Sign-inverted response of aluminum work function to tangential strain.

We have investigated the response of the work function, W, of low-index aluminum surfaces to tangential strain by using first-principles calculations based on density functional theory. This response parameter is a central quantity in electrocapillary coupling of metal electrodes relating to the performance of porous metal actuators and surface stress based sensing devices. We find that Al surfaces exhibit a positive response for all orientations considered. By contrast, previous studies reported negative-valued response parameters for clean surfaces of several transition metals. We discuss separately the response of W to different types of strain and the impact of the strain on the Fermi energy and the surface dipole. We argue that the reason for the abnormal positive sign of the Al response parameter lies in its high valence electron density.

[Percutaneous vertebroplasty]. / Perkutánní vertebroplastiky.

Percutaneous vertebroplasty is a therapeutic, interventional radiologic procedure originally developed in France by Galibert, Deramond et al. (1987). The technique consists of the percutaneous puncture of the affected vertebral body, followed by injection of bone cement into a vertebral body for the relief of pain, and the strengthening of the bone. The procedure was used initially to treat aggressive hemangiomas, but it then was extended to the treatment of osteolytic metastases, multiple myeloma and osteoporotic compression fractures refractory to medical therapy. In this article we review the current techniques, indications for this procedure, preoperative and postoperative evaluations.

Extensive spinal epidural hematoma: a rare complication of aortic coarctation.

Development of collateral circulation belongs among the typical signs of aortic coarctation. Cerebral or spinal artery aneurysm formation with increased risk of subarachnoid hemorrhage represent the most common neurovascular complication of this disease. We report a case of a 20-year-old sportsman who developed acute non-traumatic paraplegia as a result of extensive spinal epidural hemorrhage from collateral vessels accompanying aortic coarctation which was unrecognized up to that time. To the best of our knowledge, acute spinal epidural hematoma as a complication of aortic coarctation has not been previously reported.

Value of Doppler sonography in revealing transjugular intrahepatic portosystemic shunt malfunction: a 5-year experience in 216 patients.

OBJECTIVE: The purpose of the study was to evaluate the long-term clinical efficacy of Doppler sonography in revealing failure of transjugular intrahepatic portosystemic shunts (TIPS). SUBJECTS AND METHODS: During a 5-year period, 1192 Doppler examinations were performed in 216 patients with TIPS. No regular follow-up shunt venography was performed. Doppler examinations were retrospectively compared with the results of shunt revisions. Sonograms with negative findings were compared with the patients' clinical status so that the number of false-negative sonographic findings leading to an episode of shunt failure (recurrence of gastrointestinal bleeding or ascites) could be ascertained. Sonographic parameters assessed included diameter, velocity, flow volume, and congestion index of the portal vein; and shunt velocities. RESULTS: Doppler sonography revealed shunt occlusion in 25 of 26 angiographically proven cases (sensitivity, 96%). The combination of velocity criteria (peak intrashunt velocity > or =250 cm/sec, maximum velocity in the portal third of the shunt < or =50 cm/sec, or maximum portal vein velocity less than or equal to two thirds of the baseline value) revealed shunt stenosis in 103 of 110 cases (sensitivity, 94%). Doppler sonography missed a significant shunt stenosis that led to an episode of gastrointestinal bleeding or ascites recurrence in only seven cases. The congestion index of the portal vein showed significant differences between patent and malfunctioning shunts (p < 0.001). CONCLUSION: Doppler sonography is an effective primary imaging method for long-term follow-up of patients with TIPS.

[CT-pneumocolon in the diagnosis of colorectal carcinoma]. / CT-pneumokolon v diagnostice kolorektálního karcinomu.

Accurate preoperative examination and early diagnosis of possible recurrence of the disease play an important role in successful therapy of colorectal carcinoma. At present, modifications of classical examination are being applied, too. In this paper the first experience in using the CT pneumocolon for diagnosing the colorectal cancer is presented. The method improves the diagnostic possibilities of the classical CT examination technique. It enables to image the morphology of the tumour in the air insufflated colon lumen, tumour infiltration outside intestinal wall, localization of organs in the presupposed operation field and possible infiltration of lymph-nodes or liver metastases. The examination has proved easy to be performed with minimal patient's discomfort.

