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排序方式: 共有288条查询结果,搜索用时 15 毫秒
1.
Several different lines of evidence have demonstrated that inherited susceptibility to rheumatoid arthritis (RA) is associated with the DRB1 genes encoding the HLA-DR4 and HLA-DR1 molecules. A contrasting hypothesis has recently been proposed, suggesting that, in general, the DRB1 locus is associated with protection to RA and that the RA-associated DRB1 alleles are not responsible for the primary disease association but merely permissive for the susceptibility conferred by the HLA-DQ alleles with which they are in linkage disequilibrium. We have performed a critical review of the literature on the HLA association in RA with special emphasis on studies in which both an HLA-DR and -DQ association has been investigated. Our analyses provide strong evidence against the hypothesis that HLA-DQ molecules play a major role in the general susceptibility to RA. Thus, the strongest association in rheumatoid arthritis is with DRB1 genes rather than DQB1 genes. 相似文献
2.
Steenbergen EJ; Verhagen OJ; van Leeuwen EF; van den Berg H; von dem Borne AE; van der Schoot CE 《Blood》1995,86(2):692-702
Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL. 相似文献
3.
Fugger EF; Black SH; Keyvanfar K; Schulman JD 《Human reproduction (Oxford, England)》1998,13(9):2367-2370
The world's first deliveries of normal babies after use of flow cytometric
separated human sperm cells (MicroSort) for preconception gender selection
are reported. Offspring were of the desired female gender in 92.9% of the
pregnancies. Most of these pregnancies and births were achieved after
simple intrauterine insemination.
相似文献
4.
Detecting pre-ovulatory luteinizing hormone surges in urine 总被引:2,自引:1,他引:2
Kesner JS; Knecht EA; Krieg EF Jr; Wilcox AJ; O'Connor JF 《Human reproduction (Oxford, England)》1998,13(1):15-21
The study objectives were to determine (i) if pre-ovulatory luteinizing
hormone (LH) surges, undetected in urine by two immunoradiometric assays
(IRMA), were detectable by an ultrasensitive immunofluorometric assay
(IFMA) and (ii) the influence of creatinine adjustment on the detection and
timing of the urinary LH surges. Daily urine specimens were contributed by
healthy 25-36 year old volunteers during 14 ovulatory menstrual cycles for
an epidemiological study conducted in 1983-1985. Specimens were selected as
having been previously assayed by two IRMA without consistently detecting
LH surges. These urine specimens were remeasured using an IFMA and adjusted
for creatinine concentration. IFMA measurements revealed unambiguous LH
surges in all cycles. Adjusting IRMA urinary LH values for creatinine
concentrations revealed previously undetected LH surges in four of eight
cycles. Creatinine adjustment also altered the timing of IRMA and IFMA LH
surges by 1-5 days. These results demonstrate an IFMA that detects pre-
ovulatory LH surges in unpreserved, frozen urine from cycles where such
surges were previously undetectable. Further, creatinine adjustment can
markedly affect detection and timing of the onset and peak of the urinary
LH surge. While our analysis suggests that this adjustment improves the
validity of the LH measure, this requires further investigation.
相似文献
5.
María Jesús Fernández Aceñero MD PhD Cristina Díaz del Arco CDdA MD Carme Dinarés CD MD PhD Tania Labiano TL MD Eva Tejerina ET MD PhD Mª José Bernabé MJ B MD Elena Forcen EF MD Melchor Saiz-Pardo MSP MD Pablo Pérez PP MD Maria D. Lozano MDL MD PhD 《Diagnostic cytopathology》2023,51(1):26-35
Lung carcinoma remains one of the most frequent and aggressive human neoplasms. Fortunately, in the last decades, the increasing knowledge of the molecular mechanisms leading to cancer development has allowed the use of targeted therapies with improvement of prognosis in many patients. Clinical management has also changed after the introduction of endobronchialultrasonographic bronchoscopy that allows a conservative staging of lung tumors, avoiding the need of mediastinoscopy for lymph node staging. Lung pathologists and cytopathologists are facing the challenge of giving the more comprehensive prognostic and predictive information with ever smaller tissue or cytological samples. The aim of this review is to summarize the molecular testing for non-small cell lung carcinoma and how pathologists can contribute to the patient's outcome with a conscious management of biological samples. 相似文献
6.
