[Multi-organ failure after massive Levothyroxine ingestion: case report]. / Insufficienza multiorgano da massiva ingestione volontaria di Levotiroxina: case report.

Levothyroxine is the drug of choice prescribed worldwide for the treatment of Hypothyroidism. The exact daily dosage, mode of consumption and refractoriness to therapy are still subject of discussion. The intoxication with levothyroxine is rare and with severe complications in adults; on the contrary, high prevalence and benign course is observed in pediatric age. We report the case of a 56 year-old woman, presented to the emergency department after intentional ingestion of massive levothyroxine overdose , with acute renal failure, severe disturbances of cardiovascular and central nervous system, that required intensive care support. In absence of a specific treatment, plasmapheresis has been used with good results, despite important clinical complications. In fact the clinical applications of plasmapheresis are rapidly increasing in number and scope: the plasmapheresis appears to be a very important tool for the treatment of acute and severe forms of thyrotoxicosis due to l-thyroxine intoxication.

[Sensorineural hearing loss in childhood: evaluation of economic impact in view of vaccine prevention of cases due to congenital cytomegalovirus infection]. / Sordità neurosensoriale infantile: valutazione dell'impatto economico nella prospettiva della prevenzione vaccinale dei casi da infezione congenita da Cytomegalovirus.

Sensorineural hearing loss (SNHL) is a serious public health problem which affects 1-3% per hundred live born babies in developed countries. The congenital cytomegalovirus (CMV) infection is its most important non-genetic cause. The evaluation of the effectiveness of future programs of anti-CMV vaccination requires an assessment of the present costs of SNHL. Direct costs for the Italian public system were calculated per prosthesis child until his full age and turned out to add up to 260,000 euro. Private costs are difficult to be assessed and anyhow are highly dependent from the socio-economic level. This preliminary assessment suggests that the vaccination would be cost-saving if SNHL cases due to congenital CMV were more than 21 per year, corresponding to a congenital infection prevalence higher than 0.21%o.

Interaction of beta-adrenergic antagonists with local anaesthetic acceptor sites.

H3-dihydroalprenolol (H3-DHA) binding in isolated smooth muscle cells has been studied. Two different binding sites have been detected: a high affinity (highly specific) and a low affinity (nonspecific) binding site. Local anaesthetics are able to displace H3-DHA from nonspecific sites with a rank order of potency that mirrors their local anaesthetic activity. This finding correlates, at the molecular level, with the local anaesthetic properties of beta-blockers, as concluded from classical pharmacological experiments.

Cytoplasmic free [Ca2+] is increased in the platelets of spontaneously hypertensive rats and essential hypertensive patients.

The cytoplasmic free calcium concentration [( Ca2+]i) was assessed with the fluorescent dye Quin 2 in platelets and lymphocytes of spontaneously hypertensive rats (SHR), normotensive Wistar-Kyoto rats (WKY), essential hypertensive patients (EHP) and normotensive human control subjects (NCS). [Ca2+]i was significantly higher in the platelets of 8- and 20-week-old SHR in comparison with WKY. However, no difference was evident after weaning. Changes of cellular calcium in hypertensive rats apparently evolved simultaneously with the development of high arterial pressure. [Ca2+]i was significantly higher in platelets of EHP than in NCS. In lymphocytes of SHR, [Ca2+]i was not different from WKY at 4 and 8 weeks, but was increased at 14 weeks and at older ages. In EHP, intralymphocytic [Ca2+] was only modestly higher than in controls. On the whole, the results suggest that control of cytoplasmic calcium in these blood cells is similarly affected in human and animal models of primary hypertension.

Regulation of arterial adrenoceptors during hypertension development in spontaneously hypertensive rats.

Diminished beta-adrenoceptor mediated relaxation and increased reactivity to norepinephrine have been observed in the arteries of spontaneously hypertensive rats (SHR). However, some reports are conflicting, while the complexity of endothelial, neural and purely morphological factors regulating the response of whole vessels is increasingly appreciated. Thus a dissection of the complex vascular contraction mechanism into single-step events is needed. Here characterization of adrenoceptors in isolated aortic smooth muscle cells of SHR by radioligand binding techniques is reported. The density of beta-adrenoceptors was decreased at 4 (-23%), 7(-20%) and 13(-39%) weeks in SHR compared with age-matched normotensive Wistar-Kyoto rats. In both strains beta-adrenoceptor density decreased significantly with age. alpha 1-Adrenoceptors exhibited complex, though slight, changes in SHR at different ages. The alpha/beta adrenoceptor density ratio was constantly increased in SHR (11.9 versus 7.6 at 7 weeks; 19.1 versus 15.8 at 13 weeks). These findings suggest that the abnormal contractility of SHR arteries may at least partially depend on changes at the adrenoceptor level. A loss of arterial beta-adrenoceptors early in the life of SHR can be an event leading to increased peripheral resistance and elevation of blood pressure.

Intracellular free [Ca2+] in circulating lymphocytes of spontaneously hypertensive rats.

In the light of previous reports suggesting a common abnormality of Ca handling in most tissues of hypertensive humans and rats, we applied a novel technique using the fluorescent probe Quin 2 for measurement of cytosolic free Ca2+ in lymphocytes of spontaneously hypertensive rats (SHR). (Ca2+)i is increased in SHR (122.1 +/- 7.4 nM) versus normotensive Wistar-Kyoto (WKY) control rats (81.1 +/- 6.3 nM) Membrane exchange, as challenged by varying the extracellular Ca concentration over a 10(5)-fold range proved to be relatively unimportant in regulating (Ca2+)i and did not significantly affect the difference between SHR and WKY. Catecholamines and ouabain had no appreciable effect on (Ca2+)i. The mechanisms of increased (Ca2+)i in SHR lymphocytes remain to be fully elucidated.