[Transjugular intrahepatic portosystemic shunt (TIPS) in the treatment of symptomatic portal hypertension]. / Transjugulární intrahepatální portosystémový zkrat (TIPS) pri lécbe symptomatické portálni hypertenze.

BACKGROUND: A transjugular intrahepatic portosystemic shunt (TIPS) is the creation of a percutaneous portosystemic anastomosis which is used as an alternative method of surgical portosystemic shunts and endoscopic treatment in the therapy of complications of portal hypertension. The objective of the present work was to summarize experience with TIPS in 100 patients. METHODS AND RESULTS: In 1992-1995 the authors treated 100 patients with symptomatic portal hypertension by TIPS. To create the shunt in 84% patients a spiral Z stent was used, in the remainder a Wallstent. In 86% patients the indication for TIPS was haemorrhage associated with portal hypertension and in 14% refractory ascites. TIPS was implemented in 98% patients. The pressure in the portal vela was not reduced on average to 58% of the original value. Haemorrhage was not stopped in one of 7 patients. Haemorrhage from varices reappeared in 7% patients indicated on account of repeated haemorrhage and was always associated with the finding of chronic stenosis of the shunt. The mortality in conjunction with the procedure was 4%, the mortality within 30 days after operation was 8%. Uncontrollable encephalopathy developed in 3% of the patients. Primary patency of the shunt created by the spiral Z stent was 85% after 6 months, after 12 months 72% and thus does not differ from primary patency when Wallstents are used, as reported in the literature. CONCLUSIONS: TIPS is an effective method to reduce the pressure in the portal vein in portal hypertension. The main limiting factor of the method is stenosis of the shunt due to hyperplasia of the neointima. Stenoses of the shunt can be effectively dilated by percutaneous balloon angioplasty.

[Subacute thrombosis of the abdominal aorta with suprarenal involvement and successful treatment with pharmacomechanical fibrinolysis]. / Subakutní trombóza brisní aorty suprarenálne zasahující, úspesne lécená farmakomechanickou fibrinolýzou.

In a 43-year-old patient with Ebstein's anomaly and a history of acute myocardial infarction by means of duplex ultrasonography and aortography the diagnosis of thrombotic occlusion of the a aorta was established, starting above the insertion of the renal arteries and reaching as far as the bifurcation of the aorta and the common iliac arteries. In the clinical picture dominated complete anuria with uraemia and marked hyperkaliaemia as a result of ischaemic affection of the extremities due to thrombosis of the aorta; at the onset of hospitalization also left ventricular failure with hyperhydration and later also signs of the hyperviscous syndrome. The latter developed after repeated haemofiltrations which led to a rise of the originally high haemoglobin and haemotocrit values a result of a righ-left shunt in Ebstein's anomaly. After improvement of the clinical condition local fibrinolytic treatment of the aortal thrombosis with urokinase (total dose 2,160,000 u. administered within 24 hours) was provided. The thrombus with a total length of 13.5 cm was dissolved except for a residual portion of 10 mm located in the area of insertion of the right renal artery. After dissolution of the thrombus it proved possible to restore the blood flow into the left kidney a and lower extremities, but not into the right kidney because of the residual thrombus. Seventy-two hours after terminated fibrinolysis - and after 31 days of anuria - the diuresis was restored and after a polyuric stage normalization of mineral, urea levels was restored and the creatinine value was slightly above the upper normal range. Concurrently with fibrinolytic therapy angioplasty of the aorta was carried out and a stent was placed on the left iliac artery. The clinical condition of the patient was improving, the patient started to mount stairs. Death occurred suddenly and the cause was cardiac failure due to very serious congenital heart disease.

Posterior fossa duraplasty in children: remarks on surgery and clinical and CT follow-up.

