Small-molecule anti-COVID-19 drugs and a focus on China's homegrown mindeudesivir (VV116) / 医学前沿

The coronavirus disease 2019 (COVID-19) pandemic has stimulated tremendous efforts to develop therapeutic agents that target severe acute respiratory syndrome coronavirus 2 to control viral infection. So far, a few small-molecule antiviral drugs, including nirmatrelvir-ritonavir (Paxlovid), remdesivir, and molnupiravir have been marketed for the treatment of COVID-19. Nirmatrelvir-ritonavir has been recommended by the World Health Organization as an early treatment for outpatients with mild-to-moderate COVID-19. However, the existing treatment options have limitations, and effective treatment strategies that are cost-effective and convenient for tackling COVID-19 are still needed. To date, four domestically developed oral anti-COVID-19 drugs have been granted conditional market approval in China. These drugs include azvudine, simnotrelvir-ritonavir (Xiannuoxin), leritrelvir, and mindeudesivir (VV116). Preclinical and clinical studies have explored the efficacy and tolerability of mindeudesivir and supported its early use in mild-to-moderate COVID-19 cases at high risk for progression. In this review, we discuss the most recent findings regarding the pharmacological mechanism and therapeutic effects focusing on mindeudesivir and other small-molecule antiviral agents for COVID-19. These findings will expand our understanding and highlight the potential widespread application of China's homegrown anti-COVID-19 drugs.

Characteristics of N6-methyladenosine modification patterns in t(8;21) acute myeloid leukemia / 南方医科大学学报

OBJECTIVE@#To investigate the relationship between AML1-ETO (AE) fusion gene and intracellular N6-methyladenosine (m6A) modification pattern in t(8;21) acute myeloid leukemia (AML).@*METHODS@#RNA m6A sequencing was performed in SKNO-1 and AE knockdown SKNO-1 (SKNO-1 siAE) cells using RNA-protein co-immunoprecipitation and high-throughput sequencing (methylated RNA immunoprecipitation sequencing, MeRIP-Seq) to analyze the changes in m6A modification of the entire transcriptome. Transcriptome sequencing (RNA-seq) was performed using high-throughput sequencing. The differentially modified mRNAs were further functionally annotated by Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The changes in m6A-related enzyme expressions were detected using real-time PCR.@*RESULTS@#A total of 26 441 genes were identified in AE knockdown AML cells and AE-expressing cells, containing 72 036 m6A peaks. AE knockdown caused a reduction of the number of intracellular m6A peaks from 37 042 to 34 994, among which 1278 m6A peaks were significantly elevated and 1225 were significantly decreased; 1316 genes with newly emerged m6A modification were detected and 1830 genes lost m6A modification after AE knockdown. The differential peaks were mainly enriched in pathways involving cancer and human T-lymphocytic leukemia virus I. RNA-seq results showed that 2483 genes were up-regulated and 3913 genes were down-regulated after AE knockdown. The combined analysis of MeRIP-Seq and RNA-Seq results revealed relatively high expression levels of m6A-modified genes as compared with the genes without m6A modification (SKNO-1: 0.6116±1.263 vs 2.010±1.655, P < 0.0001; SKNO-1 siAE: 0.5528±1.257 vs 2.067±1.686, P < 0.0001). The m6A modified genes located in the 3'UTR or 5 'UTR had significantly higher expression levels than those located in exonic regions (SKNO-1: 2.177± 1.633 vs 1.333 ± 1.470 vs 2.449 ± 1.651, P < 0.0001; SKNO-1 siAE: 2.304 ± 1.671 vs 1.336 ± 1.522 vs 2.394 ± 1.649, P < 0.05). Analysis of RNA-seq data identified 3 m6A-related enzymes that showed significantly elevated mRNA expression after AE knockdown, namely WTAP, METTL14, and ALKBH5 (P < 0.05), but the results of real-time PCR showed that the expressions of WTAP and ALKBH5 were significantly increased while the expression of METTL14 was lowered after AE knockdown (P < 0.05).@*CONCLUSION@#AE knockdown results in differential expressions of m6A-associated enzymes, suggesting that the AE fusion gene regulates the expression of one or more m6A-associated enzymes to control cellular methylation levels.

Remdesivir en pacientes con COVID-19 (8 maio 2020) / Remdesivir in COVID-19 Patients (May 8, 2020)

