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Biomedical subjects

G Li

Publications and source records attributed to G Li.

1,069 records · Page 60Linked to original sources
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Barriers to employment among working-aged patients with major burn injury.

The purpose of this study was to examine the prevalence of preexisting and burn-related impairments and to describe their association with preburn employment status. Data gathered during the acute hospitalization were analyzed on a consecutive series of burn patients aged 16 to 64 years (N = 770) enrolled in a prospective, longitudinal, multicenter study. Patients who were unemployed before the injury were more likely than those who were employed to report being alcohol-dependent (36 vs 18%), abusing other drugs (22 vs 10%), having received psychiatric treatment in the past year (21 vs 6%), and having preexisting physical disability (23 vs 3%); all were significant at P < .001). Of the unemployed patients who received toxicologic screening at admission, 49% tested positive for alcohol and 39% positive for other drugs, percentages that were significantly higher than 26 and 31%, respectively, for the employed. With adjustment for age, sex, race, and education, variables that were most predictive of preinjury unemployment status were preexisting physical disability (odds ratio, 51.0; 95% confidence interval, 7.7-336.9) and being alcohol-positive at admission (odds ratio, 2.8; 95% confidence interval, 1.2-6.8). Unemployed and employed patients also differed significantly in injury patterns and clinical outcomes, with inhalation injury and psychiatric distress being more prevalent among the unemployed and both hand burns and hand surgery among the employed. The greater prevalence of preexisting impairments among survivors who were unemployed before the injury helps explain why preburn employment status is such a powerful determinant of postburn work outcomes, and suggests the need to include psychosocial services in a program of comprehensive rehabilitation.

Adolescent↗
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Prediction of muscle recruitment and its effect on joint reaction forces during knee exercises.

This study examined the hypothesis that muscle recruitment of the tibiofemoral joint and joint reaction forces during isometric and isokinetic exercises depends on the existing degrees of freedom of the knee and the direction and type of external load applied during exercise. When three-dimensional knee joint rotation was considered (three degrees of freedom), antagonistic muscle activities were predicted using an inverse dynamic problem formulation and muscle modeling optimization procedures. The results showed that the antagonistic activities of flexors during knee flexion/extension exercise increased the joint compressive forces and decreased the anterior tibial shear forces. Comparison of different knee joint modeling assumptions indicated that modeling a single degree of freedom in flexion/extension for the knee will underestimate the antagonistic muscle function.

Biomechanical Phenomena↗
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Anchorage-independent growth of p53-knockout dermal fibroblasts is reversed by wild-type p53.

BACKGROUND: p53 is a 393-residue nuclear phosphoprotein. Mutation of p53 occurs in over half of all human cancers and thus is a crucial step in the process of cell transformation and tumorigenesis. Since tumorigenesis is a multistep process, it generally requires the mutation of certain key oncogenes and/or tumor-suppressor genes. Using p53-deficient mice, we can investigate the p53-dependent mechanisms leading to tumorigenesis. OBJECTIVE: To examine the unique anchorage-independent growth characteristics of dermal fibroblasts isolated from p53-deficient mice. METHODS: The growth characteristics of highly confluent cultured dermal fibroblasts from wild-type (p53+/+) and p53-deficient (p53-/-) mice were compared by DNA fragmentation assay, colony formation in soft agar, and overexpression of a wild-type p53 transgene in p53-deficient cells. RESULTS: p53-/- fibroblasts have a growth rate dramatically higher than p53+/+ cells and detach from plastic cultureware at high density. The detachment of p53-/- cells is not due to apoptosis. Furthermore, these cells have the capacity to grow in soft agar-a hallmark of cell transformation-and this anchorage-independent growth can be reversed by the introduction of a wild-type p53 transgene. CONCLUSION: Dermal fibroblasts isolated from p53-deficient mice show anchorage-independent growth. Therefore, the absence of p53 is sufficient for the initiation of cell transformation in this cell type and establishes this model system as an excellent tool to dissect the molecular steps involved in oncogenesis.

Animals↗
PubMedDate not supplied

Detection of SIV DNA in rhesus macaque polymorphonuclear neutrophils.

