Impact of amino acid substitutions in hepatitis C virus core region on the severe oxidative stress

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, leading to liver steatosis, fibrosis, and hepatocellular carcinoma (HCC). Despite the accumulation of clinical data showing the impact of amino acid substitutions at positions 70 (R70Q/H) and/or 91 (L91M) in the HCV core protein in progressive liver diseases, including HCC, the underlying mechanisms have not been elucidated. We analyzed 72 liver biopsy specimens from patients with chronic HCV genotype 1b (HCV-1b) infection prior to antiviral treatment. Levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and nuclear factor erythroid 2-related factor 2 (NRF2) in the nucleus were quantified using liver tissue immunohistochemistry. The effects of amino acid substitutions in the HCV core region on hepatocellular oxidative stress were investigated using wild-type or double-mutant (R70Q/H+L91M) HCV-1b core transfection and stable expression in human hepatoma HuH-7 cells. Overall, 24, 19, 11, and 18 patients had the wild-type, R70Q/H, L91M, and R70Q/H+L91M genotypes, respectively, in the HCV core. A significantly higher accumulation of hepatocellular 8-OHdG and a lower NRF2/8-OHdG ratio were observed in patients with R70Q/H+L91M than in those with the wild-type disease. Increased levels of intracellular superoxide and hydrogen peroxide in the cytoplasm and mitochondria, mRNA expression of enzymes generating oxidative stress, and nuclear expression of nicotinamide adenine dinucleotide phosphate oxidase 4 were augmented in cells treated with R70Q+L91M. HCV core proteins harboring either or both substitutions of R70Q/H or L91M enhanced hepatocellular oxidative stress in vivo and in vitro. These amino acid substitutions may affect HCC development by enhancing hepatic oxidative stress in patients with chronic HCV-1b infection.

SRPKIN-1 as an inhibitor against hepatitis B virus blocking the viral particle formation and the early step of the viral infection

New antiviral agents are needed for the treatment of hepatitis B virus (HBV) infection because currently available drugs do not completely eradicate chronic HBV in patients. Phosphorylation dynamics of the HBV core protein (HBc) regulate several processes in the HBV life cycle, including nucleocapsid formation, cell trafficking, and virus uncoating after entry. In this study, the SRPK inhibitors SPHINX31, SRPIN340, and SRPKIN-1 showed concentration-dependent anti-HBV activity. Detailed analysis of the effects of SRPKIN-1, which exhibited the strongest inhibitory activity, on the HBV replication process showed that it inhibits the formation of infectious particles by inhibiting pregenomic RNA packaging into capsids and nucleocapsid envelopment. Mass spectrometry analysis combined with cell-free translation system experiments revealed that hyperphosphorylation of the C-terminal domain of HBc is inhibited by SRPKIN-1. Further, SRPKIN-1 exhibited concentration-dependent inhibition of HBV infection not only in HepG2-hNTCP-C4 cells but also in fresh human hepatocytes (PXB cells) and in the single-round infection system. Treatment with SRPKIN-1 at the time of infection reduced the nuclease sensitivity of HBV DNA in the nuclear fraction. These results suggest that SRPKIN-1 has the potential to not only inhibit the HBV particle formation process but also impair the early stages of viral infection.

Inhibition of integrin binding to ligand arg-gly-asp motif induces AKT-mediated cellular senescence in hepatic stellate cells

BACKGROUND & AIMS

Hepatic stellate cells (HSCs) play an essential role in liver fibrogenesis. The induction of cellular senescence has been reported to inhibit HSC activation. Previously, we demonstrated that CWHM12, a small molecule arginine-glycine-aspartic acid (RGD) peptidomimetic compound, inhibits HSC activation. This study investigated whether the inhibitory effects of CWHM12 on HSCs affected cellular senescence.

METHODS

The immortalized human HSC lines, LX-2 and TWNT-1, were used to evaluate the effects of CWHM12 on cellular senescence via the disruption of RGD-mediated binding to integrins.

RESULTS

CWHM12 induces cell cycle arrest, senescence-associated beta-galactosidase activity, acquisition of senescence-associated secretory phenotype (SASP), and expression of senescence-associated proteins in HSCs. Further experiments revealed that the phosphorylation of AKT and murine double minute 2 (MDM2) was involved in the effects of CWHM12, and the inhibition of AKT phosphorylation reversed these effects of CWHM12 on HSCs.

CONCLUSIONS

Pharmacological inhibition of RGD-mediated integrin binding induces senescence in activated HSCs.

Role of hepcidin upregulation and proteolytic cleavage of ferroportin 1 in hepatitis C virus-induced iron accumulation

Hepatitis C virus (HCV) is a pathogen characterized not only by its persistent infection leading to the development of cirrhosis and hepatocellular carcinoma (HCC), but also by metabolic disorders such as lipid and iron dysregulation. Elevated iron load is commonly observed in the livers of patients with chronic hepatitis C, and hepatic iron overload is a highly profibrogenic and carcinogenic factor that increases the risk of HCC. However, the underlying mechanisms of elevated iron accumulation in HCV-infected livers remain to be fully elucidated. Here, we observed iron accumulation in cells and liver tissues under HCV infection and in mice expressing viral proteins from recombinant adenoviruses. We established two molecular mechanisms that contribute to increased iron load in cells caused by HCV infection. One is the transcriptional induction of hepcidin, the key hormone for modulating iron homeostasis. The transcription factor cAMP-responsive element-binding protein hepatocyte specific (CREBH), which was activated by HCV infection, not only directly recognizes the hepcidin promoter but also induces bone morphogenetic protein 6 (BMP6) expression, resulting in an activated BMP-SMAD pathway that enhances hepcidin promoter activity. The other is post-translational regulation of the iron-exporting membrane protein ferroportin 1 (FPN1), which is cleaved between residues Cys284 and Ala285 in the intracytoplasmic loop region of the central portion mediated by HCV NS3-4A serine protease. We propose that host transcriptional activation triggered by endoplasmic reticulum stress and FPN1 cleavage by viral protease work in concert to impair iron efflux, leading to iron accumulation in HCV-infected cells.

Simvastatin inhibits hepatic stellate cells activation by regulating the ferroptosis signaling pathway

BACKGROUND & AIMS

Ferroptosis is a form of regulated cell death and its promotion in hepatic stellate cells (HSCs) attenuates liver fibrosis. Statins, which are 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, may induce ferroptosis via the downregulation of glutathione peroxidase 4 (GPX4) by inhibiting the mevalonate pathway. However, little evidence is available regarding the association between statins and ferroptosis. Therefore, we investigated the association between statins and ferroptosis in HSCs.

