Hepatitis C virus JFH-1 strain infection in chimpanzees is associated with low pathogenicity and emergence of an adaptive mutation

The identification of the hepatitis C virus (HCV) strain JFH-1 enabled the successful development of infectious cell culture systems. Although this strain replicates efficiently and produces infectious virus in cell culture, the replication capacity and pathogenesis in vivo are still undefined. To assess the in vivo phenotype of the JFH-1 virus, cell culture-generated JFH-1 virus (JFH-1cc) and patient serum from which JFH-1 was isolated were inoculated into chimpanzees. Both animals became HCV RNA-positive 3 days after inoculation but showed low-level viremia and no evidence of hepatitis. HCV viremia persisted 8 and 34 weeks in JFH-1cc and patient serum-infected chimpanzees, respectively. Immunological analysis revealed that HCV-specific immune responses were similarly induced in both animals. Sequencing of HCV at various times of infection indicated more substitutions in the patient serum-inoculated chimpanzee, and the higher level of sequence variations seemed to be associated with a prolonged infection in this animal. A common mutation G838R in the NS2 region emerged early in both chimpanzees. This mutation enhances viral assembly, leading to an increase in viral production in transfected or infected cells. CONCLUSION: Our study shows that the HCV JFH-1 strain causes attenuated infection and low pathogenicity in chimpanzees and is capable of adapting in vivo with a unique mutation conferring an enhanced replicative phenotype.     

Atrial blood cyst with ischemic heart disease.

A 52-year-old male with coronary artery disease had the extremely rare occurrence of a blood cyst in the right atrium. Surgical removal with coronary artery bypass grafting was performed successfully.     

Defective expression of prohormone convertase 4 and enhanced expression of insulin-like growth factor II by pleural solitary fibrous tumor causing hypoglycemia

A 75-year-old man was admitted to our hospital because of unconsciousness. His plasma glucose was very low, but his serum levels of insulin and IGF-I were also low. He was found to have a giant solitary pleural tumor, which was completely resected, after which his hypoglycemia ameliorated postoperatively. Histologically, the tumor was consistent with the pathological diagnosis of a solitary fibrous tumor derived from the pleura. Immunohistochemical study revealed positive immunostaining for IGF-II in tumor cells. The presence of high molecular weight (HMW) form of IGF-II in the tumor tissue and patient's serum was confirmed by Western blot analysis. Steady-state mRNA levels of IGF-II and prohormone convertases (PC) 4, a potential protease responsible for IGF-II processing, as determined by RT-PCR were about 14-fold greater and 5-fold less in the tumor tissue than those in normal placental tissue, respectively. Therefore, it is suggested that biologically active, unprocessed HMW form of IGF-II generated from the impaired processing of IGF-II precursor by the defective PC4 expression in the tumor was responsible for the non-islet cell tumor hypoglycemia (NICTH) in the present case.     

Study of the echocardiographic diagnosis of acute pulmonary thromboembolism and risk factors for venous thromboembolism

OBJECTIVES: To identify the relationship of risk factors for atherosclerosis with venous thromboembolism (VTE) and the utility of transthoracic echocardiography in acute pulmonary thromboembolism (APTE). METHODS: In 75 patients with VTE (VTE group), 101 patients with suspected VTE (N group), and 50 control subjects (control group), the frequency of atherosclerosis risk factors such as hyperlipidemia, obesity, hypertension, smoking, and diabetes mellitus and the number of risk factors were evaluated. Transthoracic echocardiographic findings such as tricuspid regurgitation, right ventricular dilation, pulmonary hypertension, and right ventricular dysfunction were evaluated in 15 patients with APTE (APTE group) and 38 patients in the N group (NC group). RESULTS: The incidence of hyperlipidemia in the VTE group was statistically higher than that in the control group (odds ratio 2.16, 95% confidence interval 1.43-3.08). Additionally, the incidence of obesity was higher in the VTE and N groups than in the control group (odds ratio was 2.76, 95% confidence interval 1.67-4.37). Risk factors other than obesity and hyperlipidemia and the number of risk factors were not significant. The incidence of tricuspid regurgitation, right ventricular dilation, and pulmonary hypertension in APTE was statistically greater than that in NC group. Right ventricular dilation and right ventricular dilation + tricuspid regurgitation are reliable findings in echocardiography. However, even combining with tricuspid regurgitation, right ventricular dilation is insufficient to identify or screen patients with APTE. CONCLUSIONS: Hyperlipidemia and obesity may be risk factors for VTE. However, obese patients can manifest similar findings to VTE. Although transthoracic echocardiograpghy is not recommended as a diagnostic or screening test in APTE, it should be used as an ancillary test.     

