Web survey-based selection of controls for epidemiological analyses of a multi-prefectural outbreak of enterohaemorrhagic Escherichia coli O157 in Japan associated with consumption of self-grilled beef hanging tender.

An outbreak of enterohaemorrhagic Escherichia coli O157 occurred in multiple prefectures of Japan in November 2009. We conducted two case-control studies with trace-back and trace-forward investigations to determine the source. The case definition was met by 21 individuals; 14 (66.7%) were hospitalised, but no haemolytic uraemic syndrome, acute encephalopathy or deaths occurred. Median age was 23 (range 12-48) years and 14 cases were male (66.7%). No significant associations with food were found in a case-control study by local public health centres, but our matched case-control study using Internet surveys found that beef hanging tender (or hanger steak), derived from the diaphragm of the cattle, was significantly associated with illness (odds ratio = 15.77; 95% confidence interval, 2.00-124.11). Pulsed-field gel electrophoresis analysis of isolates from patients and the suspected food showed five different patterns: two in faecal and food samples, and another three in patient faecal samples only, although there were epidemiological links to the meat consumed at the restaurants. Trace-back investigation implicated a common food processing company from outside Japan. Examination of the logistics of the meat processing company suggested that contamination did not occur in Japan. We concluded that the source of the outbreak was imported hanging tender. This investigation revealed that Internet surveys could be useful for outbreak investigations.

Risk of haemolytic uraemic syndrome caused by shiga-toxin-producing Escherichia coli infection in adult women in Japan.

Shiga-toxin-producing Escherichia coli (STEC) infections usually cause haemolytic uraemic syndrome (HUS) equally in male and female children. This study investigated the localization of globotriaosylceramide (Gb3) in human brain and kidney tissues removed from forensic autopsy cases in Japan. A fatal case was used as a positive control in an outbreak of diarrhoeal disease caused by STEC O157:H7 in a kindergarten in Urawa in 1990. Positive immunodetection of Gb3 was significantly more frequent in female than in male distal and collecting renal tubules. To correlate this finding with a clinical outcome, a retrospective analysis of the predictors of renal failure in the 162 patients of two outbreaks in Japan was performed: one in Tochigi in 2002 and the other in Kagawa Prefecture in 2005. This study concludes renal failure, including HUS, was significantly associated with female sex, and the odds ratio was 4·06 compared to male patients in the two outbreaks. From 2006 to 2009 in Japan, the risk factor of HUS associated with STEC infection was analysed. The number of males and females and the proportion of females who developed HUS were calculated by age and year from 2006 to 2009. In 2006, 2007 and 2009 in adults aged >20 years, adult women were significantly more at risk of developing HUS in Japan.

Increased prevalence of group A streptococcus isolates in streptococcal toxic shock syndrome cases in Japan from 2010 to 2012.

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and high mortality. In Japan, appropriate notification measures based on the Infectious Disease Control law are mandatory for cases of STSS caused by ß-haemolytic streptococcus. STSS is mainly caused by group A streptococcus (GAS). Although an average of 60-70 cases of GAS-induced STSS are reported annually, 143 cases were recorded in 2011. To determine the reason behind this marked increase, we characterized the emm genotype of 249 GAS isolates from STSS patients in Japan from 2010 to 2012 and performed antimicrobial susceptibility testing. The predominant genotype was found to be emm1, followed by emm89, emm12, emm28, emm3, and emm90. These six genotypes constituted more than 90% of the STSS isolates. The number of emm1, emm89, emm12, and emm28 isolates increased concomitantly with the increase in the total number of STSS cases. In particular, the number of mefA-positive emm1 isolates has escalated since 2011. Thus, the increase in the incidence of STSS can be attributed to an increase in the number of cases associated with specific genotypes.

Epidemiological analysis of a large enterohaemorrhagic Escherichia coli O111 outbreak in Japan associated with haemolytic uraemic syndrome and acute encephalopathy.

