FLUORIMETRIC DETERMINATION OF TETRACYCLINE IN SERUM AND URINE

The Eu-Tetracycline(TC)-TOPO-sodium dodecyl sulfonate(SDS)system was studied,Experiments showed that the maximum fluorescence intensity was obtained in the pH range of 7.5-8.7 and the concentrations of Eu^(a+),TOPO and SDS are 1.0×10^(-6)mol/L,1.0×10^(-8)mol/L and 1.0×10^(-8)mol/L,respectively,This fluorescence system can be used for the determination of TC in serum and urine,Beer's Law is obeyed in the range of 2.0×10^(-8)mol/L=1.0×10^(-6)mol/L for the concentration of TC. The determination limit is 1.2×10^(-8)mol/L,The composition and the luminescence mechanism were discussed.

HOMOGENEOUS ENZYME IMMUNOASSAY OF SERUM AFP BY FLUORIMETRIC KINETIC METHOD

The activity of the Ab-bound enzyme(HRP)changed after immunochemical reaction,and can be indicated by a sensitive fluorimetric kinetic method.The finding set the stage for developing sensitive homogeneous immunoassay.AFP was measured as an example.

A RAPID FLUORIMETRIC DETERMINATION OF TYROSINE IN SERUM BY THE REACTION WITH CERIUM (Ⅳ)

A fluorimetric method for the determination of tyrosine in serum was proposed. The fluoriscence intensity is a linear function of tyrosine content in the range 0-1. 44ug/ml. The percentage of recovery was satisfactory.

DEHYDRATION AND FLUORIMETRIC DETERMINATION OF ADRIAMYCIN

A dehydration reaction of ADM was carried out in sulfuric acid solution and an intensely fluorescent product was formed.This reaction was applied to the determination of ADM in body fluids.

Fluorimetric determination of methylmercury with 2, 3-dimercaptonaphthalene

Methylmercury is the most toxic one among the mercury species. Many methods including atomic absorption spectrometry, atomic emission spectrometry, atomic fluorescence spectrometry, gas chromatography, high\|performance liquid chromatography, ion chromatography, and capillary electrophoresis, have been published for the determination of methylmercury. These methods have been reviewed (Li, 1997; 1993; Niu, 1991). These methods require expensive equipment and highly qualified analysts. Although fluorimetric method is sensitive, inexpensive, easy to operate, no data about determination of methylmercury by fluorimetry can be found in the literature. In order to obtain a better method for the determination of methylmercury by fluorimetry, several reagents such as 8\| hydroxyquinoline, 8\|aminoquinoline, 8\|mercaptoquinoline, 2,3\| diaminonaphthalene, 2, 3\|dimercaptonaphthalene were tested. The 2, 3\|dimercaptonaphthalene gave better result than the other reagents. Under the optimal conditions, the concentration of 2, 3\| dimercaptonaphthalene was 5.6×10 -5 mol/L and the pH value of the solution was adjusted to 4.0 with acetate buffer solution. The excitation and emission fluorescence wavelengths of 2,3\| dimercaptonaphthalene-methylmercury complex were 512.5 nm and 500 nm(antistokes), respectively. The linear range was 0.3—80 ng/ml and the detection limit was 0.02 ng/ml. The relative standard deviation was 2.6%. The method may be applied to determine methylmercury in environmental samples, and detailed investigation is in progress.

Preliminary Fluorimetric Screening of Fourteen Palladium Complexes as Potential Antitumor Agents

Making use of the fact that the combination of a drug substance with DNA may inhibit the duplication, synthesis and proliferation of DNA and the consistency of the in vivo and in vitro interactions, the authors worked out a preliminary screening method for testing complex agents as potential antitumor drugs using ethidium bromide as a fluorescence probe. In this report, the method was applied for in vitro testing fourteen synthesized palladium(Ⅱ)/phenanthroline/amino acid/chloride complexes as potential non-platinum antitumor agents. The fluorimetric screening method was compared with methylene blue tube test and trypan blue dye exclusion assay. All three methods gave agreeable results. Among the complexes tested, [Pd(phen)(lys)]Cl, [Pd(phen)(arg)]Cl and [Pd(phen)(pro)]Cl showed antineoplastic ratios for animal tumor S-180 56%, 50% and 48%, respectively, in accordance with the order of their binding constants with DNA, 7.96×10~6, 4.52×10~6 and 1.0×10~6, respectively. The test results show that fluorimetric method is simple, cheap and rapid. suitable for preliminary screening of antitumor complexes.

