The dysfunction of CD8+ T cells triggered by endometriotic stromal cells promotes the immune survival of endometriosis.

Endometriosis is defined as an oestrogen-dependent and inflammatory gynaecological disease of which the pathogenesis remains unclear. This study aimed to investigate the cellular heterogeneity and reveal the effect of CD8+ T cells on the progress of endometriosis. Three ovarian endometriosis patients were collected, and single-cell RNA sequencing (scRNA-seq) progressed and delineated the cellular landscape of endometriosis containing five cell clusters. The endometrial cells (EMCs) were the major component, of which the mesenchymal cells were preponderant and characterized with increased inflammation and oestrogen synthesis in endometriosis. The proportion of T cells, mainly CD8+ T cells rather than CD4+, was reduced in endometriotic lesions, and the cytokines and cytotoxicity of ectopic T cells were depressed. CD8+ T cells depressed the proliferation of ESCs through inhibiting CDK1/CCNB1 pathway to arrest the cell cycle and triggered inflammation through activating STAT1 pathway. Correspondingly, the coculture with ESCs resulted in the dysfunction of CD8+ T cells through upregulating STAT1/PDCD1 pathway and glycolysis-promoted metabolism reprogramming. The endometriotic lesions were larger in nude mouse models with T-cell deficiency than the normal mouse models. The inhibition of T cells via CD90.2 or CD8A antibody increased the endometriotic lesions in mouse models, and the supplement of T cells to nude mouse models diminished the lesion sizes. In conclusion, this study revealed the global cellular variation of endometriosis among which the cellular count and physiology of EMCs and T cells were significantly changed. The depressed cytotoxicity and aberrant metabolism of CD8+ T cells were induced by ESCs with the activation of STAT1/PDCD1 pathway resulting in immune survival to promote endometriosis.

Development and evaluation of neutralizing antibodies for cross-protection against West Nile virus and Japanese encephalitis virus.

Background: West Nile virus is a severe zoonotic pathogen that can cause severe central nervous system symptoms in humans and horses, and is fatal for birds, chickens and other poultry. With no specific drugs or vaccines available, antibody-based therapy is a promising treatment. This study aims to develop neutralizing antibodies against West Nile virus and assess their cross-protective potential against Japanese encephalitis virus. Methods: Monoclonal antibodies against WNV and JEV were isolated by hybridoma technology. The therapeutic efficacy of these antibodies was evaluated using a mouse model, and a humanized version of the monoclonal antibody was generated for potential human application. Results: In this study, we generated eight monoclonal antibodies that exhibit neutralizing activity against WNV. Their therapeutic effects against WNV were validated both in vivo and in vitro. Among these antibodies, C9-G11-F3 also exhibited cross-protective activity against JEV. We also humanized the antibody to ensure that it could be used for WNV infection treatment in humans. Conclusion: This study highlights the importance of neutralizing antibodies as a promising approach for protection against West Nile virus infection and suggests their potential utility in the development of therapeutic interventions.

Disulfiram enhances cisplatin cytotoxicity by forming a novel platinum chelate Pt(DDTC)3.

Despite the use of targeted therapy in non-small cell lung cancer (NSCLC) patients, cisplatin (DDP)-based chemotherapy is still the main option. However, DDP resistance is the major factor contributing to the failure of chemotherapy. In this study, we tried to screen DDP sensitizers from an FDA-approved drug library containing 1374 small-molecule drugs to overcome DDP resistance in NSCLC. As a result, disulfiram (DSF) was identified as a DDP sensitizer: DSF and DDP had synergistic anti-NSCLC effects, which are mainly reflected in inhibiting tumor cell proliferation, plate colony formation and 3D spheroidogenesis and inducing apoptosis in vitro, as well as the growth of NSCLC xenografts in mice. Although DSF has recently been reported to promote the antitumor effect of DDP by inhibiting ALDH activity or modulating some important factors or pathways, unexpectedly, we found that DSF reacted with DDP to form a new platinum chelate, Pt(DDTC)3+, which might be one of the important mechanisms for their synergistic effect. Moreover, Pt(DDTC)3+ has a stronger anti-NSCLC effect than DDP, and its antitumor activity is broad-spectrum. These findings reveal a novel mechanism underlying the synergistic antitumor effect of DDP and DSF, and provide a drug candidate or a lead compound for the development of a new antitumor drug.

