Biomedical subjects

E Fliers

Publications and source records attributed to E Fliers.

57 records · Page 4Linked to original sources

PubMedDate not supplied

Activation of vasopressinergic and oxytocinergic neurons during aging in the Wistar rat.

The activity of the hypothalamo-neurohypophyseal system (HNS) was determined in male Wistar rats from 3 to 32 months of age. Plasma levels of vasopressin (AVP) and oxytocin (OXT) were measured by means of a radioimmunoassay. In addition, the distribution of the Golgi apparatus marker enzyme thiamine-pyrophosphatase (TPP-ase) was measured as a parameter for neurosecretory activity in the hypothalamic supraoptic and paraventricular nuclei (SON and PVN). Plasma levels of radioimmunoassayable AVP were increased in the 32-month-old animals. Plasma levels of radioimmunoassayable OXT in 32-month-old animals did not differ from the levels found in the youngest group, but were higher than in 11-month-old animals. Neurosecretory activity in the SON was similar in 3- and 32-month-old animals, whereas in the PVN neurosecretory activity was increased in the 32-month-old animals. Urine excretion decreased between 6 and 11 months of age and remained on the same level until 32 months of age. In other words, instead of a loss of HNS function as has been suggested in the literature, an increased neurosecretory activity was observed in aged rats.

Aging↗

PubMedDate not supplied

The supraoptic and paraventricular nuclei of the human hypothalamus in relation to sex, age and Alzheimer's disease.

Volume and total cell number were determined in the supraoptic (SON) and paraventricular (PVN) nuclei of 14 male and 16 female subjects ranging in age from 10 to 93 years. In addition, 4 male and 6 female subjects suffering from Alzheimer's disease (AD) and ranging in age from 46 to 97 years were studied. Subjects were divided into two age groups, viz., "young" for subjects up to 60 years, and "old" for subjects older than 60. No sex differences in volume and in total cell number were observed in the SON and PVN in either age group. In addition, no significant correlation was found between total cell number in the SON and PVN and brain weight. No significant differences in volume and total cell number were found in either the SON or PVN between young and old control subjects or between AD cases and controls, indicating that these nuclei are spared from degenerative changes in senescence and AD. Determination of neuron numbers in the SON supported this view. In contrast, volume and total cell counts in the suprachiasmatic decreased in senescence and were dramatically reduced in AD. The present results indicate the occurrence of differential patterns of cell loss within the human hypothalamus with aging and in AD, which are proposed to be related to functional differences between the hypothalamic nuclei.

Adolescent↗

PubMedDate not supplied

Establishment of reference values for endocrine tests--part V: acromegaly.

BACKGROUND: Plasma insulin-like growth factor 1 (IGF-1) and the response of growth hormone (GH) to oral glucose are frequently used in the evaluation of patients suspected of acromegaly. Because of the implementation of new assay methodology for GH and IGF-1, we have established the reference values for these tests, as well as for urinary GH excretion. METHODS: From the general population, 50 subjects were recruited, equally distributed according to sex and age between 20 and 70 years. Two consecutive 24-hour urine samples were collected to determine urinary GH. Plasma IGF-1 was measured as well as the GH response during an oral glucose tolerance test (OGTT) with 100 g glucose. Basal plasma IGF-1 was also measured in 250 subjects recruited likewise from the general population who had participated in previous studies on reference values. RESULTS: The following reference ranges were established: urinary GH < 5-46 microU/24 h; nadir GH after OGTT < or =1.5 mU/l for males and < or =2.0 mU/l for females. IGF-1 was divided into age groups: 20-30 years 8-61 nmol/l; 31-40 years 8-41 nmol/; 41-50 years 7-36 nmol/l; 51-60 years 5-37 nmol/l; and 61-70 years 7-27 nmol/l. CONCLUSION: We have established reference values with state-of-the-art assay methodology for the diagnostic tests frequently used in the evaluation of patients suspected of acromegaly.

Acromegaly↗