Increased Nitric Oxide Production and Inducible Nitric Oxide Synthase Activity in Colonic Mucosa of Patients with Active Ulcerative Colitis and Crohn's Disease

It is postulated that an enhanced production ofnitric oxide by inflamed intestine plays a role in thepathophysiology of active inflammatory bowel disease. Inthis study, systemic NO_x concentrations and colonic nitric oxide synthase activity weredetermined in patients with ulcerative colitis orCrohn's disease. The relationship between these twoparameters and disease activity, as well as differences in nitric oxide synthase activity betweenulcerative colitis and Crohn's disease, were areas ofspecific focus. Patients with active ulcerative colitisand Crohn's disease had significantly elevated plasma NO_x concentrations; a positivecorrelation was found between NO_x values andinducible nitric oxide synthase activities in the activemucosa of these patients. In active ulcerative colitis,levels of inducible nitric oxide synthase were significantlyelevated in both normal and inflamed mucosa, althoughinducible nitric oxide synthase activity was higher inthe latter. These colonic inducible nitric oxidesynthase activities correlated well with the results ofendoscopic and histologic grading of inflammation. Therewas no increase in constitutive nitric oxide synthaseactivity in patients with active ulcerative colitis. However, constitutive nitric oxidesynthase activity was significantly increased in theinflamed mucosa in patients with Crohn's disease. InCrohn's disease, elevated inducible nitric oxidesynthase activity was found in both normal and inflamedmucosa, with no significant difference between thetissues. Such differences in nitric oxide production inthe colonic mucosa possibly reflect the significant differences in the pathophysiology andcharacteristic clinical features between ulcerativecolitis and Crohn's disease.     

溃疡性结肠炎中防御素、一氧化氮和丙二醛的表达

背景：溃疡性结肠炎（UC）是一种慢性非特异性肠道炎症性疾病，其病因尚不明确。近年来，防御素家族在先天免疫中的作用受到广泛关注。目的：研究UC患者结肠组织中中性粒细胞防御素人中性粒细胞肽（HNP）1-3与一氧化氮（NO）、丙二醛（MDA）的相关性，了解三者在UC发病中的作用。方法：以逆转录聚合酶链反应（RT—PCR）检测16例活动期UC患者结肠组织和10例正常结肠组织中HNP1-3mRNA的表达，分别以硝酸还原酶法和硫代巴比妥酸（TBA）显色法检测结肠组织NO和MDA水平。结果：UC患者结肠组织HNP1-3mRNA和NO、MDA的表达水平显著高于正常对照组（P〈0．01），其中UC受累黏膜又显著高于未受累黏膜（P〈0．01）。UC受累黏膜中HNP1-3mRNA与NO、MDA的表达具有显著相关性（rs^1=0．643，P〈0．01；rs^1=0．831，P〈0．01）。结论：HNP1-3可能参与了UC结肠组织的炎症损伤过程，NO和MDA可能与HNP1-3协同发挥作用。     

HLA-DR Expression and Disease Activity in Ulcerative Colitis

In 12 patients with active ulcerative colitis (UC) the rectal epithelial cells were analyzed for HLA-DR antigens by an immunohistochemical technique. The clinical, rectoscopic, and histologic stages were also determined. The investigations were carried out at the beginning of the study and 2 weeks and 3 months later. The rectal epithelial cells were HLA-DR-positive in all patients at the first two examinations. After 3 months five patients had changed to an HLA-DR-negative stage, whereas the other seven patients remained HLA-DR-positive. Closer analyses showed that expression/nonexpression of HLA-DR antigens on rectal epithelial cells of patients with UC could not be predicted from the clinical, rectoscopic, or histologic findings. HLA-DR expression is normally restricted to immunocompetent cells. The presence of HLA-DR antigens on epithelial cells may be a consequence of immunological reactions. Whether HLA-DR-positive cells have a specific function is unknown.     

