The skin biopsy in the diagnosis of acute graft-versus-host disease in man. Criteria for diagnosis of acute graft-versus-host disease (GVHD) using skin biopsies were derived from a) general experience with more than 300 human marrow grafts and b) the results of "blind" studies of skin biopsy specimens of patients grafted with either allogeneic or syngeneic marrow. Large doses of cytotoxic drugs and irradiation given before grafting can produce transient skin changes interfering significantly with the diagnosis of GVHD. Artifacts can also cause difficulty. Epidermal cytologic atypia, dyskeratosis, and satellitosis were present both in allografted patients with acute clinical GVHD of multiple systems and in patients given autologous or syngeneic marrow. Due to the marked overlap in histopathologic findings between these two types of skin injury, frequent serial skin biopsies must be combined with all other available clinical and biopsy data to provide reliable diagnosis of acute GVHD in man.


Cytoplasmic dipeptidase activities of kidney, ileum, jejunum, liver, muscle, and blood. Peptide hydrolase activities against glycyl-L-leucine and glycylglycine were investigated in the soluble fractions of blood, liver, kidney cortex, skeletal muscle (gastrocnemius), and jejunal and ileal mucosa of rats. The maximal hydrolase activity in each tissue was determined when the incubation conditions, such as time, pH, substrate and enzyme concentrations, and ionic requirements were optimal. The kinetic constants (apparent Km and Vmax) were determined from Lineweaver-Burk double reciprocal graphs. Maximal hydrolysis rates against both dipeptides were many times greater by kidney and intestinal segments than by those of muscle, liver, or blood. The order of Vmax for hydrolase activity against glycylleucine was kidney greater than ileum greater than jejunum greater than liver greater than muscle greater than blood, and the order against glycylglycine was ileum greater than kidney greater than jejunum greater than liver greater than muscle. Those tissues that had the lowest Vmax values (liver and muscle), when calculated on the basis of tissue weights, were shown to have activities comparable to the others. Results of this study are consistent with our previous findings that: 1) glycylleucine half-life in plasma is shorter than that of glycylglycine, and 2) disappearance rates of these dipeptides from plasma are not affected by nephrectomy or enterectomy.


Transport of H+ against electrochemical gradients in turtle urinary bladder. Active H+ transport (JH) by the isolated turtle bladder was inhibited by either an applied chemical gradient (deltapH) or an electrical gradient (deltapsi). The relation of JH to either deltapH or deltapsi was linear, and the slopes and the force gradients required to bring JH to zero were similar with both methods. The transport system was analyzed in terms of an equivalent circuit model comprising a proton motive force (PMF), an active conductance (LH) in series with the pump, and a parallel or passive conductance which may be ignored in this preparation. Increasing ambient PCO2 markedly increased JH and the active conductance (as deltaJH/deltadeltapH) but had no effect on the apparent PMF (PMF'). Similarly, acetazolamide caused comparable decreases in JH and LH without change in PMF'. Inhibition of metabolism by deoxygenation, deoxy-D-glucose, or depletion of metabolic substrate caused large decreases in JH and LH with reduction in PMF' of less than 14%. Glucose addition increased JH and LH but caused a slight decrease in PMF'. Thus, the experimental maneuvers affected the transport rate primarily through changes in the active conductance. Since PMF' was little affected, the force of the pump must be determined by factors other than the metabolic driving reaction alone. Conductance factors relating to transport as well as to metabolism participate in controlling PMF.


Hydrogen ion metabolism.

Hydrogen ion metabolism. The renal and respiratory systems regulate acid base homeostasis by modifying the bicarbonate buffer pair HCO3- and CO2; other buffer systems adjust to alterations in this pair. The pH change following addition of metabolic acid, or base, is modified initially by the body's buffers. Subsequent respiratory compensation, by retention or excretion of CO2, modifies further this change before renal corrective responses finally occur. A primary respiratory acid base change is modified initially by cellular buffers, with renal compensatory mechanisms adjusting slowly to this change. However correction of the respiratory pH disorder only occurs with correction of the primary disease process. The body's capacity, therefore, to adjust to a matabolic acid base defect, appears greater than that observed with a primary respiratory pH abnormality. Treatment in all acid base disorders focuses initially upon the primary diseases process; thereafter therapeutic manipulation of the HCO3-, CO2 buffer pair, to aid the body's compensatory processes, can be considered.


Specific drug interactions in anaesthesia. The sites and mechanisms of the interaction of drugs have been discussed with special relevance to the work of the anaesthetist.


[Flunitrazepam, trazodone and sulpiride in the treatment of recovery reactions after ketamine anesthesia]. The authors studied the effects of flunitrazepam, trazodone and sulpiride on recovery reactions following ketamine anaesthesia, in male patients aged between 15 and 25 years, following minor orthopaedic surgery. Only flunitrazepam and trazodone proved to be effective, whilst sulpiride was quite useless in the prevention of recovery reactions. The authors nevertheless feel that trazodone is preferable to flunitrazepam since it reduces all recovery reactions and, in particular, because it reduces the agitation induced by ketamine, rendering the pseudo-hallucinations pleasant, and because it is free of the hypnotic component of flunitrazepam, often inconstant and sometimes responsible for the patient swallowing his tongue.


[Changes in the affinity of oxygen for hemoglobin during general anesthesia]. The well known effects of the lowering of the intraerythrocyte 2, 3, diphosphoglycerate (2, 3, DPG) level and hypothermia, on the affinity of oxygen for hemoglobin, lead the authors to study the influence of these parameters on this affinity during general anesthesia. The following observations were made in 15 adult subjects, undergoing prolonged general anaesthesia (average time: 3 hrs. 10 minutes): the dissociation curve of oxyhemoglobin (DCO) by the method of mixing, the intraerythrocyte 2,3, DPG level, the hemoglobin concentration and arterial blood parameters (PO2, PCO2, pH). These measurements were recorded before and after the general anaesthesia. The results were the following: a significant reduction of P50, measured under standard conditions (from 27.64 +/- 1.74 torr to 25.57 +/- 2.28, p less than or equal to 0.01) associated with a decrease in 2,3, DPG (from 0.94 +/- 0.31 mol/mol Hb at 0.64 +/- 0.24 p less than 0.01). Among the factors responsible for this variation in the affinity, it was proved that the volume of blood transfused was of importance as well as a decrease in body temperature during the operation. When the temperature is made to vary from 37 degrees C to 35 degrees C. the P50 ranges from 25.57 +/- 2.28 to 22.86 +/- 0.97 (p less than 0.01). To conclude the authors underline the importance of hypothermia and the volume of blood transfused (average time of preservation = 15 days) on the effects of the affinity of oxygen for hemoglobin.


[Evaluation of per- and postoperative bleeding in 250 poro-metal total hip prostheses without cement]. Arthroplasty of the hip without cement in poro-metal (JUDET type) represents real progress. However, per-operative bleeding is greater, 48 per cent of patients losing more than 2000 ml and 25 per cent more than 3000 ml. Various factors may influence the degree of haemorrhage: the operative indication, the time of the operation and the administration of Calcium heparinate are studied. Postoperatively, overall blood loss then in relation to per-operative bleeding were evaluated.


[Effects of high doses of morphinomimetics (fentanyl and fentathienyl) on the cerebral circulation in normal subjects]. The effects of large doses of morphinomimetics on the cerebral circulation were studied in 12 normal subjects (fentanyl 16 microgram/kg in 6 patients and fentathienyl 1.9 microgram/kg in 6 others). Mean hemispheric flow (corrected to a pCO2 of 40) changed from 50.8 +/- 4.4 ml/100 g/min in the conscious state to 50.3 +/- 25.1 under the influence of fentanyl, and flow in the grey matter from 78.8 +/- 10 to 84.3 +/- 65 ml/100 g/min. Mean flow changed from 49 +/- 3.1 ml/100 g/min in the conscious state to 55.5 +/- 10 under the influence of fentathienyl, flow in the grey matter increasing from 75 +/- 9 to 81.8 +/- 14.4. Whilst there was no variation in mean flow rates under the influence of morphinomimetics, individual behaviour was very variable, in particular in the case of fentanyl, the changes produced by fentathienyl being much more homogeneous. There was no obvious modification in the distribution of regional flow by these morphinomimetics. Individual variations in flow correlated perfectly with individual variations in cerebral oxygen consumption. Vascular reactivity to CO2 was increased b morphinomimetics. In one subject, fentanyl produced a very marked increase in cerebral blood flow (+ 104 p. 100) for which no explanation could be found.


[Current aspects of gas gangrene, apropos of 47 cases collected over a 3-year period (1974-1976)]. On the basis of 47 cases of gas gangrene collected over the three year period between 1974 and 1976, the authors review the circumstances surrounding its development, the clinical features and the prognosis of the disorder which remains grave despite a well-defined therapeutic protocol combining surgery, antibiotics and hyperbaric oxygen. There would appear to be a real resurgence of the disease at the present time. Post-traumatic and surgical aetiologies predominate, giving rise to two types of gangrene: clostridial gas gangrene secondary to contamined wounds, with a quasi-constant vascular element, affecting predominantly the limbs, and nonclostridrial gangrene, the increasing prevalence of which involves essentially spetic abdomino-pelvic surgery. In the light of this study, prognosis would appear to be related to the underlying terrain in which the gangrene occurs, to certain features of the clinical picture and, above all, to the possibilities of early application of the complete therapeutic protocol. Strict prophylactic measures would alone seem capable of preventign the worrying increase in the number of cases of gas gangrene.


[Early complications after pleuro-pulmonary surgery. Study based on 217 operated patients]. In a study involving 217 patients who had undergone thoracotomy, the authors noted 85 complications in 77 patients with a mortality of 2.5 per cent. Respiratory complications were the most common but never ended in death. By contrast, cardiac complications are the most severe. The absence of mortality of respiratory origin is certainly the result of regourous pre-operative selection based upon overall and separate pulmonary function studies. The great rarity of pulmonary embolism is related to routine postoperative preventive heparin therapy.


[Bacteroides fragilis septicemia].

[Bacteroides fragilis septicemia]. On the basis of eight cases of Bacteroides fragilis septicaemia, the authors review recent data from the literature related to this topic. They first note the increasing prevalence, accounting for approximately 10 per cent of all septicaemias at the present time. They note that the most frequent portals of entry are sites of localised suppuration, related on the one hand to digestive or gynaecological surgery and, secondly, to the post-partum or post-abortum period. From a therapeutic standpoint, they stress the important role of imidazole derivatives (metronidazole or tinidazole) which are the most effective antibiotics at present. Certain authors even suggest their use on a preventive basis in high risk subjects.


