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101.
The functional of B-L (Ia-equivalent)-positive (B-L+) adn -negative (B-L-) chicken peripheral blood lymphocytes (PBL) was studied in vitro and in vivo. The PBL were first stained in direct immunofluorescence tests with a fluorescein isothiocyanate-labelled anti-B-L alloantiserum and then separated by means of a fluorescence-activated cell sorter. In agreement with our previous findings, B-L- cells showed functional properties of T lymphocytes, responding to concanavalin A and phytohaemagglutinin-P in vitro and inducing a graft-versus-host (GVH) reaction when injected into allogeneic embryos. Sorted B-L+ gave no responses in any of these assays. Neither B-L+ nor B-L- cells, when tested alone, responded significantly to pokeweed mitogen, but mixtures of the two restored the responsiveness to that of the original unsorted suspension. Of the B-L+ PBL, 10% were T cells, which may account for the low GVH reactivity given by this population. 相似文献
102.
Risk of localized and widespread endometrial cancer in relation to recent and discontinued use of conjugated estrogens 总被引:13,自引:0,他引:13
S Shapiro J P Kelly L Rosenberg D W Kaufman S P Helmrich N B Rosenshein J L Lewis R C Knapp P D Stolley D Schottenfeld 《The New England journal of medicine》1985,313(16):969-972
In a case-control study of the risk of adenocarcinoma of the endometrium in relation to conjugated-estrogen use, we found that 31 per cent of 425 women with endometrial cancer and 15 per cent of 792 controls reported having used conjugated estrogens; the rate-ratio estimate was 3.5 with a 95 per cent confidence interval of 2.6 to 4.7. For use that lasted at least one year, the rate-ratio estimate for Stage I or II cancer was 5.2 (95 per cent confidence interval, 3.7 to 7.2), and for Stages III and IV combined it was 3.1 (1.5 to 6.4). Among women who had used estrogen for at least one year and then discontinued it, the risk of endometrial cancer remained significantly elevated even after estrogen-free intervals of over 10 years. The findings suggest that long-term use of conjugated estrogen increases the risk of both localized and widespread endometrial cancer. The data also suggest that women who have taken conjugated estrogen for one or more years remain at increased risk for at least 10 years after they discontinue use. Such women should be considered for long-term gynecologic surveillance. 相似文献
103.
bcl-2 transgene expression promotes survival and reduces proliferation of CD3-CD4-CD8- T cell progenitors 总被引:16,自引:0,他引:16
Proliferative expansion and apoptotic cell death play prominent roles in T
cell development. The molecular control of cell cycle progression and
apoptosis appear to be inter-connected since the Bcl-2 protein can inhibit
apoptosis and slow cell cycle progression in cortical thymocytes and mature
T cells, particularly during the transition from the quiescent state into
the cell cycle. Here the impact of bcl-2 transgene expression on
CD3-CD4-CD8- T cell progenitors was assessed. Bcl-2 enhanced the survival
of these progenitors at all of the four major differentiation stages, CD25-
CD44+ (pro-T1), CD25 + CD44+ (pro- T2), CD25 + CD44- (pro-T3) and
CD25-CD44- (pro-T4). However, it reduced cell cycling and slowed turnover
only in the pro-T4 subset. From an analysis of bcl-2 transgenic mice
expressing a TCR transgene or bearing a mutation in the scid or rag-1 gene
we conclude that Bcl-2 inhibits proliferation only of T cell progenitors
that are activated via the pre- TCR, not those stimulated via c-Kit and the
IL-7 receptor.
相似文献
104.
Roudebush WE Wininger JD Jones AE Wright G Toledo AA Kort HI Massey JB Shapiro DB 《Human reproduction (Oxford, England)》2002,17(5):1306-1310
BACKGROUND: A definitive need exists to identify a biomarker of embryonic viability. Platelet-activating factor (PAF) production by human embryos is related to pregnancy potential. METHODS: Conditioned embryo culture media were obtained following conventional IVF on day 3, with PAF levels and pregnancy outcomes correlated. RESULTS: Overall pregnancy rate was 68% (17/25) with a mean of 84.1 (+/- 8.5) pmol/l/embryo PAF level. PAF levels ranged from a 216.4 pmol/l/embryo (pregnant) to a 3.7 pmol/l/embryo (not pregnant). There was a significant difference (P < 0.05) in PAF content between pregnant (92.1 +/- 9.5 pmol/l/embryo) and non-pregnant groups (52.5 +/- 16.6 pmol/l/embryo). Patients were categorized into three groups based upon PAF levels: low (< or= 5 pmol/l/embryo); medium (51-100 pmol/l/embryo) and high (>100 pmol/l/embryo). The low (60%) group had a significantly (P < 0.05) lower pregnancy rate than either the medium (85%) or high (89%) groups. A receiver-operator characteristic curve predicted a cut-off limit of 45 pmol/l/embryo for PAF content in human embryo conditioned culture media. CONCLUSIONS: The data demonstrate a correlation between PAF levels in human embryo conditioned culture media and pregnancy outcome. Additionally, as embryonic PAF levels increase so does the corresponding pregnancy rate. Therefore, PAF may be used as an indicator of embryo viability and for predicting pregnancy outcome. 相似文献
105.
106.
