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Alterations in immunological defense in the gut may lead to the bacterial infection that is frequently associated with cirrhosis of the liver. The aim of this study was to investigate the changes in distribution and function of intestinal intraepithelial lymphocytes (IELs) in relation to intestinal barrier dysfunction in experimental cirrhosis. Cirrhosis was induced in mice by treatment with carbon tetrachloride (CCl4) intraperitoneally with 5% alcohol in drinking water for 12 weeks. Bacterial translocation was assessed in mesenteric lymph nodes (MLNs) by the transport of fluorescence-labeled latex beads and by bacteriological cultures. The lymphocyte subpopulation was compared in three groups (cirrhosis, alcohol alone and controls). IFN-gamma production from isolated IELs was determined by ELISA after stimulation with anti-CD3 or IL-12/IL-18. The total number of IELs significantly increased in the cirrhosis and alcohol groups. There was a preferential increase in TCRgammadelta+CD8+ population in the alcohol group, but no change in cirrhosis. Bacterial translocation was negative in the control group, and a small number was noted in the alcohol group, whereas it was significantly noted in the cirrhosis group. Although the number of IEL was significantly increased in the cirrhosis group, their proliferative response was decreased, and IFN-gamma production from each IEL was markedly diminished in either stimulation by anti-CD3 or IL-12/IL-18. These changes were more remarkable in the cirrhosis group than in the alcohol group. In conclusion, bacterial translocation due to intestinal barrier dysfunction in cirrhosis may be closely correlated with the alteration of the immune function in IELs.

Background and Aim: The pathogenesis of ulcerative colitis (UC) is unclear, but abnormal infiltration of T lymphocytes in the colonic mucosa has been implicated in the mucosal tissue damage. The abnormal cytokine production because of a T helper (h)1/Th2 imbalance may play an important role in continuing inflammation in the colonic mucosa. In the present study, the expression of chemokine receptor 5 (CCR5) as a Th1 marker and a chemoattractant receptor-homologs molecule expressed on Th2 cells (CRTH2) were investigated in order to analyze impaired Th1/Th2 responses in the colonic mucosa of UC patients. Methods: Tissue samples were obtained by colonic biopsies from patients with UC or colonic polyps, with informed consent. Immunohistochemical analysis was performed on periodate, lysine-paraformaldehyde-fixed serial cryostat sections using the labeled streptavidin biotin method. Monoclonal antibodies against CD4, CCR5 or CRTH2 were used as primary antibodies. The number of cells expressing CD4, CCR5 or CRTH2 per unit area was calculated by using an image analyzer. Results: In the patients with UC, the numbers of CD4- and CCR5-positive cells were significantly increased in inflamed mucosa, and appeared to be correlated with the disease activity. The infiltration of CRTH2-positive cells was predominantly observed in the mildly inflamed or the margin of inflamed mucosa of UC patients. Conclusion: There is a possibility that Th1 responses significantly occur in colonic mucosa with severe inflammation, while Th2 responses mainly occur with mild inflammation in UC patients. The Th1/Th2 imbalance in colonic mucosa may be related to the disease progression of UC.

Background: Infrared light can penetrate tissue more deeply than visible light. Therefore, an infrared video endoscope may be useful for assessment of gastric submucosal vessels. However, the resolution of currently available infrared video endoscope systems has been unsatisfactory. A new infrared video endoscope system was developed and its clinical utility assessed for diagnosis of early stage gastric cancer. Methods: Twenty-five patients with early stage gastric cancer and 8 with gastric adenoma underwent endoscopy with the infrared video endoscope system after intravenous injection of indocyanine green. Result: Indocyanine green pooling did not appear in adenomas and some intramucosal gastric cancers, whereas it was noted in all submucosally invasive gastric cancers. Tumors not exhibiting indocyanine green pooling were intramucosal, well-differentiated adenocarcinomas of low height (flat-type cancers). Conclusion: These results suggest that our new infrared video endoscope provides valuable information about the submucosal aspect of early stage gastric cancer. Infrared video endoscopy may become a powerful technique for determining whether to perform endoscopic mucosal resection. (Gastrointest Endosc 2003;57:336-42.)

Endoscopic mucosal resection with a cap-fitted panendoscope is a useful, effective, and safe technique. The effectiveness and safety of a newly designed larger but softer cap was compared in this study with the conventional hard cap. The soft cap has a significantly larger diameter (18 mm) compared with that of the hard cap (16.5 mm).Eighty-three patients who underwent mucosal resection of gastric lesions were included in analysis. The diameter, resection specimen depth, and the rate of en bloc resection were compared. The operability of the endoscope with the cap attached, patient tolerance, and safety of the procedure were analyzed.Mean diameter (+/- SEM) of specimens resected with the soft cap was larger: 22.1 (+/- 0.7) versus 15.8 (+/- 0.3) mm (p0.001). The specimen was also thicker: 1.54 (+/- 0.10) versus 1.08 (+/- 0.11) mm (p0.001). Use of the soft cap led to higher rate of en bloc resection: 66.7% versus 43.2% (p0.05). The operability of the endoscope with the larger, softer cap attached was similar to that when the hard cap was used. Both caps were equally safe.The soft cap is safe and useful for mucosal resection of larger gastric lesions. Its use increases the rate of en bloc resection.

Intravital microscopy coupled with chronic animal window models has provided stunning insight into tumor pathophysiology, including gene expression, angiogenesis, cell adhesion and migration, vascular, interstitial and lymphatic transport, metabolic microenvironment and drug delivery. However, the findings to date have been limited to the tumor surface (150 microm). Here, we show that the multiphoton laser-scanning microscope can provide high three-dimensional resolution of gene expression and function in deeper regions of tumors. These insights could be critical to the development of novel therapeutics that target not only the tumor surface, but also internal regions.

Background/Aims: Cytokine-induced neutrophil chemoattractant (CINC/gro), a member of interleukin-8 family, was found as a potent chemotactic factor for rat neutrophils. Although several chemokines have been shown to be potent regulators of T cell chemotaxis in vitro, the potential role of chemokines in T-cell migration in gut-associated lymphoid tissues has not been investigated in vivo. In the present study, the effects of CINC/gro on T-lymphocyte migration were examined in rat Peyer’s patches. Methods: T lymphocytes collected from intestinal lymph of rats were fluorescence-labeled and injected into the jugular vein. Peyer’s patches of the recipient rats were observed with intravital fluorescence microscopy and the effects of CINC/gro infusion was investigated. Lymphocyte flux in mesenteric collecting lymphatics was also observed. Results: In vivo infusion of CINC/gro significantly attenuated the initial lymphocyte interaction with postcapillary venules of Peyer’s patches. However, once these lymphocytes adhered to venules, CINC/gro treatment significantly accelerated the transendothelial migration of T lymphocytes and they also significantly increased their subsequent flux in collecting lymphatics. Conclusion: There is a possibility that CINC/gro could modulate the characteristics of T lymphocyte homing in the inflammatory sites of gut.

