RESUMO
Objetivo: Explorar la práctica pedagógica docente en la formación para el cuidado de enfermería en la Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas. Material y método: Estudio cualitativo, exploratorio, descriptivo: la muestra la conformaron 21 informantes. La recolección de información fue por medio de entrevista semi estructurada. El análisis siguió un proceso de codificación abierta, axial y selectiva hasta obtener categorías emergentes. Resultados: Se identificaron las siguientes categorías: I) Convivencia y relaciones de cuidado/descuido en la formación de enfermería; II) (Des)articulación teórico- práctica en la enseñanza/aprendizaje del cuidado de enfermería: hacia la integración docente-asistente; III) Complementariedad docente/estudiante para la construcción de conocimiento y estrategias didácticas. Conclusiones: La pedagogía para el cuidado de enfermería se evidencia en un espacio de cuidado/descuido, demandan integración docencia-asistencia y se motivan para el fortalecimiento de competencias pedagógico didácticas, a través del aprendizaje basado en problemas, casos hipotéticos, laboratorios vivenciales y sociodramas e incluir como ejes trasversales el cuidado y la investigación.
Objective: To explore the pedagogical practice in nursing care formation among teachers of the Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas. Method and materials: This is a qualitative, exploratory and descriptive study, with a sample of 21 informants. Data were gathered using semi-structured interviews. The analysis followed an open, axial, and selective coding process, until emerging categories were identified. Results: The following categories emerged: I) Co-living and care/negligence relationships in nursing formation; II) (Lack of) theory-practice articulation in teaching/learning nursing care: towards the teacher-assistant integration; III) Teacher/student complementarity in the construction of knowledge and didactical strategies. Conclusions: Pedagogy in nursing care is evidenced within a care/negligence space, and thus, it is necessary to strengthen the integration among teaching and assistance improving the pedagogical competencies through methodologies such as learning based on problem solving, presentation of hypothetical cases, use of laboratories, including those for high-fidelity simulation, among others.
Objetivo: Explorar a prática pedagógica docente na formação para o cuidado de enfermagem na Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas. Material e método: Estudo qualitativo, exploratório, descritivo: a amostra a conformaram 21 informantes. A recolecção de informação foi por meio de entrevista semiestruturada. A análise seguiu um processo de codificação aberta, axial e seletiva até obter categorias emergentes. Resultados: Identificaram-se as seguintes categorias: I) Convivência e relações de cuidado/descuido na formação de enfermagem; II) (Des)articulação teórico -prática no ensino/aprendizagem do cuidado de enfermagem: para a integração docente- assistente; III) Complementaridade docente/estudante para a construção de conhecimento e estratégias didáticas. Conclusões: A pedagogia para o cuidado de enfermagem evidencia-se em um espaço de cuidado/descuido, demandam integração, docência-assistência e motivam-se para o fortalecimento de competências pedagógico didáticas, através da aprendizagem, baseada em problemas, casos hipotéticos, laboratórios vivenciais e sociodramas e incluir como eixos transversais o cuidado e a pesquisa.
Assuntos
Humanos , Masculino , Feminino , Enfermagem , Capacitação Profissional , Docentes de EnfermagemRESUMO
We assessed the effects of 40 ocean outfalls on adjacent macrobenthic invertebrates. Data were obtained from a review of gray and peer-review literature. Different parameters describing the outfall characteristics were compiled (length, maximum depth, treatment level, flow and organic matter mass discharged). Exposure to wave action was represented by significant wave height. The magnitude of the effect was categorized in three impact levels and classified considering different ecological indicators. A theoretical predictive model was formulated in which the lower the organic matter and the higher the energy of the system, the lower the benthic impact. The main conclusion was that the general pattern of the succession of benthic communities brought about by ocean outfalls fits the model of Pearson-Rosenberg but with some deviations i) the probability of a significant impact is much lower, ii) not all the successional stages occur and, iii) the magnitude of the changes are usually lower.
