Fertility preservation in adult male patients with cancer: a systematic review and meta-analysis

STUDY QUESTION

Does sperm cryopreservation serve as a feasible and effective method for preserving fertility in adult male patients with cancer?

SUMMARY ANSWER

Sperm cryopreservation is an effective fertility preservation method and may benefit patients with cancer.

WHAT IS KNOWN ALREADY

Sperm cryopreservation is the only way to efficiently preserve male fertility. It is an important procedure in ART. Recently, due to remarkable advances in cancer treatment, an increasing number of studies have reported the outcomes of sperm cryopreservation in patients with cancer.

STUDY DESIGN SIZE DURATION

We conducted an extensive literature search for relevant studies published through to 31 December 2021, in the following databases: CENTRAL, CNKI, Cochrane Systematic Reviews, EMBASE, MEDLINE, PUBMED, and Web of Science. The search terms used were '(cryopreservation OR freeze OR freezing OR banking OR cryostorage OR storage) AND (sperm OR semen OR spermatozoon) AND (cancer OR tumor OR malignancy OR neoplasm)'.

PARTICIPANTS/MATERIALS SETTING METHODS

We included all studies that reported offering or attempting to cryopreserve sperm before or during cancer treatment in male patients considered at risk of treatment-related fertility impairment. We evaluated the eligibility of all data in each study. The major exclusion criteria were as follows: non-cancer patients; pediatric and adolescent cancer patients; not reporting the use of cryopreserved sperm; use of fresh semen for ART; not reporting the number of patients with cancer offered sperm cryopreservation or attempting to do so before or during treatment; using an experimental fertility preservation technique such as preservation of testicular tissue or spermatogonial stem cells; duplicate data; abstracts, case report, comments, reviews, or editorials; insufficient data reported. The quality of the included studies was assessed using the Newcastle-Ottawa scale and the Methodological Index for Non-Randomized Studies.

MAIN RESULTS AND THE ROLE OF CHANCE

This meta-analysis included 69 non-randomized studies, with 32 234 patients referred for sperm analysis and 23 178 patients cryopreserving at least one sperm sample. The pooled failed-to-cryopreserve rate was 10% (95% CI, 8-12%), and the sperm disposal and sperm use rates were 23% (95% CI, 16-30%) and 9% (95% CI, 8-10%), respectively. The pregnancy, miscarriage, and delivery rates were 28% (95% CI, 22-33%), 13% (95% CI, 10-17%), and 20% (95% CI, 15-25%), respectively. Subgroup analysis showed higher pregnancy and delivery rates, as well as a lower failed-to-cryopreserve rate, in recent studies compared to those released a decade ago. The studies from Asia reported higher sperm disposal and pregnancy rates than in other continents. Our analysis showed clinical pregnancy rates per cycle of 34% (27-41%), 24% (14-35%), and 9% (5-15%) and delivery rates per cycle of 23% (17-30%), 18% (11-26%), and 5% (1-9%) for ICSI, IVF, and IUI, respectively.

LIMITATIONS REASONS FOR CAUTION

As with all meta-analyses, some limitations should be considered. The first limitation of our study is that the data span 36 years. During this time, the World Health Organization has revised its sperm analysis standards, and other important changes have been made. There is also a limitation in that the outcome does not analyze the correlation between the type of cancer and sperm quality. Many of the earlier studies were limited by small sample sizes and a lack of control groups. Furthermore, almost all studies did not consider the severity of the disease, which could potentially have a substantial impact on the results. Consequently, further research should evaluate the effect of the type of cancer and, in particular, the severity of the condition on sperm quality in order to draw more precise conclusions. Similarly, it is inappropriate that most studies failed to differentiate between patients with different types of tumors and instead drew generalized conclusions that are presumed to apply to all patients with cancer. In the present analysis, we did not have in-depth information on patients' disease, and although extensive efforts were made to conduct a thorough systematic review and meta-analysis of the outcomes for patients with various types of tumors, the results must be acknowledged as being subject to bias. However, the use of average results obtained in each study, without the patient-level data, might also represent a source of bias.

WIDER IMPLICATIONS OF THE FINDINGS

Sperm cryopreservation is an effective fertility preservation method and may benefit patients with cancer. The observed utilization rate of frozen sperm at 9% may underestimate the actual usage, as the short follow-up period is inadequate for obtaining comprehensive data on the use of frozen sperm in young cancer survivors. ART plays an important role in fertility preservation and the achievement of pregnancy, with this meta-analysis showing that ICSI delivers better clinical outcomes than IVF or IUI in patients with cancer undergoing fertility preservation.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Natural Science Foundation of China (grant no. 82001634, 81960550), and the China Postdoctoral Science Foundation (2019M661521). There are no competing interests to declare.

REGISTRATION NUMBER

CRID 42022314460.

Exploring the impact of pericentric inversion of chromosome 9 on fertility in sperm donors

ABSTRACT

Pericentric inversion of chromosome 9 (inv[9]) is a common chromosomal structural variant, but its impact on clinical outcomes remains debated. The screening criteria of sperm banks are rarely mentioned to individuals with inv(9). In this study, we evaluated the fertility of sperm donors with inv(9) who met eligibility criteria for sperm banks (inv[9]-eligible donors). From March 2004 to May 2022, chromosomal analysis of 16 124 sperm donors at CITIC-Xiangya Human Sperm Bank in Hunan Province (Changsha, China) found that 251 (1.6%) had chromosome variations, with inv(9) being the most prevalent at 1.1%. All 169 inv(9)-eligible donors were contacted to collect fertility outcome data, along with 206 eligible donors without inv(9) as controls. In addition, semen samples from inv(9)-eligible donors and eligible donors underwent assessments of sperm fluorescence in situ hybridization (FISH), mitochondrial membrane potential, DNA fragmentation index, acrosome integrity, reactive oxygen species (ROS), and sperm morphology. Results showed that inv(9) did not significantly increase reproductive risks overall. Despite detecting ROS level differences, the clinical impact may be insignificant. This study provides new data on the inv(9) population that can serve as a valuable reference for decision-making by sperm banks as well as for genetic counseling and clinical guidance for individuals carrying inv(9) variant.

Long-term storage modifies the microRNA expression profile of cryopreserved human semen

The global practice of cryopreservation of human semen is commonplace in Assisted Reproductive Technology (ART) labs and sperm banks. However, information on the effects of long-term cryopreservation on semen is limited to clinical data summaries and descriptions. For this study, we prepared 4 semen specimens of fresh semen, 4 specimens cryostored for at least 1 year, 3 specimens cryostored for at least 5 years, 4 specimens cryostored for at least 10 years, and 3 specimens cryostored for at least 15 years. Total RNA was extracted from each sample, amplified, labeled, and mapped to the known primary microRNA (miRNA) in the miRBase database, enabling the prediction of novel miRNAs. We found that cryopreservation can lead to changes in miRNA expression, and with the increase in storage time, these changes became more pronounced. Meanwhile, the expression of let-7d-3p, let-7c-5p and let-7i-3p miRNAs changed dynamically over cryostorage time in frozen-thawed human sperm. Furthermore, we analyzed the time-dependent dynamics of cryostorage-expressed miRNAs and their target mRNAs and found that half of the target genes were expressed in oocytes. These intersection genes were mainly enriched in cancer and cytoskeletal signaling pathways. Our findings showed that the miRNA expression profile of cryopreserved human semen is modified by long-term storage. Furthermore, as the storage time increases, the impact on human sperm becomes more pronounced in terms of miRNAs, which may have an effect on subsequent fertilization and embryonic development.

