Stress relaxation study of fillers for directly compressed tablets.

It is possible to assess viscoelastic properties of materials by means of the stress relaxation test. This method records the decrease in pressing power in a tablet at its constant height. The cited method was used to evaluate the time-dependent deformation for six various materials: microcrystalline cellulose, cellulose powder, hydroxypropyl methylcellulose, mannitol, lactose monohydrate, and hydrogen phosphate monohydrate. The decrease in pressing powering of a tablet during a 180 s period was described mathematically by the parameters of three exponential equations, where the whole course of the stress relaxation is divided into three individual processes (instant elastic deformation, retarded elastic deformation and permanent plastic deformation). Three values of the moduli of plasticity and elasticity were calculated for each compound. The values of elastic parameters ATi have a strong relationship with bulk density. The plastic parameters PTi represent particle tendency to form bonds. The values of plasticity in the third process PT3 ranged from 400 to 600 MPas. Mannitol had higher plasticity and lactose monohydrate on the contrary reduced plasticity. A linear relation exists between AT3 and PT3 for the third process. No similar interpretation of moduli calculated on the basis of three exponential equations has been realized yet.

[Transgastric and transrectal hybrid NOTES cholecystectomy--experimental study]. / Hybridní NOTES cholecystektomie transgastrickým a transrektálním prístupem v experimentu.

INTRODUCTION: Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a dynamically developing branch of miniinvasive surgery, whose aim is a minimazing abdominal wall injury. Many experimental studies describe the wide spectrum of the NOTES techniques in the animal model. The NOTES experiment begun in the porcine model for acquiring experience at the Surgical Departement in the University Hospital in Hradec Králové. MATERIAL AND METHODS: Hybrid NOTES cholecystectomy with transgastric and transrectal approaches in the porcine model were performed there. Eight animals were operated and were observed for 7 to 14 days after operations. A post-operative morbidity and mortality was found as well as a post-mortal examination for intraperitoneal complications. RESULTS: Three transgastric and five transrectal hybrid cholecystectomies were performed. One animal died immediately after operation due to an anaesthesiological complication. There were two transrectal operations that converted to open surgery due to massive rectum wall injury. Seven surviving animals were without complications in the post-operative period. No post-operative complication in post-mortal exploration were found, gastrotomy and colotomy were healed primarily, there were no signs for peritonitis. CONCLUSION: The experimental study showed the posibility of futher continuing development of the hybrid NOTES technique in the porcine model, also its safety, pitfalls and complications were presented.

[Intraoperative enteroscopy--personal experience from 1995 to 2002]. / Intraoperacní enteroskopie--vlastní zkusenosti z období 1995-2002.

Authors present their experience with the intraoperative enteroscopy method--an invasive technique of small bowel examination. It is performed under narcosis at an operating theatre (i.e. in co-operation with surgeon and anaesthesiologist). The endoscopy-performing physician becomes one of the members of the operating team. The advantage of the method is the possibility to examine of the whole small intestine and to solve immediately the pathological findings by endoscopic or surgical intervention. The examination is invasive and the correct indication is mandatory. Authors report their results of 18 intraoperative panendoscopies of small intestine.

[Role of peroperative coloscopy]. / Prínos peroperacní koloskopie.

The authors focus attention on the method of preoperative endoscopy which is useful in some operations of the digestive tract and evaluate retrospectively its contribution in their own department. They compare data on this method in the professional literature and consistent with them they recommend preoperative endoscopic examination in indicated cases as a safe, rapid and effective method for improving the standard of surgical care of patients and recommend this method in the algorithm of treatment.

[Endoscopic sclerotization as a method of treatment of esophageal varices]. / Endoskopická sklerotizace jako zpusob lécby jícnových varixu.

In the retrospective study of 23 patients the authors are rendering and evaluating their experiences in treating oesophageal varices by endoscopy sclerotization. On the basis of both proper experience and literature sources, they compare the efficiency of their approach with other conservative and surgical procedures. Their own modest experience is collated with the latest literature data. Far from estimating this method as an exclusive one in treating the portal hypertension complications, the authors believe it to be a considerable contribution to improve further destiny of the patients so treated.