Background & Aims: Although nitric oxide (NO) is known to influence the recruitment of neutrophils in inflamed tissue, its role in lymphocyte-endothelial cell interactions remains poorly understood. The objectives of this study were to assess the effects of NO synthesis inhibition on T-lymphocyte migration in microvessels of rat small intestine and to define the role of adhesion molecules in this process. Methods: T lymphocytes collected from rat intestinal lymph were labeled with carboxyfluorescein diacetate succinimidyl ester and injected into the jugular vein of recipient rats. The migration of T lymphocytes into normal and N G -nitro-L-arginine methyl ester (L-NAME)-treated intestinal microvessels was monitored by using an intravital microscope. Results: L-NAME significantly increased rolling and adherence of lymphocytes in postcapillary venules of Peyer's patches and submucosal venules without significantly decreasing red blood cell velocity. The subsequent appearance of lymphocytes in the initial lymphatics was also accelerated by L-NAME. Anti–α4-integrin antibody markedly inhibited the L-NAME–induced lymphocyte-endothelial cell interaction. Anti–P-selectin monoclonal antibody also significantly attenuated these adhesive interactions in both vascular regions. Conclusions: These data suggest that NO is an important modulator of lymphocyte migration in Peyer's patches and in nonlymphoid regions of the intestine. GASTROENTEROLOGY 1998;115:618-627

症例は61歳, 男性. 数日間の連続飲酒の後, 激しい腹痛, 嘔吐が出現した. 動脈血ガス分析でpH6.735, HCO3-0.9と著明な代謝性アシドーシスを認め, 尿糖陰性, 尿ケトン陽性, アニオンギャップ (AG) 51.1mEq/Lと開大しておりアルコール性ケトアシドーシス (AKA) と診断, 大量補液など保存的治療によりアシドーシス, 腹痛ともに速やかに改善した. AKAは大酒家の連続飲酒に飢餓, 脱水が加わり発症する代謝異常であるが, 臨床現場における本疾患についての認識は必ずしも高くなく, 注意を要する.

RANTES (regulated on activation, normal T cell expressed and secreted) is a member of a large supergene family of proinflammatory cytokines called C-C chemokines and it is expressed by T lymphocytes, fibroblasts, endothelial cells, platelets, mesangial cells, and renal tubular epithelial cells. RANTES is chemotactic for eosinophils, basophils, monocytes/ macrophages, and CD4 + memory T cells. This chemokine plays an important role in allergic inflammation and autoimmune responses in a variety of diseases, such as asthma and rheumatoid arthritis. However, there have been few studies on RANTES in liver disease. In an attempt to assess the relationships between plasma RANTES levels and the stages of primary biliary cirrhosis (PBC), the present study was designed to measure plasma RANTES levels in plasma by the ELISA in patients with PBC and chronic hepatitis C (CHC) and liver cirrhosis (LC) and in healthy subjects. Plasma RANTES levels in patients with PBC were significantly higher than in those with LC and in healthy subjects. They were also significantly higher in stages I and II of PBC (group A) than in stages III and IV of PBC (group B). There was a significant correlation between peripheral eosinophil counts and plasma RANTES levels. A significant correlation was also noted between the grade of eosinophil infiltration and the plasma RANTES levels. It was concluded RANTES plays an important role in the early stages of PBC.

BACKGROUND & AIMS: Although dietary fat is known to modulate immune functions, there is a paucity of data concerning the effects of fat absorption on migration of lymphocytes in intestinal lymphoid tissue. The objective of this study was to assess the influence of fat absorption on T-lymphocyte migration in Peyer's patches. METHODS: T lymphocytes collected from rat intestinal lymph were labeled with carboxyfluorescein diacetate succinimidyl ester and injected into the jugular vein of recipient rats. Olive oil or octanoic acid was placed into the duodenum, and Peyer's patch microcirculation was observed by intravital fluorescence microscopy. RESULTS: Rolling and adherence of lymphocytes in postcapillary venules were noted in both fasted and fed rats. However, lymphocyte adherence was significantly greater in olive oil-fed rats than in fasted rats. Olive oil also significantly increased the transendothelial migration of T lymphocytes. Octanoic acid stimulated lymphocyte rolling but did not affect lymphocyte adherence. Olive oil enhanced the expression of both alpha4-integrin and L-selectin on lymphocytes, whereas octanoic acid only increased the expression of L-selectin. CONCLUSIONS: Lymphocyte rolling and adherence are enhanced by olive oil feeding, possibly through an interaction between activated adhesion molecules on lymphocytes and counter- receptors on endothelial cells. (Gastroenterology 1997 Mar;112(3):813-25)

It is postulated that an enhanced production of nitric oxide by inflamed intestine plays a role in the pathophysiology of active inflammatory bowel disease. In this study, systemic NOx concentrations and colonic nitric oxide synthase activity were determined in patients with ulcerative colitis or Crohn's disease. The relationship between these two parameters and disease activity, as well as differences in nitric oxide synthase activity between ulcerative colitis and Crohn's disease, were areas of specific focus. Patients with active ulcerative colitis and Crohn's disease had significantly elevated plasma NOx concentrations; a positive correlation was found between NOx values and inducible nitric oxide synthase activities in the active mucosa of these patients. In active ulcerative colitis, levels of inducible nitric oxide synthase were significantly elevated in both normal and inflamed mucosa, although inducible nitric oxide synthase activity was higher in the latter. These colonic inducible nitric oxide synthase activities correlated well with the results of endoscopic and histologic grading of inflammation. There was no increase in constitutive nitric oxide synthase activity in patients with active ulcerative colitis. However, constitutive nitric oxide synthase activity was significantly increased in the inflamed mucosa in patients with Crohn's disease. In Crohn's disease, elevated inducible nitric oxide synthase activity was found in both normal and inflamed mucosa, with no significant difference between the tissues. Such differences in nitric oxide production in the colonic mucosa possibly reflect the significant differences in the pathophysiology and characteristic clinical features between ulcerative colitis and Crohn's disease.

