RT-PCR检测16S rRNA基因片段对麻风菌活性的评价

目的:探讨麻风病患者皮损组织中麻风菌16S rRNA基因片段判断麻风菌活性的应用价值。方法:根据BI值和联合化疗(MDT)的疗期对27例麻风患者分组,以RT-PCR法检测皮损组织中麻风菌16S rRNA的特异性片段。结果:(1)无论BI高低,未经治疗的患者16S rRNA均为阳性。(2)MDT治疗、BI≥3～6者的11例患者中:有9例16SrRNA为阳性,MDT疗期小于和大于6个月的两组中均各有1例患者16S rRNA阴性。(3)MDT治疗、BI≤2的6例患者:有1例MDT小于6个月病人其16S rRNA阳性,其余5例患者16SrRNA均为阴性。结论:随MDT治疗的进行,麻风菌16S rRNA阳性患者比例减少;诊断时BI值越低的患者中,经治疗后皮损中麻风菌16S rRNA阴转的比例增大,提示麻风菌16S rRNA与患者皮损中麻风菌活性具有相关性。     

The role of ficolins and MASPs in hereditary angioedema due to C1-inhibitor deficiency

Background and ObjectiveHereditary angioedema due to C1-inhibitor deficiency (HAE-C1-INH) causes disturbances in the complement system. However, the influence of HAE-C1-INH on the lectin pathway of complement is unresolved. Thus, we studied the main initiator molecules, enzymes and regulators in the lectin pathway in patients with HAE-C1-INH.MethodsThe serum concentrations of ficolin-2, ficolin-3, MBL, MASP-2, MASP-3, and MAP-1 were measured during symptom-free periods in 91 patients with HAE-C1-INH, and in 100 healthy controls using sandwich ELISAs.ResultsCompared with controls, the levels of ficolin-2 (p < 0.0001) and MASP-2 (p = 0.0238) were reduced, while the levels of MBL and MASP-3 were elevated (p = 0.0028 and p < 0.0001, respectively) in HAE-C1-INH patients. Ficolin-3 and MAP-1 levels did not differ significantly between the two groups. Ficolin-2 correlated with MASP-3 in patients (r = 0.3443, p = 0.0008), while these parameters showed an opposite relationship in controls (r = −0.4625, p < 0.0001). In the patients, ficolin-3 correlated with MASP-2 (r = 0.3698, p = 0.001). Ficolin-2, -3, and MAP-1 correlated negatively with the annual requirement of plasma derived C1-INH concentrate (r = −0.2863, p = 0.0059; r = −0.2654, p = 0.0110 and r = −0.2501, p = 0.0168, respectively). Ficolin-3 showed a negative correlation with the annual number of attacks (r = −0.2478, p = 0.0179).ConclusionsWe found significant differences between patients and controls in the levels of some of the molecules belonging to the lectin complement pathway. Low concentrations of particularly ficolin-2 and -3 were inversely correlated with the severity of HAE-C1-INH, while this was not observed for MBL. This suggests a previously unrecognized involvement of the ficolin-dependent lectin complement pathway in the pathophysiology of HAE-C1-INH.     

Characterization of the tick-pathogen interface by quantitative proteomics

Ticks are vectors of pathogens that affect human and animal health worldwide. Ticks and the pathogens they transmit have co-evolved molecular interactions involving genetic traits of both the tick and the pathogen that mediate their development and survival. Proteomics and genomics studies of infected ticks are required to understand tick-pathogen interactions and identify potential vaccine antigens to control tick infestations and pathogen transmission. In this paper, the application of quantitative proteomics to characterize differential protein expression in ticks and cultured tick cells in response to pathogen infection is reviewed. Analyses using (a) two-dimensional differential in gel electrophoresis (DIGE) labeling and (b) protein one-step in gel digestion, peptide iTRAQ labeling, and isoelectric focusing fractionation, both followed by peptide and protein identifications by mass spectrometry resulted in the identification of host, pathogen, and tick proteins differentially expressed in response to infection. Although at its infancy, these results showed that quantitative proteomics is a powerful approach to characterize the tick-pathogen interface and demonstrated pathogen and tick-specific differences in protein expression in ticks and cultured tick cells in response to pathogen infection.     

