ALZHEIMER'S DISEASE, AN ASSOCIATION OR A COMPLICATION OF PAGET'S DISEASE? STUDY OF AN OBSERVATION IN GUINEA.

If Paget's disease can undermine Alzheimer's disease, there is the possibility of an association between Alzheimer's disease and Paget's disease. We report the observation of an 81-year-old hypertensive patient with Alzheimer's disease, who presented with an isolated increase in alkaline phosphatase, which led to the discovery of Paget's disease. The physician must therefore be careful to distinguish between genuine Alzheimer's disease and a neurological complication of Paget's disease.

CLINICAL AND IMAGING ASPECTS OF TALAR OSTEOCHONDRITIS: A CASE REPORT FROM GUINEA.

Osteochondral lesions of the dome of the talus are becoming an increasingly frequent problem in sports traumatology, and questioning is a major element in the diagnostic orientation, as these are usually young, athletic patients. The main part of the diagnosis is based on complementary imaging examinations. We report the clinical observation of an adult patient, an athlete, referred to a rheumatology consultation for chronic pain of the right ankle with a mechanical appearance and difficulty in walking. Clinical and paraclinical examinations (standard X-ray, CT scan and magnetic resonance imaging) finally led to the conclusion of an osteochondritis of the talus.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in Egyptian children with systemic lupus erythematosus: a possible relation to proliferative nephritis.

Introduction Angiotensin-converting enzyme (ACE) is crucial in the pathogenesis of systemic lupus erythematosus through angiotensin II which regulates vascular tone and endothelial functions. Objectives To study the frequency of ACE insertion/deletion (I/D) gene polymorphism in Egyptian children with systemic lupus erythematosus and its possible relation to the renal pathology in cases with lupus nephritis. Subjects and methods The frequency of ACE gene insertion/deletion polymorphism genotypes was determined in 78 Egyptian children with systemic lupus erythematosus and compared to a matched group of 140 healthy controls using polymerase chain reaction. Results The DD genotype of the ACE gene was higher in systemic lupus erythematosus patients when compared to controls ( P<0.0001; odds ratio (OR) 2.4; 95% confidence interval (CI) 1.7-3.3) and the D allele was more frequent than the I allele in systemic lupus erythematosus patients in comparison to controls ( P < 0.0001; OR = 2.2; 95% CI = (1.6-3.1). In the lupus nephritis group, the DD genotype was significantly higher in those with proliferative lupus nephritis when compared to those with non-proliferative lupus nephritis ( P = 0.02; OR = 1.45; 95% CI = 1.4-1.6). Also, patients with proliferative lupus nephritis showed a higher frequency of the D allele ( P < 0.001; OR = 1.98; 95% CI = 1.3-2.9). Conclusion The D allele and DD genotype of the ACE gene appear to be a risk factor for the susceptibility of systemic lupus erythematosus and occurrence of proliferative nephritis in Egyptian children.

Protein/ionic liquid/glassy carbon sensors following analyte focusing by ionic liquid micelle collapse for simultaneous determination of water soluble vitamins in plasma matrices.

