RESUMEN
The disease coronavirus COVID-19 has been the cause of millions of deaths worldwide. Among the proteins of SARS-CoV-2, non-structural protein 12 (NSP12) plays a key role during COVID infection and is part of the RNA-dependent RNA polymerase complex. The monitoring of NSP12 polymorphisms is extremely important for the design of new antiviral drugs and monitoring of viral evolution. This study analyzed the NSP12 mutations detected in circulating SARS-CoV-2 during the years 2020 to 2022 in the population of the city of Manaus, Amazonas, Brazil. The most frequent mutations found were P323L and G671S. Reports in the literature indicate that these mutations are related to transmissibility efficiency, which may have contributed to the extremely high numbers of cases in this location. In addition, two mutations described here (E796D and R914K) are close and have RMSD that is similar to the mutations M794V and N911K, which have been described in the literature as influential on the performance of the NSP12 enzyme. These data demonstrate the need to monitor the emergence of new mutations in NSP12 in order to better understand their consequences for the treatments currently used and in the design of new drugs.
Asunto(s)
COVID-19 , ARN Polimerasa Dependiente de ARN de Coronavirus , SARS-CoV-2 , Humanos , Brasil , Simulación por Computador , COVID-19/virología , COVID-19/transmisión , Mutación/genética , SARS-CoV-2/genética , Proteínas no Estructurales Virales/genética , ARN Polimerasa Dependiente de ARN de Coronavirus/genética , ARN Polimerasa Dependiente de ARN de Coronavirus/metabolismoRESUMEN
The rapid spread of the SARS-CoV-2 Variant of Concern (VOC) Gamma in Amazonas during early 2021 fueled a second large COVID-19 epidemic wave and raised concern about the potential role of reinfections. Very few cases of reinfection associated with the VOC Gamma have been reported to date, and their potential impact on clinical, immunological, and virological parameters remains largely unexplored. Here we describe 25 cases of SARS-CoV-2 reinfection in Brazil. SARS-CoV-2 genomic analysis confirmed that individuals were primo-infected with distinct viral lineages between March and December 2020 (B.1.1, B.1.1.28, B.1.1.33, B.1.195, and P.2) and reinfected with the VOC Gamma between 3 to 12 months after primo-infection. We found a similar mean cycle threshold (Ct) value and limited intra-host viral diversity in both primo-infection and reinfection samples. Sera of 14 patients tested 10-75 days after reinfection displayed detectable neutralizing antibodies (NAb) titers against SARS-CoV-2 variants that circulated before (B.1.*), during (Gamma), and after (Delta and Omicron) the second epidemic wave in Brazil. All individuals had milder or no symptoms after reinfection, and none required hospitalization. These findings demonstrate that individuals reinfected with the VOC Gamma may display relatively high RNA viral loads at the upper respiratory tract after reinfection, thus contributing to onward viral transmissions. Despite this, our study points to a low overall risk of severe Gamma reinfections, supporting that the abrupt increase in hospital admissions and deaths observed in Amazonas and other Brazilian states during the Gamma wave was mostly driven by primary infections. Our findings also indicate that most individuals analyzed developed a high anti-SARS-CoV-2 NAb response after reinfection that may provide some protection against reinfection or disease by different SARS-CoV-2 variants.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Brasil/epidemiología , COVID-19/epidemiología , Diversidad de Anticuerpos , Rayos gamma , Reinfección , Gravedad del PacienteRESUMEN
Depression in older adults with multiple medical comorbidities can contribute to clinical deterioration, and increased mortality. Electroconvulsive therapy (ECT) is the first-line treatment for these patients. This study aimed to evaluate the effectiveness and safety of subcutaneous (SC) ketamine as an alternative to ECT. We reviewed the medical records of all consecutive older inpatients with severe depression and multiple medical comorbidities who were referred for ECT but treated with SC ketamine over 1 year in our institution. Demographic data, DSM-5 diagnosis, MÅDRS score, and CGI score were analyzed. Twelve patients aged 67-94 years were included. All patients were rated as severely ill, 83% were women, with a mean of 12.6 (SD, 1.4) medical comorbidities. Remission was achieved in 75% of the intention-to-treat population and 100% of treatment completers. The number of sessions ranged from 1 to 6, and days until remission from 1 to 16. Patients remained without relapse for 8-28 months. SC ketamine was safe and well tolerated, and most adverse events were mild and transient. Although limited by the retrospective open-label design of the study and small sample size, our findings provide a potential new indication for ketamine: treatment of severe depression, not necessarily resistant to antidepressants, in older patients with multiple medical comorbidities, at risk of clinical deterioration, and referral for ECT. SC ketamine was highly effective in this population, with no relapse and good tolerance. Randomized controlled trials are needed to adequately test the use of ketamine in this specific group.
