648 research outputs found
Sialyl Lewis x expression in canine malignant mammary tumours: correlation with clinicopathological features and E-Cadherin expression
<p>Abstract</p> <p>Background</p> <p>Sialyl Lewis x (sLe<sup>x</sup>) antigen is a carbohydrate antigen that is considered not only a marker for cancer but also implicated functionally in the malignant behaviour of cancer cells. Overexpression of sLe<sup>x </sup>is associated with enhanced progression and metastases of many types of cancer including those of the mammary gland. Canine mammary tumours can invade and give rise to metastases via either lymphatic or blood vessels.</p> <p>E-Cadherin is specifically involved in epithelial cell-to-cell adhesion. In cancer, E-Cadherin underexpression is one of the alterations that characterizes the invasive phenotype and is considered an invasion/tumour suppressor gene. Partial or complete loss of E-Cadherin expression correlates with poor prognosis in canine malignant mammary cancer.</p> <p>The aim of this study was to analyse the sLe<sup>x </sup>expression in canine malignant mammary tumours and to evaluate if the presence of sLe<sup>x </sup>correlates with the expression of E-Cadherin and with clinicopathological features.</p> <p>Methods</p> <p>Fifty-three cases of canine mammary carcinomas were analysed immunohistochemically using monoclonal antibodies against sLe<sup>x </sup>(IgM) and E-Cadherin (IgG). The clinicopathological data were then assessed to determine whether there was a correlation with sLe<sup>x </sup>tumour expression. Double labelled immunofluorescence staining was performed to analyse the combined expression of sLe<sup>x </sup>and E-Cadherin.</p> <p>Results</p> <p>sLe<sup>x </sup>expression was consistently demonstrated in all cases of canine mammary carcinomas with different levels of expression. We found a significant relationship between the levels of sLe<sup>x </sup>expression and the presence of lymph node metastases. We also demonstrated that when E-Cadherin expression was increased sLe<sup>x </sup>was reduced and vice-versa. The combined analysis of both adhesion molecules revealed an inverse relationship.</p> <p>Conclusion</p> <p>In the present study we demonstrate the importance of sLe<sup>x </sup>in the malignant phenotype of canine malignant mammary tumours. Our results support the use of sLe<sup>x </sup>as a prognostic tumour marker in canine mammary carcinomas. Furthermore, we showed that sLe<sup>x </sup>and E-Cadherin expression were inversely correlated. Future studies are warranted to clarify the molecular mechanism underlying the relation between sLe<sup>x </sup>and E-Cadherin in canine mammary carcinoma cells which represents an important comparative model to woman breast cancer.</p
Recommended from our members
Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios
The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air–sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961–2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001–2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air–sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070–2099 period compared to 1961–1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in General Circulation Models, has the largest impact on the evolution of the Mediterranean water masses, followed by the choice of the socio-economic scenario. The choice of river runoff and atmospheric forcing both have a smaller impact. The state of the MTHC during the historical period is found to have a large influence on the transfer of surface anomalies toward depth. Besides, subsurface currents are substantially modified in the Ionian Sea and the Balearic region. Finally, the response of thermosteric sea level ranges from +34 to +49 cm (2070–2099 vs. 1961–1990), mainly depending on the Atlantic forcing
Ex vivo analysis of the debris remaining in flattened root canals of vital and nonvital teeth after biomechanical preparation with Ni-Ti rotary instruments
Discovering privileged topologies of molecular knots with self-assembling models
Despite the several available strategies to build complex supramolecular constructs, only a handful of different molecular knots have been synthesised so far. Here, in response to the quest for further designable topologies, we use Monte Carlo sampling and molecular dynamics simulations, informed by general principles of supramolecular assembly, as a discovery tool for thermodynamically and kinetically accessible knot types made of helical templates. By combining this approach with the exhaustive enumeration of molecular braiding patterns applicable to more general template geometries, we find that only few selected shapes have the closed, symmetric and quasi-planar character typical of synthetic knots. The corresponding collection of admissible topologies is extremely restricted. It covers all known molecular knots but it especially includes a limited set of novel complex ones that have not yet been obtained experimentally, such as 10124 and 15n41185, making them privileged targets for future self-assembling experiments
A Genome-Wide Survey of Imprinted Genes in Rice Seeds Reveals Imprinting Primarily Occurs in the Endosperm
