RESUMEN
OBJECTIVES: To describe the CT characteristics of uterine and vaginal mesenchymal tumours in dogs and to discuss imaging findings of the tumour types encountered. MATERIALS AND METHODS: Retrospective study on female dogs with confirmed histological diagnosis of uterine and vaginal mesenchymal tumours and available CT images. RESULTS: 120 records obtained through a medical record search were manually evaluated for eligibility, and 11 dogs presenting masses associated with the genital tract were identified. Of these 11 dogs, 7 dogs met the inclusion criteria and were included in the study. A clear degree of overlap was present between measurements of maximal diameter of benign and malignant tumours; however, malignant neoplasms tended to occupy a larger portion of the pelvic canal. Objective measurements of length suggest that malignant tumours were longer than benign forms. Bone involvement was only observed with malignancy. CLINICAL SIGNIFICANCE: Although CT is likely to play a limited role in the advanced workup of uterine and vaginal mesenchymal neoplasms, CT may represent a more accessible diagnostic tool than MRI and results of this study may help imagers familiarise themselves with their appearances.
Asunto(s)
Enfermedades de los Perros , Neoplasias , Neoplasias Vaginales , Animales , Enfermedades de los Perros/diagnóstico por imagen , Perros , Femenino , Imagen por Resonancia Magnética , Neoplasias/veterinaria , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/veterinaria , Neoplasias Vaginales/diagnóstico por imagen , Neoplasias Vaginales/veterinariaRESUMEN
Leptospirosis pulmonary haemorrhage syndrome (LPHS) is a frequent manifestation of Leptospira infection in dogs and is associated with a high morbidity and mortality. Three helical 16-slice thoracic CT scans were performed in 10 dogs naturally infected with Leptospira, within 24 hours of admission, and three and seven days later. Patients were sedated and scanned without breathhold, with a protocol adapted for rapid scanning. One dog died of respiratory failure on the morning following the first scan. On the initial scan, imaging features of LPHS included ground-glass nodules (10/10), peribronchovascular interstitial thickening (10/10), diffuse or patchy ground-glass opacity (9/10), solid nodules (8/10) and consolidation (7/10). Temporary bronchiolar dilation was observed in all dogs in association with peribronchovascular interstitial thickening, which had completely resolved at day 7. Nodules were with few exceptions assigned to the centrilobular region. Regression of lesion severity was observed after each subsequent scan. Consolidation and solid nodules changed over time into lesions of ground-glass attenuation. Pleural effusion (3/10) and mediastinal effusion (2/10) were mild and transient. Lesion severity appeared unassociated with survival to discharge.
Asunto(s)
Enfermedades de los Perros/diagnóstico por imagen , Leptospirosis/veterinaria , Enfermedades Pulmonares/veterinaria , Tomografía Computarizada por Rayos X/veterinaria , Animales , Perros , Femenino , Leptospirosis/diagnóstico por imagen , Enfermedades Pulmonares/diagnóstico por imagen , Masculino , Índice de Severidad de la Enfermedad , Análisis de SupervivenciaRESUMEN
OBJECTIVE: To describe an indirect reduction method for ventral fixation of atlantoaxial instability. STUDY: Retrospective study. ANIMALS: Miniature dogs (n = 5) with atlanto-axial instability. MATERIALS AND METHODS: For surgery, the anaesthetized dogs were positioned in dorsal recumbency. A standard ventral midline cranial cervical approach was used. The median part of the cervical (C) vertebral bodies of C1, C2 and C3 were exposed. After excision of the atlantoaxial joint capsule, a fenestration was performed at the C2-C3 intervertebral disc with a narrow slot in the ventral cranial endplate of C3. A midline incision of the atlanto-occipital membrane at the intercondyloid incisure was made to provide access to the spinal canal. Longitudinal distraction and realignment of C1-C2 were obtained by placing the tips of a Gelpi retractor in the two openings created. Overdistraction allowed removal of articular cartilage between C1-C2. Closing of the C1-C2 articular gap was finally achieved by applying lateral distraction with a second Gelpi retractor placed between the paired longus colli muscles. Fixation could then be performed without further stabilization. RESULTS: No intraoperative complications were observed. Recovery was uneventful. CONCLUSIONS: The described technique offered good surgical visibility and permitted safe reduction of atlantoaxial subluxation. CLINICAL RELEVANCE: By reducing manipulation and instrumentation necessary for reduction of atlantoaxial instability, the described technique may be advantageous in toy-breed dogs.
