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J T Liang

Publications and source records attributed to J T Liang.

At least 19 recordsLinked to original sources
PubMed2003

Clinicopathological and molecular biological features of colorectal cancer in patients less than 40 years of age.

BACKGROUND: The aim of the present study was to identify the clinicopathological and molecular biological characteristics of early-onset colorectal cancers. METHODS: The clinicopathological and molecular biological parameters of 138 consecutive patients with colorectal cancer aged less than 40 years were compared with those of 339 patients aged 60 years or more. RESULTS: The younger patients with colorectal cancer had more mucin-producing (14.5 versus 4.7 per cent; P < 0.001) and poorly differentiated (7.2 versus 3.3 per cent; P = 0.015) tumours, a higher incidence of synchronous (5.8 versus 1.2 per cent; P = 0.007) and metachronous (4.0 versus 0.6 per cent; P = 0.023) colorectal cancers, and more advanced tumour stage (P < 0.001) than older patients. The operative mortality rate was lower (0.7 versus 5.0 per cent; P = 0.026), and cancer-specific survival was similar (in stage I, II and III disease; P > 0.05) or better (in stage IV disease; 95 per cent confidence interval 22.50 to 28.41 versus 12.61 to 17.05 months; P < 0.001). There was a higher percentage of normal p53 expression (61.1 versus 46.8 per cent; P = 0.023) and high-frequency microsatellite instability (MSI-H) (29.4 versus 6.3 per cent; P < 0.001), and a similar family history of cancer (17.5 versus 14.2 per cent; P > 0.05), compared with older patients. CONCLUSION: Young patients with colorectal cancer have several distinct clinicopathological and molecular biological features. The mechanisms underlying the inconsistency between the presence of MSI-H and a family history of cancer in these early-onset colorectal cancers deserve further investigation.

Adolescent↗
PubMed2001

Neurophysiological effects of recurrent laryngeal and thoracic vagus nerves on mediating the neurogenic inflammation of the trachea, bronchi, and esophagus of rats.

The present study aims to investigate the neurophysiological effects of recurrent laryngeal nerve and thoracic vagus nerve on the non-cholinergic regulation of neurogenic plasma extravasation of the rat trachea, bronchi, and esophagus. Through thoracotomy, three nerve components, the right thoracic vagal trunk, thoracic vagus nerve, and recurrent laryngeal nerve, were identified. The experiment was sequentially conducted in four steps. First, the individual nerve component was electrically stimulated and the induced inflammatory responses, as quantified by the area density of India ink-labelled blood vessels in the trachea, bronchial trees and esophagus, were compared. Second, we assessed the relative importance of medial and lateral side of the right thoracic vagus nerve in inducing the inflammatory responses by alternative stimulation of one side with simultaneous severance of the other side of this nerve. Third, we examined the effects of transection of the lateral half of the right thoracic vagus nerve on the degeneration of axon fibers located at the following three sites: the nerve segment proximal to cutting site, bronchial and esophageal nerve branches. Finally, we directly observed the inflammatory histopathology of the right lower trachea after stimulation of the medial half of the right thoracic vagus nerve with transection of its lateral half. In this study, we found that the right recurrent laryngeal nerve was predominant in mediating the neurogenic inflammatory responses of upper and dorsal portions of trachea, whereas the right thoracic vagus nerve was predominant in mediating those of the right lower ventral wall of trachea, right main bronchus, and right lobar bronchial trees. The axon fibers of the right thoracic vagus nerve responsible for mediating the neurogenic inflammatory responses of the right lower ventral trachea were mainly accumulated in the medial half, whereas those innervating the right main bronchus, right lobar bronchial trees, and lower esophagus were largely in the lateral half of this nerve. Transection of the lateral half of the right thoracic vagus nerve resulted in significant degeneration of myelinated fibers in its bronchial and esophageal nerve branches. Histopathological examination of the right lower trachea after electrical stimulation of the medial half of thoracic vagus nerve demonstrated the silver-stained leaky venules with accumulations of inflammatory cells. We thus concluded that afferent C-fibers to upper and dorsal portions of trachea were mainly from recurrent laryngeal nerve. In contrast, the neurogenic inflammatory responses of the right lower trachea were predominantly mediated by the medial half of the right thoracic vagus nerve, and those of the right main bronchus, bronchial trees and lower esophagus were largely by the lateral half of this nerve.

Animals↗
PubMed2000

Color Doppler vascularity index can predict distant metastasis and survival in colon cancer patients.

