39 research outputs found

    Aging changes in the retina of male albino rat: a histological, ultrastructural and immunohistochemical study

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    Background: Degenerative changes caused by aging may affect the eye, especially the retina. Such changes occur as a part of normal physiological process and may be irreversible. The aim of the study was to demonstrate the influence of aging on the morphology of the retina to provide a basis to explain the pathogenesis of age-associated decline in visual acuity, scotopic and photopic sensitivity.  Materials and methods: Forty male albino rats were used and divided into four age groups (group I: age of cortical maturity, group II: middle-aged, group III: aged group and group IV: senile group). The rats were sacrificed, the eye balls were enucleated. Intra-vitreal injections of formalin for haematoxylin and eosin and immunohistochemical sections, glutaraldehyde for toluidine blue semithin and E/M ultra-thin sections were performed. Measurements and quantitative histomorphometric estimation of the layers of the retina were done.  Results: Light microscopic examination revealed age-dependent attenuation of photoreceptor striations. Aged and senile groups presented pyknotic, widely- -spaced nuclei of the outer nuclear layer. The inner nuclear layer was thinned out to 2 or 3 cellular rows. Retinal capillaries showed progressive dilatation and congestion. Statistical analysis proved significant thinning of the retina with variable degrees of thinning of the constituting layers. Decreased arborisation with age was confirmed with quantification of synaptophysin-immunostained sections. Glial fibrillary acidic protein immunostaining revealed the picture of reactive gliosis. On the ultrastructural level, the retinal pigment epithelium exhibited major alterations with aging. Numerous phagosomes, lipofuscin and melanolipofusin granules appeared within the cells, together with exaggerated basal infoldings. The pho- toreceptor nuclei became degenerated and the perinuclear space was widened. Conclusions: Rat retinae clearly undergo age-related morphological changes. Such changes provide a cellular base for explanation of decreased vision in humans with aging other than reflection errors. Effect of aging was not only qualitative, but also quantitative

    FIRST Framework Design and Facilitate Active Deep Learner eXperience

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    Over the past decades, Learning & Development has become an area of growing interest and constant research. As a result, there is an abundance of studies and models that target the development of educators. However, the professional development of educators should be built on a comprehensive framework of research-based instructional strategies that help train them on how to understand, experience, practice and leave a sustainable impact on learners. This paper presents our own “FIRST Framework”, a holistic framework designed on the basis of renown models and theories, such as: experiential learning; Gamification and game-based learning; facilitative learning, 6Ds model, positive psychology, experience economy and neuroscience. It is an engaging framework that helps educators bridge theory and practice to create high-quality learning environment in their classrooms. FIRST Framework consists of 5 domains with 15 principles that help leave sustainable impact on learners through promoting Active Deep Learner Experience

    Long-term protection of hepatitis B vaccination among Egyptian children

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    Background: Hepatitis B Vaccination is the most effective way to prevent transmission of hepatitis B virus (HBV). Objective: to detect the long-term immunogenicity of the vaccine in Egyptian children after five and ten years of vaccination. Methods: Two hundreds healthy children were recruited. They were divided into two groups according to their age. Group A included 100 child, around 6 years old, vaccinated 5 years ago. Group `B` included 100 child, around 11 years old, vaccinated 10 years ago. Hepatitis B surface antibody (HBsAb) titre was tested, booster dose of the vaccine was given to children whose HBsAb was < 10 mIU/ml, then one and half month later, they were retested for HBsAb to evaluate the response. Results: Both groups had a wide range of HBsAb (2-1000 mlU/ml), and there was a significant difference in the level of the two groups. Our data proves the decline of antibody titre with time. In group A, 19 children needed a booster dose, 14 of them were vaccinated, and 10 were retested after one and half month. The results showed that 9 (90%) responded by increased level of HBsAb, with six (66.6%) showing an adequate response. In group B, 52 children had antibody titre < 10, 48 of them were vaccinated and 34 were retested one and half months later. Two out of the 34 did not respond and 32 (94.2%) responded by an increase in the antibody titre. Of those who responded, 19 had adequate response (HBsAb ≄ 100) and 13 had hypo-response (HBsAb = 10 -100). Eighty percent (80%) of boys versus 51.7% of girls responded adequately. Conclusion: Hepatitis B vaccine is an effective and successful way for preventing HBV infection. No need for booster dose at least for 5 years after vaccination .Keywords: HBV- HB vaccine- long term immunityEgypt J Pediatr Allergy Immunol 2011;9(1):35-4

    Surgical Intervention for Moderate Ischemic Mitral Regurge During Coronary Revascularization (Comparative Study)

