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Environmental Science and Pollution... Aug 2018Due to the importance of pollution monitoring in marine ecosystems and lack of a coherent and systematic investigation of heavy metal ions along the southern shores of...
Due to the importance of pollution monitoring in marine ecosystems and lack of a coherent and systematic investigation of heavy metal ions along the southern shores of the Caspian Sea, in the present study, the amount of these metals and As ions in coastal waters along its 780-km-long coast in Iran have been studied. Heavy metals (cobalt, nickel, copper, zinc, cadmium, mercury, lead) and a poisonous metalloid (arsenic) were selected in 59 sampling stations and determined using differential pulse polarography method. The multivariate statistical tools were applied to describe and interpret the experimental data. The overall mean concentrations of studied metals (in microgram per liter; μg L) in the samples were found in the order Zn (10.9) > Ni (7.4) > Cu (5.5) > Pb (1.9) > Hg (1.4) > As (1.3) > Co (1.1) > Cd (0.2). The results when compared with reported international standards confirmed that the sampled waters do contain some of these elements above the suggested maximum permissible limits. Hg and Cu were detected in 54.2 and 72.9% of the samples, almost all above the permissible limits. Ni, Zn, Pb, and Co were detected in 100, 96.6, 93.2, and 88.1%, respectively, while 8.5, 22.0, 3.4, and 1.7% were above the permissible limits. Cd and As were present in 61 and 93% of the samples, and their concentrations were higher than the rate presented by Russian System of Management Chemicals (RSMC). In addition, spatial distribution of heavy metal concentrations showed that Gorgan Bay is an ecosystem serving as a filter, trapping natural and anthropogenic materials that are brought from industrial, commercial, and urbanized areas. The multivariate data analysis reveals that Caspian Sea is contaminated by both anthropogenic as well as pedo-geochemical sources.
Topics: Arsenic; Environmental Monitoring; Iran; Metals, Heavy; Oceans and Seas; Seawater; Water Pollutants, Chemical
PubMed: 29876847
DOI: 10.1007/s11356-018-2455-7 -
Acta Crystallographica. Section E,... Dec 2016The lattice of 5,7,12,14-tetra-hydro-5,14:7,12-bis-([1,2]benzeno)-penta-cene-6,13-dione, CHO, at 173 K has triclinic (-1) symmetry and crystallizes with four...
The lattice of 5,7,12,14-tetra-hydro-5,14:7,12-bis-([1,2]benzeno)-penta-cene-6,13-dione, CHO, at 173 K has triclinic (-1) symmetry and crystallizes with four independent half-mol-ecules in the asymmetric unit. Each mol-ecule is generated from a CHO substructure through an inversion center at the centroid of the central quinone ring, generating a wide H-shaped mol-ecule, with a dihedral angle between the mean planes of the terminal benzene rings in each of the two symmetry-related pairs over the four mol-ecules of 68.6 (1) (), 65.5 (4) (), 62.3 (9) (), and 65.8 (8)° (), an average of 65.6 (1)°. This compound has applications in gas-separation membranes constructed from polymers of intrinsic microporosity (PIM). The title compound is a product of a double Diels-Alder reaction between anthracene and -benzo-quinone followed by de-hydrogenation. It has also been characterized by cyclic voltammetry and rotating disc electrode polarography, FT-IR, high resolution mass spectrometry, elemental analysis, and H NMR.
PubMed: 27980819
DOI: 10.1107/S2056989016017461 -
International Journal of Analytical... 2021This review article represents the collection and discussion of various analytical methods available in the literature for the determination of allopurinol (ALLP) in... (Review)
Review
This review article represents the collection and discussion of various analytical methods available in the literature for the determination of allopurinol (ALLP) in pharmaceutical and biological samples consisting of HPLC, UV-visible method, near-IR spectroscopy, spectrofluorometry, capillary electrophoresis, polarography, voltammetry, and hyphenated techniques such as LC-MS, LC-MS/MS, UPLC-MS/MS, and GC-MS. The anticipated review provides details about the comparative utilization of various analytical techniques for the determination of ALLP. The present review article can be effectively explored to conduct future analytical investigation for the estimation of ALLP.
PubMed: 34194505
DOI: 10.1155/2021/5558651 -
Biochimica Et Biophysica Acta. Proteins... Dec 2017Hemocyanins have highly conserved copper-containing active sites that bind oxygen. However, structural differences among the hemocyanins of various mollusks may affect...
