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Biomedical subjects

M Braun

Publications and source records attributed to M Braun.

At least 307 records · Page 17Linked to original sources
PubMed1984

Recognition by a murine monoclonal antibody of a unique epitope specific for the human alloantigen HLA-B8.

A cytotoxic murine monoclonal antibody recognizing a specific HLA alloantigen was produced from the spleen cells of a BALB/c immunized with partially purified class I glycoproteins from an HLA-A1,B8 homozygous B-lymphoblastoid cell line. The antibody, designated P8.1, was tested against cells from 521 unrelated donors. It reacted with each of the 83 donors known to be HLA-B8 positive and with no HLA-B8 negative donors (sensitivity, 100%; specificity, 100%). Immunoprecipitation with antibody P8.1 and polyacrylamide gel electrophoresis confirmed that the antigen recognized was a class I structure. Although most murine monoclonal anti-HLA antibodies previously described have recognized "public" or supertypic specificities, the identification of a monoclonal antibody specific for a "private" HLA alloantigen indicates first that the BALB/c mouse has the appropriate immune response repertoire for recognizing certain HLA allospecificities and second that HLA-B8 can be defined by a single unique epitope.

Animals↗
PubMed1984

Complement activation in patients at risk of developing the adult respiratory distress syndrome.

In this prospective study of 50 patients, 36 of whom developed the adult respiratory distress syndrome (ARDS), early and intense complement activation was demonstrated. These patients were at risk of the ARDS because of multiple injuries, major abdominal surgery, acute pancreatitis, severe burns, or disseminated intravascular coagulation. Abnormal C3 consumption (as measured by the C3d/C3 ratio) and elevated plasma C5a-like activity (as measured by a leukocyte aggregation assay) were associated with, respectively, 84 and 86% of cases of ARDS. Both tests were more sensitive indicators of complement consumption than were assays of total hemolytic complement activity (CH50) or total C3. The C3d/C3 ratio showed a close, inverse correlation with CH50 in 47 healthy subjects, and was increased in 12 control patients after minor surgery. The C5a-like activity was found only in patients at risk of ARDS; it was highly associated with clinical conditions that predispose to the ARDS, but it cannot be considered as a real predictor of ARDS occurrence in these patients. Sequential samples from both sides of the pulmonary circulation showed initial pulmonary clearance followed by the release of C5a-like activity. No simultaneous changes in C3 levels were found, suggesting the possible presence of modulating factors. These observations suggest that other factors (e.g., hypoxia and metabolic cascades) may influence the development of ARDS.

Complement Activation↗
PubMed1984

[Effect of an acidic sulfated polysaccharide on whole blood coagulability. In vivo study in rats].

Armatan, an acid sulphated polysaccharide isolated from a red marine seaweed Asparagopsis armata (Harv.), increases the coagulation time of the rat plasma in vivo assays. This property presents, with administration, time and dose, some variations. Among the three ways studied, subcutaneous injection gives more interesting results than the others. At high concentrations (10, 20 and 50 mg/kg), intravenous administration induces plasma and organic (liver-spleen) diseases.

Animals↗
PubMed1984

Pharmacologic effects on mouse isolated atria of immunoglobulins directed against class I histocompatibility antigens.

Sera from alloimmunized mice exert potent inotropic and chronotropic effects on mouse isolated atria. In this report, we present data showing that both total immunoglobulins and purified IgG from alloimmunized mice were able to exert per se these effects. The pharmacologic effects of IgG were parallel to its cytotoxic titer but not to its immunofluorescence titer. The specificity of the inotropic and chronotropic effects was studied by using several interstrain immunizations and target atria. It was observed that only the sera from mice immunized with H-2-disparate cells were able to exert pharmacologic effects on atria; these effects were evident not only on atria from the immunizing strain, but also on atria from other strains having identical H-2 but different backgrounds. Neither normal sera nor sera from animals immunized against non-H-2 differences were active. The effect of sera, total immunoglobulins, and purified IgG were blocked by propranolol, suggesting the involvement of beta-adrenoreceptor in the reaction.

Animals↗
PubMed1984

Malignant melanoma and levodopa.

A patient with Parkinson's disease developed a malignant melanoma within a congenital nevus after starting levodopa therapy. Levodopa has a central role in the metabolism of the melanocyte but data do not permit the conclusion that it promotes the development of malignant melanoma. However, patients receiving levodopa should be monitored for skin changes suggestive of melanoma.

