Initial Computed Tomography Findings of Long and Distended Colon Are Risk Factors for the Recurrence of Sigmoid Volvulus.

BACKGROUND: Sigmoid volvulus is a common condition in elderly patients with elongated colons. Although endoscopic de-torsion is effective as the primary treatment of sigmoid volvulus, elective surgery is recommended because of the high risk of recurrence and high mortality rate. AIM: The aim of this study was to determine the risk factors for the recurrence of sigmoid volvulus. METHODS: Clinical records of patients treated at Shimane Prefectural Central Hospital were reviewed retrospectively. Among 41 sigmoid volvulus patients who were successfully treated by endoscopic de-torsion and followed up, 30 were observed over 1 year. Among the 30 patients, eight (26.7%) did not experience recurrence, while 22 (73.3%) did. Initial computed tomography (CT) findings indicating the sigmoid colon extending to the diaphragm or ventral to the liver were defined as "extension findings." Extension findings and sigmoid diameter were evaluated in relation to sigmoid volvulus recurrence. RESULTS: Extension findings were significantly more frequent in the recurrent group (77.3%) than in the nonrecurrent group (25.0%) (P = 0.009). Distended sigmoid colon diameter was significantly larger in the recurrent group (11.7 ± 3.8 cm) than in the nonrecurrent group (7.1 ± 1.1 cm) (P = 0.044). Receiver operating characteristic curve analysis demonstrated that the performance threshold was greater than 8.9 cm. Kaplan-Meier analysis showed the significantly high sigmoid volvulus recurrence rate in the patients with extension findings and a distended sigmoid colon greater than 8.9 cm. CONCLUSIONS: CT findings of a long and distended sigmoid colon in initial sigmoid volvulus are risk factors for the recurrence of sigmoid volvulus.

Overexpression of thioredoxin reductase 1 regulates NF-kappa B activation.

Thioredoxin reductase (TrxR) is a flavoprotein that contains a C-terminal penultimate selenocysteine (Sec) and has an ability to reduce thioredoxin (Trx), which regulates the activity of NF-kappa B. To date, three TrxR isozymes, TrxR1, TrxR2, and TrxR3, have been identified. In the present study, we found that among these isozymes only TrxR1 was induced by tumor necrosis factor-alpha (TNF alpha) in vascular endothelial cells. Furthermore, the overexpression of TrxR1 enhanced TNF alpha-induced DNA-binding activity of NF-kappa B and NF-kappa B-dependent gene expression. The catalytic Sec residue of TrxR1, which is essential for reducing Trx, was required for this NF-kappa B activation, and aurothiomalate, an inhibitor of TrxR, suppressed TNF alpha-induced activation of NF-kappa B and the expression of NF-kappa B-targeted proinflammatory genes such as E-selectin and cyclooxygenase-2. These results suggest that TrxR1 may act as a positive regulator of NF-kappa B and may play an important role in the cellular inflammatory response.