Determination of Residual Acrylamide in Medical Polyacrylamide Hydrogel by High Performance Liquid Chromatography tandem Mass Spectroscopy

Objective To determine residual acrylamide in medical polyacrylamide hydrogel by high performance liquid chromatography tandem mass spectroscopy （HPLC-MS）. Methods After 13C3 labeled acrylamide was added, the sample was extracted with water and then cleaned up with ExtrelutTM 20. The polyacrylamide hydrogel sample and 20 clinical cases were analyzed by HPLC-MS/MS and isotope dilution quantifying technique in selected reaction monitoring （SRM） mode. Results Acrylamide was separated from polyacrylamide hydrogel. The concentration of acrylamide in polyacrylamide hydrogel ranged from 3.9×10^-9 to 3.1×10^- 8g/L in the 20 clinical cases. The peak area was favorable linear and the range was up to 3 000 μg/L. The recovery rate was 103.1% with a relative standard deviation （RSD） of 6.20%, when the mark level was 50 lag/L. Conelusion HPLC-MS is a rapid, accurate, and sensitive method for the determination of residual acrylamide in medical polyacrylamide hydrogel.

Study on T lymphocyte subsets and NK cells in patients with Graves' disease combined with type 2 diabetes

Objective To investigate changes in T lymphocyte subsets and NK cells in patients with simple Graves’ disease(GD)and Graves’ disease combined with type 2 diabetes mellitus(GD/T2DM).Methods Fifteen cases of GD/T2DM were selected from our hospital from November 2001 to November 2004.Before and after therapy thyroid function,thyroglobulin antibody(TGA),thyroid microsomal antibody(TMA)and blood glucose level were measured,and T lymphocyte subsets(CD3,CD4,CD8,CD4/CD8)and NK cells(CD56)were measured by immunofluorescence double labeling monoclonal antibody and flow cytometry,respectively.At the same time,comparison was made with simple GD(15 cases),T2DM(15 cases)and healthy control(20 cases).Results Before therapy,CD4/CD8,CD4 and NK cells in GD/T2DM were less than normal,and there was no significant difference in comparison with simple GD(P<0.05).In T2DM group,only CD4/CD8 and CD4 were less than those of healthy controls(P<0.05).When thyroid function recovered after 1 to 3 months of methimazole treatment in both GD/T2DM and simple GD groups,various indexes recovered,which were more obvious in simple GD.Conclusion Immune hypofunction of GD may be the key to the immune abnormality of GD/T2DM,which is more significant than that of simple GD or T2DM.The recovery of thyroid function and immune abnormality is not consistent,and the recovery of GD is more significant than that of GD/T2DM.