Extraskeletal Myxoid Chondrosarcoma of the Vulva: A Case Report.

Extraskeletal myxoid chondrosarcoma (EMC) of the vulva is extremely rare. We report our experience with a case of disease control by radiation therapy to a localized lesion of EMC. A 41-year-old woman presented to our clinic with a vulvar mass. Magnetic resonance imaging showed a 15 cm mass between the perineum and the medial thigh muscle. It was the "adductor magnus muscle." After the needle biopsy, a histopathological diagnosis of EMC was made. Tissue genomic analysis detected the EWSR1-NR4A3 fusion gene. A joint operation by the Department of Orthopedics, Gynecology, and Plastic Surgery was performed, which included a wide excision of the perineum, partial excision of the medial thigh muscle, and rectus abdominis valvuloplasty. Intraoperatively, pubic infiltration was detected. Postoperative pelvic radiotherapy was administered as adjuvant therapy. Recurrent common iliac lymph node metastases outside the irradiation field and multiple lung metastases were observed. Pazopanib was administered as adjuvant therapy. Pulmonary metastases were controlled, but the pelvic tumor had spread, so the patient underwent radiation therapy. After second-line chemotherapy with doxorubicin, left pleural effusion and mediastinal lymph node metastasis appeared, and third-line chemotherapy with eribulin mesylate was administered. The pleural effusion improved, but the patient developed cough again, and trabectedin was administered as the fourth chemotherapy. In this case, there was no local recurrence for three years after radiotherapy, suggesting the effectiveness of radiotherapy in local control.

Diagnosis of hepatic steatosis based on ultrasound attenuation imaging is not influenced by liver fibrosis.

AIM: Recently, a new technique using attenuation imaging (ATI) was developed to diagnose hepatic steatosis. The aim of this study was to investigate whether ATI for the evaluation of hepatic steatosis is influenced by liver fibrosis. METHODS: A total of 328 patients with chronic liver disease were enrolled to study the associations between histological hepatic steatosis or liver fibrosis and ATI findings. The interaction between liver fibrosis and ATI was also analyzed. RESULTS: Median ATI values according to steatosis grade and fibrosis stage increased in line with the progression of liver steatosis (p < 0.001) and fibrosis (p < 0.05). However, in each steatosis grade, ATI values according to fibrosis stage were not significantly increased. In multiple regression analyses for assessment of the effect of their interaction, the p values for fibrosis stage, steatosis grade, and fibrosis stage × steatosis grade were 0.096, <0.001, and 0.077, respectively. Variance inflation factor values for fibrosis stage, steatosis grade, and fibrosis stage × steatosis grade were 1.079, 1.094, and 1.074, respectively. CONCLUSION: Attenuation imaging values are not influenced by liver fibrosis.

Long-term survival following radiofrequency ablation of lung metastases in an elderly patient with calcaneal osteosarcoma: A case report and review of the literature.

RATIONALE: Recently, the number of osteosarcomas has been increasing in elderly patients due to human longevity. Lung metastases are the primary cause of death from osteosarcomas. Complete resection of lung metastases can prolong the survival. However, complete resection in elderly patients is often difficult due to high risk of operative complications. Computed tomography (CT) guided radiofrequency ablation (RFA) is a minimally invasive technique to destroy tumor nodules using heat. In this report, we present the first case older than 65 years applying RFA for lung metastases due to osteosarcoma. PATIENT CONCERNS: A 74-year-old male presented with 1-year history of heel pain. A conventional high-grade osteosarcoma in his calcaneus was diagnosed. Below-knee amputation was performed. However, lung metastases were found in both lungs 1 year after amputation. CT-guided lung RFA was chosen since surgical intervention for lung metastases was abandoned because of tumor multiplicity and medical comorbidities. A total of 18 lung metastases were treated by CT-guided RFA. The most frequent complication was pneumothoraxes in 4 of 8 (50%) procedures and chest tube drainage was required in 2 of these (2 of 8 (25%) procedures). DIAGNOSES: Six lung metastases of osteosaroma were found in both lungs at 1 year after surgery. INTERVENTIONS: CT-guided lung RFA was performed. A total of 18 lung metastases were treated in 8 lung RF procedures. OUTCOMES: The patient has been alive with disease for 5.5 years after the initial surgery. LESSONS: CT-guided lung RFA is effective for elderly patients with osteosarcoma lung metastases in spite of discouragement of lung metastasectomy due to multiplicity of metastases and medical-comorbidities.

