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.

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.

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.

Cerebral CT angiography using a small volume of concentrated contrast material with a test injection method: optimal scan delay for quantitative and qualitative performance

OBJECTIVES

The objective of this study was to determine the optimal scan delay quantitatively and qualitatively in cerebral CT angiography (CTA) with a test injection method at the circle of Willis (cW).

METHODS

66 consecutive patients suspected of having unruptured intracranial aneurysms underwent CTA using 40 ml of 370 mg iodine ml(-1) contrast material (CM). After the time until CM arrival at the cW (T(cW)) was calculated, scan delay was divided into three groups according to T(cW) and scan duration (SD) between the second cervical vertebra and cW as follows: [(T(cW)+6)-SD] in 21 patients (Group A); [(T(cW)+8)-SD] in 23 patients (Group B); and [(T(cW)+10)-SD] in 22 patients (Group C). Arterial and venous attenuation in the intracranial vessels was measured. Mean attenuation values were compared quantitatively. The arterial enhancement and venous overlap at the cW and above the cW were qualitatively compared among the three groups.

RESULTS

Mean arterial attenuation in Groups B and C was significantly higher than that in Group A. Mean venous attenuation in Group C was significantly higher than those in Groups A and B. Arterial enhancement above the cW showed a significant difference between Groups A and C, and at the cW between Groups A and B, and Groups A and C. There was a significant difference in venous overlap among the three groups, except for that at the cW between Groups B and C.

CONCLUSIONS

Setting scan delay as [(T(cW)+8)-SD] s can produce the best performance both quantitatively and qualitatively.

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.

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.

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.

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.

An outbreak of psittacosis in a bird park in Japan

An outbreak of psittacosis related to a bird park occurred in Matsue City, Shimane Prefecture, Japan, during winter 2001. Seventeen cases of psittacosis (12 visitors, three staff, and two student interns) were confirmed. A cohort study was conducted among the park staff and students to determine the risk factors for the development of acute serologically confirmed psittacosis (SCP) infection. Being 'bird staff' had an increased risk of SCP infection (RR 3.96, 95% CI 1.48-10.58). Entering the staff building, where ill birds were maintained without proper isolation, was also associated with an increased risk of SCP infection (RR 3.61, 95% CI 1.03-12.6). Isolation of ill birds and quarantine measures were found to be insufficient. Dehumidifiers and a high-pressure water spray under a closed ventilation environment may have raised the concentration of Chlamydophila psittaci in the hothouses. Bird park staff and visitors should be educated about psittacosis.

Nonsteroidal anti-inflammatory drugs induce hypermotilinemia and disturbance of interdigestive migrating contractions in instrumented dogs

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce gastric ulcers due to inhibition of prostaglandin production. Prostaglandins have an influence on physiological gastrointestinal motility, but the relationships between NSAID-induced gastric ulcer, gastrointestinal motility and motilin are unknown. Fifteen dogs were allocated randomly to three groups in which either gelatin, meloxicam or indomethacin was administered. Fecal occult blood and gastrointestinal motility were monitored continuously for 6 days. In addition, analyses of the plasma motilin concentration, gastrointestinal endoscopy and gastric emptying, and detection of motilin cells were performed. Gastrointestinal motility was disturbed in the indomethacin group, presenting as disappearance of interdigestive migrating contractions (IMCs) 3 days before gastric ulcers were detected. Delayed gastric emptying and hypermotilinemia were observed significantly more often in the indomethacin group compared with the other groups. Motilin cell-crypt/villi ratio in the indomethacin group significantly decreased in the duodenum and jejunum, compared with the other groups. No significant changes in any tests were observed in the meloxicam group, when compared with the gelatin group. These findings suggest that the disturbance of IMCs caused by hypermotilinemia, with changes in motilin cell distribution, and delayed gastric emptying induced by indomethacin may contribute to the development of gastric ulcers.