Genomic imprinting causes the expression of an allele depending on its parental origin. In plants, most imprinted genes have been identified in Arabidopsis endosperm, a transient structure consumed by the embryo during seed formation. We identified imprinted genes in rice seed where both the endosperm and embryo are present at seed maturity. RNA was extracted from embryos and endosperm of seeds obtained from reciprocal crosses between two subspecies Nipponbare (Japonica rice) and 93-11 (Indica rice). Sequenced reads from cDNA libraries were aligned to their respective parental genomes using single-nucleotide polymorphisms (SNPs). Reads across SNPs enabled derivation of parental expression bias ratios. A continuum of parental expression bias states was observed. Statistical analyses indicated 262 candidate imprinted loci in the endosperm and three in the embryo (168 genic and 97 non-genic). Fifty-six of the 67 loci investigated were confirmed to be imprinted in the seed. Imprinted loci are not clustered in the rice genome as found in mammals. All of these imprinted loci were expressed in the endosperm, and one of these was also imprinted in the embryo, confirming that in both rice and Arabidopsis imprinted expression is primarily confined to the endosperm. Some rice imprinted genes were also expressed in vegetative tissues, indicating that they have additional roles in plant growth. Comparison of candidate imprinted genes found in rice with imprinted candidate loci obtained from genome-wide surveys of imprinted genes in Arabidopsis to date shows a low degree of conservation, suggesting that imprinting has evolved independently in eudicots and monocots
Evapotranspiração e coeficientes de cultivo da beterraba orgânica sob cobertura morta de leguminosa e gramínea.
As práticas agrícolas que maximizam a produtividade e o uso da água são de vital importância para a agricultura. Assim, foram testados três tipos de manejo do solo com objetivo de determinar a evapotranspiração (ETc) e os coeficientes de cultivo (kc) da beterraba. Os tipos de manejo foram a utilização de coberturas mortas vegetais, denominadas capim cameroon (Pennisetum purpureum), gliricídia (Gliricidia sepium) e solo sem cobertura morta em área experimental do SIPA (Sistema Integrado de Produção Orgânica) localizado em Seropédica, Brasil. A lâmina de irrigação foi estimada com base no balanço de água no solo, cujo monitoramento foi realizado com a técnica da TDR. As ETc acumuladas para a cultura da beterraba foram 59,41; 55,31 e 119,62 mm, respectivamente, para capim cameroon, gliricídia e solo sem cobertura morta. A evapotranspiração de referência (ETo) foi obtida por meio do modelo de Penamn-Monteith. Os valores médios de kc obtidos para as fases inicial, média e final de desenvolvimento foram de 0,39; 0,42 e 1,02; 0,79; 0,76 e 1,18; e 0,56; 0,61 e 0,84, respectivamente, para capim cameroon, gliricídia e solo sem cobertura morta. O uso da cobertura do solo com gramínea ou leguminosa minimizou de forma expressiva a demanda hídrica da cultura da beterraba (Beta vulgaris)
Preclinical animal research on therapy dosimetry with dual isotopes
Preclinical research into radionuclide therapies based on radiation dosimetry will enable the use of any LET-equivalent radionuclide. Radiation dose and dose rate have significant influence on dose effects in the tumour depending on its radiation sensitivity, possibilities for repair of sublethal damage, and repopulation during or after the therapy. Models for radiation response of preclinical tumour models after peptide receptor radionuclide therapy based on the linear quadratic model are presented. The accuracy of the radiation dose is very important for observation of dose-effects. Uncertainties in the radiation dose estimation arise from incomplete assay of the kinetics, low accuracy in volume measurements and absorbed dose S-values for stylized models instead of the actual animal geometry. Normal dose uncertainties in the order of 20% might easily make the difference between seeing a dose-effect or missing it altogether. This is true for the theoretical case of a homogeneous tumour type behaving in vivo in the same way as its cells do in vitro. Heterogeneity of tumours induces variations in clonogenic cell density, radiation sensitivity, repopulation capacity and repair kinetics. The influence of these aspects are analysed within the linear quadratic model for tumour response to radionuclide therapy. Preclinical tumour models tend to be less heterogenic than the clinical conditions they should represent. The results of various preclinical radionuclide therapy experiments for peptide receptor radionuclide therapy are compared to the outcome of theoretical models and the influence of increased heterogeneity is analysed when the results of preclinical research is transferred to the clinic. When the radiation dose and radiobiology of the tumour response is known well enough it may be possible to leave the current phenomenological approach in preclinical radionuclide therapy and start basing these experiments on radiation dose. Then the use of a gamma ray-emitting radionuclides for a chemically comparable beta-particle-emitting paired isotope for therapy evaluation would be feasible
How useful is the assessment of lymphatic vascular density in oral carcinoma prognosis?
