The Inhibition Effect of Tert-Butyl Alcohol on the TiO_2 Nano Assays Photoelectrocatalytic Degradation of Different Organics and Its Mechanism

The inhibition effect of tert-butyl alcohol(TBA), identified as the·OH radical inhibitor, on the TiO_2 nano assays(TNA) photoelectrocatalytic oxidation of different organics such as glucose and phthalate was reported. The adsorption performance of these organics on the TNA photoelectrode was investigated by using the instantaneous photocurrent value, and the degradation property was examined by using the exhausted reaction. The results showed that glucose exhibited the poor adsorption and easy degradation performance, phthalate showed the strong adsorption and harddegradation, but TBA showed the weak adsorption and was the most difficult to be degraded. The degradation of both glucose and phthalate could be inhibited evidently by TBA. But the effect on glucose was more obvious. The different inhibition effects of TBA on different organics could be attributed to the differences in the adsorption and the degradation property. For instance, phthalate of the strong adsorption property could avoid from the capture of·OH radicals by TBA in TNA photoelectrocatalytic process.

Endophytic actinobacteria of medicinal plant Aloe vera: Isolation, antimicrobial, antioxidant, cytotoxicity assays and taxonomic study

Objective: To explore the new sources of novel bioactive compounds having pharmaceutical and agricultural interest and to search the endophytic actinobacteria from medicinal plants. Methods: NAF-1 an endophyte actinobacteria was isolated from leaves of medicinal plant Aloe vera collected in Marrakesh, Morocco using Bennett agar as selective medium. NAF-1 was tested for its antimicrobial activity against five pathogenic bacteria such as Staphylococcus aureus PIC 53156, Micrococcus luteus ATCC381, Bacillus subtilis ATCC 14579, Pseudomonas aeruginosa DSM 50090 and Escherichia coli ATCC 8739 and four human clinic fungi belonging to the Candida, Aspergillus and Microsporum genera. Several antioxidant activities were studied such as DPPH free radical scavenging, β-carotene and linoleic acid and reducing power assays. The total of phenol and flavonoid was also calculated. Using Artemia salina shrimp assay, the cytotoxicity of NAF-1 crude extract was determined. Results: The results revealed that the actinobacteria showed a high activity(≥20 mm) against only Gram positive bacteria but it had a moderate activity(between 13 and 15 mm) against Human clinic fungi. The isolate also exhibited a LD50 of 14.20 μg/mL in the cytotoxicity assay. The result showed that the crude extract presented an interesting free radical-scavenging activity with IC50 value of(5.58 ± 0.26) μg/mL and a high value of phenolic and flavonoid compounds with(15.41 ± 0.18) μg GAE/mg extract and(11.41± 0.06) μg QE/mg extract respectively. Moreover, the taxonomic position of our endophyte actinobacteria using the morphological and physiological criteria and using 16 S r RNA gene sequence(polyphasic approach) showed that the NAF-1 isolate was similar to Streptomyces hydrogenans which was never described as an endophyte actinobacteria. Conclusions: This isolated strain appears promising resources of bioactive agents and can be exploited to produce therapeutic agents active against pathogenic disease.

不同载体微球在p300与RORγt Co-IP实验效率的比较

目的:在免疫共沉淀(Co-IP)过程中使用Protein A/G-琼脂糖珠捕获蛋白和使用Protein A/G-磁珠捕获蛋白的比较分析。方法先通过共转染Flag-p300和Myc-RORγt质粒入人胚肾细胞系293T(HEK293T)进行过表达,裂解细胞制备蛋白,分别使用Protein A/G-琼脂糖珠捕获蛋白和使用Protein A/G-磁珠捕获蛋白进行Co-IP;再通过分离人脐血单个核细胞诱导分化人辅助性T细胞17(Th17)进行Co-IP比较分析;通过CCK8实验排除转染试剂等对细胞活性毒性。结果过表达的HEK293T细胞和诱导分化的Th17细胞中均显示腺病毒E1A结合蛋白(p300)与维甲酸相关孤儿核受体(RORγt)在Co-IP过程中使用Protein A/G-磁珠捕获大分子的p300蛋白效果好于中分子的RORγt蛋白,使用Protein A/G-琼脂糖珠捕获中分子的RORγt蛋白效果好于大分子的p300蛋白。结论在Co-IP过程中使用Protein A/G-磁珠捕获大分子蛋白效果较好,使用Protein A/G-琼脂糖珠捕获中分子蛋白效果较好。

