The Experts below are selected from a list of 2310 Experts worldwide ranked by ideXlab platform
Namjong Paik - One of the best experts on this subject based on the ideXlab platform.
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multiple peripheral nerve compressions related to malignantly transformed hereditary multiple exostoses
Muscle & Nerve, 2000Co-Authors: Namjong PaikAbstract:Autosomal dominantly transmitted hereditary multiple exostoses is an uncommon disorder consisting of multiple projections of bone capped by cartilage. The lesions are most numerous in the metaphyses of long Bones but may appear on Flat Bones. Sarcomatous transformation occurs in 1-25% of patients. We report a 33-year-old man with sciatica, previously diagnosed as hereditary multiple exostoses, presenting with multiple peripheral nerve compressions. Electrodiagnostic studies showed profound axon-loss multiple neuropathies involving the sciatic, superior gluteal, and inferior gluteal nerves. Magnetic resonance imaging of the left pelvis showed a large mass in the sacral area that was suggestive of a chondrosarcoma. An open intralesional excision biopsy confirmed chondrosarcoma transformed from chondromatosis. Excision of the lesion was effective in eliminating the impingement of nerves and retarding progressive osseous growth. We suggest that malignant transformation be suspected in cases with focal compression neuropathy of patients known to have multiple exostoses. Osteochondroma as a possible cause for compression neuropathy is discussed.
Diego Alexander Garzonalvarado - One of the best experts on this subject based on the ideXlab platform.
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Flat Bones and sutures formation in the human cranial vault during prenatal development and infancy a computational model
Journal of Theoretical Biology, 2016Co-Authors: F J Burgosflorez, M E Gavilanalfonso, Diego Alexander GarzonalvaradoAbstract:The processes of Flat Bones growth, sutures formation and interdigitation in the human calvaria are controlled by a complex interaction between genetic, biochemical and environmental factors that regulate bone formation and resorption during prenatal development and infancy. Despite previous experimental evidence accounting for the role of the main biochemical factors acting on these processes, the underlying mechanisms controlling them are still unknown. Therefore, we propose a mathematical model of the processes of Flat bone and suture formation, taking into account several biological events. First, we model the growth of the Flat Bones and the formation of sutures and fontanels as a reaction diffusion system between two proteins: TGF-β2 and TGF-β3. The former is expressed by osteoblasts and allows adjacent mesenchymal cells differentiation on the bone fronts of each Flat bone. The latter is expressed by mesenchymal cells at the sutures and inhibits their differentiation into osteoblasts at the bone fronts. Suture interdigitation is modelled using a system of reaction diffusion equations that develops spatio-temporal patterns of bone formation and resorption by means of two molecules (Wnt and Sclerostin) which control mesenchymal cells differentiation into osteoblasts at these sites. The results of the computer simulations predict Flat bone growth from ossification centers, sutures and fontanels formation as well as bone formation and resorption events along the sutures, giving rise to interdigitated patterns. These stages were modelled and solved by the finite elements method. The simulation results agree with the morphological characteristics of calvarial Bones and sutures throughout human prenatal development and infancy.
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growth of the Flat Bones of the membranous neurocranium
Computer Methods and Programs in Biomedicine, 2013Co-Authors: Diego Alexander Garzonalvarado, Andres Gonzalez, Maria Lucia GutierrezAbstract:This article assumes two stages in the formation of the Bones in the calvaria, the first one takes into account the formation of the primary centers of ossification. This step counts on the differentiation from mesenchymal cells into osteoblasts. A molecular mechanism is used based on a system of reaction-diffusion between two antagonistic molecules, which are BMP2 and Noggin. To this effect we used equations whose behavior allows finding Turing patterns that determine the location of the primary centers. In the second step of the model we used a molecule that is expressed by osteoblasts, called Dxl5 and that is expressed from the osteoblasts of each Flat bone. This molecule allows bone growth through its borders through cell differentiation adjacent to each bone of the skull. The model has been implemented numerically using the finite element method. The results allow us to observe a good approximation of the formation of Flat Bones of the membranous skull as well as the formation of fontanelles and sutures.
I A Dubrovin - One of the best experts on this subject based on the ideXlab platform.
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forensic medical estimation of gunshot fractures of the Flat Bones
Sudebno-meditsinskaia ekspertiza, 2012Co-Authors: I A Dubrovin, I A DubrovinaAbstract:The principal characteristics of the investigations into the mechanisms of gunshot injuries are considered. The general and peculiar features of gunshot fractures and the pathological processes underlying them are discussed. The theory of bullet impact effect put forward by the Russian surgeons in the late XIXth century is verified. The explanation is proposed for the physical nature of direct and side impacts and the phenomenon of a temporary oscillating cavity from the standpoint of the theory of bullet impact effect. The new forensic medical criteria for the gunshot origin of an injury have been developed that allow the gunshot distance and the geometric characteristics of the bullet to be determined. A methodological basis for the determination of the long-range gunshot distance has been created. The results of the present study may be of interest for criminal lawyers and military specialists.
