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51.
Mutations in the gene encoding pejvakin, a newly identified protein of the afferent auditory pathway, cause DFNB59 auditory neuropathy 总被引:5,自引:0,他引:5
Delmaghani S del Castillo FJ Michel V Leibovici M Aghaie A Ron U Van Laer L Ben-Tal N Van Camp G Weil D Langa F Lathrop M Avan P Petit C 《Nature genetics》2006,38(7):770-778
Auditory neuropathy is a particular type of hearing impairment in which neural transmission of the auditory signal is impaired, while cochlear outer hair cells remain functional. Here we report on DFNB59, a newly identified gene on chromosome 2q31.1-q31.3 mutated in four families segregating autosomal recessive auditory neuropathy. DFNB59 encodes pejvakin, a 352-residue protein. Pejvakin is a paralog of DFNA5, a protein of unknown function also involved in deafness. By immunohistofluorescence, pejvakin is detected in the cell bodies of neurons of the afferent auditory pathway. Furthermore, Dfnb59 knock-in mice, homozygous for the R183W variant identified in one DFNB59 family, show abnormal auditory brainstem responses indicative of neuronal dysfunction along the auditory pathway. Unlike previously described sensorineural deafness genes, all of which underlie cochlear cell pathologies, DFNB59 is the first human gene implicated in nonsyndromic deafness due to a neuronal defect. 相似文献
52.
FGF-2/FGFR信号转导途径与肿瘤的关系及在乳腺癌发生中的作用 总被引:2,自引:0,他引:2
碱性成纤维细胞生长因子(FGF-2)是一种能调节细胞分裂、增殖、迁移及分化的多效生长因子. 研究表明, FGF-2在肿瘤生长和新血管生成中起重要的作用. FGF-2诱导的生物学效应很大程度上是依赖于TPK受体(酪氨酸激酶受体)和胞内二级信使分子(mitogen activted protein kinase)等蛋白分子组成的功能性信号转导网络来实现的, 该网络中不同信号转导通路的活化状态对应着各种不同的生物学效应. 本文将阐述在肿瘤及乳腺癌发生过程中FGF-2诱导的信号转导途径的作用机理方面的研究进展. 相似文献
53.
Mouquet H Scheid JF Zoller MJ Krogsgaard M Ott RG Shukair S Artyomov MN Pietzsch J Connors M Pereyra F Walker BD Ho DD Wilson PC Seaman MS Eisen HN Chakraborty AK Hope TJ Ravetch JV Wardemann H Nussenzweig MC 《Nature》2010,467(7315):591-595
During immune responses, antibodies are selected for their ability to bind to foreign antigens with high affinity, in part by their ability to undergo homotypic bivalent binding. However, this type of binding is not always possible. For example, the small number of gp140 glycoprotein spikes displayed on the surface of the human immunodeficiency virus (HIV) disfavours homotypic bivalent antibody binding. Here we show that during the human antibody response to HIV, somatic mutations that increase antibody affinity also increase breadth and neutralizing potency. Surprisingly, the responding naive and memory B cells produce polyreactive antibodies, which are capable of bivalent heteroligation between one high-affinity anti-HIV-gp140 combining site and a second low-affinity site on another molecular structure on HIV. Although cross-reactivity to self-antigens or polyreactivity is strongly selected against during B-cell development, it is a common serologic feature of certain infections in humans, including HIV, Epstein-Barr virus and hepatitis C virus. Seventy-five per cent of the 134 monoclonal anti-HIV-gp140 antibodies cloned from six patients with high titres of neutralizing antibodies are polyreactive. Despite the low affinity of the polyreactive combining site, heteroligation demonstrably increases the apparent affinity of polyreactive antibodies to HIV. 相似文献
54.
