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C T Shun

Publications and source records attributed to C T Shun.

At least 19 recordsLinked to original sources
PubMed2001

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer.

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

Chromosome Aberrations↗
PubMed2001

Expression of integrins in human cultured mesothelial cells: the roles in cell-to-extracellular matrix adhesion and inhibition by RGD-containing peptide.

Integrins play key roles in cell-to-cell and cell-to-extracellular matrix (ECM) adhesion. We investigated integrin expression on pleural mesothelial cells (PMCs) and the inhibitory effect of arginine-glycine-asparate (RGD)-containing peptide on the adhesion of PMCs to fibronectin and collagen. Using flow cytometry and immunostaining, PMCs freshly isolated from pleural effusions and one mesothelial cell line were screened for different integrins. Intact pleural tissue was evaluated by immunohistochemistry. The adhesion of Met-5A cells to fibronectin and collagen types I, III and IV was assayed with prior treatment of various concentrations of glycine-arginine-glycine aspartate-serine (GRGDS). On primary PMCs, alpha2, alpha3, alpha5, beta1, beta3 and alphavbeta3 were highly expressed (>70%); alpha1 expression was intermediate (30-70%); and alpha4 and alpha6 expressions were low (< 30%). On Met-SA cells, alpha3, alpha5, alpha6 and beta1 were highly expressed (>70%); alpha1 was intermediate (30-70%); and alpha2, alpha4, beta3 and alphavbeta3 were low (<30%). The patterns of immunostaining on pleural tissues were similar to the results of flow cytometry for primary PMCs except for beta3. There was no statistically different expression in various disease states (transudate vs. exudate, benign vs. malignant). The inhibitory effect of GRGDS peptide on Met-5A cell adhesion to all four matrix proteins was dose-dependent.

Adolescent↗
PubMed2001

A 60-kilodalton immunodominant glycoprotein is essential for cell wall integrity and the maintenance of cell shape in Streptococcus mutans.

We have demonstrated previously by Western blotting that in naturally sensitized humans, the serum or salivary antibody response to Streptococcus mutans was directed predominantly to a protein antigen with a size of approximately 60-kDa. To identify this immunodominant antigen, specific serum antibodies were eluted from immunoblots and five positive clones with inserts ranging in length from 3 to 8 kb from identical chromosomal loci were obtained by screening a genomic expression library of Streptococcus mutans GS-5. Amino acid sequencing established the identity of this immunodominant antigen, a 60-kDa immunodominant glycoprotein (IDG-60), to be a cell wall-associated general stress protein GSP-781, which was originally predicted to have a molecular mass of approximately 45 kDa based on the derived nucleotide sequence. Discrepancy in the molecular mass was also observed in recombinant his-tagged IDG-60 (rIDG-60) expressed from Escherichia coli. Glycosylation, consisting of sialic acid, mannose galactose, and N-acetylgalactosamine, was detected by lectin binding to IDG-60 in cell wall extracts from S. mutans and rIDG-60 expressed in vivo or translated in vitro. Despite the presence of multiple Asn or Ser or Thr glycosylation sites, IDG-60 was resistant to the effect of N-glycosidase F and multiple O-glycosidase molecules but not to beta-galactosidase. Insertional inactivation of the gene encoding IDG-60, sagA, resulted in a retarded growth rate, destabilization of the cell wall, and pleiomorphic cell shape with multifold ingrowth of cell wall. In addition, distinct from the parental GS-5 strain, the isogenic mutant GS-51 was unable to survive the challenge of low pH and high osmotic pressure or high temperature. Expression of the wild-type gene in trans within GS-51 from plasmid pDL277 complemented the growth defect and restored normal cell shape. These results suggested that IDG-60 is essential for maintaining the integrity of the cell wall and the uniformity of cell shape, both of which are indispensable for bacteria survival under stress conditions.

Adult↗
PubMed2001

Immunohistochemical evaluation of cadherin and catenin expression in early gastric carcinomas: correlation with clinicopathologic characteristics and Helicobacter pylori infection.

