Etiology of thrombosis: relationship to blood platelets

The Nijdam voice prosthesis is an indwelling valveless voice prosthesis for postlaryngectomy voice rehabilitation. The in vitro aerodynamic characteristics are reported to be comparable to that of the low-resistance Groningen voice prosthesis. Owing to the design of the prosthesis the airflow resistance depends on the shaft length of the voice prosthesis in relation to the thickness of the tracheo-oesophageal wall. As tissue characteristics of the patient's oesophageal mucosa could also be of importance, an in vivo study was found necessary. To assess in vivo characteristics the following parameters were recorded in 10 patients: intratracheal pressure, intraoesophageal pressure and airflow during phonation. At an airflow of 0.15 1/sec the transdevice pressure loss varied from 0.5 up to 7 kPa (mean 3.9 kPa). With an artificial increase of the tracheo-oesophageal wall thickness, transdevice pressure losses up to 13 kPa were found. Significant interindividual as well as intraindividual differences were noted. The airflow resistance of the Nijdam voice prosthesis in relation to the thickness of the tracheo-oesophageal wall was compared with the airflow resistance reported for various other voice prostheses. The in vivo aerodynamic characteristics of the Nijdam voice prosthesis found in this study indicate the need to modify the present design in order to improve its airflow resistance and to eliminate the influence of the thickness and tissue characteristics of the tracheo-oesophageal wall.     

Interaction of the von Willebrand factor with platelets and thrombosis

The human von Willebrand factor (vWf) is a multimeric glycoprotein present in plasma, platelets, endothelial cells and subendothelium and synthesized in endothelial cells and megakaryocytes. vWf plays a pivotal role in the mechanisms of blood clotting and platelet thrombus formation; quantitative and qualitative abnormalities of vWf cause the most common congenital bleeding disorder in man, the von Willebrand disease. vWf stabilizes factor VIII and interacts with subendothelial components and with platelet membrane receptors. The multimeric structure of vWf provides an array of binding sites which allows multivalent interactions with its ligands, thus supporting the formation of stable platelet aggregates at the site of vascular injury, particularly under flow conditions characterized by high shear stress. In the last years, remarkable progress has been made toward understanding the structure of vWf protein and gene, and the elucidation of many structure-function relationships, which may result in improved therapeutic intervention for vWD patients, and in the development of effective strategies for antithrombotic therapy.     

Antimicrobial prophylaxis in orthopaedic surgery: the role of teicoplanin

Associational responses from 128 schizophrenic people and 120 healthy ones were collected. Four words with aggressive emotional shade were given as the stimuli. Semantic analysis of stimulus words was made, which made it possible to obtain a range of content categories. The collected material was analysed then according to them. Significant differences in five content categories were discovered. Basing on these differences we can infer that associational meaning at schizophrenic people is in some way varied. It was also possible to draw some conclusions concerning emotional life of the examined people.     

Thrombolytic and antiplatelet action of xanthinol nicotinate (Sadamin): possible mechanisms

Primiparous Holstein cows received recombinant bovine growth hormone (bGH), bovine growth hormone-releasing factor (bGRF), or no treatment from 118 to 181 +/- 1 d. Milk yield was significantly increased with no change in milk fat percentage or composition. The mRNA and protein abundance of the key lipogenic enzymes acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) were measured in the mammary gland and adipose tissue. We hypothesized that bGH and bGRF treatment would increase the mRNA and protein abundance of ACC and FAS in the mammary gland, with an associated decrease in adipose tissue. Analysis of ACC mRNA and protein abundance in the mammary gland revealed that there was no significant influence of either bGH or bGRF treatment. Analysis of FAS mRNA in mammary gland revealed that both bGH and bGRF significantly increased the abundance. However, quantitation of FAS protein in the mammary gland revealed that neither treatment resulted in increased abundance. In adipose tissue, the mRNA and protein abundance of both ACC and FAS were significantly reduced. The increased substrate required for increased milk fatty acid yield may be provided through redirection of nutrients to the mammary gland away from adipose tissue and through overall increased metabolism of the mammary gland.     

Motor cognition and its role in the phylogeny and ontogeny of action understanding.

Social life rests in large part on the capacity to understand the intentions behind the behavior of others. What are the origins of this capacity? How is one to construe its development in ontogenesis? By assuming that action understanding can be explained only in terms of the ability to read the minds of others--that is, to represent mental states--the traditional view claims that a sharp discontinuity occurs in both phylogeny and ontogeny. Over the last few years this view has been challenged by a number of ethological and psychological studies, as well as by several neurophysiological findings. In particular, the functional properties of the mirror neuron system and its direct matching mechanism indicate that action understanding may be primarily based on the motor cognition that underpins one's own capacity to act. This article aims to elaborate and motivate the pivotal role of such motor cognition, providing a biologically plausible and theoretically unitary account for the phylogeny and ontogeny of action understanding and also its impairment, as in the case of autistic spectrum disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aspirin and fraxiparine in the prevention of laser induced thrombosis in the presence of iodinated contrast media

