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Biomedical subjects

M Becker

Publications and source records attributed to M Becker.

At least 109 records · Page 6Linked to original sources
PubMed1991

Bead cellulose derivatives as supports for immobilization and chromatographic purification of proteins.

Characteristic data are presented for Divicell, a macroporous bead cellulose with excellent flow parameters. The preparation of Divicell derivatives and their properties are described with respect to their application as chromatographic supports. The ion exchangers Divicell DEAE and Divicell CM were manufactured in two types with different exclusion limits and an available capacity for proteins of up to 100 mg/ml gel. Divicell Blue is a bead cellulose with covalently bound Cibacron Blue F3G-A and was found to be a very suitable adsorbent for the selective separation and purification of human serum albumin. Activation of Divicell with sodium periodate, epichlorohydrin and 5-norbornene-2,3-dicarboximido carbonochloridate provided activated supports used for immobilization of ligands in organic solvents and in aqueous solutions. Coupling of amines, diamines, amino acids, carbohydrates and proteins is described. The immobilized ligands retained their biological activity as determined by their specific adsorption of proteins. Divicell alkyl derivatives were tested in hydrophobic interaction chromatography with bovine serum albumin as a model. Examples are presented of the application of Divicell derivatives to the purification of biomacromolecules such as immunoglobulins and lectins by affinity chromatography. The results were comparable to those obtained using the corresponding Sepharose-derived absorbents.

Animals↗
PubMed1991

Influence of type and extent of surgery on early results and survival time in glioblastoma multiforme.

We studied the influence of the type of surgery (microsurgery or macrosurgery) and extent (complete resection with lobectomy, complete resection alone, partial resection with lobectomy or partial resection alone) on early postoperative results and survival time in 118 consecutive patients who underwent surgery for glioblastoma multiforme. Early results were assessed by the Karnofsky score at 4 weeks postoperatively. Survival was compared using Kaplan-Meier curves and Mantel statistics. The median survival time (MST) after microsurgery (12.1 months) was significantly longer than that after macrosurgery (7.3 months). The longer survival after microsurgery was, however, largely attributable to better early results and a consequently higher proportion of patients who could undergo radiotherapy. Complete resection was superior to partial resection. Additional lobectomy did not appreciably influence the early results and the MST in completely resected tumours. So the MST after complete resection in the microsurgical group without lobectomy was 12.6 months, with lobectomy 12.9 months. In the macrosurgical group the respective values were 7.4 months without and 8.2 months with lobectomy. In incompletely resected tumours lobectomy worsened the early results compared to incomplete resection alone and led to a shorter MST.

Brain Neoplasms↗
PubMed1991

Are there antiendometrial antibodies in sera of women with endometriosis?

STUDY OBJECTIVE: To identify and characterize the antiendometrial tissue specific antibody response in endometriosis patients. DESIGN: Retrospective. SETTING: Industrial research laboratory. PATIENTS: Twenty untreated women with laparoscopically diagnosed endometriosis, 10 healthy women without symptoms of endometriosis, 12 women in whom laparoscopy failed to yield evidence of endometriosis, 10 healthy men, and 4 individuals with elevated titers of serum antinuclear antibodies. RESULTS: Several immunological methods have been employed including immunofluorescence, hemagglutination, enzyme-linked immunoabsorbent assays, and protein blotting. Contrary to reports in the literature, results of these analyses have failed to demonstrate the presence of detectable levels of antiendometrial immunoreactivity in sera from patients with endometriosis. CONCLUSION: The association of endometrial autoimmunity with endometriosis remains to be established.

Autoantibodies↗
PubMed1991

Regeneration of autologous and allogenic nerve grafts in a rat genetic model: preliminary report.

The authors report observations concerning rejection and regeneration processes of allogenic peripheral neural tissue, depending on different genetic mismatches in a rat model. Five groups representing different rat strains (n = 100) were subjected to orthotopic grafting of 2.5-cm segments of sciatic nerve. Combinations represented different genetic barriers, including the Major Histocompatibility Complex (MHC), a non-MHC, a subgroup (A) of the MHC, a group representing MHC plus non-MHC, and an autologous control group. Animals were examined after one, two, and 12 weeks; additional evaluations in some of the experimental groups were done at six and eight weeks. Regeneration in varying degrees was evident in all groups at 12 weeks.

Animals↗
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↗