34 research outputs found

    Development of PLGA-coated β-TCP scaffolds containing VEGF for bone tissue engineering

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    Bone tissue engineering is sought to apply strategies for bone defects healing without limitations and short-comings of using either bone autografts or allografts and xenografts. The aim of this study was to fabricate a thin layer poly(lactic-co-glycolic) acid (PLGA) coated beta-tricalcium phosphate (β-TCP) scaffold with sustained release of vascular endothelial growth factor (VEGF). PLGA coating increased compressive strength of the β-TCP scaffolds significantly. For in vitro evaluations, canine mesenchymal stem cells (cMSCs) and canine endothelial progenitor cells (cEPCs) were isolated and characterized. Cell proliferation and attachment were demonstrated and the rate of cells proliferation on the VEGF released scaffold was significantly more than compared to the scaffolds with no VEGF loading. A significant increase in expression of COL1 and RUNX2 was indicated in the scaffolds loaded with VEGF and MSCs compared to the other groups. Consequently, PLGA coated β-TCP scaffold with sustained and localized release of VEGF showed favourable results for bone regeneration in vitro, and this scaffold has the potential to use as a drug delivery device in the future

    Prevalence and Risk Factors of Retinopathy of Prematurity in Iran

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    Purpose: The present study aimed to evaluate the frequency and risk factors of retinopathy of prematurity (ROP) among Iranian infants. Methods: A retrospective cohort study was conducted on infants who had undergone screening for ROP at Farabi Eye Hospital, between March 2016 and March 2017. Data were analyzed based on the presence of extreme prematurity (gestational age ≤ 28 weeks), extremely low-birth-weight (≤ 1000 g), and multiplegestation (MG) infants. Results: The prevalence of ROP was 27.28% (n = 543) among all screened infants, 74.4% for extremely preterm (EP) infants, 77.5% for extremely low birth weight (ELBW) babies, and 27.25% for infants from MG pregnancies. On multivariate analysis, gestational age, birth weight, and history of transfusion (P < 0.0001, P < 0.0001, and P = 0.04, respectively) were found to be significantly associated with ROP. More advanced stages of ROP (P < 0.0001) were observed in EP and ELBW infants. Birth weight (P = 0.088), history of transfusion (P = 0.066), and intubation (P = 0.053) were not associated with increased risk of ROP in EP infants, while gestational age (P = 0.037) and history of transfusion (P = 0.040) were significant risk factors for ROP in ELBW infants. Gestational age (P < 0.001) and birth weight (P = 0.001) were significantly associated with ROP in infants from MG pregnancies in multivariate analysis. Conclusion: ROP remains a commonly encountered disease, especially in ELBW and EP infants. The history of transfusion may have a role in stratifying the risk for ROP and guiding future screening guidelines

    Design and implementation of the canadian kidney disease cohort study (CKDCS): A prospective observational study of incident hemodialysis patients

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    <p>Abstract</p> <p>Background</p> <p>Many nephrology observational studies use renal registries, which have well known limitations. The Canadian Kidney Disease Cohort Study (CKDCS) is a large prospective observational study of patients commencing hemodialysis in five Canadian centers. This study focuses on delineating potentially reversible determinants of adverse outcomes that occur in patients receiving dialysis for end-stage renal disease (ESRD).</p> <p>Methods/Design</p> <p>The CKDCS collects information on risk factors and outcomes, and stores specimens (blood, dialysate, hair and fingernails) at baseline and in long-term follow-up. Such specimens will permit measurements of biochemical markers, proteomic and genetic parameters (proteins and DNA) not measured in routine care. To avoid selection bias, all consenting incident hemodialysis patients at participating centers are enrolled, the large sample size (target of 1500 patients), large number of exposures, and high event rates will permit the exploration of multiple potential research questions.</p> <p>Preliminary Results</p> <p>Data on the baseline characteristics from the first 1074 subjects showed that the average age of patients was 62 (range; 50-73) years. The leading cause of ESRD was diabetic nephropathy (41.9%), and the majority of the patients were white (80.0%). Only 18.7% of the subjects received dialysis in a satellite unit, and over 80% lived within a 50 km radius of the nearest nephrologist's practice.</p> <p>Discussion</p> <p>The prospective design, detailed clinical information, and stored biological specimens provide a wealth of information with potential to greatly enhance our understanding of risk factors for adverse outcomes in dialysis patients. The scientific value of the stored patient tissue will grow as new genetic and biochemical markers are discovered in the future.</p