METHODS

Two human HSC cell lines, LX-2 and TWNT-1, were treated with simvastatin, an HMG-CoA reductase inhibitor. Mevalonic acid (MVA), farnesyl pyrophosphate (FPP), and geranylgeranyl pyrophosphate (GGPP) were used to determine the involvement of the mevalonate pathway. We performed a detailed analysis of the ferroptosis signaling pathway. We also investigated human liver tissue samples from patients with nonalcoholic steatohepatitis to clarify the effect of statins on GPX4 expression.

RESULTS

Simvastatin reduced cell mortality and inhibited HSCs activation, accompanied by iron accumulation, oxidative stress, lipid peroxidation, and reduced GPX4 protein expression. These results indicate that simvastatin inhibits HSCs activation by promoting ferroptosis. Furthermore, treatment with MVA, FPP, or GGPP attenuated simvastatin-induced ferroptosis. These results suggest that simvastatin promotes ferroptosis in HSCs by inhibiting the mevalonate pathway. In human liver tissue samples, statins downregulated the expression of GPX4 in HSCs without affecting hepatocytes.

CONCLUSIONS

Simvastatin inhibits the activation of HSCs by regulating the ferroptosis signaling pathway.

Persistent hepatic IFN system activation in HBV-HDV infection determines viral replication dynamics and therapeutic response

Hepatitis delta virus (HDV), a satellite virus of HBV, is regarded as the most severe type of hepatitis virus because of the substantial morbidity and mortality. The IFN system is the first line of defense against viral infections and an essential element of antiviral immunity; however, the role of the hepatic IFN system in controlling HBV-HDV infection remains poorly understood. Herein, we showed that HDV infection of human hepatocytes induced a potent and persistent activation of the IFN system whereas HBV was inert in triggering hepatic antiviral response. Moreover, we demonstrated that HDV-induced constitutive activation of the hepatic IFN system resulted in a potent suppression of HBV while modestly inhibiting HDV. Thus, these pathogens are equipped with distinctive immunogenicity and varying sensitivity to the antiviral effectors of IFN, leading to the establishment of a paradoxical mode of viral interference wherein HDV, the superinfectant, outcompetes HBV, the primary pathogen. Furthermore, our study revealed that HDV-induced constitutive IFN system activation led to a state of IFN refractoriness, rendering therapeutic IFNs ineffective. The present study provides potentially novel insights into the role of the hepatic IFN system in regulating HBV-HDV infection dynamics and its therapeutic implications through elucidating the molecular basis underlying the inefficacy of IFN-based antiviral strategies against HBV-HDV infection.

Breach of tolerance versus burden of bile acids: Resolving the conundrum in the immunopathogenesis and natural history of primary biliary cholangitis

Primary biliary cholangitis (PBC) is a classic autoimmune disease due to the loss of tolerance to self-antigens. Bile acids (BA) reportedly play a major role in biliary inflammation and/or in the modulation of dysregulated immune responses in PBC. Several murine models have indicated that molecular mimicry plays a role in autoimmune cholangitis; however, they have all been limited by the relative failure to develop hepatic fibrosis. We hypothesized that species-specific differences in the BA composition between mice and humans were the primary reason for this limited pathology. Here, we aimed to study the impact of human-like hydrophobic BA composition on the development of autoimmune cholangitis and hepatic fibrosis. We took advantage of a unique construct, Cyp2c70/Cyp2a12 double knockout (DKO) mice, which have human-like BA composition, and immunized them with a well-defined mimic of the major mitochondrial autoantigen of PBC, namely 2-octynoic acid (2OA). 2OA-treated DKO mice were significantly exacerbated portal inflammation and bile duct damage with increased Th1 cytokines/chemokines at 8 weeks post-initial immunization. Most importantly, there was clear progression of hepatic fibrosis and increased expression of hepatic fibrosis-related genes. Interestingly, these mice demonstrated increased serum BA concentrations and decreased biliary BA concentrations; hepatic BA levels did not increase because of the upregulation of transporters responsible for the basolateral efflux of BA. Furthermore, cholangitis and hepatic fibrosis were more advanced at 24 weeks post-initial immunization. These results indicate that both the loss of tolerance and the effect of hydrophobic BA are essential for the progression of PBC.

A Case of Hepatic Angiosarcoma with Peliosis Hepatis

A 59-year-old woman presented to our hospital with liver dysfunction. Imaging revealed multiple lesions in the liver. The patient was diagnosed with peliosis hepatis using percutaneous and laparoscopic biopsies. However, her condition worsened with the appearance of new, obvious mass-forming lesions. Therefore, she underwent a second percutaneous biopsy of these lesions and was diagnosed with hepatic angiosarcoma. Her condition progressed rapidly, and she died two weeks after the diagnosis. Diagnosis of hepatic angiosarcoma in the early stages is difficult. It should be noted that hepatic angiosarcoma may be associated with the development of peliosis hepatis.

Arg-Gly-Asp-binding integrins activate hepatic stellate cells via the hippo signaling pathway

BACKGROUND & AIMS

Liver fibrosis characterizes advanced chronic liver disease, and persistent activation of hepatic stellate cells (HSCs) is the primary cause of excessive hepatic fibrogenesis. CWHM12, an analog of the arginine-glycine-aspartic acid (RGD) amino acid sequence found in specific integrins, improves liver fibrosis; however, the detailed mechanisms remain unclear. This study aimed to clarify the cell signaling mechanisms of CWHM12 in activated HSCs.

METHODS

Immortalized human HSC lines, LX-2 and TWNT-1, were used to evaluate the effects of CWHM12 on intracellular signaling via the disruption of RGD-binding integrins.

RESULTS

CWHM12 strongly promoted phosphorylation and inhibited the nuclear accumulation of Yes-associated protein (YAP), which is a critical effector of the Hippo signaling pathway, leading to the inhibition of proliferation, suppression of viability, promotion of apoptosis, and induction of cell cycle arrest at the G1 phase in activated HSCs. Further investigations revealed that inhibition of TGF-β was involved in the consequences of CWHM12. Moreover, CWHM12 suppressed focal adhesion kinase (FAK) phosphorylation; consequently, Src, phosphatidylinositol 3-kinase, pyruvate dehydrogenase kinase 1, and serine-threonine kinase phosphorylation led to the translocation of YAP. These favorable effects of CWHM12 on activated HSCs were reversed by inhibiting FAK.

CONCLUSIONS

These results indicate that pharmacological inhibition of RGD-binding integrins suppresses activated HSCs by blocking the Hippo signaling pathway, a cellular response which may be valuable in the treatment of hepatic fibrosis.

