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Search Results: 1 - 10 of 9397 matches for " Ahmed Alhusban "
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Vascular Protection by Angiotensin Receptor Antagonism Involves Differential VEGF Expression in Both Hemispheres after Experimental Stroke
Weihua Guan, Payaningal R. Somanath, Anna Kozak, Anna Goc, Azza B. El-Remessy, Adviye Ergul, Maribeth H. Johnson, Ahmed Alhusban, Sahar Soliman, Susan C. Fagan
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0024551
Abstract: We identified that the angiotensin receptor antagonist, candesartan, has profound neurovascular protective properties when administered after ischemic stroke and was associated with a proangiogenic state at least partly explained by vascular endothelial growth factor A (VEGFA). However, the spatial distribution of vascular endothelial growth factor (VEGF) isoforms and their receptors remained unknown. Protein analysis identified a significant increase in vascular endothelial grow factor B (VEGFB) in the cerebrospinal fluid (CSF) and the ischemic hemispheres (with increased VEGF receptor 1 activation) of treated animals (p<0.05) which was co-occurring with an increase in protein kinase B (Akt) phosphorylation (p<0.05). An increase in VEGFA protein in the contralesional hemisphere corresponded to a significant increase in vascular density at seven days (p<0.01) after stroke onset. Vascular restoration by candesartan after stroke maybe related to differential regional upregulation of VEGFB and VEGFA, promoting a “prosurvival state” in the ischemic hemisphere and angiogenesis in the contralesional side, respectively. These vascular changes in both hemispheres after effective treatment are likely to contribute to enhanced recovery after stroke.
Role of Matrix Metalloproteinase Activity in the Neurovascular Protective Effects of Angiotensin Antagonism
Tauheed Ishrat,Anna Kozak,Ahmed Alhusban,Bindu Pillai,Maribeth H. Johnson,Azza B. El-Remessy,Adviye Ergul,Susan C. Fagan
Stroke Research and Treatment , 2014, DOI: 10.1155/2014/560491
Abstract: Background and Purpose. Oxidative stress and matrix metalloproteinase (MMP) activity have been identified as key mediators of early vascular damage after ischemic stroke. Somewhat surprisingly, the angiotensin II type 1 receptor (AT1) blocker, candesartan, has been shown to acutely increase MMP activity while providing neurovascular protection. We aimed to determine the contribution of MMP and nitrative stress to the effects of angiotensin blockade in experimental stroke. Methods. Wistar rats (n?=?9–14/group; a total of 99) were treated in a factorial design with candesartan 1?mg/kg IV, alone or in combination with either a peroxynitrite decomposition catalyst, FeTPPs, 30?mg/kg IP or GM6001 50?mg/kg IP (MMP inhibitor). Neurological deficit, infarct, size and hemorrhagic transformation (HT) were measured after 3?h of middle cerebral artery occlusion (MCAO) and 21?h of reperfusion. MMP activity and nitrotyrosine expression were also measured. Results. Candesartan reduced infarct size and HT when administered alone ( ) and in combination with FeTPPs ( ). GM6001 did not significantly affect HT when administered alone, but the combination with candesartan caused increased HT ( ) and worsened neurologic score ( ). Conclusions. Acute administration of candesartan reduces injury after stroke despite increasing MMP activity, likely by an antioxidant mechanism. 1. Introduction Ischemic stroke, an obstruction of blood flow in a major cerebral vessel, remains a leading cause of adult disability and death in the United States [1]. Because of its complex pathology, a major research and clinical priority is to develop therapeutic interventions in the ischemic brain through the understanding of underlying mechanisms. Ischemia reperfusion leads to a cascade of pathophysiological processes, resulting in further brain damage. Accumulations of free radicals, oxygen/nitrogen species (ROS/RNS), not only increase the susceptibility of brain tissue to reperfusion-induced damage but also trigger numerous molecular cascades, leading to increased blood-brain barrier (BBB) permeability, brain edema, hemorrhage and inflammation, and brain death [2, 3]. As an important component of free radicals, RNS, including peroxynitrite (ONOO–), play important roles in the process of cerebral ischemia-reperfusion injury. Ischemia reperfusion results in the production of peroxynitrite in ischemic brain, which triggers numerous molecular cascades and leads to vascular damage. In vitro, peroxynitrite strongly activates matrix metalloproteinases (MMPs) [4, 5]. Peroxynitrite formation on
Eff ects of ball-milling on PLGA polymer and its implication on lansoprazole-loaded nanoparticles
Anjumn Shabir,Farhan Alhusban,Afzal R. Mohammed,Yvonne Perrie
Journal of Basic and Clinical Pharmacy , 2011,
