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Results for “Fertility Pattern Method”

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PubMed2000

in vitro development of porcine enucleated oocytes reconstructed by the transfer of porcine fetal fibroblasts and cumulus cells.

In the pig little information is available on cytoplasmic events during the reprogramming of oocytes reconstructed with somatic nuclei. The present study was conducted to determine the developmental potential of porcine cumulus cells (CC) and fetal fibroblasts (FF) after they were transferred into enucleated oocytes. Non-quiescent FF were fused to the enucleated oocytes using electrical pulse, whereas CC were directly injected into the oocytes. Transferred nuclei from both CC and FF underwent premature chromosome condensation (PCC), nuclear swelling and pronucleus formation. The remodeled oocytes developed to the mitotic and 2-cell stage at 18 to 24 h after nuclear transfer. The pattern of nuclear remodeling was similar regardless of the sources of karyoplasts or nuclear transfer methods. However, using FF, 24% of nuclear transferred embryos developed to the morula or blastocyst stage, whereas only 8% of those using CC developed to the morula or blastocyst stage. These results suggest that porcine oocyte cytoplasm can successfully reprogram somatic cell nuclei and support the development of nuclear transferred embryos to the blastocyst stage.

Animals↗

PubMed1984

The study of GnRH control of reproductive function.

The activity of the hypothalamic-pituitary-gonadal (HPG) axis is controlled by gonadotropin-releasing hormone (GnRH). GnRH, gonadotropins, and gonadal sex steroids are secreted in a pulsatile fashion. As the peripheral plasma concentrations of GnRH are too low for the existing assay systems, the pattern of pulsatile release of gonadotropins is often utilized for the indirect estimation of hypothalamic GnRH activity. In addition, the long-term pulsatile administration of exogenous GnRH in selected states of GnRH deficiency provides important information on the regulation of the HPG axis. Because of the limits of each approach, both investigational tools should be used complementary for the study of GnRH role in the control of pituitary and gonadal function. This article reviews recent information on GnRH physiology acquired with the use of these methods.

Animals↗

PubMed1989

Follicle size by ultrasound versus cervical mucus quality: normal and abnormal patterns in spontaneous cycles.

Ultrasound (US) has been demonstrated to be the method of choice for diagnosing luteinized unruptured follicle syndrome and to be a valuable adjuvant in the assessment of luteal phase defect. In this prospective study, the use of US with postcoital testing (PCT) is evaluated. Fifty control infertility patients were examined with serial US for follicle dynamics in conjunction with PCT. Standard curves for follicle dynamics versus cervical mucus quality (Insler score) were calculated. Eighteen patients referred for abnormal mucus underwent similar evaluation. Their follicle dynamics versus mucus quality were compared with those of the controls. The findings were: (1) there is a predictable relationship between follicle size and mucus quality, (2) the majority of patients with abnormal mucus have normal follicular dynamics, and (3) a minority of patients with abnormal mucus have either a narrow mucus window or abnormal follicular dynamics. In addition, US was found to be cost-effective in the overall fertility evaluation.

Cervix Mucus↗

PubMed1999

Microconidia of Neurospora crassa.

Neurospora crassa produces two types of vegetative spores-relatively small numbers of uninucleate microconidia and very large numbers of multinucleate macroconidia (blastoconidia and arthroconidia). The microconidia can function either as spermatia (male gametes) or as asexual reproductive structures or both. In nature they probably function exclusively in fertilization of protoperithecia. The environmental conditions favoring their formation and the pattern of their development are quite distinct from those of macroconidia. Mutants of N. crassa have been isolated in which macroconidiation is selectively blocked without affecting microconidiation, showing that these two types of conidial differentiation involve distinct developmental pathways. Unlike microconidia of some related ascomycetes, those of Neurospora are capable of germination, providing viable uninucleate haploid cells which are desired in several types of investigations. A technique of selectively removing macroconidia from culture initiated on cellophane overlying agar medium allows pure microconidia to be obtained even from the wild-type strains of Neurospora. The conditional microcyclic strain, mcm, allows either macroconidia or microconidia to be obtained at will, depending on the conditions of culture. The new methods of obtaining pure microconidia from normal laboratory strains will make it quick and easy to purify heterokaryotic transformants following introduction of DNA into multinucleate protoplasts. Moreover, these methods allow the detection of genetic variability that remains hidden within an individual fungus and the estimation of the frequency of nuclear types in laboratory-constructed heterokaryons. The discovery, function, and development of microconidia are described and their research applications are discussed in this review.