Development of Reformative Surgery Method Using Partial Freezing for the Liver

To minimize surgical stresses including blood loss and operation time to the patients during hepatic resection, we studied the feasibility of a combination of a partial liver freezing technique and shape-memory alloy, which also enables a free-designed resection curve. In this surgical procedure, the region surrounding a tumor in the liver is frozen to excise and prevent hemorrhage. The liver was frozen by a Peltier module. The effects of cooling rate and freezing temperature on the excision force that arise between a scalpel and the liver are carried out experimentally as a basic research for partial freezing surgical procedures. A porcine liver was used as a liver sample. The physical properties were estimated by using the finite element method based on the heat transfer characteristics of the liver. Isolation of the liver was conducted using a scalpel attached to the end-effector of a 3 degrees of freedom robot. In the experiments, the minimum excision force was obtained at a temperature between 272K and 275K; therefore, it is preferable that the liver be excised within this temperature range. Lowering of the cooling rate decreases the excision force even if the temperature of the liver remains unchanged. The lower the temperature of the liver is, the larger the increment rate of excision force is with regard to the cooling rate.

Crystal structure of aquabis(4-aminobenzoato)cadmium dihydrate, Cd(H2O)(NH2C6H4COO)2 · 2H2O

C14H18CdN2O7, monoclinic, P121/c1 (no. 14), a = 14.86(2) Å, b = 6.15(1) Å, c = 17.76(2) Å, β = 104.23(4)°, V = 1572.4 Å3, Z = 4, Rgt(F) = 0.049, wRref(F2) = 0.121, T = 123 K.

Experimental surveillance using data on sales of over-the-counter medications--Japan, November 2003-April 2004

OBJECTIVES

This report describes a study to explore the possibility of using data on sales of over-the- counter (OTC) medications as part of a routine syndromic surveillance system aimed at early detection of infections of public health concern. A retrospective evaluation was conducted of sales of OTC medications used to treat the common cold. This report discusses the correlation of these data to influenza activity in Japan during the 2003-04 influenza season and evaluates the potential of using such data to predict influenza epidemics.

METHODS

Data from approximately 1,100 pharmacies throughout Japan collected during November 2003-April 2004 were analyzed. OTC sales data were compared with influenza incidence data (one weekly and two daily data sets) to determine correlations and predictability. Adjusted R-square was used as an index of goodness of-fit in the estimation. Data reflecting daily influenza activity were obtained from the National Surveillance of Daily Influenza Outpatients and the Mailing List-Based Influenza Epidemic Database. National sentinel surveillance data for influenza from approximately 5,000 sites nationwide also were analyzed.

RESULTS

Although a correlation was demonstrated between sales of OTC medications used to treat the common cold and concurrent influenza activity, analysis of sales data alone was not sufficient to determine influenza activity in advance even when sales promotion effects were excluded from the analysis.

CONCLUSION

Because visiting a health-care provider costs more than purchasing OTC medications, the hypothesis was formed that an ill person will purchase OTC medications first and visit a physician only if the condition does not resolve or worsens. The results of this study do not provide any clear evidence to support this hypothesis. For this reason, OTC sales do not appear to be a good candidate for a national real-time detection system for influenza epidemics in Japan.

Salmonella Enteritidis outbreak associated with a school-lunch dessert: cross-contamination and a long incubation period, Japan, 2001

A Salmonella Enteritidis (SE) outbreak in Japan was investigated with an observational study, analytical epidemiology and bacteriological examination (including phage typing). The outbreak occurred among 96 schoolchildren, and was caused by SE phage type 1. The outbreak source was dessert buns served at a school lunch (RR 42.55, 95 % CI 5.93-305.11, P < 0.001). The buns were probably cross-contaminated from eggs from a factory with a history of SE-contaminated products. The incubation period was longer than usual (3-16 days, median 8 days). A low contaminating dose may account for the long incubation period and low attack rate. Outbreak detection was hampered by the absence of routine Salmonella surveillance in Japan. The investigation was complicated by concurrent illnesses from other SE phage types. It was successful, in part, because adequate food samples were available for microbiological testing.

