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Biomedical subjects

H C Wei

Publications and source records attributed to H C Wei.

8 recordsLinked to original sources

Use of intraoperative ultrasonography during hepatolithectomy.

Complete clearance of intrahepatic stones has long been a major surgical challenge. To reduce the incidence of residual stones, we used intraoperative ultrasonography (IOUS) to localize them and guide lithectomy in 38 patients with hepatolithiasis between July 1988 and December 1993. All patients had multiple intrahepatic stones; 24 had accompanying extrahepatic calculi. Hepatic stones were confined to the left intrahepatic biliary tract in 13 patients, to the right in 9, and in both lobes in 16. Twenty-three patients underwent common bile duct exploration followed by T-tube drainage, 8 had transhepatic lithotomy with or without choledocholithotomy, 3 had choledocolithotomy and Roux-en-Y side-to-side choledochojejunostomy, and 2 had hepaticojejunostomy, left lobectomy was performed in the remainder. In 35 patients cholecystectomy was performed at the same time. Complete clearance of the stones was achieved in 36 patients (94.7%). The incidence of retained stone was decreased to 5.3%. No associated complications occurred. IOUS can accurately localize intrahepatic calculi, directly orient lithotomy instruments to approach the stones, demonstrate the spatial relation between stone and intrahepatic critical structure, and thereby choose an optical route for transhepatic lithotomy. Imaging can be repeated at any time with no radiation exposure to the patient or the medical staff.

Adult↗

Quantitative high-performance liquid chromatography analysis of DNA oxidized in vitro and in vivo.

Oxidative modification of genetic material has been implicated as a factor in carcinogenesis, particularly during promotion and progression, and therefore there is a need for sensitive detection of oxidized DNA bases. We developed a method that can be applied to DNA isolated from any source and used to simultaneously quantify oxidized nucleosides without a need to prelabel the DNA or use destructive hydrolytic procedures. This method is based on: (a) enzymatic DNA digestion; (b) HPLC separation of the resultant nucleosides; (c) acetylation of the oxidized nucleosides with [3H]Ac2O (acetic anhydride); (d) removal of the radioactive debris; and (e) quantitative analysis of tritiated nucleoside acetates by HPLC. Enzymatic DNA digestion was optimized using DNase I in the presence of Mg2+ (pH 7), followed by nuclease P1 in the presence of Zn2+ (pH 5.1) and alkaline phosphatase (pH 7.5). Analysis of DNA oxidized with H2O2 in the presence of Fe2+/EDTA for 30 min showed that the levels of 8-OHdG (8-hydroxy-2'-deoxyguanosine) were increased 2.7-fold, HMdU (5-hydroxymethyl-2'-deoxyuridine) 3.15-fold, and FdU (5-formyl-2'-deoxyuridine) 2.5-fold. Although the (-)-isomer of cis-dTG (cis-thymidine glycol) was enhanced 2.3 times, the (+)-isomer remained virtually unchanged. Analysis of DNA isolated from epidermal cells of mice treated in vivo with the tumor promoter TPA (12-O-tetradecanoylphorbol 13-acetate) showed 4.8-, 2.7-, and 8.7-fold increases in the levels of total cis-dTG, 8-OHdG, and HMdU, respectively, and of some unknown DNA oxidation products. These results prove applicability of the 3H-postlabeling method to the analysis of DNA (and potentially RNA) isolated from many sources, including animals and humans.

Animals↗

Treatment of bilateral intrahepatic stones with high duct strictures through selective central hepatic resection.

Bilateral intrahepatic duct stones with strictures, more common in the Orient than elsewhere, are difficult to access surgically. The results of surgical procedures have not been generally successful and are attended by a high postoperative complication and recurrence rate. We report the treatment of 30 patients with intrahepatic calculi and high duct strictures by means of selective central hepatic resection without dissection of the major vessels at the hilum. Central hepatic resection provided satisfactory access to the primary and secondary confluences of the intrahepatic ducts, allowed removal of residual stones and ascariasis, and permitted correction of multiple strictures. Twenty-nine patients so treated were followed for a mean of 32 months after operation. No patients developed recurrent fever, biliary colic, or jaundice after the operation. The technique is therefore recommended as an effective alternative to extensive hepatic lobectomy in the treatment of the intrahepatic calculi with multiple strictures.

Adult↗

[Correlation between selenium levels in the human body and lung cancer. II. Multi-statistical analysis of the correlation between selenium levels in the blood, hair, lung and lung cancer].

18 factors, including possible lung cancer-causing factors and body selenium (Se) levels, were analyzed by computer-based multiple stepwise regression and main component analysis. 1. The results indicated that Se levels in blood, hair and lung had correlation with lung cancer to some extent. 2. The correlation of blood and lung Se was the most significant one, the significance of which was only second to age and smoking habits. The standardized regression and factor load coefficients showed a negative correlation with blood Se level and a positive one with lung Se level, which corresponded with the results obtained by the single factor analysis.

Factor Analysis, Statistical↗