Modulation of human telomerase reverse transcriptase in hepatocellular carcinoma

AIM:Most cancer cells acquire immortal capability by telornerase activation. The human telornerase reverse transcriptase gene (hTERT) is considered to be the major determinant of the enzymatic activity of human telomerase,and the hTERTpromoter contains several c-lylyc binding sites that mediate hTERTtranscriptional activation. Few studies have examined the role of hTERTin hepatocarcinogenesis,and the relationship between c-Myc and telomerase in human hepatocellular carcinoma tissue is unknown.METHODS:We measured hTERTmRNA levels and c-Myc oncoprotein expression in 57 patients with hepatocellular carcinoma using in situhybridization and immunohistochemistry,respectively. The transcription regulation of hTERT was evaluated by transient transfection of pGL3-1375 into the human hepatocellular carcinoma cell line J5. To determine the relationship between c-Myc and the hTERTpromoter, a 1375-bp DNA fragment encompassing the promoter was placed upstream of the luciferase reporter gene and transiently transfected into the cell line. Two additional hTERT promoter constructs (-776 and -100 bp region) and an hTERT promoter-LUC construct containing 2 c-Myc mutations (pGL3-181 MycMT) were also used for luciferase assays.RESULTS:In 30 of 57 cases (52%), hTERTmRNA expression was associated with c-Myc protein expression. However,16 of 57 cases (28%) showed strong hTERTmRNA detection without c-Myc protein expression, and 11 cases (19%) showed weak hTERTmRNA expression and strong c-Myc expression.Although luciferase activity was decreased between upstream 1375 bp and 776 bp, there was no significant difference between upstream 776 bp and 100 bp. Finally, there was no significant decrease in activity after transfection of the hTERT promoter-LUC construct.CONCLUSION:The results indicate that c-Myc does not play a major role in gene regulation of the catalytic subunit of telomerase (hTERT) in human hepatocellular carcinoma.Other regulatory elements or epigenetic phenomena should be further investigated to understand hTERTgene regulation in human hepatocellular carcinoma.

Accuracy of indocyanine green pulse spectrophotometry clearance test for liver function prediction in transplanted patients

AIM: To investigate whether the non-invasive real-time Indocynine green (ICG) clearance is a sensitive index of liver viability in patients before, during, and after liver transplantation.METHODS: Thirteen patients were studied, two before,three during, and eight following liver transplantation, with two patients suffering acute rejection. The conventional invasive ICG clearance test and ICG pulse spectrophotometry non-invasive real-time ICG clearance test were performed simultaneously. Using linear regression analysis we tested the correlation between these two methods. The transplantation condition of these patients and serum total bilirubin (T. Bil), alanine aminotransferase (ALT), and platelet count were also evaluated.CONCLUSION: ICG pulse spectrophotometry clearance is a quick, non-invasive, and reliable liver function test in transplantation patients.

Comparison of transcatheter arterial chemoembolization,laparoscopic radiofrequency ablation,and conservative treatment for decompensated cirrhotic patients with hepatocellular carcinoma

AIM:To compare the therapeutic effect of transcatheter arterial chemoembolization （TACE), laparoscopic radiofrequency ablation (LRFA), and conservative treatment for the therapy of decompensated liver cirrhosis patients with hepatocellular carcinomas (HCC).METHODS:Between October 2000 and July 2003, one hundred patients with histologically proven primary HCC and clinical decompensated liver cirrhosis (Child classification B or C) were included in this study. Forty patients received LRFA (LRFA group), twenty received TACE (TACE group),and forty received conservative treatment (control group).We compared the survival, recurrence, and complication rates in these three groups, making adjustment using the tumor metastastic node staging system.RESULTS:The major complication rate in the TACE group (9/20) was significantly higher than that in the LRFA group (7/40). For patients with TMN stage Ⅱ HCC, the survival rate of the LRFA group was better than that of the TACE and control groups (P=0.003) but the recurrence rates befween the LRFA and TACE groups did not differ.CONCLUSION: The LRFA group of patients had betterclinical outcomes in terms of survival and complication rates in comparison with the TACE group or conservative treatment in patients with decompensated liver cirrhosis, especially in TMN patients with stage Ⅱ HCC. LRFA is thus an appropriate alternative treatment for poor liver function among patientswith HCC.

