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A 64-year-old man was admitted to our hospital to undergo examination of a pancreatic tumor accompanied by sudden epigastric pain. The tumor had a well-defined oval shape that was mostly less enhanced, with the exception of part of the tumor on the pancreatic head side, on contrast enhanced (CE)-CT. However, CE-CT performed one-month later revealed that the viable part of the tumor grew toward the pancreatic tail with the reduction of necrotic tissue. We performed distal pancreatectomy and the tumor was diagnosed as acinar cell carcinoma (ACC). One important characteristic of ACC is that it may develop morphological changes within a short period of time.

Objective Rapid cycling (RC) presents a risk of greater severity in bipolar disorder (BD), whereas patients with one-year euthymia (OYE) have better prognosis. The purpose of this study was to identify the clinical background and prescription characteristics of patients in the two opposing states of current RC and OYE from a large sample (N = 2609) in a multicenter treatment survey on BD in psychiatric clinics (MUSUBI). Methods MUSIBI was a cross-sectional study wherein questionnaires, based on a retrospective medical record survey of consecutive cases of BD, were distributed to 176 outpatient clinics. The questionnaire collected information on patient background, current episode, and clinical and prescription characteristics. OYE was defined as the presence of a euthymic state for at least 12 months. Results In this study, current RC (9.7% frequency) was significantly higher in females, had a younger age of onset, functional impairments, and a higher rate of neurodevelopmental disorder and physical comorbidity compared to non-RC patients. OYE (19.4% frequency) was associated with a lower proportion of females, older age, higher occupational status, and lower rate of suicide ideation, psychotic symptoms, personality disorder, and alcohol or substance abuse. Mood stabilizers were prescribed in ≥80% of cases, while antipsychotics were prescribed in half of the cases (more in RC and less in OYE). Antidepressant prescription rates were lower in OYE than in RC. Conclusions RC and OYE generally show opposing characteristics, but the details of the opposite parameters are distinctive. Clinicians can help predict the progression of BD by understanding the clinical background and characteristics of these opposing clinical features.

Objective : Several evidence-based practice guidelines have been developed to better treat bipolar disorder. However, the articles cited in these guidelines were based on clinical or basic studies with specific conditional settings and were not sufficiently based on real-world clinical practice. In particular, there was little information on the doses of mood stabilizers. Methods The MUlticenter treatment SUrvey on BIpolar disorder in Japanese psychiatric clinics (MUSUBI) is a study conducted to accumulate evidence on the real-world practical treatment of bipolar disorder. The questionnaire included patient characteristics such as comorbidities, mental status, treatment period, Global Assessment of Functioning (GAF) score, and details of pharmacological treatment. Results Most patients received mood stabilizers such as lithium (n = 1,317), valproic acid (n = 808), carbamazepine (n = 136), and lamotrigine (n = 665). The dose of lithium was correlated with age, body weight, number of episodes, depression and GAF. The dose of valproic acid was correlated with body weight, number of episodes, presence of a rapid cycle and GAF. The dose of carbamazepine was correlated with age, mania, and the presence of a rapid cycle. The dose of lamotrigine was correlated with the number of episodes, depression, mania, psychotic features, and the presence of a rapid cycle. Doses of coadministered mood stabilizers were significantly correlated, except for the combination of valproic acid and lamotrigine. Conclusion The dose of mood stabilizers was selectively administered based on several factors, such as age, body composition, current mood status and functioning. Further prospective studies are required to confirm these findings.

Background To provide updates on clinical practice of acute pancreatitis (AP) in Japan, we conducted a nationwide epidemiological survey. Methods This study consisted of a two-staged survey; the number of AP patients was estimated by the first-stage survey and their clinical features were examined by the second-stage survey. We surveyed AP patients who had visited hospitals in 2016. Results The estimated number of AP patients in 2016 was 78,450, with an overall incidence of 61.8 per 100,000 persons. We obtained detailed clinical information of 2994 AP patients, including 706 (23.6%) severe cases classified according to the Japanese severity criteria. The male-to-female sex ratio was 2.0, and the mean age at onset was 59.9 years in males and 66.5 years in females. Alcohol was the most common etiology (42.8%) in males and gallstones in females (37.7%). The AP-associated mortality was 6.1% in severe AP cases, which was decreased by 40% compared to the 2011 survey. Antibiotics were administered to most cases, with carbapenem being frequently used. Enteral nutrition was given in 31.8% of severe cases, but majority cases received after 48 h. Among the 107 patients who received intervention for walled-off necrosis, five patients received surgery-first approach, 66 received endoscopic ultrasound-guided transluminal drainage, and 19 underwent step-up approach. Conclusions We clarified the current status of AP in Japan including the significant reduction of mortality in severe cases, shift to endoscopic approaches for walled-off necrosis, and poor compliance of the recommendations in the guidelines including management of enteral nutrition and antibiotic administration.

Takashi Tsuboi,1,2 Takefumi Suzuki,2,3 Takaharu Azekawa,4 Naoto Adachi,4 Hitoshi Ueda,4 Kouji Edagawa,4 Eiichi Katsumoto,4 Yukihisa Kubota,4 Eiichiro Goto,4 Seiji Hongo,4 Yoichiro Watanabe,4 Masaki Kato,2,5 Norio Yasui-Furukori,2,6 Reiji Yoshimura,2,7 Atsuo Nakagawa,2,8 Toshiaki Kikuchi,2,8 Koichiro Watanabe1,2 1Department of Neuropsychiatry, Kyorin University School of Medicine, Tokyo, Japan; 2The Japanese Society of Clinical Neuropsychopharmacology, Tokyo, Japan; 3Department of Neuropsychiatry, University of Yamanashi Faculty of Medicine, Yamanashi, Japan; 4The Japanese Association of Neuro-Psychiatric Clinics, Tokyo, Japan; 5Department of Neuropsychiatry, Kansai Medical University, Osaka, Japan; 6Department of Psychiatry, Dokkyo Medical University, Tochigi, Japan; 7Department of Psychiatry, University of Occupational and Environmental Health, Fukuoka, Japan; 8Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, JapanCorrespondence: Takashi TsuboiDepartment of Neuropsychiatry, Kyorin University School of Medicine, 6-20-2, Shinkawa, Mitaka-Shi, Tokyo 181-8611, JapanTel +81 422 47 5511Fax +81 422 45 4697Email takashi.tsuboi.0821@gmail.comPurpose: The aim of this study was to identify factors associated with non-remission in bipolar disorder.Patients and Methods: The multicenter treatment survey for bipolar disorder in psychiatric outpatient clinics (MUSUBI) study used a questionnaire administered at 176 clinics throughout Japan from September to October 2016. Clinic psychiatrists performed a retrospective medical record survey of consecutive cases with bipolar disorder. Patients were considered to be in remission if they met all of the following criteria: they were not in a mixed state, their manic or depressive symptoms were either borderline or nonexistent (corresponding to 2 or 1 points on the Clinical Global Impressions Scale, Bipolar Version), and their psychiatrists clinically considered them to be in remission. Enrolled patients were classified into remitters group and non-remitters group and demographic and clinical characteristics were contrasted between the groups. Non-remitters were compared with remitters, using a series of logistic regression analyses.Results: A total of 3130 patients (1420 men; mean age: 50.3 years) were included in this study; 1307 patients (41.8%) were in remission. Of the remaining 1823 patients, 1260 (40.3%) had mild to severe depression, 261 (8.3%) suffered from manic or hypomanic episodes, and 302 (9.6%) were in a mixed state. Logistic regression analyses found the following eight factors to be significantly correlated with non-remission in patients with bipolar disorder: female gender, younger age, unemployed status, rapid cycling pattern, comorbid alcohol/substance abuse, poorer social function, lithium non-use, and antidepressant use.Conclusion: The MUSUBI study, the largest nationwide investigation on bipolar disorder, identified eight clinically relevant factors associated with non-remission in bipolar patients. They have important clinical implications; further prospective studies are necessary to replicate these findings and to guide better managements for those in serious needs.Keywords: bipolar disorder, non-remission, nationwide study, mood stabilizer, antipsychotics

