Interrelationships of adolescent physical activity, screen-based sedentary behaviour, and social and psychological health

Objectives:  

To examine how adolescent physical activity (PA) and screen-based media sedentary behaviours (SBM) relate to psychological and social health and identify cross-national differences in these relationships.     

Associated malformations in patients with esophageal atresia

Esophageal atresia is a common type of congenital malformation. The etiology of esophageal atresia is unclear and its pathogenesis is controversial. Because previous reports have inconsistently noted the type and frequency of malformations associated with esophageal atresia, we conducted this study in a geographically well-defined population, evaluating the birth prevalence of esophageal atresia and associated malformations ascertained between 1979 and 2003 in 334,262 consecutive births. Of the 99 patients with esophageal atresia, 46 (46.5%) had associated malformations. These included patients with chromosomal abnormalities (8 patients, 8%); non-chromosomal recognized syndromes (4 patients), including one each CHARGE syndrome, Fanconi anemia, Fryns syndrome, and Opitz G/BBB syndrome; associations including VACTERL (10 patients), and one schisis; one oculo-auriculo-vertebral spectrum; one malformation complex, a sirenomelia, and non-syndromic multiple congenital anomalies (MCA) (21 patients, 21%). Malformations of the cardiovascular system (24%), urogenital system (21%), digestive system (21%), musculoskeletal system (14%), and central nervous system (7%) were the most common other congenital malformations occurring in patients with esophageal atresia and non-syndromic MCA. We observed a high prevalence of total malformations and specific patterns of malformations associated with esophageal atresia which emphasizes the need to evaluate all patients with esophageal atresia for possible associated malformations. The malformations associated with esophageal atresia could be classified into a recognizable malformation syndrome or pattern in 25 out of 46 patients (54%).     

Carotid atherosclerosis and cognitive decline in patients with Alzheimer's disease

Aim of the study was to explore the correlation between the progression of carotid atherosclerosis and the evolution of cognitive impairment in 66 patients with Alzheimer's disease (AD). They underwent cognitive status evaluation and ultrasonography (US) to investigate carotid arteries intima-media thickness (IMT) and plaque index (PI). After a 12-month follow-up period, neuropsychological and US examinations were repeated to assess the progression of carotid atherosclerosis and of cognitive decline [in terms of changes in Mini Mental State Examination (MMSE) scores]. MMSE score changes were related to baseline IMT (p=0.018), changes in IMT (p<0.001) and PI (p=0.006), and "antihypertensive drug intake" (p<0.001). While the first three variables correlated with increased cognitive impairment, the last one was associated with a reduced extent of MMSE score decline. Results show a link between progression of carotid wall changes and of cognitive decline, and suggest a possible protective role of antihypertensive therapy. Given the potential clinical implications, our preliminary findings could stimulate further investigations into the role of vascular impairment in patients with AD.     

Distinct and overlapping alterations in motor and sensory neurons in a mouse model of spinal muscular atrophy

Motor neuron degeneration is the predominant pathological feature of spinal muscular atrophy (SMA). In patients with severe forms of the disease, additional sensory abnormalities have been reported. However, it is not clear whether the loss of sensory neurons is a common feature in severe forms of the disease, how many neurons are lost and how loss of sensory neurons compares with motor neuron degeneration. We have analysed dorsal root ganglionic sensory neurons in Smn-/-;SMN2 mice, a model of type I SMA. In contrast to lumbar motor neurons, no loss of sensory neurons in the L5 dorsal root ganglia is found at post-natal days 3-5 when these mice are severely paralyzed and die from motor defects. Survival of cultured sensory neurons in the presence of NGF and other neurotrophic factors is not reduced in comparison to wild-type controls. However, isolated sensory neurons have shorter neurites and smaller growth cones, and beta-actin protein and beta-actin mRNA are reduced in sensory neurite terminals. In footpads of Smn-deficient mouse embryos, sensory nerve terminals are smaller, suggesting that Smn deficiency reduces neurite outgrowth during embryogenesis. These data indicate that pathological alterations in severe forms of SMA are not restricted to motor neurons, but the defects in the sensory neurons are milder than those in the motor neurons.     

