Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

Peer reviewe

Mencari Bakat Anak-anak

84 hlm.;21 c

Normal breast tissue implanted into athymic nude mice identifies biomarkers of the effects of human pregnancy levels of estrogen

We have generated a novel model system for the study of estrogen intervention in normal breast tissue. Nulliparous human breast tissue was implanted into immunocompromised nude mice and treated with high-dose estrogen to simulate the effects of pregnancy. Treatment of mice with human mid-pregnancy levels of 17β-estradiol for a period of 4 weeks was followed by 4 weeks of withdrawal to mimic involution. Gene expression in the xenograft tissue was then analyzed by real-time reverse transcription-PCR to identify differences between treated and control tissues. Ten genes previously identified as altered by pregnancy in rodent models were found to be differentially expressed in human breast tissue with a ≥1.8-fold up-regulation of CDC42, TGFβ 3, DCN, KRT14, LTF, and AREG and a ≥0.7-fold down-regulation of STAT1, CTGF, IGF1, and VAMP1. Immunohistochemical analysis of archival paraffin-embedded adult premenopausal human breast tissue specimens identified a significantly lower level of expression of STAT1 (P <0.05, Mann-Whitney U test) in parous compared with age-matched nulliparous tissue (median of 24% compared with 42% epithelial cells positive). We conclude that many of the pregnancy-induced breast cancer-protective changes observed in rodent models also occur in human breast tissue following intervention using human pregnancy levels of estrogen and that STAT1 expression is a potential biomarker of parity-induced breast cancer protection in the human breast. ©2009 American Association for Cancer Research

Geology of the Bach quadrangle (H15), Mercury

Mercury’s Bach quadrangle (H15) is the areapoleward of 65 °S. We mapped this geologically using remote sensing-basedobservations of surface morphology revealed on MESSENGER data products. Thismap contributes to a series of quadrangle maps providing geological context forthe ESA-JAXA BepiColombo mission to Mercury. We performed digitisation at ∼1:400,000scale and final publication scale is 1:3,000,000. There are four morphologicallydistinct plains units: intercrater, intermediate, smooth, and very smooth.Impact craters cover much of H15’s surface. Following convention, we mappedcrater materials for all craters ≥20 km, classifying them on the basis ofmorphological evidence for degradation. We produced two map versions, using athree-class and a five-class crater degradation scheme. We include twogeological aspects that have not featured in previous maps of the series, bymapping occurrences of lobate ejecta at craters ≥20 km and depicting thedistribution of the south polar permanently shadowed regions