A new method to induce myasthenia gravis models and the protective effect of soluble decay accelerating factors

It is expensive to induce experimental autoimmune myasthenia gravis (EAMG) by active immunity, and difficult to obtain natural acetylcholine receptor (AChR). We sought a new method of inducing EAMG by immunizing rats with artificially synthesized AChR. The AChR mRNA in TE671 cells was extracted and reverse transcribed. The inclusion body was purified and protein concentration was determined, and the EAMG animal model was used for induction. The serum was extracted from rat blood. The antibody titer was determined using enzyme-linked immunosorbant assay (ELISA). The concentration of decay accelerating factor (DAF) in the rat serum was determined by ELISA, and the metabolism of serum rDAF was determined by western blot. We evaluated the inhibition of rDAF by determining the 50% complement hemolysis unit in the rat serum. The extracellular domain (ECD) nucleotide sequence clone produced by polymerase chain reaction was completely consistent with that in the human gene bank; it was induced by isopropyl β-D-1-thiogalactopyranoside to express the protein after insertion into vector pET16b. Sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that the inclusion body protein was the exact target. The ECD protein was able to bind with mAb35 after dialysis and renaturation, which demonstrated protein activity. The soluble ECD protein was used to immunize rats and obtain the EAMG models. The inhibitory effect of the complement was unsatisfactory owing to high decay rate after rDAF injection into the EAMG models. It is easy to induce the EAMG model by obtaining the AChRTEα1 subunit ECD protein using the substitution method.

[Angiotensin II induced myocardial hypertrophy in neonatal rats could be attenuated by activated κ-opioid receptor via modulating the calcineurin signal pathways]

OBJECTIVE

To observe the effect of κ-opioid receptor (κ-OR) stimulation on Angiotensin II (Ang II)-induced cardiomyocyte hypertrophy in vitro cultured myocardial cells from neonatal rats and on calcineurin (CaN) signal pathways.

METHODS

Cultured myocardial cells of neonatal rats were divided into control group, CSA (1 µmol/L) group, Ang II (1 µmol/L) group, Ang II (1 µmol/L) + U50488H (1 µmol/L) group, Ang II (1 µmol/L) + CSA (1 µmol/L) group, Ang II (1 µmol/L) + Rp-cAMPS (1 µmol/L) group, Ang II (1 µmol/L) + CSA (1 µmol/L) + U50488H (1 µmol/L) group and Ang II (1 µmol/L) + PTX5 mg/L + U50488H (1 µmol/L) group. The hypertrophic myocytes were induced by Ang II 1µmol/L before κ-OR agonist U50488H 1 µmol/L was administered. The antihypertrophic effect of κ-OR stimulation was observed in the presence of ciclosporine A (CsA) 1 µmol/L, cAMP triethyl-ammonium salt (Rp-cAMPS) 1 µmol/L, and pertussistoxin ( PTX) 5 mg/L. The total protein content was assayed by the method of Lowry. The [Ca²⁺]i was measured by confocal microscope using Fluo-3/AM as flouresecent indicator. The relative expression of CaN was determined by Western blot.

RESULTS

(1) The total protein content of Ang II group was significantly higher than that in control group (P<0.01), which could be equally reduced by cotreatment with U50488H, CSA and Rp-cAMPS (P<0.01). Total protein content of the Ang II + PTX + U50488H group and the Ang II group was similar. (2) The [Ca²⁺]i was significantly higher in Ang II group of neonatal rat cardiomyocytes than that in control group (P<0.01), which could be reduced by cotreatment with U50488H, CSA and Rp-cAMPS (P<0.01). [Ca(2+)]i was similar between the Ang II + PTX + U50488H group and the Ang II group. (3) The expression of CaN was significantly higher in Ang II group than that in control group (P<0.01), which could be significantly reduced by cotreatment with U50488H, CSA and Rp-cAMPS (P<0.01). CaN was similar between the Ang II + PTX + U50488H group and the Ang II group.

CONCLUSION

κ-opioid receptor activation could attenuate Ang II induced cardiomyocytes hypertrophy via reducing [Ca²⁺]i and downreglating CaN.

Prevalence and awareness of diabetes mellitus among a rural population in China: results from Liaoning Province

AIM

To clarify the diabetes prevalence trends among the rural population in northern China.

METHODS

All eligible permanent residents aged ≥ 35 years in selected rural villages of Liaoning province were invited to participate in the study. A total of 11 600 people completed all questionnaires and were included in the study. The response rate was 85.3%. Fasting plasma glucose levels were measured after at least 12 h of fasting and diabetes was diagnosed according to WHO criteria, i.e. fasting plasma glucose ≥ 7 mmol/l and/or being on treatment for diabetes. Impaired fasting glucose was defined according to the 1997 and the 2010 American Diabetes Association (ADA) criteria (6.1-6.9 and 5.6-6.9 mmol/l, respectively). Previous diagnoses of diabetes were assessed on the basis of self-reports.

