Survey of nitrate and nitrite contents of vegetables grown in Korea

A scientific basis for the evaluation of the risk to public health arising from excessive dietary intake of nitrate in Korea is provided. The nitrate () and nitrite () contents of various vegetables (Chinese cabbage, radish, lettuce, spinach, soybean sprouts, onion, pumpkin, green onion, cucumber, potato, carrot, garlic, green pepper, cabbage and Allium tuberosum Roth known as Crown daisy) are reported. Six hundred samples of 15 vegetables cultivated during different seasons were analysed for nitrate and nitrite by ion chromatography and ultraviolet spectrophotometry, respectively. No significant variance in nitrate levels was found for most vegetables cultivated during the summer and winter harvests. The mean nitrates level was higher in A. tuberosum Roth (5150 mg kg(-1)) and spinach (4259 mg kg(-1)), intermediate in radish (1878 mg kg(-1)) and Chinese cabbage (1740 mg kg(-1)), and lower in onion (23 mg kg(-1)), soybean sprouts (56 mg kg(-1)) and green pepper (76 mg kg(-1)) compared with those in other vegetables. The average nitrite contents in various vegetables were about 0.6 mg kg(-1), and the values were not significantly different among most vegetables. It was observed that nitrate contents in vegetables varied depending on the type of vegetables and were similar to those in vegetables grown in other countries. From the results of our studies and other information from foreign sources, it can be concluded that it is not necessary to establish limits of nitrates contents of vegetables cultivated in Korea due to the co-presence of beneficial elements such as ascorbic acid and alpha-tocopherol which are known to inhibit the formation of nitrosamine.

The effect of rebamipide on the expression of proinflammatory mediators and apoptosis in human neutrophils by Helicobacter pylori water-soluble surface proteins

BACKGROUND

Helicobacter pylori infection elicits persistent neutrophil infiltration in gastric mucosa. The expression of cyclooxygenase (COX)-2 and inhibition of apoptosis in the neutrophils could contribute to the pathogenesis of H. pylori infection. Rebamipide, a mucosal protective and ulcer-healing drug, has been known to inhibit neutrophil activation.

AIM

To evaluate the effect of rebamipide on the neutrophils activated by H. pylori water-soluble proteins.

METHODS

After neutrophils were stimulated with H. pylori water extract (HPWE) or pre-treated with rebamipide, the expression of COX-2 mRNA and protein was assessed by quantitative RT-PCR and Western blotting, respectively. Prostaglandin (PG) E2 synthesis was determined by radioimmunoassay. Neutrophil apoptosis was evaluated by cytosolic oligonucleosome-bound DNA ELISA and caspase-3 activity was measured by the detection of p-nitroanilide after cleavage from labelled substrate.

RESULTS

Stimulation with HPWE up-regulated COX-2 expression and PGE2 secretion, and inhibited neutrophil apoptosis. Rebamipide suppressed PGE2 secretion from neutrophils dose-dependently. Rebamipide, however, did not affect neutrophil apoptosis and caspase-3 activity.

CONCLUSIONS

Rebamipide effectively suppressed PGE2 secretion from neutrophils activated by H. pylori water-soluble proteins. This is another possible mechanism of gastric mucosal protection by rebamipide.

Effect of Helicobacter pylori eradication on duodenal ulcer scar in patients with no clinical history of duodenal ulcer

BACKGROUND

Helicobacter pylori eradication has become the standard treatment for duodenal ulcer. However, there is no relevant evidence for antibacterial treatment of the white scar stage of duodenal ulcer (duodenal ulcer scar) in patients with no past history of duodenal ulcer.

AIM

To investigate whether H. pylori eradication could decrease duodenal ulcer recurrence in patients with duodenal ulcer scar and no past history of duodenal ulcer.

PATIENTS AND METHODS

We prospectively enrolled 66 patients with duodenal ulcer scar: 53 were H. pylori-positive and 13 were H. pylori-negative. H. pylori-positive patients were randomly assigned into two groups (two-to-one allocation): 36 patients were assigned to the treatment group and 17 to the follow-up group. Thirteen H. pylori-negative patients were followed up according to the study protocol. Follow-up endoscopy was performed to evaluate ulcer scar changes and H. pylori status 6 weeks after anti-H. pylori treatment and then every 6 months for up to 30 months.

RESULTS

Active duodenal ulcer recurrence was identified in seven of 23 H. pylori-positive/non-cured patients (30%). There was no duodenal ulcer recurrence in 43 H. pylori-negative/cured patients (0%), which was significantly different in terms of duodenal ulcer recurrence (P=0.001).

