Objective To investigate the relationship between the degree of serum cortisol suppression by low-dose dexamethasone (1 mg) and full serum cortisol suppression (suppression rate > 50% ) by high-dose dexamethasone (8 mg) in patients with Cushing syndrome, and to evaluate these tests in Cushing disease. Methods Ninty-one patients with Cushing syndrome were studied retrospectively. The relationship of 20%, 30%, 40%, and 50% cortisol suppression by overnight 1mg dexamethasone with full serum cortisol suppression by overnight 8 mg dexamethasone was analyzed, and the sensitivity and specificity in the diagnosis of Cushing disease were evaluated. Results The degree of cortisel suppression during overnight 1 mg dexamethasone suppression test was correlated with that during overnight 8 mg dexamethasone suppression test (r=0. 649,P<0. 001 ). 30, 22, 13, and 9 patients had greater than 20%, 30%, 40%, and 50% serum cortisol suppression respectively during overnight 1 mg dexamethasone suppression test. Among them, 23 ( 76. 7% ), 20 (90. 9% ), 12 (92.3%), and 9 ( 100.0% )patients had full serum cortisol suppression during overnight 8 mg dexamethasone suppression test. The sensitivity of the cutoff of greater than 20%, 30%, 40%, and 50% serum cortisol suppression for the diagnosis of Cushing disease was 52.8%, 32.7%, 22.6%, and 15.7%, and the specificity was 94.7%, 94.7%, 97.4%, and 97.4% respectively. Conclusions In patients with Cushing syndrome, greater than 20% serum cortisol suppression during overnight 1 mg dexamethasone suppression test is usually associated with full serum cortisol suppression during overnight 8 mg dexamethasone suppression test, and most of them are finally diagnosed as Cushing disease.

AIM: To study the culture and characteristics of mouse adult bone marrow-derived pluripotential mesenchymal stem cells and its potential to differentiate into insulin secretion cells. METHODS: Cells were plated on 60% DMEM-LG and 40% MCDB-201 medium supplemented with 2% fetal calf serum and 10 ?g/L PDGF-BB, 10 ?g/L EGF and 1?10~6 U/L LIF. The proliferation rate, phenotype and oct-4 mRNA were tested. After it was plated on serum-free medium DMEM/F12 with GLP-1 and nicotinamide, the nkx2.2 ngn3, pdx-1 and insulin 2 mRNA were tested. RESULTS: The cells were round with large nucleus and scant cytoplasma. They were CD13~+, CD44~-, CD45~- and MHCⅡ~-. Oct-4 mRNA were present. The nkx2.2 pdx-1 and insulin 2 mRNA were presented in cells plated on the inducing medium at 14 days. CONCLUSION: The adult bone marrow-derived pluripotent stem cells were cultured and they has the possibilities to be induced into insulin-secreting cells.

AIM: To compare the effects of three different cell culture protocols: embryonic body(EB) formation,EB formation-monolayer and monolayer on differentiation of mouse embryonic stem(ES) cells into insulin-secreting cells.METHODS: E14.1 mouse ES cells were treated with GLP-1,betacellulin,activin A,bFGF and nicotinamide by using EB formation,EB formation-monolayer and monolayer culture protocol respectively for 30 days,then insulin expression was examined by RT-PCR,DTZ-staining and immunohistochemistry.The percentage of insulin-secreting cells was evaluated by flow cytometry.RESULTS: DTZ-staining positive cells and insulin immunohistochemical staining positive cells were observed in the differentiated cells for all the three groups.mRNAs of insulin and some other islet-related genes were detected,insulin expression was the strongest in EB formation-monolayer,and the weakest was in monolayer.The percentage of insulin-positive cells of the differentiated cells in the EB formation-monolayer group was higher than that in the EB formation group(P

Overexpression of survivin may partly protect the NIT-1 cells(mouse insulin-secreting cells) from cytokine-induced apoptosis.In addition, NIT-1 cells transfected with survivin had an slightly improved response of insulin secretion to glucose stimulation.

Objective Plasma renin concentration (PRC) offers advantages in processing and standardization as compared with plasma renin activity (PRA). The aim of the study is to compare the sensitivity and specificity of plasma aldosterone concentration ( PAC)/PRA (ARR) and PAC/PRC (AARR) in screening primary aldosteronism ( PA ) in hypertensive patients and to observe the influence of different postures on PRC and AARR. Method ( 1 ) PAC and PRC in the supine position and after 1-hour and 2-hour upright posture were determined in 28 patients with PA and 51 patients with essential hypertension. The diagnostic efficacies during different postures were compared according to the ROC curve analysis. (2) 31 patients with PA, 242 patients with essential hypertension, and 145 normotensitive subjects were recruited in the study. The diagnostic efficacy of AARR in screening PA from hypertensive patients was evaluate. PAC, PRA, and PRC were measured by radioimmunoassay. Results ( 1 ) The AUC of AARR in the supine position, 1-hour and 2-hour upright posture were0.950 (95% CI0.906-0.994, P<0. 01), 0.979 (95% CI0.956-1.000, P<0.01) and 0.917 (95% CI 0. 856-0. 979, P<0. 01 ) respectively. AARR of 1 -hour upright yielded the highest screening efficiency. ( 2 ) The correlation coefficient index of Log-PRA and Log-PRC was 0. 705 ( P< 0. 01, n = 418 ), whereas the correlation coefficient index of Log-ARR and Log-AARR was 0.705 (P<0.01, n=418). The AUC of ARR and AARR were 0.998 (95% CI0. 981-1. 000, P<0.01 ) and 0.957 (95% CI0. 929-0.985, P<0.01 ) respectively according to the ROC curve. The optimal cutoff of AARR during upright 1 hour was 42.36 ng · dl-1/ng ·dl-1 ( sensitivity 87.10%, specificity 93.75% ). Conclusion The screening efficacy of AARR in screening PA in hypertensive patients was comparable with ARR. AARR measured after keeping upright 1 hour yielded the highest screening efficiency. The optimal cutoff of AARR was 42.36 ng · dl-1/ng ·dl-1.

Syndrome of resistance to thyroid hormone(RTH)is a rare hereditary thyroid disease with various clinical manifestations and laboratory findings. RTH could be misdiagnosed and mistreated, resulting in aggravation of the disease. We reviewed the medical records of a patient with RTH over the past six years. In addition, we provided a summary of latest progress for RTH to help the clinicians to improve the understanding of the disease.