Transmission in vitro of hepatitis C virus from persistently infected human B-cells to hepatoma cells by cell-to-cell contact

Virus cell-to-cell spread has been reported for many different viruses and may contribute to pathogenesis of viral disease. The role played by cell-to-cell contact in hepatitis C virus (HCV) transmission was studied in vitro by cell co-cultivation experiments. A human lymphoblastoid B-cell line, infected persistently with HCV in vitro (TO.FE(HCV)), was used as HCV donor [Serafino et al., 2003]; recipient cells were the human hepatoma HepG2 cell line. Both cell types were co-cultured for 48 hr to allow the cell-to-cell contacts. The hepatoma HepG2 cells are not permissive to free-virus infection, but they were infected successfully using TO.FE(HCV) cells as source of virus. The kinetics of viral RNA synthesis and the percentage of infected cells were compared in cell-mediated-and cell-free-viral infection. After co-cultivation, a consistent proportion of hepatoma cells replicated HCV and stably expressed viral antigens. Virus produced was infectious as demonstrated by the ability to reinfect fresh B-cells. This cell model shows that permissiveness to HCV infection can be achieved in vitro in non-permissive hepatoma cells by direct cell-to-cell contacts with infected human B-cells. This mechanism of virus spread may also play a pathogenic role in vivo.     

Natural IgE production in the absence of MHC Class II cognate help

IgE induction by parasites and allergens is antigen driven and cognate T cell help dependent. We demonstrate that spontaneously produced IgE in T cell-deficient and germ-free wild-type (wt) mice is composed of natural specificities and induced by a mechanism independent of MHC class II (MHC II) cognate help. This does not require secondary lymphoid structures or germinal center formation, although some bystander T cell-derived IL-4 is necessary. The pathway of spontaneous IgE production is not inhibited by regulatory T cells and increases with age to constitute significant serum concentrations, even in naive animals.     

Contraception at the time of abortion: high-risk time or high-risk women?

BACKGROUND: Despite the widespread use of highly effective contraception in France, the incidence of abortion is high. A retrospective population-based cohort study was designed to analyse women's contraceptive history. METHOD: We compared the contraceptive use of 163 women, whose last pregnancy ended in abortion, 6 months before, at the time of, 1 month and 6 months after the event with that of 1787 women who had never had an abortion. RESULTS: A total of 46% of women who experienced an abortion used a highly effective form of contraception 6 months before the event (versus 76% among women who had never had an abortion, P < 0.001). This proportion dropped to 33% at the time of the abortion and increased to 71%, 1 month after. In addition, 50% of women who had an abortion had changed their contraceptive method in the 6 months before the event (compared with 16% in the 6 months before the interview in women who had not had an abortion, P < 0.001). Women with socially deprived backgrounds were less likely to use a highly effective contraception after an abortion. CONCLUSIONS: Abortion is a good opportunity for intervention, but especially so for socially disadvantaged women. It is essential to draw the attention of prescribers and women to the higher risk of contraceptive failure at the start of use of a method.     

Contrasting roles of macrophages and dendritic cells in controlling initial pulmonary Brucella infection

Control of pulmonary pathogens constitutes a challenging task as successful immune responses need to be mounted without damaging the lung parenchyma. Using immunofluorescence microscopy and flow cytometry, we analyzed in the mouse the initial innate immune response that follows intranasal inoculation of Brucella abortus. Bacteria were absent from parenchymal dendritic cells (DC) but present in alveolar macrophages in which they replicated. When the number of alveolar macrophages was reduced prior to Brucella infection, small numbers of pulmonary DC were infected and a massive recruitment of TNF-α- and iNOS-producing DC ensued. Coincidentally, Brucella disseminated to the lung-draining mediastinal lymph nodes (LN) where they replicated in both migratory DC and migratory alveolar macrophages. Together, these results demonstrate that alveolar macrophages are critical regulators of the initial innate immune response against Brucella within the lungs and show that pulmonary DC and alveolar macrophages play rather distinct roles in the control of microbial burden.