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Results for “Fertility Pattern Method”

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PubMed1999

Effects of abnormal light-rearing conditions on retinal physiology in larvae zebrafish.

PURPOSE: Anatomic studies have found that zebrafish retinal neurons develop in a sequential fashion. In addition, exposure to abnormal light-rearing conditions produces deficits in visual behavior of larvae zebrafish, even though there appears to be little effect of the light-rearing conditions on the gross morphology of the retina. The purpose of this study was to assess the effects of abnormal light-rearing conditions on larvae zebrafish retinal physiology. METHODS: Larvae zebrafish (Danio rerio) were exposed to constant light (LL), constant dark (DD), or normal cyclic light (LD) from fertilization to 6 days postfertilization (dpf). After 6 days, the animals were placed into normal cyclic light and tested at 6 to 8, 13 to 15, and 21 to 24 dpf. Electroretinogram (ERG) responses to visual stimuli, consisting of various wavelengths and irradiances, were recorded. Comparisons were made across the three age groups and the three light-rearing conditions. RESULTS: Deficits from the light-rearing conditions were seen immediately after exposure (6 8 dpf). The LL-condition subjects showed the greatest deficit in the UV and short-wavelength areas and the DD-condition subjects showed a slight deficit across the entire spectrum. At 13 to 15 dpf, the LL and DD groups showed an increase in sensitivity and by 21 to 24 dpf, the groups no longer differed from controls. CONCLUSIONS: Abnormal lighting environments can adversely influence the physiological development of the larvae zebrafish retina. The pattern of damage that was seen in zebrafish is similar to that found in other vertebrates, including higher vertebrates. However, unlike higher vertebrates, the zebrafish appears to be capable of regeneration. This suggests that the zebrafish would be a viable model for light environment effects and neural regeneration.

Animals↗

PubMed1988

Use of pulsatile intravenous administration of gonadotropin-releasing hormone to induce fertile estrus in bitches.

The pulsatile IV administration of gonadotropin-releasing hormone (GnRH) was evaluated as a method to induce fertile estrus in 8 anestrous Beagle bitches. Bitches received 1.25 micrograms of GnRH every 90 minutes for 11 to 13 days. Gonadotropin-releasing hormone was delivered by use of an automatic pump. Reproductive history was known for all bitches, 4 of which, on the basis of 3 or 4 preceding cycles, had an interestrous interval of 219 +/- 14 days (mean +/- SEM). Estrus induction was attempted during early anestrus in 6 bitches (ie, 148 +/- 10 days since the preceding estrus) and late anestrus in 1 bitch (ie, 260 days since the preceding estrus); another bitch had not had an estrous cycle for nearly 2 years before GnRH administration. Signs of estrus were seen within 16 days after the start of GnRH administration in the bitches with regular estrous cycles (group 1, n = 7), and within 23 days in the bitch (group 2) with prolonged anestrus. All bitches were bred, and 7 of 8 (87.5%) became pregnant, with a mean litter size of 4.5 +/- 0.75. A normal hormonal response pattern was observed in group-1 bitches--a peak increase in plasma estrogen concentration of 22.3 +/- 2 pg/ml immediately before the onset of estrus. Peak plasma progesterone concentration (17.3 +/- 3 ng/ml) was observed 1 to 14 days after the onset of diestrus in the group-1 bitches that ovulated, and adequate plasma progesterone concentration was maintained throughout gestation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2005

Effects of folic acid fortification on twin gestation rates.

OBJECTIVE: Previous studies have reported an increase in twinning of as much as 40% associated with folic acid-containing supplements, and folic acid fortification of enriched cereal grains was authorized in 1996. The purpose of this study was to investigate whether twinning rates have increased since that time. METHODS: We used United States birth and fetal death records to calculate twin gestation rates from 1990 through 2000. To eliminate the influence of fertility treatments, our analysis was limited to nulliparous women aged 16-19. We compared time trends in twin gestation rates before and after folic acid fortification in 1996. RESULTS: A total of 25,065 twin and 3,362,245 singleton pregnancies were included. Twin gestation rates were stable from January 1990 through December 1996, at 7.2 per 1,000, and then began a steady increase, averaging 2.4% (95% confidence interval 0.1-4.2%, P = .006) per year, which continued through 2000 and reached 8.2 per 1,000. This translates to 2 additional twin pregnancies per 10,000 gestations per year. Twin rates continued to increase well beyond 1998, when the maximal fortification effect on folate status had been reached. CONCLUSION: Although twin gestation rates in women not using fertility treatments increased after food fortification with folic acid, they rose by much less than the 40% rate previously reported; the observed pattern of increase in twin gestation rates is not consistent with a folic acid fortification effect. LEVEL OF EVIDENCE: II-2.

