[MICROECOLOGICAL CHANGES IN THE INTESTINE AND ITS EFFECT ON THE CONDITION OF HARD TISSUES OF TEETH IN ADOLESCENCE].

On the background of microecological changes in the gastrointestinal tract, mineral and protein metabolism is disrupted, biochemical changes occur in the phosphorus-calcium metabolism in the bones of the skeleton and hard tissues of the teeth. The aim of the research was to study the activity of the caries process, characterized by progressive decalcification, under conditions of microecological changes in the intestine and its effect on the processes of endogenous calcium assimilation in adolescence. Within the frames of the research 68 adolescents aged 11 to 17 years with various degrees of pathology of the gastrointestinal tract were examined. The data of the performed studies showed that in patients with more severe changes in the intestinal micro flora, the prevalence and intensity of dental caries are significantly higher (83.4% on average DMFT 5.0) than in adolescents with mild dysbiosis (71.8% DMFT 3.2% ), and in the patients with normal intestinal micro flora - the parameters were minimal. Estimating and comparing the interrelation between the incidence of caries and the presence of diseases of the gastrointestinal tract in adolescents, a directly proportional dependence of the DMF index on age was found, but the greatest increase in the individual level of incidence of dental caries (SIC) was observed in adolescents aged 14-16 (SIC=0,42) with severe gastrointestinal pathology GIT. Thus, significant changes in dental status detected in adolescents with pathology of the gastrointestinal tract confirm the validity of complex treatment and preventive dental care, considering the processes occurring in the body and the oral cavity, as well as the systematic, purposeful dental care and the allocation of patients with gastrointestinal pathology (GIT) in a separate group.

Bilateral choroidal osteoma: visual acuity at 45-year follow-up.

PURPOSE: To report a case of bilateral choroidal osteoma, which demonstrated different visual outcomes in both eyes over a long follow-up of 45 years. METHODS: Case report. RESULTS: After 45 years of follow-up, choroidal osteoma showed slight enlargement in each eye and choroidal neovascularization and retinal pigment epithelium (RPE) changes had developed in the right eye. Visual acuity of the right eye was decreased to 20/200 from macular RPE loss and choroidal neovascularization scarring. The left eye preserved a visual acuity of 20/30 where choroidal osteoma demonstrated only partial decalcification of the nasal margin with preservation of RPE in the macular region. Spectral domain optical coherence tomography of the right macula confirmed broad RPE and choroidal atrophy and scarring related to previous choroidal neovascularization. Spectral domain optical coherence tomography of the left macula showed preserved retinal layers and RPE with underlying calcified choroidal osteoma. CONCLUSION: Choroidal osteoma can occasionally demonstrate intact calcification, preserved RPE, and photoreceptors with excellent vision.

Importance of citrate and the calcium : citrate ratio in patients with calcium renal lithiasis and severe lithogenesis.

UNLABELLED: Different studies have shown the importance of citrate in the formation of calcium stones. It has further been shown that the states of metabolic acidosis result in an increase in bone resorption and lower urinary citrate levels. Increasing the intake of citrate in these patients can reduce the lithogenic risk and improve bone mineral density (BMD), contributing to control of both diseases. The study shows the importance of citrate in patients with calcium stones and BMD loss. The deficit in citrate excretion is associated with a decrease in bone mineralization and increased ß-crosslaps. A calcium : citrate ratio >0.25 in patients with calcium stones and loss of mineral density may predict severe lithogenic activity. OBJECTIVE: To analyse the importance of urinary citrate and the urinary calcium : citrate ratio in patients with calcium renal lithiasis and severe lithogenesis compared with a control group of patients without lithiasis. MATERIAL AND METHODS: A cross-sectional study of 115 patients in eastern Andalusia, Spain was conducted. The patients were divided into two groups: Group A: 56 patients aged 25-60 years without calcium renal lithiasis; Group B: 59 patients aged 25-60 years, presenting with calcium renal lithiasis and severe lithogenesis. The citrate levels and the calcium : citrate ratio in the patients' urine and the relationship of these two factors to lithiasic activity were analysed and compared. RESULTS: In Group B, 32.2% of the patients presented with hypocitraturia, compared with 14.3% of the patients in Group A (P = 0.02). The urinary citrate levels were lower in Group B than in Group A (P = 0.001) and the calcium : citrate ratio was higher in Group B than in Group A (P = 0.005). The results suggest that a patient urinary calcium : citrate ratio > 0.25 indicates severe lithogenesis (with a sensitivity of 89% and a specificity of 57%). After linear regression analysis, we found that the urinary citrate level is an independent factor associated with the changes in bone densitometry T-score values of patients. CONCLUSIONS: The patients with severe lithogenesis presented with hypocitraturia, which was associated with lower bone mineral density. The calcium : citrate ratio, which is linearly related to the bone resorption marker ß-crosslaps, could be useful in evaluating the risk of severe lithogenesis when this ratio is >0.25.