Comparison of liver stiffness assessment by transient elastography and shear wave elastography using six ultrasound devices.

AIM: Transient elastography (TE) is the gold standard for measurement of liver stiffness. The usefulness of shear wave elastographies (SWE) is well accepted. However, the measurement values cannot be equivalently compared because cut-off values for the diagnosis of liver fibrosis are different among those devices. We aimed to clarify correlations, to generate the regression equations between TE and SWEs, and to compare the diagnostic ability of each device to diagnose liver fibrosis. METHODS: A total of 109 patients with chronic liver disease who underwent liver biopsy and same-day evaluation of liver stiffness using six ultrasound devices were analyzed. The diagnostic ability of liver stiffness from each ultrasound device and correlations between TE and each SWE were analyzed. RESULTS: Liver stiffness measured by all six ultrasound devices increased significantly as liver fibrosis stage advanced (P < 0.001). Receiver operating characteristic (ROC) curve analysis for predicting significant fibrosis (≥F2) and cirrhosis yielded area under the ROC curve (AUROC) values based on TE of 0.830 (95% confidence interval [CI], 0.755-0.905) and 0.959 (95% CI, 0.924-0.995), respectively. The AUROCs for predicting significant fibrosis (≥F2) and cirrhosis (F4) based on SWE from all five ultrasound devices were over 0.8 and 0.9, respectively. Furthermore, the correlation coefficients between TE values and SWE values from five ultrasound devices were all over 0.8, indicating a strong relationship. CONCLUSION: Our study showed strong correlations between TE and SWEs with high correlation coefficients. The regression equations between TE and SWEs demonstrated the ability to compare the measurement values in each device equivalently.

Congenital lipomatous tumour, presented as a polypoidal projection on upper eyelid.

A Japanese baby was born with a polypoidal projection with hair, on the lateral corner of upper eyelid. The tumour had extent to bulbar sub-conjunctival area. He presented no other malformation nor pathological symptoms. There was no sign of association with Goldenhar, hemifacial macrosomia, epidermal nevus or linear nevus sebaceous syndromes. The tumour was resected at his age of 4 months. The ocular conjunctiva was incised but not excised. Histopathologically, it was mainly consisted of multi-lobuled mature adipose tissue, dense fibrous tissue was observed at the centre of mass, assumed to be the link of palpebral tarsal plate to lateral canthal ligament. As for the location and component, the tumour was diagnosed as a lipomatous hamartoma. Detached tarsal plate was reattached to the lateral canthal ligament. Satisfactory result was achieved aesthetically and functionally. Congenital lipomatous hamartoma, with protuberant appendage appearance on eyelid, without syndromic association, is presented.

Clinicopathological characteristics of cancer associated with Crohn's disease.

PURPOSE: We examined the clinicopathological characteristics and prognosis of patients with cancer associated with Crohn's disease (CD). METHODS: The subjects of this study were patients with cancer confirmed in a resected specimen of bowel, who were treated at our institution between September, 1974 and December, 2014. RESULTS: We analyzed 34 patients (26 men, 8 women, median age at cancer diagnosis 43.5 years, duration of illness 18 years) and found that the number of those with CD complicated with cancer began to drastically increase after 2005. The site of onset of cancer was in an anorectal lesion in 24 (70.6 %) patients. In 17 (50 %) patients, the cancer was diagnosed before surgery; in 3 patients (8.8 %), it was based on pathological findings during surgery; and in 14 patients (41.2 %), it was based on postoperative pathological findings. Mucinous carcinoma was the dominant histological type, seen in 15 patients (44.1 %), while the special type of signet-ring cell carcinoma was found in 4 patients. The cumulative overall 5 year survival rate was 46.2 %. CONCLUSION: In this group of Japanese CD patients, an anorectal lesion was the most frequent site of origin of cancer. As cancer was diagnosed preoperatively in only 50 % of these patients, the overall prognosis was poor, with a cumulative 5 year survival rate of just 46.2 %.

