RESUMO
OBJECTIVE: Alternative sites to the liver for islet transplantation have been studied for a long time. Intramuscular islet transplantation appears to be an alternative site to the liver because of the ease of access. First islet autotransplantations were reported in patients after total pancreatectomies. The transplanted islets showed a proper revascularization and their function was observed for up to 2 years after the implant. However, only a few cases of autotransplantation and no allotransplantation have been performed. The aim of this study was to verify the feasibility of islet allotransplantation into muscles. PATIENTS AND METHODS: In four patients affected by type 1 diabetes mellitus in which liver islet allotransplantation was contraindicated, human islets were transplanted into patients' arm muscle with local anesthesia. RESULTS: The surgery was minimally invasive, without complications. In one patient a moderate local inflammatory reaction was observed at the site of the implant, which resolved spontaneously within 4 days. Islet graft function was observed after transplantation in all patients, but it progressively disappeared in 3 out 4 patients within a short time. CONCLUSIONS: In this first ever-reported intramuscular pancreatic islet allotransplantation, the procedure appears feasible but new strategies must be envisaged to significantly improve islet engraftment and the long-term graft function.
Assuntos
Diabetes Mellitus Tipo 1/cirurgia , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/cirurgia , Músculo Esquelético/cirurgia , Adulto , Animais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transplante Homólogo , Resultado do TratamentoRESUMO
INTRODUCTION: Robot-assisted kidney harvesting from living donors is feasible and safe. We report the results of a mono-centric experience relative to 98 consecutive robotic nephrectomies with emphasis on global donor complications. MATERIALS AND METHODS: This is a retrospective cohort study. Donors underwent robot-assisted kidney harvesting. The preferred kidney was the left one even in the presence of vascular anomalies. In the first cases we used a robotic hand-assisted technique, then the totally robotic technique, and finally the modified totally robot-assisted technique. Postoperative complications were ranked according to the five-grade Clavien-Dindo classification. RESULTS: Between November 2009 and November 2016, 98 living donors underwent nephrectomy. We experienced 14 complications. The 3 intraoperative ones (3.06%) were 1 pneumothorax and 2 acute bleedings, 1 of them requiring transfusion. The 11 postoperative complications (11.22%) were as follows: 5 wound seromas, 1 rhabdomyolisis (Clavien I), 1 paretic ileum, 1 anemia requiring transfusion, 1 hypertensive crisis (Clavien II), and 2 chylus collections drained by interventional radiologists (Clavien III). Transfusion rate was 2.1%; conversions, reoperations, and mortality were nil. No statistically significant difference was observed between the patients with complications and without in terms of gender, age, anatomical anomalies, body mass index (BMI), and learning curve. We observed a longer global operation length of time in patients with complications. CONCLUSION: Robotic assistance results in shorter and simpler learning curves for the harvesting of kidneys from living donors. It enables an easier and more efficient management of possible intraoperative complications. The rate of postoperative complications is comparable with the rate of complications encountered in traditional laparoscopic series with high numbers of harvestings.
Assuntos
Transplante de Rim/métodos , Doadores Vivos , Nefrectomia/métodos , Robótica/métodos , Coleta de Tecidos e Órgãos/métodos , Adulto , Idoso , Feminino , Humanos , Complicações Intraoperatórias/epidemiologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos RetrospectivosRESUMO
AIMS: To overview the effects of omega-3 polyunsaturated fatty acids (PUFA) on blood vessels and blood pressure (BP) and their relevance for cardiovascular prevention. DATA SYNTHESIS: The importance of omega-3 PUFA for the cardiovascular system has come under the spotlight during the last decades. These fatty acids are present in variable amounts in cell membranes of mammal species, and their content affects a variety of cellular functions. Evidence obtained in animal and human studies suggests that omega-3 PUFA affect many steps of the atherosclerotic process. In blood vessels, omega-3 PUFA improve endothelial function; promote vasodilatation through relaxation of smooth muscle cells; exert antioxidant, anti-inflammatory, and antithrombotic actions; delay development of plaques and increase their stability; and decrease wall stiffening. Omega-3 PUFA might affect BP, and studies conducted with ambulatory monitoring suggest that supplementation with these fatty acids decreases the average 24-h BP levels. This effect on BP is related to the pretreatment membrane content of omega-3 PUFA, and this might explain some inconsistencies among intervention trials. Meta-analyses indicate that omega-3 PUFA have a mild but significant BP lowering effect. While encouraging results were initially obtained with the use of omega-3 PUFA supplements in secondary prevention trials, meta-analyses have not confirmed the ability of these fatty acids to decrease the risk of coronary heart and cerebrovascular disease. CONCLUSIONS: Omega-3 PUFA are associated with significant improvement in vascular function and lowering of BP. However, the evidence currently supporting the role of these fatty acids in cardiovascular prevention is weak and needs further investigation.
