than 500 examined previously, indicates that "lumpy jaw" is rare in barren-ground caribou. The authors suggest the use of radiography to determine the nature of bone growth on skeletal remains, in the absence of soft tissues for examination for Actinomyces, either microscopically or by cultural methods.

The 24-hr LD50 of colchicine in newborn rats is 0.24 mg/kg, which is about 1/10 that observed in the adult. The 24-hr LD50 of colchicine was relatively constant in rats over 25 days of age. In an attempt to determine the mechanism of the increased sensitivity of the newborn rat to the toxic action of colchicine, the distribution of 3H after the administration of 3H-colchicine (0.1 mg/kg) was measured in 10- and 35-day-old rats. The concentration of 3H was higher in all tissues of the newborn than the adult after ip administration, suggesting an immaturity in the pathway for colchicine elimination. After iv administration, radioactivity disappeared much more slowly from the plasma of the newborn rat than from the adult. This was due to a lower capacity of the liver of the newborn to concentrate colchicine and to excrete it into the bile. Development of the hepatic excretory mechanism responsible for excretion of colchicine occurred at the same age as did the increase in LD50. These results suggest that colchicine is more toxic in the newborn because the drug remains in the body for a longer time due to immaturity of the liver excretory process.

A single exposure to a severe stressor (either cold swim or inescapable shock) impairs subsequent performance in a shuttle avoidance-escape task (1), a deficit attributed to reduction in brain noradrenergic activity produced by these stressors. In the present paper, two experiments are described which examine how repeated exposure to such stressors affects (a) shuttle avoidance-escape performance (Experiment 1), and (b) aspects of brain norepinephrine metabolism (Experiment 2). Experiment 1 showed that, whereas subjects receiving the single exposure to cold swim or shock showed a large avoidance-escape deficit, subjects that received repeated exposure to these stressors for 14 days performed similarly to the control group that received no stressor. Experiment 2 showed that, whereas subjects that received one session of the inescapable shock stressor showed a lower level of norepinephrine in hypothalamus and cortex than did subjects that received no shock, subjects that received repeated exposure to inescapable shock or cold swim showed neurochemical "habituation." Subjects that received repeated shock showed elevated tyrosine hydroxylase activity and no depletion of norepinephrine level, and both repeated shock and cold swim caused a decrease in uptake of 3H-norepinephrine by slices of cortex in vitro. Thus, it is concluded that the behavioral and neurochemical changes that were observed after the stressful conditions studied are consistent with the hypothesis that changes in avoidance-escape responding following exposure to these stressful events are due to changes in brain noradrenergic activity.

1. Crude extracts and partially purified enzyme preparations from potato tubers catalyse, at pH 5-7, the conversion of linoleic acid hydroperoxides to a range of oxygenated fatty acid derivatives. 2. 9-D- and 13-L-hydroperoxide isomers are converted at similar rates to equivalent (isomeric) products. 3. The major products from the 13-hydroperoxide isomer were identified as the corresponding monohydroxydienoic acid derivative, threo-11-hydroxy-trans12,13-epoxy-octadec-cis9-enoic acid and 9,12,13-trihydroxy-octadec-trans10-enoic acid. The corresponding products from the 9-hydroperoxide were the monohydroxydienoic acid, 9,10-epoxy-11-hydroxy-octadec-12-enoic acid and 9,10,13-trihydroxy-octadec-11-enoic acid. 4. No separation of activities forming the different products was achieved by partial purification of enzyme extracts. 5. Product formation was unaffected by EDTA, CN-, sulphydryl reagents or glutathione but was reduced by boiling the extracts. 6. This system is compared with the 9-hydroperoxide-specific enzymic formation of divinyl ether derivatives by potato extracts.

The hydrolysis of p-nitrophenyl phosphate by wheat germ acid phosphatase (orthophosphoric monoester phosphohydrolase, EC 3.1.3.2) has been investigated in mixtures of aqueous buffers with acetone, dioxane and acetonitrile. The enzyme was either in free solution or immobilized on a pellicular support which consisted of a porous carbonaceous layer on solid glass beads. The highest enzyme activity was obtained in acetone and acetonitrile mixed with citrate buffer over a wide range of organic solvent concentration. In 50% (v/v) acetone both V and Km of the immobilized enzyme were about half of the values in the neat aqueous buffer, but the Ki for inorganic phosphate was unchanged. In 50% (v/v) mixtures of various solvents and citrate buffers of different pH, the enzymic activity was found to depend on the pH of the aqueous buffer component rather than the pH of the hydro-organic mixture as measured with the glass-calomel electrode. The relatively high rates of p-nitrophenol liberation in the presence of glucose even at high organic solvent concentrations suggest that transphosphorylation is facilitated at low water activity.

The characterization and localization of a Ca(2+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) in the tooth germ of the porcine fetus are reported. This enzyme, a microsome fraction, is preferentially activated by Ca(2+). In the presence of 0.5 mM ATP, maximal enzyme activity is obtained at 0.5--1.0 mM CaCl2. The maximal rate of ATP hydrolysis is approx. 20 mumol per h per mg of protein as the enzyme preparation is used here. At optimal Ca(2+) concentration, the Mg(2+) has an inhibitory effect. The enzyme does not require Na+ or/and K+ for activation by Ca(2+). Other nucleotide triphosphates may serve as the substrate, but V for ATP is the highest. The Km for ATP is 8.85 - 10(-5) M. The optimal pH for Ca(2+) activation of the enzyme lies around 9.2. Well known inhibitors of (Na+ + K+)-ATPase, mitochondria ATPase and Ca(2+)-ATPase in the erthrocyte do not inhibit the enzyme. In the subcellular order the enzyme may be assumed to be localized in the smooth endoplasmic reticulum fraction containing cell and Golgi body membrane fragments and in the tissue order in the enamel organ containing an ameloblast layer, stratum intermedium and stellate reticulum.

The phosphorylated form of liver glycogen phosphorylase (alpha-1,4-glucan : orthophosphate alpha-glucosyl-transferase, EC 2.4.1.1) (phosphorylase a) is active and easily measured while the dephosphorylated form (phosphorylase b), in contrast to the muscle enzyme, has been reported to be essentially inactive even in the presence of AMP. We have purified both forms of phosphorylase from rat liver and studied the characteristics of each. Phosphorylase b activity can be measured with our assay conditions. The phosphorylase b we obtained was stimulated by high concentrations of sulfate, and was a substrate for muscle phosphorylase kinase whereas phosphorylase a was inhibited by sulfate, and was a substrate for liver phosphorylase phosphatase. Substrate binding to phosphorylase b was poor (KM glycogen = 2.5 mM, glucose-1-P = 250 mM) compared to phosphorylase a (KM glycogen = 1.8 mM, KM glucose-1-P = 0.7 mM). Liver phosphorylase b was active in the absence of AMP. However, AMP lowered the KM for glucose-1-P to 80 mM for purified phosphorylase b and to 60 mM for the enzyme in crude extract (Ka = 0.5 mM). Using appropriate substrate, buffer and AMP concentrations, assay conditions have been developed which allow determination of phosphorylase a and 90% of the phosphorylase b activity in liver extracts. Interconversion of the two forms can be demonstrated in vivo (under acute stimulation) and in vitro with little change in total activity. A decrease in total phosphorylase activity has been observed after prolonged starvation and in diabetes.

Enzymes capable of hydrolyzing esters of thiocholine have been assayed in extracts of Solanum melongena L. (eggplant) and Zea Mays L. (corn). The enzymes from both species are inhibited by the anti-cholinesterases neostigmine, physostigmine, and 284c51 and by AMO-1618, a plant growth retardant and they both have pH optima near pH 8.0. The enzyme from eggplant is maximally active at a substrate concentration of 0.15 mM acetylthiocholine and is inhibited at higher substrate concentrations. On the basis of this last property, the magnitude of inhibition by the various inhibitors, and the substrate specificity, we conclude that the enzyme from eggplant, but not that from corn, is a cholinesterase.

