Tehran University Medical Journal
Year:2020 | Volume:78 | Issue:4|Papers Count:11

Chick embryos are a great historical research model in basic and applied sciences. Along with other animal models, avian and specifically chicken embryo has been attended, as well. Avian fertilized eggs as a natural bioreactor are an efficient tool for producing recombinant proteins and vaccines manufacturing. Due to the limitations of birds' eggs for viral replication, avian stem cells culture technologies access to safe methods as well as large-scale production of a variety of human and animal vaccines. Chicken pluripotent stem cells present the unique property of self-renewal and the ability to generate differentiated progeny in all embryonic lineages such as ectoderm, mesoderm, and endoderm in vitro. For the first time, chicken embryonic stem cells (cESCs) derived from the blastodermal cells of stage X embryos in vitro. Chicken ESC provides a great model of early embryo and they are useful for gene manipulation, virus proliferation, and the generation of transgenic birds. In addition to blastodermal cells, pluripotent cell lines can be produced by reprogramming of chicken fibroblasts into induced pluripotent stem cells (iPSCs) with transcription factors such as OCT4, NANOG, SOX2, KLF4, LIN28, and C-MYC that are well known to contribute to the reprogramming of somatic cells into an iPSCs. Similar to chicken ESCs, iPSCs have properties of unlimited self-renewal in vitro and the capacity for differentiation to all three embryonic germ layers. Chicken iPSCs have been a useful tool for the production of transgenic birds and viral vaccines. Despite the benefits and multiple applications of chicken pluripotent stem cells, the propagation of these cells is limited and some important challenges should be eliminated before their use in vaccine manufacturing. It is necessary to define the appropriate culture conditions for chicken pluripotent stem cells. For example, the presence of endogenous viruses in the avian species should be evaluated for human vaccine production. Currently, primary chicken fibroblast cells are still mainly used for vaccine production. This review covers the resources to achieve chicken derived cell lines for vaccine manufacturing.

Background: Despite exist several centers of excellence in the various medical field in the country, most of them lack a single procedure and organizational structures in their functioning, organizing, targeting, etc. So the study aimed to design an organizational model that meets the goals and mission of them in the field of medical sciences. Methods: This qualitative and applied research was conducted in two comparative and analytical stages from May 2016 to February 2017 in Iran. The location of the study includes a university, research institute, health center, or research center known as a center of excellence. In the analytical stage, 10 experts and managers of the top centers were selected through a targeted sampling method as a study sample. In the comparative section, all 50 centers of excellence and similar specimens in the world were selected. The data collection tool was a semi-structured interview in the analytical section and the ministry of health's documents. In comparative section data, bases and official sites of the centers were analyzed. Results: The term "center of excellence" for units that play a role in one or two of the three dimensions of education, research, and treatment, and the term "comprehensive center of excellence" for a unit that plays a role in all three dimensions, in addition to knowledge management have been agreed upon. Seven missions (national and international) for the comprehensive center of excellence and five different missions for center of excellence were formulated. The role of the ministry of health in the guidance of these centers was agreed in the seven items. Ultimately, the macro model of organizing "comprehensive centers of excellence" and "centers of excellence" at the university level and ministry of health level was designed and presented. Conclusion: Correcting the governance structure of these centers in ministry, unit command at the highest level of management by reorganizing of duties, the authority of High Council for the Center of Excellences and the establishment of a systematic relationship between ministry and vices are the part of the requirements for fulfilling the roles and mission of center of excellence.

Background: The most common types of non-melanoma skin cancer are basal cell carcinoma (BCC), and squamous cell carcinoma (SCC). AKIEC-Actinic keratoses (Solar keratoses) and intraepithelial carcinoma (Bowen’ s disease)-are common noninvasive precursors of SCC, which may progress to invasive SCC, if left untreated. Due to the importance of early detection in cancer treatment, this study aimed to propose a computer-based model for identification non-melanoma malignancies. Methods: In this analytic study, 327 AKIEC, 513 BCC, and 840 benign keratosis images from human against machine with 10000 training dermoscopy images (HAM10000) were extracted. From each of these three types, 90% of the images were designated as the training set and the remaining images were considered as the test set. A deep learning convolutional neural network (CNN) was developed for skin cancer detection by using AlexNet (Krizhevsky, et al., 2012) as a pretrained network. First, the model was trained on the training images to discriminate between benign and malignant lesions. In comparison with conventional methods, the main advantage of the proposed approach is that it does not need cumbersome and time-consuming procedures of lesion segmentation and feature extraction. This is because CNNs have the capability of learning useful features from the raw images. Once the system was trained, it was validated with test data to assess the performance. Study was carried out at Shahid Beheshti University of Medical Sciences, Tehran, Iran, in January and February, 2020. Results: The proposed deep learning network achieved an AUC (area under the ROC curve) of 0. 97. Using a confidence score threshold of 0. 5, a classification accuracy of 90% was attained in the classification of images into malignant and benign lesions. Moreover, a sensitivity of 94% and specificity of 86% were obtained. It should be noted that the user can change the threshold to adjust the model performance based on preference. For example, reducing the threshold increase sensitivity while decreasing specificity. Conclusion: The results highlight the efficacy of deep learning models in detecting non-melanoma skin cancer. This approach can be employed in computer-aided detection systems to assist dermatologists in identification of malignant lesions.

