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Critical Reviews in Analytical Chemistry 2019Prostate cancer is the second most common malignant type of cancer in men and fifth among fatal types of cancer. Because drugs used in prostate cancer, such as in many... (Review)
Review
Prostate cancer is the second most common malignant type of cancer in men and fifth among fatal types of cancer. Because drugs used in prostate cancer, such as in many other drugs, are also present in low concentrations in body fluids, it is important to develop highly sensitive and sensitive methods that allow the correct amount of prostate cancer drugs to be determined at low concentrations in biological specimens. Electrochemical approaches for the quantitation of prostate cancer drugs have several advantages over other common techniques, including sensitive, selective, fast, broad linear concentration range. Over the years, various modified working electrodes such as graphite, glassy carbon, carbon paste electrode, carbon composites, and nanotubes have been developed and used in various forms for electroanalytical determinations of prostate cancer drugs. One of the important developments in the electroanalytical chemistry is the surface modification of electrodes. The various sensing strategies for the electrochemical detection techniques such as voltammetry, polarography, amperometry, potentiometry have been used for prostate cancer drugs. This review focuses on studies published over the past years on sensitive and selective detection of prostate cancer drugs in biological fluids and dosage forms using electrochemical methods.
Topics: Antineoplastic Agents; Dosage Forms; Electrochemical Techniques; Electrodes; Humans; Male; Prostatic Neoplasms
PubMed: 30636444
DOI: 10.1080/10408347.2018.1538768 -
Zhurnal Nevrologii I Psikhiatrii Imeni... 2019To study the possibility of applying methods of mathematical modeling in assessing the severity of ischemic stroke in patients with arterial hypertension.
AIM
To study the possibility of applying methods of mathematical modeling in assessing the severity of ischemic stroke in patients with arterial hypertension.
MATERIAL AND METHODS
The study included 80 patients with ischemic stroke. Blood pressure was measured. Transcutaneous polarography was used to measure the oxygen tension in tissues. Measurements of gas composition of the blood and thickness of the intima-media complex were performed. The level of stable metabolites of nitric oxide in the blood was determined. Measurement of endothelin-1 in the blood was performed by enzyme immunoassay. NIHSS scale was administered to assess the neurological status. Patients were divided into 3 groups according to the degree of neurological deficit. The control group consisted of 10 people without signs of vascular pathology.
RESULTS
An increase in the neurological deficit was accompanied by an increase in the level of endothelin-1, a decrease in the level of stable metabolites of nitric oxide, and a reduction in tissue oxygenation. Discriminative functions were developed for each group of patients using discriminant analysis based on the data obtained in the study. The most statistically significant were two signs: the level of systolic blood pressure and the content of stable metabolites of nitric oxide in the blood.
CONCLUSION
Thus, the imbalance in the indices of endothelium-dependent mechanisms of vascular tone regulation reflect the severity of the condition in ischemic stroke. The method of discriminant analysis allows the creation of sufficiently reliable mathematical models that can have practical significance, and can be used as a method of clarifying the severity of the condition in the acute period of ischemic stroke.
Topics: Blood Pressure; Brain Ischemia; Humans; Hypertension; Models, Theoretical; Nitric Oxide; Stroke
PubMed: 32207713
DOI: 10.17116/jnevro201911912213 -
Experimental Oncology Dec 2018To study the effect of Ferroplat (FrP) on the indexes of pro/antioxidant balance and energy metabolism in breast cancer cells of different malignancy degree and...
AIM
To study the effect of Ferroplat (FrP) on the indexes of pro/antioxidant balance and energy metabolism in breast cancer cells of different malignancy degree and different sensitivity to drug therapy.
MATERIALS AND METHODS
The study was carried out on breast cancer cells of low (T47D, MCF-7) and high malignancy degree (MCF-7/DDP (cisplatin-resistant), MDA-MB-231, MDA-MB-468) using cell culture techniques, immunocytochemical, biochemical, biophysical methods, flow cytometry and polarography.
