[Peridural anesthesia and cesarean section. Apropos of 117 cases]. One hundred and seventeen caesarean sections performed under epidural anesthesia are reported. Following localization by air myelography, catheterization of the epidural space was performed in all cases. The estimated level of injection was L 1.76 +/- 0.82. The local anesthetic used was: lignocaine 2 p. 100 with adrenalin 1/160,000 (N = 13) in a dose of 388 mg +/- 81.4; bupivacaine 0.5 p. 100 with adrenalin 1/2000,000 (N = 77) in a dose of 106.6 mg +/- 20; or a mixture of bupivacaine 0.5 p. 100 with adrenalin 1/200,000 and lignocaine 2 p. 100 without adrenalin (N = 27) at doses of 91.0 mg +/- 23.9 and 238 mg +/- 53.4 respectively. The failure rate was 5.97 p. 100 and the operative conditions were satisfactory in 91.5 p. 100 of cases. Apgar scores were greater than 7 in 87 p. 100 of cases at one minute and 99 p. 100 of cases at 5 minutes. The proportion of minor incidents was 30 p. 100, and of complications 3.5 p. 100. Their prevention and treatment and the anesthetic protocol are discussed.


[Resuscitation of the elderly brain].

[Resuscitation of the elderly brain]. The little poses the question of the usefulness of resuscitation of elderly individuals, victims of cerebral damage or aggression. The author reviews the difficulties inherent in the definition of the "elderly patient" and the "elderly brain". The results obtained in 195 patients aged 60 or over are reported. In a 12 month period, this accounted for 32.77 p. 100 of "resuscitated" patients in a department of neurosurgery. Resuscitation implied a state of coma with artificial ventilation for varying periods. It thus differed from simple surveillance, even specialised. Survival rates are analysed in terms of neurological state, aetiology, whether or not there was surgery under general anaesthesia, past history, complications and the gravity of the resuscitation methods employed. The overall rate of 32.31 p. 100 was already lower than that in the elderly in a general intensive care unit. The picture in geriatric neurological resuscitation worsens further if only good quality survivals are noted: approximately 21.03 p. 100. Nevertheless, all the indications are that these figures are likely to improve in this recent field of resuscitation.


[Gas gangrene caused by venous catheterization (apropos of a case)]. A case of fatal gas gangrene occurring after venous catheterization and the administration of sympathomimetic amines is reported. Following a brief discussion, the necessity of observing strict asepsis during the insertion and care of the catheter and of always ensuring that the tip of the catheter is in a large vein is emphasized.


[Experimental hepatic ischemia].

[Experimental hepatic ischemia]. Total clamping of the hepatic pedicle was performed for a period of two hours in the normothermic pig. During this time an external pulsed spleno-jugular shunt ensured effective-portal decompression. Under such conditions, the biological and histological consequences of this ischaemia were minimal and perfectly compatible with survival. This would suggest that the clinical syndrome of "shock liver" above all reflects splanchnic impairment.


[A case of succinylcholine apnea. Identification of genetic variants]. A report of a case of prolonged apnoea after succicurarium in a female patient with abnormal pseudo-cholinesterases is followed by a presentation of a study of pseudo-cholinesterases in 12 members of the family. The value of the use of 4 tests of inhibition of cholinesterase activity in determining the genotype of an individual is emphasised.


[Preoperative arrhythmias in ophthalmological surgery]. Continuous ECG recording (Holter technique) was carried out in 25 patients undergoing similar ophtalmological surgery for retinal detachment. The patients were selected at random and divided into two groups. Premedication (alimemazine 25 mg. atropine 0.5 mg given one hour before the operation) and induction (penthiobarbital 4 mg.kg-1 and succinylcholine iodide 1 mg.kg-1) were given in the same way. General anaesthesia was maintained in Group I (n = 12) with halothane and in group II (n = 13) using neuroleptanalgesia. There was no significant difference in the percentage of arrhythmias between the two groups. There was a remarkablly high prevalence of sinus bradycardia and ventricular pauses (8/25). The respective role of atropine and of retrobulbar local anaesthesia in prevention is discussed in the light of data from the literature. If arrhythmias occurring at the time of intubation are included, the total percentage of rhythm disturbances was 80 p. 100 (20/25).


[Double blind randomized trial of metopimazine: for postoperative nausea and vomiting after cholecystectomy]. Eighty-four patients submitted to cholecystectomy were randomly assigned in a double-blind study either to an intravenous dose of 10 mg of metopimazine, three times D-1, for two days or to an identically administered placebo. A definite superiority of metopimazine as an anti-emetic drug was demonstrated. General acceptance was excellent, but arterial pressure might be looked over closely when metopimazine was administered intravenously immediately after a general anesthesia.


[Peritoneal irrigation and lavage using iodinated polyvinyl-pyrrolidone in acute generalized peritonitis (70 cases treated in an intensive care unit)]. The authors report 70 cases of severe acute generalise peritonitis treated during the immediate postoperative periode by peritoneal irrigation-lavage using iodinated polyvinyl-pyrrolidone for 16 days. All of the patients were hospitalised in an intensive care unit because of septicaemia, respiratory distress, acute renal failure, etc. After an aetiological study of these cases of peritonitis, the technique of installation and surveillance and the complications of peritoneal irrigation-lavage are analysed. The results in this series confirm the efficacy of the technique as long as it is used from the outset, immediately following the onset of peritonitis.


[Harmful interference between preoperative prophylactic cardiac pacemaker and cutting diathermy. Case report]. The authors report the case of a patient suffering the consequences of harmful preoperative between a prophylactic cardiac pacemaker system and cutting diathermy, resulting in irreversible ventricular fibrillation. After reviewing the different mechanisms responsible for this accident, they attribute the blame to a phenomenon of capture of electromagnetic currents with the pacemaker catheter playing the role of an aerial. They reconsider the indications for the use of prophylactic pacing and recall the safety precautions which must be respected at the time of simultaneous use of an external pacemaker and cutting diathermy.


[The liver in shock. Generalities: historical, etiology, clinical, physiopatholical, treatment]. On the basis of personal experience of 89 cases, the authors give a general review of shock liver, considering in turn historical, aetiological, clinical and physiopathological features of this syndrome. They complete their studies by defining the basis of treatment. One hundred bibliographic references.


[Histopathology of the liver in shock].

[Histopathology of the liver in shock]. Microscopic lesions in shock liver, examined in biopsy specimens from 20 patients, are characterised by elective involvement of the hepatic parenchyma inthe peripheral zones of the acini, with necrosis and cell loss in approximately half the cases. The particular appearance of the degenerative lesions of the hepatocytes ("ischaemic atrophy" and tumefaction, monocellular necrosis), the absence of any change in the reticulin fibres, the minimal leucocytic reaction and the absence of any damage to the portal spaces should make it possible to identify histologically the ischaemic aetiology of peri-acinar hepatic lesions.


[Ultrastructural pathology of the liver in shock]. Ultrastructural findings in shock liver are in general very similar to data in the literature concerning experimental ischaemia in the animal. It is firstly a cellular disease which leads to a tissue disease, reflected morphologically by definitive and irreversible signs in the absence of hepatocellular regeneration. Assessment on the cellular scale of lesions of ischaemia may be used to define the potentially reversible nature of certain signs and should be adpated to the study of the cellular effects of therapeutic measures. By contrast, in practical terms it cannot be used for the quantitative assessment of the spatial extent of lesions within the hepatic acinus.


Intracecal endotoxin and lactate during the onset of equine laminitis: a preliminary report. Cecal fluid from two adult horses was assayed by the limulus amebocyte lysate system for endotoxin before and after carbohydrate overload of the gastrointestinal tract. There were increases in cecal fluid endotoxin concentrations at the 3-, 6-, and 12-hour samplings when compared with base-line values. Concomitant cecal fluid lactate concentrations and pH values increased and decreased, respectively. Both horses subsequently developed clinical signs of acute laminitis.


Direct binding studies of adrenergic receptors: biochemical, physiologic, and clinical implications. Recently developed radioligand binding techniques permit direct investigation of the alpha- and beta-adrenergic receptors for catecholamines in a wide variety of tissues. These techniques allow the receptors to be quantitated, characterized, and studied under varying conditions of physiologic and pathophysiologic interest. They are providing fresh insights into the mechanisms by which endogenous catecholamines and other hormones regulate the properties of the adrenergic receptors and, in turn, control tissue sensitivity to catecholamine action.


Quality of patient care by nurse practitioners and physician's assistants: a ten-year perspective. A remarkable development in primary care is the recent emergence of a new class of health professional: nurse practitioners and physician's assistants. These practitioners diagnose and treat a wide variety of medical problems, usually with supervision by physicians. Their clinical competence has been evaluated in over 40 studies. Twenty-one studies in which care given by nurse practitioners or physician's assistants was directly compared with that given by physicians are analyzed. These studies show that nurse practitioners and physician's assistants provide office-based care that is indistinguishable from physician care. Because these studies were limited in scope, there is no experimental basis for extending this conclusion to care given outside the office, care that is unsupervised, or care of the seriously ill patient.


Muscular dystrophy in the mouse: neuromuscular transmission and the concept of functional denervation. The results of recent investigations by ourselves and others indicate that no form of denervation exists to any remarkable degree in dystrophic mouse skeletal muscles. This conclusion is based on the following information: Dystrophic nerve terminals liberate normal amounts of transmitter both spontaneously and during impulse-mediated activity. The characteristics of the release process, the size of the available store of transmitter, and the probability of release of transmitter in response to the invasion of an action potential appear to be normal. The sensitivity of the postsynaptic membrane to the transmitter is normal. Action potential generation in response to both direct and indirect excitation is normal. There is no unequivocal pharmacologic evidence of denervation in dystrophic skeletal muscle, even though dystrophic muscle fibers respond to surgical denervation in a normal fashion. Nerve terminal sprouting is extensive, but there is no evidence of collateral reinnervation.


[Elimination of aflatoxin B1 by clays from contaminated substrates]. It has been proved that clays were able to absorb aflatoxin B1. The amount of adsorbed aflatoxin depended on the nature of clay. The adsorbing power of the clays was checked in relation to some environmental factors. From this study, it is claimed that clays are suitable for détoxification of liquid food-stuffs poisoned by aflatoxin.


[Chronic urticaria. Etiologic and therapeutic evaluation of 150 cases. (author's transl)]. The study of one hundred and fifty cases of chronic urticaria observed, gave the following results: higher female frequency, usual beginning at adult age, relative absence of digestive problems. For the last of these results we nevertheless noted numerous insignificant functional features, a few examples of colitis, a number of cases of non-functioning gall-bladder. Frequency of sensitivity to foods, preservatives, colouring agents, medical substances, principally shown by provocation tests (the latter present a considerable interest, and merit frequent use); importance of bacterian, mycotic, parasitic origins; little importance of atopy; frequency of minor psychogenic disorders. A contributing role might be played by spasmophily. The therapy includes the following basic treatment; antihistaminic drugs (mainly hydroxyzine hydrochloride and cyproheptadine hydrochloride) and a diet which eliminates recognized urticaria causing foods. In addition, a supplementary treatment destined to eliminate the factors shown to be responsible for the outbreak, must be prescribed.


