A laser free self-luminous nanosystem for photodynamic therapy of cervical cancer cells.

Photodynamic therapy is a tumor treatment strategy. However, most of the photodynamic therapies rely on laser irradiation triggering, which limits their application in deep tissues. This study designed a self-luminescent nano system, hybrid protein oxygen nanocarrier coated graphene quantum dots (GQDs@HPOC) and mesoporous silica nanoparticles coated Luminol (L@MSNs), which self-assembled into GQDs@HPOC/L@MSNs without laser irradiation. The system utilized the weak acidic environment of tumors to trigger the release of Luminol and the chemiluminescence was catalyzed by HPOC. Next CRET occurred between Luminol and GQDs, producing 1O2, which could generate photodynamic damage to cervical cancer cells without the need for external laser irradiation. The system achieved the peak uptake in primary cervical cancer cells in 3 h, and had good biosafety before self-assembly. The system could significantly kill cells at a concentration of 16 µg/ml. The system will be further applied in in vivo experiments to investigate its therapeutic ability, providing a new strategy for the clinical treatment of cervical cancer.

On-Site Multisample Determination of Chlorogenic Acid in Green Coffee by Chemiluminiscent Imaging.

The potential of antioxidants in preventing several diseases has attracted great attention in recent years. Indeed, these products are part of a multi-billion industry. However, there is a lack of scientific information about safety, quality, doses, and changes over time. In the present work, a simple multisample methodology based on chemiluminiscent imaging to determine chlorogenic acid (CHLA) in green coffee samples has been proposed. The multi-chemiluminiscent response was obtained after a luminol-persulfate reaction at pH 10.8 in a multiplate followed by image capture with a charge-coupled device (CCD) camera as a readout system. The chemiluminiscent image was used as an analytical response by measuring the luminescent intensity at 0 °C with the CCD camera. Under the optimal conditions, the detection limit was 20 µM and precision was also adequate with RSD < 12%. The accuracy of the proposed system was evaluated by studying the matrix effect, using a standard addition method. Recoveries of chlorogenic acid ranged from 93-94%. The use of the CCD camera demonstrated advantages such as analysis by image inspection, portability, and easy-handling which is of particular relevance in the application for quality control in industries. Furthermore, multisample analysis was allowed by one single image saving time, energy, and cost. The proposed methodology is a promising sustainable analytical tool for quality control to ensure green coffee safety through dosage control and proper labelling preventing potential frauds.

Validation study of an automated chemiluminiscence assay to detect HIV antibodies in oral fluid specimens.

Oral fluid specimens (OF) have been widely used to know the HIV prevalence in several key populations. Here, we aim to validate in OF specimens an existing HIV chemiluminiscence assay for serum specimens. Paired OF and serum specimens were collected from 83 known HIV-positives and 83 known HIV-negatives in order to validate the performance characteristics of the automated chemiluminiscence Liaison XL Murex HIV Ag/Ab assay (Diasorin Inc, Iberia) for HIV antibody detection in OF specimens. Among the previously known HIV-seropositive group, HIV antibodies were detected in 69 out of 83 OF specimens. All serum and OF specimens collected from 83 HIV seronegative individuals were negative. The sensitivity and specificity of this assay were 83.13% and 100% respectively in OF. The PPV and NPV values were 100% and 85.57% respectively. The correlation obtained between both specimens was (K: 0.83, [95% CI: 0.748-0.915]) according to the kappa index. The ROC curve analysing the optimal cut-off of the Liaison XL Murex HIV Ag/Ab to detect positive OF specimens revealed that a cut-off of 0.497 showed sensitivity and specificity values of 98.8% and 97.59% respectively. Taking into account this cut-off, the overall sensitivity and NPV of the Liaison XL Murex HIV Ag/Ab assay could rise from 83.1 to 98.8% and from 85.5 to 97.7%, respectively. Our results suggest that the Liaison XL HIV Ag/Ab assay is suitable for the detection of HIV antibodies in OF specimens.

Liquid chromatography-tandem mass spectrometry method for quantification of gentamicin and its individual congeners in serum and comparison results with two immunoanalytical methods (fluorescence polarization immunoassay and chemiluminiscent microparticle immunoassay).

BACKGROUND: Total gentamicin is a sum of five congeners C1, C1a, C2, C2a and minor C2b, which differ from each other in their methylation on the purpurosamine ring. Liquid chromatography with mass detection (LC-MS/MS) and specified calibration material enables the concentration of total gentamicin and its individual congeners to be analysed. METHODS: 50 µL serum was precipitated with acetonitrile in the presence of 0.5 mol/L formic acid. A RP BEH C18 1.7 µm 2.1x50 mm column maintained at 30 °C and tobramicin as the internal standard were used. Mass detection was performed in positive electrospray. The gentamicin results were compared with fluorescence polarization immunoassay (FPIA) and chemiluminiscent microparticle immunoassay (CMIA). Passing-Bablock regression analysis and Bland-Altman analysis were used. RESULTS: Calibration curves for individual gentamicin congeners were linear with correlation coefficients between 0.997 and 0.998. Recovery was 91.6-102.0% and the coefficients of variation 1.4-8.4%. The total gentamicin concentration was compared with immunoassay FPIA (LC-MSgen = 0.9798xPFIAgen) and CMIA (LC MSgen = 0.9835xCMIAgen) both with significant correlation (p < 0.001). CONCLUSION: The LC-MS/MS method is fast and precise and can be applied to routine TDM in patients. Comparing it to immunoassays makes it possible to measure concentration of gentamicin congeners, which may be important in the case of their different pharmacokinetics.

