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101 | Ehlers-Danlos type V (X-linked form): a lysyl oxidase deficiency. | |
102 | Urinary alpha-L-fucosidase. | |
103 | [Combined effects of hypoxia and hypercapnia on the functional state of the respiratory center]. | Experiments were conducted on cats under nembutal anesthesia; a study was made of pulse activity of bulbar respiratory neurons, electrical activity of the diaphragm and of the intercostal muscles; pO2, pCO2, pH, arterial blood oxygen saturation were determined in combined action of hypoxia and hypercapnia. When hypoxic gaseous mixture was given for respiration the developing hypocapnia disturbed the discharge rhythmic activity of the respiratory neurons, the respiration acquiring a pathological character of the Cheyne--Stokes type. After addition to the hypoxic gaseous mixture of 2% CO2 the gaseous composition of the arterial blood approached the initial values; this addition prevented the development of hypercapnia and disturbances of rhythmic discharge activity of the respiratory neurons. Addition of 5% CO2 to the hypoxic gaseous mixture produced a negative effect: at first it intensified and then depressed the pulse activity of the respiratory neurons, caused metabolic and respiratory acidosis, and promoted asphyxia. |
104 | [Level of nicotinamide coenzymes in the liver and myocardium of rats poisoned with dichlorethane]. | Experiments were conducted on male rats. A study was made of the content of nicotinamide coenzymes in the liver and myocardium 24 hours after the administration of 0.5 ml of dichloroethane into the stomach. In parallel with disturbance of the morphological structure of the liver and of the myocardium, increase in the activity of alanine and aspargic aminotranspherases in the blood serum, dichloroethane reduced the content of nicotinamide coenzymes and deranged the ratio of their oxidized and reduced forms in these organs. |
105 | [Effect of carbidine on conditioned defense reflexes]. | Chronic experiments were conducted on rats and rabbits; a study was made of the effect of carbidine on the conditioned defence reflexes in stimulation of the mesencephalic part of the reticular formation. Carbidine prevented the depression of the conditioned defence reflexes caused by stimulation of the mesencephalic portion of the reticular formation. This pointed to its depressive influence on the mentioned structures, and was confirmed by experiments on rabbits in recording changes in biocurrents under conditions of stimulation of the mesencephalic reticular formation. |
106 | [Level of nicotinamide coenzymes in the myocardium of rats during the effects of methylxanthines (theophylline, theobromine, caffeine) and catecholamines]. | It was shown in acute experiments on rats that one hour after an intraperitoneal injection of theophylline (50 mg/kg) there was a decrease in the NAD + NADP content by 19.4%, a tendency to a fall of NAD.H2 + NADP.H2 was expressed, and the total nicotinamide coferment level was reduced. A tendency to decrease NAD + NADP and the total pyridine nucleotide level was seen after caffeine administration. The action of catecholamines and methylxanthines was compared. Theobromine produced no significant effect on the indices under study. It was shown that isadrine decreased the NAD + NADP level; adrenaline (25 mkg/kg) increased the content of both the oxidized (by 24%) and of the reduced (by 48%) forms of pyridine nucleotides. An increase of adrenaline dose to 1000 mkg/kg was accompanied by reduction of the oxidized forms (by 22.2%) and of the total nicotinamide coferment level (by 18%). |
107 | Potable water quality in rural Georgetown County. | Drinking water supplies of 161 rural communities, in Georgetown County, South Carolina, were randomly selected for sample collection. The analysis showed that most of the waters were slightly acidic. Low, but acceptable concentrations of chloride, copper, fluoride, sodium, cadmium, nitrate and phosphate were found. A few water samples showed higher then recommended levels of arsenic, mercury, zinc and lead. Although only 2% of the samples exceeded the mandatory limit of 0.05 ppm for arsenic, 72% exceeded the recommended level of 0.01 ppm. The mandatory limit for manganese was exceeded in 37% of the waters while 88% exceeded the limit for iron. The high iron content was generally responsible for the high turbidity found in 45% of the samples. The well depth and the consumer income had some bearing on water quality. Statistical evidence suggested that septic tank seepage was partially responsible for nitrate, phosphate, iron and arsenic contamination of shallow water supplies. Lead concentrations appear to vary according to the plumbing used and the pH of the waters. |
108 | Symposium on malaria research. | |
109 | 6th International Symposium on Maritime Medicine 1974. | |
110 | Polypsychopharmacy. | |
112 | PH changes on the surface of burns. | |
113 | Proceedings: The effects of glucagon on the hepatic arterial vasculature of the dog: an inhibition of the effects of vasoconstrictor agents. | |
111 | [Oxygen affinity of haemoglobin (author's transl)]. | |
114 | Proceedings: Central hypertensive action of histamine in rats. | |
115 | Proceedings: Response of identified ventromedial hypothalamic nucleus neurons to putative neurotransmitters applied by microiontophoresis. | |
116 | Proceedings: The mechanism of "adrenaline reversal" in the anaesthetized cat and rabbit. | |
117 | Proceedings: Is ATP an inhibitory neurotransmitter in the rat stomach. | |
118 | Proceedings: Comparison of the effects of selective alpha and beta-receptor agonists on intracellular cyclic AMP levels and glycogen phosphorylase activity in guinea-pig liver. | |
119 | Proceedings: The role of dopamine in rotational behaviour produced by unilateral lesions of the locus coeruleus. | |
120 | Proceedings: Do anti-psychotic drugs act by dopamine receptor blockade in the nucleus accumbens. | |
121 | Proceedings: Evaluation of narcotic and narcotic antagonist analgesic drugs in the dog dental pulp stimulation test. | |
122 | Meso-appendicular testis. | |