[Cutaneous reactions to propranolol (author's transl)]. A 17-year-old male patient with eczematous and psoriasiform eruption that developed during long-term therapy with Propanolol (Avlocardyl) has been studied. This eruption disappeared after removal of the drug; oral challenge was soon followed by a vesiculous and bullous eruption of face and extremities; five months later, sun exposure was followed by a severe eczematous eruption in these areas; nails changes were then observed. Most of side-effects of beta-adrenergic blocking drugs have been reported with Practolol: lichenoid, exanthematous, eczematous, psoriasiform rashes; exfoliative dermatitis; oculo-muco-cutaneous reactions; fibrosing polyseritis and drug induced systemic lupus erythematosus manifestations. Adverse effects of other beta-adrenergic blocking agents are less frequent. The pathogenetic mechanism responsible for these adverse reactions is still obscur: these changes might be caused by blockade of the epidermal cells (and T-lymphocytes) beta-receptors, more than by a direct immunologic, allergic or toxic mechanism.


[Renal acidification disturbance in vitamin D deficiency (author's transl)]. Extensive studies of renal acidification process have been performed in states of vitamin D deficiency. Results show that the process of hydrogen ion excretion is strongly impaired on the entire length of the nephron. Vitamin D and parathyroid hormone probably interfere within tubular cells regulating the concentration of calcium and cyclic AMP; the modification of such an equilibrium carried out by vitamin D deficiency would explain the renal dysfunction.


[General meeting of the Belgian Society of Endocrinology and of the Endocrine Pancreas Contact Group of the Scientific Medical Research Foundation. Session of November 18, 1978]. Rats are fed during 18 months with normal diet or diet enriched with 25% of many fats; half of these diets are enriched with 25% sucrose. The hyperglycemic curve is elevated by the female on diets enriched with sucrose and beef fat or sucrose and M.C.T. The insulinemia is higher by the males on diet enriched with beef fat and sucrose and by the female on diet enriched with beef fat and sucrose.


Inhibitory effects of anticonvulsant drugs on cyclic nucleotide accumulation in brain. Veratridine causes deplorization of excitable cells and produces marked elevation of adenosine 3',5'-monophosphate (cyclic AMP) and guanosine 3',5'-monophosphate (cyclic GMP) levels in incubated slices of mouse cerebral cortex. Phenytoin, carbamazepine, phenobarbital, primidone, phensuximide, methsuximide, alpha-methyl-alpha-phenylsuccinimide, and high concentrations of clonazepam are anticonvulsant drugs that preferentially prevent maximal electroshock seizures (MES) and generalized tonic-clonic convulsions; all these agents inhibit veratridine-induced accumulation of both cyclic AMP and cyclic GMP. In contrast, ethosuximide, trimethadione, valproic acid, and low concentrations of clonazepam are anticonvulsant drugs that act predominantly against Metrazol and absence seizures; these agents are ineffective or inhibit accumulation of only cyclic GMP. The results suggest that inhibition of cyclic AMP and cyclic GMP accumulation in depolarized brain tissue is a molecular neuropharmacological action characteristic of anticonvulsant drugs that have direct effects on cellular membrane function and prevent MES. Anticonvulsant drugs that do not inhibit accumulation of both cyclic AMP and cyclic GMP in depolarized brain tissue preferentially prevent Metrazol and absence seizures and probably exert their effects by altering neurotransmission mechanisms.


Intracellular redox states under halothane and barbiturate anesthesia in normal, ischemic, and anoxic monkey brain. Cortical reflectance, mean arterial blood pressuees, electroencephalograms, and cortical blood flow were continuously recorded together with fluorescence of reduced pyridine nucleotides (PN) at various carbon dioxide tensions before, during, and following middle cerebral artery occlusion in 10 squirrel monkeys receiving halothane or babiturate anesthesia. Measurements were continued through a nitrogen breathing cycle and to death produced by anoxia. The anesthetic agent produced no detectable differences in PN fluorescence in cerebral tissue during ischemia and anoxia. The known cerebral protective action of barbiturates is apparently unrelated to the intracellular redox state.


Bactericidal and bacteriostatic action of chloramphenicol against memingeal pathogens. The bacteriostatic and bactericidal effects of chloramphenicol, ampicillin, tetracycline, and sulfisoxazole were compared against several potential meningeal pathogens. Chloramphenicol is bactericidal at clinically achievable concentrations against Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis. It is bacteriostatic against gram-negative bacilli of the family Enterobacteriaceae and against Staphylococcus aureus. Chloramphenicol has proven highly efficacious in the treatment of bacterial meningitis caused by those organisms against which it is bactericidal at low concentrations. Because leukocytic phagocytosis in the subarachnoid space is inefficient, we propose that bactericidal activity in cerebrospinal fluid is important for optimal therapy of bacterial meningitis. Chloramphenicol does not provide such activity in meningitis caused by enteric gram-negative bacilli.


Histochemistry in psoriasis. 5'-Nucleotidase in psoriatic parakeratotic horny layer. The 5'-nucleotidase activity in psoriatic and normal human epidermis was studied in comparison to acid phosphatase activity. The optimum pH in normal human epidermis was about 5.0 at room temperature. The activity of both enzymes was found to be high in the transitional zone. Acid phosphatase (non-specific) activity was strongly positive in the psoriatic parakeratotic horny layers whereas 5'-nucleotidase activity in that area was completely absent. The results suggest that the enzyme which degrades nucleoside-5'-phosphate to nucleoside and inorganic phosphate is not acid phosphatase but 5'-nucleotidase. Nuclear preservation in psoriatic hyperkeratosis was attributed to absence or inactivation of specific enzymes of nuclear degradation, such as 5'-nucleotidase, rather than acid phosphatase.


Potentiation of the response of rat vas deferens to noradrenaline by dicylohexylamine and related amines. The results of a previous study on protection by propranolol and dicyclohexylamine of alpha-blockade suggested that these compounds potentiated the response of the isolated rat vas deferens to noradrenaline. A number of structural analogues of dicyclohexylamine (DCHA) have now been investigated for their effects on noradrenaline responses and some of them have been shown to potentiate these responses. At concentrations approaching those necessary to achieve maximum potentiation they also brought about the spiked contraction of the vas deferens. The potentiating effects of these amines are discussed together with their relevance to the protection of alpha-blockade.


Effects of beta adrenergic blocking agents upon thermal trauma induced cardiovascular changes. The cardiovascular changes induced by 15% total body surface area 3 degrees burn have been studied in dogs anesthetized with sodium pentobarbital. The responses observed were a decrease in plasma volume, a decrease in cardiac output, and a slight but insignificant fall in mean arterial blood pressure. Beta adrenergic blockage with propranolol prior to thermal trauma reduced the plasma volume loss, increased the depression of cardiac output, and caused a rise in mean arterial blood pressure. From these results it has been postulated that beta adrenergic stimulation contributes to the plasma volume loss and the slight fall in mean arterial pressure observed following thermal trauma.


[Extravesical ureteral ectopy: report of 2 cases]. Two cases are presented in different sexes of an extravesical, ureteral ectopia, one of which was associated with a cryptorchid U.V.R. and micropenis and the other with complete, bilateral duplicity of the tracts. The authors comment upon the clinical peculiarities in both sexes, as well as the surgical possibilities in each case, with special emphasis on the etiopathogenic and diagnostic problems involved in this type of malformation.


[Echocardiographic diagnosis of obstructive myocardiopathies: study of the systolic anterior motion of the mitral valve and septal hypertrophy as compared with the hemodynamic and mechanographic findings. Evolution under medical treatment]. Characteristic echocardiographic features of hypertrophic obstructive cardiomyopathy were recorded in 24 patients, all of whom had asymmetric septal hypertrophy and systolic anterior motion of the mitral valve (SAM) at rest or after pharmacodynamic stimulation. The relationship between outflow tract obstruction and SAM was assessed by comparison with data obtained at cardiac catheterisation and external mechanography: SAM seems to be a non-specific phenomenon and may be recorded in cases of hypertrophic cardiomyopathy without obstruction during pharmacodynamic stimulation. In forms with obstruction, SAM and the severity of obstruction increase with the degree of spetal hypertrophy. The increased contractility of the left ventricular posterior wall appears to be an important factor in the mechanism of SAM which can be prevented by betablockade in moderate or labile forms. When SAM is permanent, whatever the gradient recorded, it is a sign of anatomical deformation of the left ventricle and may be an additional indication for cardiac surgery.


[Continuous ambulatory electrocardiographic recordings using the Holter system in the late phase of hospitalization for recent myocardial infarct. Value and limitations studied in a series of 100 patients]. Repeated continuous ambulatory electrocardiography by Holter monitoring was performed after early mobilisation post-myocardial infarction in 100 patients, without ventricular extrasystoles on classical ECG. Frequent ventricular arrhythmias were recorded in 58 p. 100 cases, unrelated to the localisation of the infarct. The observation of ventricular arrhythmias in the Coronary Care Unit (CCU) was not related to the occurrence of VEs during Holter monitoring. On the other hand, VEs were less frequent (38 p. 100 compared to 68 p. 100) in patients taking amiodarone or betablockers on transfer from the CCU. The reduced activity of patients during Holter monitoring minimises the frequency of arrhythmias, and 10 p. 100 patients were observed to have VEs only after exercise tolerance testing. These VEs seem to be a bad prognostic factor; the 9 patients who died in this series all presented VEs on ambulatory monitoring (7) or during exercise tolerance testing (2). However the number of patients with triple vessel disease was greater in the group with VEs on ambulatory monitoring (57 p. 100 compared with 13 p. 100). It is difficult to assess the precise role of the VEs amongst the other risk factors of sudden death. This is not a randomised study, but it would appear that long=term amiodarone or betablockers therapy may influence the medium-term prognosis.


Predicting drug-free improvement in schizophrenic psychosis. In a sample of 22 psychotic schizophrenic patients, eight improved substantially during a 30-day drug-free period. The drug-free improver group differed from the nonimprover group in demonstrating a later age of onset, briefer psychotic episodes, shorter hospitalizations, and better prognostic scores on the Phillips Scale, Strauss-Carpenter Modified Prognostic Scale, and the Vaillant Scale. After drug withdrawal, drug-free improvers frequently demonstrated further improvement when treated with doses of neuroleptic drugs that were substantially lower than the clinically recommended doses. The authors raise the question as to whether the drug-free improvers may represent a subgroup of schizophrenic patients who are being overtreated presently by standard neuroleptic practice.


