Deuterium isotope effects on the interaction between hyperbranched polyethylene imine and an anionic surfactant.

Solvent isotope effects on the interaction between the hyperbranched cationic polyelectrolyte, polyethylene imine (PEI), and the anionic surfactant sodium dodecyl sulfate (SDS) were investigated using potentiometric titration and eletrophoretic mobility measurements. In the basic pH range, a significantly higher fraction of the amine groups was found to be protonated when the PEI was dissolved in D2O compared to H2O at the same pH/pD. The difference in polymer charge in the two solvents decreases gradually with decreasing pH, and it completely diminishes at around pH = 4. Electrophoretic mobility measurements of PEI/SDS complexes at different pH values correlated very well with these observations. At pH/pD approximately 9 a much higher mobility of the PEI/SDS complexes was found in D2O than in H2O at low surfactant concentrations, and the charge neutralization point shifted to a considerably larger surfactant concentration in heavy water. These results can be explained by the significantly higher charge density of the PEI in D2O compared to H2O. However, at the natural pH/pD as well as at pH = 4 and pD = 4 conditions the PEI molecules have roughly equal charge densities, which result in very similar charged characteristics (mobilities) of the PEI/SDS complexes as well as the same charge neutralization SDS concentration. It can be concluded that extreme care must be taken in the general analysis of those experiments in which weak polyelectrolyte/surfactant aggregates are investigated in heavy water, and then these observations are correlated with structures of the same system in water.

[Using the radial artery in myocardial revascularization]. / Az arteria radialis alkalmazása a szívizom revascularisatiójában.

Between March 1996 and April 1998, 10 patients underwent myocardial revascularization using radial artery grafts. The age ranged between 59-81 (mean 67.7) years. The mean left ventricular ejection fraction was found to be 0.53 (range 0.45-0.62). A mean of 3.2 distal anastomoses per patient were performed. There was no operative mortality and no perioperative myocardial infraction was observed. No ischaemia of the hand was noticed. At a mean follow-up of 16.6 months (range 3-27) all patients are alive and free of symptoms. Only one patient had angina at bicycle ergometer test. The precise and atraumatic harvesting of radial artery and use of calcium antagonists prevent vasospasm and early graft occlusion on the short term. To assess the late results longer follow-up is necessary.

[Postoperative depression after open heart surgery]. / Posztoperatív depresszió nyitott szívmútétek után.

Rehabilitation of the patients following open heart surgery is strongly influenced by the psychological conditions. Depression plays a crucial negative role in this process. Depression score was measured in patients taking part in the rehabilitation course of our institute last year (1998), 6 weeks after discharge from the hospital. Unfortunately preoperative score was not done. Beck Depression Inventory (BI) test was used. Following factors were investigated: age, gender, cross clamp and bypass time, type of anaesthesia (propofol, isoflurane or midazolam, all combined with fentanyl), ICU stay, hospital stay, hypotension, cardioversion during hospital stay and neurological disorders. Statistical analyses were performed with forward stepwise regression and ANOVA tests. 74 patients were investigated. BI score under 10 points is considered to be normal. Depression scores were significantly affected by the gender (females: r: 0.85, p = 0.005), and the ICU stay (r: 0.76, p = 0.007). Type of anaesthesia, age, hospital stay, and neurological disorders did not affected the depression score. Our results indicate, that females and patients with longer ICU stay require special attention during the perioperative period in psychological respect.

[Clinical use of transesophageal echocardiography]. / A transoesophagealis echocardiographia klinikai alkalmazása.

