oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 167 )

2018 ( 207 )

2017 ( 173 )

2016 ( 216 )

Custom range...

Search Results: 1 - 10 of 9721 matches for " Osama Ahmed "
All listed articles are free for downloading (OA Articles)
Page 1 /9721
Display every page Item
Metachronous double malignancy involving the kidney and the breast: A case report  [PDF]
Osama Ahmed, Tahir Abbas
Case Reports in Clinical Medicine (CRCM) , 2014, DOI: 10.4236/crcm.2014.32016
Abstract:

The occurrence of multiple primary cancers is rare; it can be missed as a disease progression. The etiology remains controversial. We report a case of a 55-year-old female with metastatic renal cell carcinoma treated with sutent followed by left sided nephrectomy. Follow-up CT showed increase in the size of the right axillary lymph nodes which was proven after biopsy to be metastatic adenocarcinoma of the breast. Any suspicious disease progression in a single site not compatible with disease history should be biopsied for confirmation. The relationship between renal cell carcinoma and breast cancer is still unclear, and more case reports are required to determine this relationship.

Dilemma of HCV Infection in Renal Transplant Recipients
Osama Ashry Ahmed Gheith
International Journal of Nephrology , 2011, DOI: 10.4061/2011/471214
Abstract: Hepatitis C virus, which usually starts during dialysis therapy, is currently the main cause of chronic liver disease in such population. The majority of patients acquired the disease through intravenous drug use or blood transfusion, with some risk factors identified. In this review we are dealing with the effect of renal transplantation on HCV infection and HCV-related complications after renal transplantation. Moreover, we are discussing the therapeutic options of HCV infection before and after renal transplantation, the best immunosuppressive protocol and lastly graft and patient survival in patients who underwent pretransplant management vs. those who were transplanted without treatment. 1. Introduction Liver disease is one of the leading causes of death in long-term renal transplant survivors [1, 2], and hepatitis C virus (HCV) is currently the main cause of chronic liver disease in such population [1–7]. Hemodialysis patients represent a high-risk group for HCV infection, possibly due to a direct or indirect exposure to contaminated blood [6]. Although HCV infection may be transmitted through transplantation itself [1, 8], it usually starts during dialysis therapy [1–4]. 2. HCV Genotypes and Prevalence Worldwide, at least 6 major genotypes of the HCV have been identified, each comprising multiple subtypes [9–13]. Genotypes 1, 2, and 3 have a worldwide distribution, while their relative prevalence varies from one geographic area to another. Hepatitis C virus subtypes 1a and 2b are the most common genotypes in the United States and Europe [14–16]. Subtype 1b is responsible for up to 73% of HCV infection in Japan [17]. Subtypes 2a and 2b are relatively common in North America, Europe, and Japan, while 2c is found commonly in Northern Italy. Intravenous drug abusers in Europe and the United States have the HCV genotype 3a [18]. Genotype 4 appears to be prevalent in North Africa and the Middle East while genotypes 5 and 6 in South Africa and Hong Kong [10–12]. 3. Transmission The majority of HCV infected patients acquired the disease through intravenous drug use or blood transfusion, with the following risk factors identified [13]: intravenous drug use, blood transfusion, sex with an intravenous drug user, having been struck or cut with a bloody object, pierced ears or body parts, and immunoglobulin injection. Other risk factors identified among dialysis patients included blood transfusions, the duration of end-stage renal disease (and dialysis), the type of dialysis (risk is the highest with in-hospital hemodialysis especially with lack of adherence
Gene Expression Profiling in Organ Transplantation
Osama Ashry Ahmed Gheith
International Journal of Nephrology , 2011, DOI: 10.4061/2011/180201
Abstract: Aim of Review. Huge effort is being made among the transplant community investigating novel biomarkers that enable transplant clinicians to identify patients at risk for allograft rejection or those who will develop tolerance so that immunosuppression could be safely minimized or even ideally withdrawn. Despite the important advances achieved in the identification of several potential biomarkers of tolerance, rejection, or both, validation and demonstration of their clinical utility still needs to be tested, which will need international cooperative networks. It is important to note that the reproducibility of differently expressed genes might be affected by many factors such as gene ranking and selection methods, inherent differences between types, and the choice of thresholds. However, because microarray analyses are expensive and time consuming and their statistical evaluation is often very difficult, gene expression analysis using the RTPCR method is nowadays recommended. Conclusions. In the field of organ transplantation, gene-expression-based decision might help in improving patient and graft outcome and there are a multitude of studies showing that gene-expression profiling is feasible. 