[Geriatric change of thyroid function and thyroid diseases (author's transl)]. The geriatric changes of thyroid function in healthy individuals are relatively low; therefore it is not necessary to take it into consideration for routine diagnostic work. Thyroid diseases show an increase with age and also a change of the clinical picture. Therefore, and because of being superimposed by symptoms of simulatneous second disease, it is necessary to start with the specific diagnostic earlier than in younger patients.


Functional changes of the aging rat retina in relation to the modifications of the ERG components. the intact eye of Wistar rat was stimulated with continual periodic light signals in the range of 0,001-500 lux and from 0,01 cps. up to the fusionfrequency. Using square-wave light stimuli of the frequency range from 0,01 to 0,1 cps. and intensity diapason of 0,1-1,0 lux the scotopic electroretinogram (ERG) consists of the following waves: b, b-negative, c, d, d-positive, respectively. At the beginning of the light sensitivity range, that is near above the threshold, on one part and over a stimulus intensity of 10 lux, on the other the ERG becomes more simple and looks appr. like a direct current (DC) response. Along with aging the ERG undergoes changing. The light sensitivity of the eye proved to be decreased, especially in the short wave range of the spectrum. Thus the ERG threshold becomes increased. The DC components are less apparent. The fast elements of high amplitudes are also missing. The slope of the frontal and descending part of the wave b gets lower. The fusion-frequency is lower with old animals as well. The spontaneous physiological biopotential noise level is significantly higher and the synchronity of elements participating in generating the ERG wave is less. Additionally a considerable great slowing-down of the adaptation processes were observed. Using light signals of different wave forms, it may be established, that differentiating ability of the retina declines more rapidly as aging advances than that of its light sensitivity.


[Assessment of the biological age in the animal-experiment (author's transl)]. Experimental investigations of internal and external factors presumably influencing the aging process require an objective assessment of the biological age or vitality respectively by means of as many age parameters as possible. Using the rat, a valuable test animal in experimental gerontology, whose life expectancy of about 40 month allows longitudinal studies, a standard test programm for the estimation of the biological age has been developed. The age parameters used originate from investigations of 1. the tail tendon collagen, 2. the skin, 3. the aorta, 4. the ECG, 5. the lipofuscin content of brain and heart, 6. the tissue respiration of various organs, 7, the motor activity and 8. learning and memory. Using the above-mentioned age parameters a statistical measure for the biological age will be calculated by means of multivariate analysis and will allow the comparison of differeent age-and experimental-groups.


[Investigation of memory in experimental gerontology (author's transl)]. The possible transfer of learning performance by proteins and ribonucleic acids was studied. 140 male Sprague-Dawley rats aged 3 months and 68 aged 20 months were used. Proteins and ribonucleic acids were isolated from the brains of trained and untrained rats aged 3 months. The difference in learning performance was tested and the incorporation of the above-mentioned substances into the hippo-campus and the residual brain in the two age-groups was measured using radioactive labelled material. A specific transfer of learned information-contents on the molecular level was found only after transfer of proteins in both young and old rats; the results of the training are well correlated with those of the incorporation. The two age-groups differ especially with regard to the learning performance, expressed in the error number. In th older group the error number is significantly lower in contrast to the learning time, that is slightly shorter in the younger group. This can be explained by the differences between the incorporation of brain proteins of trained animals into animals of different age, as well as by the investigations of some authors, who distinguished between different modes of learning. The lower incorporation of labelled substance into the brains of old animals is remarkable; the conclusion is a lower turnover of these substances in the brain of old animals, especially of the ribonucleic-acids. Nevertheless the learning performance of complex information-contents is not impaired.


[Paranoid syndromes in the involution (author's transl)]. Conditions of outbreak and chronification of paranoid syndromes, including the existence of an "axial syndrome" and behaviour theories are hypothetically summarized. The individual characteristics of patients with the first paranoid symptoms during involution appear to depend mainly on three factors: the theme of the delusion seems to be connected with the age at the onset, in more than half of the male patients exogenous psychoorganic symptoms were observed, and in females however predominantly manic-depressive syndroms could be found.


[Genetic aspects of aging (author's transl)]. The experimental results indicating a primary genetic cause of aging and some diseases of the old age (cancer, arteriosclerosis, immune deficiency, autoimmune diseases) are summarized under two aspects: 1) The genetic influence is determined during the differentiation and development phase of the organism, whereby the direct or indirect (pleiotropic effect) selection of genes of aging, or the missing selection of genes which are acting against aging come into consideration. 2) The dicisive gene alterations take place by spontaneous and/or induced somatic mutations.


[Study of age and sex dependance in renal clearances with radioisotopes (author's transl)]. In 85 patients between 15 and 95 years of age (40 male patients and 45 females) without any signs of renal disease (concentration of serum creatinine below 1,4 mg/100ml, normal diastolic blood pressure and normal urine analysis) a highly significant negative correlation was found between glomerular filtration rate (GFR, determined by 51Cr-EDTA - slope-clearance) and renal plasma flow (RPF, determined by 131J-oJHS-iodinehippuricacid-totalclearance) on one side and age on the other. Beginning with a basic value of 160 ml in males and 144 ml in females for GFR, the average decrease per year was 1,2 ml/1,0 ml respectively. The basis value of RPF was 854 ml for males and 673 ml for females, the decrease per year was 5,4 ml in men and 2,9 ml in women. The importance of physiological diminution of clearance values in elderly patients and its consequences for therapy are discussed. The more exact and methodically simpler 51Cr-EDTA-slope-clearance without urine collection should be used instead of the somewhat inaccurate determination of endogenous creatinine clearance especially in older patients.


[The significance of experimental gerontology for clinical geriatrics (author's transl)]. Aging is a physiological process. The experimental gerontology is substantially a purely theoretical science. In the future, however, it will attain increasingly more significance for many fields of medicine. After presenting a survey covering the most important theories of aging it is shortly entered into the efforts to establish a mathematical model of multicellular aging (Beier, Brehme and Wiegel 1973). Furthermore an introduction is given into a longitudinal program (3 years) of the own experimental-gerontological research using about 1000 Sprague-Dawley rats and age parameters. The mathematical evaluation of the results shall contribute to come to more exact and objective statements  about age and vitality. The significance of the theoretical-experimental gerontology lies mainly in its efforts to study the fundamental conditions and the possibilities for a longer maintenance of vitality by systematic measures and to reduce or retard the susceptibility to the socalled age-diseases.


[A serogenetic approach to the study of Alzheimer's disease (author's transl)]. The analysis of 15 hereditary controlled blood characteristics in 57 Alzheimer-patients revealed abnormalities in the distribution of ABO-blood-groups and phenotypes in the third component of complement system. These data indicate that the phenogenesis of the Alzheimer syndrome is multiconditional and is obviously influenced by selective processes of immuno-genetic factors. This selective vulnerability offers a lead into the elucidation of amyloid deposition in Alzheimer's disease.


[The effect of prednisolone on the development of the galactosamine hepatitis of young and old rats (author's transl)]. The present work reports on kinetic and morphological studies of one hundred female albino rats after the administration of galactosamine and galactosamine and prednisolone. The results demonstrate a significant higher increase of the serum transaminasess got and gpt in the older than in the younger rats as well as a protecting effect of prenisolone against galactosamine produced disturbances. In the thirty months old rats the protection against morphological and biochemical disturbances was only demonstrable for the first twelve hours after the administration of galactosamine.


[Age-dependent changes of hypophysis-thyroid - regulation (author's transl)]. In health men and women different age total thyroxine, free thyroxine-binding-capacity, total triiodothyronine as well as TSH in serum before and after intravenous application of 500 mcg synthetic thyrothropine-releasing-hormone (TRH) were controlled. The investigations have shown: 1. With increasing age total thyroxine level in serum does not change. 2. With increasing age free thyroxine-binding-capacity in serum does not change. 3. With increasing age in men and women a significant decrease of total triiodothyronine in serum is to be measured. 4. Basal TSH serum levels do not change with increasing age. On the other hand in men and women with increasing age significant decreased TSH increments after TRH application were measured. The investigations have shown, that with increasing age the hypothalamus-hypophysial-thyroid-axis is shifting to a lower regulation level.


[Problemss of tending to chronicity of diseases in geriatrics (author's transl)]. The most important alterations of the old age are mentioned. They have a great influence on the behaviour of the elderly in a hospital. Charactersitic behaviour patterns at admission, during hospitalization and at dismission are pointed out. Multimorbidity should not cause a thoughtless and highly technical work-up. Rehabilitation measures in order to keep the patient in bed as short as possible are important. For this reason the nursing staff should have a good knowledge of activating care. Pharmacogherapy, intensive care, preoperative and postoperative care are mentioned.


[Medical treatment and rehabilitation measures for the elderly--discussion of the financial problems involved (author's transl)]. The National Pension Insurance and Health Insurance Schemes up to now share the expenses of health insurance for the elderly. The shares to be carried by each body are again and again subject to political discussion. Since nursing home care is up to now not accepted as being an integral part of health care, the social welfare system is forced to cover the expenses involved to a continuously increasing degree. While it can be shown, that health insurance for the elderly has greatly improved since its introduction in 1941, there nevertheless remain elements of discrimination of those no longer belonging to the age group with access to gainful employment. Discussing different measures of solution in the context of existing insurance systems, the National Pension Insurance would seem to be the body best suited to take over the whole responsibility of financing health insurance measures for the elderly. Another alternative would be to let the pensioneers themselves come up for the costs of their health insurance, or the decision may be taken to establish a new insurance system directed at covering the risks of long term illness for all age groups.


[Clinical use of a thermal method for measuring peripheral blood flow according to A.M. Baptista (author's transl)]. Measurement of peripheral circulation according to Baptista is discussed and its applicability in clinical work demonstrated. Examples are given showing changes following peroral treatment with inositol niacinate and intra-arterial injection of carbon dioxide.


