Assessment of efficiency and safety of adenovirus mediated gene transfer into normal and damaged murine livers

BACKGROUND: When recombinant adenoviruses are infused directly into the circulation, transgene expression is almost completely restricted to the liver. AIMS: Efficiency and safety of adenovirus mediated gene transfer into damaged livers were examined in mice with liver cirrhosis or fulminant hepatitis. METHODS: Liver cirrhosis and fulminant hepatitis were induced by intraperitoneal administration of thioacetamide and D-galactosamine followed by lipopolysaccharide, respectively. Mice were infused with adenoviruses carrying the Escherichia coli beta-galactosidase gene, lacZ gene, into the tail vein. Transduction efficiency of the lacZ gene was estimated histochemically by X-gal staining and quantitatively using a chemiluminescent assay. Activation of adenovirus specific T cells and development of neutralising antibodies against adenovirus were also examined. RESULTS: Histochemical evaluation revealed that approximately 40%, 80%, and 40% of cells in normal, cirrhotic, and fulminant hepatitis livers, respectively, were stained blue using X-gal staining. Quantitative analyses revealed that levels of lacZ expression in cirrhotic livers were approximately 2.5-fold and sixfold greater than those in normal and fulminant hepatitis livers, respectively. Although transgene expression in fulminant hepatitis livers was significantly lower than that in normal livers, marked levels of transgene expression were achieved even in fulminant hepatitis livers. Significant adverse effects of adenoviruses were not observed in damaged livers. There were no significant differences in cellular or humoral immune responses to adenoviruses among animals with normal, cirrhotic, and fulminant hepatitis livers. CONCLUSIONS: Our results suggest that gene therapy with adenoviruses may be used efficiently and safely, even in patients with severe liver disease.     

Difference in Left Ventricular Mass Index Between Hypertensive Patients With and Without Renal Artery Stenosis by Propensity Score Analysis

This study aimed to define the difference in cardiac hypertrophy between hypertensive patients with and without renal artery stenosis (RAS). When cardiac ultrasonographic examination was performed in 971 consecutive hypertensive outpatients, renal peak systolic velocity (PSV) was examined. Compared with patients without RAS, those with RAS (PSV ≥180 cm/s, 4.1%) were significantly older and included a higher proportion of male patients and had a higher left ventricular mass index (LVMI). A stratified analysis in the selected 120 patients showed that the LVMI was significantly higher in patients with RAS than in those without RAS for each confounding factor such as age and blood pressure. RAS was independently associated with a higher LVMI on propensity score analysis and multivariate analysis. Thus, the difference in LVMI between hypertensive patients with and without RAS was confirmed, irrespective of age and blood pressure, by stratified propensity score analysis and multivariate regression analysis.     

Hydrogen embrittlement of Ni-Ti superelastic alloy in fluoride solution

Hydrogen embrittlement of Ni-Ti superelastic alloy in a fluoride solution (0.2% APF) has been investigated by means of a tensile test (after immersion) and hydrogen thermal desorption analysis. Upon immersion, the tensile strength of the alloy decreased to the critical stress level of martensite transformation. Hydrogen desorption of the immersed specimens appeared with a peak at around 500 degrees C. The amount of absorbed hydrogen in the alloy ranged from 100 to 1000 mass ppm when immersed in the fluoride solution for 2 to 24 h. The immersion in the fluoride solution led to the degradation of mechanical properties due to hydrogen embrittlement. The results of the present study imply that one reason that Ti and its alloys fracture in the oral cavity is the fact that hydrogen is absorbed in a fluoride solution, such as prophylactic agents.     

Hand-assisted laparoscopic splenectomy for a huge splenic cyst: operative technique and case report

We report the case of a huge splenic cyst that was successfully treated by hand-assisted laparoscopic splenectomy. A 17-year-old girl with a chief complaint of left-sided abdominal pain was admitted to our department for investigation of a splenic tumor. Ultrasonography, computed tomography, and magnetic resonance imaging revealed a huge cystic lesion in the spleen measuring approximately 10 cm in diameter. Hand-assisted laparoscopic splenectomy was safely performed to diagnose and treat the splenic tumor. The histologic diagnosis was an epithelial cyst of the spleen with no atypical cells in the cyst wall. Hand-assisted laparoscopic splenectomy may be a good method of managing a huge splenic cyst that becomes symptomatic and potentially life-threatening through enlargement, rupture, and secondary infection.     

AT1 receptor blockade reduces cardiac calcineurin activity in hypertensive rats

The possible role of calcineurin in the attenuation of cardiac hypertrophy and fibrosis by blockade of the angiotensin II type 1 (AT1) receptor was investigated in Dahl salt-sensitive (DS) rats. The effect of the calcineurin inhibitor FK506 was also studied. DS rats progressively developed severe hypertension when fed a diet containing 8% NaCl from 7 weeks of age. In addition, marked cardiac hypertrophy and fibrosis were apparent and the activity of calcineurin and its mRNA expression in the myocardium was increased in these animals at 12 weeks in comparison with age-matched Dahl salt-resistant rats. The abundance of angiotensin-converting enzyme (ACE) and transforming growth factor (TGF)-beta1 mRNAs was also increased in the hearts of DS rats at 12 weeks. Treatment of DS rats with a non-antihypertensive dose of the selective AT1 receptor blocker candesartan (1 mg/kg per day) or FK506 (0.1 mg/kg per day) from 7 to 12 weeks attenuated both calcineurin activity and its mRNA expression in the heart, as well as the development of cardiac hypertrophy and fibrosis, without affecting cardiac function. Treatment with candesartan, but not FK506, prevented the upregulation of ACE and TGF-beta1 gene expression. Both candesartan and FK506 prevented the load-induced induction of fetal-type cardiac genes. These results demonstrate that AT1 receptor blockade attenuates the development of cardiac hypertrophy and fibrosis as well as the activation of calcineurin, without an antihypertensive effect, in rats with salt-sensitive hypertension. Calcineurin may be downstream from TGF-beta1 in AT1 receptor-mediated angiotensin II signaling in vivo.     

