Advances on Dientamoeba fragilis Infections

Dientamoeba fragilis is an enteric protozoan parasite that remains neglected, probably due to the misconception that it is uncommon and non-pathogenic. As more information became available and antimicrobial agents were developed with activity against this parasite, it became clear that D. fragilis is responsible of an active infection, associated with symptoms such as abdominal pain and diarrhea. The clinical presentation of dientamoebiasis varies from asymptomatic carriage to symptoms ranging from altered bowel motions, abdominal discomfort, nausea and diarrhea with associated eosinophilia reported in up to 50% of paediatric and 10% of adult patients. Moreover, controversy exists over the protective role of the parasite in priming the immune system in a beneficial way such as in selecting beneficial bacteria, keeping potential harmful microbial intruders at bay or producing metabolites beneficial to the host. Thus, a number of ambiguities and obscurities surrounding D. fragilis infections exist. Moreover, the means by which this parasite is transmitted has not been fully defined. The diagnostic recognition of this parasite in fecal examinations requires specific processing and expertise; thus, it is possible that many infections with D. fragilis may go undiagnosed. A number of studies conducted on small numbers of case reports have demonstrated parasite clearance, as well as resolution of clinical symptoms following treatment with various antiparasitic compounds such as paromomycin, hydroxyquinolines and the 5-nitroimidazoles, including metronidazole and tinidazole. In addition there is very little in vitro susceptibility data available for the organism making some current treatment options questionable. This chapter reviews the scientific literature relating to Dientamoeba\u27s life cycle, prevalence, diagnosis and pathogenicity

Effectiveness of Teaching Science Using (PDEODE) Strategy in the Achievement and in the Development of Meta-cognition Skills of the First Grade Middle School Students

This research aimed at identifying the effectiveness of teaching science utilizing (PDEODE) Strategy in the achievement and in the development of meta-cognition skills of the first grade middle school students at Asir region. To achieve this, the Pretest Post-Test control group design was utilized. Both the achievement and the meta cognition skill tests were administered to a sample of 40 students of the first grade middle school students. The sample was divided into two groups: an experimental group which consisted of 19 students and a controlled group which consisted of 21 students. The t-Test and eta square were utilized in statistical treatments and in calculating effect size. Results revealed statistically significant differences at the level of 0.05 between mean scores of the experimental group and the control group in the post-assessment of the achievement and in meta-cognition skill tests favoring the experimental group. Results also indicated a great effect size of (PDEODE) strategy in the Achievement and in developing the meta-cognition skills of the first grade middle school students. Some recommendations and suggestions were presented in light of the research results

End User Satisfaction With Cloud Computing: The Case of Hamad Medical Corporation in Qatar

Cloud computing assures a faster, cheaper and more efficient rendering of resources, which leads to huge popularity among businesses and specifically the health sector. The major objective of this research is to identify the benefits of cloud computing (CC) and the factors influencing users satisfaction. Utilizing a survey collected from 219 employees, the research model was tested. Results indicated that employee compliance issues, security and privacy issues, economic benefits, operational benefits, functional benefits, and trust are all significant predictors of satisfaction. Management issues and private cloud risks were not significant predictors of satisfaction. The coefficient of determination R2 = 0.81. This study conducted comparisons between different categories of the sample based on their satisfaction level and concluded that age and education were significant discriminators, while gender, experience, and department were not. Conclusions and future research are stated in the last section

Engineering of magnetically separable ZnFe2O4@ TiO2 nanofibers for dye-sensitized solar cells and removal of pollutant from water

Abstract In this study, magnetic Zinc Ferrite (ZnFe2O4)@TiO2 nanofibers were prepared by low cost and nontoxic route; hydrothermal technique followed by electrospinning process. The prepared magnetic ZnFe2O4@TiO2 nanofibers were morphologically and structurally analyzed by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), and thermal gravimetric analysis (TGA). The prepared magnetic ZnFe2O4@TiO2 nanofibers were utilized as photoanode for the fabrication of dye-sensitized solar cells (DSSCs) and presented applicable performance with 4.2% overall conversion efficiency with high short circuit current density (JSC) of 10.16 mA/cm2. The maximum ∼42% incident photo-to-current conversion efficiency (IPCE) value was also recorded at 520 nm. In addition, ZnFe2O4@TiO2 nanofibers were not only possessed the good conversion efficiency, but also shown excellent photocatalytic efficiency with magnetic properties towards the dye remediation. Prepared ZnFe2O4@TiO2 nanofibers can be considered as a promising material for energy conversion and environmental applications

Forensic DNA Analysis of mixed mosquito blood meals: STR profiling for human identification

