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1.
Res Vet Sci ; 152: 307-313, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36084372

RESUMO

Human inflammatory breast cancer (IBC) and canine inflammatory mammary cancer (IMC) are the most aggressive and lethal types of mammary tumors with specific characteristics such as exacerbated angiogenesis, lymphangiogenesis and lymphangiotropism. E-cadherin expression is another specific feature of IBC not previously studied in canine IMC. In this study, the expression of E-cadherin and CADM1 (Cell Adhesion molecule 1) and their possible role as key molecules involved in the pathogenesis of IMC were immunohistochemically analyzed in 19 canine IMC and 15 grade III non-IMC cases. E-cadherin and CADM1 expression was higher in IMC cases (p = 0.002, p = 0.008, respectively). In the IMC group, E-cadherin cytoplasmic immunolabeling was more frequent (p = 0.035) and it was associated to the expression of the angiogenic and lymphangiogenic factors COX-2 (p = 0.009), VEGF-A (p = 0.031) and VEGF-D (p = 0.008). The differential mRNA expression between IMC and non-IMC was studied by microarray analysis in 6 cases. E-cadherin gene (CDH1) was not up-regulated in IMC cases at a transcriptional level; interestingly CADM1 was 7-fold upregulated. The differential expression of E-cadherin protein in IMC suggests a possible role of E-cadherin in the characteristic exacerbated angiogenesis and lymphangiogenesis and further support IMC as a natural model for the study of human IBC. Future studies in IBC and IMC including a broad panel of adhesion molecules are necessary to elucidate their role in the metastatic process and angiogenesis.


Assuntos
Doenças do Cão , Neoplasias Inflamatórias Mamárias , Neoplasias Mamárias Animais , Animais , Cães , Caderinas/genética , Caderinas/metabolismo , Molécula 1 de Adesão Celular/genética , Doenças do Cão/metabolismo , Neoplasias Inflamatórias Mamárias/metabolismo , Neoplasias Inflamatórias Mamárias/patologia , Neoplasias Inflamatórias Mamárias/veterinária , Neoplasias Mamárias Animais/patologia , Neovascularização Patológica/patologia , Neovascularização Patológica/veterinária
2.
Front Appl Math Stat ; 7: 650716, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34336986

RESUMO

The COVID-19 pandemic has had worldwide devastating effects on human lives, highlighting the need for tools to predict its development. The dynamics of such public-health threats can often be efficiently analyzed through simple models that help to make quantitative timely policy decisions. We benchmark a minimal version of a Susceptible-Infected-Removed model for infectious diseases (SIR) coupled with a simple least-squares Statistical Heuristic Regression (SHR) based on a lognormal distribution. We derive the three free parameters for both models in several cases and test them against the amount of data needed to bring accuracy in predictions. The SHR model is ≈ ±2% accurate about 20 days past the second inflexion point in the daily curve of cases, while the SIR model reaches a similar accuracy a fortnight before. All the analyzed cases assert the utility of SHR and SIR approximants as a valuable tool to forecast the disease's evolution. Finally, we have studied simulated stochastic individual-based SIR dynamics, which yields a detailed spatial and temporal view of the disease that cannot be given by SIR or SHR methods.

