High-speed liquid chromatography of sugar acids on anion-exchange resins

SUMMARY Mixtures of aldonic and aldaric acids are difficult to analyse. Aldonic acids can be separated in a satisfactory way on anion-exchange resins with a solution of sodium chloride as eluent. Under these circumstances, however, aldaric acids show unacceptably long elution times and peak broadening. The ability of aldaric acids to form non-adsorbable complexes with magnesium ions lowers their elution times, particularly of the low-molecular-weight acids, by up to 25 fold. This effect can be controlled by adjusting the magnesium ion concentration in the eluent. It is thus possible to achieve rapid, accurate analysis of mixtures of aldonic and aldaric acids by a proper choice of the magnesium and chloride ion concentrations in the eluent

β-blokkers en elektroconvulsietherapie: Een review

BACKGROUND: When patients with cardiovascular disorders undergo electroconvulsive therapy (ECT) they sometimes have to be treated for tachycardia and high blood pressure. AIM: To describe the effects of β-blockers on seizure duration and cardiovascular variables in patients undergoing ECT. METHOD: Search for studies in Medline, with the keywords 'beta-adrenergic blocking agents' and 'electroconvulsive therapy'. Only articles based on randomised placebo-controlled investigations were included. RESULTS: The search strategy produced 21 articles. These were assessed by all authors. Esmolol was the drug administered in most of the trials. Since seizure duration can influence the therapeutic effect of ECT it is advisable to use bilateral electrode placement in patients with cardiovascular risk factors and to administer esmolol prior to seizure induction. CONCLUSION: The beta-blocker of choice for use during ECT seems to be esmolol; it can shorten seizure duration, although the effect is probably dose-dependent. Esmolol is also the drug of choice in ECT sessions for patients without cardiovascular risk factors but who develop prolonged hypertension or tachycardia. A possible alternative is labetalol, but its longer half-life is a disadvantage, particularly if it is administered in a high dose. So far, experience with landiolol is limited, but its short half-life, greater cardioselectivity and higher potency mean that it could be a promising alternative

Coagulation and fibrinolysis in the first human auxiliary partial liver transplantation in rotterdam

Coagulation and fibrinolysis parameters were extensively monitored during and after a case of auxiliary partial liver transplantation (APLT). Preoperative coagulation tests demonstrated a severe liver dysfunction. Routine coagulation tests were prolonged and low levels of fibrinogen, antithrombin III (AT-III), and (α2-antiplasmin (α2-AP) were measured. Pro-urokinase (pro-UK), total Uk-antigen and plasminogen activator inhibitor (PAI) activity were increased (6.2; 5.4 ng/ml and 12.5 IU/ml, respectively). During transplantation no major changes in haemostasis were detected by either standard coagulation tests or thrombelastography and only a minimal increase of fibrinogen degradation products (0.6-1.0 μg/ml) was seen just before graft recirculation up till the end of the operation. PAI levels remained high during the operation and neither tissue-type plasminogen activator (t-PA) nor active urokinase (u-PA) were detectable. After APLT, graft function was reflected by normalisation of coagulation parameters and increase of AT-III and α2-AP to normal levels. Pro-Uk and PAI activity levels decreased after transplantation to normal values; a transient increase of t-PA activity (max. 1360 mIU/ml) was seen from the tenth to nineteenth day. It was demonstrated that a heterotopically placed partial liver allograft can provide synthesis of haemostasis factors and inhibitors and restore clearance which is adequate to reverse coagulopathy.</p

Coagulation and fibrinolysis in the first human auxiliary partial liver transplantation in rotterdam