123 | The importance of an innervated and intact antrum and pylorus in preventing postoperative duodenogastric reflux and gastritis. | This study has investigated the relationship between duodenogastric reflux, gastritis and certain symptoms 6-12 months after three operations for uncomplicated duodenal ulcer. The operations studied were proximal gastric vagotomy (PGV, 20 cases), truncal vagotomy and pyloroplasty (TV+P, 22 cases) and truncal vagotomy and antrectomy (TV+A, 21 cases). Duodenogastric reflux was assessed both by a radiological technique and by measuring the concentration of bilirubin in the gastric aspirate before and after operation. Incidence and severity of postoperative gastritis were determined by endoscopic biopsy. Symptoms were assessed by symptomatic score and Visick grading. There was a significant correlation between duodenal reflux and histological evidence of both severe superficial gastritis and glandular atrophy (P less than 0-01). There was also a close association between the degree of reflux and the presence of severe heartburn, epigastric pain and bile vomiting after operation. The amount of reflux did not differ before operation. There was significantly less reflux following PGV than after either TV+P (P less than 0-025) or TV+A (P less than 0-001). The results indicate that an operation which preserves an innervated and intact antrum and pylorus will protect against postoperative duodenogastric reflux, gastritis and symptoms. |
124 | Haemoglobin Rahere (beta Lys-Thr): A new high affinity haemoglobin associated with decreased 2, 3-diphosphoglycerate binding and relative polycythaemia. | 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. |
125 | Endoscopic papillotomy and removal of gall stones. | Endoscopic papillotomy was attempted in 59 patients with extrahepatic obstruction of the biliary duct system and was actually performed in 50 patients. A special high-frequency diathermy knife was introduced via a duodenoscope into the terminal common bile duct and the roof of the papilla was incised. In 33 out of 39 patients with choledocholithiasis the stones passed into the duodenum spontaneously or were removed endoscopically. Papillary stenosis without ductal stones was successfully treated with this method in eight out of 11 patients. One perforation of the duodenocholedochal junction occurred and was repaired surgically. Endoscopic papillotomy and stone extraction is a relatively safe and effective method of treating extrahepatic jaundice. |
126 | Phobias complicating treatment of uterine carcinoma. | |
127 | Editorial: Childhood poisoning: prevention and first-aid management. | |
128 | Inhibitory postsynaptic actions of taurine, GABA and other amino acids on motoneurons of the isolated frog spinal cord. | The actions of glycine, GABA, alpha-alanine, beta-alanine and taurine were studied by intracellular recordings from lumbar motoneurons of the isolated spinal cord of the frog. All amino acids tested produced a reduction in the amplitude of postsynaptic potentials, a blockade of the antidromic action potential and an increase of membrane conductance. Furthermore, membrane polarizations occurred, which were always in the same direction as the IPSP. All these effects indicate a postsynaptic inhibitory action of these amino acids. When the relative strength of different amino acids was compared, taurine had the strongest inhibitory potency, followed by beta-alanine, alpha-alanine, GABA and glycine. Topically applied strychnine and picrotoxin induced different changes of post-synaptic potentials, indicating that distinct inhibitory systems might be influenced by these two convulsants. Interactions with amino acids showed that picrotoxin seletively diminished the postsymaptic actions of GABA, while strychnine reduced the effects of taurine, glycine, alpha- and beta-alanine. But differences in the susceptibility of these amino acid actions to strychnine could be detected: the action of taurine was more sensitively blocked by strychnine compared with glycine, alpha- and beta-alanine. With regard to these results the importance of taurine and GABA as transmitters of postsynaptic inhibition on motoneurons in the spinal cord of the frog is discussed. |
129 | The involvement of lysophosphoglycerides in neurotransmitter release; the composition and turnover of phospholipids of synaptic vesicles of guinea-pig cerebral cortex and Torpedo electric organ and the effect of stimulation. | (1) Crude synaptosomal fractions (P2) derived from guinea-pig cerebral cortex were incubated in the presence of 50 mM KCl in a Krebs-glucose medium. Torpedo marmorata electric organs were stimulated electrically in vivo at 5 pulses/sec for 30 min by electrodes placed on the electric lobe. Synaptic vesicles were isolated from each source and the phospholipid compositions analysed and compared with vesicles from unstimulated controls. (2) Lysophosphatidylcholine was the only lysophosphoglyceride demonstrable in the synaptic vesicles from either source and its low levels did not increase as a result of chemical or electircal stimulation. In each case there was a close similarity of the phospholipid distributions in the vesicles taken from control and stimulated samples. (3) Control experiments indicated extensive decreases in the acetylcholine content of the vesicles from the stimulated electric organ and smaller decreases in the acetylcholine content of the synaptic vesicles from stimulated crude synaptosomal fractions. These fractions were found to respire linearly in the presence of 10 mM glucose and the vesicle fractions were shown to have low levels of contaiminating membranes as judged by marker enzyme analyses. (4) Crude synaptosomal fractions from guinea-pig cerebral cortex were incubated in a Krebs-glucose medium with labelled fatty acids and [3H]glucose in the presence or absence of 50 mM KCl. Subsynaptosomal fractionation was carried out and specific radioactivities of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were determined in fractions D (synaptic vesicles), E (microsomes) and H (disrupted synaptosomes). The release of neurotransmitter did not significantly enhance the labelling of phospholipids in any of the fractions studied as compared with phospholipids from unstimulated fractions. This was found after two incubation times and using [14C]oleate, [14C]arachidonate, [3H]palmitate and [3H]glucose. |
