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Search Results: 1 - 10 of 151929 matches for " Adel K. El-Naggar "
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Enhanced MDM2 Oncoprotein Expression in Soft Tissue Sarcoma: Several Possible Regulatory Mechanisms
Raphael E. Pollock,Aiquing Lang,Adel K. El-Naggar,Robert Radinsky
Sarcoma , 1997, DOI: 10.1080/13577149778443
Abstract:
Mitochondrial Mutations in Adenoid Cystic Carcinoma of the Salivary Glands
Suhail K. Mithani,Chunbo Shao,Marietta Tan,Ian M. Smith,Joseph A. Califano,Adel K. El-Naggar,Patrick K. Ha
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0008493
Abstract: The MitoChip v2.0 resequencing array is an array-based technique allowing for accurate and complete sequencing of the mitochondrial genome. No studies have investigated mitochondrial mutation in salivary gland adenoid cystic carcinomas.
MicroRNA Profiling of Salivary Adenoid Cystic Carcinoma: Association of miR-17-92 Upregulation with Poor Outcome
Yoshitsugu Mitani, Dianna B. Roberts, Hanadi Fatani, Randal S. Weber, Merrill S. Kies, Scott M. Lippman, Adel K. El-Naggar
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066778
Abstract: Background Salivary adenoid cystic carcinoma (ACC) is a rare relentlessly progressive malignant tumor. The molecular events associated with ACC tumorigenesis are poorly understood. Variable microRNAs (miRNA) have been correlated with tumorigenesis of several solid tumors but not in ACC. To investigate the association of miRNAs with the development and/or progression of ACC, we performed a comparative analysis of primary ACC specimens and matched normal samples and a pooled salivary gland standard and correlated the results with clinicopathologic factors and validated selected miRNAs in a separate set of 30 tumors. Methods MiRNA array platform was used for the identification of target miRNAs and the data was subjected to informatics and statistical interrelations. The results were also collected with the MYB-NFIB fusion status and the clinicopathologic features. Results Differentially dysregulated miRNAs in ACC were characterized in comparison to normal expression. No significant differences in miRNA expression were found between the MYB-NFIB fusion positive and -negative ACCs. Of the highly dysregulated miRNA in ACC, overexpression of the miR-17 and miR-20a were significantly associated with poor outcome in the screening and validation sets. Conclusion Our study indicates that the upregulation of miR-17-92 may play a role in the biology of ACC and could be potentially targeted in future therapeutic studies.
DEAR1 Is a Dominant Regulator of Acinar Morphogenesis and an Independent Predictor of Local Recurrence-Free Survival in Early-Onset Breast Cancer
Steven T. Lott,Nanyue Chen,Dawn S. Chandler,Qifeng Yang,Luo Wang,Marivonne Rodriguez,Hongyan Xie,Seetharaman Balasenthil,Thomas A. Buchholz,Aysegul A. Sahin,Katrina Chaung,Baili Zhang,Shodimu-Emmanu Olufemi,Jinyun Chen,Henry Adams,Vimla Band,Adel K. El-Naggar,Marsha L. Frazier,Khandan Keyomarsi,Kelly K. Hunt,Subrata Sen,Bruce Haffty,Stephen M. Hewitt,Ralf Krahe,Ann McNeill Killary
PLOS Medicine , 2009, DOI: 10.1371/journal.pmed.1000068
Abstract: Background Breast cancer in young women tends to have a natural history of aggressive disease for which rates of recurrence are higher than in breast cancers detected later in life. Little is known about the genetic pathways that underlie early-onset breast cancer. Here we report the discovery of DEAR1 (ductal epithelium–associated RING Chromosome 1), a novel gene encoding a member of the TRIM (tripartite motif) subfamily of RING finger proteins, and provide evidence for its role as a dominant regulator of acinar morphogenesis in the mammary gland and as an independent predictor of local recurrence-free survival in early-onset breast cancer. Methods and Findings Suppression subtractive hybridization identified DEAR1 as a novel gene mapping to a region of high-frequency loss of heterozygosity (LOH) in a number of histologically diverse human cancers within Chromosome 1p35.1. In the breast epithelium, DEAR1 expression is limited to the ductal and glandular epithelium and is down-regulated in transition to ductal carcinoma in situ (DCIS), an early histologic stage in breast tumorigenesis. DEAR1 missense mutations and homozygous deletion (HD) were discovered in breast cancer cell lines and tumor samples. Introduction of the DEAR1 wild type and not the missense mutant alleles to complement a mutation in a breast cancer cell line, derived from a 36-year-old female with invasive breast cancer, initiated acinar morphogenesis in three-dimensional (3D) basement membrane culture and restored tissue architecture reminiscent of