| 1. |
- Islam, Khairul, et al.
(författare)
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Dose-response relationship between arsenic exposure and the serum enzymes for liver function tests in the individuals exposed to arsenic : a cross sectional study in Bangladesh
- 2011
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic arsenic exposure has been shown to cause liver damage. However, serum hepatic enzyme activity as recognized on liver function tests (LFTs) showing a dose-response relationship with arsenic exposure has not yet been clearly documented. The aim of our study was to investigate the dose-response relationship between arsenic exposure and major serum enzyme marker activity associated with LFTs in the population living in arsenic-endemic areas in Bangladesh. Methods: A total of 200 residents living in arsenic-endemic areas in Bangladesh were selected as study subjects. Arsenic concentrations in the drinking water, hair and nails were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The study subjects were stratified into quartile groups as follows, based on concentrations of arsenic in the drinking water, as well as in subjects' hair and nails: lowest, low, medium and high. The serum hepatic enzyme activities of alkaline phosphatase (ALP), aspartate transaminase (AST) and alanine transaminase (ALT) were then assayed. Results: Arsenic concentrations in the subjects' hair and nails were positively correlated with arsenic levels in the drinking water. As regards the exposure-response relationship with arsenic in the drinking water, the respective activities of ALP, AST and ALT were found to be significantly increased in the high-exposure groups compared to the lowest-exposure groups before and after adjustments were made for different covariates. With internal exposure markers (arsenic in hair and nails), the ALP, AST and ALT activity profiles assumed a similar shape of dose-response relationship, with very few differences seen in the higher groups compared to the lowest group, most likely due to the temporalities of exposure metrics. Conclusions: The present study demonstrated that arsenic concentrations in the drinking water were strongly correlated with arsenic concentrations in the subjects' hair and nails. Further, this study revealed a novel exposure- and dose- response relationship between arsenic exposure metrics and serum hepatic enzyme activity. Elevated serum hepatic enzyme activities in the higher exposure gradients provided new insights into arsenic-induced liver toxicity that might be helpful for the early prognosis of arsenic-induced liver diseases.
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| 2. |
- Ahmed, Bulbul, et al.
(författare)
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A review on natural sweetener plant - Stevia having medical and commercial importance
- 2011
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Ingår i: Agronomy Journal. - : Croatian society of agronomist. - 0002-1954. ; 73:1-2, s. 75-91
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Forskningsöversikt (refereegranskat)abstract
- Stevia is a perennial herb that belongs to the Asteraceae family. It is a natural sweetener plant and estimated to be 300 times sweeter than cane sugar. The leaves of stevia are the source of diterpene glycosides, viz. stevioside and rebaudioside. Stevioside is regenerated as a valuable natural sweetening agent because of its relatively good taste and chemical stability. Now it is being cultivated in Japan, Taiwan, Philippines, Hawaii, Malaysia and overall South America for food and pharmaceutical products. Products can be added to tea and coffee, cooked or baked goods, processed foods and beverages, fruit juices,
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| 3. |
- Ahmed, Bulbul, et al.
(författare)
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Establishment of an Indirect Genetic Transformation Method for Arabidopsis thaliana ecotype Bangladesh
- 2011
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Ingår i: Journal of Central European Agriculture. - : Journal of Central Europian Agriculture (JCEA). - 1332-9049. ; 12:3, s. 519-528
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Tidskriftsartikel (refereegranskat)abstract
- Arabidopsis thaliana is a small flowering plant belonging to the Brassicaceae family, which is adopted as a model plant for genetic research. Agrobacterium tumifaciensmediated transformation method for A. thaliana ecotype Bangladesh was established. Leaf discs of A. thaliana were incubated with A. tumefaciens strain LBA4404 containing chimeric nos. nptII. nos and intron-GUS genes. Following inoculation and co-cultivation, leaf discs were cultured on selection medium containing 50 mg/l kanamycin + 50 mg/l cefotaxime + 1.5 mg/l NAA and kanamycin resistant shoots were induced from the leaf discs after two weeks. Shoot regeneration was achieved after transferring the tissues onto fresh medium of the same combination. Finally, the shoots were rooted on MS medium containing 50 mg/l kanamycin. Incorporation and expression of the transgenes were confirmed by PCR analysis. Using this protocol, transgenic A. thaliana plants can be obtained and indicates that genomic transformation in higher plants is possible through insertion of desired gene. Although Agrobacterium mediated genetic transformation is established for A. thaliana, this study was the conducted to transform A. thaliana ecotype Bangladesh.
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| 4. |
- Ali, Nurshad, et al.