Two novel sensors based on human serum albumin (HSA)-ionic liquid (IL) and bovine serum albumin (BSA)-ionic liquid (IL) composites modified glassy carbon electrode (GCE) were produced for simultaneous determination of water soluble vitamins B2, B6 and C in human plasma following analytes focusing by IL micelles collapse (AFILMC). For selective and efficient extraction, vitamins were dissolved in 3.0molL(-1) micellar solution of 1-octyl-3-methyl imidazolium bromide IL. The extracted vitamins were hydrodynamically injected by 25mbar for 20s into a running buffer of 12.5mmolL(-1) phosphate at pH 6.0 followed by electrochemical detection (ECD) on protein/1-octyl-3-methyl imidazolium hexafluorophosphate IL/GC sensors. The chemical stability of proposed sensors was achieved up to 7 days without any decomposition of PF6-based IL/protein and adsorption of interfering ions. In the current work, the sensitivity enhancement factor (SEF) up to 5000-fold was achieved using the AFILMC/ECD setup compared to conventional CE/UV. Under optimal conditions, linear calibration graphs were obtained from 0.5, 0.5 and 1.0 to 1500.0µgmL(-1) of vitamins B2, B6 and C, respectively. Detection limits of analytes were ranged from 180.0 to 520.0ngmL(-1). The proposed AFILMC/ECD setup was successfully applied to the assay of trace level quantification of vitamins in human plasma samples and also their binding constants with HSA and BSA were determined. The concurrent use of IL micelles for the proposed separation and detection processes exhibited some advantages, such as, a reduction of use toxic solvents, an efficient extraction and a direct injection of samples with a short-single run. Furthermore, IL micelles, having variable possibility of interactions, facilitated the successful achievements of AFILMC/ECD setup for the quantification of vitamins in plasma matrices.

Overview of preparedness and response for Middle East respiratory syndrome coronavirus (MERS-CoV) in Oman.

Several countries in the Middle East and around 22 countries worldwide have reported cases of human infection with the Middle East respiratory syndrome coronavirus (MERS-CoV). The exceptionally high fatality rate resulting from MERS-CoV infection in conjunction with the paucity of knowledge about this emerging virus has led to major public and international concern. Within the framework of the national acute respiratory illness surveillance, the Ministry of Health in the Sultanate of Oman has announced two confirmed cases of MERS-CoV to date. The aim of this report is to describe the epidemiological aspects of these two cases and to highlight the importance of public health preparedness and response. The absence of secondary cases among contacts of the reported cases can be seen as evidence of the effectiveness of infection prevention and control precautions as an important pillar of the national preparedness and response plan applied in the health care institutions in Oman.

Molecular-level insights into the reactivity of siloxane-based electrolytes at a lithium-metal anode.

A molecular-level understanding of the reactions that occur at the lithium-metal anode/electrolyte interphase is essential to improve the performance of Li-O(2) batteries. Experimental and computational techniques are applied to explore the reactivity of tri(ethylene glycol)-substituted trimethylsilane (1NM3), a siloxane-based ether electrolyte, at the lithium-metal anode. In situ/ex situ X-ray diffraction and Fourier-transform infrared spectroscopy studies provide evidence of the formation of lithium hydroxide and lithium carbonates at the anode upon gradual degradation of the metallic lithium anode and the solvent molecules in the presence of oxygen. Density functional calculations performed to obtain a mechanistic understanding of the reductive decomposition of 1NM3 indicate that the decomposition does not require any apparent barrier to produce lithium hydroxide and lithium carbonates when the reduced 1NM3 solvent molecules interact with the oxygen crossing over from the cathode. This study indicates that degradation may be more significant in the case of the 1NM3 solvent, compared to linear ethers such as tetraglyme or dioxalone, because of its relatively high electron affinity. Also, both protection of the lithium metal and prevention of oxygen crossover to the anode are essential for minimizing electrolyte and anode decomposition.

A nanostructured cathode architecture for low charge overpotential in lithium-oxygen batteries.

The lithium-oxygen battery, of much interest because of its very high-energy density, presents many challenges, one of which is a high-charge overpotential that results in large inefficiencies. Here we report a cathode architecture based on nanoscale components that results in a dramatic reduction in charge overpotential to ~0.2 V. The cathode utilizes atomic layer deposition of palladium nanoparticles on a carbon surface with an alumina coating for passivation of carbon defect sites. The low charge potential is enabled by the combination of palladium nanoparticles attached to the carbon cathode surface, a nanocrystalline form of lithium peroxide with grain boundaries, and the alumina coating preventing electrolyte decomposition on carbon. High-resolution transmission electron microscopy provides evidence for the nanocrystalline form of lithium peroxide. The new cathode material architecture provides the basis for future development of lithium-oxygen cathode materials that can be used to improve the efficiency and to extend cycle life.