CONCLUSIONS

H. pylori eradication is effective at preventing active duodenal ulcer recurrence in patients with duodenal ulcer scar and no past history of duodenal ulcer.

Expression of cyclooxygenase-2 in human neutrophils activated by Helicobacter pylori water-soluble proteins: possible involvement of NF-kappaB and MAP kinase signaling pathway

Helicobacter pylori infection elicits persistent neutrophil infiltration in gastric mucosa. The expression of cyclooxygenase (COX) -2 by the neutrophils results in prostaglandin (PG) E2 synthesis, which may account for alterations in tissue homeostasis. In this study, we found that COX-2 mRNA was up-regulated in the neutrophils when stimulated with both H. pylori water extract (HPWE) and live H. pylori in a transwell model and determined by quantitative RT-PCR. PGE2 synthesis was also enhanced in the neutrophils activated by both the HPWE and live H. pylori. A specific COX-2 inhibitor (NS-398) blocked PGE2 synthesis, and an anti-ulcer agent (rebamipide) suppressed it dose dependently. An NF-kappaB inhibitor (pyrrolidine dithiocarbamate), a MAP kinase (MEK) inhibitor (PD98059), and a p38 MAP kinase inhibitor (SB203580) significantly suppressed the COX-2 gene transcription and PGE2 synthesis in the neutrophils. In conclusion, H. pylori water-soluble proteins may enhance the COX-2 expression, and this action could be mediated through the NF-kappaB and MAP kinase signaling pathways. The increased section of PGE2 by the neutrophils may play a proinflammatory role in the gastric mucosal response to H. pylori.

Expression of cyclooxygenase-2 in human neutrophils activated by Helicobacter pylori water-soluble proteins: possible involvement of NF-kappaB and MAP kinase signaling pathway

Helicobacter pylori infection elicits persistent neutrophil infiltration in gastric mucosa. The expression of cyclooxygenase (COX) -2 by the neutrophils results in prostaglandin (PG) E2 synthesis, which may account for alterations in tissue homeostasis. In this study, we found that COX-2 mRNA was up-regulated in the neutrophils when stimulated with both H. pylori water extract (HPWE) and live H. pylori in a transwell model and determined by quantitative RT-PCR. PGE2 synthesis was also enhanced in the neutrophils activated by both the HPWE and live H. pylori. A specific COX-2 inhibitor (NS-398) blocked PGE2 synthesis, and an anti-ulcer agent (rebamipide) suppressed it dose dependently. An NF-kappaB inhibitor (pyrrolidine dithiocarbamate), a MAP kinase (MEK) inhibitor (PD98059), and a p38 MAP kinase inhibitor (SB203580) significantly suppressed the COX-2 gene transcription and PGE2 synthesis in the neutrophils. In conclusion, H. pylori water-soluble proteins may enhance the COX-2 expression, and this action could be mediated through the NF-kappaB and MAP kinase signaling pathways. The increased section of PGE2 by the neutrophils may play a proinflammatory role in the gastric mucosal response to H. pylori.

Caspase-3 activity and expression of Bcl-2 family in human neutrophils by Helicobacter pylori water-soluble proteins

BACKGROUND

Persistent infiltration of neutrophils is an almost invariable feature of Helicobacter pylori-infected gastric mucosa. A prolongation of neutrophil life-span could contribute to the pathogenesis of H. pylori infection. Recently, we have demonstrated that H. pylori water extracts (HPWE) inhibited neutrophil apoptosis. To elucidate the regulation of intracellular apoptotic signals by HPWE, we examined the activity of caspase-8, -3 and expression of Bcl-2 family in neutrophils.

MATERIALS AND METHODS

Human neutrophils were obtained from the peripheral blood of healthy volunteers by density gradient separation. HPWE was prepared from a supernatant of the H. pylori suspension in distilled water. After neutrophils were incubated with HPWE, expression of Bcl-2 family [antiapoptotic (Bcl-2, Bcl-XL and Mcl-1) and proapoptotic (Bax, Bak and Bcl-XS)] was determined by RT-PCR and Western blotting, respectively. Western blot for Bcl-2 family also performed in neutrophilic differentiated HL-60 cells by all-trans-retinoic acid. The activity of caspase-8, -3 was measured by the detection of p-nitroanilide after cleavage from labeled substrate.

RESULTS

HPWE suppressed the activation of caspase-8 and -3, and upregulated the expression of Bcl-XL mRNA and proteins in neutrophils. The expression of Bax and Bak was upregulated and Bcl-2, Bcl-XL and Mcl-1 downregulated in HL-60 cells during neutrophilic differentiation.