The beneficial effect of elemental diet (ED) in the treatment of Crohn's disease is reported, although the exact mechanism for this remains to be elucidated. In this study the effects of ED on intestinal inflammation were investigated in a rat model of granulomatous enteritis. Intestinal inflammation was induced by a single intramural injection of peptidoglycan-polysaccharide (PG-PS) from group A streptococci into rat ileal Peyer's patches. A single injection of PG-PS in combination with fibrinogen, which retains PG-PS at the injection site, induced severe granulomatous inflammation associated with mucosal ulceration. Immunohistochemical study and immunocytochemical analysis of the cell suspension from Peyer's patches showed accumulation of macrophages and an increase in interleukin-2 receptor (IL-2R)-positive T cells after PG-PS treatment. Chemiluminescence (ChL) activity and nitrite and nitrate (NOx) levels in the mesenteric venous blood as well as Ca(2+)-independent (inducible) nitric oxide synthase (NOS) activity in Peyer's patches were increased by PG-PS treatment. In rats fed with ED, both macroscopic and histologic damage scores were significantly decreased as compared with those in rats fed with the control diet. ED inhibited the increase in the numbers of macrophages and IL-2R-positive T cells in Peyer's patches. Increased ChL activity, NOx levels, and Ca(2+)-independent NOS activity were also reduced significantly by feeding with ED. These data suggest that ED reduces progression of PG-PS-induced chronic intestinal inflammation by modulating activation of T cells, production of nitric oxide, and generation of oxygen free radicals.

Although vasoactive intestinal peptide (VIP) has been postulated to function in modulation of T cell trafficking, the exact mechanism has not been elucidated in vivo. In the present study, the effects of VIP on T lymphocyte migration were examined in rat Peyer's patches. T lymphocytes collected from intestinal lymph of rats were labeled with carboxyfluorescein diacetate succinimidyl ester and injected into the jugular vein. Peyer's patches of the recipient rats were observed with intravital fluorescence microscopy. In vivo intra-arterial infusion of or in vitro incubation with VIP did not affect the initial lymphocyte interaction with postcapillary venules of Peyer's patches. However, these treatments with VIP significantly inhibited transendothelial migration and also significantly blocked the interstitial migration of T cells and inhibited their subsequent appearance in the interfollicular lymphatics. Treatment with adenosine 3',5'-cyclic monophosphate (cAMP)-inducing agents resulted in similar inhibitory effect on T lymphocyte migration in Peyer's patches. In conclusion, VIP has significant inhibitory effects on T lymphocyte migration in Peyer's patches, possibly mediated by elevation of the intracellular cAMP concentrations.

The anti-inflammatory mechanism of prebiotics has recently been shown to have an impact on the host immune system. DHNA from Propionibacterium freudenreichii is known to promote the proliferation of Bifidobacterium and can ameliorate colitis, although its mode of action remains unknown. In this study, we investigated whether DHNA attenuates inflammation in piroxicam-treated IL-10−/− mice, particularly focusing on the changes of the host immune mechanism. DHNA was administered to IL-10−/− mice with colitis, and the expression of adhesion molecules and mRNA levels of proinflammatory cytokines were determined. DHNA pretreatment attenuated the piroxicam-induced histological changes. The increased F4/80-positive cell infiltration and VCAM-1 expression were decreased by DHNA administration. The increased mRNA levels of proinflammatory cytokines were also suppressed by DHNA. In in vitro experiments, increased mRNA levels of proinflammatory cytokines after endotoxin exposure were decreased significantly by DHNA pretreatment in RAW264.7, a macrophage cell line, and IL-10−/− mice BMMs, whereas the expression of VCAM-1 in bEnd.3 cells, a endothelial cell line, was not affected. Taken together, these findings suggest that administration of DHNA is useful for the treatment of colitis in piroxicam-treated IL-10−/− mice and that attenuation of colitis by DHNA may partly be a result of its direct action on intestinal macrophages to inhibit proinflammatory cytokine production.

Fatty acids in our daily diet are broadly classified into cis and trans fatty acids (TFAs). TFAs are formed during the manufacturing process of hydrogenated vegetable oils such as margarine. Modern diets such as deep-fried products, frozen foods, and packaged snacks commonly include large quantities of margarine containing TFAs. Although an increased report in the effects of the diet containing TFAs on a risk factor of metabolic syndrome, diabetes mellitus, and coronary heart disease has been observed in the recent years, influence on intestinal inflammation remains unknown. This review describes pro-inflammatory effects of TFAs in our diary diet on various systemic disorders and also discusses a possible role of TFAs on gut inflammation.

Background Although the incidence of inflammatory bowel diseases (IBD) in Japan has increased, the prevalence of celiac disease is considered very low with the lowest genetic disposition. IBD is reported as the most common comorbidity because of the high positive rate of serological celiac markers. The aim of this study was to examine the current incidence of celiac disease, especially in IBD patients in Japan, where both wheat consumption and incidence of IBD have increased. Methods A total of 172 patients with IBD and 190 controls in Japan were screened for serum antibody of tissue transglutaminase and deaminated gliadin peptide. In sero-positive patients, HLA testing and upper gastrointestinal endoscopy with duodenal biopsy was performed. Some of the sero-positive patients started a gluten-restricted or unrestricted diet, and serological change was determined. Results The positivity of both serum antibodies was significantly higher in IBD and correlated with disease activity. However, no biopsy-defined or HLA-defined true celiac disease was found. A decrease in serum antibody titers was observed with a gluten-restricted diet. Conclusions Despite the increased incidence of IBD and high positivity for serum celiac antibody in Japanese IBD patients, no true-positive celiac disease was noted, suggesting the presence of gluten intolerance in these populations.

We have previously reported that serum eosinophil cationic protein (ECP_ levels are increased in primary biliary cirrhosis (PBC). However, little is known about the role of eosinophils in the pathogenesis of this disease. In this study, liver biopsy specimens obtained from 27 PBC patients (stage I: 11 cases; stage II: 9 cases; stage III: 5 cases; stage IV: 2 cases) were stained with a monoclonal antibody (EG2) produced against ECP in an attempt to elucidate whether EG2-positive eosinophils are involved in the destruction of bile duct in PBC. Needle liver biopsy specimens obtained from 24 patients with chronic hepatitis C (CHC) were used as controls. In PBC, more than 10 EG2-positive cells were noted per portal tract in 6 cases, less than 10 EG2-positive cells in 10 cases and none in 11 cases. In CHC, more than 10 EG2-positive cells were detected per portal tract in only one case, less than 10 EG2-positive cells in 3 cases and none in 20 cases. According to the semi-morphometric statistical analysis, the hepatic infiltration rate of EG2-positive activated eosinophils into the portal tract was significantly higher in PBC than in CHC. Based on the stages of PBC, the infiltration rate of EG2-positive cells was significantly higher in stages I and II than in stages III and IV. A significant correlation was found between EG2-positive cell infiltration and small round cell infiltration. These findings suggest that EG2-positive, activated eosinophils may be involved in the early stages of PBC when the inflammatory changes are localized in the portal tract. It is tentatively speculated that activated eosinophils may play a role possibly as effector cells in the immunopathogenesis of PBC.

