A 1-Year Prospective French Nationwide Study of Emergency Hospital Admissions in Children and Adults with Primary Immunodeficiency.

PURPOSE: Patients with primary immunodeficiency (PID) are at risk of serious complications. However, data on the incidence and causes of emergency hospital admissions are scarce. The primary objective of the present study was to describe emergency hospital admissions among patients with PID, with a view to identifying "at-risk" patient profiles. METHODS: We performed a prospective observational 12-month multicenter study in France via the CEREDIH network of regional PID reference centers from November 2010 to October 2011. All patients with PIDs requiring emergency hospital admission were included. RESULTS: A total of 200 admissions concerned 137 patients (73 adults and 64 children, 53% of whom had antibody deficiencies). Thirty admissions were reported for 16 hematopoietic stem cell transplantation recipients. When considering the 170 admissions of non-transplant patients, 149 (85%) were related to acute infections (respiratory tract infections and gastrointestinal tract infections in 72 (36%) and 34 (17%) of cases, respectively). Seventy-seven percent of the admissions occurred during winter or spring (December to May). The in-hospital mortality rate was 8.8% (12 patients); death was related to a severe infection in 11 cases (8%) and Epstein-Barr virus-induced lymphoma in 1 case. Patients with a central venous catheter (n = 19, 13.9%) were significantly more hospitalized for an infection (94.7%) than for a non-infectious reason (5.3%) (p = 0.04). CONCLUSION: Our data showed that the annual incidence of emergency hospital admission among patients with PID is 3.4%. The leading cause of emergency hospital admission was an acute infection, and having a central venous catheter was associated with a significantly greater risk of admission for an infectious episode

STRUCTURE OF THE SILICIDE/Si, SiO2/Si INTERFACE ANALYSED USING HIGH RESOLUTION TRANSMISSION ELECTRON MICROSCOPY

This paper is a kind of over- view of the problems which have to be solved in order to determine an interface structure. The first question is to be able to interpret the micrographs knowing that the dynamical interaction between electron wave and atomic potential is highly dependent on the crystal structure. Differences between centrosymmetric and non-centrosymmetyric crystals are underlined. The example which is treated is ErSi2, and the ErSi2/Si interface is analysed. The second problem is the thickness variation at the interface vicinity ; this is shown to imply contrast variations which can be interpreted as the presence of a thin film between the substrate and the over layer. Finally it is shown how high resolution images are a necessary complement to determine microcrystallite structures, when they are too few and small to be analysed using X-Ray diffraction. The example is SiO2 precipitates grown in amorphous SiO2 during ultra dry oxidation