Comparison of Pharmacokinetics of Aprepitant in Healthy Chinese and Caucasian Subjects.

PURPOSE: Aprepitant is used to prevent nausea and vomiting associated with moderately and highly emetogenic chemotherapy. In this open-label, 2-period study, the safety, tolerability, and pharmacokinetics (PK) of aprepitant (EMEND®) were evaluated in healthy Chinese and Caucasian subjects. PATIENTS AND METHODS: Twelve Chinese and 12 Caucasian subjects were to receive a 125 mg single-dose of aprepitant during period 1; subsequently, after 15 days washout, only Chinese subjects were to receive the 3-day regimen in period 2. In each period, serial blood samples were collected and analyzed by a validated liquid chromatographic and mass spectrometric method to characterize aprepitant PK across both groups. RESULTS: In both Chinese and Caucasian subjects, there were no serious adverse events. AUC0-∞, Cmax, Tmax, and t1/2 were largely comparable between the two ethnicities. Comparing the result of period 1 in Chinese and Caucasian subjects, the geometric least-squares mean maximum plasma concentrations (Cmax) were 1482 ng/mL and 1435 ng/mL, and the area under the concentration-time curve (AUC0-∞) 34,035 hr·ng/mL and 34,188 hr·ng/mL. In period 2, the geometric mean AUC0-24 on Day 1 and Day 3 were 19,446 hr·ng/mL and 27,843 hr·ng/mL, and the geometric mean Cmax on Day 1 and Day 3 were 1423 ng/mL and 1757 ng/mL, respectively. CONCLUSION: Aprepitant is generally safe and well tolerated in healthy Chinese and Caucasian subjects. Aprepitant PK is comparable between Chinese and Caucasian subjects following single-dose administration. The PK following a clinical 3-day regimen on healthy Chinese subjects has been characterized.

Comparison of third-generation sequencing approaches to identify viral pathogens under public health emergency conditions.

The capability of high-throughput sequencing (HTS) for detection of known and unknown viruses timely makes it a powerful tool for public health emergency response. Third-generation sequencing (TGS) offers advantages in speed and length of detection over second-generation sequencing (SGS). Here, we presented the end-to-end workflows for both Oxford Nanopore MinION and Pacbio Sequel on a viral disease emergency event, along with Ion Torrent PGM as a reference. A specific pipeline for comparative analysis on viral genomes recovered by each platform was assembled, given the high errors of base-calling for TGS platforms. All the three platforms successfully identified and recovered at least 85% Norovirus GII genomes. Oxford Nanopore MinION spent the least sample-to-answer turnaround time with relatively low but enough accuracy for taxonomy classification. Pacbio Sequel recovered the most accurate viral genome, while spending the longest time. Overall, Nanopore metagenomics can rapidly characterize viruses, and Pacbio Sequel can accurately recover viruses. This study provides a framework for designing the appropriate experiments that are likely to lead to accurate and rapid virus emergency response.

Genome-wide RNAi Screening Identifies RFC4 as a Factor That Mediates Radioresistance in Colorectal Cancer by Facilitating Nonhomologous End Joining Repair.

