Isoflavones and calcified tissues

The data about osteotropic action of isoflavones are presented in this review. Isoflavones are the compounds of phytoestrogenes group--hormone-like bioregulators of plant origin. Animal experiments as well as bone tissue and bone cells cultures investigations demonstrate anabolic effect of isoflavones on bone metabolism. Isoflavones prevent bone loss in ovariectomized animals. They inhibit bone resorbition and enhance bone formation. Because of this natural and synthetic isoflavones hold great promise in the prevention and treatment of osteoporosis. These compounds may also be effective in preventing bone loss associated with hypodynamia or immobility, ovariectomy or postmenopausal hypoestrogenia, chronic corticosteroid use, renal osteodystrophy, hyperparathyroidism and other metabolic disorders affecting the calcified tissues, including alveolar bone loss in periodontal disease as well as dental hard tissues destruction.     

Temporal bone CT in the diagnosis of acquired diseases of the external auditory canal

CT was used to examine 50 patients (100 temporal bones) aged 10 days to 60 years who had no signs of lesion of the external auditory canal (EAC) and 23 patients (27 temporal bones) aged 13 to 65 years who had clinical manifestations of acquired stenosis or obturation of the EAC. Polypositional CT of the temporal bone is the most informative technique of visualization of the osseous part of the EAC, at the same time the anterior and posterior EAC walls were evaluated in the axial projection and the upper and lower EAC walls were assessed in the coronary projection. According to CT data, formation of the osseous part of the EAC occurs within the first 7 years of a child's life. In the presence of EAC changes, CT may assess their pattern (a soft tissue or osseous one), their magnitude and location along the walls of the canal, the tympanic membrane, and other structures of the temporal bone. CT reveals the causes of acquired EAC obturation, stenosis, and atresia: osteocartilaginous exostoses, osteomas, polyps of the EAC, tumors of the temporal bone, as well as obturative keratosis and posttraumatic stenosis of the EAC. The detected EAC changes determine further management policy in a patient.     

Molecular evidence for different stages of tuberculosis in ancient bone samples from Hungary

This paleomicrobiologic study was conducted on osseous tissue specimens from ancient Hungarian skeletal samples from the 7-8th and the 17th centuries AD with typical macromorphologic evidence of osseous tuberculosis (n = 3), morphologic alterations probably due to tuberculosis (n = 6), or with nontypical osseous changes of vertebral bodies suggestive of inflammatory reaction (n = 5). From these bone samples, DNA was extracted and amplified by polymerase chain reaction (PCR) by using various primer pairs recognizing DNA segments of different mycobacterial species. To confirm specificity of the analysis, the amplification products of several samples were subjected to restriction enzyme digestion and/or direct sequencing. Of the analyzed 14 cases, 8 were unambiguously positive for mycobacterial DNA of the Mycobacterium tuberculosis complex, as shown by the amplification of the IS6110 sequence. In 13 cases we found a PCR product with primers specific for the 65-kDa antigen gene, including 2 cases without genomic DNA. We conclude that the application of other mycobacterial DNA primers may reveal contamination of bones with atypical saprophytic mycobacteria. A positive result for typical mycobacteria was seen in 2 of 3 cases with typical morphologic signs of tuberculosis and amplifiable DNA, in 3 of 6 probable cases, but also in 3 of 6 cases with nontypical bone changes. This indicates that minor osseous reactions of the surface of vertebral bodies may be due-at least in several cases-to infections with bacteria of the M. tuberculosis complex. In these cases the disease may have proceeded rapidly, and the morphologic osseous changes may represent "early" stages of tuberculous infection of the vertebrae.     

Ultramicroscopic features of bone marrow cells in response to exposure to staphylococcal toxin during hypoxia

In rats, already on the first day of the experiment, certain signs of destruction are observed in the bone marrow cells. They are demonstrated as an intensive vacuolization of cytoplasm, its lipid infiltration, as well as presence in vacuoles the material with middle and high electron density. In cells of the erythroid line not any essential ultrastructural changes are observed. By the end of the experiment (30 days), the destructive changes are noted not in all the cells and not in all hemopoietic lines. This is evidently depended on adaptation of the organism.     