Genetic testing of sperm donors in China: a survey of current practices

Background

The National Health and Family Planning Commission of China (NHFPCC) issued the "Measures for the Management of Human Sperm Banks," which was revised in 2003 and is still in effect today. One of the standard guidelines is that potential donors undergo laboratory testing to exclude infectious and genetic diseases and karyotype analysis. However, patient demands for donor genetic testing have also increased, and only karyotype analysis to exclude genetic diseases is not sufficient to meet these demands.

Objective

To examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks.

Materials and methods

An electronic survey was distributed to twenty-seven sperm banks to examine donor genetic screening practices at sperm banks in China and to evaluate the qualifications and skills of genetic counselors at the banks. Twenty-six human sperm banks responded to a 32-question survey about their current practices related to genetic testing of sperm donors.

Results

The 26 sperm banks reported that all qualified sperm donors undergo karyotype analysis; 22 banks (84.6%) collected three generations of family history from each qualified sperm donor; 10 (38.5%) reported that they attempted to accommodate special requests from donor semen recipients for particular genetic tests. Only 2 of the 26 (7.7%) sperm banks reported that they performed whole-exome sequencing. At all the sperm banks, consent for genetic testing was obtained as part of the overall contract for sperm donors. Nineteen (73.1%) sperm banks had genetic counselors on their staff, while six (23.1%) had no genetic counselors on their staff but had access to genetic counselors at the hospital. Only one (3.8%) sperm bank had no genetic counselors on their staff or at the hospital.

Conclusions

The need for larger scale genetic testing of donors and recipients and an extensive panel of genetic tests specific to the Chinese population. Additionally, professionally trained geneticists must be employed as genetic counsellors so that the results of genetic tests and their implications can be explained to donors.

CBPH assay for the highest sensitive detection of SARS-COV-2 in the semen

BACKGROUND

Great concerns have been raised on SARS-CoV-2 impact on men's andrological well-being, and many studies have attempted to determine whether SARS-CoV-2 is present in the semen and till now the data are unclear and somehow ambiguous. However, these studies used quantitative real-time (qRT) PCR, which is not sufficiently sensitive to detect nucleic acids in clinical samples with a low viral load.

METHODS

The clinical performance of various nucleic acid detection methods (qRT-PCR, OSN-qRT-PCR, cd-PCR, and CBPH) was assessed for SARS-CoV-2 using 236 clinical samples from laboratory-confirmed COVID-19 cases. Then, the presence of SARS-CoV-2 in the semen of 12 recovering patients was investigated using qRT-PCR, OSN-qRT-PCR, cd-PCR, and CBPH in parallel using 24 paired semen, blood, throat swab, and urine samples.

RESULTS

The sensitivity and specificity along with AUC of CBPH was markedly higher than the other 3methods. Although qRT-PCR, OSN-qRT-PCR and cdPCR detected no SARS-CoV-2 RNA in throat swab, blood, urine, and semen samples of the 12 patients, CBPH detected the presence of SARS-CoV-2 genome fragments in semen samples, but not in paired urine samples, of 3 of 12 patients. The existing SARS-CoV-2 genome fragments were metabolized over time.

CONCLUSIONS

Both OSN-qRT-PCR and cdPCR had better performance than qRT-PCR, and CBPH had the highest diagnostic performance in detecting SARS-CoV-2, which contributed the most improvement to the determination of the critical value in gray area samples with low vrial load, which then provides a rational screening strategy for studying the clearance of coronavirus in the semen over time in patients recovering from COVID-19. Although the presence of SARS-CoV-2 fragments in the semen was demonstrated by CBPH, COVID-19 is unlikely to be sexually transmitted from male partners for at least 3 months after hospital discharge.

Comparison of Clinical Outcomes, Risks, and Costs for 20,910 Donor In Vitro Fertilization and 16,850 Donor Artificial Insemination Treatment Cycles: A Retrospective Analysis in China

PURPOSE

To evaluate the effectiveness of donor in vitro fertilization (IVF-D) and donor artificial insemination (AI-D) in clinical outcomes, risks, and costs.

METHODS

This study analyzed the cycle changes and clinical outcomes in 20,910 IVF-D and 16,850 AI-D cycles between 2013 and 2021 in the Reproductive and Genetic Hospital of CITIC-Xiangya. A cost-effectiveness analysis was performed to evaluate the costs per couple and per live birth cycle in the two treatment groups.

RESULTS

IVF-D had higher pregnancy and live birth rates than AI-D (p < 0.001). The cumulative pregnancy and live birth rates for three AI-D cycles were 41.01% and 32.42%, respectively, higher than the rates for one or two AI-D cycles. The multiple birth and birth defect rate of AI-D was lower than that of IVF-D significantly. IVF-D mean cost per couple was higher than that of AI-D (CNY32,575 vs. CNY11,062, p < 0.001), with a mean cost difference of CNY21,513 (95% confidence interval, CNY20,517-22,508). The mean costs per live birth cycle for IVF-D and AI-D were CNY49,411 and CNY31,246, respectively.

CONCLUSION

AI-D is more cost-effective and poses a lower risk for infertility couples than IVF-D, and patients should undergo three AI-D cycles to obtain the highest success rate.

Genetic testing of sperm donors at a human sperm bank in China

Background

In China, numerous human sperm banks only perform three-generation family history evaluation to exclude genetic diseases with clinical symptoms; therefore, many inherited risks cannot be detected before donor qualification even when a thorough genetic family history evaluation has been performed. Hence, the risk of recessive disease inheritance persists with the current eligibility guidelines in China regarding the donor selection process.

Methods

Retrospective study that reviewed the genetic test analyses and clinical outcomes of young adult men who were qualified sperm donors at the Hunan Province Human Sperm Bank of China from January 1, 2018, to May 1, 2021. We included a total of 3231 qualified sperm donors: all donors underwent primary screening for thalassemia and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Whereafter, 278 of donors underwent genetic testing for specific genes, and 43 donors underwent whole exome sequencing.

Results

2.4% of 3231 qualified sperm donors might have thalassemia and 1.4% might have G6PD deficiency. Sperm donors with thalassemia and G6PD deficiency would be eliminated. Specific gene testing identified 7 of the 278 donors (2.5%) as carriers of at least one pathogenic or likely pathogenic variant in a gene, including 1.9% of 154 donors (3/154) as carrier variants in α-Like or β-Like globin genes, 17.6% of 17 donors (3/17) as carrier variants in GJB2, 12.5% of 8 donors (1/8) as carrier variants in SMN1. In addition, among the 43 sperm donors carrying the 111 pathogenic/likely pathogenic variants, eight (18.6%) were carriers of pathogenic variants of the GJB2 gene. The frequency, therefore, was approximately 1 in 5.

Conclusions

The data suggest that used blood routine and RDT can make a preliminary screening of sperm donors, and special gene testing should be performed for sperm donors according to the regional incidence of specific genetic diseases. Meanwhile, whole exome sequencing can be used as a supplementary application in sperm donor genetic testing, and aid a successful and healthy pregnancy. However, industry guidelines must be modified to incorporate its use.