A series of 314 posterior fossa duraplasties in children were performed at the Department of Neurosurgery, Hradec Králové, over the past 33 years. Computed tomographic (CT) imaging was used to compare the healing of various kinds of collagenic dural substitutes--allogeneic fascia lata, allogeneic dura mater and xenogeneic pericardium. Early (8 days to 3 months following surgery) and late (1-18 years following surgery) axial CT scans with sagittal reconstruction for duraplasty in 55 children were evaluated. In early postoperative CT scans, epidural collections of cerebrospinal fluid, sanguinolent liquid or haematoma and/or pseudocysts or pseudomeningoceles appeared. In late CT follow-up, calcifications and ossifications in the "suboccipital coverings complex" (SCC) gradually developed and pseudocysts or pseudomeningoceles rarely persisted. It is concluded, on the basis of perioperative, clinical, and CT examinations, that posterior fossa duraplasties in children formed an important anatomical barrier and regardless of the type of graft had a favourable outcome; CT was shown to be a suitable method for the demonstration of dural grafts at the site of craniectomies.

[Lymph node enlargement in hairy cell leukemia and problems with significant abdominal lymphadenopathy]. / Zvetsení uzlin u leukemie s vlasatými bunkami a problematika výrazné abdominální lymfadenopatie.

Enlargement of nodes in leukaemia with hairy cells (LVB) during the initial examination is rarely encountered. In the final stage of the disease it was found in six of our ten patients. A special situation is marked enlargement of retroperitoneal nodes observed in two patients. In one of them the nodes diminished after irradiation, in the second patient irradiation was not possible because of severe pancytopenia. Treatment with alpha-interferon failed previously in this patient. The question remains whether marked enlargement of the abdominal nodes is part of the picture of the disease or whether it is the manifestation of transformation of the disease into a more acute type. The authors recommend examination of the abdominal nodes by means of computed tomography (CT) already during the initial examination and during the subsequent course of the disease, in particular when there are signs of relapse.

[Transjugular intrahepatic portosystemic shunt]. / Transjugulární intrahepatický portosystémový zkrat.

The transjugular intrahepatic portosystemic shunt (TIPS) is a relatively new method of creating a portosystemic shunt using a needle, angioplasty balloon catheters and expandable metallic stents. During a 6-month period, the authors have performed TIPS, using the spiral Z-stent--another modification of the Gianturco-Rósch stent--in 13 patients with portal hypertension. The procedure was technically successful in all patients. Portal pressure decreased by 6 mmHg in one group of patients with 9-10 mm stents, and by 12 mmHg in another group using 12 mm stents. Control of variceal bleeding or resolution of refractory ascites was evident in 11 of the 13 patients.

[Ultrasound anatomy of the liver]. / Ultrazvuková anatomie jater.

The authors review the modern concept of liver anatomy, related to the needs of surgeons in segmental resections. Important anatomical structures are described participating in division of the liver into four basic segments. The ultrasound anatomy of portal system, hepatic veins, hepatic fissures and liver hilus are dealt with in detail. Criteria for perfect examination of the liver by ultrasound are defined and representability of key anatomical structure under optimal conditions is analyzed in a group of 100 patients. The only non-constantly represented structure was fissura interlobaris (44%). Hepatic veins proved to be the most variable structures (17%). The results show that segmental anatomy of the liver may be very well represented by ultrasound. The authors discuss the importance of perfect knowledge of anatomy for quality examination.

[Treatment of pyogenic liver abscesses using percutaneous transparietal drainage]. / Lécení jaterních pyogenních abscesu perkutánní transparietální drenází.

Authors present their own experience with the method of external transparietal drainage of pyogenic hepatic abscesses. It is both effective and available method with minimum complications if performed in time. Mortality rate is much lower than in surgical drainage. Percutaneous drainage of hepatic abscesses depends on the possibility of their diagnostics by means of ultrasonography or computer tomography and access to special instruments.

Dose- and sex-independent disposition of ciprofloxacin.

Serum concentrations and urinary excretion of ciprofloxacin were studied in female and male volunteers following a single oral administration of 100 mg, 250 mg, 500 mg or 1000 mg. Serum and urine concentrations increased proportionally to the increasing dose administered but independently of sex. Twenty-five percent of the administered dose was excreted in the urine as unmetabolized ciprofloxacin within the first 24 hours after oral administration. Renal clearance averaged 5 ml/min X kg.