Publications by authors named "W S Stirewalt"

Objective: To determine if nonpregnant plasma volume is altered in women who are homozygous for the T 235 coding angiotensinogen allele, which predisposes women to an increased risk of preeclampsia.

Methods: We measured plasma volume by Evans blue dilution and analyzed it as a function of angiotensinogen genotype in 15 nulligravid women during midfollicular phase of 26 menstrual cycles. Eleven women were evaluated during two cycles, and four women were evaluated in one cycle.

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Objective: To test the hypothesis that an elevated amniotic fluid glycine-valine ratio predicts neonatal morbidity in growth-restricted newborns.

Methods: Amniotic fluid (AF) was collected from 122 third-trimester pregnancies (range 31-39 weeks), 49 of which were complicated by fetal growth restriction. Amino acid analysis was performed by high-pressure liquid chromatography.

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The cellular basis of adaptations occurring during the development of megacolon was studied with the lethal spotted mouse model. Age-dependent changes in the length-force characteristics of the colon reach a steady state by 3-4 mo and include an increased relative force development at very short muscle lengths. In megacolon the following occur: 1) structural remodeling expressed as a greater increase in the fraction of maximum force production at short lengths, a shift of optimum length (Lo) to longer lengths, and no change in force per square centimeter; 2) hypertrophy and hyperplasia of both circular and longitudinal muscle; 3) high resting compliance consistent with no disproportionate change in collagen or elastin composition; 4) marked distension so that in situ circumference approximately 1.

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The effects of estrogen and progesterone on the expression of epidermal growth factor receptor (EGFR) in human endometrium were studied in hypogonadal women under conditions that simulated a normal menstrual cycle. All women received the same regimen of estrogen and progesterone and underwent serial biopsies. In one group of women (group I), a biopsy was obtained before receiving estrogen (CD0) and after 11 days (CD11) of estrogen replacement.

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This study was designed to characterize the hemodynamic and biochemical properties of the abdominal aorta in four genetically related inbred rat strains that express genetic hypertension and hyperactive behavior in varying combinations. These include (1) the spontaneously hypertensive rat (SHR), which is hypertensive, hyperactive, and hyperreactive to stress; (2) Wistar-Kyoto (WKY) rats, which express none of these traits; (3) WKHT rats, which are hypertensive but not hyperactive; and (4) WKHA rats, which are hyperactive and hyperreactive to stress, but normotensive. Together, these four strains allowed us to examine the structural and functional changes in the aorta in the hypertensive SHR, the most widely used animal model of genetic hypertension, while controlling for the variables of hyperactivity and hyperreactivity that are also expressed in the SHR.

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