(författare)
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Association between arsenic exposure and plasma cholinesterase activity : a population based study in Bangladesh
- 2010
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Arsenic is a potent pollutant that has caused an environmental catastrophe in certain parts of the world including Bangladesh where millions of people are presently at risk due to drinking water contaminated by arsenic. Chronic arsenic exposure has been scientifically shown as a cause for liver damage, cancers, neurological disorders and several other ailments. The relationship between plasma cholinesterase (PChE) activity and arsenic exposure has not yet been clearly documented. However, decreased PChE activity has been found in patients suffering liver dysfunction, heart attack, cancer metastasis and neurotoxicity. Therefore, in this study, we evaluated the PChE activity in individuals exposed to arsenic via drinking water in Bangladesh.Methods: A total of 141 Bangladeshi residents living in arsenic endemic areas with the mean arsenic exposure of 14.10 ± 3.27 years were selected as study subjects and split into tertile groups based on three water arsenic concentrations: low (< 129 μg/L), medium (130-264 μg/L) and high (> 265 μg/L). Study subjects were further sub-divided into two groups (≤50 μg/L and > 50 μg/L) based on the recommended upper limit of water arsenic concentration (50 μg/L) in Bangladesh. Blood samples were collected from the study subjects by venipuncture and arsenic concentrations in drinking water, hair and nail samples were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). PChE activity was assayed by spectrophotometer.Results: Arsenic concentrations in hair and nails were positively correlated with the arsenic levels in drinking water. Significant decreases in PChE activity were observed with increasing concentrations of arsenic in water, hair and nails. The average levels of PChE activity in low, medium and high arsenic exposure groups were also significantly different between each group. Lower levels of PChE activity were also observed in the > 50 μg/L group compared to the ≤50 μg/L group. Moreover, PChE activity was significantly decreased in the skin (+) symptoms group compared to those without (-).Conclusions: We found a significant inverse relationship between arsenic exposure and PChE activity in a human population in Bangladesh. This research demonstrates a novel exposure-response relationship between arsenic and PChE activity which may explain one of the biological mechanisms through which arsenic exerts its neuro-and hepatotoxicity in humans.
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| 5. |
- Bari, M. A., et al.
(författare)
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Antibacterial and Antifungal Activity of Solanum torvum (Solanaceae)
- 2010
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Ingår i: International Journal of Agriculture & Biology. - : Friends Science Publishers. - 1560-8530. ; 12:3, s. 386-390
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Tidskriftsartikel (refereegranskat)abstract
- Leaves, stem, roots and inflorescence of Solanum torvum Sw. were extracted in two different organic solvents (chloroform & methanol). Antibacterial and antifungal effects of the extracts were tested on fifteen (six Gram positive & nine Gram negative) human pathogenic bacteria and on eight pathogenic fungi. Methanolic extracts of roots of S. torvum exhibited promising antibacterial and antifungal effects on all organisms tested in comparison with that observed in the leaves, stems and inflorescence extracts. The toxicity of the extracts was in the following order; root>stem>inflorescence>leaf. The minimum inhibitory concentration (MIC) values of methanolic extract of roots of S. torvum were in the range between 64-128 µg mL -1 . Chloroform extracts of roots were more toxic (LC 50 35.4629 ppm) than other extracts analyzed in Brine shrimp test. In conclusion, S. torvum appears to be an attractive material for the development of antimicrobial drugs and environment friendly biopesticides.
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| 6. |
- Biswas, M. K., et al.
(författare)
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In exploitation of genetic diversity in potato breeding
- 2010
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Ingår i: Agronomski Glasnik (Agronomy Journal). - Zagreb : Hrvatsko agronomsko društvo. - 1848-8900. ; 72:4-5, s. 261-276
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Tidskriftsartikel (refereegranskat)abstract
- With a view to select divergent parents genetic diversity was estimated among twenty genotypes. Thirty F1 progenies developed by line-tester mating were studied from seedling generation to first clonal generation for five important agronomic traits. Cluster analysis reveals that the parents could be grouped into seven different clusters. Cluster means showed wide range of variation for several traits among singles as well as multi genotypic clusters. Considering diversity pattern, parents should select from cluster I, III, IV, and V for the improvement of potato. Analysis of variance revealed that all most all the sources of variation were highly significant for all the studied traits in both generations. Parents Challisha, Lalpakri, Patnai, Chamak, Sadagoti, TPS-67 and TPS-364 were found to be good general combiners for tuber yield and yield contribution traits due to their gca effects. The sca effects showed that out of 30 hybrids 12 were found to have specific combining ability for tuber yield and those hybrids also exhibited considerable heterosis for tuber yield and yield contributing traits.
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| 7. |
- Butenko, Melinka A., et al.
