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排序方式: 共有3243条查询结果,搜索用时 15 毫秒
101.
LA Nicolette KW Reichard K Falkenstein A Pierson SP Dunn 《Canadian Metallurgical Quarterly》1998,33(6):909-912
B-chronic lymphocytic leukemia (CLL) is characterized by an accumulation of long-lived, resting B cells expressing the Bcl-2 protein. However, less than 10% of the CLL patients shows bcl-2 gene rearrangement in blood cells, using traditional Southern blotting analysis. In the present study, rearrangement of the bcl-2 gene in CLL cells was studied by pulsed-field gel electrophoresis (PFGE). With this method, large DNA fragments (> 50-10,000 kb) could be analyzed. Blood CLL cells from 9 of 9 patients and 2 of 2 CLL cell lines showed rearranged bcl-2 gene. In comparison, healthy blood B cells and lymphoblastoid cell lines (LCLs) established from normal peripheral blood lymphocytes of the patients showed only germ line configuration. Thus, the possibility of restriction fragment length polymorphisms (RFLPs) in this gene could be excluded. The primary cell involved in CLL might be a progenitor B cell that has accidentally rearranged the bcl-2 gene. As a consequence, such cells express stable amount of Bcl-2 protein and do not enter apoptosis. During prolonged survival, such cells may acquire secondary changes including chromosomal translocations and mutations. 相似文献
102.
AJ Marshall N Doyen LA Bentolila CJ Paige GE Wu 《Canadian Metallurgical Quarterly》1998,161(12):6657-6663
During neonatal life, Ig diversity is limited in many respects. The absence of terminal deoxynucleotidyl transferase (TdT) expression with the consequent lack of nontemplated addition during the neonatal period, coupled with the predominant usage of a single D(H) reading frame (RF), leads to severe limitations of diversity in the CDR3 region of Ig heavy (H) chains. The neonatal Ig H chain repertoire is also characterized by restricted V(H) usage, with predominant expression of certain V(H) segments, such as V(H)81x, that are rarely evident during adult life. In this report, we examine the effect of enforced TdT expression on the neonatal repertoire of V(H)81xDJ(H) rearrangements. We find that TdT synthesis abrogates D(H) RF bias during the fetal/neonatal period through a Ig-receptor-independent mechanism. These findings suggest that D(H) RF bias during neonatal life is determined largely by homology-directed joining. We also find that TdT synthesis alters the selection of productively rearranged V(H)81xDJ(H) alleles in the neonatal spleen through a Ig-receptor-dependent mechanism. Analysis of predicted CDR3 amino acid sequences indicates that positive selection of V(H)81x-encoded H chains is correlated with the presence of a consensus sequence immediately adjacent to the V(H) segment. These data support the hypothesis that the CDR3 region is critical in determining the ability of V(H)81x-encoded H chains to form functional receptors that support positive selection of B lymphocytes. Together, our results demonstrate that TdT can indirectly influence the Ig repertoire by influencing both receptor-dependent and receptor-independent selection processes. 相似文献
103.
GL DeNardo SJ DeNardo DS Goldstein LA Kroger KR Lamborn NB Levy JP McGahan Q Salako S Shen JP Lewis 《Canadian Metallurgical Quarterly》1998,16(10):3246-3256
PURPOSE: Lym-1, a monoclonal antibody that preferentially targets malignant lymphocytes, has induced remissions in patients with non-Hodgkin's lymphoma (NHL) when labeled with iodine 131 ((131)I). Based on the strategy of fractionating the total dose, this study was designed to define the maximum-tolerated dose (MTD) and efficacy of the first two, of a maximum of four, doses of (131)I-Lym-1 given 4 weeks apart. Additionally, toxicity and radiation dosimetry were assessed. MATERIALS AND METHODS: Twenty patients with advanced NHL entered the study a total of 21 times. Thirteen (62%) of the 21 entries had diffuse large-cell histologies. All patients had disease resistant to standard therapy and had received a mean of four chemotherapy regimens. (131)I-Lym-1 was given after Lym-1 and (131)I was escalated in cohorts of patients from 40 to 100 mCi (1.5 to 3.7 GBq)/m2 body surface area. RESULTS: Mean radiation dose to the bone marrow from body and blood (131)I was 0.34 (range, 0. 1 6 to 0.63) rad/mCi (0.09 mGy/MBq; range, 0.04 to 0.17 mGy/ MBq). Dose-limiting toxicity was grade 3 to 4 thrombocytopenia with an MTD of 100 mCi/m2 (3.7 GBq/m2) for each of the first two doses of (131)I-Lym-1 given 4 weeks apart. Nonhematologic toxicities did not exceed grade 2 except for one instance of grade 3 hypotension. Ten (71 %) of 14 entries who received at least two doses of (131)I-Lym-1 therapy and 11 (52%) of 21 total entries responded. Seven of the responses were complete, with a mean duration of 14 months. All three entries in the 100 mCi/m2 (3.7 MBq/m2) cohort had complete remissions (CRs). All responders had at least a partial remission (PR) after the first therapy dose of (131)I-Lym-1. CONCLUSION: (131)I-Lym-1 induced durable remissions in patients with NHL resistant to chemotherapy and was associated with acceptable toxicity. The nonmyeloablative MTD for each of the first two doses of (131)I-Lym-1 was 100 mCi/m2 (total, 200 mCi/m2) (3.7 GBq/m2; total, 7.4 GBq/m2). 相似文献
104.