Assuntos
Invertebrados/fisiologia , Oceanos e Mares , Animais , Organismos Aquáticos , Meio Ambiente , Monitoramento Ambiental , Sedimentos Geológicos , Modelos TeóricosRESUMO
BACKGROUND: Prevalences of childhood asthma and other atopic diseases are increasing worldwide, and so is the number of diagnostic methods and definitions used. We determined the occurrence of atopic diseases in Cuban children with a range of diagnostic approaches commonly used or proposed in epidemiological studies, and compared the different outcome measures. METHODS: A total of 398 Cuban schoolchildren between 5 and 13 years of age were diagnosed by International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, clinical examination, pre- and post-exercise spirometry, and skin prick testing. All results were considered separately, as well as jointly by using scores and definitions as described in the literature. RESULTS: Using questionnaire-based approaches, 21-39% of the children were positive for asthma, 9-19% for atopic dermatitis, and 15-46% for rhinoconjunctivitis. With spirometry, 7% of the children had asthma. Definitions based on a combination of questionnaire and spirometry results yielded asthma rates of 5%. Of all children, 6% wheezed on clinical examination, and only one child showed clinical signs of atopic dermatitis. Eleven percent of the children had a positive skin prick test. In total, 254 children (64%) had an atopic disease as based on the ISAAC questionnaire, and 263 (66%) based on all approaches used. CONCLUSION: Diagnostic outcomes on atopic diseases vary considerably depending on definition and methodology. Our results clearly demonstrate the need for consensus on diagnosing asthma and other atopic diseases in epidemiological studies. Based on the most commonly used ISAAC questionnaire, our data suggest prevalences of atopic diseases in Cuban children that rival those found in some other Latin American countries and developed nations with the highest prevalences in the world.
Assuntos
Hipersensibilidade Imediata/diagnóstico , Terminologia como Assunto , Adolescente , Criança , Pré-Escolar , Cuba/etnologia , Feminino , Humanos , Hipersensibilidade Imediata/epidemiologia , Masculino , Prevalência , Sons Respiratórios/diagnóstico , Testes Cutâneos , Espirometria , Inquéritos e QuestionáriosAssuntos
Canais de Cloreto/antagonistas & inibidores , Precondicionamento Isquêmico Miocárdico , Miocárdio/metabolismo , Inibidores da Angiogênese/farmacologia , Animais , Diuréticos/farmacologia , Glicolatos/farmacologia , Isquemia , Nitrobenzoatos/farmacologia , Perfusão , Coelhos , Reperfusão , Estresse Fisiológico , Fatores de TempoRESUMO
No other environmental variable of such ecological importance to estuarine and coastal marine ecosystems around the world has changed so drastically, in such a short period of time, as dissolved oxygen. While hypoxic and anoxic environments have existed through geological time, their occurrence in shallow coastal and estuarine areas appears to be increasing, most likely accelerated by human activities. Several large systems, with historical data, that never reported hypoxia at the turn of the 19th century (e.g., Kattegat, the sea between Sweden and Denmark) now experience severe seasonal hypoxia. Synthesis of literature pertaining to benthic hypoxia and anoxia revealed that the oxygen budgets of many major coastal ecosystems have been adversely affected mainly through the process of eutrophication (the production of excess organic matter). It appears that many ecosystems that are now severely stressed by hypoxia may be near or at a threshold of change or collapse (loss of fisheries, loss of biodiversity, alteration of food webs).
Assuntos
Ecossistema , Eutrofização , Oxigênio/metabolismo , Animais , Peixes , Sedimentos Geológicos , Compostos Orgânicos/metabolismo , Dinâmica PopulacionalRESUMO
This article reviews studies on the adaptation of the exocrine pancreas to dietary fat. We include all the latest information about the mechanisms that underlie the adaptation of the secretory mechanism of the exocrine pancreas to the amount and the type of dietary fat. We review the kinetics of pancreatic adaptation and the mediators of the adaptive response of the pancreas including cellular and molecular mechanisms (modulation of intracellular messengers and gene expression of the different enzymes and secretagogues involved in the adaptation process). At the same time we include our results in this field in dogs and humans.
Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Gorduras na Dieta/farmacologia , Pâncreas/fisiologia , Animais , Humanos , Pâncreas/efeitos dos fármacosRESUMO
The objective of this study was to examine the role of chloride (Cl-) channels in the myocardial protection of ischemic preconditioning (IP). Isolated rabbit ventricular myocytes were preconditioned with 10-minute simulated ischemia (SI) and 20-minute simulated reperfusion (SR) or not preconditioned (control). The myocytes then received 180-minute SI or 45-minute SI/120-minute SR. Indanyloxyacetic acid 94 (IAA-94, 10 micromol/L) or 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, 1 micromol/L) was administered before IP or before SI or SI/SR to inhibit Cl- channels. Electrophysiological studies indicate that these drugs, at the concentrations used, selectively abolished Cl- currents activated under hypo-osmotic conditions (215 versus 290 mOsm). IP significantly (P<0.001) reduced the percentage of dead myocytes after 60-minute (30.8+/-1.3%, mean+/-SEM), 90-minute (35.3+/-1.3%), and 120-minute (39.2+/-1.7%) SI compared with controls (44.7+/-1.6%, 54.5+/-1.3%, and 58.9+/-1.8%, respectively) and after 45-minute SI/120-minute SR (36.3+/-0.6%) compared with control (56.6+/-2.2%). Hypo-osmotic stress also produced protection similar to IP. IAA-94 or NPPB abolished the protection of both IP and hypo-osmotic stress. In buffer-perfused rabbit hearts preconditioned with three 5-minute ischemia/10-minute reperfusion cycles given before the 40-minute long ischemia and 60-minute reperfusion, IP significantly (P<0.0001) reduced infarct size (IP+vehicle, 4.7+/-0.9%, versus control+vehicle, 26.6+/-3.3%; mean+/-SEM). Again, IAA-94 or NPPB abolished the protection of IP. Our results implicate Cl- channels in the IP protection of the myocardium against ischemic/reperfusion injury and demonstrate that hypo-osmotic stress is capable of preconditioning cardiomyocytes.
Assuntos
Canais de Cloreto/antagonistas & inibidores , Precondicionamento Isquêmico Miocárdico , Isquemia Miocárdica/metabolismo , Miocárdio/química , Alcaloides , Animais , Benzofenantridinas , Células Cultivadas , Canais de Cloreto/fisiologia , Eletrofisiologia , Inibidores Enzimáticos/farmacologia , Ventrículos do Coração/química , Ventrículos do Coração/citologia , Ventrículos do Coração/patologia , Soluções Hipotônicas , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Fibras Musculares Esqueléticas/química , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/fisiologia , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miocárdio/citologia , Miocárdio/patologia , Necrose , Pressão Osmótica , Perfusão , Fenantridinas/farmacologia , CoelhosRESUMO
1. The activity of Ca2+ channels is regulated by a number of mechanisms including direct allosteric modulation by intracellular ATP. Since ATP derived from glycolysis is preferentially used for membrane function, we hypothesized that glycolytic ATP also preferentially regulates cardiac L-type Ca2+ channels. 2. To test this hypothesis, peak L-type Ca2+ currents (ICa) were measured in voltage-clamped rabbit cardiomyocytes during glycolytic inhibition (2-deoxyglucose + pyruvate), oxidative inhibition (cyanide + glucose) or both (full metabolic inhibition; FMI). 3. A 10 min period of FMI resulted in a 40.0 % decrease in peak ICa at +10 mV (-5.1 +/- 0.6 versus -3.1 +/- 0.4 pA pF-1; n = 5, P < 0.01). Similar decreases in peak ICa were observed during glycolytic inhibition using 2-deoxyglucose (-6.2 +/- 0.2 versus -3.7 +/- 0.2 pA pF-1; n = 5, P < 0.01) or iodoacetamide (-6.7 +/- 0.3 versus -3.7 +/- 0.2 pA pF-1; n = 7, P < 0.01), but not following oxidative inhibition (-6.2 +/- 0.4 versus -6.4 +/- 0.3 pA pF-1; n = 5, n.s.). The reduction in ICa following glycolytic inhibition was not mediated by phosphate sequestration by 2-deoxyglucose or changes in intracellular pH. 4. Reductions in ICa were still observed when inorganic phosphate and creatine were included in the pipette, confirming a critical role for glycolysis in ICa regulation. 5. With 5 mM MgATP in the pipette during FMI, peak ICa decreased by only 18.4 % (-6.8 +/- 0.6 versus -5.5 +/- 0.3 pA pF-1; n = 4, P < 0.05), while inclusion of 5 mM MgAMP-PCP (beta,gamma-methyleneadenosine 5'-triphosphate, Mg2+ salt) completely prevented the decrease in peak ICa (-6.9 +/- 0.3 versus -6.5 +/- 0.3 pA pF-1; n = 5, n.s.). 6. Together, these results suggest that ICa is regulated by intracellular ATP derived from glycolysis and does not require hydrolysis of ATP. This regulation is expected to be energy conserving during periods of metabolic stress and myocardial ischaemia.
