A hypoxia-dependent upregulation of hypoxia-inducible factor-1 by nuclear factor-κB promotes gastric tumour growth and angiogenesis

BACKGROUND

The underlying mechanisms involved in the activation of hypoxia-inducible factor-1 (HIF-1) in gastric cancer remain unclear. As nuclear factor-κB (NF-κB) as well as HIF-1 have been implicated in angiogenesis of various cancers, we investigated their relationship in gastric cancer.

METHODS

Nuclear expressions of HIF-1α and NF-κB/RelA were assessed in 251 human gastric carcinoma specimens by immunohistochemical tissue array analysis. Stable human gastric cancer cells, infected with a retroviral vector containing super-suppressive mutant form of IκBα (IκBαM), were used for animal studies as well as cell culture experiments. Xenografted tumours were measured and IκBαM effects on angiogenesis and HIF-1α activation were assessed by immunohistochemistry, western blotting, luciferase reporter assay, and semiquantitative reverse transcription-polymerase chain reaction. In addition, NF-κB effects on the HIF-1α degradation and synthesis were examined.

RESULTS

Hypoxia-inducible factor-1α activation positively correlated with RelA activation in clinical gastric cancer samples (P<0.001). The IκBαM overexpression suppressed tumour growth, microvessel density, and HIF-1α activation in xenografted tumours. Cell culture experiments showed that hypoxia-induced HIF-1α expression was reduced by NF-κB inhibition under hypoxic conditions at the translational level.

CONCLUSION

The hypoxia-dependent activation of the NF-κB/HIF-1α/VEGF pathway contributes, at least in part, to gastric cancer promotion via enhancement of angiogenesis.

Validation of limited lymphadenectomy for lower-third gastric cancer based on depth of tumour invasion

BACKGROUND

This study aimed to determine the appropriate extent of lymph node (LN) dissection in gastric cancer by analysing LN metastasis patterns from prospectively collected topographical data on nodal status at Seoul National University Hospital, Korea.

METHODS

The metastasis rate for each LN station was analysed according to the depth of tumour invasion in patients with primary lower-third gastric cancer who underwent curative gastrectomy. The Maruyama Index of unresected disease (MI) was calculated using the WinEstimate(®) program with simulation of various extents of LN dissection.

RESULTS

LN metastasis in mucosal cancer was rare; 2·6 per cent of patients had a MI of more than 5 with simulation of D1 plus station 7 dissection, whereas 0·9 per cent had a MI above 5 with D1 plus stations 7 and 8a. In submucosal cancer, 3·3 per cent of tumours metastasized to level 2 LN stations outside the range of D1 plus stations 7, 8a and 9. The proportion of patients with a MI above 5 was 9·0 per cent with D1 plus stations 7, 8a and 9 dissection. The nodal metastasis rate was higher at level 1 and 2 for muscularis propria or deeper cancers.

CONCLUSION

D1 dissection plus stations 7 and 8a for mucosal cancer, and D2 dissection for cancers of the muscularis propria or deeper seems appropriate. For submucosal cancer, an expanded dissection to the D2 level should be considered to ensure complete removal of metastatic LNs.

Ternary complex formation of Eu(III) with o-phthalate in aqueous solutions

Ternary hydroxo complex formation of Eu(III) with o-phthalate was investigated by potentiometry and fluorescence spectrophotometry. Curves of the equilibrium pH versus the amount of NaOH added showed that the pH value starting to form a Eu(III) precipitate was decreased due to the formation of a ternary hydroxo complex, EuOHL(s) (L = phthalate). The formation of EuOHL(s) was qualitatively confirmed by the enhancement of the fluorescence intensity of Eu(III) in the precipitate with the light absorbed by phthalate, and was quantitatively confirmed by the measurement of the amounts of Eu(III), OH(-) and phthalate included in the precipitate. The solubility product of EuOHL(s) was determined as pK(sp)(0) = 15.6+/-0.4. Characteristic features in the fluorescence spectra and the solubility product of the Eu(III)-phthalate complex were compared with those of the Eu(III)-PDA (PDA = pyridine-2,6-dicarboxylate) complex. The fluorescence intensity of the EuL(+) complex of L = PDA was about 11 times stronger than that of L = phthalate. The origin of the difference in the fluorescence intensity is discussed based on the intramolecular energy transfer effect from the lowest triplet energy level of the ligand to the resonance energy level of Eu(III).