Vibrio vulnificus septicaemia in Japan: an estimated number of infections and physicians' knowledge of the syndrome

Questionnaire surveys were implemented to study the incidence and physicians' knowledge of Vibrio vulnificus infections in Japan. Registered emergency physicians were selected by stratified random sampling for a questionnaire survey. A total of 235 out of 386 physicians (61%) responded to the questionnaire and 12 V. vulnificus septicaemia cases were reported from 10 respondents. The annual estimated number of V. vulnificus septicaemia was calculated as 425 (95 % CI 238-752). The study also revealed that only 15.7 % (95 % CI 11.3-21.0) of responding physicians had a basic knowledge of V. vulnificus infection. Education for both physicians and people in the high-risk group for developing the infection (e.g. immunocompromised, chronic liver disease) will be necessary for the prevention, early diagnosis and appropriate treatment of the disease.

Heterogeneity of the fibre sequence in subgenus C adenoviruses

AIMS

To determine the nucleotide sequences of adenovirus (Ad) types 1 and 6 fibre genes; to clarify the molecular basis of the distinct haemagglutination properties of subgenus C Ads and their phylogenetic relations.

METHODS

Human Ad1 and Ad6 fibre genes were sequenced from genomic DNA by direct sequencing. Primer selection was based on alignment of the fibre gene of human Ad serotypes Ad2 and Ad5. Fibre based subgenus C specific polymerase chain reaction (PCR) was performed to check for deletions in field isolates of Ad6, as revealed by sequence analysis of the Ad6 prototype. A phylogenetic tree was constructed from the predicted amino acid (AA) sequences of the fibre gene of important Ads.

RESULTS

Ad1 and Ad6 comprise 1746 and 1584 nucleotides, encoding 582 and 528 AA, respectively. Ad6 showed deletions in motifs 15-17 (51 AA) of the shaft when compared with Ad1, Ad2, and Ad5. Subgenus C specific PCR with both prototype and field isolates also showed deletions in Ad6. In the shaft and knob, AA homology was 58.82-72.91% and 68.89-74.59%, respectively. The tail was 100% conserved. Phylogenetically, Ad1 and Ad6, including Ad2 and Ad5, formed a subgenus specific cluster, like other serotypes.

CONCLUSIONS

The fibre gene (including the knob region) of subgenus C Ads is heterogeneous, providing the molecular basis for lack of crossreactivity in the haemagglutination inhibition test. This heterogeneity could be helpful in fibre based genotyping of subgenus C field isolates. Phylogeny might be useful for subgenus specific identification of important field strains.

Gallbladder wall thickening associated with infectious mononucleosis

Acute infectious mononucleosis is a typical self-limited lymphoproliferative illness characterized by fever, tonsillar pharyngitis, and lymphadenopathy in adolescents and young adults. Thickening of the gallbladder wall is rarely observed. We report a case of infectious mononucleosis in which marked thickening of the gallbladder wall was detected by ultrasonography and computed tomography.

Serological and genetic characterisation of a unique strain of adenovirus involved in an outbreak of epidemic keratoconjunctivitis

AIMS

To characterise a novel strain of adenovirus (Ad) type Ad8 (genome type Ad8I) involved in an epidemic keratoconjunctivitis (EKC) outbreak in Hiroshima city using serological testing and sequence analysis of the fibre and hexon gene.

METHODS

A neutralisation test (NT) was performed in microtitre plates containing a confluent monolayer of A549 cells using 100 tissue culture infectious doses of virus and type specific antisera. The haemagglutination inhibition test was also carried out in microtitre plates with rat erythrocytes using four haemagglutination units of virus and twofold dilutions of serum. The fibre gene was sequenced by generating overlapping polymerase chain reaction products or by direct sequencing of genomic DNA. Primer selection was based on alignment of the fibre genes of human adenovirus serotypes Ad8, Ad19, Ad37, Ad9, and Ad15 available from Gene Bank.