[Peculiarities of unconditioned and conditioned reflex stimuli effects on secretory function of gastric glands in elderly and senile people (author's transl)]. For understanding age peculiarities of gastric secretory function in aging.tory function in aging.tory function regulation, the investigation of nervous influences on gastric secretion is of importance. With this end in view the unconditioned reflex stimulus- the tube with rubber balloon, containing 10 ml of water and conditioned reflex stimulus - food stimulus were employed. The fractional gastric intubation was carried out. The gastric secretion in response to mechanical stimulus was investigated in 125 persons aged 60-89 and in 40 persons aged 20-25 (control group). In response to conditioned reflex stimulus it was studied in 30 persons aged 60-89 and 10 persons aged 20-35 (control group). With aging the response of gastric glands to unconditioned and conditioned stimuli was found to decrease. The amount of secretion, hydrochloric acid, pepsin, and gastromuco-protein were decreased, the secretory effect being more slowly developed, the torpid secretion type being observed. The above facts testify to changes of nervous regulation of gastric secre


[Incorporation of 14-C-Glycine during galactosamine hepatitis of young and old rats (author's transl)a*]. The present work reports on incorporation of 14-Cglycine in the proteins of three liver fractions after the application of D-Galactosamine and D-Galactosamine + Prednisolone. 164 females albino rats were used in the experiments. The results demonstrate a higher rate of glycine incorporation in thirty months than in six weeks old animals. There is also a different age depending effect of prednisolone. The results are discussed in the light of reports from the literature.ports from the literature.


[The correlations between aging and drug effects (author's transl)]. Four examples (Methamphetamine, Testosterone, Caffeine, Cysteamine) have demonstrated that the response of the organism to a drug is primarily dependent upon the functional status of the organ concerned. If this functional status changes with age, then accordingly the reaction to the drug also changes. If, however, one alters the functional status of an organ in the elderly organism, e.g. inducing increased production of DNA in the liver by partial hepatectomy, the reaction of the organ now follows a pattern comparable to the juvenile organism, rather than being dependent on chronological age.


[Transitional phases in human development (author's transl)]. Transitional phases in the course of Human Development which divide the course of development into different steps, have been searched far from the old. These transitional phases are very often seen to be at least initiated by physical resp. biological changes and accompanied by psychological or mental changes. The results of the Life-span-Psychology and especially the findings of the biographical studies of our Psychological Institue, which were started in the Fifties, shows that there are Transitional phases which neither related to biological change nor to role change nor to the change from the one decade of life to the other one. Much more important are very personal experiences which very often lead to a reorientation. - These findings are in agreement with cognitive theory of personality, according to which human behavior is dependent more on the situation as perceived, than on the stimulus-pattern contigent with this situation. Therefore the study of these situational concepts of individual is relevant for the Life-span-Psychology and specially for the analysis of transitional phases.


[Biological oriented research in gerontopsychiatrie (author's transl)]. Possible biological oriented research in geronto-psychiatry is discussed in relation to dementias. The discrimination between the various forms as well as against normal aging is dealt with. Reference is given to results of studies correlating clinical, neuropathological and neurophysiological date.


[Multidimensional pharmacopsychiatry in gerontopsychiatry: studies on the therapy with tricyclic antidepressant drugs (author's transl)]. A Concept for the multidimensional assessment and correlation of serum level and outcome of therapy with psychomopharmaca with chemical, psychological, psychophysiological, electroencephalographical and clinical methods is shown. It is possible by this method to correlate clinical outcome to serum level and effect of the drug and to objectivate the efficacy of the pharmacon. Applications in Gerontopsychiatry are discussed.


[Patients and their diseases in a geriatric hospital (author's transl)]. Report on patients and their problems of a hospital of chronic diseases. Geriatric departments, part of clinics of acute diseases should treat not only patients without real chance for rehabilitation or discharge. Most of the diseases of elder persons are such of the arterial system, especially of the cerebral and coronary vessels. Although patients suffered of partial or complete dementia and had to stay long in the hospital visitors came more often. Generally must be postulated, that all institutions for medical care or nursing of old people should cooperate better than today.


[Indications for orthopedic procedures in old people (author's transl)]. Advancements in general medicine and anesthesiology have enabled surgical procedures in old people with diminished risks. With reference to special problems the absolute indication for orthopedic procedures particularly for the old can be demonstrated.


Model systems for studies on cellular basis of organ ageing. The cellular basis of the age-related decline in the functional capacity of many mammalian organs is still poorly understood. In this paper, the rat liver is presented as a promising model for studying cellular phenomena underlying organ ageing. The recent development of methods for isolation and purification of parenchymal, Kupffer and endothelial cells from the rat liver makes possible the comparison of functional and metabolic changes in the intact liver with changes in distinct liver cell classes isolated from rats of various age groups. An attempt has been made to correlate age changes in some important liver-specific functions, such as bromsulophthalein uptake and albumin synthesis, at the organ and at the cellular level. To compare cellular ageing phenomena in long-lived cells (parenchymal cells) and short lived cells (Kupffer and endothelial cells) from the same organ, the role of lysosomes in cellular ageing processes was investigated, with secial reference to the functioning of the lysosomal enzyme cathepsin D. The specific cathepsin D activity in Kupffer cells was abour 3 times higher than in endothelial cells and about 20 times higher than in parenchymal cells. The enzyme activity in the latter cell type showed a significant increase with age.


Age-dependent increase of intranuclear monovalent electrolytes as revealed by quantitative energy dispersive x-ray microanalysis. The concentration of univalent electrolytes in the cell nucleus and cytoplasm of the big neurons of the brain and in hepatocytes was established in young, mature and old rats by means of microanalysis with X-rays. It was demonstrated that the Na+ and Cl-- content increases with aging in both tissues, while K+ increases in the neurons but not in the nuclei of the hepatocytes, At the same time some ions in the cytoplasm increase, while others decrease or remain stable. If a possible loss of water during aging is taken into consideration the result is a considerable increase in ion concentration in the nucleus. This may be regarded as one of the principal reasons for the increased density which accompanies aging and possibly as one of the cause of the aging process.


On the relationship between the perichromatin granules and cellular ageing as well as cell differentiation. Current hypotheses ascribe the role of pre-RNA storage or transport structures to the perichromatin granules. Their numerical density is directly related to the transcription activity of the nucleus. The perichromatin granules (P.K.) can be demonstrated in ultrathin sections with the stain used by Bernhard (1969) for ribonucleo-proteins. We have established the numerical density per unit of area in nuclear cross-sections of cells in young rats (1-2 months), old rats (26-29 months) and in relation to various cell function types. Cell aging causes a reduction in the numerical density of perichomatin granules in the big neurons of the cerebral cortex, the cerebellar granulocytes, the hepatocytes and the parotid cells. No age-related changes were found in the myocardial cells and erythroblasts of the same maturity. However, at the end of maturation, the number of perichromatin granules both in young and old erythroblasts was nil. (1) There is a quantitative reduction of perichromatin granules primarily in postmitotic and relatively postmitotic cells; (2) cell types showing no age-related reduction in perichromatin granules maintain high synthetic activity throughout their life; (3) the results confirm that relationships exist between numerical density of the perichromatin granules and cell activity; (4) the big fluctuations in the numbers of perichromatin granules in various cell types are probably connected with cell function.


On the reversibility of some cytological ageing parameters of rat brain cells by phytohemagglutinin. It has been shown that the thermal stability of DNA in the brain cortical cells increases with the age. At the same time, the number of perichromatin granules being connected in some way to the messenger RNA synthesis and transport of the interphase nuclei, decreases in the same cells. In vivo treatment of the old animals by mitogens like phytohemagglutinin induced a reversal of both ageing phenomena: the thermal stability of DNA returned almost completely to that of the young animals, whereas the number of perichromatin granules rised again to the young level.


[Chromosomal investigations in two age groups of human females]. Chromosomal analysis was performed in cultured lymphocytes from 32 old (ages 76-85, abbr. A) and 31 young (ages 15-20, abbr. J) patients, who were representative for a great part of the "normal" female population of the same age. In regard to culture time (48 and 72 hours) each age group was divided into two halves; 1500 cells were examined in each of the resulting four sub-units (A 48, A 72; J 48, J 72). Whereas the frequency of "spontaneous" gaps showed no dependency from age or culture time, single chromatid breaks were predominantly observed in A 72 and dicentric chromosomes in A 48. The mean breakage rates in the two age groups (A 48 2,4% A 72 3,0%; J 48 1,3%, J 72 1,7%) differed significantly for both culture times (Chi2 -test: A 48/J 48 p less than 0,01; A 72/J 72 p approximately 0,01). After karyotyping and additional application of a trypsin-Giemsa-branding-technique large, acentric "fragments," which could only be detected in metaphases of old females (A 48 1,0%, A 72 0,5%), proved to be X-chromosomes with premature centromere division and a high tendency to non-disjunction. These results are in agreement with those published by Fitzgerald (8).


Age changes of turnover rates and subfraction composition of rat liver and spleen histones. Histones from tissues of young and old rats have been compared. Lysine-rich F1 histone was found to be the only one which is tissue specific and whose subfraction pattern changes in old cells. The comparison of turnover rates of different histones from liver and spleen, measured by the level of 3H-leucine incorporation and subsequent decay of its specific activity with time, showed that while the activity and turnover or arginine-rich histones F3 and F2a2 was reduced in old liver, ageing was associated with increased turnover of F1 histone. The results are discussed from the point of view of a special role of F1 histone in the condensation of chromatin and in the age-related inhibition of some cellular functions.


[On the biophysical interpretation of ageing-factors (author's transl)]. The ageing-factor is a measure for the rate of ageing. In the model of vitality the error rate mu corresponds to the ageing-factor. The ageing-factors of several physical functions can be determined from the ascent of decrease of these functions. The standardized ageing-factors of the considered physiological functions range from 0.001 to 0.017 year--1 and are smaller than the ageing-factor of the whole organism. The date of the occurrence of pathological manifestations as a result of ageing-conditioned decrease of functions can be estimated by means of the ageing-factors.


[Free amino-acids of the plasma in atherosclerotic patients (author's transl)]. 18 free amino-acids have been valuated in a group of patients recovering from myocardial infarction dating more than one year back and in another group of healthy active athlets. In the group of the ill persons the mean values of the following amino-acids were significantly higher: Arginine, asparagine-acid, phenylalanine, valine, lysine, serine, threonine, leucine, proline and tyrosine. While in the group of the healthy persons the following amino - acids proved to have significantly higher values: alpha -- aminobutter-acid, glycine and cystine. No significant differences between the mean values of both groups were to be found of the following amino - acids: Alanine, methionine, ornithine, isoleucine and histidine. In the group of the patients correlations of the free amino acids to both serumlipids and blood -- glucose could be calculated with significant results in a certain number of amino-acids. The results may suppose that the changes in the metabolism of atherosclerotic patients do not only effect the lipids and carbohydrates, but as well the free amino-acids.


