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Summary: The effects of clonidine, a central alpha2 agonist, on changes in blood pressure caused by muscle afferent nerve (ergoreceptor) activation and baroreceptor manipulation were studied in cats. Prolonged isometric contractions (ergoreceptor activation) of the gastrocnemius and plantaris muscles increased mean arterial pressure by 53 mmHg. This pressor response was not altered by naloxone (0.5 μmol·litre-1) but was eliminated by clonidine (0.5-2.0 μg) when injected into the cerebral aqueduct. Brief occlusion of the carotid artery (15-30 s) caused mean arterial pressure to increase by 32-42 mmHg at rest. Neither naloxone nor clonidine altered the magnitude of the reflex pressor response to carotid occlusion. Similar increases in pressure were measured when occlusion was applied during fatiguing isometric contractions; thus baroreceptor induced increases in pressure were superimposed on the ergoreceptor induced blood pressure changes. Naloxone did not affect the changes in pressure caused by either reflex response. Clonidine continued to eliminate the pressor response to muscular contraction but did not affect the pressure increase when the carotid occlusion was applied during contractions. Electrical stimulation of the carotid sinus nerve caused blood pressure to decrease by 36 mmHg during rest and by 41 mmHg during fatiguing isometric contractions. Clonidine did not alter the depressor response to carotid sinus nerve stimulation. These data may indicate that separate pathways centrally mediate the changes in blood pressure caused by ergoreceptor and baroreceptor afferent activation. The integration of the ergoreceptor pathway may involve a catecholaminergic-opioidergic system but the present results do not suggest a similar interaction for the baroreceptor integration.

A medida da pressão arterial é um procedimento simples e imprescindível na avaliação do sistema cardiovascular, porém sua realização sofre influências de diversos fatores que podem comprometer os valores obtidos. As estratégias de ensino da técnica de medida da pressão arterial utilizam as aulas expositivas e filmes de treinamento, porém o ambiente digital ainda não foi explorado. O ambiente digital de aprendizagem tem-se constituído em uma poderosa ferramenta do processo de ensino aprendizagem, pois acrescenta significado e concretude aos conteúdos que precisam ser aprendidos. A graduação em enfermagem tem sido beneficiada pelo uso da tecnologia de informação no ensino de seus procedimentos e técnicas, embora as iniciativas nesta área sejam ainda incipientes. O objetivo deste trabalho foi construir uma hipermídia educacional para o ensino da técnica de medida da pressão arterial para graduandos de enfermagem e descrever as etapas do processo de construção. O referencial pedagógico adotado para nortear a elaboração do conteúdo foi de Robert Gagné, e seguiu-se o modelo em três fases proposto por Price para a construção da hipermídia. O produto final contou com quatro tópicos, agrupando 12 módulos, no qual se apresenta todas as questões que envolvem a realização do procedimento de medida da pressão arterial, discorrendo sobre aspectos fisiológicos, métodos e técnica de medida. A hipermídia utiliza os recursos de áudio, vídeo, animações bidimensionais, fotos, ilustrações e simulações. A avaliação foi realizada simultaneamente por três grupos de juízes técnicos em informática; docentes de enfermagem e profissionais da saúde; e por alunos de graduação em enfermagem, utilizando instrumentos de avaliação específicos para cada grupo. Estas avaliações foram analisadas separadamente, os resultados apresentaram semelhanças entre os grupos que se detiveram em questões organizacionais, estéticas e informacionais. De maneira geral, os grupos avaliaram bem a hipermídia, com comentários positivos a respeito da estratégia e da qualidade final do ambiente desenvolvido. O uso da hipermídia e do ambiente digital de aprendizagem pode representar uma importante estratégia para o ensino da enfermagem, porém o desenvolvimento de ferramentas educacionais adequadas a este ambiente é um campo novo em franca expansão que necessita de avaliação e adequação periódicas / Arterial blood pressure measurement is a simple and essential conduct to evaluate the condition of the cardiovascular system; however, it is afected by several factors that can change the obtained