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1.
Eur Rev Med Pharmacol Sci ; 26(5): 1513-1523, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35302196

ABSTRACT

OBJECTIVE: Here, Bronco T (BT), a polyherbal formulation developed in 1984 for treating asthma, has been repurposed against septicemia-induced ALI. MATERIALS AND METHODS: Lipopolysaccharides (3 mg/kg BW) were injected intraperitoneally before 24 hours of surgery to assess the cardiorespiratory parameters, blood PaO2/FiO2 and MPO, pulmonary water content and histological changes in the lungs. The pentoxifylline (PTX) (25 mg/kg BW) was used as the positive control and given one hour before LPS. BT was given 3 hours (orally at different doses of 3, 1.5 and 0.75 g/kg BW) before LPS. RESULTS: The LPS treated group showed significant bradypnea, hypotension and bradycardia, through elongated peaks (RR) and (MAP) respectively and finally death after 95 minutes of LPS injection. The PTX and BT (3 g/kg BW) pretreatment significantly prevented these changes (dose-dependent in the BT group). The survival in these groups was maintained up to 190 min after LPS. The Pentoxifylline showed a better response (75%) than Bronco T (72%). In both the treatments, a significant decrease in pulmonary water content and minimal neutrophil infiltration and intact alveoli-capillary membrane was seen in the transverse section (T.S) of the lungs. CONCLUSIONS: Significant improvement was noted in survival time with lesser tissue damage and improved pulmonary function was observed by pre-treating with Bronco T in LPS induced septicemia.


Subject(s)
Acute Lung Injury , Pentoxifylline , Sepsis , Acute Lung Injury/pathology , Animals , Lipopolysaccharides/adverse effects , Lung/pathology , Pentoxifylline/pharmacology , Rats , Sepsis/chemically induced , Sepsis/drug therapy , Sepsis/pathology , Water
2.
Ecotoxicol Environ Saf ; 142: 95-101, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28395206

ABSTRACT

The zebrafish is gaining importance as a popular vertebrate model organism and is widely employed in ecotoxicological studies, especially for the biomonitoring of pollution in water bodies. There is limited data on the genetic mechanisms governing the adverse health effects in regards to an early developmental exposure to gamma radiation. In the present study zebrafish (Danio rerio) embryos were exposed to 1, 2.5, 5, 7.5 and 10Gy of gamma radiation at 3h post fertilization (hpf). Different developmental toxicity endpoints were investigated. Further, expression of genes associated with the development and DNA damage i.e. (sox2 sox19a and p53) were evaluated using Quantitative PCR (qPCR). The significant changes in the expression of sox2 sox19a and p53 genes were observed. This data was supported the developmental defects observed in the zebrafish embryo exposed to gamma radiation such as i.e. increased DNA damage, decreased hatching rate, increase in median hatching time, decreased body length, increased mortality rate, increased morphological deformities. Further, study shows that the potential ecotoxicological threat of gamma radiation on the early developmental stages of zebrafish. Further, it revealed that the above parameters can be used as predictive biomarkers of gamma radiation exposure.


Subject(s)
DNA Damage , Embryo, Nonmammalian/radiation effects , Gamma Rays/adverse effects , Zebrafish , Animals , Comet Assay , DNA Damage/genetics , Dose-Response Relationship, Radiation , Embryo, Nonmammalian/abnormalities , Embryo, Nonmammalian/pathology , Gene Expression Regulation, Developmental/radiation effects , Real-Time Polymerase Chain Reaction , Zebrafish/embryology , Zebrafish/genetics
3.
Sci Total Environ ; 596-597: 136-146, 2017 Oct 15.
Article in English | MEDLINE | ID: mdl-28431358

ABSTRACT

Methane leads to global warming owing to its warming potential higher than carbon dioxide (CO2). Rice fields represent the major source of methane (CH4) emission as the recent estimates range from 34 to 112 Tg CH4 per year. Biogenic methane is produced by anaerobic methanogenic archaea. Advances in high-throughput sequencing technologies and isolation methodologies enabled investigators to decipher methanogens to be unexpectedly diverse in phylogeny and ecology. Exploring the link between biogeochemical methane cycling and methanogen community dynamics can, therefore, provide a more effective mechanistic understanding of CH4 emission from rice fields. In this review, we summarize the current knowledge on the diversity and activity of methanogens, factors controlling their ecology, possible interactions between rice plants and methanogens, and their potential involvement in the source relationship of greenhouse gas emissions from rice fields.


