SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
The effect of different dietary protein contents (19.3%, 14.9%, 11.0% and 5.7%) on weight gain was investigated in a genetically heterogeneous population of mice. Significant difference in weight gain was found only in the early growth period and was due mainly to the reduced weight gain of mice fed the diet with the lowest protein content. Feeding the mice low protein diets during the growth period did not affect reproductive performance.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Investigations on the biology of Phlebotomus papatasi were carried out under laboratory conditions at 28 +/- 2 degrees C and 80 +/- 1% RH. Fecundity of the female varied between 61 and 48 (mean 56.2 +/- 5.46) and the incubation period of eggs ranged from 7-9 (mean 7.81 +/- 0.61) days. The developmental duration of larvae and pupae varied from 24 to 31 (mean 28.57 +/- 2.71) and 9 to 11 (mean 10.38 +/- 1.51) days, respectively. The rate of insemination, determined from the females that laid fertile eggs, was found to be maximum when the females were three days old. Autogeny was observed from female sandflies, emerged from the larvae fed on animal liver powder. The duration of first and second gonotrophic cycles under ambient conditions was shortest in summer and longest in winter. Studies on adult longevity showed that the females fed on mouse blood survived for 6 to 27 days (mean 14 +/- 12.5 days).
In natural ambient conditions at Possession Island the resting metabolism of the emancipated King Penguin is 50.40 kcal/kg/D. A bird whose insulation is good and which maintains its stomachic temperature at a high level can reduce its heat production by 42% during the long fasting periods which characterize its reproductive cycle, in particular by social and individual thermoregulating behaviour.
PROBLEM/CONDITION: In the United States, approximately 600,000 hysterectomies are performed each year, and the procedure is the second most frequently performed major surgical procedure among reproductive-aged women. REPORTING PERIOD COVERED: 1980-1993. DESCRIPTION OF SYSTEM: This surveillance system uses data obtained from CDC's National Hospital Discharge Survey (NHDS) to describe the epidemiology of hysterectomy. The NHDS is an annual probability sample of discharges from non-Federal, short-stay hospitals in the United States. RESULTS: In the United States during 1980-1993, an estimated 8.6 million women aged > or =15 years had a hysterectomy. The overall rate of hysterectomy declined slightly from 1980 (7.1 hysterectomies per 1,000 women) to 1987 (6.6 per 1,000 women). The redesign of the NHDS in 1988 resulted in a decrease in estimated rates (i.e., the average annual rate for 1988-1993 was 5.5 per 1,000 women). Rates differed by age, with women aged 40-44 years most likely to have this procedure. Overall annual rates of hysterectomy did not differ significantly by race. The diagnosis most often associated with hysterectomy was uterine leiomyoma; during 1988-1993, this diagnosis accounted for 62% of hysterectomies among black women, 29% among white women, and 45% among women of other races. During 1988-1993, the percentage of hysterectomies performed by the vaginal route increased significantly; furthermore, an increasingly higher percentage of vaginal hysterectomies were accompanied by bilateral oophorectomy. From 1991 through 1993, laparoscopy was associated more frequently with vaginal hysterectomy than in previous years. INTERPRETATION: The rate of hysterectomy decreased slightly during the first half of the 14-year surveillance period, then leveled off during the second half. The increase in simultaneous coding of laparoscopy and vaginal hysterectomy on hospital discharge forms probably reflected the growing use of laparoscopically assisted vaginal hysterectomy. ACTIONS TAKEN: Continued surveillance for hysterectomy will enable changes in clinical practice (e.g., the use of LAVH) to be identified, and information derived from the surveillance system may assist in directing biomedical assessment priorities (e.g., to determine the reasons for race-specific differences in the prevalence of uterine leiomyoma).
Explore the source record for details and available documents.
The achievement or reproductive intentions of Sri Lankan women was examined by using longitudinal data for the period 1982-85. Aggregate consistency between reproductive intentions and behavior was almost perfect, but at the individual level there were inconsistencies. Among those who wanted to have no more children, 23 per cent reported a birth in the intersurvey period of 3 years and 2 months, while failures to have a wanted birth stood at 36 per cent. There was a clear declining trend in the former type of inconsistencies in Sri Lanka, but the latter type has increased, possibly due to a continuing decline in family size ideals or due to deferred childbearing. Even though inconsistencies existed, expressed fertility intentions in 1982 significantly influenced the fertility outcome. The study also has a methodological focus on whether to include sterilized women when fertility intentions and behavior are examined longitudinally, but no specific problems were found with their inclusion. Results indicate that, apart from the intention variable, age, marital duration, family size, and education of husband and wife variables all influenced fertility in the follow-up period.
To assess the efficacy of different period of treatment for evaluating male reproductive toxicity in rats, reserpine was subcutaneously administered on a daily basis to male Sprague-Dawley rats at dosages of 0.05, 0.1 or 0.2 mg/kg for 2 weeks or at dosages of 0.05 or 0.1 mg/kg for 4 weeks. At the end of the administration period the animals were sacrificed and sperm counts, organ weights and histopathological changes in the reproductive organs were examined. The sperm number in the caudal epididymis and genital organ weights were not affected by reserpine with either 2- or 4-weeks treatment. In the 4-weeks study, histopathological examination of the testes revealed retention of step 19 spermatids in the seminiferous tubules of stages IX to XII and decreased secretory content of the prostate in the 0.05 and 0.1 mg/kg groups. In the 2-weeks study, although no distinct histopathological changes were observed in the 0.05 mg/kg group, decreased secretory content of the prostate, apoptosis of spermatocytes in the seminiferous tubules of stage VII and cell debris of the epididymis were observed in the 0.1 and 0.2 mg/kg groups. These results suggested that 2-weeks treatment with reserpine is sufficient for detection of testicular toxicity, although higher dosage levels are appropriate than for 4-weeks treatment.
