RESUMO
Gastric cancer is one of the most common malignancy worldwide with a prognosis less than 1 year in unresectable or metastatic disease. HER2 expression is the main biomarker to lead the addition of trastuzumab to first line systemic chemotherapy improving the overall survival in advanced HER2-positivegastric adenocarcinoma. The inevitable development of resistance to trastuzumab remains a great problem inasmuch several treatment strategies that have proven effective in breast cancer failed to show clinical benefit in advanced gastric cancer. In this review, we summarize the available data on the mechanisms underlying primary and secondary resistance toHER2-targeted therapy and current challenges in the treatment of HER2-positive advanced gastric cancer refractory to trastuzumab. Further, we describe the prognostic value of new non-invasive screening techniques, the current development of novel agents such us HER2 antibody-drug conjugates and bispecific antibodies, and the strategies with antitumor activity on going.
Assuntos
Adenocarcinoma , Imunoconjugados , Neoplasias Gástricas , Adenocarcinoma/tratamento farmacológico , Humanos , Imunoconjugados/uso terapêutico , Receptor ErbB-2/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/metabolismo , Trastuzumab/uso terapêuticoRESUMO
The typhlocybine, Zygina nivea Mulsant & Rey 1855, was found in urban areas of Argentina colonizing trees of poplar (Populus alba L. and P. nigra L.). This is the first mention of the genus Zygina Fieber from the Neotropical region. In this paper redescription of the male, description of the female, distributional and host plant data, and behavioural observations of this species are given.
Assuntos
Comportamento Animal , Hemípteros/classificação , Populus/parasitologia , Animais , Argentina , Feminino , Masculino , Pigmentação , Densidade DemográficaAssuntos
Alcaligenes faecalis/isolamento & purificação , Infecção Hospitalar/epidemiologia , Surtos de Doenças , Infecções por Bactérias Gram-Negativas/epidemiologia , Argentina/epidemiologia , Técnicas de Tipagem Bacteriana , Criança , Pré-Escolar , Análise por Conglomerados , Infecção Hospitalar/microbiologia , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Eletroforese em Gel de Campo Pulsado , Infecções por Bactérias Gram-Negativas/microbiologia , Hospitais , Humanos , Lactente , Recém-Nascido , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
The mechanism by which Helicobacter species are transmitted remains unclear. To examine the possible role of environmental transmission in marine mammals, we sought the presence of Helicobacter spp. and non-Helicobacter bacteria within the order Campylobacterales in water from the aquatic environment of marine mammals, and in fish otoliths regurgitated by dolphins. Water was collected from six pools, two inhabited by dolphins and four inhabited by seals. Regurgitated otoliths were collected from the bottom of dolphins' pools. Samples were evaluated by culture, PCR and DNA sequence analysis. Sequences from dolphins' water and from regurgitated otoliths clustered with 99.8-100% homology with sequences from gastric fluids, dental plaque and saliva from dolphins living in those pools, and with 99.5% homology with H. cetorum. Sequences from seals' water clustered with 99.5% homology with a sequence amplified from a Northern sea lion (AY203900). Control PCR on source water for the pools and from otoliths dissected from feeder fish were negative. The findings of Helicobacter spp. DNA in the aquatic environment suggests that contaminated water from regurgitated fish otoliths and perhaps other tissues may play a role in Helicobacter transmission among marine mammals.
Assuntos
Campylobacter/isolamento & purificação , Helicobacter/isolamento & purificação , Água do Mar/microbiologia , Animais , Campylobacter/genética , Golfinhos , Peixes/microbiologia , Otárias , Helicobacter/genética , Filogenia , Focas VerdadeirasRESUMO
Gastrointestinal lesions with uncertain etiology have been widely described among pinnipeds. The aim of our study was to investigate the presence of Helicobacter spp. in the gastric mucosa of South American fur seals (Arctocephalusaustralis). Gastric biopsies from thirteen seals, stranded on the shores of the Southwestern Atlantic Ocean in Argentina, were evaluated for the presence of Helicobacter spp. by PCR and DNA sequence analysis. Six gastric biopsies were positive for Helicobacter spp. Pairwise sequence comparisons showed less than 95% identity to novel Helicobacter spp. described from pinnipeds from North America and Australia. However, phylogenetic analysis revealed that the South American fur seal sequences clustered with 99-100% homology with H. cetorum, a species isolated from dolphins and whales. The presence of H. cetorum in pinnipeds, if confirmed by its isolation from the gastric mucosa of these mammals, demonstrates the wide host range of this bacterium in the marine environment.