Nosocomial infection surveillance in an Egyptian neonatal intensive care unit.

BACKGROUND: Nosocomial infections (NIs) have become a matter of major concern and an important cause of morbidity and mortality in neonatal intensive care units (NICUs). AIM: The objective of this study was to determine the incidence, anatomical sites and causative organisms of NI in an Egyptian NICU, and to assess the impact of NI on length of stay and mortality. METHODS: This was a descriptive hospital-based study carried out for 12 months in the NICU of the Mansoura University Children's Hospital. NI rates were calculated using different denominators (overall nosocomial infection rate, nosocomial infection incidence density, device-specific infection rates and device-days infection rates). FINDINGS: Of the 238 neonates evaluated, 49 developed 51 nosocomial infective episodes, equating to an incidence rate of 21.4% or 13.8 infections per 1000 bed-days. Pneumonia was the most frequently occurring infection (11.3%) followed by bloodstream infection (8.8%). The most frequently isolated organisms were Klebsiella spp. (33.3%) followed by Escherichia coli (21.6%). NIs were associated with prolonged hospital stay. CONCLUSION: NI is a significant problem in the Mansoura University Children's Hospital NICU. Gram-negative bacteria, especially Klebsiella spp., were the predominant causes of neonatal NI, as has been described in other studies from developing countries.

Hyphenated affinity capillary electrophoresis with a high-sensitivity cell for the simultaneous binding study of retinol and retinoic acid in nanomolars with serum albumins.

Retinol and retinoic acid are Vitamin A components that are critical for many biological processes. Both of them are strongly complexing with serum albumins giving constants of the order of 10(5)Lmol(-1) or higher. With respect to this fact, affinity capillary electrophoresis (ACE) is not applicable in its commonly used form. Therefore, for the first time, the hyphenated ACE with a high-sensitivity cell was developed and employed to investigate the binding of retinol and retinoic acid in nanomolars with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions. ACE/high-sensitivity coupled cell had contributed to fast the association and dissociation rates of the complexes in nanomolar scale of analytes ensuring the establishment of a dynamic equilibrium within a short electrophoresis time. In addition, this hyphenation led to reduce the concentrations of serum albumins as additives in background electrolyte making a sense beside the proper rinsing protocol for the negligible possibility of their adsorption. The mobility ratio based on nonlinear regression analysis was used to deduce precise binding constants of analytes with serum albumins. The binding constants (K, Lmol(-1)) of retinol were 1.28×10(5) and 5.25×10(6) and retinoic acid were 3.29×10(5) and 2.27×10(6) with HSA and BSA, respectively. The displacement and reciprocal competitive binding of analytes were investigated and indicated that retinoic acid was able to replace retinol from HSA and vice versa in the case of BSA.

Methotrexate determination in pharmaceuticals by enantioselective HPLC.

A simple, sensitive and selective high performance liquid chromatographic method with UV detection for the chiral separation of racemic methotrexate (rac-Mtx) and enantiomeric purity of L-methotrexate in pharmaceutical formulations was developed and validated. The chiral separation was optimized studying both the nature of the stationary phase by using Chirobiotic T, Chiracel OJ and human serum albumin columns and the effect of the mobile phase composition. The best results in terms of enantioresolution and enantioselectivity were achieved with a polar organic mobile phase on Chirobiotic T stationary phase. Essential steps in method validation such as precision, accuracy, suitability and stability were studied according to ICH guidelines. At wavelength 303 nm, the limit of detection (S/N=3) was found to be 0.9 microg/ml for rac-Mtx. The separation of D-Mtx at 0.2% (w/w) level (as limit of quantitation) from the main drug L-Mtx was successfully obtained with 1.72 enantioresolution value. Enantiomeric purity of L-Mtx was determined in pharmaceutical formulations (tablets and injections) with inter- and intra-days relative standard deviation < or = 1.6%. Under the validated stereoselective HPLC conditions for methotrexate, folic acid was also analysed.