Assuntos
Aterosclerose/prevenção & controle , Pressão Sanguínea/efeitos dos fármacos , Vasos Sanguíneos/efeitos dos fármacos , Ácidos Graxos Ômega-3/administração & dosagem , Hipertensão/prevenção & controle , Rigidez Vascular/efeitos dos fármacos , Aterosclerose/diagnóstico , Aterosclerose/etiologia , Aterosclerose/fisiopatologia , Vasos Sanguíneos/patologia , Vasos Sanguíneos/fisiopatologia , Medicina Baseada em Evidências , Humanos , Hipertensão/diagnóstico , Hipertensão/etiologia , Hipertensão/fisiopatologia , Placa Aterosclerótica , Fatores de Proteção , Fatores de Risco , Resultado do TratamentoRESUMO
Primary aldosteronism (PA) is detected with increasing frequency in hypertensive patients and is associated with excess cardiovascular, renal, and metabolic complications. For these reasons, appropriate choices for treatment of this endocrine condition are mandatory. Adrenalectomy is safely performed in PA patients when adrenal venous sampling (AVS) demonstrates lateralized aldosterone secretion. AVS, however, is a complex procedure and even among worldwide referral centers there are substantial discrepancies for interpretation of results. Also, in the majority of PA patients with lateralized aldosterone secretion, hypertension may persist after adrenalectomy requiring use of additional antihypertensive agents. Treatment with mineralocorticoid receptor antagonists (MRAs) is currently recommended for PA patients with bilateral adrenal disease, but these agents effectively decrease blood pressure also in patients with unilateral disease, although concern remains for possible sex-related side effects. Prospective studies indicate that MRAs have therapeutic values comparable to surgery in the long-term, inasmuch as they effectively correct metabolic abnormalities and subclinical organ damage and reduce the risk of cardiovascular events and renal disease progression. This article overviews the clinical outcomes obtained in patients with PA with use of MRAs.
Assuntos
Hiperaldosteronismo/tratamento farmacológico , Hiperaldosteronismo/cirurgia , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Aldosterona/metabolismo , Pressão Sanguínea , Humanos , Hiperaldosteronismo/fisiopatologia , Qualidade de Vida , Resultado do TratamentoRESUMO
Experimental and clinical evidence obtained in the last 2 decades clearly indicates that protracted exposure to inappropriately elevated aldosterone levels causes significant changes in left ventricular structure and function. Animal studies have demonstrated that aldosterone induces myocardial inflammatory changes and fibrosis in the presence of a high salt diet. Moreover, the effects of aldosterone on the heart have been investigated in different clinical conditions. These conditions include systolic and diastolic heart failure, essential hypertension, and primary aldosteronism that offers a unique clinical model to study the cardiac effects of excess aldosterone because these effects are isolated from those of the renin-angiotensin axis. A relatively clear picture is emerging from these studies with regard to aldosterone-related changes in left ventricular mass and geometry. Conversely, no direct effect of aldosterone on left ventricular diastolic function can be demonstrated and improvement of diastolic function obtained in some studies that have employed mineralocorticoid receptor blockers could result from left ventricular mass reduction. Animal experiments demonstrate that effects of aldosterone on the left ventricle require high salt intake to occur, but the evidence of this contribution of salt to aldosterone-induced cardiac changes in humans remains weaker and needs further research. The article reviews the results of clinical studies addressing the role of aldosterone in regulation of LV remodeling and diastolic function, and focuses on the possible relevance of salt intake.
