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N-Trimethyl chitosan chloride (TMC; high molecular weight) and N-trimethyl chitosan oligosaccharide (TMO; low molecular weight) with different degrees of quaternisation were synthesised and evaluated for their absorption enhancing properties across mucosal epithelia. These quaternised chitosan derivatives (0.0625% w/v-0.5% w/v) showed a significant decrease in the transepithelial electrical resistance (TEER) of cultured rabbit tracheal epithelial cell monolayers as compared to the control. The degree of quaternisation and concentration of the compounds influenced the extent of the reduction in TEER. Higher degrees of quaternisation and an increase in the concentration of the compound were associated with a more pronounced reduction in the TEER. The TMO derivatives seemed to be more effective in lowering the TEER of tracheal cell monolayers as compared to the TMC polymers. Ciliary beat frequency (CBF) is the main defence mechanism of the respiratory tract and is therefore a useful parameter in evaluating the toxicity of nasally administered drugs and additives. The effect of the synthesised chitosan derivatives on the CBF of human nasal epithelial cells at pH 7.4 was determined by a method based on an analogue contrast enhancement technique. The TMO oligomers exhibited lower inhibition of the CBF of human nasal epithelial cells compared to that of the TMC polymers. It was proposed that this reduced effect on the CBF is due to the lower viscosity and molecular weight of TMO. However, no acute toxicity was found with any of the synthesised chitosan derivatives by means of the CBF tests conducted in this study.

An in vivo study under well-controlled conditions was undertaken to determine the effect of Haemaccel, a colloidal plasma volume expander, on normal haemostasis.Twenty patients, who were admitted for reduction mammaplasty, were included in this study. A standardised anaesthesia protocol was followed with all patients. Ten patients received 500 ml Haemaccel and 10 controls received 1,500 ml Ringer's lactate, a crystalloid solution. The solutions were administered intravenously during surgery over a period of 30-40 minutes. Standardised clinical observations and haematological tests were done at the following time intervals: after anaesthesia but before infusion of the plasma substitute, immediately after infusion was completed, and 20, 40 and 60 minutes after infusion.The blood pressure, pulse rate and O2 saturation levels were not influenced by the treatment given. Haemodilution was similar for the two patient groups. The platelet count and plasma levels of fibrinogen decreased in parallel with haemodilution. Thereafter the platelet count gradually increased to pre-infusion counts at 60 minutes. The prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT) and platelet aggregation in response to adenosine diphosphate (ADP) and collagen were not affected by the plasma volume expander given. Arachidonic acid-induced aggregation decreased significantly after Ringer's lactate was given but did not change when Haemaccel was given. The bleeding time was prolonged slightly, but not significantly, from 7.4 +/- 1.6 minutes to 8.8 +/- 1.6 minutes with Ringer's lactate and from 6.9 +/- 2.0 to 9.7 +/- 3.7 minutes with Haemaccel.We could not find any scientific evidence that Haemaccel affects haemostasis; neither does it increase bleeding relative to Ringer's lactate.

The aim of this study was to determine if recombinant (r-)hirudin, used as anticoagulant during hemodialysis, has favourable effects on blood-membrane interactions. The results were compared with that obtained when standard unfractionated heparin, the anticoagulant of choice, was used.Eleven patients with chronic renal failure and on maintenance hemodialysis were included in this open cross-over study. Heparin was administered according to the existing protocol in use at the Dialysis Unit during the first dialysis of the study (5,000 to 10,000 IU). r-Hirudin, 0.15 mg/kg, was given as a bolus at the start of the second dialysis, two days later. The effect of the anticoagulant on leukocyte and complement activation, thrombogenesis, release of platelet activating factor and pulmonary gas exchange was studied.In most cases after dialysis with heparin (8 of 11), but not with r-hirudin, macroscopically visible thrombi formed at the inlet of the artificial kidneys. Irrespective of the anticoagulant used, a transient leukopenia (neutropenia) developed ten minutes after dialysis was started. Heparin anticoagulation resulted in a significant increase in plasma levels of complement C3a at all time points, whereas with r-hirudin the increase was significant after only 30 and 240 min. The O2 saturation decreased significantly during the first two hours of dialysis with heparin. The partial O2 pressure decreased significantly during the first two hours of dialysis, irrespective of the anticoagulant used.We conclude that r-hirudin is superior to heparin with regard to inhibition of thrombus formation in the dialyzer during hemodialysis. Slight, but favourable effects on complement activation. O2 saturation and lung CO diffusing capacity were also found with r-hirudin.

