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Recently, it has been realized that indistinguishability is a resource for quantum information processing. A new method to represent the indistinguishable particles by Franco et al. (Sci Rep 6:20603, 2016, https://doi.org/10.1038/srep20603 ) and measure the concurrence is developed by Nosrati et al. (npj Quantum Inf 6:39, 2020, https://doi.org/10.1038/s41534-020-0271-7 ). The monogamy property says that quantum entanglement cannot be shared freely between more than two particles. For three distinguishable particles, the monogamy of entanglement was first expressed as an inequality using squared concurrence where each particle has a single degree of freedom (for pure or mixed states). Using multiple degrees of freedom, similar inequality was shown to be held between two distinguishable particles. However, for two indistinguishable particles, where each particle cannot be addressed individually, the monogamy inequality was shown to be violated maximally for a specific state. Thus a question naturally arises: what happens to the monogamy of entanglement in the case of three or more indistinguishable particles? We prove that monogamy holds in this scenario and the inequality becomes equality for all pure indistinguishable states. Further, we provide three major operational meanings of our result. Finally, we present an experimental schematic using photons to observe our result.
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Among all the proteins of Periplasmic C type Cytochrome family obtained from cytochrome C7 found in Geobacter sulfurreducens, only the Periplasmic C type Cytochrome A (PPCA) protein can recognize the deoxycholate (DXCA), while its other paralogs do not, as observed from the crystal structures. Though some existing works have used graph-theoretic approaches to realize the 3-D structural properties of proteins, its usage in the rationalisation of the physiochemical behavior of proteins has been very limited. To understand the driving force towards the recognition of DXCA exclusively by PPCA among its paralogs, in this work, we propose two graph theoretic models based on the combinatorial properties, namely, base-pair-type and impact, of the nucleotide bases and the amino acid residues, respectively. Combinatorial analysis of the binding sequences using the proposed base-pair type based graph theoretic model reveals the differential behaviour of PPCA among its other paralogs. Further, to investigate the underlying chemical phenomenon, another graph theoretic model has been developed based on impact. Analysis of the results obtained from impact-based model clearly indicates towards the helix formation of PPCA which is essential for the recognition of DXCA, making PPCA a completely different entity from its paralogs.
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Grupo dos Citocromos c/química , Ácido Desoxicólico/química , Geobacter/química , Modelos Químicos , Proteínas de Bactérias/química , Conformação ProteicaRESUMO
Quantum cycles in established heat engines can be modeled with various quantum systems as working substances. For example, a heat engine can be modeled with an infinite potential well as the working substance to determine the efficiency and work done. However, in this method, the relationship between the quantum observables and the physically measurable parameters-i.e., the efficiency and work done-is not well understood from the quantum mechanics approach. A detailed analysis is needed to link the thermodynamic variables (on which the efficiency and work done depends) with the uncertainty principle for better understanding. Here, we present the connection of the sum uncertainty relation of position and momentum operators with thermodynamic variables in the quantum heat engine model. We are able to determine the upper and lower bounds on the efficiency of the heat engine through the uncertainty relation.
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Various techniques to tackle the black hole information paradox have been proposed. A new way out to tackle the paradox is via the use of a pseudo-density operator. This approach has successfully dealt with the problem with a two-qubit entangle system for a single black hole. In this paper, we present the interaction with a binary black hole system by using an arrangement of the three-qubit system of Greenberger-Horne-Zeilinger (GHZ) state. We show that our results are in excellent agreement with the theoretical value. We have also studied the interaction between the two black holes by considering the correlation between the qubits in the binary black hole system. The results depict a complete agreement with the proposed model. In addition to the verification, we also propose how modern detection of gravitational waves can be used on our optical setup as an input source, thus bridging the gap with the gravitational wave's observational resources in terms of studying black hole properties with respect to quantum information and entanglement.
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Established heat engines in quantum regime can be modeled with various quantum systems as working substances. For example, in the non-relativistic case, we can model the heat engine using infinite potential well as a working substance to evaluate the efficiency and work done of the engine. Here, we propose quantum heat engine with a relativistic particle confined in the one-dimensional potential well as working substance. The cycle comprises of two isothermal processes and two potential well processes of equal width, which forms the quantum counterpart of the known isochoric process in classical nature. For a concrete interpretation about the relation between the quantum observables with the physically measurable parameters (like the efficiency and work done), we develop a link between the thermodynamic variables and the uncertainty relation. We have used this model to explore the work extraction and the efficiency of the heat engine for a relativistic case from the standpoint of uncertainty relation, where the incompatible observables are the position and the momentum operators. We are able to determine the bounds (the upper and the lower bounds) of the efficiency of the heat engine through the thermal uncertainty relation.
