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51.
HLA-B44 is the most frequent HLA-B allele in Caucasian populations. Several B44 subtypes, B*4402-B*4406, have been identified in individuals with this ethnic origin. Mismatches among B44 subtypes have been described as major targets for allogeneic responses in bone marrow transplantation. We have developed a PCR-SSO method, based on a B12- specific DNA amplification of exon 2 through exon 3 and subsequent non radioactive hybridization with eight probes, which allow us to discriminate all B12 homozygous combinations. We applied this method to determine the frequency of B44 subtypes in a Spanish population, as well as their HLA-A.-C.-DRB1,-DRB3/DRB4/DRB5.-DQA1 and -DQB1 associated haplotypes. A total of 141 healthy unrelated Spanish individuals and 31 B44-bearing haplotypes were investigated. Four B44 alleles were identified, B*4402 (33%), B*4403 (66%), B*4404 (0.7%), and B*4405 (0.7%). Haplotype analysis showed a clear differentiated distribution pattern for the two major B44 subtypes. B*4402 is associated with Cw5 (11/13) and A2 antigens (10/13). In contrast, B*4403 is mainly found together with DRB1*0701 (14/16). An inverted B*4402/B*4403 frequency in comparison with other European and North American Caucasian populations, revealed the existence of an extended haplotype diversity between populations of the same ethnic origin. Apart from anthropological studies, high resolution typing for HLA class I antigens presenting molecular polymorphism will be of great relevance in unrelated bone marrow transplantation.  相似文献   
52.
应用显微分光光度计测定15例鼻咽癌19处癌旁病变的上皮细胞核DNA含量并与浸润癌相比较。中、重度异型增生上皮细胞核DI及超过2.5c细胞的百分数处于单纯增生+轻度异型增生与浸润癌之间,3组DI及超过2.5c细胞的百分数差异显著。中、重度异型增生以非整倍体为主,其细胞核DNA含量组方图相似于浸润癌。从细胞核DNA含量角度来看,中、重度异型增生是重要的癌前病变。  相似文献   
53.
In this retrospective study 103 serum samples from 16 females with systemic lupus erythematosus (SLE), obtained during a mean follow-up time of 2 years, were investigated for the presence of anti-denatured [single-stranded (ss)] DNA antibodies of the IgG, IgM, and IgA classes. The anti-ssDNA antibodies were determined by an enzyme-linked immunosorbent assay (ELISA), and the results were expressed in three ways: as units derived from a single serum dilution and as two parameters,E andA, calculated from the dose-response curve,E being an estimate of the effective amount of antibodies andA a function of the reaction constant between the antigen and the antibody. The simultaneous occurrence of anti-ssDNA antibodies of all three immunoglobulin classes was seen most often in the patients with the shortest duration of the disease. Clinically active disease was found to correlate with high reaction constants of the IgA anti-ssDNA antibodies. There was also an association between the IgA anti-ssDNA antibody levels and the presence of nephritis. Great fluctuations in the amounts of effective antibodies of the IgG class were seen in seven patients, in six of whom changes in the disease activity also were seen. Changes in the disease activity were unaccompanied by fluctuations in the IgG anti-ssDNA levels in four patients; two of these patients were positive for antibodies against extractable nuclear antigens. We conclude that it is of value to express the results of the anti-ssDNA ELISA as a function of the dose-response curve when monitoring patients with SLE and that immunoglobulin class-specific determinations of anti-ssDNA antibodies may provide information about the disease activity in many patients with SLE.  相似文献   
54.
Chromophobe renal cell carcinoma (RCC) is a recently established subtype of RCC, which has rarely been reported in Japan. In this communication, the authors report two Japanese cases of chromophobe RCC together with the immunohistochemical findings. The tumors were composed of sheets and cribriform glands formed by tumor cells with cloudy and reticular cytoplasm. Ultrastructurally, the cytoplasm was filled with numerous microvesicles. The tumor cells were positive for cytokeratin, epithelial membrane antigen, and Tamm-Horsfall protein. Occasionally, LeuM1-positive cells were also noted. Vimentin was negative, unlike the usual RCC. Reactivity for peanut agglutinin was more frequent than that to Lotus tetragonolobus agglutinin. The results of this study suggest that the tumor cellq possessed phenotypes similar to the distal nephron rather than to the proximal tubular cells.  相似文献   
55.