Asunto(s)
Deterioro Clínico , Trastorno Depresivo Mayor , Terapia Electroconvulsiva , Ketamina , Humanos , Femenino , Anciano , Masculino , Ketamina/efectos adversos , Terapia Electroconvulsiva/efectos adversos , Trastorno Depresivo Mayor/tratamiento farmacológico , Depresión/tratamiento farmacológico , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The Environmental Sensitivity Index (ESI) for oil spills was developed to assist coordinators to evaluate oil spill impact along shorelines and also to coordinate the allocation of resources during and after the incident, aiming to reduce environmental damage and consequences. Recently, Remotely Piloted Aerial Systems (RPAS) are being used in a wide range of areas, since they complement traditional remote sensing data (e.g., satellite images) and offer a rapidly, precise, detail and high-resolution images that fit well for environmental studies. Herein, the use of high-resolution RPAS images for ESI analysis of rocky shores in the Brazilian territory was performed. Using RPAS images, with their higher-resolution compared with ArcGIS Pro Basemap satellite images, increased the detailed of ESI analysis for oil spills, increasing the number of regions in the rocky shore that are more sensitive to oil spills. The RPAS images were able to decrease the number of areas that were less sensitive to oil spills, and increase areas that are more sensitive to oil spills. This increase is important, since they were not detected in the ESI analysis using conventional ArcGIS Pro Basemap satellite images. The RPAS images permit to delineate precisely rocky shores, improving ESI interpretation in rocky shores.
Asunto(s)
Contaminación por Petróleo , BrasilRESUMEN
The Amazonas was one of the most heavily affected Brazilian states by the COVID-19 epidemic. Despite a large number of infected people, particularly during the second wave associated with the spread of the Variant of Concern (VOC) Gamma (lineage P.1), SARS-CoV-2 continues to circulate in the Amazonas. To understand how SARS-CoV-2 persisted in a human population with a high immunity barrier, we generated 1,188 SARS-CoV-2 whole-genome sequences from individuals diagnosed in the Amazonas state from 1st January to 6th July 2021, of which 38 were vaccine breakthrough infections. Our study reveals a sharp increase in the relative prevalence of Gamma plus (P.1+) variants, designated Pango Lineages P.1.3 to P.1.6, harboring two types of additional Spike changes: deletions in the N-terminal (NTD) domain (particularly Δ144 or Δ141-144) associated with resistance to anti-NTD neutralizing antibodies or mutations at the S1/S2 junction (N679K or P681H) that probably enhance the binding affinity to the furin cleavage site, as suggested by our molecular dynamics simulations. As lineages P.1.4 (S:N679K) and P.1.6 (S:P681H) expanded (Re > 1) from March to July 2021, the lineage P.1 declined (Re < 1) and the median Ct value of SARS-CoV-2 positive cases in Amazonas significantly decreases. Still, we did not find an increased incidence of P.1+ variants among breakthrough cases of fully vaccinated patients (71%) in comparison to unvaccinated individuals (93%). This evidence supports that the ongoing endemic transmission of SARS-CoV-2 in the Amazonas is driven by the spread of new local Gamma/P.1 sublineages that are more transmissible, although not more efficient to evade vaccine-elicited immunity than the parental VOC. Finally, as SARS-CoV-2 continues to spread in human populations with a declining density of susceptible hosts, the risk of selecting more infectious variants or antibody evasion mutations is expected to increase. IMPORTANCE The continuous evolution of SARS-CoV-2 is an expected phenomenon that will continue to happen due to the high number of cases worldwide. The present study analyzed how a Variant of Concern (VOC) could still circulate in a population hardly affected by two COVID-19 waves and with vaccination in progress. Our results showed that the answer behind that was a new generation of Gamma-like viruses, which emerged locally carrying mutations that made it more transmissible and more capable of spreading, partially evading prior immunity triggered by natural infections or vaccines. With thousands of new cases daily, the current pandemics scenario suggests that SARS-CoV-2 will continue to evolve and efforts to reduce the number of infected subjects, including global equitable access to COVID-19 vaccines, are mandatory. Thus, until the end of pandemics, the SARS-CoV-2 genomic surveillance will be an essential tool to better understand the drivers of the viral evolutionary process.
