Repository of Research and Investigative Information Isfahan University of Medical Sciences
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Mechanical properties of mandibular and maxillary bone collagen fibrils based on nonlocal elasticity theory
No full textIn this paper, mechanical properties of collagen fibrils in the cortical bone and cortical-trabecular bone interface of the human mandible and maxilla have been investigated. Force-indentation curves on wet collagen fibrils are taken by applying the atomic force microscopy (AFM) nanoindentation technique and elastic modulus is measured. The distribution of stress and strain is determined by considering an elastic medium when it is deformed by a rigid cone. Afterwards, by applying the nonlocal elasticity theory and the indentation parameters, the nonlocal parameter of the collagen fibrils is calculated at the nano-scale. Finally, the elastic modulus and nonlocal modulus of the collagen fibrils are compared. According to the results, the highest and lowest values of the elastic modulus of the collagen fibrils are determined in the maxillary cortical-trabecular bone interface (4.16+/-0.18MPa) and mandibular cortical bone (2.03+/-0.14MPa), respectively. In general, in collagen fibrils, this parameter is higher in the maxillary bone than in the mandibular one. In the upper and lower jaws, the elastic modulus of collagen fibrils in cortical-trabecular bone interface is higher than that of the cortical bone. In mandibular and maxillary bone collagen fibrils, the range of nonlocal parameter and scaling parameter e(0) are computed as (0.430+/-0.013 -0.483+/-0.011nm) and (0.269+/-0.006-0.302+/-0.006), respectively. Also, the highest value of this parameters is recorded in the maxillary cortical-trabecular bone interface. The difference between the nanoscale modulus of collagen fibrils and the elastic modulus at large length scales is significant
Alterations in NFAT5 and ATP6V1E1 expression as potential diagnostic biomarkers in blood and brain for Alzheimer's disease: A study of gene overlap
No full textINTRODUCTION: Alzheimer's disease (AD), a prevalent cause of dementia, is characterized by amyloid plaques and tau tangles. It requires early diagnosis through the use of blood markers. This study examined changes in gene expression in blood and brain samples from patients with AD as potential diagnostic biomarkers. METHODS: The study utilized gene expression data from publicly available studies, including GSE4757, GSE5281, GSE28146, GSE48350, and GSE63060, to investigate expression changes in AD. Data integration and differential expression analysis were performed, and pathways related to candidate genes were identified using the Enrichr and BioPlents databases. Blood samples from 50 AD and controls were collected, followed by RNA extraction, cDNA synthesis, and qRT-PCR analysis using specific NFAT5 and ATP6V1E1 gene primers. RESULTS: We found 394 genes with increased expression and 759 with decreased expression in brain tissue. Upregulated genes were linked to TGF-B, BDNF, apoptosis, Hippo, P53, and IL-2 and IL-4 pathways. In contrast, downregulated genes were associated with pathways related to oxidative phosphorylation, PGC1-A, GABA, Alzheimer's, and calcium. Blood expression data showed 1147 probes with increased expression and 1413 with significant decreases. We found 31 genes that were upregulated and 87 genes that were downregulated, consistent across both blood and brain samples. Among the overlapping genes, RT-qPCR results indicated that the expression levels of NFAT5 and ATP6V1E1 may have diagnostic potential in the blood samples of Alzheimer's patients. CONCLUSION: The study identified changes in gene expression related to Alzheimer's in blood and brain samples. These changes affect pathways such as IL-2 and oxidative phosphorylation. Both in silico and ex vivo results revealed that the expression levels of NFAT5 and ATP6V1E1 in blood samples can serve as potential diagnostic biomarkers for Alzheimer's patients
A procedure for DNA methylation assessment in osteoporosis-related gene promoters of umbilical cord blood: A study on the Prospective Epidemiological Research Studies in Iran (PERSIAN) birth cohort