Dysfunction of E-cadherin and catenin has been linked to invasiveness and differentiation of tumors. This study aimed to characterize the expression of cadherins and catenins in early gastric carcinoma and their relationship to clinicopathologic characteristics and Helicobacter pylori infection. E-cadherin and alpha-, beta- and gamma-catenins were strongly expressed in normal epithelium but abnormal immunoreactivity of at least one of these four proteins was noted in 48 (90.6%) of 53 early gastric carcinomas. Only 5 cases with intestinal-type tumors had intact expression of E-cadherin and alpha-, beta-, and gamma-catenins. Abnormal immunoreactivity in the tumor tissue was observed in 18 patients (34.0%) for E-cadherin, in 35 (66.0%) for alpha-catenin, in 20 (37.7%) for beta-catenin, and in 37 (69.8%) for gamma-catenin. In diffuse-type tumors, abnormal expression of E-cadherin (60.9 vs. 13.3%, p < 0.0005), alpha-catenin (82.6 vs. 53.3%, p < 0.05) and gamma-catenin (91.3 vs. 53.3%, p < 0.005) was more frequent than in the intestinal type. Ten tumors with lymph node metastasis showed a relatively higher frequency of abnormal expression of E-cadherin (70 vs. 25.6%, p < 0.05) but a lower frequency of abnormal expression of beta-catenin (10 vs. 44.1%, p = 0.07) than those without metastasis. No significant association was found between cadherin/catenin expression and the depth of invasion or the H. pylori status. It was concluded that abnormal expression of E-cadherin and the catenin-mediated cell-cell adhesion system occurs frequently in early gastric carcinogenesis and may play an important role in the genesis of histologic differentiation and in the mode of metastasis of early gastric carcinomas.

Armadillo Domain Proteins↗
PubMed2001

Matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 gene expressions and their differential regulation by proinflammatory cytokines and prostaglandin in nasal polyp fibroblasts.

Chronic inflammation of the paranasal sinus leads to nasal polyp (NP) formation. In this study, we investigated the effect of stimulation of the proinflammatory cytokines interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) and prostaglandin (PG) E2 on the production of messenger RNA (mRNA) of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-I (TIMP-1) in nasal polyp fibroblasts (NPFs) and nasal mucosa fibroblasts (NFs). The mRNAs of IL-1alpha, TNF-alpha, MMP-1, and TIMP-1 in 40 surgical specimens of NPs were studied by in situ hybridization to corroborate the in vitro findings. The results indicated a significant amount of constitutive MMP-1 mRNA in NPFs and cytokine-induced MMP-1 steady-state mRNAs in NFs. The effect of stimulation of cytokines on TIMP-1 mRNA synthesis was unremarkable in NPFs and NFs. Exogenous PGE2 enhanced cytokine-stimulated MMP-1 mRNA synthesis in NPFs. In situ hybridization revealed that cells expressing MMP-1 and TIMP-1 mRNAs (primarily plasma cells, fibroblasts, and endothelial cells) gathered around areas with loose stroma, suggestive of rapid extracellular matrix degradation. These data suggest that the pathogenesis of nasal polyposis could be related to production of MMP-1 and consequent promotion of matrix collagenolysis.

Cytokines↗
PubMed2001

K-ras mutation at codon 12 in stage I pancreatic adenocarcinoma: analysis by laser capture microdissection and direct sequencing.

Pancreatic ductal adenocarcinoma has been reported to carry a rate mutation high in codon 12 of the K-ras oncogene. To avoid the pitfalls of conventional methods of tissue dissection that might affect the sensitivity and specificity of detecting K-ras mutation, laser capture microdissection (LCM) technique was used. Pancreatic adenocarcinoma tissues were obtained from 15 patients who underwent Whipple's procedure. Selected tissues procured by LCM were analyzed by direct sequencing after polymerase chain reaction amplification of K-ras sequences at codon 12. K-ras mutation was noted in nine patients. All mutations showed G to A substitution at codon 12. The mutational pattern (GGT to GAT) is similar in both western and eastern reports. LCM is a feasible method to effectively obtain pure tumor cells from a surgical specimen. It remains to be determined whether this low mutation rate is a result of relatively early stage of disease or different carcinogenesis in different geographic regions.

Adenocarcinoma↗
PubMed2001

Soluble adhesion molecules and cytokines in tumor-associated tissue eosinophilia of nasopharyngeal carcinoma.

The phenomenon of tumor-associated tissue eosinophilia (TATE) is seen in some cases of nasopharyngeal carcinoma (NPC) and is characterized by the eosinophils breaking through the vascular wall and pervading the tumor stroma. The margination and trans-endothelial migration of eosinophils in a typical inflammatory reaction depend on the activating effects of certain cytokines and the expression of adhesion molecules on the eosinophils and endothelial cells. In order to investigate whether the adhesion molecules and activating cytokines play a role in eosinophil tumor infiltration, we measured the serum levels of 3 adhesion molecules, intercellular adhesion molecule-1, E-selectin and vascular cell adhesion molecule-1, and 2 cytokines, IL-3 and IL-5, in 60 NPC patients and 40 normal healthy subjects. We found that the NPC patients had higher serum levels of all three soluble adhesion molecules than the normal subjects but the levels of adhesion molecules failed to correlate with the TATE phenomenon. The levels of IL-3 and IL-5 appeared not to differ between the NPC and control groups. We postulate that the three soluble adhesion molecules do not play a major role in TATE and that their elevation in serum may be due to local and/or systemic immune responses.

