417 research outputs found
The value of multimodality imaging for detection, characterisation and management of a wall adhering structure in the right atrium
The case presents a wall adherent structure in the right atrium in a young patient with peripheral tcell
lymphoma followed by successful prolonged lysis therapy resulting in the resolution of the
thrombus is presented. This case highlights the utility of multimodality imaging in an accurate
assessment of the right atrium thrombus and the effectiveness of prolonged lysis therapy.peer-reviewe
Adenomyoepithelial tumours and myoepithelial carcinomas of the breast – a spectrum of monophasic and biphasic tumours dominated by immature myoepithelial cells
BACKGROUND: Adenomyoepithelial tumours and myoepithelial carcinomas of the breast are primarily defined by the presence of neoplastic cells with a myoepithelial immunophenotype. Current classification schemes are based on purely descriptive features and an assessment of individual prognosis is still problematic. METHODS: A series of 27 adenomyoepithelial tumours of the breast was analysed immunohistochemically with antibodies directed against various cytokeratins, p63, smooth muscle alpha-actin (SMA) and vimentin. Additionally, double immunofluorescence and comparative genomic hybridisation (CGH) was performed. RESULTS: Immunohistochemically, all the tumours showed a constant expression of high molecular weight cytokeratins (Ck) Ck5 and Ck14, p63, SMA and vimentin. With exception of one case diagnosed as myoepithelial carcinoma, all tested tumours expressed low molecular weight cytokeratin Ck18 in variable proportions of cells. Even in monophasic tumours lacking obvious glandular differentiation in conventional staining, a number of neoplastic cells still expressed those cytokeratins. Double immunofluorescence revealed tumour cells exclusively staining for Ck5/Ck14 in the presence of other cell populations that co-expressed high molecular weight Ck5/Ck14 as well as either low molecular weight Ck8/18 or SMA. Based on morphology, we assigned the series to three categories, benign, borderline and malignant. This classification was supported by a stepwise increase in cytogenetic alterations on CGH. CONCLUSION: Adenomyoepithelial tumours comprise a spectrum of neoplasms consisting of an admixture of glandular and myoepithelial differentiation patterns. As a key component SMA-positive cells co-expressing cytokeratins could be identified. Although categorisation of adenomyoepithelial tumours in benign, borderline and malignant was supported by results of CGH, any assessment of prognosis requires to be firmly based on morphological grounds. At present it is not yet clear, if and to what extent proposed Ck5-positive progenitor cells contribute to the immunohistochemical and morphological heterogeneity of these neoplasms of the breast
An Analysis of Efficiency Improvements in Residential Sized Heat Pumps and Central Air Conditioners
This report summarizes: (1) the performance improvements
possible for central air conditioners and heat pumps using
conventional design improvements, (2) the development of a
methodology for estimating the seasonal performance of variable
speed heat pumps and air conditioners, and (3) the estimated
maximum efficiency levels that are technically feasible for
variable speed heat pumps and air conditioners. This report
builds on the work summarized in an earlier report from the
Energy Systems Laboratory[2]
Tet-on, or tet-off, that is the question: advanced conditional gene expression in Aspergillus
In Aspergillus, controlled gene expression is often achieved using the reverse tetracycline-controlled transactivator (rtTA) dependent Tet-on system, whereby transcription is activated in a titratable manner by addition of the tetracycline derivative doxycycline. The complementary Tet-off system utilises the tetracycline-controlled transactivator (tTA) component to quantitatively reduce gene expression. In this study, we utilised a synthetic biological approach to engineer highly optimised Tet-off conditional expression systems in Aspergillus niger and Aspergillus fumigatus. Steps for delivery of these tools include utilising codon optimised cassette components, testing several promoters for improved genetic stability and validating two modified luciferase reporters for highly accurate measurements of gene expression. The Tet-off cassettes developed in this study enable facile and quantitative functional analysis, as validated by Tet-off analysis of genes involved in chitin synthesis and cell wall polarity in A. niger, and para-aminobenzoic acid synthesis in A. fumigatus. We also used a racAG18V dominant allele to demonstrate that Tet-off in A. niger enables gene over-expression and downregulation in a single isolate. Additionally, we used the improved luciferase reporters to show that the Tet-off cassette in A. niger enables quantification of gene oscillations. In order to demonstrate that synthetic biological approaches developed here are broadly applicable to engineering transcriptional circuits in filamentous fungi, we used our strategy for improving cassette stability by promoter replacement in the A. niger Tet-on system, which resulted in a modified Tet-on cassette with higher stability in recipient genomes
