Oscar Fernando D'Urso

A filtration-based real-time PCR method for the quantitative detection of viable Salmonella enterica and Listeria monocytogenes in food samples.

We developed a novel filtration-based method that can eliminate dead or severely damaged Salmonella enterica and Listeria monocytogenes in food samples. This new method can recover all viable bacteria in less than 30 min, and can be coupled with a subsequent bacterial DNA extraction and real-time PCR. No statically significant differences (p<0.01) were found between real-time PCR results obtained separately from S. enterica and L. monocytogenes when different ratios of living and dead cells were used. The analytical sensitivity in both cases was 1 genome equivalent (GE), and the quantification was linear (R(2)>0.9969) over a 5-log dynamic range with PCR efficiencies >0.9754. When compared with the standard microbiological methods for the detection of these foodborne pathogens, the relative accuracy was excellent ranging from 95.72% to 104.48%. Finally, we applied the pre-treatment method to the direct detection of viable forms of these foodborne pathogens in food samples using yogurt as a model, the results being similar to those obtained using pure cultures.

miR-155 is up-regulated in primary and secondary glioblastoma and promotes tumour growth by inhibiting GABA receptors.

An altered expression of microRNAs (miRNAs) contributes both to the development of cancer and to the progression of the disease. Malignant tumours and tumour cell lines have widespread deregulated expressions of miRNAs compared to normal tissues. In this study, we investigated the expression profiles of 340 mammalian miRNAs in 93 cases of multiform glioblastoma (primary and secondary glioblastoma tumours), by means of DNA microarrays. We show that the expression profiles of 10 miRNAs can distinguish primary from secondary glioblastoma types. Moreover, we found elevated miR-155 levels in primary and secondary glioblastoma tissues as well as in glioblastoma primary cultures. We hypothesised that γ-aminobutyric acid A receptor 1 (GABRA1) is a miR-155 target, and studied the correlation between miR-155 up-regulation and the GABRA1 protein in cultured glioblastoma cells by miRNA silencing. We show that a decrease in miR-155 expression to normal levels restores the expression of GABRA1, making glioblastoma cells sensitive to signals that inhibit cell proliferation mediated by GABRA1. In conclusion, the expression patterns of different miRNAs characterise primary and secondary glioblastomas. The aberrant overexpression of miR-155 contributes to the malignant phenotype of glioblastoma cells removing growth inhibition.

Non-protein coding RNA biomarkers and differential expression in cancers: a review.

BackgroundIn these years a huge number of human transcripts has been found that do not code for proteins, named non-protein coding RNAs. In most cases, small (miRNAs, snoRNAs) and long RNAs (antisense RNA, dsRNA, and long RNA species) have many roles, functioning as regulators of other mRNAs, at transcriptional and post-transcriptional level, and controlling protein ubiquitination and degradation. Various species of npcRNAs have been found differentially expressed in different types of cancer. This review discusses the published data and new results on the expression of a subset of npcRNAs.ConclusionThese results underscore the complexity of the RNA world and provide further evidence on the involvement of functional RNAs in cancer cell growth control.

Non-coding RNAs change their expression profile after Retinoid induced differentiation of the promyelocytic cell line NB4

BackgroundThe importance of non-coding RNAs (ncRNAs) as fine regulators of eukaryotic gene expression has emerged by several studies focusing on microRNAs (miRNAs). miRNAs represent a newly discovered family of non coding-RNAs. They are thought to be crucial players of human hematopoiesis and related tumorigenesis and to represent a potential tool to detect the early stages of cancer. More recently, the expression regulation of numerous long ncRNAs has been linked to cell growth, differentiation and cancer although the molecular mechanism of their function is still unknown.NB4 cells are promyelocytic cells that can be induced to differentiation upon retinoic acid (ATRA) treatment and represent a feasible model to study changes of non coding RNAs expression between cancer cells and their terminally differentiated counterpart.Findingswe screened, by microarray analysis, the expression of 243 miRNAs and 492 human genes transcribing for putative long ncRNAs different from miRNAs in NB4 cells before and after ATRA induced differentiation. Our data show that 8 miRNAs, and 58 long ncRNAs were deregulated by ATRA induced NB4 differentiation.Conclusionour data suggest that ATRA-induced differentiation lead to deregulation of a large number of the ncRNAs that can play regulatory roles in both tumorigenesis and differentiation.

Correlative analysis of gene expression profile and prognosis in patients with gliomatosis cerebri

In modern clinical neuro‐oncology, the pathologic diagnoses are very challenging, creating significant clinical confusion and affecting therapeutic decisions and prognosis.