PURPOSE: Neoadjuvant chemoradiotherapy (neoCRT) is a standard treatment for locally advanced rectal cancer (LARC); however, resistance to chemoradiotherapy is one of the main obstacles to improving treatment outcomes. The goal of this study was to identify factors involved in the radioresistance of colorectal cancer and to clarify the underlying mechanisms. EXPERIMENTAL DESIGN: A genome-wide RNAi screen was used to search for candidate radioresistance genes. After RFC4 knockdown or overexpression, colorectal cancer cells exposed to X-rays both in vitro and in a mouse model were assayed for DNA damage, cytotoxicity, and apoptosis. Moreover, the regulatory effects and mechanisms of RFC4 in DNA repair were investigated in vitro. Finally, the relationships between RFC4 expression and clinical parameters and outcomes were investigated in 145 patients with LARC receiving neoCRT. RESULTS: RFC4, NCAPH, SYNE3, LDLRAD2, NHP2, and FICD were identified as potential candidate radioresistance genes. RFC4 protected colorectal cancer cells from X-ray-induced DNA damage and apoptosis in vitro and in vivo. Mechanistically, RFC4 promoted nonhomologous end joining (NHEJ)-mediated DNA repair by interacting with Ku70/Ku80 but did not affect homologous recombination-mediated repair. Higher RFC4 expression in cancer tissue was associated with weaker tumor regression and poorer prognosis in patients with LARC treated with neoCRT, which likely resulted from the effect of RFC4 on radioresistance, not chemoresistance. CONCLUSIONS: RFC4 was identified as a radioresistance factor that promotes NHEJ-mediated DNA repair in colorectal cancer cells. In addition, the expression level of RFC4 predicted radiotherapy responsiveness and the outcome of neoadjuvant radiotherapy in patients with LARC.

Decreased macrophage inflammatory protein (MIP)-1α and MIP-1ß increase the risk of developing nasopharyngeal carcinoma.

BACKGROUND: The association of circulating inflammation markers with nasopharyngeal carcinoma (NPC) is still largely unclear. This study aimed to comprehensively explore the relationship between circulating cytokine levels and the subsequent risk of NPC with a two-stage epidemiologic study in southern China. METHODS: The serum levels of 33 inflammatory cytokines were first measured in a hospital-based case-control study (150 NPC patients and 150 controls) using multiplex assay platforms. Marker levels were categorized into two or more groups based on the proportion of sample measurements that was above the lower limit of detection. Odds ratios (ORs) and 95% confidence intervals (CIs) relating the serum marker concentration to the risk of NPC were computed by multivariable logistic regression models. The associations were validated in 60 patients with NPC and 120 controls in a subsequent nested case-control study within a NPC screening trial. Potential interactions between serum cytokines and Epstein-Barr virus (EBV) relating to the risk of NPC were assessed using a likelihood ratio test. RESULTS: The levels of serum macrophage inflammatory protein (MIP)-1α and MIP-1ß in the highest categories were associated with a decreased risk of NPC in both the case-control study (MIP-1α: OR = 0.49, 95% CI = 0.26-0.95; MIP-1ß: OR = 0.47, 95% CI = 0.22-1.00) and the nested case-control study (MIP-1α: OR = 0.13, 95% CI = 0.03-0.62; MIP-1ß: OR = 0.20, 95% CI = 0.04-0.94), compared with those in the lowest categories. Furthermore, individuals with lower levels of these two cytokine markers who were EBV seropositive presented with a largely higher risk of NPC compared with patients with higher levels who were EBV seronegative in both the case-control study (MIP-1α: OR = 16.28, 95% CI = 7.11-37.23; MIP-1ß: OR = 12.86, 95% CI = 5.9-28.05) and the nested case-control study (MIP-1α: OR = 86.12, 95% CI = 10.58-701.03; MIP-1ß: OR = 115.44, 95% CI = 13.92-957.73). CONCLUSIONS: Decreased preclinical MIP-1α and MIP-1ß levels might be associated with a subsequently increased risk of NPC. More mechanistic studies are required to fully understand this finding.

VSITA, an Improved Approach of Target Amplification in the Identification of Viral Pathogens.