A purification procedure for creatine kinase (EC 2.7.3.2) from muscle of the monke35--170 muequiv H+/mg protein per min at 30 degrees C and a yield of approx. 0.5 g/kg muscle. Assuming equilibrium kinetics, synergistic binding of substrates at one catalytic site is found for both the forward and back reactions. Kinetic constants for the binding of each substrate to the free enzyme and the enzyme-second substrate complex are determined and are compared with those for the enzyme from other species. Inhibition by small anions is determined in the presence of different combinations of substrates and products. SO4(2-) inhibits by simple competitive inhibition and probably binds at the site of the transferrable phosphoryl group. Inhibition by NO3-, NO2-, SCN- and Cl- is more complex and these ions are suggested to mimic the transferrable phosphoryl group in a planar transition-state complex. These anions stabilize the dead-end complex, enzyme-creatine-MgADP, which lacks the transferable phosphoryl group. The effects of these anions on the dissociation constants of the enzyme-substrate complexes is reported and is in accord with the above hypothesis. The dead-end complex in the absence of anion does not protect the essential thiol group against inhibition by iodoacetamide. Addition of NO3- or Cl- to the dead-end complex or a substrate equilibrium mixture without anion confers protection. The essential thiol group is inhibited by iodoacetamide at a rate which is essentially independent of pH over the normal stability range of the enzyme. Contrary to our previous report this pH independence is not altered by the presence of dead-end complex, creatine plus MgADP, in the presence or absence of anion or in the presence of a substrate equilibrium mixture. It is inferred that the 'essential' thiol group of the monkey enzyme has essentially the same properties as that of the rabbit enzyme. In consequence, the inferences made about the role of this group based on our previous work on the monkey enzyme are no longer valid. The present findings are compatible with the essential thiol group playing a conformational role in the catalytic process.

Two rabbit erythrocyte casein kinases, GTP:casein kinase I and GTP:casein kinase II, have been purified 29 000- and 47 000-fold, respectively. Studies employing sucrose density gradient centrifugation indicate that kinase I has a molecular weight of about 9.5 - 10(5) (25 S) and kinase II about 1.4 - 10(6) (32 S). These enzymes can utilize either ATP or GTP as the phosphoryl donor. Among various protein substrates examined, these kinases catalyze the phosphorylation of casein greater than 50% dephosphorylated phosvitin congruent to 50% dephosphorylated casein greater than phosvitin. Histones, protamine and bovine serum albumin are poor phosphoryl acceptors. Kinetic data indicate that both enzymes are inhibited by high casein substrate concentrations which may be partially relieved by NaCl. Both phosphotransferases require Mg(2+) for activity and are optimally active at pH 9.0. The enzymes have apparent Km values of 2.5 - 10(-5) M for GTP, 2 - 10(-5) M for ATP, and 0.4--0.6 mg/ml for casein. The incorporation of the terminal phosphate of GTP into casein as catalyzed by these enzymes is inhibited to varying degrees by ATP, ITP, ADP, and GDP but not by UTP, CTP, GMP, adenosine 3':5'-cyclic monophosphate, and guanosine 3':5'-cyclic monophosphate. In addition, NaF and 2,3-diphosphoglyceric acid are also found to inhibit the activity of both kinases. The effect of 2,3-diphosphoglycerate is interesting and suggests that this metabolite may regulate the activity of the casein kinases in the red blood cells.

Two rabbit erythrocyte casein kinases, GTP:casein kinase I and GTP:casein kinase II, have been purified 29 000- and 47 000-fold, respectively. Studies employing sucrose density gradient centrifugation indicate that kinase I has a molecular weight of about 9.5 - 10(5) (25 S) and kinase II about 1.4 - 10(6) (32 S). These enzymes can utilize either ATP or GTP as the phosphoryl donor. Among various protein substrates examined, these kinases catalyze the phosphorylation of casein greater than 50% dephosphorylated phosvitin congruent to 50% dephosphorylated casein greater than phosvitin. Histones, protamine and bovine serum albumin are poor phosphoryl acceptors. Kinetic data indicate that both enzymes are inhibited by high casein substrate concentrations which may be partially relieved by NaCl. Both phosphotransferases require Mg(2+) for activity and are optimally active at pH 9.0. The enzymes have apparent Km values of 2.5 - 10(-5) M for GTP, 2 - 10(-5) M for ATP, and 0.4--0.6 mg/ml for casein. The incorporation of the terminal phosphate of GTP into casein as catalyzed by these enzymes is inhibited to varying degrees by ATP, ITP, ADP, and GDP but not by UTP, CTP, GMP, adenosine 3':5'-cyclic monophosphate, and guanosine 3':5'-cyclic monophosphate. In addition, NaF and 2,3-diphosphoglyceric acid are also found to inhibit the activity of both kinases. The effect of 2,3-diphosphoglycerate is interesting and suggests that this metabolite may regulate the activity of the casein kinases in the red blood cells.

Purified skeletal muscle myosin (EC 3.6.1.3) has been covalently bound to Sepharose 4B by the cyanogen bromide procedure. The resulting complex, Sepharose-Myosin, possesses adenosine triphosphatase activity and is relatively stable for long periods of time. Under optimal binding conditions, approximately 33% of the specific ATPase activity of the bound myosin is retained. Polyacrylamide gel electrophoresis of polypeptides released from denatured Sepharose-Myosin indicates that 85% of the myosin is attached to the agarose beads through the heavy chains and the remainder through the light chains, in agreement with predictions of binding and release based upon either the lysine contents or molecular weights of themyosin subunits. The adenosine triphosphatase of the immobilized myosin has been investigated under conditions of varying pH, ionic strength, and cation concentration. The ATPase profiles of immobilized myosin are quite similar to those for free myosin, however subtle differences are found. The Sepharose-Myosin ATPase is not as sensitive as myosin to alterations in salt concentration and the apparent KM is approximately two-fold higher than that of myosin. These differences are probably due to chemical modification in the region of the attachment site(s) to the agarose beads and hydration and diffusion limitations imposed by the polymeric agarose matrix.

A strain of Bacillus sp (Bacillus R-4) produces a protease and a carbohydrolase both of which have the ability to lyse Rhizopus cell walls. Of the enzymes, the carbohydrolase has been purified to an ultracentrifugally and electrophoretically homogeneous state, and identified as a chitosanase. The enzyme was active on glycol chitosan as well as chitosan. Molecular weight of the purified enzyme was estimated as 31 000 and isoelectric point as pH 8.30. The enzyme was most active at pH 5.6 and at 40 degrees C with either Rhizopus cell wall or glycol chitosan as substrate, and was stable over a range of pH 4.5 to 7.5 at 40 degrees C for 3 h. The activity was lost by sulfhydryl reagents and restored by either reduced glutathione of L-cysteine. An abrupt decrease in viscosity of the reaction mixture suggested an endowise cleavage of chitosan by this enzyme.

1. The pH dependencies of the apparent Michaelis constant for oxidized glutathione and the apparent turnover number of yeast glutathione reductase (EC 1.6.4.2) have been determined at a fixed concentration of 0.1 mM NADPH in the range pH 4.5--8.0. Between pH 5.5 and 7.6, both of these parameters are relatively constant. The principal effect of low pH on the kinetics of the enzyme-catalyzed reaction is the observation of a pH-dependent substrate inhibition by oxidized glutathione at pH less than or equal 7, which is shown to correlate with the binding of oxidized glutathione to the oxidized form of the enzyme. 2. The catalytic activity of yeast glutathione reductase at pH 5.5 is affected by the sodium acetate buffer concentration. The stability of the oxidized and reduced forms of the enzyme at pH 5.5 and 25 degrees C in the absence of bovine serum albumin was studied as a function of sodium acetate concentration. The results show that activation of the catalytic activity of the enzyme at low sodium acetate concentration correlates with an effect of sodium acetate on a reduced form of the enzyme. In contrast, inhibition of the catalytic activity of the enzyme at high sodium acetate concentration correlates with an effect of sodium acetate on the oxidized form of the enzyme.

