Effect of mesenchymal stem cells with platelet-rich plasma carriers on bone formation after rapid maxillary expansion: An Animal Study.

OBJECTIVE: To evaluate the effect of bone mesenchymal stem cells (BMSCs) with or without platelet-rich plasma (PRP) carriers on sutural new bone formation after rapid palatal expansion (RPE). SETTINGS AND SAMPLE POPULATION: Sixty male Wistar rats were used in this study. MATERIAL AND METHODS: All samples were subjected to 50cN of palatal expansion force for 7 days followed by 3 weeks of the retention period. The experimental groups received a single-dose injection of the specified solution at the time of retainer placement (BMSCs, PRP, BMSCs+PRP, normal saline). BMSCs used in this study were marked with the green fluorescent protein (GFP). New bone formation (NBF) in the sutural area was evaluated by µCT and occlusal radiography. In addition, semi-quantitative analyses were performed on histology images to analyse the quality of sutural bone, connective tissue and vascularization. Immunohistochemistry analyses were conducted for osteocalcin and collagen type I proteins. RESULTS: After the 21-day retention period, limited GFP marked cells were detected around the sutural area. Samples treated with BMSCs + PRP had the highest NBF and showed higher expression of collagen type I and osteocalcin. CONCLUSION: Injecting BMSCs + PRP may increase sutural bone density significantly. However, injecting BMSCs or PRP carriers alone did not affect sutural bone density.

Knowledge production in Iranian social determinants of health research centers: Toward health equity.

Background: As the partner country of the WHO Commission on Social Determinants of Health (SDH), Iran has expanded the knowledge based on the social determinants of health- as one of commission recommendations- by establishing SDH research centers to collect evidence and design responses to the existing health equity gap. Considering the importance of the role assigned to these research centers, this study aimed to present the knowledge production of SDH research centers and determine their status in Iran's health research system (HRS). Methods: In this cross sectional study, research performance of SDH research centers was assessed based on international research indicators and compared with national medical research centers and HRS knowledge production. Then, SDH research centers were scored and ranked based on the research indicators. Results: Out of 37 approved SDH research centers, the knowledge performance of 33 research centers was reviewed. The total number of academic members was 334. The number of these centers' indexed published articles and the proportion of published articles per academic member have been doubled from 483 and 1.44 in 2015 to 984 and 2.94 in 2017. In this period, the number of citations of the past 5-year publications was 4355 according to Scopus database. The proportions of these centers' high-quality publication (Q1) and international collaborations per published articles were 14.8 and 8.25. In ranking, the first to third ranks were occupied by SDH research centers of Kermanshah, Kurdistan, and Qazvin Universities of Medical Sciences. Conclusion: Although knowledge production seems desirable in mentioned research centers, it is essential to create a virtual research network to increase intersectoral collaboration and develop strategies to solve the puzzle of gathering evidence on the social determinants affecting health inequities.

Generation of Fam83h knockout mice by CRISPR/Cas9-mediated gene engineering.

Family with sequence similarity 83 member H (FAM83H) protein-coding geneplay an essential role in the structural organization, calcification of developing enamel, and keratin cytoskeleton disassembly by recruiting Casein kinase 1 alpha (CSNK1A1) to keratin filaments. In this study, we have applied CRISPR Cas9 nickase (D10A) to knockout (KO) the Fam83h gene in NMRI outbred mice. We generated homozygous Fam83h KO mice ( Fam83h Ko/Ko ) through a premature termination codon, which was validated by Sanger sequencing in F0 generation. Next, we also bred the FAM83H KO for two generations. Reverse-transcription polymerase chain reaction and Western blot analysis approved the Fam83h KO mice. The Fam83h KO mice had evidence of normal morphology at the cervical loops, secretory and maturation stages, and mandibular molars. In comparison with the normal wild-type mice ( Fam83h W/W ), the F2 homozygous KO ( Fam83h Ko/Ko ) had sparse, scruffy coats with small body size and decreased general activity. Also, they had the natural reproductive ability and natural lifespan. In addition, delay in opening the eyes and dry eyes among infant mice were seen. The F1 heterozygous mice looked comparable to the normal wild-type mice ( Fam83h W/W ), which showed autosomal recessive inheritance of these phenotypes. The KO of FAM83H had controversial effects on the development of teeth and the formation of enamel. The phenotype defect in dental development and the enamel formation were seen in three mice among four generations. It can be concluded that null FAM83H in outbred mice not only showed the reported phenotypes in null inbred mouse but also showed normal lifespan and reproductive ability; dental deficiency in three homozygous mice; and the symptoms that were similar to the symptoms of dry eye syndrome and curly coat dog syndrome in all four evaluated KO generations.

