BACKGROUND:Because of the special and complicated biological characteristics of oocytes, the suitable cyropreservation technology for oocytes faces more various chalenges. However, the uneven survival rate and fertilization, damages of developmental potential of the thawed oocyte stil exist. OBJECTIVE:To introduce the progress in basic and application researches of oocyte cryopreservation technology, and to iluminate the technical defects and thoughts and possible research points to overcome these problems. METHODS: A computer-based search of CNKI and PubMed was performed for articles concerning oocyte cryopreservation from January 2004 to October 2014. The search terms were oocyte, cryopreservation, vitrification in Chinese and English, respectively. The old and repeated articles were excluded. Finaly, 41 articles were included in result analysis. RESULTS AND CONCLUSION:The cryopreservation of oocytes by slow freezing and vitrification has been used in clinic. At the same time, the uneven survival and fertilization rate, damaged developmental potential of the thawed oocyte stil puzzle the clinicians. The key point to breakthrough or improvement of oocyte cryopreservation technology is the systematization of the protocol for oocylte cryopreservation, for example, the choice of cryoprotective agents, the development of carriers for oocytes, and the determination of oocyte stage. Furthermore, other related technologies should also be considered, including thein vitro mature technology of oocytes, cryopreservation and transplantation of ovary tissues.

Objective To investigate drug resistance mechanism of aminoglycoside-resistant Acinetobacter baumannii by detecting 16S rRNA methylase gene and three common genes of aminoglycoside-modifying enzymes in Acinetobacter baumannii infected patients at EICU. Methods The 48 Acinetobacter baumannii strains were collected,and antimicrobial susceptibility tests were performed by VITEK automicroscan. The MIC was detected by 2-fold agar dilution method,and genes were analyzed by polymerase chain reaction( PCR) . Results Among 48 strains,28 were highly resistant to aminoglycosides and 20 showed lower resistances. The 16S rRNA armA,APH(3')-I,ANT(3'')-Ia,AAC(6')-Ib genes were detected in 71. 43%,60. 71%,82. 14%, and 53. 57%of the 28 highly resistant strains,but only present in 0. 00%,0. 05%,0. 05%,and 0. 05%of the low-resistant isolates(P<0. 01). Conclusion The aminoglycoside-modifying enzymes and 16S rRNA methylase were frequently found in Acinetobacter baumannii clinical isolates,which is closely related to the high-level resistance to aminoglycoside antibiotics.

Objective To knock out p21 gene in human malignant rhab doid tumor(MRT)cell line G401 by using CRISPR/Cas9 genome engineering technology. Methods The expression of p21 was detected by reverse transcription quantitative PCR (RT-qPCR) and Western blot assay in several MRT cell lines. The guide RNA was designed by targeting the third exon of p21 gene,which encoded its home domains, and then subcloned into lentiCRISPR v2 vector and validated sequencing. The validated plasmids were further used to package and produce the lentivirus in 293T cells, and the G401 cells were infected, then puromycin was used to screen positive cells, and the clusters of G401 monoclonal cells, were obtained by selecting monoclonal cells and culturing under the microscope. The RNA and protein of new clonal cell line were extracted, and RT-qPCR and Western blot assay were applied to confirm whether p21 was successfully knocked out. Results The p21 was highly expressed in MRT tumor cells. The CRISPR/Cas9 lentivirus plasmids, targeted p21 gene were successfully constructed. Compared with negative control group,the expression of p21 was not detected in G401 monoclonal cells, which were successfully screened. Conclusion In view of the difficult transfection of cells such as G401, p21 knockout stable cell line has been successfully constructed by using CRISPR/Cas9 system, which lays the foundation for further study of the mechanism of p21 in MRT tumors .

Objective:To analyze the cause of varicocele (VC) recurrence and investigate the efficacy of sub-inguinal microsurgical varicocelectomy (MV) for recurrent VC.Methods:All of 16 inpatients diagnosed as recurrent VC, in the Department of Andrology of the Affiliated Hospital of Qingdao University from 2015 April to 2019 April, were performed sub-inguinal MV. The age of the inpatients was 18-36 years old, median 27 years old.5 cases were originally performed retroperitoneal high ligation of spermatic vein and other 11 cases were originally performed laparoscopic varicocelectomy. During the review one to three years after the previous operation, all of 16 patients were diagnosed as VC recurrence. The complains of these patients during the review included male subfertility (10 cases) and scrotal pain (12 cases), in which 6 cases’ complains were male subfertility with scrotal pain. After admission, 13 patients were classified as Grade Ⅲ (left in 8 cases, bilateral in 5 cases) and 3 patients as Grade Ⅱ (all left). The median of their visual analogue scale (VAS) was 2.5. Color doppler flow imaging (CDFI) grading showed: Grade Ⅲ in 12 cases (left in 7 cases, bilateral in 5 cases), Grade Ⅱ in 4 cases (all left). Particularly, 12 of them were Graded as Ⅲ simultaneously accompanying with Nut-cracker Phenomenon (NCP). Preoperative tests showed that the average serum testosterone was (16.2±4.9)nmol/ml, the average sperm concentration was (11.8±3.9)×10 6/ml and the progressive motility rate (PR) was (24.4±4.2)%. All of the patients were performed sub-inguinal MV using general anesthesia and supine position. The spermatic cords were clearly exposed and padded up by inserting gauze strips under them. During the operation, the field was magnified 4-6 times with the microscope. Then all of the dilated external and internal spermatic veins were ligated, at the same time the internal spermatic artery and lymph vessels were well preserved. During these operations, 11 patients underwent left-side MV, while other 5 did bilateral MVs. During these MVs, we found twisted and dilated external and internal spermatic veins in all cases and well preserved the internal spermatic arteries and lymph vessels. The number of ligated left and right external spermatic veins were(2.1±0.6) and (1.4±0.5)respectively and the number of ligated left and right internal spermatic veins were (10.1±1.1) and (6.6±0.5) respectively. We also found out(1.3±0.5) internal spermatic arteries and (3.0±1.0)lymph-vessels on left side. On right side, there were (1.4±0.5) internal spermatic arteries and (2.6±0.5) lymph-vessels respectively. At last, we summarily analyzed the pre-operative and post-operative VAS, serum testosterone, CDFI and semen analysis data. Results:All of the 16 sub-inguinal MVs were successfully performed. All patients were reviewed comprehensively 6 months after MV. The reviewed results showed that the post-operative VAS was significantly reduced ( Z=-2.994, P<0.05), palpable scrotal vessels disappeared and Valsalva tests were negative. No obvious reflux of internal spermatic veins were detected by CDFI. Interestingly, the sperm concentration and motility were both significantly improved 6 months after MV ( P<0.05), while there was not remarkable increase of the serum testosterone after MV ( P>0.05). During the follow up, no testicular atrophy, hydrocele and other complications were found. Up to submission, five of the ten patients who presented for male subfertility have impregnated their wives. Conclusions:The most possible cause of VC recurrence could be the omission of the external and internal spermatic veins, particularly in the grade Ⅲ VC patients or VC accompanied with NCP. The sub-inguinal MV, which can discover more twisted spermatic veins and at the same time preserve the spermatic artery and lymph-vessels, shows better clinical efficacy than other procedures.

Neurofibromas are benign tumors of the peripheral nerve sheath originated from mesenchymal tissue and can occur throughout the body, but rarely in the testis. The preferred imaging method is ultrasound. The contrast-enhanced ultrasound can assist in showing the lesions. The characteristic pathological changes are positive of S100 and SOX10 with immunohistochemical staining. It is recommended to choose organ-sparing surgery because of the good prognosis.