3.
Astron Astrophys ; 6372020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32508346

RESUMO

Chemical equilibrium has proven extremely useful for predicting the chemical composition of AGB atmospheres. Here we use a recently developed code and an updated thermochemical database that includes gaseous and condensed species involving 34 elements to compute the chemical equilibrium composition of AGB atmospheres of M-, S-, and C-type stars. We include for the first time Ti x C y clusters, with x = 1-4 and y = 1-4, and selected larger clusters ranging up to Ti13C22, for which thermochemical data are obtained from quantum-chemical calculations. Our main aims are to systematically survey the main reservoirs of each element in AGB atmospheres, review the successes and failures of chemical equilibrium by comparing it with the latest observational data, identify potentially detectable molecules that have not yet been observed, and diagnose the most likely gas-phase precursors of dust and determine which clusters might act as building blocks of dust grains. We find that in general, chemical equilibrium reproduces the observed abundances of parent molecules in circumstellar envelopes of AGB stars well. There are, however, severe discrepancies of several orders of magnitude for some parent molecules that are observed to be anomalously overabundant with respect to the predictions of chemical equilibrium. These are HCN, CS, NH3, and SO2 in M-type stars, H2O and NH3 in S-type stars, and the hydrides H2O, NH3, SiH4, and PH3 in C-type stars. Several molecules have not yet been observed in AGB atmospheres but are predicted with non-negligible abundances and are good candidates for detection with observatories such as ALMA. The most interesting ones are SiC5, SiNH, SiCl, PS, HBO, and the metal-containing molecules MgS, CaS, CaOH, CaCl, CaF, ScO, ZrO, VO, FeS, CoH, and NiS. In agreement with previous studies, the first condensates predicted to appear in C-rich atmospheres are found to be carbon, TiC, and SiC, while Al2O3 is the first major condensate expected in O-rich outflows. According to our chemical equilibrium calculations, the gas-phase precursors of carbon dust are probably acetylene, atomic carbon, and/or C3, while for silicon carbide dust, the most likely precursors are the molecules SiC2 and Si2C. In the case of titanium carbide dust, atomic Ti is the major reservoir of this element in the inner regions of AGB atmospheres, and therefore it is probably the main supplier of titanium during the formation of TiC dust. However, chemical equilibrium predicts that large titanium-carbon clusters such as Ti8C12 and Ti13C22 become the major reservoirs of titanium at the expense of atomic Ti in the region where condensation of TiC is expected to occur. This suggests that the assembly of large Ti x C y clusters might be related to the formation of the first condensation nuclei of TiC. In the case of Al2O3 dust, chemical equilibrium indicates that atomic Al and the carriers of Al-O bonds AlOH, AlO, and Al2O are the most likely gas-phase precursors.

4.
Vet Comp Oncol ; 16(1): 148-158, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28589573

RESUMO

The aim was to study the effects of flutamide on cell proliferation, in vivo tumour growth and steroid production in canine and human IBC cell lines. IPC-366 and SUM149 cell cultures were exposed to flutamide concentrations for 72 hours. Additionally, IPC-366 and SUM149 xenotransplanted mice were treated subcutaneously with flutamide 3 times a week for 2 weeks. Steroid hormones determination in culture media, serum and tumour homogenates (pregnenolone, progesterone, androstenedione, testosterone, dihydrotestosterone, 17ß-oestradiol and oestrone sulphate) were assayed by EIA. in vitro cell proliferation percentages showed a decrease in all flutamide dosages in IPC-366 and SUM149. in vivo flutamide reduced tumour size by 55% to 65%, and metastasis rates decreased. In treated groups, androgen levels in culture media, serum and tumour homogenates were increased as oestrogen levels decreased. These results suggest that flutamide treatment inhibits cell proliferation and promotes tumour reduction by increasing androgen levels and also support future therapy approaches.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Doenças do Cão/tratamento farmacológico , Flutamida/uso terapêutico , Hormônios Esteroides Gonadais/metabolismo , Neoplasias Mamárias Animais/tratamento farmacológico , Neoplasias Mamárias Experimentais/tratamento farmacológico , Androstenodiona/metabolismo , Animais , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Di-Hidrotestosterona/metabolismo , Cães , Estradiol/metabolismo , Estrona/análogos & derivados , Estrona/metabolismo , Feminino , Humanos , Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Experimentais/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Pregnenolona/metabolismo , Progesterona/metabolismo , Testosterona/metabolismo
5.
Colorectal Dis ; 2017 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-29211327

RESUMO

A correct preoperative strategy is crucial when surgery is needed for retrorectal tumours (RRT).[1] Surgical approaches may be purely anterior-abdominal, posterior-sacrococcygeal or combined depending on the tumour's size and location.[2] We present the case of an 18-year-old female with Currarino Syndrome who underwent surgery by a combined abdominal laparoscopic-posterior Kraske approach for the resection of a large RRT. This article is protected by copyright. All rights reserved.

6.
J Phys Condens Matter ; 29(11): 115001, 2017 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-28155852

RESUMO

We have developed a calculation scheme for the elastic electron current in ultra-thin epitaxial heterostructures. Our model uses a Keldysh's non-equilibrium Green's function formalism and a layer-by-layer construction of the epitaxial film. Such an approach is appropriate to describe the current in a ballistic electron emission microscope (BEEM) where the metal base layer is ultra-thin and generalizes a previous one based on a decimation technique appropriated for thick slabs. This formalism allows a full quantum mechanical description of the transmission across the epitaxial heterostructure interface, including multiple scattering via the Dyson equation, which is deemed a crucial ingredient to describe interfaces of ultra-thin layers properly in the future. We introduce a theoretical formulation needed for ultra-thin layers and we compare with results obtained for thick Au(1 1 1) metal layers. An interesting effect takes place for a width of about ten layers: a BEEM current can propagate via the center of the reciprocal space ([Formula: see text]) along the Au(1 1 1) direction. We associate this current to a coherent interference finite-width effect that cannot be found using a decimation technique. Finally, we have tested the validity of the handy semiclassical formalism to describe the BEEM current.