Asunto(s)
Articulación Atlantoaxoidea/patología , Enfermedades de los Perros/cirugía , Procedimientos Ortopédicos/veterinaria , Animales , Tamaño Corporal , Perros , Femenino , Masculino , Procedimientos Ortopédicos/métodos , Estudios RetrospectivosRESUMEN
Short hydrophobic regions referred to as fusion peptide domains (FPDs) at or near the amino terminus of the membrane-anchoring subunit of viral glycoproteins are believed to insert into the host membrane during the initial stage of enveloped viral entry. Avian sarcoma and leukosis viruses (ASLV) are unusual among retroviruses in that the region in the envelope glycoprotein (EnvA) proposed to be the FPD is internal and contains a centrally located proline residue. To begin analyzing the function of this region of EnvA, 20 substitution mutations were introduced into the putative FPD. The mutant envelope glycoproteins were evaluated for effects on virion incorporation, receptor binding, and infection. Interestingly, most of the single-substitution mutations had little effect on any of these processes. In contrast, a bulky hydrophobic substitution for the central proline reduced viral titers 15-fold without affecting virion incorporation or receptor binding, whereas substitution of glycine for the proline had only a nominal effect on EnvA function. Similar to other viral FPDs, the putative ASLV FPD has been modeled as an amphipathic helix where most of the bulky hydrophobic residues form a patch on one face of the helix. A series of alanine insertion mutations designed to interrupt the hydrophobic patch on the helix had differential effects on infectivity, and the results of that analysis together with the results observed with the substitution mutations suggest no correlation between maintenance of the hydrophobic patch and glycoprotein function.
Asunto(s)
Virus de la Leucosis Aviar , Virus del Sarcoma Aviar , Mutación , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/genética , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Virus de la Leucosis Aviar/química , Virus de la Leucosis Aviar/genética , Virus de la Leucosis Aviar/patogenicidad , Virus del Sarcoma Aviar/química , Virus del Sarcoma Aviar/genética , Virus del Sarcoma Aviar/patogenicidad , Virus del Sarcoma Aviar/fisiología , Línea Celular , Ensayo de Inmunoadsorción Enzimática , Epítopos , Datos de Secuencia Molecular , Mutagénesis Insercional , Mutación Puntual , Receptores Virales/metabolismo , Eliminación de Secuencia , Proteínas del Envoltorio Viral/metabolismo , Virión/metabolismoAsunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Neoplasias de la Mama/patología , Neoplasias de la Coroides/secundario , Paclitaxel/uso terapéutico , Adulto , Neoplasias de la Coroides/diagnóstico por imagen , Neoplasias de la Coroides/tratamiento farmacológico , Diagnóstico Diferencial , Ojo/diagnóstico por imagen , Femenino , Humanos , Ultrasonografía , Trastornos de la Visión/etiologíaRESUMEN
The amino-terminal region of the low-density lipoprotein receptor (LDLR) contains seven imperfect repeats of a cysteine-rich, roughly 40-aa module (LDL-A module) that are critical for apolipoprotein binding. LDL-A modules are found in numerous cell-surface and secreted proteins and are believed to mediate extracellular protein-protein interactions. The cellular receptor for subgroup A Rous sarcoma virus (RSV) contains a single LDL-A module that binds the RSV envelope protein and allows viral infection. To define residues in an LDL-A module responsible for ligand recognition, we used a gain of function assay by using a chimeric protein in which the LDL-A module of Tva was replaced with a highly homologous module from human LDLR (LDL-A4) and determined whether this chimera or mutants produced in it could mediate RSV infection. LDL-A4 does not function as an RSV receptor; however, systematic replacement of the nonconserved residues of the LDL-A4 module in the chimeric protein with the corresponding residues from Tva identified three residues sufficient to alter ligand specificity and convert LDL-A4 to an efficient viral receptor. Mutations of the corresponding residues in the Tva LDL-A module decreased both envelope binding and viral receptor function, confirming the importance of these residues in ligand recognition by this module. Analysis of the hLDL-A5 structure demonstrates that these three residues are clustered at one end of the LDL-A module. These results demonstrate that using a single LDL-A module in a gain of function assay is a useful model to investigate ligand recognition by this module.
Asunto(s)
Lipoproteínas LDL/metabolismo , Receptores de LDL/metabolismo , Receptores Virales/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Secuencia de Bases , Sitios de Unión , Línea Celular , Cartilla de ADN , Células HeLa , Humanos , Ligandos , Datos de Secuencia Molecular , Mutagénesis , Receptores de LDL/química , Receptores de LDL/genética , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Homología de Secuencia de AminoácidoRESUMEN
Tva is the cellular receptor for subgroup A avian leukosis and sarcoma virus (ALSV-A). The viral interaction domain of Tva is determined by a 40-residue, cysteine-rich module closely related to the ligand binding domain of the human low-density lipoprotein receptor (LDLR). In this report, we examined the role of the LDLR-like module of Tva in envelope binding and viral infection by mutational analysis. We found that the entire LDLR module in Tva is essential for efficient binding to the viral envelope protein. However, the 17 N-terminal residues of this module can be deleted without affecting receptor function, suggesting that the major determinants for viral entry are located at the C terminus of the module. The effect on viral infection of many amino acid substitutions and deletions in the LDLR module is context dependent, suggesting that the residues important for viral entry are dispersed throughout the LDLR module. In addition, we found that all 27 mutations at residues D46, E47, and W48 greatly reduced envelope binding. These results are discussed in relation to a recently elucidated structure for an LDLR module.