CONCLUSION

Bcl-XL may have an important role in the neutrophilic development and inhibition of neutrophil apoptosis by H. pylori.

Contribution of ion pair complexation with bile salts to biliary excretion of organic cations in rats

The objective of this study was to examine whether ion pair complexation with endogenous bile salts in hepatocytes contributes to the preferential biliary excretion of organic cations (OCs). Tributylmethylammonium (TBuMA; mol wt 200) and triethylmethylammonium (TEMA; mol wt 116) were selected as model OCs that exhibit significant and negligible biliary excretion, respectively, in rats. The apparent lipophilicity of TBuMA, but not that of TEMA, was increased by the presence of either rat bile or specific bile salts, suggesting the formation of lipophilic ion pair complexes for TBuMA with bile salts in the liver. The uptake of TBuMA into canalicular liver plasma membrane (cLPM) vesicles, but not that of TEMA, was increased in the presence of bile salts, with a significant increase for both ATP-dependent transport and passive diffusion. The uptake of TBuMA in the presence of the bile salts was inhibited by representative P-glycoprotein (P-gp) substrates and vice versa, suggesting the involvement of P-gp in the canalicular excretion of TBuMA-bile salt complexes in vivo. Increased affinity toward P-gp is suggested as the mechanism responsible for the increased ATP-dependent transport for the ion pair complexes. We propose that ion pair formation with bile slats in hepatocytes may be responsible for the preferential biliary excretion of high-molecular-weight OCs including TBuMA.

Inhibition of apoptosis in human neutrophils by Helicobacter pylori water-soluble surface proteins

BACKGROUND

Helicobacter pylori infection in humans causes persistent neutrophil infiltration into the gastric mucosa. It is believed that a prolongation of neutrophil life-span could contribute to the pathogenesis of H. pylori infection. We therefore examined whether the water-soluble surface proteins of H. pylori can influence the apoptosis of neutrophils.

METHODS

After neutrophils were incubated with H. pylori water extract (HPWE), neutrophil apoptosis was evaluated by TUNEL assay, Hoechst 33342 staining, electron microscopy and ELISA for cytosolic oligonucleosome-bound DNA for up to 48 h. To investigate the regulatory mechanisms of neutrophil apoptosis associated with HPWE, mRNA expression and protein production of Fas, Fas ligand (FasL) and tumor necrosis factor receptor 1 (TNF-R1) were analyzed by RT-PCR, ribonuclease protection assay, Northern blot and Western blotting. Cell surface expression of these death factors was also measured by flow cytometry.

RESULTS

HPWE inhibited neutrophil apoptosis and cytotoxicity for up to 48 h. The mRNA and protein expression of FasL and the cell surface expression of Fas, FasL and TNF-R1 in HPWE-treated neutrophils were suppressed compared with the controls.

CONCLUSION

The water-soluble surface proteins of H. pylori could suppress neutrophil apoptosis. This may be caused by the suppression of FasL expression in neutrophils and Fas, FasL and TNF-R1 expression on the surface of neutrophils.

Hepatopulmonary syndrome in poorly compensated postnecrotic liver cirrhosis by hepatitis B virus in Korea

BACKGROUND

Hepatopulmonary syndrome (HPS) refers to the association of hypoxemia, intrapulmonary shunting and chronic liver disease. But there is no clear data about the prevalence of HPS in postnecrotic liver cirrhosis by hepatitis B virus (HBV), the most common cause of liver disease in Korea. The aim of this study was to investigate the prevalence of HPS in poorly compensated postnecrotic liver cirrhosis by HBV, and the correlation of the hepatopulmonary syndrome with clinical aspects of postnecrotic liver cirrhosis by HBV.

METHODS

Thirty-five patients underwent pulmonary function test, arterial blood gas analysis and contrast-enhanced echocardiography. All patients were diagnosed as HBV-induced Child class C liver cirrhosis and had no evidence of intrinsic cardiopulmonary disease.

RESULTS

Intrapulmonary shunt was detected in 6/35 (17.1%) by contrast-enhanced echocardiography. Two of six patients with intrahepatic shunts had significant hypoxemia (PaO2 < 70 mmHg) and four showed increased alveolar-arterial oxygen gradient over 20 mmHg. Only cyanosis could reliably distinguish between shunt positive and negative patients.

CONCLUSIONS

The prevalence of intrapulmonary shunt in poorly compensated postnecrotic liver cirrhosis by HBV was 17.1% and the frequency of hepatopulmonary syndrome was relatively low (5.7%). 'Subclinical' hepatopulmonary syndrome (echocardiographically positive intrapulmonary shunt but without profound hypoxemia) exists in 11.4% of cases with poorly compensated postnecrotic liver cirrhosis by HBV. Cyanosis is the only reliable clinical indicator of HPS of HBV-induced poorly compensated liver cirrhosis. Further studies are required to determine if the prevalence and clinical manifestations of HPS varies with etiology or with geographical and racial differences.