CONTEXTO CLÍNICO: La Enfermedad por el Coronavirus 2019 (COVID­19, por su sigla en inglés Coronavirus Disease 2019) es una enfermedad respiratoria de humanos producida por un nuevo coronavirus identificado con la sigla SARS-CoV-2. El 11 de marzo de 2020 la Organización Mundial de la Salud (OMS) declaro la COVID-19 como una pandemia. Desde ese momento hasta este 01 de abril su circulación se ha reportado en 205 países reportándose más de 800.000 casos y la muerte 40.000 personas. TECNOLOGÍA: Remdesivir (GS-5734) es un profármaco análogo de la adenosina que compite preferentemente por el ATP viral y se incorpora como falso nucleósido a la nueva cadena del ARN viral. Al incorporarse a las cadenas de ARN virales durante su replicación da como resultado la terminación prematura de la misma. La dosis de inicio recomendada es de 200 mg administrada de manera endovenosa el primer día, seguido de 100mg una vez al día durante 9 días. OBJETIVO: El objetivo del presente informe es evaluar la evidencia disponible acerca de la eficacia, seguridad y aspectos relacionados a las políticas de cobertura del uso de remdesivir para el tratamiento de la COVID­19. MÉTODOS: Se realizó una búsqueda en las principales bases de datos bibliográficas, en buscadores genéricos de internet, y financiadores de salud. Se priorizó la inclusión de revisiones sistemáticas (RS), ensayos clínicos controlados aleatorizados (ECAs), evaluaciones de tecnologías sanitarias (ETS), evaluaciones económicas, guías de práctica clínica (GPC) y políticas de cobertura de diferentes sistemas de salud. RESULTADOS: Se incluyeron un ECA, un estudio observacional, y nueve GPC sobre el tratamiento de pacientes con diagnóstico de COVID­19. CONCLUSIONES: Evidencia de baja calidad proveniente de un ensayo clínico aleatorizado, detenido prematuramente sugiere que el uso de remdesivir no estaría asociado a una disminución de la mortalidad, o del tiempo a la mejoría clínica en pacientes con COVID-19. Múltiples ensayos clínicos aleatorizados en pacientes con cuadros moderados o severos se encuentran en curso. Actualmente las principales guías de práctica clínica y recomendaciones de las principales sociedades internacionales, organismos gubernamentales o consensos de expertos no lo mencionan ni lo recomiendan para el tratamiento de estos pacientes, siendo su uso restringido a estudios de investigación. No se encontraron estudios de costo-efectividad o de impacto presupuestario en Latinoamérica.

Eficacia y seguridad de ticagrelor como monoterapia de primera linea en pacientes con sindrome coronario agudo, intervención percutánea, e intolerancia a la aspirina / Efficacy and safety of ticagrelor as first-line monotherapy in patients with acute coronary syndrome, percutaneous intervention, and aspirin intolerance

INTRODUCCIÓN: Antecedentes: El presente dictamen expone la evaluación de tecnología sanitaria de la eficaica y seguridad de Ticagrelor como monoterapia de primera línea en pacientes con síndrome coronario agudo, intervención percutànea e intolerancia a la aspirina. Aspectos Generales: El síndroem coronario agudo (SCA) es una condición en la que se manifestan síntomas de isquemia cardíaca aguda y tiene forma variadas de presentatación. Los síndromes coronarios agudos como infarto agudo de miocardio con elevación del segmento ST (IAMCEST), infarto de miocardio sin elevación sin elevación ST (IAMSEST) y la angina inestable compaten una fisiopatologia común: la rotura o erosión de una placa de ateroma con trombosis intracoronaria superpuesta (aterotrombosis). Tecnología Sanitaria de Interés: Dentro de los tratamientos farmacológicos para el síndrome coronario agudo se Ticagrelor: un derivado pirimidínico antiplaquetario oral de nueva generación, el cual se une reversiblemente al receptor adenosino difosfato P2Y inhibiendo así la activación y agregación plaquetaria. Tiene un mecanismo de iniciación, acción y finalización más rápido que su similar Clopidogrel y es considerado un tratamiento de primera línea en algunos países del primer mundo. METODOLOGÍA: Estrategia de Búsqueda: Se realizó una estrategia de búsqueda de la evidencia científica con respecto a ticagrelor como monoterapia línea en pacientes con síndrome coronario agudo intervención percutánea e intolerancia a la aspirina. Para la búsqueda primaria se revisó la información disponible por entes reguladoras y normaltivas como la Food Adminstration (FDA), y la Dirección General de Medicamentos y Drogas (DIGEMID). Posteriomente se buscaron Guías de Práctica Clínica a través de los metabuscadores: Translating Research into Practice (TRIPDABATASE) National Library of Medicine (Pubmed-Medline), The National Guideline of Clearinghouse, y Health Systems Evidence. Finalmente, se realizó una búsqueda dentro de la información generada por grupos internacionales que realizan revisiones sistemáticas, evaluación de tecnologías sanitarias y guías de práctica clínica, tales como The Cochrane Library, The National Institute for Health and Care Excellence (NICE), The Canadian Agengy for Drugs and Technologies in Health (CADTH), The Scottish Medicines Consortium (SMC), que a su vez fue complementada con una búsqueda en www.clinicaltrials.gov y www.clinicaltrialsregister.eu para indentificar estudios primarios en elaboración o que no hayan sido publicados aún. Se realizó además una búsqueda manual con una estrategia de "bola de nieve" mediante la revisión de listas de referencias de las guías, evaluaciones de tecnologías, estudios primarios y revisiones narrativas seleccionados. RESULTADOS: Sinopsis de la Evidencia: Se realizó la búsqueda y revisión de la evidencia científica actual para la evaluación de la eficacia y seguridad de ticagrelor como monoterapia de primera línea en pacientes con síndrome coronoario agudo, intervención percutánea e intolerancia a la aspirina. CONCLUSIONES: La pregunta PICO de interés se centra en presentear evidencia que evalúe directamente el uso de ticagrelor como monoterapia de primera línea en pacientes con contraindicación al uso de aspirina además de poseer riesgo de desarrollar trombosis de stent debido a intervención percutánea. En la actualidad, el petitorio de Essalud cuenta con la terapia estándar de tratamiento para síndrome coronario agudo clopidogrel en combinación con aspirina, terapia que es empleada como primera alternativa de elcción para el manejo de pacientes con síndrome coronario agudo. Ticargrelo requiere demostrar un beneficio clínico considerablemente superior como monoterapia para el paciente no cubierto por clopidogrel. No se encontró evidencia directa que responda a la pregunta PICO de interés. Especificamente, se encontraron guías de práctica clínica para el manejo general de SCA, sin embargo ninguna menciona recomendaciones para el manejo de los casos de alergia a la aspirina o del cambio de la terpia combinada a una monoterapia en el tratamiento de SCA. En el balance riesgo-beneficio de ticagrelor, el benefício clínico mínimo que la terapia con ticagrelor (2% anual) habla de un beneficio neto muy modesto frente a clopidogrel, lo que añadido a los riesgos de eventos adversos, la adherencia a la terapia, y la diferencia de costo 56 veces mayor, no permite establecer que las ganancias atribuibles al ticagrelor son de relativo significativo clínico desde la perspectiva del paciente como lo son disminución de mortalidad por causas vasculares, prevenir la necesidad de revascularización, evitar la rehospitalización y mejorar la calidad de vida. Esto limita seriamente la posibilidad de recomendar el uso de este medicamento sobretodo en el contexto en el que se cuenta aún con una alternativa de similar eficacia en el Petitorio Farmacológico de Essalud. El Instituto de Evaluación de Tecnologías en Salud e Investigación-IETSI, no aprueba el uso Ticagrelor como monoterapia de primera línea en pacientes con síndroem coronario agudo, intervención percutánea e intolerancia a la aspirina.

