Clinical Value of ELISA-MPT64 for the Diagnosis of Tuberculous Pleurisy

Tuberculous pleurisy is one of the common extrapulmonary tuberculosis diseases. However, the diagnosis of tuberculous pleurisy still lacks a useful and effective tool, mainly due to paucity of Mycobacterium tuberculosis organisms in pleural effusion. Previous studies have confirmed that the MPT64 protein is highly specific and is secreted only by M. tuberculosis (MTB) complex. Therefore, in this study, we developed ELISA based on recombinantly expressed MPT64 in combination with rabbit polyclonal antibodies. The ELISA-MPT64 method was validated using MTB strains and tested against clinical samples. Nested PCR, Löwenstein–Jensen (L–J) culture and smear microscopy were employed as the comparative tools for assessing the performance of the assay. Our results demonstrate that the newly established ELISA-MPT64 technique is a rapid and useful tool for the diagnosis of tuberculous pleurisy.     

蛋白质功能研究方法及技术

随着后基因时代的到来,蛋白质功能研究已经成为蛋白质组学研究的核心内容,是生物科学极具挑战的领域之一.近年来虽已有大量文章涉及某些蛋白质功能方面的研究,但对蛋白质功能研究方法方面进行系统综述的文章非常少,因此,从差异蛋白的筛选鉴定、蛋白质相互作用、蛋白质亚细胞定位、蛋白质表达改变的分子遗传学手段(如RNAi)、生物信息学等方面对目前蛋白质功能研究方法和技术及其最新研究进展进行综述,研究者可根据不同的蛋白和实验需要选择适宜的方法.     

Sex influences the association between haemostasis and the extent of lung lesions in tuberculosis

Background

Worldwide tuberculosis (TB) reports show a male bias in morbidity; however, the differences in pathogenesis between men and women with TB, as well as the mechanisms associated with such differences, are poorly investigated. We hypothesized that comparison of the degree of lung injury and clinical indices of well-matched men and women with newly diagnosed TB, and statistical analysis of the correlation between these indices and the extent of lung lesions, can provide insights into the mechanism of gender bias in TB.

Methods

We evaluated the acid-fast bacilli grading of sputum samples and compiled computed tomography (CT) data of the age-matched, newly diagnosed male and female TB patients without history of smoking or comorbidities. Inflammatory biomarker levels and routine haematological and coagulation-associated parameters were compared. Binary logistic regression analysis was used to define the association between the indices and lung lesions, and the influence of sex adjustment.

Results

Women with TB have a longer delay in seeking healthcare than men after onset of the TB-associated symptoms. Men with TB have significantly more severe lung lesions (cavities and healing-associated features) and higher bacterial counts compared to women with TB. Scoring of the CT images before and after anti-TB treatment showed a faster response to therapy in women than in men. Coagulation- and platelet-associated indices were in models from multivariate regression analysis with groups of males or females with TB or in combination. In univariate regression analysis, lower lymphocyte counts were associated with both cavity and more bacterial counts, independent of sex, age and BMI. The association of international normalized ratios (INR), prothrombin times (PTs), mean platelet volumes (MPVs) and fibrinogen (FIB) level with lung lesions was mostly influenced by sex adjustment.

Conclusions

Sex influences the association between haemostasis and extent of TB lung lesions, which may be one mechanism involved in sex bias in TB pathogenesis.

     

芽孢杆菌M50产生β—甘露聚糖酶的条件研究

从土壤中分离到９株产生β－甘露聚糖酶的芽孢杆菌（Ｂａｃｉｌｌｕｓ ｓｐ．）。Ｂａｃｉｌｌｕｓ ｓｐ．Ｍ５０２５０ｍＬ三角瓶摇瓶培养试验,以４％的魔芋粉为碳源,１．０％（ＮＨ４）２ＳＯ４为氮源,０．３５％Ｎａ２ＣＯ３,３０～３４℃培养６０ｈ产酶达到高峰。酶活力为１８０～２２０ｕ／ｍＬ。１００Ｌ罐发酵,在３０～３２℃,１：０．７５ｖｖｍ通气量,２００ｒ／ｍｉｎ条件下,发酵液酶活力高达３３０ｕ／ｍＬ。     

