Mammalian fertilization involves the migration of spermatozoa through the female reproductive system.Early embryonic development is a consequence of several steps and signaling pathways being activated,as well as bioc...Mammalian fertilization involves the migration of spermatozoa through the female reproductive system.Early embryonic development is a consequence of several steps and signaling pathways being activated,as well as biochemical and morphological modifications of spermatozoa that enable them to penetrate the membrane of mature oocytes.There are some crucial steps known to clearly explain the process of fertilization,starting with hyperactivation of spermatozoa,mutual recognition,and binding of gametes mediated by receptors located on the surface membranes of both gametes.The final step is followed by oocyte activation,which is primarily triggered via sperm-derived factors,inducing a sharp increase in intracellular calcium levels,eventually leading to polyspermy block.This review integrates current knowledge of the molecular and physiological events governing fertilization,emphasizing how ion regulation and signaling pathways converge to enable sperm function and oocyte activation.Special attention is given to sperm-derived factors such as phospholipase C zeta(PLCζ)and post-acrosomal sheath WW domain-binding protein(PAWP),which play essential roles in triggering calcium release and supporting early embryonic development.展开更多
<abstract>During spermiogenesis, the protamine proteins play an integral role in spermatid chromatin compaction. Recent research has focused on many facets of protamine biology, including protamine gene and prot...<abstract>During spermiogenesis, the protamine proteins play an integral role in spermatid chromatin compaction. Recent research has focused on many facets of protamine biology, including protamine gene and protein structure/ function relationships, mechanisms of protamine expression regulation and involvement of the protamines in male fertility. In this paper, we review our current understanding of the structure and function of the protamine-1 (P1) and protamine-2 (P2) proteins and genes, the expression and regulation of these genes and the relationship between the protamines and male fertility. In addition, we offer a brief outlook on future investigation into protamine proteins.展开更多
The scope of paternal contributions during early embryonic development has long been considered limited. Dramatic changes in chromatin structure throughout spermatogenesis have been thought to leave the sperm void of ...The scope of paternal contributions during early embryonic development has long been considered limited. Dramatic changes in chromatin structure throughout spermatogenesis have been thought to leave the sperm void of complex layers of epigenetic regulation over the DNA blueprint, thus leaving the balance of that regulation to the oocyte. However, recent work in the fields of epigenetics and male factor infertility has placed this long-held, and now controversial dogma, in a new light. Elegant studies investigating chromatin and epigenetic modifications in the developing sperm cell have provided new insights that may establish a more critical role for the paternal epigenome in the developing embryo. DNA methylation, histone tail modifications, targeted histone retention and protamine incorporation into the chromatin have great influence in the developing sperm cell. Perturbations in the establishment and/or maintenance of any of these epigenetic marks have been demonstrated to affect fertility status, ranging in severity from mild to catastrophic. Sperm require this myriad of chromatin structural changes not only to serve a protective role to DNA throughout spermatogenesis and future delivery to the egg, but also, it appears, to contribute to the developmental program of the future embryo. This review will focus on our current understanding of the epigenetics of sperm. We will discuss sperm-specific chromatin modifications that result in genes essential to development being poised for activation early in embryonic development, the disruption of which may result in reduced fecundity.展开更多
Obesity has a negative effect on male reproductive function. It is associated with low testosterone levels and alteration in gonadotropin secretion. Male obesity has been linked to reduced male fertility. Data regardi...Obesity has a negative effect on male reproductive function. It is associated with low testosterone levels and alteration in gonadotropin secretion. Male obesity has been linked to reduced male fertility. Data regarding the relation of obesity to sperm parameters are conflicting in terms of the nature and magnitude of the effect. New areas of interest are emerging that can help explain the variation in study results, such as genetic polymorphism and sleep apnea. Sleep disorders have been linked to altered testosterone production and hypogonadism in men. It was also correlated to erectile dysfunction. The relation of sleep disorders to male fertility and sperm parameters remains to be investigated. Men with hypogonadism and infertility should be screened for sleep apnea. Treatment of obesity and sleep apnea improves testosterone levels and erectile function.展开更多