Eficacia y seguridad de ticagrelor en pacientes con re-infarto por trombosis de stent for falla a la terapia de soble antiagregación plaquetária clopidogrel más aspirina / Efficacy and safety of ticagrelor in patients with re-infarction due to stent thrombosis for failure of soble antiplatelet therapy clopidogrel plus aspirin

INTRODUCCIÓN: Antecedentes: El presente dictamen expone la evaluación de tecnología sanitaria de la eficacia y seguridad de Ticagrelor en pacientes con re-infarto por trombosis de stent por falla a la terapia de doble antiagregación plaquetaria clopidogrel más aspirina. Aspectos Generales: El síndrome coronario agudo (SCA) es una condición en la que se manifestan síntomas de isquemia cardíaca y, clinicamente, se presentan de manera heterogénea. Los síndromes coronarios agudos como infarto agudo de miocardio con elevación del segmento ST (IAMCEST) y la angina inestable comparten una fisiopatología común: la rotura o erosión de una placa de ateroma con trombosis intracoronaria superpuesta (aterotrombosis). Tecnología Sanitaria de Interés: Dentro de los tratamientos farmacológicos para el síndrome coronario agudo el Ticagrelor: un derivado pirimidínico antiplaquetario oral de nueva generación, el cual se une reversiblemente al receptor adenosino difosfato P2Y inhibiendo así la activación y agregación plaquetaria. Tiene un mecanismo de iniciación, acción y finalización más rápido que su similar clopidogrel y es considerado un tratamiento de primera línea en algunos países del primer mundo. METODOLOGÍA: Estrategia de Búsqueda: Se realizó una estrategia de búsqueda sistemática de la evidencia científica con respecto a Ticagrelor en pacientes con ref-infarto por trombosis de stent y falla a la terapia de doble antiagregación plaquetaria clopidogrel más aspirina. Para la búsqueda primaria se revisó la información disponible por entes reguladoras y normativas como la Food and Drug Administration (FDA), y la Dirección General de Medicamentos y Drogas (DIGEMID). Posteriormente se buscaron Guías de Práctica Clínica a través de los metabuscadores: Translating Research into Practice (TRIPDATABASE), National Library Systems Evidence. Finalmente, se realizó una búsqueda dentro de la información generada por grupos internacionales que realizan revisiones sistemáticas, evaluación de tecnologías sanitarias y guías de práctica clínica, tales como The Cochrane Library, The National Institute for Health and Care Excellence (NICE), The Canadian Agency for Drugs and Technologies in Health (CADTH), The Scottish Medicines Consortium (SMC). Se realizó además una búsqueda manual con una estrategia de bola de nieve mediante la revisión de listas de referencias de las guías, evaluaciones de tecnologías estudios primarios y revisiones narrativas seleccionados. RESULTADOS: Sinopsis de la Evidencia: Se realizó la búsqueda y revisión de la evidencia científica actual para la evaluación de la eficacia y seguridad de Ticagrelor en pacientes con re-infarto por trombosis de stent y falla a la terapia de doble antiagregación plaquetaria clopidogrel más aspirina. La evidencia disponible a la actualidad sobre el uso de ticagrelor recae en un único ensayo clínico aleatorizado (ECA) fase III, el estudio PLATO 2009 de Wallentin et al., a partir del cual se emiten todas las recomendaciones en guías de práctica clínica, evaluaciones de tecnología sanitaria, y análisis exploratórios secundarios. CONCLUSIONES: En la actualidad, el Petitorio Farmacológico de Esalud cuenta con la terapia estándar de tratamiento para síndrome coronario agudo: clopidogrel en combinación con aspirina, terapia que es empleada como primera alternativa de elección para el manejo de pacientes con el diagnóstico mencionado. A la fecha, no existe alternativa de tratamiento a clopidogrel en el petitorio de ESSalud, por lo que es necesario contar con una alternativa para aquellos pacientes en alto riesgo de muerte al haber sufrido re-infarto al miocardio por trombosis de stent a pesar de encotrarse en terapia con clopidogrel más aspirina, a dosis tope y durante un tiempo de tratamiento adecuado. El Instituto de Evaluación de Tecnologías en Salud e Invstigación-IETSI, aprueba el uso de Ticagrelor en pacientes con re-infarto por trombosis de stent y falla a la terapia de doble antiagregación plaquetaria clopidogrel más aspirina.

