Antimicrobial susceptibility profile and research of mec A and erm genes in coagulase-negative staphylococci isolated from platelet concentrates bags

Abstract In recent years, several studies have described the clinical impact of bacterial infection associated with transfusion of platelet concentrates (PCs). Among the blood components, PCs are responsible for the highest rates of bacterial contamination as well as septic transfusion reactions. We assessed antimicrobial susceptibility profile, resistance to methicillin (MRCoNS), and resistance to macrolides, lincosamides and streptogramins of group B (MLSB) of 16 coagulase-negative staphylococci (CoNS) isolates from an investigation in 691 PCs bags. We then compared conventional and automated phenotypic methods, disc diffusion test (DD) and VITEK(r) 2, respectively as well as phenotypic and genotypic methods (Polymerase Chain Reaction - PCR). All CoNS were susceptible to vancomycin. The disc diffusion test characterized 18.75% as MRCoNS and 37.5% with inducible resistance to MLSB (iMLSB), and with VITEK(r) 2, 6.3% and 31.25%, respectively. The mecA gene was detected in 18.75% and the erm gene in 31.25% of the isolates. In this study, we found equal percentage values between presence of the mecA gene by PCR and resistance to methicillin using cefoxitin by DD test, evidence of the erm gene by PCR, and iMLSB resistance by automation (VITEK(r) 2). Moreover, we identified three strains with beta-lactamase overproduction, and the occurrence of a bigger mistake was verified when automation was compared with DD test. And we observed that D-test was the most reliable for the detection of iMLSB resistance in Staphylococcus sp.

Evaluation of Cellular Proliferative Activity in Patients with Oral Lichen Planus and Hepatitis C through AgNOR Method

The objective of this study was to evaluate the cellular proliferative potential of oral lichen planus (OLP) lesions from patients without hepatitis C virus (HCV) by means of AgNOR method, as well as the cellular proliferative potential of the normal oral mucosa from patients with HCV, treated or untreated by interferon and ribavirin. A cross-sectional study was developed to investigate four groups: 10 HCV+ patients without clinical signs of OLP who had never been treated for HCV infection - Group 1; 10 HCV+ patients that were under interferon and ribavirin treatment - Group 2; 15 patients with reticular OLP lesions histopathologically confirmed, without HCV - Group 3; and 15 blood donors without HCV infection and no clinical signs of OLP GROUP 4 Control Group. The cytological material of all groups was collected by the liquid-based cytology technique. Then, the sedimented material from each patient was filled with the Nucleolar Organizer Regions impregnation by silver method (AgNOR). The count of NORs was performed on 100 epithelial cell nuclei per patient using the Image Tool(tm) software. The Tukey HSD test was used to compare the median value of NORs among the groups and showed that the oral mucosa of HCV+ patients previously treated with anti-HCV drugs (GROUP 2), presented a higher average number of NORs in relation to others (p<0.05). The anti-HCV treatment may be related to increased cell proliferation of oral mucosa, indicating a possible relationship between OLP and HCV+ patients treated with interferon and ribavirin.

O propósito deste estudo foi avaliar o potencial proliferativo celular das lesões de líquen plano bucal (LPB) de pacientes sem vírus da hepatite C (VHC) por meio do método AgNOR, comparando-o ao potencial proliferativo celular da mucosa bucal normal de portadores de VHC, tratados ou não com interferon e ribavirina. Um estudo transversal foi realizado para investigar 4 grupos: 10 pacientes VHC+ sem sinais clínicos de LPB que nunca haviam sido tratados para a infecção por VHC - Grupo 1; 10 pacientes VHC+ que estavam sob tratamento com interferon e ribavirina - Grupo 2; 15 pacientes com LPB reticular histopatologicamente confirmado, sem VHC - Grupo 3; e 15 doadores de sangue sem infecção por VHC e sem sinais clínicos de LPB (Grupo 4 - Grupo de Controle). O material celular de todos os grupos foi coletado pela técnica da citologia em base líquida. Então, o material sedimentado de cada paciente foi submetido ao método da impregnação das regiões organizadoras nucleolares pela prata (AgNOR). A contagem das NORs foi realizada em 100 núcleos celulares epiteliais por paciente por meio do programa Image Tool(r). O teste Tukey HSD foi utilizado para comparar o valor médio de NORs entre os grupos e mostrou que a mucosa bucal dos pacientes VHC+ previamente tratados com fármacos anti-VHC (Grupo 2) apresentou maior número médio de NORs por núcleo em relação aos outros (p<0,05). O tratamento anti-VHC pode estar relacionado ao aumento da atividade proliferativa celular da mucosa bucal, aventando uma possível relação entre LPB e pacientes VHC+ tratados com interferon e ribavirina.

A segment and epithelium specific messenger ribonucleic acid fragment up-regulated by estradiol in the rat oviduct

Estradiol accelerates oviductal embryo transport in the rat through changes of genomic expression in oviductal cells. However, the genes involved are unknown. We used a differential display by reverse transcription-polymerase chain reaction to detect estradiol (E2)-dependent genes in the rat oviduct. Rats on day 2 of pregnancy were untreated or treated with 10 micrograms of E2 and the oviducts were extracted at 30, 180 and 360 min later and used to isolate RNA. Products of reverse transcriptase-PCR, made with pairs of arbitrary and oligo-deoxythymidine primers, were separated on denaturing polyacrylamide gels and candidate bands were excised and reamplified. Truly positive cDNA fragments determined by a single strand conformation polymorphism assay were cloned and sequenced. A ribonuclease protection assay confirmed that clone 25 is up-regulated by E2 in the oviduct at 30, 180 and 360 min. This clone exhibited no homology with known genes and in situ hybridization showed it is only expressed in the epithelial cells of the isthmic segment. Clone 25 is likely to represent a new gene, which is up-regulated by E2 in the epithelium of the isthmic segment of the rat oviduct. Its time frame of response is compatible with a mediator of the effect of E2 on oviductal embryo transport.

DNA alkylation by carbon-centered radicals

1. Over the last two decades, the prevalent view in chemical carcinogenesis has been that most free radicals do not bind to DNA. Recent studies, however, are demonstrating formation of adducts between DNA and free radicals such as hydroxyl radicals and aromatic cation radicals. 2. Within this context, we discuss the recent work from our group demonstrating DNA alkylation by carbon-centered radicals formed during biotransformation of genotoxic hydrazine derivatives both in vitro and in vivo. 3. The mutagenic potential of the identified methyl radical adduct, C8-methylguanine, is discussed, and other possible biological sources of carbon-centered radicals are presented