The purpose of this study was to investigate the clinical usefulness of the color Doppler vascularity index (CDVI) in patients with colon cancer before surgery. Forty-four patients with sonographically visible tumor mass of colon cancer were investigated. The CDVI of each tumor was determined using transabdominal color Doppler ultrasound. The CDVI was defined as the ratio of the number of the colored pixels within a tumor section to the number of total pixels in that specific tumor section and was calculated by using Encomate software (Electronic Business Machine Co. Ltd., Taipei, Taiwan). The correlation between the CDVI and clinicopathological factors, mode of recurrence, and patient survival was studied. For comparison, microvessel density (the mean number of microvessels in three areas of highest vascular density at x200 magnification) of the tumors of these 44 patients was also evaluated by using immunohistochemical staining of surgical specimens with anti-CD34. The microvessel density was not correlated with Dukes' classification, clinicopathological factors, and survival. The CDVI was significantly higher in the patients with lymph node metastases and vascular invasion than in those without such metastases and invasion (P = 0.006 and P = 0.0098, respectively). Moreover, in patients with a high CDVI (> 15%) and positive vascular invasion, survival was significantly poorer than in those with low CDVI (< or = 15%) and negative invasion (P = 0.0037 and 0.0039, respectively). Multivariate analysis indicated that liver metastasis, vascular invasion, and CDVI are independent prognostic factors in the patients with colon cancer. According to the mode of recurrence in 36 patients who underwent curative resection, the frequency of the distant organ recurrence was significantly higher in the high CDVI group (40%) than in the low CDVI group (0%). The CDVI is a good preoperative indicator of recurrence and patient survival in colon cancer. Thus, the CDVI may be helpful in stratifying patients for adjuvant therapy.

Adult↗
PubMed2000

Spontaneous bowel perforation in infants and young children: a clinicopathologic analysis of pathogenesis.

BACKGROUND: In children beyond the neonatal stage, spontaneous bowel perforation with no specific cause is rare. It has attracted little notice and does not fit into any established clinical category. This often results in treatment delays. To determine the underlying pathogenesis, a clinicopathologic analysis of this group of patients was performed. METHODS: From 1984 through 1997, 15 previously healthy children (10 boys and 5 girls) with bowel perforations were enrolled in this study. Children in whom the specific cause was established were excluded. The ages of the patients ranged from 3 months to 5 years, 5 months (average age: 2 years, 4 months). Data on clinical course, surgical and pathologic findings, and outcomes were analyzed. RESULTS: All the patients had high fever and acute, watery diarrhea with clinical dehydration. Abdominal distension developed and bowel perforation ensued 5 to 30 days after the onset of diarrhea. In all cases, the perforation consisted of either an isolated patch of bowel (n = 8) or patchy lesions in a segment (n = 7), which was confined to one of the following three anatomic watershed areas: the splenic flexure (n = 7); the lower sigmoid (n = 3); and the ileocecal region (n = 5). One patient died, and three had major sequelae including intra-abdominal abscess, adhesion ileus, and peristomal fistula. Specimens from 13 patients were submitted for histopathologic evaluation. All specimens had acute suppurative inflammation diffusely around the perforation site. Seven had areas of coagulation necrosis of the muscularis propria, especially in the inner circular muscle layer. CONCLUSION: In acute diarrheal diseases, dehydration may cause bowel ischemia and lead to perforation. Physicians should be alert to the possibility of this abdominal catastrophe when progressive abdominal distension followed by acute diarrheal episodes occurs in children.

Acute Disease↗
PubMed1999

Hypermethylation of the p16 gene in sporadic T3N0M0 stage colorectal cancers: association with DNA replication error and shorter survival.

Hypermethylation in the promoter region of the p16 gene was suspected to be involved in the tumorigenesis of colorectal cancers, although its clinical and biological significance remains obscure. In this study, we collected 84 T3N0M0 stage primary colorectal cancers that were curatively resected. The clinicopathologic data were reviewed. p16 hypermethylation was determined by a methylation-specific polymerase chain reaction (PCR). p53 overexpression was detected by immunocytochemistry (ICC). The point mutations in the 12 and 13 codons of the K-ras gene were screened by restriction enzyme analysis. Loss of heterozygosity (LOH) of the DCC (Deleted in Colorectal cancer) gene was examined by PCR using primers of the DCC (18q21) microsatellite marker. The DNA replication error (RER) was examined using 7 microsatellite markers at distinct chromosomal loci. p16 hypermethylation, regarded as an indication of p16 inactivation, was evident in 24 (28.6%) of the tumors. No correlation was found between p16 hypermethylation and various clinicopathologic factors, includinig age, sex, tumor location, tumor size, growth pattern, tumor differentiation, mucin production, vascular and/or lymphatic invasion, lymphocyte infiltration of the tumor, and serum level of carcinoembryonic antigen. There was no association between p16 hypermethylation of K-ras gene mutation, p53 overexpression and LOH of the DCC gene. However, p16 hypermethylation was significantly associated with DNA RER (p = 0.01). Survival analysis revealed a significant survival disadvantage of p16-hypermethylated versus non-p16-hypermethylated tumors (p = 0.0001). These findings indicate that p16 hypermethylation plays a role in the carcinogenesis of a subset of colorectal cancers; and the presence of p16 hypermethylation predicts shorter survival in T3N0M0 stage colorectal cancers.

