Myelinating glia differentiation is regulated by extracellular matrix elasticity

The mechanical properties of living tissues have a significant impact on cell differentiation, but remain unexplored in the context of myelin formation and repair. In the PNS, the extracellular matrix (ECM) incorporates a basal lamina significantly denser than the loosely organized CNS matrix. Inhibition of non-muscle myosin II (NMII) enhances central but impairs peripheral myelination and NMII has been implicated in cellular responses to changes in the elasticity of the ECM. To directly evaluate whether mechanotransduction plays a role in glial cell differentiation, we cultured Schwann cells (SC) and oligodendrocytes (OL) on matrices of variable elastic modulus, mimicking either their native environment or conditions found in injured tissue. We found that a rigid, lesion-like matrix inhibited branching and differentiation of OL in NMII-dependent manner. By contrast, SC developed normally in both soft and stiffer matrices. Although SC differentiation was not significantly affected by changes in matrix stiffness alone, we found that expression of Krox-20 was potentiated on rigid matrices at high laminin concentration. These findings are relevant to the design of biomaterials to promote healing and regeneration in both CNS and PNS, via transplantation of glial progenitors or the implantation of tissue scaffolds

Mir-135b induces osteosarcoma invasion by the modulation of foxo-1 and c-myc

Background: Osteosarcoma (OS) is the most common type of bone malignancy. Many studies have attempted to find the association between microRNAs and cancer-associated processes. Alterations in miRNA expression through genetic or epigenetic changes, impairment of transcription factors, and ectopic expression of miRNAs induce the development and progression of cancer. Al-though miR-135b has been thoroughly documented as an oncogene in the majority of studies, some controversies remain about the conflicting role of miR-135b as a tumor-suppressor. Objectives: The present study aimed at investigating the oncogenic and/or tumor-suppressing role of miR-135b in human OS. Methods: In this study, 21 OS tissue samples, along with 21 adjacent bone tissues (normal) as control specimens were collected to analyze the expression of miR-135b. The Saos2 cell-line was transiently transfected with the miR-135b mimic and inhibitor to assess its effect on two critical transcription factors, namely FOXO-1 and c-Myc. qRT-PCR was performed to quantify the expression of miR-135b in both OS tissues and the Saos2 cell-line. The MTT, cell migration, and cell invasion assays were used to characterize the miR-135b function. The western blot analysis was carried out to monitor the targets of miR-135b. Finally, the changes in cellular functions such as migration and invasion, following the transfection of miR-135b mimic and inhibitor, were verified. Results: The results showed that in comparison with the adjacent normal bone tissues, the expression of miR-135b was higher in OS tissue samples, which inversely correlated with the expression rate of FOXO-1, whereas the expression of c-Myc had a direct relationship to miR-135b expression. Functionally, the miR-135b mimic led to an increase in cell proliferation, invasion, and migration of OS cancer cells. Conclusions: MiR-135b induces the proliferation and invasion of OS cells by the degradation of FOXO-1 and upregulation of c-Myc. © 2020, Author(s)

Growth factors and new periodontology

Growth factors are biological mediators that have a key roll in proliferation, chemotaxy and"ndifferentiation by acting on specific receptors on the surface of cells and regulating events in wound"nhealing.They can be considered hormones that are not released in to the blood stream but have one a"nlocal action. Some of these factors can regulate premature change in GO to Gl phase in cell devesion"ncycle and even may stimulate synthesis of DNA in suitable cells, Growth substances, primarily secreted"nby fibroblasts, endothelia! cells, macrophages and platelet, include platelet derived growth factor"n(PDGF), insulin like growth factor (IGF) transforming growth factor (TGF)a and (3 and bone"nmorphogenetic proteins BMPs that approximately are the most important of them. (BMP)s could be"nused to control events during periodontal, craniofacial and implant wound healing through favoring bone"nformation"nAccording toLynch, combination of PGDF and IGF1 would be effective in promoting growth of all the"ncomponents of the periodontium."nThe aim of this study was to characterize growth factor and review the literature to determine the"nmechanism of their function, classification and application in implant and periodontal treatment

Evaluation of length of the root trunk in first and second molars in population of Tehran

