基于细菌体系生产双链RNA的条件优化

化学杀虫剂是农业害虫防治的主要手段,然而农业害虫已对化学杀虫剂产生了抗药性。RNA农药的应用将是减少使用化学杀虫剂的一种途径。RNA农药具有专一、高效、易降解和对环境友好等优点而受到了关注,但在靶标分子、靶标分子的双链RNA（dsRNA）生产工艺和应用制剂等方面仍需进一步研究。本研究以褐飞虱Nilaparvata lugens蛋白激酶B基因的dsRNA（dsNlAKT）为例,对利用细菌体系生产dsRNA的方法进行了探究。将NlAKT构建进L4440载体后,将其转化到缺乏核酸酶（RNase Ⅲ）的大肠杆菌Escherichia coli HT115（DE3）中,进行了dsRNA生产条件的测试。结果表明：（1）当异丙基-β-D-硫代半乳糖苷（IPTG）工作浓度为0.1 mM或0.5 mM时dsRNA的产量没有明显变化,而当其工作浓度增加至1 mM时dsRNA产量明显减少;（2）在IPTG诱导时间为2~8 h范围内,添加IPTG后诱导6 h获得的dsRNA产量最多;（3）在实验室常规提取RNA方法中,增加低剂量溶菌酶预处理这一步骤可增加提取产物中dsRNA的含量。试验结果证明了采用工作浓度为0.1 mM的IPTG诱导6 h的生产条件,并在提取过程中增加溶菌酶的预处理步骤有助于获得较高的dsRNA含量。研究结果为RNA农药的生产条件提供了实验依据。     

水稻离体体细胞胚与合子胚的某些生化特性的比较

水稻离体培养的体细胞胚（ＳＥ）与整体植株合子胚（ＺＥ）的蛋白质组分相似,约有１７条多队的分子量相同,其中６７～９１ｋＤ范围的多肽在非胚性愈伤组织（ＮＥ）中均很弱,３９、１７、６０ｋＤ多肽在ＮＥ中未发现。ＳＥ的游离氨基酸组成与ＺＥ也相似,占优势的氨基酸为Ａｓｐ,Ｇｌｕ,Ａｌａ,Ｌｙｓ,在分化后期Ａｒｇ含量也有提高,而在ＮＥ中这些内源氨基酸的含量均较低。此外,在两种类型的胚中都存在凝集素类的物质,而在无胚状体形成的ＮＥ中则未发现。     

水稻胚乳甲壳素结合蛋白的cDNA克隆

水稻胚乳甲壳素结合蛋白的ｃＤＮＡ克隆杨日耀,王彤宇,唐锡华（中国科学院上海植物生理研究所,上海２０００３２）关键词水稻胚乳甲壳素结合蛋白,ｃＤＮＡ克隆,插入片段,抗体筛选水稻胚乳中存在一种甲壳素结合蛋白,它是一种分子量为２０ｋＤ的单亚基蛋白质,以等电...     

Extranodal natural killer/T-cell lymphoma involving the gastrointestinal tract: analysis of clinical features and outcomes from the Asia Lymphoma study group

Background

The gastrointestinal (GI) tract is one of the most common extranasal sites in extranodal NK/T-cell lymphoma (ENKTL). However, data regarding ENKTL involving the GI tract are relatively scarce. Thus, we performed a multicenter, multinational retrospective study to analyze clinical features and treatment outcomes of ENKTL involving the GI tract.

Patients and methods

Patients with ENKTL involving the GI tract diagnosed in twelve participating centers between 1991 and 2012 were retrospectively analyzed from five Asian countries.

Results

The analysis of 81 patients with ENKTL involving the GI tract revealed that more than 60% of patients presented as advanced disease with B symptoms. 55 patients (68%) had GI manifestations including abdominal pain (n = 26, 32%), GI tract bleeding (n = 17, 21%) and bowel perforation (n = 12, 15%). The most common GI site was the small intestine, including the jejunum and ileum (n = 57, 70.3%). There were 34 patients (42%) who received systemic chemotherapy while 33 patients (41%) underwent surgery plus chemotherapy. However, 35 patients (43%) died due to disease progression, and treatment-related mortality including sepsis occurred in 17 patients (21%). Thus, the median overall survival was 7.8 months (95% Confidence interval: 3.9 – 11.7 months). Patients who could undergo surgery plus chemotherapy showed a trend of better survival than those treated with chemotherapy alone.

Conclusion

Overall, the data indicated that ENKTL involving the GI tract has a dismal prognosis despite active treatment including chemotherapy and surgery. Thus, more effective treatment strategies are required for this disease entity.

