Prolactin release inhibiting and stimulating factors in the hypothalamus. Catecholamines, especially norepinephrine and dopamine, as well as GABA extracted from porcine hypothalamic tissue, were found to possess PIF activity in vitro. However, more work is needed to determine whether or not the effects of GABA or catecholamines on prolactin release are physiological or pharmacological. Until such studies are completed and until the chemical nature and biological roles of other substances with PIF activity found in the hypothalamus are clarified, no conclusion as to the nature of the physiological inhibitor of prolactin release should be made.


Atypical (relaxant) response to histamine in cat bronchus. Histamine, 2-methylhistamine (a specific H1-receptor agonist), 4-methylhistamine (a specific H2-receptor agonist), isoprenaline, bradykinin, prostaglandin E1, E2, and F 2alpha  induce relaxation of carbachol-contracted isolated cat bronchial strips and tracheal chains. Bovine SRS-A contracts bronchus but not trachea. Histamine-induced relaxation of cat bronchus is not blocked by mepyramine (a specific H1-receptor antagonist); metiamide or burimamide (specific H2-receptor antagonists); propranolol ( a beta-adrenoceptor blocker) and indomethacin (a PG-synthetase inhibitor) suggesting non-participation of H1,H2-histamine receptors, beta-adrenoceptors (catecholamine release) and prostaglandin release in histamine-induced broncho-relaxations in the cat. The existence of an atypical histamine response, resistant to both H1- and H2-receptor antagonists is thus established in cat bronchus.


Tick-borne diseases in the United States: Rocky Mountain spotted fever and Colorado tick fever. A review. The historical, clinical, ecological, and epidemiological features of Rocky Mountain spotted fever and Colorado tick fever, the two important tick-borne diseases in the United States, are reviewed. Rocky Mountain spotted fever, once considered a disease of the past, has again become a measurable public health problem. Its nationwide incidence has steadily increased since 1960 and has reached record proportions in 1976. The various factors responsible for this trend as well as for the mortality rates, which in spite of availability of effective antibiotics ranges from 5 to 10%, are discussed. Education of the public about ticks and their potential role as vectors of Rickettsia rickettsii and/or Colorado tick fever virus, and about the clinical manifestations of Rocky Mountain spotted fever, is considered the best means for preventing high incidence and mortality from these diseases.


Influences of blood digestion on the development of Plasmodium gallinaceum (Brumpt) in the midgut of Aedes aegypti (L.). Blood digestion of Aedes aegypti and development of Plasmodium gallinaceum were shifted against each other by giving the mosquitoes two consecutive blood meals. In this way the parasites were exposed to an environment where blood digestion was more advanced than in single blood meals. This procedure had an inhibiting effect on oocyst production when the two blood meals overlapped; an enhancing effect when they were well separated. The results are explained by the action of trypsin-like proteases on the parasites and indicate that plasmodia 0-10 h after blood meal are more sensitive to the enzymes than later stages of the parasites.


Regulation of aerobic fermentation in protozoans. VI Comparative biochemistry of pathogenic and nonpathogenic protozoans. We have investigated the oxidation of carbohydrate by several protozoan organisms. The oxidation is incomplete and results in a mixture of organic acid and carbon dioxide. The phosphofructokinase and pyruvate kinase, enzymes normally under strict metabolic regulation, are not subject to the normal feedback inhibition or activation mechanisms found in other cells. Moreover, our investigations and those of others support the hypothesis that a primary pathway for glucose metabolism is to phosphoenolpyruvic acid and then to oxalacetic acid with subsequent reduction to succinic acid.


Physiologic interactions between L-proline and D-glucose in Leishmania tarentolae, L. donovani and Trypanosoma scelopori culture forms. L-proline is more completely catabolized by Leishmania tarentolae and Trypanosoma scelopori than by L. donovani. In the two former organisms the activity of 14CO2 derived from L-proline-14C was as high or higher than that derived from D-glucose-14C; in L. donovani more 14CO2 is derived from D-glucose-14C than from L-proline-14C. Addition of unlabeled D-glucose to cells incubated with L-proline-14C resulted in increased 14C-activity of TCA-soluble fractions of L. tarentolae and T. scelopori; 14C-activity of 5% TCA insoluble fractions of these cells remained unchanged. Some of the increased 14C-label found in the soluble fraction was in glutamate and aspartate. This increased activity in glutamate and aspartate was accompanied by a decrease in alanine-14C in the free amino acid pool. These results suggest that there are complex physiological interactions between glucose and proline in the metabolism of L. tarentolae, L. donovani and T. scelopori. In addition, proline appears to have a more central role in the amino acid metabolism of L. tarentolae and T. scelopori whereas glucose may be more significant in L. donovani.


Tricarboxylic acid and glyoxylate cycles in the Leishmaniae. Cell-free extacts of four species of Leishmania (L. brasiliensis, L. donovani, L. mexicana and L. tropica) have been shown to contain all enzymes of the tricarboxylic acid cycle. However, the activity of citrate synthase is so low that it is doubtful whether this pathway is of significance in the metabolism of carbohydrate substrates. All four species show the presence of the two enzymes (isocitrate lyase and malate synthase) characteristic of the glyoxylate bypass and glyoxylate is present in cell-free preparations. The isocitrate lyase is relatively insensitive to phosphoenolpyruvate (PEP). The glyoxylate cycle in the Leishmaniae, thus, seems to be independent of control by C3 compounds.


Problems in the comparative physiology of some trypanosomatid flagellates. There is considerable evidence that trypanosomatid species vary in their metabolic characteristics, that they vary in the mechanisms by which they control these characteristics, and that a single species may vary metabolically without varying structurally. Studies to date from a number of laboratories also indicate there is still reason to believe that metabolic characteristics of trypanosomatid flagellates, as manifest in culture, are at least correlated (in some cases) with the behavior of the flagellate species in the metazoan host. It appears that our major tasks for the next several years are 1. to discover the extent to which these correlations are manifestations of characteristics required for life in the metazoan host, 2. to discover the extent to which these correlations are manifestations of characteristics which determine infection site within the metazoan host, 3. to discover which if any metabolic control mechanisms contribute to the multiplicity of clinical infections often seen in this group of protozoa, and 4. to discover the critical links between energy metabolism, the control of that metabolism, and life inside a host or host cell.


Testicular venography in the nonpalpable testis. Localization and identification of a nonpalpable testis can be done accurately by testicular venography. The identification of the pampiniform plexus is essential to the localization of the testis by this method. We evaluated 15 patients 3-39 years of age with 21 nonpalpable testes. Fourteen successful testicular venograms were performed showing four retroperitoneal testes, four testes within the inguinal canal, and two testes located in the superficial inguinal pouch. Three nonpalpable testes were thought to be due to true agenesis, and one venogram was performed after prior surgical removal of the testis. Catheterization of the left testicular vein was accomplished with greater ease and accuracy (79%) to the right side (42%).


Polyarteritis nodosa and hepatitis-B surface antigen: role of angiography in diagnosis. two patients with polyarteritis nodosa who presented with vague constitutional systems and hepatitis-B antigenemia are reported. Angiography was used as the primary diagnostic procedure and confirmed the diagnosis in each case. Angiography is a relatively simple and direct means for establishing the diagnosis of polyarteritis nodosa. In these patients, the typical finding of aneurysm formation in multiple organs was observed. Arterial narrowing was also widespread. Multiple renal infarcts are shown in one case, and bronchial arteriography revealed aneurysms and narrowing in bronchial and intercostal arteries in one patient who had a recent pulmonary infarction and a normal pulmonary arteriogram. The relationship of the hepatitis-B antigen and polyarteritis is also emphasized.


Improved quality control of blood acid-base equilibrium using the daily mean of patients' results: a validation study. The efficiency of the daily mean of patients' results as a quality control tool for acid-base equilibrium has been studied in three one-month periods. Results for the first two periods were obtained in a stable patient population using tonometry in one period, direct measurement of PCO2 in the other; the third period corresponded to another patient population in which PCO2 was determined by direct measurement. These comparisons allowed demonstration that both methodology and patient populations influenced the optimal truncation limits used to exclude extreme values. Furthermore, the efficiency of the daily mean in itself was poor. Using a cusum plot of the differences of each daily mean from the monthly mean of the daily means, however, dramatically improved this efficiency. So modified, quality control using the daily mean of patients' results represents a useful tool, since the whole analytic process, from blood sampling to result, is checked.


New method of obtaining cinchophen ulcer in dogs. Cinchophen injected into the cerebral ventricle reacted with the hypothalamus somewhere in the vicinity ventricle, and produced a release of ACTH as indicated by a rise in peripheral plasma 11-OHCS concentration in the dog. The amount of cinchophen injected into the ventricle corresponds to about 1/600 of the dose required to produce the same effect by the intravenous route. Repeated intraventricular injections of cinchophen were effective in producing gastric erosions and ulcers at smaller doses than the intravenous one (1/100 and 1/400). Damage to the gastric wall might be due to a mechanism involving a localized portion of the hypothalamus and/or via a cerebral ventricle. Bilateral truncal vagotomy did not have any effect on chronic ulcer production. The cinchophen ulcerations were accompanied by an increase in plasma corticosteroids. The new experimental technique for producing peptic ulcer in dogs via a central neurohumoral mechanism is described.


Blunted respiratory drive in congenital myopathy. Two patients with clinically mild congenital myopathies presented with chronic respiratory failure. Muscle weakness alone could not account for the respiratory insufficiency since static respiratory pressures were not markedly impaired, ventilation during exercise was normal, and daytime ventilation was normal if ventilatory assistance was provided at night. The ventilatory responses to inhaled carbon dioxide were very low, suggesting that impairment of the central nervous respiratory chemoreceptor contributed to hypoventilation. These patients and others described in the literature suggest that central depression of ventilation may occur more frequently than previously recognized in patients with muscular disorders. Patients with chronic respiratory failure due to central depression of respiratory drive can be effectively managed by assisted ventilation at night.


Fetal respiration. A review.

Fetal respiration. A review. During recent years respiratory movements by the human fetus have been rediscovered. The types of movements have been defined, and their dependence on some physiologic conditions has been described. Pharmacologic agents influence not only the occurrence of the movements but also their rate and depth. A tidal flow of fluid between lung and amnionic sac has been established, which may play an important role in lung development. Demonstration of this route for exchange of water and soluble substances identifies the lung as an organ very likely involved in exchange between fetal compartments. Additionally, the deposition in the lung of the particulate matter contained in amnionic fluid may not be proof of pathologic aspiration as previously thought.


Functional male dyspareunia: a case study. An apparently successful treatment of a male with a long history of dyspareunia is discussed. The case is unique not only because the subject was male but also in that the etiology was functional. The case demonstrates the multicausal nature of dyspareunia as well as the need for an approach utilizing both a psychodynamic and behavioral methodology.