Performance and correlation of interferon gamma release assays and tuberculin skin test in HIV-infected children and adolescents with immune reconstitution

Objective:To evaluate the performance of interferon gamma release assays and tuberculin skin test in HIV-infected children and adolescents with immune reconstitution.Methods:A cross-sectional study was conducted in HIV-infected patients aged 5-18 years receiving antiretroviral treatment with CD4 T-lymphocytes>25%or>500 cells/mm3 for at least 6 months.QuantiF ERON-TB Gold,T-SPOT.TB,and tuberculin skin test were performed in each patient.Results:A total of 50 patients were enrolled with median age of 13.7 years,CD4 counts of 753(IQR:587-989)cells/mm3.Among 27 patients with tuberculosis(16)or tuberculosis exposure(11),8(29.6%)were positive to at least one test,2(7.4%)were positive QuantiFERON-TB Gold,3(11.1%)positive T-SPOT.TB,and 7(25.9%)had tuberculin skin test≥5 mm.Among 23 patients without history of tuberculosis or exposure,all had negative interferon gamma release assays,while 2(8.7%)had positive tuberculin skin test.Conclusions:All tests had low sensitivity despite immune reconstitution.

Current Status of Targets and Assays for Anti-HIV Drug Screening

HIV/AIDS is one of the most serious public health challenges globally. Despite the great efforts that are being devoted to prevent,treat and to better understand the disease,it is one of the main causes of morbidity and mortality worldwide. Currently,there are 30 drugs or combinations of drugs approved by FDA. Because of the side-effects,price and drug resistance,it is essential to discover new targets,to develop new technology and to find new anti-HIV drugs. This review summarizes the major targets and assays currently used in anti-HIV drug screening.

Interferon-gamma release assays in tuberculous uveitis:a comprehensive review

·Tuberculous uveitis(TBU)comprises a broad clinical spectrum of ocular manifestations,making its diagnosis challenging.Ophthalmologists usually require evidence from investigations to confirm or support a clinical diagnosis of TBU.Since direct isolation of the causative organism from ocular specimens has limitations owing to the small volume of the ocular specimens,resultant test positivities are low in yield.Immunodiagnostic tests,including the tuberculin skin test and interferon-gamma release assays(IGRAs),can help support a clinical diagnosis of TBU.Unlike the tuberculin skin test,IGRAs are in vitro tests that require a single visit and are not affected by prior Bacillus Calmette-Guerin vaccination.Currently,available IGRAs consist of different techniques and interpretation methods.Moreover,newer generations have been developed to improve the sensitivity and ability to detect active tuberculosis.This narrative review collates salient practice points as a reference for general ophthalmologists,such as evidence for the utilization of IGRAs in patients with suspected TBU,and summarizes basic knowledge and details of clinical applications of these tests in a clinical setting.

A novel fluorogenic probe for monoamine oxidase assays

Monoamine oxidase is flavoenzymes, widely distributed in mammals. It is well recognized that MAOs serve an important role in metabolism that they have close relationship with health .Along with the discoveries between MAOs and neurotic disease, more and more studies have been jumped in .In this paper, we design a new probe for assaying the activities of MAOs. The results showed that the probe [7-（3-aminopropoxy）coumarin] is simple, effective and sensitive for MAOB.

