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2.
Front Vet Sci ; 11: 1362693, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38511192

RESUMO

Introduction: Mixed tumours in the canine mammary gland are the most common histological type in routine diagnosis. In general, these neoplasms have a favourable prognosis that does not evolve into metastatic disease. However, some cases develop into lymph node metastases and are associated with worse patient survival rates. Methods: Here is a retrospective study of 46 samples of primary mixed tumours of the canine mammary gland: 15 cases of benign mixed tumours (BMT), 16 cases of carcinoma in mixed tumours without lymph node metastasis (CMT), and 15 cases of carcinomas in mixed tumours with lymph node metastasis (CMTM). In addition, we selected 23 cases of normal mammary glands (NMT) for comparison. The samples were collected from biopsies performed during nodulectomy, simple mastectomy, regional mastectomy, or unilateral/bilateral radical mastectomy. We used multiphoton microscopy, second harmonic generation, and two-photon excited fluorescence, to evaluate the characteristics of collagen fibres and cellular components in biopsies stained with haematoxylin and eosin. We performed Ki67, ER, PR, and HER-2 immunostaining to define the immunophenotype and COX-2. We showed that carcinomas that evolved into metastatic disease (CMTM) present shorter and wavier collagen fibres as compared to CMT. Results and discussion: When compared to NMT and BMT the carcinomas present a smaller area of fibre coverage, a larger area of cellular coverage, and a larger number of individual fibres. Furthermore, we observed a correlation between the strong expression of COX-2 and a high rate of cell proliferation in carcinomas with a smaller area covered by cell fibres and a larger number of individual fibres. These findings highlight the fundamental role of collagen during tumour progression, especially in invasion and metastatic dissemination.

3.
J Biophotonics ; 16(6): e202200382, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36806587

RESUMO

Prostate carcinoma, a slow-growing and often indolent tumour, is the second most commonly diagnosed cancer among men worldwide. The prognosis is mainly based on the Gleason system through prostate biopsy analysis. However, new treatment and monitoring strategies depend on a more precise diagnosis. Here, we present results by multiphoton imaging for prostate tumour samples from 120 patients that allow to obtain quantitative parameters leading to specific tumour aggressiveness signatures. An automated image analysis was developed to recognise and quantify stromal fibre and neoplastic cell regions in each image. The set of metrics was able to distinguish between non-neoplastic tissue and carcinoma areas by linear discriminant analysis and random forest with accuracy of 89% ± 3%, but between Gleason groups of only 46% ± 6%. The reactive stroma analysis improved the accuracy to 65% ± 5%, clearly demonstrating that stromal parameters should be considered as additional criteria for a more accurate diagnosis.


Assuntos
Carcinoma , Neoplasias da Próstata , Masculino , Humanos , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Aprendizado de Máquina , Biópsia , Carcinoma/patologia
4.
Front Nutr ; 10: 1297926, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38249608

RESUMO

Overcoming the challenge of creating thick, tissue-resembling muscle constructs is paramount in the field of cultivated meat production. This study investigates the remarkable potential of random cellulose acetate nanofibers (CAN) as a transformative scaffold for muscle tissue engineering (MTE), specifically in the context of cultivated meat applications. Through a comparative analysis between random and aligned CAN, utilizing C2C12 and H9c2 myoblasts, we unveil the unparalleled capabilities of random CAN in facilitating muscle differentiation, independent of differentiation media, by exploiting the YAP/TAZ-related mechanotransduction pathway. In addition, we have successfully developed a novel process for stacking cell-loaded CAN sheets, enabling the production of a three-dimensional meat product. C2C12 and H9c2 loaded CAN sheets were stacked (up to four layers) to form a ~300-400 µm thick tissue 2 cm in length, organized in a mesh of uniaxial aligned cells. To further demonstrate the effectiveness of this methodology for cultivated meat purposes, we have generated thick and viable constructs using chicken muscle satellite cells (cSCs) and random CAN. This groundbreaking discovery offers a cost-effective and biomimetic solution for cultivating and differentiating muscle cells, forging a crucial link between tissue engineering and the pursuit of sustainable and affordable cultivated meat production.

