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Biomedical subjects

M Becker

Publications and source records attributed to M Becker.

At least 271 records · Page 15Linked to original sources
PubMed1991

Ultrastructural localization of gold-labeled anti-IgM-antibodies and type A retrovirus particles in endoplasmic cisternae and vesicles of IgM-producing human B cell hybridomas.

Simultaneous appearance of IgM and type A retro-virus particles in endoplasmic cisternae and vesicles of human hybridomas has been demonstrated for the first time by immunogold-labeling at ultrastructural level. A suspected link between type A particle and IgM gene-expression in hybridoma cells could not be substantiated in this study.

Animals↗
PubMed1991

[Hematologic features in imported malaria. Value for the diagnosis of forms with low parasitemia].

Blood cell counts were performed on blood samples from 37 patients with imported malaria using three different blood analyzers (Coulter STKR, Coulter VCS and Technicon H1). Results were controlled by direct microscopic examination. Anemia, leukopenia, thrombocytopenia, or abnormalities of the leukocyte differential count were found in 32, 24, 30 and 92% of patients, respectively. The automatic analyzers gave alert messages for 70 to 75% of specimens, including specimens from ten patients with low parasitemias. These abnormalities should prompt careful analysis of blood smears when drug-resistance is suspected.

Adolescent↗
PubMed1991

[Social support and its relation to physical and emotional findings in Crohn's disease patients].

It was the aim of the present study to identify correlations between social, psychological and physical findings in 57 unselected patients with Crohn's disease from a gastroenterological outpatient department. Social support was registered using the confidant rating and the social network using a network questionnaire. Additional internal-medical and psychodiagnostic test instruments were used for a specific description of the sample. Anxieties, depressive moods and emotional lability were significantly less pronounced in patients with a confidant than in those without or with a less supportive partner. And the former also seemed to be more able to adequately cope with the disease than the patients of the other groups. With respect to the physical findings, the differences between the groups were less pronounced: Nevertheless, patients who were supported by a partner tended to show lower activity levels for Crohn's disease (Best index) than the others. The results obtained by the network questionnaire were less specific but altogether confirmed the results of the confidant rating. The study confirms the results of comparable investigations done in other clinical patient groups. The construct of social support is discussed critically with respect to psychoanalytical and family-dynamic concepts.

Adaptation, Psychological↗
PubMed1991

[Studies in riding arenas and on different riding path surfaces with respect to respiratory tract contamination in horses. Air hygiene studies in riding arenas].

Using the direct sedimentation method, the air pollution with fungal spores was measured in indoor riding arenas and compared to horse stables, outside riding arenas and covered sport courts. Depending on the location of indoor arenas and stables, the presence of "dust-nests", the number of horses ridden, and the moisture of the tread layer, an air pollution was measured which was equivalent to that in stables except at times of feeding and straw-giving. Outside and in sport arenas a low air pollution was found. Recommendations are given, regarding optimum air hygiene especially for horses with chronic and subclinical respiratory conditions.

Air Microbiology↗
PubMed1990

Fetal alcohol syndrome: a description of oral motor, articulatory, short-term memory, grammatical, and semantic abilities.

Formal communication skills assessments were completed on eight children with diagnosed forms of fetal alcohol syndrome (FAS) ages four and one-half to nine and one-half years. Non-FAS children ages three and one-half to six and one-half years matched for ethnic background, living situation, and nonverbal cognitive ability served as controls. All but one of the FAS subjects demonstrated abnormalities of the speech mechanism within at least one major valve along the vocal tract. Mental age inconsistent articulation abilities were found in three FAS subjects when matched for nonverbal cognitive ability. The FAS children exhibited mental age inconsistent abilities in the comprehension and use of grammatical markers both in repetition and in spontaneous language tasks. Further, the FAS subjects also demonstrated reduced capacity to process and store critical elements when compared with non-FAS children. Clinical implications for the assessment of children with FAS are outlined.

Articulation Disorders↗
PubMed1990

HIV-1 infection in a cohort of haemophilic patients.

The course of HIV infection in 53 haemophilic patients aged 5-20 years was evaluated by clinical examination and laboratory tests. During the evaluation time (median 30 months) two patients died of AIDS and 32 patients (60%) deteriorated when assessed by the Brodt-Helm classification. Nineteen patients (37%) had decreased absolute helper cell counts (less than 500 CD4 positive cells/microliters), and 45 patients (87%) had reduced helper cell to lymphocyte ratios (less than 0.35). HIV-1 was isolated from peripheral lymphocytes in 29 of 46 patients. As the disease progressed the number of positive viral cultures increased. Considerable progression of the HIV infection was seen in haemophilic children and adolescents during the median evaluation period of 30 months. The transition from symptomless HIV infection to immunodeficiency was easily recognised. A lowered ratio of helper cells to lymphocytes seems to be a useful marker of the beginning of the deterioration of the immune system.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Development of a mitoxantrone-resistant P 388 in vivo: approaches to overcome resistance.

A normally, relatively sensitive P 388 developed resistance within few passages (P 388/Mitox) by in vivo treatment with suboptimal doses (1 mg/kg i.v.) of mitoxantrone. This resistance remained stable over 50 generations without further drug treatment. Immunization with irradiated cells (30 Gy) 7 days before tumor challenge led to partial rejection, proving that there was a higher immunogenicity of the resistant line in comparison to the parenteral P 388 line. The P 388/Mitox showed cross-resistance towards doxorubicin, daunorubicin and vincristine. Cis-DDP and bleomycin had in the resistant line significantly better antineoplastic efficacy than in the source P 388 and should be taken into consideration as second-line therapy following development of clinical mitoxantrone resistance. Nifedipine, a calcium channel blocker, and the immunosuppressive agent ciclosporin A were able to overcome resistance partially, but the mechanisms are still unclear. The P 388/Mitox can be considered as an interesting in vivo model for further research concerning resistance mechanisms and reversal of resistance.