Humans↗
PubMed1983

[Multidimensional evaluation of clinical geriatric psychiatry exemplified by the therapy-modifying effect of ecological variables].

The study describes the multidimensional approach of an evaluation project and analyses the ecological milieu as perceived by the personal of one closed, open and semi-stationary ward respectively by way of a ward atmosphere inventory (Stationsbeurteilungsbogen - SBB - by Engel et al.). The results point to very differing ecological milieus on closed and open wards. Open wards of the fully stationary and the semi-stationary type, however, display only isolated yet prominent differences. The discussion of these results takes into consideration the diagnostically different groups of patients on wards of differing degree of institutionalization, accounts for the burdensome task of running a closed ward, and points to prerequisites of a more adequate care for demented patients.

Aged↗
PubMed1983

Cellular immunity in Chagas' disease patients. Lymphoproliferative response to subcellular fractions of Trypanosoma cruzi.

The ability of peripheral mononuclear cells from Chagas' disease patients (CDP) to generate specific proliferative responses in vitro to whole homogenate (WH) and subcellular fractions of T. cruzi was investigated. Flagellar (F), microsomal (Mc) and cell sap (CS) fractions were isolated from a WH obtained by disruption by pressure-depressure. Parasite-free human peripheral mononuclear cells were isolated by centrifugation of leukocyte-rich plasma over discontinuous gradients of Ficoll-Hypaque and cultured for 6 days in the presence of the different fractions of T. cruzi. Eighty-six percent (54/63) of the CDP showed good capacity to respond to at least one of the fractions assayed while only 18% (4/22) of the controls reacted. The Mc fraction showed the best specificity as well as the maximal stimulating effect in CDP (37/55 vs 0/18 in controls) while WH (62% vs 10%), F (54% vs 16%) and CS (52% vs 6%) showed a lesser antigenic capacity. These results suggest that recognition mechanisms and proliferative responses are functional in CDP. No correlation was found between the stimulating capacity of fractions in vitro and their immunogenic capacity previously observed in vivo.

Cell Count↗
PubMed1983

[Characteristics of the action of an acidic sulfated polysaccharide on global blood coagulation in vitro. Preliminary study in various species of mammals and in man].

An acid sulphated polysaccharide, isolated from a red marine seaweed, Asparagopsis armata ( Harv .), increases the coagulation time of the plasma in vitro studies. This property, compared with the anticoagulant activity of pentosan polysulphate and heparin, pr esents , with concentration and temperature, some variations in man and other mammals . The rat and human plasma seem to behave in the same way with this substance.

Animals↗
PubMed1982

Unusual distribution of Ia-like antigens on canine lymphocytes.

The murine monoclonal antibody 7.2, specific for a framework determinant of human Ia antigens, cross-reacts with canine cell membranes recognizing a bimolecular complex (29,000 and 34,000 daltons) similar to that described in man. We investigated the distribution of these Ia-like antigens on mononuclear cells in peripheral blood, thoracic-duct lymph, marrow, alveolar lavage fluids, lymph nodes, and thymuses from normal dogs. By complement-mediated cytotoxicity and indirect immunofluorescence, virtually all lymphocytes expressing surface immunoglobulin (B lymphocytes), monocytes/macrophages, dendritic cells, and many thymus-epithelial cells were Ia-positive. Furthermore, most non-B-lymphocytes in peripheral blood, thoracic-duct lymph, and lymph nodes expressed Ia antigens. Alveolar (T) lymphocytes and most thymocytes were Ia-negative. Generally, fluorescence intensity was higher on monocytes/macrophages and B lymphocytes than on non-B-lymphocytes. In mixed leukocyte cultures and concanavalin A-induced blastogenesis assays, treatment of responder cells with antibody 7.2 and complement abolished proliferation. Proliferative responses could not be restored by adding untreated accessory cells, indicating that cytolytic treatment had eliminated responder T-lymphocytes. However, addition of antibody alone to cultures had no significant effect. These studies indicate that most mature canine T-lymphocytes express Ia-like antigens. Whether this is an intrinsic property of canine cells or possibly related to continuous in vivo stimulation remains to be determined.

Animals↗
PubMed1982

Density gradient purification of human lymphocytes from contaminating trypomastigotes of Trypanosoma cruzi.

