We have investigated the adrenal response, in eight healthy adult men, to low doses of ACTH(1–24) in order to define a dose which will elicit a response similar to that obtained with the short Synacthen test. The studies were performed at 14.00 h and blood samples were withdrawn at 5-min intervals after an i.v. bolus injection of ACTH(1–24). The sampling interval was crucial in determining the timing of the peak response. Using sampling times of 0, 10, 15, 20, 25 and 30 min ensured detection of 47 out of 48 peaks. A dose-dependent rise in plasma cortisol concentration was observed with bolus injections of ACTH(1–24) between 30 and 250 ng/1·73 m2 body surface area. Increasing the dose to 500 ng/1 ·73 m2 (500 times less than that used in the short Synacthen test) elicited an increment of plasma cortisol concentration of 200 nmol/l or greater in all subjects. Pretreatment with dexamethasone (1 mg) did not alter the timing of the peak cortisol concentration but blunted the increase (pretreatment: median, 159 nmol/l; range 83–239; on dexamethasone; median 62 nmol/l; range 21–207; P = 0·04). These data suggest that a dose of ACTH(1–24) of 500 ng/1·73 m2 satisfies the criteria of the short Synacthen test and may provide a useful method of investigating adrenal function. Journal of Endocrinology (1991) 130, 475–479
Primary ciliary dyskinesia (PCD) has been considered a relatively mild disease, especially compared to cystic fibrosis (CF), but studies on lung function in PCD patients have been few and small.This study compared lung function from spirometry of PCD patients to normal reference values and to published data from CF patients. We calculated z-scores and % predicted values for forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) using the Global Lung Function Initiative 2012 values for 991 patients from the international PCD Cohort. We then assessed associations with age, sex, country, diagnostic certainty, organ laterality, body mass index and age at diagnosis in linear regression models. Lung function in PCD patients was reduced compared to reference values in both sexes and all age groups. Children aged 6–9 years had the smallest impairment (FEV1z-score −0.84 (−1.03 to −0.65), FVC z-score −0.31 (−0.51 to −0.11)). Compared to CF patients, FEV1was similarly reduced in children (age 6–9 years PCD 91% (88–93%); CF 90% (88–91%)), but less impaired in young adults (age 18–21 years PCD 79% (76–82%); CF 66% (65–68%)). The results suggest that PCD affects lung function from early in life, which emphasises the importance of early standardised care for all patients.
Objectives To identify and summarise volatile organic compound (VOC) exposure profiles of healthcare occupations. Methods Personal (n=143) and mobile area (n=207) evacuated canisters were collected and analysed by a gas chromatograph/mass spectrometer to assess exposures to 14 VOCs among 14 healthcare occupations in five hospitals. Participants were volunteers identified by their supervisors. Summary statistics were calculated by occupation. Principal component analysis (PCA) was used to reduce the 14 analyte inputs to five orthogonal factors and identify occupations that were associated with these factors. Linear regressions were used to assess the association between personal and mobile area samples. Results Exposure profiles differed among occupations; ethanol had the highest geometric mean (GM) among nursing assistants (∼4900 and ∼1900 µg/m3, personal and area), and 2-propanol had the highest GM among medical equipment preparers (∼4600 and ∼2000 µg/m3, personal and area). The highest total personal VOC exposures were among nursing assistants (∼9200 µg/m3), licensed practical nurses (∼8700 µg/m3) and medical equipment preparers (∼7900 µg/m3). The influence of the PCA factors developed from personal exposure estimates varied by occupation, which enabled a comparative assessment of occupations. For example, factor 1, indicative of solvent use, was positively correlated with clinical laboratory and floor stripping/waxing occupations and tasks. Overall, a significant correlation was observed (r=0.88) between matched personal and mobile area samples, but varied considerably by analyte (r=0.23–0.64). Conclusions Healthcare workers are exposed to a variety of chemicals that vary with the activities and products used during activities. These VOC profiles are useful for estimating exposures for occupational hazard ranking for industrial hygienists as well as epidemiological studies.
We compared the reproducibility and repeatability of the acute adrenal response to low doses (90 and 500 ng/1·73 m2) of Synacthen (ACTH(1–24)) with that of the standard dose (250 μg/1·73 m2). We also examined the effect of basal cortisol levels on peak values achieved after stimulation with a low dose. ACTH(1–24) was given to six male volunteers: 90 ng/1·73 m2 twice at 90-min intervals on day 1, and 90 and 500 ng/1·73 m2 once on day 2 and 250 μg/1·73 m2 once on day 3. The rise in serum cortisol concentration with repeated low doses of ACTH was not attenuated (161 ± 49 (s.d.) nmol/l on initial vs 150 ± 41 nmol/l on repeat stimulation; P = 0·5) and this was reproducible (161 ± 49 nmol/l on day 1 vs 148 ± 15 nmol/l on day 2; P = 0·6). A dose of 500 ng ACTH(1–24)/1·73 m2 produced a maximal adrenal response in that the rise in serum cortisol concentration at 20 min was identical with that produced at the same time by the standard dose of 250 μg/1·73 m2. There was a strong positive correlation between the basal cortisol level and peak cortisol concentration after low-dose ACTH stimulation (r = 0·93, P < 0·001) but not between the basal cortisol level and the incremental rise (r= −0·1, P = 0·69). These results suggest that the cortisol response to low-dose ACTH stimulation is reproducible and not attenuated by repeat stimulation at 90-min intervals. The incremental rise in serum cortisol concentration after ACTH stimulation appears constant in these situations and is not influenced by the basal cortisol level. When there is concern that the standard dose may be excessive and mask subtle but important changes in adrenal function, the low dose (500 ng) of ACTH should be used. Journal of Endocrinology (1993) 136, 167–172
Pulmonary exacerbations are a cause of significant morbidity in patients with primary ciliary dyskinesia (PCD) and are frequently used as an outcome measure in clinical research into chronic lung diseases. So far, there has been no consensus on the definition of pulmonary exacerbations in PCD.30 multidisciplinary experts and patients developed a consensus definition for children and adults with PCD. Following a systematic review, the panel used a modified Delphi process with a combination of face-to-face meetings and e-surveys to develop a definition that can be used in research settings for children and adults with PCD.A pulmonary exacerbation was defined by the presence of three or more of the following seven items: 1) increased cough, 2) change in sputum volume and/or colour, 3) increased shortness of breath perceived by the patient or parent, 4) decision to start or change antibiotic treatment because of perceived pulmonary symptoms, 5) malaise, tiredness, fatigue or lethargy, 6) new or increased haemoptysis, and 7) temperature >38°C.The consensus panel proposed that the definition should be used for future clinical trials. The definition should be validated and the usability assessed during these studies.
22 July 2005 in Ultrasound in Obstetrics & Gynecology