Assuntos
Aldosterona/metabolismo , Ventrículos do Coração/fisiopatologia , Remodelação Ventricular , Hipertensão Essencial , Ventrículos do Coração/patologia , Humanos , Hiperaldosteronismo/fisiopatologia , Hipertensão/fisiopatologia , Função Ventricular EsquerdaRESUMO
BACKGROUND AND AIMS: Glycometabolic abnormalities are frequently found in hypertension and could affect the mechanical properties of carotid arteries. The aim of the study was to investigate the relationship of glucose tolerance, plasma insulin, and insulin sensitivity with carotid distensibility in middle-aged, non-diabetic hypertensive patients free of cardiac and vascular complications. METHOD AND RESULTS: In 93 patients with grade 1-2, uncomplicated, primary hypertension and 68 matched normotensive controls we measured plasma glucose and insulin at fast and after an oral glucose load (OGTT), calculated the HOMA-index as a marker of insulin sensitivity, and assessed distensibility of common carotid arteries by B-mode ultrasonography. Hypertensive patients were hyperinsulinemic and insulin-resistant as compared to normotensive controls. Hypertensive patients with impaired fasting glucose and/or impaired glucose tolerance had comparable distensibility of carotid arteries. Patients with decreased carotid distensibility were older and had higher body mass, fasting and post-OGTT plasma insulin, HOMA-index, and carotid IMT than the remaining patients, but no differences in glycated hemoglobin, and fasting or post-OGTT plasma glucose. Carotid coefficient of distensibility was inversely related and ß-stiffness directly related with fasting and post-OGTT plasma insulin, and HOMA-index. Multivariate logistic regression showed that age and post-OGTT plasma insulin levels predicted carotid artery stiffening independent of body mass index, sex, blood pressure, and plasma glucose levels. CONCLUSIONS: The study demonstrates that decreased insulin sensitivity and the related hyperinsulinemia but not hyperglycemia could contribute to carotid artery stiffening in middle-aged, non-diabetic hypertensive patients free of cardiovascular complications.
Assuntos
Artérias Carótidas/fisiopatologia , Hiperinsulinismo/fisiopatologia , Hipertensão/fisiopatologia , Resistência à Insulina/fisiologia , Rigidez Vascular , Adulto , Glicemia/análise , Índice de Massa Corporal , Artérias Carótidas/diagnóstico por imagem , Jejum , Feminino , Teste de Tolerância a Glucose , Humanos , Insulina/sangue , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , UltrassonografiaRESUMO
This multicenter, randomized, prospective, controlled trial (EVIDENCE study) aimed to determine short-term effects of early steroid withdrawal in renal transplant patients initially treated with everolimus, low-dose cyclosporine (CsA), and steroids. Patients were randomized to standard triple therapy with CsA, everolimus twice daily and steroids (group A), steroid-free immunosuppression (group B), or triple therapy once daily (group C). However, since patient enrollment was slower than expected, group C randomization was prematurely discontinued. The primary end point was treatment failure rate (composite end point of death, graft loss, biopsy-proven acute rejection, and loss to follow-up) between randomization and month 12. Patients evaluable for the primary end point included 139 randomized patients. According to intention-to-treat analysis, 2.8% of patients in group A and 14.7% in group B experienced treatment failure (95% upper confidence limit 19.7%). As this was higher than the predefined noninferiority limit of 10%, noninferiority could not be proved. No conclusive statements can be made on noninferiority of the steroid withdrawal regimen vs the standard regimen in these patients. Additional studies with longer follow-up are required to determine the efficacy of steroid-free immunosuppression in renal transplant recipients receiving everolimus.
Assuntos
Glucocorticoides/uso terapêutico , Metilprednisolona/uso terapêutico , Adulto , Ciclosporina/administração & dosagem , Ciclosporina/uso terapêutico , Quimioterapia Combinada , Everolimo , Feminino , Glucocorticoides/administração & dosagem , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/uso terapêutico , Análise de Intenção de Tratamento , Transplante de Rim/efeitos adversos , Masculino , Metilprednisolona/administração & dosagem , Pessoa de Meia-Idade , Estudos Prospectivos , Sirolimo/análogos & derivados , Falha de TratamentoRESUMO
A variety of abnormalities that occur in patients with primary aldosteronism indicate the capability of elevated aldosterone to induce cardiac damage over that induced by hypertension itself. This study investigates factors that can predict structural and functional changes of the heart after treatment of primary aldosteronism in a post-hoc analysis of 54 patients who were enrolled in a long-term follow-up study that was conducted after either adrenalectomy or treatment with spironolactone. Cardiac ultrasound assessment was performed before treatment and after with an average follow-up of 6.4 years. During follow-up, blood pressure decreased significantly and comparably in both treatment groups. In both treatment groups, left ventricular mass decreased significantly with a trend to improved diastolic filling profile and no changes in ventricular geometry. At univariate analysis, changes in left ventricular mass induced by treatment of primary aldosteronism were directly related with changes in systolic blood pressure and pretreatment plasma aldosterone levels measured both at baseline and after an intravenous saline load. This relationship was maintained when patients treated with adrenalectomy and spironolactone were analyzed separately. Multivariate regression analysis showed that changes in systolic blood pressure and pretreatment aldosterone levels were independent predictors of left ventricular mass changes after treatment. This study strongly supports a role of aldosterone in promoting left ventricular hypertrophy that is independent of the hypertension-related hemodynamic load and suggests a practical way to predict left ventricular mass changes following surgical and medical treatment of primary aldosteronism.
