[An attempt to explain fertility differentials in Upper Volta and in Ghana].
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A questionnaire was offered to 181 sixteen-year-old boys (n = 88) and girls (n = 93) in different schools in the city of Uppsala. The questionnaire was introduced to the students by a nurse midwife during a regular lesson and included over 100 questions dealing partly with sexual education, attitudes towards sex and own experience of sex and contraception. Of the girls, 47% and of the boys, 31% answered that they had had intercourse. Twenty-eight per cent of the girls and 21.5% of the boys had had their first intercourse before the age of 15. Contraception was used at the first intercourse by 59% of the girls and by 70% of the boys. At the very first intercourse, the condom was the most commonly used contraceptive method. Increasing sexual experience changed the contraceptive pattern and at their last intercourse 48% of the girls were on the pill and 33% of the boys said that their girl friend was on the pill.
Canada's first national fertility survey, carried out by telephone in 1984, found that 68 percent of all women aged 18-49-73 percent of currently married women, 69 percent of the previously married women and 57 percent of single women--are practicing contraception. Overall, the most widely used method of birth control in Canada is sterilization (male and female), which is relied on by almost 60 percent of all married users and 66 percent of previously married users. Among single women, the preferred method is the pill, chosen by seven out of 10 of such users. Among all women, the major determinant of method choice is age: The pill is overwhelmingly chosen by women under 25, and sterilization, by those 30 and over. While the IUD and the condom are used by roughly 10-14 percent of women in their 20s who practice contraception, these methods decline in importance with increasing age. Highly educated women are less likely than those with little education to elect sterilization, and more likely to rely on barrier methods. Differences in contraceptive prevalence and patterns of use between Catholics and Protestants have all but disappeared in Canada, but church attendance and country of birth appear to exert a modest influence on method choice. As might be anticipated, women whose family size is complete have considerably higher levels of contraceptive use than those who expect to have more children. The survey reveals no difference in contraceptive use between Quebec women and those in the rest of Canada, thus confirming both the accuracy of earlier Quebec studies showing extremely high levels of sterilization and the applicability of these findings to all other Canadian women.(ABSTRACT TRUNCATED AT 250 WORDS)
Several putative Oct-4 downstream genes from mouse embryonic stem (ES) cells have been identified using the suppression-subtractive hybridization method. In this study, one of the novel genes encoding an ES cell and germ cell specific protein (ESGP) was cloned by rapid amplification of cDNA ends. ESGP contains 801 bp encoding an 84 amino acid small protein and has no significant homology to any known genes. There is a signal peptide at the N-terminal of ESGP protein as predicted by SeqWeb (GCG) (SeqWeb version 2.0.2, http://gcg.biosino.org:8080/). The result of immunofluorescence assay suggested that ESGP might encode a secretory protein. The expression pattern of ESGP is consistent with the expression of Oct-4 during embryonic development. ESGP protein was detected in fertilized oocyte, from 3.5 day postcoital (dpc) blastocyst to 17.5 dpc embryo, and was only detected in testis and ovary tissues in adult. In vitro, ESGP was only expressed in pluripotent cell lines, such as embryonic stem cells, embryonic caoma cells and embryonic germ cells, but not in their differentiated progenies. Despite its specific expression, forced expression of ESGP is not indispensable for the effect of Oct-4 on ES cell self-renewal, and does not affect the differentiation to three germ layers.
Studies of infant and child mortality have evolved to distinguish between two sets of explanatory variables-factors related to reproductive or maternal characteristics and socioeconomic factors, generally described as characteristics of the family or household. Almost all multivariate analyses include variables from each of these two sets, but there has been little consideration of the relationship between them. We examine how these two sets of variables jointly affect mortality. We test first for confounded effects by examining socioeconomic effects while excluding and then including reproductive variables in nested multivariate models. Next, we look for age-dependent effects among the explanatory variables and find that reproductive and socioeconomic factors affect mortality at differing ages of children. Finally, we examine interactive effects of the two sets of variables. We conclude that the higher mortality observed among the low status groups is not a result of greater concentration of poor reproductive patterns in those groups. Instead, higher status groups probably have more resources available for combating the negative effects of the same high-risk reproductive patterns.
