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Results for “Reproductive parameters”

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At least 1,495 records · Page 83Linked to original sources

PubMed2003

[Evaluation of radiation damage to the sperm DNA of radar operators].

OBJECTIVE: To evaluate the inflicted by radar electromagnetic radiation to the sperm DNA of radar operators. METHODS: Sperm concentration, viability, motility, sperm abnormality were determined by routine sperm analysis and sperm chromatin structure assay (SCSA) in the highly exposed group(n = 88), lowly exposed group(n = 143) and control group(n = 39). RESULTS: Sperm motility, viability of the highly exposed group reduced compared with that of the lowly exposed group and control group, while sperm abnormality increased. The COMP alpha reduction of the highly exposed group indicated that the highly exposed group had a medium fertility potential. The multifactor variable analysis showed that daily working time was a dangerous factor in sperm abnormality and abstinence time was a dangerous factor in the parameter of SCSA. CONCLUSIONS: Radar radiation inflicts damage to male reproduction system and it is important to take protective measures.

Adolescent↗

PubMed2004

[Effects of six host plants on the development and fecundity of Cicadulina bipunctella].

The study on the development, survivorship and fecundity of Cicadulina bipunctella reared on corn, wheat, sorghum, rice, millet, barley and Leptochloa panacea showed that the insect could develop and reproduce on all test host plants except for Leptochloa panacea. The development duration of C. bipunctella at its immature stages reared on sorghum was the shortest (24.1 d), then on corn (24.2 d), and the longest on wheat (25.5 d). The survival rate (40.8%), longevity (12.2 d) and oviposition per female (12.3 eggs) of female adults reared on rice were lower than those reared on the other five host plants. Based on the life-table parameters, the most suitable host plants for the development and reproduction of C. bipunctella were millet and corn, followed by sorghum, barley, wheat and rice.

Animals↗

PubMedDate not supplied

[A pneumatic drive for the artificial heart apparatus with improved energy characteristics].

It has been shown in the present work that if gas compressibility is to be regarded as a reversible effect of energy accumulation, it can be used both for enhancing the pneumatic drive efficiency and maintenance of the goal-oriented self-control of the artificial heart apparatus on the whole. Such self-control provides an opportunity of realizing not only the pump functional characteristics of the apparatus, similar to the analogous parameters of the natural heart, but also of maintaining the reproduction of the other regulatory properties based on the interaction between the left and the right ventricles.

Heart, Artificial↗

PubMedDate not supplied

Significance of the occurrence and distribution of glycogen in cervical cells exfoliated under different physiologic and pathologic conditions.

The occurrence and distribution of glycogen was investigated in cervical cells exfoliated under different physiologic and pathologic conditions using cytochemical parameters. The conditions studied included the menstrual cycle, menopause, the reproductive cycle and neoplastic lesions of the cervix in both premenopausal and postmenopausal and postmenopausal situations. The results obtained on the localization of this carbohydrate substance offer interesting information with respect to the absence and presence of glycogen in various degrees in different cell types. The presence of glycogen seems to be linked with cellular maturation; it disappears with the loss of differentiation during neoplasia. The high glycogen content during the menstrual cycle and reproductive cycle and its absence in postmenopause indicates a specific hormonal influence. The discrepancies noted in glycogen distribution in the same or different exfoliated cells obtained from different biologic states assume significance in light of various factors governing the synthesis and utilization of this polymer.

Adult↗

PubMed1981

Endocrine function in the Klüver-Bucy syndrome: studies in adult female rhesus monkeys.

Although the behavioral abnormalities of the Klüver-Bucy syndrome are well known, an investigation of the endocrine parameters had not been undertaken previously. The authors report normal reproductive cyclicity (including preserved feedback mechanisms) and growth hormone and cortisol secretion patterns in female rhesus monkeys with the syndrome. It is concluded that the abnormal behavior seen in the Klüver-Bucy syndrome is not associated with abnormalities of the reproductive mechanisms.

Animals↗

PubMed1995

Validation procedures for the Hamilton Thorne Integrated Visual Optical System sperm and cell analyzer.