The thin-layer isoelectric focusing of lactate dehydrogenase isoenzymes in rabbit lens parts and in intraocular tissues. Lactate dehydrogenase (LDH) isoenzymes of rabbit lens and other intraocular tissues are separated by thin-layer isoelectric focusing and localized as discrete groups of multiple bands with defined isoelectric points after staining by the tetrazolium method. In the rabbit lens parts, the predominant isoenzymes are LDH-4 and LDH-5. The bands show microheterogeneity, are composed of 2-4 subcomponents, and the pattern shows a distribution of the liver type. The activity of the LDH-4 decreases and that of LDH-5 increases in an order given by the equator, anterior and posterior cortex, and nucleus. LDH-3 remains almost constant in all lens parts. LDH-4 is composed of two subcomponents, one of which, the most cathodic with higher isoelectric point, is almost absent in the lens nucleus. Of the LDH localized in the rabbit intraocular tissues, only the retina shows a pattern of five isoenzymes also of the liver type. In all intraocular tissues LDH-3, -4, and -5 are very prominent, show also microheterogeneity of their isoenzyme bands, and are each composed of 4-6 subcomponents. LDH-1 and -2 show only one isofocused component. Species specificity is shown of the LDH isoenzymes in the rabbit, mouse, dog, and calf lens.


The effectiveness and duration of preoperative antacid therapy. The administration of 10 ml of magnesium trisilicate mixture to premedicated patients, maintains the pH of gastric contents below pH 2-5 during subsequent general anaesthesia. This effect was sustained for over seven hours--the longest anaesthetic time studied. No antacid supplementation is required to offer protection from acid aspiration during emergence and initial recovery from general anaesthesia.


The effect of hyoscine and atropine on the lower oesophageal sphincter. The effects of intravenous hyoscine 0-4 mg and atropine 0-6 mg on lower oesophageal sphincter tone were studied in normal human subjects. Hyoscine and atropine both decreased the lower oesophageal sphincter (L.O.S) pressure by approximately 11 cm H2O (p less than 0-01). There was also an increased incidence of reflux as seen by an indwelling pH electrode in the lower oesophagus. These findings are relevant to the preoperative preparation of patients presenting for emergency obstetrical anaesthesia; since gastro-oesophagus reflux and pulmonary aspiration of acid gastric content continues to be a significant cause of morbidity and mortality.


An anaphylactoid reaction to gallamine triethiodide. A patient suffered profound anaphylactoid reaction during anaesthesia. Intradermal skin testing confirmed the clinical impression that gallamine caused the reaction. The method of testing is discussed. Previous reports of hypersensitivity to the drug are reviewed, and the use of adrenaline, antihistamines and corticosteroids in patient management are considered.


[The Bain anesthetic system in facial surgery]. The BAIN circuit was studied in 11 patients undergoing maxillofacial surgery, with no respiratory deficit, and under spontaneous and assisted ventilation, with a rate of flow of gas of 80, 100, 120, 140 ml/kg/min. From the results it could be concluded that this circuit should be used with a flow of at least 140 ml/kg/min, in assisted ventilation, in order to avoid any retention of CO2. Capnographic follow-up enabled better regulation of the flow rate necessary.


[Anesthesia with continuous infusion of alfatesine and phenoperidine. Uses in anesthesia of aged subjects in visceral surgery]. Anaesthesia was administered to one hundred and fifty eight patients by continuous infusion of a mixture of Alfatesine and phenoperidine. The patients were divided on two groups: group A consisted in 96 patients undergoing abdominal surgery and group B of 62 cases of various types of surgery, mainly orthopedics. The average age was 63 years (range 16-96). The operative risk scored 6 or more in 71 cases. The length of operation averaged 151 minutes (S.D. +/- 15). The mixture made of alfadione 25 ml and phenoperidine 5 mg in a glucose 5 per cent 250 ml solution was administered by mechanical pump. The induction dose was 50 ml of the mixture for patients under 50 years (rate 10 ml per minute), 40 ml per patients from 50 to 70 years (5 ml per minute), and 30 ml for patients over 70 years (5 ml per minute). The maintenance dose was adjusted to weight and age and ranged from 0,11 to 0,15 ml/kg/h for alfadione and from 0,022 to 0,030 mg/kg/h for phenoperidine. Routine tracheal intubation and artificial ventilation were performed in group A. The results are studied in relation to the effectiveness of the anaesthesia mixture, its side effects and influence on recovery. Generally, the results are good and emphasize the value of the technic in abdominal surgery for elderly patients. The methods of application are discussed in terms of medical background.


[Action of dibencozide on nitrogen metabolism in immediate and long-term postoperative resuscitation]. The catabolic orientation of the immediate post-aggression phase is aggravated in neurosurgery by the almost routine prescription of corticosteroids. This emphasises the value of any treatment which might limit this orientation. The authors report their experience with the use of dibencozide, with its known facilitating action upon nitrogen assimilation, in the absence of any side effects.


[Percutaneous catheterization of the subclavian vein and/or the Pirogoff angle]. The approach to the sub-clavian venous axis being carried out blindly, the difficulties encountered oblige one: - to avoid the danger (pleural dome in particular); - to guide the catheter along the sub-clavian axis (and not in the jugular vein) and therefore to know the anatomical landmarks and a precise method. A variant of the CARLE technique, that which is proposed is based on no other anatomical argument than the direction of the sub-clavian axis and of its junction. The puncture site is higher and more external, a guiding finger shows the pathway in such a way as to try and leave the dangers behind the pathway of the needle. The obligatory long tunnelization of the catheter, becomes an advantage (fights against the danger of infection) to be added to the already known advantages of this pathway.


[A case of acute ischemia of the extremities in disseminated intravascular coagulation in an infant]. The authors report a case of diffuse intravascular coagulation occurring in a 15 day old infant suffering from several congenital malformations (meningocoele, megacolon and bilateral hydronephrosis). During reparative surgery, acute and symmetrical of the lower limbs developed in a context of shock and respiratory distress. Associated with a coagulopathy, it progressed towards the death of the child on the second postoperative day. The authors review the cases of gangrene of the extremities with diffuse intravascular coagulation occurring in the young child found in the literature, and discuss the factors which favourise its development.


[Early respiratory involvement in burns. Mechanism and prognostic significance]. A retrospective study, on 87 flame burn patients, of arterial Pa02, chest X-ray and lactic dehydrogenase isoenzyme III revealed the very early onset (before the 24th hour) of severe respiratory problems. This involvement, with a severe prognostic significance, appears to be much more closely related to the extent of the cutaneous burn than to the inhalation of fumes or vapours, and seems to fall into the more general category of "post-aggression lung".


[Ventilatory disorders in the acute period of tetraplegia of traumatic origin]. Out of a total of 30 cases of traumatic tetraplegia with the lesion situated from C1 to C8 seen during the acute phase in the department of Professor JUDET, 8 posed no respiratory problems, whilst the others suffered lobar or pulmonary atelectasis in 13 cases, retention of bronchial secretions with secondary infection in 6 cases and progressive hypoxaemia in 3 cases. The first two types of complication are mechanical in origin and are directly related to the neurological problem. The third type is of more complex pathogenesis, combining water retention, hypoproetinaemia and secondary infection.


[Atypical pulmonary embolism associated with inter-auricular communication]. A case of massive pulmonary embolism at a patient with undetected atrial defect is reported. The authors discuss the difficulties of establishing a proper diagnosis when the right heart pressure is not raised and when a large emboliser is well tolerated. Angiography confirmed the diagnosis and the patient was successfully treated with embolectomy followed by ligation of the inferior vena cava.


[The cerebro-cardiac syndrome in neuro-traumatology]. Head trauma is a possible cause of E.C.G. modifications originating in the brain and unresponsive to pure symptomatic cardial therapy. On the other hand, these perturbations react in a favourable way to treatment aimed at protecting the heart against descending nociceptive influx caused by brain injury. This report shows the results of a retrospective electrographic study of 220 unoperated patients with head injuries aged 15 to 30 years. A correlation is established between E.C.G. findings and depth of coma. The authors discuss their findings and suggest an etiologic pathology based on clinical and experimental factors.


Medullary carcinoma of the thyroid gland. Out of the discovery of concurrent multiple endocrine neoplasms has evolved the concept of multiple endocrine adenomatosis (MEA1 and MEA2). Medullary carcinoma of the thyroid gland is the most constant facet of MEA2 and is derived from C-cells of the neural crest. These cells, resembling parafollicular cells of lower animals, elaborate calcitonin which acts as a sensitive signal of the presence of the tumor. Ninety per cent of MCT occurs sporadically; in 10% the tumor presents as an atuosomal dominant trait. Other endocrinopathies, especially pheochromocytomas, are present in 70% of cases. The lesions are "cold" on iodine radioisotope scan. On microscopic examination, the appearance of amyloid is characteristic. Regional lymph node metastasis occurs early. The tumor deserves appropriate aggressive management. Surgical therapy should begin early and vigorously with the minimum procedure being total thyroidectomy. Frequent lymph node metastasis speaks for the need for regional neck dissection extended into the superior mediastinum. The search for, and the treatment of, the frequently associated endocrinopathies is essential. Pheochromocytoma must be suspected and eradicated before treatment of the thyroid tumor. A genetic workup should be included.


Extrinsic neural influences on gastrointestinal motility. The gastrointestinal tract is capable of carrying on all its major functions after all extrinsic nerves have been cut. This automaticity is due to the local nervous mechanisms in the walls of the gastrointestinal tract and the inherent properties of the smooth muscles in its walls, and gastrointestinal hormones. All levels of the central nervous system have been shown, by stimulation and ablation studies, to influence the motility of the entire gastrointestinal tract. Throughout many cerebral areas there are loci which, on stimulation, exert both inhibitory, and less often, excitatory influence on gastrointestinal motility. These influences are mediated by sympathetic and parasympathetic visceral efferent nerves, as well as humoral agents from the neurohypophysis. Thus, they impose an influence of higher control on the automatically efficient intrinsic motility. They are guided by information received from visceral, cranial, and somatic afferents, as well as intracerebral, or psychic inputs. Under normal circumstances they only influence gastrointestinal activity as will best afford the optimal functioning of a performance done automatically with efficiency and finesse.