Upregulated cyclooxygenase-2 inhibits apoptosis of human gastric epithelial cells infected with Helicobacter pylori

Helicobacter pylori induces apoptosis and alters the proliferation of gastric mucosal epithelial cells. Cyclooxygenase-2 (COX-2), the inducible form of prostaglandin (PG) synthesis, is known to cause alteration in epithelial cell growth. The goal of this study was to determine whether COX-2 gene expression by H. pylori infection could influence gastric epithelial cell apoptosis. Expression of COX-2 mRNA and proteins was up-regulated in Hs746T gastric epithelial cell lines infected with H. pylori, when assessed by quantitative RT-PCR and western blot. Inhibition of COX-2 expression using NS-398, a specific COX-2 inhibitor, showed a significant increase of gastric epithelial cell apoptosis and caspase-3 activation in Hs746T cells infected with H. pylori. Moreover, the effect of NS-398 on H. pylori-induced apoptosis was reversed by the addition of PGE2. These results suggest that up-regulated COX-2 expression by H. pylori infection can inhibit apoptosis of gastric epithelial cells.

Helicobacter pylori in dental plaque and saliva

BACKGROUND

About half of the world population is infected with H. pylori, but the transmission and the source of this infection are still unclear. Recently, dental plaque (DP) and saliva have been implicated as possible sources of H. pylori infection. This study was done to investigate the detection rates of H. pylori in the DP and saliva by use of PCR depending on H. pylori infection state of gastric mucosa.

METHODS

In 46 subjects, gastric H. pylori colonization was evaluated with CLO test, microscopy of Gram stained mucosal smear, culture and histology after modified Giemsa staining in the antrum and body, respectively. A patient was regarded as H. pylori positive if one or more of the four aforementioned test methods demonstrated H. pylori colonization of the gastric mucosa. For detection of H. pylori in the DP and saliva, PCR assay was done with ET4-U and ET4-L primers. To estimate the sensitivity and specificity of this PCR, H. pylori positivity was evaluated in the antrum and body, separately.

RESULTS

The sensitivity of mucosal PCR was 50.0% (27/54) and the specificity 86.8% (33/38). When a subject was regarded as H. pyloi positive, if either antrum or body mucosal H. pylori was is positive, the positive rate of mucosal PCR was 62.1% (18 subjects) in the 29 H. pylori-positive and 17.6% (3 subjects) in the 17 H. pylori-negative subjects. DP PCR was positive in 2 of 29 H. pylori-positive subjects (6.9%) and none in the 17 H. pylori-negative (0%). Saliva PCR was positive in 4 of 14 H. pylori-positive subjects (28.6%) and none of 6 H. pylori-negative (0%).

CONCLUSION

The detection rates of H. pylori in DP and saliva by PCR were rather low, 6.9% and 28.6%, respectively, and these rates might have been underestimated by low sensitivity of the PCR method used in this study. However, the results that H. pylori was found in the DP and saliva suggest that the oral cavity can perform a role as a reservoir of H. pylori in Korea.

Virulence factors of Helicobacter pylori in Korean isolates do not influence proinflammatory cytokine gene expression and apoptosis in human gastric epithelial cells, nor do these factors influence the clinical outcome

The cytotoxin-associated gene (cagA) and vacuolating cytotoxin (Vac) production have been reported to be major virulence factors of Helicobacter pylori. However, there have been some disputes regarding the correlation between these virulence factors and clinical outcomes. We evaluated whether the cagA-positive genotype and Vac production might be correlated with various gastroduodenal diseases in Korea and whether this correlation could be due to differences in proinflammatory cytokine gene expression and apoptosis of gastric epithelial cells in vitro. The presence of the cagA gene was examined by the polymerase chain reaction (PCR), and Vac production was detected using the bacterial culture supernatant and HeLa cells after H. pylori was isolated from Korean patients. Gastric epithelial cells were infected with cagA+Vac+, cagA+Vac-, or cagA-Vac- strains, after which cytokine gene expression was evaluated, using quantitative reverse transcription (RT)-PCR. Apoptosis and caspase-3 activation were measured in H. pylori-infected gastric epithelial cells. There was no significant correlation between the presence of these virulence factors in H. pylori isolates and peptic ulcer or gastric cancer. Upregulation of cytokine gene expression, including that of interleukin (IL)-1alpha, IL-8, granulocyte macrophage colony-stimulating factor (GM-CSF), and monocyte chemotactic protein (MCP)-1, as well as apoptosis and caspase-3 activation, were similar in infections with cagA-positive and cagA-negative strains, but were not correlated with the production of Vac. These results suggest that the lack of correlation between virulence factors of isolated H. pylori strains and serious gastroduodenal disease entities in Korea may be due to the similar capacity for proinflammatory cytokine gene expression and apoptosis caused by infection with each of the H. pylori strains.