Asunto(s)
COVID-19/enzimología , Furina/metabolismo , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Secuencias de Aminoácidos , Brasil/epidemiología , COVID-19/epidemiología , COVID-19/transmisión , COVID-19/virología , Vacunas contra la COVID-19/administración & dosificación , Furina/genética , Genómica , Humanos , Mutación , Filogenia , SARS-CoV-2/clasificación , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/metabolismo , Glicoproteína de la Espiga del Coronavirus/metabolismoRESUMEN
The coronavirus disease COVID-19 has been the cause of millions of deaths worldwide. Among the SARS-CoV-2 proteins, the non-structural protein 1 (NSP1) has great importance during the virus infection process and is present in both alpha and beta-CoVs. Therefore, monitoring of NSP1 polymorphisms is crucial in order to understand their role during infection and virus-induced pathogenicity. Herein, we analyzed how mutations detected in the circulating SARS-CoV-2 in the population of the city of Manaus, Amazonas state, Brazil could modify the tertiary structure of the NSP1 protein. Three mutations were detected in the SARS-CoV-2 NSP1 gene: deletion of the amino acids KSF from positions 141 to 143 (delKSF), SARS-CoV-2, lineage B.1.195; and two substitutions, R29H and R43C, SARS-CoV-2 lineage B.1.1.28 and B.1.1.33, respectively. The delKSF was found in 47 samples, whereas R29H and R43C were found in two samples, one for each mutation. The NSP1 structures carrying the mutations R43C and R29H on the N-terminal portion (e.g. residues 10 to 127) showed minor backbone divergence compared to the Wuhan model. However, the NSP1 C-terminal region (residues 145 to 180) was severely affected in the delKSF and R29H mutants. The intermediate variable region (residues 144 to 148) leads to changes in the C-terminal region, particularly in the delKSF structure. New investigations must be carried out to analyze how these changes affect NSP1 activity during the infection. Our results reinforce the need for continuous genomic surveillance of SARS-CoV-2 to better understand virus evolution and assess the potential impact of the viral mutations on the approved vaccines and future therapies.
Asunto(s)
COVID-19/epidemiología , SARS-CoV-2/genética , Proteínas no Estructurales Virales/genética , Secuencia de Aminoácidos/genética , Sustitución de Aminoácidos/genética , Brasil/epidemiología , Humanos , Polimorfismo Genético/genética , Eliminación de Secuencia/genéticaRESUMEN
The northern state of Amazonas is among the regions in Brazil most heavily affected by the COVID-19 epidemic and has experienced two exponentially growing waves, in early and late 2020. Through a genomic epidemiology study based on 250 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes from different Amazonas municipalities sampled between March 2020 and January 2021, we reveal that the first exponential growth phase was driven mostly by the dissemination of lineage B.1.195, which was gradually replaced by lineage B.1.1.28 between May and June 2020. The second wave coincides with the emergence of the variant of concern (VOC) P.1, which evolved from a local B.1.1.28 clade in late November 2020 and replaced the parental lineage in <2 months. Our findings support the conclusion that successive lineage replacements in Amazonas were driven by a complex combination of variable levels of social distancing measures and the emergence of a more transmissible VOC P.1 virus. These data provide insights to understanding the mechanisms underlying the COVID-19 epidemic waves and the risk of dissemination of SARS-CoV-2 VOC P.1 in Brazil and, potentially, worldwide.