Culture Media↗

PubMed2006

Endocrine disrupting chemicals (bisphenol A, 4-nonylphenol, 4-tert-octylphenol) modulate expression of two distinct cytochrome P450 aromatase genes differently in gender types of the hermaphroditic fish Rivulus marmoratus.

To understand the effect of endocrine-disrupting chemicals (EDCs) on cytochrome P450 aromatase (rm-cyp19) gene expression between gender types in the hermaphroditic fish Rivulus marmoratus, we cloned two distinct rm-cyp19 genes using RT-PCR with degenerative primers, obtained full-length cDNAs using 5'- and 3'-RACE-PCR methods, and completely sequenced them. The brain aromatase (rm-cyp19b) cDNA consisted of 2,124 bp including the open reading frame (ORF), which encoded a putative protein of 505 amino acids. The ovarian aromatase (rm-cyp19a) cDNA consisted of 2,075 bp, including the ORF encoding a putative protein of 516 amino acids. Expression patterns of rm-cyp19b and rm-cyp19a mRNAs were investigated in embryos of different developmental stages and in seven different tissues of adult fish. The rm-cyp19b gene in hermaphrodite and secondary male R. marmoratus was predominantly expressed in the brain, while the rm-cyp19a gene was expressed gender-specifically in the gonad. The expression of rm-cyp19b mRNA increased from stage 1 (2 d post fertilization) to stage 4 (12 d post fertilization) in a developmental stage-dependent manner but steeply decreased in the hatching stage. Compared to the rm-cyp19b gene, the abundance of ovarian aromatase rm-cyp19a transcripts was very low, and its expression was first detected at stage 3 and then decreased gradually to the hatching stage. Alteration of rm-cyp19b and rm-cyp19a gene expression was further analyzed in the brain and gonad by real-time RT-PCR 96 h after EDC exposure in hermaphrodites and secondary males. The brain aromatase rm-cyp19b gene was up-regulated in the brain after 4-nonylphenol (4-NP)-exposure, while the ovarian aromatase rm-cyp19a gene was significantly down-regulated in the gonad. In 300 microg/L 4-tert octylphenol (4-tert-OP), or 600 microg/L bisphenol A-exposed brain and gonad, both rm-cyp19b and rm-cyp19a genes were up-regulated. In the case of secondary males, the rm-cyp19b gene was highly expressed in the 4-NP-exposed brain, while expression of the rm-cyp19a gene was not detected in the gonad. These results indicate that the expression of rm-cyp19a and rm-cyp19b genes is differently modulated according to estrogenic compounds and gender type of R. marmoratus.

Animals↗

PubMedDate not supplied

Revision of hypo-osmotic swelling (HOS) test with a proposition of classified grading system: its comparisons with four different types of human sperm separation technique.

In this study, we arbitrarily classified the morphological changes of sperm under hypo-osmotic condition and compared the results with four different sperm separation techniques. The morphology of classification ranged from a good swelling (SG 3 > SG 2 > SG 1), to non-swelling but reactive (SG 0-R), and completely non-swelling (SG 0). Thirty fresh semen from patients were divided into 4 groups and each processed by washing, swim up, 2-layer column and real time micro-separation system. The prevalent patterns of the swollen sperm in sequence after treatment was SG 0 > SG 1 > SG 3 > SG2 > SG 0-R in fresh semen, and the proportion of SG 0 was almost half of the total % HOS test results. However, SG 3 became the most common swollen form with a significant increase in number with any method of sperm preparation after treatment. The real time technique yielded the highest % rate of SG 3 type of swollen spermatozoa and was the richest in concentration (53+/-3.9%, P < 0.05) as compared with that of swim up (26+/-4.6%), 2-layer (20+/-4.4%), sperm washing (23+/-3.9%), and fresh semen (17+/- 2.8%), respectively. By contrast, 2-layer collected more number of SG0-R (5.3+/-1.2%, P < 0.05) pattern of spermatozoa when compared to real time and swim up. A positive correlation (r = 0.81, P < 0.002) was shown between the % total HOS spermatozoa and total motility of fresh semen but not with morphology. Collectively, an abnormally functional sperm may exist in almost half of a total sperm count from men. It would appear that a better potential fertilization capacity may reside in the more swollen sperm from HOS test than the less swollen sperm and that may be more related with the motility rather than the morphology. The HOS classification and grading system appears valuable in further evaluating sperm quality.

