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Biomedical subjects

C Morrow

Publications and source records attributed to C Morrow.

39 records · Page 3Linked to original sources

Production and purification of a recombinant elastomeric polypeptide, G-(VPGVG)19-VPGV, from Escherichia coli.

An elastomeric polypeptide was produced, with the sequence G-(VPGVG)19-VPGV, as a fusion to glutathione S-transferase using the vector pGEX-3X. The fusion protein was expressed to high levels in Escherichia coli as indicated by SDS-PAGE analysis of induced cells. The fusion protein was affinity purified and cleaved with protease factor Xa, and the elastomeric polypeptide was recovered to a high degree of purity as indicated by SDS-PAGE followed by staining with CuCl2. The physical characterizations of carbon-13 and proton nuclear magnetic resonance and of the temperature profile for turbidity formation for the inverse temperature transition of hydrophobic folding and assembly attest to the successful microbial synthesis of the polypentapeptide of elastin. The results of these studies provide the initial progress toward achieving a more economical and practical means of producing material for elastic protein-based polymer research and applications.

Amino Acid Sequence↗

Brief report: relationship between HIV infection and WPPSI-R performance in preschool-age children.

OBJECTIVE: To determine the neurodevelopmental effects of perinatally acquired HIV infection on children of preschool age. METHODS: Participants included 40 children infected with HIV between the ages of three and five and an equal number of noninfected controls individually matched according to ethnicity, age, sex, and prenatal drug exposure. Participants were administered the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R), upon which an analysis of subtest distribution was conducted. RESULTS: Whereas both groups evidenced mean IQ and subtest scores significantly below published norms, an effect for HIV group status was not found when a factor combining Performance IQ (PIQ) and Verbal IQ (VIQ) was analyzed. However, the group infected with HIV scored significantly lower than controls on the Block Design subtest. CONCLUSIONS: Gross cognitive deficits are not evident among preschool children infected with HIV relative to matched controls. However, this study does provides some evidence for more focal deficits. Further investigation with older children should be conducted.

Case-Control Studies↗

Effects of angiotensin II on canine and porcine coronary epicardial and resistance arteries.

Coronary resistance arteriolar diameter importantly regulates myocardial blood flow, and is influenced by circulating neurohumoral agents. Angiotensin II (A-II) is a circulating polypeptide that is chronically elevated in heart failure and serves as a potent peripheral vasoconstrictor agent. However, its effects on isolated coronary resistance arterioles is relatively unknown. We compared the vasomotor effects of A-II on coronary epicardial and resistance arterioles in vitro from both the canine and porcine heart in order to determine the effects of A-II in different vascular beds and species. Epicardial rings were studied under isometric recording conditions, while resistance arterioles (50-150 microns) were studied in vitro using a video imaging system to record diameter. A-II, whether applied to passively distended or preconstricted porcine resistance arterioles, did not cause vasoconstriction when applied as a bolus or as cumulative doses. In preconstricted canine resistance arterioles, A-II elicited dose-dependent vasodilation (EC50 = 0.2 nM). In passively distended canine arterioles, high concentrations of A-II (0.1 microM) applied as a bolus elicited transient vasoconstriction in 28% of the vessels studied. In large epicardial rings, A-II was a weak vasoconstrictor, with greater potency in canine arteries compared to porcine arteries. In canine arteries, vasoconstriction to A-II was augmented after incubation with indomethacin. In contrast to the findings in canine arteries, the A-II vasoconstrictor response in porcine coronary arteries was decreased after incubation with indomethacin or removal of the endothelium. Thus, A-II elicits the release of a vasodilator prostanoid in epicardial canine coronary arteries and a vasoconstrictor prostanoid in porcine vessels which modulate the vasomotor action of A-II.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