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COVID-19/epidemiología , COVID-19/virología , Genoma Viral/genética , SARS-CoV-2/genética , Adulto , Brasil/epidemiología , Prueba de Ácido Nucleico para COVID-19 , Femenino , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Filogenia , Filogeografía , Análisis Espacio-TemporalRESUMEN
Dentre as 27 Unidades Federativas brasileiras, o estado do Amazonas foi uma das mais afetadas pela presente pandemia do novo coronavírus, com a ocorrência de uma segunda onda ao final de 2020 na qual um grande número de casos graves levou a um colapso no sistema de saúde. Este pre-print, resultado da análise do genoma completo de 250 amostras do SARS-CoV-2 coletadas no Amazonas entre março de 2020 e janeiro de 2021, descreve a dinâmica de sucessões de linhagens dominantes no estado. Mais recentemente, ele foi publicado na revista Nature Medicine, após editoração e a revisão por pesquisadores independentes. A publicação apresenta dados que embasam as hipóteses de que a linhagem responsável pela maioria dos casos no primeiro momento da pandemia (entre março e maio de 2020) foi a B.1.195, de que esta foi suplantada pela B.1.1.28, que tornou-se a linhagem dominante no estado entre maio e dezembro de 2020, e de que em dezembro o surgimento de uma variante da B.1.1.28, denominada P.1 e dotada de maior transmissibilidade, foi responsável pela nova ascensão no número de casos e mortes. Desta forma, a dinâmica local de surgimento de novas genéticas virais foi uma importante força-motriz para a forma com a qual a pandemia avançou sobre o estado do Amazonas, influenciada diretamente pela circulação da população e sua relação com o espalhamento do vírus, que culminou com a substituição da B.1.1.28 pela variante de preocupação P.1 em um processo que acredita-se ter durado apenas dois meses.
RESUMEN
Neste relatório (pre-print), são apresentados três casos de reinfecção causados pela Variante de Preocupação (VOC) P.1, também conhecida como "cepa de Manaus". As três pacientes eram mulheres adultas, e tiveram a primeira infecção durante a primeira onda da pandemia na primeira metade de 2020. Nos três casos, a linhagem detectada no primeiro diagnóstico molecular era diferente da encontrada posteriormente, evidência da reinfecção. Dois dos casos de reinfecção tiveram apresentação de sintomas leves, enquanto o terceiro foi assintomático, apesar de a quantidade de material genético viral detectado sugerir cargas virais elevadas. As evidências aqui apresentadas sugerem que a imunidade após infecção primária por linhagens anteriores à circulação daquelas contendo a mutação E484K não impede uma nova infecção pela variante P.1, e nem mesmo que pessoas reinfectadas por esta variante espalhem o vírus, embora seja possível que tenha protegido estas três pacientes do desenvolvimento de sintomas graves.
RESUMEN
Resumo Este artigo é um recorte de um projeto maior intitulado "O empoderamento do/da adolescente para a promoção da sua saúde no contexto de uma residência multiprofissional". Trata-se de um estudo exploratório e interpretativo de abordagem qualitativa realizado em uma escola pública estadual no contexto de uma Residência Multiprofissional em Saúde do Adolescente em um município de Minas Gerais. O objetivo foi identificar as percepções e escolhas dos(as) adolescentes em relação a sua saúde. Como técnica de coleta de dados, utilizaram-se oficinas com estudantes do Ensino Médio. Os dados foram transcritos na íntegra, submetidos à análise temática e interpretados a partir do referencial teórico da psicologia social. A análise permitiu identificar diferentes temas, organizados em três categorias: "concepções de adolescentes sobre saúde", atreladas sobremaneira ao paradigma biomédico e à corrente moderna de promoção da saúde; "influências nas escolhas e na saúde dos(as) adolescentes", que destacam o papel da família e das relações interpessoais; "Onde os/as adolescentes buscam saúde", que evidencia a internet como lócus primário da busca por informações. As categorias foram discutidas em três eixos: "adolescências, saúde e seus corpos: rascunho ou potência?", "adolescências, influências, escolhas e saúde" e "adolescências, cultura digital e saúde: articulações possíveis". Conclui-se que, para promover saúde durante a adolescência, é preciso despir-se de concepções generalistas e dos ideais de adolescência, extrapolar os espaços tradicionais de cuidado com esse público e considerar profundamente os determinantes sociais em saúde.(AU)