No full textINTRODUCTION: It is believed that DNA methylation can modify disease susceptibility in response to environmental factors as early as the perinatal period. In this study, we aimed to present a streamlined DNA methylation analysis procedure for osteoporosis-related gene promoters in the umbilical cord blood. METHODS: The Prospective Epidemiological Research Studies in Iran (PERSIAN) birth cohort was established in 2016. In this study, a total of 300 umbilical cord blood samples were collected at the time of delivery. For all samples, DNA was extracted and converted using sodium bisulfite. Multiple primer sets were designed for Wnt1, Wnt10b, beta-catenin, OPG, and RANKL gene promoters in the online MethPrimer platform. Next, bisulfite sequencing PCR (BSP), as the gold standard method for exploring methylated and unmethylated cytosines, was performed in a gradient-controlled setting. The PCR products were then purified and directly sequenced. Subsequently, the chromatograms were interpreted. RESULTS: For Wnt10b, beta-catenin, and OPG genes, the converted DNA could be successfully amplified. The frequency of acceptable chromatograms for analysis was 195 for Wnt10b (195/300, 0.65), 198 for beta-catenin (198/300, 0.66), and 50 for OPG (50/50, 100). CONCLUSION: BSP can be efficiently used to investigate the methylation of target gene promoters in umbilical cord blood DNA
Exploring the role of exosomes in diabetic neuropathy: From molecular mechanisms to therapeutic potential
No full textDiabetic neuropathy (DN) is a debilitating complication of diabetes mellitus (DM), characterized by progressive neuronal damage, sensory dysfunction, and impaired quality of life. Recent advances in exosome research have elucidated their crucial role in DN's pathogenesis, diagnosis, and treatment. Exosomes-nanoscale extracellular vesicles-function as vehicles for molecular cargo, including microRNAs (miRNAs), proteins, and lipids, which mediate intercellular communication and regulate key biological processes. Pathologically, hyperglycemia and hyperlipidemia induce the release of exosomes enriched with pathogenic miRNAs, such as miR-130a and miR-20b-3p, which disrupt neuronal function, axonal regeneration, and inflammatory pathways. Conversely, diagnostic studies highlight the utility of exosomal biomarkers like miR-7 and miR-221 in the early detection and monitoring of DN. Therapeutically, Schwann cell-derived and mesenchymal stromal cell (MSC)-derived exosomes demonstrate neuroprotective and reparative effects by enhancing mitochondrial function, modulating inflammation, and promoting axonal repair. Emerging approaches, including engineered exosomes and miRNA-enriched vesicles, further expand their therapeutic potential. Despite these advances, challenges such as standardization, large-scale production, and clinical validation remain in translating these findings into clinical practice. This review underscores the multifaceted roles of exosomes in DN and highlights their potential as innovative tools for precision diagnostics and targeted therapies, paving the way for future research and clinical applications
The effect of bleaching agent on the compressive strength of orthodontic thermoplastic retainer materials
No full textBACKGROUND: There is an increasing desire for teeth bleching after orthodontic treatment. Therefor, this study aims to evaluate the effect of carbamide peroxide 15 and thermocycling on the compressive strength of polyethylene terephthalate glycol (PETG) thermoplastic retainer material. MATERIALS AND METHODS: In this in vitro study, forty samples of PETG material were thermoformed over a plastic template (10 mm x 8 mm x 2 mm). The samples were divided into four groups, with ten samples in each group. Group I served as the control, Group II was exposed to carbamide peroxide 15 (5 h daily for 14 days), Group III underwent thermocycling (5000 times), and Group IV underwent thermocycling (5000 times) followed by exposure to carbamide peroxide 15 (5 h daily for 14 days). The compressive strength of the groups was then evaluated using one-way ANOVA and Tukey's HSD tests for statistical analysis. The significance level was set to 0.05. RESULTS: The analysis showed a significant difference among the four groups. The compressive strength of all groups significantly decreased compared to the control group. Group II exhibited a significant decrease compared to Group III (P = 0.003). However, there was no significant difference between Group II and Group IV (P = 0.191). In addition, there was no significant difference observed between Group III and Group IV (P = 0.308). Group II had the lowest compressive strength (163.9 Mpa). CONCLUSION: It is not recommended to use a thermoplastic retainer as a bleaching tray during the initial phase of retention. However, since there were no further harmful effects of bleaching agents observed after thermocycling, it is possible to recommend the use of a thermoplastic retainer as a bleaching tray toward the end of the retention phase
SCALPEL: A Structured Handoff Protocol for Scrub Nurses in the Operating Room for Patient Safety