Phase II study and biomarker analysis of cetuximab combined with modified FOLFOX6 in advanced gastric cancer

This prospective study was conducted with the Korean Cancer Study Group to evaluate the efficacy and safety of cetuximab combined with modified FOLFOX6 (mFOLFOX6) as first-line treatment in recurrent or metastatic gastric cancer and to identify potential predictive biomarkers. Patients received cetuximab 400 mg m⁻² at week 1 and 250 mg m⁻² weekly thereafter until disease progression. Oxaliplatin (100 mg m⁻²) and leucovorin (100 mg m⁻²) were administered as a 2-h infusion followed by a 46-h continuous infusion of 5-fluorouracil (2400 mg m⁻²) every 2 weeks for a maximum of 12 cycles. Biomarkers potentially associated with efficacy were analysed. Among 38 evaluable patients, confirmed response rate (RR) was 50.0% (95% CI 34.1–65.9). Median time-to-progression (TTP) was 5.5 months (95% CI 4.5–6.5) and overall survival (OS) 9.9 months. Eleven patients having tumour EGFR expression by immunohistochemistry with low serum EGF and TGF-α levels showed a 100% RR compared to 37.0% in the remaining 27 patients (P<0.001). Moreover, ligand level increased when disease progressed in seven out of eight patients with EGFR expression and low baseline ligand level. No patient exhibited EGFR amplification or K-ras mutations. Gastric cancer patients with EGFR expression and low ligand levels had better outcomes with cetuximab/mFOLFOX6 treatment.

Differential diagnosis of intestinal Behçet's disease and Crohn's disease by colonoscopic findings

BACKGROUND AND STUDY AIMS

Intestinal Behçet's disease and Crohn's disease are chronic inflammatory bowel diseases that are difficult to distinguish from each other. We investigated their colonoscopic features and identified simple and valuable strategies for differential diagnosis.

PATIENTS AND METHODS

Between 1995 and 2006, 250 consecutive patients with ulcers on colonoscopy (115 Behçet's, 135 Crohn's cases) were reviewed. All patients with Behçet's fulfilled the criteria of the International Study Group for Behçet's Disease or of the Behçet's Disease Research Committee of Japan, while Crohn's disease was confirmed by clinicopathological data. Patients were randomly allocated to a training set (70 %) or a validation set (30 %). Ulcer shapes, distributions, numbers, margins, and border contours, and the presence of aphthous, cobblestone, perianal, and strictured lesions were compared, in the training set. Univariate and multivariate analysis were performed, using the X2-test and logistic regression. In addition, a classification and regression tree (CART) was then used to generate simplified algorithms for differential diagnosis.

RESULTS

Round shape, five or fewer in number, focal distributions, and absence of aphthous and cobblestone lesions were significantly dominant features in Behçet's disease, according to multivariate analysis of the training set. The CART-generated algorithms proposed sequential use of shape (round, irregular/geographic, or longitudinal) and distribution (focal single/focal multiple, or segmental/diffuse). Diagnosis of Behçet's disease in the validation set produced sensitivity, specificity, and negative and positive predictive values of 94.3 %, 90.0 %, 94.7 %, and 89.2 %, respectively. Using the CART model, we made the correct diagnosis of intestinal Behçet's disease or Crohn's disease in 69 of 75 patients (92 %).

CONCLUSION

It was determined that round and longitudinal ulcers are suggestive of Behçet's disease and Crohn's disease, respectively. Irregular/geographic-shaped ulcers and focal distributions are suggestive of Behçet's disease, while segmental/diffuse lesions suggest Crohn's.

Prognostic implications of type and density of tumour-infiltrating lymphocytes in gastric cancer

The study aims to determine whether type and density of tumour-infiltrating lymphocytes (TILs) can predict the clinical course in gastric cancer. Gastric carcinomas (n=220) were immunostained for CD3, CD8, CD20, and CD45RO and evaluated for clinicopathologic characteristics. Number of TILs that immunostained positively for each marker were counted using NIH ImageJ software. Tumours were grouped into low- and high-density groups for each marker (CD3, CD8, CD45RO). The densities of CD3(+), CD8(+), and CD45RO(+) TILs were found to be independent predictors of lymph node metastasis by multivariate analysis with odds ratios (95% CI) of 0.425 (0.204-0.885), 0.325 (0.150-0.707), and 0.402 (0.190-0.850), respectively. Kaplan-Meier survival analysis revealed that patients in the high-density groups for CD3, CD8, and C45RO had a significantly longer survival time than the patients in the corresponding low-density groups, respectively. In multivariate survival analysis, the densities of CD3(+), CD8(+), and CD45RO(+) TILs remained independent prognostic factors with hazard ratios (95% CI) of 0.549 (0.317-0.951), 0.574 (0.347-0.949), and 0.507 (0.298-0.862), respectively. In conclusion, density of TILs was found to be independently predictive of regional lymph node metastasis and patient survival in gastric cancer.