Polychlorinated biphenyls (PCBs) have been found widely distributed in the ecosystem, including human milk, yet there is limited information concerning the effect that PCB exposure during the postnatal period might have on subsequent reproductive capacity of adult male offspring. In this study, fertility and condition of reproductive organs were examined in male offspring of rats that received Aroclor 1254 orally (8, 32, or 64 mg/kg) on Days 1-3, 5, 7, and 9 of lactation. It was found that the experimental male offspring as adults were less successful in mating and reproducing when compared with control offspring. Virgin females mated with males exposed through suckling to the two higher doses of PCBs had a significantly lower proportion of ovulated eggs that implanted, a significantly lower number of live fetuses, and a significantly higher rate of resorption. At autopsy, although body weights were not significantly different, ventral prostate weights were significantly less in all treated male offspring; there were fewer alveoli and flattened epithelial cells in these glands as compared to controls. Seminal vesicle weights were significantly less in males exposed to the two higher doses of PCBs, while the testes were significantly larger. PCB-derived material remained in adipose tissue and liver at the time of autopsy. These data support the hypothesis that exposure of male offspring to PCBs during early postnatal development results in an hypoandrogenic condition that is detrimental to normal reproductive functioning in the adult.
Stimulation of the bag cell neurons of Aplysia activates several biochemical pathways, including protein kinase C (PKC), and alters their excitability for many hours. After an approximately 30 min afterdischarge, these neurons enter an approximately 18 hr inhibited state during which additional stimulation fails to evoke discharges. In vivo, this refractory period limits the frequency of reproductive behaviors associated with egg laying. We have now examined the role of Ca2+-activated K+ (BK) currents in the refractory period. Outward currents gated by both intracellular Ca2+ and depolarization, with pharmacological characteristics of BK currents, were recorded in isolated bag cell neurons. These currents were enhanced by the BK channel activators phloretin and 1,3-dihydro-1-[2-hydroxy-5-(trifluoro-methyl)phenyl]-5-trifluoromethyl-2H-benzimidazol-2-one and inhibited by the BK blocker paxilline. The BK component of K+ current was enhanced by 12-O-tetradecanoyl-phorbol-13-acetate, an activator of PKC, and this effect was blocked by sphinganine and PKC(19-36), inhibitors of PKC in bag cell neurons. To test whether the BK current is altered during the refractory period, intact clusters were stimulated to afterdischarge, and neurons were isolated after the clusters had entered the refractory period. Compared with unstimulated cells, current density was almost doubled in refractory neurons. This increase in current was inhibited by preincubating clusters in sphinganine. Treatment of refractory clusters with paxilline significantly restored the ability of stimulation to evoke afterdischarges. Conversely, application of phloretin to previously unstimulated clusters inhibited the onset of afterdischarges. These results indicate that a prolonged increase in BK channel activity contributes to the prolonged refractory period of the bag cell neurons.
An analysis of computerized data on the incidence and consequences of reproductive disorders was performed on 84,818 lactations in more than 100 high producing Kibbutz dairy herds during six semiannual recording periods. The average incidence of primary reproductive disorders, which included retained placenta, abnormal lochia, endometritis, postpartum anestrus, cystic ovaries, negative pregnancy examinations and repeat breeders, was 50.4%. During all recording periods we were able to observe recurrence and repeatability of these reproductive disorders and of the fertility indices consequently seen. Cows with uterine infections diagnosed and treated before Day 20 post partum had better fertility indices than those diagnosed and treated later. The conception rate to first inseminations and the overall conception rate to all inseminations of cows with postpartum anestrus was significantly lower, while the percentage of "problem cows" (not pregnant by Day 150 post partum) was significantly higher, than in normal cows. The incidence of cystic ovaries in cows with a previous diagnosis of reproductive disorders was 2 to 3 times higher when compared to cows without such a diagnosis.
Six adult Soay rams were housed under artificial lighting conditions with alternating 16-week periods of long (16 h light: 8 h darkness) and short days (8L:16D) During long days the rams were reproductively quiescent: the abrupt change from long to short days induced a specific succession of responses in the reproductive system. Plasma LH and FSH levels began to increase after 2-4 weeks, followed almost immediately by a rise in plasma testosterone levels accompanied by growth of the testes. Testicular activity continued to increase during short days and the greatly elevated androgen levels apparent after 5-10 weeks caused changes in the peripheral target organs, including growth of the epididymides, development of the sexual flush on the exposed ventral skin and heightened genital sensitivity. High testosterone levels were also associated with an increase in aggressive (scored by a mechanical device) and sexual (incidence of Flehmen) behavior which was at peak about 1 month after the start of the peak androgen levels. The change to long days was associated with a decrease in plasma gonadotrophin levels within 2 weeks followed by a progressive decline in all reproductive parameters measured. Implantation of a low dose of testosterone (200 mg) during the period of reproductive quiescence induced the development of the sexual flush and an increase in genital tactile sensitivity, although behaviour was not significantly affected. The annual changes in reproductive physiology and behaviour of 12 Soay rams living under natural lighting conditions were recorded for comparison with the experimental situation. The nadir of the sexual cycle was in the spring and early summer, and the sequence of events culminating in the mating season in the autumn was similar to that induced experimentally.