184 research outputs found

    An Overview of Differences Between Types of Chimeras and Their Impact on Humans

    Get PDF
    Chimera has several important definitions that are common to each other, where he is known a single creature that is made up of two or more separate populations of genetically unique cells that originated from various zygotes. Definition can be interpreted as cells from one person might appear in another individual in a process known as chimerism. These cells may be incorporated into the parenchyma or they may circulate. Chimeras are divided into several types depending on several factors such as the percentage of chimera cells in the body of the organism neighborhood, origin, or other reasons, which includes microchimeras, natural human macro-chimeras and man-made chimeras. Chimeric cells in human can arise from three significant sources, namely originating from gestation, blood transfusions, and transplants

    The Qatar Biobank: background and methods

    Get PDF
    Background: The Qatar Biobank aims to collect extensive lifestyle, clinical, and biological information from up to 60,000 men and women Qatari nationals and long-term residents (individuals living in the country for ≥15 years) aged ≥18 years (approximately one-fifth of all Qatari citizens), to follow up these same individuals over the long term to record any subsequent disease, and hence to study the causes and progression of disease, and disease burden, in the Qatari population. Methods: Between the 11th-December-2012 and 20th-February-2014, 1209 participants were recruited into the pilot study of the Qatar Biobank. At recruitment, extensive phenotype information was collected from each participant, including information/measurements of socio-demographic factors, prevalent health conditions, diet, lifestyle, anthropometry, body composition, bone health, cognitive function, grip strength, retinal imaging, total body dual energy X-ray absorptiometry, and measurements of cardiovascular and respiratory function. Blood, urine, and saliva were collected and stored for future research use. A panel of 66 clinical biomarkers was routinely measured on fresh blood samples in all participants. Rates of recruitment are to be progressively increased in the coming period and the recruitment base widened to achieve a cohort of consented individuals broadly representative of the eligible Qatari population. In addition, it is planned to add additional measures in sub-samples of the cohort, including Magnetic Resonance Imaging (MRI) of the brain, heart and abdomen. Results: The mean time for collection of the extensive phenotypic information and biological samples from each participant at the baseline recruitment visit was 179 min. The 1209 pilot study participants (506 men and 703 women) were aged between 28–80 years (median 39 years); 899 (74.4 %) were Qatari nationals and 310 (25.6 %) were long-term residents. Approximately two-thirds of pilot participants were educated to graduate level or above. Conclusions: The pilot has proven that recruitment of volunteers into the Qatar Biobank project with intensive baseline measurements of behavioural, physical, and clinical characteristics is well accepted and logistically feasible. Qatar Biobank will provide a powerful resource to investigate the major determinants of ill-health and well-being in Qatar, providing valuable insights into the current and future public health burden that faces the country.Qatar Foundation for Education, Science and Community Development and the Supreme Council of Healt

    Bilateral Anterior Ischaemic Optic Neuropathy in a Child on Continuous Peritoneal Dialysis : Case report and literature review

    Get PDF
    Non-arteritic anterior ischaemic optic neuropathy (NAION) is a serious complication of continuous peritoneal dialysis (CPD) which can lead to poor vision and blindness. We report a five-year-old girl who had undergone a bilateral nephrectomy at the age of one year and was on home CPD. She was referred to the Paediatric Ophthalmology Unit of Sultan Qaboos University Hospital, Muscat, Oman, in 2013 with acute bilateral vision loss, preceded by a three-day history of poor oral intake. At presentation, the patient had severe systemic hypotension. An ophthalmological examination revealed severe bilateral visual impairment and NAION. She was treated with intravenous methylprednisolone and normal saline boluses. At a five-month follow-up, the visual acuity of the right eye had improved but vision in the left eye remained the same. Acute bilateral blindness due to NAION while on CPD is a rare condition in childhood. Paediatricians should be aware of this complication in order to ensure prompt management.Keywords:

    Review Article p16 INK4A and p14 ARF Gene Promoter Hypermethylation as Prognostic Biomarker in Oral and Oropharyngeal Squamous Cell Carcinoma: A Review

    Get PDF
    Head and neck squamous cell carcinoma is a heterogeneous group of tumors with each subtype having a distinct histopathological and molecular profile. Most tumors share, to some extent, the same multistep carcinogenic pathways, which include a wide variety of genetic and epigenetic changes. Epigenetic alterations represent all changes in gene expression patterns that do not alter the actual DNA sequence. Recently, it has become clear that silencing of cancer related genes is not exclusively a result of genetic changes such as mutations or deletions, but it can also be regulated on epigenetic level, mostly by means of gene promoter hypermethylation. Results from recent studies have demonstrated that DNA methylation patterns contain tumor-type-specific signatures, which could serve as biomarkers for clinical outcome in the near future. The topic of this review discusses gene promoter hypermethylation in oral and oropharyngeal squamous cell carcinoma (OSCC). The main objective is to analyse the available data on gene promoter hypermethylation of the cell cycle regulatory proteins p16 INK4A and p14 ARF and to investigate their clinical significance as novel biomarkers in OSCC. Hypermethylation of both genes seems to possess predictive properties for several clinicopathological outcomes. We conclude that the methylation status of p16 INK4A is definitely a promising candidate biomarker for predicting clinical outcome of OSCC, especially for recurrence-free survival

    Roasted-modified Date Pits In Remediation Of Bromide Ions From Desalinated Water: Kinetic Studies

    Get PDF
    Disinfection of drinking water is one of the extreme public health activities in Qatar. Chlorination, ozonation, ultra-violet, chloramination, and others are the most important treatment processes used and they can cause the formation of toxic by-products. The existence of bromide (Br-), for example, in water sources might cause in formation of brominated toxic by-products. Up-to-date drinking water treatment methodologies are challenged to successfully eliminate Br- before final consumption. Remediation onto activated carbons has a number of restrictions. Date pits are suitable as raw remediating adsorbent for preparing various modified adsorbents, because particular surface functional groups and the micro-pore structures can be attained by active modifications. The overall objective of this study was to develop an economical and environmentally acceptable process to safely eliminate the levels of Br- from desalinated water. Roasted date pits (RODPs) and activated charcoal (AC) (used as a control) were crushed and sieved with four different particles size ranges. The percentage of Br- removal was also studied under different experimental conditions such as pH, sorbent mass and initial concentration. In addition, surface characterization was also investigated. Experimental date analyses were investigated using different isotherm and kinetic sorption models. The modification of the date pits surface enhanced the Br- removal capacity at high initial concentration of bromide (200 ppm) by 27%. Using scanning electron microscope (SEM), the date pits surface images showed a different in pore sizes upon modification. Removal capacity of RODPs reached 39% at pH 4. In this study the heterogeneity of adsorbing mechanisms and the fitting with pseudo second order model and inter particulate diffusion models were concluded, and more than 35% of Br- removal efficiency was achieved within the RODPs at the first hour of contact time. The adsorption Br- onto RODPs was not fitted well with the pseudo-first order model. It was found that the kinetics of Br- adsorption was followed the pseudo-second order. It was also observed fluctuations in the removal efficiency for smaller particle sizes; indicating heterogeneity of adsorption/desorption and potential chemical bindings, this particular behaviour was not observed and investigated elsewhere in the literature (Figure below). The surface of RODPs contains oxygen functional groups such hydroxyl; hence the presence of such functional groups on the surface of date pits considerably influences on the adsorption mechanism of organic and inorganic compounds on the RODP. Economically RODPs are successfully used to remove Br-, comparing to AC. However, both adsorbents have nearly the same removal efficiency after one hour contact time. Apparently, the removal efficiency of both systems was quite significant. This may cover the way for the cheap and widely available date pits to be used as an adsorbent in water purification process.qscienc
    • …
    corecore