[Thiamine deficiency in chronic alcoholics. Value of pre- and postoperative treatment]. Thiamine deficiency in the chronic alcoholic would appear to have a triple origin: inadequate intake, absorption and utilisation. Its consequences are well known: peripheral neuropathy, WERNICKE and KORSAKOFF type encephalopathies and cardiac problems (with asystole at the extreme). The active principle of thiamine, TPP or cocarboxylase, is involved as a coenzyme of pyruvate decarboxylase and of alphaketoglutarate decarboxylase in the ocidative decarboxylation reactions of the Krebs cycle. TPP is involved as a coenzyme of transketolase in the transketolisation reactions of the pentose pathway. The stimation of transketolase demonstrates a deficiency in thiamine. Fourteen patients suffering from surgical ENT malignancies were involved in the present study. Seven patients received vitamin B therapy before and after the operation. The results showed a significant decrease in thiamine deficiency. Seven were used as controls and did not receive vitamin B therapy. Transketolase estimations showed and increase in the deficiency. Thiamine deficiency exists in the chronic alcoholic and may be corrected by the administration of B vitamins.


[Pulmonary mechanics and alveolar exchanges in the elderly with apparently healthy lungs. Preliminary study]. A group of ten elderly subjects who were apparently normal from the cardiac and pulmonary points of view, were selected on criteria of history, clinical findings, radiological and E.C.G. findings, with a view to a study of respiratory function based on two aspects: alveolar exchanges were assessed by measurement of the ductance of carbon monoxide and the elastic properties of the lung together with bronchial permeability. Although alveolar exchanges are little modified, one may note some pulmonary distension, especially in the smokers, together with a reduction in elasticity. The changes in bronchial permeability which affect the peripheral and central airways, are mainly found in smokers. One may determine the respective roles of extrinsic and intrinsic bronchial obstruction in these abnormalities. One may thus consider that, from the pulmonary point of view, the elderly patient faced with a surgical operation should be considered a high risk for respiratory decompensation, especially if he is, or has been, a smoker.


[The aged heart in surgery].

[The aged heart in surgery]. The risk of surgical operation is increased by the presence of heart disease. The statistics are too limited for this risk to be expressed more precisely. The heart in the elderly is no longer a normal heart. The myocardial functional reserve declines, the quality of the A.V. conduction is not always good and vascular fibrosis progresses. Surgical operation thus increases the risk of a cardio-vascular accident. One should distinguish the risk due simply to old age. The existence of known heart disease often leads to heart failure which is difficult to treat. The great risk of surgical operation is then the risk of overloading the heart. In the absence of known heart disease, one should beware of latent coronary insufficiency. The major risk is then hypoxia. The special problem of degenerative A.V. conduction disorders may require the insertion of a pace-maker. Pre-opératoire cardio-vascular assessment is thus necessary in the elderly subject. It should, however, remain simple. Careful history and auscultation, verification of the periphéral arteries, chest XRay and E.C.G.


[Postoperative nitrogen balance in the elderly. Effects of an anti-aldosterone drug]. A previous study led us to believe that the use of anti-aldosterone treatment in the immediate post-operative phase of abdominal surgery ensured energy saving in nitrogen balance. In fact, if massive restoral of water and electrolytes proves necessary, the optimum sodium and potassium intake during the use of soludactone, does not appear to be the only factor liable to influence significantly nitrogen balance or, at least, positive nitrogen balance. We are now attempting to apply our experience to the same problem in the elderly.


[The brain in the aged].

[The brain in the aged]. Under the very broad term of brain in the elderly, we cannot consider exhaustively all the anatomical, physiopathological and pathological aspect and, still less, the therapeutic possibilities in diseases of the anesthetist should know concerning the special characteristics of this aging organ. First are recalled the anatomical, macro and microscopic data of the senile brain. The metabolic characteristics are then considered. Investigations which may give the clinician information concerning the organic state and metabolic capacities of the brain of the elderly subject, e.g. cerebral blood flow, fundus oculi, E.E.G. brain arteriography, tacography or tomodensitometry by scanner, are consideres. But in practice, they are difficult to use and their data are only relatively reliable, i.e. clinical examination is of great imporatnce and the overall impression prevails. The therapeutic possibilities are limited and in these elderly subjects with cerebral metabolism in unstable equilibrium, one should be circumspect and careful in treatment.


[Confusional states in geriatrics].

[Confusional states in geriatrics]. Illustrated by clinical reports, this study attempts to demonstrate the practical and didactic interest of various somatopsychological correlations in geriatrics. The confusional state in the elderly has no specific etiopathogenesis. It is only the expression, often disconcerting, of a method of cerebral suffering and the clinician should be aware of its various presentations. The precipitating factors are not only of organic or iatrogenic origin, but often psychological. Any change is considered by the elderly patient as dangerous and worrying. Our perfectly justified fear of inaction and passivity together with a desire for rapid efficacy, should not lead us to forget that in geriatrics more than in any other branch of medicine, a prudent attitude in therapeutics is most likely to be successful.


[Age and other factors in the prognosis and operative indications for brain surgery]. Attempt at evaluation of the operative risk depending on seven factors. 1--For benign tumours (Example: meningiomas): 1--greater than 65 years; 2--functional insufficiency, depending on the type of tumour; 3--the volume of the tumour; 4--site of the tumour; 5--foreseeable operative difficulties; 6--the importance of intra-cranial hypertension and the level of pre-operative consciousness; 7--life expectancy, quantitative and qualitative. II--Extrapolation of the previous equation to malignant tumours, chronic sub-dural hematoma, intra-cerebral hematoma and surgery of pain.


[Admission and treatment of 592 patients over 70 years in an intensive care unit]. Using an IBM 3741 computer, the authors analysed 592 case records of patients aged over 70 years, admitted to hospital on an intensive care unit, age appears to be an important factor in determining the prognosis of numerous diseases without, however, being a criteria for rejection of admission of these patients to an intensive care unit. The fragility of these patients leads one to consider the following parameters: 1--the degree of resuscitation is assessed by quantification of the therapeutic means. As for other patients, survival varies inversely in relation to the important of the therapeutic means, but in the case of the elderly patient, there is a definite difference in the correlation mortality-therapeutic index towards aggravation, so one may determine a ceiling above which survival is not possible; 2--duration of the intensive care is very important. In most cases, the decisive point is situated on the 3rd or 4th day of care, at which time the decision to continue or stop treatment may be considered in the light of the patient's progress.


[General anesthesia for ophthalmic surgery in patients over 80 years]. Among 150 elderly ophthalmological patients over 80 years old, only seven patients did not undergo a general anaesthesia, because of respiratory insufficiency and/or ventricular extrasystoles. The other, 143 patients underwent 178 operations under general anaesthesia with minimal per and postsurgical complications. Therefore, it seems unjustified to deny the benefit of general anaesthesia to ophthalmologic surgical patients more than 80 years old.


[Methods and indications for low peridural analgesia in the aged. Report of 300 cases]. Continuous peridural analgesia took a long time to be accepted in current practice in surgery of the elderly, owing to the apprehensions for the possible cardiovascular consequences and also, the difficulty in using this form of anaesthesia in the elderly. The experience of more than 300 cases, collected in the Nice department of Anesthetics and Intensive Care, has shown that: 1--technical failures are exceptional with routine use of prior epidurography; 2--its indications depend on the site and type of surgery and on the clinical conditions of the patient; 3--until now, there have been no severe complications due to this method whatever the degree and number of morbid conditions; 4--in the elderly subject, the importance of problems of pre and post-operative analgesia have led us to enlarge the indications for long-term peridural analgesia. Peridural anesthesia may be used as a routine when the site of the operation involves areas situated below the IXth metamere. This shows its importance in surgery in the elderly.


[A comparative study of the course of aged patients with hip surgery]. On an orthopedic surgical unit we studied the course of patients aged over 70 years who had undergone surgical operation on the hip in 1974 and 1975. Distinguishing the pre-opérative, per-operative and post-operative stages, we used firstly, the distribution according to age and sex, the past history, the laboratory findings, the type of operation and the type of anesthetic. Then, we carried out a comparative analysis in relation to the past history, the post-operative complications and the deaths.


[Pharmacoloby of the bronchomotor tonus during anesthesia]. In a patient under general anesthesia, the occurrence of bronchospasm can be readily treated provided the cause is diagnosed early. The corrective drugs to dilate are readily available: atropine, epinephrine and theophylline. In the choice of preanesthetics, anesthetics and adjuvants, it is important to remember that there are differences in the bronchomotor effects; most curareform drugs constrict except pancuronium; most inhalational anesthetics dilate in contrast to intravenous anesthetics. In the event that bronchospasm cannot be re relieved by drugs, intubation and assisted breating can be applied to maintain adequate gas exchange in the alveoli.


[Metabolic and pharmacologic interactions on the bronchial tonus]. After reminding data concerning the part played by the as a rule antagonist cAMP system in moticity of the smooth muscle fibers in general and of the bronchial fibers in particular, the authors study the different types of interaction on bronchial muscular fibers which have been discribed. It is concerning the adrenergic fibers that the experimental and clinical data are prevalent (role of bronchial alpha- and beta2- receptors) and the authors point especially to their own studies performed since 1964 concerning the alpha1- -bronchoconstrictive component and progressive auto-inhibition of the bronchial beta2- receptors. But autacoids (serotonin, bradykinin, histamine and prostaglandines) and with the stimulating or inhibiting agents of the beta2 -receptors also begin to be recognized.


[Determination of global diffusion of CO2 and its partial components under assisted respiration. Technical problems and practical value in respiratory resuscitation]. A study of partial CO2 ductance has been performed in patients under assisted ventilation. The authors propose methods for simultaneous measurement of paCO2, PAECO2, PECO2 and PICO2. This methodology is used in patients presenting different conditions accounting for respiratory resuscitation: barbiturate poisoning with healthy lungs, bronchial stasis, acute lung involvement, obstructive bronchopneumopathy and pulmonary embolism.


[Bronchial spasm and bronchial motoricity]. The author recalls the phenomena which control bronchomotility, without a personal study but based on recent bibliography. After recalling the bronchial nerve supply, the chemical intermediates, the various responses of the bronchial tree to autacoids, the author recalls the association of anesthesia and bronchospasm. Although the bronchial reactions of histaminic origin are the most frequent, mechanical or chemical irritation is recalled with an elementary description of "irritant receptors" and stretch receptors. Finally, the other causes of bronchial narrowing are considered: vago-sympathetic imbalance, atopic background, influence of the anesthetic on vagal tone or on adrenal medullary secretion.


[Peroperative pneumothorax].

[Peroperative pneumothorax]. Pneumothorax during operation is always clinically serious. The symptoms are usually sudden cyanosis, accompanied by cardio-vascular collapse and difficulty or even impossibility to ventilate owing to increased pressures of insufflation. Immediate or secondary bilateral pneumothorax is relatively common, then may appear associated complications such as subcutaneous emphysema or pneumo-mediastinum. Early diagnosis is necessary to apply simple treatment and avoid a course which may be rapidly fatal. The authors report 3 cases of pneumothorax during anesthesia and consider the clinical forms, the mechanisms and causes of this accident.