Cost-effectiveness analysis of ticagrelor compared to clopidogrel for the treatment of patients with acute coronary syndrome in Colombia / Análisis de costo-efectividad del ticagrelor en comparación con el clopidogrel para el tratamiento de pacientes con síndrome coronario agudo en Colombia

Introduction: Acute coronary syndrome is one of the most frequent medical emergencies in developing countries. Objective: To determine, from the perspective of the Colombian health system, the cost-effectiveness of ticagrelor compared to clopidogrel for the treatment of patients with acute coronary syndrome. Materials and methods: We conducted a cost-effectiveness analysis from the perspective of the Colombian health system comparing ticagrelor and clopidogrel for the treatment of patients with acute coronary syndrome. To estimate the expected costs and outcomes, a Markov model was constructed in which patients could remain stable without experiencing new cardiovascular events, suffer from a new event, or die. For the baseline case, a 10-year time horizon and a discount ratio of 3% for costs and benefits were adopted. The transition probabilities were extracted from the PLATO (Platelet Inhibition and Patient Outcomes) clinical trial. Vital statistics were drawn from the Departmento Administrativo Nacional de Estadística (DANE) and additional information from Colombian patients included in the Access registry. To identify and measure resource use, a standard case was built by consulting guidelines and protocols. Unit costs were obtained from Colombian rate lists. A probabilistic sensitivity analysis was conducted in which costs were represented by a triangular distribution, and the effectiveness through a beta distribution. Results: In the base case, the additional cost per quality-adjusted life-year gained with ticagrelor was COP$ 28,411,503. The results were sensitive to changes in the time horizon and the unit cost of clopidogrel. For a willingness-to-pay equivalent to three times the Colombian per capita gross domestic product, the probability of ticagrelor being cost-effective was 75%. Conclusions: Ticagrelor is a cost-effective strategy for the treatment of patients with acute coronary syndrome in Colombia.

Introducción. El síndrome coronario agudo es una de las emergencias médicas más frecuentes en los países en desarrollo. Objetivo. Determinar, desde la perspectiva del sistema de salud colombiano, la relación de costo-efectividad del ticagrelor comparado con el clopidogrel para el tratamiento de pacientes con síndrome coronario agudo. Materiales y métodos. Se hizo un análisis de costo-efectividad desde la perspectiva del sistema de salud colombiano, comparando el ticagrelor y el clopidogrel para el tratamiento de pacientes con síndrome coronario agudo. Para estimar los costos y resultados esperados de las dos alternativas, se construyó un modelo de Markov en el cual los pacientes podían permanecer estables sin experimentar nuevos eventos cardiovasculares, sufrir de un nuevo evento coronario o morir. Para el caso de base, se adoptó un horizonte temporal de 10 años y una tasa de descuento de 3 % para los costos y beneficios. Las probabilidades de transición se extrajeron del estudio Platelet Inhibition and Patient Outcomes , PLATO. Las estadísticas vitales se consultaron en informes del Departamento Administrativo Nacional de Estadística (DANE) y los parámetros adicionales del modelo se basaron en la información de los pacientes colombianos incluidos en el registro en Access. Para identificar y medir el uso de recursos, se construyó un caso estándar a partir de guías y protocolos. Los costos unitarios se obtuvieron de manuales tarifarios colombianos. Se hizo un análisis de sensibilidad probabilístico en el que los costos se representaron por una distribución triangular y, las probabilidades de transición, mediante una distribución beta. Resultados. En el caso de base, el costo adicional por años de vida ajustados por calidad ganados con el ticagrelor fue de COP$ 28´411.503. Los resultados fueron sensibles a los cambios en el horizonte temporal y al costo unitario del clopidogrel. Para un umbral de costo-efectividad equivalente a tres veces el producto interno bruto per cápita de Colombia, la probabilidad de que el ticagrelor fuera costo-efectivo fue de 75 %. Conclusiones. El ticagrelor es una estrategia costo-efectiva para el tratamiento de los pacientes con síndrome coronario agudo en Colombia.