(författare)
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Inflorescence deficient in abscission controls floral organ abscission in Arabidopsis and identifies a novel family of putative Ligands in Plants
- 2003
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Ingår i: The Plant Cell. - : American Society of Plant Biologists. - 1040-4651 .- 1532-298X. ; 15:10, s. 2296-2307
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Tidskriftsartikel (refereegranskat)abstract
- Abscission is an active process that enables plants to shed unwanted organs. Because the purpose of the flower is to facilitate pollination, it often is abscised after fertilization. We have identified an Arabidopsis ethylene-sensitive mutant, inflorescence deficient in abscission (ida), in which floral organs remain attached to the plant body after the shedding of mature seeds, even though a floral abscission zone develops. The IDA gene, positioned in the genomic DNA flanking the single T-DNA present in the ida line, was identified by complementation. The gene encodes a small protein with an N-terminal signal peptide, suggesting that the IDA protein is the ligand of an unknown receptor involved in the developmental control of floral abscission. We have identified Arabidopsis genes, and cDNAs from a variety of plant species, that encode similar proteins, which are distinct from known ligands. IDA and the IDA-like proteins may represent a new class of ligands in plants
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| 8. |
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| 9. |
- Das, Umi, et al.
(författare)
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Computational characterization and expression profile of MTP1 gene associated with zinc homeostasis across dicot plant species
- 2021
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Ingår i: Gene Reports. - : Elsevier. - 2452-0144. ; 23, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- This study characterizes different MTP1 (metal tolerance protein)/ZAT (zinc transporter) homologs involved in zinc (Zn) homeostasis in plants. BLAST analysis of AtMTP1 protein against 15 plant species showed 21 MTP1 homologs. These MTP1 protein homologs generally contain ~400 residues, six transmembrane helices and cation transmembrane transporter activity (GO:0008324), which can be utilized in predicting Zn uptake and tolerance mechanisms. These MTP1 genes having 1 exon are located on chromosomes 2, 7, and 14. Motifs contain conserved sequences of 41–50 residues belonging to the cation efflux family, which may help target binding sites and transcription factors. Further, AtMTP1 shows close similarities with Glycine max and Medicago trunculata. Interactome analysis suggests the association of AtMTP1 with cadmium/zinc-transporting ATPase and ZIP metal ion transporter. The AtMTP1 network is predominantly connected to cadmium/zinc-transporting ATPase (heavy metal ATPase 2, HMA2; heavy metal ATPase 3, HMA3; heavy metal ATPase 4, HMA4), cation efflux protein (MTP11), and metal tolerance protein C3 (AT4G58060). The Genevestigator predicts the high expression potential of AtMTP1 in the apical root during senescence, seedling, and bolting stages in an association with 11 co-expressed genes, mainly linked to estradiol toxicity and heat stress. Besides, AtMTP1 protein homologs possess conserved N-glyco motifs and physicochemical properties. The similarity and interactions of AtMTP1 gene with other genes suggest that Zn homeostasis in plants is associated with the regulation of different genes. These findings may advance our understanding to further develop plants capable of maintaining Zn homeostasis under adverse conditions. © 2021 Elsevier Inc.
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| 10. |
- Desale, Prithviraj, et al.
(författare)
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Biosorption of Heavy Metals by Actinomycetes for Treatment of Industrial Effluents
- 2012
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Konferensbidrag (refereegranskat)abstract
- Rapid industrialization usually is the cause of increase in pollutants in the natural river bodies. This pollution is attributed to lack of improper treatment and inadequate disposal mechanisms of the waste generated thereof. The aim of present investigation was to screen actinomycetes for their ability to adsorb heavy metals. Actinomycetes belong to most diverse group of filamentous prokaryotes with ubiquitous presence in different ecological niches. This ubiquity is due to their ability to degrade almost any type of polymer and to use several compounds as carbon sources. Nearly 200 actinomycetes from different niches like fresh water, soda lake, geothermal springs, acid soils, etc from different locations in India were screened for ability to grow in presence of 1 to 5 mM of heavy metals like Cd, Hg, Pb, Ni, Sr, Fe, Mo, Zn and Mn. Most of the strains tolerant to heavy metals belonged to the genus Streptomyces spp. Five strains could grow in presence of 5 mM Cd2+, 4 strains in presence of 0.1 mM Hg2+, 18 strains in presence of 5 mM Pb2+, 21 strains in presence of 5 mM Ni2+, whereas 34 strains grew in presence of 5 mM Fe2+. One of the most promising strain was studied for its ability to absorb cadmium where 2x1011 cells or spores could adsorb 0.32 mM to 0.33 mM of cadmium. Spores and vegetative cells showed nearly similar level of adsorbtion ability. This strain can be very useful in developing a bioreactor for the adsorption of heavy metals from industrial effluents containing cadmium.
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| 11. |
- Desale, Prithviraj, et al.