Halting the interaction between vascular endothelial growth factor and its receptors attenuates liver carcinogenesis in mice

It has been shown that angiogenesis plays an important role not only in tumor growth, but also in early carcinogenesis. The expression of a potent angiogenic factor, vascular endothelial growth factor (VEGF), increased during the early stage of carcinogenesis. In this study, the effects of the neutralizing monoclonal antibodies R1 mAb and R2 mAb of the VEGF receptors Flt-1 (VEGFR-1) and KDR/Flk-1 (VEGFR-2), respectively, on murine hepatocarcinogenesis induced by diethylnitrosamine (DEN) were examined. The effects of R1 mAb and R2 mAb on spontaneous lung metastasis from hepatocellular carcinoma (HCC) were also investigated. VEGF expression and neovascularization in the tumor increased stepwise during hepatocarcinogenesis. Treatment with both R1 mAb and R2 mAb markedly inhibited the development of HCC and adenoma in the liver. The inhibitory effect of R2 mAb was more potent than that of R1 mAb, and the combination treatment with both mAbs almost completely attenuated hepatocarcinogenesis. Both R1 mAb and R2 mAb treatment significantly suppressed the development of angiogenesis in HCC. The suppressive effects against angiogenesis R1 mAb and R2 mAb were similar in magnitude to their inhibitory effects against hepatocarcinogenesis. Furthermore, spontaneous lung metastasis from HCC was also significantly suppressed by R1 mAb and R2 mAb treatment. In conclusion, these results suggest that VEGF and receptor interaction plays an important role in hepatocarcinogenesis and in spontaneous lung metastasis from HCC.     

Different Roles of 8-Hydroxyguanine Formation and 2-Thiobarbituric Acid-reacting Substance Generation in the Early Phase of Liver Carcinogenesis Induced by a Choline-deficient, l-Amino Acid-defined Diet in Rats

The present study was performed to assess the roles of hepatocellular oxidative damage to DNA and constituents other than DNA in rat liver carcinogenesis caused by a choline-deficient, l -amino acid-defined (CDAA) diet by examining the effects of the antioxidant N, N' -diphenyl- p -phenylenediamine (DPPD). The parameters used for cellular oxidative damage were the level of 8-hydroxyguanine (8-OHGua) for DNA and that of 2-thiobarbituric acid-reacting substance (TBARS) for constituents other than DNA. A total of 40 male Fischer 344 rats, 6 weeks old, were fed the CDAA diet for 12 weeks with or without DPPD (0.05, 0.10 or 0.20%) or butylated hydroxytoluene (BHT, 0.25%). In the livers of the rats, the numbers and sizes of glutathione S -transferasc (EC 2.5.1.18) placental form (GSTP)- and/or γ-glutamyltransferase (GGT, EC 2.3.2.2)-positive lesions and levels of 8-OHGua and TBARS were determined. The GSTP-positive lesions of 0.08 mm² or larger were all stained positively for GGT as well in cross-sectional area, whereas the smaller lesions were generally negative for GGT. DPPD and BHT reduced the size of the GSTP-positive lesions without affecting their total numbers. At the same time, they reduced TBARS generation without affecting 8-OHGua formation in DNA. The present results indicate that oxidative DNA damage (represented by 8-OHGua formation) and damage to constituents other than DNA (represented by TBARS generation) may play different roles in rat liver carcinogenesis caused by the CDAA diet; the former appears to be involved in the induction of phenotypically altered hepatocyte populations while the latter may be related to the growth of such populations.     

Safe and efficient transgene expression in rat hepatocytes induced by adenoviral administration into the biliary tract

We examined whether retrograde intrabiliary adenoviral administration could induce safe and efficient transgene expression in hepatocytes. We administered recombinant adenovirus carrying a reporter lacZ gene retrogradely into the common bile duct of rats and evaluated the transduction efficiency of the lacZ gene in the liver histochemically by X-gal staining, and also quantitatively by a chemiluminescent reporter gene assay. Retrograde administration of adenovirus into the common bile duct was shown to successfully induce transgene expression in the liver. Although transgene expression induced by intrabiliary adenoviral administration was observed predominantly at periportal areas, a considerable number of cells expressing the transgene were detectable even in lobular and centrilobular areas. Furthermore, histochemical analysis revealed that intrabiliary adenoviral administration resulted in gene transfer into hepatocytes, but not into biliary epithelial cells. Transgene expression in the liver was transient, and pathological and biochemical analyses revealed that hepatic damage caused by intrabiliary adenoviral administration was not substantial. The results demonstrated in the present study suggest that retrograde administration of adenovirus into the common bile duct can induce safe and efficient transgene expression in hepatocytes without causing considerable adverse effects, supporting the feasibility of adenovirus-mediated gene transfer into hepatocytes in clinical settings by means of endoscopic retrograde cholangiography.