In a prospective, randomized, placebo-controlled 12-wk study, we investigated the effect of oral hormone replacement therapy on asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), and an independent risk factor for coronary heart disease. The effects on arginine and symmetric dimethylarginine were also investigated. Sixty healthy early postmenopausal women received daily placebo (n = 16) or oral 17beta-estradiol 2 mg, either unopposed (E(2); n = 16) or sequentially combined with dydrogesterone 10 mg (E(2)+D; n = 14) or trimegestone 0.5 mg (E(2)+T; n = 14). ADMA levels reduced in all active treatment groups. Compared with baseline and placebo, the largest reduction in ADMA levels was observed in the E(2)+T group [-18.7% (95% confidence interval [CI], -25.4 to -11.9%) and -21.1% (95% CI, -26.2 to -16.1%), at 4 and 12 wk, respectively]. At 4 and 12 wk in the E(2)+T group, arginine levels were significantly reduced as well [-30.9% (95% CI, -41.1 to -20.7%) and -36.3% (95% CI, -43.1 to -29.5%), respectively], whereas symmetric dimethylarginine levels were significantly lower in the E(2)+D group after 12 wk [-11.6% (95% CI, -19.9 to -3.3%)]. In conclusion, unopposed oral estradiol and estradiol combined with dydrogesterone or trimegestone reduced plasma levels of the NOS inhibitor ADMA. Whether the reduction of the NOS substrate arginine in the E(2)+T group counteracts the potentially beneficial effect of ADMA reduction or reflects increased NO production remains to be investigated.
Traditionally, it is understood that dizygotic (DZ) twins always have a dichorionic placenta. However, with 8% blood chimerism in DZ twins, placental sharing is probably more common than previously has been recognized. In this article, we will review all available cases of monochorionic dizygotic (MCDZ) twins. A total of 31 twins have been described in literature. A monochorionic diamniotic placenta is reported in all cases. Assisted reproductive technology is responsible for the origin of the pregnancy in 82.1% of the cases. In 15.4% of the sex-discordant twins, a genital anomaly was reported in one of the twins. Chimerism is demonstrable in 90.3% of the twins, leading to various diagnostic difficulties. As this review shows that most MCDZ twins are discovered by accident, it can be argued that it is far more common than has been assumed until now. However, the prevalence is still unclear. Awareness of MCDZ twinning is important, with subsequently correct medical strategies. Similarly, the resulting (blood) chimerism is essential to consider in diagnostic procedures, pre- and postnatally. More research on the effect of placental transfusion between sex-discordant twins is required.
The supplement containing soy isoflavones and A racemosa L. had no statistically significant effect on climacteric symptoms in perimenopausal women experiencing at least five vasomotor symptoms per day.
The ID-LC-MS/MS assay measures serum testosterone with acceptable accuracy and is useful in female samples, supporting the conclusion that the postmenopausal ovary contributes to circulating testosterone. To our knowledge, our analytical method compares favourably to similar published methods in terms of sensitivity. The sensitivity and specificity of this method comply with the reference method for measurement of testosterone in serum samples of women, children and men suffering from hypogonadism and can also be used for men with testosterone in the reference range.
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