5.
Phys Chem Chem Phys ; 24(36): 21750-21758, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36094295

RESUMO

Thionated nucleobases are obtained by replacing oxygen with sulphur atoms in the canonical nucleobases. They absorb light efficiently in the near-ultraviolet, populating singlet states which undergo intersystem crossing to the triplet manifold on an ultrashort time scale with a high quantum yield. Nonetheless there are still important open questions about the primary mechanisms responsible for this ultrafast transition. Here we track both the electronic and the vibrational ultrafast excited-state dynamics towards the triplet state for solvated 4-thiothymidine (4TT) and 4-thiouracil (4TU) with sub-30 fs broadband transient absorption spectroscopy in the ultraviolet. A global and target analysis allows us to simultaneously resolve the contributions of the different electronically and vibrationally excited states to the whole data set. Our experimental results, combined with state-of-the-art quantum mechanics/molecular mechanics simulations and Damped Oscillation Associated Spectra (DOAS) and target analysis, support that the relaxation to the triplet state is mediated by conical intersections promoted by vibrational coherences through the population of an intermediate singlet state. In addition, the analysis of the coherent vibrational dynamics reveals that, despite sharing the same relaxation mechanism and similar chemical structures, 4TT and 4TU exhibit rather different geometrical deformations, characterized by the conservation of planarity in 4TU and its partial rupture in 4TT.


Assuntos
Simulação de Dinâmica Molecular , Vibração , Oxigênio , Enxofre
6.
Molecules ; 27(4)2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-35208987

RESUMO

Understanding the primary steps following UV photoexcitation in sulphur-substituted DNA bases (thiobases) is fundamental for developing new phototherapeutic drugs. However, the investigation of the excited-state dynamics in sub-100 fs time scales has been elusive until now due to technical challenges. Here, we track the ultrafast decay mechanisms that lead to the electron trapping in the triplet manifold for 6-thioguanine in an aqueous solution, using broadband transient absorption spectroscopy with a sub-20 fs temporal resolution. We obtain experimental evidence of the fast internal conversion from the S2(ππ*) to the S1(nπ*) states, which takes place in about 80 fs and demonstrates that the S1(nπ*) state acts as a doorway to the triplet population in 522 fs. Our results are supported by MS-CASPT2 calculations, predicting a planar S2(ππ*) pseudo-minimum in agreement with the stimulated emission signal observed in the experiment.


Assuntos
Tioguanina/química , Espectrofotometria Ultravioleta
7.
Chemistry ; 26(1): 336-343, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31750960

RESUMO

Photoinduced processes in thiouracil derivatives have lately attracted considerable attention due to their suitability for innovative biological and pharmacological applications. Here, sub-20 fs broadband transient absorption spectroscopy in the near-UV are combined with CASPT2/MM decay path calculations to unravel the excited-state decay channels of water solvated 2-thio and 2,4-dithiouracil. These molecules feature linear absorption spectra with overlapping ππ* bands, leading to parallel decay routes which we systematically track for the first time. The results reveal that different processes lead to the triplet states population, both directly from the ππ* absorbing state and via the intermediate nπ* dark state. Moreover, the 2,4-dithiouracil decay pathways is shown to be strongly correlated either to those of 2- or 4-thiouracil, depending on the sulfur atom on which the electronic transition localizes.