Increased Protein Tyrosine Kinase Activity of the Colonic Mucosa in Ulcerative Colitis

The protein tyrosine kinase (PTK) activity was measured in the inflamed colonic mucosa of 12 patients with ulcerative colitis and in the normal colonic mucosa of 12 control patients with colon cancer. The specific PTK activity in the particulate fraction obtained from ulcerative colitis mucosa was significantly increased compared with that of normal mucosa (5.10 ± 0.60 pmol/min/mg versus 2.12 ± 0.44 pmol/ min/mg protein; p < 0.05). Inflamed ulcerative colitis mucosa also showed a significantly higher total PTK activity in the particulate fraction than normal mucosa (2.60 ± 0.42 pmol/min/g versus 0.91 ± 0.16 pmol/min/g tissue; p < 0.05). Mucosal samples from ulcerative colitis patients were divided into those with mild and those with severe inflammation on histologic examination (n - 6 each). The particulate PTK activity of severely inflamed mucosa was significantly higher than that of mildly inflamed mucosa (p < 0.05). These results suggest that colonic inflammation in ulcerative colitis is associated with alterations in cellular PTK activity.     

Acute Colonic Graft-versus-host Disease and Ulcerative Colitis with Respect to Cytokines

Colonic graft-versus-host disease (GVHD) occurring after allogeneic bone marrow transplantation (BMT) resembles ulcerative colitis (UC) with respect to pathological features. In addition, therapy for UC has been reported to be effective for the treatment of refractory GVHD. The relationship of these two conditions with respect to cytokines was investigated in the present study.

Among 27 patients who underwent allogeneic BMT during the previous two years, six developed GVHD of grade 3 or higher, and these six patients were compared with the other 21 patients.

In six patients, the levels of the following cytokines were significantly elevated at the onset of GVHD: tumor necrosis factor-α (p<0.05), interleukin-6 (p<0.05), interleukin-8 (p<0.01), interferon-γ (p<0.05), and interleukin-7 (p<0.0001).

These findings indicate that GVHD and UC are similar in terms of their cytokine profile.     

Changes in Distribution of Three Isoforms of Nitric Oxide Synthase in Ulcerative Colitis

Background: Nitric oxide (NO) has an important role both in normal physiology and pathological events of the colon. Our aim was to study possible changes of the three nitric oxide synthases in ulcerative colitis (UC). Methods: Tissue samples from normal colon and least and moderately affected regions of ulcerative colitis colon were obtained at surgery and immunostained for NOS-1, NOS-2, NOS-3, and GAP-43, a marker of nerve fibers. Quantitative analysis of NOS-1 immunoreactivity was performed on the circular muscle layer. Results: NOS-1-immunoreactive fibers in the muscularis mucosae disappeared in least affected and moderately affected UC colon. Quantitative analysis of NOS-1-immunoreactive nerve fibers in the circular muscle showed no differences between normal and diseased colon. NOS-2 immunoreactivity appeared apically in the epithelial cells. In normal colon some specimens showed immunoreactivity in lower parts of crypts. NOS-2 immunoreactivity increased according to the severity of UC. NOS-3 immunoreactivity was exclusively localized in the vascular endothelium. The difference in NOS-3 staining intensity between the lamina propria and submucosa observed in normal tissue disappeared in moderately affected UC colon. The number of NOS-3-immunoreactive vascular profiles increased in the lamina propria of UC colon. Conclusions: All three NOS isoforms show specific changes in UC colon.     

清肠栓对溃疡性结肠炎大鼠一氧化氮和一氧化氮合酶活性的影响

目的：观察不同剂量清肠栓治疗溃疡性结肠（UC）的作用及其对一氧化氮（NO）和一氧化氮合酶（NOS）活性的影响。方法：将动物随机分成高、中、低剂量清肠栓组、SASP组、模型组、空白组,除空白组外其余5组动物分别用三硝基苯磺酸（TNBS）建立大鼠溃疡性结肠炎模型,连续用药2周后取结肠组织,采用改良的G法、分光光度法分别测定其NO含量和NOS活性。结果：模型组大鼠NO、NOS含量较空白组明显降低,其他各组均有不同程度的增高,尤其以清肠栓高剂量组的增高为明显。结论：TNBS急性损伤使结肠组织的NO、NOS活性发生改变,可能是UC发生的重要机制。中药复方清扬栓具有调控NO及NOS活性的作用,是有效治疗UC的可能机制之一。     

