Endocrine journal
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We simultaneously measured the concentrations of parathyroid hormone related peptide (PTHrP) and cytokines in synovial fluid (SF) to clarify the relationship between PTHrP and cytokine network in the SF of elderly patients with arthritis. SF was collected from knee joints of five RA patients aged 66+/-11 years old and nine osteoarthritis (OA) patients aged 80+/-9 years old. PTHrP in SF was measured by enzyme-linked immunosorbent assay (ELISA), whereas tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6) and interleukin-8 (IL-8) in SF were all measured by ELISA. ⋯ In the culture of synovial cells from RA and OA, PTHrP was produced in RA more than OA after phorbol 12-mysistate 13-acetate (TPA) stimulation. These results indicate that PTHrP and cytokines, especially IL-6, might be involved in the inflammatory processes of elderly RA and OA. This is the first study in which PTHrP and cytokine levels were simultaneously examined in synovial fluid of elderly RA and OA.
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Lipopolysaccharide (LPS) is known to stimulate the synthesis and secretion of various proinflammatory cytokines in both the peripheral immune cells and the brain. Yet, the relative contribution of peripheral and central cytokines to the LPS-induced activation of the hypothalamo-pituitary-adrenal axis is still poorly understood. In this study, utilizing the push-pull perfusion technique of the rat brain, we attempted to characterize in detail the temporal profiles of interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha after intravenous (i.v.) or intraperitoneal (i.p.) administration of LPS in both the general circulation and the hypothalamic paraventricular nucleus (PVN), which is the primary source of corticotropin releasing hormone (CRH). ⋯ LPS. Although it is possible that brain TNF-alpha, IL-6, and circulating IL-6, may be involved in the later, protracted phase of ACTH secretion induced by LPS, IL-1beta in both the brain and peripheral circulation seems to play the smallest role in ACTH secretion. This is the first study to characterize the LPS-induced temporal changes in IL-1beta, IL-6, and TNF-alpha in both plasma and PVN simultaneously in conscious, freely moving rats.
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Since amiodarone was introduced in Japan in 1992, the incidence of the drug-induced thyroid dysfunction has been increasing. We studied the thyroid function of 13 patients with amiodarone-induced thyrotoxicosis (AIT) and 11 patients with amiodarone-associated hypothyroidism (AAH) who had been referred to our Institute in the last 6 years. AIT and AAH developed after 39+/-21 and 20+/-16 months of amiodarone treatment, respectively. ⋯ Although it is postulated in Europe that there are two types of AIT, namely type I, which develops in patients with latent Graves' disease or toxic multinodular goiter, and type II, which develops in an apparently normal thyroid as destructive thyroiditis, all AIT patients we have seen so far had developed destructive type AIT. Sufficient intake of iodide and a very low incidence of toxic multinodular goiter may account for the rare incidence of type I AIT in our country. Mild to moderate AIT resolved spontaneously without discontinuing amiodarone, but it was discontinued in two of 13 AIT patients because of extrathyroidal adverse reactions.
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Comparative Study
Effect of renal denervation on phosphate excretion in endotoxemic rats.
Our previous studies showed that endotoxin (Et) administration causes hypophosphaturia in the presence of PTH. In this study, we tested the hypothesis that enhanced renal nerve activity during endotoxemia is responsible for hypophosphaturia. Two weeks after bilateral renal denervation, phosphate excretion was examined in endotoxemic Wistar rats (300 g body weight). ⋯ Fractional phosphate excretion was significantly reduced after Et challenge in innervated rats (from 24.0 +/- 3.3% to 11.8 +/- 2.2%, P<0.0001) compared to saline injection in innervated rats (from 26.9 +/- 3.9% to 33.0 +/- 1.6%). Although renal denervation improved the hypophosphaturia in comparison to the innervated rats, fractional phosphate excretion was still lower in Et-treated rats (from 28.8 +/- 5.0% to 18.0 +/- 4.7%, P<0.005) than in saline-treated rats (from 30.2 +/- 6.1% to 38.7 +/- 4.2%). In conclusion, our data did not support the hypothesis that renal nerves have an important role in reducing renal phosphate excretion during acute endotoxemia.
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We report a rare case of Cushing's syndrome due to bilateral adrenocortical adenomas in a 45-year-old female. She suffered from diabetes mellitus and hypertension for a decade, but her appearance was not Cushingoid. The plasma cortisol level in the morning was at the upper limit of the normal range, but did not show a diurnal rhythm or was suppressed by 1 mg of dexamethasone. ⋯ Magnetic resonance imaging (MRI) of the brain suggested the presence of pituitary adenoma. Prior to adrenalectomy, TSH, GH or LH showed a low response to TRH, GHRH or LHRH, respectively. Since normal responses were restored after bilateral adrenalectomy, these abnormalities were attributed to hypercortisolemia.