Forced expression of Hnf1b/Foxa3 promotes hepatic fate of embryonic stem cells.

Embryonic stem (ES) cell-derived hepatocytes have the potential to be used for basic research, regenerative medicine, and drug discovery. Recent reports demonstrated that in addition to conventional differentiation inducers such as chemical compounds and cytokines, overexpression of lineage-specific transcription factors could induce ES cells to differentiate to a hepatic fate. Here, we hypothesized that lentivirus-mediated inducible expression of hepatic lineage transcription factors could enhance mouse ES cells to hepatocyte-like cells. We screened the effects of candidate transcription factors Hnf1b, Hnf1a, Hnf4a, Foxa1, Foxa3 and Hex, and determined that the combination of Hnf1b/Foxa3 promoted expression of several hepatic lineage-specific markers and proteins, in addition to glycogen storage, ICG uptake, and secretion of albumin and urea. The differentiated cells were engraftable and expressed albumin when transplanted into a carbon tetrachloride-injured mouse model. These results demonstrated the crucial role of Hnf1b and Foxa3 in hepatogenesis in vitro and provided a valuable tool for the efficient differentiation of HLCs from ES cells.

Evaluating the role of maternal folic acid supplementation in modifying the effects of methylenetetrahydrofolate reductase (C677T and A1298C) gene polymorphisms in oral cleft children.

BACKGROUND: We studied the role of maternal folic acid supplementation in modifying the effects of methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) gene polymorphisms in Iranian children with oral clefts. MATERIALS AND METHODS: Forty-seven newborn infants with orofacial cleft and their mothers were selected randomly. Mothers were matched regarding dietary folate intake. The genotyping on venous blood was carried out. Consistency between maternal and child genotypes was analyzed. RESULTS: Genotype consistency was not statistically significant in both C677T and A1298C gene variants (P > 0.05). CONCLUSION: Maternal folic acid consumption may not have any significant effect on modifying C677T and A1298C polymorphisms in children.

Evaluation of Seroconversion Rate Following SARS COV 2 Vaccination in Health Care Workers at Shahid Beheshti University of Medical Sciences.

Background: Vaccines are the most effective way to prevent Coronavirus 2 severe acute respiratory syndrome (SARS-CoV-2). This study examines and compares the efficiency of AstraZeneca, Sinopharm, and Sputnik vaccines and the correlation of antibody response with age, sex, and history of corona disease in employees of Shahid Beheshti University of Medical Sciences. Methods: 202 participants were included, of which 82 were administered the Astra-Zeneca, 59 were given the Sinopharm, and 61 were given the Sputnik vaccine. SARSCoV-2 IgM and IgG antibody levels were checked four weeks after passing the second dose of all three vaccines using the enzyme-linked immunosorbent assay (ELISA) technique. Results: There was no significant difference between the amount of IgM and IgG antibodies among three vaccines (p=0.056). For all three vaccines, gender and age did not significantly affect the amount of IgM and IgG antibodies. The history of infection with COVID-19 increased the antibody response (p>0.5). Conclusion: The titer of IgM and IgG antibodies were not statistically significantly different. The IgM and IgG antibodies produced by vector-based vaccines are higher than the Sinopharm vaccine. Gender did not affect the produced antibody titer. No significant linear relationship was found between age and antibody titer. In people from this study who received two doses of the AstraZeneca vaccine and had a corona history, the average amount of both IgM and IgG antibodies was measured more than the other participants.

Association of MMP2 and MMP9 gene polymorphisms with nonsyndromic cleft lip/palate in an Iranian population.