Penile pseudomyogenic hemangioendothelioma/epithelioid sarcoma-like hemangioendothelioma with a novel pattern of SERPINE1-FOSB fusion detected by RT-PCR--report of a case.

We experienced a rare case of penile mesenchymal tumor in a 43-year-old Japanese man. At least three nodules were observed around the penis. The tumors were composed of spindle- to oval-shaped atypical cells with and without prominent nucleoli. These cells were like myogenic cells, but negative for myogenic markers. They were positive for endothelial markers, such as ERG, Fli1 and CD31. They were also positive for nuclear and cytoplasmic FOSB which are not expressed in epithelioid hemangioendothelioma or epithelioid sarcoma. These pathological and immunohistochemical findings strongly suggested pseudomyogenic hemangioendothelioma/epithelioid sarcoma-like hemangioendothelioma (PHE/ES-HE). Since a recent report directly proved that two cases of PHE/ES-HE have SERPINE1-FOSB fusion gene by reverse transcription-polymerase chain reaction (RT-PCR), we examined whether the fusion gene is present or not in the present case by RT-PCR using fresh frozen surgical material. Sequencing of the PCR product revealed that this case has SERPINE1-FOSB fusion. The fusion pattern of our case was different from those of two previously reported cases. In our case, 86 nucleotides of SERPINE1 intron 1 were inserted between SERPINE1 exon 1 and the middle portion of FOSB exon 1, and a putative translation start codon was identified in SERPINE1 intron 1. Thus, this is the third case of PHE/ES-HE with SERPINE1-FOSB fusion proved by RT-PCR.

Prediction of response to pegylated interferon/ribavirin combination therapy for chronic hepatitis C genotype 1b and high viral load.

BACKGROUND: This study explores pretreatment predictive factors for ultimate virological responses to pegylated interferon-α (1.5 µg/kg/week) and ribavirin (600-1000 mg/day) (PEG-IFN/RBV) combination therapy for patients infected with hepatitis C virus (HCV)-1b and a high viral load. METHODS: A total of 75 patients underwent PEG-IFN/RBV combination therapy for 48 weeks. HCV amino acid (aa) substitutions in non-structural protein 5a, including those in the IFN/RBV resistance-determining region (IRRDR) and the IFN sensitivity-determining region and the core regions, as well as the genetic variation (rs8099917) near the interleukin 28B (IL28B) gene (genotype TT) were analyzed. RESULTS: Of the 75 patients, 49 % (37/75) achieved a sustained virological response (SVR), 27 % (20/75) showed relapse, and 24 % (18/75) showed null virological response (NVR). Multivariate logistic regression analysis identified IRRDR with 6 or more mutations (IRRDR ≥6) [odds ratio (OR) 11.906, p < 0.0001] and age <60 years (OR 0.228, p = 0.015) as significant determiners of SVR and IL28B minor (OR 14.618, p = 0.0019) and platelets <15 × 10(4)/mm(3) (OR 0.113, p = 0.0096) as significant determiners of NVR. A combination of IRRDR ≥6 and age <60 years improved SVR predictability (93.3 %), and that of IRRDR ≤5 and age ≥60 years improved non-SVR predictability (84.0 %). Similarly, a combination of IL28B minor and platelets <15 × 10(4)/mm(3) improved NVR predictability (85.7 %), and that of IL28B major and platelets ≥15 × 10(4)/mm(3) improved non-NVR (response) (97.1 %) predictability. CONCLUSION: IRRDR ≥6 and age <60 years were significantly associated with SVR. IL28B minor and platelets <15 × 10(4)/mm(3) were significantly associated with NVR. Certain combinations of these factors improved SVR and NVR predictability and could, therefore, be used to design therapeutic strategies.

Sequence heterogeneity in NS5A of hepatitis C virus genotypes 2a and 2b and clinical outcome of pegylated-interferon/ribavirin therapy.

