89 research outputs found

    Feline patent Toxoplasma-like coccidiosis among feral cats (Felis catus) in Doha city, Qatar and its immediate surroundings

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    Doha city has a high feral cat population and studies of hospital records in Doha have shown that human toxoplasmosis also occurs. Clearly, there is a need to understand the role of cats as vectors of human toxoplasmosis in the city and as a first step we assessed the extent of patent Toxoplasma-like coccidial infections among feral cats. Oocysts in cat faeces were detected between June 2008 and April 2010, from a range of locations radiating out of the city centre in concentric semi circular/elliptic rings and by north, west and south divisions within each of the rings. In total 4,652 cats were sampled and overall prevalence of oocysts was 9.1%. Prevalence was 10.1% in the first summer, and then dropped to 8.4% in the following winter and further to 6.8% in the next summer before rising to 10.6% in the final winter of the study; this interaction between annual period and season was significant. There were also significant changes in prevalence across each of the consecutive months of the study, but no clear pattern was evident. Prevalence did not vary significantly by city sector and there was no difference in prevalence between the host sexes. We conclude therefore, that despite minor and significant perturbations, the prevalence of patent Toxoplasma-like coccidial infections among cats in Doha is remarkably stable throughout the year, across years and spatially within the city’s districts.Qatar National Research Funds Student grant UREP 05 – 060 – 3 – 01

    In silico investigation of lactone and thiolactone inhibitors in bacterial quorum sensing using molecular modeling

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    In the present study, the origin of the anti-quorum sensing (QS) activities of several members of a recently synthesized and in vitro tested class of lactone and thiolactone based inhibitors were computationally investigated. Docking and molecular dynamic (MD) simulations and binding free energy calculations were carried out to reveal the exact binding and inhibitory profiles of these compounds. The higher in vitro activity of the lactone series relative to their thiolactone isosteres was verified based on estimating the binding energies, the docking scores and monitoring the stability of the complexes produced in the MD simulations. The strong electrostatic contribution to the binding energies may be responsible for the higher inhibitory activity of the lactone with respect to the thiolactone series. The results of this study help to understand the anti-QS properties of lactone-based inhibitors and provide important information that may assist in the synthesis of novel QS inhibitors

    Intestinal Parasitic Infections among Long-Term-Residents and Settled Immigrants in Qatar in the Period 2005 to 2011

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    Abstract. The expanding economy of Qatar in the last two decades has attracted immigrants, often from countries with poor socio-economic levels. Many arrive with patent intestinal parasitic infections, and recent analyses have indicated consistently rising trends in the prevalence of some infections. Here, we examined 18,563 hospital records of subjects in Qatar seeking medical assistance for a variety of ailments, combining data from 2009 to 2011 with the earlier dataset from 2005 to 2008 to enable trends to be identified across a 7-year period. We found that 8.6% were infected with one or more species of parasites, however in contrast to the earlier period (2005–2008), in the latter 3 years there were falling trends of prevalence providing some optimism that parasitic infections among the resident immigrants have begun to decline. We identified also geographic regions from which resident workers still maintain a relatively high prevalence of helminth infections despite their long-term residence in Qatar.This publication was made possible by a grant from Qatar National Research Fund (QRNF) at Qatar Foundation through National Priorities Research Program (NPRP) (Project No. NPRP 4-1283-3-327

    Seroprevalence and epidemiological correlates of Toxoplasma gondii infections among patients referred for hospital-based serological testing in Doha, Qatar

