Amyloid fibrils belong to a category of abnormal aggregations of natural proteins, which are closely related to many human diseases. Recently, some critical peptide sequences have been extensively studied for clarifying the molecular mechanism of natural proteins to form amyloid fibrils. In the present study, we designed a short peptide GGAAVV (GAV-6) composed of hydrophobic amino acids glycine (G), alanine (A) and valine (V) and studied its ability to form amyloid fibrils. As characterized by atomic force microscopy (AFM) and dynamic light scattering (DLS), the peptide could self-assemble into smooth nanofibers without branches. Congo red staining/binding and thioflavin-T (ThT) binding experiments show that the nanofibers formed by GAV-6 shared identical properties with typical amyloid fibrils. These results show that the designed peptide GAV-6 could self-assemble into typical amyloid fibrils, which might make it a useful model molecule to clarify the mechanism for the formation of amyloid fibrils in the future.
Amino Acid Sequence ; Amyloid ; chemistry ; Humans ; Microscopy, Atomic Force ; Models, Molecular ; Nanofibers ; chemistry ; Peptides ; chemistry

AIM: To evaluate the effect of staphylococcal enterotoxin B (SEB) or staphylococcal enterotoxin C (SEC) combining with dendritic cells (DC) on T cell functions and in vitro anti-HcaF tumor cytotoxicity of activated T cells. METHODS: S-100 protein expression in DC was detected by immune histochemistry staining. The expressions of I-E~? and CD80 molecules on DC, the expression of CD69 molecule on T cells and the production of IL-2 and TNF-? by T cells were determined with flow cytometry. The proliferation of T cells and its cytotoxicity to HcaF tumor cells were detected by MTT assay. RESULTS: In vitro experiments showed that isolated DC expressed high level of S-100 protein. SEB or SEC-induced DC highly expressed I-E~? and CD80 molecules and that SEB or SEC-induced DC promoted the activation and proliferation of T cells. 100 ?g/L of SEB or SEC was the most effective concentrations to induce T cells to secret IL-2 and TNF-?. The T cells activated by SEB or SEC combined with DC showed significant cytotoxicity to HcaF cells, appearing a stronger role than tumor antigen combined with DC. There was no difference in the role for T lymphocytes between both SEB and SEC. CONCLUSIONS: The results indicate that SEB or SEC combined with DC is an effective way to enhance T cell functions, producing stronger cytotoxicity to HcaF tumor cells than tumor antigen-loaded DC used at present, which offers a forceful evidence for the possibility of superantigen SEB or SEC combining with DC to be applied to clinical tumor immunotherapy.

Objective To investigate the changes of peripheral blood T cell subsets and serum soluble interleukin-2 receptor (sIL-2R),vascular endothelial growth factor (VEGF) and LDH in patients with diffuse large B cell lymphoma,and to investigate their relationship of the cellular immune function,clinical stage and disease progression.Methods 35 cases of DLBCL patients were selected as observe group,20 cases of healthy individuals as normal control group.Peripheral blood T cell subsets were detected by flow cytometry.Serum soluble interleukin-2 receptor (sIL-2R) and vascular endothelial growth factor (VEGF) were detected by ELISA assay.Serum levels of LDH were detected by the rate method for measuring.Results The expression levels of CD4,NK cells and CD4/CD8 ratios in all patients with DLBCL were lower than healthy individuals [(68.62±12.82) ％ vs(73.00±6.12) ％,(14.28±7.93) ％ vs (39.49±12.01) ％,(1.03±0.84) vs (1.45±0.28),all P ＜ 0.05].Serum sIL-2R in patients with DLBCL was significantly higher than healthy individuals [(501.50±157.70).μg/L vs (128.30±82.40) μg/L,P＜ 0.001].Serum levels of sIL-2R with Ⅲ-Ⅳ stage in patients with DLBCL was higher than that in ones with Ⅰ-Ⅱ stage [(618.38±192.22) μg/L vs (432.45±75.48)μg/L,P ＜ 0.05].Serum expression levels of sIL-2R in patients with DLBCL with B symptoms was higher than that in ones with A symptoms [(616.50±183.03) μg/L vs (441.52±103.48) μg/L,P ＜ 0.01].The expression levels of VEGF,LDH in patients with DLBCL were higher than healthy individuals [(304.03±163.05) pg/ml vs (156.25±47.83) pg/ml,(300.74±300.91) U/L vs (177.00±32.14) U/L,both P ＜ 0.05].The high expression level of serum sIL-2R was correlated with low CD4/CD8 ratio (r =0.4635,P ＜ 0.05).The high expression levels of serum sIL-2R was correlated with the high expression levels of serum VEGF,LDH (r =0.447,P ＜ 0.05; r =0.448,P ＜ 0.05).Conclusion High expression levels of serum sIL-2R in DLBCL are closely associated to low cellular immune function,tumor burden in vivo,disease progression and invasion.

Objective:To detect the influence of Ipas, and construct better Shigella vaccines.Methods: Guniea pigs were immunized with Ipa + and Ipa - bivalent Shigella vaccines strains by eyes mucosal immunization, and challenged with willed strains. The specific antibodies in tears were measured by BA ELISA assays after immunization and challenge. Results: The levels of specific local specific antibodies of immunized groups increased significantly compared to the control group and Ipa + group compared to Ipa - group after immunization.Conclusion: The expression of invasive plasmid antigens(Ipa) can enhance the levels of specific local antibodies. The two Shigella vaccines have good immunogenicity.

