Assuming the limitations inherent to clinical assessment, this study shows a notably weaker association of abacavir with lipoatrophy than stavudine. DEXA scans and anthropometric measurements supported the clinical findings. In addition, the lipid changes that occurred were more favorable in patients receiving abacavir.

This work was supported by Consejo Nacional de Investigaciones Científicas y Técnicas [PIP0 496 to S.P.-M.], Agencia Nacional de Promoción Científica y Tecológica [PICT 2012-1195 and PICT2014-2325 to S.P.-M., and PICT 2013-2050 to C.D.], Boehringer Ingelheim Funds, and the Swedish Farmers Foundation [SLF-H13300339 to J.M.]. The authors declare there are no conflicts of interests.

During the passage of sperm through the oviduct, spermatozoa bind to the oviductal epithelium and form the oviductal reservoir. This interaction keeps the fertilizing capacity of sperm until ovulation-associated signals induce sperm release from the oviductal epithelium, allowing the transit of spermatozoa to the fertilization site. Fibronectin is a glycoprotein from the extracellular matrix that binds to α5β1 receptors. Fibronectin has been found to be expressed in the oviduct, whereas α5β1 has been found to be expressed in the sperm of different species. Fibronectin is involved through α5β1 in sperm functions. The aim of this work was to study the participation of oviductal fibronectin in the regulation of the sperm-oviduct interaction in cattle. We found that oviductal epithelial cells differentially expressed all mRNA splice variants of fibronectin during the estrous cycle. Fibronectin was localized in the apical region of oviductal epithelial cells and fibronectin levels in the oviductal fluid fluctuated during the estrous cycle. Also, bovine spermatozoa expressed α5β1. Using in vitro sperm-oviduct co-cultures, we found that spermatozoa were attached to the oviductal epithelium through α5β1. The incubation of co-cultures with fibronectin induced sperm release from the oviductal cells through α5β1. The sperm population released from oviductal cells by fibronectin was enriched in motile and capacitated spermatozoa. Based on our in vitro culture system results, we propose that fibronectin and α5β1 are involved in the sperm-oviduct interaction. Also, an increase in fibronectin levels in the oviductal fluid during the pre-ovulatory period may promote sperm release from the oviductal epithelium in cattle. J. Cell. Biochem. 118: 4095-4108, 2017. © 2017 Wiley Periodicals, Inc.

In order to test the validity of a previously advanced hypothesis, that the human foetus actively participates in the oestrogen metabolism of pregnancy attempts were made to introduce different oestrogens into the foetal organism prior to surgical interruption of gestation. Intravenous infusion into the mother of as much as 100 mg of oestriol (oestra-1,3,5(10)-triene-3,16α,17β-triol) resulted in no rise at all in the oestriol concentration of amniotic fluid and only in an extremely limited increase in the conjugated oestriol content of the foetal lungs and livers. It was found that intra-amniotic injection is a most effective way of introducing oestrogen into the foetal organism, since the oestrogen injected is rapidly swallowed (perhaps also aspirated) by the foetus. The administration of 25 mg amounts of 17β-oestradiol (oestra-1,3,5(10)-triene-3,17β-diol) or oestriol by this route resulted in a greatly elevated concentration of conjugated oestrone (3-hydroxy-oestra-1,3,5(10)-triene-17-one) + oestradiol and oestriol, respectively, in a variety of foetal organs, such as the lungs, liver, intestines, and adrenals + kidneys. Especially the lungs seemed to represent a very active site of conjugation, whereas the increase in conjugated oestrogens in the placenta was very limited. Intra-amniotically administered 17β-oestradiol or oestriol rapidly disappeared from the amniotic fluid; it was halved in less than 2 hours and disappeared within 24 hours.