Animals↗
PubMed1990

Biospecific adsorbents on the basis of chloroformate-activated bead cellulose.

Carbohydrate-derived polymers are activated by the chloroformate N-chlorocarbonyloxy-5-norbornene-2.3-dicarboximide (ClCOONB). The advantages of this activation method are presented. The application of bead cellulose as adsorbent for biomedical and biotechnological purposes is demonstrated. Examples for immunoglobulin purification, streptavidin isolation, and biotransformation of porcine insulin are given.

Bacterial Proteins↗
PubMed1990

Evaluation of the white blood cell differential given by the new analyser Coulter STKS in both hematological and non-hematological patient groups.

The White Blood Cell differential given by the new analyser Coulter STKS was studied in a group of hospitalized patients originating from non-hematological departments (group 1; n = 290) and a group of patients suffering from an hematological disease (group 2; n = 106) with blood smear abnormalities. A good relationship between the reference method and the STKS results was shown in 200 patients without hematological abnormalities. Both sensitivity and reliability of alarms were evaluated in both groups. In group 1, we noticed respectively: 208 true negative, 40 true positive, 7 false negative, 35 false positive. Six of the seven false negative results were related to the presence of a slight myelemia without hematological significance, one to the presence of small quantity of circulating blasts with a leuconeutropenia. In group 2, all abnormalities seen on the blood smear were detected by the Coulter STKS either by an alarm message (93 cases) or by an increase of the lymphocyte population (9 cases) in some chronic lymphocyte leukemias, or by an important leuconeutropenia (4 cases) in acute treated leukemias. The results of the White Blood Cell differential performed with the Coulter STKS exhibited a good relationship with the reference method for normal bloods and a good reliability for detection of abnormal cells.

Erythrocyte Count↗
PubMed1990

Determination of antineoplastic activity and toxicity of tumor necrosis factor (TNF) in animal experiments. Correlation to clinical findings.

Because of the deep evolutionary roots which macrophages and their products have, it should be possible to relate effects of the biological response modifier TNF observed in cancer patients with those determined in animal species. We have tested this hypothesis both with regard to antitumor efficacy and unwanted side-effects in murine tumor models. In the intramuscularly (i.m.) transplanted B16 melanoma, TNF had both after intratumoral (i.t.) and intravenous (i.v.) administration (qd 7-11, 14-17) a significant and dose-dependent effect on tumor growth. This effect was transitory and led only to a moderate increase in survival time of the animals. This correlates well with the also unsatisfactory clinical antineoplastic activity of TNF. From the measurement of body weight reduction, WBC counts, platelets, recalcification time, transaminases and body temperature in tumor bearing mice it can be concluded that there are close similarities to the side-effects observed in patients, although the level and/or time course of the noticed changes were differently expressed. In principle, it seems possible to predict clinical effects of biological response modifiers in animal experiments even if not all mechanisms are clearly understood.

Animals↗
PubMed1990

Rapid, simple, and reliable doctor's office test for antibodies to human immunodeficiency virus 1 in serum.

This "Unit Test Method" assay for detecting anti-human immunodeficiency virus 1 antibody is suitable for nonlaboratory testing and has a sensitivity comparable with that of present enzyme immunoassay methods. The method does not require instrumentation, gives a result in less than 15 min, and incorporates a procedural control. Little technical expertise and hands-on time are required of the user.

Colorimetry↗
PubMed1990

[Adverse effects of cyclosporin A with special reference to the peripheral nervous system].

Since the introduction of Cyclosporine A (CsA) in 1972, several studies have focused on its effects on experimental autologous peripheral nerve transplants. Although several studies have reported neurotoxicity of CsA in the central nervous system, no such data exist regarding the peripheral nervous system. The present study focuses on the effects of CsA in the therapeutic and toxic doses on axon regeneration, particularly the rate and quality of axon regeneration. Autologous nerve transplantation was performed in Lewis rats and axon regeneration evaluated clinically (motor function, body weight), electroneurographically and histologically. In transplanted nerves, even high doses of CsA (30 mg/kg bodyweight) did not lead to delayed or impaired axon regeneration. Long-term application in normal peripheral nerves did however cause axon degeneration with edema and vacuolisation of myelin sheaths, retraction of myelin sheaths from the node of Ranvier, and marked enhancement of the Schmidt-Lantermann incisures. As neurological side effects such as tremor and paresthesia have been reported under application of CsA in man, the above data might be of clinical relevance.

Animals↗
PubMed1989

Combined segregation and linkage analysis for IDDM and HLA-DR under several ascertainment assumptions.

Combined segregation and linkage analysis of the Genetic Analysis Workshop 5 (GAW5) data suggests a complex basis for susceptibility to insulin-dependent diabetes mellitus (IDDM). One susceptibility gene, linked to the HLA-DR region, is additive on the liability scale (d = .49 +/- .15, t = 2.9 +/- .6) with a gene frequency q = .30 +/- .03. A second locus, with a gene frequency of q = .07 +/- .02, which is recessive and unlinked to HLA, is also suggested by the analysis. The ascertainment correction used has little effect on the results, presumably because most of the information comes from the cosegregation of HLA alleles and disease status. The results are consistent with a direct involvement of the HLA-DR region in susceptibility, but are not a proof of it.

Computer Simulation↗