Oxidative stress, lipid profile and liver functions in average Egyptian long term depo medroxy progesterone acetate (DMPA) users

Depo-medroxy progesterone acetate (DMPA, Depo-Provera) is used in more than 80 countries as a long-acting contraceptive administered as a single intramuscular(i.m) injection of 150 mg/3 months. The present study was set up to investigate the effects of DMPA on 80 average Egyptian women classified into four groups comprising those using the drug for one, two, three and four years, respectively, compared to a control group (N = 20) of married non-hormonally - treated women of similar ages. The drug showed a transient significant elevation of alanine aminotransferase activity (ALT)without an apparent effect on other liver indices, namely total bilirubin (T.Bil) level,aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities. Only the low density/high density lipoproteins cholesterol ratio (LDLC/HDLC) was gradually and non-significantly (ns) increased in comparison to control group, however, neither total cholesterol (TC) nor triglycerides (TG) were affected by the drug. The lipid peroxide product malondialdehyde (MDA) was significantly elevated in an gradual manner with a corresponding decrease in reduced glutathione (GSH), without any change in blood nitric oxide (NO) levels. It can be concluded that DMPA may be considered as a safe contraceptive medication for the studied group of women, but that special care should be exercised for cardiovascular, hepatic and other patients more sensitive to the harmful effects of free radicals. Alternatively, supportive medications are advisable for each exposed case to secure against the possible irreversible adverse effects of the drug by continuous use. In addition, annual re-evaluation is much more advisable despite the proven safety of the drug.     

Oxidation of bis(µ-halo)-bis[(diamine)copper(I)] complexes [LCuX]2; L = TMED, X = Cl, Br or I, L = TEED or TMPD, X = Cl, with the two electron organo oxidizing agent, tetrachloro-1,2-benzoquinone(TClBQ) in aprotic media: models for intermediates in catalytic catechol oxidase

Well structurally characterized bis(μ-halo)-bis[(diamine)copper(I)] complexes [LCuX]₂; L = TMED, tetramethylethylenediamine, X = Cl, Br or I and L = TEED, tetraethylethylenediamine, or TMPD, tetramethylpropane-diamine, X = Cl, react quantitatively with tetrachloro-1,2-benzoquinone (TClBQ) as two electron oxidizing agent in O₂-free CH₂Cl₂ or PhNO₂ to form a dimeric [LCuX]₂Cat (Cat = catechol) as indicated by cryoscopic measurements. Infrared spectra was in agreement with total reduction of TClBQ to the corresponding catechol. Electronic spectra indicated a dimeric distorted five coordinate Cu(II) and EPR spectra suggested a square pyramidal arrangement around the Cu(II) centers in [LCuX]₂Cat. The ligand field strength for diamine ligand was higher for the five member chelating ring (TMED) relative to the six membered one (TMPD). Electrochemical reduction of Cu centers in [LCuX]₂Cat were irreversible and occurred at a less negative potential when X = I.     

Mono- and binuclear Schiff base complexes derived from glycine, 3-acetylpyridine and transition metal ions

Binuclear Schiff base complexes derived from glycine (Gly) and 3-acetylpyridine (3-APy) in the presence of M(OAc)₂ [M = Co^II, Ni^II, Cu^II, Zn^II and Cd^II] have been synthesized. The role of pH in promoting the condensation of glycine and 3-acetylpyridine, as well as the substitution of acetates by hydroxide ion, has been discussed. Also, the reaction of glycine with 3-acetylpyridine in the presence of MCl₂ [M = Co^II and Ni^II] and MCl₃ [M = Fe^III and Cr^III] yields mono- and/or binuclear complexes containing both of glycine and 3-acetylpyridine without condensation. Both types of complex were isolated and characterized by chemical analysis, conductance, spectral (u.v.–vis., i.r., and ¹H-n.m.r.), magnetic and thermal measurements.     