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mechano and morphogenesis of gunshot fractures in the Flat Bones
Sudebno-meditsinskaia ekspertiza, 2006Co-Authors: I A DubrovinAbstract:Gunshot fractures in Flat Bones, bullet defects in the continuum were studied in experiment. The laws of gunshot fracture formation were formulated. In far distance, bullet has a direct and radial blow action. The direct blow induces comminution and disintegration of the bone tissue with dislocation of bone fragments; radial blow potentiates bone destruction. Morphological characteristics of gunshot fractures of Flat Bones depend on the force of the direct and radial impact action and can be used for estimation of the far shot distance, kinetic energy and shape of the head of the shell.
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gun shot fractures of the Flat Bones mechanisms of development
Sudebno-meditsinskaia ekspertiza, 2006Co-Authors: I A Dubrovin, I A Dubrovina, Pigolkin IuiAbstract:We studied experimental gun-shot fractures in the Flat Bones due to slow-speed bullets. We have found common features information of gun-shot fractures. Fragmentation of the bone tissue occurs within a Herz cone surrounded by ring-shape fissures as a result of crossing over of subsurface and median fissures. Invasion of the bullet into the bone thickness is accompanied with shift abruption of bone fragments, their parallel transfer, rotation and radial movement. In the injury with slow-speed blunt-pointed bullets the fragments move, as a rule, by parallel transfer and rotation. In the injury with sharp-pointed bullets, of a key importance is radial movement of the fragments changing characteristics of the gun-shot fracture.
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expert evaluation of the gunshot distance based on the volume of wound canal in Flat Bones
Sudebno-meditsinskaia ekspertiza, 2004Co-Authors: I A Dubrovina, I A Dubrovin, A B ArsenevAbstract:Different-distance experimental shots were made from a rifled gun at Flat Bones. Those shot distances were established, at which the wound canal had the smallest volume, and, at which entry and exit holes were virtually identical and matched the bullet diameter. A bigger shot distance was associated with an increasing volume of the wound canal caused by a bigger exit hole. A smaller shot distance led, also, to an increasing volume of the wound canal caused by bigger entry and exit holes. The volume of the wound canal in Flat Bones can be used as a reliable criterion in assessing the shot distance.
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the influence of a shot distance on a profile of a wound canal in Flat Bones
Sudebno-meditsinskaia ekspertiza, 2003Co-Authors: I A Dubrovin, I A DubrovinaAbstract:Experimental shots were made from rifled weapons, from different distances, at isolated Flat Bones. There was established a significantly increased angle of the axial section of the cone-shaped defect due to the expanding sizes of the exit part of the wound canal (WC) and of the outlet opening as the shot distances increased. An expert's evaluation is offered to assess a shot distance involving the WC profile and by calculating an angle of the axial section of the cone-shaped defect on the basis of the inlet and outlet sizes and of the Flat-bone thickness.
Ivo Jajic - One of the best experts on this subject based on the ideXlab platform.
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radiological changes of short and Flat Bones in primary hypertrophic osteoarthropathy
Annals of the Rheumatic Diseases, 1998Co-Authors: Zrinka Jajic, Ivo JajicAbstract:Hypertrophic osteoarthropathy (HO) is defined as a syndrome characterised by finger clubbing and periostosis of long Bones.1 It is classified into primary (PHO) and secondary hypertrophic osteoarthropathy (SHO).2 To establish the HO diagnosis, finger clubbing and periostosis of long Bones must be present.2 Cases of PHO have not been frequently reported in the medical literature.3 HO cases have recently been more described, since HO was classified into the bone and cartilage group of diseases according to the international classification of rheumatic diseases.4 We formed a large group of patients in whom changes of Flat Bones were found. The analysis was based on a group of patients with PHO from 1970 to 1996. Over 26 years, a total of 76 patients …
Surekha D Shetty - One of the best experts on this subject based on the ideXlab platform.
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solitary osteochondroma in the body of the pubic bone a cadaveric case report
Anatomy & Cell Biology, 2018Co-Authors: Satheesha B Nayak, Srinivasa Rao Sirasanagandla, Srilatha Parampalli Srinivas, Narendra Pamidi, Naveen Kumar, Surekha D ShettyAbstract:Osteochondromas develop as cartilaginous nodules in the periosteum of Bones. They are the commonest benign tumors of the skeleton, generally observed in the long Bones. Rarely, they are also found in the axial skeleton, Flat Bones of skull and facial Bones. During a regular dissection, we came across a solitary osteochondroma in posterior surface of the body of the right pubic bone. Histopathology of the bony projection confirmed the typical features of the osteochondroma. The symptomatic osteochondromas are usually evaluated during radiographic examination. Though, the observed osteochondroma is relatively smaller its unusual location is remarkable and knowledge of occurrence of such nodules is clinically important during the diagnosis and planning of treatment.