Bone may provide an extremely fertile microenvironment for angiogenesis. Experimental investigations indicate angiogenesis as a major regulator of bone metastasis development. Vascularization and angiogenic potential is known for most of the primary tumor types, but no studies investigated angiogenesis in bone metastases of human cancers. We have evaluated microvessel density of bone metastases of various cancer types (all adenocarcinomas) and compared to their primary tumors in paraffin samples of 39 patients. Microvessel density was determined by using the hot spot method and the blood vessel marker, CD34. The most vascularized adenocarcinoma was found to be renal cell cancer followed by lung adenocarcinoma, while breast cancer was heterogenous in this respect. Two patterns of modulation of the angiogenic phenotype in the bone metastases emerged in this study, which seemed to be cancer type specific: decreased angiogenic potential characterizing 45% of renal cell cancers and breast cancers of high vascularity in their primary, and increased angiogenic potential characterizing 40% of lung adenocarcinomas and breast cancers of low vascularity in their primary lesion. Our data demonstrate that i., the vascularization of bone metastases is frequently altered compared to the primary tumors, ii., patterns are different in the case of various cancer types. The tumor-type specific alterations of the angiogenic phenotype of cancers, metastatic to the bone, can have a clinical significance when angiosuppressive therapies are considered.
PURPOSE: The presence of a clear half-moon-like zone of cytoplasm in oocytes is called "halo effect." The prognostic value of this effect is not yet determined. Aligned nucleoli in pronuclei (PN) represent a further polarization phenomenon and a marker for implantation potential. Aim of the prospective study was to evaluate the influence of the halo effect on IVF outcome and to compare the results with observed polarization in PN. METHODS: A total of 374 cycles with embryonic transfer were analyzed regarding halo effect and pattern of nucleoli. The oocytes were single-cultured to observe the following embryo quality of each PN stage. RESULTS: Cycles with halo-positive oocytes showed a significant higher pregnancy rate (44.0% vs. 31.1%; p < 0.05). Furthermore, higher pregnancy rates in cycles with polarized nucleoli were observed. Polarized PN resulted in a significant lower fragmentation and higher cleavage rate of embryos. The fragmentation rate was significantly lower in halo+ oocytes, but the cleavage rate was not influenced. CONCLUSIONS: The results indicate that the presence of a polarized zone of human fertilized oocytes can be a useful indicator for good oocyte quality. Since the origin of ooplasmic polarization seems to be a different process compared with the alignment of nucleoli, the observation will give additional predictive information about the implantation potential.
INTRODUCTION: The molecular mechanism of human embryo implantation is poorly understood. The role of MUC4 mucin, present in endometrial epithelium, has never been explored, and results obtained in animal studies strongly suggest a role in implantation. We investigated the role of MUC4 in human embryo implantation. METHODS AND RESULTS: We analysed the MUC4 variable number of tandem repeat (VNTR) polymorphism in three populations by Southern blot analysis: spontaneously fertile patients (C), infertile patients with repeated unexplained implantation failures after IVF (IF) and patients with a child after IVF (IVF-C). We found no differences in the size or allelic distribution of MUC4 VNTR between these three populations. We also examined, in IVF-C and IF groups, the endometrial expression of MUC4 mRNA as well as the expression of the MUC4 glycoprotein together with estrogen receptor (ER) and progesterone receptor (PR). No expression differences could be detected. However, we noticed a pattern of expression for MUC4 protein, which is limited to patches of cells in the luminal and glandular epithelium. CONCLUSIONS: We conclude that the different-sized MUC4 alleles do not interfere with implantation. The absence of coexpression of MUC4 and the steroid receptors suggests that MUC4 expression is not directly regulated by steroids.
