A retrospective study on sperm cryopreservation in 1034 patients diagnosed with cancer in southern China.

Sperm cryopreservation is an effective fertility preservation method for cancer patients before anticancer treatments. However, there are little data on fertility preservation in large cohorts of patients with cancer in southern China. This retrospective cross-sectional study aimed to assess the fertility preservation status of 1034 newly diagnosed male patients with cancer in the Human Sperm Bank of Guangdong Province in southern China (Guangzhou, China). Of these, 302 patients had reproductive system tumors, mostly testicular cancers (99.0%), and 732 had other tumors, including lymphoma (33.1%), gastrointestinal cancer (16.3%), nasopharyngeal carcinoma (15.7%), leukemia (7.7%), sarcoma (3.6%), and others (23.6%). Patients with reproductive system tumors had lower sperm concentration and prefreezing and post-thawing progressive motility than those with non-reproductive system tumors (all P < 0.001). Differences in sperm concentration, progressive motility, and normal morphology rate were observed between patients with and without anticancer surgery before sperm cryopreservation (all P < 0.05). As of April 30, 2022, 63 patients used their cryopreserved sperm for assisted reproductive technology treatments and 39 pregnancies were achieved. This study provides valuable data on the fertility preservation status in newly diagnosed cancer patients in southern China, demonstrating that patients with reproductive system tumors had poor sperm quality for their pretreatment fertility preservation.

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.

[Role of full-time nurses in reception of sperm donors in the sperm bank].

OBJECTIVE: To explore the necessity of reception of sperm donors by full-time nurses in the sperm bank by analyzing the efficiency of sperm donation before and after staffing Guangdong Sperm Bank (GSB) with full-time nurses. METHODS: We selected 9 712 qualified sperm donors in GSB from January 1, 2016 to December 31, 2021 and compared the efficiency of sperm donation before and after staffing GSB with full-time nurses. RESULTS: After staffing GSB with full-time nurses, the proportion of qualified sperm donors screened from the quasi-qualified ones was dramatically increased from 66.2% (1 230/1 858) to 77.1% (3 252/4 218) (P < 0.01), that of HIV re-examinees after 6-month suspension from sperm donation increased from 84.6% (137/162) to 93.4% (599/641) (P < 0.01), and that of the candidate donors lost to follow-up during the screening period decreased from 23.2% (831/3 583) to 21.3% (1 308/6 129) (P = 0.034). CONCLUSION: After Guangdong Sperm Bank was staffed with full-time nurses for reception of sperm donors, the proportion of the candidate donors lost to follow-up was reduced and the efficiency of sperm donation was significantly improved. Individualized psychological intervention for the sperm donors by the nurses could dispel the worries of the donors and improve the compliance and efficiency of sperm donation.

[Causes of failure in autologous sperm preservation in the human sperm bank and countermeasures].

OBJECTIVE: To analyze the causes of failure in autologous sperm cryopreservation (ASCP) in the human sperm bank and propose some countermeasures to improve the success rate of ASCP and promote it in human sperm banks. METHODS: We retrospectively analyzed the reasons for and causes of failure in ASCP 1 156 males undergoing ASCP in the Human Sperm Bank of Guangdong Province from January 1, 2016 to December 31, 2019. RESULTS: Of the 1 156 cases of ASCP, 857 (74.1%) succeeded and 299 (25.9%) failed, with a failure rate of 56.1% (96/171) in the microdissection testicular sperm extraction (micro-TESE) group, 29.9% (67/224) in the reproduction insurance group, 21.2% (27/100) in the non-tumor disease group and 17.2% (109/525) in the tumor group, with statistically significant difference between the four groups (χ2 = 109.926, P < 0.01). The causes of failed ASCP included failure to extract semen (14.0% ï¼»42/299ï¼½), failure to meet the standard of sperm cryopreservation (67.6% ï¼»202/299ï¼½), giving up ASCP for low semen quality (7.4% ï¼»22/299ï¼½), and giving up ASCP for some other reasons (11.0% ï¼»33/299ï¼½), including worry about the reliability of cryopreservation technology (6.0% ï¼»18/299ï¼½), suspicion about the complexity of the ASCP procedures (3.0% ï¼»9/299ï¼½) and expectation for fertility recovery after chemotherapy withdrawal (2.0% ï¼»6/299ï¼½). CONCLUSIONS: In view of different causes of failure in ASCP, human sperm banks can provide individualized cryopreservation schemes, including guidance with masturbation or the use of sperm extraction instrument in sperm extraction, strengthening sperm preservation-related education and the awareness of reproduction protection and earlier sperm preservation among cancer patients, promoting the cryopreservation of microsamples of motile sperm by microsample or single sperm freezing, and development of testis tissue cryopreservation to preserve the fertility of children with cancer.

High-level expression and characterization of a thermostable xylanase mutant from Trichoderma reesei in Pichia pastoris.

A gene encoding xylanase 2 mutant from Trichoderma reesei (T2C/T28C, named mxyn2) was cloned into the Pichia pastoris X33 strain using the vector pPICZαA. Recombinant Mxyn2p was functionally expressed in P. pastoris X33 and secreted into the supernatant. Real time qPCR demonstrated that an increase in gene copy number correlated with higher levels of expression. Supernatant from methanol induced cells was concentrated by ultrafiltration with a 10kDa cut off membrane, and purified with ion exchange chromatography using SP Sepharose Fast Flow chromatography. Recombinant Mxyn2p protein had the highest activity at 75°C, while recombinant protein encoded by the "wild type" xylanase gene xyn2, also expressed in Pichia, was 20°C lower. The Mxyn2p enzyme retained more than 70% of its activity after incubation at 80°C for 10min. The effects of the optimal pH and temperature for higher expression levels in P. pastoris were also determined, 6.0 and 22°C, respectively. The maximum xylanase activity of Mxyn2p was 13,000nkat/mg (9.88g/l) in fed-batch cultivation after 168h induction with methanol in a 50l bioreactor.