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141.
Bone marrow and peripheral blood cultures of chronic lymphocytic leukemia patients were mitogenically stimulated with TPA (12-0-tetradecanylphorbol-13-acetate). Clonal cytogenetic abnormalities were detected in frequencies varying from 15% to 100%, in five of the six patients studied. Parallel studies with pokeweek mitogen showed a much lower level of stimulation and only two abnormal clones were detected. The chromosome abnormalities described in this study are similar to those reported in CLL by other authors, particularly with respect to trisomy 12 and deletion 11q. A significant frequency of hypodiploidy and chromosome deletion was also detected in this study, and further studies are underway to determine the significance of these findings. 相似文献
142.
Localization of IFN-gamma-activated Stat1 and IFN regulatory factors 1 and 2 in breast cancer cells.
Judith M Connett Steven R Hunt Suzanne M Hickerson Susan J Wu Gerard M Doherty 《Journal of interferon & cytokine research》2003,23(11):621-630
The aim of the present work was to evaluate the induction and localization of Stat1, interferon (IFN) regulatory factor-1 (IRF-1), and IRF-2 after IFN-gamma exposure of human breast cancer cell lines, SKBR3, MDA468, MCF7, and BT20. Results from growth assays, Western staining, electrophoretic mobility shift assay (EMSA), and immunohistochemical staining were collated to test our hypothesis that immunohistochemical analysis of Stat1, IRF-1, and IRF-2 would provide additional information about the functionality of the IFN-gamma signaling pathway in human tumor lines. EMSA results showed that in each of four cell lines, Stat1 expression was increased and demonstrated functional activity after IFN-gamma stimulation. Western and EMSA analysis showed upregulation of IRF-1 but not IRF-2 in each cell line. Confocal microscopy of cells stained for Stat1, IRF-1, and IRF-2 confirmed the results and also provided novel information about the intracellular localization of proteins and intercellular variations in responses. The proportion of cells with IRF-1 stimulation and translocation was positively correlated with the IFN-gamma growth suppression in vitro. In conclusion, using four independent assays, we have demonstrated that heterogeneity in IFN-gamma-mediated upregulation of signal transduction proteins can be detected in vitro and that these differences can explain distinct cellular growth effects. 相似文献
143.
Spatial dependence exists when the variation between observations is dependent on spatial location. In the present study, geostatistical methods were used to examine spatial dependence in adolescents' perceptions of their neighborhoods: whether adolescents living in close proximity perceived their neighborhoods more similarly than adolescents living further apart. Participants included 343 adolescents (53% male; 91% African American) enrolled in sixth grade, residing in Baltimore City, with geocoded home addresses. These addresses were used in combination with a measure of perceived neighborhood disorder and disadvantage to compute variogram plots, a geostatistical technique used to evaluate spatial dependence. Results indicated that perceptions of youth residing in close geographic proximity were more similar than perceptions of youth residing further apart. Adjusting for census‐level characteristics, but not individual and family characteristics, resulted in decreased variation among participants but did not eliminate the spatial dependence. Findings highlight the utility of geostatistical methods for social science research. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 277–293, 2004. 相似文献
144.
Yoshitaka Iwasaki Judith Bartlett Kelly MacKay Jennifer Mactavish Janice Ristock 《Journal of community psychology》2008,36(6):702-722
This study reports key findings from a research project, which examined the stress and coping mechanisms of several nondominant groups of individuals. The groups were based in Winnipeg, Manitoba, Canada and included (a) Aboriginal individuals with diabetes, (b) individuals with disabilities, and (c) gays and lesbians. Our analyses of personal narratives and life stories have led to develop an interpretive map of findings that depicts mechanisms of how stress and coping operate. Specifically, the interpretive map consists of personal and structural stressors, meanings of stress, and personal and structural resources, as well as of two constructs termed intersectionality and social exclusion. Not only are nondominant voices and lived experiences recognized and incorporated into an emergent interpretive map, but this map also articulates the complex ways in which multiple identities intersect (i.e., intersectionality) and the realities of being excluded socioeconomically, culturally, and politically among nondominant groups (i.e., social exclusion). © 2008 Wiley Periodicals, Inc. 相似文献
145.
