PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Reproductive Period”

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.

At least 1,081 records · Page 60Linked to original sources
PubMed2002

Lead intoxication in gestational and lactation periods alters the development of male reproductive organs.

The effect of lead (Pb) intoxication during pregnancy and lactation on the male reproductive system was studied to evaluate the alterations caused by Pb in the development of pups. The investigations covered the effect of lead on the course of spermatogenesis and the development of the epididymis and reproductive glands. For this purpose, dams were intoxicated with 300 mg/L Pb during the gestational period and through lactation. Pups were sacrificed on Postnatal (PN) Days 12 and 21. Blood lead (PbB) and plasma iron concentrations were measured, and blood cells counted. Biochemical studies as well as histochemical analyses were performed on testes and accessory glands of the reproductive system. Lead intoxication resulted in a decrease in testis and seminal vesicle weights and an increase in DNA and RNA levels on PN Day 21. Total protein was significantly decreased by the toxicant, and alkaline and acid phosphatase levels of the gonads were reduced. Effects were also reflected in the reduction of the thickness of epithelium and of seminiferous tubule diameter (STD) as a consequence of the action of lead in the reduction in numbers of prospermatogonia and spermatocytes. Results indicate that the reproductive system targets of lead intoxication are not only the testes; lead intoxication results in the inhibition of testicular, epididymal, and seminal vesicle function, altering the biochemical composition of these organs, and consequently, affecting the normal development of germinal cells.

Animals↗
PubMedDate not supplied

Reproductive pattern in consanguineous and non-consanguineous marriages in La Cabrera, Spain.

BACKGROUND: Among determinants of the structure of human populations, consanguineous marriages can be useful in determining to what extent they influence the genetic structure of the population. This knowledge may be gained by comparing the reproductive performance of related and non-related couples. The population studied, La Cabrera, is a mountainous region in the Leon province (north-western Spain). It includes four neighbouring municipalities with similar geographic, climatic and ecological features with 37 parishes occupying an area of 784.2 km(2), of which only 1.5% is arable. The number of inhabitants remained stable from 1887 (9526 inhabitants) to 1960 (8984), when due to emigration it began to decrease. The average inbreeding coefficient (alpha) for the period 1880-1989 (up to third degree) was 4.82 x 10(-3). AIM: The objective of this analysis was to evaluate the possible factors determining the differences between consanguineous and non-consanguineous families residing in La Cabrera during the period 1880-1959. SUBJECTS AND METHODS: To study the structure and dynamics of each couple, families were reconstituted for the period 1880-1959 using demographic data corresponding to births, deaths and marriages obtained from parish registers. This procedure provided information on each couple's reproductive history through information concerning the mates' deaths as well as their offspring's births and deaths. Principal component analysis revealed the existence of three factors that together explained 57% of the reproductive pattern variability of La Cabrera. RESULTS: The first component (eigenvalue: 3.56) correlated positively with the number of live births and with the duration of the reproductive period. Component II (eigenvalue: 1.54) had a positive correlation with variables describing the beginning of the marital union, and with those indicating its ending. Finally, component III (eigenvalue: 1.13) reflected a negative association with the two variables that described neonatal and post-neonatal mortality. The above demographic variables represented the reproductive process in La Cabrera adequately. Fertility was the variable that offered the best explanation of the reproductive pattern (32%), followed by the marital structure (13%) and the infant mortality (12%). CONCLUSION: In the La Cabrera population, consanguinity appears as a socio-cultural process that affects the reproductive dynamic. Consanguinity modifies the marital structure and alters the reproductive pattern, prolonging the reproductive period, which results in a greater number of offspring. Lower infertility rates and the possible compensatory effect for infant mortality may reflect biological factors making the wife's reproductive period more efficient.

Adult↗
PubMed1994

Maternal energy depletion is buffered among malnourished women in Punjab, Pakistan.

