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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Some observations on the metabolism and toxicology of sodium nitroprusside

Dawood, Khalid Abdul-Latif January 1982 (has links)
No description available.
2

Pharmacological responses of the human skin microcirculation in health and in diabetes

Morris, Susan Jane January 1997 (has links)
No description available.
3

Impaired endothelium-independent microvascular function in obese young adults

Patik, Jordan Christopher 23 September 2014 (has links)
Microvascular dysfunction is believed to precede the development and contribute to the progression of obesity related diseases such as insulin resistance, hypertension, and coronary artery disease. Multiple studies have found impaired microvascular endothelium-dependent vasodilation occurs prior to the onset of disease in middle aged adults. In order to test the hypothesis that the cutaneous microvasculature of young obese (BMI>30kg/m²), but otherwise healthy, adults would exhibit impaired microvascular response, we recruited 12 obese and 12 lean (BMI<25 kg/m²) individuals. Each group was age-matched and consisted of 5 females and 7 males. Each participant was instrumented with two microdialysis probes inserted in the dermis of the non-dominant forearm for a wide dose range of infusions of either the endothelium-dependent vasodilator methacholine (MCh) or the endothelium-independent vasodilator sodium nitroprusside (SNP). Each microdialysis site was clamped at 33°C with a local heater and affixed with a laser Doppler flux (LDF) probe for determination of local red blood cell flux, an index of blood flow. LDF was recorded continuously while 7 doses of each drug (MCh: 10⁻³-10³mM; SNP: 5x10⁻⁵-50mM) were infused at a rate of 2 [mu]l/min for 8 minutes per dose. Both sites finished with heating to 43°C and infusion of 50mM SNP to confirm site specific maximal vasodilation. Blood pressure was recorded in the last minute of each stage and the corresponding LDF was used to calculate cutaneous vascular conductance (CVC). Dose response curves for CVC at each dose, as well as maximal CVC were analyzed. MCh dose response showed a trend toward endothelium–dependent impairment in obese (p=0.06) and maximal absolute CVC at the MCh site was attenuated in obese versus lean (2.70 ± 0.73 vs 3.30 ± 0.81 LDF/mmHg, p=0.027). Endothelium-independent vasodilation with SNP was impaired at the 4 highest doses of SNP (all P<0.006) and maximal CVC was attenuated in obese compared to lean (2.44 ± 0.74 vs 3.31 ± 0.65 LDF/mmHg, p=0.004). These results support the hypothesis that microvascular function is impaired in young, healthy obese, individuals; however they suggest the impairment is partially endothelium-independent. / text
4

Estudo cross-over controlado por placebo sobre os efeitos do nitroprussiato de sódio nos potenciais evocados P300 e MMN e na sintomatologia de pacientes com esquizofrenia / Double-blind, placebo-controlled trial of the effects of sodium nitroprusside on P300 and MMN auditory evoked potentials in schizophrenia

