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Biomedical subjects

C Zhu

Publications and source records attributed to C Zhu.

231 records · Page 13Linked to original sources
PubMed1986

A t(8;14)(q24;q11) translocation in a T-cell leukemia (L1-ALL) with c-myc and TcR-alpha chain locus rearrangements.

Cell lines established from T-cell leukemias have recently been reported to exhibit a chromosome translocation t(8;14) involving proto-oncogene c-myc and the gene of the T-cell receptor alpha-chain(TcR-alpha). In this work, we have studied a case of T-cell leukemia presenting a t(8;14)(q24;q11) translocation that was found in fresh leukemic cells taken during relapse, but was absent in cells collected at diagnosis. Hybridization analysis showed that the breakpoint on chromosome 8 was located 3' to the c-myc exon 3. A TcR-alpha-specific original probe (D14S7, Mathieu-Mahul et al., 1985) revealed two differently rearranged patterns in DNA from leukemic cells obtained at diagnosis and during relapse. In contrast, the rearranged TcR-beta-gene DNA pattern did not change during the course of the disease, indicating that leukemic cells were clonally related. These data indicate that the chromosome breakpoint in 14q11 is situated in the TcR-alpha locus. These results suggest that translocations t(8;14) involving TcR-alpha and c-myc genes in T-cell malignancies are analogous to variant t(2;8) and t(8;22) translocations observed in Burkitt lymphoma. They also establish that the same types of molecular rearrangements due to a t(8;14)(q24;q11) translocation, at first described in T-cell lines established in culture, also exist in vivo and may play a role in the evolution of the leukemic process.

Child↗
PubMedDate not supplied

Transplantation of preconditioned intestinal grafts is associated with lower inflammatory activation and remote organ injury in rats.

Reperfused grafts--particularly the intestine--release free radicals and cytokines into the systemic circulation. The type of discharge, which is greatly dependent on the local injury, may also induce inflammatory activation in distant organs and leading to multiple system and organ failure. It has been suggested that intestinal grafts from tacrolimus (TRL)-pretreated donors show improved morphology and microcirculation. We studied whether transplantation of intestines from TRL-pretreated donors influenced inflammatory response and remote organ injury posttransplantation. Donor Sprague Dawley rats received TRL or saline (controls) intravenously at 6 hours prior to graft harvest. The intestinal grafts were preserved in saline for 3 hours before transplantation. At 6 and 12 hours postreperfusion hepatic and renal cortical microcirculation were assessed using laser-Doppler flowmetry (n = 8-12 per group). Blood pressure was measured; liver, kidney, and serum samples were obtained. We analyzed hepatic and renal ICAM-1 expression and caspase-3-like activity as well as plasma content of tumor necrosis factor-alpha and interleukin-6. Pretreated graft recipients had higher mean arterial pressure (82 +/- 10 vs 51 +/- 17 mm Hg, P < .05) and renal perfusion at 6 hours whereas liver perfusion was similar at both 6 and 12 hours. Liver and renal functions were also superior among recipients of pretreated grafts. Both caspase-3-like activity and ICAM-1 expression in liver and kidney were lower in pretreated graft recipients. Plasma IL-6 levels were lower in animals receiving pretreated grafts. Transplantation of intestines from TRL-pretreated donors was followed by a lower systemic inflammatory response, improved organ function and decreased remote injury early posttransplantation compared with animals receiving grafts from untreated donors.

Animals↗
PubMedDate not supplied

Susceptibility of cultured rat hepatocytes to oxidative stress by peroxides and iron. The extracellular matrix affects the toxicity of tert-butyl hydroperoxide.

The aim of this study was to set up an in vitro model for studying the importance of an altered extra-cellular matrix composition and its importance for the resistance to oxidative stress, in hepatocytes from normal and iron loaded rats. Primary cultures of hepatocytes from iron loaded and normal rats were plated on a laminin rich extracellular matrix or on collagen type I, and incubated with tert-butyl hydroperoxide (TBH). Malon dialdehyde (MDA) and the activities of lactate dehydrogenase (LDH) in cell culture medium were analyzed. The protein synthesis, the concentrations of glutathione and the expression of manganese-superoxide dismutase and ferritin genes were measured. All hepatocytes contained lower concentrations of glutathione when plated on collagen than on EHS. Ferritin H and Mn-SOD gene expression showed no difference. The rate of lipid peroxidation in iron loaded hepatocytes exposed to TBH was higher on collagen than in those plated on EHS (0.95 +/- 0.28 microM MDA vs. 1.62 +/- 0.22 microM MDA, p < 0.05). Iron loaded cells were in general more susceptible to TBH than were normal hepatocytes (MDA, LDH, protein synthesis and glutathione content). Lipid peroxidation could be prevented by adding desferrioxamine. In conclusion, we show that the combination of iron overload and collagen matrix in rat hepatocytes leads to an increased susceptibility to oxidative stress. These findings may be of interest for the further studies on effects of iron overload and the altered matrix composition in liver fibrosis.

Animals↗
PubMedDate not supplied

A comparison of AIDS-defining events and subsequent CDC stage IV events in IDUs and gay men.

The two major risk groups for acquisition of HIV in the UK are gay men and IDUs. Individuals from these risk groups vary in a number of respects in their life-style, which have the potential to affect the course of their HIV disease. This study compares gay men and IDUs from the Lothian Region of Scotland with respect to their AIDS defining diagnosis and subsequent CDC (Centers for Disease Control) stage IV events. Comparisons were made between the two risk groups for their AIDS defining diagnosis by performing chi square tests, Mann-Whitney tests and logistic regression. Subsequent CDC stage IV events were analysed using ordinal logistic regression and Cox regression. 89 IDUs and 56 gay men were included in the analysis. Oesophageal candida was a commoner AIDS-defining diagnosis in IDUs than gay men and Kaposi's sarcoma was diagnosed more frequently in gay men than IDUs. Subsequently oesophageal candida was also commoner in IDUs and CMV retinitis was seen more frequently in gay men. The role of prophylaxis and differences in diet are discussed as possible causes of the observed differences in the incidence of oesophageal candida. The higher incidence of CMV retinitis in gay men probably reflects the high level of sexual acquisition of CMV.

AIDS-Related Complex↗
PubMedDate not supplied

A longitudinal comparison of the AIDS-related attitudes and knowledge of parents and their children.

As part of an evaluation of an experimental school-based AIDS risk-reduction program, data from 2,392 middle-school students in 15 high-risk school districts and from 1,627 of their parents were compared to examine how young adolescents and their parents differ with respect to AIDs-related knowledge and attitudes. At the time of the seventh-grade pretest, parents knew significantly more about AIDS than their children did. At the eighth-grade posttest, students who participated in the program knew either more than or at least as much as their parents in several subject areas, while among those not exposed to the program, parents still knew more than their children in most areas. The intervention had a positive impact on students' attitudes toward people with AIDS and on their degree of comfort about discussing with their parents such issues as drug use and sexuality.

Acquired Immunodeficiency Syndrome↗