Coagulation and fibrinolysis parameters were extensively monitored during and after a case of auxiliary partial liver transplantation (APLT). Preoperative coagulation tests demonstrated a severe liver dysfunction. Routine coagulation tests were prolonged and low levels of fibrinogen, antithrombin III (AT-III), and (α2-antiplasmin (α2-AP) were measured. Pro-urokinase (pro-UK), total Uk-antigen and plasminogen activator inhibitor (PAI) activity were increased (6.2; 5.4 ng/ml and 12.5 IU/ml, respectively). During transplantation no major changes in haemostasis were detected by either standard coagulation tests or thrombelastography and only a minimal increase of fibrinogen degradation products (0.6-1.0 μg/ml) was seen just before graft recirculation up till the end of the operation. PAI levels remained high during the operation and neither tissue-type plasminogen activator (t-PA) nor active urokinase (u-PA) were detectable. After APLT, graft function was reflected by normalisation of coagulation parameters and increase of AT-III and α2-AP to normal levels. Pro-Uk and PAI activity levels decreased after transplantation to normal values; a transient increase of t-PA activity (max. 1360 mIU/ml) was seen from the tenth to nineteenth day. It was demonstrated that a heterotopically placed partial liver allograft can provide synthesis of haemostasis factors and inhibitors and restore clearance which is adequate to reverse coagulopathy.</p

Fibrinolysis detected by thrombelastography in heterotopic, auxiliary liver transplantation:effect of tissue-type plasminogen activator

Orthotopic liver transplantation (OLT) is associated with haemostatic disturbances and a severe bleeding diathesis. Fibrinolytic activity may be increased, especially during the anhepatic phase and after graft-recirculation and this has been mentioned as a possible causative factor in the occurrence of uncontrollable bleeding. However, most studies were based on global assays and could not clarify the origin of the increased fibrinolysis. Recently, a programme of auxiliary liver transplantation (APLT) was started in Rotterdam. APLT is a surgically less traumatic procedure in which no anhepatic phase occurs. We examined fibrinolytic activity in the first 8 cases of APLT by thrombelastography (TEG), and also by measuring plasma levels of tissue-type plasminogen activator activity (t-PA-act) and antigen (t-PA-Ag) and its inhibition (PAI). Intraoperatively, in only two of the eight APLTs, a period of enhanced fibrinolytic activity was observed on TEG-recordings. This could be explained by an increase of t-PA-act (max. 8840 mIU/ml and 3760 mIU/ml) and t-PA-Ag (≥ 60 ng/ml). Both patients had signs of increased bleeding during these periods. Postoperatively in patients with a good graft function PAI levels decreased to normal values, whereas persistently elevated PAI levels (≥ 25 IU/ml) were found in cases with primary non-functioning liver grafts.</p

Fibrinolysis detected by thrombelastography in heterotopic, auxiliary liver transplantation:effect of tissue-type plasminogen activator

Orthotopic liver transplantation (OLT) is associated with haemostatic disturbances and a severe bleeding diathesis. Fibrinolytic activity may be increased, especially during the anhepatic phase and after graft-recirculation and this has been mentioned as a possible causative factor in the occurrence of uncontrollable bleeding. However, most studies were based on global assays and could not clarify the origin of the increased fibrinolysis. Recently, a programme of auxiliary liver transplantation (APLT) was started in Rotterdam. APLT is a surgically less traumatic procedure in which no anhepatic phase occurs. We examined fibrinolytic activity in the first 8 cases of APLT by thrombelastography (TEG), and also by measuring plasma levels of tissue-type plasminogen activator activity (t-PA-act) and antigen (t-PA-Ag) and its inhibition (PAI). Intraoperatively, in only two of the eight APLTs, a period of enhanced fibrinolytic activity was observed on TEG-recordings. This could be explained by an increase of t-PA-act (max. 8840 mIU/ml and 3760 mIU/ml) and t-PA-Ag (≥ 60 ng/ml). Both patients had signs of increased bleeding during these periods. Postoperatively in patients with a good graft function PAI levels decreased to normal values, whereas persistently elevated PAI levels (≥ 25 IU/ml) were found in cases with primary non-functioning liver grafts.</p