Although lymphocyte-endothelial cell interactions represent a key step in controlling the recruitment of lymphocytes into gut-associated tissues, its dynamic process in microvessels of lymphoid (Peyer's patches) and nonlymphoid (villus) regions of the small bowel remains poorly understood. We monitored the migration of fluorescence-labeled T lymphocytes into normal and lipopolysaccharide (LPS)-inflamed rat intestinal microvessels using intravital microscopy. In Peyer's patches, T lymphocytes selectively adhered to postcapillary venules, although such selectivity was not observed in submucosal venules of villi. T lymphocytes exhibited rolling behavior followed by firm adhesion in microvessels of both the Peyer's patches and the villi, with both types of adhesive interaction being mediated by alpha 4-integrins. The enhanced rolling and adherence of lymphocytes observed in Peyer's patches and submucosal venules of villi of LPS-treated rats were preceded by a reduction in shear rate and were mediated largely by alpha 4-integrins and partly by beta 2-integrins. In capillaries of intestinal mucosa, lymphocyte adherence occurred without rolling and was independent of alpha 4-integrins. LPS also significantly increased adherence of lymphocytes to villus capillaries, which was not mediated by either alpha 4- or beta 2-integrin. These observations demonstrate significant heterogeneity of lymphocyte-endothelial cell interactions within different regions of the intestinal mucosa.

Martensitic transformations which occur in Ti-45.5Ni-5.0Cu and Ti-44.0Ni-5.0Cu-1.0Al (at%) alloys were investigated by means of electrical resistivity measurements, X-ray diffraction analysis and transmission electron microscope observation. It was found that both the two alloys transform in two steps on cooling, i.e., from the high temperature cubic phase (B2-type structure) to the orthorhombic martensite (B19-type structure), and then to the monoclinic martensite (B19'-type structure). The two-step transformations in these alloys proceed as follows. On cooling, plates of orthorhombic martensite nucleate at certain sites in the cubic matrix. While the plates of orthorhombic martensite are in growth, plates of the monoclinic martensite nucleate in the orthorhombic martensite and grow consuming it. The transformation from the orthorhombic martensite to the monoclinic martensite occurs by shearing on (001) o plane to [100] o direction. A plate of the monoclinic martensite which have grown in this way consists of thin plates of (001) m compound twin as a result of alternative shearing to [100] o and [100] o direction. It is difficult to differentiate the successive two transformations of these alloys described above by electrical resistivity measurement or X-ray diffraction because the two transformations overlap and the amount of the orthorhombic martensite in the specimen through the two-step transformation is very small.

Intestine has a well-developed lymphatic system that is closely related with its functions, such as mucosal immunological defense or absorption of nutrients. Intestinal lymphoid cells such as lymphocytes, macrophages/monocytes, or dendritic cells are continuously migrating through intestinal mucosa, thereby facilitating their immune responses. Their migrations are well controlled by well-organized molecular mechanisms including adhesion molecules, chemokines, etc. This manuscript will review how dysfunction of lymphoid cell migration is involved in intestinal inflammation, especially in the pathophysiology of intestinal bowel diseases. (*English Translation of J Jpn Coll Angiol 2008; 48: 143-149.).

Aberrant leukocyte migration has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Lemon grass is a natural herb that contains citral, which suppresses lymphocyte expression of gut homing molecules by inhibiting retinoic acid formation. We therefore hypothesized that lemon grass intake could ameliorate excess migration of leukocytes to the inflamed intestine in chronic ileitis.Migration of fluorescence-labeled T cells to microvessels in the ileal mucosa of SAMP1/Yit mice was monitored using intravital microscopy. In some mice, lemon grass solution was administered for two weeks. For evaluation of the effects on chronic ileitis, mice were treated with lemon grass for 26 weeks.Surface expression of beta7 and CCR9 on T lymphocytes was stronger in SAMP1/Yit mice than in AKR/J mice. Lemon grass treatment attenuated the surface expression of beta7-integrin and CCR9. The number of adherent lymphocytes to microvessels in chronic inflamed ileum was significantly few when lymphocytes were isolated from lemon grass treated mice. Long-term lemon grass treatment improved ileitis in SAMP1/Yit mice, which was assessed by body weight, histological changes and the infiltration of beta7-positive cells.Lemon grass ameliorated ileitis through decreasing lymphocyte migration by inhibiting beta7-expression, suggesting its therapeutic usefulness for IBD.

Microcirculation (2010) 17, 321–332. doi: 10.1111/j.1549-8719.2010.00032.x Abstract Objective: Aberrant leukocyte migration has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Lemon grass is a natural herb that contains citral, which suppresses lymphocyte expression of gut homing molecules by inhibiting retinoic acid formation. We therefore hypothesized that lemon grass intake could ameliorate excess migration of leukocytes to the inflamed intestine in chronic ileitis. Methods: Migration of fluorescence-labeled T cells to microvessels in the ileal mucosa of SAMP1/Yit mice was monitored using intravital microscopy. In some mice, lemon grass solution was administered for two weeks. For evaluation of the effects on chronic ileitis, mice were treated with lemon grass for 26 weeks. Results: Surface expression of β7 and CCR9 on T lymphocytes was stronger in SAMP1/Yit mice than in AKR/J mice. Lemon grass treatment attenuated the surface expression of β7-integrin and CCR9. The number of adherent lymphocytes to microvessels in chronic inflamed ileum was significantly few when lymphocytes were isolated from lemon grass treated mice. Long-term lemon grass treatment improved ileitis in SAMP1/Yit mice, which was assessed by body weight, histological changes and the infiltration of β7-positive cells. Conclusion: Lemon grass ameliorated ileitis through decreasing lymphocyte migration by inhibiting β7-expression, suggesting its therapeutic usefulness for IBD.

The negative signal provided by interactions of programmed death-1 (PD-1) and its ligands, B7-H1 and B7-DC, has been suggested to play an important role in tumor evasion from host immunity. Pancreas cancer patients with B7-H1 expression have a poor prognosis. B7-H1 blocking has been shown to inhibit the development of a subcutaneous tumor from a pancreas cancer cell line. In this study, we investigated the effects of B7-DC as well as B7-H1 blockade in vivo in a murine pancreatic cancer model. Pancreatic cancer cells (Panc02) were inoculated in the pancreas of C57BL/6 mice. Five weeks later, tumor sizes were measured and the mice bearing appropriate size of tumors received the following treatments. Blocking antibodies against B7-H1 or B7-DC (200 microg) were administered 3 times/week for 3 weeks. Cells infiltrating the tumors were characterized by immunohistochemistry. Effects of antibodies on cytokine and FoxP3 expression were examined by quantitative RT-PCR. In vitro cultured Panc02 cells expressed B7-H1 upon IFN-gamma stimulation. However, expression of B7-H1 and B7-DC was found mainly on CD45-positive infiltrating cells and rarely on cancer cells in vivo. Treatment with both antibodies significantly decreased tumor growth in vivo. B7-DC blockade decreased the levels of IL-10 and FoxP3, suggesting that regulatory systems are mainly inhibited at the tumor site. B7-H1 blockade increased the levels of IFN-gamma and FoxP3. Collectively, blocking of B7-H1 or B7-DC efficiently induced regression of pre-established pancreatic cancers by up-regulating IFN-gamma production and down-regulating IL-10 production at the tumor site.