Assuntos
Otárias/microbiologia , Infecções por Helicobacter/veterinária , Helicobacter/isolamento & purificação , Gastropatias/veterinária , Animais , Argentina , Sequência de Bases , Biópsia/veterinária , DNA Bacteriano/química , DNA Bacteriano/genética , Mucosa Gástrica/microbiologia , Helicobacter/genética , Infecções por Helicobacter/microbiologia , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Alinhamento de Sequência , Gastropatias/microbiologiaRESUMO
The aim of this study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from different infectious sites of hospitalized patients at two university hospitals. Fourteen isolates were analyzed by repetitive sequence based PCR (Rep-PCR), randomly amplified polymorphic DNA assay (RAPD-PCR), and pulsed-field gel electrophoresis (PFGE). We found that a prevalent clone of MRSA, susceptible to rifampin, minocycline, and trimethoprim/sulfamethoxazole (RIF(s), MIN(s), TMS(s)) was present in both hospitals in replacement of the multiresistant MRSA South American clone, previously described in these hospitals. The staphylococcal chromosomal cassette (SCCmec) type I element was detected in this new clone.
Assuntos
Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Hospitais Universitários/estatística & dados numéricos , Resistência a Meticilina , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Academias e Institutos/estatística & dados numéricos , Argentina/epidemiologia , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Infecção Hospitalar/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Eletroforese em Gel de Campo Pulsado , Humanos , Meticilina/farmacologia , Resistência a Meticilina/genética , Minociclina/farmacologia , Proteínas de Ligação às Penicilinas , Reação em Cadeia da Polimerase , Técnica de Amplificação ao Acaso de DNA Polimórfico , Rifampina/farmacologia , América do Sul/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Combinação Trimetoprima e Sulfametoxazol/farmacologia , Saúde da População UrbanaRESUMO
The aim of this study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from different infectious sites of hospitalized patients at two university hospitals. Fourteen isolates were analyzed by repetitive sequence based PCR (Rep-PCR), randomly amplified polymorphic DNA assay (RAPD-PCR), and pulsed-field gel electrophoresis (PFGE). We found that a prevalent clone of MRSA, susceptible to rifampin, minocycline, and trimethoprim/sulfamethoxazole (RIF S, MIN S, TMS S) was present in both hospitals in replacement of the multiresistant MRSA South American clone, previously described in these hospitals. The staphylococcal chromosomal cassette (SCCmec) type I element was detected in this new clone.
El objetivo de este trabajo fue la caracterización de aislamientos de Staphylococcus aureus meticilina-resistentes (SAMR), provenientes de diferentes procesos infecciosos de pacientes internados en dos hospitales universitarios. Catorce aislamientos fueron analizados mediante la PCR de secuencias repetitivas (Rep-PCR), la amplificación al azar de ADN polimórfico (RAPD-PCR) y la electroforesis de campo pulsado (PFGE). Encontramos que un clon prevalente de SAMR, sensible a rifampicina, minociclina y trimetoprima-sulfametoxazol (RIF S, MIN S, TMS S) estaba presente en ambos hospitales, reemplazando al clon SAMR y multi-resistente previamente descrito en estos mismos hospitales. En este nuevo clon se detectó el cassette cromosómico estafilocócico SCCmec tipo I.
