Echocardiographic and Doppler diagnosis: first case of atrial septal aneurysm in a cat.

A 6-year-old female cat developed pleural and abdominal effusion. Cardiac ultrasound and 2D color tissue Doppler imaging revealed restrictive cardiomyopathy with severe biatrial dilatation and hypertension. This cardiomyopathy was associated with atrial septal aneurysm and a patent foramen ovale. The atrial septal aneurysm involved the entire atrial septum. Necropsy and histological examination confirmed all these findings. ASA is a rare malformation and, as in this cat, it generally occurs concomitantly with congenital or acquired heart disease and may be explained by greater pressure in one atrium, leading to controlateral protrusion of the atrial septum.

Disseminated acute concomitant aspergillosis and mucormycosis in a pony.

A 6-year-old female pony died after 2 days of prostration. Clinical signs included hyperthermia and abnormal pulmonary auscultation sounds. Necropsy revealed diffuse severe necrohaemorrhagic colitis and splenitis, multiple visceral ecchymoses, petechial haemorrhages in the brain and lungs. Microscopical examination showed acute necrohaemorrhagic colitis, encephalitis, pneumonia and splenitis associated with fibrinoid vasculitis, thrombosis and fungal hyphae within and around vessels. Immunohistologically, concomitant aspergillosis (caused by Aspergillus fumigatus) and mucormycosis (causde by Absidia corymbifera) were identified in the colonic and pulmonary lesions, whereas pure mucormycosis was observed in cerebral and splenic lesions. Dual mycotic infections are very rarely described, and the present case emphasizes the need of immunohistochemistry in order to obtain a clear-cut diagnosis of mixed fungal infections.

Sclerosing peritoneal mesothelioma in a dog - a case report.

A case of peritoneal sclerosing mesothelioma in a 3-year-old German shepherd dog is reported. The dog presented a severe abdominal distension. Cytological examination of the peritoneal fluid revealed anaplastic epithelioid cells. Necropsy findings revealed an irregular-shaped mass attached to the pancreas and stomach with numerous nodules covering the intestinal and urinary bladder serosa. The diagnosis was made by histology and immunohistochemistry, with cytokeratin, vimentin and calretinin antibodies. Differential diagnosis with chronic peritonitis and spreading of abdominal primary carcinoma is discussed.

Fatal systemic phaeohyphomycosis in a cat due to Cladophialophora bantiana.

We report a case of fatal systemic mycosis in a 9-year-old cat. Diagnosis of phaeohyphomycosis was made by histology. Morphological and molecular identification of the fungus isolated from the lesions yielded the species Cladophialophora bantiana. This species is well known to be a neurotropic fungus causing cerebral pyogranulomatous lesions in humans. In this case, the lesions were widespread, distributed without the involvement of central nervous system. The origin of systemic manifestation is still unknown and no evidence of immunosuppression was found. It is the first feline case of C. bantiana infection reported in Europe.

Short-term efficiency and safety of gene delivery into canine kidneys.

BACKGROUND: Gene delivery of biologically active molecules to the kidney may have potential therapeutic applications in renal and cardiovascular diseases. Recombinant adenovirus is one of the most efficient vectors for in vivo gene delivery. However, in vivo toxicity at the site of administration has to be evaluated for the successful use of adenovirus-mediated gene transfer. The aim of this study was to document precisely the short-term safety of different routes of intra-renal adenoviral administration and to compare their transduction efficiency. METHODS: Dog puppies were injected with an adenoviral vector expressing the beta-galactosidase reporter gene in both kidneys via three different routes, i.e. intra-renal-ureteral route (IU) and intra-renal-arterial route with (IAC) or without (IA) clamping of the renal vein. Toxicity of viral administration was assayed on day 4 at both physiological and histological levels. Renal samples were monitored for the presence of nuclear beta-galactosidase-expressing cells. RESULTS: All renal physiological parameters (glomerular filtration rate, effective renal plasma flow, and electrolyte excretion fractions) remained stable whatever the route of viral administration. No histological lesion was detected in any of the haematoxylin-eosin-stained kidney sections, and there was no evidence of ischaemia-reperfusion injury in the kidneys subjected to venous clamping. Efficient transgene expression was obtained in dog kidneys following IAC and IU injection of adenoviral vectors. Gene transfer via the IAC route induced gene expression predominantly in the cortical interstitial cells. Retrograde IU adenoviral injection resulted in reduced transduction efficiency compared with the IAC route, with transgene expression occurring mainly in the distal tubular and pyelic epithelial cells. CONCLUSIONS: The two major findings of this study were (i) the absence of acute histological and functional renal alteration following intra-arterial and intra-ureteral injections of adenoviral vectors in both kidneys of healthy dogs, and (ii) the efficiency of transgene expression with specific cellular targeting according to the route of administration.