     

Blood Lymphocyte-to-Monocyte Ratio Identifies High-Risk Patients in Diffuse Large B-Cell Lymphoma Treated with R-CHOP

Background

Recent research has shown a correlation between immune microenvironment and lymphoma biology. This study aims to investigate the prognostic significance of the immunologically relevant lymphocyte-to-monocyte ratio (LMR), in diffuse large B-cell lymphoma (DLBCL) in the rituximab era.

Methodology/Principal Findings

We analyzed retrospective data from 438 newly diagnosed DLBCL patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy. We randomly selected 200 patients (training set) to generate a cutoff value for LMR by receiver operating characteristic (ROC) curve analysis. LMR was then analyzed in a testing set (n = 238) and in all patients (n = 438) for validation. The LMR cutoff value for survival analysis determined by ROC curve in the training set was 2.6. Patients with low LMR tended to have more adverse clinical characteristics. Low LMR at diagnosis was associated with worse survival in DLBCL, and could also identify high-risk patients in the low-risk IPI category. Multivariate analysis identified LMR as an independent prognostic factor of survival in the testing set and in all patients.

Conclusions/Significance

Baseline LMR, a surrogate biomarker of the immune microenvironment, is an effective prognostic factor in DLBCL patients treated with R-CHOP therapy. Future prospective studies are required to confirm our findings.     

Prediction of acute cellular renal allograft rejection by urinary metabolomics using MALDI-FTMS

The present study investigated small molecule analysis of urinary samples as a noninvasive method to detect acute cellular renal allograft rejection. Matrix-assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS) was used to analyze 15 urinary samples from transplant patients with different grades of biopsy showing improved clinical acute cellular rejection (ACR) and 24 urinary samples from 8 transplant patients without evidence of rejection. Seven small molecules demonstrated highly successful diagnostic performance (m/z): 278.1 (t = 3.398, p = 0.004), 293.0 (t = 2.169, p = 0.048), 294.1 (t = 2.154, p = 0.05), 382.2 (t = 2.961, p = 0.010), 383.3 (t = 2.270, p = 0.040), 402.2 (t = 2.994, p = 0.010), 424.0 (t = 2.644, p = 0.019). Kidney transplant patients with ACR could be distinguished from those without ACR using four individual small molecules with a specificity of 100%. In conclusion, the combination of MALDI-FTMS technology with a clear definition of patient groups can detect urine small molecule associated with ACR.     

Identifying the Risk of SARS-CoV-2 Infection and Environmental Monitoring in Airborne Infectious Isolation Rooms (AIIRs)

Virologica Sinica - Healthcare workers (HCWs) are at high risk of occupational exposure to the new pandemic human coronavirus, SARS-CoV-2, and are a source of nosocomial transmission in airborne...     

Expression of BAFF and BAFF-R in Follicular Lymphoma: Correlation with Clinicopathologic Characteristics and Survival Outcomes

Background

B-cell activation factor (BAFF) and BAFF-receptor (BAFF-R) play crucial roles in the viability and proliferation of malignant lymphoma cells. Limited information exists regarding expression profiles and the prognostic role of BAFF and BAFF-R in follicular lymphoma (FL). We sought to determine the expression profiles of BAFF and BAFF-R in FL and to evaluate the correlation of BAFF and BAFF-R expression with clinicopathologic characteristics and outcome of FL. Correlation between expression levels of BAFF detected by immunohistochemical (IHC) and serum levels of BAFF was also evaluated.

Methods

Paraffin-embedded specimens from 115 patients were immunohistochemically examined for BAFF and BAFF-R expression. Expression levels were dichotomized into low versus high categories based on immunostaining intensity. The correlation of BAFF and BAFF-R expression with clinicopathologic characteristics and patient outcome was assessed. Serum levels of BAFF in 35 of the 115 patients with IHC data were measured by Enzyme-linked Immunosorbent assay (ELISA).

Results

BAFF and BAFF-R were expressed in 88.7% (102/115) and 87.8% (101/115) of the cases, respectively. BAFF expression was significantly correlated with only one clinicopathologic feature: Ann Arbor stage. No significant correlation was found between expression levels of BAFF detected by IHC and serum levels of BAFF detected by ELISA. High expression of BAFF-R, but not BAFF, was significantly correlated with inferior progression-free survival (PFS; P = 0.013) and overall survival (OS; P = 0.03). High expression of BAFF-R, bulky disease, and elevated lactate dehydrogenase were correlated with inferior PFS and OS in multivariate analysis. A prognostic scoring system incorporating these 3 risk factors identified 3 distinct prognostic groups with 5-year PFS of 59.4%, 41.9%, and 10.7% and OS of 91.3%, 79.7%, and 45.8%, respectively.

Conclusions

Most patients with FL variably express BAFF and BAFF-R. High expression of BAFF-R, but not BAFF, may be an independent risk factor for PFS and OS in FL.