William B. Hansen John W. Graham Judith L. Sobel David R. Shelton Brian R. Flay C. Anderson Johnson 《Journal of behavioral medicine》1987,10(6):559-579
The purpose of this study was to determine the degree to which the use of tobacco, alcohol, and marijuana by young adolescents can be described using a common theoretical model. Structural models were created in which psychosocial variables hierarchically predicted the use of each substance. The fit of a model in which paths from predictor variables were constrained to be equal was not inferior in any meaningful way to that of a model in which all path coefficients were freely estimated, thus suggesting that use of tobacco, alcohol, and marijuana by young adolescents may be considered to be a unitary phenomenon. A simplified model, in which these substances were combined into a single latent variable, showed a good fit. The results of these analyses suggest that it may be beneficial to consider adolescent substance use to be a unitary phenomenon.This research was supported by National Institute on Drug Abuse Grant 1-R18-DA-003406. 相似文献
146.
Interaction of Blastomyces dermatitidis, Sporothrix schenckii, and Histoplasma capsulatum with Acanthamoeba castellanii
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Several dimorphic fungi are important human pathogens, but the origin and maintenance of virulence in these organisms is enigmatic, since an interaction with a mammalian host is not a requisite for fungal survival. Recently, Cryptococcus neoformans was shown to interact with macrophages, slime molds, and amoebae in a similar manner, suggesting that fungal pathogenic strategies may arise from environmental interactions with phagocytic microorganisms. In this study, we examined the interactions of three dimorphic fungi with the soil amoeba Acanthameobae castellanii. Yeast forms of Blastomyces dermatitidis, Sporothrix schenckii, and Histoplasma capsulatum were each ingested by amoebae and macrophages, and phagocytosis of yeast cells resulted in amoeba death and fungal growth. H. capsulatum conidia were also cytotoxic to amoebae. For each fungal species, exposure of yeast cells to amoebae resulted in an increase in hyphal cells. Exposure of an avirulent laboratory strain of H. capsulatum to A. castellanii selected for, or induced, a phenotype of H. capsulatum that caused a persistent murine lung infection. These results are consistent with the view that soil amoebae may contribute to the selection and maintenance of certain traits in pathogenic dimorphic fungi that confer on these microbes the capacity for virulence in mammals. 相似文献
147.
Goujard C Bernard N Sohier N Peyramond D Lançon F Chwalow J Arnould B Delfraissy JF 《Journal of acquired immune deficiency syndromes (1999)》2003,34(2):191-194
Patients' knowledge of their HIV condition and its treatment, which has been recognized as a factor that influences adherence to antiretroviral therapy, can be improved through educational programs. This prospective, randomized, controlled trial compared an experimental group that participated in an educational program and a control group with standard care. The study evaluated the impact of an educational intervention on adherence to antiretroviral therapy, patients' knowledge, quality of life, and therapeutic response in patients treated with highly active antiretroviral therapy. Three hundred twenty-six patients were analyzed at inclusion. A higher level of adherence was associated with patients who were older, had higher incomes, and did not smoke. CD4 cell count and plasma viral load were correlated with adherence at entry. The educational intervention had an impact on adherence and knowledge in the experimental group at 6 months, which was maintained at 12 and 18 months. A delayed increase in adherence was observed in the control group at 12 months. No significant impact on quality of life was observed over time. The patients' health status improved in 56% of the experimental group subjects and 50% of the control subjects. However, no significant impact was shown on CD4 cell count and plasma viral load. This study shows that an educational intervention improves adherence to antiretroviral regimens and health status and suggests that it should be initiated early in therapy. 相似文献
148.