Modifications of erythrocyte phosphofructokinase in children with acute lymphoblastic leukemia. Acute stage and remission. Erythrocyte phosphofructokinase from children with acute lymphoblastic leukemia was purified and characterized. In the acute stage of the disease the enzyme showed decrease affinity for substrate, reduced stability to heating and PCMB treatment, altered pH curve and increased effect of ATP as allosteric inhibitor. Only in one patient in remission, reversal of all enzyme abnormalities was found. In other cases, the general pattern of enzyme modifications was retained in spite of complete regression of clinical and hematologic symptoms. The only feature showing tendency to normalization in nearly all patients was the thermostability of phosphofructokinase. The results are discussed with regard to the mechanism of the enzyme's modification.


Uptake and release of putative neurotransmitters. Measurements in regions of the normal and Newcastle disease virus-infected mouse brain. The capacity of various regions of the mouse brain to accumulate a series of putative neurotransmitter compounds has been studied in cerebral homogenates. This uptake is selective, sodium dependent, energy dependent, and exhibits characteristics of high affinity transport. Calcium-stimulated release under depolarizing conditions of accumulated radioactive compounds was also examined. Large regional variations of uptake and release capacity existed. No clear relation between intensity of uptake and releasability of transported compounds was seen. The effect of infection of mice with Newcastle disease virus on these processes was investigated. No significant differences were seen in infected mice despite their depressed metabolic rate.


An improved fluorimetric determination of alpha-mannosidase activity in bovine plasma. This paper describes a manual fluorimetric method for the assay of acidic alpha-mannosidase activity in bovine plasma. The optimum conditions for the assay of this enzyme were studied. The assay method devised includes the addition of zinc to the substrate, which stimulates activity by approximately twofold, and reduces the optimum substrate concentration. This latter feature affords considerable cost saving in each test. We have also shown that the alpha-mannosidase activity in lithium heparin plasma, EDTA plasma and blood serum is the same whether the plasma/serum is separated from the cells/clot at 6, 20 or 25 hours after sample collection. This has eliminated the previous necessity of having to deliver whole blood samples to the laboratory within 6 hours of collection. Furthermore samples for the supplementary neutrophil assay can now be taken at the same time as those for the plasma test, and both samples forwarded together. The plasma alpha-mannosidase assay is a rapid and reliable screening test for the mannosidosis genotype and for detecting carrier animals. Carrying out this plasma assay in conjunction with the more definitive neutrophil assay provides a reliable method of distinguishing homozygotes and heterozygotes from normal animals.


Hydrolysis of p-NN'-phenylenebismaleimide and its adducts with cysteine. Implications for cross-linking of proteins. To understand the extent of the cross-linking of proteins by the bifunctional reagent p-NN'-phenylenebismaleimide, a quantitative study of competing reactions has been undertaken. The two reactive maleimide rings of the bismaleimide are hydrolysed in mildly alkaline aqueous solutions much more rapidly than is the single maleimide ring of the monofunctional analogue N-ethylmaleimide. The kinetics of hydrolysis are second-order, depending on both imide and hydroxyl ion concentration in the pH range 8-10. The hydrolysis of the first imide ring of the bismaleimide is more rapid than the second, with second-order rate constants of 1600 M-1 . s-1 and 500 M-1 . s-1 respectively, at 25 degrees C. The half-times for hydrolysis of the first and second imide rings at pH 9.0 are therefore only 43s and 140s. Because it renders the maleimide ring unreactive towards cysteine, this rapid hydrolysis can limit the extent of cross-linking of proteins by the bismaleimide.


The catalytic activity of pig pepsin C towards small synthetic substrates. A series of small peptides has been synthesized and used to investigate the activity of a minor pig pepsin, pepsin C (EC 3.4.23.3). The peptides had the general formula A-Leu-Val-His-B. B was either OMe, NH2 or OH. With B = NH2 hydrolysis (kcat./Km) at 37 degrees C and pH 2.07 increased as A was Ac-Ala, Ac-Tyr, Ac-Phe and Ac-Ala-Phe. The pH dependence of the hydrolysis of Ac-Phe-Leu-Val-His-NH2 indicated the apparent pKa values of two catalytically important groups on the enzyme as 1.42 and 4.88. Inhibition of the hydrolysis of the same peptide by Ac-Phe at pH 3.01 showed a form of mixed non-competitive inhibition. Hydrolysis of Ac-Tyr-Leu-Val-His-OMe and the corresponding amide showed non-classical kinetics, which are discussed in terms of a substrate-activating mechanism. The results are discussed with reference to observations made by other workers on pig pepsin A.


The inhibition of staphylococcal beta-lactamase by clavulanic acid. Clavulanic acid inhibited both the extracellular and cell-extract beta-lactamases of the four Staphylococcus aureus strains tested. The inhibition of S. aureus Russell cell-extract enzyme appeared to be active-site-directed and proceeded in a first-order fashion consistent with the formation of a covalent intermediate. Inhibited enzyme free of excess clavulanic acid was shown to regenerate enzyme activity slowly at pH 7.0, but the rate of reactivation increased at acid pH. When the enzyme was incubated with excess clavulanic acid complete inhibition was rapidly obtained, during further incubation clavulanic acid was shown to disappear slowly and complete loss of clavulanic acid from the reaction mixture coincided with the onset of the return of enzyme activity. A reactive enamine resulting from enzymic hydrolysis of the beta-lactam ring of clavulanic acid has been proposed as a possible intermediate in the inhibitory mechanism.


Kinetics of enzymic reductive deiodination of iodothyronines. Effect of pH. 5'-Deiodination of thyroxine (yielding 3,3',5-tri-iodothyronine; reaction I) and of 3,3',5'-tri-iodothyronine (yielding 3,3'-di-iodothyronine; reaction II) and 5-deiodination of thyroxine (yielding 3,3',5'-tri-iodothyronine; reaction III) and of 3,3',5-tri-iodothyronine (yielding 3,3'-di-iodothyronine; reaction IV) as catalysed by rat liver microsomal fraction were studied at pH 6.5, 7.2 and 8.0 It was found that: (1) the Km of reaction I was relatively independent of pH (approx. 3 microM), whereas V was highest at pH 6.5 (63 pmol of 3,3',5-tri-iodothyronine/min per mg of protein); (2) the Km of reaction II was lowest at pH 6.5 (0.035 microM), but V was highest at pH 8.0 (829 pmol of 3,3'-di-iodothyronine/min per mg of protein); (3) thyroxine inhibited reaction II competitively; Ki values were identical at pH 6.5 and 8.0 (1 microM); (4) for both reactions III and IV Km was lowest and V was highest at pH 8.0. The results are compatible with the view that reactions I and II are mediated by a single enzyme (iodothyronine 5'-deiodinase) and that reactions III and IV are catalysed by a second enzyme (iodothyronine 5-deiodinase).


The beta-glucosidase from Botryodiplodia theobromae. Mechanism of enzyme-catalysed reactions. The effects of pH and temperature on Michaelis constant (Km) and maximum velocity (Vmax.) and of NaCl on the activity of the high-molecular-weight beta-glucosidase (beta-D-glucoside glucohydrolase EC 3.2.1.21) from cultures of Botryodiplodia theobromae Pat. have been studied. 2. Donor binding and inhibition of activity by glucose were dependent on the ionization of a group (pK 6.0) that appeared to be an imidazole group. 3. Catalytic activity and the stimulation of activity by glycerol were dependent on the ionization of two groups, which appeared to be a carboxy group and an imidazole group. 4. The Arrhenius activation energy (Ea) calculated from results obtained at pH 4.0 and 5.0 was about 45--46kJ.mol-1. 5. The enthalpies (delta H0) calculated from results obtained at pH 4.0 and 5.0 were similar (about -4kJ.mol-1), whereas at pH 6.5 the value was about -33kJ.mol-1. 6. The entropies (delta S0) calculated from these results at 37 degrees C were -21, -22 and -118J.K-1.mol-1 at pH 4.0, 5.0 and 6.5 respectively. A low concentration of NaCl (16.6 mM) stimulated enzymic activity and decreased the Km for the donor, whereas high concentrations (up to 500 mM) inhibited enzymic activity, increased the Km and had no effect on Vmax. 8. Plots of initial velocity data obtained in the presence of dioxan as 1/v against the ratio of the molar concentration of dioxan to that of water were linear. 9. The results are discussed in terms of the enzyme mechanism.


Factors affecting the activity and stability of the palmitoyl-coenzyme A hydrolase of rat brain. Palmitoyl-CoA hydrolase (EC 3.1.2.2) catalyses the irreversible hydrolysis of long-chain acyl-CoA thioesters. This enzyme is found primarily in the postmicrosomal supernatant fraction prepared from homogenates of rat brain. Either of two forms of the hydrolase, a lower-molecular-weight species of approx. 70000 or a higher-molecular-weight species of approx. 130000 can be isolated by gel filtration. The higher-molecular-weight form is obtained from columns of Sephadex G-200 eluted with buffer containing 10mum-palmitoyl-CoA or 20% (v/v) glycerol, whereas the lower-molecular-weight form is obtained when the eluting buffer does not contain palmitoyl-CoA or glycerol. The two forms of the hydrolase have the same pH optimum of 7.5, are equally sensitive to the thiol-blocking reagents p-hydroxymercuribenzoate, HgCl(2), and 5,5'-dithiobis-(2-nitrobenzoic acid), and exhibit the same K(m) (1.8mum) with palmitoyl-CoA as substrate. The two forms differ in the availability or reactivity of certain external thiol groups, as determined by covalent chromatography with activated thiol Sepharose. Dilute solutions of the lower-molecular-weight form of the hydrolase rapidly lose activity (50% in 60min at 0 degrees C), but there is no change in the K(m) with palmitoyl-CoA as substrate during this progressive inactivation. Dilutions of the hydrolase in buffer containing 10mum-palmitoyl-CoA retain full activity. However, addition of palmitoyl-CoA to solutions of the lower-molecular-weight form will not restore previously lost hydrolase activity. The evidence supports the conclusion that the substrate palmitoyl-CoA promotes the formation of a relatively stable dimer from two unstable subunits. This process may not be reversible, since the removal of palmitoyl-CoA or glycerol from solutions of the higher-molecular-weight form does not result in the appearance of the lower-molecular-weight form of the hydrolase.