Halothane depresses baroreflex control of heart rate in man. Baroreflex control of heart rate was determined during three awake control situations and during two depths of halothane anesthesia in man. Baroreflex function was quantiated by calculating the pressor test slope from the R-R interval change on the ECG produced by a pharmacologically induced pressor response. During the three awake control situations the subjects breathed room air or 100 per cent O2 spontaneously or 100 per cent O2 with ventilation controlled. Mean (+/- SD) slopes obtained were 15.1 +/- 4.5, 15.6 +/- 6.8 and 18.4 +/- 9.9, respectively. No significant difference in baroreflex function slope was observed. During light halothane anesthesia (0.7 per cent endtidal) baroreflex function was significantly depressed (mean slope = 2.5 +/- 1.5), and it was abolished at 1.1 per cent end-tidal halothane (mean slope = 0.03 +/- 0.04). It is concluded that halothane anesthesia produces depression of baroreflex control of heart rate in man.


[Neuroleptics and microsurgery of the ear]. In the field of research into new methods, we attempted to determine the primary effect, i.e. neuroleptic effects following the intensity of reactions to stimulation in patients undergoing microsurgery of the ear, comparing in particular the quantities of analgesic necessary and used during general anesthetic to ensure both clinically visible protection and, above all, suppression of the effects of stimulation at the level of recordings of arterial and venous pressures. This permits, in our opinion, one to evaluate the dose necessary but also, determine whether or not a drug belongs to the category of neuroleptics which are interesting for the anesthetist.


[Controlled arterial hypotension produced by nitroprusside combined with neuroleptics]. Ganglioplegic drugs, including trimetaphan, have been imperfect agents of arterial hypotension, liable to produce tachyphylaxis, and not blocking intercurrent attacks of adrenergic hypertension the dose is inconstant and reversibility sometimes doubtful. The association of neuroleptics, in particulier promazines, permits an appreciable economy in dosage, stabilises the curves of hypotension, with the disadvantage of blocking normalisation of blood pressure. Sodium nitroprusside does not have the disadvantage of ganglioplegic drugs. Although usable alone, the blood pressure graphs sometimes have a certain instability mainly due to the difficulty of regulating the ideal perfusion flow rate. The authors show that the association of neuroleptic drugs has here also an effect of economy of dosage and facilitates the rise in blood pressure. Verification of reinforcement of the effect of sodium nitroprusside by chlorpromazine, acepromazine and levomepromazine was carried out in the dog. The authors show significant graphs.


[Neuroleptanalgesia as the anesthesia in pediatric surgery]. In work carried out over a period of two years in the department of anesthetics and intensive care of the Saint-Etienne University Hospital, the authors report their experience of neuroleptanalgesia using droperidol-dextromoramide in children in 104 cases. The observations may be divided up into 2 groups: - 1 group of children below the age of 2 years; - 1 group of children from 2 to 10 years. This study showed the side-effects and complications common to both groups, in particular, the extrapyramidal syndrome. Furthermore, the authors present their technique of administration.


[Place of neuroleptics in geriatric anesthesia]. The elderly show changes in various parenchymas linked to the process of ageing. Pathological abnormalities may be added to this picture leading to physiopathology peculiar to the aged. In relation to special problems raised by this background, the advantages and disadvantages of N.L.A. are discussed. The authors refer to an experiment in the Department of Anesthetics and Intensive Care in Créteil.


[Current place of neuroleptics in cardiac surgery under extracorporeal circulation. Cardiovascular effects of different combinations]. We have been using narconeuroleptanalgesia for anesthesia in cardiac surgery under extra-corporeal circulation since 1969, and we have carried out about 3,500 anesthetics of this type on the 1st of October 1975. For all these anesthetics, the neuroleptic used was droperidol. The other components were: - in the case of the narcotic, penthiobarbital, then more recently Alfatesine; - in the case of the analgesic, either dextromoramide or phenoperidine or Fentanyl; in the case of the curare derivative, D, tubocurarine, and above all, pancuronium dibromide. The advantages of neuroleptanalgesia for such surgery seemed to us mainly: - greater cardio-vascular stability in patients with a heart lesion; - the possibility of better control of cardiac output, i.e. by fillingor by inotropic drugs, thanks to the relative vasoplegia produced by the neuroleptic. Finally, in a recent study, we attempted to determine the hemodynamic effect of droperidol and its association on various analgesic drugs measuring in a few patients the cardiac output, the peripheral resistances the the circulating blood volume. We will report the preliminary results of this study.


[Neuroplegia in cranial and cranio-thoracic injuries]. During severe head injuries, the reaction to the cerebral lesion is intense and characterised by a disturbance which is automatic, vasomotor and endocrine. Associated with general ventilatory and nutritional resuscitation, neuroplegia occupies in this pathology, aplace of choice. Cranio-thoracic traumas raise more complex problems owing to different ventilatory requirements, depending on whether the lesion is of the brain or thorax. One must therefore, find a compromise between the depression which necessarily occurs during a too intense autonomic reaction, and the ventilatory requirements created by the thoracic injury. In all cases, the micro-circulatory improvement produced by neuroplegic drugs is probably favourable. The authors report their experience of eighty severe cranio-thoracic traumas, over a period of thirty months, submitted to treatment including neuroplegics.


[Place of neuroleptics in neurosurgical anesthesia-resuscitation]. The interest of neuroleptics in neurosurgery should be examined in the light of physiopathological and pharmacological data concerning cerebral circulatory autoregulation and intracranial pressure. The fairly favourable conclusions permit one to consider their wide use justified, especially, by the feeble hypnogenic effects, without any marked disturbance of the E.E.G., associated with an anticatecholaminergic and stabilizing effect on the autonomic nervous system. They therefore occupy a place of choice, in particular during induction of anesthesia in high risk patients, during operations requiring neurological or continuous E.E.G. investigations, in surgery of intracranial aneurysm and, finally, to obtain sedation and post-operative autonomic control.


[Very-high-dose droperidol and brain stem injuries]. Treating four comatose children with severe injuries of the brain stem, suffering from severe autonomic disorders without any indications for neurosurgery, we were led to increase gradually the doses of neuroleptics used as basis of treatment, the main one being Droperidol. The increase in dosage, often reaching very high doses, was rendered necessary owing to a phenomenon comparable to that of addiction, a steadily increasing dose was necessary each day to obtain the same beneficial effects of autonomic stabilization. A complete cure was obtained on each occasion, at the end of a coma varying between 20 days and two and a half months. The extreme case was the last case in which we were led to give in a single day, 7 grams of the drug to a 12 years old child, who completely recovered his motor and intellectual functions after a coma lasting thirty five days. Comparison of the four cases led us to suppose that the result is all the better when treatment with neuroleptics is started soon after the accident, in low dosage but regularly increased without fixing any other ceiling than the effect obtained, the toxicity of Droperidol seemed to us very low, even in very high dosage, provided the conditions of gradualness are respected. Although it is classical to say that the prognosis of trauma of the brain stem is more favourable in children than in adults, we are certain that such treatment contributed considerably to avoid a fatal issue or chronic invalidism.


[Neuroleptics and continuous measurement of intracranial pressure]. Neurosurgical patients, whether injured or not, have benefited in recent years from a new technique of supervision, measurement of thr intracranial pressure (ICP). Thus, measurement of a pressure figure and its course, gives precious information, both diagnostic and therapeutic. Various techniques of measurement are now proposed. We chose, for special reasons, measurement of the ICP within the ventricle. A catheter is introduced into the ventricle through a trephine hole. It is linked by a liquid column to a recording system (cathode oscilloscope, ink writer or magnetic tape). A slow inscriber permits continuous recording of the ICP for several days or even weeks. In view of the narrow dependency of the ICP on other physiological parameters, it seemed to us essential to record simultaneously 5 other parameters, the temperature, the blood pressure, the central venous pressure, the heart rate and the respiratory ventilation, by measurement of FeCO2 (capnography). Several forms of treatment have been proposed to bring down a raised ICP (greater than 15 mm Hg), e.g. osmotic diuresis, hyperventilation, corticosteroid therapy. Removal of CSF by ventriculalar catheter, sometimes permits one to pass over the critical period. It was in this background that we attempted to analyse the effect of neuroleptics on the ICP, without attempting to explain their mechanism of action. Our study was of 10 patients with cranial trauma, of both sexes, aged from 14 to 60 years. The intracranial pressure was measured within the ventricle and correlated with the other physiological parameters. When the ICP was normal, e.g. primary lesion of the brain stem, administration of neuroleptics such as chlorpromazine 100 mg IV/24 hours, or levopromazine 50 mg IV/24 hours, does not modify the value of the ICP. On the other hand, in the case of raised intracranial pressure due to contusion with cerebral oedema, for example, the administration of neuroleptic drugs seems to provide a very slight reduction in this pressure. It would be interesting to measure, at the same time as the ICP, the cerebral blood flow.


[Note on the comparative effects of benzodiazepines and chlorpromazine on intracranial pressure in the dog]. The neutrality of the butyrophenones on intracranial pressure has been relatively well shown. That of the phenothiazines and benzodiazepine derivatives has been less well established. The authors studied, by a continuous method, the action of chlorpromazine, acepromazine and three benzodiazepines (diazepam, flunitrazepam and chlorazepam) on intracranial pressure and blood pressure in the dog. These substances seem to be definitely neutral on intracranial pressure, more so in the case of the benzodiazepines than for the promazines, the vasomotor action of which was perceptible when seen closely. The authors produce demonstrative graphs, illustrating the correlation of these two pressures.


Effect of adrenalectomy in the dog on blood gas tensions and oxygen content. Arterial and venous blood gas tensions and pH were determined in 8 dogs during a control interval, while adrenal deficient, and following replacement therapy with corticosteroids. Additionally, erythrocyte 2,3-diphosphoglycerate (DPG) values were measured, and oxygen tension (mm of Hg) when hemoglobin is half-saturated with oxygen (P50) values were calculated. Mixed venous oxygen tension (PVO2), but not arterial oxygen tension (Pao2), decreased significantly (P less than 0.001) during adrenal insufficiency. This change was reflected in a significantly decreased (P less than 0.001) venous oxygen content and a significant increase (P less than 0.001) of the arterial-venous oxygen content difference. Other changes during adrenal insufficiency were nonsignificant decreases in DPG and P50 values. Treatment with corticosteroids for 2 to 3 days resulted in a significant (P less than 0.001) increase in DPG concentrations, a significant (P less than 0.025) increase in P50, and a reduction in the arterial-venous oxygen content difference compared with those values found in the adrenal-deficient dog.


