[Health promotion through physical activity: territorial models and experiences]. / Promuovere la salute attraverso l'attività motoria: modelli ed esperienze territoriali.

Scientific evidences support the preventive role of physical activity in relation to different multifactorial pathologies. Health's promotion through the spreading of lifestyles that encourage movement, does not represent just an action in contrast with "sedentary life" risk-factor, but also a priority for "quality" of life, with relevant economical and social benefits. WHO indicates physical activity as one of the priorities for an effective prevention. Besides, the EU supports the realization and the diffusion of some prevention-programs. Main pilot experiences developed in Italy and other countries are summarized. Attention is focused on the role of the competences and structures involved in an integrated approach based on availability of medical support, social services and local structures, considering recent developments in health prevention and promotion. In Italy and Europe, new opportunities to implement health promotion through physical activity are offered by the development of higher education in movement and sport sciences.

Detection of metazoan species as a public health issue: simple methods for the validation of food safety and quality.

Species identification represents a critical issue in food chain safety and quality control. Several procedures are available to detect animal proteins in cattle feed or to trace transgenic foods. The most effective approach is based on the use of DNA as a marker. Amplification of DNA provides rapid, sensitive and specific protocols. Several target genes can be used, but new insights come from the mitochondrial genome, which is naturally amplified in each cell and shows a remarkable resistance to degradation. These are key points when analysing complex matrices such as foods, animal feedstuff or environmental samples. Traceability is important to prevent BSE or to monitor novel foods, such as genetically modified organisms. Amplification is commonly performed, but it requires expertise and a molecular biology laboratory to perform restriction analysis, electrophoresis or gel staining for the visualisation of results. Hereby, we consider a strategy based on multiple nested amplification and reverse hybridisation assay that virtually requires only a thermocycler and a water bath. The protocol is rapid and simple and can simultaneously detect different species in a DNA sample. This promising approach allows microarray developments, opening up to further perspectives. An international application has been published under the patent cooperation treaty. Presently, a ban on feeding ruminants on cattle-derived proteins is in force in Europe and USA. The identification of metazoan traces in a sample is not only a mere preventive measure for BSE, but represents a possible screening system for monitoring biotechnology products and procedures, as well as a quality control strategy to assure consumer's rights.

[Experimental effects of olpadronate and pamidronate on bone mass]. / Efectos experimentales de olpadronato y pamidronato sobre la masa ósea.

Ovariectomy and immobilization in rats have demonstrated to be useful models for osteopenia and they are considered to mimic some aspects of human osteoporosis associated with a deficit of ovarian hormones and the absence of mechanical function (disuse of the bone). Pamidronate (APD) and Olpadronate (OLPA), a new dimethylated aminobisphosphonate, on a continuous oral scheme (APD: 8 and OLPA: 0.8 mg/kg/day) or on an intermittent parenteral scheme (APD: 1.25 and OLPA: 0.075 mg/kg every 15 days) did effectively prevent the trabecular bone loss caused by immobilization (unilateral sciaticectomy), by lack of ovarian stimuli (bilateral ovariectomy) or by both approaches. There were no signs of deterioration in the cortical bone mass. In a model of preestablished osteopenia, caused by estrogen deprivation, OLPA stopped the progression of the bone mass loss (0.5 mg/kg/i.v. every 15 days) and restored (0.30-0.60 mg/kg/i.v. every 15 days) the bone mineral density which had been affected (trabecular and cortical). The different activity of OLPA and APD on trabecular and cortical regions of long bones seems to accompany their different responses because of negative stimulus: better responses were more evident in the trabecular bone which proved to be more labile. In these "in vivo" models of OLPA's efficacy was similar to APD's but it was roughly 5-10 times more potent. OLPA has a high safety margin. Therefore, it could advantageously be used in those bone diseases which benefit with the use of bisphosphonates.

[Preclinical toxicology of bisphosphonates]. / Toxicología preclínica de bisfosfonatos.