Adolescent↗

PubMed1988

Determinants of menstrual bleeding patterns among women using natural and hormonal methods of contraception. I. Regional variations.

Records of the occurrence of vaginal bleeding were obtained from women using either a natural method of contraception or one of four types of hormonal contraceptive. The relationships between their bleeding patterns and a number of demographic variables were examined, with the aim of identifying subgroups of women who, if they used a particular hormonal method of contraception, would be likely to suffer more or less disruption to their bleeding pattern than the 'norm'. Within contraceptive method, bleeding patterns were more closely related to the women's geographical region of residence than to any other factor. Some of the differences between regions were consistent across contraceptive methods. European women tended to have more bleeding/spotting days than women in other regions; Latin American women had relatively short episodes and long bleeding-free intervals, whether they were using the ovulation method, combined pills or a vaginal ring. Other differences were method-specific. Women using combined pills in India or Pakistan had fewer spotting episodes than women using the same method elsewhere; those using progestogen-only pills had more. Regional variations in bleeding patterns were particularly marked among women using DMPA, and increased over time: by their fourth injection interval, 25% of European women had amenorrhea, as compared with 72% of subjects in North Africa. These findings need to be confirmed by carefully controlled studies of menstrual bleeding patterns and their acceptability in various ethnic groups. The results would be valuable in counselling new contraceptive acceptors, and could eventually guide the choice of methods for introduction into national family planning programmes.

Administration, Intravaginal↗

PubMed1992

[Fertility of women married before 1800 at Jablonec nad Nisou].

Using data from parish registers and family reconstitution methods, the authors analyze fertility levels and trends for women married before 1800 in the town of Jablonec nad Nisou, Czech Republic. "Analyzing matrimonial fertility of these families we have found...that during the whole 18th century the level of matrimonial fertility...was stable.... The number of children in a family depended on the age of woman at the time of marriage and length of marriage duration." (SUMMARY IN ENG AND RUS)

Birth Rate↗

PubMed1980

Aminergic systems in pulmonate gastropod molluscs. III. Microspectrofluorometric characterization of the monoamines in the reproductive system.

Histochemical fluorescence (Falck-Hillarp) and microspectrofluorometric (MSF) methods were used to characterize different types of catecholamine-containing cellular elements located in the reproductive system of fresh-water snails (Bulinus truncatus, Planorbarius corneus) and land snails [Archachatina marginata, Helix (Cryptomphalus) aspersa]. Transverse sections through the genital tract display a common structural pattern of tubular differentiations: (1) an internal epithelium bordering the lumen and containing variable numbers of monoaminergic cells; (2) an enveloping sheath of connective and muscular tissue containing fine nerve fibers in the form of a network that exhibits a variable degree of density. MSF determinations showed that the formaldehyde-induced fluorophores of the intraepithelial aminergic cells belong to the following classes: (1) the DOPA/dopamine group in the duct of the albumen gland of B. truncatus and the carrefour of A. marginata; and (2) the norepinephrine/epinephrine group in the duct of the albumen gland and in the oviduct sac of P. corneus. In the reproductive systems of B. truncatus and P. corneus (duct of the albumen gland, oviduct sac, vagina), A. marginata and H. aspersa (duct of the fertilization pocket, origin of the receptaculum seminis, carrefour), the MSF analysis revealed norepinephrine/epinephrine-containing intramural nerve fibers. On the other hand, the small neurons in the vagina of B. truncatus belong to the DOPA/dopamine group.

Animals↗

PubMed2005

Location of micropyles and early embryonic development of the two-spotted cricket Gryllus bimaculatus (Insecta, Orthoptera).

Early embryogenesis of the two-spotted cricket Gryllus bimaculatus was examined by scanning electron microscopy and several fluorescence staining methods, with special reference to these four issues: (i) the location of micropyles; (ii) the transfer of the female pronucleus following meiosis; (iii) the timing of cellularization; and (iv) the process of the germ primordium formation. Between two and four micropyles lie in the mid-ventral region of the egg. The egg nucleus is at the mid-dorsal periphery of the new laid egg, and meiosis resumes and is completed there. The female pronucleus moves to the mid-ventral side, and fertilization occurs there. Energid starts to proliferate and migrates to the periphery of the egg, initiating blastoderm formation. Actin caps surround each superficial nucleus. Cellularization occurs during the blastoderm stage. At a late blastoderm stage, nuclei aggregate in both the posterolateral patch-like regions of the egg to form a germ primordium. The germ primordium looks like a pair of dumbbells. Both the patches shift towards the ventral side and fuse into a germ primordium. The germ primordium contracts to produce a clearly delineated germ band. Observations on distribution patterns of F-actin indicate that, all through the process, the germ primordium retains that unity, and is not separated into two parts.