Previous studies have established that chitosan hydrochloride and glutamate are potent absorption enhancers for large hydrophilic compounds across mucosal surfaces. However, these compounds lack solubility at neutral pH values. A partially quaternized and well-soluble derivative of chitosan, N-trimethyl chitosan chloride, was synthesized and the effects of this polymer on the transepithelial electrical resistance and permeability of intestinal epithelial cells were investigated in vitro.N-trimethyl chitosan chloride was synthesized by reductive methylation and characterized with NMR. The effect of this polymer (1.0-2.5% w/v) on the transepithelial electrical resistance of intestinal epithelial cells, using Caco-2 cell monolayers, was investigated. Permeation of the hydrophilic model compounds [14C]-mannitol (MW 182.2), FITC-Dextran (MW 4400) and the peptide drug buserelin (MW 1299.5), in the presence of N-trimethyl chitosan chloride (1.5-2.5% w/v), was followed for 3 hours. The transport process of the fluorescent marker, FITC-Dextran 4400, across the cell monolayers was visualised with confocal laser scanning microscopy. Viability of the cells was checked with the trypan blue exclusion technique.N-trimethyl chitosan chloride was found to be a perfectly water-soluble, partially quaternized (about 12%) derivative of chitosan. This polymer (1.5-2.5% w/v) caused a pronounced and immediate reduction (25-85%) in the transepithelial electrical resistance of Caco-2 cells. Large increases in the transport rate of [14C]-mannitol (32-60 fold), FITC-Dextran 4400 (167-373 fold) and buserelin (28-73 fold) were demonstrated. Confocal laser scanning microscopy confirmed that N-trimethyl chitosan chloride opens the tight junctions of intestinal epithelial cells to allow increased transport of hydrophilic compounds through the paracellular transport pathway. No deleterious effects to the cells could be demonstrated with trypan blue.The potential use of N-trimethyl chitosan chloride as an absorption enhancer across mucosal surfaces could be an important contribution towards the development of effective delivery systems for hydrophilic drugs.

The present study investigated the effects on self-concept of Rational-Emotive Therapy and auditory subliminal stimulation (separately and in combination) on 141 undergraduate students with self-concept problems. They were randomly assigned to one of four groups receiving either Rational-Emotive Therapy, subliminal stimulation, both, or a placebo treatment. Rational-Emotive Therapy significantly improved scores on all the dependent measures (cognition, self-concept, self-esteem, anxiety), except for behavior. Results for the subliminal stimulation group were similar to those of the placebo treatment except for a significant self-concept improvement and a decline in self-concept related irrational cognitions. The combined treatment yielded results similar to those of Rational-Emotive Therapy, with tentative indications of continued improvement in irrational cognitions and self-concept from posttest to follow-up.

In patients with arterial grafts, platelet consumption may be due either to platelet interaction with the graft, and/or concomitant platelet consumption in the rest of the arterial tree. This hypothesis was tested by quantifying the kinetics and platelet-graft interaction of indium-111-labelled platelets with double velour Dacron grafts in 13 patients with arterial insufficiency ascribed to atherosclerosis. Mean platelet lifespan (MPLS), 149 +/- 46 hours, was significantly shorter (P = 0.001) than normal. Labelled platelets were transiently deposited onto the graft surfaces. Peak 111In deposition on the grafts, 1.33 +/- 1.02% of injected labelled platelets, was reached at 70 +/- 33 hours. Thereafter the graft-platelet radioactivity decreased in parallel with platelet radioactivity in the circulation. There was no statistical correlation between MPLS and the factors known to be associated with graft platelet deposition: graft size; peak graft radioactivity; and the time to attain peak graft radioactivity. It is therefore concluded that in patients with arterial disease requiring graft implantation, the observed increased platelet consumption cannot only be ascribed to the interaction of platelets with the graft. Concomitant atherosclerosis is probably the important modifier of platelet consumption. The significant contribution of this factor to the shortening of the MPLS should be taken into account when assessing, by measuring platelet lifespan, the thrombogenicity of grafts.

