The preventive effect of exogenous adenosine triphosphate on methanol-induced cardiotoxicity in rats

Abstract Exposure to methanol can cause serious consequences such as permanent visual disturbances and death. The heart tissue is highly vulnerable to ATP deficiency. Our study aimed to investigate whether exogenous ATP administration may alleviate methanol-induced ATP deficiency and subsequent oxidative damage in rat heart tissue. A total of 30 rats were divided into equal five groups; Healthy Group (HG), Methotrexate (MXG), Methanol (MeOH), Methotrexate+Methanol (MXM), and Methotrexate+Methanol+ATP (MMA) groups. We inhibited tetrahydrofolate synthesis by methotrexate to induce methanol toxicity. Methotrexate was administered to MXG, MXM, and MMA group animals for seven days with a catheter directly to the stomach at a 0,3 mg/kg dose per day. At the end of this period, % 20 methanol at a dose of 3 g/kg was administered to MeOH, MMA and MXM group animals. Immediately after methanol application, MMA group animals were injected with ATP at a 4 mg/kg dose intraperitoneally. Blood samples and heart tissues were used for biochemical analysis and histopathological examination. Co-exposure to methanol and methotrexate substantially exacerbated cardiac damage, indicating the potent cardiotoxic effects of methanol. However, the administration of exogenous ATP to MMA group animals brought biochemical oxidative damage parameters and histopathological findings closer to HG.

Antihypoxic and anti-ischemic properties of the North Caucasus flora plant extracts / Propiedades antihipóxicas y antiisquémicas de los extractos de plantas de la flora del norte del Cáucaso

Nowdays it is established that ischemic brain damage like ischemic stroke is one of the leading cause of death and disability in the population that assumes relevance development of anti-ischemic drugs. The work studied the anti-hypoxic and anti-ischemic effect of 7 plant extracts. Antihypoxic activity was assessed on models of hypobaric, hypercapnic, histotoxic, hematotoxic hypoxia. Anti-ischemic activity of test-extracts was studied on the focal cerebral ischemia model. Administration of Tagetes patula, Gaillardia pulchella, Sorbaria sorbifolia, Grossularia reclinata, Ribes nigrum, Rubus caesius and Lysimachia punctata extracts contributed to the necrosis zone reduction by 56.6% (p<0.05); 37.3% (p<0.05); 73.2% (p<0.05); 49.4% (p<0.05); 42.5% (p<0.05); 85.5% (p<0.05); 44.2% (p<0.05) and also restored aerobic metabolism in brain tissue. Test - objects increased of the animal lifespan under hypoxia conditions. Based on the data obtained, it is assumed that further studies of North Caucasus flora plant extracts as cerebro-protective agents are promising.

Hoy en día, se ha establecido que el daño cerebral isquémico, como el accidente cerebrovascular isquémico, es una de las principales causas de muerte y discapacidad en la población lo cual hace relevante el desarrollo fármacos antiisquémicos. En este trabajo se estudió el efecto antihipóxico y antiisquémico de siete extractos de plantas. La actividad antihipóxica se evaluó en modelos de hipoxia hipocrática, hipercápnica, histotóxica y hematotóxica. La actividad antiisquémica de los extractos de prueba se estudió en el modelo de isquemia cerebral focal. La administración de los extractos de Tagetes patula; Gaillardia pulchella; Sorbaria sorbifolia; Grossularia reclinata; Ribes nigrum; Rubus caesius y Lysimachia punctata contribuyeron a la reducción de la zona de necrosis en un 56,6% (p<0,05); 37,3% (p<0,05); 73,2% (p<0,05); 49,4% (p<0,05); 42,5% (p<0,05); 85,5% (p<0,05); 44.2% (p<0.05), respectivamente, además, de restaurar el metabolismo aeróbico en el tejido cerebral. Comparado con el control, se observó un aumento en el tiempo de sobrevida del animal en condiciones de hipoxia. Sobre la base de los interesantes datos obtenidos, se sugiere estudios adicionales de extractos de plantas de la flora del Cáucaso Norte como agentes protectores del cerebro.

Importancia del proceso de limpieza y desinfección de superficies críticas en un servicio dental: impacto de un programa de intervención / Importance of cleaning and disinfection of critical surfaces in dental health services: impact of an intervention program

Resumen Introducción La atención odontológica se ha transformado en un desafío para los programas de prevención y control de infecciones asociadas a la atención de salud (IAAS), dado que el ambiente, entre otros factores, juega un rol importante en la cadena de transmisión. Método Se realizó un programa de intervención en el Servicio de Dental del Hospital Militar de Santiago, entre los años 2014-2015, que contempló tres etapas: etapa diagnóstica, de intervención y de evaluación. Objetivo Mejorar la seguridad de las superficies críticas involucradas en la atención dental. Resultados Durante la etapa diagnóstica se constató que el proceso de limpieza y desinfección era deficiente. La superficie crítica más contaminada fue la unidad porta-instrumental, luego el área limpia y la manilla de la lámpara. Las superficies que redujeron significativamente su contaminación, posterior a la intervención, fueron el área limpia y la unidad porta-instrumental. Conclusiones La capacitación en relación a los procesos de limpieza y desinfección de superficies y del equipamiento dental es una de las estrategias costo-eficientes en la prevención de las IAAS, sencilla y fácil de aplicar.