Pancreatic ductal adenocarcinoma (PDAC), which accounts for majority of pancreatic cancers, is one of the most lethal human malignancies. Most patients are diagnosed at an advanced stage after symptom development. Early diagnosis of PDAC in asymptomatic subjects is important to improve prognosis. Diabetes mellitus (DM) is a risk factor for PDAC, and DM, especially new-onset DM, has attracted attentions as a diagnostic clue to PDAC. However, the impact of DM as a diagnostic opportunity on the prognosis of PDAC is unclear. We here retrospectively reviewed 489 PDAC patients and compared the clinical characteristics and prognosis according to the opportunities for PDAC diagnosis. PDAC was diagnosed upon presentation of symptoms, such as pain and jaundice, in 318 cases including 151 DM patients, upon new-onset or exacerbation of long-standing DM in 53 asymptomatic patients, and upon incidental detection by medical check-up or follow-up/work-up of other diseases in 118 asymptomatic patients. Asymptomatic patients including those with DM had smaller tumors, earlier disease stage, and higher resectability rates than symptomatic patients. Asymptomatic patients diagnosed in association with DM had better prognosis (median survival time, 771 days) than those diagnosed due to symptoms (343 days, P < 0.001), and similar to those diagnosed by incidental detection (869 days). The survival advantage was not evident in symptomatic patients with DM-associated signs. In conclusion, patients diagnosed in association with DM at asymptomatic stages had better prognosis than those diagnosed with symptoms. DM-associated signs might provide a clue to the early diagnosis of PDAC among asymptomatic subjects.

Influenza C virus (ICV) has only one kind of spike protein, the hemagglutinin-esterase (HE) glycoprotein. HE functions similarly to hemagglutinin (HA) and neuraminidase of the influenza A and B viruses (IAV and IBV, respectively). It has a monobasic site, which is cleaved by some host enzymes. The cleavage is essential to activating the virus, but the enzyme or enzymes in the respiratory tract have not been identified. This study investigated whether the host serine proteases, transmembrane protease serine S1 member 2 (TMPRSS2) and human airway trypsin-like protease (HAT), which reportedly cleave HA of IAV/IBV, are involved in HE cleavage. We established TMPRSS2- and HAT-expressing MDCK cells (MDCK-TMPRSS2 and MDCK-HAT). ICV showed multicycle replication with HE cleavage without trypsin in MDCK-TMPRSS2 cells as well as IAV did. The HE cleavage and multicycle replication did not appear in MDCK-HAT cells infected with ICV without trypsin, while HA cleavage and multistep growth of IAV appeared in the cells. Amino acid sequences of the HE cleavage site in 352 ICV strains were completely preserved. Camostat and nafamostat suppressed the growth of ICV and IAV in human nasal surface epithelial (HNE) cells. Therefore, this study revealed that, at least, TMPRSS2 is involved in HE cleavage and suggested that nafamostat could be a candidate for therapeutic drugs for ICV infection. IMPORTANCE Influenza C virus (ICV) is a pathogen that causes acute respiratory illness, mostly in children, but there are no anti-ICV drugs. ICV has only one kind of spike protein, the hemagglutinin-esterase (HE) glycoprotein on the virion surface, which possesses receptor-binding, receptor-destroying, and membrane fusion activities. The HE cleavage is essential for the virus to be activated, but the enzyme or enzymes in the respiratory tract have not been identified. This study revealed that transmembrane protease serine S1 member 2 (TMPRSS2), and not human airway trypsin-like protease (HAT), is involved in HE cleavage. This is a novel study on the host enzymes involved in HE cleavage, and the result suggests that the host enzymes, such as TMPRSS2, may be a target for therapeutic drugs of ICV infection.

Purpose. To clarify the spread of Mycoplasma pneumoniae infections in semi-closed settings such as schools and family homes using molecular typing methods. Methodology. We retrospectively searched for school- and family-based clusters of M. pneumoniae infections based on information regarding patients from whom M. pneumoniae strains had been isolated between 2011 and 2013 in Yamagata, Japan. The molecular typing profile, including the P1 type and the four-locus (Mpn13, 14, 15 and 16) multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) type, was obtained from our previous study. Results. We identified 11 school-based clusters involving 71 patients and 16 family-based clusters involving 38 patients, including 14 duplications between these types of clusters. A total of 95 M. pneumoniae strains isolated from those patients were divided into 4 genotypes: 33 strains of type 4-5-7-2, 1; 31 of type 4-5-7-3, 1; 24 of type 3-5-6-2, 2c; and 7 of type 3-5-6-2, 2a. Of the 11 school-based clusters, 6 clusters (54.5%) consisted of multiple genotypes, and the remaining 5 clusters consisted of a single genotype. Moreover, the presence of multiple genotypes was identified in three classrooms of a school. On the other hand, in 14 (87.5%) of the 16 family-based clusters, the genotypes of the M. pneumoniae strains isolated from each family member were identical. Conclusion. The spread of M. pneumoniae infection in schools is likely polyclonal, since M. pneumoniae strains are brought into schools from various sites, such as family homes, which are important sites of disease transmission.

A 79-year-old woman was referred for pancreatic tail cancer with multiple liver metastases. The pancreatic tail tumor was diagnosed as acinar cell carcinoma (ACC) histologically by endoscopic ultrasound-guided fine-needle aspiration. Because of multiple liver metastases, S-1 chemotherapy was administered, resulting in a partial response to chemotherapy one year later. After approximately three years, liver atrophy and esophageal varices developed. We suspected S-1 as the cause of the liver cirrhosis. S-1 cessation minimized ascites and improved the esophageal varices. Although S-1 can potentially treat ACC, we should be watchful for liver cirrhosis caused by its long-term administration.

