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PubMed1990

Excretion of porcine parvovirus through the genital tract of boars.

The putative binding of porcine parvovirus (PPV) to semen components in vitro was examined along with the shedding pattern of PPV in oronasally infected boars. Porcine parvovirus DNA was determined to be bound to spermatozoa that had been incubated in vitro with PPV and washed to remove loosely adherent virus. To determine whether PPV was shed in the semen, four 8-month-old boars, seronegative for PPV, were inoculated oronasally with a virulent strain of PPV. Prior to virus inoculation, a catheter was surgically implanted in the vas deferens for the purpose of collecting cauda epididymal semen free of extrinsic contamination. Epididymal semen specimens were collected prior to inoculation and daily thereafter for 21 days. A fifth boar was inoculated oronasally with PPV, but semen was collected by electroejaculation twice weekly for an equal period of time. Reproductive glands and semen specimens from all boars were examined by nucleic acid hybridization for the presence of viral DNA. All boars seroconverted to PPV, as evidenced by serum antibody titers ranging from 512 to 8,192 hemagglutinating inhibition units/50 microliters. Porcine parvovirus DNA was detected in epididymal semen of 3 of 4 catheterized boars on postinoculation days 5 through 9, but not in semen obtained by electroejaculation. Viral DNA was consistently detected in tissue samples collected on postinoculation days 8 and 21 from the scrotal lymph nodes (4 of 5 boars) and epididymides (3 of 5 boars).

Animals↗

PubMedDate not supplied

[Hypogonadotropic hypogonadism combined with anosmia (Kallmann's syndrome)].

Diagnosis in Kallmann's syndrome is often erroneous and results in the administration of inadequate therapy. The aim of the study was to define characteristic features of a course of disease and to administer adequate therapy. It has been established that cases of Kallmann's syndrome are rather frequent. Patients with hypogonadism should be examined with respect to anosmia because such a combination suggests the diagnosis of Kallmann's syndrome. The selection of a therapeutic method should be strictly individual bearing in mind a degree of hypoplasia and the presence of cryptorchism. In the combination of Kallmann's syndrome with cryptorchism CG therapy results in the elimination of cryptorchism without surgery in most patients. Chorionic gonadotropin should be administered in combination with androgens in marked testicular hypoplasia in any period at the reproductive age; later on it can be only chorionic gonadotropin. Correct diagnosis and adequate therapy lead to sex and social rehabilitation of patients with Kallmann's syndrome decreasing the number of sterile men.

Adolescent↗

PubMedDate not supplied

Testing strategies in behavioral teratology: I. Testing battery approach.

Female rats were given drinking water containing 1.5, 5 or 15 mg/l methylmercury chloride from two weeks prior to pairing until the end of the lactation period. The usual reproduction parameters were recorded. The morphological, functional and behavioral development of the offspring was assessed by subjecting them to a routine testing battery in accordance with the English and Japanese guidelines. Due to toxic effects in the high dose group only offspring of the mid and low dose groups were tested. In both groups some motor coordination and learning deficits as well as delayed sexual maturation were noted, although effects were small and varied considerably. Results demonstrated that a routine testing battery can detect behavioral effects in the offspring at a dose where no reproduction effects are observed.

Animals↗

PubMed1986

Use of ammonium tetrathiomolybdate in the treatment of copper poisoning in sheep.

Intravenous administration of ammonium tetrathiomolybdate (three doses on alternate days) appeared to be an effective means of containing the acute phase of copper toxicity in sheep, whether this arose from continuous ingestion of high copper feeds or by injudicious use of copper preparations for the control of copper deficiency. No adverse effects were recorded on lamb numbers, birth weight or survival of lambs born to ewes of normal to low copper status when the treatment was applied at sensitive periods of the reproductive cycle. Decreases in 'available' plasma copper and in liver damage occurred rapidly in response to intravenous tetrathiomolybdate and it is suggested that all animals at risk be treated.

Animals↗

PubMed1980

[Steroid balance in breast cancers of varying histological structure].