Background: Pentoxifylline, a valuable medication with promising clinical characteristics and considerable profile of safety is used in many conditions namely chronic kidney diseases (CKD). However, the decision to prescribe pentoxifylline for anemia in CKD should be based on evidence accrued from randomized controlled trials (RCTs). Yet, substantial heterogeneity exists in studies performed to evaluate pentoxifylline therapy, particularly in relation to classification of patients, the different quality and research design, sample size, baseline parameters, clinical outcome measures, and definition of endpoints and clinically meaningful improvements. As a result, assessment of pentoxifylline in treating anemia of CKD by conducting a systematic review and meta-analysis of the published relevant clinical studies seems rational and promising. Methods: The present systematic review was done in accordance with the PRISMA guideline for systematic reviews and meta-analysis. Peer-reviewed RCTs with at least four weeks of follow-up were including in the meta-analysis. Online databases (PubMed/Medline, ISI Web of Science, Embase, and Scopus) were searched to December 2017 using selected MeSH terms related to the studied topic. Data was extracted independently by two reviewers using a standard form and then crosschecked. Statistical analyses were carrying out with Stata Software, version 7. 0 (Stata Corp., College Station, TX, USA). P value of less than 0. 05 was considered statistically significant. Data are presented as standard mean difference (SMD) and confidence interval (CI) 95%. Results: According to the predefined criteria, a total of ten studies (parallel group or crossover trials, and case-control studies) were included and screened for data extraction by two reviewers, separately. The preliminary results extracted from meta-analysis have shown that pentoxifylline can significantly increase transferrin saturation (SMD: 0. 348; CI95%: 0. 008, 0. 688), but there were no conclusive effects of pentoxifylline on hemoglobin (SMD: 0. 171; CI95%:-0. 390, 0. 732), hematocrit (SMD: 0. 466; CI95%:-1. 426, 2. 357), ferritin (SMD:-0. 010; CI95%:-0. 346, 0. 326), and administered dose of erythropoietin (SMD: 0. 114; CI95%:-0. 232, 0. 460), in pooled analyses. Conclusion: There is uncertainty about therapeutic effects of pentoxifylline on anemia of CKD patients. Since these patients has many diverse complications and receive multiple drug therapy, the results of such meta-analysis regarding outcomes of pentoxifylline therapy may have beneficial effects on rational drug prescription.

Background: Systemic sclerosis is an autoimmune disease affecting connective tissues, (including epidermal, subepidermal, microvasculature, etc. ), leading to various extent of end-organ damage. The leading cause of mortality among these patients is lung involvement. The cardiovascular events happen more frequently in patients suffering systemic scleroderma, comparing to healthy population. This study was designed to clear the correlation between development of coronary calcification (as an indicator of atherosclerosis) and lung disease in these patients. Methods: All patients with definite diagnosis of systemic sclerosis, who referred to Shahid Modarres Hospital between March 2011and March 2014, entered to the study. Patients suffering hypertension, hyperlipidemia and who had a past or current history of smoking were excluded from the study. Atherosclerosis was determined by coronary calcium score (based on Agatston score) and the severity and extent of lung disease was assessed by wells scoring system and Warrick scoring system (based on lung CT scan without contrast). The spearman correlation analysis was done on the data by SPSS software, version 20 (IBM SPSS, Armonk, NY, USA). All the patients had informed consent and no additive charge was delivered. Results: The study population consisted of 25 patients with systemic sclerosis. 21 patients were female and the 4 other ones were male. The mean age was 67± 4 years old. The mean Wells score in patients was 13± 2. 59, the mean Warrick severity score was 6. 54± 6. 16 and the mean Warrick extent score was 14. 42± 14. 59. No correlation was observed between presence of calcification in coronary arteries (Wells score r2=0. 63 P=0. 77, severity score r2=0. 27, P=0. 2, extent score r2=0. 11, P=0. 6), aorta annulus (Wells score r2=0. 04, P=0. 83, severity score r2=0. 06, P=0. 77, extent score r2=0. 06, P=0. 76) and thoracic aorta (Wells score r2=0. 05, P=0. 83, severity score r2=0. 03, P=0. 9, extent score r2=0. 03, P=0. 9) with the severity and extent of lung involvement. Conclusion: It seems that the presence of coronary atherosclerosis or calcifications in aorta annulus and thoracic aorta (assessed by Agatston calcium score) has no significant correlation with the severity and extent of lung disease (assessed by Wells and Warrick score) in patients with systemic sclerosis.