Response of Lymphocytes to Radiation in Untreated Breast Cancer Patients as Detected with Three Different Genetic Assays

Objective To detect the response of lymphocytes to radiation in untreated breast cancer patients with three different genetic assays. Methods Blood samples were collected from 25 untreated patients and 25 controls. Each blood sample was divided into two parts： one was irradiated by 3-Gy X-ray （irradiated sample）, the other was not irradiated （non-irradiated sample）. The radiosensitivity of lymphocytes was assessed by comet assay, cytokinesis-block micronucleus （CBMN） assay and 6-TG-resistant cells scored （TG） assay. Results The baseline values of micronucleated cell frequency （MCF） and micronucleus frequency （MNF） in the patients were significantly higher than those in the controls （P〈0.01）, and 3-Gy X-ray induced genetic damage to lymphocytes in the patients increased significantly as compared with that in the controls as detected with the three genetic assays （P〈0.01）. The proportion of radiosensitive cases in the patient group was 48% for the mean tail length （MTL）, 40% for the mean tall moment （MTM）, 40% for MCF, 44% for MNF, and 48% for mutation frequencies of the hprt gene （Mfs-hprt）, respectively, whereas the proportion of radiosensitive cases in the control group was only 8% for all the parameters. Conclusion The difference in the lymphocyte radiosensitivity between the breast cancer patients and the controls is significant. Moreover, there are wide individual variations in lymphocyte radiosensitivity of patients with breast cancer. In some cases, the radiosensitivity of the same patient may be different as detected with the different assays. It is suggested that multiple assays should be used to assess the radiosensitivity of patients with breast cancer before therapy.

Exploration of natural enzyme inhibitors with hypoglycemic potentials amongst Eucalyptus Spp. by in vitro assays

AIM: To investigate the presence and potency of natural enzyme inhibitors with hypoglycemic potentials amongst Eucalyptus Spp. by in vitro assays.METHODS: The leaf extracts of the three different Eucalyptus species [E. globulus(EG), E. citriodora(EC), E. camaldulensis(ECA)] were subjected to in vitro assay procedures to explore the prevalence of natural enzyme inhibitors(NEIs) after preliminary qualitative and quantitative phytochemical evaluations, to study their inhibitory actions against the enzymes like α-amylase, α-glucosidase, aldose reductase, angiotensin converting enzyme and dipeptidyl peptidase 4 playing pathogenic roles in type 2 diabetes. The antioxidant potential and total antioxidant capacity of the species were also evaluated.RESULTS: Major bioactive compounds like polyphenols(341.75 ± 3.63 to 496.85 ± 3.98) and flavonoids(4.89 ± 0.01 to 7.15 ± 0.02) were found in appreciable quantity in three species. Based on the IC50 values of the extracts under investigation, in all assays the effectivity was in the order of EG > ECA > EC. The results of the ferric reducing antioxidant power assay showed that the reducing ability of the species was also in the order of EG > ECA > EC. A strong correlation(R2 = 0.81-0.99) was found between the phenolic contents and the inhibitory potentials of the extracts against the targeted enzymes.CONCLUSION: These results show immense hypoglycemic potentiality of the Eucalyptus Spp. and a remarkable source of NEIs for a future phytotherapeutic approach in Type 2 diabetes.

Study on Immunochemical Assays for the Organophosphorus Insecticide Chlorpyrifos

The anti-chlorpyrifos polyclonal antibodies were obtained by using the artificial immuneantigen to immune in New Zealands white rabbits. The enzyme-tagged antibodies wereprepared by coupling horseradish peroxidase (HRP) to the purified antibody with themodified sodium periodate method. The indirect competitive enzyme linked immuno-sorbentassays (ELISA) and the HRP-tagged antibody direct ELISA (E-Ab) were established, respectively.The limit of detection (LOD) for the indirect ELISA and E-Ab were 0.0033 and 0.0042 gmL-1, respectively. The linear detection ranged well from 0.005 to 2.0 g mL-1.