Assuntos
Humanos , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Hospitais Universitários/estatística & dados numéricos , Resistência a Meticilina , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Academias e Institutos/estatística & dados numéricos , Argentina/epidemiologia , Técnicas de Tipagem Bacteriana , Proteínas de Bactérias/genética , Infecção Hospitalar/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Eletroforese em Gel de Campo Pulsado , Resistência a Meticilina/genética , Meticilina/farmacologia , Minociclina/farmacologia , Reação em Cadeia da Polimerase , Técnica de Amplificação ao Acaso de DNA Polimórfico , Rifampina/farmacologia , América do Sul/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/classificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Combinação Trimetoprima e Sulfametoxazol/farmacologia , Saúde da População UrbanaRESUMO
The aim of this study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from different infectious sites of hospitalized patients at two university hospitals. Fourteen isolates were analyzed by repetitive sequence based PCR (Rep-PCR), randomly amplified polymorphic DNA assay (RAPD-PCR), and pulsed-field gel electrophoresis (PFGE). We found that a prevalent clone of MRSA, susceptible to rifampin, minocycline, and trimethoprim/sulfamethoxazole (RIF(s), MIN(s), TMS(s)) was present in both hospitals in replacement of the multiresistant MRSA South American clone, previously described in these hospitals. The staphylococcal chromosomal cassette (SCCmec) type I element was detected in this new clone.
RESUMO
Isolates of Helicobacter pylori from 88 patients were characterised by cagA status, cagA pathogenicity island (PAI) right-end motifs, iceA, vacA and lspA-glmM genotypes, primarily by PCR-based analysis, to investigate whether Argentinean isolates differed from those recovered in southern Europe or other Latin American countries. PCR-based analysis of vacA alleles was confirmed by reverse hybridisation in 56 cases, while sequence analysis was performed either when iceA and vacA genotypes could not be determined by PCR, or to investigate PCR and reverse hybridisation vacA genotyping discordance. Typing by lspA-glmM restriction fragment length polymorphism was performed with HhaI and AluI. The pattern of cag PAI right-end motifs and the prevalence of type Ia were similar to those in isolates from southern European countries, with cagA(+)/iceA1/vacA-s1 m1 being the commonest genotype. Reverse hybridisation identified a vacA-s1a/s1b recombinant allele, confirmed by sequencing analysis. Analysis of lspA-glmM genotypes identified at least 73 unrelated strains. Few mixed infections were identified, but in one case, isolates from a single biopsy exhibiting two vacA alleles were shown by lspA-glmM fingerprints to be two unrelated strains. No associated effect on ulcer disease risk was demonstrated by analysis of cagA, vacA and iceA status. Overall, the isolates of H. pylori from Argentina were similar to isolates from southern Europe or Latin American countries, and infections were associated mainly with single H. pylori strains.
Assuntos
Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Helicobacter pylori/classificação , Polimorfismo Genético , Adulto , Idoso , Antígenos de Bactérias/química , Argentina , Proteínas de Bactérias/química , Sequência de Bases , Feminino , Genótipo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
Staphylococcus aureus is the most prevalent pathogen causing mastitis of dairy ruminants. This study was developed to ascertain the genotypes and genealogical relationship among strains isolated from milk of bovines with mastitis in Argentina. Molecular epidemiological analysis of S. aureus was performed on 112 isolates from 21 districts. Clonality was assessed by SmaI pulsed-field gel electrophoresis (PFGE) typing, automated EcoRI ribotyping and restriction enzyme analysis of plasmid (REAP) DNA profiles. A total of 22 band patterns distributed in four clusters were found by SmaI PFGE analysis. The similarity of clusters 2, 3 and 4 with cluster 1 was 0.73, 0.69 and 0.33, respectively, and 101 of 112 isolates belonged in cluster 1. PFGE band patterns from 42 isolates within cluster I were indistinguishable from each other (type A). The second largest group of isolates with indistinguishable PFGE band patterns was subtype A11, which was composed of 19 isolates. Automated ribotyping assigned the 112 isolates into 13 ribotypes. Among these, the most prevalent ribotypes I and VI were composed of 49 and 35 isolates respectively. Although there was certain correspondence between PFGE genotypes and ribotypes, further discrimination was achieved by combining both methods. REAP DNA profile analysis was useful to provide even further discrimination between isolates with identical PFGE genotype and ribotype. The most prevalent S. aureus strains A/I and A11/VI were widely distributed in the country and were not restricted to individual nearby locations. Prevalence of these two strains varied consecutively within a period of 8 years. Whether the shift in type prevalence was due to selection of a phenotypic trait remains undisclosed.