Yusuke Konno,1,2 Yoshihisa Fujino,2 Atsuko Ikenouchi,1,3 Naoto Adachi,4 Yukihisa Kubota,4 Takaharu Azekawa,4 Hitoshi Ueda,4 Koji Edagawa,4 Eiichi Katsumoto,4 Eiichiro Goto,4 Seiji Hongo,4 Masaki Kato,5,6 Takashi Tsuboi,5,7 Norio Yasui-Furukori,5,8 Atsuo Nakagawa,5,9 Toshiaki Kikuchi,5,9 Koichiro Watanabe,5,7 Reiji Yoshimura1,5 1Department of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Japan; 2Department of Environmental Epidemiology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan; 3Medical Center for Dementia, University Hospital of Occupational and Environmental Health, Kitakyushu, Japan; 4The Japanese Association of Neuro-Psychiatric Clinics, Tokyo, Japan; 5The Japanese Society of Clinical Neuropsychopharmacology, Tokyo, Japan; 6Department of Neuropsychiatry, Kansai Medical University, Osaka, Japan; 7Department of Neuropsychiatry, Kyorin University School of Medicine, Tokyo, Japan; 8Department of Psychiatry, Dokkyo Medical University, Tochigi, Japan; 9Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, JapanCorrespondence: Yusuke KonnoDepartment of Psychiatry, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishiku, Kitakyushu, 807-8555, JapanTel +81-93-691-7401Fax +81-93-692-4894Email yu-konno@med.uoeh-u.ac.jpObjective: The objective of this study was to clarify the relationship between mood episode and employment in patients with bipolar disorder to help improve their employment status.Methods: All medical records of patients with bipolar disorder who visited 176 member clinics of the Japanese Association of Neuro-Psychiatric Clinics in September–October 2016 were investigated in September–October 2017. Details of the medical care received were investigated using a survey sheet, which included employment status. Odds ratios of mood episodes for employment status were analyzed using a logistic regression model.Results: Among patients aged 60 years or less, 2292 described their occupation. On univariate analysis, odds ratios were statistically significant for depressive episode (OR = 2.68 [1.50– 4.78] p = 0.001) and manic episode (OR = 2.64 [1.07– 6.47] p = 0.034), whereas no significant difference was noted for mixed episode (OR = 1.72 [0.69– 4.33] p = 0.246). On multivariate analysis, odds ratios were statistically significant for depressive episode (OR = 2.16 [1.13– 4.13], p = 0.020) and manic episode (OR = 3.55 [1.36– 9.25], p = 0.010), whereas no significant difference was noted for mixed episode (OR = 1.83 [0.65– 5.14] p = 0.254).Conclusion: Employment status among these patients with bipolar disorder receiving outpatient treatment was 43.5%. Compared to remission episodes, manic and depressive episodes were associated with a higher risk of unemployment.Keywords: mood disorder, continuous employment, occupational health, Japan

A 71-year-old man underwent surgery for a pancreatic neuroendocrine tumor. Follow-up imaging showed swelling of the remnant pancreas, and he was histologically diagnosed with autoimmune pancreatitis based on endoscopic ultrasonography-guided fine-needle aspiration specimens. After two years, a tumor appeared on the liver surface. Although we planned to perform laparoscopic partial hepatectomy, the intraoperative findings showed that the tumor was located in the diaphragm. Partial resection of the diaphragm was performed, and the final diagnosis was an immunoglobulin G4-related inflammatory pseudotumor in the diaphragm. To our knowledge, this is the first reported case of an immunoglobulin G4-related diaphragmatic inflammatory pseudotumor.

Background Several evidence-based practice guidelines have been developed to better treat bipolar disorder. However, the articles cited in these guidelines were not sufficiently based on real-world clinical practice. Methods The MUlticenter treatment SUrvey on BIpolar disorder in Japanese psychiatric clinics (MUSUBI) is a study conducted to accumulate evidence on the real-world practical treatment of bipolar disorder. Psychiatrists were asked to complete a questionnaire about patients with bipolar disorder by performing a retrospective medical record survey. The questionnaire included patient characteristics (age, gender, height, weight, academic background, and occupational status), comorbidities, mental status, treatment period, Global Assessment of Functioning (GAF) score, and details of pharmacological treatment. Results Data on 2705 patients were included in this study. The proportion of patients receiving antidepressant prescriptions was 40.9%. The most commonly used antidepressant was duloxetine, and the most frequently used antidepressant class was selective serotonin reuptake inhibitors (SSRIs). Binomial logistic regression analysis and bivariate analysis revealed that the usage of antidepressants was correlated with low prescription rates for mood stabilizers, high prescription rates for anxiolytics and hypnotics, and low GAF scores. In addition, patients in a depressive state had a significantly higher rate of antidepressant prescriptions than patients with other mental states. Conclusions Approximately 40% of patients in Japan with a diagnosis of bipolar disorder have received antidepressants. Antidepressants were most often prescribed in combination with mood stabilizers, antipsychotics or both. Patients who were prescribed antidepressants received fewer mood stabilizers, more anxiolytics, and more hypnotics than those who did not receive antidepressant prescriptions.

Objective This study aims to clarify the relevant factors influencing practitioners' methods of prescribing medications for bipolar disorder, in a nation-wide survey in Japan. Methods The clinical records of 3130 outpatients with bipolar disorder were consecutively reviewed from 176 psychiatric outpatient clinics. Fifteen parameters, that is, five patients' including five general characteristics (sex, age, education, occupation, and social adjustment), five patients' aspects of mental functioning (onset age, comorbid mental illness, rapid-cycling, psychopathologic severity, and followed-up years), and five practitioners' characteristics (sex, age, specialist experience, clinic standing years, and location), were evaluated. The number of psychotropic drugs (mood stabilizers, antidepressants, antipsychotic drugs, anxiolytics, and hypnotics) was used as an index of pharmacotherapy. Converted data from each practitioner-unit were analyzed. Results Seven factors (patient's social adjustment, patient's psychopathology, patient's comorbid mental disorders, patient's followed-up years, doctor's age, clinic running years, and patient's education years) were correlated to the number of psychotropic drugs. Multiple regression analysis showed that the severity of illness (poor social adjustment, and comorbid mental illness) and an intractable disease course (long followed-up years), were significantly associated with the number of psychotropic drugs. Conclusion Our findings indicated that patient-related conditions affected psychotropic polypharmacy more strongly than did practitioner-related conditions.

Pancreatic cancer is one of the most dangerous solid tumors, but its early diagnosis is difficult. The abnormality of the main pancreatic duct (MPD), such as a single localized stricture and upstream dilatation, might be useful in the early detection of pancreatic cancer. However, these findings are often observed in benign inflammatory cases. This study aimed to clarify whether early pancreatic cancer presenting MPD abnormalities has characteristic features different from those of benign cases. This is a single-center, retrospective study. We analyzed 20 patients who underwent pancreatectomy presenting with a single, localized MPD stricture without identifiable masses on imaging: 10 patients with pancreatic ductal adenocarcinoma (cancer group; 6 with stage 0 and 4 with stage I) and 10 patients with benign strictures (benign group; 8 with inflammation and 2 with low-grade pancreatic intraepithelial neoplasms). Pancreatectomy was performed in these benign cases because high-grade intraepithelial neoplasm was suspected. Although the proportion of patients with diabetes mellitus tended to be higher in the cancer group (6/10) than that in the benign group (1/10) (P = 0.058), other clinical characteristics were not different between the groups. Preoperative cytological malignancies were detected in four patients in the cancer group (4/10) but not in the benign group (P = 0.09). Focal parenchymal atrophy and fat replacement were more frequently detected on computed tomography in the cancer group (7/10) than in the benign group (1/10) (P = 0.02). In conclusion, focal parenchymal atrophy and fat replacement may provide clues for the early diagnosis of pancreatic cancer.

