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PubMed1984

[Some components of preputial bacterial flora in the ram].

During the reproductive period the AA have carried on bacteriological researches in the preputial cavity in eight sardinian rams, without pathological processes, living in eight flocks in the country around Sassari, in order to detect the bacteriological flora. This flora could interfere both with fertility and with conservation of seminal material for artificial insemination. Three withdrawals have been carried on before, during and after the reproduction season. E.coli, P. mirabilis, Staph. epidermidis have been found in the varius examined subjects. The AA stress that the same bacterium which had been isolated in the first withdrawal. Moreover in some subjects the bacteriological flora had increased. The AA stress how these data can be useful in order to control the flock fertility and in order to improve the technology of conservation of seminal material.

Animals↗

PubMed2005

Case-control study of risk factors for breast cancer in Nigerian women: a pilot study.

OBJECTIVE: To evaluate the risk factors for breast cancer among women in Midwestern and Southeastern Nigeria. DESIGN: A case control study. SETTING: University of Benin Teaching hospital, Benin City and University of Port Harcourt Teaching Hospital, Port Harcourt in Nigeria. SUBJECTS: Fifty one women with diagnosis of breast cancer and their age- and sex matched controls were included in the study. INTERVENTIONS: Data was collected during a 30 minute period after obtaining written informed consent using interviewer-administered questionnaires. RESULTS: Parity > 4 (OR = 0.50, 95% Cl 0.17, 1.46) and duration of breast feeding > 60 months (OR = 0.58, 95% Cl 0.23, 1.48) were associated with reduced risk of breast cancer while birth order > 3 (OR = I.50, 95% Cl 0.25, 8.98), age at first full term pregnancy>20 years (OR = 2.50, 95% Cl 0.78, 7.97) and longer duration of reproductive period (OR = 1.25, 95% Cl 0.34, 4.66) were associated with increased risk of breast cancer. CONCLUSION: The study has shown that high parity and long duration of breastfeeding are associated with reduced risk while high birth order and late age at first full-term pregnancy are associated with increased risk of breast cancer.

Adult↗

PubMed1979

Age dependent changes in the sperm population and fertility in the male rat.

The entire reproductive tract was devoid of spermatozoa during the first 42 days of life. The first appearance of spermatozoa was detected in the caput epididymidis of 45-day old rats and in the cauda epididymidis of 52-day or older rats. The number of spermatozoa in the reproductive tract increased with age. The sperm population reached its maximum in the caput epididymidis by day-72 and in the caud epididymidis by day-100. These high levels were maintained beyond 450 days of age. Fifty-two day old male rats failed to impregnate the female. Although male rats of 62-500 days were able to sire litters, the peak reproductive period was found to be between days 100-270, during which the number of young per litter ranged between 11-16. Towards advanced age the litter size dropped to 8. The lower fertility in the males of advanced age might be due to a lower proportion of fertile spermatozoa, a change in the physiology of epididymis or an altered sperm transport in the reproductive tract.

Aging↗

PubMed1985

Circulating thyroid hormone concentrations in relation to seasonal events in the male Indian garden lizard, Calotes versicolor.

Circulating thyroxine (T4) and triiodothyronine (T3) were estimated by RIA in plasma samples of Calotes versicolor collected over a period of 28 months. Monthly observations on seasonal events, viz., molting, whole body O2 consumption, abdominal fat deposition, and testes weight were also made. Plasma T4 ranged from 0.16 to 4.63 ng/ml and T3 from 0 to 1.76 ng/ml during the course of the year. Peaks of T4 and T3 could be related with prehibernating (October/November) and posthibernating (March/April) periods, when scale shedding and O2 consumption were also enhanced. Maximum abdominal fat deposition was found in prehibernatory months (October/November). Thyroid hormone levels declined sharply with entry into hibernation. Abdominal fat deposits gradually decreased, being almost depleted by the end of hibernation. The gradual increase in thyroid hormone concentration in the later half of hibernation may be associated with increased lipolysis and preparation of the oncoming reproductive period. Although T4 and T3 profiles were apparently parallel, discrepancies were observed. Posthibernatory peak of T4 was maintained much longer than that of T3 which declined earlier. Also the rise in the prehibernatory T3 concentration was delayed as compared to that in T4.

Adipose Tissue↗

PubMed1994

A ten-year observation on experimental infection of periodic Brugia malayi in man.