Background: Cancer is the third leading cause of death in Iran. Cancer treatment is very costly and chemotherapy drugs are one of the main causes of the high cost of cancer treatment. The purpose of this study was to evaluate the cost of chemotherapy drugs of five most common cancers and identifying the factors might affect the costs of chemotherapy drugs in a one of the large provinces of Iran, located in the center of the country. Methods: In a cross-sectional study, the data of all patients with five common cancer diagnosed from March 2015 to March 2016 in Isfahan Province in Iran were collected from the Cancer Registry Center of Isfahan, as well as the pharmacies which distribute chemotherapy drugs. The required information (including, patient characteristics, type of cancer, and the costs of chemotherapy) of patients was obtained by linking the information of patients registered in the distributor pharmacies with the patients registered at the Isfahan Cancer Registry Center through the national code of the patients. Results: Breast, skin, colorectal, stomach and thyroid cancers were the most common cancers within the evaluated period of time in Isfahan Province. Colorectal cancer with an annual average total cost of 110، 510، 720 IRR (Rials) per patient was the most expensive cancer during the evaluated time period while thyroid cancer with an annual average total cost of 40، 791، 123 IRR per patient was the least costly cancer within the evaluated time period in Isfahan among the five most common cancers, considering the chemotherapy medicines cost. The highest cost in the colorectal cancer was due to the drug cetuximab distributed under the trade name Erbitux® . Regardless of the cancer type, the mean annual total cost of chemotherapy drugs per patient within the considered period of time calculated to be 96، 307, 145 IRR. Conclusion: The chemotherapy cost of the common cancers was high with an annual average of more than 96 million IRR (Rials) per patient, within the considered time period. This was particularly true for colorectal cancer with an annual average cost of more than 110 million Rials.

Background: The mortality rate of sepsis and pneumonia is higher in end-stage renal disease (ESRD) patients than in the general population. Bacterial infections are the most common cause of hospitalization in dialysis patients and the most common source of bacteremia is vascular access in these patients. The aim of this study was to determine the prevalence of infectious causes of hospitalization in patients with endstage renal failure in Gorgan. Methods: This cross-sectional study was performed on patients with ESRD who were admitted to the 5 Azar Medical Education Center of Gorgan City during 2014 to 2016. Patients' information was collected through their clinical records and analyzed statistically. Results: The prevalence of infectious diseases in ESRD patients during the 3 years was 12. 7%, out of 100 hospitalized patients with ESRD and infectious causes, the most common type of infectious disease was catheter infection (43%) and sepsis (18%), urinary tract infection (11%) and pneumonia (8%) were the next. The most common infectious causes leading to hospitalization in men with the ESRD were catheter infection, sepsis, and pneumonia, respectively, and in women, catheter infection, sepsis, and urinary tract infection. The highest incidence of catheter infection was in the age group of 66-70 years (30. 2%), 71-75 (25. 6%), and above 71 years (25. 6%), respectively. The highest incidence of sepsis occurred in the age group of 75-71 years (38. 9%) and also the highest incidence of urinary tract infections in the age group of less than 65 years. Age (P=0. 003), sex (P=0. 01), duration of disease (P=0. 009), addiction (P=0. 01), and diabetes (P=0. 01) were the most common risk factors for infectious diseases in patients with ESRD. Conclusion: The results of this study showed that catheter infection is the most common cause of infection in patients with end-stage renal disease (ESRD). Therefore, avoiding multiple vascular manipulations, disinfection of the catheter, timely replacement, and training of dialysis staff are effective in reducing catheter infections.