Transoesophageal echocardiography (TE) presents a new window in echocardiography. Experience obtained in the first 70 TE studies performed in 66 patients is reported. The patients' age ranged between 15 and 75 years, there were 36 females and 30 males. Sixty studies were done in awake patients and 10 studies in anesthetized or intubated patients. TE indications included suspected mitral prosthetic valve dysfunction: 20, tumor or thrombus: 11, search for source of embolism: 10, infective endocarditis: 5, congenital heart disease: 8, intraoperative decision-making: 7, acute postoperative hypotension: 3, suspected aortic dissection: 3 and others. There was no unsuccessful intubation or complication. The most important results: the differentiation of left atrial tumor and thrombus by the presence or absence of spontaneous echocontrast, the role of TE in the intraoperative and early postoperative decision making and the diagnosis in rare clinical situations (multiplex myxoma; tricuspid prosthetic valvular regurgitation caused by pacemaker electrode dislocation). It is concluded that TE is a unique diagnostic technique which provides invaluable clinical informations and facilitates therapeutic decision making. It is a safe procedure both in awake and anesthetized patients therefore in certain indications it should supplement standard echocardiographic technique in routine clinical practice.

[Long-term results of surgical treatment of cardiac myxomas]. / A cardialis myxomák sebészi kezelésének késöi eredményei.

We have reviewed our clinical experience in the diagnosis and management of 50 cases of cardiac myxoma seen over a 20 year period, 1974 to 1994. There were 17 males and 33 females, their ages ranged from 16 to 81 years (mean 55.2 years). Echocardiography confirmed the diagnosis in all patients. The location of myxomas was as follows: left atrial alone in 42 patients, right atrial alone in 3, right ventricular alone in 1, left + right atrial in 2, left + right atrial + right ventricular in 1, and left atrial eft ventricular in 1. Nineteen patients were operated on within 48 hours following the diagnosis. All tumors were successfully removed with the aid of cardiopulmonary bypass. The hospital mortality rate was 10%. Excision of the tumor resulted in marked symptomatic improvement. There was one late death. The current survivors are asymptomatic at a mean follow-up of 76,4 months (range 1-241 months). Echocardiographic studies were performed in all survivors and no recurrences have been observed. We conclude that excision of cardiac myxomas is curative and long-term survival is excellent. Radical tumor excision may prevent recurrence.

Bottle-brush polymers: adsorption at surfaces and interactions with surfactants.

Solution and adsorption properties of both charged and uncharged bottle-brush polymers have been investigated. The solution conformation and interactions in solution have been investigated by small-angle scattering techniques. The association of the bottle-brush polymers with anionic surfactants has also been studied. Surfactant binding isotherm measurements, NMR, surface tension measurements, as well as SAXS, SANS and light scattering techniques were utilized for understanding the association behaviour in bulk solutions. The adsorption of the bottle-brush polymers onto oppositely charged surfaces has been explored using a battery of techniques, including reflectometry, ellipsometry, quartz crystal microbalance, and neutron reflectivity. The combination of these techniques allowed determination of adsorbed mass, layer thickness, water content, and structural changes occurring during layer formation. The adsorption onto mica was found to be very different to that on silica, and an explanation for this was sought by employing a lattice mean-field theory. The model was able to reproduce a number of salient experimental features characterizing the adsorption of the bottle-brush polymers over a wide range of compositions, spanning from uncharged bottle-brushes to linear polyelectrolytes. This allowed us to shed light on the importance of electrostatic surface properties and non-electrostatic surface-polymer affinity for the adsorption. The interactions between bottle-brush polymers and anionic surfactants in adsorbed layers have also been elucidated using ellipsometry, neutron reflectivity and surface force measurements.

Complexes of surfactants with oppositely charged polymers at surfaces and in bulk.

Addition of surfactants to aqueous solutions of polyelectrolytes carrying an opposite charge causes the spontaneous formation of complexes in the bulk phase in certain concentration ranges. Under some conditions, compact monodisperse multichain complexes are obtained in the bulk. The size of these complexes depends on the mixing procedure and it can be varied in a controlled way from nanometers up to micrometers. The complexes exhibit microstructures analogous to those of the precipitates formed at higher concentrations. In other cases, however, the bulk complexes are large, soft and polydisperse. In most cases, the dispersions are only kinetically stable and exhibit pronounced non-equilibrium features. Association at air-water interfaces readily occurs, even at very small concentrations. When the surfactant concentration is small, the surface complexes are usually made of a surfactant monolayer to which the polymer binds and adsorbs in a flat-like configuration. However, under some conditions, thicker layers can be found, with bulk complexes sticking to the surface. The association at solid-water interfaces is more complex and depends on the specific interactions between surfactants, polymers and the surface. However, the behaviour can be understood if distinctions between hydrophilic surfaces and hydrophobic surfaces are made. Note that the behaviour at air-water interfaces is closer to that of hydrophobic than that of hydrophilic solid surfaces. The relation between bulk and surface complexation will be discussed in this review. The emphasis will be given to the results obtained by the teams of the EC-funded Marie Curie RTN "SOCON".