8.
PLoS One ; 11(12): e0165371, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27992423

RESUMO

BACKGROUND: The angiotensin-I converting enzyme (ACE) plays a central role in the renin-angiotensin system, acting by converting the hormone angiotensin-I to the active peptide angiotensin-II (Ang-II). More recently, ACE was shown to act as a receptor for Ang-II, and its expression level was demonstrated to be higher in melanoma cells compared to their normal counterparts. However, the function that ACE plays as an Ang-II receptor in melanoma cells has not been defined yet. AIM: Therefore, our aim was to examine the role of ACE in tumor cell proliferation and migration. RESULTS: We found that upon binding to ACE, Ang-II internalizes with a faster onset compared to the binding of Ang-II to its classical AT1 receptor. We also found that the complex Ang-II/ACE translocates to the nucleus, through a clathrin-mediated process, triggering a transient nuclear Ca2+ signal. In silico studies revealed a possible interaction site between ACE and phospholipase C (PLC), and experimental results in CHO cells, demonstrated that the ß3 isoform of PLC is the one involved in the Ca2+ signals induced by Ang-II/ACE interaction. Further studies in melanoma cells (TM-5) showed that Ang-II induced cell proliferation through ACE activation, an event that could be inhibited either by ACE inhibitor (Lisinopril) or by the silencing of ACE. In addition, we found that stimulation of ACE by Ang-II caused the melanoma cells to migrate, at least in part due to decreased vinculin expression, a focal adhesion structural protein. CONCLUSION: ACE activation regulates melanoma cell proliferation and migration.


Assuntos
Angiotensina II/metabolismo , Núcleo Celular/metabolismo , Melanoma/enzimologia , Peptidil Dipeptidase A/metabolismo , Fosfolipase C beta/metabolismo , Vinculina/metabolismo , Animais , Células CHO , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Simulação por Computador , Cricetulus , Humanos , Lisinopril/farmacologia , Melanoma/genética , Melanoma/metabolismo , Peptidil Dipeptidase A/genética , Transporte Proteico
9.
PLoS Negl Trop Dis ; 6(5): e1663, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22666512

RESUMO

There are few animal models of dengue infection, especially in immunocompetent mice. Here, we describe alterations found in adult immunocompetent mice inoculated with an adapted Dengue virus (DENV-3) strain. Infection of mice with the adapted DENV-3 caused inoculum-dependent lethality that was preceded by several hematological and biochemical changes and increased virus dissemination, features consistent with severe disease manifestation in humans. IFN-γ expression increased after DENV-3 infection of WT mice and this was preceded by increase in expression of IL-12 and IL-18. In DENV-3-inoculated IFN-γ(-/-) mice, there was enhanced lethality, which was preceded by severe disease manifestation and virus replication. Lack of IFN-γ production was associated with diminished NO-synthase 2 (NOS2) expression and higher susceptibility of NOS2(-/-) mice to DENV-3 infection. Therefore, mechanisms of protection to DENV-3 infection rely on IFN-γ-NOS2-NO-dependent control of viral replication and of disease severity, a pathway showed to be relevant for resistance to DENV infection in other experimental and clinical settings. Thus, the model of DENV-3 infection in immunocompetent mice described here represents a significant advance in animal models of severe dengue disease and may provide an important tool to the elucidation of immunopathogenesis of disease and of protective mechanisms associated with infection.


Assuntos
Vírus da Dengue/imunologia , Vírus da Dengue/patogenicidade , Dengue/imunologia , Dengue/patologia , Modelos Animais de Doenças , Interferon gama/imunologia , Adaptação Biológica , Animais , Citocinas/metabolismo , Dengue/mortalidade , Dengue/virologia , Interferon gama/deficiência , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico Sintase Tipo II/deficiência , Óxido Nítrico Sintase Tipo II/imunologia , Análise de Sobrevida
10.
Hepatology ; 56(5): 1971-82, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22532075

