[Additional polyp detection rate using colonoscopic retroflexion in right colon]

BACKGROUND/AIMS

There have been several studies showing that retroflexion (RF) in the right colon (RC) could reduce the polyp miss rate of proximal colon during colonoscopy. This study was conducted to evaluate the additional benefit of RF technique in the RC.

METHODS

Patients who underwent colonoscopy from May 2008 to April 2011 were enrolled in the study. Data were obtained by retrospectively reviewing the medical records. RF was attempted in every patients undergoing colonoscopy since May 2008 except in cases of small RC vault, co-morbidity, severe diverticulosis, failed RF despite two trials, complaints of severe abdominal pain, or time burden. At first, RC was examined under direct vision. It was then examined by RF to detect missed polyps during the initial observation. Finally, the RC was re-examined with direct view.

RESULTS

The cumulative RF success rate in the RC was 78.84% (1,805 of 2,319). The RF success rate increased with the number of cases (50% at 160 cases, 70% at 400 cases, and reached near 90% over 1,000 cases). Few polyps (4.88%) were detected only with RF and the additional adenoma detection rate was 3.32%. The additional polyp/adenoma detection rates were higher in the old age group (p<0.01). There were no RF associated perforation or severe complication.

CONCLUSIONS

Using RF examination, additional 4.88% of polyps could be detected in the RC. This technique could be a useful and safe method to detect hidden polyp during colonoscopy.

Regression of esophageal varices and splenomegaly in two patients with hepatitis-C-related liver cirrhosis after interferon and ribavirin combination therapy

Some recent studies have found regression of liver cirrhosis after antiviral therapy in patients with hepatitis C virus (HCV)-related liver cirrhosis, but there have been no reports of complete regression of esophageal varices after interferon/peg-interferon and ribavirin combination therapy. We describe two cases of complete regression of esophageal varices and splenomegaly after interferon-alpha and ribavirin combination therapy in patients with HCV-related liver cirrhosis. Esophageal varices and splenomegaly regressed after 3 and 8 years of sustained virologic responses in cases 1 and 2, respectively. To our knowledge, this is the first study demonstrating that complications of liver cirrhosis, such as esophageal varices and splenomegaly, can regress after antiviral therapy in patients with HCV-related liver cirrhosis.

Endoplasmic reticulum stress induces 5-fluorouracil resistance in human colon cancer cells

Colon cancer can be treated with 5-fluorouracil (5-FU), but 5-FU resistance frequently occurs. We determined whether 5-FU resistance arises as a result of endoplasmic reticulum (ER) stress. 5-FU-resistant SNUC5 colon cancer cells (SNUC5/FUR cells) expressed higher levels of ER stress-related proteins than drug-sensitive SNUC5 cells. SNUC5/FUR cells also exhibited more intense ER staining and higher level of mitochondrial Ca(2+) overload. SNUC5/FUR cells transfected with siRNA against GRP78, ATF6, ERK, or AKT were more sensitive to 5-FU than siControl RNA-transfected cells. These results suggested that 5-FU resistance was associated with ER stress in colon cancer.

Induction of Endoplasmic Reticulum Stress via Reactive Oxygen Species Mediated by Luteolin in Melanoma Cells

BACKGROUND

This study aimed to investigate whether luteolin, a flavonoid, induces apoptosis in human melanoma cells via endoplasmic reticulum (ER) stress.

MATERIALS AND METHODS

To investigate the effects of luteolin in human melanoma cells, the anti-proliferation, apoptosis, ER stress induction and reactive oxygen species (ROS) generation were evaluated using MTT, Hoechst 33342, ER-tracker Blue White DPX and DCF-DA staining assays, respectively.

RESULTS

Luteolin inhibited cell proliferation and increased apoptotic body formation. Luteolin induced ER stress, as shown by ER staining and mitochondrial Ca(2+) overloading. Luteolin increased expression of the ER stress-related proteins; protein kinase RNA-like ER kinase, phospho eukaryotic translation initiation factor 2α, activating transcription factor (ATF) 6, CCAAT/enhancer-binding protein-homologous protein (CHOP), and cleaved caspase 12. Furthermore, luteolin increased the level of intracellular ROS, leading to ROS-mediated apoptosis and ER stress. However, N-acetyl cysteine, a ROS scavenger, decreased ROS levels, apoptosis, and ER stress induced by luteolin treatment. In addition, knockdown of CHOP and ATF6 by small-interfering RNA inhibited luteolin-induced cell death.

CONCLUSION

Luteolin induces apoptosis by ER stress via increasing ROS levels.

[Clinical Efficacy of Dynamic Contrast-enhanced Multidetector-row Computed Tomography in Patients with Obscure Gastrointestinal Bleeding]

BACKGROUND/AIMS

Obscure gastrointestinal bleeding (OGIB) accounts for 5% of all gastrointestinal (GI) bleeding cases. Dynamic contrast-enhanced multidetector-row CT (DCE-MDCT) is not generally recommended in OGIB patients due to its low sensitivity. However, it can be used to quickly and simply diagnose OGIB according to some guidelines. The aim of this study was to evaluate the clinical efficacy of DCE-MDCT in OGIB patients.