Bisphosphonates regulate bone turnover by inhibiting osteoclastic bone resorption. Due to their pharmacodynamic and pharmacokinetic characteristics, bisphosphonates have a special pharmacotoxicological profile related to their high degree of specificity: low or non-existent distribution in soft tissues and strong affinity for calcified tissues. Some general conclusions may be drawn from the pre-clinical toxicological studies, whose main aim is to identify the toxicity target organ/s and estimate the safety margins of a "prospective therapeutic agent" in laboratory animals. They are based on our own results and on data from the available literature as regards various bisphosphonates: Alendronate, Clodronate, Etidronate, Olpadronate and Pamidronate. Generally, very high doses of bisphosphonates are required to produce in different levels and incidence various extra-skeletical toxic side effects: local reaction, hypocalcemia (and its consequences on the cardiovascular system and the possibility of tetany), affection of the dental structures and renal dysfunction. Most of side effects may be related to the low solubility in biological fluids, the formation of calcium complexes, the potent inhibitory effect of endogenous or induced bone resorption as well as to its main excretion pathway. Some other side effects (on the eye, lungs and liver), may be related to repeated excessive high doses. A safety margin of 200 to 300 : 1 between the "toxic" and "pharmacological" doses may be estimated if the total quantity of Olpadronate given to various animal species in toxicological studies and in pharmacodynamic experimental models (osteopenias due to estrogen deprivation or immobilization and retinoid-induced hypercalcemia) is considered. If the toxic doses in animals are related to the highest doses suggested for human beings, then the ratio increases from 300 to 1000 : 1 depending on the pathology and the route of administration. As regards their effect on the bone, experimental data with the new bisphosphonates suggest a significant dissociation between pharmacologically active doses and those ones producing defective mineralization. The excessive inhibition of bone remodelling, due to the use of high doses in normal animals, is the natural consequence of the pharmacological effect of this family of compounds. A bisphosphonate's toxic potential effect on bone should not be evaluated in normal animals but in particular situations with a high bone turnover. Furthermore, the doses should be adjusted in order to regulate the magnitude of bone remodelling inhibition so as to take it to a normal level without totally suppressing it. Potency, safety margins, doses and proper administration schemes, should be considered as key elements for the optimum use of the therapeutic potentiality of these compounds.

Intravenous olpadronate restores ovariectomy-affected bone strength. A mechanical, densitometric and tomographic (pQCT) study.

Female Wistar rats aged 3 months were ovariectomized (OX, n = 27). Three months later they were given i.v. doses of 150 (6), 300 (7), or 600 (6) ug/kg 2/wk of olpadronate during 12 weeks or left as OX controls (OXc). Bending fracture load of femur diaphyses, reduced in OXc, was recovered by olpadronate. This effect was paralleled by changes in material quality indicators as DEXA-BMD, tomographic (volumetric) BMD, elastic modulus, and maximum elastic stress of cortical bone. No changes were induced by any of the treatments on cross-sectional area or moment of inertia. Diaphyseal stiffness, not reduced by OX, was enhanced to overnormal values by olpadronate at any dose. None of the treatments affected the normal mechanostatic interrelationships between cross-sectional architecture and bone material quality indicators. The positive effects described point out important differences in bisphosphonate action on bone biomechanics according to the experimental conditions assayed.

Effects of large doses of olpadronate (dimethyl-pamidronate) on mineral density, cross-sectional architecture, and mechanical properties of rat femurs.

As part of a safety-assessment study, doses of 8, 40, and 200 mg/kg per day, 6 days per week, of sodium olpadronate (dimethyl-APD, Me2-APD) were given by gavage to 10-week-old male and female rats during 27 weeks. Only the 200 mg/kg per day dose provoked toxic effects and a meaningful growth depression, regardless of the animal gender. In male animals, doses of 40 or 200 mg/kg per day improved strength, stiffness, and cross-sectional moment of inertia (CSMI) of femur diaphyses despite the toxic effects observed at the highest dose. Changes in bone mechanical properties were a consequence of those induced in CSMI. Regression analyses showed a treatment-induced improvement in bone modeling (as assessed by CSMI) for the same level of bone material stiffness (as expressed by calculated values of elastic modulus). The high dependency of results on body mass bearing suggested that these effects were exerted through an increase in the efficiency of bone mechanostat. Strikingly, they were not evident in female rats. If not related to a lower bone bioavailability of bisphosphonates in female rats as described by others, this phenomenon may have reflected: (1) their a smaller biomass; and/or (2) a less effective mechanostatic regulation of bone architecture derived from a higher bone material stiffness related to male animals. An increase of BMD with a predominance toward the distal region was observed in all femurs studied. This effect, unrelated to the observed changes in mechanical properties, seems to express a lack of remodeling of primary cartilage or bone tissue.

