Liver stiffness measurement using acoustic radiation force impulse elastography in hepatitis C virus-infected patients with a sustained virological response.

BACKGROUND: Acoustic radiation force impulse (ARFI) elastography is a non-invasive method for measuring liver stiffness. However, there are no reports evaluating the value of ARFI elastography for liver fibrosis in chronic hepatitis C patients with a sustained virological response (SVR). AIM: To investigate the diagnostic performance of ARFI elastography for the assessment of liver fibrosis in hepatitis C virus (HCV) infected patients with an SVR. METHODS: In this prospective study, we enrolled 336 patients: 121 HCV patients with an SVR (44.6% women) and 215 patients with HCV (47.9% women). ARFI elastography measurements of all patients were performed on the same day of liver biopsy. RESULTS: The diagnostic accuracies, expressed as areas under the receiver operating characteristic curves for ARFI elastography, in HCV patients with an SVR and those in patients with HCV were 0.818 and 0.875 for the diagnosis of significant fibrosis (≥F2), 0.909 and 0.888 for the diagnosis of severe fibrosis (≥F3), and 0.981 and 0.890 for the diagnosis of liver cirrhosis (F4), respectively. The optimum cut-off values for ARFI elastography were 1.26 m/s for ≥F2, 1.31 m/s for ≥F3 and 1.49 m/s for F4 in HCV patients with an SVR. The liver stiffness values were lower in patients with SVR compared with those in patients with HCV at the same stage of fibrosis. The liver stiffness values were affected by the necroinflammatory activity and the time after SVR. CONCLUSION: Acoustic radiation force impulse elastography is an acceptable method for predicting the severity of fibrosis in patients with hepatitis C virus and a sustained viral response.

Paraoxonase polymorphism (Gln192-Arg) is associated with coronary heart disease in Japanese noninsulin-dependent diabetes mellitus.

Serum paraoxonase/arylesterase (PONA) is associated with high-density lipoprotein and may prevent oxidation of low-density lipoprotein by hydrolyzing lipid peroxides. A recent report suggested an association of glutamine (A type)/arginine (B type) polymorphism at position 192 of PONA gene with coronary heart disease (CHD) among Caucasian patients with noninsulin-dependent diabetes mellitus (NIDDM). However, conflicting results have also been reported. To investigate the significance of this polymorphism in the pathogenesis of CHD, we performed an association study of this polymorphism with CHD in Japanese NIDDM patients. We genotyped 164 patients with NIDDM, 42 with CHD, and 122 without CHD. Other known risk factors for CHD were matched between the 2 groups. AB+BB isoforms were detected in 41 of 42 diabetic patients with CHD. The proportion of B allele carriers (AB+BB) was significantly higher than that of AA carriers among diabetic patients with CHD compared with those without CHD (chi 2 = 7.68, P = 0.003). Multivariate logistic regression analyses showed a markedly increased odds ratio (OR: 8.823, CI, 1.13-68.7) in B allele carriers, while ORs of other risk factors remained between 1.01 and 1.92. Carriers of the B allele of the Gln192Arg polymorphism in the PONA gene proved to be at increased risk for developing CHD in Japanese NIDDM patients. This association was independent of other known risk factors for CHD, suggesting an important role of the paraoxonase B isoform in the pathogenesis of CHD.

High concentration of glucose causes impairment of the function of the glutathione redox cycle in human vascular smooth muscle cells.

We demonstrated that high glucose reduced H2O2 scavenge activity in human vascular smooth muscle cells. In the cells exposed to high glucose, the intracellular glutathione content decreased, although the NADPH content was unchanged. The rate of uptake of cystine, which is a rate-limiting precursor of the glutathione synthesis, decreased in the high glucose group compared with the control group. These decreases were shown to be dependent on glucose concentration. It was suggested that high glucose causes impairment of the function of the glutathione redox cycle in human vascular smooth muscle cells, resulting in reduced H2O2 scavenge activity.

Effect of vitamin E on the degradation of hydrogen peroxide in cultured human umbilical vein endothelial cells.