It has recently been shown that alteration of the methylation pattern of imprinted genes is associated with different types of male infertility. The objective of our study was to investigate the methylation pattern of...It has recently been shown that alteration of the methylation pattern of imprinted genes is associated with different types of male infertility. The objective of our study was to investigate the methylation pattern of selected gene promoters in sperm of patients with abnormal protamine replacement. The promoters of OCT4, SOX2, NANOG, HOXC11, miR-17and CREMwere analyzed using bisulfite sequencing and the percentage of DNA methylation was compared between patients with an abnormal protamine l/protamine 2 （P1/ P2） ratio and normozoospermic controls. No significant quantitative differences were found between groups of patients with either an abnormally high or low P1/P2 ratio compared to normal controls. However, two individual samples from infertile subjects （2/20, 10%） showed an altered methylation pattern for the CREMgene promoter that was not found in control samples. These two samples had a significantly higher （P〈0.05） promoter methylation （5.58 and 4.23%, respectively） compared to the control group （0.46%）. In conclusion, in our pilot study, extreme methylations defects were not seen broadly in severely infertile men. However, two patients exhibited altered methylation of the CREMgene, which may be either causative or a result of abnormal protmaine replacement.展开更多
Vitamin D levels have been linked to various health outcomes including reproductive disorders. The purpose of this study was to explore the association between serum vitamin D level （25-hydroxy-vitamin D, or 250HD） ...Vitamin D levels have been linked to various health outcomes including reproductive disorders. The purpose of this study was to explore the association between serum vitamin D level （25-hydroxy-vitamin D, or 250HD） and semen and hormonal parameters. This is a cross-sectional study that included 170 healthy men recruited for the study of spermatogenesis from the general population. Men completed general and reproductive health questionnaires, and donated blood and semen samples. The main measures were hormonal （total and free testosterone, sex hormone-binding globulin, estradiol, follicle-stimulating hormone and luteinizing hormone） and semen parameters, adjusted （n= 147） for age, body mass index （BMI）, season, alcohol intake and smoking, in relation to categories of vitamin D levels, determined apriori. The mean age of the study population was 29.0±8.5 years and mean BMI was 24.3±3.2 kg m-2. The mean 250HD was 34.1± 15.06 ng m1-1. BMI showed a negative association with 250HD. Sperm concentration, sperm progressive motility, sperm morphology, and total progressively motile sperm count were lower in men with ‘250HD ≥ 50 ng ml-1＇ when compared to men with‘20 ng ml-1 ≤ 250H D〈 50 ng ml-1,. Total sperm count and total progressive motile sperm count were lower in men with ‘250HD〈20 ng ml-1＇ when compared to men with‘20 ng ml-1≤250HD〈50 ng ml-1＇. The adjusted means of various hormonal parameters did not show statistical difference in the different categories of 250HD. In conclusion, serum vitamin D levels at high and low levels can be negatively associated with semen parameters.展开更多
Aim： To assess whether abnormalities exist in the UBE2B gene in a population of infertile human males, and to establish biologic plausibility of any discovered mutations. Methods： We carried out polymerase chain rea...Aim： To assess whether abnormalities exist in the UBE2B gene in a population of infertile human males, and to establish biologic plausibility of any discovered mutations. Methods： We carried out polymerase chain reaction （PCR） amplification and sequence analysis of the 5＇-untranslated region and six exons of the UBE2B gene, including flanking intronic regions, in a group of fertile and infertile men. Following the identification of a putative promoter region that contained single or dual triplet deletions within a 10-CGG repeat island, we evaluated the binding affinity of these identified polymorphisms as compared to the wild-type sequence to transcription factor SP1 using a DNA-protein gel shift assay. Results： There was a novel exonic single nucleotide polymorphism （SNP） noted in exon 4 in 5% of infertile men. In silico 3D modeling of the altered protein showed an innocuous isoleucine for valine substitution. There were no mutations noted within any of the other exons. Three novel intronic SNPs were identified within the fertile group, and seven novel intronic SNPs identified in the infertile group. The DNA-protein gel shift assay noted that both single CGG deletion and double CGG deletion bands had approximately twice the binding affinity compared to the wild-type for SP1. The negative control confirmed no non-specific protein binding. Conclusion- By themselves, a single or double CGG deletion is unlikely to pose biologic significance. However, such deletions in this suspected promoter region are associated with increased binding affinity for SP1, and might represent one of several factors required for alteration of UBE2B gene expression.展开更多
Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a ...Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a specific researcher, is assessed through the use of various metrics. While researchers may be acquainted with such matrices, many do not know how to use them to enhance their careers. In addition to these metrics, a number of other factors should be taken into consideration to objectively evaluate a scientist＇s profile as a researcher and academician. Moreover, each metric has its own limitations that need to be considered when selecting an appropriate metric for evaluation. This paper provides a broad overview of the wide array of metrics currently in use in academia and research. Popular metrics are discussed and defined, including traditional metrics and article-level metrics, some of which are applied to researchers for a greater understanding of a particular concept, including varicocete that is the thematic area of this Special Issue of Asian Journal of Andrology. We recommend the combined use of quantitative and qualitative evaluation using judiciously selected metrics for a more objective assessment of scholarly output and research impact.展开更多
Objective: To determine the prognostic value of sperm DNA fragmentation levels, as measured by the sperm chromatin dispersion (SCD) test, in predicting IVF and ICSI outcome. Design: Double- blind prospective study. Se...Objective: To determine the prognostic value of sperm DNA fragmentation levels, as measured by the sperm chromatin dispersion (SCD) test, in predicting IVF and ICSI outcome. Design: Double- blind prospective study. Setting: University- affiliated private IVF setting. Patient(s): A total of 85 couples undergoing infertility treatment with IVF/ICSI. Intervention( s): Analysis of DNA fragmentation by the SCD test in 170 aliquots obtained from the ejaculate and from the processed semen used for assisted reproductive technologies (ART). Main Outcome Measure(s): Percentage of spermatozoa with fragmented DNA was statistically correlated with embryo quality and reproductive success. Result(s): Fertilization rate was inversely correlated with DNA fragmentation (r =- 0.245 P=.045). Higher DNA fragmentation rate gave an increased proportion of zygotes showing asynchrony between the nucleolar precursor bodies of zygote pronuclei (73.8% vs. 28.8% P < .001). In addition, the slower embryo development and worst morphology on day 6 was correlated with higher sperm DNA fragmentation (47.7% vs. 29.4% P=.044). We also observed a negative correlation between DNA fragmentation and the implantation rate (r =- 0.250 P=.042). However, SCD test values were not statistically different in cycles that resulted in a pregnancy compared with those that did not (33.2 vs. 28.2 and 32.4 vs. 34.7). Conclusion(s): This is the first report that describes a correlation between sperm DNA integrity, asmeasured by the SCD test, and fertilization rate, embryo quality, and implantation rate in IVF/ICSI. The degree of DNA fragmentation was inversely correlatedwith fertilization rate, synchrony of the nucleolar precursor bodies’ pattern in pronuclei, embryo ability to achieve blastocyst stage, and embryo morphological quality. Because SCD test values were correlated with embryo quality and blastocyst rate, the lack of correlation between sperm DNA fragmentation and pregnancy outcome in IVF might be due to embryo selection before transfer. The ability of the SCD test to predict the blastocyst rate after IVF/ICSI warrants further study.展开更多
Sperm are a highly specialized cell type derived to deliver the paternal haploid genome to the oocyte. The epigenetic, or gene regulatory, properties and mechanisms of the sperm assist in preparation of the paternal g...Sperm are a highly specialized cell type derived to deliver the paternal haploid genome to the oocyte. The epigenetic, or gene regulatory, properties and mechanisms of the sperm assist in preparation of the paternal genome to contribute to embryogenesis and the genome of the zygote. Many recent studies have addressed the issue of altered epigenetic processes in the sperm. This review evaluates the current understanding of DNA damage, chromosome aneuploidy, reduced telomere length, malformations of the centrosome, genomic imprinting errors, altered mRNA profiles, and abnormal nuclear packaging in the sperm prior to fertilization and the observed effects on embryogenesis. Attention has also been given to understanding the underlying etiology of sperm with altered epigenetic mechanisms in humans. （Asian J Androl 2006 Mar; 8： 131-142）展开更多
Human sperm chromatin, and the sperm of most mammals, undergoes extensive remodeling during spermiogenesis during which 85%-95% of the histones are removed and replaced with protamines. The replacement of most histone...Human sperm chromatin, and the sperm of most mammals, undergoes extensive remodeling during spermiogenesis during which 85%-95% of the histones are removed and replaced with protamines. The replacement of most histones with protamines facilitates a tighter packaging of the chromatin that is necessary for normal sperm function, and may help protect sperm DNA from damage during transport.展开更多
