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A. Tchirkov Jacques-Olivier Bay David Pernin Yves-Jean Bignon Pascale Rio Maria Grancho Fabrice Kwiatkowski Michel Giollant Paul Malet Pierre Verrelle 《Human genetics》1997,101(3):312-316
In ataxia-telangiectasia (A-T) patients, mutations in a single gene, ATM, result in an autosomal recessive syndrome that embraces a variety of clinical features and manifests extreme radiosensitivity
and a strong predisposition to malignancy. Heterozygotes for the ATM gene have no clinical expression of A-T but may be cancer prone with a moderate increase in in vitro radiosensitivity. We
performed a blind chromosomal analysis on G2-phase lymphocytes from 7 unrelated A-T patients, 13 obligate A-T heterozygotes (parents of the patients), and 14 normal controls
following X-irradiation with 1 Gy in order to evaluate this cytogenetic method as a tool for detection of ATM carriers. Both A-T homozygotes and heterozygotes showed significantly increased levels of radiation-induced chromatid damage
relative to that of normal controls. These results show that the G2-phase chromosomal radiosensitivity assay can be used for the detection of A-T heterozygotes. In combination with molecular
genetic analyses, this test may be of value in studies of familial and sporadic cancers aimed at determination of the potential
involvement of ATM mutations in tumor risk or development.
Received: 5 May 1997 / Accepted: 26 August 1997 相似文献
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Michel Volovitch 《Journal of evolutionary biology》1996,9(2):253-260
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Analysis of the immune response towards the facultative intracellular bacterium, Brucella melitensis, was studied by immunoblotting after either isoelectric focusing (IEF) or sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A cytoplasmic extract (CPE) of Brucella melitensis was used as antigen to analyse the response in 17 sera from naturally infected goats. CPE analysed by IEF exhibited 25 proteins within the pH range of 4.35 to 6. Immunoblotting revealed most of the stained bands around pH 4.5-5.4. CPE analysed by SDS-PAGE showed more than 20 silver stained proteins in the molecular range of 16-18 kDa to 70 kDa but immunoblotting revealed only 1 to 6 bands according to the sera tested. Because proteins are preserved in their native state with IEF, in contrast to SDS-PAGE treatment, this technique may be best suited for analysis of the overall response to natural infection. 相似文献
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Inositol trisphosphate is known to mobilize calcium from internal stores in plant cells. However, with the exception of the vacuole, the largest plant cell compartment, organelles responsive to inositol trisphosphate have not been extensively identified. In this way, we have separated membrane vesicles from the same carrot microsomal fraction and identified them, both by marker enzyme activities and electron microscopy. These correspond to pure plasma membrane, pure tonoplast and mixed mitochondria, endoplasmic reticulum, Golgi membrane fractions. All the fractions accumulated calcium in a ATP-dependent manner and were tightly sealed. Inositol trisphosphate-dependent calcium releases were accurately measured only in fractions corresponding functionally and structurally to tonoplast, the vacuolar membrane. The process was dose-dependent and fairly specific for inositol trisphosphate. While highly significant, approximately 40% of the mobile calcium only may be released from tonoplast vesicles by inositol trisphosphate which remained basically intact during the release experiments. From these results it is concluded that the vacuole is the richest store of calcium directly mobilizable by inositol trisphosphate in plant cells, but inositol trisphosphate is not able to release the overall mobile vacuolar calcium. 相似文献
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Dorian Salin Pierre-Jean Arnoux Kambiz Kayvantash Michel Behr 《Computer methods in biomechanics and biomedical engineering》2016,19(14):1578-1582
In the field of biomechanics, the offer of models which are more and more realistic requires to integrate a physiological response, in particular, the controlled muscle bracing and the reflexes. The following work aims to suggest a unique methodology which couples together a sensory and motor loop with a finite element model. Our method is applied to the study of the oscillation of the elbow in the case of a biceps brachial stretch reflex. The results obtained are promising in the purpose of the development of reactive human body models. 相似文献
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