Two novel fusion inhibitors of human respiratory syncytial virus

To search for novel drugs against human respiratory syncytial virus (RSV), we have screened a diversity collection of 16,671 compounds for anti-RSV activity in cultures of HEp-2 cells. Two of the hit compounds, i.e., the N-(2-hydroxyethyl)-4-methoxy-N-methyl-3-(6-methyl[1,2,4]triazolo[3,4-a]phthalazin-3-yl)benzenesulfonamide (designated as P13) and the 1,4-bis(3-methyl-4-pyridinyl)-1,4-diazepane (designated as C15), reduced the virus infectivity with IC₅₀ values of 0.11 and 0.13 μM respectively. The concentration of P13 and C15 that reduced the viability of HEp-2 cells by 50% was 310 and 75 μM respectively. Both P13 and C15 exhibited no direct virucidal activity or inhibitory effects on the virus attachment to cells. However, to inhibit formation of RSV-induced syncytial plaques P13 and C15 had to be present during the virus entry into the cells and the cell-to-cell transmission of the virus. The RSV multiplication in HEp-2 cells in the presence of P13 or C15 resulted in rapid selection of viral variants that were ∼1000 times less sensitive to these drugs than original virus. Sequencing of resistant viruses revealed presence of amino acid substitutions in the F protein of RSV, i.e., the D489G for C15-selected, and the T400I and N197T (some clones) for the P13-selected virus variants. In conclusion, we have identified two novel fusion inhibitors of RSV, and the detailed understanding of their mode of antiviral activity including selection for the drug resistant viral variants may help to develop selective and efficient anti-RSV drugs.     

肺吸虫成虫抗原组分分析

用 IE、SDS-PAGE 和 Western blot 对肺吸虫成虫抗原(PwA)成分进行分析.结果 IE 出现2条粗而明显的沉淀带。SDS-PAGE 显示29条蛋白带(分子量范围为90.0～6.0 kD),其中有10条主带,分子量分别为57、53、49.5、46、42、30、27、25、14和13 kD.经 Western blot 试验显示,肺吸虫病人血清(抗体)与 PwA 应答,可出现3条蛋白带,分子量分别为25、13和8 kD。     

TNF blockers and tuberculosis: an Indian concern

Reactivation of latent tuberculosis (TB) with TNF blockers is a cause of concern particularly in developing countries like India, which has a high burden of TB infection. Although etanercept and infliximab are available in India, published data on Indian experience are scant. Limited data indicate that risk of reactivation of TB is substantially increased. With the growing use of these agents in India inspired by encouraging results in various rheumatic conditions a rise in cases of TB is expected. At present, no guidelines exist in India with regard to treatment of latent TB. Indian rheumatologists must adopt a rational approach when treating rheumatic diseases with TNF blockers.     

Single pore translocation of folded,double-stranded,and tetra-stranded DNA through channel of bacteriophage phi29 DNA packaging motor

The elegant architecture of the channel of bacteriophage phi29 DNA packaging motor has inspired the development of biomimetics for biophysical and nanobiomedical applications. The reengineered channel inserted into a lipid membrane exhibits robust electrophysiological properties ideal for precise sensing and fingerprinting of dsDNA at the single-molecule level. Herein, we used single channel conduction assays to quantitatively evaluate the translocation dynamics of dsDNA as a function of the length and conformation of dsDNA. We extracted the speed of dsDNA translocation from the dwell time distribution and estimated the various forces involved in the translocation process. A ∼35-fold slower speed of translocation per base-pair was observed for long dsDNA, a significant contrast to the speed of dsDNA crossing synthetic pores. It was found that the channel could translocate both dsDNA with ∼32% of channel current blockage and with ∼64% for tetra-stranded DNA (two parallel dsDNA). The calculation of both cross-sectional areas of the dsDNA and tetra-stranded DNA suggested that the blockage was purely proportional to the physical space of the channel lumen and the size of the DNA substrate. Folded dsDNA configuration was clearly reflected in their characteristic current signatures. The finding of translocation of tetra-stranded DNA with 64% blockage is in consent with the recently elucidated mechanism of viral DNA packaging via a revolution mode that requires a channel larger than the dsDNA diameter of 2 nm to provide room for viral DNA revolving without rotation. The understanding of the dynamics of dsDNA translocation in the phi29 system will enable us to design more sophisticated single pore DNA translocation devices for future applications in nanotechnology and personal medicine.