An Index of Disease Activity in Patients with Ulcerative Colitis

Quantification of disease severity was studied in 72 patients with ulcerative colitis, who had undergone total 85 clinical courses. We performed a multiple stepwise regression analysis, according to Truelove and Witts' classification, with disease severity as a dependent variable, and with 18 clinical, laboratory, and endoscopic parameters as independent variables. Results showed that disease severity in patients with ulcerative colitis is significantly influenced by five factors, namely, bloody stool, bowel movements, erythrocyte sedimentation rate (ESR), hemoglobin (Hb), and serum albumin. The activity index (AI) developed for ulcerative colitis is expressed as follows: AI = 60 x blood stool + 13 x bowel movements + 0.5 x ESR - 4 x HB - 15 x albumin + 200. Index values below 150, values between 150 and 220, and values above 220 nearly corresponded to mild, moderate, and severe disease, respectively, in Truelove and Witts' classification. We believe that the activity index is useful in evaluation of the effect of medical treatment in patients with ulcerative colitis. Its most important value will be in therapeutic trials.     

Rectal Nitric Oxide Assessment in Children with Crohn Disease and Ulcerative Colitis. Indicator of Ileocaecal and Colorectal Affection

Background: Nitric oxide (NO) production is increased in inflammatory bowel disease (IBD). Measurements of luminal NO in Crohn disease and ulcerative colitis have revealed that levels are increased during active disease. We aim to evaluate whether rectal measurements of NO can reveal active disease of the colon as well as ileum. Methods: Sixteen children with active Crohn disease in the ileocaecal or colorectal regions of the gut and 6 children with active ulcerative colitis were compared to a group of 14 healthy children. Gaseous samples for analysis of luminal NO were collected using a Foley catheter inserted into rectum. The balloon of the catheter was filled with NO-free air and incubated for 10 min. After aspiration, samples were analysed using chemiluminescence. Values are expressed as median and range. Results: In healthy children, rectal NO values were 60 (0-275) ppb. In children with Crohn disease of the colorectal region, NO concentrations were 5,675 (300-49,350) ppb (P &lt; 0.001), while those with Crohn disease of the ileocaecal region had NO levels of 2,625 (300-15,000) ppb (P &lt; 0.01). In children with ulcerative colitis, NO values of 5,500 (950-34,000) ppb were found (P &lt; 0.001). Conclusion: Rectal NO levels are greatly increased in children with IBD. Highest values were found in patients with colorectal engagement, but rectal NO was increased also in ileocaecal disease. Rectal sampling of luminal NO is a simple and minimally invasive method and should be considered a diagnostic tool for intestinal inflammatory activity in children regardless of primary disease location.     

Psychological Stress and Disease Activity in Ulcerative Colitis: A Multidimensional Cross-sectional Study

Objectives: It is not known whether any link exists between life stress and disease activity in ulcerative colitis; attempts to demonstrate one have been complicated by recall bias, distressing psychological consequences of disease, psychogenic symptom exaggeration, and an irritable bowel component of inflammatory bowel disease symptoms. We therefore studied the relationship between psychological measures and two different aspects of ulcerative colitis activity. Methods: The relation of perceived stress, depression, state anxiety, trait anxiety, and life events with endoscopic appearance of the rectal mucosa was studied "blind" in 46 asympto-matic outpatients with known ulcerative colitis. The same measures were then examined in relation to subjective activity, comparing the group in clinical remission with 32 ulcerative colitis outpatients who reported symptoms. Results: Among asymptomatic patients, the level of stress over the past 2 yr on the General Perceived Stress Questionnaire was higher in the 11 with mucosal abnormalities than in the 35 with a normal rectal mucosa ( p = 0.004). Among the entire population, symptomatic patients were more likely to recall major life events in the previous 6 months than the asymptomatic group ( p = .02). Adjustment for smoking and for duration of remission did not substantially alter these findings. Conclusions: Life stress is associated with both objective and subjective aspects of activity in ulcerative colitis. Although the association of life events with reported symptoms may be subject to recall bias, the association of perceived stress with rectal mucosal abnormalities in asymptomatic patients is strongly suggestive of a true link between psychological factors and ulcerative colitis activity.     

