Changes in microstructure and gene expression of articular chondrocytes cultured in a tube under mechanical stress

OBJECTIVE: The objective of this study was to clarify the effects of mechanical stress on chondrocytes cultured in a tube. Centrifugal pressure was applied to chondrocytes cultured in a tube for 28 days, and the effect of this stress was evaluated using a molecular biological method. DESIGN: Articular cartilage was harvested from a rabbit. A cell suspension was then prepared, and transferred in 1 ml aliquots to polypropylene tubes. After 48 h of incubation, centrifugal pressure (6.9 MPa) was applied every 24 h. Changes in morphology, expression of messenger RNA (mRNA) for insulin-like growth factor-I (IGF-I) and type II collagen, cell number, wet weight and protein concentration were evaluated. RESULTS: Microscopically, formation of chondrocyte clusters was seen in the cultures subjected to stress. Ultrastructurally, collagen fibers were seen to run parallel to the cytoplasmic surface of the stressed chondrocytes. The peak of IGF-I mRNA expression was seen on day 5, whereas type II collagen mRNA expression peaked on day 14. Cell number, wet weight and protein concentration were significantly increased in the stressed cultures. CONCLUSIONS: These results suggest that mechanical stress might affect the arrangement of collagen fibers and the IGF-I activity of chondrocytes cultured in a tube, thus influencing chondrocyte proliferation and increasing the volume of the extracellular matrix. Furthermore, mechanical stress may also affect the metabolism of articular cartilage in vitro.     

Evaluation of prognostic significance in extracapsular spread of lymph node metastasis in patients with gastric cancer

BACKGROUND: Extracapsular spread of lymph node metastasis has been shown as a negative prognostic factor in cancers of several other organs. This study was performed to clarify the prognostic significance of extracapsular spread in patients receiving curative resection for gastric cancer. METHODS: Extracapsular spread was defined as infiltration of cancer cells beyond the capsule of the metastatic lymph node. Four hundred and two patients who underwent curative gastrectomy were evaluated. Eight potential prognostic factors, including the International Union Against Cancer (Union International Contra la Cancrum; [UICC]) N stage and nodal status classified by the presence of lymph node metastasis or extracapsular spread, were examined. RESULTS: Three survival curves grouped by nodal status differed significantly, and prognosis of patients with extracapsular spread was significantly worse than for the other groups. Both UICC N stage ( P < .001) and nodal status ( P < .001) were significant prognostic factors by multivariate analysis. UICC N stages were subcategorized by nodal status, and survival was shown to be significantly worse in patients with extracapsular spread in the UICC N1 group ( P = .04). CONCLUSIONS: Extracapsular spread was a significant negative prognostic indicator on multivariate analysis, and may be useful in combination with UICC N stage. Extracapsular spread was regarded as an important indicator to refine the nodal staging system in gastric cancer.     

4-oxo-2-hexenal, a mutagen formed by omega-3 fat peroxidation, causes DNA adduct formation in mouse organs

To identify mutagens formed in a model reaction of lipid peroxidation, linolenic acid methyl ester and hemin were reacted with dG. As a result, a 4-oxo-2-hexenal-dG adduct (dG*) was identified in the model reaction mixture. The 4-oxo-2-hexenal (4-OHE) showed mutagenic activity in the Salmonella typhimurium strains TA100 and TA104. After 4-OHE was orally administered to mice, dG, 4-OHE-dC- and 4-OHE-5-methyl-dC adducts were detected in esophageal, stomach and intestinal DNA. In the vapor phase released from the methyl linolenate-hemin model system, and in the smoke released during the broiling of fish, 4-OHE was detected by GCMS. The 4-OHE seems to be produced by the auto-oxidation of omega-3 polyunsaturated fatty acids. These results provide a warning to workers dealing with omega-3 fats, who may be exposed to this volatile mutagen.     

GABA Levels in Cerebrospinal Fluid of Patients with Epilepsy

Abstract: The lumbar cerebrospinal fluid (CSF) γ-aminobutyric acid (GABA) levels were measured in 27 patients with epilepsy, another three epileptic patients with status epilepticus and three epileptic patients with chronic cerebellar ataxia. The mean lumbar CSF GABA levels of the 27 patients with epilepsy were not significantly different from those of normal controls. Six of these 27 patients who had daily partial complex and partial motor seizures showed significantly low CSF GABA levels as did the six other patients, three each with status epilepticus and chronic cerebellar ataxia. These findings suggest that some epileptic patients have impaired brain GABAergic neurons.     