Mac-2-binding protein glycan isomer predicts all malignancies after sustained virological response in chronic hepatitis C

Despite reports of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C virus (HCV) infection after achieving sustained virological response (SVR), only few studies have demonstrated the incidence of other (non-HCC) malignancies. This study aimed to clarify the incidence, survival probability, and factors associated with malignancy, especially non-HCC malignancies, in patients with chronic HCV infection after achieving SVR. In this retrospective study, records of 3580 patients with chronic HCV infection who achieved SVR following direct-acting antiviral (DAA) treatment were analyzed. The cumulative post-SVR incidence of non-HCC malignancies was 0.9%, 3.1%, and 6.8% at 1, 3, and 5 years, respectively. The survival probability for patients with non-HCC malignancies was 99.1%, 78.8%, and 60.2% at 1, 3, and 5 years, respectively, and the rate was significantly lower than that for patients with HCC. The Cox proportional hazards regression model identified Mac-2-binding protein glycan isomer (M2BPGi) cutoff index (COI) ≥ 1.90 at baseline and ≥ 1.50 at 12 weeks following DAA treatment as significant and independent factors associated with the post-SVR incidence of non-HCC malignancies. Furthermore, patients with either M2BPGi COI ≥ 1.90 at baseline or M2BPGi COI ≥ 1.50 at SVR12 had a significantly higher risk of post-SVR incidence of non-HCC malignancies than of HCC. Conclusion: M2BPGi measurements at baseline and SVR12 may help predict the post-SVR incidence of non-HCC malignancies in patients with chronic HCV infection who achieved SVR following DAA treatment. Early identification of these patients is critical to prolong patient survival.

High Prevalence of Chronic Viral Hepatitis and Liver Fibrosis Among Mongols in Southern California

BACKGROUND

Mongolia is a highly endemic region for chronic hepatitis B (HBV), hepatitis delta (HDV), and hepatitis C (HCV) infections. Aim of this study was to comprehensively characterize chronic viral hepatitis among Mongols living in Southern California.

METHODS

Three screening events were conducted between August and November 2018, with 528 adult Mongols tested for HBV and HCV. HBsAg (+) individuals (CHB) underwent additional testing for HDV RNA and anti-HDV. Liver tests, platelet count, and FibroScan™ were performed on CHB and chronic HCV (CHC) individuals.

RESULTS

Fifty-one out of 534 were HBsAg reactive (9.7%), and all were foreign-born. Mean age of CHB individuals was 37.8 (range 18-69) years. Forty-six out of 51 were HBeAg (-). HBV genotypes were exclusively D2 or A1. Twenty-one out of 51 (41.2%) were anti-HDV (+) and 17/51 (33.3%) were HDV RNA (+). HDV RNA (+) individuals had significantly higher ALT, fibrosis-4 score, and liver stiffness compared to HDV RNA (-) individuals. Incidence of advanced fibrosis was higher in HDV RNA (+) individuals (57% vs. 13%, p = 0.013). Forty-eight (9.1%) individuals were anti-HCV (+) and 19 (3.6%) were HCV RNA (+). Mean age of CHC individuals was 40.2 (range 28-71) years. Prevalence of anti-HCV (+) was higher among those born between 1945 and 1965 versus those born after 1965 (18.8% vs. 7.9%, p = 0.025). Genotype 1b was predominant. Incidence of cirrhosis was 7% among all participants.

CONCLUSIONS

Mongols living in the USA are at high risk for CHB and CHC infections. One-third of CHB individuals had CHD superinfection with advanced fibrosis. Universal screening for viral hepatitis in Mongols in the USA is mandatory.

Ursodeoxycholic acid impairs liver-infiltrating T-cell chemotaxis through IFN-γ and CX3CL1 production in primary biliary cholangitis

Ursodeoxycholic acid (UDCA) is the primary treatment for primary biliary cholangitis (PBC), but its mechanism of action remains unclear. Studies suggest that UDCA enhances NF erythroid 2-related factor 2 (NFE2L2) expression and that the interaction between IFN-γ and C-X3-C motif chemokine ligand 1 (CX3CL1) facilitates biliary inflammation in PBC. Therefore, we examined the effects of UDCA on the expression of IFN-γ and CX3CL1 in in vitro and in vivo PBC models such as human liver tissue, a murine model, cell lines, and isolated human intrahepatic biliary epithelial cells (IHBECs). We observed a significant decrease in IFN-γ mRNA levels and positive correlations between IFN-γ and CX3CL1 mRNA levels post-UDCA treatment in PBC livers. NFE2L2-mediated transcriptional activation was significantly enhanced in UDCA-treated Jurkat cells. In 2-octynoic acid-immunized mice, IFN-γ production by liver-infiltrating T cells was dependent on NFE2L2 activation. IFN-γ significantly and dose-dependentlyinduced CX3CL1 expression, which was significantly decreased in HuCC-T1 cells and IHBECs upon UDCA treatment. These results suggest that UDCA-induced suppression of IFN-γ and CX3CL1 production attenuates the chemotactic and adhesive abilities of liver-infiltrating T cells in PBC.

Clinical characteristics and risk factors for stent-stone complex formation following biliary plastic stent placement in patients with common bile duct stones

BACKGROUND

Stent-stone complex (SSC) formation is one of the complications of endoscopic biliary stent placement. This study aimed to clarify the clinical characteristics and risk factors for SSC formation following plastic stent (PS) placement in patients with common bile duct (CBD) stones.

METHODS

We retrospectively reviewed the charts of 78 patients with CBD stones who had undergone 107 biliary stent placements as palliative treatment. Demographic, historical, and stent-related data were collected and analyzed.

RESULTS

At PS removal, SSC formations were observed in 18% of the 107 cases (SSC group) studied and not in the remaining 82% (non-SSC group). The duration of PS placement was significantly longer in the SSC group. The increase in CBD diameter during the stenting period as well as the incidence of cholangitis at PS removal was significantly greater in the SSC group. Multivariate analysis identified long-term (≥301 days) PS placement and the increase in CBD diameter during the stenting period as independent factors for SSC formation.

CONCLUSIONS

Long-term PS placement induces a risk of SSC formation in patients with CBD stones. The increase in diameter of CBD during the period of PS placement is a predictive factor for SSC formation in this situation.

