1,846 research outputs found
Leukotrienes and leukotriene modifiers in pediatric allergic diseases
Leukotrienes are potent pro-inflammatory lipid mediators derived from arachidonic acid through several enzymatic pathways. They have an essential role in allergic inflammation, where they induce bronchoconstriction, airway edema, and chemotaxis of the inflammatory cells in the airways, nasal and conjunctival tissues. Leukotriene modifiers include leukotriene receptor antagonists (montelukast, zafirlukast and pranlukast) and leukotriene synthesis inhibitors (zileuton). These medications have been extensively used in childhood allergic diseases. This review will highlight the leukotriene pathway and its role in allergy as well as the effects of leukotriene modifiers in different allergic disorders
Electron dynamics in gold and gold–silver alloy nanoparticles: The influence of a nonequilibrium electron distribution and the size dependence of the electron–phonon relaxation
©1999 American Institute of Physics. The electronic version of this article is the complete one and can be found online at: http://link.aip.org/link/?JCPSA6/111/1255/1DOI: 10.1063/1.479310Electron dynamics in gold nanoparticles with an average diameter between 9 and 48 nm have been studied by femtosecond transient absorption spectroscopy. Following the plasmon bleach recovery after low power excitation indicates that a non-Fermi electron distribution thermalizes by electron–electron relaxation on a time scale of 500 fs to a Fermi distribution. This effect is only observed at low excitation power and when the electron distribution is perturbed by mixing with the intraband transitions within the conduction band (i.e., when the excitation wavelength is 630 or 800 nm). However, exciting the interband transitions at 400 nm does not allow following the early electron thermalization process. Electron thermalization with the lattice of the nanoparticle by electron–phonon interactions occurs within 1.7 ps under these conditions, independent of the excitation wavelength. In agreement with the experiments, simulations of the optical response arising from thermalized and nonthermalized electron distributions show that a non-Fermi electron distribution leads to a less intense bleach of the plasmon absorption. Furthermore, the difference between the response from the two electron distributions is greater for small temperature changes of the electron gas (low excitation powers). No size dependence of the electron thermalization dynamics is observed for gold nanoparticles with diameters between 9 and 48 nm. High-resolution transmission electron microscopy (HRTEM) reveals that these gold nanoparticles possess defect structures. The effect of this on the electron–phonon relaxation processes is discussed. 18 nm gold–silver alloy nanoparticles with a gold mole fraction of 0.8 are compared to 15 nm gold nanoparticles. While mixing silver leads to a blue-shift of the plasmon absorption in the ground-state absorption spectrum, no difference is observed in the femtosecond dynamics of the system
Serum transforming growth factor-beta1 in asthmatic children
Background: Transforming growth factor-beta1 is a multifunctional cytokine which has been linked to the pathogenesis of subepithelial fibrosis and airway wall remodeling in bronchial asthma. Objective: To outline the changes in serum TGF-beta1 in children with bronchial asthma in relation to severity of asthma and different treatment modalities. Methods: Twenty-three children with bronchial asthma recruited from the Pediatric Allergy and Immunology Clinic of Ain Shams University Children’s Hospital were enrolled in the study as well as 29 healthy controls. Asthmatic children were classified according to severity into two groups; the mild asthma group which included 12 children, 4 with mild intermittent and 8 with mild persistent asthma (none received steroid therapy), and the severe persistent asthma group which included 11 children (all were on steroid therapy). All patients were subjected to clinical evaluation and laboratory investigations including absolute eosinophilic count (AEC), total serum IgE% and biologically active serum TGF-beta1 by ELISA technique. All patients were studied during acute asthma exacerbations. Reevaluation during steady state asthma was carried out for 8 patients with mild persistent asthma and 9 with severe persistent asthma. Results: During acute asthma exacerbations, the mean serum TGF-beta1 was significantly elevated in mild asthma (77.04 ± 57.04 ng/ml) compared to controls (21.81 ± 22.09 ng/ml). However for severe persistent asthma , the mean serum TGF-beta1 was significantly lower (4.23 ± 0.85 ng/ml) than in controls. Comparison of paired observations of serum TGF-beta1 revealed a significant drop, during steady state, in patients with mild asthma, whereas in severe asthma, a significant rise was observed. The levels of both asthma groups during steady state were comparable to the control values. A positive correlation, of borderline significance, between serum TGF-beta1 and total serum IgE% was observed among mild asthamtics during acute exacerbations (r = 0.55). Conclusion: The behavior of serum TGF-beta1 in acute asthma exacerbations depends on asthma severity and is perhaps related to steroid inhalation therapy. The tendency towards normality of serum TGF-beta1 in steady state asthma is possibly a good prognostic sign.Keywords: TGF-beta1, bronchial asthma, children, remodelingEgypt J Pediatr Allergy Immunol 2004; 2(1): 46-5
