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1.
J Morphol ; 278(7): 884-895, 2017 07.
Article in English | MEDLINE | ID: mdl-28386944

ABSTRACT

A histological and morphometric analysis of human metacarpal and carpal anlagen between the 16th and 22nd embryonic weeks was carried out with the aim of studying the establishment of the respective anlage architecture. No differences in the pattern of growth were documented between the peripheral and central zones of the metacarpal epiphyses and those of the carpals. The regulation of longitudinal growth in long bone anlagen occurred in the transition zone between the epiphysis and the diaphysis (homologous to the metaphyseal growth plate cartilage in more advanced developmental stage of the bone). Comparative zonal analysis was conducted to assess the chondrocyte density, the mean chondrocyte lacunar area, the paired chondrocyte polarity in the orthogonal longitudinal and transverse planes, and the lacunar shape transformation in the metacarpal. In transition from epiphysis to diaphysis chondrocyte density decreased and mean lacunar area increased. No significant differences in the chondrocyte maturation cycle were observed between proximal/distal metacarpal epiphyses and the carpal anlagen. The number of paired chondrocyte oriented along the growth vector was significantly higher in both proximal/distal transition zones between epiphysis and diaphysis. Human metacarpals shared with experimental models (like mice and nonmammal tetrapods) an early common chondrocyte maturation cycle but with a different timing due to the slower embryonic and fetal developmental rate of human anlagen.


Subject(s)
Carpal Bones/embryology , Cartilage/embryology , Fetus/anatomy & histology , Hand/embryology , Metacarpal Bones/embryology , Cell Differentiation , Chondrocytes/cytology , Chondrocytes/ultrastructure , Diaphyses/ultrastructure , Epiphyses/ultrastructure , Humans
2.
BMC Musculoskelet Disord ; 15: 347, 2014 Oct 15.
Article in English | MEDLINE | ID: mdl-25319082

ABSTRACT

BACKGROUND: The cn/cn dwarf mouse is caused by a loss-of-function mutation in the natriuretic peptide receptor 2 (NPR-2) gene which helps positively regulate endochondral longitudinal bone growth. The gene mutation corresponds to that in the human skeletal dysplasia Acromesomelic Dysplasia Maroteaux type (AMDM). This study assesses histomorphometric, ultrastructural and radiographic correlates of the growth abnormality. METHODS: Ten litters of cn/cn and cn/+littermates at ages ranging from 2.5 to 6.5 weeks were studied by skeletal radiographs, histomorphometry and physeal ultrastructure. Skeletal radiographs were done on 2 cn/cn and 2 cn/+littermates at 5 weeks of age. Humeral, femoral, and tibial lengths were measured from 34 intact bones (17 cn/cn, 17 cn/+) at 2.5 to 6.5 weeks. Growth plate histomorphometry in 50 bones (26 cn/cn and 24 cn/+) determined the hypertrophic zone/entire physeal cartilage ratios in 204 sections (87 cn/+, 117 cn/cn) at 3 time periods (2.5-3, 4-4.5, and 6-6.5 weeks). Electron microscopy assessed 6 cn/cn and 6 cn/+age and site-matched physeal cartilage. RESULTS: Cn/cn mice were two thirds the size of the cn/+. Cn/cn bones were normal in shape or only minimally deformed except for the radius with mid-diaphyseal bowing. Length ratios of cn/cn humeri, femurs, and tibias were a mean of 0.65 (± 0.03, n = 34, 17 ratios) compared to cn/+bones. The main physeal abnormality was a markedly shortened hypertrophic zone with the ratio of hypertrophic zone to entire physis 0.17 (± 0.063) in the cn/cn and 0.30 (± 0.052) in the cn/+mice. Ratio assessments were similar comparing humeral, femoral, and tibial growth plates as were ratios from each of the 3 time periods. Ultrastructural assessments from the resting zone to the lower hypertrophic zone-metaphyseal junction showed no specific individual cell abnormalities in cn/cn compared to cn/+physes. CONCLUSIONS: The disorder causes a shortened physeal hypertrophic zone but normal ultrastructure of cn/cn chondrocytes points to abnormality primarily affecting the hypertrophic zone rather than a structural cell or matrix synthesis problem.


Subject(s)
Bone Diseases, Developmental/diagnostic imaging , Bone Diseases, Developmental/pathology , Bone and Bones/pathology , Bone and Bones/ultrastructure , Animals , Body Weight , Bone and Bones/diagnostic imaging , Chondrocytes/ultrastructure , Disease Models, Animal , Epiphyses/pathology , Epiphyses/ultrastructure , Femur/diagnostic imaging , Femur/pathology , Femur/ultrastructure , Growth Plate/pathology , Growth Plate/ultrastructure , Humans , Humerus/diagnostic imaging , Humerus/pathology , Humerus/ultrastructure , Mice , Mice, Mutant Strains , Radiography , Tibia/diagnostic imaging , Tibia/pathology , Tibia/ultrastructure
3.
Micron ; 58: 9-14, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24291507