Aged↗
PubMed1997

Flat adenoma of the colon: two cases.

Flat adenoma has been frequently reported to have a higher potential for malignant change than other polypoid adenomas. It is an endoscopically visible sessile lesion that consists histologically of an adenomatous change of the colonic mucosa. Detection, diagnosis, and treatment of flat adenoma has not previously been reported in Taiwan. We found such lesions in two patients during colonoscopic examinations as patches of discolored and irregular mucosa. Histopathologic studies revealed adenomas with mild to moderate dysplasia. Patient 1 underwent segmental colectomy; patient 2 underwent an endoscopic strip biopsy. Focal malignant changes were noted in patient 1. Both patients received close follow-up at the outpatient clinic. No recurrence has been seen in patient 1. Patient 2 developed an enlarged sessile lesion with a histologic picture showing a tubular adenoma without malignancy but refused further surgical treatment. This paper outlines the endoscopic and pathologic characteristics of flat adenoma in two patients, and should alert physicians to the importance of early detection and treatment of this lesion.

Adenoma↗
PubMed1996

Colorectal surgery using a biofragmentable anastomotic ring.

To compare the efficacy of the biofragmentable anastomotic ring (Valtrac-BAR, Davis and Geck, Medical Device Division, Danbury, CT, USA) with conventional anastomotic techniques, 30 patients who underwent colorectal surgery from August 1993 to March 1995 were retrospectively studied. The use of the BAR was also compared with conventional techniques including hand-sewn sutures in 30 patients and an end-to-end anastomosis (EEA) stapler in 24 patients. There were 17 men and 13 women in the BAR group with ages ranging from 37 to 80 years, 18 men and 12 women in the hand-sewn group with ages ranging from 41 to 82 years and 14 men and 10 women in the EEA group with ages ranging from 38 to 72 years. Surgical indications included: 25 colon cancers and five rectal cancers in the BAR group; 27 colon cancers and three rectal cancers in the hand-sewn group; and six colon cancers and 18 rectal cancers in the EEA group. There was no conversion to other anastomotic methods. Most of the patients tolerated a low-residual diet from the fifth post-operative day. No clinical leakage or stricture was noted. Only seven patients were aware of the passage of BAR fragments. The mean hospital stay was 14.1 days. There were no significant differences among these techniques in the return of bowel function, the incidence of surgical complications, including anastomotic leakage, or the length of hospitalization. BAR anastomosis was more time efficient than conventional techniques. Our results confirmed that BAR was an ideal sutureless alternative for anastomosis in colorectal surgery.

Adult↗
PubMed1995

Splenic abscess: a diagnostic pitfall in the ED.

Splenic abscess, with its rare incidence and various misleading clinical manifestations, usually is a diagnostic pitfall in the modern emergency department. The most frequently seen symptoms and signs are fever, abdominal pain and tenderness over left upper quadrant, splenomegaly, leucocytosis, and left lower chest abnormalities. Four cases were collected during the past five years. On admission, one patient manifested symptoms mimicking a perforated peptic ulcer and the other three patients presented clinical and roentgenographic signs suggestive, but non-specific, for splenic abscess. In two cases, the diagnosis was based on sonography followed by computed tomography (CT). In one case, the splenic abscess was only visualized by CT. They all survived after splenectomy and appropriate antibiotic therapy. Culturing disclosed the offending organisms to be Escherichia coli, Pseudomonas aeruginosa, a Salmonella species, and Streptococcus viridans. These nonspecific clinical pictures should be thoroughly investigated, and CT, the most sensitive diagnostic tool, should be used whenever splenic abscess is suspected. Early diagnosis and timely treatment reduce the morbidity and mortality associated with splenic abscess.