Cell Culture Techniques↗

PubMed1995

Timing of sexual intercourse in relation to ovulation. Effects on the probability of conception, survival of the pregnancy, and sex of the baby.

BACKGROUND: The timing of sexual intercourse in relation to ovulation strongly influences the chance of conception, although the actual number of fertile days in a woman's menstrual cycle is uncertain. The timing of intercourse may also be associated with the sex of the baby. METHODS: We recruited 221 healthy women who were planning to become pregnant. At the same time the women stopped using birth-control methods, they began collecting daily urine specimens and keeping daily records of whether they had sexual intercourse. We measured estrogen and progesterone metabolites in urine to estimate the day of ovulation. RESULTS: In a total of 625 menstrual cycles for which the dates of ovulation could be estimated, 192 pregnancies were initiated, as indicated by increases in the urinary concentration of human chorionic gonadotropin around the expected time of implantation. Two thirds (n = 129) ended in live births. Conception occurred only when intercourse took place during a six-day period that ended on the estimated day of ovulation. The probability of conception ranged from 0.10 when intercourse occurred five days before ovulation to 0.33 when it occurred on the day of ovulation itself. There was no evident relation between the age of sperm and the viability of the conceptus, although only 6 percent of the pregnancies could be firmly attributed to sperm that were three or more days old. Cycles producing male and female babies had similar patterns of intercourse in relation to ovulation. CONCLUSIONS: Among healthy women trying to conceive, nearly all pregnancies can be attributed to intercourse during a six-day period ending on the day of ovulation. For practical purposes, the timing of sexual intercourse in relation to ovulation has no influence on the sex of the baby.

Adult↗

PubMed2005

Environmental biogeochemical behaviors of rare earth elements in soil-plant systems.

With the continual increase in the utilization of rare earth elements (REEs) for industrial and agricultural purposes in China, the research into the environmental biogeochemical behavior of REEs has become a pressing issue. The REEs' content in soil and various parts of wheat under different conditions in soil-plant systems were measured by INAA and ICP-MS. The results showed four aspects. (1) The mean value of total REEs in soil of China was 176.8 mg kg(-1). The mean ratio of SigmaLREE/SigmaHREE in soils was 8.0 and cerium accounts for 42% of the total REEs. The content of REEs in wheat seed ranged between 10(-11) and 10(-8) g g(-1), 3-4 orders of magnitude lower than that in soil. (2) The REEs contents in ryegrass, especially in roots, were significantly related to that of soil. The bioavailability of REEs in soil mainly depended on the exchangeable fraction of REEs, which was strongly affected by the physico-chemical properties of the soil. (3) Long-term foliage-dressing with Changle microfertilizer of REEs did not affect the contents and distribution patterns of REEs in soil. At the maturing stage of spring wheat, the REEs content was in the order of root > leaf >stem and crust. Compared with the control, foliage-dressing has a higher accumulation of REEs in root and leaf. However, no significant difference was found in stem and crust between the two treatments. (4) There was no significant accumulation with the soil-dressing method. When comparing controls in both foliage- and soil-dressing methods, no distinct residue of REEs in grains was found.

Fertilizers↗

PubMed2006

Matrilineal fertility inheritance detected in hunter-gatherer populations using the imbalance of gene genealogies.