ABSTRACT

We studied fine structures of the pineal organ of the tree sparrow, Passer montanus under the light, scanner electron and transmission electron microscopes. The pineal gland of the sparrow was found comprising of a pea-shaped epiphysis cerebri and a long tube-like pineal stalk that connects with the choroid plexus. Histological preparations of the pineal organ revealed that it contains follicles having pinealocytes of uniform size. The enlarged images of the gland using the SEM showed distinct granular structures or cells protruding from the surface of the epiphysis cerebri. The choroid plexus possessed varying numbers of irregular ridges and furrows. The observation under TEM revealed rounded nucleus and mitochondria in the pinealocytes. Groups of small size vesicles were also seen scattered throughout the perinuclear cytoplasm. Numbers of microtubules were found running parallel to each other. Blood capillaries that supply blood to the pineal organ were also visible in the sections. The morphology of the pineal organ of tree sparrow showed similarity with those of the other birds in possessing elongated epiphysis cerebri which remains connected to choroid plexus through a stalk. The tree sparrow resembled with some passerine birds in possessing saccular type of pineal organ having elongated tubular structure with a central lumen and a thick follicular wall. The pineal organ of the tree sparrow, thus, differed from those reported in non-passerine birds with tubulo-follicular or solid type of pineal organ. The presence of saccular pineal organ in the subtropical tree sparrow, as reported in other passerine birds elsewhere indicates the conservation of the structural organization of the pineal organ in passerine birds.


Subject(s)
Epiphyses/anatomy & histology , Epiphyses/ultrastructure , Sparrows/anatomy & histology , Animals , Histocytochemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission
4.
J Biomed Mater Res A ; 100(9): 2278-86, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22499413

ABSTRACT

The use of magnetism in tissue engineering is a very promising approach, in fact magnetic scaffolds are able not only to support tissue regeneration, but they can be activated and work like a magnet attracting functionalized magnetic nanoparticles (MNPs) injected close to the scaffold enhancing tissue regeneration. This study aimed to assess the in vivo biocompatibility and osteointegrative properties of novel magnetic scaffolds. Two hydroxyapatite/collagen (70/30 wt %) magnetic scaffolds were magnetized with two different techniques: direct nucleation of biomimetic phase and superparamagnetic nanoparticles (MNPs) on self-assembling collagen fibers (MAG-A) and scaffold impregnation in ferro-fluid solution (MAG-B). Magnetic scaffolds were implanted in rabbit distal femoral epiphysis and tibial mid-diaphysis. Histopathological screening showed no inflammatory reaction due to MNPs. Significantly higher bone healing rate (ΔBHR) results were observed in MAG-A in comparison to MAG-B. Significant differences were also found between experimental times with an increase in ΔBHR from 2 to 4 weeks for both scaffolds in trabecular bone, while only for MAG-B (23%, p < 0.05) in cortical bone. The proposed magnetic scaffolds seem to be promising for magnetic guiding in orthopedic tissue engineering applications and they will be suitable to treat also several pathologies in regenerative medicine area.


Subject(s)
Bone Regeneration , Bone Substitutes/chemistry , Collagen/chemistry , Durapatite/chemistry , Magnets/chemistry , Tissue Scaffolds/chemistry , Absorbable Implants , Animals , Bone Substitutes/metabolism , Collagen/metabolism , Diaphyses/physiology , Diaphyses/surgery , Diaphyses/ultrastructure , Durapatite/metabolism , Epiphyses/physiology , Epiphyses/surgery , Epiphyses/ultrastructure , Femur/physiology , Femur/surgery , Femur/ultrastructure , Magnetite Nanoparticles/chemistry , Male , Rabbits , Tibia/physiology , Tibia/surgery , Tibia/ultrastructure , Tissue Engineering/methods
5.
Int. j. morphol ; 30(1): 258-262, mar. 2012. ilus
Article in English | LILACS | ID: lil-638796

ABSTRACT

From a biomechanical standpoint, bone geometry and density are factors correlated to the bone resistance of the femur when supporting body weight, with geometric parameters like the diameter of the femoral head and neck, the length of the femoral neck, and the femoral neck angle as determinant factors in the incidence of hip fractures, which increase in frequency and seriousness in osteoporotic patients. In Chile, morphometric data that contributes to relating the anatomy of the proximal epiphysis of the femur as an associated factor in hip fractures does not exist; likewise, there are no anthropometric indexes that may contribute to the forensic sciences. The purpose of this study is to establish average measurements of the proximal epiphysis of the femur in the adult Chilean population. Descriptive Study. The proximal epiphyses of 81 dry adult femurs were analyzed (44 right and 37 left bones), measuring the following parameters: length of the femoral neck (LN), femoral neck angle (FNA), circumference of the femoral head (CH) and circumference of the femoral neck (CN). The statistical relationship between the measurements and the side of each sample was analyzed (t-test p=0.05). The average lengths were LN= 3.59cm (+/- 0.43 cm); FNA= 124.17 (+/- 6.37), CH= 14.34 cm (+/- 1.27 cm) and CN= 9.7 cm (+/- 0.87 cm). No significant differences between the left and right sides were found. Average numbers were obtained for the anatomy of the proximal femoral epiphysis from a sample in the Chilean population. With the data obtained, we propose to carry out anatomo-clinical, epidemiologic and forensic studies in this population.