7.
Vet Comp Oncol ; 15(3): 980-995, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27146723

RESUMO

Inflammatory breast cancer (IBC) is an aggressive type of cancer with poor survival in women. Inflammatory mammary cancer (IMC) in dogs is very similar to human IBC and it has been proposed as a good surrogate model for study the human disease. The aim was to determine if IPC-366 shared characteristics with the IBC cell line SUM149. The comparison was conducted in terms of ability to grow (adherent and nonadherent conditions), stem cell markers expression using flow cytometry, protein production using western blot and tumorigenic capacity. Our results revealed that both are capable of forming long-term mammospheres with a grape-like morphology. Adherent and nonadherent cultures exhibited fast growth in vivo. Stem cell markers expressions showed that IPC-366 and SUM149 in adherent and nonadherent conditions has mesenchymal-like characteristics, E-cadherin and N-cadherin, was higher in adherent than in nonadherent cultures. Therefore, this study determines that both cell lines are similar and IPC-366 is a good model for the human and canine disease.


Assuntos
Neoplasias Mamárias Animais/patologia , Animais , Western Blotting/veterinária , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Cães , Feminino , Citometria de Fluxo/veterinária
9.
Reprod Domest Anim ; 51(2): 269-75, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26899138

RESUMO

Canine inflammatory mammary cancer (IMC) has been proposed as a model for the study of human inflammatory breast cancer (IBC). The aims of this study were to compare the immunohistochemical expression of aromatase (Arom) and several hormone receptors [estrogen receptor α (ERα), estrogen receptor ß (ERß), progesterone receptor (PR) and androgen receptor (AR)], in 21 IMC cases vs 19 non-IMC; and to study the possible effect of letrozole on canine IMC and human inflammatory breast cancer (IBC) in vitro using IPC-366 and SUM-149 cell lines. Significant elevations of the means of Arom Total Score (TS), ERß TS and PR TS were found in the IMC group (p = 0.025, p = 0.038 and p = 0.037, respectively). Secondary IMC tumours expressed higher levels of Arom than primary IMC (p = 0.029). Non-IMC PR- tumours contained higher levels of Arom than non-IMC PR+ tumours (p = 0.007). After the addition of letrozole, the number of IMC and IBC cells dropped drastically. The overexpression of Arom found and the results obtained in vitro further support canine IMC as a model for the study of IBC and future approaches to the treatment of dogs with mammary cancer, and especially IMC, using Arom inhibitors.


Assuntos
Aromatase/metabolismo , Doenças do Cão/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Neoplasias Mamárias Animais/enzimologia , Receptores de Esteroides/metabolismo , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Aromatase/genética , Linhagem Celular Tumoral , Sobrevivência Celular , Cães , Feminino , Letrozol , Neoplasias Mamárias Animais/metabolismo , Nitrilas/administração & dosagem , Nitrilas/farmacologia , Receptores de Esteroides/genética , Triazóis/administração & dosagem , Triazóis/farmacologia
10.
Langmuir ; 31(1): 233-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25486105

RESUMO

The hydrogen (H) dimer structures formed upon room-temperature H adsorption on single layer graphene (SLG) grown on SiC(0001) are addressed using a combined theoretical-experimental approach. Our study includes density functional theory (DFT) calculations for the full (6√3 × 6√3)R30° unit cell of the SLG/SiC(0001) substrate and atomically resolved scanning tunneling microscopy images determining simultaneously the graphene lattice and the internal structure of the H adsorbates. We show that H atoms normally group in chemisorbed coupled structures of different sizes and orientations. We make an atomic scale determination of the most stable experimental geometries, the small dimers and ellipsoid-shaped features, and we assign them to hydrogen adsorbed in para dimers and ortho dimers configuration, respectively, through comparison with the theory.