The extent of infection of monkey polymorphonuclear neutrophils (PMN) by simian immunodeficiency virus (SIV) has not yet been determined. Using the polymerase chain reaction (PCR) technique, we detected the presence of SIVmac239 DNA in rhesus macaque-derived PMN after 24 hrs of in vitro incubation of the cells with SIVmac239. Infection by SIVmac239 also down-regulated the expression of the bcl-2 apoptosis-blocking gene in the infected PMN. These SIVmac239-induced PMN intracellular alterations were correlated with an accelerated decrease in PMN viability over a period of 120 hrs compared to non-infected PMN. Evidence of chromatin condensation characteristic of programmed cell death (apoptosis) was also observed in SIVmac239-infected PMN. The results of this study provide a mechanism for the reduced chemotaxis/phagocytosis activities of PMN of SIVmac239-infected macaques and suggest that PMN is one of the target cells for SIVmac239 infection.

Animals↗
PubMedDate not supplied

Flow cytometric analysis of antigen expression in malignant and normal renal cells.

UNLABELLED: Flow cytometry allows quantitative analysis of cancer cells. The aim of this study was to make a quantitative study of antigen expression in malignant and normal renal cells in order to find the efficient monoclonal antibodies (mAbs) for labelling renal cancer cells. MATERIAL AND METHODS: 15 malignant and adjacent normal renal tissues and three renal carcinoma cell lines (ACHN, A704 and CAKI-2) were analyzed. The malignant and normal renal tissues were dissociated mechanically into cell suspension. The mAbs and isotype controls were used for immunochemical labelling. The stained cells were analyzed by flow cytometry. RESULTS: Renal tumor associated antigen G 250 was frequently detected in malignant renal cells but not in normal renal cells. Renal tumor associated antigen gp200 recognized by 66.4.C2 and PN-15 was frequently detected in malignant cells, normal renal cells and also in all three carcinoma cell lines. Epithelial antigens were strongly positive in normal renal cells. Compared with MOC 31, Ber-EP4 and E 29, W-lD9 was mostly reactive to malignant renal cells. VU-1D9 was strongly positive on ACHN and A704. The carbohydrate carcinoma antigens CA 125, DF3 and Sialyl Lewis(a) were detectable in some of the malignant and normal renal cells. Sialyl Lewis(a) could be weakly detected on ACHN and A 704. Pan-cytokeratins and cytokeratin (CK) 8 were strongly expressed in malignant and normal renal cells and in all three cell lines. CONCLUSION: Our results indicated that G 250, 66.4.Ca, PN-15, VU-1D9, MNF116 and anti-ckg were efficient mAbs for labelling renal cancer cells. Their potential clinical application by flow cytometry should be explored.

Adult↗
PubMedDate not supplied

Functional recovery in rabbit heart after preservation with a blood cardioplegic solution and perfusion.

Thirty-five isolated rabbit hearts were subjected to 60 minutes of storage after cardiac arrest with high K+ crystalloid cardioplegic solution at 5 degrees C. They were divided into five groups (n = 7 per group) according to the preservative protocol: group I (simple immersion in 0 degrees C normal saline solution), group II (simple immersion in 30 degrees C blood cardioplegic solution), group III (immersion and perfusion in 30 degrees C blood cardioplegic solution), group IV (simple immersion in 10 degrees C blood cardioplegic solution), and group V (immersion and perfusion in 10 degrees C blood cardioplegic solution). After storage for 1 hour, cardiac function, tissue water content, and the number of hearts capable of ejecting against a 100 cm H2O column afterload were recorded and compared among the five groups. Cardiac function in group II was not different from group I. Aortic pulse pressure and left ventricular developed pressure were lower in group II than in group III, IV, or V. Aortic developed pressure was higher in groups III and V (p < 0.05). Tissue water content in group I was significantly higher than in groups II, III, and V (p < 0.05). All hearts in groups III and V could eject against a 100 cm H2O afterload after preservation (p < 0.05 versus groups I, II, and IV). Factorial analysis among the groups using blood cardioplegic solution showed that either hypothermia or perfusion alone or the combination was a protective factor in providing functional recovery of stored hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