Biomedical subjects

J-T Liang

Publications and source records attributed to J-T Liang.

5 recordsLinked to original sources

PubMed2006

Multimedia article. Laparoscopic abdominoperineal resection for lower rectal cancers: how do we do it?

BACKGROUND: The appropriateness of the laparoscopic approach for the resection of rectal cancer has been controversial, although it is well established in colon cancer. This is a phase II study of laparoscopic abdominoperineal resection (APR) in the treatment of lower rectal cancers. METHODS: Patients with lower rectal adenocarcinoma located within 6 cm above the anal verge were recruited and subjected to laparoscopic APR. The surgical principle included en bloc resection with high ligation of inferior mesenteric vessels by no-touch isolation and total mesorectal excision. Details of the surgical procedures are presented in the video. The technical efficiency and outcome of this surgical approach were evaluated prospectively. This study was approved by the institutional review board of National Taiwan University Hospital (NTUH). RESULTS: A total of 22 patients were enrolled in the study from January 2003 to December 2004 under the ethical guidelines of clinical trials in NTUH. There were 12 females and 10 males, with an age distribution of 62.5 +/- 10.4 years. The body mass index was 24.8 +/- 4.0 kg/m2. Physical status (American Society of Anesthesiology classification) was class I in 12, class II in eight, and class III in two patients. Tumor size was 44.0 +/- 12.0 mm in diameter. Two patients were in pathologic TNM stage I, 14 in stage II, and six in stage III. The operation time was 214.0 +/- 28.4 min. Blood loss was 54.0 +/- 14.0 ml. Because the tumor specimen was retrieved from a perineal wound, the five 5 to 12 mm working ports constituted the abdominal wound. There were no major complications. However, wound infection of port sites was detected in one patient. The patients had a quick convalescence, as evaluated by the length of postoperative ileus (48.0 +/- 12.0 h), length of hospitalization (8.0 +/- 2.0 days), and degree of postoperative pain (3.5 +/- 0.5 visual analogue scale). Return to partial activity, full activity, and work was 2.0 +/- 0.5, 4.0 +/- 0.8, and 6.0 +/- 0.5 weeks, respectively. The number of cleared lymph nodes was 14.0 +/- 2.0. During follow-up (median, 18 months; range, 6-30), lung metastasis and local pelvic recurrence developed in one and two patients, respectively. Besides the expenses covered by the National Bureau of Health Insurance of Taiwan, the additional payment by patients undergoing laparoscopic procedures was NTD 24,000 +/- 3000 (1 U.S. dollar = 32 NTD). CONCLUSIONS: In our clinical setting, laparoscopic APR can be performed with good technical efficiency, quick functional recovery, and mild disability. The short-term oncologic results of laparoscopic APR seem to be acceptable, but further long-term follow-up for these patients is mandatory to define the oncologic outcomes of this approach.

Abdomen↗

PubMed2006

C2GnT-M is downregulated in colorectal cancer and its re-expression causes growth inhibition of colon cancer cells.

Changes in carbohydrates on the cell surface are associated with tumor malignancy. The mucin-type core 2 beta-1,6-N-acetylglucosaminyltransferase (C2GnT-M) is highly expressed in the gastrointestinal tract and catalyses the formation of core 2, core 4, and blood group I branches on O-glycans. In the present study, we evaluated the role of C2GnT-M in colorectal cancer. C2GnT-M downexpression was observed in 73.6% of the primary tumors from colorectal cancer patients (39 of 53) analysed by cancer profiling array. Consistently, the majority of colon cancer cell lines and primary colon tumors expressed lower levels of C2GnT-M than did normal colon tissues by RT-PCR. HCT116 cells stably transfected with C2GnT-M inhibited expression of the core 1 structure, Galbeta1,3GalNAcalpha1-Ser/Thr, on the cell surface. Moreover, C2GnT-M expression suppressed cell adhesion, motility, and invasion as well as colony formation ability. The growth of C2GnT-M-transfected HCT116 and SW480 cells was dramatically suppressed, and the cell death induced by C2GnT-M was demonstrated by an increase in the annexin V-positive cells. Interestingly, C2GnT-M inhibited cell adhesion to collagen IV and fibronectin, and decreased tyrosine phosphorylation of paxillin, indicating that the changes in cancer behavior may be partly mediated by integrin-signaling pathways. Tumor growth in vivo was also significantly suppressed by C2GnT-M in the xenografts of nude mice. These results demonstrate that C2GnT-M is frequently downregulated in colorectal cancer and suppresses colon cancer cell growth.

