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排序方式: 共有10000条查询结果,搜索用时 46 毫秒
41.
42.
Viollet L Zarhrate M Maystadt I Estournet-Mathiaut B Barois A Desguerre I Mayer M Chabrol B LeHeup B Cusin V Billette De Villemeur T Bonneau D Saugier-Veber P Touzery-De Villepin A Delaubier A Kaplan J Jeanpierre M Feingold J Munnich A 《European journal of human genetics : EJHG》2004,12(6):483-488
Chronic distal spinal muscular atrophy (Chronic DSMA, MIM (*)607088) is a rare autosomal recessive disorder characterized by a progressive motor weakness and muscular atrophy, predominating in the distal parts of the limbs. A form of Chronic DSMA gene has been previously mapped to chromosome 11q13 in the 10.3 cM interval defined by loci D11S1889 and D11S1321. By linkage analysis in 12 European Chronic DSMA families, we showed that a disease gene maps to chromosome 11q13.3 (Z(max)=6.66 at theta=0.00 at the DSM4 locus) and suggested that this condition is genetically homogeneous. Recombination events allowed us to reduce the genetic interval to a 2.6 cM region, telomeric to the IGHMBP2 gene, excluding this gene as the disease causing gene in Chronic DSMA. Moreover, partial linkage disequilibrium was found between three rare alleles at loci D11S1369, DSM4 and D11S4184 and the mutant chromosome in European patients. Analysis of the markers at these loci strongly suggests that most Chronic DSMA chromosomes are derived from a single ancestor. Refinement of the Chronic DSMA locus will hopefully allow to test candidate genes and lead to identification of the disease-causing mutations. 相似文献
43.
Relationship between ROS production, apoptosis and DNA denaturation in spermatozoa from patients examined for infertility 总被引:24,自引:0,他引:24
Moustafa MH Sharma RK Thornton J Mascha E Abdel-Hafez MA Thomas AJ Agarwal A 《Human reproduction (Oxford, England)》2004,19(1):129-138
BACKGROUND: The aim of this study was to examine the role of apoptosis and reactive oxygen species (ROS) in inducing DNA damage in ejaculated spermatozoa. METHODS: We examined ejaculated spermatozoa from 31 patients examined for infertility and 19 healthy donors for apoptosis, production of ROS and DNA damage using annexin V binding, chemiluminescence assay and sperm chromatin structure assay. RESULTS: The percentage of spermatozoa that underwent apoptosis in the whole ejaculate and mature fraction was higher in the patients than in the donors (P<0.001 and P=0.009, respectively). Levels of ROS in the whole ejaculate and immature fraction were higher in the patients than in the donors (P=0.002 and P=0.009). Apoptosis was significantly correlated with ROS within patients in the whole ejaculate [r (95% confidence interval)=0.53 (0.19-0.86)] and in the mature [0.71 (0.39-1.00)] and immature spermatozoa [0.75 (0.45-1.00)]. Only apoptosis and the DNA fragmentation index (DFI) were significantly correlated within patients in the whole ejaculate [0.57 (0.18-0.97)]. CONCLUSIONS: DNA damage may be induced by oxidative assault. Apoptosis may not contribute significantly to the DNA damage. 相似文献
44.
Bernard Boutevin Grard Rigal Mohammed El Asri Tahar Lakhlifi 《Macromolecular chemistry and physics.》1995,196(3):891-902
In the case of water soluble polymers, the use of size exclusion chromatography (SEC) for the determination of the molecular weight involves numerous difficulties. In order to analyse and determine the molecular weight of acrylic acid telomers we have first tried to obtain a satisfactory and reproducible separation. In this particular case, low-molecular-weight standards are not commercially available. Therefore, we decided to prepare standards based on acrylic acid, either by telomerization with a fluorinated telogen or by polymerization with an initiator bearing a fluorinated group. A calibration curve was obtained from the standards. Telomers of acrylic acid with thioglycolic acid were analysed. This is a general method for determination of DP n by SEC when there is no standard for the polymers. It can be used in a wide range of DP n from 1 to 700. 相似文献
45.
Fine-needle aspiration biopsy findings in three cases of chromophobe cell carcinoma are described and correlated with histologic and ultrastructural observations. In addition, comparisons are made with three cases each of oncocytoma and granular cell carcinoma. The cells in aspiration smears from chromophobe cell carcinoma closely correlated with histologic pattern of three cell types which were not present in oncocytomas and granular cell carcinomas. These cells had prominent cell borders, and their cytoplasm was either opaque and granular (type I) or variably translucent and reticular (type II and III). Ultrastructurally, the translucent areas within the cytoplasm contained large numbers of microvesicles which were unique to chromophobe cell carcinoma and were not seen in other neoplasms. Fine-needle aspiration may be used to diagnose chromophobe cell carcinoma and distinguish it from other related renal neoplasms. © 1995 Wiley-Liss, Inc. 相似文献
46.