Adult↗
PubMed2001

Juvenile dermatomyositis complicated with vasculitis and duodenal perforation.

Duodenal perforation has been reported in patients taking steroids and non-steroidal anti-inflammatory drugs (NSAIDs). However, its association with juvenile dermatomyositis is extremely rare. A 4-year-old boy with dermatomyositis presented with intractable abdominal pain which was aggravated after steroid and NSAID therapies. A widespread retroperitoneal abscess was noted on abdominal computerized tomography. An emergency operation showed an ulcer and perforation at the junction of the third and fourth portions of the duodenum. Debridement of the necrotic tissue and repair of the perforation were performed. The postoperative course was complicated by an anastomotic leak, which was corrected by reanastomosis. In addition to intestinal vasculitis, duodenal vasculitis complicated with ulcers and perforation should be included in the differential diagnosis of a child with juvenile dermatomyositis presenting with abdominal complaints.

Abdominal Abscess↗
PubMed2000

Epstein-Barr virus-associated gastric carcinomas: relation to H. pylori infection and genetic alterations.

BACKGROUND & AIMS: The association of Epstein-Barr virus (EBV) and gastric carcinomas (GCs) has been shown to vary among different populations and certain histological subtypes. Few studies have addressed the status of Helicobacter pylori infection and genetic alterations in these EBV-positive or -negative GCs. METHODS: Eleven gastric lymphoepithelioma-like carcinomas (LELCs) and 139 cases of common non-LELCs were evaluated for the presence of EBV DNA using polymerase chain reaction (PCR) and RNA in situ hybridization. H. pylori infection was determined by anti-H. pylori immunoglobulin G in preoperative sera. Immunostaining for p53, c-erbB-2, and E-cadherin was performed. Microsatellite instability was analyzed by PCR using 10 primers. RESULTS: EBV was detected in 11 (100%) LELCs and in 19 (13.7%) of 139 common GCs. Compared with EBV-negative GCs, gastric LELCs tended to have a relatively higher frequency of proximal location, diffuse histological subtype, p53 overexpression, and reduced E-cadherin expression but a lower frequency of lymph node metastasis, previous H. pylori infection, and c-erbB-2 overexpression. In contrast, no significant difference of clinicopathologic and genetic profiles was observed between EBV-positive non-LELC GCs and EBV-negative GCs. No correlation of microsatellite instability was found among these 3 subsets of GCs. CONCLUSIONS: Dissecting clinicopathologic characteristics and infection status of EBV and H. pylori provide additional evidence of etiological and genetic heterogeneity for GC. Distinct clinicopathologic and genetic pathways exist in gastric LELCs, in which EBV may play a more important role than H. pylori infection.

Adenocarcinoma↗
PubMed2000

Distinct clinicopathologic and genetic profiles in sporadic gastric cancer with different mutator phenotypes.

A subset of sporadic gastric cancers (GC) exhibits microsatellite instability (MSI). To define the precise role of MSI in GC, a total of 100 patients with sporadic GC were classified into three groups, i.e., high-frequency MSI (MSI-H), low-frequency MSI (MSI-L), and microsatellite stable (MSS), based on 10 microsatellite markers. Mutational analyses of TGFbetaRII, IGFIIR, BAX, MSH3, MSH6, E2F4, MSH2, MLH1, and TP53 genes, and methylation and protein expression of MLH1 and MSH2 were performed and correlated. Twenty-seven percent of GC showed MSI at least in one locus and could be further graded as MSI-H (14%) and MSI-L (13%). No clinicopathologic difference was noted between GC with MSI-L and MSS. Compared with GC with MSI-L or MSS, GC with MSI-H had a significantly higher frequency of antral location, intestinal subtype, H. pylori seropositivity, but a lower incidence of lymph node metastasis, and displayed a higher frequency of frameshift mutations of TGFbetaRII, IGFIIR, BAX, MSH3, and E2F4 genes but a lower incidence of TP53 mutations. Furthermore, hypermethylation of the MLH1 promoter was responsible for the loss of protein function in 13 of 14 MSI-H tumors. It was concluded that a specific phenotype and a distinct profile of genetic alterations exist in MSI-H GC. We speculate that epigenetic inactivation of MLH1 by methylation plays a crucial role in initiating such a pathway of carcinogenesis. In contrast, GCs with MSS and MSI-L exhibit clinicopathologic features that are distinct from MSI-H tumors and have a higher frequency of TP53 mutations, suggesting that they may evolve through an entirely different pathway.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Subungual squamous cell carcinoma: report of 2 cases.

