The role of human lysozyme-like protein 4 in fertilization and its enzymatic properties / 中华男科学杂志

Objective@#To elucidate the possible role of human lysozyme-like protein 4 (LYZL4) in fertilization and characterize its enzymatic properties.@*METHODS@#The localization of LYZL4 in human spermatozoa was investigated by immunofluorescence staining, the sources of LYZL4 on the sperm surface examined by RT-PCR, and the role of LYZL4 in fertilization assessed by the zona-free hamster egg penetration test. The recombinant plasmid pPIC9K-LYZL4 was constructed and its expression induced with methanol after transformed into competent Pichia pastoris GS115. The recombinant LYZL4 protein (rLYZL4) was purified from the fermentation supernatant and subsequently identified by Western blot. The hyaluronan binding ability of rLYZL4 was determined by ELISA and the muramidase activity, hyaluronidase activity, and free radical scavenging ability examined by spectrophotometric methods.@*RESULTS@#Immunodetection with a specific antiserum localized LYZL4 on the acrosomal membrane of mature spermatozoa, which was exclusively secreted from the testis and epididymis as shown by RT-PCR. Immunoneutralization of LYZL4 significantly decreased the number of human spermatozoa bound to zona-free hamster eggs in a dose-dependent manner in vitro. The recombinant protein was expressed successfully by the P. pastoris strain GS115. Purified rLYZL4 exhibited a potent hyaluronan binding ability and a strong free radical scavenging ability but no muramidase or hyaluronidase activity.@*CONCLUSIONS@#LYZL4 secreted from the testis and epididymis is localized on the acrosomal membrane of mature spermatozoa and plays a role in sperm-egg binding as well as in binding hyaluronan and scavenging free radicals, which suggests that it might be a multi-functional molecule contributive to sperm protection and sperm-egg binding.

Management of polypoid lesions of the gallbladder: an analysis of 748 patients / 中华肝胆外科杂志

Objective To investigate the risk factors of gallbladder neoplastic polyps,to determine the proper surgical indications,and to understand more about the clinical characteristics of gallbladder adenoma.Methods The clinical data of 748 patients diagnosed to have polypoid lesion of gallbladder (PLG) and underwent cholecystectomy from January 1998 to December 2012 in the Second Affiliated Hospital of Zhejiang University School of Medicine were retrospectively reviewed.Results Among 748 patients,340 had abdominal symptoms.Postoperative histopathology showed non-neoplastic polyps (n =659),gallbladder adenoma (n =68),gallbladder cancer (n =15) and no polyps (n =6).The mean diameters of the nonneoplastic lesions and the neoplastic polyps were (9.38 ± 3.44) mm and (14.55 ± 5.71) mm,respectively (P ＜ 0.01).The average age of the patients with non-neoplastic lesions was (44.14 ± 11.42) years and (47.39 ± 12.82) years in those with neoplastic polyps (P ＜ 0.05).The proportion of solitary PLG was 41.4％ (253/611) and 59.59％ (47/79) for the non-neoplastic lesions and the neoplastic polyps respec tively (P ＜ 0.01).The size of PLG (13.34 ± 4.18 mm vs.20.07 ± 8.19 mm,P ＜ 0.05) and the age of the patient (45.78 ± 11.66 years vs.54.13 ± 15.82 years,P ＜0.05) between the gallbladder adenoma and gallbladder cancer groups were significantly different.Gallbladder adenoma or dysplasia was identified in 66.7％ (10/15) of gal1bladder cancer specimens.Conclusions Patients with PLG and with abdominal symptoms,large size (≥ 10 mm),old age (≥50 y) and solitary polyp are indications for cholecystectomy.Gallbladder adenoma may develop to gallbladder cancer within 10 years.