[Significance of capnography in cases of pneumothorax occurring during artificial respiration]. The author reports the case of a premature new-born presenting a respiratory distress syndrome who was ventilated through a tracheal tube and in whom an artificial pneumothorax developed. Capnography quickly provided accurate data allowing an adaptation of therapy.


[Inhalation of regurgitated fluid during anesthesia]. Since the observations of HALL in 1940 and MENDELSON in 1946 numerous clinical and experimental reports have completed our knowledge of the consequences of inhalation of fluid during anesthesia. Apart from the pulmonary signs, this syndrome includes cardiovascular signs. The course of the pulmonary disease is often unfavourable. Frequently, diagnostic problems are raised a posteriori in the light of respiratory distress and abnormal pulmonary radiological signs. It is then sometimes difficult to distinguish the role of the position on the operating table, the role of massive transfusion without adequate filtration, a state of shock, or unrecognised inhalation of fluid. The various problems are exposed. The interest of prevention and treatment is discussed.


[Complications following cementing of joint prosthesis]. The authors studied changes in the level of lactate dehydrogenase during insertion of hip prostheseis fixed with methyl methacrylate cement. Thirty patients were studied here. In 23 of them, the L.D.H. isoenzymes were estimated. The variations in these enzymes appear 3 hours after the second fixation with cement: rise in L.D.H., isoenzyme 5, (of skeletal muscle origin) of isoenzymes 3 and 4, (of pulmonary origin). This is a sign of pulmonary involvement even in the absence of clinical signs.


[Pulmonary edema due to peroperative overload or anesthetic awakening]. This report gives details of the clinical characteristics, the circumstances of onset and the treatment. There is always a blood volume overload, but the absolute value does not differ radically from that often necessary to maintain during heavy or hemorrhagic surgery, good hemodynamic conditions. The association with other factors seems necessary, in particular the redistribution in blood volum which occurs during awakening or reduction in anesthesia. Treatment by reduction in blood volume (bleeding, diuretics) is often insufficient. Many cases require mechanical ventilation for several days. Ventilation under continuous positive pressure may even be essential. The frequency of these accidents may even rise for several reasons: vasoplegic anesthesia, routine restoration of blood volume for hemodynamic reasons or to protect the kidneys, occasional failure of C.V.P. as means of control of this restoration, wider and wider use of red cells concentrates and colloids without precise knowledge of their properties.


[Anaphylactic reactions observed with anesthetics and adjuvants]. The author reports an inquiry concerning 66 patients who all had an anaphylactoid reaction. The hour of onset, the type of reaction, (skin, bronchial or systemic), their association, the drugs responsible, and the diagnostic difficulties are reviewed. In this respect, in relation to the results of the above inquiry and the data in the literature, the skin and bronchial reactions are described, and the signs of anaphylactic shock recalled. The substances possible are then reviewed with the possible correlation between the type of accident and the drug responsible. Finally the role of macromolecules is discussed.


[Effects of anesthesia and surgery on certain parameters of humoral immunity]. Research on certain parameters of humoral immunity was undertaken in 10 patients who had undergone a major surgical operation. The control subjects were chosen among 10 subjects in good health. The tests were carried out within 24-72 hours after the operation. The determination of cytolytic lymphocyte activity, in the presence of specific antibodies, was strongly lowered in the postoperative period. This was also the case with the capacity to form EAC lymphocyte rosettes. Finally total serum complement was lowered significantly whereas factor C3 remained normal. These results show a change in humoral immunity in the postoperative period together with a reduction in complement activity.


In vivo function tests of the effect of tilorone and niridazole on cell-mediated immunity in chickens. The need for effective, safe, specific cellular immune suppression in avian research led to the study of effects of tilorone and niridazole on cell-mediated immunity of chickens. Two in vivo tests for cell-mediated immunity function were used--the graft-vs-host (GvH) test and the delayed hypersensitivity (DH) test. Humoral immunity was evaluated by measuring natural hemagglutination (HA) titers against rabbit red blood cells. Intraperitoneal administration of tilorone to young chickens appeared to have severe toxic side effects and was of little value as an immune suppressant. Oral administration of tilorone to 6-week-old chickens caused DH suppression, but no marked effect was seen on GvH reactions or HA titers. Toxicosis appeared less severe. Oral administration of niridazole to 6-week-old birds caused nearly complete loss of GvH and DH reactivity but caused an increase in HA titers. General toxic effects of niridazole were not apparent.


Pharmacological and psychological determinants of smoking. A New York University honors program lecture. Arguments for and against low-nicotine cigarettes are examined by considering evidence relevant to the gratification of smoking and to nicotine as an addicting agent. A variety of studies indicates that smokers regulate nicotine intake and that variations in smoking rate that customarily have been interpreted in psychological terms are better understood as attempts to regulate nicotine. These findings bring into question the justification for the low-nicotine cigarette campaign.


[E. coli penicillin amidase. Physico-chemical properties of the enzyme covalently bound to the 2-(3'-amino-4'-methoxyphenyl)-sulfonylethyl ester of cellulose]. The effect of the procedure of the enzyme binding with the carrier on the properties of the heterogenous catalyst obtained by covalent binding of penicillinamidase (PA) with cellulose 2-(3'-amino-4'-methoxyphenyl)-sulphonylethyl ether by means of the bifunctional reagent, i.e. glutaric aldehyde was studied. It was shown that the amount of the bound enzyme increased with a rise in the amount of the enzyme taken for the binding, while the binding efficiency characterizing the part of the active enzyme in the total amount of the bound PA decreased practically 2 times. The use of the enzyme preparations with different purify levels for the binding provided differentiation of the effects resulting in the activity loss on immobilization. In other words it provided separate estimation of the inactivation effect of the matrix and the immobilization procedure, as well as the interaction of the enzyme molecules with each other and other protein molecules.


[Physiochemical properties of 7-aminoacetoxycephalosporanic acid]. Potentiometric titration of the zwitter-ion of 7-aminoacetoxycephalosporanic acid (7-ACA) was performed and the constants of its ionization were estimated. The minimum solubility of the 7-ACA zwitter-ion (20 degrees C, 0.1 M NaCl) was determined and the solubility curve of 7-ACA at wide pH ranges was calculated. Equilibrium of the cationic, zwitter-ionic and anionic forms of 7-ACA was estimated as dependent on pH.


[Use of a polarographic method for determining trichothecin]. The polarographic behaviour of trichothecin was studied. It was shown that the antibiotic could be detected in solutions at concentrations of 7.10(-7) moles with the help of the polarographic method. Conditions for the polarographic determination of trichothecin in fermentation broth were developed. The error was not more than 3 per cent. The reliability of the results was shown by statistical treatment of data performed in accordance with the requirement of the USSR State Pharmacopeia, X ed., prescribing that the precision of the assay is such that the fiducial limits at p = 95 per cent deviate from the average value by not more than 5 per cent. Comparison of the results of trichothecin determination in the fermentation broth with the polarographic and biological methods showed no significant difference. Therefore, the polarographic method may be recommended for trichothecin determination in the fermentation broth.


[Detection of weak graft-versus-host reactions by the suppressive effect on the immune response (author's transl)]. Weak graft-versus-host reactions induced between H-2 compatible strains are not detected by the splenomegaly assay in newborn mice. Similarly the proliferative response in the mixed lymphocyte culture or the popliteal lymph node assay was not extensive in some combinations. On the contrary, the inhibition of the specific immune response to heterologous red cells was observed when graft occurred from 15 days before immunization. So the weak graft-versus-host reactions appeared to be easily detected by the suppressive effect on antibody synthesis.


Discovery of an agent in wastewater sludge that reduces the heat required to inactivate reovirus. An agent that causes heat inactivation of reovirus to occur at reduced temperatures has been found in both raw and anaerobically digested sludge. This agent is originally associated with sludge solids but can be washed from these solids by blending with water. The activity of the agent was considerably greater in alkaline than in acid solutions, probably because it is insoluble at low pH. The agent was shown to be nonvolatile and heat stable up to 300 degrees C but was inactivated within 30 min at 400 degrees C. The rate of heat inactivation of reovirus by the agent was found to occur in a bimodal fashion and to be relatively rapid, even at 35 degrees C. Finally, it was found that this agent did not accelerate heat inactivation of poliovirus, but instead may be the component of sludge previously found to protect poliovirus against inactivation by heat.


Cerebrospinal fluid acid-base status and lactate and pyruvate concentrations after short (less than 30 minutes) first febrile convulsions in children. Twenty-nine infants and children with short (less than 30 minutes) first febrile convulsions were studied between 3 and 22 hours after convulsive episodes. Arterial and CSF acid-base variables, lactate and pyruvate concentrations, and lactate/pyruvate ratios were measured. Biochemical signs of cerebral hypoxia were found in only 2 patients, one of whom had short, repeated convulsions. Our findings indicate that hypoxic damage is unlikely to result from a short-duration febrile convulsion.


Cerebrospinal fluid acid-base status and lactate and pyruvate concentrations after convulsions of varied duration and aetiology in children. Twenty-two infants and children were studied after convulsions of varied cause and duration. Arterial and CSF acid-base variables, lactate and pyruvate concentrations, and lactate/pyruvate ratios were measured between 3 and 18 hours after convulsive episodes. Biochemical signs of cerebral hypoxia were found in 7 patients with prolonged (greater than 30 minutes) or recurrent short convulsions. These signs were absent in patients with single short convulsions. These findings indicate that cerebral hypoxia and possible brain damage is a hazard of prolonged or rapidly recurring short convulsions.


Hemodynamic effects of prolonged hyperoxia. Experimental studies have consistently demonstrated the development of perivascular edema in the dog lung following prolonged exposure to 95% oxygen. This pathological change has been thought to result from capillary injury, but a direct effect secondary to left ventricular dysfunction has not yet been excluded. To evaluate the latter possibility, ten trained, awake dogs were prepared with monitoring of right and left atrial, systemic and pulmonary artery pressures, cardiac output, and mixed venous and arterial blood gases. Animals were exposed to an F1O2 greater than 0.95 for 48-70 hours. Radioactive 8-10 mu microspheres (141Ce, 51Cr, 85Sr, 46Sc) were injected into the left atrium at zero, six, 24, and 48 hours. PaO2 was 480 +/- 10 mm Hg during exposure, and the pulmonary shunt fraction increased from 11.3% to 16.9% (p less than 0.0001) during 70 hours. Left atrial pressure fell from 9 +/- 2 mm Hg to 3 +/- 3 mm Hg (p less than 0.0001), but cardiac output was constant at 2.7 +/- 0.1 l/min. Pulmonary arteriolar resistance increased from 183 +/- 20 dynes-sec-CM-5 to 791 +/- 30 at 70 hours (p less than 0.0001). Histologic sections of the lungs demonstrated the characteristic perivascular edema. Of particular interest was the fact that myocardial perfusion was significantly increased to all three layers of the ventricular wall at 24 and 48 hours. These data indicate that perivascular edema developing after exposure to high concentrations of oxygen is secondary to pulmonary capillary endothelial damage with no evidence that myocardial dysfunction occurs during this period.