RESULTS
We established that the addition of FrP to the culture medium reduces the activity of glucose-6-phosphate dehydrogenase (G6PDH), superoxide dismutase (SOD) and the level of non-protein thiols by 32-41% (p < 0.05). At the same time, there was an increase of the total level of ROS and the rate of NO generation by inducible NO synthase by 1.7-2.5 times (p < 0.05). This testifies that FrP disturbs the antioxidant balance in cells, resulting in their death. Also, the use of FrP led to a decrease in the rate of oxygen absorption in MCF-7 and T47D cells by 26% and 25%, respectively (p < 0.05). In cells of high malignancy degree this index decreased by 38-40% under the influence of FrP. Incubation of MCF-7 and T47D cells with the indicated agent also reduced the content of phospholipid cardiolipin by 15-16% (p < 0.05), and in MDA-MB-231, MCF-7/DDP, MDA-MB-468 cells - by 29%, 30% and 32%, respectively. In addition, the effect of FrP caused a decrease in the levels of Mg2+ and lactate in MCF-7 and T47D cells by 21-29% and 14-24%, respectively, whereas in MDA-MB-231, MDA-MB-468, MCF-7/DDP cells - by 34-38% and 32-35%, respectively. In this case, the agent raised the level of glucose in the cells of low malignancy degree by 20-23% (p < 0.05), and in the cells of high malignancy degree and with the phenotype of drug resistance - by 31-36%. However, the nanocomposite did not affect the activity of lactate dehydrogenase in all studied breast cancer cells.
CONCLUSION
The study has shown that FrP has an effect on the pro/antioxidant balance and energy metabolism of cancer cells. In addition, the denoted effect of FrP was more pronounced in the breast cancer cells with a high malignancy degree and the phenotype of drug resistance.
Topics: Antineoplastic Agents; Antioxidants; Breast Neoplasms; Cell Line, Tumor; Cisplatin; Energy Metabolism; Female; Humans; Magnets; Nanocomposites; Oxygen Consumption; Superoxide Dismutase
PubMed: 30593756
DOI: No ID Found -
Bioanalysis Jan 2019Differential pulse polarography was used for the concurrent analysis of the coadministered dantrolene (DAN) and indomethacin (IND) in plasma.
AIM
Differential pulse polarography was used for the concurrent analysis of the coadministered dantrolene (DAN) and indomethacin (IND) in plasma.
MATERIALS & METHODS
DAN and IND, Hanging mercury drop electrode and Britton-Robinson buffer at pH 5 were used. In plasma, cathodic reduction of DAN nitro group and its active metabolite at -0.2 V was done. IND was analyzed after carbonyl group reduction at -1.1 V.
RESULTS
Drugs determination in rat plasma with good recoveries and low limit of quantitation was done. Application to trace analysis of drugs in rat plasma was done with C and T determination.
CONCLUSION
This technique shows high sensitivity, simplicity and low cost. The method is US FDA validated and it is applicable to human level.
Topics: Animals; Calibration; Dantrolene; Electrochemistry; Electrodes; Indomethacin; Male; Polarography; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Sensitivity and Specificity
PubMed: 30539646
DOI: 10.4155/bio-2018-0165 -
Frontiers in Bioscience (Landmark... Jan 2019First steps in brain research progress were made during the early 19 century, whose swift progress was accompanied by the discovery of monoamines and their localization... (Review)
Review
First steps in brain research progress were made during the early 19 century, whose swift progress was accompanied by the discovery of monoamines and their localization in the brain. Since the discovery of polarography in 1924, several variations of electrochemical techniques for and determination of monoamines have been developed, with the most prevalent being microdialysis and voltammetry. Voltammetry takes advantage of the chemical property of certain species to oxidize, videlicet to produce a current that can be measured and subsequently interpreted to concentration gradient. Voltammetric techniques require a three-electrode system and operate under the application of a potential at the working electrode, responsible to evoke the oxidation processes. Methodological variations include, among others, amperometry, cyclic voltammetry, differential pulse voltammetry, etc. In the present work we attempted to review the available knowledge on voltammetry, its uses and future endeavors since voltammetry is a promising method towards the investigation of brain and central nervous system physiology and pathophysiology.