1. Introduction Despite the improvement in both patient and short-term renal allograft survival in the last decade, probably because of newer and more specific immunosuppressive agents in addition to improved surgical and medical cares, Long-term graft failure continues to plague kidney allografts with both immune-dependent and -independent factors which continue to contribute to failure. Even the morbidity and mortality remain much higher than in the general population, mainly due to the complications of immunosuppressive therapy. A number of promising observations made in human kidney recipients suggest unique protein and genetic signatures that may identify biomarkers of injury, as well as potential targets of therapy. Some of these may be obtained through noninvasive methods and may thus be extremely useful in the clinical realm [1, 2]. Nonspecific etiopathogenic graft parenchymal lesions in allograft biopsies, graft function evolution using surrogate markers of graft dysfunction such as serum creatinine or proteinuria, and indirect measurements of the alloimmune response using blood trough levels of immunosuppressants are the current markers used worldwide in the clinic in renal transplantation [3]. 2. Biomarkers of Allograft Outcome Huge effort is being made among the transplant community investigating novel biomarkers at different biological levels that
Pericardial Strip versus Ring Annuloplasty for Repair of Functional Tricuspid Regurgitation  [PDF]
Husain Hamza Jabbad, Ahmed Abdelrahman Elassal, Osama Saber Eldib
World Journal of Cardiovascular Surgery (WJCS) , 2014, DOI: 10.4236/wjcs.2014.412035
Abstract: Background: Functional tricuspid regurgitation is a challenge regarding indications for repair and proper surgical technique. Aim of the study: We reviewed our midterm results of tricuspid valve repair for functional regurgitation comparing pericardial strip versus ring annuloplasties. Patients and methods: From January 2008 to December 2013, we operated 59 patients (male:female, 41:18, with a mean age of 34 ± 14 years) for functional tricuspid regurgitation. Tricuspid annuloplasty was done using pericardial strip in 39 patients and ring in 20 patients. Concomitant procedures were mitral valve replacement in 66% of patients, aortic valve replacement in 5% and double valve replacement in 29%. Clinical and echocardiographic data were collected. Results: Preoperative characteristics of the two groups were similar regarding age, percentage of female patients, New York Heart Association functional class and pulmonary artery pressure. More patients with preoperative right ventricular dysfunction were found in pericardial annuloplasty group although this was not statistically significant (13 versus 5; P = 0.52). Operative times were similar in both groups. We had one mortality case (1.69%) due to low cardiac output in the pericardial group. Postoperative complications included reexploration for bleeding in one patient and chronic heart failure in another patient. The average follow up period was 3 years and it was complete in 100% of patients. Postoperative freedom from recurrent moderate tricuspid regurgitation was 90% in both groups. Conclusion: Pericardial strip annuloplasty is a simple, inexpensive, reproducible and efficient technique that has comparable results to ring annuloplasty.
Performance Evaluation of Gated Pipes Technique for Improving Surface Irrigation Efficiency in Maize Hybrids  [PDF]
Osama A. M. Ali, Ahmed S. H. Mohammed
Agricultural Sciences (AS) , 2015, DOI: 10.4236/as.2015.65055
Abstract: Waterlogging and low application efficiency are the main problems inherent with surface irrigation in the Nile Delta. Develop surface irrigation using gated pipes (GP) is a new method to be used to distribute water into furrow irrigated fields as strategy based on water saving. Laboratory calibration was conducted out to evaluate the hydraulic characteristics of pipe gates. Field experiments were conducted at the Experimental Farm of the Agriculture Faculty, Minufiya University during 2013 and 2014 seasons to evaluate the performance of utilize gated pipes technique for irrigating five maize varieties (S.C 10, S.C 130, S.C 131, S.C 2031 and T.W.C 321). The results revealed that the highest amount of water applied was with traditional surface irrigation (6423.81 m3·ha-1. Use of gated pipes system GP1 as compared to traditional irrigation reduced water application by 923.81 m3·ha-1 with grain and stover yields increases of 5.7% and 3.4%, respectively. Traditional irrigation system achieved lowest irrigation performance parameters compared to gated pipes systems. Maize physiological attributes, yield, water use efficiency (WUE) and nitrogen accumulation were significantly decreased by either deficit or surplus irrigation than of GP1 rate. S.C 2031 variety significantly surpassed other varieties in abovementioned traits. Significant interaction effects were detected in both seasons. Maize varieties respond differently to irrigation systems. The highest values of grain yield (11062.6 and 10911.8 kg·ha-1 and stover yield (13639.0 and 13902.2 kg·ha-1) were obtained by S.C 2031 irrigated with GP1 system in both seasons. From the above mentioned results, it is concluded that the gated pipes technique is better than traditional irrigation for improving WUE and maize productivity under Nile Delta conditions.