This paper reports the results of 10 years of observations on the clinical manifestations, pathology and immunity to filariasis and aetiological biology of filariae in three volunteers (first author and his family members) who were inoculated experimentally with infective larvae of periodic Brugia malayi in 1981. The changes in clinical symptoms and signs were recorded systematically. Microfilariae were first detected at 41 and 46 weeks after inoculation in two subjects and remained detectable in small numbers until 8-8.5 years after infection. The microfilarial density fluctuated at 1-2 mf 120 microliters-1. Thereafter no microfilariae were detected in 12 blood sample examinations, suggesting that the adult reproductive period of periodic B. malayi could last up to 8-9 years in the human body. Eosinophilia occurred mainly before and at the initial stage of microfilaraemia. An increase in the lymphocytes was observed to some extent at 2-156 weeks after infection. Biopsy at the inoculation site 6 weeks after inoculation showed infiltration of the lymph node by inflammatory cells, mainly eosinocytes, lymphocytes and monocytes. Lymphangiectasis and lymphostasis were observed in both limbs and pelvic regions by lymphangiogram taken 11 weeks after inoculation. Antibodies against B. malayi first appeared at 2-5 weeks after infection, peaked at 12-56 weeks and thereafter declined gradually. Subjects A and C became antibody free but subject B remained positive to antibody against B. malayi 10 years after infection. E-rosette forming lymphocytes became lower than normal at 11 weeks and recovered to normal within 10 years after infection.

Adolescent↗

PubMed2004

Reflections on an unsolved problem of biology: the evolution of senescence and death.

The evolutionary theory of senescence is based largely on principles first outlined by Williams in 1957, and consists of two relatively independent parts. The first part builds on ideas first put forward by Medawar, Haldane and others, to explain how something as negative as senescence could have been positively selected in evolution, particularly since most animals in the wild do not reach an age where senescence is expressed. Williams proposed that the genes responsible for the negative effects of senecence (senescence effector genes) were fixed in evolution by a process he called antagonistic pleiotropy, wherein a subset of genes selected because they confer a reproductive advantage early in life may have harmful effects in the post-reproductive period; negative selection against these harmful effects fails because, as pointed out by Medawar, the force of natural selection declines with age. The evolutionary history of senescence-causing genes is seen as a nondirected accumulation of genes selected on a basis independent of senescence per se. In the second portion of his paper, Williams made a series of predictions about how the age of organisms at reproductive maturity, fecundity, lifespan and the timing of the onset of senescence would all interact in the life history of a species. These latter predictions, which do not depend at all on details of the mechanisms of selection of senescence effector genes, have been validated by numerous experiments over the past several decades. On the other hand, it has become increasingly evident that the senescence effector genes did not, as would be predicted by antagonistic pleiotropy, accumulate in a random, non-directed fashion in various species over evolutionary time. Rather, everything we know about these genes suggests they were present in eukaryotic founder cells shortly after, or even congruent with, the emergence of eukaryotes from their prokaryotic ancestors, and have been stringently conserved ever since. Complicated explanations of how so-called "death genes" may have evolved in eukaryotes are thus not required. It is suggested that the evolutionary theory of senescence should be focused on those evolutionary principles that have been validated experimentally, and that the notion of antagonistic pleiotropy--which cannot be experimentally validated--be dropped from our thinking about the evolution of senescence.

Aging↗

PubMed2004

[Cervical intraepithelial neoplasia (CIN) in Brazzaville, Congo. A situation analysis].

OBJECTIVE: To collect epidemiological data about Cervical Intra epithelial Neoplasia in Brazzaville, for planning strategic issues of a cancer screening programme in the Congo. METHODS: Retrospective study of the results of 5700 occasional cervical Pap smears. RESULTS: The majority of the recorded women were 21 to 30 years old (49%), with a single or multiple parity (83.20%), and with a low socio-economic status. Among the 3088 recorded pathological smears, 200 cases of CIN were identified predominantly in 20 to 29 year-old-patients. They were subdivided into 174 (87%) CIN I, and 26 (13%) CIN II and CIN III. On the same occasion, 88 invasive cancers have been observed, predominantly among 50 to 60 year-old-women; an interval of 10 years has thus been noted between the latest period when CIN occurred (30 to 39 years) and the period when most of invasive cancers came about. CONCLUSIONS: The interest of an organized national screening programme has thus been confirmed. The formulation of a national cancer strategic plan requests an updating of the present database with the results of additional epidemiological (cytological, virological) studies concerning hight-grade intraepithelial lesions, and by those of a national health system analysis concerning health of women in the post-reproductive period.

Adolescent↗

PubMed1986

Photoperiod, diet, and method of feeding on reproduction.