Intramedullary solitary fibrous tumor of dorsal spinal cord.

Solitary fibrous tumors (SFT) are rare neoplasms of mesenchymal origin involving soft tissues, mainly serosal sites; the spinal cord location is uncommon. We report a case of SFT occurring in the thoracic spinal cord, discussing histological, ultrastructural and molecular aspects. A 75‐year‐old woman with an MRI suggesting a dorsal intracanalar lesion was admitted to our institution. T5–T7 laminectomies were performed and an intramedullary tumor was discovered. The tumor arose within the spinal cord and was completely removed. Tumor samples were processed for histological, ultrastructural and molecular analysis (comparative genomic hybridization [CGH], methylation status of O6‐methylguanine–DNA methyltransferase [MGMT], p16, deleted in colorectal cancer [DCC] and death‐associated protein kinase 1 [DAPK1]). The histological examination demonstrated a proliferation of spindle‐shaped cells with a collagen‐matrix background. Immunohistochemical staining was positive for vimentin and CD34 and negative for S‐100 and epithelial membrane antigen. A histological diagnosis of SFT was made. The ultrastructural examination showed undifferentiated cells within a collagenous matrix and sparse extravascular basement membrane. CGH analysis revealed deletion of 9p21 and losses on 2q, 3p, 16q and 19q and gains on 7q; furthermore, no aberrant methylation pattern was found in the promoter region of MGMT, p16, DCC and DAPK1 genes. On the second‐year follow‐up, the patient was neurologically intact. The occurrence of SFT within the spinal cord parenchyma and its histological characteristics demonstrate that SFTs are not restricted to serosal surfaces. The course of spinal cord SFT is unknown and long‐term follow‐up is necessary. The histological, ultrastructural and molecular findings are important for the diagnosis and the authors provide a literature review of these aspects.

Listeria monocytogenes detection with surface plasmon resonance and protein arrays

In this study label-free a SPR immunosensor and a protein array based methods were used for their application in bacterial detection. L. monocytogenes, one of the most difficult to treat bacteria, was used as model pathogen. While the use of DNA arrays for bacteria detection and identification is largely documented, no studies are available on protein array (PA) based bacteria detection. In protein array approach an affinity-purified monoclonal antibody was used as capture antibody. Protein array detection limit was of 102-103CFU/mL. SPR immunoassays were prepared by chemically binding L. monocytogenes cells on a proper gold substrate. After immobilization of antigen on gold substrate, a further incubation with anti-L. monocytogenes antibodies was performed. The technique was revealed as powerful and fast method for the monitoring of binding between the investigated antigen and antibodies. On the other side, array based methods, although more expensive due to the labelling step, can be used with a set of species-specific antibodies allowing for simultaneous detection of multiple pathogens in a single hybridization step in no more then 2.5 h.

Gliomatosis cerebri type II: two case reports

IntroductionTwo types of gliomatosis cerebri exist: Type I and Type II. We report the results of a histological and genetic study of two cases of gliomatosis cerebri Type II, correlating these results with therapy and prognosis.Case presentationTwo patients, a 52-year-old man (Patient 1) and a 76-year-old man (Patient 2) with gliomatosis cerebri II were admitted to our institution; they underwent surgical treatment and received radiotherapy and chemotherapy. At the 24-month follow-up, Patient 1 was still alive, while Patient 2 had died. The poor prognosis of Patient 2 was underlined by molecular analysis which showed that the angiogenesis related genes VCAM1 and VEGF were overexpressed, reflecting the high degree of neovascularization.ConclusionGenes involved in drug resistance and metallothioneins were highly expressed in Patient 2 and this, associated with unmethylated O6-methylguanine methyltransferase, can explain the lack of response to chemotherapy.

Giant cell angiitis of the central nervous system with atypical presentation

Giant cell angiitis of the CNS is an uncommon form of vasculitis. Neurological manifestations, both of the peripheral and CNS, are common. The most frequent manifestations are visual loss and stroke. Hemorrhagic onset is uncommon. Most cases have a fatal outcome and a tissue diagnosis is rarely established in life. We describe an unusual case of giant cell angiitis beginning as a hemorrhagic tumoral‐like lesion. The results of the histological and ultrastructural analysis have also been reported. Our case illustrates that giant cell angiitis should be considered as a cause of intracerebral hemorrhage, particularly when associated with a relapsing and remitting disease of the CNS.