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Biomedical subjects

M Berger

Publications and source records attributed to M Berger.

At least 649 records · Page 36Linked to original sources
PubMed1987

13-Hydroxyoctadeca-9,11-dienoic acid (13-HODE) inhibits thromboxane A2 synthesis, and stimulates 12-HETE production in human platelets.

The effect of 13-hydroxyoctadeca-9,11-dienoic acid (13-HODE), a major lipoxygenase product of endothelial cell linoleic acid metabolism on thrombin-induced platelet thromboxane B2 (TxB2), and 12-hydroxyeico-satetraenoic acid (12-HETE) production was evaluated. 13-HODE inhibited thrombin-induced TxB2 production in human platelets in a concentration-dependent manner. At concentrations of 10 and 30 microM, 13-HODE inhibited TxB2 production by 28 +/- 8% (1SE, n = 5; P less than 0.05) and 48 +/- 6% (P less than 0.01) respectively. 13-HODE (30 microM) also inhibited the production of platelet hydroxyheptadecatrienoic acid (38 +/- 5%, P less than 0.01). A concomitant stimulation of 12-HETE production by 13-HODE was observed (25 +/- 5% and 49 +/- 22% over control values at 10 and 30 microM respectively, P less than 0.01). Our results demonstrate a differential effect of 13-HODE on thrombin stimulated platelet cyclooxygenase and lipoxygenase metabolites.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1987

13-Hydroxyoctadecadienoic acid (13-HODE) stimulates prostacyclin production by endothelial cells.

The effect of 13-hydroxyoctadecadienoic acid (13-HODE), an endogenous lipoxygenase metabolite of linoleic acid, on prostacyclin production by fetal bovine aortic endothelial cells was evaluated. Time-dependent release of radioimmunoassayable 6KPGF1 alpha in the presence of 13-HODE (10 uM) was stimulated by 39%, 27%, and 34% at 10, 30 and 120 min respectively. 13-HODE (10 uM) had no effect on the conversion of exogenous [14C] arachidonic acid (AA) to prostacyclin. When the effect on AA release was evaluated in [14C] AA prelabeled cells, 13-HODE (10nM) stimulated the release of AA from membrane phospholipids. Analysis of cellular phospholipids revealed a significant decrease in phosphatidylethanolamine. Our results demonstrate that 13-HODE stimulates prostacyclin production by enhancing AA release from phospholipids.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

[Infusion therapy of acute vertebragenic pain syndrome].

In the course of a double blind study 67 patients with acute vertebragenic pain syndromes have been treated with 3 infusion solutions, which only differed from each other by the analgetic component. Nefopam as an analgeticum showed a clearly prolonged effect and a quicker analgetic effect. As far as pains which occurred during a resting period and pains which occurred during a movement were concerned no differences in the effect were observed. Patients treated with Nefo-Dolpasse showed a smaller rate of side effects than those treated with comparable solutions.

Aminopyrine↗
PubMed1987

Studies on the mechanism of T cell inhibition by the Pseudomonas aeruginosa phenazine pigment pyocyanine.

Pseudomonas aeruginosa and its products have been shown to inhibit mitogen-induced human lymphocyte blastogenesis as measured by [3H]TdR uptake. The phenazine pigment pyocyanine has been identified as one of the inhibitors present in cellfree culture supernatants. To determine the mechanism of the inhibitory action of pyocyanine, we studied its effect on the early stages of T cell activation. Pyocyanine inhibited lymphocyte stimulation induced by specific antigens, the lectin concanavalin A and the calcium ionophore, ionomycin, suggesting that its inhibitory effect is not dependent on interference with the T cell antigen receptor complex itself. Using quin-2, we showed that pyocyanine did not interfere with the mitogen-induced increase in cytosolic-free Ca2+. We also showed that pyocyanine did not interfere with the function of calmodulin stimulated Ca2+-Mg2+ ATPase activity, indicating that the mechanism of action of pyocyanine differs from that of the structurally related phenothiazine compounds. Analysis of IL 2 production and IL 2 receptor expression clearly showed that pyocyanine inhibits the production of this essential lymphokine as well as the expression of IL 2 receptors on the T cell membrane. This inhibition is dose dependent and not due to cellular toxicity. There was parallel inhibition of growth in cell volume as well as [3H]TdR uptake. Thus, our results demonstrate that pyocyanine inhibits T cell proliferation by decreasing the production of the critical lymphokine IL 2 and by decreasing the expression of the IL 2 receptor. Local suppression of lymphocyte stimulation by phenazine pigments such as pyocyanine may interfere with cellular immune responses that may be necessary for eradication of chronic infection with P. aeruginosa.

Adult↗
PubMed1987

Cell-free fatty acylation of microsomal integrated and detergent-solubilized glycoprotein of vesicular stomatitis virus.