OBJECTIVE: Unbiased next generation sequencing (NGS) is susceptible to interference from host or environmental sequences. Consequently, background depletion and virome enrichment techniques are usually needed for clinical samples where viral load is much lower than background sequences. METHODS: A viral Sequence Independent Targeted Amplification (VSITA) approach using a set of non-ribosomal and virus-enriched octamers (V8) was developed and compared with traditionally used random hexamers (N6). Forty-five archived clinical samples of different types were used in parallel to compare the V8 and N6 enrichment performance of viral sequences and removal performance of ribosomal sequences in the step of reverse transcription followed by quantitative PCR (qPCR). Ten sera samples from patients with fever of unknown origin and 10 feces samples from patients with diarrhea of unknown origin were used in comparison of V8 and N6 enrichment performance following NGS analysis. RESULTS: A minimum 30 hexamers matching to viral reference sequences (sense and antisense) were selected from a dataset of random 4,096 (46) hexamers (N6). Two random nucleotides were added to the 5' end of the selected hexamers, and 480 (30 × 42) octamers (V8) were obtained. In general, VSITA approach showed higher enrichment of virus-targeted cDNA and enhanced ability to remove unwanted ribosomal sequences in the majorities of 45 predefined clinical samples. Moreover, VSITA combined with NGS enabled to detect not only more viruses but also achieve more viral reads hit and higher viral genome coverage in 20 clinical samples with diarrhea or fever of unknown origin. CONCLUSION: The VSITA approach designed in this study is demonstrated to possess higher sensitivity and broader genome coverage than traditionally used random hexamers in the NGS-based identification of viral pathogens directly from clinical samples.

A novel and highly sensitive real-time nested RT-PCR assay in a single closed tube for detection of enterovirus.

The sensitivity of qRT-PCR assay is not adequate for the detection of the samples with lower viral load, particularly in the cerebrospinal fluid (CSF) of patients. Here, we present the development of a highly sensitive real-time nested RT-PCR (RTN RT-PCR) assay in a single closed tube for detection of human enterovirus (HEV). The clinical performance of both RTN RT-PCR and qRT-PCR was also tested and compared using 140 CSF and fecal specimens. The sensitivities of RTN RT-PCR assay for EV71, Coxsackievirus A (CVA)16, CVA6 and CVA10 achieved 10-8 dilution with a corresponding Ct value of 38.20, 36.45, 36.75, and 36.45, respectively, which is equal to traditional two-step nested RT-PCR assay and approximately 2-10-fold lower than that of qRT-PCR assay. The specificity of RTN RT-PCR assay was extensively analyzed insilico and subsequently verified using the reference isolates and clinical samples. Sixteen qRT-PCR-negative samples were detected by RTN RT-PCR and a variety of enterovirus serotypes was identified by sequencing of inner PCR products. We conclude RTN RT-PCR is more sensitive than qRT-PCR for the detection of HEV in clinical samples.

Multiple pulmonary metastases with halo-sign from malignant mixed Müllerian tumors.

The lungs are one of the most common organs to which cancer metastasizes, but are a location not common for uterine sarcoma. A malignant mixed Müllerian tumor (MMMT) of the uterus is an extremely rare and aggressive sarcoma, characterized by a mixture of epithelial and mesenchymal components. There are few reports regarding the pulmonary metastasis from MMMTs. The present study presents the case of a 58-year-old woman with hemoptysis and post-menopausal vaginal bleeding. The woman was initially diagnosed with invasive aspergillosis based on a chest computed tomography (CT) scan showing multiple pulmonary nodular opacities surrounded by a ground-glass attenuation halo (halo-sign). Diagnostic curettage and a percutaneous CT-guided lung biopsy were conducted for the pathological diagnosis. Finally, the diagnosis was confirmed as MMMT with lung metastasis based on the histopathological examination of cervical canals, uterus and lung specimens, which showed a mixture of carcinomatous and sarcomatous elements, and morphology exhibiting hyperchromatic nuclei and necrosis. Immunohistochemical staining was positive for vimentin, focally positive for p16, and negative for napsin, cytokeratin 7 (CK7), CK20, carcinoembryonic antigen, carbohydrate antigen 125, homeobox protein CDX2 and villin in the lung specimens. This case highlights that pulmonary metastatic tumor from uterine sarcoma can present as halo-sign, which is commonly observed in pulmonary aspergillosis. Therefore, it needs to be considered in the differential diagnosis of such lesions, and pathological confirmation is required.

