Showing papers by "Tehran University of Medical Sciences published in 2022"

Autoimmune complications of COVID-19.

Abstract: Coronavirus disease 2019 (COVID-19) is still propagating a year after the start of the pandemic. Besides the complications patients face during the COVID-19 disease period, there is an accumulating body of evidence concerning the late-onset complications of COVID-19, of which autoimmune manifestations have attracted remarkable attention from the first months of the pandemic. Autoimmune hemolytic anemia, immune thrombocytopenic purpura, autoimmune thyroid diseases, Kawasaki disease, Guillain-Barre syndrome, and the detection of autoantibodies are the cues to the discovery of the potential of COVID-19 in inducing autoimmunity. Clarification of the pathophysiology of COVID-19 injuries to the host, whether it is direct viral injury or autoimmunity, could help to develop appropriate treatment.

The role of type I interferon in the treatment of COVID-19.

Abstract: Although significant research has been done to find effective drugs against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), no definite effective drug exists. Thus, research has now shifted towards immunomodulatory agents other than antivirals. In this review, we aim to describe the latest findings on the role of type I interferon (IFN)-mediated innate antiviral response against SARS-CoV-2 and discuss the use of IFNs as a medication for COVID-19. A growing body of evidence has indicated a promoting active but delayed IFNs response to SARS-CoV-2 and Middle East respiratory syndrome coronavirus in infected bronchial epithelial cells. Studies have demonstrated that IFNs' administration before the viral peak and the inflammatory phase of disease could offer a highly protective effect. However, IFNs' treatment during the inflammatory and severe stages of the disease causes immunopathology and long-lasting harm for patients. Therefore, it is critical to note the best time window for IFNs' administration. Further investigation of the clinical effectiveness of interferon for patients with mild to severe COVID-19 and its optimal timing and route of administration can be beneficial in finding a safe and effective antiviral therapy for the COVID-19 disease.

Omicron (B.1.1.529) variant: Development, dissemination, and dominance

Abstract: Since late November, a new wave of uncertainty and panic has spread across the world, as the number of coronavirus disease 2019 (COVID-19) cases raised dramatically, especially in the southern part of Africa. A new SARS-CoV-2 variant, B.1.1.529, was designated by the World Health Organization as a variant of concern and named Omicron.1 Since then, many questions have been raised to understand how severe, immune escape, and infectious it can be. Besides this, the question of how and where it might have emerged, How far it might have already been spread, and can Omicron dominate the previous variants of concern, remains to be answered. It is not clear whether Omicron has evolved in South Africa or not. However, Gao et al. suggested it might have evolved in a large immunocompromised population with a lower vaccination rate, where public health infrastructures are relatively weaker than other nations.2 African nations have the highest rate of HIV infection, while the vaccination rates are relatively lower than other countries.3 As the immune system of HIV patients cannot correctly detect or vanish the pathogens, it will give the coronavirus a valuable opportunity to endure, multiply, and possibly, mutate as the course of the disease continues.4 In another theory, SARS-CoV-2 might have been hidden in an animal reservoir, possibly rodents, evolved for a while, and returned to the human population with a relatively new genomic sequence, now known as Omicron.5 Whether it emerged in a human population or developed in other species, it is still too early to exclude any theory about the origin of the Omicron or to identify where it actually evolved. During the past 2 years, COVID-19 has shown surprisingly rapid dissemination across the globe, and now, as of December 27, 89 countries are officially reported Omicron from their genome sequences.6 As the highest mutated SARS-CoV-2 variant, Omicron may potentially spread faster, have higher infectivity, and escape more from immunity than previous variants of concern.7 Besides this, sequencing technology is not as convenient as other testing methods to provide communities with fast and valid data collecting about the variant. Considering the challenging process of vaccine manufacturing and delivery time, Omicron may be passed every border before the next suitable vaccine is ready. This could trigger an alarm for national authorities and populations to advocate and follow protective recommendations even more than before.8 When the original SARS-CoV-2 has emerged in Wuhan, China, no one would expect a global pandemic will happen. The pattern of infection, transmissibility, and immune evasion was so impulsive that soon after the detection, the new coronavirus scattered all across the world. After almost 1 year, Alpha, a new variant of concern, has emerged in the United Kingdom and raised a new wave of reported cases and hospital admissions with COVID-19 globally. Up to early 2021, Alpha cases were slightly replaced with Beta and Gamma, which have been first detected in South Africa and Brazil, respectively.9 Delta, the current dominant SARS-CoV-2 variant, was first documented from India in October 2020, and not so far, disseminated all over the world. With a reproductive number (R0) of 5.08, Delta is far more transmissible and immune escape than the original coronavirus.10 Now with Omicron, there is a concern about another wave of infection and hospitalization as it spreads much faster than previous variants of concern. A recent study suggests Omicron may probably be more transmissible and cause more infection than Delta and Delta-plus variants since large mutations modulate the affinity of the Spike protein to the ACE-2 receptor.11 Preliminary data also indicated more vaccine evasion and a higher rate of reinfection with Omicron compared to previous variants of concern.12 Through relatively new mutations, Omicron may have been evolved to a more transmissible and immune escape variant. Given the rapidly increasing number of COVID-19 cases and the rise in hospitalizations, healthcare systems may become quickly overwhelmed as we approach 2022. By now, we have to wait for further results to see how effective current preventive and therapeutic methods are against the Omicron. If the symptoms of the new cases continue to be mild, Omicron may provide us with global herd immunity, and hopefully, end the pandemic. Conversely, if the pathogenesis of the Omicron is as extensive as its capability to spread or escape from immunity, this can be the most challenging coronavirus to deal with, and the world will face a drastic wave of the COVID-19 again. The authors declare that there are no conflict of interests. Shayan Rahmani conceptualized the title, collected data, and prepared the first draft of the manuscript. Nima Rezaei critically revised the manuscript, edited and finalized the draft, and supervised the study. All of the authors have read and approved the final draft of the manuscript. Not applicable. Not applicable.