Patients with breast cancer in stage I--II of various histological structure showed varied hormonal disturbances. In adenocarcinoma a high level of classic estrogens or total phenolsteroids was noted. In low differentiated cancers (solid, scirrhus) the values of estrogens excretion were considerably lower, but, if correlated with other hormones (androsterone), a relative hyperestrogenization is observed. Scirrhous cancers are characterized by the increased 17-ketogenic steroids excretion. The character of hormonal disturbances concomitant with the predominant development of certain breast tumor structures (adenocarcinoma, solid cancer, scirrhus) is identical for the patients being in their reproductive and menopausal period.

17-Ketosteroids↗

PubMed1983

Aspects of copulatory behavior and peptide control of egg laying in Aplysia.

The atrial gland of the marine mollusc Aplysia is associated with the large hermaphroditic duct of the reproductive system and contains several peptides capable of inducing egg laying. The structure and function of these peptides are briefly reviewed. It has been hypothesized that during copulation the atrial gland of the female is stimulated by penile insertion to release its peptides, which in turn initiate events leading to egg deposition. To test this hypothesis we monitored reproductive activity over periods of weeks in individual, paired, and grouped A. brasiliana. It was found that copulation is not a necessary stimulus for egg laying, because individually housed Aplysia lay more eggs than when they are paired and allowed to copulate. Nor is copulation a sufficient stimulus, because the vast majority of copulations are not followed by egg laying. Simultaneous egg laying and female copulatory behavior were often observed with grouped and paired animals, but these events are probably not causally related. It is concluded that although the atrial gland contains at least three peptides that can induce egg laying, stimulation of this gland during copulation does not normally serve to initiate egg laying.

Amino Acid Sequence↗

PubMedDate not supplied

[Dynamics of the urinary excretion of estrogens, pregnanediol, 17-ketosteroid fractions, cortisol and its metabolites in healthy women in the course of the menstrual cycle].

The 24-hour urinary estrogen excretion was studied in 12 women of reproductive age at periods corresponding to the middle and the end of the follicular phase, the middle and the end of the lutein phase of the menstrual cycle; pregnandiol excretion was determined at the same periods in 20 women, the urinary sum total and individual 17-KS content--in 26 women, free cortizol and its metabolites--in 19 women. The 24-hour estrogen excretion reached the maximum on the days corresponding to the ovulation peak (the 14th-15th days), and remained at a sufficiently high level in the middle of the lutein phase. Pregnandiol excretion increased by the end of the folliculin phase and reached the maximum during the lutein phase. During the mentioned most active periods of the menstrual cycle there was also noted a significant elevation of androstendione, androsterone, ethiocholanolone and free hydrocortizone excretion. The absolute amount and relative content of dehydroepiandrosterone in the sum total fractions of the urinary 17-ketosteroids proved to diminish. Cortizol metabolite excretion decreased as well. A regular direction of the changes occurring in the 24-hour excretion of individual 17-KS fractions, cortizol and its metabolites in the course of the menstrual cycle was apparently associated with the synthesis and transformation of sex hormones.

17-Ketosteroids↗

PubMed1998

Guidelines for the medical surveillance of shift workers.

Occupational health physicians should evaluate workers' fitness for shift and night work before their assignment, at regular intervals, and in cases of health problems connected with night work. The evaluation should be accompanied by a careful job analysis to ensure that shift schedules are arranged according to ergonomic criteria. This arrangement can reduce health problems and make coping with irregular workhours possible, even for people suffering from contraindicative illnesses. Both health disorders representing absolute or relative contraindication and actual work conditions should be taken into account. Health checks should be aimed at detecting early signs of intolerance, such as sleeping and digestive trouble, drug consumption, accidents, and reproductive function. Their periodicity should be set in relation to specific work conditions, individual characteristics, and social factors known to influence tolerance to shift work. Shift workers should receive clear information on the possible negative effect of shift work, and also counseling for coping with shift and night work.

Counseling↗

PubMed1990

A circannual cycle in pinealocyte synaptic ribbons in the hibernating and seasonally reproductive 13-lined ground squirrel (Spermophilus tridecemlineatus).