Women's nutritional status is believed to deteriorate with increasing reproductive stress (so-called maternal depletion). To evaluate this phenomenon, a new theoretical framework has been suggested that incorporates the concepts of a full reproductive cycle, relative lengths of potential depletion and repletion phases, and initial plane of nutrition. We developed the corresponding statistical model and tested predictions provided by the framework about the effect of reproductive pattern on maternal overall weight change (deltaW) during one reproductive cycle. Seventy-six Pakistani women were classified as well-nourished, marginally nourished or malnourished. The relationship between deltaW and length of all phases of the reproductive cycle, each of which is characterized by varying degrees of reproductive stress, was evaluated with multiple regression analysis. Across the reproductive cycle, well-nourished women had a slight weight increase. Surprisingly, malnourished women gained weight in contrast to marginally nourished women. Also surprisingly, for the latter two groups, periods of moderate reproductive stress were associated with weight loss but periods of high reproductive stress were associated with weight gain. Mechanisms such as efficiency and nutrient partitioning are discussed.

Adult↗
PubMed1978

Periodic, short-term heat exposure and reproductive function in male and female rats.

Reproductive function of male and female rats was examined in relation to periodic, short-term heat treatment. Daily exposure to an environmental temperature of 38.2 degrees C for 55 min elevated rectal temperatures to 39.9 and 41.2 degrees C in male and female rats, respectively. Heat exposure tended to decrease copulation in males cohabitated with unheated females. The rate of conception was affected similarly, and fetal survival tended to be reduced by paternal heat treatment. Estrous cycles were disrupted initially in heat-exposed females, but the rate of copulation and conception of females cohabitated with unheated males was unaltered by heat treatment. However, maternal heat exposure impaired prenatal survival and growth. During lactation, a high incidence of maternal and pup deaths was observed at approximately 14 days postpartum. Maternal deaths were coincident with a decrease in thermoregulatory ability and rectal temperatures exceeding 42 degrees C.

Animals↗
PubMedDate not supplied

Are precocial young cheaper? Lactation energetics in the guinea pig.

Caviomorphs stand out from other small rodents by producing extremely precocial young. Pups begin to nibble solid food right after birth and can survive weaning when 5 d old. We tested whether these properties of young lead to a low cost of lactation in guinea pigs (Cavia porcellus). In contrast to altricial rodents, energy acquisition and expenditure of guinea pig mothers (litter size, three) was highest during the first half of the 23-d lactation period. Daily metabolizable energy intake at peak lactation was increased by 126% above nonreproducing level and was 65% of the predicted maximal intake. Peak daily energy expenditure was 1.9 times basal metabolic rate, and resting energy expenditure was elevated 26% above nonreproductive level. From the third day, young consumed solid food and intake increased linearly over the course of lactation. During lactation, total intake of litters through solid food consumption (assuming efficient digestion) amounted to 86% of the energy intake that mothers allocated to reproduction during that period. The pattern of energy expenditure during lactation in guinea pigs differs substantially from that of altricial rodents and is made possible because pups contribute through solid food intake. Overall energy demand on the mothers is not much lower than in altricial rodents, but lower peak energy demand during lactation in guinea pigs may reduce the coupling of reproduction to periods of high food abundance.

Aging↗
PubMed1984

Serum folates during the reproductive cycle of sows.

In a first trial, serum folates concentration was measured in 105 sows randomly distributed into seven groups of 15 animals each. Each group represented one time period of the reproductive cycle: weaning, mating, 15, 30, 60, 90 and 110 d of gestation. The average serum folates concentrations for the different groups of sows were, expressed as ng/ml +/- SE, 99.5 +/- 8.9, 68.5 +/- 9.6, 63.9 +/- 7.4, 59.5 +/- 5.7, 39.6 +/- 5.7, 45.3 +/- 5.8 and 49.1 +/- 6.3, respectively. Results showed a biphasic decrease in serum folates levels, first at mating and then at 60 d of gestation. These results indicate a possible deficiency in serum folates during mid-gestation. In a second trial, 20 sows were assigned randomly to four groups of five animals each, representing four time periods of the reproductive cycle: weaning, mating, 30 and 60 d of gestation. One intramuscular injection of 15 mg folic acid was administered to all sows and serum folates concentration was measured before the injection and at 2-d intervals during a period of 14 d after the injection. An increase in serum folates was noted in sows of all groups. The time response curves observed after the injection are presented and discussed. The decrease in folates levels observed during early and mid-gestation could be moderated by im administration of this vitamin.

