Comparison of cytotoxicity of three dentin bonding systems with two thicknesses of dentin barrier on L929 cell line

Introduction: Along with introduction of dentin bonding agents (DBA), their clinical use as lining materials is increasing rapidly. Since remaining dentinal thickness (RDT) has always been a concern for cytopathic effect of restorative materials, its effect on reduction of cytotoxicity of these materials especially DBAs is critical. The purpose of this study was to evaluate and compare the cytotoxicity of three dentin bonding systems, belonged to the 4th, 5th and 6th generation of DBAs on L929 cell line. Materials and Methods: Thirty human premolar teeth were included. Class I cavity preparations were prepared on occlusal surfaces. After crown separation, a flat dentinal surface was provided and RDT (remaining dentinal thickness) was adjusted at 0.5 and 1.5 mm. Then, cavities were treated in three groups with experimental DBAs: Group 1: Scotchbond multipurpose, Group 2: Excite, Group 3: AdheSE. Blue inlay wax sealed the cavities. Crowns were immersed in culture medium for 24 hours and the cytotoxicity of the resultant toxic medium was measured quantitatively with MTT assay in 4 serial dilutions. Data were analyzed with ANOVA and Tukey`s test at 95% significance level. Results: MTT assay determined that only in neat dilution of 0.5 mm RDT, cell changes were significantly different from control. Besides, no significant differences were found between the three experimental DBAs regarding cytotoxic effect on L929 cell line. Conclusion: Considering the limitations of an in vitro study, if the RDT is less than 0.5 mm in vivo, regardless of the type of DBA, destructive cellular changes in pulp tissue can be expected.   Keywords: Cytotoxicity, Dentin barrier, Dentin bonding agent.

Mesenchymal stem cell therapy in amyotrophic lateral sclerosis (ALS) patients: A comprehensive review of disease information and future perspectives

Amyotrophic lateral sclerosis (ALS) is a rare deadly progressive neurological disease that primarily affects the upper and lower motor neurons with an annual incidence rate of 0.6 to 3.8 per 100,000 people. Weakening and gradual atrophy of the voluntary muscles are the first signs of the disease onset affecting all aspects of patients’ lives, including eating, speaking, moving, and even breathing. Only 5-10% of patients have a familial type of the disease and show an autosomal dominant pattern, but the cause of the disease is unknown in the remaining 90% of patients (Sporadic ALS). However, in both types of disease, the patient’s survival is 2 to 5 years from the disease onset. Some clinical and molecular biomarkers, Magnetic Resonance Imaging (MRI), blood or urine test, muscle biopsy, and genetic testing are complementary methods for disease diagnosis. Unfortunately, with the exception of Riluzole, the only medically approved drug for the management of this disease, there is still no definitive cure for it. In this regard, the use of Mesenchymal Stem Cells (MSCs) for the treatment or management of the disease has been common in preclinical and clinical studies for many years. MSCs are multipotent cells having immunoregulatory, anti-inflammatory, and differentiation ability that makes them a good candidate for this purpose. This review article aims to discuss multiple aspects of ALS disease and focus on MSCs’ role in disease management based on performed clinical trials

Stem Cell Therapy: the ethical issues

The ability to culture human stem cells long term, and possibly indefinitely, and to control how such cells specialise to form the different tissues of the body offers the possibility of major advances in healthcare. Stem cells have been isolated and cultured, but a great deal of research is required to develop cell lines which can generate replacement cells and tissues to treat many diseases.Stem cells have arisen in policy debates and a lack of universal agreement on their use, safety and morality suggests these debates will become more widespread and impassioned. Issues that have arisen with the evolution of stem cells include patient safety, the exploitation of desperate patients, and distribution of resources. Developing science and growing hype warrant ethical scrutiny to ensure the nonmaleficence of patients and a balance between patient safety and scientific progress. A conservative approach combining domestic control with international regulation is recommended to simultaneously monitor and foster the promising, but perilous world of stem cells.   Keywords: Ethical, Stem Cell Therapy

Atopic dermatitis and the therapeutic methods: a literature review

Atopic dermatitis is an inflammatory skin disease that starts in the early life and usually persists by the end of life in 20% of cases. The disease shows multiple periods of relapse, and significantly affects the patient’s quality of life. The etiology of this disease is unknown, yet recent studies have reported incidence of immunological disorders and mutation in the filaggrin gene as the major causes. In some cases, concurrent incidence of infection with these inflammatory lesions reinforces the significance of treatment. Various methods of treatment such as emollients, corticosteroids, and calcineurin inhibitors are applied to manage this disorder. Traditional and complementary approaches may also help to control the disease. This disease is not usually easily controllable, thus requires full awareness of physicians on the underlying prospects of this disease. This review paper deals with the important aspects of the clinical perspectives and presents an integrative therapeutic approach for treating atopic dermatitis