Introduction Dental care has become a challenge for healthcare associated infection prevention programs, since the environment, within other factors, plays an important role in the transmission chain. Materials and Methods An intervention program was designed for the Dental Unit of Hospital Militar de Santiago, between years 2014 and 2015. The program contemplated 3 stages: diagnostic, intervention and evaluation stage. Objective To improve the safety of critical surfaces involved in dental healthcare. Results During the diagnostic stage, the cleaning and disinfection process was found to be deficient. The most contaminated critical surface was the instrument holder unit, then the clean area and lamp handle. The surfaces that significantly reduced their contamination, after the intervention, were the clean area and the instrument carrier unit. Conclusion Training in the processes of cleaning and disinfecting surfaces and dental equipment is one of the cost-effective strategies in preventing healthcare-associated infections (HCAI), with simple and easy-to-apply methods.

Autophagy protects against neural cell death induced by piperidine alkaloids present in Prosopis juliflora (Mesquite)

ABSTRACT Prosopis juliflora is a shrub that has been used to feed animals and humans. However, a synergistic action of piperidine alkaloids has been suggested to be responsible for neurotoxic damage observed in animals. We investigated the involvement of programmed cell death (PCD) and autophagy on the mechanism of cell death induced by a total extract (TAE) of alkaloids and fraction (F32) from P. juliflora leaves composed majoritary of juliprosopine in a model of neuron/glial cell co-culture. We saw that TAE (30 µg/mL) and F32 (7.5 µg/mL) induced reduction in ATP levels and changes in mitochondrial membrane potential at 12 h exposure. Moreover, TAE and F32 induced caspase-9 activation, nuclear condensation and neuronal death at 16 h exposure. After 4 h, they induced autophagy characterized by decreases of P62 protein level, increase of LC3II expression and increase in number of GFP-LC3 cells. Interestingly, we demonstrated that inhibition of autophagy by bafilomycin and vinblastine increased the cell death induced by TAE and autophagy induced by serum deprivation and rapamycin reduced cell death induced by F32 at 24 h. These results indicate that the mechanism neural cell death induced by these alkaloids involves PCD via caspase-9 activation and autophagy, which seems to be an important protective mechanism.

Analysis of the presence of organic matter (ATP) in mobile devices of healthcare workers in hospitals

We report the result of an awareness campaign about the importance of hand hygiene after using different devices used in assistance to patients, such as tablets, notebooks, mobile phones, identification cards, watches, cameras, showing the level of contamination found after detection of adenosine triphosphate (ATP) via bioluminescence, which enables a quantitative assessment ready and easy to implement. ATP molecules found in all living cells react with the enzyme complex to generate light and represent the presence of organic matter in such objects(AU)

Extracellular adenosine 5'-triphosphate concentrations changes in rat spinal cord associated with the activation of urinary bladder afferents. A microdialysis study. / Variação da concentração extracelular de 5'-trifosfato de adenosina na medula espinal de rata associadas a fibras aferentes vesicais. Um estudo com microdiálise

ABSTRACT Objective To determine adenosine 5’-triphosphate levels in the interstice of spinal cord L6-S1 segment, under basal conditions or during mechanical and chemical activation of urinary bladder afferents. Methods A microdialysis probe was transversally implanted in the dorsal half of spinal cord L6-S1 segment in female rats. Microdialysate was collected at 15 minutes intervals during 135 minutes, in anesthetized animals. Adenosine 5’-triphosphate concentrations were determined with a bioluminescent assay. In one group of animals (n=7) microdialysate samples were obtained with an empty bladder during a 10-minutes bladder distension to 20 or 40cmH2O with either saline, saline with acetic acid or saline with capsaicin. In another group of animals (n=6) bladder distention was performed and the microdialysis solution contained the ectonucleotidase inhibitor ARL 67156. Results Basal extracellular adenosine triphosphate levels were 110.9±35.34fmol/15 minutes, (mean±SEM, n=13), and bladder distention was associated with a significant increase in adenosine 5’-triphosphate levels which was not observed after bladder distention with saline solution containing capsaicin (10µM). Microdialysis with solution containing ARL 67156 (1mM) was associated with significantly higher extracellular adenosine 5’-triphosphate levels and no further increase in adenosine 5’-triphosphate was observed during bladder distension. Conclusion Adenosine 5’-triphosphate was present in the interstice of L6-S1 spinal cord segments, was degraded by ectonucleotidase, and its concentration increased following the activation of bladder mechanosensitive but not of the chemosensitive afferents fibers. Adenosine 5’-triphosphate may originate either from the central endings of bladder mechanosensitive primary afferent neurons, or most likely from intrinsic spinal neurons, or glial cells and its release appears to be modulated by capsaicin activated bladder primary afferent or by adenosine 5’-triphosphate itself.

