Evaluation of cerebral blood flow reserve in patients with cerebrovascular disease by SPECT using technetium-99m-L, L-ethyl cysteinate dimer

A technique for measuring the resting and acetazolamide (Acz)-activated cerebral blood flow without blood sampling by consecutive single-photon emission computed tomography (SPECT) using technetium-99m-L, L-ethyl cysteinate dimer (99mTc-ECD), called the 99mTc-ECD-RVR method, was recently developed by Matsuda et al . and Takeuchi et al . We evaluated the cerebral blood flow reserve in 77 patients with cerebrovascular diseases and 24 controls using this method. Baseline mean CBF (mCBF)was calculated from the application of Patlak plot graphical analysis with radionuclide angiography, and quantitative regional CBF (rCBF) images were obtained from qualitative axial SPECT images by the mCBF and Lassen’s linearization correction. The activated SPECT images were obtained by subtraction of the first image from the second image. The mean increment ratio (IR) by calculating the mean CBF for the pre- and post-Acz in the controls was 1.26±0.12 (mean±SD). In patients with cerebrovascular disease, the reduction of the mean IR and regional IR was parallel with the degree of stenosis. This noninvasive method was also considered to be useful in evaluating the change in the hemodynamic reserve in cerebrovascular disease

ノウソッチュウ シンダン ノ サイゼンセン

Stroke Care Unit （SCU） in Tokushima University Hospital has been opened since November １９９９. Patients with acute stroke in SCU were diagnosed by stroke MRI and biomarker immediately after their admission. Diffusion MRI could diagnose the ultra-acute ischemic and hemorrhagic lesion except brainstem ischemic lesion within ３ hrs after onset. Diffusion-Perfusion mismatch was useful to indicate intra-arterial thrombolytic therapy. ３T-MRI was introduced since March ２００４，and it can measured functional MR spectroscopy and tractography more quickly compared to １．５T-MRI. Plasma oxidized LDL in patients with acute cerebral infarction was significantly higher than that in healthy control and it became peak level during ３‐５ day after stroke onset. In conclusion, stroke MRI and plasma oxidized LDL are useful diagnostic tools for acute stroke

Pharmacokinetics and pharmacodynamics of insulin aspart in patients with Type 2 diabetes: Assessment using a meal tolerance test under clinical conditions

Few studies have evaluated the pharmacokinetics of rapid-acting insulin analogues in patients with Type 2 diabetes, especially under clinical conditions. The aim of the present study was to assess both the pharmacokinetics and pharmacodynamics of insulin aspart in Type 2 diabetic patients who were being treated with the analogue alone. Meal tolerance tests with and without self-injection of a customary dose of insulin aspart (0.05-0.22 U/kg) were conducted in 20 patients in a randomized cross-over study. The dose of insulin aspart (per bodyweight) was significantly correlated with both the maximum concentration (r 2 = 0.59; P < 0.01) and area under the concentration-time curve for insulin aspart (r 2 = 0.53; P < 0.01). However, the time to maximum concentration (T max), which varied widely from < 60 to ≥ 120 min, was not associated with either dosage (r 2 = 0.02; P = 0.51) or body mass index (r 2 = 0.02; P = 0.57). Injection of insulin aspart exacerbated delayed hyperinsulinaemia after meal loading, mainly in patients with T max ≥ 120 min. With regard to pharmacodynamics, insulin aspart had favourable effects on postprandial hyperglycaemia, hyperglucagonaemia and hyperlipidaemia. The T max for this insulin analogue differed greatly between individuals and delayed hyperinsulinaemia was particularly exacerbated in patients with higher T max values. Identification of the factors contributing to interindividual variation in the absorption lag time is essential for improving the efficacy and safety of insulin aspart. © 2012 The Authors. Clinical and Experimental Pharmacology and Physiology © 2012 Blackwell Publishing Asia Pty Ltd

Tranilast, an antifibrogenic agent, ameliorates a dietary rat model of nonalcoholic steatohepatitis