The switch process in manic-depressive psychosis. Bipolar manic-depressive illness is a chronic disease in which patients experience recurrent episodes of mania and depression. Patients often change from a nonverbal, retarded depression of many months' duration to a hyperactive, psychotic, manic condition during the switch. The time required for the switch from depression into mania varies from 5 minutes to a couple of days. Just before it happens, pateints experience marked insomnia and decreased rapid eye movement sleep. It is hypothesized that specific changes in brain monoamine metabolism precede the switch. Alterations in neurotransmitter metabolites, as measured in urine and cerebrospinal fluid, may precede and accompany it. The switch into mania can be precipitated by environmental stresses or by drugs that act by increasing functional brain monoamines. Drugs that reverse the manic state all share the common property of affecting biogenic amines. The switch  into mania is viewed in the context of a longitudinal cyclic process and may be further studied with specific pharmacologic agents that block drug-induced maniclike states in man.


Ecology of Keystone virus, a transovarially maintained arbovirus. Our studies in the Pocomoke Cypress Swamp of Maryland have shown that KEY strain of CE is endemic and is carried by the floodwater mosquito A. atlanticus. The virus is transmitted transstadially in nature, as evidenced by our recovery of virus from larvae and males of this species. Serologic evidence, both here and elsewhere, indicates that vertebrates are infected with KEY, but their role in the transmission cycle remains unknown. We have found several animals, for example, the gray squirrel, that are potential vertebrate reservoirs for the virus. Gray squirrels possess antibodies to KEY in nature, are known to be fed upon by A. atlanticus females, and have been shown to circulate a high-titered viremia after experimental inoculation. Evidence from 1974 collections, however, indicates that A. atlanticus females ingested only a single blood meal during the period when adults were active. We will not be able to assess the relative importance of the vertebrate and mosquito cycles until much more work has been performed on vector-reservoir-virus dynamics.


Transovarial transmission of Rickettsia-like microorganisms in mosquitoes. The wolbachiae found in Culex pipiens and the Tafahi strain of the A. scutellaris group are small rickettsia-like symbionts of the gonads. They are extrachromosomal self-replicating units that are vertically transmitted through the ovaries. Their presence in the only two groups of mosquitoes known to exhibit incompatibility, the fact that they are found in only the Tafahi strain, and the loss of incompatibility after removal of Wolbachia in C. pipiens are compelling evidence for the role that Wolbachia plays in incompatibility.


[Nitrates and nitrites in plants].

[Nitrates and nitrites in plants]. The formation of aminoacids and proteins from the nitrogen which enters the roots as nitra t involves a complex reaction requiring energy. The first step requires a metalloflavoprotein, the nitrate reductase and the successive intervention of NADPH, FAD and reduced molybdenum which transfers electrons to nitrate and reduces it to nitrite. The following steps involve NADPH, FAD, Copper, Iron and Manganese, the last steps of the successive reductions being ammonia, needed for the aminoacids synthesis. The activity of the different enzymes are under the dependence of the genetic equipment of the plant, of the nitrogen and oligo-element nutrition and of the different factors acting on the photosynthesis.


[Formation of nitrosamines in the digestive tract]. Nitrosamines are carcinogenic compounds synthetized from amines and nitrites or nitrates, if nitrates in the reaction medium may be reduced to nitrites. Nitrosation is determined in the digestive tract of several species of laboratory animals. Two physiochemical factors appear to determine in vitro nitrosamine formation: the type of amine and the medium pH. The property of secondary amines to nitrosate is inversely related to amine basicity (checked in vivo), and it increases with the medium acidity. In vitro studies show that different types of bacteria can, even at neutral pH, catalyze nitroamine formation from their precursors. However, the role of digestive tract microbial flora in nitrosamine synthesis in the gut cannot be affirmed due to lack of in vivo studies.


[Metabolism of nitrates-nitrites].

[Metabolism of nitrates-nitrites]. Once the pair nitrate-nitrite--in quantity respectively set by the ingestion level or transformation level by intestinal bacteria--has entered through the intestinal mucosa, it may react with active biochemical groups. Nitrite, owing to its high oxido-reduction potential, may induce the oxidation of a large number of compounds, as for example the Fe++ heme-Fe+++ hemine system, reduced cytochromes-oxidized cytochromes system, etc. If the presence of nitrite in blood is not clearly established, this is due to the nitrite high chemical reactivity. Moreover, a transformation by the tissues of nitrates into nitrites after a nitro-reduction is quite possible.


[Effect of nitrites and nitrates on various aspects of vitamin nutritional status]. Nitrites--and sometimes nitrates--decrease the biological availability of dietary vitamins in several animal species. 1. Numerous studies show that ingested nitrites decrease the stock of liver vitamin A in nonruminants (Rat, Pig, Chicken); the effect of nitrates is less pronounced even lacking. In vitro, experiments allow to think that vitamin A and beta-carotene can be destroyed by nitrites in the diet and/or in the gastrointestinal tract. 2. Some recent works--those of Lhuissier particularly--show that nitrites can affect some vitamins of B group and their metabolism. Thiamine and vitamin B6 contents of several tissues decrease when nitrites are fed to the Rat. In the case of thiamine, the result could be partially explained by destruction of the vitamin in the diet and may be in the gastrointestinal tract. No such explanation seems to be possible in the case of vitamin B6.


pH of blood and aqueous in patients with glaucoma. pH estimation of blood was carried out in 37 normal patients and 43 patients with chronic simple glaucoma. pH of blood did not show any statistical significant difference in the 2 groups. pH of aqueous also was noted in 8 patients with glaucoma and 8 normal patients and no significant difference was noted.


Bradshaw lecture, 1976. Thyroid medullary carcinoma. The main characteristics of medullary carcinoma of the thyroid are its non-follicular histological appearance, resulting from its origin from the parafollicular C cells, its secretion of calcitonin, providing a relatively simple diagnostic test, and its equal sex incidence, in contrast to all other diseases of the thyroid. Sporadic cases are seen and it occurs in familial groups, with autosomal dominant inheritance, when it is associated with phaeochromocytoma and parathyroid hyperplasia to form the second type of multiple endocrine adenomatosis (MEA2). These last features make it necessary in every case of medullary carcinoma of the thyroid to examine other members of the family and to investigate the possibility of concomitant adrenal and parathyroid disease. The priorities of treatment when these are present and the indications for total thyroidectomy are discussed.


Determination of serum creatinine by reaction with methyl-3,5-dinitrobenzoate in Methyl Sulfoxide. Creatinine in serum is determined with a new reagent system consisting of methyl-3,5-dinitrobenzoate and tetramethyl ammonium hydroxide in 50% methyl sulfoxide. The method shows excellent correlation with manual and automated alkaline picrate procedures and has comparable sensitivity. The proposed method has advantages over the dinitrobenzoyl chloride assay system in terms of sensitivity, reagent stability and precision. The day-to-day coefficient of variation is 2.9-3.8%, while within day is 1.5-2.1%. The standard curve is linear beyond 20 mg/dl creatinine. Compared to the picrate method, the proposed assay is less than one half as susceptible to a combination of known interfering agents. Based on the present studies, it is recommended as an excellent alternative to the commonly used picrate procedures.


[Variation of the anhidrotic activities of anticholinergics with different routes of administration (author's transl)]. Anhidrotic concentrations 50 of four anticholinergics were determined in mice using an original skin palmar conductance method. Intra-peritoneal, intra-palmar and topical routes were compared. Relative anhidrotic activities according to the mode of administration of the different anticholinergics showed definite differences, e.g. hydroxyzine, which was the less active per i.p. route, was the most active per topical route. The method is likely to be a useful test for selecting the most active anticholinergic and its most efficient route of administration for the treatment of hyperhidrosis.


Human pancreatic alpha-amylase. II. Effects of pH, substrate and ions on the activity of the enzyme. Purified human pancreatic alpha-amylase (alpha-1,4-glucan 4-glucano-hydrolase, EC 3.2.1.1) was found to be stable over a wide range of pH values (5.0 to 10.5) with an optimal pH for the enzymatic activity of 7.0. The Michaelis constant of the enzyme at optimal pH and assay conditions was found to be 2.51 mg per ml for soluble starch. Halide ions were required for the activity of the enzyme whereas sulfate and nitrate were not. The order of effectiveness of activation was found to be: Cl- greater than Br- greater than I- greater than F-. Calcium and magnesium were activators at concentrations of 0.001M and 0.005M, respectively, but exhibited inhibitory effects at concentrations higher than 0.005M. At 0.01M ethylenediamine tetraacetic acid (EDTA) concentration the enzymatic activity upon seven min incubation, was inhibited up to 96%. The inhibition of EDTA and calcium could be reversed upon addition of calcium and EDTA, respectively.


Glucose-6-phosphate dehydrogenase in vitro correlated with in vivo activity and reticulocytosis. In vitro activity of erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) does not always correlate with in vivo hemolytic manifestations. Many of these non-correlations are reviewed and can now be explained on the basis of altered substrate affinity and/or altered inhibition by intracellular metabolites. These alterations are not detected by standard assay conditions. The influence of a young erythrocyte population upon in vitro G-6-PD activity was determined and the lower limit of expected values shown to be raised at least to the mean of an average age erythrocyte population.


[Effects of a vagolytic substance on the circadian rhythm of the ACTH-secreting system in man]. The circadian rhythm of plasma cortisol and urinary 17-hydroxy-corticosteroids has been studied in 6 normal volunteers both in basal conditions and after the administration of a single dose of 30 mg of a banthine derivative (the beta methyl-beta-isopropylaminoethyl ester bromide of xantene-9-carbonic acid, "Pervagal") given orally once a day at different hours (midnight, 4 AM, 8 AM, noon, 4 PM, 8 PM). The vagolytic drug inhibits the cortisol secretion only when administered at 4 PM, 8 PM or midnight, whereas it is ineffective when given at different hours. If don't exist circadian variations of the bio-availability of the drug employed, our results suggest that also in human beings as well as in experimental animals, the cholinergic mechanisms are effective, over all if not exclusively, in starting the circadian activation of the hypothalamo-pituitary-adrenal system.


Chemotaxis of leucocytes: an improved method of direct microscopic observation. Leucochemotaxis was evaluated by direct morphological observation of a cell suspension between slide and coverslip. The chemotactic index was obtained by the ratio of the number of moving leucocytes recorded within an area limited on the slide by circles traced, at the beginning and after a time period of exposure to a gradient of chemotactic factor which was placed in the center of the circle in dry state. The optimal conditions (times of exposure, pH of the medium) and the reproducibility of the assay were investigated on normal blood samples.


Comparative stability of cephalothin and cefazolin in buffer or human serum. A marked loss in potency was observed when cephalothin was incubated for 5 h in human serum at 37 degrees C. Cefazolin was stable under these conditions.


New health practitioners and dermatology manpower planning. To assess the need for dermatologists in the United States, the potential role of new health practitioners in this specialty is considered. Available data on physician extenders in general and informed opinion on dermatologist extenders in particular suggest that specially trained, nonphysician personnel could substantially augment the supply of dermatological services. At present, however, widespread adoption of new staffing patterns appears unlikely. A long-run trend toward greater use of all categories of ancillary personnel in this specialty is expected, and the profession is urged to play an early and active role in this trend's development.