Abstract This paper is an excerpt from a larger project entitled "O Empoderamento do/da Adolescente para a Promoção da sua Saúde no Contexto de uma Residência Multiprofissional" (Empowerment of Adolescents to Promote Health in a Multidisciplinary Context). This is an exploratory and explanatory qualitative study conducted in a public school from a municipality of Minas Gerais, in the context of a Multidisciplinary Residency in Adolescent Health, whose aim was to identify adolescents' perceptions and choices concerning health. Data were collected by means of workshops conducted with High School students, fully transcribed, analyzed according to theme, and interpreted from the theoretical perspective of Social Psychology. Data analysis identified the presence of multiple themes, which were divided into three categories: 'Adolescents' perception on health', associated with the biomedical paradigm as well as to Modern Health Promotion; 'Influences on adolescents' choices and health', which highlights the role of family and interpersonal relationships; and 'Means through which adolescents look for information', which indicates the Internet as a basic locus for information search. These categories were approached from three axes: 'Adolescences, health, and their bodies: drafts or power?'; 'Adolescences, influences, choices, and health'; and 'Adolescences, digital culture, and health: possible articulations'. The results indicate that promoting health among adolescents requires us to break with generic and idealist concepts underlying adolescence, extrapolate the traditional spaces of healthcare aimed at this public, and consider the Social Determinants of Health.(AU)
Resumen Este artículo presenta un recorte de un proyecto más amplio, "O Empoderamento do/ da Adolescente para a Promoção da sua Saúde no Contexto de uma Residência Multiprofissional" ("El empoderamiento del/la Adolescente en la Promoción de la Salud en el Contexto de una Residencia Multiprofesional"). Este es un estudio exploratorio e interpretativo, de metodología cualitativa, realizado en una escuela pública de la red estatal, en el contexto de una Residencia Multiprofesional en Salud del Adolescente, en un municipio de Minas Gerais, Brasil. Su objetivo es analizar las percepciones y elecciones de los/las adolescentes con relación a la salud. La técnica de recolección de datos se basó en la realización de talleres a los cuales acudieron a estudiantes de la secundaria. Los datos obtenidos fueron transcriptos en su totalidad, sometidos a un análisis temático e interpretados desde la psicología social. Este análisis permitió organizar los diferentes temas identificados según tres categorías: "Concepciones de adolescentes sobre la salud", que está vinculada al paradigma biomédico y a la corriente moderna de la promoción de la salud; "Influencias en las elecciones y en la salud de los/las adolescentes", que resalta el rol de la familia y de las relaciones interpersonales; y "Dónde los/las adolescentes buscan salud", que señala que internet es el locus primario para la búsqueda de informaciones. Son tres los ejes que orientan la discusión de dichas categorías: "Adolescencias, salud y sus cuerpos: ¿borrador o potencia?", "Adolescencias, influencias, elecciones y salud"; y "Adolescencias, cultura digital y salud: articulaciones posibles". Se concluye que, para la promoción de la salud en las adolescencias, es necesario romper con concepciones generalistas e idealistas acerca de la adolescencia, ir más allá de los espacios tradicionales de atención a este público y tener en cuenta, sobre todo, los determinantes sociales en salud.(AU)
Asunto(s)
Humanos , Masculino , Femenino , Niño , Adolescente , Conducta del Adolescente , Salud del Adolescente , Promoción de la Salud , Internado no Médico , Psicología Social , Educación Primaria y Secundaria , Análisis de Datos , Empoderamiento , Relaciones InterpersonalesRESUMEN
A new coronavirus [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)] is currently causing a life-threatening pandemic. In this study, we report the complete genome sequencing and genetic characterisation of a SARS-CoV-2 detected in Manaus, Amazonas, Brazil, and the protocol we designed to generate high-quality SARS-CoV-2 full genome data. The isolate was obtained from an asymptomatic carrier returning from Madrid, Spain. Nucleotide sequence analysis showed a total of nine mutations in comparison with the original human case in Wuhan, China, and support this case as belonging to the recently proposed lineage A.2. Phylogeographic analysis further confirmed the likely European origin of this case. To our knowledge, this is the first SARS-CoV-2 genome obtained from the North Brazilian Region. We believe that the information generated in this study may contribute to the ongoing efforts toward the SARS-CoV-2 emergence.