Background: Cleft lip/palate (CL/P) is a prevalent congenital disorder. Matrix metalloproteinases (MMPs) play a role in palatogenesis and have been proposed to be associated with nonsyndromic CL/P development. This study aimed to examine the association of MMP2 (rs243866) and MMP9 (rs3918242) gene polymorphism with nonsyndromic CL/P in an Iranian population. Methods: Blood samples were collected from 120 nonsyndromic CL/P patients and 140 healthy newborns in this case-control study. DNA extraction was performed by the salting-out method, and the samples underwent polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), using Pag and SphI enzymes, for genotyping MMP2 and MMP9 gene polymorphisms. Statistical analysis was performed with SPSS 11.5. Univariate and multivariate logistic regression models were used to calculate the odds ratios and 95% confidence intervals (CIs). The level of statistical significance was set at P<0.05. Results: No significant association was found between MMP2 gene polymorphism and nonsyndromic CL/P. However, the MMP9 gene polymorphism had a significant association with nonsyndromic CL/P, with a higher prevalence of the T allele and TT genotype in the case group than the control group. Conclusion: This study indicated a potential link between MMP9 gene polymorphism and nonsyndromic CL/P in an Iranian population. Future investigations with greater sample diversity and larger sample sizes are required to obtain more comprehensive and robust evidence. In-depth analyses and studies involving different ethnic groups can further enhance our understanding of the genetic underpinnings of CL/P.

Detection of a rare AXIN2 variant in an Iranian family with hypodontia and oligodontia.

Background. Hypodontia, or the absence of one or more teeth during tooth formation, is a highly prevalent dental anomaly. Nevertheless, the main causes are still unknown. Mutations in PAX9, MSX1, WNT10A, and AXIN2 genes are most commonly associated with non-syndromic tooth agenesis in the literature. This study investigated these candidate genes in an Iranian family with non-syndromic hypodontia and oligodontia. Methods. Peripheral blood samples of the proband and her family members were collected, and DNA extractions using the salting-out method were carried out. In addition, polymerase chain reaction (PCR) and Sanger sequencing for candidate genes were performed. Results. A missense variant (rs4904210) was identified in the PAX9 gene, with one heterozygous missense variant (rs2240308) and one stop-gained variant (rs121908568) in the AXIN2 gene. Conclusion. By surveying similar studies and analyzing the variant in bioinformatics websites, we concluded that the heterozygous stop-gained variant rs121908568 in exon 8 of the AXIN2 gene could be responsible for tooth agenesis in the Iranian population.

Association of rs2013162 and rs2235375 Polymorphisms in IRF6 Gene with Susceptibility to Non-Syndromic Cleft Lip and Palate.

Background: Non-syndromic cleft lip occurs by the interaction of environmental and genetic factors. The purpose of the current study was to analyze the association of Single Nucleotide Polymorphisms (SNPs) in IRF6 and NSCL/P in an Iranian population. Methods: A group of 105 children with NSCL/P and 185 normal controls were included in the current study. Genotyping of IRF6 rs2013162 and rs2235375 was performed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. Results: A substantial association of AA and CA genotypes in rs2013162 with the risk of NSCL/P (AA vs. CC; OR=2.36; 95%CI [1.05-5.29], p=0.004; and CA vs. CC; OR=0.47; 95%CI [0.28-0.79], p=0.018) was found. However, there were no important associations between A allele and risk of NSCL/P (p=0.980). According to logistic regression analysis results, subjects with GG genotype and G allele in rs2235375 polymorphism had increased risk of NSCL/P. Conclusion: The IRF6 polymorphisms are associated with the susceptibility to NSCL/P in Iranian population.

Association between PTCH1 and RAD54B Single-Nucleotide Polymorphisms and Non-syndromic Orofacial Clefts in the Northeast Population of Iran.

Background: Non-Syndromic Cleft Lip with or without cleft Palate (NSCL/P) is a common developmental disorder of the head and neck with a multifactorial etiology. The current study aimed to evaluate the potential association of PTCH1 (rs10512248) and RAD54B (rs12681366) polymorphisms with NSCL/P in the Northeast Iranian population. Methods: In the present study, blood samples were taken from 122 subjects with NSCL/P and 161 healthy controls. Polymerase Chain Reaction (PCR) followed by Restriction Fragment Length Polymorphism (RFLP) were used to conduct genotyping of single-nucleotide polymorphisms. Results: Although differences were observed between cases and controls in rs10512248 and rs12681366, our data did not support a significant association of these polymorphisms with NSCL/P in our population. Conclusion: Our findings suggest that polymorphisms of rs10512248 and rs12681366 may not be potential risk factors for NSCL/P in the Northeast Iranian population due to the multifactorial and multiethnicity characteristics of some genes.

Peer Review Research Evaluation in Iran: Strengths, Weaknesses and Suggestions.