1. The pH dependencies of the apparent Michaelis constant for oxidized glutathione and the apparent turnover number of yeast glutathione reductase (EC 1.6.4.2) have been determined at a fixed concentration of 0.1 mM NADPH in the range pH 4.5--8.0. Between pH 5.5 and 7.6, both of these parameters are relatively constant. The principal effect of low pH on the kinetics of the enzyme-catalyzed reaction is the observation of a pH-dependent substrate inhibition by oxidized glutathione at pH less than or equal 7, which is shown to correlate with the binding of oxidized glutathione to the oxidized form of the enzyme. 2. The catalytic activity of yeast glutathione reductase at pH 5.5 is affected by the sodium acetate buffer concentration. The stability of the oxidized and reduced forms of the enzyme at pH 5.5 and 25 degrees C in the absence of bovine serum albumin was studied as a function of sodium acetate concentration. The results show that activation of the catalytic activity of the enzyme at low sodium acetate concentration correlates with an effect of sodium acetate on a reduced form of the enzyme. In contrast, inhibition of the catalytic activity of the enzyme at high sodium acetate concentration correlates with an effect of sodium acetate on the oxidized form of the enzyme.

Theory is presented relating to the binding of an effector to two states of a protein acceptor coexisting in equilibrium. The problem is treated in terms of the four possible cases which specify relations between numbers of binding sites and intrinsic binding constants relevant to the acceptor states. It is shown that a distinction between these cases may be possible on the basis of the form of a plot of unbound effector concentration versus the constituent equilibrium coefficient which may be calculated from the sedimentation coefficient of the protein constituent. Particularly noteworthy in this respect is the finding that a turning point may exist in this plot for defined conditions with systems in which binding sites are not conserved (and binding affinities are altered) on polymer formation. The latter type of system is exemplified by studies on methaemoglobin A in 0.25 M sodium acetate, pH 5.4. In the absence of added organic phosphate effectors, a dimer-tetramer equilibrium operates governed by an association constant of 4.15 +/- 0.06 X 10(3) 1/mol, determined from sedimentation equilibrium results. Correlation of sedimentation velocity and equilibrium results shows that addition of adenosine 5'-triphosphate (ATP) results in its binding to one site on each of the dimeric (alpha beta) and tetrameric (alpha beta)2 species with intrinsic binding constants 1.03-10(3)-1.20-10(3) and 1.1-10(4)-2.1-10(4) 1/mol, respectively. It is also shown that 2,3-diphosphoglycerate perturbs the dimer-tetramer equilibrium in a similar way to ATP.

Choline acetyltransferase (EC 2.3.1.6) catalyzes the biosynthesis of acetylcholine according to the following chemical equation: acetyl-CoA + choline in equilibrium to acetylcholine + CoA. In addition to nervous tissue, primate placenta is the only other animal source which contains appreciable acetylcholine and its biosynthetic enzyme. Human brain caudate nucleus and human placental choline acetyltransferase were purified to electrophoretic homogeneity using ion-exchange and blue dextran-Sepharose affinity chromatography. The molecular weights determined by Sephadex G-150 gel filtration and sodium dodecyl sulfate gel electrophoresis are 67000 plus or minus 3000. N-Ethylmaleimide, p-chloromercuribenzoate, and dithiobis(2-nitrobenzoic acid) inhibit the enzyme. Dithiothreitol reverses the inhibition produced by the latter two reagents. The pKa of the group associated with N-ethylmaleimide inhibition is 8.6 plus or minus 0.3. A chemically competent acetyl-thioenzyme is isolable by Sephadex gel filtration. The enzymes from the brain and placenta are thus far physically and biochemically indistinguishable.

Primary amines react with 2,4-pentanedione at pH 6-9 to form enamines, N-alkyl-4-amino-3-penten-2-ones. The latter compounds readily regenerate the primary amine at low pH or on treatment with hydroxylamine. Guanidine and substituted guanidines react with 2,4-pentanedione to form N-substituted 2-amino-4,6-dimethylpyrimidines at a rate which is lower by at least a factor of 20 than the rate of reaction of 2,4-pentanedione with primary amines. Selective modification of lysine and arginine side chains in proteins can readily be achieved with 2,4-pentanedione. Modification of lysine is favored by reaction at pH 7 or for short reaction times at pH 9. Selective modification of arginine is achieved by reaction with 2,4-pentanedione for long times at pH 9, followed by treatment of the protein with hydroxylamine. The extent of modification of lysine and arginine side chains can readily be measured spectrophotometrically. Modification of lysozyme with 2,4-pentanedione at pH 7 results in modification of 3.8 lysine residues and less than 0.4 arginine residue in 24 hr. Modification of lysozyme with 2,4-pentanedione at pH 9 results in modification of 4 lysine residues and 4.5 arginine residues in 100 hr. Treatment of this modified protein with hydroxylamine regenerated the modified lysine residues but caused no change in the modified arginine residues. One arginine residue seems to be essential for the catalytic activity of the enzyme.

Human hemoglobin was spin labeled with 4-isothiocanato-2,2,6,6-tetramethyl-piperdinooxyl, which is known to bind specifically to the N-terminal alpha-amino groups of proteins and slightly to the reactive sulfhydryl groups. Electron spin resonance (ESR) analysis indicated a partially resolved five-line spectrum, suggesting that the label was attached to at least two different binding sites. Using specific blocking reagents prior to spin labeling, the two binding sites were attributed to the sulfhydryl group of beta-93 (immobile) and the alpha-amino group of the N-terminal valines (mobile). The relative motion of the spin at one set of binding sites was restricted regardless of the state of ligation and pH, while the motion at the other site showed dependence on those parameters, e.g. the spin-labeled N-terminal ends of deoxyhemoglobin have restricted motion at all pH ranges studied, while those of oxyhemoglobin are relatively free to move at the basic pH range, but become more restricted in the acidic pH range.

Poly(8-aminoguanylic acid) has in neutral solution a novel ordered structure of high stability. The 8-amino group permits formation of three hydrogen bonds between two residues along the "top", or long axis, of the purines. The usual hydrogen bonding protons and Watson-Crick pairing sites are not involved in the association. The bonding scheme has a twofold rotation axis and is hemiprotonated at N(7). Poly(8NH2G) is converted by alkaline titration (pK = 9.7) to a quite different ordered structure, which is the favored form over the range approximately pH 10-11. The bonding scheme appears to be composed of a planar, tetrameric array of guanine residues, in which the 8-amino group does not participate in interbase hydrogen bonding. Poly (8NH2G) does not interact with poly(C) in neutral solution because of the high stability of the hemiprotonated G-G self-structure. Titration to the alkaline plateau, however, permits ready formation of a two-stranded Watson-Crick helix. In contrast to the monomer 8NH2GMP, poly(8NH2G) does not form a triple helix with poly(C) under any conditions. The properties of the ordered structures are interpreted in terms of a strong tendency of the 8-amino group to form a third interbase hydrogen bond, when this possibility is not prevented by high pH.

Poly(8-aminoguanylic acid) has in neutral solution a novel ordered structure of high stability. The 8-amino group permits formation of three hydrogen bonds between two residues along the "top", or long axis, of the purines. The usual hydrogen bonding protons and Watson-Crick pairing sites are not involved in the association. The bonding scheme has a twofold rotation axis and is hemiprotonated at N(7). Poly(8NH2G) is converted by alkaline titration (pK = 9.7) to a quite different ordered structure, which is the favored form over the range approximately pH 10-11. The bonding scheme appears to be composed of a planar, tetrameric array of guanine residues, in which the 8-amino group does not participate in interbase hydrogen bonding. Poly (8NH2G) does not interact with poly(C) in neutral solution because of the high stability of the hemiprotonated G-G self-structure. Titration to the alkaline plateau, however, permits ready formation of a two-stranded Watson-Crick helix. In contrast to the monomer 8NH2GMP, poly(8NH2G) does not form a triple helix with poly(C) under any conditions. The properties of the ordered structures are interpreted in terms of a strong tendency of the 8-amino group to form a third interbase hydrogen bond, when this possibility is not prevented by high pH.