Asunto(s)
Betacoronavirus/genética , Infecciones por Coronavirus/virología , Filogenia , Neumonía Viral/virología , Infecciones Asintomáticas , Brasil , COVID-19 , Genoma Viral , Genómica , Humanos , Mutación , Pandemias , Filogeografía , SARS-CoV-2 , EspañaRESUMEN
A new coronavirus [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)] is currently causing a life-threatening pandemic. In this study, we report the complete genome sequencing and genetic characterisation of a SARS-CoV-2 detected in Manaus, Amazonas, Brazil, and the protocol we designed to generate high-quality SARS-CoV-2 full genome data. The isolate was obtained from an asymptomatic carrier returning from Madrid, Spain. Nucleotide sequence analysis showed a total of nine mutations in comparison with the original human case in Wuhan, China, and support this case as belonging to the recently proposed lineage A.2. Phylogeographic analysis further confirmed the likely European origin of this case. To our knowledge, this is the first SARS-CoV-2 genome obtained from the North Brazilian Region. We believe that the information generated in this study may contribute to the ongoing efforts toward the SARS-CoV-2 emergence.
Asunto(s)
Humanos , Filogenia , Neumonía Viral/virología , Infecciones por Coronavirus/virología , Betacoronavirus/genética , España , Brasil , Genoma Viral , Genómica , Infecciones Asintomáticas , Filogeografía , Pandemias , SARS-CoV-2 , COVID-19 , MutaciónRESUMEN
A experiência da cirurgia é causadora de estresse e ansiedade ao pacietne e à sua família, pelo receio do desconhecido e pelas dúvidas e incertezas quanto ao processo de recuperação. o objetivo deste trabalho foi avaliar a satisfação dos pacientes quanto ao Manual de Orientações Pré e Pós Cirirgia Cardíaca, de modo a propor melhorias e modificação do manual nos próximos exemplares. Trata-se de um estudo de campo, quantitativo, descritivo-exploratório, realizado em um hospital público de São Paulo, especializado no atendimento a pacientes com afecções cardiovasculares...
Asunto(s)
Humanos , Cirugía Torácica/estadística & datos numéricos , Periodo Perioperatorio/enfermería , Periodo Perioperatorio/estadística & datos numéricos , Satisfacción del Paciente/estadística & datos numéricos , Hospitales PúblicosRESUMEN
The TRAPP vesicle-tethering complex consists of more than 10 distinct polypeptides and is involved in protein transport. Using the C2 subunit as bait we identified SPATA4, a spermatocyte-specific protein of unknown function, as an interacting partner in a yeast two hybrid screen. Further studies indicate SPATA4 interacts with the C2 portion of the TRAPP complex. SPATA4 fractionates with both cytosolic and nuclear fractions suggesting it may have several distinct functions. SPATA4 is one of only three human proteins that contain a DUF1042 domain and we show that C2 does not interact with another one of the DUF1042 domain-containing proteins. Our results suggest a role for SPATA4 in membrane traffic and a specialized function for TRAPP in spermatocytes.