No full textPublisher Correction: Predicting high sensitivity C-reactive protein levels and their associations in a large population using decision tree and linear regression
No full textPrevalence of food allergy and its association with atopic dermatitis in Iran: Results from the PERSIAN birth cohort
No full textBACKGROUND: The incidence of food allergy (FA) has been increasing worldwide, causing growing concern on a global scale. OBJECTIVE: This birth cohort study analyzes the incidence of reported FA and other atopic comorbidities in children from birth to age 2 years who were living in 4 urban and semiurban areas in Iran. METHODS: Children were followed from birth until age 24 months, with follow-up questionnaires administered through parent or guardian interviews conducted when the children were aged 2, 4, 6, 12, and 24 months. RESULTS: The rate of physician-diagnosed FA reported by parents or guardians was higher than expected, with a cumulative incidence of 7.7 in children younger than 24 months. The highest prevalence of FA was found in Yazd, the most urban of the 4 cities studied. Breast-feeding was associated with a decreased cumulative risk of FA at age 12 months, with only 5 of breast-fed children developing parent-reported pediatrician-diagnosed FA compared with 13 of infants who never received breast milk after birth. CONCLUSION: This study provides valuable insight into the incidence of FA in the Middle East, which has previously not been reported on, and it is crucial in our understanding of global FA prevalence. The study demonstrates a high incidence of FA in an area with historically lower rates and confirms that breast-feeding does prevent FA during infancy in this population
Ataxia With Vitamin E Deficiency: Case Series, Vitamin E Therapy Response, Founder Effect, and In Silico Analysis
No full textAtaxia with Vitamin E Deficiency (AVED) is a rare autosomal recessive genetic disorder, that caused by pathogenic variants in the TTPA gene, which encodes the alpha-tocopherol transfer protein. This study investigates eight patients from three consanguineous Iranian families, using exome sequencing (ES) and Sanger sequencing to identify novel pathogenic variants in the TTPA gene. Two variants were identified: c.219T>A (p.Tyr73*) and c.205-1G>C. the first one (c.219T>A) related to potentially founder effects within regions of homozygosity. Clinical outcomes varied among patients based on vitamin E therapy initiation, with early treatment preventing severe neurological impairment. These findings improve knowledge of TTPA variants, supporting targeted genetic-based therapy. This study emphasizes the importance of genetic screening in consanguineous communities for the early detection and management of Mendelian diseases, with additional implications for managing rare genetic disorders generally
Chemotaxis effects on the vascular tumor growth: Phase-field model and simulations
No full textIn this paper, we propose a vascular tumor growth model that combines a phase-field tumor model with a phase-field angiogenesis model. By incorporating various tumor cell species, we capture the instabilities of the tumor in the presence of evolving neovasculature. The model not only considers different dynamics of tumor cell phase conversions, movement, and pressure effects but also provides a comprehensive representation of angiogenesis, encompassing chemotaxis of endothelial cells, sprouting, anastomoses, and blood flow in capillaries. This study evaluates the impact of chemotaxis on tumor cell movement in both avascular and vascular tumor growth scenarios. The results highlight the acceleration of tumor growth when angiogenesis is stimulated. Additionally, the investigation explores various initial distances of the tumor from neighboring vessels, revealing a critical threshold distance beyond which the angiogenesis factor fails to stimulate angiogenesis, resulting in the tumor maintaining a stable state. The integration of chemotaxis into the growth model induces instabilities, leading to increased nutrient availability and faster growth for the tumor. Furthermore, the study considers anti-angiogenesis therapy as an ideal approach, assuming complete inhibition of angiogenesis from the early stages. In this scenario, the tumor persists in a steady state, adhering to the avascular size limit in the absence of neovasculature. Conversely, when considering chemotaxis, anti-angiogenesis therapy loses efficiency, enabling unrestrained tumor growth towards neighboring vessels. This work sheds light on the intricate interplay among chemotaxis, angiogenesis, and anti-angiogenesis therapy in the context of vascular tumor growth, providing valuable insights for the development of targeted treatment strategies