Effects of two lighting programs and three methods of feeding on semen production of Large White turkey males were investigated. Lighting programs of 14L:10D and 8L:16D were used during the reproduction period. The feeding programs consisted of: 1) a low protein ration (10% FF) containing 3,250 kcal ME/kg fed ad libitum, 2) a high protein ration (15% FF) fed ad libitum, and 3) a restricted intake high protein ration (15% R). The latter two diets contained 3,000 kcal ME/kg. Body weight, semen volume, and semen quality (sperm and seminal plasma protein concentrations) were measured weekly throughout the reproductive cycle from 26 to 52 weeks. There was no significant difference in the rate of weight gain of turkeys kept on 8L:16D and 15% FF from 16 to 52 weeks compared to those on 14L:10D and 15% FF. Decreasing protein from 15 to 10% and increasing energy levels of the diet decreased consumption significantly (P less than .05) from 16 to 52 weeks of age regardless of the light treatment. Mortality was lowest in the 10% FF and highest in the 15% R. Lighting treatment of 14L:10D significantly (P less than .05) increased semen volume and sperm concentration vs. the 8L:16D regimen. All the groups of males given 8L:16D had an endemic yellow semen syndrome (YSS) characterized by a combination of an elevated seminal plasma protein concentration (an average of 12.85 g/100 ml), abnormal spermatozoa, and numerous macrophages. Previous work is confirmed (Cecil, 1981) that low dietary protein can be used as a means of controlling body weight without any adverse effect on semen production or semen quality of Large White turkey breeder males.

Animals↗

PubMed1979

Evaluation of the body iron status of native Canadians.

The serum ferritin concentration was measured in 1417 Indians and 310 Inuit aged 1 to 89 years. The subjects were initially selected to produce a representative sample of the entire native population, but the rate of nonresponse was high, and the results reported in this paper are representative only of the people studied.In males the median serum ferritin values increased during early life and tended to plateau after the age of 30 years. In females the median values rose during childhood, tended to plateau during adolescence, increased slightly during the reproductive period, then gradually rose thereafter. Ranges of values were wide in all age groups, reflecting the variations in body iron stores. When compared with the Inuit, the Indians had a significantly higher prevalence of abnormal serum ferritin values.From an analysis of the serum ferritin values in Indians it is probable that iron stores were reduced in approximately 30% of children, 40% of adolescents, 34% of nonpregnant women of reproductive age, 11% of older women and 5% of adult males. The corresponding figures for the Inuit were 15%, 23%, 22%, 6% and 1%. In contrast, iron deficiency anemia was found in only 3% to 4% of native peoples. If "normality" requires more than small amounts of iron stores to meet physiologic needs, the results suggest a high probability of iron deficiency in 20% to 40% of native children, adolescents and nonpregnant women of reproductive age, and in 0% to 10% of other subjects; but if "normality" is defined as adequate iron stores for erythropoiesis the prevalence of iron deficiency was approximately 1% to 2% in children and adolescents, 3% to 5% in women and less than 1% in adult males.

Adolescent↗

PubMed1999

Life history of Eulemur fulvus rufus from 1988-1998 in southeastern Madagascar.

In this study, we compare the life-history patterns of male and female Eulemur fulvus rufus based on longitudinal data collected on individuals from two study groups from 1988-1998 in southeastern Madagascar. Mean group size was 9.5 individuals, and groups either contained more adult males than females or equal numbers of both sexes. Females reproduced for the first time between 2 and 4 years of age and reproduced each year, although the mean interbirth interval between surviving offspring was 2.1 years. An average of two adult females reproduced annually in each social group, and age and body weight may positively influence reproductive success. Females also appear to be philopatric but not female-bonded. Young natal males immigrated between 3 and 4.5 years of age and may join a new group within 612 months based on the age of emigrants. Once in a social group, they remained until old age, although a male's spatial position in the social group varied with age. Young nonnatal males were members of the social core and had the first opportunity to mate with all estrous females. Older males were peripheral to the social group and mated with females later in their cycle. We hypothesize that group size, the number of females in the group, and individual variation in reproductive success is influenced by several ecological conditions at this site: extreme variability in food availability during reproductive periods, the lack of large food patches, low plant species diversity, and small numbers of important aseasonal food sources such as Ficus species.

Animals↗

PubMed1983

Chronic toxicity of Dursban (chlorpyrifos) to the fathead minnow (Pimephales promelas) and the resultant acetylcholinesterase inhibition.

