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Prevention of recurrent nasal polyposis in patients with detection of enterotoxi n producing Staphylococcus aureus strains
Schalek, Petr ; Petráš, Petr (advisor) ; Julák, Jaroslav (referee) ; Malina, Jiří (referee) ; Vokurka, Jan (referee)
Enterotoxins produced by Staphylococcus aureus can act as superantigens and thus, regardless of the antigenic specificity, influence the course of chronic rhinosinusitis with nasal polyps (NP). The aim of this study was to determine if antibiotic treatment administered after endoscopic sinus surgery (ESS) for NP can positively influence the course of the disease compared to placebo. After ESS, 23 patients which tested positive, in a perioperative culture, for SA strains producing enterotoxins A - E and TSST-1, were randomized into 2 groups. Group A (13 patients), which in addition to treatment with intranasal steroids and saline douches, received oral anti-staphylococcal antibiotics (according to the minimal inhibitory concentration) for 3 weeks. Group B (10 patients) received a placebo. Both groups were compared preoperatively, then again at 3 and 6 months after surgery using a symptom-specific score, an endoscopic score and the SNOT-22 quality of life questionnaire. Slightly better results were achieved in patients who received antibiotic therapy. However, the differences were not statistically significant. The biggest difference was seen on the endoscopic score 3 months after surgery. This difference clearly favored patients in group A. Regardless of post-operative treatment, approximately 30 % of...
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Virulence profiles of clinical isolates of enterohemorrhagic Escherichia coli and their relationship to disease severity
Marejková, Monika ; Petráš, Petr (advisor) ; Čížek, Alois (referee) ; Karpíšková, Renáta (referee)
CHARLES UNIVERSITY IN PRAGUE Third Faculty of Medicine Prague 2014 PhD Thesis Virulence profiles of clinical isolates of enterohemorrhagic Escherichia coli and their relationship to disease severity ing. Monika Marejková Summary Enterohemorrhagic Eschericha coli (EHEC) cause diarrhea and diarrhea-associated (D+) hemolytic-uremic syndrome (HUS) worldwide. D+ HUS develops as Shiga toxin (Stx)- mediated systemic complication of diarrhea mostly in children under 5 years and is the most common cause of acute renal failure in childhood. The aim of this study was to determine the role of EHEC in etiology of HUS and diarrhea in the Czech Republic, to develop rapid and reliable methods for EHEC detection and molecular subtyping, to analyze virulence gene profiles of the EHEC isolates and their correlation with the clinical outcome of the infection (i.e. uncomplicated diarrhea vs. HUS) and to gain insight into the epidemiology of EHEC infections. During 1998-2012 EHEC were isolated from stool samples of 70 % of pediatric patients with HUS. The isolates belonged to serotypes [fliC types] O157:H7/NM[fliCH7] (50 % were sorbitol-fermenting strains), O26:H11/NM[fliCH11], O55:NM[fliCH7], O111:NM[fliCH8], O145:H28[fliCH28], O172:NM [fliCH25], and Orough:NM[fliCH25]. EHEC O26 accounted for 41 % of all isolates. More than one...
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Resistance to macrolides, lincosamides and streptogramins in coagulase-negative staphylococci in ČR
Novotná, Gabriela ; Janata, Jiří (advisor) ; Petráš, Petr (referee) ; Sigler, Karel (referee)
VÝSLEDKY Analýza okolí genu msr(A) 45 součástí kompletního transpozonu Tn552 a s rekombinačním místem resbinR je identická až k místu rekombinace (resbinR site I). Druhá, v pozici JCSC1435 261884-2618311, je součástí sekvence transpozonu Tn5404. Kompletní transpozon Tn5404 je na vnějších okrajích ohraničen 7 bp dlouhou přímou repeticí (AGTAACT), jež vznikla zdvojením místa inzerce transpozonu (Obr. 5.3.), stejné inzerční místo pro Tn552 bylo pozorováno v chromozómu Entereococcus faecalis CH116 (146, 155). Shrnutí výsledků: Gen msr(A) byl u 41 izolátů lokalizován na chromozómu ve společném místě, pouze u dvou izolátů byl gen lokalizován na plazmidu. Oblast chromozomálně kódovaného genu msr(A) je u všech patnácti podrobněji studovaných izolátů (Tab. 5.1.) vysoce homologní s plazmidem πSh1, integrovaným v genomu S. haemolyticus JCSC1435 izolovaného v Japonsku (179). Uspořádání genů na tomto plazmidu je konzervovaným souborem jednotlivých genových motivů, jehož menší fragmenty byly odděleně popsány v několika dřívějších studiích. Rozdíly v msr(A) hybridizačních profilech jsou dány výhradně variabilitou v úseku kódujícím resolvasu Bin a rekombinasu Sin. Nalezli jsme pět různých typů uspořádání msr(A) oblastí, které se liší od JCSC1435 tímto: i) vložením části transpozonu Tn552 (typ KM50; 7,2kb msr(A)...
