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PubMed1983

[Forecasting cohort fertility rates by using an exponential function].

"Population forecasts based on cross sectional data do not allow for the variations in cohort fertility. In this paper methods are developed to fit cohort fertility rates by an exponential function. Out of a number of selected functions the Weibull-function shows the best fit. For predicting cohort fertility pattern the parameter values can be derived from the forecasts of a small number of demographic statistics." (summary in ENG)

Birth Rate↗
PubMed1997

Identification of sperm plasma membrane proteins exhibiting binding affinity for the ascidian egg coat.

In the initial stage of ascidian fertilization sequential sperm-egg coat interactions assure successful species-specific fertilization. Sperm recognize, bind to, and then penetrate the egg investment that consists of follicle cells (FC) and an acellular vitelline coat (VC). To identify plasma proteins that recognize the egg coat, a membrane fraction was prepared from Phallusia mammillata sperm using nitrogen cavitation followed by three centrifugation steps. The purity of the membrane fractions was assessed by transmission electron microscopy and marker enzymes. Comparison of the electrophoretic pattern of sperm extracellular membrane domains labeled by radio-iodination or biotinylation and recorded by autoradiography or enhanced chemiluminescence, respectively, showed the non-radioactive procedure to be a convenient and efficient method. Isolated sperm membrane components were found to inhibit fertilization in a concentration-dependent manner and to bind mainly to the FC. Eggs were used as an affinity matrix to determine which of the solubilized sperm membrane proteins possess egg-binding activity. Three biotinylated proteins (66 kDa, 120 kDa and 140 kDa) were found to bind to the VC. Assays probing heterospecific binding to Ascidia mentula eggs revealed that the 120 kDa protein possesses species-specific binding activity. Thus, the current data suggest the 120 kDa sperm membrane protein as a candidate adhesion molecule with a possible role in gamete binding and species-specific recognition in P. mammillata.

Animals↗
PubMed2004

Targeted expression of SHH affects chondrocyte differentiation, growth plate organization, and Sox9 expression.

UNLABELLED: The role of Hedgehogs (Hh) in murine skeletal development was studied by overexpressing human Sonic Hedgehog (SHH) in chondrocytes of transgenic mice using the collagen II promoter/enhancer. Overexpression caused a lethal craniorachischisis with major alterations in long bones because of defects in chondrocyte differentiation. INTRODUCTION: Hedgehogs (Hhs) are a family of secreted polypeptides that play important roles in vertebrate development, controlling many critical steps of cell differentiation and patterning. Skeletal development is affected in many different ways by Hhs. Genetic defects and anomalies of Hhs signaling pathways cause severe abnormalities in the appendicular, axial, and cranial skeleton in man and other vertebrates. MATERIALS AND METHODS: Genetic manipulation of mouse embryos was used to study in vivo the function of SHH in skeletal development. By DNA microinjection into pronuclei of fertilized oocytes, we have generated transgenic mice that express SHH specifically in chondrocytes using the cartilage-specific collagen II promoter/enhancer. Transgenic skeletal development was studied at different embryonic stages by histology. The expression pattern of specific chondrocyte molecules was studied by immunohistochemistry and in situ hybridization. RESULTS: Transgenic mice died at birth with severe craniorachischisis and other skeletal defects in ribs, sternum, and long bones. Detailed analysis of long bones showed that chondrocyte differentiation was blocked at prehypertrophic stages, hindering endochondral ossification and trabecular bone formation, with specific defects in different limb segments. The growth plate was highly disorganized in the tibia and was completely absent in the femur and humerus, leading to skeletal elements entirely made of cartilage surrounded by a thin layer of bone. In this cartilage, chondrocytes maintained a columnar organization that was perpendicular to the bone longitudinal axis and directed toward its outer surface. The expression of SHH receptor, Patched-1 (Ptc1), was greatly increased in all cartilage, as well as the expression of parathyroid hormone-related protein (PTHrP) at the articular surface; while the expression of Indian Hedgehog (Ihh), another member of Hh family that controls the rate of chondrocyte maturation, was greatly reduced and restricted to the displaced chondrocyte columns. Transgenic mice also revealed the ability of SHH to upregulate the expression of Sox9, a major transcription factor implicated in chondrocyte-specific gene expression, in vivo and in vitro, acting through the proximal 6.8-kb-long Sox9 promoter. CONCLUSION: Transgenic mice show that continuous expression of SHH in chondrocytes interferes with cell differentiation and growth plate organization and induces high levels and diffuse expression of Sox9 in cartilaginous bones.