Fathead minnows (Pimephales promelas) were exposed to Dursban during a chronic toxicity test for 200 days including a reproductive period of their life cycle. The fish concentrated Dursban approximately 1700 times. Survival of first-generation fish was adversely affected at 2.68 micrograms/liter within 60 days. A significant increase in deformities occurred at 2.68 micrograms/liter within 30 days. Growth was significantly reduced at 2.68 micrograms/liter within 30 days and at 1.21 micrograms/liter by 60 days. Maturation of the first-generation fish was reduced at all Dursban exposures and reproduction was significantly reduced at 0.63 micrograms/liter and above. Growth and estimated biomass of 30-day-old second-generation fish were significantly reduced at 0.12 micrograms/liter, the lowest concentration tested. Brain acetylcholinesterase (AChE) activity was significantly inhibited at 0.27 micrograms/liter and above. AChE inhibition ranged from near 10% in fish exposed at 0.12 micrograms/liter to 89% for those exposed at 2.68 micrograms/liter. Inhibition results are compared to other results demonstrated during the chronic study. The use of exposure units (exposure concentration X exposure duration) is discussed as a tool for determining the effects of organophosphate pesticides on the environment.

Acetylcholinesterase↗

PubMed1997

Altered neuroendocrine control of GH secretion in normal women of advanced reproductive age.

BACKGROUND: Previous studies have suggested that the neuroendocrine control of growth hormone (GH) secretion changes with increasing age in women with normal menstrual cycles and sex steroid levels. METHODS: In order to verify this hypothesis, 8 younger (22-32 years) and 8 older (41-45 years) women with normal menstrual function and gonadal steroid levels were tested with the serotonergic agent sumatriptan (6 mg in a subcutaneous bolus), the GABAergic agonist sodium valproate (800 mg orally), the dopaminergic compound L-Dopa (500 mg orally) and placebos. Furthermore, all women were tested with GH-releasing hormone (GH-RH 1 microgram/kg body weight in an intravenous (i.v.) bolus) to determine whether GH secretion in response to its specific releasing factor was preserved. Serum GH levels were recorded over 2 hours in all tests and IGF-I levels in basal samples. RESULTS: Plasma IGF-I concentrations and the GH responses to sumatriptan, sodium valproate and L-Dopa were significantly lower in older than in younger women. Also, the GH-RH-induced GH response was significantly lower in older than in younger subjects. When peak GH responses to releasing stimuli were compared with age, significant negative correlations were found in all tests. CONCLUSIONS: These data did not show a specific neurotransmitter change underlying defective GH secretion in older aged reproductive women. On the other hand, the results indicated that age-related changes in the secretory machinery of GH, such as a reduced pituitary sensitivity to GH-RH and/or a reduction in the pituitary GH secretory capacity, affect women during the last years of the reproductive period.

Adult↗

PubMed1999

Ultrastructure and lectin cytochemistry of the cloacal ventral glands in the male newt Triturus marmoratus marmoratus.

Ventral glands are found in the cloacal walls of male urodele amphibians except for sirenids. These glands are mucous, and secrete substances that will form part of the spermatophore used in transfer of sperm during fertilization. Ventral glands are formed by secretory and ductal portions; both possess epithelial and myoepithelial cells with different characteristics. Urodeles have cyclic reproduction, and cloacal ventral glands show seasonal differences with electron microscopy. The glycoproteins secreted by these glands have been studied by means of lectin histochemistry. The labeling was detected mainly in the nuclei, rough endoplasmic reticulum, Golgi complex, and cytosol. Secretory granules in these glands are composed by mucous glycoproteins that bind PNA lectin (which binds galactose) and SBA and HPA lectins (N-acetylgalactosamine), UEA-I (fucose), and LcA (glucose and/or mannose). These findings suggest that the mucins secreted by ventral glands contain both N- and O-linked oligosaccharides. Ventral glands secrete higher quantity and more diverse mucous substances in the reproductive period, as confirmed by lectin-histochemical reactions. Based on these results, the major similarity between ventral cloacal glands and accessory mammalian glands, can be established with bulbourethral glands.

Animals↗

PubMed1994

Seasonal changes in plasma growth hormone and prolactin concentrations of the frog Rana esculenta.

