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71.
New alleles in the B44 family including B*44022, B*44032, B*4411, B*4420, B*4421, B*4424, and B*8301
Steiner NK Gans CP Kosman C Bradshaw D Koester R Menchaca EM Mitton W Ng J Hartzman RJ Hurley CK 《Tissue antigens》2001,57(4):376-379
Seven new HLA-B locus alleles have been described. B*44022 and B*44032 are silent substitutions altering known alleles. B*4411 carries a unique Bw4-like epitope. B*4420, B*4421, and B*4424 carry new combinations of motifs previously observed in other alleles. B*8301 appears to be the result of the replacement of exon 2 from B*4402 with exon 2 from B*5603. 相似文献
72.
Evaluation of a Selective Transport Medium for Gastric Biopsy Specimens To Be Cultured for Helicobacter pylori 总被引:1,自引:0,他引:1 下载免费PDF全文
L. K. Siu W. K. Leung A. F. B. Cheng J. Y. Sung T. K. W. Ling J. M. L. Ling E. K. W. Ng J. Y. W. Lau S. C. S. Chung 《Journal of clinical microbiology》1998,36(10):3048-3050
Since the means of culturing Helicobacter pylori may not be available in some laboratories, prolonging the survival of this organism during transportation is a major concern in terms of improving detection rates. A selective transport medium was evaluated for the preservation of H. pylori from 254 gastric biopsy specimens collected from a rural area in China where culturing is not feasible. Gastric biopsy specimens were inoculated in sterile broth consisting of brain heart infusion (BHI) broth, horse serum, and yeast extract supplemented with vancomycin, amphotericin B, and nalidixic acid (VAN). Of the 254 biopsy specimens, 238 were identified by histology to have H. pylori infection. Total rates of recovery of H. pylori from the H. pylori-positive gastric biopsy specimens stored in the BHI-VAN broth ranged from 76 to 46% after storage of specimens for 5 to 9 days. In conclusion, the selective medium is useful for prolonging the survival of H. pylori in gastric biopsy specimens for which immediate culture is not feasible. 相似文献
73.
An immunohistochemical study of neuronal and glial cell reactions in retinae of rats with experimental glaucoma 总被引:5,自引:0,他引:5
Wang X Tay SS Ng YK 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2000,132(4):476-484
Glaucoma is a common disease seen in the eye clinic, but its associated pathological processes, especially the role of glial cells in glaucomatous retinae, are still under debate. The aim of the present work was to study the responses of astrocytes, Müller cells and microglia in retinae of rats with experimental glaucoma. Glaucoma was induced in adult male Wistar rats by cauterizing limbal-derived veins and the changes in glial fibrillary acidic protein (GFAP), OX42, OX18, OX6 and EDI expression were studied by immunohistochemical staining. Neuronal cell viability was studied by immunostaining with the neuronal nuclei (NeuN) antibody. In the experimental glaucomatous eyes, a significant drop in the number of NeuN-positive neurons was observed from 7 days postoperation and beyond in both the ganglion cell layer and inner nuclear layer. The expression of GFAP and OX42 was increased during the first 2 months after operation and reduced in rats at 3 and 4 months. OX6 and OX18 immunoreactivity was induced in some microglia of both glaucomatous and sham-operated control eyes. Possible mechanisms of the reaction of astrocytes, Müller cells and microglia in neuronal degeneration following glaucoma are discussed. 相似文献
74.
Biparental Phodopus campbelli and uniparental P. sungorus juvenile litters (2 males, 2 females) both consumed amniotic fluid and placenta during the birth of younger siblings. Three days later, P. campbelli juveniles were most responsive to a displaced younger sibling. Thus, P. campbelli are responsive to pups as juvenile alloparents and as new parents; however, at intervening ages, infanticidal attack (bite) was seen. At 5, 7, 9, 11, or 13 weeks of age, male and female P. campbelli were given a 5-min test with an unrelated, 3-day-old, anesthetized pup. Females attacked more often than males, yet pup-retrieval rates did not differ. Female aggression increased with age and was replaced by retrieval behavior 3 days after parturition. Male attack ceased after a birth, but parental behavior did not increase, remaining below the rate for new fathers tested with their own awake pup. Over repeated testing, behavior in one test did not predict behavior in another. Transitions from caregiving alloparent to infanticidal adult and back to parental care were clear in females, but less discrete with this stimulus paradigm in these highly paternal males. 相似文献
75.