Stability of fluorochrome based assays to measure subcellular sperm functions

Aim： To evaluate the long-term stability of the fluorescence signals of new fluorescence-based semen analysis assays for clinical application. Methods： Semen samples from 87 unselected infertile patients were used to perform the following assays： （i） detection of active caspase-3 （n = 17）; （ii） integrity of the mitochondrial membrane potential （MMP） （n = 17）; （iii） externalization of phosphatidylserine （EPS） （n = 16）; and （iv） detection of intact acrosomes via CD46 （n = 37）. After the assays, 4% paraformaldehyde was added to all aliquots. The fluorescence intensity of each sample was evaluated by flow cytometry on days 0, 3, 7, 10 and 14. Results： Differences of up to ± 5% positive spermatozoa from the value measured at day 0 were estimated as acceptable deviation. The Caspase-3 FLICA^TM showed mean differences 〈 5% at day 3, 7 and 10. At day 14 the mean difference was 7.6%. In contrast, the disrupted MMP and the EPS detection showed differences 〉 5% at day 3. The CD46-FITC labeling displayed absolute differences 〈 5% CD46-positive spermatozoa at days 3, 7, 10 and 14. Conclusion： Although immediate analysis of the fluorescence signals is recommended, it is possible to evaluate caspase-3 activation up to 10 days and CD46 up to 14 days after staining of sperm. The FACS evaluation of MMP and EPS detection should be conducted on the same day.

Development of PDMS-based Microfluidic Device for Cell-based Assays

In a single step photolithography, muhi-level microfluidic device is fabricated by printing novel architectures on a film photomasks. The whole fabrication process is executed by classical PCB technology without the need to access clean room facilities. Different levels of protruding features on PCB master are produced by exposing a photomask with specifically arranged "windows and rims" architectures, followed by chemical wet etching. Poly(dimethylsiloxane)(PDMS) is then molded against the positive relief master to generate microfluidic device featured with multi-level sandbag structure and peripheral microchannels. This sandbag structure is an analog to traditional dam or weir for particle entrapment. The microstructure does not collapse when subjected to applied pressure, which is suitable for operation on elastic PDMS substrate.Typical immunocytochemcial staining assays were performed in the microdevice to demonstrate the applicability of the sandbag structure for cellular analysis. This simplified microfabrication process employs low-cost materials and minimal specialized equipment and can reproducibly produce mask lines with about 20 μm in width, which is sufficient for most microfluidic applications.

Molecular Evaluation of the Enterotoxigenicity of <i>Clostridium difficile</i>and <i>Clostridium perfringens</i>Swine Isolates by PCR Assays

Clostridium difficile and C. perfringens are enteric pathogens affecting a variety of mammals. This study evaluated the molecular enterotoxigenicity of Clostridium swine isolates by PCRs. One hundred and ten swine faeces were analyzed by culture assay. The faecal samples were from sixty-seven healthy animals and 43 with gastrointestinal tract disease. C. difficile strains were PCR-screened for the presence of tcdA/tcdB and cdtA/cdtB genes. All C. perfringens isolates were tested for the characterization of the toxinotype. Overall, sixty-five swine resulted positive: 38 for C. difficile and 17 for C. perfringens. One sample tested C. perfringens and C. difficile-positive, at the same time: on the whole, 39 C. difficile strains were isolated. Thirty-eight C. difficile isolates (all from healthy animals) resulted tcdA/tcdB and cdtA/cdtB-negative by PCRs and toxins A/B-negative by immunological tests. All C. perfringens strains were type A;eight were also cpb2-positive. In the sample (diarrhoeic), with double infection, C. difficile tested tcdA/tcdB and cdtA/cdtB-positive by PCRs and toxins A/B-positive by immunoassays;C. perfringens resulted cpb2-positive. The molecular genotypeing/toxinotyping should be applied to establish a final diagnosis and to assess properly the full implications and the epidemiological impact of these findings in particular in samples of healthy animals and aid in the development of effective intervention methods for controlling clostridial disease outbreaks.

