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11.
12.
Targeted gene disruption of murine CD7 总被引:2,自引:0,他引:2
CD7 is a 40 kDa type I transmembrane glycoprotein member of the Ig
superfamily. CD7 is a marker of mature human T cells and NK cells, and is
expressed early in their development. Cross-linking CD7 positively
modulates T cell and NK cell activity as measured by calcium fluxes,
expression of adhesion molecules, cytokine secretion and proliferation. CD7
associates directly with phosphoinositol 3'-kinase, and CD7 ligation
induces production of D-3 phosphoinositides and tyrosine phosphorylation.
Severe combined immunodeficiency has been associated with a lack of
lymphocyte surface CD7. The CD7 ligand is unknown. The murine CD7 homolog
is encoded by a single gene on chromosome 11. In order to characterize the
role of CD7 in lymphocyte development and function we have eliminated the
CD7 gene by targeted disruption. CD7- deficient mice display normal
histology of thymus and spleen, normal lymphocyte populations in primary
and secondary lymphoid tissues, and normal serum Ig levels. Specific
antibody responses after immunization with T-dependent and T-independent
antigens are equivalent in wild-type and CD7 knockout mice. CD7-deficient
lymphocytes respond normally to T cell mitogenic and allogeneic stimuli,
and display normal NK cell cytotoxicity.
相似文献
13.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
14.
Genotyping and coalescent phylogenetic analysis of Pneumocystis jiroveci from South Africa 总被引:3,自引:0,他引:3
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Sequence analysis of Pneumocystis jiroveci internal transcribed spacer (ITS) regions has become an important epidemiological tool. The objectives of the present study were to investigate sequence variations in the ITS1-5.8S ribosomal DNA (rDNA)-ITS2 regions; determine the P. jiroveci genotypes present in Cape Town, South Africa; and resolve the lineage evolution of the types by use of the coalescent theory. ITS regions were amplified from samples collected from 19 patients. PCR products were cloned, and four to five clones were sequenced from each specimen. Statistical parsimony was applied for coalescence-based network genotype analysis. The most prevalent type was Eg (14 of 19 patients, 33 of 83 clones), followed by Gg (4 of 19 patients, 7 of 83 clones), Eu (3 of 19 patients, 5 of 83 clones), and Gh (2 of 19 patients, 2 of 83 clones). Four new combinations (Eo, Je, Ge, and No), 11 new ITS1 sequences, and 13 new ITS2 sequences were identified. A new ITS2 type was detected in three patients and was designated type u. Coinfection appeared to be common, with 15 of 19 patients harboring more than one type and with up to six types per specimen. The resultant parsimony network identified Eg as the most probable ancestral haplotype and supported the occurrence of recombinational events within the population studied. Although the 5.8S rDNA region revealed only 13 clones containing one to two nucleotide polymorphisms, it may assist in defining types. Coalescent theory proposed that Eg is an ancestral type from which microevolutionary subtypes radiate. 相似文献
15.
Dou Q; Tarnuzzer RW; Williams RS; Schultz GS; Chegini N 《Molecular human reproduction》1997,3(11):1005-1014
16.
Needle biopsy of renal allografts: comparison of two techniques 总被引:2,自引:0,他引:2
Bogan ML; Kopecky KK; Kraft JL; Holladay AO; Filo RS; Leapman SB; Thomalla JV 《Radiology》1990,174(1):273-275
Two techniques for renal allograft biopsy were retrospectively evaluated to compare relative safety and efficacy. After ultrasound (US) localization of the kidney and biopsy with a hand-held 14-gauge cutting needle, an adequate specimen was obtained in 74 of 77 cases (96%). Major complications occurred in six of these 77 cases (8%). One hundred four biopsies were performed by using a smaller 18-gauge cutting needle with a spring-loaded biopsy "gun" and real-time US guidance. With this newer technique, specimens adequate for diagnosis were obtained in 99 biopsies (95%). There was a single major complication with this technique (1%). The 18-gauge needle with real-time US guidance yields comparably adequate specimens with a lower frequency of complications. 相似文献
17.
18.
Schechter DS Marshall R Salmán E Goetz D Davies S Liebowitz MR 《Journal of traumatic stress》2000,13(3):529-534
Objective: Ataque de nervios is a common, self-labeled Hispanic folk diagnosis. It typically describes episodic, dramatic outbursts of negative emotion in response to a stressor, sometimes involving destructive behavior. Dissociation and affective dysregulation during such episodes suggested a link to childhood trauma. We therefore assessed psychiatric diagnoses, history of ataque, and childhood trauma in treatment-seeking Hispanic outpatients (N = 70). Significantly more subjects with an anxiety or affective disorder plus ataque reported a history of physical abuse, sexual abuse, and/or or a substance-abusing caretaker than those with psychiatric disorder but no ataque. In some Hispanic individuals, ataque may represent a culturally sanctioned expression of extreme affect dysregulation associated with childhood trauma. Patients with ataque de nervios should receive a thorough traumatic history assessment. 相似文献
19.
MJ Stevens PD Stricker J Saalfeld PC Brenner R Kooner GFA O'Neill PJ Duval RS Jagavkar P Cross J Martland 《Journal of Medical Imaging and Radiation Oncology》2003,47(2):152-160
Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate‐ and high‐risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate‐specific antigen progression‐free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability. 相似文献
20.
几种中西药抗人实验模拟运动病效果观察 总被引:1,自引:0,他引:1
目的 :选用中药“治晕灵”的主要成分生姜、明天麻等六味草药煎成汤剂、或半量汤剂配西药脑益嗪、山莨菪碱各1 4临床常用量配成复方中西药制剂 ,与目前常用抗晕药晕海宁等中、西药的药效进行比较 ,看中药制剂或中西药复方制剂是否具有较好的抗运动病效果。方法 :选 7名敏感被试者 (女性 ,19~ 2 1岁 ) ,用旋转刺激诱发运动病至出现恶心。按拉丁方设计 ,与安慰剂 (淀粉 10 0mg)及晕海宁 (5 0mg)进行对比 ,分别观察了生姜合剂 (30ml)、晕可平 (30ml)、山莨菪碱 (10mg)、脑益嗪 (2 5mg)及上述复方中西药制剂口服后的运动病耐力。结果 :与安慰剂比较 ,晕海宁、山莨菪碱、脑益嗪、晕可平、生姜合剂、复方中西药制剂分别使运动病耐力提高 5 .4%、7.5 %、5 .9%、7.4%、32 .3 %、2 0 .4% ;生姜合剂效果较优 ,除口服时有辛辣味外 ,无明显的副作用。复方中西药制剂各成分未显示协同作用 ,而只是简单的作用相加。结论 :生姜合剂具有较好的抗运动病作用 相似文献