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Dive into the research topics where F. Esteves is active.

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Featured researches published by F. Esteves.


Veterinary Pathology | 2001

A Case of Angiokeratoma

Helena Vala; F. Esteves

Angiokeratoma is described by various authors as a rare variant of the hemangioma in the dog, characterized by a vascular component, like all types of vascular neoplasms, but also by an epithelial component. A case of angiokeratoma is described in a male 8-year-old dog. The tumor was located in heavily pigmented skin on the anterior surface of the front limb and not in the more usual previously described locations, eyelid and conjunctiva. Microscopic examination revealed a well-circumscribed mass with irregular hyperplasia of the epidermis and dilated vascular spaces filled with blood in the superficial dermis.


Journal of Comparative Pathology | 2012

Melanocytic Tumour in a Black Sheep never exposed to Ultraviolet Radiation

Helena Vala; Helena Pópulo; J. Mesquita; F. Esteves; Carla Santos; Paula Soares; José Manuel Lopes

A slow growing skin tumour was identified on the head of a 6-year-old male Serra da Estrela black sheep. The animal had no previous history of exposure to ultraviolet radiation or illness. The tumour consisted of an irregular mass subdivided into two polypoid regions and there were small alternating pigmented and non-pigmented areas in the surrounding epidermis. Microscopical and immunohistochemical features were consistent with a melanocytic tumour of the melanocytoma type, without signs of vascular or perineural invasion. The tumour cells contained pigment stained by the Masson Fontana reaction, expressed S100 protein and vimentin and displayed a low proliferative rate (Ki67 labelling <1%). No metastases were found at the time of gross necropsy examination. Analyses of the homologous regions of the hot spot mutational exons of BRAF and NRAS (the genes that are most often mutated in human melanocytic tumours) did not reveal alterations, but there were silent polymorphic variations in these genes. No such variation was observed in the GNAQ gene sequence that is mutated in human melanocytomas.


Ecohealth | 2018

Prospective Serosurvey of Coxiella burnetii Antibodies in Selected Sheep of Portugal

R. Cruz; F. Esteves; C. Vasconcelos-Nóbrega; Carla Santos; Ana S. Ferreira; A. C. Mega; Ana Cláudia Coelho; Helena Vala; J. Mesquita

Q fever is a zoonotic disease caused by Coxiella burnetii that is highly prevalent across the world. In this study, a prospective serosurvey was performed to study C. burnetii circulation in a population of sheep in the central region of Portugal. Blood from a representative sample of 168 animals was drawn in both 2015 and 2016, and sera were tested for IgG anti-C. burnetii by EIA. In 2015, 7.7% (13/168) animals tested positive for IgG anti-C. burnetii, while in 2016, 17.3% (29/168) tested positive, showing a statistically significant (P = 0.008) increase in anti-C. burnetii seroprevalence. Results support the notion that Q fever is emerging in central Portugal.


Archive | 2016

Epidemiology and Emergence of Schmallenberg Virus Part 1: Origin, Transmission and Differential Diagnosis

F. Esteves; J. Mesquita; C. Nóbrega; CarlaSantos; António Monteiro; R. Cruz; Helena Vala; Ana CláudiaCoelho

Schmallenberg virus (SBV) is a novel Orthobunyavirus causing mild clinical signs in cows and malformations in aborted and neonatal ruminants in Europe. SBV belongs to the family Bunyaviridae and is transmitted by biting midges. This new virus was identified for the first time in the blood samples of cows in the city of Schmallenberg in North‐ Rhine‐Westphalia in November 2011. Since then the virus spread to several European countries. Here we describe the origin and emergence, as well as the transmission and the differential diagnosis of this virus, now known to be a serious threat to Veterinary Public Health.


Archive | 2016

Epidemiology and Emergence of Schmallenberg Virus Part 2: Pathogenesis and Risk of Viral Spread

F. Esteves; J. Mesquita; C. Nóbrega; CarlaSantos; António Monteiro; R. Cruz; Helena Vala; Ana CláudiaCoelho

Schmallenberg virus (SBV) is a novel Orthobunyavirus causing mild clinical signs in cows and malformations in aborted and neonatal ruminants in Europe. SBV belongs to the family Bunyaviridae and is transmitted by biting midges. This new virus was identified for the first time in blood samples of cows in the city of Schmallenberg in North-Rhine Westphalia in November 2011. Since then, the virus spread to several European countries. Here, we describe the pathogenesis and the risk of viral spread in the Portuguese territory.


Archive | 2013

The Endocrine Glands in the Dog: From the Cell to Hormone

Helena Vala; João Rodrigo Mesquita; F. Esteves; Carla Santos; R. Cruz; C. Mega; C. Nóbrega

The animal body represents one of the more complex and perfect systems of nature. Despite its complexity and its functionality, which is incredibly effective, the control of its basic functions is performed by only two systems: the nervous system and endocrine system. The nervous system is associated with electrical and chemical signals that are transmitted at high speed, resulting in rapid organic activities. The endocrine system acts through the synthesis and release of chemical messengers and is responsible for several functions of the organism, in a slower, but more durable way.


Paratuberculosis | 2007

Paratuberculosis in Sheep from Serra da Estrela Region

Helena Vala; C. Santos; F. Esteves; T. Albuquerque; A. Afonso; A. Botelho; C. Seixas; M Amaral; A. Amado


Transboundary and Emerging Diseases | 2018

Outbreaks of abortions by Coxiella burnetii in small ruminant flocks and a longitudinal serological approach on archived bulk tank milk suggest Q fever emergence in Central Portugal

R. Cruz; F. Esteves; C. Vasconcelos-Nóbrega; Carla Santos; Ana S. Ferreira; Cristina Mega; Ana Cláudia Coelho; Helena Vala; J. Mesquita


Transboundary and Emerging Diseases | 2018

Serologic evidence for Schmallenberg virus circulation at high altitude, Central Portugal, 2015-2016

F. Esteves; R. Cruz; C. Vasconcelos-Nóbrega; Carla Santos; Ana S. Ferreira; T. Petrovic; L. Cardoso; Ana Cláudia Coelho; Helena Vala; Maria São José Nascimento; J. Mesquita


Journal of Comparative Pathology | 2018

Hepatic Histopathological Lesions in Acute Controlled Haemorrhage Followed by Volume Replacement With A Crystalloid or Colloid Solution

Helena Vala; R. Pina; R. Cruz; C. Venancio; F. Esteves; A. Silva; J. Mesquita; A. L. Ortiz; D. A. Ferreira

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R. Cruz

Polytechnic Institute of Viseu

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J. Mesquita

Polytechnic Institute of Viseu

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A. C. Mega

Polytechnic Institute of Viseu

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Helena Vala

Polytechnic Institute of Viseu

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C. Santos

Universidade Federal de Lavras

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Carla Santos

Polytechnic Institute of Viseu

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C. Mega

University of Coimbra

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C. Vasconcelos-Nóbrega

Polytechnic Institute of Viseu

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Catarina Coelho

Instituto Politécnico Nacional

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Ana Cláudia Coelho

University of Trás-os-Montes and Alto Douro

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