Evaluating an external quality assurance program for semen analysis in China during 2009-2020

INTRODUCTION

Semen analysis (SA) plays a key role in guiding treatments of male reproductive diseases and infertility due to male factors; however, it remains challenging to conduct an accurate SA due to lack of standardization, highly subjective assessments, and problems with automated procedures. Therefore, quality assurance (QA) and teaching courses are essential for making the laboratory results more consistent.

MATERIALS AND METHODS

The external quality assurance (EQA) scheme was organized by national human sperm bank technology training bases in Guangdong province in China between 2009 and 2020. Until 2020, 124 laboratories from China participated in the EQA program. The EQA scheme per year has been organized involving two semen aliquots for sperm concentration, two video recordings for motility, and two smears for sperm morphology. All samples used in the EQA scheme were obtained from different healthy donors or patients.

RESULTS

We estimated that the median coefficient of variation (CV) of sperm concentration, ignoring the method used, was 26.6%. Using a 100 µm deep counting chamber led to a decreasing CV of 13.6%. For sperm motility, the median CV of nonprogressive motility was high (50.8%), but the CV of progressive motility (13.2%), immotile sperm (14.3%), and total motility (11.8%) were acceptable. The morphology assessment revealed large variability (44.4%) irrespective of the classification criteria.

DISCUSSION

The reduction of interlaboratory variability is still a challenge during SA in China. Therefore, it is critical to increase awareness of joining EQA schemes and establish standardized training centers to follow WHO-recommended procedures toward Chinese standards.

[Sperm small non-coding RNAs and intergenerational inheritance]

Recent studies have confirmed that, in addition to sperm DNA, environmental exposure factors such as parental diet structure and stress state affect early embryonic development and offspring growth, thus leading to cross-generational inheritance of acquired traits. Many studies also show that environmental stressors can change the expression level of sperm small non-coding RNAs (sncRNAs). Furthermore, as the carrier of paternal genetic information transmission and epigenetic marker, sncRNAs are directly or indirectly involved in epigenetic regulation, mediating inter-generational inheritance of acquired traits. This review focuses on the two sncRNAs derived from microRNA (miRNA) and tRNA (tsRNA) in sperm epigenetics research.

Update on techniques for cryopreservation of human spermatozoa

In the 1960s, sperm cryopreservation was developed as a method to preserve fertility. Currently, techniques for the cryopreservation of human spermatozoa have been widely used in assisted reproduction. However, although sperm cryobiology has made notable achievements, the optimal method for the recovery of viable spermatozoa after cryopreservation remains elusive. Postthawing sperm quality can be affected by cryoprotectants, ice formation, storage conditions, and osmotic stress during the freezing process. This review discusses recent advances in different cryopreservation techniques, cryoprotectants, and freezing and thawing methods during cryopreservation and new indications for the use of cryopreserved spermatozoa.

Micro-straw: An efficient cryopreservation carrier for rare human spermatozoa

BACKGROUND

Many cryopreservation carriers have been introduced to freeze rare human spermatozoa, however, these carriers relative attributes and comparative effectivenesses have not yet been systematically studied.

OBJECTIVES

Is the Micro-straw cryopreservation carrier more effective for cryopreserving rare human spermatozoa compared with the Cryoplus and LSL carriers?

MATERIALS AND METHODS

This study involves ninety-three samples from healthy sperm donors and forty samples from patients diagnosed with oligospermia, asthenospermia, oligoasthenospermia, or obstructive azoospermia. we determined the optimal freeze-thaw protocol for the Micro-straw carrier. The post-thaw survival rate, normal sperm morphology, acrosome integrity, and DNA fragmentation for Micro-straw, Cryoplus, and LSL carriers were then determined. Finally, we verified the effects of freezing using these carriers by comparing the qualities of post-thaw spermatozoa from patients.

RESULTS

The highest total motility (TM) and progressive motility (PR) survival rates were obtained by placing the Micro-straw at 1 cm above the LN₂ surface for 70 s during freezing and in a 42-°C water bath for 40 s during thawing. No differences were observed in PR survival rate, acrosome integrity, and DNA fragmentation of the post-thaw spermatozoa from the three carriers. However, the normal morphology rate of spermatozoa frozen using the Micro-straw carrier was higher than for the Cryoplus carrier (p < 0.05), and the TM survival rate of spermatozoa frozen with the Micro-straw was higher than that for the LSL carrier (p < 0.01). In verification tests, there were no significant differences in the quality of post-thaw spermatozoa cryopreserved using these carriers for both rare spermatozoa or epididymal sperm.

DISCUSSION AND CONCLUSION

Micro-straw, Cryoplus, and LSL carriers are all efficient means of freezing rare human spermatozoa. However, the Micro-straw carrier is more economical, safe, and user-friendly. This article is protected by copyright. All rights reserved.

MKK7-mediated phosphorylation of JNKs regulates the proliferation and apoptosis of human spermatogonial stem cells

BACKGROUND

Human spermatogonial stem cells (SSCs) are the basis of spermatogenesis. However, little is known about the developmental regulatory mechanisms of SSC due to sample origin and species differences.

AIM

To investigates the mechanisms involved in the proliferation of human SSC.

METHODS

The expression of mitogen-activated protein kinase kinase 7 (MKK7) in human testis was identified using immunohistochemistry and western blotting (WB). MKK7 was knocked down using small interfering RNA, and cell proliferation and apoptosis were detected by WB, EdU, cell counting kit-8 and fluorescence-activated cell sorting. After bioinformatic analysis, the interaction of MKK7 with c-Jun N-terminal kinases ( JNKs ) was verified by protein co-immunoprecipitation and WB. The phosphorylation of JNKs was inhibited by SP600125, and the phenotypic changes were detected by WB, cell counting kit-8 and fluorescence-activated cell sorting.

RESULTS

MKK7 is mainly expressed in human SSCs, and MKK7 knockdown inhibits SSC proliferation and promotes their apoptosis. MKK7 mediated the phosphorylation of JNKs, and after inhibiting the phosphorylation of JNKs, the phenotypic changes of the cells were similar to those after MKK7 downregulation. The expression of MKK7 was significantly downregulated in patients with abnormal spermatogenesis, suggesting that abnormal MKK7 may be associated with spermatogenesis impairment.

CONCLUSION

MKK7 regulates the proliferation and apoptosis of human SSC by mediating the phosphorylation of JNKs.

Clinical benefit for cryopreservation of single human spermatozoa for ICSI: A systematic review and meta-analysis

BACKGROUND

Systematic reviews have focused on sperm recovery and post-thaw parameters after cryopreservation, but there no information on the associated clinical outcomes. In recent years, an increasing number of studies have reported cryopreservation of a single sperm due to the importance of fertility preservation.

OBJECTIVES

To assess whether the cryopreservation of single human spermatozoa improves clinical outcomes in patients with azoospermia or severe oligospermia.

MATERIALS AND METHODS

We conducted an extensive literature search using the following databases, CENTRAL, CNKI, Cochrane Systematic Reviews, EMBASE, MEDLINE, PUBMED, and Web of Science for relevant studies published through December 31, 2019. We calculated the pooled proportions of cryopreservation of single human spermatozoon to assess the recovery, survival, fertilization, pregnancy, miscarriage, and delivery rates. Subgroup analyses were performed for the following covariates, a) different carriers, b) year of publication, and c) source of sperm.