In general, it can be concluded that the initiative on the determinants and consequences of induced abortion has shown some important patterns. For example, induced abortion is not restricted to adolescents but occurs also within marriage to limit family size. Induced abortion is prevalent both where family planning services are available and contraceptive prevalence is high as well as where family planning is not common, but for different reasons. In the former, motivation to limit family size is high and women would use any option if contraception fails or an unwanted pregnancy occurs. In the latter case, induced abortion forms part of a mix of incipient fertility regulation alternatives, most of which are traditional and of little effectiveness but including some use or improper use of modern methods. Few abortion seekers, and among them even fewer adolescents, were using a modern contraceptive at the time the pregnancy started. High use of traditional methods in some countries leads to abortion as women/couples fail to follow proper instructions with regards to the safe period. Unsafe clandestine abortions are more likely to be sought by poorer women and by adolescents. The findings of this research are increasingly being used to question the legal status of abortion in countries where the law is restrictive, or to strengthen family planning efforts in order to reduce abortion incidence.
The author studies child mortality in Nepal in this section of a large comparative project involving 15 developing countries. "Employing a method suggested by Trussell and Preston (1982) a child mortality index is computed for every woman by relating actual number of child deaths to the expected number of child deaths implied by marital duration, fertility, and the national mortality level. Based on the Nepal Fertility Survey of 1976 bi-, tri-, and multivariate analysis showed significant child mortality differentials according to mothers' and fathers' education, religion, and ecological region. The population of Nepal is still extremely homogeneous in that 96% of all ever-married women aged 15-49 can neither read or write, 95% live in rural areas, and 90% are Hindus. For women deviating from this pattern child mortality is in most cases substantially lower." (SUMMARY IN ENG)
Cytoplasmic male sterility (cms) in rye (Secale cereale L.), especially cytoplasma PAMPA, is used commercially in hybrid breeding programmes. The development of molecular markers that are tightly linked to the numerous genes coding for pollen fertility is expected to have great impact in the field. Morphological and cytological analyses of plants from a three-way cross C394: [(S67P/94 x S38/94) x CHD296] indicated the presence of at least several genes acting at different stages of pollen grain development, and proved the concurrence of both approaches in plant classification. The AFLP technique combined with the Bulk Segregant Analysis (BSA) were applied to identify DNA fragments linked to the genes of interest. All the 256 possible primer pair combinations based on the MseI and EcoRI restriction sites generated distinct band patterns allowing the identification of 31143 DNA fragments, visualised using the isotopic method. On average, any given primer combination generated 122 fragments. Among 1111 and 431 potential genetic markers respectively identified in the restorer form and the maternal lines, 775 and 295 were present in the F2 population. These numbers were then reduced to 109 and 51. The identified DNA fragments were tested on a limited segregating population, C394-F2, in order to eliminate false signals and to select markers for a future marker-assisted selection programme. Twenty-five markers were selected. Four of these markers were not identified via the BSA approach, indicating that if a highly polymorphic component is used for a cross, or a polygenic trait is studied, then the use of a limited population may be required.
PURPOSE: Men with azoospermia, markedly elevated serum follicle-stimulating hormone levels and testicular atrophy were previously considered irreversibly infertile. Thus, testicular biopsy in this patient population was considered unnecessary. However, presently men with even the most severe infertility disorders are potentially able to initiate a pregnancy with intracytoplasmic sperm injection provided sperm can be recovered in even relatively few numbers directly from the testicular tissue. For these reasons we sought to reevaluate the findings from testicular biopsies in these men in the era of advanced micromanipulation techniques. MATERIALS AND METHODS: Chart review identified men with azoospermia, confirmed on a pelleted specimen, and a serum follicle-stimulating hormone level of 3 or more times normal. Mature sperm in the touch preparation cytology and testis biopsy specimen were confirmed. RESULTS: A total of 57 men, most with testicular atrophy, underwent a testicular biopsy and in 17 (30%) mature sperm were identified. The most common diagnosis in these men was severe hypospermatogenesis. Men without sperm most commonly had a pure Sertoli-cell-only pattern. CONCLUSIONS: Men with azoospermia and testicular atrophy with significantly elevated follicle-stimulating hormone levels should undergo testicular biopsy if in vitro fertilization with intracytoplasmic sperm injection is an acceptable approach for the couple.
