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At least 865 records · Page 48Linked to original sources
PubMed1984

The clinical relevance of the epidemiology of ovarian cancer.

This paper reviews some clinically relevant aspects of the epidemiology of ovarian cancer. The items presented and discussed are: (1) incidence and mortality data: they show substantial stability in all Western countries over the last few decades; (2) risk factors: the relationships with child-bearing patterns and other reproductive variables (age at menarche and at menopause; oral contraceptives) appear well established but no risk factor is sufficiently strong to be of practical value in prevention or early diagnosis: (3) long-term survival: in spite of the large number of clinical studies that have claimed 'more effective' treatments, no improvement of long-term survival in the population as a whole has been established. Some discrepancies and drawbacks in published trials are discussed, and a different approach towards clinical studies is suggested.

Adult↗
PubMed2004

Endocrine aspects in pathogenesis of mastitis in postpartum dairy cows.

In well-managed dairy herds some environmental pathogens including Gram-negative (GN) strains (E. coli and others) have been recognized recently as the predominant causative microbes of mastitis in the peri-parturient period. In early weeks of lactation hyperketonaemia may predispose the high-producing cows for GN mastitis. In GN mastitis cytokines, eicosanoids and oxygen radicals are released, which are responsible for the local and systemic symptoms. Experimental administration of endotoxin induces a complex endocrine cascade. Similar changes in plasma levels of cortisol, insulin, insulin-like growth factor-I and thyroid hormones are seen also in severe cases of GN mastitis. However, leptin is not responsible for the anorexia associated with severe mastitis in ruminants. Mastitis can postpone the resumption of ovarian cyclic activity in dairy cows when its outbreak occurs between days 15 and 28 after calving (at the expected time of first ovulation). In cyclic cows severe cases of GN mastitis can induce premature luteolysis or prolong the follicular phase.

Animals↗
PubMed2006

Relative importance of hydrocarbon pollutants, salinity and tidal height in colonization of oyster reefs.

The relative effects of hydrocarbon pollutants, salinity and tidal height on the invertebrates and fish that inhabit oyster reefs were studied along the Louisiana Gulf of Mexico coastline. Dried oyster shell (cultch) was first exposed to crude oil in the laboratory. In a series of experiments, plastic trays filled with control and oil-exposed cultch were then deployed at two locations differing in salinity, in two seasons and at two tidal levels. In experiments on hydrocarbon, salinity, and seasonal effects, trays were colonized for one month. To examine the effects of colonization time, half of the trays were retrieved after two and the rest after five weeks. Salinity dramatically affected oyster reef assemblages, with species richness and total abundance halved at the estuarine site. Hydrocarbon effects were less prominent, whether cultch was dosed with light or heavy crude oil. The sub-tidal site had higher colonization rates, but colonization interval did not affect colonization, and seasonal differences occurred only at the higher-diversity, sub-tidal site. To determine effects of cleaners, Corexit 9580 was applied alone and with oil on cultch, and trays were colonized for one month. At high concentrations, the cleaner ameliorated hydrocarbon effects. In general, hydrocarbon effects were less prominent than salinity and aerial exposure in explaining colonization of oyster reef assemblages. Gas chromatography/mass spectrometry analysis of oyster shells after one month immersion revealed considerable losses of oil, especially with higher flow at the inter-tidal site. Sediment on shell also diluted oil. We argue that oyster reef assemblages should recover from small-scale spills, unless they occur during periods of reproduction and dispersal.

Animals↗
PubMed2006

Increasing trend of spina bifida and decreasing birth weight in relation to declining body-mass index of young women in Japan.

We analyzed the existing data from various surveys on the prevalence of spina bifida, birth weight, and body-mass index (BMI), dietary intake, and smoking habits of Japanese young women. We found that the increasing trend of the prevalence of spina bifida paralleled with the decrease in birth weight, and the decrease in BMI and dietary energy intake and the increase in smoking rate among women of childbearing age. The decreased energy intake is likely due to their distorted self-body image. Based on these findings, we hypothesize that lowering BMI in young women led to increasing prevalence of spina bifida and smaller babies in Japan. This low dietary intake possibly leads to poor folate nutritional status, a risk factor for the development of spina bifida, and increased smoking potentially accelerates these undesirable outcomes. Our hypothesis can be tested using two simultaneous approaches. The first step is an extensive educational campaign for young women to stop smoking, have a realistic body image and eat a sufficient balanced diet. Government officials and health-care workers are encouraged to establish an agenda to educate young women with emphasis on the importance of adequate nutrition during the critical period of reproduction. Together with this campaign, the distribution of folic acid tablets for the prevention of spina bifida can be tried in women of childbearing age through local health centers, which have been well established in Japan.