Animals↗

PubMed2006

Elective laparoscopically assisted sigmoidectomy for the sigmoid volvulus.

BACKGROUND: The laparoscopic approach for the treatment of sigmoid volvulus has been a rare surgical indication. This phase 2 study investigated the feasibility and surgical outcomes of elective laparoscopic surgery for sigmoid volvulus. METHODS: Patients with sigmoid volvulus were first offered colonoscopic decompression for their acute colonic obstruction. If the colonic decompression was successful, complete bowel preparation was performed, followed by elective laparoscopically assisted sigmoidectomy. The details of the laparoscopic procedures are shown in the video. Briefly, the redundant sigmoid colon is totally mobilized by a laparoscopic medial-to-lateral dissection sequence, after which it is exteriorized, transected, and reconstructed by end-to-end anastomosis. In the authors' experience, the medial-to-lateral approach is highly efficient for the laparoscopic mobilization of the redundant sigmoid colon. We believe that the longer the lateral abdominal wall attachment of the sigmoid colon is preserved, the better the exposure and the easier the dissection. If the risk of anastomotic leakage is considered high in a specific case, protective ileostomy is selectively preformed. Before entering the current study, the patients were well informed about the advantages and disadvantages of laparoscopic surgery. The enrollment of patients was selective according to the appropriate eligibility criteria. This study was approved by the Institutional Review Board of the National Taiwan University Hospital. The patients' clinicopathologic data and surgical outcomes were prospectively evaluated. RESULTS: Between August 2001 and April, 2005, a total of 14 patients (10 men and 4 women) with sigmoid volvulus were treated with the described procedure. The age distribution of the patients was 68.4 +/- 12.2 years. The attack of sigmoid volvulus was the first episode for eight patients, the second episode for 4 patients, and the third episode (or more) for two patients. The body mass index (BMI) of the patients was 26.8 +/- 4.4 kg/m(2). The physical status (classification of American Society of Anesthesiology [ASA]) was 1 for five patients, 2 for eight patients, and 3 for 1 patient. During the laparoscopy, all the patients presented with the pathognomonic findings of sigmoid volvulus including redundant sigmoid colon, narrow sigmoid mesenteric pedicle, and mesosigmoiditis with mesenteric fibrosis and scarring, as shown in the video. The length of the resected colon was 32 +/- 6 cm. The operation time was 194.6 +/- 32.4 min, and the blood loss was 44.0 +/- 12.4 ml. The abdominal wound consisted of four 5 to 12 mm working ports and a 5 cm major wound for exteriorization of the sigmoid colon. Some surgeons have shown that a sigmoid volvulus can be resected through a 5-cm left lower quadrant incision with very little mobilization of the colon because of its redundancy. In this context, the laparoscopic approach competed with the minilaparotomy method in terms of adequate sigmoid resection, lysis of mesosigmoid adhesion, and tension-free colorectal anastomosis. Protective ileostomy was performed for the only patient with a physical status of ASA 3. There was no mortality in this case series. However, pneumonia developed postoperatively in one patient, acute myocardial infarction in one patient, and wound infection in two patients. Excluding the two patients who experienced postoperative pneumonia and acute myocardial infarction, the duration of the postoperative ileus was 48 +/- 12 h, the postoperative hospitalization was 7 +/- 1 days, and the degree of postoperative pain was 3.5 +/- 0.5 according to the visual analog scale. The return to partial activity required 18 +/- 2.5 days, and the return to full activity required 28.4 +/- 5.6 days. As compared with the overall costs for a conventional sigmoid colectomy, which are completely covered by the National Bureau of Health Insurance of Taiwan, the expenses for the patients undergoing laparoscopic procedures were significantly higher by approximately 24,000.0 NT dollars +/- 2,635.0 (1 U.S. dollar = 32 NT dollars). These higher expenses must be borne by the patients themselves. CONCLUSION: Considering that patients with sigmoid volvulus often are elderly and chronically ill, laparoscopic elective surgery after a successful colonoscopic decompression may be a good choice for a selected group of patients in terms of minimized surgical complications and quick convalescence.