BACKGROUND: Peer based evaluation is a qualitative assessment done in different fields and levels. The aim of this study was to express the results of peer review evaluation in selected Iranian clinical research centers. METHODS: Four main domains consist of Leadership and governance, Structure, Knowledge products and Impact in thirty Iranian clinical research centers were evaluated based on peer review in 2019. Strengths and weak points with peer's suggestions were extracted based on qualitative analysis. RESULTS: Governance and impact domains have been more weak points than others. Equipment, facilities, physical space and human resource have been desirable in many research centers, and also there were some good developments in research publication. The most important suggestion was pay more attention to technology in planning, infra-structure and impact levels. CONCLUSION: Review missions of clinical research centers with more emphasis on health impact is necessary to clinical improvement.

The correlation between external apical root resorption and electric pulp test responses: a prospective clinical trial.

OBJECTIVE: The current study investigated the correlation between pulpal sensitivity to the electric pulp tester (EPT) and external apical root resorption (EARR) in four types of maxillary anterior teeth of fixed orthodontic treatment patients. METHODS: In this prospective cohort study, 232 anterior teeth of 58 patients (mean age 18.96 ± 6.13 years) treated with fixed orthodontic treatment were examined. The EPT readings were recorded at twelve time points immediately before archwire insertion. Root resorption of four maxillary incisors were measured by means of parallel periapical radiographs at three time intervals (six months interval from the start) through design-to-purpose software to optimize data collection. A multiple linear regression model and Pearson correlation coefficient were used to assess the association of EPT values and observed EARR (p< 0.05). RESULTS: The highest level of EPT measurement was recorded at initial visit, and then there was a decreasing trend in EPT level during treatment for the next six and twelve months. There was another increasing trend after six months till the finishing time of the treatment. There was a significant correlation between changes in root length and time of recording the root length (p< 0.001). There was significant positive correlation between changes in EPT level and amount of observed root resorption (p< 0.001). CONCLUSION: The relative decrease in electric pulp test level could be a diagnostic sign of root resorption during orthodontic treatment. Further studies with longer follow up are needed to confirm the current results.

Comparison of the effects of toothpastes containing nanohydroxyapatite and fluoride on white spot lesions in orthodontic patients: A randomized clinical trial.

BACKGROUND: Studies show that fluoride (F) and nano-hydroxyapatite (nano-HA) would result in remineralization of white spot lesions (WSLs), which are among the most prevalent consequences of fixed orthodontic treatment. The present study evaluates and compares the clinical effects of an Iranian toothpaste containing nano-HA with F-containing one on early enamel lesions. MATERIALS AND METHODS: In this randomized clinical trial study, 50 patients who had received fixed orthodontic treatment were recruited immediately after debonding. Three photographs, including frontal, lateral right and left views of occlusion, were obtained. Moreover, surfaces with WSLs were recorded using DIAGNOdent. Plaque index of each patient determined using disclosing agents. At first visit, each patient was asked to select one type of toothpaste (nano-HA containing vs. F containing named A or B), randomly and were instructed how to brush their teeth (25 patients in each group). Examination was done at 1, 3, and 6 months' intervals. Finally, photographs were analyzed by Digimizer (V5) software, and the lesion extent was recorded in pixels. SAS 9.4 was used to analyze data and was set at 0.05. RESULTS: According to data, lesion extent showed a significant decrease (P < 0.001). At baseline, the difference between the two groups regarding the lesion extent was 268 pixels while it dropped to 89 pixels after 6 months. DIAGNOdent results showed that at baseline, fluorescence difference was 0.3 while it reached the number of 0.8 after 6 months, indicating the outperformance of nano-HA containing toothpaste. CONCLUSION: The Iranian nano-HA containing toothpaste performed better than F-containing one in terms of the amount of remineralization and diminishing the lesion extent.

Screening PAX9, MSX1 and WNT10A Mutations in 4 Iranian Families with Non-Syndromic Tooth Agenesis.