METHODS

We retrospectively analyzed the medical records of 362 patients who underwent DCE-MDCT between March 2009 and January 2014. A total of 45 patients diagnosed with OGIB were included in this study. Their baseline characteristics and treatment procedure were analyzed retrospectively. The positive rates of DCE-MDCT for the detection of bleeding and associated factors were assessed.

RESULTS

The mean age of the patients was 59 years, and males represented 51.1%. Melena was the most common symptom (44.4%). Positive rate of DCE-MDCT findings was 20.0% (9/45). Among these patients, intraluminal contrast extravasation was found in 5 patients (55.6%) and intraluminal hematoma or mass lesions were found in 2 patients each (22.2%). Thirty nine patients (86.7%) underwent conservative management, and 6 patients (13.3%) underwent specific treatment, such as endoscopic treatment, embolization, or surgery. Patients who showed positivity in DCE-MDCT more frequently received specific treatment compared with those who were negative (44.4% vs. 5.6%, p=0.010).

CONCLUSIONS

Although DCE-MDCT showed a low positive rate (20.0%), positive findings of DCE-MDCT could lead to specific treatment. Positive DCE-MDCT findings play a useful role in the management of patients with OGIB.

Antineutrophil cytoplasmic antibody-negative pauci-immune glomerulonephritis with massive intestinal bleeding

A 61-year-old woman was admitted to hospital because of generalized edema and proteinuria. Her renal function deteriorated rapidly. Serum immunoglobulin and complement levels were within normal ranges. An autoantibody examination showed negative for antinuclear antibody and antineutrophil cytoplasmic antibody. Histologic examination of a renal biopsy specimen revealed that all of the glomeruli had severe crescent formations with no immune deposits. The patient was treated with steroid pulse therapy with cyclophosphamide followed by oral prednisolone. Fifteen days later, she experienced massive recurrent hematochezia. Angiography revealed an active contrast extravasation in a branch of the distal ileal artery. We selectively embolized with a permanent embolic agent. On the 45(th) hospital day, the patient suddenly lost consciousness. Brain computed tomography showed intracerebral hemorrhage. We report a case of antineutrophil cytoplasmic antibody-negative pauci-immune glomerulonephritis with massive intestinal bleeding and cerebral hemorrhage.

Usefulness of C-reactive protein as a disease activity marker in Crohn's disease according to the location of disease

Background/Aims

C-reactive protein (CRP) is a serologic activity marker in Crohn’s disease (CD), but it may be less useful in evaluating CD activity in ileal CD patients. We aimed to investigate the usefulness of CRP as a disease activity marker in CD according to disease location.

Methods

Korean CD patients in a single hospital were evaluated. Factors associated with elevated CRP concentration at the time of diagnosis of CD and the association between the physician’s prediction regarding upcoming surgery and the sites of the lesions directly related to surgery were analyzed.

Results

Of 435 CD patients, 25.7%, 6.9%, and 67.4% had ileal, colonic, and ileocolonic CD, respectively. Multivariate analysis revealed that an elevated erythrocyte sedimentation rate, reduced serum albumin, CD activity index (CDAI) >220, and ileocolonic/colonic location were associated with an elevated CRP level and that the CRP level was significantly correlated with the CDAI in all CD patients (γ=0.466, p<0.01). However, the correlation coefficient was dependent on the location, with values of 0.395, 0.456, and 0.527 in patients with an ileal, ileocolonic, and colonic disease location, respectively. Surgery for ileal lesions was less predictable than surgery for ileocolonic or colonic lesions during follow-up.

Conclusions

CRP is less useful as a disease activity marker in patients with ileal CD than those with ileocolonic or colonic CD.

The ethyl acetate fraction of Sargassum muticum attenuates ultraviolet B radiation-induced apoptotic cell death via regulation of MAPK- and caspase-dependent signaling pathways in human HaCaT keratinocytes

CONTEXT

Our previous work demonstrated that an ethyl acetate extract derived from Sargassum muticum (Yendo) Fenshol (SME) protected human HaCaT keratinocytes against ultraviolet B (UVB)-induced oxidative stress by increasing antioxidant activity in the cells, thereby inhibiting apoptosis.

OBJECTIVE

The aim of the current study was to further elucidate the anti-apoptotic mechanism of SME against UVB-induced cell damage.

MATERIALS AND METHODS

The expression levels of several apoptotic-associated and mitogen-activated kinase (MAPK) signaling proteins were determined by western blot analysis of UVB-irradiated HaCaT cells with or without prior SME treatment. In addition, the loss of mitochondrial membrane potential (Δψm) was detected using flow cytometry or confocal microscopy and the mitochondria membrane-permeate dye, JC-1. Apoptosis was assessed by quantifying DNA fragmentation and apoptotic body formation. Furthermore, cell viability was evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay.

