Glucocorticoid receptor gene polymorphisms and disease activity during pregnancy and the postpartum period in rheumatoid arthritis

Introduction

The mechanism underlying the spontaneous improvement of rheumatoid arthritis (RA) during pregnancy and the subsequent postpartum flare is incompletely understood, and the disease course varies widely between pregnant RA patients. In pregnancy, total and free levels of cortisol increase gradually, followed by a postpartum decrease to prepregnancy values. The glucocorticoid receptor (GR) polymorphisms BclI and N363S are associated with relatively increased glucocorticoid (GC) sensitivity, whereas the 9β and ER22/23EK polymorphisms of the GR gene are associated with a relatively decreased GC sensitivity. We examined the relation between the presence of these GR polymorphisms and level of disease activity and disease course of RA during pregnancy and postpartum.

Methods

We studied 147 participants of the PARA study (Pregnancy-Induced Amelioration of Rheumatoid Arthritis study), a prospective study investigating the natural improvement during pregnancy and the postpartum flare in women with RA. Patients were visited, preferably before pregnancy, at each trimester and at three postpartum time points. On all occasions, disease activity was scored by using DAS28. All patients were genotyped for the GR polymorphisms BclI, N363S, 9β, and ER22/23EK and divided in groups harboring either polymorphisms conferring increased GC sensitivity (BclI and N363S; GC-S patients) or polymorphisms conferring decreased GC sensitivity (9β or 9β + ER22/23EK; GC-I patients). Data were analyzed by using a mixed linear model, comparing GC-S patients with GC-I patients with respect to improvement during pregnancy and the postpartum flare. The cumulative disease activity was calculated by using time-integrated values (area under the curve, AUC) of DAS28 in GC-I patients versus GC-S patients. Separate analyses were performed according to the state of GC use.

Results

GC-S patients treated with GC had a significantly lower AUC of DAS28 in the postpartum period than did GC-I patients. This difference was not observed in patients who were not treated with GCs. During pregnancy, GC-S and GC-I patients had comparable levels of disease activity and course of disease.

Conclusions

Differences in relative GC sensitivity, as determined by GR polymorphisms, are associated with the level of disease activity in the postpartum period in GC-treated patients, but they do not seem to influence the course of the disease per se.     

Effects of age,replicative lifespan and growth rate of human nucleus pulposus cells on selecting age range for cell-based biological therapies for degenerative disc diseases

Autologous disc cell implantation, growth factors and gene therapy appear to be promising therapies for disc regeneration. Unfortunately, the replicative lifespan and growth kinetics of human nucleus pulposus (NP) cells related to host age are unclear. We investigated the potential relations among age, replicative lifespan and growth rate of NP cells, and determined the age range that is suitable for cell-based biological therapies for degenerative disc diseases. We used NP tissues classified by decade into five age groups: 30s, 40s, 50s, 60s and 70s. The mean cumulative population doubling level (PDL) and population doubling rate (PDR) of NP cells were assessed by decade. We also investigated correlations between cumulative PDL and age, and between PDR and age. The mean cumulative PDL and PDR decreased significantly in patients in their 60s. The mean cumulative PDL and PDR in the younger groups (30s, 40s and 50s) were significantly higher than those in the older groups (60s and 70s). There also were significant negative correlations between cumulative PDL and age, and between PDR and age. We found that the replicative lifespan and growth rate of human NP cells decreased with age. The replicative potential of NP cells decreased significantly in patients 60 years old and older. Young individuals less than 60 years old may be suitable candidates for NP cell-based biological therapies for treating degenerative disc diseases.     

Somatostatin receptor imaging in vivo localization of tumors with a radiolabeled somatostatin analog

This paper presents the results of the visualization of somatostatin (SS) receptor positive tumors in man after the i.v. administration of the SS analog Tyr³-octreotide coupled to ¹²³I. It is an easy, quick and harmless procedure which allows imaging of primary and (often unexpected) secondary deposits and/or multiple localizations of the majority of endocrine pancreatic tumors, metastatic carcinoids and pituitary tumors, as well as of a multitude of humors with neuroendocrine characteristics and well-differentiated brain tumors and meningiomas. In the case of hormone-secreting tumors a positive scan in most instances also predicts the subsequent successful therapy with octreotide.     