EGFR in gastric carcinomas: prognostic significance of protein overexpression and high gene copy number

AIMS

Epidermal growth factor receptor (EGFR) expression has been observed in a variety of solid tumours with the potential of new targeted therapeutic agents. The aim was to evaluate the EGFR status of gastric carcinoma (GC) using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH).

METHODS AND RESULTS

The EGFR status was evaluated in GC tissues from 511 patients using IHC and FISH. In addition, the clinicopathological characteristics were examined and the results were compared with the EGFR status. One hundred and forty cases (27.4%) showed EGFR overexpression by IHC. EGFR overexpression was associated with older age (P = 0.001), moderately or poorly differentiated histology (P = 0.001) and higher stage disease (P = 0.046). Sixteen cases (3.1%) showed high polysomy and 12 cases (2.3%) had gene amplification by FISH. The correlation between IHC and FISH results was statistically significant (P < 0.001). The patients with GC who had EGFR overexpression had an unfavourable prognosis and multivariate analysis showed that EGFR overexpression was a possible independent unfavourable prognostic factor.

CONCLUSIONS

EGFR overexpression was observed in a subset of cases with GC and was associated with an unfavourable prognosis. It will be important to evaluate EGFR status to interpret future clinical trials properly using EGFR targeted agents.

Characteristics of KIT-negative gastrointestinal stromal tumours and diagnostic utility of protein kinase C theta immunostaining

AIMS

To characterise KIT-negative gastrointestinal stromal tumours (GISTs) clinically, pathologically, immunohistochemically and genetically, and to establish the usefulness of protein kinase C theta (PKC) as a diagnostic marker in KIT-negative GIST.

METHODS

252 consecutive cases of GIST were evaluated for clinicopathological characteristics and immunostained for various antibodies. Mutational analyses of KIT and platelet-derived growth factor receptor alpha (PDGFRA) were also performed in 62 cases.

RESULTS

20 (7.9%) GISTs showed negative immunostaining for KIT. KIT-negative GISTs were more likely to originate from omentum or peritoneum, have an epithelioid histology, and be classified as high risk. The overall survival rate of patients with KIT-negative GISTs (5-year survival rate 68.7% (SD 10.7%)) was lower than that of patients with KIT-positive GISTs (5-year survival rate, 79.9% (3.0%)) (p = 0.042, log-rank test). Negative KIT expression was an independent prognostic factor in multivariate Cox regression analysis when the risk of aggressive behaviour and the status of imatinib treatment were adopted as covariates. KIT-negative GISTs also showed lower expression rates of CD34, Bcl-2, and PKC than KIT-positive GISTs; mutational analysis revealed that 30% of KIT-negative GISTs harboured a PDGFRA exon 18 mutation. Immunostaining on PKC showed that 93.9% of all GISTs expressed PKC protein. However, 21.9% of 64 mesenchymal tumours other than GIST also showed positivity on PKC.

CONCLUSIONS

KIT-negative GISTs had characteristics that differ from those of KIT-positive GISTs, and negative KIT expression was an independent prognostic indicator for overall survival of patients. Although PKC is a sensitive diagnostic marker for GIST, its usefulness is limited because of low sensitivity and low specificity in KIT-negative GISTs.

Cyclooxygenase-2 expression in human thyroid disease

OBJECTIVES

Cyclooxygenase (COX)-2, which is the inducible form of the COX enzyme for prostaglandin synthesis and a key mediator of epithelial cell growth, has been shown to be up-regulated in gastrointestinal cancers. Additionally, regular intake of other non-steroidal anti-inflammatory drugs (NSAID) is known to decrease the incidence of these cancers. Therefore, the goals of the present study were to determine the possible involvement of COX-2 in human thyroid diseases.

METHODS

We used immunohistochemical staining and Western blot analysis to characterize the expression of COX-2 proteins in thyroid tissues from 64 patients with thyroiditis, benign tumors, and malignant tumors with or without metastasis. Immunoreactivity scores were calculated by multiplication of the determined grades.

RESULTS

COX-2 proteins were not expressed in normal thyroid tissues. However, each type of tumor tissue showed intense bands of COX-2 protein expression in Western blot analyses, and the immunoreactivity scores were 7.67+/-1.17 (SD) for thyroiditis, 7.87+/-0.9 for benign tumors, 7.53+/-1.53 for follicular cancer, 7.63+/-1.11 for papillary cancer without metastasis, and 7.17+/-1.55 for papillary cancer with metastasis. No significant differences were found in the levels of COX-2 expression between different tumor tissue types.