COVID-19: General Strategies for Herbal Therapies

Abstract: The coronavirus disease-2019 (COVID-19) pandemic started in early 2020 with the outbreak of a highly pathogenic human coronavirus. The world is facing a challenge and there is a pressing need for efficient drugs. Plants and natural compounds are a proven rich resource for new drug discovery. Considering the potential of natural products to manage the pandemic, this article was designed to provide an inclusive map of the stages and pathogenetic mechanisms for effective natural products on COVID-19. New drug discovery for the COVID-19 pandemic can encompass both prevention and disease management strategies. Preventive mechanisms that may be considered include boosting the immune response and hand hygiene in the preexposure phase; and blocking of virus binding and entry in the postexposure phase. Potential therapeutic target mechanisms include virus-directed therapies and host-directed therapies. Several medicinal plants and natural products, such as Withania somnifera (L.) Dunal and propolis for prevention; Tanacetum parthenium (L.) for treatment; and Ammoides verticillata (Desf.) Briq and Nigella sativa L. for both prevention and treatment have been found effective and are good targets for future research. The examples of phytochemical compounds that may be effective include aloin and terpenes as anti-septics; isothymol, dithymoquinone, and glycyrrhizin as inhibitors of virus binding and entry; glycyrrhizin, and berberine as replication suppressants; ginsenoside Rg1 and parthenolide as immunomodulators; and eriocitrin, rhoifolin, hesperidin, naringin, rutin, and veronicastroside as anti-complements. Recognizing different mechanisms of fighting against this virus can lead to a more systematic approach in finding natural products and medicinal plants for COVID-19 prevention and treatment.