Mosquito vectors captured at a crime scene are forensically valuable since they feed on human blood, and hence, human DNA can be recovered to help identify the victim and/or the suspect. This study investigated the validity of obtaining the human short tandem repeats (STRs) profile from mixed blood meals of the mosquito, Culex pipiens L. (Diptera, Culicidae). Thus, mosquitoes were membrane-feed on blood from six different sources: a human male, a human female, mixed human male-female blood, mixed human male-mouse blood, mixed human female-mouse blood, and mixed human male-female-mouse blood. DNA was extracted from mosquito blood meals at 2 h intervals up to 72 h post-feeding to amplify 24 human STRs. Data showed that full DNA profiles could be obtained for up to 12 h post-feeding, regardless of the type of blood meal. Complete and partial DNA profiles were obtained up to 24 h and 36 h post-feeding, respectively. The frequencies of STR loci decreased over time after feeding on mixed blood until they became weakly detectable at 48 h post-feeding. This may indicate that a blood meal of human blood mixed with animal blood would contribute to maximizing DNA degradation and thus affects STR identification beyond 36 h post-feeding. These results confirm the feasibility of human DNA identification from mosquito blood meals, even if it is mixed with other types of non-human blood, for up to 36 h post-feeding. Therefore, blood-fed mosquitoes found at the crime scene are forensically valuable, as it is possible to obtain intact genetic profiles from their blood meals to identify a victim, a potential offender, and/or exclude a suspect

Inhibition of growth of Leishmania donovani promastigotes by newly synthesized 1,3,4-thiadiazole analogs

AbstractLeishmania donovani, the causative agent of visceral leishmaniasis, is transmitted by sand flies and replicates intracellularly in their mammalian host cells. The emergence of drug-resistant strains has hampered efforts to control the spread of the disease worldwide. Forty-four 1,3,4-thiadiazole derivatives and related compounds were tested in vitro for possible anti-leishmanial activity against the promastigotes of L. donovani. Micromolar concentrations of these agents were used to study the inhibition of multiplication of L. donovani promastigotes. Seven compounds were identified with potential antigrowth agents of the parasite. Compound 4a was the most active at 50μM followed by compound 3a. These compounds could prove useful as a future alternative for the control of visceral leishmaniasis

Prevalence of anelloviruses (TTV, TTMDV, and TTMV) in healthy blood donors and in patients infected with HBV or HCV in Qatar

Background Anelloviruses (TTV, TTMV, and TTMDV) have been associated with non A-G hepatitis. The goal of the current study was to estimate the prevalence of these anelloviruses in Qatar. Methods A total of 607 blood samples (500 healthy donors, and 53 HBV-and 54 HCV-positive patients) representing different nationalities were tested for the presence of TTV, TTMV, and TTMDV DNA by nested PCR. Results Prevalence rates for the three viruses were high in all studied groups, and exceeding 95% in the HBV group (for TTV and TTMDV). Infection with more than one type of viruses was common and significant in most of the positive patients (p  0.05) albeit the detection of higher infection rates among females and Qatari subjects. Conclusion This was the first published study to look at prevalence of Anellowviruses in the Middle East. High prevalence rates of the three viruses in all studied groups was noted. Further studies are needed to explore and compare the different genotypes of these viruses in the region.This work was made possible by UREP grant # (UREP 15-015-3-006) from the Qatar National Research Fund (a member of Qatar Foundation)

SARS-CoV-2/ACE2 Interaction Suppresses IRAK-M Expression and Promotes Pro-Inflammatory Cytokine Production in Macrophages

The major cause of death in SARS-CoV-2 infected patients is due to de-regulation of the innate immune system and development of cytokine storm. SARS-CoV-2 infects multiple cell types in the lung, including macrophages, by engagement of its spike (S) protein on angiotensin converting enzyme 2 (ACE2) receptor. ACE2 receptor initiates signals in macrophages that modulate their activation, including production of cytokines and chemokines. IL-1R-associated kinase (IRAK)-M is a central regulator of inflammatory responses regulating the magnitude of TLR responsiveness. Aim of the work was to investigate whether SARS-CoV-2 S protein-initiated signals modulate pro-inflammatory cytokine production in macrophages. For this purpose, we treated PMA-differentiated THP-1 human macrophages with SARS-CoV-2 S protein and measured the induction of inflammatory mediators including IL6, TNFα, IL8, CXCL5, and MIP1a. The results showed that SARS-CoV-2 S protein induced IL6, MIP1a and TNFα mRNA expression, while it had no effect on IL8 and CXCL5 mRNA levels. We further examined whether SARS-CoV-2 S protein altered the responsiveness of macrophages to TLR signals. Treatment of LPS-activated macrophages with SARS-CoV-2 S protein augmented IL6 and MIP1a mRNA, an effect that was evident at the protein level only for IL6. Similarly, treatment of PAM3csk4 stimulated macrophages with SARS-CoV-2 S protein resulted in increased mRNA of IL6, while TNFα and MIP1a were unaffected. The results were confirmed in primary human peripheral monocytic cells (PBMCs) and isolated CD14+ monocytes. Macrophage responsiveness to TLR ligands is regulated by IRAK-M, an inactive IRAK kinase isoform. Indeed, we found that SARS-CoV-2 S protein suppressed IRAK-M mRNA and protein expression both in THP1 macrophages and primary human PBMCs and CD14+ monocytes. Engagement of SARS-CoV-2 S protein with ACE2 results in internalization of ACE2 and suppression of its activity. Activation of ACE2 has been previously shown to induce anti-inflammatory responses in macrophages. Treatment of macrophages with the ACE2 activator DIZE suppressed the pro-inflammatory action of SARS-CoV-2. Our results demonstrated that SARS-CoV-2/ACE2 interaction rendered macrophages hyper-responsive to TLR signals, suppressed IRAK-M and promoted pro-inflammatory cytokine expression. Thus, activation of ACE2 may be a potential anti-inflammatory therapeutic strategy to eliminate the development of cytokine storm observed in COVID-19 patients