Increasing concentrations of chloride were found to increase the resolution between two visible absorbance spectral transitions associated with acidification of ferricytochrome c. Analysis of a variety of spectral and viscosity measurements indicates that protonation of a single group having an apparent pK of 2.1 +/- 0.2 and an intrinsic pK of about 5.3 displaces the methionine ligand without significantly perturbing the native globular conformation. Analysis of methylated ferricytochrome c suggests that protonation of a carboxylate ion, most likely a heme propionate residue, is responsible for displacement of the methionine ligand. Addition of a proton to a second group having an apparent pK of 1.2 +/- 0.1 displaces the histidine ligand and unfolds the protein from a globular conformation into a random coil. It is most likely that the second protonation occurs on the imidazole ring of the histidine ligand itself. Chloride is proposed to perturb these transitions by ligation in the fifth coordination position of the heme ion. Such ligation stabilizes a globular conformation of ferricytochrome c at pH 0.0 and 25 degrees.

The electrochemical behaviour of ferricytochrome c, metmyoglobin and methemoglobin was studied using d.c., a.c. and differential pulse polarography, and controlled potential electrolysis. 1. The three hemoproteins yield d.c. polarographic steps, and peaks in differential pulse polarograms, the height of which is proportional to concentration. The charge transfer is influenced by strong adsorption. 2. The concentration dependence of the a.c. polarograms indicates structural changes in the adsorbed molecules. 3. The reduction products of controlled potential electrolysis of metmyoglobin and methemoglobin have absorption spectra identical with the native control samples. The affinity for oxygen and the cooperativity in hemoglobin are not affected by the reaction at the electrode. 4. The charge transfer proceeds via adsorbed, already reduced, molecules to freely diffusible proteins.

The (Na+ +K+)-activated, Mg2+-dependent ATPase from rabbit kidney outer medulla was prepared in a partially inactivated, soluble form depleted of endogenous phospholipids, using deoxycholate. This preparation was reactivated 10 to 50-fold by sonicated liposomes of phosphatidylserine, but not by non-sonicated phosphatidylserine liposomes or sonicated phosphatidylcholine liposomes. The reconstituted enzyme resembled native membrane preparations of (Na+ +K+)-ATPase in its pH optimum being around 7.0, showing optimal activity at Mg2+:ATP mol ratios of approximately 1 and a Km value for ATP of 0.4 mM. Arrhenius plots of this reactivated activity at a constant pH of 7.0 and an Mg2+: ATP mol ratio of 1:1 showed a discontinuity (sharp change of slope) at 17 degrees C, with activation energy (Ea) values of 13-15 kcal/mol above this temperature and 30-35 kcal below it. A further discontinuity was also found at 8.0 degrees C and the Ea below this was very high (greater than 100 kcal/mol). Increased Mg2+ concentrations at Mg2+:ATP ratios in excess of 1:1 inhibited the (Na+ +K+)-ATPase activity and also abolished the discontinuities in the Arrhenius plots. The addition of cholesterol to phosphatidylserine at a 1:1 mol ratio partially inhibited (Na+ +K+)-ATPase reactivation. Arrhenius plots under these conditions showed a single discontinuity at 20 degrees C and Ea values of 22 and 68 kcal/mol above and below this temperature respectively. The ouabain-insensitive Mg2+-ATPase normally showed a linear Arrhenius plot with an Ea of 8 kcal/mol. The cholesterol-phosphatidylserine mixed liposomes stimulated the Mg2+-ATPase activity, which now also showed a discontinuity at 20 degrees C with, however, an increased value of 14 kcal/mol above this temperature and 6 kcal/mol below. Kinetic studies showed that cholesterol had no significant effect on the Km values for ATP. Since both cholesterol and Mg2+ are known to alter the effects of temperature on the fluidity of phospholipids, the above results are discussed in this context.

The proceedings of a conference organised by students are reported. The present standing of the general practitioner and his need in different societies are equated and the obvious deficiencies are considered. Such themes as maldistribution, service and education are discussed. Resolutions derived from the conference are reported in full.

1. A new procedure is described for selecting nitrogenase-derepressed mutants based on the method of Brenchley et al. (Brenchley, J.E., Prival, M.J. and Magasanik, B. (1973) J. Biol. Chem. 248, 6122-6128) for isolating histidase-constitutive mutants of a non-N2-fixing bacterium. 2. Nitrogenase levels of the new mutants in the presence of NH4+ were as high as 100% of the nitrogenase activity detected in the absence of NH4+. 3. Biochemical characterization of these nitrogen fixation (nif) derepressed mutants reveals that they fall into three classes. Three mutants (strains SK-24, 28 and 29), requiring glutamate for growth, synthesize nitrogenase and glutamine synthetase constitutively (in the presence of NH4+). A second class of mutants (strains SK-27 and 37) requiring glutamine for growth produces derepressed levels of nitrogenase activity and synthesized catalytically inactive glutamine synthetase protein, as determined immunologically. A third class of glutamine-requiring, nitrogenase-derepressed mutants (strain SK-25 and 26) synthesizes neither a catalytically active glutamine synthetase enzyme nor an immunologically cross-reactive glutamine synthetase protein. 4. F-prime complementation analysis reveals that the mutant strains SK-25, 26, 27, 37 map in a segment of the Klebsiella chromosome corresponding to the region coding for glutamine synthetase. Since the mutant strains SK-27 and SK-37 produce inactive glutamine synthetase protein, it is concluded that these mutations map within the glutamine synthetase structural gene.

Seven strains of West nile virus isolated in Nigeria were investigated for their ability to form plaques in monkey kidney cell monolayers. Five strains antigenically related to one another produced plaques of about the same size 3 to 4 days after the addition of the overlay medium. The two other strains closely related to each other produced no plaques. Their inability to produce plaques was regarded as a significant characteristic of the intratypic group to which the two strains belong.

Electron microscopy showed that commerical poly I: C consisted of molecules varying in length from less than 0.05 nm to more than 5 nm and also in morphology . To clarify the relationship between its molecular size and interferon-inducing activity, poly I: C was sonicated or fractionated by sucrose density gradient centrifugation, and the molecular length distribution and interferon-inducing activity of each preparation was determined in vivo and in vitro. The results showed that (1) poly I : C molecules 0.1-0.3 nm long were the most effective for interferon induction; (2) sonication of poly I : C reduced its molecular length and also the interferon-inducing activity, the degree of reduction varying in different fractions; and (3) the interferon-inducing activity of poly I: C of 0.1-0.3 nm obtained by sucrose density gradient centrifugation was higher than that poly I: C of corresponding length prepared by sonication.

Distribution of Lednice (Yaba 1) virus antigen (LVA) was followed by immunofluorescene (IF) in chick embryos inoculated into the yolk sacs. Positive fluorescence of LVA was observed in neurons and neuroblasts of the developing brain, spinal cord and spinal ganglia as well as in skeletal muscles, heart muscle, vascular endothelium and lung mesenchyma. In the yolk sac, foci of specific fluorescence were occasionally seen in endothelium cells of vessels and in islands of extraembryonic haematopoesis. At sites corresponding to the occurrence of LVA, extensive oedema was accompanied by extravazation of erythrocytes and accumulation of white blood cells. The nature of tissues in which the virus replicates was discussed from the point of view of LVA distribution and the morphological lesions observed.

The influence of the sympathetic nervous system on the cerebral circulatory response to graded reductions in mean arterial blood pressure was studied in anesthetized baboons. Cerebral blood flow was measured by the 133Xe clearance method, and arterial blood pressure was decreased by controlled hemorrhage. In normal baboons, the constancy of cerebral blood flow was maintained until mean arterial blood pressure was approximately 65% of the base-line value; thereafter, cerebral blood flow decreased when arterial blood pressure was reduced. Superior cervical sympathectomy of 2-3 weeks duration did not affect the normal response. In contrast, both acute surgical sympathectomy (cervical trunk division) and alpha-receptor blockade (1.5 mg/kg of phenoxybenzamine) enhanced the maintenance of cerebral blood flow in the face of hemorrhagic hypotension in that cerebral blood flow did not decrease until mean arterial blood pressure was approximately 35% of the base-line value. The results indicate that the sympathetic nervous system is not involved in the maintenance of cerebral blood flow in the face of a fall in arterial blood pressure. Indeed, the implication is that the sympathicoadrenal discharge accompanying hemorrhagic hypotension is detrimental to, rather than responsible for, cerebral autoregulation.