[A case of obstructive pancreatitis induced by extramedullary pancreatic metastasis in a patient with immunoglobulin D multiple myeloma]

A 51-year-old Brazilian female who had IgD-lambda type multiple myeloma presented with epigastralgia and obstructive jaundice during her follow-up. Contrast-enhanced computed tomography (CT) showed an enhanced mass of 25mm in the pancreatic head, and endoscopic retrograde cholangiopancreatography revealed smooth stenoses in the lower bile duct and main pancreatic duct (MPD) of the head. We diagnosed the patient with extramedullary pancreatic metastasis of multiple myelomas. Plastic stents were endoscopically placed into both the common bile duct and MPD. One week later, she suffered a repeat episode of epigastralgia. A subsequent CT scan showed obstructive pancreatitis due to another mass, 30mm in size, emerging rapidly in the pancreatic body. Pancreatitis improved after we replaced the plastic stent with a longer one so that the distal end reached beyond the stenosis at the MPD of the body. Although both the tumors were treated with radiotherapy and showed temporary reduction, the patient died 1 month later due to progression of the disease. While cases involving obstructive pancreatitis induced by extramedullary pancreatic metastasis of multiple myelomas are very rare, it is crucial that such patients are rapidly diagnosed and treated.

Rapid Changes in Serum Lipid Profiles during Combination Therapy with Daclatasvir and Asunaprevir in Patients Infected with Hepatitis C Virus Genotype 1b

Background/Aims

Changes in lipid profiles in patients infected with hepatitis C virus (HCV) during direct-acting antiviral therapy have been reported in recent years. However, the clinical aspects of disturbed lipid metabolism in chronic HCV infection have not been fully elucidated.

Methods

Dynamic changes in serum total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol and apolipoprotein levels in patients infected with HCV genotype 1b were examined during combination therapy with daclatasvir (DCV) and asunaprevir (ASV).

Results

Total, LDL−, and HDL-cholesterol levels increased rapidly and persistently after week 4. Apolipoprotein (apo) A-I, apo B, apo C-II, and apo C-III levels were significantly higher at week 4 than at week 0. In contrast, apo A-II and apo E levels were significantly lower. The differences in LDL− and HDL-cholesterol levels were positively correlated with those of apo B and apo A-I, respectively. Interestingly, in patients with non-sustained virological response, these cholesterol levels decreased rapidly after viral breakthrough or viral relapse. Furthermore, similar changes were observed for apo A-I, apo B and apo C-III levels.

Conclusions

Clearance of HCV using combination therapy with DCV and ASV results in rapid changes in serum lipid profiles, suggesting an influence of HCV infection on disturbed lipid metabolism.

[Spontaneous regression of pancreatic arteriovenous malformation under the influence of severe acute pancreatitis: a case report]

A 49-year-old man was diagnosed with severe acute pancreatitis because of pancreatic arteriovenous malformation (AVM). The pancreatic AVM spontaneously regressed during conservative treatment for severe acute pancreatitis. Transarterial embolization of an aneurysm in an artery branch flowing into the pancreatic AVM was performed using metallic coils, following amelioration of severe acute pancreatitis. The complete elimination of the pancreatic AVM was confirmed 1 year after embolization, and the patient has had no recurrence of pancreatic AVM and pancreatitis for over 6 years. Most cases of pancreatic AVMs with acute pancreatitis require surgical resection. This is a rare case in which the pancreatic AVM spontaneously regressed under the influence of acute severe pancreatitis.

Critical role of CREBH-mediated induction of transforming growth factor β2 by hepatitis C virus infection in fibrogenic responses in hepatic stellate cells

Mechanisms of hepatic fibrogenesis induced by hepatitis C virus (HCV), one of the leading causes of liver fibrosis, are not fully understood. We studied transcriptional up-regulation of transforming growth factor β (TGF-β), especially TGF-β2, which is mediated by activation of liver-enriched transcription factor cAMP-responsive element-binding protein, hepatocyte specific (CREBH) triggered by HCV infection and its functional significance for induction of profibrogenic phenotypes by interaction of HCV-infected cells with hepatic stellate cells (HSCs). Compared to TGF-β1, expression of TGF-β2 mRNA was induced faster and to a higher level upon HCV infection. Serum TGF-β2 levels in hepatitis C patients were higher compared to those in healthy individuals and were positively correlated with hepatic fibrosis stages F0-F2. TGF-β2 promoter activity was decreased and increased, respectively, by silencing and overexpression of CREBH. CREBH recognition sites were identified in the TGF-β2 promoter. CREBH binding to the promoter and its increase in cells expressing HCV Core-NS2 were shown by gel mobility shift and chromatin immunoprecipitation, respectively. The active form of CREBH was detectable in HCV-infected chimeric mice with human livers and cells expressing HCV proteins. Involvement of CREBH in HCV-induced fibrogenic response was further demonstrated in the CREBH null-mutant mouse model. Fibrogenic phenotypes were assessed using co-cultures of HCV-infected cells and HSCs. Expressions of fibrogenic factors and TGF-β1 increasing in the co-cultures was prevented by TGF-β2- or CREBH silencing.

CONCLUSION

CREBH was identified as a key positive regulator of TGF-β2 transcription in HCV-infected cells. TGF-β2 released from infected cells potentially contributes to cross-induction of TGF-β in an autocrine manner through its own signaling pathway, leading to an increase in fibrogenic responses in adjacent HSCs. (Hepatology 2017;66:1430-1443).

Involvement of PUF60 in Transcriptional and Post-transcriptional Regulation of Hepatitis B Virus Pregenomic RNA Expression

Here we identified PUF60, a splicing factor and a U2 small nuclear ribonucleoprotein auxiliary factor, as a versatile regulator of transcriptional and post-transcriptional steps in expression of hepatitis B virus (HBV) 3.5 kb, precore plus pregenomic RNA. We demonstrate that PUF60 is involved in: 1) up-regulation of core promoter activity through its interaction with transcription factor TCF7L2, 2) promotion of 3.5 kb RNA degradation and 3) suppression of 3.5 kb RNA splicing. When the 1.24-fold HBV genome was introduced into cells with the PUF60-expression plasmid, the 3.5 kb RNA level was higher at days 1–2 post-transfection but declined thereafter in PUF60-expressing cells compared to viral replication control cells. Deletion analyses showed that the second and first RNA recognition motifs (RRMs) within PUF60 are responsible for core promoter activation and RNA degradation, respectively. Expression of PUF60 mutant deleting the first RRM led to higher HBV production. To our knowledge, this is the first to identify a host factor involved in not only positively regulating viral gene expression but also negative regulation of the same viral life cycle. Functional linkage between transcriptional and post-transcriptional controls during viral replication might be involved in mechanisms for intracellular antiviral defense and viral persistence.