The purpose of this study was to investigate the thromboembolic properties of ionic and nonionic contrast media in rats pretreated with aspirin and/or fraxiparine using an experimental model of laser induced thrombosis in the mesenteric microvessels of 17 groups of five male Wistar rats each. Two ionic (ioxaglate and diatrizoate) and two nonionic contrast media (iopamidol and iohexol), alone or associated with antithrombotic drugs (aspirin and/or fraxiparine) were studied. To evaluate the effects of these substances in this model, the number of laser beams needed to induce platelet thrombus formation, the number of emboli detached from the thrombus and the duration of embolization were quantified. Platelet aggregation induced by ADP, induced hemorrhagic time (IHT) and haemoglobin loss level were also determined. Both contrast media injected at 3 ml/kg caused a significant increase in the number of emboli and the duration of embolization (p<0.05). Pretreatment with aspirin and/or fraxiparine in the presence of ionic contrast media showed antithrombotic activities equal to those obtained when they were tested alone (p<0.05), while in the presence of nonionic contrast media, these drugs only neutralised the prothrombotic effects. There were no differences with the NaCl treated group (p>0.05). The ionic contrast media, and to a lesser extent the nonionic contrast medium: iohexol, inhibited platelet aggregation, while iopamidol behaved as an activator. The antithrombotic drugs tested in this study prevent the prothrombotic activities of contrast media therefore suggesting their use before radiographic procedures.     

The role of the extracorporeal detoxication in prophylaxis and treatment of respiratory disorders in patients with acute ileus

Hemosorption (HS) and plasmapheresis (PA) stimulate significantly the pulmonary metabolic functions due to their potent detoxicational effect. Arterial hypoxemia occurs simultaneously. The PA application contra HS causes more durable and stable detoxicational effect. It is mandatory in patients with an acute ileus to combine the HS conduction and repeated sessions of spontaneous respiration with end-expiratory additional pressure and to include fatty emulsions in complex of substitutional therapy while PA application.     

Limited proteolysis and reduction-carboxymethylation of rye seed chitinase-a: role of the chitin-binding domain in its chitinase action

By a limited proteolysis with thermolysin, rye seed chitinase-a (RSC-a) was separated into a N-terminal cysteine-rich chitin-binding (CB-) domain (48 residues) and a catalytic (Cat-) domain (254 residues). The hydrolytic activity of the isolated Cat-domain toward soluble glycolchitin, was similar to that of RSC-a, but that toward insoluble colloidal chitin was 28% of that of RSC-a. Five disulfide bonds in the CB-domain were reduced with 2-mercaptoethanol (2-ME) in the absence of denaturing agents by an "all-or-none" process, that is, once the disulfide bond between Cys15 and Cys42 in the CB-domain was cleaved, the remaining four disulfide bonds were reduced very easily. The reduced and carboxymethylated RSC-a completely lost the chitin-binding ability, but retained 50% of the hydrolytic activity toward colloidal chitin of RSC-a. From these results, it was shown that RSC-a consists of a CB-domain and a Cat-domain connected by a flexible linker, and it was suggested that the CB-domain increases the hydrolytic action of Cat-domain toward insoluble chitin derivatives by binding to them.     

Aspirin treatment of the low-dose-endotoxin-treated pregnant rat: pathophysiologic and immunohistologic aspects

In the present study, we evaluated the effect of low-dose aspirin (acetylsalicylic acid (ASA); 1.0 mg/kg daily) on blood pressure, albumin excretion, glomerular fibrinogen deposits, and glomerular (basement) membrane-bound adenosine diphosphatase (ecto-ADPase) activity, as well as on glomerular inflammation in pregnant rats infused with low-dose endotoxin (1.0 mg/kg). Rats (day 14 of pregnancy) were infused with endotoxin (ET rats) or saline (control rats) and received ASA in their drinking water. These rats were compared with non-ASA-treated rats. Blood pressure and albumin excretion were measured from day 15 to day 21, and glomerular fibrinogen and ecto-ADPase activity were measured at day 21. Glomerular inflammation was evaluated at various times after the start of the infusion. The results show that treatment with ASA had a significant beneficial effect on hypertension and inflammation induced by endotoxin in pregnant rats, whereas it reduced albumin excretion and glomerular fibrinogen deposits in some of the rats.     

Venous thrombosis after total hip replacement. Combined monitoring as a guide for prophylaxis and treatment

Monitoring of 140 patients after hip-replacement arthroplasty using both impedance plethysmography and 125I fibrinogen scanning of the lower extremities showed that half had no evidence of thrombosis, one-quarter had moderate or extensive thrombosis, and one-quarter had abnormal scans only. In the patients with only abnormal scans the process appeared to resolve spontaneously. The findings by impedance plethysmography therefore appeared to differentiate non-invasively between thromboses that would and would not resolve, and it is suggested that for some patients a monitoring regimen may be preferable to routine prophylaxis.     

Foot pump prophylaxis for deep venous thrombosis: the rate of effective usage in trauma patients

Only nine cases of primary multifocal leptomeningeal gliomatosis (PMLG) have been reported. We describe the first child with malignant features of PMLG who was diagnosed during life. The differential diagnosis based on imaging findings includes infectious and lymphoproliferative disorders.