Hidroacanthoma simplex: a case report and analysis of 70 Japanese cases

Imatinib is a specific and potent inhibitor of the BCR-ABL tyrosine kinase. Several clinical trials have demonstrated the efficacy of imatinib in chronic myeloid leukemia. Adverse cutaneous reactions induced by imatinib are frequent and may be dose related. We report a case of an unusual pustular eruption in a patient with chronic myeloid leukemia, who received high doses imatinib for blast crisis and later voriconazole for invasive pulmonary aspergillosis. At the time of his skin eruption, elevated plasma levels of imatinib were recorded. Imatinib is primarily metabolized by the cytochrome CYP3A4. Voriconazole is a cytochrome CYP3A4 inhibitor and can lead to high plasma levels of imatinib. This case suggests that severe drug reactions to imatinib may be related not only to imatinib doses, but also to elevated plasma drug levels resulting from pharmacokinetic interactions. The monitoring of imatinib plasma levels may be of help for identifying patients at risk for severe toxicity.     

Biliary atresia with associated complicated anorectal and urogenital malformations

We report on a girl with biliary atresia (BA) who also suffered with anorectal agenesis without fistula and complicated urogenital malformation. The outcome of patients with these severe anomalies is poor, but she has survived without liver and/or renal transplantation for more than 3 years. A careful treatment plan for each anomaly in addition to prevention of cholangitis and urinary tract infection is indispensable for managing these complicated anomalies.     

Treatment of acute pancreatitis with protease inhibitor, H2 receptor antagonist and somatostatin analogue

Acute pancreatitis sometimes develops to severe condition with a variety of clinical manifestations and high mortality. Autodigestion of the pancreas, secondary to the activation of digestive enzymes, plays a major role in the pathogenetic mechanism of acute pancreatitis. To improve the mortality and complication rates, appropriate treatments based on the precise prediction of disease severity are required. To this end, the early administration of protease inhibitors has commonly been employed for the therapy of acute pancreatitis in Japan. However, a number of clinical trials have failed to show the clinical effects of protease inhibitors, H2 receptor antagonist and somatostatin analogue on the treatment of acute pancreatitis. To evidence the therapeutic value of these agents for acute pancreatitis, well-organized clinical studies will be required.     

Pancreatitis-associated gene mutations

Since the discovery of the cationic trypsinogen gene mutations in patients with hereditary pancreatitis, a variety of pancreatitis-associated gene mutations have been reported, including pancreatic secretory trypsin inhibitor and cystic fibrosis transmembrane conductance regulator. Although the patients with these mutations are rarely seen, genetic disorders inducing pancreatitis have provided us major breakthroughs to understand the molecular basis of the disease. Furthermore, the major stream in pancreatology has been evidenced in patients with hereditary pancreatitis: acute pancreatitis --> chronic pancreatitis --> pancreatic cancer. This report will focus on the pancreatitis-associated genes and the molecular mechanism of pancreatitis associating with these gene mutations.     

A hot water extract of Chlorella pyrenoidosa reduces body weight and serum lipids in ovariectomized rats

The effects of a hot water extract of Chlorella pyrenoidosa, which contains chlorella growth factor (CGF), on the body weight, serum lipids, and the bone mass were evaluated using an ovariectomized rat as a model for postmenopausal bone loss. Rats were divided into four groups: sham-operated (Sham), Sham given the CGF solution, ovariectomized (OVX), and OVX given the CGF solution, respectively. Administration of the extract to OVX rats suppressed the body weight gain. After 7 weeks, the administration of the extract to the OVX group reduced increases in both serum total cholesterols and high-density lipoprotein (HDL) cholesterols. It also normalized the decrease of triglyceride level in the OVX group. The ovariectomy decreased the tibial bone mineral density (BMD) by 19%, and the administration of the extract to OVX rats did not inhibit this decrease. These results suggest that a dietary supplement of CGF may be useful to control the body weight and improve lipid metabolism of menopausal women.