A large outbreak of enterohaemorrhagic Escherichia coli (EHEC) O111 and O157 occurred in Japan in April 2011. We conducted an unmatched case-control study and trace-back investigation to determine the source of EHEC O111 infection and risk factors for severe complications. Pulsed-field gel electrophoresis was performed to help define cases. A total of 86 individuals met the case definition. Of these, 40% experienced haemolytic uraemic syndrome (HUS), 24% acute encephalopathy, and 6% died. Illness was significantly associated with eating the raw beef dish yukhoe (odds ratio 19·64, 95% confidence interval 7·03-54·83), the likely food vehicle. EHEC O111 and its closely related stx-negative variants were found in the beef. HUS occurred most frequently in individuals aged 5-9 years, and this age group was significantly associated with acute encephalopathy. The prevalence of HUS and acute encephalopathy was higher than in previous non-O157-related outbreaks, indicating a high risk of severe complications.

Aberrant forms of Yersinia pseudotuberculosis as spheroplasts and filaments in yersiniosis in squirrel monkeys.

This report describes atypical cases of yersiniosis in squirrel monkeys in which aberrant forms of Yersinia pseudotuberculosis were seen. There were 2 outbreaks due to yersiniosis in squirrel monkeys in Japan. The monkeys had systemic necrotizing and hemorrhagic lesions with Gram-negative rod-shaped bacilli and microthromboembolism in the kidneys. Some lesions contained filaments, globular bodies, and other pleomorphic forms of bacteria. All forms were usually seen in the same lesions, and those with pleomorphic morphology appeared to be an intermediate form between the rod-shaped bacteria and the filaments or globular bodies. In addition, they had strong immunolabeling for Y. pseudotuberculosis, as did the rod-shaped bacteria. Therefore, the globular bodies, filaments, and others are strongly suspected to be shape-changed bacilli of Y. pseudotuberculosis. These morphologically altered bacteria could cause errors in diagnosis since they resemble fungi or protozoa, and special staining techniques, including immunohistochemistry, can be helpful in establishing the correct diagnosis.

Genetic analyses of GII.17 norovirus strains in diarrheal disease outbreaks from December 2014 to March 2015 in Japan reveal a novel polymerase sequence and amino acid substitutions in the capsid region.

A novel GII.P17-GII.17 variant norovirus emerged as a major cause of norovirus outbreaks from December 2014 to March 2015 in Japan. Named Hu/GII/JP/2014/GII.P17-GII.17, this variant has a newly identified GII.P17 type RNA-dependent RNA polymerase, while the capsid sequence displays amino acid substitutions around histo-blood group antigen (HBGA) binding sites. Several variants caused by mutations in the capsid region have previously been observed in the GII.4 genotype. Monitoring the GII.17 variant's geographical spread and evolution is important.

A Shiga toxin-producing Escherichia coli O157 outbreak associated with consumption of rice cakes in 2011 in Japan.

In May 2011, an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157 was reported from Yamagata Prefecture, Japan. Investigations, including a case-control study, revealed that the outbreak was linked to two varieties of rice cakes produced by a local manufacturer between 2 and 7 May. Active and passive surveillance identified 136 suspected cases, 142 confirmed cases, 26 asymptomatic cases, and 25 secondary cases. While no environmental samples taken from the manufacturing premises tested positive for STEC, other than a stool sample taken from one employee, on-site and epidemiological investigations indicated that STEC was introduced during the manufacturing process of rice cakes rather than through contamination of raw materials. This was the first reported outbreak of STEC associated with cakes and confectionery in Japan, which indicates that contamination and outbreaks of STEC can occur in any food unless proper precautions are taken.

A norovirus outbreak associated with environmental contamination at a hotel.

SUMMARYIn December 2006, an outbreak of gastroenteritis occurred involving 372 guests and 72 employees at a hotel after a guest vomited in corridors on the third (F3) and 25th (F25) floors. Norovirus with identical genotype was confirmed by real-time reverse transcription-polymerase chain reaction in faecal samples from guest cases and employees. Spread of the outbreak on F25 was compared with that on F3. The attack rate in the guests who visited F25 alone (15·0%, 106/708 guests) was significantly higher than in those who visited F3 alone (3·5%, 163/4710 guests) (relative risk 4·3, 95% confidence interval 3·4-5·5, P < 0·001). The outbreak on F3 ended within 2 days, while that on F25 extended over 7 days. The environmental ratios of F3 to F25 were 7·4 for volume, 6·9 for floor area and 7·6 for ventilation rate. This outbreak suggests that environmental differences can affect the propagation and persistence of a norovirus outbreak following environmental contamination.