Subject(s)
Archaea/physiology , Methane/biosynthesis , Oryza/microbiology , Soil Microbiology , Phylogeny
4.
Bioresour Technol ; 242: 351-358, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28284446

ABSTRACT

The main objective of this study was to evaluate the performance of wood charcoal as biofilter media under transient and high loading condition. Biofiltration of xylene was investigated for 150days in a laboratory scale unit packed with wood charcoal and inoculated with mixed microbial culture at the xylene loading rates ranged from 12 to 553gm-3h-1. The kinetic analysis of the xylene revealed absence of substrate inhibition and possibility of achieving higher elimination under optimum condition. The pH, temperature, pressure drop and CO2 production rate were regularly monitored during the experiments. Throughout experimental period, the removal efficiency (RE) was found to be in the range of 65-98.7% and the maximum elimination capacity (EC) was 405.7gm-3h-1. Molecular characterization results show Bacillus sp. as dominating microbial group in the biofilm.


Subject(s)
Charcoal , Xylenes , Biodegradation, Environmental , Filtration , Kinetics , Wood
5.
Rev Sci Instrum ; 87(12): 124703, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28040939

ABSTRACT

An Electric (E-) field sensor based on coplanar waveguide-fed microstrip antenna to measure E-field strength for dual-band operation at 914 MHz and 2.1 GHz is proposed, designed, and characterized. The parametric optimization of the design has been performed to obtain resonance at global system for mobile communication and universal mobile telecommunication system frequency band. Low return loss (-17 dB and -19 dB), appropriate gain (0.50 dB and 1.55 dB), and isotropic behaviour (directivity ∼ 1 dB), respectively, at 914 MHz and 2.1 GHz, are obtained for probing application. Antenna factor (AF) is used as an important parameter to characterize the performance of the E-field sensor. The AF measurement is explained in detail and results are reported. Finally, using the designed E-field sensor, the E-field strength measurements are carried out in a transverse electromagnetic cell. The key sources of uncertainties in the measurement are identified, evaluated, and incorporated into the final results. The measurement results are compared with theoretical values, which are found in good agreement. For comparative validation, the results are evaluated with reference to an already calibrated commercially available isotropic probe.

6.
Arch Environ Contam Toxicol ; 68(4): 612-21, 2015 May.
Article in English | MEDLINE | ID: mdl-25612551

ABSTRACT

Tributyltin chloride (TBTCl) has been used extensively as an antifouling agent in ship paints, which results in the contamination of aquatic sites. These contaminated sites serve as enrichment areas for TBTCl-resistant bacterial strains. One TBTCl-resistant bacterial strain was isolated from the sediments of Zuari estuary, Goa, India, which is a major hub of various ship-building activities. Based on biochemical characteristics and 16S rDNA sequence analysis, this bacterial strain was identified as Alcaligenes faecalis and designated as strain SD5. It could degrade ≥3 mM TBTCl by using it as a sole carbon source and transform it into the less toxic dibutyltin chloride, which was confirmed by nuclear magnetic resonance and mass spectroscopy. Interestingly, this bacterial strain also showed enhanced exopolysaccharide and siderophore production when cells were exposed to toxic levels of TBTCl, suggesting their involvement in conferring resistance to this antifouling biocide as well as degradative capability respectively.