130 | Uptake of radiolabeled glucose analogues by organotypic pia arachnoid cultures. | |
131 | Processing of tRNA precursors in higher organisms. | |
133 | The prevention of autolysis of stored cornea using steroid as a lysosome membrane stabilizer. | Many eyes donated for use in corneal grafting are rejected because of signs of autolysis in the donor material. The purpose of this experimental study was to determine whether hydrocortisone acting as a lysosome membrane stabilizer could prevent or retard autolysis of the corneas under storage, and if so, what was the most efficacious concentration. Different groups of rabbit corneas were placed in saline as controls or in varying concentrations of hydrocortisone (10(-10) M to 10(-4) M at pH 7.4) at 37 degrees C and 4 degrees C. Acid phosphatase released after six hours was measured biochemically. This enzyme was used as a marker enzyme reflecting lysosomal labilization. Results showed a significant stabilization of the lysosomal membrane at 4 degrees C as compared to 37 degrees C. A trend towards stabilization of the lysosomal membrane was seen when 10(-8) M concentration of hydrocortisone at 37 degrees C was used, there being no demonstrable stabilization at 4 degrees C. |
132 | Cardiac output response to altered acid-base status during diethyl ether anaesthesia. | The effects of acid-base changes on cardiac output during diethyl ether anaesthesia were studied in 25 mongrel dogs prepared by surgically implanting a plastic encased non-ferrous core electromagnetic probe on the ascending aorta. The findings are: (1) Metabolic acidaemia produced only slight decrease in cardiac output but a more marked fall became evident with decreasing pH(2) Respiratory acidaemia led to a slight rise in cardiac output. (3) Respiratory alkalaemia decreased cardiac output. (4) Metabolic alkalaemia also produced a decline in cardiac output. |
134 | Respiratory effects of H+ and dinitrophenol injections into the brain stem subarachnoid space of fetal lambs. | Mock cerebrospinal fluid (pH 5.37-8.38) or 2,4-dinitrophenol (DNP) (0.15-1.5 mg) was injected into the subarachnoid space of the ventral brain stem of exteriorized fetal sheep. Changes in pH on the ventral surface of the medulla did not stimulate respiratory efforts or induce significant cardiovascular changes. The respiratory response to DNP injections ranged from no response to prolonged rhythmic ventilation that was independent of the peripheral chemoreceptors or the control arterial pH and blood gas tensions. This inconsistency suggests an effector site somewhat removed from the immediate surface of the medulla. The heart rate and blood pressure were not affected. It is concluded that increased H+ concentration in the extracellular fluid of the fetal ventral medulla does not initiate respiration, and any respiratory response to metabolic inhibitors applied to this area therefore is not attributable to a secondary change in surface pH. |
135 | Soil fungistasis: elevation of the exogenous carbon and nitrogen requirements for spore germination by fungistatic volatiles in soils. | Axenic, washed conidia of Fusarium solani f. sp. phaseoli, Aspergillus flavus, and Verticillium albo-atrum were placed on washed Difco purified agar discs along with an inorganic salt solution containing various levels of carbon and nitrogen substrates. These discs were exposed to volatiles from six soils (pH 5.1-8.6). Fusarium solani macroconidial germination was inhibited mostly by volatiles from soils of pH 5.1, 6.1, 7.0, and 7.5, but high levels of glucose and NH4Cl reversed this inhibition, raising germination to that of no-soil, no-carbon or nitrogen controls. Conidial germination of A. flavus was inhibited mainly by volatiles from high pH (7.0, 7.8, and 8.6) soils, and increased levels of glucose plus an amino acid mixture nullified this inhibition. Volatiles from soils of pH 5.1, 6.1, and 7.5 stimulated A. flavus conidial germination. Assays after the removal of CO2 from the air above soil of pH 5.1 demonstrated that volatiles inhibitory to A. flavus were produced by this soil. Assays indicated that a KOH-soluble compound was a fungistatic soil volatile to F. solani macroconidial germination. The nullification by carbon and nitrogen substrates of F. solani and A. flavus inhibition caused by soil volatiles parallels that for soil fungistasis. Conidial germination of V. albo-atrum was markedly stimulated by volatiles in all soils tested, and was not affected by removal of CO2. Inhibitory soil volatiles may increase the nutritional requirements for spore germination of certain fungi. |
136 | Nitrofurazone-reducing enzymes in E. coli and their role in drug activation in vivo. | Earlier work showed that Escherichia coli contains at least two enzymes which reduce nitrofurazone and other nitrofuran derivatives. One of these enzymes is lacking in some nitrofurazone-resistant mutant strains. We now report that there are three separable nitrofuran reductases in this organism: reductase I (mol. wt. approximately 50 000, insensitive to O2), reductase IIa (mol. wt. approximately 120 000, inhibited by oxygen), reductase IIb (mol. wt. approximately 700 000, inhibited by O2). Unstable metabolites formed during the reduction of nitrofurazone by preparations containing reductases IIa and IIb produce breaks in DNA in vitro. In vivo experiments with nitrofurazone-resistant strains, which lack reductase II but contain reductases IIa and IIb, demonstrated that lethality, mutation, and DNA breakage are all greatly increased when cultures are incubated under anaerobic conditions, i.e., conditions such that reductase II is active. These results provide further evidence for the importance of reductive activation of nitrofurazone. |
