The Role of MOOC in Biochemistry Teaching: Teaching Practice and Summary of “MOOC + Online Meet Course” in Biochemistry of South China Agricultural University / 中国生物化学与分子生物学报

Biochemistry is not only a basic course for biology majors, but also one of the fastest growing frontier courses. Facing the complicated system of biochemistry, the traditional teaching mode exposes many problems, and the teaching effect is not good. With the development of Internet technology, " Internet +" education has developed rapidly. Online courses such as MOOCs and micro-courses provide many colleges and universities with rich learning resources. Online courses such as Dingding Classroom, Tengxun Classroom, Rain Classroom, and WeChat exchange platform also allow students to achieve synchronous learning conveniently. Online teaching has become the main teaching mode of colleges and universities across the country during the COVID-19 epidemic. However, after several years of promotion, pure online teaching has also exposed many problems in terms of teaching effect. In order to give full play to the respective advantages of online and offline teaching, blended teaching has become a new direction. South China Agricultural University began to cooperate with Wisdom Tree Platform in early 2019 to establish the MOOC of biochemistry. During the COVID-19 outbreak in 2020, the online mixed teaching mode of “MOOC + online meet course” is used in teaching. Teaching feedback results showed that "MOOC + online meet course" can be more generally recognized by students than relying solely on MOOC learning. This teaching mode improves students′ learning interest and initiative, improves teaching quality and learning effect, and provides a reference for the application of "MOOC + offline course" in the future.

Genetic analysis of three cases of acephalic spermatozoa syndrome caused by SUN5 mutation and the outcome of assisted reproductive technology / 北京大学学报(医学版)

To explore the genetic causes of 3 male infertility patients with acephalospermia and the outcome of assisted reproductive technology. Clinical diagnosis, sperm morphology examination, sperm transmission electron microscopy examination were performed on 3 patients, and the whole exome sequencing technology was used for screening, Sanger sequencing verification, mutation pathogenicity analysis, and protein sequence homology comparison. Assisted reproductive technology was implemented to assist pregnancy treatment. The 3 patients were all sporadic infertile men, aged 25, 42 and 26 years, and there was no obvious abnormality in the general physical examination. Male external genitalia developed normally, bilateral testicles were normal in volume, and bilateral epididymis and spermatic vein were palpated without nodules, cysts, and tenderness. Repeated semen analysis showed that a large number of immature sperm could be seen, and they had the ability to move. The SUN5 gene of the 3 male infertile patients was a case of homozygous missense mutation c.7C>T (p.Arg3Trp), a case of compound heterozygous missense mutation c.1067G>A (p.Arg356His) and nonsense mutation c.216G>A (p.Trp72*) and a case of homozygous missense mutation c.1043A>T (p.Asn348Ile), of which c.7C>T (p.Arg3Trp) and c.1067G>A (p.Arg356His) were new variants that had not been reported. SIFT, Mutation Taster and PolyPhen-2 software function prediction results were all harmful, the nonsense mutation c.216G>A (p.Trp72*) led to the premature termination of peptide chain synthesis which might have a greater impact on protein function. The homology regions in the protein sequence homology alignment were all highly conserved.The 3 male patients and their spouses obtained 4 biological offspring through intracytoplasmic sperm injection, all of which were boys, and one of them was a twin.Three male infertile patients might be caused by SUN5 gene mutations. Such patients could obtain their biological offspring through assisted reproductive technology. It was still necessary to pay attention to the genetic risk of ASS, it was recommended that both men and women conduct genetic counseling and screening at the same time. In clinical diagnosis, whole exome sequencing technology could be used to perform auxiliary examinations to determine the treatment plan and assisted reproductive methods as soon as possible to reduce the burden on the family and society. The newly discovered mutation sites of SUN5 gene provided clues and directions for elucidating the pathogenic mechanism, and at the same time expanded the pathogenic mutation spectrum of ASS.

Outcomes of ICSI with sperm from different sources: a retrospective study of 431 cycles / 中华男科学杂志

<p><b>OBJECTIVE</b>To compare the outcomes of intracytoplasmic sperm injection (ICSI) with retrieved epididymal and testicular sperm for obstructive azoospermia and with ejaculated sperm for severe oligozoospermia and asthenospermia.</p><p><b>METHODS</b>We retrospectively analyzed 431 ICSI cycles, which were divided according to sperm sources into Groups A (n=287 in patients with severe oligozoospermia or asthenospermia using ejaculated sperm), B (n=109 in obstructive azoospermia patients with sperm retrieved by percutaneous epididymal sperm aspiration, PESA) and C (n=35 in obstructive azoospermia patients with sperm retrieved by testicular sperm extraction, TESE). Comparisons were made among the three groups in the rates of embryo implantation, fertilization, pregnancy, cleavage, and miscarriage.</p><p><b>RESULTS</b>Group A showed statistically significant differences from Groups B and C in the rates of embryo implantation and pregnancy (18.46% vs. 25.23% and 28.76%, 31.23% vs. 42.16% and 39.39%, P < 0.05). But no significant differences were seen in the rates of fertilization, cleavage and miscarriage among the three groups (P > 0.05).</p><p><b>CONCLUSION</b>The rates of embryo implantation and clinical pregnancy are higher in patients with obstructive azoospermia than in those with severe oligozoospermia or asthenospermia after ICSI with ejaculated sperm.</p>

