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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Testicular capillary blood flow (TCBF) was measured by the radioactive inert gas clearance technique throughout the reproductive life of young adult foxes and was related to the spermatogenic and androgenic activities of the testis. Mean (+/-S.E.M.) blood flow (ml min-1 g-1) was maximal in January in adults during the mating period (0-65 +/- 0-03), and in pubertal animals (0-62 +/- 0-04). At this time spermatozoa were observed in the testes of all animals, but testicular weight and circulating testosterone levels were lower in the pubescent foxes than in the adults. TCBF was minimal during immaturity (0-29 +/- 0-03) and during the resting period of the adult (0-12 +/- 0-01). These values were associated with a low testosterone level and with the multiplication of gonocytes in the young or with the seasonal very low spermatogenic activity in the adult. During the prepubertal period, TCBF slowly increased and was accompanied by testicular growth. In the adult, in September, TCBF rapidly increased without changes of testicular size and then slowly increased as the testes enlarged. High plasma testosterone concentrations occurred later. During the period of testicular regression, TCBF, testicular size, spermatogenic and androgenic activities decreased together.
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PMID:Relationship between testicular blood flow, testosterone secretion and spermatogenic activity in young and adult wild red foxes (Vulpes vulpes). 91 74

In this study we have selected a group of patients affected by a more or less severe condition of varicocele. After the evaluation of spermatogenesis and sperm function by electron microscopy we have demonstrated that the sperm malformations are mostly due to immaturity. Subsequently we have observed low FSH levels in the blood, concomitant with inhibin high contents, and we have studied Sertoli cells at submicroscopical level. In conclusion we suggest the following mode of action of varicocele in endocrinologically and spermatologically altered patients: varicocele----Sertoli cells----increased inhibin----hypophysis----decreased FSH----decreased testosterone----aberrant spermatogenesis----immature spermatozoa. The research will continue.
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PMID:Studies on varicocele. 1. Submicroscopical and endocrinological features. 176 92

Ejaculated human spermatozoa were studied to assess their nuclear maturity. After SDS or SDS-EDTA treatment, asthenozoospermic semen had a lower resistance to decondensation than normozoospermic semen and contained more stained immature nuclei after aniline blue staining. It showed a higher uptake of ethidium bromide, specific for DNA. There was no difference in the binding of 14C iodoacetamide in the two groups. Therefore, asthenozoospermic semen could be characterized by its relative nuclear immaturity.
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PMID:Human spermatozoal nuclear maturity in normozoospermia and asthenozoospermia. 246 2

Human sperm immaturity was tested by nuclear chromatin decondensation (NCD) in 1% sodium dodecylsulphate (SDS) of spermatozoa used in 74 consecutive IVF treatments. NCD was significantly higher in the presence of 2 mmol/l dithiothreitol (DTT) and after washing sperm from semen with 6 mmol/l ethylenediaminetetraacetic acid (EDTA). NCD was significantly less in insemination suspensions prepared by the swim-up technique than in the original semen. NCD with DTT was inversely correlated with sperm motility and motility index but there were no significant relationships between NCD and other semen analysis variables. There was no significant correlation between any NCD test and the proportion of oocytes fertilised in vitro. The only factors being significantly correlated with the fertilisation rate were proportion of sperm with normal morphology (Kendall correlation, tau = 0.36, P less than 0.001) and sperm concentration (tau = 0.14, P less than 0.05). Logistic regression analysis of fertilisation rates showed that only percentage normal sperm morphology was significant. It is concluded that NCD does not provide additional useful clinical information about sperm fertilising ability in vitro.
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PMID:Spermatozoal nuclear chromatin decondensation in vitro: a test for sperm immaturity. Comparison with results of human in vitro fertilisation. 345 Mar 77

We have examined by electron microscopy the non fertilized oocytes and the non divided eggs after assay of in vitro fertilization. We have observed three blocking points; 1) absence of fusion of the gametes, either because of oocyte immaturity or over-maturity, either because of spermatozoa phagocytosis by follicle cells transformed in phagocytic cells, in presence of intra or extra-cellular bacteria; 2) fusion of the gametes but absence of spermatic nucleus decondensation; 3) fusion of the gametes and pronuclei formation but absence of amphimixy. Two causes are evident: failure of oocyte maturation in vivo or in vitro, and bacterial contamination problems after female or male infra-clinical infections.
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PMID:[Failures at in vitro fertilization: electron microscopic studies of unfertilized oocytes and undivided ova]. 668 7

Defects of the DNA/protein complex (nuclear immaturity) in chromatin of human spermatozoa with normal and abnormal head morphology in teratozoospermal semen samples (group B) were studied and the findings correlated with normozoospermal samples (group A). Differences were observed in the pattern of thermal DNA stability. Denaturation of native DNA (double strand) from normal and abnormal cells in both groups increased significantly with the time of incubation, compared with their respective controls (p < 0.01). The percentage of denaturation was higher for normal group B sperm (p < 0.05). Differences between groups A and B spermatozoa were detected using cationic dyes, and the DNA/protein complex stability was evaluated by the resistance of sperm samples to acid denaturation; poor chromatin stability was evident in group B. It is suggested that normal and abnormal gametes from group B semen have less stable chromatin (greater nuclear immaturity) than those from group A. This factor may be relevant in assessing the fertilizing capacity of human teratozoospermal samples both in vivo and in vitro.
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PMID:Evaluation of DNA/protein status and nuclear maturity of human sperm. 804 61