Proton-pump inhibitors （PPIs） are among the most widely used drugs worldwide. PPI use has recently been linked to adverse changes in semen quality in healthy men; however, the effects of PPI use on semen parameters ...Proton-pump inhibitors （PPIs） are among the most widely used drugs worldwide. PPI use has recently been linked to adverse changes in semen quality in healthy men; however, the effects of PPI use on semen parameters remain largely unknown specifically in cases with male factor infertility. We examined whether PPI use was associated with detrimental effects on semen parameters in a large population of subfertile men. We retrospectively reviewed data from 12 257 subfertile men who had visited our fertility clinic from 2003 to 2013. Patients who reported using any PPIs for 〉3 months before semen sample collection were included; 7698 subfertile men taking no medication served as controls. Data were gathered on patient age, medication use, and conventional semen parameters; patients taking any known spermatotoxic medication were excluded. Linear mixed-effect regression models were used to test the effect of PPI use on semen parameters adjusting for age. A total of 248 patients （258 samples） used PPIs for at least 3 months before semen collection. In regression models, PPI use （either as the only medication or when used in combination with other nonspermatotoxic medications） was not associated with statistically significant changes in semen parameters. To our knowledge, this is the largest study to compare PPI use with semen parameters in subfertile men. Using PPIs was not associated with detrimental effects on semen quality in this retrospective study.展开更多
Objective:To describe the various options available for preserving female and/or male fertility,taking into account both social and medical aspects,and to identify the effects of different natural products on male inf...Objective:To describe the various options available for preserving female and/or male fertility,taking into account both social and medical aspects,and to identify the effects of different natural products on male infertility extracted from plants.Methods:We reviewed the literature and included full-text publications in English provided by international biomedical databases,including Sciences Direct,Google Scholar,OVID,PubMed,and MEDLINE between 2016 and 2023.Search terms,such as fertility preservation,in vitro maturation,cryopreservation,plants for the treatment of male infertility,were taken from Medical Subject Headings(MeSH)and Boolean operators were used to improve sensitivity.Results:112 papers were identified in the initial search,of which 18 were excluded due to duplication.After reviewing titles and abstracts,70 papers were finally included.The main findings of this study are presented under three key themes:gametogenesis,fertility preservation techniques,and plant-based alternatives.Regarding gametogenesis,significant progress has been made in understanding oocyte and sperm maturation,with optimized conditions improving maturation rates and motility.For fertility preservation,techniques such as rescue in vitro maturation and cryopreservation have shown the enhanced outcomes,particularly in maintaining gamete quality.Lastly,plant-based alternatives,including extracts and essential oils,have demonstrated potential in reducing oxidative stress,improving sperm motility,and supporting oocyte development,thus providing a promising complementary approach to conventional methods.Conclusions:Fertility preservation is achieved in a variety of ways,including oocyte and embryo vitrification and sperm cryopreservation,and the use of plant-based treatment of male infertility.展开更多
Failed fertilization and the appearance of immature oocytes are common in IVF practice; rescue intracytoplasmic sperm injection can be used as a therapy. However, this study indicates that embryos created after in vit...Failed fertilization and the appearance of immature oocytes are common in IVF practice; rescue intracytoplasmic sperm injection can be used as a therapy. However, this study indicates that embryos created after in vitro maturation and delayed intracytoplasmic sperm injection contain an increase in aneuploidy (79.7%) over control embryos (60.5%). Therefore, patients should be informed of the possible risk when presented with delayed intracytoplasmic sperm injection.展开更多
文摘Mammalian fertilization involves the migration of spermatozoa through the female reproductive system.Early embryonic development is a consequence of several steps and signaling pathways being activated,as well as biochemical and morphological modifications of spermatozoa that enable them to penetrate the membrane of mature oocytes.There are some crucial steps known to clearly explain the process of fertilization,starting with hyperactivation of spermatozoa,mutual recognition,and binding of gametes mediated by receptors located on the surface membranes of both gametes.The final step is followed by oocyte activation,which is primarily triggered via sperm-derived factors,inducing a sharp increase in intracellular calcium levels,eventually leading to polyspermy block.This review integrates current knowledge of the molecular and physiological events governing fertilization,emphasizing how ion regulation and signaling pathways converge to enable sperm function and oocyte activation.Special attention is given to sperm-derived factors such as phospholipase C zeta(PLCζ)and post-acrosomal sheath WW domain-binding protein(PAWP),which play essential roles in triggering calcium release and supporting early embryonic development.