Evaluation of seven recombinant VCA-IgA ELISA kits for the diagnosis of nasopharyngeal carcinoma in China: a case-control trial.

OBJECTIVE: Seven recombinant viral capsid antigen-IgA (VCA-IgA) ELISA kits are widely used in China, but their diagnostic effects have not been evaluated. In this study, we evaluated whether the diagnostic effects of these kits are similar to those of the standard kit (EUROIMMUN, Lübeck, Germany). METHODS: A diagnostic case-control trial was conducted with 200 cases of nasopharyngeal carcinoma (NPC) and 200 controls from NPC-endemic areas in southern China. The areas under the curve (AUCs), the sensitivities and the specificities of testing kits were compared with those of the standard kit. The test-retest reliability of each kit was determined by intraclass correlation coefficient (ICC). Their diagnostic accuracy in combination with Epstein-Barr virus nuclear antigen 1-IgA (EBNA1-IgA) was also evaluated in logistic models. RESULTS: Three testing kits-BB, HA and KSB-showed diagnostic accuracy equal to that of the standard kit, with good performance in the AUCs (0.926-0.945), and no significant differences in sensitivity were found between early-stage and advanced-stage NPCs. ICCs exceeded 0.8. Three logistic regression models were built, and the AUCs of these models (0.961-0.977) were better than those of the individual VCA-IgA kits. All new models had diagnostic accuracy equal to that of the standard kit. New cut-off values of these three kits and their corresponding combinations for researchers to replicate and use in NPC early detection and screening in the future were provided. CONCLUSIONS: Three recombinant VCA-IgA kits-BB,HA and KSB-had diagnostic effects equal to those of the standard kit, and, in combination with EBNA1-IgA in logistic regression models, can be used in future screening for NPC.

Elemental compositions of lichens from Duolun County, Inner Mongolia, China: Origin, road effect and species difference.

To assess the response of lichen elemental compositions to road traffic and species difference in the context of high dust input and anthropogenic emissions, two foliose epiphytic lichens (Phaeophyscia hirtuosa, PHh; Candelaria fibrosa, CAf) were sampled near a road adjacent to Dolon Nor Town (Duolun County, Inner Mongolia, China). Twenty elements (Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Sr, Ti, V and Zn) in lichen and surface soil samples were analysed using inductively coupled plasma mass spectrometer (ICP-MS). The results demonstrate that lichen elemental compositions are highly influenced by both their natural environment and anthropogenic input. Windblown dust associated with sand dunes and degraded/desertified steppes represents the predominant source of lichen elements. Road traffic can enhance the lichen elemental burden by increasing the number of soil particles. Anthropogenic emissions from the town and road traffic have also led to the enrichment of Cd and Zn in lichens. PHh was higher than CAf in concentrations of 14 terrigenous metals. Both lichens are applicable to biomonitoring of atmospheric element deposition and, in most cases, yield comparable results.

Evaluation of the in vitro and in vivo metabolic pathway and cytochrome P450 inhibition/induction profile of Huperzine A.

