Atividade de catecolase de uma série de complexos binucleares de manganês(II,III)

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em QuímicaNeste trabalho foram sintetizados e caracterizados quatro novos complexos de MnIIMnIII utilizando um novo ligante, o H2bpbpmp-Br e os ligantes já descritos H2Ldtb, H2bpbpmp-CH3 e H2bpbpmp-NO2. A partir destes ligantes foram obtidos os correspondentes complexos binucleares de manganês de valência mista. Todos os complexos foram caracterizados por espectroscopia eletrônica, espectroscopia no infravermelho e eletroquímica. Na análise do comportamento redox dos complexos em soluções de CH3CN foi observada uma correlação linear entre os potenciais de meia-onda, para o metal trivalente coordenado ao fenolato terminal com os parâmetros de Hammet para os grupos substituintes. Deve se enfatizar que este é o primeiro trabalho na literatura em que se utiliza complexos binucleares de valência mista MnIIMnIII na atividade de catecolase, reação de oxidação do 3,5-di-tercbutilcatecol, e que todos os complexos apresentaram excelente atividade na reação de oxidação e os produtos observados para a reação foram a 3,5-di-terc-butil-o-benzoquinona e peróxido de hidrogênio. Assim, os compostos podem ser considerados bons modelos funcionais para a catecol oxidase, enzima binuclear de cobre(II) que catalisa a oxidação de catecóis a o-quinonas.

Síntese e caracterização de um novo complexo homodinuclear de manganês como modelo para o sitio ativo das catalases de manganês

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Físicas e Matemáticas. Curso de Química.As catalases de manganês de Thermus thermophilus, Lactobacillus plantarum e Thermoleophilum album são importantes enzimas antioxidantes que protegem as células contra os efeitos causados pelo peróxido de hidrogênio. Estas enzimas catalisam o desproporcionamento do peróxido de hidrogênio em água e oxigênio molecular. Neste sentido, apresenta-se no presente trabalho a síntese, caracterização e a atividade de catalase de um complexo binuclear de manganês [MnIIMnIII(BPBPMP-NO2)(m-OAc)2]ClO4. Novos complexos de manganês tem merecido especial atenção com o objetivo de se obter análogos sintéticos de baixa massa molar que mimetizem as propriedades catalíticas dessas enzimas. O ligante utilizado H2BPBPMP-NO2 foi sintetizado de maneira similar ao ligante H2BPBPMP publicado por Neves e colaboradores e caracterizado por RMN 1H e infravermelho, sendo o objetivo da substituição por um grupo retirador de elétrons (NO2) na posição para ao fenol é de se observar o efeito sobre o potencial redox dos centros metálicos, bem como das propriedades espectroscópicas e reatividade frente ao H2O2. Assim, pela analogia ao complexo [MnII MnIII(BPBPMP)(m-OAc)2]BF4, foi feito um estudo da reatividade do mesmo e o complexo demonstra cinética de saturação com H2O2 (0,3 – 3 mmol), que tratada pelo método das velocidades iniciais obtêm-se os seguintes parâmetros cinéticos: Vmax = 1,79 x 10-3 mmol.s-1; KM = 113 mmol.L-1 e kcat = 1,59 s-1, demonstrando que o complexo [MnIIMnIII(BPBPMP-NO2)(m-OAc)2]ClO4 pode ser considerado como modelo para as catalases de manganês

Avaliação das Áreas de Disposição Final dos Resíduos Sólidos Urbanos de Itacoatiara, Amazonas

The high generation of Urban Solid Waste (USW) is directly related to the consumption of resources in cities, causing environmental pressure and negative impacts on the environment. The objective of this study was to analyze the final disposal areas of USW in the municipality of Itacoatiara - AM, according to the Index of Waste Landfill Quality (IWLQ), determined by the Environmental Company of the State of São Paulo. The IWLQ was applied to the final disposal areas of USW in the urban and rural areas of the municipality (Vila de Novo Remanso, Vila de Lindóia, and Vila de Engenho) in August 2022, assigning weights to structural, operational, and locational aspects. The results showed that the final disposal areas in the urban zone (IWLQ= 2.0), Vila de Novo Remanso (IWLQ =1.1), Vila de Engenho (IWLQ= 1.4), and Vila de Lindóia (IWLQ= 1.3) have inadequate operating conditions, due to various irregular operational, structural, and locational aspects that indicate the unsustainability of these areas. These results indicate the need for corrective measures to minimize the negative impacts on the environment.A elevada geração de Resíduos Sólidos Urbanos (RSU) está diretamente relacionada com o consumo de recursos das cidades, causando pressão ambiental e impactos negativos sobre o meio ambiente. O objetivo deste estudo foi analisar as áreas de disposição final dos RSU do município de Itacoatiara – AM, conforme o Índice de Qualidade de Aterros de Resíduos (IQR), determinado pela Companhia Ambiental do Estado de São Paulo. Foi realizado a aplicação do IQR nas áreas de disposição final dos RSU da zona urbana e rural do município (Vila de Novo Remanso, Vila de Lindóia e Vila de Engenho) em agosto de 2022, atribuindo pesos aos aspectos estruturais, operacionais e locacionais. Os resultados mostraram que as áreas de disposição final da zona urbana (IQR= 2,0), Vila de Novo Remanso (IQR= 1,1), Vila de Engenho (IQR= 1,4) e Vila de Lindóia (IQR= 1,3) possuem condições inadequadas de funcionamento, em virtude dos vários aspectos operacionais, estruturais e locacionais irregulares que atestaram a insustentabilidade das áreas. Estes resultados apontam para a necessidade de correções, que minimizem os impactos negativos sobre o meio ambiente