RESULTS

We included 25 studies, which included 13 carriers. The pooled proportion of recovery rate of spermatozoa cryopreserved was 92% (95% CI, 87%-96%), and the survival, fertilization, pregnancy, miscarriage, and delivery rate were 76% (95% CI, 69%-83%), 63% (95% CI, 58%-67%), 57% (95% CI, 39%-74%), 12% (95% CI, 0%-33%), and 40% (95% CI, 12%-71%), respectively. Based on the subgroup analysis, the recovery and survival rates of frozen spermatozoa in subgroup of different carriers were statistically significant. In the past decaade, frozen single human spermatozoon technology has improved the recovery rates of frozen-thawed spermatozoa. However, the differences in clinical outcomes of frozen spermatozoa in subgroup of different sources of sperm were not statistically significant.

DISCUSSION AND CONCLUSION

The techniques for single human spermatozoa are feasible and efficient and may benefit patients with severe oligospermia or azoospermia. This article is protected by copyright. All rights reserved.

[Advances in researches on cryopreservation of testicular spermatozoa]

Infertility affects approximately 20% of childbearing couples in the world, and azoospermia accounts for 10－15% of the causes of male infertility. The use of fresh or frozen-thawed testicular sperm for intracytoplasmic sperm injection (ICSI) has become a main method for azoospermia patients to realize their dream for reproduction. However, testicular spermatozoa are not further matured in the epididymis and therefore have an obviously lower anti-freezing ability than ejaculated sperm. The viability and retrieval rate of sperm are low after freeze-thaw with the conventional method of cryopreservation. Since the first live birth with frozen-thawed testicular spermatozoa, continuous improvement has been made in the methods of testicular sperm cryopreservation and increased the viability and retrieval rate of spermatozoa after freeze-thaw. This review focuses on the methods of testicular sperm cryopreservation in the past 20 years to provide a theoretical basis for the development of assisted reproductive technology.

Risks associated with cryopreserved semen in a human sperm bank during and after the COVID-19 pandemic

RESEARCH QUESTION

What are the risks associated with cryopreserved semen collected during and after the coronavirus disease 2019 (COVID-19) pandemic wave in Wuhan, China?

DESIGN

Retrospective cohort study involving young adult men who were qualified sperm donors at the Hunan Province Human Sperm Bank (China) during the pandemic wave (1 January 2020 to 30 January 2020) and after the wave and return to work (7 April 2020 to 30 May 30 2020). One hundred paired semen and blood specimens from 100 donors were included. One-step single-tube nested quantitative real-time polymerase chain reaction (OSN-qRT-PCR) was used to detect SARS-CoV-2. Moreover, to control the unacceptable risk of false-negative results, a second round of screening was performed with pooled RNA from negative semen samples using crystal digital PCR (cd-PCR).

RESULTS

For individual blood and semen samples, the target genes, namely the nucleocapsid protein (N) and open reading frame (ORF-1ab) genes, tested negative in all of the 100 paired samples. Further, as per cd-PCR results, there were >20,000 droplets per well in the RNA for each combined sample and no positive droplets were present for either of the aforementioned target genes. A total of 100 paired semen and blood samples from these two groups tested negative for SARS-CoV-2.

CONCLUSIONS

Cryopreserved semen at the Hunan Province Human Sperm Bank during and after the COVID-19 pandemic wave was free of SARS-CoV-2 and was judged safe for external use in the future.

Influence of sperm morphology on pregnancy outcome and offspring in in vitro fertilization and intracytoplasmic sperm injection: a matched case-control study

Sperm morphology was once believed as one of the most predictive indicators of pregnancy outcome in assisted reproductive technology (ART). However, the impact of teratozoospermia on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcomes and its offspring remains inconclusive. In order to evaluate the influence of teratozoospermia on pregnancy outcome and newborn status after IVF and ICSI, a retrospective study was conducted. This was a matched case-control study that included 2202 IVF cycles and 2574 ICSI cycles and was conducted at the Reproductive and Genetic Hospital of CITIC-Xiangya in Changsha, China, from June 2013 to June 2018. Patients were divided into two groups based on sperm morphology: teratozoospermia and normal sperm group. The pregnancy outcome and newborn outcome were analyzed. The results indicated that couples with teratozoospermia had a significantly lower optimal embryo rate compared to those with normal sperm morphology in IVF (P = 0.007), while there were no statistically significant differences between the two groups in terms of the fertilization rate, cleavage rate, implantation rate, and pregnancy rate (all P > 0.05). Additionally, teratozoospermia was associated with lower infant birth weight in multiple births after IVF. With regard to ICSI, there was no significant difference in both pregnancy outcome and newborn outcome between the teratozoospermia and normal groups (both P > 0.05). Furthermore, no increase in the risk of birth defects occurred in the teratozoospermia group after IVF/ICSI. Consequently, we believe that teratozoospermia has limited predictive value for pregnancy outcomes in IVF/ICSI, and has little impact on the resulting offspring if multiple pregnancy is avoided.

Improving native human sperm freezing protection by using a modified vitrification method

Slow freezing is the most commonly used technique for the cryopreservation of spermatozoa in clinical practice. However, it has been shown to have a negative impact on sperm function and structure. Vitrification as a successful alternative method has been proved to have better protective effects on human embryos, but vitrification of spermatozoa is still subject to low recovery rates. In this study, a modified vitrification method for native spermatozoa was developed. A total of 28 semen samples were included; each sample was divided into three equal parts and assigned to fresh, slow freezing, and vitrification groups. Sperm vitality, motility, morphology, DNA integrity, and acrosome reaction were assessed for each of the groups. The results showed that vitrification achieves better results for several sperm protection parameters than slow freezing; vitrification achieves a higher recovery rate (P < 0.05), motility (P < 0.05), morphology (P < 0.05), and curve line velocity (P < 0.05) than slow freezing. Furthermore, DNA fragmentation was decreased (P < 0.05) and better acrosome protection (P < 0.05) was exhibited in the spermatozoa after vitrification. Principal component analysis of all sperm parameters revealed that the vitrification cluster was closer to the fresh cluster, indicating that spermatozoa are better preserved through vitrification. In conclusion, while both slow freezing and vitrification have negative effects on sperm function and structure, the vitrification protocol described here had a relatively better recovery rate (65.8%) and showed improved preservation of several sperm quality parameters compared with slow freezing.

HIV prevalence among 338,432 infertile individuals in Hunan, China, 2012-2018: A cross-sectional study

BACKGROUND

The prevalence of human immunodeficiency virus (HIV) varies markedly among different risk groups in China, spreading fromhigh-risk populations to the general population. Indeed, China is in a critical period of HIV/acquired immunodeficiency syndrome (AIDS) prevention and control; however, data regarding HIV testing, infection and coinfection among infertile couples are lacking. This study aimed to estimate the HIV/AIDS prevalence to identify risk factors among infertile couples in Hunan, China.

METHODS

A cross-sectional hospital-based study was conducted to evaluate the prevalence of HIV/other infections (hepatitis B virus (HBV), hepatitis C virus (HCV), syphilis, and Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium (MG) infections) among 338,432 infertile individuals in Hunan, China, from 2012 to 2018. We calculated linear trends in prevalence using bivariate linear regression.