Metabolic responses of the body to breathing with hypoxic argon–oxygen and nitrogen–oxygen mixtures

We have studied metabolic responses of six male volunteers who were exposed to hypoxic nitrogen–oxygen and argon–oxygen respiratory mixtures under hermetic chamber conditions for a long time. We measured the values of 44 biochemical parameters of venous blood, which reflected the state of different parts of metabolism, as well as the state of organs and tissues. Under the conditions of argon–oxygen respiratory mixture with the level of oxygen of 12.8% within the first five days and 12.0% from six to ten days of the experiment, the activation of processes of anaerobic glycolysis and lipolysis with the development of metabolic acidosis was observed. Against this background, biochemical signs of unfavorable changes in the myocardium were recorded. When we used the nitrogen–oxygen respiratory mixture with the level of oxygen of 13.0% during the first five days of the experiment and 12.1% from the sixth to the tenth day, these changes were expressed much more significantly: the activation of lipolysis and a decrease in the level of serum iron were observed and the signs of damage of mitochondria, depression of the kidney function, and development of hypodynamia were recorded. Complete stabilization of metabolic processes was reached only after seven to eight days of the recovery period for both mixtures. These findings lead to the conclusion that it is physiologically more preferable to use oxygen–argon respiratory mixtures at small immersion depths.     

Stromal cells of the bone marrow in growing bone

By means of electron microscopy, cytochemistry and radioautography with 3H-thymidine, the bone marrow stromal cells have been studied in the zones of endochondral osteogenesis in the rabbit and rat femoral bones. In the stromal cells demonstrating a high alkaline phosphatase activity are distinguished: perivascular, reticular fibroblastic, osteogenic cells. Populations of the perivascular phosphatase-positive cells include poorly differentiated DNA-synthesizing forms, as well as cells with signs of differentiation into stromal fibroblasts. Cleft-like spaces in cytoplasm of the fibroblastic reticular cells are, probably, formed as a result of lymphocyte-like mononuclears passing through. Phagocyting stromal elements are presented by macrophages, having perivascular localization and including into composition of erythroblastic islets. Mononuclear macrophages are revealed also on the surface of osseous trabecules, where they participate in destruction of hemopoetic and osteogenic cells.     

Chondroid bone arises from mesenchymal stem cells in organ culture of mandibular condyles

Mandibular condyles of fetal mice 19 to 20 days in utero comprising clean cartilage and its perichondrium were cultured for up to 14 days, and their capacity to develop osteoid and to mineralize in vitro was examined. After 3 days in culture the cartilage of the mandibular condyle appeared to have lost its inherent structural characteristics, including its various cell layers: chondroprogenitor, chondroblastic, and hypertrophic cells. At that time interval no chondroblasts could be seen; instead, most of the cartilage consisted of hypertrophic chondrocytes. By that time, the surrounding perichondrium, which contains pluripotential mesenchymal stem cells, revealed the first signs of extracellular matrix enclosing type I collagen, bone alkaline phosphatase, osteonection, fibronectin, and bone sialoprotein as demonstrated by immunofluorescent techniques. Electron microscopic examinations of the newly formed matrix revealed foci of mineralization within and along collagen fibers as is normally observed during bone development. The composition of the latter mineral deposits resembled calcium pyrophosphate crystals. Following 14 days in culture larger portions of the condyle revealed signs of osseous matrix, yet the tissue reacted positively for type II collagen. Hence, the condylar cartilage, a genuine representative of secondary-type cartilage, elaborated in vitro a unique type of bone that would be most appropriately defined as chondroid bone. Biochemical assays indicated that the de novo formation of chondroid bone was correlated with changes in alkaline phosphatase activity and 45Ca incorporation. The findings of the present study imply that mesenchymal stem cells that ordinarily differentiate into cartilage possess the capacity to differentiate into osteogenic cells and form chondroid bone.     

Condition of the endothelium of the aorta during hypodynamia

The state of the aortic internal lining under conditions of hypodynamia has been studied on 47 white male rats morphometrically and stereologically in film preparations of endothelium. The results of measurements have been treated by means of the moving average method. Significance of differences has been estimated using nonparametric criterion of Wilcoxon--Mann--Whitney. For objective periodization of reactions centring of approximated curves with successive calculation of the variation coefficient of the centered ordinates in every time point has been calculated. Hypokinesia produces manifested changes of phasic character in endothelium. Restoration of the disturbed homeostasis in endothelium is ensured on the bases of both intracellular and cellular regeneration. At late stages (beginning from the 20th day) density in arrangement of endotheliocytes in the layer decreases, as well as the degree of tissue regularity. Polymorphism of endothelium is essentially manifested. Parameters demonstrating destruction and death of cells are rather high. Under such conditions, the response reaction of the arterial wall could acquire the character of developing atherosclerotic lesion.     