RESULTS

The virus strain was specifically neutralised by anti-Ad8 antibodies, although there was a major crossreaction with anti-Ad9 antibodies. Haemagglutination was equally inhibited by anti-Ad8 and anti-Ad9 antibodies. The predicted amino acid sequences of the hypervariable regions (HVRs) of the Ad8I hexon gene showed higher homology with Ad9 (83.3%) than with Ad8 (62.0%). However, the Ad8I fibre knob was more homologous to Ad8 (94.4%) than to Ad9 (91.6%).

CONCLUSIONS

Ad8I is a unique strain of adenovirus because of its lower genomic homology with Ad8, major crossreactivity with Ad9 in NT, and mixed genetic organisation of HVRs of the hexon gene. These factors may have enabled the virus to circumvent acquired immunity, resulting in the outbreak.

Characterisation of hexon and fibre genes of a novel strain of adenovirus involved in epidemic keratoconjunctivitis

AIMS

To characterise a novel strain (M86) of adenovirus (Ad) involved in epidemic keratoconjunctivitis (EKC).

METHODS/RESULTS

The virus strain was neutralised by antisera to both Ad35 and Ad11. Restriction endonuclease analysis of genomic DNA showed 98% and 88% homology with Ad11 and Ad35, respectively. The deduced amino acid sequence of the hypervariable regions of (HVRs) of the hexon gene showed a higher homology with Ad35 (94.4%) than with Ad11 (83.7%). However, it was 100% homologous to Ad35 in HVRs 1, 2, 3, and 6 and to Ad11 in HVRs 4 and 6. In the fibre knob, the isolate was more homologous to Ad11 (99.4%) than to Ad35 (29.1%).

CONCLUSION

This novel strain of adenovirus showed similarities with both Ad11 and Ad35. The isolation of a novel strain like Ad35+11 is important because of its association with EKC.

Genetic characterisation of adenovirus type 8 isolated in Hiroshima city over a 15 year period

AIMS

To investigate the genetic differences among the strains of adenovirus type 8 (Ad8) circulating in Hiroshima city, Japan, and to study their circulation pattern.

METHODS

One hundred and twenty nine strains of adenovirus type 8 (Ad8) were isolated in Hiroshima City over a 15 year period (1983-97) from patients with keratoconjunctivitis, and analysed with six restriction enzymes-BamHI, HindIII, PstI, SacI, SalI, and SmaI-to investigate possible relations among the isolates and their genetic variability. Seven hypervariable regions of the hexon gene that carry the type specific epitope were also sequenced to investigate the variation among the genome types.

RESULTS

Restriction endonuclease analyses yielded three known genome types (Ad8A, 13 samples; Ad8B, seven samples; and Ad8E, 35 samples) and a novel genome type (Ad8I, 74 samples). Ad8A, Ad8B, and Ad8E were closely related, with 96% homology, whereas Ad8I had only 71% homology. Ad8A, Ad8B, and Ad8E shared 91.8% and 96.4% homology with regard to their amino acid and nucleotide sequences, respectively, with the isolate 1127 (accession no X74663). However, when compared with Ad8A, Ad8B, Ad8E, and isolate 1127, Ad8I shared only 62.7% and 69.9% homology with regard to amino acid and nucleotide sequences, respectively. Ad8A, Ad8B, and Ad8E had a unique 31 amino acid deletion in the hypervariable region 1 of the hexon gene, whereas Ad8I had a 33 residue deletion. The Ad8E strain that circulated from 1984 to 1995 was stable among the study population. Ad8I was isolated from an outbreak of epidemic keratoconjunctivitis in 1995 and was also isolated from sporadic cases until 1997.