The Environmental fate of three carcinogens: benzo-(alpha)-pyrene, benzidine, and vinyl chloride evaluated in laboratory model ecosystems. Radiolabeled benzo-((alpha)-pyrene, benzidine, and vinyl chloride were evaluated in laboratory model ecosystems for environmental fate, degradation pathways, bioconcentration, and food chain accumulation. The comparative effects of microsomal detoxications were evaluated using the inhibitor piperonyl butoxide. The accumulation and bioconcentration of benzo-(alpha)-pyrene and benzidine were closely correlated with their octanol/water partition coefficients and water solubility. Benzo-(alpha)-pyrene as predicted by these parameters was bioaccumulated to substantial levels in several organisms. Vinyl chloride was not accumulated because of its high volatility.


The effect of beta-adrenoceptor antagonists on the alpha-adrenoceptor blockade produced by phenoxybenzamine. The effect of beta-adrenoceptor antagonists on the irreversible alpha-adrenoceptor blockade produced by phenoxybenzamine was studied in dogs. The pressor effects of adrenaline were revived after the inhibition by the alpha-receptor block by (+/-) propranolol, (-) INPEA, (+/-) MJ 1999 and (+/-) butoxamine. The enantiomers (+) propranolol and (+) INPEA were ineffective in this regard. (+/-) Practolol also did not revive the pressor effect of the amines. The alpha-receptor mediated effect of the amines, in the nictitating membrana-receptor blockade. It is concluded that (1) blockade of the peripheral (beta-2) receptors is essential for the revival of the pressor effects, (2) local anesthetic effect of the beta-antagonists is not involved. Further work using a series of doses of agonists and antagonists of alpha-and beta-receptors is indicated to clarify the nature of this drug-interaction.


[Quantitative composition of the gastrointestinal flora in the young pig]. Studies were conducted into the quantitative composition of the gastro-intestinal flora in clinically intact store pigs. The methods are described in greater detail, followed by presentation of results. In the discussion particular reference is made to literature. Conclusions are drawn regarding the topographic distribution of the various germ groups in the gastro-intestinal tract of the store pig.


[Alterations of cerebrospinal fluid pressure in experimental communicating hydrocephalus. Response of CSF-pressure to increased CO2-tension (author's transl)]. The response of cerebrospinal fluid pressure to increased arterial carbon dioxide tension was examined in 5 control dogs and 7 dogs with experimental communicating hydrocephalus. The cerebrospinal fluid pressure in control animals only rose to 35 mm Hg after elevation of the arterial CO2 tension. In dogs with experimental communicating hydrocephalus, however, a significant rise of intracranial pressure to 60 mm Hg can be demonstrated. This is accompained by a marked simultaneous decrease of cerebral perfusion pressure in hydrocephalic animals. Progression of communicating hydrocephalus can be explained as damage to the cerebral tissue by increased intracranial pressure waves and by ischemia due to low cerebral perfusion pressure.


[Clinical trial with a new anti-epileptic: barbexaclone]. A new anti-epileptic agent (barbexaclone) was tried in 48 patients suffering from epilepsy and presenting a total of 67 types of crises. All the patients were considered "bad cases" because either by the intensity of the epileptic manifestations or by their refractoriness to the usual medications. The results, similar to others already published, could be considered as good for grand mal epilepsy both for those convulsions occurring during either the sleeping or waking hours and suggest further observations in focal crises. Though not considered as a first line medication in petit mal seizuras the drug gave excellent results when used as an adjuvant in the supression of absences and the annulation of convulsant effects of some drugs used in petit mal. No toxic reactions were noted, and the side effects, which were never very intense, tended to disappear in the majority of cases with continued use of the drug.


Generalized glycogenosis in beef shorthorn cattle--heterozygote detection. A preliminary study of acidic alpha-glucosidase in a variety of tissues was carried out in an attempt to develop a test which might be used to detect individuals heterozygous for the genetype associated with generalized glycogenosis in beef Shorthorn cattle. Of the tissues readily available peripheral lymphocytes were chosen as being likely to be the most suitable. It was concluded that, when coupled with genealogical information, assays of alpha-glucosidase in extracts of lymphocytes were useful for identifying heterozygous individuals with a reasonably high degree of probability.


4,4'-dimethylcholesta-7,9,14-trienol is an intermediate in the demethylation of dihydroagnosterol. 1. 4,4'-Dimethylcholesta-7,9,14-trienol is an intermediate in the metabolism of dihydroagnosterol to cholesterol by rat liver homogenate. 2. This triene is reduced by a rat liver microsomal preparation in the presence of NADPH to give 4,4'-dimethylcholesta-7,9-dienol under anaerobic conditions. 3. Reduction of the triene in the presence of [4-3H2]NADPH resulted in the incorporation of 3H into the product. 4. Under aerobic conditions the triene is converted into cholesterol by a rat liver homogenate.


[In vitro studies on parsalmide / bioavailability and protein binding (author's transl)]. The values of the diffusion constants at the different pH-values obtained using Stricker's apparatus, demonstrate that 2-propargyloxy-5-amino-N-(n-butyl)-benzamide(parsalmide, My 46-1) is characterized by a good absorption rate at gastric level and by a high absorption rate in the intestinal tract. The per cent of parsalmide bound to serum proteins, mainly to serum albumin, decreases with increasing concentration of parsalmide. Human serum binds about 55--70%, whereas bovine and equine serum bind about 40--60% of parsalmide at the different concentrations tested. The binding between parsalmide and serum proteins is a weak one: bound parsalmide is therefore set free very easily.


Bufuralol, a new beta-adrenoceptor blocking agent in a series of benzofuran-2-ethanolamines. Part 2: pharmacology. 1-(7-Ethylbenzofuran-2-yl)-2-tert.-butylamino-1-hydroxyethane hydrochloride (bufuralol) is a non-selective beta-adrenoceptor blocking agent which closely resembles propranolol in its properties, including potency. Bufuralol is devoid of alpha-adrenoceptor blocking activity but possesses beta-adrenoceptor agonist activity. beta-Adrenoceptor blocking activity resides mainly in the (-)-isomer though membrane stabilising properties are associated with both optical isomers.


Local and systemic reactions to puncture injuries by the sea urchin spine and the date palm thorn. Puncture wounds were cuased in 9 patients by sea urchin spines and 1 patient by a date palm thorn. All 10 patients developed local inflammatory reactions, which were moderate to severe in 7. Two patients exhibited severe systemic illnesses, and a marked synovitis was present in 2 others. Several of the patients presented as difficult diagnostic problems with signs and symptoms suggestive of an arthritic disease. Six required surgical removal of the foreign body.


Amiodarone-like haemodynamic and non-competitive antiadrenergic properties of a benzoyl-indolizine. 1. 2-Ethyl-3-(4-gamma-di-n-butylaminopropoxy-benzoyl)-indolizine hydrochloride (L 9394) induced in the ananesthetized dog a marked and long-lasting decrease in heart rate together with a transient reduction in blood pressure. 2. L 9394 decreased Robinson's index, an effect which suggests that the substance reduces the oxygen requirements of the heart. 3. L 9394 markedly increased coronary arterial blood flow. 4. L 9394 is endowed with non-competitive antiadrenergic properties. 5. L 9394 did not impair cardiac function since cardiac output and stroke volume increased appreciably during the initial phase of action and did not fall below the control values at any time thereafter. 6. The overall haemodynamic properties of L 9394, which were similar to those of amiodarone, are considered to be potentially valuable for the long-term treatment of angina pectoris.


The effect of mental arithmetic in normotensive and hypertensive subjects, and its modification by beta-adrenergic receptor blockade. 1 The effects of a 5-min period of sustained mental arithmetic upon blood pressure and heart rate were determined in several groups of healthy subjects and hypertensive patients. 2 The arithmetic produced significant increases in heart rate and blood pressure (both systolic and diastolic) in both normotensive and hypertensive subjects. 3 The blood pressure changes were neither attenuated nor enhanced by the prior administration of basis. 4 In subjects habituated to the test the heart rate increase was unaffected by the drugs, but in those less familiar with the test it was usually attenuated. 5 Although the beta1-adrenoceptor selective blocker, metoprolol, caused decreases in baseline values for blood pressure and heart rate similar to those observed with the use of the two non-selective blockrs, it was shown in a double-blind crossover comparison with propranolol that the haemodynamic changes provoked by the mental arithmetic were not less in the presence of beta1-receptor blockade than when both beta1- and beta2-receptors were blocked. 6 These findings suggest that, during beta2-adrenoceptor blockade, the haemodynamic effects of minor mental stress are not exaggerated because of uncompensated alpha-receptor mediated vasoconstriction, such as occurs following adrenaline infusion.


Rupture of base pairing in double-stranded poly(riboadenylic acid)-poly(ribouridylic acid) by formaldehyde: medium chain lenghts. By assuming that the opening of hydrogen bonds due to thermal fluctuations is a very fast step and that the reaction of formaldehyde with the imino or amino group is a slow step, we have constructed a model for the unwinding process of poly(A-U) induced by formaldehyde. The denaturation equation derived from the model is essentially the same as that of the zipper model for moderately long chain lengths. The model predicts the following phenomena which are in agreement with our experimental findings. The rate of unwinding is approximately first order for unfractionated polynucleotides and zero order for fractionated samples. This means that formaldehyde ruptures helical residues sequentially starting from the ends and working toward the center. Our model further predicts that the denaturation rate is linearly dependent on -log[Na+] and pH at low ionic strength and is almost independent of [Na+] and pH at high ionic strength. Spectrophotometric measurements on poly(A-U) were done to confirm our theoretical findings.


Magnetic resonance investigation of ionizable residues at the active site of thermolysin. The details of the pH dependence of the thermodynamic and magnetic interactions of the active-site region of thermolysin in which manganese has replaced the active-site zinc atom and the inhibitor N-trifluoroacetyl-D-phenylalanine have been examined. These show a number of ionizable groups in the active-site region. A cooperative displacement of manganese at the catalytic site is observed as pH is lowered. This appears to be the result of the protonation of histidine-142 and -146 which act as metal ligands. The metal is 50% displaced at pH 6.0. At higher pH values, the environment of the bound manganese changes as a result of the ionization of at least two groups of approximate pKa = 8.5 and 9.5. These values are assigned to tyrosine-157 and to the water molecule which acts as a metal ligand at the active site. The binding behavior of the inhibitor strongly suggests that two molecules of inhibitor bind to the enzyme. The weaker site is competitive with the synthetic substrate FAGLA (furylacryloylglycyl-leucinamide), while the strong site has no effect on FAGLA hydrolysis. This second site is in the vicinity of the active site with a distance of 8 A or less between the trifluoromethyl group and manganese bound at the active site.


