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Biomedical subjects

E Marshall

Publications and source records attributed to E Marshall.

At least 451 records · Page 25Linked to original sources
PubMed1989

Prevalence of nucleoside diphosphate kinase autophosphorylation in human colon carcinoma versus normal colon homogenates.

The G-regulatory proteins of adenylate cyclase, tubulin, and the ras oncogene protein product require the production of GTP from ATP in order to exert their effects within the cell. This implies that the activity of nucleoside diphosphate kinase (NDPK) plays a major role in the regulation of cellular events requiring GTP and that the level of activity of this enzyme is critical. This report presents a simple method for trapping a specific isozyme of NDPK in its high-energy phosphorylated form (NDPK approximately P) using EDTA and demonstrates that this NDPK approximately P is tenfold higher in malignant colon tumor tissue than in normal colon tissue. This autophosphorylation of the 21,000 and 24,000 Mr subunits of NDPK occurs rapidly at 0 degrees C, will use either [gamma-32P]ATP, [gamma-32P]GTP, or the corresponding 8-azidopurine photoprobes, is intramolecular, displays saturation effects, and is prevented from forming if GTP gamma S is added. Dephosphorylation in the homogenate occurs rapidly upon addition of Mg2+ or any nucleoside-5'-diphosphate. The subunits autophosphorylated in the homogenates are mostly in the soluble phase, and they comigrate with the subunits of pure NDPK from human erythrocytes. Cross-addition of normal and malignant homogenates does not decrease the level of autophosphorylation of NDPK, which indicates that the level of NDPK approximately P may be a quantitative measure of the level of this specific NDPK isozyme form. Assays for NDPK activity show correspondingly elevated levels in the malignant homogenates. Using western blot and photoaffinity labeling techniques, we distinguished the NDPK approximately P subunits from two closely migrating GTP-binding proteins. These were identified as the ras gene protein product and a 20,000 Mr protein, which comigrates identically with ADP-ribosylating factor (ARF). The ARF also comigrates in a tight band that is phosphorylated by [gamma 32P]ATP or [gamma-32P]GTP when Mg2+ is present.

Amino Acids↗
PubMed1989

Research note: parallel reactions in rape victims and rape researchers.

In a recent study, several nurse researchers assisted in a case record review on 1,215 rape crisis center records to determine demographic predicators of sexual abuse. Despite the relatively impersonal nature of the method used in collection of data, researchers experienced highly subjective responses to the often sketchy case records both during and after the study. Some of the reactions reported by data collectors included: anger, dreams, fear of physical injury, and sleep disorders. These responses closely parallel those reported in the literature on rape victims. This research note (1) describes the reactions of the five different data collectors, (2) compares these reactions to those reported for rape victims, (3) suggests some implications for those engaged in research on potentially distressing topics, and (4) offers suggestions on how to best prepare data collectors and others for research in emotionally charged areas.

Crisis Intervention↗
PubMed1988

Which blood pressure?

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Blood Pressure Determination↗
PubMed1988

AIDS in the U.S.S.R.

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Acquired Immunodeficiency Syndrome↗