Assistência fisioterapêutica na atenção primária à saúde infantil: uma revisão das experiências / Physical therapy in pediatric primary care: a review of experiences

OBJETIVO: Revisar as experiências de atenção fisioterapêutica dirigidas à população pediátrica descritas na literatura e analisar a produção de conhecimento sobre fisioterapia no contexto da atenção primária à saúde infantil (APSI). MÉTODOS: Foi realizada uma revisão sistemática conforme PRISMA, com busca nas seguintes bases de dados: MEDLINE, LILACS, SciELO, PubMed, Scopus, Cochrane; banco de teses da CAPES; e System for Information on Grey Literature in Europe (SIGLE). Foram utilizados os descritores "atenção primária à saúde", "fisioterapia", "lactente ou criança" e seus correspondentes na língua inglesa e espanhola, sem restrição de ano de publicação. RESULTADOS: Analisamos 13 artigos de seis países, reunidos em três eixos temáticos: dilemas profissionais (três artigos), competências e habilidades específicas para a APSI (sete artigos) e relatos de prática (quatro artigos). Os dilemas profissionais mencionados foram a ampliação do papel do fisioterapeuta para incluir ambientes comunitários, compartilhando a tomada de decisão com as famílias, e o trabalho em colaboração com outros serviços de saúde para identificar as necessidades da criança. As competências e habilidades citadas foram a identificação de sintomas clínicos e socioculturais para além das condições musculoesqueléticas, o diagnóstico fisioterapêutico precoce, a prevenção contra o uso excessivo de medicamentos e a capacidade de trabalhar em equipe. Os relatos de prática discorreram sobre estimulação em crianças com quadros neurológicos, tratamento respiratório e grupos com mães de crianças com esses acometimentos. CONCLUSÕES: O baixo número de estudos sugere desconhecimento quanto ao modo como a fisioterapia se insere na APSI e, provavelmente, quanto às habilidades profissionais necessárias nesse ambiente. Assim, são necessários mais estudos para fornecer dados sobre a área e um esforço de qualificação continuada por parte dos fisioterapeutas.

OBJECTIVE: To review pediatric physical therapy experiences described in the literature and to analyze the production of knowledge on physical therapy in the context of pediatric primary health care (PPHC). METHODS: A systematic review was conducted according to the PRISMA criteria. The following databases were searched: MEDLINE, LILACS, SciELO, PubMed, Scopus and Cochrane; Brazilian Ministry of Health's CAPES doctoral dissertations database; and System for Information on Grey Literature in Europe (SIGLE). The following search terms were used: ["primary health care" and ("physical therapy" or "physiotherapy") and ("child" or "infant")] and equivalent terms in Portuguese and Spanish, with no restriction on publication year. RESULTS: Thirteen articles from six countries were analyzed and grouped into three main themes: professional dilemmas (three articles), specific competencies and skills required in a PPHC setting (seven articles), and practice reports (four articles). Professional dilemmas involved expanding the role of physical therapists to encompass community environments and sharing the decision-making process with the family, as well as collaborative work with other health services to identify the needs of children. The competencies and skills mentioned in the literature related to the identification of clinical and sociocultural symptoms that go beyond musculoskeletal conditions, the establishment of early physical therapy diagnoses, prevention of overmedication, and the ability to work as team players. Practice reports addressed stimulation in children with neurological diseases, respiratory treatment, and establishing groups with mothers of children with these conditions. CONCLUSIONS: The small number of studies identified in this review suggests that there is little knowledge regarding the roles of physical therapists in PPHC and possibly regarding the professional abilities required in this setting. Therefore, further studies are required to provide data on the field, along with a continuing education effort on the part of physical therapists.

Ticagrelor en el síndrome coronario agudo. Explicando lo inexplicable / [Ticagrelor in acute coronary syndrome. Explaining the inexplicable]

The PLATO study evaluated the efficacy of adding ticagrelor, instead of clopidogrel, to aspirin in patients with acute coronary syndrome, which showed surprisingly positive results making the drug acceptable to regulatory agencies and specialty societies worldwide. Notwithstanding the aforementioned success, contradictory information supplied by critical analysis was submitted by the sponsor. The controversial findings revealed several aspects that are difficult to explain, threatening the veracity of the study’s conclusions. Mortality rate pattern, excessive benefit not comparable to prior studies, unexplained loss of follow-up development and inconsistency in findings in accordance with the country, the type of events arbitrator and monitoring committee are some of the most questionable issues. Dubious reaction to this trial is based on the fact that the information could not be found in published articles. This complex situation poses a challenge to the critical analysis of the text and raises questions as to how far the conflicts of financial interest influenced the development of the study, the communication of its results and probably, acceptance of the drug for commercial use.