A 68-years-old Japanese woman was hospitalized emergently because of hemorrhagic gastric ulcer. For the hospitalization period, elevated levels of white blood cell count, eosinophilic leucocyte count, serum IgE and positive MPO-ANCA were recognized. With considering clinical course and these laboratory findings, we diagnosed Churg-Strauss syndrome (CSS). Steroid therapy in combination with cyclophosphamide was effective. CSS is a rare disease, but we should discriminate this disease when we encounter gastrointestinal bleeding of unknown etiology, especially PPI-resistant gastric ulcer.

The appendix was long considered a redundant organ. However, thereafter, analysis of immune components of the appendix revealed that slightly fewer than one third of its cells are T cells and that normal adult appendiceal lymphocyte reactivity is predominated by helper T cells [1]. In addition, the appendix has been reported to be involved in intestinal inflammation. For example,“skip lesions”of the appendix were detected in ulcerative colitis (UC) specimens examined [2], and discontinuous appendiceal involvement was found in patients undergoing proctocolectomy for UC [3]. As regards the mechanisms in appendiceal inflammation, Bittinger et al. demonstrated a different expression of cell adhesion molecules by endothelial (EC) and mesothelial cells (MC) in the various stages of appendicitis, with early Eselectin and intercellular cell adhesion molecule-1 (ICAM-1) expression in EC, followed by vascular cell adhesion molecule (VCAM-1) in EC and MC [4], suggesting that adhesion molecules play pivotal roles in appendiceal inflammation. In addition, recently, potential roles of chemokines and their receptors in lymphocyte migration have been reported. On the other hand, preventive effects of appendectomy for UC have been reported in a clinical setting [5–8]. Moreover, in an experimental model of young T-cell receptor (TCR)-a deficient mice, removal of the appendix inhibited the induction of experimental colitis [9]. In another experimental model

Although dendritic cells (DCs) play significant roles in intestinal immune responses, little is known regarding the direct effects of luminal foods on DC functions in the intestinal mucosa. In this study, we examined the effects of fatty acids (FAs) with various chain length on the phagocytic function, antigen presentation, and chemotaxis of intestinal DCs.DCs obtained from the thoracic duct lymph of mesenteric lymphadenectomized rats were cultured with long [arachidonic acid (AA) or oleic acid] or medium (octanoic acid) chain FAs with interleukin-4 and granulocyte macrophage-colony stimulating factor. Tumor necrosis factor-alpha was added in the maturation group. Phagocytic function was examined by the intake of fluorescent microbeads. The expression of cell surface molecules was determined by immunocytochemistry or fluorescence-activated cell sorting (FACS). Antigen presentation ability was evaluated by coincubating keyhole limpet hemocyanin (KLH)-sensitized spleen lymphocytes and KLH-pulsed DCs. Migratory ability of DCs toward the chemokines CC chemokine ligand (CCL) 20 and CCL21 was also assessed.There was a maturation-induced decrease in phagocytic function, and an increased expression of major histocompatibility complex (MHC) class II molecules. Exposure of DCs to both long- and medium-chain FAs maintained phagocytic ability. The expression of MHC class II molecules was significantly suppressed only by long-chain FAs. The expression of costimulatory factors was suppressed only by AA. Long- but not medium-chain FAs suppressed the antigen presentation ability of DCs induced by maturation. Chemotactic ability of mature DCs toward CCL21 was abrogated only by long-chain FAs.The data suggest that intraluminal exposure to long- and medium-chain FAs may differentially modulate the immune functions of intestinal DCs.

Summary The aetiology of Crohn's disease (CD) remains unknown. Since SAMP1/Yit mice have been reported to develop CD-like spontaneous enteric inflammation, such mice have been studied as an animal model of CD. In this study, using this model we examined T lymphocyte migration in microvessels of intestinal mucosa in vivo and the expression of adhesion molecules by immunohistochemistry. Fluorescence-labelled T lymphocytes isolated from AKR/J (control) mice were injected into the tail veins of recipient mice, and T lymphocyte migration in the postcapillary venules of Peyer's patches, submucosal microvessels, and villus capillaries of the terminal ileum was monitored using an intravital microscope. Adhesion of T lymphocytes was significantly increased in 35 week old SAMP1/Yit mice compared with that in AKR/J or 15 week old SAMP1/Yit mice. Immunohistochemical study showed increased infiltration of CD4, CD8 and β7-integrin-positive cells and increased expression of MAdCAM-1 and VCAM-1 in the terminal ileum of SAMP1/Yit mice. Antibodies against MAdCAM-1 and VCAM-1 significantly inhibited adhesion of T lymphocytes to microvessels of the terminal ileum, and anti-MAdCAM-1 antibody showed stronger suppressive effect than the anti-VCAM-1 antibody. Periodical administration of anti-MAdCAM-1 antibody twice a week for 7 weeks significantly ameliorated ileitis of SAMP1/Yit mice, but submucosal hypertrophy was not significantly suppressed. Anti-VCAM-1 antibody treatment failed to show significant resolution of ileitis. In addition, anti-MAdCAM-1 antibody treatment also attenuated established ileitis. The results demonstrate that, although MAdCAM-1 and VCAM-1 play an important role in T lymphocyte–endothelial cell interactions in SAMP1/Yit mice, MAdCAM-1 may be a more appropriate target for therapeutic modulation of chronic ileitis.