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    Abstract: Background: Ischemic mitral regurgitation is a common clinical problem of coronary artery disease (CAD), developing acutely after myocardial infarction in up to 19 % of patients. For patients with ischemic mitral regurgitation (IMR), it is not clear whether adjunctive mitral valve (MV) repair at the time of coronary artery bypass graft surgery (CABG) is beneficial. Objective: To compare the outcome of patients with moderate ischemic mitral regurgitation , those surgically corrected at time of coronary artery bypass grafting either by repair or replacement, versus those treated by coronary artery bypass grafting alone. Patients and methods: Between October 2009 and October 2011, a cohort of sixty patients with ischemic heart disease associated with moderate ischemic mitral regurgitation. The study was carried out in the department of cardiothoracic surgery of Al Azhar University and Nasr Institute. All patients had CAD with moderate IMR and were admitted for CABG combined with mitral repair versus CABG alone. Results: After our study evaluation, we found that patients who were offered the combined approach of CABG with repair, showed more improvement as regard to clinical and echocardiographic parameters, compared to those who were offered the CABG alone procedure. We also found that a worse preoperative left ventricle (LV) function is a risk factor to the persistence or progression of the IMR grades in the CABG only patients. Conclusion: We concluded that the MV repair procedure done in our first group patients offered some protection against the persistence or progression of the IMR grades

    Is there a Link between Human Herpes Virus Infection and Toll-like Receptors in the Pathogenesis of Pityriasis Rosea? A Case-control Study

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    Human herpesvirus (HHV) 6 and 7 are involved in the pathogenesis of pityriasis rosea (PR). Our aim was to evaluate the role of the innate immune response in PR through the detection of Toll-like receptors (TLR) 2, 3, 4, 7, 8, and 9 expression in the skin of affected patients and to detect the possibility of being induced by HHV-6 and/or HHV-7 viral coexistence in these patients. Twenty-four patients with PR and 24 healthy controls were included in this case-control study. Biopsy was obtained from the PR lesion and from the healthy skin of controls for detection of HHV-6 and 7 as well as TLRs 2, 3, 4, 7, 8, and 9 gene expression using real-time polymerase chain reaction (PCR). Significantly elevated expression of all studied TLRs and significantly higher viral load of HHV-6 and 7 in PR cases were detected. A significant higher expression of TLR2 and 4 in HHV-7 positive cases and a significant positive correlation between TLR9 and HHV-7 viral load were documented. HHV6 and 7 may also be involved in the pathogenesis of PR via TLR pathways  </p

    Pulmonary embolism versus pulmonary vasculitis in Hughes-Stovin syndrome: Characteristic computed tomography pulmonary angiographic findings and diagnostic and therapeutic implications. HSS International Study Group

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    Background and aim: Hughes-Stovin syndrome (HSS) is a rare systemic vasculitis with widespread venous/arterial thrombosis and pulmonary vasculitis. Distinguishing between pulmonary embolism (PE) and in-situ thrombosis in the early stages of HSS is challenging. The aim of the study is to compare clinical, laboratory, and computed tomography pulmonary angiography (CTPA) characteristics in patients diagnosed with PE versus those with HSS. Methods: This retrospective study included 40 HSS patients with complete CTPA studies available, previously published by the HSS study group, and 50 patients diagnosed with PE from a single center. Demographics, clinical and laboratory findings, vascular thrombotic events, were compared between both groups. The CTPA findings were reviewed, with emphasis on the distribution, adherence to the mural wall, pulmonary infarction, ground glass opacification, and intra-alveolar hemorrhage. Pulmonary artery aneurysms (PAAs) in HSS were assessed and classified. Results: The mean age of HSS patients was 35 ± 12.3 years, in PE 58.4 ± 17 (p &lt; 0.0001). Among PE 39(78 %) had co-morbidities, among HSS none. In contrast to PE, in HSS both major venous and arterial thrombotic events are seen. Various patterns of PAAs were observed in the HSS group, which were entirely absent in PE. Parenchymal hemorrhage was also more frequent in HSS compared to PE (P &lt; 0.001). Conclusion: Major vascular thrombosis with arterial aneurysms formation are characteristic of HSS. PE typically appear loosely-adherent and mobile whereas “in-situ thrombosis” seen in HSS is tightly-adherent to the mural wall. Mural wall enhancement and PAAs are distinctive pulmonary findings in HSS. The latter findings have significant therapeutic ramifications.</p

    Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

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    BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P &lt; 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P &lt; 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

    A novel chitosan 3-amino-1,2,4-triazole hybrid: Preparation and its effects on cotton fabric properties

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    A hybrid of chitosan and 3-amino-1,2,4-triazole was prepared using the semi-wet method, which allows for the adsorption of the triazole molecules on the chitosan surface. Moreover, an easy method for applying this hybrid to cotton fabric was established. The tensional strength, uniformity and compatibility of the hybrid components in forming of a strong film were studied using different variables, including the chitosan 3-amino-1,2,4-triazole ratio, fixation temperature and time. The loading of the hybrid onto the fabric in the absence and presence of cross linker (butane tetra carboxylic acid) was also studied. The best conditions for preparing the hybrid was a 1:4 molar ratio of chitosan to 3-amino-1,2,4-triazole at 60 °C for 240 min, and those for the application of the hybrid to cotton fabric were a 1:1 molar ratio at 150 °C with a 5 min curing time. Both hybrid and treated cotton fabrics were characterized using FTIR, SEM, TGA, and DSC as well as the nitrogen content and tensional strength of the treated cotton. Finally, the antibacterial activities of the treated cotton fabric display 100% activity and excellent effects against gram-positive bacteria, Staphylococcus aureus and gram-negative Escherichia coli
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