RESUMEN
OBJECTIVES: In the present study we investigate organochlorines as possible risk factors for Parkinson's disease (PD) in an arctic population. This has never been done before. STUDY DESIGN: Case-control study of Inuit in Greenland. MATERIALS AND METHODS: Plasma from 31 PD (20 males and 11 females) (mean age 69 yr) and 122 controls (57 males and 65 females) (mean age 61 yr) was analysed for 31 PCBs and pesticides by dual-column GC-ECD and GC-NCI/MS. RESULTS: Plasma concentrations of PCBs and pesticides were markedly increased in both PD and controls. The concentrations did not differ between the PD cases and controls. However, the mean DDE concentration was higher in PD than in controls (42.1 and 15.0 microg/l, respectively, and with a wide range among the PD cases). The difference was significant for log transformed DDE values after control for age and sex (p=0.005). CONCLUSION: A few epidemiological studies indicate a possible connection between exposure to pesticides and PD. The idea that exposure to organochlorines may be an important risk factor for PD among the Inuit in Greenland requires more investigations.
Asunto(s)
Hidrocarburos Clorados/toxicidad , Enfermedad de Parkinson/epidemiología , Estudios de Casos y Controles , Femenino , Groenlandia/epidemiología , Humanos , Inuk/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/etnología , Enfermedad de Parkinson/etiología , Factores de RiesgoRESUMEN
OBJECTIVE: In animals, somatostatin (SRIH) and growth hormone (GH)-releasing hormone (GHRH) increase feeding via a common neural mechanism. Furthermore, SRIH counteracts the suppressive action of corticotrophin-releasing hormone (CRH) on food intake. Hypothetically, SRIH could be involved in the central feeding mechanism in anorexia nervosa (AN). Peripheral administration of pyridostigmine (PD) minimizes the release of hypothalamic SRIH. DESIGN: To study the influence of hypothalamic somatostatinergic inhibition on the exaggerated somatotroph responsiveness to GHRH in patients with severe AN, two GHRH stimulation tests were performed in random order following pretreatment with placebo or PD 2 mg/kg body weight in 13 patients and in 10 age-matched healthy controls. The test procedure was repeated in the patients after weight gain. RESULTS: In controls, PD potentiated the GHRH-stimulated GH rise but this effect was absent in AN patients. The relative potentiating effect of PD was inversely correlated to cortisol excretion levels and positively correlated to leptin serum levels. After weight gain the relative PD effect increased twofold. CONCLUSION: The pyridostigmine-GHRH responsive pattern points indirectly to greater SRIH withdrawal and greater GHRH release in anorexia nervosa. Moreover, hypothalamic SRIH activity seems to be inversely related to cortisol levels, indirectly supporting the hypothesis that SRIH and CRH neuronal activity are inversely related in anorexia nervosa. Leptin, which is believed to act on hypothalamic feeding mechanisms, seems to be positively related to SRIH activity. Finally, the present data demonstrate that the potentiating effect of pyridostigmine in anorexia nervosa is related to body mass index and increases upon weight gain, suggesting that the low somatostatinergic tone is not primary but is related to the weight loss.
Asunto(s)
Anorexia Nerviosa/fisiopatología , Hormona de Crecimiento Humana/sangre , Hipotálamo/fisiopatología , Adulto , Anorexia Nerviosa/sangre , Índice de Masa Corporal , Inhibidores de la Colinesterasa , Sinergismo Farmacológico , Femenino , Hormona Liberadora de Hormona del Crecimiento/fisiología , Hormonas/sangre , Humanos , Leptina/sangre , Bromuro de Piridostigmina , Aumento de PesoRESUMEN
Anorexia nervosa (AN) is associated with multiple endocrine alterations. In the majority of AN patients, basal and GHRH-stimulated serum GH levels are increased. The metabolic effects of GH are known to be related to its pulsatile secretory pattern. The present study was performed to examine GH pulsatility in AN using the techniques of deconvolution analysis and approximate entropy, which quantify secretory activity and serial irregularity of underlying hormone release not reflected in peak occurrence or amplitudes. To this end, 24-h GH profiles were obtained by continuous blood sampling aliquoted at 20-min intervals in 8 nonfasting patients with AN [body mass index (BMI), 14.2 +/- 0.8 kg/m2; mean +/- SEM) and in 11 age-matched healthy women (BMI, 20.3 +/- 0.5 kg/m2). The deconvolution-estimated half-life of GH was not altered in the AN patients. The pituitary GH secretory burst frequency, burst mass, and burst duration were each significantly increased in women with AN compared to those in normal weight women. A 4-fold increase in daily pulsatile GH secretion was accompanied by a 20-fold increase in basal (nonpulsatile) GH secretion. There were significant negative correlations between BMI and the basal as well as pulsatile GH secretion rates. Moreover, AN patients exhibited significantly greater GH approximate entropy scores than the controls, denoting marked irregularity of the GH release process. In contrast to previous reports in healthy fasting subjects, cortisol levels in AN patients were positively correlated to GH secretion rates. Leptin levels were significantly inversely correlated to the pulsatile, but not the basal, GH secretion rate. The present data demonstrate augmented basal as well as pulsatile GH secretion with disruption of the orderliness of the GH release process in AN. Accordingly, GH secretion in AN probably reflects altered neuroendocrine feedback regulation, e.g. associated with increased hypothalamic GHRH discharge superimposed on reduced hypothalamic somatostatinergic tone.
Asunto(s)
Anorexia Nerviosa/fisiopatología , Hormona de Crecimiento Humana/metabolismo , Factor I del Crecimiento Similar a la Insulina/fisiología , Ciclos de Actividad/fisiología , Adulto , Anorexia Nerviosa/sangre , Anorexia Nerviosa/patología , Densidad Ósea , Retroalimentación , Femenino , Hormonas/sangre , Hormona de Crecimiento Humana/sangre , Humanos , Hidrocortisona/sangreRESUMEN
The aim of the study was to examine sequential changes in serum levels of the aminoterminal propeptide of type III procollagen (S-PIIINP) after acute myocardial infarction (AMI), and to assess the value of S-PIIINP as a predictor of outcome. The study group comprised 74 patients with AMI, and 24 patients in whom AMI was suspected but disproved. S-PIIINP changed characteristically after AMI, and in patients not receiving thrombolytic therapy or having cardiogenic shock, the changes correlated to peak enzyme values (r = 0.4, p < or = 0.03). S-PIIINP was higher at days 0 to 2 in nonsurviving AMI patients than in survivors (p < 0.05). With use of either the upper quartile for S-PIIINP at day 0 for nonsurviving AMI patients or the mean value of S-PIIINP in a normal population plus 2 SDs as a cutoff, the predictive value of a negative test ranged from 0.79 to 0.87 at days 0 to 2, and the predictive value of a positive test ranged from 0.39 to 0.67. Thus, S-PIIINP on admission and for the following few days after AMI is higher in patients with poor outcome.