Cholangiocarcinoma in a Free-Ranging Eurasian Brown Bear (Ursus arctos arctos) from Northern Spain

A hepatic cholangiocarcinoma with metastases in the gallbladder, left elbow joint, adrenal glands, and lungs was observed in a female 21-yr-old free-ranging Eurasian brown bear (Ursus arctos arctos) found in the Principality of Asturias (northern Spain). Gross and histopathologic findings are described.

Characterization of minimal lesions related to the presence of visna/maedi virus in the mammary gland and milk of dairy sheep

Background

In order to characterize the complete range of lesions, especially minimal, affecting mammary gland and viral antigen distribution and target cells using immunohistochemistry in naturally Visna/maedi (VM) 84 infected sheep were studied, forty-four from flocks with clinical cases (A) and 35 randomly sampled from two abattoirs (B) together with five negative controls (C). An immunocytochemistry technique was developed and further milk samples (n = 39) were used to study viral excretion, carrier cells and the role of milk and colostrum in the transmission of the disease.

Results

All sheep from group C and three sheep from group B were negative to VM in tissue sections by histopathology, immunohistochemistry and PCR, and also in serum using ELISA. Several degrees of CD3 + lymphocytic interstitial mastitis were observed in groups A and B: minimal (+) n = 26 sheep; moderate (++), n = 32 and severe (+++), n = 12. No differences in lesion distribution were observed between groups A and B. Viral presence was confirmed by immunohistochemistry using two different antibodies and/or PCR in every tissue with lesions while serology was negative in six sheep with lesions. Two milk samples taken from milk tanks from two flocks from group A and fourteen milk samples from 29 infected sheep from group B were positive to VM (most of them from animals with moderate and severe lesions). Positivity was only found in macrophages, even in focal and minimal lesions, while no positivity was observed in epithelial or any other cells in either tissue and milk samples.

Conclusions

This new observation of the minimal lesions described in this work increased the prevalence of VM lesions in mammary gland up to 90.9% and VM should be considered as a differential diagnosis when minimal interstitial lesions are detected. A high prevalence of VM was observed in intensive milk-producing sheep, ELISA serology did not detect as positivity all infected animals, while histology, IHC or PCR showed higher sensitivity. The cytological technique developed was very useful in milk-cell studies using hematoxylin and eosin and immunocytochemistry. Viral detection in milk samples (16/39) confirms a potential but limited role of milk/colostrum in viral transmission.

Electronic supplementary material

The online version of this article (10.1186/s12917-019-1855-3) contains supplementary material, which is available to authorized users.

Genetic Characterization and Phylogenetic Analysis of Small Ruminant Lentiviruses Detected in Spanish Assaf Sheep with Different Mammary Lesions

Small Ruminant Lentiviruses (SRLVs) are widespread in many countries and cause economically relevant, slow, and persistent diseases in sheep and goats. Monitoring the genetic diversity of SRLVs is useful to improve the diagnostic tools used in the eradication programs. In this study, SRLVs detected in Spanish Assaf sheep with different grades of lymphoproliferative mastitis were sequenced. Genetic characterization showed that most samples belonged to type A and were closer to Spanish SRLV isolates previously classified as A2/A3. Four samples belonged to subtype B2 and showed higher homology with Italian B2 strains than with Spanish B2 isolates. Amino acid sequences of immuno-dominant epitopes in the gag region were very conserved while more alterations were found in the LTR sequences. No significant correlations were found between grades of mastitis and alterations in the sequences although samples with similar histological features were phylogenetically closer to each other. Broader genetic characterization surveys in samples with different grades of SRLV-lesions are required for evaluating potential correlations between SRLV sequences and the severity of diseases.

Inflammatory Lesion Patterns in Target Organs of Visna/Maedi in Sheep and their Significance in the Pathogenesis and Diagnosis of the Infection

Ovine visna/maedi (VM) infection is characterized by the development of chronic inflammatory lesions in different organs, mainly in the lung, mammary gland and central nervous system (CNS), with either histiocytic or lymphocytic pattern predominance being described in the CNS. To help to understand the role of host immune response in the development of these patterns, 50 naturally-infected sheep and eight non-infected sheep from intensive milk-producing flocks were studied. The histological lesion patterns in the three main target organs in each sheep were characterized. Lesion severity was determined, including minimal lesions. A histiocytic pattern was observed in 23 sheep (46%), a lymphocytic inflammatory pattern in 19 sheep (38%) and a mixed inflammatory pattern in eight sheep (16%). Forty animals showed moderate or severe lesions (80%), while 10 had minimal lesions (20%). Moderate or severe lesions affected only one target organ in 20 sheep (50%), two organs in 14 sheep (35%) and all three target organs in six sheep (15%). Infection was confirmed by immunohistochemistry (IHC) using an antibody specific for p28 of VM virus/caprine arthritis and encephalitis virus and by polymerase chain reaction (PCR) in all sheep. Minimal inflammatory lesions associated with positive IHC and PCR were observed. The results suggest that the development of a predominant inflammatory pattern in different organs within the same animal may be related to the host immune response. Minimal and focal lesions, not considered previously, should be taken into account when formulating a differential diagnosis in affected sheep.