Topics: Animals; Biogenic Monoamines; Central Nervous System; Dopaminergic Neurons; Electrochemical Techniques; Electrodes; Humans; Oxidation-Reduction; Reproducibility of Results
PubMed: 30468653
DOI: 10.2741/4715 -
Frontiers in Physiology 2018Cardiovascular complications are the major cause of mortality and morbidity in diabetic patients. The changes in myocardial structure and function associated with... (Review)
Review
Cardiovascular complications are the major cause of mortality and morbidity in diabetic patients. The changes in myocardial structure and function associated with diabetes are collectively called diabetic cardiomyopathy. Numerous molecular mechanisms have been proposed that could contribute to the development of diabetic cardiomyopathy and have been studied in various animal models of type 1 or type 2 diabetes. The current review focuses on the role of sodium (Na) in diabetic cardiomyopathy and provides unique data on the linkage between Na flux and energy metabolism, studied with non-invasive Na, and P-NMR spectroscopy, polarography, and mass spectroscopy. Na NMR studies allow determination of the intracellular and extracellular Na pools by splitting the total Na peak into two resonances after the addition of a shift reagent to the perfusate. Using this technology, we found that intracellular Na is approximately two times higher in diabetic cardiomyocytes than in control possibly due to combined changes in the activity of Na-K pump, Na/H exchanger 1 (NHE1) and Na-glucose cotransporter. We hypothesized that the increase in Na activates the mitochondrial membrane Na/Ca exchanger, which leads to a loss of intramitochondrial Ca, with a subsequent alteration in mitochondrial bioenergetics and function. Using isolated mitochondria, we showed that the addition of Na (1-10 mM) led to a dose-dependent decrease in oxidative phosphorylation and that this effect was reversed by providing extramitochondrial Ca or by inhibiting the mitochondrial Na/Ca exchanger with diltiazem. Similar experiments with P-NMR in isolated superfused mitochondria embedded in agarose beads showed that Na (3-30 mM) led to significantly decreased ATP levels and that this effect was stronger in diabetic rats. These data suggest that in diabetic cardiomyocytes, increased Na leads to abnormalities in oxidative phosphorylation and a subsequent decrease in ATP levels. In support of these data, using P-NMR, we showed that the baseline β-ATP and phosphocreatine (PCr) were lower in diabetic cardiomyocytes than in control, suggesting that diabetic cardiomyocytes have depressed bioenergetic function. Thus, both altered intracellular Na levels and bioenergetics and their interactions may significantly contribute to the pathology of diabetic cardiomyopathy.
PubMed: 30405433
DOI: 10.3389/fphys.2018.01473 -
Biochimica Et Biophysica Acta.... Dec 2018In Photosystem II (PSII), the MnCaO-cluster of the active site advances through five sequential oxidation states (S to S) before water is oxidized and O is generated....
In Photosystem II (PSII), the MnCaO-cluster of the active site advances through five sequential oxidation states (S to S) before water is oxidized and O is generated. The V185 of the D1 protein has been shown to be an important amino acid in PSII function (Dilbeck et al. Biochemistry 52 (2013) 6824-6833). Here, we have studied its role by making a V185T site-directed mutant in the thermophilic cyanobacterium Thermosynechococcus elongatus. The properties of the V185T-PSII have been compared to those of the WT*3-PSII by using EPR spectroscopy, polarography, thermoluminescence and time-resolved UV-visible absorption spectroscopy. It is shown that the V185 and the chloride binding site very likely interact via the H-bond network linking Tyr and the halide. The V185 contributes to the stabilization of S into the low spin (LS), S = 1/2, configuration. Indeed, in the V185T mutant a high proportion of S exhibits a high spin (HS), S = 5/2, configuration. By using bromocresol purple as a dye, a proton release was detected in the STyr → STyr transition in the V185T mutant in contrast to the WT*3-PSII in which there is no proton release in this transition. Instead, in WT*3-PSII, a proton release kinetically much faster than the STyr → STyr transition was observed and we propose that it occurs in the STyr → STyr intermediate step before the STyr → STyr transition occurs. The dramatic slowdown of the STyr → STyr transition in the V185T mutant does not originate from a structural modification of the MnCaO cluster since the spin S = 3 S EPR signal is not modified in the mutant. More probably, it is indicative of the strong implication of V185 in the tuning of an efficient relaxation processes of the H-bond network and/or of the protein.
Topics: Electron Spin Resonance Spectroscopy; Kinetics; Luminescent Measurements; Models, Molecular; Oxygen; Photosystem II Protein Complex; Synechococcus; Time Factors; Valine
PubMed: 30342040
DOI: 10.1016/j.bbabio.2018.10.003 -
Reactive Oxygen Species (Apex, N.C.) Sep 2018In this work, we investigated the effects of graphene quantum dots (GQDs) on copper redox-mediated free radical generation and cell injury. Using electron paramagnetic...