Assuntos
Trifosfato de Adenosina/metabolismo , Canais de Cálcio/fisiologia , Glicólise/fisiologia , Coração/fisiologia , Regulação Alostérica , Animais , Canais de Cálcio/efeitos dos fármacos , Canais de Cálcio Tipo L , Cianetos/farmacologia , Desoxiglucose/farmacologia , Glucose/farmacologia , Glibureto/farmacologia , Glicólise/efeitos dos fármacos , Coração/efeitos dos fármacos , Ventrículos do Coração , Homeostase , Técnicas In Vitro , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Miocárdio/metabolismo , Ácido Pirúvico/farmacologia , CoelhosRESUMO
BACKGROUND: We compared ischemic preconditioning (IP) induced with a single cycle of transient ischemia and reperfusion with that induced by multiple cycles in terms of (1) efficacy of protection against myocardial necrosis and (2) susceptibility to pharmacological blockade by inhibition of protein kinase C (PKC) or elevation of cAMP. METHODS AND RESULTS: All rabbits were subjected to 30 minutes of regional ischemia and 90 minutes of reperfusion in vivo. IP was induced with either one or three cycles of 5-minute transient ischemia and 10-minute reperfusion given before the 30-minute ischemia. Drug-treated hearts received a bolus dose of one of the following just before the 30-minute ischemia: (1) the PKC inhibitor chelerythrine (3.8 mg/kg), (2) the PKC inhibitor polymyxin B (10 mg/kg), or (3) the cAMP-increasing agent NKH477 (45 microg/kg). IP induced with either one or three cycles of transient ischemia and reperfusion significantly protected the heart against infarction, although the extent of protection was significantly greater with three-cycle IP. Chelerythrine, polymyxin B, or NKH477 alone did not alter infarct size in control hearts, nor did they increase infarct size in hearts preconditioned with three-cycle IP. In contrast, when IP was induced with only a single cycle, all three of these drugs significantly increased infarct size above that of the untreated one-cycle IP group. However, infarct size in all three of these drug-treated one-cycle IP groups was still significantly lower than that in the corresponding drug-treated controls, indicating a partial block of IP. CONCLUSIONS: Three-cycle IP provided more effective protection against myocardial necrosis than one-cycle IP and was less susceptible to blockade by inhibitors of PKC or an agent that increases cAMP levels. However, single-cycle IP was only partially blocked by either inhibition of PKC or stimulation of cAMP production. Neither activation of the PKC pathway nor reduced formation of cAMP alone fully accounted for the necrosis protection by IP even when induced with only a single cycle of transient ischemia.
Assuntos
Coração/fisiopatologia , Precondicionamento Isquêmico/métodos , Adenilil Ciclases/metabolismo , Animais , Esquema de Medicação , Ativação Enzimática , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Feminino , Hemodinâmica , Masculino , Miocárdio/enzimologia , Miocárdio/patologia , Necrose , Proteína Quinase C/antagonistas & inibidores , CoelhosRESUMO
The aim of the present study was to assess the participation of angiotensin II receptors in the triggering mechanism of ischemic preconditioning. Isolated buffer-perfused rabbit hearts were subjected to 40 min of regional ischemia (37 degrees C) followed by 60 min of reperfusion. Ischemic preconditioning was induced with three cycles of 5-min ischemia and 10-min reperfusion given prior to the 40-min ischemic period. Infarct size and ventricular function were assessed. Ischemic preconditioning reduced infarct size to 5.2 +/- 1.2% of the area at risk (mean +/- S.E.M., P<0.001) when compared to controls (26.4 +/- 3.0%), but did not protect against ventricular dysfunction. Activation of angiotensin II receptors with angiotensin II (100 nM) also limited infarct size (9.6 +/- 2.2%, PAssuntos
Antagonistas de Receptores de Angiotensina
, Precondicionamento Isquêmico Miocárdico
, Infarto do Miocárdio/patologia
, Sistema Renina-Angiotensina/efeitos dos fármacos
, Disfunção Ventricular Esquerda/prevenção & controle
, Análise de Variância
, Animais
, Compostos de Bifenilo/uso terapêutico
, Circulação Coronária/efeitos dos fármacos
, Avaliação Pré-Clínica de Medicamentos
, Feminino
, Imidazóis/uso terapêutico
, Técnicas In Vitro
, Losartan
, Masculino
, Reperfusão Miocárdica
, Coelhos
, Saralasina/uso terapêutico
, Tetrazóis/uso terapêutico
RESUMO
The purpose of this study is to analyze the seasonality of the psychiatric emergencies visited in a casualty department, prospectively, during twelve consecutive months. The data were obtained with a record card containing clinics, sociodemographics, and related to consulting moment variables. During the months comprised between June to September, the results showed a general increase on the majority diagnostics and/or syndromics consulting reasons, with mention special to affective disorders. The increase showed in these entities could be related with the summer increase in Avila population. Because of these reason, these results, over all, those referred to July and August, should be interpreted with caution. These and other considerations are commented on the discussion.
