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1.
Reprod Domest Anim ; 51(1): 33-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26638806

RESUMEN

Human epidermal growth factor receptor type 2 (c-erbB-2), an oncoprotein with potential prognostic marker and therapeutic use, is overexpressed in several human and animal tumours. But information regarding this molecule in feline tumours is scarce. This study aimed to assess the changes in the immunohistochemical expression of c-erbB-2 in feline endometrial adenocarcinomas (FEA) compared to normal endometrium. An immunohistochemistry assay using a specific antibody against c-erbB-2 was performed in FEA samples (n = 34) and in normal endometrium in the follicular (FS; n = 12) and luteal (LS; n = 11) stages. In FEA, the c-erbB-2 immunoexpression was assessed in neoplastic epithelial cells whilst in normal endometria it was individually evaluated in the surface and the superficial and deep glandular epithelia (SE, SGE and DGE, respectively). In FS and in LS, all the epithelia were positive for c-erbB-2; positivity was higher in the SE and the SGE than in DGE. Twenty of the 34 FEA samples (58.8%) were positive for c-erbB-2 immunolabelling. Nevertheless, its expression was higher in all the epithelia in the FS compared to FEA (p ≤ 0.0001) or the LS (p = 0.016). The results presented herein suggest that c-erbB-2 molecule is differently expressed in the feline endometrium through the oestrous cycle and though it may also be involved in feline endometrial carcinogenesis, a question remains unanswered on the importance of additional pathways of epithelial proliferation in the neoplastic changes in feline endometrium.


Asunto(s)
Adenocarcinoma/veterinaria , Enfermedades de los Gatos , Neoplasias Endometriales/veterinaria , Receptor ErbB-2/análisis , Adenocarcinoma/química , Adenocarcinoma/patología , Animales , Gatos , Neoplasias Endometriales/química , Neoplasias Endometriales/patología , Endometrio/química , Femenino , Fase Folicular , Inmunohistoquímica/veterinaria , Fase Luteínica
2.
Nano Lett ; 15(7): 4622-7, 2015 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-26047255

RESUMEN

We report the dispersive readout of the spin state of a double quantum dot formed at the corner states of a silicon nanowire field-effect transistor. Two face-to-face top-gate electrodes allow us to independently tune the charge occupation of the quantum dot system down to the few-electron limit. We measure the charge stability of the double quantum dot in DC transport as well as dispersively via in situ gate-based radio frequency reflectometry, where one top-gate electrode is connected to a resonator. The latter removes the need for external charge sensors in quantum computing architectures and provides a compact way to readout the dispersive shift caused by changes in the quantum capacitance during inter-dot charge transitions. Here, we observe Pauli spin-blockade in the high-frequency response of the circuit at finite magnetic fields between singlet and triplet states. The blockade is lifted at higher magnetic fields when intra-dot triplet states become the ground state configuration. A line shape analysis of the dispersive phase shift reveals furthermore an intra-dot valley-orbit splitting Δvo of 145 µeV. Our results open up the possibility to operate compact complementary metal-oxide semiconductor (CMOS) technology as a singlet-triplet qubit and make split-gate silicon nanowire architectures an ideal candidate for the study of spin dynamics.

3.
J Phys Condens Matter ; 27(15): 154208, 2015 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-25783857

RESUMEN

We provide here a roadmap for modeling silicon nano-devices with one or two group V donors (D). We discuss systems containing one or two electrons, that is, D(0), D(-), D(+)(2) and D(0)(2) centers. The impact of different levels of approximation is discussed. The most accurate instances--for which we provide quantitative results--are within multivalley effective mass including the central cell correction and a configuration interaction account of the electron-electron correlations. We also derive insightful, yet less accurate, analytical approximations and discuss their validity and limitations--in particular, for a donor pair, we discuss the single orbital LCAO method, the Hückel approximation and the Hubbard model. Finally, we connect these results with recent experiments on devices with few dopants.

