16 research outputs found

    Usefulness of Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry in the Characterization of Leishmania Strains Causing Tegumentary Leishmaniasis in Bolivia versus hsp70 Gene Sequencing

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    Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is a proteomic technique with proven efficiency in the identification of microorganisms, such as bacteria, fungi, and parasites. The present study aimed to evaluate the usefulness of MALDI-TOF MS for the characterization of Leishmania species circulating in Bolivia using hsp70 gene sequencing as a reference technique. 55 Leishmania strains that were isolated from patients with tegumentary leishmaniasis were analyzed. MALDI-TOF MS identified two species of the L. braziliensis complex (L. braziliensis, n = 26; L. braziliensis outlier, n = 18), one species of the L. guyanensis complex (L. guyanensis, n = 1), one species of the L. lainsoni complex (L. lainsoni, n = 2), and two species of the complex (, n = 5; and L. garnhami, n = 3). All of the strains were correctly identified at the subgenus, genus, and complex level, but 10 of them (18%) were misidentified as other species within the same complex by the hsp70 gene sequencing, with 7 of these corresponding to possible hybrids. Thus, one L. braziliensis corresponded to L. peruviana, two L. braziliensis corresponded to L. braziliensis / L. peruviana possible hybrids, two corresponded to , and three L. garnhami and two corresponded to / possible hybrids. Accordingly, MALDI-TOF MS could be used as an alternative to molecular techniques for the identification of Leishmania spp., as it is low cost, simple to apply, and able to quickly produce results. In Bolivia, its application would allow for the improvement of the management of patient follow-ups, the updating of the epidemiological data of the Leishmania species, and a contribution to the control of tegumentary leishmaniasis. IMPORTANCE The objective of the study was to evaluate the usefulness of MALDI-TOF MS for the characterization of Leishmania species circulating in Bolivia, in comparison with the sequencing of the hsp70 gene. In our study, all of the isolates could be identified, and no misidentifications were observed at the complex level. Although the equipment implies a high initial investment in our context, MALDI-TOF MS can be used in different areas of microbiology and significantly reduces the cost of testing. Once the parasite culture is obtained, the technique quickly yields information by accessing a free database that is available online. This would allow for the improvement of the management of patients and follow-ups, the updating of the epidemiological data of the species, and a contribution to the control of tegumentary leishmaniasis in Bolivia. Likewise, it can be used to determine a specific treatment to be given, according to the causal species of Leishmania, when there are protocols in this regard in the area

    Topological character of hydrodynamic screening in suspensions of hard spheres: an example of universal phenomenon

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    Although in the case of polymer solutions the existence of hydrodynamic screening is considered as established, use of the same methods for suspensions of hard spheres so far have failed to produce similar results. In this work we reconsider this problem. Using superposition of topological, combinatorial and London-style qualitative arguments, we prove the existence of screening in suspensions. We show that the nature of hydrodynamic screening in suspensions is analogous to that known for the Meissner effect in superconductors. The extent of screening depends on volume fraction of hard spheres. The zero volume fraction limit corresponds to the normal state. The case of finite volume fractions-to the mixed state typical for superconductors of the second kind. Such a state is becoming fully "superconducting" at some critical volume fraction for which the (zero frequency) relative viscosity diverges. Our analytical results describing this divergence are in accord with known scaling results obtained by Brady and Bicerano et al which are well supported by experimental data. We provide theoretical explanation of the divergence of relative viscosity in terms of a topological-type transition which mathematically can be made isomorphic to the more familiar Bose-Einstein condensation transition. Because of this, the methods developed in this work are not limited to suspensions only. In concluding section we mention other applications of the developed formalism ranging from turbulence and magnetohydrodynamics to high temperature superconductors, QCD, string models, etc.Comment: 49 page

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    Treatment of adult chronic indeterminate Chagas disease with benznidazole and three E1224 dosing regimens: a proof-of-concept, randomised, placebo-controlled trial