Birth Weight↗
PubMed1995

Controlled ovarian hyperstimulation and transvaginal intratubal insemination as an alternative to gamete intrafallopian transfer.

OBJECTIVE: To evaluate the efficacy of controlled ovarian hyperstimulation (COH) followed by intratubal insemination in the treatment of infertility. DESIGN: Retrospective analysis of 179 intratubal insemination trials in 78 women over a 48-month period. SETTING: Reproductive endocrinology practice. PATIENTS: Seventy-eight women, 26 to 44 years old (34 +/- 4.3 years; mean +/- SD), classified into subgroups according to diagnosis and age (< 40 or > or = 40 years). INTERVENTIONS: Patients underwent COH and intratubal insemination. MAIN OUTCOME MEASURES: The rates of pregnancy, delivery, spontaneous abortion, ectopic and multiple gestation, and complications were studied and analyzed statistically. RESULTS: Overall, there were 36 pregnancies (20.1% of 179 trials), 29 deliveries (16.2%), 5 of 36 first trimester abortions (13.9%), 2 of 36 ectopic pregnancies (5.6%), and 4 twin gestations. There were no serious complications. In 43 women < 40 years without male factor the first trial resulted in 15 pregnancies (34.9%); in 27 women < 40 years with male factor the first trial resulted in 4 pregnancies (14.8%). Male factor reduced significantly the probability of conception. In 19 women < 40 years of age with either ovarian dysfunction or infertility of unknown cause, the first trial resulted in 9 pregnancies (47.4%), which was significantly better than the 10 pregnancies achieved in the first trial in the remaining 51 women < 40 years of age. Peak serum E2 levels and number of mature follicles had a significant effect on pregnancy rates. CONCLUSIONS: Intratubal insemination yielded pregnancy rates comparable to those published for GIFT at reduced cost and with fewer complications.

Adult↗
PubMed2001

Effects of maternal age on oocyte developmental competence.

The widespread use of a variety of assisted reproductive technologies has removed many of the constraints that previously restricted mammalian reproduction to the period between onset of puberty and reproductive senescence. In vitro embryo production systems now allow oocytes from very young animals to undergo fertilization and form embryos capable of development to normal offspring, albeit at somewhat reduced efficiencies compared to oocytes from adult females. They also can overcome infertility associated with advanced age of animals and women. This review examines oocyte developmental competence as the limiting factor in applications of assisted reproductive technologies for both juvenile and aged females. Age of oocyte donor is a significant factor influencing developmental competence of the oocyte. Age-related abnormalities of oocytes include a) meiotic incompetence or inability to complete meiotic maturation resulting in oocytes incapable of fertilization; b) errors in meiosis that can be compatible with fertilization but lead to genetic abnormalities that compromise embryo viability; and c) cytoplasmic deficiencies that are expressed at several stages of development before or after fertilization. In general, oocytes from juvenile donors and the embryos derived therefrom appear less robust and may be less tolerant to suboptimal handling and in vitro culture conditions than are adult oocytes. Research to identify specific cytoplasmic deficiencies of juvenile oocytes may enable modifications of culture conditions to correct such deficiencies and thus enhance developmental competence. Use of oocytes from aged donors for assisted reproduction can have a variety of applications such as extending the reproductive life of individual old females whose offspring still have high commercial value, and conservation of genetic resources such as rare breeds of livestock and endangered species. In general, female fertility decreases with advancing age. Studies of women in oocyte donation programs have established reduced oocyte competence as the major cause of declining fertility with age, although inadequate endometrial function can also be a contributing factor. Most research has emphasized the importance of chromosomal abnormalities because of the well established increase in aneuploidy with increasing maternal age but little is known about the underlying cellular and molecular mechanisms. Research aimed at identifying the specific developmental deficiencies of oocytes from juvenile donors and abnormalities of oocytes from aged females will assist in overcoming present bottlenecks that limit the efficiency of assisted reproduction technologies. Such research will also be crucial to the development of new oocyte-based technologies for overcoming infertility and possibly subverting chromosomal abnormalities in women approaching menopause.