Development and Validation of Multiplex One-Step Real-Time TaqManqRT-PCR Assays for Detection and Quantification of Arboviral Encephalitis Viruses

Arboviral encephalitis is a group of animal and human illness that is mostly caused by several distinct families of viruses including orthobunya virus, phlebovirus, flaviviruses, and the alphaviruses. Although specific signs and symptoms vary by the type of central nervous system (CNS), initial signs and symptoms are very similar. Therefore rapid immunologic and molecular tools for differential diagnosis of arboviral encephalitis viruses are important for effective case management and control of the spread of encephalitis. The qRT-PCR assay, especially multiplex PCR, has the potential to produce considerable savings in time and resources in the laboratory detection. Meanwhile, the use of IC can prevent false negatives effectively by monitoring the processes of nucleic acid extraction and amplification. This report describes the development of a panel of internally controlled multiplex one-step real-time RT-PCR assays in which two virus specific-probe sets were used in the same reaction for the detection of 15 species arboviral encephalitis viruses: the comparative sensitivity of multiplex one-step qRT-PCR assays to single plex one-step qRT-PCR assays as well as one-step RT-PCR assays for detection of each viral species. And total of 150 human serum samples were detected to evaluate the multiplex one-step qRT-PCR assays. These multiplex one-step real-time RT-PCR assays with IC were evaluated in terms of sensitivity, linearity, precision, specificity, and also field samples including serum and vector. These assays can detect and differentiate arboviral encephalitis viruses by high throughput, sensitive, and specific way. It is useful for clinical management and outbreak control of arboviral encephalitis viruses and vector surveillance.

Analysis of Environmental Endocrine Disrupting Activities in Wastewater Treatment Plant Effluents Using Recombinant Yeast Assays Incorporated with Exogenous Metabolic Activation System

Objective To measure the endocrine disrupting chemicals （EDCs） in wastewater and evaluate the EDCs removal efficiencies in the municipal wastewater treatment plants （WWTP）. Methods A battery of in vitro recombinant yeast bioassays incorporated with exogenous metabolic activation system （rat liver preparation, S9 mix） was conducted to assess the estrogen receptor （ER）, androgen receptor （AR）, progesterone receptor （PR）, and thyroid receptor （TR） ant/agonistic activities of effluents collected from Datansha WWTP. Results The indirect estrogenic, anti‐androgenic, anti‐progesteronic, and anti‐thyroidic activities were observed in the influent. The removal efficiencies of EDCs were above 74%, suggesting that the present wastewater treatment processes were good enough to remove most of these indirect endocrine disrupting chemicals. Conclusion The incorporation of exogenous metabolic capacity into the test system was valid for the study of indirect effects on ER, AR, PR, and TR.

Development of time-resolved immunofluorometric assays for the detection of house dust mite-allergic IgE in human sera

Dermatophagoides farinae and D. pteronyssinus are the prevalent house dust mites (HDM) in tropical countries and are associated with allergic diseases. This investigation developed a time- resolved immunofluorometric assay (TR-IFMA) for the first time to detect specific IgE antibody in patients with skin prick test positive to HDM but no detectable IgE by other means. Levels of IgE to natural and recombinant HDM allergens were measured by TR-IFMA in 50 HDM-allergic patients and 19 healthy participants compared to sandwich enzyme-linked immunosorbent assay (ELISA). A recombinant allergen, rDerf2, showed a 14 kDa band corresponding to broad range proteins of natural HDM.TR-IFMA showed sensitivity lower than 0.35 kUA/l. TR-IFMA employing three HDM antigens showed good correlations with sandwich ELISA at R2 0.93-0.96. TR-IFMA detected HDM IgE in 62, 62, 25 percent of allergic patient serum sample compared to 28, 32, and 22 percent detected by ELISA result using three HDM allergen. TR-IFMA also detected 26.3, 31.6, and 5.3 percent positive samples from 19 healthy participants while ELISA showed 0, 5.3, and 0 percents IgE positive samples. The use of rDerf2 as an HDM allergen for the assay was verified with no statistically different from other HDM allergens. TR-IFMA showed lower detection limit than ELISA and yielded higher sensitivity for serum of people with allergic symptoms with no detectable HDM IgE. It is anticipated that TR-IFMA for HDM-specific IgE detection will play an important role in future diagnosis of HDM allergy in clinical laboratories and for different research purposes.