CONCLUSIONS

These results confirmed that genetic variability occurs in Ad8 in the microenvironment and revealed the emergence of a new genome type (Ad8I).

Use of antiserum-coated latex particles for serotyping Streptococcus pneumoniae

The Quellung reaction provides a standard means for serotyping Streptococcus pneumoniae, but it requires microscopic examination with skillful technique. We have developed an improved agglutination method with anti-rabbit IgG-coated latex particles, which are sensitized with pooled antisera for serotyping/serogrouping S. pneumoniae. Our method is as specific and sensitive as the Quellung test, and much easier to perform.

Evaluation of a mass influenza vaccination campaign

Kawaura, a rural town in Kumamoto Prefecture, Japan, population approximately 6,800, started a mass influenza vaccination campaign in the 1999-2000 season for all residents > or = 3 years of age. The town provided free vaccinations to children < or = 13 years and the elderly > or = 65 years. Only 900 yen (US$8.80) was charged to the other residents for two vaccinations. In the 1999-2000 season, a total of 5,563 doses of vaccine were administered to 2,952 residents. Over 90% of the vaccinees received two doses. The program resulted in a vaccination rate of 43% of all residents. The vaccination rates for females and males were 40.7% and 36.8%, and for those of 3-14 years, 15-64 years, and > or = 65 years population were 75%, 31%, and 55%, respectively. The town spent a total of 5.78 million yen (US$56,700) for the campaign. The per-shot cost was estimated as 1,683 yen (US$16.50). From December 1999 through March 2000, a total of 233 town residents (15-101 years old, median 72) were admitted to the town hospital. Of the 233 inpatients, 22 (66-98 years old, median 78) developed respiratory illness, with 4 fatal outcomes. Of these 22 cases, 3 had been vaccinated twice, while 19 had not been vaccinated at all. The relative risk of vaccinees' hospitalization due to respiratory illness decreased to 0.13 compared with that of non-vaccinees (3/1,203 versus 19/1,003, vaccine efficacy = 0.87). Likewise, the relative risk of vaccinees death due to respiratory illness decreased to 0.28 compared with that of non-vaccinees (1/1,203 versus 3/1,003). The results of the Kawaura town's initiative should be helpful for better modeling of mass influenza vaccination campaigns.

[Field epidemiological investigation on an outbreak of Chlamydia pneumoniae infection--first recognized incidence in a nursing home for elderly in Japan]

Chlamydia pneumoniae (C. pneumoniae) is an emerging pathogen recognized in 1989. Although C. pneumoniae infection is known to give a great impact on public health in western countries, many aspects remain unclarified in Japan. During December 1999 and March 2000, respiratory symptoms among residents and employees in a nursing home for elderly implicated an outbreak of C. pneumoniae infection. Field epidemiological investigation confirmed that this is the first outbreak recognized in a nursing home setting in Japan, involving 31/59 (15 confirmed) residents and 9/41 (2 confirmed) employees. Fifteen residents developed severe C. pneumoniae infections including one fatal outcome with pneumonia. Epidemiological analysis did not identify risk factors which induce infection or severe illness by C. pneumoniae for the residents. However, for the employees, frequent contact with the residents was demonstrated as a significant risk factor for the infection. None of 13 employees who had no contact with the residents presented C. pneumoniae infection, while nine out of 28 employees who had frequent contact developed C. pneumoniae infections (RR infinite, P = 0.04). These results indicated that C. pneumoniae infection spread gradually by human-to-human droplet transmission without specific risk factors. This study raised current problems in diagnosing and treating the C. pneumoniae infection and the need to enhance the awareness of this disease.