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    Background. The city of Doha in Qatar has a high density of feral cats and there is a high risk of toxoplasmosis for the resident human population. No data currently exist for the prevalence of infection with Toxoplasma gondii in the city. Methods. We analysed the serological response to Toxoplasma gondii of 1625 subjects referred for routine hospital based serological tests in Doha, Qatar. Prevalence of current/recent infection was assessed through an enzyme-linked immunosorbent assay (ELISA) for the presence of specific anti-T. gondii IgM antibodies, and previous history of infection through IgG. Results. Overall prevalence of IgG responses was 29.8% and this did not differ between the sexes nor between the three years of the study although there was a marked age effect. Among children less than 1 year old prevalence was 22.9%, but then dropped to 45 years). The prevalence of IgG antibody also varied significantly with region of origin, with higher rates for subjects from Africa, followed by those from the Eastern Mediterranean or Asia and lowest rates for subjects from the Arabian Peninsula. No IgM antibodies were detected in any subjects younger than 19 years, but prevalence increased to plateau at 7 - 9% in subjects aged over 20 years, and also varied with region of origin. In this case prevalence was highest among subjects from the Arabian Peninsula and least among those from Asia. Prevalence of IgM was higher among male subjects but did not vary between the three years of the study. Conclusion. Although these data are based on a selected subset of the population, they nevertheless provide the first evidence that toxoplasmosis is endemic in Qatar in the human population, and that both age and region of origin play a role in the epidemiology of the infection. Concerns relating to the role of high density of feral cats in sustaining the infection were highlighted

    Toxoplasma gondii Seropositivity and Co-Infection with TORCH Pathogens in High-Risk Patients from Qatar

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    Testing of patients who are deemed to be at high risk for TORCH pathogens, e.g., pregnant women, their fetuses, neonates, and acquired immunodeficiency syndrome (AIDS) patients, is important so that specific treatment can be initiated. This study included 1,857 such patients between 2005 and 2008. Logistic regression was used to evaluate factors associated with Toxoplasma gondii seropositivity. Among 823 women of childbearing age, 35.1% and 5.2% tested positive for T. gondii IgG and IgM, respectively. Three infants ≤ 6 months of age (0.8% of 353) were congenitally infected. Factors associated with T. gondii IgG seropositivity included older age, East Mediterranean or African nationality, positive cytomegalovirus (CMV) and herpes simplex virus (HSV)-1 serostatus, and negative rubella IgG results. The decreasing prevalence of IgM antibodies between 2005 and 2008 suggested that exposure to T. gondii from food or environmental sources declined over this period in Qatar. Population-based studies of newborns would be helpful to accurately estimate incidence of congenital toxoplasmosis

    Comparison of intestinal parasitic infection in newly arrived and resident workers in Qatar

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    Abstract Background: The rapid growth of Qatar in the last two decades has been associated with an enormous expansion of building programs in its cities and in the provision of new service industries. This in turn has attracted a large influx of immigrant workers seeking employment in jobs associated with food handling, domestic service and the building industry. Many of these immigrants come from countries in the tropics and subtropics where intestinal parasitic infections are common. Methods: We analyzed intestinal parasitic infections recorded in 2008 among immigrant and long-term resident workers in Doha city, Qatar (n = 1538). Stool examinations were carried out at the Hamad Medical Corporation and at the Medical Commission in Doha using standard procedures. Results: Overall, 21.5% of subjects were infected with at least one of the species recorded (8 helminth and 4 protozoan species; the highest prevalence was for hookworms = 8.3%) and there were strong regional effects on prevalence of helminths, with subjects from North East Africa and Nepal showing particularly high prevalence. Most helminths declined in prevalence in subjects that acquired residency status in Qatar, especially among female subjects, but there was a marked exception among male Nepalese workers, who continued to harbour helminth infections (notably hookworms) after they became residents. Contrary to all other regional groups the prevalence of Giardia duodenalis was higher among Nepalese residents compared with new arrivals, while Blastocystis hominis infections were more common among residents of all regions, and especially among North East Africans. Conclusions: Our analysis has identified male Nepalese workers as a particular risk group continuing to harbour hookworm infection and G. duodenalis as residents, and subjects from North East Africa are as particularly likely to acquire B. hominis infection after settling in the country. These conclusions have important implications for the health authorities in QatarQatar National Research Fund (QRNF) NPRP Grant# 4-1283-3-32

    Prevalence of Hepatitis C Virus Seropositivity and Its Impact on Coronary Artery Disease among Egyptian Patients Referred for Coronary Angiography