Desde un punto de vista biomecánico, la geometría y la densidad ósea son factores correlacionados con la resistencia del hueso del fémur al apoyar el peso corporal, con los parámetros geométricos, como el diámetro de la cabeza femoral y el cuello, la longitud del cuello del fémur, y el ángulo del cuello femoral factores determinantes en la incidencia de fracturas de cadera, que aumentan en frecuencia y gravedad en los pacientes con osteoporosis. En Chile, no existen datos morfométricos que relacionen la anatomía de la epífisis proximal del fémur como un factor asociado a las fracturas de cadera ni índices antropométricos que pueden contribuir a las ciencias forenses. El propósito de este estudio es establecer las medidas promedio de la epífisis proximal de fémur en población adulta chilena. Estudio Descriptivo. Se analizaron la epífisis proximal de 81 fémures adultos secos (44 derechos y 37 izquierdos), midiendo los siguientes parámetros: longitud del cuello femoral (LC) , ángulo cérvico-diafisiario femoral (ACD), circunferencia de la cabeza femoral (CCa) y circunferencia del cuello femoral (CCu). Se analizó la relación estadística de las medidas con el lado de cada muestra (test Chi cuadrado p:0,05) Las longitudes promedios fueron LC: 3,59 cm (+/- 0,43 cm); ACD: 124,17 (+/- 6,37 cm); CCa: 14,34 cm (+/- 1,27 cm) y CCu: 9,7 cm (+/- 0,87 cm). No se encontraron diferencias significativas entre el lado derecho e izquierdo. Los resultados proponen la necesidad de realizar estudios anatomo-clínicos y epidemiológicos actualizados en población chilena donde la geometría de la epífisis proximal del fémur se incluya dentro del análisis.


Subject(s)
Female , Femur Head/anatomy & histology , Femur Head/growth & development , Femur Head/innervation , Femur Head/ultrastructure , Femur Neck/anatomy & histology , Femur Neck/innervation , Femur Neck/ultrastructure , Epiphyses/anatomy & histology , Epiphyses/ultrastructure , Chile , Forensic Sciences/methods , Hip Fractures/diagnosis , Hip Fractures/etiology , Femoral Fractures/diagnosis , Femoral Fractures/epidemiology
6.
J R Soc Interface ; 9(72): 1654-73, 2012 Jul 07.
Article in English | MEDLINE | ID: mdl-22279160

ABSTRACT

We model trabecular bone as a nanocomposite material with hierarchical structure and predict its elastic properties at different structural scales. The analysis involves a bottom-up multi-scale approach, starting with nanoscale (mineralized collagen fibril) and moving up the scales to sub-microscale (single lamella), microscale (single trabecula) and mesoscale (trabecular bone) levels. Continuum micromechanics methods, composite materials laminate theory and finite-element methods are used in the analysis. Good agreement is found between theoretical and experimental results.


Subject(s)
Elasticity/physiology , Epiphyses/physiology , Epiphyses/ultrastructure , Models, Biological , Tibia/physiology , Tibia/ultrastructure , Aged, 80 and over , Humans , Male
7.
J Pediatr Orthop ; 28(4): 435-9, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18520280

ABSTRACT

BACKGROUND: Legg-Calve-Perthes disease (LCPD) is a common hip disorder in children characterized by avascular necrosis of the proximal capital femoral epiphysis. The underlying etiology of the vascular disturbance is still unknown, but it is suggested that LCPD may be a part of a generalized constitutional disorder associated with growth disturbance of bone and cartilage tissue. In this study, the biopsy specimens of the iliac crest apophysis from LCPD patients were examined histologically and ultrastructurally to determine preexisting generalized abnormalities of endochondral ossification. METHODS: Iliac crest apophysis cartilage was taken during Salter innominate osteotomy from 11 children (8 boys and 3 girls) with LCPD at an average age of 7.8 years. As controls, the samples were also obtained from 10 children (2 boys and 8 girls) at an average age of 6.3 years undergoing Salter osteotomy due to residual acetabular dysplasia after reduction of developmental dysplasia of the hip. Each iliac crest apophysis specimen was examined histologically (Toluidine blue staining and Sudan III staining) and ultrastructurally. RESULTS: Although there were no obvious differences in Toluidine blue-stained sections of the iliac crest cartilage between LCPD and control patients, the Sudan III-positive chondrocytes in the resting cartilage were more prominent in the LCPD specimens than in the control specimens. These sudanophilic granules were confirmed to be lipid droplets by electron microscopic examinations. Ultrastructural examinations of the resting chondrocytes from 3 LCPD patients demonstrated numerous cytoplasmic inclusion bodies with electron dense materials, which were similar to those seen in some of the mucopolysaccharidoses. CONCLUSIONS: Increased lipid droplets and numerous cytoplasmic inclusions filled with fibrillar materials were suggestive of the initial metabolic changes of the chondrocytes, which may have a pivotal role in degenerating matrix and lead to vulnerability of the cartilage tissue. Our results indicated that generalized insufficiency in growth cartilage metabolism may be related to the onset of the disease in some LCPD patients.