UNLABELLED: Pegylated-interferon plus ribavirin (PEG-IFN/RBV) therapy is a current standard treatment for chronic hepatitis C. We previously reported that the viral sequence heterogeneity of part of NS5A, referred to as the IFN/RBV resistance-determining region (IRRDR), and a mutation at position 70 of the core protein of hepatitis C virus genotype 1b (HCV-1b) are significantly correlated with the outcome of PEG-IFN/RBV treatment. Here, we aimed to investigate the impact of viral genetic variations within the NS5A and core regions of other genotypes, HCV-2a and HCV-2b, on PEG-IFN/RBV treatment outcome. Pretreatment sequences of NS5A and core regions were analyzed in 112 patients infected with HCV-2a or HCV-2b, who were treated with PEG-IFN/RBV for 24 weeks and followed up for another 24 weeks. The results demonstrated that HCV-2a isolates with 4 or more mutations in IRRDR (IRRDR[2a]≥4) was significantly associated with rapid virological response at week 4 (RVR) and sustained virological response (SVR). Also, another region of NS5A that corresponds to part of the IFN sensitivity-determining region (ISDR) plus its carboxy-flanking region, which we referred to as ISDR/+C[2a], was significantly associated with SVR in patients infected with HCV-2a. Multivariate analysis revealed that IRRDR[2a]≥4 was the only independent predictive factor for SVR. As for HCV-2b infection, an N-terminal half of IRRDR having two or more mutations (IRRDR[2b]/N≥2) was significantly associated with RVR, but not with SVR. No significant correlation was observed between core protein polymorphism and PEG-IFN/RBV treatment outcome in HCV-2a or HCV-2b infection. CONCLUSION: The present results suggest that sequence heterogeneity of NS5A of HCV-2a (IRRDR[2a]≥4 and ISDR/+C[2a]), and that of HCV-2b (IRRDR[2b]/N≥2) to a lesser extent, is involved in determining the viral sensitivity to PEG-IFN/RBV therapy.

Polymorphisms of hepatitis C virus non-structural protein 5A and core protein and clinical outcome of pegylated-interferon/ribavirin combination therapy.

OBJECTIVE: Hepatitis C virus (HCV genome) polymorphisms are thought to influence the outcome of pegylated-interferon/ribavirin (PEG-IFN/RBV) therapy. This study aimed to examine non-structural protein 5A (NS5A) polymorphisms, e.g. IFN/RBV resistance-determining region (IRRDR) and IFN sensitivity-determining region (ISDR), and core protein polymorphism as predictive therapeutic markers. METHODS: Pretreatment sequences of NS5A and core regions were analyzed in 68 HCV-1b-infected patients treated with PEG-IFN/RBV. RESULTS: Of 24 patients infected withHCV having an IRRDR with 6 or more mutations (IRRDR≥6), 18 (75%) patients achieved sustained virological response (SVR), whereas only 11 (25%) of 44 patients infected with HCV having IRRDR≤5 did. IRRDR≥6 was significantly associated with SVR (p < 0.0001). On the other hand, ISDR≥2 was significantly associated with relapse (either before [breakthrough] or after end-of-treatment response [ETR[-]relapse]) (p < 0.05) and a point mutation of the core protein from Arg to Gln at position 70 (Gln(70)) was significantly associated with null-response (p < 0.05). Multivariate analysis identified IRRDR≥6 as the only viral genetic factor that independently predicted SVR. CONCLUSION: NS5A (IRRDR and ISDR) and core protein polymorphisms are associated with the outcome of PEG-IFN/RBV therapy for chronic hepatitis C. In particular, IRRDR≥6 is a useful marker for prediction of SVR.

Hepatitis C virus infection promotes hepatic gluconeogenesis through an NS5A-mediated, FoxO1-dependent pathway.