137 | Enzymatic hydrolysis of agar: purification and characterization of neoagarobiose hydrolase and p-nitrophenyl alpha-galactoside hydrolase. | The mixture of polysaccharides in the gelling component of agar (agarose) is hydrolyzed to D-galactose and 3,6-anhydro-L-galactose by a series of hydrolytic enzymes obtained from Pseudomonas atlantica. The final degradative step in the pathway of agarose decomposition is the hydrolysis of the alpha-linkage in the dissaccharide neoagarobiose yielding D-galactose and 3,6-anhydro-L-galactose. Pseudomonas atlantica when grown on agar produces two specific enzymes, p-nitrophenyl alpha-galactose hydrolase and neoagarobiose hydrolase. The purification and partial characterization of both enzymes are presented. |
138 | Temperature and pH optima for 21 species of thermophilic and thermotolerant fungi. | A glucose-containing mineral medium supplemented with 0.01% yeast extract is described upon which all the species of thermophilic and thermotolerant fungi tested will grow. Thirteen of the 21 species do not require the yeast extract supplement for growth. Using this solid, supplemented mineral medium, the pH and temperature optima for growth of all strains were measured. No correlation was found between temperature optimum and pH optimum among members of the group tested. |
139 | Physiological differences among isolates of Phytophthora cinnamomi. | Significant differences in amylase, beta-glucosidase, and phosphatase activities were observed among four Phytophthora cinnamomi isolates grown in nutrient-amended sterilized soil for 20 days. Amylase pH optima for the four isolates were within a relatively narrow range; at pH 5.5 each isolate was within 90% of its peak activity. Isolates SB-216-1, 1-281, and C-39 each exhibited maximal beta-glucosidase activity at pH 5.0 and maximal phosphatase activity at pH 5.0-5.5. Maximal activity for these two enzymes of isolate A-7725 occurred at pH 3.5. In timed experiments, isolates 1-281 and A-7725 exhibited greater amylase activities than did the other two isolates. For beta-glucosidase, greatest activity was observed for SB-216-1; ACTivity of 1-281 was intermediate and least activity was observed for isolates A-7725 and C-39. Isolates SB-216-1 and 1-281 exhibited greatest phosphatase activities; isolate C-39 was intermediate in activity, and A-7725 was least active. Results indicate that significant differences exist among the isolates tested and that these differences can be quantitatively measured by the methods described. |
140 | Regulation and properties of an invertase from Clostridium pasteurianum. | An intracellular invertase was induced in cultures of Clostridium pasteurianum utilizing sucrose as its carbon source for growth. This enzyme synthesis could be repressed by the addition of fructose of a sucrose-growing culture. In contrast, invertase activity was not affected by the addition of glucose to sucrose-growing cells and this enzyme could be induced in a glucose-metabolizing culture by the addition of sucrose. This enzyme was purified 10.5-fold over the induced lese, EC 3.2.1.26) by substrate-specificity studies. Invertase had a pH optimum of 6.5 and an apparent Km of 79.5 mM for sucrose, and required high concentration of potassium phosphate for maximum activity. Invertase was completely inactivated by a 2-min heat treatment at 60 degrees C. This enzyme was strongly inhibited by p-hydroxymercuribenzoate (pCMB) and weakly inhibited by 5,5'-dithiobis(2-nitrobenzoic acid), while cysteine could substantially reverse pCMB) inhibition, suggesting that sulfhydryl group(s) were necessary for invertase activity. |
141 | Characterization studies on the membrane-bound adenosine triphosphatase (ATPase) of Azotobacter vinelandii. | The adenosinetriphosphatase (ATPase) (EC 3.6.1.3) activity in Azotobacter vinelandii concentrates in the membranous R3 fraction that is directly associated with Azotobacter electron transport function. Sonically disrupted Azotobacter cells were examined for distribution of ATPase activity and the highest specific activity (and activity units) was consistently found in the particulate R3 membranous fraction which sediments on ultracentrifugation at 144 000 X g for 2 h. When the sonication time interval was increased, the membrane-bound ATPase activity could neither be solubilized nor released into the supernatant fraction. Optimal ATPase activty occurred at pH 8.0; Mg2+ ion when added to the assay was stimulatory. Maximal activity always occurred when the Mg2+:ATP stoichiometry was 1:1 on a molar ratio at the 5 mM concentration level. Sodium and potassium ions had no stimulatory effect. The reaction kinetics were linear for the time intervals studied (0-60 min). The membrane-bound ATPase in the R3 fraction was stimulated 12-fold by treatment wiTH TRypsin, and fractionation studies showed that trypsin treatment did not solubilize ATPase activity off the membranous R3 electron transport fraction. The ATPase was not cold labile and the temperature during the preparation of the R3 fraction had no effect on activity; overnight refrigeration at 4 degrees C, however, resulted in a 25% loss of activity as compared with a 14% loss when the R3 fraction was stored overnight at 25 degrees C. A marked inactivation (although variable, usually about 60%) did occur by overnight freezing (-20 degrees C), and subsequent sonication failed to restore ATPase activity. This indicates that membrane reaggregation (by freezing) was not responsible for ATPase inactivation. The addition of azide, ouabain, 2,4-dinitrophenol, or oligomycin to the assay system resulted in neither inhibition nor stimulation of the ATPase activity. The property of trypsin activation and that ATPase activity is highest in the R3 electron transport fraction suggests that its probable functional role is in coupling of electron transport to oxidative phosphorylation. |