Mesenchymal stem cell and osteoarthritis: a literature review

The most common disease in the aged population is osteoarthritis (OA) that is resulting in progressive dysfunction following isolated cartilage injuries, subchondral bone remodeling, tissue loss, marginal osteophytes, and loss of joint space. Mesenchymal stem cells (MSCs) are multipotent stem cells; they are able to produce many or all joint tissues. Bone marrow and adipose tissue are rich sources of mesenchymal cells that are useful for the reconstruction of injured tissues such as bone, cartilage, or cardiac muscle. Recently, some studies have been performed on the use of the direct intra-articular injection of mononuclear cells (MNCs) and MSCs as potential therapeutic targets in OA. In this review, the history of MSCs in the treatment of OA are explained. Injection of Bone Marrow Aspirates Concentrate (BMAC) has significantly improved both joint pain and function in radiologic findings; some studies suggested that the injection would be even more effective in early to moderate phases of OA. Injection of MSCs in combination with growth factors may be better solution for the treatment

Serum Interleukin 8 Level as a Diagnostic Marker in Late Neonatal Sepsis

Objective: Late-onset sepsis is responsible for high morbidity and mortality in newborn infants in the world and in particular in developing countries. In this study, we evaluated whether clinical characteristics, laboratory parameters and measurements of serum interleukin-8 (IL-8) are able to discriminate between late neonatal sepsis and normal baby. Methods: This was a prospective (case-control) study conducted between March 2007 and April 2008, at the neonatal intensive care unit, Ghaem Hospital, Mashhad, Iran. The study comprised 93 neonates ≥72 hours of life. The infants were categorized in two groups based on the clinical presentation, and biochemical markers including complete blood count, C-reactive protein (CRP) and blood culture: 1) Control group including 42 infants with routine screening and 2) Case group consisting of 38 infants with definitive infection (positive blood and/or cerebrospinal fluid culture) or clinical sepsis (clinical and laboratory signs of infection without positive blood or CSF culture). Receiver-operating characteristic curves were used for the determination of thresholds for the infection group versus healthy neonate group. Findings: Eighty infants were enrolled in this study. IL-8 and CRP decreased in order of definitive infection, clinical sepsis and healthy subjects respectively (P<0.001). Sensitivity, specificity, positive predictive value, negative predictive value for serum levels were 0.95, 0.1, 0.97, 0.1 for IL-8 and 0.83, 0.86, 0.83, 0.69 for CRP respectively (cut-off point for IL-8 >60pg/ml and for CRP>6mg/dl). Conclusion: IL-8 may be a valid and early predictive marker of neonatal infection. Also, IL-8 is associated with severity of infection

Osteoblastic cytokine response to gray and white mineral trioxide aggregate

INTRODUCTION: The materials used for root-end filling and perforation repair are in direct contact with live tissues e.g. bone and connective tissue; their effects however, are uncertain. The aim of this ex vivo study was to evaluate the osteoblastic secretory activity adjacent to gray and white mineral trioxide aggregate (MTA) and Intermediate Restorative Material (IRM). MATERIALS & METHODS: The studied materials were prepared and placed in 24-wells plate. Human MG-63 osteoblasts were introduced to materials after their initial set. The supernatant fluid was collected after 1, 3, and 7 days and the level of interleukin-1b was measured by ELISA test. A microscopic exam was also performed to assess proliferation and viability of the cells. Kruskal-Wallis and Tukey tests were used for analysis. RESULTS: There were significant higher levels of interleukin-1b in the gray and white MTA groups compared to IRM group (P0.05). Morphologic appearance of osteoblasts adjacent to gray and white MTA was similar to normal osteoblasts in all observation periods, however cells adjacent to IRM were round, signifying cytotoxicity of the adjacent material. CONCLUSION: Human osteoblasts’ biological response to white and gray MTA is more favorable compared to IRM

Are mesenchymal stem cells able to manage cytokine storm in COVID-19 patients? A review of recent studies

The Covid-19 disease has recently become one of the biggest challenges globally, and there is still no specific medication. Findings showed the immune system in severe Covid-19 patients loses regulatory control of pro-inflammatory cytokines, especially IL-6 production, called the “Cytokine storm” process. This process can cause injury to vital organs, including lungs, kidneys, liver, and ultimately death if not inhibited. While many treatments have been proposed to reduce cytokine storm, but the safety and effectiveness of each of them are still in doubt. Mesenchymal stem cells (MSCs) are multipotent cells with self-renewal potential capable of suppressing overactive immune responses and leading to tissue restoration and repair. These immuno-modulatory properties of MSCs and their derivatives (like exosomes) can improve the condition of Covid-19 patients with serious infectious symptoms caused by adaptive immune system dysfunction. Many clinical trials have been conducted in this field using various MSCs around the world. Some of these have been published and summarized in the present article, while many have not yet been completed. Based on these available data, MSCs can reduce inflammatory cytokines, increase oxygen saturation, regenerate lung tissue and improve clinical symptoms in Covid-19 patients. The review article aims to collect available clinical data in more detail and investigate the role of MSCs in reducing cytokine storms as well as improving clinical parameters of Covid-19 patients for use in future clinical studies