Intraosseous arterial alteration of maxilla influencing implant-related surgeries.

OBJECTIVES To investigate the intraosseous arterial pathways and anastomoses in the alveolar aspects of the maxilla in order to better understand the arterial scattering pattern. MATERIALS AND METHODS Eleven cadavers were selected for macroscopic intraosseous arterial analyses by corrosion casting. The red-colored acrylic resin was injected into the external carotid arteries. The specimens were kept in an enzymatic solution at 36 °C for about 60 days, depending on the process progression. After removal of the soft tissues and drying, the bone was macerated by potassium hydroxide to analyze the course and the mean diameters of the intraosseous anastomoses. RESULTS Vertico-oblique and horizontal intraosseous arteries and anastomoses between the greater palatine-, posterior superior alveolar-, and infraorbital arteries were detected. The vertico-oblique anastomoses were found on the anterolateral wall of the maxilla and the alveolar crest with a mean diameter of 0.46 mm; nevertheless, the horizontal (transalveolar) anastomoses were identified in the interdental septum/alveolar crest with the mean diameter of 0.41 mm. From the horizontal anastomoses, small intraseptal branches supplied the territory of the alveolar socket in various directions. CONCLUSIONS The localization of intraosseous arterial anastomoses is critical in implant-related surgeries, predominantly to maintain proper circulation. CLINICAL RELEVANCE Based on vertico-oblique and transalveolar anastomoses, simultaneous buccal- and palatal flap elevation (particularly on the palatal side) should be avoided to minimize patient morbidity and intra- or postoperative complications. Moreover, preserving transverse loops in the interdental septum is essential during implant surgeries, which can significantly influence collateral periosteal and osteal circulation to prevent ischemia

Comparative Endoscopic Anatomic Description of the Mitral Valvular Complex: a Cadaveric Study

Background We compared the aortic, left atrial, and apical approaches to visualize the mitral valve with the goal to investigate the endoscopic anatomy and give exact step-by-step descriptions of these views. Materials and Methods The mitral valvular complex of human cadaveric fresh hearts was investigated from three approaches using 0, 30, and 70 degrees rigid endoscopic optics. In 30 cases after the removal of the hearts, the endoscopes were introduced directly into the aortic root through an aortotomy, left atrium through a standard atriotomy, and apex of the heart through a transmural incision. In 10 cases, the in situ visualization was performed using standard surgical approaches, such as partial upper ministernotomy, right and left minithoracotomy. The investigation was performed first with the mitral valve open, then the left ventricle was filled with saline, and the valve was closed by clamping the aorta. Results For the visualization of ventricular surfaces of the mitral leaflets and the subvalvular apparatus, the apical approach was most optimal. The aortic approach had limitations at the posterior leaflet. Using the atrial approach, we did not obtain any direct visual information about the subvalvular apparatus with the valve closed. The atrial surfaces of the leaflets were best visible using both the atrial and apical approaches with the mitral valve open. In the case of a closed valve, the apical approach did not allow for an investigation of the atrial surfaces. The aortic approach was useful to visualize the atrial surface of the posterior leaflet with an opened valve. Conclusion In mitral valve repairs through the left atrium, an additional aortic or apical view could be useful to obtain functional information about the subvalvular apparatus by the sealing probe

Synthesis and Cytostatic Effect of 3'-deoxy-3'-C-Sulfanylmethyl Nucleoside Derivatives with d-xylo Configuration

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Strategic Positioning of Connexin36 Gap Junctions Across Human Retinal Ganglion Cell Dendritic Arbors

Connexin36 (Cx36) subunits form gap junctions (GJ) between neurons throughout the central nervous system. Such GJs of the mammalian retina serve the transmission, averaging and correlation of signals prior to conveying visual information to the brain. Retinal GJs have been exhaustively studied in various animal species, however, there is still a perplexing paucity of information regarding the presence and function of human retinal GJs. Particularly little is known about GJ formation of human retinal ganglion cells (hRGCs) due to the limited number of suitable experimental approaches. Compared to the neuronal coupling studies in animal models, where GJ permeable tracer injection is the gold standard method, the post-mortem nature of scarcely available human retinal samples leaves immunohistochemistry as a sole approach to obtain information on hRGC GJs. In this study Lucifer Yellow (LY) dye injections and Cx36 immunohistochemistry were performed in fixed short-post-mortem samples to stain hRGCs with complete dendritic arbors and locate dendritic Cx36 GJs. Subsequent neuronal reconstructions and morphometric analyses revealed that Cx36 plaques had a clear tendency to form clusters and particularly favored terminal dendritic segments

Region Specific Differences of Claudin-5 Expression in Pediatric Intracranial Ependymomas: Potential Prognostic Role in Supratentorial Cases