Pinealocyte synaptic ribbons (SR) in the 13-lined ground squirrel were quantified at monthly intervals over a one-year period spanning the hibernating and reproductive cycles of these animals. SR numbers were high (70-90/20,000 microns2) during periods of activity and reproductive quiescence (May-October). With the onset of hibernation (November-December) there was a rapid 6 to 7-fold reduction in SR frequency. During arousal (January-February) and sexual maturation (March-April) there was a gradual increase in SR frequency. The winter decline in SR frequency is consistent with the decline in pineal melatonin during hibernation and supports the hypothesis that pinealocyte SR play an important role in the neurotransduction of melatonin biosynthesis.

Animals↗

PubMed2003

[Growth, reproductive function, and tolerance to load tests in rats under repetitive adverse conditions].

Wistar rats were subjected to a 3.5-day water deprivation once a month in the period of 1 to 10 months of age. The rats' adaptive abilities proved sufficient for compensation of adverse effects, the rats preserved their normal motor activity, emotionality, and orienting behaviour in the intervals between the effects. In the reproductive period, the males manifested a normal sexual behaviour and fertilizing capacity of their spermatozoids. In the end of the experiment, the experimental animals did not differ from the control animals.

Adaptation, Physiological↗

PubMed2000

Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 24). Testicular toxicity of boric acid after 2- and 4-week administration periods.

To assess whether or not male reproductive toxicity can be evaluated in a 2-week administration study, boric acid was administered daily by oral gavage to male Jcl:Wistar rats at dosage levels of 0, 300 and 500 mg/kg for 2 and 4 weeks, and the results obtained with the two different treatment schedules were compared. After a 2-week administration, decreased testis weights were observed in the 500 mg/kg group. Histopathologically, exfoliation of round spermatids, retention of step 19 spermatids and increased numbers of residual body-like structures in the seminiferous tubules and cell debris in the cranial epididymal ducts were observed in the 300 and 500 mg/kg groups. Distorted cytoplasmic lobes of step 19 spermatids, debris in the seminiferous tubules and focal atrophy of the seminiferous tubules with multinucleated giant cells formation and necrosis of spermatocytes were also observed in the 500 mg/kg group. After a 4-week administration, testis and epididymis weights were decreased in the 300 and 500 mg/kg groups. Histopathological changes in the 300 mg/kg group were similar to those found in the 300 and 500 mg/kg groups after a 2-week administration. Diffuse atrophy of the seminiferous tubules was additionally observed in the 500 mg/kg group. These results suggest that 2 weeks is a sufficient treatment period for the detection of the testicular toxicity caused by boric acid.

Administration, Oral↗

PubMed1981

The influence of early age mastectomy and unilateral ovariectomy on reproductive performance of the bovine.

The effects of mastectomy and unilateral ovariectomy and their interaction during the postpartum period were examined in 26 Angus heifers. At birth, the animals were assigned to a 2 x 2 factorial arrangement of treatments: mastectomy and unilateral ovariectomy, mastectomy, unilateral ovariectomy and unoperated suckled control. Surgeries were performed at approximately 2 months of age, and animals were observed through three consecutive postpartum intervals (PP1, PP2, and PP3). There were no significant influences of mastectomy or ovariectomy on age at puberty, age at first conception or services required for first conception. Mastectomy reduced the number of days from parturition to ovulation (PP1, 32.1 vs 52.5, P less than .01; PP2, 21.6 vs 59.9, P less than .01; PP3, 20.6 vs 46.7, P less than .01) The interval from parturition to first estrus was shorter for heifers in the mastectomized group (PP1, 45.3 vs 76.2, P less than .05; PP2, 28.7 vs 69.9, P less than .01; PP3, 32.4 vs 62.3, P less than .05) as was the interval from parturition to conception during PP2 (60.0 vs 104.9, P less than .05). The interval between calvings was shorter for heifers in the mastectomized group than for controls, but the difference was significant only between the second and third parturitions: 338.5 vs 399.2 (P less than .01). Mastectomy reduced the standard deviation for the interval between parturition 2 and parturition 3 (55.9 vs 15.9; P less than .01), the interval between parturition and return to estrus in PP2 (56.3 vs 11.4; P less than .01) and the interval from calving to conception PP1 (92.2 vs 31.4; P less than .01). Unilateral ovariectomy did not have a significant influence on any of the postpartum intervals, nor were there any significant interactions.