Plasma growth hormone (GH), prolactin (PRL), and vitellogenin (VTG) concentrations were determined during the annual reproductive cycle of the frog Rana esculenta. Plasma GH and PRL were measured using a RIA that employed purified bullfrog (Rana catesbeiana) GH and PRL as standards and radioligand, and their respective antibodies. Using ELISA, plasma VTG titers were related to ovarian weight. GH, PRL, and VTG displayed different trends related to season and sex. In male frogs the GH and PRL trends have been found parallel, showing the highest concentrations (35 and 85 ng/ml, respectively) during the winter months. In the female frogs, the GH trend behaved differently from that in males; in fact, plasma GH changed during the annual reproductive cycle, showing two main peaks occurring during the reproductive period and the autumn ovarian recrudescence that are well correlated with the vitellogenesis as well as with the main changes in ovarian weight.

Animals↗

PubMed2005

Biochemical characteristics and sperm production of turkey semen in relation to strain and age of the males.

The effect of turkey strain [BUT (Big-6), Hybrid Large White (HLW), and Nicholas (N-700)] on semen quantitative parameters (ejaculate volume, sperm concentration, and total number of sperm) and biochemical parameters (seminal plasma protein concentration, acid phosphatase activity in spermatozoa and seminal plasma, and antiproteinase activity of seminal plasma) was investigated over the reproductive period. The Big-6 strain had better quantitative parameters of semen compared with HLW and N-700 strains. Besides protein concentration, the Big-6 strain had the highest level of acid phosphatase activity in semen and antiproteinase activity in seminal plasma. The N-700 strain was characterized by reduced quantitative parameters and the lowest levels of all biochemical parameters in semen. While quantitative parameters of semen showed very little trend over the 21 wk of the reproductive season, the biochemical parameters increased several fold. Biochemical parameters of semen seemed to be more affected than quantitative parameters by age of the males. These changes may be related to decreasing semen quality with increasing age of male turkeys.

Aging↗

PubMed1995

Male and female health problems in general practice: the differential impact of social position and social roles.

Sex, social position and social roles have been identified as important health predictors. Moreover, various social variables have been found to bear differently upon female as compared to male health. This study analyses data from a large-scale registration project in general practice (the Continuous Morbidity Registration), pertaining to the medical diagnoses of nearly 10,000 patients over a five year period. The effects of sex, social class, marital and parental status on a number of distinct categories of health problems were established, and a possible differential impact of social position and social roles on male and female health was explored. Categories of health problems studied were 'overall health problems', 'sex specific conditions', 'symptoms without disease', 'prevention and diagnostics' and 'trauma'. Sex and, above all, social class were identified as important predictors of most categories of health problems, especially during the reproductive period of life. Marital status and parental status did not contribute substantially to most types of health problems. Rates of prevention and diagnostics, sex specific conditions and total number of health problems could to a certain extent be predicted by the four sociodemographic variables, as opposed to trauma rates and symptoms without disease rates. Social class appeared the only variable with a substantially different effect on male vs female rates of sex specific conditions, prevention and diagnostics and trauma, but not so for overall health problems and symptoms without disease. Marital status and parental status did not differ significantly in their effect on male vs female health. Results illustrate that differentiation of the health variable into categories of health problems elucidates the relationship between sex, social variables and health.

Adolescent↗

PubMed1985

On the perpetuation of relic genes having an inviable homozygote.

Reproductive compensation may be prezygotic or postzygotic. Prezygotic compensation is the replacement of inviable infants by one or more additional births. When the marital fertility rates are greater than necessary to replace the parents, however, many traditional societies ensured that any surviving progeny in excess of two (on average) did not marry, or married only if they replaced an older sib as heir to the family estate. We call this postzygotic compensation. We show that the coefficient of biologically effective compensation approximates unity when normal and genetic-disease-affected sibships were both sufficiently large to ensure that, on average, two or more sibs survived to the end of the reproductive period, irrespective of the level of prezygotic compensation. The impact of these types of compensation on the population genetics of Tay-Sachs disease and cystic fibrosis is discussed.

Cystic Fibrosis↗

PubMed1992

Effects of ecdysteroids on reproductive physiology of Nippostrongylus brasiliensis (Nematoda) in vivo.

1. The influence of ecdysteroids (ecdysone and ecdysterone) was investigated on the control of reproduction in the parasitic nematode Nippostrongylus brasiliensis in vivo. 2. Infestive larvae (L3) were immersed in solutions of ecdysteroids (2.2 microM) at 37 degrees C for 4 hr before injection into the host. The effect on egg-laying was observed two stages later. 3. The treatment increased egg-laying, but had no influence on the timing of the reproductive period. The greatest effect was observed with ecdysone, ecdysterone only inducing a small and non-significant stimulation under our experimental conditions. 4. The physiological role of ecdysteroids in meiosis and gonadal development in nematodes is discussed.

Animals↗