CONCLUSION

No significant correlations were observed between clinical and/or pathological characteristics of thyroid tumors and the intensity of COX-2 protein expression. In addition, we found no difference in COX-2 protein expression between thyroiditis and thyroid tumors. Thus, up-regulation of COX-2 protein synthesis in human thyroid diseases does not appear to be of clinical significance.

Characterization of mid-infrared single mode fibers as modal filters

We present a technique for measuring the modal filtering ability of single mode fibers. The ideal modal filter rejects all input field components that have no overlap with the fundamental mode of the filter and does not attenuate the fundamental mode. We define the quality of a nonideal modal filter Q(f) as the ratio of transmittance for the fundamental mode to the transmittance for an input field that has no overlap with the fundamental mode. We demonstrate the technique on a 20 cm long mid-infrared fiber that was produced by the U.S. Naval Research Laboratory. The filter quality Q(f) for this fiber at 10.5 microm wavelength is 1000+/-300. The absorption and scattering losses in the fundamental mode are approximately 8 dB/m. The total transmittance for the fundamental mode, including Fresnel reflections, is 0.428+/-0.002. The application of interest is the search for extrasolar Earthlike planets using nulling interferometry. It requires high rejection ratios to suppress the light of a bright star, so that the faint planet becomes visible. The use of modal filters increases the rejection ratio (or, equivalently, relaxes requirements on the wavefront quality) by reducing the sensitivity to small wavefront errors. We show theoretically that, exclusive of coupling losses, the use of a modal filter leads to the improvement of the rejection ratio in a two-beam interferometer by a factor of Q(f).

The fate of implanted autologous chondrocytes in regenerated articular cartilage

Autologous chondrocyte implantation (ACI) is used to treat some articular cartilage defects. However, the fate of the cultured chondrocytes after in-vivo transplantation and their role in cartilage regeneration remains unclear. To monitor the survival and fate of such cells in vivo, the chondrocytes were labelled with a lipophilic dye and the resultant regenerated tissue in dogs examined. It was found that, 4 weeks after implantation, the osteochondral defects were filled with regenerative tissue that resembled hyaline cartilage. Fluorescence microscopy of frozen sections of the regenerated tissue revealed that the majority of cells were derived from the DiI-labelled implanted chondrocytes. From these results, it was concluded that a large population of implanted autologous chondrocytes can survive at least 4 weeks after implantation and play a direct role in cartilage regeneration. However, it remains unknown whether other cells, such as periosteal cells or bone marrow stromal stem cells, are involved in the regeneration of cartilage after ACI.

Clinical significance of anti-Saccharomyces cerevisiae antibody (ASCA) in Korean patients with Crohn's disease and its relationship to the disease clinical course

BACKGROUNDS/AIMS

The implications of anti-Saccharomyces cerevisiae antibody for the diagnosis and the clinical course of Crohn's disease have been reported in Western countries, but rarely in Korea with its very different environmental and genetic backgrounds. We aimed to evaluate whether anti-S. cerevisiae antibody expression is associated with diagnostic findings, stratified Vienna classification phenotypes, disease activity and clinical course in Korean patients with Crohn's disease.

MATERIALS/METHODS

One hundred and fifteen patients with Crohn's disease, diagnosed and treated between 1990 and 2004 at Severance Hospital, Yonsei University and followed for at least 2 years, were included in this study. Anti-S. cerevisiae antibody was detected by an indirect immunofluorescence assay using EUROIMMUN kits. Information collected during treatment included demography, Vienna classification phenotype, clinical manifestation, laboratory tests, treatment modality and surgery rate. Disease activity was measured monthly using the Harvey-Bradshaw index.

RESULTS

The anti-S. cerevisiae antibody prevalence was 38.3% in Crohn's disease patients. There was no difference in anti-S. cerevisiae antibody expression between genders. The mean age at diagnosis was younger for the anti-S. cerevisiae antibody positive group than the negative group (25.3 years versus 29.7 years, p<0.05). Clinical manifestations and laboratory tests at diagnosis did not differ between the groups. The anti-S. cerevisiae antibody positive group had increased fibrostenosis (B2) and penetration (B3) compared to negative group, as determined by the Vienna classification (75.0% versus 53.5%, p<0.05). Anti-S. cerevisiae antibody positive patients were admitted to the hospital more frequently than anti-S. cerevisiae antibody negative patients (p<0.05). The yearly cumulative Harvey-Bradshaw index score was higher in the anti-S. cerevisiae antibody positive group than in the negative group during the follow-up period (p<0.05). In addition, steroid (72.7% versus 52.1%, p<0.05) and immunosuppressive (45.5% versus 23.9%, p<0.05) treatments were more frequently given to the anti-S. cerevisiae antibody positive group.