SummaryAlthough enhanced lymphocyte trafficking is associated with colitis formation, little information about its regulation is available. The aim of this study was to examine how the murine liver and activation-regulated chemokine (mLARC/CCL20) contributes to lymphocyte recruitment in concert with vascular adhesion molecules in murine chronic experimental colitis. T and B lymphocytes isolated from the spleen were fluorescence-labelled and administered to recipient mice. Lymphocyte adhesion to microvessels of the colonic mucosa and submucosa was observed with an intravital microscope. To induce colitis, the mice received two cycles of treatment with 2% dextran sodium sulphate (DSS). In some of the experiments antibodies against the adhesion molecules or anti-mLARC/CCL20 were administered, or CC chemokine receptor 6 (CCR6) of the lymphocytes was desensitized with excess amounts of mLARC/CCL20. Significant increases in T and B cell adhesion to the microvessels of the DSS-treated mucosa and submucosa were observed. In chronic colitis, the accumulation of lymphocytes was significantly inhibited by anti-mucosal addressin cell adhesion molecule (MAdCAM)-1 mAb, but not by anti-vascular cell adhesion molecule-1. In DSS-treated colonic tissue, the expression of mLARC/CCL20 was significantly increased, the blocking of mLARC/CCL20 by monoclonal antibody or the desensitization of CCR6 with mLARC/CCL20 significantly attenuated the DSS-induced T and B cell accumulation. However, the combination of blocking CCR6 with MAdCAM-1 did not further inhibit these accumulations. These results suggest that in chronic DSS-induced colitis, both MAdCAM-1 and mLARC/CCL20 may play important roles in T and B lymphocyte adhesion in the inflamed colon under flow conditions.

The pathogenesis of Crohn's disease (CD) is not known. However, monocytes and macrophages are thought to play important roles in the development of mucosal inflammation. Therefore, in this study, we examined the role of monocyte-endothelial cell interactions in senescence-accelerated mouse P1 (SAMP1)/Yit mice, a murine model of spontaneous ileitis. Fluorescence-labeled CD14+ monocytic cells isolated from the spleen and mesenteric lymph nodes of AKR/J (control) mice were injected into the tail veins of recipient (AKR/J and SAMP1/Yit) mice, and migration in the postcapillary venules (PCV) of Peyer's patches, submucosal venules, and villus microvessels of the terminal ileum was monitored by using an intravital microscope. Rolling and adhesion of CD14+ monocytic cells in the PCV of Peyer's patches and microvessels of the terminal ileum were increased in SAMP1/Yit mice. An imunohistochemical study showed increased expression of P-selectin glycoprotein-1 (PSGL-1), P-selectin, and vascular cell adhesion molecule-1 in the terminal ileum of SAMP1/Yit mice. Antibodies against these three adhesion molecules significantly inhibited adhesion of CD14+ monocytic cells to the PCV of Peyer's patches and microvessels of the terminal ileum, treatment with an anti-PSGL-1 monoclonal antibody (mAb) showing the strongest suppressive effect. Anti-PSGL-1 mAb also attenuated T cell adhesion in microvessels of intestinal mucosa. In addition, periodical administration of an anti-PSGL-1 mAb for 7 weeks significantly ameliorated ileitis of SAMP1/Yit mice. The results suggest that PSGL-1-P-selectin interaction plays an important role in monocyte-endothelial cell interactions and the development of ileitis in a murine model of CD and that the blockade of this adhesion molecule may be a novel strategy for treating CD.

Interaction of the envelope glycoprotein of hepatitis C virus (HCV) with a cellular receptor(s) is thought to be essential for the initial steps of HCV infection. However, the mechanisms of HCV infection remain unclear. The aim of the present study was to determine the features of HCV that enable efficient entry of the virus into human hepatocytes. Variations of hypervariable region 1 (HVR1) sequences in HCV inocula and in infected human hepatoblastoma HepG2 cells were examined. Immunofluorescence of inoculated HepG2 cells with anti-HCV core antibodies demonstrated that HCV structural proteins were expressed in the cytoplasm, and their entry into HepG2 cells was confirmed. When the HVR1 amino acid sequences were compared, HVR1 quasispecies in the inoculated cells showed more uniformity than those of the inocula. Although there were no statistically significant differences between the two groups, hydrophobic residues were observed more frequently in the HVR1 amino acids from inoculated cells than in the HVR1 amino acids from the inocula. Results of hydropathy analysis revealed that highly hydrophobic domains exist in the middle of HVR1 in the inoculated cells in 7 of 10 patients. The results suggest that limited HCV populations are able to enter HepG2 cells and that the highly hydrophobic domain existing within the HVR1 may play an important role in the entry of HCV into cells.

Nociceptin/orphanin (Noc/oFQ), endogenous agonist for nociceptin receptor (NOR), is thought to be a stimulator of neurogenic inflammation. We investigated the possible role of Noc/oFQ in the development of colitis using NOR-deficient mice treated with dextran sulfate sodium (DSS). Colitis was significantly improved in NOR-deficient mice against wild-type mice. Expression level of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) and infiltrating cells also significantly decreased in NOR-deficient mice against wild-type mice. Nociceptin expression increased in wild-type mice after DSS treatment. These results suggest stimulation by Noc/oFQ deteriorates colonic inflammation via up-regulation of adhesion molecule.

SUMMARY Although monocyte–endothelial cell interactions represent an initial step in controlling the recruitment of monocytes in inflamed tissues, their dynamic processes in microvessels of lymphoid (Peyer's patches) and non-lymphoid (villus) regions in gut-associated lymphoid tissue remain poorly understood. We monitored the migration of fluorescence-labelled monocytes derived from the spleen in intestinal microvessels with or without lipopolysaccharide (LPS) treatment and investigated the role of adhesion molecules, P-selectin, vascular cell adhesion molecule (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). In control mice, there were few interactions between infused monocytes and the endothelium of intestinal microvessels. The monocyte–endothelial interactions (both rolling and adhesion) were significantly increased in intestinal microvessels of LPS-treated mice compared with those in controls. Anti-P-selectin monoclonal antibody (MoAb) significantly suppressed the LPS-induced increase in monocyte rolling in postcapillary venules of Peyer's patches and submucosal venules. Anti-VCAM-1 MoAbs significantly suppressed the LPS-induced increase in monocyte adhesion to postcapillary venules (PCVs) of Peyer's patches, submucosal venules, and villus capillaries. In contrast, anti-ICAM-1 MoAb significantly suppressed the number of adherent monocytes in PCV of Peyer's patches but not in submucosal venules or villus capillaries. These observations demonstrated that LPS treatment resulted in a significant increase in recruitment of monocytes both in microvessels of lymphoid and non-lymphoid regions and that P-selectin, VCAM-1 and ICAM-1 appeared to play important roles in LPS-induced interactions.