results. Lectures and training movies are used as teaching strategies of blood pressure measurement technique, but digital environment has not been explored so far. Digital teaching environment is a powerful tool for the teaching-learning process, because it adds meaning and concreteness to the subjects to be learned. The use of information technology in the teaching of nursing procedures and techniques has benefit Nursing Undergraduate courses, although the iniciatives in this area are still incipients. This work intended to build an educational hypermedia to the arterial blood pressure measurement teaching for undergraduate nursing students, and to describe the steps of the building process. The development of the content used a pedagogical reference by Robert Gagné as guidance, and followed the three-phase model proposed by Price for the hypermedia construction. The final product has 12 modules within 4 topics, and presents all questions concerning the procedure to the arterial blood pressure measurement, considering methods, measurement technique and physiological aspects. Hypermedia uses resources as audio, video, two-dimensional animations, photos, pictures and simulations. The evaluation was made simultaneously by three groups of judges: computer science technicians; teachers of nursing and health professionals´ courses, and nursing undergraduate students, using specific evaluation tools for each group. The evaluations were analysed on an individual basis; the results showed some similarities, mainly in organizational, aesthetical and informational issues. On the whole, the groups made an approving evaluation of the hypermedia, with positive comments about the strategy and final quality of the developed environment. The use of hypermedia and digital learning environment can represent an important strategy to nursing teaching; however, the development of teaching tools that are suitable to this environment is a new and expanding field that requires periodical evaluation and adjustments

Monitoring of cerebral oxygenation, cerebrovascular reactivity and circulatory function in preterm infants Brain injury in the preterm infant is associated with death and lifelong disability. Cerebral hypoxia and fluctuations in cerebral blood flow in the first two days of life have been implicated in the pathophysiology of haemorrhagic and ischaemic brain injury. Monitoring of haemodynamic changes during the early transitional circulation from in-utero to ex-utero life are currently based on standard measurements of systemic oxygenation and mean arterial blood pressure, with no reliable assessment of end-organ perfusion. In this thesis, measurements using near-infrared spectroscopy (NIRS) and functional echocardiography were made to assess cerebral perfusion and systemic blood flow in a cohort of preterm infants undergoing intensive care. This thesis is divided into four sections: i) The feasibility of continuous monitoring of cerebral oxygenation and cerebrovascular reactivity is demonstrated in a series of case reviews, and the association between cerebral oxygenation and cerebrovascular reactivity with outcome of brain injury and mortality is described. ii) Combining measurements of systemic blood flow with end organ perfusion was applied to define MABPOPT in preterm infants based on an index of cerebrovascular reactivity. Deviations below MABPOPT were associated with intraventricular haemorrhage and mortality. iii) The complexity of brain and systemic signals was studied by using multi-scale entropy analysis. Most studies using cerebral NIRS or systemic measurements of blood flow use linear analysis; however, a complex biological system, such as the human brain, includes many regulatory mechanisms that interact in a complex manner, resulting in effects that cannot be understood wholly through the analysis of its individual constituents. Lower complexity of brain signals was observed in infants who developed intraventricular hemorrhage or died. iv) Changes in systemic and cerebral oxygenation in a cohort of preterm infants in the first 48 hours of life was assessed using functional echocardiography. The patterns of changes in cardiac output and cerebral oxygenation in infants who did and did not have intraventricular haemorrhage are discussed. Furthermore, the relationship between the presence of a haemodynamically significant ductus arteriosus and brain injury is assessed.