Diffusion loading conditions determine recovery of protein synthesis in electroporated P3X63Ag8 cells 总被引:2,自引:0,他引:2
Using the suspension cell line P3X63Ag8 we have studied the impact of the composition of the diffusion medium on cellular protein synthesis under standard electroporation conditions in TBS-Na. This buffer contains the high saline concentration usually present in electroporation-mediated DNA transfection. Electroporation in the presence of TBS-Na resulted in an immediate shut-off of protein synthesis, even though both FITC-dextran (Mr 40 kD) and Semliki Forest virus core protein (Mr 33 kD) were incorporated efficiently into the cytoplasm across the electropores at 0 degrees C. Subsequent resealing of the pores was completed after a 5-min incubation at 37 degrees C. When compared with control cells, overall protein synthesis of electroporated cells recovered slowly to resume a 30% activity after 1 h of incubation at 37 degrees C. We have determined optimal conditions for diffusion loading (which necessitates the presence of ATP, GTP, amino acids, K+, Mg2+, and Ca2+) and resealing (in the presence of K+, Mg2+, and Ca2+), leading to a full and lasting recovery of protein synthesis within 5 min after pore closure. 相似文献
55.
M. R. Michel M. Elgizoli H. Koblet Ch. Kempf 《Cellular and molecular life sciences : CMLS》1988,44(3):199-203
Summary Using the suspension cell line P3X63 Ag8 we have studied the impact of the composition of the diffusion medium on cellular protein synthesis under standard electroporation conditions in TBS-Na. This buffer contains the high saline concentration usually present in electroporation-mediated DNA transfection. Electroporation in the presence of TBS-Na resulted in an immediate shut-off of protein synthesis, even though both FITC-dextran (Mr 40 kD) and Semliki Forest virus core protein (Mr 33 kD) were incorporated efficiently into the cytoplasm across the electropores at 0°C. Subsequent resealing of the pores was completed after a 5-min incubation at 37°C. When compared with control cells, overall protein synthesis of electroporated cells recovered slowly to resume a 30% activity after 1 h of incubation at 37°C. We have determined optimal conditions for diffusion loading (which necessitates the presence of ATP, GTP, amino acids, K+, Mg2+, and Ca2+) and resealing (in the presence of K+, Mg2+, and Ca2+), leading to a full and lasting recovery of protein synthesis within 5 min after pore closure. 相似文献
56.
Sequential interplay between BAG6 and HSP70 upon heat shock 总被引:1,自引:1,他引:0
A. Corduan S. Lecomte C. Martin D. Michel F. Desmots 《Cellular and molecular life sciences : CMLS》2009,66(11-12):1998-2004
57.
58.
This paper presents the evaluation results of protective performance of the respirators (full face supplied-fresh air respirators
and half-mask active charcoal filter) and personal exposure measurement (Infacepiece sampling) in a Belgian viscose rayon
factory. With in-facepiece sampling technique and personal sampling method, we measured the CS2 concentrations inside and outside of the different respirators. We found two kinds of the respirators have significant effect
on decreasing the CS2 exposure level for the subject, especially for the spinners. Full face supplied-fresh air respirator have good protective
effect for the spinners and have limit protection for the high exposure job although the PF value is more than 10. It still
need to improve more. In-facepiece sampling for all the subjects exposed to CS2 in the factory found most subjects have exposed to low CS2 concentration, most exposure levels were under the control range, but sulfuror are high exposure, the exposure level is higher
than ACGIH TLV value.
Supported by the Belgian Science Research Office, (DWTC, Belgium) under contact number ST/02/034
Tan Xiaodong: born in 1963, Associate professor, Medical doctor and Master of Public Health 相似文献
59.
Varentropy is used as a general measure of probabilistic uncertainty for a complex network, inspired by the first and second laws of thermodynamics, but not limited to the equilibrium system. By exploring the relationship between the varentropy of the scale free distribution and the exponent of power laws as well as network size, we get the optimal design of a scale-free network against random failures. The behaviors of varentropy and the Shannon entropy of double Pareto law degree distribution are analyzed to compare their usefulness. Our conclusion is that varentropy is suitable and reliable. 相似文献
60.
Lovis C Mayor M Pepe F Alibert Y Benz W Bouchy F Correia AC Laskar J Mordasini C Queloz D Santos NC Udry S Bertaux JL Sivan JP 《Nature》2006,441(7091):305-309
Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star. 相似文献