Huperzine A (HupA), one of the reversible and selective acetylcholinesterase inhibitors derived from Chinese herb Huperzia Serrata, possesses affirmative action of ameliorating cognitive dysfunction of Alzheimer's disease. Up to now, the effects of HupA on human cytochrome P450s (CYPs) have not been fully elucidated. The purpose of the present study was to clarify the metabolic pathway of HupA in vitro and in vivo, and to evaluate the CYPs inhibition/induction profile of HupA in vitro. The catalytic activity of CYP enzymes (CYP1A2, 2A6, 2C9, 2C19, 2D6, 2E1 and 3A4) was measured by the quantification of specific enzyme substrates using validated liquid chromatography-tandem mass spectrometry (LC/MS/MS) methods. The in vivo metabolic pathway evaluation was performed in an open, single-dose pharmacokinetic study of HupA in fourteen elderly subjects, with urine collecting at certain intervals. In human liver microsomes, HupA (10 ng/mL) was not metabolized within 90 min, and it showed negligible inhibition against these CYP isoforms within 0.2-100 ng/mL. In human liver hepatocytes, the activities of CYP1A2 and CYP3A4 were not significantly altered when incubated at 2 or 20 ng/mL of HupA. After oral administration of 0.1 mg HupA, the total proportion of HupA excreted through urine was relatively high, accounting to 35± 9% at the limited time period of 48 h. These results suggest that HupA is substantially excreted by kidney unchanged rather than metabolized by human liver, and is unlikely to cause clinically relevant drug-drug interaction (DDI) when co-administrated with drugs that are metabolized by CYP isoenzyme system.

Subtype distribution and long-term titer fluctuation patterns of serum anti-Epstein-Barr virus antibodies in a non-nasopharyngeal carcinoma population from an endemic area in South China: a cohort study.

BACKGROUND: Serum immunoglobulin A antibodies against Epstein-Barr virus (EBV), viral capsid antigen (VCA-IgA) and early antigen (EA-IgA), are used to screen for nasopharyngeal carcinoma (NPC) in endemic areas. However, their routine use has been questioned because of a lack of specificity. This study aimed to determine the distributions of different subtypes of antibody and to illustrate how the natural variation patterns affect the specificity of screening in non-NPC participants. METHODS: The distribution of baseline VCA-IgA was analyzed between sexes and across 10-year age groups in 18,286 non-NPC participants using Chi square tests. Fluctuations in the VCA-IgA level were assessed in 1056 non-NPC participants with at least two retests in the first 5-year period (1987-1992) after the initial screening using the Kaplan-Meier method. RESULTS: The titers of VCA-IgA increased with age (P < 0.001). Using a previous serological definition of high NPC risk, nasopharyngeal endoscopy and/or nasopharyngeal biopsy would be recommended in 55.5% of the non-NPC participants with an initial VCA-IgA-positive status and in 20.6% with an initial negative status during the 5-year follow-up. However, seroconversions were common; 85.2% of the participants with a VCA-IgA-positive status at baseline converted to negative, and all VCA-IgA-negative participants changed to positive at least once during the 5-year follow-up. The EA-IgA status had a high seroconversion probability (100%) from positive to negative; however, it had a low probability (19.6%) from negative to positive. CONCLUSIONS: Age- and sex-specific cutoff titer values for serum anti-EBV antibodies as well as their specific titer fluctuation patterns should be considered when defining high NPC risk criteria for follow-up diagnostics and monitoring.

Secular trend analysis of lung cancer incidence in Sihui city, China between 1987 and 2011.

BACKGROUND: With industrial and econom ic development in recent decades in South China, cancer incidence may have changed due to the changing lifestyle and environment. However, the trends of lung cancer and the roles of smoking and other environmental risk factors in the development of lung cancer in rural areas of South China remain unclear. The purpose of this study was to explore the lung cancer incidence trends and the possible causes of these trends. METHODS: Joinpoint regression analysis and the age-period-cohort (APC) model were used to analyze the lung cancer incidence trends in Sihui, Guangdong province, China between 1987 and 2011, and explore the possible causes of these trends. RESULTS: A total of 2,397 lung cancer patients were involved in this study. A 3-fold increase in the incidence of lung cancer in both sexes was observed over the 25-year period. Joinpoint regression analysis showed that while the incidence continued to increase steadily in females during the entire period, a sharp acceleration was observed in males starting in 2005. The full APC model was selected to describe age, period, and birth cohort effects on lung cancer incidence trends in Sihui. The age cohorts in both sexes showed a continuously significant increase in the relative risk (RR) of lung cancer, with a peak in the eldest age group (80-84 years). The RR of lung cancer showed a fluctuating curve in both sexes. The birth cohorts identified an increased trend in both males and females; however, males had a plateau in the youngest cohorts who were born during 1955-1969. CONCLUSIONS: Increasing trends of the incidence of lung cancer in Sihui were dominated by the effects of age and birth cohorts. Social aging, smoking, and environmental changes may play important roles in such trends.