In this work, we investigated the effects of graphene quantum dots (GQDs) on copper redox-mediated free radical generation and cell injury. Using electron paramagnetic resonance (EPR) spectrometry in conjunction with 5,5-dimethyl-1-pyrroline -oxide (DMPO) as a spin trap, we found that GQDs at a concentration as low as 1 μg/ml significantly inhibited Cu(II)/HO-mediated hydroxyl radical formation. GQDs also blocked Cu(II)-catalyzed nucleophilic addition of HO to DMPO to form a DMPO-OH adduct in the absence of HO, suggesting a potential for GQDs to inhibit copper redox activity. Indeed, we observed that the presence of GQDs prevented HO-mediated reduction of Cu(II) to Cu(I) though GQDs themselves also caused the reduction of Cu(II) to Cu(I). To further investigate the effects of GQDs on copper redox activity, we employed the Cu(II)/hydroquinone system in which copper redox activity plays an essential role in the oxidation of hydroquinone to semiquinone radicals with consequent oxygen consumption. Using oxygen polarography as well as EPR spectrometry, we demonstrated that the presence of GQDs drastically blocked the oxygen consumption and semiquinone radical formation resulting from the reaction of Cu(II) and hydroquinone. These results suggested that GQDs suppressed free radical formation via inhibiting copper redox activity. Lastly, using cultured human cardiomyocytes, we demonstrated that the presence of GQDs also protected against Cu(II)/HO-mediated cardiac cell injury as indicated by morphological changes (e.g., cell shrinkage and degeneration). In conclusion, our work shows, for the first time, the potential for using GQDs to counteract copper redox-mediated biological damage.
PubMed: 30177973
DOI: 10.20455/ros.2018.855 -
Acta Physiologica (Oxford, England) Feb 2019The subsarcolemmal (SSM) and interfibrillar (IFM) mitochondria in skeletal muscle appear to have distinct biochemical properties affecting metabolism in health and...
AIM
The subsarcolemmal (SSM) and interfibrillar (IFM) mitochondria in skeletal muscle appear to have distinct biochemical properties affecting metabolism in health and disease. The isolation of mitochondrial subpopulations has been a long-time challenge while the presence of a continuous mitochondrial reticulum challenges the view of distinctive SSM and IFM bioenergetics. Here, a comprehensive approach is developed to identify the best conditions to separate mitochondrial fractions.
METHODS
The main modifications to the protocol to isolate SSM and IFM from rat skeletal muscle were: (a) decreased dispase content and homogenization speed; (b) trypsin treatment of SSM fractions; (c) recentrifugation of mitochondrial fractions at low speed to remove subcellular components. To identify the conditions preserving mitochondrial function, integrity, and maximizing their recovery, microscopy (light and electron) were used to monitor effectiveness and efficiency in separating mitochondrial subpopulations while respiratory and enzyme activities were employed to evaluate function, recovery, and integrity.
RESULTS
With the modifications described, the total mitochondrial yield increased with a recovery of 80% of mitochondria contained in the original skeletal muscle sample. The difference between SSM and IFM oxidative capacity (10%) with complex-I substrate was significant only with a saturated ADP concentration. The inner and outer membrane damage for both subpopulations was <1% and 8%, respectively, while the respiratory control ratio was 16.
CONCLUSION
Using a multidisciplinary approach, conditions were identified to maximize SSM and IFM recovery while preserving mitochondrial integrity, biochemistry, and morphology. High quality and recovery of mitochondrial subpopulations allow to study the relationship between these organelles and disease.
Topics: Animals; Cell Fractionation; Cytochromes c; Electron Transport; Male; Mitochondria, Muscle; Mitochondrial Proteins; Muscle, Skeletal; Oxidative Phosphorylation; Rats; Rats, Wistar
PubMed: 30168663
DOI: 10.1111/apha.13182 -
Chemosphere Oct 2018The duration of in-situ generation of iron corrosion products (FeCPs) prior the remediation process (so called "aging" of metallic iron (Fe)), was found as the key...
The duration of in-situ generation of iron corrosion products (FeCPs) prior the remediation process (so called "aging" of metallic iron (Fe)), was found as the key parameter affecting the efficiency of Fe for water remediation. Batch experiments were performed in buffered solutions (pH 4.0, 4.7 and 5.5) and under oxic conditions (presence of dissolved oxygen) using Zn as probe contaminant. The time-dependent (0-16 d) concentration changes of aqueous Fe and Zn were monitored using differential pulse polarography (DPP). During the time of pre-corrosion varying from 0 to 6 d, an "induction period" of the corrosion occurs in the first one - 2 h when no Fe ion is released in the solution. After this period, Fe was identified in solution and its concentration progressively increases up to 6 h, then starts to decrease and after 6 d nearly disappears. Experiments with Zn reveal that the most efficient Fe remediation occurs after 6 h of pre-corrosion. This coherence thus proves that the presence, the amount and the age of FeCPs ("degree" of corrosion) significantly impact the removal efficiency of Zn in Fe/HO systems. The present study severely refute the wording 'reactivity loss' and states that progress in designing sustainable Fe/HO systems will not be achieved before the role of "active" FeCPs is clarified.
Topics: Corrosion; Electrochemistry; Ferrous Compounds; Water Pollutants, Chemical
PubMed: 29957522
DOI: 10.1016/j.chemosphere.2018.06.080