125 research outputs found

    Magnetic resonance imaging for diagnosis of bipartite patella : usefulness and relationship with symptoms

    Get PDF
    Purpose: Bipartite patella is a rare developmental variation of the knee cap. We aimed to identify the magnetic resonance imaging (MRI) features of bipartite patella and evaluate the association with clinical symptoms. Material and methods: MRI exams of 61 patients with bipartite variant were evaluated for types of bipartite patella, oedema around the synchondrosis, bipartite fragment height (FH), distance between the fragment and the patella (FPD), and signal characteristics within the synchondrosis. The study was designed with two observers in order to achieve intra- and interobserver compliance. Any other major knee pathologies that can cause pain were also recorded. Results: Of the 61 participants the average age was 40.1 ± 14.3 years, 44 were males, and 17 were females. Fifty-nine of the bipartite fragments were located at the superolateral quadrant of the patella. There was oedema at the bipartite area in 35 patients. Ten of these patients had no major MRI diagnosis other than oedema, and they were classified as the symptomatic group. The age of the patients in the symptomatic group was statistically lower than in the asymptomatic group (p 0.05). High concordance correlation coefficients were observed on measurements Conclusions: MRI of the knee is highly accurate in evaluation of bipartite patella. To our knowledge; a detailed MRI analysis, like in our study, has not previously been performed, and our report is unique in showing that the symptomatic occurrence of bipartite patella is statistically higher in young patients

    Anthropometric measurements of the orbita and gender prediction with three-dimensional computed tomography images

    Get PDF
    Background: The aim of the study was to investigate the orbital anthropometric variations in the normal population using three-dimensional computed tomography (3D-CT) images and to define the effects of age and gender on orbital anthropometry.Materials and methods: Three-dimensional orbita CT of 280 patients, obtained for various reasons, were retrospectively evaluated in 772-bed referral and tertiary-care hospital between April 2011 and June 2012. Using 3D images, orbital width, height, biorbital-interorbital diameter and orbital index were measured. Measurements were obtained comparing right and left sides and male to female. The relation of the results with age and gender was analysed.Results: Right orbit was found to be wider than left (p < 0.0001). Male patients had wider (p < 0.0001) and higher (p = 0.0001) orbits. Right orbital index was found to be smaller than the left one (p = 0.005). No differences were found between the genders in terms of right and left orbital indexes (p > 0.05). Biorbital (p < 0.0001) and interorbital (p = 0.01) widths were found to be higher in males. There was no relation between the age change and the parameters defined (p > 0.05).Conclusions: No relation was found between age and orbital measurements. It was concluded that orbital images obtained with 3D-CT may be used as a method for gender evaluation

    Prediction of nasal morphology in facial reconstruction: Validation and recalibration of the Rynn method

    Get PDF
    Background Prediction of the nose from the skull remains an important issue in forensic facial approximation. In 2010, Rynn et al. published a method of predicting nose projection from the skull. With this method, three craniometric measurements (x, y, z) are taken, and these are then used in regression formulae to estimate the nasal dimensions. Aim The purpose of this study was to examine and test the accuracy of the Rynn et al. method and if necessary to adapt the formulae for this population. Subjects and methods A sample of 90 CT scans of Turkish adults was used in the study. The actual and predicted dimensions were compared using t-test. The age of the individuals ranged from 20 to 40 years by sex. Results The descriptive statistics and correlations were calculated, and the actual and predicted measurements were compared. The differences between the actual and predicted values were statistically significant (p < 0.01), with −1 mm for males and −1.5 mm for females. Validation accuracies ranged from 76 to 92% in females and 72 to 82% in males. Recalibration equation accuracies ranged from 88 to 100% in females and 90 to 100% in males. Conclusion The results showed that the recalibration of the Rynn et al. method and its formulae gave satisfactory results with less error and can be employed in facial approximation cases

    The value of proton mr-spectroscopy in the differentiation of brain tumours from non-neoplastic brain lesions

