Efficacy of malaria prophylaxis in American and Swiss travelers to Kenya

The protective effect of malaria chemoprophylaxis with either Fansidar (pyrimethamine-sulfadoxine) or chloroquine was estimated by determining the attack rates of Plasmodium falciparum infections acquired in Kenya and imported by U.S. and Swiss travelers who had used no chemoprophylaxis, who had used only chloroquine for prophylaxis, and who had used Fansidar weekly, either alone or in combination with chloroquine. The estimated attack rates were almost identical in U.S. and Swiss travelers. The attack rate per 100,000 travelers averaged 280 in those who did not use chemoprophylaxis, 162 in those who took 4-aminoquinolines (P greater than .05), and 27 in those who used Fansidar for prophylaxis (P less than .001). Non-immune travelers to Kenya have an appreciable risk of acquiring a P. falciparum infection and need to be informed of current guidelines for chemoprophylaxis. The changing drug susceptibility patterns in Africa require continuous evaluation of the efficacy of recommended drug regimens for malaria prophylaxis.     

X-Nuclei NMR Self-Diffusion Studies in Mesoporous Silica Foam and Microporous MOF CuBTC

A standard X-observe NMR probe was equipped with a z-gradient coil to enable high-sensitivity pulsed field gradient NMR diffusion studies of Li⁺ and Cs⁺ cations of aqueous salt solutions in a high-porosity mesocellular silica foam (MCF) and of CO₂ adsorbed in metal-organic frameworks (MOF). The coil design and the necessary probe modifications, which yield pulsed field gradients of up to ±16.2 Tm^-1, are introduced. The system was calibrated at ²H resonance frequency and successfully applied for diffusion studies at ⁷Li, ²³Na, ¹³C and ¹³³Cs frequencies. Significant reductions of the diffusivities of the cations in LiCl_ac and CsCl_ac solution introduced into MCFs are observed. By comparison of the diffusion behavior with the bulk solutions, a tortuosity of the silica foam of 4.5 ± 0.6 was derived. Single component self-diffusion of CO₂ and CH₄ (measured by ¹H NMR) as well as self-diffusion of the individual components in CO₂/CH₄ mixtures was studied in the MOF CuBTC. The experimental results confirm high mobilities of the adsorbed gases and trends for diffusion separation factors predicted by MD simulations.     

Skin lesions,malaise, and heart failure in a renal transplant recipient

A male Caucasian patient developed nodular erythematous skin lesions, malaise, and clinical signs of progressive heart failure 4 months after renal transplantation. Bronchoscopy with bronchoalveolar lavage performed for a small infiltrate seen on a computed tomography scan revealed Trypanosoma, which had at this point not been suspected as a cause. Parasitemia was present, and reactivation rather than transmission of Chagas' disease was established by performing polymerase chain reaction and serology in the donor and recipient. Treatment with benznidazole and allopurinol successfully reduced parasitemia, but the clinical course was fatal owing to progression of severe myocarditis. The patient had never lived in an endemic area, but had an extensive travel history in South America. The last visit was more than 5 years before transplantation. In non‐endemic countries (United States, Europe), reactivation after transplantation has only been very rarely reported. Given the rising numbers of transplantations in patients with a migration background and extensive travel histories, specific screening procedures have to be considered.     

Obesity and addiction: can a complication of surgery help us understand the connection?

Obesity is a multifactorial, chronic disease that has proven difficult to treat. An increased understanding of aetiological mechanisms is critical to the development of more effective obesity prevention and treatment strategies. A growing body of empirical evidence has demonstrated parallels between obesity, overeating and substance abuse, including shared behavioural, psychological and neurophysiological factors implicated in the excessive intake of both food and substances of abuse. Several different lines of research have recently emerged that hold the potential to shed light on the connection between obesity, food reward and addiction, with studies examining changes in alcohol use/misuse after weight loss surgery providing a particularly interesting perspective on these interrelationships. However, these lines of investigation have proceeded in relative isolation, and relevant research findings have yet to be integrated in a synthesized, comprehensive manner. To provide an opportunity to achieve such a synthesis, a scientific symposium was convened at the Radcliffe Institute in Cambridge, Massachusetts. Invited participants were researchers working in diverse domains related to the intersection between obesity and addiction. Extensive discussion was generated suggesting novel research directions. In this article, we summarize and synthesize the symposium participants' ongoing research in this area, incorporating additional relevant research holding potential clues regarding the connections between obesity, weight loss surgery and addiction.     