OBJECTIVE There is limited information available on the prescription of psychotropic agents to patients with bipolar I (BD-I) and bipolar II disorder (BD-II). The purpose of this study was to investigate the characteristics of drug therapy in BD-I and BD-II outpatients, particularly with regard to antidepressants. METHODS In 2017, the MUlticenter treatment SUrvey for BIpolar disorder in Japanese psychiatric clinics (MUSUBI) study collected data on current mental status, medications, and other factors from 2774 outpatients with BD-I or BD-II. RESULTS There were significant differences in the rates of prescriptions for mood stabilizers, antipsychotics and antidepressants. Mood stabilizers and antipsychotics were prescribed at higher rates to patients with BD-I (mood stabilizers; BD-I 86.0%, BD-II 80.8%, p

Pancreaticojejunostomy stricture (PJS) is a late complication of pancreaticoduodenectomy. The endoscopic treatment of PJS is very challenging due to the difficulty of locating the small anastomotic site and passing the stricture using a guidewire. We herein report two cases of severe PJS. These patients could not be treated using only double-balloon endoscopy or endoscopic ultrasound-guided puncture of the main pancreatic duct because of severe stenosis at the anastomotic site. However, we could treat them by the rendezvous technique using the rigid part of the guidewire to penetrate PJS. This method was useful and safe for treating severe PJS.

Purpose. To determine the timing of the emergence of macrolide-resistant mutations after macrolide treatment in individuals with Mycoplasma pneumoniae infections. Methodology. Between October 2011 and December 2013, serial pharyngeal swab specimens were collected before and after macrolide treatment from 21 otherwise healthy children infected with M. pneumoniae without macrolide-resistant mutations. The copy numbers of a M. pneumoniae gene and the proportion of clones showing macrolide-resistance mutations were determined for each specimen. Results. After macrolide treatment (10–15 mg kg−1 day−1 clarithromycin for 5–10 days or 10 mg kg−1 day−1 azithromycin for 3 days), fever resolved in 19 (90 %) of 21 children within 1 to 2 days, and the M. pneumoniae gene copy number decreased in all but one specimen in the second set of specimens relative to the number in the corresponding initial specimens. None of the second specimens, which were collected 2–4 days after initiation of macrolide treatment, showed mutations in the 23S rRNA gene. However, the proportion of mutant clones with A2063G and A2064G mutations in the specimens collected 7–24 days after initiation of treatment increased to 100 %. We identified a family in which three members had M. pneumoniae infections. The analysis of transmission in this household indicated that the M. pneumoniae harbouring a macrolide-resistant mutation that developed in the index patient after macrolide treatment was not transmitted to the family members. Conclusion. A macrolide-resistant population might develop in individual patients up to 24 days after initiation of macrolide treatment. However, the decrease in M. pneumoniae load after macrolide administration effectively reduces interpersonal transmission.

Aim: S16, a monoclonal antibody against the hemagglutinin-esterase fusion (HEF) glycoprotein of influenza C virus, reacts with SV40 large T antigen (LT) and a host cellular component(s). The aim is to determine the location of S16 linear epitope on LT and the amino acid sequence of S16 epitope. Materials & methods: BHK-21 cells expressing wild-type and mutant LTs, HEFs or GFPs, each of which was tagged with a FLAG epitope, were analyzed by immunoblotting using S16. Results & conclusions: An amino acid sequence 98-FNEENL-103 on LT forms a linear epitope recognized by S16. The sequence of S16 epitope was defined as F[NAT]EE[NYA]L, excluding FAEEAL and FTEEAL. This finding will be of help in identifying a host cellular component(s) crossreactive with S16.

The antigenicity of the hemagglutinin esterase (HE) glycoprotein of influenza C virus is known to be stable, however, information about residues related to antigenic changes has not yet been fully acquired. Using selection with anti-HE monoclonal antibodies, we previously obtained some escape mutants and identified four antigenic sites, namely, A-1, A-2, A-3, and Y-1. To confirm whether the residues identified as the neutralizing epitope possibly relate to the antigenic drift, we analyzed the growth kinetics of these mutants. The results showed that some viruses with mutations in antigenic site A-1 were able to replicate to titers comparable to that of the wild-type, while others showed reduced titers. The mutants possessing substitutions in the A-2 or A-3 site replicated as efficiently as the wild-type virus. Although the mutant containing a deletion at positions 192 to 195 in the Y-1 site showed lower titers than the wild-type virus, it was confirmed that this region in the 190-loop on the top side of the HE protein is not essential for viral propagation. Then, we revealed that antigenic changes due to substitutions in the A-1, A-3, and/or Y-1 site had occurred in nature in Japan for the past 30 years. These results suggest that some residues (i.e., 125, 176, 192) in the A-1 site, residue 198 in the A-3 site, and residue 190 in the Y-1 site are likely to mediate antigenic drift while maintaining replicative ability.

A 32-year-old woman was referred due to abdominal pain and elevated liver enzymes. Computed tomography and magnetic resonance imaging showed ectopic opening of the common bile duct (CBD) into the duodenal bulb. Esophagogastroduodenoscopy showed a hemispheric bulge in the duodenal bulb. Endoscopic retrograde cholangiopancreatography (ERCP) revealed the bulge to be cystic dilatation of the CBD. ERCP also showed no communication between the ventral and dorsal pancreatic ducts. We diagnosed the patient with ectopic opening of the CBD accompanied by choledochocele and pancreas divisum. Endoscopic incision was performed for the treatment of the choledochocele. The patient's symptoms and elevated liver enzymes improved after treatment.

