117 research outputs found

    Fasting induces a biphasic adaptive metabolic response in murine small intestine

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    BACKGROUND: The gut is a major energy consumer, but a comprehensive overview of the adaptive response to fasting is lacking. Gene-expression profiling, pathway analysis, and immunohistochemistry were therefore carried out on mouse small intestine after 0, 12, 24, and 72 hours of fasting. RESULTS: Intestinal weight declined to 50% of control, but this loss of tissue mass was distributed proportionally among the gut's structural components, so that the microarrays' tissue base remained unaffected. Unsupervised hierarchical clustering of the microarrays revealed that the successive time points separated into distinct branches. Pathway analysis depicted a pronounced, but transient early response that peaked at 12 hours, and a late response that became progressively more pronounced with continued fasting. Early changes in gene expression were compatible with a cellular deficiency in glutamine, and metabolic adaptations directed at glutamine conservation, inhibition of pyruvate oxidation, stimulation of glutamate catabolism via aspartate and phosphoenolpyruvate to lactate, and enhanced fatty-acid oxidation and ketone-body synthesis. In addition, the expression of key genes involved in cell cycling and apoptosis was suppressed. At 24 hours of fasting, many of the early adaptive changes abated. Major changes upon continued fasting implied the production of glucose rather than lactate from carbohydrate backbones, a downregulation of fatty-acid oxidation and a very strong downregulation of the electron-transport chain. Cell cycling and apoptosis remained suppressed. CONCLUSION: The changes in gene expression indicate that the small intestine rapidly looses mass during fasting to generate lactate or glucose and ketone bodies. Meanwhile, intestinal architecture is maintained by downregulation of cell turnove

    Genomic and biological characterization of a velogenic Newcastle disease virus isolated from a healthy backyard poultry flock in 2010

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    <p>Abstract</p> <p>Background</p> <p>Newcastle disease virus (NDV) causes severe and economically important disease in poultry around the globe. None of NDV strains in Pakistan have been completely characterized and the role of rural poultry in harbouring NDV is unclear. Since they have a very important role for long-term circulation of the virus, samples were collected from apparently healthy backyard poultry (BYP) flocks. These samples were biologically analyzed using mean death time (MDT) and intracerebral pathogenicity index (ICPI), whereas genotypically characterized by the real-time PCRs coupled with sequencing of the complete genome.</p> <p>Findings</p> <p>Despite of being non-pathogenic for BYP, the isolate exhibited MDT of 49.6 h in embryonated chicken eggs and an ICPI value of 1.5. The F gene based real-time PCR was positive, whereas M-gene based was negative due to substantial changes in the probe-binding site. The entire genome of the isolate was found to be 15192 nucleotides long and encodes for six genes with an order of 3'-NP-P-M-F-HN-L-5'. The F protein cleavage site, an indicative of pathogenicity, was <sup>112</sup>RRQKRF<sup>117</sup>. Complete genome comparison indicated that the RNA dependent RNA polymerase gene was the most and the phosphoprotein was least conserved gene, among all the genes. The isolate showed an Y526Q substitution in the HN protein, which determines neuraminidase receptor binding and fusion activity of NDV. Phylogenetic analysis, based on F and HN genes, classified this isolate into genotype VII, a predominant genotype responsible for ND outbreaks in Asian countries. However, it clustered well apart from other isolates in this genotype to be considered a new subgenotype (VII-f).</p> <p>Conclusions</p> <p>These results revealed that this isolate was similar to virulent strains of NDV and was avirulent in BYP either due to resistance of local breeds or due to other factors such as substantial mutations in the HN protein. Furthermore, we have characterized the first isolate of NDV, which could act as domestic reference strain and could help in development and selection of appropriate strain of NDV for vaccine in the country.</p

    Combined treatment of adenoid cystic carcinoma with cetuximab and IMRT plus C12 heavy ion boost: ACCEPT [ACC, Erbitux® and particle therapy]