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Humans are often exposed to bisphenol A (BPA), the monomer of polycarbonate plastics and epoxy resins, through BPA contaminated drinking water, beverages and foods, packaged in polycarbonate plastic bottles and cans coated with epoxy resins due to leaching. Several research groups have reported that BPA may cause damage of mitochondria in liver, kidney, heart and brain cells by inducing oxidative stress. The antioxidant efficacy of gallic acid (GA), a polyphenol compound obtained from plants, against different toxicants induced oxidative stress has been well established. The aim of the present study was to examine the protective efficacy of GA against BPA induced oxidative damages of the rat liver mitochondria ex vivo. In our study, we have found a significant decrease in the intactness of mitochondria; a significant increase (Pâ¯≤â¯0.001) in the levels of lipid peroxidation end product (i.e. malondialdehyde) and protein carbonylation product; and also a significant decrease (Pâ¯≤â¯0.001) in the reduced glutathione content; when mitochondria were incubated with BPA (160 µM/ml) only. These results indicate that BPA probably causes damage to the cellular macromolecules through oxidative stress. We have observed significant counteractions (Pâ¯≤â¯0.001) against BPA induced alterations in mitochondrial intactness, lipid peroxidation and protein carbonylation products formation and reduced glutathione content when mitochondria were incubated with BPA and GA (20⯵g/ml/ 40⯵g/ml/ 80⯵g/ml) in combination in a dose-dependent manner. Gallic acid also showed significant restorations (Pâ¯≤â¯0.001) of the activities of antioxidant enzymes, Krebs cycle enzymes, respiratory chain enzymes and thiolase when mitochondria were incubated with BPA and dosage of GA (20⯵g/ml/ 40⯵g/ml/ 80⯵g/ml) in combination compared to BPA incubated mitochondria. Furthermore, GA significantly (Pâ¯≤â¯0.001) counteracted the BPA induced decrease in tryptophan and NADH auto-fluroscence levels in mitochondria. This result suggests that GA protects the mitochondria probably by reducing the oxidative stress. Besides, GA protects the mitochondrial surface from BPA induced oxidative damages as viewed under the scanning electron microscope. Considering all the results, it can be concluded that GA shows potent efficacy in protecting the rat liver mitochondria ex vivo from BPA induced oxidative stress mediated damages.
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The aim of the study was to examine the toxic effects of Monosodium glutamate (MSG), an extensively used food additive, on the contraction of uterine visceral smooth muscle (UVSM) in rat and to elucidate the probable neurocrine mechanism involved in it. MSG produced significant potentiation of the force and inhibition of frequency of uterus recorded ex vivo in chronic MSG exposure and in single dose acute experiments. MSG also produced significant potentiation of force of acetylcholine induced contraction and no alterations in atropine induced contraction of uterus. Further, MSG produced significant increase in force and frequency of contraction of neostigmine incubated uterus. We have found significant potentiation of the post pause force of contraction of uterus when MSG was applied in adrenaline incubated uterus. MSG also produced significant decrease in frequency of contraction of sodium nitroprusside incubated uterus; increase in frequency of N-ω-Nitro-l-Arginine Methyl Ester incubated uterus and no significant changes in frequency of contraction of methylene blue incubated uterus. These results indicate that MSG potentiates the force of contraction of UVSM predominantly by augmenting the activity of cholinergic intrinsic efferents and inhibits the frequency of contraction probably by augmenting the activity of nitrergic efferents. In conclusion, MSG potentiates the force and inhibits the frequency of contraction of UVSM, and the MSG induced effect is probably mediated through the augmentation of acetylcholine and nitric oxide signaling pathways.
