Evaluation of Novel Chalcone-Thiosemicarbazones Derivatives as Potential Anti-Leishmania amazonensis Agents and Its HSA Binding Studies.

A series of seven chalcone-thiosemicarbazones (5a-5g) were synthesized and evaluated as potential new drugs (anti-leishmanial effect). Although four of the chalcone-thiosemicarbazones are already known, none of them or any compound in this class has been previously investigated for their effects on parasites of the Leishmania genus. The compounds were prepared in satisfactory yields (40-75%) and these compounds were evaluated against promastigotes, axenic amastigotes and intracellular amastigotes of L. amazonensis after 48 h of culture. The half maximal inhibitory concentration (IC50) values of the intracellular amastigotes were determined to be in the range of 3.40 to 5.95 µM for all compounds assayed. The selectivity index showed value of 15.05 for 5a, whereas pentamidine (reference drug) was more toxic in our model (SI = 2.32). Furthermore, to understand the preliminary relationship between the anti-leishmanial activity of the chalcone-thiosemicarbazones, their electronic (σ), steric (MR) and lipophilicity (π) properties were correlated, and the results indicated that moieties with electronic withdrawing effects increase the anti-leishmanial activity. The preliminary pharmacokinetic evaluation of one of the most active compound (5e) was studied via interaction to human serum albumin (HSA) using multiple spectroscopic techniques combined with molecular docking. The results of antiparasitic effects against L. amazonensis revealed the chalcone-thiosemicarbazone class to be novel prototypes for drug development against leishmaniasis.

In vitro and in vivo cytotoxic activity and human serum albumin interaction for a methoxy-styryl-thiosemicarbazone.

Thiosemicarbazone is a class of compounds with potential applications in medicine, presenting high capacity to inhibit the growth of cancer cells as well as low toxicity. Because of high interest in anticancer studies involving thiosemicarbazones as new chemotherapeutic agents, a synthetic thiosemicarbazone derivative, 4-N-(2'-methoxy-styryl)-thiosemicarbazone (MTSC) was evaluated in vivo against Ehrlich carcinoma in an animal model. In vivo results demonstrated that MTSC treatment induced the survival of mice and altered significantly the body weight of the surviving mice 12 days after tumor inoculation. Treatment with 30 mg/kg of MTSC exhibited effective cytotoxic activity with T/C values of 150.49% (1 dose) and 278% (2 doses). Its interaction with human serum albumin (HSA), which plays a crucial role in the biodistribution of a wide variety of ligands, was investigated by multiple spectroscopic techniques at 296 K, 303 K, and 310 K, as well as by theoretical calculations. The interaction between HSA and MTSC occurs via ground-state association in the subdomain IIA (Sudlow's site I). The binding is moderate (Ka ≈ 104 M-1), spontaneous, entropically, and enthalpically driven. Molecular docking results suggested hydrogen bonding and hydrophobic interactions as the main binding forces. Overall, the interaction HSA:MTSC could provide therapeutic benefits, improving its cytotoxic efficacy and tolerability.

Thiosemicarbazones as inhibitors of tyrosinase enzyme.

In the search for compounds which may inhibit the development of melanomas, a series of thiosemicarbazones has been investigated as possible inhibitors of the tyrosinase enzyme. The results showed that all the thiosemicarbazones tested exhibited significant inhibitory effects on the enzyme. Thiosemicarbazones Thio-1, Thio-2, Thio-3 and Thio-4 substituted with oxygenate moieties, were better inhibitors (IC50 0.42, 0.35, 0.36 and 0.44mM, respectively) than Thio-5, Thio-6, Thio-7 and Thio-8. For the better inhibitors, molecular docking results suggested that the oxygen present in the para position of the aromatic ring is essential for the tyrosinase inhibition, due its high ability for complexation with Cu2+ ions. Inside the active protein pocket, Thio-2 - the best studied inhibitor - is able to interact with the amino acid residues His-155, Gly-170 and Val-172 via hydrogen bonding and hydrophobic force. Thio-2, containing a substituent on the aromatic ring similar to the substrate l-DOPA, showed a competitive inhibition mechanism as viewed in a Lineweaver-Burk plot. The same results were observed in the UV-Vis curves.

P-glycoprotein efflux pump plays an important role in Trypanosoma cruzi drug resistance.