Fertility inheritance, a phenomenon in which an individual's number of offspring is positively correlated with his or her number of siblings, is a cultural process that can have a strong impact on genetic diversity. Until now, fertility inheritance has been detected primarily using genealogical databases. In this study, we develop a new method to infer fertility inheritance from genetic data in human populations. The method is based on the reconstruction of the gene genealogy of a sample of sequences from a given population and on the computation of the degree of imbalance in this genealogy. We show indeed that this level of imbalance increases with the level of fertility inheritance, and that other phenomena such as hidden population structure are unlikely to generate a signal of imbalance in the genealogy that would be confounded with fertility inheritance. By applying our method to mtDNA samples from 37 human populations, we show that matrilineal fertility inheritance is more frequent in hunter-gatherer populations than in food-producer populations. One possible explanation for this result is that in hunter-gatherer populations, individuals belonging to large kin networks may benefit from stronger social support and may be more likely to have a large number of offspring.

Allelic Imbalance↗

PubMed1995

Bovine herpesvirus 1 in semen of bulls and the risk of transmission: a brief review.

Outbreaks of bovine herpesvirus 1 (BHV1) infections in artificial insemination centres can run a clinical or subclinical course. Clinical signs vary from mild to severe balanoposthitis and may be associated with a decrease in semen quality. After intranasal as well as intrapreputial infection, BHV1 can replicate in the preputial and penile mucosae, although the pattern of virus shedding in semen differs considerably per individual bull. Beyond the primary phase of a genital infection, BHV1 remains latent in sacral ganglia, and consequently a protracted course of intermittent virus excretion may follow. The seminal plasma rather than the sperm cells contains the BHV1. Diluting the semen before inoculating cell cultures appears to be the best method to neutralize its toxic activity and to achieve optimal virus isolation results. Detection of BHV1 in semen by polymerase chain reaction seems to be more sensitive than virus isolation. Not each extended semen straw contains virus when the virus titre in the ejaculate is low. The minimal dose to infect a cow by artificial insemination may be more than 32 infectious virus particles. Such an infection may lead to fertility disturbances, mainly endometritis. The risk of transmitting BHV1 to inseminated cows by using BHV1-seropositive bulls for artificial insemination is substantially reduced if two straws per semen batch are assayed for virus and if each positive batch is destroyed.

Animals↗

PubMed1982

Development of the ability to bind to zonae pellucidae during epididymal maturation: reversible immobilization of mouse-spermatozoa by lanthanum.

Mouse spermatozoa recovered from the caput, corpus, or cauda epididymidis were examined for their ability to bind the vitro to zonae pellucidae. Since spermatozoa from the caput epididymidis do not display progressive motility as compared with more mature spermatozoa, direct comparison of the different sperm populations may not measure zona binding ability validly. To equalize the motile properties of the spermatozoa, a method was developed to immobilize vigorously motile corpus and cauda spermatozoa. Reversible immobilization was achieved by incubation in 25 microM La3+ which resulted in a twitching, nonprogressive type of motility. La3+ incubation did not appear to affect the spermatozoa adversely, since vigorous motility (equivalent to the controls) of corpus and cauda sperm was displayed upon subsequent incubation in standard La3+-free culture medium. Moreover, cauda spermatozoa preincubated for 90 min in La3+ displayed levels of fertilization in vitro equivalent to their control counterparts. Using this La3+-immobilization technique, the zona binding ability of the different sperm population could be assayed. Gamete collision was insured under these conditions by shaking the gamete-containing dishes at 100 cycles/min. Regardless of the extent of sperm motility, a similar zona-binding pattern emerged: cauda sperm bound in high numbers, corpus sperm bound at some intermediate level (an average of 24% of cauda binding level), and caput sperm bound rarely (2% of cauda binding level). Thus it appears that, for mouse spermatozoa, the onset of fertility during epididymal transit parallels the ability to bind to zonae pellucidae. Unlike the interaction between spermatozoa and zonae, La3+ was unable to support sperm binding in to egg plasma membrane, supporting the view that mouse sperm may have different sites for interaction with the zonae pellucida and the egg plasma membrane.

Animals↗

PubMed1996

Estrogen regulates the stage-specific expression of kidney androgen-regulated protein in rat uterus during reproductive cycle and pregnancy.

