A case of adrenal insufficiency due to acquired hypothalamic CRH deficiency.

A 40-year-old woman with adrenal insufficiency was clinically diagnosed and examined with human corticotropin releasing hormone (CRH). This patient with secondary hypo-adrenalism has shown a normal serum cortisol response to exogenous ACTH administration and has been examined with CRH, lysine-vasopressin (LVP) and insulin tolerance test (ITT), respectively. Success in secreting ACTH in response to both CRH and LVP tests, but not ITT, suggests that this disorder was possibly due to a hypothalamic CRH deficiency rather than pituitary corticotroph dysfunction. A combination of the CRH test and ITT has come to play an increasingly significant role in the diagnosis and differential diagnosis of isolated ACTH deficiency syndrome.

Significance of glutathione depletion and oxidative stress in early embryogenesis in glucose-induced rat embryo culture.

Recent studies have demonstrated the protective effects of supplementing free oxygen radical scavenging enzymes against hyperglycemia-induced embryonic malformations. In this study, the glutathione (GSH)-dependent protection system in hyperglycemia-induced embryopathy was investigated. Rat embryos at the early head-fold stage (day 9.5) cultured in 66.7 mmol/l glucose for 48 h showed significant growth retardation and an increase in the frequency of malformations. The concentration of GSH and activity of the rate-limiting GSH-synthesizing enzyme, gamma-glutamylcysteine synthetase (gamma-GCS), significantly decreased in embryos exposed to hyperglycemia compared with controls (7.9 +/- 0.6 vs. 12.5 +/- 0.9 nmol/mg protein, P < 0.01 and 13.3 +/- 1.9 vs. 22.6 +/- 1.1 microU/mg protein, P < 0.01, respectively). Decreased activity of gamma-GCS in embryos exposed to hyperglycemia was associated with decreased expression of gamma-GCS mRNA levels. However, the activities of superoxide dismutase and glutathione peroxidase did not significantly change in these embryos. Extracellular and intracellular free oxygen radical formations estimated by Lucigenin-dependent chemoluminescence and flow cytometric analysis using 2',7'-dichlorofluorescein diacetate increased in isolated embryonic cells taken from embryos cultured under hyperglycemia. Supplementation of 2 mmol/l GSH ester into the hyperglycemic culture nearly restored GSH concentration in these embryos (11.9 +/- 0.5 vs. 12.5 +/- 0.9 nmol/mg protein) and reduced the formation of free oxygen radical species leading to almost complete normalization of growth retardation and embryonic dysmorphogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Overexpression of the intact thyrotropin receptor in a human thyroid carcinoma cell line.

Although thyrotropin is known to regulate thyroid cell differentiation and proliferation, human thyroid carcinoma cells are relatively insensitive or resistant to TSH stimulation. The expression levels of TSH receptor are significantly lower in carcinoma tissues than in normal tissues. Furthermore, in vitro human thyroid cell growth is not regulated by TSH itself. We, therefore, isolated neomycin-resistant stable human thyroid carcinoma cell (WRO cell) transfectants overexpressing intact human TSH receptor to evaluate the functional role of TSH receptor on carcinoma cells. Southern blot analysis confirmed incorporation and amplification of human TSH receptor complementary DNA sequences into genomic DNA. Northern gel analysis and reverse transcriptase-polymerase chain reaction analysis revealed the presence of specific TSH receptor messenger RNA (4.0 kilobases), and the specific binding and the affinity of [125I]TSH on stably transfected WRO cells were demonstrated compared to wild type. Nevertheless, impaired cAMP production to transfectants by TSH was observed. cAMP production was confirmed after stimulation of both wild type and transfectants by forskolin, cholera toxin, and isoproterenol. In contrast, TSH could affect the cytoplasmic calcium mobilization immediately after the addition of TSH to WRO transfectants. These results suggest that the impairment of TSH action on human thyroid carcinoma cells is not due to a major structural abnormality of the TSH receptor, reduction in the receptor number, or receptor affinity, but much more likely due to a TSH receptor-guanyl nucleotide-binding protein coupling defect.

Pancreatic tissue damage by transcatheter arterial embolization for hepatoma.

