Time course characteristics of human herpesvirus 6 specific cellular immune response and natural killer cell activity in patients with exanthema subitum.

The time-course of cell-mediated immunity in exanthema subitum is not well documented. The lymphoproliferative response to purified human herpesvirus 6 (HHV-6) antigen and to phytohemagglutinin was measured and natural killer (NK) cell activities determined in three consecutive specimens obtained biweekly from 18 young children and infants with exanthema subitum. Virus isolation and PCR detection of virus DNA and determination of neutralization antibody to HHV-6 and -7 were also carried out. The magnitude of the HHV-6 specific lymphoproliferative response varied; however, in most cases the time course kinetics revealed a low response in the acute phase with a subsequent gradual increase. In contrast, NK cell activities were high in the acute phase and declined gradually during convalescence. The lymphoproliferative response to phytohemagglutinin did not show a consistent trend in kinetics of time; however, dynamic changes in activity were observed in patients during the acute and convalescent periods. The results suggest that NK cells play a major role in resolving acute phase infection while specific lymphocyte activity develops later. The cause of the delayed development of HHV-6 specific lymphoproliferative response is unknown. The lymphoproliferative response to phytohemagglutinin ratios implied that HHV-6 infection has some impact on host T-cell immunity during the course of exanthema subitum.

Outbreak of larval Echinococcus multilocularis infection in Japanese monkey (Macaca fuscata) in a zoo, Hokkaido: western blotting patterns in the infected monkeys.

A high prevalence of larval Echinococcus multilocularis (Em) infection was found in zoo primates in Hokkaido, Japan. In October 1997, a Japanese monkey (Macaca fuscata) died and histopathologically diagnosed as alveolar hydatidosis. Serum samples were collected from the remaining Japanese monkeys and examined for antibodies against Em by enzyme-linked immunosorbent assay and western blotting. Serological tests showed 12 more animals of the remaining 57 monkeys were possibly infected. Ultrasonography revealed that nine of these 12 animals had a cystic lesion in the liver. The band patterns of western blotting in the monkeys were very similar to those in human.

Localization and function in endoplasmic reticulum stress tolerance of ERdj3, a new member of Hsp40 family protein.

Heat shock protein 40 (Hsp40) family proteins are known to bind to Hsp70 through their J-domain and regulate the function of Hsp70 by stimulating its adenosine triphosphatase activity. In the endoplasmic reticulum (ER), there are 5 Hsp40 family proteins known so far, 3 of which were recently identified. In this report, one of the novel Hsp40 cochaperones, ERdj3, was characterized in terms of its subcellular localization, stress response, and stress tolerance of cells. By using ERdj3-specific polyclonal antibody, endogenous ERdj3 protein was shown to reside in the ER as gene transfer-mediated exogenous ERdj3. Analysis of the expression level of endogenous ERdj3 protein revealed its moderate induction in response to various ER stressors, indicating its possible action as a stress protein in the ER. Subsequently, we analyzed whether this molecule was involved in ER stress tolerance of cells, as was the case with the ER-resident Hsp70 family protein BiP. Although overexpression of ERdj3 by gene transfection could not strengthen ER stress tolerance of neuroblastoma cells, reduction of ERdj3 expression by small interfering ribonucleic acid decreased the tolerance of cells, indicating that ERdj3 might have just a marginal role in the ER stress resistance of neuroblastoma cells. In contrast, overexpression of ERdj3 notably suppressed vero toxin-induced cell death. These data suggest that ERdj3 might have diverse roles in the ER, including that of the molecular cochaperone of BiP and an as yet unknown protective action against vero toxin.

Phenotypic and genotypic characterization of beta-D-glucuronidase-positive Shiga toxin-producing Escherichia coli O157:H7 isolates from deer.

Beta-glucuronidase-positive (GUD+) Shiga toxin-producing Escherichia coli (STEC) O157:H7 was isolated from both an asymptomatic woman and uncooked deer meat in her possession in Hokkaido, Japan. The phenotypic and genotypic characteristics of the two isolates were identical or closely related, indicating probable transmission of the deer isolate to the woman. Moreover, several other GUD+ STEC O157:H7 strains investigated belonged to the distinct atypical GUD+ STEC O157:H7 group that has been identified previously. This is the first report that deer can be a reservoir of GUD+ STEC O157:H7 in Japan.

Poor immune responses to influenza vaccination in infants.

Twenty-two and 37 infants and young children received two doses of influenza HA vaccine before the 2001-2002 influenza season and before the 2002-2003 season, respectively. Two or three serial specimens were obtained, before and 1 month after the first vaccination as well as 1 month after the second vaccination. Infants showed a significantly poor HI antibody rise and lymphocyte response compared with young children aged > or =12 months. Time kinetics of the lymphoproliferative responses to influenza antigen among young children varied whereas their activities in infants were typically negative before immunization and increased after vaccination. Infants responded poorly to HA influenza vaccine compared with young children.

Depression in Japanese community-dwelling elderly--prevalence and association with ADL and QOL.