Differential estimation of U(VI) and U(IV) ions in aqueous solutions by Arsenazo 1

The spectrophotometric determination of pure U(IV) or U(VI) ions in solution with Arsenazo I is greatly dependant on the pH of the solutions. The experimental conditions for the differential estimation of the different oxidation states of U ions, in the same sample, using Arsenazo I have been identified and implemented. The results showed that the applied method is rather rapid and accurate.     

Direct UPLC-MS-MS validated method for the quantification of 5-aminolevulinic acid: application to in-vitro assessment of colonic-targeted oral tablets

A reliable, sensitive, specific, and rapid ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS-MS) method was developed for the determination of 5-aminolevulinic acid (5-ALA) in orally-administered colonic delivery system. The prepared system is a compression-coated tablet using granulated chitosan as the coat layer. L-Tyrosine (TYR) was used as an internal standard with no need for derivatization. The chromatographic system consisted of Acquity UPLC BEH C18 column and isocratic mobile phase composed of acetonitrile and 0.1% formic acid with a flow rate of 2.5 min. The assay was based on ESI+ mode in a multiple reaction monitoring (MRM) transitions at m/z 132.08 > 86.0 and m/z 132.08 > 114.0 and m/z 182.1 > 91.2 for 5-ALA and TYR, respectively. Limit of quantification was 5.0 ng/mL and the calibration curve was linear (r(2) = 0.994). Within-run precision and between-run repeatability were expressed as relative standard deviation and were lower than 2.5%. The recoveries from control samples were > 95%. The method was successfully applied for evaluation in assay and release profile of 5-ALA colon targeted tablets media containing suspended rat cecal contents pH 6.8 medium (colonic) for colonic delivery.     

Inference for a progressive stress model from Weibull distribution under progressive type-II censoring

Based on progressively type-II censored samples, this paper considers progressive stress accelerated life tests when the lifetime of an item under use condition follows the Weibull distribution with a scale parameter satisfying the inverse power law. It is assumed that the progressive stress is directly proportional to time and the cumulative exposure model for the effect of changing stress holds. Point estimation of the model parameters is obtained graphically by using Weibull probability paper plot that serves as a tool for model identification and also by using the maximum likelihood method. Interval estimation is performed by finding approximate confidence intervals (CIs) for the parameters as well as the studentized-t and percentile bootstrap CIs. Monte Carlo simulation study is carried out to investigate the precision of the estimates and compare the performance of CIs obtained. Finally, two examples are presented to illustrate our results.     

Flutter analysis of a viscoelastic tapered wing under bending–torsion loading

The dynamic stability of a tapered viscoelastic wing subjected to unsteady aerodynamic forces is investigated. The wing is considered as a cantilever tapered Euler–Bernoulli beam. The beam is made of a linear viscoelastic material where Kelvin–Voigt model is assumed to represent the viscoelastic behavior of the material. The governing equations of motion are derived through the extended Hamilton’s principle. The resulting partial differential equations are solved via Galerkin’s method along with the classical flutter investigation approach. The developed model is validated against the well-known Goland wing and HALE wing and good agreement is obtained. Different solution methods, namely; the k method, the p-k method, and the flutter determinant method are compared for the case of elastic wing. However, when the viscoelastic damping is introduced, the k and p-k methods become less effective. The flutter determinant method is modified and employed to carry out non-dimensional parametric study on the Goland wing. The study includes the effects of parameters such as the taper ratio, the density ratio, the viscoelastic damping of wing structure and many other parameters on the flutter speed and flutter frequency. The study reveals that a tapered wing would be more dynamically stable than a uniform wing. It is also observed that the viscoelastic damping provides wider stability region for the wing. The investigation shows that the density ratio, bending-to-torsion frequency ratio, and the radius of gyration have significant effects on the dynamic stability of the wing. Based on the obtained results, a wing with an elastic center and inertial center that are located closer to the mid-chord would be more dynamically stable.