Construction of syndromic surveillance using a web-based daily questionnaire for health and its application at the G8 Hokkaido Toyako Summit meeting.

We constructed a syndromic surveillance system to collect directly information on daily health conditions directly from local residents via the internet [web-based daily questionnaire for health surveillance system (WDQH SS)]. This paper considers the feasibility of the WDQH SS and its ability to detect epidemics. A verification study revealed that our system was an effective surveillance system. We then applied an improved WDQH SS as a measure against public health concerns at the G8 Hokkaido Toyako Summit meeting in 2008. While in operation at the Summit, our system reported a fever alert that was consistent with a herpangina epidemic. The highly mobile WDQH SS described in this study has three main advantages: the earlier detection of epidemics, compared to other surveillance systems; the ability to collect data even on weekends and holidays; and a rapid system set-up that can be completed within 3 days.

Clinical features of cases of influenza A (H1N1)v in Osaka prefecture, Japan, May 2009.

This report describes the clinical characteristics of influenza A(H1N1)v virus infection in Osaka. By the end of May, 171 cases had been reported in Osaka. Most patients were from one school. No patient had a serious underlying medical condition.Clinical symptoms were mild and resembled those of seasonal influenza. The sensitivity of the rapid antigen test was 77%. Antivirals were given to the majority of the cases. Early antiviral treatment may have shortened the duration of fever.

Assessment of secondary attack rate and effectiveness of antiviral prophylaxis among household contacts in an influenza A(H1N1)v outbreak in Kobe, Japan, May-June 2009.

This report describes the assessment of the secondary attack rate (SAR) and the effectiveness of post-exposure antiviral prophylaxis among household contacts in the first domestic outbreak of a novel influenza A(H1N1)v between mid-May and early June 2009 in Kobe city, Japan. Of the 293 subjects, 14 (4.8%) household contacts met the case definition and most secondary cases were probably infected around the time of symptom onset date of the respective index case. The SAR among household contacts who did not receive prophylaxis was 7.6%, similar to the rate of seasonal influenza, and the attack rate in siblings was significantly higher than that in parents. We conclude that it is important to establish routine infection control measures for households in order to prevent the spread of the virus among household contacts and, possibly, to the community. We could not conclude whether antiviral prophylaxis was effective or not. However, among close contacts with underlying disease who received prophylaxis, nobody developed a severe form of the disease.

Epidemiology of influenza A(H1N1)v virus infection in Japan, May-June 2009.

Between 9 May and 4 June 2009, a total of 401 laboratory-confirmed cases of influenza A(H1N1)v virus were reported in Japan, from 16 of the 47 Japanese prefectures. The two areas most affected were Osaka prefecture and Kobe city where outbreaks in high schools occurred leading to school closures. To date all cases have had symptoms consistent with seasonal influenza and no severe or fatal cases have been reported.

Radial glia marker expression following experimental intracerebral hemorrhage.

In this study, we examine 3CB2 expression, a marker of radial glia, after intracerebral hemorrhage (ICH). Adult male Sprague-Dawley rats received an intracaudate injection of 100 microL autologous whole blood. Animals were sacrificed, and 3CB2 expression was quantified on Western blot. Single and double labeled immunohistochemistry was used to identify which cells express 3CB2. Neurobehavioral examinations (forelimb placing test) were perfomed as an evaluation of function. By Western blot, 3CB2 was strongly expressed at day 3 and expression persisted for at least 1 month. By immunohistochemistry, 3CB2 immunoreactivity was present in large numbers of astrocytes surrounding the hematoma at day 3 after ICH. At 1 month later, 3CB2 immunoreactivity was co-localized with a neuronal marker (TUC-4). Neurobehavioral function in the 1 month after ICH group was significantly improved compared with that of 3 days after ICH. The ICH-induced 3CB2 expression in astrocytes may reflect an early response of these cells to injury, while the delayed expression in neurons might be a part of the adaptative response to injury, perhaps leading to recovery of neurobehavioral function.

Binding characteristics of a major thyroid hormone metabolite, 3,3',5'-triiodo-L-thyronine, to bovine serum albumin as measured by fluorescence.