(författare)
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Biosorption of nickel by Lysinibacillus sp. BA2 native to bauxite mine
- 2014
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier. - 0147-6513 .- 1090-2414. ; 107, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- The current scenario of environmental pollution urges the need for an effective solution for toxic heavy metal removal from industrial wastewater. Bioremediation is the most cost effective process employed by the use of microbes especially bacteria resistant to toxic metals. In this study, Lysinibacillus sp. BA2, a nickel tolerant strain isolated from bauxite mine was used for the biosorption of Ni(II). Lysinibacillus sp. BA2 biomass had isoelectric point (pI) of 3.3. The maximum negative zeta potential value (−39.45) was obtained at pH 6.0 which was highly favourable for Ni(II) biosorption. 238.04 mg of Ni(II) adsorbed on one gram of dead biomass and 196.32 mg adsorbed on one gram of live biomass. The adsorption of Ni(II) on biomass increased with time and attained saturation after 180 min with rapid biosorption in initial 30 min. The Langmuir and Freundlich isotherms could fit well for biosorption of Ni(II) by dead biomass while Langmuir isotherm provided a better fit for live biomass based on correlation coefficient values. The kinetic studies of Ni(II) removal, using dead and live biomass was well explained by second-order kinetic model. Ni(II) adsorption on live biomass was confirmed by SEM-EDX where cell aggregation and increasing irregularity of cell morphology was observed even though cells were in non-growing state. The FTIR analysis of biomass revealed the presence of carboxyl, hydroxyl and amino groups, which seem responsible for biosorption of Ni(II). The beads made using dead biomass of Lysinibacillus sp. BA2 could efficiently remove Ni(II) from effluent solutions. These microbial cells can substitute expensive methods for treating nickel contaminated industrial wastewaters.
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| 12. |
- Ghosal, Anubrata, et al.
(författare)
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RNA interference and its therapeutic potential
- 2011
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Ingår i: Central European Journal of Medicine. - : Versita. - 1895-1058 .- 1644-3640. ; 6:2, s. 137-147
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Forskningsöversikt (refereegranskat)abstract
- RNA interference is a technique that has become popular in the past few years. This is a biological method to detect the activity of a specific gene within a cell. RNAi is the introduction of homologous double stranded RNA to specifically target a gene’s product resulting in null or hypomorphic phenotypes. This technique involves the degradation of specific mRNA by using small interfering RNA. Both microRNA (miRNA) and small interfering RNA (siRNA) are directly related to RNA interference. RNAi mechanism is being explored as a new technique for suppressing gene expression. It is an important issue in the treatment of various diseases. This review considers different aspects of RNAi technique including its history of discovery, molecular mechanism, gene expression study, advantages of this technique against previously used techniques, barrier associated with this technique, and its therapeutic application.
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| 13. |
- Hossain, Monayem, et al.
(författare)
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Silicon alleviates arsenic-induced toxicity in wheat through vacuolar sequestration and ROS scavenging
- 2018
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Ingår i: International journal of phytoremediation. - : Taylor & Francis. - 1522-6514 .- 1549-7879. ; 20:8, s. 796-804
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic (As) is a phytotoxic element causing health hazards. This work investigates whether and how silicon (Si) alleviates As toxicity in wheat. The addition of Si under As-stress significantly improved morphophysiological characteristics, total protein, and membrane stability compared to As-stressed plants, suggesting that Si does have critical roles in As detoxification in wheat. Analysis of arsenate reductase activity and phytosiderophore (PS) release reveals their no involvement in the Si-mediated alleviation of As in wheat. Furthermore, Si supplementation in As-stressed plants showed a significant increase of As in roots but not in shoots compared with the plants grown under As stress. Further, gene expression analysis of two chelating molecules, TaPCS1 (phytochelatin synthase) and TaMT1 (metallothionein synthase) showed significant induction due to Si application under As stress compared with As-stressed plants. It is consistent with the physiological observations and suggests that alleviation of As toxicity in rice might be associated with As sequestration in roots leading to reduced As translocation in shoots. Furthermore, increased catalase, peroxidase, and glutathione reductase activities in roots imply the active involvement of reactive oxygen species scavenging for protecting wheat plants from As-induced oxidative injury. The study provides mechanistic evidence on the beneficial effect of Si on As toxicity in wheat plants.
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| 14. |
- Humayan Kabir, Ahmad, et al.
(författare)
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Nodularia spumigena and Its Attribute to Bloom Formation in the Baltic Sea
- 2012
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Ingår i: Environmental Research, Engineering and Management. - : Kaunas University of Technology. - 1392-1649 .- 2029-2139. ; 1:59, s. 5-9
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Tidskriftsartikel (refereegranskat)abstract
- N. spumigena is a dominant cyanobacterial species found in the Baltic Sea. It forms extensive bloom in late summer in the areas of the Baltic Sea with high phosphorus concentrations and moderate salinity. Both environmental and manmade factors are involved in bloom formation. This review also elucidates the physiological and molecular aspects of nitrogen fixation, heterocyst formation and nodularin production in N. spumigena.
