Subject(s)
Contrast Media/administration & dosage , Coronary Circulation , Echocardiography/methods , Heart/diagnostic imaging , Myocardial Perfusion Imaging/methods , Phospholipids/administration & dosage , Sulfur Hexafluoride/administration & dosage , Blood Flow Velocity , Feasibility Studies , Healthy Volunteers , Humans , Microbubbles , Predictive Value of TestsABSTRACT
The chemistry of aqueous fluids controls the transport and exchange-the cycles-of metals and volatile elements on Earth. Subduction zones, where oceanic plates sink into the Earth's interior, are the most important geodynamic setting for this fluid-mediated chemical exchange. Characterizing the ionic speciation and pH of fluids equilibrated with rocks at subduction zone conditions has long been a major challenge in Earth science. Here we report thermodynamic predictions of fluid-rock equilibria that tie together models of the thermal structure, mineralogy and fluid speciation of subduction zones. We find that the pH of fluids in subducted crustal lithologies is confined to a mildly alkaline range, modulated by rock volatile and chlorine contents. Cold subduction typical of the Phanerozoic eon favours the preservation of oxidized carbon in subducting slabs. In contrast, the pH of mantle wedge fluids is very sensitive to minor variations in rock composition. These variations may be caused by intramantle differentiation, or by infiltration of fluids enriched in alkali components extracted from the subducted crust. The sensitivity of pH to soluble elements in low abundance in the host rocks, such as carbon, alkali metals and halogens, illustrates a feedback between the chemistry of the Earth's atmosphere-ocean system and the speciation of subduction zone fluids via the composition of the seawater-altered oceanic lithosphere. Our findings provide a perspective on the controlling reactions that have coupled metal and volatile cycles in subduction zones for more than 3 billion years7.
ABSTRACT
OBJECTIVE: To compare H1N1 (2009) influenza A infection characteristics between transplant recipient patients and non-transplanted patients. To assess the evolution of transplanted patients up to 6 months following infection. METHODS: Patients diagnosed with confirmed influenza A infection from three Parisian transplant centers between September 1st, 2009 and February 15th, 2010. Clinical symptoms, biological, and radiological findings, and management were analysed and retrospectively compared between transplanted (T) and non-transplanted patients (NT). The evolution was assessed by a follow-up questionnaire, CT results 1 to 3 months after influenza infection and FEV1 variation. RESULTS: Seventy patients were included. Thirteen patients had an allograft (lung: eight, kidney: four, stem cells: one): (1) hospitalization: 100% (13 out of 13) in group T, 54% (31 out of 57) in group NT (P=0.0013); (2) pneumonia: 62% (eight out of 13) in group T, 26% (eight out of 57) in group NT (P=0.004); (3) mortality rate among hospitalized patients: 7.7% (one out of 13) in the group T, 9.7% (three out of 57) in group NT (P=NS); (4) chest CT scan abnormalities remained in four lung transplanted patients; (5) a minimum 10% decrease in FEV1 was detected in four lung transplant recipients. CONCLUSION: Our results suggest that H1N1(2009) influenza A infection in transplant recipient patients compared to non-transplanted patients: (1) more often leads to hospitalization; (2) is more frequently associated with pneumonia; (3) is responsible for a persistent graft functional impairment in lung transplant recipients; (4) has a low mortality rate similar to admitted non-transplanted patients.
Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza, Human , Organ Transplantation , Postoperative Complications , Adult , Female , Humans , Influenza, Human/diagnosis , Influenza, Human/epidemiology , Male , Middle Aged , Postoperative Complications/diagnosis , Postoperative Complications/epidemiology , Retrospective StudiesABSTRACT
The acute insulin response to i.v. glucose (AIRG) was evaluated in 344 first-degree relatives of patients with Type 1 diabetes. In 318 relatives aged 3 to 48 years without islet cell antibody and insulin autoantibody, correlations (p < 0.0006) were found between age and fasting insulinaemia, fasting glycaemia, or AIRG, with a peak during puberty. Assuming that these relatives without islet cells and insulin auto-antibodies have a low risk of developing Type 1 diabetes, we provided a "standard age-related chart" for AIRG with a "low" AIRG defined as a value below the 1st percentile for each pubertal stage. Using these cut-off points, predictive characteristics of a low AIRG for progression towards diabetes within 6 years were analysed. Four relatives developed diabetes and one displayed impaired oral glucose tolerance. Four out of these 5 subjects had islet cell and insulin auto-antibodies, but the other one was negative for these markers. Three of these 5 subjects had low AIRG at entry (30, 24 and 1 months before diabetes, respectively). The two others displayed a steady progressive decline (p < 0.02) of age-related during the follow-up before impaired oral glucose tolerance and diabetes appeared (rate of decline: 15 microU/ml/year). Thus, independently of the presence of islet cell antibodies, the predictive value of a low age-related AIRG during the follow-up is greater than the single low AIRG at entry.(ABSTRACT TRUNCATED AT 250 WORDS)
