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Biomedical subjects

R Zimmermann

Publications and source records attributed to R Zimmermann.

At least 343 records · Page 19Linked to original sources
PubMed1992

Autoantibodies in HIV-infected hemophilia patients against different epitopes on CD4+ lymphocytes and recombinant CD4.

We studied 684 sera obtained from 20 hemophilia patients with AIDS/AIDS-related complex (ARC), 89 asymptomatic HIV+, 76 HIV- hemophilia patients and 151 healthy controls for antibodies against recombinant CD4 (rCD4). Twenty-two percent of AIDS/ARC patients, 10% of asymptomatic HIV+ patients, 17% of HIV-patients, and 1% of healthy controls had anti-rCD4 antibodies. Purified anti-rCD4 antibodies did not react with human CD4+ lymphocytes. This may explain why formation of anti-rCD4 antibodies correlated neither with the occurrence of autoantibodies against CD4+ lymphocytes nor with a decrease in CD4+ cell counts. Antibodies that were eluted from CD4+ lymphocytes after sequential adsorption and elution with separated CD8+ and CD4+ cells reacted with CD4+ lymphocytes of only some healthy individuals, suggesting diversity of CD4 expression.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Anti-IgG autoantibodies in HIV-infected hemophilia patients.

Sera of 76 HIV-negative hemophilia patients, 103 HIV-positive (HIV+) hemophilia patients free of AIDS or AIDS related complex (ARC), and 32 HIV+ hemophilia patients with AIDS/ARC were tested for four different anti-IgG activities. IgG-anti-F(ab')2 gamma, IgM-anti-F(ab')2 gamma, and IgG-anti-Fc gamma serum activities were significantly associated with the clinical stage of HIV infection, whereas IgM-anti-Fc gamma was not. IgG-anti-F(ab')2 gamma activity was found to be caused by cross-reaction of anti-HIV antibody with an epitope within the constant CH1 domain of human IgG. HIV+ hemophilia patients with severe thrombocytopenia (less than 50,000/microliters platelet counts) had significantly higher IgM-anti-IgG activity than patients with greater than 50,000/microliters platelets. Because anti-IgG antibodies possess immunoregulatory properties, our results may serve as a possible explanation for the frequent B cell disorders encountered in HIV-infected patients.

AIDS-Related Complex↗
PubMed1992

Bone marrow purging prior to autologous transplantation.

Our data suggest that ex vivo bone marrow purging using monoclonal antibodies (MoAbs) and sheep-anti-mouse immunobeads (SAM beads) prior to autologous bone marrow transplantation (ABMT) allows satisfactory tumor cell reduction without critical stem cell losses. Nevertheless, there is only a reduction but no elimination of tumor cells. The consequences will have to be clinically discussed.

Antibodies, Monoclonal↗
PubMed1992

Effect of gallopamil on neutrophil function: experimental and clinical studies.

The purpose of the study was to investigate whether gallopamil interferes with neutrophil activation. In vitro, gallopamil caused a dose-dependent reduction in phorbol myristate acetate-stimulated superoxide anion production by neutrophils as measured by the superoxide dismutase inhibited reduction of cytochrome C [concentration of 50% inhibition (IC50) = 9.5 x 10(-6) mol/L]. Furthermore, gallopamil reduced the platelet-activating factor-induced loss of neutrophil deformation, which was assessed by filtrometry (IC50 = 4.3 x 10(-6) mol/L). The effect of gallopamil was assessed in 24 patients during elective balloon angioplasty. Gallopamil (0.4 mg) or placebo (double-blind conditions) was administered by intracoronary application during the 10-min interval between the first two balloon inflations. In the placebo group, blood samples obtained simultaneously from the coronary sinus and from the femoral artery revealed an increase in the proportion of activated neutrophils in the coronary sinus blood after the second balloon inflation [nitro blue tetrazolium (NBT) score, NBT test: 15 +/- 9% relative coronary sinus and arterial blood difference, p < 0.05]; these changes in NBT score were similar to those after the first balloon inflation. In the gallopamil-treated group, however, significant arterial and coronary sinus blood differences in NBT scores were not found after the second balloon inflation. Gallopamil may, thus, attenuate the local neutrophil activation during balloon angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1992

Intracoronary gallopamil during percutaneous transluminal coronary angioplasty.