Almeida, Juliana Silva de 20 October 2017 (has links)
INTRODUÇÃO: A esquizofrenia é um transtorno que se caracteriza pela desorganização de diversos processos mentais, dentre os quais a cognição. Pacientes com esquizofrenia apresentam alterações na amplitude e latência dos potenciais evocados P300 e MMN. A maioria das drogas antipsicóticas atuais têm pouco efeito sobre os sintomas negativos e prejuízos cognitivos dos pacientes, por isso, pesquisadores têm buscado alternativas farmacológicas que possam agir sobre os prejuízos cognitivos e sintomas negativos. Pesquisas recentes demonstraram que o nitroprussiato de sódio (NPS) é capaz de atenuar algumas das manifestações do transtorno que não respondem adequadamente aos tratamentos hoje disponíveis. OBJETIVO: Investigar os efeitos da infusão de NPS sobre a sintomatologia e os potenciais evocados auditivos MMN e P300 em pacientes com esquizofrenia em um ensaio duplo-cego controlado por placebo. MÉTODO: Foram avaliados 12 pacientes com idade entre 25 e 54 anos em tratamento antipsicótico acompanhados no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto. Cada paciente participou de duas sessões experimentais, uma com infusão de NPS e outra com placebo. Escalas psiquiátricas (BPRS e PANSS) foram aplicadas imediatamente antes da infusão de NPS ou soro glicosado, a cada hora durante a infusão e imediatamente após a realização dos exames de P300 e MMN, realizados após o fim da infusão. RESULTADOS: A infusão de NPS foi associada a um aumento significativo da amplitude do potencial evocado MMN e a uma redução nos escores das escalas de sintomas psiquiátricos BPRS e PANSS em comparação com o placebo. CONCLUSÃO: A infusão de NPS foi associada à melhora dos sintomas de esquizofrenia conforme medidos pela BPRS e PANSS e a um aumento da amplitude do potencial evocado MMN. Não houve efeitos da administração do NPS sobre o potencial evocado P300. / INTRODUCTION: Schizophrenia is a mental disorder characterized by disorganization of several mental processes including cognition. Schizophrenia patients present alterations in the amplitude and latency of auditory evoked potentials P300 and MMN. Most current antipsychotics have little or no effect on the negative symptoms or cognitive impairment in schizophrenia, which led researchers to search for pharmacological alternatives that may counteract these manifestations. Recent evidence suggests that sodium nitroprusside (SNP) is able to ameliorate some of the manifestations associated with schizohrenia that do not respond adequately to currently available treatments. OBJECTIVE: To investigate the effects of SNP on schizophrenia symptoms and on the evoked potentials P300 and MMN in a double-blind, placebocontrolled trial. METHODS: The trial involved 12 patients aged 25-54 years in antipsychotic treatment followed up at the Ribeirã Preto Medical School University Hospital. Each patient attended two experimental sessions, one for the infusion of SNP and another for the infusion of placebo. The Brief Psychiatric Rating Scale (BPRS) and the Positive and Negative Syndromes Scale (PANSS) were completed immediately before the infusion, every consecutive hour, and immediately after the P300 and MMN tests, performed after the end of the infusion. RESULTS: The infusion of SNP was associated with a significant increase in the amplitude of MMN and with a reduction in the psychopathology scores of the BPRS and PANSS compared to placebo. CONCLUSION: The administration of SNP was associated with an improvement in schizophrenia symptoms as measured with the BPRS and PANSS and with an increase in the amplitude of the evoked potential MMN. There were no effects of SNP on the evoled potential P300.
5

Estudo cross-over controlado por placebo sobre os efeitos do nitroprussiato de sódio nos potenciais evocados P300 e MMN e na sintomatologia de pacientes com esquizofrenia / Double-blind, placebo-controlled trial of the effects of sodium nitroprusside on P300 and MMN auditory evoked potentials in schizophrenia

Juliana Silva de Almeida 20 October 2017 (has links)
INTRODUÇÃO: A esquizofrenia é um transtorno que se caracteriza pela desorganização de diversos processos mentais, dentre os quais a cognição. Pacientes com esquizofrenia apresentam alterações na amplitude e latência dos potenciais evocados P300 e MMN. A maioria das drogas antipsicóticas atuais têm pouco efeito sobre os sintomas negativos e prejuízos cognitivos dos pacientes, por isso, pesquisadores têm buscado alternativas farmacológicas que possam agir sobre os prejuízos cognitivos e sintomas negativos. Pesquisas recentes demonstraram que o nitroprussiato de sódio (NPS) é capaz de atenuar algumas das manifestações do transtorno que não respondem adequadamente aos tratamentos hoje disponíveis. OBJETIVO: Investigar os efeitos da infusão de NPS sobre a sintomatologia e os potenciais evocados auditivos MMN e P300 em pacientes com esquizofrenia em um ensaio duplo-cego controlado por placebo. MÉTODO: Foram avaliados 12 pacientes com idade entre 25 e 54 anos em tratamento antipsicótico acompanhados no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto. Cada paciente participou de duas sessões experimentais, uma com infusão de NPS e outra com placebo. Escalas psiquiátricas (BPRS e PANSS) foram aplicadas imediatamente antes da infusão de NPS ou soro glicosado, a cada hora durante a infusão e imediatamente após a realização dos exames de P300 e MMN, realizados após o fim da infusão. RESULTADOS: A infusão de NPS foi associada a um aumento significativo da amplitude do potencial evocado MMN e a uma redução nos escores das escalas de sintomas psiquiátricos BPRS e PANSS em comparação com o placebo. CONCLUSÃO: A infusão de NPS foi associada à melhora dos sintomas de esquizofrenia conforme medidos pela BPRS e PANSS e a um aumento da amplitude do potencial evocado MMN. Não houve efeitos da administração do NPS sobre o potencial evocado P300. / INTRODUCTION: Schizophrenia is a mental disorder characterized by disorganization of several mental processes including cognition. Schizophrenia patients present alterations in the amplitude and latency of auditory evoked potentials P300 and MMN. Most current antipsychotics have little or no effect on the negative symptoms or cognitive impairment in schizophrenia, which led researchers to search for pharmacological alternatives that may counteract these manifestations. Recent evidence suggests that sodium nitroprusside (SNP) is able to ameliorate some of the manifestations associated with schizohrenia that do not respond adequately to currently available treatments. OBJECTIVE: To investigate the effects of SNP on schizophrenia symptoms and on the evoked potentials P300 and MMN in a double-blind, placebocontrolled trial. METHODS: The trial involved 12 patients aged 25-54 years in antipsychotic treatment followed up at the Ribeirã Preto Medical School University Hospital. Each patient attended two experimental sessions, one for the infusion of SNP and another for the infusion of placebo. The Brief Psychiatric Rating Scale (BPRS) and the Positive and Negative Syndromes Scale (PANSS) were completed immediately before the infusion, every consecutive hour, and immediately after the P300 and MMN tests, performed after the end of the infusion. RESULTS: The infusion of SNP was associated with a significant increase in the amplitude of MMN and with a reduction in the psychopathology scores of the BPRS and PANSS compared to placebo. CONCLUSION: The administration of SNP was associated with an improvement in schizophrenia symptoms as measured with the BPRS and PANSS and with an increase in the amplitude of the evoked potential MMN. There were no effects of SNP on the evoled potential P300.
6