[Pathogenic spectrum of enteroviruses associated with hand, foot and mouth disease by a GeXP™-based multiplex reverse transcription-PCR assay in Jinan, China, 2009-2012].

We investigated the pathogenic spectrum of enteroviruses associated with hand, foot and mouth disease (HFMD) in Jinan, China. A total of 274 specimens with a clinical diagnosis of HFMD in Jinan from 2009 to June 2012 were used. A GenomeLab™ (GeXP)-based multiplex reverse transcription-polymerase chain reaction (RT-PCR) assay was employed to simultaneously detect 15 serotypes of human enteroviruses: human enterovirus (EV)71; coxsackievirus A (CVA)16, 4, 5, 6, 9, and 10; CVB1, 3 and 5; echovirus (Echo) 6, 7, 11, 13 and 19. Results showed that all samples were enterovirus-positive, with the most common serotypes being EV71 (25.18%) and CVA16 (16.06%), followed by CVA10 (14.23%), CVA6 (7.30%), CVB1 (1.09%), Echo6 (0.73%), CVA9 (0.36%), CVB3 (0.36%) and co-infections (5.11%). CVA10 and CVA6 had the third and fourth highest prevalence of pathogens for HFMD, respec- tively. The most prevalent season for CVA10 was from April to August, with a peak in April; for CVA6 it was from April to August, with a peak in June. This is the first report of the pathogenic spectrum of en- teroviruses associated with HFMD in Jinan using the GeXP-based multiplex RT-PCR assay. These data will provide the scientific evidence for the prevention and control of epidemics, as well as therapy for HFMD patients.

[Visual detection of HIV-1 by reverse transcription loop-mediated isothermal amplification with the hydroxynaphthol blue dye].

OBJECTIVE: A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for rapid visual detection of HIV-1. METHODS: RT-LAMP primers were designed according to conservative sequences of HIV-1 gag gene, and their sensitivity and specificity were evaluated by the established RT-LAMP protocol with the addition of the hydroxynaphthol blue (HNB) dye prior to amplification. The performance of RT-LAMP on clinical samples was compared with real-time reverse transcription PCR(qRT-PCR). RESULTS: The RT-LAMP assay showed a high specificity, and its detection limit was 1000 copies RNA per tube. The sensitivity and specificity of this method using 43 clinical samples were 94.6% and 100%, respectively,in comparison with those of qRT-PCR. CONCLUSION: RT-LAMP assay using hydroxynaphthol blue dye does not need expensive instruments, and offer an alternative for the rapid detection of HIV-1 with the potential to be applied in field diagnosis.

[The establishment of a new resequencing pathogen microarray-based assay for detecting unexplained respiratory tract infections].

Resequencing Pathogen Microarray (RPM) is a new pathogen detection and identification technology based on DNA microarray. In order to apply RPM in the detection of unexplained infection and as a result, to improve the emergency response capacity, a new RPM-based respiratory pathogens detection assay was developed to simultaneously detect 19 common respiratory viruses, 9 influenza A viruses (Flu A),11 human rhinoviruses(HRV), 28 enteroviruses and 18 rare respiratory viruses. The specificity of multiplex system was examined by confirmed positive specimens for 16 common respiratory virus. The sensi-tivity was evaluated by serial ten-fold dilutions of plasmids or in vitro-transcribed RNA. RPM could detect and differentiate 16 virus types/subtypes at 10 - 1 000 copies/reaction level. Nucleic acids of 8 throat swabs with unexplained respiratory tract infections were pooled and detected by the new assay. The RPM result was verified by common PCR followed by sequencing as well as PLEX-ID (Abbott). Except for a false-positive of PIV1, no difference among the three assays was found. These results indicate the assay based on the new RPM is a highly sensitive, high throughput test for the detection of respiratory virus infections, which is significant for the management of emergent and epidemic infectious disease.