Predictors for long‐term survival after transcatheter edge‐to‐edge mitral valve repair

Objectives

To determine predictors for long‐term outcome in high‐risk patients undergoing transcatheter edge‐to‐edge mitral valve repair (TMVR) for severe mitral regurgitation (MR).

Background

There is no data on predictors of long‐term outcome in high‐risk real‐world patients.

Methods

From August 2009 to April 2011, 126 high‐risk patients deemed inoperable were treated with TMVR in two high‐volume university centers.

Results

MR could be successfully reduced to grade ≤2 in 92.1% of patients (116/126 patients). Long‐term clinical follow‐up up to 5 years (95.2% follow‐up rate) revealed a mortality rate of 35.7% (45/126 patients). Repeat mitral valve treatment (surgery or intervention) was needed in 19 patients (15.1%). Long‐term clinical improvement was demonstrated with 69% of patients being in NYHA class ≤II. In a multivariable Cox regression analysis, the post‐procedural grade of MR (hazard ratio [HR] 1.55 per grade, P = 0.035), the left ventricular ejection fraction (HR 0.58 for difference between 75th and 25th percentile, P = 0.031) and the glomerular filtration rate (HR 0.33 for 75th vs 25th percentile, P < 0.001) were independent predictors for long‐term mortality. Patients with primary MR and a post‐procedural MR grade ≤1 had the most favorable long‐term outcome.

Conclusions

This study determines predictors of long‐term clinical outcome after TMVR and demonstrates that the grade of residual MR determines long‐term survival. Our data suggest that it might be of benefit reducing residual MR to the lowest possible MR grade using TMVR—especially in selected high‐risk patients with primary MR who are not considered as candidates for surgical MVR.

     

Prospective multicentre study of risk factors associated with delayed healing of recurrent duodenal ulcers (RUDER). RUDER Study Group.

Risk factors for delayed duodenal ulcer healing during treatment with ranitidine (300 mg daily) were examined in a multicentre German study of 1923 patients with endoscopically proved, recurrent duodenal ulceration. Healing rates, per protocol, were 39.5% at two weeks, 70.9% at four weeks, and 93.2% at eight weeks. Prospective testing of five, predefined risk factors indicated that smoking (p = 0.0039) was associated with a decreased healing rate at two weeks. Frequent prior recurrence (p = 0.464), a heavy physical workload (p = 0.145), and psychological stress (p = 0.062) were not associated with a decreased healing rate and there were too few patients at risk to allow assessment of the effect of regular NSAID intake. Exploratory analysis identified prior slow healing, a large ulcer, multiple ulcers, and prior ulcer complications, in addition to smoking, as markers of slow healing. In the absence of these risk factors, the mean healing time was 3.3 weeks (95% confidence interval 3.0, 3.5), rising to 3.7 weeks (3.5, 3.9) for one, 4.4 weeks (4.1, 4.7) for two, and 5.1 weeks (4.5, 5.6) for three to five risk factors. Delayed duodenal ulcer healing is associated with multiple factors whose effect is cumulative; for patients with two or more of five easily identified risk factors, more than four weeks' treatment with a histamine H2 receptor antagonist is required to achieve ulcer healing.     