Evaluation of different methods to detect methicillin resistance in Staphylococcus aureus [MRSA]

The studies suggest that dogs living with human are potential risk of becoming MRSA carrier and increased risk of infections caused by MRSA. Phenotypic methods to detect methicillin resistance in Staphylococcus aureus [MRSA] are inadequate. The objective of the present study was to determine methicillin resistance in S. aureus by phenotypic susceptibility test [oxacillin disk diffusion, cefoxitin disk diffusion, oxacillin screen agar] and molecular methods [PCR as a gold standard] and the latex agglutination test for the detection of PBP2a and to evaluate the results of these tests for its sensitivity and specificity. A total of 100 swab samples were taken from muzzle site, in more contact with human, of dogs and MRSA were isolated. Oxacillin [1 micro g], cefoxitin [30 micro g] disk diffusion and oxacillin screen agar method were used. The isolates were also subjected to latex agglutination test for detection of PBP2a and PCR to detect mecA gene. By PCR 37% of isolates show the presence of mecA. Latex agglutination was found to be the most sensitive [97.29%] and cefoxitin disk diffusion to be the most specific [96.82%] tests for detection of MRSA. Our finding showed that combining oxacillin screen agar or cefoxitin disk diffusion with latex agglutination improves sensitivity and specificity to detect methicillin resistance S. aureus [MRSA] isolates

Receptores plaquetários P2Y12: importância na intervenção coronariana percutânea / P2Y12 platelet receptors: importance in percutaneous coronary intervention

As plaquetas estão envolvidas em vários processos biológicos, desde o combate a agentes infecciosos até a coordenação do controle da permeabilidade vascular e angiogênese. Entretanto, o seu principal foco de ação consiste na modulação da cascata de coagulação. A intervenção coronariana percutânea é um procedimento com alto risco trombogênico, que induz a ativação plaquetária e de monócitos, devido à lesão direta do endotélio e pelo contato de estruturas trombogênicas com o sangue, levando ao aumento da atividade inflamatória, tanto no local do dano vascular coronariano como de forma sistêmica. Os receptores plaquetários P2Y12 desempenham papel central na amplificação da agregação induzida por todos os agonistas plaquetários, como a adenosina difosfato, o colágeno, tromboxano A2, adrenalina e serotonina. Por esse motivo, têm sido o principal alvo das drogas antiplaquetárias. Apesar de atuarem no mesmo receptor, características farmacocinéticas e farmacodinâmicas distintas conferem peculiaridades a cada agente.

Apart from their role in hemostasis and thrombosis, platelets are involved in many other biological processes such as wound healing and angiogenesis. Percutaneous coronary intervention is a highly thrombogenic procedure inducing platelets and monocytes activation through endothelial trauma and contact activation by intravascular devices. Platelet P2Y12 receptor activation by adenosine diphosphate facilitates non-ADP agonist-mediated platelet aggregation, dense granule secretion, procoagulant activity, and the phosphorylation of several intraplatelet proteins, making it an ideal drug target. However, not all compounds that target the P2Y12 receptor have similar efficacy and safety profiles. Despite targeting the same receptor, the unique pharmacologic properties of each of these P2Y12 receptor-directed compounds can lead to very different clinical effects.

P2Y12 inhibitors in acute coronary syndromes: Which and when.

Acute coronary syndromes (ACS) are the commonest acute manifestation of coronary artery disease and a major cause of hospitalization and death. Plaque rupture and subsequent platelet activation are the key factors in its pathogenesis. Platelet inhibitors are crucial in the management of ACS. Aspirin remains the standard antiplatelet but use of dual antiplatelet drugs is beneficial in ACS. Platelet P2Y12 receptor inhibitors are an important group of antiplatelet compounds that can be combined with aspirin in the management of ACS. P2Y12 inhibitors may belong to the thienopyridine or nonthienopyridine group of compounds. The former (clopidogrel, prasugrel) combine irreversibly with the receptor and therefore have a prolonged duration of action. On the other hand, the non-thienopyridine compounds (ticagrelor, elinogrel) have a reversible action and hence a shorter duration of action. Several new compounds in this group have become or are likely to become available. The newer agents have a more uniform and complete antiplatelet effect and are much less likely to be affected by genetic variability of CYP2C19 enzyme activity compared with that of clopidogrel. Large phase 3 trials have shown that ticagrelor and prasugrel reduce major cardiovascular events in ACS compared to clopidogrel when given in addition to aspirin. This is accompanied by some increase in bleeding. This review discusses the properties, clinical profile and possible place of P2Y12 receptor inhibitors in clinical practice.