Reactive hemophagocytic syndrome is a clinico-pathologic entity characterized by systemic proliferation of non-neoplastic histiocytes showing phagocytosis of hemopoietic cells, resulting in blood cytopenia. It is best known to be associated with virus infection, but other associated diseases have also been implicated. The clinical and pathological findings of 7 fatal cases are described. The syndrome affected both sexes of a wide age range, and all patients had fever. Significant laboratory findings were blood cytopenia, abrupt drop in the blood cell counts, deranged liver function tests and abnormal coagulation profile. The associated diseases were diverse: two patients had bacterial infection; two had peripheral T-cell lymphoma; one had disseminated undifferentiated carcinoma of the ovary; one had both tuberculosis and disseminated nasopharyngeal carcinoma, and one had no obvious underlying disease. It is postulated that lymphokines secreted by lymphoid cells or tumor cells may be responsible for the systemic activation of histiocytes. The differential diagnosis from malignant histiocytosis is discussed. 相似文献
76.
Recombinant alpha2(IV)NC1 domain inhibits tumor cell-extracellular matrix interactions, induces cellular senescence, and inhibits tumor growth in vivo 下载免费PDF全文
Roth JM Akalu A Zelmanovich A Policarpio D Ng B MacDonald S Formenti S Liebes L Brooks PC 《The American journal of pathology》2005,166(3):901-911
Cellular interaction with the extracellular matrix is thought to be a critical event in controlling angiogenesis and tumor growth. In our previous studies, genetically distinct noncollagenous (NC) domains of type-IV collagen were shown to interact with integrin receptors expressed on the surface of endothelial cells. Moreover, these NC1 domains were shown to inhibit angiogenesis in vivo. Here, we provide evidence that a recombinant form of the alpha2(IV)NC1 domain of type-IV collagen could bind integrins alpha1beta1 and alphavbeta3 expressed on melanoma cells and inhibit tumor cell adhesion in a ligand-specific manner. Systemic administration of recombinant alpha2(IV)NC1 domain potently inhibited M21 melanoma tumor growth within full thickness human skin and exhibited a dose-dependent inhibition of tumor growth in nude mice. Interestingly, alpha2(IV)NC1 domain enhanced cellular senescence in tumor cells in vitro and in vivo. Taken together, these results suggest that recombinant alpha2(IV)NC1 domain is not only a potent anti-angiogenic reagent, but it also directly impacts tumor cell behavior. Thus, alpha2(IV)NC1 domain represents a potent inhibitor of tumor growth by impacting both endothelial and tumor cell compartments. 相似文献
77.
Quantitative and cost comparison of ultrasensitive human immunodeficiency virus type 1 RNA viral load assays: Bayer bDNA quantiplex versions 3.0 and 2.0 and Roche PCR Amplicor monitor version 1.5 下载免费PDF全文
Elbeik T Charlebois E Nassos P Kahn J Hecht FM Yajko D Ng V Hadley K 《Journal of clinical microbiology》2000,38(3):1113-1120
Quantification of human immunodeficiency virus type 1 (HIV-1) RNA as a measure of viral load has greatly improved the monitoring of therapies for infected individuals. With the significant reductions in viral load now observed in individuals treated with highly active anti-retroviral therapy (HAART), viral load assays have been adapted to achieve greater sensitivity. Two commercially available ultrasensitive assays, the Bayer Quantiplex HIV-1 bDNA version 3.0 (bDNA 3.0) assay and the Roche Amplicor HIV-1 Monitor Ultrasensitive version 1.5 (Amplicor 1.5) assay, are now being used to monitor HIV-1-infected individuals. Both of these ultrasensitive assays have a reported lower limit of 50 HIV-1 RNA copies/ml and were developed from corresponding older generation assays with lower limits of 400 to 500 copies/ml. However, the comparability of viral load data generated by these ultrasensitive assays and the relative costs of labor, disposables, and biohazardous wastes were not determined in most cases. In this study, we used matched clinical plasma samples to compare the quantification of the newer bDNA 3.0 assay with that of the older bDNA 2.0 assay and to compare the quantification and costs of the bDNA 3.0 assay and the Amplicor 1.5 assay. We found that quantification by the bDNA 3.0 assay was approximately twofold higher than that by the bDNA 2.0 assay and was highly correlated to that by the Amplicor 1.5 assay. Moreover, cost analysis based on labor, disposables, and biohazardous wastes showed significant savings with the bDNA 3.0 assay as compared to the costs of the Amplicor 1.5 assay. 相似文献
78.