Long-term adaptation of cardiovascular system in response to regular physical activity depends not only on its type, intensity and volume, but on arterial blood pressure (ABP) during exercise as well. Although it is proved haemodynamic load is not the only factor responsible for the shaping of athlete's myocardium, both the extent and the type of cardiac remodelling are influenced greatly by the degree of pressure overload during exercise training. The aim of our study was to compare myocardium loading conditions during veloergometric and treadmill interval tests. Methods. Distance runners (all males, n = 16) served as subjects. Their age was 23.6 ± 5.5 yrs, body mass – 70.7 ± 4.7 kg, body mass index – 21.7 ± 1.9 kg/m2, training experience – 8.7 ± 5.6 yrs. Interval tests were applied on separate days. Each of them consisted of increasing intensity exercise interspaced with passive resting period (in seated position) of 4 min in duration. Heart rate (HR) was recorded throughout both tests while ABP was measured during recovery period between treadmill stages. Tests were continued till HR reached 90 percent of age-predicted maximum. Results. Systolic ABP, HR and double product were higher (p<0.05) after the discontinuation of veloergometric workload as compared with treadmill load requiring similar oxygen consumption. Runners' systolic ABP response was bigger to veloergometry as compared with treadmill running eliciting the same HR (p<0.05). Significant correlation was found... [to full text]

Darbo tikslas: Nustatyti padidėjusio arterinio kraujospūdžio paplitimą tarp 14-15 metų amžiaus vaikų ir įvertinti veiksnių įtaką jo rizikai. Uždaviniai: .Nustatyti padidėjusio arterinio kraujospūdžio paplitimą tarp 14- 15 metų amžiaus vaikų;Nustatyti kai kurių aplinkos veiksnių įtaką arterinio kraujospūdžio rizikai; Įvertinti sąsajas tarp padidėjusio arterinio kraujo spaudimo ir analizuotų rizikos veiksnių. Tyrimo metodika. Gavus Kauno regioninio biomedicininių tyrimų etikos komiteto leidimą, 2010 m. lapkričio mėnesį buvo pradėtas tyrimas, kuriame dalyvavo 56- ių Kauno miesto mokyklų 12-15 metų amžiaus moksleiviai. Arterinis kraujo spaudimas buvo išmatuotas 2692 moksleiviams, 1468 mergaitėms ir 1224 berniukams. Atlikus matavimus vaikams buvo pateiktos anketos, kuriose buvo 80 klausimų. Klausimynas suskirstytas į grupes: bendroji dalis, mityba, emocijos, aktyvumas, miegas ir elgsena. Gautų rezultatų analizė buvo atlikta, naudojant SPSS 17.0 for Windows, Exel 2007 programas. Rezultatai. Analizuojant Kauno miesto moksleivių AKS rodmenis buvo nustatyta, kad 57,4 proc. 14-15 metų amžiaus moksleivių neturi problemų su kraujospūdžio padidėjimu. 26,4 proc. moksleivių buvo nustatytas aukštas normalus AKS (atitinkantis prehipertenzijos lygį), o 16,2 proc. nustatytas padidėjęs AKS (atitinkantis I ir II laipsnio hipertenziją (AH)). Gauti rezultatai parodė didesnę AKS riziką berniukams. Gimnazijose padidėjęs AKS sudarė 42,4 proc. , vidurinėse mokyklose 43,3 proc. o pagrindinėse 39,7 proc... [toliau žr. visą tekstą] / Aim of the research. To identify diffusion of raised arterial blood pressure among 14-15 year olds and to evaluate the factors of the risk. Objectives of the research: to identify prevalence of raised arterial blood pressure among 14-15 year olds; to set some environmental factors on the risk of arterial blood pressure; to evaluate the correlation between the increased arterial blood pressure and analyzed risk factors. Methodology of the research: In November 2010, upon thepermit of Kaunas region Regional Biomedical Research Ethics Committee the research was started in which 12-15 year old pupils from 56 schools in Kaunas took part. The arterial blood pressure was measured for 2692 pupils – 1468 girls and 1224 boys.After accomplishing the measurements pupils weregiven a questionnaire, consisting of 80 questions. The questionnaire was divided into parts: common part, nutrition, emotions, activities, rest and behavior. The analysis of the results was carried out by using SPSS 17.0 for Windows and Exel 2007 programs. Results of the research. During the analysis of the data received it was identified that 57,4 % of 14-15 year olds do not meet the problem of increased blood pressure. 26,4 % have high normal ABP (corresponding to the level of prehypertensia), and increased ABP was identyfied to 16,2 %. (corresponding to I and II degree hypertensia (AH)). The obtained results indicated ABP risk to boys. Gymnasiums had 42.4 %. of whom had increased ABP as well as in secondary... [to full text]

