Adolescent sexuality: Part 4. The practitioner''s role

As no systematic study has been done to get an accurate estimate of the incidence of return to oestrus after first insemination in sows in the Netherlands, the objectives of this investigation were: 1) to obtain an estimate of the incidence of return to oestrus after insemination at the herd level; 2) to investigate the association between incidence of return to oestrus after first insemination and reproduction characteristics in order to get an impression of the economic importance of reproductive failure. These objectives were investigated by using the reproduction results of 240 swine breeding herds in the Southern Netherlands in 1987. This information was obtained from CBK plus computerized herd management records. The average incidence rate of return to oestrus after first insemination at a herd level was 16.9 per 100 first inseminations. The occurrence of return to oestrus after first insemination was distinctly higher in the insemination months July and August compared to the rest of the year. An increased incidence, with 10 returns per 100 first inseminations corrected for confounders in a multiple linear regression model, was associated with a decrease of approximately 0.3 live born piglets/sow/year. A prospective longitudinal study was started in 1988 and 1989 in 37 sow herds. Individual sows were monitored from weaning to first insemination, to the occurrence of return to oestrus, or not, after first insemination, and to farrowing. The investigation focused in particular on the relationship between return to oestrus after first insemination and seroconversion against porcine parvovirus (PPV) and Leptospira interrogans serovar bratislava (L. bratislava).(ABSTRACT TRUNCATED AT 250 WORDS)     

The immunologic identification of abnormal hemoglobins

Guinea pig antisera against human hemoglobin contain antibodies to multiple antigenic determinants. Hemoglobin variants having single amino acid substitutions affecting these determinants are recognized as antigenically deficient in a radioimmunoassay system. The multivalent antisera may be made more selective by appropriate absorption with hemoglobin variants. Three such antisera containing antibodies specific, respectively, for the beta-chain of Hb A, Hb S, and Hb C are described. They can differentiate among the hemoglobins of individuals who possess these variants alone or in any paired combination. Their discriminating ability is not hindered by the presence of 1,000-fold concentrations of Hb F and may therefore be extended to the early prenatal diagnosis of sickling disorders. The antisera described also detect several other variants of Hb A. The approximate location of the substitution in variants so detected can be determined by a complementation test. This is based on the finding that two antigenically deficient hemoglobins will complement each other in mixture provided their amino acid substitutions involve different determinants.     

A phase I dose-ranging safety and pharmacokinetics study of a novel oral thromboxane synthase inhibitor, FCE 22, 178

A 100- to 3200-mg dose range of FCE 22,178 was studied in this phase I single-dose escalation safety/kinetics study. After oral administration, a rapid drug absorptive phase and a biexponential disposition profile were observed. Mean estimates of the terminal elimination half-life of FCE 22,178, over the doses studied, ranged from 7.6 to 14.4 hours. A disproportionate increase in both maximum peak plasma concentration (Cmax) and area under the curve (AUC0-infinity) was noticed for doses higher than 400 mg. Mean estimates of systemic clearance (CLs/F) over the 100- to 400-mg doses were 0.053 to 0.064 L/hour/kg, and were significantly higher for the three higher dose levels. This nonlinearity appears to be related to the changes in oral bioavailability. Estimates of distribution volume (Vd, lambda z/F) for FCE 22,178 increased from 0.75 L/kg at the 100-mg dose to 3.00 L/kg at the 3200-mg dose, and renal clearance (CLr) also increased with dose. Both observations may be related to an increase in free fraction of FCE 22,178 at higher doses. Urinary excretion of unchanged drug averaged < 10% for all dose levels. The urinary excretion of the glucuronide metabolite (M1) averaged 41 to 70% for doses up to 400 mg, but diminished to 13% at the 3200-mg dose. The disposition of M1 appeared to be formation-rate limited. In addition, the ratio of the formation to the disposition clearance for M1 was relatively stable and apparently dose independent. No drug-related adverse experiences were observed over the studied dose range after single doses at FCE 22,178.     

Pharmacological protection of CNS white matter during anoxia: actions of phenytoin, carbamazepine and diazepam

The effects of phenytoin (DPH), carbamazepine (CBZ) and diazepam (DZP) on anoxia-induced injury in CNS white matter were studied using the in vitro rat optic nerve preparation. Optic nerves were subjected to 60 min of anoxia and functional recovery was assessed using the area under the compound action potential. Under normoxic conditions, application of DPH, CBZ and DZP reduced compound action potential area over concentration ranges known to block sodium channels. All three compounds, however, protected against anoxic injury at concentrations below those that inhibited the normoxic compound action potential. Thus, the application of 1 microM DPH, CBZ or DZP during anoxia resulted in compound action potential recovery to 60.0, 53.8 and 69.2% of control, respectively, compared to compound action potential recovery of 34.8% in the absence of drugs (P < .05 in all three cases). In the cases of CBZ and DPH, 60% improvement in recovery from anoxia was produced by concentrations well below those employed clinically to treat epilepsy, suggesting a potential role for these drugs in the protection of CNS white matter from anoxic injury.