Is a left ventricular vent necessary during cardiopulmonary bypass? This study evaluated the coronary flow and the internal diameter, pressure, and metabolism of the left ventricle using four different cardiopulmonary bypass techniques. Conditioned dogs underwent a 30-minute stabilizing period on cardiopulmonary bypass with a beating, empty heart (normothermia and a flow of 80 ml/kg/min). They were then fibrillated and subjected to four experiments: Group A (7 dogs)--left ventricular vent, caval tapes open; group B (7 dogs)--left ventricular vent, caval tapes closed; group C (7 dogs)--no vent, caval tapes open; group D (4 dogs)--no vent, caval tapes closed. There was no major difference in any of these variables among Groups A and B (both ventricles vented). Group D (no vent, tapes closed) had significantly increased wall tension, decreased coronary flow, decreased subendocardiac flow, and ischemia. In contrast, Group C dogs (no vent, tapes open) had only a slight increase in left ventricular diameter and pressure, with no change from Group A and B dogs in coronary flow, lactate extraction, hydrogen ion production, or potassium difference. Therefore, venting the fibrillating ventricle, either with or without snaring of the caval tapes, is probably the best method to use during the distal anastomosis in a coronary artery bypass operation. However, if a vent is not used, the caval tapes should be left open to allow complete diversion of the venous blood and decompression of the left ventricle.


Effect of some beta-adrenergic blocking drugs on the renal bloow flow in dogs. Using timed collection of blood returning via the renal veins, the renal blood flow was determined in anaesthetized dogs, following the intravenous injection of 3 beta-adrenergic blockers, namely propranolol, oxprenolol and pindolol. The test drugs were given as a bolus or as an infusion, and their effects on the renal blood flow and blood pressure were studied. All the test drugs produced diminution in both the renal blood flow and blood pressure. However, these effects were variable in degree. The diminution in the renal blood flow under the influence of beta-adrenergic blockers might be explained by concomitant reduction in the cardiac output and/or blockade of the renal vasodilator beta-adrenergic receptors. An added factor might by sympathetic stimulation with consequent renal vasoconstriction in the case of blockers with intrinsic sympathomimetic activity. Beta-adrenergic blocking drugs should be given with extreme caution in cases with impaired renal function.


Transmitter mobilization at the frog neuromuscular junction. During frequency facilitation of frog neuromuscular junctions depressed by Mg++, the relationship between quantal content (m) and frequency of stimulation (0.5 to 8 Hz) is exponential. The slope of the relationship (k) reflects transmitter mobilization and the zero-frequency intercept (mo) reflects the basic release process. The catecholamines, tetraethylammonium, guanidine and raised [Ca++]o increased mo but had no effect on k. At junctions where release ranged from 200 to 500 quanta sec-1 during steady-state conditions, this result was interpreted to mean that the drugs increased both transmitter release and mobilization. An analog of hemicholinium-3, DMAE, depressed k, reflecting the ability of DMAE to depress transmitter mobilization. The alternative possibility that the frequency facilitation relationship was altered by effects of the drugs on the number of activated release sites was also considered.


Further evidence for GABA-ergic mechanisms in the action of benzodiazepines. Drugs of the benzodiazepine series (clonazepam, lorazepam, diazepam and medazepam) increase the inhibitory processes in the cerebral cortex as it has been shown by means of the recovery cycles of the intracortical response. There is a correlation between the effect on the recovery cycles and their protective action against convulsions induced by GABA deficit. Diazepam enhances the inhibitory effect of GABA applied iontophoretically to rabbit sensorymotor cortex neurons. The drug GABA-ergic effect seems to be specific since it fails to modify the effects of other putative neurotransmitters (glutamate, glycine, acetylcholine). The alteration of rat conflict situation behaviour under diazepam has been eliminated due to the blockade of GABA-receptors by gicuculline and the decrease of the GABA level by thiosemicarbazide. It is inferred that the main effects of benzodiazepines are mediated by GABA and suggested that these agents increase the sensitivity of postsynaptic GABA-ergic receptors.


Resolution and reconstitution of Rhodospirillum rubrum pyridine dinucleotide transhydrogenase. II. Solubilization of the membrane-bound component. The Rhodospirillum rubrum pyridine dinucleotide transhydrogenase system is comprised of a membrane-bound component and an easily dissociable soluble factor. Active transhydrogenase complex was solubilized by extraction of chromatophores with lysolecithin. The membrane component was also extracted from membranes depleted of soluble factor. The solubilized membrane component reconstituted transhydrogenase activity upon addition of soluble factor. Various other ionic and non-ionic detergents, including Triton X-100, Lubrol WX, deoxycholate, and digitonin, were ineffectual for solubilization and/or inhibited the enzyme at higher concentrations. The solubilized membrane component was significantly less thermal stable than the membrane-bound component. None of the pyridine dinucleotide substrate affected the thermostability of the solubilized membrane-bound component, whereas NADP+ and NADPH afforded protection to membrane-bound component. NADPH stimulated trypsin inactivation of membrane-bound component to a greater extent that NADP+, but inactivation of solubilized membrane component was stimulated to the same extent by both pyridine dinucleotides. The solubilized membrane component appears to have a slightly higher affinity for soluble factor than does the membrane-bound component.


Influence of inorganic phosphate and organic buffers on cephalosporin production by Streptomyces clavuligerus. A high concentration of potassium phosphate (75--100 mM) stabilized pH and supported extensive growth of Streptomyces clavuligerus in a chemically defined medium; such a concentration also inhibited cephalosporin production. Although Tris buffer was found to have detrimental effects on growth and antibiotic production, 3-(N-morpholine)-propane sulfonate (MOPS) or 2-(NP-morpholine)-ethane sulfonate (MES) buffer provided a nontoxic buffering system. In the presence of MOPS buffer, cephalosporin production was optimal at 25 mM phosphate, whereas higher concentrations of phosphate progressively inhibited antibiotic production up to 85% without modifying the pH pattern. MOPS buffer can be used to conduct fermentations at a relatively constant pH value in shake flasks.


Prolactin responses to neuroleptics in normal and schizophrenic subjects. The prolactin response to neuroleptics can serve as an index of dopamine blockade in humans. Plasma prolactin increments to single doses of chlorpromazine, and prolactin decrements to single doses of levodopa, were similar in normal and schizophrenic subjects. Antischizophrenic drugs of all chemical classes stimulated prolactin release,while chemically related drugs and other psychotropic agents ineffective in schizophrenia did not. The prolactin response to neuroleptic therapy occurred in all patients, and tolerance did not develop. Within subjects, prolactin responses were graded according to neuroleptic dose, but the upper limit of sensitivity of the response curve was achieved at doses below the therapeutic range. Relative prolactin-stimulating potency in humans of chlorpromazine, thioridazine, trifluoperazine, butaperazine, and haloperidol correlated well with their relative clinical potencies.


The interferonogenic agent tilorone as a modulator of GvH reaction in mice. The effects of tilorone hydrochloride (TH), a powerful interferongenic agent exhibiting also immune modulatory properties on GvH reaction was studied, using the popliteal lymph node assay in mice. Administration of TH at days 0 or +2 relative to cell transfer to recipient mice led to a significant dose-dependent reduction of GvH reaction, whereas treatment of prospective donor mice at days-4 or-2 induced an enhanced GvH reactivity of donor spleen cells. This effect was found not to be due to an altered proportion in the spleen cell inoculum of B and T lymphocytes, the latter of which are responsible for induction of GvH reaction. However, since normal parental lymphocytes are prepared for an enhanced GvH reactivity by addition of TH-treated macrophages, a stimulatory effect of the latter cells via macrophage-derived mediators, induced by TH, is suggested.


Physiological basis of salt tolerance in plants. For most plants, and under most field conditions, osmotic effects of salinity greatly predominate in restricting growth and yields. In certain cases, however, specific ion effects may be decisive. These may involve either nutrition, as in calcium deficiency in some lettuce varieties, tomato, and bell peppers, or direct toxicity (chloride or sodium toxicity, or both) in tree and vine crops. Rootstocks, or varieties that restrict the uptake of toxic ions, increase the salt tolerance of some susceptible fruit crops. Salinity-induced nutritional imbalance can, in some cases, be corrected by selecting better adapted varieties and in others by the use of foliar nutrient sprays. Recent evidence indicates simple single-gene control over uptakes of chloride and sodium, but the more general osmotic effects appear to be complex and under multigenic control.


Characteristics and postnatal development of the acid lipase activity of the rat small intestine. Acid lipase was identified in the rat small intestine by using esters of 4-methylumbelliferone as substrates. Maximum activity towards the oleate ester was found at pH 4.0. In adult animals, the activity of acid lipase exhibited both latency and sedimentability, indicating a lyosomal localization. The activity of acid lipase was practically the same along the height of the villus, thus paralleling the distribution of acid beta-galactosidase. In adult rats, the activity of acid lipase in proximal (jejunum) and middle (mid-jejunum) sections of the small intestine was practically the same and exceeded the activity in the distal (ileum) section by a factor of 2. In suckling rats, the activity of the enzyme in the mid-jejunum exceeded that in the jejunum and ileum by 2.5- and 1.5-fold respectively. During postnatal development, the acid lipase activity of the mid-jejunum showed a peak between days 10 and 15, at which time it exceeded the adult mid-jejunum activity by 5--6-fold.


Biosynthesis of acetyl-coenzyme A in the electric organ of Torpedo marmorata in relation to acetylcholine metabolism. Formation of acetyl-CoA through acetyl-CoA synthetase (forward reaction) and through choline acyltransferase (backward reaction) was investigated in tissue extract from the electric organ of Torpedo marmorata. When the tissue extract was submitted to gel filtration on Sephadex G-25, the formation of acetyl-CoA by acetyl-CoA synthetase appeared fully dependent on ATP and CoA and partially dependent on acetate (an endogenous supply of acetate is discussed). Choline acetyltransferase was a potent source of acetyl-CoA, only requiring acetylcholine and CoA, and was much more efficient than acetyl-CoA synthetase for concentrations of acetylcholine likely to be present in nerve endings.


Growth of liver accompanied by an increased binding of aminoacyl-transfer ribonucleic acids. Homogenates of rat liver obtained 3 or 14 days after partial hepatectomy were used to prepare the postmicrosomal pH5-supernatant fraction and to prepare salt-wash fractions of the 40S ribosomal subunits and the 80S ribosomes. The factor-dependent binding of methionyl-tRNAfMet to ribosomes and the elongation-factor-1-dependent binding of phenylalanyl-tRNA to ribosomes were both increased after 3 days of growth, but not after 14 days of growth. An activity inhibitory to phenylalanyl-tRNA binding that was located in ribosomal wash fractions was decreased after 14 days of growth. Since the decreased inhibitory activity was obtained from the ribosomes and was tested against ribosomes and excess of pH5-supernatant fraction from control rat liver, its action was separate from the phenylalanyl-tRNA binding activities of the pH5-supernatant fractions from sham-operated and regenerating liver.