An enzymatic activity associated with intracellular membrane fractions of Merwin plasma cell tumor II, baby hamster kidney, and chicken embryo fibroblast cells and bovine kidney has been characterized which covalently links fatty acids onto the G protein of vesicular stomatitis virus. Exogenous G protein extracted from native vesicular stomatitis virus particles can be acylated in vitro only after it has been previously deacylated. The fatty acids transferred in vitro are sensitive to treatment with hydroxylamine, indicating an ester linkage. Cell-free acyl transfer was also observed with endogenous G protein present in membrane fractions prepared from vesicular stomatitis virus-infected cells. In this case, the fatty acids become linked to a G protein species (G1) which is not terminally glycosylated and therefore has not entered the trans-Golgi compartment. The same G protein species also becomes acylated in infected cells during short pulses with radioactive palmitic acid. Acylation of the G protein in vitro with free palmitic or myristic acid is energy-dependent, and the addition of ATP is specifically required. Other nucleoside triphosphates cannot substitute for ATP in the activation of free acyl chains. Alternatively, activated fatty acids linked in a high energy thioester bond to coenzyme A, e.g. [14C] palmitoyl-CoA, are suitable lipid donors in the in vitro acylation reactions. Palmitic acid transfer onto G protein shows the typical characteristics of an enzyme-catalyzed reaction.

Acyltransferases↗
PubMed1987

Detection and enzymatic deglycosylation of a glycosylated variant of prolactin in human plasma.

Immunoperoxidase electrophoresis was applied to the plasma of a patient showing a high level of prolactin (PRL) secreted by a pituitary adenoma. Two PRL monomers were detected with an anti-hPRL antiserum: a major 22 kDa form and a minor 25 kDa form. Concanavalin A-Sepharose 4B chromatography revealed that the 25 kDa form was a glycosylated variant of PRL. Incubation of this variant with endoglycosidase F led to its transformation into the 22 kDa form.

Adenoma↗
PubMed1987

Severe thrombocytopenia in iron deficiency anemia.

Mild-to-moderate thrombocytopenia has been reported as an occasional finding in patients with iron deficiency. The present case describes a multiparous woman who presented with increased menorrhagia, severe anemia (3.0 g/dl) and thrombocytopenia (9,000 platelets/mm3). Her bone marrow examination showed iron deficiency, megakaryocytopenia, and erythroid hypoplasia but no other evidence of a primary marrow disorder. Her symptoms, the thrombocytopenia and the megakaryocytopenia, resolved with iron replacement. This case demonstrates the profound degree to which thrombopoiesis can be affected in iron deficiency.

Adult↗
PubMed1987

Human insulin: much ado about hypoglycaemia (un)awareness.

The biological effects, hypoglycaemic symptoms, endocrine counterregulatory responses and glucose recovery following the injection of purified porcine and human insulin preparations were compared in a number of controlled clinical investigations and prospective clinical trials. In these studies involving healthy volunteers, Type 1 (insulin-dependent) diabetic patients on continuous subcutaneous insulin infusion or intensified conventional insulin therapy and insulin treated Type 2 (non-insulin-dependent) diabetic patients, no differences with regard to biological effects, counterregulatory responses, hypoglycaemic awareness or the long-term incidence of severe hypoglycaemia between porcine and human insulin preparations were identified. These data fail to confirm any specific risk of severe hypoglycaemia attributable to the use of human insulin preparations in the treatment of patients with diabetes mellitus.

Adult↗
PubMed1987

Cystic fibrosis--a single locus disease? Results of a population genetics study.

In a population genetics study of cystic fibrosis (CF), we investigated the state of health of 1276 first cousins of CF index patients. Six hundred seventy-five married aunts and uncles (siblings of CF index patients' mothers and fathers) who had at least one child were interviewed. In only 1 of these 675 families, three children of a total of eight had died of CF. If CF occurs more frequently than in 1 in 3000 newborn babies in our population, our investigation supports the hypothesis that CF is caused by mutations at more than one locus. We also determined that the evidence furnished by such a study of other, more uncommon autosomal recessive disorders is limited.

Cystic Fibrosis↗
PubMed1987

Evaluation of an intensified insulin treatment and teaching programme as routine management of type 1 (insulin-dependent) diabetes. The Bucharest-Düsseldorf Study.