Value of CT in the diagnosis and management of gallstone ileus

IM: To retrospectively establish the diagnostic criteria of gallstone ileus on CT, and to prospectively apply these criteria to determine the diagnostic accuracy of CT to confirm or exclude gallstone ileus in patients who presented with acute small bowel obstruction (SBO). Another purposewas to ascertain whether the size of ecctopic gallstones would affect treatment strategy.METHODS: Fourteen CT scans in cases of proved gallstone ileus were evaluated retrospectively by two radiologists for the presence or absence of previously reported CT findings to establish the diagnostic criteria. These criteria were applied in a prospective contrast enhanced CT study of 165 patients with acute SBO, which included those 14 cases of gallstone ileus. The hard copy images of 165 CT studies were reviewed by a different group of two radiologists but without previous knowledge of the patient's final diagnosis. All CT data were further analyzed to determine the diagnostic accuracy of gallstone ileus when using CT in prospective evaluation of acute SBO. The size of ectopic gallstone on CT was correlated with the clinical course.RESULTS: The diagnostic criteria of gallstone ileus on CT were established retrospectively, which included: (1) SBO; (2) ectopic gallstone; either rim-calcified or total-calcified; (3) abnormal gall bladder with complete air collection, presence of air-fluid level, or fluid accumulation with irregular wall. Prospectively, CT confirmed the diagnosis in 13 cases of gallstone ileus with these three criteria. Only one false negative case could be identified. The remaining 151 patients are true negative cases and no false positive case could be disclosed. The overall sensitivity, specificity and accuracy of CT in diagnosing gallstone ileus were 93%, 100%; and 99%, respectively. Surgical exploration was performed in 13 patients of gallstone ileus with ectopic stones sized larger than 3 cm. One patient recovered uneventfully following conservative treatment with an ectopic stone sized 2 cm in the long axis. CONCLUSION: Contrast enhanced CT imaging offered crucial evidence not only for the diagnosis of gallstone ileus but also for decision making in management strategy.

Giant malignant gastrointestinal stromal tumors: Recurrence and effects of treatment with STI-571

AIM: Malignant gastrointestinal stromal tumors (GISTs)are rare. Tumors larger than 10 cm tend to recur earlier:the larger the volume of the tumor, the worse the prognosis.We hypothesized that treatment with imatinib mesylate (Gleevec; STI-571), a c-kittyrosine kinase inhibitor, as palliative therapy would prolong the survival of patients with recurrent giant malignant GISTs after resection.METHODS: We performed a retrospective analysis of the effects of resection on patients with giant GISTs (＞10 cm in diameter) to determine the overall survival and recurrence rates. Twenty-three patients diagnosed with giant GISTs were included from June 1996 to December 2003. STI571 was not available until January 2000. After that time,9 patients received this drug. The factors of age, sex, tumor location, histological surgical margin, and STI-571, tumor size changes and drug side effects were reviewed. We compared the survival rate to determine the prognostic factors and the effects of STI-571 on patients with recurrent malignant gastrointestinal stromal tumor.RESULTS: The positive surgical margin group had a significantly higher recurrence rate than the negative margin group (P = 0.012). A negative surgical margin and palliative treatment with STI-571 were significant prognostic variables (Log-rank test,P＜0.05). Age, sex and tumor location were not significant prognostic variables. The 5-year survival rate of the surgical margin free patients was 80%and the 2-year survival rate of the surgical margin positive patients was 28%. The 5-year survival rate was 80% for the patients given STI-571 and 30% for the patients not given STI-571. The use of STI-571 gave a significant tumor shrinkage (6/9) rate in patients with giant GIST recurrence after resection.CONCLUSION: A negative surgical margin and the use of STI-571 after surgical resection were good prognostic indicators. Achieving a tumor-free surgical margin is still the best primary treatment for patients with such tumors.If STI-571 is used immediately when the surgical margin is positive and the tumor recurs after resection, then the prognosis of patients with giant GISTs can be improved.

Effect of water-soluble contrast in colorectal surgery: A prospective randomized trial

AIM: Postoperative gastrointestinal-tract motility is normally delayed. Early feeding after colorectal surgery has beenreposed recently, but late feeding is common. Gastrografin not only enhances bowel peristalsis, but also decreases bowel-wall edema. Whether contrast medium allows early oral feeding and reduces the duration of hospitalization requires clarification.METHODS: Fifty patients underwent elective colorectal surgery in a regional medical center. Patients were prospectively randomized into a Gastrografin group or control group (n = 25 each). Patients in the Gastrografin group began their feeding schedule with 100 mL of 5% dextrose water with 100 mL of Gastrografin on postoperative d 3 and were advanced to a full liquid diet when the contrast reached the colon in 4 h. Patients in the control group began their feeding schedule with 200 mL of 5% dextrosewater on postoperative d 3 and were advanced to a full liquid diet after the passage of flatus and stool. Nasogastric tubes were inserted for persistent postoperative vomiting. Fullness, nausea, vomiting, complications, time of anesthesia, time of operation, time of mobilization, time of oral feeding, and duration of hospital stay were recorded and analyzed with Student's t-test.RESULTS: In the Gastrografin group, one patient hadaspiration pneumonia and one patient had anastomotic leakage resulting in sepsis and eventual death. This mortality was excluded from the subsequent statistical analysis. In the control group, two patients had wound infections. There was no significant difference between the two groups at the time of anesthesia, time of operation, or time of mobilization. There were significant differences between the two groups in the time of oral feeding (3.3±0.3 d in the Gastrografin group vs4.8±0.4 d in the control group; P = odds ratio--, 95%CI [-0.5 to +0.7 d]) and in the length of hospital stay (7.6±1.1 d in the Gastrografingroup vs10.2±1.3 d in the control group; P = odds ratio--, 95% CI [-1.2 to +1.4 d]).CONCLUSION: Gastrografin not only allowed early oralfeeding but also reduced the duration of hospitalizationafter elective colorectal surgery.