Platelet and clotting activities after cold stress in diabetic patients

Platelet and clotting abnormalities have been described in diabetes, but little is known about their relationship to daily stresses. In order to evaluate whether states of abnormal carbohydrate metabolism modify the hemostatic response to stress, 12 subjects with type I diabetes mellitus, 9 with type II, 7 with impaired glucose tolerance and 10 healthy controls were exposed to a cold pressor test. Plasma concentrations of beta-thromboglobulin (index of platelet activation) and of fibrinopeptide A (index of thrombin formation) were measured before and 15 minutes after forearm immersion in melting ice. Basal levels of both proteins were significantly elevated (p less than 0.02) in the combined group of patients with diabetes and impaired glucose tolerance. While in healthy controls cold exposure failed to modify plasma concentration of either protein, obvious changes occurred in the diabetic and impaired glucose tolerance groups. In the combined patients group, beta-thromboglobulin levels decreased from 1.37 +/- 0.44 nmol/l to 1.03 +/- 0.39 (mean +/- SD, p less than 0.01), after the cold test, possibly in consequence of enhanced vascular permeability; while fibrinopeptide A levels increased from 1.52 +/- 1.03 nmol/l to 3.45 +/- 4.19 (p less than 0.02). The degree and pattern of abnormalities observed in basal as well as stimulated levels of fibrinopeptide A differed somewhat among the three groups of patients. These studies indicate that, in the basal state, patients with diabetes or simple carbohydrate intolerance are more susceptible than controls to platelet activation and that after stress thrombin formation can occur although some variability exists among and within groups of patients. The consequences of such increased thrombotic activity may have a bearing on the pathogenesis of large vessel disease, a complication common to diabetes and impaired glucose tolerance

Platelet and clotting activities after cold stress in diabetic patients

Platelet and clotting abnormalities have been described in diabetes, but little is known about their relationship to daily stresses. In order to evaluate whether states of abnormal carbohydrate metabolism modify the hemostatic response to stress, 12 subjects with type I diabetes mellitus, 9 with type II, 7 with impaired glucose tolerance and 10 healthy controls were exposed to a cold pressor test. Plasma concentrations of beta-thromboglobulin (index of platelet activation) and of fibrinopeptide A (index of thrombin formation) were measured before and 15 minutes after forearm immersion in melting ice. Basal levels of both proteins were significantly elevated (p less than 0.02) in the combined group of patients with diabetes and impaired glucose tolerance. While in healthy controls cold exposure failed to modify plasma concentration of either protein, obvious changes occurred in the diabetic and impaired glucose tolerance groups. In the combined patients group, beta-thromboglobulin levels decreased from 1.37 +/- 0.44 nmol/l to 1.03 +/- 0.39 (mean +/- SD, p less than 0.01), after the cold test, possibly in consequence of enhanced vascular permeability; while fibrinopeptide A levels increased from 1.52 +/- 1.03 nmol/l to 3.45 +/- 4.19 (p less than 0.02). The degree and pattern of abnormalities observed in basal as well as stimulated levels of fibrinopeptide A differed somewhat among the three groups of patients. These studies indicate that, in the basal state, patients with diabetes or simple carbohydrate intolerance are more susceptible than controls to platelet activation and that after stress thrombin formation can occur although some variability exists among and within groups of patients. The consequences of such increased thrombotic activity may have a bearing on the pathogenesis of large vessel disease, a complication common to diabetes and impaired glucose tolerance

Caratterizzazione delle proprietà del Regalrez 1126 e del Paraloid B72 nel consolidamento del legno

Questo lavoro è incentrato sullo studio dell’efficacia di due prodotti consolidanti applicati sia singolarmente che congiuntamente su due differenti specie lignee: l’abete rosso ed il pioppo bianco. Lo studio prosegue una ricerca già sviluppata e trattata in letteratura sulla sperimentazione delle caratteristiche consolidanti di due resine sintetiche e sulla loro possibile azione sinergica sul legno, potenzialmente determinata dai differenti livelli di penetrazione: il Paraloid B72, copolimero di durezza media a base di metilacrilato ed etilmetacrilato, e il Regalrez 1126, polimero a basso peso molecolare della famiglia degli idrocarburi saturi composto da monomeri di stirene idrogenato. I trattamenti sono stati effettuati su serie di provini delle due diverse specie lignee attraverso applicazioni sia con i consolidanti da soli che con un doppio trattamento che prevede una prima applicazione di Regalrez e successivamente di Paraloid. Sono state valutate le variazioni di porosità mediante porosimetria ad intrusione di mercurio e sono state effettuare misure delle variazioni dimensionali in seguito a cicli di invecchiamento accelerato gelo/disgelo. Parallelamente sono state effettuate misure colorimetriche e misure di spettroscopia infrarossa prima e dopo invecchiamento da radiazione solare al fine di verificare un’eventuale azione di rallentamento dei processi fotodegradativi del legno. I risultati ottenuti confermano la possibile differente localizzazione dei due prodotti, con un’evidente selezione funzionale, e mostrano come il doppio trattamento Regalrez- Paraloid rappresenti un significativo vantaggio in termini sia di resistenza meccanica che di resistenza alle variazioni dimensionali del legno. Non si osservano invece vantaggi del doppio trattamento nella resistenza ai processi fotossidavi e alle variazioni cromatiche