An ultrastructural study of spermatozoa in a series of 247 severely asthenozoospermic patients disclosed two kinds of anomalies. The first was dysplasia of the fibrous sheath, a primary defect of spermatozoa with hypertrophy and hyperplasia of the fibrous sheath, associated axonemal anomalies, familial incidence and chronic respiratory disease. The patients could be divided into two subgroups: the complete form (all spermatozoa affected) and the incomplete form (alterations in 70-80% spermatozoa). There were no spontaneous or in-vitro fertilization (IVF) pregnancies. Intracytoplasmic sperm injection (ICSI) in six patients resulted in successful fertilizations, but only two pregnancies were obtained. These features configure a phenotype that suggests a genetic origin. The second anomaly was non-specific flagellar anomaly (NSFA), random secondary flagellar alterations affecting variable numbers of spermatozoa, without respiratory disease or familial incidence. 54 men with NSFA were followed for 2-6 years. Of these, 18 achieved conception, either spontaneous or by means of assisted fertilization, followed by 14 pregnancies and 12 live births. Their sperm motility significantly increased during the follow-up period. In the remaining 36 men motility did not change during the follow-up period and there were no fertilizations or pregnancies. We conclude that in severe asthenozoospermia, ultrastructural examination of spermatozoa has an effective prognostic value, identifying two syndromes with very different flagellar alterations and fertility potentials.
BackgroundIn assisted reproduction cycles, gonadotropins are administered to obtain a greater number of oocytes. A majority of patients do not have an adverse response; however, approximately 3-6% develop ovarian hyperstimulation syndrome (OHSS). Metformin reduces the risk of OHSS but little is known about the possible effects and mechanisms of action involved.ObjectiveTo evaluate whether metformin attenuates some of the ovarian adverse effects caused by OHSS and to study the mechanisms involved.Material and methodsA rat OHSS model was used to investigate the effects of metformin administration. Ovarian histology and follicle counting were performed in ovarian sections stained with Masson trichrome. Vascular permeability was measured by the release of intravenously injected Evans Blue dye (EB). VEGF levels were measured by commercially immunosorbent assay kit. COX-2 protein expression was evaluated by western blot and NOS levels were analyses by immunohistochemistry.ResultsAnimals of the OHSS group showed similar physiopathology characteristics to the human syndrome: increased body weight, elevated progesterone and estradiol levels (P<0.001), increased number of corpora lutea (P<0.001), higher ovarian VEGF levels and vascular permeability (P<0.001 and P<0.01); and treatment with metformin prevented this effect (OHSS+M group; P<0.05). The vasoactive factors: COX-2 and NOS were increased in the ovaries of the OHSS group (P<0.05 and P<0.01) and metformin normalized their expression (P<0.05); suggesting that metformin has a role preventing the increased in vascular permeability caused by the syndrome.ConclusionMetformin has a beneficial effect preventing OHSS by reducing the increase in: body weight, circulating progesterone and estradiol and vascular permeability. These effects of metformin are mediated by inhibiting the increased of the vasoactive molecules: VEGF, COX-2 and partially NOS. Molecules that are increased in OHSS and are responsible for a variety of the symptoms related to OHSS.
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