Transport and oxidation of choline by liver mitochondria. 1. Rapid choline oxidation and the onset of P(i)-induced swelling by liver mitochondria, incubated in a sucrose medium at or above pH7.0, required the addition of both P(i) and an uncoupling agent. Below pH7.0, P(i) alone was required for rapid choline oxidation and swelling. 2. Choline oxidation was inhibited by each of several reagents that also inhibited P(i)-induced swelling under similar conditions of incubation, including EGTA, mersalyl, Mg(2+), the Ca(2+)-ionophore A23187, rotenone and nupercaine. None of these reagents had any significant effect on the rate of choline oxidation by sonicated mitochondria. There was therefore a close correlation between the conditions required for rapid choline oxidation and for P(i)-induced swelling to occur, suggesting that in the absence of mitochondrial swelling the rate of choline oxidation is regulated by the rate of choline transport across the mitochondrial membrane. 3. Respiratory-chain inhibitors, uncoupling agents (at pH6.5) and ionophore A23187 caused a loss of endogenous Ca(2+) from mitochondria, whereas nupercaine and Mg(2+) had no significant effect on the Ca(2+) content. Inhibition of choline oxidation and mitochondrial swelling by ionophore A23187 was reversed by adding Ca(2+), but not by Mg(2+). It is concluded that added P(i) promotes the Ca(2+)-dependent activation of mitochondrial membrane phospholipase activity in respiring mitochondria, causing an increase in the permeability of the mitochondrial inner membrane to choline and therefore enabling rapid choline oxidation to occur. Nupercaine and Mg(2+) appear to block choline oxidation and swelling by inhibiting phospholipase activity. 4. Choline was oxidized slowly by tightly coupled mitochondria largely depleted of their endogenous adenine nucleotides, suggesting that these compounds are not directly concerned in the regulation of choline oxidation. 5. The results are discussed in relation to the possible mechanism of choline transport across the mitochondrial membrane in vivo and the influence of this process on the pathways of choline metabolism in the liver.


Alterations in nicotinamide and adenine nucleotide systems during mixed-function oxidation of p-nitroanisole in perfused livers from normal and phenobarbital-treated rats. The contents of adenine nucleotides as well as steady-state concentrations of a number of glycolytic, pentose phosphate-pathway and tricarboxylic acid-cycle intermediates were measured in extracts of livers from normal and phenobarbital-treated rats that were perfused with p-nitroanisole. Metabolites were measured in livers that were freeze-clamped during periods of maximal rates of drug metabolism. Treatment of rats with phenobarbital increased rates of p-nitroanisole O-demethylation approx. fivefold. The concentrations of lactate, xylulose 5-phosphate and ribulose 5-phosphate were increased by phenobarbital treatment, whereas that of fructose 1,6-bisphosphate declined. Perfusion of livers with p-nitroanisole produced significant increases in 6-phosphogluconate and ribulose 5-phosphate in livers from phenobarbital-treated rats, but not in livers from control rats. Treatment of rats with phenobarbital caused [NADP(+)]/[NADPH] to change in the direction of more oxidation, as calculated from measured concentrations of 6-phosphogluconate and ribulose 5-phosphate; however, the [NADP(+)]/[NADPH] ratio calculated from ;malic' enzyme was not changed. Additions of p-nitroanisole produced a reduction of NADP(+) as calculated from 6-phosphogluconate dehydrogenase activity, but did not alter the [NADP(+)]/[NADPH] ratio calculated from substrates assumed to be in equilibrium with ;malic' enzyme. Activities of both glucose 6-phosphate dehydrogenase and ;malic' enzyme were increased by phenobarbital treatment. NAD(+) became more reduced as a result of phenobarbital treatment; however, perfusion of livers with p-nitroanisole did not cause a change in the oxidation-reduction state of this nucleotide. Concentrations of adenine nucleotides in livers were not altered significantly by treatment of rats with phenobarbital; however, a significant decline in the [ATP]/[ADP] ratio occurred during mixed-function oxidation of p-nitroanisole in livers from phenobarbital-treated rats, but not in livers from normal rats. Perfusion of livers with two other substrates for mixed-function oxidation, hexobarbital and aminopyrine, produced an increase in the [NADP(+)]/[NADPH] ratio calculated from ;malic' enzyme. In contrast with livers perfused with p-nitroanisole, there was no significant change in adenine nucleotides in livers exposed to hexobarbital or aminopyrine. Addition of 2,4-dinitrophenol (25mum) to the perfusate containing aminopyrine decreased the [ATP]/[ADP] ratio and tended to prevent the oxidation of NADPH observed with aminopyrine alone. Thus in the presence of an uncoupler of oxidative phosphorylation, NADPH generation may exceed its utilization via mixed-function oxidation.


Influence of cations at the plasma membrane in controlling polysaccharide secretion from sycamore suspension cells. 1. Three soluble polysaccharides and a soluble protein containing hydroxyproline were secreted by sycamore suspension cultures. l-[1-(3)H]Fucose was incorporated solely into the fucose of fucoxyloglucan and l-[1-(14)C]arabinose mainly into the arabinose of arabino-galactan. [U-(14)C]Glucose was a general precursor for soluble protein and polysaccharides. 2. The steady-state rate of secretion of all the polymers was increased within seconds of adding various electrolytes and polyelectrolytes to the growth medium. The increased secretion was induced by cations at the outer surface of the plasma membrane. It was brought about by a stimulation of the normal mechanisms of cell-wall polysaccharide secretion. It was partly inhibited by anaerobiosis or sodium arsenate and was unaffected by temperature changes in the range 0-35 degrees C. 3. The precursor pool from which secretion was induced contained completely synthesized polysaccharides and was probably located in the Golgi-derived vesicles. The results indicated that the endoplasmic reticulum did not secrete polysaccharide directly to the cell exterior. 4. The various cations probably induced secretion by causing a depolarization of the negative electric potential of the cell surface, and this resulted in the fusion of vesicles with the plasma membrane. 5. Analogy with exocytosis and pinocytosis in various animal tissues suggested that the decreased surface potential brought about membrane fusion by causing an increase in plasma-membrane permeability to Ca(2+). 6. The results showed that the fusion of vesicles with the plasma membrane was rate-limiting and a potential control point. Auxin-stimulated cell-wall deposition could be a result of a stimulated influx of Ca(2+) causing vesicle fusion with the plasma membrane.


Evidence that fatty acid synthesis in the interscapular brown adipose tissue of cold-adapted rats is increased in vivo by insulin by mechanisms involving parallel activation of pyruvate dehydrogenase and acetyl-coenzyme A carboxylase. Plasma insulin concentrations in cold-adapted rats were altered acutely by administration of glucose or anti-insulin serum. Rates of fatty acid synthesis in interscapular brown adipose tissue were determined from the incorporation of 3H from 3H2O into tissue lipid. Rates of synthesis were greatly elevated after glucose administration and markedly decreased after injection with anti-insulin serum. Parallel changes in the initial activities of both acetyl-CoA carboxylase and pyruvate dehydrogenase were observed under these conditions, but no changes in total activities were evident. The results suggest that this tissue is an important site of fatty acid synthesis in the cold-adapted rat and that this feature of the tissue is sensitive to changes in plasma insulin concentrations.


Characterization and serology of the matrix protein from a nuclear-polyhedrosis virus of Trichoplusia ni before and after degradation by an endogenous proteinase. The intact matrix protein from a nuclear-polyhedrosis virus of the cabbage looper (Trichoplusia ni), isolated after inhibition of an endogenous serine-type proteinase, was further purified by molecular-sieve chromatography. The matrix protein was associated with carbohydrate moieties, and the carbohydrate content was determined for the two major peptides isolated after proteolysis by the endogenous proteinase. The association-dissociation interactions of the intact and proteinase-hydrolysed monomer units were characterized at high and low pH. At pH1.9, proteinase-degraded matrix protein dissociated into two different peptide fractions, FI and FII. Fraction FII, a single peptide of 9400 daltons, comprised one-third of the monomer unit of 28 000 daltons. At pH9.5, the degraded peptides were tightly associated in units equivalent to the intact monomer. These monomer equivalents associated to form a series of interconverting aggregates. The predominant aggregate sedimented at 11S and had a mol.wt greater than or equal to 200 000. Two non-cross-reacting antigens were present in the aggregate mixture. The presence of these two antigens does not reflect the presence of two different matrix proteins; rather, the expression of the antigens correlates with the degree of aggregation of the matrix protein.


Affinity chromatography of aminoacyl-transfer ribonucleic acid synthetases. Cognate transfer ribonucleic acid as a ligand. The use of tRNA affinity columns for the purification of aminoacyl-tRNA synthetases was investigated. A purification method for valyl-tRNA synthetase from Bacillus stearothermophilus is described that uses two affinity columns, one containing the pure cognate tRNA, and the other containing all tRNA species except the cognate tRNA. A method for the rapid preparation of the two columns was developed, which does not require prior isolation of cognate tRNA but makes use of the ability of the target synthetase to select its cognate tRNA. The usefulness of tRNA columns is compared with that of affinity columns derived from the aminoalkyladenylate reported in the preceding paper [Clarke & Knowles (1977) Biochem J. 167, 405-417].


Activation studies of the multiple forms of prochymosin (prorennin). Activation of the four separate components of prochymosin (prorennin) at pH 5.0 demonstrated that each zymogen was the precursor to an electrophoretically distinct chymosin (rennin). When the increase in milk-clotting activity with time was analysed, the mechanism of activation of unfractionated prochymosin, individual prochymosin components, and a mixture of the prochymosin fractions at pH 5.0 was shown to follow essentially autocatalytic kinetics. The activation of prochymosin C was completed in 70 h, whereas the other three fractions each required more than 110 h for complete activation under the same conditions. Intact prochymosin, the mixture of four components and prochymosin C were activated at similar rates. Interaction of the individual fractions during activation is suggested to explain the increased rate of the activation for the mixture. Comparison of autocatalytic activation of unfractionated prochymosin purified chromatographically at pH 6.7 and 5.7 demonstrated an increased rate of reaction of the zymogen prepared at the lower pH value. The possibility that prochymosin became susceptible to activation during preparation at pH values slightly below 6.0, as a result of changes in the proportion of the components or a conformational change and exposure of the active site, is discussed.