Selenium,Lead, and Cadmium Levels in Renal Failure Patients in China

Whole blood and serum samples of Chinese stable chronic renal failure (CRF) patients (n = 81), hemodialysis patients (n = 135), posttransplant patients (n = 60), and subjects with normal renal function (NRF; N = 42) were collected, as well as water and dialysate samples from five dialysis centers. The concentration of selenium (Se), lead (Pb), and cadmium (Cd) was measured by atomic absorption spectrometry. The mean serum Se levels in patients with different degrees of renal failure were significantly lower than those of subjects with NRF (p < 0.01). Pb levels were not increased in renal failure patients, while the Cd levels in patients with various degrees of renal failure were higher than in subjects with NRF (p < 0.05). After correcting the results of Pb and Cd for hematocrit (Hct) however, Pb levels of dialysis patients were also increased. In the dialysis population under study, blood Pb and Cd levels were closely related to the time on dialysis, while contamination of the final dialysate may also contribute to the increased blood Cd and to a less extent Pb levels. Correction for Hct may be recommended to accurately compare blood Pb and Cd levels in dialysis patients and CRF patients with varying degrees of anemia to those of subjects with NRF.     

Preembedding colloidal gold immunostaining of hypothalamic neurons: light and electron microscopic localization of beta-endorphin-immunoreactive perikarya

A preembedding immunogold staining (IGS) procedure was developed to identify beta-endorphin/adrenocorticotropic hormone immunoreactive neurons at the light and electron microscopic levels. Colchicine-treated rats were perfused with Nakane's periodate-lysine-paraformaldehyde fixative. Vibratome sections were incubated in primary antisera followed by goat anti-rabbit immunoglobulin G coupled to 16 nm colloidal gold, and, in some cases, rabbit immunoglobulin G coupled to gold. The appearance to pink to light red perikarya, corresponding to colloidal gold deposition at antigenic sites, was monitored under the light microscope. Positive cell bodies in the arcuate region sometimes extended lateral to the nucleus. Only proximal portions of neuronal processes were stained. At the ultrastructural level, colloidal gold labeled the periphery of 90-110 nm dense neurosecretory granules in the perikaryal cytoplasm and a few proximal axons. Clusters of gold particles, appearing free in the neuroplasm, actually labeled secretory granules in adjacent thin sections. Granules associated with the Golgi apparatus were not stained. Colloidal gold labeling of mature beta-endorphin granules, but not progranules, in rat hypothalamic neurons was confirmed using the peroxidase-antiperoxidase technique. The results correlate well with data on the intracellular processing of pro-opiomelanocortin in pituitary cells and prepropressophysin in the paraventricular nucleus. These data demonstrate the first application of the preembedding colloidal gold staining method for the identification of intracellular antigens within the central nervous system. The IGS method provides a definitive marker for single or double labeling of nervous tissue at both the light and electron microscopic levels.     

High concentrations of catecholamines selectively diminish the sensitivity of CRF-stimulated ACTH release by cultured rat pituitary cells to the suppressive effects of dexamethasone

ACTH-release by primary cultures of rat anterior pituitary cells in response to CRF, vasopressin, epinephrine, norepinephrine and VIP is readily suppressible by dexamethasone. Rat hypothalamic extract-induced ACTH release is less sensitive to the inhibitory effect of dexamethasone than that elicited by CRF and the other secretagogues mentioned above. In studying the additive and potentiating effect on ACTH release of CRF in combination with vasopressin, VIP and the catecholamines it became evident that only the combination of micromolar concentrations of epinephrine or norepinephrine together with nanomolar concentrations of CRF will make ACTH release significantly less sensitive to the suppressive effect of dexamethasone. Other combinations of CRF and vasopressin or CRF and VIP will render ACTH release as suppressible to dexamethasone, as that elicited by each of these compounds by itself. This observation in the rat might explain at least in part the observation that a diminished suppressibility of the pituitary-adrenal axis to dexamethasone can be found in patients with psychiatric disease, especially depression.     

