432 research outputs found

    The Search for Occult Metastatic Disease in Breast Cancer Patients: How Far Should We Go?

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41412/1/10434_2006_Article_10229.pd

    Conservation of core gene expression in vertebrate tissues

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    Abstract Background Vertebrates share the same general body plan and organs, possess related sets of genes, and rely on similar physiological mechanisms, yet show great diversity in morphology, habitat and behavior. Alteration of gene regulation is thought to be a major mechanism in phenotypic variation and evolution, but relatively little is known about the broad patterns of conservation in gene expression in non-mammalian vertebrates. Results We measured expression of all known and predicted genes across twenty tissues in chicken, frog and pufferfish. By combining the results with human and mouse data and considering only ten common tissues, we have found evidence of conserved expression for more than a third of unique orthologous genes. We find that, on average, transcription factor gene expression is neither more nor less conserved than that of other genes. Strikingly, conservation of expression correlates poorly with the amount of conserved nonexonic sequence, even using a sequence alignment technique that accounts for non-collinearity in conserved elements. Many genes show conserved human/fish expression despite having almost no nonexonic conserved primary sequence. Conclusions There are clearly strong evolutionary constraints on tissue-specific gene expression. A major challenge will be to understand the precise mechanisms by which many gene expression patterns remain similar despite extensive cis-regulatory restructuring

    Case Report: Dual nebulised antibiotics among adults with cystic fibrosis and chronic Pseudomonas infection [version 2; referees: 1 approved, 2 approved with reservations]

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    Pulmonary exacerbations in adults with cystic fibrosis (CF) and chronic Pseudomonas aeruginosa (Psae) infection are usually treated with dual intravenous antibiotics for 14 days, despite the lack of evidence for best practice. Intravenous antibiotics are commonly associated with various systemic adverse effects, including renal failure and ototoxicity. Inhaled antibiotics are less likely to cause systematic adverse effects, yet can achieve airway concentrations well above conventional minimum inhibitory concentrations. Typically one inhaled antibiotic is used at a time, but dual inhaled antibiotics (i.e. concomitant use of two different inhaled antibiotics) may have synergistic effect and achieve better results in the treatment of exacerbations. We presented anecdotal evidence for the use of dual inhaled antibiotics as an acute treatment for exacerbations, in the form of a case report. A female in her early thirties with CF and chronic Psae infection improved her FEV1 by 5% and 2% with two courses of dual inhaled antibiotics to treat exacerbations in 2016. In contrast, her FEV1 changed by 2%, –2%, 0% and 2%, respectively, with four courses of dual intravenous antibiotics in 2016. Baseline FEV1 was similar prior to all six courses of treatments. The greater FEV1 improvements with dual inhaled antibiotics compared to dual intravenous antibiotics suggest the potential role of using dual inhaled antibiotics to treat exacerbations among adults with CF and chronic Psae infection, especially since a greater choice of inhaled anti-pseudomonal antibiotics is now available. A previous study in 1985 has looked at the concomitant administration of inhaled tobramycin and carbenicillin, by reconstituting antibiotics designed for parenteral administration. To our knowledge, this is the first literature to describe the concomitant use of two different antibiotics specifically developed for delivery via the inhaled route

    Cellular localization, accumulation and trafficking of double-walled carbon nanotubes in human prostate cancer cells

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    Carbon nanotubes (CNTs) are at present being considered as potential nanovectors with the ability to deliver therapeutic cargoes into living cells. Previous studies established the ability of CNTs to enter cells and their therapeutic utility, but an appreciation of global intracellular trafficking associated with their cellular distribution has yet to be described. Despite the many aspects of the uptake mechanism of CNTs being studied, only a few studies have investigated internalization and fate of CNTs inside cells in detail. In the present study, intracellular localization and trafficking of RNA-wrapped, oxidized double-walled CNTs (oxDWNT–RNA) is presented. Fixed cells, previously exposed to oxDWNT–RNA, were subjected to immunocytochemical analysis using antibodies specific to proteins implicated in endocytosis; moreover cell compartment markers and pharmacological inhibitory conditions were also employed in this study. Our results revealed that an endocytic pathway is involved in the internalization of oxDWNT–RNA. The nanotubes were found in clathrin-coated vesicles, after which they appear to be sorted in early endosomes, followed by vesicular maturation, become located in lysosomes. Furthermore, we observed co-localization of oxDWNT–RNA with the small GTP-binding protein (Rab 11), involved in their recycling back to the plasma membrane via endosomes from the trans-golgi network