The Hamilton Thorne Integrated Visual Optical System (IVOS) analyzer is a combined internal optical and computer system widely applied to laboratory animals, such as rat, rabbit, and canine, sperm in reproductive toxicology. It measures sperm motility, progressive motility, velocity, motion parameters, and concentration. The system is specially designed to facilitate on-site validation. Digital encoding allows image storage with absolute replay fidelity for later reexamination, enabling on-site validation complying with Good Laboratory Practices. A NIST-certified scale provides the length standard on which validation is based. Sperm typically move in wavy tracks, which must be characterized and validated. Playback of exact sperm tracks allows visual validation of sperm head position, given as Cartesian coordinates, and visual determination of motility from the playback screen. A cursor checks coordinate values, and manual confirmation of sperm motion parameters may be performed directly from the validated coordinates. Agreement to within 0.2% is obtained between manual and IVOS computation. Concentration is determined using a specific DNA stain that enables discrimination between sperm and somatic cell nuclei. The IVOS concentration of sperm nuclei in homogenized rat testis and cauda epididymis has been determined to be within 5% of manual hemacytometer counts of the same homogenate.

Humans↗

PubMed2003

Growth or reproduction? Resource allocation by female frogs Rana temporaria.

The decision how to allocate marginal resources to reproduction and growth can have important effects on associated life-history parameters as well as on population dynamics. In addition to showing variation among individuals in a population, such allocation rules may be either condition-dependent or fixed in different individuals. While many studies on anuran amphibians have focused on egg numbers and egg sizes in females of different sizes, virtually no data exist on the relative allocation of marginal resources to growth versus reproduction. In the laboratory, we therefore offered female common frogs ( Rana temporaria) low versus high food rations for a full reproductive cycle, and monitored their growth and later reproductive investment (egg number and egg size the following breeding season). Feeding rates had an effect both on female growth and on egg number and size. There was no trade-off found between the two forms of investment. A flexible allocation rule could not be supported as there was no significant effect of feeding rate on the relative allocation of resources to growth versus reproduction.

Adaptation, Physiological↗

PubMed2001

The effect of single-dose oxytocin application on time to ejaculation and seminal parameters in men.

PURPOSE: To report the effect of a single dose of oxytocin on ejaculation time and seminal parameters. METHODS: The prospective randomized clinical study was performed at a private assisted reproduction technology center and included 103 consecutive healthy men (semen donors or husbands of IVF patients). Oxytocin (16 IU) were administered intranasally to 49 subjects, randomly assigned to the study group just before masturbation to ejaculation. The time needed for ejaculation as well as the semen parameters was recorded according to the WHO standards, and compared to the control group of 54 subjects with no prior oxytocin treatment. RESULTS: No significant difference was noted between the two groups concerning ejaculation time and semen parameters. CONCLUSIONS: Although the administration of oxytocin stimulates sexual behavior and performance in mammalian species, our data indicate that oxytocin has no detectable effect on ejaculation time and seminal parameters after intranasal application in normal, healthy men.

Administration, Intranasal↗

PubMed1975

Natural selection and the evolution of reproductive effort.

Reproductive effort is defined as that proportion of the total energy budget of an organism that is devoted to reproductive processes. Reproductive effort at a given age within a species will be selected to maximize reproductive value at that age. Reproductive effort is not directly affected by changes in juvenile survivorship, nor necessarily reduced by an increase in adult survivorship. Selection for high levels of reproductive effort should occur when extrinsic adult mortality is high, in environments with constant juvenile survivorship, and in good years for juvenile survivorship in a variable environment, provided that the quality of the year is predictable by adults. Data necessary to measure reproductive effort and to understand how selection results in different levels of effort between individuals and species are discussed. We make several predictions about the effect of increased resource availability on reproductive effort. The empirical bases for testing these predictions are presently inadequate, and we consider data on energy budgets of organisms in nature to be essential for such test. We also conclude that variance in life table parameters must be known in detail to understand the selective bases of levels of reproductive effort.

