The Mayer-Rokitansky-Küster-Hauser syndrome (congenital absence of uterus and vagina) – phenotypic manifestations and genetic approaches

The Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome affects at least 1 out of 4500 women and has for a long time been considered as a sporadic anomaly. Congenital absence of upper vagina and uterus is the prime feature of the disease which, in addition, is often found associated with unilateral renal agenesis or adysplasia as well as skeletal malformations (MURCS association). The phenotypic manifestations of MRKH overlap various other syndromes or associations and thus require accurate delineation. Since MRKH manifests itself in males, the term GRES syndrome (Genital, Renal, Ear, Skeletal) might be more appropriate when applied to both sexes. The MRKH syndrome, when described in familial aggregates, seems to be transmitted as an autosomal dominant trait with an incomplete degree of penetrance and variable expressivity. This suggests the involvement of either mutations in a major developmental gene or a limited chromosomal deletion. Until recently progress in understanding the genetics of MRKH syndrome has been slow, however, now HOX genes have been shown to play key roles in body patterning and organogenesis, and in particular during genital tract development. Expression and/or function defects of one or several HOX genes may account for this syndrome

Microwave loss and intermodulation in Tl(2)Ba(2)CaCu(2)O(y) thin films

Willemsen BA, Kihlstrom KE, Dahm T, et al. Microwave loss and intermodulation in Tl(2)Ba(2)CaCu(2)O(y) thin films. Physical Review B. 1998;58(10):6650-6654.A superconducting microstrip hairpin resonator is used as a tool to study the linear and nonlinear microwave response of TBCCO thin films. We extract the surface resistance R(S)(T), penetration depth lambda(T), and intermodulation critical current J(IMD)(T) for such a resonator at 4.2 GHz. The surface impedance results compare well with cavity perturbation measurements on portions of the same wafer. J(IMD)(T) is compared against theoretical models for the intrinsic nonlinear response of s- and d-wave superconductors. We demonstrate that the de critical current J(c) and J(IMD) are distinct material parameters, describing different physical regimes

Miscarriage risk for IVF pregnancies in poor responders to ovarian hyperstimulation

The increasing miscarriage rate with advancing female age is attributed to a decline in oocyte quality. A poor response to ovarian hypestimulation is often an expression of a decrease in oocyte quantity. Although oocyte quality and quantity both decrease as a result of ovarian ageing, it is unclear whether these two processes are related to each other. To investigate the relationship between oocyte quantity and quality, we compared miscarriage rates between IVF treated women with a poor and normal response, respectively. Data were studied from a retrospective nationwide cohort of Dutch women undergoing IVF treatment from 1983 to 1995. Women achieving an ongoing pregnancy after their first complete IVF cycle (n = 1468) were compared with those experiencing miscarriage (n = 357) with respect to their ovarian response. Logistic regression analysis showed a statistically significant association between poor response (fewer than four retrieved oocytes) and miscarriage (P = 0.001). Due to interaction, this association became stronger with increasing female age. Among women &lt;36 years, miscarriage rates between poor and normal responders did not differ, whereas among women 36 years poor responders had a statistically significant increased miscarriage rate compared with normal responders (P = 0.001). These results support the hypothesis of a relationship between quantitative ovarian reserve and oocyte quality.<br/