Hemocyanins have highly conserved copper-containing active sites that bind oxygen. However, structural differences among the hemocyanins of various mollusks may affect their physicochemical properties. Here, we studied the oxygen-binding cooperativity and affinity of Concholepas concholepas hemocyanin (CCH) and its two isolated subunits over a wide range of temperatures and pH values. Considering the differences in the quaternary structures of CCH and keyhole limpet hemocyanin (KLH), we hypothesized that the heterodidecameric CCH has different oxygen-binding parameters than the homodidecameric KLH. A novel modification of the polarographic method was applied in which rat liver submitochondrial particles containing cytochrome c oxidase were introduced to totally deplete oxygen of the test solution using ascorbate as the electron donor. This method was both sensitive and reproducible. The results showed that CCH, like other hemocyanins, exhibits cooperativity, showing an inverse relationship between the oxygen-binding parameters and temperature. According to their Hill coefficients, KLH has greater cooperativity than CCH at physiological pH; however, CCH is less sensitive to pH changes than KLH. Appreciable differences in binding behavior were found between the CCH subunits: the cooperativity of CCH-A was not only almost double that of CCH-B, but it was also slightly superior to that of CCH, thus suggesting that the oxygen-binding domains of the CCH subunits are different in their primary structure. Collectively, these data suggest that CCH-A is the main oxygen-binding domain in CCH; CCH-B may play a more structural role, perhaps utilizing its surprising predisposition to form tubular polymers, unlike CCH-A, as demonstrated here using electron microscopy.
Topics: Animals; Hemocyanins; Hydrogen-Ion Concentration; Mollusca; Oxygen; Protein Domains; Protein Subunits
PubMed: 28844742
DOI: 10.1016/j.bbapap.2017.08.017 -
Acta Neuropsychiatrica Apr 2021The present study was designed to test the hypothesis that there is a reduction in the activity of the enzyme cytochrome c oxidase (Cox) in Alzheimer's disease (AD). (Comparative Study)
Comparative Study Meta-Analysis
OBJECTIVE
The present study was designed to test the hypothesis that there is a reduction in the activity of the enzyme cytochrome c oxidase (Cox) in Alzheimer's disease (AD).
METHODS
Systematic review of literature and meta-analysis were used with data obtained from the PubMed, Scopus, MEDLINE, Lilacs, Eric and Cochrane. The keywords were Alzheimer's AND Cox AND mitochondria; Alzheimer's AND Cox AND mitochondria; Alzheimer's AND complex IV AND mitochondria. A total of 1372 articles were found, 23 of them fitting the inclusion criteria. The data were assembled in an Excel spreadsheet and analysed using the RevMan software. A random effects model was adopted to the estimative of the effect.
RESULTS
The data shows a significant decrease in the activity of the Cox AD patients and animal models.
CONCLUSION
Cox enzyme may be an important molecular component involved in the mechanisms underlying AD. Therefore, this enzyme may represent a possible new biomarker for the disease as a complementary diagnosis and a new treatment target for AD.
Topics: Alzheimer Disease; Animals; Colorimetry; Electron Transport Complex IV; Humans; Mice; Mitochondria; Models, Animal; Polarography; Rats; Software; Spectrophotometry
PubMed: 33256871
DOI: 10.1017/neu.2020.43 -
International Journal of Molecular... Mar 2024Endometriosis is one of the leading pathologies of the reproductive system of women of fertile age, which shows changes in cell metabolism in the lesions. We conducted a...
Endometriosis is one of the leading pathologies of the reproductive system of women of fertile age, which shows changes in cell metabolism in the lesions. We conducted a study of the cellular respiration according to the polarography and the mRNA content of the main metabolic proteins using qRT-PCR of intraoperative endometrial biopsies from patients in the control group and with different localizations of endometriosis (adenomyosis, endometrioma, pelvic peritoneum). In biopsy samples of patients with endometriomas and pelvic peritoneum endometriotic lesions, the rate of oxygen absorption was significantly reduced, and, moreover, in the extragenital case, there was a shift to succinate utilization. The mRNA content of the cytochrome c, cytochrome c oxidase, and ATP synthase was also reduced, but hexokinase HK2 as well as pyruvate kinase were significantly higher than in the control. These oxidative phosphorylation and gene expression profiles suggest the Warburg effect and a shift in metabolism toward glycolysis. For adenomyosis, on the contrary, cellular respiration was significantly higher than in the control group due to the terminal region of the respiratory chain, ATP synthase, and its mRNA was increased as well. These data allow us to suggest that the therapeutic strategies of endometriosis based on modulation energy metabolism should take lesion localization into account.