Susceptibility of thymectomized and irradiated mice to challenge with several organisms and the effect of dapsone on infection with Mycobacterium leprae. 总被引:1,自引:4,他引:1 下载免费PDF全文
B6C3F1 mice that had been thymectomized at 8 to 12 weeks of age, subjected to 950 R of whole-body X irradiation, and transfused with syngeneic bone marrow were challenged in a footpad with Mycobacterium leprae or M. marinum, or intravenously or intraperitioneally with Listeria monocytogenes. Also, mice inoculated with M. leprae in a hind footpad were administered dapsone in the mouse chow. The thymectomized-irradiated (T + R) mice did not survive as well as non-thymectomized mice when housed in the vivarium with no special precautions, but survived sufficiently well to permit the completion of some long-term experiments. M. leprae multiplied to a higher "ceiling" and survived longer in the T + R mice than in the non-thymectomized controls. But a ceiling to multiplication of M. leprae was imposed, and finally the organisms were killed. The histopathological appearance of the footpad tissues, studied by electron microscopy, was consistent with the measurements of bacterial numbers and viability. Swelling of the footpad after local inoculation with M. marinum was greater in T + R mice than in non-thymectomized controls. Similarly, the number of L. monocytogenes following intravenous challenge was greater in the spleens of T + R than of non-thymectomized mice, and the survival of the T + R mice was impaired after intraperitoneal challenge with L.monocytogenes, compared to the survival of non-thymectomized mice. None of these differences was striking, suggesting that these T + R mice had retained or regained some immune competence. The effects of dapsone treatment of T + R mice inoculated with M. leprae were much the same as those of treatment of non-thymectomized mice. Because these T + R mice were not greatly immunosuppressed, they would not have provided a model of human lepromatous leprosy suitable for chemotherapeutic studies. 相似文献
79.
Lysine methylation within the globular domain of histone H3 by Dot1 is important for telomeric silencing and Sir protein association 总被引:17,自引:0,他引:17
Ng HH Feng Q Wang H Erdjument-Bromage H Tempst P Zhang Y Struhl K 《Genes & development》2002,16(12):1518-1527
The amino-terminal histone tails are subject to covalent post-translational modifications such as acetylation, methylation, and phosphorylation. In the histone code hypothesis, these exposed and unstructured histone tails are accessible to a repertoire of regulatory factors that specifically recognize the various modified histones, thereby generating altered chromatin structures that mediate specific biological responses. Here, we report that lysine (Lys) 79 of histone H3, which resides in the globular domain, is methylated in eukaryotic organisms. In the yeast Saccharomyces cerevisiae, Lys 79 of histone H3 is methylated by Dot1, a protein shown previously to play a role in telomeric silencing. Mutations of Lys 79 of histone H3 and mutations that abolish the catalytic activity of Dot1 impair telomeric silencing, suggesting that Dot1 mediates telomeric silencing largely through methylation of Lys 79. This defect in telomeric silencing might reflect an interaction between Sir proteins and Lys 79, because dot1 and Lys 79 mutations weaken the interaction of Sir2 and Sir3 with the telomeric region in vivo. Our results indicate that histone modifications in the core globular domain have important biological functions. 相似文献
80.
Understanding the adaptation of Halobacterium species NRC-1 to its extreme environment through computational analysis of its genome sequence 总被引:8,自引:0,他引:8
The genome of the halophilic archaeon Halobacterium sp. NRC-1 and predicted proteome have been analyzed by computational methods and reveal characteristics relevant to life in an extreme environment distinguished by hypersalinity and high solar radiation: (1) The proteome is highly acidic, with a median pI of 4.9 and mostly lacking basic proteins. This characteristic correlates with high surface negative charge, determined through homology modeling, as the major adaptive mechanism of halophilic proteins to function in nearly saturating salinity. (2) Codon usage displays the expected GC bias in the wobble position and is consistent with a highly acidic proteome. (3) Distinct genomic domains of NRC-1 with bacterial character are apparent by whole proteome BLAST analysis, including two gene clusters coding for a bacterial-type aerobic respiratory chain. This result indicates that the capacity of halophiles for aerobic respiration may have been acquired through lateral gene transfer. (4) Two regions of the large chromosome were found with relatively lower GC composition and overrepresentation of IS elements, similar to the minichromosomes. These IS-element-rich regions of the genome may serve to exchange DNA between the three replicons and promote genome evolution. (5) GC-skew analysis showed evidence for the existence of two replication origins in the large chromosome. This finding and the occurrence of multiple chromosomes indicate a dynamic genome organization with eukaryotic character. 相似文献