文摘<abstract>During spermiogenesis, the protamine proteins play an integral role in spermatid chromatin compaction. Recent research has focused on many facets of protamine biology, including protamine gene and protein structure/ function relationships, mechanisms of protamine expression regulation and involvement of the protamines in male fertility. In this paper, we review our current understanding of the structure and function of the protamine-1 (P1) and protamine-2 (P2) proteins and genes, the expression and regulation of these genes and the relationship between the protamines and male fertility. In addition, we offer a brief outlook on future investigation into protamine proteins.
文摘The scope of paternal contributions during early embryonic development has long been considered limited. Dramatic changes in chromatin structure throughout spermatogenesis have been thought to leave the sperm void of complex layers of epigenetic regulation over the DNA blueprint, thus leaving the balance of that regulation to the oocyte. However, recent work in the fields of epigenetics and male factor infertility has placed this long-held, and now controversial dogma, in a new light. Elegant studies investigating chromatin and epigenetic modifications in the developing sperm cell have provided new insights that may establish a more critical role for the paternal epigenome in the developing embryo. DNA methylation, histone tail modifications, targeted histone retention and protamine incorporation into the chromatin have great influence in the developing sperm cell. Perturbations in the establishment and/or maintenance of any of these epigenetic marks have been demonstrated to affect fertility status, ranging in severity from mild to catastrophic. Sperm require this myriad of chromatin structural changes not only to serve a protective role to DNA throughout spermatogenesis and future delivery to the egg, but also, it appears, to contribute to the developmental program of the future embryo. This review will focus on our current understanding of the epigenetics of sperm. We will discuss sperm-specific chromatin modifications that result in genes essential to development being poised for activation early in embryonic development, the disruption of which may result in reduced fecundity.
文摘Obesity has a negative effect on male reproductive function. It is associated with low testosterone levels and alteration in gonadotropin secretion. Male obesity has been linked to reduced male fertility. Data regarding the relation of obesity to sperm parameters are conflicting in terms of the nature and magnitude of the effect. New areas of interest are emerging that can help explain the variation in study results, such as genetic polymorphism and sleep apnea. Sleep disorders have been linked to altered testosterone production and hypogonadism in men. It was also correlated to erectile dysfunction. The relation of sleep disorders to male fertility and sperm parameters remains to be investigated. Men with hypogonadism and infertility should be screened for sleep apnea. Treatment of obesity and sleep apnea improves testosterone levels and erectile function.
文摘It has recently been shown that alteration of the methylation pattern of imprinted genes is associated with different types of male infertility. The objective of our study was to investigate the methylation pattern of selected gene promoters in sperm of patients with abnormal protamine replacement. The promoters of OCT4, SOX2, NANOG, HOXC11, miR-17and CREMwere analyzed using bisulfite sequencing and the percentage of DNA methylation was compared between patients with an abnormal protamine l/protamine 2 （P1/ P2） ratio and normozoospermic controls. No significant quantitative differences were found between groups of patients with either an abnormally high or low P1/P2 ratio compared to normal controls. However, two individual samples from infertile subjects （2/20, 10%） showed an altered methylation pattern for the CREMgene promoter that was not found in control samples. These two samples had a significantly higher （P〈0.05） promoter methylation （5.58 and 4.23%, respectively） compared to the control group （0.46%）. In conclusion, in our pilot study, extreme methylations defects were not seen broadly in severely infertile men. However, two patients exhibited altered methylation of the CREMgene, which may be either causative or a result of abnormal protmaine replacement.
文摘Vitamin D levels have been linked to various health outcomes including reproductive disorders. The purpose of this study was to explore the association between serum vitamin D level （25-hydroxy-vitamin D, or 250HD） and semen and hormonal parameters. This is a cross-sectional study that included 170 healthy men recruited for the study of spermatogenesis from the general population. Men completed general and reproductive health questionnaires, and donated blood and semen samples. The main measures were hormonal （total and free testosterone, sex hormone-binding globulin, estradiol, follicle-stimulating hormone and luteinizing hormone） and semen parameters, adjusted （n= 147） for age, body mass index （BMI）, season, alcohol intake and smoking, in relation to categories of vitamin D levels, determined apriori. The mean age of the study population was 29.0±8.5 years and mean BMI was 24.3±3.2 kg m-2. The mean 250HD was 34.1± 15.06 ng m1-1. BMI showed a negative association with 250HD. Sperm concentration, sperm progressive motility, sperm morphology, and total progressively motile sperm count were lower in men with ‘250HD ≥ 50 ng ml-1＇ when compared to men with‘20 ng ml-1 ≤ 250H D〈 50 ng ml-1,. Total sperm count and total progressive motile sperm count were lower in men with ‘250HD〈20 ng ml-1＇ when compared to men with‘20 ng ml-1≤250HD〈50 ng ml-1＇. The adjusted means of various hormonal parameters did not show statistical difference in the different categories of 250HD. In conclusion, serum vitamin D levels at high and low levels can be negatively associated with semen parameters.