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| 15. |
- Islam, Md Shofikul, et al.
(författare)
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Elevated concentrations of serum matrix metalloproteinase-2 and -9 and their associations with circulating markers of cardiovascular diseases in chronic arsenic-exposed individuals
- 2015
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cardiovascular diseases (CVDs) and cancers are the major causes of chronic arsenic exposure-related morbidity and mortality. Matrix metalloproteinase-2 (MMP-2) and −9 (MMP-9) are deeply involved in the pathogenesis of CVDs and cancers. This study has been designed to evaluate the interactions of arsenic exposure with serum MMP-2 and MMP-9 concentrations especially in relation to the circulating biomarkers of CVDs.Methods: A total of 373 human subjects, 265 from arsenic-endemic and 108 from non-endemic areas in Bangladesh were recruited for this study. Arsenic concentrations in the specimens were measured by inductively coupled plasma mass spectroscopy (ICP-MS) and serum MMPs were quantified by immunoassay kits.Results: Serum MMP-2 and MMP-9 concentrations in arsenic-endemic population were significantly (p < 0.001) higher than those in non-endemic population. Both MMPs showed significant positive interactions with drinking water (rs = 0.208, p < 0.001 for MMP-2; rs = 0.163, p <0.01 for MMP-9), hair (rs= 0.163, p < 0.01 for MMP-2; rs = 0.173, p < 0.01 for MMP-9) and nail (rs= 0.160, p < 0.01 for MMP-2; rs = 0.182, p < 0.001 for MMP-9) arsenic of the study subjects. MMP-2 concentrations were 1.02, 1.03 and 1.05 times, and MMP-9 concentrations were 1.03, 1.06 and 1.07 times greater for 1 unit increase in log-transformed water, hair and nail arsenic concentrations, respectively, after adjusting for covariates (age, sex, BMI, smoking habit and hypertension). Furthermore, both MMPs were increased dose-dependently when the study subjects were split into three (≤10, 10.1-50 and > 50 μg/L) groups based on the regulatory upper limit of water arsenic concentration set by WHO and Bangladesh Government. MMPs were also found to be significantly (p < 0.05) associated with each other. Finally, the concentrations of both MMPs were correlated with several circulating markers related to CVDs.Conclusions: This study showed the significant positive associations and dose–response relationships of arsenic exposure with serum MMP-2 and MMP-9 concentrations. This study also showed the interactions of MMP-2 and MMP-9 concentrations with the circulating markers of CVDs suggesting the MMP-2 and MMP-9 -mediated mechanism of arsenic-induced CVDs.
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| 16. |
- Junnarkar, Manisha, et al.
(författare)
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Probiotic potential of lactic acid bacteria from fresh vegetables : Application in food preservation
- 2019
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Ingår i: Indian Journal of Experimental Biology. - New Delhi, India : National Institute of Science Communication and Information Resources. - 0019-5189 .- 0975-1009. ; 57, s. 825-838
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Tidskriftsartikel (refereegranskat)abstract
- Fresh vegetables are potential source of lactic acid bacteria (LAB). In the present study, LAB were isolated from the fresh vegetables from Pune region. Total 266 LAB were isolated from the edible parts of fresh vegetables viz. cauliflower, gherkins, cluster beans, fenugreek, cow pea, bitter gourd, french beans, tomato, ridged gourd, cucumber and bottle gourd. On phenotypic and molecular characterization predominant genera obtained were Lactobacillus, Enterococcus and Weissella. Twenty one isolates exhibited tolerance to bile salt, acidic pH and pancreatin. Cellular extracts of several isolates with ability to survive in artificial intestinal condition additionally showed antioxidant potential and cell free supernatants xhibited antibacterial potential against selected plant and human pathogens. Bacteriocin and bacteriocin like substances (BLS) substances secreted by these isolates can be used for food preservation.
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| 17. |
- Junnarkara, Manisha V., et al.
(författare)
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Evaluation of Probiotic Potential of Lactic Acid Bacteria Isolated from Different Sources in Western India
- 2018
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Ingår i: Food biotechnology. - United Kingdom : Taylor & Francis. - 0890-5436 .- 1532-4249. ; 32:2, s. 112-129
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Tidskriftsartikel (refereegranskat)abstract
- Lactic acid bacteria isolated from unconventional sources are often attractive targets in the quest for obtaining better probiotics. In the present study, 16 members of the genus Lactobacillus, isolated from 3 different sources in western India, viz., plants, fermented foods and beverages, and human feces, were evaluated for their probiotic and bioactive properties. The isolates were closely related to Lactobacillus fermentum, Lactobacillus pentosus, and mainly Lactobacillus plantarum. The isolates were tolerant to bile salt, acidic pH and pancreatin, although pancreatin tolerance was generally low. Cellular extracts of several isolates displayed antioxidant activity, while cell-free supernatants displayed antibacterial activity against human pathogens. Antioxidant activity of Lactobacilli of human origin was higher than those from vegetables or fermented foods and beverages. L. plantarum AG40V prevented spoilage of fresh-cut fruits, vegetables and sprouted mung-beans. Lactobacilli from all sources displayed equal probiotic potential and those of human origin displayed superior antioxidant activity over others.