1. In one experiment the effect on rumen pH of feeding with restricted amounts of whole or pelleted barley was studied. With whole barley there was little variation in rumen pH associated with feeding time, but with pelleted barley the pH decreased from about 7-0 before feeding to about 5-3, 2--3 h after feeding. 2. The rate of disappearance of dried grass during incubation in the rumens of sheep receiving either whole or pelleted barley was studied in a second experiment. After 24 h incubation only 423 mg/g incubated had disappeared in the rumen of sheep receiving pelleted barley while 625 mg/g incubated had disappeared when it was incubated in the rumen of sheep receiving whole barley. 3. The voluntary intake of dried grass of lambs was studied in a third experiment when they received supplements of either 25 or 50 g whole or pelleted barley/kg live weight 0-75. At the high level, pelleted barley reduced intake of dried grass by 534 g/kg but whole barley reduced it by only 352 g/kg. The digestibility of acid-detergent fibre was reduced more by pelleted barley than by whole barley but there was a tendency for a small increase in digestibility of the barley due to processing. 4. The implications of these findings on supplementation of roughages with cereals are discussed.

Changes in the biological properties of the vaccine strain E of Rickettsia prowazeki occurred upon cultivation of A1 (human amnion) cells infected with this strain. In the course of passages of these cells the antigenic activity and virulence of the rickettsia increased. The changes were observed in 10 out of 22 cell cultures examined: in 6 cultures there was an increase in the antigenic activity and in 4 both in the antigenic activity and in virulence. The time of the occurrence of these changes in the rickettsial populations varied from 12-18 to 53-102 days of passage of the infected cells.

Dairy cows infected naturally with Coxiella burnetii as evidenced either by presence of phase II agglutinating antibodies in the blood or by shedding C. burnetii in the milk, were vaccinated subcutaneously with formalin-killed phase I C. burnetii organisms. Attempts to demonstrate C. burnetii in the milk of vaccinated dairy cows 47 days after vaccination were negative, while continuous shedding of C. burnetii in the milk of control non-vaccinated dairy cows was repeatedly demonstrated in the course of 123 days (period of investigation). No harmful systemic reaction following vaccination was observed.

The approach to the problem of oncogenesis of tumorigenic viruses is compared and analyzed from the position of the Altshtein-Vogt hypothesis and from that of the general theory of oncogenesis advanced by the present author. In contrast to the hypothesis of Altshtein-Vogt dealing mainly with the problem of oncogene origin, the general theory of oncogenesis not only defines concretely the origin of the oncogene and the essence of its product, but also makes it possible to understand why, when and how integration of the oncogene with the genome of the cell leads to the transformation of the cell into a benign cell and when into a malignant tumour cell. An analysis of the essence of the "oncogene position effect" from this standpoint shows that an integration, similar in its mechanism but differing in polarity, of the genome of other viruses with the cell genome should lead to the formation of a corresponding antiviral stable (life-long) immunity or also to the emergence of pseudoautoimmune disease of the type caused by "slow" viruses.

To evaluate responses to medical therapy in ulcerative colitis, rectal biopsies of patients with active untreated disease, individuals with positive and negative sigmoidoscopic findings treated with salicylazosulfapyridine, prednisone and 6-mercaptopurine, alone and in combinations and noncolitis controls were compared histologically. Predominant histological observations were analyzed statistically. There were fewer crypt abscesses but more mucosal edema after all forms of therapy. Quantitative histopathological analysis failed to demonstrate that the response to one drug was significantly different from another.

To evaluate responses to medical therapy in ulcerative colitis, rectal biopsies of patients with active untreated disease, individuals with positive and negative sigmoidoscopic findings treated with salicylazosulfapyridine, prednisone and 6-mercaptopurine, alone and in combinations and noncolitis controls were compared histologically. Predominant histological observations were analyzed statistically. There were fewer crypt abscesses but more mucosal edema after all forms of therapy. Quantitative histopathological analysis failed to demonstrate that the response to one drug was significantly different from another.

The degree of serological relatedness of three isolates of bean yellow mosaic virus (BYMV) was studied. One common antigenic group (m) was demonstrated in all 3 isolates. In addition, another antigenic group (a) was demonstrated in the isolate FvM1. This group was absent from the isolates TpM3 and TpM11, in which the antigenic group n was found. Antisera to the 3 isolates contained the corresponding antibody groups. The antibody group (M) shared by all 3 BYMV isolates was present in the FvM1 antiserum in a level only a little higher than the second antibody group (A). Antisera to TpM3 and TpM11 isolates showed only a low titre of M antibody, while the second antibody group (N) reached titres from 512 to 1024. Cross-absorption tests revealed serological identity of both isolates of the "necrotic type" (TpM3 and TpM11) and allowed to estimate the degree of their serological relatedness to representatives of the "mosaic type" isolates of BYMV (FvM1).

It has been shown that for the reaction catalyzed by "biodegradative" L-threonine dehydratase from E. coli strains K-12 and 980 in 0.5 M phosphate-carbonate buffer, pH 8.4 and pH 9.5, the plots of initial reaction rate (v) versus the initial substrate concentration ([S]0 are characterized by several inflection points, i. e. an intermediate plateau. The plot of v versus the allosteric activator (AMP) concentration have very complicated shapes: there are several inflection points, and also the maximum at L-threonine concentration equal to 3-10(2) and 5-10(-2) M. High AMP concentrations inhibit the enzyme at high substrate concentrations. The reduced glutathion dose not influence the enzyme and does not alter the activating effect of AMP. On the basis of the data obtained it is proposed that the substrate and AMP shift the equilibrium between multiple oligomeric enzyme forms differing in catalytic activity and kinetic manifestations of allosteric interactions between the active and allosteric AMP-binding sites towards polymerization. Thus, the functioning the enzyme under study is discussed in the frames of the model of dissociating regulatory enzymes with multiple intermediate oligomeric forms.

In connection with the modelling of biomembranes regularities of the formation and development of interphase adsorption layers of lysozyme at liquid borders under different conditions and depending on the nature of carbohydrate phase were investigated by the determination of mechanical characteristics of such layers. The investigations carried out showed that the most solid layers appeared under the conditions which assured the formation of the maximum number of intermolecular bonds (which in a common case is performed with maximum disorderlinesss of the macromolecules which get at the interphase).

In connection with the modelling of biomembranes regularities of the formation and development of interphase adsorption layers of lysozyme at liquid borders under different conditions and depending on the nature of carbohydrate phase were investigated by the determination of mechanical characteristics of such layers. The investigations carried out showed that the most solid layers appeared under the conditions which assured the formation of the maximum number of intermolecular bonds (which in a common case is performed with maximum disorderlinesss of the macromolecules which get at the interphase).

It is proposed that the direct analgesic effect of morphine becomes attenuated over the course of successive administrations of the narcotic by a conditioned, compensatory, hyperalgesic response elicited by the administration procedure, the net result being analgesic tolerance. Using the "hot plate" analgesia assessment situation with rats, this conditioning view of tolerance is supported by several findings: (a) It is necessary to have reliable environmental cues predicting the systemic effects of morphine if tolerance is to be observed, (b) a hyperalgesic conditioned response may be observed in morphine-tolerant subjects when drug administration cues are followed by a placebo, and (c) merely by repeatedly presenting environmental cues previously associated with morphine (but now presented with a placebo), morphine tolerance can be extinguished.

Seven distinct glycosidases (EC 3.2) have been characterized in guinea-pig epidermis. Their properties indicate them to be of lysosomal origin. The 'profile' of the epidermal glycosidases is significantly different from that reported for whole skin, the activities of beta-galactosidase and beta-acetylglucosaminidase being very high and those of the remaining enzymes relatively low in epidermis.

In a case of poisoning involving 70 cattle analysis of specimens obtained during post mortem examination showed that the toxic substances were arsenic and toxaphene. This was consistent with both the clinical and post mortem findings. Arsenic was detected in water from an abandoned cattle dip in the farm. Soil samples collected in the vicinity of the dip contained both arsenic and toxaphene.

Strictly anaerobic and facultatively anaerobic strains of "corroding bacilli" failed to produce any pathological symptoms when injected into white mice and no viable organisms could be recovered after 7 days. However, when these same strains were coupled with certain other living bacteria or certain sterile bacterial extracts, lesions developed from which corroding bacilli could be isolated even after 21 days.