Comparative analysis of host responses related to immunosuppression between measles patients and vaccine recipients with live attenuated measles vaccines

Measles virus infection induces a profound immunosuppression. We analyzed in a time-dependent manner peripheral bloods of one to two-year-old children immunized with live attenuated measles vaccines, compared with age-matched measles patients, for immunosuppression. In contrast to transient severe lymphopenia with measles patients, primarily due to extensive apoptosis of a broad spectrum of uninfected lymphocytes, neither apoptosis nor lymphopenia occurred with measles vaccine recipients. Increase in number and activation of NK cells, which might compensate for the lymphopenia in measles patients, were not found with the vaccinees. While cell surface expression of apoptosis-related molecules such as TNF-related apoptosis-inducing ligand (TRAIL), TRAIL-receptors, CD95(Fas) and Fas-ligand, and plasma interferon-gamma were increased for measles patients, they remained unchanged after vaccination. Plasma interleukin (IL)-18, which is responsible for inducing apoptosis in several infectious diseases, was increased predominantly with measles patients, whereas the increase remained marginal with the vaccinees. IL-10 was elevated transiently in both measles patients and vaccinees. Decrease in plasma IL-12, which is often correlated with T cell suppression, was not found for both cases. Serum IgM and IgG antibodies to measles virus were induced at lower titers in the vaccinees than measles patients. These results indicate that in contrast to wild-type measles virus, live measles vaccines hardly provoked host cytokine responses that lead to apoptotic cytolysis of uninfected lymphocytes, lymphopenia and immunosuppression, and thereby induced weaker immune responses to the virus.

The pathogenesis of Crohn's disease

Although much progress has been made in understanding the pathogenesis of Crohn's disease, the precise etiology of Crohn's disease still remains unknown. In our serial studies on Crohn's disease, we found a decrease in NK and ADCC activities as well as a decrease in the phagocytic activity by monocytes, whereas an increased superoxide production activity by monocytes was evident. On the other hand, the characterization of lymphocyte subsets has demonstrated no abnormalities. According to these findings, I would like to propose a new tentative hypothesis for the pathogenesis of Crohn's disease. It has been suggested that impaired killing system activities, such as phagocytic as well as NK and ADCC activities, are primarily responsible for the promotion and perpetuation of chronic inflammation and ulceration. When our attention is directed to the common target substances of these protective mechanisms, viral antigens appear as the most likely causative organism. Therefore, a lot of attention must be focused on viral infection as a causative factor. Furthermore, effects of psychological and physical stress on the disease onset or the recurrence of inflammatory bowel disease are also discussed.

Analysis of Japanese encephalitis epidemic in Western Nepal in 1997

We conducted an epidemiological study of a Japanese encephalitis (JE) outbreak in the southwestern part of Nepal in 1997. A high density of JE infections was found and it was estimated that 27.9% the total population were infected with JE virus in the study area. The fatality rate was 13.2% and there was no difference in the fatality rate between males and females over 5 years old. However, the case fatality rate was 2.1 times higher in females than in males (14.6% vs. 6.9%) among children under 5 years of age. Fifty-three blood samples were collected from suspected JE cases during the epidemic period in 1998. Findings for JE specific IgM revealed that clinical diagnoses of JE were serologically confirmed in an average 78% (70-93%) of patients in three collaborating hospitals. These studies demonstrated that JE was highly prevalent in the area and clinical diagnoses were reliable. Effective preventive measures should be taken against this vaccine-preventable disease.

Bis(mu-pyridine-2,6-carboxylato-O,N, O':O)bis[triaquamanganese(II)]-pyridine-2,6-dicarboxylic acid (1/2)

In the structure of the title compound, [Mn(2)(C(7)H(3)NO(4))(2)(H(2)O)(6)].2C(7)H(5)NO(4), a centrosymmetric dinuclear complex, hexaaaquabis(pyridine-2, 6-dicarboxylato)dimanganese(II) and free pyridine-2,6-dicarboxylic acid are present in a 1:2 ratio. In the complex, each Mn(2+) ion is coordinated by three O atoms and one N atom from the pyridine-2, 6-dicarboxylate ligands and by three water O atoms, resulting in a distorted pentagonal bipyramidal coordination. Within the centrosymmetric dinuclear complex, two Mn(2+) ions are bridged by two carboxylate O atoms. The crystal structure is stabilized by hydrogen bonds involving all the H atoms of the water ligands.

