Association Between DMSO and Sugars in the Sperm Cryopreservation of Pacu.

　　BACKGROUND: The cryopreservation protocol that has been developed exclusively for the preservation of the sperm of the species different. OBJECTIVE: this study was to evaluate the effect of the association of 10% DMSO with trehalose, raffinose, sucrose and lactose concentrations on the sperm cells of Piaractus mesopotamicus. MATERIALS AND METHODS: Sperms were collected from the animals through abdominal massage. The samples were diluted in the Beltsville Thawing Solution without different concentrations of other sugars (test conditions). Sixty days after the cryopreservation, cell movement analysis was performed using CASA. RESULTS: The results revealed that the parameters for total motility and motility period were superior when 100mM raffinose (P <0.05). The lateral displacement of the head was observed to be improved was 100mM lactose, 150mM sucrose and 150mM raffinose (P <0.05) as compared to treatment wherein lactose (0mM) was omitted. CONCLUSION: the results of our study indicated that the ideal parameters for cryopreservation, were obtained when the cryopreservation fluid contained 100mM raffinose in association with DMSO.

Perinatal health and mother-child health care in the municipality of São Luís, Maranhão State, Brazil.

The purpose of this article was to evaluate socioeconomic and demographic indicators, reproductive health, use of prenatal, childbirth, and neonatal services, and anthropometric data for mothers and infants. The authors performed a cross-sectional analysis of a systematic sample of 2,831 hospital births in São Luís, Maranhão State, from March 1997 to February 1998 at ten public and private maternity hospitals. The sample was stratified proportionally according to the number of births in each maternity hospital. Mothers answered a standard questionnaire. Of the total, 97.9% were live births and 98% were singletons. Prenatal coverage was 89.5%, and prevalence of cesarean sections was 33.8%. A physician provided prenatal care in 75.7% of cases and performed 73.8% of the deliveries. The Unified Health System covered the costs of 76.4% of the prenatal visits and 89.7% of the deliveries. A pediatrician was present in the delivery room in 50.2% of cases. The low birth weight rate was 9.6% and the preterm birth rate 13.9%. Reasons for concern included a high percentage of adolescent mothers, single mothers (or without partners), the high cesarean rate, and the high percentage of births attended by unqualified personnel.

Isolation and characterization of mutants affected in the expression of the nar operon Escherichia coli.

In the nitrate reductase system of Escherichia coli, the maximal expression of the nar operon is obtained under anaerobiosis in the presence of nitrate. Mudl (Ap,lac) insertion mutants, which only grew on lactose anaerobically if supplemented with nitrate were mapped at the chlC locus at min 27 of the map. In these fusion strains which lack benzyl viologen dependent nitrate reductase (NR) activity as well as the formiate-linked NR activity, the synthesis of beta-galactosidase reflects the regulation of the wild type nar operon at the transcriptional level. From these strains, two classes of spontaneous regulatory mutants were isolated: class I mutants which synthesized beta-galactosidase in anaerobiosis in the absence of nitrate and class II mutants in which the synthesis of that enzyme was partially independent of nitrate and it was no longer repressed by oxygen. The class I regulatory mutation was tightly linked to the nar operon as shown by bacteriophage P1 transductions. It probably affects either a closely linked cis-active element or a gene coding for a negative regulatory protein.