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Acetilcolina/agonistas , Aromatizantes/efeitos adversos , Miométrio/fisiologia , Óxido Nítrico/agonistas , Sistemas do Segundo Mensageiro , Glutamato de Sódio/efeitos adversos , Contração Uterina , Acetilcolina/antagonistas & inibidores , Acetilcolina/metabolismo , Agonistas Adrenérgicos/farmacologia , Animais , Inibidores da Colinesterase/farmacologia , Inibidores Enzimáticos/farmacologia , Feminino , Antagonistas Muscarínicos/farmacologia , Miométrio/efeitos dos fármacos , Miométrio/inervação , Neurônios Nitrérgicos/efeitos dos fármacos , Neurônios Nitrérgicos/fisiologia , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Distribuição Aleatória , Ratos , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Contração Uterina/efeitos dos fármacosRESUMO
There is an exigency of transformation of the enormous amount of biological data available in various forms into some significant knowledge. We have tried to implement Machine Learning (ML) algorithm models on the protein-ligand binding affinity data already available to predict the binding affinity of the unknown. ML methods are appreciably faster and cheaper as compared to traditional experimental methods or computational scoring approaches. The prerequisites of this prediction are sufficient and unbiased features of training data and a prediction model which can fit the data well. In our study, we have applied Random forest and Gaussian process regression algorithms from the Weka package on protein-ligand binding affinity, which encompasses protein and ligand binding information from PdbBind database. The models are trained on the basis of selective fundamental information of both proteins and ligand, which can be effortlessly fetched from online databases or can be calculated with the availability of structure. The assessment of the models was made on the basis of correlation coefficient (R 2) and root mean square error (RMSE). The Random forest model gave R 2 and RMSE of 0.76 and 1.31 respectively. We have also used our features and prediction models on the dataset used by others and found that our model with our features outperformed the existing ones.
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The aim of the present study was to examine the effect of monosodium glutamate (MSG) on the functions of ovary and uterus in rat. Virgin female rats of Charles Foster strain (120 gms approximately) were administrated MSG by oral gavage at a dose level of 0.8, 1.6, 2.4 gm/kgBW/day, respectively for 30 and 40 days duration. We observed a significant decrease in the duration of proestrus, estrus and metestrus phases, and increase in the duration of diestrus phase and diestrus index compared to control. We found significant increase in the levels of serum LH, FSH and estradiol in test groups of rat. We also observed significant increase in the number of primary and primordial follicles, increase in the size of graafian follicle, and decrease in the size of corpus luteum. Further, we have seen significant increase in the activities SOD, CAT and GST, decrease in the activities GR and GPx, and decrease MDA level in MSG exposed groups. These results suggest that MSG impairs the functions of the ovary probably by augmenting the release of FSH, LH and estradiol; promoting the follicular maturation and improving the biochemical mechanism for antioxidant defense. We also observed significant potentiation of the force of contraction of uterus in estrus, metestrus and diestrus phases. This result suggests that MSG potentiates the contraction of uterus probably by stimulating the estradiol sensitivity to oxytocin. From the results it is concluded that MSG suppresses the female reproductive function in rat probably by impairing the functions of ovary and uterus.
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Ovário/efeitos dos fármacos , Glutamato de Sódio/toxicidade , Útero/efeitos dos fármacos , Animais , Catalase/metabolismo , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Glutationa Transferase/metabolismo , Hormônio Luteinizante/sangue , Malondialdeído/metabolismo , Contração Muscular/efeitos dos fármacos , Folículo Ovariano/efeitos dos fármacos , Ovário/metabolismo , Ovário/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Superóxido Dismutase/metabolismo , Útero/metabolismo , Útero/patologiaRESUMO
Sarcoma 180 (S-180) tumour cell line is a stable murine tumour cell line with 98-99% stumour takes capacity in Swiss albino mouse - Mus musculus. 2 Methoxyestradiol (2ME) - a promising anti-neoplastic and anti-angiogenic agent, showed toxicity to host body in higher concentration. Cyclophosphamide (CP), the anti-neoplastic agent has long been used as a chemotherapeutic drug for treatment of different cancers. Our studies have shown that the combination effect of 2ME and CP on S-180 tumour cell line is anti-proliferative and less toxic. The treatment with lower concentrations of 2ME and CP (6.5 mg 2ME/kg body weight + 75 mg CP/kg body weight) antagonistically increased the life span of tumour bearing mice and synergistically inhibited the viable cell population. 2ME or CP treatment individually induces G2/M arrest. The combination treatment of 2ME + CP (6.5 mg 2ME/kg body weight + 75 mg CP/kg body weight) produced a significant increase of cells in the G0 which is the indication of cell arrest or apoptosis. Reduction of cell viability by 2ME + CP treatments is due to apoptotic cell death. This combination therapy produced a significant inhibitory effect of cell proliferation and augmentation of cell accumulation in the G0 phase (i.e. apoptosis). Apoptosis is validated by Fluorescence staining of control and treated S-180 tumour cells with Acridine Orange and EtBr dye. Moreover, a steady increase in the frequency of complex chromosomal aberrations (i.e. tri-, qudri-radial translocations) in tumour cells was noted in that particular concentration of combination therapy treated series along with the increase in dead cell frequency and tumour regression pattern. It is assumed that, these chromosomal abnormalities or damages recorded in higher frequency prevent the affected metaphases to enter into the next cell cycle through apoptosis or necrosis. This study introduces a novel combination, where this particular concentration of 2ME + CP (i.e. 6.5 mg 2ME/kg body weight + 75 mg CP/kg body weight) not only enhanced the life span of tumour bearing mouse and decreased the tumour volume antagonistically but also inhibited the viable cell population synergistically, which could serve as a potential effective regimen for cancer treatment.