Chronic hepatitis C virus (HCV) infection is often associated with type 2 diabetes. However, the precise mechanism underlying this association is still unclear. Here, using Huh-7.5 cells either harboring HCV-1b RNA replicons or infected with HCV-2a, we showed that HCV transcriptionally upregulated the genes for phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G6Pase), the rate-limiting enzymes for hepatic gluconeogenesis. In this way, HCV enhanced the cellular production of glucose 6-phosphate (G6P) and glucose. PEPCK and G6Pase gene expressions are controlled by the transcription factor forkhead box O1 (FoxO1). We observed that although neither the mRNA levels nor the protein levels of FoxO1 expression were affected by HCV, the level of phosphorylation of FoxO1 at Ser319 was markedly diminished in HCV-infected cells compared to the control cells, resulting in an increased nuclear accumulation of FoxO1, which is essential for sustaining its transcriptional activity. It was unlikely that the decreased level of FoxO1 phosphorylation was mediated through Akt inactivation, as we observed an increased phosphorylation of Akt at Ser473 in HCV-infected cells compared to control cells. By using specific inhibitors of c-Jun N-terminal kinase (JNK) and reactive oxygen species (ROS), we demonstrated that HCV infection induced JNK activation via increased mitochondrial ROS production, resulting in decreased FoxO1 phosphorylation, FoxO1 nuclear accumulation, and, eventually, increased glucose production. We also found that HCV NS5A mediated increased ROS production and JNK activation, which is directly linked with the FoxO1-dependent increased gluconeogenesis. Taken together, these observations suggest that HCV promotes hepatic gluconeogenesis through an NS5A-mediated, FoxO1-dependent pathway.

Sequence heterogeneity of NS5A and core proteins of hepatitis C virus and virological responses to pegylated-interferon/ribavirin combination therapy.

Both host and viral factors have been implicated in influencing the response to pegylated-interferon/ribavirin (PEG-IFN/RBV) therapy for hepatitis C virus (HCV) infection. Among the viral factors, sequence heterogeneity within NS5A and core regions has been proposed. This study aimed to clarify the relationship between virological responses to PEG-IFN/RBV therapy and sequence heterogeneity within NS5A, including the IFN/RBV resistance-determining region (IRRDR), the interferon sensitivity-determining region (ISDR) and the core region. Pretreatment sequences of NS5A and the core regions were analyzed in 57 HCV-1b-infected patients who were to be treated with PEG-IFN/RBV. Of 40 patients infected with HCV having an IRRDR with four or more mutations (IRRDR ≥ 4), 28 (70%) patients achieved a sustained virological response (SVR). On the other hand, only 4 (24%) of 17 patients infected with HCV having an IRRDR with three or fewer mutations (IRRDR ≤ 3) achieved a SVR (P = 0.001). Similarly, 22 (71%) of 31 patients infected with HCV and having an ISDR with one or more mutations (ISDR ≥ 1) achieved a SVR while 10 (38%) of 26 patients infected with HCV and having an ISDR without any mutations (ISDR = 0) achieved a SVR (P = 0.014). As for the core region, there was significant correlation between a single mutation at position 70 (Gln(70) ) and non-SVR (P = 0.02). Notably, Gln(70) was more prominently associated with the null response (P = 0.0007). In conclusion, sequence heterogeneity within the IRRDR and ISDR, and a single point mutation at position 70 of the core region of HCV-1b are likely to be correlated with virological responses to PEG-IFN/RBV therapy.

Analysis of neutralizing antibodies against hepatitis C virus in patients who were treated with pegylated-interferon plus ribavirin.

The role of neutralizing antibodies (NAb) in determining responses to antiviral therapy has not been defined well. By using hepatitis C virus (HCV) cell culture system with the J6/JFH1 strain of HCV genotype 2a, we analyzed NAb responses in patients with chronic hepatitis C who received pegylated-interferon plus ribavirin (PEG-IFN/RBV) antiviral therapy. A total of 65 patients chronically infected with HCV genotype 1b were enrolled in this study. Of all the 65 patients, 34 (52%) patients achieved early virological response (EVR), with the remaining 31 patients (48%) being Non-EVR. Twenty-seven patients (42%) achieved sustained virological response (SVR), with the remaining 38 patients (58%) being Non-SVR. Thus, NAb titers were significantly higher in sera of patients who achieved EVR and SVR than those of Non-EVR and Non-SVR, respectively. Rather unexpectedly, NAb titers did not significantly decrease when measured even one year after disappearance of HCV RNA. On the other hand, when change ratios of NAb titers before and after disappearance of HCV RNA were compared between patients with different treatment outcomes, we noticed that the change ratio of NAb titers of patients who achieved an EVR was significantly lower than that of Non-SVR. In conclusion, our present results suggest that NAb titers were significantly associated with clinical responses to PEG-IFN/RBV therapy.