Actin Cytoskeleton↗

PubMed1999

Outcome and reproductive function after chemotherapy for ovarian dysgerminoma.

PURPOSE: To review the outcome for all patients with ovarian dysgerminoma treated at the M.D. Anderson Cancer Center who received bleomycin, etoposide, and cisplatin (BEP) and to assess the menstrual and reproductive function of those who received conservative treatment. PATIENTS AND METHODS: Clinical information was abstracted from the medical record. Patients completed a detailed questionnaire about menstrual and reproductive function; those who did not return the questionnaire were interviewed by telephone. RESULTS: Twenty-six patients were identified as having been treated with BEP chemotherapy for pure ovarian dysgerminoma from January 1984 to January 1998. Their median age was 19.5 years (range, 7 to 32 years). Sixteen patients underwent fertility-sparing surgery in the form of unilateral salpingo-oophorectomy. At a median follow-up time of 89 months, 25 (96%) of the 26 patients remained continuously disease-free. One patient apparently developed a second primary dysgerminoma in her remaining ovary after BEP and was clinically disease-free after further treatment. Of the 16 patients who underwent fertility-sparing surgery, one was lost to follow-up when she was pregnant, and one was still premenarchal. Of the remaining 14 patients, 10 (71%) maintained their normal menstrual function during and after chemotherapy, and 13 (93%) had returned to their prechemotherapy menstrual pattern at the time of the questionnaire. Five pregnancies have occurred thus far, and two patients have had difficulty conceiving. CONCLUSION: Most patients with metastatic dysgerminoma can expect cure with maintenance of normal reproductive function when treated with conservative surgery and BEP chemotherapy.

Adolescent↗

PubMed1982

Development of horse embryos up to twenty two days after ovulation: observations on fresh specimens.

Forty nine embryos, twenty unfertilized eggs and five other fresh eggs of 'doubtful' status have been recovered from 58 pony mares in 122 flushes up to 22 days after ovulation. The fresh egg or embryo recovery rate was 78% with surgical methods (or at slaughter) and 40-60% with non-surgical methods of recovery. The fertilization rate was about 70%. It has been confirmed that horse embryos normally enter the uterus as blastocysts 5-6 days after ovulation. Three features of early embryo morphology have become clearer upon comparison with unfertilized eggs of similar ages; early embryos are often ellipsoidal in shape; dispersal of most of a thick gel coat seems to be hastened by fertilization; gradual disappearance of refractile granules from the perivitelline space is similar in fertilized and unfertilized eggs. A tense, transparent, acellular capsule (considered to be different from the zona pellucida) is acquired by the spherical blastocysts within the uterus and persists at least until a diameter of 34 mm is attained (at 21 days in the present series). The capsule seems to be analogous, in part, with the 'neozona' described in rabbit blastocyst before attachment, and trophoblastic cells appear to be involved in its formation. Cleavage stages of oviductal embryos and diameters of uterine blastocysts from this series have been described and illustrated and used to extend previous knowledge of early growth patterns in horse embryos.

Animals↗

PubMed2004

Marker-assisted selection in segregating generations of self-fertilizing crops.

Computer simulations were used to study the efficiency of MAS for breeding self-fertilizing crops, based on a general model including additive, dominance and epistasis. It was shown that MAS not only gave larger genetic responses but also dramatically increased the frequencies of superior genotypes as compared with phenotypic selection. However, the advantages of MAS over phenotypic selection were considerably reduced when conducting selection in later generations. A modified method combining MAS in early generations with phenotypic selection in later generations was thus proposed from an efficiency standpoint. We also proposed a potential index to measure the probability of an individual showing superior genotypes under selfing. It was apparent that more superior genotypes could be derived from selection by using the potential index than by using other methods. The implications of these findings for plant breeding are discussed.

Breeding↗

PubMed1989

Monospermy and polyspermy after partial zona dissection of reinseminated human oocytes.