Animals↗
PubMed1990

Determinants of contraceptive switching behavior in rural Sri Lanka.

This study examines the influence of a selected set of determinants of contraceptive method switching in rural Sri Lanka. Of interest is the question of how change in contraceptive practice at the individual level can account for patterns observed at the aggregate level. Based on calendar data on contraceptive use over a 3-year period, collected for more than 3,000 married women in a 1986 survey, the multivariate analysis shows that women who attain all or a significant proportion of their desired fertility tend to switch to more effective methods. Women who experience method failure tend to switch methods, usually to a type that is more effective. The woman's background determinants of age and education have small but significant effects on method switching, whereas the effect of household economic well-being is not significant. There is strong indication that rural couples are practicing contraception in a nonrandom fashion, switching methods in accordance with changes in their fertility motivations and contraceptive experience.

Choice Behavior↗
PubMed2026

Expression profiles of miRNAs in ruminant intermediate hosts with cystic echinococcosis.

Cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus sensu lato (s.l.), is a parasitic zoonotic disease recognized by the World Health Organization as a neglected tropical disease of significant public health concern. Despite ongoing control programs, CE remains endemic, underlining the need for integrated control strategies that involve new diagnostic and therapeutic tools. Recent investigations have spotlighted microRNAs (miRNAs) as key regulators in parasite development, immunomodulation, and as potential diagnostic and therapeutic targets. In the present research, a molecular study was conducted to investigate hydatid cyst samples (protoscoleces and germinal membranes) collected in southern Italy from different ruminant species (sheep, cattle, and water buffaloes), naturally infected with CE, with the ultimate goal of establishing a more comprehensive picture of miRNA expression patterns in these intermediate hosts. The bioinformatic analysis of hydatid cyst samples revealed 168 mature miRNAs. Among these, egr-miR-10-5p, egr-let-7-5p, and egr-miR-71-5p were the most abundant, with egr-miR-10-5p showing particularly high expression levels. No significant differences in miRNA abundance between host species were found. In contrast, when focusing on the comparison between protoscoleces and sterile germinal membranes, 24 miRNAs were found to be differentially expressed. Targeted qPCR of four selected miRNAs (egr-miR-71-5p, egr-let-7-5p, egr-miR-125-5p, and egr-miR-10-5p) showed clear overexpression in protoscoleces and in fertile germinal membranes compared with sterile ones. The differential miRNA expression patterns provide insight into the molecular mechanisms controlling the parasite's lifecycle and may guide the development of novel intervention methods to enhance CE control in endemic areas.

Animals↗
PubMed2005

Evaluation of endometrial receptivity during in-vitro fertilization using three-dimensional power Doppler ultrasound.

OBJECTIVE: To compare sonographic endometrial characteristics in in-vitro fertilization (IVF) cycles between women who conceive and those who do not. METHODS: Thirty-five women undergoing IVF treatment participated in the study. Using three-dimensional (3D) power Doppler ultrasound, we assessed endometrial patterns, volume and vascularization, after follicle stimulating hormone (FSH) stimulation but before human chorionic gonadotropin (hCG) administration (referred to hereafter as 'after FSH stimulation') and again on the day of oocyte retrieval. RESULTS: The pregnancy rate was 37% (13/35). After FSH stimulation, 29 of the 35 women had a triple-line endometrial pattern, compared with five out of 35 on the day of oocyte retrieval. In those who had a triple-line pattern after FSH stimulation the pregnancy rate was 44.8% (13/29) and it was 0% (0/6) in those with a homogeneous pattern (chi-square test, P = 0.039). If a triple-line pattern was present on the day of oocyte retrieval the pregnancy rate was 80.0% (4/5), whereas if the pattern was homogeneous the pregnancy rate was 30.0% (9/30) (P = 0.032). There were no differences between those who conceived and those who did not in endometrial thickness, volume or vascularization on either day examined. Endometrial volume decreased significantly after hCG injection in women who conceived, but not in those who did not conceive. In both groups endometrial and subendometrial vascularization decreased after hCG injection, while the endometrial thickness remained unchanged. CONCLUSIONS: The existence of a homogeneous endometrial pattern after FSH stimulation seems to be a prognostic sign of an adverse outcome in IVF, while a triple-line pattern after FSH stimulation and a decrease in endometrial volume appear to be associated with conception.

Adult↗
PubMed1999

Pushing the frontiers of science--the WHO/Rockefeller Foundation Initiative on implantation.