17ß-estradiol inhibits the production of infectious particles of hepatitis C virus.

Persistent infection with hepatitis C virus causes serious liver diseases, such as chronic hepatitis, hepatic cirrhosis and hepatocellular carcinoma. The male gender is one of the critical factors in progression of hepatic fibrosis due to chronic HCV infection; thus female hormones may play a role in delaying the progression of hepatic fibrosis. It has also been reported that women are more likely than men to clear HCV in the acute phase of infection. These observations lead the present authors to the question: do female hormones inhibit HCV infection? In this study using HCV J6/JFH1 and Huh-7.5 cells, the possible inhibitory effect(s) of female hormones such as 17ß-estradiol (the most potent physiological estrogen) and progesterone on HCV RNA replication, HCV protein synthesis and production of HCV infectious particles (virions) were analyzed. It was found that E2, but not P4, significantly inhibited production of the HCV virion without inhibiting HCV RNA replication or HCV protein synthesis. E2-mediated inhibition of HCV virion production was abolished by a nuclear estrogen receptor (ER) antagonist ICI182780. Moreover, treatment with the ERα-selective agonist 4, 4', 4″- (4-propyl-[1H]-pyrazole-1, 3, 5-triyl)trisphenol (PPT), but not with the ERß-selective agonist 2, 3-bis (4-hydroxyphenyl)-propionitrile (DPN) or the G protein-coupled receptor 30 (GPR30)-selective agonist 1-(4-[6-bromobenzo 1, 3 dioxol-5-yl]-3a, 4, 5, 9b-tetrahydro-3H-cyclopenta [c] quinolin-8-yl)-ethanone (G-1), significantly inhibited HCV virion production. Taken together, the present results suggest that the most potent physiological estrogen, E2, inhibits the production of HCV infectious particles in an ERα-dependent manner.

A transgenic mouse line with a 58-kb fragment deletion in chromosome 11E1 that encompasses part of the Fam20a gene and its upstream region shows growth disorder.

Growth disorder is an umbrella term for a range of abnormal growth patterns, such as unusually fast or slow growth in infants or children. The causes of growth disorder include hormonal irregularities, chronic disease, complications during pregnancy or genetic conditions. A complex trait such as body size is influenced by multiple genes as well as environmental factors, giving rise to a continuous spectrum of phenotypes. This causal complexity makes discovery of the genetic determinants of growth disorder rather difficult. We here report our discovery of a transgenic mouse line exhibiting growth disorder, which we happened to discover in the course of generating transgenic mice expressing a viral gene. Although these mice did not express any corresponding viral mRNA or protein due to a deletion in the transgene, they showed slow growth in the 5 weeks after birth and ceased growing thereafter, while maintaining a weight equivalent to that of 3-week-old normal mice. Histopathological analysis of the organs of these mice revealed that malnutrition and metabolic disorder occurred at 5 weeks after birth in the liver. Genetic analysis has revealed that the growth disorder is associated with a 58-kb fragment deletion in chromosome 11E1 that encompasses part of the Fam20a gene and part of its upstream region. The present study thus points out for the first time the possible link between Fam20a mutation and growth disorder.

Computed tomography and scintigraphy vs. cardiac catheterization for coronary disease screening prior to noncardiac surgery.