Topics: Humans; Female; Endometriosis; Adenomyosis; Cell Respiration; Biopsy; RNA, Messenger; Adenosine Triphosphate
PubMed: 38612490
DOI: 10.3390/ijms25073680 -
Journal of Pharmaceutical and... Oct 2016Polarography was the first developed automated method of voltage-controlled electrolysis with dropping mercury electrode (DME). Then, hanging mercury drop and static... (Review)
Review
Polarography was the first developed automated method of voltage-controlled electrolysis with dropping mercury electrode (DME). Then, hanging mercury drop and static mercury drop electrodes were added as an alternative indicator electrode. In this way, polarography turned formally into voltammetry with mercury electrodes in the electroreduction way. Solid electrodes such as noble metal and carbon based electrodes can be used for the investigation of the compounds for both oxidation and reduction directions, which is called voltammetry. The voltammetric and polarographic techniques are more sensitive, reproducible, and easily used electroanalytical methods that can be alternative to more frequently used separation and spectrometric methods. Furthermore, in some cases there is a relationship between voltammetry and pharmaceutical samples, and the knowledge of the mechanism of their electrode reactions can give a useful clue in elucidation of the mechanism of their interaction with living cells. The voltammetric and polarographic analysis of drugs in pharmaceutical preparations are by far the most common use of electrochemistry for analytical pharmaceutical problems. Recent trends and challenges in the electrochemical methods for the detection of DNA hybridization and pathogens are available. Low cost, small sample requirement and possibility of miniaturization justifies their increasing development.
Topics: Electrochemical Techniques; Forecasting; Ion-Selective Electrodes; Mercury; Nanostructures; Nanotechnology; Pharmaceutical Preparations
PubMed: 27210510
DOI: 10.1016/j.jpba.2016.05.006 -
International Journal of Molecular... Jul 2020For deep space exploration, reproductive health must be maintained to preserve the species. However, the mechanisms underlying the effect of changes in gravity on male...
For deep space exploration, reproductive health must be maintained to preserve the species. However, the mechanisms underlying the effect of changes in gravity on male germ cells remain poorly understood. The aim of this study was to determine the effect of simulated micro- and hypergravity on mouse sperm motility and the mechanisms of this change. For 1, 3 and 6 h, mouse sperm samples isolated from the caudal epididymis were subjected to simulated microgravity using a random position machine and 2g hypergravity using a centrifuge. The experimental samples were compared with static and dynamic controls. The sperm motility and the percentage of motile sperm were determined using microscopy and video analysis, cell respiration was determined by polarography, the protein content was assessed by Western blotting and the mRNA levels were determined using qRT-PCR. The results indicated that hypergravity conditions led to more significant changes than simulated microgravity conditions: after 1 h, the speed of sperm movement decreased, and after 3 h, the number of motile cells began to decrease. Under the microgravity model, the speed of movement did not change, but the motile spermatozoa decreased after 6 h of exposure. These changes are likely associated with a change in the structure of the microtubule cytoskeleton, and changes in the energy supply are an adaptive reaction to changes in sperm motility.
Topics: Animals; Cell Respiration; Cells, Cultured; Hypergravity; Male; Mice; Proteins; RNA, Messenger; Sperm Motility; Spermatozoa; Weightlessness; Weightlessness Simulation
PubMed: 32709012
DOI: 10.3390/ijms21145054 -
Structural Dynamics (Melville, N.Y.) Mar 2019Time-resolved crystallography is a powerful technique to elucidate molecular mechanisms at both spatial (angstroms) and temporal (picoseconds to seconds) resolutions. We...