A purification procedure is reported for obtaining bovine liver dihydrofolate reductase in high yield and amounts of 100-200 mg. A key step in the procedure is the use of an affinity gel prepared by coupling pteroyl-L-lysine to Sepharose. The purified reductase has a specific activity of about 100 units/mg and is homogeneous as judged by analytical ultracentrifugation, polyacrylamide gel electrophoresis, and titration with methotrexate. The products of the first step of Edman degradation indicated a minimum purity of 79%. The reductase has a molecular weight of about 21500 on the basis of amino acid composition and 22100 +/- 300 from equilibrium sedimentation. It is not inhibited by antiserum to the Streptococcus faecium reductase (isoenzyme 2). Unlike the reductase of many other vertebrate tissues, the bovine enzyme is inhibited by mercurials rather than activated and it has a single pH optimum at both low and high ionic strength. However, the position of the pH optimum is shifted and the activity increased by increasing ionic strength. Automatic Edman degradation has been used to determine 34 of the amino-terminal 37 amino acid residues. Considerable homology exists between this region and the corresponding regions of the reductase from S. faecium and from Escherichia coli. This strengthens the idea that this region contributes to the structure of the binding site for dihydrofolate.

The near-ultraviolet circular dichroism (CD) of three homogeneous anti-type III pneumococcal antibodies in the absence and the presence of the specific hexasaccharide ligand was studied. In addition recombinations and hybridizations of H and L chains derived from two of these antibodies were carried out and the CD spectra of bound and free reconstituted IgG molecules were measured. The results indicate that the CD spectra of the native antibodies in the 260-310-nm range are very similar in shape and sign and exhibit a positive band at 285 nm. The homologous reconstituted antibody molecules exhibited CD spectra very similar in shape and sign to those of the native antibody molecules although recombinant molecules are no longer stabilized by interchain disulfide bonds. Upon addition of the hexasaccharide ligand, a significant decrease in amplitude of the CD spectra (18-21%) occurred in all three native antibodies and their Fab fragments as well as in the homologous recombinant molecules. No CD spectral changes could be detected upon interaction of the hapten ligand with the heterologous recombinants. All homogeneous antibodies studied exhibited fluorescence quenching upon oligosaccharide binding and a blue shift of the emission maximum. This property allowed the determination of the binding constant of one selected antibody to be made. Taken together, CD and fluorescence spectroscopic data suggest that oligosaccharide ligands induced detectable conformational changes in the Fab fragment of the antibody.

Ionization effects on the binding of the potential transition state analogues 2-phosphoglycolate and 2-phosphoglycolohydroxamate appear to be attributable to the changing state of ionization of the ligands themselves, therefore it is unnecessary to postulate the additional involvement of an ionizing residue at the active site of triosephosphate isomerase to explain the influence of changing pH on Ki in the neutral range. The binding of the competitive inhibitor inorganic sulfate is insensitive to changing pH in the neutral range. 3-Chloroacetol sulfate, synthesized as an active-site-specific reagent for triosephosphate isomerase, is used to provide an indication of the pKa of the essential carboxyl group of this enzyme. Previously described active-site-specific reagents for the isomerase were phosphate esters, and their changing state of ionization (accompanied by possible changes in their affinity for the active site) may have complicated earlier attempts to determine the pKa of the essential carboxyl group from the pH dependence of the rate of inactivation. Being a strong monoprotic acid, chloroacetol sulfate is better suited to the determination of the pKa of the carboxyl group. Chloroacetol sulfate inactivates triosephosphate isomerase by the selective esterification of the same carboxyl group as that which is esterified by the phosphate esters described earlier. From the pH dependence of the rate of inactivation of yeast triosephosphate isomerase, the apparent pKa of the active-site carboxyl group is estimated as 3.9 +/- 0.1.

Kinetic analyses of monoanion inhibition and 15Cl nuclear magnetic resonance at 5.88 MHz were employed to study monoanion interactions with the zinc metalloenzyme, renal dipeptidase. The enzyme-catalyzed hydrolysis of glycyldehydrophenylalanine exhibited competitive inhibition when the reaction rate was determined in the presence of the monovalent anions fluoride, chloride, bromide, iodide, azide, nitrate, or thiocyanate or upon the addition of the divalent anion, sulfate. Competitive inhibition was produced by these anions. One anion was bound per enzyme molecule, and except in the case of fluoride all of the anions appeared to bind at the same site. Cyanide ion produced a much more effective inhibition of renal dipeptidase than the other monoanions, and it was shown that two cyanide ions were bound per enzyme molecule. An investigation of the effect of pH upon monoanion inhibition suggested that the anion inhibitors bind to the group with a pK of approximately 7.8. Complete dissociation of this group (approximately pH 8.4) eliminates the inhibitory effect of anions. The 35Cl line broadening produced by renal dipeptidase in 0.5 M NaCl solutions was 100 times more effective than that produced by equivalent concentrations of aquozinc(II). The line broadening was dependent upon the concentration of the metalloenzyme and independent of the frequency of the exciting radiation. When zinc ion was removed from the metalloenzyme by dialysis or when chloride was titrated from the metalloenzyme by cyanide, line broadening was decreased. Treatment of renal dipeptidase with saturating concentrations of the competitive inhibitor, guanosine triphosphate, in the presence of 0.5 M NaCl also produced a significant decrease in the 35Cl line width. The 35Cl line broadening produced by renal dipeptidase was shown to decrease with increasing pH through the range pH 5.8-10.8. This line-width variation with pH appeared to result from the titration of a site on the metalloprotein with an approximate pK of 7.4. Temperature studies of 35Cl line broadening by the metalloenzyme in the presence of chloride and cyanide inhibitors suggest that the fast exchange process pertains and that the dominant relaxation mechanism is quadrupolar in nature.

The major group of aminopeptidases (EC 3.4.11.-) of intermediate electrophoretic mobility, from Tineola bisselliella larvae, hav been fractionated into six bands by preparative polyacrylamide gel electrophoresis and the properties of these fractions investigated. They resemble each other in their pH optima of 8.2, their molecular weight of 240 000, their responses to various active site inhibitors and metal cations, and their specificities towards seventeen L-amino-acyl-beta-naphthylamide substrates. The derivatives of methionine, leucine, alanine, lysine, arginine and glutamic acid were those most rapidly hydrolysed. They appear to be true aminopeptidases hydrolysing amino acid amides, dipeptides and oligopeptides from the N-terminal end.

(11 Cell extracts and extracellular culture fluids of species of the yeast genus Schizosaccharomyces exhibited exo-beta-(1 leads to 3)- and exo-beta-(1 leads to 6)-glucanase (EC 3.2.1.-) activities. (2) Using a combination of Sephadex G-100 and DEAE-cellulose chromatography, the exo-beta-(1 leads to 3)-glucanases from the cell extracts and culture fluid of Schizosaccharomyces japonicus var. versatilis were purified extensively. The enzymes from either location exhibited similar purification and other properties. (3) The purified enzymes hydrolysed the beta-(1 leads to 6)-glucosidic linkage in addition to the beta-(1 leads to 3) linkage. Heat denaturation, inhibition and electrophoretic studies indicated that both hydrolytic activities were properties of a single protein. Laminarin and pustulan hydrolysis followed Michaelis-Menten kinetics. The Km and V for laminarin hydrolysis were 6.25 mg/ml and 350 mumol of glucose released/min/mg protein, and for pustulan they were 166 mg/ml and 52 mumol of glucose released/min/mg protein. (4) The exo-beta-glucanase was assigned a molecular weight of 43 000. (5) the purified enzyme failed to hydrolyse isolated cell walls from either baker's yeast or Schizosaccharomyces pombe or to induce protoplast formation from intact cells of S. japonicus var. versatilis or Saccharomyces cerevisiae.