Late-night salivary cortisol as a screening test for the diagnosis of Cushing's syndrome in Japan

Measurement of late-night and/or midnight salivary cortisol currently used in US and European countries is a simple and convenient screening test for the initial diagnosis of Cushing's syndrome (CS). Unfortunately, this test has not been widely used in Japan. The purpose of this study was to evaluate the usefulness of the measurement of late-night salivary cortisol as a screening test for the diagnosis of CS in Japan. We studied 27 patients with various causes of CS, consisting of ACTH-dependent Cushing's disease [5] and ectopic ACTH syndrome [4] and ACTH-independent adrenal CS [11] and subclinical CS [7]. Eleven patients with type 2 diabetes and obesity and 16 normal subjects served as control group. Saliva samples were collected at late-night (23:00) in a commercially available device and assayed for cortisol by radioimmunoassay. There were highly significant correlations (P<0.0001) between late-night serum and salivary cortisol levels in normal subjects (r = 0.861) and in patients with CS (r = 0.788). Late-night salivary cortisol levels in CS patients (0.975 +/- 1.56 microg/dl) were significantly higher than those in normal subjects (0.124 +/- 0.031 microg/dl) and in obese diabetic patients (0.146 +/- 0.043 microg/dl), respectively. Twenty-five out of 27 CS patients had late-night salivary cortisol concentrations greater than 0.21 microg/dl, whereas those in control group were less than 0.2 microg/dl. Receiver operating characteristic curve (ROC) analysis showed that the cut-off point of 0.21 microg/dl provides a sensitivity of 93% and a specificity of 100%. Therefore, it is concluded that the measurement of late-night salivary cortisol is an easy and reliable noninvasive screening test for the initial diagnosis of CS, especially useful for large high-risk populations, such as diabetes and obesity.     

Cardio-ankle vascular index (CAVI) as a novel indicator of arterial stiffness: theory, evidence and perspectives

The cardio-ankle vascular index (CAVI) is a new index of the overall stiffness of the artery from the origin of the aorta to the ankle. The most conspicuous feature of CAVI is its independence of blood pressure at the time of measurement.CAVI increases with age and in many arteriosclerotic diseases, such as coronary artery disease, carotid arteriosclerosis, chronic kidney disease and cerebrovascular disease, and is related to many coronary risk factors, such as hypertension, diabetes mellitus, dyslipidemia and smoking. Furthermore, CAVI decreases by controlling diabetes mellitus and hypertension, and also by abstaining from smoking. This suggests that CAVI is a physiological surrogate marker of athero- or arteriosclerosis, and also might be an indicator of lifestyle modification.Recently, it has been reported that CAVI and several left ventricular functions are co-related, suggesting a connection between the heart muscle and vascular function.This review covers the principles of CAVI and our current knowledge about CAVI, focusing on its roles and future outlook.     

Preoperative dialysis for liver transplantation in methylmalonic acidemia

Dialysis immediately before liver transplantation for patients with methylmalonic academia (MMA) with the mut0 mutation is considered to be necessary to reduce plasma methylmalonic acid (MMA) levels and prevent metabolic decompensation for a successful surgical outcome; however, this has not yet been conclusively confirmed. Ten pediatric patients underwent living donor liver transplantation at the National Center for Child Health and Development, Tokyo, Japan. Seven patients received dialysis immediately before surgery, but the three most recent patients did not receive dialysis. We monitored plasma MMA levels and evaluated metabolic status during the perioperative period. Plasma MMA levels of patients who received preoperative dialysis were significantly decreased. However, lactic acidosis developed in two patients during surgery. One of the patients who had decreased renal function suffered from severe lactic acidosis after the transplantation and died on post operative day 44. In the three patients who did not receive preoperative dialysis, high plasma MMA levels persisted, but they did not develop metabolic decompensation. Their plasma MMA levels gradually decreased after transplantation. Our results indicated that reducing MMA with preoperative dialysis does not decrease the risk of metabolic decompensation. We will need to evaluate whether preoperative dialysis is necessary for the success of surgery with more cases in the future. Adequate perioperative glucose infusion and careful lactate monitoring are pivotal for success.     

Influence of hepatitis B virus genotypes on the intra- and extracellular expression of viral DNA and antigens

Various genotypes of the hepatitis B virus (HBV) induce liver disease of distinct severity, but the underlying virological differences are not well defined. Huh7 cells were transfected with plasmids carrying 1.24-fold the HBV genome of different genotypes/subgenotypes (2 strains each for Aa/A1, Ae/A2, Ba/B2 and D; 3 each for Bj/B1 and C). HBV DNA levels in cell lysates, determined by Southern hybridization, were the highest for C followed by Bj/Ba and D/Ae (P < .01), and the lowest for Aa (P < .01), whereas in culture media, they were the highest for Bj, distantly followed by Ba/C/D and further by Ae/Aa (P < .01). The intracellular expression of core protein was more than 3-fold lower for Ae/Aa than the others. Hepatitis B e antigen (HBeAg) was excreted in a trend similar to that of HBV DNA with smaller differences. Secretion of hepatitis B surface antigen (HBsAg) was most abundant for Ae followed by Aa, Ba, Bj/C and remotely by D, which was consistent with mRNA levels. Cellular stress determined by the reporter assay for Grp78 promoter was higher for C and Ba than the other genotypes/subgenotypes (P < .01). Severe combined immunodeficiency mice transgenic for urokinase-type plasminogen activator (uPA/SCID), with the liver replaced for human hepatocytes, were inoculated with virions passed in mouse and recovered from culture supernatants. HBV DNA levels in their sera were higher for C than Ae by 2 logs during 4-7 weeks after inoculation. In conclusion, virological differences among HBV genotypes were demonstrated both in vitro and in vivo. These differences may influence HBV infections with distinct genotypes in clinical and epidemiological settings.