LUC7L3/CROP inhibits replication of hepatitis B virus via suppressing enhancer II/basal core promoter activity

The core promoter of hepatitis B virus (HBV) genome is a critical region for transcriptional initiation of 3.5 kb, pregenome and precore RNAs and for the viral replication. Although a number of host-cell factors that potentially regulate the viral promoter activities have been identified, the molecular mechanisms of the viral gene expression, in particular, regulatory mechanisms of the transcriptional repression remain elusive. In this study, we identified LUC7 like 3 pre-mRNA splicing factor (LUC7L3, also known as hLuc7A or CROP) as a novel interacting partner of HBV enhancer II and basal core promoter (ENII/BCP), key elements within the core promoter, through the proteomic screening and found that LUC7L3 functions as a negative regulator of ENII/BCP. Gene silencing of LUC7L3 significantly increased expression of the viral genes and antigens as well as the activities of ENII/BCP and core promoter. In contrast, overexpression of LUC7L3 inhibited their activities and HBV replication. In addition, LUC7L3 possibly contributes to promotion of the splicing of 3.5 kb RNA, which may also be involved in negative regulation of the pregenome RNA level. This is the first to demonstrate the involvement of LUC7L3 in regulation of gene transcription and in viral replication.

Successful Interferon Therapy Reverses Enhanced Hepatic Progenitor Cell Activation in Patients with Chronic Hepatitis C

The enhanced accumulation of hepatic progenitor cells (HPCs) is related to the risk of progression to hepatocellular carcinoma (HCC). Interferon (IFN) treatment reduces HCC risk in patients with chronic hepatitis C virus (HCV) infection. However, the underlying mechanisms remain unclear. The aim of this study was to examine the effects of IFN treatment on HPC activation in HCV patients. Immunohistochemical detection and computer-assisted quantitative image analyses of cytokeratin 7 (CK7) were performed to evaluate HPC activation in paired pre- and post-treatment liver biopsies from 18 HCV patients with sustained virological response (SVR) to IFN-based therapy and from 23 patients without SVR, as well as normal liver tissues obtained from surgical resection specimens of 10 patients. Pretreatment HCV livers showed increased CK7 immunoreactivity, compared with normal livers (HCV: median, 1.38%; normal: median, 0.69%, P=0.006). IFN treatment reduced hepatic CK7 immunoreactivity (median, 1.57% pre-IFN vs. 0.69% post-IFN, P=0.006) in SVR patients, but not in non-SVR patients. The development of HCC following IFN treatment was encountered in 3 non-SVR patients who showed high post-IFN treatment CK7 immunoreactivity (>4%). Successful IFN therapy can reverse enhanced HPC activation in HCV patients, which may contribute to the reduced risk of HCC development in these patients.

Long-term pegylated interferon monotherapy following 72 weeks of pegylated interferon and ribavirin in hepatitis C virus genotype-1-infected slow responders

OBJECTIVE

Slow responders to pegylated interferon (Peg-IFN) and ribavirin (RBV) among patients infected with hepatitis C virus (HCV) genotype 1 may benefit from an extended treatment course. The aim of this study was to determine the efficacy of persistent negative serum HCV RNA over 96 weeks during long-term Peg-IFN monotherapy following 72 weeks of combination therapy.

METHODS

A total of 46 HCV genotype 1-infected slow responders were treated for 72 weeks with Peg-IFN and RBV combination therapy alone (n=25) or additional long-term biweekly treatment with 90 μg of Peg-IFN-α2a (n=21). The criterion for the completion of long-term Peg-IFN monotherapy was defined as the attainment of constantly negative HCV RNA in the serum over 96 weeks during IFN treatment.

RESULTS

The patients with sustained negative serum HCV RNA during 96 weeks of IFN treatment had a higher rate of sustained virological response (SVR) than those without (81 vs. 40%, p=0.012). A multivariate analysis identified sustained negativity of serum HCV RNA over 96 weeks of IFN treatment to be a predictive factor for SVR.

CONCLUSION

In the present study, sustained negative serum HCV RNA over 96 weeks during long-term Peg-IFN monotherapy following 72 weeks of combination therapy of Peg-IFN and RBV resulted in beneficial virological outcomes among HCV genotype 1-infected slow responders.

Does hepatic oxidative stress enhance activation of nuclear factor-E2-related factor in patients with nonalcoholic steatohepatitis?

The imbalance of hepatic oxidant and antioxidant status is an important pathophysiological mechanism in nonalcoholic steatohepatitis (NASH). The nuclear factor-E2-related factor (Nrf2) is a key transcription factor regulating a plethora of antioxidant genes involved in antioxidant defense. To clarify the mechanisms of hepatic antioxidant defenses in human NASH, the aim of the current study was to examine oxidative stress-induced Nrf2 activation in the livers of patients with NASH. Liver biopsies were obtained from 19 NASH patients. Normal liver tissue was obtained from surgical resection specimens of 15 patients. The proportion of hepatocytes with 8-hydroxydeoxyguanosine (8-OHdG)-positive nuclei was increased in NASH livers compared with that in normal livers. Hepatic Nrf2 protein levels were increased with enhanced accumulation of hepatocellular nuclear Nrf2, which was positively correlated with that of 8-OHdG. Hepatic expression of γ-glutamylcysteine synthetase (γGCS), glutathione peroxidase 2 (GPx2), thioredoxin (TRX), and heme oxygenese 1 (HO-1), but not thioredoxin reductase 1 (TrxR1), was upregulated, and the protein levels of γGCS were positively correlated with those of Nrf2. Collectively, our findings lead to the hypothesis that oxidative stress may enhance Nrf2 activation in the livers of patients with NASH.

[A case of hemorrhage from varices of an interposed jejunum after choledochojejunostomy treated successfully by endoscopic injection using α-cyanoacrylate monomer]

A 73-year-old woman was admitted with gastrointestinal bleeding. She had undergone pylorus-preserving pancreaticoduodenectomy, hepaticojejunostomy and pancreatojejunostomy for pancreatic cancer a year earlier. Gastrointestinal endoscopy revealed bleeding from varices in an interposed jejunum. Enhanced CT showed an extrahepatic portal venous obstruction and cavernous transformation of the portal vein, which were complications of these operations. We performed endoscopic injection using α-cyanoacrylate monomer for the varices. After 4 treatments, the bleeding stopped. We concluded that endoscopic injection using α-cyanoacrylate monomer was effective and useful treatment for bleeding from hepatopetal varices, including cavernous transformation of the portal vein. This method is also useful in emergency situations.

