PubMed HealthSearch

Biomedical subjects

J Hruby

Publications and source records attributed to J Hruby.

4 recordsLinked to original sources

Different regulation of adrenocorticotropin and cortisol secretion in young, mentally healthy elderly and patients with senile dementia of Alzheimer's type.

Previous studies suggest that an alteration of the neuroendocrine system may particularly occur in senile dementia of Alzheimer's type (SDAT). In the present study the reactivity of the hypophyseal-adrenocortical axis (HPA) in the elderly was assessed by hormonal stimulation of the hypophysis. Twelve young men (aged 21-24 yr), 15 mentally healthy elderly (aged 65-90 yr), and 12 patients with SDAT (aged 60-84 yr) received an iv bolus injection containing 50 micrograms CRH and 0.5 IU lysine vasopressin after a baseline period of 2 h. ACTH, cortisol, and dehydroepiandrosterone secretion was monitored over a period of 2 h before and after the injection. The baseline ACTH concentrations were increased in both groups of elderly, the baseline cortisol levels were not different in either group. The peak ACTH and cortisol levels were significantly elevated in the mentally healthy elderly, whereas senile demented patients showed a rise comparable with that in the young subjects. Moreover, in the demented patients the post-stimulus decline in plasma ACTH levels seemed to be delayed. Dehydroepiandrosterone was significantly lowered in subjects of all ages. Our results demonstrate an enhanced reactivity of the HPA in mentally healthy elderly. This is possibly due to a diminished sensitivity of the feedback regulation to glucocorticoids. However, SDAT patients had, compared to healthy elderly subjects, an attenuated response to CRH/lysine vasopressin and a prolonged ACTH secretion, indicating alterations of the HPA in this disease.

Adrenocorticotropic Hormone

[An adapter for the intratracheal administration of a bronchodilator in intubated patients].

To relieve intraoperative bronchospasm, bronchodilators are often given via endotracheal tube. Most anesthetic adapters for dose-metered inhalers deliver the agent into the anesthesia circuit outside the tube. An unpredictable loss of drug due to sedimentation on the inner wall of the tube results. A simple and cost-effective device for delivering the agent near the tip of the tube is presented.

Anesthesiology

Variability of routine pulmonary function tests.

Pulmonary function tests sometimes indicate a progressive deterioration and at other times a 'stepwise' worsening which may be followed by improvement. Interpretation depends on the extent of random or diurnal variations in function. Routing pulmonary function tests (VC, FEV1, FRC, and airway resistance (Raw)) were repeatedly measured in normal subjects, patients with stable irreversible airways obstruction, and patients with stable restrictive disease. In all groups there was a significant (P less than 0.001) diurnal variation in Raw, with high values in the morning, low values at noon, and rising values in the evening. The midday Raw values were about 80% of the highest daily values. The considerable random and diurnal variability seen in all tests is reflected in the range of high and low values (% of mean individual response) in individuals. The largest variation in an individual between measurements taken at two different times was 81% in Raw (range: 40% above to 41% below the mean). There was less variation in FEV1 (29%), FRC (62%), and VC (30%). Thus the finding of a stepwise change in function could reflect its natrual variability. When repeated studies are done to assess progress or the effects of therapy on disease, there are many factors, including the time of day at which the tests are performed, which should be standardized as far as possible.

Air Pollution