The root trunk (RT) of molar teeth is important diagnostic parameter that has a key roll in"ndiagnosis and treatment planning."nThe purpose of this study is presenting a normal index of RT in mandibular molar teeth in different"nbuccal (B). distal (D), Lingual (Li) and mesial (M) entrances, and to compare them with each other."nIt is a case series study that 351 extracted molar teeth, after removal of soft tissue and debridement of"ncalculus, evaluated with gauge (with accuracy 0.1 mm)"nAccording to our measurement:"nIn maxilla: M-side: 3.88± 0.15 mm, B-side: 4.7± 1.7. D- side: 4.87± 0.13mm. So with P.value <0.05 M"nand D RT are longer than and M RT is shorter than D RT."nIn mandibule: B- side: 2.73± 0.11mm and L side: 4.03±- 0.13mm. So with P.value < 0.01 Li RT is longer"nthan B RT."nAccording to ochsenbine classification our studying teeth have medium to long RT. We prescribe for"neducating the crater therapy in periodontal surgery the emphasize must be focused on craters with"nmedium and long RT."nThe shortness of RT in B-side of lower molars needed the most attention during osteoctomy in resective"nprocedures. Because RT not depended to underlying factors such as age, social and economic situation,"nand for large amount of sample size in our study, the result could be extended in Tehran

Comparative evaluation of soft tissue characteristics around implant and tooth

"nBackground and Aim: Soft tissue condition around dental implant is an essential part for long term healthy and esthetic outcome. The aim of this study was to compare soft tissue dimensions between implant supported single  tooth replacement and the contra-lateral natural tooth. "nMaterials and Methods: This retrospective study was performed on dentate patients treated with anterior single  tooth implant at least 1 year ago. Of twenty eight, fourteen patients had been treated with one stasge method and others with two stage method. Biologic width (BW), papilla index (PI), and mucosal thickness (MT) were evaluated around implants and contra-lateral teeth clinically and compared with each other. The Wilcoxon test, Mann-Whitney test, and Student pair t-test were used to assess the differences between one stasge and two stage implants, and implant and tooth groups. "nResults: The mean BW around one stasge implants, two stage implants, and contra-lateral teeth were 1.42±0.48 mm, 1.67±0.48 mm, and 1.47±0.60 mm, respectively. The mean PI adjacent to one stasge implants, Two stage implants, and contra-lateral teeth were 2.50±0.52, 2.53±0.55, and 2.72±0.47, correspondingly. The mean MT around one stasge implants, two stage implants, and contra-lateral teeth were 3.10±0.48, 3.09±0.75, and 2.57±0.88, respectively. There was no statistically significant difference among one stasge implants, two stage implants, and contra-lateral teeth with regard to measured variables. "nConclusion: Based on the results of this investigation, in standard condition, it seems that there is no noticeable difference in indicators of; biologic width, papilla index, and mucosal thickness around one stasge implants, two stage implants, and contra-lateral teeth

The effects of aerobic and strength exercises on pulmonary function tests and quality of life in asthmatic patients

"nBackground: Asthma is a major health condition in Iran. This randomized clinical trial was aimed for the comparison of the effects of two exercise protocols (aerobic and aerobic-strength) on the pulmonary indices and quality of life of asthmatic patients."n "nMethods: The study was conducted in pulmonary ward of Dr Shariati Hospital in Tehran, and Research Center of Exercise Medicine of Tehran in 2009. Fifty six asthmatic patients were selected and after two weeks of education, their spirometric parameters were recorded and the St George's respiratory questionnaire was completed. Then patients were randomly assigned to two groups of A and B. For ten weeks group A did the aerobic-strength exercises and group B did only the aerobic ones at home. At the end, again their spirometric parameters were recorded and the questionnaire was completed. Finally 42 patients completed the study. "n "nResults: After the intervention, FEV1 and FVC but not FEV1/FVC increased in group A. There were no changes in these parameters in group B. In addition, post-intervention FEV1 and FVC were significantly higher in group A than group B. All scores of St George's respiratory questionnaire were significantly improved in both groups but they were not different between them."n "nConclusions: Our findings showed that regular aerobic exercises, individually or concomitant with strength exercises, could improve vital signs and quality of life of mild to moderate asthmatic patients. However, only aerobic exercises with strength ones improve spirometric parameters. Therefore, a combination of both aerobic and strength exercises could be considered in treatment protocols of asthmatic patients

The association between methacholine challenge test and respiratory symptoms: a study on 146 patients