CONCLUSIONS

Our data demonstrate that anti-S. cerevisiae antibody positive Crohn's disease patients had a more severe clinical course and thus often required more aggressive medical treatment.

Study of an alpha track analysis and a fission track analysis for determining the hot particles contaminated with Pu and U isotopes

A fission track analysis and alpha track analysis were developed to detect fissile particles such as uranium and plutonium isotopes as well as to identify particle-bound plutonium in contaminated soil or sediment. To record a reference point, a locator SEM grid electroplated with boron was used to obtain a recorded grid image on the Lexan or CR-39 detector. With the fission track technique, the track images of the grid coated with boron and the fissile nuclides on the CR-39 detector were clearly recorded so that the location of the fissile particles could be easily identified in the radio-contaminated soil matrix. With the alpha track technique, many of the hot particles in the BOMARC soil turned out to be contaminated with plutonium isotopes rather than uranium isotopes.

Prevalence of and risk factors for extracranial internal carotid artery stenosis in Korean Type 2 diabetic patients

AIMS

The objectives of this study were to evaluate the prevalence of and risk factors for extracranial internal carotid artery stenosis in Type 2 diabetic patients.

METHODS

This study included 406 patients aged 40-79 years with Type 2 diabetes (male 55.4%, female 44.6%). Both carotid arteries of each patient were examined by carotid duplex scanning. The duplex ultrasound criteria based on the North American Symptomatic Carotid Endarterectomy Trial (NASCET) measurement method were used for the identification of carotid stenosis.

RESULTS

Extracranial internal carotid artery stenosis >or= 40% by velocity criteria was detected in 5.2% of the patients. The prevalence of carotid stenosis increased with advancing age: 1.0% at 40-49 years of age, 5.0% at 50-59 years, 7.3% at 60-69 years and 9.5% at 70-79 years. The degree of stenosis was > 70% in 42.9% of patients with stenosis, Bilateral stenosis was detected in 14% of patients. Of the patients with >or= 40% carotid stenosis, 33% had a decreased ankle-brachial index, 38% had a previous history of stroke, and only one patient (5%) had a documented history of coronary artery disease. Multivariate analysis, including variables determined to be significantly different by univariate analysis between patients with or without >or= 40% stenosis, indicated that age, systolic blood pressure and high-density lipoprotein (HDL)-cholesterol (inverse correlation) were independent risk factors associated with carotid stenosis.

CONCLUSIONS

Carotid duplex scanning is a useful strategy in identifying carotid stenosis in older Type 2 diabetic patients with high systolic blood pressure, or low levels of HDL cholesterol. The early identification and subsequent appropriate management of carotid stenosis, particularly in this group of patients, may facilitate efforts to reduce the incidence of macrovascular complications.

Radiation protects adriamycin-induced apoptosis

Combined radiotherapy and chemotherapy have represented major advance in the therapeutic management of cancer therapy. Anthracycline antineoplastic agents are limited by a high incidence of severe and usually irreversible cardiac toxicity, the cause of which remains controversial. When the primary cardiomyocytes isolated from neonatal rats were preirradiated by gamma-ray, the cells were highly resistant to adriamycin-induced apoptosis. This study shows that irradiation inhibited apoptosis by enhancing Bcl-2, attenuating Bax induction, and preventing collapse of mitochondrial membrane potential (delta psi), cytochrome c release into cytoplasm and caspase-3, -6 and -9 activations. In addition, the preirradiation stimulated the activity of manganese-superoxide dismutase (Mn-SOD) and the expression of Mn-SOD mRNA and protein. Adriamycin decreased Mn-SOD activity but did not change the activity of copper/zinc (Cu/Zn)-SOD under either pre- or nonirradiated condition. Phosphothioate-linked antisense against Mn-SOD, which specifically knocked down the activity of Mn-SOD but not that of Cu/Zn-SOD, reversed irradiation-induced protective effect in adriamycin-exposed cardiomyocytes. These data suggest that the irradiation-induced expression of Mn-SOD plays an important role in irradiation-mediated protection in adriamycin-exposed rat ventricular cardiomyocytes.

