Extremely Low-Frequency Magnetic Field Enhances the Therapeutic Efficacy of Low-Dose Cisplatin in the Treatment of Ehrlich Carcinoma

e present study examines the therapeutic efficacy of the administration of low-dose cisplatin (cis) followed by exposure to extremely low-frequency magnetic �eld (ELF-MF), with an average intensity of 10 mT, on Ehrlich carcinoma in vivo. e cytotoxic and genotoxic actions of this combination were studied using comet assay, mitotic index (MI), and the induction of micronucleus (MN). Moreover, the inhibition of tumor growth was also measured. Treatment with cisplatin and ELF-MF (group A) increased the number of damaged cells by 54% compared with 41% for mice treated with cisplatin alone (group B), 20% for mice treated by exposure to ELF-MF (group C), and 9% for the control group (group D). Also the mitotic index decreased signi�cantly for all treated groups ( ). e decrement percent for the treated groups (A, B, and C) were 70%,65%, and 22%, respectively, compared with the control group (D). Additionally, the rate of tumor growth at day 12 was suppressed signi�cantly ( ) for groups A, B, and C with respect to group (D). ese results suggest that ELF-MF enhanced the cytotoxic activity of cisplatin and potentiate the bene�t of using a combination of low-dose cisplatin and ELF-MF in the treatment of Ehrlich carcinoma

Assessment of Genotoxic and Cytotoxic Hazards in Brain and Bone Marrow Cells of Newborn Rats Exposed to Extremely Low-Frequency Magnetic Field

The present study aimed to evaluate the association between whole body exposure to extremely low frequency magnetic field (ELF-MF) and genotoxic , cytotoxic hazards in brain and bone marrow cells of newborn rats. Newborn rats (10 days after delivery) were exposed continuously to 50 Hz, 0.5 mT for 30 days. The control group was treated as the exposed one with the sole difference that the rats were not exposed to magnetic field. Comet assay was used to quantify the level of DNA damage in isolated brain cells. Also bone marrow cells were flushed out to assess micronucleus induction and mitotic index. Spectrophotometric methods were used to measure the level of malondialdehyde (MDA) and the activity of glutathione (GSH) and superoxide dismutase (SOD). The results showed a significant increase in the mean tail moment indicating DNA damage in exposed group (P<0.01,0.001,0.0001). Moreover ELF-MF exposure induced a significant (P<0.01,0.001) four folds increase in the induction of micronucleus and about three folds increase in mitotic index (P<0.0001). Additionally newborn rats exposed to ELF-MF showed significant higher levels of MDA and SOD (P<0.05). Meanwhile ELF-MF failed to alter the activity of GSH. In conclusion, the present study suggests an association between DNA damage and ELF-MF exposure in newborn rats

3-D Volumetric Evaluation of Human Mandibular Growth

Bone growth is a complex process that is controlled by a multitude of mechanisms that are not fully understood.Most of the current methods employed to measure the growth of bones focus on either studying cadaveric bones from different individuals of different ages, or successive two-dimensional (2D) radiographs. Both techniques have their known limitations. The purpose of this study was to explore a technique for quantifying the three dimensional (3D) growth of an adolescent human mandible over the period of one year utilizing cone beam computed tomography (CBCT) scans taken for regular orthodontic records. Three -dimensional virtual models were created from the CBCT data using mainstream medical imaging software. A comparison between computer-generated surface meshes of successive 3-D virtual models illustrates the magnitude of relative mandible growth. The results of this work are in agreement with previously reported data from human cadaveric studies and implantable marker studies. The presented method provides a new relatively simple basis (utilizing commercially available software) to visualize and evaluate individualized 3D (mandibular) growth in vivo

The effect of low level laser on condylar growth during mandibular advancement in rabbits

<p>Abstract</p> <p>Introduction</p> <p>It has been shown that Low Level Laser (LLL) has a positive effect on bone formation. The aim of this study was to evaluate the effect of low level laser on condylar growth during mandibular advancement in rabbits.</p> <p>Materials and methods</p> <p>Continuous forward mandibular advancement was performed in fourteen male Albino rabbits with the mean age of 8 weeks and the mean weight of 1.5 ± 0.5 kg, with acrylic inclined planes. The rabbits were randomly assigned into two groups after 4 weeks. LLL (KLO3: wave length 630 nm) was irradiated at 3 points around the TMJ, through the skin in the first group. The exposure was performed for 3 minutes at each point (a total of 9 minutes) once a day for 3 weeks. The control group was not exposed to any irradiation. The rabbits in both groups were sacrificed after two months and the histological evaluation of TMJ was performed to compare fibrous tissue, cartilage, and new bone formation in condylar region in both groups. Disc displacement was also detected in both groups. Student's t-test, Exact Fisher and Chi square tests were used for the statistical analysis.</p> <p>Results</p> <p>The formation of fibrous tissue was significantly lower, while bone formation was significantly greater in lased group as compared with control group. The thickness of cartilage did not differ significantly between two groups.</p> <p>Conclusion</p> <p>Irradiation of LLL (KLO3) during mandibular advancement in rabbits, increases bone formation in condylar region, while neither increase in the cartilage thickness nor fibrous tissues was observed.</p

