Estrogen plus progestin does not confer cardiac protection and may increase the risk of CHD among generally healthy postmenopausal women, especially during the first year after the initiation of hormone use. This treatment should not be prescribed for the prevention of cardiovascular disease.
CRC is a common disease responsible for an estimated 52,000 deaths in the United States in 2007. In about 3% of newly diagnosed CRC, the underlying cause is a mutation in a MMR gene (Lynch syndrome) that can be reliably identified with existing laboratory tests. Relatives inheriting the mutation have a high (about 45% by age 70) risk of developing CRC. Evidence suggests these relatives will often accept testing and increased surveillance.
While the potential of Internet-based qualitative research methods is substantial, such methods are not without their problems. Some of these methodological challenges are unique to the medium, while others are similar to those of more traditional qualitative methods. This article presents some of these methodological challenges, and explores some of the issues involved in using on-line discussion boards as virtual focus groups in a study of perimenopausal women with migraines. Design of the study and its advantages and disadvantages are discussed, including the role of the moderator. Some of the problems encountered included potential for misunderstandings due to limits of written communications, and difficulty encouraging participation.
Suppression of cell-mediated immunity has been proposed as a mechanism that promotes maternal tolerance of the fetus but also contributes to increased occurrence and severity of certain infections during pregnancy. Despite decades of research examining the effect of pregnancy on Ag-specific T cell responses, many questions remain. In particular, quantitative examination of memory CD8 T cell generation following infection during pregnancy remains largely unknown. To examine this issue, we evaluated the generation of protective immunity following infection during pregnancy with a nonpersistent strain of lymphocytic choriomeningitis virus (LCMV) in mice. The CD8 T cell response to LCMV occurred normally in pregnant mice compared with the nonpregnant cohort with rapid viral clearance in all tissues tested except for the placenta. Despite significant infiltration of CD8 T cells to the maternal-fetal interface, virus persisted in the placenta until delivery. Live pups were not infected and generated normal primary immune responses when challenged as adults. Memory CD8 T cell development in mice that were pregnant during primary infection was normal with regards to the proliferative capacity, number of Ag-specific cells, cytokine production upon re-stimulation, and the ability to protect from re-infection. These data suggest that virus-specific adaptive memory is normally generated in mice during pregnancy.
Background
Recent evidence suggests that antecedent packed red blood cell (PRBC) transfusions increase the risk for necrotizing enterocolitis (NEC), the most common gastrointestinal emergency encountered by very low birth weight (VLBW) infants. The underlying mechanism for this association is unknown. Altered oxygenation of the mesenteric vasculature during PRBC transfusion has been hypothesized to contribute to NEC development and was investigated in this study.
Study design and methods
Oxygenation patterns among four VLBW infants who developed transfusion-related NEC (TR-NEC) were compared to four VLBW infants with similar gestational age who were transfused but did not develop NEC (non-NEC). Cerebral and mesenteric patterns were recorded before, during and 48 hours subsequent to PRBC transfusion using near-infrared spectroscopy technology (NIRS). Percentage change from mean baseline regional saturation (rSO2) values and cerebro- splanchnic oxygenation ratio (CSOR) were analyzed.
Results
All TR-NEC infants (24–29 weeks gestation; 705–1080 grams) demonstrated greater variation in mesenteric oxygenation patterns surrounding transfusions than non-NEC infants (27.6–30 weeks gestation; 980–1210 grams). TR-NEC infants received larger mean volumes of total blood (27.75 ml/kg ± 8.77) than non-NEC infants (15.25ml/kg ± 0.5).
Conclusion
Wide fluctuation and decreases in mesenteric oxygenation patterns are more pronounced in TR-NEC infants, especially prior to TR-NEC onset, as compared to non-NEC infants. Greater total volume of infused blood was associated with TR-NEC in preterm infants. Using NIRS, larger prospective studies are needed to further evaluate potential risk factors for NEC in this high risk population.
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