Expression of Lewis antigens and their precursors in gastric mucosa: relationship with Helicobacter pylori infection and gastric carcinogenesis

Lewis (Le)-associated antigens are carbohydrates that are related biochemically to the ABO blood groups, and may have a role in Helicobacter pylori adherence. To evaluate their relationship to clinicopathological outcomes, gastric Le expression, including type 1 precursor, type 1 H, Le(a), Le(b), Le(x), Le(y) and sialylated Le(a) (CA19-9), was evaluated immunohistochemically in 233 gastric biopsy specimens obtained at routine gastroscopy. Expression was also investigated in gastric tissues showing chronic gastritis, intestinal metaplasia, and carcinoma from 42 patients with gastric cancer. A polymerase chain reaction was performed for H. pylori and the bacterial babA2 gene. We identified type 1 precursor expression in 34.3%, type 1 H in 55.8%, Le(a) in 44.2%, Le(b) in 82.0%, Le(x) in 44.2%, Le(y) 56.7%, and CA19-9 in 16.3% of the 233 gastric biopsy specimens. Expression of type 1 H, Le(b), and CA19-9 was significantly associated with H. pylori infection and histological features (p < 0.05), and expression of type 1 H was an independent predictive factor for H. pylori infection by multivariate logistic regression (p = 0.020). Positivity for the babA2 genotype correlated significantly with H. pylori infection and type 1 H expression in gastric biopsy specimens (p < 0.05). The babA2 genotype was more frequent in gastric mucosa from the gastric cancer patients than in gastric biopsy specimens from routine gastroscopy (p = 0.009). In the 42 gastric cancer patients, the frequency of type 1 precursor, Le(a), and Le(x) expression was significantly higher in intestinal metaplasia and carcinoma than in chronic gastritis (p < 0.05), but the frequency of type 1 H and Le(b) expression was significantly lower in intestinal metaplasia and carcinoma (p < 0.05). In conclusion, Le expression, especially that of type 1 H, was significantly associated with clinicopathological features. In gastric cancer patients, Le expression was altered in intestinal metaplasia and carcinoma in comparison with chronic gastritis.

Diagnostic yield of advanced colorectal neoplasia at colonoscopy, according to indications: an investigation from the Korean Association for the Study of Intestinal Diseases (KASID)

BACKGROUND AND STUDY AIMS

The factors that more accurately predict the detection of colorectal cancers and adenomas at colonoscopy are different. We conducted a prospective multicenter study to evaluate which indications were most closely associated with advanced colorectal neoplasm (CRN), including colorectal cancer, in a group of patients undergoing colonoscopy.

PATIENTS AND METHODS

The 17 468 patients were enrolled in this study between July 2003 and March 2004, from 11 tertiary medical centers in Korea. They were recruited according to 11 itemized colonoscopic indications. The term "advanced adenoma" refers here to tubular adenomas of diameter of 11 mm or more, or to tubulovillous, villous, or severely dysplastic adenomas, irrespective of their size. Cancer was defined as the invasion of malignant cells beyond the muscularis mucosa. Advanced CRN was defined as advanced adenoma or invasive cancer.

RESULTS

Advanced CRN was found in 1227/17 307 patients (1176 advanced adenomas plus 51 carcinomas, 7.1 %). According to univariate and multivariate analysis, the factors associated with advanced CRN included age >60 years (odds ratio (OR) 2.1, 95 % confidence interval (CI) 1.8 - 2.4, P < 0.0001), male gender (OR 2.1, 95 %CI 1.7 - 2.7, P < 0.0001), referral for colonoscopy from primary care physician (OR 3.1, 95 %CI 2.5 - 3.7, P < 0.0001), and several other indications (OR 1.8, 95 %CI 1.5 - 2.3, P < 0.001). The yield of colonoscopy for advanced CRN was lower (2.2 %) than expected in patients with iron-deficiency anemia (OR 0.5, 95 %CI 0.2 - 0.9, P = 0.03).

CONCLUSIONS

Age, gender, and referral for colonoscopy from primary care physician constituted important independent predictors of advanced CRN in patients undergoing colonoscopy.

Outcome after one-stage repair of tetralogy of Fallot

AIM

The purpose of this study was to evaluate the outcome after one-stage repair of tetralogy of Fallot (TOF).

METHODS

Between May 1997 and December 2002, 240 patients with a median age of 9 months (1 month-48 years) underwent one-stage repair of TOF. Closure of ventricular septal defect (VSD) was accomplished through the right atrium in 171 (71.3%) patients and through the right ventricle in 69 (28.7%) patients. For the reconstruction of the right ventricular outflow tract (RVOT), transannular repair was performed in 151 (62.9%) patients, and non-transannular repair was performed in 89 (37.1%) patients. Follow-up was complete, averaging 40+/-17.6 months (3 months-5.8 years).