Drug resistance in protozoan parasites has been associated with the P-glycoprotein (Pgp), an energy-dependent efflux pump that transports substances across the membrane. Interestingly, the genes TcPGP1 and TcPGP2 have been described in Trypanosoma cruzi, although the function of these genes has not been fully elucidated. The main goal of this work was to investigate Pgp efflux pump activity and expression in T. cruzi lines submitted to in vitro induced resistance to the compounds 4-N-(2-methoxy styryl)-thiosemicarbazone (2-Meotio) and benznidazole (Bz) and to verify the stability of the resistant phenotypes during the parasite life cycle. We observed that the EC50 values for the treatment of epimastigotes with 2-Meotio or Bz were increased at least 4.7-fold in resistant lines, and this phenotype was maintained in metacyclic trypomastigotes, cell-derived trypomastigotes, and intracellular amastigotes. However, in epimastigotes, 2-Meotio resistance is reversible, but Bz resistance is irreversible. When compared with the parental line, the resistant lines exhibited higher Pgp efflux activity, reversion of the resistant phenotypes in the presence of Pgp inhibitors, cross-resistance with Pgp modulators, higher basal Pgp ATPase activity, and overexpression of the genes TcPGP1 and TcPGP2. In conclusion, the resistance induced in T. cruzi by the compounds 2-Meotio and Bz is maintained during the entire parasite life cycle. Furthermore, our data suggest the participation of the Pgp efflux pump in T. cruzi drug resistance.

[Risk model to assess livestock rabies exposure in the state of São Paulo, Brazil]. / Modelo de risco para circulação do vírus da raiva em herbívoros no estado de São Paulo, Brasil.

OBJECTIVE: To propose a qualitative risk assessment model for the study of livestock exposure to rabies virus from the vampire bat Desmodus rotundus (antigenic variant 3) in the Paraíba do Sul river valley, state of São Paulo, Brazil. METHODS: Based on scenario trees generated considering rabies exposure and its spread, we estimated the probability of rabies cases in large livestock and its association with the geographic location of livestock farms. RESULTS: Assessment of the historical series of rabies focal points in the first semester of 2006, which was used to validate the risk assessment model, revealed that 81.8% of the focal points were adequately foreseen by the model and could have been prevented with strategic vaccination in high-risk areas. CONCLUSIONS: The adoption of control measures specifically targeting high-risk areas might entail a substantial decrease in the number of rabies focal points, at a low cost and with optimal movement of field teams.

Modelo de risco para circulação do vírus da raiva em herbívoros no estado de São Paulo, Brasil / Risk model to assess livestock rabies exposure in the state of São Paulo, Brazil

OBJETIVO: Propor uma metodologia qualitativa de avaliação do risco de circulação do vírus da raiva mantido por morcegos hematófagos (variante 3) em populações de herbívoros de interesse econômico do Vale do Rio Paraíba do Sul, Estado de São Paulo, Brasil. MÉTODOS: A partir de árvores de cenário que levam em conta a exposição e a difusão da raiva, estimou-se a probabilidade de ocorrência da raiva em herbívoros de grande porte e a sua associação à localização geográfica das propriedades. RESULTADOS: Com base na série histórica de focos do primeiro semestre de 2006, utilizada para validar o modelo de risco, observou-se que 81,8 por cento dos focos de raiva foram adequadamente previstos pelo modelo e poderiam ter sido prevenidos caso fosse adotada vacinação estratégica em áreas de risco elevado para a circulação do vírus. CONCLUSÕES: Caso fossem desencadeadas medidas de controle direcionadas somente para áreas de risco elevado, a diminuição dos focos poderia ser substancial, a um custo reduzido e com deslocamento otimizado das equipes de campo.

OBJECTIVE: To propose a qualitative risk assessment model for the study of livestock exposure to rabies virus from the vampire bat Desmodus rotundus (antigenic variant 3) in the Paraíba do Sul river valley, state of São Paulo, Brazil. METHODS: Based on scenario trees generated considering rabies exposure and its spread, we estimated the probability of rabies cases in large livestock and its association with the geographic location of livestock farms. RESULTS: Assessment of the historical series of rabies focal points in the first semester of 2006, which was used to validate the risk assessment model, revealed that 81.8 percent of the focal points were adequately foreseen by the model and could have been prevented with strategic vaccination in high-risk areas. CONCLUSIONS: The adoption of control measures specifically targeting high-risk areas might entail a substantial decrease in the number of rabies focal points, at a low cost and with optimal movement of field teams.

Correlation between the Friedman classification and the Apnea-Hypopnea Index in a population with OSAHS.

UNLABELLED: OSAHS is an important disease in current medical settings because of its association with chronic cardiovascular diseases and socioeconomic impacts. AIMS: to establish the correlation between the Friedman Classification and the OSAHS severity through the Apnea-Hypopnea Index) in patients with OSAHS for assessment and surgery purposes. MATERIALS AND METHODS: Cross-sectional study. We evaluated and classified 143 patients, using the Epworth's and Friedman's scale and OSAHS severity according to the AHI. RESULTS: 112 patients were submitted to polysomnography. We compared the Friedman Score and the IAH. The variables were associated with p<0.05. We found that patients with light OSAHS, tended to have a lower Friedman classification (better surgical result). By the same token, patients with moderate to severe OSAHS had a greater prevalence of Friedman's score of III and IV; p< 0.05 (lower success rates from uvulopalatopharyngoplasty). CONCLUSION: We conclude that the Friedman's classification correlates with OSAHS severity - the higher the Friedman's score, the more severe is the OSAHS.