The present study was designed to investigate the effect of the calcium-channel antagonist gallopamil on myocardial ischemia during percutaneous transluminal coronary angioplasty (PTCA). Twenty-four adult patients with coronary artery disease and significant proximal stenosis of the left anterior descending coronary artery (LAD) were randomly assigned to receive gallopamil or placebo under double-blind conditions. Patients with recent myocardial infarction, apparent collateralization of the LAD, myocardial failure, sinoatrial or atrioventricular block, severe hepatic disease, or renal failure were excluded from the study. PTCA was performed with use of at least two balloon inflations, each of 2 min in duration. Gallopamil (0.4 mg) or placebo (0.9% sodium chloride) was administered during the 10-min interval between the two inflations. For determination of myocardial lactate and hypoxanthine release, blood samples were taken simultaneously from the great cardiac vein and the femoral artery before and immediately after each inflation. Electrocardiogram changes were analyzed by measuring ST-segment deviations (80 ms after the J point) and maximal T-wave deviations of the leads I, II, III, and V2, V4, and V6. The most sensitive leads for identification of myocardial ischemia in the LAD area were V2 and V4. If compared to the first balloon inflation, the degree of ST-segment/T-wave changes induced by the second inflation was significantly reduced only in the presence of gallopamil. Furthermore, if compared to placebo, ischemia-induced lactate and hypoxanthine release was decreased in the presence of gallopamil. These results suggest that intracoronary application of gallopamil attenuates myocardial ischemia during PTCA.

Adult↗
PubMed1992

[Autologous blood donation and erythropoiesis].

Autologous blood donation before elective surgery has been widely endorsed as good transfusion practice. Although only 6% of patients undergoing elective orthopedic surgery are unable to donate 3 autologous units, 40% cannot donate 4 units because they become anemic. According to the results of our study this must be due to different problems of bone marrow dynamics, which cannot be overcome by unselected use of human recombinant erythropoietin.

Adult↗
PubMed1992

[Hemoglobin follow-up of orthopedic autologous blood transfusion patients].

Patients undergoing autologous donation prior to elective orthopedic surgery show better Hb values during the perioperative period compared to those without autologous donation, all patients in both groups receiving no homologous transfusion. The widely assumed improvement of Hb regeneration during the postoperative period according to an erythropoiesis stimulated by preoperative autologous donation is not supported by our data.

Adult↗
PubMed1992

[Acquired autoimmune hemolytic anemia after liver transplantation by "auto"-anti-A and "auto"-anti-P1].

A 47-year-old man (group A) received a cadaver liver from a group 0 donor. On day 8 after the transplant the recipient developed severe immune hemolysis and showed a positive direct antiglobulin test due to two antibodies (anti-A and anti-P1) of transplant donor origin. The possible mechanisms involved in "autoantibody" formation in the recipient are discussed.

ABO Blood-Group System↗
PubMed1992

[Examination of a Berlin blood donation branch for antibodies to hepatitis C virus with the anti-HCV test and for circulating HCV-RNA using polymerase chain reaction].

Hepatitis C virus (HCV) is responsible for the majority of cases of transfusion-related hepatitis. We performed a first-generation anti-HCV EIA in 665 repeat and 168 first-time blood donors from Berlin. 4.7 and 4.2%, respectively, showed at least one indeterminate or positive result. We further looked for HCV genome in the plasma of 20 donors with reactive anti-HCV-EIA doing a polymerase chain reaction (nested PCR). The control group consisted of 20 patients with chronic hepatitis C. The PCR was negative in all examined blood donors, but was positive in 17 of 20 controls. These findings raise the question, if a positive anti-HCV test correlates with infectiosity.

Berlin↗
PubMed1992

[Anti-M after transfusion as an indication of a genetic variant of the MN locus].

