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PubMed1997

Short stature: an obstetric risk factor? A comparison of two villages in Tanzania.

BACKGROUND: A short maternal stature is associated with an increased risk of obstructed labor due to cephalopelvic disproportion and most antenatal programs, including that of Tanzania, designate short women as 'at risk'. OBJECTIVE: To determine mean maternal height in two obstetric populations and the effect, if any, of maternity care practices pertaining to maternal height, on interventions and outcome of pregnancy and delivery. METHODS: A community based study of pregnancy outcome for women in two villages in rural Tanzania of different profiles and ethnicity. RESULTS: In Ilula 54% of cesarean sections were in the 4% of women under 150 cm and 39% of short women delivered in hospital. In Ikwiriri 23% of parturients were under 150 cm and height did not correlate to the duration of labor, referral patterns or Cesarean section rates. There are indications that fertility rate is reduced in short women in Ilula but not in Ikwiriri, a result of the problems and risks of Cesarean section for women living in rural areas. CONCLUSIONS: The distribution of maternal height in the population should be considered when the cut-off height for the 'at risk' designation is chosen. The implications of attaching an 'at risk' label is discussed and a call is made for regional specific and agreed risk criteria.

Adult↗
PubMed1981

Early localization of alpha-fetoprotein in the developing nervous system of the chicken.

The intracellular presence of alpha-fetoprotein (AFP) and serum albumin (SA) has been recently demonstrated in the developing brain of primates, rats and mice. We report here the morphologic localization by immunocytochemical methods of AFP, SA, ovalbumin (OA) and immunoglobulin G (IgG) in the nervous system of chicken embryos. AFP was detected inside cells of the neural crest as soon as 48 hours after fertilization. Subsequently, the protein could be localized in many other neural structures, including cerebral cortex, brain stem nuclei, sensory retina, spinal cord and dorsal root ganglia. Disappearance of AFP inside the nervous system was observed 15 to 17 days after fertilization. The localization pattern of SA was similar to that of AFP, with the only difference being a short (2 to 3 days) displacement in time. On the contrary, OA and IgG were not found in the developing nervous system throughout the period examined. This provides support to the selectivity of the neural internalization of AFP and SA, and seems to exclude a mechanism of passive diffusion to explain such incorporation.

Animals↗
PubMed2005

Doses of levonorgestrel comparable to that delivered by the levonorgestrel-releasing intrauterine system can modify the in vitro expression of zona binding sites of human spermatozoa.

BACKGROUND: The levonorgestrel-releasing intrauterine system (LNG-IUS) exerts its contraceptive effect by interfering with sperm transport through the female genital tract and with ovulation. However, the possibility cannot be discarded that the device exerts a direct effect on sperm function, thus, helping prevent fertilization. OBJECTIVES: The purpose of this study is to evaluate whether LNG at doses comparable to that measured in the uterus during the use of the LNG-IUS affects the detection of D-mannose binding sites or zona pellucida (ZP) receptors on human spermatozoa. The association with acrosomal status was also investigated. METHODS: Seventeen semen samples from fertile men were used, and spermatozoa were separated using a Percoll gradient and incubated for 22 h at 37 degrees C under 5% CO(2) in air. Capacitated spermatozoa were exposed for 30 min to 1,000 or 10,000 ng/mL of LNG or control medium. D-Mannose binding sites were detected using commercial D-mannosylated bovine serum albumin conjugated with fluorescein isothiocyanate, and the percentage of specific patterns (II and III) was recorded. The acrosome reaction was evaluated using the Pisum sativum technique. RESULTS: Levonorgestrel releasing significantly increased (p < .001) the percentage of spermatozoa with D-mannose receptors localized in pattern III, and this increase was dose dependent and a significant increase (p < .001) in the percentage of acrosome-reacted spermatozoa. Double staining confirmed an association between the location of the zona receptor and acrosomal status. RESULTS: The in vitro exposure of capacitated spermatozoa to the assayed doses of LNG increased the proportion of spermatozoa with fewer chances of interacting with the ZP. Further studies should be carried out to confirm whether this mechanism is part of the contraceptive action of the LNG-IUS.