RESUMO Objetivo Determinar as concentrações extracelulares do 5’-trifosfato de adenosina no interstício dos segmentos medulares L6-S1, em condições basais ou durante a ativação mecânica e química das fibras aferentes vesicais. Métodos Um cateter de microdiálise foi implantado no sentido transversal na parte dorsal da medula espinal, entre os segmentos L6-S1 de ratas. O microdialisado foi coletado em intervalos de 15 minutos, durante 135 minutos, com os animais anestesiados. A concentração de 5’-trifosfato de adenosina nas amostras foi determinada mediante ensaio de bioluminescência. Em um grupo de animais (n=7), as amostras de microdialisado foram obtidas com a bexiga vazia, com distensão da bexiga para volume de 20 ou 40cmH2O, com solução salina, solução salina com ácido acético, ou solução salina com capsaicina. Em outro grupo (n=6), foi realizada com a bexiga distendida, e a solução para microdiálise continha o inibidor de ectonucleotidase ARL 67156. Resultados Os níveis extracelulares de trifosfato de adenosina no início do estudo foram 110,9±35,36fmol/15 minutos (média±EPM, n=13), e a distensão da bexiga causou um aumento nos níveis de 5’-trifosfato de adenosina, o que não foi observado após a distensão da bexiga com solução salina contendo capsaicina (10µM). A microdiálise com solução contendo ARL 67156 (1mM) foi associada com significante aumento dos níveis de trifosfato de adenosina extracelular, e nenhum aumento do trifosfato de adenosina foi observado durante a distensão da bexiga. Conclusão O 5’-trifosfato de adenosina está presente no interstício do segmento L6-S1 da medula espinal, é degradado por ectonucleotidases, e sua concentração aumentou com a ativação das fibras aferentes mecanossensíveis da bexiga, mas não das quimiossensíveis. O 5’-trifosfato de adenosina pode ter sido liberado das terminações centrais dos neurônios aferentes primários mecanossensíveis ou, mais provavelmente, de neurônios espinais intrínsecos, ou ainda de células gliais. Sua liberação parece ser modulada por fibras aferentes primárias da bexiga ativadas pela capsaicina ou pelo próprio 5’-trifosfato de adenosina.

Assessment of disinfection of hospital surfaces using different monitoring methods / Avaliação da desinfecção de superfícies hospitalares por diferentes métodos de monitoramento / Evaluación de la desinfección de superficies hospitalarias por diferentes métodos de monitorización

to assess the efficiency of cleaning/disinfection of surfaces of an Intensive Care Unit.

avaliar a eficiência da limpeza/desinfecção de superfícies de uma Unidade de Terapia Intensiva.

evaluar la eficiencia de la limpieza/desinfección de superficies de una Unidad de Terapia Intensiva.

Effects of eugenol on resting tension of rat atria

In cardiac and skeletal muscle, eugenol (μM range) blocks excitation-contraction coupling. In skeletal muscle, however, larger doses of eugenol (mM range) induce calcium release from the sarcoplasmic reticulum. The effects of eugenol are therefore dependent on its concentration. In this study, we evaluated the effects of eugenol on the contractility of isolated, quiescent atrial trabeculae from male Wistar rats (250-300 g; n=131) and measured atrial ATP content. Eugenol (1, 3, 5, 7, and 10 mM) increased resting tension in a dose-dependent manner. Ryanodine [100 µM; a specific ryanodine receptor (RyR) blocker] and procaine (30 mM; a nonspecific RyR blocker) did not block the increased resting tension induced by eugenol regardless of whether extracellular calcium was present. The myosin-specific inhibitor 2,3-butanedione monoxime (BDM), however, reversed the increase in resting tension induced by eugenol. In Triton-skinned atrial trabeculae, in which all membranes were solubilized, eugenol did not change resting tension, maximum force produced, or the force vs pCa relationship (pCa=-log [Ca2+]). Given that eugenol reduced ATP concentration, the increase in resting tension observed in this study may have resulted from cooperative activation of cardiac thin filaments by strongly attached cross-bridges (rigor state).