Dynamics of the glycemic profile in women in long-term antiorthostatic hypokinesia

The dynamics of the glycemic curve profile was investigated in 8 healthy women during performance of the glucose tolerance test (GТТ) in 120-day antiorthostatic hypokinesia (–6°) (АNОH) simulating the effects of weightlessness. Glycemic profiles were characterized by more marked hyperglycemic response at 30 min of GТТ in the first month of stay under ANOH conditions and had a flattened appearance three months later. Glycemic profiles characteristic of delayed restoration of the blood glucose concentration appeared in the fourth month, which persisted over the first week after the end of АNОH. The glycemic profile changes developed against the background of the signs of progressive congestion of blood in the venous system of the abdominal cavity. The expansion of diameters of the main veins of the abdominal cavity was noted at the beginning of АNОH; an increase in the size of the organs and the signs of expansion of venous plexuses at the site of portocaval anastomoses, after three months; the occurrence of the signs of transudation and free fluid in the abdominal cavity was revealed at the end of hypokinesia. The countermeasures against hypodynamia did not prevent transformation of the glycemic profile nor did they influence the progression of blood flow congestion in the venous system of the abdominal cavity whose features determined the character changes in the glycemic profile in different periods of ANOH.     

Effect of long-term simulated microgravity on some sexual traits of male Japanese quail

The aim of this study was to investigate the effects of long-term stay of Japanese quail in simulated microgravity on some sexual features of males. As a model for simulating microgravity exposure of birds in laboratory conditions was used hypodynamia. The mean left testis weight in males reared under hypodynamia from day 3 up to 180 days of age was lower than that of control (P<0.05), but the right testis weight differences between both groups were not significant. Also the area, volume and foam production of cloacal gland was not significantly decreased in hypodynamia birds at the end of experiment. By contrast, the plasma testosterone concentration of males living in hypodynamia was reduced about 50 % at 90 and 180 days of age in comparison to control (P<0.05) suggesting some negative effects on sexual development. Our results demonstrated that male quail kept under simulated microgravity conditions were sexually competent although their sexual efficiency was reduced especially in terms of plasma testosterone.     

Designing biological models of hysteresis live systems of osseous tissue and periosteum

Biological models of osseous tissue and periosteum have been developed. Biocompatible materials of titaniumnickel as an integral part of implant-tissue composites have been already functioning for five years, substituting for damaged bone fragments. The defects of skeletal kinematic sections of the mandible of experimental animals were replaced by biomechanical models of implant-tissue composites of the osseous tissue and periosteum. The composites were formed by joining the models of extracellular matrixes of osseous tissue and periosteum and the natural tissues. The validity of methodological propositions and optimal technological solutions have been proved by the absence of life-time signs of biochemical, biomechanical, hysteresis or thermodynamic incompatibility on tissue and skeletal levels.     

Bone grafts,bone substitutes and orthobiologics

The biology of fracture healing is better understood than ever before, with advancements such as the locking screw leading to more predictable and less eventful osseous healing. However, at times one’s intrinsic biological response, and even concurrent surgical stabilization, is inadequate. In hopes of facilitating osseous union, bone grafts, bone substitutes and orthobiologics are being relied on more than ever before. The osteoinductive, osteoconductive and osteogenic properties of these substrates have been elucidated in the basic science literature and validated in clinical orthopaedic practice. Furthermore, an industry built around these items is more successful and in demand than ever before. This review provides a comprehensive overview of the basic science, clinical utility and economics of bone grafts, bone substitutes and orthobiologics.     

Bone grafts,bone substitutes and orthobiologics: The bridge between basic science and clinical advancements in fracture healing

The biology of fracture healing is better understood than ever before, with advancements such as the locking screw leading to more predictable and less eventful osseous healing. However, at times one’s intrinsic biological response, and even concurrent surgical stabilization, is inadequate. In hopes of facilitating osseous union, bone grafts, bone substitutes and orthobiologics are being relied on more than ever before. The osteoinductive, osteoconductive and osteogenic properties of these substrates have been elucidated in the basic science literature and validated in clinical orthopaedic practice. Furthermore, an industry built around these items is more successful and in demand than ever before. This review provides a comprehensive overview of the basic science, clinical utility and economics of bone grafts, bone substitutes and orthobiologics.     

Effect of infrared impulse laser irradiation on the development of albino rat embryos]

Development of the white rat embryos has been studied under effect of infrared laser beams (wave length--0.89 mcm, impulse frequency--300 Hz) during various periods of pregnancy. Exposure of the female rats for 256 and 128 sec produces an increased preimplantational death of embryos and certain disturbances in formation of the osseous skeleton in some embryos.     

