ABSTRACT
Insulinoma-associated protein-2 (IA-2) is a transmembrane glycoprotein belonging to the tyrosine phosphatase-like protein family as well as an important autoantigen in the diagnosis of type 1 diabetes. IA-2 products have been marketed in Europe and the United States. At present, commercially available IA-2 antigens are either the recombinant IA-2ic domain or the IA-2 naturally extracted from bovine islets. However, the recombinant IA-2 antigen displays weak positive in clinic practice, which often results in occasional detection failures, thus cannot completely replace the naturally extracted IA-2 antigen. In this study, an HEK293 expression system was used to explore the production of recombinant IA-2. An IA-2 transmembrane fragment (IA-2 TMF) located at amino acid position 449-979, also known as the natural membrane protein form of IA-2, was produced in HEK293 through transfection, and both the expression conditions and dissolution conditions of the membrane protein were also optimized. The purified membrane protein yield was 0.78 mg/L cell culture. Subsequently, the antigen activity of IA-2 TMF was compared with RSR rhIA-2 through enzyme linked immunosorbent assay. The serum of 77 type 1 diabetes patients and 32 healthy volunteers were detected. Receiver operating characteristic curve (ROC) curve was used to characterize the sensitivity and specificity of the test results. The results showed that the sensitivity of IA-2 TMF was 71.4% (55/77), while the sensitivity of RSR rhIA-2 was 63.6% (49/77), and the specificity of both antigens were all 100%. There was no significant difference in specificity between the two antigens, but the sensitivity of IA-2 TMF was appreciably better than that of the imported gold standard RSR rhIA-2 antigen. In conclusion, the recombinant IA-2 TMF produced in HEK293 cells can be used as a raw material to develop in vitro diagnostic reagents for type 1 diabetes.
Subject(s)
Humans , Animals , Cattle , HEK293 Cells , Insulinoma , Diabetes Mellitus, Type 1/genetics , Recombinant Proteins , Membrane Proteins , Pancreatic NeoplasmsABSTRACT
Objective To assess and compare the incidence,clinical characteristics,treatment,and prognosis of acute heart failure patients from different grades hospitals in Beijing.Methods In this prospective internet prognosis registered study (Beijing AHF Registry),a total of 3 335 consecutive patients admitted to 14 emergency departments in Beijing from January 1st 2011 to September 23rd 2012 were enrolled.According to hospital grade,these patients were divided into two groups,349 patients were from secondary hospitals,and 2 956 patients were from tertiary hospitals.Results Among the 3 335 patients,the medium age was 71 (58,79) years,and male accounted for 53.16％.The most common underlying disease were coronary disease (43.27％),hypertension (17.73％),cardiomyopathy (16.07％) etc.The average treatment time in Emergency Department was 66.82 h.The emergency department mortality rate was 3.81％ (127 cases).The 30-day and 1-year cumulative all-cause mortality were 15.3％ and 32.27％,respectively.The 30-day and 1-year cumulative all-cause readmission were 15.64％ and 46.89％,respectively.Compared with patients in tertiary hospitals,patients in secondary hospitals had more onset acute heart failure patients (63.64％ vs.49.93％),shorter emergency department treatment time (12 h vs.41 h),lower discharge rate (3.43％ vs.37.45％) and emergency department mortality(1.58％ vs.4.09％).Compared with those in tertiary hospitals,1-year cumulative all-cause mortality (25.6％ vs.33.2％),cardiovascular disease mortality (20.2％ vs.26.0％),aggravated heart failure mortality (22.4％ vs.28.8％) were lower in secondary hospitals.Following propensity score matching,compared to tertiary hospitals,patients in secondary hospitals showed lower utilization rate of beta-blockers and ACEFARB (4.51％ vs.28.17％,1.41％ vs.9.58％),except the pironolactone.Conclusion Acute heart failure in emergency department is associated with a high mortality rate and readmission rate.There is still a big gap between guidelines recommend medication current treatments for acute heart failure.
ABSTRACT
Objective To establish the golden hamster model of buccal squamous carcinoma and observe its biological character-istics .Methods 50 golden hamster were randomly divided into two group :experiment group (n=40) and control group(n=10) . Buccal mucosa of golden hamster were daubed by exposure 4-nitroquinoline-1-oxide (4NQO) in experiment group and tap water in control group .HE staining and immunohistochemistry were used to observe the tissue sample on the 8th and 12th week .The tissue samples of golden hamster buccal-mucosa cancer were used for the in-vitro subculture .Then flat cloning formation rate ,expression of CK and Vim ,and cell karyotype were detected .Results The observations of cell morphology and biology showed that the tissue of buccal squamous carcinoma were conformed to the basic characteristics of squamous carcinoma cell in 26 golden hamster(84 .6% ) after 12 weeks .The positive rate of CK and Vim were 96 .0% by immunohistochemical staining .The Chromosomes were tetraploid karyotype .Conclusion We successfully established the golden hamster model of buccal squamous carcinoma by the daub method of 4NQO .