Development of cardioplegic solution without potassium: experimental study in rat / Desenvolvimento de solução cardioplégica sem potássio: estudo experimental em ratos

INTRODUCTION: Myocardial preservation during open heart surgeries and harvesting for transplant are of great importance. The heart at the end of procedure has to resume its functions as soon as possible. All cardioplegic solutions are based on potassium for induction of cardioplegic arrest. OBJECTIVE: To assess a cardioplegic solution with no potassium addition to the formula with two other commercially available cardioplegic solutions. The comparative assessment was based on cytotoxicity, adenosine triphosphate myocardial preservation, and caspase 3 activity. The tested solution (LIRM) uses low doses of sodium channel blocker (lidocaine), potassium channel opener (cromakalin), and actin/myosin cross bridge inhibitor (2,3-butanedione monoxime). METHODS: Wistar rats underwent thoracotomy under mechanical ventilation and three different solutions were used for "in situ" perfusion for cardioplegic arrest induction: Custodiol (HTK), Braile (G/A), and LIRM solutions. After cardiac arrest, the hearts were excised and kept in cold storage for 4 hours. After this period, the hearts were assessed with optical light microscopy, myocardial ATP content and caspase 3 activity. All three solutions were evaluated for direct cytotoxicity with L929 and WEHI-164 cells. RESULTS: The ATP content was higher in the Custodiol group compared to two other solutions (P<0.05). The caspase activity was lower in the HTK group compared to LIRM and G/A solutions (P<0.01). The LIRM solution showed lower caspase activity compared to Braile solution (P<0.01). All solutions showed no cytotoxicity effect after 24 hours of cells exposure to cardioplegic solutions. CONCLUSION: Cardioplegia solutions without potassium are promised and aminoacid addition might be an interesting strategy. More evaluation is necessary for an optimal cardioplegic solution development.

INTRODUÇÃO: Preservação do miocárdio durante cirurgias cardíacas abertas e de colheita para transplante são de grande importância. O coração ao final do processo tem de retomar as suas funções, logo que possível. Todas as soluções cardioplégicas são baseadas em potássio, para indução de parada cardioplégica. OBJETIVO: Comparar a uma solução cardioplégica sem adição de potássio à sua fórmula com duas outras soluções cardioplégicas disponíveis comercialmente. A avaliação comparativa foi baseada na citotoxicidade, preservação miocárdica (adenosina trifosfato, ATP) e atividade da caspase 3. A solução testada (LIRM) utiliza baixas doses de bloqueador de canal de sódio (lidocaína), abridor do canal de potássio (cromacalina) e inibidor da ponte actina/miosina (2,3-butanodiona monoxima). MÉTODOS: Ratos Wistar foram submetidos à toracotomia sob ventilação mecânica e três soluções diferentes foram utilizadas para perfusão in situ para a indução de parada cardioplégica: soluções Custodiol (HTK) Braile (G/A) e LIRM. Após parada cardíaca, os corações foram retirados e mantidos em câmara fria por 4 horas. Após esse período, o coração foi avaliado com microscopia de luz ótica, o conteúdo de ATP miocárdico e atividade da caspase 3. Todas as três soluções foram avaliadas quanto à citotoxicidade direta com células L929 e WEHI-164. RESULTADOS: A quantidade de ATP foi maior no grupo Custodiol em comparação às com outras duas soluções (P<0,05). A atividade de caspase foi menor no grupo HTK quando comparado às soluções LIRM e G/A (P<0,01). A solução LIRM demonstrou menor atividade da caspase em comparação à solução Braile (P<0,01). Todas as soluções não mostraram qualquer efeito de citotoxicidade após 24 horas de exposição das células às soluções cardioplégicas. CONCLUSÃO: Soluções cardioplégicas sem potássio são uma perspectiva e a adição de aminoácido pode ser uma estratégia interessante. Mais avaliações são necessárias para o desenvolvimento ideal da solução cardioplégica.

Quantitative in Vivo Detection of Brain Cell Death after Hypoxia Ischemia Using the Lipid Peak at 1.3 ppm of Proton Magnetic Resonance Spectroscopy in Neonatal Rats

This study was performed to determine the accuracy of proton magnetic spectroscopy (1H-MRS) lipid peak as a noninvasive tool for quantitative in vivo detection of brain cell death. Seven day-old Sprague Dawley rats were subjected to 8% oxygen following a unilateral carotid artery ligation. For treatment, cycloheximide was given immediately after hypoxic ischemia (HI). Lipid peak was measured using 1H-MRS at 24 hr after HI, and then brains were harvested for fluorocytometric analyses with annexin V/propidium iodide (PI) and fluorescent probe JC-1, and for adenosine-5'-triphosphate (ATP) and lactate. Increased lipid peak at 1.3 ppm measured with 1H-MRS, apoptotic and necrotic cells, and loss of mitochondrial membrane potential (DeltaPsi) at 24 hr after HI were significantly improved with cycloheximide treatment. Significantly reduced brain ATP and increased lactate levels observed at 24 hr after HI showed a tendency to improve without statistical significance with cycloheximide treatment. Lipid peak at 1.3 ppm showed significant positive correlation with both apoptotic and necrotic cells and loss of DeltaPsi, and negative correlation with normal live cells. Lipid peak at 1.3 ppm measured by 1H-MRS might be a sensitive and reliable diagnostic tool for quantitative in vivo detection of brain cell death after HI.