Studies on the reactive properties of histone amino groups: reactivities of free histones and histones in chromatin as a function of ionic strength. The reactivity of the amino groups of the five histones towards acetic anhydride has been measured and with the exception of histone IIb2 the reactivities are very similar to those of exposed lysines with an average pK of 9.5. In addition the reactivities of these groups from 0.20 to 1.0 M NaCl and the reactivity of a peptide containing lysines 5, 8, 12 and 16 of histone IV have been measured in chromatin. It is concluded that at the lower ionic strengths the large proportion of the amino groups are buried for both the histones and the region of histone IV studied. Data obtained from the measurement of the reactivity of standard proline compounds and from a pH and ionic strength study indicate that the N-terminal proline of histone IIb2 is exposed.


pH-dependent changes in proton:substrate stoichiometries during active transport in Escherichia coli membrane vesicles. Experiments are presented in which the proton electrochemical gradient (deltamuH+) IN Escherichia coli membrane vesicles (interior negative and alkaline) was measured under a variety of conditions and compared with steady-state levels of accumulation of lactose, proline, D-lactate, and glucose-6-P measured under identical conditions. Accumulation of lactose and proline is proportional to the magnitude of deltamuH+ at pH 5.5, where the pH gradient (deltapH) and the electrical potential (deltapsi) both contribute to deltamuH+, and at pH 7.5, where deltapsi represents the only component of deltamuH+. Moreover, the proportionality constants between deltamuH+ and lactose or proline accumulation indicate that the proton:substrate stoichiometries are 1:1 at pH 5.5 and 2:1 at pH 7.5. Evidence is also presented which indicates that the functional group responsible for the increase in proton:proline stoichiometry has a pK of approximately 6.8. Accumulation of D-lactate and glucose-6-P is directly related to the magnitude of deltapH at pH 5.5, and stoichiometry values of one and approximately 1.7 are obtained for D-lactate and glucose-6-P, respectively, at this pH. At pH 7.5, on the other hand, accumulation of each organic acid bears a linear relationship to deltapsi, and proton:substrate stoichiometries of unity are observed in both instances. The results are consistent with the models discussed by Rottenberg (Rottenberg, H. (1976), FEBS Lett. 66, 159).


Weak acid accumulation in the serosal extracellular compartment of the frog gastric mucosa. The dimethyloxazolidine dione distribution in the extracellular compartments of the frog gastric mucosa was analyzed by washout kinetics. The volumes of the two extracellular compartments, serosal and mucosal, were estimated by inulin washout as 0.435 +/- 0.019 and 0.176 +/- 0.018 microliter/microliter tissue water, respectively. In the serosal extracellular space, significant dimethyloxazolidine dione accumulations of 2.63 +/- 0.25, 2.28 +/- 0.16, and 1.86 +/- 0.08 times that of the bathing media were found for bathing solutions with pH values of 6.9, 7.4, and 7.9 respectively. A high pH of the serosal extracellular fluid by itself could not account for the high values of dimethyloxazolidine dione accumulation. A difference in the total dimethyloxazolidine dione accumulation requires: (a) the existence of differences in the pH values and also the existence of a difference in the diffusion coefficient of the two forms of dimethyloxazolidine dione; or (b), a binding of one of the two forms, i.e., binding of dimethyloxazolidine dione form by fixed charges.


Intracellular pH and the kinetics of Rb+ uptake by yeast non-carrier versus mobile carrier-mediated uptake. The effect of changes in the intracellular pH upon the concentration dependence of the Rb+ uptake by yeast is investigated. It is shown, that the uptake of Rb+ can be described by a mechanism in which the total concentration of primary binding sites at the outer side of the membrane is independent of the intracellular ligand composition and of the membrane potential, and the influx rate constants depend upon the intracellular pH and/or upon the membrane potential. It is argued that the involvement of a mobile carrier mechanism is not likely.


Active transport of L-sorbose and 2-deoxy-D-galactose in Saccharomyces fragilis. Sorbose and 2-deoxy-D-galactose are taken up in Saccharomyces fragilis by an active transport mechanism, as indicated by the energy requirement of the process and the accumulation of free sugar against the concentration gradient. There are no indications for transport-associated phosphorylation as mechanism of energy coupling with these two sugars. The measured sugar-proton cotransport and the influx inhibition by uncouplers suggest a chemiosmotic coupling mechanism. Thus there are at least two different active transport mechanisms operative in Saccharomyces fragilis: transport-associated phosphorylation in the case of 2-deoxy-D-glucose and chemiosmotic coupling in the case of sorbose and 2-deoxy-D-galactose. The differences between the two mechanisms are discussed. Uncouplers do not stimulate downhill sorbose transport in energy-depleted cells and evoke an almost complete inhibition of efflux and of exchange transport. The differences between this sugar-proton cotransport system and similar systems in bacteria and Chlorella are discussed.


Phase transition in charged lipid membranes. Experimental results on the effect of electrostatics on bilayer phase transitions are compared with corresponding data for monolayers and the predictions of electrical double layer theory. The two substantial conclusions which emerge are that: (i) double layer theory based on a continuous surface charge distribution cannot explain all the relevant data, a situation which may be improved by taking into account the discrete nature of the surface charge distribution; (ii) the crystal - liquid crystal phase transition of charged bilayer membranes is always a continuous one which takes place through an intermediate state consisting of both fluid and frozen domains.


Interaction of phosphate with monovalent cation uptake in yeast. The uptake of monovalent cations by yeast via the monovalent cation uptake mechanism is inhibited by phosphate. The inhibition of Rb+ uptake shows saturation kinetics and the phosphate concentration at which half-maximal inhibition is observed is equal to the Km of phosphate for the sodium-independent phosphate uptake mechanism. The kinetic coefficients of Rb+ and TI+ uptake are affected by phosphate: the maximal rate of uptake is decreased and the apparent affinity constants for the translocation sites are increased. In the case of Na+ uptake, the inhibition by phosphate may be partly or completely compensated by stimulation of Na+ uptake via a sodium-phosphate cotransport mechanism. Phosphate effects a transient stimulation of the efflux of the lipophilic cation dibenzyldimethylammonium from preloaded yeast cells and a transient inhibition of dibenzyldimethylammonium uptake. Possibly, the inhibition of monovalent cation uptake in yeast can be explained by a transient depolarization of the cell membrane by phosphate.


Endonuclease activity in nuclei of Physarum polycephalum. Partial purification and characterization. An endonuclease, present in the microplasmodia of Physarum polycephalum, has been partially purified from isolated nuclei by DEAE-cellulose and Sephadex G-75 chromatography. 1. The endonuclease produced single-strand scissions in double-stranded DNA which resulted in the generation of 5'-phosphoryl and 3'-hydroxyl termini. No activity was observed with single-stranded DNA as substrate. 2. The pH optimum was approximately 8.5. 3. Divalent cations were essential for enzyme activity. MnCl2 and MgCl2 gave maximal activity. CaCl2, ZnCl2 or CoCl2 did not activate the enzyme. 4. The endonuclease activity was highly sensitive to monovalent cations. 5. Endonuclease activity was found in two forms after gel filtration: an activity in a homogeneous peak with a molecular weight of approx. 20 000, and an activity that had a heterogeneous molecular weight and which was isolated in a complex with DNA. A possible function of the endonuclease in DNA replication is discussed.


Purification, crystallization and properties of triacylglycerol lipase from Pseudomonas fluorescens. Triacylglycerol lipase of Pseudomonas fluorescens was purified from the crude enzyme by ammonium sulfate precipitation and chromatographies on Sephadex G-75 and DEAE-cellulose. The crystallization of the lipase was successfully carried out. The purified lipase was demonstrated to be homogenous on disc electrophoresis and its molecular weight was calculated to be 32 000 by gel filtration. The optimum pH for hydrolysis of sesame oil was 7.0. The enzyme was stable up to 40 degrees C under the condition of pH 7.0 for 30 min and had more than 80% of the remaining activity between pH 5.0--11.0 at 37 degrees C for 60 min. The lipase was strongly inhibited by iodine and partially inhibited by FeCl3 and N-bromosuccinimide, and showed the most activity on tricaproyglycerol, among the triacylglycerols used.


Two cholesterol ester hydrolases. Distribution in rat tissues and in cultured human fibroblasts and monkey arterial smooth muscle cells. Hydrolytic activity against acetone-dispersed [4-14C]cholesterol oleate has been assayed as a function of pH in seven parenchymal tissues, blood cells, and plasma of the rat, as well as in cultured human fibroblasts and monkey (Macaca nemestrina) arterial smooth muscle cells. Both acid and neutral hydrolytic activities were present in all of these except rat plasma. The pH optima were in all cases close to pH 4.5 and pH 6.8. Acid activity was quite constant from tissue to tissue, while neutral activity varied greatly, being greatest in adrenal, testis, and adipose tissue. Subcellular fractionation of human fibroblasts allowed demonstration that activities at pH 4.5 and pH 6.8 were concentrated in different fractions, apparently lysosomal and polysomal, respectively. It appears most cell types, including fibroblasts and smooth muscle cells, contain two separate enzymes capable of hydrolyzing cholesterol esters. The neutral pH polysomal enzyme, which is especially prominent in certain tissues, may have a function related to the specialized roles of these tissues.


Studies on Tetrahymena membranes. Palmitoyl-coenzyme a desaturase, a possible key enzyme for temperature adaptation in Tetrahymena microsomes. (1) Microsomes from a thermotolerant Tetrahymena NT-1 catalyze the conversion of palmitoyl-CoA to palmitoleate. (2) Palmitoyl-CoA desaturase enzyme requires molecular oxygen and NADH or NADPH as cofactor and its activity is inhibited by cyanide. A pH optimum range 7.0--7.3 is observed. (3) There is a clear break at 30 degrees C and a slight bend around 15 degrees C in the Arrhenius plots of palmitoyl-CoA desaturase activity. (4) After quenching from 39.5 degrees C, at 26 degrees C microsomal membranes show small particle-free areas, when examined by freeze-fracture electron microscopy, indicating the onset of phase separation. Larger smooth areas devoid of membrane-intercalated particles are observed in microsomes at 23 and 15 degrees C. The results support evidence that the thermally induced transition of desaturase enzyme activity in related to the altered membrane properties due to temperature change.