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| 18. |
- Kabir, Ahmad H., et al.
(författare)
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Role of Silicon Counteracting Cadmium Toxicity in Alfalfa (Medicago sativa L.)
- 2016
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Ingår i: Frontiers in Plant Science. - : Frontiers Media S.A.. - 1664-462X. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Cadmium (Cd) is one of the most phytotoxic elements causing an agricultural problem and human health hazards. This work investigates whether and how silicon (Si) ameliorates Cd toxicity in Alfalfa. The addition of Si in Cd-stressed plants caused significant improvement in morpho-physiological features as well as total protein and membrane stability, indicating that Si does have critical roles in Cd detoxification in Alfalfa. Furthermore, Si supplementation in Cd stressed plants showed a significant decrease in Cd and Fe concentrations in both roots and shoots compared with Cd-stressed plants, revealing that Si-mediated tolerance to Cd stress is associated with Cd inhibition in Alfalfa. Results also showed no significant changes in the expression of two metal chelators [MsPCS1 (phytochelatin synthase) and MsMT2 (metallothionein)] and PC (phytochelatin) accumulation, indicating that there may be no metal sequestration or change in metal sequestration following Si application under Cd stress in Alfalfa. We further performed a targeted study on the effect of Si on Fe uptake mechanisms. We observed the consistent reduction in Fe reductase activity, expression of Fe-related genes [MsIRT1 (Fe transporter), MsNramp1 (metal transporter) and OsFRO1 (ferric chelate reductase] and Fe chelators (citrate and malate) by Si application to Cd stress in roots of Alfalfa. These results support that limiting Fe uptake through the down-regulation of Fe acquisition mechanisms confers Si-mediated alleviation of Cd toxicity in Alfalfa. Finally, an increase of catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities along with elevated methionine and proline subjected to Si application might play roles, at least in part, to reduce H2O2 and to provide antioxidant defense against Cd stress in Alfalfa. The study shows evidence of the effect of Si on alleviating Cd toxicity in Alfalfa and can be further extended for phytoremediation of Cd toxicity in plants.
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| 19. |
- Karim, Md Rezaul, et al.
(författare)
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Increases in Oxidized Low-Density Lipoprotein and Other Inflammatory and Adhesion Molecules With a Concomitant Decrease in High-Density Lipoprotein in the Individuals Exposed to Arsenic in Bangladesh
- 2013
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Ingår i: Toxicological Sciences. - : Oxford University Press. - 1096-6080 .- 1096-0929. ; 135:1, s. 17-25
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Tidskriftsartikel (refereegranskat)abstract
- Elevated exposure to arsenic has been suggested to be associated with atherosclerosis leading to cardiovascular disease (CVD). However, biochemical events underlying the arsenic-induced atherosclerosis have not yet been fully documented. The aim of this study was to investigate the associations of circulating molecules involved in atherosclerosis with arsenic exposure in the individuals exposed to arsenic in Bangladesh. A total of 324 study subjects, 218 from arsenic-endemic areas and 106 from nonendemic areas in Bangladesh, were recruited. Drinking water, hair, nail, and blood samples were collected from the study subjects for analysis. Total cholesterol (TC), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels were lower in arsenic-endemic subjects than those of nonendemic subjects. Oxidized LDL (Ox-LDL), C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) levels were significantly higher in arsenic-endemic subjects than those in nonendemic subjects. All these circulating molecules showed significant correlations with arsenic exposure (water, hair, and nail arsenic concentrations), and all these relations were significant before and after adjusting for relevant covariates. Among the circulating molecules tested in this study, HDL, Ox-LDL, and CRP showed dose-response relationships with arsenic exposure. Ox-LDL/ HDL ratios were increased with the increasing concentrations of arsenic in the water, hair, and nails. Furthermore, non-HDL cholesterol and TC/ HDL ratios were significantly correlated with arsenic exposure before and after adjusting for relevant covariates. Thus, all the observed associations may be the major features of arsenic exposure-related atherosclerosis leading to CVD.
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| 20. |
- Karim, Sazzad, 1966, et al.
