Age-related changes in human tendo calcaneus collagen fibrils

The ruptures of tendo calcaneus often occur between the age of 30 - 45 years as described by several textbooks. It is also described that some diseases and drugs are said to be responsible in the etiology; however, there are no studies related with the detailed histological structure of collagen fibrils found in the tendon in the age groups of humans. In view thereof, this study was aimed to obtain further information on the etiology and to find an answer regarding the frequency of the ruptures occurring between the age of 30 - 45 years in humans. In the study, the biopsy specimens taken from 28 patients [ages 1 - 68 year] who had undergone surgery due to tendo calcaneus ruptures or achilloplasty operation were examined by transmission electron microscope. All the specimens were prepared according to routine electron microscopic tissue preparation technique. The patients were divided into 7 age groups [1 - 9, 10 - 19, 20 - 29, 30 - 39, 40 - 49, 50 - 59, >60 years] and there were 4 patients in each group. The transverse diameters of collagen fibers were measured from the ultra thin sections and statistical analysis of the results were performed. The study was carried out in the electron microscopy laboratory of the Anatomy Department of Hacettepe University, Ankara, Turkey between January 2004 and September 2004. The diameters of the collagen fibers were higher in the 20 - 29 year-old group compared to other groups and it showed a statistically significant difference. In patients who were in the 30 - 39 year-old group or older, the diameters of the collagen fibers were lesser than the 20 - 29 year-old group. However, an increase was observed in the collagen fibril concentration of these groups. In examination of the specimens of patients who were under 20-year-old, the diameter of the collagen fibers were less than the 20 - 29 year-old group. The electron microscopic appearance of the tissue sample of a one-year-old patient had a specific organization and in this patient, both the diameters and concentration of collagen fibers were less. We believe that the decrease in the diameters of collagen fibers of 30 - 45 year-old patients who are in the active period of their life, can play a role in the etiology of the frequency of tendo calcaneus ruptures similar to other etiologic factors

Quantitative analysis of myelinated axons of commissural fibers in the cat brain

There are limited data related to the number of commissural axons found in various species. Although the corpus callosum has been investigated in cat, there are no data on the number of its myelinated axons. Additionally, the number of myelinated axons of anterior, posterior and habenular commissures are not documented for the cat. Therefore, we aimed to examine the topographic distribution and regional numerical differences of myelinated axons in encephalic commissures of the cat. This study was carried out at the Faculty of Medicine, Hacettepe University, Ankara, Turkey, from March 2003 to July 2003. The myelinated axons of the encephalic commissures of one cat were counted in this study. In parts of the corpus callosum, a statistically significant difference was found between rostrum and genu, rostrum and truncus, genu and truncus, genu and splenium and truncus and splenium. However, no statistically significant difference was found between rostrum and splenium. When comparing the number of myelinated axons of anterior, posterior and habenular commissures, statistically significant differences were found between anterior and habenular commissures, and between posterior and habenular commissures. No statistically significant difference was found between anterior and posterior commissures. These numerical data, evaluated by quantitative analytical statistical methods, might be useful in filling the lack of information on the mean numbers of myelinated axons of different commissures. Knowledge of the number of myelinated axons in different parts of the corpus callosum may also be very important when performing surgical procedures of the corpus callosum, such as commissurectomies

Light and electron microscopic examination of human subungual tissue Glomus and lamellated bodies

There is only limited data related to the subungual glomus body. We therefore studied the structure of this organ, aiming to obtain further evidence. Additionally, we encountered undefined receptor like structures in close association with these glomus cells, named them as lamellated bodies and examined both of the structures at light and electron microscopic levels. This study was carried out at the Faculty of Medicine, Hacettepe University, Ankara, Turkey, during the time period May 2001 to March 2002. In this study, the subungual tissues of 4 patients were examined. Within subungual tissue, 2 groups of morphologically significant structures were determined by light microscopy. The first structure was described as glomus body. It was characterized as an encapsulated structure, rich in rounded clear cells filling its central compartment. The latter structure having a lamellated appearance was described as lamellated body. In the electron microscopic examination, lamellated bodies were characterized by central filament rich large cells and surrounding cytoplasmic processes of ensheathing cells, some of which were vacuolated. Glomus bodies were surrounded by a capsule and centrally located numerous rounded cells which reflected the structural features of an active cell. The lamellated bodies are very unusual structures and they are not found in any other part of the body. The structural organization of the ensheathing cells in the lamellated bodies greatly resembles many skin associate receptors. Therefore, we planned future studies by using immunohistochemistry, to reveal nervous elements for structural contribution

Three-dimensional structure of the modiolus A computerized reconstruction study

Modiolus is a dense, compact, mobile fibromuscular structure, reachable by the dissection of buccolabial musculature. We undertook this study to provide detailed information about the macroscopic and microscopic anatomy of modiolus and its 3-dimensional [3-D] shape. Fifteen micrometer thick serial sections were taken from the fixed cadaveric tissue samples and then stained with hematoxylin and eosin, and Massons' trichrome stain. Stained sections were photographed digitally and images were transferred to computer medium to perform 3-D reconstruction. The study was carried out in the dissection lab of the Anatomy Department of Hacettepe University, Ankara, Turkey between 2002 and 2003. The modiolus appears to be a tortuous, blunt conelike structure, extending vertically from the buccal mucosa to the dermis of the skin. The base of the cone is adjacent to the mucosa. As the structure has great clinical importance, and satisfactory complete 3-D analysis of the subject is not yet available; we believe that our study presenting the histological and 3-D description of the modiolus will be of great help to surgeons for satisfactory esthetic and functional results during surgical operations related to the oral commissure