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-10-23T17:18:48Z No. of bitstreams: 1 Daniela Almeida Participaçao dos receptores....pdf: 1297031 bytes, checksum: 754812103a71d951c868e902bd43f90c (MD5) / Made available in DSpace on 2012-10-23T17:18:48Z (GMT). No. of bitstreams: 1 Daniela Almeida Participaçao dos receptores....pdf: 1297031 bytes, checksum: 754812103a71d951c868e902bd43f90c (MD5) Previous issue date: 2012 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / Situações de estresse repetido ou prolongado podem resultar em vários estados patológicos, como hipertensão arterial, arritmias cardíacas, infarto do miocárdio e até mesmo morte súbita. Embora se tenha muita informação sobre o controle cerebral da pressão arterial, as respostas cardiovasculares ao estresse não são totalmente compreendidas. Dados da literatura mostram a importância do núcleo medial da amigdala (MeA) e da neurotrasmissão histaminérgica no controle autonômico das funções cardiovasculares, no entanto, não há estudos evidanciando o papel das vias histaminérgicas no MeA nas adaptações cardiovasculares evocada pelo estresse emocional. Desta forma, o objetivo desta pesquisa foi estudar a participação dos receptores H1 e H2 no MeA sobre as respostas cardiovasculares em ratos estressados e não-estressados. Ratos Wistar (280-320g) foram submetidos à cirurgia estereotáxica para canulação bilateral do MeA. Passado cinco dias da estereotaxia, os animais foram submetidos a cateterização da artéria carótida esquerda. Vinte e quatro horas após a inserção do cateter, foram iniciados os experimentos com a gravação do registro da pressão arterial pulsátil (PAP) dos animais em condições basais e em livre movimento em suas respectivas caixas de forma continuada. As drogas utilizadas para a microinjeção central foram a mepiramina (antagonista dos receptores H1) nos grupos experimentais I e III e a cimetidina (antagonista dos receptores H2) nos grupos experimentais II e IV. Nos grupos experimentais I e II, 15 min após microinjeção central bilateral de mepiramina ou cimetidina respectivamente, em diferentes doses, os animais foram submetidos a estresse de restrição de movimentos em tubos de polietileno, e a PAP foi registrada continuamente durante 45 min. Após o período de estresse, os animais foram realocados em suas caixas e a PAP foi registrada por mais 30 min. Nos grupos experimentais III e IV, após as microinjeções centrais bilaterais no MeA, a PAP continuou sendo registrada por 75 min em animais sob condições basais e em livre movimento (não estressados). Os animais controles de todos os grupos experimentais receberam microinjeções de salina 0,9%. Os experimentos foram realizados entre 7h00min às 13h00min e os animais não tiveram acesso à água ou ração durante o experimento. Os dados estão expressos como média±E.P.M das variações da PAM e FC. Microinjeções de mepiramina nas doses de 50, 100 e 200 nmol promoveu bloqueio dose-dependente da resposta hipertensiva evocada pelo estresse de restrição. A cimetidina (100 e 200 nmol) atenuou a resposta hipertensiva ao estresse apenas na maior dose utilizada. A resposta anti-hipertensiva ao estresse foi maior nos animais que receberam microinjeções de mepiramina do que de cimetidina nas mesmas doses. Nenhuma das drogas alterou a resposta taquicárdica típica do estresse. Mepiramina ou cimetidina foram incapazes de alterar a PAM ou a FC de animais não estressados. Os dados sugerem que as vias histaminérgicas presentes no MeA medeiam a resposta pressora sem alterar a taquicardia evocadas pelo estresse de restrição, ativando preferencialmente os receptores do tipo H1. Além disto, os dados confirmam a hipótese de que a via histaminérgica no MeA não exerce modulação tônica do sistema cardiovascular. A obtenção de dados adicionais relativos ao papel fisiológico dos receptores histaminérgicos centrais no controle das funções cardiovasculares se reveste de grande importância