JUAN C. DE LA TORRE MARGARET MALLORY MICHELLE BROT LISA GOLD GEORGE KOOB MICHAEL B. A. OLDSTONE ELIEZER MASLIAH 《Virology》1996,220(2):508
Neurons have a restricted expression of MHC heavy chain molecules which prevents presentation of antigens of infecting viruses. As a result, such infected cells escape immune surveillance and allow the establishment of noncytolytic persistent infection. Here we show that a chronic noncytolytic viral infection bothin vitroandin vivoselectively perturbed the expression of GAP-43, a protein that plays a central role in neuronal plasticity processes accompanying learning and memory. GAP-43 expression was greatly decreased in the hippocampus, an area of heightened viral replication, while synaptic density was preserved. Concurrently, the ability to learn tasks was significantly impaired in these persistently infected mice. Yet, infected neurons remained free from structural injury. 相似文献
107.
The possibility of a hypothalamo-pituitary involvement in the intracranial self-stimulation phenomenon was investigated. Threshold and optimal stimulation currents were identified by means of the method of limits, in rats with bipolar electrodes implanted in the lateral hypothalamus. Total or sham hypophysectomies were performed after the establishment of these current values, and found to have no effect on reinforcing brain stimulation. It was concluded that a hypothalamo-pituitary mechanism does not subserve reinforcing brain stimulation. 相似文献
108.
NMDA receptor antagonists impair memory for nonspatial,socially transmitted food preference 总被引:3,自引:0,他引:3
Rats avoid unfamiliar foods and learn to prefer those that they smell on the breath of conspecifics. Hippocampal lesions produce rapid forgetting of this socially acquired memory. The authors report that NMDA receptor antagonists impair this memory. Rats given CPP were trained in the social transmission of food preference task. Normal rats showed robust memory 72 hr later. CPP-injected rats performed normally 24 hr, but randomly 72 hr, after training. Spatial context was irrelevant: Rats trained and tested in different rooms performed the same as rats trained and tested in 1 room. MK801 and intrahippocampal injections of APV produced amnestic effects similar to CPP. Thus, NMDA receptor activation is crucial for the persistence of socially acquired, hippocampus-dependent, nonspatial memory. 相似文献
109.
Stein MD Cunningham WE Nakazono T Asch S Turner BJ Crystal S Andersen RM Zierler S Bozzette SA Shapiro MF 《Journal of acquired immune deficiency syndromes (1999)》2000,25(1):51-55
OBJECTIVE: Gynecologic disease is common in HIV-infected women. We examine the sociodemographic, clinical, and provider factors associated with the care of women with vaginal symptoms. METHODS: Women enrolled in the HIV Cost and Services Utilization Study (HCSUS), a nationally representative probability sample of HIV-infected adults, were interviewed between January 1996 and April 1997. Women with vaginal symptoms who sought medical attention were asked, "Did your health care provider examine your vaginal area?" Women were also asked if they received medication for their symptoms. RESULTS: Among 154 women with vaginal symptoms, 127 sought care for their symptoms. Of those who sought care, 48% saw a gynecologist and 52% sought care from nongynecologists, most often their usual HIV care provider. Women who saw a gynecologist for their symptoms were more likely to have received a pelvic examination (92% versus 76%; p =.06) and vaginal fluid collection (98% versus 88%; p =.06) than those who saw their regular HIV provider. Fifteen percent of women received medication for their symptoms without having a pelvic examination; gynecologists were less likely to prescribe without an examination (8% versus 21%; p =.12). CONCLUSION: Gynecologists are more likely to provide adequate care of vaginal symptoms among HIV-infected women than nongynecologists who were HIV care providers. This specialty difference is consistent with quality of care studies for other medical conditions, but the potential gynecologic complications of inadequate evaluation and treatment warrants further investigation. 相似文献
110.
High throughput parallel analysis of hundreds of patient samples for more than 100 mutations in multiple disease genes 总被引:5,自引:0,他引:5
Shuber AP; Michalowsky LA; Nass GS; Skoletsky J; Hire LM; Kotsopoulos SK; Phipps MF; Barberio DM; Klinger KW 《Human molecular genetics》1997,6(3):337-347
As more mutations are identified in genes of known sequence, there is a
crucial need in the areas of medical genetics and genome analysis for
rapid, accurate and cost-effective methods of mutation detection. We have
developed a multiplex allele-specific diagnostic assay (MASDA) for analysis
of large numbers of samples (> 500) simultaneously for a large number of
known mutations (> 100) in a single assay. MASDA utilizes
oligonucleotide hybridization to interrogate DNA sequences. Multiplex DNA
samples are immobilized on a solid support and a single hybridization is
performed with a pool of allele-specific oligonucleotide (ASO) probes. Any
probes complementary to specific mutations present in a given sample are in
effect affinity purified from the pool by the target DNA. Sequence-specific
band patterns (fingerprints), generated by chemical or enzymatic sequencing
of the bound ASO(s), easily identify the specific mutation(s). Using this
design, in a single diagnostic assay, we tested samples for 66 cystic
fibrosis (CF) mutations, 14 beta-thalassemia mutations, two sickle cell
anemia (SCA) mutations, three Tay-Sachs mutations, eight Gaucher mutations,
four mutations in Canavan disease, four mutations in Fanconi anemia, and
five mutations in BRCA1. Each mutation was correctly identified. Finally,
in a blinded study of 106 of these mutations in > 500 patients, all
mutations were properly identified. There were no false positives or false
negatives. The MASDA assay is capable of detecting point mutations as well
as small insertion or deletion mutations. This technology is amenable to
automation and is suitable for immediate utilization for high-throughput
genetic diagnostics in clinical and research laboratories.
相似文献