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    Background. We tested the prevalence and impact of HCV seropositivity among Egyptian patients referred for coronary angiography. Subjects and Methods. This cross-sectional study was conducted in Zagazig University hospitals including 509 patients scheduled for elective coronary angiography between June 2013 and June 2014. By taking full history on admission, laboratory workup including HCV Ab, echocardiography study, and coronary angiography, we calculated the mean number of coronary artery lesions and the mean number of affected coronary artery vessels for all patients. The severity of the coronary lesions was estimated using the Gensini score. Results. HCV seropositive patients referred for coronary angiography were about 30.3% (which is greater than the prevalence of HCV seropositivity among general population in Egypt), patients proved to have CAD who are HCV antibody positive had more severe coronary lesions than in seronegative one (p<0.05), and patients proved to have CAD who are HCV antibody positive had comparable prevalence of cardiovascular risk factors as seronegative patients except for diabetes and hypertension which are more prevalent in seronegative patients (p<0.05). Conclusion. Prevalence of HCV antibody positive patients referred for coronary angiography was about 30.3%, and CAD patients who are HCV antibody positive had more severe coronary lesions and less prevalence of diabetes and hypertension than HCV antibody negative

    Calcium Tartrate Tetrahydrate, Case Report of a Novel Human Kidney Stone

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    Background: Calcium tartrate tetrahydrate has been reported as the main mineral in urinary stones in rats that have significant tartrate in their diet, but in humans, there has been only one mention of calcium tartrate stones in the form of bladder stone, and that case was in Africa., Case Presentation: Patient is a 34-year-old Caucasian male who presented with typical symptoms of nephrolithiasis. CT abd/pelvis (renal stone protocol) revealed a 2 cm nonobstructing stone of the right renal pelvis. Patient underwent an uncomplicated right percutaneous nephrolithotomy and was noted to be stone free after surgery. Stone analysis was difficult with regard to determining composition, but was finally identified as calcium tartrate tetrahydrate., Conclusion: This was an unusual case, as this is the first recorded case of a calcium tartrate tetrahydrate outside of Africa. This type of stone had only been mainly described in rat models with dl-bitartrate in their diet. Our patient was an otherwise healthy, relatively muscular individual with no obvious source for this stone other than a vitamin and amino acid supplement that he takes regularly that contains l-carnitine (as tartrate) and choline (as bitartrate and citrate). The prevalence of this stone type is presently unknown, as stone analysis laboratories have not had the ability to recognize it. Although a connection between the supplement and stone formation is conjecture at this time, we believe this necessitates further investigation

    DESIGN, SYNTHESIS AND BIOLOGICAL EVALUATION OF SOME NEW SUCCINIMIDE, 2-IMINOTHIAZOLINE AND OXAZINE DERIVATIVES BASED BENZOPYRONE AS ANTICONVULSANT AGENTS

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    Objective: The objective of the present study was to synthesize novel benzopyrone derivatives with potential and safer anticonvulsant activity.Methods: New benzopyrone derivatives have been synthesized and characterized by spectral and elemental analysis. These compounds tested for anticonvulsant activity using the maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) screens (phase 1), which are the most widely employed seizure models for early identification of new anticonvulsant agents. Phase 2 including, neurotoxicity screening and quantitative determination of the median effective dose (ED50), median lethal dose (LD50) and protective index (PI) for the active compounds from phase 1.Results: Compound 12b possessed potent anticonvulsant activity with ED50 values of 94.75 and 70.7 mg/kg in the MES and scPTZ screens respectively, and had LD50 value of 2546 mg/kg after intraperitoneal injection to mice, which provide compound 12b with a wide protective index of 26.87 and 36.01 for MES and scPTZ screens respectively compared to the reference drug Phenobarbital with PI of 12.16 and 20.08, respectively. In addition, compound 12b exhibited mild neurotoxicity at the maximum administrated dose (200 mg/kg).Conclusion: Compound 12b possessed broad spectrum activity for the treatment of all types of seizures, with a wide protective index compared to Phenobarbital. Consequently, compound 12b can be selected as a new bio candidate lead for further study.Keywords: Benzopyrone, Succinimide, 2-Iminothiazoline, Oxazine; Anticonvulsant
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