Hypoalbuminemia as a risk factor for progressive left-ventricular hypertrophy in hemodialysis patients

BACKGROUND

This study was performed to evaluate the changes in left-ventricular (LV) mass in the patients starting maintenance hemodialysis and the risk factors for the progression of LVH.

METHODS

From June 1994 to February 1997, baseline echocardiography was obtained within six months after the initiation of hemodialysis in 111 patients with end-stage renal disease. Of the patients who had LVH on baseline echocardiography, 32 patients underwent follow-up echocardiography after 15 months (range: 9-24 months). LVH was defined as a left-ventricular mass index (LVMI) greater than 131 g/m(2) in males and 100 g/m(2) in females. Progressive LVH was defined as a follow-up LVMI greater than 105% of the baseline value. Hemoglobin, blood urea nitrogen, creatinine, cholesterol, albumin, prealbumin, parathyroid hormone, Kt/V, nPCR, fibrinogen, homocysteine and ACE gene polymorphism were also measured.

RESULTS

LVH was detected in 91 of 111 (82%) ESRD patients starting maintenance hemodialysis. Of the 32 patients in whom follow-up echocardiography was performed, progressive LVH occurred in 19 patients (M:F = 12:7). Progressive LVH was associated with lower diastolic blood pressure (81 +/- 11 vs. 90 +/- 12 mm Hg, p = 0.036) and lower serum albumin (3.5 +/- 0.4 vs. 3.9 +/- 0.4 g/dl, p = 0. 009). Serum albumin was negatively (r = -0.420, p = 0.017) correlated to Delta LVMI (follow-up LVMI minus baseline LVMI). Hypoalbuminemia was an independent risk factor for progressive LVH in multiple logistic regression analysis (R.R. = 1.29, p = 0.046). The association of progressive LVH with age, gender, diabetes mellitus, smoking history or other laboratory parameters was not significant.

CONCLUSION

LVH was highly prevalent in the patients starting maintenance hemodialysis for ESRD. In the follow-up echocardiography, LVH progressed in a substantial portion of the patients, and hypoalbuminemia was a risk factor for progressive LVH.

Incidence and prevalence of ulcerative colitis in the Songpa-Kangdong District, Seoul, Korea, 1986-1997

BACKGROUND AND AIMS

Ulcerative colitis (UC) is regarded as a rare disease in developing countries, but accurate data are generally lacking. We performed the present study to evaluate the incidence and prevalence of UC in Korea.

METHODS

A retrospective study was performed from 1986 to 1997 in the Songpa-Kangdong district of Seoul, Korea. To recruit UC patients as completely as possible, multiple information sources including all medical facilities in the study area and three referral centres located nearby, but outside the study area were used. The incidence and prevalence rates were adjusted using the 1997 Korean population statistics.

RESULTS

During the study period, a total of 94 incident cases were identified, for an adjusted mean annual incidence rate of 0.68 per 100,000 inhabitants. On 31 December 1997, 91 patients with UC lived in the study area, giving an adjusted prevalence rate of 7.57 per 100,000 inhabitants. By using the Poisson regression analysis, the annual incidence rate increased significantly from 0.20 per 100,000 inhabitants in 1986-1988 to 1.23 per 100,000 inhabitants in 1995-1997 (P < 0.005). Patient age at diagnosis, the interval from onset of symptoms to diagnosis, and the disease extent at diagnosis were fairly constant throughout the study period.

CONCLUSIONS

The incidence and prevalence of UC in our study area are still low compared with those of Western countries, but the incidence rate is steadily increasing.