Tempei Otsubo,1 Yoshinori Watanabe,2,3 Seiji Hongo,3 Mikichika Inoue,4 Kimiko Akimoto,4 Ken Murakami,5 Ryutaro Takahashi,6 Toshiaki Kikuchi7 1Department of Psychiatry, Tokyo Women’s Medical University Medical Center East, Tokyo, Japan; 2Himorogi Psychiatric Institute, Tokyo, Japan; 3Nanko Clinic of Psychiatry, Shirakawa, Japan; 4Ikebukuro Internal Medicine, Tokyo, Japan; 5Murakami Hospital, Tokyo, Japan; 6Takahashi Clinic, Tokyo, Japan; 7Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan Aim: To assess the effectiveness and safety of switching the antidepressant formulation from immediate-release (IR) to controlled-release (CR) paroxetine in patients with major depressive disorder (MDD). Patients and methods: A total of 113 outpatients with MDD diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, and treated with a stable dose of IR paroxetine for at least 6 months were enrolled. Patients were then switched to CR paroxetine for 8 weeks. Effectiveness was evaluated by scores on the Himorogi Self-Rating Depression/Anxiety Scales (HSDS/HSAS) and the Clinical Global Impression – Severity (CGI-S). Safety was evaluated based on the reported adverse drug reactions (ADRs). Medication satisfaction and preference were assessed based on questionnaire responses using Likert-type scales. Results: The overall patient HSDS/HSAS scores significantly improved after switching from IR to CR paroxetine (P

Many broadly neutralizing antibodies (bnAbs) bind to conserved areas of the hemagglutinin (HA) stalk region and can inhibit the low pH induced HA conformational changes necessary for viral membrane fusion activity. We developed and evaluated a high-throughput virus-free and cell-free ELISA based low pH induced HA Conformational Change Inhibition Antibody Detection Assay (HCCIA) and a complementary proteinase susceptibility assay. Human serum samples (n = 150) were tested by HCCIA using H3 recombinant HA. Optical density (OD) ratios of mAb HC31 at pH 4.8 to pH 7.0 ranged from 0.87 to 0.09. Our results demonstrated that low pH induced HA conformational change inhibition antibodies (CCI) neutralized multiple H3 strains after removal of head-binding antibodies. The results suggest that HCCIA can be utilized to detect and characterize CCI in sera, that are potentially broadly neutralizing, and serves as a useful tool for evaluating universal vaccine candidates targeting the HA stalk.

Multiple-locus variable-number tandem-repeat analysis (MLVA) typing was performed for Mycoplasma pneumoniae strains isolated between 2004 and 2014 in Yamagata, Japan. The results were examined by considering the combination of the P1 type and prevalence of macrolide resistance-associated mutations. Four-locus (Mpn13-16) MLVA classified 347 strains into 9 MLVA types, including 3 major types: 3-5-6-2, 4-5-7-2, and 4-5-7-3. All type 3-5-6-2 strains (77 strains) were P1 type 2 variants (2a or 2c), while types 4-5-7-2 (181 strains) and 4-5-7-3 (75 strains) were P1 type 1. MLVA type 4-5-7-2 strains circulated and were dominant until 2010, accounting for 88.4% of the 121 strains isolated between 2004 and 2010. The prevalence of types 4-5-7-3 and 3-5-6-2 strains increased rapidly in 2011 and 2012, respectively, resulting in cocirculation of 3 MLVA types, including type 4-5-7-2, between 2011 and 2013. The prevalence of macrolide resistance-associated mutations in MLVA types 4-5-7-2, 4-5-7-3, and 3-5-6-2 strains was 59.7% (108/181), 25.3% (19/75), and 0% (0/77), respectively. Because the prevalence of macrolide resistance-associated mutations differed by current MLVA types in Yamagata, continued surveillance combined with molecular typing and identification of macrolide resistance-associated mutations is necessary.

CM2 is the second membrane protein of the influenza C virus and has been demonstrated to play a role in the uncoating and genome packaging processes in influenza C virus replication. Although the effects of N-linked glycosylation, disulfide-linked oligomerization, and palmitoylation of CM2 on virus replication have been analyzed, the effect of the phosphorylation of CM2 on virus replication remains to be determined. In this study, a phosphorylation site(s) at residue 78 and/or 103 of CM2 was replaced with an alanine residue(s), and the effects of the loss of phosphorylation on influenza C virus replication were analyzed. No significant differences were observed in the packaging of the reporter gene between influenza C virus-like particles (VLPs) produced from 293T cells expressing wild-type CM2 and those from the cells expressing the CM2 mutants lacking the phosphorylation site(s). Reporter gene expression in HMV-II cells infected with VLPs containing the CM2 mutants was inhibited in comparison with that in cells infected with wild-type VLPs. The virus production of the recombinant influenza C virus possessing CM2 mutants containing a serine-to-alanine change at residue 78 was significantly lower than that of wild-type recombinant influenza C virus. Furthermore, the virus growth of the recombinant viruses possessing CM2 with a serine-to-aspartic acid change at position 78, to mimic constitutive phosphorylation, was virtually identical to that of the wild-type virus. These results suggest that phosphorylation of CM2 plays a role in efficient virus replication, probably through the addition of a negative charge to the Ser78 phosphorylation site. IMPORTANCE It is well-known that many host and viral proteins are posttranslationally modified by phosphorylation, which plays a role in the functions of these proteins. In influenza A and B viruses, phosphorylation of viral proteins NP, M1, NS1, and the nuclear export protein (NEP), which are not integrated into the membranes, affects the functions of these proteins, thereby affecting virus replication. However, it was reported that phosphorylation of the influenza A virus M2 ion channel protein, which is integrated into the membrane, has no effect on virus replication in vitro or in vivo . We previously demonstrated that the influenza C virus CM2 ion channel protein is modified by N-glycosylation, oligomerization, palmitoylation, and phosphorylation and have analyzed the effects of these modifications, except phosphorylation, on virus replication. This is the first report demonstrating that phosphorylation of the influenza C virus CM2 ion channel protein, unlike that of the influenza A virus M2 protein, plays a role in virus replication.

Yoshinori Watanabe,1,2 Seiji Hongo2 1Himorogi Psychiatric Institute, Tokyo, 2Nanko Clinic of Psychiatry, Shirakawa city, Fukushima, Japan Background: We investigated whether the long-term efficacy and safety of lamotrigine (LTG) for bipolar disorder (BP) differs between disease types (BP-I, BP-II, or BP not otherwise specified [BP-NOS]), and the efficacy of the concomitant use of antidepressants (ADs).Methods: For >1 year, we observed 445 outpatients with BP (diagnosed by DSM-IV criteria) who initiated LTG treatment between July 1 and October 31, 2011, using the Himorogi Self-rating Depression (HSDS) and Anxiety Scales and the Clinical Global Impression-Improvement scale and also recorded adverse events.Results: Treatment efficacy was observed at week 4, with the improved HSDS scores sustained until week 52 for all types of BP; 50% of the patients with any type of BP could be treated with LTG for 1 year, whereas ~40% could be treated for >1.5 years. However, 25% of the patients were withdrawn within the first 4 weeks. The overall incidence of adverse events was 22.9% (104/455): 34.1% (14/41) for BP-I, 22.7% (15/66) for BP-II, and 22.2% (75/338) for BP-NOS. The most common adverse event was skin rash: 22.0% for BP-I, 16.7% for BP-II, and 12.1% for BP-NOS.Limitations: There was no control group. Data were collected retrospectively.Conclusion: With careful and adequate titration, long-term treatment with LTG is possible for any type of BP, with BP-NOS patients, the largest population in clinical practice, responding particularly well. Symptoms can improve with or without ADs. Large-scale prospective studies of the efficacy of ADs in bipolar treatment are warranted. Keywords: lamotrigine, bipolar disorder, long-term efficacy, antidepressant, skin rash, anxiety