The female sex steroid, estrogen, acting through its nuclear receptor profoundly influences growth and differentiation programs in the mammalian uterus by regulating the expression of specific cellular genes. The identity and profile of expression of the estrogen-regulated genes at various stages of the reproductive cycle and pregnancy, however, remain largely unknown. Using a differential gene expression screen method, we isolated a gene that is down-regulated in the uterus during pregnancy. This gene encodes the previously identified androgen-regulated protein known as the kidney androgen-regulated protein (KAP) because of its abundant expression in the kidney. Our results showed a high level of KAP messenger RNA (mRNA) in the uteri of nonpregnant rats at all stages of the estrous cycle. We observed that in the pregnant animals, the level of KAP mRNA remained high immediately after fertilization (days 1 and 2), but declined sharply with the progression of pregnancy, falling to almost undetectable levels during midgestation (days 10-15). Interestingly, the level of KAP mRNA started to rise again toward the end (day 19 onward) of pregnancy and was high during parturition. The temporal pattern of expression of KAP in the uterus closely overlapped with the profile of plasma estrogen during pregnancy. Known antagonists of estrogen, such as tamoxifen and ICI 182,780, strongly inhibited uterine KAP gene expression during the estrous cycle and pregnancy, supporting a regulatory role of estrogen in this process. Consistent with this observation, administration of estrogen to ovariectomized animals markedly stimulated (approximately 10-fold) the level of KAP mRNA in the uterus. Treatment of these animals with progesterone, on the other hand, did not significantly after KAP gene expression. Immunocytochemical analyses of uterine sections with an antibody against KAP exhibited specific staining in both luminal and glandular epithelia and in myometrium. These uterine locations also possess abundant estrogen receptors and are known targets of estrogen action. Our studies, therefore, revealed that KAP is a useful marker of estrogen action in the uterus, especially during the reproductive cycle and termination of gestation.

Animals↗

PubMed1998

Temporal patterns of embryonic gene expression and their dependence on oogenetic factors.

Successful development of a fertilized egg beyond early cleavage divisions requires the de novo initiation and subsequent regulation of embryonic transcription. The egg provides the specialized environment within which the newly formed zygotic nucleus initiates its developmental program and as a result plays an obligatory role in its regulation. Although the precise timing of the onset of embryonic transcription in mammals varies during early cleavage divisions, several common elements exist. In the present essay we review the current literature on the timing and control of embryonic gene expression in mammals, and discuss recent findings from our laboratory on gene expression patterns in bovine embryos and their relation to other species, and zygotic gene activation (ZGA). Lastly, we discuss the putative role of maternally inherited factors in conferring developmental competence to the blastocyst stage, and a method to identify such factors present in oocytes as mRNA.

Animals↗

PubMed1991

[New concepts of breast-feeding, its promotion and the education of health professionals].

Many health professionals and institutions, both national and international, recognize the benefits of breast-feeding for child nutritional status and survival, as well as its importance as a natural contraceptive method. High rates of fertility, malnutrition, and infectious diseases, together with accelerated urban growth and the incorporation of larger numbers of women in the economically active population, have returned breast-feeding to a position of key importance in programs for child survival and family planning. The promotion of breast-feeding involves motivation, training, and coordination of the efforts of many people. Since its success depends more on education and support offered to mothers than on curative care, it is an ideal area for the intervention of nursing personnel, whose initiative in this regard can have a lasting impact on promotion programs. The present article cites the nutritional advantages of breast-feeding, its function in birth spacing, and the sociocultural, economic, and other factors that shape breast-feeding patterns throughout the world. The fundamental importance of health professionals in promotion activities is stressed, as is the need to include course material on breast-feeding in the curricula of nursing schools and other centers for the training of health professionals. A modular scheme is proposed for achieving this last objective.

Breast Feeding↗

PubMedDate not supplied

A simple method for estimating the contraceptive prevalence required to reach a fertility target.

This report describes and applies a procedure for estimating the increase in contraceptive prevalence that would have to occur to achieve specified future reductions in a population's fertility. This target-setting methodology is based on a previously developed analytic model for the relationship between fertility and its proximate determinants. The basic aggregate version of the estimation procedure, which is described in detail, requires relatively few input data, but it allows changes in the mix of contraceptive methods in future years. In extended versions of the model, age specificity and adjustments for given trends in the proximate determinants other than contraceptive use are introduced.

Contraception Behavior↗

PubMed1993

The establishment of underdominant chromosomal rearrangements in multi-deme systems with local extinction and colonization.