    Objectively measured time spent sedentary is associated with insulin resistance independent of overall and central body fat in 9- to 10-year-old Portuguese children

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    OBJECTIVE — We examined the independent relationships between objectively measured physical activity and insulin resistance in Portuguese children. RESEARCH DESIGN AND METHODS — This is a school-based, cross-sectional study in 147 randomly selected girls (aged 9.8 0.3 years; 27.8 9.3% body fat) and 161 boys (aged 9.8 0.3 years; 22.0 9.2% body fat). Physical activity was assessed by the Actigraph accel erometer for 4 days and summarized as time spent sedentary (accelerometer counts 500/min), in light-intensity (accelerometer counts 500–2,000/min), and in moderate- and vigorous intensity activity (accelerometer counts 2,001/min). We measured total and central fat mass by dual-energy X-ray absorptiometry. Insulin resistance was expressed as the homeostasis model assessment score. RESULTS — Time (min/day) spent sedentary was significantly and positively associated with insulin resistance ( -coefficient 0.001 [95% CI 0.0002–0.002]; P 0.013). Time spent in moderate- and vigorous-intensity physical activity ( 0.002 [ 0.003 to 0.001]; P 0.0009) and overall physical activity ( 0.001 [ 0.008 to 0.003]; P 0.0001) were significantly and inversely associated with insulin resistance. All associations remained statistically significant, although they were attenuated after further adjustments for sex, birth weight, sexual maturity, and total or central fat mass (P 0.03). CONCLUSIONS — Physical activity is associated with insulin resistance independent of total and central fat mass in children. Our results emphasize the importance of decreasing sedentary behavior and increasing time spent in moderate- and vigorous-intensity activity in children, which may have beneficial effects on metabolic risk factors regardless of the degree of adiposity.info:eu-repo/semantics/publishedVersio

    Pituitary tumor-transforming gene expression is a prognostic marker for tumor recurrence in squamous cell carcinoma of the head and neck

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    BACKGROUND: The proto-oncogene pituitary tumor-transforming gene (PTTG) has been shown to be abundantly overexpressed in a large variety of neoplasms likely promoting neo-vascularization and tumor invasiveness. In this study, we investigated a potential role for PTTG mRNA expression as a marker to evaluate the future clinical outcome of patients diagnosed with primary cancer of the head and neck. METHODS: Tumor samples derived from primary tumors of 89 patients suffering from a squamous cell carcinoma were analyzed for PTTG mRNA-expression and compared to corresponding unaffected tissue. Expression levels were correlated to standard clinico-pathological parameters based on a five year observation period. RESULTS: In almost all 89 tumor samples PTTG was found to be overexpressed (median fold increase: 2.1) when compared to the unaffected tissue specimens derived from the same patient. The nodal stage correlated with PTTG transcript levels with significant differences between pN0 (median expression: 1.32) and pN+ (median expression: 2.12; P = 0.016). In patients who developed a tumor recurrence we detected a significantly higher PTTG expression in primary tumors (median expression: 2.63) when compared to patients who did not develop a tumor recurrence (median expression: 1.29; P = 0.009). Since the median expression of PTTG in patients with tumor stage T1/2N0M0 that received surgery alone without tumor recurrence was 0.94 versus 3.82 in patients suffering from a tumor recurrence (P = 0.006), PTTG expression might provide a feasible mean of predicting tumor recurrence. CONCLUSION: Elevated PTTG transcript levels might be used as a prognostic biomarker for future clinical outcome (i.e. recurrence) in primary squamous cell carcinomas of the head and neck, especially in early stages of tumor development

    Mutations in Rb1 pathway-related genes are associated with poor prognosis in Anaplastic Astrocytomas