142 | Effects of zinc-smelter emissions on forest soil microflora. | Within 2 km of a zinc (Zn) smelter in Palmerton, Pennsylvania, near the Lehigh Water Gap, up to 13.5% Zn by weight has been measured in the O2 horizon of the soil, and up to 8% Zn in the A1 horizon. The total numbers of bacteria, actinomycetes, and fungi (measured by dilution plate counts) were greatly reduced in the most severely Zn-contaminated soils compared with control soils. The reduction of microbial populations may be a partial cause of the decreased rate of litter decomposition at Lehigh Gap. Growth of most bacteria from control sites was reduced by 100 to 200 muM Zn, most actinomycetes by 100 muM Zn, and most fungi by 100 to 1000 muM Zn in thin-Pablum extract agar (TPab). All the tested actinomycetes and non-spore-forming bacteria isolated from Zn-contaminated Lehigh Gap soils were Zn-tolerant, growing normally in media containing 600-2000 muM Zn. Most fungi, regardless of source, were capable of at least 50% of normal growth at 700 muM Zn. Zinc-tolerant bacteria, actinomycetes, and fungi were readily isolated from low-Zn soils, suggesting that selection for Zn tolerance may proceed rapidly. Acidophilic Mortierella species have been selectively eliminated near the smelter, apparently because of elevated soil pH. Peryronellaea glomerata (Corda) Goidanich and Coniothyrium spp. were found only in the high-Zn soils. |
143 | alpha-Naphthoflavone activation of 6-hydroxymethylbenzo(alpha)pyrene synthetase. | alpha-Naphthoflavone activates the aryl hydroxymethyl synthetase of both the microsomal membrane-bound and soluble enzymes of rat liver and rat lung. The enzyme catalyzes the hydroxymethylation of benzo(alpha)pyrene to the 6-hydroxymethyl derivative. |
144 | Isolation and characterization of an unsubstituted 2,3-unsaturated sugar, trans-2,3-dideoxy-D-glycero-pent-2-enose, produced by thermal dehydration of 2-deoxy-D-erythro-pentose. | |
145 | Prophylactic antiarrhythmic drug therapy in acute myocardial infarction. | |
146 | [Influence of beta-blocking agents on experimental atherosclerosis of cocks (author's transl)]. | |
147 | Cytotoxic interaction between gorgonian explants: mode of action. | |
148 | The effects of the continuous administration of N,N-dimethyl-4-phenylazoaniline (DAB) on the activities and the inducibilities of some drug-metabolizing enzymes in rat liver. | (1) The effect of feeding a relatively low-protein diet containing 0.06% DAB for 29 weeks on the activity of DAB-azoreductase, nitroreductase (p-nitrobenzoic acid), N-oxidase (N,N-dimethylaniline), N-demethylase (DAB), cytochrome P-450, NADPH-cytochrome c reductase, beta-glucuronidase and arylsulphatase A were studied. Rapid decreases occurred in the activities of the first six enzymes, reaching minimal values at between 4 and 8 weeks. Activities then increased in all cases to control or nearly control levels. This rate of increase was least for cytochrome P-450. At 4 weeks azoreductase activity with the chemotherapeutic agent CB10-252 (I) as substrate was significantly higher than in control rats. Early increases occurred in the activities of beta-glucuronidase and arylsulphatase A and the activity of the latter never dropped below the control level. (2) An investigation was made of the differential effects of dye feeding on some of the enzyme activities in the two major liver lobes and differences were found. (3) The effect of phenobarbital (PB) pretreatment on the DAB-fed rats was studied at 4-week intervals. The activities of DAB-azoreductase and of nitroreductase increased throughout the whole period, while the activities of the lysosomal enzymes were decreased. (4) After feeding DAB for 4 weeks the effect of PB and 3-methylcholanthrene (MC) on the activities of DAB-azoreductase, CB10-252-azoreductase and components of the azoreductases-cytochrome P-450, NADPH-cytochrome c reductase, the CO-CB10-252-azoreductase was not induced by PB or MC, and CO did not inhibit its reduction. Its reduction depended only slightly on NADH. CO caused a greater relative decrease in the activity of DAB-azoreductase in dye-fed animals and also in animals following PB and MC pretreatment, implying a greater role of cytochrome P-450 in dye-fed animals. |
149 | Some characteristics of two azoreductase systems in rat liver. Relevance to the activity of 2-[4'-di(2"-bromopropyl)-aminophenylazo]benzoic acid (CB10-252), a compound possessing latent cytotoxic activity. | The system involved in the reduction of 2-[4'-di(2''-bromopropyl) aminophenylazolbenzoic acid (CB10-252), an agent designed for treating primary liver cell cancer, has been demonstrated to be localised mainly in the 108 000 X g supernatant fraction of rat liver homogenate. It is also present in other organs particularly in the spleen. DAB-azoreductase as shown previously is present almost entirely in the microsomal fraction and is found in high concentration only in liver. The pH maximum for CB10-252-azoreductase implying the importance of the 2'-carboxyl group in determining substrate specificity. The use of enzyme inhibitors and other additives showed that CB10-252 WAS NOT AXANTHINE OXIDASE OR DIHYDROFOLATE REDUCTASE. Its activity was not affected by carbon monoxide, phenobarbitone (PB), or 3-methylcholanthrene (MC) pretreatment. Enhancement of the activity by ferrous ions and FAD indicated that at least part of the reduction system could involve a flavoprotein with FAD as the prosthetic group. The activity of CB10-252-azoreductase and methylred-azoreductase was reduced by menadione (vitamin K3), cyanide and propylgallate. A diaphorase preparation from pig heart reduced both CB10-252 and methylred with both NADPH- and NADH-generating systems. |
150 | Mercury inhibition of avian fatty acid synthetase complex. | (1) Subcutaneous or intra-abdominal injections of 8 mg of HgCl2/100 g body weight markedly depressed hepatic fatty acid synthetase activity of chicks at 1 h post-injection. The depression occurred despite the fact that the chicks continued to eat up until the time they were killed. Under these same conditions, the hepatic activity of acetyl-CoA carboxylase (EC 6.4.1.2) was not affected by HgCl2, while the activity of the mitochondrial system of fatty acid elongation was stimulated. (2) When 2-mercaptoethanol was included in the incubation medium for a highly purified preparation of fatty acid synthetase, 500 muM HgCl2 was required to show definite inhibition of the enzyme. When 2-mercaptoethanol was omitted, 50 muM HgCl2 was inhibitory and 100 muM HgCl2 abolished enzyme activity. (3) 2 mM dithiothreitol completely protected the purified fatty acid synthetase preparation from inhibition by 100 muM HgCl2. When dithiothreitol was added after the addition of enzyme to the mercury-containing medium, protection of the enzyme was not complete. (4) Dialysis of cytosol fractions from chicks injected with HgCl2 against 500 vol. of 0.2 M potassium phosphate buffer (pH 7.0) containing 1 mM EDTA and 10 mM dithiothreitol for 4 h at 4 degrees stimulated the fatty acid synthetase activity of the fractions. Dialysis of cytosol fractions from noninjected chicks under the same conditions was without effect on fatty acid synthetase activity. (5) These data support the hypothesis that the inhibitory effect of HgCl2 administered in vivo on hepatic fatty acid synthetase activity in chicks is mediated through the interaction of mercury with the sulfhydryl groups of the enzyme. |
