[Circadian and septadian variation in sudden cardiac death : Autopsy registry of the Tunisian North]. / Variation circadienne et hebdomadaire de la mort subite d'origine cardiaque : registre autopsique du nord de la Tunisie.

INTRODUCTION: Several studies have suggested a circadian and septadian pattern of incidence of sudden cardiac death with a morning peak and a Monday peak. OBJECTIVE: To analyze the circadian and septadian pattern of occurrence of sudden cardiac death in the eight northern Tunisian governorates. METHODS: We prospectively collected epidemiological and autopsy data of sudden cardiac death victims occurring in the northern region of Tunisia between January 2013 and December 2019. RESULTS: The population included 1834 men (79.6%) and 468 women (20.4%) with a mean age of 56.5 ± 14 years. Smoking (53.9%) was the most prevalent cardiovascular risk factor. One-fifth (20.9%) of victims had known heart disease, and 3% had a family history of sudden death. ischemic heart disease was the leading cause of sudden death (46.8% of cases). One- fourth (25.7%) of autopsies were negative. Analysis of the circadian pattern of occurrence of sudden cardiac death identified a peak (36.1%, p < 0.001) between midnight and 6 am. This nocturnal excess mortality was significant (p < 0.001) and independent of sex (34.1 % in men and 43.8 % in women) and cause of death (39.3 % of cases of sudden ischemic death and 33.3 % of cases of nonischemic death). Moreover, there was a significant septadian variability in the occurrence of sudden death (p: 0.0015), with a peak on Friday (15.8 %, p: 0.042). CONCLUSION: This study showed a peak of sudden death between midnight and 6 am, and on Fridays, confirming the modification of the classic circadian and septadian pattern of sudden death occurrence. These results may help optimize the deployment of emergency mobile teams and structures during the most vulnerable periods.

Trends of juvenile and adolescent suicides in North Tunisia: a 12-year study.

OBJECTIVES: The aim of our study was to analyze the epidemiological characteristics for suicide methods and factors over a 12-year period among child suicides in Northern Tunisia and to compare juvenile and adolescent suicides. STUDY DESIGN: This is a cross-sectional study. METHODS: We included all child and adolescent suicide cases that took place in the North of Tunisia over a 12 year period (2005-2016). Data were collected from medical records and judicial inquiries and were classified into three sections: sociodemographic data, the circumstances of suicide, and the autopsy findings. Data were then compared between the 'juvenile suicide group' and 'the adolescent suicide group', according to the WHO definition. RESULTS: Casualties were equally males and females, mostly adolescents (74.5%), aged 15 years old on average. Hanging was the most frequent suicidal method. A peak of frequency was observed in 2014. CONCLUSION: Our results suggested to focus, among other preventive measures, on the role of media coverage of child suicides.

[Sudden cardiac death in women, data from the northern Tunisian sudden cardiac-death registry]. / La mort subite cardiaque chez la femme, registre du nord de la Tunisie.

BACKGROUND: Sudden cardiac death is a major public health problem. Epidemiological and clinical differences according to gender have been described in sudden cardiac death. The aim of this study was to examine the gender differences between autopsy findings and circumstance of occurrence associated with sudden cardiac death. METHODS: We prospectively collected epidemiological and autopsy data of victims of sudden cardiac death occurring in the northern governorates of Tunisia between January 2013 and December 2019. Symptoms preceding death, circadian, weekly and seasonal variations of sudden death were also analyzed. RESULTS: The study population included 1834 men and 468 women with a mean age of 56.5±14.2 years. All cardiovascular risk factors except smoking were significantly more frequent among women but ischemic heart disease was the most common cause of death in men (51.3 %, versus 28 %, P<0.001). Women were more likely to have a negative macroscopic autopsy than men (34 % versus 23.6 %, P<0.001). Chest pain preceding sudden death was more frequent in male (24 % versus 13.2 %, P<0.001). In contrast, women were more likely to have dyspnea (8.1 % versus 15.6 %, P<0.001). Sudden death in women occurred indoors more often than in men (63.9 % versus 54.5 %, P<0.001) and also more often during night (midnight to 6 am). We also recorded an excess cardiac mortality in winter in both sexes. CONCLUSIONS: Women had considerably more cardiovascular risk factors and more commonly negative macroscopic autopsy. Death occurred indoors and during night more often than in men.

[Hemodialysis performance in Center East Tunisia: Compliance and adequacy of biological tests (PHCET study 2014)]. / Performance des centres d'hémodialyse au Centre Est Tunisien : conformité et adéquation des examens biologiques (Étude PHCET 2014).