Salicylate pulmonary edema: the mechanism in sheep and review of the clinical literature. Several clinical reports of salicylate-induced pulmonary edema led us to investigate the mechanism in a chronic unanesthetized sheep preparation. We infused an aspirin-buffer solution intravenously at rates up to 1,200 mg of aspirin per hour and compared effects on lung lymph flow and lymph protein concentration to those seen after mechanical elevation of pulmonary vascular pressures. Aspirin had little effect on lung vascular pressures but caused lung lymph flow to increase an average of greater than twice baseline. Because lymph protein concentrations were higher for a given lymph flow with aspirin than during mechanical pressure elevation, lymph protein (lymph flow X lymph to plasma protein concentration) increased much more with aspirin. Thus, aspirin appears to cause increased permeability to fluid and protein in the pulmonary vascular bed. Aspirin caused arterial PO2 to decrease from 83 +/- 3 SE mm Hg to 74 +/- 3 mm Hg (P less than 0.05) and caused postmortem extravascular lung water to increase. These findings are supported by a review of the clinical literature, indicating that salicylate pulmonary edema in humans is noncardiac in origin and may occur at doses considered therapeutic for some diseases as well as after overdose.


Treatment of brain disease with dietary precursors of neurotransmitters. A growing number of brain diseases are characterized by decreased levels of one or more of the neurotransmitters. Recent experimental evidence indicates that nutritional factors strongly influence the regulation of two of these neurotransmitters, serotonin and acetylcholine. As a result, attempts are now being made to treat diseases associated with low levels of serotonin or acetylcholine by administering their dietary precursors, tryptophan and choline, respectively. This treatment may increase the amount of the deficient neurotransmitter at synapses and produce clinical benefit. Such efforts to elevate brain neurotransmitter levels with a naturally occurring precursor represent a new approach in medical therapeutics and will probably continue. We review the scientific basis for such treatment and show that brain levels of serotonin and acetylcholine depend upon the amounts of tryptophan and choline available to the brain; these, in turn, fluctuate according to dietary factors.


[Rabies glycoprotein purification by isoelectric focusing (author's transl)]. A glycoprotein was extracted with Triton X100 from rabies virus grown in primary foetal bovine kidney cells. This glycoprotein was further purified by iso electro focusing and showed a major peak at pH 7,0 and a smaller peak at pH 4,6. Purified fractions were migrated on polyacrylamide gels and assayed for immunogenicity.


[Studies on the mechanism of interaction of glutaraldehyde with microorganisms (author's transl)]. The antimicrobial action of glutaraldehyde on Candida lipolytica increases with reagent concentration, pH and duration of contact. The simultaneous study of the size distribution of the particles shows an agglutination of the cells. This result is confirmed by direct observation of the cells by electron microscopy. Cell agglutination also occurs with other microorganisms (Saccharomyces carlsbergensis, Bacillus megaterium, Escherichia coli) and increases their settling rate. The formation of such intercellular bonds seems to confirm the hypothesis of a preferential action of glutaraldehyde on the outer layers of the cells. The effect of pH on the antimicrobial action of glutaraldehyde is accounted for by the fact that this reagent does not act, under neutral and alcaline conditions, as a dialdehyde but as an unsaturated polymer. This mechanism also accounts for various observations made on microorganisms-glutaraldehyde interactions.


[Familial palmo-plantar keratoderma with epidermolytic hyperkeratosis (author's transl)]. Three cases of palmo-plantar keratoderma coming from three different families are reported; Clinical features were those of Thost-Unna's disease; histo-pathological and ultrastructural aspects resembled those of the epidermolytic hyperkeratosis. The literature, 13 cases within 7 families with the same clinical and histopathological characteristics (though without study of the ultrastructure), have been reported. The authors propose to term "familial palmo-plantar keratoderma with epidermolytic hyperkeratosis", those cases of palmo-plantar keratoderma with dominant autosomal transmission and the histopathological aspects of the epidermolytic hyperkeratosis (Frost and Van Scott). The relationship of this disease with the naevus unius lateris and the bullous ichtyosiform hyperkeratosis are discussed. All three diseases could represent various phenotypical aspects of the same genetic abnormality of the keratinization process.


Comparison of thiopentone versus althesin for caesarean section. Thiopentone and Althesin were compared in 50 patients undergoing general anaesthesia for Caesarean section. The patients were divided into group A (24 mothers) were thiopentone (3.5 mg/kg) was used for induction and group B (26 mothers) where Althesin (80 mu1/kg) was employed. Blood samples for estimating the maternal and umbilical venous and arterial blood pH, pCO2, BD and pO2 were taken at the time of delivery. The clinical condition of the newborn were estimated by the Apgar score. Postoperatively the mothers were interviewed about thei subjective opinion concerning the anaesthesia. The interview showed equal acceptance of both induction agents. The umbilical venous and arterial pH, pCO2 and BD were well within the normal physiological range and there was no significant intergroup difference. The only significant differences were the lower umbilical venous and arterial pO2 values in the Althesin group. The clinical condition of the newborn (Apgar score) showed no significant difference between the two groups.


[Optimization of conditions for determining the activity of amphotericin B]. The effect of incubation temperature, pH  and medium composition on the size of the growth inhibitions zones, clearance of their borders and slope of the dose-response curve in determin ation of the biological activity of amphotericin B by the agar-diffusion method using Candida scotti, Tul-1 as the test-microbe was studied. The composition of the medium providing optimal conditions for the activity assay according to the sone size and clearness was developed. When the above medium was used for determination of the biological activity of amphotericin B, the standard deviatioos of the assay results, as well as the average results obtained at an interval of 1 month were 1.5 times lower than with the use of the medium proposed at an interval of 1 month were 1.5 times lower than with the use of the medium proposed in Specification 42 No. 3857-70. At the same time the average results of the assay on both media coincided.


The phenol oxidases of the ascomycete Podospora anserina. XII. Affinity of laccases II and III to substrates with different substitution patterns. For the low molecular weight laccases II and III of Podospora anserina the kinetic parameters Michaelis constant (KM) and maximum reaction velocity (V) were determined polarographically under pH optimum conditions for representative substrates of different substitution patterns. Laccase II showed two peaks in its pH optimum curve, each with a different substrate specificity, indicating structural differences to laccase III which exhibits only one broad peak. Under optimum conditions the affinities of various substrates are determined by their substitution patterns: high affinity for simple o- and p-diphenols, low affinity for m-henols. The maximal velocity remains largely uninfluenced. This study of the effect of substitution on substrate utilization leads to the assumption that there is no specific reactive site for m-phenols in either laccase. Oxidation of m-phenols, however, takes only place at high pH values.


Comparative studies of lactic acid dehydrogenases in lactic acid bacteria. I. Purification and kinetics of the allosteric L-lactic acid dehydrogenase from Lactobacillus casei ssp. casei and Lactobacillus curvatus. The stability, pH-dependence and kinetic properties of the Mn2+ and FDP-activated NAD-dependent lactic acid dehydrogenases from Lactobacillus casei ssp. casei (ATCC 393) and L. curvatus (DSM 20010) were studied after the enzymes were purified to homogeneity by affinity chromatography. Both enzymes are virtually unidirectional, catalysing efficiency only the reduction of pyruvate. They are similar with respect to the effector requirement and pH-optimum. They differ, however, in their electrophoretic mobility, heat stability, pH-dependence of the Mn2+ requirement and several kinetic properties. It is suggested that most of these differences are caused by differences of the negative charges in the vicinity of the FDP-binding site or the site responsible for the interaction of the subunits of the enzymatically active oligomeres.


Therapeutic usefulness of propoxyphene napsylate in narcotic addiction. The maximum doses of propoxyphene napsylate used to treat heroin addicts produce a degree of morphine-like activity equal to that produced by 20 to 25 mg/day of subcutaneously given morphine or 10 mg/day orally given methadone. This degree of activity wound be sufficient to ameliorate abstinence even in patients dependent on large doses of narcotics--an observation that supports the utility of propoxyphene napsylate in detoxification. On the other hand, only patients taking 10 mg/day or less of parenterally administered heroin could be maintained on maximum subtoxic levels of propoxyphene napsylate without abstinence signs or symptoms suggesting that propoxyphene napsylate would be less useful in maintenance therapy.


Antidepressants and the muscarinic acetylcholine receptor. Several tricyclic antidepressants have been assessed for their potency in binding to the muscarinic acetylcholine receptor of brain and intestine. Amitriptyline hydrochloride is about ten times as potent as imipramine hydrochloride. Dimethylated drugs are more potent than monomethylated ones. The relative anticholinergic activities of tricyclic antidepressants have implications for their use in patients who might be affected adversely by anticholinergic effects.


[Acute sepsis caused by "Gaffkya tetragena" in adult with hypogammaglobulinemia (author's transl)]. A case of acute sepsis caused by Gaffkya tetragena in an adult with acquired hypogammaglobulinemia has been described. The Authors pointout the importance that particular conditions of disreactivity and/or of immunodeficiency can play in the acquistion of pathogenicity by Gaffkya tetragena. In the case under discussion a high deficit of IgG and IgA was demonstrable, which had previously caused a long series of infective bacterial diseases.


[Clinical trial with barbexaclone in epilepsies]. A open clinic assay with barbexaclone which is an association of phenobarvital with light stimulant of the central nervous system (tau-l-ciclohexil-2-methil-aminopropane) for the treatment of epileptic disorders is reported. The authors have studied 40 patients aged between 0-12 years of age, of both sexes, all of them having convulsive seizures of the Grand Mal type associated or not to other epileptic manifestations. After analysing the different aspects of the group they consider satisfactory the results obtained: very good or good in 82,5% of the cases.