Few models have described a chronic food allergy with morphological changes in the intestinal mucosa. Here we established an ovalbumin (OVA)-induced, cell-mediated, allergic rat model and examined lymphocyte migration in the gut. Brown Norway rats were intraperitoneally sensitized to OVA and then given 10 mg OVA/day by gastric intubation for 6 wk. Lymphocyte subsets and adhesion molecules were examined immunohistochemically, and the migration of T lymphocytes to microvessels of Peyer's patches and villus mucosa was observed by using an intravital microscope. Serum OVA-specific IgG and IgE levels were increased in animals repeatedly exposed to OVA. Significant villus atrophy and increased crypt depth was accompanied by increased infiltration of T lymphocytes in the small intestinal mucosa of the group given OVA. Expression of rat mast cell protease II and of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) was also increased in these groups. The administration of anti-MAdCAM-1 antibody significantly attenuated the OVA-induced changes in the mucosal architecture and in CD4 T lymphocyte infiltration. Intravital observation demonstrated that in rats with a chronic allergy, T lymphocytes significantly accumulated in villus microvessels as well as in Peyer's patches via a MAdCAM-1-dependent process. Our model of chronic food allergy revealed that lymphocyte migration was increased with MAdCAM-1 upregulation.

The objectives of this study were to investigate the effects of anti-vascular endothelial growth factor (VEGF) treatment on various vascular functions, gene expression, and growth of orthotopic human pancreatic cancer xenografts and thus to provide useful preclinical data for novel cancer treatments.Small pieces of a human pancreatic carcinoma, PANC-1, were implanted into the pancreas of male severe combined immunodeficient mice. The animals were treated with anti-human VEGF antibody A.4.6.1 (300 micro g, every 3 days i.p.) or a nonspecific IgG between 4 and 8 weeks after tumor implantation. Then, vascular density, diameter, permeability, and tumor growth were determined by intravital microscopy. Subsequently, tumors were harvested, and angiogenic gene expression profile was determined by a microarray kit including 96 genes involved in tumor angiogenesis.Anti-VEGF antibody significantly reduced angiogenesis and growth of orthotopic PANC-1 tumors. In the anti-VEGF treatment group, the vessel density was significantly smaller (67.8 +/- 10.6 cm/cm(2)) than that seen in the control group (146.7 +/- 10.0 cm/cm(2)). However, vessel diameter and permeability were not altered significantly by anti-VEGF antibody treatment. The pancreatic tumors in the treated group were significantly smaller than those in the control group. Microarray and subsequent Northern blot and semiquantitative reverse transcription-PCR analyses revealed both a decrease (fibroblast growth factor 1, transforming growth factor beta1, platelet-derived growth factor alpha, erbB2, and c-ets1,) and an increase (placenta growth factor, hypoxia-inducible factor alpha, and endoglin) in expression of angiogenesis-related genes in the PANC-1 tumors by anti-VEGF treatment.Anti-VEGF antibody treatment has differential effects on vessel functions as well as angiogenic gene expression and inhibitory effects on angiogenesis and growth of the orthotopic pancreatic tumor. Anti-VEGF strategy appears promising for pancreatic cancer treatment.

Relatively little is known about how recirculation of lymphocytes through the inflamed intestinal mucosa is regulated. The aim of this study was to investigate the dynamic process of T lymphocyte-endothelial cell adhesion in TNF-α-challenged murine colonic mucosa by intravital microscopy. T lymphocytes from spleen (SPL) and intestinal lamina propria (LPL) were fluorescence labeled, and their adhesion to microvessels in the colonic mucosa was observed. In TNF-α (25 μg/kg)-stimulated colonic venules, an enhanced adhesion of SPL and LPL was demonstrated, with dominant recruitment of LPLs. The magnitude of the increased LPL adhesion was more significant in the colon than in the small intestine. These T lymphocyte interactions in the colonic mucosa were significantly reduced by blocking MAbs against either mucosal addressin cell adhesion molecule-1 (MAdCAM-1), VCAM-1, α4-integrin, or β7-integrin but not by anti-ICAM-1. Immunohistochemistry revealed significant MAdCAM-1 expression in the lamina propria and VCAM-1 expression in the submucosa of TNF-α-treated colon. Spatial heterogeneity of MAdCAM-1 and VCAM-1 activation following TNF-α challenge may promote specific T lymphocyte recruitment in the inflamed colonic mucosa.

Galectin-3, a multifunctional beta-galactocide binding lectin possibly participates in a variety of biological events including cell proliferation, differentiation, and apoptosis. The implication of galectin-3 during malignancy progression has been suggested in several cancers, including colon, prostate, thyroid, and breast cancer, however, scarce data are available in gastric cancer. We examined the expression of galectin-3 in 86 primary gastric cancers and the 40 metastatic lymph nodes by immunohistochemistry to explore whether it is related to the malignant progression. Positive galectin-3 expression was observed in 84% of the gastric cancer cases. In enhanced cells of cancerous lesions, 48% showed stronger nuclear immunoreactivity than cytoplasmic one, whereas adjacent epithelial cells showed little or weak nuclear immunoreactivity. When galectin-3 expression in gastric carcinoma was compared with that in gastric tissues adjacent to the cancers, there was a significant difference. The degree of enhancement of immunoreactivity was different corresponding to various histopathological subtypes in cancer tissues. A significantly stronger expression of galectin-3 in cancer tissues was only observed in papillary and poorly differentiated adenocarcinoma. When galectin-3 expression and tumor progression (TNM staging) was compared, a significant correlation was observed in overall cases, and only in poorly differentiated adenocarcinoma the galectin-3 expression correlated with tumor progression among various subtypes. Galectin-3 expression was observed significantly stronger in metastatic lymph nodes than in the primary gastric cancers, and also in these cases among histological subtypes, only in poorly differentiated adenocarcinoma, the expression of galectin-3 in metastatic lymph nodes was stronger than the primary cancer. In conclusion galectin-3 might be a useful tumor marker for gastric cancers with respects to tumor progression and potentiality of lymph node metastasis especially in certain histological types of gastric cancer.

The host microenvironment differs between primary and metastatic sites, affecting gene expression and various physiological functions. Here we show the differences in the physiological parameters between orthotopic primary and metastatic breast tumor xenografts using intravital microscopy and reveal the relationship between angiogenic gene expression and microvascular functions in vivo.ZR75-1, a human estrogen-dependent mammary carcinoma, was implanted into the mammary fat pad (primary site) of ovariectomized SCID female mice carrying estrogen pellets. The same tumor line was also grown in the cranial window (metastasis site). When tumors reached the diameter of 2.5 mm, angiogenesis, hemodynamics, and vascular permeability were measured by intravital microscopy, and expression of angiogenic growth factors was determined by quantitative reverse transcription-PCR.ZR75-1 tumors grown in the mammary fat pad had higher microvascular permeability but lower vascular density than the same tumors grown in the cranial window (2.5- and 0.7-fold, respectively). There was no significant difference in RBC velocity, vessel diameter, blood flow rate, and shear rate between two sites. The levels of vascular endothelial growth factor (VEGF), its receptors VEGFR1 and VEGFR2, and angiopoietin-1 mRNA tended to be higher in the mammary fat pad tumors than in the cranial tumors (1.5-, 1.5-, 3-, and 2-fold, respectively).The primary breast cancer exhibited higher vascular permeability, but the cranial tumor showed more angiogenesis, suggesting that the cranial environment is leakage resistant but proangiogenic. Collectively, host microenvironment is an important determinant of tumor gene expression and microvascular functions, and, thus, orthotopic breast tumor models should be useful for obtaining clinically relevant information.