RESULTS

There were 2 (0.8%) operative deaths. Between early repair group (age under 6 months) and late repair group (age above 6 months), there were no differences in the method of RVOT reconstruction (transannular vs non-transannular) and the need for branch pulmonary artery angioplasty. Early repair group had more transventricular VSD closure than late repair group (46% vs 22%, P < 0.05). Duration of inotropic support and intensive care unit (ICU) stay were longer in the early repair group (P < 0.05). Five patients required reoperations due to RVOT obstruction (n = 3), and residual VSD (n = 2). Kaplan-Meier freedom from reoperation at 5 years was 98.3+/-1%. Nine patients underwent catheter intervention for branch pulmonary artery stenosis. Freedom from reintervention at 5 years was 95.4+/-1.5%. All survivors are currently asymptomatic.

CONCLUSIONS

One-stage repair of TOF could be performed with low mortality and morbidity. Especially, early one-stage repair in symptomatic infant could be performed with low risk, eliminating the need for palliative procedures.

Primary colon lymphoma in Korea: a KASID (Korean Association for the Study of Intestinal Diseases) Study

Although almost all primary colorectal lymphomas are of B-cell lineage in Western countries, primary colorectal T-cell lymphomas are not uncommon in the East. The aim of this study was to review the clinical characteristics and treatment outcomes of primary colorectal lymphomas, with special emphasis on the differences between T-cell and B-cell lymphomas. Ninety-five cases of primary colorectal lymphomas that satisfied Dawson's criteria were identified from the clinical databases of 13 university hospitals in Korea. The mean age at the time of presentation was 51.1 years and the male:female ratio was 64:31. The clinical information, including endoscopic and histological characteristics, was retrospectively analyzed. Of the primary colorectal lymphomas, 78 cases (82.1%) were of B-lineage and 17 cases (17.9%) were of T-cell lineage. Patients with T-cell lymphomas presented at a younger age than patients with B-cell lymphomas (42.8 vs 52.9 years, respectively; P = 0.016). The most common presenting symptom was abdominal pain (87.1%) for B-cell lymphomas, whereas hematochezia or night fever was more common for T-cell lymphomas (52.9% and 35.3%, respectively). The most common endoscopic type was fungating mass (54.0%) for B-cell lymphomas and ulcerative/ulcero-infiltrative lesions (80.0%) for T-cell lymphomas. Intussusception was more common in B-cell lymphomas than in T-cell lymphomas (30.8% vs 5.9%, respectively; P = 0.035), but perforation was more common in T-cell lymphomas than in B-cell lymphomas (23.5% vs 3.8%, respectively; P = 0.005). The prognosis was significantly worse for T-cell lymphomas than for B-cell lymphomas (P = 0.002). Primary colorectal T-cell lymphomas are characterized by multifocal ulcerative lesions in relatively young patients, a high rate of hematochezia, fever, or perforation, and a poor prognosis even for cases of localized disease.

Sentinel node biopsy for cT1 and cT2a gastric cancer

AIMS

To evaluate the feasibility and accuracy of sentinel node (SN) biopsy for gastric cancer.

PATIENTS AND METHODS

One hundred patients with gastric cancer diagnosed as cT1 (n=80) or cT2a (n=20) were enrolled. Indocyanine green-stained SNs were analysed by hematoxylin and eosin staining (n=100) and by cytokeratin immunohistochemistry (n=50).

RESULTS

SNs were identified in 94 of the 100 patients and the mean number of SNs was 4.4 (range, 1-12). Of these 94 patients, 14 patients had lymph node metastases. Two patients with T1 and one patient with T2 had metastases in non-SNs alone by hematoxylin and eosin staining (diagnostic accuracy =97.3% in T1 and 95.0% in T2). All three patients with a false negative result had a tumour, which was more than 4 cm in size and signet ring cell histology. In two of them, the tumour was located at lesser curvature. By immunohistochemical staining, three patients with T1 and one patient with T2 were found to have lymph node micrometastases in non-SNs alone among 45 patients (diagnostic accuracy =92.1% in T1, 85.7% in T2).

CONCLUSION

SN biopsy using indocyanine green can be performed rapidly and easily with a high detection rate and accuracy in patients with T1 gastric cancer. However, it should be performed with caution for large tumours with a signet ring cell histology located at lesser curvature due to the possibility of a false negative result.

Expression and prognostic implications of cell cycle regulatory molecules, p16, p21, p27, p14 and p53 in germinal centre and non-germinal centre B-like diffuse large B-cell lymphomas

AIMS

To evaluate the different expression patterns and the prognostic significance of cell cycle regulatory molecules in diffuse large B-cell lymphomas (DLBCLs) of germinal centre (GC) and non-GC phenotypes.