A preparation of ATPase from the membranes of Micrococcus lysodeikticus, solubilized and more than 95% pure, showed two main bands in analytical polyacrylamide gel electrophoresis. They did not correspond to isoenzymes because one band could be converted into the other by exposure to a mildly alkaline pH value. The conversion was paralleled by changes in molecular weight, circular dichroism and catalytic properties. Denaturation by pH at 25 degrees C was followed by means of circular dichroism, ultracentrifugation and polyacrylamide gel electrophoresis. A large conformational transition took place in the acid range with midpoints at about pH = 3.6 (I = 10(-4) M), 4.3 (I = 0.03 M) and 5.3 (I = 0.1 M). The transition was irreversible. Strong aggregation of the protein occurred in this range of pH. The final product was largely random coil, but even at pH 1.5 dissociation into individual subunits was not complete. However, partial dissociation took place at pH 5 (I = 0.028 M). At this pH value the enzyme was inactive, but 20-30% of the activity could be recovered when the pH was returned to 7.5. In the alkaline region the midpoint of the transition occurred near pH = 11 (I = 0.028 M). The pK of most of the tyrosine residues of the protein was about 10.9. The unfolding was irreversible and the protein was soon converted into peptide species with molecular weights lower than those determined for the subunits by gel electrophoresis in the presence of sodium dodecyl sulphate. Conventional proteolysis did not account for the transformation.

The reduction of metmyoglobin by the iron(II) complex of trans-1,2-diaminocyclohexane-N,N,N'N'-tetraacetate (FeCDTA2-) has been investigated. The equilibrium constant, measured spectrophotometrically, is 0.21 with a resulting reduction potential of 0.050 V for Mb0. The rate constant for the reduction is 28 M-1 sec-1 with a deltaH ++ of 13 kcal M-1 and deltaS ++ of -11 eu. Both CN- and OH- inhibit the reduction because of the relatively low reactivity of cyanometmyoglobin (Mb+CN-) and ionized metmyglobin (Mb+OH-). The rate constant for the reduction of Mb+CN- by FeCDTA2- is 4.0 X 10(-2) M-1 sec-1 and that for reduction of Mb+OH- is 4.8 M-1 sec-1. The nitric oxide complex of metmyoglobin is reduced with a rate constant of 10 M-1 sec-1. The kinetics of oxidation of oxymyoglobin by FeCDTA- were studied. The data are consistent with a mechanism where oxidation takes place entirely through the deoxy form. A rate constant of 1.45 X 10(2) M-1 sec-1 was calculated for the oxidation of deoxymyoglobin by FeCDTA-, in equilibrium constant and rate constant for reduction. The above data are discussed in terms of a simple outer-sphere reduction reaction.

The contractile proteins from arterial smooth muscle are highly soluble, and can be extracted at I = 0.05. However, they can be precipitated by a prolonged dialysis at pH 6 to give an actomyosin with a high, although variable, actin:myosin ratio. The sedimentation behavior of this actomyosin at high ionic strength was examined as a function of pH, protein concentration and composition by preparative ultracentrifugation. Comparisons with synthetic skeletal muscle actomyosins of similar composition demonstrated significant differences in the behaviors of these two systems. It was found that much smooth muscle actomyosin is not dissociated by normally relaxing conditions, and that it sediments at a slower rate than F-actin. The solubility of the supernatant protein (a myosin-enriched actomyosin) in 0.2 M K Cl (pH 7) depended on the pH during centrifugation. A lower solubility was associated only with a higher actin concentration in the supernatant, suggesting a dependence on actin repolymerization. Pure myosin was selectively precipitated from the supernatant by polyethylene glycol-6000, but only when the protein was soluble at low ionic strength. The solubility of purified myosin was similar to that of myosin from striated muscles. A relationship between the presence of depolymerized actin and the high solubility of smooth muscle contractile proteins is suggested.

Hb-Manitoba was discovered in 1970 [1] in a Canadian family of British origin. Recently we observed the same variant in a second family, and found that the oxy-derivative of Hb-Manitoba is slightly unstable at 65 degrees C, dissociates less readily at alkaline pH than does Hb-A, and forms asymmetric hybrids with other hemoglobins which are readily detectable by electrophoresis.

Photosystem II reaction center components have been studied in small system II particles prepared with digitonin. Upon illumination the reduction of the primary acceptor was indicated by absorbance changes due to the reduction of a plastoquinone to the semiquinone anion and by a small blue shifts of absorption bands near 545 nm (C550) and 685 nm. The semiquinone to chlorophyll ratio was between 1/20 and 1/70 in various preparations. The terminal electron donor in this reaction did not cause large absorbance changes but its oxidized form was revealed by a hitherto unknown electron spin resonance (ESR) signal, which had some properties of the well-known signal II but a linewidth and g-value much nearer to those of signal I. Upon darkening absorbance and ESR changes decayed together in a cyclic or back reaction which was stimulated by 3-(3,4 dichlorophenyl)-1,1-dimethylurea. The donor could be oxidized by ferricyanide in the dark. Illumination in the presence of ferricyanide induced absorbance and ESR changes, rapidly reversed upon darkening, which may be ascribed to the oxidation of a chlorophyll a dimer, possibly the primary electron donor of photosystem II. In addition an ESR signal with 15 to 20 gauss linewidth and a slower dark decay was observed, which may have been caused by a secondary donor.

Photosystem II reaction center components have been studied in small system II particles prepared with digitonin. Upon illumination the reduction of the primary acceptor was indicated by absorbance changes due to the reduction of a plastoquinone to the semiquinone anion and by a small blue shifts of absorption bands near 545 nm (C550) and 685 nm. The semiquinone to chlorophyll ratio was between 1/20 and 1/70 in various preparations. The terminal electron donor in this reaction did not cause large absorbance changes but its oxidized form was revealed by a hitherto unknown electron spin resonance (ESR) signal, which had some properties of the well-known signal II but a linewidth and g-value much nearer to those of signal I. Upon darkening absorbance and ESR changes decayed together in a cyclic or back reaction which was stimulated by 3-(3,4 dichlorophenyl)-1,1-dimethylurea. The donor could be oxidized by ferricyanide in the dark. Illumination in the presence of ferricyanide induced absorbance and ESR changes, rapidly reversed upon darkening, which may be ascribed to the oxidation of a chlorophyll a dimer, possibly the primary electron donor of photosystem II. In addition an ESR signal with 15 to 20 gauss linewidth and a slower dark decay was observed, which may have been caused by a secondary donor.

This study compared the contractile performance of a canine right atrial trabecula with that of a macroscopically indistinguishable trabecula isolated from the right ventricular apex. The heart was removed from nine mongrel puppies weighing 6-8 kg and placed in Krebs-Ringer's bicarbonate solution. The bathing solution contained only 1.25 mmoles of Ca2+ and was bubbled with a 95% O2-5% CO2 gas mixture. Each atrial trabecula was specially selected from the right atrial appendage. Histologically, these trabeculae showed a remarkable longitudinal orientation of the fibers. At Lmax (the length of the muscle at which developed tension was maximum) under identical conditions of temperature, rate of stimulation, ionic milieu, pH, and O2 and CO2 supply, right atrial trabeculae achieved the same developed and total tensions but in a much shorter time than did ventricular trabeculae. In both muscle groups the maximum developed tension averaged about 2.5 g/mm2. Since Lo (expressed as a fraction of Lmax) was less in atrial muscle than it was in ventribular muscle, we concluded that atrial muscle can be stretched considerably more than can ventricular muscle before optimum length is reached. At any given initial muscle length, the maximum of tension rise for atrial trabeculae amounted to at least twice that for ventricular trabeculae. At any given load up to 1.5 g/mm2, the maximum velocity of shortening of an atrial trabecula was about three to four times that of a ventricular trabecula. These results collectively indicate that the contractile performance of the right atrial muscle is in many respects superior to that of the right ventricle, at least under the conditions of these experiments.