Neutral lipid biosynthesis in Mycobacterium smegmatis. The biosynthesis of neutral lipids in Mycobacterium smegmatis was studied using cell free extracts. Maximum neutral lipid production was obtained when the reaction mixture (400 microliter) consisted of 0.25 M potassium phosphate buffer (pH 7.5), 0.125 mM oleoyl-CoA, 3.75 mM sn-glycerol-3-P, 10 mM MgCl2 and 1.85 mg bovine serum albumin. No magnesium dependency for the acylation of sn-glycerol-3-P was observed. A slight stabilizing effect seemed to occur due to this ion. The enzyme phosphatidate phosphohydrolase, on the other hand, was shown to be magnesium dependent. The activity of this enzyme also appeared to be stimulated by high concentration (0.75 to 1.25 mM) of ATP which enhanced lipid formation at all concentrations tested (0.25 to 3.75 mM). A heat-stable protective factor having a molecular weight less than 16 000 which caused a stimulatory effect on sn-glycerol 3-phosphate acyltransferase activity was found in the cell-free extracts. Preliminary experiments suggest that the factor might be polysaccharide in nature.


Physicochemical and functional properties of Perinereis cultrifera (Grübe) erythrocruorin. Perinereis erythrocruorin has the following physicochemical properties: So20,w = 55S, corresponding to a molecular weight around 2.7-10(6); minimum molecular weight (on the basis of the heme content) 23 700 +/- 500; isoelectric point 5.1; alpha-helix content approximately 40%. At alkaline pH values in the oxygenated form the 55-S molecules dissociate into subunits with a weight average sedimentation coefficient of 3S, corresponding to a molecular weight approximately 35 000. Deoxygenation of partially dissociated samples promotes association of the 3-S subunits into a 9S component. The functional properties of Perinereis erythrocruorin are characterized by a low cooperativity in oxygen binding (n 1/2 = 1.5) at neutral pH. Cooperativity increases reversibly towards both the acid and alkaline pH range, irrespective of changes in molecular weight. This finding, taken together with the ultracentrifuge results, suggests that a subunit may represent the functional unit of the protein. The pH dependence of the oxygen affinity can be accounted for in terms of a single oxygen linked group with a pK of 8.


The pH dependence of the resonance raman spectra and structural alterations at heme moieties of various c-type cytochromes. The pH dependence of resonance Raman spectra were studied for ferrous and ferric cytochromes c, c2, c3, c-551, and c-555. The frequencies of the 1565 cm-1 (ferric) and 1539 cm-1 lines (ferrous) were sensitive to the replacement of the sixth ligand. The titration curve for the 1565 cm-1 line of cytochrome c was parallel with that for the 695 nm band. The pH dependence of the 1539 cm-1 line of ferrous cytochrome c3 suggested the stepwise replacement of the sixth ligand of its four hemes, although such pH dependence was not recognized for the Raman spectra of other ferrous cytochromes investigated. The relative intensities of three Raman lines at 1639, 1587, and 1561 cm-1 of ferric protoporphyrin bis-imidazole complex were changed clearly by the presence of detergents. The relative intensities of the corresponding three Raman lines of cytochromes b5 and c were close to those of the ferric porphyrin complex in the presence and absence of detergents, respectively, suggesting an appreciable difference in their heme environments. Reduced hemin in detergent solution, unexpectedly, gave the Raman spectrum of ferric low spin type.


Nuclear magnetic resonance studies of the denaturation of ubiquitin. The effects of pH, temperature and guanidine hydrochloride concentration on the structure of ubiquitin, a polypeptide which can activate adenylate cyclase and can mimic thymopoietin induced differentiation of prothymocytes, were monitored using nuclear magnetic resonance spectroscopy. This relatively small polypeptide (molecular weight of 8541) exhibits a remarkable stability towards pH and temperature changes. At 7 M guanidine hydrochloride concentration, the structure of ubiquitin is essentially a random coil.


The binding of calcium to fibrinogen: some structural features. Experiments are described which suggest that structural features are related to the existence of three high affinity calcium-binding sites in the fibrinogen molecule. The circular dichroism spectra analysis shows that the binding of calcium to this protein does not entail an overall conformational change. However several calcium-induced protective effects may be observed: 1. At pH 5.0 calcium-free fibrinogen is slightly acid-denatured. This denaturation is counteracted by the presence of calcium, whereas magnesium ions have no effect. 2. A temperature transition shift of 3 degrees C is measured in the presence of bound calcium during thermal denaturation, whereas magnesium ions have no effect. 3. Resistance to proteolysis by plasmin is observed when calcium is bound to fibrinogen. The velocity of the splitting of the earliest plasmin-succeptible bonds is reduced in the presence of calcium, whereas magnesium ions have no effect. It can be concluded from these results that the calcium binding centers are located in a more or less flexible zone of the molecule probably involving the C-terminal part of the Aalpha chain. And that the calcium divalent cation stabilizes a more compact structure of the fibrinogen molecule.


Physicochemical evidence for the existence of two pyridoxal 5'-phosphate binding sites on glutamate dehydrogenase and characterization of their functional role. Kinetic studies of pyridoxal 5'-phosphate binding to glutamate dehydrogenase (EC 1.4.1.3) has provided evidence for two specific binding sites, chemically identified as Lys 126 and Lys 333. Use of protecting ligands permitted the selective modification of only one of these lysines, and showed that (1) Lys 333 modification results in depolymerisation of the enzyme into active hexamers; (2) Lys 126-modified enzyme was 92% inactivated. The residual activity was desensitized to GTP. The inactivation process was cooperative, maximum inactivation occurring as soon as half of the Lys 126 were modified.


The isolation and characterization of a colony stimulating factor from human lung. Serum-free conditioned medium from human lung obtained at autopsy provides a rich source of colony stimulating factor which stimulates granulocytic and macrophagic colony growth in both mouse and human bone marrow. The appearance of the factor is enhanced by endotoxin and inhibited by either puromycin or actinomycin D. Human lung colony stimulating factor is stable at the pH range of 6.5-10 and temperature of 56 degrees C for 30 min. It is resistant to trypsin and neuraminidase but is sensitive to subtilisin, chymotrypsin and periodate. It shows heterogeneity on Sephadex gel filtration with two activity peaks having molecular weight of 200 000 and 40 000, respectively. Upon gel electrophoresis, human lung colony stimulating factor migrates in the alpha-globulin post-albumin region. Using the combination procedures of hydroxyapatite chromatography and preparative polyacrylamide gel electrophoresis a 600-fold purification was achieved with a final specific activity of 6-10(5) units per mg protein. The purified colony stimulating factor is very labile; however, the activity can be stabilized by the addition of gelatin or bovine serum albumin at the concentration of 0.1% and 0.2 mg/ml, respectively.


[Analysis of the activity of Micrococcus luteus endonucleases with respect to gamma-irradiated DNA]. Endonucleases from Micrococcus luteus that induce single-strand breaks in gamma-irradiated DNA have been separated chromatographycally into two groups. The first group involves two different enzymes: AP-endonuclease II (mol. weight 30 000) and AP, UV-endonuclease I (mol. weight 15 000) that recognize alkali-labile lesions in gamma-irradiated DNA and apurinic sites in DNA heated at 70 degrees C, pH 6.08 AP-endonuclease II in cooperation with DNA polymerase from M. luteus and T4 phage-induced polynucleotide ligase is capable of carrying out in vitro complete excision repair of alkali-labile lesins in gamma-irradiated DNA. The second group involves gamma-endonucleases X and Y that act on alkalistable gamma-ray lesions. gamma-endonucleases X and Y can be separated by chromatography on DEAE-cellulose but possess similar properties. Activity of gamma-endonucleases toward gamma-irradiated DNA is inhibited by only heavily UV-irradiated DNA (15 000 ergs/mm2). The data are consistent with the hypothesis that gamma-endonucleases are specific for thymine glycols (t' and tUV) in UV- and gamma-irradiated DNA.


[Properties of human creatine kinase isoenzymes]. Properties of human creatine kinase isoenzymes (MM, MB and BB) are investigated. The most pronounced differences in properties of these isoenzymes are found under their urea inactivation, heat denaturation and the inhibition by rabbit antisera to isoenzymes. Differences in values of the Mikhaelis constant and substrate and pH dependencies are much less pronounced. The presence of ADP stabilizes creatine kinase isoenzymes under conditions of urea and heat inactivation. Properties of hybrid MB isoenzymes are found to be intermediate with respect to MM and BB isoenzymes. A mode of the interaction of M and B subunits in dimeric molecules of creatine kinase isoenzymes is discussed.


[Soluble high molecular weight derivatives of trypsin pancreatic inhibitor. Isolation and properties of dextran-bound pancreatic inhibitor]. A method of isolating preparations of pancreatic inhibitor of trypsin, bound with soluble polysaccharide carriers, is worked out. It is demonstrated that the reaction of a pancreatic inhibitor and cyanuric chloride-activated dextran proceeds for OH groups of tyrosine residues and for-epsilon-NH2 groups of lysine residues. A method is offered of the protection of amino groups with citraconic anhydride for the complete retaining of the inhibitory activity during attachment to dextran. Thermic denaturation of pancreatic inhibitor preparations at pH 4.7 and 97 degrees C is studied. It is found that the modification by 2-amino-4.6-dichloro-s-triazine stabilizes the protein molecule, while the interaction with the matrix of soluble dextran does not carry any contribution to thermostability of the pancreatic inhibitor.


[Comparative kinetic studies of Mg2+-activated hydrolysis of tripolyphosphate and pyrophosphate by inorganic pyrophosphatase]. Computer analysis of P3 and pyrophosphate conversion rate dependence on substrate and metal-activator concentrations reveals the identity of kinetic patterns. Dissociation and catalytical constants for the enzyme combinations with two types of metal-substrates complexes, MS and M2S, at pH 9.0 are by one to two orders of magnitude "poorer" for P3 as compared to PPi. Optimal pH value for the hydrolysis of P3 is by 2 units higher than this for the hydrolysis of PPi. pH profiles for the kinetic parameters in the pH range 8.0--9.5 differ considerably for the two substrates, presumably due to the existence of additional catalitically important ionisations in the reaction with P3.


[Localization of unpaired electrons in molecules of the substrate inhibitors of lysozyme. II. Oligosaccharides]. It has been shown by the method of electron photosensitized transfer that N-acetyl group is the main electron-acceptor group in oligomeres of N-acetyl glucose amine (AGA). In n-AGA molecules (n-3.5) interacting with an electron radical products of the breakage of glycoside bond are observed, their concentration rising with an increase of the chain length. The ionic strength does not affect the photosensitized transfer of the electron in chitin oligomeres. Formation of paramagnetic centres in the molecule penta-AGA depends on the medium pH.