Serum kinetics, bioavailability and bone scanning of 99mTc-labelled sodium olpadronate in patients with different rates of bone turnover.

The activity of olpadronate labelled with technetium-99m(99mTc) was monitored in plasma and urine samples after single oral (925 MBq 99mTc/10 mg, coadministered with 50 mg cold drug) and intravenous (925 MBq 99mTc/5 mg) administrations to two groups of patients with different rates of bone turnover. The first group comprised high bone turnover (HBTO) patients suffering from Paget's bone disease; the second group comprised patients with normal to low bone turnover (NBTO) having the diagnosis of rheumatoid arthritis and secondary osteoporosis. Kinetic variables were correlated with anthropomorphometric variables, biological markers of bone metabolism and plasma proteins. Data were also obtained after repeatedly dosing the HBTO patients. Additionally, Paget's bone and healthy bone (PB/HB) uptake before and after low-dose oral treatment were assessed by means of scintigraphy. Results showed that most of the kinetic variables did not differ between the two groups of patients, except for a greater Vss and smaller blood area under the curve AUC in the patients with HBTO. After a repeated-dose administration period, the blood AUC activity and Whole Body Retention (WBR) of the HBTO patients tended to be similar to those of the NBTO patients. In both groups, after oral dosing, the Cmax was 20 times lower than the C0.5 after i.v. injection, and the oral bioavailability ranged from 3% to 4%. Finally, the plasma t1/2 beta ranged from 9 to 14 h. Correlation coefficients were obtained from multiple regression analysis; kinetic variables showed very low correlations with anthropomorphometric measurements. In contrast the Vss and WBR were significantly correlated with serum alkaline phosphatase levels and the Vss also with urine hydroxyproline levels. Plasma protein concentration was also correlated with excretion parameters such as CLP and plasma t1/2 beta after an oral dose. Scintigraphic studies in the HBTO group allowed bone selectivity to be seen through skeletal drug uptake. The 15 Pagetic lesions analysed in the HBTO group showed a decrease in PB/HB ratio from 3.8 in the basal study to 2.7 after olpadronate administration for 30 days at the rate of 50 mg/day. In conclusion, the kinetic profile of 99mTc-labelled olpadronate, mainly AUC and WBR, showed a dependence upon bone metabolism and seemed unrelated to body size variables. HBTO patients showed a lower blood AUC but a higher Vss. Both variables may have been reflecting the fact that the drug binds selectively with calcified tissues and, in turn, with the target compartment. Scintigraphy confirmed the labelled-compound bone selectivity as a desirable feature for a bone-scanning agent.

Determination of femur structural properties by geometric and material variables as a function of body weight in rats. Evidence of a sexual dimorphism.

Femur diaphyses of male and female Wistar rats were densitometrically and biomechanically assayed. The BMD-dependent material properties were better in female than in male bones, but cross-section geometric properties were better in male femurs. As a result, mechanical properties of the integrated diaphyses were better in males, but differences disappeared after statistical adjustment of data to a common body weight. Results evidence a feed-back mechanism locally controlling the strain-dependent bone modelling and the corresponding cross-sectional design as related to bone stiffness, with a set-point adjusted to animal biomass. A sexual dimorphism of bone biomechanics is also described for the species.

Protective effects of disodium etidronate and pamidronate against the biomechanical repercussion of betamethasone-induced osteopenia in growing rat femurs.