RESULTS

The overall prevalence rates of HIV, chlamydia, gonorrhea, MG, syphilis, and HBV and HCV antibody positivity in this study were 0.04%, 1.73%, 0.05%, 2.60%, 2.15%, 12.01% and 0.56%, respectively. The predominant infection was HBV, followed by MG, syphilis, and chlamydia. Only 1.13% of the participants (382/338432) reported sexually transmitted disease (STD) signs and symptoms suggesting genital tract infection. However, from 2012-2018, the variation in HIV prevalence was not significant (β = 0.000, PTREND = 0.907). The characteristics of the HIV-infected infertile population have not shifted dramatically, with women accounting for 32.56% of HIV cases in China. Overall, 87.60% of HIV-infected individuals have a relatively low education. In total, 37.98% of HIV-positive patients engage in high-risk behaviors.

CONCLUSIONS

This study expands upon existing knowledge of HIV prevalence in the infertile Chinese population. However, much work is needed to achieve popularization of prevention knowledge and change concept. Routine HIV screening is urgently needed for all adults with high-risk behaviors.

Novel micro-straw for freezing small quantities of human spermatozoa

OBJECTIVE

To evaluate a novel micro-straw as an efficient, simple method for freezing a small number of human spermatozoa for intracytoplasmic sperm injection (ICSI).

DESIGN

Prospective cohort study.

SETTING

Sperm bank.

PATIENT(S)

Men with severe oligozoospermia or azoospermia undergoing a total of 143 ICSI cycles at the CITIC-Xiangya Hospital of Reproduction and Genetics from June 1, 2015, to June 31, 2019, and 20 donors at the Hunan Province Human Sperm Bank from 2001 to 2016.

INTERVENTION(S)

Analysis of sperm samples and clinical outcomes after sperm use.

MAIN OUTCOME MEASURE(S)

Clinical information, including number of motile sperm before and after freezing, freeze-thaw survival rates, two-pronuclear fertilization rates, clinical pregnancy, and early pregnancy loss rates after sperm use.

RESULT(S)

In the feasibility experiment using the micro-straw, we found a freeze-thaw survival rate of 73% ± 8.3% and no difference in normal sperm morphology, normal acrosome integrity, or DNA fragmentation index between the micro-straw and 1.8-mL cryotubes. The prospective cohort included 1,325 cases, and we collected sperm from testicular, epididymis, and ejaculation sources. We observed motile sperm in 1,294 (97.6%) of 1,325 frozen-thawed samples. Postthaw sperm were available for ICSI in 140 (97.9%) of 143 of cycles. The fertilization, cleavage, and high-quality embryo rates were 1,007 (81.7%) of 1,233; 995 (98.8%) of 1,007; and 537 (53.9%) of 995, respectively. Sixty-nine (49%) clinical pregnancies were achieved, and the miscarriage rate was 6 (8.6%) of 69.

CONCLUSION(S)

The micro-straw is suitable and clinically useful for the cryopreservation of small numbers of spermatozoa.

Mycoplasma genitalium incidence, treatment failure, and resistance: a retrospective survey of men of infertile couples from a hospital in China

BACKGROUND

Mycoplasma genitalium infection is significantly associated with an increased risk of male infertility. To date, few large M. genitalium studies have been conducted in China.

OBJECTIVE

This study aimed to estimate the M. genitalium incidence and treatment failure and to provide information regarding the resistance of M. genitalium to macrolide and tetracycline antibiotics among men of infertile couples in China.

MATERIALS AND METHODS

This study was performed as a retrospective survey of seminal and meatus urinarius secreta specimens of 30,094 men of infertile couples collected and used for microbiological tests for the evaluation of genital tract infections (Mycoplasma genitalium, Chlamydia trachomatis, and Neisseria gonorrhoeae) between October 2016 and December 2017. Mycoplasma genitalium RNA was detected using novel simultaneous amplification testing. Macrolide and tetracycline resistance screening was introduced using polymerase chain reaction (PCR) and Sanger sequencing.

RESULTS

The incidence of M. genitalium was 2.49% (749 of 30,094; 95% confidence interval (CI), 2.31-2.66%). After antibiotic treatment, the mean values of semen parameters increased from those measured before treatment. The overall incidence of treatment failure was 17.56% (82/467; 95% CI, 14.10%-21.02%) (112-26-4 = 82), irrespective of the drug used. Resistance to macrolide and tetracycline antibiotics was detected in 58 samples (58/60, 96.67%; 95% CI, 91.99-101.34%) and 27 samples (27/60, 45.00%; 95% CI, 32.04-57.96%), respectively.

CONCLUSIONS

Although the M. genitalium incidence was relatively low, the detection of macrolide antibiotic resistance in >96.67% of the treatment failure samples most likely explained the high azithromycin treatment failure rate (73/195, 37.44%) in our study. These findings indicate the need to provide resistance testing and to reappraise the recommended antimicrobial options in China.

[Correlation of Mycoplasma genitalium infection with male infertility]

OBJECTIVE

To explore the correlation of Mycoplasma genitalium (MG) infection with male infertility.

METHODS

Totally, 27 314 males with infertility and 200 fertile sperm donors underwent MG and routine seminal examinations. The infertile men were divided into azoospermia, oligozoospermia, asthenozoospermia, oligoasthenospermia, and normal semen quality groups based on the results of seminal examination, the 27 286 of them with age data into eight age groups (<21, 21－25, 26－30, 31－35, 36－40, 41－45, 46－50 and ≥51 years old), and the 9 058 with definite diagnosis into primary and secondary infertility groups. Fifty-six cases of MG infection among the infertile males were treated with antibiotics for 2 weeks and examined for changes of the semen parameters.

RESULTS

Compared with the normal controls, the oligozoospermia patients showed a significantly higher rate of MG infection (0.50% vs 3.62%, P = 0.024), the highest in the ≥51 yr group (3.68%, P = 0.021), followed by the 21－25 yr group (3.00%, P = 0.048), and so did the infertile males (3.64%, P = 0.011), the men with primary infertility (3.73%, P = 0.010) and those with secondary infertility (3.57%, P = 0.015). MG infection was found to be associated with oligozoospermia (OR = 7.471, 95% CI: 1.001－55.784), primary infertility (OR = 7.704, 95% CI: 1.073－55.309) and secondary infertility (OR = 7.362, 95% CI: 1.026－52.837) but not with the age of the patients. Both sperm concentration and sperm count were significantly lower in the infected men before treatment than in the non-infection group after treatment (P < 0.05).

CONCLUSIONS

MG infection is related to male infertility and reduces the semen volume and sperm concentration, but does not affect sperm motility.

Comparative Proteomics Reveal the Association between SPANX Proteins and Clinical Outcomes of Artificial Insemination with Donor Sperm

Semen analysis is used for diagnosing male infertility and evaluating male fertility for more than a century. However, the semen analysis simply represents the population characteristics of sperm. It is not a comprehensive assessment of the male reproductive potential. In this study, 20 semen samples from human sperm bank with distinctive artificial insemination with donor sperm (AID) clinical outcomes were collected and analyzed using a two-dimensional differential in-gel electrophoresis (2D-DIGE); 45 differentially expressed protein spots were obtained, and 26 proteins were identified. Most differentially expressed proteins were related to sperm motility, energy consumption, and structure. These identified proteins included several sperm proteins associated with the nucleus on the X chromosome (SPANX) proteins. This prospective study aimed to investigate the association between the expression levels of SPANX proteins and the AID clinical outcomes. The proteins identified in this study provided a reference for the molecular mechanism of sperm fertility and revealed a predictive value of the SPANX proteins.