Lapierre JM Sanlaville D Kang J Ozilou C Le Lorc'h M Waill MC Prieur M Colleaux L Munnich A Turleau C Benkhalifa M Mohammed M Vekemans M Romana S 《Annales de biologie clinique》2004,62(2):203-212
Comparative genomic hybridization on a microarray (microarray-CGH) allows to detect genomic chromosome imbalances. In order to assess its value to detect small chromosome imbalances observed in a clinical setting, using a DNA chip available commercially (Spectral Genomics, Houston, Texas, USA), we studied the DNA of 9 patients carrying a well characterized chromosome imbalance and the DNA of 11 patients where cytogenetic techniques such as high resolution banding karyotype, FISH using subtelomeric probes and comparative genomic hybridization on metaphase chromosomes conclude to a normal and/or balanced karyotype. A result was obtained for 19/20 patients. Failure of hybridization was observed for one patient. For all the other cases the sex of patients was correctly identified. Microarray-CGH was able to correctly diagnose the chromosome imbalance in 6/8 patients carrying such a defect i.e 9/11 imbalances (deletion or duplication) were detected. No chromosome imbalance was observed in 11 patients considered normal and/or balanced using cytogenetic techniques. Several clones were found to be polymorphic and required FISH studies to eliminate duplication or deletion. In conclusion, we think that this commercially available DNA chip might be useful to screen for chromosome imbalances. However, technical improvements are still necessary before using it in a clinical setting. Also, further studies are necessary to assess its sensitivity and specificity. 相似文献
47.
Omar Senhaji Jean Jacques Robin Mohammed Achoubi Bernard Boutevin 《Macromolecular chemistry and physics.》2004,205(7):951-957
Summary: The telomerization of 10‐undecenol with alkyl hydrogenphosphonate was studied in order to synthesize telomers of different molecular weights. The study showed that telomers from 10‐undecenol could be obtained despite the fact that the double bond has a low reactivity. The kinetic constant Kp2/KTe was determined to be 7 × 10?4 l · mol?1 · s?1 at 135 °C and the transfer constant CT was 0.057. These values are normal for a low activity telogen such as hydrogenphosphonate and for slightly reactive monomers like 10‐undecenol.
48.
Ameyaw MM Tayeb M Thornton N Folayan G Tariq M Mobarek A Evans DA Ofori-Adjei D McLead HL 《Journal of human genetics》2002,47(4):172-175
HER-2, a protooncogene located on chromosome 17q21, encodes a transmembrane glycoprotein (p185) with tyrosine kinase activity.
Alterations of the HER-2 gene have been implicated in the carcinogenesis and prognosis of breast cancer and other solid tumors. It is also a cancer-therapeutic
target for antibody-based therapy against the HER-2 protein. A single-nucleotide polymorphism (SNP) at codon 655, resulting in a G-to-A transition (Ile655Val) in the transmembrane
domain-coding region of this gene has been associated with an increased risk of breast cancer, particularly among younger
women. To understand the importance of this finding throughout the world, we evaluated this polymorphism in Ghanaian, Kenyan,
Sudanese, Caucasian, African–American, Saudi, and Filipino subjects using a polymerase chain reaction-restriction fragment
length polymorphism assay. The frequency of the Val allele, which is associated with increased breast cancer risk, was highly
variable between populations (0%–24%). Continental African populations had a lower frequency of the Val allele than did Saudi,
Chinese, Filipino, Caucasian, and African–American subjects. The data suggest that this SNP has variable frequency in different
ethnic groups. The findings in this study correspond with the lower incidence and lower risk of breast cancer in African women
compared with Caucasian and African–American women.
Received: December 13, 2001 / Accepted: January 16, 2002 相似文献
49.
Tachdjian G Aboura A Benkhalifa M Creveaux I Foix-Hélias L Gadisseux JF Boespflug-Tanguy O Mohammed M Labrune P 《American journal of medical genetics. Part A》2004,131(3):273-280
Genotype-phenotype correlation in women with an abnormal phenotype associated with a duplication of the long arm of the X chromosome remains unclear. We report on prenatal diagnosis and follow-up of a girl with an Xq duplication and dysmorphic features. The abnormal phenotype included growth retardation, hypotonia, and nystagmus. In order to improve the resolution of the cytogenetic analysis, we used both conventional and array-based comparative genomic hybridization to perform a global molecular cytogenetic analysis of the genome. These molecular cytogenetic analyses showed a direct duplication Xq21.1 --> q25 without other chromosomal abnormalities. This duplication was originating from the paternal X chromosome. Moreover, a skewed X-inactivation pattern was observed leading to a partial functional disomy of the chromosomal region Xq21.1q25. This report and review of the literature suggest that functional disomy for chromosome X could explain the abnormal phenotype. In prenatal diagnosis, this can have implication for patient management and genetic counseling. 相似文献
50.
Baris O Delettre C Amati-Bonneau P Surget MO Charlin JF Catier A Derieux L Guyomard JL Dollfus H Jonveaux P Ayuso C Maumenee I Lorenz B Mohammed S Tourmen Y Bonneau D Malthièry Y Hamel C Reynier P 《Human mutation》2003,21(6):656-656
The OPA1 gene, encoding a dynamin-related GTPase that plays a role in mitochondrial biogenesis, is implicated in most cases of autosomal dominant optic atrophy (ADOA). Sixty-nine pathogenic OPA1 mutations have been reported so far. Most of these are truncating mutations located in the GTPase domain coding region (exons 8-16) and at the 3'-end (exons 27-28). We screened 44 patients with typical ADOA using PCR-sequencing. We also tested 20 sporadic cases of bilateral optic atrophy compatible with ADOA. Of the 18 OPA1 mutations found, 14 have never been previously reported. The novel mutations include one nonsense mutation, 3 missense mutations, 6 deletions, one insertion and 3 exon-skipping mutations. Two of these are de novo mutations, which were found in 2 patients with sporadic optic atrophy. The recurrent c.2708_2711delTTAG mutation was found in 2 patients with a severe congenital presentation of the disease. These results suggest that screening for OPA1 gene mutations may be useful for patients with optic atrophy who have no affected relatives, or when the presentation of the disease is atypical as in the case of early onset optic atrophy. 相似文献