Sidestream Dark Field Imaging of the Microcirculation to Assess Preeclampsia Microvascular Dysfunction.

BACKGROUND: Development of predictive models of preeclampsia has only yielded modest results. We hypothesized that impaired indices of microcirculatory function could be detected using sidestream dark field imaging. The objective of this study was to examine microvascular function in women at high risk for preeclampsia at mid-gestation. METHODS: Women between 16 and 22 weeks of gestation were screened for eligibility. Patients were recruited if they met eligibility criteria indicating high risk for preeclampsia. Investigators performed non-invasive sidestream dark field imaging of the sublingual microcirculation. Images were analyzed to determine microcirculatory parameters (microvascular flow index, perfused vessel density, total vessel density, and proportion of perfused vessels). After delivery, charts were reviewed to determine if they developed gestational hypertension, preeclampsia or severe preeclampsia. RESULTS: Twelve of 66 participants (18.2%) developed preeclampsia or severe preeclampsia during the course of their pregnancy. Microvascular flow index was not significantly different between participants with normal pregnancies and participants with preeclampsia or severe preeclampsia (2.75 ± 0.38 vs. 2.80 ± 0.34, respectively; P = 0.459). Similarly, there were no significant differences between groups in the remaining microcirculatory parameters. CONCLUSIONS: Sidestream dark field imaging of the sublingual microcirculation may remain an appropriate tool to identify women at risk for preeclampsia, albeit later in pregnancy.

Oral p-tert-octylphenol exposures induce minimal toxic or estrogenic effects in adult female Sprague-Dawley rats.

Contamination of the environment with endocrine-disrupting chemicals (EDC) has raised concerns about potential health hazards for humans and wildlife. Human and wildlife exposure to one such ubiquitous chemical, p-tert-octylphenol (OP), are likely, due to its persistence in the environment and its presence in food, water, and items of daily use. OP is reported to bind to the estrogen receptor (ER) and alter expression of estrogen-responsive genes. Detrimental effects of OP exposures on the reproductive system have been observed in most, but not all, in vivo experiments. This study examined estrogenic effects of oral exposures of adult female rats to OP. In vitro, OP bound weakly to human ER and a co-activator protein, and accelerated proliferation of MCF-7 cells. Adult Sprague-Dawley rats were given OP by gavage daily for 35 d (25, 50, or 125 mg/kg/d). Body and organ weights and ovarian follicle populations were not significantly altered in OP-exposed adult rats, despite detectable levels of OP in reproductive organs. The estrous cycle of rats was slightly altered, but there were no significant estrogen-like changes in histomorphology or gene expression of the uterus. Prepubertal rats given 125 or 250 mg/kg OP by gavage for 3 d had reduced body weight compared to vehicle-exposed rats but failed to show any uterotrophic response, although 17alpha-ethinyl estradiol (EE, 10 microg/kg/d, ip) induced a threefold increase in uterine weight. Overall, results suggest that toxicity will occur before estrogenic effects with oral exposures to OP. Relevant environmental exposures likely pose little risk for estrogenic effects.

Amino Acid transport mechanisms in mouse oocytes during growth and meiotic maturation.

Amino acids are transported into cells by a number of different transport systems, each with their own specific range of substrates. The amino acid transport systems active in preimplantation embryos and the amino acids required by embryos for optimal development have been extensively investigated. Much less is known about amino acid transport systems active in growing and meiotically maturing oocytes or about developmental changes in their activity. As a first step in determining the array of amino acid transporters active in oocytes, the transport characteristics of nine amino acids were measured in small, medium, and large growing oocytes; in fully grown germinal vesicle (GV)-stage oocytes; in metaphase I oocytes; and in metaphase II eggs. Whether each of 11 classically defined amino acid transport systems was likely active in oocytes at each stage was determined using assays based on measuring the transport of radiolabeled amino acids into oocytes and the effect of a limited set of potential competitive inhibitors. Six amino acid transport systems were found to be active during oocyte growth or maturation. L, b(0,+), and ASC/asc were active throughout oocyte growth and maturation, increasing during growth. In contrast, GLY, beta, and x(c)(-) had little or no activity during growth but became activated during meiotic maturation. Surprisingly, the presence of follicular cells surrounding medium growing oocytes or cumulus cells surrounding GV oocytes did not confer amino acid transport by additional transport systems not present in the oocyte. In some cases, however, follicular cells coupled to the oocyte enhanced uptake of amino acids by the same systems present in the oocyte.