Effects of the NO donors Sodium Nitroprusside andS-nitrosoglutathione on oxygen consumption and embryonic organ growth in the domestic broiler chicken,Gallus gallus domesticus.

Ekström, Andreas January 2010 (has links)
<p>Nitric oxide (NO) is an important chemical factor that controls vascular tone in the cardiovascular system. NO is a vasodilatory molecule that plays a role in blood pressure and blood flow regulation as well as vessel formation and tissue cell proliferation. NO influences the flow by which nutrients and other metabolites required for growth are transported to the tissues. The aim of this study was to investigate if NO, through mediation by the NO donors Sodium Nitroprusside (SNP) and S-Nitrosoglutathione (GSNO) affect growth and oxygen consumption of prenatal broiler chicken. The results indicate that, although the treatments did not have clear significant effects on the embryos or the organs examined, a slight delay in development can be observed in the GSNO treatment embryos. The study could not conclude, however, if this was due to effects of NO donors</p>
7

Assessment of microvascular function by use of transdermal iontophoresis : methodological aspects

Droog Tesselaar, Erik January 2007 (has links)
Assessment of the microcirculation is of major importance in understanding the physiology of the vasculature and in assessing te vascular effects of pathological conditions such as diabetes, hypertension and sepsis. Transdermal iontophoresis can be used to non‐invasively introduce vasoactive drugs into the skin. The response to these drugs of the local cutaneous microvasculature can be measured by laser Doppler flowmetry methods. Although these techniques have been used together for over two decades, there are still important methodological issues to be resolved. This work is aimed at optimizing transdermal iontophoresis as a tool for microvascular assessment by focusing on the main methdological issues: non‐specific vasodilatation, drug delivery protocols and analysis of blood flow data. Non‐specific vasodilatation, an increase blood flow during iontophoresis of non‐vasoactive compounds, is an important problem as it interferes with the response to the administered drug. By investigating this effect in healthy volunteers, we found that the extent of the non‐specific response differs between the positive and negative electrode and that it is dependent on the voltage over the skin andon the ionic strength of the vehicle in which the drug is dissolved. We also found that the extent of the non‐specific response could be reduced by applying local anesthetics and by pre‐treatment with antihistamine drugs. These results suggest that non‐specific effects could be mediated by depolarization or hyperpolarisation of cells, triggering neural and histamine related mechanisms that finally lead to vasodilatation of the local microvasculature. To prevent non‐specific effects from occurring during the experiments, our results show that the current strength and the total electric charge during iontophoresis should be limited to 0.02 mA and12 mC, respectively. Furthermore, drug solutions at physiological ionic strengths should be used. Under these conditions, adequate responses to the most commonly used drugs, acetylcholine (ACh) and sodium nitroprusside (SNP), are obtained while no significant non‐specific vasodilatation occurs. The results of our investigations show that blood responses to ACh and SNP applied by a single iontophoretic pulse can well be escribed by conventional dose‐response models, which enables a more powerful analysis and comparison between drugs or possibly patient groups as compared with conventional aalysis methods. Finally, we have incorporated drug transport and physiological response to the local drug concentration during iontophoresis of vasoactve drugs into a single model. Validation of this model using measured responses to ACh and SNP shows that the commonly used assumption that the local drug concentration during iontophoresis is linearly proportional to the electric charge may not be valid. / Mikrocirkulationen, som inbegriper kroppens minsta blodkärl, transporterar syre och näringsämnen till våra celler. Vissa sjukdomar, som diabetes, hjärt‐kärlsjukdom och akut blodförgiftning leder