Assuntos
Serviços de Emergência Psiquiátrica , Transtornos Mentais/epidemiologia , Estações do Ano , Adulto , Idoso , Feminino , Hospitais Gerais , Humanos , Incidência , Masculino , Transtornos Mentais/diagnóstico , Pessoa de Meia-Idade , Escalas de Graduação PsiquiátricaRESUMO
By marking cells of early gastrula stage embryos, we showed that in embryos mutant for a strong tll allele the fate map is shifted posteriorly and the hindgut anlage is deleted. We therefore used aspects of hindgut development to characterize the phenotype of new and previously described tll alleles. In embryos mutant for the various alleles, relative levels of blastoderm expression of Trg (T-related gene, required to establish the hindgut) and of mature hindgut size were determined; the results of these assays correlated with each other. Of the alleles that map to the sequence encoding the Tailless nuclear receptor protein, all (four) affect the zinc fingers of the DNA binding domain; surprisingly, substitutions of highly conserved residues allow a range of activities as detected by our bioassays.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Proteínas de Drosophila , Drosophila melanogaster/genética , Gástrula/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Intestinos/embriologia , Proteínas Repressoras/fisiologia , Alelos , Sequência de Aminoácidos , Animais , Sítios de Ligação , Blastoderma/metabolismo , Linhagem da Célula , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/genética , Drosophila melanogaster/embriologia , Embrião não Mamífero/metabolismo , Embrião não Mamífero/ultraestrutura , Gástrula/citologia , Genes de Insetos , Genes Letais , Mucosa Intestinal/metabolismo , Dados de Sequência Molecular , Fenótipo , Mutação Puntual , Proteínas Repressoras/genética , Deleção de Sequência , Dedos de Zinco/genética , Dedos de Zinco/fisiologiaRESUMO
Reduction of cAMP has been implicated in the protection of ischemic preconditioning (IP), but until now, this possibility has not been directly addressed. In this study, we found that in the in vivo rabbit heart 10 to 30 minutes of sustained regional ischemia was accompanied by a nearly twofold rise in cAMP levels. This increase in cAMP was attenuated when sustained ischemia was preceded by IP induced with a single cycle of transient ischemia and reperfusion (TI/R) and prevented when ischemia was preceded by three cycles of TI/R. The mechanism of cAMP reduction by IP does not involve activation of protein kinase C (PKC), since the PKC inhibitor polymyxin B (24 mg/kg) did not raise cAMP levels during sustained ischemia in IP hearts. Furthermore, this effect is also not mediated by reduced responsiveness of the beta-adrenergic effector pathway, since both nonischemic hearts and hearts subjected to three cycles of TI/R exhibited similar increases in cAMP in response to 5 micrograms/kg isoproterenol. However, propranolol (0.75 mg/kg) abolished the rise in cAMP levels observed during sustained ischemia in control hearts but did not reduce cAMP levels further in IP hearts. These data indicate that the ischemia-induced rise in cAMP levels in control hearts was mediated by activation of the beta-adrenergic receptor. Taken together with data demonstrating that beta-adrenergic responsiveness was not affected by IP, these data support the conclusion that the lack of elevation in cAMP levels observed during sustained ischemia in IP hearts is mediated by an attenuation of norepinephrine release. To examine whether the protection of IP against necrosis was mediated by the lack of elevation in cAmp levels, we determined whether the infarct size-limiting effect of IP could be blocked by NKH477, an activator of adenylyl cyclase. Four groups or rabbits were subjected to 30 minutes of in vivo regional ischemia and 90 minutes of reperfusion. Control hearts (n = 10) had 53.6 +/- 5.5% infarction of the area at risk. IP with three cycles of transient ischemia limited infarct size to 3.2 +/- 1.3% (N = 13, p < .0001). NKH477 (45 micrograms/kg) increased average cAMP levels in IP hearts during sustained ischemia to levels similar to those in untreated control hearts. However, NKH477 did not block IP (50.2 +/- 7.7% of the area at risk was infarcted in the control +NKH477 group [n = 10] versus 10.0 +/- 5.9% in the IP + NKH477 group [n = 7], P < .05). Therefore, we conclude that although IP lowers cAMP levels during sustained ischemia, this effect is not necessary for its protection against necrosis, since raising cAMP does not block this protection of IP.