Subject(s)
Cartilage/ultrastructure , Chondrocytes/ultrastructure , Epiphyses/ultrastructure , Ilium/ultrastructure , Legg-Calve-Perthes Disease/pathology , Child , Child, Preschool , Female , Humans , Legg-Calve-Perthes Disease/surgery , Male , Microscopy, Electron, Transmission , Osteotomy , Severity of Illness Index
8.
Cuad. med. forense ; 13(48/49): 143-156, abr.-jun. 2007. tab, graf
Article in Es | IBECS | ID: ibc-058408

ABSTRACT

Dentro de la estimación forense de la edad, las recomendaciones del AGFAD establecen la práctica de estudios de radiología de la clavícula para el diagnóstico de la edad en la franja entre los 18 y 21 años de edad. Se presenta un estudio sobre una muestra de 123 radiografías digitales de tórax de sujetos entre 5 y 75 años de edad en las que se ha analizado el estado de fusión de la epífisis esternal de la clavícula. En este estudio la edad mínima a la que se ha podido valorar la existencia de un estado de fusión completa (estadios 4 y 5 de Schmeling) ha sido de 19,7 años. Se analiza la bibliografía actualizada sobre este fenómeno y se apuntan una serie de sugerencias adicionales a las propuestas por AGFAD


In 2000 the AGFAD published their recommendations about forensic age estimations. They recommended an X ray of the clavicle (collar bone) in cases of subjects between 18 and 21 years of age. We present a study on stages of fusion of clavicle sternal epiphyses in a 123 digital X-rays from a population sample between 5 and 75 years of age. In our research minimum age at which complete fusion was achived (stages 4 or 5 in Schmeling method) has been 19,7 years of chronological age. A review of the medico legal literature about age estimation based on sternal end of the clavicle has been included. It´s pointed out that forensic experts should bear in mind some suggestions when applying AGFAD recommendations to obtain an age estimation based in clavicle X-rays


Subject(s)
Male , Female , Child , Adolescent , Adult , Middle Aged , Humans , Epiphyses/cytology , Epiphyses/ultrastructure , Clavicle/cytology , Clavicle/ultrastructure , Age Determination by Skeleton/methods , Radiography, Thoracic , Image Processing, Computer-Assisted/methods , Diagnostic Imaging/methods , Anatomy, Comparative/methods , Anatomy, Comparative/trends , Radiation/classification
10.
J Anat ; 208(6): 695-707, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16761972

ABSTRACT

Osteoblasts and osteocytes derive from the same precursors, and osteocytes are terminally differentiated osteoblasts. These two cell types are distinguishable by their morphology, localization and levels of expression of various bone cell-specific markers. In the present study on the chicken femur we investigated the properties of the mesenchymal cells within cartilage canals on their course into the secondary ossification centre (SOC). We examined several developmental stages after hatching by means of light microscopy, electron microscopy, immunohistochemistry and in situ hybridization. Cartilage canals appeared as extensions of the perichondrium into the developing distal epiphysis and they were arranged in a complex network. Within the epiphysis an SOC was formed and cartilage canals penetrated into it. In addition, they were successively incorporated into the SOC during its growth in the radial direction. Thus, the canals provided this centre with mesenchymal cells and vessels. It should be emphasized that regression of cartilage canals could never be observed in the growing bone. Outside the SOC the mesenchymal cells of the canals expressed type I collagen and periostin and thus these cells had the characteristics of preosteoblasts. Periostin was also expressed by numerous chondrocytes. Within the SOC the synthesis of periostin was down-regulated and the majority of osteoblasts were periostin negative. Furthermore, osteocytes did not secret this protein. Tissue-non-specific alkaline phosphatase (TNAP) staining was only detectable where matrix vesicles were present. These vesicles were found around the blind end of cartilage canals within the SOC where newly formed osteoid started to mineralize. The vesicles originated from osteoblasts as well as from late osteoblasts/preosteocytes and thus TNAP was only expressed by these cells. Our results provide evidence that the mesenchymal cells of cartilage canals express various bone cell-specific markers depending on their position. We suggest that these cells differentiate from preosteoblasts into osteocytes on their course into the SOC and consider that cartilage canals are essential for normal bone development within the epiphysis. Furthermore, we propose that the expression of periostin by preosteoblasts and several chondrocytes is required for adhesion of these cells to the extracellular matrix.