Age Factors↗

PubMed2005

Immature oocyte in-vitro maturation: clinical aspects.

The development of immature oocyte collection techniques for in-vitro maturation (IVM), combined with novel culture techniques, opens new possibilities for assisted reproductive technology. Optimization of clinical management of IVM cycles will enhance pregnancy outcome, so that IVM might become an effective alternative assisted reproduction treatment for infertile patients irrespective of the cause of infertility. Parameters such as age and baseline antral follicular count are predictive of outcome and should be used as selection criteria for IVM treatment. Women with polycystic ovary disease and normo-ovulatory patients at risk of developing ovarian hyperstimulation syndrome might benefit from earlier retrieval of oocytes followed by IVM and embryo transfer. HCG priming before oocyte retrieval seems beneficial in terms of oocyte yield and maturational competence, and may increase the harvest of mature oocytes and lead to better endometrial synchronization with the developing embryo. The timing of aspiration may be crucial in IVM and selection criteria for follicle size at aspiration need defining prospectively for infertility type. Finer calibre aspiration needles and low aspiration pressure yield more oocytes. A combination of natural cycle IVF with IVM is a promising, mild and inexpensive assisted reproduction treatment, widely accessible the infertile population.

Animals↗

PubMed1999

[Diagnosis of zinc deficiency].

Though far more common, particularly in elderly people, than was previously assumed, marginal zinc deficiency does not lead to the classical manifestations of zinc deficiency and is therefore difficult to diagnose. There is therefore a need for sensitive parameters that can reliably demonstrate even marginal zinc deficiency, as suboptimal zinc status can seriously impair human health, performance, reproductive functions, and mental and physical development. The most important criteria for the diagnosis of zinc deficiency are critically discussed. The laboratory parameters currently considered to be the most useful indicators of marginal zinc deficiency are zinc-binding capacity and serum/plasma alkaline phosphatase activity before and after zinc supplementation (zinc tolerance test!). In order to obtain a reliable assessment of a patients zinc status, a number of different diagnostic parameters should always be measured.

Aged↗

PubMed1997

Effect of dietary aminoguanidine on tissue pentosidine and reproductive performance in broiler breeder hens.

Factors influencing the age-related decline in production parameters of broiler breeder hens are poorly understood. Elevated blood glucose concentrations measured in broiler breeder hens may contribute to this decline. The nonenzymatic attachment of glucose to proteins generates glycoxidation crosslinks in tissue proteins, which can ultimately impair their function. One such glycoxidation crosslink, pentosidine, has been used as a biomarker for aging studies because of its accumulation on the structural protein collagen. The objectives of these studies were to determine whether pentosidine accumulates with age in hens and whether the crosslinking inhibitor, aminoguanidine (AG), could retard this accumulation. An additional objective was to determine whether AG had any effect on production performance. In the first study, broiler breeder hens (n = 318) were randomly assigned to two groups: control and supplemented (400 ppm AG). Pentosidine was measured in the skin of the birds at 20 and 67 wk of age. Egg production was measured daily. In a second study, broiler breeder hens (n = 60) were reared as previously described. Pentosidine was measured in the skin of the birds at 20 and 68 wk of age. Results showed that pentosidine was present in the skin of the hens, and that concentrations increased with age (P < 0.001). Although pentosidine was reduced (P < 0.001) in AG-supplemented birds, production performance was not affected. In conclusion, AG retarded the rate of accumulation of pentosidine during lay in broiler breeder hens, but the reduction in pentosidine did not significantly affect production performance.

Aging↗

PubMed2006

FSH receptor gene polymorphisms in fertile and infertile Italian men.