The effect of the chelates oxine and tropolone, used to label platelets, on the kinetics of indium-111-(111In) labeled platelets was studied in twelve normal human subjects. Autologous platelets were labeled either in saline with 111In-oxine or in plasma with 111In-tropolone. Mean platelet lifespan was estimated by fitting the disappearance curve of platelets from the circulation to the multiple hit and other mathematical models. The in vivo distribution of platelets was quantitatively imaged with a scintillation camera. The in vivo recovery of 111In-oxine and 111In-tropolone did not differ, and the mean platelet lifespan was also similar (111In-oxine: 230 +/- 29 hr; 111In-tropolone: 226 +/- 13 hr). At equilibrium (90 min after reinjection of labeled platelets) and at the end of platelet lifespan, 111In-oxine and 111In-tropolone radioactivities in the spleen and liver were similar. These results demonstrate that the results of kinetics measured with 111In-oxine or 111In-tropolone do not differ significantly.

The present study was designed to investigate the possible effect of auditory subliminal stimulation on GSR. 38 undergraduate students were exposed subliminally to emotional words while GSR was monitored. The results confirmed the hypothesis that auditory subliminal stimulation would effect a significant increase in GSR.

To quantitatively characterize processes of platelet thrombus formation in vivo, the kinetics and incorporation into thrombus of autologous In-111-labeled platelets were compared in six patients with aortic aneurysms and in seven patients with prosthetic aortic grafts. Although platelet survival was comparably shortened in both patient groups (mean, 5.8 days), the maximum radioactivity (percentage of whole body radioactivity) as determined by gamma camera imaging was higher in the aneurysms than in the grafts (3.3% +/- 1.6% vs. 1.6% +/- 1.1%, p = 0.05). Maximum In-111 uptake was also attained more quickly in the aneurysm patients (2.3 +/- 0.8 days vs. 3.5 +/- 1.3 days; p = 0.07). The experimental platelet kinetic and imaging data were subsequently evaluated by compartmental analysis to estimate both normal and disease-related components of platelet destruction. This analysis indicated that deposited platelet radioactivity had a longer residence time on grafts (2.9 +/- 1.7 days vs. 1.4 +/- 0.9 days, p = 0.07) but accumulated at a faster rate in aneurysms (5.0% +/- 3.4% per day vs. 1.4% +/- 0.9% per day, p = 0.02). As determined by imaging, only a proportion of increased platelet destruction was specifically due to the aneurysms (55% +/- 38%) or grafts (17% +/- 11%, p = 0.03). This result indicates additional components of platelet destruction unrelated to graft and aneurysm thrombus formation which, in some graft patients, may reflect a greater severity of vascular disease or other mechanisms causing a preferential shortening of platelet survival. Thus, the analytical approach described may be a useful one for discriminating components of in vivo platelet utilization including platelet removal due to normal hemostatic and senescent mechanisms, localized thrombus formation, and more generalized vascular disease.

Mean platelet survival and turnover were simultaneously determined with autologous 111In-labeled platelets (111In-AP) and homologous 51Cr-labeled platelets (51Cr-HP) in ten patients with chronic immune thrombocytopenic purpura (ITP). In vivo redistribution of the 111In-AP was quantitated with a scintillation camera and computer-assisted image analysis. The patients were divided into two groups: those with splenic platelet sequestration (spleen-liver 111In activity ratio greater than 1.4), and those with diffuse sequestration in the reticuloendothelial system. The latter patients had more severe ITP reflected by pronounced thrombocytopenia, decreased platelet turnover, and prominent early hepatic platelet sequestration. Mean platelet life span estimated with 51Cr-HP was consistently shorter than that of 111In-AP. Platelet turnover determined with 51Cr-HP was thus over-estimated. The difference in results with the two isotope labels was apparently due to greater in vivo elution of 51Cr. Although the limitations of the techniques should be taken into account, these findings indicate that platelet turnover is not always normal or increased in ITP, but is low in severe disease. We suggest that this may be ascribed to damage to megakaryocytes by antiplatelet antibody. The physical characteristics in 111In clearly make this radionuclide superior to 51Cr for the study of platelet kinetics in ITP.