[In vitro culture medium for sparse spermatozoa improves human sperm motility]

OBJECTIVE

To investigate whether in vitro culture medium (IVCM) for sparse spermatozoa can improve human sperm motility for the purpose of helping clinicians, laboratorians and patients choose a better strategy of assisted reproduction.

METHODS

Semen samples were obtained from 178 males for routine semen examination from March to August 2016, including 151 cases of asthenozoospermia and 27 cases of normal sperm motility. A total of 200 μl was collected from each sample and divided into two equal portions and equal volumes of IVCM (experimental group) and F10 (1×) (control group) were added to the two portions, respectively, followed by 30-minute incubation at 37℃ in an incubator with 5% CO2. Sperm concentration, motility and viability and the percentages of progressively motile, non-progressively motile and immotile sperm were recorded before and after incubation.

RESULTS

After activated with IVCM, neither the samples with asthenozoospermia nor those with normal sperm motility showed any statistically significant difference in sperm viability from the baseline or the control group (P>0.05). The rates of progressively and non-progressively motile sperm from the asthenozoospermia males were increased by 14.02% and 4.86% respectively, while that of immotile sperm decreased by 19.01% in the experimental group (P >0.01), and similar results were observed in the semen samples from the men with normal sperm motility. The percentage of reduced immotile viable sperm was positively correlated with that of immotile viable sperm in both the asthenozoospermia patients (r = 0.260, P <0.01) and the men with normal sperm motility (r = 0.679, P <0.01).

CONCLUSIONS

IVCM can increase sperm motility without affecting sperm viability in men with either asthenozoospermia or normal sperm motility. The larger the proportion of immotile viable sperm, the higher the percentages of progressively and non-progressively motile sperm in the semen after IVCM activation, and this correlation is more significant in men with normal sperm motility than in asthenozoospermia patients.

[Safety of the offspring conceived by assisted reproductive technology with cryopreserved donor sperm]

OBJECTIVE

To investigate the pregnancy outcomes of assisted reproductive technology (ART) with cryopreserved donor sperm and the safety of the offspring thus conceived.

METHODS

The Human Sperm Bank of CITIC Xiangya Hospital provided cryopreserved donor semen to 31 reproductive centers in China between January 2006 and December 2012, with which 50247 ART cycles were accomplished. We compared the rates of birth defects and spontaneous abortion of intracervical insemination (ICI), intrauterine insemination (IUI), in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI).

RESULTS

A total of 39 047 ART cycles were performed by artificial insemination with cryopreserved donor sperm, including 36 674 cycles of ICI and 2 372 cycles of IUI. Among the 8 612 clinical pregnancies achieved by ICI, there were 917 cases of spontaneous abortion (at <28 gestational wk) (10.6%) and 6133 live births, with 43 cases of birth defect (0.70%). Of the 547 clinical pregnancies achieved by IUI, there were 41 cases of spontaneous abortion (7.5%) and 426 live births, with 2 cases of birth defect (0.47%). Totally, 11 200 cycles of IVF and ICSI were accomplished with cryopreserved donor sperm. Of the 5 860 clinical pregnancies achieved by IVF, there were 456 cases of spontaneous abortion (7.8%) and 5089 live births, with 55 cases of birth defect (1.08%). Among the 350 clinical pregnancies achieved by ICSI, there were 30 cases of spontaneous abortion (8.6%) and 229 live births, with 3 cases of birth defect (1.31%). The birth defect rate of ART with cryopreserved donor sperm was significantly lower than that published by the Chinese Ministry of Health (0.86% vs 1.53%,P<0.01).

CONCLUSIONS

The safety of the offspring conceived by ART with cryopreserved donor sperm is controllable.

Effect of high-intensity exercise on interleukin-15 expression in rabbit synovia

The objective of this study was to examine the effect of high-intensity exercise on interleukin-15 (IL-15) expression in rabbit synovia. We utilized 24 New Zealand white rabbits, which were randomly divided equally into high-intensity exercise and control groups. The former were forced to run for 60 min/day over 4 weeks at the speed of 30 m/min. The histological changes of cartilage and knee joint synovia were investigated with hematoxylin and eosin staining. Immunohistochemistry and enzyme-linked immunosorbent assays were performed to measure IL-15 expression. From these analyses, we identified knee articular cartilage damage and synovitis in the high-intensity exercise group. This group also exhibited higher IL-15 expression in their synovial fluid and tissues than was observed in the control group (P < 0.05). These results suggested that high-intensity exercise might lead to synovitis and articular cartilage damage, and that IL-15 overexpression in synovia might be associated with post-traumatic osteoarthritis.

Effects of high intensity exhaustive exercise on SOD, MDA, and NO levels in rats with knee osteoarthritis

The aim of this study was to investigate the impact of high intensity exhaustive exercise on nitric oxide (NO), malondialdehyde (MDA), and superoxide dismutase (SOD) expression in rats with knee osteoarthritis. Sprague Dawley rats were randomly divided into control (N = 5) and model (N = 35) groups; the model group was further divided into quiet (N = 5), low- (N = 15) and high- (N = 15) intensity exhaustive exercise groups. The low- and high-intensity groups were randomly divided into pre-exercise (N = 5), immediate post-exercise (N = 5), and 24-h post-exercise (N = 5) groups according to different time points for detection. NO, MDA, and SOD levels were compared between each group. The SOD levels in the quiet, low-, and high-intensity exhaustive exercise groups were lower than that in the control group, whereas the NO and MDA levels were higher in the former groups than in the controls (P < 0.05). The SOD level in the 24-h post-low intensity exhaustive exercise group was higher than that in the 24-h post-high intensity exhaustive exercise group, whereas the NO and MDA levels were lower in the 24-h post-low intensity than in the post-high intensity exercise group (P < 0.05). Overall, the results demonstrated that with the increase of exercise intensity, the SOD activity in the rats with knee osteoarthritis decreased gradually, whereas the MDA and NO levels gradually increased. Thus, the greater the exercise intensity, the more serious the impact on knee osteoarthritis.

Polymorphism analysis of the intron one of insulin-like growth factor 2 receptor gene (IGF2R) in FFRC strain common carp (Cyprinus carpio L.) and its relationship with growth performance

The insulin-like growth factor 2 receptor gene (IGF2R) encodes a transmembrane protein receptor and acts to sequester and degrade excess circulating insulin-like growth factor 2, which is critical for normal mammalian growth and development. Thus, IGF2R may serve as a candidate gene underlying growth trait in the common carp. In this study, we isolated the intron one of common carp IGF2R and detected the diversity in 3 continuous generations of FFRC strain common carp. A total of 8 loci were detected within this region, which were named in accordance with their location (i.e., Loc84, Loc106, Loc119, Loc130, Loc145, Loc163, Loc167, and Loc265). Loc106, Loc119, and Loc145 were moderately polymorphic; while Loc84, Loc130, Loc163, Loc167, and Loc265 exhibited slight level of polymorphism. However, significant differences between polymorphism information content values were not observed among the different generations. For Loc145, all generations deviated from Hardy-Weinberg equilibrium. The total number of significant linkage disequilibria for all generations equaled 40. Among them, 4 pairs were detected in each population, while 8 pairs were found in the 2nd and 3rd generations. For Loc130, the G/T genotype exhibited higher body weight when compared to that of the G/G genotype. The frequency of the homozygous G/G genotype reached 87.96%; thus, we can improve FFRC strain common carp growth performance by increasing the percentage of the G/T genotype within a breeding population. Therefore, the G/T genotype could be used as a molecular marker for superior growth traits.

