Biomedical subjects

M E Lantz

Publications and source records attributed to M E Lantz.

5 recordsLinked to original sources

PubMed1998

The induction of cyclooxygenase-2 by interleukin-4 in human umbilical vein endothelial cells: a possible role in regulation of fetal vascular tone.

OBJECTIVE: We sought to determine a possible role for interleukin-4 in the control of umbilical cord blood flow by evaluating its effect on cyclooxygenase-2 production of a vasoactive prostaglandin. STUDY DESIGN: Human umbilical vein endothelial cells in culture were incubated for 16 hours in media containing interleukin-4 in concentrations from 5 to 100 ng/ml. Prostaglandin E2 concentrations in the culture media were measured using a monoclonal enzyme-immunoassay. Concentrations of cyclooxygenase-1 and cyclooxygenase-2 were determined by Western blot analysis on cell homogenates. Statistical comparisons between prostaglandin E2, cyclooxygenase-1, and cyclooxygenase-2 concentrations for each interleukin-4 concentration were performed using a one way analysis of variance. RESULTS: Incubation of human umbilical vein endothelial cells in media containing interleukin-4 resulted in a significant increase in both prostaglandin E2 and cyclooxygenase-2 for interleukin-4 concentrations greater than 50 ng/ml (p < 0.05). Cyclooxygenase-1 levels were not affected. CONCLUSIONS: We suggest that interleukin-4 may have a role in the regulation of umbilical blood flow mediated through the induction of cyclooxygenase-2.

Blotting, Western↗

PubMed1996

Maternal weight gain patterns and birth weight outcome in twin gestation.

OBJECTIVE: To evaluate the association between maternal weight gain patterns, based on pregravid body mass index (BMI) and birth weight outcome in twins, and to make specific recommendations for maternal weight gain during twin gestation. METHODS: One hundred eighty-nine twin pregnancies were reviewed retrospectively. Weekly rates of maternal weight gain before 20 weeks, from 20 weeks to delivery, and for total gestation were calculated. Thresholds of weekly maternal weight gain were determined for underweight and normal-weight women. RESULTS: In underweight women, a higher weekly rate of gain before 20 weeks was associated with the birth of both twins weighing at least 2500 g (1.13 versus 0.70 lb/week, P = .017), when compared with mothers of at least one twin weighing less than 2500 g. A higher rate of weight gain from 20 weeks to delivery was associated with the delivery of twins weighing at least 2500 g in both underweight (1.92 versus 1.29 lb/week, P = .031) and normal weight (1.63 versus 1.29 lb/week, P = .046) women. No significant differences in weight gain patterns were found between overweight women delivering twins weighing less than 2500 g or at least 2500 g. A weekly rate of gain from 20 weeks' gestation to delivery of at least 1.75 lb/week in underweight women and at least 1.50 lb/week in normal-weight women was associated with the birth of both twins weighing at least 2500 g. After controlling for other potential determinants of birth weight, the threshold of 1.75 lb/week in underweight women showed a trend toward significance as an independent predictor of both twins weighing at least 2500 g (P = .06). CONCLUSION: Certain maternal weight gain patterns during twin pregnancy are associated with the birth of each twin weighing at least 2500 g. As with singletons, recommendations for maternal weight gain during twin pregnancy can be based on pregravid BMI.

Adult↗

PubMed1996

The induction of cyclooxygenase-2 (COX-2) in intact human amnion tissue by interleukin-4.

Infection is a major cause of preterm labor. Amniotic fluid from women in preterm labor associated with intrauterine infection contains increased concentrations of cytokines. The mechanism underlying this association may be a cytokine-mediated stimulation of amnion cell prostaglandin production. The biosynthesis of prostaglandins from arachidonic acid is regulated by the enzyme cyclooxygenase which exists in two forms; the constitutive form (COX-1) and the other mitogen inducible (COX-2). The purpose of this study was to evaluate the effect of the cytokine interleukin-4 (IL-4) on cyclooxygenase activity and PGE2 production in amnion. Amnion tissue was taken at caesarean section from term women not in labor and immediately incubated for 2 hours in media containing concentrations of IL-4 ranging from 1 to 100 ng/ml. An increase in both COX-2 enzyme and prostaglandin E2 (PGE2) production was observed for all concentrations of IL-4 greater than 25 ng/ml (P < 0.05, n = 8). No change in COX-1 was observed. Our data suggest that the cytokine IL-4 may be involved in the pathogenesis of premature labor by inducing COX-2 in amnion tissue resulting in increased production of PGE2 and subsequent myometrial activity.

Amnion↗

PubMed1995

The effect of sample preparation and storage on maternal triple-marker screening.

OBJECTIVE: To evaluate the effect of different sample collection, storage, and preparation techniques on serum alpha-fetoprotein (AFP), beta-hCG, and unconjugated estriol (E3) concentrations. METHODS: A solution containing known concentrations of AFP, hCG, and unconjugated E3 was diluted in blood samples obtained from seven healthy male volunteers. Serum from each blood sample was removed immediately, and either assayed or frozen at -70C. Portions of the remaining blood were handled as follows: centrifuged and refrigerated, centrifuged and left at room temperature, not centrifuged and refrigerated, or not centrifuged and left at room temperature. Serum was removed from these samples for triple-marker analysis at 24, 48, 96, and 168 hours after the initial sample collection. RESULTS: Immediate freezing of serum and subsequent thawing resulted in a significant increase in beta-hCG and unconjugated E3 levels, but no change in AFP levels. There was a significant effect over time on AFP, hCG, and unconjugated E3 concentrations. The change in AFP levels was influenced by centrifugation status, whereas all three analytes were influenced by refrigeration status. CONCLUSION: Different sample collection, storage, and preparation techniques may affect maternal triple-marker screening.

Chorionic Gonadotropin↗

PubMed1993

Multiple pregnancy.

The incidence of multiple gestations has increased markedly over the past decade. This review will focus on new interventions and techniques such as selective fetal reduction, optimizing maternal weight gain, bed rest, home uterine monitoring, ultrasound, and Doppler velocimetry, which have been employed to improve outcomes in these pregnancies.

Abortion, Therapeutic↗