Individualized Tumor Response Testing for Prediction of Response to Paclitaxel and Cisplatin Chemotherapy in Patients with Advanced Gastric Cancer

The purpose of our study was to determine the most accurate analytic method to define in vitro chemosensitivity, using clinical response as reference standard in prospective clinical trial, and to assess accuracy of adenosine triphosphate-based chemotherapy response assay (ATP-CRA). Forty-eight patients with chemo-naive, histologically confirmed, locally advanced or metastatic gastric cancer were enrolled for the study and were treated with combination chemotherapy of paclitaxel 175 mg/m2 and cisplatin 75 mg/m2 for maximum of six cycles after obtaining specimen for ATP-CRA. We performed the receiver operator characteristic curve analysis using patient responses by WHO criteria and ATP-CRA results to define the method with the highest accuracy. Median progression free survival was 4.2 months (95% confidence interval [CI]: 3.4-5.0) and median overall survival was 11.8 months (95% CI: 9.7-13.8) for all enrolled patients. Chemosensitivity index method yielded highest accuracy of 77.8% by ROC curve analysis, and the specificity, sensitivity, positive and negative predictive values were 95.7%, 46.2%, 85.7%, and 75.9%. In vitro chemosensitive group showed higher response rate (85.7% vs. 24.1%) (P=0.005) compared to chemoresistant group. ATP-CRA could predict clinical response to paclitaxel and cisplatin chemotherapy with high accuracy in advanced gastric cancer patients. Our study supports the use of ATP-CRA in further validation studies.

Biochemical evaluation of focal non-reperfusion cerebral ischemia by middle cerebral artery occlusion in rats / Avaliação bioquímica da isquemia cerebral focal, não associada à reperfusão, por oclusão da artéria cerebral média em ratos

Cerebral ischemia is an important event in clinical and surgical neurological practice since it is one of the diseases that most compromise the human species. In the present study 40 adult rats were submitted to periods of focal ischemia of 30, 60 and 90 min without reperfusion and animals submitted to a sham procedure were used as controls. We analyzed the levels of ATP, malondialdehyde and caspase-3. No significant differences in the biochemical measurements were observed between the right and left brain hemispheres of the same animal in each experimental group. Reduced ATP levels were observed after the three periods of ischemia compared to the sham group. No significant increase in malondialdehyde or caspase-3 levels was observed. Despite significant changes in ATP levels, the results indicated cell viability in the ischemic region as shown by the low rates of lipid peroxidation and apoptosis, findings probably related to the lack of reperfusion.

Isquemia cerebral é um acontecimento importante na prática neurológica clínica e cirúrgica, uma vez que é uma das doenças que mais comprometem a espécie humana. No presente estudo 40 ratos adultos foram submetidos a períodos de isquemia focal de 30, 60 e 90 min e como controle foram utilizados animais do grupo sham. Foram analisados os níveis de ATP, malondialdeído e caspase-3. Nenhuma diferença significativa nas dosagens bioquímicas foram observadas entre os hemisférios cerebrais direito e esquerdo do mesmo animal em cada grupo experimental. Foi observada redução nos níveis de ATP após os três períodos de isquemia, em comparação com o grupo sham. Nenhum aumento significativo dos níveis de malondialdeído ou caspase-3 foi observado. Apesar das alterações significativas nos níveis ATP, os resultados indicaram viabilidade celular na região isquêmica como demonstrado pela baixa taxa de peroxidação lipídica e apoptose, achados que provavelmente estão relacionados com a falta de reperfusão.

Mapeamento dos domínios antigênicos compartilhados entre a apirase de batata e as isoformas de ATP difosfohidrolase de Schistosoma mansoni / Mapping of the conserved antigenic domains shared between potato apyrase and ATP diphosphohydrolase isoforms from Schistosoma mansoni

Usando a apirase de batata como antígeno, as propriedades imunogênicas das isoformas de ATP difosfohidrolase de S. mansoni foram inicialmente exploradas em esquistossomose experimental. Elevada reatividade de anticorpos IgG2a e IgG1 contra esta proteína vegetal foi observada em soro de camundongos BALB/c na fase aguda da infecção (8-9ª semana pós-infecção). Elevada reatividade de anticorpos IgG1 com a apirase de batata, mas não de IgG2a, foi encontrada na fase crônica da infecção (17ª semana pós-infecção), diferenciando sorologicamente as fases da infecção. Adicionalmente, foi observado que o inóculo de apirase de batata em camundongos BALB/c saudáveis tem marcante atividade estimulatória, aumentando significativamente os níveis de anticorpos IgG1 e IgG2a específicos. O subtipo IgG1 de camundongo, mas não IgG2a, reage com a ATP difosfohidrolase presente na preparação de SEA. A reatividade de anticorpos contra a apirase de batata foi monitorada por um período de 11 meses em camundongos BALB/c tratados com oxaminiquina na fase crônica da doença.