Vitamin E reacts with radicals such as lipid peroxyl radical (LOO*) and singlet oxygen ((1)O2), and plays a role in inhibiting lipid peroxidation in cell membranes and preventing the oxidation of low-density lipoproteins (LDL). However, only a few studies have investigated the effect of vitamin E on the degradation of hydrogen peroxide (H2O2). Therefore, we examined the effect of vitamin E on glutathione redox cycle-dependent H2O2 degradation activity in human umbilical vein endothelial cells (HUVEC). Confluent HUVEC were cultured for seven days in media containing various concentrations of vitamin E (alpha-tocopherol). The level of glutathione redox cycle-dependent H2O2 degradation activity and the intracellular glutathione level were determined. HUVEC that had been cultured in the presence of higher concentrations of vitamin E had a higher level of H2O2 degradation activity and a higher intracellular content of the reduced form of glutathione (GSH). Therefore, it is suggested that the vitamin E-induced increase in H2O2 degradation activity in HUVEC results from an increase in intracellular GSH level.

Hyperglycemia in diabetic rats reduces the glutathione content in the aortic tissue.

The glutathione redox cycle plays a major role in scavenging hydrogen peroxide (H2O2) under physiological conditions. Recently, we demonstrated that a high glucose concentration in the culture medium reduced the level of H2O2 scavenging activity of human vascular smooth muscle cells (hVSMCs). We also showed that a high glucose concentration reduced the intracellular glutathione (GSH) content and the rate of uptake of cystine, which itself is a rate-limiting factor that maintains the GSH level (FEBS Lett.421: 19-22,1998). In the present study, we investigated whether the hyperglycemic condition in diabetic rats impairs the glutathione content in the aortic tissue in vivo. Wistar rats were divided into the following three groups: streptozotocin-induced diabetic rats (STZ-D, n=7), insulin-treated STZ-D rats (I-STZ-D, n=8), and non-diabetic controls (C, n=7). Fourteen days after streptozotocin injection, the aortic tissue was extracted and the GSH content in the aortic tissue was measured. Furthermore, the relationship between the GSH content in the aortic tissue and blood glucose level in Otsuka Long-Evans Tokushima Fatty (OLETF) rats aged 30 weeks, which developed diabetes spontaneously, was investigated. The GSH content in the aortic tissue of the STZ-D group (0.99+/-0.14 nmol/mg protein) was significantly lower than that of the control group (1.68+/-0.15 nmol/mg protein). Insulin treatment to the diabetic rats restored the GSH content in the aortic tissue (I-STZ-D group; 1.45+/-0.11 nmol/mg protein). Among the 22 Wistar rats, the GSH content in the aortic tissue was negatively correlated with the blood glucose level (r=-0.69, p<0.01, n=22). Among the OLETF rats, a similar negative correlation between the GSH content in the aortic tissue and blood glucose level was seen (r=-0.64, p<0.05, n=10). We demonstrated in vivo that the hyperglycemic condition in STZ-induced diabetic Wistar rats and OLETF rats reduced the GSH content in aortic tissue. This suggested reduced glutathione redox cycle function of aorta.

Restoration of nitric oxide production by aldose reductase inhibitor in human endothelial cells cultured in high-glucose medium.

The effects of elevated glucose and aldose reductase inhibitor (ARI:ONO-2235) on nitric oxide (NO) production in cultured human umbilical endothelial cells (HUVEC) were evaluated. Aldose reductase and nitric oxide synthase(NOS) share NADPH as an obligate cofactor, therefore it is suggested that the enhanced of glucose flux (27.5 mM) by aldose reductase inhibited NO production by blunting NOS activity. However, the addition of ONO-2235 (100 microM) prevented the inhibition of [NO2-] production. Since ARI decreases glucose-mediated inhibition of NO production in HUVEC. this agent might ameliorate endothelial function associated with diabetes.

Increased production of PDGF by angiotensin and high glucose in human vascular endothelium.