normal acinar structures in the mammary gland in vivo. Stable knockdown of DEAR1 in immortalized human mammary epithelial cells (HMECs) recapitulated the growth in 3D culture of breast cancer cell lines containing mutated DEAR1, in that shDEAR1 clones demonstrated disruption of tissue architecture, loss of apical basal polarity, diffuse apoptosis, and failure of lumen formation. Furthermore, immunohistochemical staining of a tissue microarray from a cohort of 123 young female breast cancer patients with a 20-year follow-up indicated that in early-onset breast cancer, DEAR1 expression serves as an independent predictor of local recurrence-free survival and correlates significantly with strong family history of breast cancer and the triple-negative phenotype (ER?, PR?, HER-2?) of breast cancers with poor prognosis. Conclusions Our data provide compelling evidence for the genetic alteration and loss of expression of DEAR1 in breast cancer, for the functional role of DEAR1 in the dominant regulation of acinar morphogenesis in 3D culture, and for
Surgery of Craniocervical Meningiomas
A El-Naggar
Alexandria Journal of Medicine , 2010,
Abstract: Objective: To study the different surgical approaches to craniocervical meningiomas in different locations in the area of the foramen magnum, whether anterior, posterior, antrolateral or posterolateral Methods: Twenty six patients with craniocervical meningiomas were operated upon during the period from 2000 to 2009 using the standard posterior approach for posterior lesions (14 cases), extreme lateral approach without drilling of the occipital condyle in the antrolateral and posterolateral lesions(6 cases) and transcondylar approach for anterior lesions (6 cases). Results: This study included 16 females and 10 males, the patients’ age ranged from 23 to 64 years with a mean of 51.8 years. Tumor size ranged from2 to 6.4 in its maximum diameter. Tumor location was posterior in 14 patients, lateral in 6 patients and anterior in 6 patients. Total tumor resection was done in 23 (88.4%) patients and subtotal in 3 (11.6%) patients. Postoperative complications included transient lower cranial nerves affection, transient hemiparesis. There was no mortality in this study. The follow up period ranged from 6 months to 4.8 years. Conclusion: Surgical approach to craniocervical meningioma has to be tailored according to the location of the tumor. Posterior tumors are safely totally removed through the slandered suboccipital approach. Posterolateral and antrolateral tumors are easily removed via the postero lateral retrocondylar approach without drilling of the occipital condyle benefiting from the working space given by lateral displacement of the brain stem. Anteriorly located tumors are better approached through the extreme lateral transcondylar approach to avoid brain stem retraction.
Evaluation of Antimycotic Activity of Extracts of Marine Algae Collected from Red Sea Coast, Jeddah, Saudi Arabia  [PDF]
Huda Sheikh, Amal El-Naggar, Danyah Al-Sobahi
Journal of Biosciences and Medicines (JBM) , 2018, DOI: 10.4236/jbm.2018.64004
Abstract: In the present study, fifteen species of the dominant marine algae were collected during summer 2013 from four selected sites on Red sea coast, Jeddah, Saudi Arabia. The collected species belonged to Chlorophyta, Phaeophyta and Rhodophyta. Crude algal extracts were prepared by successive extractions using different solvents (acetone, ethanol, diethyl ether, ethyl acetate, methanol and petroleum ether). The crude algal extracts were examined for their antifungal efficacy against Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Candida albicans and Candida tropicalis using agar well diffusion method. The algal extracts evoked different patterns of antifungal activities. Results reveal that acetone was the best solvent suited for extraction of bioactive compounds from tested seaweeds with inhibition activity (19.3%) followed by ethyl acetate (17.1%), ethanol (16.4%), petroleum ether (15.9%), diethyl ether (15.85%), and finally methanol (15.4%). Chlorophyta exhibited the highest antimycotic effect followed by Rhodophyta and Phaeophyta. In Chlorophyta, the extracts of Ulva intestinalis were the most potent followed by U. lactuca, C. racemosa, U. linza and U. reticulate. Acanthophora spicifera showed the highest activity in Rhodophyta, followed by J. rubens, D. simplex, L. obtusa, G. gracilis, G. vermicuphylla and G. multipartita. Whereas, T. triquetra was the most effective species in Phaeophyta followed by P. pavonica and D. dichotoma. The minimal inhibitory concentrations (MICs) of the most potent algal extracts were in the range of 0.5 to 4 mg/ml. The results confirmed the antimycotic potentiality of seaweed extracts.