A reatividade de IgM, IgG total ou IgG1 contra a apirase de batata reduziu significativamente (~60%) após 11 meses, enquanto IgG2a, que esteve elevada na fase aguda, perde a significância na fase crônica e permanece inalterada na etapa do pós tratamento. Após a quimioterapia, os camundongos foram re-infectados com 100 cercárias, e nenhuma diferença significativa foi observada na soropositividade de IgG1, mas uma elevação significativa de IgG2a foi detectada nos camundongos re-infectados sugerindo uma nova fase aguda e sua participação nos mecanismos de proteção contra o Schistosoma. Estudos in silico demonstraram uma íntima relação estrutural e evolucionária entre a apirase de batata e as isoformas de ATP difosfohidrolases de S. mansoni. A predição de modelos tridimensionais sugeriu que os domínios conservados podem estar expostos e disponíveis para a ligação com anticorpos. O perfil de reatividade de anticorpos contra a apirase de batata foi, então, estudado em amostras de soros obtidas de pacientes com esquistossomose, moradores de três áreas endêmicas diferentes. Amostras de soros de grupos de adultos e crianças mostraram alta reatividade contra a apirase de batata, com elevação dos níveis de anticorpos IgA, IgE, IgG1 ou IgG4, com diferenças significativas entre eles. Após a quimioterapia, redução significativa ou ausência de reatividade de anticorpos contra a apirase de batata foi observada nestes pacientes. Esses achados podem estar associados à resistência ou susceptibilidade

Mapeamento dos domínios antigênicos compartilhados entre a apirase de batata e as isoformas de ATP difosfohidrolase de Schistosoma mansoni

Usando a apirase de batata como antígeno, as propriedades imunogênicas das isoformas de ATP difosfohidrolase de S. mansoni foram inicialmente exploradas em esquistossomose experimental. Elevada reatividade de anticorpos IgG2a e IgG1 contra esta proteína vegetal foi observada em soro de camundongos BALB/c na fase aguda da infecção (8-9ª semana pós-infecção). Elevada reatividade de anticorpos IgG1 com a apirase de batata, mas não de IgG2a, foi encontrada na fase crônica da infecção (17ª semana pós-infecção), diferenciando sorologicamente as fases da infecção. Adicionalmente, foi observado que o inóculo de apirase de batata em camundongos BALB/c saudáveis tem marcante atividade estimulatória, aumentando significativamente os níveis de anticorpos IgG1 e IgG2a específicos. O subtipo IgG1 de camundongo, mas não IgG2a, reage com a ATP difosfohidrolase presente na preparação de SEA. A reatividade de anticorpos contra a apirase de batata foi monitorada por um período de 11 meses em camundongos BALB/c tratados com oxaminiquina na fase crônica da doença.

A reatividade de IgM, IgG total ou IgG1 contra a apirase de batata reduziu significativamente (~60%) após 11 meses, enquanto IgG2a, que esteve elevada na fase aguda, perde a significância na fase crônica e permanece inalterada na etapa do pós tratamento. Após a quimioterapia, os camundongos foram re-infectados com 100 cercárias, e nenhuma diferença significativa foi observada na soropositividade de IgG1, mas uma elevação significativa de IgG2a foi detectada nos camundongos re-infectados sugerindo uma nova fase aguda e sua participação nos mecanismos de proteção contra o Schistosoma. Estudos in silico demonstraram uma íntima relação estrutural e evolucionária entre a apirase de batata e as isoformas de ATP difosfohidrolases de S. mansoni. A predição de modelos tridimensionais sugeriu que os domínios conservados podem estar expostos e disponíveis para a ligação com anticorpos. O perfil de reatividade de anticorpos contra a apirase de batata foi, então, estudado em amostras de soros obtidas de pacientes com esquistossomose, moradores de três áreas endêmicas diferentes. Amostras de soros de grupos de adultos e crianças mostraram alta reatividade contra a apirase de batata, com elevação dos níveis de anticorpos IgA, IgE, IgG1 ou IgG4, com diferenças significativas entre eles. Após a quimioterapia, redução significativa ou ausência de reatividade de anticorpos contra a apirase de batata foi observada nestes pacientes. Esses achados podem estar associados à resistência ou susceptibilidade

The involvement of purinergic receptors in the kidney physiological and pathophysiological implications / O envolvimento de receptores purinérgicos no rim implicações fisiológicas e fisiopatológicas

The studies on the purinergic system in the kidney clearly showed its role on the renal hemodynamics, glomerular filtration and tubular function. The effectsof purinergic agonists on the mechanisms of tubuloglomerular feedback, and tubular transport of water and solutes, are well defined. In addition, severalstudies have documented the role of adenosine and specific ATP receptors on the processes of renal diseases, with special interest on the ischemiareperfusioninjury, renal cystic disease, glomerular and tubulointerstitial diseases. Therefore, the purinergic system has become a growing field for researchin renal physiology and pathophysiology, leading to therapeutic possibilities of using specific agonists and antagonists.