Derivatization Reaction of Carbohydrates with Urea as the Reagent and Fluorimetric Determination of Carbohydrates

It is found that in the presence of sulfuric acid carbohydrates condense withurea to afford the condensation products, which emit fluorescence. Under optimum conditions, thefluorescence intensities of system are proportional to the concentrations of carbohydrates. Based onthis linear relationship, quantitative determination of kinds of carbohydrates has been made. Amongall the carbohydrates tested, the sensitivity of α-rhamnose is the highest and its limits ofdetection reaches 3. 5 * 10^(-8) mol/L. So α-rhamnose can be selectively determined in the presenceof other carbohydrates. A interaction mechanism is also discussed.

Quantitative Fluorimetric Analysis of Plant Nicotinamide

Fluorimetry was used to measure the amount of nicotinamide in plant samples. The nicotinamide was extracted and purified from plant tissues with ethyl acetate; converted to the fluorescent derivative, N 1 methylnicotinamide, by reacting with methyl iodide; and quantified according to its fluorescent strength. The nicotinamide in the leaf tissue of ten kinds of plants was measured, and the results showed that the nicotinamide content for different plants varied from 0.1 to 3.0 μg/g of fresh leaf weight. In addition, the crossing value of the fluorescent strength and the nicotinamide amount demonstrated that the linear correlation coefficient generally reached 0.997, with a detectable limit of 0.02 mg/L and the relative standard deviation of less than 9%. The results suggested that this method of quantifying nicotinamide in plants is useful and beneficial for functional research.

Protective Effect of Distillate and Redistillate of Cow’s Urine in Human Polymorphonuclear Leukocytes Challenged With Established Genotoxic Chemicals

Objective From the ancient period cow’urine has been used as a medicine. In Veda, cow’urine was compared to the nectar. In Susrut, several medicinal properties of cow’ urine have been mentioned and are known to cause weight loss, reversal of certain cardiac and kidney problems, indigestion, stomach ache, edema, etc. However, the literature and scripture did not mention the antigenotoxic properties of cow’urine. Methods In the present investigation, the antigenotoxic/ antioxidant properties of cow’ urine distillate and redistillate were studied in vitro. The antioxidant status and volatile fatty acid levels were determined. Actinomycin-D (0.1ol/L) and hydrogen peroxide (150 mol/L) were used for inducing DNA strand break with 0.1% DMSO as negative control. Dose for the antigenotoxic effect of cow’ urine was chosen from the dose response study carried out earlier. Results Both actinomycin-D and H2O2 caused statistically significant DNA unwinding of 80% & 75% respectively (P<0.001) as revealed by fluorimetric analysis of DNA unwinding (FADU), and the damage could be protected with the redistilled cow urine distillate (1, 50 & 100 ) in simultaneous treatment with genotoxic chemicals. Conclusion The redistillate of cowurine was found to possess total antioxidant status of around 2.6 mmol, contributed mainly by volatile fatty acids (1500 mg/L) as revealed by the GC-MS studies. These fatty acids and other antioxidants might cause the observed protective effects.

Naringin ameliorates acetic acid induced colitis through modulation of endogenous oxido-nitrosative balance and DNA damage in rats

The aim of this study was to evaluate the effect of naringin on experimentally induced inflammatory bowel dis- ease in rats. Naringin （20, 40 and 80 mg/kg） was given orally for 7 days to Wistar rats before induction of colitis by intrarectal instillation of 2 mL of 4% （v/v） acetic acid solution. The degree of colonic mucosal damage was analyzed by examining mucosal damage, ulcer area, ulcer index and stool consistency. Intrarectal administration of 4% acetic acid resulted in significant modulation of serum alkaline phosphatase, lactate dehydrogenase, superoxide dismutase （SOD）, glutathione （GSH）, malondialdehyde （MDA） and myeloperoxidase （MPO） content along with colonic nitric oxide （NO）, xanthine oxidase （XO） level and protein carbonyl content in the colonic tissue as well as in blood. Naringin （40 and 80 mg/kg） exerted a dose dependent （P 〈 0.05） ameliorative effect, as it significantly increased hematological parameter as well as colonic SOD and GSH. There was a significant （P 〈 0.05） and dose dependant inhibition of macroscopical score, ulcer area along with colonic MDA, MPO activity by the 7 days of pretreatment of naringin （40 and 80 mg/kg）. Biochemical studies revealed a significant （P 〈 0.05） dose dependant inhibition in serum alkaline phosphatase （ALP） and lactate dehydrogenase （LDH） levels by pretreatment of naringin. Increased levels of colonic NO, XO, protein carbonyl content and DNA damage were also sig- nificantly decreased by naringin pretreatment. The findings of the present investigation propose that naringin has an anti-inflammatory, anti-oxidant and anti-apoptotic potential effect at colorectal sites as it modulates the production and expression of oxidative mediators such as MDA, MPO, NO and XO, thus reducing DNA damage.