Nasal obstruction and high Mallampati score as risk factors for Obstructive Sleep Apnea.

UNLABELLED: Respiratory sleep disorders are strongly associated with upper airway patency. Nasal obstruction is associated with higher incidences of sleep apnea, primarily by increasing the negative pressure on the airway during inspiration. AIMS: To evaluate the influence of nasal obstruction in the worsening of sleep apnea in patients with OSA and a high score on the modified classification of Mallampati. MATERIALS AND METHODS: We evaluated and classified 206 patients complaining of snoring, and with a past suggestive of OSA through the Modified Mallampati score, Friedman, nasal obstruction and the severity of OSA by AHI. RESULTS: 168 patients who underwent polysomnography were included. Cross-plotting was made comparing the modified Mallampati score, nasal obstruction and AIH. The odds ratio between high Mallampati score and AHI was OR = 5.053, 95% CI = 1.458 to 7.517 (p = 0.0071). High Mallampati score associated with nasal obstruction was correlated with OSAS (p = 0.0227). However the influence of nasal obstruction on the relationship of high Mallampati score and OSA was not significant: OR = 2.850, 95% CI = 0.992 to 8.189. CONCLUSION: The combination of high Mallampati score and nasal obstruction represents a greater risk factor for worsening of OSA.

Correlação entre a classificação de Friedman e Índice de Apneia-Hipopneia em portadores de Síndrome da Apneia e Hipopneia Obstrutiva do Sono / Correlation between the Friedman classification and the Apnea-Hypopnea Index in a population with OSAHS

ASAHOS é uma doença importante no cenário médico atual pela sua correlação com doenças cardiovasculares crônicas e suas consequências socioeconômicas. OBJETIVOS: Determinar a correlação entre a classificação de Friedman com a gravidade da doença pelo Índice de Apneia e Hipopneia em pacientes com SAHOS, para a avaliação e indicação cirúrgica. MATERIAIS E MÉTODOS: Estudo transversal. Foram avaliados e classificados 143 pacientes, na escala de Epworth, Friedman e quanto à gravidade da SAHOS pelo IAH. RESULTADOS: 112 pacientes se submeteram ao estudo de polissonografia no laboratório de sono. Uma crostabulação foi feita entre a Classificação de Friedman e o IAH. As variáveis se relacionam com p<0,05. Encontramos uma relação em que os pacientes com SAHOS leve tendem a ter uma menor classificação de Friedman (melhores resultados cirúrgicos). Da mesma forma os pacientes classificados como SAHOS moderada a grave possuem maior prevalência da classificação de Friedman III e IV (menor sucesso com uvulopalatofaringoplastia). p<0.05. CONCLUSÃO: Concluímos que a classificação de Friedman se correlaciona com a gravidade da SAHOS. Quanto maior a classificação de Friedman, maior tende a ser a gravidade da apneia nesse estudo.

OSAHS is an important disease in current medical settings because of its association with chronic cardiovascular diseases and socioeconomic impacts. AIMS: to establish the correlation between the Friedman Classification and the OSAHS severity through the Apnea-Hypopnea Index) in patients with OSAHS for assessment and surgery purposes. MATERIALS AND METHODS: Cross-sectional study. We evaluated and classified 143 patients, using the Epworth's and Friedman's scale and OSAHS severity according to the AHI. RESULTS: 112 patients were submitted to polysomnography. We compared the Friedman Score and the IAH. The variables were associated with p<0.05. We found that patients with light OSAHS, tended to have a lower Friedman classification (better surgical result). By the same token, patients with moderate to severe OSAHS had a greater prevalence of Friedman's score of III and IV; p< 0.05 (lower success rates from uvulopalatopharyngoplasty). CONCLUSION: We conclude that the Friedman's classification correlates with OSAHS severity - the higher the Friedman's score, the more severe is the OSAHS.