Mechanical characterization of regenerated osseous tissue during callotasis and its related biological phenomenon

The mechanical characteristics of the regenerated osseous tissue and osteoblastic activities during callotasis were studied using Chinese mountain goat as the animal model. Open osteotomy of the left tibiae was done in 24 goats. Distraction started 6 days after the operation with the rate of 1 mm per day for 4 weeks. The bone regeneration was monitored with serial X-ray films. The tension generated during distraction was measured with the strain gauges mounted on the distraction apparatus. The osteoblastic activities were monitored by measuring plasma bone specific alkaline phosphatase activity. The results showed that the average lengthening was 22.9 +/- 2.8 mm in each animal. The newly formed osseous tissue becomes stiffer during the course of distraction lengthening. The continuous evolution of the tensile behaviour of the newly formed osseous tissue correlates with the plasma bone specific alkaline phosphatase activities. The radiological appearance of a physis like structure took place at 12 mm lengthening. Its appearance corresponds to the changes in the tensile behaviour as well as the biological activities of the osteoblasts and may serve as a useful radiological marker in monitoring the process of callotasis in clinical practice.     

Bone Mass and Bone Quality Are Altered by Hypoactivity in the Chicken

Disuse induces a rapid bone loss in adults; sedentarity is now recognized as a risk factor for osteoporosis. Hypoactivity or confinement also decrease bone mass in adults but their effects are largely unknown and only few animal models have been described. We have used 10 chickens of the rapidly growing strain 857K bred in a large enclosure (FREE group); 10 others were confined in small cages with little space to move around (HYPO group). They were sacrificed at 53 days and femurs and tibias were evaluated by texture analysis, dual energy X-ray densitometry, microcomputed tomography (microCT) and histomorphometry. Hypoactivity had no effect on the length and diameter of the bones. Bone mineral density (BMD), microCT (trabecular bone volume and trabecular microarchitecture) and texture analysis were always found significantly reduced in the animals of the HYPO group. BMD was reduced at both femur and tibia diaphysises; BMD of the metaphysis was significantly reduced in the femur but not in the tibia. An increase in osteoid volume and surfaces was noted in the HYPO group. However, there was no alteration of the mineral phase as the osteoid thickness did not differ from control animals. Bone loss was much more pronounced at the lower femur metaphysis than at the upper metaphysis of the tibia. At the tibia, only microarchitectural changes of trabecular bone could be evidenced. The confined chicken represents a new method for the study of hypodynamia since these animals do not have surgical lesions.     

Comparative characteristics of radiation imaging methods in the diagnosis of sacroiliitis

Patients with sacroiliac joint, injuries, ankylosing spondyloarthritis, or spondyloarthropathy of various genesis were examined. Pelvis x-ray, spiral computed tomography (CT), and magnetic resonance imaging (MRI) were performed. MRI was found to have advantages in the detection and evaluation of the pattern of detectable bone changes. It is inexpedient to use traditional x-ray study and CT for the detection of edematous-infiltrative changes in both osseous and fibrous and soft tissue elements of the joint since the sensitivity of these techniques is insufficient to detect. To analyze detectable changes, it is expedient to use a unified MRI protocol that involves the characteristics of osseous, fibrous, and soft tissue structures of the joint.     

Effects of selective iNOS inhibition on type II collagen-induced arthritis in mice

Nitric oxide as well as prostaglandins has been reported to play an important role in inflammatory diseases including arthritis. In the present study, the effects of iNOS inhibition on development of disease were examined in type II collagen-induced arthritis (CIA) in male DBA/1J mice. From 4 weeks after the first immunization with bovine type II collagen, 1400W (10 mg/kg/day, p.o.), a selective iNOS inhibitor, indomethacin (1 mg/kg/day, p.o.), a cyclooxygenase (COX) inhibitor, or 1400W + indomethacin was administered for 8 weeks. Immunization with type II collagen evoked arthritic inflammation of paws and bone destruction accompanied by increases in urinary nitrite/nitrate (NOx) excretion, plasma NOx and PGE2 levels. Administration of 1400W reduced urinary NOx excretion and increased plasma PGE2 levels, while it had no effect on arthritic inflammation or bone destruction. Indomethacin slightly reduced the inflammatory signs and bone destruction with marked reduction of plasma PGE2. Combination of 1400W and indomethacin reduced urinary NOx and PGE2 levels, and showed greater amelioration of inflammatory signs and bone destruction than either alone. In conclusion, 1400W, a selective iNOS inhibitor, failed to prevent CIA probably due to its increasing effect on PGE2 production, but showed a synergistic ameliorative effect in combination with indomethacin.     

Influence of physical exercise after long-lasting hypodynamia on the morphological parameters of muscle fibers

The purpose of this research was morphometric ultrastructure evaluation of the fibers in muscles taking part in the flight of pigeons forced to exercise after a long period of hypodynamia. It was found that following physical exercise, after 12 and 18 months of mobility limitation, there appeared marked qualitative and quantitative changes: a diminution of the volume fraction and number of mitochondria, increase of smooth sarcoplasmic reticulum and sarcoplasm, and a significant decrease of the number of glycogen granules as compared with those after 18 months hypodynamia. The above described changes were more pronounced in the supracoracoideus than in the pectoralis muscle.