Acrosome Reaction↗
PubMedDate not supplied

Hyperactivated motility of human spermatozoa: a review of physiological function and application in assisted reproduction.

Hyperactivated motility is a specific movement pattern which has been recognized in mammalian spermatozoa for over 25 years. During this time, it has been established that hyperactivation is part of the complex process of sperm capacitation, which is necessary before fertilization can occur. The recent introduction of computed sperm motility analysis has allowed detailed studies of sperm movement characteristics to be undertaken, and evidence is accumulating that hyperactivated motility may correlate with fertility. In this review, the physiological consequences of hyperactivated motility, methods of measurement and their application in assisted reproduction are discussed.

Animals↗
PubMed2005

Association of partial AZFc region deletions with spermatogenic impairment and male infertility.

BACKGROUND: Complete deletions of the AZFc region in distal Yq are the most frequent molecular genetic cause of severe male infertility. They are caused by intrachromosomal homologous recombination between amplicons--large, nearly identical repeats--and are found in 5-10% of cases of azoospermia and severe oligozoospermia. Homologous recombination may also generate different partial deletions of AZFc, but their contribution to spermatogenic impairment has not been confirmed. METHODS: In this study we analysed the prevalence and characteristics of different partial AZFc deletions and their association with spermatogenic failure. We studied 337 infertile men with different spermatogenic impairment and 263 normozoospermic fertile men using AZFc specific sequence tagged site markers and DAZ specific single nucleotide variants. RESULTS: We identified 18 cases of partial AZFc deletions in the infertile group (5.3%) and one case in the control group (0.4%). Seventeen deletions had the "gr/gr" pattern, one the "b2/b3" pattern, and one represented a novel deletion with breakpoints in b3 and b4 amplicons. Partial AZFc deletions were associated with different spermatogenic phenotypes ranging from complete azoospermia to only moderate oligozoospermia. CONCLUSIONS: Together with published data, our analysis of DAZ gene copy suggested that the contribution of the different deletions to male infertility varies: only partial AZFc deletions removing DAZ1/DAZ2 seem to be associated with spermatogenic impairment, whereas those removing DAZ3/DAZ4 may have no or little effect on fertility. These data show that, beside complete AZFc deletions, specific partial deletions represent a risk factor for male infertility, even if with different effect on spermatogenesis.

Adult↗
PubMed1982

The measurement of urinary steroid glucuronides as indices of the fertile period in women. World Health Organization, Task Force on Methods for the Determination of the Fertile Period, special programme of research, development and research training in human reproduction.

The concentrations of various estrogen glucuronides and pregnanediol-3 alpha-glucuronide have been measured in daily samples of early morning urine (EMU) and 24 h pooled collections throughout a total of 70 menstrual cycles (58 subjects). The immediate objective was to identify and assess the potential value of measuring hormone metabolites to locate the fertile period in women, with the ultimate aim of developing a non-invasive immunochemical test. The project was undertaken in five centres and the results showed that: (i) there was good agreement in the patterns and mean concentrations of metabolites between the centres; (ii) estrone-3-glucuronide should be the estrogen glucuronide selected for further study; (iii) the analysis of EMU provided information that was as useful as the corresponding measurements on pooled collections for 24 h; (iv) a rise in the concentration of estrone-3-glucuronide (50% over the mean of three preceding values) could be used to locate the start of the fertile period in greater than 90% of the ovarian cycles (from day LHmax -- 3 to day LHmax -- 7); attempts to locate the end of the fertile period by a threshold value or a defined rise in the level of pregnanediol-3 alpha-glucuronide were disappointing. A 50% rise over the mean of three preceding values in the derived concentration ratio of estrone-3-glucuronide/pregnanediol-3 alpha-glucuronide could be used to indicate the start of the fertile period, and a 50% decrease plus two days the start of the infertile period in greater than 80% of the ovarian cycles. The limitations, implications and future developments are discussed.

