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M Lapidot

Publications and source records attributed to M Lapidot.

44 records · Page 3Linked to original sources
PubMed1986

Protein blot analysis of virus receptors: identification and characterization of the Sendai virus receptor.

Receptors for Sendai virions in human erythrocyte ghost membranes were identified by virus overlay of protein blots. Among the various erythrocyte polypeptides, only glycophorin was able to bind Sendai virions effectively. The detection of Sendai virions bound to glycophorin was accomplished either by employing anti-Sendai virus antibodies or by autoradiography, when 125I-labeled Sendai virions were used. The binding activity was associated with the viral hemagglutinin/neuraminidase (HN) glycoprotein, as inferred from the observation that the binding pattern of purified HN glycoprotein to human erythrocyte membranes was identical to that of intact Sendai virions. No binding was observed when blots, containing either human erythrocyte membranes or purified glycophorin, were probed with the viral fusion factor (F glycoprotein). Active virions competed effectively with the binding of 125I-labeled Sendai virions (or purified HN glycoprotein), whereas no competition was observed with inactivated Sendai virus. The results of the present work clearly show that protein blotting can be used to identify virus receptors in cell membrane preparations.

Animals↗
PubMed1984

The mechanism of gonadotropin induced desensitization of rat ovarian adenylate cyclase in the cell free state and the role of GTP in this process.

Gonadotropin induced desensitization of adenylate cyclase (AC) in purified rat ovarian plasma membrane preparations requires a 40 min preincubation period with that same hormone and guanosine triphosphate (GTP). This phenomenon can be demonstrated for the response of AC to luteinizing hormone (LH), follicle stimulating hormone (FSH) and human chorionic gonadotropin (hCG), all of which display a strongly homologous rather than heterologous type of desensitization. In the desensitized state the enzyme retains its capacity to fully respond to stimulation by NaF. It is also shown that a possible basis for reduced responsiveness of AC to hormones in the desensitized state stems from the fact the hormone can bind but no longer accelerates the "GTP-regulatory cycle". Taken together these findings support the view, that the decreased ability of the hormone receptor in regulating AC activity in the desensitized state, results from a temporary change induced by the hormone in the receptor itself.

Adenylyl Cyclases↗
PubMed1980

Red blood cell membrane and serum sialic acid in relation to erythrocyte sedimentation rate.

Sialic acid was determined in red blood cell (RBC) membrane and in serum, and correlated to erythrocyte sedimentation rate (ESR). For this purpose blood samples were obtained from 57 patients, regardless of their pathological condition, and divided into groups according to the ESR. 15 blood samples obtained from health individuals whose ESR was lower than 20 mm/h served as controls. Sialic acid was released from RBC membranes obtained by hemolysis, and from serum glycoproteins precipitated with ethanol by treatment with 0.1 N HCl at 80 degrees C for 1 h. The results showed the sialic acid contents of both membranes and serum to be higher in most of the groups with elevated ESR, as compared to the control group, although no quantitative correlation was noticed. Statistical evaluation showed highly significant differences between the group of pathological samples as a whole and the control group in the sialic acid content of both RBC membranes and sera.

Blood Sedimentation↗
PubMedDate not supplied

Topical Biafine and Lipiderm for the prevention of radiation dermatitis: a randomized prospective trial.

We evaluated the effects of Biafine and Lipiderm ointments in preventing radiation dermatitis. The study population included 74 patients after conservative surgery for early breast carcinoma who were referred for adjuvant external beam irradiation. Patients were randomized to receive Biafine or Lipiderm or no treatment. Both study preparations were applied twice daily, starting 10 days before onset of radiotherapy and continuing until 10 days after its completion. The skin treatment was upgraded, if clinically necessary, to steroids (grade 3), antibiotics (grade 4), or pause in therapy (grade 5). Success of treatment was evaluated according to the maximal level of skin treatment, the number of gaps in radiation therapy, the impression of the patients and the subjective skin reaction, and scores of the study nurse and radiotherapist. The three groups were comparable for all clinical features, except for a lower mean age of the Biafine group. Comparative analysis of the results showed no advantage for either preparation compared to the control arm other than maximal treatment level required for a skin reaction (mean 1.7 and 1.6 vs. 2.2), which did not reach statistical significance (p=0.145). Nevertheless, 86% of the patients in both the Biafine and Lipiderm arms expressed satisfaction with the respective ointments. In conclusion, neither Biafine nor Lipiderm seems to have a radioprotective effect.

Administration, Topical↗