Partial zona dissection (PZD), a zona drilling method that uses mechanical force to open the zona pellucida while the oocyte is shrunken in a sucrose solution, was applied to 121 unfertilized 1-day-old mature human oocytes prior to reinsemination. The 115 surviving oocytes were divided into three groups in which the duration between sucrose addition and reinsemination was varied: I) Less than 20 minutes, II) 21 to 45 minutes, and III) longer than 45 minutes. There was a trend toward a reduced fertilization and polyspermy rate as the time between sucrose exposure and insemination in sucrose-free medium increased. Moreover, there was a statistically significant reduction in the number of oocytes penetrated by more than four sperm in group III (0/41) versus group I (7/34), and in group III, parthenogenetic development was observed. The incidence of polyspermy was also increased in oocytes manipulated more than 25 hours after retrieval compared with those manipulated 21-24 hours after recovery, supporting the idea that aged oocytes have a reduced ability to block polyspermy. Oocyte contraction in sucrose occurred in three different patterns: spherical, pear-shaped, and crenated. Both the fertilization and polyspermy rates were significantly higher in the crenated group. These results indicate that changes resembling activation occur following sucrose exposure and that sucrose activation can be used to reduce the risk of polyspermic fertilization in zona drilling procedures. In addition, the pattern of shrinkage in sucrose can be used as an indicator of oocyte receptivity to sperm penetration.

Cell Membrane↗

PubMed2005

Predictive factors for embryo implantation potential.

In spite of recent improvements in IVF, pregnancy rates have not increased significantly and one of the major problems remains the high multiple pregnancy rate. Better criteria are therefore necessary to establish the viability of a transferable embryo. Early prognosis of the developmental fate of the oocyte would help in selecting the best embryos to transfer, but non-invasive selection at the oocyte stage (extracytoplasmic and intracytoplasmic morphology) has proved to be of little prognostic value. Recently, it has been shown that follicular vascularization appears to be predictive of oocyte developmental fate, making it a good first-step approach for selection. Observation of pronuclei patterns at the zygote stage appears to offer an additional prognostic tool, correlating well with IVF outcome. Morphological evaluation of the embryo at days 2-3 remains the most used and valid method of selection, even though it is not sufficient to select embryos with the higher implantation potential. Blastocyst culture is another possible strategy for selecting the best embryos with reduced risk of aneuploidies, though not all major chromosomal aberrations are excluded by prolonged in-vitro culture. In summary, selecting the best embryo for transfer is a decision that should be based on choices made during the different stages of assisted reproductive technologies.

Blastocyst↗

PubMed2001

Evaluation of pronuclear morphology as the only selection criterion for further embryo culture and transfer: results of a prospective multicentre study.

BACKGROUND: The aim was to study zygote evaluation based on pronuclear morphology under the German embryo protection law, according to which only a maximum of three zygotes are allowed to be cultured for embryo transfer. METHODS: In this prospective multicentre study, a total of 512 treatment cycles was performed at 10 centres, between November 1999 and October 2000. Zygotes were classified into seven patterns (0A, 0B and 1-5). Pattern 0A and 0B zygotes were preferentially used for further culture and transfer. RESULTS: Cycles with transfer of at least one embryo derived from pattern 0B, but not pattern 0A, resulted in significantly higher pregnancy (37.9%) and implantation rates (20.5%) compared with non-pattern 0B cycles (26.4 and 15.7%; P < 0.05 and P < 0.01 respectively). In younger patients (aged < or =35 years), significantly more 0B zygotes were available for transfer than in older patients (34.2 versus 25.8%; P < 0.005). CONCLUSIONS: From these data, it is concluded that evaluation of pronuclear morphology is beneficial, especially for countries with legal restrictions regarding embryo selection.

Adult↗

PubMed1990

Family planning through private practitioners: characteristics of Kenyan contraceptive acceptors.

Kenya has one of the highest population growth rates in the world. Innovative programs are therefore called for to help curb the fast population growth rate. The Kenya Medical Association started a new program of involving private physicians in the active provision of family planning services. A preliminary analysis shows that the program serves generally young, better educated women of low parity. Sixty-one percent of the clients are new acceptors and the oral contraceptive pill the most popular method. The level of education of the clients had marked influence on family size. Age, parity and marital status also influenced the pattern of contraceptive use. These preliminary results are discussed against the background of the 1984 Kenya Contraceptive Prevalence Survey findings and possible areas of improvement suggested.

Adolescent↗

PubMed1985

The progestagen releasing vaginal ring.