Enzyme-substrate and enzyme-inhibitor complexes of triose phosphate isomerase studied by 31P nuclear magnetic resonance. The complex formed between the enzyme triose phosphate isomerase (EC 5.3.1.1.), from rabbit and chicken muscle, and its substrate dihydroxyacetone phosphate was studied by 31P n.m.r. Two other enzyme-ligant complexes examined were those formed by glycerol 3-phosphate (a substrate analogue) and by 2-phosphoglycollate (potential transition-state analogue). Separate resonances were observed in the 31P n.m.r. spectrum for free and bound 2-phosphoglycollate, and this sets an upper limit to the rate constant for dissociation of the enzyme-inhibitor complex; the linewidth of the resonance assigned to the bound inhibitor provided further kinetic information. The position of this resonance did not vary with pH but remained close to that of the fully ionized form of the free 2-phosphoglycollate. It is the fully ionized form of this ligand that binds to the enzyme. The proton uptake that accompanies binding shows protonation of a group on the enzyme. On the basis of chemical and crystallographic information [Hartman (1971) Biochemistry 10, 146--154; Miller & Waley (1971) Biochem. J. 123, 163--170; De la Mare, Coulson, Knowles, Priddle & Offord )1972) Biochem. J. 129, 321--331; Phillips, Rivers, Sternberg, Thornton & Wilson (1977) Biochem. Soc. Trans. 5, 642--647] this group is believed to be glutamate-165. On the other hand, the position of the resonance of D-glycerol 3 phosphate (sn-glycerol 1-phosphate) in the enzyme-ligand complex changes with pH, and both monoanion and dianon of the ligand bind, although dianion binds better. The substrate, dihydroxyacetone phosphate, behaves essentially like glycerol 3-phosphate. The experiments with dihydroxy-acetone phosphate and triose phosphate isomerase have to be carried out at 1 degree C because at 37 degrees C there is conversion into methyl glyoxal and orthophosphate. The mechanismof the enzymic reaction and the reasons for rate-enhancement are considered, and aspects of the pH-dependence are discussed in an Appendix.


Spectrophotometric studies on the interaction between triose phosphate isomerase and inhibitors. The binding of ligands to chicken muscle triose phosphate isomerase was studied. Changes in u.v. absorbance of the enzyme were used to measure binding, and the dissociation constant was determined over a range of pH values. The ligands were 2-phosphoglycollate and rac-glycerol 3-phosphate (only the D-isomer, sn-glycerol 1-phosphate, binds appreciably). Non-linear regression was used to fit calculated curves to the experimental points and hence to compare different models. Both active sites in the dimeric enzyme probably bound 2-phosphoglycollate, without any interaction between the sites. The results of crystallographic analysis [phillips, Rivers, Sternberg, Thornton & Wilson (1977) Biochem. Soc Trans. 5, 642--647], and experiments on the 1H, 13C and 31P n.m.r. of enzyme or 2-phosphoglycollate were combined with the present results to provide the basis for a model in which binding depends on glutamic acid-165 being protonated and on the ligant being fully ionized; additionally, binding affects the ionization of one histidine residue (probably histidine-100). The binding of the glycerol 3-phosphate, on the other hand, was independent of pH over the range pH 6.5--8.5 but decreased at lower pH values. This is explained on a model in which the binding of the monoanion of the ligand is markedly affected by the protonation of a residue in the enzyme, but the binding of the dianion is only slightly affected by this ionization.


Self-association of unconjugated bilirubin-IX alpha in aqueous solution at pH 10.0 and physical-chemical interactions with bile salt monomers and micelles. Spectrophotometric measurements of bilirubin-IX alpha in water and in aqueous/organic solvent mixtures at pH 10.0 as a function of bilirubin-IX alpha concentration (approx. 0.6--400 microM) are consistent with the formation of dimers (KD - 1.5 microM) in dilute (less than 10 microM) aqueous solution and further self-aggregation to multimers at higher concentrations. Added urea (to 10M) and increases in temperature (to 62 degrees C) obliterate the dimer-multimer transition at 10 microM, but added NaCl (to 0.30 M) promotes strong aggregation of dimers over a narrow concentration range, suggesting a 'micellization' phenomenon. Concentrations of dioxan or ethanol greater than 60% (v/v) in water were required to obtain the absorption spectrum of bilirubin-IX alpha monomers, suggesting that both hydrophobic and electrostatic (pi-orbital) interactions are involved in stabilizing the dimeric state in water. Micellar concentrations of sodium dodecyl sulphate induced spectrophotometric shifts in the dimer absorption spectrum of bilirubin-IX alpha consistent with progressive partitioning of bilirubin-IX alpha monomers into a relatively non-polar region of the micelles and allowed a deduction of the apparent critical micellar concentration that closely approximated the literature values. The pattern of bilirubin IX alpha association with bile salts is complex, since the absorption spectrum shifts hypsochromically below and bathochromically above the critical micellar concentration of the bile salts. Consistent with these observations, bilirubin IX alpha appears to bind to the polar face of bile salt monomers and to the polar perimeter of small bile salt micelles. At higher bile salt concentrations some-bilirubin-IX alpha monomers partition into the hydrophobic interior of the bile salt micelles. Our results suggest that under physiological conditions the natural conjugates of bilirubin-IX alpha may exhibit similar physical chemical properties in bile, in that dimers, highly aggregated multimers and bile salt-associated monomers may co-exist.


A thiol-labelling reagent and reactivity probe containing electrophilic mercury and a chromophoric leaving group. 2-(2'-Pyridylmercapto)mercuri-4-nitrophenol was synthesized and evaluated as a thiol-labelling reagent containing a chromophoric leaving group and as a reactivity probe by studies on its reactions with 2-mercaptoethanol and with papain (EC 3.4.22.2).


[Circadian rhythms in monocellular organisms (author's transl)]. Monocellular organisms are well suited for studies on the molecular mechanisms of circadian rhythms. Thythms in different monocellular organisms are similar. This mean that it might be anticipated that the mechanisms of all these rhythms are similar. Evidence so far available has resulted in several models, some of which emphasize the role of membranes and deserve special interest. A "coupled translation membrane model" is in full agreement with those particular results which have been obtained on the green alga, Acetabularia. Attempts to verify the role of essential polypeptides which was postulated in the model, by isolating such components appear to be successful.


[Follow-up treatment of schizophrenic psychoses: advantages and disadvantages of long-term medication]. In completely remitted schizophrenic patients with formerly paranoid-hallucinatory symptoms, the reoccurrence of relapses can be reduced in an extremely high percentage by relatively low neuroleptic long-term treatment specifically adjusted to each patient. Without medication there is an extremely high rate of relapses to be expected. In prophylactic neuroleptic medication the dose must be calculated individually. The depressive syndrome, which can be observed in higher therapeutic dosages, will then be less frequent. The social handicap due to side-effects of prophylactic treatment is more tolerable than the risk of relapse. The follow-up records of the patients treated with long-term medication of the active drug show that, in spite of side-effects, occupational resocialisation and personal stabilisation could be established more easily than in the placebo group. By close psycho-social after-care a high percentage of relapses can be handled in out-patients.


[Course of psychopathologic and extrapyramidal motor symptoms during long-term treatment of schizophrenic patients with psycholeptic drugs (author's transl)]. 65 chronic-schizophrenic outpatients were treated with fluphenazinedecanoate for 24 months. Hallucinations and delusions remitted between week 24 and 36, formal disturbances of thinking occurred in 50% of the patients up to the 24th week, mood disorders and disorders and schizophrenic changes in personality could only gradually be controlled. In the first 3 months of treatment the incidence and intensity of rigor grew up to the critical point after 24 weeks of treatment; by the 60th week of treatment it had completely vanished. Akathisia reached its peak after the first and the 36th week and two different populations could be distinguished. 8% of the patients showed dyskinetic reactions up to the 12th week; 20% of the patients showed hyper- and dyskinesia after 72 weeks of treatment. 30 to 40% of the patients required anticholinergics between the 12th and 48th weeks; after the 84th week this medication was no longer necessary.


[Influence of clozapine on neuroleptigenic extrapyramidal motor disturbances (author's transl)]. 1. Human neuroleptogenic EPMS-disturbances are reversed by clozapine in animal experiments and in clinical use. This is consistent with the central anticholinergic efficacy of clozapine. 2. Clozapine seems to be a favourable concomitant medication when high dosage therapy of neuroleptics is applied--or at the incidence of dyskinesia.


[Norepinephrine turnover under neuroleptic treatment of schizophrenic syndromes (author's transl)]. In 45 psychotic in-patients with the paranoid-hallucinatory syndrome, the psychopathology, the extrapyramidal motor disturbances and 3-methoxy-4-hydroxy-phenylethyleneglycol (MHPG) in CSF were investigated. A 15-day treatment with haloperidol induced significant increase of MHPG in CSF; after 10 days clozapine treatment MHPG was significantly reduced. 10 days later the normal values were reached again. The investigation of MHPG in CSF under treatment with neuroleptics showed no correlation between antipsychotic activity and the turnover of central norepinephrine.


[Differentiating the action of cataleptogenic bodies (author's transl)]. Responses to several drugs called cataleptogenic as shown in the "Catalepsy Testbattery", were analyzed for their trigger mechanism. The results lead to the conclusion that the neurophysiological mechanisms of neuroleptic drugs are based on an inhibition of the processing of afferences. Therefore the term "experimental catalepsy" seems to be applicable only to these drugs. On the contrary, opioid drugs induce a state of rigidity which even can be increased by manipulating the animal. These conclusions are verified by electromyographical studies. In our opinion this syndrome should not be called "catalepsy" but "opiate stiffness".


[Central and peripheral interactions of the antiparkinson agent biperiden and the antihistaminic bamipin on the rat excited by pilocarpine]. Excitatory reactions elicited by pilocarpine HCl (50 mg/kg i.v. in 6 s) are used for demonstrating synergistic effects of the central anticholinergic drug biperiden (Akineton) and the antihistamine bamipine (Soventol). Scratching movements of the hind legs are used as parameter for central activity, salivation for peripheral and death for toxic drug effect, respectively. The results show distinct synergistic (central) activity of drug combinations concerning the inhibition of scratching movements. On the contrary, no intensified inhibition is found with the peripheal symptom salivation bamipine rather induces an attenuation of inhibitory effects seen after hig doses of biperiden. Furthermore, the enhanced toxicity of pilocarpine caused by bamipine in a defined dosage range is antagonized by biperiden in a dose related manner. The results of the animal experiments presented are paralleled with clinical experience.


[The effect of neurotropic substances on the social facilitation of chickens (author's transl)]. When 8-day old chickens are placed into an unfamiliar test cage they do not begin to peck feed until a control bird has begun to peck. They immediately cease their consumption of feed as soon as the control bird has been removed. Under the influence of various neurotropic substances a deviating response occurs, which can be understood as an inability to adjust quickly to a new situation.


[Effect of long-term treatment with neuroleptics or lithium salts on carbohydrate metabolism]. Long-term treatments with neuroleptic drugs or lithium salts are well established and, with regard to side-effects, possess a common denominator: both treatments may increase the body weight, and may influence in different, even contrary ways the carbohydrate metabolism. In this study the oral glucose tolerance test (oGTT) including the determination of immunologically measurable insulin (IMI) has been performed in 49 lithium-treated out-patients, and in 125 inpatients under neuroleptic long-term treatment. The test was repeated within six months in the lithium-group. 3 different evaluation criteria were used. Among the patients with neuroleptic treatment there were 25 to 36% with a pathological glucose tolerance curve; the expected frequency would have been approx. 8%. 55% of the patients had overweight, which positively correlated to the occurrence of pathological glucose tolerance. 24.5 to 30.6% of cases with pathological oGT were found in the lithium-group. 69% of the patients had overweight; age and overweight positively correlated with pathological oGT. According to the very conservative criterion of the European Study Group (EDESG), the still increased frequency of pathological oGT curves in the second investigation, compared to epidemiological data, just failed statistical significance. The results suggest that also under long-term lithium treatment an increased lability of carbohydrate metabolism, be it due to the drug or the manic-depressive disease, must be discussed as a potential risk for the patient.