Assuntos
Hiperaldosteronismo/complicações , Hiperaldosteronismo/tratamento farmacológico , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/etiologia , Adrenalectomia , Adulto , Aldosterona/sangue , Pressão Sanguínea , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Hiperaldosteronismo/sangue , Hiperaldosteronismo/cirurgia , Hipertrofia Ventricular Esquerda/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Espironolactona/efeitos adversos , Espironolactona/uso terapêuticoRESUMO
Recent views suggest that long-term exposure to elevated aldosterone concentrations might result in cardiac, vascular, renal, and metabolic sequelae that occur independent of the blood pressure level. Indirect evidence of the untoward effects of aldosterone on the heart has been clearly established in clinical studies that have tested the effects of mineralocorticoid receptor antagonists in the treatment of systolic heart failure. As it has become clear in recent years, the interaction between aldosterone and the heart has to deal with additional actions of the hormone on specific cell types, cellular mechanisms, and molecules that are involved in regulation of tissue responses, leading to hypertrophy, remodeling, and fibrosis. The majority of these effects are mediated by activation of the mineralocorticoid receptors that are expressed in cardiomyocytes and cardiac fibroblasts, and mediate the genomic effects of the hormone. Evidence of interactions between aldosterone and the heart that occur independent of the renal effects of aldosterone, however, is not limited to the context of systolic heart failure and observations obtained in other disease states have led, together with findings of animal studies, to a better understanding of the potential benefits of aldosterone antagonists. In this narrative overview, we highlight the most recent findings that have been obtained in experimental animal models and in clinical conditions that include, in addition to systolic heart failure, primary aldosteronism, essential hypertension, diastolic heart failure, and arrhythmia.
Assuntos
Aldosterona/metabolismo , Cardiopatias/metabolismo , Hiperaldosteronismo/metabolismo , Animais , Coração/fisiopatologia , Cardiopatias/complicações , Cardiopatias/genética , Humanos , Hiperaldosteronismo/complicações , Hiperaldosteronismo/fisiopatologiaRESUMO
Este trabalho teve por objetivo avaliar o efeito de diferentes diâmetros de estacas na propagação de Lippia alba. Foram testadas estacas de 25 cm de comprimento, com diâmetros de 0,3-0,5 cm; 0,6-0,9 cm e 1-1,2 cm. Aos 30 e 60 dias após o plantio das estacas foram determinadas as características biométricas, como porcentagem de enraizamento, número de brotos, comprimento dos brotos, massas secas de brotos, estacas, raízes e total. Todos os diâmetros de estacas apresentaram altas taxas de enraizamento aos 30 dias, comprovando que a L. alba é uma espécie de fácil propagação por estaquia. A produção de mudas de L. alba deve ser realizada com estacas entre 1-1,2 cm de diâmetro, que foi superior aos outros diâmetros testados na maioria das características biométricas determinadas.
The aim of this work was to study the effect of different diameters of cuttings on the propagation and growth of Lippia alba. Cuttings of 25 cm length, with three different diameters: 0.3-0.5 cm, 0.6-0.9 cm and 1-1.2 cm, were tested. At 30 and 60 days after the planting of cuttings, the following biometric parameters were determined rooting percentage; number of buds, length of buds; dry matter of buds, cuttings and roots; and total dry matter. All diameters of cuttings presented high rates of rooting after 30 days, confirming that L. alba is an easy-to-root species. L. alba seedling production should use cuttings between 1-1.2 cm diameter, which was better than the others diameters considering most of the tested parameters.