A total of 293 oocytes that failed to develop pronuclei after insemination in vitro with apparently normal, fertile spermatozoa were obtained from 87 women undergoing therapeutic in-vitro fertilization. The oocytes were investigated cytogenetically to determine the incidence of immaturity and chromosomal abnormalities. Cytogenetic examination was possible in 81% of the preparations, in which immaturity and chromosomal abnormalities were present in 29.5 and 58.7% respectively.
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PMID:Immaturity and chromosomal abnormalities in oocytes that fail to develop pronuclei following insemination in vitro. 847 25

Spermatozoa mature during epididymal transit, acquiring the abilities to swim progressively, fertilize oocytes, and produce viable offspring. In this study, we investigate the capacity of spermatozoa retrieved from the midcorpus and distal cauda regions of the epididymis of the cynomolgus monkey to penetrate homologous zona pellucida. Successful in vitro fertilization by ejaculated macaque sperm is dependent upon the addition of caffeine and dbcAMP. Therefore, the effect of these cyclic nucleotide mediators was also examined in this study. Results of sperm motion analysis indicate no difference in baseline values (without stimulators) for any motion parameter. With the addition of caffeine and dbcAMP, curvilinear velocity significantly increased only for the distal cauda sperm (P = 0.05). Amplitude of the lateral head displacement was significantly increased for distal cauda sperm (P < 0.01); although elevated above baseline, the increase observed after activation by corpus sperm was significantly lower than that achieved by cauda sperm (P < 0.05). The addition of caffeine and dbcAMP was an absolute requirement for zona penetration by both midcorpus and distal cauda sperm. With activation, zona penetration was significantly decreased for corpus sperm compared to cauda sperm (P < 0.001). These results suggest that cynomolgus monkey sperm reaching the midcorpus region of the epididymis have not completed all of the maturational changes requisite for successful fertilization; this immaturity is evidenced by decreased sperm motion and by impedance at the level of zona penetration.
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PMID:Effects of caffeine and dbcAMP on zona pellucida penetration by epididymal spermatozoa of cynomolgus monkeys (Macaca fascicularis). 905 45

The effects of follicle stimulating hormone (FSH) treatment on the quality of human spermatozoa were assessed by examining the ultrastructure and the function of infertile human spermatozoa using a previously-defined formula. Using the spermatozoa as an andrological monitor shows that the therapeutic effect of FSH depends on the type of sperm defect. The response to FSH is, in many cases, positive and can be evaluated by examining the state of the ejaculated spermatozoa. From an initial group of 81 patients, 15 were placebo-treated controls, and 19 were non-responders (mainly with microbially infected semen). Out of 47 responders, after therapy nine achieved improved sperm quality which approached the natural fertility threshold. These responders all had spermatozoa affected by immaturity or apoptosis (n = 27). The 20 microbially-infected responders also had immature spermatozoa and never achieved the quality level of natural fertility. Thus, a natural fertility level was only achieved by nine responders out of 27 (three with immature spermatozoa, and six with apoptotic spermatozoa). Using our method of sperm analysis, these patients' spermatozoa were clearly categorized before treatment as either immature or apoptotic. In consequence, the success of the therapy was predictable. The response of individual organelles to therapy was examined. Certain qualities of the acrosome, the chromatin, the mitochondria, and the axoneme appear to be sensitive to FSH. Most of the previous conflicting results reported in the literature may be due to a lack of relevant discrimination between the different defects present in the spermatozoa of the patients, without assessing the likelihood of their response.
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PMID:The effect of follicle stimulating hormone therapy on human sperm structure (Notulae seminologicae 11). 936 14

The use of epididymal spermatozoa in assisted reproduction (ART) permits fertility in men with surgically irremediable obstructive azoospermia. When used for conventional IVF (sperm-oocyte co-culture), epididymal spermatozoa show reduced fertilization and pregnancy rates (compared with ejaculated spermatozoa from men with a range of spermatogenic disorders) as evidence of their functional immaturity. However, when used with intracytoplasmic sperm injection (ICSI) either fresh or frozen-thawed epididymal spermatozoa produce ART success rates similar to those of ejaculated spermatozoa. The clinical place of epididymal sperm retrieval for ICSI has come under review as a result of data showing similarly good outcomes with testicular spermatozoa obtained by needle aspiration. In Australia ICSI using epididymal or testicular spermatozoa is an increasingly favoured option for vasectomy-related infertility and in other types of obstructive azoospermia for a number of reasons including better pregnancy outcomes, the less invasive nature of the procedures and less expense involved; however, this cost-benefit analysis will vary in other health systems.
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PMID:The use of epididymal spermatozoa in assisted reproduction. 1064 87


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