In women, single nucleotide polymorphisms (SNP) of the FSH receptor (FSHR) gene influence FSH concentrations and the sensitivity of the FSHR to FSH in vivo. In contrast, the significance of FSHR R gene SNP in the male is poorly understood. To this aim, the possible role of three FSHR SNP was evaluated in male infertility. SNP in exon 10 (codon 307 and 680) and in the core promoter region (at position -29) of the FSHR gene were analysed by polymerase chain reaction-restriction fragment length polymorphism technique in 150 men representative of the general population, 107 proven fathers, 92 normozoospermic controls, and 215 infertile patients classified according to sperm parameters (38 azoospermia, 53 severe oligozoospermia, 48 moderate oligozoospermia, and 76 slight oligozoospermia). Reproductive hormones were measured in infertile males and normozoospermic controls. No significant difference was found in allelic variants frequency and genotype distribution between each category of subjects when analysing the FSHR exon 10 SNP alone and in combination with the SNP at position -29. Serum FSH concentrations and other andrological parameters did not differ between subjects with different genotype within each group. The data showed that in the Italian population, FSHR genotypes have no influence on FSH concentrations both in normal and infertile males and do not associate with spermatogenetic impairment.

Alleles↗

PubMed2005

Is there a possible correlation between chromosomal variants and spermatogenesis?

AIM: Heterochromatin polymorphism is considered a variant of a normal karyotype but is more frequent in infertile men. The aim of this study was to evaluate the correlation between heterochromatic variants and male infertility and to discuss the possible mechanisms of how heterochromatic polymorphism might affect spermatogenesis. METHODS: Cytogenetic analysis was undertaken in 210 infertile males who had been taken into assisted reproductive techniques and in 183 men with proven fertility. Additionally, C-banding was performed in men with heterochromatin polymorphism. Sperm fluorescence in situ hybridization (FISH) was applied in 54 men with normal karyotype presenting either normal or abnormal sperm parameters as well as in 8 men with heterochromatin polymorphism. The outcomes of assisted reproductive techniques were compared between infertile men with normal karyotype and men with heterochromatin polymorphism. RESULTS: The incidence of heterochromatin polymorphism was higher in infertile men. The most frequent chromosome involved in heterochromatin polymorphism was chromosome 9. Sperm FISH analysis revealed an increased rate of aneuploidy in men with heterochromatin polymorphism. Laboratory and clinical outcomes in assisted reproductive techniques were compromised in men with heterochromatin polymorphism. CONCLUSIONS: An increased rate of heterochromatin polymorphism in infertile males seems to be more than an incidental finding, and must not be considered as a normal variant. Polymorphic heterochromatin may have deleterious effects on the genetic constitution of spermatozoa. More attention must be directed to infertile men with heterochromatin polymorphism.

Adult↗

PubMed1997

Endometriosis-associated pelvic pain: evidence for an association between the stage of disease and a history of chronic pelvic pain.

OBJECTIVE: To track the severity and location of pelvic pain associated with endometriosis throughout the reproductive-age years and to evaluate the association between these pain parameters and the stage of disease. DESIGN: Historical prospective study. SETTING: Tertiary care center. PATIENT(S): Forty-eight women with endoscopically staged endometriosis and chronic pelvic pain who had undergone medical and/or conservative surgical therapy. INTERVENTION(S): Each participant was administered a questionnaire that included a determination of the severity and location of her pain. MAIN OUTCOME MEASURE(S): The stage of disease, the area of the pelvis that contained the bulk of disease, the severity of pain, and the location of the most severe pain were recorded. RESULT(S): The mean duration from the initial diagnosis until follow-up was 15.7 +/- 3.1 years, Twenty-one (43.8%) subjects denied any symptoms of pain on follow-up evaluation. Of the 27 patients with persistent pain, 21 (78%) identified the location of their most severe pain as being the same as at initial diagnosis. The stage of disease at initial diagnosis was significantly associated with a higher degree of pain at follow-up. CONCLUSION(S): These data suggest that endometriosis-associated chronic pelvic pain commonly persists throughout the reproductive years and that endometriosis stage is directly related to the persistence of pelvic pain.

Adult↗

PubMed1998

Association of semen quality and occupational factors: comparison of case-control analysis and analysis of continuous variables.