Subject(s)
Alcaligenes faecalis/metabolism , Siderophores/metabolism , Trialkyltin Compounds/metabolism , Alcaligenes faecalis/classification , Estuaries , India , Siderophores/analysis , Trialkyltin Compounds/analysis
7.
Drug Res (Stuttg) ; 65(8): 428-31, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25350079

ABSTRACT

The difference in tissue distribution of Ketorolac and its enantiomers were investigated in wistar rats. Separate high performance liquid chromatographic method was developed and validated for determination of Ketorolac and its enantiomers. Oyster BDS (150 × 4.6 mm id., 5 µm particle size) column was used for determination of concentration of Ketorolac. Ketorolac enantiomers were determined using Chiral-AGP column (100 × 4.0 mm I.D., particle size 5 µ, Chrom tech Ltd, Sweden). Detection was done at wavelength of 322 nm using an ultraviolet detector in the analytical system. Ketorolac enantiomers exhibit difference in their disposition in Wistar rats. In kidney, there was a significant difference in pharmacokinetic parameters. The Cmax was nearly 4 times and AUC 0-∞ was found to be more than double for S (-) Ketorolac than that of R (+) Ketorolac. MRT, Ke and t1/2 differ significantly in kidney. In liver, Cmax was found to be approximately 69% higher for S (-) Ketorolac compared to R (+) Ketorolac. AUC 0-∞ did not differ significantly for the enantiomers in liver. In liver, S (-) Ketorolac eliminated very fast in comparison to R (+) Ketorolac having t1/2 (one third) in comparison to R (+) Ketorolac. In lungs, there was no difference observed for Cmax and other parameters but AUC 0-∞ was found to be marginally higher for S (-) ketorolac.


Subject(s)
Ketorolac/metabolism , Tissue Distribution/physiology , Animals , Male , Rats , Rats, Wistar , Stereoisomerism
8.
J Appl Microbiol ; 117(3): 750-65, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24848712

ABSTRACT

AIMS: The objective of this study was to investigate the influence of Cry1Ac gene expressing brinjal (VRBT-8) on the rhizospheric fungal community structure. METHODS AND RESULTS: qPCR indicated variations in the fungal ITS rRNA copy numbers of non-Bt (1·43-4·43) × 10(9) g(-1) dws and Bt (1·43-3·32) × 10(9) g(-1) dws plots. Phylogenetic analysis of ITS rRNA clones indicated fungal-related group majority of being Ascomycota compared to that of Basidiomycota and Zygomycota in non-Bt- and Bt-planted soils. Sordariomycetes was the dominant class detected in all the stages. CONCLUSIONS: Despite the variations in the population size and the distribution pattern observed across the non-Bt and Bt brinjal, plant-growth-dependent variability was more prominent compared with genetic modification. Therefore, this study concludes that genetic modification of brinjal crop has minor effect on the fungal community. SIGNIFICANCE AND IMPACT OF THE STUDY: Brinjal, the important solanaceous crop, is also prone to attack by many insect pests, especially by Leucinoides orbonalis, resulting in significant losses in the crop yield. However, the reports on the effect of transgenic crops and the associated microbial community are inconsistent. The present communication takes into account for the first time the possible interactions between Bt brinjal and the associated fungal community; the latter playing a significant role in maintaining soil fertility. As this study is limited to the structural diversity of fungal community, additional information regarding the functional diversity of the group seems imperative before recommending the commercialization of GM crops.