Obstrução nasal e alto escore de Mallampati como fatores de risco associados para Apneia Obstrutiva do Sono / Nasal obstruction and high Mallampati score as risk factors for Obstructive Sleep Apnea

Os distúrbios respiratórios do sono estão associados à perviedade das vias aéreas superiores. Obstrução nasal é associada com o aumento de eventos de apneia do sono, principalmente pelo aumento da pressão negativa imposta às vias aéreas durante a inspiração. OBJETIVO: Avaliar a influência da obstrução nasal associada à classificação modificada de Mallampati na gravidade da SAOS. MATERIAIS E MÉTODOS: Foram avaliados e classificados 206 pacientes com queixa de roncos e história sugestiva de SAOS através do Escore Modificado de Mallampati, Friedman, obstrução nasal e quanto à gravidade da SAOS pelo IAH. RESULTADOS: Foram incluídos 168 pacientes que se submeteram ao estudo de polissonografia no laboratório de sono. Uma crostabulação foi feita entre o escore modificado de Mallampati, obstrução nasal e o IAH. O Oddis Ratio entre alto escore de Mallampati e IAH foi OR=5,053, IC 95 por cento=1,458 - 7,517(p = 0,0071). Alto Mallampati associado com obstrução nasal se correlacionam com SAOS (p=0,0227). Entretanto, a influência da obstrução nasal sobre a relação do alto escore de Mallampati e SAOS não foi significativa OR = 2,850, IC 95 por cento=0,992 - 8,189. CONCLUSÃO: A associação de alto escore de Mallampati e obstrução nasal é fator de risco para agravamento da SAOS.

Respiratory sleep disorders are strongly associated with upper airway patency. Nasal obstruction is associated with higher incidences of sleep apnea, primarily by increasing the negative pressure on the airway during inspiration. AIMS: To evaluate the influence of nasal obstruction in the worsening of sleep apnea in patients with OSA and a high score on the modified classification of Mallampati. MATERIALS AND METHODS: We evaluated and classified 206 patients complaining of snoring, and with a past suggestive of OSA through the Modified Mallampati score, Friedman, nasal obstruction and the severity of OSA by AHI. RESULTS: 168 patients who underwent polysomnography were included. Cross-plotting was made comparing the modified Mallampati score, nasal obstruction and AIH. The odds ratio between high Mallampati score and AHI was OR = 5.053, 95 percent CI = 1.458 to 7.517 (p = 0.0071). High Mallampati score associated with nasal obstruction was correlated with OSAS (p = 0.0227). However the influence of nasal obstruction on the relationship of high Mallampati score and OSA was not significant: OR = 2.850, 95 percent CI = 0.992 to 8.189. CONCLUSION: The combination of high Mallampati score and nasal obstruction represents a greater risk factor for worsening of OSA.

Media ion composition controls regulatory and virulence response of Salmonella in spaceflight.

The spaceflight environment is relevant to conditions encountered by pathogens during the course of infection and induces novel changes in microbial pathogenesis not observed using conventional methods. It is unclear how microbial cells sense spaceflight-associated changes to their growth environment and orchestrate corresponding changes in molecular and physiological phenotypes relevant to the infection process. Here we report that spaceflight-induced increases in Salmonella virulence are regulated by media ion composition, and that phosphate ion is sufficient to alter related pathogenesis responses in a spaceflight analogue model. Using whole genome microarray and proteomic analyses from two independent Space Shuttle missions, we identified evolutionarily conserved molecular pathways in Salmonella that respond to spaceflight under all media compositions tested. Identification of conserved regulatory paradigms opens new avenues to control microbial responses during the infection process and holds promise to provide an improved understanding of human health and disease on Earth.

Novel Sfp1 transcriptional regulation of Saccharomyces cerevisiae gene expression changes during spaceflight.

This study identifies transcriptional regulation of stress response element (STRE) genes in space in the model eukaryotic organism, Saccharomyces cerevisiae. To determine transcription-factor dependence, gene expression changes in space were examined in strains bearing green fluorescent protein-tagged (GFP-tagged) reporters for YIL052C (Sfp1 dependent with stress), YST-2 (Sfp1/Rap1 dependent with stress), or SSA4 (Msn4 dependent with stress), along with strains of SSA4-GFP and YIL052C-GFP with individual deletions of the Msn4 or Sfp1. When compared to parallel ground controls, spaceflight induces significant gene expression changes in SSA4 (35% decrease) and YIL052C (45% decrease), while expression of YST-2 (0.08% decrease) did not change. In space, deletion of Sfp1 reversed the SSA4 gene expression effect (0.00% change), but Msn4 deletion yielded a similar decrease in SSA4 expression (34% change), which indicates that SSA4 gene expression is dependent on the Sfp1 transcription factor in space, unlike other stresses. For YIL052C, deletion of Sfp1 reversed the effect (0.01% change), and the Msn4 deletion maintained the decrease in expression (30% change), which indicates that expression of YIL052C is also dependent on Sfp1 in space. Spaceflight has selective and specific effects on SSA4 and YIL052C gene expression, indicated by novel dependence on Sfp1.