METHODS AND RESULTS

Tissue microarray slides composed of 126 extranodal and 88 nodal DLBCLs were immunostained for p16, p21, p27, p14 and p53. DLBCLs were classified into GC and non-GC phenotype according to the immunohistochemical expression of bcl-6, CD10, and MUM1. Aberrant expression of p53 was more frequent in the GC phenotype in nodal cases (P = 0.038), and the loss of p16, p21 and p14 expression was significantly more common in the non-GC phenotype (P = 0.004, P = 0.001, P < 0.001). Concurrent disruptions of the p16-Rb and p14-p53 pathways as represented by the immunoprofile of p16/p14/p53 (-/-/+) were associated with a poor prognosis in the GC phenotype [mean survival 31 months in the p16/p14/p53 (-/-/+) group versus 62 months in the other groups, P =0.0485].

CONCLUSIONS

The expression and prognostic implications of cell cycle regulatory molecules differ between GC and non-GC phenotypes in DLBCLs. The immunoprofile of p16/p14/p53 (-/-/+) within the GC phenotype of DLBCLs can be defined as a poor prognostic subgroup.

Epstein-Barr virus plays little role in cervical carcinogenesis in Korean women

We examined whether Epstein-Barr virus (EBV) infection plays a role in cervical carcinogenesis in Korean women. EBV infection was examined using polymerase chain reaction (PCR) with two different primer pairs flanking the BamHI "W" fragment of EBV and by EBV-encoded small RNAs (EBER) in situ hybridization in various histologic types of cervical cancer, including 17 cases of squamous cell carcinoma, 36 cases of adenocarcinoma, and 3 cases of small-cell carcinoma. We also evaluated 20 cases of cervical intraepithelial neoplasia and 20 cases of normal uterine cervix. One case of squamous cell carcinoma and three cases of cervical intraepithelial neoplasia were positive for EBV DNA using PCR, but EBER in situ hybridization analysis showed that none of the PCR-positive cases expressed EBER. EBV DNA was not found using PCR in any of the 20 normal uterine cervices. From our results, EBV infection does not seem to play a role in cervical carcinogenesis in Korean women.

Comparison of Central Venous Catheterization Sites in Infants

This study aimed to compare the rates of success and complications between different sites of central venous catheterization in infants. A total of 272 infants were randomized to four groups: right subclavian group (G-RSCV), right internal jugular group (G-RIJV), left subclavian group (G-LSCV) and left internal jugular vein group (G-LIJV). In 77.2% of the patients, we successfully introduced a catheter at the first attempt. The rate of successful catheter placement was highest in the RIJV (RIJV 89.7%, LIJV 79.4%, RSCV 66.2% and LSCV 55.9%). With regard to complications, the rate of arterial puncture, guide wire advancement failure and malpositioning of the catheter were all significantly more frequent during SCV catheterization (SCV versus IJV: 10.1% versus 2.1%, 12.4% versus 0% and 13.4% versus 0.6%, respectively). Our results imply that IJV, especially RIJV, should be the first choice for central venous catheterization in infants.

Prognostic significance of the expression of Smad4 and Smad7 in human gastric carcinomas

BACKGROUND

Transforming growth factor-beta (TGF-beta) modulates the growth and function of many cells, including those with malignant transformation. Smad proteins have been identified as major components in the intracellular signaling of TGF-beta family members.

PATIENTS AND METHODS

To clarify the correlations between clinicopathologic profiles and the patient's survival, the expression of common mediator Smad (Smad4) and inhibitory Smad (Smad7) were evaluated immunohistochemically in 304 consecutive gastric carcinomas using the tissue array method.

RESULTS

Positive Smad4 expression was observed in 266 (87.5%) tumors and positive Smad7 expression in 98 (32.2%) tumors. The prognosis of patients with a Smad4-positive tumor was significantly better than that of the patients with a negative tumor. The survival rate was significantly higher in patients with negative Smad7 expression than those with positive Smad7 expression. In subgroup analysis according to TNM (tumour-node-metastasis) stage, both Smad4 and Smad7 showed most significant prognostic differences in stage I gastric cancer patients. Multivariate analysis indicated that tumor size, depth of invasion, lymph node metastasis and Smad7 expression were independent prognostic factors.

CONCLUSION

Enhanced expression of the TGF-beta signaling inhibitor Smad7 may present one of the novel mechanisms of TGF-beta resistance in human gastric carcinomas.