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Nickel is a potential neurotoxic pollutant inflicting damage in living organisms, including fish, mainly through oxidative stress. Previous studies have demonstrated the impact of nickel toxicity on mitochondrial function, but there remain lacunae on the damage inflicted at mitochondrial respiratory level. Deficient mitochondrial function usually affects the activities of important adenosinetriphosphatases responsible for the maintenance of normal neuronal function, namely Na+K+ATPase, as explored in our study. Previous reports demonstrated the dysfunction of this enzyme upon nickel exposure but the contributing factors for the inhibition of this enzyme remained unexplored. The main purpose of this study was to elucidate the impact of nickel neurotoxicity on mitochondrial respiratory complexes and Na+K+ATPase in the piscine brain and to determine the contributing factors that had an impact on the same. Adult Clarias batrachus were exposed to nickel treated water at 10% and 20% of the 96 h LC50 value (41 mg.l-1) respectively and sampled on 20, 40 and 60 days. Exposure of fish brain to nickel led to partial inhibition of complex IV of mitochondrial respiratory chain, however, the activities of complex I, II and III remained unaltered. This partial inhibition of mitochondrial respiratory chain might have been sufficient to lower mitochondrial energy production in mitochondria that contributed to the partial dysfunction of Na+K+ATPase. Besides energy depletion other contributing factors were involved in the dysfunction of this enzyme, like loss of thiol groups for enzyme activity and lipid peroxidation-derived end products that might have induced conformational and functional changes. However, providing direct evidence for such conformational and functional changes of Na+K+ATPase was beyond the scope of the present study. In addition, immunoblotting results also showed a decrease in Na+K+ATPase protein expression highlighting the impact of nickel neurotoxicity on the expression of the enzyme itself. The implication of the inhibition of mitochondrial respiration and Na+K+ATPase dysfunction was the neuronal death as evidenced by enhanced caspase-3 and caspase-9 activities. Thus, this study established the deleterious impact of nickel neurotoxicity on mitochondrial functions in the piscine brain and identified probable contributing factors that can act concurrently in the inhibition of Na+K+ATPase. This study also provided a vital clue about the specific areas that the therapeutic agents should target to counter nickel neurotoxicity.
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Bisphenol S (BPS) is an industrial chemical which is recently used to replace the potentially toxic Bisphenol A (BPA) in making polycarbonate plastics, epoxy resins and thermal receipt papers. The probable toxic effects of BPS on the functions of haemopoietic and cardiovascular systems have not been reported till to date. We report here that BPS depresses haematological functions and induces cardiovascular risks in rat. Adult male albino rats of Sprague-Dawley strain were given BPS at a dose level of 30, 60 and 120 mg/kg BW/day respectively for 30 days. Red blood cell (RBC) count, white blood cell (WBC) count, Hb concentration, and clotting time have been shown to be significantly (*P < 0.05) reduced in a dose dependent manner in all exposed groups of rats comparing to the control. It has also been shown that BPS increases total serum glucose and protein concentration in the exposed groups of rats. We have observed that BPS increases serum total cholesterol, triglyceride, glycerol free triglyceride, low density lipoprotein (LDL) and very low density lipoprotein (VLDL) concentration, whereas high density lipoprotein (HDL) concentration has been found to be reduced in the exposed groups. BPS significantly increases serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities dose dependently. Moreover, serum calcium, bilirubin and urea concentration have been observed to be increased in all exposed groups. In conclusion, BPS probably impairs the functions of blood and promotes cardiovascular risks in rats.