para as ciências biológicas e para a clínica médica, principalmente quando vinculada à variável estresse. Os resultados deste trabalho contribuem para o esclarecimento da participação destes receptores no controle das funções cardiovasculares. / Repeated long lasting experiences of stress situations may result in various pathologic states such as arterial hypertension, cardiac dysrhythmias, myocardial stroke and even sudden death. Although there is a lot information about the neural control of the arterial blood pressure, especially by the brain stem and some other prosencephalic areas, stress-evoked cardiovascular responses are not totally understood. Previews studies shows the importance of the medial amygdala nucleus (MeA) and of the histaminergic neurotransmission on the autonomic control of cardiovascular functions, however there aren’t studies that evidence the role of the histaminergic pathways in MeA on emotional stress-evoked cardiovascular adaptations. Therefore, the aim of this study was investigate the participation of the histaminergic receptors H1 and H2 in MeA on the cardiovascular responses in stressed and non-stressed rats. Wistar rats (280-320g) were submitted to stereotaxic surgery for bilateral cannulation of MeA. Five days after surgery, animals were submitted to catheterization of the left carotid artery. Twenty four hours after catheter insertion, experiments were started and the pulsatile arterial pressure (PAP) of freely moving rats on basal conditions was recorded. Drugs used for central administration were mepyramine (H1 receptors antagonist) on experimental groups I and III and cimetidine (H2 receptors antagonist) on experimental groups II and IV. At experimental groups I and II, 15 min after central microinjections of mepyramine or cimetidine respectively, in different doses, the rats was submitted to restraint stress in a polyvinyl apparatus, and PAP were continuously recorded for 45 min. After stress period, rats were replaced in their own cages and an additional 30 min were recorded for PAP reestablishment. At experimental groups III and IV, after 30 min of basal recording, rats received bilateral central microinjections of mepyramine or cimetidine in a dose of 200 nmol, respectively, and an additional period of 75 min was recorded in freely moving rats on basal conditions. Saline 0,9% was administered as vehicle in control animals of all experimental groups. Mean arterial pressure (MAP) and heart rate (HR) were, then, calculated from the PAP signal. Experiments occurred between 7:00 and 13:00 and rat did not have access to water and food during the sessions. Data were expressed as mean±S.E.M. of MAP and HR variation. Mepyramine microinjections at doses of 50, 100 and 200 nmol promoted dose-dependent blockade of the restraint stress-evoked hypertensive response. Cimetidine (100 and 200 nmol) attenuated the hypertensive response to stress only at the highest dose administered. The anti-hypertensive response was bigger on animals which received mepyramine than cimetidine. Neither drugs altered the typical stress-evoked tachycardiac responses. Indeed, mepyramine or cimetidina were unable to modify the MAP or HR of freely moving rats on basal conditionals (non-stressed rats). These data suggest that histaminergic pathways in MeA mediates pressor responses without modifying the tachycardia promoted by restraint stress, activating preferentially H1 receptors. Besides, data corroborate to the hypothesis that histaminergic pathways in MeA do not plays tonic modulation of the cardiovascular system. Additional information acquired about physiologic role of central histaminergic receptor on the cardiovascular functions is important to biological science and to medical practice, especially when linked to the stress factor. These data contribute to clarify the role of these receptors on cardiovascular functions