Vidal F Blanco J Fugger EF Keyvanfar K Norton M Schulman JD Egozcue J 《Human reproduction (Oxford, England)》1999,14(12):2987-2990
Using triple colour fluorescent in-situ hybridization (FISH) we have evaluated, on a blind basis, the disomy level for chromosome 21 and the sex chromosomes in flow cytometric sorted sperm samples. There were no statistically significant differences in the disomy rates when comparing the sorted samples (either for X- or Y-bearing spermatozoa) with non-sorted samples. There were no diploid spermatozoa observed in any sample group after MicroSort processing. 相似文献
7.
8.
松花粉和松针提取物在亲脂性体外模型系统中抗氧化能力和机制的研究 总被引:3,自引:0,他引:3
目的:对松花粉和松针提取物在亲脂性抗氧化模型系统中的抗氧化能力和机制进行研究。方法:采用铜诱导的LDL氧化反应模型和Rose Bengal反应模型分别进行评价。结果:松花粉乙醇提取液具有较好的自由基链式反应阻断剂的作用,有效地推迟人血浆中低密度脂蛋白(LDL)氧化生成共轭二烯。松针乙醇提取液对LDL的保护作用优于松花粉。在Rose Bengal系统中,松花粉以清除自由基和螯合铜的两种机制抑制脂质过氧化反应的发生,而松针主要作为自由基清除剂发挥抗氧化作用。结论:松花粉和松针在两个亲脂性体外模型中均发挥很好的抗氧化能力,而抗氧化机制不尽相同。 相似文献
9.
Deformable sickle erythrocytes have been reported by Mohandas and Evans to be more adherent to vascular endothelium than rigid irreversibly sickled cells (ISC). To define the clinical implications of this finding we have determined genetic, hematological, clinical, and rheological characteristics of sickle erythrocytes obtained from 65 patients with sickle cell anemia and fetal hemoglobin (Hb F) levels less than 15%. The alpha-globin gene number had a significant effect on the hematological parameters, the percentage of dense cells, ISC number, and HB A2 levels. The presence or absence of alpha thalassemia, however, had no effect on the frequency and severity of the sickle cell painful crisis (r = 0.06, P greater than .05). RBC deformability, determined by an ektacytometer, showed great heterogeneity among patients with three or four alpha-globin genes. Linear regression analyses of the data showed significant positive correlation of the frequency and severity of the painful crisis with RBC deformability (r = 0.49, P less than .001), and negative correlations with the percentage of dense cells (r = -0.37, P = .002), and the percentage of ISC (r = -0.46, P less than .001). We propose that the more deformable the sickle RBC are, the greater their adherence to vascular endothelium, and the more they cause vaso-occlusive crises, RBC deformability and the percentage of dense cells (or ISC) seem to have a predictive value of the frequency and severity of painful crises in sickle cell anemia. 相似文献
10.
Thrombospondin mediates the cytoadherence of Plasmodium falciparum- infected red cells to vascular endothelium in shear flow conditions 总被引:3,自引:0,他引:3
Rock EP; Roth EF Jr; Rojas-Corona RR; Sherwood JA; Nagel RL; Howard RJ; Kaul DK 《Blood》1988,71(1):71-75
Cerebral malaria is thought to involve specific attachment of Plasmodium falciparum-infected knobby red cells to venular endothelium. The nature of surface ligands on host endothelial cells that may mediate cytoadherence is poorly understood. We have investigated the effects of soluble thrombospondin, rabbit antiserum raised against thrombospondin, and human immune serum on cytoadherence of parasitized erythrocytes in ex vivo mesocecum vasculature. Preincubation of infected red cells with soluble thrombospondin or human immune serum inhibits binding of infected red cells to rat venular endothelium. Infusion of the microcirculatory preparation with rabbit antithrombospondin antibodies before perfusion of parasitized erythrocytes also resulted in decreased cytoadherence. In addition, incubation of infected cells with human immune sera obtained from malaria patients significantly inhibited the observed cytoadherence. Our results indicate that thrombospondin mediates binding of infected red cells to venular endothelium and may thus be involved in the pathogenesis of cerebral malaria. 相似文献