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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. The aim of this study was to determine the risk factors for the recurrence of sigmoid volvulus. 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. 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. CT findings of a long and distended sigmoid colon in initial sigmoid volvulus are risk factors for the recurrence of sigmoid volvulus.

金沢大学高度モビリティ研究所 / 金沢大学理工研究域機械工学系, Blue brittleness is exhibited by some steels after being heated to an elevated temperature. Although at high temperature a given strain is associated with a lower stress level, at the temperature at which blue brittleness is observed there is a pronounced work-hardening effect. Furthermore, the temperature at which blue brittleness occurs is a function of the strain rate. Therefore, to improve the accuracy of numerical simulations of hot or warm working which utilizes the thermal softening of steels, a dynamic constitutive equation which can model the blue brittleness phenomenon is needed. In this paper we present such a constitutive equation, which has two parts : one models the ordinary constitutive relation and the other the phenomenon of blue brittleness. Unknown material constants in the equation are determined by a non-linear least-squares method from uniaxial impact and static compressive test results. The equation is then evaluated by comparing it to experiments over a wide temperature range.

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-κB. 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-α (TNFα) in vascular endothelial cells. Furthermore, the overexpression of TrxR1 enhanced TNFα-induced DNA-binding activity of NF-κB and NF-κB-dependent gene expression. The catalytic Sec residue of TrxR1, which is essential for reducing Trx, was required for this NF-κB activation, and aurothiomalate, an inhibitor of TrxR, suppressed TNFα-induced activation of NF-κB and the expression of NF-κB-targeted proinflammatory genes such as E-selectin and cyclooxygenase-2. These results suggest that TrxR1 may act as a positive regulator of NF-κB and may play an important role in the cellular inflammatory response. © J. Cell. Physiol. 198: 22–30, 2004© 2003 Wiley-Liss, Inc.

Damage to the vascular endothelium by reactive oxygen species causes many cardiovascular diseases including atherosclerosis. Such damage can be prevented by selenium (Se), which is thought to exert its actions mainly through the expression of selenoproteins. Se deficiency increased the susceptibility to tert-butylhydroperoxide (t-BuOOH) and enhanced lipid peroxidation in bovine arterial endothelial cells (BAEC). We investigated the effects of Se deficiency on the expression of the selenoproteins in BAEC. 75Se metabolic labeling analysis and RT-PCR analysis revealed that BAEC expressed two glutathione peroxidase (GPx) isozymes, cytosolic GPx (cGPx) and phospholipid hydroperoxide GPx (PHGPx), three thioredoxin reductase (TrxR) isozymes, TrxR1, TrxR2 and TrxR3, and selenoprotein P (SelP). Se deficiency reduced both enzyme activity and mRNA level of cGPx, but did not affect those of PHGPx. SelP mRNA level was also reduced by Se deficiency, although the extent of reduction was much smaller than that of cGPx mRNA. We further found that TrxR activity was also decreased by Se deficiency but none of the mRNA levels of TrxR isozymes were reduced. These results indicate that vascular endothelial cells express several selenoproteins including cGPx, PHGPx, TrxR isozymes and SelP which might play important roles in the defense system against oxidative stresses and that the expressions of these selenoproteins are differently regulated by Se status.

In previous studies, magnetic resonance imaging (MRI) using contrast agents was found to be useful in distinguishing reperfused infarcts from nonreperfused infarcts. However, there have been only a few detailed studies using consecutive MR images for the assessment of myocardial reperfusion during an acute myocardial infarction and also no studies have been performed using a percutaneous transluminal coronary occlusion model (closed chest model). We induced acute myocardial infarction in dogs by occluding and then reperfusing the coronary artery with a balloon catheter. ECG-gated MR images were taken using the spin-echo technique before and after Gd-DTPA injection during both coronary artery occlusion and after reperfusion. We defined the intensity ratio (IR) as the signal intensity at the ischemic area divided by that at the nonischemic area on MR images and compared each image by the IR. Without Gd-DTPA, there was no difference between infarcted and normally perfused myocardium. Infarcted myocardium had a low signal intensity (IR = 0.68 +/- 0.14) soon after Gd-DTPA injection. This difference diminished with time. After reperfusion the infarcted myocardium had a high signal intensity (IR:1.76 +/- 0.34). We conclude that Gd-DTPA- enhanced MRI can distinguish reperfused from nonreperfused infarcts soon after Gd-DTPA administration.

Aqueous solutions of Syndiotactic-rich poly(vinyl alcohol) (PVA) form thermally reversible gels. The volume of the solution decreases with gelling time on standing at isothermal condition. Assuming that the gelation is due to the crystallization of PVA, the kinetics of isothermal crystallization from 5 wt.-% aqueous solutions of PVAs having 64,3 mol-% syndiotactic diads was investigated as a function of temperature (45–90°C), using dilatometry. The maximum in the overall rate of crystallization appeared at 60°C, regardless of the degree of polymerization of PVA. Since the values of n in the Avrami equation vary from about 1 to 2, it was apparent that the crystallization from aqueous solution of the polymer proceeded in the fashion of one-dimensional growth and heterogeneous, diffusion controlled nucleation. The phase diagram revealed that the syneresis of the gel was caused by the crystalline phase separation which supports the gelation accompanying crystallization. Wasrige Losungen von Polyvinylalkohol (PVA) mit einem erhohten Gehalt an syndiotaktischen Sequenzen (64,3 Mol-% syndiotaktische Diaden) bilden thermoreversible Gele. Wahrend der isothermen Gelierung nimmt das Volumen der Losung mit der Zeit ab. Unter der Annahme, das die Gelierung mit einer Kristallisation der PVA-Molekule verbunden ist, wird die Kinetik der isothermen Kristallisation von 5 Gew.-% wasrigen PVA-Losungen dilatometrisch als Funktion der Temperature (45–90°C) untersucht und nach Avrami ausgewertet. Dabei durchlauft die Kristallisationsgeschwindigkeit unabhangig vom Polymerisationsgrad des verwendeten PVA bei 60°C ein Maximum. Aus den Werten des Exponenten n in der Avrami Gleichung, die zwischen 1 und 2 liegen, folgt, das im System PVA-Wasser die Kristallisation auf einem eindimensionalen Kristallwachstum, sowie einer heterogenen, diffusionskontrollierten Keimbildung beruht. Das Phasendiagramm zeigt, das die bei Gelen auftretende Synarese durch Ausbildung einer kristallinen Phase verursacht wird, die die Gelierung wahrend der Kristallisation weiter verstarkt.