Accumulation and human health risk assessment of nitrate in vegetables irrigated with different irrigation water sources- transfer evaluation of nitrate from soil to vegetables

Abstract: The present study aimed to investigate the rate of accumulation, human health risk assessment, and nitrate-related transfer factor in vegetables irrigated with different sources, including treated wastewater effluent (TWE) of Kermanshah wastewater treatment plant, Gharasoo river water (RW) of Kermanshah, and well water with chemical fertilizer (WWF). For this purpose, three different types of vegetables, including basil, coriander, and radish, was cultivated, and each of them was irrigated by the three irrigation sources mentioned above. Finally, the amount of nitrate in different sources of irrigation, soil (before growing vegetables and after harvesting vegetables), and the mentioned vegetables was measured. Based on the study results, it can be concluded that the water of the Gharasoo River (RW), compared to the other two irrigation sources, causes more nitrate accumulation in the soil and vegetables grown in it. The highest transmission factor was related to basil vegetables irrigated with WWF. The results showed that the average daily intake of nitrate through the consumption of vegetables grown in Kermanshah with any irrigation water is less than the allowable amount, so the consumption of such vegetables is not dangerous to consumers' health. Therefore, it is suggested that the best irrigation source for vegetable cultivation in Kermanshah is TWE, provided that all of its physical, chemical and microbial parameters meet the standards for reuse in agriculture irrigation. Thus, the use of treated wastewater reduces the need for farmers to use chemical and organic fertilizers and cost-effectiveness, high frequency, and high availability.

Riboflavin is an antioxidant: a review update

Abstract: Aerobic organisms need antioxidant defense systems to deal with free radicals which either are produced during aerobic respiration or may have an external origin. Oxidative stress, which is resulted from an imbalance between the production of free radicals and the ability of antioxidant defense mechanism to deactivate them, is involved in the development of many chronic diseases such as cancer, diabetes, CVD and some neurodegenerative diseases. Reinforcing the antioxidant potential of the body has been considered as a strategy that could prevent and manage such conditions. In the previous review article published by British Journal of Nutrition, in 2014, for the first time, we concluded that riboflavin could alleviate oxidative stress. Although riboflavin can serve as a prooxidant when exposed to ultraviolet irradiation, the literature is replete with studies that support its antioxidant properties. Furthermore, recent evidence suggests that riboflavin may have a therapeutic potential in many conditions in which oxidative stress is involved, although the therapeutic efficacy of riboflavin as an antioxidant requires further study under conditions of wellness and clinical disease.

Exercise-induced increase in blood-based brain-derived neurotrophic factor (BDNF) in people with multiple sclerosis: A systematic review and meta-analysis of exercise intervention trials

Abstract: Exercise training may affect the blood levels of brain-derived neurotrophic factor (BDNF), but meta-analyses have not yet been performed comparing pre- and post-intervention BDNF concentrations in patients with multiple sclerosis (PwMS).To perform a meta-analysis to study the influence of exercise on BDNF levels and define components that modulate them across clinical trials of exercise training in adults living with multiple sclerosis (MS).Five databases (PubMed, EMBASE, Cochrane Library, PEDro database, CINAHL) were searched up to June 2021. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we included 13 articles in the meta-analysis, including 271 subjects. To investigate sources of heterogeneity, subgroup analysis, meta-regression, and sensitivity analysis were conducted. We performed the meta-analysis to compare pre- and post-exercise peripheral levels of BDNF in PwMS.Post-exercise concentrations of serum BDNF were significantly higher than pre-intervention levels (Standardized Mean Difference (SMD): 0.33, 95% CI: [0.04; 0.61], p-value = 0.02). Meta-regression indicated that the quality of the included studies based on the PEDro assessment tool might be a source of heterogeneity, while no significant effect was found for chronological age and disease severity according to the expanded disability status scale.This systematic review and meta-analysis shows that physical activity increases peripheral levels of BDNF in PwMS. More research on the effect of different modes of exercise on BDNF levels in PwMS is warranted.

Tissue engineering in dermatology - from lab to market

Abstract: Tissue Engineering is a branch of regenerative medical technology which helps replace damaged tissue using appropriate scaffolding, living cells, and growth factors. Using tissue engineering products can be a promising method for treating skin lesions such as wounds and deep burns. The interaction and interconnection of cells within the bio-culture medium or within a three-dimensional scaffold provides the conditions for tissue regeneration and subsequent healing of skin wounds. Tissue engineering in the field of dermatology has evolved over time from a single application of skin cells or biopolymer scaffolds to the use of cell and scaffold combinations for the treatment, repair, and closure of acute and chronic skin wounds. It has evolved. This technology has reached a point where most products are accepted, and the body rejects a small number, which strengthens the tissue engineering market. In this article, we aimed to review and study the market of this field by reviewing various articles on tissue engineering in the field of dermatology. Tissue-engineered skin substitutes are future options for wound healing and tissue regeneration strategies.