Mixtures of normal human lymphocytes and T. cruzi trypomastigotes obtained from infected mice were centrifuged over Ficoll-Hypaque (FH) continuous and discontinuous gradients. Trypomastigotes were confined to the range 1.051-1.057 g/ml while lymphocytes ranged between 1.046 and 1.080 g/ml. Over 80% of the lymphocytes were found at 1.060 g/ml or higher densities. A discontinuous gradient of FH with 2 layers of 1.060 and 1.077 g/ml of density respectively was selected to obtain trypomastigotes-free white blood cells from blood samples. The functional capacity of lymphocytes recovered from the lower interface, where no parasites were found, was assessed. The response to phytohaemagglutinin of these high density lymphocytes was as good as to total lymphocytes, suggesting that low density lymphocytes are not necessary for proliferative responses. It is postulated that high density lymphoid populations, free from T. cruzi forms, may be used to study the presence of T cell-mediated immune response in Chagas' disease patients.

Animals↗
PubMed1982

Comparative evaluation of several rare-earth film-screen systems.

Comparisons of image quality were made for several rare-earth film-screen combinations under conditions similar to those used in chest radiography. The characteristic curve, modulation transfer function, and Wiener spectrum were measured. Observer response studies were carried out to compare the limits of perceived resolution. Signal-to-noise considerations based on the measured characteristics favor a fast film-show screen pair over a slow film-fast screen pair, consistent with the observer study results. The interrelationship of the physical parameters in determining image quality and the limitations of the method are discussed.

Humans↗
PubMed1982

[On the importance of new test of HDL-cholesterol in lipoid diagnostics with geriatric patients (author's transl)].

1. By introducing a HDL-cholesteroltest in the multiple screening we have the chance to valuate the diagnostical validity of the test value of triglycerides, total cholesterol and HDL-Cholesterol and of the calculated value of LDL-cholesterol and ratio HDL/LDL-cholesterol. 2. We studied the incidence of lipoid findings of 210 patients by graphical statistics. 3. The test values of triglycerides, total cholesterol and HDL-cholesterol manifest a mixed collection with a graph having different maximums whereby statistically a "normal" population can be differentiated from a "pathological" population. 4. The calculated value LDL-cholesterol is normal distributed, the ratio HDL/LDL-cholesterol is logarithmic normal distributed. The causes therefore are statistic effects.

Aged↗
PubMed1981

[Closed drainage of the urinary bladder. Method and results in the rehabilitation of the infected, contracted bladder in stroke patients].

Catheterism of the urinary bladder in the primary therapy after stroke is often the initial condition for the development of an infected contracted bladder. The patient is bearing his catheter for life because there is a disproportion of production of urine (greater than 1500 ml) and capacity of the urinary bladder (less than 100 ml). Infection and restriction of movement hinder his discharge from hospital. There are five conditions for a treatment of contracted bladder using a closed drainage of the bladder: 1. functional training of the capacity, 2. reduction of reinfection and antibiotic therapy, 3. training of sensibility, 4. use of day-and-night-rhythm, 5. gymnastics for pelvic floor. The therapeutic result--200 ml capacity of urinary bladder, control of infection and voluntary miction--can be reached after 4-6 weeks, if patient, nursing staff and physician are cooperative. The experiences of 8 cases demonstrate that a contracted bladder needs not be a final state, but can be rehabilitated.

Aged↗
PubMed1981

Clostridium aceticum (Wieringa), a microorganism producing acetic acid from molecular hydrogen and carbon dioxide.

Spores of Clostridium aceticum (Wieringa) from 1947 have been revived, and a study for a redescription of this microorganism has been carried out. C. aceticum was Gram negative. The cells were rodshaped and peritrichously flagellated. Round spores were formed in terminal position. The DNA contained 33 mol % guanine plus cytosine. The organism was obligately anaerobic and grew either chemolithotrophically with H2 + CO2 or chemoorganotrophically with compounds such as fructose, L-glutamate, L-malate or pyruvate. H2 and CO2 were converted to acetic acid according to the following equation: 2CO2 + 4H2 leads to CH3COOH + 2H2O The optimal temperature for growth was 30 degrees C. The optimal pH for chemolithotrophic growth was 8.3. The doubling times for chemolithotrophic and chemoorganotrophic growth were 25 and 8 h, respectively.

Acetates↗