The met-enkephalin analog FK 33-824 directly inhibits ACTH release by the rat pituitary gland in vitro

Systematic administration of the enkephalin analog FK 33-824 was previously shown to stimulate PRL secretion and to inhibit ACTH secretion in man. Naloxone prevented the effect on PRL release, but not on ACTH release. In this study, the direct action of this analog on hormone release by rat anterior pituitary lobes $\text{in}$$\text{vitro}$ were investigated. 1 uM FK 33-824 inhibited basal ACTH secretion by anterior pituitary glands in vitro, while 0.1 uM and 1 uM attenuated the lysine vasopressin stimulated ACTH release. Naloxone did not reverse the inhibitory action of the analog on ACTH release. β-Endorphin (0.01 - 1 uM) did not directly affect ACTH release. Basal and dopamine-induced inhibition of PRL release by anterior pituitary glands was neither influenced by FK 33-824 (0.1 and 1 uM), nor by β-endorphin (0.1 and 1 uM) with or without bacitracin. This study shows that the long-acting met-enkephalin analog FK 33-824 differentially affects PRL and ACTH secretion by the pituitary gland. It seems to stimulate PRL release at a suprapituitary site and this action probably involves u opiate receptors, because naloxone prevents these stimulatory effects. The inhibitory effect of FK 33-824 on ACTH release, however, is mediated via a direct effect at the pituitary level, which does not involve u receptors, as naloxone did not prevent this effect. In this respect, its action differs from that of β-endorphin, which does not directly affect ACTH release by the anterior pituitary gland.     

Lack of association between five polymorphisms in the human glucocorticoid receptor gene and glucocorticoid resistance

Glucocorticoid resistance due to mutations in the gene for the glucocorticoid receptor has been suggested to be more common than is thought at present, owing to the relative mildness of its symptoms and the difficulty of its diagnosis. To investigate the prevalence of mutations in the glucocorticoid receptor gene responsible for relative insensitivity to glucocorticoids, we carried out polymerase chain reaction/single-strand conformation analysis of the glucocorticoid receptor gene in a group of 20, otherwise healthy, persons with a reduced response in a dexamethasone suppression test and in 20 controls. We did not find mutations or polymorphisms associated with a reduced sensitivity to glucocorticoids. However, we identified five novel polymorphisms in the gene for the human glucocorticoid receptor, which may be useful in analyzing whether loss of (part of) the glucocorticoid receptor gene plays a role in glucocorticoid-resistant malignancies. Although relative resistance to glucocorticoids seems to be rather frequent in otherwise healthy persons, it is not usually associated with mutations or polymorphisms in the glucocorticoid receptor gene. Received: 17 July 1996 / Revised: 26 November 1996     

Somatostatin cells in rat antral mucosa: qualitative and quantitative ultrastructural analyses in different states of gastric acid secretion

Summary In the gastrointestinal tract somatostatin is localized in endocrine cells and in neurons. The antral somatostatin (D-) cell shares features of both cell types. The activity of the antral D-cell is regulated by intragastric pH. Therefore different states of gastric acidity were induced experimentally in order to study D-cell morphology at the electron microscopical level. The morphological findings were related to measurements of plasma and tissue concentrations of the peptide. The D-cell is characterized by extensive membrane interdigitations with neighbouring cells. Changes in the activity of antral D-cells are reflected by an increase in cytoplasmic secretory granule density and a shift of secretory granules towards basal cell processes. Direct endocrine cell contacts at the level of the perikarya were rarely observed. The intracellular distribution of secretory granules suggests that cell communication is more likely to take place at the level of the strongly immunoreactive cytoplasmic processes. No evidence for endocrine or exocrine (luminar) secretion was observed morphologically. This is in agreement with the concept of paracrine secretion of the antral D-cell.     

Arterial wall damage by X-rays and fast neutrons.

Radiation-induced atheromatosis has been studied for 200 kVp X-rays and 15 MeV neutrons. From the results of two earlier experiments, a r.b.e. less than 1 was expected for neutrons. (1) Irradiation of blood-vessels causes depolymerization of the mucopolysaccharides in the vessel wall, resulting in atheromatosis, and (2) in two other mucopolysaccharide systems a r.b.e. less than 1 is observed for fast neutrons. Irradiation of the carotid arteries of a total number of 120 hypercholesterolaemic rabbits, divided over several groups, with 500 and 1000 rad of X-rays or neutrons results, however, in atheromatous plaques which are more pronounced for neutrons than for X-rays at the 500 rad dose-level; for a dose of 1000 rad the effect of neutrons is less extensive than the effect of X-rays. These results lead to the assumption that the origin of the atheromatosis seems not only to be the mucopolysaccharide depolymerization, but that radiation induced damage at the cellular level must be taken into account.