Electron-paramagnetic-resonance studies of leghaemoglobins from soya-bean and cowpea root nodules. Identification of nitrosyl-leghaemoglobin in crude leghaemoglobin preparations. 1. Leghaemoglobins from soya-bean (Glycine max) and cowpea (Vigna unguiculata) root nodules were purified by chromatography on DEAE-cellulose phosphate columns at pH8.0 and pH5.8, to avoid the relatively low pH (5.2) commonly used to purify these proteins. 2. E.p.r. (electron-paramagnetic-resonance) spectra of the fluoride, azide, hydroxide and cyanide complexes of these ferric leghaemoglobins were very similar to the spectra of the corresponding myoglobin derivatives, indicating that the immediate environment of the iron in leghaemoglobin and myoglobin is similar, an imidazole moiety of histidine being the proximal ligand to the haem iron [cf. Appleby, Blumberg, Peisach, Wittenberg & Wittenberg (1976) J. Biol. Chem.251, 6090-6096]. 3. E.p.r. spectra of the acid-metleghaemoglobins showed prominent high-spin features very near g=6 and g=2 and, unlike myoglobin, small low-spin absorptions near g=2.26, 2.72 and 3.14. The width of the g=6 absorption derivative at 10-20K was about 4-4.5mT, similar to the value for acid-methaemoglobin. In contrast, a recently published (Appleby et al., 1976) spectrum of acid-metleghaemoglobin a had less high-spin character and a much broader absorption derivative around g=6. 4. E.p.r. spectra of ferric leghaemoglobin nicotinate and imidazole complexes suggest that the low-spin absorption near g=3.14 can be attributed to a trace of ferric leghaemoglobin nicotinate, and those near g=2.26 and 2.72 are from an endogenous dihistidyl haemichrome. 5. A large e.p.r. signal at g=2 in all samples of crude leghaemoglobin was shown to be from nitrosyl-leghaemoglobin. A soya-bean sample contained 27+/-3% of the latter. A previously unidentified form of soya-bean ferrous leghaemoglobin a was shown to be its nitrosyl derivative. If this is not an artifact, and occurs in the root nodule, the nitrosyl radical may interfere with the function of leghaemoglobin.


Evidence for the role of vitamin C-6 as a cofactor of lysyl oxidase. At 24 h after injection of 16-day chick embryos with [C-3H]pyridoxine hydrochloride, some of this label appears in the epiphysial cartilage. Over 35% of this radioactivity appears in the form of [G-3H]pyridoxal and a further 30% as other vitamin B-6 compounds. Partial purification of lysyl oxidase from the labelled epiphysial cartilage reveals a single peak of radioactivity coinciding with a single peak of enzyme activity. On dialysis against phosphate-buffered saline, 75% of this radioactivity is found to be non-diffusible. After incubation with isonicotinic acid hydrazide, a carbonyl reagent that appears to inhibit lysyl oxidase both in vivo and in vitro, a further 70% of the radioactivity is lost, with a roughly corresponding loss of enzyme activity. It is suggested that a form of vitamin B-6 is required as a cofactor of lysyl oxidase, and that this may have important implications in terms of connective-tissue metabolism.


Pre-steady-state kinetic studies on cytoplasmic sheep liver aldehyde dehydrogenase. Stopped-flow experiments in which sheep liver cytoplasmic aldehyde dehydrogenase (EC 1.2.1.3) was rapidly mixed with NAD(+) and aldehyde showed a burst of NADH formation, followed by a slower steady-state turnover. The kinetic data obtained when the relative concentrations and orders of mixing of NAD(+) and propionaldehyde with the enzyme were varied were fitted to the following mechanism: [Formula: see text] where the release of NADH is slow. By monitoring the quenching of protein fluorescence on the binding of NAD(+), estimates of 2x10(5) litre.mol(-1).s(-1) and 2s(-1) were obtained for k(+1) and k(-1) respectively. Although k(+3) could be determined from the dependence of the burst rate constant on the concentration of propionaldehyde to be 11s(-1), k(+2) and k(-2) could not be determined uniquely, but could be related by the equation: (k(-2)+k(+3))/k(+2) =50x10(-6)mol.litre(-1). No significant isotope effect was observed when [1-(2)H]propionaldehyde was used as substrate. The burst rate constant was pH-dependent, with the greatest rate constants occurring at high pH. Similar data were obtained by using acetaldehyde, where for this substrate (k(-2)+k(+3))/k(+2)=2.3x10 (-3)mol.litre(-1) and k(+3) is 23s(-1). When [1,2,2,2-(2)H]acetaldehyde was used, no isotope effect was observed on k(+3), but there was a significant effect on k(+2) and k(-2). A burst of NADH production has also been observed with furfuraldehyde, trans-4-(NN-dimethylamino)cinnamaldehyde, formaldehyde, benzaldehyde, 4-(imidazol-2-ylazo)benzaldehyde, p-methoxybenzaldehyde and p-methylbenzaldehyde as substrates, but not with p-nitrobenzaldehyde.


A model for the allosteric regulation of pH-sensitive enzymes. 1. In an enzyme that has two independent binding sites for a ligand, any inhibitor that binds solely to the free enzyme will give rise to positive co-operativity. 2. A model is considered for the allosteric control of enzymes by effectors in which their effects are mediated by ligand-induced perturbations of the ionization constants of a group or groups involved in the binding of substrate to the active site. 3. The model described offers a plausible explanation for the observation that the sigmoidal initial-rate curves reported for some regulatory enzymes are not expressed at all pH values where the enzyme is catalytically active.


The reaction of Fe(III) myoglobin fluoride with reducing agents. The reaction of reducing agents with Fe(III) myoglobin fluoride from sperm whale was studied at alkaline pH values. The rate of reduction by dithionite was indistinguishable from the rate of ligand dissociation even when the values of the rate constants for both were only 1.0 X 10(-3)S-1 (at pH 10.6). Reduction by the reduced Methyl Viologen radical ion and reduced Safranine was faster than the rate of dissociation, providing evidence that these reductants can donate electrons to the iron centre via a pathway involving an (undetectable) liganded Fe(II) intermediate.


2-Deoxy-D-galactose, a substrate for the galactose-transport system of Escherichia coli. The following observations showed that 2-deoxy-D-galactose is a useful tool for the isolation and elucidation of the activity of one system for galactose uptake into Escherichia coli. 1. 2-Deoxygalactose, which is not a substrate for growth of E. coli, was transported into strains of the organism induced for galactose transport. 2. By using appropriate mutants it was shown that 2-deoxygalactose is a much better substrate for the galactose-transport system than for the methyl galactoside-transport system. This was confirmed by the results of mutual inhibition studies with substrates of each transport system. 3. The glucose-, arabinose- or lactose-transport systems did not effect significant transport of 2-deoxygalactose. 4. Like other substrates of the galactose-transport system, 2-deoxygalactose promoted effective proton uptake into de-energized suspensions of appropriate E. coli strains. 5. The S183 series of E. coli mutants were found to contain a constitutive galactose-transport system, if 2-deoxygalactose transport is used as one criterion for such activity.


Evidence for an electrogenic 3-deoxy-2-oxo-D-gluconate--proton co-transport driven by the protonmotive force in Escherichia coli K12. Evidence is presented indicating that the carrier-mediated uptake of 3-deoxy-2-oxo-D-gluconate and D-glucuronate in Escherichia coli K12 is driven by the deltapH and deltapsi components of the protonmotive force. 1. Approximately two protons enter the cells with each sugar molecule, independent of the sugar and the strain used. 2. In respiring cells, the magnitude of the pH gradient alone, as measured by distribution of [3H]acetate, appears to be insufficient to account for the chemical gradient of 3-deoxy-2-oxo-D-gluconate that is developed between pH 6.0 and 8.0. 3. If the external pH is varied between 5.5 and 8.0, 3-deoxy-2-oxo-D-gluconate uptake is gradually inhibited by valinomycin plus K+ ions, whereas the inhibition caused by nigericin is concomitantly relieved, thus reflecting the relative contribution of deltapH and deltapsi to the total protonmotive force at each external pH. 4. 3-Deoxy-2-oxo-D-gluconate can be transiently accumulated into isolated membrane vesicles in response to an artificially induced pH gradient. The process is stimulated when the membrane potential is collapsed by valinomycin in the presence of K+ ions.


Passive ion permeability of the chromaffin-granule membrane. 'Ghosts' of bovine chromaffin granules, in which the complex mixture of proteins and solutes normally found in the granule matrix is replaced by buffered sucrose are osmotically sensitive. They shrink when the osmotic pressure of the suspension medium is increased, and swell if solute entry is facilitated by the addition of ionophores. Swelling in the presence of ionophores has been used to investigate the passive ion permeability of these membranes. They have a very low permeability to K+ ions (of the order of 10(-10) cm/s); their permeability to protons, Na+ and choline ions is too low to be detected by these methods. Their passive permeability to anions decreases in the order: CNS- greater than I- greater than CCl3CO2- greater than Br- greater than Cl- greater than SO4(2)- greater than CH3CO2-, HCO3-, F-, PO4(3)- the permeability to hiocyanate being of the order of 10(-7) cm/s. Coupled proton and anion entry is extremely slow, except for weak acids. Fluoride, unexpectedly, also appears to enter rapidly when proton/K+ exchange is facilitated by nigericin. In the presence of K+ salts, nigericin, like valinomycin, induces lysis of intact granules, an effect that is not dependent on the presence of a permeant anion, but is dependent on the pH gradient across the membrane.


Lipid metabolism in spontaneously hypertensive rats (SHR). Plasma cholesterol was lower in spontaneously hypertensive rats (SHR), while plasma triglyceride and free fatty acid were increased in comparison with control normotensive Wistar-Kyoto (WK) rats. Correspondingly, [1-14C]-acetate incorporation into liver cholesterol was clearly decreased in SHR as compared with WK. As for lipogenic enzyme activities, glucose-6-phosphate dehydrogenase, malic enzyme and acetyl-CoA carboxylase in SHR were respectively decreased, increased and not significantly different, in comparison with WK rats. Liver cholesterol was rather low and cardiac triglyceride was slightly increased in SHR. Aortic cholesterol and triglyceride levels were not significantly different between SHR AND WK rats. Thus, SHR have an abnormality in lipid metabolism, especially in cholesterol synthesis, but the pathological implication of this in hypertension and related vascular lesions is not yet clear.