Adolescent↗
PubMed2002

Breastfeeding patterns and return to fertility in Australian women.

OBJECTIVE: The purpose of this study was to understand the relationship between infant feeding patterns and the return of fertility during lactation. DESIGN: Mother-infant pairs were followed up prospectively from the first week postpartum until the return of two normal menstrual bleeds (as judged by the woman) or pregnancy SETTING: This study was conducted in the Sydney and Melbourne areas of Australia, and was part of a seven-country research project. SAMPLE: Six hundred and twenty-four Australian mother-infant pairs participated in the study METHODS: Follow-up interviews occurred in the mothers' homes every two weeks. Mothers completed a daily diary record chart of vaginal bleeding and infant feeding, and completed a detailed diary card of the time and duration of breastfeeds and the frequency and nature of all other feedings once every two weeks. MAIN OUTCOME MEASURES The main outcomes of the study were measured as the median duration of lactational amenorrhoea and lifetable pregnancy rate during lactational amenorrhoea. RESULTS: The median duration of amenorrhoea in the Australian breastfeeding women who participated in the study was over 8.5 months. Breastfeeding was shown to be an effective method of fertility control in that no non-contracepting, sexually active, amenorrhoeic, breastfeeding woman became pregnant in the first six months after delivery. Regular supplements commenced on average at five months and the Australian women rarely introduced noncaloric (water), caloric (juices), or milk-based supplements before this time. CONCLUSIONS: This confirmed the Bellagio Consensus and the effectiveness of the Lactational Amenorrhoea Method.

Amenorrhea↗
PubMed2006

Comprehensive analysis of ovarian gene expression during ovulation using differential display.

Mammalian ovulation is a normal biological process that is initiated when a gonadotropic hormone stimulates G protein-coupled receptors in the plasma membrane of cells in ovarian follicles. This article outlines differential display (DD) protocols and associated methods that have been used to discover more than 30 genes that are expressed in the rat ovary during the ovulatory process. Details are provided regarding the methods for total RNA extraction, reverse transcription (RT), DD-polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE), Northern analysis of the differentially expressed cDNA fragments, cloning of the cDNA fragments, sequencing of the cDNA, and in situ hybridization of the cDNA fragments with sections of ovarian tissue. These methods provide clear evidence of the temporal and spatial patterns of expression of ovulation-specific genes in the ovary. Most of the genes that have been discovered to date have been associated previously with cascades of gene expression in acute inflammatory reactions. Therefore, the data support the working hypothesis that the ovary becomes inflamed at the time of ovulation, and this acute condition softens local connective tissues and causes ovarian follicles to rupture and release fertile eggs.

Animals↗
PubMed2005

Gene disruption/knock-in analysis of mONT3: vector construction by employing both in vivo and in vitro recombinations.

We report the isolation, spatial/temporal expression and gene disruption phenotype of the mouse ONT3 (mONT3) gene, which encodes a novel secreted signaling protein belonging to the Olfactomedin/Noelin/Tiarin family. During early embryogenesis, mONT3 is detected in the proximal region of the allantois on embryonic day (E) 7.25, in the lateral plate mesoderm on E 8.0 and in the CNS and heart on E 8.5. The homozygous mutant is born normal and fertile. For the expression pattern and loss-of-function analyses, we have successfully generated the LacZ-knock-in targeting vector directly from BACs carrying mouse genomic fragments by combining in vivo and in vitro recombination techniques. This approach enables rapid and reproducible construction of the fully functional vectors within two weeks without the use of restriction enzyme digestion and ligation, or the use of PCR-amplification of large genomic fragments. In addition, this method is applicable to rapid generation of transgenic vectors, demonstrating its versatility in reverse genetic studies.