Aged↗

PubMed2006

Aminoguanidine prevents arterial stiffening in a new rat model of type 2 diabetes.

BACKGROUND: Formation of advanced glycation end-products (AGEs) on collagen within the arterial wall may be responsible for the development of diabetic vascular injury. This study focused on investigating the role of aminoguanidine (AG), an inhibitor of AGE formation, in the prevention of noninsulin-dependent diabetes mellitus (NIDDM)-derived arterial stiffening and cardiac hypertrophy in rats. MATERIALS AND METHODS: The NIDDM was induced in male Wistar rats, which were administered intraperitoneally with 180 mg kg(-1) nicotinamide (NA) 30 min before an intravenous injection of 50 mg kg(-1) streptozotocin (STZ). After induction of diabetes mellitus type 2, animals receiving daily peritoneal injections with 50 mg kg(-1) AG for 8 weeks were compared with the age-matched, untreated, diabetic controls. RESULTS: After exposure to AG, the STZ-NA diabetic rats had improved aortic distensibility, as evidenced by 18.8% reduction of aortic characteristic impedance (P < 0.05). Treatment of the experimental syndrome with AG also resulted in a significant increase in wave transit time (+23.7%, P < 0.05) and a decrease in wave reflection factor (-26.6%, P < 0.05), suggesting that AG may prevent the NIDDM-induced augmentation in systolic load of the left ventricle. Also, the glycation-derived modification on aortic collagen was found to be retarded by AG. The diminished ratio of left ventricular weight to body weight suggested that prevention of the diabetes-related cardiac hypertrophy by AG may correspond to the drug-induced decline in aortic stiffening. CONCLUSIONS: Long-term administration of AG to the STZ-NA diabetic rats imparts significant protection against the NIDDM-derived impairment in vascular dynamics, at least partly through inhibition of the AGE accumulation on collagen in the arterial wall.

Animals↗

PubMed2004

Microvessel density, cyclo-oxygenase 2 expression, K-ras mutation and p53 overexpression in colonic cancer.

BACKGROUND: Tumour angiogenesis, cyclo-oxygenase (COX) 2 expression, K-ras mutation and p53 overexpression are commonly involved in colorectal tumorigenesis, but their interrelationship and clinicopathological effects remain inconclusive. METHODS: Clinicopathological data from 114 consecutive patients with primary stage III colorectal cancer were evaluated prospectively. Microvessel density (MVD) of the tumour was defined by counting the number of microvessels in hotspots, visualized by immunocytochemical staining of endothelial CD34. K-ras mutation was analysed by the restriction enzyme cleavage method. COX-2 expression and p53 overexpression were determined by immunocytochemistry. RESULTS: Increased MVD in hotspots was significantly associated with COX-2 expression (P < 0.001), K-ras mutation (P = 0.007) and p53 overexpression (P = 0.006). COX-2 expression was not associated with either K-ras mutation or p53 overexpression. Clinicopathologically, greater MVD and COX-2 expression were significantly associated with vascular invasion of cancer cells (MVD, P = 0.027 and COX-2 expression, P = 0.006), but p53 overexpression and K-ras mutation were not. Multivariate analysis indicated that greater MVD (P = 0.002) and p53 overexpression (P = 0.016) were significant independent predictors of tumour recurrence, whereas COX-2 expression (P = 0.634) and K-ras mutation (P = 0.356) were not. CONCLUSION: Tumour angiogenesis may be associated with tumour metastasis and is significantly influenced by K-ras mutation, p53 overexpression and COX-2 expression in patients with colonic cancer.

Adult↗