The effect of hemodialysis on the body composition and cardiovascular disease markers in recently diagnosed end stage renal disease patients

SUMMARY AIM: Uremic toxins and excess fluid contributes to increased cardiovascular (CV) risk. We aimed to determine the body fluid status in patients who are just starting hemodialysis (HD) and to determine the effects of excess fluid removed by HD on the CV system. METHODS: A total of 52 patients with chronic kidney disease (CKD) who had just started HD were included. Before the HD, the left atrial diameter was measured, the volumes were calculated, the pulse wave velocity (PWV) and the augmentation index (AIx) were measured, the bioimpedance analysis (BIA) was performed, the blood was taken for brain natriuretic peptide (BNP). When patients reached their dry weight with HD, the same measurements were repeated. RESULTS: Measurements were made to determine the volume status, and all parameters except the fat tissue index decreased significantly after HD. With the removal of fluid by HD, there was an average weight reduction of 4.38 kilograms. Positive correlations between PWV and age and cardiothoracic ratio (CTR) before HD were determined. Negative correlations were found between PWV and lean tissue mass (LTM) and intracellular water (ICW) before HD. At the end of the last HD, PWV was positively correlated with age, CTR, central pulse pressure Correlation between pulse wave velocity and LTI was negative CONCLUSIONS: HD significantly improves PWV in patients reaching dry weight. Reduction of fluid excess by ultrafiltration in HD patients may reduce CV mortality by reducing arterial stiffness.

RESUMO INTRODUÇÃO: Em pacientes com doença renal crônica (DRC), toxinas urêmicas e hipervolemia contribuem para aumentar o risco cardiovascular. Nosso objetivo foi determinar o estado de hidratação em pacientes com DRC iniciando hemodiálise (HD) e avaliar os efeitos da correção da hipervolemia sobre o sistema cardiovascular. MÉTODOS: Foram incluídos 52 pacientes que haviam acabado de iniciar HD. Antes do início da sessão, foram determinados o diâmetro e o volume atrial esquerdo, a velocidade de onda de pulso (VOP) e o índice de amplificação sistólica ("augmentation index", AI). Além disso, realizamos análise da composição corporal por bioimpedância elétrica (BIA) e mensuramos os níveis plasmáticos de peptídeo natriurético tipo B. Os mesmos procedimentos foram repetidos após os pacientes alcançarem o "peso seco". RESULTADOS: O peso corporal dos pacientes foi reduzido, em média, em 4,38 kg. Na BIA, todos os parâmetros, exceto o índice de gordura corporal, foram significativamente reduzidos após a hemodiálise. Antes da HD, a VOP se correlacionou positivamente com idade e razão cardiotorácica (RCT), e negativamente com a massa magra e a água intracelular. Ao final da hemodiálise, a VOP se correlacionou positivamente com idade, RCTe pressão de pulso central, correlacionando-se negativamente com a Lean Tissue Index (LTI). CONCLUSÃO: A hemodiálise melhora a VOP por meio da redução da volemia. O controle da hipervolemia via ultrafiltração pode reduzir a mortalidade cardiovascular por meio da redução da rigidez arterial.

Correlation between predialysis systolic blood pressure and predialysis hydration status in hemodialysis patients / Correlación entre la presión arterial sistólica prediálisis y el estado de hidratación prediálisis en pacientes de hemodiálisis

One of the goals of hemodialysis is to maintain normal hydration status in ESRD patients.Pre hemodialysis systolic blood pressure is usually used as a clinical parameter of hydration status and to set ultrafiltration rate before Hd. It is unclear how much pre-Hd SBP correlated with hydration status. The aimwas to determine correlation between pre-Hd SBP and hydration status before Hd. An observational correlation study was performed in two dialysis centers in Santiago, Chile, from January-June, 2011. Adult patients inHd for at least three months, who gave their informed consent were included. Patients with pacemaker,amputee, hospitalized and metallic prostheses were excluded. Total-body water and over hydrated were assessed with bioimpedance spectroscopy before the first and third dialysis session of the week. Pre-Hd SBP,pre-Hd body weight, pre-Hd TBW and pre-Hd OH, were analyzed using Pearson correlation and linear regressionmodel. 96 measurements were assessed, 52 % were male with median age 59.5 years. The correlationbetween pre-Hd SBP and pre-Hd overhydration was r=0.33, and total body water r=0.15, with a predictedvalue, R2=0.10 and R2 =0.14 respectively. Pre-Hd SBP had low correlation with pre-Hd hydration status and by itself, is not a reliable parameter to set ultrafiltration rate before Hd. Nevertheless Pre-Hd body weight predicted in 70 % the pre-Hd TBW.