Assuntos
Grafite/química , Hidrogênio/química , Teoria Quântica , Dimerização , Microscopia de Tunelamento
11.
Vet Pathol ; 50(1): 94-105, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22688585

RESUMO

In this prospective study, a canine-adapted histological grading method was compared with histopathological and clinical characteristics and was evaluated as a prognostic indicator in canine mammary carcinomas (CMCs). Recruited dogs with at least 1 malignant mammary tumor (n = 65) were clinically evaluated, surgically treated, and followed up (minimum follow-up 28 months, maximum 38 months). Histopathological diagnoses were performed according to Goldschmidt et al (2011). Tumors were graded as grade I (29/65), grade II (19/65), and grade III (17/65). The tumor size, clinical stage, histological diagnosis, presence/absence of myoepithelial proliferation, and regional lymph node metastases at diagnosis were significantly associated with histological grade. The histological grade, age, clinical stage, tumor subtype group, and lymph node metastases at time of diagnosis were significantly associated with the development of recurrences and/or metastases, cancer-associated death, and survival times (disease-free survival and overall survival) in univariate analyses. A subdivision of clinical stage I (T1N0M0) into stages IA and IB was proposed in terms of prognosis. The clinical stage, histological grade, and spay status were selected as independent prognostic variables (multivariate analyses) with disease-free survival as the dependent variable. When overall survival was evaluated as a dependent variable, clinical stage and histological grade were selected as the independent covariates. This grading system is a useful prognostic tool, facilitates histological interpretation, and offers uniform criteria for veterinary pathologists. Comparative studies on CMCs performed in different countries should take into account possible changes in the prognoses due to different proportions of spayed females among the selected dog population.


Assuntos
Doenças do Cão/patologia , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Animais/patologia , Animais , Estudos de Coortes , Intervalo Livre de Doença , Cães , Feminino , Seguimentos , Estimativa de Kaplan-Meier , Metástase Linfática , Análise Multivariada , Gradação de Tumores/veterinária , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Recidiva
12.
Phys Rev Lett ; 108(11): 115902, 2012 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-22540488

RESUMO

Sykes et al. [Proc. Natl. Acad. Sci. U.S.A. 102, 17907 (2005)] have reported how electrons injected from a scanning tunneling microscope modify the diffusion rates of H buried beneath Pd(111). A key point in that experiment is the symmetry between positive and negative voltages for H extraction, which is difficult to explain in view of the large asymmetry in Pd between the electron and hole densities of states. Combining concepts from the theory of ballistic electron microscopy and electron-phonon scattering we show that H diffusion is driven by the s-band electrons only, which explains the observed symmetry.

13.
Nanotechnology ; 21(40): 405702, 2010 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-20823501

RESUMO

We present a combination of experimental STM images and DFT calculations to understand the atomic scale contrast of features found in high-resolution STM images. Simulating different plausible structural models for the tip, we have been able to reproduce various characteristics previously reported in experimental images on TiO(2)(110)-(1 x 1) under controlled UHV conditions. Our results allow us to determine the influence of different chemical and morphological tip terminations on the atomic-resolution STM images of the TiO(2)(110)-(1 x 1) surface. The commonest images have been properly explained using standard models for a W tip, either clean or with a single O atom located at the apex. Furthermore, a double transfer of oxygen atoms can account for different types of bizarre atomic-resolution features occasionally seen, and not conclusively interpreted before. Importantly, we discuss how typical point-defects are imaged on this surface by different tips, namely bridging O vacancies and adsorbed OH groups.

14.
Langmuir ; 26(6): 4113-8, 2010 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-20092363

RESUMO

We have studied the first stages leading to the formation of self-assembled monolayers of S-cysteine molecules adsorbed on a Au(111) surface. Density functional theory (DFT) calculations for the adsorption of individual cysteine molecules on Au(111) at room temperature show low-energy barriers all over the 2D Au(111) unit cell. As a consequence, cysteine molecules diffuse freely on the Au(111) surface and they can be regarded as a 2D molecular gas. The balance between molecule-molecule and molecule-substrate interactions induces molecular condensation and evaporation from the morphological surface structures (steps, reconstruction edges, etc.) as revealed by scanning tunnelling microscopy (STM) images. These processes lead progressively to the formation of a number of stable arrangements, not previously reported, such as single-molecular rows, trimers, and 2D islands. The condensation of these structures is driven by the aggregation of new molecules, stabilized by the formation of electrostatic interactions between adjacent NH(3)(+) and COO(-) groups, together with adsorption at a slightly more favorable quasi-top site of the herringbone Au reconstruction.


