Evolution of hierarchy and irreversibility in theoretical cell differentiation model.

The process of cell differentiation in multicellular organisms is characterized by hierarchy and irreversibility in many cases. However, the conditions and selection pressures that give rise to these characteristics remain poorly understood. By using a mathematical model, here we show that the network of differentiation potency (differentiation diagram) becomes necessarily hierarchical and irreversible by increasing the number of terminally differentiated states under certain conditions. The mechanisms generating these characteristics are clarified using geometry in the cell state space. The results demonstrate that the hierarchical organization and irreversibility can manifest independently of direct selection pressures associated with these characteristics, instead they appear to evolve as byproducts of selective forces favoring a diversity of differentiated cell types. The study also provides a new perspective on the structure of gene regulatory networks that produce hierarchical and irreversible differentiation diagrams. These results indicate some constraints on cell differentiation, which are expected to provide a starting point for theoretical discussion of the implicit limits and directions of evolution in multicellular organisms.

Effect of early postoperative feeding on the healing of colonic anastomoses in the presence of intra-abdominal sepsis in rats.

PURPOSE: Intra-abdominal infection is generally considered a major risk factor for dehiscence of primary colon anastomosis. To elucidate the indications for nutritional support during intra-abdominal sepsis, we investigated the healing of anastomoses in an animal model. METHODS: Twenty male Sprague-Dawley rats (280-320 g) underwent cecal ligation and single puncture. After 24 hours the perforated cecum was removed, and the left colon was transected and anastomosed in a single-layer inverted fashion. Animals were randomly assigned to receive both chow and water (early-fed group; n = 10) or water alone for the first 72 hours and chow thereafter (late-fed group; n = 10). Colon-bursting pressure was measured five days after the anastomosis, at which time the anastomosis was excised. RESULTS: The survival rate after cecal ligation and single puncture was 100 percent, and blood cultures were positive in 20 percent of animals five days after surgery. All data are expressed as means +/- standard error of the mean. Body weight increased more in the early-fed group than in the late-fed group (15.6+/-3 vs. -6.3+/-2.8 g; P < 0.001). Early feeding resulted in increased anastomotic bursting pressure (200+/-11 vs. 161+/-12 mmHg; P < 0.05) and total collagen concentration at the site of anastomosis (2.36+/-0.09 vs. 2.01+/-0.07 microg/mg wet tissue; P < 0.01) compared with the late-fed group. CONCLUSION: Early feeding has a positive effect on anastomotic healing in the presence of intraabdominal sepsis. The mechanism by which early feeding enhances the colonic anastomotic healing is unclear, although preservation of colonic collagen seems to play a significant role.

[Effects of intravenous and oral administration of ondansetron hydrochloride on chemotherapy-induced nausea and vomiting in patients with esophageal cancer].

The effects of ondansetron hydrochloride (OND) were studied through 11 courses of chemotherapy, including 70 mg/m2 of cisplatin, in 9 patients with advanced esophageal cancer. During the observation period of 5 days, 4 mg of OND was given intravenously on the day of cisplatin infusion and orally for consecutive 4 days, and nausea was controlled by over 70%. Vomiting was controlled by over 80%. The inhibitory effect of OND on nausea and vomiting was found in 72.7% on the day of cisplatin injection and 88.9% overall. No other side effects of OND except slight increases in total bilirubin and LDH were found in any patient. These findings suggest that intravenous and oral administration of OND may inhibit chemotherapy-induced nausea and vomiting in patients with advanced esophageal cancer.

Thoracoscopic excision with mini-thoracotomy for a bronchogenic cyst of the esophagus.

A 19 year-old man with a history of dysphagia and chest pain was diagnosed as having a cyst of the esophagus by endoscopic ultrasonography and magnetic resonance imaging. The patient's bronchogenic cyst was treated by video-assisted thoracoscopic excision with mini-thoracotomy. This procedure is applicable for patients who require repair of the esophageal wall after excision of a lesion and reduces post-operative complications.

Spontaneous gastrointestinal perforation in patients with lymphoma receiving chemotherapy and steroids. Report of three cases.

Spontaneous gastrointestinal perforations in three patients with lymphoma were considered to be treatment-related conditions. All three were diagnosed as having malignant lymphoma by histological examination, and treated with chemotherapy and steroids. Four to 14 days after the start of chemotherapy, they complained of abdominal pain and plain roentgenograms revealed pneumoperitoneum. The interval between the onset of peritonitis and operation was almost 24 h. Emergency operations were carried out; one patient with a jejunal perforation underwent resection of the jejunum, another with a gastric perforation received a simple closure with omental patch, and the third with a gastric perforation underwent gastrectomy. Two patients recovered from the surgery, while the gastrectomy patient died due to sepsis. The favorable outcome of the surgical intervention is attributed to early diagnosis, prompt exploration, and selective operative procedures. We recommended a simple closure with omental patch for gastroduodenal perforation. Resection and primary anastomosis are possible only in the small bowel.

[Evaluation of peritoneal lavage smears and intraperitoneal administration of anti-neoplastic agents in stage III and IV gastric cancer].

Examinations of peritoneal lavage smears (cy) in gastric cancer surgical stages III and IV are very important for determining the disease stage. We have been carrying out these examinations for 8 years. One hundred sixty patients with gastric cancer were examined. The incidence of cy positivity was higher in T4 than in T3, and higher in P1,2,3 than in P0. We performed intraperitoneal administration of CDDP in 10 patients with gastric cancer using a reservoir (Infuse-A-Port) implanted in the abdominal wall once a week. No difference in survival was observed between patients who received chemotherapy via i.p. and those who received it i.v.

End-stage renal failure due to crescentic glomerulonephritis in a patient with Behçet's syndrome. Review of the literature.

We report a rare case of a patient with Behçet's syndrome who developed end-stage renal failure due to crescentic glomerulonephritis (GN). A 20-year-old male patient had suffered from uveitis, aphthous mouth ulcers and genital ulceration for the past 7 years. His renal function rapidly deteriorated and renal biopsy specimens obtained when his serum creatinine level was 3 mg/dl showed diffuse proliferative GN with fibrous crescent formation in 75% of glomeruli excluding totally sclerotic glomeruli. Immune complexes were identified by demonstration of complement and immunoglobulins in the glomeruli. He developed end-stage renal failure during a 1-year course and received maintenance hemodialysis. We reviewed the literature on severe forms of GN in patients with Behçet's syndrome.

[Successful treatment of hepatic metastasis of gastric cancer with 5'-DFUR and Lentinan].

Satisfactory therapeutic effects are rarely obtained with oral chemotherapy for gastric cancer. We have experienced successful treatment for synchronous hepatic metastasis of gastric cancer with 5'-DFUR and Lentinan. The patient was a 78-year-old female, diagnosed as having gastric cancer with multiple hepatic metastases, who underwent gastrectomy. Immunohistochemistry of the resected specimens with anti-thymidine phosphorylase (dThdPase) antibody yielded positive results for dThdPase in the primary tumor as well as the hepatic metastases. Two months after surgery, administration of 400 mg of 5'-DFUR per day and 2 mg i.v. of Lentinan every other week was started. Four months after discharge, carcinoembryonic antigen (CEA) in plasma showed an abrupt logarithmic decline. Furthermore, a 99% reduction in hepatic metastases was demonstrated by abdominal CT. At present, 22 months after surgery, the patient is managed on an outpatient basis with no complaints of any side effects. Immunochemotherapy using 5'-DFUR and Lentinan may be effective against gastric malignancies expressing dThdPase activity.