The interaction between a major thyroid hormone metabolite, 3,3',5'-triiodo-L-thyronine and bovine serum albumin was investigated by fluorescence measurements. The apparent binding constants were obtained at various pHs assuming the equivalence and independence of the interaction sites on the protein from the fluorescence titration curves. The maximum binding was attained at pH 8.0, and the apparent binding constant was (5.28 +/- 0.13).10(5) M-1 with one binding site per albumin molecule. Thermodynamic parameters were also determined from the van't Hoff plot of the apparent binding constants at pH 7.5. The free energy change, enthalpy change and entropy change were -7.70 +/- 0.09 kcal.mol-1, -4.59 kcal.mol-1 and 10.2 e.u., respectively.

The crystal structure of a major metabolite of thyroid hormone: 3,3',5'-triiodo-L-thyronine.

Two independent conformations of the thyroinactive thyroid hormone metabolite, 3,3',5'-triiodo-L-thyronine (rT3) were determined by X-ray diffraction methods. The conformations show significant difference in the lettering geometry when compared with those of the thyroactive thyroxine (T4) and 3,5,3'-triiodo-L-thyronine (T3). The diphenyl ether conformation of the two conformers of rT3 is an anti-skewed one, in which the torsion angles, phi (C5-C4-O4-Cl') are 8 degrees and -6 degrees, and phi' (C4-O4-Cl'-O6') are 86 degrees and 87 degrees. This conformation is in contrast to a twist-skewed one of T4 and T3. The difference in the binding abilities between T4, T3 and rT3 to thyroxine binding carrier proteins in serum or to a nuclear receptor protein may be explained by the characteristic solid-state conformations of these metabolites.

The effect of guanidine hydrochloride on the conformation of bovine pancreatic DNAase I as measured with circular dichroism.

The denaturation of bovine pancreatic DNAase I (EC 3.1.21.1) by guanidine hydrochloride (GdnHCl) has been investigated with circular dichroism in the presence and absence of 1 mM Ca2+ at the wavelength region of 210-240 nm at 12.25 and 36 degree C. The change of the molar ellipticity at 220 nm by GdnHCl titration showed cooperative transition at each temperature and the midpoints of the titrations occurred near 2 M GdnHCl. At each temperature, the denaturation of DNAase I in the presence of 1 mM Ca2+ occurred a little slowly as compared with that in the absence of Ca2+. This suggests that 1 mM Ca2+ can to some extent stabilize the secondary structure of DNAase I against GdnHCl denaturation. The apparent free energy for the denaturation of DNAase I obtained by GdnHCl titration was calculated as 9.3 +/- 0.3 kcal/mol and 8.9 +/- 0.2 kcal/mol at 25 degree C in the presence and absence of 1 mM Ca2+, respectively. The possible regions for the alpha -helix and beta -structure of DNAase I were predicted from the amino acid sequence by probability calculation of Chou, P.Y. and Fasman, G.D., Adv. Enzymol. 47, 45-148. The characteristic feature is that the NH2-terminal half of DNAase I is rich in beta -structure and the COOH-terminal half contains mainly alpha -helix.

A new quadruple therapy for Helicobacter pylori: influence of resistant strains on treatment outcome.