Simultaneous determination of skeletal muscle fiber, types I, IIA, and IIB by histochemistry. We describe a simplified technique for the histochemical determination of three fiber types from a single section of skeletal muscle. Preincubation in a solution of formaldehyde, glycine, and calcium followed by routine myofibrillar adenosine triphosphatase (ATPase) incubation clearly differentiates type I, type IIA, and IIB fibers in human, rat, rabbit, and porcine muscle. In addition, glycine-formaldehyde-calcium preincubation offers better preservation of cytoarchitecture and standardization of incubation time.


Variations in the spectrum of desulfoviridin from Desulfovibrio gigas. Desulfoviridin preparations from D. gigas showed variations in the position of the absorption maximum the beta-peak) in the 580-nm region of the specturm. On treatment with Na2S2O4 a preparation with a beta-peak at 585 nm was affected rapidly, the 585-nm peak shifting to the 596-nm region; this was partially reversed by K3Fe(CN)6. Treatment of the original preparation with K3Fe(CN)6 resulted in a shift of the beta-peak to 582-583 nm. Desulfoviridins with beta-peaks from 580 to 583 nm were not rapidly affected by Na2S2O4. The spectrum of the chromophore of desulfoviridin way also affected by Na2S2O4 with the peak at 587 nm shifting to 597 nm; this effect was completely reversed by oxygen. There was no evidence to show that spectral variations in desulfoviridin preparations were due to the loss or acquisition of metal ions during growth or to the selection of mutants containing spectrally different desulfoviridins. It is suggested that during biosynethesis oal detachment of the chromophore, thus causing a change towards the spectral properites of the detached chromophore.


An alternative coupling procedure for preparing activated sepharose for affinity chromatography of penicillinase. Most applications of affinity chromatography employ the cyanogen bromide activation scheme first devised by Axèn et al. (1967). Porath and Sunberg (1972) reported an alternative procedure in which phloroglucinol and divinylsulphone are used in activating reactions. The advantages of this scheme and parameters relevant to the activating reactions are reported here. Conditions for the attachment of various ligand molecules to sepharose using a divinylsulphone activation method are defined, and a comparison with cyanogen bromide activating and coupling techniques is drawn. alpha-Chymotrypsin is immobilized by covalent attachment to activated sepharose. The optimum coupling pH is 8-0-8-6 and the reaction is virtually complete after 20 h at room temperature. Conjugates containing as much as 2 g of enzyme per gram dry weight of polymer were obtained. The immobilized enzyme retained 41% of the free enzymic activity. An affinity column of divinylsulphone-activated methicillin-sepharose was used to demonstrate the reversible adsorption of penicillinase.


Studies on the apoproteins of the major lipoprotein of the yolk of hen's eggs II. The dimer-tetramer transition of apovitellenin I. Further studies have been made of the physical properties of hen's apovitellenin I, the principal low-molecular-weight protein from the high-lipid low density lipoprotein of the yolk of hen's eggs. The methods used included chromatography, sedimentation, viscosity, optical rotation, and spin labelling; the solvents used were aqueous urea, and, for some experiments, aqueous formamide. It is concluded that a neutral pH the protein is present in these solvents as an aggregate of molecular weight 36000 corresponding to a tetramer. Below about pH 4-5 solutions of the tetramer increased greatly in viscosity; furthermore, a covalently bound spin label increased in mobility. These changes were reversible and were apparently the result of dissociation of the tetramer to a dimer. This disociation did not involve a change in the proportion of alpha-helix. In contrast to the results of previous experiments, it now seems probably that the apovitellenin I dimer is stabilized by an interchain disulphide bond.


Biochemical differences between alcohol dehydrogenases of Drosophila melanogaster. This paper describes substrate specificities, developmental changes in activity, pH profiles, and heat stabilities of isozymes produced by four Adh genotypes in D. melanogaster. No differences are found in the substrate specificities of isozymes from the different genotypes but studies of the other three properties reveal significant differences between the isozymes. Thus relatively low activities are found among extracts of AdhF Adhn2 larvae and among extracts of AdhF AdhF adults aged 44 days. Also AdhF AdhS and AdhS AdhS extracts have relatively high activities at pH 6-5, and AdhF Adhn2 extracts have relatively low activities at pH values above 10-0. Finally, extracts of AdhF AdhF and AdhF AdhS are more stable at 40 degrees C than are those of AdhS AdhS and AdhF Adhn2.


Ord River arboviruses--the study site and mosquitoes. The Ord Valey of tropical Western Australia has been studied for arbovirus activity following the development of a man-made lake of considerable size, a diversion dam and an irrigation scheme. Kununurra, the largest town in the valley, is the focus for very large populations of  birds and mosquitoes. The irrigation areas have not been important as mosquito breeding areas because of the excessive use of insecticides. Lake Argyle does not support high mosquito a bird population at present. However, this may change as the ecosystem stabilizes. The mosquito fauna of the Ord Valley is dominated by Culex annulirostris.


Ord River arboviruses--isolations from mosquitoes. One hundred and thirty presumptive viruses have been isolated from 485 pools made from 23,872 mosquitoes collected in the Ord River area of North-West Australia. One hundred and eleven of the virus isolates isolates came from pools of Culex annulirostis, the dominant mosquito species caught in the vicinity of Kununurra. Forty-five of the viruses pathogenic for newborn mice have been further characterized-19 as Flaviviruses, 1 Alphavirus, 9 Koongol, 1 Mapputta and 15 non-haemagglutinating viruses of which 6 are Corripata. Thirty-seven isolates were from Culex annulirostis, 7 from Aedomyia catasticta and 1 from aedes tremulus. All Corriparta isolates were from Aedomyia catasticta. The Flaviviruses comprised 13 Kunjin and 6 MVE isolates.


Essential hypertension--the starting point for improved drug treatment. Hypertension is a common disease and plays an important role as a potentially remediable contributor to cardiovascular causes of death in the community. In moderate to severe hypertension recent treatment has improved morbidity and mortality substantially, but it is disappointing that despite this myocardial infarction still stands as an important cause of death. In this regard it is encouraging that beta adrenergic blockade may be useful not only in lowering blood pressure, but also possibly in reducing independently the risk of myocardial infarction and/or sudden death in some patients. In mild hypertension the number of patients is large and the possible beneficial effect of treatment less well-established, so that there is a clear need for further research in order to define patients at relatively high risk in this group.


Pharmacodynamic studies on the antihypertensive effectiveness of beta-blocking drugs. Beta-adrenoceptor antagonists are effective antihypertensive agents in the majority of patients with uncomplicated essential hypertension. Their antipressor activity is greater on systolic than diastolic pressure and greatest during dynamic exertion. Their circulatory effects are maximum within 1-2 hours of ingestion and the antipressor effects of a single dose are detectable for over eight hours. Both the immediate and long-term blood pressure lowering effects of these drugs are dose-related. The reduction in exercise systolic pressure is related to the logarithm of the dose of each drug; the reductions in pressure at rest follow no simple mathematical function. There is wide individual variation in the plasma concentrations achieved after a given oral dose, although the averaged values follow a linear regression. There are wide discrepancies between plasma-concentration profile and magnitude and duration of antihypertensive activity; blood pressure lowering activity persists for significantly longer than the drug is detectable in plasma. The antihypertensive effects of the beta-blocking drugs are enhanced during chronic administration without habituation. Their effects are specific but independent of the immediate presence of the drug, i.e. blood pressure lowering activity persists after clearance of the drug from the body. The ancillary pharmacological properties of these drugs neither augment nor detract from their antihypertensive potency, although the possession of intrinsic vasodilator activity enhances reduction in the blood pressure standing at rest. Beta-blocking drugs add a new dimension to antihypertensive treatment in their specific potential to reduce the coronary consequences of the disease.


Blood pressure variability in patients on beta-blockers. The direct arterial blood pressure was monitored over 24 hours in unrestricted untreated patients in order to obtain the average pressure and standard deviation over 24 hours. The standard deviation was taken as the index of variability of pressure. In eight subjects the study was repeated three months after commencement of treatment with a beta-adrenergic blocking agent (tolamolol, 300 mg/day). In these subjects tolamolol resulted in a fall in mean blood pressure from 107 to 92 mmHg (P less than 0-05) and a fall in heart rate from 82 to 70 beats per minute (P less than 0-01). The variability in blood pressure, however, was unaffected by treatment.


A beta-blocker-based antihypertensive drug program guided by age and renin. From analyses of the effectiveness of beta-blocker monotherapy in relation to the patient's age and to pre-treatment renin determinations an antihypertensive drug program is proposed in which beta-blockers form the cornerstone. Patients with essential hypertension can be subdivided into groups with low (19%), normal (59%), or high (23%) renin sodium index. The proportion with low renin hypertension increases with age. Patients with high renin fall into two categories: younger patients with fairly mild hypertension and older pateients with more severe hypertension and signs of renal disease. The antihypertensive efficacy of beta-blocker monotherapy is best in high renin forms, good but less consistent in normal renin patients and uniformly bad in low renin hypertensives. In relation to age, beta-blockers normalized blood pressure (larger than or equal to 95 mmHg diastolic) in three-quarters of the younger than 40-year-olds, in about half of those aged 40--60 years, but in only 20% of those aged over 60 years. On this basis, it is postulated that the older patients with a low renin exhibit a relatively hypoadrenergic state while those with a normal or high renin--for a given age and elevated pressure--have a relatively increased adrenergic nervous activity. Because the beta-blockers have a potent suppressive action on the renin-angiotensin system--and, as a consequence, on angiotensin vasoconstriction, aldosterone volume expansion and central stimulatory feedback mechanisms--their antihypertensive mode of action may be linked to an important extent, though not exclusively, to renin suppression.


