Prevention of methylprednisolone acetate-induced osteoporosis with calcium administration in rat model

Glucocorticoid steroids are widely used as anti-inflammatory and immunosuppressive medications and are well known to induce osteoporosis. In Present study 24 rats were randomly divided into four groups (n=6): Group A (control), Group B (sham)that was treated only by normal saline for 1 month.Group C that was treated by methylprednisolone acetate alone (0.2 mg/kg) for 1 month. Group D that was treated by methylprednisolone acetate (0.2 mg/kg) and oral calcium supplementation (15 mg/kg) for 1 month. Changes in concentration of bone metabolic markers such as osteocalcine, acid phosphatase and calcium were evaluated before and after treatment. Bone mineral density (BMD) of lumbar vertebrae was also measured by dual energy X ray absorptiometry (DEXA). The results showed that concentration mean of serum acid phosphatase was increased significantly (P � 0.05) in C and D groups in compared to A and B groups. The concentration mean of serum osteocalcine in group C was decreased significantly (P � 0.05) in comparison to A and B groups but increased significantly in the group D in comparison to group C. The concentration mean of serum calcium was decreased significantly (P � 0.05) in C and D groups in compared to A and B groups. The bone mineral density (g/cm2) was decreased significantly (P � 0.05) in group C in compared to A and B groups. This increased significantly in group D in compared to group C. These results are compatible with the view that low doses of methylprednisolone acetate decreases bone formation and increase bone resorption in the lumbar vertebrae of rats. Calcium administration decreased effects of methylprednisolone. © 2009 Tehran University of Medical Sciences. All rights reserved

Synthesis and characterization of Sm2(MoO4)3, Sm2(MoO4)3/GO and Sm2(MoO4)3/C3N4 nanostructures for improved photocatalytic performance and their anti-cancer the MCF-7 cells

Samarium molybdate nanoparticles (Sm2(MoO4)3) were prepared through a hydrothermal procedure and were used to form various composites with graphene oxide (GO) and carbon nitride (C3N4). The changes in the dimensions and morphology of the products were prepared using template agents like cetyltrimethyl ammonium bromide (CTAB), Sodium dodecyl sulfate (SDS) (�90), Triton X-100 (90), Polyvinyl alcohol (95), Ethylene glycol (�99), and polyvinylpyrrolidone (PVP). DRS analysis indicated band gap for the Sm2(MoO4), Sm2(MoO4)3/GO, and Sm2(MoO4)3/C3N4 as 3.75, 3.15, and 3.4 respectively. The characteristics of the prepared nanostructures were studied through X-ray diffraction (XRD), energy dispersive X-ray (EDX), and scanning electron microscopy (SEM). Finally, the activity of the prepared Sm2(MoO4)3 as photo-catalysts for the degradation of different organic dyes such as methyl orange (MO), methylene blue (MB), and rhodamine B (Rh B) was evaluated. The photocatalytic property of Sm2(MoO4)3/C3N4 and Sm2(MoO4)3/GO for the degradation of MO, was obtained. Based on the empirical data Sm2(MoO4)3/C3N4 had the strongest photodegradation effect as compared to the other compounds tested after around 40 min. BET analysis revealed that the specific surface area of the Sm2(MoO4)3 nanocomposite prepared using C3N4 is 15 times that of in the absence of C3N4. Also, the cytotoxicity of synthesized samples was evaluated using MTT assay against human cell lines MCF-7 (cancer), and its IC50 was about 125 mg/L. © 202

A modified sensitive carbon paste electrode for 5-fluorouracil based using a composite of praseodymium erbium tungstate

This paper describes the modification of a modified carbon paste electrode (CPE) using nanoparticles of praseodymium erbium tungstate (Pr:Er). The modified electrode was used for the sensitive voltammetric detection of an anticancer drug (5-fluorouracil (5-FU)) using. The modified-CPE was evaluated using cyclic voltammetry (CV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) and the resulting data showed the irreversible 5-fluorouracil oxidation peak around 1.0 V vs. Ag/AgCl. Some key parameters such as pH, the amount of the modifier, potential amplitude, step potential and frequency were studied and optimized. The square wave voltammetry (SWV) analytical calibration curve was linear in the range of 0.01�50 μM, with a detection limit of 0.98 nM analyses. The electron transfer coefficient (α) was also determined to be 0.76. The analyte concentration was also determined in pharmaceutical formulations and recovery percentages were found to be in the range of 96�102. The sensor had good reproducibility and repeatability with acceptable RSD values of 3.6, and 1.02 and a rather long-term stability of around one month. The as-synthesized nanoparticles were also characterized using FESEM, TEM, FTIR and XRD techniques. © 2020 Elsevier B.V

Electrochemical determination of the antipsychotic medication clozapine by a carbon paste electrode modified with a nanostructure prepared from titania nanoparticles and copper oxide