Subject(s)
Cartilage/ultrastructure , Epiphyses/ultrastructure , Femur/cytology , Osteogenesis , Stem Cells/cytology , Alkaline Phosphatase/analysis , Animals , Biomarkers/analysis , Cell Adhesion Molecules/analysis , Chickens , Chondrocytes/chemistry , Collagen Type I/analysis , Femur/ultrastructure , Immunohistochemistry/methods , In Situ Hybridization/methods , Mesoderm/cytology , Microscopy, Electron, Transmission , Osteoblasts/chemistry , Osteocytes/chemistry
11.
Georgian Med News ; (127): 61-4, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16308447

ABSTRACT

Experiments conducted by the authors, as well as clinical studies, show that in addition to hormonal mis-balance, development of mammary gland cancer is significantly influenced by the action of low frequency electromagnetic fields on epiphysis. By reducing the production of melatonin it increases the risk of development of mammary gland tumors. The review of scientific literature indicates that pinealocytes are the main morphological substrate responsible for functional activity of pineal cells. When estimating large specific weight of lipids, many researchers point to the dependence of their presence in epiphysis on the level of melatonin. It is thought that hormones of pineal cells are deposited in the form of lipid drops. The most characteristic feature in the structure of pinealocytes is the presence of large number of various size complexes in their bodies and appendices. According to many authors this could be the form of depositing the secretory products of pinealocytes, such as melatonin, biological amines, etc. Ultrastructure characteristic of pinealocytes described in the review provides deeper understanding of the fine structure morpho-physiology of epiphysis, enable to point out the peculiarities of its functionality under the influence of electromagnetic fields and discover the organizational structure of pineal body at a time of the mammary gland tumor development.


Subject(s)
Cell Transformation, Neoplastic/ultrastructure , Electromagnetic Fields , Epiphyses/radiation effects , Epiphyses/ultrastructure , Mammary Glands, Animal/ultrastructure , Mammary Neoplasms, Experimental/etiology , Animals , Rats
12.
Toxicology ; 216(2-3): 204-23, 2005 Dec 15.
Article in English | MEDLINE | ID: mdl-16182428

ABSTRACT

Cyclooxygenase (COX) inhibitors are the most commonly ingested drugs. The aim of the study was to evaluate the prenatal skeletal effect of selective (DFU) and nonselective (tolmetin, ibuprofen, piroxicam) COX-2 inhibitors. All the tested compounds were administered intragastrically to pregnant Wistar rats from 7 to 21 gestation day. The initial dose was set at 8.5mg/kg/dose for tolmetin and ibuprofen, 0.3 and 0.2mg/kg/dose for piroxicam and DFU. The middle dose was increased 10-times. The highest dose, except for ibuprofen, was elevated 100-times. The highest dose for ibuprofen was set at 200mg/kg/dose. Tolmetin and ibuprofen were administered three times a day. Piroxicam and DFU were dosed once daily. After routine teratological examinations, extremities of randomly selected 21-day-old fetuses were taken for histological, immunohistochemical and molecular studies. The proximal femoral epiphyses were separated and their ultrastructure evaluated. The expression of genes coding cytokines (IL-1alpha, IL-1beta, IL-6, TNF-alpha, TNF-beta) and proteins (COX-1, COX-2, cathepsin K, collagen types I, II and X; osteocalcin, osteopontin) was evaluated in femoral epiphyses by RNase Protection Assay and/or immunohistochemically. The articulate development was checked histologically and found undisturbed in any of the experimental groups. The epiphysis of the 21-day-old fetuses, presented physiological expression of COX-1 and COX-2, as well as cathepsin K, collagen types I, II and X; osteopontin, osteocalcin and TNF-alpha. Increased developmental skeletal variation was noted in groups exposed to the highest dose of nonselective drugs. Unlike the increased number of skeletal variations observed in fetuses exposed to highest doses of nonselective compounds, both groups of COX inhibitors did not disturb joint formation and morphology of femoral epiphyses when administered even in high maternal toxic doses.


Subject(s)
Bone Development/drug effects , Cyclooxygenase 2 Inhibitors/administration & dosage , Cyclooxygenase 2 Inhibitors/pharmacology , Fetal Development/drug effects , Organogenesis/drug effects , Animals , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Cathepsin K , Cathepsins/drug effects , Chondrocytes/drug effects , Collagen/drug effects , Drug Evaluation, Preclinical/methods , Epiphyses/drug effects , Epiphyses/ultrastructure , Female , Femur/drug effects , Femur/ultrastructure , Ibuprofen/pharmacology , Immunohistochemistry , Male , Osteocalcin/drug effects , Osteogenesis/drug effects , Osteopontin , Pregnancy , Rats , Rats, Wistar , Sialoglycoproteins/drug effects , Tolmetin/pharmacology , Tumor Necrosis Factor-alpha/drug effects
13.
N Z Vet J ; 53(2): 123-32, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15846396

ABSTRACT

AIM: To characterise and explain the increase in density evident by computerised tomography (CT) and radiography in companion studies as a response to training, in bone in the palmar and dorsal regions of the condyles of the third metacarpal bone (Mc3) of 2-year-old Thoroughbred horses. METHODS: Compositional back-scattered electron (BSE) imaging in scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM) were conducted on polymethyl methacrylate (PMMA)-embedded mediolateral slices of the right distal Mc3 from seven 2-year-old Thoroughbred horses trained on a racetrack and seven untrained horses kept at pasture. One left Mc3 from each group was studied in transverse section planes. This study focussed on regions of Mc3 found to differ in density between the trained and untrained horses in companion studies using CT and radiography. RESULTS: The increase of bone density in the condyles of Mc3 in trained horses compared with untrained horses occurred, without prior osteoclastic resorption, via the deposition of new bone on pre-existing internal surfaces. Within prior marrow spaces of cancellous bone, there was also rapid formation of immature strands and fronds of bone which were more cellular and mineralised, and more lamellar bone tissue was deposited on these new scaffolding elements in the trained horses. Both resulted in increased bone volume fraction (BVF). The microscopic mineralisation density of the bulk of the new tissue was lower than in pre-existing bone, and CT and radiography underestimated the increase in BVF. The new tissue was thus probably less stiff at the microscopic scale than pre-existing bone, though its addition would stiffen the global structure. CONCLUSIONS: In Mc3 of all the trained horses, there were obvious differences in microscopic structure compared with those from the untrained horses. Moderate, industry-standard levels of exercise used to prepare young horses for racing induced the formation of new bone in non-bone spaces in bone tissue, such that the bone organ should better withstand later increased levels of exercise.


