Biomedical subjects

A M Huisman

Publications and source records attributed to A M Huisman.

21 records · Page 2Linked to original sources

PubMed1981

Quantitative differences in collateralization of the descending spinal pathways from red nucleus and other brain stem cell groups in rat as demonstrated with the multiple fluorescent retrograde tracer technique.

In 8 rats 'True Blue' was injected into dorsal half of C5-C8 spinal grey, 5 days later 'Nuclear Yellow' was injected in midthoracic, upper lumbar, lumbosacral and sacral cord respectively. The animals were sacrificed about 43 hours after NY injections. The distribution of retrogradely labeled neurons was studied in Red Nucleus, in Ventrolateral Pontine Tegmentum and in Nucleus Raphe Magnus, all of which project to spinal dorsal grey. In Red Nucleus large populations of single TB-labeled neurons and single NY-labeled ones occurred in the dorsomedial and ventrolateral part, respectively. In addition, about 8% of the neurons labeled with TB from C5-C8 were double labeled with NY from L5-S1, and 35% from T7-8, which percentages resemble those of electrophysiological studies. However, in ipsilateral Nucleus Raphe Magnus about 40% of the TB-labeled neurons were double labeled from L5-S1. This percentage resembles the 66% obtained in electrophysiological studies of reticulospinal collaterals. These findings in rat support electrophysiological findings in cat and show, that rubrospinal neurons distribute their fibers primarily to the grey matter of specific groups of spinal segments, while many of the raphe spinal neurons distribute fibers throughout the spinal cord.

Animals↗

PubMedDate not supplied

Down regulation of glucocorticoid receptors in early-diagnosed rheumatoid arthritis.

OBJECTIVE: In patients with rheumatoid arthritis (RA) of longer duration, glucocorticoid receptor (GR) down-regulation has been reported without any change in cortisol levels. This phenomenon might play a role in the aetio-pathogenesis of RA. Therefore we studied GR expression, as well as the serum cortisol levels, in patients with recently diagnosed RA. METHODS: In 81 early diagnosed RA patients with disease duration < 1 year (52F/29M; mean (SD) age 63 (13) years) and in 39 age and sex matched controls (23F/16M; mean age 63 (15) years) blood samples were taken between 8-10 h AM. GR expression (GR-number and GR-affinity), serum cortisol levels, ESR, CRP, painful and swollen joints were measured. RESULTS: A significantly lower GR-number was found in the female patients compared with female controls: 7.0 versus 9.8fmol/million cells, respectively (difference: 2.8, 95% CI 1.1 - 4.6). Interestingly, also serum cortisol levels were significantly lower in the female patients compared with the female controls: 0.21 versus 0.41 micromol/l, respectively (difference: 0.20, 95% CI 0.12 - 0.28). However, between the male patients and male controls no difference was found in GR expression nor in serum cortisol levels. Neither in female nor in male patients were correlations found between GR expression and parameters of disease activity nor was there a relation between GR expression and serum cortisol levels. CONCLUSIONS: Changes in GR expression as well as serum cortisol were not a general phenomenon in early diagnosed RA patients, being present only in females and not related to disease activity. Therefore it seems unlikely that GR expression per se is causally involved in the pathogenesis of RA. We cannot preclude that it may be involved in the incidence, severity and course of RA, as this may be differentially regulated in males and females.

Adult↗

PubMedDate not supplied

Glucocorticoid receptor up-regulation in early rheumatoid arthritis treated with low dose prednisone or placebo.

OBJECTIVE: Low or medium dose prednisone in early rheumatoid arthritis (RA), albeit with significant variation in clinical efficacy, reduces the progression of joint damage. The glucocorticoid receptor (GR) number in peripheral mononuclear cells (PBMC) might be helpful to predict which patients will respond to low or medium dose prednisone and therefore do not or will not need higher doses. With this in mind we determined in a double blind, placebo controlled study at baseline and yearly the GR number in PBMC. METHODS: Eighty-one early RA patients (disease duration less than one year) were included. All patients fulfilled the ACR criteria and were disease modifying antirheumatic drugs (DMARD) and glucocorticoid-naive. They were randomly assigned to treatment with 10 mg prednisone daily or placebo. From all patients disease activity (CRP, number of tender and swollen joints), the radiological joint score, bone mineral density, and the GR number in PBMC were measured annually. RESULTS: In females the GR number was up-regulated over time in both the prednisone and the placebo group. The same trend was observed in males. No correlations were found between the GR number in the prednisone users at the start of their treatment and changes in radiological scores or bone density after 2 years of treatment. No correlations were found between the GR number at the start and the clinical characteristics after a follow-up of 2 years. CONCLUSION: The GR number in the PBMC of early RA patients did not predict which patients would be prednisone responders based on clinical or radiological parameters. However, the up-regulation of the GR number in PBMC in early RA patients towards the GR number of healthy subjects during the first two years of their disease course seems to reflect a recovery or compensatory mechanism as a response to an ongoing inflammatory process. This recovery may be not enough to efficiently control the inflammatory situation.

Adult↗