We have recently reported that oocyte-derived bone morphogenetic protein-15 (BMP-15) can directly modulate follicle-stimulating hormone (FSH) action in rat granulosa cells. Here, we investigate underlying mechanisms of this BMP-15 effect. Treatment with BMP-15 alone exerted no significant effect on the basal expression of mRNAs encoding steroidogenic acute regulatory protein, P450 side chain cleavage enzyme, P450 aromatase, 3-hydroxysteroid dehydrogenase, luteinization hormone receptor, and inhibin/activin subunits. However, BMP-15 markedly inhibited the FSH-induced increases in these messages. In striking contrast, BMP-15 did not change the forskolin-induced levels of these transcripts. Thus, the inhibitory effect of BMP-15 on FSH action must be upstream of cAMP signaling. We next examined changes in FSH receptor mRNA expression. Interestingly, BMP-15 severely reduced the levels of FSH receptor mRNA in both basal and FSH-stimulated cells. To determine whether this effect was at the level of FSH function, we investigated the effect of BMP-15 on FSH bioactivity. Consistent with the mRNA data, BMP-15 inhibited the biological response of FSH, but not that of forskolin. Based on these results, we propose that BMP-15 is an important determinant of FSH action through its ability to inhibit FSH receptor expression. Because FSH plays an essential role in follicle growth and development, our findings could have new implications for understanding how oocyte growth factors contribute to folliculogenesis.
Rehabilitative water-walking exercise could be designed to incorporate large-muscle activities, especially of the lower-limb extensor muscles, through full joint range of motion and minimization of joint moments.
Xenotransplantation of porcine organs carries the risk of reactivation of latent virus in donor and recipient tissues as well as transmission of viruses between species. We have investigated the activation of baboon cytomegalovirus (BCMV) and porcine CMV (PCMV) in a pig-to-primate model of xenotransplantation. Tissues originating from a series of six swine-to-baboon composite thymokidney xenotransplants were investigated. Four immunosuppressed baboons died (survival range, 7 to 27 days) with the graft in situ. Increases in BCMV DNA copy numbers occurred in three (75%) of these baboons and was thought to be responsible for pneumonitis and the death of one animal. In two baboons, disseminated intravascular coagulation was successfully treated by graftectomy and discontinuation of immunosuppression. PCMV was upregulated in five of six xenografts (83%). PCMV infection was associated with ureteric necrosis in one xenograft. Although significantly increased in native tissues, low levels of BCMV and PCMV were also detected in tissues other than that of the native viral host species. The cross-species presence of CMV did not appear to cause clinical or histological signs of invasive disease. Thus, viral infections with clinical disease were restricted to tissues of the native species of each virus. Intensive immune suppression currently required for xenotransplantation results in a significant risk of reactivation of latent infections by BCMV and PCMV. It is not yet known whether viral DNA detected across species lines represents cellular microchimerism, ongoing viral infection, or uptake of free virus. The observation of graft injury by PCMV demonstrates that CMV will be an important pathogen in immunosuppressed xenograft recipients. Strategies must be developed to exclude CMV from porcine organ donors.
Kommerell's diverticulum can be repaired safely with graft replacement concomitant with in situ reconstruction of the aberrant subclavian artery through thoracotomy.
The photolysis of pyruvic acid vapour has been studied at wavelengths of 366, 345, and 320 nm, at a temperature of 340 K and pressures from about I to 10 Torr. Products observed were COZ and CH3CH0, with the former always in excess, and a quantum yield of COr of 0.9 ? 0. I at 366 nm. Light emission was also observed, and from the effect of added 0, it was concluded that emission occurred from both singlet and triplet states. It is suggested that the primary process in the photolysis is an internal hydrogen-atom transfer followed by dissociation into COz and CH,-C-OH, with the latter then rearranging to give CH3CH0 and other products.The absorption spectrum is reported; the first system begins at about 380 nm, rising to a maximum at about 350 nm, with E,,,,, --10 M-' cm-I, and is attributed to the first excited n* + n+ singlet state. Weak absorption below 300 nm is probably due to the n* + n-state and much stronger absorption below 220 nm to the n* + n state. The thermal decomposition was studied briefly at temperatures from 455 to 584 K and pressures from about 0.8 to 7 Tom. Products were the same as in the photolysis, and Arrhenius parameters of log A (s-I) = 7.19 and E = 27.7 kcal/mol were obtained, based on the formation of COr, which was apparently a simple, homogeneous unimolecular process.S. YAMAMOTO et R. A. BACK. Can. J. Chem. 63, 549 (1985). Optirant a des tempkratures allant de 455 a 584 K et a des pressions allant de 0,8 a 7 Torr, on a britvement CtudiC la dCcomposition thermique. Les produits sont les mCmes que ceux obtenus par photolyse; sur la base de la formation du CO,, qui est apparemment un processus unimolCculaire simple et homogtne, on a aussi obtenue les paramttres dlArrhCnius qui sont: log A (s-I) = 7,19 et E = 27,7 kcal/mol.[Traduit par le journal]
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