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PubMed1993

Age of marriage and length of the first birth interval in a traditional Indian society: life table and hazards model analysis.

The length of the first birth interval is one of the strongest and most persistent factors affecting fertility in noncontracepting populations, with longer intervals usually associated with lower fertility. Compared to Western society, the average length of the first birth interval is much longer in traditional Indian society. Yet Indian fertility rates are higher because of either ineffective family planning procedures or deliberate nonuse of birth control and because of the high proportion of the population that is married. Here, we examine the effects of various sociodemographic covariates (with an emphasis on the role of age at marriage) on the length of the first birth interval for two states of India: Assam and Uttar Pradesh. Life table and multivariate hazards modeling techniques are applied to the data. Covariates such as age at marriage, present age of mother, female's occupation, family income, and place of residence have strong effects on the variation of the length of the first birth interval. For each subgroup of females (classified according to different levels of the covariates), the median length of the first birth interval for the Assam (Bengali-speaking) sample is shorter than that of the Uttar Pradesh (Hindi-speaking) sample.

Adolescent↗
PubMed2000

Microbial Biomass and Community Structure in a Sequence of Soils with Increasing Fertility and Changing Land Use.

The microbial biomass and community structure of eight Chinese red soils with different fertility and land use history was investigated. Two community based microbiological measurements, namely, community level physiological profiling (CLPP) using Biolog sole C source utilization tests and phospholipid fatty acid (PLFA) profiles, were used to investigate the microbial ecology of these soils and to determine how land use alters microbial community structure. Microbial biomass-C and total PLFAs were closely correlated to organic carbon and total nitrogen, indicating that these soil microbial measures are potentially good indices of soil fertility in these highly weathered soils. Metabolic quotients and C source utilization were not correlated with organic carbon or microbial biomass. Multivariate analysis of sole carbon source utilization patterns and PLFAs demonstrated that land use history and plant cover type had a significant impact on microbial community structure. PLFAs showed these differences more than CLPP methods. Consequently, PLFA analysis was a better method for assessing broad-spectrum community differences and at the same time attempting to correlate changes with soil fertility. Soils from tea orchards were particularly distinctive in their CLPP. A modified CLPP method, using absorbance readings at 405 nm and different culture media at pH values of 4.7 and 7.0, showed that the discrimination obtained can be influenced by the culture conditions. This method was used to show that the distinctive microbial community structure in tea orchard soils was not, however, due to differences in pH alone.

Journal Article↗
PubMed1999

Individual growth patterns in the first trimester: evidence for difference in embryonic and fetal growth rates.

OBJECTIVE: To evaluate individual fetal growth during the first trimester in pregnancies resulting from spontaneous and in vitro fertilization (IVF). METHODS: The growth of 11 fetuses conceived by spontaneous fertilization (known dates of ovulation) in nine patients and 15 fetuses conceived by IVF in 12 patients were evaluated at weekly intervals from 6 weeks, menstrual age, to 14 weeks. Fetal length was determined at each examination. Measures of fetal length included the crown-rump length (CRL), maximum straight line length (MSLL) and maximum axial length (MAL). Comparisons of CRL and MSLL to MAL were carried out. The MSLL was used as the measure of length except when the MAL was available. Linear and quadratic functions were fitted to the complete data sets of individual fetuses in the two groups. Individual data sets from ten fetuses in each group were then divided into early and late growth phases, and linear functions were fitted to each data subset. Start points and pivotal points for each fetus were estimated from the coefficients of these two functions. Growth in these two groups of fetuses was compared, on the basis of slope values. RESULTS: Evaluation of length measures indicated that, before 8 weeks, only MSLL could be measured. After 8 weeks, all three measures could be obtained, with the MAL being the largest. Both the linear and quadratic models performed well with individual data sets (mean R2(+/- SD): linear 98.1 (1.0)%; quadratic 99.4 (0.4)%), with no differences found between spontaneous and IVF groups (maximum possible differences in mean slopes (95% probability): 5-8%). Similar findings were obtained for the early and late growth phase data subsets. Slope values in the early and late growth phases showed low variability (CV: early 13.5%; late 11.6%), but were significantly different (early 0.72 (+/- 0.10 SD) cm/week; late 1.21 (+/- 0.14 SD) cm/week). The mean start point was 5.9 (+/- 0.3 SD) weeks' menstrual age, while the mean pivotal point was 9.2 (+/- 0.7 SD) weeks, menstrual age. CONCLUSIONS: First-trimester growth studies in individual fetuses indicate that there is a change in length growth rate between 9 and 10 weeks, menstrual age. This is consistent with a shift in development from organogenesis to growth. These results can be used for more accurate assessment of first-trimester growth and may aid in the detection of fetal problems that manifest themselves as growth abnormalities.