Objective The study evaluated relationships between frontal lobe function in patients with schizophrenia and both their social adjustment and medication, using 22-channel near-infrared spectroscopy (NIRS). Methods One hundred ninety-nine stable patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision schizophrenia, whose medication had not been changed within the preceding 3 months and who were able to visit our clinics for NIRS, were the study subjects. As a comparator, 144 healthy volunteers who underwent a physical examination and the Mini-International Neuropsychiatric Interview also received NIRS. Results The main outcomes evaluated were frontal lobe oxyhemoglobin concentration (OxHb) measured by NIRS, current medication, social adjustment, and scores on the Brief Psychiatric Rating Scale. The OxHb in schizophrenic patients (0.878 ± 1.1801 mMmm; n = 199) was significantly lower than that in the healthy volunteers (2.085 ± 1.7480 mM mm: n = 100) (p

Enterovirus 71 infections have become a major public issue in the Asia-Pacific region due to the large number of fatal cases. To clarify the longitudinal molecular epidemiology of enterovirus 71 (EV71) in a community, we isolated 240 strains from children, mainly with hand-foot-and-mouth diseases, between 1990 and 2013 in Yamagata, Japan. We carried out a sequence analysis of the VP1 region (891 bp) using 223 isolates and identified six subgenogroups (B2, B4, B5, C1, C2 and C4) during the study period. Subgenogroups C1 and B2 were found only between 1990 and 1993 and have not reappeared since. In contrast, strains in subgenogroups C2, C4 and B5 appeared repeatedly with genomic variations. Recent reports from several local communities in Japan have suggested that identical predominant subgenogroup strains, which have also been found in the Asia-Pacific region, have been circulating in a wide area in Japan. However, it is likely that there is a discrepancy between the major subgenogroups circulating in the Asia-Pacific region and those in Europe. It is necessary to continue the analysis of the longitudinal epidemiology of EV71 in local communities, as well as on regional and global levels, to develop strategies against severe EV71 infections.

The prevalence of macrolide-resistant Mycoplasma pneumoniae harboring a mutation in the 23S rRNA gene is increasing, and rapid detection assays are needed for clinical management. We developed an endpoint genotyping assay to detect the M. pneumoniae 23S rRNA gene and determine the existence of macrolide resistance-associated mutations at position 2063 (A2063G, A2063T and A2063C mutations). This A2063B genotyping assay detected more than 50 copies/reaction of the M. pneumoniae gene in every nucleotide mutation at position 2063. Of 42 clinical specimens, 3 were positive without mutation, 6 were positive with the A2063G mutation, and 33 were negative. The results were confirmed using nested PCR with the sequencing of the M. pneumoniae 23S rRNA gene, and a high sensitivity (90%), specificity (100%), and coincidence ratio (kappa coefficient=0.93) were obtained. Therefore, the A2063B genotyping assay is useful for the rapid discrimination of macrolide resistance mutations at position 2063.

SummaryMeasles among healthcare workers (HCWs) is associated with a significant risk of nosocomial transmission to susceptible patients. When a measles case occurs in the healthcare setting, most guidelines recommend exhaustive measures. To evaluate the effects of measures against measles transmission in the healthcare setting precisely, it is essential to determine whether secondary transmission generally occurs. This study describes, for the first time, the actual secondary transmission rate for a measles-infected HCW in a ward with no special air ventilation capacity. The routine treatment of a number of immunocompromised patients occurs in this ward, and thus patients as well as HCWs have a thorough understanding and practice of standard and extended precautions. Our paired serum sample study revealed that none of the people in the ward exposed to the HCW at the catarrhal stage over a period of 4 days exhibited elevated levels of antibodies against measles. We suggest that strict adherence to standard and expanded precautions among patients and HCWs may be effective for preventing the transmission of a highly airborne disease, such as measles.

The purpose of this study was to evaluate the frequency of human metapneumovirus (hMPV) infection in adults and to determine the association between the levels of serum antibody titers and the susceptibility to reinfection. Serum samples collected at the periodic occupational medical checkup for employees of a hospital were subjected to an ELISA test. Of the 289 subjects, 288 (99.7%) had hMPV antibody titers that were more than 1:100 in May 2006. The percentage of subjects with a titer of ≥ 3,200 was significantly higher in adults aged 40-65 years old (30.2-31.5%) compared to young adults 20-39 years old (13.6%) (P < 0.05). To investigate the longitudinal course of the hMPV antibody titer, a total of 649 serum samples collected from 59 subjects who had participated in all biannual medical checkups between 2001 and 2006 were tested. We found that ten serum pairs showed a greater than fourfold increase in hMPV antibody titers. Additionally, the 5-year reinfection rate was estimated at 16.9% (10 of 59 subjects). The baseline titer before the fourfold increase ranged from 1:100 to 1:3,200, and the titer returned to baseline levels 2 or 3 years after the fourfold increase. The antibody titer of the person with the baseline titer of 1:100 showed a greater than fourfold increase twice within a year. Sixty to 80% of adults had an ELISA titer of 1:800 to 1:1,600, suggesting that such an antibody titer is not enough to protect from hMPV infection and that reinfection could occur among adults.

Reverse genetics has been documented for influenza A, B, and Thogoto viruses belonging to the family Orthomyxoviridae . We report here the reverse genetics of influenza C virus, another member of this family. The seven viral RNA (vRNA) segments of C/Ann Arbor/1/50 were expressed in 293T cells from cloned cDNAs, together with nine influenza C virus proteins. At 48 h posttransfection, the infectious titer of the culture supernatant was determined to be 2.51 × 10 3 50% egg infectious doses/ml, which is lower than the number of influenza C virus-like particles (VLPs) (10 6 /ml) generated using the same system. By generating influenza C VLPs containing a given vRNA segment, we showed that each of the vRNA segments was similarly synthesized in the plasmid-transfected cells but that some segments were less efficiently incorporated into the VLPs. This finding leads us to speculate that the differences in incorporation efficiency into VLPs between segments might be a reason for the inefficient production of infectious viruses. Second, we generated a mutant recombinant virus, rMG96A, which possesses an Ala→Thr mutation at residue 24 of the M1 protein, a substitution demonstrated to be involved in the morphology (filamentous or spherical) of the influenza C VLPs. As expected, rMG96A exhibited a spherical morphology, whereas recombinant wild-type of C/Ann Arbor/1/50, rWT, exhibited a mainly filamentous morphology. Membrane flotation analysis of the cells infected with rWT or rMG96A revealed a difference in the ratio of membrane-associated M1 proteins, suggesting that the affinity of M1 protein to the cell membrane is a determinant for virion morphology.