The pharmacokinetic characteristics of beta-receptor antagonists in man--similarities and differences of clinical relevance. The aliphatic partial structure common to the beta-receptor antagonists leads to similar products of their biotransformation. The main qualitative and quantitative differences of the metabolism of the compounds of this class, however, rest in the nature of their aromatic or heterocyclic substituents. The physico-chemical properties of the beta-blockers appear to be predominantly responsible for the extent of metabolic degradation and for the distribution in the body, especially for the binding to proteins. As a consequence of their different biological disposition the clinically relevant systemic bioavailabilities of the various beta-blockers from oral doses differ drastically. Practolol maintains an extreme position among all other compounds: It is most hydrophilic, it is not bound to proteins, it is metabolized least, but cleared renally in unchanged form to 85% of the dose. Despite its extremely high systemic bioavailability, relatively high daily doses were required for therapy. The receptor sensitivity for practolol has been rated 2 to 3 powers of 1- lower than of propranolol. Comparative pharmacokinetic assessment of beta-receptor antagonists requires quantitative analytical data in clinically representative groups of patients. This has been demonstrated by respective studies with oxprenolol. The intra- and inter-individual systemic bioavailability, the differential analysis of plasma and erythrocytes, the multiexponential elimination kinetics, and their possible dependence on the dose have been studied as clinically relevant pharmacokinetic characteristics. The continuing attempt of the pharmaceutical industry to optimize the properties of beta-blockers also has taken advantage of the slow release principle in oral dosage forms as shown by the example of oxprenolol. The beta-receptor antagonists belong to one of the youngest classes of pharmaceuticals. Pharmacokinetic and metabolic data for the different representatives of this class have been generated in different laboratories with different approaches and different techniques. Therefore, full comparative documentation is still incomplete.


The vasodilator--beta-blocker interaction--some determinants of its clinical success. A number of structurally dissimilar compounds, sharing the ability to induce vasodilatation have come into clinical usefulness as antihypertensive drugs. Their successful utilisation often depends critically on an appropriate combination with diuretics and beta-blockers. Beta-blockers can specifically inhibit the reflex cardiac stimulation which otherwise may limit the tolerability and haemodynamic value of these drugs. A synergistic antihypertensive effect has been demonstrated with hydrallazine and propranolol and possibly exists with other combinations. Generally, vasodilators are not first-line drugs in chronic therapy but are best added to beta-blockers. Variations of the dose-response and the time-course of effect are stressed as being important determinants of a successful interaction.


Additive effect of beta-adrenergic blockers in combination with vasodilators in lowering blood pressure. Complications of hypertension are by far the greatese preventable public health problem in many of the developed countries of the world. Pharmacologic interventions which primarily involve drug interactions are the generally available and effective means of preventing or delaying these hypertensive complications. Mechanisms of beneficial antihypertensive drug interactions involve simultaneous reduction or control of blood volume (diuretic agents) and decrease of peripheral resistance. Reduction of peripheral resistance without producing intolerable side effects has recetnly been achieved by a complex drug interaction. This interaction involves simultaneous vasodilation and inhibition by beta-adrenergic blocking agents of reflex activation of the renin-angiotensin axis. Clonidine, by effects similar to propranolol, can substitute for propranolol in some patients, or add to the beneficial effects of this important drug interaction.


Labetalol (AH5158), a competitive alpha- and beta-receptor blocking drug, in the management of hypertension. The effects of intravenous labetalol, a drug with both alpha- and beta-adrenergic receptor blocking actions, have been studied in 20 severely hypertensive patients. There was a prompt and sustained fall in arterial pressure; severe hypotension did not occur in recumbent patients but postural hypotension was common. Pulse rate was consistently reduced, but bradycardia was not a problem. Significant and correlated falls in plasma angiotensin II and aldosterone were seen. In a direct comparison with intravenous propranolol, labetalol was less effective in lowering plasma angiotensin II, but more effective in reducing blood pressure. Oral labetalol provided good control of blood pressure and other features in two patients with phaeochromocytoma. Intravenous labetalol was similarly effective in controlling a hypertensive crisis following clonidine withdrawal.


A comprehensive behaviour modification programme for the treatment of anorexia nervosa: results in six cases. Behavioural analysis and psychodynamic hypotheses were used to develop a comprehensive behaviour modification programme for the treatment of primary anorexia nervosa. This was applied to six female patients and the results obtained are reported.


The relationship between chemical structure and basicity in some morpholine compounds. The influence of various substituents upon the pKa values of a series of 2-phenylmorpholines is discussed. The results are interpreted in terms of the preferred conformations of the morpholine ring and the inductive effect of the various substituents. The lack of analgesic activity in these compounds could be attributed to their low pKa.


Hysteresis at an electrochemical membrane model and its possible role in circulation research. On an artificial electrochemical membrane, properties of hysteresis are demonstrated by cyclic variation of pH. The properties are decreased by cAMP, theophylline, cysteine, heparin and increased by ADP.


Physiological antagonism between PGE2, PGA1, PGF1-alpha and NADP, beta-NAD on isolated rabbit jejunum. The antagonistic action between the prostaglandins PGE2, PGA1 and PGF1-alpha, on the one hand, and nicotinamide-adenine-dinucleotide-phosphate (NADP or TPN) and beta-nicotinamide-adenine-dinucleotide (beta-NAD or DPN) on the other, were experimentally studied on rabbit isolated jejunum. Our results support our previously expressed hypothesis that in the living organism there exist regulatory systems to control the actions of extremely potent substances such as the PGs. NADP and beta-NAD may therefore be grouped together with AMP, ADP and ATP as naturally occurring compounds that antagonise the actions of PGs.


An experimental and clinical pharmacological study of the influence of triamterene on the diuretic and saluretic properties of furosemide xantinol. The diuretic and saluretic effect of furosemide xantinol administered alone and mixed with different amounts of 2,4,7-triamino-6-phenylpteridine (triamterene) have been investigated in rat and man. The presence of triamterene resulted in a dose dependent inhibition of furosemide xantinol induced diuresis in both species. It was necessary to reduce the amount of triamterene present in the mixture to approximately half that of the one theoretically required according to considerations of the recommended therapeutic doses of the two diuretics before significant inhibition was avoided. Nevertheless, this reduced amount of triamterene proved sufficient to inhibit the distal tubular exchange of Na+ for K+ and H+ and a mixture formulated to give the ratio of 40 mg furosemide xantinol (as base) plus 25 mg triamterene (Salidur) was shown to produce a smooth but efficient loss of water and Na+ in the absence of detectable kaliuresis or reduction in urinary pH, thereby reducing the usual risk of inducing hypokalaemic alkalosis.


Inhibitory effect of beta-adrenergic stimulants on the histamine reaction in human skin. I. Studies with fenoterol. In 20 volunteers histamine inhibition by fenoterol (Th 1165 a) was studied. The wheal and erythema reaction caused by intracutaneous application of 5 mug histamine can be inhibited by applying fenoterol in doses from 100--400 mug in form of a metered aerosol on the skin 5 min before the injection of histamine. In this study the dose-reaction effect yielded on ED50 of 140 mug fenoterol.


[Double-blind clinical study of carpipramine/placebo (author's transl)]. A statistically planned double blind cross-over test with the substances 1-[3-(10,11-dihydro-5H-dibenz[b;f]-azepin-5-yl)-propyl]-4-piperidino-piperidine-4-carboxamide dihydrochloride-monohydrate (carpipramine, BAY b 4343 b) and placebo (BAY b 4343 a) was carried out on 30 long-term hospitalized schizophrenic patients. The study was evaluated by means of the kappa2-test and yielded the following results: 1. It could be statistically proved that carpipramine has a positive effect on psycho-pathological disorders in the behaviour of long-term hospitalized schizophrenic patients (kappa2 = 9.224; FG = 1; p greater than 0.05). 2. As regards the favourable influence of carpipramine on "productive" versus "non-productive" form of schizophrenia there were no differences. 3. Side effects or complications of a psychic, autonomic and/or motoric manner could not be seen. The usual laboratory tests showed no deviation from normal.


[Activity profile of carpipramine. Results of an open trial and a double-blind trial versus doxepin]. During an uncontrolled trial 46 depressed patients (39 endogenous depressions, 5 schizoaffective psychoses and 2 paranoic schizophrenics with depressive syndromes) were treated for 43 days on the average with 3 X 100 mg 1-[3-(10,11-dihydro-5H-dibenz[b,f]-azepin-5-yl)-propyl]-4-piperidino-piperidine-4-carboxamide-dihydrochloride-monohydrate (carpipramine) daily. The clinical impression of the improvement and the results of the Hamilton-Scale for depressions (19 patients, 24 items) showed a clear antidepressive effect of carpipramine. During a double-blind trial 14 patients were treated with carpipramine and 16 with doxepine for 30 days. Most patients suffered from endogenous depressions with paranoic symptoms or from schizophrenia with depressive syndromes. Statistical analysis of the Hamilton-Scale for depressions and the AMP-System showed the antidepressive and antipsychotic effect of carpipramine. Analysis of covariance showed no significant difference between carpipramine and doxepine. Altogether we treated 60 depressive patients with carpipramine. 26 patients improved very well and 11 moderately, that means 37 patients out of 60 reacted positively to therapy with carpipramine. One endogenous depression and a schizoaffective psychosis changed into a manic phase. A provocation of schizophrenic symptoms was not noticed. Carpipramine was very well tolerated and can be classified as a non-sedative antidepressant with an antipsychotic effect.


Lack of beta-adrenergic activity of isoflurane in the dog: a comparison of circulatory effects of halothane and isoflurane after propranolol administration. The studies were undertaken to determine whether isoflurance inhalation is associated with a degree of beta-adrenergic action that is potentially important in clinical situations, and to compare the circulatory tolerance to isoflurane and halothane in dogs following beta blockade. We measured arterial and pulmonary artery pressure, left and right ventricular filling pressure, heart rate and cardiac output, and derived stroke volume and systemic and pulmonary vascular resistances in 13 mongrel dogs. The haemodynamic response to 1 MAC and 2 MAC isoflurane was studied in seven dogs and was similar before and after propranolol 0.1mg/kg i.v. In six dogs, propranolol 0.5mg/kg caused no significant changes in the circulatory response to 1 MAC and 2 MAC isoflurane or 1 MAC halothane. However, in three dogs, administration of 2 MAC halothane after propranolol 0.5mg/kg resulted in such profound circulatory depression as to preclude further study. These data suggest that (a) isoflurane possesses no clinically important beta-adrenergic stimulating activity; (b) there is no adverse drug interaction upon the circulation with the combination of isoflurane and propranolol; (c) in the presence of moderated profound beta-adrenergic blockade, 2 MAC isoflurane may be tolerated better than 2 MAC halothane.