Animals↗
PubMed1990

Effects of feed restriction during the rearing period and age at photostimulation on the reproductive performance of turkey hens.

An experiment with Nicholas parent-stock turkey breeder hens was designed to determine the effects of feed restriction during the rearing period and age at photostimulation on reproductive performance. Hens reared on ad libitum intake of conventional corn-soybean diets (ad libitum), skip-1-day per week (skip-1-day), and 95% of ad libitum (95%) were placed into cages and photostimulated when they reached a target body weight of 10 kg or at the conventional age of 29 wk. A 3 x 2 factorial design was used, with five replicates of three hens for each treatment. All birds were fed for ad libitum access during the breeding period. More eggs were set from 95% birds than from ad libitum or skip-1-day birds (P less than .05); there was no difference between ad libitum and skip-1-day birds. Photostimulating based on 10 kg of BW versus 29 wk of age had no effect on total eggs set. There was no effect of rearing feed restriction on fertility or hatchability. Photostimulating based on 10 kg rather than 29 wk of age reduced fertility and hatchability (P less than .05). The results of this study indicate that optimum reproductive performance is attained by restricting the feed consumption of turkey breeder hens to 95% of ad libitum during the rearing period. No benefits were gained from photostimulating at 10 kg of BW versus 29 wk of age.

Age Factors↗
PubMed2000

Depression in women--issues in evaluation and management.

Depression is probably the most common psychiatric disorder in women. Women are a vulnerable group of depression due to psychological, social and biological factors. Marital relationships, social support, roles and self esteem are factors that contribute to depression. In addition, several periods in women's life relating to the reproductive cycle are periods of increased vulnerability. Management of depression in women should consist of detailed assessment of all the above factors. Drug treatment of depression in women requires an in depth understanding of pharmacokinetics of the drugs used and possible drug interactions. Treatment of depression in women should integrate both psychosocial and biological treatment modalities.

Antidepressive Agents↗
PubMedDate not supplied

[Stimulation of mouse encephalomyocarditis virus reproduction by non-multiplying poliomyelitis virus in several transplantable tissue culture lines].

Reproduction of mouse encephalomyocarditis virus (EMC) was studied in 5 continuous primate cell lines: HeLa, Fl, Detroit-6, P/7, and MIO inoculated with guanidine-dependent variant of poliomyelitis virus in the absence of guanidine. Poliomyelitis virus stimulated EMC virus reproduction in all cell lines under study. This stimulation effect was studied at length in HeLa and MIO cells. In HeLa cells, stimulation was observed at a low and moderate multiplicity of infection of EMC virus but not at a high (100 PEU/cell) multiplicity. Also, when EMC virus reproduction was stimulated, a shortening of the latent period of its multiplication cycle, an increase in the number of antigen-containing cells and the number of infectious centers were observed. In MIO cells, stimulation was found to occur both with low and high doses of EMC virus but not to be accompanied by a shortening in the latent period of EMC reproduction cycle, or any increase in the antigen-containing cells or number of infectious centers. In both cell types upon mixed infection the synthesis of virus-specific RNA's of EMC virus was enhanced. It is suggested that the stimulating effect of poliomyelitis virus is realized in HeLa and MIO cells at different stages of EMC virus reproduction.

Cell Line↗
PubMed1997

[Population parameters of three parasitoids (Hymenoptera: Scelionidae, Encyrtidae) hosted by the predator Podisus nigrispinus (Heteroptera: Pentatomidae)].