Molecular analysis of Clostridium difficile at a university teaching hospital in Japan: a shift in the predominant type over a five-year period

Clostridium difficile isolates recovered from patients admitted to a teaching hospital in Japan over a 5-year period were analyzed. Two molecular typing systems, PCR ribotyping and pulsed-field gel electrophoresis (PFGE) analysis, were used. Twenty-six PCR ribotypes were found among the 148 isolates. The predominant type at our hospital appeared to shift during the study period, from PCR ribotype a in 2000 (15/33, 45%) to PCR ribotype f in 2004 (18/28, 64%). By using PFGE with thiourea added to both the gel and running buffer, all 148 Clostridium difficile isolates were successfully classified into 37 types and 61 subtypes. The PCR ribotype f isolates were further classified into four types and 11 subtypes by PFGE. The PFGE patterns of the 11 subtypes differed from each other by only 1 to 4 bands, suggesting that these differences might reflect genetic changes during patient-to-patient transmission over the 5-year period analyzed, and that PCR ribotype f isolates might be outbreak-related. In addition, the PCR ribotype f was identical to the PCR ribotype designated smz, which is reported to have caused multiple outbreaks in Japan. These results confirmed that PCR ribotype f (type smz) has specific virulence or survival factors that make it more likely to cause nosocomial outbreaks at Japanese hospitals. PCR ribotype 027, which has been reported to have caused recent outbreaks in North America and Europe, was recovered from one patient in this study; however, this strain was community-acquired. Our findings emphasize the importance of monitoring specific strains to control and prevent nosocomial infection.

Clinical epidemiology of ciprofloxacin-resistant Proteus mirabilis isolated from urine samples of hospitalised patients

This study investigated the clinical characteristics of ciprofloxacin-resistant Proteus mirabilis isolates from urine samples associated with nosocomial infection or colonisation, and identified the risk-factors for ciprofloxacin resistance. Data for patients with ciprofloxacin-resistant P. mirabilis isolates (n=13) were compared with those for randomly selected patients with ciprofloxacin-susceptible P. mirabilis isolates (n=40) who were matched by temporal occurrence as control patients. The majority of ciprofloxacin-resistant P. mirabilis isolates were multiresistant, and ciprofloxacin resistance was associated significantly with previous use of fluoroquinolones and production of extended-spectrum beta-lactamases.

Interference of Long-Distance Movement of Grapevine berry inner necrosis virus in Transgenic Plants Expressing a Defective Movement Protein of Apple chlorotic leaf spot virus

ABSTRACT Transgenic Nicotiana occidentalis plants expressing a movement protein (P50) and partially functional deletion mutants (DeltaA and DeltaC) of the Apple chlorotic leaf spot virus (ACLSV) showed resistance to Grapevine berry inner necrosis virus (GINV). The resistance is highly effective and GINV was below the level of detection in both inoculated and uninoculated upper leaves. In contrast, GINV accumulated in inoculated and uninoculated leaves of nontransgenic (NT) plants and transgenic plants expressing a dysfunctional mutant (DeltaG). On the other hand, in some plants of a transgenic plant line expressing a deletion mutant (DeltaA', deletion of the C-terminal 42 amino acids), GINV could spread in inoculated leaves, but not move into uninoculated leaves. In a tissue blot hybridization analysis of DeltaA'-plants inoculated with GINV, virus could be detected in leaf blade, midribs, and petiole of inoculated leaves, but neither in stems immediately above inoculated leaves nor in any tissues of uninoculated leaves. Immunohistochemical analysis of GINV-inoculated leaves of DeltaA'-plants showed that GINV could invade into phloem parenchyma cells through bundle sheath of minor veins, suggesting that the long-distance transport of GINV might be inhibited between the phloem cells and sieve element (and/or within sieve element) rather than bundle sheath-phloem interfaces. Immunogold electron microscopy using an anti-P50 antiserum showed that P50 accumulated on the parietal layer of sieve elements and on sieve plates. The results suggested that resistance in P50-transgenic plants to GINV is due to the interference of both long-distance and cell-to-cell movement of the virus.

Enhancement of the specific growth rate of Thiobacillus ferrooxidans by diatomaceous earth

Diatomaceous earth is an effective carrier with a large surface area on which Thiobacillus ferrooxidans adsorbs, and enhances the oxidation rate of ferrous ions by the bacterium. The adsorption of T. ferrooxidans on diatomaceous earth was expressed by the Henry isotherm, and reached equilibrium within five minutes. The enhancement was due to an increase in the growth rate of the adsorbed cells, which were so active that their specific growth rate calculated using a Monod-type equation was higher than that of the free cells in the liquid phase.

[The subjects of the controversy of energy theory and the concept of "labor intensity" in labor physiology from the 1930's to 1950's in Japan. (1) Energy theory and methodology]

An analysis of the subjects of the controversy of energy theory, which was discussed over the various fields of labor science at 1930s-50s in Japan is as follows: (1) This theory was to re-arrange rationally, work in order to reduce the consumption of energy in human actions. It, moreover, was considered to be the standard of the wage adjustment. (2) It became popular since the working powers were terribly wasted by the industrial mobilization during WWII, and when the starvation wages spread throughout the country after the defeat. (3) This theory played an important role to synthesize the academic achievements of various fields such as labor economic, labor physiology, labor psychology and others.

[The subjects of the controversy of energy theory and the concept of "labor intensity" in labor physiology from the 1930's to 1950's in Japan. Part 2: Physiological "labor intensity" and methodology in labor science]

I analyzed the controversy and concept of "labor intensity" in labor physiology, and my opinion is as follows: 1) The energy theory, which measured the human actions with the consumption of energy, considered only the physiological concept of labor intensity, without acknowledging the other aspects of the human being such as the psychological phenomenons, etc. It was one of the views to consider the human and the machine as the same thing. 2) Another theory, which criticizes the energy theory and its connection to energical "labor intensity", was proposed by Utsumi in 1950's and Teruoka (1947-51). 3) I emphasize that we must pay more attention to the methodology when we study the work loads and work conditions, not only by the physiological and psychological methods but also by the socio-economical methods.

Pleuropericarditis and disseminated intravascular coagulation in ulcerative colitis

We report a 30-year-old woman with pleuropericarditis, cardiac tamponade, and disseminated intravascular coagulation complicating active ulcerative colitis (UC). Other autoimmune diseases were not present. She responded to pulsed steroid therapy and anticoagulant with resolution of the complication and UC. We reviewed the literature and found 27 cases of pleuropericarditis associated with idiopathic inflammatory bowel disease (IBD). It has been reported that pleuropericarditis associated with IBD responds well to nonsteroidal antiinflammatory drugs, as well as steroids. The causes of cardiac involvement in IBD remain unclear, but the pleuropericarditis must be recognized as a potential extraintestinal manifestation of IBD.