金沢大学医薬保健研究域医学系Nonalcoholic steatohepatitis (NASH) is the progressive form of nonalcoholic fatty liver disease and is one of the most common liver diseases in the developed world. The histological findings of NASH are characterized by hepatic steatosis, inflammation, and fibrosis. However, an optimal treatment for NASH has not been established. Tranilast, N-(3′,4′-dimedioxycinnamoyl)- anthranilic acid, is an antifibrogenic agent that inhibits the action of transforming growth factor beta (TGF-β). This drug is used clinically for fibrogenesis-associated skin disorders including hypertrophic scars and scleroderma. TGF-β plays a central role in the development of hepatic fibrosis, and tranilast may thus ameliorate the pathogenesis of NASH. We investigated the effects of tranilast using an established dietary animal model of NASH, obese diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats and nondiabetic control Long-Evans Tokushima Otsuka (LETO) rats fed a methionine-deficient and choline-deficient diet. Treatment with 2% tranilast (420 mg/kg/day) for 8 weeks prevented the development of hepatic fibrosis and the activation of stellate cells, and down-regulated the expression of genes for TGF-β and TGF-β-target molecules, including α1 procollagen and plasminogen activator-1. In addition, tranilast attenuated hepatic inflammation and Kupffer cell recruitment, and down-regulated the expression of tumor necrosis factor alpha. Unexpectedly, tranilast ameliorated hepatic steatosis and up-regulated the expression of genes involved in beta-oxidation, such as peroxisome proliferator-activated receptor α and carnitine O-palmitoyltransferase-1. Most of these effects were observed in LETO rats and OLETF rats, which suggest that the action of tranilast is mediated through the insulin resistance-independent pathway. Conclusion: Our findings suggest that targeting TGF-β with tranilast represents a new mode of therapy for NASH. Copyright © 2008 by the American Association for the Study of Liver Diseases

Olmesartan ameliorates a dietary rat model of non-alcoholic steatohepatitis through its pleiotropic effects

金沢大学大学院医学系研究科金沢大学医薬保健研究域医学系Insulin resistance is a major pathological condition associated with obesity and metabolic syndrome. Insulin resistance and the renin-angiotensin system are intimately linked. We evaluated the role of the renin-angiotensin system in the pathogenesis of insulin resistance-associated, non-alcoholic steatohepatitis by using the angiotensin II type 1 receptor blocker olmesartan medoxomil in a diabetic rat model. The effects of olmesartan on methionine- and choline-deficient (MCD) diet-induced steatohepatitis were investigated in obese, diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats and control Long-Evans Tokushima Otsuka (LETO) rats. Components of the renin-angiotensin system were up-regulated in the livers of OLETF rats, compared with LETO rats. In OLETF, but not LETO, rats, oral administration of olmesartan for 8 weeks ameliorated insulin resistance. Moreover, olmesartan suppressed MCD diet-induced hepatic steatosis and the hepatic expression of lipogenic genes (sterol regulatory element-binding protein-1c and fatty acid synthase) in OLETF, but not LETO, rats. In both OLETF and LETO rats, olmesartan inhibited hepatic oxidative stress (4-hydroxy-2-nonenal-modified protein) and expression of NADPH oxidase. Olmesartan also inhibited hepatic fibrosis, stellate cell activation, and expression of fibrogenic genes (transforming growth factor-β, α1 [I] procollagen, plasminogen activator inhibitor-1) in both OLETF and LETO rats. In conclusion, pharmacological blockade of the angiotensin II type 1 receptor slows the development of steatohepatitis in the OLETF rat model. This angiotensin II type 1 receptor blocker may exert insulin resistance-associated effects against hepatic steatosis and inflammation as well as direct effects against the generation of reactive oxygen species and fibrogenesis. © 2008 Elsevier B.V. All rights reserved

Metformin Prevents and Reverses Inflammation in a Non-Diabetic Mouse Model of Nonalcoholic Steatohepatitis

Background: Optimal treatment for nonalcoholic steatohepatitis (NASH) has not yet been established, particularly for individuals without diabetes. We examined the effects of metformin, commonly used to treat patients with type 2 diabetes, on liver pathology in a non-diabetic NASH mouse model. Methodology/Principal Findings: Eight-week-old C57BL/6 mice were fed a methionine- and choline-deficient plus high fat (MCD+HF) diet with or without 0.1% metformin for 8 weeks. Co-administration of metformin significantly decreased fasting plasma glucose levels, but did not affect glucose tolerance or peripheral insulin sensitivity. Metformin ameliorated MCD+HF diet-induced hepatic steatosis, inflammation, and fibrosis. Furthermore, metformin significantly reversed hepatic steatosis and inflammation when administered after the development of experimental NASH. Conclusions/Significance: These histological changes were accompanied by reduced hepatic triglyceride content, suppressed hepatic stellate cell activation, and the downregulation of genes involved in fatty acid metabolism, inflammation, and fibrogenesis. Metformin prevented and reversed steatosis and inflammation of NASH in an experimental non-diabetic model without affecting peripheral insulin resistance. © 2012 Kita et al