Assessment of combined oral theophylline and inhaled beta-adrenoceptor agonist bronchodilator therapy. 1. The bronchodilator effects of 500 microgram rimiterol by pressurized aerosol, 375 mg oral theophylline and both drugs in combination were compared in a randomized, placebo-controlled, double-blind trial in eight patients with chronic, partially reversible airways obstruction. 2. The four treatments were (i) oral theophylline, placebo aerosol (TP); (ii) oral placebo, rimiterol aerosol (PR); (iii) oral theophylline, rimiterol aerosol (TR) and; (iv) oral placebo, placebo aerosol (PP). The aerosol was administered 2 h after the oral treatment. 3. Significant bronchodilatation (% FEV1 change from control) compared to PP occurred with TP from 60 to 480 min and with TR from 60 to 300 min, whereas with PR only for 45 min (P less than 0.05). 4. The mean, peak % FEV1 increases from control were 51.8% at 125 min, 31.7% at 125 min, 26.1% at 210 min and 0.9% at 30 min for TR, PR, TP and PP respectively. 5. At 125 min (5 min after aerosol inhalation) the mean % FEV1 change from control with TR (51.8%) Was significantly greater than with PR (31.7%), TP (22.2%) (P less than 0.05) and PP (-2.4%) (P less than 0.01). 6. The mean, peak plasma theophylline levels were 10.19 microgram/ml at 120 min and 9.98 microgram/ml at 180 min with TR and TP respectively. Theophylline half-life ranged between 4.3 and 12.5 h (mean +/- s.e. mean, 8.0 +/- 0.8 h). 7. Additive bronchodilatation was produced when rimiterol was administered with theophylline at a time when therapeutic plasma theophylline levels were achieved.


Clazepam: pharmacokinetics and effects on performance. 1. The effects of clazepam, a new benzodiazepine (30 mg orally) on performance tests and the cardiovascular system have been compared to those of chlordiazepoxide (30 mg orally) and a placebo in a double-blind trial involving six healthy volunteers. Simultaneously, the pharmacokinetics of clazepam were investigated. 2. While clazepam itself could be detected neither in plasma nor in urine, it gave rise to two plasma metabolites, the former, an alcoholic derivative with a short half-life, and the second, desmethyldiazepam, with a long half-life. These two metabolites and oxazepam were excreted in urine and, within the 24 h period following drug intake, accounted for 73% of the ingested dose. 3. Seven hours after its administration, clazepam slightly improved performance and reduced anxiety. The kinetics of these effects and the metabolic data suggest that clazepam acts mainly through the formation of desmethyldiazepam. However, owing to the low blood levels of this metabolite, the activity of clazepam was very moderate.


Studies of cardioselectivity and partial agonist activity in beta-adrenoceptor blockade comparing effects on heart rate and peak expiratory flow rate during exercise. 1 The effects of beta-adrenoceptor antagonists given in single doses by oral or intravenous routes were examined in two double-blind controlled studies performed in healthy volunteers. Heart rate and peak expiratory flow rate (PEFR) were measured at rest and during standardized exercise. 2 Propranolol 80 mg and metoprolol 100 mg orally tended to reduce, and propranolol and metoprolol 0.2 mg/kg intravenously did reduce the physiological increase in PEFR during exercise; oxprenolol 80 mg orally and 0.2 mg/kg intravenously did not. Practolol 200 mg orally reduced this increase, but practolol 1 mg/kg intravenously did not. 3 In a third study of similar design, pindolol 0.05 mg/kg intravenously did not affect exercise-induced increase in PEFR. 4 Heart rate during exercise was reduced to a comparable extent at different times by all the active treatments. 5 Oxprenolol and pindolol share with practolol the property of partial agonist activity, which might contribute to their apparent lack of effect on airways resistance. A further possibility is that alpha-adrenoceptor blockade helps to maintain exercise-induced increase in PEFR.


[Salicylate poisoning. Determination of the free fraction using the ultrafiltration method]. Seventeen infants under one year of age admitted to the Emergency Service of the General Hospital of the Medical Center La Raza during the year 1976 were included in this study with the diagnosis of salicylate poisoning. Determination of plasma salicylate by the ultrafiltrate method was practiced to all patients. A direct relationship between total plasmatic salicylate and its free fraction was found together with an inverse proportion between percentage of total free--salicylate and plasma pH and a lineal correlation between plasma free--salicylate and salicylate obtained in spinal fluid. It is concluded that determination of the free fraction of plasma salicylate is an easy diagnostic method for the better evaluation of salicylate acid poisoning in the infant.


The effects of chronic drug administration on hepatic enzyme induction and folate metabolism. 1 Patients on prolonged treatment with anticonvulsant and phenothiazine drugs exhibited lower than normal concentrations of folate in serum and erythrocytes, and showed increased urinary FIGLU excretion after histidine loading; urinary excretion of D-glucaric acid was also increased suggesting induction of the hepatic microsomal enzymes. 2 Folate deficiency by enzyme-inducing drugs was seen to be determined more by the duration of therapy than by the nature of the drugs. Excretion of FIGLU was increased by 70% by 2-5 years of treatment with anticonvulsant, phenothiazine or tricyclic drugs, and by 200% after 6 or more years. 3 Hepatic microsomal enzyme induction, as measured by D-glucaric acid excretion, was greatest after 2-5 years treatment. 4 It is suggested that the increased requirements for folate, resulting from microsomal enzyme induction, lead to folate deficiency and this subsequently limits enzyme induction, leading to adverse drug side-affects. 5 The dietary folate of hospitalized patients would seem to be generally inadequate for patients on long term treatment with enzyme-inducing drugs.


Thermodynamics of the denaturation of pepsinogen by urea. The denaturation of swine pepsinogen has been studied as a function of urea concentration, pH, and temperature. The unfolding of the protein by urea has been found to be fully reversible under different conditions of pH, temperature, and denaturant concentration. Kinetic experiments have shown that the transition shows two-state behavior at 25 degrees C in the pH range 6-8 covered in this study. Analysis of the  equilibrium data obtained at 25 degrees C according to Tanford (Tanford, C. (1970), Adv. Protein Chem. 24, 1) and Pace (Pace, N.C. (1975), Crit. Rev. Biochem. 3, 1) leads to the conclusion that the free energy of stabilization of native pepsinogen, relative to the denatured state, under physiological conditions, is only 6-12 kcal mol-1. The temperature dependence of the equilibrium constant for the unfolding of pepsinogen by urea in the range 20-50 degrees C at pH 8.0 can be described by assigning the following values of thermodynamic parameters for the denaturation at 25 degrees C: deltaH=31.5 kcal mol-1; deltaS=105 cal deg-1 mol-1; and deltaCp=5215 cal deg-1 mol-1.


Arginine decarboxylase from Escherichia coli B: mechanism of dissociation from the decamer to the dimer. The mechanism by which arginine decarboxylase dissociates from a decamer to a dimer has been examined by allowing a sulfhydryl group, available in the dimer but not the decamer, to react with 5,5'-dithiobis(2-nitrobenzoic acid). Initial rates of dissociation were obtained by following the resulting increase in absorbance at 412 nm in a stopped-flow spectrophotometer. The rate of dissociation increases linearly with the protein concentration and reaches a maximum as a function of the concentrations of 5,5'-dithiobis(2-nitrobenzoic acid), Na+, and 1/[H+]. Experiments in which the rate of dissociation was measured while one reagent was varied at fixed levels of a second indicate that dissociation requires three events: binding of one Na+ ion, dissociation of one proton, and the irreversible dissociation of subunits, in that order. The results also show that the decamer dissociates in stages rather than all at once. The activation energy for the overall process is 16 kcal/mol.


Mechanisms and rate equations for dissociating systems. The results presented in the previous paper (Boeker, E.A. (1978), Biochemistry 17 (preceding paper in this issue) indicate that the dissociation of the decamer of arginine decarboxylase of Escherichia coli B is enhanced by Na+ and retarded by H+. In this system, substances which increase the rate of dissociation can be treated kinetically either as substrates or activators, and substances which retard dissociation can be treated as products or inhibitors. In addition, the events needed for dissociation can occur in an ordered or a random sequence, and the dissociation itself, from a decamer to five dimers, can be a sequential or a concerted process. In order to provide a framework for the experimental results, mechanisms for the dissociation of arginine decarboxylase that take all of these factors into account are described. In addition, it is shown that the usual methods of steady-state kinetics can be applied to these systems when true initial rates are measured; rate equations are presented for each mechanism. The results can be used for any dissociating of three or more subunits and will describe the dissociation of a dimer under certain conditions.


Transport in C4 mesophyll chloroplasts: evidence for an exchange of inorganic phosphate and phosphoenolpyruvate. 1. Mesophyll chloroplasts of the C4 plant Digitaria sanguinalis contain endogenous phosphoenolpyruvate which appears to distribute across the envelope according to the existing pH gradient. The phosphoenolpyruvate remaining in the stroma can be rapidly released by external inorganic phosphate or 3-phosphoglycerate while external pyruvate did not affect the distribution. 2. Phosphoenolpyruvate (PEP) was a competitive inhibitor (Ki (PEP) = 450 micrometer) of 32Pi uptake (Km(Pi)=200 micrometer) by chloroplasts in the dark and also reduced the steady-state internal concentration of 32Pi, which is consistent with phosphate and phosphoenolpyruvate sharing a common carrier. 3. Phosphoenolpyruvate formation by chloroplasts in the light in the presence of pyruvate but in the absence of inorganic phosphate was slow and the concentration ratio of phosphoenolpyruvate (internal/external) was high. Addition of 0.1 mM phosphate induced a high rate of phosphoenolpyruvate formation and the concentration ratio (internal/external) decreased 15-fold. It is proposed that external phosphate is required both for phosphoenolpyruvate formation and efflux from the chloroplast.


Pulse fluorimetry study of energy transfers between tryptophan residues and NADPH in beef liver glutamate dehydrogenase complexes. A method is proposed to determine the rates of singlet energy transfers in an array of chromophores containing a finite number of donors and fluorescent acceptors. This method is based on measurements of transfer efficiency coupled with pulse fluorimetry. Three classes of donors can be distinguished which differ in their energy transfer rate. The rates of the first, the second and the third class are respectively greater than, of the order of, and smaller than the emission rate. The method is applied to the study of the energy transfers from tryptophan residues to NADPH, in ternary and quaternary glutamate dehydrogenase complexes. Practically, all these tryptophan residues belong to the first class. They can be divided into two subclasses having different transfer rate values. The distance between these residues and the NADPH site are of the order of 2.5 nm. In addition, the ligand binding induces a protein conformation change, leading to a fluorescence quenching of the tryptophanyl emission.


Effect of haemolysis on the hexose monophosphate pathway in normal and in glucose-6-phosphate dehydrogenase-deficient erythrocytes. The hexose monophosphate pathway of human glucose-6-phosphate dehydrogenase (EC 1.1.1.49) - deficient erythrocytes is under a severe and unexplained restraint (Gaetani, G.D., Parker, J.C. and Kirkman, H.N. (1974) Proc. Natl. Acad. Sci. U.S. 71, 3584-3587). In this study the hexose monophosphate pathway activity and the NADPH level of normal and glucose-6-phosphate dehydrogenase-deficient erythrocytes were measured soon after haemolysis. The results indicate a prompt increase in 14CO2 evolution and a rise in MADPH levels. Since, in this study, the concentration of the haemolysate is comparable to that of intact erythrocytes, the relief of the restraint on glucose-6-phosphate dehydrogenase through dilution-dependent dissociation from inactivator or inhibitor is excluded. The possibility that the intracellular restraint may result from compartmentalization of glucose-6-phosphate dehydrogenase and substrates or from properties of the intact membrane of the erythrocytes is suggested.


