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Biomedical subjects

K Urbanek

Publications and source records attributed to K Urbanek.

11 recordsLinked to original sources

The influence of antibiotic use on the occurrence of vancomycin-resistant enterococci.

BACKGROUND: Several studies have documented the influence of antibiotic selective pressure, mainly from the use of glycopeptides, third-generation cephalosporins, quinolones and lincosamides, on the frequency of vancomycin-resistant enterococci (VRE) occurrence in hospitals. The aim of this study was to evaluate the relationship between VRE occurrence and antibiotic use in the Department of Hemato-Oncology of the Teaching Hospital in Olomouc (DHO), Czech Republic, over a 6-year period under standard and unchanged hygienic and epidemiological conditions. METHODS: During the period of 1998-2003, Enterococcus sp. strains and VRE were isolated by standard methods from clinical samples taken from DHO in-patients. The frequency of VRE occurrence was expressed as the number of isolated strains per 100 bed-days/year. DHO antibiotic consumption data were processed according to the anatomical therapeutic chemical (ATC)/defined daily dose (DDD) system valid in 2003 and expressed in defined daily dose per 100 bed-days (DDD/100 bed-days) for each year of the period. RESULTS: Since 1998, the occurrence of VRE decreased significantly (from 0.28 to 0.17 VRE/100 bed-days in 2001). Between 2001 and 2003, a significant (P < 0.05) increase from 0.17 to 0.38 was observed. The antibiotic use decreased from 205.2 in 1998 to 161.0 DDD/100 bed-days in 1999 and after an increase in 2001 (to 181.8 DDD/100 bed-days) it remained relatively stable. A significant decrease was observed in third-generation cephalosporins and quinolones (from 29.5 to 9.7 and from 42.2 to 30.2 DDD/100 bed-days respectively) between 1998 and 1999. In 2002-2003, the use of third-generation cephalosporins and glycopeptides increased substantially (from 10.1 to 13.9 and from 11.3 to 15.2 DDD/100 bed-days respectively). The Pearson correlation value was significantly positive (P < 0.05) for VRE occurrence and the use of glycopeptides and third-generation cephalosporins. CONCLUSIONS: While our study confirms the effect of use of glycopeptides and third-generation cephalosporins on occurrence of VRE, no influence of quinolones and lincosamides over the 6-year period was shown.

Anti-Bacterial Agents↗

The occurrence of vancomycin-resistant enterococci in hematological patients in relation to antibiotic use.

Very important bacterial pathogens found in hematological patients at present are vancomycin-resistant enterococci (VRE). The main goal of this retrospective study was to assess their occurrence in relation to antibiotic use. We isolated 1918 Enterococcus strains, in toto, 138 (7.2%) of which proved to be VRE. The VRE most frequently identified were Enterococcus faecium VanA (77%) and Enterococcusfaecalis VanB (12%), mostly isolated from stools (57%). Comparing the development of the selection pressure of antibiotics and percentage of VRE in each period of observation, an effect of the administration of each antibiotic group on the occurrence of VRE can be presumed. A reduction in the administration of third generation cephalosporins, glycopeptides and fluoroquinolones and its replacement by penicillin antibiotics combined with inhibitors of bacterial beta-lactamases, contributed to the cessation of VRE incidence and succeeding reduced occurrence from 15.1% in the second half of 1998 to 6.1% in the first half of 2000.

Anti-Bacterial Agents↗

Evidence that human cardiac myocytes divide after myocardial infarction.

BACKGROUND: The scarring of the heart that results from myocardial infarction has been interpreted as evidence that the heart is composed of myocytes that are unable to divide. However, recent observations have provided evidence of proliferation of myocytes in the adult heart. Therefore, we studied the extent of mitosis among myocytes after myocardial infarction in humans. METHODS: Samples from the border of the infarct and from areas of the myocardium distant from the infarct were obtained from 13 patients who had died 4 to 12 days after infarction. Ten normal hearts were used as controls. Myocytes that had entered the cell cycle in preparation for cell division were measured by labeling of the nuclear antigen Ki-67, which is associated with cell division. The fraction of myocyte nuclei that were undergoing mitosis was determined, and the mitotic index (the ratio of the number of nuclei undergoing mitosis to the number not undergoing mitosis) was calculated. The presence of mitotic spindles, contractile rings, karyokinesis, and cytokinesis was also recorded. RESULTS: In the infarcted hearts, Ki-67 expression was detected in 4 percent of myocyte nuclei in the regions adjacent to the infarcts and in 1 percent of those in regions distant from the infarcts. The reentry of myocytes into the cell cycle resulted in mitotic indexes of 0.08 percent and 0.03 percent, respectively, in the zones adjacent to and distant from the infarcts. Events characteristic of cell division--the formation of the mitotic spindles, the formation of contractile rings, karyokinesis, and cytokinesis--were identified; these features demonstrated that there was myocyte proliferation after myocardial infarction. CONCLUSIONS: Our results challenge the dogma that the adult heart is a postmitotic organ and indicate that the regeneration of myocytes may be a critical component of the increase in muscle mass of the myocardium.