Os estudos sobre o sistema purinérgico no rim evidenciaram ao longo dos anos a sua participação na hemodinâmica renal, filtração glomerular e funçãotubular. É bem conhecida a participação de efetores purinérgicos no mecanismo de feedback túbulo-glomerular e transporte tubular de água e solutos.Além disso, vários trabalhos têm mostrado a participação da adenosina e de receptores específicos de ATP em processos de doença renal, com umespecial interesse na lesão da isquemia-reperfusão, doença cística renal, doenças glomerulares e túbulo-intersticiais. Portanto, o sistema purinérgico temse tornado alvo crescente de pesquisa em fisiologia e fisiopatologia renal, voltando-se para as possibilidades terapêuticas no uso de agentes agonistas eantagonistas específicos.

Level of oxidative stress in the red blood cells of patients with liver cirrhosis.

BACKGROUND & OBJECTIVE: Liver cirrhosis is associated with gastrointestinal haemorrhage and oesophageal variceal bleeding. Altered platelet functions has been reported to be a cause of bleeding complication. We carried out this study to find out the level of oxidative stress in the red blood cells of patients with liver cirrhosis. METHODS: Fifty patients admitted with the complication of liver cirrhosis (with bleeding complications, n=30 and without bleeding complications, n=20) were included in the study. Age and sex matched normal healthy volunteers (n=45) served as controls. The levels of oxyhaemoglobin and methaemoglobin were assayed in the red blood cells. Oxidative stress markers such as lipid peroxides, lipid hydroperoxides and nitric oxide were determined along with enzymatic antioxidants. Membrane bound adenosine triphosphatases, cytosolic glucose-6-phosphate dehydrogenase and NADHmethaemoglobin reductase were also measured. The levels of cholesterol and total phospholipids were assessed in red blood cell membrane. The osmotic fragility of red blood cells was monitored using different concentrations of sodium chloride. RESULTS: The level of methaemoglobin was significantly higher (P < 0.001) in the red blood cells of liver cirrhotic patients with bleeding complication compared to that of non bleeding patients. The activity level of NADH-methaemoglobin reductase was significantly lower (P<0.001) compared to that of normal subjects. Levels of oxidative stress markers including nitric oxide were found to be higher in patients. The levels of enzymatic antioxidants were low except of glutathione peroxidase. The activity levels of adenosine triphosphatases were also found to be significantly lower (P<0.001) in patients compared to normal subjects. A significant alteration (P<0.05) was found in membrane cholesterol/phospholipid ratio of cirrhotic bleeders. Osmotic fragility of red blood cells was also altered in patients. INTERPRETATION & CONCLUSION: In cirrhotic condition red blood cells are subjected to severe oxidative stress with significant alterations in the membrane properties.

Efecto de sedimentos naturales enriquecidos con zinc, en modelos aislados y en microcosmos, sobre tres especies de invertebrados bentónicos / Effect of zinc-enriched sediments, in open and isolated systems, on three species of benthonic invertebrates

Availability of toxics in aquatic bodies is limited by the physicochemical characteristics of sediments and water, as well as by the interactions between the different xenobiotics and inhabits species. The aim of this work was to relate the effect produced by zinc (Zn) spiked in sediments of the Ignacio Ramirez dam (PIR), in isolated and microcosms models, on ATP concentration of three benthic organisms with the metal biodisponibility. The selected species were a crustacean, an annelid and a mollusk: Hyalella azteca (Amphipoda: Hyalellidae), Limnodrilus hoffmeisteri (Oligochaeta: Tubificidae) and Stagnicola attenuata (Basommatophora: Lymnaeidae), species that are found at high proportions in the reservoir and use different spaces in the benthos. Samples of sediments and organisms were collected from the PIR during the dry season (February of 1999). Metal concentration (Zn, Fe, Cu and Ni), pH, texture, particle size, total nitrogen and organic matter were determined in sediments. Sublethal studies were carried out using two types of static systems (organisms isolated and in microcosms). Both models contained PIR sediments enriched with Zn (nominal concentration of 0.8129 mg/kg) and synthetic water in a proportion of 1:4. The test organisms were added to the systems once the equilibrium was reached (2 hr) considering the biomass quantity with respect to volume (1.0 g of organism by each 100 ml of water:sediment). After 0, 12, 24, 36, 48 and 72 hr of exposure, samples of sediment and hydrobionts were taken, and Zn content was quantified by atomic absorption. ATP concentration was also determined in organisms. The effect produced by natural sediments spiked with Zn is increased by the presence of more than one specie in the system (microcosm). With respect to Zn levels, two of the organisms tend to lose this metal in isolated and microcosm models, probably as a regulation strategy in its accumulation, as well as Fe presence in the reservoir sediments. Therefore...