Anthropometry↗
PubMed2005

[Application of phenological pattern recognition in ecological dynamic forecasting].

This paper described the principles, methods, and procedures of ecological dynamic forecasting by the automation techniques of pattern recognition and mathematical logic judgment on the basis of phenological data and model output maps from T42L9 numerical weather prediction model. This new forecasting method proposed on the basis of modern meteorology and automation techniques enables the classic phenology to apply to a new field ecological forecasting. It enables phenological forecasting to develop from single-station forecasting stage to regional forecasting stage, which is greatly corresponded to the development stage from single station forecasting stage to synoptic stage in weather forecasting, and enables agro-meteorological forecasting to develop from qualitative and statistical forecasting stage to ecological dynamic forecasting stage. With this new qualitative forecasting method, both the predicted objective and predictors are of considerable bio-physical interests. The ecological dynamic forecasting method could be applied to crop sowing, crop growth, irrigation and fertilization, and diseases and pests

Computer Simulation↗
PubMed2005

[Predictive value of endometrial ultrasonography and age for the outcome of in vitro fertilization-embryo transfer].

OBJECTIVE: To assess the predictive value of endometrial ultrasonography and age for the outcome of in vitro fertilization-embryo transfer (IVF-ET). METHODS: A total of 305 women with tubal occlusion were studied. Superovulation was induced and transvaginal ultrasonography was employed for monitoring the endometrial thickness and endometrial patterns on the day of human chorionic gonadotrophin (hCG) administration. Pregnancy was diagnosed by ultrasonography of the intrauterine gestational sac. RESULTS: No difference was noted in the endometrial thickness or endometrial patterns between pregnant and nonpregnant groups, but the least endometrial thickness essential for pregnancy was 7 mm. The pregnant rate of women aged 20-34 years was higher than that of women aged 35 years or above. CONCLUSIONS: Neither endometrial thickness nor endometrial patterns detected by transvaginal ultrasonography on the day of hCG administration allows a reliable prediction of pregnancy. The least endometrial thickness essential for pregnancy is 7 mm and the pregnant rate of women aged 20-34 years was higher than those aged 35 years and above.

Adult↗
PubMed1982

A clinical trial of norethisterone oenanthate (Norigest) injected every two months.

A clinical trial was carried out in which Norigest (200 mg norethisterone oenanthate) was administered by intramuscular injection every 56 days into 383 women studied for 5,521 woman-months of use. No pregnancies occurred. Continuation rates at the end of one, two and three years were 76.6%, 63.7% and 33.8%. Only minor side-effects were recorded. After one year of use, 20.1% women had gained more than 2 kg in weight and 14.8% had lost more than 2 kg. There was marked disruption of the menstrual pattern and irregular bleeding was the major cause of discontinuation. In 38% of the injection intervals analysed, women were amenorrhoeic. Norigest proved an effective and acceptable method of fertility control.

Amenorrhea↗
PubMed2005

From structure to function: methods and applications.