Subject(s)
Bone Density/physiology , Epiphyses/anatomy & histology , Horses/anatomy & histology , Horses/physiology , Metacarpus/anatomy & histology , Physical Conditioning, Animal/physiology , Animals , Epiphyses/diagnostic imaging , Epiphyses/physiology , Epiphyses/ultrastructure , Female , Metacarpus/diagnostic imaging , Metacarpus/physiology , Metacarpus/ultrastructure , Microscopy, Confocal/veterinary , Microscopy, Electron, Scanning/veterinary , Microscopy, Fluorescence , Reference Values , Tomography, X-Ray Computed/veterinary
14.
Ann Diagn Pathol ; 8(2): 91-5, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15060887

ABSTRACT

Eosinophilic granulomas of long tubular bones, a form of Langerhans cell histiocytosis, occurs in metaphyses and diaphyses with equal frequency. Epiphyseal location is unusual, with only 13 cases previously reported in the literature. The present case involves the epiphysis of the upper end of the left femur in a 12-year-old boy with pain and limp in the affected area. Radiographic findings were an oval, radiolucent rarefaction with nonsclerotic border, measuring approximately 3.5 x 3.0 cm. Microscopic examination identified aggregates of histiocytes, multinucleated giant cells, scattered eosinophils, and few plasma cells and lymphocytes. Ultrastructural studies demonstrated Birbeck granules within cytoplasm of histiocytes diagnostic of Langerhans cell histiocytosis. Whether Langerhans cell histiocytosis is a neoplastic disorder or a reactive process remains controversial. The true nature of the Langerhans cell, the proliferating cells and hallmark of this disease, is likewise under scrutiny.


Subject(s)
Epiphyses/diagnostic imaging , Epiphyses/pathology , Femur/diagnostic imaging , Femur/pathology , Histiocytosis, Langerhans-Cell/diagnostic imaging , Histiocytosis, Langerhans-Cell/pathology , Child , Epiphyses/ultrastructure , Femur/ultrastructure , Humans , Male , Radiography
15.
J Bone Miner Res ; 19(5): 823-9, 2004 May.
Article in English | MEDLINE | ID: mdl-15068506

ABSTRACT

UNLABELLED: ERT decreases the severity of OA in OVX cynomolgus monkeys. We show that bone formation is greater in subchondral bone compared with epiphyseal/metaphyseal cancellous bone of the proximal tibia in these animals and that ERT decreases bone formation in both sites. ERT may decrease the risk of OA by decreasing bone formation in the SC bone. INTRODUCTION: Estrogen replacement therapy (ERT) decreases the risk of osteoporosis and osteoarthritis (OA) in postmenopausal women and has been shown to have direct effects on cells of the bone and cartilage. The effects of ERT have been studied extensively in cancellous bone, but subchondral (SC) bone directly beneath the articular cartilage has not been specifically evaluated. MATERIALS AND METHODS: Adult feral female cynomolgus monkeys were bilaterally ovariectomized (OVX) to simulate menopause; treated with ERT, soy phytoestrogens (SPE), or no hormones (OVX control group) for 3 years; and labeled with calcein before necropsy. At necropsy, the proximal tibias of 20 randomly selected animals from each treatment group were embedded in bioplastic and sectioned. Areas and labels were measured in a carefully defined region of the SC bone and epiphyseal/metaphyseal cancellous (EMC) bone, and derived dynamic and static indices were compared between the SC and EMC bone and among the three treatment groups. Student's t-tests and ANOVA were used to compare the data. RESULTS AND CONCLUSIONS: In both the SC and EMC bone, most of the values for the dynamic indices were highest in the OVX control group, intermediate in the SPE group, and lowest in the ERT group. The mineralizing surface, double-labeled surface, and bone formation rate (surface referent) were significantly higher in the SC bone compared with the EMC bone in the OVX control group. The trabecular bone volume was higher in the SPE-treated group compared with the OVX control group. In conclusion, the bone turnover indices were higher in the SC bone compared with the EMC bone, and ERT decreased these indices in both sites. In addition, SPE was protective against loss of bone volume.