Human Mesenchymal Stem Cells Signals Regulate Neural Stem Cell Fate

Neural stem cells (NSCs) differentiate into neurons, astrocytes and oligodendrocytes depending on their location within the central nervous system (CNS). The cellular and molecular cues mediating end-stage cell fate choices are not completely understood. The retention of multipotent NSCs in the adult CNS raises the possibility that selective recruitment of their progeny to specific lineages may facilitate repair in a spectrum of neuropathological conditions. Previous studies suggest that adult human bone marrow derived mesenchymal stem cells (hMSCs) improve functional outcome after a wide range of CNS insults, probably through their trophic influence. In the context of such trophic activity, here we demonstrate that hMSCs in culture provide humoral signals that selectively promote the genesis of neurons and oligodendrocytes from NSCs. Cell–cell contacts were less effective and the proportion of hMSCs that could be induced to express neural characteristics was very small. We propose that the selective promotion of neuronal and oligodendroglial fates in neural stem cell progeny is responsible for the ability of MSCs to enhance recovery after a wide range of CNS injuries. Special issue dedicated to Anthony Campagnoni.     

结核分枝杆菌Rv1385的抗原表位预测分析

结核分枝杆菌生长缓慢,难以获得足量的天然蛋白抗原。而利用基因工程技术制备重组蛋白抗原,存在着表达量低、不易纯化,以及特异性较低等不利因素。随着生物信息技术的发展,研究者可根据生物信息学软件预测,选择合成优势抗原肽段,而不需克隆整个蛋白,具有简便、经济、特异性高等特点。因此,本研究应用生物信息学方法,预测结核分枝杆菌Rv1385蛋白的抗原表位并分析其优势表位,对了解Rv1385蛋白的免疫学特性及其与结核分枝杆菌致病的关系具有重要意义。首先,从NCBI数据库下载Rv1385的氨基酸序列,然后采用生物信息学软件PSIPRED Server预测蛋白质二级结构;BepiPred 1.0 Server和ABCpred预测该蛋白的B细胞抗原表位;BIMAS、SYFPEITHI及NetCTLpan 1.1 Server预测该蛋白的CTL表位;SYFPEITHI和NetMHCIIpan 3.2 Server预测该蛋白的Th细胞表位。最后综合分析预测结核分枝杆菌Rv1385的优势候选抗原表位。结果显示,Rv1385蛋白二级结构中,α螺旋占51.8%,β折叠占41.6%,无规卷曲占6.6%;共有4个B细胞抗原位点,位于109～124、152～169、178～192、198～209氨基酸区段;3个CTL表位,位于263～271、87～95、240～248氨基酸区段;5个Th表位,位于77～91、87～101、234～247、70～84、46～60氨基酸区段。生物信息学分析显示Rv1385含有潜在的B细胞和T细胞抗原表位,为该蛋白抗原表位的进一步研究及应用奠定了基础。     

1,3βD葡聚糖与抗白假丝酵母生殖管抗体对侵袭性假丝酵母菌病诊断价值评估

目的评估1,3-β-D-葡聚糖和白假丝酵母生殖管抗体试验对侵袭性假丝酵母菌病的早期诊断价值。方法于PubMed、Cochrane library、知网(CNKI)、WanFang(万方)、VIP(维普)和CBM(中国生物信息学)数据库对截止2019年4月中英文文献进行检索,并对文献质量进行评价。结果共纳入6个研究,合计359例患者,1,3-β-D-葡聚糖试验:敏感性为0.75(95%CI 0.67-0.82),特异性为0.75(95%CI 0.68-0.80),阳性似然比为3.18(95%CI 1.76-5.75),阴性似然比为0.34(95%CI 0.21-0.56),SROC曲线面积AUC=0.824 3;抗白假丝酵母生殖管抗体试验:敏感性为0.57(95%CI 0.48-0.65),特异性为0.78(95%CI 0.72-0.83),阳性似然比为3.07(95%CI 1.47-5.65),阴性似然比为0.59(95%CI 0.47-0.75),SROC曲线面积AUC=0.754 4;联合诊断:敏感性为0.93(95%CI 0.86-0.98),特异性为0.72(95%CI 0.64-0.80),阳性似然比为3.44(95%CI 1.63-7.29),阴性似然比为0.12(95%CI 0.06-0.25),SROC曲线面积AUC=0.928 3。结论 1,3-β-D-葡聚糖和抗白假丝酵母生殖管抗体单独检测对侵袭性假丝酵母菌病的诊断价值无明显差异,但二者联合检测时诊断价值比抗白假丝酵母生殖管抗体单独检测高。     

A multi-center study to evaluate the performance of phage amplified biologically assay for detecting TB in sputum in the pulmonary TB patients

Objective

To evaluate the performance of phage amplified biologically assay (PhaB) for detecting tuberculosis (TB) in sputum in the pulmonary tuberculosis (PTB) patients.