Current approaches to measure nitric oxide in plants.

Nitric oxide (NO) is now established as an important signalling molecule in plants where it influences growth, development, and responses to stress. Despite extensive research, the most appropriate methods to measure and localize these signalling radicals are debated and still need investigation. Many confounding factors such as the presence of other reactive intermediates, scavenging enzymes, and compartmentation influence how accurately each can be measured. Further, these signalling radicals have short half-lives ranging from seconds to minutes based on the cellular redox condition. Hence, it is necessary to use sensitive and specific methods in order to understand the contribution of each signalling molecule to various biological processes. In this review, we summarize the current knowledge on NO measurement in plant samples, via various methods. We also discuss advantages, limitations, and wider applications of each method.

Establishment of chemiluminescence enzyme immunoassay for detecting human cardiac troponin I / 中国免疫学杂志

Objective:Two anti-human cardiac troponin I(cTnI)monoclonal antibodies were prepared to establish Luminol chemiluminescence enzyme immunoassay.Methods: Obtaining ascites monoclonal antibody was purified by ammonium sulfate fractionation and protein G affinity chromatography column, and their specificity was identified by SDS-PAGE and ELISA methods.Luminol chemiluminescence enzyme immunoassay was successfully established,which was used to detect 30 clinical serum samples.Results:Two antibodies named Ab1 and Ab3 could recognize different forms of cTnI including cTn I monomers,cTn I-C complexes and cTn I-T-C complexes.Both Ab1 and Ab3 are IgG1.The titers of the Ab1 and the Ab3 were up to 1:800 000 and 1:400 000,respectively.The affinity constants of Ab1 and Ab3 were 1.62×109L/mol and 2.60×108L/mol,respectively.The detection range of Lumino chemiluminescence enzyme immunoassay established by two monoclonal antibodies was 6.25 ng/ml to 400 ng/ml. Detecting 30 clinical samples attained the positive detection rate of 77.3% and the negative detection rate of 100%.Conclusion:The chemilu minescence enzyme immunoassay has been established to detect different forms of cTn I including cTn I monomer,cTn I-C complexes and cTn I-T-C complexes,which has better practicality.

Clinical Utility of Serum Homocysteine and Folate as Tumor Markers in Oral Squamous Cell Carcinoma - A Cross-Sectional Study.

INTRODUCTION: Oral Squamous Cell Carcinoma (OSCC) is a common malignancy involving head and neck. Identifying the markers of molecular levels or biochemical markers involving the various metabolic reactions associated with the initiation and biological behavior of individual tumors are very important in diagnosis and prognosis. AIM: To measure and compare the levels of serum Homocysteine (Hcy) and serum folate in OSCC patients, smoking group and healthy subjects and also to assess the clinical utility of serum Hcy as a potential tumor marker in OSCC. MATERIALS AND METHODS: The study group comprised of 60 subjects, of whom 30 were classified as OSCC cases (GROUP I) and 15 were classified as smokers without OSCC (GROUP II). The control group included 15 healthy individuals without smoking habit (Group III). Hcy was measured with High Performance Liquid Chromatography (HPLC). Folate estimation was done by Chemiluminiscence Immuno Assay (CLIA). Comparison of mean Hcy and folate values among the groups was done using ANOVA with Post-Hoc Games Howell test. Gender was compared using Chi-square test. Comparison of mean age was using ANOVA with Post-Hoc Tukey's test. RESULTS: The mean serum folate level in OSCC patients was 5.34ng/mL, 7.68ng/mL in smoking group and 10.99ng/mL in control group. There was a significant difference in the mean serum folate levels among the three study groups (p<0.001). The mean serum Hcy in OSCC patients was 23.58µmol/L, 17.46µmol/L, in smoking group and 10.76µmol/l in controls. There was a significant difference in the mean serum Hcy levels among the three study groups (p<0.001). CONCLUSION: The present study found an interesting association with serum Hcy and folate levels in OSCC which could be useful as a biochemical "Tumor Marker" and thereby providing insights into the onset and progression of the disease.

Capsaicin and tocopherol in red pepper seed oil enhances the thermal oxidative stability during frying.

Thermal oxidative stability of red pepper (Capsicum annuum) seed oil added with different levels of capsaicin or tocopherol as antioxidant during heating up to 48 h at 140±5°C was studied. Lipid oxidation of soy and pepper oil with different levels of capsaicin (0.12, 0.24%) and tocopherol (0.3, 0.6%) were evaluated during storage at 1400C for 0, 12, 24 and 48 h by monitoring peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and chemiluminiscence (CL). Capsaicin content of crude pepper oil (0.16 mg/ml) was much higher than that of commercial brands (0.004-0.02 mg/ml). Oleate content was significantly (p<0.05) higher in soy oil (53.7%) than pepper oil (9.5%), however, linoleate and linolenate contents were significantly (p<0.05) higher in pepper oil (70.6, 5.8%) than in soy oil (25.9, 5.8%). TBARS, PV, and CL of pepper oil were significantly (p<0.05) lower than soy oil after frying. TBARS and CL values of pepper oil with different levels of capsaicin or tocopherol showed significantly (p<0.05) lower values than untreated pepper oil during frying and storage. TBARS and CL values of 0.6% tocopherol treated pepper oil showed significantly (p<0.05) lower values than those of soy oil. The study suggests that capsaicin and tocopherol may play a key role to prevent the thermal oxidation of pepper oil during frying.