151 | [Basic phospholipase of Naja nigricollis venom]. | It is confirmed that N. nigricollis venom contains several phospholipases one of these is a basic phospholipase A. This enzyme is toxic for mice when injected intravenously. In vitro it reacts on egg yolk lecithin producing lysolecithin and prevents the phenomenon of blood clotting. An immunological identity has been established between this basic phospholipase and two acidic phospholipases present in the same venom. |
152 | [Spontaneous mortality and vascular lesions in 3 rat strains with different blood pressure levels]. | We have observed a high and significant mortality in spontaneously hypertensive rats compared to normotensive and hypotensive controls, in the fifth generation. The hypertensive rats exhibited a high frequency of cerebral haemorrhage and periarteritis nodosa. |
153 | Effects of decreasing arterial blood pressure on cerebral blood flow in the baboon. Influence of the sympathetic nervous system. | 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. |
154 | Influence of hematocrit, blood gas tensions, and pH on pressure-flow relations in the isolated canine lung. | An isolated perfused canine lung preparation in which determinants of vascular caliber could be individually controlled was developed. The relation of pulmonary arterial (Pa), venous (PV), and alveolar (PA) pressures was such that Pa greater than PA greater than PV throughout the whole lung. The addition of isoprenaline to the perfusate abolished vascular reactivity. Once stability was reached, vascular cross-sectional area remained acceptably constant for 2.25 hours as judged by normalized conductance. The influence of perfusate hematocrit, blood gas tensions, and pH on pressure-flow relations was then studied in 15 isolated canine lungs. The hematocrit-vascular conductance relation was derived at constant perfusion pressure. Conductance varied linearly with hematocrit over a range of 16.5 to 89.5%. Mean pulmonary arterial blood gas tensions were: PO2 = 121 mm Hg, PCO2 = 28 mm Hg, and pH = 7.46. Acute respiratory acidosis (PO2 = 30 mm Hg, PCO2 = 81 mm Hg, pH = 7.17) and lactic acidosis and hypoxemia (PO2 = 32 mm Hg, PCO2 = 21 mm Hg, pH = 6.96) did not significantly alter this relation. Transformation of the conductance-hematocrit data indicated that hematocrit was the most important determinant of relative apparent viscosity of the blood. Both acute respiratory and lactic acidosis failed to significantly increase relative viscosity within the range of hematocrit usually found in secondary polycythemia. |
155 | Interaction of the chemoreflex and the pulmonary inflation reflex in the regulation of coronary circulation in conscious dogs. | The interaction of chemoreflex and pulmonary inflation reflex control of the coronary circulation was examined in conscious dogs by comparing the responses to chemoreflex stimulation (intracarotid injection of nicotine) when ventilation was allowed to increase with those when ventilation was controlled. The responses were also compared with those elicited by both forced mechanical and spontaneous hyperinflation. When the heart rate was constant, intracarotidly administered nicotine induced an increase in the depth of respiration followed closely by an increase in late diastolic coronary flow from 48 +/- 2 to 106 +/- 8 ml/min and a reduction in late diastolic coronary resistance from 1.62 +/- 0.08 to 0.78 +/- 0.06 mm Hg/ml min-1. After beta-receptor and cholinergic blockade, a similar coronary dilation in response to nicotine occurred only when ventilation was allowed to increase. However, when ventilation was controlled, intracarotidly administered nicotine increased coronary resistance after combined beta-receptor and cholinergic blockade. The reflex coronary dilation was not observed after carotid sinus nerve section or after alpha-receptor blockade. Thus, nicotine stimulation of the carotid chemoreflex results in a striking coronary dilation that has two components. The minor component involves a chemoreflex with its efferent pathway in tthe vagi. The major component of coronary dilation follows an increase in the depth of respiration, and its efferent component appears to involve withdrawal of alpha-adrenergic constrictor tone. An almost identical period of reflex coronary dilation followed either forced mechanical or spontaneous hyperinflation in the conscious dog. |
156 | Effect of coronary blood flow on glycolytic flux and intracellular pH in isolated rat hearts. | The rate of coronary blood flow was varied in isolated working rat heart preparations to determine its influence on the rate of glocose utilization, tissue high-energy phosphates, and intracellular pH. A 60% reduction in coronary blood flow resulted in a 30% reduction in oxygen consumption, an accelerated rate of glusoe utilization, lower tissue levels of high-energy phosphate, and higher tissue levels of lactate and H+. Ventricular performance deteriorated as reflected by a decrease in heart rate and peak systolic pressure. Further reductions in coronary blood flow resulted in inhibition of glycolysis, a greater decrease in tissue levels of high-energy phosphates, and higher tissue levels of both lactate and H+. These changes in glycolytic flux, tissue metabolites, and ventricular performance were proportional to the degree of restriction in coronary blood flow. The importance of coronary blood flow and washout of the interstitial space in the maintenance of accelerated glycolytic flux in oxygen-deficient hearts is emphasized. It is concluded that acceleration of ATP production from glycolysis can occur only in the marginally ischemic tissue in the peripheral area of tissue supplied by an occluded artery. The central area of tissue which receives a low rate of coronary blood flow will have a reduced rate of ATP production due to both a lack of oxygen and an inhibition of glycolysis. |
