RESUMEN
Doping is the use of a substance that artificially increases an individual's physical ability for competition purpose. Products and methods used in doping are not without risk, especially at cardiovascular level. Here we review the most common doping substances in sport and their cardiovascular consequences.
Asunto(s)
Enfermedades Cardiovasculares/inducido químicamente , Doping en los Deportes , Antagonistas de Receptores Adrenérgicos beta 2/efectos adversos , Anabolizantes/efectos adversos , Transfusión de Sangre Autóloga/efectos adversos , Cannabinoides/efectos adversos , Enfermedades Cardiovasculares/prevención & control , Estimulantes del Sistema Nervioso Central/efectos adversos , Diuréticos/efectos adversos , Eritropoyetina/efectos adversos , Glucocorticoides/efectos adversos , Antagonistas de Hormonas/efectos adversos , HumanosRESUMEN
99mTc-Sestamibi identifies the presence of hyperfunctioning autonomous parathyroid glands in patients with secondary hyperparathyroidism (SHP). The objectives of this study were: (i) to evaluate the interdependence between biochemical markers of SHP and 99mTc-Sestamibi uptake; and (ii) to determine whether 99mTc-Sestamibi uptake could be efficiently predicted by any combination of the former variables. Double-phase parathyroid 99mTc-Sestamibi uptake and total serum calcium, phosphorus, intact parathormone, 25-OH vitamin D and 1,25(OH) vitamin D determinations were performed simultaneously in 74 patients (36 female, 38 male) with SHP. Planar images of the neck and upper thorax were obtained in anterior view, 15 min (early phase) and 120 min (delayed phase) after the injection of 740 MBq of 99mTc-Sestamibi. In each patient, a final parathyroid/thyroid (P/T) activity index was obtained by adding the results of the P/T index of all parathyroid lesions. There was a significant correlation between intact parathormone levels and delayed 99mTc-Sestamibi uptake ( r=0.656; P<0.01). Of all the variables, intact parathormone was the only significant predictor of delayed 99Tc-Sestamibi uptake ( r=0.487; P<0.001). Calcium, phosphorus, vitamin D metabolites, age, gender, time spent on haemodialysis and cause of chronic renal failure displayed no significant correlation with 99mTc-Sestamibi uptake. It can be concluded that 99mTc-Sestamibi uptake is a potential predictor of parathyroid function in SHP patients. Hence, 99mTc-Sestamibi scintigraphy could be useful to assess parathyroid function and in the clinical follow-up of these patients.
Asunto(s)
Hiperparatiroidismo Secundario/sangre , Hiperparatiroidismo Secundario/diagnóstico por imagen , Hormona Paratiroidea/sangre , Tecnecio Tc 99m Sestamibi , Vitamina D/análogos & derivados , Factores de Edad , Biomarcadores/sangre , Calcio/sangre , Dihidroxicolecalciferoles/sangre , Humanos , Hiperparatiroidismo Secundario/diagnóstico , Hiperparatiroidismo Secundario/etiología , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Glándulas Paratiroides/diagnóstico por imagen , Glándulas Paratiroides/metabolismo , Fósforo/sangre , Cintigrafía , Radiofármacos , Diálisis Renal , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Factores Sexuales , Estadística como Asunto , Vitamina D/sangreRESUMEN
OBJECTIVE: To evaluate whether the addition of an ossein-hydroxyapatite compound (OHC) may improve the effect of hormone replacement therapy (HRT) on postmenopausal bone loss. STUDY DESIGN: Of the 118 recent surgically postmenopausal women initially selected for this open study, 96 completed one-year follow-up. Patients were allocated into four groups. The first group received 50 micrograms/d of transdermal 17-beta estradiol continuously (group E, n = 23), the second received 3.32 g/d of an OHC every day (group OHC, n = 23), the third received 50 micrograms/d of transdermal 17-beta estradiol continuously plus 3.32 g/d of the OHC every day (group E-OHC, n = 26), and an additional 24 women were used as untreated controls (group C). Bone mass, assessed by dual x-ray absorptiometry, was measured prior to and at the end of treatment. Samples, including serum calcium, phosphate and osteocalcine level, were collected before therapy and during the 6th and 12th treatment months. RESULTS: All treatment groups showed an increase in bone mineral content. This increase was higher in the E-OHC group (4.7%, P < .01). Concomitant biochemical effects at 6 and 12 months were compatible with the observed effects on bone mineral. CONCLUSION: The combined regimen of OHC and HRT increased vertebral bone mass in postmenopausal women to a greater extent than did OHC or HRT alone, suggesting that this drug combination may be useful in the management of postmenopausal bone loss.