Subject(s)
Bacterial Proteins/genetics , Endotoxins/genetics , Fungi/classification , Hemolysin Proteins/genetics , Rhizosphere , Soil Microbiology , Solanum melongena/genetics , Bacillus thuringiensis Toxins , Bacterial Proteins/analysis , Bacterial Proteins/metabolism , Endotoxins/analysis , Endotoxins/metabolism , Fungi/genetics , Fungi/isolation & purification , Hemolysin Proteins/analysis , Hemolysin Proteins/metabolism , Molecular Sequence Data , Phylogeny , Plants, Genetically Modified
9.
Indian J Pharm Sci ; 75(1): 89-93, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23901166

ABSTRACT

A reliable, rapid and sensitive isocratic reverse phase high-performance liquid chromatography method has been developed and validated for assay of ketorolac tromethamine in tablets and ophthalmic dosage forms using diclofenac sodium as an internal standard. An isocratic separation of ketorolac tromethamine was achieved on Oyster BDS (150×4.6 mm i.d., 5 µm particle size) column using mobile phase of methanol:acetonitrile:sodium dihydrogen phosphate (20 mM; pH 5.5) (50:10:40, %v/v) at a flow rate of 1.0 ml/min. The eluents were monitored at 322 nm for ketorolac and at 282 nm for diclofenac sodium with a photodiode array detector. The retention times of ketorolac and diclofenac sodium were found to be 1.9 min and 4.6 min, respectively. Response was a linear function of drug concentration in the range of 0.01-15 µg/ml (R (2)=0.994; linear regression model using weighing factor 1/x (2)) with a limit of detection and quantification of 0.002 µg/ml and 0.007 µg/ml, respectively. The % recovery and % relative standard deviation values indicated the method was accurate and precise.

10.
Drug Res (Stuttg) ; 63(1): 34-7, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23447046

ABSTRACT

Ketorolac, a commonly used anti-inflammatory and analgesic agent, was studied in male wistar rats. The plasma samples were analysed using chiral AGP column with UV detection. The experimental data was analysed for probable fit in the compartmental and non-compartmental models using WinNolin software. The data of (+)-R-Ketorolac and (-)-S-Ketorolac was found to fit into the compartmental as well as non compartmental model. There was a difference between the plasma concentrations of (+)-R-Ketorolac and (-)-S-Ketorolac; the plasma concentrations of (+)-R-Ketorolac were higher than those of (-)-S-Ketorolac throughout the time course of the study. The area under the curve (AUC) of time vs. concentration profile of (+)-R-Ketorolac was found to be higher than (-)-S-Ketorolac. Volume of distribution and clearance was found to be higher for (-)-S-Ketorolac.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Ketorolac/pharmacokinetics , Animals , Injections, Intravenous , Ketorolac/administration & dosage , Male , Rats , Rats, Wistar , Stereoisomerism
11.
Lett Appl Microbiol ; 56(2): 99-104, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23163530

ABSTRACT

A lead-resistant bacteria isolated from soil contaminated with car battery waste were identified as Providencia alcalifaciens based on biochemical characteristics, FAME profile and 16S rRNA sequencing and designated as strain 2EA. It resists lead nitrate up to 0·0014 mol l(-1) by precipitating soluble lead as insoluble light brown solid. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometric analysis (SEM-EDX) and X-ray diffraction spectroscopy (XRD) revealed extracellular light brown precipitate as lead orthophosphate mineral, that is, Pb(9) (PO(4))(6) catalysed by phosphatase enzyme. This lead-resistant bacterial strain also demonstrated tolerance to high levels of cadmium and mercury along with multiple antibiotic resistance. Providencia alcalifaciens strain 2EA could be used for bioremediation of lead-contaminated environmental sites, as it can efficiently precipitate lead as lead phosphate.


Subject(s)
Lead/metabolism , Providencia/metabolism , Soil Microbiology , Soil Pollutants/metabolism , Biodegradation, Environmental , Cadmium/pharmacology , DNA, Bacterial/analysis , Lead/pharmacology , Mercury/pharmacology , Microscopy, Electron, Scanning , Nitrates/metabolism , Nitrates/pharmacology , Phosphates/metabolism , Providencia/drug effects , Providencia/genetics , Providencia/isolation & purification , RNA, Ribosomal, 16S/analysis , Soil/analysis , Soil Pollutants/analysis , Spectrometry, X-Ray Emission , X-Ray Diffraction
12.
Bull Environ Contam Toxicol ; 85(3): 295-300, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20665000