RESULTS

SME absorbed electromagnetic radiation in the UVB range (280-320 nm) of the UV/visible light spectrum. SME also increased Bcl-2 and Mcl-1 expression in UVB-irradiated cells and decreased the Bax expression. Moreover, SME inhibited the UVB-induced disruption of mitochondrial membrane potential and prevented UVB-mediated increases in activated caspase-9 and caspase-3 (an apoptotic initiator and executor, respectively) levels. Notably, treatment with a pan-caspase inhibitor enhanced the anti-apoptotic effects of SME in UVB-irradiated cells. Finally, SME reduced the UVB-mediated phosphorylation of p38 MAPK and JNK, and prevented the UVB-mediated dephosphorylation of Erk1/2 and Akt.

DISCUSSION AND CONCLUSION

The present results indicate that SME safeguards HaCaT keratinocytes from UVB-mediated apoptosis by inhibiting a caspase-dependent signaling pathway.

Acute extensive ischemic enteritis in a young man diagnosed with wireless capsule endoscopy: a case report

Ischemic enteritis is caused by either the interruption or significant reduction of arterial inflow to the small intestine. Risk factors are old age, diabetes mellitus and cardiovascular disease. It is very rare in young patients. We experienced a 21-year-old man with recurrent acute ischemic enteritis who was diagnosed with capsule endoscopy. He had previously taken medications for pulmonary hypertension and obstruction of both carotid arteries, and about 20 months earlier, he had been admitted due to hematochezia. Two sessions of angiography did not reveal the cause of hematochezia. At that time, capsule endoscopy showed mucosal edema and erythema in the terminal ileum, suggesting healed ischemic enteritis. The patient was admitted again due to hematochezia. Abdominal computed tomography showed focal celiac trunk stenosis and diffuse wall thickening of the small intestine, suggesting ischemic enteritis. Capsule endoscopy showed multiple active ulcers and severe hemorrhage with exudate, extending from the proximal jejunum to the terminal ileum. Using capsule endoscopy, the patient was diagnosed with acute extensive ischemic enteritis. Because endoscopic images of ischemic enteritis have rarely been reported, we report a case of a 21-year-old man who was diagnosed acute extensive ischemic enteritis with capsule endoscopy.

Diagnostic value of clinical T staging assessed by endoscopy and stomach protocol computed tomography in gastric cancer: the experience of a low-volume institute

Purpose

Clinical staging of gastric cancer appears to be important more and more for tailored therapy. This study aimed to verify the accuracy of clinical T staging in a low-volume institute.

Materials and Methods

We retrospectively reviewed prospectively collected data of gastric cancer patients who underwent resection. A total of 268 patients of gastric cancer were enrolled from March 2004 to June 2012. These demographics, tumor characteristics, and clinical stages were analyzed for identification of diagnostic value of clinical T staging.

Results

The predictive values for pT1 of endoscopy and computed tomography were 90.0% and 89.4%, respectively. In detail, the predictive values of endoscopy for pT1a, pT1b, and pT2 or more were 87%, 58.5%, and 90.6%, respectively. The predictive values of computed tomography for pT1a, pT1b, and pT2 or more were 68.8%, 73.9%, and 84.4%, respectively. The factors leading to underestimation of pT2 or more lesions by gastroscopy were the middle third location, the size greater than 2 cm, and younger age. Those for overestimation of pT1 lesion by computed tomography were male, age more than 70 years, elevated type, and size greater than 3 cm.

Conclusions

Diagnostic accuracy of early gastric cancer was 90%, which is comparable to those of high volume center. In patients with early gastric cancer, limited gastrectomy or minimal invasive surgery can be safely introduced at a low volume center also. However, the surgeon of low-volume institute should consider the accuracy of clinical staging before extending the indication of limited treatment.

[Clinical characteristics of pancreatic metastases]

BACKGROUND/AIMS

Histologically confirmed metastatic pancreatic cancers are infrequent. The aim of this study was to analyze clinical, therapeutic and prognostic features of pancreatic metastases.

METHODS

We retrospectively evaluated stage of primary malignancies, interval between diagnosis of primary tumors and detection of pancreatic metastases, treatment for metastases to the pancreas, survival rate, and prognostic factors in 31 patients with pancreatic metastases.

RESULTS

The mean age at the time of primary cancer diagnosis was 52.4 ± 13.2 years. Primary cancers were renal cell carcinoma (n=16), non-small cell lung cancer (n=6), small cell lung cancer (n=3), colorectal carcinoma (n=2), osteosarcoma (n=1), gastric carcinoma (n=1), malignant melanoma (n=1), and thymic carcinoma (n=1). Pancreatic metastases were synchronous in six cases and metachronous in twenty five cases, with median interval time of 40.8 months (range 3-186) between the diagnosis of primary tumor and detection of pancreatic metastases. The median survival after the detection of the metastases was 16 months. In multivariate analysis, non-renal cell carcinoma as primary malignancy and positive symptom related to pancreatic metastases were associated with poor prognosis (hazard ratio [HR], 8.33; 95% CI, 2.1-33; p=0.003, and HR, 4.02; 95% CI, 1.27-12.7; p=0.018).

CONCLUSIONS

Metastatic tumors to the pancreas have to be kept in mind when a patient with pancreatic mass has a history of other malignancy, even if treated several years before. In the absence of widely metastatic disease, aggressive diagnostic and therapeutic approach may offer the chance of long-term survival in selected patients.