On the Cauchy problem for semilinear elliptic equations

We study the Cauchy problem for non-linear (semilinear) elliptic partial differential equations in Hilbert spaces. The problem is severely ill-posed in the sense of Hadamard. Under a weak a priori assumption on the exact solution, we propose a new regularization method for stabilising the ill-posed problem. These new results extend some earlier works on Cauchy problems for nonlinear elliptic equations. Numerical results are presented and discusse

Physical activity and nutrition behaviour outcomes of a cluster-randomized controlled trial for adults with metabolic syndrome in Vietnam

Background: Metabolic syndrome is prevalent among Vietnamese adults, especially those aged 50-65 years. This study evaluated the effectiveness of a 6 month community-based lifestyle intervention to increase physical activity levels and improve dietary behaviours for adults with metabolic syndrome in Vietnam. Methods: Ten communes, involving participants aged 50-65 years with metabolic syndrome, were recruited from Hanam province in northern Vietnam. The communes were randomly allocated to either the intervention (five communes, n = 214) or the control group (five communes, n = 203). Intervention group participants received a health promotion package, consisting of an information booklet, education sessions, a walking group, and a resistance band. Control group participants received one session of standard advice during the 6 month period. Data were collected at baseline and after the intervention to evaluate programme effectiveness. The International Physical Activity Questionnaire - Short Form and a modified STEPS questionnaire were used to assess physical activity and dietary behaviours, respectively, in both groups. Pedometers were worn by the intervention participants only for 7 consecutive days at baseline and post-intervention testing. To accommodate the repeated measures and the clustering of individuals within communes, multilevel mixed regression models with random effects were fitted to determine the impacts of intervention on changes in outcome variables over time and between groups. Results: With a retention rate of 80.8%, the final sample comprised 175 intervention and 162 control participants. After controlling for demographic and other confounding factors, the intervention participants showed significant increases in moderate intensity activity (P = 0.018), walking (P < 0.001) and total physical activity (P = 0.001), as well as a decrease in mean sitting time (P < 0.001), relative to their control counterparts. Significant improvements in dietary behaviours were also observed, particularly reductions in intake of animal internal organs (P = 0.001) and in using cooking oil for daily meal preparation (P = 0.001). Conclusions: The prescribed community-based physical activity and nutrition intervention programme successfully improved physical activity and dietary behaviours for adults with metabolic syndrome in Vietnam. Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12614000811606. Registered on 31 July 201

Glucose and lactate turnover in adults with falciparum malaria: effect of complications and antimalarial therapy

Hypoglycaemia and lactic acidosis are potentially life-threatening, poorly understood sequelae of Plasmodium falciparum infections. We investigated relationships between clinical status, treatment, and glucose and lactate kinetics during management of falciparum malaria in 14 Vietnamese adults. Nine had severe malaria, of whom 4 were administered quinine (Group la) and 5 artesunate (Group 1b). Five uncomplicated cases received artesunate (Group 2). Glucose and lactate turnover were studied on 3 occasions: (i) immediately after initial antimalarial treatment, (ii) at parasite clearance a median of 3 days later, and (iii) at discharge from hospital a median of 9 days post-admission. Steady-state glucose and lactate kinetics were derived from plasma isotopic enrichment during a primed-continuous infusion of D-[6,6-D-2] glucose and a parallel infusion of L-[1-C-13]lactate. Group la patients had the lowest plasma glucose concentrations in the admission study (median [range] 3(.)9 [3(.)6-5(.)1] vs 6(.)3 [4-9(.)7-1] and 4(.)5 [4(.)3-5(.)5] mmol/L in Groups 1b and 2 respectively; P 0.17). This was also the case at parasite clearance and suggested an inappropriate beta cell response. Group la patients had the highest admission lactate production (60 [36-77] vs 26 [21-47] and 22 [4-31] mumol/kg.min in Groups lb and 2 respectively; P < 0.05 vs Group 2). Amongst the 9 severe cases, there was an inverse association between plasma glucose and lactate production at admission and parasite clearance (P < 0.05), but no correlation between admission lactate production and serum bicarbonate (P = 0(.)73). The present data confirm previous studies showing that quinine depresses plasma glucose through stimulation of insulin secretion. It is hypothesized that the low plasma glucose activates Na+,K+-ATPase through increased plasma catecholamine concentrations, leading to accelerated glycolysis and increased lactate production in well-oxygenated tissues. In some severely ill patients with falciparum malaria, a raised plasma lactate on its own may, therefore, be an unreliable index of a developing acidosis