STABLE EXPRESSION OF HUMAN CYTOCHROME CYP2B6 AND CYP1A1 IN CHINESE HAMSTER CHL CELLS:THEIR USE IN MICRONUCLEUS ASSAYS

With specific designed prmers. CYP2B6 and CYP1A1 cDNA were generatecl by reverse transcrlI7tion-Polymerase chain reaction(RT-PCR )technlque Performed on total RNAs isolated frorn hum1ln liver and 3-rnethylch(,lanthrene(3-Mtt)induc human amnion FL, cells. Cell llnes (CHL, 2B6 and CtHL-1A1 ) capableof expressing hunlan cytochome P 15O (CYP ) 2B6 and 1A1 were establishecl after transfection of corre-sponding eukaryotic reconlbinant expression plasmid with human CYP2ll6 and 1A1 cDNA lnserts respectlvely. These cell lines stably expressed the mRNAs and the enzymatic activltles cc)rresI’onding to ttYP2B6and CYP1A1, respectively’ Compared with Chinese hamster lung (CHL) cells, the n1icr()nucleus frecluencyin CHl,-2B6 cells is markedly lncreased when exPosed to nitrosamines,aflatoxln B, (AFB1) and cyclophos-Phamide (CPA). Thls is also in CHL-1A1 cells,when exposed to carcinogenic polycycllc aromatic hydrocar-bons.

免疫亲和层析技术协同酶联免疫吸附法检测赭曲霉毒素A

利用免疫亲和层析技术(immunoaffinity chromatography,IAC)对样品中赭曲霉毒素A(ochratoxin A,OTA)进行捕获与浓缩,利用酶联免疫吸附(enzyme-linked immunosorbent assay,ELISA)法对IAC捕获的目标物OTA进行测定。IAC与ELISA中的抗OTA单克隆抗体来自不同的克隆株,分属不同独特型,与OTA结合靶点的选择性存在差异,IAC与ELISA协同检测,可以有效过滤OTA结构类似物造成的干扰,提高免疫分析的特异性与灵敏度。该方法用于加标样品测定时,OTA的检出限为0.2 ng/g,定量限为0.4 ng/g,OTA的平均回收率为75.9%,与单一的ELISA法相比,该方法虽然回收率略低,但灵敏度可以显著提高,达到ELISA法的60倍。通过对49份样品的实际检测,该方法检出阳性样品与国标法的符合率达到100%,漏检率为0%,由此可见,该方法在准确性上表现出明显的优势。作为一种综合免疫分析技术,该方法不需要大型仪器设备,对操作环境没有严格要求,便于基层实验室对样品中OTA的分析。

Cell Survival Assays for Individualised Chemotherapy in Primary Glioma Cultures—Colourmetric or Luminescent?

In vitro chemosensitivity testing of short term primary glioma cultures derived from brain biopsies is still in the research phase and has not yet found a place in clinical use. The main reasons for this slow progression are the small amounts of tissue available and the lack of a suitably sensitive assay capable of use in the clinical setting. This study examines whether the MTS and ATP cell survival assays, which determine cytotoxicity via colorimetric and luminescence analysis respectively, could potentially fulfill this role. Primary glioma cultures were tested for chemosensitivity using the MTS and ATP assays and were found to be generally sensitive to cisplatin and paclitaxel but relatively resistant to carmustine and etoposide. For both assays, LD50 values lay in the range 2 - 130 μg/ml but in the vast majority of cases, those obtained by the ATP assay were markedly lower those obtained by the MTS assay. Moreover, at cell numbers less than 2000 in the cases of paclitaxel and carmustine and less than 4500 in the case of cisplatin, these drugs were generally indicated as ineffective against the glioma cultures tested by the MTS assay but effective against these cultures by the ATP assay. These data clearly demonstrate that the ATP assay is more sensitive when estimating small cell numbers generated by primary glioma cultures from brain biopsies and more reliably detects higher kill rates by anticancer drugs. This study also supports the feasibility of using the ATP assay for chemosensitivity testing in a clinical setting.