Subungual squamous cell carcinoma (SCC) is a rare malignant tumor with an indolent course. Its etiology is unknown. It often involves the distal phalanx of the thumb or the index finger, and often presents as a chronic ulcer that is commonly misdiagnosed as chronic paronychia, pyogenic granuloma or verruca vulgaris. Approximately 150 cases of subungual SCC, including one in a Taiwanese patient, have been reported. Here, we report two cases of subungual SCC presenting as a chronic ulcer of the nail bed refractory to antibiotic treatment. One case involved the right thumb, while the other involved the right index finger. Radiographs of both cases showed an osteolytic bone lesion involving the distal phalanx. Excision biopsy revealed SCC in both cases. Both patients received amputation of the involved distal phalanx and showed no signs of reoccurrence during 5 years of follow-up. These findings suggest that all recalcitrant ulcers of the nail bed should be biopsied to facilitate early diagnosis and treatment of subungual SCC.

Carcinoma, Squamous Cell↗
PubMed1999

Strain measurements of rabbit Achilles tendons by ultrasound.

Axial components of tendons' transverse strain fields were successfully measured in vitro by ultrasound. Achilles tendons of New Zealand white rabbits were used. Tendon inflammation was simulated by artificially inducing ischemia. Strain measurements were also correlated with conventional B-mode sonograms and histological micrographs. Results showed that strain measurements had reasonable agreement with histological examinations and provided better tissue differentiation than conventional B-mode imaging. For a given tendon, the strain values corresponding to different tissue layers were easily differentiated with an elastographic contrast-to-noise ratio ranging from 17 to 43 dB. Such differences, however, were not always present in the sonograms. Therefore, ultrasonic strain imaging may be a useful tool for assessing tendon disorders during the rehabilitation process.

Achilles Tendon↗
PubMed1999

Influence of cutaneous nerves on keratinocyte proliferation and epidermal thickness in mice.

We evaluated the influence of skin innervation on the epidermis in mice. The rich innervation of skin was demonstrated by immunocytochemistry with protein gene product 9.5, a ubiquitin carboxy hydrolase. Protein gene product-immunoreactive nerve fibers were in the epidermis, subepidermal plexus, dermal nerve trunks, and nerve terminals around sweat glands. Effects of denervation on the plantar surface of the hind foot was assessed by comparing the thickness of the epidermis, which was innervated by the sciatic nerve. Within 48 h after sectioning of the sciatic nerve, protein gene product (+)-nerves in the territory of the sciatic nerve were completely degenerated. There was a significant thinning of the denervated epidermis 72 h post-transection (30.5+/-1.1 vs 41.4+/-2.9 microm, 74+/-4% of the control side). The reduction in epidermal thickness persisted when skin remained denervated (69-75% of the control side). Incorporation of bromodeoxyuridine was reduced 24 h after denervation (71+/-6% of the control side). Reduction in bromodeoxyuridine-incorporation was most pronounced within 48 h after denervation (19+/-6% of the control side). Therefore, the reduction in bromodeoxyuridine-labeling followed a similar temporal course as the thinning of the epidermis (25-50%). Both epidermal thinning and reduced bromodeoxyuridine-labeling were reversed by epidermal reinnervation three months after denervation. Patterns of keratinocyte differentiation and programmed cell death were unaffected by skin denervation. These findings are consistent with the notion that skin innervation exerts influence on the proliferation of keratinocytes and the thickness of the epidermis, and offers a new look at the interaction between nociceptive nerves and their innervated targets.

Animals↗
PubMed1999

Circulating intercellular adhesion molecule 1 (ICAM-1), E-selectin and vascular cell adhesion molecule 1 (VCAM-1) in head and neck cancer.

The sera from patients with nasopharyngeal carcinoma (n = 30), oral carcinoma (n = 22) and laryngeal carcinoma (n = 22) was extracted before treatment. The concentration of circulating intercellular adhesion molecule 1 (ICAM-1), E-selectin and vascular cell adhesion molecule 1 (VCAM-1) was measured by enzyme-linked immunoassay and compared with those from normal subjects (n = 20). The concentration of circulating ICAM-1, E-selectin and VCAM-1 was significantly increased in nasopharyngeal carcinoma. Correspondingly, VCAM-1 and E-selectin were significantly increased in laryngeal carcinoma, whereas only E-selectin was elevated in oral carcinoma. The concentrations of these adhesion molecules did not significantly differ with respect to the early and late stages of these carcinomas. Elevated levels of soluble adhesion molecules in the sera of cancer patients at three different head and neck regions, although appearing to be implicated in these tumour formations, may be unrelated to tumour progression.