Abstract: PLGA is a biodegradable polymer utilised widely in pharmaceutical research for the encapsulation of a wide range of drugs as nano particulate systems. This study investigates the impact of rotary ball milling on the physical properties of PLGA and its influence on nanoparticle formation prepared using the solvent displacement technique.By applying mechanical stress to the polymer and altering its physical appearance and molecular weight, the loading of lansoprazole within the nanoparticles was increased to 96%, with a reduction in particle size. The results indicate that rotary ball milling significantly reduces particle size, increases lansoprazole loading and improves the release profile for lansoprazole loaded PLGA nanoparticles.
Treatment of Chronic Lateral Epicondylitis: Platelet Rich Plasma versus Extra-Corporeal Shock Wave Therapy  [PDF]
Ahmed Mohamed Ahmed Othman
Open Journal of Orthopedics (OJO) , 2014, DOI: 10.4236/ojo.2014.43013
Abstract: Background: Several treatment options have been proposed to treat lateral epicondylitis. Both Platelet rich plasma (PRP) and Extra-corporeal Shock Wave Therapy (ESWT) are new treatment modalities for tendinopathy. Patients and Methods: Thirty seven patients suffering from chronic lateral epicondylitis (tennis elbow) for at least six months were treated in this study. The patients were divided into two treatment groups, the first group including 20 patients treated by ESWT and the second group including 17 patients treated by local injection of platelet-rich plasma. The results were evaluated using the visual analogue scale and the DASH score. Results: In the first group (treated by ESWT), the average follow-up period was 21.55 months. The average VAS improved from 8.2 to 1.95 and the average DASH score improved from 72.25 to 51.7. Moreover, 11 cases were satisfied (55%), 3 cases (15%) were satisfied with reservation and 6 cases (30%) were not satisfied. In the second group (treated by PRP), the average follow-up period was 18.47 months. The average VAS improved from 8.52 to 1.47, the DASH score improved from 72 to 48.23. Concerning patient satisfaction, 13 cases were satisfied (83.33%), 3 cases (10.52%) were satisfied with reservation and 1 case (5.55%) was not satisfied. Conclusion: Platelet rich plasma was proved to achieve superior results when compared to ESWT as regards pain relief, improvement of elbow function and patient satisfaction at follow-up.
Open versus Arthroscopic Treatment of Post-Traumatic Stiff Elbow  [PDF]
Ahmed Mohamed Ahmed Othman
Open Journal of Orthopedics (OJO) , 2014, DOI: 10.4236/ojo.2014.411047
Abstract: Thirty three patients with post-traumatic stiff elbow were divided into two groups. The first group included 18 patients with an average age of 31.05 years treated by open arthrolysis. The second included 15 patients with an average age of 31.66 years treated by arthroscopic method. The results were evaluated using the Mayo clinic score and DASH score for elbow function. In the open group, after an average period of follow-up 19.33 months, the average range of flexion-extension movement improved from 51.11° to 103.94°. The average Mayo clinic score improved from 63.38 to 92.83 and the average DASH score improved from 68.1 to 40.23. There were 13 cases (72.22%) excellent, 4 cases (22.22%) good and 1 case (5.55%) with the poor result. In the arthroscopic group, after an average period of follow-up 17.73 months, the average range of flexion-extension movement improved from 59.46° to 101.53°. The average Mayo clinic score improved from 62.93 to 92.73 and the average DASH score improved from 69.25 to 46.4. There were 10 cases (66.66%) excellent, 3 cases (20%) good and 2 cases (13.33%) with the poor result. Both open and arthro-scopic treatment can be effective in treatment of post-traumatic stiff elbow. Arthroscopic treatment is associated with less post-operative pain and morbidity. However, open treatment provides better range of motion and marked improvement of elbow function.
Energy-Efficient and Reliable Transport Protocols for Wireless Sensor Networks: State-of-Art  [PDF]
Ahmed Ayadi
Wireless Sensor Network (WSN) , 2011, DOI: 10.4236/wsn.2011.33011
Abstract: New wireless sensor network applications (e.g., military surveillance) require higher reliability than a simple best effort service could provide. Classical reliable transport protocols like Transmission Control Protocol (TCP) are not well suited for wireless sensor networks due to both the characteristics of the network nodes (low computing power, strong energy constraints) and those of the main applications running on those nodes (low data rates). Recent researches present new transport protocols for wireless sensor networks providing various type of reliability and using new mechanisms for loss detection and recovery, and congestion control. This paper presents a survey on reliable transport protocol for WSNs.
Modular Spaces Topology  [PDF]
Ahmed Hajji
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.49175
Abstract:

