P53 controls the growth and survival of cells by acting in response to a multitude of cellular stresses. It is, however, not yet fully understood how different p53 activation pathways result in either cell cycle arrest or apoptosis. We and others have described an N-terminally truncated p53 protein (p53/47) originating from a second translation initiation site in the p53 messenger RNA (mRNA), which can interact with p53 and impose altered stability and transactivation properties to p53 complexes. Here we show that cap-dependent and cap-independent mechanisms of initiation govern the translation of the p53 mRNA. Changes in synthesis of full-length p53 or p53/47 are regulated through distinct cell stress-induced pathways acting through separate regions of the p53 mRNA. We also show that some cytotoxic drugs require the presence of full-length p53 to induce apoptosis, whereas for others p53/47 is sufficient. This indicates that by harbouring alternative translation initiation sites, the p53 mRNA gives rise to different levels of the p53 isoforms which help to orchestrate the cell biological outcome of p53 activation in response to different types of cell stress. This sheds new light into the way p53 can integrate and differentiate a large multiplicity of changes in the cellular environment.

Aims:  To determine the presence of antibiotic‐resistant faecal Escherichia coli and Enterococcus spp. in feral pigeons (Columba livia forma domestica) in the Czech Republic. Methods and Results:  Cloacal swabs of feral pigeons collected in the city of Brno in 2006 were cultivated for antibiotic‐resistant E. coli. Resistance genes, class 1 and 2 integrons, and gene cassettes were detected in resistant isolates by polymerase chain reaction (PCR). The samples were also cultivated for enterococci. Species status of enterococci isolates was determined using repetitive extragenic palindromic‐PCR. Resistance genes were detected in resistant enterococci by PCR. E. coli isolates were found in 203 of 247 pigeon samples. Antibiotic resistance was recorded in three (1·5%, nE. coli = 203) isolates. Using agar containing ciprofloxacin, 12 (5%, nsamples = 247) E. coli strains resistant to ciprofloxacin were isolated. No ESBL‐producing E. coli isolates were detected. A total of 143 enterococci were isolated: Ent. faecalis (36 isolates), Ent. faecium (27), Ent. durans (19), Ent. hirae (17), Ent. mundtii (17), Ent. gallinarum (12), Ent. casseliflavus (12) and Ent. columbae (3). Resistance to one to four antibiotics was detected in 45 (31%) isolates. Resistances were determined by tetK, tetL, tetM, tetO, aac(6′)aph(2′′), ant(4′)‐Ia, aph(3′)‐IIIa, ermB, pbp5, vanA and vanC1 genes. Conclusions:  Antibiotic‐resistant E. coli and Enterococcus spp. occurred in feral pigeons in various prevalences. Significance and Impact of the Study:  Feral pigeon should be considered a risk species for spreading in the environment antimicrobial resistant E. coli and enterococci.

The study illustrates that ESBL-producing E. coli, as well as plasmids carrying ESBL genes of clinical interest, can be easily transferred among horses, humans and flies living in close contact.

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The platinum(II)-based complex cisplatin is one of the most frequently used antitumour agents; however, a high incidence of harmful side effects and the frequent emergence of acquired resistance are the major clinical problems. The novel platinum(IV)-based complex LA-12 exhibits a high efficacy against cancer cell lines, including cisplatin-insensitive cells, but the mechanisms by which LA-12 perturbs cell growth are unclear. We tested the effects of LA-12 on the p53 response and demonstrate that LA-12 induces unique changes in the profile of gene expression compared with cisplatin and doxorubicin. Furthermore, the ability of LA-12 to disrupt cellular proliferation is greatly enhanced by the expression of p53 and p53/47 indicating both p53-dependent and p53-independent effects of LA-12. Exposure of the human cancer cell lines H1299, A2780, BT549 and BT474 to LA-12 alters the expression of p53 and p53/47 in both a time-dependent and dose-dependent manner. Treatment of cells with a low concentration of the drug results in accumulation of p53 and p53/47 concomitant with their posttranslational modification, whereas a high dose results in the disappearance of both the forms of p53. The distinct p53 activation profile of LA-12 compared with cisplatin and doxorubicin provides a molecular explanation for the ability of this drug to treat cisplatin-resistant cells and indicates its potential usefulness as an alternative antitumour agent in first-line therapy or as a second-line therapy in patients with acquired cisplatin resistance.

ABSTRACT:Papillomatous skin lesions from a green lizard (Lacerta viridis) were examined histologically, using electron microscopy and DNA was isolated from the lesions for herpesviral DNA detection. Histology confirmed the lesions to be squamous epithelial papillomas. Using electron microscopy, no virus particles were detected. The specific sequence of herpesviral DNA-directed DNA polymerase (EC 2.7.7.7) was amplified using degenerate primers in a nested format. The 235-base-pair (bp) sequence was sequenced and compared with previously published DNA-directed DNA polymerase sequences from various reptile herpesviruses. The sequence from the green lizard showed significant similarity with sequence of fibropapilloma-associated turtle herpesviruses from sea turtles.

A total of six cases and 37 suspect cases of skin avipoxvirus infection in great tits (Parus major) have been described in central Europe since 2005. Most of the cases were diagnosed during the winter season, from October to March. Analyses of the 4b core protein gene showed identical or almost identical DNA sequence in six isolates (one from Austria, three from Hungary, and two from Czech Republic). A morphogenesis of the avipoxvirus including a constitution of acidophilic-type inclusions (ATIs) was documented by electron microscopy in cells from lesions on great tits found in Czech Republic. Moreover, the ATI body protein gene was demonstrated using polymerase chain reaction in the isolate that caused ATIs. A number of new cases of poxvirus infection in great tits have emerged in central Europe since 2005, and the reason for this sudden increase remains unknown.

In this study, we characterized the effects of LA-12 on tumor cell lines possessing wild type p53 and on p53-deficient/mutant cell lines and the results were compared to those obtained using cisplatin. We have determined changes of p53 levels, of its transcriptional activity, of its posttranscriptional modifications and the effect of the treatment on the cell cycle, on the induction of apoptosis and on gene expression. LA-12 induces weak accumulation of both transcriptionally active p53 tumor suppressor and of p21(WAF1/CIP1) protein. LA-12 and cisplatin also significantly differ in their effects on apoptosis and cell cycle and on gene expression spectra in studied cell lines. LA-12 induces higher apoptosis levels in comparison with those induced by cisplatin, especially in p53-deficient H1299 cells and in MCF-7DD cells with transcriptionally inactive p53. We suggest that LA-12-mediated apoptosis is not fully dependent on p53. This confirms the therapeutic potential of LA-12 as a more potent cytostatic agent for both tumor cells expressing wild type p53 and for p53-deficient or mutant cells.