Time-resolved crystallography is a powerful technique to elucidate molecular mechanisms at both spatial (angstroms) and temporal (picoseconds to seconds) resolutions. We recently discovered an unusually slow reaction at room temperature that occurs on the order of days: the reverse oxidative decay of the chemically labile (6S)-5,6,7,8-tetrahydrofolate in complex with its producing enzyme dihydrofolate reductase. Here, we report the critical analysis of a representative dataset at an intermediate reaction time point. A quinonoid-like intermediate state lying between tetrahydrofolate and dihydrofolate features a near coplanar geometry of the bicyclic pterin moiety, and a tetrahedral C6 geometry is proposed based on the apparent mFo-DFc omit electron densities of the ligand. The presence of this intermediate is strongly supported by Bayesian difference refinement. Isomorphous Fo-Fo difference map and multi-state refinement analyses suggest the presence of end-state ligand populations as well, although the putative intermediate state is likely the most populated. A similar quinonoid intermediate previously proposed to transiently exist during the oxidation of tetrahydrofolate was confirmed by polarography and UV-vis spectroscopy to be relatively stable in the oxidation of its close analog tetrahydropterin. We postulate that the constraints on the ligand imposed by the interactions with the protein environment might be the origin of the slow reaction observed by time-resolved crystallography.
PubMed: 30868089
DOI: 10.1063/1.5086436 -
Antioxidants (Basel, Switzerland) Dec 2022Redox disbalance in placental cells leads to the hyperproduction of reactive oxygen species (ROS), it mediates the dysregulation of the maternal immune tolerance to a...
Interrelation between miRNAs Expression Associated with Redox State Fluctuations, Immune and Inflammatory Response Activation, and Neonatal Outcomes in Complicated Pregnancy, Accompanied by Placental Insufficiency.
Redox disbalance in placental cells leads to the hyperproduction of reactive oxygen species (ROS), it mediates the dysregulation of the maternal immune tolerance to a semi-allogenic fetus, inducing pro-inflammatory reactions, and it plays a central role in perinatal complications and neonatal disease programming. Microvesicles, which provide transplacental communication between a mother and fetus, contain microRNAs (miRNAs) that are sensitive to oxidative stress (OS) mediators and can control the balance of ROS production and utilization in target cells. In the context of this paradigm, we evaluated the markers of redox balance—MDA and 4-HNE for OS and GPx, and SOD, CAT, and GSH for the antioxidant system in the cord blood plasma of newborns diagnosed with fetal growth restriction (FGR)—by using polarography, spectrophotometry, and Western blotting. The expression of miRNAs associated with OS, immune and inflammatory responses in the blood plasma of newborns with intrauterine pneumonia (IP), neonatal sepsis (NS) and respiratory distress syndrome (RDS) was evaluated by a quantitative RT-PCR. Significant differences in the MDA level and reduced GPx and CAT activity were co-found for early-onset FGR (i.e., <34 gestational age). Significant correlations were found with a low birth weight by Apgar scores with reduced levels of antioxidant enzymes. Indeed, the level of OS markers increased in early-onset FGR in newborns with an extremely low body weight and high echogenicity of the periventricular zones, and reduced in late-onset FGR in newborns with IP, hyperbilirubinemia, intraventricular hemorrhage (IVH) and cerebral cysts. A prognostic model (AUC = 1; cutoff—0.5) was developed to assess the risk of IVH in newborns diagnosed with FGR based on the assessment of the OS markers (i.e., MDA + 4 HNE + CAT + GSH). A significant increase in the miR-127-3p expression was found in the plasma of newborns with NS (<32 GA; p ≤ 0.03 and >32 GA; p ≤ 0.009), IP (>32 GA; p ≤ 0.0001), and RDS (>32 GA; p ≤ 0.03). At the same time, the expression of miR-25-3p (p ≤ 0.03) was increased only in newborns with NS (>32 GA; p ≤ 0.03). The risk of developing IVH for premature newborns with IP (AUC = 0.8; cutoff—0.6) and NS (AUC = 0.68; cutoff—0.49) was assessed based on the miR-25-3p and miR-127-3p expression. Several key transcription factors were identified as the targets of studied miRNA since they are involved in the regulation of OS (NRF2), signaling and activation of the immune response (PRDM1, CCL26) and, also, inflammatory responses (NFKB1). The study of these miRNAs showed that they are involved in the modulation of processes leading to perinatal complications. Moreover, miR-127-3p is related to pro-inflammatory reactions and the formation of the macrophage phenotype in newborns with IP, NS, and RDS, while miR-25-3p is associated with an inhibition of macrophage migration and activation of antioxidant enzymes, which may prevent the development of oxidative damage in newborns with NS.
PubMed: 36670868
DOI: 10.3390/antiox12010006