CFTR modulation with elexacaftor-tezacaftor-ivacaftor in people with cystic fibrosis assessed by the β-adrenergic sweat rate assay

Essential fatty acid supplementation with oral safflower oil (1 gm/kg/day) to 11 cystic fibrosis patients (aged 6 months to 14 years) for one year produced no significant change in sweat chloride concentration (mEq/liter) or sweat rate (gm/min/m2). Addition of vitamin E (10 mg/kg/day) to the safflower oil had no effect on sweat chloride concentration or rate compared to placebo. No clinical improvement could be detected compared to a control group. These results do not support previous reports of the effects of fatty acid supplementation on sweat electrolyte concentrations in cystic fibrosis.

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Laboratory performance of sweat conductivity for the screening of cystic fibrosis

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2017-0530 ◽

2018 ◽

Vol 56 (4) ◽

pp. 554-559 ◽

Cited By ~ 2

Author(s):

Ronda F. Greaves ◽

Lisa Jolly ◽

John Massie ◽

Sue Scott ◽

Veronica C. Wiley ◽

...

Keyword(s):

Cystic Fibrosis ◽

Quality Assurance ◽

Royal College ◽

English Language ◽

Sweat Rate ◽

Proper Action ◽

Laboratory Performance ◽

Reporting Practices ◽

Sweat Chloride ◽

Sweat Testing

Abstract Background: There are several complementary English-language guidelines for the performance of the sweat chloride test. These guidelines also incorporate information for the collection of conductivity samples. However, recommendations for the measurement and reporting of sweat conductivity are less clear than for sweat chloride. The aim of the study was to develop an understanding of the testing and reporting practices of sweat conductivity in Australasian laboratories. Methods: A survey specifically directed at conductivity testing was sent to the 12 laboratories registered with the Royal College of Pathologists of Australasia Quality Assurance Programs. Results: Nine (75%) laboratories participated in the survey, seven of whom used Wescor Macroduct® for collecting sweat and the Wescor SWEAT·CHEK™ for conductivity testing, and the remaining two used the Wescor Nanoduct®. There was considerable variation in frequency and staffing for this test. Likewise, criteria about which patients it was inappropriate to test, definitions of adequate collection sweat rate, cutoffs and actions recommended on the basis of the result showed variations between laboratories. Conclusions: Variations in sweat conductivity testing and reporting reflect many of the same issues that were revealed in sweat chloride test audits and have the potential to lead to uncertainty about the result and the proper action in response to the result. We recommend that sweat testing guidelines should include clearer statements about the use of sweat conductivity.

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Image-based β-adrenergic sweat rate assay captures minimal cystic fibrosis transmembrane conductance regulator function

Pediatric Research ◽

10.1038/s41390-019-0503-8 ◽

2019 ◽

Vol 87 (1) ◽

pp. 137-145 ◽

Cited By ~ 1

Author(s):

Danieli Barino Salinas ◽

Yu-Hao Peng ◽

Brian Horwich ◽

Choo Phei Wee ◽

Eric Frisbee ◽

...

Keyword(s):

Cystic Fibrosis ◽

Sweat Rate ◽

Transmembrane Conductance Regulator ◽

Transmembrane Conductance ◽

Cystic Fibrosis Transmembrane

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Basal Serum Cortisol and Testosterone/Cortisol Ratio Are Related to Rate of Na+ Lost During Exercise in Elite Soccer Players

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2019-0129 ◽

2019 ◽

Vol 29 (6) ◽

pp. 658-663 ◽

Cited By ~ 2

Author(s):

Mauricio Castro-Sepulveda ◽

Jorge Cancino ◽

Rodrigo Fernández-Verdejo ◽

Cristian Pérez-Luco ◽

Sebastian Jannas-Vela ◽

...

Keyword(s):