Does sperm morphology affect the outcome of intrauterine insemination in patients with normal sperm concentration and motility?

The aim of this study was to assess the correlation of sperm morphology with the intrauterine insemination (IUI) outcome in patients with normal sperm concentration and motility. About 412 couples who underwent 908 IUI cycles were involved in the present study. A total of 110 clinical pregnancies were achieved with a pregnancy rate of 12.11% per cycle. The pregnancy rates per cycle were 7.60%, 12.67%, 13.62% and 13.13% in patients with <5%, 5-9%, 10-14% and >14% normal forms, respectively. The lowest pregnancy rate (7.60%) was obtained in the group with normal forms below 5%. However, this rate was not significantly different from other subgroups. Moreover, no pregnancies occurred in women >35 years old with normal sperm forms below 5%, in comparison with that in other subgroups of the same age. For women younger than 35 years old, no significant difference in pregnancy rate was observed in terms of different level of morphologically normal sperm. Our results show that for patients with normal sperm concentration and motility, IUI is recommended for first-line treatment when the woman is younger than 35 years, or morphologically normal sperm is ≥ 5%. IVF/ICSI should be performed when the normal forms are <5% and female age is > 35 years.

Sperm banking for male reproductive preservation: a 6-year retrospective multi-centre study in China

Sperm banking can preserve male fertility effectively, but the current conditions of sperm cryopreservation in China have not been investigated. This retrospective investigation was based on data collected at multiple centres in China from January 2003 to December 2008. The collected data included urogenital history, indication for cryopreservation, semen parameters, use rate, type of assisted reproductive technique (ART) treatment and pregnancy outcome. The study population included 1 548 males who had banked their semen during the study period at one of the clinics indicated above. Approximately 1.9% (30/1 548) of the cryopreserved semen samples were collected from cancer patients; about 88.8% (1 374/1 548) of the patients had banked their semen for ART and 8.6% (134/1 548) had a male infertility disease (such as anejaculation, severe oligozoospermia and obstructive azoospermia). The total use rate of cryopreserved semen was 22.7% (352/1 548), with 119 live births. The cancer group use rate was 6.7% (2/30), with one live birth by intracytoplasmic single sperm injection (ICSI). The ART group use rate was 23.2% (319/1 374), with 106 live births. The reproductive disease group use rate was 23.1% (31/134), with 12 live births. The semen parameters in each category varied; the cancer patient and infertility disease groups had poor semen quality. In vitro fertilization (IVF) and ICSI were the most common ART treatments for cryopreserved sperm. Semen cryopreservation as a salvage method is effective, but in many conditions it is underutilized, especially in cancer patients. Lack of awareness, urgency of cancer treatment and financial constraints are the main causes of the low access rate. The concept of fertility preservation should be popularized to make better use of this medical service in China.

Proteome analysis of round-headed and normal spermatozoa by 2-D fluorescence difference gel electrophoresis and mass spectrometry

Globozoospermia is a severe form of teratozoospermia characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. Globozoospermia is diagnosed by the presence of 100% round-headed spermatozoa on semen analysis, and patients with this condition are absolutely infertile. The objective of this study was to investigate the differences in protein expression between human round-headed and normal spermatozoa. Two-dimensional (2-D) fluorescence difference gel electrophoresis (DIGE) coupled with mass spectrometry (MS) was used in this study. Over 61 protein spots were analysed in each paired normal/round-headed comparison, using DIGE technology along with an internal standard. In total, 35 protein spots identified by tandem mass spectrometry (MS/MS) exhibited significant changes (paired t-test, P < 0.05) in the expression level between normal and round-headed spermatozoa. A total of nine proteins were found to be upregulated and 26 proteins were found to be downregulated in round-headed spermatozoa compared with normal spermatozoa. The differentially expressed proteins that we identified may have important roles in a variety of cellular processes and structures, including spermatogenesis, cell skeleton, metabolism and spermatozoa motility.

[Establishment of a long-term culture system for mouse spermatogonial stem cells in vitro]

OBJECTIVE

To establish a long-term proliferation culture system for mouse spermatogonial stem cells.

METHODS

Testis tissues were obtained from 30 newborn male ICR mice on postnatal day 2-6. Testis cell suspension was collected by two-step enzymatic digestion prior to culture. The dissociated cells were aliquoted into tissue culture plates and cultivated with a modified system composed of serum-free defined medium on mouse embryonic fibroblasts (MEF) feeders. Their proliferation was determined by the BrdU incorporation test and the cultured cells identified by alkaline phosphatase (AP) activity, immunofluorescence staining and RT-PCR assay.

RESULTS

The cultures remained in a steady state and continued to generate germ cell colonies. The undifferentiated state was confirmed by strong positivity for AP activity, immunofluorescent staining of GFRalpha-1+ /Oct-4+ /VASA+ /SCP3- and GFRalpha-1+ /Oct-4+/SCP3- at the gene expression levels.

CONCLUSION

Mouse spermatogonial stem cells could be expanded in our defined culture system and passaged steadily in vitro. The harvested cells remained in an undifferentiated state, which has provided a good platform for the study of spermatogenesis in vitro.

Establishment of a high-resolution 2-D reference map of human spermatozoal proteins from 12 fertile sperm-bank donors

AIM

To extend the analysis of the proteome of human spermatozoa and establish a 2-D gel electrophoresis (2-DE) reference map of human spermatozoal proteins in a pH range of 3.5-9.0.

METHODS

In order to reveal more protein spots, immobilized pH gradient strips (24 cm) of broad range of pH 3-10 and the narrower range of pH 6-9, as well as different overlapping narrow range pH immobilized pH gradient (IPG) strips, including 3.5-4.5, 4.0-5.0, 4.5-5.5, 5.0-6.0 and 5.5-6.7, were used. After 2-DE, several visually identical spots between the different pH range 2-D gel pairs were cut from the gels and confirmed by mass spectrometry and used as landmarks for computer analysis.

RESULTS

The 2-D reference map with pH value from 3.5 to 9.0 was synthesized by using the ImageMaster analysis software. The overlapping spots were excluded, so that every spot was counted only once. A total of 3872 different protein spots were identified from the reference map, an approximately 3-fold increase compared to the broad range pH 3-10 IPG strip (1306 spots).

CONCLUSION

The present 2-D pattern is a high resolution 2-D reference map for human fertile spermatozoal protein spots. A comprehensive knowledge of the protein composition of human spermatozoa is very meaningful in studying dysregulation of male fertility.