Stereochemistry of viminol, a novel central analgesic. The synthesis of the stereoisomers of the centrally acting analgesic 1-[1-(2-chlorobenzyl)-pyrrol-2-yl]-2-di-sec.-butylamino-ethanol (viminol) is described. Their absolute configuration has been shown by comparing the circular dichroism (CD) curves with those of some phenyl analogs: for one of the viminol stereoisomers the postulated configurational assignment has been recently confirmed by an X-ray analysis. The pharmacological properties shared by the viminol stereoisomers are also described. The R,R configuration of the sec.-butyl groups and the S configuration of the hydroxy group appear to be essential for the agonistic effects: analgesia, tolerance and physical dependence in rodents. The S,R,R configurated viminol does not substitute, however, for morphine in monkeys, using the single dose suppression test. S,S or R,S(S,R) configurations of the sec.-butyl groups are associated with antagonistic properties. The binding capacity of the viminol stereoisomers to the opiate receptors and their influence on the acetylcholine release from the intestinal cholinergic terminals electrically stimulated are also described.


[Blood level courses after i.v., i.m. and p.o. administration of theophylline ethylendiamine and pH-neutral solution of theophylline (author's transl)]. Serum theophylline concentration was measured in nine patients with chronic-obstructive lung disease following oral, i.m. and i.v. application. Two different preparations were tested: A pH-neutral solution of theophylline (Solosin) and theophylline-ethylenediamine. 208 mg of the pH-neutral solution of theophylline showed very similar serum concentrations as did 240 mg i.v. or p.o., but definitely higher than in the case of 360 mg i.m. theophylline ethylenediamine. After 10 min following the oral or the intramuscular application, serum concentrations were high enough for strong bronchodilating action. The oral dosages only reached the lower limit of optimal concentration for the best bronchodilation. There is a decrease of the blood concentrations by 50% after about 5 h. The bronchodilating effect subsided 2-4 h after i.v. injection.


The effect of beta-adrenergic receptor blocking drugs on cerebral blood flow. 1 Cerebral blood flow (CBF) was measured by the 133xenon inhalation method in 33 newly-diagnosed hypertensive patients prior to commencing therapy. 2 Blood pressure was treated by using a varying sequence of four different drugs, namely labetalol, metoprolol, oxprenolol and sotalol, each of which is a beta-adrenergic receptor blocking agent, but with differing additional properties. 3 CBF measurements were repeated when blood pressure was controlled. No significant change in CBF was found with any of the four drugs, in contrast to the fall which has been reported when drugs of this type are administered acutely.


The gastrointestinal absorption of PRD-92 Ea, a new anti-allergy drug. 1 The absorption of PRD-92 Ea, a new anti-allergy drug, was studied in volunteer subjects. 2 The 14C-labelled drug was administered orally and the radioactivity measured in plasma, urine and faeces. 3 Mean peak plasma concentration was 3.3 micrograms/ml, with a concentration of over 1 micrograms/ml maintained 4 h after administration. 4 The mean plasma half-life (T 1/2) was 114 min. 5 The mean percentage recovery in the urine was 9.5%. 6 Oral administration leads to significant and sustained plasma concentrations, and the oral route should be suitable for drug evaluation in clinical practice.


Hydrocortisone increases the responsiveness of mast cells to beta-adrenergic agonists by an action distal to the beta-adrenoreceptors. Hydrocortisone in pharmacologically attainable concentrations potentiates beta-adrenergic-stimulated cyclic AMP accumulation in rat peritoneal mast cells. Direct binding studies using 3H-dihydroalprenolol indicated no significant changes in the number of beta-adrenoreceptors or in the kinetics of the interaction of the radio-ligand with receptors after treatment of mast cells with the corticosteroid. Competition binding studies with epinephrine revealed no hydrocortisone-induced change in Kd values for this agonist. It is concluded that hydrocortisone-induced stimulation of cyclic AMP synthesis results from an effect that occurs beyond the interaction of the beta-adrenergic agonist with its receptor.


Elevation of pyrimidine enzyme activities in the RBC of patients with congenital hypoplastic anaemia and their parents. The activities of orotate phosphoribosyl transferase (OPRT) and orotidine monophosphate decarboxylase (ODC) were significantly elevated (P less than 0.001) in erythrocytes (RBC) from five patients with prednisone-responsive congenital hypoplastic anaemia (CHA). (OPRT: patients - 10.1--64.2 nmol/h/10(9) RBC; controls - 2.8 +/- 0.3 (mean +/- SEM, n = 37); ODC: patients = 30--124 nmol/h/10(9) RBC; controls = 10.2 +/- 0.7 (mean SEM, n = 37).) Two patients had a less pronounced, but significant, increase of aspartate transcarbamylase activity and three patients had marginal increases of dihydroorotase activity. Dihydroorotate dehydrogenase activity was not detected in any CHA patient or control. In one patient prior to prednisone therapy, the OPRT and ODT activities were elevated 10-fold and remained elevated 3-fold after 16 months of therapy. An elevated enzyme pattern similar to that of RBC from CHA patients was observed in three parents of three CHA patients, but not in three parents of two other CHA patients. The activities of all five pyrimidine enzymes were normal for one patient with transient erythroblastopenia of childhood. In contrast, the activities of all the pyrimidine biosynthetic enzymes were elevated in blood from patients with a young RBC population: sickle cell anaemia, sickle-beta-thalassaemia, hereditary spherocytosis, and DiGuglielmo syndrome and from the newborn. It is postulated that factors which affect the activities of pyrimidine enzymes in CHA may also result in diminished erythropoiesis.


The low ionic strength reaction of human blood: relationship between the binding of serum immunoglobulin and complement of red blood cells and surface charge of the cells. Using the sucrose haemolysis reaction of Hartmann & Jenkins (1966) as a basic model, the low ionic strength reaction (LISR) of human blood was studied to determine: (1) serum Ig uptake by RBC with saline elution and 125I-IgG uptake, and (2) complement fixation (CF) to RBC with lysis of PNH cells and C3H/C4 antiglobulin haemagglutination (AH) of normal cells. The saline eluates were found to contain IgG and IgM with traces of IgA; their pH optima for the uptake by RBC were 6.0 +/- 0.5, 5.5 +/- 0.5 and c 5.0 respectively. The ratio of bound IgG to IgM was linearly related to the uptake pH. Both C4 AH and lysis were found to be optimum at pH 6.0--7.5, whereas the maximum C3 AH was at pH 6.0 +/- 0.5. The LISR performed at a constant pH (6.1 +/- 0.1) showed that an increasing concentration of neuraminidase (VCN) used in pretreatment of RBC was associated with a decrease in both IgG uptake and CF activity. A maximum VCN effect reduced the Ig uptake to c 20% of normal and abolished almost all the CF activity. An impaired LISR to various degrees was also observed with RBC pretreated with ficin, papain, bromelin, trypsin or protamine, and RBC from two individuals of En(a-) type. Preincubation of serum at LIS with and without RBC resulted in respectively a 'complete' and partial consumption of C in the fluid phase. The latter was not enhanced or inhibited by the addition of VCN-treated RBC for preincubation. A hypothesis is proposed suggesting that in the LSR the Ig uptake by RBC is an electrostatic interaction of the oppositely charged RBC and Ig and the CF to RBC results from C activation by the cell-bound IgG and IgM. In addition, a pH-dependent inactivation of the cell-bound C3 in the LISR is demonstrated.


Neoprontosil binding to carbonic anhydrase. Reasonance Raman and other studies on the ionization behavior of the sulfonamide. Alkalimetric, spectrophotometric, NMR, and resonance Raman titrations are reported for the sulfonamide Neoprontosil in aqueous solution. An assignment of the magnetic resonance peaks for each of the Neoprontosil protons has been made. Neoprontosil is shown to have two "coupled" iity of the microscopic pKs for these two groups precludes spectroscopic characterization of the separate -SO2NH2, -O- or -SO2NH-, -OH species. For this reason, no conclusion can be drawn on the ionization state of the drug when bound to carbonic anhydrase. The resonance Raman spectrum of Neoprontosil bound to human carbonic anhydrase B at pH 9.5 shows a shift in the intense -N=N- stretching mode from 1414 (free) to 1407 cm- (bound), suggesting that a slight conformational change about the -N=N- single bond linkages occurs upon binding.


trans-alpha, beta-Diformamido-beta-(5'-phosphoribosylamino)acrylamide: a possible new intermediate in de novo purine biosynthesis. The nucleotide trans-alpha, beta-diformamido-beta-(5'-phosphoribosylamino)acrylamide (DAR) has been chemically synthesized and is converted to inosine 5'-phosphate (IMP) by enzyme activities found in chicken, rat, and human liver. The increase in optical density at 250 nm when DAR is converted to IMP is used as the basis of the assay. The Km values for DAR at pH 7.4 were 2.8 and 4.2 microM with the chicken and rat liver enzymes, respectively. The integrated Michaelis--Menten equation was used to determine the kinetic parameters of the chicken liver enzyme from pH 5.6 to 10.1. The pH--activity profiles show ionizations with pKa values of 6.1, 7.1, and 8.8. The possibilities that DAR is a substrate analogue or a new intermediate in the pathway of purine biosynthesis de novo are discussed.


Inhibition of lactate transport and glycolysis in Ehrlich ascites tumor cells by bioflavonoids. Bioflavonoids are potent inhibitors of lactate transport in Ehrlich ascites tumor cells. The most effective bioflavonoids have four to five hydroxyl groups. Sugar substitution at carbon three, or reduction of the double bond between carbons two and three, decreases their inhibitory activity. Quercetin, the most extensively studied of these compounds, inhibits lactate efflux by 50% at 0.1 micrograms/mg of protein. On addition of quercetin to glycolyzing Ehrlich ascites tumor cells, lactate accumulates inside the cell and the intracellular pH drops. Total lactate production is also inhibited. Nigericin prevents the internal acidification that occurs in the presence of quercetin and also reduces the inhibition of glycolysis. Thus, it appears that inhibition of lactate efflux can affect glycolysis through a lowering of the intracellular pH. The inhibitory effect of quercetin on glycolysis can be explained by its effect on lactate efflux and its previously reported effect on the Na+--K+ ATPase [Suolinna, E.--M., et al. (1974) J. Natl. Cancer Inst. 53, 1515].