Abdominal Pain↗
PubMed1993

Circulating intercellular adhesion molecule-1 and lymphocyte subsets involved in immune response of breast cancer.

To understand the immune responses of patients with breast cancer, circulating intercellular adhesion molecules-1 (ICAM-1) and lymphocyte subsets were measured in patients with breast cancer and in healthy persons. There were 10 patients of with metastasis, 11 patients breast cancer without metastasis and 9 age-and-sex matched healthy persons. Their serum samples were counted for circulating ICAM-1 levels, and blood cells were calculated for lymphocyte subpopulation including CD3, CD4, CD8 and CD19 by using flow cytometry. Higher levels of circulating ICAM-1 were noted in patients with breast cancer and metastasis than those without metastasis (p < 0.01). Lower percentage of CD8 lymphocyte subset were found ih patients with breast cancer and metastasis than those without metastasis (p < 0.05). Shedding of ICAM-1 antigens from the tumor may block the attachment of cytotoxic T cells, and decreased numbers of cytotoxic T cells may be unable to inhibit the spread of cancer cells. Immune responses of patients with breast cancer may be different between metastatic status and limited status. Further investigations should correlate the results of tissue stains of breast cancer with ICAM-1 and lymphocyte markers with those from peripheral blood.

Adult↗
PubMed1987

Isolation and characterization of plasma membrane proteins of cultured human retinal pigment epithelium.

Two-dimensional gel electrophoresis (2-D) was used to resolve the plasma membrane proteins from cultured human retinal pigment epithelial cells. The cells were metabolically labeled either with [35S]methionine to reveal proteins in general or with [3H]glucosamine or [3H]fucose which are more specific for glycoprotein visualization. The cell surface proteins were also iodinated, using the lactoperoxidase--glucose oxidase technique. These labeled membranes were separate into plasma membrane-enriched fractions by subjecting the water-shocked postnuclear supernatant to a discontinuous sucrose-density gradient. The five resulting membrane fractions were assayed for protein, RNA (microsomes), galactosyltransferase (Golgi membranes), 5'-nucleotidase (plasma membranes), and succinate dehydrogenase (mitochondrial membranes) and were examined by electron microscopy. The plasma membranes were enriched with minimal contamination at the 0.6-0.85 M (F2) and 0.85-1.0 M (F3) sucrose interfaces based on these biochemical and morphological criteria. Examination of 2-D autoradiographic profiles of F2 and F3 showed that approximately 180 proteins or protein subunits had incorporated [35S]methionine. Certain proteins were also labeled by [3H]glucosamine and [3H]fucose, and surface-labeled by iodination. This was especially true of 17 different high-molecular-weight (43-139 X 10(3) MW) very acidic glycoproteins which formed a constellation of spots. These glycoproteins, as well as others, were also seen in the whole-cell acidic glucosamine-labeled 2-D profiles, where about 150 proteins were detected. A total of 39 proteins were catalogued, of which 34 were detectable in the plasma membrane-enriched fractions. The results show that the use of subcellular fractionation, specific precursors, and labeling techniques aids in the detection and characterization of minor proteins in 2-D gels.

Adult↗
PubMed1984

Effects of repeated isocaloric macronutrient loads on daily food intake of rats.

The effects of repeated administration of different macronutrient loads on spontaneous food intake and body weight of male Sprague-Dawley rats were studied. For 6 wk, eight groups of five rats each received two daily intragastric loads, 3.5 h apart, consisting of isocaloric amounts of one of the following: albumin, sucrose, cornstarch, corn oil, a mixture of the preceding four loads, butter, medium-chain triglyceride, or a noncaloric load of water. Spontaneous intakes of rat chow were measured 3.5 and 24 h after the first daily load. All the macronutrient loads depressed subsequent 3.5-h intakes more than the water load (P less than 0.01), and protein loads depressed 3.5-h intakes the most (P less than 0.01). The macronutrient loads also depressed 24-h intakes more than water loads (P less than 0.01) but did not differ among themselves. The mixture load depressed 3.5- and 24-h food intakes by an amount comparable with the average effects of its component loads. Neither body weight nor body fat as measured by the Lee index differed among the groups after 6 wk. The results indicate that fairly accurate long-term regulation of spontaneous energy intake occurs regardless of the type of macronutrient in the load.

Animals↗
PubMedDate not supplied

Reappraisal of K-ras and p53 gene mutations in the recurrence of Dukes' B2 rectal cancer after curative resection.