Background: Medical errors are those errors or mistakes committed by healthcare professionals due to errors of omission, errors in planning, and errors of execution of a planned healthcare action whether or not it is harmful to the patient. Medical error in hospitals increases morbidity and mortality and decreases patient satisfaction and hospital productivity. This study aimed to determine the prevalence of medical errors in Iranian hospitals. Methods: This study was conducted using systematic review and meta-analysis approaches. All articles written in English and Persian on the prevalence of medical errors in Iranian hospitals up to March 2019 were searched in Web of Science, PubMed, Elsevier, Scopus, Magiran, IranMedex and Scientific Information Database (SID) databases, and Google and Google Scholar search engines. In addition, reference lists of the retrieved papers were hand-searched. A total of 9 studies matching the inclusion criteria were identified, reviewed, and analyzed using comprehensive metaanalysis software. Results: The prevalence of medical errors was reported in 9 studies and prevalence rate ranged from 0. 06% to 42%. Most studies used reporting forms completed by hospital employees for determining the prevalence of medical errors (67%). Only three studies collected data by reviewing patients’ medical records. Accordingly, the overall prevalence of medical error in Iran's hospitals based on the nine published articles was 0. 01% (95% Cl 0%-0. 01%) during 2008 to 2017. The highest medical error was recorded in a hospital in Shiraz, 2. 1% (95% Cl: 1. 4%-2. 7%) in 2012. A significant statistical correlation was observed between medical errors and sample size (P<0. 05). Conclusion: The prevalence rate of medical error in Iran is low. It is strongly recommended to use more advanced and valid methods such as occurrence reporting, screening, and the global trigger tool for examining medical errors in Iranian hospitals. Proving adequate education and training to patients and employees, simplifying and standardizing hospital processes, enhancing hospital information systems, improving communication, promoting a safety culture, improving employees’ welfare and satisfaction, and implementing quality management strategies are useful for reducing medical errors.

Background: The empty sella syndrome (ESS) is a neurological or pathologic finding in which sella turcica is devoid of pituitary tissue and the subarachnoid space extends into sella turcica, which is either primary or secondary as well as partial and complete. The widespread use of CT scans and MRIs today has made the ESS a common finding in imaging. The aim of this study was to evaluate the prevalence of the empty sella syndrome. Methods: This is a retrospective descriptive-analytic study in which all patients referred to Imam Ali Hospital (Zahedan) for electromagnetic brain imaging (n=1856) were recruited by cross-sectional sampling during the first 6 months from 21 March 2018 to 23 September 2018. Inclusion criteria included the absence of another known problem in the central nervous system and the absence of concurrent underlying disease. The data gathering tool was a questionnaire consisting of demographic and related variable to empty sella disorder. Results: The results of this study showed that the prevalence of empty sella was 8. 2% with a mean age of 37. 02± 12. 51 years. 66. 4% of the patients were female. The prevalence of primary empty sella was 78. 9% with a mean age of 34. 51± 11. 26 years. 71. 7% of the patients had partial empty sella. There was a significant difference between the mean age and sex of patients with empty sella and non-empty sella subjects (P=0. 008) and (P<0. 0001). There was a statistically significant difference between the mean age of affected patients with type of empty sella (P<0. 0001). There was no statistically significant difference between mean age of patients with empty sella and severity of empty sella (P=0. 056). There was no significant difference between the frequency of empty sella type and the severity with gender (P=0. 224) and (P=0. 091). Conclusion: The findings of this study indicated that the overall prevalence of empty sella in the referring patients was relatively low. Most of them were females with primary type and minor severity.

Background: The ineffectiveness of hemodialysis fistulas causes high costs and increases mortality and morbidity rates. The efficacy of drug-coated balloon and nondrug-coated balloon in dysfunctional arteriovenous Fistula was evaluated over six month period. Methods: In this randomized clinical trial, a total of a total of 50 hemodialysis patients who referred to Imam Reza Hospital in Kermanshah for failing of arteriovenous fistula in 2018 year, were randomly divided into two separate groups of drug-coated balloon angioplasty and non-drug coated balloon angioplasty. All of these procedures were done with the same surgeon. Patients were followed-up for 6 months. Variables and data of patients like age, gender, diabetes mellitus, hypertension, and location of arteriovenous fistula were documented and analyzed by SPSS software, version 21 (SPSS Inc., Chicago, IL, USA) using statistical tests. T-test and chi-square test were used for data analysis and the significance level was considered less than 0. 05. Results: The success rate of drug-coated balloon angioplasty versus plain balloon angioplasty in the efficacy of arteriovenous fistulas increased significantly (19 vs. 6 and 13 vs. 12, respectively, P<0. 05). There is also a significant relationship between age and diabetes over the lifetime of the arteriovenous fistula. According to results, the efficacy of arteriovenous fistula in the elderly patients (>65 years) and the diabetes mellitus patients were lower than other risk factors causing end-stage renal disease. Conclusion: According to the results of this study, the use of drug-coated balloons rather than non drug-coated balloon is more effective in the efficiency of arteriovenous artery fistula.