文摘Aim： To assess whether abnormalities exist in the UBE2B gene in a population of infertile human males, and to establish biologic plausibility of any discovered mutations. Methods： We carried out polymerase chain reaction （PCR） amplification and sequence analysis of the 5＇-untranslated region and six exons of the UBE2B gene, including flanking intronic regions, in a group of fertile and infertile men. Following the identification of a putative promoter region that contained single or dual triplet deletions within a 10-CGG repeat island, we evaluated the binding affinity of these identified polymorphisms as compared to the wild-type sequence to transcription factor SP1 using a DNA-protein gel shift assay. Results： There was a novel exonic single nucleotide polymorphism （SNP） noted in exon 4 in 5% of infertile men. In silico 3D modeling of the altered protein showed an innocuous isoleucine for valine substitution. There were no mutations noted within any of the other exons. Three novel intronic SNPs were identified within the fertile group, and seven novel intronic SNPs identified in the infertile group. The DNA-protein gel shift assay noted that both single CGG deletion and double CGG deletion bands had approximately twice the binding affinity compared to the wild-type for SP1. The negative control confirmed no non-specific protein binding. Conclusion- By themselves, a single or double CGG deletion is unlikely to pose biologic significance. However, such deletions in this suspected promoter region are associated with increased binding affinity for SP1, and might represent one of several factors required for alteration of UBE2B gene expression.
文摘Traditionally, the success of a researcher is assessed by the number of publications he or she publishes in peer-reviewed, indexed, high impact journals. This essential yardstick, often referred to as the impact of a specific researcher, is assessed through the use of various metrics. While researchers may be acquainted with such matrices, many do not know how to use them to enhance their careers. In addition to these metrics, a number of other factors should be taken into consideration to objectively evaluate a scientist＇s profile as a researcher and academician. Moreover, each metric has its own limitations that need to be considered when selecting an appropriate metric for evaluation. This paper provides a broad overview of the wide array of metrics currently in use in academia and research. Popular metrics are discussed and defined, including traditional metrics and article-level metrics, some of which are applied to researchers for a greater understanding of a particular concept, including varicocete that is the thematic area of this Special Issue of Asian Journal of Andrology. We recommend the combined use of quantitative and qualitative evaluation using judiciously selected metrics for a more objective assessment of scholarly output and research impact.
文摘Objective: To determine the prognostic value of sperm DNA fragmentation levels, as measured by the sperm chromatin dispersion (SCD) test, in predicting IVF and ICSI outcome. Design: Double- blind prospective study. Setting: University- affiliated private IVF setting. Patient(s): A total of 85 couples undergoing infertility treatment with IVF/ICSI. Intervention( s): Analysis of DNA fragmentation by the SCD test in 170 aliquots obtained from the ejaculate and from the processed semen used for assisted reproductive technologies (ART). Main Outcome Measure(s): Percentage of spermatozoa with fragmented DNA was statistically correlated with embryo quality and reproductive success. Result(s): Fertilization rate was inversely correlated with DNA fragmentation (r =- 0.245 P=.045). Higher DNA fragmentation rate gave an increased proportion of zygotes showing asynchrony between the nucleolar precursor bodies of zygote pronuclei (73.8% vs. 28.8% P < .001). In addition, the slower embryo development and worst morphology on day 6 was correlated with higher sperm DNA fragmentation (47.7% vs. 29.4% P=.044). We also observed a negative correlation between DNA fragmentation and the implantation rate (r =- 0.250 P=.042). However, SCD test values were not statistically different in cycles that resulted in a pregnancy compared with those that did not (33.2 vs. 28.2 and 32.4 vs. 34.7). Conclusion(s): This is the first report that describes a correlation between sperm DNA integrity, asmeasured by the SCD test, and fertilization rate, embryo quality, and implantation rate in IVF/ICSI. The degree of DNA fragmentation was inversely correlatedwith fertilization rate, synchrony of the nucleolar precursor bodies’ pattern in pronuclei, embryo ability to achieve blastocyst stage, and embryo morphological quality. Because SCD test values were correlated with embryo quality and blastocyst rate, the lack of correlation between sperm DNA fragmentation and pregnancy outcome in IVF might be due to embryo selection before transfer. The ability of the SCD test to predict the blastocyst rate after IVF/ICSI warrants further study.