Tolerance to self gangliosides is the major factor restricting the antibody response to lipopolysaccharide core oligosaccharides in Campylobacter jejuni strains associated with Guillain-Barré syndrome
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Bowes T Wagner ER Boffey J Nicholl D Cochrane L Benboubetra M Conner J Furukawa K Furukawa K Willison HJ 《Infection and immunity》2002,70(9):5008-5018
Guillain-Barré syndrome following Campylobacter jejuni infection is frequently associated with anti-ganglioside autoantibodies mediated by molecular mimicry with ganglioside-like oligosaccharides on bacterial lipopolysaccharide (LPS). The regulation of antibody responses to these T-cell-independent antigens is poorly understood, and only a minority of Campylobacter-infected individuals develop anti-ganglioside antibodies. This study investigates the response to gangliosides and LPS in strains of mice by using a range of immunization strategies. In normal mice following intraperitoneal immunization, antibody responses to gangliosides and LPS are low level but can be enhanced by the antigen format or coadministration of protein to recruit T-cell help. Class switching from the predominant immunoglobulin M (IgM) response to IgG3 occurs at low levels, suggesting B1-cell involvement. Systemic immunization results in poor responses. In GalNAc transferase knockout mice that lack all complex gangliosides and instead express high levels of GM3 and GD3, generation of anti-ganglioside antibodies upon immunization with either complex gangliosides or ganglioside-mimicking LPS is greatly enhanced and exhibits class switching to T-cell-dependent IgG isotypes and immunological memory, indicating that tolerance to self gangliosides is a major regulatory factor. Responses to GD3 are suppressed in knockout mice compared with wild-type mice, in which responses to GD3 are induced specifically by GD3 and as a result of polyclonal B-cell activation by LPS. The anti-ganglioside response generated in response to LPS is also dependent on the epitope density of the ganglioside mimicked and can be further manipulated by providing secondary signals via lipid A and CD40 ligation. 相似文献
149.
Andreas W. Jehle Judith Forgo J. Biber Eleanor Lederer Reto Krapf Heini Murer 《Pflügers Archiv : European journal of physiology》1998,437(1):149-154
Insulin-like growth factor (IGF)-I and vanadate increase Na-dependent phosphate (Na/Pi) cotransport in opossum kidney (OK) cells. To gain more information about the mechanisms by which IGF-I and vanadate stimulate
Na/Pi-cotransport, we measured type II Na/Pi-cotransporter (NaPi-4) protein abundance by Western blot analysis and investigated the effects of protein synthesis and tyrosine
kinase inhibitors. The key findings in the present studies are as follows. First, incubation in IGF-I (10–8 M) and/or vanadate (10–3 M) for 3 h led to a non-additive 1.4-fold increase in Na/Pi-cotransport activity which was paralleled by a 1.5- to 2-fold increase in NaPi-4 protein. Second, actinomycin D did not abolish
the increase in Na/Pi-cotransport and cycloheximide did not prevent the IGF-I-induced increase in Na/Pi-cotransport and NaPi-4 protein. Third, among the protein kinase inhibitors tested, only staurosporine substantially reduced
the stimulation of Na/Pi-cotransport. In conclusion, the stimulatory effect of IGF-I on Na/Pi-cotransport is paralleled by an increased expression of NaPi-4 protein that is independent of protein synthesis and therefore
results from increased protein stability. The observation that IGF-I and/or vanadate lead to similar increases in Na/Pi-cotransport and NaPi-4 protein abundance provides further evidence that the stimulation of Na/Pi-cotransport by IGF-I and vanadate involves protein tyrosine phosphorylation of the same signalling molecules.
Received: 1 May 1998 / Received after revision: 25 August 1998 / Accepted: 1 September 1998 相似文献
150.
The specification of a germ cell as sperm or oocyte and determination of cell number remain unsolved questions in developmental biology. This paper examines Caenorhabditis elegans FOG-1, a CPEB-related RNA-binding protein that controls the sperm fate. We find that abundant FOG-1 protein is observed transiently in germ cells just prior to their expression of an early sperm-differentiation marker. As the germline tissue elongates, abundant FOG-1 appears more and more distally as sperm become specified, but disappears when the germ line switches to oogenesis. This dynamic pattern is controlled by both globally acting and germline-specific sex-determining regulators. Importantly, the extent of FOG-1 expression corresponds roughly to sperm number in wild-type and mutants, altering sperm number. By contrast, three other key regulators of the sperm/oocyte decision do not similarly correspond to sperm number. We suggest that FOG-1 is precisely modulated in both time and space to specify sperm fate and control sperm number. 相似文献