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Lead (Pb) is one of the most pollutant metals that accumulate in the brain mitochondria disrupting mitochondrial structure and function. Though oxidative stress mediated by reactive oxygen species remains the most accepted mechanism of Pb neurotoxicity, some reports suggest the involvement of nitric oxide (â¢NO) and reactive nitrogen species in Pb-induced neurotoxicity. But the impact of Pb neurotoxicity on mitochondrial respiratory enzyme complexes remains unknown with no relevant report highlighting the involvement of peroxynitrite (ONOO-) in it. Herein, we investigated these effects in in vivo rat model by oral application of MitoQ, a known mitochondria-specific antioxidant with ONOO- scavenging activity. Interestingly, MitoQ efficiently alleviated ONOO--mediated mitochondrial complexes II, III and IV inhibition, increased mitochondrial ATP production and restored mitochondrial membrane potential. MitoQ lowered enhanced caspases 3 and 9 activities upon Pb exposure and also suppressed synaptosomal lipid peroxidation and protein oxidation accompanied by diminution of nitrite production and protein-bound 3-nitrotyrosine. To ascertain our in vivo findings on mitochondrial dysfunction, we carried out similar experiments in the presence of different antioxidants and free radical scavengers in the in vitro SHSY5Y cell line model. MitoQ provided better protection compared to mercaptoethylguanidine, N-nitro-L-arginine methyl ester and superoxide dismutase suggesting the predominant involvement of ONOO- compared to â¢NO and O2â¢-. However, dimethylsulphoxide and catalase failed to provide protection signifying the noninvolvement of â¢OH and H2O2 in the process. The better protection provided by MitoQ in SHSY5Y cells can be attributed to the fact that MitoQ targets mitochondria whereas mercaptoethylguanidine, N-nitro-L-arginine methyl ester and superoxide dismutase are known to target mainly cytoplasm and not mitochondria. Taken together the results from the present study clearly brings out the potential of MitoQ against ONOO--induced toxicity upon Pb exposure indicating its therapeutic potential in metal toxicity.
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Encéfalo/efeitos dos fármacos , Chumbo/toxicidade , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Compostos Organofosforados/farmacologia , Ácido Peroxinitroso/efeitos adversos , Ubiquinona/análogos & derivados , Animais , Antioxidantes/farmacologia , Encéfalo/metabolismo , Morte Celular , Células Cultivadas , Feminino , Humanos , Mediadores da Inflamação/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Mitocôndrias/metabolismo , Ratos , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo , Ubiquinona/farmacologiaRESUMO
Metanil yellow (MY) is a most frequently used food color in West Bengal, India. The toxic effects of MY on the male reproductive system have been reported discriminately in animal models. The probable toxic effects of MY on female reproductive functions have not been reported till date. Therefore, this study was designed to examine the effect of MY on estrous cycle rhythmicity and ovarian folliculogenesis in female rats. Rats have been exposed to MY at three doses of 250, 500, 750 mg kgBW-1 day-1 for two exposure durations, 20 and 30 days. We observed significant changes in the number and duration of estrous cycle along with prominent cytoarchitectural changes in the cellular characteristics of vaginal smear of component phases of estrous cycle in a dose and duration-dependent manner in MY-treated rats compared to control rats. We also observed a significant decrease in serum follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol levels in MY-treated rats. Further, the activities of some antioxidants enzymes in brain tissues of MY-treated rats were significantly decreased and the level of malondialdehyde (MDA), a marker of lipid peroxidation, in brain tissues of MY-treated rats was also significantly increased. The ovarian folliculogenesis in this study was also significantly impaired in MY-treated rats. In conclusion, MY impairs the estrous cycle and ovarian folliculogenesis in female rats by inhibiting the secretion of FSH and estradiol from the ovary, and inducing the oxidative stress in hypothalamic-pituitary-gonadal axis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 2057-2067, 2016.