(författare)
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AtPTR3, a wound-induced peptide transporter needed for defence against virulent bacterial pathogens in Arabidopsis
- 2007
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Ingår i: Planta. - : Springer Science and Business Media LLC. - 0032-0935 .- 1432-2048. ; 225, s. 1431-1445
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Tidskriftsartikel (refereegranskat)abstract
- Mutation in the wound-induced peptide transporter gene AtPTR3 (At5g46050) of Arabidopsis thaliana has been shown to affect germination on media containing a high salt concentration. The heterologous expression in yeast was utilized to verify that the AtPTR3 protein transports di-and tripeptides. The T-DNA insert in the Atptr3-1 mutant in the Arabidopsis ecotype C24 revealed two T-DNA copies, the whole vector sequence, and the gus marker gene inserted in the second intron of the AtPTR3 gene. An almost identical insertion site was found in the Atptr3-2 mutant of the Col-0 ecotype. The AtPTR3 expression was shown to be regulated by several signalling compounds, most clearly by salicylic acid (SA), but also methyl jasmonate (MeJA) and abscisic acid. Real-time PCR experiments suggested that the wound-induction of the AtPTR3 gene was abolished in the SA and JA signalling mutants. The Atptr3 mutant plants had increased susceptibility to virulent pathogenic bacteria Erwinia carotovora subsp. carotovora and Pseudomonas syringae pv. tomato, and produced more reactive oxygen species when grown on media containing paraquat or rose bengal. Public microarray data suggest that the AtPTR3 expression was induced by Pseudomonas elicitors and by avirulent P. syringae pathovars and type III secretion mutants. This was verified experimentally for the hrpA mutant with real-time PCR. These results suggest that AtPTR3 is one of the defence-related genes whose expression is reduced by virulent bacterium by type III dependent fashion. Our results suggest that AtPTR3 protects the plant against biotic and abiotic stresses.
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| 21. |
- Karim, Sazzad, et al.
(författare)
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Structural and functional characterization of atPTR3, a stress-induced peptide transporter of Arabidopsis
- 2005
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Ingår i: Journal of Molecular Modeling. - : Springer. - 1610-2940 .- 0948-5023. ; 11:3, s. 226-236
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Tidskriftsartikel (refereegranskat)abstract
- A T-DNA tagged mutant line of Arabidopsis thaliana, produced with a promoter trap vector carrying a promoterless gus (uidA) as a reporter gene, showed GUS induction in response to mechanical wounding. Cloning of the chromosomal DNA flanking the T-DNA revealed that the insert had caused a knockout mutation in a PTR-type peptide transporter gene named At5g46050 in GenBank, here renamed AtPTR3. The gene and the deduced protein were characterized by molecular modelling and bioinformatics. Molecular modelling of the protein with fold recognition identified 12 transmembrane spanning regions and a large loop between the sixth and seventh helices. The structure of AtPTR3 resembled the other PTR-type transporters of plants and transporters in the major facilitator superfamily. Computer analysis of the AtPTR3 promoter suggested its expression in roots, leaves and seeds, complex hormonal regulation and induction by abiotic and biotic stresses. The computer-based hypotheses were tested experimentally by exposing the mutant plants to amino acids and several stress treatments. The AtPTR3 gene was induced by the amino acids histidine, leucine and phenylalanine in cotyledons and lower leaves, whereas a strong induction was obtained in the whole plant upon exposure to salt. Furthermore, the germination frequency of the mutant line was reduced on salt-containing media, suggesting that the AtPTR3 protein is involved in stress tolerance in seeds during germination.
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| 22. |
- Karlsson, Sandra, et al.
(författare)
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Vitamin D and prostate cancer : The role of membrane initiated signaling pathways in prostate cancer progression
- 2010
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Ingår i: Journal of Steroid Biochemistry and Molecular Biology. - : Elsevier. - 0960-0760 .- 1879-1220. ; 121:1-2, s. 413-416
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Tidskriftsartikel (refereegranskat)abstract
- 1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) has been demonstrated to mediate both genomic and non-genomic responses in prostate cancer (CaP) cells. Here, we give an overview of membrane initiated 1,25(OH)2D3 signaling in prostate cancer cell progression. The presence of PDIA3 was investigated and homologous modeling of the putative PDIA3 receptor complex was conducted. Furthermore, the cellular distribution of nVDR was analyzed. We could show that both nVDR and PDIA3 are expressed in the prostate cancer cell lines investigated. The homologous modeling of PDIA3 showed that the receptor complex exists in a trimer formation, which suggests for allosteric activity. Our findings support previous reports and suggest that 1,25(OH)2D3 is an important therapeutic agent in inhibiting prostate cancer progression. Furthermore, our data show that 1,25(OH)2D3 regulate prostate cell biology via multiple pathways and targeting specific pathways for 1,25(OH)2D3 might provide more effective therapies compared to the vitamin D therapies currently clinically tested.
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| 23. |
- Lundh, Dan, et al.