ABSTRACT

Spatial samples of surface and ground water collected from land disposal site of dye waste mixed sewage effluents at Binjhole, in Haryana, India were analyzed to evaluate its effect on quality of pond, hand pumps and ground waters for human health and irrigation purposes. It was found that average COD and TDS of dye houses discharge (310 and 3,920 mg/L) and treated sewage (428 and 1,470 mg/L) on mixing acquired the values of 245 and 1,780 mg/L and only Pb (0.24 microg/L) was above the permissible limit for irrigation purpose. Disposal of this mixed water to village pond changes the COD and TDS to 428 and 1,470 mg/L, respectively. COD and TDS of hand pump water samples were 264 and 1,190 mg/L, where as in tube well water these values were 151 and 900 mg/L. Though the ground water contamination seemed to decrease with the increasing distance from the pond but COD, TDS and BOD values continued to be quite high in water samples drawn from the hand pumps up to a distance of 500 m from pond. However, the major cause of the concern in these waters was Pb (0.11-0.45 ppm). Crops grown with this water shows accumulation of heavy metals like Pb,Cd, Fe, Mn, Ni, Cu, and Zn but in few crops they (Zn, Pb and Cd) exceed the safe limits. Regular consumption of these crop products may lead heavy metal toxicity. It was concluded from this study that the deep seepage of effluents led to deterioration of ground water quality for drinking purposes and the well waters rendered unfit for irrigation purposes within a span of 2 years. This warrants appropriate disposal measures for sewage and dye industry effluents in order to prevent deterioration of ground water and health of human and animals.


Subject(s)
Coloring Agents/analysis , Environmental Monitoring , Industrial Waste/analysis , Refuse Disposal , Sewage/chemistry , Water Pollutants, Chemical/analysis , Coloring Agents/toxicity , Crops, Agricultural/drug effects , Fresh Water/chemistry , India , Metals, Heavy/analysis , Metals, Heavy/toxicity , Particulate Matter/analysis , Particulate Matter/toxicity , Water Pollutants, Chemical/toxicity
13.
Indian J Surg ; 70(3): 142-3, 2008 Jun.
Article in English | MEDLINE | ID: mdl-23133043

ABSTRACT

Insertion of Ryles tube is a simple routine procedure. During its insertion, minor complications like trauma to nose, nasopharynx and oral cavity do happen from time to time. But as the Ryles tube is usually inserted blindly, potentially life threatening complications like inadvertent entry into trachea, cranial cavity and intravascular penetration have been reported. Folds and kinks may occur, but true knot of the Ryles tube, which we now report, is very rare.

14.
Lett Appl Microbiol ; 43(5): 571-7, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17032234

ABSTRACT

AIMS: The aim of the study was to isolate and characterize exopolysaccharide (EPS) produced by Vibrio harveyi strain VB23. METHODS AND RESULTS: Growth and EPS production by V. harveyi strain VB23, was studied in mineral salts medium supplemented with NaCl (1.5%) and glucose (0.2%). The rate of EPS production in batch cultures was highest during the late log phase of growth when compared with stationary growth phase. The exopolymer was recovered from the culture supernatant by using a cold ethanol precipitation-dialysis procedure. Chemical analyses of EPS revealed that it is primarily composed of neutral sugars, uronic acids, proteins and sulfates. The purified EPS revealed prominent functional reactive groups, such as hydroxyl, carboxylic and amides, which correspond to a typical heteropolymeric polysaccharide and the EPS, also possessed good emulsification activity. The gas chromatographic analysis of an alditol acetate-derivatized sample of EPS revealed that it is composed primarily of galactose and glucose. Minor components found were rhamnose, fucose, ribose, arabinose, xylose and mannose. CONCLUSIONS: The EPS produced by V. harveyi strain VB23 is a heteropolysaccharide possessing good emulsification activity. EPS was readily isolated from culture supernatants, which suggests that the EPS was a slime-like EPS. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of EPS characterization in luminous V. harveyi bacteria, which describes the isolation and characterization of an EPS expressed by V. harveyi. The results of the study contributes significantly towards an understanding of the chemical composition and applications of the EPS in environmental biotechnology and bioremediation.


