Interleukin 1beta-induced production of H2O2 contributes to reduced sigmoid colonic circular smooth muscle contractility in ulcerative colitis.

We have shown that neurokinin A-induced contraction of human sigmoid circular muscle (HSCM) is reduced in patients with ulcerative colitis and that interleukin (IL)-1beta may play a role in this change. We now examine changes in the signal transduction pathway mediating neurokinin A-induced contraction of HSCM and explore the role of IL-1beta and of H(2)O(2) in these changes. In Fura 2-AM-loaded ulcerative colitis HSCM cells, neurokinin A- and caffeine-induced peak Ca(2+) increase and cell shortening were significantly reduced. In normal cells, neurokinin A-induced contraction was decreased by protein kinase C inhibitor chelerythrine and by calmodulin inhibitor CGS9343B [1,3-dihydro-1-[1-[(4-methyl-4H,6H-pyrrolo[1,2-a][4,1]-benzoxazepin-4-yl)methyl]-4-piperidinyl]-2H-benzimidazol-2-one (1:1) maleate]. In ulcerative colitis muscle cells, contraction was inhibited only by chelerythrine but not by CGS9343B. IL-1beta treatment of normal HSCM strips and cells reproduced the changes observed in ulcerative colitis. IL-1beta-induced reduction in caffeine-induced peak Ca(2+) increase and contraction was reversed by catalase, suggesting a role of H(2)O(2). IL-1beta-induced H(2)O(2) production was inhibited by mitogen-activated protein kinase (MAPK) kinase inhibitor PD98059 (2'-amino-3'-methoxyflavone) and by cytosolic phospholipase A2 (cPLA(2)) inhibitor AACOCF3 (arachidonyltrifluoromethyl ketone), but neither by p38 MAPK inhibitor SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole] nor by nuclear factor-kappaB (NF-kappaB) inhibitory peptide NF-kappaB SN50 (H-Ala-Ala-Val-Ala-Leu-Leu-Pro-Ala-Val-Leu-Leu-Ala-Leu-Leu-Ala-Pro-Val-Gln-Arg-Lys-Arg-Gln-Lys-Leu-Met-Pro-OH). IL-1beta significantly increased the phosphorylation of extracellular signal-regulated kinase 1 (ERK1)/ERK2 MAPKs and cPLA(2) and IL-1beta-induced cPLA(2) phosphorylation was blocked by PD98059. We conclude that Ca(2+) stores of HSCM cells may be reduced in ulcerative colitis and that the signal transduction pathway of neurokinin A-induced contraction switches from calmodulin- and protein kinase C-dependent in normal cells to protein kinase C-dependent in ulcerative colitis cells. IL-1beta reproduces these changes, possibly by production of H(2)O(2) via sequential activation of MAPKs (ERK1/ERK2) and cPLA(2).

Gracilis muscle transposition for iatrogenic rectourethral fistula.

OBJECTIVE: To assess the utility of gracilis muscle transposition in the treatment of iatrogenic rectourethral fistula. SUMMARY BACKGROUND DATA: Iatrogenic rectourethral fistula poses a rare but challenging complication of treatment for prostate cancer. A variety of procedures have been described to treat this condition, none of which has gained acceptance as the procedure of choice. The aim of this study was to review the authors' experience with gracilis muscle transposition in the treatment of iatrogenic rectourethral fistula. METHODS: A retrospective chart review of all patients who underwent gracilis muscle transposition for iatrogenic rectourethral fistula was performed, and follow-up was established by telephone interview. Successful repair was defined as absence of a fistula after reversal of fecal and urinary diversions. RESULTS: Eleven men, mean age of 62 years, underwent 12 gracilis muscle transpositions for rectourethral fistula between 1996 and 2001. Six patients had a history of pelvic radiotherapy, and five patients had previous failed attempts to repair the fistula. In nine patients, the fistula healed following gracilis muscle transposition. One patient developed a rectocutaneous fistula that healed with fibrin glue injection, and one developed perineal sepsis requiring debridement of the transposed gracilis. This patient underwent a second gracilis transposition, which uneventfully healed. Overall, all of the patients had closure of their diverting stomas and maintained healed rectourethral fistulas. There were no intraoperative complications, and the only long-term complication of this procedure was mild medial thigh numbness in two patients. CONCLUSIONS: Gracilis muscle transposition is an effective surgical treatment for iatrogenic rectourethral fistula. It is associated with low morbidity and a high success rate.

