Two brothers are described with chronic suppurative pulmonary disease. One has classical cystic fibrosis with complete pancreatic involvement and abnormal sweat test. The other had incomplete pancreatic disease with repeatedly normal sweat tests. The implications of a negative sweat test in patients with cystic fibrosis are discussed.

Patients with hypoxic chronic obstructive pulmonary disease (COPD) have evidence of a subclinical parasympathetic autonomic neuropathy, with apparent preservation of sympathetic function. However, these cardiovascular-respiratory tests might have been biased by concomitant chest disease, the acetylcholine sweat-spot test avoids this bias. This sweat-spot test assesses sympathetic nerve function...

Although sweat conductivity values are well matched with chloride concentrations for cystic fibrosis (CF) diagnosis, sweat conductivity is not accepted as a definitive diagnostic tool but only a screening method. The aim of this study was to compare the sweat chloride measurements and sweat conductivity values of our patients, and to determine cut-off values of conductivity for making or exclud...

The sweat test, even if carried out by an experienced technician, sometimes lacks reproducibility owing presumably to physiological variations (patient's diet, temperature, and other factors at present unrecognized). Some patients are particularly prone to exhibit this variability and in them a single sweat test is almost valueless. The aldosterone status is believed to be responsible for a rec...

A new sweat test (CF Indicator; Medtronic, Inc.) for cystic fibrosis (CF) features a compact, portable configuration of electrodes that dispense pilocarpine for iontophoresis. A disposable chloride sensor patch absorbs a specified volume of sweat, in which the chloride concentration is immediately determined as less than 40, 40-60, or greater than 60 mmol/L. We assessed the performance of the s...

β-adrenergically stimulated sweat secretion depends on the function of the cystic fibrosis transmembrane conductance regulator (CFTR) and discriminates between cystic fibrosis (CF) patients and healthy controls. Therefore, we sought to determine the feasibility, safety, and efficacy of assaying β-adrenergic sweating in children identified by CF newborn screening to help determine prognoses for ...

Abnormal ductal NaCl absorption has been known as the only defect in cystic fibrosis (CF) sweat glands. We have fortuitously found that the secretory portion of CF sweat glands is also abnormal in that it failed to show a sweating response to beta adrenergic stimulation (isoproterenol, [ISO]) both in vivo and in vitro. For the in vitro sweat test, eccrine sweat glands were isolated from skin bi...