The mechanisms responsible for the abnormalities in the vascular wall associated with long standing diabetes mellitus are incompletely understood. The aim of this investigation was to assess the effects of angiotensin II and high glucose on the production of platelet-derived growth factor (PDGF) in human endothelial cells. For this purpose, a primary culture was obtained from fresh human umbilical cords by collagenase digestion of the vein interior. A high glucose medium increased the production of PDGF and a similar effect was observed by the addition of mannitol. These data are consistent with a stimulatory effect of glucose on PDGF that is mediated by the osmotic effect of this substance. Angiotensin II significantly increased PDGF in human endothelial cells and the effect was accompanied by a transient increase in cytosolic calcium. The angiotensin II-induced intracellular Ca2+ increases, PDGF production were completely abolished by saralasin and neomycin, respectively. We postulate that the increased production of PDGF by the vascular endothelium in response to high glucose and angiotensin II may participate in the development of the diabetic angiopathy.

Heme-Cu complexes as oxygen-activating functional models for the active site of cytochrome c oxidase.

Tri(2-pyridylmethyl)amineCu complex-linked iron meso-tetraphenylporphyine derivatives were prepared to model the active site of cytochrome c oxidase. Exposure to oxygen converted the reduced forms of the complexes to the corresponding stable mu-peroxo species in spite of the presence of three coordination sites, two on the heme and one on the Cu. The oxy forms were characterized spectroscopically. Kinetic analyses of the oxygenation reactions of the reduced forms suggests that preferential O2 binding occurs at the Cu site over the heme. This mechanism is also supported by examination of the redox potentials of the two metal ions. Since the peroxy complexes of the models exhibit a structure similar to that of the previously reported fully-oxidized form, the relevance of the model chemistry to the enzyme reaction is discussed.

Comparison of 5-fluorouracil and 5-fluoro-2'-deoxyuridine as an effector in radiation-activated prodrugs.

The purpose of this study was to clarify whether 5-fluoro-2'-deoxyuridine (FdUrd) is superior to 5-fluorouracil (5-FU) as an effector in the radiation-activated prodrugs which we have been developing. The in vitro cytotoxicity of 5-FU and FdUrd was compared in two murine tumor and four human pancreatic cancer cell lines using a colony assay and in vivo efficacy was compared with SCCVII tumor using a growth delay time assay. FdUrd was slightly more hydrophilic than 5-FU. In vitro, FdUrd was more efficient than 5-FU in two lines, whereas 5-FU was more efficient in two lines and the two drugs were almost equal in efficacy in the remaining two. The concentration to reduce tumor cell survival to 50% after 24-h drug exposure was 5-32 microM for both 5-FU and FdUrd in murine lines, while it was 30-210 microM in human pancreatic cancer cell lines. The difference in relative efficacy of the two drugs among these cell lines could not be attributed to the rate of intracellular uptake of the compounds. FdUrd was less toxic than 5-FU in C3H/He mice, and FdUrd was less efficient than 5-FU in SCCVII tumors in vivo. These results suggest that FdUrd is not necessarily more potent than 5-FU, and development of the FdUrd prodrugs may not necessarily turn out to be fruitful.

Experimental and modeling studies on sorption and diffusion of radium in bentonite.

The sorption and desorption behavior of radium on bentonite and purified smectite was investigated as a function of pH, ionic strength and liquid to solid ratio by batch experiments. The distribution coefficients (Kd) were in the range of 10(2) to > 10(4) ml g-1 and depended on ionic strength and pH. Most of sorbed Ra was desorbed by 1 M KCl. The results for purified smectite indicated that Ra sorption is dominated by ion exchange at layer sites of smectite, and surface complexation at edge sites may increase Ra sorption at higher pH region. Reaction parameters between Ra and smectite were determined based on an interaction model between smectite and groundwater. The reaction parameters were then used to explain the results of bentonite by considering dissolution and precipitation of minerals and soluble impurities. The dependencies of experimental Kd values on pH, ionic strength and liquid to solid ratio were qualitatively explained by the model. The modeling result for bentonite indicated that sorption of Ra on bentonite is dominated by ion exchange with smectite. The observed pH dependency was caused by changes of Ca concentration arising from dissolution and precipitation of calcite. Diffusion behavior of Ra in bentonite was also investigated as a function of dry density and ionic strength. The apparent diffusion coefficients (Da) obtained in compacted bentonite were in the range of 1.1 x 10(-11) to 2.2 x 10(-12) m2 s-1 and decreased with increasing in dry density and ionic strength. The Kd values obtained by measured effective diffusion coefficient (De) and modeled De were consistent with those by the sorption model in a deviation within one order of magnitude.