Molecular cloning and primary functional analysis of a novel human testis-specific gene

In this study, a new data mining tool called Digital Differential Display (DDD) from the NCBI was used to predict testis-specific expressed genes from the expressed sequence tag (EST) database. DDD (digital differential display) was performed between nine testis libraries and seventy libraries derived from other tissues. We identified a new contig of ESTs (HS. 326528) which was from testis libraries. To validate the use of bioinformatic approaches in gene discovery, the ESTs (HS. 326528), which were predicted to be testis-specific, were chosen for further study. Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) analysis of matched sets of cDNAs from testis and other tissues indicated that the ESTs were specifically expressed in testis. This result was further validated by multi-tissue Northern blot. The full-length cDNA encompassing the entire open reading frame was cloned and, in view of its apparent specificity to testis, the gene was termed homo sapiens spermatogenesis-related gene 8---SRG8 (GenBank accession number: AY489187). The gene whose full cDNA length is 1 044 bp containing 3 exons and 2 introns is located in human chromosome 15q26.2, the cDNA encodes a novel protein of 105 amino acides with a theoretical molecular weight of 11.7 kD and isoelectric point of 10.09 which shares no significant homology with any known proteins in database. Real time PCR analysis of testis of different developmental periods revealed that SRG8 gene is significantly expressed in adult testis. The green fluorescent protein produced by pEGFP-C3/SRG8 was detected in the nucleus of HeLa cells after 24 h post-transfection. Cell cycle analysis showed that SRG8 can accelerate HeLa cells to traverse the S-phase and enter the G2-phase compared with the control without transfection of SRG8, which suggested that this gene plays an important role in the development of testis. The discovery of SRG8 showed that DDD combined with experiments is a feasible, time-saving strategy to identify new candidate genes for testis-specific development

[Cloning of cDNA of TSARG4, a human spermatogenesis related gene]

To understand molecular mechanism of spermatogenesis, two ESTs BG720564 and AI700454, were found from SPAG4 (sperm antigen 4), a gene related to dense fiber protein of outer membrane of the human sperm and mouse spermatocytes gene AK006225. The gap was filled by polymerase chain reaction, and a 1252 bp fragment was obtained. This 1252 bp fragment was named TSARG4 (testis and spermatogenesis related gene 4 (GenBank accession number AF401350). Its opening reading frame was 94-1233 bp, as was proved by RT-PCR in human testis. TSARG4 gene was located in 20q11.2, and the putative protein was 379 amino acid with a theoretical molecular weight of 43 081 and isoelectric point of 8.61. The homologies of amino acid sequences were 74% between TSARG4 and AK006225 gene and 45% between TSARG4 and SPAG4 gene, respectively. The human TSARG4 mRNA is expressed in a wide range of adult tissues, including testis, whereas the homologous mouse spermatocytes gene AK006225 is expressed specifically in the testis.

[Establishment of the data base of large human sperm bank and its application]

On the basis of Access 97, we set up the first computer management system for human sperm bank in China, which dealt with various information and data of sperm bank and of treatment for AID(artificial insemination donor) patients. The system and its application, characteristics and significance were discussed in this article.

A novel sensitive method to detect frameshift mutations in exonic repeat sequences of cancer-related genes

We have investigated frameshift mutations in exonic repeats in the ATR, BRCA1, BRCA2, PTCH, CTCF, Cx26, NuMa and TGFbetaRII genes, using human tumor samples from stomach, esophagus, breast and skin and melanoma, as well as colon cancer and endometrial cancer cell lines (125 samples in total). We developed a sensitive method to detect mutations in the repeats, using the introduction of an artificial restriction site into a repeat. The method detects a single mutant among 10(3) normal genes. Thus, an alteration in a repeated sequence can be detected unambiguously. The (A)(8) repeat of BRCA2 was found mutated in only two of five colon cell lines with microsatellite instability (MI(+)). The ATR gene has an (A)(10) repeat which was altered in two of three MI(+) stomach cancer samples and one of three MI(+) endometrial cell lines. The TGFbetaRII gene [with an (A)(10) repeat] had the maximal frequency of mutations: 10 out of 13 MI(+) samples. At least one sample from all types of cancers, except melanomas, was positive for TGFbetaRII gene mutations. No mutations were found in repeats in the BRCA1, PTCH, CTCF, NuMA and Cx26 genes in any types of tumors examined. In conclusion, our study indicates that repeats were altered only in MI(+) cells and that the mutation frequencies in the genes studied differ among tumor types. Based on these results, we discuss meaningful and meaningless alterations in exonic repeats.

An asymptotic solution for the contact of two biphasic cartilage layers

This study addresses the hypothesis that interstitial fluid plays a major role in the load support mechanism of articular cartilage. An asymptotic solution is presented for two contacting biphasic cartilage layers under compression. This solution is valid for identical thin (i.e. epsilon = h'/a'0 << 1), frictionless cartilage layers, and for the 'early' time response (i.e. t' << (h')2/HAk) after the application of a step load. An equilibrium asymptotic solution is also presented (i.e.t'-->infinity). Here h' is the thickness, a'0 is a characteristic contact radius, HA is the aggregate modulus and k is the permeability of the cartilage layer. A main conclusion from this analysis is that the fluid phase of cartilage plays a major role in providing load support during the first 100-200 s after contact loading. Further, the largest component of stress in cartilage is the hydrostatic pressure developed in the interstitial fluid. For tissue fluid volume fraction (porosity) in the range 0.6 < or = phi f < or = 0.8, k = O(10(-15) m4/Ns) and HA = O(1 MPa), the peak magnitude of the principal effective (or elastic) stress may be as low as 14% of the peak hydrostatic pressure within the tissue, or the contact stress at the surface. In effect, the interstitial fluid shields the solid matrix from high normal stresses and strains. The asymptotic solution also shows that pressure-sensitive film measurements of intra-articular contact stress do not measure the elastic stress at the surface, but they rather provide a measure of the interstitial fluid pressure. Finally, this analysis provides strong support for the hypothesis that, if sudden loading causes shear failure within the cartilage-bone layer structure, this failure would take place at the cartilage-bone interface, and the plane of failure would be either parallel or perpendicular to this interface.

Biphasic indentation of articular cartilage--II. A numerical algorithm and an experimental study

Part I (Mak et al., 1987, J. Biomechanics 20, 703-714) presented the theoretical solutions for the biphasic indentation of articular cartilage under creep and stress-relaxation conditions. In this study, using the creep solution, we developed an efficient numerical algorithm to compute all three material coefficients of cartilage in situ on the joint surface from the indentation creep experiment. With this method we determined the average values of the aggregate modulus. Poisson's ratio and permeability for young bovine femoral condylar cartilage in situ to be HA = 0.90 MPa, vs = 0.39 and k = 0.44 x 10(-15) m4/Ns respectively, and those for patellar groove cartilage to be HA = 0.47 MPa, vs = 0.24, k = 1.42 x 10(-15) m4/Ns. One surprising finding from this study is that the in situ Poisson's ratio of cartilage (0.13-0.45) may be much less than those determined from measurements performed on excised osteochondral plugs (0.40-0.49) reported in the literature. We also found the permeability of patellar groove cartilage to be several times higher than femoral condyle cartilage. These findings may have important implications on understanding the functional behavior of cartilage in situ and on methods used to determine the elastic moduli of cartilage using the indentation experiments.