During the period from January to July 2004, a total of 131 influenza C viruses were detected by cell culture or reverse transcription-PCR (RT-PCR) from specimens that were obtained from children with acute respiratory symptoms in 10 prefectures across Japan. Influenza C virus was identified most frequently in the Miyagi (1.4%, 45 of 3,226 specimens) and Yamagata (2.5%, 31 of 1,263 specimens) prefectures, and the frequency in this year was the highest since 1990. Phylogenetic analysis of the hemagglutinin esterase gene of the 13 strains isolated in nine prefectures revealed that genetically similar strains belonging to the Kanagawa/1/76-related lineage dominantly spread throughout Japan. During the 2004 influenza season, influenza C virus coexisted with epidemics of influenza A virus (H3 strain), and 12 cases were identified from patients who had been diagnosed with influenza-like illness (7 were detected by RT-PCR, and 5 were detected by culture). A comparison of specimens that were found positive by culture with those found positive only by RT-PCR shows that the amount of virus in PCR-positive specimens tended to be lower than in isolation-positive specimens. Although the mean peak temperature in patients in the PCR-positive group was slightly lower, there were no significant differences in characteristics between specimens (i.e., kind of specimen, period from onset to specimen collection, age distribution of patients, and severity of illness). These results suggest that an epidemic of influenza C virus occurred on a national scale during this period and that RT-PCR can be an effective supplemental tool for the evaluation of clinical and epidemiological information.

A 50-year-old male was referred to our hospital for the evaluation of hyperproteinemia. Fluorodeoxyglucose positron emission tomography revealed high fluorodeoxyglucose uptake in the pancreas, bilateral lacrimal glands, submandibular glands, parotid glands, bilateral pulmonary hilar lymph nodes, and kidneys. Laboratory data showed an elevation of hepatobiliary enzymes, renal dysfunction, and remarkably high immunoglobulin (Ig) G levels, without elevated serum IgG4. Abdominal computed tomography revealed swelling of the pancreatic head and bilateral kidneys. Endoscopic retrograde cholangiopancreatography showed an irregular narrowing of the main pancreatic duct in the pancreatic head and stricture of the lower common bile duct. Histological examination by endoscopic ultrasonography-guided fine-needle aspiration revealed findings of lymphoplasmacytic sclerosing pancreatitis without IgG4-positive plasma cells. Abnormal laboratory values and the swelling of several organs were improved by the treatment with steroids. The patient was diagnosed as having type 1 autoimmune pancreatitis (AIP) based on the International Consensus Diagnostic Criteria. Therefore, we encountered a case of compatible type 1 AIP without elevated levels of serum IgG4 or IgG4-positive plasma cells. This case suggests that AIP phenotypes are not always associated with IgG4.

Influenza A/H3N2 viruses have increased the number of glycosylation sites on the head of the hemagglutinin (HA) protein since their appearance in 1968. Here, the effect of the addition of oligosaccharide chains to the HA of the H3N2 virus on its biological activities was investigated. We constructed wild-type HA and six mutant HAs of A/Aichi/2/68 virus with two or one to six glycosylation sites on the head, respectively. The glycosylation sites of mutated HAs correspond to representative H3N2 isolates (A/Victoria/3/75, A/Memphis/6/86 and A/Sydney/5/97). We analyzed their intracellular transport, receptor-binding and cell fusion activities. The results showed that all the mutated HAs were transported to the cell surface, as well as wild-type HA, but some of them decreased in the receptor-binding activity. By contrast, the cell-fusion activity was not affected. Reactivity of mutated HAs, having four or five oligosaccharides with human serum collected in 1976, was much lower than that of the wild-type HA. These observations raised the possibility that the addition of new oligosaccharides to the head of the HA of the H3N2 virus may have provided the virus with an ability to evade antibody pressures.

Single preoperative biliary drainage for malignant perihilar biliary stricture occasionally fails to control jaundice and cholangitis. Multiple biliary drainage is required in such cases, but their clinical background is unclear. We determined the clinical characteristics associated with the requirement for multiple biliary drainage. The consecutive 122 patients with malignant perihilar biliary stricture were enrolled in a single-center retrospective study. Preoperative biliary drainage was initially performed on the future remnant hepatic lobe. Additional drainage was performed if jaundice failed to improve or cholangitis developed in undrained hepatic lobes. Detailed clinical characteristics and the number of preoperative biliary drainage procedures required before operation were analyzed. Thirty-one patients (25.4 %) initially underwent multiple biliary drainage. However, 69 (56.7 %) required multiple biliary drainage by the time of the operation. In the univariate analysis, the initial serum bilirubin level, cholangitis, percutaneous portal vein embolization, history of inserted endoscopic biliary stenting, length of preoperative period, operative procedure, and Bismuth classification were significant factors. In the multivariate analysis using these factors, Bismuth classification was independently associated with the requirement for multiple biliary drainage. The number of patients who required multiple biliary drainage was higher in those with Bismuth-II (91.9 %), Bismuth-IIIa (65.7 %), and Bismuth-IV (92.9 %) than in those with Bismuth-I (22.2 %) and Bismuth-IIIb (18.2 %). Patients with Bismuth-II, Bismuth-IIIa, and Bismuth-IV are at higher risk for multiple biliary drainage. A strategy based on the Bismuth classification for performing preoperative biliary drainage is important for patients with malignant perihilar biliary stricture.

The antigenic structure of influenza A/H2N2 virus haemagglutinin (HA) was analysed using 19 monoclonal antibodies (MAbs) against the HA of A/Kayano/57. The antibodies were classified into three groups: group I had both haemagglutination inhibition and neutralization activities, group II had neutralization activity but no haemagglutination inhibition activity and group III had neither activity. Analysis of escape mutants selected by each of the group I and II antibodies identified six distinct antigenic sites: four (I-A to I-D) were recognized by group I MAbs and two (II-A and II-B) were recognized by group II MAbs. Sequence analysis of the HA genes of the escape mutants demonstrated that sites I-A, I-B and I-C form a contiguous antigenic area that contains the regions corresponding to antigenic sites A, B and D on the H3 molecule and that sites I-D and II-B are the equivalents of sites E and C, respectively, suggesting that the antigenic structure of the H2 molecule is largely similar to that of the H3 molecule. However, the H2 molecule differed from the H3 molecule in having a highly conserved antigenic site (II-A) in the stem domain. It was also found that most of the escape mutants selected by antibodies to sites I-A, I-B and I-C acquired a new glycosylation site at position 160, 187 or 131, respectively, which indicates that A/H2N2 viruses have the potential to gain at least one additional oligosaccharide on the tip of the HA, although this has never occurred during 11 years of its circulation in humans.

We reported previously that monoclonal antibody S16, which had been raised against the hemagglutinin-esterase (HE) glycoprotein of influenza C/Ann Arbor/1/50 (AA/50) virus, recognizes a linear epitope present on the HE molecules of all influenza C viruses examined except for viruses belonging to a lineage represented by Aichi/1/81 (AI/81). Comparison of the deduced amino acid sequence of HE between viruses on the AI/81-related lineage and those on the others suggests that the epitope recognized by S16 is located in a region containing amino acid residue 403 and that a change from Glu to Lys at this position causes the loss of reactivity with the antibody. To prove it, the wild type (WT) HEs of AA/50 and AI/81 as well as their mutants with an amino acid substitution at residue 403 were expressed in CV-1 cells from the recombinant simian virus 40 (SV40) and tested for reactivity with S16 by immunoprecipitation. The results showed that the AA/50 virus WT and AI/81 virus mutant HEs (both having Glu at residue 403) were reactive with S16 whereas the AI/81 virus WT and AA/50 virus mutant HEs (both having Lys at residue 403) were not. Furthermore, we examined the reactivity of S16 with two synthetic peptides (corresponding to residues 397–409) that possess Glu and Lys at position 403, respectively, by enzyme-linked immunosorbent assays. The results demonstrated that the former peptide but not the latter was reactive with S16. These observations support strongly the notion described above. During this study it was also found that S16 cross-reacts with large T antigen of SV40.