This cross-sectional study examined the prevalence of screening-based depression and compared the scores of activities of daily living (ADL) and quality of life (QOL) between community-dwelling elderly subjects with and without depression in Japan. Elderly subjects aged 65 or older living in four rural towns participated in 2000 or 2001 (n = 5363, female 58.3%, mean (S.D.) age 74.6 (7.0) years). Depressive symptoms were assessed using a 15-item Geriatric Depression Scale (GDS-15) and ADL, higher functions, and medical and social histories were assessed by self-report questionnaires. For assessing subjective QOL, a 100 mm visual analogue scale was used. One thousand seven hundred ninety-eight participants (33.5%, range, 32.3-34.6%) had suggestive depression using cutoff 5/6 of GDS-15. Subjects with depression revealed significantly lower scores for ADL and QOL than those without depression. Prevalence of screening-based depression was similar in the four different rural Japanese towns. However, the reported prevalence of depression varies enormously in different country. Primary physicians and caregivers should pay more attention to depression in the community-dwelling elderly population, especially below the threshold of major depression as minor depression or dysthymia.

Circadian heart rate and blood pressure variability considered for research and patient care.

OBJECTIVES: To review mechanisms of circadian variations in heart rate variability (HRV) and blood pressure variability (BPV) and mortality and morbidity due to cardiovascular diseases (CVD). METHODS: Results from 7-day/24-h HRV and BPV are interpreted by gender and age-specified reference values in the context of a Medline search. RESULTS: Abnormal HRV and BPV measured around the clock for 7 days provides information on the risk of subsequent morbid events in subjects without obvious heart disease and without abnormality outside the conventional (in the sense of chronobiologically unquantified) physiological range. Meditation, beta-blockers, ACE inhibitors, n-3 fatty acids and estrogens may have a beneficial influence on HRV, but there is no definitive outcome-validated therapy. Low HRV has been associated with a risk of arrhythmias and arrhythmic death, unstable angina, myocardial infarction, progression of heart failure and atherosclerosis. BPV may be characterized by treatable circadian-hyper-amplitude-tension (CHAT), which can be transient '24-h CHAT' or '7-day-CHAT', MESOR-hypertension and/or an unusually-timed (odd) circadian acrophase (ecphasia), all associated with an increased risk of stroke, stroke death, myocardial infarction, and kidney disease. CONCLUSIONS: Precise insight into the patho-physiology in time of HRV and BPV is needed with development of a consensus on best measures of HRV for clinical purposes and to determine when a 7-day record interpreted chronobiologically suffices and when it does not, for detection within as well as outside the conventional normal range, for diagnostic clinical practice and to direct therapy of risk greater than that associated with hypertension, smoking or any other risk factor.

[Heart rate variability analysis and neurobehavioral function in community-dwelling older people aged 75 or older].

BACKGROUND: Although heart rate variability (HRV) has been found to be associated with increased mortality in the elderly, the association of HRV and cognitive function and activity of daily living (ADL) capacity in the very elderly are not clear. METHODS: A sample of very elderly people (N = 138), aged 75 years and older, living in Urausu, Hokkaido, participated in this study. Participants were classified into three groups: normal, borderline, and dementia. Time and frequency domain measures of HRV were compared with behavioral and cognitive functions. RESULTS: HRV components, except for the LF/HF ratio, did not correlate with age in the very elderly. The LF component showed a statistically significant correlation with all the variables of behavioral functions. Most HRV components showed statistically significant and positive correlations with the flexibility of the back. The LF and LF/HF ratio were significantly lower in the dementia group than in the normal group. CONCLUSION: Although the meaning of the LF component is still controversial, we foundadefinite relationship between the LF component and behavioral functions. A positive relationship between most HRV components and the flexibility of the back may suggest that reduced flexibility leads to deteriorated cardiopulmonary function and reduced HRV. A further prospective study is needed to examine whether HRV and neurobehavioral functions are independent predictors of morbidity and mortality in very elderly people.

Clonal structure of Shiga toxin (Stx)-producing and beta-D-glucuronidase-positive Escherichia coli O157:H7 strains isolated from outbreaks and sporadic cases in Hokkaido, Japan.

A total of 22 clonal phenotypic variants of Shiga toxin (Stx)-producing Escherichia coli (STEC) O157:H7 was isolated from six different locations in Hokkaido, Japan. These isolates were negative for sorbitol fermentation but positive for beta-D-glucuronidase (GUD+). They carried eaeA, EHEC-hlyA, pas and etpD genes like typical E. coli O157:H7 and, in addition, st1 and stx2 genes. However, they were shown to lack katP and espP genes that are present in typical STEC O157:H7. All these atypical GUD+ STEC O157:H7 isolates had very similar antimicrobial susceptibilities. Pulsed-field gel electrophoresis analysis with XbaI, SfiI, SwaI, SpeI and NotI indicated that they were identical or closely related to one another. From their phenotypic and genotypic features, these GUD+ STEC O157:H7 isolates may represent a distinct clone among STEC O157.