Alleles↗
PubMed2001

Stem growth and respiration in loblolly pine plantations differing in soil resource availability.

Stem respiration and growth in 10-year-old loblolly pine (Pinus taeda L.) plantations were measured monthly during the third year of fertilization and irrigation treatments to determine whether soil resource availability differentially altered growth and respiration in stem tissue. Fertilized trees had significantly greater stem biomass, stem nitrogen concentration ([N]) and growth rate than unfertilized trees. Stem respiration (Rt) was significantly greater in fertilized trees when expressed on a per unit surface area (Rt,a, micromol CO2 m-2 s-1), sapwood volume (Rt,v, micromol CO2 m-3 s-1), or mass (Rt,w, nmol CO2 g-1 s-1) basis; however, there was no difference between treatments when expressed as a function of stem N content (Rt,n, micromol CO2 (mol N)-1 s-1). Irrigation had no significant effect on Rt or annual stem growth. Daily total respiration (Rd, mol CO2 m-2 day-1) and stem diameter growth both had a seasonal bimodal pattern with peaks in early spring and midsummer. Stem [N] declined significantly during the growing season. Stem growth rate and [N] explained 75% of the seasonal variation in temperature-normalized Rt,a. The mature tissue method was used to partition total stem respiration (Rt) into maintenance (Rm) and growth (Rg) components. There was a linear correlation between winter Rt,v, a measure of basal Rm, and sapwood N content; however, Rt,v per unit N was greater in January before diameter growth started than in the following December after growth ceased, indicating that Rt,v declined as stem diameter increased. Consequently, estimates of annual maintenance respiration (RM) based on January data were 44% higher than estimates based on December data. Growth respiration was correlated with stem growth rate (r2 = 0.55). The growth respiration coefficient (rg)-the slope of the relationship between Rg and stem growth rate-was 0.24. Respiration accounted for 37% of annual stem carbon budget. Stem carbon-use efficiency (CUE)-the ratio of stem growth to stem growth plus respiration-averaged 0.63 and was unaffected by fertilization.

Cell Respiration↗
PubMed1997

Human endometrial leukemia inhibitor factor (LIF) secretion and its relationship to sonographic endometrial appearance.

PROBLEM: LIF is believed to be involved in human reproduction. Because little is known about the function of this cytokine in proliferative phase of cycle and because LIF is found to regulate the cellular growth we evaluated the possible relationship between endometrial LIF secretion and endometrial growth. METHOD: The present is prospective, blinded study with clinical and immunobiochemical correlation between endometrial LIF concentration and endometrial ultrasound pattern. Twenty-four patients who were candidates for IVF and oocyte donation are included in this study. At day 10 of their cycle the endometrial biopsy was performed, followed by vaginal sonographic measurements of endometrial thickness and pattern. Endometrial LIF concentration was measured by ELISA in supernatants taken from cultured explants. RESULTS: Endometrial LIF production significantly negatively correlated with endometrial thicknesses (P < 0.05). There was a 4-fold elevation in LIF production when the endometrial thickness was below 5 mm. Strong correlation was found also between endometrial LIF production and sonographic endometrial pattern (P < 0.05). The most significant amount of LIF was found in nonfavorable endometria. CONCLUSION: In the proliferative phase of cycle there is a dynamic relationship between endometrial sonographic appearance and local LIF secretion. Specifically LIF production is negatively correlated with endometrial thickness and pattern. The low amount of cytokine is a normal uteral environment for endometrial development, whereas deregulation of cytokine production toward its overexpression may lead to a strong inhibitory effect on endometrial growth. This finding might have an important clinical implication.

Adult↗
PubMed2006

[Gene cloning and expression analysis of a male sterility related gene BoDHAR from broccoli].