Assuntos
Verbenaceae/crescimento & desenvolvimento , Agricultura/instrumentação , Agricultura/métodos , Plantas Medicinais/crescimento & desenvolvimento , Plantas/crescimento & desenvolvimentoRESUMO
Recent evidence indicates a greater frequency of primary aldosteronism (PA) among patients with hypertension than the previously accepted prevalence. PA was once considered a relatively benign form of hypertension associated with low incidence of organ complications. Recent views, however, suggest that long-term exposure to increased aldosterone levels might result in cardiovascular, renal, and metabolic sequelae that occur independently of the blood pressure level. Cross-sectional comparisons with patients with essential hypertension have demonstrated that patients with PA are at higher risk of cardiovascular events, have more frequent left ventricular hypertrophy and diastolic dysfunction, have greater urinary albumin losses as a marker of a hemodynamic intrarenal adaptation, and are insulin resistant. Some of these findings have been corroborated by the results of short-term, follow-up studies where it was shown that unilateral adrenalectomy or treatment with mineralocorticoid receptor (MR) antagonists are effective in correcting hypertension and hypokalemia. Normalization of blood pressure and correction of hypokalemia, however, are not the only goals in managing PA and effective prevention of organ complications is mandatory in these patients. The relative efficacy of adrenalectomy and MR antagonists, in the long-term, on the cardiovascular, renal, and metabolic outcomes still needs evaluation, being the aldosterone-induced tissue damage the main factor that could justify the cost of increasing efforts in screening of disease and differentiation of subtypes. In this narrative review, we summarize the results obtained with either surgical or medical treatment of PA and outline the findings of long-term, prospective studies on the effects of treatment on cardiovascular and renal outcomes and on insulin sensitivity.
Assuntos
Procedimentos Cirúrgicos Endócrinos/métodos , Hiperaldosteronismo/tratamento farmacológico , Hiperaldosteronismo/cirurgia , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Mineralocorticoides/antagonistas & inibidores , Glândulas Suprarrenais/cirurgia , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/terapia , Humanos , Hiperaldosteronismo/complicações , Nefropatias/complicações , Nefropatias/terapia , Doenças Metabólicas/complicações , Doenças Metabólicas/terapiaAssuntos
Canais de Cloreto/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Nefropatias/genética , Fenótipo , Regiões 5' não Traduzidas/genética , Adolescente , Adulto , Criança , Pré-Escolar , Doenças Genéticas Ligadas ao Cromossomo X/patologia , Humanos , Lactente , Nefropatias/patologia , Mutação/genética , Polimorfismo Conformacional de Fita Simples , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNARESUMO
PURPOSE: The purpose of this study was to assess the effectiveness of Cutting Balloon angioplasty in the treatment of stenoses in haemodialysis arteriovenous accesses. MATERIALS AND METHODS: Over the past 2 years, we have observed 80 patients with stenotic haemodialysis accesses; 24 of these (mean age 66.4 years, range 50-81) with 26 stenoses of 24 accesses (21 Cimino-Brescia fistulas and 3 dialysis loops) were selected for Cutting Balloon angioplasty. In 11 cases, the Cutting Balloon device was used after failure to dilate the access with a high-pressure balloon whereas in 15 cases (10 focal stenoses and 5 restenoses), it was used as a first choice. Two Cutting Balloon devices had a diameter of 8 mm, two of 7 mm, 11 of 6 mm, eight of 5 mm and one of 4 mm. The follow-up was performed by colour Doppler ultrasound (CDUS) and clinical assessment at 1, 3, 6, 12, 18 and 24 months. RESULTS: In all patients, postprocedure angiography demonstrated immediate technical success. No periprocedural complications occurred. Follow-up examinations (range 3-24 months, mean 18.2 months) demonstrated patency of the vascular access and its good functioning during dialysis in 23/24 cases (95%). Only in one case did we observe a haemodynamically significant restenosis, which was treated again with Cutting Balloon angioplasty. CONCLUSIONS: Cutting Balloon angioplasty is safe and effective in the treatment of haemodialysis access stenosis, especially in cases of severe stenosis, with low restenosis rate both in the short and medium term.