Methods

Shanghai Tuberculosis Key Laboratory of Shanghai Pulmonary Hospital participated in the project in collaboration with the laboratories of six hospitals and a total of 1660 eligible participants (1351 PTB patients and 309 non-TB patients) were included in the study. The sputum samples from the participants were detected by smear microscopy, PhaB, and Löwenstein-Jensen (L-J) culture method, respectively.

Results

The overall sensitivity of PhaB were higher than that of L-J culture and smear microscopy (p<0.05). The sensitivity of PhaB for detecting smear-negative specimens was obviously higher than that of L-J culture (p<0.05). Compared with L-J culture, the overall sensitivity, specificity, PPV, NPV, ACC and Kappa value of PhaB were 98.4 (95% Cl: 96.9–99.3), 71.6 (95% Cl: 68.4–74.6), 67.7, 98.7, 81.7% and 0.643, respectively. The detection median time of PhaB only needed 48 hours, which was significantly less than that (31 days) of L-J culture method.

Conclusion

PhaB method is a rapid and sensitive method for detecting TB in sputum in PTB patients; especially for the diagnosis of smear-negative PTB, PhaB method is obviously more sensitive than L-J culture method.     

Characteristics of Klebsiella pneumoniae harboring QnrB32, Aac(6')-Ib-cr, GyrA and CTX-M-22 genes

Quinolone resistance in members of the Enterobacteriaceae family is mostly due to mutations in the quinolone resistance-determining regions of topoisomerase genes. CTX-M-22 is a member of the CTX-M family which can reduce extended-spectrum β-lactamase (ESBL) production and modulate antibiotic resistance, resulting in low ceftazidime minimum inhibitory concentrations (MICs). There are four different genes in Klebsiella pneumoniae (KP4707) including qnrB32 (novel qnr allele gene, HQ704413), aac(6')-Ib-cr (novel aac(6')-Ib allele gene, HQ680690), gyrA (novel gyrA allele gene, HQ680691) and CTX-M-22 gene. Five point amino acid mutations Arn(N)27 → Leu(L), Val(V)129 → Ala(A), Iie(I)142 → Met(M), Gly(G)188 → Arg(R), Val(V)212 → Iie(I) were observed in the qnr32 gene when compared to qnrB1. Of all qnrB alleles, a novel variant of the qnrB32 gene, with qnrB31, had the highest amino acid homology. Three point amino acid mutations including Trp(W)105 → Arg(R), Asp(D)182 → Tyr(Y) and Val(V)201 → Asp(D) were observed in aac(6')-Ib-cr gene, when compared to GenBank number AF479774. New variants of qnr32, aac(6')-Ib-cr, gyrA and CTX-M-22 or other genotype determinants continuously appear in different genomic sites and also outside the Enterobacteriaceae family.     

Detection of Flaviviruses by Reverse Transcriptase-Polymerase Chain Reaction with the Universal Primer Set

Using a universal primer set designed to match the sequence of the NS1 gene of flaviviruses, the virus RNA of dengue (DEN), Japanese encephalitis (JEV), powassan and langat of Flaviviridae were successfully amplified by polymerase chain reaction (PCR) via cDNA; and with different internal primers, the serotypes of the dengue viruses were identified. Of the 78 clinically diagnosed dengue fever patients, 18 patients were positive for DEN 1, 48 patients for DEN 2 and 8 patients concurrently infected with DEN 4. Of the 52 patients admitted with Japanese encephalitis (JE), 45 were determined to be JEV infections. By nested PCR, we completed the identification of flaviviruses within 2 days. The results show that seven primers have a potential value for rapid clinical diagnosis of flavivirus infections.