Uno de los objetivos de la hemodiálisis es mantener la hidratación normal en pacientes ESRD. La presión arterial sistólica pre hemodiálisis, es usualmente utilizada como parámetro clínico del estado de hidratación y para fijar la velocidad de ultrafiltración antes de la hemodialisis. No está claro cuanto se correlacionan la presión arterial sistólica prehemodialysis con el estado de hidratación. El objetivo fue determinar la correlación entre la PAS prehemodiálisis y el estado de hidratación antes de Hd. Se realizó un estudio de correlación observacional en dos centros de diálisis de Santiago de Chile, de Enero a Junio de 2011. Se incluyeron pacientes adultos en HD durante al me-nos tres meses que dieran su consentimiento informado. Se excluyeron los pacientes con marcapasos, amputados, hospitalizados y pró-tesis metálicas. El agua corporal total y el exceso de hidratación se evaluaron con espectroscopia 1030 de bioimpedancia antes de la primera y tercera sesión de diálisis de la semana. Pre-Hd PAS, pre-Hd peso corporal, pre-Hd ACT y pre-Hd OH, se analizaron utilizando el modelo de correlación y regresión lineal de Pearson. Se evaluaron 96 mediciones, 52% eran hombres con edad media 59, 5 años. La correlación entre la PAS pre-Hd y la sobrehidratación pre-Hd fue r=0, 33 y agua corporal total r=0, 15, con un valor predicho, R2= 0, 10 y R2 = 0, 14 respectivamente. Existe baja correlación entre la PAS Pre-Hd con el esta-do de hidratación pre-Hd y por lo mismo, no es un parámetro confiable para establecer la tasa de ultrafiltración antes de Hd. Sin embargo, el peso corporal Pre-Hd predijo en un 70% el agua corporal total pre-Hd.

Role of α2-adrenoceptors in the lateral parabrachial nucleus in the control of body fluid homeostasis

Central α2-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α2-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α2-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α2-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α2-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion.

Mapping and signaling of neural pathways involved in the regulation of hydromineral homeostasis

Several forebrain and brainstem neurochemical circuitries interact with peripheral neural and humoral signals to collaboratively maintain both the volume and osmolality of extracellular fluids. Although much progress has been made over the past decades in the understanding of complex mechanisms underlying neuroendocrine control of hydromineral homeostasis, several issues still remain to be clarified. The use of techniques such as molecular biology, neuronal tracing, electrophysiology, immunohistochemistry, and microinfusions has significantly improved our ability to identify neuronal phenotypes and their signals, including those related to neuron-glia interactions. Accordingly, neurons have been shown to produce and release a large number of chemical mediators (neurotransmitters, neurohormones and neuromodulators) into the interstitial space, which include not only classic neurotransmitters, such as acetylcholine, amines (noradrenaline, serotonin) and amino acids (glutamate, GABA), but also gaseous (nitric oxide, carbon monoxide and hydrogen sulfide) and lipid-derived (endocannabinoids) mediators. This efferent response, initiated within the neuronal environment, recruits several peripheral effectors, such as hormones (glucocorticoids, angiotensin II, estrogen), which in turn modulate central nervous system responsiveness to systemic challenges. Therefore, in this review, we shall evaluate in an integrated manner the physiological control of body fluid homeostasis from the molecular aspects to the systemic and integrated responses.

Central actions of glucocorticoids in the control of body fluid homeostasis: review

The involvement of the hypothalamic-pituitary-adrenal axis in the control of body fluid homeostasis has been extensively investigated in the past few years. In the present study, we reviewed the recent results obtained using different approaches to investigate the effects of glucocorticoids on the mechanisms of oxytocin and vasopressin synthesis and secretion in response to acute and chronic plasma volume and osmolality changes. The data presented here suggest that glucocorticoids are not only involved in the mechanisms underlying the fast release but also in the transcriptional events that lead to decreased synthesis and secretion of these neuropeptides, particularly oxytocin, under diverse experimental conditions of altered fluid volume and tonicity. The endocannabinoid system, through its effects on glutamatergic neurotransmission within the hypothalamus and the nuclear factor κB-mediated transcriptional activity, seems to be also involved in the specific mechanisms by which glucocorticoids exert their central effects on neurohypophyseal hormone synthesis and secretion.