Assuntos
Angioplastia com Balão/instrumentação , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Oclusão de Enxerto Vascular/terapia , Diálise Renal , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Humanos , Pessoa de Meia-Idade , Radiografia Intervencionista , Estudos Retrospectivos , Stents , Resultado do Tratamento , Grau de Desobstrução VascularRESUMO
Renal stone formation is a common multifactorial disorder, of unknown etiology, with an established genetic contribution. Lifetime risk for nephrolithiasis is approximately 10% in Western populations, and uric acid stones account for 5%-10% of all stones, depending on climatic, dietary, and ethnic differences. We studied a small, isolated founder population in Sardinia, characterized by an increased prevalence of uric acid stones, and performed a genomewide search in a deep-rooted pedigree comprising many members who formed uric acid renal stones. The pedigree was created by tracing common ancestors of affected individuals through a genealogical database based on archival records kept by the parish church since 1640. This genealogical information was used as the basis for the study strategy, involving screening for alleles shared among affected individuals, originating from common ancestors, and utilization of large pedigrees to obtain greater power for linkage detection. We performed multistep linkage and allele-sharing analyses. In the initial stage, 382 markers were typed in 14 closely related affected subjects; interesting regions were subsequently investigated in the whole sample. We identified two chromosomal regions that may harbor loci with susceptibility genes for uric acid stones. The strongest evidence was observed on 10q21-q22, where a LOD score of 3.07 was obtained for D10S1652 under an affected-only dominant model, and a LOD score of 3.90 was obtained using a dominant pseudomarker assignment. The localization was supported also by multipoint allele-sharing statistics and by haplotype analysis of familial cases and of unrelated affected subjects collected from the isolate. In the second region on 20q13.1-13.3, multipoint nonparametric scores yielded suggestive evidence in a approximately 20-cM region, and further analysis is needed to confirm and fine-map this putative locus. Replication studies are required to investigate the involvement of these regions in the genetic contribution to uric acid stone formation.
Assuntos
Ligação Genética/genética , Predisposição Genética para Doença/genética , Cálculos Renais/genética , Ácido Úrico/metabolismo , Alelos , Antropometria , Mapeamento Cromossômico , Cromossomos Humanos Par 10/genética , Cromossomos Humanos Par 20/genética , Dieta , Comportamento Alimentar , Feminino , Efeito Fundador , Haplótipos/genética , Heterozigoto , Humanos , Concentração de Íons de Hidrogênio , Itália/epidemiologia , Cálculos Renais/epidemiologia , Cálculos Renais/metabolismo , Cálculos Renais/urina , Escore Lod , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Linhagem , Prevalência , Software , Ácido Úrico/urinaRESUMO
Despite revolutionary developments in minimally invasive methods for the removal of stones in the last 15 years, the medical prevention of urinary stones remains very rewarding, due to the continual increase in the prevalence of nephrolithiasis in western countries, the high recurrence rate of the disease, its complications, discomfort and the costs of lithotripsy. Medical prevention is highly effective (50-95% efficacy in different series) and cost-convenient; its basic elements are appropriate metabolic evaluation, adequate hydration, "common sense" diet, and, in selected cases, drugs of proven efficacy. Clinical-metabolic evaluation should aim at the recognition of specific types of nephrolithiasis, and sort out secondary and/or remediable cases, define urinary risk factors, assess patients' compliance and the side effects of any therapy during follow-up. Hydration has proved effective in clinical trials and population-based observational studies; "fluids" may consist of water (any kind), coffee (caffeinated or decaffeinated), tea, beer and wine; grapefruit juice appears to have an unexplained ill effect. Despite the lack of clinical demonstration that dietary manipulations reduce the recurrences of stones, biochemical and epidemiological data suggest that high sodium, animal protein and sucrose intake increase the risk. Undue reductions in Ca intake also appear to be detrimental both for stone recurrences and bone mineralisation: "adequate" Ca intake (800-1000 mg/day) should be encouraged, but only in food since supplemental Ca, as drugs, appears to increase the risk of stones. Effective drugs are available for cystine, uric acid, infected stones and several secondary causes of Ca nephrolithiasis; in "idiopathic" Ca nephrolithiasis, thiazides, allopurinol, K and K-Mg citrate and possibly neutral K phosphate have been shown to be effective, at least in specific metabolic contexts.