(författare)
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Arsenic accumulation in plants - Outlining strategies for developing improved variety of crops for avoiding arsenic toxicity in foods
- 2010
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Ingår i: Journal of biological systems. - : World Scientific Publishing. - 0218-3390. ; 18:1, s. 223-241
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Tidskriftsartikel (refereegranskat)abstract
- Contamination of food with arsenics is a potential health risk for both humans and animals in many regions of the world, especially in Asia. Arsenics can be accumulated in humans, animals and plants for a longer period and a long-term exposure of humans to arsenics results in severe damage of kidney, lever, heart etc. and many other vascular diseases. Arsenic contamination in human may also lead to development of cancer. In this paper we report our results on data mining approach (an in silico analysis based on searching of the existing genomic databases) for identification and characterization of genes that might be responsible for uptake, accumulation or metabolism of arsenics. For these in silico analyses we have involved the model plant Arabidopsis thaliana in our investigation. By employing a system biology model (a kinetic model) we have studied the molecular mechanisms of these processes in this plant. This model contains equations for uptake, metabolism and sequestration of different types of arsenic; As(V), As(III), MMAA and DMAA. The model was then implemented in the software XPP. The model was also validated against the data existing in the literatures. Based on the results of these in silico studies we have developed some strategies that can be used for reducing arsenic contents in different parts of the plant. Data mining experiments resulted in identification of two candidate genes (ACR2, arsenate reductase 2 and PCS1, phytochelatin synthase 1) that are involved either in uptake, transport or cellular localization of arsenic in A. thaliana. However, our system biology model revealed that by increasing the level of arsenate reductase together with an increased rate of arsenite sequestration in the vacuoles (by involving an arsenite efflux pump MRP1/2), it is possible to reduce the amount of arsenics in the shoots of A. thaliana to 11–12%.
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| 24. |
- Mahfuz, Istiak, et al.
(författare)
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RNA interference and its role in the inhibition and cure of HIV/AIDS
- 2010
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Ingår i: Journal of Life and Earth Science. - : Rajshahi University. - 1990-4827 .- 2408-8641. ; 5, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- The HIV/AIDS epidemic kills about 2.1 million people around the world every year. Unfortunately, until now attempts to control and diminish further spread of the disorder have resulted in very limited success. Although highly active antiretroviral therapy (HAART) is now available as a treatment option, the rate of its success is limited because of drug resistance. In this context, a more efficient treatment is very much necessary to fight with this fatal disease. The RNA interference (RNAi) can be employed as one of the powerful methods for treatment of the disease as it can effectively silence gene expression in a sequence specific manner. The RNAi-mediated treatment is therefore a promising substitution for therapy of the global epidemic HIV/AIDS in the future. The main objective of this review is to focus on an in-depth analysis of RNAi and the principles underlying RNAi treatment, and it's also described the molecular mechanisms of HIV infection, current treatment facilities available to patients as well as therapeutic applications of RNAi along with their limitations as to why the options are inadequate to give a safe and sound cure of HIV/AIDS.
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| 25. |
- Mandal, Abul, et al.
(författare)
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Modeling Arsenic Accumulation in Plants
- 2011
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Ingår i: Proceedings Second International Conference on Emerging Applications of Information Technology. - : IEEE Computer Society. - 9781424496839 - 9780769543291 ; , s. 133-137
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Konferensbidrag (refereegranskat)abstract
- Rice growing regions plagued by arsenic-contaminated soils and irrigation water do not have a viable option for producing arsenic-free crops. For instance, in Bangladesh every year more than 30 million people are affected from rice-derived arsenic contamination that contributes to arsenic levels known to cause health-related illnesses. Our strategy is to genetically-modify molecular mechanisms involved in the localization of arsenic to divert it to the non-edible parts of the plant. To identify viable candidate genes, we employed data mining, an in silico analysis based on searching existing genomic databases and in the genetic model plant Arabidopsis thaliana. To assist our investigation, we constructed a kinetic model to outline strategies for developing genetically-modified plants exhibiting a significant reduction in arsenic concentration in the edible parts (straw and grain). This model contains equations for uptake, metabolism and sequestration of different types of arsenic (As (V), As (III), MMAA and DMAA). The model was implemented using XPP and validated against existing data from the literature. From these analysis, we identified four candidate genes that are involved either in uptake, transport or cellular localization of arsenic in plants. But we found only one gene implicated in arsenic metabolism in rice. In parallel, we identified available T-DNA insertion mutants to determine the effects of these genes on arsenic accumulation. Results obtained from in silico data-mining, kinetic modeling, and assays with T-DNA insertion mutants will be used to design gene cloning experiments to study the target genes in yeast, E. coli and Arabidopsis heterologous systems. Upon confirmation of the effectiveness of these candidates, vectors containing the target genes will be constructed for transformation into rice. The new rice varieties produced will be tested under field conditions to assess their effectiveness at reducing or eliminating arsenic from the edible parts of the rice plant.
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