Surgical experience with thrombotic and fibrotic forms of non-tropical eosinophilic endomyocardial disease.

Surgical treatment in 8 cases of non-tropical eosinophilic endomyocardial diseases with (4 patients) and without (4 patients) eosinophilia is reported. Follow-up results (1 to 4 years) in the 6 survivors, including hemodynamic re-study, were excellent even in patients operated on in the thrombotic stage (3) or with hypereosinophilia (2), or with dominant right ventricular involvement (3). Two-dimensional echocardiography gave the correct description of the pathologic stage and ventricular involvement in 6 of the 8 cases before catheterization.

Comparative study of cefamandole versus cephalothin as antibiotic prophylaxis for open heart surgery.

Cefamandole nafate and cephalothin sodium were administered as prophylaxis in a randomized, prospective study to 80 consecutive patients undergoing open heart surgery. The two groups matched well in age, sex, and type of operation. Postoperative infection developed in 2 of 40 patients (5%) in the cefamandole-treated group and in 11 of 40 patients (27.5%) in the cephalothin-treated group (p less than 0.01). The two patients in the former group had respiratory tract infections. There were no instance of endocarditis, mediastinitis or bacteraemia in any of the two groups. Both antibiotics were well tolerated with no adverse reactions. Cefamandole appears to be an effective and preferable prophylactic antibiotic for use during cardiac surgery.

Prophylactic administration of histamine1 and histamine2 receptor blockers in the prevention of protamine-related haemodynamic effects.

We studied the effects of the prophylactic administration of histamine1 and histamine2 receptor blockers on haemodynamic changes, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MBP), central venous pressure (CVP), and heart rate (HR, beats.min-1) before and after the administration of protamine in two groups of patients having coronary artery bypass graft surgery. Group I patients received no histamine blockers, whereas patients in Group II were treated prophylactically with both H1 (diphenhydramine) and H2 (cimetidine) receptor blockers. The mean SBP, DBP, MBP, CVP, and HR before (and after) administration of protamine in group I patients were 114 +/- 16 (90 +/- 16) mmHg, 64 +/- 11 (51 +/- 8) mmHg, 81 +/- 11 (65 +/- 10) mmHg, 10 +/- 3 (11 +/- 7) mmHg, and 92 +/- 10 (87 +/- 13) before (and after) protamine administration. Group II patients had mean SBP, DBP, MBP, CVP, and HR of 113 +/- 19 (113 +/- 17) mmHg, 61 +/- 12 (62 +/- 11) mmHg, 79 +/- 15 (80 +/- 13) mmHg, 9 +/- 3 (9 +/- 2) mmHg, and 88 +/- 6 (86 +/- 4) before (and after) protamine administration. Our data show that only in Group I patients who did not receive histamine receptor blockers, were there significant haemodynamic changes following protamine administration (P less than 0.05). We conclude that the prophylactic administration of histamine receptor blockers prevents some of the adverse haemodynamic effects associated with protamine administration.

The effect of premarin on blood loss attending open heart surgery.

Premarin was administered prophylactically to every other patient in a series of 148 consecutive cases of open intracardiac surgery. Of these, 132 patients were matched to analyse the results of Premarin administration and postoperative blood loss. There were 67 patients who were given Premarin and 65 who did not receive this drug; both groups were identical in respect of age and sex. Matching was undertaken according to history of previous cardiac operations and anticoagulation, type of valve surgery or repair of congenital anomaly, duration of perfusion, platelet count and the use of fresh blood and epsilon-aminocaproic acid in the postoperative period. The prophylactic use of Premarin was not associated with a reduction in postoperative bleeding.