BACKGROUND: Determining the performance level of hemodialysis facilities, including an evaluation of biological tests, is a prerequisite for quality assessment of these healthcare structures. OBJECTIVE: The purpose of this work was to evaluate the compliance and adequacy of biological tests performed in 2014 in Center-East Tunisia hemodialysis units. METHODS: Data were collected using an analysis grid for 15 biological indicators including 11 process items and four results items used to determine the compliance and adequacy rates respectively. RESULTS: This study included 660 hemodialysis patients (sex ratio 1.16; mean age 53.9±15.32 years). A low level of compliance was noted for several biological tests (blood glucose: 0.8%; hemoglobin 34.5%). The rate of adequacy of the biological results was insufficient, especially for anemia (32.7%) and calcium-phosphorus surveillance (41.8%). Intercenter and inter-region variability was noted, both for compliance and for adequacy of biological tests. CONCLUSION: This study demonstrated low compliance of biological tests performed for hemodialysis patients and the non-adequacy of the results obtained. It is thus urgent to institute a quality management system for biological tests performed in hemodialysis units.

Deaths among homeless in northern Tunisia: a 10-year study (2005-2014).

OBJECTIVE: To analyze the victims profile related to death among homeless people. STUDY DESIGN: A descriptive, retrospective, and cross-sectional study. METHODS: We included all deaths among homeless people that occurred during a 10-year period (2005-2014) that were autopsied in the Department of Legal Medicine of the Charles Nicolle Hospital of Tunis. Causes of death were classified according to the International Statistical Classification of Diseases and Related Health Problems 10th Revision. Data were classified in three sections: sociodemographic data, circumstances of death, and autopsy findings. A univariate data analysis was performed. RESULTS: The sex ratio (M/F) was of 7.45. The average age was of 59 years. The majority of deaths (80.9%) occurred in the metropolis of Tunis with a significant occurrence of cases in other governorates after the 2011 revolution (P = 0.002). Deaths occurred more often during winter (34.8%). The bodies were frequently discovered in public places (36.0%) and private locations (34.0%). The deaths of 55.3% of cases were attributed to natural causes, significantly affecting the elderly, whereas the accidental causes (25.7%) were more frequent before the age of 49 years, followed by suicides (3.9%) and homicides (3.3%). CONCLUSIONS: Our study highlighted a phenomenon not yet studied in Tunisia. Our results highlight an urgent need for preventive measures focused on the improvement of healthcare measures among homeless people.

Unexpected infant death secondary to a pulmonary infiltration due to acute myelocytic leukaemia.

Acute myeloid leukaemia (AML) often presents with non-specific symptoms such as fatigue, anaemia or infection. Pulmonary involvement is uncommon in AML during the course of the disease and is usually caused by infection, haemorrhage, leukaemic pulmonary infiltrates and leukostasis. Lung localization of AML is very uncommon and potentially life threatening if not diagnosed and treated rapidly. The authors describe the sudden death of an asymptomatic five-month-infant because of a misdiagnosed lung localization of AML. Autopsy examination followed by histopathological studies showed an extensive leukostasis and extramedullary leukaemic infiltrating the lungs. Special stains and immunohistochemical studies revealed findings consistent with acute myelogenous leukaemia. This case suggests that underlying acute leukaemia should be considered as a cause of flu-like symptoms in infants. Medical personnel are urged to be alert to fever, sore throat, weakness and dyspnea that may be characteristic of serious systemic diseases.

[Prevalence of cardiovascular risk factors in urban and rural communities in the Wilaya of Tlemcen (Algeria): A comparative study]. / Prévalence des facteurs de risque cardiovasculaire au sein des communautés urbaine et rurale dans la Wilaya de Tlemcen (Algérie) : l'étude de deux communes.

