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Tadashi Matsumura

Publications and source records attributed to Tadashi Matsumura.

7 recordsLinked to original sources

Short-term effects of atorvastatin on bone turnover in male patients with hypercholesterolemia.

No consensus has been reached on whether the 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, known as statins, have beneficial effects on bone health. The purpose of our study was to evaluate the effects of atorvastatin on bone metabolism by means of measuring bone turnover markers in male patients with hypercholesterolemia both at diagnosis and prospectively after 3 months of treatment. Twenty-two Japanese male patients (mean age 62.36 +/- 10.1 years) with untreated hypercholesterolaemeia were selected for this study. After 3-months treatment of atorvastatin, total cholesterol and low density lipoprotein cholesterol significantly decreased as expected (p<0.001 for both parameters). Bone-specific alkaline phosphatase (BAP) did not change significantly (p = 0.444). However, serum N-terminal telopeptide of type I collagen (NTx) significantly decreased by -19.86 +/- 26.4% (p = 0.020). In addition, delta NTx during the course of this study was negatively correlated with NTx at baseline (r = -0.645, p = 0.0008). Although there was a tendency of positive correlations of delta NTx with delta total cholesterol, delta triglycerides, and delta low density lipoprotein cholesterol, and of negative correlations of delta NTx and delta BAP with delta high density lipoprotein cholesterol, none of them reached statistical significance. Our findings suggest that atorvastatin may have potentially beneficial effects on bone metabolism in patients with hypercholesterolemia mostly by reducing bone resorption rather than by stimulating bone formation. Further studies with more patients and longer duration are warranted to evaluate its effects, if any, on prevention of osteoporosis and subsequent fractures.

Aged↗

Additional effect of low iron diet on iron reduction therapy by phlebotomy for chronic hepatitis C.

BACKGROUND/AIMS: Iron-induced oxidative stress plays an important role in the pathogenesis of chronic hepatitis C. Both phlebotomy for removing body iron stores and low iron diet for minimizing portal iron supply to the liver have been shown to improve serum transaminase levels in patients with the disease. However, the cooperative effects of phlebotomy and low iron diet have not yet been elucidated in detail. METHODOLOGY: A pilot study was undertaken to investigate whether a low iron diet could improve the efficacy of phlebotomy in iron reduction therapy. Of 21 patients diagnosed with chronic hepatitis C, 10 patients were treated with phlebotomy alone (group A) while 11 patients were treated with a low iron plus phlebotomy (group B). Phlebotomy was repeated biweekly until serum ferritin levels reached 10 ng/mL in both A and B groups. In addition, a low iron diet (iron intake of 8 mg/day or less) was recommended for group B, followed by estimation of iron intake from daily diet records. RESULTS: Serum alanine aminotransferase levels were significantly improved from 106+/-30 to 68+/-22 IU/L (p<0.005, paired t-test) in group A and from 100+/-33 to 46+/-10 IU/L (p<0.002, paired t-test) in group B. The enzyme levels after treatment were significantly higher in group A (p<0.02, non-paired t-test), which showed a higher upward distribution of the enzyme activity. The estimated dietary iron intake in group B was reduced from 17.6+/-6.1 to 8.2+/-3.7 mg/day. CONCLUSIONS: These findings suggest that phlebotomy alone does not completely remove iron-induced oxidative stress and a low iron diet induces an additional effect in iron reduction therapy for chronic hepatitis C.

Adult↗

Determinants of cisplatin and irinotecan activities in human lung adenocarcinoma cells: evidence of cisplatin accumulation and topoisomerase I activity.

To elucidate the sensitivity of adenocarcinoma of the lung to cisplatin and irinotecan, intracellular glutathione (GSH) and glutathione S-transferase (GST)-pi concentrations and topoisomerase (topo) I activity were investigated using six adenocarcinoma cell lines. The antiproliferative activity was determined by MTT assay in terms of inhibition concentration (IC50) values. The IC50 values to cisplatin were not correlated with the amounts of intracellular GSH or GST-pi, but with intracellular accumulation of platinum (r = -0.91, p = 0.013). IC50 values to SN-38 were correlated with topo I activity determined by relaxation assay of pBR322 (r = -0.83, p = 0.040). These results suggest that platinum accumulation and topo I activity have definite impacts on the sensitivity of lung adenocarcinoma to cisplatin and irinotecan, respectively.

Adenocarcinoma↗