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Angiostrongylus vasorum is a metastrongyloid lungworm causing severe cardiovascular disease in domestic and wild animals. During its heteroxenous life cycle, A. vasorum requires obligate gastropod intermediate hosts. Little is known about A. vasorum larval organ tropism and development in gastropod intermediate hosts. Thus, the aim of this study was to analyze in vivo development of A. vasorum larval stages in experimentally infected African giant snails (Lissachatina fulica). Adult L. fulica (n = 26) were orally infected with A. vasorum-L1 and thereafter continuously euthanized. Gastropod organs were artificially digested and microscopically analyzed for the presence of A. vasorum larvae. Moreover, paraffin-fixed organs were investigated histologically for snail-borne innate immune response. In the current study, the success of L. fulica oral infection was demonstrated, thereby reaching larval recovery rates of up to 49.7%. During snail infection, an organ tropism of A. vasorum larvae was detected for the lungs and the foot muscular tissue. Overall, A. vasorum-driven gastropod innate immune reactions against larvae varied greatly. In some specimens, larvae were found effectively ensnared by recruited hemocytes, resulting in granuloma formation, whilst in others, hemocyte-mediated reactions were barely observed. Nevertheless, these evidences demand more studies on hemocyte-derived effector mechanisms against A. vasorum. [ABSTRACT FROM AUTHOR]

Current diagnostic methods for Johne's disease in cattle allow reliable detection of infections with Mycobacterium avium ssp. paratuberculosis (MAP) not before animals are 2 years of age. Applying a flow cytometry-based approach (FCA) to quantify a MAP-specific interferon-gamma (IFN-γ) response in T cell subsets, the present study sought to monitor the kinetics of the cell-mediated immune response in experimentally infected calves. Six MAP-negative calves and six calves, orally inoculated with MAP at 10 days of age, were sampled every 4 weeks for 52 weeks post-inoculation (wpi). Peripheral blood mononuclear cells (PBMC) were stimulated with either purified protein derivatives (PPD) or whole cell sonicates derived from MAP (WCSj), M. avium ssp. avium or M. phlei for 6 days followed by labeling of intracellular IFN-γ in CD4+ and CD8+ T cells. No antigen-specific IFN-γ production was detectable in CD8+ cells throughout and the responses of CD4+ cells of MAP-infected and control calves were similar up to 12 wpi. However, the mean fluorescence intensity (MFI) for the detection of IFN-γ in CD4+ cells after WCSj antigen stimulation allowed for a differentiation of animal groups from 16 wpi onwards. This approach had a superior sensitivity (87.8%) and specificity (86.8%) to detect infected animals from 16 wpi onwards, i.e., in an early infection stage, as compared to the IFN-γ release assay (IGRA). Quantification of specific IFN-γ production at the level of individual CD4+ cells may serve, therefore, as a valuable tool to identify MAP-infected juvenile cattle. [ABSTRACT FROM AUTHOR]

Abstract Background In a cat that had ostensibly recovered from feline leukemia virus (FeLV) infection, we observed the reappearance of the virus and the development of fatal lymphoma 8.5 years after the initial experimental exposure to FeLV-A/Glasgow-1. The goals of the present study were to investigate this FeLV reoccurrence and molecularly characterize the progeny viruses. Results The FeLV reoccurrence was detected by the presence of FeLV antigen and RNA in the blood and saliva. The cat was feline immunodeficiency virus positive and showed CD4+ T-cell depletion, severe leukopenia, anemia and a multicentric monoclonal B-cell lymphoma. FeLV-A, but not -B or -C, was detectable. Sequencing of the envelope gene revealed three FeLV variants that were highly divergent from the virus that was originally inoculated (89-91% identity to FeLV-A/Glasgow-1). In the long terminal repeat 31 point mutations, some previously described in cats with lymphomas, were detected. The FeLV variant tissue provirus and viral RNA loads were significantly higher than the FeLV-A/Glasgow-1 loads. Moreover, the variant loads were significantly higher in lymphoma positive compared to lymphoma negative tissues. An increase in the variant provirus blood load was observed at the time of FeLV reoccurrence. Conclusions Our results demonstrate that ostensibly recovered FeLV provirus-positive cats may act as a source of infection following FeLV reactivation. The virus variants that had largely replaced the inoculation strain had unusually heavily mutated envelopes. The mutations may have led to increased viral fitness and/or changed the mutagenic characteristics of the virus.