Adriblastina-single stranded DNA interaction with statistical analysis.

The electrochemical behavior of adriblastina has been studied at in situ mercury film electrode (in situ MFE) and platinum electrode (PtE) in the presence of phosphoric acid as supporting electrolyte using Osteryoung square-wave stripping voltammetry (OSWSV) and cyclic voltammetry (CV). Optimal experimental and operational parameters have been selected for the drug accumulation and determination in aqueous medium. The interaction of the drug with single stranded DNA (ssDNA) has been studied and validated by using classical least square and partial least square with propagation of error. The formal potentials E degrees and E degrees ' and the equilibrium constants K(1) and K(2) have been calculated. It was found that K(2) for the oxidized form of adriblastina is 63 times than K(1) for the reduced form. Among several possible interfering metal ions, a complex formation reaction was observed between adriblastina and Cu(II) ions at in situ MFE. Cu(II) ions formed 1:2 metal:drug complex which is more stable than ssDNA-drug interaction and consequently it inhibits drug biochemical damage effects. The copper complex offers sub-nanograms determination of adriblastina in that 5.80 and 180pg/ml could be easily detected in aqueous and urine media, respectively, with R.S.D. less than 4%. F-test and t-test have been applied in urine media giving good results that indicated the high accuracy of the proposed method.

Voltammetric studies of Cu-adriblastina complex and its effect on ssDNA-adriblastina interaction at in situ mercury film electrode.

Adriblastina, a cancerostatic anthracycline antibiotic, causes considerable oxidative damage to DNA molecules. The interaction of this compound with DNA was investigated using Osteryoung square wave stripping voltammetry (OSWSV) and cyclic voltammetry (CV) at an in situ mercury film electrode. It was found that the equilibrium constant of the bonded oxidized form of the drug was 63 times bigger more important than that of the bonded reduced form. Copper forms 1 metal: 2 drug stoichiometry complex which is highly stable compared to ssDNA-drug interaction and consequently inhibited the drug biochemical damaging effects. Copper complex offered sub-nanogram determination of adriblastina in aqueous and urine media.

Osteryoung square wave stripping voltammetry at mercury film electrode for monitoring ultra trace levels of Tarabine PFS and its interaction with ssDNA.

The electrochemical oxidation and reduction behaviour of adsorbed species of antimetabolic antineoplastic agent Tarabine PFS (Cytosar-U) in Sorensen buffer solution of different pH values at an in situ-mercury film electrode (MFE) is studied using cyclic voltammetry (CV) and Osteryoung square-wave stripping voltammetry (OSWSV). Optimal experimental and operational parameters have been selected for the drug preconcentration and determination in aqueous medium. Based on the adsorption and accumulation of Tarabine PFS using Osteryoung square-wave anodic stripping voltammetry (OSWASV) at MFE, the drug is easily detected as 0.134 ng/ml (5.51 x 10(-10) M). Calibration plots have been constructed at different accumulation times. The standard deviation (n=10) at a concentration level of 6 x 10(-8) M Tarabine PFS is 0.062. The interaction of ssDNA with the drug under the optimal conditions at pH 7.7 has been studied. The formal potentials E degrees and E degrees ' and the equilibrium constants K(1) and K(2) have been calculated for the free form of Tarabine PFS and the bonded form with ssDNA, respectively. It was found that K(2) value for the bonded oxidized form is 298 times than that of K(1) for the bonded reduced form. Therefore, ssDNA has been found to interact strongly with the oxidized form of the drug. The method has been used for the nanogram determination of ssDNA with 1.9% variation coefficient. Detection limit of 3 ng/ml ssDNA has been achieved. Possible interfering organic compounds, cations and anions have been tested. The method has been applied for the drug determination in urine samples, down to 0.23 ng/ml could be easily achieved in such samples.