Subject(s)
Polysaccharides, Bacterial/isolation & purification , Vibrio/metabolism , Emulsions , Polysaccharides, Bacterial/biosynthesis , Polysaccharides, Bacterial/chemistry , Spectroscopy, Fourier Transform Infrared
15.
Environ Int ; 28(6): 481-6, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12503913

ABSTRACT

Long-term irrigation with sewage water adds large amounts of carbon, major and micro- nutrients to the soil. We compared the spatial distribution of N, P, K and other micronutrients and toxic elements in the top 0.6 m of an alluvial soil along with their associated effects on the composition of crops and ground waters after about three decades of irrigation with domestic sewage effluent as a function of distance from the disposal point. Use of sewage for irrigation in various proportions improved the organic matter to 1.24-1.78% and fertility status of soils especially down to a distance of 1 km along the disposal channel. Build up in total N was up to 2908 kg ha(-1), available P (58 kg ha(-1)), total P (2115 kg ha(-1)), available K (305 kg ha(-1)) and total K (4712 kg ha(-1)) in surface 0.15 m soil. Vertical distribution of these parameters also varied, with most accumulations occurring in surface 0.3 m. Traces of NO3-N (up to 2.8 mg l(-1)), Pb (up to 0.35 mg l(-1)) and Mn (up to 0.23 mg l(-1)) could also be observed in well waters near the disposal point thus indicating initiation of ground water contamination. However, the contents of heavy metals in crops sampled from the area were below the permissible critical levels. Though the study confirms that the domestic sewage can effectively increase water resource for irrigation but there is a need for continuous monitoring of the concentrations of potentially toxic elements in soil, plants and ground water.


Subject(s)
Metals, Heavy/analysis , Nitrogen/analysis , Phosphorus/analysis , Sewage , Soil Pollutants/analysis , Waste Disposal, Fluid/methods , Water Supply , Agriculture , Conservation of Natural Resources , Metals, Heavy/pharmacokinetics , Plants , Tissue Distribution , Trace Elements/analysis
16.
Indian J Cancer ; 34(3): 136-8, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9491675

ABSTRACT

A 42 year old man presented with obstructive jaundice and cholangits. Ultrasonography (USG) revealed dilated intrahepatic biliary radicals and common bile duct (CBD). The bile duct also showed a curvilinear parallel intraluminal structure suggesting biliary ascariasis. The CBD was explored and a dead worm removed but jaundice persisted. Endoscopic retrograde cholangio pancreaticography (ERCP) was done showing a periampullary mass which on biopsy showed a villous adenoma with highly dysplastic changes. A Whipple's pancreaticoduodenectomy was performed and the growth proved to be a well differentiated periampullary adenocarcinoma.


Subject(s)
Ampulla of Vater/surgery , Ascariasis/complications , Common Bile Duct Diseases/parasitology , Common Bile Duct Neoplasms/surgery , Adult , Common Bile Duct Neoplasms/parasitology , Humans , Male
17.
World J Microbiol Biotechnol ; 11(3): 257-65, 1995 May.
Article in English | MEDLINE | ID: mdl-24414644