The culture and identification of rat testis Leydig cell / 中华男科学杂志

<p><b>OBJECTIVE</b>To establish a primary culture method of rat testis Leydig cell.</p><p><b>METHODS</b>The primary rat Leydig cells were treated with or without 4 U/ml human chorionic gonadotropin (hCG), and testosterone in culture medium was detected by radioimmunoassay. The morphology and biological characteristics of Leydig cell were observed.</p><p><b>RESULTS</b>The culture cells were highly homogeneous, proliferative and had a high differentiation rate. The high purified Leydig cells were verified by their dynamic morphological changes and 3beta-hydroxysteroid dehydrogenase delta4-delta5 isomerase (3beta-HSD) histochemical staining. The testosterone secretion induced by hCG significantly increased (P < 0.05) 24 hours after inoculation than that induced without hCG in the control.</p><p><b>CONCLUSION</b>It suggests that the Leydig cell cultured in vitro may secrete high concentration of testosterone, and this study laid the basis of androgen replacement therapy for partial androgen deficiency in aging male.</p>

Experimental study of changes in microscopic characteristics and ability of secreting testosterone of aged SD rat leydig cells / 中华男科学杂志

<p><b>OBJECTIVE</b>To research the changes in microscopic characteristics and ability of secreting testosterone between aged SD rat Leydig cells and young SD rat Leydig cells.</p><p><b>METHODS</b>The total and free serum testosterone levels of serum both young and aged rats were examined. The changes in microscopic characteristics between young and aged rat Leydig cells were observed under microscope and electron microscope. The testosterone secreted by cultured Leydig cells of stimulated by hCG and Forskolin both groups were detected.</p><p><b>RESULTS</b>A significant difference was found in both total and free testosterone levels between young and old rats (P < 0.05). Aged SD rat Leydig cells were observed smaller in volume and more markedly stained than young ones; The secretion ability of aged rat Leydig cells was found lower than that of young rat Leydig cells with or without hCG and Forskolin stimulation (P < 0.05).</p><p><b>CONCLUSION</b>The secreting index of aged SD rat Leydig cells is lower than that of young rat Leydig cells both in vivo and vitro, and the reason is the system of synthesizing testosterone is arrested.</p>

Culture and identification of human adult Leydig cells / 中华男科学杂志

<p><b>OBJECTIVE</b>To obtain a simple and effective method to isolate and purify adult Leydig cells.</p><p><b>METHODS</b>The testes of human adults were digested and then the density gradient centrifugation of the cells was performed with four different Percoll concentrations (60%, 34%, 26%, 21%) to isolate Leydig cells, whose characteristics were identified by cytological observation staining, 3beta-HSD staining and detection of hCG and testosterone secretion.</p><p><b>RESULTS</b>High-concentration (> 90%) purified Leydig cells were acquired, and many identification experiments demonstrated the adequate testosterone secretory function of the isolated and purified Leydig cells.</p><p><b>CONCLUSION</b>This method is easy and efficient for the isolation and purification of adult Leydig cells.</p>

Measures for optimizing the efficacy of sildenafil on patients with erectile dysfunction / 中华男科学杂志

Incorrect drug administration, lack of sexual stimulation, the way of obtaining sildenafil and associating risk factors of erectile dysfunction like severe cardiovascular or neurogenic diseases were the common causes of initial sidenafil failure. To improve the therapeutic efficacy for patients with initial sidenafil failure, education about how to use sildenafil properly plays an important role. Moreover, dose titration, more attempts, a good follow-up and sildenafil taking on a daily basis will yield a high response rate to sildenafil rechallenge.

Surgical therapy for azoospermia with ejaculatory duct obstruction / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of transurethral resection of ejaculatory ducts (TURED) for azoospermia with ejaculatory duct obstruction (EDO).</p><p><b>METHODS</b>From June 2003 to December 2004, 20 azoospermia with EDO were diagnosed, diagnostic criteria included a history, physical examination, semen analyses, semen fructose measurement, endocrine assessment, testicular biopsy and transrectal ultrasonography (TRUS); All 20 cases were treated by TURED. Fifteen of them were followed up more than 3 months after the treatment. The semen samples of them were analysed at 3-month intervals in post-therapy.</p><p><b>RESULTS</b>Semen analyses in all 20 cases showed the typical characteristics of EDO, low semen volume (0.4-1.6 ml), azoospermia, low pH, absent or low semen fructose. TRUS showed the main etiology factor of EDO was a midline cyst in 11, lateral cystic lesions in 2, the remaining 7 cases had dilated ejaculatory duct with or without dilated seminal vesicles. Among 15 cases followed up more than 3 months after TURED, 10/15 (67%) had an improvement in semen parameters and 3/15 (20%) had pregnancies. Semen analyses had not been done in anther 5 cases.</p><p><b>CONCLUSION</b>Transurethral resection of ejaculatory ducts may be a safe and effective method for the treatment of azoospermia with EDO.</p>