[Diffuse Malignant Peritoneal Mesothelioma with Secondary Liver Invasion Diagnosed Using Laparoscopy - A Case Report].

A 69-year-old man with right upper quadrant abdominal pain and fever was referred to our hospital. He had a history of asbestosis exposure. Computed tomography(CT)revealed a mass at the right subhepatic space, and an antibiotic was administered after a diagnosis of an abdominal abscess. However, the patient did not respond to the treatment, and finally, exploratory laparoscopy was performed. A sheet of combined white nodules surrounding the right lobe of the liver was found, and the mass was continuous with the covering particles. Biopsy of the mass and immunohistochemical examination was performed. The resulting diagnosis was diffuse epithelial malignant peritoneal mesothelioma(MPM). Postoperative systematic chemotherapy of pemetrexed and cisplatin was administered. Laparoscopy was useful to evaluate the distribution of the MPM, which led to adequate therapeutic determination.

Activation of the Cpx phosphorelay signal transduction system in acidic phospholipid-deficient pgsA mutant cells of Escherichia coli.

The pgsA gene encodes the enzyme for the committed step in the synthesis of acidic phospholipids in Escherichia coli, and the pssA gene does the same for zwitterionic phospholipid. It has been reported that the Rcs and Cpx phosphorelay signal transduction systems are activated in pgsA- and pssA-defective mutants, respectively. In this study, we show that the Cpx system is activated also in a pgsA mutant, whereas the Rcs system was not activated in a pssA mutant. Lack of phosphatidylglycerol in pgsA mutants causes inadequate modification of lipoproteins, resulting in poor localization to the outer membrane. The outer membrane lipoprotein RcsF is necessary for the response of the Rcs system to various stimuli, and Rcs activation in pgsA mutants involves inner membrane mislocalization of this lipoprotein. The outer membrane lipoprotein NlpE, however, while necessary for the surface adhesion-induced Cpx response, was not involved in Cpx activation in the pgsA mutant.

Accumulation of sigmaS due to enhanced synthesis and decreased degradation in acidic phospholipid-deficient Escherichia coli cells.

The Escherichia coli pgsA3 mutation, which causes deficiency in acidic phospholipids, leads to a significant accumulation of sigma(S). This accumulation is partly accounted for by the higher transcription level of rpoS; however, it has also been suggested that the cells accumulate sigma(S) post-transcriptionally. We found that the level of the small regulatory RNA RprA, which is involved in the promotion of rpoS translation, is higher in pgsA3 cells than in pgsA(+) cells. Induction of altered rpoS mRNA that does not depend on RprA in pgsA(+) cells did not increase the level of sigma(S) to the high level observed in pgsA3 cells, suggesting post-translational sigma(S) accumulation in the latter. The mRNA levels of clpX and clpP, whose products form a ClpXP protease that degrades sigma(S), were much reduced in pgsA3 cells. Consistent with the reduced mRNA levels, the half-life of sigma(S) in pgsA3 cells was much longer than in pgsA(+) cells, indicating that downregulation of the degradation is a major cause for the high sigma(S) content. We show that the downregulation can be partially attributed to activated CpxAR in the mutant cells, which causes repression of rpoE on whose gene product the expression of clpPX depends.