The results of the Manchester study and its reinforcement from data from the multicenter study indicate that the ring is a well-tolerated delivery system for low-dose progestagens. The expulsion rate is low and vaginal tolerance satisfactory. The pregnancy rate and bleeding pattern is of the same order as oral low-dose progestagens. Indeed, there is an indication that the pregnancy rate and abnormal bleeding rate may be even lower. Data from other more extensive phase 3 studies will be required to confirm this impression. The subjective assessment is that the majority of patients are enthusiastic about this method of contraception, bearing in mind that many of them had become disenchanted with existing marketed contraceptive methods. Because of its high level of acceptability, the gap between theoretical and use-effectiveness in narrowed and once inserted, a high degree of motivation is not required since the existing ring only needs to be reinserted after 90 days of use. The acceptability of vaginal methods of contraception as evidenced by the rapid uptake of the vaginal sponge suggests that there is considerable potential for increased use of vaginal methods. In the present state of knowledge, it would appear that the woman for whom the progestagen only conception is particularly appropriate is the one who is lactating or for the older woman whose fertility is on the wane. For the woman who wishes to space her family, the progestagen only contraceptive is also appropriate. With increased refinements and experience of this method, there is a likelihood that the ring may extend the use and application of progestagen only contraception to a wider range of potential patients.

Biology↗

PubMed1991

Reproductive factors and colorectal cancer risk among Chinese females.

We report results from a population-based case-control study of colorectal cancer among Chinese women in western North America (NA) and the People's Republic of China (China). A common protocol was used to assess reproductive characteristics and hormone use of 395 Chinese women (189 from NA and 206 from China) with cancer of the colon or rectum and of 1112 age-matched Chinese controls (494 from NA and 618 from China). In NA, risks for cancers of both the colon and rectum were lower among parous compared to nulliparous women (odds ratio for colorectal cancer, 0.6, P = 0.08), but the trend in risk was not smooth with increasing number of livebirths. This association with parity was absent for both cancer sites in China. There were no consistent patterns in the relationships between other reproductive factors (including age at menarche, age at first livebirth, menopausal status) and risk of colon and rectal cancer on either continent.

Adult↗

PubMed2004

Anaphase lagging mainly explains chromosomal mosaicism in human preimplantation embryos.

BACKGROUND: Cleavage stage embryos as well as postimplantation embryos have been studied extensively over the years. However, our knowledge with respect to the chromosomal constitution of human embryos at the blastocyst stage is still rudimentary. METHODS: In the present paper, a large series of human blastocysts was examined by means of fluorescent in situ hybridization (FISH). RESULTS: It was found that only one in four blastocysts (25%) displayed a normal chromosomal pattern. We defined a group of blastocysts (26%) displaying a simple mosaic chromosome pattern (different cell lines resulting from one chromosomal error), an about equally large group of blastocysts (31%) displaying a complex mosaic chromosome pattern, and a smaller group of blastocysts (11%) showing a chaotic chromosome distribution pattern. Six per cent of all blastocysts analysed could not be assigned one of the previously mentioned chromosomal patterns. CONCLUSION: Anaphase lagging appeared to be the major mechanism through which human embryos acquire a mosaic chromosome pattern during preimplantation development to the blastocyst stage.

Anaphase↗

PubMed2004

Autonomic dysfunction may be an under-recognized cause of female fertility disorders.

Female conditions of impaired fertility comprise a heterogeneous group of disorders that are attributed to various anatomic, hormonal and immunologic disturbances. We hypothesize that autonomic dysfunction may be a previously unrecognized factor in female fertility disorders. Emerging physiologic and molecular evidence suggests that autonomic balance varies during normal menstrual cycles with a shift to sympathetic bias during the luteal phase. Furthermore, many diseases associated with autonomic dysfunction show catamenial variations in patterns consistent with a shift to sympathetic bias occurs during the second half of normal menstrual cycles. The shift to sympathetic bias during the normal luteal phase may be an evolutionary adaptation to address the immunologic and physiologic demands for successful implantation and gestation. Through direct modulation of the lymphoid system and activation of the cortisol pathway, sympathetic bias promotes a shift to relative T helper (Th)-2 biased immunity which may favor maternal tolerance of the embryo by attenuating Th-1 mediated interference of implantation. Indeed, a growing body of evidence has implicated abnormal Th balance in fertility disorders, but the link has been attributed to factors other than autonomic function, such as hormonal factors. After implantation, maternal sympathetic bias may further support gestation through physiologic changes necessary to maintain placental perfusion pressure. We propose that insufficient shift to sympathetic bias during the luteal phase, which manifests in inadequate shift towards Th-2 bias and down-regulation of Th-1 function, may be the mechanism of impaired fertility in certain patients. Our hypothesis portends new potential methods to treat fertility disorders by modulating autonomic balance.

Autonomic Nervous System Diseases↗