We report a case of an anti-M antibody (titer 128) and MN red blood cells (RBC) in a 76-year-old female German patient. In our case, however, RBC showed weak reactions to human anti-M compared with strong reactions using rabbit anti-M. Papain treatment destroyed the RBC reactivity to human anti-M whereas the strong reactivity to rabbit anti-M was unchanged. This pattern was also demonstrable in the patient's son and grandson. Our results indicate the existence of a rare allele at the MN locus in this family.

Aged↗
PubMed1992

[Follow-up of blood donors with indeterminate reaction to anti-HIV 1/2 EIA or isolated detection of antibodies to HIV-1 core antigens (anti-p24)].

Over a period of 20 months we identified 10 voluntary blood donors with indeterminate reactions in anti-HIV 1/2 EIA tests. Western blot (WB) patterns of 6 of these 10 donors showed isolated core antibodies (anti-p24), in 4 cases WB patterns were negative. After a median follow-up period of 58 weeks (range 12-93) we have not seen a case of typical seroconversion.

AIDS Serodiagnosis↗
PubMed1992

[Erythropoiesis and iron metabolism in autologous blood donation].

Autologous blood donation before elective surgery has been widely endorsed as good transfusion practice. Although only 6 percent of patients undergoing elective orthopedic surgery are unable to donate 3 autologous units, 40 percent cannot donate 4 units because they become anemic [1,2]. According to the results of our study this must be due to different problems in bone marrow dynamics, which cannot be overcome by unselected use of human recombinant erythropoietin alone [3].

Adult↗
PubMed1991

Photoaffinity labeling of dog pancreas microsomes with 8-azido-ATP inhibits association of nascent preprolactin with the signal sequence receptor complex.

Transport of bovine preprolactin into dog pancreas microsomes involves a microsomal protein which is sensitive to photoaffinity labeling with azido-ATP and which is distinct from the ATP-binding protein, immunoglobulin heavy chain binding protein. Here we addressed the question of what stage of preprolactin transport is affected. Thus a nascent presecretory protein which is related to preprolactin, termed ppl-86mer, was employed. Here we show that the nascent preprolactin did not become associated with the alpha-subunit of the signal sequence receptor complex after photoaffinity labeling of microsomes with azido-ATP. Therefore, we conclude that the microsomal protein which is sensitive to photoaffinity labeling with azido-ATP acts prior to the signal sequence receptor complex.

Adenosine Triphosphate↗
PubMed1991

Autoantibodies against CD4 cells are associated with CD4 helper defects in human immunodeficiency virus-infected patients.

To investigate whether autoantibodies against CD4-positive lymphocytes might induce helper dysfunction, autoantibody formation and T-cell function was examined simultaneously in 61 hemophilia patients. Twenty patients were human immunodeficiency virus (HIV)-negative, 26 HIV-positive stage CDC II or III, and 15 were HIV-positive stage CDC IV. T lymphocytes, CD4-positive, or CD8-positive T subsets were cocultured with B lymphocytes and pokeweed mitogen (PWM) for 6 days and Ig-secreting cells were assessed in a reverse hemolytic plaque assay. The presence of IgM, IgG, C3d, or gp120 on the surface of T cells or T subsets was analyzed by flow cytometry. Autoantibodies against CD4-positive T cells were not detected in controls or HIV-negative patients, but were common in HIV-positive patients (20 of 41 patients). In patients with autoantibodies we found an increased incidence of CD4 helper defects (P less than .0001 in CDC II or III patients; P less than .02 in CDC IV patients). 12 of 13 patients with IgM autoantibodies and 4 of 4 with IgG autoantibodies showed CD4 helper defects. Complement fixation had no relevance. Autoantibody formation against CD4 cells was not due to increased in vivo B-cell stimulation (spontaneous plaque formation: 611 +/- 204 PFC/10(6) B cells in autoantibody-negative patients v 650 +/- 202 PFC/10(6) B cells in autoantibody-positive patients; not significant). Thus, our results suggest that autoantibody formation is not caused by a general state of in vivo B-cell activation. Rather, the production of autoantibodies appears to coincide with defects in B-cell proliferation or differentiation, as shown by reduced mitogen-stimulated B-cell responses in CDC II and III patients (P less than .05). Autoantibodies against CD4 cells appear to be involved in the pathogenesis of CD4 helper defects of HIV-infected patients.