Adult↗
PubMed1999

Long-term follow-up of duodenal ulcer in children before and after eradication of Helicobacter pylori.

BACKGROUND: Helicobacter pylori is a well-known cause of chronic antral gastritis and plays an important role in the pathogenesis of peptic ulcer disease in adults. However, because of the relatively low incidence of duodenal ulcer in childhood, few studies have been directed specifically at the relation between the treatment of H. pylori infection and duodenal ulcer in children. An evaluation in a larger patient population is necessary to draw a conclusion. METHODS: Twenty-six children with duodenal ulcer and H. pylori antral gastritis received triple therapy (amoxicillin, bismuth, and metronidazole) to investigate whether eradication of the organisms can promote healing and prevent relapse of the ulcers in children. Endoscopic examinations were performed before, 2 months, and 12 months after the beginning of treatment. RESULTS: H. pylori infection was eradicated in 25 (96%) of the 26 patients who underwent upper endoscopic follow-up. Clinical improvement and ulcer healing were achieved in 24 (92%) of 26 children. During a mean follow-up of nearly 2 years, the annual ulcer relapse rate was estimated to be 9%. CONCLUSIONS: Triple therapy is the treatment of choice for endoscopically proven duodenal ulcer and histologically proven H. pylori antral gastritis in children. It strongly supports a causal relation between H. pylori and duodenal ulcer disease in children.

Adolescent↗
PubMed1999

A case of extraadrenal pheochromocytoma associated with adrenal cortical nodular hyperplasia and papillary thyroid carcinoma.

A 64-year-old woman was admitted in November, 1996 for fluctuating blood pressure. There was multinodular goiter in her neck. High urine VMA and serum aldosterone were noted. Computed tomography showed an oval lesion in the left adrenal gland. Left adrenalectomy was performed and the pathology was proved to be adrenal cortical nodular hyperplasia. Fluctuating blood pressure and high urine VMA persisted after the operation. CT scan of the abdomen revealed a soft tissue mass in lower abdomen. The patient was admitted again in September, 1997. Laboratory examinations showed normal serum aldosterone, normal plasma renin activity and high urine VMA. Aspiration cytology of the thyroid gland disclosed papillary thyroid carcinoma. [131I]-metaiodobenzylguanidine image revealed a high uptake lesion in the right L-3 paravertebral area. Tumor excision and thyroidectomy were performed. The pathology was reported as extraadrenal pheochromocytoma and papillary thyroid carcinoma. Papillary thyroid carcinoma is rarely associated with pheochromocytoma. To our knowledge, this paper is the first report of a patient with extraadrenal pheochromocytoma associated with papillary thyroid carcinoma and adrenal cortical nodular hyperplasia.

Adrenal Cortex↗
PubMed1999

Regulation of vascular endothelial growth factor secretion in human meningioma cells.

Previously, we induced vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) secretion in glioma cell lines by using physiologic concentrations of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), or platelet-derived growth factor-BB (PDGF-BB). We hypothesized that VEGF/VPF might enhance the blood supply required for the unregulated growth of tumors, and that it acts as the central mediator of tumor angiogenesis. The objective of this study was to determine whether the expression of VEGF/VPF by meningiomas is regulated by growth factors or sex hormones. By means of an enzyme-linked immunosorbent assay of CH-157MN meningioma cell supernatants, we demonstrated that EGF and bFGF similarly induce VEGF secretion by CH-157MN meningioma cells. At the maximum concentrations of EGF (50 ng/mL) and bFGF (50 ng/mL) used in this study, VEGF secretion was induced to 140% to 160% above baseline constitutive secretion. PDGF-BB homodimer did not enhance VEGF secretion significantly. Estradiol (up to 10(-7) mol/L), progesterone (up to 10(-5) mol/L), or testosterone (up to 10(-5) mol/L) did not stimulate or inhibit VEGF secretion in CH-157MN meningioma cells (p > 0.05). Furthermore, we demonstrated that dexamethasone decreased VEGF secretion to 32% of baseline constitutive secretion. This might explain the effect of corticosteroids in alleviating peritumoral brain edema in meningiomas. These results suggest that VEGF secretion in CH-157MN meningioma cells is mainly regulated by growth factors and corticosteroids, but not by sex hormones. Understanding the regulation of VEGF/VPF secretion in meningiomas might contribute to the development of a new therapeutic strategy.

Dexamethasone↗