till förändringar hos mikrocirkulationen. Mekanismerna bakom dessa förändringar är delvis okända. Det finns därför ett stort behov av kliniska mättekniker som kan bedöma mikrocirkulationens funktion. Vid jontofores placeras en elektrod tillsammans med ett läkemedel på huden. När en svag elektrisk ström anbringas transporteras läkemedlet ner genom hudlagren. Effekterna av ett kärlaktivt läkemedel som appliceras på detta sätt kan sedan avläsas non‐invasivt med laser Doppler‐teknik. En stor fördel med jontoforesmetoden, förutom att den är non‐invasiv, är att läkemedelsdoserna som tillförs kroppen är mycket små och därmed ger de inte upphov till några systemiska bi‐effekter. I avhandlingen presenteras forskning, vilkas målsättning är att lösa några av de viktiga frågorna kring transdermal jontofores så att tekniken optimeras för att denskall kunna brukas som ett verktyg vid kliniska undersökningar av mikrocirkulationen. Den första delen ägnas ett fenomen som kallas ospecifik vasodilatation. Det uppstår vid jontofores av substanser som är inte kärlaktiv, som vatten och koksaltlösning. Resultaten från dessa försök indikerar att den ospecifika vasodilatationen beror på framför allt spänningen över huden, vilken i sin tur är relaterad till jon‐koncentrationen hos läkemedelslösningen. Vidare registreras att mekanismen bakom den ospecifika vasodilatationen delvis är neuralt medierad genom att de till stor del år att förhindra med hjälp av lokal bedövning. Dessutom leder förbehandling med anti‐histamina läkemedel till minskade ospecifika reaktioner, vilket också indikerar att lokala inflammatoriska processer är inblandande. Den andra delen av avhandlingen ägnas att optimera försöksprotokollen för jontofores. Till att börja med utvecklas ett protokoll som ger ett adekvat läkemedelssvar samtidigt som ospecifika effekter minimeras. Det visar sig är möjligt genom att begränsa strömstyrkan och den elektriska laddningen under jontoforesen och genom att använd läkemedelslösningar som har en fysiologisk jonstyrka. Resultaten visar också att blodflödesförändringen som registreras under jontofores av acetylkolin och natriumnitroprussid kan eskrivas med hjälp av konventionella dos‐responsmodeller, vilket möjliggör en mer exakt analys av det mikrocirkulatoriska svaret samt underlättar jämförelse mellan olika läkemedel elle patientgrupper. Slutligen presenteras en mekanistisk model för det mikrocirkulatoriska svaret vid jontofores. Modellen beskriver läkemedlets transport från elektroden ner genom huden, clearance i huden vilken beror på diffusion och det lokala blodflödet, samt förändringen i blodflöde som sker på grund av läkemedlet. Modellen valideras genom försök på försökspersoner och resultaten visar att förändringarna i blodflödet åstadkommet av acetylklin och natriumnitroprussid med denna modell kan beskrivas på ett exakt sätt. Vidare visar resultaten att det sker en betydande clearance av läkemedel i huden under jontofores. Detta har väsentlig betydelse när man ska uppskatta den lokala jontoforesdosen. / The author changed surname from Droog to Tesselaar in January 2006.
8

Effects of the NO donors Sodium Nitroprusside andS-nitrosoglutathione on oxygen consumption and embryonic organ growth in the domestic broiler chicken,Gallus gallus domesticus.

Ekström, Andreas January 2010 (has links)
Nitric oxide (NO) is an important chemical factor that controls vascular tone in the cardiovascular system. NO is a vasodilatory molecule that plays a role in blood pressure and blood flow regulation as well as vessel formation and tissue cell proliferation. NO influences the flow by which nutrients and other metabolites required for growth are transported to the tissues. The aim of this study was to investigate if NO, through mediation by the NO donors Sodium Nitroprusside (SNP) and S-Nitrosoglutathione (GSNO) affect growth and oxygen consumption of prenatal broiler chicken. The results indicate that, although the treatments did not have clear significant effects on the embryos or the organs examined, a slight delay in development can be observed in the GSNO treatment embryos. The study could not conclude, however, if this was due to effects of NO donors
9

Óxido nítrico como agente amenizador do estresse salino em alface semi-hidropônica /

