A small molecule enhances arrestin-3 binding to the β-adrenergic receptor.

G protein-coupled receptor (GPCR) signaling is terminated by arrestin binding to a phosphorylated receptor. Binding propensity has been shown to be modulated by stabilizing the pre-activated state of arrestin through point mutations or C-tail truncation. Here, we hypothesize that pre-activated rotated states can be stabilized by small molecules, and this can promote binding to phosphorylation-deficient receptors, which underly a variety of human disorders.

Peptide Nucleic Acids in Saturation Transfer Difference Nuclear Magnetic Resonance Experiments: A Simple and Valuable Tool for Studying HuR-Small Molecule Complexes.

Ribonucleic acid (RNA)-binding proteins (RBPs) play a key role in regulating RNA stability, fate, function, gene expression, post-transcriptional modifications, and cellular activities. Among the various RBPs identified to date, the Hu proteins have been the most extensively studied. Specifically, HuR influences several cellular processes, including cell proliferation, differentiation, and stress response, and it is frequently overexpressed in various solid tumors.

Antibiotic resistance and class 1 integron patterns of non-typhoidal human Salmonella serotypes isolated in Hungary in 2002 and 2003.

The antibiotic resistance profiles of 5178 Salmonella strains representing 19 non-typhoidal serotypes isolated from human salmonellosis cases in Hungary in 2002 and 2003 were analysed for resistance to 10 antibiotic agents. The most frequent resistances were to nalidixic acid (Nx), streptomycin (S), tetracycline (Tc), ampicillin (Amp) and chloramphenicol (Cm) (ranging from 27% to 13%). Forty-five percent of the Salmonella Typhimurium strains were multiple resistant and belonged mainly to the definitive phage types 104 and U302.

Comparison of traditional and molecular typing methods of Escherichia coli O157.

An account is given using typing methods and detection of virulence genes of different serotypes of Escherichia coli isolated in Hungary. By hybridization using SLT-I and SLT-II probes and PCR method using stx1-2, eae and ehx primers we could differentiate O157 strains of different serotypes into eight (stx, eae, ehxA positive; stx, eae positive; stx, ehxA positive; stx positive; eae, ehxA positive; eae positive; ehxA positive; stx, eae, ehxA negative) types. The discriminatory power of phage typing proves to be much higher than that of the plasmid profile.

Analysis of gene cassettes of streptomycin-spectinomycin resistance of Hungarian Salmonella enterica serotype Typhimurium strains.

By PCR using the ant(3")-Ia primer pair the aadA gene was detected in 34 streptomycin- and spectinomycin-resistant Salmonella enterica serotype Typhimurium strains. Out of them 12 belonged to DT104 and 22 to non-DT104 phage type. Using different primer combinations it was demonstrated that this gene was integron-associated in all cases: in the DT104 strains it was generally contained by a 1 kb integron while in the majority of the non-DT104 strains by a 2.

Integron content of Salmonella enterica serotype Typhimurium strains isolated in Hungary in the years 1997-1999.

The integron content of 52 DT104/U302 phage type strains and 53 non-DT104/U302 strains of Salmonella enterica serotype Typhimurium (S. Typhimurium) was studied in PCR experiments using a 5'-CS/3'-CS primer pair (Lévesque et al., 1995).

Epidemiology and characterization of animal Salmonella enterica subspecies Enterica serotype typhimurium DT104 in Hungary.

Reports on the internationally emerging significance of multiresistant zoonotic Salmonella in animals and man prompted studies to estimate the significance of multiresistant Salmonella enterica subspecies enterica serotype Typhimurium (S. Typhimurium) phage type DT104 of animal origin in Hungary. A collection of 231 strains (primarily of goose, turkey, poultry and porcine origin from the years 1997-1998) was tested for resistance against 7 selected antibiotics (ampicillin, chloramphenicol, enrofloxacin, nalidixic acid, streptomycin, tetracycline and sulphamethoxazole).

The spread and antibiotic resistance of Salmonella enterica serotype typhimurium DT104 in Hungary.

Comparison of phage types (PTs) determined by Felix and Callow's and Anderson's methods was performed testing 99 human strains of S. enterica serotype Typhimurium (S. typhimurium) isolated in Hungary.

A colony blot immunoassay to detect enteroinvasive Escherichia coli and Shigella in water samples.

Aims: The aim of the study was to develop a colony blot immunoassay to detect Shigella and enteroinvasive Escherichia coli (EIEC) in water.

Methods And Results: Spiked samples were filtered through nitrocellulose membranes. Colony prints on the filters were tested with a monoclonal antibody specific to IpaC, an antigen coded by the invasion plasmid of Shigella and EIEC.

Rapid combined assay for Salmonella detection in food samples.

A rapid method was developed to detect salmonellae in food samples. The method gave a possibility to obtain results after 28 h 30 min. The preenrichment in buffered peptone water lasted for 6 h, the enrichment in Rappaport-Vassiliadis medium was applied for 18 h followed by PCR with INVA1-INVA2 primer pair, adapting Chiu and Ou's method.

Partial inhibition of amplifications by primers of EHEC genes.

Diagnostic value of multiplex polymerase chain reaction (PCR) was examined by using three primer pairs, specific for the common conserved region of stx1 and stx2, eae and an enterohaemolysin A gene (ehxA). The sensitivity in respect of each amplicon decreased with three exponents comparing to the individual PCR reactions. These PCR reactions were partially inhibited by the presence of certain additional primers.