Predictive Value of the Residual SYNTAX Score in Patients With Cardiogenic Shock

BackgroundIn hemodynamically stable patients, complete revascularization (CR) following percutaneous coronary intervention (PCI) is associated with a better prognosis in chronic and acute coronary syndromes.ObjectivesThis study sought to assess the extent, severity, and prognostic value of remaining coronary stenoses following PCI, by using the residual SYNTAX score (rSS), in patients with cardiogenic shock (CS) related to myocardial infarction (MI).MethodsThe CULPRIT-SHOCK (Culprit Lesion Only Percutaneous Coronary Intervention [PCI] Versus Multivessel PCI in Cardiogenic Shock) trial compared a multivessel PCI (MV-PCI) strategy with a culprit lesion–only PCI (CLO-PCI) strategy in patients with multivessel coronary artery disease who presented with MI-related CS. The rSS was assessed by a central core laboratory. The study group was divided in 4 subgroups according to tertiles of rSS of the participants, thereby isolating patients with an rSS of 0 (CR). The predictive value of rSS for the 30-day primary endpoint (mortality or severe renal failure) and for 30-day and 1-year mortality was assessed using multivariate logistic regression.ResultsAmong the 587 patients with an rSS available, the median rSS was 9.0 (interquartile range: 3.0 to 17.0); 102 (17.4%), 100 (17.0%), 196 (33.4%), and 189 (32.2%) patients had rSS = 0, 0 < rSS ≤5, 5 < rSS ≤14, and rSS >14, respectively. CR was achieved in 75 (25.2%; 95% confidence interval [CI]: 20.3% to 30.5%) and 27 (9.3%; 95% CI: 6.2% to 13.3%) of patients treated using the MV-PCI and CLO-PCI strategies, respectively. After multiple adjustments, rSS was independently associated with 30-day mortality (adjusted odds ratio per 10 units: 1.49; 95% CI: 1.11 to 2.01) and 1-year mortality (adjusted odds ratio per 10 units: 1.52; 95% CI: 1.11 to 2.07).ConclusionsAmong patients with multivessel disease and MI-related CS, CR is achieved only in one-fourth of the patients treated using an MV-PCI strategy. and the residual SYNTAX score is independently associated with early and late mortality.     

Hypoxia-induced increase in the production of extracellular matrix proteins in systemic sclerosis

OBJECTIVE: Insufficient angiogenesis with tissue ischemia and accumulation of extracellular matrix are hallmarks of systemic sclerosis (SSc). Based on the severely decreased oxygen levels in the skin of patients with SSc, we aimed to investigate the role of hypoxia in the pathogenesis of SSc. METHODS: Subtractive hybridization was used to compare gene expression in dermal fibroblasts under hypoxic and normoxic conditions. Dermal fibroblasts were further characterized by exposure to different concentrations of oxygen and for different time periods as well as by interference with hypoxia-inducible factor 1alpha (HIF-1alpha). The systemic normobaric hypoxia model in mice was used for in vivo analyses. RESULTS: Several extracellular matrix proteins and genes involved in extracellular matrix turnover, such as thrombospondin 1, proalpha2(I) collagen, fibronectin 1, insulin-like growth factor binding protein 3, and transforming growth factor beta-induced protein, were induced by hypoxia in SSc and healthy dermal fibroblasts. The induction of these genes was time- and dose-dependent. Experiments with HIF-1alpha-knockout mouse embryonic fibroblasts, deferoxamine/cobalt ions as chemical stabilizers of HIF-1alpha, and HIF-1alpha small interfering RNA consistently showed that extracellular matrix genes are induced in dermal fibroblasts by HIF-1alpha-dependent, as well as HIF-1alpha-independent, mechanisms. Using the systemic normobaric hypoxia mouse model, we demonstrated that dermal hypoxia leads to the induction of the identified extracellular matrix genes in vivo after both short exposure and prolonged exposure to hypoxia. CONCLUSION: These data show that hypoxia contributes directly to the progression of fibrosis in patients with SSc by increasing the release of major extracellular matrix proteins. Targeting of hypoxia pathways might therefore be of therapeutic value in patients with SSc.