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Biomedical subjects

D R Powell

Publications and source records attributed to D R Powell.

121 records · Page 7Linked to original sources
PubMedDate not supplied

HIV seropositivity as a major risk factor for suicide in the general hospital.

The purpose of this study was to assess the suicide rate in people infected with the human immunodeficiency virus (HIV) in the general hospital population. A retrospective study of 2,363 psychiatric consultations was done in 1989 and 1990 at an urban municipal teaching hospital in New York City. The sample included 2,363 patients admitted to adult general care from January 1, 1989, to December 31, 1990, for whom consultations were requested from the consultation-liaison psychiatry service. Suicidal behavior was the reason for consultation in 21.8% of HIV-positive persons and in 19.8% of persons with acquired immunodeficiency syndrome. It was the reason for consultation in only 13.9% of persons with unknown HIV serostatus. This difference is statistically significant. The authors conclude that HIV seropositivity may be a significant risk factor for suicide in the general hospital patient population.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

The heparin binding domain of insulin-like growth factor binding protein (IGFBP)-3 increases susceptibility of IGFBP-3 to proteolysis.

IGFBP-3 proteolysis clears IGFBP-3 from body fluids and increases IGF bioavailability. As shown here, native human IGFBP-3 was cleaved by proteases in media conditioned by hamster and insect cells. This proteolysis was less pronounced for IGFBP-3 containing a mutated heparin binding domain, and was prevented by purifying IGFBP-3 on an IGF-I affinity column in the presence of 2 M sodium chloride, suggesting that the responsible protease(s) binds the IGFBP-3 heparin binding domain. To determine if any human proteases act this way, we first studied plasma prekallikrein since it can copurify with IGFBP-3, and found: 1) [125]IGFBP-3 binds to prekallikrein immobilized either on nitrocellulose or on immunocapture plates; 2) the IGFBP-3 heparin binding domain participates in forming the IGFBP-3/prekallikrein complex; 3) the binary IGFBP-3/prekallikrein complex can bind IGF-I to form a ternary complex; and 4) activation of prekallikrein to alpha-kallikrein by Factor XIIa resulted in proteolysis of bound IGFBP-3. This work suggests: 1) cleavage of IGFBP-3 by a protease may be aided by the ability of the protease zymogen to directly bind the IGFBP-3 heparin binding domain; and 2) direct binding of protease zymogens to IGFBP-3 may explain some instances where IGFBP-3 is preferentially proteolyzed in the presence of other IGFBPs.

Amino Acid Sequence↗
PubMedDate not supplied

The effect of repeated doses of succinylcholine on serum potsssium in patients with renal failure.

The effect of 1 mg/kg of succinylcholine IV in repeated doses on serum potassium (K+) was studied in 11 patients with renal failure. Increases in K+ did not differ from those seen in patients with normal kidney function, the largest increase being 0.6 mEq/L. The authors conclude that succinylcholine administered repeatedly at this dosage is not contraindicated in patients with renal failure.

Adolescent↗
PubMedDate not supplied

Hypo- and hyperdiploidy in cultured amniocytes.

2,340 metaphases of amniocytes from 149 karyotypically normal women were analyzed for hypo- and hyperdiploidy. Hypodiploidy was more frequent than hyperdiploidy. Chromosome loss was correlated with size. The smaller chromosomes are lost more frequently (r = 0.62 p less than 0.05) than the larger ones. Considering the inconclusive findings of lymphocyte cultures, one can conclude that the hypodiploid cells arose as technical artifacts while hyperdiploidy may be due to somatic non-disjunction owing to pseudomosaicism.

Adult↗