Modelling semantic transparency

We present models of semantic transparency in which the perceived trans- parency of English noun–noun compounds, and of their constituent words, is pre- dicted on the basis of the expectedness of their semantic structure. We show that such compounds are perceived as more transparent when the first noun is more frequent, hence more expected, in the language generally; when the compound semantic rela- tion is more frequent, hence more expected, in association with the first noun; and when the second noun is more productive, hence more expected, as the second ele- ment of a noun–noun compound. Taken together, our models of compound and con- stituent transparency lead us to two conclusions. Firstly, although compound trans- parency is a function of the transparencies of the constituents, the two constituents differ in the nature of their contribution. Secondly, since all the significant predictors in our models of compound transparency are also known predictors of processing speed, perceived transparency may itself be a reflex of ease of processing

Effect of Bilateral Mandibular Osteodistration on the Condylar Cartilage: An Experimental Study on Rabbits

Although various aspects of bone formation during distraction osteogenesis have been studied extensively, there are only limited experimental data concerning the influence of hyper-physiologic mandibular distraction rate on structural alterations in the temporomandibular joint (TMJ) condylar cartilage. The purpose of this study was to evaluate the effect of bilateral distraction osteogenesis of the mandibular body, at a hyper-physiologic rate and length, on the integrity of the condylar cartilage in rabbits. MATERIALS AND METHODS: Eighteen healthy adult male rabbits weighing 2 to 3 kg were assigned to 1 of 2 groups: the control group (n = 2 rabbits, 4 joints) or the study group (n = 16 rabbits, 32 joints) four rabbits (8 joints) in each subgroup according to the post-distraction period (1,2,3 or 4 weeks). In the control group, rabbits received sham surgery (Osteotomy without distraction) and then left to live for 4 weeks under the same condition of the study group then euthanized using intravenous overdose of pentobarbital sodium. In the study group, an extra oral custom-made distracter was employed to achieve bilateral mandibular hyper physiologic distraction (1.5 mm twice daily for 5 days) distraction. All animals were evaluated clinically and histomorphometrically and results analyzed by MINITABE 13.1 statistical package using ANOVA test. RESULTS: Animals underwent distraction showed obvious changes in condylar surface contour related to length of the follow up period, compared to the control; these changes seemed to be partly reversible. The most pronounced observation was the irregularities and resorption in the anterior part of the condylar cartilage and the subcondylar bone. Moreover, at the first two weeks, the area of resorption was invaded by large number of osteoclasts and chronic inflammatory cells which declined later in the 3rd and 4th weeks and replaced with osteoblastic activities. CONSLUSION: These experimental data showed that distraction rate of 3 mm per day may lead to degenerative or even early arthritic changes in the TMJ condylar cartilage in the 1st and 2nd post-distraction weeks. However, all condyles showed adaptive and remodeling sings in the following 3rd and 4th weeks

Social media in undergraduate medical education: A systematic review.

INTRODUCTION: There are over 3.81 billion worldwide active social media (SoMe) users. SoMe are ubiquitous in medical education, with roles across undergraduate programmes, including professionalism, blended learning, well being and mentoring. Previous systematic reviews took place before recent explosions in SoMe popularity and revealed a paucity of high-quality empirical studies assessing its effectiveness in medical education. This review aimed to synthesise evidence regarding SoMe interventions in undergraduate medical education, to identify features associated with positive and negative outcomes. METHODS: Authors searched 31 key terms through seven databases, in addition to references, citation and hand searching, between 16 June and 16 July 2020. Studies describing SoMe interventions and research on exposure to existing SoMe were included. Title, abstract and full paper screening were undertaken independently by two reviewers. Included papers were assessed for methodological quality using the Medical Education Research Study Quality Instrument (MERSQI) and/or the Standards for Reporting Qualitative Research (SRQR) instrument. Extracted data were synthesised using narrative synthesis. RESULTS: 112 studies from 26 countries met inclusion criteria. Methodological quality of included studies had not significantly improved since 2013. Engagement and satisfaction with SoMe platforms in medical education are described. Students felt SoMe flattened hierarchies and improved communication with educators. SoMe use was associated with improvement in objective knowledge assessment scores and self-reported clinical and professional performance, however evidence for long term knowledge retention was limited. SoMe use was occasionally linked to adverse impacts upon mental and physical health. Professionalism was heavily investigated and considered important, though generally negative correlations between SoMe use and medical professionalism may exist. CONCLUSIONS: Social media is enjoyable for students who may improve short term knowledge retention and can aid communication between learners and educators. However, higher-quality study is required to identify longer-term impact upon knowledge and skills, provide clarification on professionalism standards and protect against harms