Phage restriction and the presence of small plasmids in Salmonella enteritidis.

Between 1990-1994, a total of 16,505 S. enteritidis strains of human, animal and food origin were phage-typed, using the Hungarian scheme and the changes of incidence of the dominant phage types were monitored. The incidence of PT1 (corresponding to Ward's PT1 was very high between 1990 and 1992 (67.

Detection of VTEC using specific DNA probes and complex typing of Escherichia coli O157.

The incidence of E. coli causing hemorrhagic colitis (HC) or non-bloody enteritis in Hungary was studied using SLT-I and SLT-II gene-probes as well as Vero-cell toxicity and Verotox-F tests. Out of 41 E.

Effect of precultivation conditions on colicin susceptibility in Escherichia coli.

The effect of 20 colicins and cloacin was studied after various precultivations. Nutrient agar supplemented with subinhibitory concentration of EDTA used for precultivation or elevating the growth-temperature of the inoculum from 37 degrees C to 42 degrees C increased the susceptibility of wild-type (smooth) Escherichia coli strains to the inhibitory action of some colicins. There were great differences among the colicins in respect to these effects.

Genotypic and phenotypic characters and nosocomial significance of bacteria endemic in neonatal intensive care units.

The degree of colonization was determined by complex typing (sero-, phage, colicin-, pyocin typing, plasmid profile analysis) of 212 Escherichia coli, 232 Klebsiella, 117 Pseudomonas aeruginosa and 52 Staphylococcus aureus strains isolated from nose, throat, ear and other sources of 563 new-born infants in gynaecological and maternity wards of two neonatal intensive care units (NICU I and II) during a one year period. The presence of Klebsiella strains was more frequent in NICU I and E. coli and P.

Examination of verocytotoxin producing capacity and determination of the presence of Shiga-like toxin genes in human Escherichia coli isolates.

A total of 93 wild type Escherichia coli of human origin (mostly representing intestinal isolates from Hungary) were examined for the presence of Shiga-like-toxin (SLT) genes using SLT-I, SLT-II and enterohemorrhagic E. coli (EHEC) specific DNA probes. The structural genes of the above specificity were labelled by random priming using 32-P-dCTP.

Correlation between human lactoferrin binding and colicin susceptibility in Escherichia coli.

Escherichia coli H10407 demonstrated low 125I-human lactoferrin (HLf) binding (7%) and was insusceptible to group A (A, E1, E2, E3, E6, and K) and group B (B, D, Ia, Ib, and V) colicins. Conversely, a spontaneous HLf high-binding (44%) variant, H10407(Lf), demonstrated an increase susceptibility to both colicin groups. Colicin-insusceptible E.

Specific binding of lactoferrin to Escherichia coli isolated from human intestinal infections.

The degrees of human lactoferrin (HLf) and bovine lactoferrin (BLf) binding in 169 Escherichia coli strains isolated from human intestinal infections, and in an additional 68 strains isolated from healthy individuals, were examined in a 125I-labelled protein binding assay. The binding was expressed as a percentage calculated from the total labelled ligand added to bacteria. The HLf and BLf binding to E.

Clonal distribution of K1 and K5 antigen possessing Escherichia coli isolates.

A significant difference was observed in the occurrence of the examined markers (Col+, ColV+, Hly+, Aer+, AbR) and in the plasmid carrier state between strains with and without K1 and K5 antigens. Plasmids of the same size were harboured by serotypes possessing K1 and K5 antigens, e.g.

Relative surface hydrophobicity, antigen K1 and haemagglutinating activity are associated in Escherichia coli.

Hydrophobic property of 136 Escherichia coli strains was examined by salt aggregation test (SAT). Out of the tested strains 61 were SAT positive. The correlations among the surface properties characterized by SAT and other phenotypical properties, e.

Cloacin tolerance and aspecific colicin insensitivity of human Escherichia coli strains.

Of 182 wild-type human, aerobactin producer Escherichia coli strains 86.3% were insensitive to cloacin. All randomly chosen 51 strains were relatively cloacin tolerant.

Association of virulence markers with animal pathogenicity of Escherichia coli in different models.

Employing chicken and several strains of mice, different routes (intraperitoneal, subcutaneous) of infections and isogenic pairs of strains, association of virulence markers with animal pathogenicity was studied in Escherichia coli. Mouse virulence of avian strains was less significant than the lethality for chicks of human strains. LD50 in various animals did not differ significantly.

In vitro and in vivo (LD50) effects of human lactoferrin on bacteria.

The in vitro and in vivo effects of human lactoferrin (LF), apoLF, iron saturated LF and of different iron containing compounds (ferric chloride, ferric sodium citrate) were studied on Escherichia coli, Salmonella typhi-murium and Pseudomonas aeruginosa reference and wild-type strains with well-defined virulence markers (i.e. enterochelin, aerobactin production).

The frequency of aerobactin production and its effect on the pathogenicity of human Escherichia coli strains.

A total of 981 human Escherichia coli strains (including 632 strains isolated between 1979 and 1983 and 349 strains isolated in 1987) was examined for aerobactin production by biological qualitative test. Aerobactin positivity was found in 55.1% and 47.