One approach to fertility regulation for which there is still a large unmet need is a once-a-month method that can be taken at the end of the luteal phase as a menses-inducer. Such a method would have a number of logistical and economic advantages for many women over other currently available methods. However, to be acceptable, menses-inducers of this type must not produce disturbances in subsequent menstrual cycles that would lead to unpredictable menstrual patterns or advance or delay subsequent ovulations. A number of structural and functional factors associated with the cyclical development and demise of the endometrium and corpus luteum in fertile and infertile women have been identified and the opportunity is now presented for interfering with implantation by disrupting the function of these factors at the local level in these tissues without systemic involvement or prolonged activity. The Rockefeller Foundation and WHO are supporting six centers and investigators around the world, as an international collaborative research initiative, to investigate the molecular biology of these factors and the effect on fertility of their manipulation. It is intended that promising leads identified and selected in this way will be developed into new products with industry.

Cooperative Behavior↗
PubMed2000

[Sexually transmitted diseases in adolescence].

BACKGROUND: Sexually transmitted diseases (STD) have their most incidence in adolescence. We conducted an observational study on the symptomatic patients of our STD's office to evaluate epidemiological distribution, behavioral patterns and diffusion of genital infections in teen-agers in respect of the adult population. METHODS: From april 1996 to april 1999 we studied two groups of patients: 54 teen-agers (13-19 years) and 917 women in fertile age (20-40 years). All the patients underwent to a clinical and microbiological examination of vaginal secretions (Gram slide, wet mount, cultures for bacteria, yeasts, eventually Chlamydia trachomatis, Mycoplasma spp, Neisseria gonorrhoeae, Herpes simplex virus--HSV--) and to an anamnestic and socio-epidemiological questionnaire. RESULTS: The more frequent genital infections among adolescents was vulvovaginal candidiasis (35% vs. 23.9% of adult people). HSV was found in 1.8% of teen-agers (vs. 0.6%) and when requested, Chlamydia trachomatis and mycoplasmas was found respectively in 16.6% (vs. 1.1%) and 50% (vs. 28%) in adolescents. We observed a high percentage of pregnancy (22.2%) of voluntary pregnancy interruption (41.6%) and a specific sexual behavior among teenagers. CONCLUSIONS: Our data show a particular behavioral risk pattern in the adolescence population and indicate the necessity of a serious program of prevention and sexual education that allow young people to live with more consciousness and safety their sexuality.

Adolescent↗
PubMed1998

A lineal equation for the classification of progressive and hyperactive spermatozoa.

Capacitation of spermatozoa, a complex sequence of events that render them able to fertilize the egg, is generally associated with a switch from lineal, progressive movement to a vigorous, non-progressive pattern characterized by starlike tracks, a process known as hyperactivation. Development of a method for the analysis of progressive and hyperactive tracks is thus important for the assessment of capacitation in biochemical, physiological and clinical studies. In this study, we have applied a two-step heuristic model to deduce a lineal equation that discriminates hyperactive from progressive spermatozoa. The kinetic parameters (curvilinear velocity (VCL), linearity (LIN), amplitude of lateral head displacement (ALH), straightness (STR), wobble (WOB), mean 'dance' (DAN) and velocity of the average path (VAP)) of ram spermatozoa were evaluated with a computerized motility analyzer, and classified one by one as progressive or hyperactive by the appearance of their tracks. In a first step, a discriminating plane was defined by minimizing the number of misclassified spermatozoa ('conflicting points'); then, the plane was adjusted by an iterative process to minimize the distance from conflicting points to it. The resulting plane showed a discriminating capacity of over 95% for both classes, higher than that achieved by setting a threshold value for the parameters taken separately or in group. When included in a standard semen analysis, application of the equation allowed a rapid assessment of the percentage of hyperactive spermatozoa. The method described, developed in ram spermatozoa, can be applied to different species for a variety of purposes.

Animals↗
PubMedDate not supplied

The population of a Wiltshire village in the nineteenth century: a reconstitution study of Berwick St James, 1841-71.