Subject(s)
Bone Remodeling/drug effects , Epiphyses/metabolism , Estrogen Replacement Therapy , Tibia/anatomy & histology , Tibia/metabolism , Age Factors , Animals , Body Weight , Bone Remodeling/physiology , Calcification, Physiologic/drug effects , Calcification, Physiologic/physiology , Epiphyses/drug effects , Epiphyses/ultrastructure , Female , Macaca fascicularis , Ovariectomy , Random Allocation , Tibia/drug effects , Tibia/ultrastructure
16.
Calcif Tissue Int ; 70(4): 312-9, 2002 Apr.
Article in English | MEDLINE | ID: mdl-12004336

ABSTRACT

The blood supply of the growth plate has been described in the late 50s and early 60s, and there was controversial discussion about the existence of transphyseal vessels. The vascular supply of growth plate and epiphysis of the proximal tibia was reinvestigated using a modern technique, the Mercox-perfusion method, in six sheep aged 6-24 weeks. A comparison was made among pure perfusion specimens, the corrosion casts, and histological sections. The metaphyseal, epiphyseal, and perichondral blood supply systems were confirmed. However, there was evidence of regular transphyseal anastomoses between the metaphyseal and epiphyseal system. Based on the histological arrangement of the blood vessels, the arterial blood flow would appear to be from the metaphysis to the epiphysis. The existence of transphyseal arterial vessels originating metaphyseally and seen both in cast preparations and histological sections was added to the present description of the blood supply of the growth plate. Age-related differences in the vascularization of the growth plate were not found in this study.


Subject(s)
Epiphyses/blood supply , Growth Plate/blood supply , Animals , Epiphyses/growth & development , Epiphyses/ultrastructure , Female , Growth Plate/growth & development , Growth Plate/ultrastructure , Male , Microscopy, Electron, Scanning/methods , Sheep
17.
J Orthop Res ; 17(2): 214-22, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10221838

ABSTRACT

Slipped capital femoral epiphysis involves the gradual displacement of the femoral head relative to the neck. Many theories have arisen to explain this slip. Frequently cited etiological factors include increases in physeal thickness and inclination. Slipped epiphysis has been postulated to result from shear overload that causes separation through the hypertrophic cellular zone. We sought to answer the following questions: (a) Do significant regional differences in strength and stiffness exist within a given physis? (b) Are regional differences in resistance to shear related to thickness and inclination of the physis? (c) Does physeal compression cause mammillary interdigitation to begin sooner and increase the resistance to shear before, during, and after failure? (d) Does shear failure occur at displacements detectable by radiography? and (e) Does cleavage occur throughout the entire columnar zone, and do the chondrocyte columns remain intact on both sides of the cleavage plane? We prepared beam-shaped microstructural samples from different sites of the bovine proximal tibial physis. We determined thickness, inclination, ultimate stress and strain, modulus, and strain energy density at ultimate stress as a function of location. Using scanning electron microscopy, we also examined the entire failed surface of several samples. Forty-eight samples were tested by displacing the epiphysis end anteriorly, without axial (across the thickness) constraint; 41 were sheared while an average axial compressive stress of 0.3 MPa was applied to the physis. The posterior region had the greatest strength and stiffness, lowest physeal thickness, and steepest inclination. Compressing the plate did not increase the shear strength or tangent modulus. Ultimate strength varied inversely with thickness and increased when shearing up steeper inclinations; however, it was more strongly associated with the modulus, implying that additional factors control both strength and modulus. Scanning electron microscopy revealed that the plane of fracture differed widely between and within samples, involving all zones of the growth plate. On either side of the fracture, individual chondrocyte columns remained intact, although separated from neighboring columns.


Subject(s)
Epiphyses/physiology , Tibia/physiology , Animals , Cattle , Elasticity , Epiphyses/ultrastructure , Female , Growth Plate/anatomy & histology , Growth Plate/diagnostic imaging , Knee Joint/anatomy & histology , Microscopy, Electron, Scanning , Models, Biological , Radiography , Stress, Mechanical , Tibia/anatomy & histology , Tibia/diagnostic imaging , Weight-Bearing/physiology
18.
J Bone Miner Res ; 13(6): 950-61, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9626626

ABSTRACT

Many events occur concurrently during the initiation of the secondary ossification center in the cartilaginous epiphyses of long bones. We have investigated the chronology of interactions between the vascular system and epiphyseal chondrocytes by culturing explanted heads of femurs and humeri from pre- and neonatal rabbits on the chorioallantoic membrane (CAM) of growing chick embryos. We confirmed that, on the whole, the epiphyseal cartilage was resistant to vascular invasion, whereas the physeal growth plate was resorbed. However, new CAM-derived cartilage canals occasionally penetrated through the articular surface. This caused death of those chondrocytes in the immediate vicinity of the canal but no further reaction. If explants already contained a bony epiphysis and were halved prior to culture, CAM-derived vessels were attracted to the spongiosa. From there they pushed into the uncalcified cartilage, indicating that calcification was not a prerequisite for vascular invasion. Where at least two vessels were in apposition, a new pseudo-ossification center was initiated: chondrocytes became hypertrophic and the matrix calcified. This suggests that cumulative release of diffusible factors from more than one vessel was the trigger for chondrocyte hypertrophy, which, in turn, led to the initiation of the bony epiphysis. CAM cultures thus provide an experimental model for both the quiescent angiogenesis of cartilage canal formation and the reactionary angiogenesis associated with chondrocyte hypertrophy. By exploiting the different anatomy of CAM-derived vascularity, events that occur concurrently in vivo can be specially separated in CAM culture.