The Microvacular Thrombi of Colonic Tissue in Ulcerative Colitis

Mucosal microvacular thrombi in rectal biopsies were observed in some ulcerative colitis (UC). Heparin may be effective in steroid resistant UC in some studies, however, the new results of meta-analysis demonstrated a non-significant effect of heparin in controlled clinical trials, differing markedly from observational studies. The objective of this study was to identify colonic microvascular thrombi in larger cases with UC, and analyse its possible risk factors: age, gender, histologic score, extent of lesions and operation or biopsy specimens, and assess the significance of microvascular thrombosis in patients with UC. The microvascular thrombi were identified by immunohistochemical staining with anti-CD61 monoclonal antibody and Martius scarlet blue (MSB) staining in 40 colonic tissue samples of UC (31 biopsy specimens and nine operated cases) and 12 cases of normal colon tissue from operated colonic carcinoma. Logistic regression analysis was used to assess the relationship of age, gender, degree of histology, origin of the specimens, extent of lesions and microvascular thrombi examined. Microvascular thrombi were positive in 14 of 40 UC cases, and none in the controls. The presence of microvascular thrombi was related to operation specimens with odds ratio 11.667, P=0.0179, it might be also related to histologic score (OR=1.350) and extent of lesions (OR=1.619). These results suggest that microvascular thrombosis may be one of the important pathogenesis in some UC, and that the effect of anticoagulant treatment still needs to be assessed.     

Colonic Sulfide in Pathogenesis and Treatment of Ulcerative Colitis

A role for colonic sulfide in the pathogenesisand treatment of ulcerative colitis (UC) has emergedbased on biochemical, microbiological, nutritional,toxicological, epidemiological, and therapeuticevidence. Metabolism of isolated colonic epithelial cellshas indicated that the bacterial short-chain fatty acidn-butyrate maintains the epithelial barrier and thatsulfides can inhibit oxidation of n-butyrate analogous to that observed in active UC. Sulfurfor fermentation in the colon is essential forn-butyrate formation and sulfidogenesis aids disposal ofcolonic hydrogen produced by bacteria. The numbers of sulfate-reducing bacteria and sulfidogenesisis greater in UC than control cases. Sulfide is mainlydetoxified by methylation in colonic epithelial cellsand circulating red blood cells. The enzyme activity of sulfide methylation is higher in red bloodcells of UC patients than control cases. Patients withUC ingest more protein and thereby sulfur amino acidsthan control subjects. Removing foods rich in sulfur amino acids (milk, eggs, cheese) has proventherapeutic benefits in UC. 5-Amino salicylic acidreduces fermentative production of hydrogen sulfide bycolonic bacteria, and aminoglycosides, which inhibit sulfate-reducing bacteria, are of therapeuticbenefit in active UC. Methyl-donating agents are acategory of drugs of potential therapeutic use in UC. Acorrelation between sulfide production and mucosal immune responses in UC needs to be undertaken.Control of sulfidogenesis and sulfide detoxification maybe important in the disease process of UC, althoughwhether their roles is in an initiating or promoting capacity has yet to be determined.     

Redox Imbalance in the Colonic Mucosa of Ulcerative Colitis

Perforation occurring at a remote site of the bowel after diagnostic colonoscopy is rare. A 61-year-old man presenting with bloody diarrhoea underwent colonoscopy. A dynamic ileus developed in less than 1 day, and mid-ileal perforation occurred 7 days after the procedure. It is suggested that high air pressure during colonoscopy further compromised the reduced blood flow in the mid-ileum, which had underlying chronic ischaemia, leading to perforation. Our patient constitutes the first reported case of small-bowel perforation after colonoscopy due to pre-existent ileal ischaemia.     

Vitamin D Deficiency Is Associated with Ulcerative Colitis Disease Activity

Purpose

Previous studies on experimental mouse models have suggested a role of vitamin D in immune system regulation and IBD disease severity. In this study, we examine the relationship between vitamin D levels and clinical disease activity in human subjects with ulcerative colitis (UC). We hypothesized that patients with vitamin D deficiency will display increased UC disease activity as compared to patients with normal vitamin D levels.

Methods

A cross-sectional study was performed by querying the outpatient electronic medical record of our health system for patients seen in the gastroenterology clinic from January 2007 to October 2009 who carried both a diagnosis of UC and a documented 25-OH vitamin D level within 30 days of their clinic visit. Demographic and clinical variables were collected. Clinical disease activity was calculated using the six-point partial Mayo index. Active disease was defined as a six-point index score of ≥1. Vitamin D deficiency was defined as a 25-OH D level below 30 ng/ml. Data were analyzed using the chi-square distribution test.