This paper reports an exploratory reconstruction of the village of Berwick St James in Wiltshire using nominative information from nineteenth-century English censuses and ecclesiastical registers of baptisms, marriages and burials between 1841 and 1871. The data are first described, and a procedure for sorting and linking records from different censuses, and for linking census records to registration records, is outlined. A detailed analysis of population turnover in the village reveals that after 1851 there was a period of heavy net out-migration. Those who left the parish were overwhelmingly young people, and females were more likely to move out than males: almost all the females born in the parish between 1841 and 1851 had moved away by 1871. A consequence of this pattern of out-migration was that by 1871 there was a shortage of females in the marriageable age-groups (15-29 years). It is clear that this method of reconstructing English village populations promises new insights into the demography of rural England in the nineteenth-century, including, in addition to population turnover and migration patterns, such aspects as fertility levels and trends. A number of problems with the technique remain, however, notably our ignorance of the typical length of the period between birth and baptism.

Demography↗
PubMed2003

Determinants of women's fertility in Oman.

OBJECTIVE: International studies have the inverse relationship of women education and empowerment on fertility. Our aim is to study the association of women education, and empowerment with some of the fertility determinants in a community based survey. METHODS: A cross sectional survey of the health status of the Omani community was designed. Face to face interviews with 2037 women, who were or had been married including demographic data, fertility patterns, family planning, 2 women empowerment indices (decision making and freedom of movement), and other modules reproductive health, were carried out during the year 2000. RESULTS: About 31% of the sample was considered highly empowered in decision making and the mean number of decisions taken in the household was 4.46 for the overall sample. For freedom of movement, 29% of the sample was highly empowered with a mean number of 3.88 for the overall sample. The mean values of both indices varied significantly according to age, residence, level of education and work status. Higher freedom of movement score women were more likely to have less number of children in the first 20 years of marriage. Women of higher score of decision making index were more likely to have longer closed birth interval Those scored low in the decision making index were more likely to get a child at an earlier age. CONCLUSION: There is inverse relationship between both education and empowerment and fertility. However, the 2 indices of women empowerment; decision making and freedom of movement were not always predicting the same fertility indicator, as women's empowerment is multidimensional in nature.

Adolescent↗
PubMed1999

A fiber-optic measurement system of light scattering to evaluate embryo viability: model experiment using a latex sphere suspension and mouse embryos.

In this study, we tested the efficacy of a fiber-optic light scattering system developed by us to measure mitochondrial size and particle density in embryos in order to establish a non-invasive method of evaluating human embryo viability for in vitro fertilization and embryo transfer. Particle size was determined by comparing the measured angular distribution of the light scattering intensity with that of the theoretical distribution using a 1.0 micron latex sphere suspension and mouse embryos. The measured light scattering pattern of the latex suspension was found to agree closely with the theoretically derived pattern. The measured light scattering pattern of the mouse embryo was similar to the calculated pattern of spheres, the diameter of which was equivalent to that of the mitochondria. Therefore, the measured light scattering is thought to be derived mainly from the mitochondria in the embryo. The relationship between light scattering intensity and latex particle density was also examined in order to estimate the detectable range of mitochondrial particle density. Since the detectable range of the particle density obtained in our study (1.4 x 10(6) - 1.4 x 10(11) particles/ml) was greater than the known mitochondrial particle density in human embryos (1.0 x 10(9) - 1.0 x 10(11) particles/ml), we believe that this mitochondrial particle density can be measured using our system. We concluded that it is possible to use our simple system as a non-invasive method for evaluating human embryo viability.

Animals↗
PubMed2001

Developmental expression of cytochrome P450 aromatase genes (CYP19a and CYP19b) in zebrafish fry (Danio rerio).

Cytochrome P450 aromatase (CYP19) is the terminal enzyme in the steroidogenic pathway that converts androgens (e.g., testosterone) into estrogens (e.g., estradiol). Regulation of this gene dictates the ratio of androgens to estrogens; therefore, appropriate expression of this enzyme is critical for reproduction as well as being pivotal in sex differentiation for most vertebrates. It is assumed that most vertebrates have a single CYP19 gene that is regulated by multiple tissue-specific promoter regions. However, the zebrafish (Danio rerio) has two genes (CYP19a and CYP19b), each encoding a significantly different protein and possessing its own regulatory mechanism. The primary purpose of this study was to determine the pattern of expression of each of the CYP19 genes in the developing zebrafish. A fluorescent-based method of real-time, quantitative RT-PCR provided the sensitivity and specificity to determine transcript abundance in single embryos/juveniles harvested at days 0 through 41 days post-fertilization (dpf), which encompasses the developmental events of sex determination and gonadal differentiation. CYP19 transcripts could be detected as early as 3 or 4 dpf, (CYP19a and CYP19b, respectively) and peak abundance was detected on day five. In general, the CYP19 genes differed significantly in the ontogeny of their expression. In most cases, the gonadal form of CYP19 (CYP19a) was more abundant than the brain form (CYP19b); however, unlike CYP19a, the pattern of CYP19b expression could be clearly segregated into two populations, suggesting an association with sex differentiation. Pharmacological steroids (ethinylestradiol and 17 alpha-methyltestosterone) enhanced the expression of the CYP19b gene at all three days examined (4, 6, and 10 dpf). These data suggest that the timely and appropriate expression of CYP19 is important in development and that the expression of CYP19b (the "extra-gonadal" form) may be associated with sexual differentiation if not sexual determination. J. Exp. Zool. 290:475-483, 2001.