A medida da pressão arterial é um procedimento simples e imprescindível na avaliação do sistema cardiovascular, porém sua realização sofre influências de diversos fatores que podem comprometer os valores obtidos. As estratégias de ensino da técnica de medida da pressão arterial utilizam as aulas expositivas e filmes de treinamento, porém o ambiente digital ainda não foi explorado. O ambiente digital de aprendizagem tem-se constituído em uma poderosa ferramenta do processo de ensino aprendizagem, pois acrescenta significado e concretude aos conteúdos que precisam ser aprendidos. A graduação em enfermagem tem sido beneficiada pelo uso da tecnologia de informação no ensino de seus procedimentos e técnicas, embora as iniciativas nesta área sejam ainda incipientes. O objetivo deste trabalho foi construir uma hipermídia educacional para o ensino da técnica de medida da pressão arterial para graduandos de enfermagem e descrever as etapas do processo de construção. O referencial pedagógico adotado para nortear a elaboração do conteúdo foi de Robert Gagné, e seguiu-se o modelo em três fases proposto por Price para a construção da hipermídia. O produto final contou com quatro tópicos, agrupando 12 módulos, no qual se apresenta todas as questões que envolvem a realização do procedimento de medida da pressão arterial, discorrendo sobre aspectos fisiológicos, métodos e técnica de medida. A hipermídia utiliza os recursos de áudio, vídeo, animações bidimensionais, fotos, ilustrações e simulações. A avaliação foi realizada simultaneamente por três grupos de juízes técnicos em informática; docentes de enfermagem e profissionais da saúde; e por alunos de graduação em enfermagem, utilizando instrumentos de avaliação específicos para cada grupo. Estas avaliações foram analisadas separadamente, os resultados apresentaram semelhanças entre os grupos que se detiveram em questões organizacionais, estéticas e informacionais. De maneira geral, os grupos avaliaram bem a hipermídia, com comentários positivos a respeito da estratégia e da qualidade final do ambiente desenvolvido. O uso da hipermídia e do ambiente digital de aprendizagem pode representar uma importante estratégia para o ensino da enfermagem, porém o desenvolvimento de ferramentas educacionais adequadas a este ambiente é um campo novo em franca expansão que necessita de avaliação e adequação periódicas / Arterial blood pressure measurement is a simple and essential conduct to evaluate the condition of the cardiovascular system; however, it is afected by several factors that can change the obtained results. Lectures and training movies are used as teaching strategies of blood pressure measurement technique, but digital environment has not been explored so far. Digital teaching environment is a powerful tool for the teaching-learning process, because it adds meaning and concreteness to the subjects to be learned. The use of information technology in the teaching of nursing procedures and techniques has benefit Nursing Undergraduate courses, although the iniciatives in this area are still incipients. This work intended to build an educational hypermedia to the arterial blood pressure measurement teaching for undergraduate nursing students, and to describe the steps of the building process. The development of the content used a pedagogical reference by Robert Gagné as guidance, and followed the three-phase model proposed by Price for the hypermedia construction. The final product has 12 modules within 4 topics, and presents all questions concerning the procedure to the arterial blood pressure measurement, considering methods, measurement technique and physiological aspects. Hypermedia uses resources as audio, video, two-dimensional animations, photos, pictures and simulations. The evaluation was made simultaneously by three groups of judges: computer science technicians; teachers of nursing and health professionals´ courses, and nursing undergraduate students, using specific evaluation tools for each group. The evaluations were analysed on an individual basis; the results showed some similarities, mainly in organizational, aesthetical and informational issues. On the whole, the groups made an approving evaluation of the hypermedia, with positive comments about the strategy and final quality of the developed environment. The use of hypermedia and digital learning environment can represent an important strategy to nursing teaching; however, the development of teaching tools that are suitable to this environment is a new and expanding field that requires periodical evaluation and adjustments