OBJECTIVE: To compare two statistical approaches, case-control and analysis of continuous parameters of semen, in examining the relationship between occupational exposures and male reproductive function. DESIGN: Case-control study. SETTING: Males providing semen samples at a university infertility clinic. PATIENT(S): Nonvasectomized males who provided at least one semen sample at an infertility clinic. MAIN OUTCOME MEASURE(S): Standard clinical semen analysis. RESULT(S): Analyses using a dichotomous dependent variable did not uncover significant associations between any occupational factor and infertility case status. However, linear models incorporating continuous variables identified a number of occupational factors that were associated with specific parameters of semen. A reduction in percentage of progressive sperm and an increase in percentage of coiled tail sperm defects in welders, compared with unexposed subjects, were found. Significant dose-response relationships between level of perceived job stress and percentage of progressive sperm, total motile count, morphology, abnormal heads, and coiled tail defects were found. CONCLUSION(S): The findings suggest that subtle changes in semen variables, possibly associated with workplace exposure, may be detected only with parametric analyses of continuous variables of semen.

Adult↗

PubMed2003

Seasonal timing of sperm production in roe deer: interrelationship among changes in ejaculate parameters, morphology and function of testis and accessory glands.

Roe deer are seasonal breeders with a short rutting season from mid-July to mid-August. The seasonality of reproductive activity in males is associated with cyclic changes between growth and involution of both testes and the accessory sex glands. This study characterizes morphological and functional parameters of these organs prior to, during and after breeding season in live adult roe deer bucks. Size and morphology of the reproductive tract was monitored monthly by transcutaneous (testes, epididymis) and transrectal (accessory glands) ultrasonography. Semen was collected by electroejaculation. Concentration, motility and morphological integrity of spermatozoa as well as the content of proteins and testosterone in semen plasma were evaluated. Proportions of haploid, diploid and tetraploid cells were estimated by flow cytometry in testicular tissue biopsies. Serum testosterone was measured by enzyme immunoassay. Most parts of the male reproductive tract showed distinct circannual changes in size and texture. These changes were most pronounced in the testes, seminal vesicles, and prostate. All reproductive organs were highly developed during the rut only. The volume of ejaculates, total sperm number and percentages of motile and intact spermatozoa also showed a maximum during this period and corresponded with high proportions of haploid cells in the testis. The highest percentages of tetraploid cells were found in the prerutting period. The production of motile and intact spermatozoa correlated with both the protein content of semen plasma and the concentration of testosterone in semen plasma and blood serum. These results suggest the importance of combined actions of the testes and accessory sex glands and the crucial role of testosterone in facilitating the optimal timing of intensified semen production to ensure sufficient numbers of normal spermatozoa in seasonal breeders.

Animals↗

PubMedDate not supplied

Workshop on the qualitative and quantitative comparability of human and animal developmental neurotoxicity, Work Group II report: testing methods in developmental neurotoxicity for use in human risk assessment.

The Work Group addressed the design and content of a basic screening battery for detecting or flagging developmental neurotoxicity. It was agreed that a basic screening battery should be incorporated routinely into any developmental or reproductive toxicity study conducted for risk assessment purposes, and that a "triggered" stand-alone developmental neurotoxicity study, as exemplified by the current EPA proposal, should include greater in-depth evaluation of CNS function and pathology. Time constraints did not permit the group to address the design or content of such a stand-alone study. It was acknowledged unanimously that a basic screening battery may provide more information than simply the detection of neurotoxicity; however, it should not be expected to provide detailed dose-response information nor to identify the precise mechanism of agent action. The Work Group also agreed that a basic screening battery should include evaluation of multiple CNS functions, that observed alterations may be indicative of primary or secondary effects on the nervous system, that the test methods selected may differ based on what is known about the agent, and that the protocol for study conduct can be as important as the methods employed. In light of these assumptions, the Work Group recommended schedules for monitoring offspring development using measures of: 1) physical landmarks, 2) brain weights, 3) neuropathology, 4) functional observations, 5) motor activity, 6) reactivity, and 7) learning and memory. The species tested, sample sizes, treatment parameters, etc., would be determined by the type of developmental or reproductive toxicity study into which the basic screening battery was incorporated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