Assuntos
Cisteína/química , Ouro/química , Nanoestruturas , Difusão , Microscopia de Tunelamento
15.
Phys Rev Lett ; 105(21): 216102, 2010 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-21231325

RESUMO

We have studied large areas of (√3×√3)R30° graphene commensurate with a Pt(111) substrate. A combination of experimental techniques with ab initio density functional theory indicates that this structure is related to a reconstruction at the Pt surface, consisting of an ordered vacancy network formed in the outermost Pt layer and a graphene layer covalently bound to the Pt substrate. The formation of this reconstruction is enhanced if low temperatures and polycyclic aromatic hydrocarbons are used as molecular precursors for epitaxial growth of the graphene layers.


Assuntos
Grafite/química , Modelos Químicos , Platina/química , Microscopia de Tunelamento , Teoria Quântica
17.
Vet Rec ; 161(24): 805-9, 2007 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18083978

RESUMO

Forty-six dogs with pituitary-dependent hyperadrenocorticism were treated with mitotane by the non-selective adrenocorticolysis protocol and 40 were treated twice a day with trilostane. The treatment groups were compared by chi-squared tests, and survival data were analysed using Kaplan-Meier survival plots and a Cox proportional hazard method. The non-selective adrenocorticolysis protocol was very effective (89 per cent), its toxicity was moderate (24 per cent) and there were fewer recurrences (29 per cent) than reported with the classical selective adrenocorticolysis protocol (58 per cent). In a multivariate model, age and bodyweight at diagnosis were significantly negatively correlated with survival time. The median survival time of the dogs treated with trilostane twice a day (900 days) was longer (P=0.05) than that of the dogs treated with mitotane (720 days).


Assuntos
Hiperfunção Adrenocortical/veterinária , Antineoplásicos Hormonais/uso terapêutico , Di-Hidrotestosterona/análogos & derivados , Doenças do Cão/tratamento farmacológico , Mitotano/uso terapêutico , Hiperfunção Adrenocortical/tratamento farmacológico , Hiperfunção Adrenocortical/mortalidade , Fatores Etários , Animais , Antineoplásicos Hormonais/efeitos adversos , Peso Corporal/fisiologia , Di-Hidrotestosterona/efeitos adversos , Di-Hidrotestosterona/uso terapêutico , Doenças do Cão/mortalidade , Cães , Feminino , Estimativa de Kaplan-Meier , Masculino , Mitotano/efeitos adversos , Modelos de Riscos Proporcionais , Resultado do Tratamento
18.
Phys Rev Lett ; 96(5): 055502, 2006 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-16486946

RESUMO

Combining STM, LEED, and density functional theory, we determine the atomic surface structure of rutile TiO2 (110)-(1 x 2): nonstoichiometric Ti2O3 stripes along the [001] direction. LEED patterns are sharp and free of streaks, while STM images show monatomic steps, wide terraces, and no cross-links. At room temperature, atoms in the Ti2O3 group have large amplitudes of vibration. The long quasi-1D chains display metallic character, show no interaction between them, and cannot couple to bulk or surface states in the gap region, forming good atomic wires.

19.
Phys Rev Lett ; 92(13): 136104, 2004 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-15089633

RESUMO

Based on the results of density functional theory calculations, a novel mechanism for the diffusion of water dimers on metal surfaces is proposed, which relies on the ability of H bonds to rearrange through quantum tunneling. The mechanism involves quasifree rotation of the dimer and exchange of H-bond donor and acceptor molecules. At appropriate temperatures, water dimers diffuse more rapidly than water monomers, thus providing a physical explanation for the experimentally measured high diffusivity of water dimers on Pd[111] [Science 297, 1850 (2002)]].

20.
Phys Rev Lett ; 90(21): 216102, 2003 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-12786566

RESUMO

Ab initio density functional theory has been used to investigate the adsorption of H2O on several close-packed transition and noble metal surfaces. A remarkably common binding mechanism has been identified. On every surface H2O binds preferentially at an atop adsorption site with the molecular dipole plane nearly parallel to the surface. This binding mode favors interaction of the H2O 1b(1) delocalized molecular orbital with surface wave functions.

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