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31.
In vitro IgA synthesis induced by pokeweed mitogen (PWM), Staphylococcus aureus Cowan I (STA), and combinations of STA and PWM (STA/PWM) was studied in lymphocytes of IgA deficient (sIgAd) blood donors. Cultures of T-depleted (non-T) cells with autologous or allogeneic control T, irradiated T (T), or T4 cells suggested abnormalities in non-T cell fractions in most (12/22) sIgAd donors. T cell abnormalities in themselves, detectable in six donors, did not appear to account for the failure of IgA synthesis. Repeat studies in 10 donors indicated fluctuations in in vitro IgA synthesis in four. IgA synthesis induced by STA/PWM combinations was observed in only one of eight sIgAd donors. Our findings suggest that in some donors defects leading to failure to produce IgA may not be constant and support the hypothesis of a maturation arrest in IgA+ B cells in sIgAd donors.  相似文献   
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Amphibians, and particularly the African clawed frog Xenopus laevis, have been used for more than a century as models of vertebrate embryonic development. However, in many cases, elucidation of developmental functions of specific gene sequences could be severely impeded, because X. laevis is a tetraploid species, with multiple functional copies of many genes of interest. Recent studies have shifted focus to the West African or tropical clawed frog, X. tropicalis, the only known diploid species of the genus Xenopus. Here, we present two preliminary linkage maps, constructed by analysis of joint segregation of amplified fragment length polymorphism (AFLP) markers in a X. tropicalis interstrain hybrid. A total of 53 markers, including 51 AFLP markers and 2 isozyme markers, are presently assigned to 13 multipoint linkage groups on a map of the maternal strain, whereas 9 AFLP markers from the paternal strain are assigned to 3 linkage groups on a separate map. A dense genetic linkage map is essential in mapping new developmental mutants and determining their sequences by positional cloning.  相似文献   
34.
Human polymorphonuclear leukocyte interaction with cyclosporine A.   总被引:4,自引:1,他引:4       下载免费PDF全文
The effects of cyclosporin A (cyA) on human polymorphonuclear leukocyte function, including phagocytosis, its associated metabolic burst, bacterial killing, and chemotaxis, were evaluated. Both Pseudomonas aeruginosa and Staphylococcus aureus were used as test particles. Polymorphonuclear leukocytes incubated in 10 and 50 micrograms of cyA per ml behaved normally with respect to phagocytosis and hexose monophosphate shunt activity at both high (10:1) and low (2:1) S. aureus/leukocyte ratios. With a small bacterial inoculum, killing of S. aureus was slightly impaired at early times only in the presence of 50 micrograms of cyA per ml. Phagocytosis and killing of P. aeruginosa with both large and small bacterial inocula were unaffected by cyA. Chemotaxis was within normal limits under all conditions. In addition, polymorphonuclear leukocytes from four renal transplant recipients receiving both cyA and prednisone demonstrated normal metabolic bursts and bacterial killing with both small and large inocula of S. aureus.  相似文献   
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According to the reformulated learned helplessness model of depression, causal attributions are an important mediator of the effects on mood of positive and negative experiences. Adaptive attributions for negative events are assumed to be external, unstable, and specific. In the present study, subjects exposed to one of two attribution training procedures or a control condition made attributions for hypothetical events under neutral and adaptive instructional sets. Attributions were rated by subjects and coders blind to the purpose of the study. Results indicated that subjects' views of adaptive causal attributions were congruent with predictions from the learned helplessness model. The ratings of the objective coders indicated that subjects' attributions really did change in response to the adaptive instructions in the predicted direction. Implications of these results for the reformulated learned helplessness model and depression therapies that include an attribution retraining component are discussed.The authors would like to thank Dan Russell for his very helpful comments on earlier drafts of this paper.  相似文献   
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Rhabdomyosarcoma (RMS) is a common malignancy in children, but embryonal rhabdomyosarcoma (ERMS) deposits rarely occur in the breast in adults. Therefore, little is known about magnetic resonance imaging (MRI) features of breast metastases from RMS, especially the embryonal type. We reported a case of a 22-year-old woman who was diagnosed with ERMS at left foot 2 years ago and accepted operation and chemotherapy. She was confirmed to have breast metastases from the left foot. Successive imaging examinations were performed 3 months apart. Breast ultrasound indicated a benign lesion, and further examination did not reveal any bone metastases. However, predominant restricted diffusion and rim contrast enhancement on MRI combined with the patient's medical history suggested a malignancy of BI-RADS 5. After 3 months, breast ultrasound revealed masses detected last time became larger and lobulated. In addition, internal heterogeneous intensity and rim contrast enhancement with restricted diffusion were revealed on MRI. We speculated that typical MRI findings of breast metastases from RMS may include iso- to hypointensity on T1WI, heterogeneous hyperintensity on T2WI, and circular enhancement with restricted diffusion. Moreover, mild peritumoral edema, rapid expansion of necrosis, and ascending time-intensity curve detected on MRI may be features of the ERMS type.  相似文献   
39.
Pneumococcal vaccine. Efficacy and associated cost savings   总被引:4,自引:0,他引:4  
We evaluated the efficacy and cost savings of the pneumococcal pneumonia vaccine in a retrospective cohort study of 762 vaccinated and 1161 randomly selected unvaccinated age-sex matched persons in Blue Cross/Blue Shield of Minnesota using medical and pharmaceutical claims. The pneumonia incidence and the ratio of incidence in the postvaccination to prevaccination periods (rate ratio) were examined in the vaccine group by sex and risk factors. Vaccination significantly reduced pneumonia incidence, with overall efficacy of 69% and higher efficacy in women (86%) than in men (33%). We assigned persons to risk categories based on disease conditions as recorded in the claims by the ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) diagnostic codes. In the risk categories, efficacy varied from 50% to 75% and was confounded by sex. Immunocompromised and immunocompetent women had high efficacy (83% to 88%), while immunocompetent and immunocompromised men had lower efficacy (33%). Persons with a precondition of pneumonia exhibited similar vaccine efficacy to the overall cohort relative to the comparison group. Projected costs of pneumonia cases are 3.6 times the observed costs of vaccination and postvaccination pneumonia costs. We conclude that the pneumococcal pneumonia vaccine is efficacious in persons having had pneumonia, persons "at risk" of developing pneumonia, or persons over 50 years of age, and it corresponds to overall savings of $141 per person.  相似文献   
40.
The aim of this study was to determine the number and size of apical non-myelinated (C) axons of healthy human premolars. The material was derived from a large collection of specimens prepared for a previous quantitative investigation on the myelinated (A) axons of human premolars. A total of 16 teeth (six maxillary first and five each of mandibular first and second premolars), removed from adolescents for orthodontic reasons, were used. Root discs of about 0.6 mm thickness were prepared at about 2 mm cervical to the root apex and processed for light and electron microscopy. The number of non-myelinated axons was determined by taking a total census of such fibres that could be identified and reconstructed by standardized composite electron micrographs from each root disc. The measurement of axons was done on a statistically representative sample of axons (n=1810) using an electronic image processing unit. The 16 teeth had an average of 2000 ± 1023 non-myelinated axons at the juxta-apical level (range 534–3912). The average diameter of the non-myelinated axons was found to be 0.5 ± 0.4 m (range 0.05–2.4 m).  相似文献   
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