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    Background: Chagas disease is a major neglected vector-borne disease. In this study, we investigated the safety and efficacy of three oral E1224 (a water-soluble ravuconazole prodrug) regimens and benznidazole versus placebo in adult chronic indeterminate Chagas disease. Method: In this proof-of-concept, double-blind, randomised phase 2 clinical trial, we recruited adults (18–50 years) with confirmed diagnosis of Trypanosoma cruzi infection from two outpatient units in Bolivia. Patients were randomised with a computer-generated randomisation list, which was stratified by centre and used a block size of ten. Patients were randomly assigned (1:1:1:1:1) to five oral treatment groups: high-dose E1224 (duration 8 weeks, total dose 4000 mg), low-dose E1224 (8 weeks, 2000 mg), short-dose E1224 (4 weeks + 4 weeks placebo, 2400 mg), benznidazole (60 days, 5 mg/kg per day), or placebo (8 weeks, E1224-matched tablets). Double-blinding was limited to the E1224 and placebo arms, and assessors were masked to all treatment allocations. The primary efficacy endpoint was parasitological response to E1224 at the end of treatment, assessed by PCR. The secondary efficacy endpoints were parasitological response to benznidazole at end of treatment, assessed by PCR; sustainability of parasitological response until 12 months; parasite clearance and changes in parasite load; incidence of conversion to negative response in conventional and non-conventional (antigen trypomastigote chemiluminescent ELISA [AT CL-ELISA]) serological response; changes in levels of biomarkers; and complete response. The primary analysis population consisted of all randomised patients by their assigned treatment arms. This trial is registered with ClinicalTrials.gov, number NCT01489228. Findings: Between July 19, 2011, and July 26, 2012, we screened 560 participants with confirmed Chagas disease, of whom 231 were enrolled and assigned to high-dose E1224 (n=45), low-dose E1224 (n=48), short-dose E1224 (n=46), benznidazole (n=45), or placebo (n=47). Parasite clearance was observed with E1224 during the treatment phase, but no sustained response was seen with low-dose and short-dose regimens, whereas 13 patients (29%, 95% CI 16·4–44·3) had sustained response with the high-dose regimen compared with four (9%, 2·4–20·4) in the placebo group (p<0·0001). Benznidazole had a rapid and sustained effect on parasite clearance, with 37 patients (82%, 67·9–92·0) with sustained response at 12-month follow-up. After 1 week of treatment, mean quantitative PCR repeated measurements showed a significant reduction in parasite load in all treatment arms versus placebo. Parasite levels in the low-dose and short-dose E1224 groups gradually returned to placebo levels. Both treatments were well tolerated. Reversible, dose-dependent liver enzyme increases were seen with E1224 and benznidazole. 187 (81%) participants developed treatment-emergent adverse events and six (3%) developed treatment-emergent serious adverse events. Treatment-emergent adverse events were headaches, nausea, pruritus, peripheral neuropathy, and hypersensitivity. Interpretation: E1224 is the first new chemical entity developed for Chagas disease in decades. E1224 displayed a transient, suppressive effect on parasite clearance, whereas benznidazole showed early and sustained efficacy until 12 months of follow-up. Despite PCR limitations, our results support increased diagnosis and access to benznidazole standard regimen, and provide a development roadmap for novel benznidazole regimens in monotherapy and in combinations with E1224. Funding: Drugs for Neglected Diseases initiative.Fil: Torrico, Faustino. Universidad Mayor de San Simon Bolivia; Bolivia. Fundación Ceades; BoliviaFil: Gascon, Joaquim. Instituto de Salud Global de Barcelona; EspañaFil: Ortiz, Lourdes. Universidad Autónoma Juan Misael Saracho de Tarija; BoliviaFil: Alonso Vega, Cristina. Drugs For Neglected Diseases Initiative; SuizaFil: Pinazo, María-Jesús. Instituto de Salud Global de Barcelona; EspañaFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Almeida, Igor C. University of Texas at El Paso; Estados UnidosFil: Alves, Fabiana. Drugs For Neglected Diseases Initiative; SuizaFil: Strub-Wourgaft, Nathalie. Drugs For Neglected Diseases Initiative; SuizaFil: Ribeiro, Isabela. Drugs For Neglected Diseases Initiative; SuizaFil: Santina, Glaucia. Drugs For Neglected Diseases Initiative; SuizaFil: Blum, Bethania. Drugs For Neglected Diseases Initiative; SuizaFil: Correia, Erika. Drugs For Neglected Diseases Initiative; SuizaFil: García Bournissen, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Vaillant, Michel. Competence Center in Methodology and Statistics; LuxemburgoFil: Ramos Morales, Jimena. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Pinto Rocha, Jimy Jose. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Rojas Delgadillo, Gimena. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Magne Anzoleaga, Helmut Ramon. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Mendoza, Nilce. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Quechover, Roxana Challapa. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Caballero, Maria Yurly Escobar. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Lozano Beltran, Daniel Franz. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Zalabar, Albert Mendoza. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Rojas Panozo, Lizeth. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Palacios Lopez, Alejandro. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Torrico Terceros, Dunia. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Fernandez Galvez, Violeta Alejandra. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Cardozo, Letty. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Cuellar, Gabriela. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Vasco Arenas, Rudy Nelson. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Gonzales, Isabel. Platform for Comprehensive Care of Patients with Chagas Disease; BoliviaFil: Hoyos Delfin, Carlos Florencio. Universidad Juan Misael Saracho; BoliviaFil: Garcia, Lineth. Universidad Mayor de San Simón; BoliviaFil: Parrado, Rudy. Universidad Mayor de San Simón; BoliviaFil: de la Barra, Anabelle. Universidad Mayor de San Simón; BoliviaFil: Montaño, Nair. Universidad Mayor de San Simón; BoliviaFil: Villarroel, Sandro. Universidad Mayor de San Simón; BoliviaFil: Duffy, Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Bisio, Margarita María Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Ramirez Gomez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Duncanson, Fred. Eisai; JapónFil: Everson, Michael. Eisai; JapónFil: Daniels, Antonia. Eisai; JapónFil: Asada, Makoto. Eisai; JapónFil: Cox, Eugene. Quantitative Solutions; Países BajosFil: Wesche, David. Quantitative Solutions; Países BajosFil: Diderichsen, Paul Matthias. Quantitative Solutions; Países BajosFil: Marques, Alexandre F. Universidade Federal de Minas Gerais; BrasilFil: Izquierdo, Luis. ISGlobal; EspañaFil: Sender, Silvia Sanz. ISGlobal; EspañaFil: Reverter, Joan Carlos. Hospital Clinic Barcelona; EspañaFil: Morales, Manuel. Hospital Clinic Barcelona; EspañaFil: Jimenez, Wladimiro. Hospital Clinic Barcelona; Españ
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