    Behavioural and Developmental Interventions for Autism Spectrum Disorder: A Clinical Systematic Review

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    Background: Much controversy exists regarding the clinical efficacy of behavioural and developmental interventions for improving the core symptoms of autism spectrum disorders (ASD). We conducted a systematic review to summarize the evidence on the effectiveness of behavioural and developmental interventions for ASD. Methods and Findings: Comprehensive searches were conducted in 22 electronic databases through May 2007. Further information was obtained through hand searching journals, searching reference lists, databases of theses and dissertations, and contacting experts in the field. Experimental and observational analytic studies were included if they were written in English and reported the efficacy of any behavioural or developmental intervention for individuals with ASD. Two independent reviewers made the final study selection, extracted data, and reached consensus on study quality. Results were summarized descriptively and, where possible, meta-analyses of the study results were conducted. One-hundred-and-one studies at predominantly high risk of bias that reported inconsistent results across various interventions were included in the review. Meta-analyses of three controlled clinical trials showed that Lovaas treatment was superior to special education on measures of adaptive behaviour, communication and interaction, comprehensive language, daily living skills, expressive language, overall intellectual functioning and socialization. High-intensity Lovaas was superior to low-intensity Lovaas on measures of intellectual functioning in two retrospective cohort studies. Pooling the results of two randomized controlle

    The effect of 17β-estradiol on gene expression of calcitonin gene-related peptide and some pro-inflammatory mediators in peripheral blood mononuclear cells from patients with pure menstrual migraine

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    Objective(s):The neuropeptide calcitonin gene-related peptide (CGRP) has long been postulated to play an integral role in the pathophysiology of migraine. Earlier studies showed that CGRP can stimulate the synthesis and release of nitric oxide (NO) and cytokines from trigeminal ganglion glial cells. The purpose of this study was to determine the effect of 17β-estradiol in regulation of CGRP expression, inducible nitric oxide synthase (iNOS) activity, and NO and interleukin-1beta (IL-1β) release in cultured peripheral blood mononuclear cells (PBMCs) from patients with pure menstrual migraine and healthy individuals. Materials and Methods: This study was performed on twelve patients with pure menstrual migraine and twelve age-and sex-matched healthy individuals. PBMCs treated with 17β-estradiol for 24 hr at physiological and pharmacological doses. Gene expression was evaluated by real time-PCR. CGRP and IL-1β proteins in culture supernatant were determined by ELISA method. Activity of iNOS in PBMCs and total nitrite in the culture supernatant were measured by colorimetric assays. Results:Treatment with 17β-estradiol had a biphasic effect on expression of CGRP. We found that 17β-estradiol treatment at pharmacological dose significantly increases mRNA expression of CGRP in both groups (

    Idiopathic macular telangiectasia type 2: A six-year study with multimodal imaging of a presumed unilateral case

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    Purpose: To present a rare manifestation of macular telangiectasia type 2 (MacTel type 2) followed up for over six years. Methods: A 61-year-old woman with one year history of blurred vision of her left eye was referred. Results: Whereas the funduscopy, spectral-domain optical coherence tomography (SD-OCT), fluorescein angiography (FA), and fundus autofluorescence (FAF) were normal in the right eye, they revealed noticeable findings typical of MacTel type 2 in the left eye. After over six years follow-up, OCT-angiography (OCTA) showed no remarkable difference between the two eyes, and en face OCT showed subtle abnormal change in the right eye as well as typical pathological changes in the left eye. Conclusion: MacTel type 2 can present unilaterally and remain so for a long time. The role of multimodal imaging in diagnosis and follow-up is of utmost importance. Keywords: Unilateral, Macular telangiectasia type 2, Multimodal imagin

    Comparison of intravitreal bevacizumab injection and laser photocoagulation for type 1 zone II retinopathy of prematurity

