[Morphological structure of rat epiphysis exposed to electromagnetic radiation from communication devices].

Pineal gland is one of the most important components of homeostasis - the supporting system of the body. It participates in the launch of stress responses, restriction of their development, prevention of adverse effects on the body. There was proved an impact of electromagnetic radiation on the epiphysis. However, morphological changes in the epiphysis under exposure to electromagnetic radiation of modern communication devices are studied not sufficiently. For the time present the population is daily exposed to electromagnetic radiation, including local irradiation on the brain. These date determined the task of this research - the study of the structure of rat pineal gland under the exposure to electromagnetic radiation from personal computers and mobile phones. These date determined the task of this research - the study of the structure of rat pineal gland under the exposure to electromagnetic radiation from personal computers and mobile phones. Performed transmission electron microscopy revealed signs of degeneration of dark and light pinealocytes. These signs were manifested in the development of a complex of general and specific morphological changes. There was revealed the appearance of signs of aging and depletion transmission electron microscopy both in light and dark pinealocytes. These signs were manifested in the accumulation of lipofuscin granules and electron-dense "brain sand", the disappearance of nucleoli, cytoplasm vacuolization and mitochondrial cristae enlightenment.

Low level irradiation in mice can lead to enhanced trabecular bone morphology.

Charged particle radiation such as iron ions and their secondary fragmentation products are of particular concern to the skeleton due to their high charge and energy deposition. However, little is known about the long-term effects of these particles on trabecular and cortical bone morphology when applied at relatively low levels. We hypothesized that even a 4.4 cGy dose of a complex secondary iron ion radiation field will compromise skeletal quantity and architecture in adult mice. One year after radiation exposure and compared to age-matched controls, 4.4 cGy irradiated mice had 51 % more trabecular bone, 56 % greater trabecular bone volume fraction, 16 % greater trabecular number, and 17 % less trabecular separation in the distal metaphysis of the femur. Similar to the metaphysis, trabecular bone of the distal femoral epiphysis in 4.4 cGy mice had 33 % more trabecular bone, 31 % greater trabecular bone volume fraction, and a 33 % smaller structural model index. Cortical bone morphology, whole bone mechanical properties, and lower leg muscle mass were unaffected. When compared to two additional groups, irradiated at either 8.9 or 17.8 cGy, a (negative) dose response relationship was observed for trabecular bone in the metaphysis but not in the epiphysis. In contrast to our original hypothesis, these data indicated that a secondary field of low-level, high-linear energy transfer iron radiation may cause long-term augmentation, rather than deterioration, of trabecular bone in the femoral metaphysis and epiphysis of mice.

The effects of low-level laser therapy, 670 nm, on epiphyseal growth in rats.

The longitudinal growth of long bones is attributed to epiphyseal growth. However, the effects of low-level laser therapy (LLLT) in such structures has still not been studied extensively in the literature. Therefore, the aim of this study was to evaluate the use of LLLT, 670 nm, at three different doses on the epiphyseal growth of the right tibia of rats. Twenty-one Wistar rats, aged four weeks, were subjected to the application of LLLT, with dosage according to the group (G4: were submitted to the application of 4 J/cm(2); G8: were submitted to the application of 8 J/cm(2); G16: were submitted to the application of 16 J/cm(2)). After completion of protocol they were kept until they were 14 weeks of age and then submitted to a radiological examination (evaluation of limb length) and euthanised. The histological analysis of the growth plates (total thickness and hypertrophic and proliferative zones) was then performed. Comparisons were made with the untreated left tibia. No differences were observed in any of the reviews (radiological and histological), when comparing the right sides (treated) to the left (untreated). It was concluded that the treatment with LLLT within the parameters used caused changes neither in areas of the epiphyseal cartilage nor in the final length of limbs.

[Formation of ossification nucleus in the femoral head in hamsters exposed to laser radiation].

The purpose of the study was to detect the relation between the formation of ossification nucleus in the epiphysis and the ingrowth of vessels into it, using laser radiation of femoral heads. The study was performed in 30 golden hamsters, 20 of them starting at 10 days after birth were exposed to daily irradiation of the right hip joint (during 3-80 days). The left joint was used as control. The radiation was performed with Agnis laser device (radiation power--2 mW, impulse frequency--2500 Hz, exposure duration--8 min, optical fiber diameter--4 mm). Femoral bones of experimental and control animals were histologically studied at days 13 till 90. Laser radiation was found could delay vessel growth from diaphysis into epiphysis for up to 13 days, and the beginning of ossification nucleus formation in the femoral head--for up to 5 days. This suggests the direct relation of the development of bone ossification nucleus in the epiphysis and growing of vessels into its cartilage, since no other factors retarding the vessel growth and formation of bone nucleus were used.