INFRAPOPULATION GROWTH AND RESOURCE UTILIZATION OF GYRODACTYLUS RYSAVYI AND MACROGYRODACTYLUS CONGOLENSIS (MONOGENEA : GYRODACTYLIDAE) FROM THE SKIN AND FINS OF THE NILE CATFISH CLARIAS GARIEPINUS : FIELD AND LABORATORY STUDIES
AHMED M. EL-NAGGAR
Indian Streams Research Journal , 2013,
Abstract: Infrapopulation growth and resource utilization of two cohabitant, viviparous gyrodactylid monogeneans, namely Gyrodactylus rysavyi Ergens, 1973 andMacrogyrodactylus congolensis (Prudhoe, 1957) Yamaguti, 1963 from the skin and fins of the Nile catfish Clarias gariepinus (Burchell, 1822), were studied under natural and experimental conditions. Field data revealed that either monogenean species attained low infrapopulation growth, where the threshold or ceiling intensity on a medium-sized catfish (total length= 30±2 cm) was 30 worms for the large-sized M. congolensis and 300 worms for the comparatively small-sized G. rysavyi. On naturally infested catfish, the ceiling densities for M. congolensis and G. rysavyi were 0.08 worms/cm2 and one worm/cm2, respectively. Under laboratory conditions, each monogenean species exhibited an exponential infrapopulation growth and microhabitat expansion over vacant sites of attachment during monospecific infestation. The threshold or ceiling intensity on a medium-sized catfish was approximately 300 worms for M. congolensis and up to 25000 worms for G. rysavyi. The ceiling densities for M. congolensis and G. rysavyi were 0.8 worms/cm2 and 100 worms/cm2, respectively. The present monospecific infestation experiments revealed that G. rysavyi is highly proliferating than M. congolensis. Surprisingly, few Gyrodactylus worms registered at the initial phase were found to multiply rapidly, giving birth up to 25000 worms at the terminal phase of the infestation course, within approximately 5 weeks. On the other hand, during experimental mixed infestation, G. rysavyi proliferated more rapidly and outnumbered M. congolensis. Factors promoting gyrodactylid infrapopulation proliferation and those inducing infrapopulation crash are discussed in detail.
A PRELIMINARY REPORT ON THE ECOLOGICAL INTERACTION BETWEEN GYRODACTYLUS RYSAVYI AND MACROGYRODACTYLUS CONGOLENSIS, VIVIPAROUS GYRODACTYLID MONOGENEANS FROM THE SKIN AND FINS OF THE NILE CATFISH CLARIAS GARIEPINUS
AHMED M. EL-NAGGAR
Indian Streams Research Journal , 2012,
Abstract: A preliminary report has been given of the ecological interaction between two cohabitant viviparous gyrodactylid monogeneans, namely Gyrodactylus rysavyi Ergens, 1973 and Macrogyrodactylus congolensis (Prudhoe, 1957) Yamaguti, 1963, skin dwellers of the Nile catfish Clarias gariepinus. These monogeneans are very highly host specific and occupy a definite niche on the catfish host. They showed considerable morphological, ecological and behavioural variations. The small-sized G. rysavyi is a fast-growing species and attains a high reproductive potential. In contrast, the cohabitant, large-sized M. congolensis is a slow-growing species and attains a comparatively lower reproductive potential. While the attachment of M. congolensis is highly destructive to the niche, the footprint of G. rysavyi is less destructive. On the feral catfish population, these monogeneans typically survive at low prevalence, mean intensity and abundance, and tend to aggregate in restricted niches, namely the dorsal surface of the head region. In all experimental bispecific monogenean infestation trials, G. rysavyi outnumbered its rival, M. congolensis. However, in all monospecific monogenean infestation trials, each species exhibited an exponential growth followed by a dramatic decline and eventual disappearance from the catfish host population. The proximate and ultimate causes as well as the consequences of the ecological interaction between G. rysavyi and M. congolensis are discussed in detail.