We analyzed the serial changes in serum pancreatic enzyme activities by transcatheter arterial embolization (TAE) in 20 hepatoma patients with liver cirrhosis in an attempt to evaluate the incidence of the pancreatic tissue damage by TAE. Serum amylase activities increased in two (10%) cases, elastase 1 levels in six (30%) cases, and trypsin and pancreatic secretory trypsin inhibitor (PSTI) levels in each of five (25%) cases. Consequently, TAE resulted in the elevation of at least more than one serum pancreatic enzyme in eight (40%) of 20 cases, although none had clinical symptoms related to pancreatitis. When the adverse effect on the pancreatic tissue was compared among 6 cases of the superselective TAE and 14 cases of the nonsuperselective TAE, which were performed from the segmental and the nonsegmental hepatic arteries, respectively, the elevation of serum pancreatic enzymes was caused only by nonsuperselective TAE, not by superselective TAE. The volumes of Spongel and Lipiodol used or the injected doses of the anticancer agent mitomycin C were not different between the two groups. These results indicate that TAE for the treatment of hepatoma frequently causes pancreatic tissue damage, and the position of the inserted catheter tip is very important to avoid the pancreatic tissue damage by TAE.

Biological activity of 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3 in the chick.

A newly synthesized fluorinated analogue of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3 (26,27-F6-1,25-(OH)2D3) has been compared with 1,25(OH)2D3 as to its biological activity in vitamin D-deficient chicks. One day-old, white Leghorn cockerels were fed a rachitogenic diet for 5 weeks. They were then given vehicle or 32.5, 130 or 325 pmol of 26,27-F6-1,25(OH)2D3 or 1,25(OH)2D3 in a solution of propylenglycol:ethanol (95:5 v/v) sc every day for 2 weeks. Twenty-four hours after the last dose, the animals were sacrificed and their femurs were removed. 26,27-F6-1,25(OH)2D3 was more active than 1,25(OH)2D3 in stimulating growth, healing of rachitic cartilage visualized by soft X-ray radiography, elevation of serum inorganic phosphorus, and mineralization of rachitic bone. These biological differences between two compounds were observed only for the dose of 130 pmol. However, this fluorinated compound has less binding ability than 1,25(OH)2D3 to fetal chick intestinal cytosol receptors. The mechanism of the higher potency of this analogue is still unknown, but its affinity to the 1,25(OH)2D3 receptor does not account for the higher activity. Since 26-hydroxylation can be postulated as the inactivation step in vitamin D metabolism, these results suggest that the reason for increased activity of this fluorinated analogue is most likely its slower metabolism.

Effect of intrahepatic arterial infusion of 131I-labelled lipiodol on hepatocellular carcinoma of rat.

Intrahepatic arterial infusion of 131I-labelled lipiodol was performed to study the intrahepatic distribution of lipiodol and to determine the radiation effect on 3'-Methyl-4-Dimethylaminobenzene (DAB) induced hepatocellular carcinoma (HCC) in rats. From the findings of the softex films and scintigrams of the liver, according to the time course, lipiodol was found to accumulate in the tumour tissues parallel with the degree of perfusion, and it remained in the tumour tissues for an extended period probably due to the delay of the degradation of lipiodol compared to that in non tumour tissues. It was noticed that the lipiodol, accumulated and deposited selectively in the tumour tissues, existed mostly in the extracellular space but not in the intracellular space. In histological studies of the resected specimens of the tumours, complete necrosis of hepatocellular carcinoma was recognized 2 to 8 weeks after the infusion of 131I-labelled lipiodol, while there was none in the control group where cold lipiodol was employed. These results suggest that the most effect on hepatocellular carcinoma in this study is caused by the radiation effect of 131I-labelled lipiodol.

Augmentation of thyrotropin responses to thyrotropin-releasing hormone following inorganic iodide.

Eight euthryoid subjects were administered 500 mug of thyrotropin-releasing hormone intravenously before and after the administration of 10 mg potassium iodide daily for 7 days. Basal serum concentrations of TSH and the response of TSH to TRH were significantly increased following iodide treatment, while serum levels of T4 and T3 did not differ significantly. It is suggested that the administration of 10 mg/day of potassium iodide can produce similar changes in serum TSH to those in previous reports using large doses of iodide.