4.
Reprod Domest Anim ; 50(2): 333-340, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25683901

RESUMEN

Cyclooxygenase-2 (COX-2) is overexpressed in several human and animal neoplasms, including the human endometrial carcinoma. It has been suggested as a prognostic marker and a potential therapeutic target. This study aimed to (i) clarify histological aspects of feline endometrial adenocarcinomas (FEA) of the papillary serous type and (ii) characterize COX-2 immunohistochemical expression in normal, hyperplastic and neoplastic endometrium in this species. Archived paraffin-embedded tissue samples of 33 FEA, eight cystic endometrial hyperplasias (CEHs) and 21 samples of normal, healthy endometrium in the follicular (FS; n = 10) and luteal (LS; n = 11) stages were evaluated. Histological evaluation of haematoxylin and eosin-stained sections of the FEA revealed a papillary proliferation of neoplastic cells of serous type, accompanied by clear and multinucleated cells. Other architectural arrangements mainly included solid and tubular growth. Randomly distributed areas of necrosis within the tumours were commonly observed. Invasion of the myometrium, of the serosa and of the vascular and/or lymphatic vessels was not constant features. The mean number of mitoses was higher in FEA compared to non-neoplastic endometrium. COX-2 scores were lower in FEA (p = 0.003) and CEH (p = 0.05) when compared to normal epithelium (NE). The loss of the membrane apical reinforcement in epithelial cells was observed in FEA samples, which was accompanied by the dislocation of COX-2 labelling into the cytoplasm and the perinuclear area; in contrast, in epithelial cells in the healthy and hyperplastic endometria, the immunoreaction showed the characteristic pattern of apical membrane reinforcement, suggestive of the membrane polarization. COX-2 epithelial scores were higher in the FS than in the LS. No differences were found in stromal COX-2 expression between normal, CEH and FEA groups, but it was higher in the LS than in the FS. In summary, loss of COX-2 compartmentalization in neoplastic epithelial cells might be one of the molecular events underlying endometrial carcinogenesis.


Asunto(s)
Adenocarcinoma/veterinaria , Enfermedades de los Gatos/metabolismo , Ciclooxigenasa 2/metabolismo , Neoplasias Endometriales/veterinaria , Regulación Enzimológica de la Expresión Génica/fisiología , Regulación Neoplásica de la Expresión Génica/fisiología , Adenocarcinoma/metabolismo , Animales , Enfermedades de los Gatos/genética , Gatos , Ciclooxigenasa 2/genética , Neoplasias Endometriales/metabolismo , Femenino
5.
Reprod Domest Anim ; 48(5): e70-7, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23834511

RESUMEN

Uterine neoplasms of epithelial origin are rare in cats and most often are described in older females. Yet, in less than 2 years, four ovariohysterectomy specimens were submitted from different practices to the Laboratory of Histology and Anatomical Pathology, at UTAD (Vila Real, Portugal), that emitted a diagnosis of feline endometrial adenocarcinoma. Untypically, all the females were aged <1 year old at the surgery. Access to the clinical files was requested to document the clinical features of the four cases, including any complementary data available, to construct the present case reports. The clinical situation developed with discrete signs, but vulvar discharge was present in three cases, ranging from bloody to brownish or colourless, and from purulent to mucous. The females were in dioestrus, although the oestrus remained unperceived in most cases. In this study, the four clinical situations are described and discussed on the basis of available literature, highlighting the aspects that may impair an early diagnosis and that may favour the progression of the disease and also that age should not be an excluding criteria when analysing the differential diagnosis list.


Asunto(s)
Adenocarcinoma/veterinaria , Enfermedades de los Gatos/patología , Neoplasias Endometriales/veterinaria , Adenocarcinoma/patología , Adenocarcinoma/cirugía , Animales , Gatos , Neoplasias Endometriales/patología , Neoplasias Endometriales/cirugía , Femenino
6.
Phys Rev Lett ; 108(12): 126804, 2012 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-22540611

RESUMEN

We devise a platform for noise-resistant quantum computing using the valley degree of freedom of Si quantum dots. The qubit is encoded in two polarized (1,1) spin-triplet states with different valley compositions in a double quantum dot, with a Zeeman field enabling unambiguous initialization. A top gate gives a difference in the valley splitting between the dots, allowing controllable interdot tunneling between opposite valley eigenstates, which enables one-qubit rotations. Two-qubit operations rely on a stripline resonator, and readout on charge sensing. Sensitivity to charge and spin fluctuations is determined by intervalley processes and is greatly reduced as compared to conventional spin and charge qubits. We describe a valley echo for further noise suppression.