Long-term effects of Helicobacter pylori eradication on intestinal metaplasia in patients with duodenal and benign gastric ulcers

This study was conducted to investigate whether or not the eradication of H. pylori could lead to the regression of intestinal metaplasia (IM) in patients with either duodenal ulcer (DU) or benign gastric ulcer (BGU). The initial antral IM grade was 0.21 in the 72 patients of the H. pylori-eradicated DU group, this decreased to 0.17, 0.14, 0.13, and 0.09 after periods of four weeks, one year, two years, and four years, respectively, but without statistical significance. In the corpus of the DU group, where IM grade was low (0.02), there was no detectable change in IM. The initial antral IM grade of 0.69 in the 41 patients of the H. pylori-eradicated BGU group decreased substantially to 0.61, 0.44, and 0.39 after periods of four weeks and one and two years, respectively, but again without statistical significance. The initial corporal IM grade of the BGU group of 0.27 decreased to 0.20, 0.15, and 0.06 after periods of four weeks and one and two years, again without statistical significance. In contrast, the IM grades of the noneradicated DU group (N = 20) and the BGU group (N = 16) showed nearly no change in the antrum and corpus. Gastritis grades of antrum and corpus in the H. pylori-eradicated DU or BGU group significantly decreased with respect to time (P = 0.0001), but there were no significant changes in the corresponding noneradicated groups. Although there was no statistical significance, IM decreased in the antrum and corpus of the stomach with BGU and in antrum of those with DU over a two to four-year period after H. pylori eradication, suggesting the possible reversibility of IM.

Prediction of the clinical course of Behçet's colitis according to macroscopic classification by colonoscopy

BACKGROUND AND STUDY AIMS

The lesions in Behçet's colitis show aphthoid or punched-out ulceration, but the macroscopic types of lesion found have not been defined. To predict the clinical outcome in patients with Behçet's colitis according to the colonoscopic findings, we classified the characteristic colonic ulcers, evaluated the efficacy of medical treatment on colonoscopic lesions, and calculated the operation rates and recurrence rates relative to the macroscopic types.

PATIENTS AND METHODS

The medical records and colonoscopic photographs of 50 patients with Behçet's colitis were reviewed. The colonic lesions were examined by colonoscopy in patients with Behçet's disease and gastrointestinal symptoms. The colonoscopic findings were categorized into three types of ulceration: volcano-like, geographic, and aphthous. The efficacy of medical treatment was assessed by follow-up colonoscopy or double-contrast barium enema four to eight weeks after treatment, and recurrence of the lesions was evaluated during the follow-up periods. Cumulative surgery rates were obtained using the Kaplan-Meier method.

RESULTS

The macroscopic classification of colonic ulcers identified 25 of 50 patients (50%) with volcano-type lesions, 11 (22%) with the geographic type, and 14 (28%) with the aphthous type. The rates of complete remission after medical treatment and surgery, respectively, were six of 25 (24%) and 13 of 25 (52%) with volcano-type ulcerations; eight of 11 (73%) and one of 11 (9%) with the geographic type; and nine of 14 (64%) and two of 14 (14%) with the aphthous type. The endoscopic and clinical recurrence rates were nine of 19 (47%) in volcano-type ulcerations, one of nine (11%) in the geographic type, and one of 11 (9%) in the aphthous type.

CONCLUSION

Volcano-type ulcerations in Behçet's colitis showed a less favorable response to medical treatment, a more frequent requirement for surgery, and more frequent recurrences than the geographic and aphthous types of ulcerations.

Long-term clinical course and prognostic factors in intestinal Behçet's disease

PURPOSE

The present study was aimed at evaluating the long-term course of intestinal Behçet's disease and determining predictive factors of prognosis.

METHODS

This report is a retrospective study based on the records of 43 patients with intestinal Behçet's disease. The mean follow-up duration was 73 +/- 60 months. We evaluated the efficacy of medical treatment for the intestinal lesion at initial eight weeks. The cumulative probabilities were calculated by using Kaplan-Meier method, and the results were compared by using the log-rank test.

RESULTS

Sixteen patients (38 percent) achieved a complete remission of intestinal lesions eight weeks after medical treatment had begun. The patients who achieved a complete remission had a lower probability of receiving an operation than those who had not (13 percent at 2 and 5 years vs. 36 and 43 percent, respectively; P = 0.028). The recurrence probability of intestinal lesions was 25 percent at two years and 49 percent at five years after complete remission with medical treatment. Patients who had a history of intestinal perforation or fistula had a higher probability of recurrence after operation than those without such history (59 vs. 33 percent at 2 years; 88 vs. 57 percent at 5 years; P = 0.020). Patients who had taken azathioprine had a lower probability of receiving reoperation than those who did not (7 vs. 25 percent at 2 years; 25 vs. 47 percent at 5 years; P = 0.035). The length of ileal resection and whether hemicolectomy was performed had no significant effect on the recurrence or reoperation rate.

CONCLUSIONS

Intestinal Behçet's disease frequently requires a surgical treatment and has a high recurrence rate. The patients who achieved a complete remission with medical treatment, who had no history of intestinal perforation, and who received azathioprine after operation showed better clinical courses. Resection of a short segment of bowel would be a more appropriate surgical procedure.