Antigens, CD↗
PubMed1991

Hemodynamic and neuroendocrine response to acute administration of the phosphodiesterase inhibitor BM14.478 in patients with congestive heart failure.

The benzimidazol analogue BM14.478 is a phosphodiesterase inhibitor with both vasodilator and positive inotropic properties. Hemodynamic parameters and plasma hormone levels of 8 patients (1 female, 7 male) with chronic congestive heart failure NYHA Classes II-IV (1 patient with coronary artery disease, 7 patients with primary dilated cardiomyopathy) were assessed before and until 6 h after the intravenous application of 1.0 mg BM14.478. There was a significant decrease of mean pulmonary artery pressure (28 +/- 11 vs. 23 +/- 11 mmHg; p less than 0.05), mean right atrial pressure (8.6 +/- 5.2 vs. 5.0 +/- 4.7 mmHg; p less than 0.02), and systemic vascular resistance (1651 +/- 484 vs. 1206 +/- 252 dynes.s.cm-5; p less than 0.05) as early as 10 min after injection of BM14.478. Pulmonary vascular resistance also was reduced (128 +/- 86 vs. 61 +/- 39 dynes.s.cm-5, 30 min after injection; p less than 0.02). Simultaneously there was a significant increase of cardiac index (2.3 +/- 0.7 vs. 3.1 +/- 0.8 l.min-1.m-2, 10 min after injection; p less than 0.02), and stroke volume index (28.8 +/- 11.7 vs. 33.9 +/- 8.5 ml.min-1.m-2; 30 min after injection; p less than 0.05). Although mean heart rate did not change significantly, some patients reacted with a transient increase. There was also a slight but insignificant increase of the double product. No serious side effects were observed. The hemodynamic improvement was followed by a delayed reduction of plasma levels of epinephrine (51 +/- 20 vs. 41 +/- 21 pg/ml; p less than 0.02; 30 min after injection) and atrial natriuretic peptide (229 +/- 283 vs. 121 +/- 168 pg/ml; p less than 0.05; 1 h after injection). Mean levels of plasma norepinephrine, however, did not change significantly and individual responses showed large variations, which could not be predicted by the behavior of the hemodynamic parameters. Three of eight patients (2 of these with elevated baseline filling pressures) even showed a marked increase of plasma norepinephrine levels after BM14.478. Response of plasma renin activity and plasma vasopressin levels to BM14.478 also was heterogeneous. According to the results of this study, acute administration of the phosphodiesterase inhibitor BM14.478 has an immediate beneficial hemodynamic effect in patients with severe congestive heart failure by reducing both preload and afterload, and by increasing cardiac index and stroke volume. However, this improvement of hemodynamic parameters is not necessarily accompanied by a favorable short-term response of plasma hormones, and therefore does not allow any conclusions on survival of these patients.

Adult↗
PubMed1991

A microsomal protein is involved in ATP-dependent transport of presecretory proteins into mammalian microsomes.

Ribonucleoparticle (i.e. ribosome and SRP)-independent transport of proteins into mammalian microsomes is stimulated by a cytosolic ATPase which involves proteins belonging to the hsp70 family. Here we addressed the question of whether there are additional nucleoside triphosphate requirements involved in this transport mechanism. We employed a purified presecretory protein which upon solubilization in dimethyl sulfoxide and subsequent dilution into an aqueous buffer was processed by and transported into mammalian microsomes in the absence of the cytosolic ATPase. Membrane insertion of this precursor protein was found to depend on the hydrolysis of ATP and to involve a microsomal protein which can be photoaffinity inactivated with azido-ATP. Furthermore, a microsomal protein with a similar sensitivity towards photoaffinity modification with azido-ATP was observed to be involved in ribonucleoparticle-dependent transport. We suggest that a novel microsomal protein which depends on ATP hydrolysis is involved in membrane insertion of both ribonucleoparticle-dependent and -independent precursor proteins.

Adenosine Triphosphatases↗