Geophysical investigations of a geothermal anomaly at Wadi Ghadir, eastern Egypt
During regional heat flow studies a geothermal anomaly was discovered approximately 2 km from the Red Sea coast at Wadi Ghadir, in the Red Sea Hills of Eastern Egypt. A temperature gradient of 55 C/km was measured in a 150 m drillhole at this location, indicating a heat flow of approximately 175 mw/sqm, approximately four times the regional background heat flow for Egypt. Gravity and magnetic data were collected along Wadi Ghadir, and combined with offshore gravity data, to investigate the source of the thermal anomaly. Magnetic anomalies in the profile do not coincide with the thermal anomaly, but were observed to correlate with outcrops of basic rocks. Other regional heat flow and gravity data indicate that the transition from continental to oceanic type lithosphere occurs close to the Red Sea margin, and that the regional thermal anomaly is possibly related to the formation of the Red Sea
Circulating dendritic cells in pediatric patients with nephrotic syndrome
Background: Dendritic cells (DCs) represent one of the most extensively studied topics in immunology, because of their central role in the induction and regulation of adaptive immunity, and because of their therapeutic potential for manipulating immune responses. Objectives: To evaluate circulating DC levels in pediatric patients with idiopathic nephrotic syndrome (NS) and its relation to disease activity in these patients. Methods: Fifteen nephrotic patients in relapse (proteinuria>40mg/m2/hour, hypoalbuminemia, and edema) before initiating steroid therapy (Group I), and another15 nephrotic patients in remission after withdrawal of steroid therapy (Group II) were compared to 15 age- and sex- matched healthy children. Besides clinical evaluation and routine laboratory investigations of nephrotic syndrome, circulating DCs were measured by flowcytometry. Results: Circulating DC count was lower in nephrotic patients in both proteinuria and remission groups [(48.89±13.52) and (64.64±7.69) X106/liter respectively] than in the control group (78.54±9.8) X106/liter with highly significant statistical difference (p < 0.001), and lower in proteinuria group than the remission group with highly significant statistical difference (p < 0.001). There was a positive correlation between DC count and serum albumin (moderate association) (p=0.002) and a negative correlation between DC count and urine protein /creatinine ratio (strong association) (p=0.001). Conclusion: Nephrotic syndrome was associated with decreased number of circulating DCs and the decrease was more apparent in patients with active disease. The positive correlation between DC counts and total protein, and serum albumin, and the negative correlation between DC count and urine protein/creatinine ratio point to the link between the decrease in DC count and the severity of the disease process.Keywords: Denderitic cells, nephrotic syndrome, immune deficiencyEgypt J Pediatr Allergy Immunol 2011;9(1):41-4
The Level of Ischemic Modified Albumin (IMA) as Risk Marker for Cardio Vascular D isease (CVD) among some diabetic patients (type II) in Khartoum state -Sudan
Background. Recent literature reports show large interest in ischemic modified albumin (IMA) biochemical marker for detection of myocardial injury. Special attention is focused in estimation of IMA test for the diagnosis and evaluation of myocardial ischemia as well as others acute coronary syndrome in emergency patients.Objective : evaluation of ischemia-modified albumin (IMA) in well controlled and uncontrolled patients with type 2 diabetes mellitus and estimation of its connection with cardiovascular disease.Measurement thelevelof IMA asrisk marker forcardio vascular disease (CVD) in diabetic patients that arrivedtoemergency department with signs and symptoms of CVD.Methodology. 140 subjects enrolled in thisstudy ,70 diabetes mellitus patients with signs and symptoms of CVD, and other 70 apparently non diabetic healthy subjects' as controls, , the levels of biomarker IMA was measured as the risk marker ofCVDin controlled and uncontrolleddiabeticpatients with type2,the Diagnostic potential was evaluated by receiver operating characteristic analysis and their relationships were analyzed. This study was donein Shab Hospital, Khartoum.Period from 1st of February 2015 to October 2015.Results: The results showed that CVD were predominant among diabetic female 57 % and peaked at age 75.5 years among 40-75 year old. The IMA was significantly increase in diabetic patients when compare with normal healthy group with cut off value ( 0.97 IU/L ), and there is also significantly increase in IMA level in uncontrolled diabetic patients (Mean ± SD; 14.70 + 10.66) that presented with acute chest pain and havea signs and symptoms of cardiac ischemia when compared with the well-controlled diabetic patients(Mean ± SD; 3.74 + 3.68). controlled and uncontrolled diabetic patients were determined by the level of their HBA1c and comparison with the means of IMA level in their serum.Conclusions: increase IMA level in poor control and long stand diabetic patients could help to identify the higher risk for develop to CVD, and The most common complication such as suffering from local or systemic hypoxic conditions, as acute ischemic stroke, peripheral vascular disease.Keywords: Ischemia, Type 2 diabetes mellitus, cardiovascular disease, Ischemic Modified Albumi