An evaluation of the AVL 937C blood-gas and pH microanalyser. The AVL 937C blood-gas and pH microanalyser was evaluated with particular reference to its use in obsterics and in neonatal paediatrics in which its ability to analyse blood smaples as small as 40 micronlitre would be of particular value. Analysing samples of cord blood, maternal venous blood and foetal scalp blood, the reproducibility over the range of values measured was excellent with samples of 40-100 micronlitre. SD of the variation in values measured on samples collected in syringes were po2 0.11 kPa; Pco2 0.21 kPa; PH 0.005 unit. The same values for specimens collected in capillary tubes were: Po2 0.19 kPa;Pco 0.43 kPa; pH 0.013 unit. Analysis of tonometered blood samples showed a similar high standard of accuracy. The 91-98% confidence limits for the measurement of blood-gas values in samples collected in syringes were: Po2-0.22 to +0.49kPa; Pco2-0.53 to +0.42 kPa. The same values for samples collected in capillary tubes were: Po2 -0.38 to +0.70 kPa; Pco2 -0.97 to +0.86 kPa.


Relative amnesic actions of diazepam, flunitrazepam and lorazepam in man. 1. Ten postcards were shown to groups of ten to twenty patients over 60, 90 or 270 min after intravenous injection of saline, diazepam (10 and 20 mg), flunitrazepam (1 and 2 mg) and lorazepam (4 mg). 2. Incidence of amnesia was estimated by the patients' ability to recall or recognize these cards and to recall various other incidents in the para-anaesthetic period. 3. The use of a dummy confirmed the reliability of the method of testing for amnesia in man. 4. Flunitrazepam produced a dose-related incidence of amnesia slightly longer than with the equivalent (1 x 10) dose of diazepam. 5. The onset of amnesia was slower with lorazepam (4 mg) but appeared to last for up to four hours. 6. This amnesic action of lorazepam was paralleled by a useful sensitive effect but there was no similar correlation for diazepam and flunitrazepam. 7. With three drugs of different duration of action it should be possible to produce amnesia for any required clinical situation.


Plasma concentrations of benzodiazepines. 1. Twenty anxious patients were treated with medazepam, diazepam, chlordiazepoxide, amylobarbitone and placebo, each given in flexible dosage for 2-4 weeks. 2. At the end of each treatment, a series of clinical, physiological and behavioural variables were measured and plasma samples were taken for estimation of the appropriate drug and metabolite concentrations. 3. Nordiazepam was shown to be an important metabolite of both medazepam and diazepam: the ratio of medazepam to noradiazepam was 0.14 and the ratio of diazepam to nordiazepam following diazepam administration was 0.72. 4. No significant correlations were found between the plasma concentrations of any of the treatments and the clinical ratings or behavioural measures. 5. Some relationship was shown between levels of medazepam and its physiological effects.


Conformational transition accompanying the binding of Ca2+ to the protein activator of 3',5'-cyclic adenosine monophosphate phosphodiesterase. The Ca2+-dependent protein activator of 3':5'-cyclic adenosine monophosphate phosphodiesterase is shown to undergo a conformational transition upon binding of 2 mol of Ca2+/mol of activator. Circular dichroic studies indicate that Ca2+ induces an increase of 5-8% in alpha-helix content with a concomitant decrease in the amount of random coil. In the absence of Ca2+ and in the presence of [ethylenebis(oxoethylenenitrilo)]tetraacetic acid (EGTA), the protein contains 30-35% alpha helix, 50% random coil, and 15-20% beta-pleated sheat. Spectrophotometric titration indicates that the two tyrosyl residues have pK's of 10.4 and 11.9 and are therefore in different environments. The Ca2+-induced conformational change is accompanied by an increased exposure to protons of the partially exposed tyrosine, as shown by a shift in its pK from 10.4 to 10.). Increased solvation is also consistent with a negative difference spectrum at 287 and 279 nm as seen upon Ca2+ binding. Modification in the environment of all or some of the phenylalanine residues also is part of the conformational change accompanying Ca2+ binding. A new and rapid purification procedure which yields large amounts (25-30% yields) of homogenous protein activator and a direct and sensitive assay procedure for cAMP phosphodiesterase and its activator are also described.


The electrochemical proton gradient in Escherichia coli membrane vesicles. Membrane vesicles isolated from Escherichia coli grown under various conditions generate a transmembrane pH gradient (delta pH) of about 2 pH units (interior alkaline) under appropriate conditions when assayed by flow dialysis. Using the distribution of weak acids to measure delta pH and the distribution of the lipophilic cation triphenylmethylphosphonium to measure the electrical potential (delta psi) across the membrane, the vesicles are demonstrated to develop an electrochemical proton gradient (delta-muH+) of almost - 200 mV (interior negative and alkaline) at pH 5.5 in the presence of reduced phenazine methosulfate or D-lactate, the major component of which is a deltapH of about - 120 mV. As external pH is increased, deltapH decreases, reaching 0 at about pH 7.5 and above, while delta psi remains at about - 75 mV and internal pH remains at pH 7.5-7.8. The variations in deltapH correlate with changes in the oxidation of reduced phenazine methosulfate or D-lactate, both of which vary with external pH in a manner similar to that described for deltapH. Finally, deltapH and delta psi can be varied reciprocally in the presence of valinomycin and nigericin with little change in delta-muH+ and no change in respiratory activity. These data and those presented in the following paper (Ramos and Kaback 1976) provide strong support for the role of chemiosmotic phenomena in active transport and extend certain aspects of the chemiosmotic hypothesis.


The relationship between the electrochemical proton gradient and active transport in Escherichia coli membrane vesicles. In the previous paper [ramos, S., and Kaback, H.R. (1977), Biochemistry 16 (preceding paper in this issue)], it was demonstrated that Escherichia coli membrane vesicles generate a large electrochemical proton gradient (delta-muH+) under appropriate conditions, and some of the properties of delta-muH+ and its component forces [i.e., the membrane potential (delta psi) and the chemical gradient of protons (deltapH)] were described. In this paper, the relationship between delta-muH+, delta psi, and deltapH and the active transport of specific solutes is examined. Addition of lactose or glucose 6-phosphate to membrane vesicles containing the appropriate transport systems results in partial collapse of deltapH, providing direct evidence for the suggestion that respiratory energy can drive active transport via the pH gradient across the membrane. Titration studies with valinomycin and nigericin lead to the conclusion that, at pH 5.5, there are two general classes of transport systems: those that are driven primarily by delta-muH+ (lactose, proline, serine, glycine, tyrosine, glutamate, leucine, lysine, cysteine, and succinate) and those that are driven primarily by deltapH (glucose 6-phosphate, D-lactate, glucuronate, and gluconate). Importantly, however, it is also demonstrated that at pH 7.5, all of these transport systems are driven by delta psi which comprises the only component of delta-muH+ at this external pH. In addition, the effect of external pH on the steady-state levels of accumulation of different solutes is examined, and it is shown that none of the pH profiles correspond to those observed for delta-muH+, delta psi, or deltapH. Moreover, at external pH values above 6.0-6.5, delta-muH+ is insufficient to account for the concentration gradients established for each substrate unless the stoichiometry between protons and accumulated solutes is greater than unity. The results confirm many facets of the chemiosmotic hypothesis, but they also extend the concept in certain important respects and allow explanations for some earlier observations which seemed to preclude the involvement of chemiosmotic phenomena in active transport.


Studies of individual carbon sites of azurin from Pseudomonas aeruginosa by natural-abundance carbon-13 nuclear magnetic resonance spectroscopy. The environments of the aromatic residues (and of the single arginine residue) of azurin from Pseudomonas aeruginosa are investigated by means of natural-abundance 13C Fourier transform NMR spectroscopy. In the case of the diamagnetic Cu(I) azurin, all 17 nonprotonated aromatic carbons (and Czota of Arg-79) yield narrow resonances. Furthermore, a single-carbon amide carbonyl resonance with an unusual chemical shift (peak chi) is observed. The pH dependence of chemical shifts is used to identify the resonances of Cgamma of titrating histidines, and of Cgamma and Czota of the two tyrosines. The resonances of Cgamma and Cdelta2 of the single tryptophan residue (and Czota of Arg-79) are also identified. The pKa values of the two tyrosines are different from each other and higher than typical values of "solvent-exposed" tyrosine residues. Two of the four histidine residues do not titrate (in the pH range 4 to 11). The resonance of Cgamma of one histidine exhibits a pH titration with fast proton exchange behavior and a pKa of 7.5 +/- 0.2. The direction of the titration shift indicates that the imidazole form of this histidine is the Ndelta1-H tautomer. The Cgamma resonance of the other titrating histidine exhibits slow exchange behavior with a pKa of about 7. The imidazole form of this histidine is the Nepsilon2-H tautomer. When going to the paramagnetic Cu(II) protein, only 11 of the 19 carbons mentioned above yield resonances that are narrow enough to be detected. Also, some of the observed resonances exhibit significant paramagnetic broadening. A comparison of spectra of fully reduced azurin, mixtures of reduced and oxidized azurin, and fully oxidized azurin yields the following information. (i) Peak chi arises from an amide group that probably is coordinated to the copper. (ii) The two nontitrating histidine residues are probably copper ligands, with Ndelta1 coordinated to the metal. (iii) The side chains of Arg-79 and the two tyrosine residues are not coordinated to the copper, and Trp-48 is probably not a ligand either. (iv) The gamma carbons of Trp-48, the tyrosine with the lower pKa, the titrating histidine with slow exchange behavior, and three or four of the six phenylalanine residues are sufficiently close to the copper to undergo significant paramagnetic broadening in the spectrum of oxidized azurin.


Active proton uptake by chromaffin granules: observation by amine distribution and phosphorus-31 nuclear magnetic resonance techniques. The hydrogen ion activity within isolated chromaffin granules can be estimated from the distribution of the weak base methylamine and from phosphorus-31 nuclear magnetic resonance spectra of ATP contained in the granules. Following the addition of ATP to the external medium, the internal pH drops by 0.2 to 0.5 unit. This change occurs only in medium containing a permeant anion such as chloride and is abolished by an uncoupler of oxidative phosphorylation. These results indicate that the chromaffin granule membrane possess an electrogenic proton pump directed inward.