To assess the protective effect of bisphosphonates on the biomechanical repercussion of glucocorticoid-induced osteopenia, intraperitoneal doses of 1 or 10 mg/kg/d of disodium etidronate or 1 or 50 mg/kg/day of pamidronate were given to groups of 6 growing rats simultaneously receiving subcutaneous doses of 4.8 mg/kg/day of betamethasone for 20 days. Betamethasone impaired strength and stiffness of femur diaphyses through a reduction of geometric properties, abnormally enhancing bone ability to absorb energy. Both bisphosphonates partially prevented betamethasone effects on diaphyseal stiffness (but not strength) through positive, dose-related effects on material modulus of elasticity and slighter improvements in diaphyseal geometry, avoiding the enhancement of energy-absorbing ability and the subsequent tendency to production of comminute fractures. These results and others obtained treating normal rats with (pamidronate) APD suggest that the sign of bisphosphonate effects on bone biomechanics may depend not only on the type of compound but also on eventual interactions with concomitant treatments.

Osteoporosis: detección, prevención, tratamiento / Osteoporosis: detection, prevention and treatment

El síndrome osteoporótico se caracteriza por una merma en la cantidad (osteopenia) y deterioro de la calidad (microarquitectura) de la mineralización ósea. Se trata de trastornos heterogénos originados por múltiples causas metabólicas, poco conocidas. Se diagnostica por la presencia de deformaciones óseas o fracturas de origen no traumático. La detección precoz de la osteopenia es importante y se considera que los individuos cuya densidad mineral ósea (BMD) es inferior al 80// del normal están más expuestos a fracturas. La fosfatasa alcalina sérica, la hidroxiprolina y las piridinolinas urinarias son marcadores bioquimicos. Se insiste en los aspectos nutricionales y de movimientos físicos, para obtener una mayor masa ósea, especialmente durante el período de crecimiento. Es fundamental ingerir suficiente cantidad de calcio, y en las zonas más australes del país debe aumentarse el consumo de vitamina D. Los recursos terapéuticos tienden a prevenir la osteopenia de un modo más activo. Los estrógenos son muy utilizados en las mujeres postmenopáusicas. Son eficaces pero no para tratar la osteoporosis establecida y persisten todavía algunas dudas sobre su inocuidad a largo plazo. Las calcitoninas aumentan transitoriamente la mineralización vertebral y pueden ser utilizadas como alternativas de las terapias hormonales de reemplaxo. Los bifosfonatos presentan diferentes mecanismos de acción, p.ej., el pamidronato no es citotóxico por lo que no interfiere en el proceso de remodelación fundamental para mantener o mejorar la calidad arquitectónica del hueso. El efecto de los bisfosfonatos sobre la mineralización es duradero. Por ser drogas nuevas aún no han sido aprobadas en todos los países. Las sales de flúor han producido siempre resultados desconcertantes; algunos efectos benéficos iniciales no previenen las consecuencias adversas del uso prolongado. Las vitaminas D, el nitrato de galio y la ipriflavona producen resultados discretos que aún deben compararse con el de los agentes más activos. El empleo de otras drogas (tamoxifeno, los derivados de la parthormona, los factores de crecimiento, las tiazidas y los inhibidores de la bomba de protones) aún está en desarrollo. Se concluye que la osteoporisis es un proceso patológico que acompaña al envejecimiento y para el cual ya existen fármacos disponibles, en especial para prevenir la osteopenia y el deterioro de la calidad del hueso (AU)

Osteoporosis: detección, prevención, tratamiento / Osteoporosis: detection, prevention and treatment