Segmentation of pancreatic ductal adenocarcinoma (PDAC) and surrounding vessels in CT images using deep convolutional neural networks and texture descriptors

Abstract: Fully automated and volumetric segmentation of critical tumors may play a crucial role in diagnosis and surgical planning. One of the most challenging tumor segmentation tasks is localization of pancreatic ductal adenocarcinoma (PDAC). Exclusive application of conventional methods does not appear promising. Deep learning approaches has achieved great success in the computer aided diagnosis, especially in biomedical image segmentation. This paper introduces a framework based on convolutional neural network (CNN) for segmentation of PDAC mass and surrounding vessels in CT images by incorporating powerful classic features, as well. First, a 3D-CNN architecture is used to localize the pancreas region from the whole CT volume using 3D Local Binary Pattern (LBP) map of the original image. Segmentation of PDAC mass is subsequently performed using 2D attention U-Net and Texture Attention U-Net (TAU-Net). TAU-Net is introduced by fusion of dense Scale-Invariant Feature Transform (SIFT) and LBP descriptors into the attention U-Net. An ensemble model is then used to cumulate the advantages of both networks using a 3D-CNN. In addition, to reduce the effects of imbalanced data, a multi-objective loss function is proposed as a weighted combination of three classic losses including Generalized Dice Loss (GDL), Weighted Pixel-Wise Cross Entropy loss (WPCE) and boundary loss. Due to insufficient sample size for vessel segmentation, we used the above-mentioned pre-trained networks and fine-tuned them. Experimental results show that the proposed method improves the Dice score for PDAC mass segmentation in portal-venous phase by 7.52% compared to state-of-the-art methods in term of DSC. Besides, three dimensional visualization of the tumor and surrounding vessels can facilitate the evaluation of PDAC treatment response.

Modification of sodium alginate by octenyl succinic anhydride to fabricate beads for encapsulating jujube extract

Abstract: The effect of modification of sodium alginate on the beads properties was investigated and compared with unmodified alginate beads. The effect of storage conditions on the shelf life of the beads was determined. The modification of sodium alginate was achieved with octenyl succinic anhydride (OSA). Antioxidant activity and total phenolic compounds of the jujube extract was evaluated. Some physical and structural properties yield and encapsulation efficiency of the beads were measured. The encapsulation yield of the beads was significantly affected by modification of sodium alginate. The highest yield was observed in the alginate stored at ambient temperature on the day 14th which was 35.21%. The average beads size of alginate was 5.10 and 4.68 mm in modified and unmodified alginate beads, respectively. Modification also had a significant effect on the hardness of the beads. Higher Tg which ensures good product stability in thermal process was clearly seen in the modified beads maintained at ambient temperature. Fourier Transform Infrared Spectroscopy (FT-IR) revealed the existence of OH groups in the extract-loaded beads. These findings have important implications on designing preservation and delivery systems of soluble bioactive compounds of jujube extract to apply in development of new functional foods and drinks.

Health Care Policies and COVID-19 Prevalence: Is There Any Association?

Abstract: The coronavirus disease 2019 (COVID-19) pandemic has affected almost all countries and territories. As of December 6, 2020, the United States of America and India have the highest prevalence. Each country has implemented different strategies to control and reduce the spread of disease. Here, the association between prevalence number and health policies is evaluated by comparing 2 groups of countries: (1) Italy, the United States of America, Germany, Spain, and India with a higher prevalence than a linear trend line; and (2) Singapore and China with a lower or equal prevalence than linear forecasts. A rapid overview revealed that many countries have similar strategies for controlling COVID-19, including the suspension of air travel, the lockdown on the cities with the most cases detected, active case findings, monitoring of close contacts, and raising public awareness. Also, they used a gradual and phased plan to reopen activities. So, the difference between countries in the burden of COVID-19 can be attributable to the strict mode and nonstrict mode of implementation of strategies. Limitations at the national levels call for systemic rather than regional strategies.