In this paper, we present and discuss the topology of modular spaces using the filter base and we then characterize closed subsets as well as its regularity.

Acquisition of the Inter-Dental Fricatives /θ/ and /ð/ in ESL/EFL and Jamaican Creole: A Comparative Study  [PDF]
Ahmed Mousa
Open Journal of Modern Linguistics (OJML) , 2014, DOI: 10.4236/ojml.2014.41004
Abstract:

This study aims at investigating to what extent the linguistic processes exhibited in creolization parallel those manifested by Arab learners of English in particular and those of child language and second/foreign language in general. Another aim of the study is to highlight the link between second/foreign language learning and historical change. To this end, the speech of two speakers of the Broad Jamaican Creole was compared with the performance of Saudi school and university learners of English as a foreign language and data from child language, with respect to the pronunciation of English inter-dental fricatives /θ/ and /e/. The results show that learning in the above three situations takes place according to the same principles. Furthermore, the sound substitutions made in the three situations (i.e. [t], [d] respectively) are the same as those witnessed in historical sound change.

Does FDI Crowd in or out Domestic Investment? New Evidence from Emerging Economies  [PDF]
Ahmed Kamaly
Modern Economy (ME) , 2014, DOI: 10.4236/me.2014.54038
Abstract: Foreign direct investment (FDI) has been for a while now an acronym associated with improvement in competitiveness and economic growth. To assess the expediency of FDI, it is imperative to answer the following question: what is the dynamic effect of FDI on total investment? In other words, what is the effect of FDI on domestic investment (DI); does it crowd in or out domestic investment? Research addressing this question is relatively recent and its empirical findings are ambiguous. This paper attempts to dodge the pitfalls in the theoretical and especially the empirical literature in assessing the link between FDI and domestic investment. The paper develops a simple theoretical model which is commonly used in the literature to come up with a reduced-form equation. Using data on 16 emerging countries over a 30-year period, the empirical model is estimated as a system of equations where each equation represents a country. Grouping all individual country regression in one system of equations aims to take into account the common contemporaneous errors associated with global shocks affecting FDI flows. This system of equations is estimated using 3SLS to account for both the existence of contemporaneous errors among individual country equations as well as the endogeneity of FDI. Results show that in general the effect of FDI on DI is country specific; however, in most countries, on impact, FDI has a positive and significant effect on DI. In subsequent periods, FDI may crowd out DI. In most countries included in the sample, FDI has a neutral long-term effect on DI. Crowding in or crowding out effect of FDI on DI is only found in few countries. This indicates that the rule is the neutrality of FDI on DI and the exception is otherwise (whether crowding in or out).
Assessment and Evaluation of Band Ratios, Brovey and HSV Techniques for Lithologic Discrimination and Mapping Using Landsat ETM+ and SPOT-5 Data  [PDF]
Ahmed Madani
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.51002
Abstract:

This study aims to assess and to evaluate band ratios, brovey and HSV (Hue-Saturation-Value) techniques for discrimination and mapping the basement rock units exposed at Wadi Bulghah area, Saudi Arabia using multispectral Landsat ETM+ and SPOT-5 panchromatic data. FieldSpec instrument is utilized to collect the spectral data of diorite, marble, gossan and volcanics, the main rock units exposed at the study area. Spectral profile of diorite exhibits very distinguished absorption features around 2.20 μm and 2.35 μm wavelength regions. These absorption features lead to lowering the band ratio values within the band-7 wavelength region. Diorite intrusions appear to have grey and dark grey image signatures on 7/3 and 7/2 band ratio images respectively. On the false color composite ratio image (7/3:R; 7/2:G and 5/2:B), diorite, marble, gossan and volcanics have very dark brown, dark blue, white and yellowish brown image signatures respectively. Image fusion between previously mentioned FCC ratio image and high spatial resolution (5 meters) SPOT-5 panchromatic image is carried out by using brovey and HSV transformation

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