El síndrome osteoporótico se caracteriza por una merma en la cantidad (osteopenia) y deterioro de la calidad (microarquitectura) de la mineralización ósea. Se trata de trastornos heterogénos originados por múltiples causas metabólicas, poco conocidas. Se diagnostica por la presencia de deformaciones óseas o fracturas de origen no traumático. La detección precoz de la osteopenia es importante y se considera que los individuos cuya densidad mineral ósea (BMD) es inferior al 80// del normal están más expuestos a fracturas. La fosfatasa alcalina sérica, la hidroxiprolina y las piridinolinas urinarias son marcadores bioquimicos. Se insiste en los aspectos nutricionales y de movimientos físicos, para obtener una mayor masa ósea, especialmente durante el período de crecimiento. Es fundamental ingerir suficiente cantidad de calcio, y en las zonas más australes del país debe aumentarse el consumo de vitamina D. Los recursos terapéuticos tienden a prevenir la osteopenia de un modo más activo. Los estrógenos son muy utilizados en las mujeres postmenopáusicas. Son eficaces pero no para tratar la osteoporosis establecida y persisten todavía algunas dudas sobre su inocuidad a largo plazo. Las calcitoninas aumentan transitoriamente la mineralización vertebral y pueden ser utilizadas como alternativas de las terapias hormonales de reemplaxo. Los bifosfonatos presentan diferentes mecanismos de acción, p.ej., el pamidronato no es citotóxico por lo que no interfiere en el proceso de remodelación fundamental para mantener o mejorar la calidad arquitectónica del hueso. El efecto de los bisfosfonatos sobre la mineralización es duradero. Por ser drogas nuevas aún no han sido aprobadas en todos los países. Las sales de flúor han producido siempre resultados desconcertantes; algunos efectos benéficos iniciales no previenen las consecuencias adversas del uso prolongado. Las vitaminas D, el nitrato de galio y la ipriflavona producen resultados discretos que aún deben compararse con el de los agentes más activos. El empleo de otras drogas (tamoxifeno, los derivados de la parthormona, los factores de crecimiento, las tiazidas y los inhibidores de la bomba de protones) aún está en desarrollo. Se concluye que la osteoporisis es un proceso patológico que acompaña al envejecimiento y para el cual ya existen fármacos disponibles, en especial para prevenir la osteopenia y el deterioro de la calidad del hueso

Biomechanical effects of the full range of useful doses of (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD) on femur diaphyses and cortical bone tissue in rats.

The effects of i.p. doses of 0.016, 0.16, 1.6, 5, 16, 50 and 160 microM/kg/day of APD, over a period of 23 days, on geometric and biomechanical properties of femoral diaphyses in bending were determined in groups of seven growing rats. Both elastic and ultimate strength increased with low doses and decreased with high doses. Geometric (mass) variables (diaphyseal volume, wall/lumen ratio) correlated positively, and material properties (limit elastic stress, modulus of elasticity) negatively, with log dose. Normal mass and improved quality at low doses, and improved mass and impaired quality data at high doses were obtained. No changes in sectional moment of inertia (Ix, an expression of bone architecture) were observed. Biphasic changes in diaphyseal strength expressed the effects of APD on material quality in spite of mass variation. The contrasting lack of changes in Ix may have reflected the blocking effect of APD on osteoclast-osteoblast communication, essential for directional modulation of remodelling.

Growth in Turner's syndrome: long term treatment with low dose ethinyl estradiol.

The growth response to 100 ng/kg BW X day ethinyl estradiol (2-4 micrograms/day) given for 18 months was studied in a group of nine patients with Turner's syndrome, aged 8.6-13.3 yr. All patients were prepubertal and had elevated gonadotropin levels. Growth velocity increased from 3.09 +/- 1.05 (+/-SD) to 7.09 +/- 1.47 cm/yr in the first 6 months, 6.08 +/- 1.78 cm/yr in the second 6 months, and 4.03 +/- 1.65 cm/yr in the third 6 months. Bone age increased a mean of 0.82 +/- 0.34, 0.89 +/- 0.79, and 0.74 +/- 0.59 yr, respectively, in the three 6-month periods. Predicted height prognosis did not change after any period. All patients had pubertal changes, limited in most to slight breast development. Mean diurnal spontaneous GH secretion did not change during treatment. Plasma somatomedin-C levels were low before treatment, and ethinyl estradiol did not significantly increase somatomedin-C values. Our data confirm the ability of a low dose of ethinyl estradiol to increase growth velocity in girls with Turner's syndrome, although the effect diminished with time, and the excess bone age advancement precluded improvement of predicted height.