文摘Sperm are a highly specialized cell type derived to deliver the paternal haploid genome to the oocyte. The epigenetic, or gene regulatory, properties and mechanisms of the sperm assist in preparation of the paternal genome to contribute to embryogenesis and the genome of the zygote. Many recent studies have addressed the issue of altered epigenetic processes in the sperm. This review evaluates the current understanding of DNA damage, chromosome aneuploidy, reduced telomere length, malformations of the centrosome, genomic imprinting errors, altered mRNA profiles, and abnormal nuclear packaging in the sperm prior to fertilization and the observed effects on embryogenesis. Attention has also been given to understanding the underlying etiology of sperm with altered epigenetic mechanisms in humans. （Asian J Androl 2006 Mar; 8： 131-142）
文摘Human sperm chromatin, and the sperm of most mammals, undergoes extensive remodeling during spermiogenesis during which 85%-95% of the histones are removed and replaced with protamines. The replacement of most histones with protamines facilitates a tighter packaging of the chromatin that is necessary for normal sperm function, and may help protect sperm DNA from damage during transport.
文摘Proton-pump inhibitors （PPIs） are among the most widely used drugs worldwide. PPI use has recently been linked to adverse changes in semen quality in healthy men; however, the effects of PPI use on semen parameters remain largely unknown specifically in cases with male factor infertility. We examined whether PPI use was associated with detrimental effects on semen parameters in a large population of subfertile men. We retrospectively reviewed data from 12 257 subfertile men who had visited our fertility clinic from 2003 to 2013. Patients who reported using any PPIs for 〉3 months before semen sample collection were included; 7698 subfertile men taking no medication served as controls. Data were gathered on patient age, medication use, and conventional semen parameters; patients taking any known spermatotoxic medication were excluded. Linear mixed-effect regression models were used to test the effect of PPI use on semen parameters adjusting for age. A total of 248 patients （258 samples） used PPIs for at least 3 months before semen collection. In regression models, PPI use （either as the only medication or when used in combination with other nonspermatotoxic medications） was not associated with statistically significant changes in semen parameters. To our knowledge, this is the largest study to compare PPI use with semen parameters in subfertile men. Using PPIs was not associated with detrimental effects on semen quality in this retrospective study.
文摘Objective:To describe the various options available for preserving female and/or male fertility,taking into account both social and medical aspects,and to identify the effects of different natural products on male infertility extracted from plants.Methods:We reviewed the literature and included full-text publications in English provided by international biomedical databases,including Sciences Direct,Google Scholar,OVID,PubMed,and MEDLINE between 2016 and 2023.Search terms,such as fertility preservation,in vitro maturation,cryopreservation,plants for the treatment of male infertility,were taken from Medical Subject Headings(MeSH)and Boolean operators were used to improve sensitivity.Results:112 papers were identified in the initial search,of which 18 were excluded due to duplication.After reviewing titles and abstracts,70 papers were finally included.The main findings of this study are presented under three key themes:gametogenesis,fertility preservation techniques,and plant-based alternatives.Regarding gametogenesis,significant progress has been made in understanding oocyte and sperm maturation,with optimized conditions improving maturation rates and motility.For fertility preservation,techniques such as rescue in vitro maturation and cryopreservation have shown the enhanced outcomes,particularly in maintaining gamete quality.Lastly,plant-based alternatives,including extracts and essential oils,have demonstrated potential in reducing oxidative stress,improving sperm motility,and supporting oocyte development,thus providing a promising complementary approach to conventional methods.Conclusions:Fertility preservation is achieved in a variety of ways,including oocyte and embryo vitrification and sperm cryopreservation,and the use of plant-based treatment of male infertility.
文摘Failed fertilization and the appearance of immature oocytes are common in IVF practice; rescue intracytoplasmic sperm injection can be used as a therapy. However, this study indicates that embryos created after in vitro maturation and delayed intracytoplasmic sperm injection contain an increase in aneuploidy (79.7%) over control embryos (60.5%). Therefore, patients should be informed of the possible risk when presented with delayed intracytoplasmic sperm injection.