7.
Vet Pathol ; 48(2): 427-32, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20861495

RESUMEN

Canine renal cell carcinomas (RCCs) are uncommon aggressive tumors that occur mainly in middle-aged male dogs. Their histologic classification bears no relationship with prognosis, and little information is available concerning their immunohistochemical properties. In this retrospective study, formalin-fixed, paraffin-embedded tissues from 13 canine RCCs were retrieved from the archives, classified histologically, and evaluated immunohistochemically. The dogs were 7 males and 6 females (1 spayed) of 10 different breeds, averaging 8 years in age. The tumors were classified as papillary, tubulopapillary, papillary-cystic, solid, or sarcomatoid. All 13 tumors were immunohistochemically positive for uromodulin, 12 for c-KIT, 11 for vimentin, 9 for wide-spectrum-screening cytokeratins, 7 for cytokeratins AE1/AE3 and carcinoembryonic antigen, 4 for cytokeratins CAM 5.2, and 3 for CD10. All 3 solid RCCs expressed vimentin, c-KIT, and carcinoembryonic antigen and were negative for cytokeratins. All 7 papillary and tubulopapillary tumors expressed vimentin; 6 (86%), cytokeratins; and 6 (86%), c-KIT. Both papillary-cystic RCCs were positive for cytokeratins and c-KIT and negative for vimentin. These results indicate that the different histologic types of RCC have characteristic immunohistochemical profiles and that c-KIT may be involved in the pathogenesis of canine RCC.


Asunto(s)
Carcinoma de Células Renales/veterinaria , Enfermedades de los Perros/patología , Neoplasias Renales/veterinaria , Animales , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Renales/clasificación , Carcinoma de Células Renales/patología , Perros , Femenino , Inmunohistoquímica/veterinaria , Neoplasias Renales/clasificación , Neoplasias Renales/patología , Masculino , Proteínas Proto-Oncogénicas c-kit/metabolismo , Estudios Retrospectivos
8.
Braz J Med Biol Res ; 43(12): 1193-202, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21140097

RESUMEN

The objective of this study was to determine the effect of eight 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1-carboxyamidepyrazoles (TFDPs) on rat body temperature and baker's yeast-induced fever. TFDPs or vehicle (5% Tween 80 in 0.9% NaCl, 5 mL/kg) were injected subcutaneously and rectal temperature was measured as a function of time in 28-day-old male Wistar rats (N = 5-12 per group). Antipyretic activity was determined in feverish animals injected with baker's yeast (Saccharomyces cerevisiae suspension, 0.135 mg/kg, 10 mL/kg, ip). 3-Ethyl- and 3-propyl-TFDP (140 and 200 µmol/kg, respectively, 4 h after yeast injection) attenuated baker's yeast-induced fever by 61 and 82%, respectively. These two effective antipyretics were selected for subsequent analysis of putative mechanisms of action. We then determined the effects on cyclooxygenase-1 and -2 (COX-1 and COX-2) activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) oxidation in vitro, on tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) levels and on leukocyte counts in the washes of peritoneal cavities of rats injected with baker's yeast. While 3-ethyl- and 3-propyl-TFDP did not reduce baker's yeast-induced increases of IL-1ß or TNF-α levels, 3-ethyl-TFDP caused a 42% reduction in peritoneal leukocyte count. 3-Ethyl- and 3-propyl-TFDP did not alter COX-1 or COX-2 activities in vitro, but presented antioxidant activity in the DPPH assay with an IC50 of 39 mM (25-62) and 163 mM (136-196), respectively. The data indicate that mechanisms of action of these two novel antipyretic pyrazole derivatives do not involve the classic inhibition of the COX pathway or pyrogenic cytokine release.