[Treatment of osteoporosis and osteopenia in children--own experience]. / Leczenie osteoporozy i osteopenii u dzieci--doswiadczenia wlasne.

Osteoporosis and osteopenia diagnosed in developmental age require special treatment with careful consideration of indications for particular drugs, their dosage and monitoring of treatment. The classical method, similarly as in adults, is administration of calcium and vitamin D, physical rehabilitation, treatment of fractures and pain release. The aim of the study was to evaluate the effect of combined therapy of decreased bone mineralization in 45 children (28 boys and 17 girls) aged 6.5 to 18 years. In 15 of them secondary osteoporosis (13/15) or osteopenia (2/15) were diagnosed, and in 30 cases the disorders were primary -16/30 and 14/30, respectively. The patients were treated from 6 months to 4 years. All patients received calcium and vitamin D preparations. In the majority of treated children calcium-rich diet and physical rehabilitation were applied, adjusted to the advancement of the disease. In 6 cases treatment with bisphosphonates was given. In our study we also present results and observations from calcitonin treatment of 35 children aged 6 to 18 years. This treatment was applied during the last 5 years in various periods--in 23 children with secondary and in 12 with primary osteoporosis. The therapy of osteoporosis and osteopenia in developmental age should always be individually assessed to disease advancement, symptoms, concomitant illnesses, age and possibilities of long-term treatment. The classical treatment includes appropriate intake of calcium, vitamin D and other vitamins and minerals (pharmacological preparations, diet), physical rehabilitation and pain release. On the basis of our observations it appears that antiresorptive drugs such as calcitonin and bisphosphonates may be used in treatment of osteoporosis in developmental age. Evaluation of treatment efficacy should involve clinical improvement and results of additional examinations, especially densitometry. Among biochemical tests, bone resorption markers (Pyr, Dpyr, CrossLaps) appeared to be the most useful; treatment of bone fractures should be evaluated by X-ray examinations.

Determination of regional bone blood flow by means of fluorescent microspheres using an automated sample-processing procedure.

The determination of regional blood flow utilizing fluorescent microspheres (FMs) is an established method for numerous organs. Recent progress, in particular the automation of sample processing, has further improved this method. However, the FM method (reference sample technique), which allows repetitive measurement of regional organ blood flow, has so far not been used for the determination of blood flow in bone. The aim of the present study was to establish FM for the quantification of regional bone blood flow (RBBF). Female, anesthetized New Zealand rabbits (n = 6) received left ventricular injections of different amounts of FM at six subsequent time points. In order to examine the precision of RBBF determination, two different FM species were injected simultaneously at the sixth injection. At the end of the experiments the femoral and tibial condyles of each hind limb were removed and the fluorescence intensity in the tissue samples was measured by an automated procedure. In an in vitro study we have shown that acid digestion of the crystalline matrix has no effect on the fluorescence characteristics of FM. The determination of the number of spheres per tissue sample revealed that depending on the tissue sample size up to 3 x 10(6) spheres/injection were necessary to obtain about 400 microspheres in the individual bone samples. RBBF values of the tibial and femoral condyles did not differ at various injection intervals. The tibial blood flow values varied between 6.6 +/- 1.1 and 8.5 +/- 1.4 ml/min/100 g and were significantly higher than those of the femur (4.3 +/- 1.1 to 6.0 +/- 1.8 ml/min/100 g). The bone blood flow values obtained by simultaneous injection of two FM species correlated significantly (r = 0.96, slope = 1.06, intercept = 0.05), the mean difference was 0.39 +/- 1.11 ml/min/100 g. Our data demonstrate that the measurement of RBBF by means of FM allows a valid determination of RBBF.

Avaliaçäo da atividade osteoindutora da matriz dentinária autógena descalcificada em defeitos ósseos cirúrgicos obtidos por craniotomia e tratados pela técnica de regeneraçäo óssea guiada / Evaluation of the osteoinductive property of autogenous deminerilized dentin matrix on surgical bone defects obtained for craniotomy and treated by the guided bone regeneration technique