[Theoretical and numerical modeling of flow problems of non Newtonian fluids through deformable tubes]

The objective of the present work is a numerous simulation of blood flow considered with a two-fluid model [Newtonian fluid-Casson generalized fluid] through deformable tubes. The porosity, anisotropy, axial and radial deplacement of the pipe are considered. Using an implicit finite differences method to solve the equations systems local, integral and the duct, the global and the local quantities for the flow were determined. This study considered as a step in the modelling of flow in blood vessels, may also contribute to other important fields such as water desalination or gel filtration

Role of the doppler echocardiography in assessment of fluid status in chronic haemodialysis patients

The aim of this study is to examine the role of the Doppler echocardiographic parameters in the assessment of fluid status in these patients with chronic haemodialysis. Sixty subjects were included in this study. Group I Included 20 patients who had been on chronic haemodialysis 6 months at least and were normotensive without receiving anti-hypertensive agents.Group II: included 20 patients on chronic haemodialysis 6 months at least and remained hypertensive under anti-hypertensive agents. Group III: Included 20 subjects who are apparently normal without history of cardiac disease [con trol group]. The S/D [peak pulmonary vein systolic velocity [s] divided by peak pulmonary vein diastolic vlocity [D]] was significantly higher in group I [mean +/- SD = 1.886 +/- 0.214]. Then in group II [mean +/- SD = 1.123 +/- 0.169] with p-value <0.001. S/D ratio can be used as a good tool to assess the fluid status in chronic haemodialysis patients specially if combined with others as inferior vena cava diameter

Considerações fisiológicas na fluidoterapia de cães e gatos / Physiological Considerations on Fluid Therapy of Dogs and Cats / Consideraciones fisiologicas en la fluidoterapia en perros y gatos

A desidratação é um distúrbio comum na prática veterinária e está associada a inúmeras doenças. Seu reconhecimento é fácil, e seu tratamento, embora pareça simples, requer boa dose de critério. O emprego correto da fluidoterapia depende da escolha do fluido de acordo com o tipo de desidratação e causas relacionadas. O conhecimento da fisiologia dos líquidos corporais e da farmacologia das soluções empregadas é o que realmente garante o sucesso da fluidoterapia.

ABSTRACT: Dehidration is a common disorder in veterinary practice, and is associated with inumerous diseases. The dehydration recognition is easy and the treatment, besides simple, calls for good dose of criterion. The correct utilization of fl uid therapy depends of fl uid's choice, type of dehydration associated and related causes. The knowledge of body fl uids physiology and the pharmacology of used solutions may garantee the success of fl uid therapy.

RESUMEN: Deshidratación es una desorden común en la práctica veterinaria, y se encuentra asociada a innumeras enfermedades. Su reconocimiento es fácil, y su tratamiento, aunque sensillo, demanda buena porción de criterio. El empleo correcto de la fl uidoterapia depiende de la selección del fl uido de acuerdo con el tipo de deshidratación y sus causas. El conocimiento de la fi siología de los fl uidos corporales y de la farmacología de las soluciones empleadas es lo que realmente salvaguarda el suceso de la fl uidoterapia

Análise bioquímica dos líquidos fetais e citologia do fluido amniótico da fêmea de Mocó (Kerodon rupestris) / Biochemical analysis of fetal fluids and cytology of the amniotic fluid of female Mocó (Kerodon rupestris)