Age Factors↗

PubMed1988

Changes in maternal age distribution and their possible impact on demand for prenatal diagnostic services.

Between 1977 and 1985 there was a 65% increase in births to women aged 35 or more in England and Wales, but only a 15% increase in all births. Two factors of roughly equal importance were responsible for this differential increase. Firstly, the proportion of older women (35-44) among all women of reproductive age (15-44) increased from 28% in 1977 to 31% in 1985; and, secondly, in the same period the fertility rate for women aged 35-39 increased from 18.2 to 24.1 per 1000 and for women aged 40-44 from 4.1 to 4.6 per 1000. The increased fertility rate among older women is not due to an extension of the reproductive period but to a delay in childbearing. This delay was seen in women married only once and also in those who had remarried. As prenatal diagnosis for the exclusion of chromosome abnormalities is customarily offered to older mothers the increased numbers of women aged 35 or more and their increased fertility rate have important implications for the provision of obstetric and laboratory services. There were 51,859 live births to women aged 35 and over in 1985; the projected figure for 2001 is 85,000. If the use of prenatal diagnosis continues to increase facilities for about 70,000 prenatal cytogenetic analyses will be needed in 2001.

Adult↗

PubMed1988

Role of pineal and eyes in the regulation of ovarian activity and vitellogenin levels in the catfish exposed to continuous light or continuous darkness.

To investigate the relative importance of pineal and eyes in ovarian activity, catfish subjected to pinealectomy, binding, or both were exposed to continuous light (LL) or continuous darkness (DD) during the different phases of the annual reproductive cycle. Pineal or eyes have no influence on ovarian activity during the preparatory, prespawning, and spawning periods of the annual reproductive cycle under these photoregimes. However, the pineal accelerated ovarian activity under LL and DD during the postspawning period. Blinding alone has no effect on ovarian recrudescence under these regimes. However, combined surgery (blinded-pinealectomy) inhibited ovarian development under both these conditions, indicating that the pineal organ is more important than the eyes. Ovarian recrudescence occurred even in the absence of both pineal and eyes, indicating the involvement of extrapineal and extraocular photoreception in the regulation of reproductive activity in the catfish.

Animals↗

PubMed1997

A critical period for thyroid hormone action on seasonal changes in reproductive neuroendocrine function in the ewe.

Thyroid hormones are obligatory for the annually recurring termination of reproductive activity in a spectrum of seasonal breeders, including sheep. Previous studies involving thyroidectomy and T4 replacement have led to the hypothesis that, in the ewe, thyroid hormones are necessary only during a limited interval late in the breeding season for the neuroendocrine processes that cause the transition to anestrus. The present series of experiments tested this hypothesis by assessing the influence of thyroidectomy, with or without T4 replacement for specific durations and at different times of the year, on the transition to anestrus. Seasonal alterations in reproductive neuroendocrine activity were monitored by changes in serum LH concentration in ovariectomized ewes bearing s.c. SILASTIC brand silicon tubing implants containing estradiol. Thyroidectomy in mid-December, just before the putative period of thyroid hormone action, prevented the development of the neuroendocrine anestrous season (fall in LH in this animal model). T4 replacement for 90 days beginning in late December (i.e., during the postulated period of thyroid hormone action) overcame the blockade of anestrus, causing LH to fall in ewes thyroidectomized several months previously. The minimal effective duration of exposure to thyroid hormones required for the transition to anestrus was estimated to be 60-90 days. Further, exposure to T4 for 60-90 days beginning in late December was found to be the only time of the year that thyroid hormones were required to maintain seasonal changes in reproductive neuroendocrine activity. Finally, replacement of T4 for 90 days at a different time of year (beginning in August) failed to provoke development of neuroendocrine anestrus in thyroidectomized ewes. These results support the hypothesis that thyroid hormones are necessary only during a limited interval late in the breeding season to promote seasonal reproductive suppression in the ewe. Further, the reproductive neuroendocrine axis is not equally responsive to thyroid hormone at all times of the year. This suggests there is a critical period of responsiveness during which thyroid hormones must be present for anestrus to develop.