The reproductive parameters of Telenomus podisi, Trissolcus brochymenae (Hymenoptera: Scelionidae) and Ooencyrtus sp. (Hymenoptera: Encyrtidae) were studied for three generations on their natural host Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae). A parasitism rate of 10 eggs/day/species was used under laboratory conditions of 27 +/- 1 degrees C, 60 +/- 10% RH and 14 h of photophase. No significant differences were detected between generations in terms of net reproductive rate (Ro), intrinsic rate of natural increase (rm), generation time (T) and the effect of doubling time on population increase (DT). However, T. podisi and T. brochymenae had significantly higher Ro and rm values, and lower T and DT values, with rm 1.59 and 1.50 times higher than Ooencyrtus sp., respectively. In addition the former species also had shorter egg-adult period, greater longevity of females and reproduction period than the other species. These results confirm the greater reproductive potential of T. podisi and T. brochymenae, which are commonly found parasitizing P. nigrispinus.

Animals↗
PubMed1994

Effects of dietary vitamin E on sow reproductive performance over a five-parity period.

A study involving 360 farrowings over a five-parity period evaluated the effects of dietary vitamin E on sow reproductive performance and the subsequent effects on serum, colostrum, and milk tocopherol contents. The 2 x 3 split-split-plot experiment was conducted at two locations that differed in the type of facility (indoor gestation pens/farrowing crates [IP/FC] or outside gestation lots/indoor farrowing pens [OL/FP]) and three dietary levels of dl-alpha-tocopheryl acetate (22, 44, or 66 IU/kg of diet), with five parities nested within sow in a repeated measure design. Sow serum alpha-tocopherol, Se, and glutathione peroxidase (GSH-Px) activity were measured at 30 and 90 d postcoitum and at 21 d postpartum (weaning) during each parity. Colostrum and 7-, 14-, and 21-d milk samples were analyzed for alpha- and gamma-tocopherol and Se concentrations. Three pigs per litter were bled at weaning and their serum was analyzed for alpha-tocopherol and Se concentrations and GSH-Px activity. The results indicated that sow weights and daily lactation feed intakes or litter birth and weaning weights were not affected by dietary vitamin E levels provided to the sow. There was an increased number of pigs born (total, P < .01; live, P < .10) when dietary vitamin E was increased. The incidence of mastitis, metritis, and agalactia decreased (P < .05) as dietary vitamin E was increased. The incidence of mastitis, metritis, and agalactia decreased (P < .05) as dietary vitamin E increased was higher (P < .05) with first- and second-litter sows, and was higher (P < .01) at the location that had the OL/FP facility. Colostrum and milk alpha-tocopherol increased (P < .01) as dietary vitamin E increased. Milk alpha-tocopherol declined linearly (P < .01) from 7 to 21 d postpartum in a parallel manner between dietary vitamin E levels. At weaning, pig serum alpha-tocopherol increased (P < .01) as sow dietary vitamin E level increased. These results support a higher dietary level of vitamin E than currently recommended by NRC (1988) for both gestating and lactating sows.

Animals↗
PubMed2000

Moderate zinc-iron deprivation influences behavior but not growth in adolescent rhesus monkeys.

Primate species demonstrate a prolonged period of development before reproductive maturity that includes distinctive periods of rapid growth in the late fetal, late infancy and early adolescent stages. Rhesus monkeys resemble humans in this discontinuous pattern of growth and also in its relationship to brain development. Studies of zinc deprivation in rhesus monkeys have suggested an important relationship among growth rate, nutrient status and behavioral performance in infancy as well as adolescence. Recently, moderate combined zinc and iron deprivation (intake 0.2 mg Zn and 0.8 mg Fe/d, compared with control intake of 2.9 mg Zn and 1.7 mg Fe/d) during the adolescent growth spurt (29-32 mo. of age) of female rhesus monkeys (n = 8/group) was shown to influence behavior without affecting growth. Behavioral assessments included the Continuous Performance Test, the Delayed Nonmatch to Sample Test and activity (measured with an actimeter). The behavioral syndrome was characterized by reduced activity, reduced participation in behavioral testing and slower response. These changes could be reversed or prevented to some extent by altering the diet to include tablets of powdered beef (adding approximately 1.7 mg Zn and 0.7 mg Fe to daily intake). The study suggests that behavior may be sensitive to the quality of the diet available during the period of rapid adolescent growth and development.