BACKGROUND: Deliveries among women who had an in vitro fertilization (IVF) are characterized by increased risks for both the mother and the infant/child. Part of these effects may be due to maternal characteristics. METHODS: Using reports from all clinics performing IVF in Sweden, 12 186 women who gave birth after such procedures were identified (13 261 deliveries, 16 280 infants born). Various social and medical characteristics of the women were studied and compared with all women giving birth. Information was retrieved by interviews in early pregnancy or by linkage with various registers. RESULTS: Women who had IVF were older than other women who gave birth and were older after standard IVF than after intracytoplasmatic sperm injection (ICSI). They were more often of first parity and smoked less than other delivered women. There were more women with high body mass index: they worked outside home less often and were more often of Swedish nationality. Women who had standard IVF had more previous miscarriages than expected, but this was not true for women who had ICSI. Their pattern of drug usage differed from that of other women who had given birth. CONCLUSIONS: Women who underwent IVF and gave birth showed marked deviations from other women who gave birth. Some of these characteristics may help to explain the increased risks associated with these procedures. Women who had ICSI were less deviating than women who had standard IVF.
Explore the source record for details and available documents.
Effect of chromosomal rearrangements on the expression of mutations was studied in Drosophila melanogaster regulatory genes. These were facultative dominant lethals and recessive lethals on the X chromosome obtained by the classical Muller-5 method. Chromosomal rearrangements drastically changed the expression of regulatory gene mutations. Rearrangements either caused the lethal effect of mutations or suppressed the already present lethality. The action of rearrangements exhibited the maternal or paternal effect. Irrespective of the presence in the genome of mutations at regulatory genes, a rearrangement acted as a factor decreasing fertility of the organism. The rearrangement effect is identical to the expression of regulatory genes per se. It is concluded that the chromosomal rearrangement affects the examined regulatory genes indirectly through a change in the operation of regulatory genes located within the rearrangement. Thus, rearrangements gain great importance for the definition of the pattern of genome functional activity. Widespread distribution of rearrangements in individual genotypes and their effectivity in the process of speciation are thus explained.
Studies of capillary morphogenesis and angiogenesis in vitro have suggested a role for E-selectin (CD62E) in the process of differentiation into tube-like structures. Recent studies by our group and others have demonstrated that mice lacking E-selectin because of germline inactivation of the E-selectin gene by gene targeting are viable and fertile, without apparent deficiencies in vascular development. Murine lung endothelial cells from wild-type and E-selectin-deficient animals were isolated using an activation-dependent sterile sorting method, and differentiation into tube-like structures on sparse fibronectin, Matrigel, and collagen gels was compared. Both types of murine lung endothelial cells spontaneously organized to form multicellular tubes and extensive anastomotic networks. There were no major differences in either the time course of development or the general appearance of the multicellular cords or tube-like structures formed by murine lung endothelial cells from wild-type or E-selectin-deficient mice, although different patterns were observed on different extracellular matrices. These studies, thus, demonstrate that E-selectin is not required for morphogenesis of 3-dimensional vascular structures in vitro.
Extended durations of postpartum non-susceptibility (PPNS) comprising lactational amenorrhoea and associated taboos on sex have been a central component of traditional reproductive regimes in sub-Saharan Africa. In situations of rising contraceptive prevalence this paper draws on data from the Demographic Health Surveys to consider the neglected interface between ancient and modern methods of regulation. The analysis reports striking contrasts between countries. At one extreme a woman's natural susceptibility status appears to have little bearing on the decision to use contraception in Zimbabwe, with widespread 'double-protection'. By contrast, contraceptive use in Kenya and Ghana builds directly onto underlying patterns of PPNS. Possible explanations for the differences and the implications for theory and policy are discussed.