Anestrus↗

PubMed2005

Alpaca semen characteristics under free and directed mounts during a mating period.

Most studies in alpaca reproductive biology have been focused on female physiology. Only recent research is being conducted in order to increase the knowledge on males. Semen characteristics during breeding periods will contribute to understanding the poor fertility rates in alpaca. Ten adult male alpacas were distributed randomly into two groups and submitted alternatively to two regimens of semen collection of 12 days duration (day 1, initial day of semen collection). Semen samples were collected using an artificial vagina and a receptive, non-pregnant female. With regimen 1, males were maintained with females except for the days of sexual rest (6 and 7). Semen was collected on days 1, 5, 8 and 12. With regimen 2, males were exposed to females for daily semen collection only, before and after sexual rest. Mating duration, color and volume of ejaculates, spermatozoa concentration and morphology were evaluated. No statistical differences for the variables were found between regimens that were used for semen collection. With respect to influence of day, however, the total numbers of spermatozoa ejaculated on days 1 and 5 of semen collection were statistically different (p<0.05). Azoospermic samples increased on days 5 and 12 of semen collection. Partial recovery in spermatozoa concentration and number of spermatozoa ejaculated were observed after sexual rest. Although normal spermatozoa percentage was less on day 1 (p<0.05) as compared with values found in the following ejaculates (days 5 and 12), the total number of normal spermatozoa was greater. These results support the conclusion that when male alpaca have a daily ejaculation during five consecutive days, they might copulate without having enough spermatozoa for fertilization towards the end of the mating period.

Animals↗

PubMed2002

Role of feeding time and food amount in the reproduction of spotted Munia.

It was observed that food restriction significantly increase gonadal development for about two months indicating that hypothalamo hypophyseal gonadal axis becomes more sensitive to feeding stress during the early breeding period than the other reproductive phases. Normal testicular development was also not seen in the spotted munia in which food was restricted for two times each of 3 hour duration, despite the fact that daily food consumption was not significantly less (only by 6.60%) compared to the control group. This suggests that daily restriction in feeding for a longer period (total 6 h or more) may also alter the reproductive function in wild birds.

Animals↗

PubMed2005

Concentrations of cadmium, mercury and selenium in common eider ducks in the eastern Canadian arctic: influence of reproductive stage.

Concentrations and total organ content of mercury, selenium and cadmium, as well as liver, kidney and body mass were determined in female common eiders from 1997 to 2000 at the East Bay Migratory Bird Sanctuary in the eastern Canadian arctic. In 1997 and 1999, female eiders were collected during the pre-nesting period when they eat copious amounts of food and gain substantial weight in preparation for the rigours of nesting. In 1998 and 1999, female eiders were collected during the mid to late stages of the nesting period when they eat very little, if at all, and, as a consequence undergo dramatic weight loss. Total body mass, liver mass and kidney mass were highest in pre-nesting birds, especially in 1997. They were significantly lower in nesting birds collected in 1998 and 2000. In contrast, mercury and cadmium concentrations were lowest in pre-nesting birds collected in 1997 and 1999 and increased to significantly higher concentrations in nesting birds collected in 1998 and 2000. In contrast to these results, the total contents of mercury in liver and cadmium in kidney did not change significantly over the 4-year period. Hepatic selenium concentrations were relatively stable over the 4-year study period while changes in the total content of selenium in the liver paralleled changes in liver mass and body mass. The results suggest that mercury and cadmium concentrations in female common eiders change in response to normal changes in body and organ mass that occur during the reproductive period. Thus, it may be important to consider body condition or reproductive stage when using common eiders (and perhaps other species of sea ducks) in biomonitoring studies or when interpreting concentrations of metals in tissues in terms of the risk they pose to these ducks.

Animals↗