Selective inhibitory effect of adenosine A1 receptor agonists on the proliferation of human tumor cell lines

In this study, the effects of three structural analogues of adenosine upon proliferation of human tumor cells were investigated. Previous research showed a cytotoxic effect of adenosine via A3 receptor and A[1] receptor and sometimes this effect was receptor independent. The researches showed a differential cytotoxic effect of adenosine and its A[3] agonists on cancerous cells, while other studies demonstrated tumor promoting effect of adenosine and its A[1] agonists. The purpose of the present study was the evaluation of the possible selective anti-tumor effect of A1 receptor agonists on cancerous cells. The substances of N6-cyclohexyl-adenosine [CHA, A[1] agonist], R-isomer of N6-phenylisopropyladenosine [R-PIA, A[1] agonist] and N5-ethylcarboxamido-adenosine [NECA, adenosine A[1]-A[2] non-specific agonist] were tested for their anti-proliferative effect using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide [MTT] assay method. Hep G2, Hep2, CACO2, ACHN and L929 cell lines were used in this assay. CHA inhibited cell proliferation in three cell lines [in concentration of 5-50 micro M] and R-isomer of R-PIA in one cell line [in concentration of 10-50 micro M]. These effects were inhibited partially by addition of 1,3-Dipropyl-8-cyclopentylxanthine [A1 antagonist]. The NECA analogue had no inhibitory effect on the cell proliferations. All of the substances had no cytotoxic effect on L929 cells [mouse connective tissue fibroblast cell line]. CHA and R-PIA had inhibitory effect on the proliferation of human tumor cell lines partially via A1 receptor, while they didn't show such effect on fibroblast cells. These results suggest that A[1] adenosine receptor agonists have a good potential of specific anti-tumor activity

Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary

In previous studies, we demonstrated biphasic purinergic effects on prolactin (PRL) secretion stimulated by an adenosine A2 agonist. In the present study, we investigated the role of the activation of adenosine A1 receptors by (R)-N6-(2-phenylisopropyl)adenosine (R-PIA) at the pituitary level in in vitro PRL secretion. Hemipituitaries (one per cuvette in five replicates) from adult male rats were incubated. Administration of R-PIA (0.001, 0.01, 0.1, 1, and 10 æM) induced a reduction of PRL secretion into the medium in a U-shaped dose-response curve. The maximal reduction was obtained with 0.1 æM R-PIA (mean ± SEM, 36.01 ± 5.53 ng/mg tissue weight (t.w.)) treatment compared to control (264.56 ± 15.46 ng/mg t.w.). R-PIA inhibition (0.01 æM = 141.97 ± 15.79 vs control = 244.77 ± 13.79 ng/mg t.w.) of PRL release was blocked by 1 æM cyclopentyltheophylline, a specific A1 receptor antagonist (1 æM = 212.360 ± 26.560 ng/mg t.w.), whereas cyclopentyltheophylline alone (0.01, 0.1, 1 æM) had no effect. R-PIA (0.001, 0.01, 0.1, 1 æM) produced inhibition of PRL secretion stimulated by both phospholipase C (0.5 IU/mL; 977.44 ± 76.17 ng/mg t.w.) and dibutyryl cAMP (1 mM; 415.93 ± 37.66 ng/mg t.w.) with nadir established at the dose of 0.1 æM (225.55 ± 71.42 and 201.9 ± 19.08 ng/mg t.w., respectively). Similarly, R-PIA (0.01 æM) decreased (242.00 ± 24.00 ng/mg t.w.) the PRL secretion stimulated by cholera toxin (0.5 mg/mL; 1050.00 ± 70.00 ng/mg t.w.). In contrast, R-PIA had no effect (468.00 ± 34.00 ng/mg t.w.) on PRL secretion stimulation by pertussis toxin (0.5 mg/mL; 430.00 ± 26.00 ng/mg t.w.). These results suggest that inhibition of PRL secretion after A1 receptor activation by R-PIA is mediated by a Gi protein-dependent mechanism.

Regulation of trehalose metabolism by Adox and AdoMet in Saccharomyces cerevisiae.

Effect of a potent methylation inhibitor oxidized adenosine (Adox), and a universal methyl group donor S-adenosyl-L-methionine (AdoMet) on trehalose metabolism was studied in two haploids of S. cerevisiae of mating types MATalpha, met3 (6460 -8D) and MATa, leu2, ura3, his4 (8534 -10A). Trehalose level decreased in presence of Adox in both strains. Both neutral trehalase (NT) and trehalose-6-phosphate (tre-6-p) synthase activities increased in presence of Adox in -8D strain. Decrease in trehalose level in -8D thus could not be explained in the light of increased tre-6-p synthase activity; however, it could be correlated with increased NT activity. In strain -10A, NT activity was reduced in presence of Adox while tre-6-p synthase activity increased. Enzyme activity profiles in -10A thus do not explain the reduced trehalose level on Adox treatment. Effect of AdoMet was not very prominent in either strain, though in -8D a small increase in trehalose level was seen on treatment. Intracellular AdoMet level of untreated cells of -10A was seen to be almost six times higher than that of -8D. Further, AdoMet treatment caused increase in its level compared to untreated cells, suggesting AdoMet uptake. No effect of either compound was seen on acid trehalase (AT) activity in any strain. The results suggest that there was a possible effect of demethylation on trehalose metabolism (particularly in the synthetic direction) in both strains, though effect of methylation was not very prominent, the reason for which is not very clear.