The complete DNA sequence of the O antigen gene region of Plesiomonas shigelloides serotype O17 which is identical to Shigella sonnei form I antigen

We cloned and determined the sequence of a DNA region of approximately 15-kb containing the cluster of genes required for O17 antigen expression in the Escherichia coli K-12 strain from the chromosome of Plesiomonas shigelloides serotype O17:H2 strain. The sequencing analysis revealed that the minimum essential region of the P. shigelloides O17 antigen gene cluster had a size of approximately 11.5-kb and contained 9 contiguous open reading frames (ORFs), which were almost identical to the corresponding ORFs of Shigella sonnei form I antigen gene region, except for IS630 sequence, at the DNA as well as amino acid levels. The putative function of most of the ORFs could be determined on the basis of amino acid sequence similarities and characteristics. In addition, the G+C content of the P. shigelloides O17 antigen genes was lower than that of the chromosomal DNA of P. shigelloides and S. sonnei, suggesting that both P. shigelloides O17 and S. sonnei form I antigen genes had been derived from the same origin with a low G+C content.

Molecular typing of methicillin-resistant Staphylococcus aureus in a university teaching hospital

Plasmid analysis and pulsed-field gel electrophoresis (PFGE) were used to study the epidemiologic relationship among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated at Tokyo Medical and Dental University Hospital. We found that 263 of 276 MRSA isolates had plasmids, which could be classified into 30 different patterns according to the number and plasmid molecular weight. Strains which harboured a single plasmid of approximately 13.4 Mds in molecular weight were the most numerous (55.7% of the isolates). These strains were isolated from 14 of 17 hospital wards. The largest number of strains with this plasmid pattern (33 strains) were isolated from a single ward. PFGE typing was then performed to further confirm the relationships among these 33 strains. The PFGE banding patterns of these strains were highly similar. The antibiogram profiles of these strains were also correlated with the PFGE pattern. Thus, the results suggest that these strains are epidemiologically related and spread throughout the ward. Combined plasmid analysis and PFGE were effective for discriminating the various MRSA isolates.

Occurrence of toxicity and cell proliferation after a single gavage administration of chloroform to male F344 rats

Chloroform, an industrial solvent and one of the most common environmental contaminants which produces carcinogenic effects in the liver and kidney of rodents, is not genotoxic in most traditional bacterial and mammalian test systems. Its carcinogenic potential appears attributable to the sustained cell turnover (regenerative hyperplasia) which results from chronic chloroform toxicity. In this present study, cell proliferation (replicative DNA synthesis, RDS) and histopathological changes in hepatocytes and renal tubular epithelial cells were assessed in male F344 rats following a single gavage chloroform exposure (50, 150 or 500 mg/kg). In addition, biochemical parameters (BUN, GOT, LDH and NAG) were examined using plasma and urine samples. Cell proliferation and histopathological changes (e.g. hypertrophy, necrosis, vacuolation) were only seen at the dose of 500 mg/kg in the liver and kidney. At the same dose, all biochemical markers were increased at the 24 to 48 hr time points. These results obtained are thus in line with earlier findings pointing to epigenetic carcinogenicity.

Light and electron microscopy of stage-specific features of the transdifferentiation of mouse Meckel's cartilage chondrocytes in vitro

The changes in the morphological characteristics of Meckel's cartilage cells in culture can be divided into five stages during their transdifferentiation to cells with an osteocyte-like phenotype, as demonstrated in this study by light and electron microscopy. Chondrocytes were isolated from day-17 embryonic mice by enzymatic digestion and inoculated at a density of 1 x 10(4) cells. The cultures were incubated at 37 degrees C and cells were harvested every week for 4 weeks and processed for light and electron microscopy, as well as an immunohistochemical analysis of type I and II collagens. The primary cultures were characterized by fibroblastic cells (stage 1) around days 2-4. Polygonal cells (stage 2) expanded on a poorly formed extracellular matrix on day 7, and then they differentiated into large, round cells (stage 3) which began to form cellular nodules. The large, round cells contained many vacuoles, which were rapidly released into the pericellular space with a significant resultant decrease in cell size. Immunostaining showed that the extracellular matrix was occupied predominantly by type II collagen after 2 weeks in culture. However, the type II collagen was gradually replaced by type 1 collagen. Cells that formed multiple layers gradually changed into small, round cells (stage 4) at the tops of nodules and ultimately expressed an osteocytic phenotype (stage 5) after further transdifferentiation.

Early postoperative evaluation of pylorus-preserving gastrectomy for gastric cancer

Early postoperative evaluation was prospectively performed in 35 gastric cancer patients after pylorus-preserving gastrectomy (PPG) between 1989 and 1991, comparing the results with those of 29 patients who underwent conventional distal gastrectomy (CDG). Surgical stress, including the duration of operation (149.0 +/- 4.3 minutes) and the total volume of bleeding at operation (97.0 +/- 11.2 g), was significantly less in the PPG patients. Early postoperative complications were seen in 31% after PPG and in 35% after CDG. The most frequent complication in PPG patients was remnant gastric stasis (23%). Endoscopy showed redness or erosion (or both) of the gastric remnant in 17% after PPG and in 81% after CDG. Bile regurgitation was demonstrated in 11% after PPG and in 62% after CDG. In PPG patients, the pyloric ring opened and closed during the examination. Gastric pH was 4.2 +/- 0.4 in PPG patients but was significantly lower in CDG patients. The resting gallbladder area, examined by ultrasonography, demonstrated no changes after PPG but was significantly enlarged after CDG (from 11.3 +/- 1.2 cm2 to 15.8 +/- 1.5 cm2 at 2 weeks). The percentage of the original resting gallbladder area at 20 minutes after injection of cerulein increased slightly in PPG patients but recovered thereafter, whereas in CDG patients it increased significantly (from 39.4 +/- 8.3% to 66.7 +/- 9.1% at 2 weeks). No gallstone formation was detected throughout the observation period after PPG, whereas after CDG it was detected in two patients at 1 year.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of DU-6859a, a new potent fluoroquinolone, on fecal microflora in human volunteers

Following the oral administration of DU-6859a to six healthy male volunteers at 100 mg per dose three times a day for seven consecutive days, the degree of disturbances of fecal microflora and fecal drug concentrations were examined. The total viable count decreased transiently during the administration due to changes in the number of members of the family Bacteroidaceae, the most predominant organisms. The other obligate anaerobes and most aerobes including facultative anaerobes were suppressed markedly by DU-6859a, with an exception of yeasts. Members of the family Enterobacteriaceae and most of anaerobic bacteria were reduced to below the detection limit in all subjects from the 3rd day of administration period to one day after the discontinuation of the drug. Clostridium difficile was detected in one of the volunteers at the end of administration. Side effects, such as mild transient soft stool and mild transient diarrhoea, were observed in five and one volunteers, respectively. During the administration, DU-6859a was detected in feces at high concentrations which correlated well with the decrease of susceptible members of fecal flora as well as their detection rate.