[Solubilization and reconstruction of microsomal AMP-deaminase from skeletal muscles]. Microsomal AMP-deaminase was solubilized by 0.5 M KCl after treatment of microsomal membranes with 0.12 M KCl. Using disc-electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate one major protein component (mol. weight about 90 000) and three minor ones with molecular weights of 110 000, 80 000, and 60 000 were found in the soluble fraction. In addition to proteins, the fraction was found in the soluble fraction. In addition to proteins, the fraction was found to contain a small amount of phospholipids. The deaminase found in the solution may be reconstructed into the membranes at a decrease in KCl concentration, part of enzyme being bound in the inactive form under excess of the soluble fraction. Deaminase binding to the membranes is unaffected by the changes within the pH range of 6.2--7.8 and temperature range of 4--10 degrees C. It is assumed that AMP-deaminase is bound to other membrane components by electrostatic bonds.


[Purification and properties of NADP-reductase of phototropic bacteria Thiocapsa roseopersicina]. The method of purification up to homogenous states and properties of NADP-reductase of purple bacteria Thiocapsa roseopersicina, strain BBS, are described. The molecular weight of NADP-reductase is about 47 000; it is flavoprotein consisting of two subunits. Atebrim and chloromercury bensoate inhibit the activity of NADP-reductase (34% and 33--60%, respectively). The enzyme is specific to NADPH; it catalyzes menadion-reductase reaction, diaphorase reaction of benzyl viologen reduction, oxidation of reduced benzyl viologen in the presence of NADP, reduction of ferredoxin and cytochrome c in the presence of NADPH, but it is not capable to catalyze transhydrogenase reaction.


[Free radical peroxidation of liver mitochondrial and microsomal phospholipids in rat postnatal development]. Activities of both non-enzymic (ascorbate-dependent) and enzymic NADPH-dependent) peroxidation of microsomal and mitochondrial phospholipids are found to be increased in rat liver during postnatal development. It is suggested, that microsomal NADPH-dependent phospholipid dioxygenase forming a chemical modification of membrane polyenic acyls, can be a factor regulating the activities of membrane-linked enzymes under normal physiological processes.


[Some features of cyclic adenosine monophosphate metabolism in mouse liver and hepatoma 22]. The levels of cyclic adenosine monophosphate (cAMP) and two forms of cAMP phosphodiesterase with low (PDE1) and high (PDE2) affinity for the substrate were determined in homogenates from mouse liver and transplanted hepatoma 22. The level of cAMP in the tumour is 3 times lower than that in liver. By te kinetic parameters (Vmax, Km, pH optimum) adenylate cyclase from tumour does not show any significant differences as compared to the liver enzyme; the enzyme from hepatoma is, however, more sensitive to activation by F- ions. The activities of adenylate cyclase in liver and tumour cells are the same. Phosphodiesterases of cAMP from tumour and liver cells are similar in their Km values (3,3-10(-4) M for PDE1 and 2-10(-6) M for PDE2); however, the maximal and real rates of cAMP hydrolysis in hepatoma are much higher than in liver. The fact that both cAMP phosphodiesterase activities have similar dependence on Mg2+ and Ca2+ concentrations, suggests that PDE1 is a latent form of PDE2. In tumour cells the equilibrium between these two forms is probably shifted towards the enzyme with high affinity for the substrate. The results suggest that a decreased cAMP level in hepatoma cells (as compared to the liver) is due to the activation of PDE2.


Comparison of postnatal development of several acid glycosidases in the rat forebrain and cerebellum. Changes of activity of several glycosidases (beta-galactosidase, beta-glucuronidase, N-acetyl-beta-D-glucosaminidase, alpha-D-mannosidase and alpha-L-fucosidase) were compared in the forebrain and cerebellum during postnatal development of the rat. Detailed analysis of the data showed similarities, but also substantial differences in their development in both organs. This is interpreted  as an indication of the presence of common regulatory mechanisms, as well as of other factors which differently influence development of the glycosidases studied in both CNS parts.


Dissociation of growth hormone and prolactin response to levodopa during pyridoxine administration. 500 mg of levodopa was administered orally to 8 normal subjects and induced an increase of growth hormone (GH) and a decrease of prolactin (PRL) secretion. The levodopa-induced GH release was inhibited by an intravenous infusion of pyridoxine; on the contrary, the PRL response to levodopa was enhanced by pyridoxine infusion. This dissociation of GH and PRL responses to levodopa during pyridoxine infusion appears to be mediated by peripheral acceleration of the conversion of levodopa to dopamine. Since dopamine does not penetrate the blood-brain barrier, the enhanced PRL decrease observed during pyridoxine infusion might be explained only on the basis of a mechanism of action exerted by dopamine on extra blood-brain barrier sites.


Isoelectric focusing of interacting systems. I. Carrier ampholyte-induced macromolecular isomerization. A phenomenological theory of isoelectric focusing is formulated for rapidly reversible, ampholyte-induced macromolecular isomerization. The calculations reveal that such interactions can give well resolved, bimodal transient and equilibrium isoelectric focusing patterns in which the two peaks correspond to different chemical equilibrium compositions and not to separated isomers. The kinetics of approach to the equilibrium pattern are characteristically biphasic: During the first phase, which is controlled by the rate of migration of the isomers in the electric field, two peaks are positioned in the region between the isoelectric points of the two isomers; one of the peaks then grows slowly at the expense of the other with a diffusion-dominated rate. The kinetics are dependent upon the initial distribution of macromolecule in the isoelectric focusing column, and in certain cases only a single peak is apparent during the first phase. These findings have practical implications for unambiguous interpretation of isoelectric focusing patterns, furnish explanations for hitherto puzzling experimental observations, and provide theoretical insights required for application of isoelectric focusing to the detection and characterization of macromolecular interactions in general.


Isoelectric focusing of interacting systems. II. pH-dependent conformational transitions. Transient and equilibrium isoelectric focusing patterns have been computed for pH-dependent conformational transitions in the limits of complete cooperativity and instantaneous chemical equilibration. Transitions induced by the binding of a relatively large number of hydrogen ions by the macromolecule give well resolved bimodal equilibrium patterns, provided that the resulting conformer has the lower isoelectric point. The corresponding transient patterns may be either bimodal or virtually unimodal for practical times of operation depending upon the point of insertion of the sample into the pH gradient and the stoichiometry of the interaction. A macromolecule undergoing sequential transitions can give multimodal isoelectric focussing patterns.


Rheology of fibrin clots. IV. Darcy constants and fiber thickness. Measurements of small oscillatory deformations of a fibrin clot by axial motion of a rod in a closed tube reveal an anomalous mechanical loss due to permeation of fluid through the clot structure. The Darcy constant for permeation can be calculated from data at the frequency where the apparent storage and loss shear moduli are equal, without the necessity of measurements at much lower frequencies as previously employed. From the Darcy constant, the average number of fibrin monomer units (v) per cross-section of a fibrous element of the clot can be calculated; it ranges from 4 to several hundred. In the range of fibrin concentration(c) from 3 to 14 milligrams, v is approximately proportional to c-2 for clots of coarse structure and to c-0.5 for clots of fine structure.


The CO and NO Bohr effect of human hemoglobin with and without inositolhexaphosphate. Using NO and CO as ligands the Bohr effect of human hemoglobin has been measured with and without inositolhexophosphate. It appears that in the absence and presence of inositolhexaphosphate hemoglobin shows a distinct ligand specificity with respect to the Bohr effect. Ligation with NO is accompanied by release of a larger number of Bohr effect. It is shown that this latter result is due to the fact that the number of protons taken up upon binding of inositolhexaphosphate to ligated hemoglobin is larger for HbNO than for HbCO. It is suggested that this additional proton uptake is partially due to a restoration of the saltbridge between His 146beta and Asp 94beta upon addition of IHP.


1H Nmr studies at 360 MHz of the methyl groups in native and chemically modified basic pancreatic trypsin inhibitor (BPTI). In the 1H NMR spectra obtained at 360 MHz after digital resolution enhancement, the multiplet resonances of the methyl groups in the basic pancreatic trypsin inhibitor (BPTI) were resolved. With suitable double irradiation techniques the individual methyl resonances were assigned to the different types of aliphatic amino acid residues. Furthermore, from pH titration and comparison of the native protein with chemically modified BPTI, the resonance lines of Ala 16 in the active site and Ala 58 at the C-terminus were identified. Potential applications of the resolved methyl resonances as natural NMR probes for studies of the molecular conformation are discussed.


Compartmentalization in proteinoid microspheres. Proteinoid microspheres with stable internal compartments and internal structure are made from acidic proteinoid and basic proteinoid with calcium. The populations of microspheres are characterized by a wide diversity of structure. A model of primitive intracellular communication is suggested by the observed movement of internal particles between compartments of a multicompartmentalized unit. Differential response to pH change and to temperature change has been demonstrated within one population and suggests one mode of adaptive selection among primordial cell populations.


Life on Mars? The Viking labeled release experiment. Viking radiorespirometry ("Labeled Release" [LR]) experiments conducted on surface material obtained at two sites on Mars have produced results which on Earth would clearly establish the presence of microbial activity in the soil. However, two factors on Mars keep the question open. First, the intense UV flux striking Mars has given rise to several theories postulating the production of highly oxidative compounds. Such compounds might be responsible for the observed results. Second, the molecular analysis experiment has not found organic matter in the Mars surface material, and therefore, does not support the presence of roganisms. However, sensitivity limitations of the organic analysis instrument could permit as many as one million terrestrial type bacteria to go undetected. Terrestrial experiments with UV irradiation of Mars Analog Soil did not produce Mars type LR results. Gamma irradiation of silica gel did produce positive results, but not mimicking those on Mars. The life question remains open.


A possible prebiotic synthesis of thymine: uracil-formaldehyde-formic acid reaction. When uracil is reacted with formaldehyde and formic acid in dilute aqueous solutions at 100-140 degrees C, 5-hydroxymethyluracil (5-HMU), methylenebiuracil (MBU) and thymine are formed. It has been shown that 5-HMU is an intermediate in the formation of MBU and thymine. In the presence of formic acid, 5-HMU gives MBU, thymine and in some cases uracil. The formation of thymine is generally favoured under acidic conditions, although small amounts of this base could also be obtained when the reactions were carried out under mildly basic conditions. A hydride ion transfer mechanism is suggested for some of these reactions. These results have relevance to the formation of thymine under prebiotic conditions.


Chemical evolution XXIX. Pyrimidines from hydrogen cyanide. Dilute (0.1 M) solutions of HCN condense to oligomers at pH 8-9. Hydrolysis of these oligomers at pH 8.5 or with 6 N HCl yields 4,5-dihydroxypyrimidine, as the most abundant pyrimidine product along with orotic acid and 5-hydroxyuracil. These results, together with the earlier data, demonstrate that the three major nitrogen-containing classes of biomolecules could have originated from HCN on the primitive earth. The observation of the formation of orotic acid and 4-aminoimidazole-5-carboxamide by the hydrolysis of the HCN oligomers suggests that once the initially formed pyrimidines and purines were consumed, those life forms persisted which evolved enzymes for conversion of these intermediates to the pyrimidines and purines present in contemporary RNA.