Determination of the microscopic and macroscopic acid dissociation constants of glycyl-L-histidyl-L-lysine and related histidine peptides. Proton magnetic resonance studies of the acid-base chemistry of the glycyl ammonium, histidyl imidazolium, and lysyl ammonium groups of glycyl-L-histidyl-L-lysine and of the glycyl ammonium and histidyl imidazolium groups of glycyl-L-histidine and glycyl-L-histidylglycine are described. Chemical-shift data indicate that, at the molecular level, the glycyl ammonium and the histidyl imidazolium groups are titrated over the same pH range, with the acidity of the imidazolium group some 8 to 10 times that of the glycyl ammonium group, depending on the peptide. The lysyl ammonium group of Gly-His-Lys is much less acidic and is titrated over a higher pH range. Microscopic and macroscopic acid-dissociation constants were determined from chemical-shift data for each of the peptides. It is shown how microscopic formation constants for protonated metal complexes of these ligands, which are being used increasingly as models for the binding of metal ions by proteins, can be calculated from the macroscopic formation constants and the microscopic acid-dissociation constants. The acid-base chemistry of Gly-His-Lys is discussed with respect to its recently discovered biological activity.


Glutamine active site of formylglycinamide ribonucleotide amidotransferase. 1. Labeling of the enzyme with iodoacetate. A two-step method for labeling the glutamine active site of formyglycinamide ribonucleotide (FGAR) amidotransferase from chicken liver has been developed in which reaction of all other reactive groups with unlabeled iodoacetate is followed by specific labeling of the glutamine site with radioactive reagent. A study of the reaction as a function of duration, temperature, and pH of the incubation as well as concentration of iodoacetate has revealed that two nonessential groups of the enzyme react in the presence of glutamine and that this modified enzyme is relatively resistant to further carboxymethylation. When this modified enzyme was incubated with radioactive iodoacetate in the presence of FGAR, ATP, and Mg2+ after removal of glutamine by dialysis, about 1 mol of radioactive iodoacetate was incorporated per mol of enzyme with inactivation. This method permits labeling of the active site for glutamine without the use of glutamine analogues.


Solvent effects on thiamin-enzyme model interactions. I. Interactions with tryptophan. The solvent polarity dependence of the interaction between thiamin and tryptophan was studied by spectrophotometric methods. The ultraviolet (UV) data clearly indicate that the interaction is weakened when the complex is transferred from water to aqueous ethanol or aqueous dioxane. The interaction of thiamin and tryptophan could also be detected by fluorescence-quenching studies (excitation of tryptophan at 287 nm, maximum emission at 348 nm). Appropriate treatment of the quenching data allowed dissection into static and dynamic contributions. A pyrimidine derivative related to thiamin, both in its neutral and protonated states, was shown to interact with tryptophan by fluorescence techniques, but not by UV. A thiazolium model was shown to interact with tryptophan by UV but was an inefficient quencher of the tryptophan fluorescence. Theoretical models are presented to explain the solvent dielectric constant dependence of the association constant between tryptophan and thiamin. Both electrostatic and dispersion forces are found to contribute to the stability of the complex.


NADPH-cytochrome P-450 reductase from rat liver: purification by affinity chromatography and characterization. (NADPH)-cytochrome P-450 reductase was purified to apparent homogeneity by a procedure utilizing nicotinamide adenine dinucleotide phosphate (NADP)-Sepharose affinity column chromatography. The purified flavoprotein has a molecular weight of 79 700 and catalyzes cytochrome P-450 dependent drug metabolism, as well as reduction of exogenous electron acceptors. Aerobic titration of cytochrome P-450 reductase with NADPH indicates that an air-stable reduced form of the enzyme is generated by the addition of 0.5 mol of NADPH per mole of flavin, as judged by spectral characteristics. Further addition of NADPH causes no other changes in the absorbance spectrum. A Km value for NADPH of 5 micron was observed when either cytochrome P-450 or cytochrome c was employed as electron acceptor. A Km value of 8 +/- 2 micron was determined for cytochrome c and a Km of 0.09 +/- 0.01 micron was estimated for cytochrome P-450.


Isotope effect studies of the role of metal ions in isocitrate dehydrogenase. Pig heart NADP+-dependent isocitrate dehydrogenase requires a metal ion for activity. Under optimum conditions (pH 7.5, Mg2+ present), the carbon isotope effect is k12/k13 = 0.9989 +/- 0.0004 for the carboxyl carbon undergoing decarboxylation and hydrogen isotope effects are VmaxH/VmaxD = 1.09 +/- 0.04 and (Vmax/Km)H/(Vmax/Km)D = 0.76 +/- 0.12 with threo-D,L-[2-2H]isocitric acid. Deuterium isotope effects measured by the equilibrium perturbation technique under the same conditions are VH/VD = 1.20 for the forward reaction and 1.02 for the reverse reaction. Under these conditions the rate-determining step in the enzymatic reaction must be product release. Dissociation of isocitrate from the enzyme-isocitrate complex and the enzyme-NADP+ complex must be two or more orders of magnitude slower than the chemical steps. The catalytic activity of the enzyme is about tenfold lower in the presence of Ni2+ than in the presence of Mg2+. The carbon isotope effect in the presence of Ni2+ at pH 7.5 is k12/k13 = 1.0051 +/- 0.0012 and the hydrogen isotope effects are VmaxH/VmaxD = 0.98 +/- 0.07 and (Vmax/Km)H/(Vmax/Km)D = 1.11 +/- 0.14. Thus, the rate decrease caused by substitution of Ni2+ for Mg2+ must result from the effects of metal on substrate and product binding and dissociation, rather than effects of metal on catalysis. However, a more detailed analysis of the carbon isotope effects reveals that there is also a large metal effect on the rate of the decarboxylation step, consistent with the view that the carbonyl oxygen of the oxalosuccinate intermediate is coordinated to the metal during decarboxylation.


pH-dependent Soret difference spectra of the deoxy and carbonmonoxy forms of human hemoglobin and its derivatives. The transition from deoxy to oxystructure of hemoglobin A (Hb) is accompanied by the breaking of the salt bridges formed by C-terminal residues in deoxy-Hb. This, in turn, changes the state of the heme. The switch between these different allosteric forms can be followed by changes in the optical absorbance spectra (Perutz, M. F., Ladner, J. E., Simon, S. R., and Ho, C. (1974), Biochemistry 13, 2163). Using difference spectroscopy in the soret region, pH-dependent spectral changes of Hb and its derivatives (carbamylated at both the alpha-NH2 groups, alpha2cbeta2c; N-ethylsuccinimide hemoglobin, NES-Hb) in their deoxy and carbonmonoxy forms were measured. From these measurements, the pK values of histidine-146beta and valine-1alpha in deoxy-Hb were determined to be 8.6 +/- 0.2 and 7.7 +/- 0.1, respectively. In carbonmonoxy-Hb a pK value of 6.3 +/- 0.1 was found.


Acid-catalyzed hydration of reduced nicotinamide adenine dinucleotide and its analogues. The rate of the primary acid modification reaction of 1,4-dihydronicotinamide adenine dinucleotide (NADH) and 1,4-dihydro-3-acetylpyridine adenine dinucleotide (APADH) and their analogues has been studied over a wide pH range (pH 1-7) with a variety of general acid catalysts. The rate depends on [H+] at moderate pH and becomes independent of [H+] at low pH. This behavior is attributed to substrate protonation at the carbonyl group (pK of NADH = 0.6). The reaction is general acid catalyzed; large solvent deuterium isotope effects are observed for the general acid and lyonium ion terms. Most buffers cause a linear rate increase with increasing buffer concentration, but certain buffers cause a hyperbolic rate increase. The nonlinear buffer effects are due to complexation of the buffer with the substrate, rather than to a change in rate-limiting step. The rate-limiting step is a proton transfer from the general acid species to the C5 position of the substrate. Anomerization is not a necessary first step in the case of the primary acid modification reaction of beta-NADH, in which beta to alpha anomerization takes place.


Phosphatidic acid distribution on the external surface of mixed vesicles. A new method has been developed to detect the distribution of phosphatidic acid on the external surface of mixed phospholipid vesicles. Some positive dyes undergo large absorbance changes when the spatial separation between two or more dye molecules is smaller than a critical distance. When these dyes interact with mixed phospholipid vesicles, the absorbance changes may be utilized to calculate the amount of phosphatidic acid molecules which, on the external surface, occupy nearby positions not exceeding the critical dye distance, i.e., the amount of paired phosphatidic acid molecules. This amount was found to be higher than that calculated by statistical methods, indicating that phosphatidic acid molecules tend to be associated, in spite of the electrostatic repulsion between negative groups. The dependence of the amount of paired phosphatidic acid molecules on the pH, phosphatidylcholine:phosphatidic acid ratio, and temperature has been also analyzed.


Duplex formation of a nonionic oligo(deoxythymidylate) analogue (heptadeoxythymidylyl-(3'-5')-deoxythymidine heptaethyl ester (d-(Tp(Et))7T)) with poly(deoxyadenylate). Evaluation of the electrostatic interaction. The heptaethyl ester of heptadeoxythymidylyl-(3'-5')-deoxythymidine (d-[Tp(Et)]7T or d-T8-Et) has been prepared by chemical methods. The material, consisting of a mixture of diastereoisomers, forms a 1:1 complex with (dA)n in neutral aqueous buffer; this interaction is virtually independent of ionic strength. The octamer triester does not bind to (dA)n-(dT)n, and it interacts with (rA)n only at low temperatures. By cochromatography with (dA)n on Sephadex G-50, d-T8-Et fractions with different binding affinities for the polyadenylates were obtained. This heterogeneity in binding affinity is ascribed to the diastereoisomerism of d-T8-Et. Enthalpies of dupoex formation were determined by the concentration variation method. At 0.1 M sodium ion concentration, the enthalpy of binding of the various d-T8-Et fractions to (dA)n is essentially invariant (-8.1 kcal/mol of base pairs at 0 degrees C to -8.6 kcal at 25 degrees C) and 1.6 kcal/mol of base pairs more negative than the enthalpy of binding of the phosphodiester analogue, d-(Tp)7T, to (dA)n (-6.8 kcal/mol of base pairs at 11 degrees C). This difference is the electrostatic contribution to the enthalpy of duplex formation, arising from the interstrand electrostatic repulsion and the intrastrand repulsion in d-(Tp)7T. The entropy of binding to (dA)n is more negative for the octamer triesters than for the diester analogue, and is different for the various d-T8-Et fractions. This is interpreted in terms of varying degrees of restriction of rotational freedom for the ethyl substituents upon double helix formation.