ENZYMO-ROCKET ELECTROPHORETIC ASSAY AND CROSSED AFFINITY ENZYMOIMMUNOELECTROPHORESIS AND ITS APLICATION IN DIAGNOSIS OF PLIMARY LIVER CANCER

A senitive and accurate quantitative method of alphafetoprotein(AFP), enzymo-rocket electrophoretic assay (EREA), was developed by introducing horseradish peroxidase-labeled anti-human AFP antibody into rocket electrophoresis.The lower limit of quantitation ty this method is about 10 ng/ml of AFP.The dose-response curve covers a broader range of concentrations of AFP (10-4000ng/ml)than RIA(0-400 ng/ml) .The accuracy and precision of comparable to that of RIA(r=0.986).Serum AFP measured in 100 patients with primary liver cancer by this method,88% had levels over 25ng/ml.The crossed affinity enzymoimmunoelectrphoresis is a combination of lentil lectin(LCA)affinity electrophoresis and enzymo-rocket electrophoresis,it has been possible to separate the AFP into two variants,LCA-reactive(LCA-R)and LCA-nonreactive (LCA-N)fractions.The advantages of this method are high sensitivity,rapid(6-7h),and can be effectively used to differentiate the primary liver cancer and benign liver disease.

Modulation of the activation of Statl by the interferon-gamma receptor complex

The activation of Statl by the interferon-gamma （IFN-γ） receptor complex is responsible for the transcription of a significant portion of IFN-γ induced genes. Many of these genes are responsible for the induction of an apoptotic state in response to IFN-γ. In the absence of Stat 1 activation, IFN-γ instead induces a proliferative response. Modifying Stat 1 activation by IFN-γ may have pharmacological benefits. We report that the rate of activation of Statl can be altered in HeLa cells by overexpressing either the IFN-γ R1 chain or the IFN-γ R2 chain. These alterations occur in hematopoietic cell lines： Raji cells and monocytic cell lines, which have average and above-average IFN-γ R2 surface expression, activate Statl similarly to HeLa cells and HeLa cells overexpressing IFNγR2, respectively. The rapid Statl activation seen in HeLa cells can be inhibited by overexpressing a chimeric IFN-γR2 chain that does not bind Jak2 or （when high concentrations of IFN-γ are used） by overexpressing IFN-γR1. These data are consistent with a model in which the recruitment of additional Jak2 activity to a signaling complex accelerates the rate of Statl activation. We conclude that the rate of activation of Statl in cells by IFN-γ can be modified by regulating either receptor chain and speculate that pharmacological agents which modify receptor chain expression may alter IFN-γ receptor signal transduction.

Decline in the expression of IL-2 after trauma and changes in the nuclear transcription factors NFAT and AP-1

OBJECTIVE: To investigate whether the decrease in expression of interleukin-2 (IL-2) after trauma is associated with changes in DNA binding activity of nuclear factor of activated T cells (NFAT) and activator protein-1 (AP-1). METHODS: Mice with closed impact injury with fracture in both hind limbs were adopted as the trauma model. Spleen lymphocytes were isolated from traumatized mice and stimulated with Con-A. Culture supernatants were assayed for IL-2 activity, and total RNA was extracted from spleen lymphocytes and assayed for IL-2 mRNA. DNA binding activity of NFAT and AP-1 were measured by electrophoretic mobility shift assay (EMSA). The expression of c-Fos, c-Jun and JunB proteins was determined by the Western blot analysis. RESULTS: DNA binding activity of NFAT and AP-1 gradually decreased to a minimum of 41% and 49%, respectively, of the control on the 4th day after injury, which was closely followed by the decline in IL-2 activity and IL-2 mRNA. A decrease in the expression of c-Fos on the 1st and 4th day after trauma had no significant effect on c-Jun expression; the increase in expression of JunB was only on the 1st day after injury. CONCLUSION: Decreased IL-2 expression is, at least in part, due to a decline in the activation of NFAT and AP-1 in traumatized mice. The decline in DNA binding activity of NFAT and AP-1 is partly due to a trauma-induced block in the expression of c-Fos.

Polymorphisms and functions of the aldose reductase gene 5' regulatory region in Chinese patients with type 2 diabetes mellitus

OBJECTIVE: To screen the 5' regulatory region of the aldose reductase (AR) gene for genetic variabilities causing changes in protein expression and affecting the promoter function. METHODS: The screenings were carried out by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). All SSCP variants were submitted for DNA sequencing and inserted into the plasmid chloromycetin acetyl transferase (CAT) enhancer vector. The constructs were used to transfect Hela cells, and CAT assays were performed to assess promoter activity. Gel mobility shift and footprinting assays were also performed to determine the interaction between the DNA and nuclear proteins. RESULTS: Two polymorphisms, C (-106) T and C (-12) G, were identified in the regulatory region in 123 Chinese control subjects and 145 patients with type 2 diabetes mellitus. The frequencies of genotypes WT/WT, WT/C (-12) G and WT/C (-106) T were not significantly different between the subjects and patients. In the patients with and without retinopathy, frequencies of WT/C (-106) T were 31.5% and 17.5% (P 0.05) respectively. The total frequency of WT/C (-12) G and WT/C (-106) T in patients with retinopathy was 41.8%, significantly higher than that (20.0%) in patients without retinopathy (P