157 | Mechanisms of glycolytic inhibition in ischemic rat hearts. | The mechanisms of glycolytic inhibition in ischemic myocardium were investigated in the isolated, perfused rat heart. Glycolysis was inhibited at the level of glyceraldehyde-3-phosphate dehydrogenase. The major factors that accounted for the glycolytic inhibition in the ischemic heart compared with the anoxic heart appeared to be higher tissue levels of lactate and H+ in the ischemic tissue. Increased extracellular pH inhibited glycolysis in anoxic and hypoxic hearts much more readily than it did in aerobic hearts. However, maintenance of both extracellular and intracellular pH caused only a modest acceleration of glycolysis in ischemic hearts. Accumulation of tissue lactate and inhibition of glycolysis were directly proportional to the reduction in coronary bloow flow in both anoxic and ischemic hearts. At intracellular lactate concentrations between 15 and 20 mM, glycolysis was inhibited under both conditions. Addition of either 10, 20, or 40 mM lactate to the perfusate inhibited glycolysis in aerobic, anoxic, and ischemic hearts. The effect of lactate did not appear to be mediated through changes in intracellular pH. It is concluded that accumulation of lactate represents a major factor in the inhibition of glycolysis that develops in ischemic hearts. |
158 | Comparison of contractile performance of canine atrial and ventricular muscles. | 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. |
159 | Serum lactate dehydrogenase activity ratios with different substrates. | 1. The lactate dehydrogenase activity of 89 sera from patients suffering myocardial infarction and of 55 sera from patients with hepatocellular damage was assayed under optimal conditions using pyruvate, alpha-oxobutyrate, hydroxypyruvate and glyoxylate as substrates. Activity was also measured with lactate as substrate at different pH values. 2. The ratios of activities under these different assay conditions were calculated for both series of patients. Correct differentiations for single ratios ranged from virtually nil for hydroxypyruvate/alpha-oxobutyrate to is greater than 93 per cent for glyoxylate/hydroxypyruvate and glyoxylate/alpha-oxobutyrate. This was little improved by the use of multiple ratios involving up to seven separate assays. 3. The activity ratio of hydroxypyruvate to pyruvate which is consistently greater than unity was found to be inverted in a case of morphine poisoning. |
160 | Fluorometric assay for N-acetylprocainamide. | We describe a simple, rapid fluorometric assay for separate quantitative analysis of procainamide and N-acetylprocainamide in mixtures. The effective lenear range (fluorescence vs. concentration) in serum is 0.1 to 10.0 mg/liter, regardless of the ratio (by weight) of the two drugs from 1:10 to 10:1. Analytical recoveries by the extraction method used were 100.0 +/- 3.0% and 98.0 +/- 4.0%, respectively. For determination of either compound, the maximum coefficient of variation was 10%. |
161 | Rapid kinetic measurement of lactate in plasma with a centrifugal analyzer. | In this method, blood is collected in ammonium heparinized microhematocrit tubes and lactate is directly determined in the plasma, separated within 15 min from the erythrocytes. Lactate is assayed by mixing 10 mul of sample with NAD+ and lactate dehydrogenase in tris(hydroxymethyl)aminomethane hydrazine buffer. The rate of increase in absorbance of the NADH formed, measured at 340 nm, is proportional to lactate concentration. The assay is complete in 4 min and absorbance is linearly related to concentration from 0.625 to 15 mmol/liter. Analytical recoveries of lactate added to plasma averaged 104% (range, 91-116%). Results compared well for plasma samples analyzed by this method with the CentrifiChem and the Du Pont aca. |
162 | Improved high-resolution high-voltage paper electrophoresis system for use in screening for aminoacidopathies. | High-voltage paper electrophoresis of small samples of serum and urine at pH 6.0 resolves basic and acidic amino acids and separates them from the neutral amino acids. For separation and identification of the neutral amino acids, the appropriate area of the electrophoretogram is cut out, sewn onto a second sheet of paper, and rerun at pH 1.9. By this method, amino acids are rapidly resolved. It is suited for use with special procedures such as oxidation of biological fluid with performic acid and specific staining for confirmation of amino acid identification. |
163 | Measurement of total alkaline phosphatase activity in human serum. | |
164 | Problems associated with the determination of arylsulfatase A and B using nitrocatechol sulfate substrate. | |
165 | A clinical method for the determination of serum gamma-glutamyl transpeptidase. | A simple, highly sensitive and reproducible method for the assay of gamma-glutamyl transpeptidase (EC 2.3.2-) activity is introduced, using gamma-glutamyl-p-nitroanilide as a substrate and glycylglycine as an acceptor in 50 g/l of polyoxyethylene nonylphenol. Serum transpeptidase activity was assayed in 1080 healthy adults, the normal mean value being 14.8 mU/ml. The diagnostic evaluation of the enzyme in various hepatobiliary diseases is also discussed. |
166 | [Inborn error of glycolipid metabolism]. | |
167 | Treatment of renal hypertension. | There are different types of renal hypertension: hypertension due to parenchymal renal disease, renovascular hypertension, hypertension due to urological disease, hypertension of endstage renal disease. Treatment has to consider-above all-the possibility of specific, medical or surgical procedures that may cause the underlying condition. If the underlying disease is not amenable to specific therapy, symptomatic medical treatment to lower blood pressure is indicated: besides control of sodium-intake and body weight antihypertensive drugs are generally indicated. We use them, alone or in combination, in the following line of order: diuretics, beta-adrenergic blockers, dihydralazine, reserpine, clonidine, alpha-methyldopa, guanethidine. |