Asunto(s)
Materiales Biocompatibles/uso terapéutico , Durapatita/uso terapéutico , Estradiol/uso terapéutico , Terapia de Reemplazo de Estrógeno , Osteoporosis Posmenopáusica/prevención & control , Administración Cutánea , Adulto , Materiales Biocompatibles/administración & dosificación , Densidad Ósea , Quimioterapia Adyuvante , Durapatita/administración & dosificación , Estradiol/administración & dosificación , Femenino , Humanos , Persona de Mediana Edad , Ovariectomía , Resultado del TratamientoRESUMEN
Radioimmunoscintigraphy (RIS) and radioimmunoguided surgery (RIGS) were assessed for their usefulness in patients with colorectal carcinoma. Twenty-nine patients (18 primary tumours, 10 with a suspicion of recurrence and one colonic diverticulitis) were studied. Radioimmunoscintigraphy was performed 48 and 72 h after the injection of an anti-TAG72 monoclonal antibody (CYT-103) labelled with 111In. Radioimmunoguided surgery was performed between 72 and 96 h post-injection. During surgery, a systematic screening was performed with a hand-held gamma detecting probe and a surgical index (tumour-to-normal tissue) was obtained. There were statistically significant differences between counts in normal tissue versus tumour (P < 0.001) and RIGS was considered positive for the detection of tumour if the ratio between the counts in the area suspicious of tumour and the counts in the normal tissue was greater than 1.5. The overall sensitivity for RIS and RIGS was 71.4% (55.6% in primary tumours and 100% in recurrences) and 82.1% (83.3% in primary tumours and 80% in recurrences), respectively. Radioimmunoguided surgery changed the surgical procedure in two cases with small tumour deposits. Occult regional lymph node involvement in primary tumours was not found; therefore, RIGS, as a complementary technique to RIS, is particularly useful in recurrences and can help the surgeon in the resection of small tumour deposits which are difficult to localize.
Asunto(s)
Anticuerpos Monoclonales , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/cirugía , Radioisótopos de Indio , Oligopéptidos , Ácido Pentético/análogos & derivados , Radioinmunodetección , Adulto , Anciano , Anciano de 80 o más Años , Antígenos de Neoplasias/inmunología , Colon/diagnóstico por imagen , Colon/cirugía , Femenino , Glicoproteínas/inmunología , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico por imagen , Radiofármacos , Recto/diagnóstico por imagen , Recto/cirugía , Sensibilidad y EspecificidadRESUMEN
Helicidine is a biological extract prepared from the snail Helix pomatia L. and used in man as an anti-tussive agent. However, its mechanisms of action are not fully defined. In this study, we have investigated a possible relaxant effect of helicidine on guinea-pig airway smooth muscle and evaluated the role of prostanoids and airway epithelium in this relaxation. H. pomatia extract (0.001-1 mg/ml) induced a dose-dependent relaxation of guinea-pig trachea pre-contracted with histamine both in the presence and absence of tracheal epithelium. No significant difference in dose-dependency or magnitude of the relaxation was observed between tracheal segments with or without epithelium (maximal relaxant response of 35 +/- 7 and 25 +/- 7.5%, respectively). Relaxation of the trachea induced by H. pomatia extract (0.001-1 mg/ml) was inhibited by pre-treatment with the cyclooxygenase inhibitor, indomethacin, both in the presence or absence of tracheal epithelium. H. pomatia extract (1 mg/ml) induced a marked and significant increase in prostaglandin E2 release in tracheal segments with and without epithelium. These results indicate that helicidine possesses a broncho-relaxant activity which is independent of epithelium integrity and which is partly mediated by the release of the relaxant prostanoid, prostaglandin E2. The origin of prostaglandin E2 production in the airways remains to be defined.
Asunto(s)
Broncodilatadores/farmacología , Dinoprostona/metabolismo , Caracoles Helix , Extractos de Tejidos/farmacología , Tráquea/efectos de los fármacos , Animales , Inhibidores de la Ciclooxigenasa/farmacología , Evaluación Preclínica de Medicamentos , Eicosanoides/biosíntesis , Cobayas , Indometacina/farmacologíaRESUMEN
BACKGROUND: Injectable calcitonin is effective in reducing spinal bone loss in steroid-dependent asthma but side effects are frequent. In contrast, a nasal spray presentation has been shown to be effective and well tolerated in involutional osteoporosis. To test the efficacy of nasal calcitonin a two year prospective trial was conducted in 44 steroid-dependent asthmatic patients. METHODS: All patients received a calcium supplement of 1000 mg and were allocated randomly into two groups treated with either salmon calcitonin nasal spray (200 IU every other day, n = 22) or calcium alone (n = 22) for two years. All patients completed the first year of the study. Five patients in each group dropped out during the second year. In the calcitonin group one patient developed generalised pruritus and four lost steroid dependence, and in the calcium alone group five were no longer dependent on steroids. The efficacy of treatment was evaluated as follows: bone turnover assessed by biochemical markers, bone loss assessed by serial measurement of lumbar spine density, and rates of bone fractures. RESULTS: The bone mass in the calcitonin group increased by 2.7% in the first year while in the group receiving calcium alone it decreased by 2.8%; this difference was significant. Calcitonin prevented more bone loss during the second year while the calcium alone group continued losing bone mass (-7.8%). The difference between means was 0.1077 (95% CI 0.0381 to 0.1773). Three new fractures occurred in both groups. No changes in biochemical parameters were detected in either group. CONCLUSIONS: Calcitonin given intranasally increased spinal bone mass during the first year of treatment and maintained bone mass in a steady state during the second year. These results suggest that calcitonin may be a useful agent to prevent steroid-induced osteoporosis. However, the lack of effect of calcitonin on the rate of vertebral fractures does not permit its recommendation for routine use in preventing steroid-induced osteoporosis.