Abstract
Background
Lymphatic vessels are major routes for metastasis in head and neck squamous cell carcinoma (HNSCC), but lymphatic endothelial cells (LECs) are difficult to recognize in tumor histological sections. D2-40 stains podoplanin, a molecule expressed in LECs, however, the potential prognostic usefulness of this molecule is not completely understood in HNSCC. We aimed to investigate the value of assessing peritumoral and intratumoral lymphatic vessel density (LVD) as prognostic marker for HNSCC.
Methods
Thirty-one cases of HNSCC were stained for D2-40 and CD31. LVD and blood vessel density (BVD) were assessed by counting positive reactions in 10 hotspot areas at ×200 magnification.
Results
D2-40 was specific for lymphatic vessels and did not stain blood vascular endothelial cells. LECs showed more tortuous and disorganized structure in intratumoral lymphatic vessels than in peritumoral ones. No statistical differences were observed between peritumoral-LVD and intratumoral-LVD or between peritumoral-BVD and intratumoral-BVD. Tumor D2-40 staining was positively associated with lymphatic vessel invasion (p = 0.011).
Conclusion
LVD is a powerful marker for HNSCC prognosis. We found significant differences in peritumoral and intratumoral D2-40 immunoreactivity, which could have important implications in future therapeutic strategies and outcome evaluation
Does the use of the 2009 FIGO classification of endometrial cancer impact on indications of the sentinel node biopsy?
<p>Abstract</p> <p>Background</p> <p>Lymphadenectomy is debated in early stages endometrial cancer. Moreover, a new FIGO classification of endometrial cancer, merging stages IA and IB has been recently published. Therefore, the aims of the present study was to evaluate the relevance of the sentinel node (SN) procedure in women with endometrial cancer and to discuss whether the use of the 2009 FIGO classification could modify the indications for SN procedure.</p> <p>Methods</p> <p>Eighty-five patients with endometrial cancer underwent the SN procedure followed by pelvic lymphadenectomy. SNs were detected with a dual or single labelling method in 74 and 11 cases, respectively. All SNs were analysed by both H&E staining and immunohistochemistry. Presumed stage before surgery was assessed for all patients based on MR imaging features using the 1988 FIGO classification and the 2009 FIGO classification.</p> <p>Results</p> <p>An SN was detected in 88.2% of cases (75/85 women). Among the fourteen patients with lymph node metastases one-half were detected by serial sectioning and immunohistochemical analysis. There were no false negative case. Using the 1988 FIGO classification and the 2009 FIGO classification, the correlation between preoperative MRI staging and final histology was moderate with Kappa = 0.24 and Kappa = 0.45, respectively. None of the patients with grade 1 endometrioid carcinoma on biopsy and IA 2009 FIGO stage on MR imaging exhibited positive SN. In patients with grade 2-3 endometrioid carcinoma and stage IA on MR imaging, the rate of positive SN reached 16.6% with an incidence of micrometastases of 50%.</p> <p>Conclusions</p> <p>The present study suggests that sentinel node biopsy is an adequate technique to evaluate lymph node status. The use of the 2009 FIGO classification increases the accuracy of MR imaging to stage patients with early stages of endometrial cancer and contributes to clarify the indication of SN biopsy according to tumour grade and histological type.</p
- …