RESUMO

UNLABELLED: Acetaminophen (APAP) is a safe analgesic and antipyretic drug. However, APAP overdose leads to massive hepatocyte death. Cell death during APAP toxicity occurs by oncotic necrosis, in which the release of intracellular contents can elicit a reactive inflammatory response. We have previously demonstrated that an intravascular gradient of chemokines and mitochondria-derived formyl peptides collaborate to guide neutrophils to sites of liver necrosis by CXC chemokine receptor 2 (CXCR2) and formyl peptide receptor 1 (FPR1), respectively. Here, we investigated the role of CXCR2 chemokines and mitochondrial products during APAP-induced liver injury and in liver neutrophil influx and hepatotoxicity. During APAP overdose, neutrophils accumulated into the liver, and blockage of neutrophil infiltration by anti-granulocyte receptor 1 depletion or combined CXCR2-FPR1 antagonism significantly prevented hepatotoxicity. In agreement with our in vivo data, isolated human neutrophils were cytotoxic to HepG2 cells when cocultured, and the mechanism of neutrophil killing was dependent on direct contact with HepG2 cells and the CXCR2-FPR1-signaling pathway. Also, in mice and humans, serum levels of both mitochondrial DNA (mitDNA) and CXCR2 chemokines were higher during acute liver injury, suggesting that necrosis products may reach remote organs through the circulation, leading to a systemic inflammatory response. Accordingly, APAP-treated mice exhibited marked systemic inflammation and lung injury, which was prevented by CXCR2-FPR1 blockage and Toll-like receptor 9 (TLR9) absence (TLR9(-/-) mice). CONCLUSION: Chemokines and mitochondrial products (e.g., formyl peptides and mitDNA) collaborate in neutrophil-mediated injury and systemic inflammation during acute liver failure. Hepatocyte death is amplified by liver neutrophil infiltration, and the release of necrotic products into the circulation may trigger a systemic inflammatory response and remote lung injury.


Assuntos
Reação de Fase Aguda/metabolismo , Quimiocinas/metabolismo , DNA Mitocondrial/sangue , Falência Hepática Aguda/imunologia , Fígado/patologia , Neutrófilos/imunologia , Receptores de Formil Peptídeo/metabolismo , Acetaminofen , Lesão Pulmonar Aguda/sangue , Lesão Pulmonar Aguda/imunologia , Reação de Fase Aguda/imunologia , Adolescente , Adulto , Análise de Variância , Animais , Movimento Celular , Quimiocinas/sangue , Quimiocinas/imunologia , Criança , Técnicas de Cocultura , Feminino , Células Hep G2 , Humanos , Interleucina-8/sangue , Fígado/metabolismo , Falência Hepática Aguda/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Proteínas Mitocondriais/imunologia , Proteínas Mitocondriais/metabolismo , Necrose/imunologia , Receptores de Formil Peptídeo/imunologia , Receptores de Interleucina-8B/sangue , Receptores de Interleucina-8B/imunologia , Receptores de Interleucina-8B/metabolismo , Transdução de Sinais , Síndrome de Resposta Inflamatória Sistêmica/sangue , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/imunologia , Adulto Jovem
11.
Rev. Inst. Adolfo Lutz ; 63(2): 238-242, jul.-dez. 2004. tab, graf
Artigo em Inglês | LILACS, Sec. Est. Saúde SP | ID: lil-404806

RESUMO

Among foodborne diseases, salmonellosis has been considered one of the major public health problems in many countries worldwide. Escherichia coli O157:H7 has been another important foodborne pathogen due to its increasing incidence as a human disease agent and its association with various kinds of foods, especially those from animal origin. Incidence of Salmonella spp. and E. coli O157:H7 in the raw meat (bovine, swine and chicken) marketed in São Paulo - Brazil was determined in 253 samples. Twenty-three samples (9.1%) were positive for Salmonella spp. Among these, 11 different serovars were identified, and S. Enteritidis was found to be the most prevalent. All the tested samples were negative for E. coli O157:H7. Salmonella Enteritidis (the predominant serovar) and E. coli O157:H7 were also tested for their cold-temperature sensitiveness in ground beef kept under refrigeration (4ºC) for 120 days and under freezing (-18ºC) for up to 90 days. E. coli O157:H7 inoculated into ground beef was more sensible to refrigeration and freezing temperatures than S. Enteritidis, but both maintained viability under freezing condition up to 90 days


Assuntos
Alimentos Congelados/toxicidade , Carne , Salmonella
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