Two cell lines designated IC KMS and D KMS were established from human adenovirus type 12 induced tumors of C3Hf/OK mouse. The cell lines retained the characteristics of the original tumor i.e., production of numerous C type and intracisternal A-type particles, integration of Adl2 El region DNA and amplification of the myc gene family. Chromosomal analysis revealed chromosome aberrations in both IC KMS and D KMS cells. The modal chromosome number of IC KMS cells was 54 and that of D-KMS cells was 48. Metacentric chromosomes and mini-chromosomes were found. Trisomy of chromosome 3, 7 and 12 was seen frequently in D KMS cells. Although DNA aneuploidy was revealed by flow cytometry, the DNA indices of these cells showed no relation to the copy number of integrated Adl2 DNA. These cells have been propagated by serial culture during the past 17 months. Production of endogenous virus particles is a unique characteristic of IC KMS and D KMS cells. These cell lines would be useful materials for examining the contribution of Adl2 carcinogenesis to activation of endogenous virus particles, and also the correlation between Adl2 carcinogenesis and cancer related genes. Acta Pathol Jpn 42: 242-248, 1992.  相似文献   
56.
57.
Eighty-five young Mauritian Indians, male survivors of premature myocardial infarction (MI) and thus belonging to a high risk group, were compared with 108 stringently selected controls for a possible association between premature MI and an insertion/deletion (I/D) polymorphism in the gene encoding angiotensin I-converting enzyme (ACE). The frequency of the D allele was 0.42 in the MI group and 0.43 in the control group, and thus no association between I/D polymorphism of ACE with susceptibility to early-onset MI was found in this population group. Other gene components of the renin-angiotensin system and lipid metabolism need to be explored to understand the genetic factors involved in causing MI at an early age.  相似文献   
58.
Summary We have studied the structure of the two linear DNA plasmids, kl and k2, present in killer strains of Kluyveromyces lactis. Two killer strains of different origins, CBS 2359 and IFO 1267 were examined. For both strains, identical restriction maps of kl and k2 DNA were obtained. Several restriction sites previously reported for the kl DNA of the strain IFO 1267 have been confirmed. The molecular weights of these double-stranded DNAs were 8.8 kilobase pairs for kl and 13.4 for k2, as determined by electrophoresis of restriction fragments. The plasmid DNA from a nonkiller mutant, NK2/1, was also examined. In this mutant, the kl DNA was replaced by a smaller DNA (5.9 kilobase pairs), the k2 DNA being normal. Restriction enzyme analysis showed that the new plasmid DNA was also linear. Hybridization experiments demonstrated that it was derived from the kl DNA by deletion of a 2.9 kilobase pair segment from the central part of the kl DNA. The deleted segment carries a gene involved in toxin production, but is not related to immunity since the mutant is resistant to killers. The plasmid DNA of K. lactis showed no detectable sequence homology with the double stranded RNA of the killer system of Saccharomyces cerevisiae. Neither was any homology found with nuclear and mitochondria) DNA.  相似文献   
59.
Summary Chloroplast DNA was isolated from total cellular DNA of a bleached mutant of Euglena gracilis (Y3BUD) by enrichment of the light component (p = 1.686) by repeated CsCl equilibrium centrifugations. Electron microscope visualization of this DNA showed minicircular DNA molecules in addition to large circular molecules (42 pm) identical to wild type chloroplast DNA. They were heterogenous in size and their contour lengths ranged from 0.8 to 8.5 m. Fractionnation by agarose gel electrophoresis gave several discrete bands. Some of them hybridized with pure chloroplast DNA and with several cloned chloroplast DNA fragments, particularly to ribosomal fragments, while others did not show homology with chloroplast DNA being probably of extrachloroplatic origin.  相似文献   
60.
Telomere structure, function and maintenance in Arabidopsis   总被引:5,自引:0,他引:5  
The stability of eukaryotic genomes is provided in part by the integrity of telomeres, the nucleoprotein caps on the ends of chromosome. Recent studies reveal that proper telomere architecture is required for long-term proliferation capacity. Here we describe molecular mechanisms that protect and maintain chromosome ends and discuss why Arabidopsis is emerging as a powerful new model for elucidating fundamental aspects of telomere biology.  相似文献   
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