Financial Integration and Portfolio Diversification: Evidence from CIVETS Stock Markets  [PDF]
Kashif Saleem, Osama Al-Hares, Sheraz Ahmed
Theoretical Economics Letters (TEL) , 2016, DOI: 10.4236/tel.2016.66121
Abstract: This paper investigates the extent of financial integration among a new group of six frontier markets called “CIVETS” by utilizing the multivariate GARCH framework of Engle and Kroner [1]. These countries are expected to show sustainable growth in productivity and domestic consumption over the next decade and are considered as potential corridor for the international investor from portfolio diversification point of view. We utilize weekly stock market return series of all the CIVIETS nations, and results exhibit significant return and volatility spillovers among all the markets under investigation. Our results reveal that there are significant linkages among CIVETS stock markets during the time of our analysis. However, the direction of relationship is asymmetric depending on the countries in the model. We believe, CIVIETS stock markets have full potential of being the future investment targets worldwide.
Atypical Clinical Manifestations of Graves' Disease: An Analysis in Depth
Mohamed Osama Hegazi,Sherif Ahmed
Journal of Thyroid Research , 2012, DOI: 10.1155/2012/768019
Abstract: Over the past few decades, there has been an increase in the number of reports about newly recognized (atypical or unusual) manifestations of Graves' disease (GD), that are related to various body systems. One of these manifestations is sometimes the main presenting feature of GD. Some of the atypical manifestations are specifically related to GD, while others are also similarly seen in patients with other forms of hyperthyroidism. Lack of knowledge of the association between these findings and GD may lead to delay in diagnosis, misdiagnosis, or unnecessary investigations. The atypical clinical presentations of GD include anemia, vomiting, jaundice, and right heart failure. There is one type of anemia that is not explained by any of the known etiological factors and responds well to hyperthyroidism treatment. This type of anemia resembles anemia of chronic disease and may be termed GD anemia. Other forms of anemia that are associated with GD include pernicious anemia, iron deficiency anemia of celiac disease, and autoimmune hemolytic anemia. Vomiting has been reported as a presenting feature of Graves' disease. Some cases had the typical findings of hyperthyroidism initially masked, and the vomiting did not improve until hyperthyroidism has been detected and treated. Hyperthyroidism may present with jaundice, and on the other hand, deep jaundice may develop with the onset of overt hyperthyroidism in previously compensated chronic liver disease patients. Pulmonary hypertension is reported to be associated with GD and to respond to its treatment. GD-related pulmonary hypertension may be so severe to produce isolated right-sided heart failure that is occasionally found as the presenting manifestation of GD. 1. Introduction Graves’ disease (GD) accounts for up to 80% of hyperthyroidism cases and is estimated to affect 0.5% of the population [1]. It usually presents with the common well- known symptoms and signs (goiter, ophthalmopathy, weight loss, nervousness, tremors, palpitations, sweating, etc.) which are the distinctive features of the disease (Table 1). We can observe another group of manifestations, such as periodic paralysis, apathy, or psychosis, which are less common and less distinctive despite being well documented in relation to GD (Table 1). Over the past few decades, there has been an increase in the number of reports about newly recognized (atypical or unusual) manifestations of hyperthyroidism that are related to various body systems and may create a wide range of differential diagnosis [2, 3]. Most of these atypical manifestations are
New Look on Ureterocolic Diversion with Adjuvant Radiotherapy; SECI (South Egypt Cancer Institute) Experience  [PDF]
Badawy M. Ahmed, Ebrahim Aboeleuon, Ahmed M. Abdel-Rahim, Osama M. Abd Elbadee
Journal of Cancer Therapy (JCT) , 2018, DOI: 10.4236/jct.2018.911074