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Compostos Azo/toxicidade , Ciclo Estral/efeitos dos fármacos , Corantes de Alimentos/toxicidade , Folículo Ovariano/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Estradiol/sangue , Ciclo Estral/fisiologia , Feminino , Hormônio Foliculoestimulante/sangue , Peroxidação de Lipídeos/efeitos dos fármacos , Hormônio Luteinizante/sangue , Folículo Ovariano/citologia , Estresse Oxidativo/efeitos dos fármacos , Periodicidade , RatosRESUMO
The gastrointestinal tract is directly exposed to bisphenol A (BPA)-tainted foods and beverages stored in polycarbonate plastic containers. The effect of BPA on the movement of small intestine has not been reported until now. We report here the effect of BPA on the movement of the duodenum ex vivo in a rat model. We found significant inhibition of duodenal movement by BPA (10-320 µM). We suggest that BPA-induced inhibition of duodenal movement might be due to the suppression of stimulatory and/or activation of inhibitory motor neurons in enteric plexuses innervating the longitudinal and circular visceral smooth muscle cells in the duodenal wall. We observed a significant reversal of BPA-induced depression of duodenal movement by methylene blue, a soluble guanylyl cyclase blocker and N-ω-nitro-L-arginine methyl ester, a nitric oxide (NO) synthase inhibitor; but significant potentiation of the movement by sodium nitroprusside, a NO donor. From the results, we may suggest that BPA-induced inhibition of the movement might be partially due to activation of inhibitory motor neurons that secrete NO, a relaxant, on to smooth muscle cells. Furthermore, we found significant reversal of BPA-induced depression of the movement in phentolamine, an α-adrenergic receptor blocker, pretreated preparation. This result proves that norepinephrine secreting motor neurons may also be involved in BPA-induced inhibition of the movement. From the results, we conclude that BPA inhibits the movement of the duodenum through NO-mediated soluble guanylyl cyclase and α-adrenergic signaling pathways in visceral smooth muscle cells.
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Compostos Benzidrílicos/toxicidade , Duodeno/efeitos dos fármacos , Guanilato Ciclase/fisiologia , Óxido Nítrico/fisiologia , Fenóis/toxicidade , Receptores Adrenérgicos alfa/fisiologia , Receptores Citoplasmáticos e Nucleares/fisiologia , Transdução de Sinais/efeitos dos fármacos , Acetatos/farmacologia , Animais , Cloretos/farmacologia , Duodeno/fisiologia , Azul de Metileno/farmacologia , Contração Muscular/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Nitroprussiato/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , Guanilil Ciclase SolúvelRESUMO
The present invivo study was designed to elucidate the toxic effect of lead on oxidative stress, Na(+)K(+)ATPase and mitochondrial electron transport chain activity of the brain of Clarias batrachus. The fish were exposed to 10 and 20% of the derived 96 h LC(50) value, 37.8 and 75.6 mg L(-1), respectively, and sampled on 20, 40 and 60 days. Exposure of fish brain to lead demonstrated an increased production of reactive oxygen species, increased lipid peroxidation, loss of protein thiol groups in synaptosomal fraction with the decreased activity of Na(+)K(+)ATPase, partial inactivation of mitochondrial electron transport chain activity and energy depletion. However, no change in protein carbonyl content in synaptosomal fraction was observed due to lead exposure. Concluding the results of our investigation we suggest that lead exposure induces oxidative stress in the brain of Clarias batrachus and the decline in Na(+)K(+)ATPase activity was presumeably mediated by the combined action of lipid peroxidation and deficient mitochondrial electron transport chain activity.
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Encéfalo/efeitos dos fármacos , Peixes-Gato/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Chumbo/toxicidade , Estresse Oxidativo/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Encéfalo/enzimologia , Encéfalo/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/enzimologia , Sinaptossomos/metabolismo , Testes de ToxicidadeRESUMO
The present study aimed at ergonomic evaluation of the prevalence of work-related musculoskeletal disorders among construction labourers working in unorganized sectors in West Bengal, India. A modified Nordic questionnaire was applied to one hundred forty male and ninety female construction labourers to acquire information about musculoskeletal symptoms like pain in different body parts. Work-rest schedules of the labourers in different work activities were studied. Working postures were analyzed by means of the Rapid Entire Body Assessment (REBA) tool. Body part discomfort (BPD) scale was used to assess the intensity of feeling of discomforts in the different body parts. It was revealed that the labourers performed repetitive, stressful work for a long period of time in a single work-rest cycle and the load lifted and carried by them were more than the NIOSH recommended weight limit. The analyses of working postures revealed that most of their working postures were unsafe and ranked under REBA action level 3 and 4. The results obtained by applying the Nordic questionnaire and BPD scale revealed that the prevalence of pain in various regions of the body, especially low-back pain, was alarmingly high in both male and female labourers. Training for safe lifting of materials, proper work-rest schedule, modifications of some working procedures and the use of ergonomically designed equipment may certainly reduce the work-related musculoskeletal disorders and improve the health status of construction labourers working in unorganized sectors.