Foram utilizados 10 sistemas genitais femininos de mocós (Kerodon rupestris) para estabelecer parâmetros de referência relativos à osmolaridade, pH, cálcio, fósforo, uréia, creatinina, glicose e proteínas totais. Os animais foram criados em cativeiro no CEMAS (Centro de Criação de Animais Silvestres), Mossoró - RN. As fêmeas estavam da metade (30-45 dias) para o final da gestação (65-70 dias). As bolsas amnióticas e alantoideanas foram puncionadas individualmente para colheita dos líquidos fetais, que foram centrifugados e analisados posteriormente. Para o líquido amniótico, as concentrações médias em mg/dl foram: glicose = 45,87 ± 22,38; cálcio = 6,31 ± 1,24; fósforo = 1,64 ± 0,72; creatinina = 0,45 ± 0,12; uréia = 34,03 ± 5,96; proteínas totais = 31,24 ± 16,67. Para o líquido alantoideano, as concentrações médias em mg/dl foram: glicose = 59,17 ± 10,85; cálcio = 5,58 ± 0,59; fósforo = 1,27 ± 0,73; creatinina = 0,38 ± 0,38; uréia = 31,49 ± 2,28; proteínas totais = 30,70 ± 18,39. Foram observadas pequenas oscilações entre as concentrações dos parâmetros bioquímicos do fluido amniótico e alantoideano. Estas concentrações são determinadas, provavelmente, pela atividade metabólica materno-fetal. A análise das células do fluido amniótico revelou quatro tipos celulares.

Estudio y cuantificación de la respuesta de la hiperhidrosis palmar y tratamiento con sales de aluminio micropulverizadas / Study and quantification of palmar hyperhidrosis response and treatment with micropulverized aluminum salts

La hiperhidrosis palmar primaria es una enfermedad social y estresante para el paciente, pudiendo tener importantes consecuencias en su autoestima y en sus relaciones interpersonales. Debido a esto, es importante contar con tratamientos que sean efectivos, seguros, sencillos y accesibles para cada paciente. Se necesitan métodos que midan el grado de hiperhidrosis palmar, permitiendo así el seguimiento objetivo de la respuesta clínica al tratamiento.

Pancreatic juice and duodenal fluid flow rate in cow calves from birth to early ruminant state.

The present investigation on pancreatic juice (PJ) and duodenal fluid (DF) was carried out in 10 crossbred (Jersey x Kankrej) male cow calves from birth to early ruminant state (15 week). The respective samples were measured in situ by cannulating the pancreatic duct and duodenal lumen, 30 minutes before feeding (BF) and 30 minutes after feeding (AF) both during morning (MH) and evening (EH). The results revealed significant increase in PJ and DF flow rate with age. Diurnal effect was nonsignificant except a significant increase recorded during EH on 4 d for PJ and 3 d for DF.

Melatonin, biological rhythm disorders and phototherapy.

Biological rhythms are endogenous in nature and are generated by self sustained oscillators present in the living organisms themselves. Of these, circadian rhythms are the most thoroughly studied and are driven by the suprachiasmatic (SCN) of hypothalamus. The recent discovery of high affinity melatonin receptors ML1, ML2 in SCN suggests that melatonin is involved in the control of circadian rhythm generation. The fact that biological rhythm disorders like delayed sleep phase syndrome (DSPS), Jet lag, shift-work disorders, seasonal effective disorder (SAD) respond well either to phototherapy or melatonin adds further support to the concept that melatonin is involved in the pathogenesis of these conditions. Indeed altered melatonin rhythms have bee documented in MDP, shift work disorder, endogenous depression etc. In addition to functioning as a rhythm regulator, melatonin is also involved in the control of sleep, regulation of body temperature, reproduction, and as a free radical scavanger and antioxidant protecting the cells and tissues of our body against oxidative damage. Low levels of melatonin in cancer patients and patients with coronary heart disease indicate that melatonin may be involved in these disorders also.