Investigation of the interactions of oxytocin with neurophysins at low pH using carbon-13 nuclear magnetic resonance and carbon-13-labeled hormones. The specifically 13C-labeled (90% 13C-enriched) peptide hormone derivatives [1-hem[2-13C]cystine]oxytocin, [1-hemi[1-13C]cystine]oxytocin, and [2-[-2-13C]tyrosine[-oxytocin and the analogue [3-[2-13C]leucine]oxytocin were prepared by total synthesis and used to study the interactions of the neurohypophyseal hormones with the bovine neurophysins as a function of pH and temperature. Under all conditions, whether high or low pH, the chemical shifts of the labeled carbon atoms of the bound hormones are the same, but they are shifted significantly from their positions in the free hormone. These results indicate that interactions of the side chain and disulfide moieties of the hormone with the neurophysins do not change as a function of pH. At neutral pH and 20--35 degrees C, the labeled atoms of the hormone are in slow exchange (1--5 s-1) with the neurophysins for the above hormone derivatives, but at low pH they are in intermediate or fast exchange depending upon the pH and temperature. At low pH, the dissociation rate constant (koff) is about 100-fold greater than the value at neutral pH, and this increase appears to be due exclusively to the breaking of the salt bridge involving the N-terminal amino group of oxytocin and a side-chain carboxyl group of neurophysin. Since the dissociation constant (Kd) also increases by about 100-fold in going from neutral to low pH, the association rate constant is deduced to be the same at neutral and low pH. In contrast to the low pH results, an increase in pH (from 6.6 to 10.5) leads to a continual decrease in the binding constant but to no apparent change in the dissociation rate constant. The bound hormone is always in slow exchange at high pH, even when the binding constant has been reduced by 2 or 3 orders of magnitude. At high pH, the decrease in binding affinity is due solely to the deprotonation of the alpha-amino group of the free hormone. Thus, at high pH the apparent association rate constant decreases, while the dissociation rate constant remains unchanged.


Analysis of the molecular species of the chick oviduct progesterone receptor using isoelectric focusing. Conditions are described for the preparative isoelectric focusing in flat beds of Sephadex of the progesterone receptor from the chick oviduct. The method allows the fractionation of the receptor into two molecular species, one focusing at pI 6 and the other at pI 7 with good purification and recovery. The pI 6 and pI 7 receptor species were purified 2- and 26-fold, respectively. The assaying of the focused fractions with the charcoal binding method provides an accurate identification and quantitation of the [3H]progesterone receptor. The method is reproducible in recovery, quantitation, and resolution of the two receptor species. The receptor with an apparent pI of 6 sediments at approximately 4 S on linear sucrose gradients, while the receptor with an apparent pI of 7 sediments at approximately 3.5 S. On the basis of the sedimentation values and elution patterns from diethylaminoethyl (DEAE) chromatography, the pI 6 component is equivalent to the "B" receptor species and the pI 7 component is equivalent to the "A" receptor species described previously [schrader, W, T., 7 O'Malley, B. W. )1972) J. Biol. Chem. 241, 51--59].


Comparison of the kinetic specificity of subtilisin and thiolsubtilisin toward n-alkyl p-nitrophenyl esters. The p-nitrophenyl esters of straight-chain fatty acids were used as substrates of the enzyme subtilisin Novo (EC 3.4.4.16) and its chemically produced artificial enzyme thiolsubtilisin. Subtilisin and thiolsubtilisin pH--activity profiles were determined, and kinetic effects of the active site O-S substitution were observed. Among the substrates tested, both enzymes show highest specificity with p-nitrophenyl butyrate. It was also found that subtilisin is more sensitive to changes in substrate chain length than is thiolsubtilisin. Second-order acylation rate constants (k2/Ks) are remarkably similar for both enzymes. However, thiolsubtilisin deacylation rate constants and Km values are lower than analogous subtilisin constants. While thiolsubtilisin deacylation rate constants give a pH profile identical with that of subtilisin, the pH profile of thiolsubtilisin acylation rate constants shows an active site pK value lowered from the subtilisin pK of 7.15 and exhibits an inflection point at pH 8.45, which is absent in subtilisin.


Membrane damage by a toxin from the sea anemone Stoichactis helianthus. I. Formation of transmembrane channels in lipid bilayers. The addition of nanomolar amounts of a toxin preparation derived from the sea anemone Stoichactis helianthus to black lipid membranes increases their electrical conductance by one million-fold. In addition, the membranes become permeable predominantly to monovalent cations. The elevated bilayer conductance is voltage-dependent, and the current-voltage curves of these bilayers display rectification as well as a region of negative resistance. The membrane activity of the toxin is proportional to the third power of its concentration, and at very low concentrations the membrane conductance increases in discrete uniform steps. These observations indicate that the mechanism of toxin action involves the formation of transmembrane channels constructed by the aggregation of protein molecules which are inserted in the bilayer. The voltage-dependent membrane conductance arises from two distinct channel characteristics: (1) the unit conductance of individual channels is dependent on the polarity of applied voltage; (2) the number of ion-conducting channels is influenced by the polarity as well as the magnitude of applied potential. It is believed that these effects are due to the influence of an electric field on the insertion of toxin molecules into the bilayer or on their subsequent association with each other to produce channels. Partial chemical characterization of the toxin material has shown that the membrane active factor is a basic protein with a molecular weight of 17,500.


Membrane damage by a toxin from the sea anemone Stoichactis helianthus. II. Effect of membrane lipid composition in a liposome system. In the first paper of this series, it was shown that a toxin from the sea anemone Stoichactis helianthus increased the permeability of black lipid membranes due to transmembrane channel formation. In the present study, we have used liposomes to examine the reactivity of the toxin with different phospholipids. Membrane damage was assessed by measuring the release of 86Rb+ and 14C-labeled membrane lipid. For the different lipids, the rank order of marker release was: sphingomyelin greater than C18 : 2 phosphatidylcholine greater than C18 : 1 phosphatidylcholine greater than C18 : 0 phosphatidylcholine greater than C16 : 0 phosphatidylcholine = C14 : 0 phosphatidylcholine. In C14 : 0 and C16 : 0 phosphatidylcholine liposomes there was no 14C-labeled lipid release and only 13 to 16% 86 Rb+ release which corresponds to the 86Rb+ content in the outermost aqueous shell of multilamellar liposomes. This indicates that membrane damage was limited to the outermost bilayer. In liposomes prepared with the other lipids, the extent of release of both markers increased proportionately with the length and the degree of unsaturation of the lipids' acyl side chains. Spingomyelin liposomes were the most susceptible with 47% of the 14C-labeled lipid marker and 90% of the 86Rb+ marker being released. The large extent of 14C-labeled lipid release is attributed to a detergent-like activity of the toxin which presumably is due to the amphipathic nature of the protein. Thus, the toxin can inflict membranrtance of one mechanism or the other apparently varies depending on membrane structure and lipid composition.


Effect of membrane potential and internal pH on active sodium-potassium transport and on ATP content in high-potassium sheep erythrocytes. Ouabain-sensitive Na+ and K+ fluxes and ATP content were determined in high potassium sheep erythrocytes at different values of membrane potential and internal pH. Membrane potential was adjusted by suspending erythrocytes in media containing different concentrations of MgCl2 and sucrose. Concomitantly either the external pH was changed sufficiently to maintain a constant internal pH or the external pH was kept constant with a resultant change of internal pH. The erythrocytes were preincubated before the flux experiment started in a medium which produced increased ATP content in order to avoid substrate limitation of the pump. It was found that an increased cellular pH reduced the rates of active transport of Na+ and K+ without significantly altering the ratio of pumped Na+/K+. This reduction was not due to limitation in the supply of ATP although ATP content decreased when internal pH increased. Changes of membrane potential in the range between -10 and +60 mV at constant internal pH did not affect the rates of active transport of Na+ or K+.


Titration of sodium channel sites for hydrogen ion block and sensitized photochemical modification of lobster axons. The pH dependence for sensitized photochemical block of sodium channels in lobster giant axons was determined and compared with direct channel block by protons. Isolated axons were studied in a double sucrose gap voltage clamp arrangement and the pH of the external bath was varied over the range 4.1--11.0. Irreversible photochemical block was achieved by illumination with visible light in the presence of eosin Y or acriding orange. The rate constant for photochemical block of sodium channels was depressed at both high and low pH relative to that at neutral pH, revealing the existence of two receptors involved in the process with pK values of 4.8 and 10.4. A direct reversible channel-blocking receptor titrates with a pK of 4.8, the same as one of the receptors involved in the photochemical block, and senses about 9% of the electric field as determined by a Woodhull analysis. Lowering the pH from 8.2 to 4.6 shifted the sodium conductance versus voltage relation in the depolarizing direction. It is proposed as a hypothesis that the low and high pK receptors are histidine imidazole and primary amino groups, photooxidation of which leads to channel block via cross-linking of channel proteins.


Transport of p-aminohippuric acid, uric acid and glucose in highly purified rabbit renal brush border membranes. A procedure for preparing highly purified brush border membranes from rabbit kidney cortex using differential and density gradient centrifugation is described. Brush border membranes prepared by this procedure were substantially free of basal-lateral membranes, mitochondria, endoplasmic reticulum and nuclear material as evidenced by an enrichment factor of less than 0.3 for (Na+ + K+)-ATPase, succinate dehydrogenase, NADPH-cytochrome c reductase and DNA. Alkaline phosphatase was enriched ten fold indicating that the membranes were enriched at least 30 fold with respect to other cellular organelles. The yield of brush border membranes was 20%. Transport of D-glucose by the membranes was identical to that previously reported except that the Arrhenius plot for temperature dependence of transport was curvilinear (EA = 11.3--37.6 kcal/mol) rather than biphasic. Transport of p-aminohippuric acid and uric acid were increased by the presence of NaCl, either gradient or preequilibrated. However, no overshoot was obtained in the presence of a NaCl gradient, and KCl and LiCl also produced equivalent stimulation of transport suggesting a nonspecific ionic strength effect. Uptakes of p-aminohippuric acid and uric acid were not saturable, and were increased markedly by reducing the pH from 7.5 to 5.6. Probenecid (1 mM) reduced p-aminohippuric acid and uric acid (50 muM) uptake by 49% and 21%, respectively. We conclude that the uptake of uric acid and p-aminohippuric acid by renal brush border membranes of the rabbit occurs primarily by a simple solubility-diffusion mechanism.


Formation of delta-aminolevulinic acid from glutamic acid by a partially purified enzymes system from wheat leaves. A method for partial purification of an enzyme system from greening wheat leaves which converts 14C-labeled glutamate to delta-aminolevulinic acid is described. The purification entails the successive use of anion and cation exchange, followed by molecular sieving. The enzyme system is unstable in crude form, but the stability is markedly increased after column chromatography on CM-cellulose. The pH profile and the cofactor requirements suggest that at least two enzymes are involved.