Animals↗
PubMed2003

Different intervals between vasectomy and sperm retrieval interfere in the reproductive capacity from vasectomized men.

PURPOSE: To evaluate the relationship between the postvasectomy period and sperm reproductive capacity after ICSI. METHODS: Seventy-seven ICSI cycles with percutaneous epididymal sperm aspiration (PESA) were reviewed. Patients were divided into 4 groups according to the interval after vasectomy: 0 - 5 years (G1); 6 - 8 years (G2); 9 - 14 years (G3), and > 15 years (G4). RESULTS: Clinical and ongoing pregnancy rates did not correlate significantly with the time period of vasectomy until 14 years. Although the higher implantation rate observed in G1, no significant differences were noted among Groups 1-3. The miscarriage rates increased from G1 to G4, reaching a statistical significance among G1, G2, and G3 compared with G4. When groups were also divided according to the maternal age, the same results were obtained. CONCLUSIONS: The interval between the vasectomy and the sperm retrieval procedure has no effect on the outcome until the interval of 14 years.

Adult↗
PubMed2005

Metabolic variables and plasma leptin concentrations in dairy cows exhibiting reproductive cycle abnormalities identified through milk progesterone monitoring during the post partum period.

We have used milk progesterone analysis to monitor reproductive function in lactating dairy cows and have then related this reproductive function to a variety of metabolic variables. Monitoring of cows (n = 41) during the period of onset of luteal function (first milk progesterone reading>5 ng/ml) revealed that delayed onset was associated with increased milk yield and greater loss of body weight and body condition but was not related to plasma metabolite or leptin concentrations. Further monitoring of reproductive function in these 41 cows and an additional 33 cows (total n = 74) during the mating period (from weeks 6 to 14 post partum) identified reproductive cycle abnormalities in 29 (39.2% of animals). The occurrence of cycle abnormalities was associated with increased milk yield (P < 0.05), elevated plasma beta hydroxybutyrate (P < 0.05) and reduced plasma leptin (P < 0.01) concentrations as well as a lower (P < 0.05) rate of gain of body weight and condition score but was not associated with plasma urea or glucose concentrations. Furthermore, cows exhibiting cycle abnormalities had a longer (P < 0.01) interval to first service and a smaller percentage had conceived by 100 days post partum (34.5% versus 66.7%; P < 0.01). These results provide further evidence that impaired reproductive function during the post partum period in dairy cows is caused by a poor energy status and not elevated urea concentrations. Reduced plasma leptin concentrations in animals suffering reproductive dysfunction further supports this view.

3-Hydroxybutyric Acid↗
PubMed2000

Critical period for adverse effects on development of reproductive system in male offspring of rats given di-n-butyl phthalate during late pregnancy.

The objective of this study was to determine the susceptible days for the adverse effects of di-n-butyl phthalate (DBP) on development of reproductive system in male offspring following maternal administration on successive 3-day period during late pregnancy. Pregnant rats were given DBP by gastric intubation at 1000 or 1500 mg/kg on days 12-14 or 18-20 of pregnancy or at 500, 1000 or 1500 mg/kg on days 15-17 of pregnancy. A significant decrease in the maternal body weight gain and/or food consumption was found in the DBP-treated groups regardless of the days on which DBP at 1000 and 1500 mg/kg was given. A significant increase in the number of resorptions per litter was found in the groups given DBP at 1500 mg/kg on days 12-14 and 15-17 of pregnancy. The weights of male and female fetuses were significantly decreased in the groups given DBP at 1000 and 1500 mg/kg on days 12-14 and 18-20 and at 1500 mg/kg on days 15-17. A significant increase in the incidence of fetuses with undescended testes was found at 1500 mg/kg on days 12-14 and at all doses on days 15-17. A significant decrease in the anogenital distance (AGD) of male fetuses was observed in the groups treated with DBP regardless of the days of treatment. The AGD/body weight ratio in male fetuses was significantly reduced in the groups given DBP on days 15-17, but neither on days 12-14 nor 18-20. The AGD of female fetuses in the DBP-treated groups was comparable to that in the control group. It was concluded that period of days 15-17 of pregnancy was the most susceptible for DBP-induced undescended testes and decreased AGD in male offspring.