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    <p>Abstract</p> <p>Background</p> <p>Local control in adjuvant/definitive RT of adenoid cystic carcinoma (ACC) is largely dose-dependent leading to the establishment of particle therapy in this indication. However, even modern techniques leave space for improvement of local control by intensification of local treatment. Radiation sensitization by exploitation of high EGFR-expression in ACC with the EGFR receptor antibody cetuximab seems promising.</p> <p>Methods/design</p> <p>The ACCEPT trial is a prospective, mono-centric, phase I/II trial evaluating toxicity (primary endpoint: acute and late effects) and efficacy (secondary endpoint: local control, distant control, disease-free survival, overall survival) of the combined treatment with IMRT/carbon ion boost and weekly cetuximab in 49 patients with histologically proven (≥R1-resected, inoperable or Pn+) ACC. Patients receive 18 GyE carbon ions (6 fractions) and 54 Gy IMRT (2.0 Gy/fraction) in combination with weekly cetuximab throughout radiotherapy.</p> <p>Discussion</p> <p>The primary objective of ACCEPT is to evaluate toxicity and feasibility of cetuximab and particle therapy in adenoid cystic carcinoma.</p> <p>Trial Registration</p> <p>Clinical Trial Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01192087">NCT 01192087</a></p> <p>EudraCT number: 2010 - 022425 - 15</p

    Raster-scanned carbon ion therapy for malignant salivary gland tumors: acute toxicity and initial treatment response

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    <p>Abstract</p> <p>Background and purpose</p> <p>To investigate toxicity and efficacy in high-risk malignant salivary gland tumors (MSGT) of the head and neck. Local control in R2-resected adenoid cystic carcinoma was already improved with a combination of IMRT and carbon ion boost at only mild side-effects, hence this treatment was also offered to patients with MSGT and microscopic residual disease (R1) or perineural spread (Pn+).</p> <p>Methods</p> <p>From November 2009, all patients with MSGT treated with carbon ion therapy were evaluated. Acute side effects were scored according to CTCAE v.4.03. Tumor response was assessed according to RECIST where applicable.</p> <p>Results</p> <p>103 patients were treated from 11/2009 to 03/2011, median follow-up is 6 months. 60 pts received treatment following R2 resections or as definitive radiation, 43 patients received adjuvant radiation for R1 and/or Pn+. 16 patients received carbon ion treatment for re-irradiation. Median total dose was 73.2 GyE (23.9 GyE carbon ions + 49,9 Gy IMRT) for primary treatment and 44.9 GyE carbon ions for re-irradiation. All treatments were completed as planned and generally well tolerated with no > CTC°III toxicity. Rates of CTC°III toxicity (mucositis and dysphagia) were 8.7% with side-effects almost completely resolved at first follow-up.</p> <p>47 patients showed good treatment responses (CR/PR) according to RECIST.</p> <p>Conclusion</p> <p>Acute toxicity remains low in IMRT with carbon ion boost also in R1-resected patients and patients undergoing re-irradiation. R2-resected patients showed high rates of treatment response, though follow-up is too short to assess long-term disease control.</p

    RadioImmunotherapy for adenoid cystic carcinoma: a single-institution series of combined treatment with cetuximab

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    <p>Abstract</p> <p>Background</p> <p>Local control in adjuvant/definitive RT of adenoid cystic carcinoma (ACC) is largely dose-dependent. However, some clinical situations do not allow application of tumouricidal doses (i.e. re-irradiation) hence radiation sensitization by exploitation of high endothelial growth factor receptor (EGFR)-expression in ACC seems beneficial. This is a single-institution experience of combined radioimmunotherapy (RIT) with the EGFR-inhibitor cetuximab.</p> <p>Methods</p> <p>Between 2006 and 2010, 9 pts received RIT for advanced/recurrent ACC, 5/9 pts as re-irradiation. Baseline characteristics as well as treatment parameters were retrieved to evaluate efficacy and toxicity of the combination regimen were evaluated. Control rates (local/distant) and overall survival were calculated using Kaplan-Meier estimation.</p> <p>Results</p> <p>Median dose was 65 Gy, pts received a median of 6 cycles cetuximab. RIT was tolerated well with only one °III mucositis/dysphagia. Overall response/remission rates were high (77,8%); 2-year estimate of local control was 80% hence reaching local control levels comparable to high-dose RT. Progression-free survival (PFS) at 2 years and median overall survival were only 62,5% and 22,2 mo respectively.</p> <p>Conclusion</p> <p>While local control and treatment response in RIT seems promising, PFS and overall survival are still hampered by distant failure. The potential benefit of RIT with cetuximab warrants exploration in a prospective controlled clinical trial.</p

    S100A7-Downregulation Inhibits Epidermal Growth Factor-Induced Signaling in Breast Cancer Cells and Blocks Osteoclast Formation

