Brain abscess following rituximab infusion in a patient with pemphigus vulgaris.

BackgroundImmunocompromised patients are at increased risk for developing meningitis or, rarely, brain abscess with opportunistic organisms like Listeria monocytogenes.Case reportA 52 year-old Saudi Arabian woman who was diagnosed with pemphigus vulgaris and diabetes and had been on prednisolone and azathioprine for about 4 years. She presented with headache, low-grade fever, and left-sided weakness 2 weeks after receiving the second dose of rituximab infusion. Magnetic resonance imaging revealed an enhanced space-occupying lesion with multiple small cyst-like structures and vasogenic edema in the right temporoparietal area. Her blood culture was positive for Listeria monocytogenes, and a brain biopsy showed necrotic tissues with pus and inflammatory cells. She recovered after a 6-week course of antibiotics with ampicillin and gentamycin.ConclusionsBrain abscess due to Listeria monocytogenes is a risk that should be considered when adding rituximab to the regimen of a patient who is already Immunocompromised

Dual-wave β-correction spectrophotometric determination of palladium ions using neothorin

AbstractA simple low cost method has been developed and validated for the determination of trace amounts of palladium (II) ions in water and fertilizer samples. The method is based on the reaction of palladium (II) ions with the reagent neothorin (2-(2-arsonophenylazo) chromotropic acid disodium salt). The complex formed exhibits an absorption maximum at 567nm (λmax) in Britton–Robinson (BR) buffer (pH=2). The corrected absorbance of the formed complex at λmax was obtained by employing a β-correction spectrophotometric method. The Beer–Lambert law and Ringbom's plots of the coloured palladium reagent complex were obeyed in the concentration ranges of 0.05–2.7 and 0.1–2μgmL−1 palladium (II) ions, respectively, with relative standard deviations in the range of ±1.3–2.1%. The limits of detection (LOD) and quantitation (LOQ) of the procedure were 0.011 and 0.04μgmL−1 palladium, respectively. The proposed method was applied for the analysis of palladium (II) ions in spiked tap, mineral and underground water samples. The results of the developed method were satisfactorily compared with the data obtained by the inductively coupled plasma-mass spectrometric (ICP-MS) method. Statistical comparison of the results of the proposed method with those obtained by the standard method revealed no significant differences in accuracy and precision. The developed method offers a simple system coupled with good reproducibility, accuracy, ruggedness and cost effectiveness

Statistical Analysis of a Linear Multi-Step Numerical Treatment

The aim of this paper is to compare the relative accuracies between predictor-corrector methods, Adams-Bashforth method and Adams-Moulton method for solving initial value Differential Equations numerically to observe which methods tend to function well in which step-size brackets as well as which ones provide the minimum amount of error when compared to the true value. The statistical analysis shows that there is always a small amount of error present using Heun’s method; however, the error is rarely large enough unless the function is rapidly rising

Different chemical behaviors and antioxidant activity of three novel schiff bases containing hydroxyl groups. X-ray structure of CH2{cyclo-C6H10-NH=CH-(2-O-naphth)}2.H2O

The antioxidant activities of three new Schiff base compounds, 1–3, were studied through their direct scavenging ability to eliminate free radicals using DPPH and ABTS methods and also through their indirect antioxidant activity as measured using the ferric thiocyanate (FTC) method. The number of OH groups in the compounds and their positions play a role in the activity. The crystal structure of CH2{cycloC6H10NHCH-(2-O-naphth)}2.H2O (1), has been determined and proves the existence of intramolecular hydrogen-bonds and hydrogen-bonded water molecules and reveals the keto-amine (NH⋯O) tautomer of this compound. One cyclo-hexyl ring was found to be disordered, and was resolved in two orientations. Hydrogen atoms of the NHCH groups were located in difference maps and were refined freely. Compounds 2 and 3 exhibit the enol-imine form. The UV–vis spectra of the three compounds have been studied in organic solvents of different polarity, and in basic and acidic media, and were found helpful in understanding the tautomeric forms in these compounds; the polarity was modified by adding (CF3COOH) or [(C2H5)3N] to the solvent. All three compounds have been characterized by elemental analysis, UV–vis, FTIR, NMR and MS

On Estimating a Constant Stress Life Test Model Using Time-Censored Data from the Linear Failure Rate Distribution

In this paper, a constant stress partially accelerated life test model is considered and investigated using type-I censored data from the linear failure rate distribution. The maximum likelihood estimates (point and interval) of the distribution parameters and the acceleration factor are obtained. For accuracy reasons, the mean squared errors are calculated using different sizes of samples. For illustration, Monte Carlo simulation studies are presented.Предложена модель частично ускоренных испытаний на циклическую долговечность с постоянным напряжением с использованием данных, подвергнутых цензурированию типа I с линейным распределением скорости разрушения. Получены точечные и интервальные оценки максимального правдоподобия параметров распределения и коэффициента ускорения. С целью повышения точности прогнозов расчет среднеквадратических погрешностей осуществлялся для образцов разных размеров. Для иллюстрации работоспособности модели выполнено моделирование тестовых задач с использованием метода Монте-Карло.Запропоновано модель частково прискорених випробувань на циклічну довговічність з постійною напругою з використанням даних, які було піддано цензуруванню типу I із лінійним розподілом швидкості руйнування. Отримано точкові й інтервальні оцінки максимальної правдоподібності параметрів розподілу і коефіцієнта прискорення. Із метою підвищення точності прогнозів розрахунок середньоквадратичних похибок проводився для зразків різних розмірів. Для ілюстрації роботоздатності моделі виконано моделювання тестових задач із використанням методу Монте-Карло