Results

Thirty-four patients met inclusion criteria (53 % female, mean age 45.7 ± 24.7 years). Fifteen patients had normal vitamin D levels and 19 patients were vitamin D deficient. Twelve patients had vitamin D levels <20 ng/ml. Vitamin D deficient patients were statistically more likely to have increased disease activity than patients with normal vitamin D levels (p = 0.04), with 68 % of deficient patients displaying active disease compared with 33 % in the sufficient group. There was also a statistically significant association between vitamin D status and need for treatment with steroids, with a higher percentage of vitamin D deficient patients (47 %) requiring such treatment compared with 7 % in the sufficient group (p = 0.02). There was no association between season of visit and disease activity.

Conclusion

Vitamin D deficiency is common among patients with active UC, particularly those requiring corticosteroids. Further investigation is needed to determine the clinical utility of vitamin D monitoring in patients with UC and whether there is a role for vitamin D as a treatment for UC.     

Leucocyte Scintigraphy to Localize Inflammatory Activity in Ulcerative Colitis and Crohn's Disease

Vilien M, Nielsen SL. Jørgensen M, Binder V, Hvid-Jacobsen K, Berild D, Kcltwck H. Leucocyte scintigraphy to localize inflammatory activity in ulcerative colitis and Crohn's disease. Scand J Gastroenterol 1992;27:582-586.

The validity of using autologous leucocytes labelled with technetium -99m hexamethyl-propyleneamine-oxine (Tc-HMPAO) for scintigraphy in inflammatory bowel disease was evaluated in 12 patients with clinically active ulcerative colitis (LJC) and 10 with Crohn's disease (CD). Colonoscopy and biopsy were used as reference. Scintigrams taken I h and 3 h after leucocyte reinjection were evaluated blindly by two independent observer groups. Full agreement was found in 11 of 12 UC patients when compared with colonoscopy but in only 3 of 10 CD patients. Segments with agreement in CD patients often showed neutrophilic granulocyte infiltration at biopsy. The judgements of clinicians and physiologists differed for only 2 of totally 70 UC segments but for 13 of 59 CD segments (kappa, 0.94 and 0.52), It is concluded that Tc-HMPAO scintigraphy might be an alternative to colonoscopy in the control of disease extent in UC. In CD patients the technique might warn about infectious complications.     

Colonic Luminal Hydrogen Sulfide Is Not Elevated in Ulcerative Colitis

It has been proposed that the reduction inn-butyrate oxidation by colonic epithelial cellsobserved in ulcerative colitis may be related toexposure to reduced forms of sulfur derived fromdissimilatory sulfate reduction by luminal microflora. Thisstudy aims to compare stool sulfide concentrations incontrol and colitic subjects. Control subjects hadsignificant colorectal disease excluded by virtue of their selection. Patients with ulcerativecolitis were stratified by disease extent and activity,and by salicylate drug use. Stool sulfide was measuredusing a direct spectrophotometric method on NaOH (free sulfide) and zinc acetate (total sulfide)stool slurries. Fifteen control and 19 colitic subjectswere studied. There was no significant difference instool sulfide between control and colitic patients (free sulfide, control =0.52 (0.17), colitic0.45 (0.10), t = 0.36, P = 0.71, total sulfide, control1.33 (0.21), colitic 0.96 (0.15), t = 1.44, P = 0.16).Disease extent or activity did not significantlyinfluence stool sulfide. These results do not support aprimary etiologic role for luminal sulfide in ulcerativecolitis.     

Polyamine Metabolism in Colonic Mucosa from Patients with Ulcerative Colitis

Polyamine metabolism in mucosa both from patients in the active or remission stage of ulcerative colitis (UC) and from healthy controls was studied. In the active stage of UC, mucosal spermidine concentration was higher than in remission or in the controls, but the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase, rate-limiting enzymes of polyamine biosynthesis, were lower. In the active stage of UC, the mucosal level of mRNA coding for ornithine decarboxylase was lower than in the remission stage of UC or in the controls. The activity of spermidine/spermine N1-acetyltransferase, the rate-limiting enzyme of polyamine degradation, was higher in the active stage of UC than in the remission stage of UC or in the controls. However, it seemed that this activity did not reflect the increase in the spermidine concentration. The results showed that the spermidine increase in the active stage of UC was not due to changes in the synthesis or degradation of polyamines; the increase may have been due to increased exogenous spermidine uptake.