Substance P induction of murine keratinocyte PAM 212 interleukin 1 production is mediated by the neurokinin 2 receptor (NK-2R)

The neurological system plays an important role in modulating some inflammatory skin diseases. Neuro-cutaneous interactions may be mediated by the release of neuropeptides such as substance P (SP) which activate immunocompetent cells in the skin by binding to high affinity neurokinin receptors (NKR). Since epidermal keratinocytes produce a variety of cytokines and are intimately associated with cutaneous sensory fibers, we tested the ability of these cells to participate in the cutaneous neuroimmune system by the secretion of potent cytokines such as interleukin 1 (IL-1) in response to released SP. RT-PCR studies demonstrated that cultured PAM 212 murine keratinocytes expressed mRNA for NK-2R but not NK-1R. Correspondingly, the addition of SP to these cells resulted in a rapid increase in intracellular Ca2+ levels that could be specifically blocked by an NK-2R antagonist. NK-2R was also shown in normal mouse epidermis by immunohistochemistry. SP augmented the expression of PAM 212 keratinocyte IL-1alpha mRNA in a dose and time dependent manner and this induction was inhibited by an NK-2R antagonist. Secretion of bioactive IL-1alpha by the PAM 212 keratinocytes was likewise stimulated by SP in a dose dependent manner. These data support the hypothesis that SP released from cutaneous sensory nerves contributes to neuroimmune inflammatory responses in the skin by modulating the expression and release of cytokines from epidermal keratinocytes.

Helicobacter pylori water-soluble surface proteins activate human neutrophils and up-regulate expression of CXC chemokines

To elucidate the mechanisms of the persistent neutrophil recruitment in H. pylori-infected gastric mucosa, we evaluated the activation of human neutrophils and CXC chemokine expression in neutrophils by H. pylori water-soluble surface proteins. H. pylori water extract (HPWE) was prepared from a supernatant of the H. pylori suspension in distilled water. After neutrophils were stimulated with HPWE, the mobilization of intracellular free calcium, the expression of lymphocyte function-associated antigen-1beta, and the secretion of myeloperoxidase (MPO) were enhanced in the neutrophils. In H. pylori-infected gastric mucosa, transendothelial and transepithelial migration of neutrophils were observed by electron microscopy and mucosal MPO levels were elevated. Up-regulation of the expression of interleukin-8 (IL-8) and growth-related oncogenes (GROs; GROalpha, GRObeta and GROgamma) mRNA and protein in neutrophils by HPWE was demonstrated by quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. In conclusion, H. pylori-induced neutrophil recruitment may be mediated by CXC chemokines which are expressed by neutrophils activated by H. pylori water-soluble surface proteins.

Apoptosis of human gastric epithelial cells via caspase-3 activation in response to Helicobacter pylori infection: possible involvement of neutrophils through tumor necrosis factor alpha and soluble Fas ligands

BACKGROUND

Infection with Helicobacter pylori activates a proinflammatory gene program in human gastric epithelial cells and neutrophils and is associated with significant epithelial cell damage, including an increased level of apoptosis. We evaluated whether immune mediators produced by neutrophils could modulate gastric epithelial cell apoptosis in response to H. pylori infection.

METHODS

After gastric epithelial cells were infected with H. pylori in the presence of immune mediators, including tumor necrosis factor alpha (TNF-alpha) and Fas ligand (FasL), apoptosis and caspase-3 activity were assessed. The neutrophils were obtained from healthy volunteers, and Western blot for FasL and quantitative reverse transcription polymerase chain reaction for TNF-alpha transcripts were performed. Fas expression in gastric epithelial cells was explored by flow cytometric analysis.

RESULTS

Activation of caspase-3 was first apparent 12 h after bacterial infection, and the phenotypic expression of apoptosis was first apparent 18 h after bacterial infection. The extent of apoptosis was similar in cases of cagA+ cytotoxin+, cagA+ cytotoxin-, cagA- cytotoxin- H. pylori-infected gastric epithelial cells. Approximately 20% of the Hs746T cells expressed Fas within 24 h of H. pylori infection. The soluble FasL was upregulated in neutrophils after treatment with H. pylori-soluble proteins for 24 and 48 h. The addition of TNF-alpha and the soluble form of FasL, produced by neutrophils, significantly increased H. pylori-infected cell apoptosis and caspase-3 activation. However, the combination of these two immune mediators showed only an additive increase.

CONCLUSION

These results suggest that H. pylori-induced gastric epithelial cell apoptosis and caspase-3 activation can be modulated by the immune response of neutrophils.