Recurrent death among early gastric cancer patients: 20-years' experience

Six hundred and ninety-six patients, from among a total of 1,868 cases, were diagnosed as having gastric cancer, and underwent surgical treatment at this Medical Institution, between 1972 and 1992. Eighteen patients (2.6%) died of recurrent disease, four (0.6%) tumors being mucosal, and fourteen (2.0%) submucosal, in accordance with depth of invasion. The clinico-pathological findings were analysed to clarify the risk factors of recurrence in patients with early gastric cancer, as follows: (a) submucosal invasion, (b) mixed type IIa+IIc in gross appearance, (c) tumor size more than 40 mm in diameter. In mucosal cancers, recurrence occurred in patients with lymph-vessel invasion and lymph-node metastasis. In terms of the site of the recurrent lesion, the patients had predominantly hepatic recurrence. We conclude that there are specific factors related to the increased risk of recurrence, that can be evaluated pre-operatively. By identifying the risk factors of recurrence, we can optimize the therapeutic approach to these patients.

[A study on stressful life events of workers in Japan]

The experience rates of eighteen life events of Japanese workers were surveyed and the strength of each of the events was evaluated by a self-reported questionnaire. The fifteen professions surveyed included construction, transport, mailing, chemical production, banking, newspaper, TV services, commercial publishing, advertising, teaching and civil service. The number of workers who answered was 18,657 males and 4,443 females, aged 20 to 59 years. The male workers were divided and analysed in six job groups: clerical workers (n = 5,866), professionals (n = 3,696), blue collar day workers (n = 1,623), blue collar night or shift workers (n = 3,191), drivers (n = 1,663) and construction workers (n = 2,466). They were divided into groups and compared according to job, sex and five different age groups. The highest experience rate in each of the life events such as family trouble for both sexes, death of a family member, financial trouble and anxiety, death of a close friend, dissatisfactory transport to workplace or job, respectively. Comparing the experience rates between males and females we found no significant difference for five items. However, other items had higher experience rates for males than for females with the exception of family trouble. In regard to the age characteristics of each of the life events, as the age increased the experience rates of health-related life events such as the death of a spouse, child, family member or close friend and one's own illness or injury became higher. In contrast, the experience rates of items such as moving to a worse residence and failure in a school or training program became lower as the age increased for both sexes. Among job groups, construction workers had the highest experience rates of most life events except for the item of dissatisfactory transport to the workplace or job. Among other job groups, drivers had higher experience rates in the following four items: re-employment, death of spouse, divorce and financial trouble and anxiety. Blue collar day workers had higher rates for failure in school or training program and family trouble. The blue collar night or shift workers had higher rates for failure in school or training program and dissatisfactory transport to the workplace or job. The mean values of strength in six life events: re-employment, death of a family member, death of a close friend, serious physical illness, dissatisfactory transport to the workplace or job and family trouble were stronger in females than in males.(ABSTRACT TRUNCATED AT 400 WORDS)

[Mental health and its related factors among middle-aged male workers: an eighteen-month follow-up study]

Based on a longitudinal questionnaire survey of 11,121 subjects (males aged 30-59, engaged in various occupations and firms), this study examined the relationships of the baseline psychosocial work environment and personal health practices to mental disorders which occurred during an 18-month follow-up period. The onset of mental disorders during the follow-up period was assumed to be the time when the subject reported to have received medical treatment for the first time due to mental disorder. The psychosocial factors of the work environment were conceptually constructed from two aspects of working conditions and occupational stress. Working conditions were assessed by actual working hours, frequencies of late night work (10 p.m.-5 a.m.), and role in the organization. Occupational stress was measured by psychological work overload and job characteristics (job demands, decision latitude). Various factors associated with positive health behavior were examined through an index based on six variables, that is, supper time, exercise, smoking, alcohol consumption, sleep and weight. Multiple logistic analysis showed that both psychological work overload and late night work have a significant independent effect on the onset of mental disorders after controlling for other variables.

Mucinous cystic tumor of the retroperitoneum. A report of two cases

Two cases of retroperitoneal mucinous cystic tumors and some diagnostic problems on aspiration cytology are presented. The first was a mixed benign, borderline and malignant mucinous tumor, and the second was a mixed benign and borderline mucinous tumor. Our knowledge of the cytology of ovarian mucinous cystic tumors was not helpful in making a correct diagnosis in these cases. Based on our experience, we emphasize the following. First, consider methods of collecting enough cells to make a diagnosis. Second, consider the possibility of mixed histologic features. Direct aspiration, if possible, from papillary lesions inside the cyst will probably lead to an accurate diagnosis. Measurement of carcinoembryonic antigen levels in the cystic fluid is useful in checking for underdiagnosis of such tumors.

[Characteristics of the Shigella flexneri strains isolated from Japanese monkeys (Macaca fuscata)]

Shigella flexneri was isolated from 11 of 95 Japanese monkeys (Macaca fuscata) purchased by the Animal Research Center, Tokyo Medical and Dental University, during the period from 1988 through 1990. The serotypes of the isolates were 4a (5 isolates), 2a (4 isolates), 2b (1 isolate), and varY (1 isolate). Although some of the strains in the same serotypes were similar, others were different in their antibiotic susceptibility patterns or the plasmid profiles. Our results suggested that various types of Shigella flexneri had infected the Japanese monkeys. However, the source(s) and the routes of infection were unclear. Dysentery in the Japanese monkey has not yet been reported. So, to our knowledge, this may be the first report of dysentery among Japanese monkeys.

Chemical analysis of lipopolysaccharides of Shigella sonnei form II strains expressed by cloned form I antigen genes

A compositional sugar analysis was carried out on lipopolysaccharide (LPS) from Shigella sonnei form II in which a plasmid with cloned form I antigen genes had been introduced. The recipient form II strains contained galactose, glucose, heptose, glucosamine, and 2-keto-3-deoxyoctonic acid (KDO) (2: 3: 1: 2: 2) in its LPS, while the transformant form I LPS contained, besides these sugars, N-acetyl-L-altrosaminouronic acid as an additional sugar constituent, which is known to be one of the antigenic determinants of form I antigen.