Assuntos
AMP Cíclico/metabolismo , Isquemia Miocárdica/metabolismo , Adenilil Ciclases/metabolismo , Animais , Colforsina/análogos & derivados , Colforsina/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Hemodinâmica/efeitos dos fármacos , Masculino , Isquemia Miocárdica/fisiopatologia , Polimixinas/farmacologia , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Coelhos , Vasodilatadores/farmacologiaRESUMO
Tyrosine phosphorylation is an early, critical event in lymphocyte signal transduction. We measured tyrosine phosphorylation in a porcine experimental transplant model to evaluate its utility in monitoring the allograft immune response. Using flow cytometry, we demonstrate a biphasic increase in phosphotyrosine (ptyr) levels in peripheral blood mononuclear cells (PBMC), and that increases are detectable as early as 1 day posttransplantation in untreated transplanted animals (n = 4). This biphasic response is likely result from the sequestration of ptyr+ cells from the periphery into the graft as graft-infiltrating lymphocytic cells show increased ptyr levels. This suggests possible lymphocyte trafficking between the peripheral compartment and the allograft. A 5-day course of treatment with cyclosporine (CsA) at 20 mg/kg/day (n = 4), but not at 10 mg/kg/day (n = 4), prevents graft rejection in this allograft model. Strikingly, treatment with 20 mg/kg/day CsA, but not with 10 mg/kg/day, suppressed increases in ptyr levels in both PBMC and graft-infiltrating cells. Increases in ptyr levels in PBMC are detectable 2-5 days before histologic and electrocardiographic signs of graft rejection, suggesting a potential diagnostic utility for measuring tyrosine phosphorylation in monitoring and managing transplant rejection.
Assuntos
Ciclosporina/uso terapêutico , Rejeição de Enxerto/diagnóstico , Transplante de Coração , Linfócitos/metabolismo , Tirosina/metabolismo , Animais , Biomarcadores , Citometria de Fluxo , Rejeição de Enxerto/prevenção & controle , Técnicas Imunoenzimáticas , Imunofenotipagem , Miocárdio/metabolismo , Fosforilação , Fosfotirosina , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Transdução de Sinais , Suínos , Transplante Homólogo , Tirosina/análogos & derivados , Tirosina/análiseRESUMO
OBJECTIVE: The aim was to compare the effects of ischaemic preconditioning in the buffer perfused and parabiotic blood perfused Langendorff rabbit heart models. METHODS: Isolated hearts were perfused with either Krebs-Henseleit buffer solution or blood from a support rabbit. Hearts were subjected to an initial 30 min stabilisation period followed by 30 min of global ischaemia and 60 min of reperfusion. Ischaemic preconditioned (IP) hearts were also subjected to one cycle of 5 min global ischaemia and 10 min of reperfusion before the 30 min ischaemia. For each experiment, left ventricular function and necrosis were measured. RESULTS: Necrosis, as measured by tetrazolium staining and expressed as a percentage of the left ventricular area, was significantly different between the buffer perfused control [42.5% (SEM 6.9), n = 7] and buffer perfused IP group [22.2% (5.4), n = 7, p < 0.01]. In the blood perfused experiments, the IP group also had less necrosis [9.3% (3.1), n = 9] as compared to controls [22.9%(4.2), n = 9, p < 0.01]. The percentage reduction in necrosis produced by ischaemic preconditioning was not significantly different between the buffer perfused and blood perfused models. Peak left ventricular systolic pressure was not different between the control and IP hearts in either model at any time during the 60 min reperfusion period. In buffer perfused hearts, left ventricular end diastolic pressure at 60 min reperfusion was not significantly different between the IP and the control groups, at 34.3(5.5) mm Hg v 37.8(4.9) mm Hg, respectively. Similarly, there was no statistically significant difference in left ventricular end diastolic pressure in the blood perfused groups at this time: 13.3(2.8) in the IP group v 24.0(6.5) in controls. CONCLUSIONS: In isolated heart models of global ischaemia and reperfusion, in which both recovery of function and necrosis were assessed together, ischaemic preconditioning was highly effective in reducing necrosis in both blood perfused and buffer perfused models. However, ischaemic preconditioning did not significantly improve postischaemic recovery of function in either of the two preparations.