105.
A Sarría LA García-Llop LA Moreno J Fleta MP Morellón M Bueno 《Canadian Metallurgical Quarterly》1998,52(8):573-576
OBJECTIVES: Risk factors for increased blood lead concentration (BPb) has been investigated. However, the effect of sibship and Chinese herbal medicine on BPb has not been systematically studied. In this study BPb data from voluntary testing was used to determine if Chinese herbal medicine and sibship were associated with BPb. METHODS: 319 children aged 1-7 were tested for BPb. Meanwhile, parents were interviewed to obtain information including consumption of Chinese herbal medicine, living environment, lifestyle, and sibship of the children tested. RESULTS: The mean (SD) BPb of 319 preschool children was 4.4 (2.4) micrograms/dl. The consumption of Ba-baw-san (a Chinese herbal medicine) was significantly associated with increased BPb in children (p = 0.038). Further multivariate regression analysis of BPb in 50 pairs of siblings showed the factors of being brothers explained 75% of variation for BPb, and being sisters and brother-sister explained 51% and 41% of variation respectively. CONCLUSION: Chinese herbal medicine and children's play patterns within the family expressed in different types of sibship are the main determinants of low concentrations of BPb in preschool children of Taiwan. 相似文献
106.
The purpose of this study was to assess the effect of psychiatric illness on length of stay and patterns of admission among AIDS patients hospitalized for medical illnesses. Medical records were abstracted for AIDS patients admitted to hospitals in Washington State from 1990 through 1992. Psychiatric comorbidity was defined by the presence of an International Classification of Disease-9 code reflecting psychiatric illness. Medical morbidity was addressed using CD4 count and AIDS-defining illnesses as markers of disease severity. Of 2834 admissions, 15% included one or more psychiatric diagnoses. Psychiatric illness (F 39.1; df 1,2830; p < 0.001) and discharge disposition (F 81.2; df 2,2830; p < 0.001) contributed significantly to the model, explaining increased length of stay (F 67.2; df 3,2830; p < 0.001). Future research needs to address the possible etiology of psychiatric comorbidity's contribution to length of stay and the effect on quality and cost of care. 相似文献
107.
We investigated the contact guidance phenomenon of rat dermal fibroblasts (RDF) on microgrooved polystyrene substrates. Grooves were 1 microm deep, and between 1 and 10 microm wide. Light microscopy and digital image analysis (DIA) showed that RDF were oriented on all microgrooved substrates. Scanning electron microscopy showed that RDF cultured on 1 or 2 microm wide grooves were positioned on top of the ridges. On the wider 5 and 10 microm grooves, the cells were able to descend into the grooves. In confocal laser scanning microscopy, focal adhesions were lying in the same direction as the actin filament where they attached to. DIA confirmed an orientational behavior of focal adhesions and actin filaments on microgrooves. There were no differences in the measured orientation between the different grooves. Besides, no obvious preference was found for focal adhesions to lie along edges of the surface ridges. Transmission electron microscopy showed that focal adhesions were able to bend along the edges of ridges. On the basis of our observations, we suggest that the breakdown and formation of fibrous cellular components, especially in the filopodium, is influenced by the microgrooves. The microgrooves create a pattern of mechanical stress, which influences cell spreading and cause the cell to be aligned with surface microgrooves. 相似文献
108.
109.
KL Hammond IM Hanson AG Brown LA Lettice RE Hill 《Canadian Metallurgical Quarterly》1998,74(1-2):121-131
The human myeloid leukemias are a diverse group of disorders characterized by massive clonal expansion of myeloid cells showing variable degrees of differentiation block. Leukemic dendritic cells were generated in culture from chronic myelogenous leukemia (CML). These were used to stimulate autologous T cells to develop leukemia-specific cytotoxicity. Available data suggest that the cells responsible for the cytolytic activity are at least in part CD8+ and HLA restricted in their function. Additional data suggest that some anti-CML cellular activity may be Fas mediated. T-cell receptor studies provide evidence for an oligoclonal response implying a recognition of a limited number of antigens. We have used culture techniques similar to those used for CML to study the ability of AML cells to differentiate toward dendritic cells. Four of five patients have shown acute leukemia-derived dendritic cells. This work offers an avenue for the development of novel strategies for the control of human myeloid leukemias. 相似文献
110.
A male, wild-caught kangaroo rat developed anorexia and wasting. The animal was euthanized and a gastric trichobezoar found at necropsy. The paucity of information regarding the clinical medicine of this species is a hindrance to those charged with the care of kangaroo rats. Gastric trichobezoar should be considered as a differential diagnosis in cases of anorexia in kangaroo rats. 相似文献