Relevance and Recent Developments of Chitosan in Peripheral Nerve Surgery
Developments in tissue engineering yield biomaterials with different supporting strategies to promote nerve regeneration. One promising material is the naturally occurring chitin derivate chitosan. Chitosan has become increasingly important in various tissue engineering approaches for peripheral nerve reconstruction, as it has demonstrated its potential to interact with regeneration associated cells and the neural microenvironment, leading to improved axonal regeneration and less neuroma formation. Moreover, the physiological properties of its polysaccharide structure provide safe biodegradation behavior in the absence of negative side effects or toxic metabolites. Beneficial interactions with Schwann cells (SC), inducing differentiation of mesenchymal stromal cells to SC-like cells or creating supportive conditions during axonal recovery are only a small part of the effects of chitosan. As a result, an extensive body of literature addresses a variety of experimental strategies for the different types of nerve lesions. The different concepts include chitosan nanofibers, hydrogels, hollow nerve tubes, nerve conduits with an inner chitosan layer as well as hybrid architectures containing collagen or polyglycolic acid nerve conduits. Furthermore, various cell seeding concepts have been introduced in the preclinical setting. First translational concepts with hollow tubes following nerve surgery already transferred the promising experimental approach into clinical practice. However, conclusive analyses of the available data and the proposed impact on the recovery process following nerve surgery are currently lacking. This review aims to give an overview on the physiologic properties of chitosan, to evaluate its effect on peripheral nerve regeneration and discuss the future translation into clinical practice
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Possible Uses of Animal Databases for Further Statistical Evaluation and Modeling
Many studies have been performed in animals which mimic potential exposures of people in order to understand how factors modify radiation dose-response relationships. Cooperative analyses by investigators in different laboratories have a large potential for strengthening the conclusions that can be drawn from individual studies. When information on each animal is combined, then formal tests can be made to demonstrate that apparent consistencies or inconsistencies are statistically significant. Statistical methods must be carefully chosen so that differences between laboratories or studies can be controlled or described as part of the analysis in the interpretation of the conclusions. In this report, the example of bone cancer of the large number of studies of modifying factors for bone cancer available from studies in US and European laboratories
Results from the DELCODE study
Previous studies have demonstrated increased tau plasma levels in patients
with Alzheimer’s disease (AD) and mild cognitive impairment (MCI) due to AD.
Much less is known whether increased tau plasma levels can already be detected
in the pre-MCI stage of subjective cognitive decline (SCD). In the present
study we measured tau plasma levels in 111 SCD patients and 134 age- and
gender-matched cognitively healthy controls participating in the DZNE (German
Center for Neurodegenerative Diseases) longitudinal study on cognition and
dementia (DELCODE). Tau plasma levels were measured using ultra-sensitive,
single-molecule array (Simoa) technology. We found no significant different
tau plasma levels in SCD (3.4 pg/ml) compared with healthy controls (3.6
pg/ml) after controlling for age, gender, and education (p = 0.137). In
addition, tau plasma levels did not correlate with Aβ42 (r = 0.073; p =
0.634), tau (r = −0.179; p = 0.240), and p-tau181 (r = −0.208; p = 0.171)
cerebrospinal fluid (CSF) levels in a subgroup of 45 SCD patients with
available CSF. In conclusion, plasma tau is not increased in SCD patients. In
addition, the lack of correlation between tau in plasma and CSF in the
examined cohort suggests that tau levels are affected by different factors in
both biofluids
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