Andrés Valdivieso

Minoxidil in Breast Milk

Excerpt To the editor: Minoxidil is a potent vasodilator used in the treatment of severe hypertension (1). No pregnancies have been reported in patients receiving the drug. We report the case of a ...

Expression of gremlin, a bone morphogenetic protein antagonist,is associated with vascular calcification in uraemia

BACKGROUND Vascular calcification has been widely recognized as a significant contributor to cardiovascular risk in patients with chronic kidney disease. Recent evidence suggests that BMP-7 decreases the vascular calcification observed in uraemic rats, while BMP-2 could also be participating in this process. Gremlin, a bone morphogenetic protein antagonist, has been detected in rat aortic vascular smooth muscle cells (VSMCs), and since the role of the VSMCs into vascular calcification in uraemia is considered critical in this process, we hypothesized that gremlin could be participating in its pathogenesis. With this aim, we studied its expression in aorta from uraemic rats with calcitriol-induced vascular calcification and in 16-vessel biopsies of uraemic patients undergoing kidney transplantation. METHODS Gremlin was detected by in situ hybridization (ISH) and immunohistochemistry (IMH). BMP-7, BMP-2 and BMP-2 receptor (BMPR2) were detected by IMH. Vascular calcification was assessed by the von Kossa staining method. Sham-operated and 5/6 nephrectomized rats (NFX) (1.2%P) were treated with vehicle or calcitriol (80 ng/kg, intraperitoneally every other day). Rats were killed after 4 weeks of treatment, and abdominal aorta was dissected for assessment of gremlin expression and vascular calcification. Epigastric arteries were obtained from dialysis patients during kidney transplantation procedure. Arteries from kidney donors were also studied. RESULTS NFX rats developed a mild vascular calcification, whereas NFX-calcitriol rats developed a severe vascular and tissue calcification. A marked overexpression of gremlin was observed in the vascular media of aorta from NFX-calcitriol rats as compared with NFX and sham-calcitriol groups (4.8 +/- 1.3 versus 0.59 +/- 0.17 versus 0.19 +/- 0.07 percentage/mm(2), P < 0.01), and correlated with the BMP-2 and BMPR2 expression. Sham rats showed minimal or null gremlin expression. BMP-7 was not found in sham or calcified arteries. In human studies, we observed strong expression of gremlin mRNA and protein in the media layer of vessels from uraemic patients as compared with those from normal humans (staining score 3.72 +/- 0.95 versus 0.91 +/- 0.08 percentage/mm(2), P < 0.05). CONCLUSION We observed a marked gremlin overexpression in the media layer of vessels in uraemic rats and patients in association with vascular calcification and BMP-2 expression. We postulate that gremlin may play a role in the vascular calcification process in uraemia, and its interaction with BMP-7 or BMP-2 remains to be elucidated.

Hipokalemia, hipovolemia y repercusión electrocardiográfica secundarias a ingesta prolongada de furosemida: Caso clínico

<3.5 mEq/l) is a potentially seriousadverse effect of diuretic ingestion. We report a 27 year-old woman admitted with muscleweakness, a serum potassium of 2.0 mEq/1, metabolic alkalosis and EKG abnormalitiessimulating cardiac ischemia, that reverted with potassium chloride administration. Sheadmitted high dose furosemide self-medication for edema. Glomerular filtration rate, tubularsodium reabsortion, potassium secretion, the renin-aldosterone system, total body waterdistribution and capillary permeability, were studied sequentially until 90 days after heradmission. There was hyperactivity of the renin-aldosterone axis, reduction in extracellularand intracellular volumes, normal capillary permeability and high sodium tubularreabsorption, probably explained by a “rebound” salt retention associated with her decreasedextracellular volume (Rev Med Chile 2007; 135: 1456-62).(

Recomendaciones del Comité de Ética de la Sociedad Chilena de Nefrología para el manejo de los problemas ético-clínicos de pacientes adultos con enfermedad renal crónica terminal

There are different approaches to treat patients with End Stage Renal Disease (ESRD): hemodialysis, peritoneal dialysis, renal transplantation and conservative medical management. The choice of the best therapy for each patient, needs both clinical and ethical skills. The Ethics Committee of the Chilean Society of Nephrology has elaborated recommendations to help health workers to deal with the ethical and clinical problems related to patients suffering ESRD. Its goal is to guide, at a national level, the effective use of minimal standards in the treatment and care of patients with ESRD, including appropriate care and information for patients, therapy selection, management of difficult cases and potential conflicts.

Conflictos de intereses en nefrología

Since doctors disposed of effective tools to serve their patients, they had to worry about the proper management of available resources and how to deal with the relationship with the industry that provides such resources. In this relationship, health professionals may be involved in conflicts of interest that they need to acknowledge and learn how to handle. This article discusses the conflicts of interest in nephrology. Its objectives are to identify those areas where such conflicts could occur; to help to solve them, always considering the best interest of patients; and to help health workers to keep in mind that they have to preserve their autonomy and professional integrity. Conflicts of interest of professionals in the renal area and related scientific societies, with the industry producing equipment, supplies and drugs are reviewed. Dichotomy, payment for referral, self-referral of patients and incentives for cost control are analyzed. Finally, recommendations to help preserve a good practice in nephrology are made

Problemas ético-clínicos en hemodiálisis crónica: percepción de médicos y enfermeras

Background: Clinical teams working at chronic hemodialysis centers (CHC) frequently have to face ethical problems, but there is no systematic approach to deal with it. Aim: To study the ethical problems perceived by health professionals at CHC. Material and methods: Eighty randomly selected physicians and 139 nurses from 23 CHC, answered a structured questionnaire, devised by the research team. Results: Twenty-six percent of respondents had postgraduate studies in clinical ethics. The ethical problems mentioned by respondents were therapeutic disproportion in 66.7%, lack of communication between patients, their families and the clinical team in 25.9%, personal conflicts of interests related with hemodialysis prescription in 14.6% and conflicts of interests of other members of the clinical team in 30.6%. The percentage of respondents that experienced not starting or discontinuing hemodialysis treatment due to decision of patients’ relatives was 86.8%. Only 45.2% of health professionals had the opportunity to take part in decision-making meetings. Eighty seven percent of respondents supported the use of advanced directives in the event of a cardio respiratory arrest during treatment. Conclusions: To improve the approach to ethical problems in CHC, it is necessary to improve training in clinical ethics, promote an effective dialogue between the patients, their families and health professionals, and follow their advance directives in case of cardiac arrest during treatment.