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Biomedical subjects

K Cox

Publications and source records attributed to K Cox.

At least 145 records · Page 8Linked to original sources
PubMed1987

Cloning genes for the biosynthesis of a macrolide antibiotic.

Macrocin-O-methyltransferase (MacOMeTase) catalyzes the final enzymatic step in the biosynthesis of tylosin in Streptomyces fradiae. A 44-base mixed oligonucleotide probe containing only guanosine and cytidine in the third position of degenerate codons was synthesized based on the amino acid sequence of the amino terminus of MacOMeTase. Plaque blot hybridization to a bacteriophage lambda library and colony blot hybridization to a cosmid library of S. fradiae DNA identified recombinants that contained overlapping fragments of chromosomal DNA. The nucleotide sequence of the cloned DNA verified that the DNA contained the coding sequence for MacOMeTase. Recombinant plasmids transformed mutants blocked in tylosin biosynthesis and complemented tylF (the structural gene for MacOMeTase) and tyl mutations of eight other classes.

Cloning, Molecular↗
PubMed1986

The relationship between abortion in the first pregnancy and development of pregnancy-induced hypertension in the subsequent pregnancy.

The relation between pregnancy-induced hypertension and reproductive history was assessed in 29,484 women receiving obstetric care at Parkland Memorial Hospital. The incidence of pregnancy-induced hypertension was 25.4% in primigravid women, somewhat lower (22.3%) in women whose only previous pregnancy terminated in abortion, and much lower (10%) in women who carried two or more successive pregnancies to viability.

Abortion, Induced↗
PubMed1986

Cervical dilatation and prematurity revisited.

Cervical examination between 26 and 30 weeks' gestation is described as a method for identifying women at risk for delivery before 34 weeks. Blinded cervical examinations were performed in 185 consecutive women, and 15 (8%) were found to have cervixes dilated 2 or 3 cm. The incidence of delivery before 34 weeks' gestation was 27% in such women compared with 2% in those whose cervixes were undilated or 1 cm. Other factors linked to cervical dilatation included parity and prior preterm delivery. However, parous women with cervical dilatation remained at increased risk for delivery before 34 weeks' gestation. We conclude that early third-trimester cervical examination may be an important adjunct in identifying women at risk for preterm delivery.

Birth Weight↗
PubMed1985

Simultaneous expression of early and late histone messenger RNAs in individual cells during development of the sea urchin embryo.

The transition from early (E) to late (L) histone gene expression in developing sea urchin (Strongylocentrotus purpuratus) embryos was examined for H2B, H3, and H4 mRNAs by in situ hybridization of class-specific probes. Hybridization patterns indicate that the shift from E to L mRNAs occurs gradually and simultaneously in all blastomeres. Thus, during the transition the ratio of L to E mRNAs is similar in most cells. This suggests that no sudden changes in histone composition occur in individual cells which might be related to alterations in gene expression associated with differentiation of cell lineages. Around the midpoint of the transition, clusters of cells progressively appear which contain little, if any, E or L histone mRNA. This modulation of expression is coordinated for the three late genes examined because most individual cells contain either high or low levels of all three mRNAs. At blastula stage these clusters of unlabeled cells appear to be randomly distributed throughout the embryo. Subsequently the unlabeled regions expand and are found predominantly in aboral ectoderm as these cells cease to divide. Thus, the L/E histone mRNA ratio is not differentially regulated in diverse cell lineages, and the major differences in total histone mRNA content among individual cells may be related to cell cycle and/or the cessation of division.

Animals↗
PubMed1985

Amebiasis presenting as rectal bleeding without diarrhea in childhood.

A 6-year-old boy with no history of foreign travel had presented with rectal bleeding without diarrhea for 2 months. Despite negative stool cultures, a diagnosis of intestinal amebiasis was made by colonoscopy with tissue biopsy. In cases of persistent rectal bleeding, even without diarrhea, a diagnosis of amebiasis should be considered. When routine stool parasite examinations are negative, unsuspected amebiasis may be diagnosed by sigmoidoscopy or colonoscopy with tissue biopsy.

Biopsy↗
PubMed1984

Plasma prostaglandins during the intravenous infusion of angiotensin II in pregnant women.

The possible relation between prostaglandin production and the sensitivity of pregnant women with pregnancy-induced hypertension to the pressor effects of angiotensin II was investigated. Plasma prostaglandin levels were determined in four groups of women before, during, and after intravenous infusion of angiotensin II. Concentrations of the stable metabolites of prostaglandin E2, prostaglandin F2 alpha, and prostaglandin I2 (prostacyclin) were quantified by specific radioimmunoassays in the plasma of nonpregnant women, women pregnant in the late third trimester, and women pregnant in the late third trimester with either pregnancy-induced or chronic hypertension. Plasma prostaglandin concentrations did not change significantly during angiotensin II infusion in any of the four groups of women. Levels of the prostacyclin metabolite, however, were significantly higher in the hypertensive pregnant women than in the normotensive pregnant women.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

Decision making in professional associations.

Processes for decision making by large groups such as professional associations have not adapted rapidly to the growing complexity of the situations those associations face. This paper describes a ten-step procedure which has enabled professional bodies to engage a large sample of their constituency in extensive planning exercises. These planning workshops addressed a wide range of complex issues, many of which were sensitive and threatening. The steps comprised identifying the problems, collating the agenda, analysis of the issues raised, deriving a structured sequence of tasks, pre-circulating papers, forming working groups, providing adequate time and facilities in a suitable setting for effective workshop activity, ensuring communication among groups within the workshop, managing the plenary reporting and consensus seeking, plus recording and circulating the report back to members. Groups worked cooperatively and constructively without evidence of intragroup competition, which reflects both the homogeneity of purpose within those professions and the effect of strong task structuring.

Communication↗
PubMed1984

Prostaglandin synthase inhibitory activity in plasma of women with dysmenorrhea.

Prostaglandins have been implicated in the etiology of dysmenorrhea, and plasma levels of prostaglandin F metabolite are increased in women during dysmenorrhea episodes. We determined the prostaglandin synthase inhibitory activity of plasma obtained from the blood of women who experience moderate to severe dysmenorrhea. Blood was obtained at the onset of dysmenorrhea ("symptomatic") and during the late follicular phase of the ovarian cycle ("asymptomatic"). Prostaglandin synthase inhibitory activity in all samples was comparable to that previously found in adult women, and we found no difference in activity between the paired plasma samples, those obtained during symptomatic and asymptomatic times. Protein denaturation of the plasma by boiling also did not produce differences in prostaglandin synthase inhibition.

Adult↗
PubMed1983

Pressor responsiveness to angiotensin II in hospitalized primigravid women with pregnancy-induced hypertension.

Hospitalization of women with pregnancy-induced hypertension is beneficial in improving pregnancy outcome, but how it affects this physiologic process is not clear. In the present investigation, we evaluated pressor responsiveness to angiotensin II in 62 hospitalized women with pregnancy-induced hypertension. Although each of the women became normotensive, at least transiently, all remained sensitive to the pressor effects of angiotensin II. Thus, the beneficial effect of hospitalization on women with pregnancy-induced hypertension cannot be attributed to a decrease in the responsiveness to the action of angiotensin II.

Angiotensin II↗