P Horváth

Semmelweis University, Budapeŝto, Budapest, Hungary

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Publications (7)11.44 Total impact

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    ABSTRACT: The purpose of this study was to investigate the impact of fluoroquinolone resistance on the existence and dynamic of MRSA clones. Resistance to ciprofloxacin was induced in strains of community-acquired (CA) MRSA from various sequence types and the fitness cost suffered by mutant derivatives measured in a propagation assay. In addition, the fitness of fluoroquinolone resistant health care-associated (HA) MRSA isolates from major clones prevalent in Hungary were compared with each other and with those of the CA-MRSA derivatives. The genetic background of fluoroquinolone resistance and fitness cost in CA-MRSA was investigated. The fitness cost observed in the CA-MRSA derivatives proved diverse; the derivatives of the ST30-MRSA-IV strain suffered significantly greater fitness cost than those of the ST8-MRSA-IV and ST80-MRSA-IV isolates. Strains from the New York-Japan (ST5-MRSA-II), South German (ST228-MRSA-I) and EMRSA-15 (ST22-MRSA-IV) HA-MRSA clones proved more viable than CA-MRSA derivatives with similar MIC values to ciprofloxacin and HA-MRSA strains from the Hungarian/Brazilian clone (ST239-MRSA-III). Our strains from the New York-Japan, South-German and EMRSA-15 clones seem to have a competitive edge over the tested CA-MRSA isolates in the health care setting. The greater fitness observed in our New York-Japan and South-German strains could account for the replacement by them of the Hungarian/Brazilian clone in Hungary about ten years ago. Alterations in relevant genes were detected. The Ser80 → Phe mutation in the grlA gene may have seriously compromised viability. Surprisingly silent nucleotide substitutions in the grlB gene seemed to impact fitness in derivatives of the ST30-MRSA-IV isolate.
    European Journal of Clinical Microbiology 01/2012; 31(8):2029-36. DOI:10.1007/s10096-011-1536-z · 2.67 Impact Factor
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    ABSTRACT: In the authors' earlier study the relative aerobic power of Hungarian top-level male water polo players was found to be smaller than that of other top-level athletes, while their echocardiographic parameters proved to be the most characteristic of the athlete's heart. In the present investigation echocardiographic and spiroergometric data of female top-level water polo players were compared to those of other female elite athletes and of healthy, non-athletic subjects. Relative aerobic power in the water polo players was lower than in endurance athletes. Mean resting heart rates were the slowest in the water polo players and endurance athletes. Morphologic indicators of the heart (body size related left ventricular wall thickness and muscle mass) were the highest in the water polo players, endurance and power athletes. In respect of diastolic functions (diastolic early and late peak transmitral flow velocities) no difference was seen between the respective groups.These results indicate that, similarly to the males, top-level water polo training is associated with the dimensional parameters of the heart rather than with relative aerobic power. For checking the physical condition of female water polo players spiroergometric tests seem to be less appropriate than swim-tests with heart rate recovery studies such as the ones used in the males.
    Acta Physiologica Hungarica 12/2009; 96(4):449-57. DOI:10.1556/APhysiol.96.2009.4.5 · 0.75 Impact Factor
  • M Füzi · P Horváth
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    ABSTRACT: Until recently the etiology of bovine spongiform encephalopathy (BSE) was considered uniform. The infectious agent was thought to be a single strain of prion (posttranslationally altered form of normal prion protein: PrPSc) retaining its biochemical and biological characteristics during interspecies transmission. However, alternate PrPSc signatures through large-scale screening have recently been detected. In addition, genetic alterations governing susceptibility to prion infection and a mutation (E211K) capable of eliciting spontaneous BSE have been demonstrated. Thus, the spectrum of BSEs have broadened and three PrPSc variants (BSE-C, BSE-H and BSE-L) are now defined. Moreover, a new condition resembling BSE, idiopathic brainstem neuronal chromatolysis (IBNC), has been described that may also turn out to be a prion disease. Since one of the new BSE variants, L-type BSE, proved highly pathogenic detection and further characterization of the new conditions are essential.
    Acta Microbiologica et Immunologica Hungarica 04/2009; 56(1):53-60. DOI:10.1556/AMicr.56.2009.1.3 · 0.78 Impact Factor
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    ABSTRACT: antibacterial, fluoroquinolone, permanent bond, polyethylene glycol, telechelic
    The Journal of Antibiotics 02/2009; 62(2):113-6. DOI:10.1038/ja.2008.26 · 2.04 Impact Factor
