W254 in furin functions as a molecular gate promoting anti-viral drug binding: Elucidation of putative drug tunneling and docking by non-equilibrium molecular dynamics.

Furins are serine endoproteases that process precursor proteins into their biologically active forms, and they play essential roles in normal metabolism and disease presentation, including promoting expression of bacterial virulence factors and viral pathogenesis. Thus, furins represent vital targets for development of antimicrobial and antiviral therapeutics. Recent experimental evidence indicated that dichlorophenyl (DCP)-pyridine "BOS" drugs (e.g., BOS-318) competitively inhibit human furin by an induced-fit mechanism in which tryptophan W254 in the furin catalytic cleft (FCC) functions as a molecular gate, rotating nearly 180o through a steep energy barrier about its chi-1 dihedral to an "open" orientation, exposing a buried (i.e., cryptic) hydrophobic pocket 1. Once exposed, the non-polar DCP group of BOS-318, and similar halo-phenyl groups of analogs, enter the cryptic pocket, stabilizing drug binding. Here, we demonstrate flexible-receptor docking of BOS-318 (and various analogs) was unable to emulate the induced-fit motif, even when tryptophan was replaced with less bulky phenylalanine or glycine. While either substitution allowed access to the hydrophobic pocket for most ligands tested, optimal binding was observed only for W254, inferring a stabilizing effect of the indole sidechain. Furthermore, non-equilibrium steered molecular dynamics (sMD) in which the bound drugs (or their fragments) were extracted from the FCC did not cause closure of the open W254 gate, consistent with the thermodynamic stability of the open or closed W254 orientations. Finally, interactive molecular dynamics (iMD) revealed two putative conduits of drug entry and binding into the FCC, each coupled with W254 dihedral rotation and opening of the cryptic pocket. The iMD simulations further revealed ligand entry and binding in the FCC is likely driven in part by energy fluxes stemming from disruption and re-formation of ligand and protein solvation shells during drug migration from the solution phase into the FCC.

Malaria in Greece: historical and current reflections on a re-emerging vector borne disease.

Between 2009 and September 2012, locally acquired cases of P. vivax infection were reported in Greece, mostly from the agricultural area of Evrotas, Lakonia (n = 48), but also sporadically from five other regions (n = 14), suggesting that conditions in these areas are favourable for local transmission of malaria. The risk of re-establishment of malaria in Greece will depend on whether the receptivity for disease transmission (presence of the mosquito vector and adequate ecological and climatic factors) and the vulnerability (importation of the parasite in human reservoirs or presence of infected mosquito vectors) continue to be present in the country. The continuous implementation of the integrated preparedness and response plan for malaria that covers all aspects from surveillance and laboratory diagnosis to vector control and the reorganization of public health infrastructures are necessary to prevent transmission and control the disease in the long term. However, the impact of the severe economic crisis on current health-care, public health infrastructures and vector control constitute a great challenge for the future. The current threat of renewed sustained local malaria transmission in Greece (and thus in continental Europe) merits an international response, including financial and technical support, from European and international stakeholders.

Adherence to Mediterranean diet is favorably associated with metabolic parameters in HIV-positive patients with the highly active antiretroviral therapy-induced metabolic syndrome and lipodystrophy.

The objective of the study was to investigate whether closer adherence to a Mediterranean dietary pattern is associated with metabolic aspects of the highly active antiretroviral therapy (HAART)-induced metabolic syndrome (fat redistribution [FR], insulin resistance, dyslipidemia) in HIV-positive patients. This was a cross-sectional study. Two hundred twenty-seven HIV-infected patients were evaluated during a single outpatient visit to the General Clinical Research Center of Beth Israel Deaconess Medical Center. Usual dietary intake and physical activity habits were evaluated; the Mediterranean Diet Score (MedDietScore) was calculated. Dual-energy x-ray absorptiometry, computed tomographic findings, anthropometrics, and data from the study interviews and questionnaires were used for the assessment of body composition using specific criteria. A complete metabolic profile was available for all subjects. In the entire study sample, a weak inverse association was found between insulin resistance, estimated using the homeostasis model assessment, and MedDietScore (standardized beta = -0.15, P = .03). Interaction models revealed that this was largely driven by an inverse association in patients with FR (standardized beta = -0.13, P = .02). Moreover, MedDietScore was positively correlated with high-density lipoprotein cholesterol (standardized beta = 0.15, P = .01) and marginally negatively associated with circulating triglyceride levels (standardized beta = -0.16, P = .13) in this group of patients. Adherence to a Mediterranean dietary pattern was favorably related to cardiovascular risk factors in HIV-positive patients with FR. Further clinical studies are needed to confirm our data in different populations and to explore the underlying mechanisms.

Emergency stenting of a ruptured infected anastomotic femoral pseudoaneurysm.

A 74-year-old man presented with a ruptured infected anastomotic femoral pseudoaneurysm. Due to severe medical comorbidities he was considered unsuitable for conventional surgical management and underwent an emergency endovascular repair with a balloon-expandable covered stent. The pseudoaneurysm was excluded successfully and the patient had an uneventful postoperative recovery with long-term suppressive antimicrobials. He remained well for 10 months after the procedure with no signs of recurrent local or systemic infection and finally died from an acute myocardial infarction. To our knowledge, emergency endovascular treatment of a free ruptured bleeding femoral artery pseudoaneurysm has not been documented before in the English literature. This case illustrates that endovascular therapy may be a safe and efficient alternative in the emergent management of ruptured infected anastomotic femoral artery pseudoaneurysms when traditional open surgery is contraindicated.

Infected femoral artery pseudoaneurysm in drug addicts: the beneficial use of the internal iliac artery for arterial reconstruction.

BACKGROUND: Infected femoral artery pseudoaneurysm (IFAP) is a severe complication in parenteral drug abusers, with difficult and controversial management. Ligation alone without revascularization is frequently associated with later intermittent claudication and limb amputation. Furthermore, arterial reconstruction with a synthetic or venous conduit is limited because of a contaminated field and, often, unavailability of autologous venous grafts. In this study, we present our experience with the internal iliac artery (IIA) as a graft for arterial reconstruction after IFAP excision in these patients. METHODS: Data of 14 consecutive patients who presented with IFAP secondary to parenteral drug abuse from 2001 to 2005 were analyzed. Twelve patients (85.7%) were male. The median age was 27 years (range, 19-42 years). In 13 cases, the IFAP involved the common femoral artery, and in 1 case it involved the profunda femoris artery (PFA). In nine patients, we used the IIA for arterial reconstruction (five as a patch and four as an interposition graft), whereas in two patients the arterial deficit was repaired with a great saphenous vein patch. In two cases, an extra-anatomic bypass with a synthetic polytetrafluoroethylene graft was performed. In one patient, the pseudoaneurysm involved the PFA and was treated with excision and ligation of the PFA. RESULTS: All nine patients who underwent revascularization with the use of IIA were free of claudication symptoms. None of them experienced any perioperative complications, had signs of reinfection, or required limb amputation during the follow-up period (median, 19 months; range, 4-52 months). Regarding the remaining five patients, one died 25 days after surgery because of multiorgan failure, and one underwent reoperation because of proximal anastomotic rupture of a synthetic graft. The latter patient finally underwent a transmetatarsal amputation. CONCLUSIONS: The use of IIA for arterial reconstruction after IFAP excision in drug abusers is safe and effective. These preliminary results indicate that the implementation of this technique offers many advantages compared with traditional treatment options.