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    Anaplastic astrocytoma (AA, WHO grade III) is, second to Glioblastoma, the most common and most malignant type of adult CNS tumour. Since survival for patients with AA varies markedly and there are no known useful prognostic or therapy response indicators, the primary purpose of this study was to examine whether knowledge of the known genetic abnormalities found in AA had any clinical value. The survival data on 37 carefully sampled AA was correlated with the results of a detailed analysis of the status of nine genes known to be involved in the development of astrocytic tumours. These included three genes coding for proteins in the p53 pathway (TP53, p14ARF and MDM2), four in the Rb1 pathway (CDKN2A, CDKN2B, RB1 and CDK4) and PTEN and EGFR. We found that loss of both wild-type copies of any of the three tumour suppressor genes CDKN2A, CDKN2B and RB1 or gene amplification of CDK4, disrupting the Rb1 pathway, were associated with shorter survival (P=0.009). This association was consistent in multivariate analysis, including adjustment for age (P=0.013). The findings suggest that analysis of the genes coding for Rb1 pathway components provides additional prognostic information in AA patients receiving conventional therapy

    Development of transgenic rats producing human β-amyloid precursor protein as a model for Alzheimer's disease: Transgene and endogenous APP genes are regulated tissue-specifically

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    <p>Abstract</p> <p>Background</p> <p>Alzheimer's disease (AD) is a devastating neurodegenerative disorder that affects a large and growing number of elderly individuals. In addition to idiopathic disease, AD is also associated with autosomal dominant inheritance, which causes a familial form of AD (FAD). Some instances of FAD have been linked to mutations in the β-amyloid protein precursor (APP). Although there are numerous mouse AD models available, few rat AD models, which have several advantages over mice, have been generated.</p> <p>Results</p> <p>Fischer 344 rats expressing human APP driven by the ubiquitin-C promoter were generated via lentiviral vector infection of Fischer 344 zygotes. We generated two separate APP-transgenic rat lines, APP21 and APP31. Serum levels of human amyloid-beta (Aβ)<sub>40 </sub>were 298 pg/ml for hemizygous and 486 pg/ml for homozygous APP21 animals. Serum Aβ<sub>42 </sub>levels in APP21 homozygous rats were 135 pg/ml. Immunohistochemistry in brain showed that the human APP transgene was expressed in neurons, but not in glial cells. These findings were consistent with independent examination of enhanced green fluorescent protein (eGFP) in the brains of eGFP-transgenic rats. APP21 and APP31 rats expressed 7.5- and 3-times more APP mRNA, respectively, than did wild-type rats. Northern blots showed that the human APP transgene, driven by the ubiquitin-C promoter, is expressed significantly more in brain, kidney and lung compared to heart and liver. A similar expression pattern was also seen for the endogenous rat APP. The unexpected similarity in the tissue-specific expression patterns of endogenous rat APP and transgenic human APP mRNAs suggests regulatory elements within the cDNA sequence of APP.</p> <p>Conclusion</p> <p>This manuscript describes the generation of APP-transgenic inbred Fischer 344 rats. These are the first human AD model rat lines generated by lentiviral infection. The APP21 rat line expresses high levels of human APP and could be a useful model for AD. Tissue-specific expression in the two transgenic rat lines and in wild-type rats contradicts our current understanding of APP gene regulation. Determination of the elements that are responsible for tissue-specific expression of APP may enable new treatment options for AD.</p

    Influence of packing density and surface roughness of vertically-aligned carbon nanotubes on adhesive properties of gecko-inspired mimetics.

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    We have systematically studied the macroscopic adhesive properties of vertically aligned nanotube arrays with various packing density and roughness. Using a tensile setup in shear and normal adhesion, we find that there exists a maximum packing density for nanotube arrays to have adhesive properties. Too highly packed tubes do not offer intertube space for tube bending and side-wall contact to surfaces, thus exhibiting no adhesive properties. Likewise, we also show that the surface roughness of the arrays strongly influences the adhesion properties and the reusability of the tubes. Increasing the surface roughness of the array strengthens the adhesion in the normal direction, but weakens it in the shear direction. Altogether, these results allow progress toward mimicking the gecko's vertical mobility.The authors acknowledge funding from the EC project Technotubes.This is the accepted manuscript. The final version is available at http://pubs.acs.org/doi/abs/10.1021/am507822b
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