Assuntos
Coração/fisiopatologia , Infarto do Miocárdio/prevenção & controle , Isquemia Miocárdica , Reperfusão Miocárdica/métodos , Animais , Pressão Sanguínea/fisiologia , Soluções Tampão , Feminino , Masculino , Infarto do Miocárdio/patologia , Isquemia Miocárdica/patologia , Isquemia Miocárdica/fisiopatologia , Miocárdio/patologia , Perfusão , CoelhosRESUMO
Increased biocompatibility and lower cost are the two major arguments favoring routine dialyzer reprocessing. The impact of longer-term reprocessing is critical to the practical use of polysulfone membranes (PMs), because of the possibility of decreasing efficiency and performance, especially in the removal of beta 2-microglobulin (beta 2M), a protein that has been implicated in the development of dialysis-associated amyloidosis (DDA). In this study, we examine urea clearance (Kd), urea mass transfer coefficient (h0), ultrafiltration coefficient (K(uf)), and percent removal of beta 2M up to 24 uses. The study involved 11 patients on hemodialysis for 5.27 +/- 4.6 years, with a mean age of 62.5 +/- 9.7 years and average run-time treatment of 2.78 +/- 0.3 hours. PMs were tested after being reprocessed manually using bleach and formaldehyde. The efficacy of the dialyzer was examined on uses 1, 5, 10, 15, 20, and 24, and the percent removal of beta 2M was determined except in the twentieth use and corrected for ultrafiltration. The Kd obtained through 24 uses showed no significant change, although h0 was significantly increased in the fifteenth use, and K(uf) was significantly increased in the 10th and 20th use (P < 0.05). The percent removal of beta 2M increased significantly from 44.1 +/- 2.8 (mean +/- SEM) in the first use to 59.4 +/- 2.19 (P < 0.05) in the 10th use, and 62.1 +/- 4.07 and 63.1 +/- 4.27 in the 15th and 24th uses, respectively (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Membranas Artificiais , Polímeros , Diálise Renal/instrumentação , Sulfonas , Microglobulina beta-2/isolamento & purificação , Adulto , Idoso , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Matemática , Pessoa de Meia-Idade , Análise de RegressãoRESUMO
Neonates undergoing heart surgery are exposed to high levels of circulating catecholamines. Our objective was to determine to what extent administration of magnesium counters epinephrine-induced cardiotoxicity. We assessed left ventricular function (pressure-volume data obtained by the conductance catheter/micromanometer technique) and ultrastructure in newborn pigs 3 to 5 days of age before and after administration of epinephrine alone (2 micrograms/kg/min, group A, n = 6) and simultaneously with magnesium sulfate (8 mmol/L, 5 ml/hr, group B, n = 6). Plasma levels of magnesium were maintained at 200% to 250% of control, and ionized calcium was maintained at normal levels. During administration of epinephrine, there was a significant increase in end-systolic elastance from 8.9 +/- 2 to 15 +/- 3 mm Hg/ml in group A and from 7.8 +/- 2 to 16 +/- 3 mm Hg/ml in group B (p < 0.05). This increase was accompanied by an increase in chamber stiffness index (p < 0.05) and shortening of the time constant of isovolumic relaxation (p < 0.05; group A, 19 +/- 3 to 13 +/- 3 msec; Group B, 20 +/- 2 to 15 +/- 2 msec). After epinephrine was discontinued, however, systolic and diastolic indexes returned to baseline levels in group B, whereas group A exhibited a significant reduction in end-systolic elastance (5 +/- 1 mm Hg/ml; p < 0.05) and an increase in chamber stiffness index (0.7 +/- 0.08 versus 0.4 +/- 0.1 ml-1; p < 0.05) and time constant (25 +/- 1 versus 19 +/- 3 msec). Left ventricular dysfunction in group A was associated with focal sarcolemmal rupture and mitochondrial swelling, whereas only minor reversible changes (microvesicular lipid accumulation) were seen in group B. We conclude that magnesium has a protective effect against epinephrine-induced cardiotoxicity because of its blocking action on calcium influx of ionized calcium and could be of therapeutic benefit in the perioperative period.