Proton electrochemical gradient and phosphate potential in submitochondrial particles. The aerobic uptake of inorganic ions, such as 86Rb+  or 125I-, by submitochondrial particles, is about one order of magnitude lower than the uptake of organic ions, such as acridines or 8-anilino-1-naphthalene sulphonate. The values of deltapH, the transmembrane pH differential, and deltapsi, the transmembrane membrane potential are between 60 and 100 mV when calculated on the inorganic ions and between 150 and 240 mV when calculated on the organic ions. The discrepancy between the deltapH and deltapsi values from organic and inorganic ions is large at high but not at low ion/protein ratios. 2. In the absence of weak bases and strong acids the values of deltamuH, the proton electrochemical potential difference, are close to 100 mV and the magnitude of deltapH and deltapsi are similar. Weak bases decrease deltapH and enhance deltapsi. Strong acids decrease deltapsi and enhance deltapH. Interchangeability of deltapH with deltapsi occurs at low concentrations of weak bases and strong acids. High concentrations of weak bases and strong acids cause depression of deltamuH. 3. Concentrations of weak bases capable of abolishing deltapH, do not affect ATP synthesis. Concentrations of strong acids capable of abolishing deltapsi affect only slightly ATP synthesis. Concentrations of weak bases and strong acids capable of causing a decline of deltapH + deltapsi inhibit ATP synthesis. 4. Depression of deltamuH is paralleled by inhibition of ATP synthesis and decline of deltaGp, the phosphate potential. Abolition of ATP synthesis occurs only when deltamuH is below 20 mV. The deltaGp/deltamuH ratio increases hyperbolically with the decrease of deltamuH.


Steady-state kinetics of electron transfer through cytochrome chain of uncoupled submitochondrial particles. II. Influence of pH on kinetics of electron transfer. pH Dependences of steady-state kinetic parameters of cytochrome chains of submitochondrial particles have been studies. It has been shown that the lifetimes of activated states (tau) of the pairs of cytochromes b leads to c1 and a leads to a3 have different pH dependences; those for the c1 leads to c and c leads to a cytochrome pairs being similar. The rate constants for the non-activated state of the respiratory chains decreased for the b leads to c1 pair and increased for the a leads to a3 pair when the pH value was increased. The values of pK calculated from these dependences for the pairs b leads to c1 and a leads to a3 were 7.2 and 8.9, respectively. It has been supposed that the ratio of activated to non-activated electron carriers may be controlled by the local pH value in the mitochondrial membrane, the latter being dependent upon the rate of electron transfer. The kinetic model based on this assumption allows one to explain the experimental dependences on pH of the rate constants for cytochromes b leads to c, and a leads to a3. The values of the diffusion rate constants for H+ and OH- ions in the mitochondrial membrane estimated from these kinetic data obtained in this study were 10(4)--10(5) s-1 and 10(2)--10(3) s-1, respectively.


Some kinetic aspects of the mechanism of hydrolysis of phosphoric acid esters by nonspecific acid phosphatase from Schizosaccharomyces pombe. 1. The kinetics of the hydrolysis of nitrophenylphosphate by nonspecific acid phosphatase (orthophosphoric-monoester phosphohydrolase (acid optimum), EC 3.1.3.2.) from Schizosaccharomices pombe was studied. 2. The kinetic parameters, Km and V, were determined as well as the inhibition constants, K1, for the inhibitors, phosphate and fluoride, as a function of pH. 3. The results, interpreted according to the theories of Dixon and Waley indicated the presence of three ionizable groups on the enzyme itself and one on the enzyme-substrate complex. 4. A model of the hydrolysis of phosphoric acid monoesters by the S. pombe acid phosphatase is proposed based on the ionization state of the reactants and on the results of the inhibition by the competitive inhibitors.


Subunit structure and activity of glyceraldehyde-3-phosphate dehydrogenase from spinach chloroplasts. Glyceraldehyde-phosphate dehydrogenase (D-glyceraldehyde-3-phosphate : NADP+ oxidoreductase (phosphorylating), EC 1.2.1.13) from spinach chloroplasts is a polymeric protein of approx. 600,000 daltons and sodium dodecyl sulphate gel electrophoresis shows that it consists of two subunits of molecular weight 43,000 and 37,000. Comparison of amino acid analyses and tryptic peptide maps indicates that the two subunits have a different primary structure. The native enzyme contains 0.5 mol of NADP+ and 0.5 mol of NAD+ per protomer of 80,000 daltons, no reduced pyridine nucleotides have been detected. Almost complete inactivation is obtained by reaction of two cysteinyl residues per 80,000 daltons with tetrathionate or iodo[14C2]acetic acid; since the same amount of radioactivity is incorporated in the two subunits it is likely that they are both essential for the catalytic activity. Charcoal stripping of native glyceraldehyde-phosphate dehydrogenase produces an apoprotein which still retains most of the enzymatic activity but, unlike the holoenzyme, is gradually inactivated by storage at 4 degrees C and does not react with iodoacetate under the same conditions in which the holoenzyme is completely inactivated.


pH dependence of the kinetic parameters of L-asparaginase. The concentration dependence of the rate of hydrolysis of L-asparagine by Escherichia coli L-asparaginase (L-asparagine amidohydrolase, EC 3.5.1.1) has been measured over the range pH 4.5 to pH 9.1 by a direct spectrophotometric assay at 220 nm and by a coupled assay utilizing glutamate dehydrogenase to detect the ammonia produced. The velocity of the hydrolysis reaction at saturating levels of substrate is independent of pH over this interval. The plot of V/km over the same interval is bell-shaped, being dependent on pKa values of 6.58 and 8.69. The higher pKa is attributed to the amino group of asparagine. The lower pKa is associated with the enzyme active site and is probably due to an imidazole group.


Purification and properties of asparagine synthetase from rat liver. Asparagine synthetase (L-aspartate:ammonia ligase (AMP-forming, EC 6.3.1.1) activity in rat liver increased when the animals were put on a low casein diet. The enzyme was purified about 280-fold from the supernatant of rat liver homogenate by a procedure comprising ammonium sulfate fractionation. DEAE-Sepharose column chromatography, and Sephadex G-100 gel filtration. The optimal pH of the enzyme was in the range 7.4-7.6 with glutamine as an amide donor. The molecular weight was estimated to be approximately 110,000 by gel filtration. Chloride ion was required for the enzyme activity. The apparent Km values for L-aspartate, L-glutamine, ammonium chloride, ATP, and Cl- were calculated to be 0.76, 4.3, 10, 0.14, and 1.7 mM, respectively. The activity was inhibited by L-asparagine, nucleoside triphosphates except ATP, and sulfhydryl reagents. It has been observed that the properties of asparagine synthetase from rat liver are not so different from those of tumors such as Novikoff hepatoma and RADA 1.


Interaction of steroids with D-amino acid oxidase. 1. Progesterone inhibited D-amino acid oxidase (D-amino acid : O2 oxidoreductase (deaminating), EC 1.4.3.3) in competition with its substrate, D-alanine. Binding of progesterone brought about the increase in both fluorescence intensity and fluorescence polarization of FAD, which indicates that the environment surrounding FAD chromophore is modified due to a conformational change in the apoenzyme. 2. Ethinyl estradiol, testosterone, testosterone propionate, corticosterone and aldosterone also inhibited the enzyme slightly in the same manner. Their binding also produced a slight increase in FAD fluorescence without decreasing the fluorescence polarization. 3. Cholesterol did not inhibit the enzyme, though it increased the fluorescence polarization of FAD. This indicates the binding of cholesterol with the enzyme at a site other than the substrate binding site.


Enzymes of the gamma-glutamyl cycle in 'aging' WI-38 fibroblasts and in HeLa S3 cells. gamma-Glutamyltransferase ((5-glutamyl)-peptide:amino-acid 5-glutamyltransferase, EC 2.3.2.2) activity of WI-38 fibroblasts decreased only slightly in relation to a constant amount of cell-associated protein as the cells were carried in culture serially from middle to late passage numbers leading toward senescence, e.g., from population doubling level 27 through 41. Also, when the enzyme activity was expressed on the basis of a unit number of cells or unit amount of DNA, little change occurred over that range of PDLs. As the culture approached 'phase-out', the transferase activity rose sharply regardless of how the activity was expressed. The possibility is considered that the large increase in activity could be a reflection of a significant increase in size of cells and therefore changes in the membranes where the transferase is located. The occurrence of other enzymes of the 'gamma-glutamyl cycle' in WI-38 and HeLa S3 cells also was demonstrated. These included gamma-glutamylcyclotransferase ((gamma-L-glutamyl)-L-amino-acid gamma-glutamyltransferase (cyclizing), EC 2.3.2.4) and 5-oxoprolinase, whose activities showed no large increase comparable to that of the gamma-glutamyltransferase, as the culture approached 'phase-out'.


Tyrosine aminotransferase from chick liver. Heat activation and cold inactivation of the enzyme. The reversible heat activation and cold inactivation of tyrosine aminotransferase (L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5) of chick liver were investigated. When the enzyme obtained by gel filtration was preincubated at 37 degrees C for 10 min with 50 micrometer pyridoxal 5'-phosphate (pyridoxal-5'-P), a 7-fold increase in enzyme activity was detected. When the preincubated enzyme was cooled to 0 degrees C, it lost its activity. Furthermore, the dramatic cyclical changes in enzyme activity occurred by sequential heating at 37 degrees C and cooling to 0 degrees C of the enzyme, in the presence of pyridoxal-5'-P, over shorter periods of time without loss of enzyme activity. However, when alpha-ketoglutarate was added to the enzyme during cold exposure, no further decrease in activity was observed. This protective effect was seen at a concentration of 5 muM.


Synthesis of acyl phosphatidylglycerol from phosphatidylglycerol in Escherichia coli K-12. Evidence for the participation of detergent-resistant phospholipase A and heat-labile membrane-bound factor(s). The conversion of phosphatidylglycerol to acyl phosphatidylglycerol by extracts of Escherichia coli K-12 strains was examined under various conditions. The maximum rate of conversion was observed at pH 7.2 in the presence of 50% (v/v) diethyl ether and 10 mM CaCl2. This conversion was found to involve two sequential reactions: (1) The formation of 2-acyl glycerophosphoglycerol and 2-acyl glycerophosphoethanolamine from phosphatidylglycerol and phosphatidylethanolamine, respectively, by detergent-resistant phospholipase A in the presence of Ca2+ and (2) transfer of the acyl group of 2-acyl lysophospholipid to phosphatidylglycerol by a heat-labile factor(s) in the presence of diethyl ether. Neither fatty, acid acyl-CoA nor 1-acyl lysophospholipid could act as an acyl donor for phosphatidylglycerol. The heat-labile factor(s) was found in both the inner membrane and supernatant fractions.