It has been questioned whether aiming at near-normoglycaemia by intensified insulin treatment regimens is feasible and safe for the majority of patients with insulin-dependent diabetes. In this study, intensified insulin injection therapy (including blood glucose self-monitoring and multiple insulin injections) based upon a 5-day inpatient group teaching programme was evaluated in Type 1 (insulin-dependent) diabetes mellitus in the centralised health care system of Bucharest. One hundred patients (group A, initial HbA1 12.5%) were followed for 1 year on their standard therapy (individual teaching, no metabolic self-monitoring), and thereafter for 1 year on intensified therapy. Another 100 patients (group B, HbA1 12.3%) were followed for 2 years on intensified therapy. A third 100 patients (group C, HbA1 11.7%) were assigned to a basic 4-day inpatient group teaching programme with conventional insulin therapy (including self-monitoring of glucosuria and acetonuria) and followed for 1 year. Mean HbA1 remained unchanged after standard treatment (group A: 12.8% at 12 months), but decreased during intensified therapy (group A: 10.1% at 24 months; group B: 9.3% at 12 months, 9.5% at 24 months; p less than 0.0001). In group C, no change was found compared to standard treatment (i.e. group A at 12 months). Incidence rates of ketoacidosis were 0.16 episodes per patient per year during standard treatment, 0.01 during intensified treatment (p less than 0.01) and 0.04 in group C (p less than 0.025). Hospitalisation rates were reduced by 60% during intensified therapy and by 40% in group C. Frequency of severe hypoglycaemia was not significantly different between the three treatment regimens. Thus, under the condition that insulin treatment is based upon a structured and comprehensive training of the patient, intensified insulin injection therapy performed as routine treatment of Type 1 diabetes significantly lowers HbA1 levels without increasing the risk of severe hypoglycaemia.

Adolescent↗
PubMed1987

Evaluation of a minimal-therapist-contact thermal biofeedback treatment program for essential hypertension.

We compared a clinic-based regimen of 16 individual sessions (2 per week) of thermal biofeedback with a largely home-based regimen of 5 sessions (spread over 8 weeks) for the treatment of essential hypertension in patients who required at least two drugs to maintain control of blood pressure (BP). On the basis of the clinical end point of being successfully withdrawn from the second stage medication while BP remained under control, the clinic-based regimen (5 of 9) was superior (chi less than (1) = 4.0, p less than .05) to the home-based regimen (1 of 9). Internal analyses point to more frequently obtaining a hand temperature of at least 95 degrees F by the office-based patients as possibly the reason for the difference.

Adult↗
PubMed1987

Distribution and metabolism of hexadecylphosphocholine in mice.

Distribution and metabolic fate of radiolabeled hexadecylphosphocholine (He-PC) has been studied in mice. It is demonstrated that He-PC is well-absorbed from the intestinal tract, intravenous (IV) and oral administration lead to similar distributions throughout the body, the highest accumulation of radioactivity occurs in liver, lung and kidney, and the metabolic products are radioactive choline, phosphocholine and 1,2-diacylphosphatidylcholine. The occurrence of these metabolites indicates that phospholipases C and D may be involved in He-PC breakdown.

Administration, Oral↗
PubMed1987

Interindividual differences in the susceptibility of the cortisol system: an important factor for the degree of hypercortisolism in stress situations?

Whereas in psychophysiological research, the specificity of the individual responses has been assumed to be an important trait variable influencing the investigated parameters in stress experiments or in psychopathological states, in psychoneuroendocrinology, the individual differences in the susceptibility of the investigated neuroendocrine axes have been widely neglected. The present study on the cortisol response of 12 healthy young men to 5 different stress tests is considered to be an initial orientation step into this field. All five stress tests (quiz, arithmetic tasks, stress film, cold pressor test, and physical exercise test) could be proven to be effective stimuli regarding the cortisol system. There was, however, a broad spectrum of cortisol responses among the 12 subjects, with a continuum between complete reactors and nonreactors. This did not correlate with the subjective judgment of stress at all. Although the data showed a tendency toward an augmented dispersion of the response frequencies in comparison with random variation, the limited sample size of subjects and stress tests did not allow a statistically significant proof of a stimulus-independent, individual response specificity. Further experimental clarification seems to be necessary to avoid misinterpretations of neuroendocrine data in psychiatric disorders due to neglect of this variable.

Adult↗
PubMed1987

The influence of the muscarinic agonist RS 86 on the cortisol system.

To test the assumption that activation of the hypothalamic-pituitary-adrenocortical (HPA) axis is mediated by cholinergic neurons, the cortisol response to the administration of the muscarinic agonist RS 86 was investigated in 12 healthy volunteers. In addition, prolactin and growth hormone secretion patterns were assessed. No significant increase in plasma cortisol or growth hormone was observed after the administration of 1.5 and 3.0 mg RS 86, respectively. However, there was a slight increase in prolactin serum concentration after 3.0 mg RS 86. As RS 86, when used in the same dose range, causes a shortening of rapid eye movement (REM) latency and displays antimanic properties, it is unlikely that a reduced dosage of RS 86 in itself accounts for the lack of stimulation of the HPA axis. If one assumes that in humans the stimulation of the HPA axis is under cholinergic control, then the failure of RS 86 to increase cortisol might be attributable to the fact that different subtypes of muscarinic neurons, for which RS 86 is not a full agonist, are involved, or else nicotinic neurons are implicated in the activation of the HPA axis.

Adolescent↗