A study to determine the nitroglycerin ointment dose and dosing interval that best promote the healing of chronic anal fissures.

PURPOSE: The aim of this study was to determine the optimal dose and dosing interval of nitroglycerin ointment to heal chronic anal fissures. METHOD: A randomized, double-blind study of intra-anally applied nitroglycerin ointment (Anogesic) was conducted in 17 centers in 304 patients with chronic anal fissures. The patients were randomly assigned to one of eight treatment regimens (0.0, 0.1, 0.2, 0.4 percent nitroglycerin ointment applied twice or three times per day), for up to eight weeks. A dose-measuring device standardized the delivery of 374 mg ointment. Healing of fissures (complete reepithelialization) was assessed by physical examination using an observer unaware of treatment allocation. The subjects assessed pain intensity daily by completing a diary containing a visual analog scale for average pain intensity for the day, the worst pain intensity for the day, and pain intensity at the last defecation. RESULTS: There were no significant differences in fissure healing among any of the treatment groups; all groups, including placebo had a healing rate of approximately 50 percent. This rate of placebo response was inexplicably higher than previously reported in the literature. Treatment with 0.4 percent (1.5 mg) nitroglycerin ointment was associated with a significant (P < 0.0002) decrease in average pain intensity compared with vehicle as assessed by patients with a visual analog scale. The decreases were observed by Day 4 of treatment. At 8 weeks the magnitude of the difference between 0.4 percent nitroglycerin and control was a 21 percent reduction in average pain. Treatment was well tolerated, with only 3.29 percent of patients discontinuing treatment because of headache. Headaches were the primary adverse event and were dose related. CONCLUSION: Nitroglycerin ointment did not alter healing but significantly and rapidly reduced the pain associated with chronic anal fissures.

Abnormal motility in patients with ulcerative colitis: the role of inflammatory cytokines.

HYPOTHESIS: Interleukin 1 beta (IL-1 beta) levels are elevated in the colonic mucosa of patients with ulcerative colitis (UC). We propose that IL-1 beta may also be elevated in the circular muscle layer of the colon and may be partially responsible for the motility dysfunction observed in patients with UC. DESIGN: Cohort analytic study. SETTING: Research laboratory in a tertiary academic medical center. PARTICIPANTS: Normal smooth muscle was obtained from the disease-free margins of human sigmoid colon specimens resected from patients with cancer and compared with specimens from patients with UC. INTERVENTIONS: An enzyme-linked immunosorbent assay was used to measure IL-l beta. Standard muscle chambers were used to measure force changes. Single muscle cells were isolated by enzymatic digestion, and cell shortening in response to neurokinin A (NKA) and thapsigargin was measured under a microscope. Cytosolic Ca(2+) (calcium) concentrations were measured by standard techniques. MAIN OUTCOME MEASURE: Effects of IL-1 beta on smooth muscle function in normal and UC colons. RESULTS: In patients with UC, IL-1 beta was elevated in the muscularis propria, and sigmoid circular smooth muscle contractions in response to NKA and thapsigargin were significantly reduced. In fura-2-loaded cells from patients with UC, the NKA-induced Ca(2+) signal was also significantly reduced in Ca(2+)-free medium, indicating the reduced intracellular Ca(2+) stores after UC. Exposure of normal cells to IL-1 beta mimicked the changes observed in patients with UC. An IL-1 beta-induced reduction in contraction and release of intracellular Ca(2+) in response to NKA was partially restored by the hydrogen peroxide scavenger catalase. CONCLUSION: In patients with UC, IL-1 beta was increased in colonic circular muscles and may contribute to motor dysfunction after UC through production of hydrogen peroxide.