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Oxindolimine-metal complexes immobilized in beidellite clays

Estudos sobre a inserção de complexos oxindolimínicos de cobre(II) ou zinco(II) em argilas sintéticas beidelitas foram desenvolvidos visando obter carregadores inorgânicos capazes de promover a liberação modificada de metalofármacos. Investigações anteriores mostraram que os complexos estudados são promissores agentes antitumorais. São capazes de se ligar ao DNA, nas alças menor ou maior dependendo do ligante, causando danos oxidativos através da formação de espécies reativas de oxigênio (EROs), especialmente radicais hidroxil, no caso de complexos de cobre, que apresentam atividade redox. Também interagem com mitocôndrias levando a uma diminuição do potencial de membrana e atuando como agentes desacopladores. Constituem assim compostos indutores de apoptose ou morte celular programada. Adicionalmente inibem proteínas envolvidas no ciclo celular, como topoisomerase I humana e quinases dependentes de ciclina (CDK1 e CDK2). As beidelitas foram sintetizadas e caracterizadas por métodos já descritos na literatura. Posteriormente, em presença dos complexos, formaram materiais híbridos do tipo beidellita/[complexo]. A caracterização das argilas e dos materiais híbridos obtidos foi realizada usando diferentes técnicas: espectroscopias UV/Vis, IV e EPR, análise termogravimétrica, difratometria de raios X. Na caracterização dos complexos utilizou-se ainda espectrometria de massas (ESI-MS). Os materiais híbridos preparados mostraram-se estáveis e capazes de inviabilizar células tumorais (HeLa), no caso dos materiais híbridos com compostos de cobre(II), com IC50 na faixa de 0,11 a 0,41 mg/mL. Ao contrário, os compostos análogos de zinco(II) e as argilas puras mostraram-se não-tóxicas frente às mesmas células. Os resultados obtidos indicam uma promissora possibilidade de uso das beidellitas como carregadores destes complexos metálicos.Studies on the insertion of oxindolimine complexes of copper(II) or zinc(II) in synthetic beidellites clays have been developed to obtain an inorganic support capable of promoting the modified-release of metallopharmaceuticals. Previous investigations have shown that the studied complexes are promising antitumor agents. They are able to bind to DNA, in the minor or major groves, causing oxidative damage via formation of reactive oxygen species (ROS), especially hydroxyl radicals, in the case of copper complexes, which have redox properties. They also interact with mitochondria leading to a decrease of membrane potential and acting as decoupling agent. Thus, these compounds can induce apoptosis or programmed cell death. Additionally, they inhibit proteins involved in the cell cycle, such as human topoisomerase I and cyclin dependent kinases (CDK1 and CDK2). The beidellites were synthesized and characterized by methods described in the literature. Additionally, in the presence of these complexes were obtained hybrid materials type beidellita/[complex]. The characterization of clays and the obtained hybrid materials were performed using different techniques: spectroscopy UV/Vis, IR and EPR, thermogravimetric analysis, X-ray powder diffraction. In the characterization of the complexes mass spectrometry (ESI-MS) was also used. The prepared hybrid materials were stable and able to derail tumor cells (HeLa) in the case of hybrid materials with copper(II) compounds, with IC50 in the range from 0.11 to 0.41 mg/mL. Unlikely, the analogous compounds of zinc(II) and pure clays have proved to be non-toxic facing the same cells. These results indicate a promising possibility of using the beidellites as carriers of these antitumor metal complexe