The level of Ischemic Modified Albumin (IMA) as risk marker for Cardio Vascular Disease (CVD) among some diabetic patients (type II) in Khartoum State-Sudan
Background: Recent literature reports show large interest in ischemic modified albumin (IMA) biochemical marker for detection of myocardial injury. Special attention is focused in estimation of IMA test for the diagnosis and evaluation of myocardial ischemia as well as others acute coronary syndrome in emergencypatients.Objective: evaluation of ischemia-modified albumin (IMA) in well controlled and uncontrolled patients with type 2 diabetes mellitus and estimation of its connection with cardiovascular disease.Measurement the levelof IMA as risk marker for cardio vascular disease (CVD) in diabetic patients that arrived to emergency department with signs and symptoms of CVD.Methodology: 140 subjects enrolled in this study ,70 diabetes mellitus patients with signs and symptoms of CVD, and other 70 apparently non diabetic healthy subjects’ as controls, , the levels of biomarker IMA was measured as the risk marker of CVDin controlled and uncontrolled diabeticpatients with type2,the Diagnostic potential was evaluated by receiver operating characteristic analysis and their relationships were analyzed. This study was done in Shab Hospital, Khartoum. Period from 1st of February 2015 to October 2015.Results: The results showed that CVD were predominant among diabetic female 57 % and peaked at age 75.5 years among 40-75 year old. The IMA was significantly increase in diabetic patients when compare with normal healthy group with cut off value ( 0.97 IU/L ), and there is also significantly increase in IMA level in uncontrolled diabetic patients (Mean ± SD; 14.70 + 10.66) that presented with acute chest pain and havea signs and symptoms of cardiac ischemia when compared with the wellcontrolled diabetic patients (Mean ± SD; 3.74 ± 3.68). controlled and uncontrolled diabetic patients were determined by the level of their HBA1c and comparison with the means of IMA level in their serum.Conclusions: increase IMA level in poor control and long stand diabetic patients could help to identify the higher risk for develop to CVD, and The most common complication such as suffering from local or systemic hypoxic conditions, as acute ischemic stroke, peripheral vascular disease.Keywords: Ischemia, Type 2 diabetes mellitus, cardiovascular disease, Ischemic Modified Albumi
EVALUATION OF GROUNDWATER QUALITY OF SIWA OASIS
In discussing the water quality evaluation for use in different purposes, the author will briefly examine some of the major important water quality standards. These standards serve as a basis for appraisal of the results of chemical water analysis in terms of suitability of the water for various intended uses. According to total dissolved salts (TDS), major ions as cations ( Ca2+, Mg2+, Na+, K+), anions (CO₃2â», HCO₃â»Â ,SOâ‚„2â», Clâ»), with some heavy metals such as Al3+, B3+ , Cd2+, Co2+, Cr3+, Cu2+, Fe3+, Mn2+, Mo2+, Ni2+, Pb2+, Sr2+, V2+  and Zn2+  The results indicate that the samples of Nubian sandstone aquifer is suitable for drinking of human and livestock , suitable for laundry purposes and for irrigation. While the samples of Fractured dolomite limestone aquifer are unsuitable for drinking and irrigation.Â
A New Inverse Rayleigh Distribution with Applications of COVID-19 Data: Properties, Estimation Methods and Censored Sample
This paper aims at modelling the COVID-19 spread in the United Kingdom and the United States of America, by specifying an optimal statistical univariate model. A new lifetime distribution with three-parameters is introduced by a combination of inverse Rayleigh distribution and odd Weibull family of distributions to formulate the odd Weibull inverse Rayleigh (OWIR) distribution. Some of the mathematical properties of the OWIR distribution are discussed as linear representation, quantile, moments, function of moment production, hazard rate, stress-strength reliability, and order statistics. Maximum likelihood, maximum product spacing, and Bayesian estimation method are applied to estimate the unknown parameters of OWIR distribution. The parameters of the OWIR distribution are estimated under the progressive type-II censoring scheme with random removal. A numerical result of a Monte Carlo simulation is obtained to assess the use of estimation methods
A New Inverse Rayleigh Distribution with Applications of COVID-19 Data: Properties, Estimation Methods and Censored Sample
This paper aims at modelling the COVID-19 spread in the United Kingdom and the United States of America, by specifying an optimal statistical univariate model. A new lifetime distribution with three-parameters is introduced by a combination of inverse Rayleigh distribution and odd Weibull family of distributions to formulate the odd Weibull inverse Rayleigh (OWIR) distribution. Some of the mathematical properties of the OWIR distribution are discussed as linear representation, quantile, moments, function of moment production, hazard rate, stress-strength reliability, and order statistics. Maximum likelihood, maximum product spacing, and Bayesian estimation method are applied to estimate the unknown parameters of OWIR distribution. The parameters of the OWIR distribution are estimated under the progressive type-II censoring scheme with random removal. A numerical result of a Monte Carlo simulation is obtained to assess the use of estimation methods
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