Lower follicular fluid vitamin D concentration is related to a higher number of large ovarian follicles.

Vitamin D receptor-knockout mice fail to produce mature oocytes, indicating vitamin D is crucial for folliculogenesis in mice. However, the actions of vitamin D during folliculogenesis remain unknown. This prospective study aimed to assess whether follicular fluid (FF) vitamin D (25OHD3) concentrations are related to specific responses to ovarian stimulation. Women undergoing ovarian stimulation for IVF participated in the study. FF 25OHD3 concentrations were assessed in the first follicle aspirate on oocyte retrieval day. Oestradiol and progesterone concentrations were assessed on the trigger day. K-means grouping analysis showed that 25OHD3 FF concentrations clustered into a higher and lower group (mean ± SEM 17.4 ± 6.61 ng/ml and 35.5 ± 7.17 ng/ml, respectively, P < 0.001). The clusters were analysed according to the oestradiol and progesterone concentrations, follicle number and size and resulting oocyte number and maturity. The FF 25OHD3 concentrations were no different among the infertility diagnoses. The lower 25OHD3 group had more follicles (≥16.0 mm, P = 0.009) and higher serum oestradiol concentrations (P < 0.03) on the day of HCG administration. In this study, lower follicular 25OHD3 concentrations predicted a better response to ovarian stimulation shown by a greater production of larger follicles and higher serum oestradiol concentrations.

Positive end-expiratory pressure and variable ventilation in lung-healthy rats under general anesthesia.

OBJECTIVES: Variable ventilation (VV) seems to improve respiratory function in acute lung injury and may be combined with positive end-expiratory pressure (PEEP) in order to protect the lungs even in healthy subjects. We hypothesized that VV in combination with moderate levels of PEEP reduce the deterioration of pulmonary function related to general anesthesia. Hence, we aimed at evaluating the alveolar stability and lung protection of the combination of VV at different PEEP levels. DESIGN: Randomized experimental study. SETTING: Animal research facility. SUBJECTS: Forty-nine male Wistar rats (200-270 g). INTERVENTIONS: Animals were ventilated during 2 hours with protective low tidal volume (VT) in volume control ventilation (VCV) or VV and PEEP adjusted at the level of minimum respiratory system elastance (Ers), obtained during a decremental PEEP trial subsequent to a recruitment maneuver, and 2 cmH2O above or below of this level. MEASUREMENTS AND MAIN RESULTS: Ers, gas exchange and hemodynamic variables were measured. Cytokines were determined in lung homogenate and plasma samples and left lung was used for histologic analysis and diffuse alveolar damage scoring. A progressive time-dependent increase in Ers was observed independent on ventilatory mode or PEEP level. Despite of that, the rate of increase of Ers and lung tissue IL-1 beta concentration were significantly lower in VV than in VCV at the level of the PEEP of minimum Ers. A significant increase in lung tissue cytokines (IL-6, IL-1 beta, CINC-1 and TNF-alpha) as well as a ventral to dorsal and cranial to caudal reduction in aeration was observed in all ventilated rats with no significant differences among groups. CONCLUSIONS: VV combined with PEEP adjusted at the level of the PEEP of minimal Ers seemed to better prevent anesthesia-induced atelectasis and might improve lung protection throughout general anesthesia.