Antiparasitic Activity of Oxindolimine–Metal Complexes against Chagas Disease

Some copper(II) and zinc(II) complexes with oxindolimine ligands were tested regarding their trypanocidal properties. These complexes have already shown good biological activity in the inhibition of tumor cell proliferation, having DNA and mitochondria as main targets, through an oxidative mechanism, and inducing apoptosis. Herein, we demonstrate that they also have significant activity against the infective trypomastigote forms and the intracellular amastigote forms of T. cruzi, modulated by the metal ion as well as by the oxindolimine ligand. Selective indexes (LC50/IC50) determined for both zinc(II) and copper(II) complexes, are higher after 24 or 48 h incubation with trypomastigotes, in comparison to traditional drugs used in clinics, such as benznidazole, and other metal-based compounds previously reported in the literature. Additionally, tests against amastigotes indicated infection index <10% (% of infected macrophages/average number of amastigotes per macrophage), after 24 or 48 h in the presence of zinc(II) (60–80 µM) or analogous copper(II) complexes (10–25 µM). The copper complexes exhibit further oxidative properties, being able to damage DNA, proteins and carbohydrates, in the presence of hydrogen peroxide, with the generation of hydroxyl radicals. This redox reactivity could explain its better performance towards the parasites in relation to the zinc analogs. However, both copper and zinc complexes display good selective indexes, indicating that the influence of the ligand is also crucial, and is probably related to the inhibition of some crucial proteins

Fratura proximal de tíbia após cirurgia extracapsular para correção de ruptura de ligamento cruzado cranial em cão Tibial fracture caused by complications after an extracapsular suture for the repair of cranial cruciate ligament rupture in a dog

Ruptura de ligamento cruzado cranial (RLCCr) é a afecção ortopédica mais frequente no joelho de cães e a sutura fabelo-tibial é frequentemente utilizada na sua correção. Essa técnica pode estar associada com complicações incisionais, lesão tardia de menisco, edema associado ao material de sutura e infecção. O objetivo desta nota foi relatar a ocorrência de fratura proximal de tíbia em um cão, causada por complicação em sutura fabelo-tibial para correção de RLCCr. Um canino atendido em outro serviço foi submetido à osteossíntese com placa 2,0mm para correção de complicação em técnica extra-capsular, na qual houve fratura da tíbia na região do orifício criado para confecção da sutura fabelo-tibial. Houve falha dos implantes e a placa foi removida. A fratura foi estabilizada com fixador esquelético externo circular, sendo constatada, após 120 dias, consolidação.<br>Cranial cruciate ligament rupture (CCLR) is one of the most common orthopedic diseases in dogs and extracapsular suture with nylon is often used for its correction. This technique may be associated with incisional complications, post-surgical meniscus injury, swelling associated with suture material and infection. The objective of this study is to report a tibial fracture in a dog, caused by complications after an extracapsular suture for the repair of CCLR. An adult dog, which suffered a tibial fracture after an extracapsular fixation for a CCLR, underwent surgery for the fixation of the fracture with a 2.0mm plate, by a referring veterinarian, but the implant failed. The plate was removed and the fracture was stabilized with a circular fixator. Bone consolidation was observed after 120 days

Canine visceral leishmaniasis follow-up : a new anti-IgG serological test more sensitive than ITS-1 conventional PCR.

Visceral leishmaniasis (VL) is a neglected tropical disease with dogs serving as reservoirs for one of its etiological agents, Leishmania infantum. In Brazil, VL control involves culling of seropositive dogs, among other actions. However, the most employed serological tests lack accuracy, and are not able to detect canine visceral leishmaniasis (CVL) during the early stages of infection. Early detection of CVL is highly desirable in order to shorten the contact time between the infected reservoirs and the vectors. In this study, we investigated the ability of two multiepitope proteins, PQ10 and PQ20, to detect CVL at earlier stages than currently employed methods, including ITS-1 conventional PCR. Using serum samples from naturally infected dogs, we observed that ELISAPQ10 and ELISA-PQ20 were able to detect Leishmania infection at earlier time points as compared with kDNA PCR-RFLP in anti-IgG and anti-IgM assays. Using sera from experimentally infected dogs, we monitored seroconversion using multiepitope proteins, ELISA-crude antigen, as well as ITS-1 conventional and real-time PCR. While seroconversion was detected by ELISA-crude antigen in 16.6% of the dogs, multiepitope proteins were able to detect seroconversion in more than 80% of them. Moreover, the ability of ELISA-PQ10 and ELISA-PQ20 to detect Leishmania infection at earlier time points as compared with conventional PCR was also confirmed in experimental infection dogs? sera. Immunofluorescence to Babesia canis and Ehrlichia canis did not show crossreactions with ELISA-PQ10/PQ20 positive samples. Results of real-time PCR and ELISA with multiepitope proteins were very similar, with concordances between 80 and 100%. Furthermore, our findings indicated that PQ10 and PQ20 immunoassays can be related to parasite load. ELISA-PQ10 and ELISA-PQ20 are more sensitive diagnostic tools for early CVL detection as compared with other methods They could potentially be used in screening tests due to easy execution and low costs facilities