Animals↗
PubMed1977

Experience with medroxyprogesterone acetate (Depo-Provera) as an injectable contraceptive.

Depo-Provera injections appear to be a safe and effective alternative for women who cannot tolerate the estrogenic side effects associated with oral contraceptives or the pain and bleeding associated with IUDs. However, women considering the method should be fully aware of the possible risks: (a) inability to withdraw the drug promptly in the event of a serious reaction, (b) disruption of menstrual patterns, and (c) delayed return of fertility after discontinuing therapy. Some women may consider the required trip to the doctor every 3 months an additional disadvantage. For women in developing countries where anemia and nutritional problems are prevalent, Depo-Provera has additional advantages in relation to IUDs and OCs: it causes less bleeding than IUDs or OCs and, unlike oral contraceptives, it does not suppress vitamin levels (4-8). Since it requires a trip to the doctor every 3 months, it also provides a better opportunity for medical supervision and care. For postpartum women who which to breastfeed their babies, Depo-Provera has the additional advantage of causing no adverse effect on lactation (1, 2, 13, 14, 16, 18, 19, 25, 32, 36).

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Plasma lipids during pregnancy in women in Port Harcourt, Nigeria.

BACKGROUND: Pregnancy in Caucasian women is known to be associated with hyperlipidaemia. In a background of poor socio-economic conditions, early marriage, poor acceptance of contraceptives, poor spacing of pregnancies, high fertility rate and poor maternal and child health indices, this study was designed to investigate the pattern and degree of serum lipid changes during pregnancy in black African women in Port Harcourt, Nigeria. METHODS: Two hundred and thirty apparently healthy pregnant women at different stages of pregnancy and 51 non-pregnant control subjects of comparable age, height, and parity were serially recruited into the study. Plasma total cholesterol (TCHOL), LDL-Cholesterol (LDL-CHOL), HDL-Cholesterol (HDL-CHOL) and triglycerides (TG) were estimated for all study subjects and mean plasma lipid levels calculated for first, second and third trimesters of pregnancy. RESULTS: There was an increase in the mean concentration of plasma TCHOL, HDL-CHOL, and TG and a decrease in LDL-CHOL in the pregnant subjects as compared to the non-pregnant control subjects. Mean TCHOL, HDL-CHOL, LDL-CHOL and Triglycerides tended to increase with increasing gestational age. CONCLUSION: The results show that pregnancy in black Nigerian women is associated with hyperlipidaemia. The implications of this finding are discussed.

Adult↗
PubMed1998

[The morphometric study of endometrial spiral arterioles before and after insertion of gamma CuI and TCu 220C intrauterine devices].

OBJECTIVE: To investigate the morphologic changes of endometrial spiral arterioles and its relationship with bleeding pattern after insertion of gamma-shape copper indomethacin-medicated (gamma CuI) and T-shape copper (TCu 220C) intrauterine devices (IUD). METHODS: Endometrium specimens of late secretory phase were obtained from fertile age women: 10 from preinsertion, 10 obtained after insertion of TCu 220C IUD, and 9 obtained after insertion of gamma CuI IUD. Samples were sectioned serially and morphometric analysis of endometrial spiral arterioles was performed under light microscope. RESULTS: The average cross section area (Area), maximum diameter (Dmax) and minimum diameter (Dmin) of spiral arterioles in both spongeous and dense layers of endometrium increased significantly after insertion of TCu 220C IUD. After insertion of gamma CuI IUD, the Area and Dmax increased in dense layer only, though less obviously than that occurred in TCu 220C group. However, the Dmin increased more obviously in both spongeous and dense layers than after insertion of TCu 220C IUD, implying that the shape of spiral arterioles was more regular in gamma CuI group. CONCLUSION: gamma CuI IUD has less effects on the morphological changes of endometrial spiral arterioles, and this may relate to its indomethacin-contained which causes less bleeding.

Adult↗