Ependymomas are common pediatric brain tumors that originate from the ependyma and characterized by poor prognosis due to frequent recurrence. However, the current WHO grading system fails to accurately predict outcome. In a retrospective study, we analyzed 54 intracranial pediatric ependymomas and found a significantly higher overall survival in supratentorial cases when compared to infratentorial tumors. Next we performed region-specific immunohistochemical analysis of the ependyma in neonatal and adult ependyma from the central canal of spinal cord to the choroid plexus of lateral ventricles for components of cell-cell junctions including cadherins, claudins and occludin. We found robust claudin-5 expression in the choroid plexus epithelia but not in other compartments of the ependyma. Ultrastructural studies demonstrated distinct regional differences in cell-cell junction organization. Surprisingly, we found that 9 out of 20 supratentorial but not infratentorial ependymomas expressed high levels of the brain endothelial tight junction component claudin-5 in tumor cells. Importantly, we observed an increased overall survival in claudin-5 expressing supratentorial ependymoma. Our data indicates that claudin-5 expressing ependymomas may follow a distinct course of disease. The assessment of claudin-5 expression in ependymoma has the potential to become a useful prognostic marker in this pediatric malignancy

MORFOMETRIAI KUTATÁSOK AZ EMBERI ARC TÖRTÉNETI EMBERTANI, IGAZSÁGÜGYI, ÉS GYÓGYÁSZATI CÉLÚ 3D REKONSTRUKCIÓJÁNAK FEJLESZTÉSÉHEZ = MORPHOMETRIC RESEARCH FOR DEVELOPING THE 3D FACIAL RECONSTRUCTION METHOD FROM THE PURPOSE OF HISTORIC- AND FORENSIC ANTHROPOLOGY, AND MEDICINE

Létrehoztuk a FACE-R 3D koponya és- arc kutatói adatbázist, amely 425 élő vizsgálati személy és 5 kadáver fej adatait tartalmazza. Mysql adatbázisban tároljuk az adatállományokat, valamint a feldolgozás során nyert plusz információkat. Az adatbázis nemzetközi viszonylatban is egyedülálló, mert az illesztett 3D koponya CT-és arc modellek létrehozásával kiküszöböltük a fekvő helyzetben készülő gravitációs elmozdulást a CT-felvételeken. Előzetes elemzést végeztünk 60 egyén adatain 3D virtuális antropológiai és geometrikus morfometriai módszerekkel. Szignifikáns alaki összefüggéseket találtunk a koponya és az arc között. 20 egyén koponyáján feltáró EFA (Elliptic Fourier Analysis) elemzést végeztünk. Statisztikai módszerrel hiányzó adatpótlást végeztünk Szt. László király állkapocs rekonstrukciójához. A fekvő és- ülő helyzetű arcmodellek közti eltérés statisztikai vizsgálatára 3D biometriai elemzést végeztünk. Az arc matematikai modellezéséhez szükséges módszertani fejlesztések során standardizáltuk a 3D modelleket és programot írtunk a 3D felületi változékonyság jellemzésére, a min-max görbületi görbesereg meghatározására. Kidolgoztuk a koponya és az arc 3D „karakterisztikus geometriai modelljének” koncepcióját. Kísérleteket végeztünk a 3D külső orr rekonstrukció matematikai modelljének létrehozása. Elasztikus regisztrációs eljárást alkalmaztunk az arc modellezéséhez szükséges kiindulási adatok (3D template-ek) létrehozására. | We created the „FACE-R” 3D skull- and face research database, that is contain 425 living individuals’ and 5 cadavers’ head data. We stored the data files and the additional information in Mysql database. Thanks to the aligned 3D skull- and face models, we were able to eliminate the gravitational shift on CT-scans — recorded in supine position —, the database is unique in international relations as well. In the framework of the pilot study the virtual anthropological data collection and geometric morphometric analysis was performed on 60 persons’ data. We uncovered significant shape correlations between the skulls- and the faces. We performed exploratory EFA (Elliptic Fourier Analysis) on 20 persons’ skulls. Missing data complementation was accomplished applying statistical method for virtual mandible reconstruction of St. Laszlo, the Hungarian king. We carried on biometric analysis to uncover differences between the supine- and upright positioned 3D face models. In the framework of methodological development necessary for mathematical modelling the face, we standardized the 3D models than programmed an application for determine the min-max. curvature on the 3D skull- and face model surfaces. We worked out the concept of the „3D Characteristic Geometric Model” of the skulls and faces. We made some attempts to create a mathematical model for the 3D external nose reconstruction. We produced the 3D input templates for modelling the face applying „elastic registration” method

FEM stress analysis of a barrel reamer

Horizontal Directional Drilling (HDD) is a method of installing underground pipelines, cables and service conduit through trenchless methods. The tools and techniques used in the HDD process are an outgrowth of the oil well drilling industry, too. Installation of a pipeline by HDD is a three stages process. The first stage consists of directionally drilling a small diameter pilot hole along a designed directional path. Drilling fluid is pumped through the drill pipe to the drill bit where high pressure jets and the bit will grind the soils ahead of the drill stem. The second stage involves enlarging this pilot hole to a diameter suitable for installation of the pipeline. A reamer is pulled back and rotated while pumping drilling fluid to cut and remove solids to enlarge the hole. A kind of reamer is the subject of this paper. The final stage consists of pulling the pipeline back into the pre-reamed hole. The most important part of the mechanical analysis is to define the boundary conditions for operating situations when the tool is under maximum load. In this paper we present a helpful description for giving boundary conditions to perform the numerical simulation of a barrel reamer