Animals↗
PubMed2000

High-density lipoprotein associated with secondary vitellogenesis in the hemolymph of the crayfish Cherax quadricarinatus.

The high-density lipoproteins LPI and LPII were isolated from the hemolymph of the crayfish Cherax quadricarinatus by gradient ultracentrifugation and high-performance liquid chromatography (HPLC). Both lipoproteins contained a carotenoid moiety. LPI is comprised of a single polypeptide with an approximate molecular mass of 96 kDa. LPII was composed of two similar native components, LPIIa and LPIIb, both having polypeptides of 80 and 177 kDa. Both under natural conditions and after endocrine manipulations, LPI was present in males and in females, regardless of the female reproductive stage. LPII was present only in secondary-vitellogenic females, but not during the winter reproductive arrest period. LPII was also absent from young females that had received androgenic gland implants. LPII also appeared in the hemolymph of intersex individuals from which the androgenic gland had been removed. It is therefore suggested that LPII serves as a marker indicating the onset of secondary vitellogenesis in C. quad'iariicarintus females.

Animals↗
PubMed1998

A Japanese view on a global toxicology testing program before ICH1 and after ICH4.

Many unharmonized points on the toxicological evaluation on pharmaceuticals have been solved by the discussion for 8 years in the ICH. The following issues are representative ones in which the Japanese view on a toxicology testing program after ICH4 is different from that before ICH1: (1) a new guideline and pre-mating treatment period in reproductive toxicity; (2) 9-month chronic studies for non-rodent species; (3) a new guideline of toxicokinetics; and (4) selection of high dose levels and a new guideline using short-term alternative tests in carcinogenicity. Hazard evaluation of pharmaceuticals to man in toxicological studies in Japan before ICH1 has been conducted on the basis of the traditional toxicological evaluation. After ICH4, in line with the ICH strategy, Japan will adopt the analytical/integrative toxicological evaluation taking into account the 'weight of evidence' approach, exposures of the test drug and species differences between experimental animals and humans. However, since there still remain many things that need to be clarified for the better understanding of the guidelines, Japan should take more flexible regulatory approaches for the evaluation.

Animals↗
PubMed2002

[Heterozygosity and selective value: the case of the marine fish, Diplodus sargus (Linné, 1758)].

A total of 842 white sea bream (Diplodus sargus), sampled in Banyuls-sur-Mer, were analysed to test 'genotype-phenotype' relationship for various characters related to the fitness. The results show significant differences (MLH and FIS) for the age according to the sex between females carrying out and not carrying out sexual inversion. This suggests an overdominance for old females and a genetic sex determination. The individuals laying very early during the period of reproduction are also differentiated from the individuals reproducing later in the season. These results suggest either a stable calendar of laying in time separating the individuals genetically reproducing precociously from the others and this by differential selection and/or genetic drift either a Wahlund effect among cohorts.

Animals↗
PubMed1989

Menarche, menopause and reproduction in the Kipsigis of Kenya.

Among the Kipsigis, a population of south-western Kenya who do not use contraception, age at menarche and age at last live birth could be determined for a cohort of post-menopausal women, through reference to clitoridectomy ceremonies that can easily be dated. While a woman's age at last live birth was strongly associated with the length of her reproductive lifespan, completed family size was better predicted by age at menarche. The demographic implications of variation in menarcheal age are discussed.

Adolescent↗
PubMed1993

Marriage, age at last birth and fertility in a traditional Moroccan population.

A sample of 842 rural women from Morocco (Amizmiz, Marrakech) was used to examine the relationship between a number of biosocial variables and fertility patterns. For women still in their reproductive years there were significant correlations between family size and woman's age, age at marriage and years of marriage. Among women with completed families, those with early age at marriage ceased childbearing about 10 years before reaching menopause, while women who married later continued to bear children until the end of their fertile life.

Adolescent↗