BACKGROUND: Tooth agenesis is one of the most common developmental anomalies in human and the main reasons for its occurrence are still unknown. Mutations of several genes such as PAX9, MSX1, AXIN2, KDF1 and WNT10A have been reported which are associated with non-syndromic tooth agenesis. However, PAX9, MSX1 and WNT10A are commonly reported in the literature. Hence, the aim of this study was to investigate the mutations of these genes in 4 Iranian families with non-syndromic tooth agenesis. METHODS: DNA extractions from peripheral blood cells of patients with non-syndromic tooth agenesis from 4 unrelated Iranian families were performed by salting out method, and the candidate genes were amplified then followed by Sanger sequencing method. RESULTS: One missense variant (rs4904210) and 4 Single Nucleotide Polymorphisms (SNPs) (rs2236007, rs12883298, rs12882923 and rs12883049) were found in PAX9 gene. Five variants (rs149370601, rs8670, rs186861426 and rs774949973) including a missense variant (rs36059701) were detected in MSX1 gene and no variants were found in WNT10A gene. CONCLUSION: All variants were analyzed based on bioinformatics websites and Iranian gene databases, and as a result, it was revealed that variants of PAX9, MSX1 and WNT10A may not play a role in non-syndromic tooth agenesis among Iranian cases.

Effect of mesenchymal stem cells injection and low-level laser therapy on bone formation after rapid maxillary expansion: an animal study.

INTRODUCTION: One of the most common orthodontic problems is maxillary constriction, which is mostly treated by rapid palatal expansion (RPE). However, its high rate of relapse and prolonged retention period have led to some challenges for orthodontists. To encounter these issues, accelerating bone regeneration can provide long-term stability of expanded maxilla. The present study aimed to evaluate the effect of low-level laser therapy (LLLT), bone marrow-derived mesenchymal stem cells (BMSCs) and their combination on promoting bone regeneration of the inter-maxillary suture after RPE in rats. MATERIALS AND METHOD: Total of 60 rats went under RPE treatment. After 7 days, retention period started and interventions (group A, Control (saline); group B, LLLT; group C, BMSCs; group D, LLLT + BMSCs) were performed in the sutural area. After 21 days, radiographic and histological analyses were done. Histological analyses were conducted to evaluate the following criteria of the newly formed bone: the number of osteoblasts, new bone formation, vascularization, connective tissue. Moreover, sutural width was assessed in histologic images. To evaluate bone density at suture area, gray scale and Hounsfield Unit values were measured based on the occlusal radiographic and Micro-Computed topography images respectively. RESULTS: Only in group C and D, osteoblasts and new bone formation were observed in all of the samples. There were no significant differences among the study groups regarding the post-treatment sutural width (P > 0.05). In the radiographic analysis, only group D showed more bone density compared to the control group (P = 0.022). Similarly, in micro-CT analysis, the most bone density was observed in group D which was significantly more than the control group (P = 0.013). CONCLUSION: Our findings suggest that the application of LLLT and BMSCs is the most beneficial approach in accelerating bone regeneration in the inter-maxillary suture.

Knowledge production in Iranian cardiovascular research centers: A way to reduce the burden of disease.

BACKGROUND: According to the World Health Organization (WHO), non-communicable diseases (NCDs) including cardiovascular diseases (CVDs) will be responsible for almost 70% of all deaths in 2020. Therefore, knowledge production to find suitable ways to prevent, diagnosis, and effectively cover this disease in research centers is mandatory. Therefore, the present study is carried out with the aim to examine the results of studies performed in three years in Iranian cardiovascular centers. METHODS: Iranian cardiovascular research centers with more than three years of activity from 2015 to 2017 were evaluated. Research output, international collaboration, high quality publication, total citation, and average h-index (H) were evaluated and scored. RESULTS: 23 cardiovascular diseases research centers (CVDRCs) related to 15 universities of Medical Sciences (UMSs) were evaluated. The mean and standard deviation (SD) of age of the research activities in CVDRCs was 11.47 ± 8.60 years. Based on the research ranking, the first three centers were Isfahan Cardiovascular Research Center, Iran, Tehran Heart Center, and Shaheed Rajaei Cardiovascular Medical and Research Center, Iran, respectively, all of which have independent budget line. However, there is not any CVD research center in some provinces such as Zanjan, Kurdistan, Lorestan, and Arak, Iran. CONCLUSION: Mission oriented research activities in Iranian cardiovascular research centers may be effective in reducing the burden of CVDs. Moreover, establishment of CVD research centers in high risk areas may be useful.

Development of Evaluation System for Iranian Health Research Networks: Challenges and Lessons Learned.