RESULTS

The prevalence of diabetes among adults in the rural population was 10.6% (10.0% in men and 11.1% in women). The prevalence of impaired fasting glucose was 13.0 and 36.1% according to the 1997 and the 2010 ADA criteria, respectively. The prevalence of previously diagnosed diabetes was 4.3% among the whole population (3.3% in men and 5.1% in women). The prevalence of previously diagnosed diabetes was 34.8% in men and 50.2% in women. Only 29.6% of men and 42% of women with diabetes had taken oral hypoglycaemic agents or insulin to lower their blood sugar. In multivariate analysis, age, drinking habits, BMI, dyslipidaemia and family history of diabetes were identified as independent risk factors for diabetes, and occupational physical activity, smoking and lean meat intake were identified as independent protective factors for diabetes.

CONCLUSIONS

The prevalence of diabetes and impaired fasting glucose were found to be high in this rural population. Although the rate of treatment of people with diabetes has increased, the glycaemic control rate was still at a low level.

Calcitriol does not significantly enhance the efficacy of radiation of human cervical tumors in mice

OBJECTIVE

Calcitriol can enhance the sensitivity of cancer cells to radiation in vitro. The authors aimed to investigate the potential synergistic effect of calcitriol and radiation in a xenograft mouse model of human cervical cancer.

MATERIALS AND METHODS

Tumor-bearing mice were fed with vehicle arachis oil or 2.5 µg/kg calcitriol daily for 15 consecutive days. Some mice received ten Gy radiation on day 7 post treatment. Tumor growth was monitored, and the tumor tissues were examined by histology and electron microscopy.

RESULTS

Treatment with either calcitriol or radiation significantly inhibited the growth of implanted cervical cancers (p < 0.05 vs. control) and increased the number of dead tumor cells in the tumor sections. However, there was no significant difference in the tumor weights between the mice with radiation alone and both radiation and calcitriol treatment.

CONCLUSION

Calcitriol had anti-tumoral activity, but failed to enhance the efficacy of radiation in human cervical cancers.

Distinguishing immunorelated haemocytopenia from idiopathic cytopenia of undetermined significance (ICUS): a bone marrow abnormality mediated by autoantibodies

In recent years we have observed that some patients with idiopathic cytopenia of undetermined significance (ICUS) responded well to corticosteroid and high-dose intravenous immunoglobulin treatment, indicating that some cytopenia in ICUS might be mediated by autoantibodies. In this study, we analysed 166 ICUS cases retrospectively, some of which were autoantibodies detected on haemopoietic cells in bone marrow (BM) by BM mononuclear cell (BMMNC)-Coombs test, flow cytometry (FCM), Western blot and immunofluorescence (IF). We found that 25·9% (43 of 166) of the cases had autoantibodies positive verified with BMMNC-Coombs test or FCM analysis, 72·1% (31 of 43) of whom had immunoglobulin (Ig)G autoantibody positive by Western blot. IgG could be detected in the erythroblastic islands on the BM smear of nine (32·1%, nine of 28) ICUS patients with autoantibodies by IF. Of these 43 patients, the median percentage of reticulocytes was 1·79%. More than half the patients had hyper-BM cellularity with a higher percentage of nucleated erythroid cells in the sternum. Total response rates to immunosuppressive therapy at 6, 12, 24 and > 36 months were 46·5% (20 of 43), 75% (30 of 40), 77·4% (24 of 31) and 66·7% (16 of 24), respectively. We termed this group of ICUS cases with autoantibodies as immunorelated haemocytopenia (or BMMNC-Coombs test-positive haemocytopenia).

Screening for key genes associated with invasive ductal carcinoma of the breast via microarray data analysis

The aim of this study was to identify key genes related to invasive ductal carcinoma (IDC) of the breast by analyzing gene expression data with bioinformatic tools. Microarray data set GSE31138 was downloaded from Gene Expression Omnibus, including 3 breast cancer tissue samples and 3 normal controls. Differentially expressed genes (DEGs) between breast cancer and normal control were screened out (FDR < 0.05 and |logFC| > 2). Coexpression between genes was examined with String, and a network was then constructed. Relevant pathways and diseases were retrieved with KOBAS. A total of 56 DEGs were obtained in the IDC of the breast compared with normal controls. A gene coexpression network including 27 pairs of genes was constructed and all the genes in the network were upregulated. Further study indicated that most of the genes in the coexpression network were enriched in ECM-receptor interaction (COL4A2, FN1, and HMMR) and nucleotide excision repair (CETN2 and PCNA) pathways, and that the most significantly related disease was autoimmune lymphoproliferative syndromes. A number of DEGs were acquired through comparative analysis of gene expression data. These findings are beneficial in promoting the understanding of the molecular mechanisms in breast cancer. More importantly, some key genes were revealed via gene coexpression network analysis, which could be potential biomarkers for IDC of the breast.