"nBackground: Asthma is a life-threatening disease that can cause death due to bronchospasm. In addition to clinical symptoms such as wheezing, acute paroxysmal dyspnea, chronic cough after exposure to cold air or cough after exercise, spirometry is also necessary for the diagnosis of asthma. The association between respiratory symptoms and a positive methacholine challenge test (MCT) is still controversial. The aim of this study was to determine the association between methacholine test results and respiratory symptoms and allergy."n "nMethods: One hundred and forty-six patients with respiratory symptoms and normal baseline pulmonary function tests were enrolled in this cross-sectional study. The participants were divided into two groups according to their positive or negative response to MCT. The association between MCT and the clinical symptoms and allergy was later evaluated statistically."n "nResults: Out of 146 participants of the study 59 (40.4%) were female and 87 (59.6%) were male. The mean age of the participants was 33.8±13.8 years. Sixty-one patients (41.8%) had positive results for the test. There was an association between a history of allergy, wheezing and age with positive MCT results. The other clinical signs had no association with the test."n "nConclusion: Methacholine challenge test is the best diagnostic test for ruling out asthma in patients with normal pulmonary function tests in whom we cannot definitely rule out asthma based solely on clinical symptoms. Nevertheless, in adults with a history of allergy, wheezing and also in patients below 30, the probability for a positive MCT is high

Production of Mouse Monoclonal Antibody against Morphine without Cross Reactivity with Heroin

Introduction: Immunoassay procedures for detecting and determining opioids in blood and other biologic fluids are based on Monoclonal antibodies. In the present study, monoclonal antibody against Morphine was taken into account. Methods: Hybridoma protocol was used in order to produce the monoclonal antibody against morphine in mice. For this purpose, five 6–8-week old female BALB/c mice were immunized with morphine C6- hemisuccinated derivative conjugated to cationized bovine serum albumin (cBSA). The spleens lymphocytes were fused with SP2/0 cells using polyethylene glycol (PEG). Hybridoma clones were subcloned by limiting dilution. Class and subclass of monoclonal antibody were determined using Roche isostrip test. Moreover, antibody was purified by protein G affinity chromatography and affinity was determined according to the method described by Beatty et al. Finally, the cross reaction of monoclonal antibody was determined with some structurally related molecules such as codeine and apomorphine. Results: Among 3 hybridoma clones that reacted with the morphine-BSA, but not with BSA, after thrice limiting dilution, one stable hybridoma monoclon was obtained. The monoclonal antibody (MAb) was found to be of IgG2b class and subclass and containing lambda light chain. The affinity of the MAb to morphine was obtained 2.8 ×109 M-1 by non competitive enzyme immunoassay. The titer of supernatant of cell culture medium was 1/400. The MAb was cross reacted with codeine (100%) and apomorphine (16.5%), though no reaction was observed with heroin, naloxone, naltrexone, and papavrin. Conclusion: The study findings revealed that the produced antibody against morphine was comparable with other antibodies for specificity and affinity; therefore it is usable in design of diagnostic immunoassay in biologic fluids

Evaluation of periodontal condition of menopause women with osteoporosis and osteopenia and comparison with control group

Background and Aim: Several risk factors directly affect the development of periodontal diseases. Also some systemic diseases act indirectly as predisposing and aggrevating factors. Osteoporosis is one of these factors and one of its main causes is lack of physical activity in postmenopause period. The incidence of osteoporosis is increasing in our country. The goal of this study was to evaluate the periodontal condition of women with osteoporosis and osteopenia referred to bone densitometric division of Loghman hospital in 2003 and compare to control group. Materials and Methods: In this case control study based on BMD (Bone Mineral Density) measurement of back and thigh using DEXA method, 60 patients referred to bone densitometric division of Loghman hospital, were randomly selected. Cases were divided into three groups, 20 with osteoporosis, 20 with osteopenia and 20 normal cases. Periodontal indices consisting of plaque index (PI), tooth loss (TL), gingival recession (GR), probing pocket depth (PPD) and papilla bleeding index (PBI) were evaluated by clinical and radiographic examination. Data were analyzed by Kruskall Wallis and Dunn tests with p<0.05 as the limit of significance. Results: PBI, PI and TL were significantly higher in osteoporotic group than osteopenic and normal group. PPD was not different in the three groups. Due to the low prevalence of recession in our study, this parameter was not included in the statistical analysis. Conclusion: It seems that osteoporosis does not increase the incidence of periodontal diseases because it affects bone quality rather than quantity. In osteoporosis calcium deficiency and increasing age lead to decreased physical activity and ultimately affect the patient's oral hygiene performance. Thus, periodontal manifestations are presented as gingival bleeding and gingivitis