The rapid increase in experimental data along with recent progress in computational methods has brought modern biology a step closer toward solving one of the most challenging problems: prediction of protein function. Comprehension of protein function at its most basic level requires understanding of molecular interactions. Currently, it is becoming universally accepted that the scale of the accumulated data for analysis and for prediction necessitate highly efficient computational tools with appropriate application capabilities. The review presents the up-to-date advances in computational methods for structural pattern discovery and for prediction of molecular associations. We focus on their applications toward a range of biological problems and highlight the advantages of the combination of these methods and their integration with biological experiments. We provide examples, synergistically merging structural modeling, rigid and flexible structural alignment and detection of conserved structural patterns and docking (rigid and flexible with hinge-bending movements). We hope the review will lead to a broader utilization of computational methods, and their cross-fertilization with experiment.

Algorithms↗
PubMed1996

[DNA analysis of a case of so-called blood group chimerism].

A 46-year-old woman who has three children, whose red blood cells exhibit a dual population of groups A and B, was investigated. Her lymphocytes had an XX/XY karyotype and Y chromosome markers were detected from buccal cells and hair root cells in DNA analysis. Three bands were detected in D1S80 VNTR locus (MCT118), two bands from father and one from mother. Her ABO genotype should be genetically AO, however, the PCR-RFLP method revealed a pattern of BO genotype. From these findings, it is concluded that she is a so-called dispermic chimera which is the result of the fertilization by two sperms and that DNA analysis is useful for distinguishing between twin and dispermic chimerism.

ABO Blood-Group System↗
PubMed1998

[Diagnosis of maternal and infant health in Palestine].

OBJECTIVE: To describe the health situation of the target population (women between 15 and 45 and children from 0 to 3), living in the towns on the West Bank in which the 12 dispensaries of the Palestine NGO Health Services Council were located, in order to plan a programme of support activities for that NGO. DESIGN: Crossover survey. Descriptive analysis of the data. SETTING: 12 towns in the 5 districts of the West Bank (Palestine) between May and July 1994. PARTICIPANTS: Women of a fertile age (15 to 45) and children between 0 and 3 living in the towns where the 12 dispensaries of the NGO Health Services Council were located. MEASUREMENTS AND MAIN RESULTS: Social, demographic and health variables of the population group involved, the availability of primary care services and the pattern of health service use were studied. Worthy of mention were the average fertility of fertile women of 4.55 deliveries (CI 95%, 4.30-4.80), the use of family planning methods by 61% of the women surveyed, the low indices of mother and infant malnutrition, and the frequency of episodes of acute respiratory infections and diarrhoea in the under-3s. The availability of health services in these communities is wide. The non-governmental and private Palestinian services were preferred for antenatal control, whereas the Israeli government services were preferred for deliveries, as these services had more resources. CONCLUSIONS: The findings were typical of an intermediately developed society, similar to neighbouring countries. The multiplicity of health services available and their lack of coordination could make the application of a unitary health policy in the area difficult.

Adolescent↗
PubMedDate not supplied

Survival probability of human conceptions from fertilization to term.

Preterm death of the human conceptus is common. A consistent biphasic pattern in the rate of loss from biochemical pregnancy detection to term suggests that most wastage occurs prior to clinical recognition. After simple adjustments for varying methods, existing data show that at least 73% of natural single conceptions have no real chance of surviving 6 weeks of gestation. Of the remainder, about 90% will survive to term. IVF conceptions do nearly as well as natural pregnancies after clinical recognition, but poorly before, despite selecting apparently normal embryos for transfer. Reasons may lie in the uterus more than the embryo itself. Multiple pregnancies may constitute more than 12% of all natural conceptions, of which number about 2% survive to term as twins and about 12% result in single births. In all of these situations, simple equations for exponential decay in a mixture of two populations can accurately describe the distribution of those deaths in time.

Abortion, Spontaneous↗
PubMed2000

A mouse model for breast cancer induced by amplification and overexpression of the neu promoter and transgene.