Human-Induced Geo-Hazards in the Kingdom of Saudi Arabia: Distribution, Investigation, Causes and Impacts

Different types of geological hazards are induced by human activities in the Kingdom of Saudi Arabia (KSA). These geological hazards include land subsidence and earth fissures, sinkholes, expansive soils, and flash floods. A wide variety of recent geological hazards have been reported in several areas, causing significant human and property losses. Human activities, most notably groundwater extraction, infrastructure development, and agricultural activities, have induced unstable conditions. This chapter provides an overview of the human-induced geological hazard in the KSA, mainly earth fissures and sinkhole, which represent a scarcely explored topic. This work identifies the main types of human-induced geological-hazard formations, distribution, causes, and impacts, illustrated through several case studies in the KSA

Evaluation of Saudi International Educational Programs using Rossi and His Colleagues Evaluation Model

This study aimed to evaluate international educational programs (IEP) of the Saudi private schools, their need, design, inputs, processes, outputs and impact using the hierarchical evaluation model (HEM) of Rossi and his colleagues. The methodology adopts dual quantitative and qualitative methods. The evaluation includes Saudi private schools applying such programs, and samples of some foreign schools and foreign community schools employing deep comparisons, questionnaires, field observations and interviews of administrators, teachers, students and parents. This evaluation shows that HEM helped in grading evaluation and determining questions that suit program grade. Results show that IEP maintain students’ identity, and achieve outcomes reasonably. They reduced student enrollment in foreign programs, and helped raise their knowledge, language, personal and educational skills to a global level. However, there is lack of clear program theory that identifies inputs, processes and outcomes, lack of clarity in program mechanisms, design, needs assessment, performance monitoring and evaluation. They show limited external evaluation, with no standardized or uniform standards for teachers selection and intake as well as final achievement exams. They likewise show lack of information for parents and community members. This study recommends the expansion of experience provided that international standards of programs quality and monitoring be ensured

A novel homozygous TPM1 mutation in familial pediatric hypertrophic cardiomyopathy and in silico screening of potential targeting drugs.

Familial hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease. While sarcomeric gene mutations explain many HCM cases, the genetic basis of about half of HCM cases remains elusive. Here we aimed to identify the gene causing HCM in a non-consanguineous Saudi Arabian family with affected family members and a history of sudden death. The impact of the identified mutation on protein structure and potential drug targets were evaluated in silico. Triplets (two HCM subjects and one patent ductus arteriosus (PDA) case) and unaffected parents were screened by targeted next-generation sequencing (NGS) for 181 candidate cardiomyopathy genes. In silico structural and functional analyses, including protein modeling, structure prediction, drug screening, drug binding, and dynamic simulations were performed to explore the potential pathogenicity of the variant and to identify candidate drugs. A homozygous missense mutation in exon 1 of TMP1 (assembly GRCh37-chr15: 63340781; G>A) was identified in the triplets [two HCM and one patent ductus arteriosus (PDA)] that substituted glycine for arginine at codon 3 (p.Gly3Arg). The parents were heterozygous for the variant. The mutation was predicted to cause a significant and deleterious change in the TPM1 protein structure that slightly affected drug binding, stability, and conformation. In addition, we identified several putative TPM1-targeting drugs through structure-based in silico screening. TPM1 mutations are a common cause of HCM and other congenital heart defects. To date, TPM1 has not been associated with isolated PDA; to our knowledge, this is the first report of the homozygous missense variation p.Gly3Arg in TPM1 associated with familial autosomal recessive pediatric HCM and PDA. The identified candidate TPM1 inhibitors warrant further prospective investigation.This research was supported by the Strategic Technologies Programs of the National Plan for Science, Technology and Innovation (MAARIFAH), Kingdom of Saudi Arabia. Project No: 12-MED3174-05, through the Science and Technology Unit (STU), Taibah University, Al Madinah Al Munawwarah, Kingdom of Saudi Arabia

Sequence analysis of the VSX1 and SOD1 genes in families with Keratoconus and a review of the literature

AbstractObjectiveKeratoconus (KC) is a non-inflammatory disorder of the cornea in which the cornea becomes thin and conical, inducing myopia and irregular astigmatism and resulting in mild to marked impairment of vision. The present study was designed to screen two candidate KC genes to identify pathogenic sequence variants responsible for KC in Saudi families.MethodsPeripheral blood samples from members of five Saudi families with KC from the Northern region were collected. Genomic DNA was isolated, and bidirectional sequencing was performed of all coding exons of VSX1 and SOD1 genes using Sanger sequencing.ResultsAll five of the KC families showed a pattern of autosomal recessive inheritance. Phenotyping of these families was performed by a senior ophthalmologist. Sequence analysis of the VSX1 and SOD1 genes failed to reveal any pathogenic sequence variant that could account for KC in the affected individuals.ConclusionOur failure to detect sequence variants in two of the known KC associated genes triggers an interest in other known KC candidate genes, including miR-184, DOCK9, IL1RN and SLC4A11. Future genotyping with dense SNP arrays followed by exome sequencing in these families will be a useful approach to identify the gene(s) underlying KC in this Saudi cohort, which may be different from those reported elsewhere