Genotoxicity of Pesticide Waste Contaminated Soil and Its Leachate

Objective Improper land disposal of hazardous waste can result in leaching of hazardous constituents which may contaminate ground and surface water leading to adverse impact on human health and environment consequences. The present study utilized mammalian cell culture for the genotoxicity assessment of waste and its leachate. Methods Genotoxic potential and chemical analysis of pesticide derived tarry waste contaminated soil extract and its leachate was assessed using in vitro human lymphocyte cultures and GC-MS. Results The investigation revealed that the soil extract could cause significant to highly significant genotoxicity in the form of DNA strand break at 25 mL (P<0.01), 50 mL, 100 mL and 200 mL (P<0.001) and chromosomal aberration at 25 mL (P<0.01) and 50 mL and 100 mL (P<0.001). The leachate could cause significant DNA strand break and chromosomal aberration only at 100 mL and 200 mL (P<0.01) dose levels. Conclusion The genotoxicity observed is attributed to carbaril and tetra methyl naphthyl carbamate, the major ingredients of the extracts, as revealed by GC-MS.

DNA Damage Caused By Pesticide-contaminated Soil

Objective To determine the DNA damaging potential and the genotoxicity of individual compounds in pesticide contaminated soil. Methods In the present study, DNA damaging potential of pesticide-contaminated soil and the genotoxicity of individual compounds present in the soil were assessed using fluofimetdc analysis of DNA unwinding assay. Results The contaminated soil sample showed 79% （P〈0.001） of DNA strand break, whereas technical grade of major catbaryl and α-naphthol constituents of the contaminated soil showed 64% （P〈0.01） and 60% （P〈0.02） damage respectively. Conclusion Our results indicate that the toxicity caused by contaminated soil is mainly due to carbatyl and α -napthol, which are the major constituents of the soil sample analyzed by CrC-MS.

Mobile mini-fluorimeter for antibiotic aptasensing based on surface-plasmonic effect of burlike nanogolds enhanced by digitized imaging diagnosis

Antibiotic abuse now poses a grave threat to global ecology and bestirs public concerns about the residue issue in daily necessities.The traceability measurements along supply chain or logistic circulation have become increasingly essential given the labile nature of diverse synthetic residuals on site.In an attempt to answer this urgency,here a miniaturized fluorometric aptasensor prototype was contrived that catered to the point-of-care screening norm for two typical additives:chloramphenicol and enrofloxacin.The key target-indicating module worked in vitro based on the competitive binding-induced fluorescence recovery of fluorescein-labeled aptamers,which were photobleached beforehand in the format of double helix on burlike nanogold carriers.The“prickly”geometry of the latter not just enriched the capture probes at preferentially substrate-accessible spires;but also contributed to a tip-enhanced surface plasmon effect,sensitizing the signal-on during the duplex dissociation even at nanomolar threshold of the analytes.On the other hand,to encompass a full portable,a set of optical devices were mounted within a 3D-printed cartridge(adaptor)to converge the light beam and route it towards the detector,for which the smartphone camera came up in handy with a home-developed App for calibrating the emissive brightness.Enlightened by the high-dynamic-range compression,an imaging diagnostic algorithm was built in to grid and digitize each slide in the album for augmented detection performance.Thus,a novel bio-to-silico integration was invented that capable of in situ rapid reporting on the antibiotic presence with high sensitivity and selectivity.Further field practices in spiked milk on sales proved the precision and rudimentary feasibility of the well-assembled model of appliance,thus holding nice prospects in nonexpert(e.g.,family and local community)utilities for foodborne antibiotic identification.

FLUORESCENCE ENHANCEMENT OF THE TERBIUM(Ⅲ)-TIRON BINARY COMPLEX BY LANTHANUM(Ⅲ),GADOLINIUM(Ⅲ),LUTETIUM(Ⅲ) AND YTTRIUM(Ⅲ) AND ITS APPLICATIONS

I. INTRODUCTION Recently, it has been found that in the solution some of lanthanides, yttrium and alkaline earth metal ions can enhance the intrinsic fluorescence of a lanthanide complex, improving its analytical characteristics. In some co-fluorescence systems the