[Fundamental and clinical studies of a sustained release preparation of cefaclor in the surgical field].

Fundamental and clinical studies of S6472 (sustained release preparation of cefaclor (CCL] were conducted in the surgical field and it was confirmed that the preparation is a useful drug. The following is the summary of the results from the fundamental and clinical studies: In vitro antibacterial activity. CCL showed MICs of 0.78 to 6.25 micrograms/ml against almost strains of S. aureus, E. coli and Klebsiella isolated from surgical wound regions, and the antibacterial activities were stronger than those of cephalexin (CEX). Clinical efficacy. S6472 was orally administered to 33 patients with skin and soft tissue infections in 2 divided doses. As a result, excellent clinical response was observed in 13 patients, good response observed in 14 patients, fair in 4 and poor in 1. The clinical efficacy in 1 of the 33 patients was unknown. Overall clinical effective rate was 84.4%. Adverse reaction. In 2 patients, mild gastrointestinal symptoms were observed.

[Clinical evaluation of S6472 (prolonged action preparation of cefaclor) in the treatment of skin and soft tissue infections. A double blind comparison of S6472 and cefaclor].

A double-blind comparative study of S6472 and cefaclor (CCL) was conducted to evaluate the therapeutic efficacy, safety and usefulness in the treatment of skin and soft tissue infections. Either 750 mg b.i.d. of S6472 or 750 mg t.i.d. of CCL was administered orally to patients for a period of 7 consecutive days. Of the 250 cases (123 cases of S6472 group and 127 cases of CCL group) recruited in this trial, 228 cases (114 cases of S6472 and 114 cases of CCL) were adopted by the committee members for the evaluation of therapeutic efficacy, 238 cases (118 cases of S6472 group and 120 cases of CCL group) for usefulness, and 245 cases (121 cases of S6472 group and 124 cases of CCL group) were adopted for the evaluation of side effects. The backgrounds of both patients group were almost similar. The results obtained were as follows: Overall clinical effectiveness Of the 114 patients treated with S6472, excellent clinical responses were obtained in 11 patients, good in 79, fair in 19, poor in 5 (efficacy rate 78.9%), and of the 114 patients treated with CCL, excellent were in 16, good in 78, fair in 13, poor in 7 (efficacy rate 82.5%). There was no statistically significant difference between the 2 groups. Clinical effectiveness classified by initial severity and bacteriological efficacy There was no significant difference between the 2 groups in the clinical effectiveness classified by initial severity and in the bacteriological efficacy. Side effects were noticed in 5 patients of 121 treated with S6472 (4.1%) and in 2 patients of 124 treated with CCL (1.6%), and other 13 patients developed some abnormal laboratory findings. But these undesirable reactions were mild, and developed no significant difference between the 2 groups in the incidence of side effects. There was no significant difference between the 2 groups in the usefulness of the drugs. Conclusively, 750 mg b.i.d. of S6472 is anticipative of the same clinical efficacy, safety and usefulness as compared with that of 750 mg t.i.d. of CCL in the treatment of skin and soft tissue infections.

[Surgical treatment of a long-term decubitus ulcer].

A 64-year-old male presented with a large decubitus ulcer of the sacrum which had not healed for thirteen years in spite of various conservative treatments. His primary disease was paraplegia following spondylitis. Although he was not ambulatory, he was able to manage a wheelchair. The decubitus, which had a 8 x 13 cm dead space, was successfully closed with a single operation using two fasciocutaneous flaps. The patient was discharged two months postoperatively. The medical cost of his treatment before and after the surgery was investigated. The expense including the surgery and postoperative care until discharge was five times more than the monthly cost of the preoperative period. These findings suggest that a decubitus ulcer which does not respond to conservative treatments for more than several months should be considered for a surgical management, as long as the patient's general condition permits an operation.