Objective:To evaluate parasitemia by qPCR in patients undergoing etiological treatment and followed in a Brazilian reference center.Methods:Parasite load was quantified by qPCR in 32 participants with chronic Chagas d...Objective:To evaluate parasitemia by qPCR in patients undergoing etiological treatment and followed in a Brazilian reference center.Methods:Parasite load was quantified by qPCR in 32 participants with chronic Chagas disease who were treated with benznidazole.Serological analyses were performed before and after the treatment and parasite loads were compared prior and 12/18 months post the treatment.Results:Thirty-two participants were recruited and treated with benznidazole,and 20 were followed-up.Adverse events(AE)were observed in 22 out of 29 participants that had safety data(76%),and dermatological alterations were the most frequently observed AE.Of the 20 participants analyzed,13 and 7 completed 12 and 18 months follow-up after the treatment,respectively.12 Months after the final treatment,Trypanosoma cruzi was detectable in 3 patients by qPCR;18 months after the final treatment,Trypanosoma cruzi was detectable per qPCR in 4 of the 7 participants.Thus,between 12 and 18 months,7 participants of the 20 initial follow-up cases showed positive qPCR,indicating treatment failures.Conclusions:qPCR can be used as an alternative method for evaluating the effectiveness of the etiological treatment of CD,and can be applied to analyze early therapeutic failures.The study showed that benznidazole therapy had limited effectiveness in treating chronic CD patients,thus emphasizing the importance of conducting continued research for developing more effective therapies and diagnosis for CD.展开更多
Herein,we studied the interaction of bovine pancreatic ribonuclease(RNase A)with[V^(Ⅳ)O(8-HQ)_(2)]–a promising antitrypanosomal,antituberculosis,and antitumor vanadium complex(VC)formed by 8-hydroxyquinolinato(8-HQ)...Herein,we studied the interaction of bovine pancreatic ribonuclease(RNase A)with[V^(Ⅳ)O(8-HQ)_(2)]–a promising antitrypanosomal,antituberculosis,and antitumor vanadium complex(VC)formed by 8-hydroxyquinolinato(8-HQ),reaching IC_(50) values lower than cisplatin in HCT116 and A2780 cancer lines(0.99 and 0.96μM vs.15.0 and 3.4μM)and the minimum inhibitory concentration(MIC)of 3.7μM against strains of Mycobacterium tuberculosis.The system was investigated by spectroscopic(UV-vis absorption spectroscopy,circular dichroism,and electron paramagnetic resonance),computational(docking and DFT calculations),and X-ray crystallographic multi-technique approach.Crystallographic results at pH 5.1 demonstrate that upon interaction with the protein,one of the 8-HQ ligands is replaced by a water molecule and by Glu111 side-chain,resulting in the inhibition of the RNase A activity.EPR data confirm the formation of this adduct,with V^(Ⅳ) coordinated by 8-HQ and by the couples(Glu-COO^(−);H_(2)O)at pH 5.1,(His-N;H_(2)O)at pH 7.4,and(His-N;OH^(−))or(Ser/Thr-O^(−),H_(2)O)at pH 8.4.Computational data unveil the reasons behind the ligand exchange,not observed for similar complexes like[V^(Ⅳ)O(picolinato)_(2)]and not predicted by thermodynamic considerations.Overall,our results show that the VC–protein binding is defined not only by the thermodynamic stability of VC but also by other factors,such as the structure and steric requirements of the metal ligands,with important implications in the drug delivery strategies.展开更多
基金Fundação de AmparoàPesquisa do Estado de São Paulo-FAPESP.Process number 2016/08737-0TBSP received a Ph.D.scholarship from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES,Finance code 001).
文摘Objective:To evaluate parasitemia by qPCR in patients undergoing etiological treatment and followed in a Brazilian reference center.Methods:Parasite load was quantified by qPCR in 32 participants with chronic Chagas disease who were treated with benznidazole.Serological analyses were performed before and after the treatment and parasite loads were compared prior and 12/18 months post the treatment.Results:Thirty-two participants were recruited and treated with benznidazole,and 20 were followed-up.Adverse events(AE)were observed in 22 out of 29 participants that had safety data(76%),and dermatological alterations were the most frequently observed AE.Of the 20 participants analyzed,13 and 7 completed 12 and 18 months follow-up after the treatment,respectively.12 Months after the final treatment,Trypanosoma cruzi was detectable in 3 patients by qPCR;18 months after the final treatment,Trypanosoma cruzi was detectable per qPCR in 4 of the 7 participants.Thus,between 12 and 18 months,7 participants of the 20 initial follow-up cases showed positive qPCR,indicating treatment failures.Conclusions:qPCR can be used as an alternative method for evaluating the effectiveness of the etiological treatment of CD,and can be applied to analyze early therapeutic failures.The study showed that benznidazole therapy had limited effectiveness in treating chronic CD patients,thus emphasizing the importance of conducting continued research for developing more effective therapies and diagnosis for CD.
基金supported by Fondazione di Sardegna(grant FdSGarribba2017)Spanish MINECO’Juan de la Cierva program,FJC2019-039135-I.
文摘Herein,we studied the interaction of bovine pancreatic ribonuclease(RNase A)with[V^(Ⅳ)O(8-HQ)_(2)]–a promising antitrypanosomal,antituberculosis,and antitumor vanadium complex(VC)formed by 8-hydroxyquinolinato(8-HQ),reaching IC_(50) values lower than cisplatin in HCT116 and A2780 cancer lines(0.99 and 0.96μM vs.15.0 and 3.4μM)and the minimum inhibitory concentration(MIC)of 3.7μM against strains of Mycobacterium tuberculosis.The system was investigated by spectroscopic(UV-vis absorption spectroscopy,circular dichroism,and electron paramagnetic resonance),computational(docking and DFT calculations),and X-ray crystallographic multi-technique approach.Crystallographic results at pH 5.1 demonstrate that upon interaction with the protein,one of the 8-HQ ligands is replaced by a water molecule and by Glu111 side-chain,resulting in the inhibition of the RNase A activity.EPR data confirm the formation of this adduct,with V^(Ⅳ) coordinated by 8-HQ and by the couples(Glu-COO^(−);H_(2)O)at pH 5.1,(His-N;H_(2)O)at pH 7.4,and(His-N;OH^(−))or(Ser/Thr-O^(−),H_(2)O)at pH 8.4.Computational data unveil the reasons behind the ligand exchange,not observed for similar complexes like[V^(Ⅳ)O(picolinato)_(2)]and not predicted by thermodynamic considerations.Overall,our results show that the VC–protein binding is defined not only by the thermodynamic stability of VC but also by other factors,such as the structure and steric requirements of the metal ligands,with important implications in the drug delivery strategies.