BACKGROUND/AIMS: Recurrence of rectal cancer remains a major clinical problem. This study was conducted to evaluate the impact of K-ras and p53 mutations on the recurrence of rectal cancer. METHODOLOGY: A total of 166 resected Dukes' B2 stage rectal carcinomas were collected between January 1990 and April 1994. The stored frozen tissues were retrieved for immunocytochemistry of p53 and genomic analysis of K-ras and p53 genes. The data of K-ras and p53 gene mutations were correlated with clinicopathological variables. The concordance of immunocytochemistry with genomic analysis in the survey of p53-mutations was examined. The follow-up data were analyzed by Kaplan-Meier estimator. RESULTS: Sixty-nine patients (41.6%) developed recurrent tumor. A significantly higher recurrence rate (p = 0.0013) and shorter median recurrence time were noted in p53 mutated than non-mutated cancers. Mutations in K-ras gene do not significantly increase the risk of tumor recurrence (p = 0.1702). K-ras and p53 mutations are not associated with clinicopathological parameters (p > 0.05). Kappa statistic indicates highly significant reproducibility between immunocytochemistry and genomic analysis for p53 mutations (p < 0.0001). CONCLUSIONS: Presence of p53 mutation significantly increases the recurrence rate and shortens the recurrence time of the resected rectal cancers. Pre-operative routine check for p53 mutations by immunocytochemistry may be beneficial in choosing the optimal surgical strategy for rectal cancer.

Aged↗
PubMedDate not supplied

Clinicopathologic and carcinogenetic appraisal of DNA replication error in sporadic T3N0M0 stage colorectal cancer after curative resection.

BACKGROUND/AIMS: DNA replication error (RER) was found to play a role in the carcinogenesis of a subset of sporadic colorectal cancers. This study was conducted to evaluate the clinicopathologic implications of RER in T3N0M0 stage colorectal cancers. To better understand the carcinogenesis of sporadic colorectal cancer, the RER status was further correlated with the alterations of K-ras, p53 and deleted in colorectal cancer (DCC) genes which were frequently involved in the adenoma-carcinoma sequence. METHODOLOGY: Seventy-eight patients with curatively resected T3N0M0 stage sporadic colorectal cancer were accumulated. The stored frozen tissues were retrieved for analyses of 1) microsatellite instability at 7 distinct chromosomal loci, 2) loss of heterozygosity at DCC gene, 3) K-ras gene mutation, 4) p53 expression, and 5) DNA content. The RER status was correlated with various clinicopathologic and molecular genetic factors. The survival of patients stratified by RER status was analyzed by Kaplan-Meier estimator. RESULTS: The RER-positive tumor was detected in 32.1% (25/78) of patients. The RER-positive cancer patients presented with distinct clinicopathologic features including young age of tumor onset, proximal tumor location, mucin production in histology, a higher rate of synchronous and metachronous colorectal cancers, and an increased incidence of extracolonic primary cancer. Patients with RER-positive tumor were found to have an improved prognosis with the 5-year survival probability of 76% and 45% in RER-positive and RER-negative groups, respectively (p < 0.05). The RER-positive tumors tended to have normal p53 expression, DNA diploidy, and a lower DNA index. The rate for the loss of heterozygosity of DCC gene was significantly lower in RER-positive tumors. RER status was not associated with K-ras mutation. CONCLUSIONS: The clinicopathologic features and carcinogenesis of RER-positive sporadic colorectal cancers were considered different from those of RER-negative tumors. The presence of RER may identify a subset of less aggressive tumors with good prognosis in T3N0M0 stage colorectal cancers.

Adenocarcinoma↗
PubMedDate not supplied

Fulminant hepatic failure in a renal transplant recipient with positive hepatitis B surface antigens: a case report of fibrosing cholestatic hepatitis.

This 28-year-old male, a hepatitis B virus (HBV) carrier, received cadaveric renal transplantation and was maintained on cyclosporin A and prednisolone. Jaundice occurred 8 months after the transplantation and he died 2 weeks later due to hepatic failure. The liver histologic findings were compatible with fibrosing cholestatic hepatitis (FCH), which is caused by HBV and has only been reported in liver allografts of orthotopic liver transplantations. This is the first case of FCH developing in a renal transplant recipient. The report illustrates that (1) FCH is also a unique histologic entity in renal transplantations; (2) FCH might occur in a liver chronically infected by HBV without co-existing hepatitis D virus; and (3) FCH can cause fulminant hepatic failure within one year after transplantation while the patient is still in an immunosuppressed state.

Adult↗