Asunto(s)
Antioxidantes/farmacología , Antipiréticos/farmacología , Estrés Oxidativo/efectos de los fármacos , Pirazoles/farmacología , Animales , Antipiréticos/química , Ciclooxigenasa 1/farmacología , Ciclooxigenasa 2/farmacología , Interleucina-1beta/efectos de los fármacos , Interleucina-1beta/metabolismo , Masculino , Pirazoles/química , Ratas , Ratas Wistar , Factor de Necrosis Tumoral alfa/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo
9.
Braz. j. med. biol. res ; 43(12): 1193-1202, Dec. 2010. ilus
Artículo en Inglés | LILACS | ID: lil-569003

RESUMEN

The objective of this study was to determine the effect of eight 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1-carboxyamidepyrazoles (TFDPs) on rat body temperature and baker’s yeast-induced fever. TFDPs or vehicle (5 percent Tween 80 in 0.9 percent NaCl, 5 mL/kg) were injected subcutaneously and rectal temperature was measured as a function of time in 28-day-old male Wistar rats (N = 5-12 per group). Antipyretic activity was determined in feverish animals injected with baker’s yeast (Saccharomyces cerevisiae suspension, 0.135 mg/kg, 10 mL/kg, ip). 3-Ethyl- and 3-propyl-TFDP (140 and 200 μmol/kg, respectively, 4 h after yeast injection) attenuated baker’s yeast-induced fever by 61 and 82 percent, respectively. These two effective antipyretics were selected for subsequent analysis of putative mechanisms of action. We then determined the effects on cyclooxygenase-1 and -2 (COX-1 and COX-2) activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) oxidation in vitro, on tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels and on leukocyte counts in the washes of peritoneal cavities of rats injected with baker’s yeast. While 3-ethyl- and 3-propyl-TFDP did not reduce baker’s yeast-induced increases of IL-1β or TNF-α levels, 3-ethyl-TFDP caused a 42 percent reduction in peritoneal leukocyte count. 3-Ethyl- and 3-propyl-TFDP did not alter COX-1 or COX-2 activities in vitro, but presented antioxidant activity in the DPPH assay with an IC50 of 39 mM (25-62) and 163 mM (136-196), respectively. The data indicate that mechanisms of action of these two novel antipyretic pyrazole derivatives do not involve the classic inhibition of the COX pathway or pyrogenic cytokine release.


Asunto(s)
Animales , Masculino , Ratas , Antioxidantes/farmacología , Antipiréticos/farmacología , Estrés Oxidativo/efectos de los fármacos , Pirazoles/farmacología , Antipiréticos/química , Ciclooxigenasa 1/farmacología , /farmacología , Interleucina-1beta/efectos de los fármacos , Interleucina-1beta/metabolismo , Pirazoles/química , Ratas Wistar , Factor de Necrosis Tumoral alfa/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismo
10.
Vet J ; 177(1): 136-40, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17804265

RESUMEN

p63, a recently identified homologue of the p53 protein, is expressed consistently in basal cells of several human multilayered epithelia. In this study, expression of p63 was determined in 31 primary cutaneous glandular carcinomas, including sebaceous, perianal (hepatoid) gland, apocrine and ceruminous carcinomas, as well as their adjacent normal skin. Similar to humans, p63 is a reliable marker for basal and myoepithelial cells in canine epidermis, cutaneous appendages and malignant apocrine and ceruminous gland neoplasms. In sebaceous carcinomas, not only basal cells, but also some sebocytes, showed nuclear staining for p63. Most mature epithelial cells in perianal gland carcinomas exhibited strong p63 expression. Based on these findings, basal/myoepithelial cells could be involved in the oncogenesis of these tumours and p63 might be used as a diagnostic marker in these lesions.


Asunto(s)
Enfermedades de los Perros/metabolismo , Epidermis/metabolismo , Neoplasias Glandulares y Epiteliales/veterinaria , Neoplasias Cutáneas/veterinaria , Proteínas Supresoras de Tumor/metabolismo , Animales , Biomarcadores de Tumor/metabolismo , Enfermedades de los Perros/diagnóstico , Perros , Regulación Neoplásica de la Expresión Génica , Genes Supresores de Tumor , Inmunohistoquímica/veterinaria , Neoplasias Glandulares y Epiteliales/diagnóstico , Neoplasias Glandulares y Epiteliales/metabolismo , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/metabolismo , Transactivadores , Factores de Transcripción
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