Ultrastructural organization of epiphysis in rats under the action of electromagnetic fields and during mammary carcinogenesi.

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.

The effects of therapeutic vs. high-intensity ultrasound on the rabbit growth plate.

Six of 6-week-old NZ rabbits underwent ultrasound treatment using a therapeutic dose (0.5 W/cm(2)) and other six were treated with a higher dose (2.2 W/cm(2)) to the lateral aspect of the left knee joint for 20 min per day and a total of six weeks. The right knee joint served as a control. The goal of this study is to see if the therapeutic dose and high dose (approximately 45-fold therapeutic dose) will have toxic effects on the physis. Histological review appeared normal growth plate in the therapeutic group. In the high dosage group three of six cases displayed flattening of the distal femoral epiphysis and wedging of the proximal tibial plateau and indistinct growth plate lines. It is of interest to note that there are opening radiolucent area in the lateral aspect on the femoral metaphysis in five of six cases, where bone resorption has taken place. Histological results showed that there are disordered arrays of the cartilaginous cells in the proliferative zone. The height of the lateral physis in the high dose group is not only greater than that in the therapeutic dose (1083.8 vs. 500.3 micro m), but also greater than that in their contralateral control (530.7 micro m) (P<0.05). This short-term study demonstrates that high dose ultrasound has profound pathologic effects in growing bone. Therapeutic doses of ultrasound do not have an adverse effect on bone growth in the short-term follow-up.

Site-specific variability in trabecular bone dosimetry: considerations of energy loss to cortical bone.

With continual advances in radionuclide therapies, increasing emphasis is being placed on improving the patient specificity of dose estimates to marrow tissues. While much work has been focused on determining patient-specific assessments of radionuclide uptake in the skeleton, few studies have been initiated to explore the individual variability of absorbed fraction data for electron and beta-particle sources in various skeletal sites. The most recent values of radionuclide S values used in clinical medicine continue to utilize a formalism in which electrons are transported under a trabecular bone geometry of infinite extent. No provisions are thus made for the fraction of energy lost to the cortical bone cortex of the skeletal site and its surrounding tissues. In the present study, NMR microscopy was performed on trabecular bone samples taken from the femoral head and humeral proximal epiphysis of three subjects: a 51-year male, an 82-year female, and an 86-year female. Following image segmentation and coupling to EGS4, electrons were transported within macrostructural models of the various skeletal sites that explicitly include the spatial extent of the spongiosa, as well as the thickness of the surrounding cortical bone. These energy-dependent profiles of absorbed fractions to marrow tissues were then compared to transport simulations made within an infinite region of spongiosa. Ratios of mean absorbed fraction, as weighted by the beta energy spectra, under both transport methodologies were then assembled for the radionuclides 32P and 90Y. These ratios indicate that corrections to existing radionuclide S values for 32P can vary by as much as 5% for the male, 6% for the 82-year female, and 8% for the 86-year female. For the higher-energy beta spectrum of 90Y, these same corrections can reach 8%, 10%, and 11%, respectively.

Long-term changes in the haversian systems following high-dose irradiation. An ultrastructural and quantitative histomorphological study.

The effects of high-dose irradiation on the morphology of haversian bone were studied, over a fifty-two-week period, in seventy-seven adult rabbits, after the administration of a single dose of radiation (therapeutic x-ray; twenty-five, fifty, or 100 gray) to one knee joint. The specimens of bone were examined with microangiography, light and transmission electron microscopy, and histomorphometry. Analysis was performed on the haversian bone in the subchondral bone plate of weight-bearing portions of the femoral condyles. Microangiography demonstrated dilatation of the microvasculature four weeks after irradiation. Beginning at twelve weeks, there was a marked decrease in vascularity; no obvious recovery of the subchondral bone had occurred by fifty-two weeks. At four weeks, morphological analysis revealed two changes in the haversian canals: simple occlusion of the haversian vessels with loss of cells in the canal, and dilatation of the capillaries with abnormal resorption of the perivascular bone matrix by osteoclasts. The abnormal bone resorption was not coupled with subsequent new-bone formation, resulting in increased porosity. Beginning at four weeks, a progressive decrease in the number of haversian vessels and in cellularity became prominent. The decrease in cellularity involved all types of cells, including endothelial cells, pericytes, perivascular mesenchymal cells, osteoblasts, osteocytes, and osteoclasts. The loss of perivascular cells was often but not always associated with occlusion of the haversian vessels. Histomorphometry revealed both time-dependent and dose-dependent decreases in capillary density (the number of intraosseous capillaries per unit area) and in the number of osteocytes in the subchondral bone plate. The porosity of the same areas showed a significant increase by four weeks (p < 0.001 after administration of twenty-five gray and p < 0.01 after administration of both fifty and 100 gray), but between twelve and fifty-two weeks, there was only a slight additional increase. Statistical analysis revealed significant correlations between capillary density and osteocyte survival (p < 0.001) and between capillary density and porosity (p < 0.001). The portion of the subchondral bone plate that was located farthest from the non-irradiated normal bone showed progressive damage and no sign of recovery at fifty-two weeks.