A differentially expressed cDNA fragment obtained from a cDNA-AFLP analysis, which performed on floral buds of male sterile and fertile lines of cabbage, was used as a querying probe to blast the Genbank and Arabidopsis databases. Based on the assembled homologous cDNA sequences, a full-length cDNA of 633 bp for BoDHAR was cloned by RT-PCR. Furthermore, we have experimentally cloned and sequenced the 5' flanking sequence of gene BoDHAR by genomic walking method based on ligation-mediated PCR. The full length DNA sequence with 1486bp, containing two introns, was achieved. Homologous analysis shows that gene has 82.3% identity at nucleotide level, and 79.6% identity at amino acid level with Arabidopsis dehydroascorbate reductase (DHAR) gene AT1 G19570.1. Structurally, BoDHAR encodes a polypeptide of 210 amino acids, which contains a GST-c-DHAR domain highly conserved among other members of the DHAR superfamily and has multiple phosphorylation sites. Promoter predictions software indicated that the 5' upstream region contained putative transcription signals and conserved sequences, one CAAT-box, one G-box and four TGAC-like motifs. To advance our understanding of gene BoDHAR, tissue expression pattern were analyzed by semi-quantitative RT-PCR. The results indicate that expression level of gene BoDHAR is higher in fertile buds than that in sterile buds, and expressed intensively in the anther.

Amino Acid Sequence↗
PubMed2006

[Differentially expressed genes between a fertile patient and an infertile patient in a large Chinese androgen insensitivity syndrome pedigree].

OBJECTIVE: To screen and identify differentially expressed genes between a fertile patient and another infertile patient who belonged to a large Chinese pedigree affected with androgen insensitivity syndrome (AIS). METHODS: We constructed the forward and reversed subtracted libraries using genital skin fibroblasts (GSF), which were obtained from the fertile patient MJ and infertile patient ZGJ, as tester respectively. Candidate clones were screened with colony in situ hybridization, dot blot, and Southern blot analysis step by step and conformed with Northern blot analysis. The potential positive clones were sequenced and the homology of the sequences was analyzed. RESULTS: The forward and reversed subtracted libraries containing differentially expressed pattern of two GSF cell lines were constructed. Two positive clones identified by Northern blot were obtained in the reversed subtracted library. Eleven candidate clones from the two libraries that failed to hybridize with both RNA populations were obtained simultaneously, which might represent differentially expressed low abundance transcripts. Sequencing results and homology analysis demonstrated that the two positive clones were significantly homologous with the genes of autotaxin-t and calcium binding protein calcyclin (S100A6), respectively. CONCLUSIONS: Two positive clones and eleven clones showing no hybridization signals may represent differentially expressed genes between the two GSFs. This finding may be useful to elucidate the molecular mechanisms leading to phenotypic variation and preserved fertility of the AIS pedigree.

Androgen-Insensitivity Syndrome↗
PubMed1982

[Advantages and risks of hormonal contraception].

Among modern contraceptive methods hormonal contraceptive agents, due to their reliability, are preferred. Nevertheless, it has to be considered that these steroidal hormones and their metabolites do not only possess an ovulation inhibitory effect, but that they also influence other systems, such as carbohydrate and lipid metabolism, blood clotting, fluid balance, plasma proteins as well as the entire hormonal system. These multiple side effects have positive and negative influences. By reducing the doses of estrogens and progestagens occurrence of unpleasant adverse reactions has been decreased. Some years ago, the estrogen content of oral contraceptive preparations was considered to be noxious while a favourable effect was attributed to the progestagen content. The results of biochemical studies yielded a better understanding of the effect of steroidal hormones on lipid metabolism. Fertility problems occurring after discontinuation of oral contraceptive treatment are mainly observed in women who, prior to use of oral contraceptive agents have already been suffering from functional cycle disturbances. Ovulation inhibitory preparations may also be given to adolescent girls with immature cycles. As the juvenile endocrine system is adaptable, after cessation of the ovulation inhibitory effect, the cycle returns to pretreatment patterns. It may now even be possible to administer hormonal contraceptive agents to treat endocrine disturbances.

Adult↗