169 | Some pharmacologic aspects of the antihistamines. A survey of current clinical applications. | |
170 | Anaerobic glycolysis in normal human erythrocytes incubated in vitro with sodium salicylate. | 1. Some effects of sodium salicylate upon anaerobic glycolysis have been studied in normal human erythrocytes incubated for up to 6 h at 37 degrees C in autologous sera. 2. Both glucose consumption and lactate production were stimulated by concentrations of salicylate up to 60 mmol/l but at the highest concentration used (90 mmol/l) an initial stimulus was followed by inhibition of glycolysis. 3. Losses occurred of adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP) and adenosine 5'-phosphate(AMP)at higher concentrations of salicylate and there was a concomitant increase of inorganic phosphate. 4. Other phosphate esters underwent concentration changes at higher concentrations of salicylate that reflected inadequate concentrations of ATP for glycolysis. 5. The rates of sodium efflux from, and potassium influx into, erythrocytes were unaffected by the presence of salicylate at concentrations sufficient to stimulate glycolysis. |
171 | Arterial catecholamines in hypoxic exercise in man. | 1. We measured the minute ventilation and arterial blood catecholamine concentrations in four normal men standing and at two levels of moderate treadmill exercise breathing 14% oxygen or air. 2. Minute ventilation was significantly higher during hypoxic exercise than during normoxic exercise at an oxygen uptake of 1500 ml/min. 3. Arterial plasma noradrenaline during hypoxic exercise at an oxygen uptake of 1500 ml/min was significantly greater than at rest. 4. Arterial plasma noradrenaline during normoxic exercise at an oxygen uptake of 1500 ml/min was not elevated above the resting concentration. 5. The results are compatible with the suggestion that increased concentrations of arterial plasma noradrenaline contribute to the hypoxic potentiation of the respiratory response to moderate exercise. |
168 | Effects of graded infusions of monomethylmethacrylate on coagulation, blood lipids, respiration and circulation. An experimental study in dogs. | In 4 dogs injected intravenously (i.v.) with 125I labeled fibrinogen, 51Cr labeled platelets and 99mTc labeled albumin, and subjected to successively increasing amounts of i.v. infused monomethylmethacrylate, doses corresponding to the amounts released into the blood stream following implantation of acrylic cement during total hip replacements did not affect the clotting mechanism, did not cause trapping of platelets and fibrin in the lungs, did not generate fat emboli, and did not cause depression of the arterial oxygen tension or blood pressure. Monomethylmethacrylate in whole blood was associated with both blood cells and plasma. |
172 | Meal to pellet intervals in 14 species of captive raptors. | |
173 | Secretion of sulfuric acid in Cassidaria echinophora Lamarck (Mollusca: Mesogastropoda, marine carnivorous snail). | |
174 | Studies on the lipid content of pigeon breast muscle. | |
175 | Seasonal variation in diet, volatile fatty acid production and size of the cecum of roch ptarmigan. | |
176 | The auditory system of the goldfish (Carassius auratus): effects of intense acoustic stimulation. | |
177 | Volatile fatty acids and metabolizable energy derived from cecal fermentation in the willow ptarmigan. | |
178 | A comparison of intestinal amino acid absorption in various avian and mammalian species. | |
179 | Holeuryhalinity and its mechanisms in a cirriped crustacean, Balanus improvisus. | |
180 | A comparative study on the regulation of osmotic, ionic and organic-solute concentrations in the blood of aquatic organisms. | |
181 | Aestivation and thermoregulation in the Texas tortoise, Gopherus berlandieri. | |
182 | The respiratory quotient of Gammarus pulex L. | |
183 | Water balance of small lactating rodents--II. Concentration and composition of milk of females on ad libitum and restricted water intakes. | |
184 | Insect morphogenetic hormones and developmental mechanisms in the nematode, Nematospiroides dubius. | |
185 | Osmotic interrelationship between blood and gut fluid in the isopod Porcellio scaber Latr. (Crustacea). | |
186 | Effects of thermal stimulation to the spinal cord on heart rate in cyprinid fishes. | |
187 | The long-term monitoring of ventilation rhythms of the polychaetous annelid Nereis virens sars. | |
188 | Diving bradycardia in four species of North American aquatic snakes. | |
189 | Respiratory responses of Gillichthys mirabilis to changes in temperature, dissolved oxygen and salinity. | |
190 | The pronephroi as the site of presumptive interrenal cells in the hagfish Myxine glutinosa L. | |
191 | Excreta analysis on additional cockroach species and the house cricket. | |
192 | Interrelationships between water and metabolism in Artemia cysts--II. Carbohydrates. | |
193 | Interrelationships between water and metabolism in Artemia cysts--III. Respiration. | |
194 | Studies on avian erythrocyte metabolism--I. Procedure for separation and quantitation of the major phosphorylated metabolic intermediates by anion exchange chromatography. | |
195 | Effect of different prostaglandins on the permeability of the toad urinary bladder. | |
196 | Evaluation of amplitude and frequency changes of miniature potentials with a poor signal-to-noise ratio. | |
197 | Practolol, caffeine and calcium in the regulation of mechanical activity of the cardiac ventricle in Myxine glutinosa (L.). | |
198 | Asymmetric distribution of aspartate in ganglia and single neurons of Aplysia. | |
199 | Electrophysiological actions of convulsants and anticonvulsants on neurons of the leech subesophageal ganglion. | |
200 | The relative importance of monoamine oxidase and catechol-O-methyl transferase on the physiologic response to administered norepinephrine in the turkey. |