Four different antigenic sites (A-1, A-2, B-1, B-2) have been identified previously on the haemagglutinin-esterase (HE) glycoprotein of influenza C/Ann Arbor/1/50 virus with seven monoclonal antibodies (MAbs). In this study we produced 30 additional anti-HE MAbs, nine of which demonstrated at least one of the following activities: haemagglutination inhibition, receptor-destroying enzyme inhibition, haemolysis inhibition, and neutralization (group A). The remaining had none of these activities (group B). These antibodies, and those previously isolated, were used to construct a more complete antigenic map of the HE molecule. Operational and topological analyses showed that a minimum of nine non-overlapping or partially overlapping antigenic sites were present on the HE protein, five recognized by group A MAbs (A-1 to A-5) and four by group B (B-1 to B-4). Among these antigenic sites, site A-5 was unique in that MAbs to this site inhibited the receptor-destroying activity without influencing the receptor-binding activity, which supports the idea that the sites responsible for these two functions are separate. It was also found that several group B MAbs were cross-reactive with host cell antigens.

To clarify a longitudinal epidemiology, we isolated 280 hMPV strains from patients with acute respiratory infections in Yamagata, Japan, between 2004 and 2009. We observed that the high season for hMPV was from winter to spring (between January and May) and the low season was in the fall (around September and October). A further molecular analysis revealed that subgenogroup A2 (A2) strains were the most commonly isolated (151/280; 53.9%), followed by B2 (108/280; 38.6%) and B1 (19/280; 6.8%). Our results suggested that A2 and B2 have been endemically in circulation as the major types almost every year, whereas other subgenogroups have appeared less frequently.

Pre-mRNAs of the influenza A virus M and NS genes are poorly spliced in virus-infected cells. By contrast, in influenza C virus-infected cells, the predominant transcript from the M gene is spliced mRNA. The present study was performed to investigate the mechanism by which influenza C virus M gene-specific mRNA (M mRNA) is readily spliced. The ratio of M1 encoded by a spliced M mRNA to CM2 encoded by an unspliced M mRNA in influenza C virus-infected cells was about 10 times larger than that in M gene-transfected cells, suggesting that a viral protein(s) other than M gene translational products facilitates viral mRNA splicing. RNase protection assays showed that the splicing of M mRNA in infected cells was much higher than that in M gene-transfected cells. The unspliced and spliced mRNAs of the influenza C virus NS gene encode two nonstructural (NS) proteins, NS1(C/NS1) and NS2(C/NS2), respectively. The introduction of premature translational termination into the NS gene, which blocked the synthesis of the C/NS1 and C/NS2 proteins, drastically reduced the splicing of NS mRNA, raising the possibility that C/NS1 or C/NS2 enhances viral mRNA splicing. The splicing of influenza C virus M mRNA was increased by coexpression of C/NS1, whereas it was reduced by coexpression of the influenza A virus NS1 protein (A/NS1). The splicing of influenza A virus M mRNA was also increased by coexpression of C/NS1, though it was inhibited by that of A/NS1. These results suggest that influenza C virus NS1, but not A/NS1, can upregulate viral mRNA splicing.

We isolated and identified six subgenogroups (B2, B4, B5, C1, C2, and C4) of enterovirus 71 (EV71) between 1990 and 2007 in Yamagata, Japan. We measured neutralizing antibody (NT Ab) titers against those subgenogroup strains and the BrCr reference strain for antigenic analysis. Serological analysis of 83 residents in Yamagata in 2004 showed that differences in the NT Ab titer of each individual against the different subgenogroups were mostly within 4-fold. Furthermore, sera from guinea pigs, immunized with the B2 and C1 strains indicated cross-antigenicity among the seven different subgenogroups. In conclusion, our results showed that cross-antigenicity exists among EV71 strains from different subgenogroups circulating in the community through genomic evolution. Our results also suggest that eliciting neutralizing antibodies against one genotype is likely to confer cross-neutralization against other genotypes.

Background: Noroviruses (NV) are one of the leading causes of gastroenteritis in young children; however, the duration of NV shedding in young children is not well known. Methods: Fecal specimens were collected from children with acute gastroenteritis at a pediatric clinic during the period from November to December 2002 and tested for NV by reverse transcription– polymerase chain reaction. Results: Of 71 children infected with NV, 60 (84.5%) were less than 3 years old. Among children aged 2 years and those aged 2 to 5 years, the duration of illness was longer (7 days versus 3.5 days, P 0.0069), the maximum number of stools in a 24-hour period was greater (7 versus 3, P 0.0078) and a 20-point severity score was higher (11 versus 8, P 0.0031) in patients aged 2 years than in patients aged 2 to 5 years. Among the 23 children whose follow-up specimens were obtained, the median duration of NV shedding was 16 days (range, 5– 47 days). Virus shedding for more than 2 weeks after onset was observed in 75% (6 of 8), 71.4% (5 of 7) and 25% (2 of 8) of children aged 1 year, 1 year and 2 to 3 years, respectively. Three infants aged 6 months continued to excrete NV for an extremely long period (more than 42, 44 and 47 days from onset) after recovery. Conclusion: Long-term virus shedding after the disappearance of clinical symptoms was observed. Caution should be exercised when handling the excrement of infants and young children infected with NV.

The conformational maturation of the influenza C virus nucleoprotein (NP) synthesized in infected cells was investigated. Monoclonal antibodies (mAbs) that have previously been characterized [Sugawara, K., Nishimura, H., Hongo, S., Kitame, F., Nakamura, K., 1991. Antigenic characterization of the nucleoprotein and matrix protein of influenza C virus with monoclonal antibodies. J. Gen. Virol. 72, 103-109] enabled this molecular maturation to be detected. Both pulse-labeled and chased NPs could equally retain high reactivity with H31 mAb recognizing a linear epitope on the NP molecule. However, pulse-labeled NP showed three- to four-fold lower reactivity with H27 mAb recognizing a conformational epitope, compared to chased NP. Sedimentation analyses by sucrose gradient centrifugation revealed that the mature NP could readily participate in nucleocapsid formation while the immature NP was free. The immature NP was rapidly transported into the nucleus and its maturation seemed to occur after or during translocation into the nucleus. A single expression of NP cDNA in COS-1 cells demonstrated that the NP maturation was an intrinsic feature of the NP molecule without relation to other viral components.