Possible involvement of A1 receptors in the inhibition of gonadotropin secretion induced by adenosine in rat hemipituitaries in vitro

We investigated the participation of A1 or A2 receptors in the gonadotrope and their role in the regulation of LH and FSH secretion in adult rat hemipituitary preparations, using adenosine analogues. A dose-dependent inhibition of LH and FSH secretion was observed after the administration of graded doses of the R-isomer of phenylisopropyladenosine (R-PIA; 1 nM, 10 nM, 100 nM, 1 µM and 10 µM). The effect of R-PIA (10 nM) was blocked by the addition of 8-cyclopentyltheophylline (CPT), a selective A1 adenosine receptor antagonist, at the dose of 1 µM. The addition of an A2 receptor-specific agonist, 5-N-methylcarboxamidoadenosine (MECA), at the doses of 1 nM to 1 µM had no significant effect on LH or FSH secretion, suggesting the absence of this receptor subtype in the gonadotrope. However, a sharp inhibition of the basal secretion of these gonadotropins was observed after the administration of 10 µM MECA. This effect mimicked the inhibition induced by R-PIA, supporting the hypothesis of the presence of A1 receptors in the gonadotrope. R-PIA (1 nM to 1 µM) also inhibited the secretion of LH and FSH induced by phospholipase C (0.5 IU/ml) in a dose-dependent manner. These results suggest the presence of A1 receptors and the absence of A2 receptors in the gonadotrope. It is possible that the inhibition of LH and FSH secretion resulting from the activation of A1 receptors may have occurred independently of the increase in membrane phosphoinositide synthesis

Influence of adenosine agonists and antiepileptic drugs on theophylline-induced seizures in rats.

Seizures is a major toxicity of theophylline. The mechanism of theophylline-induced seizures is not known, but antagonism at adenosine receptors may be a possibility. The effect of pretreatment with different doses of adenosine (100, 500 and 1000 mg/kg, i.p.), and the adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA), 1, 5 and 10 mg/kg, i.p., was studied against seizures induced by theophylline in rats. Both these drugs, at all dose levels tested, failed to protect theophylline seizures. Thus adenosinergic system is unlikely to be involved in mediating the convulsant action of theophylline. On the other hand, the conventional antiepileptic drugs, i.e. diazepam (4 mg/kg), sodium valproate (300 mg/kg) and phenobarbitone (50 mg/kg), but not carbamazepine, afforded some protection. The modification of course of seizures, by the antiepileptic drugs suggests the involvement of some other alternate mechanism in theophylline-induced seizures.

Adenosinergic system as an endogenous anticonvulsant mechanism.

The treatment of epilepsies remains far from adequate primarily due to inadequate understanding of the pathophysiology of seizures. The conventional approach for research into epilepsy has been study of factors responsible for initiation of seizures. However, now attention is being drawn to the spontaneous and abrupt arrest of seizures which suggests a distinct possibility of activation of an endogenous anticonvulsant mechanism(s), which may be targeted in future for controlling seizures. Of the various endogenous anticonvulsant mechanisms, the concept of an endogenous anticonvulsant substance has gained much experimental support and, many potential candidates have been postulated. Of these adenosinergic system appears to be the most promising. This review discusses the possible role of adenosinergic system in seizures, in relation to the available antiepileptic drugs and its therapeutic implications.

Unusual discrimination against carrier protein antibodies during partial purification of hapten-protein polyclonal antibodies to plant stress hormones.

Polyclonal antibodies (PcAb) were raised against t-zeatin riboside (t-ZR) and abscisic acid (ABA). t-ZR-BSA and ABA-BSA antibodies had high titre and specificity to haptens but also contained BSA specific antibodies as observed in double immuno diffusion and quantitative precipitation tests. Partial purification of antiserum by precipitation, desalting, and ion-exchange chromatography almost completely eliminated interference from BSA specific antibodies. Consequently, very little or no reaction was observed in dot-immunoblot assays even when high concentrations of BSA were probed with partially purified t-ZR-BSA IgG. Further studies with ABA antiserum showed that discrimination against BSA occurred during chromatography and not during salt fractionation. Because antibodies to both hapten and carrier protein were predominantly of IgG class, this unusual discrimination against carrier protein Ab was possibly influenced by two approaches followed for DEAE chromatography, viz. (i) adsorption of IgG at pH 8 followed by elution; or (ii) adsorption of contaminating proteins at neutral pH while specific IgG comes off as unbound fraction.