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    ABSTRACT: The formation of supramolecular polymeric aggregates with a molecular mass of 100 kDa in a nonaqueous solution from a telechelic dimer of isopropylidene guanosine in the presence of K+ ions is reported. The possible structure of macromonomers resulting from the development of G(4) quartets was deduced from DOSY NMR, circular dichroism spectra, and dynamic light scattering measurements. The formation of supramolecular polymeric aggregates with a molecular mass of 100 kDa in a nonaqueous solution from a telechelic dimer of isopropylidene guanosine in the presence of K+ ions is reported. The possible structure of macromonomers resulting from the development of G(4) quartets was deduced from DOSY NMR, circular dichroism spectra, and dynamic light scattering measurements.
    Langmuir 05/2007; 23(10):5283-5. DOI:10.1021/la070019g · 4.46 Impact Factor
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    L Petridis · Zs Kneffel · Zs Kispéter · P Horváth · Z Sidó · G Pavlik
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    ABSTRACT: The purpose of this study was to examine the effects of different sport activities on cardiac adaptation. Echocardiographic data of 137 athletes and 21 non-athletes were measured and compared in two age groups 15-16 and 17-18 years of age. Athletes belonged into three groups according to their sports activity (endurance events, power athletes, ball game players). The observed variables were related to body size by indices in which the exponents of the numerator and the denominator were matched. Left ventricular hypertrophy was manifest in all athletic groups. Power athletes had the largest mean left ventricular wall thickness (LVWTd) in both age groups. In the older age group differences between the athletic groups were smaller, but the endurance and power athletes had significantly higher wall thickness. Left ventricular internal diameter (LVIDd) was the largest in the endurance athletes, while mean relative muscle mass (LVMM) was the largest in the power athletes. LVMM of the older endurance athletes was significantly larger. Muscular quotient (MQ) was the highest in the endurance athletes; in the 17-18-year group there was no inter-event difference. Bradycardia was most manifest in the endurance athletes and ball game players, power athletes had higher resting heart rates than non-athletic subjects. It can be inferred that endurance training induces firstly an enlargement of the left ventricle what is then followed by an increase of muscle mass. In the studied functional and regulatory parameters no difference was found between the athletic and non-athletic groups.
    Acta Physiologica Hungarica 02/2004; 91(2):99-109. DOI:10.1556/APhysiol.91.2004.2.2 · 0.75 Impact Factor
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    ABSTRACT: A leinamicin nevű, DNS-hasító daganatellenes antibiotikum hatásáért felelős molekularészletét szintetikusan beültettük nukleozidokba, s így a daunomicin biológai aktivitásához hasonló értékű citotoxikus származékokat nyertünk. Acetilénkötést tartalmazó leinamicinanalógunk szintén hatásosnak bizonyult, s hozzájárult az antibiotikum hatásmechanizmusának felderítéséhez. Megvalósítottuk antibakteriális, a vankomicin-családhoz tartozó glikopeptid-antibiotikumok és daganatellenes antraciklin-antibiotikumok négyögsavdiamid molekularészlet segítségével kialakított konjugátumainak, illetve dimerjeinek szintézisét, s több esetben igen kedvező biológiai hatású származékokat kaptunk. Tanulmányoztuk szénhidrátok, antibiotikumok, nukleozidok telekelikus dimerjeinek biológiai hatását, illetve különleges aggregációs tulajdonságukat,. Metilgallátból kiindulva oxidatív dezaromatizációval, s cikloaddíciós reakciót felhasználva a perikozin nevű, citotoxikus antibiotikum áthidalt gyűrűs analógját szintetizáltuk. | The active structural portion of the DNA-cleaving anticancer antibiotic leinamycin was synthetically built into nucleosides. In this way new leinamycin analogs were obtained with citotoxicity comparable to that of daunomycin. A new type of leinamycin analog containing carbon-carbon triple bond was synthesized and it gave an important information for elucidation of mechanism of action of leinamycin. Using the squaric amide linker new conjugates and dimers of antibacterial glycopeptide antibiotics of the vancomycin group and of anticancer anthracyclines have been synthesized. Some of the conjugates possess very promising biological activity. The aggregation properties and antibacterial activity of telechelic dimers of antibiotics, carbohydrates and nucleosides have been studied. Bicyclic analogs of the cytotoxic antibiotic pericosin was synthesized from methyl gallate.

Publication Stats

30 Citations
11.44 Total Impact Points

Institutions

  • 2009–2012
    • Semmelweis University
      • Department of Medical Microbiology
      Budapeŝto, Budapest, Hungary
  • 2007–2009
    • University of Debrecen
      • • Department of Pharmaceutical Chemistry
      • • Department of Biochemistry and Molecular Biology
      Debreczyn, Hajdú-Bihar, Hungary