Steady-state kinetics of plasmin- and trypsin-catalysed hydrolysis of a number of tripeptide-p-nitroanilides. The steady-state kinetics of plasmin- (EC 3.4.21.7) and trypsin-catalysed (EC 3.4.21.4) hydrolysis of Bz-L-Phe-Val-Arg-pNA, Bz-D-Phe-Val-Arg-pNA, L-Phe-Val-Arg-pNA, D-Phe-Val-Arg-pNA and D-Val-Leu-Lys-pNA were investigated in the pH range 6-9. The pH dependences of the kinetic parameters correspond with the effects of catalytically essential ionizations in the enzymes, except for reactions with L- and D-Phe-Val-Arg-pNA, in which protonation of the NH2-terminal alpha-amino groups (pK = 7.0) shows some inhibitory effect. The reactions of plasmin and trypsin with p-nitroanilides show kc values similar to those normally found with specific ester substrates, indicating that the deacylation steps of the reactions are rate determining.


Physicochemical properties of non-activated and activated renin from human amniotic fluid. The main physicochemical and enzymic properties of non-activated and activated human amniotic renin (EC 3.4.99.19) were studied in order to clarify the relationships between the two enzymes. Human amniotic renin was activated by dialysis against acidic buffer (pH 3.3), direct acidification or trypsin treatment. All procedures produced similar activation. The physicochemical characteristics of non-activated and activated renin were compared to those of human renal renin. Non-activated renin had a molecular weight of 45,500. A similar molecular weight was obtained by gel eluate activation and by acid treatment of renin prior to gel filtration. Similar isoelectric points were also found for non-activated and activated renin. One major renin peak focused at pH 6.6, whereas no similar renin peak was detected in extracts from normal human kidney. In addition, non-activated and activated renin forms were found to have the same optimal pH, the same Km and the same inhibiting pepstatin concentrations.


Affinity labeling of histidine and lysine residue in the adenosine deaminase substrate binding site. 1. Adenosine deaminase was inactivated by 9-(4-bromoacetamidobenzyl)-adenine (I) and 9-(2-bromoacetamidobenzyl)adenine (II), two affinity labels. 2. The stoichiometry of the reaction with reagent II is reported: 1 mol reagent is bound per mol inactive enzyme. Amino acid analysis of the 6 N HCl hydrolyzate of the inactive enzyme identified CM-histidine as the main alkylation product. This is the first evidence of the presence of a histidine in the active site region. 3. The alkylation rate and involved amino acid residues were studied for both reagents I and II, at pH 8 and 5.5. The particular reactivity of a lysine near or in the active site is discussed.


Characterization of a C21 neutral steroid hormone transforming enzyme, 21-dehydroxylase, in crude cell extracts of Eubacterium lentum. A strain of the obligate anaerobe, Eubacterium lentum, isolated from human feces, catalyzes the 21-dehydroxylation of 11-deoxycorticosterone to progesterone. A quantitative radiochromatographic assay was developed to measure 21-dehydroxylase activity in cell extracts. Maximum enzyme activity in cell extracts required both a reduced pyridine nucleotide and an oxidized flavin coenzyme. However, photochemically reduced flavin (FMNH2) could replace the requirement for NAD(P)H plus oxidized flavin. NAD(P)H : flavin (either FMN or FAD) oxidoreductase activity was detected spectrophotometrically in cell extracts assayed under anaerobic conditions. 21-Dehydroxylase was active from pH 5.4 to 8.5 with an apparent optimum between 6.4 and 6.8 using mixtures of NADH plus FMN as coenzymes. The substrate concentration at half-maximal reaction velocity was 8.0 microM and a specific acitivity of 5.8 nmol [3H]progesterone formed . h-1 . mg-1 protein was determined using [3th]deoxycorticosterone as substrate. Atabrine, rotenone, acriflavin, and 2,4-dinitrophenol (all at 1 mM) inhibited 21-dehydroxylase activity in cell extracts by 25, 24, 35 and 84%, respectively. These results suggest that 21-dehydrogenase may be coupled to a NAD(P)H : flavin oxidoreductase system in E. lentum.


Choline and ethanolamine glycerophospholipid synthesis in isolated synaptosomes of rat brain. Substantial activities of cholinephosphotransferase (EC 2.7.8.2) and ethanolaminephosphotransferase (EC 2.7.8.1) were found with lysed synaptosomes but not with intact synaptosomes isolated from adult rat brains. Synaptosomal and non-synaptosomal microsomal transferases were similar in kinetic properties. Substantial activities of synaptosomal transferases have not been described previously. Part of the glycerophospholipids in synaptosomal membranes may be synthesized in the nerve ending in addition to the glycerophospholipids supplied by axonal transport. The synthesis of the alkylacyl type of choline and ethanolamine glycerophospholipids was moderately inhibited by 1 mM ATP and 1 microM cyclic AMP. This synthesis was also inhibited by more than 50% by 1 mM norepinephrine and to a lesser extent by 5 mM hydroxytryptamine and 1 mM acetylcholine. Cyclic AMP may mediate the effects of biogenic amines. The relative synthesis of different glycerophospholipid classes and the relative proportion of alkylacyl type (plasmalogen precursors) and diacyl type of glycerophospholipids may be influenced by the levels of adenine nucleotides and/or biogenic amines. Elevated cyclic AMP levels will decrease the synthesis of plasmalogen precursors.


Characterization of cerebroside (monoglycosylceramide) from the sea anemone, Metridium senile. Identification of the major long-chain base as an unusual dienic base with a methyl branch at a double bond. 1. Cerebroside of the sea anemone, Metridium senile, has been isolated (0.6 mg/g dry tissue weight) and structurally characterized. 2. The structure was shown by mass spectrometry, NMR spectroscopy and degradative studies as beta-glucopyranosylceramide. The major fatty acids were 16 : 0 and 20 : 0 D-2-hydroxy fatty acids. The major base was a novel base, D-erythro-1,3-dihydroxy-2-amino-9-methyl-trans-4, trans-8-octadecadiene. 3. Some unusual fatty acids of marine origin are suggested to originate in this long-chain base by metabolic conversion. 4. The implication of the methyl branch position of the base on our current view of sphingolipid function in the plasma membrane is discussed.


A method of estimating the amount of calcium bound to the metallochromic indicator arsenazo III. As a metallochromic indicator for ionized calcium, arsenazo III is approximately 50 times more sensitive than murexide. However, because of the high binding constant for calcium, the following problems may occur: (a) a considerable amount of calcium is bound to arsenazo III, thereby causing an error in estimating the concentration of ionized calcium; (b) the amount of bound calcium varies with the concentrations of calcium;, arsenazo III, magnesium ion and monovalent cations; (c) the amount also varies with pH, (d) the relationship between the absorbance change and the concentration of ionized calcium is nonlinear; and (e) the binding constant of arsenazo III for calcium cannot be determined by the conventional double reciprocal plot. A new experimental and theoretical method is presented which copes with these problems.


Angiotensin and bradykinin interactions with phospholipids. Reversible interactions were demonstrated between some phospholipids and some polypeptides related to angiotensin and bradykinin. The extent of the interaction was dependent on the structures  of the lipid and peptide. The naturally occurring compounds that interacted most avidly were cardiolipin and (des-Asp1)-angiotensins. The apparent dissociation constant of this complex in chloroform was 10(-5) M. The complex contained more than one cardiolipin molecule/molecule of peptide. Kinins interacted most strongly with lecithin. The phospholipids altered the chromatographic behavior of radioiodinated derivatives of the polypeptides, and solubilized radioactive and unlabeled polypeptides in chloroform. In aqueous media, cardiolipin suspensions preferentially bound (des-Asp1)-angiotensin II, and inhibited its binding by antibody. The interactions were sensitive to pH and cations in the aqueous phase, and were reversed by some reagents added to the organic phase. These interactions have direct implications for binding reactions of peptides in vitro, and may bear upon the actions of the hormones in vivo.


[Electron microscopic study of pectin solutions]. Electron microscopic study was carried out of the structure of pectin 0.01% aqueous solutions according to esterification degree at different pH medium. Preparations were prepared by freezing-drying method of solution drop on the formvar film and by the negative contrasting method. Microfibrils of 60-180 A diameter were found. Their aggregation increased with a decrease of the charge of pectin macromolecule (increase of esterification, decrease of pH).


[Photo-induced H+ transport in Nitellopsis obtusa cells]. Light-induced changes of pH in the vacuole as well as changes of the electric potential difference across the plasmalemma and the tonoplast of Nitellopsis obtusa were measured simultaneously by means of conventional and H+-specific glass or antimony microelectrodes. Illumination is found to produce a decrease in pH of the vacuolar sap by 0.1-0.5 units concomitant with cell depolarization. Cells suspended in a medium with pH 9.0 exhibit great (up to 100 mV) light-induced potential changes but only small pH changes of the vacuolar sap. When pH of the external medium (pH0 in shifted from 9.0 to more acid values the amplitude of photoinduced changes of pH in the vacuole rises up to 0,3-0.5 pH units and the amplitude of the potential changes at the plasmalemma gets smaller. At pH0 = 9.0 a transient acidification of the medium is observed upon illumination whereas at lower pH light-induced alkalinization was only seen. Transition of the cells from pH0 9.0 to pH0 7,5 results in cell hyperpolarization by 60-80 mv and a decrease of vacuolar pH by 0.4-0.5 units under light conditions but has no significant effect on the potential and the vacuolar pH in the darkness. It is proposed that mechanisms of active H+ extrusion from the cytoplasm are located both at the plasmalemma and tonoplast. Light-induced depolarization seems to be determined by the increase of H+-conductance of the plasmalemma and by a correspondent decrease in the electrogenic components of the membrane potential. The ratio of light-induced H+-fluxes across the tonoplast and the plasmalemma depends crucially on the level of H+-conductance of the plasmalemma.


Arginine vasopressin during gestation and parturition in sheep fetus. The possible correlation between plasma arginine vasopressin (AVP) concentration and the processes leading to parturition was assessed in 11 chronically catheterized pregnant ewes. Samples of blood withdrawn intermittently during a 20-day period preceding labor and during parturition were analyzed for AVP by a specific radioimmunoassay, as well as for pH, PaCO2 and PaO2. Fetal AVP was 1.74 +/- 1.55 pg/ml and maternal AVP 1.47 +/- 0.74 pg/ml (mean +/- SD). No preparturient rise in fetal vasopressin was noted, but levels increased progressively during labor to reach peak levels in cord blood (range 7.5--8,000 pg/ml). There was no consistent rise in maternal vasopressin during the same interval. A relationship between prolonged antepartum intrauterine asphyxia and increases in fetal vasopressin was noted. It is concluded that the markedly elevated levels of vasopressin observed in cord blood are the result of intrapartum 'stress', but are not related to the initiation of parturition.


