Biomedical subjects

B Kuch

Publications and source records attributed to B Kuch.

26 records · Page 2Linked to original sources

PubMed1984

Electrophysiologic and clinical effects of intravenous and oral encainide in accessory atrioventricular pathway.

The effect of intravenous and oral encainide was studied in 12 patients with an accessory atrioventricular pathway (AP). Eight patients had Wolff-Parkinson-White syndrome and 4 had a concealed AP. Electrophysiologic studies were performed before and after intravenous encainide, 1.0 to 1.5 mg/kg, and 4 weeks after oral encainide, 75 to 200 mg/day. Mean follow-up was 19 +/- 6 months. During sinus rhythm, intravenous and oral encainide significantly prolonged the AH and HV intervals. In patients with Wolff-Parkinson-White syndrome, after intravenous encainide, anterograde conduction over the AP was blocked in 3 patients, and the anterograde effective refractory period (ERP) of the AP was markedly increased in 3. Five of these 6 patients had a control value of the anterograde AP ERP of less than 270 ms. Anterograde AP block was maintained in 2 patients after oral encainide therapy. Retrograde AP block or marked increase of retrograde AP ERP was seen in 4 of 9 patients after intravenous encainide and in 2 of 7 after oral therapy. Encainide either prevented induction of circus movement tachycardia (intravenous, 4 of 11 patients; oral, 2 of 7 patients) or significantly prolonged tachycardia cycle length (intravenous, 7 of 11 patients; oral, 5 of 7 patients). During long-term follow-up of 9 patients, 6 patients had no recurrences of tachyarrhythmia after individual adjustment of encainide dosage. One patient had worsening of supraventricular tachycardia after intravenous encainide therapy and 4 patients complained of visual blurring; in 1 patient it was so severe that it required withdrawal of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1984

Multiple anterograde and retrograde AV nodal pathways: demonstration by multiple discontinuities in the AV nodal conduction curves and echo time intervals.

Programmed electrical cardiac stimulation was performed in a 40-year-old man with documented recurrent, sustained ventricular tachycardia which was refractory to standard medical therapy. Both the presence of several discontinuities in the AV nodal conduction curves during atrial and ventricular stimulation and the time intervals of the AV nodal echo phenomena suggested the presence of multiple AV nodal pathways. The results of this study are of interest in further increasing our understanding of the electrophysiologic behavior of the human AV node.

Adult↗

PubMed1983

[Electrophysiologic determination of 3 intranodal pathways using various time intervals].

Programmed electrical stimulation of the heart was performed in a 40-year-old man with documented recurrent, sustained ventricular tachycardia, which had proved refractory to standard medical therapy. In this patient, both the presence of several discontinuities in the atrioventricular (AV-)nodal conduction curves during atrial and ventricular stimulation and the varying time intervals of the AV-nodal echo phenomena suggested the presence of multiple AV-nodal pathways.

Adult↗

PubMed1980

New haemagglutinating fimbriae on Escherichia coli strains isolated from urine.

The haemagglutination patterns of 255 urinary Escherichia coli isolates were examined with human (A, Rh+), bovine, chicken and guinea pig erythrocytes in the presence and absence of D-mannose. The strains were divided into four groups according to their haemagglutination properties. About 40% of the isolated agglutinated human red blood cells in the presence of D-mannose. The haemagglutinin of one of these. E. coli O18a, c: K- strain No. 119 was stable, temperature sensitive, did not develop at 18 degrees C and could be isolated by the methods used for the production of fimbriae. Electron microscopy showed fimbriae on the surface of Strain No. 119. An absorbed serum prepared from a derivative cured of haemagglutinating property (No. 119/1) agglutinated all the strains haemagglutinating human erythrocytes in the presence of mannose, but none of those having other haemagglutination patterns. Serologically, the antigen of No. 119 is independent of the K88, K99, "987" and CF I factors and shows some relationship to CF II.

Animals↗

PubMed1980

alpha-Haemolysin: an additive virulence factor in Escherichia coli.

Haemolytic Escherichia coli, including human intestinal and extraintestinal as well as porcine enterotoxigenic and oedema disease isolates, and Proteus morganii strains were studied for their virulence. Hly+ wild type strains and Hly+ transconjugants were more virulent than Hly- derivatives as shown in mice and chick embryos. This enhanced virulence seems to be connected with the ability of diffusible alpha-haemolysin production because clones producing only non-diffusible, beta-haemolysin behaved as non-haemolytic ones. Haemorrhagic lung symptoms and haemoglobinuria were frequently observed after parenteral challenge of mice with alpha-haemolytic clones. Though the Hly- clone exhibited a high resistance against blood clearance, the number of circulating bacteria was significantly higher in the case of alpha-haemolytic clone. A causal connection between this phenomenon and the leukocidin activity of alpha-haemolysin is suggested.

Animals↗

PubMed1979

Shigella dysenteriae 1-like cytotoxic enterotoxins produced by Salmonella strains.

A Salmonella enteritidis strain produced a cytotoxin in addition to heat-labile (LT) and heat-stable (ST) enterotoxins. Two strains of serotypes Salmonella kapemba and Salmonella thompson were LT and ST negative, but exhibited a cytotoxic effect. After Sephadex G-100 fractionation of the crude S. enteritidis material, some high and low molecular fractions had both cytotonic and cytotoxic activities. Of the two other salmonellae, only some high molecular fractions contained the cytotoxic substance. Neutralization experiments revealed an antigenic relationship between the cytotoxins studied and Shigella dysenteriae 1 enterotoxin. On the basis of cross neutralization and other data, it seems that cytotoxic and LT-like characters are carried by the same molecule. In S. thompson and S. kapemba the LT fails to exert a biological effect, although it is antigenically related to the LT of Escherichia coli.

Animals↗

PubMed1979

Antitoxic immunity against the so-called lung toxin produced by Escherichia coli.

Cross neutralization test with antisera to crude haemolysins produced by some Escherichia coli strains indicated that there were no antigenic differences among the haemolysins tested. These crude preparates showed definite cytotoxicity which could also be cross neutralized by "antihaemolysin" sera. Neutralization experiments were performed in mouse lung test with homologous and heterologous anti-haemolysin sera, and with O and OK sera to the wild type strain and its toxic R mutant. The results showed that the immunity in the mouse lung model is antitoxic and antibacterial.

Animals↗

PubMed1978

Heat-stable enterotoxin produced by Shigella flexneri.

Filtrates and ultrasonics extracts of Shigella flexneri showed rapid permeability factor (PF) test and proved positive in suckling mice and ligated rabbit loop tests within 4 hr. Delayed PF was not detected and the rabbit loop dilatation test read after 18 to 24 hr, the mouse pad oedema reaction, the test for elongation effect of CHO cells were also negative. In the delayed PF test a strong "blanching" effect was observed. A filtrate of an Ent-Escherichia coli strain was positive only in the rapid PF test, while filtrate and ultrasonic extract prepared from the Ent+ E. coli strain showed a positive reaction in all tests for enterotoxins (ST and LT) including the rapid PF test. Ultrasonic extracts of a S. flexneri and an Ent- E. coli strain concentrated by freeze-drying were fractionated on Sephadex G-100 column. S. flexneri fractions of 60--70ml were positive for rapid PF, dilation capacity in suckling mice, and the blanching effect in the delayed PF test. No positive reaction was found in the delayed PF test and in CHO cell culture. Similar fractions of Ent- E. Coli carried substances responsible for the rapid PF and the blanching effect, but without suckling mice positivity.

Bacterial Toxins↗