BACKGROUND: There have been no reports concerning the efficacy and safety of a 1-week quadruple therapy regimen of omeprazole, amoxycillin, roxithromycin and metronidazole for Helicobacter pylori infections and the impact of primary resistance on the eradication rate. METHODS: One hundred and sixty-nine consecutive patients with peptic ulcer disease as well as gastritis with biopsy-proven H. pylori infection were entered into an open study of omeprazole 20 mg o.m., amoxycillin 500 mg t.d.s., roxithromycin 150 mg b.d., and metronidazole 250 mg t.d.s. Helicobacter pylori status was determined by urease test, histology and culture. Susceptibility to amoxycillin, metronidazole and roxithromycin was determined by the E-test. RESULTS: H. pylori was eradicated in 155 out of 169 (92%; 95% CI 88-96%) by intention-to-treat analysis, and in 155 out of 163 (95%; 95% CI 92-98%) by per protocol analysis. The prevalence of primary resistance against amoxycillin, roxithromycin and metronidazole was 2 out of 166 (1%), 16 out of 166 (10%) and 27 out of 166 (16%), respectively. H. pylori was eradicated in 25 out of 27 (93%) patients with metronidazole-resistant strains compared with 130 out of 136 (96%) in patients with metronidazole-sensitive strains of H. pylori. It was eradicated in 15 out of 16 (94%) patients with roxithromycin-resistant strains while in 140 out of 147 (95%) patients with roxithromycin-sensitive strains of H. pylori, and in two out of two (100%) patients with amoxycillin-resistant stains compared with 153 out of 161 (95%) in patients with amoxycillin-sensitive strains. H. pylori was eradicated in three out of four (75%) patients with double resistance against metronidazole and roxithromycin compared with 152 out of 159 (96%) patients with sensitive strains to metronidazole and or roxithromycin. None of these differences were statistically significant. Severe side-effects were found in only one out of 169 patients-anaphylaxis due to penicillin. CONCLUSIONS: The 1-week quadruple therapy with omeprazole, amoxycillin, metronidazole and roxithromycin was found to eradicate H. pylori in over 90% of all patients. This regimen was also found to be beneficial for patients with pre-treatment resistant strains to metronidazole, roxithromycin or amoxycillin, and was observed to be safe and well-tolerated.

Regulation of nerve growth factor and nerve growth factor receptor production by NMDA in C6 glioma cells.

The synthesis of nerve growth factor (NGF) and nerve growth factor receptor (NGFR) were studied in a C6 glioma cell line by Northern blot hybridization. In response to a glutamate agonist N-methyl-D-aspartic acid (NMDA), NGF mRNA increased by up to 2-fold after 4-12 h of culture. The non-NMDA receptor agonists, quisqualate and kainate, did not induce any increase of NGF mRNA, and kainate actually produced a decrease. The increase in NGF mRNA in response to NMDA was dose-dependent at 1, 5 and 10 microM. NGF receptor (NGFR) mRNA showed changes in expression which were similar to those for NGF mRNA, but were less marked. The specific glutamate antagonist 2-aminophosphonovaleric acid (APV) blocked the increase of NGF mRNA produced by NMDA. In the absence of Ca2+, an increase of NGF mRNA was still observed but in the presence of 1 mM ethylglycol-bis-(beta-aminoethyl ether) N,N'-tetraacetic acid (EGTA), NGF mRNA production abolished. The mechanism producing an increase in NGF mRNA by NMDA may be mediated by cyclic AMP since intracellular cyclic AMP and NGF mRNA levels both increased following treatment with NMDA or dibutyryl cyclic AMP.

Physicochemical properties of 57 kDa thyroid hormone binding protein from rat liver nuclei.

The nuclear thyroid hormone binding protein (NTHB) with the molecular weight of 57 kDa was obtained from rat liver nuclear extracts by using HPLC and DEAE-Sephadex A-25 ion exchange chromatography methods. Fluorescein isothiocyanate-labeled 3,5,3'-triiodo-L-thyronine (F-T3) was used as a fluorescent probe to identify the hormone binding protein. Purified NTHB has a single binding site for T3 with the apparent binding constant of (3.3 +/- 0.7) X 10(8) M-1. NTHB is an acidic protein with a pI of 5.0. The secondary structure of NTHB is characterized by about 42% helical and 18% beta-structure from CD measurements.

Minor conformational changes of yeast tRNAPhe anticodon loop occur upon aminoacylation as indicated by Y base fluorescence.

The Y base fluorescence of highly purified yeast tRNAPhe was measured in order to detect possible conformational changes of the anticodon loop, which were induced as a consequence of aminoacylation. A small enhancement of Y base fluorescence intensity in the order of 5% was observed in situ during aminoacylation. The rotational mobility of the Y base of Phe-tRNAPhe and tRNAPhe was determined by measuring the fluorescence polarization at various temperatures between 5 degrees C and 35 degrees C. Differences in the fluorescence polarization of the Y base between these tRNAs were however not observed. These results confirm that minor changes in the microenvironment of the Y base occur upon aminoacylation, whereas significant conformational changes of the anticodon loop can be excluded.