Marques, Isabelly Cristina da Silva January 2020 (has links)
Orientador: João Domingos Rodrigues / Resumo: Perante a atual demanda hídrica para manutenção de cultivos intensos e sucessivos, faz-se necessária a busca de alternativas para o manejo correto da água a fim de reduzir seu desperdício. Uma dessas alternativas se concentra na utilização de águas de qualidade inferior como, por exemplo, águas salobras. No entanto, uso de águas salobras podem ocasionar diversas alterações no metabolismo das plantas, necessitando de estratégias que permitam o uso dessas águas. Na busca dessas alternativas, busca-se substâncias biológicas ou sintéticas que gerem respostas fisiológicas e bioquímicas que promovam a adaptação das plantas às condições ambientais adversas, a exemplo do óxido nítrico (NO). Partindo desse pressuposto, objetivou-se com este trabalho avaliar o efeito atenuante do óxido nítrico em plantas de alface crespa, cv. Vera, cultivada sob estresse salino. O experimento foi realizado em casa de vegetação nos meses de abril e maio de 2019, da Fazenda Experimental de São Manuel da FCA, localizada no município de São Manuel/SP. O delineamento experimental adotado foi o de blocos ao acaso, em esquema fatorial de 5 x 2, sendo o primeiro fator compreendido por cinco concentrações de nitroprussiato de sódio (NPS) (0, 50, 100, 150 e 200 µmol) e o segundo fator foi composto por dois níveis salinos da água de irrigação (0,2 e 3,5 dS m-1, respectivamente, sem e com estresse salino), com quatro repetições. As concentrações de NPS foram aplicadas semanalmente (via foliar), totalizando três ap... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In view of the current water demand for maintaining intense and successive crops, it is necessary to search for alternatives for the correct management of water in order to reduce its waste. One of these alternatives focuses on the use of lower quality water, such as brackish water. However, the use of brackish water can cause several changes in the metabolism of plants, requiring strategies that allow the use of these waters. In the search for these alternatives, biological or synthetic substances are sought that generate physiological and biochemical responses that promote the adaptation of plants to adverse environmental conditions, such as nitric oxide (NO). Based on this assumption, the aim of this study was to evaluate the attenuating effect of nitric oxide on crisp lettuce plants, cv. Vera, grown under salt stress. The experiment was carried out in a greenhouse in the months of April and May 2019, at the São Manuel da FCA Experimental Farm, located in the municipality of São Manuel / SP. The experimental design adopted was that of randomized blocks, in a 5 x 2 factorial scheme, the first factor being comprised of five concentrations of sodium nitroprusside (SNP) (0, 50, 100, 150 and 200 µmol) and the second factor was composed of two saline levels of irrigation water (0.2 and 3.5 dS m-1, respectively, without and with salt stress), with four repetitions. SNP concentrations were applied weekly (via leaf), totaling three applications during the cycle. The variables analy... (Complete abstract click electronic access below) / Mestre
10

α-Lipoic Acid Protected Cardiomyoblasts From the Injury Induced by Sodium Nitroprusside Through ROS-Mediated Akt/Gsk-3β Activation

Jiang, Surong, Zhu, Weina, Wu, Jun, Li, Chuanfu, Zhang, Xiaojin, Li, Yuehua, Cao, Kejiang, Liu, Li 01 December 2014 (has links)
It has been long noted that cardiac cell apoptosis provoked by excessive production of nitric oxide (NO) plays important roles in the pathogenesis of variant cardiac diseases. Attenuation of NO-induced injury would be an alternative therapeutic approach for the development of cardiac disorders. This study investigated the effects of α-lipoic acid (LA) on the injury induced by sodium nitroprusside (SNP), a widely used NO donor, in rat cardiomyoblast H9c2 cells. SNP challenge significantly decreased cell viability and increased apoptosis, as evidenced by morphological abnormalities, nuclear condensation and decline of mitochondrial potential (δ. Ψm). These changes induced by SNP were significantly attenuated by LA pretreatment. Furthermore, LA pretreatment prevented the SNP-triggered suppression of Akt and Gsk-3β activation. Blockade of Akt activation with triciribin (API) completely abolished the cytoprotection of LA against SNP challenge. In addition, LA moderately increased intracellular ROS production. Interestingly, inhibition of ROS with N-acetylcysteine abrogated Akt/Gsk-3β activation and the LA-induced cytoprotection following SNP stimulation. Taken together, the results indicate that LA protected the SNP-induced injury in cardiac H9c2 cells through, at least in part, the activation of Akt/Gsk-3β signaling in a ROS-dependent mechanism.

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