Subject(s)
Chondrocytes/physiology , Epiphyses/embryology , Femur Head/embryology , Humerus/embryology , Neovascularization, Physiologic/physiology , Allantoin , Animals , Apoptosis/physiology , Cartilage, Articular/blood supply , Cartilage, Articular/embryology , Cells, Cultured , Chorionic Villi/blood supply , Epiphyses/ultrastructure , Femur Head/blood supply , Humerus/blood supply , Rabbits
19.
J Orthop Res ; 14(5): 810-7, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8893776

ABSTRACT

Three types of elastic fibers have been described: mature elastic fibers, elaunin fibers, and oxytalan fibers. To our knowledge, their location in the immature epiphysis has never been previously reported. The aim of the present study was to use histochemistry, immunohistochemistry, and electron microscopy to demonstrate the distribution of each type of elastic fiber in the epiphyseal region of growing humans and rabbits. Histological samples were collected from the knees of 10 immature New Zealand White rabbits and four children of various ages. The Weigert resorcin-fuchsin, Gomori aldehyde-fuchsin, Verhoeff iron haematoxylin, and Fullmer-Lillie methods were used for histochemistry; anti-elastin monoclonal antibodies, for immunohistochemistry; and tannic acid, uranyl acetate, and lead citrate stain, for transmission electron microscopy analysis. Elastic fibers were detected in the perichondrium, the epiphyseal vessels, and the outer and middle zones of Ranvier's groove. Their orientation was longitudinal in the outer zone and circumferential in the middle zone of the groove. Oxytalan fibrils (i.e., bundles of filaments of 10-12 nm in diameter that do not contain elastin) and elaunin fibers (i.e., filaments that cross discontinuous aggregates of elastin) were more plentiful in the middle zone and decreased with age, whereas mature fibers were more numerous in the outer zone and increased with age. This organization of elastic fibers seems to indicate an age-related process of maturation of the elastic network. The contribution of these fibers to the mechanical properties of the epiphyseal plate and to the growth process remains to be determined.


Subject(s)
Elastic Tissue/growth & development , Femur/chemistry , Femur/growth & development , Age Factors , Animals , Animals, Newborn , Cartilage/chemistry , Cartilage/growth & development , Cartilage/ultrastructure , Child , Child, Preschool , Contractile Proteins/analysis , Elastic Tissue/chemistry , Elastic Tissue/ultrastructure , Elastin/analysis , Epiphyses/chemistry , Epiphyses/growth & development , Epiphyses/ultrastructure , Femur/ultrastructure , Histocytochemistry , Humans , Immunohistochemistry , Infant , Infant, Newborn , Microscopy, Electron , Rabbits
20.
Bone ; 18(1): 29-39, 1996 Jan.
Article in English | MEDLINE | ID: mdl-8717534

ABSTRACT

We performed immunohistochemical and ultrastructural studies to disclose a possible relationship between nerve fibers and bone metabolism. Immunohistochemical distribution of calcitonin gene-related peptide (CGRP)-positive nerve fibers during bone development was assessed in the femurs of rats. CGRP-positive nerve fibers were denser in the epiphysis than in the metaphysis. These nerve fibers particularly ran along the epiphyseal trabecules facing the growth plate and came in contact with osteoclasts. Many osteoclasts at the epiphyseal trabecules facing the growth plate contained abundant toluidine blue and periodic acid-Schiff-positive granules. Electron microscopy revealed that these osteoclasts have many membrane-bound, electron-dense granular structures and dilated cisterns of rough endoplasmic reticulum containing electron-dense material. They were often surrounded by clear cells displaying features of nerve fiber and had no ruffled border. Furthermore, ultrastructural observations revealed electron-dense structures coating the cytoplasmic side of plasma membranes of the nerve fibers. We also observed coated pits in the cytoplasm of the osteoclasts facing the nerve fibers. To further clarify the role of innervation, we compared trabecules of rats undergoing denervation of the sciatic nerve with those from unoperated rats. Denervation resulted in a significant increase in the number of cement lines on the epiphyseal trabecules facing the growth plate. These results suggest that the osteoclasts at the epiphyseal trabecules facing the growth plate are in part regulated by CGRP-positive nerve fibers. Thus, CGRP-positive nerve fibers could be a crucial element in bone metabolism during bone growth and development.


Subject(s)
Bone Development/physiology , Bone and Bones/metabolism , Calcitonin Gene-Related Peptide/analysis , Epiphyses/growth & development , Growth Plate/ultrastructure , Nerve Fibers/chemistry , Animals , Bone and Bones/innervation , Denervation , Embryonic and Fetal Development/physiology , Epiphyses/ultrastructure , Femur/innervation , Femur/metabolism , Hindlimb/innervation , Immunohistochemistry , Nerve Fibers/ultrastructure , Osteoclasts/ultrastructure , Rats , Rats, Wistar , Sciatic Nerve/physiology
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