This case report describes the rare phenomenon of emperipolesis-like invasion of lymphatic blasts into the hepatocytes of a 15-year-old European Shorthair cat. The cat presented with nonspecific clinical signs (inappetence and weight loss). Cytologic examination of an ultrasound-guided fine-needle aspirate of the liver showed a subset of hepatocytes with emperipolesis-like invasion by lymphatic blasts. Few extracellularly located lymphatic blasts exhibited erythrophagia. Following the cytological diagnosis of large cell lymphoma and 2 weeks of monotherapy with prednisolone, the patient was euthanized due to his poor general condition. A post-mortem sample was obtained from the liver to confirm the suspected cytological diagnosis of hepatocytotropic lymphoma. Histopathology subsequently confirmed the cytologic findings. Immunohistochemically, the lymphatic blasts were positive for CD3 leading to a diagnosis of hepatocytotropic T-cell-lymphoma, which has rarely been described so far., Competing Interests: Die Autoren bestätigen, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

A 10-year-old female mixed breed dog was presented for thyroid scintigraphy due to a cervical mass. Apart from 99m-Technetium-pertechnetate (Tc-pertechnetate) scintigraphy, a second scintigraphy using 99m-Technetium sestamibi (Tc-MIBI) was performed because of additional hypothyroidism suspective for a "cold" nodule and as screening for metastases.Twenty minutes following intravenous injection of 38 MBq Tc-pertechnetate, a "hot" cervical as well as a "hot" intrathoracal nodule were seen with an uptake of 8.40 and 0.25 %, respectively. The second scintigraphy was performed 20 minutes after intravenous injection of 364 MBq Tc-MIBI and 70 minutes following the first. After subtraction of pertechnetate activity and decay correction, both nodules showed an uptake of 0.99 and 0.03 %. Additionally, both thyroid lobes were visible in the thyroid loge with a weak MIBI-uptake. For both lesions, the ratio Tc-uptake/Tc-MIBI-uptake was 8.48 and 8.33, respectively.Following the extirpation of the cervical mass, histopathology revealed atrophied healthy thyroid tissue almost completely displaced by a well-differentiated follicular thyroid carcinoma.This case report describes performance, utility and calculative correction of consecutive pertechnetate- and MIBI-scan, that enable a visualization of hypofunctional thyroid tissue.Therefore and because of their similar MIBI metabolic activity, both nodules were considered to be dystopic tissue/metastases so that this dog had to be classified as prognostically less favorable WHO stabe IV. Different from human patients, both scintigraphies should be performed shortly after another in dogs in order to avoid the necessity of a second anesthetic procedure. A reliable qualitative/visual evaluation of the MIBI-scan is therefore not possible, so that a quantitative assessment using the uptake after calculative correction of the pertechnetate activity is recommended., Competing Interests: Die Autoren bestätigen, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

A 4-day-old female Holstein Friesian calf was presented for evaluation of cyanosis and dyspnea. On auscultation, severe bronchovesicular sounds and a systolic heart murmur of grade IV/VI above the tricuspid valve were found. On echocardiography, a marked dextroposition of the aorta (> 50% originating from the right ventricle), leading to both great arteries arising from the right ventricle - a so-called double-outlet right ventricle - was detected. Two ventricular septal defects were present, one in the perimembranous, subpulmonary region, the other non-committed in the muscular region. The subpulmonary ventricular septal defect was responsible for the shunting of unoxygenated blood into the aorta. Additionally, an aneurysma-like atrial septal defect (type secundum) and a large patent ductus arteriosus were visualized. The main pulmonary artery was severely enlarged without the presence of a stenotic defect. The findings could be verified by angiography. Additionally, a diffuse hypoplastic ascending aorta was visualized. Necropsy confirmed the echocardiographic and angiographic findings.