Evaluation of a direct reverse transcription loop-mediated isothermal amplification method without RNA extraction for the detection of human enterovirus 71 subgenotype C4 in nasopharyngeal swab specimens.

Human enterovirus 71 (EV71) is the major causative agent of hand, foot, and mouth disease (HFMD) worldwide and has been associated with neurological complications which resulted in fatalities during recent outbreak in Asia pacific region. A direct reverse transcription loop-mediated isothermal amplification (direct RT-LAMP) assay using heat-treated samples without RNA extraction was developed and evaluated for the detection of EV71 subgenotype C4 in nasopharyngeal swab specimens. The analytical sensitivity and specificity of the direct RT-LAMP assay were examined. The detection limit of the direct RT-LAMP assays was 1.6 of a 50% tissue culture infective dose (TCID(50)) per reaction and no cross-reaction was observed with control viruses including Cosackievirus A (CVA) viruses (CVA2,4,5,7,9,10,14,16, and 24), Coxsackievirus B (CVB) viruses (CVB1,2,3,4, and 5) or ECHO viruses (ECHO3,6,11, and 19). The direct RT-LAMP assay was evaluated and compared to both RT-LAMP and quantitative real-time PCR (qRT-PCR) in detecting EV71 infection with 145 nasopharyngeal swab specimens. The clinical performance demonstrated the sensitivity and specificity of direct RT-LAMP was reported to be 90.3% and 100% respectively, compared to RT-LAMP, and 86.83% and 100% respectively, compared to qRT-PCR. These data demonstrated that the direct RT-LAMP assay can potentially be developed for the point of care screening of EV71 infection in China.

The development of a GeXP-based multiplex reverse transcription-PCR assay for simultaneous detection of sixteen human respiratory virus types/subtypes.

BACKGROUND: Existing standard non-molecular diagnostic methods such as viral culture and immunofluorescent (DFA) are time-consuming, labor intensive or limited sensitivity. Several multiplex molecular assays are costly. Therefore, there is a need for the development of a rapid and sensitive diagnosis of respiratory viral pathogens. METHODS: A GeXP-based multiplex RT-PCR assay (GeXP assay) was developed to detect simultaneously sixteen different respiratory virus types/subtypes. Seventeen sets of chimeric primers were used to initiate the RT-PCR, and one pair of universal primers was used for the subsequent cycles of the RT-PCR. The specificity of the GeXP assay was examined with positive controls for each virus type/subtype. The sensitivity was evaluated by performing the assay on serial ten-fold dilutions of in vitro-transcribed RNA of all RNA viruses and the plasmids containing the Adv and HBoV target sequence. GeXP assay was further evaluated using 126 clinical specimens and compared with Luminex xTAG RVP Fast assay. RESULTS: The GeXP assay achieved a sensitivity of 20-200 copies for a single virus and 1000 copies when all of the 16 pre-mixed viral targets were present. Analyses of 126 clinical specimens using the GeXP assay demonstrated that GeXP assay and the RVP Fast assay were in complete agreement for 109/126 (88.51%) of the specimens. GeXP assay was more sensitive than the RVP Fast assay for the detection of HRV and PIV3, and slightly less sensitive for the detection of HMPV, Adv, RSVB and HBoV. The whole process of the GeXP assay for the detection of 12 samples was completed within 2.5 hours. CONCLUSIONS: In conclusion, the GeXP assay is a rapid, cost-effective, sensitive, specific and high throughput method for the detection of respiratory virus infections.