Cystic Fibrosis ◽

Sweat Rate ◽

Training Session ◽

Soccer Players ◽

Transmembrane Conductance Regulator ◽

Serum Concentrations ◽

Transmembrane Conductance ◽

Basal Serum ◽

Cystic Fibrosis Transmembrane ◽

Cortisol Ratio

During exercise, the human body maintains optimal body temperature through thermoregulatory sweating, which implies the loss of water, sodium (Na+), and other electrolytes. Sweat rate and sweat Na+ concentration show high interindividual variability, even in individuals exercising under similar conditions. Testosterone and cortisol may regulate sweat Na+ loss by modifying the expression/activity of the cystic fibrosis transmembrane conductance regulator. This has not been tested. As a first approximation, the authors aimed to determine whether basal serum concentrations of testosterone or cortisol, or the testosterone/cortisol ratio relate to sweat Na+ loss during exercise. A total of 22 male elite soccer players participated in the study. Testosterone and cortisol were measured in blood samples before exercise (basal). Sweat samples were collected during a training session, and sweat Na+ concentration was determined. The basal serum concentrations of testosterone and cortisol and their ratio were (mean [SD]) 13.6 (3.3) pg/ml, 228.9 (41.4) ng/ml, and 0.06 (0.02), respectively. During exercise, the rate of Na+ loss was related to cortisol (r = .43; p < .05) and to the testosterone/cortisol ratio (r = −.46; p < .01), independently of the sweating rate. The results suggest that cortisol and the testosterone/cortisol ratio may influence Na+ loss during exercise. It is unknown whether this regulation depends on the cystic fibrosis transmembrane conductance regulator.

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A simplified cyclic adenosine monophosphate–mediated sweat rate test for quantitative measure of cystic fibrosis transmembrane regulator (CFTR) function

The Journal of Pediatrics ◽

10.1067/mpd.2000.109198 ◽

2000 ◽

Vol 137 (6) ◽

pp. 849-855 ◽

Cited By ~ 6

Author(s):

Amy Callen ◽

Marie Diener-West ◽

Pamela L. Zeitlin ◽

Ronald C. Rubenstein

Keyword(s):

Cystic Fibrosis ◽

Sweat Rate ◽

Quantitative Measure ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Cystic Fibrosis Transmembrane Regulator ◽

Rate Test ◽

Cystic Fibrosis Transmembrane

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Pregnancy in cystic fibrosis of the pancreas

JAMA ◽

10.1001/jama.195.12.993 ◽

1966 ◽

Vol 195 (12) ◽

pp. 993-1000 ◽

Cited By ~ 9

Author(s):

R. J. Grand

Keyword(s):

Cystic Fibrosis

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Freeze-Fracture Examination of Tight Junctions of Human Eccrine Sweat Glands

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600002786 ◽

1980 ◽

Vol 38 ◽

pp. 634-635

Author(s):

J. V. Briggman ◽

J. Bigelow ◽

H. Bank ◽

S. S. Spicer

Keyword(s):

Cystic Fibrosis ◽

Freeze Fracture ◽

Sweat Glands ◽

Hypertonic Solution ◽

Dark Cells ◽

Clear Cells ◽

Junctional Complexes ◽

Secretory Coil ◽

Eccrine Sweat Glands ◽

Eccrine Sweat

The prevalence of strands shown by freeze-fracture in the zonula occludens of junctional complexes is thought to correspond closely with the transepi-thelial electrical resistance and with the tightness of the junction and its obstruction to paracellular flow.1 The complexity of the network of junc¬tional complex strands does not appear invariably related to the degree of tightness of the junction, however, as rabbit ileal junctions have a complex network of strands and are permeable to lanthanum. In human eccrine sweat glands the extent of paracellular relative to transcellular flow remains unknown, both for secretion of the isotonic precursor fluid by the coil and for resorption of a hypertonic solution by the duct. The studies reported here undertook, therefore, to determine with the freeze-fracture technique the complexity of the network of ridges in the junctional complexes between cells in the secretory coil and the sweat ducts. Glands from a patient with cystic fibrosis were also examined because an alteration in junctional strands could underlie the decreased Na+ resorption by sweat ducts in this disease. Freeze-fracture replicas were prepared by standard procedures on isolated coil and duct segments of human sweat glands. Junctional complexes between clear cells, between dark cells and between clear and dark cells on the main lumen, and between clear cells on intercellular canaliculi of the coil con¬tained abundant anastomosing closely spaced strands averaging 6.4 + 0.7 (mean + SE) and 9.0 +0.5 (Fig. 1) per complex, respectively. Thus, the junctions in the intercellular canaliculi of the coil appeared comparable in complexity to those of tight epithlia. Occasional junctions exhibited, in addition, 2 to 5 widely spaced anastomosing strands in a very close network basal to the compact network. The fewer junctional complexes observed thus far between the superficial duct cells consisted on the average of 6 strands arranged in a close network and 1 to 4 underlying strands that lay widely separated from one another (Fig. 2). The duct epitelium would, thus, be judged slightly more "leaky" than the coil. Infrequent junctional complexes observed to date in the secretory coil segment of a cystic fibrosis specimen disclosed rela¬tively few closely crowded strands.

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