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    Purpose: To compare the efficacy of intravitreal bevacizumab (IVB) injection with conventional laser photocoagulation in eyes with type 1 zone II retinopathy of prematurity (ROP). Methods: Preterm infants with type 1 ROP in zone II (stage 2 or 3 ROP with plus disease) were randomly assigned to intravitreal injection of 0.625 mg/0.025 ml bevacizumab (Group 1) or laser photocoagulation (Group 2). Patients were followed weekly for 4 weeks and then biweekly till 90 weeks gestational age. Also, spherical and cylindrical refractive errors were compared at 90 weeks postmenstrual age (PMA). Results: A total of 116 preterm infants (232 eyes) were treated and completed the follow-up period. IVB injection was done in 154 eyes (77 cases), and laser photocoagulation was done in 78 eyes (39 cases). ROP regressed after single IVB injection in 149 eyes (96.8%) and in 5 eyes (3.2%) after the second injection. Cataract developed in one eye (0.63%) after IVB injection. ROP regressed in 94.7% of treated eyes (76 eyes) in the laser photocoagulation group; however, retinal fold and traction developed in 2 eyes. Spherical and also cylindrical refractive errors had no significant difference. Conclusions: Both IVB injection and laser photocoagulation are effective methods for the treatment of type 1 zone II ROP. However, re-treatment requirement may be higher in the IVB injection group. IVB re-injection is an effective option for re-treatment in persistent cases. Keywords: Retinopathy of prematurity, Bevacizumab, Avastin, Laser photocoagulation, Zone I

    Analysis of the safety effectiveness of methane gas valve pits: A Case Study in the Steel Industry Based on Hazardous Areas Classification

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    Introduction: Methane is one of the most widely used gases in industries with a high flammability potential. This study aimed to evaluate the efficiency of ventilation systems installed on methane valve pits based on hazardous areas classification. Material and Methods: This study was implemented in a steel industry in Qom Province in 2019. The tools used in this study were a DELTA OHM pitot tube (DO-2003) to measure wind speed, EPA Protocol for equipment leak emission estimates (U.S. Environmental Protection Agency) and IEC-60079-10 for evaluating the safety of ventilation of methane valve pits. Results: The methane LELm was about 0.0334 kg/m3, and the volume of the release area was approximately VZ = 0.053 m3. The expected leak emissions were within the Vz < 0.1 m3 range. The ventilation system embedded on methane distribution pipelines was not effective for openings with diameters of more than 0.3 mm and the volume of gas inside the valve pits would quickly exceed high ventilation border which might lead to a dangerous accumulation of gas in the valve pits. Conclusion: Given that a very small opening or leak in gas transmission valves may lead to the formation of an explosive atmosphere, it is essential to monitor methane before entering the valve pit area and performing any operations on valve pits

    Efficacy of intravitreal bevacizumab for the treatment of Zone I Type 1 retinopathy of prematurity

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    Purpose: To describe the efficacy of intravitreal bevacizumab for the treatment of type 1 retinopathy of prematurity (ROP) in zone I. Methods: Preterm infants with type 1 ROP in zone I (zone I ROP, any stage with plus disease or zone I ROP, stage 3 without plus disease) were enrolled in this prospective study. Intravitreal bevacizumab (0.625 mg/0.025 ml) was injected under topical anesthesia. Patients were followed weekly for 4 weeks and then biweekly till 90 weeks gestational age. Results: Seventy eyes of 35 patients with type 1 ROP in zone I were enrolled. At a gestational age of 90 weeks, ROP regressed with complete or near-complete peripheral retinal vascularization, in 82.9% of eyes after a single injection and in 92.9% of eyes after up to two injections. In five eyes (7.1%), ROP progressed to stage 4B or 5, so surgical management was required. There were no major complications such as endophthalmitis, cataract, or vitreous hemorrhage after injection. Conclusion: Intravitreal bevacizumab injection is an effective method for the management of patients with Zone I ROP requiring treatment; however, some cases may progress to more advanced stages and require surgical management. Close monitoring for recurrence or progression is necessary. Eyes with persistent zone I ROP may progress to advanced stages when treated with intravitreal bevacizumab injection and re-treatment may be needed
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