Lambs are Susceptible to Experimental Challenge with Spanish Goat Encephalitis Virus

Spanish goat encephalitis virus (SGEV) is a member of the genus Flavivirus, family Flaviviridae, and causes encephalomyelitis in goats. The aim of this study was to determine whether sheep are susceptible to experimental challenge with SGEV by two different routes. The results show that SGEV can infect sheep by both the subcutaneous and intravenous routes, resulting in neurological clinical disease with extensive and severe histological lesions in the central nervous system. Lambs challenged subcutaneously developed more severe lesions on the ipsilateral side of the brain, but the lesion morphology was similar irrespective of the route of challenge. The clinical presentation, pathogenesis, lesion morphology and distribution shows that SGEV is very similar to louping ill virus (LIV) and therefore any disease control plan must take into account any host species and SGEV vectors as potential reservoirs. Furthermore, discriminatory diagnostics need to be applied to any sheep or goat suspected of disease due to any flavivirus in areas where SGEV and LIV co-exist.

Effect of an intervention program on the reading comprehension processes and strategies in 5th and 6th grade students

BACKGROUND

Various investigations have revealed that the promotion of cognitive and metacognitive strategies can improve reading comprehension and that when readers receive this type of instruction, they can use monitoring processes and regulation strategies adequately. The goal of this work is to analyze the effects of strategic and metacognitive instruction on reading comprehension processes and strategies, using the "Aprender a Comprender" [Learning to Understand] program.

METHOD

Instruction was carried out in the classroom by two teachers during six months. Ninety-four students participated, 49 from 5th grade and 45 from 6th grade. A pretest-intervention-posttest-follow-up design was used with a comparison group by grade.

RESULTS

The analysis of variance shows an impact of the intervention and its differential maintenance in each grade. The 5th-grade intervention group scored higher than the comparison group in the reading comprehension test, both at posttest and at follow-up. The 6th-grade intervention group scored higher than the comparison group in the Planning scale, both at posttest and at follow-up.

CONCLUSIONS

Textual strategy instruction favors reading comprehension and the progressive development of planning, which is necessary for supervision and regulation, and its effects are maintained over time.

Assessing reading comprehension with narrative and expository texts: Dimensionality and relationship with fluency, vocabulary and memory

Reading comprehension assessment should rely on valid instruments that enable adequate conclusions to be taken regarding students' reading comprehension performance. In this article, two studies were conducted to collect validity evidence for the vertically scaled forms of two Tests of Reading Comprehension for Portuguese elementary school students in the second to fourth grades, one with narrative texts (TRC-n) and another with expository ones (TRC-e). Two samples of 950 and 990 students participated in Study 1, the study of the dimensionality of the TRC-n and TRC-e forms, respectively. Confirmatory factor analyses provided evidence of an acceptable fit for the one-factor solution for all test forms. Study 2 included 218 students to collect criterion-related validity. The scores obtained in each of the test forms were significantly correlated with the ones obtained in other reading comprehension measures and with the results obtained in oral reading fluency, vocabulary and working memory tests. Evidence suggests that the test forms are valid measures of reading comprehension.

Perfiles motivacionales, implicación y ansiedad ante los deberes escolares y rendimiento académico en estudiantes de Educación Secundaria Obligatoria

El propósito de este trabajo es comprobar si existen combinaciones de metas académicas que den lugar a diferentes grupos de perfiles motivacionales y analizar si existen diferencias significativas entre estos grupos en su implicación en los deberes escolares, en la ansiedad ante los deberes y en el rendimiento académico. La muestra está integrada por 714 estudiantes de Educación Secundaria Obligatoria (43.4% chicos y 56.6% chicas). Los resultados permiten identificar cuatro grupos de perfiles motivacionales: un primer grupo formado por estudiantes con múltiples metas (Grupo de Múltiples Metas), un segundo grupo integrado por estudiantes desmotivados (Grupo Desmotivado), un tercer grupo formado por estudiantes con predominio de metas de aprendizaje (Grupo de Metas de Aprendizaje) y un cuarto grupo en el que estarían aquellos estudiantes con un alto miedo al fracaso (Grupo de Evitación del Fracaso). Con respecto a las diferencias entre los grupos, los resultados indicaron que el perfil de estudiantes orientados hacia metas de aprendizaje es el que presenta unas puntuaciones más altas en todas las variables estudiadas, excepto en la ansiedad ante los deberes. Este grupo realiza más cantidad de deberes, pasa más tiempo dedicado a ellos, gestiona mejor ese tiempo y, además, obtiene un rendimiento académico más alto. Unos resultados muy parecidos los obtiene también el grupo de estudiantes con múltiples metas, pero quizás la implicación en los deberes escolares sea más “tranquila” en el primer grupo, debido fundamentalmente a los bajos niveles de ansiedad que los deberes escolares le generan. El grupo de múltiples metas, que combina metas de distinta naturaleza y que pueden entrar en conflicto, probablemente sostengan un alto nivel de exigencia que lo lleva a tener también a unos mayores niveles de ansiedad ante los deberes escolares. De todos modos, los niveles más altos de ansiedad ante los deberes escolares son los del grupo de evitación del fracaso. El temor al fracaso, que caracteriza a los estudiantes con este perfil motivacional, los lleva a una constante preocupación por evitar parecer incompetentes ante los demás. Por el contrario, el grupo de estudiantes desmotivados presenta, junto con una baja implicación en los deberes y un bajo rendimiento académico, los niveles de ansiedad antes los deberes escolares más bajos.