Antibodies, Monoclonal↗

Familial occurrence of cerebral arteriovenous malformation in sisters: case report and review of the literature.

Cerebral arteriovenous malformations (AVMs) are considered to be congenital disorders. However, their familial occurrence has so far been described in only 19 families in the literature. The authors report on two cases in one family and review the literature. A 45-year-old female subject with sudden onset of headache and vomiting due to a subarachnoid haemorrhage from a small AVM in the posterior part of the corpus callosum near the midline on the left side was studied. Irradiation of the AVM using Leksell's gamma knife led to its complete obliteration. Her older sister presented with temporal seizures at the age of 49 and later also with left hemiparesis, left hemihypaesthesia and dizziness - caused by a large AVM in the right temporal lobe. This AVM was treated by a combination of embolization and irradiation by the Leksell's gamma knife.

Corpus Callosum↗

Fos-like immunoreactivity in the brain stem following oral quinine stimulation in decerebrate rats.

The present study compared the distribution of Fos-like immunoreactivity (FLI) following intraoral stimulation with quinine monohydrochloride (QHCl) in awake intact rats to the pattern obtained in chronic supracollicular decerebrate (CD) rats. Because the behavioral rejection response to QHCl is evident in the CD rat, it was hypothesized that the pattern of FLI in the lower brain stem should be similar in both groups. Overall, the distribution of FLI in the brain stem was quite similar in both intact and CD groups, and QHCl stimulation increased FLI in the rostral (gustatory) nucleus of the solitary tract, the parabrachial nucleus (PBN), and the lateral reticular formation (RF) compared with an unstimulated control group. The CD group differed from the intact group, however, with a trend toward less FLI in the RF and a shift in the pattern of label away from the external subdivision of the PBN. CD rats also had increased FLI in the caudal nucleus of the solitary tract, with or without intraoral infusions. The distribution of QHCl-induced FLI in the brain stem of intact rats thus indicates both local sensorimotor processing as well as the influence of forebrain structures.

Administration, Oral↗

The role of adhesion molecules in allotransplanted islet cells rejection. Prolongation of islet cells allograft survival by antiadhesion treatment.

Insulin-dependent diabetes mellitus is an autoimmune disease caused by the selective destruction of islet beta cells. Allo or xeno transplantation of islet cells may establish a novel promising method of IDDM therapy. Understanding how lymphocytes recognize beta cell antigens is essential for the elucidation of the pathogenesis of islet dysfunction. Leukocyte adhesion to the target cells (endothelium, islets) via adhesion molecule pathways plays an important role in auto and allo/xeno antigen recognition and effector cytodestruction of target cells. However, the expression of these molecules on the endothelium and islet cells during the rejection process still remains unclear. There are some publications describing possible roles of these antigens in the response to the graft. The expression of some of adhesion molecules may contribute to a new method for the diagnosis of graft rejection and its therapy when adhesion blocking substances are used for the treatment.

Animals↗

[Radiological findings in pseudohypoparathyroidism].

Clinical and radiodiagnostic changes in pseudohypoparathyroidism are described in three members of one family. Radiodiagnostic changes consist of symmetric calcifications in basal ganglia, perivascular calcifications in soft tissues, and of alterations on the skeleton--Albright's osteodystrophy. Bone changes include a combination of osteoproductive and osteomalacic alterations. All these changes were observed in both brothers, their mother had only calcifications localised in upper and lower extremities.

Adult↗

Events related to microembolism during extracorporeal perfusion in man: effectiveness of in-line filtration recorded by ultrasound.

Microparticle generation during cardiopulmonary bypass was monitored continuously in 60 adult patients who underwent open-heart operations. Echo-ultrasound transducers of 5 mHz frequency were interposed in a bubble oxygenator arterial line proximal and distal to a commercially available micropore filter. Ordinary perfusion events correlated with an increase in embolic counts and were recorded graphically. Calculation of filter efficiency revealed that all filters decreased measurable embolic counts. Platelet and leukocyte determinations and plasma hemoglobin values were not altered beyond limits ordinarily encountered during perfusion without filters. No patient in any filter group experienced postoperative respiratory distress, diffuse pulmonary infiltrate, or low PaO2. The 20 mu woven nylon mesh filter and the Dacron-wool filter showed greater than 90% effectiveness in removing recorded particles. Insertion of a cardiotomy filter did not appreciably alter recorded embolic counts distal to the arterial line filter.

Blood Cell Count↗