ABSTRACT

Many microorganisms have an inherent capacity to degrade the toxic organic compounds that enter the environment as a result of pollution and natural activities. Significant degradation of these compounds may take many years and it is frequently necessary to consider methods that can accelerate this process. There have been several demonstrations of enhanced biological degradation of toxic wastes, both in the laboratory and under field conditions. The prospects for enhanced biological cyanide degradation are reviewed. Compared with bench-scale processes, there are very few reports of field-scale processes for cyanide bioremediation. The implementation of such field-scale degradation requires inputs from biology, hydrology, geology, chemistry and civil engineering. A conceptual framework is emerging that can be adapted to develop new processes for bioremediation of toxic organic wastes. In terms of cyanide biodegradation, this framework incorporates identification of microbes, determination of the optimal conditions for degradation, establishment of the metabolic pathways involved in cyanide degradation, identification and localization of the genes involved, identification of suitable microbial strains for practical application and development of practical engineering processes. The present review addresses the progress that has been made in each of these aspects of cyanide biodegradation. It also examines the existing field applications of biological cyanide degradation and makes recommendations for future research.

18.
Environ Geochem Health ; 16(3-4): 229-33, 1994 Dec.
Article in English | MEDLINE | ID: mdl-24197217

ABSTRACT

The development of genetically engineered biosensors for copper and mercury ions is described. The biosensors have been constructed by fusing thelux or light emitting genes fromVibrio fischeri with genetic regulating elements that respond to copper ions or mercury ions, derived respectively fromEscherichia coli andSerratia marcescens. The fusions were placed intoE. coli cells which then emitted light in response to copper or mercury ions. Data is presented describing the sensitivity, specificity, and dynamic range of the biosensors to their respective target metal ions. A preliminary description of experiments is provided indicating how these biosensors might be used to investigate the bioavailability of mercury and copper ions in environmental samples.

19.
Biometals ; 5(1): 13-6, 1992.
Article in English | MEDLINE | ID: mdl-1392466

ABSTRACT

The impact of 2,4-dinitrophenol and chlorophenyl dimethylurea on ATP content, carbon fixation, O2 evolution, nitrogenase activity and Cr uptake of Anabaena doliolum has been studied. 2,4-Dinitrophenol has been found to be more toxic than chlorophenyldimethylurea for all these processes. However, when Cr toxicity to above variables was assessed in their presence the interaction was less than additive. An initial (10-15 min) concentration-dependent rapid Cr uptake, followed by a slow one, indicates a biphasic uptake. A significant inhibition of Cr uptake in the presence of both these metabolic inhibitors suggests the involvement of metabolic processes in Cr uptake.


Subject(s)
Anabaena/metabolism , Chromium/metabolism , Chromium/pharmacology , Dinitrophenols/pharmacology , Methylurea Compounds/pharmacology , 2,4-Dinitrophenol , Adenosine Triphosphate/metabolism , Anabaena/drug effects , Biological Transport/drug effects , Drug Interactions , Kinetics , Nitrogenase/metabolism , Oxygen/metabolism
20.
Biomed Environ Sci ; 3(2): 240-9, 1990 Jun.
Article in English | MEDLINE | ID: mdl-2129192

ABSTRACT

The toxic effects of chromium and tin salts on growth, 14C uptake, heterocyst differentiation, and nitrate reductase, nitrogenase, and glutamine synthetase activities of Anabaena doliolum and their regulation by pH, salinity, extracellular metabolites (spent), and organic acids have been studied. The toxicity of the test metals was lowered at alkaline pH and increased at acidic pH. NaCl at 20 mM was found to decrease metal toxicity. Extracellular metabolites (spent) in a 1:1 ratio (v/v) with fresh culture medium and organic acids were found to reduce metal toxicity. Among the various organic acids studied, humic acid was the most effective in regulating metal toxicity, apparently due to its multiple binding sites for metal cations. This study demonstrated that environmental factors, such as pH, salinity, extracellular metabolites, and organic acids, can mediate the toxicity of heavy metals to A. doliolum in a laboratory microcosm.


Subject(s)
Chromium/toxicity , Cyanobacteria/drug effects , Tin/toxicity , Acids/pharmacology , Hydrogen-Ion Concentration , Nitrate Reductase , Nitrate Reductases/drug effects , Nitrogenase/drug effects , Sodium Chloride/pharmacology
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