ANP as a neuroendocrine modulator of body fluid homeostasis

The role played by the central nervous system (CNS) in the control of body fluid homeostasis has been demonstrated by several authors. The AV3V plays a key role in central control of sodium excretion since its cholinergic, adrenergic, angiotensinergic and osmotic stimulation enhances and its destruction blocks sodium excretion in rats and goats. Cholinergic stimulation of the AV3V induced an increase in plasma ANP as well as a marked elevation in content of the peptide in medial basal hypothalamus, neuro and adenohypophysis. On the other hand, a decline in plasma ANP after AV3V lesions was accompanied by dramatic declines in content of ANP in these same structures. Our previous work has also indicated the essential role of the AV3V region and its ANPergic neurons in the control of ANP release in response to volume expansion (BVE) and indicated that alpha-adrenergic and muscarinic receptors are critical in mediating these responses. Lesions of the AV3V region, or of the median eminence or posterior lobe of pituitary gland blocked the increase in plasma ANP concentration in response to BVE. That this effect is related to blockage of the activity of the brain ANPergic neurons is supported by fyndings in sheep and in rats that the injection of the antiserum directed against ANP into the AV3V region at least partially blocked the BVE-induced release of ANP. We and others have also previously shown that denervation of baroreceptors inhibits ANP release induced by BVE. Activation of the ANP neurons also cause release of ANP from the anterior and neural lobe of pituitary gland. ANP neurons may activate oxytocinergic neurons in the supraoptic and paraventricular, which projects to neural lobe. Oxytocin would circulate to the atria and may directly activate release of ANP from the atrial myocytes, since i.v. or i.p. injection of oxytocin increases sodium excretion as well as elevates plasma ANP. Oxytoxin is present in the neural lobe in large quantity, which could reach the atria myocytes in high concentration and release ANP that circulate to the kidneys and evokes natriuresis to return circulating blood volume to normal.

Substitutos do plasma / Plasma substitutes

A preocupaçao constante com as complicaçoes advindas da transfusao indiscriminada de sangue, notadamente as doenças transmissíveis e também a falta de uma reserva sangüínea razoável para uma reposiçao emergencial, fizeram com que houvesse um grande impulso no sentido de se buscar uma soluçao alternativa para as perdas sangüíneas e plasmáticas. O objetivo do presente estudo é fazer uma revisao sobre as soluçoes em uso com esta finalidade, seus aspectos fisiopatológicos, complicaçoes e restriçoes ao seu emprego.

Atrial natriuretic peptide: pathophysiological considerations.

Atrial natriuretic peptide (ANP) is a cardiac hormone with potent diuretic and natriuretic properties. This hormone mediates a finely tuned control mechanism for the maintenance of blood pressure and volume. The altered pressure and volume in many important cardiovascular diseases suggest that understanding the functional role of ANP is integral to these conditions. ANP levels are increased in a wide variety of cardiac disorders such as hypertension, diabetes, congestive heart failure, myocardial infarction and valvular heart diseases. Several studies have indicated a positive correlation between the severity of cardiac disorders and plasma ANP levels highlighting its importance as a prognostic factor in cardiovascular diseases. Furthermore, its compensatory role in these situations has prompted a world-wide investigation on the use of ANP as a drug in cardiac diseases and it is not surprising that there has been a wealth of scientific papers on this subject. This review attempts to summarize the present knowledge concerning the physiology of ANP and evaluates some of the latest experimental findings and opinions on the involvement of ANP in cardiovascular diseases.

Papel dos átrios no controle dos fluidos corpóreos / Role of the atria in the control of body fluids

Na regulaçäo do volume líquido corpóreo, os átrios desempenham papel central. Desde os trabalhos de Henry, Gauer e Reeds, tem sido evidenciada, principalmente por técnicas de distençäo atrial, a existência de receptores de volume, preponderantes no átrio esquerdo, que reconheceriam a plenitude do volume sanguíneo. Quando este estivesse aumentado, esses receptores dariam origem a um reflexo neuro-humoral, em que a via aferente seria o nervo vago, o centro, o hipotálamo e a via eferente a inhibiçäo da secreçäo do hormônio antidiurético da hipófise (ADH), resultando disto menor reabsorçäo da água do filtrado glomerulae e consequente diurese. Esse mecanismo teria por vezes precedência a regulaçäo osmótica. Essas experiências, as quais se juntaram as investigaçöes dos AA, demonstraram também aumento na excreçäo do sódio e para isto postulava-se a liberaçäo em um local indeterminado de um fator natriurético. Em 1981, de Bold e cols. relatavam um hormônio produzido nos cardiócitos atriais (ANF), que seria liberado quando o átrio fosse distendido e, por mecanismos vários, atuaria no néfron, levando a profusa diurese e natriurese, o que desencadeou grande volume de investigaçöes, levando a determinaçäo da fórmula do peptídio responsável, sua síntese e criaçäo de vários fármacos derivados. As implicaçöes fisiológicas e fisiopatológicas desta descoberta, bem como as possibilidades terapêuticas do uso de derivados sintéticos do ANF, säo discutidas pelos autores