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Proteínas de Transporte de Membrana/metabolismo , Proteínas/metabolismo , Factores de Transcripción/metabolismo , Técnicas del Sistema de Dos Híbridos , Humanos , Inmunoprecipitación , Proteínas de Transporte de Membrana/genética , Microscopía Fluorescente , Unión Proteica , Proteínas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Factores de Transcripción/genéticaRESUMEN
The partial characterization and purification of milk clotting enzyme obtained from the (root latex) of Jacaratia corumbensis O. kuntze was studied, by fractional precipitation with ammonium sulphate and ion exchange chromatography. The ammonium sulphate precipitate showed five fractions (AS1- 0-20 percent; AS2 - 20-40 percent; AS3 - 40-60 percent; AS4 - 60-80 percent; AS5 - 80-100 percent) and among the fractions obtained, the 40-60 percent fraction (AS3) showed the highest milk clotting activity with a purification factor of 1.2 fold in relation to the crude extract. This fraction when applied on Mono Q column yielded two protein peaks (p1 and p2), but p1 pool showed the best milk-clotting activity. The optimal pH for the crude and partially purified extract was 6.5 and 7.0, respectively. The maximum milk-clotting activity was at 55ºC for the both crude and partially purified extracts. The enzyme was inhibited by iodoacetic acid which suggested that this enzyme was a cysteine protease, with molecular weight of 33 kDa.
A enzima coagulante de leite obtida de látex de raiz de Jacaratia corumbensis O. kuntze foi caracterizada parcialmente e purificada, por precipitação fracionária com sulfato de amônio e cromatografia de troca de íon. Foram utilizadas cinco frações de sulfato de amônio (AS1 - 0-20 por cento; AS2 - 20-40 por cento; AS3 - 40-60 por cento; AS4 - 60-80 por cento; AS5 - 80-100 por cento), a fração 40-60 por cento (AS3) mostrou alta atividade coagulante com um fator de purificação de 1,2 vezes em relação ao extrato bruto. Esta fração foi aplicada em coluna Mono Q obtendo dois picos de proteína (p1 e p2), o p1 mostrou melhor atividade coagulante. O pH ótimo para o extrato bruto e parcialmente purificado foi 6,5 e 7,0, respectivamente. A atividade coagulante foi atingida a 55ºC para ambos os extratos, bruto e parcialmente purificado. A enzima foi inibida por ácido iodoacético que sugere que esta enzima é uma cisteína protease, com peso molecular de 33 kDa.
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Os autores apresentam uma nova alternativa de isolamento dental aplicável para dentes posteriores em situaçöes onde o isolamento absoluto de forma convencional näo pode ser utilizado. Esse sistema proporciona um melhor isolamento do campo operatório em relaçäo ao isolamento relativo, e apresenta aspectos positivos como: baixo custo, fácil aplicaçäo e näo traumatizantes
Asunto(s)
Dique de GomaRESUMEN
O objetivo deste trabalho foi o de avaliar o comportamento do cálcio iônico no sangue de animais submetidos a retransfusäo rápida de sangue preservado com soluçäo de citrato (CPD-A). Foram estudados ratos divididos em três modelos: modelo A (n=15), controle; modelo B (n=15) com choque hemorrágico (PAM = 30mmHg) durante 10 minutos; modelo C (n=15) com choque hemorrágico seguido de retransfusäo em um período de 10 minutos, com o seu próprio sangue retirado e preservado com CPD-A. Foram colhidas amostras de sangue para gasometria e eletrólitos em: t0 - controle; t10 - após 10 minutos de choque; t20 - final da retransfusäo e t60 - quarenta minutos após t20. Observou-se que em t0 o cálcio iônico foi igual para A,B e C. O modelo controle näo teve alteraçöes dos níveis de cálcio durante todo o experimento. Todos os animais submetidos ao choque (BeC) tiveram uma elevaçäo do cálcio iônico em t10. Em t20, o modelo B manteve os níveis de cálcio inalterados enquanto que os animais que receberam retransfusäo exibiram uma hipocalcemia importante (de 0,75 + 0,16mEq/L para 0,35 + 0,17mEq/L). Em t60 todos os animais apresentaram níveis de cálcio semelhantes aos iniciais. Dois animais do modelo C morreram no final da retransfusäo. Estes animais apresentaram hipocalcemia iônica grave (0,10mEq/L e 0,18mEq/L) juntamente com hipernatremia (156mEq/L e 159mEq/L). Conclue-se que a transfusäo rápida de sangue citratado se acompanha de grave, embora transitória hipocalcemia iônica. A esta alteraçäo é atribuída a morte de dois animais no modelo retransfundido. Infere-se que no ser humano a transfusäo rápida de sangue deve ser acompanhada de administraçäo de cálcio.