O propósito deste trabalho foi avaliar a atividade osteoindutora da matriz dentinária autógena descalcificada (MDAD), em defeitos ósseos cirúrgicos experimentais no osso parietal de coelho, associada à regeneraçäo óssea guiada com o uso de Membrana Amniótica Humana (MAH) e Membrana de Politetrafluoretileno (MP). Nesta pesquisa, foram empregados 72 coelhos adultos com peso médio de aproximadamente 4,5Kg e divididos em dois grupos controles, MAH e MP, e dois grupos experimentais, MAH associada à MDAD e MP associada à MDAD. Após a confecçäo do defeito ósseo, nos grupos controles, as respectivas membranas foram colocadas na superfície e no assoalho da loja cirúrgica e a cavidade foi preenchida pelo coágulo sanguineo. Nos grupos experimentais, implantou-se fatias de MDAD na periferia do defeito ósseo e colocou-se membrana na superfície e no assoalho do defeito ósseo. Em seguida, procedeu-se à sutura do periosteo sobre as membranas e da pele. Decorridos 15, 30, 45, 60, 90 e 120 dias, três coelhos de cada grupo foram sacrificados. As peças contendo os defeitos ósseos foram removidas em bloco, fixadas em formol a 10 por cento e submetidas a análise macroscópica, análise radiográfica com radiografia digital direta, sistema DIGORA, e a análise microscópica. Os resultados obtidos possibilitaram concluir que a MAH e a MP näo interferiram no processo de reparo ósseo, a MP permaneceu na regiäo de implantaçäo durante todos os períodos estudados e a MAH foi reabsorvida. As fatias de MDAD estimularam a neoformaçäo óssea de forma direta, sendo rapidamente incorporadas ao osso neoformado e reabsorvidas durante o processo de remodelaçäo óssea

Technetium-99m-alendronate: a new radiopharmaceutical for bone scanning

The purpose of this paper is to report the preparation of a new technetium-99m-radiopharmaceutical for bone scanning. The chelating agent for99mTc is a new bisphosphonate, alendronate, 4-amino-1-hydroxy-butylidene-1,1-bisphosphonate (ABP) used as a treatment for osteoporosis. ABP, because of its amino group, seems to be better suited to form a strong and stable complex with technetium-99m and therefore might be better than 99mTc-etidronate (HEDP) or 99mTc-medronate (MDP) for bone scanning. A sterile dry kit containing APB, a reducing agent and a stabilizer was prepared. The parameters studied were molar concentrations, pH, shelf life, labeling efficiency and radiochemical purity. the oven dried sterile kit was formulated with 5 mg ABP, 0.25 mg stannous fluoride and 0.025 mg gentisic acid at pH2.5-3.5. The labeling efficiency with 20 - 1500 MBq of pertechnetate (99mTcO4-) was over 95 percent at room temperature and was stable for 5 h. Technetium-99m-alendronate was tested in two rabbits and it proved to be a promising new radiopharmaceutical for bone scanning. Work is underway to study underway to study 99m-Tc-ABP biodistribution in a statistically significant number of laboratory animals and, later on, to determine radiopharmacokinetic parameters in normal volunteers

The rate of osteoclastic destruction of calcified tissues is inversely proportional to mineral density.

This study examined the relative ease with which three dissimilar mineralized tissues from one individual organ were resorbed by osteoclasts in vitro. Cells released from the long bones of prehatch chicks by agitating fragments of the chopped bones in medium were cultured for 24 hours on slices cut from an Elephas maximus molar so that enamel, dentine, and coronal cementum were present in bands on the surface of the slice. The resultant pits were measured using a video-rate, line-confocal reflection light microscope system. Variations in tissue mineralization were characterized by analysis of digital backscattered electron images. The enamel pits were smaller than the dentine and the cementum pits, but the dentine and cementum pits were not significantly different from each other. The sizes of the pits correlated with the relative mineral densities of the three tissues, showing that the rate of osteoclastic destruction of calcified tissues is inversely proportional to mineral density. This indicates that the initial step in osteoclasis, the removal of the mineral phase, determines the volume removed and is the rate-limiting step.

[Fracture of the upper extremity of the femur in elderly women: respective role of fall and bone demineralization]. / Fracture de l'extrémité supérieure du fémur chez la femme âgée: rôle respectif de la chute et de la déminéralisation osseuse.

Fractures of the proximal femur in elderly individuals are becoming increasingly common in the industrialized world and represent a heavy burden in both socioeconomic and human terms. Two factors are key to the pathophysiology of these fractures: falls and decreased bone strength due to osteoporosis. Femoral and vertebral bone density was measured in 40 elderly women (83 +/- 5 years) who experienced a fall; in those who developed a femoral fracture as a result of the fall, femoral bone density was lower by 12 to 21% (z score: -0.7 to -1.04) than in those with no fracture, after adjustment for age, height and weight. Femoral neck and trochanteric area measurements had the best predictive value (area under the RoC curve: 75% +/- 8%). These was no difference by anatomic fracture type (neck or trochanter). Patients with pertrochanteric fractures had lower vertebral bone densities than controls. These findings, together with recent prospective data, demonstrate that in addition to falls, bone loss (osteoporosis) promotes the occurrence of fractures of the proximal femur in elderly patients. This has important practical implications for the detection and prevention of these fractures.