Asunto(s)
Asma/fisiopatología , Densidad Ósea/efectos de los fármacos , Calcitonina/uso terapéutico , Glucocorticoides/efectos adversos , Osteoporosis/prevención & control , Administración Intranasal , Anciano , Calcio/uso terapéutico , Esquema de Medicación , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Fracturas Óseas/prevención & control , Glucocorticoides/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Osteoporosis/inducido químicamente , Estudios ProspectivosRESUMEN
Thirty patients diagnosed as having systemic amyloidosis (six with primary amyloidosis and 24 with secondary amyloidosis) were given bone scans with 99Tcm-methylene diphosphonate in order to evaluate the skeletal and extra-osseous uptake and their clinical-scintigraphic correlation. Extra-osseous uptake appeared in nine instances, more frequently in primary (5/6) than in secondary (4/24) amyloidosis. Fourteen patients had clinical and echocardiographic suspicion of cardiac amyloidosis but only one showed cardiac uptake. Six patients had probable hepatic involvement but in only two cases was hepatic uptake seen. The extra-osseous uptake suggests the presence of amyloid deposits in the organs and soft tissues which take up the bone tracer. The absence of any uptake does not rule out amyloid infiltration.
Asunto(s)
Amiloidosis/diagnóstico por imagen , Huesos/diagnóstico por imagen , Adulto , Anciano , Amiloidosis/fisiopatología , Calcio/fisiología , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fósforo/fisiología , Cintigrafía , Medronato de Tecnecio Tc 99mRESUMEN
Differences in the I-131 uptake by 14 metastatic lesions from well-differentiated thyroid carcinoma and 12 local remnants of normal thyroid tissue before and after an adjuvant therapy with lithium carbonate, were observed. After the adjuvant treatment and administration of an I-131 tracer dose, a considerable increase of radioiodine uptake in all metastatic lesions was found (P less than 0.001), but only a slight increase was found in 50% of the normal tissue. The response to lithium carbonate by neoplastic tissue seems to be different than that of the normal thyroid tissue, and produces a lengthening of the average I-131 biologic life that could be helpful when treating well-differentiated thyroid carcinoma.
Asunto(s)
Adenocarcinoma/radioterapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Radioisótopos de Yodo/administración & dosificación , Litio/administración & dosificación , Neoplasias de la Tiroides/radioterapia , Adyuvantes Farmacéuticos , Adolescente , Adulto , Anciano , Femenino , Humanos , Radioisótopos de Yodo/uso terapéutico , Litio/uso terapéutico , Carbonato de Litio , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia/diagnóstico por imagen , CintigrafíaRESUMEN
The effect of serotonin (5-HT) on cyclic AMP levels in rat hypothalamic slices was age-dependent. The sensitivity of the cyclic AMP system to 5 X 10(-5) M 5-HT already existed in the foetus at 21 days of pregnancy. It reached a maximum on the 7th postnatal day and then decreased with age. In adult tissue the response was still present and was antagonized by two serotonergic antagonists (methiothepin and metergoline). When compared to the progressive increase of 5-HT level in the hypothalamus the data suggest a different evolution of serotonergic innervation and of 5-HT receptors.
Asunto(s)
AMP Cíclico/metabolismo , Hipotálamo/metabolismo , Serotonina/farmacología , Envejecimiento , Animales , Relación Dosis-Respuesta a Droga , Femenino , Feto/metabolismo , Hipotálamo/efectos de los fármacos , Hipotálamo/crecimiento & desarrollo , Masculino , Norepinefrina/farmacología , Embarazo , Ratas , Antagonistas de la Serotonina/farmacologíaRESUMEN
Kinetics of 3H serotonin accumulation into slices from hypothalamus have been compared in adult, puppy and foetus rat. In 15 days-old, as in adult rat, there are two components of 5 HT accumulation corresponding to the low and high affinity transport systems. For this latter, Km and Vmax values are much higher in adult than in 15 days old rat (in adult, Km=1,3 X 10(-7) and Vmax=0,33 X 10(-10); in 15 days old rat, Km=0,5 X 10(-7) and Vmax=0,125 X 10(-10)). On the opposite, in the 7 days old rat and in the 21 days old foetus, it is only possible to arbitrarely define one uptake system corresponding to the following apparent values: in the 7 days old rat, Km= 5 X 10(-7) and Vmax=2 X 10(-10), in the foetus, Km=0,2 X 10(-7) and Vmax=0,15 X 10(-10). These results showed important developmental differences in affinity of 3H serotonin to hypothalamus. The low and high affinity uptake systems existing in adult are only individualized in the 15 days old little rat.