The mechanism of clay catalyzed polymerization of amino acid adenylates. Amino acid adenylates were adsorbed on montmorillonite when either the interspatial faces or the edges of the latter were blocked. By this method it could be observed that adsorption of the amino acid adenylates takes place mostly on the planes of the clay. However, for polymerization to take place, the edges of the clay have to be free as well and apparently only these molecules polymerize which are attached to the planes of the clay by their amino groups and to the edges of the clay by their phosphate group. Thus all the charges of the molecules which might produce their repulsion from each other would be neutralized. As a consequence of these attachments polymerization on the clay would take place on its planar sites, but only on those neighboring its edges. The question whether neutralization of charges is also the reason why biochemical substrates have to attach themselves by several points to enzymes and thus make biochemistry fit into the framework of general chemistry, is raised.


Comparison of polymerization of ancrod and thrombin fibrin monomers. The polymerization of thrombin and ancrod fibrin monomers was studied with a standardized technique that evaluated turbidity changes and protein incorporation into the clot. Ancrod fibrin monomers were found to polymerize more slowly and form less turbid clots (at identical protein concentrations). Changes in ionic strength and pH influences ancrod fibrin monomer polymerization to a greater extent than thrombin fibrin monomer polymerization. Benzyltriethylammonium chloride was shown to be a potent inhibitor of fibrin monomer polymerization, with a greater inhibitory effect on ancrod fibrin monomers than on thrombin fibrin monomers. The differences between ancrod and thrombin fibrin may play a role in the infrequent thrombotic complications reported with ancrod therapy.


Allogeneic bone marrow transplantation in conventional mice: I. Effect of antibiotic therapy on long term survival of allogeneic chimeras. In the present communication the beneficial effect of long term antimicrobial treatment with poorly absorbable antiboitics on the survival of allogeneic bone marrow chimeras was investigated. The combination of C57Bl mice as bone marrow donors and CBA/CA mice as irradiated recipients (800 rad) was used because of their strong histoincompatibility on the H-2 loci. All allografted recipients received 10 X 10(6) bone marrow cells. The majority of the recipients, which were rendered gnotobiotic by an antimicrobial treatment, achieved stable long term chimerism. In contrast, the conventional chimeras died from secondary disease within 9 weeks after transplantation. As early as 14 days after allogeneic bone marrow grafting the gnotobiotic recipients tolerated the reassociation with a conventional microflora without a change in the rate of mortality. Bone marrow cells (8 X 10(6) i.v.) and spleen cells (2 X 10(6) i.v.) collected from allogeneic chimeras failed to induce graft-versus-host-reaction (GVH) in a second lethally irradiated host. The data indicate, that the high rate of mortality in murine allogeneic bone marrow chimeras results from delayed GVH-reaction and systemic infection. The marrow graft, once established seems to exert tolerance against the allogeneic host. The pathogenesis of the systemic infection has not yet been worked out. It is assumed that it originates from bacteremia, induced by radiation dependent lesions of the epithelial integrity and defected lymphatic tissue in the gut.


Acid-base response to chronic hypocapnia in man. The acid-base values of 13 patients with stable carbon dioxide tensions under controlled ventilation have been used to define the response to chronic hypocapnia in man. These patients had a respiratory paralysis and no apparent complicating disorders. Over a range of carbon dioxide tensions from 24 to 40 millimetres of mercury, the arterial blood hydrogen ion concentration decreased linearly by 0.32 nanomole per litre per millimetre of mercury decrement in carbon dioxide tension. Of primary interest was the finding that the slope of the regression line in chronic hypocapnia is close to that already reported for chronic hypercapnia. The physiological response to chronic hypocapnia in man is defined by a band that is approximately 10 nanomoles per litre (0.09 pH unit) wide for hydrogen ion concentration and 6 millimoles per litre wide for bicarbonate concentration. These significance bands may be used to differentiate additional acid-base disorders in patients with chronic hypocapnia over a clinically useful range of carbon dioxide tensions.


Effects of aspirin-like drugs on canine gastric mucosal blood flow and acid secretion. 1. The effects of aspirin, paracetamol and benorylate were studied on gastric mucosal blood flow (MBF) and acid secretion in canine denervated gastric pouches. 2. Aspirin 20 mM in the unstimulated pouch had no effect; pentagastrin-stimulated acid output, but not MBF, was reduced. Aspirin buffered to pH 6 was ineffective. 3. Aspirin 3-50 mg/kg reaching the pentagastrin-stimulated pouch through the blood, increased acid secretion and MBF, but the MBF:secretion ratio was variably affected. 4. Paracetamol (10 or 20 mg/kg i.v., or 20 mM in the pouch) or benorylate (280 mg/kg orally) mainly had little effect. 5. Circular muscle strips from dog arteries were contracted by prostaglandins E2, F1alpha or F2alpha, and often slightly by indomethacine, but prostaglandin E1 produced variable effects. 6. These results do not favour the view that aspirin causes gastric bleeding in dogs by breakdown of blood vessels due to ischaemia following mucosal vasoconstriction.


The uptake and overflow of radiolabelled beta-adrenoceptor blocking agents by the isolated vas deferens of the rat. 1. A comparison of uptake into and overflow from the isolated vas deferens of the rat has been made between [3H]-noradrenaline ([3H]-NA), [14C]-D-sorbitol and three radio-labelled beta-adrenoceptor blocking agents, [14C]-practolol, [14C]-(+/-)-propranolol and [3H]-penbutolol. 2. The accumulation of [3H]-NA after 30 min incubation was reduced by desmethylimipramine (DMI) 1 X 10(-8)M and was also reduced in vasa from rats pretreated with 6-hydroxydopamine (6-OHDA). This was not so with [14C]-D-sorbitol. 3. 6-OHDA pretreatment of the rats reduced the uptake of [3H]-penbutolol after 30 min incubation but not that of [4C]-propranolol or [14C]-practolol. DMI 1 X 10(-8)M did not alter the tissue uptake of [14C]-propranolol, [14C]-practolol or [3H]-penbutolol. 4. Electrical stimulation of vasa preloaded with [3H]-NA caused a significantly greater increase in [3H]-NA overflow than during the resting, unstimulated periods. No such increase in overflow was observed with [14C]-sorbitol or any of the three beta-adrenoceptor blocking agents use. 5. The beta-adrenoceptor blocking agent penbutolol was shown to possess adrenergic neurone blocking activity in the isolated vas deferens of the rat. 6. It is concluded that any effect that practolol or (+/-)-propranolol have on noradrenergic neurones is brought about without the need for these drugs to gain access to the interior of the neurone.


Selective induction of tyrosine hydroxylase and dopamine beta-hydroxylase by nerve growth factor: comparison between adrenal medulla and sympathetic ganglia of adult and newborn rats. Administration of NGF to newborn and adult rats elicits a selective increase in TH and DBH both in sympathetic ganglia and adrenal medulla. This effect does not depend on intact preganglionic cholinergic fibers. The augmented enzyme activity results from enhanced enzyme synthesis since it can be abolished by cycloheximide and NGF has been shown to enhance the incorporation of [3H]leucine into DBH molecules. The responsiveness of the adrenal medulla to NGF is also supported by light and electron microscopic autoradiograms which show that intravenously injected 125I-NGF is accumulated with high selectivity in adrenal chromaffin as compared to adjacent adrenal cortical cells. In spite of the many similarities between the response of the adrenergic neurons and adrenal chromaffin cells to NGF, there are also two distinct differences. (a) In newborn rats the ratio between the TH increase effected by a single and 10 subsequent daily injections of NGF is 1:2 in the adrenal medulla and 1:7 in the superior cervical ganglia. (b) If adrenal medullae are transferred to organ culture after intravenous injection of NGF, maximal TH response is initiated 60-90 min after NGF administration. In superior cervical ganglia only a half-maximal response is initiated at that time. After a stationary phase a second increase starts after about 6 h to reach the maximum after 12 h. The biphasic time course of the initiation of TH induction by NGF in sympathetic ganglia is in agreement with the time course of 125I-NGF accumulation after intravenous injection27 reflecting the moiety of NGF reaching the cell bodies of the adrenergic neurons directly by the blood stream (initial accumulation) and by retrograde axonal transport (second phase).


Biochemical differentiation of aggregating cell cultures of different fetal rat brain regions. Rotation-mediated aggregating cell cultures of mechanically dissociated fetal rat brains divided into three (telencephalon, mesencephalon-diencephalon and rhombencephalon), or two (telencephalon and mesencephalon-diencephalon plus rhombencephalon) parts were examined for their biochemical differentiation by measuring the specific activities of choline acetyltransferase, acetylcholinesterase, glutamic acid decarboxylase, tyrosine 3-monooxygenase, aromatic L-amino acid decarboxylase, catechol methyltransferase and monoamine oxidase. The results showed that such parts yielded cultures that were relatively enriched for acetylcholine-synthesizing (telencephalon) or catecholamine-synthesizing (mesencephalon-diencephalon and mesencephalon-diencephalon plus rhombencephalon) enzymes. For cultures which were derived from two brain divisions, the sum of the total activity for each enzyme in the parts after 30 days equalled that in whole brain cultures derived from the same group of embryos, suggesting that development of these enzymes was unaffected by division of the brain in two. In experiments to determine the effects of culture conditions on this development, chronic administration of certain drugs was found to selectively influence the specific activity of certain neurotransmitter metabolizing enzymes. Thus, in cultures of whole brain, ascorbic acid (0.2 mM) decreased tyrosine 3-monooxygenase and aromatic L-amino acid decarboxylase while other enzymes were slightly increased; and in cultures of telencephalon and mesencephalon-diencephalon plus rhombencephalon, N6, O2'-dibutyryladenosine 3',5'-cyclic phosphate (0.2 mM) decreased the specific activities of choline acetyltransferase acetylcholinesterase, glutamic acid decarboxylase and monoamine oxidase. These results demonstrate the feasibility of growing these cultures for pharmacological studies in developmental neurobiology.


The importance of Lactobacilli in maintaining normal microbial balance in the crop. 1. The effect of lactobacilli on Escherichia coli has been examined in vitro and in chicken crop in vivo. 2. Inhibition of E. coli was dependent on the presence of sufficient numbers of lactobacilli. 3. In a standard test some lactobacilli were bacteriostatic and one was bactericidal. The bacteriostasis was due to the low pH produced by these strains but bactericidal activity could not be accounted for by pH alone. 4. In gnotobiotic animals the bactericidal strain was no more inhibitory for E. coli than was a bacteriostatic strain.