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Connectedness of high-frequency data
Petras, Petr ; Křehlík, Tomáš (advisor) ; Maršál, Aleš (referee)
This work combines discrete and continuous methods while modeling connect- edness of financial tick data. As discrete method we are using vector autore- gression. For continuous domain Hawkes process is used, which is special case of point process. We found out that financial assets are connected in non- symmetrical fashion. By using two methodologies we were able to model bet- ter how are the series connected. We confirmed existence of price leader in our three stock portfolio and modeled connectedness of jumps between stocks. As conclusion we state that both methods yields important results about price nature on the market and should be used together or at least with awareness of second approach. JEL Classification C32, G11, G14 Keywords Vector Autoregression, Hawkes process, High- frequency analysis, Connectedness Author's e-mail petr.petras@email.cz Supervisor's e-mail krehlik@utia.cas.cz
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Capital Market Hypotheses and Their Statistical Implications: A Comparative Study
Petras, Petr ; Krištoufek, Ladislav (advisor) ; Křehlík, Tomáš (referee)
In this bachelor thesis we focus on different Market Hypotheses. Specifically on Efficient Market Hypothesis, Fractal Market Hypothesis and Coherent Market Hypothesis. In the first part of the work we provide description of researched hypotheses and methods used for testing. In the second part of the work we run test on time series of share markets, gold markets and currency markets and test if our hypotheses can provide explanation about price changes on those markets. For Efficient Market Hypothesis we wonder if prices are following random walk (via augmented Dickey-Fuller test), if residuals are normally distributed (via Shapiro-Wilk and Jarque-Bera tests) and if residuals are uncorrelated (via Box-Pierce test). For Fractal Market Hypothesis we are trying to find value of Hurst exponent via Rescaled Range analysis. This exponent describes if time series are persistent or not. And for Coherent Market Hypothesis we develop simple method for testing if some time periods can yield above-average revenues, thanks to increased mean and decreased standard deviation. After that we find out what are consequences of short time series and different frequencies for obtaining data points and we learn that some hypotheses describes different time periods or lengths better and are not so good for different ones. Powered...
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Virulence profiles of clinical isolates of enterohemorrhagic Escherichia coli and their relationship to disease severity
Marejková, Monika ; Petráš, Petr (advisor) ; Čížek, Alois (referee) ; Karpíšková, Renáta (referee)
CHARLES UNIVERSITY IN PRAGUE Third Faculty of Medicine Prague 2014 PhD Thesis Virulence profiles of clinical isolates of enterohemorrhagic Escherichia coli and their relationship to disease severity ing. Monika Marejková Summary Enterohemorrhagic Eschericha coli (EHEC) cause diarrhea and diarrhea-associated (D+) hemolytic-uremic syndrome (HUS) worldwide. D+ HUS develops as Shiga toxin (Stx)- mediated systemic complication of diarrhea mostly in children under 5 years and is the most common cause of acute renal failure in childhood. The aim of this study was to determine the role of EHEC in etiology of HUS and diarrhea in the Czech Republic, to develop rapid and reliable methods for EHEC detection and molecular subtyping, to analyze virulence gene profiles of the EHEC isolates and their correlation with the clinical outcome of the infection (i.e. uncomplicated diarrhea vs. HUS) and to gain insight into the epidemiology of EHEC infections. During 1998-2012 EHEC were isolated from stool samples of 70 % of pediatric patients with HUS. The isolates belonged to serotypes [fliC types] O157:H7/NM[fliCH7] (50 % were sorbitol-fermenting strains), O26:H11/NM[fliCH11], O55:NM[fliCH7], O111:NM[fliCH8], O145:H28[fliCH28], O172:NM [fliCH25], and Orough:NM[fliCH25]. EHEC O26 accounted for 41 % of all isolates. More than one...
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Prevention of recurrent nasal polyposis in patients with detection of enterotoxi n producing Staphylococcus aureus strains
Schalek, Petr ; Petráš, Petr (advisor) ; Julák, Jaroslav (referee) ; Malina, Jiří (referee) ; Vokurka, Jan (referee)
Enterotoxins produced by Staphylococcus aureus can act as superantigens and thus, regardless of the antigenic specificity, influence the course of chronic rhinosinusitis with nasal polyps (NP). The aim of this study was to determine if antibiotic treatment administered after endoscopic sinus surgery (ESS) for NP can positively influence the course of the disease compared to placebo. After ESS, 23 patients which tested positive, in a perioperative culture, for SA strains producing enterotoxins A - E and TSST-1, were randomized into 2 groups. Group A (13 patients), which in addition to treatment with intranasal steroids and saline douches, received oral anti-staphylococcal antibiotics (according to the minimal inhibitory concentration) for 3 weeks. Group B (10 patients) received a placebo. Both groups were compared preoperatively, then again at 3 and 6 months after surgery using a symptom-specific score, an endoscopic score and the SNOT-22 quality of life questionnaire. Slightly better results were achieved in patients who received antibiotic therapy. However, the differences were not statistically significant. The biggest difference was seen on the endoscopic score 3 months after surgery. This difference clearly favored patients in group A. Regardless of post-operative treatment, approximately 30 % of...
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