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    S100A7 is a small calcium binding protein, which has been shown to be differentially expressed in psoriatic skin lesions, as well as in squamous cell tumors of the skin, lung and breast. Although its expression has been correlated to HER+ high-grade tumors and to a high risk of progression, the molecular mechanisms of these S100A7-mediated tumorigenic effects are not well known. Here, we showed for the first time that epidermal growth factor (EGF) induces S100A7 expression in both MCF-7 and MDA-MB-468 cell lines. We also observed a decrease in EGF-directed migration in shRNA-downregulated MDA-MB-468 cell lines. Furthermore, our signaling studies revealed that EGF induced simultaneous EGF receptor phosphorylation at Tyr1173 and HER2 phosphorylation at Tyr1248 in S100A7-downregulated cell lines as compared to the vector-transfected controls. In addition, reduced phosphorylation of Src at tyrosine 416 and p-SHP2 at tyrosine 542 was observed in these downregulated cell lines. Further studies revealed that S100A7-downregulated cells had reduced angiogenesis in vivo based on matrigel plug assays. Our results also showed decreased tumor-induced osteoclastic resorption in an intra-tibial bone injection model involving SCID mice. S100A7-downregulated cells had decreased osteoclast number and size as compared to the vector controls, and this decrease was associated with variations in IL-8 expression in in vitro cell cultures. This is a novel report on the role of S100A7 in EGF-induced signaling in breast cancer cells and in osteoclast formation

    The Short Non-Coding Transcriptome of the Protozoan Parasite Trypanosoma cruzi

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    The pathway for RNA interference is widespread in metazoans and participates in numerous cellular tasks, from gene silencing to chromatin remodeling and protection against retrotransposition. The unicellular eukaryote Trypanosoma cruzi is missing the canonical RNAi pathway and is unable to induce RNAi-related processes. To further understand alternative RNA pathways operating in this organism, we have performed deep sequencing and genome-wide analyses of a size-fractioned cDNA library (16–61 nt) from the epimastigote life stage. Deep sequencing generated 582,243 short sequences of which 91% could be aligned with the genome sequence. About 95–98% of the aligned data (depending on the haplotype) corresponded to small RNAs derived from tRNAs, rRNAs, snRNAs and snoRNAs. The largest class consisted of tRNA-derived small RNAs which primarily originated from the 3′ end of tRNAs, followed by small RNAs derived from rRNA. The remaining sequences revealed the presence of 92 novel transcribed loci, of which 79 did not show homology to known RNA classes

    Bone regeneration: current concepts and future directions

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    Bone regeneration is a complex, well-orchestrated physiological process of bone formation, which can be seen during normal fracture healing, and is involved in continuous remodelling throughout adult life. However, there are complex clinical conditions in which bone regeneration is required in large quantity, such as for skeletal reconstruction of large bone defects created by trauma, infection, tumour resection and skeletal abnormalities, or cases in which the regenerative process is compromised, including avascular necrosis, atrophic non-unions and osteoporosis. Currently, there is a plethora of different strategies to augment the impaired or 'insufficient' bone-regeneration process, including the 'gold standard' autologous bone graft, free fibula vascularised graft, allograft implantation, and use of growth factors, osteoconductive scaffolds, osteoprogenitor cells and distraction osteogenesis. Improved 'local' strategies in terms of tissue engineering and gene therapy, or even 'systemic' enhancement of bone repair, are under intense investigation, in an effort to overcome the limitations of the current methods, to produce bone-graft substitutes with biomechanical properties that are as identical to normal bone as possible, to accelerate the overall regeneration process, or even to address systemic conditions, such as skeletal disorders and osteoporosis

    Peripheral administration of lactate produces antidepressant-like effects.

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    In addition to its role as metabolic substrate that can sustain neuronal function and viability, emerging evidence supports a role for l-lactate as an intercellular signaling molecule involved in synaptic plasticity. Clinical and basic research studies have shown that major depression and chronic stress are associated with alterations in structural and functional plasticity. These findings led us to investigate the role of l-lactate as a potential novel antidepressant. Here we show that peripheral administration of l-lactate produces antidepressant-like effects in different animal models of depression that respond to acute and chronic antidepressant treatment. The antidepressant-like effects of l-lactate are associated with increases in hippocampal lactate levels and with changes in the expression of target genes involved in serotonin receptor trafficking, astrocyte functions, neurogenesis, nitric oxide synthesis and cAMP signaling. Further elucidation of the mechanisms underlying the antidepressant effects of l-lactate may help to identify novel therapeutic targets for the treatment of depression
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