En los cuerpos acuáticos la disponibilidad de los tóxicos es limitada por las características fisicoquímicas de los sedimentos y agua, así como por las interacciones entre los diversos xenobióticos y entre las especies que los habitan. Por lo anterior, el objetivo del presente trabajo fue relacionar el efecto producido por el zinc (Zn) sembrado en sedimentos del embalse Ignacio Ramírez (PIR), en modelos aislados y en microcosmos, sobre el ATP de res organismos bentónicos con la biodisponibilidad del metal. Las especies seleccionadas fueron: Hyalella azteca, Limnodrilus hoffmeisteri y Stagnicola attenuata, dado que se encuentran en altas proporciones en el embalse y ocupan espacios diferentes en el bentos. Las muestras de sedimentos y organismos se colectaron en la estación de sequía (febrero de 1999). A los primeros se les determinó el pH, textura, tamaño de partícula, nitrógeno total, materia orgánica y concentración de metales (Zn, Fe, Cu y Ni). Posteriormente se realizó un estudio de toxicidad subletal utilizando dos tipos de sistemas estáticos (organismos aislados y en microcosmos). Ambos modelos contenían sedimentos de la PIR enriquecidos con Zn (concentración nominal de 0.8129 mg/kg) y agua sintética en una proporción de 1:4. Los organismos de prueba fueron adicionados una vez alcanzado el equilibrio (2 hr) considerando la cantidad de biomasa con respecto al volumen (1.0 g de organismo por cada 100 ml de agua:sedimento). Después de 0, 12, 24, 36, 48 y 72 hr de exposición se tomaron muestras del sedimento y de los hidrobiontes, a los cuales se les cuantificó el contenido de Zn por absorción atómica. A los organismos también se les determinó la concentración de ATP. Los resultados obtenidos muestran que el efecto producido por los sedimentos naturales enriquecidos se ve potenciado por la presencia de más de una especie en el sistema (microcosmos). Con respecto a los niveles de Zn, dosde los organismos (L. hoffmeisteri y S. attenuata) tienden a...

Pesquisa de síndrome metabólico e insulinoresistencia: en una población de trabajadores de salud del Hospital Patrocinio Peñuela Ruíz de IVSS: en San Cristóbal Estado Táchira 2004 / Investigation of metabolic syndrome and insulin-resistance: in a population of workers of the health of the Hospital Patrocinio Peñuela Ruíz of IVSS: in San Cristóbal Táchira State 2004

El síndrome metabólico es una entidad patológica en el que coexisten en un mismo individuo distintos problemas, que incrementan el riesgo cardiovascular en ellos. Se diseño un estudio prospectivo que incluyó 100 trabajadores de salud a quienes se les realizó un formulario que incluyó antecedentes, medidas antropométricas y análisis de laboratorio. Tomando en cuenta criterios de ATP III, se encontró un 30 por ciento de pacientes con síndrome metabólico, con un 23,3 por ciento en el sexo masculino. 75 por ciento de pacientes con riesgo cardiovascular latente a los 10 años. Así mismo, se evaluó insulinoresistencia, encontrándose un 34 por ciento con esta entidad. Con esto se intenta resaltar la importancia de identificar y tratar oportunamente factores de riesgo como estrategia en la prevención de enfemedades cardiovasculares.

Extracellular ATP is generated by ATP synthase complex in adipocyte lipid rafts

Mitochondrial biogenesis is known to accompany adipogenesis to complement ATP and acetyl-CoA required for lipogenesis. Here, we demonstrated that mitochondrial proteins such as ATP synthase alpha and beta, and cytochrome c were highly expressed during the 3T3-L1 differentiation into adipocytes. Fully-differentiated adipocytes showed a significant increase of mitochondria under electron microscopy. Analysis by immunofluorescence, cellular fractionation, and surface biotinylation demonstrated the elevated levels of ATP synthase complex found not only in the mitochondria but also on the cell surface (particularly lipid rafts) of adipocytes. High rate of ATP (more than 30 micrometer) synthesis from the added ADP and Pi in the adipocyte media suggests the involvement of the surface ATP synthase complex for the exracellular ATP synthesis. In addition, this ATP synthesis was significantly inhibited in the presence of oligomycin, an ATP synthase inhibitor, and carbonyl cyanide m-chlorophenylhydrazone (CCCP), an ATP synthase uncoupler. Decrease of extracellular ATP synthesis in acidic but not in basic media further indicates that the surface ATP synthase may also be regulated by proton gradient through the plasma membrane.

Bioluminometric assay of ATP in mouse brain: Determinant factors for enhanced test sensitivity.

Firefly luciferase bioluminescence (FLB) is a highly sensitive and specific method for the analysis of adenosine-5-triphosphate (ATP) in biological samples. Earlier attempts to modify the FLB test for enhanced sensitivity have been typically based on in vitro cell systems. This study reports an optimized FLB procedure for the analysis of ATP in small tissue samples. The results showed that the sensitivity of the FLB test can be enhanced several fold by using ultraturax homogenizer, perchloric acid extraction, neutralization of acid extract and its optimal dilution, before performing the assay reaction.