A precipitation reaction found in patients with hepatitis C as a marker for the purification of virus-like particles

Even after the molecular cloning of the hepatitis C virus (HCV), an HCV-specific precipitation reaction has not yet been identified. We attempted to develop a precipitation system exclusively for anti-HCV-positive sera as a first step in finding an HCV-specific antigen and HCV-associated particles. In some patients being in a final stage of different liver diseases, we found sera (179/132,761; designated 'a-CK') which specifically precipitated with anti-HCV- and HCV-RNA-positive sera (designated 'CK'). When CK-positive sera were searched for in patients with various liver diseases using standard a-CK-positive plasma, CK was detected in 420 (57.9%) of 726 anti-HCV-positive sera and in none of the 1,630 anti-HCV-negative ones. The nature of CK and a-CK has not been fully clarified yet; CK demonstrated inter-betagamma mobility, whereas a-CK showed beta-globulin mobility; CK was not detected in cryoprecipitate, but HCV RNA was present in precipitates of CK-positive plasma incubated with one that was a-CK positive. Transmission electron microscopy revealed two size ranges of particles in the precipitate of CK- and a-CK-positive plasmas, 23-38 nm and 48-65 nm. We have found a novel precipitation system which is exclusive to anti-HCV-positive sera and which specifically precipitates an HCV-RNA-containing serum fraction and particles. This system can be useful for the purification and characterization of the circulating particles. Furthermore, it may be a new approach to the nature of HCV-RNA-carrying material.

Effect of DA-6034, a derivative of flavonoid, on experimental animal models of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a multifactorial disorder with unknown etiology and pathogenesis. DA-6034, 7-carboxymethyloxy-3', 4', 5-trimethoxy flavone, is a synthetic flavonoid known to possess anti-inflammatory activity. This study was performed to evaluate the oral therapeutic effect of DA-6034 in three experimental animal models of IBD: two chemical-induced IBD models of rats and the human leukocyte antigen (HLA)-B27 transgenic rat model known to develop spontaneous colitis without the use of exogenous agents. Acute chemical colitis was induced by intracolonic instillation of 1.2 ml of 4% acetic acid solution. Prednisolone (1 mg/kg), sulfasalazine (100 mg/kg) and DA-6034 (0.3 to approximately 3 mg/kg) were orally administered twice daily for 6 days in these rats. In addition, chronic chemical colitis was induced by intracolonic administration of trinitrobenzene sulfonic acid (TNBS) 30 mg in 50% ethanol and agents were orally administered for 6 or 20 days. In chemical-induced IBD models, all of these agents reduced the severity of colitis and specially, DA-6034 (3 mg/kg) showed more potent effect than other drugs in macroscopic lesion score. In HLA-B27 transgenic rats, DA-6034 (3 mg/kg) and prednisolone (0.5 mg/kg) were treated orally twice daily for 6 weeks. The HLA-B27 transgenic rats showed only mild colitis, compared with the chemical-induced colitis models. DA-6034 ameliorated the loose stool and decreased microscopic damage, which is the important indicator of this model. In conclusion, oral therapy of DA-6034 attenuated the macroscopic and histologic damages of the colon in all three experimental models of IBD, which suggest that DA-6034 could be a promising drug in the treatment of IBD.

Establishment of BALB/c mice model infected with Helicobacter pylori

OBJECTIVES

Considering the geographic differences in the prevalence of virulence factors such as CagA or VacA of H. pylori isolated from Korean adults compared with those from western countries, the establishment of a mouse model infected with H. pylori isolated from Korean adults is needed to investigate the pathogenesis and to develop vaccines against H. pylori infection in Korea. The aim of this study was to establish the BALB/c mouse model infected with H. pylori isolated from Korean.

METHODS

Six-week-old BALB/c mice were inoculated intragastrically with 10(9) CFU of H. pylori. Loss of glandular architecture, erosions and infiltration of inflammatory cells within the lamina propria compared with normal gastric mucosa were scrutinized. Evidence for H. pylori infection was assessed by rapid urease test of gastric mucosa and by microscopic examination using the H & E stain and Warthin-Starry silver stain.

RESULTS

Rapid urease test was positive in 55% of all inoculated mice. Definite histologic changes and the evidence of H. pylori colonization were observed in the H. pylori infected group. Significant infiltration of inflammatory cells was observed 6 weeks after the last inoculation and the level of serum IgG against H. pylori was increased from 2 weeks after the last inoculation.

CONCLUSIONS

The H. pylori isolated freshly from Korean adults could colonize the stomach of BALB/c mice and induce pathologic alterations that mimics human gastric diseases. This model would facilitate the investigations for the pathogenetic mechanisms of H. pylori infection.