The purification and properties of a novel type of murein transglycosylase from Escherichia coli are described. The purified enzyme appears as a single band on sodium dodecyl sulfate-polyacrylamide gels and has an apparent molecular weight of approximately 65,000 as estimated by gel filtration and gel electrophoresis. It degrades pure murein sacculi from E. coli almost completely into low-molecular-weight products. The two prominent muropeptide fragments in the digest are the disaccharide-tripeptide N-acetylglucosamine-N-acetylmuramic acid-L-alanine-D-iso-glutamic acid-meso-diaminopimelic acid and the corresponding disaccharide-tetrapeptide N-acetylglucosamine-N-acetylmuramic acid-L-alanine-D-iso-glutamic acid-meso-diaminopimelic acid-D-alanine. The unique feature of these compounds is that the disaccharide has no reducing end group and that the muramic acid residue possesses an internal 1 leads to 6 anhydro linkage. The new lytic enzyme is designated as a murein: murein transglycosylase. Its possible role in the rearrangement of murein during cell growth and division is discussed.

1 Pyometra is a disorder of the uterus usually associated with bacterial infection plus obstruction. 2 Large quantities of fluid often collect in the uterus during this condition. 3 Pyometrial fluid obtained from three species was found to contain prostaglandin F2alpha, usually in large quantities. 4 Prostaglandin E2 was present in smaller quantities in five of the six samples. 5 These findings are discussed in relation to the known occurrence of prostaglandins in inflammatory fluid, and to the problem of infertility.

Stimulation with phytohemagglutinin of the leukocytes from six of the seven known individuals with UDP-galactose 4-epimerase (= UDP-glucose 4-epimerase; EC 5.1.3.2) deficiency consistently resulted in the appearance of epimerase activity in the cultured cells. A long-term lymphoblast culture derived from one proband also contained an active epimerase enzyme. A comparison of the properties of this enzyme with those of epimerase produced by control lymphoblast lines revealed comparable Km values for UDP-galactose and NAD and identical behavior on polyacrylamide electrophoresis. However, a difference in the NAD requirement for heat stability at 40 degree provided some evidence for a structural defect in this enzyme. Possible explanations for the appearance of UDP-galactose 4-epimerase activity in stimulated lymphocytes include an increased rate of synthesis of a mutant enzyme and a derepression of an epimerase locus during lymphocyte transformation.

This project involved designing, developing and evaluating a simulation module, utilizing the latent image technique. The general topic chosen for this simulation was the laboratory characterization of anemias. Target learner populations included medical technology students, physician assistant students, and pathology residents. Members of all three groups participated in the evaluation of the module and responded to its use in varied settings.

This project involved designing, developing and evaluating a simulation module, utilizing the latent image technique. The general topic chosen for this simulation was the laboratory characterization of anemias. Target learner populations included medical technology students, physician assistant students, and pathology residents. Members of all three groups participated in the evaluation of the module and responded to its use in varied settings.

d-Norpseudoephedrine, a central stimulant present in Catha edulis, is excreted unchanged in human urine. The alkaloid was detected in urine 30-50 min after ingestion of synthetic d-norpseudoephedrine, and trace amounts of the drug could still be detected 24 hr later. Approximately 40% of ingested d-norpseudoephedrine was recovered in urine in the first 6 hr.

The inhibitory effect of molybdenum ions on growth of yeasts at pH 5.5 was found to be decreased by aldoses in the following order: D-talose greater than L-mannose greater than L-ribose greater than D-lyxose greater than L-galactose greater than L-arabinose greater than L-glucose greater than L-xylose. Increased concentrations of molybdenum brought about morphological changes of yeast cells. Cells grown under these conditions were smaller, had thicker walls and formed clusters.

FDP aldolase was found to be present in the cell-free extracts of Rhizobium leguminosarum, Rhizobium phaseoli, Rhizobium trifolii, Rhizobium meliloti, Rhizobium lupini, Rhizobium japonicum and Rhizobium species from Arachis hypogaea and Sesbania cannabina. The enzyme in 3 representative species has optimal activity at pH 8.4 in 0.2M veronal buffer. The enzyme activity was completely lost by treatment at 60 degrees C for 15 min. The Km values were in the range from 2.38 to 4.55 X 10(-6)M FDP. Metal chelating agents inhibited enzyme activity, but monovalent or bivalent metal ions failed to stimulate the activity. Bivalent metal ions in general were rather inhibitory.

Twenty-five Penicillium species isolated from Egyptian soil were examined for their ability to produce gluconic acid in surface culture. Of the eight species capable of producing gluconic acid, Penicillium puberulum gave the maximum yield (91% gluconic acid from glucose after 7 days of fermentation with 3% CaCO3). Peptone was the best nitrogen source for acid fermentation and glucose was superior to sucrose. Addition of low concentrations of KH2PO4 and MgSO4 - 7 H2O stimulated acid production. An initial pH of 6.1 was most favourable for acid accumulation and addition of CaCO3 was necessary for maximum acid production.

Biflavanoid patterns of leaves of 82 species of the order Cycadales comprising 3 families and 10
genera have been determined. The biflavanoidswere Identified byTLC, UV, NMR and MS studies. Pattern differences between species, when detected, involve the position or degree of methylation of the base compounds. On the other hand, differences in the biflavanoid patterns at the generic and family levels were sufficient to support taxonomic relationships. Thus, the absence of hinokiflavone and its derivatives clearly distinguish the Zamiaceae from the Cycadaceae and Stangeriaceae. The complete absence of biflavanoids in the latter family suggests an advanced evolutionary condition, but morphologically, this family has the most fern-like characters, and therefore has been considered by previous workers to be the most primitive of the cycads.

Thin layer chromatography, coupled with UV-visible spectral data using various
diagnostic shift reagents, was used to differentiate between nineteen bioflavanoids which were
either unsubstituted, partially methylated, or fully methylated. These included biflavanoids of
the amentoflavone type (1-9), 2,3,Klihydroamentoflavone (12), hinokiflavone type (10-11),
2,3,-dihydrohinokiflavone (13), cupressuflavone type (14-16), agathisflavone type (17-18), and
morelloflavone (19).

A fall in Rhizobium abundance occurred in nonsterile soil inoculated with large numbers of the root-nodule bacteria but many of the rhizobia still survirved. No such decline was evident in sterile soil. Protozoa feeding on these bacteria were isolated from soil and other environments. As the abundance of Rhizobium meliloti and a cowpea Rhizobium strain in soil decreased, the protozoan density increased. The inability of the predators to eliminate their prey,from soil was not the result of the presence of organisms feeding on the protozoa because many rhizobia survived in sterile soil inoculated with the prey and cultures of individual protozoa nor was it the result of the rapid multiplication of the bacteria to replace those consumed because survivors were still numerous in essentially organic matter free soil in which the hactena did not grow appreciably. The lack of elimination also was not associated with a protective effect of soil particles because survivors were still abundant in solutions inocuiated with protozoa and bacteria.It is suggested that the size of the prey population diminishes until a density is attained at which the energy used by the predator in hunting for the survivors equals that obtained from the feeding.

Rhizobium strains of the cowpea group did not lose viability readily when added to soil, but Bdellovibrio acting on these rhizobia were found in 32 of 90 soils examined. Bdellovibrio did not initiate replication in liquid media at low host densities, but it did multiply once the Rhizohium numbers increased through growth to about 108 ml−1. From about 104 to 6 × 105 ml−1Rhizohium cells survived attack by the parasites in liquid media. In nutrient-free buffer, no significant increase in vibrio abundance was evident if the rhizobial frequency was low. whereas Rhizobium populations containing 6 × 108 cells ml−1 were lysed rapidly. Bdellovibrio did not multiply when introduced into sterile soil with small numbers of the host, but it replicated when the rhizobia were abundant because of the latter's use of soil organic matter for growth or because of the deliberate addition of 108Rhizohium g−1. Nevertheless, the host persisted in such vibrio-rich soil samples. The abundance of indigenous bdellovibrios increased appreciably in nonsterile soil if the rhizobia were introduced in large but not small numbers. It is suggested that a major reason for the lack of elimination of the host population in soil by its parasites is the need for a critical host cell frequency, large Rhizobium numbers being required for Btiellovibrio to initiate replication and low numbers of surviving hosts no longer being able to support the parasite.

In experiments, adult marabou storks were fed with hydatid fluid of viable Echinococcus cysts obtained from sheep and goats. On microscopic examination of the birds' faeces no scolices were found, the only remaining undigested parts of the parasites fed being the chitinous hooks of the rostellum. The feeding trials have shown that the marabou does not play a role in the spread of echinococcosis from the abattoir.