Pancreatic cancer has a poor prognosis, and treatment strategies based on preclinical research have not succeeded in significantly extending patient survival. This failure likely stems from the general lack of information on pancreatic tumor physiology, attributable to the difficulties in developing relevant, orthotopic models that accurately reflect pancreatic cancer in the clinic. To overcome this limitation, we developed abdominal wall windows suitable for intravital microscopy that allowed us to monitor angiogenesis and microvascular function noninvasively during tumor growth in vivo. We used two complementary tumor models in mice: orthotopic (human ductal pancreatic adenocarcinoma, PANC-1, grown in the pancreas), and ectopic (PANC-1 grown in the abdominal wall). We found that orthotopic PANC-1 tumors grew faster than the ectopic tumors and exhibited metastatic spread in the late stage similar to advanced pancreatic cancer in the clinic. Orthotopic PANC-1 tumors expressed vascular endothelial growth factor (VEGF)(121) and VEGF(165), contained higher levels of tumor cell-derived VEGF protein, and maintained vascular density and hyperpermeability during exponential tumor growth. Orthotopic PANC-1 tumors showed lower leukocyte-endothelial interactions in the early stage of growth. In addition, both VEGF(121) and VEGF(165) promoted the growth of PANC-1 cells in vitro. Finally, Anti-VEGF neutralizing antibody inhibited angiogenesis and tumor growth of PANC-1 tumors in both sites. We conclude that the orthotopic pancreas microenvironment enhances VEGF expression, which stimulates growth of PANC-1 tumors (compared with ectopic tumors). The mechanism is autocrine and/or paracrine and also is involved in the maintenance of blood vessels. This comparative system of orthotopic and ectopic pancreatic cancer will provide the rigorous understanding of pancreatic tumor pathophysiology needed for development of novel therapeutic strategies.

Conventional epifluorescence microscopy coupled with chronic animal window models has provided stunning insight into tumor pathophysiology, including gene expression, angiogenesis, interstitial transport, and drug delivery. However, the findings to date have been limited to the tumor surface (

Endothelin (ET), a vasoconstrictive peptide, is known to have a variety of biological actions. Although ET is released by vascular endothelial cells, other cell populations also have been reported to synthesize and release ET. In this study, we examined whether ET is synthesized by intestinal epithelial cells and whether it affects induction of epithelial cell proliferation by interleukin-2 (IL-2). Subconfluent monolayers of intestinal epithelial cells (IEC-6 and IEC-18) were maintained in serum-free medium before addition of rat IL-2. Both IEC-6 and IEC-18 cells released ET-1 into the medium under unstimulated conditions, as determined by a sandwich ELISA. IL-2 significantly enhanced ET-1 release in a time-dependent manner. ET-3 was not detectable in the culture media of either cell line. Expression of ET-1 and ET-3 mRNA in epithelial cells was assessed by competitive PCR. Both cell lines were shown to express ET-1 mRNA, but no ET-3 mRNA was detected. IL-2 treatment enhanced ET-1 mRNA expression by both IEC-6 and IEC-18 cells. Both cell lines also expressed mRNA for ETAand ETBreceptor subtypes. When cell proliferation was assessed, exogenous ET-1 induced a slight proliferative response in both types of cells that was consistent and significant at low ET-1 concentrations; cell growth was inhibited at a higher concentration (10−7M). IL-2 produced a significant proliferative response in both cell lines. However, the addition of ET-1 (10−7M) to culture media attenuated the IL-2-induced increase in cell proliferation. ETA-receptor antagonists significantly enhanced cellular proliferation, suggesting involvement of the ETAreceptor in modulation of IL-2-induced intestinal epithelial cell growth.

Background & Aims: The basic mechanisms of food allergies are still unknown. The aims of this study were to investigate whether endothelins (ETs) in the intestinal mucosa are involved in the pathogenesis of intestinal anaphylaxis. Methods: Sprague–Dawley rats were sensitized to chicken egg albumin (EA) by intraperitoneal injection. Fourteen days after sensitization, EA was administered in the jejunal segments to induce intestinal anaphylaxis. Net water outflux and histamine release into loops and serum concentrations of rat mast cell protease II (RMCP-II) were determined. ET-1 and ET-3 concentrations in the jejunal mucosa were determined, and expression of the corresponding messenger RNAs was examined by competitive polymerase chain reaction. Results: In sensitized animals, challenge with intraluminal antigen caused a significant increase in net water outflux and histamine release together with an elevation of serum RMCP-II concentrations. Mucosal concentrations of ET-1 and ET-3 and expression of their messenger RNAs were significantly increased in sensitized animals after EA challenge. Treatment with an ET A -receptor antagonist, but not an ET B -receptor antagonist, attenuated the increase in net water outflux, histamine release, and serum RMCP-II concentrations in rats with EA-induced intestinal anaphylaxis. Conclusions: Release of ETs in the intestinal mucosa increased in sensitized animals after EA challenge. ETs may play a significant role in the development of intestinal anaphylaxis via an ET A receptor. GASTROENTEROLOGY 1998;115:348-356

Background—Increased production of reactive metabolites of oxygen and nitrogen has been implicated in chronic inflammation of the gut. The object of this study was to examine the magnitude and location of nitric oxide synthase (NOS) activity and peroxynitrite formation in the colonic mucosa of patients with ulcerative colitis in relation to the degree of inflammation.Subjects—Thirty three patients with active ulcerative colitis (17 with mild or moderate inflammation, 16 with severe inflammation).Methods—Inducible NOS activity was determined in the colonic mucosa by measuring the conversion ofl-arginine to citrulline in the absence of calcium. The localisation of NOS and nitrotyrosine immunoreactivity was assessed immunohistochemically using the labelled streptavidin biotin method.Results—Inducible NOS activity increased in parallell with the degree of inflammation of the mucosa. Expression of inducible NOS was found not only in the lamina propria, but also in the surface of the epithelium. Peroxynitrite formation as assessed by nitrotyrosine staining was frequently observed in the lamina propria of actively inflamed mucosa.Conclusions—Nitric oxide and peroxynitrite formation may play an important role in causing irreversible cellular injury to the colonic mucosa in patients with active ulcerative colitis.