Alkali Metal Modification of Silica Gel-Based Stationary Phase in Gas Chromatography
Ashraf Yehia El-Naggar
Advances in Materials Science and Engineering , 2013, DOI: 10.1155/2013/982029
Abstract: Modification of the precipitated silica gel was done by treatment with alkali metal (NaCl) before and after calcination. The silica surfaces before and after modification were confirmed by infrared spectroscopy in order to observe the strength and abundance of the acidic surface OH group bands which play an important role in the adsorption properties of polar and nonpolar solutes. The surface-modified silica gels were tested as GC solid stationary phases in terms of the separation efficiency for various groups of non-polar and polar solutes. Also, thermodynamic parameters ( , , and ) were determined using n-hexane as a probe in order to show the adsorbate-adsorbent interaction. It was observed that the non-polar solutes could be separated Independent on the reactivity and porosity of the silica surfaces. The efficiency of the surface-modified silica gels to separate the aromatic hydrocarbons seemed to be strongly influenced by the density of the surface hydroxyls. 1. Introduction The technique of bonding with transition metal complexesinvolves bonding the transition metals to support surface with the help of suitable ligand (mostly silanes) having their hydrocarbon chain terminated with appropriate functional group in order to form π-complexes [1]. Using such complexes in GC is characterized by high selectivity to separate compounds of similar chemical structure and boiling temperatures (like separation of different types of isomers and isotopes), thermal stability, and high resistance to external factors [2]. Moreover, the feasibility of wide control of complexing parameters makes the packings interesting not only from the analytical but also from the physical and chemical points of view. The nature of stationary phases [3–11] in gas chromatography is the main GC part for covering many applications [12–14] with high efficiency of separation in addition to the used detector type [15] and the optimum conditions [16]. The separation mechanism of transition metal complexes dependeds on the formation of metastable complexes either of organic type or with cations of transition metals. The cations of metals showing electron deficiency have at least one empty valence orbital which can be involved in the coordinative interactions [17]. Wasiak et al. [18–22] produced selective complexing sorbent which solves many analytical problems such as (i) the use of Ni and Co complexes bonded to the silica surface via β-diketonate groups to elute alkane-alkene pairs [18] or via thiol groups for separation of cyclic hydrocarbons, cyclic ethers, and chloro derivatives of
A One-Dimensional Flow Analysis for the Prediction of Centrifugal Pump Performance Characteristics
Mohammed Ahmed El-Naggar
International Journal of Rotating Machinery , 2013, DOI: 10.1155/2013/473512
Abstract: A one-dimensional flow procedure for analytical study of centrifugal pump performance is done applying the principle theories of turbomachines. Euler equation and energy equation are manipulated to find pump performance parameters at different discharge coefficients. Fluid slippage loss at impeller exit and volute loss are estimated. The fluid slippage is modeled by the slip factor approach using Wiesner empirical expression. The volute loss model counts friction loss associated with the volute throw flow velocity, diffusion friction loss due to circulation associated with volute flow, loss due to vanishing of radial flow at volute outlet, and loss inside pump volute throat. Models for impeller hydraulic friction power loss, disk friction power loss, internal flow leakage power loss, and inlet shock circulation power loss are considered by suitable models. Pump internal volumetric flow leakage and volumetric efficiency are related to pump geometry and flow properties. The procedure adopted in this paper is capable of obtaining performance characteristic curves of centrifugal pump in a dimensionless form. Pump head coefficient, manometric efficiency, power coefficient, and required NPSH are characterized. The predicted coefficients and obtained performance curves are consistent with experimental characteristics of centrifugal pump. 1. Introduction Centrifugal pumps are used in various applications and are integral to many industries. Yet, in spite of their prevalence and relatively simple configurations compared to other turbomachines, designing an efficient and durable pump remains a challenge. The design of centrifugal pumps is still determined empirically because it relies on the use of a number of experimental and statistical rules. However, during the last few years, the design and performance analysis of turbomachinery have experienced great progress due to the joint evolution of computer power and the accuracy of numerical methods. The one-dimensional performance analysis has proved to be an effective and important approach on pump design [1]. Analytical calculations of pump characteristics depend on geometrical dimensions of pump and losses models in different parts of pump. A series of formulae for calculating losses exist [2–5], but they lack accuracy when applied to centrifugal pumps. In this work, suggested models for calculating several losses in pump are introduced to examine its validity in evaluating pump performance. This paper is an effort towards theoretically obtaining accurate centrifugal pump performance characteristics. Pump
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