Ankycorbin: a novel actin cytoskeleton-associated protein

BACKGROUND

Actin cytoskeleton structures are essential for a wide variety of cell functions, including cell shape change, cell motility, cell adhesion, cell polarity and cytokinesis. Many actin filament (F-actin)-binding proteins have been isolated and implicated in the maintenance and reorganization of actin cytoskeleton structures.

RESULTS

We purified here a novel protein with a molecular mass of about 125 kDa (p125) from rat liver. We cloned its cDNA from a mouse kidney cDNA library and determined its nucleotide and deduced amino acid sequences. p125 was a protein of 979 amino acids with a calculated Mr of 108 847. p125 contained six ankyrin repeats in the N-terminal region and a domain predicted to form a coiled-coil structure in the C-terminal region. We named p125 ankycorbin (ankyrin repeat- and coiled-coil structure-containing protein). Northern blot analysis indicated that ankycorbin was ubiquitously expressed in all the tissues examined. Immunofluorescence and immunoelectron microscope analyses revealed that ankycorbin was associated with the cortical actin cytoskeleton structures in terminal web and cell-cell adhesion sites and stress fibres. However, ankycorbin did not directly bind to F-actin as estimated by the F-actin co-sedimentation assay.

CONCLUSIONS

These results indicate that ankycorbin is indirectly associated with the actin cytoskeleton structures, presumably through an unidentified factor and suggest that it is involved in their maintenance and/or reorganization.

catena-Poly[[diaqualithium(I)]-mu-[9H-purine-2,6(1H, 3H)-dionato-O2:N7]]

In the title compound, [Li(C(5)H(3)N(4)O(2))(H(2)O)(2)](n), the coordinate geometry about the Li(+) ion is distorted tetrahedral and the Li(+) ion is bonded to N and O atoms of adjacent ligand molecules forming an infinite polymeric chain with Li-O and Li-N bond lengths of 1.901 (5) and 2.043 (6) A, respectively. Tetrahedral coordination at the Li(+) ion is completed by two cis water molecules [Li-O 1.985 (6) and 1.946 (6) A]. The crystal structure is stabilized both by the polymeric structure and by a hydrogen-bond network involving N-H.O, O-H.O and O-H.N hydrogen bonds.

Association of Helicobacter pylori infection with atrophic gastritis and intestinal metaplasia

AIMS

To evaluate the effect of Helicobacter pylori infection and aging on atrophy and intestinal metaplasia of the gastric mucosa.

METHODS

One hundred and sixty-three patients were divided into three age groups and underwent an upper gastrointestinal endoscopy where no esophagitis, peptic ulcers, or malignancies were detected. Two biopsy specimens were obtained from the anterior and posterior walls of the antrum and of the fundus. These were used to evaluate the grade of gastritis, bacterial culture and histologic evidence of H. pylori infection.

RESULTS

Helicobacter pylori infection was found to be directly associated with an increased risk of gastritis grade (odds ratio (OR) = 90 (95% CI; 30-270)). An age of 60 years and older along with H. pylori infection was also strongly associated with an increased risk of atrophy (OR = 6.6, (95% CI; 2.9-15.2)); OR = 9.8, (95% CI; 2.7-35.4)), as was intestinal metaplasia of the gastric mucosa (OR = 5.5, (95% CI; 1.7-17.6)); OR = 7.9, (95% CI; 2.8-46.1)). The prevalence of atrophic gastritis increased with advancing age in H. pylori-infected patients, but no such phenomenon was observed in H. pylori-uninfected patients. The prevalence of intestinal metaplasia significantly increased with advancing age, irrespective of the presence of H. pylori infection. In addition, H. pylori uninfected female patients had a decreased risk of intestinal metaplasia.

