Mitral regurgitation secondary to spontaneous papillary muscle rupture: Report of a case

We report herein the unusual case of a 74-year-old man with acute heart failure in whom mitral regurgitation occurring secondary to papillary muscle rupture was found by echocardiography. There was no electrocardiographic evidence of myocardial infarction and a mitral valve replacement was successfully performed. Histologically the posteromedial muscle showed perivascular fibrosis without necrosis. The patient had an uneventful recovery and postoperative coronary angiography showed normal vasculature. This is a rare case of spontaneous papillary muscle rupture occurring secondary to chronic ischemia.     

Hepatic Fas protein expression might be a predictive factor for hepatocellular carcinoma development in patients with chronic hepatitis C undergoing interferon therapy

BACKGROUND: Several studies have revealed that interferon treatment may reduce the incidence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C virus (HCV). However, even after eradication of HCV, patients remain at risk for developing HCC. STUDY: Of 153 consecutive HCV patients who were treated with interferon and followed up for 5 years, 17 (11.1%) developed HCC. To elucidate predictive factors of HCC development, multivariate analysis was done for the 153 patients, and Fas protein expression in the biopsied specimens of liver before interferon treatment was examined in 17 patients who developed HCC and 17 patients who did not. RESULTS: Among the independent factors (sex, age, HCV genotype, HCV-RNA level, effect of interferon therapy, serum alanine aminotransferase before interferon therapy, and histologic stage and grade) tested by Cox proportional-hazards analysis, histologic stage (hepatic fibrosis) before interferon was significantly associated with HCC development (p = 0.01). In addition, the intensity of Fas protein expression was significantly greater in the liver specimens of the patients who developed HCC than in those who did not (p = 0.015). CONCLUSION: Histologic stage (hepatic fibrosis) and Fas protein expression before interferon treatment might be indicative of the need for intensive follow-up in patients with chronic hepatitis C undergoing interferon therapy.     

Biochemical and morphological effects of bladder pumping on the urinary bladder in rats

AIMS: To study the influence of bladder pumping on the urinary bladder in 44 female rats. METHODS: Under halothane anesthesia, a urethral catheter was inserted into the bladder of 27 rats, and air (0.4-0.8 mL) was pumped in and out of the bladder at 0.5 cycles/second for a period of 5 minutes. Twenty-four hours after pumping, the bladder was harvested for measurement of the tissue levels of myosin, actin, and nerve growth factor, as well as for electron microscopy. In nine of the 27 rats, cystometry was performed without anesthesia before and 1, 7, 30, and 90 days after bladder pumping. The remaining 17 rats that did not undergo pumping were anesthetized and their bladders were harvested as a control. RESULTS: Bladder pumping increased the bladder capacity and decreased the maximum bladder contraction pressure, but did not increase the residual volume. Bladder pumping also increased the tissue level of nerve growth factor and decreased the levels of myosin and actin. Electron microscopy showed degeneration of bladder smooth muscle cells and nerve fibers after bladder pumping, as well as derangement and disruption of collagen fiber bundles in the bladder wall. These functional and morphological effects of pumping disappeared within 90 days. CONCLUSIONS: Bladder pumping therapy appears to have various effects on the bladder wall collagen fiber bundles, smooth muscle cells, and nerves.     

Lysophosphatidic acid induces focal adhesion assembly through Rho/Rho-associated kinase pathway in human ovarian cancer cells

OBJECTIVE: The level of lysophosphatidic acid (LPA) is elevated in patients with ovarian cancer, and LPA has been reported to have a pivotal role in cancer dissemination. In the current study, the effect of LPA on the motility of ovarian cancer cells was investigated. METHODS: We analyzed the effects of LPA on the migration activity, the focal adhesion formation, and the tyrosine phosphorylation of focal adhesion proteins in human ovarian cancer cell lines Caov-3 and OVCAR-3. Inhibitors of the small GTPase Rho, one of its downstream effectors (Rho-associated kinase (ROCK)), myosin light chain kinase (MLCK), and myosin light chain (MLC) phosphatase were used to examine the mechanism of LPA-induced cellular effects. RESULTS: LPA enhanced the migration of ovarian cancer cells and facilitated their invasion. Rho and ROCK played essential roles in the migratory process, as evidenced by the inhibition of migration and focal adhesion formation of cancer cells by Clostridium botulinum C3 exoenzyme (C3), an inhibitor of Rho, or Y-27632, an inhibitor of ROCK. LPA also evoked the formation of focal adhesions and tyrosine phosphorylation of focal adhesion kinase and paxillin, all of which were inhibited by C3 or Y-27632. CONCLUSION: These results suggest that LPA induced the migration of ovarian cancer cells, at least in part, through accelerated formation of focal adhesions mediated by Rho/ROCK-induced actomyosin contractility. This study may provide the basis for new therapies to control the metastasis of ovarian cancer.