BACKGROUND: ErbB-2 is a critical oncogenic marker in human breast cancer. Its appearance correlates with poor prognosis and it is, therefore, an important target for physiologic investigation and therapeutic intervention. With this in mind, we have created and characterized two mouse breast cancer models that express rat wild type neu, the homologue of ErbB-2, and rat mutant neu under the control of the normal mouse neu promoter. These models in which the copy number of the neu gene is moderately amplified should more closely parallel the expression pattern of ErbB-2 seen in some cases of human breast cancer. MATERIALS AND METHODS: Transgenic mouse models were constructed by injecting one of the two pronuclei of a fertilized FVB/n egg and implanting it into a pseudopregnant Swiss /Webster mouse. Tissue expression was analyzed through the use of reverse transcription polymerase chain reaction and mammary histopathology examined by fixing, staining and mounting of the entire gland. RESULTS: In the former wild type model, we show that low level, long term expression of neu leads to abnormal lobuloalveolar development in virginal glands and incomplete regression in multiparous glands. Malignant foci form following multiple rounds of pregnancy and regression. In the latter model, a similarly directed transgene carrying the constitutively activated, mutant form of the rat neu gene, a stronger but similar phenotype is displayed. CONCLUSION: Evidently minor perturbations in amplified neu expression are sufficient to alter mammary development and induce malignant transformation.

Animals↗
PubMed1972

Microtubular patterns in spermatozoa of coccid insects in relation to bending.

Flagella-like motion occurs in filamentous spermatozoa of coccid insects, which have diameters (0.16-0.65 micro) and lengths (150-300 micro) similar to those of long flagella, but have no doublets or 9 + 2-like arrangements of microtubules. Light and electron microscope investigations of spermatozoa from 10 species reveal many bizarre patterns of microtubules and suggest some basic similarities to flagella. Detailed analyses of spermatozoa which are naturally bent in definable planes during their elongation in the male and their storage in the female provide evidence that a constant topographical relationship is maintained between their unorthodox patterns of microtubules, as viewed in transections, and the direction of bending. The configuration common to most coccid spermatozoa consists of an acentrically positioned crescent of microtubules surrounded by one to several concentric rings. A line drawn to connect the two ends of the crescent appears to remain perpendicular to the plane of bending, and it defines a plane in which bisection of the spermatozoon produces halves with unequal numbers of microtubules. Bisection of the 9 + 2 motile apparatus in a plane perpendicular to that of bending also appears to produce halves with unequal numbers of microtubules. Therefore, the indispensable elements for flagellar and flagella-like motion may be microtubules arranged in "asymmetric" patterns.

Animals↗
PubMed1997

Patterns of progression and nonprogression through in vitro fertilization treatment.

PURPOSE: Increasing numbers of couples are consulting for infertility and, after some years of investigation and treatment, will become enrolled in in vitro fertilization (IVF) programs. The media have focused on successful outcomes or difficulties in accessing services because of health authority funding guidelines. Couples are often assumed to be highly motivated because of their long prior involvement in treatment. However, little is known about uptake of and continuation through IVF treatment programs. METHODS: One hundred forty-four couples were followed through the process of IVF in a service that allows three cycles of treatment, with a minimum gap of 3 months between treatment cycles. Patterns of engagement in and delay and withdrawal from treatment were examined. RESULTS: One in five couples withdrew from the program before completion of the available number of treatment cycles. A further one in three significantly delayed their involvement in treatment cycles. Mean deviations of the time between attempts increased as the numbers of treatment cycles progressed. A proportion of couples did not complete a single treatment cycle. CONCLUSIONS: The dramatic proportions of patients withdrawing from or very significantly delaying subsequent involvement are indicative of the often unacknowledged difficulties associated with IVF treatment. Implications for care are discussed.

Behavior↗
PubMed2001

Management of prepubertal varicoceles-results of a questionnaire study among pediatric urologists and urologists with infertility training.