BACKGROUND: In Algeria, few studies have been conducted to determine the prevalence of genetic and environmental risk factors of cardiovascular diseases as a function of residence. The objective of this study was therefore to determine the prevalence of cardiovascular risk factors according to sex and age in urban and rural communities in the Wilaya of Tlemcen (Algeria). MATERIAL AND METHODS: A population survey was conducted on a representative sample of 864 individuals aged 20years and over, among inhabitants in urban and rural communes in the Wilaya of Tlemcen. Each subject answered the questionnaire on cardiovascular risk factors, underwent a physical examination and had a blood sample drawn. RESULTS: The prevalence of hypercholesterolemia was 6.6%, it was found to be higher in urban areas (8.4%) than in rural areas (4.6%). The prevalence of low HDL cholesterol levels was higher in urban (28.8%) than rural (23.9%) areas. The prevalence of family history of cardiovascular disease did not differ between the two sexes and between urban (15.7%) and rural (14.0%) areas. The prevalence of hypertension was higher in urban (28.0%) than in rural (16.8%) areas, and was highest among women aged 65 years or older in urban areas (67.3%) and in rural areas (66.6%). The prevalence of diabetes was higher among women living in urban areas (21.4%) compared with rural areas (15.4%). Obesity was much more frequent among women than among men in urban areas (24.7% in women and 9.5% in men) and in rural areas (28.3% in women and 8.3% in men). The prevalence of smoking was 45.8% for men and with no significant variations between urban areas and rural areas. CONCLUSION: The prevalence of cardiovascular risk factors according to sex and age in the two communes are high in two communes in the Wilaya of Tlemcen. However, the prevalence of hypertension, hypercholesterolemia and diabetes were higher in women in urban than in rural areas. This finding focuses attention on the need for measures to reduce the prevalence of these cardiovascular risk factors in these communities. Factors such as sex age and area of residence are indicators to consider when targeting interventions.

Two cases of sudden death due to pulmonary tumor thrombotic microangiopathy caused by occult gastric carcinoma.

We present two cases of occult gastric carcinoma associated to a large pulmonary tumors thrombosis microangiopathy (PTTM). The first case is a 28 years-old man. He was dead due to a respiratory failure. Autopsy showed a whitish indurated mass invading the stomach wall. Histological findings showed a primary "signet ring" gastric adenocarcinoma with pulmonary carcinomatosis and multiple PTTM and a heart metastasis. The second case is a 24 years-old pregnant woman. The main symptoms were nausea and stomach discomfort and they were seen as pregnancy signs. She was dead because of respiratory failure, 10 hours after a vaginal delivery. Autopsy showed the absence of any cause of death related to the delivery and the presence of a whitish indurated mass in the stomach. Histological findings showed a primary "signet ring" gastric adenocarcinoma, with pulmonary carcinomatosis and multiple PTTM.

Elaboration of some signal processing algorithms in ultrasonic techniques: application to materials NDT

In ultrasonic techniques, information on defect characterization possibilities has required more evolved technique development than classical methods. To obtain a high probability of defect detection, these methods use signal-processing algorithms in order to enhance the signal-to-noise ratio. These methods are also used to discriminate between planar and volumetric defects. In this paper, some signal-processing algorithms are developed and implemented on a computer to allow their utilization in real-time processing of ultrasonics NDT results.

No relationship between genetic instability in Bloom's syndrome and DNA hypomethylation of some major repetitive sequences.

Bloom's syndrome (BS) is an autosomal recessive disorder, characterized by a high incidence of cancer at a young age. Cytogenetically, BS cells exhibit a high frequency of chromosomal damage and sister chromatid exchange (SCE). Thus, BS provides a human model of a genetic disorder exhibiting both chromosomal instability and a high incidence of cancer. In addition to its involvement in gene regulation, CpG methylation has recently been suggested to play an important role in the evolution and stability of chromosome structure. We have examined DNA methylation profiles of total DNA and some selected repeated sequences in normal and BS cells. No specific DNA hypomethylation in either total blood or lymphoblastoid cell lines from BS patients has been detected, suggesting that the genomic instability observed in BS is not directly related to a major DNA demethylation of the total CCGG sites, or of Alu or chromosome 1 satellite 2 repeated sequences.

Glutamine synthetase modulation in astrocyte cultures of different mouse brain areas.

Astroglial cells from mouse cerebral hemispheres, cerebellum, olfactory bulbs, and medulla oblongata were grown in the presence of either hormones (hydrocortisone, insulin) or cell second messengers (dBcAMP, dBcGMP). Glutamine synthetase (GS) specific activity, GS protein level, and GS translation were investigated under the effect of these factors. Hydrocortisone produced a simultaneous increase in GS translation, GS level, and activity. This increase was observed in the astrocytes cultured from the four brain areas but at a variable magnitude depending on the area. The hydrocortisone effect appeared at the transcriptional level. Inversely, insulin decreased both the GS activity and the in vitro translated GS. This effect was seen only in the olfactory bulbs and the medulla. DBcAMP increased the GS biological activity only in the cerebral hemisphere cultures. It raised, however, the level of translated GS and GS protein in astrocytes from all the areas, suggesting a post-translational effect for intracellular cAMP. DBcGMP only affected GS in the astrocytes from cerebral hemispheres and the medulla modulating either the GS transcription or the messenger RNA stability. These results suggest specific regulation for GS expression, depending on the brain area from which the cells were dissociated or on the astroglial cell population present in these cultures affecting either the transcription, the mRNA stability, or the biological activity of the protein.

