Detailed Morphological Analysis of Cryoinjury in Human Ovarian Tissue Following Vitrification or Slow Freezing.

Cryopreservation of human ovarian tissue represents a key procedure for fertility preservation. The two most widely used cryopreservation methods for human ovarian cortex samples are slow freezing\thawing (SF\T) and vitrification\warming (V\W). The aim of the present study was to analyze the effects of SF\T and V\W using a metal chamber, on specific follicle and oocyte structures and on the stromal organization post-cryopreservation. We did histology analysis of SF\T and V\W ovarian fragments from nine healthy subjects. Overall results showed that cryopreserved tissues presented significant rates of damage in primordial and primary follicles. Altered nuclear structure of primordial follicles and cell detachment from primordial and primary follicles were the main injuries observed after V/W and SF/T. The stromal components were similarly well preserved after cryopreservation. We conclude that both cryopreservation methods may be used for fertility preservation purposes with similar outcomes in terms of follicular and stromal integrity. Detachment of follicle cells from basal membrane represents an important cryoinjury that deserves further investigation.

Nitric oxide and fibrinogen in polycystic ovary syndrome: associations with insulin resistance and obesity.

OBJECTIVE: Nitric oxide (NO) and fibrinogen levels, two markers of vascular disease, are associated with insulin resistance, a common trait in women with polycystic ovary syndrome (PCOS). STUDY DESIGN: Case-control study including 31 women with PCOS and 21 age-matched women with regular, ovulatory cycles, normal androgen levels and idiopathic hirsutism (control group). Nitrite/nitrate concentration (index of endothelium-derived NO) and fibrinogen plasma levels were assessed and analysed in association with anthropometric, metabolic and hormonal variables. RESULTS: The groups were similar in terms of age, positive family history of diabetes and Ferriman-Gallwey hirsutism score. Nitrite/nitrate and fibrinogen levels were also similar in the two groups. In contrast, in PCOS patients, insulin levels and the homeostatic model assessment were negatively correlated with NO production (r=-0.39, p=0.03 and r=-0.41, p=0.02, respectively). Age, BMI, waist circumference and waist-to-hip ratio were positively correlated with fibrinogen in both groups. CONCLUSION: The present data indicate a negative, BMI-independent association between NO levels and insulin resistance in PCOS patients. Further studies are required to clarify the role of androgens on the pathogenesis of endothelial dysfunction in PCOS and investigate androgen action and/or the gene receptor modulating NO secretion.