OBJECTIVE: The goal of this study was to investigate the utility of multidetector-row computed tomography (MDCT) and adenosine triphosphate stress cardiac single photon emission computed tomography (ATP-SPECT) in evaluating coronary artery disease (CAD) in patients scheduled for non-cardiac surgery. PATIENTS AND METHODS: We routinely performed echocardiography and exercise stress electrocardiography as preoperative cardiac screening examinations for patients scheduled for non-cardiac surgery under general anesthesia. Of 848 consecutive preoperative patients (Non-invasive Group), 49 patients with abnormalities of these screening examinations had MDCT and ATP-SPECT. Of 809 consecutive preoperative patients studied at an earlier time (Invasive Group), 58 patients with abnormalities of these screening examinations had cardiac catheterization as an additional cardiac examination. RESULTS: The number of patients in the non-invasive and invasive subgroups having additional screening examinations was comparable, and there was no significant difference in perioperative cardiac events between the two subgroups. Based on results of the additional tests in the two subgroups, preoperative prophylactic invasive treatment for CAD was carried out in a small number of patients, again with no significant differences between the groups. However, total medical expenses for the additional cardiac examinations were significantly reduced in the non-invasive subgroup compared with the invasive subgroup (140,030+/-34,800 vs. 187,170+/-26,120 yen, respectively, p=0.0002). CONCLUSION: Non-invasive examination prior to noncardiac surgery using MDCT and ATP-SPECT in a subgroup of patients suspected of having CAD appears to be a useful screening procedure. Compared with invasive cardiac catheterization, CT testing has comparable diagnostic utility without an increase in perioperative cardiac events, and in addition, it has an improved cost-benefit profile.

Single-point mutations of the M protein of a measles virus variant obtained from a patient with subacute sclerosing panencephalitis critically affect solubility and subcellular localization of the M protein and cell-free virus production.

Subacute sclerosing panencephalitis (SSPE) is caused by variants of wild-type measles virus (MV). Such MV variants lack almost completely the ability to produce cell-free progeny virus. We recently isolated an MV variant that has only three amino acid mutations (L165P,L250P and Y282H) in the M protein compared with MV field isolates of the same genotype. In the present study, we analyzed the significance of these mutations with regard to the characteristics of the M protein and progeny virus production. We found that each of the three mutations rendered the M protein insoluble in 0.5% Triton X-100 and altered its subcellular localization, either when ectopically expressed alone using a plasmid-based expression system or when expressed in the context of viral replication. Moreover, each of the three mutations markedly, but not completely, impaired the ability of MV to produce cell-free progeny virus, with the degree of impairment being the same as for all three mutations together. These results suggest the possibility that the changes in the solubility and subcellular localization of the M protein determine the ability to produce cell-free progeny virus, at least to some extent, and play a role in the pathogenicity of variants causing SSPE.

Efficient production of infectious hepatitis C virus with adaptive mutations in cultured hepatoma cells.

Robust production of infectious hepatitis C virus (HCV) in cell culture was realized by using the JFH1 strain and the homologous chimeric J6/JFH1 strain in Huh-7.5 cells, a highly HCV-permissive subclone of Huh-7 cells. In this study, we aimed to establish a more efficient HCV-production system and to gain some insight into the adaptation mechanisms of efficient HCV production. By serial passaging of J6/JFH1-infected Huh-7.5 cells, we obtained culture-adapted J6/JFH1 variants, designated P-27, P-38 and P-47. Sequence analyses revealed that the adaptive mutant viruses P-27, P-38 and P-47 possessed eight mutations [four in E2, two in NS2, one in NS5A and one in NS5B), 10 mutations [two additional mutations in the 5'-untranslated region (5'-UTR) and core] and 11 mutations (three additional mutations in 5'-UTR, core and NS5B), respectively. We introduced amino acid substitutions into the wild-type J6/JFH1 clone, generated recombinant viruses with adaptive mutations and analysed their infectivity and ability to produce infectious viruses. The viruses with the adaptive mutations exhibited higher expression of HCV proteins than did the wild type in Huh-7.5 cells. Moreover, we provide evidence suggesting that the mutation N534H in the E2 glycoprotein of the mutant viruses conferred an advantage at the entry level. We thus demonstrate that an efficient HCV-production system could be obtained by introducing adaptive mutations into the J6/JFH1 genome. The J6/JFH1-derived mutant viruses presented here would be a good tool for producing HCV particles with enhanced infectivity and for studying the molecular mechanism of HCV entry.