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Biomedical subjects

K R Abrams

Publications and source records attributed to K R Abrams.

9 recordsLinked to original sources

Rate of decline in renal function in Indo-Asians and Whites with diabetic nephropathy.

The incidence of end-stage renal failure (ESRF) is higher in the Indo-Asian ethnic group as compared to the White. To investigate whether this might be associated with faster rates of progression to ESRF in Indo-Asian diabetic patients, we studied a total of 39 Type 2 diabetic patients, using the Department of Nephrology database showing serial serum creatinine measurements from the time of first referral to the clinic until they reached a level of >500 micromol l(-1) or ESRF requiring renal replacement therapy (RRT), either dialysis or renal transplantation. They were grouped into Indo-Asian (n = 24) and White (n = 15). The rate of progression of those who developed ESRF, calculated as the slope of log serum creatinine against time, was not significantly different between the Indo-Asian and White patients, p = 0.73. We conclude that the higher incidence of ESRF in the Indo-Asian Type 2 diabetic patient with nephropathy is therefore not due to a faster rate of deterioration in renal function.

Adult

Identification of a human VPF/VEGF 3' untranslated region mediating hypoxia-induced mRNA stability.

Hypoxia is a prominent feature of malignant tumors that are characterized by angiogenesis and vascular hyperpermeability. Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) has been shown to be up-regulated in the vicinity of necrotic tumor areas, and hypoxia potently induces VPF/VEGF expression in several tumor cell lines in vitro. Here we report that hypoxia-induced VPF/VEGF expression is mediated by increased transcription and mRNA stability in human M21 melanoma cells. RNA-binding/electrophoretic mobility shift assays identified a single 125-bp AU-rich element in the 3' untranslated region that formed hypoxia-inducible RNA-protein complexes. Hypoxia-induced expression of chimeric luciferase reporter constructs containing this 125-bp AU-rich hypoxia stability region were significantly higher than constructs containing an adjacent 3' untranslated region element without RNA-binding activity. Using UV-cross-linking studies, we have identified a series of hypoxia-induced proteins of 90/88 kDa, 72 kDa, 60 kDa, 56 kDa, and 46 kDa that bound to the hypoxia stability region element. The 90/88-kDa and 60-kDa species were specifically competed by excess hypoxia stability region RNA. Thus, increased VPF/VEGF mRNA stability induced by hypoxia is mediated, at least in part, by specific interactions between a defined mRNA stability sequence in the 3' untranslated region and distinct mRNA-binding proteins in human tumor cells.

Base Sequence

Quantitative methods in nursing research.

This paper considers some of the general principles that are common to much of quantitative research in nursing. In particular, the role of hypothesis testing is considered, and the use of estimation is emphasized. Confidence intervals are advocated as a means of assessing both statistical and clinical significance. These principles and methods are illustrated using examples taken from the nursing literature. Finally, more complicated situations and the role of design are discussed.

Bias

Biopsy of inoperable pancreatic tumors does not adversely influence patient survival time.

PURPOSE: To determine the influence of pancreatic biopsy on the survival times of patients with inoperable tumors of the pancreas. MATERIALS AND METHODS: One hundred seventy patients were examined; results of histologic analysis confirmed pancreatic malignancy in 119. The biopsy and nonbiopsy groups were comparable for age, sex, the presence of liver metastases, and nodal status. RESULTS: No statistically significant difference was demonstrated between the survival time for the biopsy group (median, 23 weeks) and that for the nonbiopsy group (median, 22 weeks). The estimated relative risk for death (biopsy group compared with nonbiopsy group) was 0.85 (95% confidence limits = 0.61, 1.18). CONCLUSION: Pancreatic biopsy does not appear to adversely influence survival time for patients with inoperable pancreatic tumors. Because histologic examination aids clinical management, biopsy should be part of the diagnostic work-up for patients with suspected inoperable pancreatic carcinoma.

Aged

Modelling the pattern of cell distribution around implanted materials.

The analysis of the cellular soft tissue response has traditionally focused on using highly skilled human assessment to determine the severity or presence of a particular type of response. This has taken the form of many different assessment criteria, some even attempting some form of 'quantitative' grading index. With the complexity of this response and the availability of high performance computer systems it is not sufficient and no longer necessary to describe a tissue response subjectively. The soft tissue response to a number of implanted materials has been analysed using a combination of immunohistochemistry and image analysis to reproducibly stain and count the cells involved in a soft tissue response to implanted materials, as well as measure their position relative to the implanted material. The combination of cell count and pattern of cell distribution revealed that although the magnitude of the cellular responses changes with respect to time the position of cells with respect to an implanted material does not change significantly over time. The position of cells is controlled more by the type of implant material and the change in subject the material is implanted in.

Animals

High energy neutron treatment for pelvic cancers: study stopped because of increased mortality.

OBJECTIVE: To compare high energy fast neutron treatment with conventional megavoltage x ray treatment in the management of locally advanced pelvic carcinomas (of the cervix, bladder, prostate, and rectum). DESIGN: Randomised study from February 1986; randomisation to neutron treatment or photon treatment was unstratified and in the ratio of 3 to 1 until January 1988, when randomisation was in the ratio 1 to 1 and stratified by site of tumour. SETTING: Mersey regional radiotherapy centre at Clatterbridge Hospital, Wirral. PATIENTS: 151 patients with locally advanced, non-metastatic pelvic cancer (27 cervical, 69 of the bladder, seven prostatic, and 48 of the rectum). INTERVENTION: Randomisation to neutron treatment was stopped in February 1990. MAIN OUTCOME MEASURES: Patient survival and causes of death in relation to the development of metastatic disease and treatment related morbidity. RESULTS: In the first phase of the trial 42 patients were randomised to neutron treatment and 14 to photon treatment, and in the second phase 48 to neutron treatment and 47 to photon treatment. The relative risk of mortality for photons compared with neutrons was 0.66 (95% confidence interval 0.40 to 1.10) after adjustment for site of tumour and other important prognostic factors. Short term and long term complications were similar in both groups. CONCLUSIONS: The trial was stopped because of the increased mortality in patients with cancer of the cervix, bladder, or rectum treated with neutrons.

Fast Neutrons