Insulin effect on GABA uptake in astroglial primary cultures.

Astroglial cultures from newborn mouse cerebral cortex contain [125I]Insulin binding sites. Binding was specific, reversible, time dependent and reached equilibrium after 45 min. Insulin analogues compete for this [125I]Insulin binding. Incubation of cerebral cortex astroglial cultures with insulin induced a time- and dose-dependent inhibition of the [3H]GABA high affinity uptake. A decrease in the Vmax rather than an effect on the Km was observed. This effect was dose-dependent and effective at 10(-10) M. Autoradiographic observations on the cell monolayer showed the presence of two groups of cells: one which strongly takes up [3H]GABA and consist in smaller GFAP positive process-bearing cells and another group of much flatter and larger GFAP positive cells which uptake was lower. The smaller stellate cells were apparently the most sensitive to insulin effect. These results: 1) confirm the presence of insulin binding sites on astroglial primary cultures, 2) show an effect of insulin on [3H]GABA high affinity uptake of these cells; this effect being optimal on a stellate-like population of astrocytes, and 3) indicate that insulin may interfere in neuromodulation through astroglial signals.

Glutamine synthetase: a marker of an astroglial subpopulation in primary cultures of defined brain areas.

Primary cultures from various areas of newborn mouse brain were developed and characterized. Enriched astroglial cultures of the cerebral hemispheres, cerebellum, medulla oblongata and olfactory bulbs contained about 80-90% glial fibrillary acidic protein (GFA) immunolabelled cells. These cultures were composed of a majority of flat, 'protoplasmic-like' cells. The aim of this culture model was used: (1) to study glutamine synthetase (GS) activity during in vitro astroglial development; (2) to consider the hydrocortisone effect on GS activity during both growth and maturation periods, and (3) to determine the development of GS immunoreactivity in the cells and eventual GFA and GS expression in these cells. We observed that GS increased during brain maturation in vivo and in vitro, and that addition of hydrocortisone (1 microM, 48 h) to the culture medium induced varying GS activity depending on the developmental stage and the area. In the four areas studied, the number and intensity of GS-immunolabelled cells reached an optimum between 18 and 30 days in vitro. Only about 50-70% of the cell population was GS positive. Double-labelling experiments showed that three groups of cells coexist whatever the considered area. Two expressed both GFA and GS proteins, the last marker at either a low or a high level, and the third was devoid of GS immunoreactivity. Regional differences in GS-specific activity, GS inducibility and GS immunoreactivity exist in the astroglial population, but the factors responsible for these variations are not yet known.

Messenger RNA coding for glutamine synthetase in cerebral hemispheres and astroglial cultures from mouse brain: A developmental study.

Messenger RNAs from mouse brain hemispheres and from an enriched astroglial population of the same area were isolated, characterized and used to study Glutamine Synthetase (GS) processing during postnatal development using a m-RNA stimulated reticulocyte lysate system. The RNA preparations yielded distinct polypeptide products upon translation including high molecular weight species. Polypeptides in the range of 43-55 kDa appeared developmentally regulated in brain hemispheres but not in astroglia. After immunoprecipitation of the translation products with a GS antibody a major monomeric polypeptide was isolated on SDS/PAGE which migrated at the same position as the purified brain GS antigen (43 kDa). The translatable mRNA were optimal in the perinatal period and decreased until 300 days while GS-mRNA increased during the same period of time and closely paralleled the previously described GS activity profile in this brain area reaching an optimum at 15 days. Astroglial mRNAs were optimal at 18 days in vitro and decreased thereafter. The GS-mRNA was much lower in control astroglial cultures than in brain tissue, but in the presence of 10(?6)M hydrocortisone increased all over the growth period. The highest stimulation of GS-mRNA was observed at 18 days whereas the global mRNA decreased in the presence of the hormone. The GS-mRNAs from either 15-day-old brain hemispheres or 18-day in vitro hydrocortisone stimulated cultures were partially purified on a 5-30% linear sucrose gradient. Two GS-mRNAs, which sedimented respectively at 17S and 23S, were characterized. In addition, based on the profile of total proteins translated in vitro, we estimated that GS-mRNA constituted 0.01% of the brain hemisphere fraction and 0.3% in the astroglial hormone stimulated cells.