[Effect of temperature on the photo-induced pH gradient in isolated chloroplasts]. Experimental data are presented on the change of photoinduced proton transport and velocity of electron transport (according to photoreduction of K3Fe(CN)6) in chloroplasts during heating within the temperature range 25-50 degrees C for 3 and 5 min. Preliminary heating of chloroplasts irreverssibly supresses the ability of chloroplasts membrane to bind the protons. The velocity of electron transport decreases with the increase of heating temperature, the value of photoinduced change of pH also decreases. Heating is suggested to affect the electron transport chain. The velocity of electron transport decreases and induces the inhibition of proton transport. Presence of detergents, such as digitonin and triton X-100 in chloroplast suspension in concentrations not higher then 0.02% supresses the process of photoinduced change of pH.


Effect of some ecological factors of degradation of propanil, linuron, and their transformation product 3,4-dichloroaniline in soil. The degradation of xenobiotics was investigated in model experiments in soddy-podzolic soil as a function of their concentration, pH moisture content, temperature, and aeration of the soil, and presence of organic and mineral compounds. The main and secondary factors determining the persistence of xenobiotics in soil were established and approximation formulas for calculating their persistance criteria (ty) were proposed.


Alterations in creatinine clearance during respiratory distress syndrome. Some renal parameters have been studied in newborns with respiratory distress syndrome (RDS). During the first 24 h, the serum creatinine level of the severe cases of RDS are significantly increased, decreasing gradually with improvement of the RDS and reaching normal values within 10 days. Blood urea nitrogen remained unchanged. In the milder cases of RDS, the serum creatinine also showed a slighter increase, which became normal within 4 days after birth. During the acute phase of RDS, there is a reversible impairment in the renal function, which correlates with the degree of hypoxia, hypercapnia and acidosis determined by the primary disease.


DNA polymerase activity of lymphocyte nuclei of cattle lymph in the normal state and in lympholeukemia. A comparative study wad made of the DNA polymerase activity of lymphocyte nuclei of cattle lymph in the normal state and in lympholeukemia. No significant differences were found in the specific DNA polymerase activity of the nuclei of normal and leukemic lymphocytes, both in the absence and in the presence of exogenous "activated" DNAs. The DNA polymerase activity of both types of nuclei was a maximum at pH 7.8 and a Mg2+ concentration of 4--6 mM. The DNA polymerase activities of lymphocyte nuclei of the lymph of healthy and leukemic animals did not differ in sensitivity to the inhibiting action of actinomycin D and in thermal stability. It was concluded that in cattle lympholeukemia, there are no significant changes in the DNA polymerase system of lymph lymphocyte nuclei.


Studies on the effect of acute asphyxia on the fetal pig in utero. 8 term fetal pigs (110-112 days gestation) and one 97-day fetus were asphyxiated in utero by occlusion of the umbilical cord. Mean times to last gasp and last heart beat were 5.1 and 22.4 for term and 5.4 and 30.4 min for the 97-day fetus. Cord occlusion was followed by profound bradycardia and an increase in blood pressure which was maintained until gasping ceased. Profound acidemia, hypercapnia and hyperlactacidemia developed in all animals and values following asphyxiation were comparable with those seen in stillborn piglets. Liver and cardiac glycogen levels were lower in asphyxiated fetuses than in littermates but muscle glycogen levels were similar in both groups.


An animal model for Huntington's disease. In review is concerned with research done on an animal model for the hereditary neuropsychiatric disorder, Huntington's disease (HD). The neuropathology of HD involves primarily a selective degeneration of neurons with cell bodies in the striatum. Injection of kainic acid, a potent neuroexcitant structurally related to glutamic acid, into the rat striatum causes a selective neuronal degeneration resembling that of HD. Striatal cholinergic and GABAergic neurons, including their terminal projections in the substantia nigra, are affected by kainate; dopaminergic axons innervating the striatum as well as corticofugal fibers passing through the region are spared. The striatal kainate lesion has aided in the characterization of the neuronal circuitry in the nigrostriatal axis including the neuronal localization of dopamine-sensitive adenylate cyclase, neuroleptic binding sites, and GABA receptors. Studies in vivo and in vitro with kainate and its analogues suggest that the potent neurotoxicity of kainate involves a cooperative interaction between synaptically released glutamate and injected kainate on vulnerable neurons; prior destruction of cortico-striatal glutamatergic afferents attenuates kainate's neurotoxicity. The kainate model has been used to test drugs that may be of therapeutic benefit for HD. A better understanding of the mechanism of neurotoxicity of kainate may shed light on the cause of neuronal degeneration in HD.


Dysphoric response to neuroleptic treatment in schizophrenia: its relationship to autonomic arousal and prognosis. Longitudinal pharmacotherapeutic data from 58 schizophrenic patients suggest that the emergence of a dysphoric state, characterized by a combination of anxiety, depression, and accusatoriness, early in the course of neuroleptic treatment augurs poor therapeutic outcome and is associated with an unfavorable prognostic classification and a tendency for autonomic arousal to increase with treatment from a drug-free base line somewhat higher than normal. These associations particularly characterized the nonparanoid schizophrenics with nuclear prognostic classification and poor short-term as well as long-term therapeutic outcome; they did not apply to the paranoids. The dysphoric response was unrelated to base-line dysphoria or to the extrapyramidal reactions to neuroleptic medication, and seemed to reflect some basic biological differences between the poor prognosis nonparanoid, the good prognosis nonparanoid, and the paranoid schizophrenics.


The tyramines: are they involved in the psychoses? On the evidence that the administration of some antipsychotic drugs and d-amphetamine, separately and in combination, induced changes in the concentration of striatal p- and m-tyramine, it is proposed that the tyramines may possess a role in neural function. This function could be as neurotransmitters in specific neuronal systems or as synaptic activators.


Cerebrospinal fluid monoamine metabolites and cyclic nucleotides in chronic schizophrenic patients with tardive dyskinesia or drug-induced tremor. Lumbar CSF HVA, MHPG, 5HIAA, cAMP, and cGMP were measured in 12 chronic schizophrenics with tardive dyskinesia before and 3 weeks after sodium valproate (VPA) or cyproheptadine treatment. HVA levels significantly decreased and cAMP and cGMP levels significantly increased during the administration of VPA or cyproheptadine. There were no significant correlations between the degree of improvement in tardive dyskinesia and the changes of amine metabolities or cyclic nucleotides. None of the pretreatment values for CSF amine metabolites or cyclic nucleotides were different from those of 15 chronic schizophrenics without tardive dyskinesia as controls. Decrease of HVA and increase of cGMP during the treatment might indicate the normalization of dopaminergic-cholinergic imbalance in the brain. Furthermore, significantly low levels of 5HIAA were observed in the patients with drug-induced tremor. It is suggested that neuroleptic-induced tremor may be attributed to serotonergic dysfunction in the brain.


Finger tremor and extrapyramidal side effects of neuroleptic drugs. Finger tremor and extrapyramidal side-effects (EPSEs) were measured in seven patients before and during neuroleptic drug treatment to assess the relationship between the onset of EPSEs and changes in finger tremor spectra. Tremor and EPSEs were also measured in twelve patients stabilized on neuroleptic drugs to determine whether tremor could provide a reliable index of the presence and severity of extrapyramidal system disturbance. A downward shift in peak tremor frequently was noted within 48 hours of starting neuroleptic drug therapy, usually before the onset of EPSEs, and a significant negative relationship between the severity of EPSEs and tremor frequency (but not tremor amplitude). The peak frequency of finger tremor is thus a sensitive index of extrapyramidal disturbance and might be of value in predicting which patients taking neuroleptic drugs need anti-parkinsonian therapy.


A comparison of three behaviour therapies in the treatment of social phobia. This study examined the effects of desensitization, flooding and social skills training on social fears. The patients were 30 social phobics. All three treatments were associated with useful therapeutic gains during the period of treatment that were maintained over a six-month follow-up period. No differences were found between treatments.


The management of indwelling catheters.

The management of indwelling catheters. Eighteen geriatric patients with indwelling catheters were observed for a total of 393 weekly urine specimens. The effects of a 1 week course of antibiotics/chemotherapeutic agent followed by urinary antiseptics for 6 weeks, and also of regular bladder washouts, were noted. All urine specimens were infected except 24% during antibiotic treatment and 9% during antiseptics and 6% after washouts. Only washouts reduced the extent of catheter blockage. There was little difference in the time in situ between silastic and latex Foley catheters--only 31% of silastic remaining for longer than 4 weeks. Bard-Roberts catheters were the least satisfactory. Catheter leakage was not affected by urinary pH. Further development in long-term catheter management are needed.


Identification of MSH release-inhibiting elements in the neurointermediate lobe of the rat. Neurointermediate lobes of rats comprise elements which, when excited in vitro, bring about an inhibition of the release of melanocyte stimulating hormone (MSH). Superfusion of neurointermediate lobes of intact donor rats with medium containing 45 mM K+ induced a stimulation of the release of oxytocin, arginine-vasopressin and dopamine (DA) and inhibited the release of MSH. Fluorescence histochemical observations and the results of release studies indicate that electrothermic lesions in the mediobasal hypothalamus induced a more rapid degeneration of dopaminergic than of peptidergic terminals in the neurointermediate lobe. Dopaminergic nerve terminals and the stimulated release of DA had vanished completely on the second day after these lesions, which coincided with the disappearance of K+-induced inhibition of MSH release. Frontal hypothalamic deafferentations resulted in disappearance of peptidergic nerve terminals as evidenced by the development of diabetes insipidus and the strong decline of depolarization-induced release of oxytocin and vasopressin from neurointermediate lobes in vitro. In contrast, the dopaminergic plexus was left intact, as was the K+-induced stimulation of DA release and inhibition of MSH release. We conclude that the K+-induced inhibition of MSH release is mediated by DA rather than by neuropeptides from terminals in the neurointermediate lobe. The results are in agreement with the proposed MSH release-inhibiting role of the dopaminergic tuberoinfundibular neurones.


Translocation of cytosol protein kinase into nuclei and the induction of tyrosine hydroxylase in NBD-2 neuroblastoma cells. Exposure of neuroblastoma cells (NBD-2) to 8-bromo-adenosine 3',5'-cyclic monophosphate (0.2-1.0 mM) (8-Br-cAMP) for 15 min caused a long term increase in the Vmax of tyrosine-3-monooxygenase activity (TH) beginning about 1 day after 8-Br-cAMP application. Cyclic AMP-dependent histone kinase was maximally activated in about 30 min and stayed activated above pretreatment levels for one hour. In cells exposed to 8-Br-cAMP for 15 min, separation of soluble and particle bound histone kinase showed that the total histone kinase activity in the soluble fraction decreased by 40%. This decrease was accompanied by an increase in protein kinase activity in the particulate fraction, suggesting enzyme translocation. After translocation, the enzyme appears to acquire a different substrate affinity because it prefers as a PO43- acceptor, acidic protein rather than histone. In NBD-2 cells this kinase appears to precede, and may be related to, the delayed increase in TH Vmax.