CONCLUSIONS

These results suggest that atrophic gastritis is not a normal aging process, but instead is likely to be the result of H. pylori infection, while intestinal metaplasia is caused by both the aging process and H. pylori infection. A decreased risk of intestinal metaplasia found in uninfected female subjects may partly explain the lower prevalence of gastric cancer in females than in males.

Surveillance of viral gastroenteritis in Japan: pediatric cases and outbreak incidents

Surveillance results from pediatric cases and outbreaks of viral gastroenteritis in Japan are presented. In winter, both small round structured virus (SRSV, or Norwalk-like viruses) and rotavirus were detected from infants with gastroenteritis; however, in recent years, the prevailing time of SRSV infection has preceded that of rotavirus infection. Most nonbacterial gastroenteritis outbreaks were related to SRSV infection, and >60% of the outbreaks were caused by contaminated food. In small-sized outbreaks, raw oysters were the primary source of transmission. In large-sized outbreaks, school lunches and catered meals that were served at schools, banquet halls, and hospitals were most often implicated in the transmission of foodborne gastroenteritis.

Influenza surveillance system of Japan and acute encephalitis and encephalopathy in the influenza season

AIM

To understand the situation of influenza epidemics and neurologic complications during the influenza season in Japan.

METHODS

The influenza surveillance system in Japan was reviewed and the data on influenza/influenza-like illness and neurologic complications, such as acute encephalitis/encephalopathy, were evaluated.

RESULTS

From the data of the National Epidemiological Surveillance of Infectious Diseases (NESID), an increase in clinically diagnosed encephalitis/encephalopathy was clearly noted recently. Most cases reported were acute encephalitis/encephalitis. The number of cases of Reye's syndrome reported was stable and low in number, since the time of the recommendation of not using aspirin for pediatric febrile disease, particularly for influenza-like illness, in Japan. These acute encephalitis/encephalopathy cases were not correlated clearly with clinically diagnosed influenza patients before the 1997/98 influenza season from the surveillance data, although several case reports have shown a relationship.

CONCLUSIONS

It is clarified from the NESID that neurologic complications such as acute encephalitis/encephalopathy, apart from Reye's syndrome, have occurred associated with influenza virus infection, especially among young children. Further investigation should be necessary to find the pathogenesis of this serious complication of influenza virus infection and whether this is unique in Japan, due to unclarified factor/factors, or whether it has not been recognized in other countries.

[Current topics of acute encephalitis and encephalopathy: introductory remarks]

Encephalitis/encephalopathy is a neurological syndrome characterized by acute onset, symptoms of intracranial hypertension accompanying severe sequels or death. Encephalitis is caused by microbial infection of central nervous system, such as neurotrophic or conventional viruses. Infectious encephalopathy shows similar clinical symptoms to acute encephalitis, without any evidence of inflammation and microbial infection in brain tissues. The national epidemiological surveillance of the diseases is carried out to study the frequency and prognosis of patients with both diseases. The principal treatment is quite different in the both, in the former the eradication of microbial from the brain and in the latter the reduction of pressure of brain edema. Furthermore, the improvement of the brain with severe destruction requires such new step to reduce the activities of enzymes or cytokines to destroy brain tissues, as a mild hypothermia to lower body and brain temperature to 33-34 degrees C.

[Epidemiology--surveillance information]

Recent data of the National Epidemiological Surveillance of Infectious Diseases (NESID) showed that neurological complications associated with influenza virus infection, such as acute encephalitis/encephalopathy (excluding Reye's syndrome) have increased in number especially among young children. Further investigation is necessary to find the pathogenesis of these serious complications and clarify whether this phenomenon is due to unclarified factor(s) unique in Japan or it has reminded unrecognized in other countries.