Objective To detect serum levels of thyroid hormones in patients with thyroid nodules (TN), and investi-gate their relationship with the nature of TN. Methods A total of 245 patients with TN were recruited in the study. Accord-ing to levels of thyroid antibodies and postoperative pathological results, all patients were divided into nodular goiter (NG) group, thyroid adenoma (TA) group and thyroid cancer (TC) group. TC group was further classified as the TC with increased level of thyroid antibodies (TC-AB+group) and the TC with normal level of thyroid antibodies (TC-AB-group). The serum levels of free T3 (FT3), free T4 (FT4) and thyroid stimulating hormone (TSH) were detected for all patients before operation, and differences of thyroid hormones were analyzed between different groups. Results The serum level of TSH was signifi-cantly higher in TC group than that of NG group and TA group (P<0.05). The serum level of FT3 was significantly lower in TC-AB+group than that of NG group and TC-AB-group. The serum level of FT4 was significantly lower in TC-AB+group than that of NG group, and the serum TSH level was significantly higher than that of other groups (P<0.05). Conclusion The increased serum levels of TSH were found in some patients with TC, which may partly attribute to their coexistence with autoimmune thyroiditis and subsequent hypothyroidism. The increased serum TSH level may not be the inherent characteris-tics of TC.

Objective:To explore the efficacy of etanercept combined leflunomide to treat ankylosing spondylitis (AS) and its safety.Methods:90 cases with AS patients admitted in our hospital from June 2016 to January 2015 were selected.The patients were divided into observation group and control group by random number table method,45 cases in each group.Observation group was treated with etanercept combined with leflunomide,the control group were treated by leflunomide only.Morning stiffness time,AS activity index (BASDAI),AS measurement index (BASMI) were recorded before and after treatment in two groups,the total effective rate and adverse reaction were compared between the two groups.Results:After treatment,the BASDAI and morning stiffness time,BASMI of two groups of patients compared with before treatment were decreased,and the indexes above of the observation group were significantly lower than the control group,the difference was statistically significant (P＜0.05);The effective rate of the observation group was significantly higher than that of the control group,the difference was statistically significant (P＜0.05);During the course of treatment,the main adverse reactions occurred in patients with liver function damage,diarrhea and allergic skin rash,but there was no significant difference in the incidence of adverse reactions between the two groups (P＞0.05).Conclusion:Etanercept combined with leflunomide can obtain ideal effect,and low incidence rate of adverse reaction,it is worth popularizing in clinical use.

The anti-tumor activity of curcumin against androgen-independent prostate cancer cells in vitro and the possible mechanism were investigated. After curcumin treatment, the effect of curcumin on the proliferation of prostate cancer PC-3 cells was assessed by CFSE staining. Flow cytometery (FCM) was performed to analyze the cell cycle and the induction of apoptosis of tumor cells. A luciferase reporter gene assay was used to determine the effects of curcumin on the activities of intracellular NF-κB and AP-1 signaling pathways. The results showed curcumin could effectively inhibit the proliferation of PC-3 cells in vitro (P<0.05). Cells were arrested at G(2)/M phase. After curcumin treatment, the percentage of apoptotic cells was significantly higher than in control group (P<0.05). The results of the luciferase assay revealed that curcumin selectively inhibited the activities of the NF-κB and AP-1 signaling pathways in PC-3 cells significantly. It was suggested that curcumin could exert anti-tumor activity against androgen-independent prostate cancer cells in vitro by inhibiting cellular proliferation and inducing apoptosis, which was probably contributed to the inhibition of transcription factors NF-κB and AP-1.

Objective To explore the application of osteopontin (OPN) and Stathmin- 1 expression in the evaluation of prostate cancer recurrence and survival prognosis. Methods One hundred patients with prostate cancer were selected from June 2014 to June 2016. The expressions of OPN and Stathmin-1 in prostate cancer tissue were detected by immunohistochemical staining SP method, and its correlation with clinicopathological features was analyzed. Results The OPN positive expression in prostate cancer tissue was in 76 cases (76.00%, 76/100), the Stathmin-1 positive expression in prostate cancer tissue was in 79 cases (79.00%, 79/100), and both the OPN and Stathmin-1 positive expression in prostate cancer tissue was in 60 cases (60.00% , 60/100). Spearman correlation analysis result showed that the expression of OPN in prostate cancer tissue had positive correlation with Stathmin-1 (r = 0.491, P＜0.01). The positive expressions of OPN and Stathmin-1 in prostate cancer tissue were relative with Gleason score, T staging and bone metastasis (P ＜ 0.05), but were not relative with recurrence (P＞0.05). The survival time in OPN positive expression, Stathmin-1 positive expression and both OPN/Stathmin-1 positive expression was (18.45 ± 2.03), (17.95 ± 2.01) and (15.24 ± 1.72) months;the survival time in OPN negative expression, Stathmin-1 negative expression and OPN/ Stathmin-1 single positive or both negative was (24.67 ± 2.62), (23.79 ± 2.58) and (26.68 ± 2.72) months, and there was statistical difference (P＜0.05). Conclusions The OPN and Stathmin-1 expressions in prostate cancer tissue are high, and show relations with Gleason score, bone metastases and T staging, and no correlation with recurrence. But OPN and Stathmin-1 can provide reference for survival in patients with prostate cancer prognosis assessment.

Atrial fibrillation (AF) is the most common type of arrhythmia, and its prevalence increases with age. Studies have shown that AF is associated with an increased risk of dementia. There is increasing evidence of potential treatment strategies to prevent dementia in patients with AF. This article reviews the preventive effects of anticoagulant therapy and catheter ablation on dementia in patients with AF.