Assuntos
Epinefrina/farmacologia , Cardiopatias/induzido quimicamente , Coração/efeitos dos fármacos , Magnésio/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Animais Recém-Nascidos , Diástole , Coração/fisiopatologia , Frequência Cardíaca , Miocárdio/metabolismo , Miocárdio/ultraestrutura , Suínos , Sístole , Função Ventricular EsquerdaRESUMO
This study is designed to test the hypothesis that specific morphologic attributes of peripheral blood mononuclear cells, measurable by flow cytometry, are correlated with the timing and the intensity of allograft injury during the development of heart rejection. A pig model of major histocompatibility complex-mismatched heterotopic heart transplantation with (n = 5) and without (n = 5) cyclosporine administration was monitored serially be telemetered electrocardiography and endomyocardial biopsies. Flow cytometric analysis of peripheral blood mononuclear cells revealed the emergence of a discrete subpopulation of peripheral blood mononuclear cells (7.8% +/- 1.0% and 8.5% +/- 0.9% before transplantation to 16.5% +/- 1.3% and 19.4% +/- 3.0% after transplantation in the untreated and the cyclosporine-treated groups, respectively, p < 0.05), exhibiting characteristic changes in forward and 90-degree light scatter, indicative of increased cell size and granularity, and possibly representing monocytes or large granular lymphocytes. Lymphocyte cell surface-marker studies indicated that 62% of these cells are DH59B+ (monocyte/granulocyte). Because intracellular free calcium is an important second messenger in lymphocyte activation we measured intracellular free calcium by flow cytometry using fluo-3. This subpopulation of cells was found to have similar intracellular free calcium when compared to normal-sized lymphocytes (104 +/- 7 nmol/L versus 101 +/- 5 nmol/L, respectively). We conclude that this lymphocyte subset detected by flow cytometry represents specifically reactive cells that are associated with incipient allograft rejection.
Assuntos
Rejeição de Enxerto/patologia , Transplante de Coração , Leucócitos Mononucleares/ultraestrutura , Miocárdio/patologia , Animais , Biópsia , Cálcio/metabolismo , Ciclosporina/uso terapêutico , Eletrocardiografia , Citometria de Fluxo , Subpopulações de Linfócitos , Miocárdio/metabolismo , Suínos , Transplante HeterotópicoRESUMO
We have followed prospectively, 46 obese, type 2 diabetic patients for a 55-week period, in order to evaluate the efficiency of an educational programme based on behaviour modification to enhance weight loss and changes of other cardiovascular risk factors. No patient received pharmacological treatment during the study. At the end of the follow-up the patients obtained an average weight loss of 9.250 kg (range: 0.500-17.500 kg); the BMI was reduced from 34.2 +/- 0.8 kg/m2 to 30.6 +/- 1.1 kg/m2 (P less than 0.01); fasting serum glucose descended from 7.9 +/- 0.4 to 6.1 +/- 0.5 mM (P less than 0.05); SBP (systolic blood pressure) decreased from 145.7 +/- 3 to 126.4 +/- 5.1 mmHg (P less than 0.01); DBP (diastolic blood pressure) decreased from 83.5 +/- 2.5 to 65 +/- 2.6 mmHg (P less than 0.01); triglyceride levels were lowered from 164.5 +/- 12 to 109.7 +/- 10 mg/dl (P less than 0.01); HDL-cholesterol levels increased from 1.27 +/- 0.05 to 1.53 +/- 0.12 mM (P less than 0.01). Serum glucose 2 h after a 75 g glucose oral load decreased from 14.9 +/- 0.6 to 12.7 +/- 0.9 mM (P less than 0.05) on week 35 of follow-up. Twelve patients no longer presented a diabetic curve (8 normal oral glucose tolerance test (OGTT) curves, and 4 impaired glucose tolerance (IGT) curves). No significant changes in the parameters studied were obtained in the group of patients on conventional treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Terapia Comportamental , Diabetes Mellitus Tipo 2/psicologia , Diabetes Mellitus/psicologia , Obesidade , Educação de Pacientes como Assunto , Redução de Peso , Glicemia/metabolismo , Índice de Massa Corporal , Peso Corporal , Colesterol/sangue , HDL-Colesterol/sangue , Diabetes Mellitus/fisiopatologia , Diabetes Mellitus/terapia , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/terapia , Dieta para Diabéticos , Feminino , Seguimentos , Humanos , MMPI , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Triglicerídeos/sangueRESUMO
The disposition kinetics of cyclosporin A in the neonates as well as age-related differences in lymphocyte responses to cyclosporin A are unknown. A single intravenous infusion of cyclosporin A was given to neonatal (2.5 or 5 mg/kg) and mature pigs (10 mg/kg) and blood cyclosporin A levels were measured by RIA. The neonates had longer elimination half-life and lower drug clearance than mature animals. Suppression in lymphocyte proliferation was only observed in mixed lymphocyte reaction and phytohemagglutinin-stimulated cultures of the 2-hour samples from neonates receiving 5 mg/kg. We conclude that neonatal pig exhibit different cyclosporin A pharmacokinetics and show higher sensitivity to cyclosporin A than mature animals.