Unloading-mediated muscle atrophy is associated with increased reactive oxygen species (ROS) production. We previously demonstrated that elevated ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b) resulted in the loss of muscle volume (Nakao R, Hirasaka K, Goto J, Ishidoh K, Yamada C, Ohno A, Okumura Y, Nonaka I, Yasutomo K, Baldwin KM, Kominami E, Higashibata A, Nagano K, Tanaka K, Yasui N, Mills EM, Takeda S, Nikawa T. Mol Cell Biol 29: 4798–4811, 2009). However, the pathological role of ROS production associated with unloading-mediated muscle atrophy still remains unknown. Here, we showed that the ROS-mediated signal transduction caused by microgravity or its simulation contributes to Cbl-b expression. In L6 myotubes, the assessment of redox status revealed that oxidized glutathione was increased under microgravity conditions, and simulated microgravity caused a burst of ROS, implicating ROS as a critical upstream mediator linking to downstream atrophic signaling. ROS generation activated the ERK1/2 early-growth response protein (Egr)1/2-Cbl-b signaling pathway, an established contributing pathway to muscle volume loss. Interestingly, antioxidant treatments such as N-acetylcysteine and TEMPOL, but not catalase, blocked the clinorotation-mediated activation of ERK1/2. The increased ROS induced transcriptional activity of Egr1 and/or Egr2 to stimulate Cbl-b expression through the ERK1/2 pathway in L6 myoblasts, since treatment with Egr1/2 siRNA and an ERK1/2 inhibitor significantly suppressed clinorotation-induced Cbl-b and Egr expression, respectively. Promoter and gel mobility shift assays revealed that Cbl-b was upregulated via an Egr consensus oxidative responsive element at −110 to −60 bp of the Cbl-b promoter. Together, this indicates that under microgravity conditions, elevated ROS may be a crucial mechanotransducer in skeletal muscle cells, regulating muscle mass through Cbl-b expression activated by the ERK-Egr signaling pathway.
We report herein on the follow-up of ten consecutive patients who underwent perineal rectosigmoidectomy, and discuss the indications, surgical technique, and outcomes of this procedure. The median age of the patients was 79 years, with a range of 26 to 85 years, and eight patients had complicating medical conditions. Of five patients who underwent this procedure for a recurrent prolapse after another type of perineal procedure, four had previously undergone the Thiersch operation combined with the Gant-Miwa technique. The mean length of the excised rectum and sigmoid colon was 22.1 cm. Pain was minimal or absent in all patients and oral intake was commenced after 2 days. There were no mortalities, but anastomotic leakage occurred in one patient. The mean follow-up period was 3.5 years. Only one patient developed recurrent rectal prolapse 24 months after the operation. Of seven patients who underwent concomitant levatoroplasty for incontinence, five became fully continent within 3 weeks after the operation, while the remaining two improved after 2 months. We propose that perineal rectosigmoidectomy is indicated for patients who have suffered an early recurrence of prolapse after another transperineal repair; elderly or high-risk patients with incontinence; male patients; and patients with an incarcerated or gangrenous prolapsed rectal segment.
We carried out a prospective clinical trial of colon preparation with a regimen of oral antibiotics starting on the day before surgery. The patients were assigned to one of two groups consisting of either a mechanical preparation alone group (group 1, 45 cases) or a mechanical bowel preparation with oral antibiotics group (group 2, 38 cases). Group 2 received kanamycin and metronidazole three times on the day before surgery. Cefmetazole was administered for 3 consecutive days as prophylaxis in both groups. In a study using intraoperative mucosal swabs, the rates of group 2 patients with cultures yielding anaerobes or Gram-negative bacteria were significantly lower than those of group 1. There were no significant differences in the rates of patients with cultures yielding fungi or Gram-positive organisms. The positive culture rate in the peritoneal fluid of group 1 was also higher than that of group 2 (40%, 16%, P < 0.05). The surgical site infection rate was 18% in group 1 and 13% in group 2. Organisms isolated from the sites of postoperative infections were not identical with those from the peritoneal fluid. This relatively brief course preparation minimized the emergence of resistant strains. However, in spite of the colonic bacterial burden and the intraoperative inoculation in the patients with mechanical cleansing alone, their incidence of subsequent infections was comparable to that of patients who were administered oral antibiotics provided that the prophylactic antibiotic was administered for 3 days after surgery.
We report a case of diffuse large B-cell lymphoma (DLBCL) in the ampulla of Vater, causing painless obstructive jaundice in a 78-year-old woman. Duodenal endoscopy revealed a mass in the ampulla of Vater and narrowing of the second portion of the duodenum, although diagnosing DLBCL from an endoscopic biopsy was impossible because there were several kinds of leukocytes in the infiltrate. We performed pylorus-preserving pancreatoduodenectomy to establish a histological diagnosis, relieve the obstructive jaundice, and remove the narrowed second portion of the duodenum. Histological and immunohistochemical examination of the surgically resected specimen confirmed a diagnosis of DLBCL. Chemotherapy is the mainstay of treatment for DLBCL; however, surgery still plays an important role when the histological diagnosis cannot be established preoperatively and when complications are not amenable to nonsurgical therapy.
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