Friday, 05 January 2018 14:06

In a patient with Bartter's syndrome (increased plasma renin, juxtaglomerular-cell hyperplasia, hyperaldosteronism and hypokalemia, but no hypertension), aldosterone excretion and secretion were increased only moderately despite marked elevation of plasma renin, presumably because of suppression of aldosterone production by hypokalemia. When the serum potassium was raised by administration of potassium chloride and spironolactone, while normal sodium balance was maintained, aldosterone excretion rose markedly. Infusion of albumin decreased plasma renin and aldosterone secretion, and restored normal sensitivity to the pressor effect of exogenous angiotensin. Suppression of aldosterone production to normal limits by administration of albumin, amino-glutethimide or dexamethasone failed to correct the hypokalemia, indicating that some factor other than hyperaldosteronism may contribute to urinary potassium wastage in this syndrome. This study and others raise the possibility that in some patients with Bartter's syndrome the primary defect is impairment of proximal sodium reabsorption.

Friday, 20 March 2015 05:25

MOST parents dream of a 5-week-old baby who sleeps through the night, but Aga Warnell knew something was wrong. Her baby, Nina, just wasn't hungry in the way her other daughters had been.

Within weeks, Nina became very ill, says her father, Graeme. She was admitted to hospital with a rotavirus infection. Then she picked up pneumonia.

It turned out Nina had a condition called severe combined immunodeficiency (SCID). She had been born without an immune system due to a genetic defect. It is also known as "bubble boy" disease, since people affected have to live in a sterile environment. "The doctors said 'you need to prepare yourself for the fact that Nina probably isn't going to survive'," says Graeme.

 

Sunday, 11 January 2015 20:13

Gene therapy emerged 15 yr ago with great expectations for a marriage between the remarkable advances in molecular biology of the previous decade and clinical medicine. It was originally an innovative treatment for incurable diseases, so-called genetic disorders, in which the disease was caused by mutation, truncation, or complete loss of a single gene. In 1990, the first successful gene therapy was performed on two girls with adenosine deaminase (ADA) deficiency, which causes severe immunodeficiency (1). The number of peripheral lymphocytes increased by repeated injection of lymphocytes carrying the exogenous ADA gene, and the girls’ health stabilized to the point that they were able to attend school. Soon after, however, the investigators realized that the success of the gene therapy for ADA deficiency is a rare exception because most of the monogenic disorders cannot be treated simply by unlimited overexpression of the deficient gene. In addition, some of the monogenic diseases cannot be treated with available vectors because the genes are much larger than the size of the gene cassette of the vectors.

Monday, 29 December 2014 00:21