OBJECTIVES: Varicoceles are a common condition affecting male fertility seen by urologists. However, prepubertal varicoceles are much less common and their management is controversial. We designed a questionnaire to assess the practice patterns among urologists (pediatric urologists/urologists with infertility training) with regard to prepubertal varicocele management. METHODS: A 15-point questionnaire pertaining to management issues of prepubertal varicoceles was sent to 150 pediatric urologists and 150 urologists with infertility training. Two clinical scenarios referring to treatment algorithms of prepubertal varicoceles were included. RESULTS: Of the 300 questionnaires mailed, 174 urologists (58%) responded. Seventy-five of the respondents were urologists with an interest in infertility, and 99 were pediatric urologists. Of the 174 respondents, 86.2% treated prepubertal varicoceles and 13.8% referred patients to interventional radiologists for embolization. The ratio of varicocelectomy to expectant management was about equal between urologists with infertility training and pediatric urologists (46% versus 54%). A difference in testicular size was the most common indication for varicocelectomy (80.5%), followed by pain (51.1%) and potential fertility problems (24.7%). About one third of all urologists would perform varicocelectomy on patients of any age and seven (4%) would not operate before puberty. In 136 responses (78.2%), follow-up information was not available. Among the 35 respondents with follow-up information (21.8%), 21 reported infertility occurring after varicocelectomy and 16 after expectant management. If varicocelectomy was performed, most urologists (47.2%) used magnification loupes, 29.3% used microscopes, and 29% used no magnification. The preferred approach was inguinal (Ivanissevich) in 35.6% followed by subinguinal in 30%; 21% performed retroperitoneal varicocelectomy (Palomo) and 9.8% used a laparoscopic approach. Of the 300 complications reported, postoperative hydroceles were the most common (40.4%), followed by recurrence (20.8%) and hematomas (17.4%). CONCLUSIONS: The management of prepubertal varicoceles is controversial among different urologic subspecialties (pediatric urology/infertility). Differences include indications, timing, and techniques used for varicocelectomy. Accurate follow-up information for children with prepubertal varicoceles is rare. A prospective randomized study comparing varicocelectomy versus expectant management of prepubertal varicoceles is needed to assess the outcomes and define uniform treatment criteria.

Adolescent↗
PubMed1994

Micromachined electroporation system for transgenic fish.

Luciferase gene was introduced into fertilized eggs of medaka by a localized electric field between thin film electrodes formed on a glass plate. Miniaturization of the electrodes enabled us to apply a localized electric field to the animal pole of the fertilized egg. Biochemical luminescence and an electrophoresis pattern showed expression and integration of the gene, respectively. The presented system had a higher ratio of gene introduction than the conventional electroporation method.

Animals↗
PubMed1999

Preliminary evaluation of porcine zona pellucida (PZP) immunocontraception for behavioral effects in feral horses (Equus caballus).

Successful management of captive populations of wild animals requires effective control of reproduction. Contraception is one tool for controlling reproduction of animals in zoos; however, the options available to the animal manager are limited. Contraceptives vary in efficacy, reversibility, and side effects, and thus may not be suitable for widespread use. One consideration when selecting a contraceptive is its potential for side effects on behavior, especially given the fact that reproduction plays such a prominent role in the biology of any species. To date, there have been few evaluations of contraceptives for behavioral effects, and those that have been conducted have focused on hormone-based contraceptives. This study sought to evaluate a novel method of population control, immunocontraception, for behavioral effects in a population of feral horses. Porcine zona pellucida (PZP) immunocontraception prevents fertilization of ova and does not alter normal hormone secretion patterns. It therefore should leave the animal behaviorally intact in terms of reproductive behavior. The study examined the behavior of 43 sexually mature mares on Assateague Island during the 1997 breeding season and, with help from Earthwatch volunteers, collected observations over a 3-month period. The study found no significant differences between treated and untreated mares in general activity budget, aggression given or received, and spatial relationships relative to the stallion. These preliminary findings indicate that PZP contraception seems to have no acute behavioral effects on the behavior of individuals. The study findings also suggest that PZP could be a desirable and effective management tool for captive species in which social behavior plays an integral role in group dynamics. Analyses of group level effects and population level effects are continuing.

Journal Article↗
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↗