Animals↗
PubMed1990

Nocturnal illumination maintains reproductive function and simulates the period-lengthening effect of constant light in the mature male Djungarian hamster (Phodopus sungorus).

Mature male Djungarian hamsters (Phodopus sungorus) were placed in individual light-tight, sound attenuated chambers and exposed to one of four lighting conditions for a duration of approximately seven weeks. The four lighting conditions were: constant light (LL); constant dark (DD); feedback lighting (LDFB; a condition that illuminates the cage in response to locomotor activity); or a feedback lighting neighbor control (LDFB NC; the animal receives the same light pattern as a paired animal in feedback lighting, but has no control over it). Exposure of hamsters to LL or LDFB produced significantly and similarly longer free-running periods of the locomotor activity rhythm than exposure of animals to DD. Hamsters exposed to LDFB NC did not free-run or entrain, but rather displayed "relative coordination". The paired testes and sex accessory glands weights suggest that in the Djungarian hamster, LL and LDFB exposed animals maintained reproductive function, whereas DD exposed animals did not. Animals exposed to LDFB NC had intermediate paired testes weights. Since several previous studies have demonstrated that short pulses of light, which are coincident with the subjective night, are photostimulatory, it is not surprising that LDFB maintained reproductive function in the mature Djungarian hamster. Feedback lighting, however, has been shown to be an insufficient stimulus to maintain reproductive function of mature male and female Syrian hamsters, and to the reproductive maturation of immature Djungarian hamsters. The results suggest that there may be slight, but significant differences in the way these two species interpret photoperiod, as well as a developmental change in the photoperiodic response of Djungarian hamsters.

Activity Cycles↗
PubMed2006

Effects of the menstrual cycle on looking preferences for faces in female rhesus monkeys.

Fluctuations of ovarian hormones across the menstrual cycle influence a variety of social and cognitive behaviors in primates. For example, female rhesus monkeys exhibit heightened interest for males and increased agonistic interactions with other females during periods of high estrogen levels. In the present study, we hypothesized that females' preference for males during periods of high estrogen levels is also expressed at the level of face perception. We tested four intact females on two face-tasks involving neutral portraits of male and female rhesus monkeys, chimpanzees and humans. In the visual preference task (VP), monkeys had to touch a button to view a face image. The image remained on the screen as long as the button was touched, and the duration of pressing was taken as an index of the monkey's looking time for the face stimulus. In the Face-Delayed Recognition Span Test (Face-DRST), monkeys were rewarded for touching the new face in an increasing number of serially presented faces. Monkeys were tested 5 days a week across one menstrual cycle. Blood was collected every other day for analysis of estradiol and progesterone. Two of the four females were cycling at the time of testing. We did not find an influence of the cycle on Face-DRST, likely due to a floor effect. In the VP however, the two cycling individuals looked longer at conspecific male faces than female faces during the peri-ovulatory period of the cycle. Such effects were absent for human and chimpanzee faces and for the two noncycling subjects. These data suggest that ovarian hormones may influence females' preferences for specific faces, with heightened preference for male faces during the peri-ovulatory period of the cycle. Heightened interest for stimuli of significant reproductive relevance during periods of high conception risk may help guide social and sexual behavior in the rhesus monkey.

Animals↗