Slipped upper femoral epiphysis after radiotherapy.

Eight slipped upper femoral epiphyses in patients who had had radiotherapy are described. These cases involved five patients in an "at risk" population of 48. This increased incidence is highly significant.

Biochemical parameters of osteogenesis in epiphysis of mice irradiated and repopulated with syngeneic bone marrow.

Whole-body irradiation of BALB/cann mice with 600 R of gamma rays produces a profound atrophy of the spleen and diminishes alkaline phosphatase activity in the homogenates of epiphysis. The acid phosphatase activity remains unchanged until day 10, then slightly declines. Incorporation of 45Ca into epiphysis is practically not impaired following irradiation. Repopulation of irradiated animals with 1-1.5 million nucleated syngeneic bone marrow cells restores spleen weight within 6 days, but until day 11 the activity of alkaline phosphatase of epiphysis remains lower. Full recovery of enzyme activities was not observed until day 14, but on day 28 these activities returned to the normal level. Histological inspection did not reveal a full recovery of bone marrow in the epiphysis of irradiated animals until day 14, possibly because of trapping of the vast majority of stem cells by the spleen and liver. On day 28, however, epiphyses were completely filled with the bone marrow.

[Effects of high-energy shock waves on the structure of the immature epiphysis--a histomorphological study]. / Wirkung hochenergetischer extrakorporaler Stosswellen auf Wachstumsfugen--Eine histomorphologische Studie.

AIM: Extracorporeal shock wave treatment of infantile skeleton diseases is theoretical reasonable. The aim of this study was to investigate if extracorporeal shock wave therapy (ESWT) may cause damage to the epiphysis within the energy range of human application doses. METHOD: 18 rabbits were treated with 800 extracorporeal shock waves (Philips lithotripter LDM-E, energy density 0.32 mJ/mm(2)) at the proximal tibia epiphysis. At 72 hours, 14 days and 4 weeks each after shock wave application 6 rabbits were sacrificed. RESULTS: Histological examination showed no damage to the epiphysis in all treated subjects. CONCLUSION: This experimental study demonstrates that, under the conditions used in human shock wave therapy, no damage to the rabbit epiphysis occurs.

Osteochondroma following irradiation. Case report and review of the literature.

A case of an osteochondroma of the distal radius appearing 10 years after irradiation for hemangioma in infancy is described. The literature is reviewed and the effects of irradiation on bone growth, and possible malignant change, are discussed.

Protective effect of melatonin against fractionated irradiation-induced epiphyseal injury in a weanling rat model.

The effects of melatonin, a free-radical scavenger and a general antioxidant, on radiation-induced growth plate injury have not been studied previously. The purpose of this study was to determine the potential benefits of sparing longitudinal bone growth by fractionated radiotherapy alone compared with pretreatment with melatonin that provides differential radioprotection of normal cells. Weanling 4-wk-old (75-100 g) male Sprague-Dawley rats were randomly assigned to one of three groups: Group R received fractionated radiation alone (n = 8); groups M5 (n = 8) and M15 (n = 7) received 5 or 15 mg/kg melatonin prior to fractionated radiation, respectively. The distal femur and proximal tibia in the right leg of each animal were exposed to a therapeutic X-irradiation dose (25 Gy total in three fractions) with the contralateral left leg as the non-irradiated control. Melatonin was administered intraperitoneally to the animals 30 min before radiation exposure. Six weeks after treatment, the rats were killed and the lower limbs disarticulated, skeletonized, radiographed, and bone growth was calculated based on measurement of the bone lengths. Fractionated radiation resulted in a mean percent overall limb growth loss of 41.2 +/- 9.5 and a mean percent overall limb discrepancy of 11.2 +/- 2.2. The administration of 5 or 15 mg/kg melatonin before each of the three fractions of radiotherapy reduced the mean percent overall limb growth loss to 33.9 +/- 5.8 and 32.2 +/- 4.5, respectively, and the mean percent overall limb discrepancy to 9.4 +/- 1.6 and 8.9 +/- 1.1, respectively; these values were significantly different compared with irradiation alone (range: P = 0.01-0.04). When compared with Group R, the growth arrest recovered by 5 or 15 mg/kg melatonin was 19.7 and 24.1% for the tibia, 7 and 18.6% for the femur, and 17.7 and 21.8% for the total limb, respectively. These results support further investigation of melatonin in combination with fractionation for potential use in growing children requiring radiotherapy to the extremity for malignant tumors.