Synchronization of Circadian Per2 Rhythms and HSF1-BMAL1:CLOCK Interaction in Mouse Fibroblasts after Short-Term Heat Shock Pulse

Circadian rhythms are the general physiological processes of adaptation to daily environmental changes, such as the temperature cycle. A change in temperature is a resetting cue for mammalian circadian oscillators, which are possibly regulated by the heat shock (HS) pathway. The HS response (HSR) is a universal process that provides protection against stressful conditions, which promote protein-denaturation. Heat shock factor 1 (HSF1) is essential for HSR. In the study presented here, we investigated whether a short-term HS pulse can reset circadian rhythms. Circadian Per2 rhythm and HSF1-mediated gene expression were monitored by a real-time bioluminescence assay for mPer2 promoter-driven luciferase and HS element (HSE; HSF1-binding site)-driven luciferase activity, respectively. By an optimal duration HS pulse (43°C for approximately 30 minutes), circadian Per2 rhythm was observed in the whole mouse fibroblast culture, probably indicating the synchronization of the phases of each cell. This rhythm was preceded by an acute elevation in mPer2 and HSF1-mediated gene expression. Mutations in the two predicted HSE sites adjacent (one of them proximally) to the E-box in the mPer2 promoter dramatically abolished circadian mPer2 rhythm. Circadian Per2 gene/protein expression was not observed in HSF1-deficient cells. These findings demonstrate that HSF1 is essential to the synchronization of circadian rhythms by the HS pulse. Importantly, the interaction between HSF1 and BMAL1:CLOCK heterodimer, a central circadian transcription factor, was observed after the HS pulse. These findings reveal that even a short-term HS pulse can reset circadian rhythms and cause the HSF1-BMAL1:CLOCK interaction, suggesting the pivotal role of crosstalk between the mammalian circadian and HSR systems

Quality of perinatal death registration. A study in Hainaut, Belgium.

The quality of national perinatal mortality statistics was evaluated from a survey in nine maternity hospitals in Hainaut, Belgium (total births: 7862). The overall completeness of perinatal death registration was 86%. Under-registration was especially frequent in low birth weight babies. In 69% of cases, the birth weight value reported on death certificates was in exact agreement with the value in hospital records. Using detailed categories of causes, there was, in 37% of cases, agreement between the underlying cause on death certificates and the main cause identified in hospital records. Using gross categories of causes, the level of agreement was 56%. Disagreement was mostly due to the lack of specificity of the underlying cause on death certificates. The authors suggest ways to improve the quality of registration

Mortality in Meningococcal Disease in Belgium

A survey of children admitted with meningococcal disease to 53 paediatric units in Belgium between 1975 and 1979 was made in order to assess the case mortality rate (CMR) and to identify risk factors associated with death. A total of 309 cases (226 bacteriologically confirmed and 83 unconfirmed) was recorded. The overall CMR was 6·1 per cent. It was 4·4 for bacteriologically confirmed cases and 10·8 for unconfirmed cases. The CMR was higher for septicaemia without meningitis (22·2 per cent) than for meningitis with or without signs of septicaemia (3·4 per cent). The risk of death was not related to the sex or nationality of the patients. Age was a major determinant of the CMR, independently of the clinical picture. The highest risk of death was in children under one year of age. Poor socio-economic conditions were a significant risk factor. Failure to recognise the severity of the disease by some poorly educated mothers, and the admission of the patient to a hospital lacking adequate facilities for managing severely affected children, were the two significant causes of delay of adequate treatment. © 1984 The British Society for the Study of Infection.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Meningococcal Disease in Belgium - Secondary Attack Rate Among Household, Day-care Nursery and Pre-elementary School Contacts

During a recrudescence of meningococcal disease mainly due to serogroup B, 1913 notified cases were investigated in Belgium from 1971 to 1976. From 1971 to 1973, 76 secondary cases were reported out of a total of 1455 cases (5·2 per cent); and from 1974 to 1976, nine secondary cases were reported of a total of 458 cases (2·0 per cent). Seventy per cent of the secondary cases occurred within seven days after the Index case. The 4·7 per cent fatality rate among secondary cases was lower than the 9·8 per cent fatality rate among primary cases. The estimated secondary attack rate was 685 per 100 000 among household contacts, 404 per 100 000 among day-care nursery contacts and 77 per 100 000 among pre-elementary school contacts. These attack rates were significantly higher (P < 0·001) than the incidence rates in the corresponding age-groups in the general community, indicating the need for prophylaxis in these contacts. © 1981 The British Society for the Study of Infection.SCOPUS: ar.jinfo:eu-repo/semantics/publishe