The fate of an underdominant chromosomal mutant was investigated in multideme models with high rates of local extinction and colonization. Four models with different patterns of colonization (number of colonists and place of origin of colonists) were studied by performing a large number of computer simulations with the Monte Carlo method for several sets of values of the following parameters: coefficient of selection against the heterozygote, extinction rate of each deme, deme size, and number of demes. The probability of the newly arisen rearrangement being established in the multi-deme system depends strongly on the pattern of colonization, other things being equal. In the three models in which there is absent or scarce mixing of gene pools of different demes when a new deme is founded, the fixation probability of the new chromosomal rearrangement is rather close to that calculated by R. Lande (1979, Evolution 33, 234-251; 1985, Heredity 54, 323-332), which is equal to the corresponding probability in a single deme divided by the number of demes. In the model with extensive mixing of gene pools of demes, the corresponding probability is lower (considerably in some cases). Furthermore, in the models where the fixation probability is higher, the analysis of the time of the process leads to the conclusion that in systems consisting of a large number of demes, overlapping of several different processes of fixation of chromosomal rearrangements occurs.

Animals↗

PubMedDate not supplied

Genotype analyses of Campylobacter isolated from the gastrointestinal tracts and the reproductive tracts of broiler breeder roosters.

Campylobacter is considered to be the leading bacterial etiologic agent of acute gastroenteritis in humans. Evidence implicates poultry as a major source of the organism for human illness; however, the pathways involved in Campylobacter contamination of poultry flocks, horizontal transmission and/or vertical transmission, remain unclear. Recent evidence implicates breeders as a potential source for Campylobacter contamination of the subsequent broiler offspring. In this investigation, Campylobacter isolated from feces, cloacal swabs, ceca, semen, and vas deferens of 12 breeder broiler roosters were genotyped by both flagellin A short variable region (flaA SVR) DNA sequence analysis and repetitive element (rep)-polymerase chain reaction (PCR). In 9 of 12 roosters, Campylobacter was isolated from multiple sites sampled. Comparison of multiple isolates obtained from individual roosters revealed variable results. In five of the nine roosters, all Campylobacter isolated demonstrated closely related flaA SVR DNA sequences as well as rep-PCR patterns; isolates from these roosters were collected from both the gastrointestinal and the reproductive tracts or from the gastrointestinal tract alone. The remaining four roosters had Campylobacter that were distinct by both typing methods. Isolates from two of these four roosters originated from both the gastrointestinal and the reproductive tracts. Isolates from the remaining two roosters originated from only the reproductive tract. Comparisons of all Campylobacter isolates recovered from a distinct sample type within either the reproductive tract or the gastrointestinal tract (feces, semen, cloaca, vas deferens, or ceca) were quite diverse. No relationship between the genotypes and the sample type could be ascertained. Further investigation is needed to determine the route of contamination and if the presence of Campylobacter within the rooster leads to contamination of the broiler offspring via the fertilized egg.

Animals↗

PubMed1988

Case-control study of borderline ovarian tumors: reproductive history and exposure to exogenous female hormones.

Borderline ovarian tumors possess many of the same morphological features as their malignant counterparts, but they do not destructively invade the ovarian stroma, and the women in whom they develop generally have a favorable prognosis. Female residents of three urban counties of western Washington diagnosed with serous and mucinous borderline ovarian tumors between 1980 and 1985 (n = 116) were interviewed regarding past reproductive events. A random sample of women from the same counties (n = 158) was identified through random digit dialing and were interviewed. The risk of these ovarian tumors among women who had given birth to 1 or 2 children and to 3 or more children was, respectively, 0.7 and 0.4 that of nulliparous women. There was no consistent influence of increasing age at first live birth. Adjusting for parity, a history of lactation was associated with a 50% reduction in risk. Among nulliparous women, a further increase in risk was present in those who reported a history of infertility. Use of oral contraceptives was associated with a 60% reduction in risk. However, the size of the association was not dependent on duration, age at first use, or years since last usage. In conclusion, borderline tumors appear to have similar epidemiological patterns with regard to reproductive events as their more malignant counterparts.

Adult↗