Assuntos
Cálculos Urinários/tratamento farmacológico , Cálculos Urinários/prevenção & controle , Bebidas , Ingestão de Líquidos , Humanos , Recidiva , Cálculos Urinários/etiologia , Cálculos Urinários/terapia , Urina/químicaAssuntos
Aldosterona/sangue , Taxa de Filtração Glomerular , Nefropatias/sangue , Magnésio/sangue , Simportadores , Adolescente , Adulto , Alcalose/sangue , Bicarbonatos/sangue , Proteínas de Transporte/genética , Criança , Eletrólitos/sangue , Humanos , Nefropatias/genética , Nefropatias/fisiopatologia , Mutação , Potássio/sangue , Receptores de Droga/genética , Renina/sangue , Simportadores de Cloreto de Sódio , Membro 3 da Família 12 de Carreador de Soluto , SíndromeRESUMO
Epithelia permit selective and regulated flux from apical to basolateral surfaces by transcellular passage through cells or paracellular flux between cells. Tight junctions constitute the barrier to paracellular conductance; however, little is known about the specific molecules that mediate paracellular permeabilities. Renal magnesium ion (Mg2+) resorption occurs predominantly through a paracellular conductance in the thick ascending limb of Henle (TAL). Here, positional cloning has identified a human gene, paracellin-1 (PCLN-1), mutations in which cause renal Mg2+ wasting. PCLN-1 is located in tight junctions of the TAL and is related to the claudin family of tight junction proteins. These findings provide insight into Mg2+ homeostasis, demonstrate the role of a tight junction protein in human disease, and identify an essential component of a selective paracellular conductance.
Assuntos
Nefropatias/genética , Alça do Néfron/metabolismo , Deficiência de Magnésio/genética , Magnésio/metabolismo , Proteínas de Membrana/fisiologia , Junções Íntimas/metabolismo , Sequência de Aminoácidos , Cálcio/urina , Cromossomos Humanos Par 3/genética , Claudinas , Clonagem Molecular , Feminino , Genes Recessivos , Homeostase , Humanos , Nefropatias/metabolismo , Túbulos Renais/química , Alça do Néfron/química , Magnésio/sangue , Deficiência de Magnésio/metabolismo , Masculino , Proteínas de Membrana/análise , Proteínas de Membrana/química , Proteínas de Membrana/genética , Dados de Sequência Molecular , Mutação , Linhagem , Mapeamento Físico do CromossomoRESUMO
Among the different forms of hereditary renal tubulopathies associated with hypokalemia, metabolic alkalosis and normotension, two main types of disorders have been identified: Gitelman disease, which appears to be a homogeneous post-Henle's loop disorder, and Bartter syndrome, a heterogeneous Henle loop disorder. A specific gene has been found responsible for Gitelman disease, encoding the thiazide-sensitive Na-Cl cotransporter (TSC) of the distal convoluted tubule. From a phenotypic point of view the characteristic findings of this disease are hypocalciuria, hypomagnesemia and tetanic crises appearing during childhood or later. Many subjects are asymptomatic. At least three different genes have been shown to be responsible for Bartter syndrome, characterized by mutations in the proteins encoding respectively the bumetanide-sensitive Na-K-2Cl cotransporter, the inwardly-rectifying renal potassium channel and a renal chloride channel, all protein transports located in the ascending limb of Henle's loop. Mutations in the first two transport proteins have been demonstrated in patients with the hypercalciuric forms of Bartter syndrome associated with nephrocalcinosis (respectively Bartter syndrome type I and II), who were often born after pregnancies complicated by polyhydramnios and premature delivery. Mutations in the gene encoding a renal chloride channel were recently recognized in patients with a Henle tubular defect not associated with nephrocalcinosis (Bartter syndrome type III). Most of the latter group of patients were normo-hypercalciuric and presented dehydration and life-threatening hypotension in the first year of life. However, these three genes do not explain all the patients with Bartter syndrome which unlike Gitelman disease, appears to be a very heterogeneous disorder. Clearance studies, especially if done during furosemide and/or hydrochlorothiazide administration, have been helpful in identifying the site of tubular involvement. Considering both phenotypic and genotypic data, we propose a clinical-pathophysiological and molecular approach to diagnose the different tubulopathies associated with hypokalemic metabolic alkalosis.