BACKGROUND: Health research networks (HRNs) are critical components of large-scale systems of production and validation of scientific evidence. As evaluation of research systems is a reliable process to measure efficiency and effectiveness of their activities, we aimed to report the processes of development of evaluation indicators' for Iranian health research networks and the results of conducted assessment. METHODS: In 2017, for the first time, aim to develop the evaluation framework for national HRNs, following the qualitative approach to assess the quality of research we designed the peer review method as one of the most important tools. This qualitative method was conducted according to experts' views in specific fields. Key policy makers and stakeholders collaboratively developed a number of criteria for evaluation of research performance of Iranian HRNs. Following the review of conducted studies, benefitting from published guide line, these indicators were defined under 4 main axes of governance and leadership; infrastructures; research products and research impact. RESULTS: Based on requirements of developed protocol for evaluation of HRNs in Iran, 18 HRNs completed the processes of evaluation. Results show a progressive need for more attention to precise planning of HRNs for achieving to goals. Another point to consider is the attention to documenting processes. The observational system for researches for detection of latest research priority was the most important issues that need to be more addressed by all of networks. CONCLUSION: Research evaluation of Iranian HRNs more over creating of constructive positive competition provide an overview of the shortcomings and research challenges could be used for better planning and promotion of the health research system.

Mesiodistal angulation of posterior teeth in orthodontic patients with different facial growth patterns.

Background. Mesiodistal and buccolingual angulations of teeth are variable in different malocclusion classes. This study aimed to assess the mesiodistal angulation of posterior teeth in orthodontic patients with vertical, normal, and horizontal facial growth patterns. Methods. This descriptive, cross-sectional study evaluated 150 lateral cephalograms of orthodontic patients. According to cephalometric analysis, facial growth patterns were divided into three groups of normal, horizontal, and vertical (n=50). The angulation of maxillary and mandibular posterior teeth was then measured. Data were analyzed using SPSS 22. Results. The results showed an increase in the mean angle of maxillary and mandibular posterior teeth relative to palatal and mandibular planes in patients with a vertical facial growth pattern. Conversely, their angulation decreased relative to the bisected occlusal plane (BOP). The angulation of posterior teeth decreased relative to palatal and mandibular planes and increased relative to the occlusal plane with an increase in overbite. The mean angle of all maxillary teeth relative to the palatal plane was significantly greater in open bite patients compared to normal and deep bite patients. This value in patients with normal bite was significantly greater than that in deep bite patients (P<0.05). Conclusion. The current results revealed that in patients with a vertical growth pattern, all the posterior teeth had a forward inclination. Conversely, in patients with a horizontal growth pattern, the teeth had a backward inclination.

A Cochrane systematic review finds no reliable evidence for different management options for the fractured edentulous atrophic mandible.

Cochrane reviews provide high-quality, reliable, and up-to-date evidence concerning the effects of health care interventions. This review sought to provide reliable evidence regarding the effectiveness of any interventions (either open or closed) that could be used to manage a fracture of the edentulous mandible. A sensitive search strategy was developed and used across several databases (including the Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE) to identify randomized controlled trials and compare treatments for the management of fractured edentulous atrophic mandibles. Eligible studies were screened independently by two review authors and methodological quality was assessed based on criteria defined by the Cochrane Collaboration. Based on this review, there is inadequate evidence at present to confirm the effectiveness of a single approach for managing fractured atrophic edentulous mandibles; clinicians should continue basing treatment decisions on experience until high-level evidence is available.

Assessment of Environmental Health Research Centers in Iran due to knowledge production and utilization.

BACKGROUND: Knowledge production in environmental health promotion is one of the most important goals at the national level and establishing environmental health research centers (EHRCs) is one of the main strategies that will lead to achieving this goal. In this study, we are going to present the results of knowledge production and research performance evaluation of EHRCs in Iran. METHODS: In this cross sectional study, a specific check list has been used to assess Knowledge production and utilization through annual evaluations undertaken by research centers in Iran. This article has the results of the 4-year evaluation (2011-2014). RESULTS: The total number of EHRCs under the supervision of universities of medical sciences (UMS) is 34. The number of faculty members at these centers is 291 and the total approved projects by research council of UMS during 2011-2014, were 538. The number of published article increased from 282 in 2011 to 709 in 2014. During this period, the number of citations to EHRCs' articles was 4488 in Scopus database. The number of EHRCs' articles which have been referred in text books were 39. The proportion of published articles per academic member in environmental health has been 1.8 per year. CONCLUSION: Based on research performance evaluation, knowledge production and research is desirable in EHRCs, but research utilization to health environmental promotion is still inadequate and should be assessed by qualitative evaluation.