A nanostructure was prepared from titania nanoparticles and copper oxide (TiO2NP@CuO) and used to modify a carbon paste electrode (CPE). The modified CPE is shown to enable sensitive voltammetric determination of the drug clozapine (CLZ). The sensor was characterized by various techniques and some key parameters were optimized. Under the optimum conditions and at a working potential of 0.6 V (vs. Ag/AgCl), the modified CPE has two linear response ranges, one from 30 pmol L�1 to 4 nmol L�1 of CLZ, the other from 4 nmol L�1 to 10 μmol L�1. The detection limit is as low as 9 pM. The transfer coefficient (α) and catalytic rate constant (kcat) were calculated and the reliability of the sensor was estimated for CLZ sensing in real samples where it gave satisfactory results. Figure not available: see fulltext.. © 2019, Springer-Verlag GmbH Austria, part of Springer Nature

Aharonov-Bohm effect in graphene

We investigate experimentally transport through ring-shaped devices etched in graphene and observe clear Aharonov-Bohm conductance oscillations. The temperature dependence of the oscillation amplitude indicates that below 1 K the phase coherence length is comparable to or larger than the size of the ring. An increase in the amplitude is observed at high magnetic field, when the cyclotron diameter becomes comparable to the width of the arms of the ring. By measuring the dependence on gate voltage, we also observe an unexpected linear dependence of the oscillation amplitude on the ring conductance, which had not been reported earlier in rings made using conventional metals or semiconducting heterostructures.Comment: 14 pages, 5 figure

Sonochemical synthesis of ErVO4/MnWO4 heterostructures: Application as a novel nanostructured surface for electrochemical determination of tyrosine in biological samples

Present strategy introduces a novel method established for the synthesis of spherical shape ErVO4/MnWO4 heterostructures by a sonochemical method. This heterostructures with optima morphology can be synthesized by changing power and time ultrasound irradiation without any capping agent. BET analysis revealed that ErVO4/MnWO4 prepared in the presence of ultrasonic procedure has 75 times specific surface area as much as that of those was produced in the absence of ultrasonic rays. A variety of analyses (i.e., BET, XRD, TEM, EDS, FT-IR, and SEM) were applied for characterization of the ErVO4/MnWO4. Next, a selective and sensitive nanostructured sensor based on ErVO4/MnWO4 nanocomposite modified carbon paste electrode (ErVO4/MnWO4/CPE) was constructed for electrochemical detection of tyrosine (Tyr). The electrochemical characterizations were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Compared with the unmodified CPE, the oxidation peak current was significantly enhanced for Tyr. The impact of effective parameters on voltammetric response of Tyr was analyzed with design of experiments (DOE) and response surface methodology (RSM). Under the optimized conditions, the oxidation peak current of Tyr was linear over a range of 0.08�400.0 μM with a detection limit of 7.7 nM. Finally, the usage of the proposed method was confirmed by the recovery tests of Tyr in biological samples. © 201

Design, modeling, expression, and chemoselective PEGylation of a new nanosize cysteine analog of erythropoietin

Reza Ahangari Cohan1, Armin Madadkar-Sobhani2,3, Hossein Khanahmad1, Farzin Roohvand4, Mohammad Reza Aghasadeghi4, Mohammad Hossein Hedayati5, Zahra Barghi5, Mehdi Shafiee Ardestani4, Davoud Nouri Inanlou1, Dariush Norouzian11Research and Development Department, Production and Research Complex, Pasteur Institute of Iran, Tehran, Iran; 2Department of Bioinformatics, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran; 3Department of Life Sciences, Barcelona Supercomputing Center, Barcelona, Spain; 4Hepatitis and AIDS Department, Pasteur Institute of Iran, Tehran, Iran; 5Quality Control Department, Production and Research Complex, Pasteur Institute of Iran, Tehran, IranBackground: Recombinant human erythropoietin (rhEPO) is considered to be one of the most pivotal pharmaceutical drugs in the market because of its clinical application in the treatment of anemia-associated disorders worldwide. However, like other therapeutic proteins, it does not have suitable pharmacokinetic properties for it to be administrated at least two to three times per week. Chemoselective cysteine PEGylation, employing molecular dynamics and graphics in in silico studies, can be considered to overcome such a problem.Methods: A special kind of EPO analog was elicited based on a literature review, homology modeling, molecular dynamic simulation, and factors affecting the PEGylation reaction. Then, cDNA of the selected analog was generated by site-directed mutagenesis and subsequently cloned into the expression vector. The construct was transfected to Chinese hamster ovary/dhfr- cells, and highly expressed clones were selected via methotrexate amplification. Ion-immobilized affinity and size exclusion (SE) chromatography techniques were used to purify the expressed analog. Thereafter, chemoselective PEGylation was performed and a nanosize PEGylated EPO was obtained through dialysis. The in vitro biologic assay and in vivo pharmacokinetic parameters were studied. Finally, E31C analog Fourier transform infrared, analytical SE-high-performance liquid chromatography, zeta potential, and size before and after PEGylation were characterized.Results: The findings indicate that a novel nanosize EPO31-PEG has a five-fold longer terminal half-life in rats with similar biologic activity compared with unmodified rhEPO in proliferation cell assay. The results also show that EPO31-PEG size and charge versus unmodified protein was increased in a nanospectrum, and this may be one criterion of EPO biologic potency enhancement.Discussion: This kind of novel engineered nanosize PEGylated EPO has remarkable advantages over rhEPO.Keywords: nanoPEGylated EPO, cysteine PEGylation, pharmacokinetic propert