Glucose metabolism in severe malaria: Minimal model analysis of the intravenous glucose tolerance test incorporating a stable glucose label

Basal plasma glucose is usually increased in uncomplicated malaria, implying insulin resistance. If the infection progresses, the risk of hypoglycemia will increase as host glucose production becomes insufficient for host/parasite demand. To assess the relative contribution of insulin-mediated and non-insulin-mediated glucose disposal to plasma glucose levels in severe malaria, we studied six healthy controls (two males and four females; mean age, 38 years) and eight patients with complicated falciparum malaria (five males and three females; mean age, 31 years) who had a frequently sampled intravenous glucose tolerance test (FSIVGTT) in which 10% of the dextrose bolus was 6,6-D-2-glucose. The minimal model was applied to native and labeled plasma glucose and serum insulin profiles over 4 hours postinjection. Basal plasma glucose concentrations in the patients were significantly greater than in the controls (median [range], 6.1 [2.1 to 8.5] v 4.3 [3.9 to 4.7] mmol/L, P = .03). Malaria-associated insulin resistance was confirmed by a lower insulin sensitivity index (SI) in patients (5.6 [2.4 to 17.4] v 16.0 [2.5 to 22.3] x 10(-4).min(-1) per mu U/mL in controls, P = .026). Glucose effectiveness ([SG] the ability of glucose to reduce its own plasma concentration) was higher in the patients (0.015 [0.006 to 0.024] v 0.008 [0.007 to 0.010] min(-1) in controls, P = .019). Glucose disappearance at basal concentration was increased by a median of 42% in severe malaria patients, with the insulin-independent component comprising 81%, versus 67% in controls. Indices of beta-cell function were normal in malaria patients. These data demonstrate that basal plasma glucose utilization is increased approximately 50% in severe malaria, consistent with previously published isotope-turnover studies. Altered SG plays a major role. Prevention and treatment of early hypoglycemia should be based on adequate glucose replacement. Strategies that reduce insulin secretion or effects appear to be of minor importance. Copyright (C) 1997 by W.B. Saunders Company

Do intracerebral cytokine responses explain the harmful effects of dexamethasone in HIV-associated cryptococcal meningitis?

Background The CryptoDex trial showed dexamethasone was associated with poorer clinical outcomes and slower fungal clearance in HIV-associated cryptococcal meningitis. We analysed CSF cytokine concentrations from CrytpoDex participants over the first week of treatment to investigate potential mechanisms of harm and test two hypotheses: dexamethasone reduced pro-inflammatory cytokine concentrations leading to poorer outcomes; and leukotriene A4 hydrolase (LTA4H) genotype (previously associated with dexamethasone responsiveness in tuberculous meningitis) influenced dexamethasone’s clinical impact. Methods We included participants from Vietnam, Thailand, and Uganda. We measured CSF concentrations of IFN-γ, TNF-α, GM-CSF, IL-6, IL-12p70, IL-8, MCP-1, MIP-1α, IL-4, IL-10, and IL-17 from days 1 to 7 of treatment using the Luminex system. We determined LTA4H genotype using a TaqMan genotyping assay of the promoter region SNP rs17525495. We assessed the impact of dexamethasone on cytokine concentration dynamics and the association between cytokine concentration dynamics and fungal clearance with mixed effect models. We measure the influence of LTA4H genotype on outcomes with Cox regression models. Results Dexamethasone increased the rate of TNF-α concentration decline (-0.13 pg/ml/day (95%CI -0.22 to -0.06) p=0.03), which was associated with slower fungal clearance (correlation -0.62 (-0.83 to -0.26)). LTA4H genotype had no statistically significant impact on outcome or response to dexamethasone therapy. Better clinical outcomes were associated with higher baseline concentrations of IFN-γ. Conclusions Dexamethasone may slow fungal clearance and worsen outcomes by increasing the rate of decline of TNF-α concentration

Protective Efficacy of Monoclonal Antibodies Neutralizing Alpha-Hemolysin and Bicomponent Leukocidins in a Rabbit Model of Staphylococcus aureus Necrotizing Pneumonia.

Staphylococcus aureus is a major human pathogen that causes a wide range of infections by producing an arsenal of cytotoxins. We found that passive immunization with either a monoclonal antibody (MAb) neutralizing alpha-hemolysin or a broadly cross-reactive MAb neutralizing Panton-Valentine leukocidin, leukocidin ED, and gamma-hemolysins HlgAB and HlgCB conferred only partial protection, whereas the combination of those two MAbs conferred significant protection in a rabbit model of necrotizing pneumonia caused by the USA300 methicillin-resistant S. aureus epidemic clone