    Get PDF
    Purpose: Our aim was to evaluate the efficacy of Proton-MR Spectroscopy for the differentiation of cranial masses from non-neoplastic brain disorders. Material and method: 33 patients with intracranial mass lesions, 29 patients with non-neoplastic brain lesions: Ischemic-demyelinating-metabolic-benign cystic mass group; As a whole 62 patients: 30 males and 32 females were included in this study. Results: In brain tumours, average Cho/NAA ratio 2.84-NAA/Cr ratio was 0.97, Cho/Cr ratio 2.42 and Cho/MI ratio was 3.51. In non-neoplastic group; NAA/Cr ratio was extremely higher than tumour group, the other ratios were far lower than cranial mass lesions. Average Cho/NAA ratio: 0.50 ± 0.15, Cho/Cr ratio: 1.05 ± 0.14, Cho/MI ratio: 1.07 ± 0.73. Conclusion: Higher Cho/NAA and Cho/MI ratios with lower NAA/Cr ratio were most likely to be malignant. Additional lipid and lactate peaks were generally seen in malignant group

    SBE6, a novel long-range enhancer involved in driving Sonic Hedgehog expression in neural progenitor cells

    Get PDF
    The expression of genes with key roles in development is under very tight spatial and temporal control, mediated by enhancers. A classic example of this is the sonic hedgehog gene (<i>Shh</i>) that plays a pivotal role in the proliferation, differentiation and survival of neural progenitor cells both <i>in vivo</i> and <i>in vitro. Shh</i> expression in the brain is tightly controlled by several known enhancers that have been identified through genetic, genomic and functional assays. Using chromatin profiling during the differentiation of embryonic stem cells to neural progenitor cells, here we report the identification of a novel long-range enhancer for Shh-Shh-brain-enhancer-6 (SBE6) that is located 100 kb upstream of <i>Shh</i> and that is required for the proper induction of <i>Shh</i> expression during this differentiation programme. This element is capable of driving expression in the vertebrate brain. Our study illustrates how a chromatin-focused approach, coupled to <i>in vivo</i> testing, can be used to identify new cell-type specific <i>cis</i>-regulatory elements and points to yet further complexity in the control of <i>Shh</i> expression during embryonic brain development

    DESIGN OF GEODETIC NETWORKS BASED ON OUTLIER IDENTIFICATION CRITERIA: AN EXAMPLE APPLIED TO THE LEVELING NETWORK

    Get PDF
    We present a numerical simulation method for designing geodetic networks. The quality criterion considered is based on the power of the test of data snooping testing procedure. This criterion expresses the probability of the data snooping to identify correctly an outlier. In general, the power of the test is defined theoretically. However, with the advent of the fast computers and large data storage systems, it can be estimated using numerical simulation. Here, the number of experiments in which the data snooping procedure identifies the outlier correctly is counted using Monte Carlos simulations. If the network configuration does not meet the reliability criterion at some part, then it can be improved by adding required observation to the surveying plan. The method does not use real observations. Thus, it depends on the geometrical configuration of the network; the uncertainty of the observations; and the size of outlier. The proposed method is demonstrated by practical application of one simulated leveling network. Results showed the needs of five additional observations between adjacent stations. The addition of these new observations improved the internal reliability of approximately 18%. Therefore, the final designed network must be able to identify and resist against the undetectable outliers – according to the probability levels

    Molecular marks for epigenetic identification of developmental and cancer stem cells

    Get PDF
    Epigenetic regulations of genes by reversible methylation of DNA (at the carbon-5 of cytosine) and numerous reversible modifications of histones play important roles in normal physiology and development, and epigenetic deregulations are associated with developmental disorders and various disease states, including cancer. Stem cells have the capacity to self-renew indefinitely. Similar to stem cells, some malignant cells have the capacity to divide indefinitely and are referred to as cancer stem cells. In recent times, direct correlation between epigenetic modifications and reprogramming of stem cell and cancer stem cell is emerging. Major discoveries were made with investigations on reprogramming gene products, also known as master regulators of totipotency and inducer of pluoripotency, namely, OCT4, NANOG, cMYC, SOX2, Klf4, and LIN28. The challenge to induce pluripotency is the insertion of four reprogramming genes (Oct4, Sox2, Klf4, and c-Myc) into the genome. There are always risks of silencing of these genes by epigenetic modifications in the host cells, particularly, when introduced through retroviral techniques. In this contribution, we will discuss some of the major discoveries on epigenetic modifications within the chromatin of various genes associated with cancer progression and cancer stem cells in comparison to normal development of stem cell. These modifications may be considered as molecular signatures for predicting disorders of development and for identifying disease states
    corecore