Abstract: Background: Ureterosigmoidostomy was the first form of continent urinary diversion and had broad popularity during the first half of the 20th century. Primary enthusiasm was followed by disappointment when serious problems such as pyelonephritis, electrolyte imbalance, renal calculi and renal function deterioration become evident. In the 1950s these life threatening complications led to avoid this urinary diversion in favor of uretro-intestinal conduits. Objectives: Our aim was to evaluate our experience in ureterocolic shunt after radical cystectomy for bladder cancer. Methodology: This study was conducted in surgical oncology department, South Egypt cancer institute, Assiut university; in the period from January 2012 to January 2017 and including 115 patients (75 males & 40 females). Results: This is retrospective study including 115 patients (75 males & 40 females). Operative time was 130 minutes ranging between 2 to 2.5 hours. Average blood loss was 450 ml. After removal of rectal tube all patients were continent except 15 patients who were improved after 1 - 3 days. Within a month 12 patients had night incontinence and 5 patients had day time incontinence. After that day and night continence gradually improved in all patients except two females who had persistent night soiling and was in need for night time rectal tube.
Mutual Coupling Effect on Ultrawideband Linear Antenna Array Performance
Osama Ahmed,Abdel-Razik Sebak
International Journal of Antennas and Propagation , 2011, DOI: 10.1155/2011/142581
Abstract: This paper studies the mutual coupling effect between array elements of two- and four-element ultrawideband (UWB) linear arrays on their performances. For simplicity, it is assumed that both antenna arrays are fed by independent microstrip lines with the same power amplitudes and equal phases. From our study, array bandwidth improvement is achieved for both array types when the mutual coupling is strong enough or interelement spacing is small. The mutual coupling also enhances the array realized gain especially in the midfrequency band (5–8.5?GHz) while it deteriorates the gain outside that frequency range. Proper tuning for interelement spacing with enough mutual coupling enhances the array realized gain at most frequencies and makes it more stable across the desired frequency range. From the radiation pattern results, the grating lobes appear in UWB arrays when the element spacing is greater than two wavelengths at the upper edge frequency, 10.6?GHz, or half wavelength at the lower edge frequency 3.1?GHz. Two fabricated array prototypes with corporate feed are fabricated and tested to validate the theoretical analysis. The effect of using -junction power divider is clear on the reflection coefficient . Both numerically simulated and experimental results successfully demonstrate our analysis. 1. Introduction Ultrawideband (UWB) technology has inspired many academic researchers, scientists, and industrialists since the Federal Communication Commission (FCC) announced the use of unlicensed frequency band of 3.1–10.6?GHz for commercial communication applications in 2002 [1]. This available wide bandwidth enables UWB systems to achieve high speed and high data rates in communications applications, that is, more than 500?Mbps [2], high accuracy in localization systems [3], or very high resolution in radars’ applications [4]. The antenna is considered an important component in the UWB system, and it affects the overall performance of the system. Researchers have developed recently many different antenna designs for UWB applications with wide impedance bandwidth, linear phase, reasonable gain, and stable radiation characteristics across the whole UWB frequency band [5–8]. In certain applications such as microwave imaging, localization or radar applications, high gain is needed. Typically the UWB single antenna element has relatively low gain of order 3-4?dBi, which can be improved using antenna arrays. Antenna arrays are widely used in many practical systems to enhance gain or provide beam scanning capability. Mutual coupling among antenna elements is an
Numerical and Experimental Investigation of a Novel Ultrawideband Butterfly Shaped Printed Monopole Antenna with Bandstop Function
Osama Mohamed Haraz Ahmed;Abdel Razik Sebak
PIER C , 2011, DOI: 10.2528/PIERC10102906
Abstract: In this paper, a novel compact butterfly shaped printed monopole antenna for ultra-wideband (UWB) applications is presented. The proposed antenna is designed with a standard printed circuit board (PCB) process for suitable integration with other microwave components. The antenna prototype is designed then fabricated and tested experimentally. The calculated impedance bandwidth of the proposed antenna ranges from 3 GHz to 13 GHz for a 10 dB reflection coefficient (S11) while the measured impedance bandwidth ranges from 3 GHz to 10.8 GHz covering the whole UWB frequency range. The measured antenna radiation patterns show relatively stable radiation patterns with almost constant gain over the whole frequency band of interest. By introducing a slit ring resonator (SRR) in the feedline, a bandstop of 830 MHz from 5.0 to 5.83 GHz for band rejection of wireless local area network (WLAN) can be achieved. So, the proposed antenna is considered a good candidate for future UWB communication systems.
Page 1 /9721
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.