Vascular and parenchymal Abeta deposition in the aging dog: correlation with behavior.

The behavior of 25 dogs was indirectly assessed by a formal questionnaire (evaluation of Age-Related Cognitive and Affective Disorders-ARCAD), filled out by the owner. The density of diffuse and vascular deposits was evaluated using four anti-Abeta peptide antibodies, in four temporal areas. Parenchymal, diffuse deposits of Abeta42 peptide were found in all aged animals but one. They were Congo red negative and were not immunostained by the anti-Abeta40 antibody, contrary to the vascular deposits. The densities of vascular and parenchymal deposits were not correlated. The ARCAD score was correlated with age, density of Abeta parenchymal and vascular deposits, and with the number of areas containing deposits (extension index). Multivariate analysis showed that the age and the extension index explained most of the variance. Congo red positivity (indicating that the Abeta peptide has the characteristics of an amyloid substance) is limited in the dog to the vascular wall and is associated, as in man, with the deposition of the Abeta 1-40 isoform. Parenchymal Abeta deposition seems to be a common correlate of behavioral problems in aging dogs.

Expression of biologically active atrial natriuretic factor following intrahepatic injection of a replication-defective adenoviral vector in dogs.

Atrial natriuretic factor (ANF) is a potent natriuretic, diuretic, and vasoactive hormone produced and released by atrial cardiomyocytes. We investigated whether adenovirus-mediated ANF gene delivery to dogs leads to a sustained increase in circulating ANF levels resulting in long-lasting biological effects. An adenoviral vector containing the canine ANF cDNA under the control of the Rous sarcoma virus 3' long terminal repeat (AdRSV-ANF) was injected via the intrahepatic route to nonvaccinated 2-month-old dogs. In the first group of four dogs injected with AdRSV-ANF (10(10.2) TCID50), a short-lived increase in plasma ANF concentrations not associated with biological effects occurred 8-10 days after the injection, as compared with four control dogs injected with an adenovirus encoding a luciferase reporter gene (AdRSV-luc). In a second series of experiments, six dogs received AdRSV-ANF at a dose of 10(10) TCID50 and a replication-defective type 5 adenovirus harboring a modified VAI gene (Ad-VAr) at the same dose. Sustained increases in plasma ANF concentrations and urinary cGMP excretion starting on day 2 and persisting until day 20 were seen, as well as concomitant elevations in natriuresis and diuresis, a transient increase in cardiac output, and a delay in body weight gain, as compared with control dogs injected with AdRSV-luc/Ad-VAr. These results show that adenovirus-mediated ANF gene expression can lead to systemic biological effects in dogs, a finding of potential relevance for the treatment of cardiovascular diseases and sodium-retaining disorders.

Delayed infection after immunization with a peptide from the transmembrane glycoprotein of the feline immunodeficiency virus.

Recent advances in the quantitative assessment of viral burden, by permitting the extension of criteria applied to assess the efficacy of vaccines from all-or-none protection to diminution of the viral burden, may allow the identification of original immunogens of value in combined vaccines. Peptides corresponding to three domains of the envelope glycoproteins of feline immunodeficiency virus that are recognized during natural infection were used to immunize cats. After challenge with a primary isolate of feline immunodeficiency virus, the development of acute infection was monitored by quantitative assessment of the viral burden in plasma and tissues by competitive reverse transcription-PCR, by measurement of the humoral response developed to viral components, and by lymphocyte subset analysis. Whereas immunization with two peptides derived from the surface glycoprotein had no effect on the early course of infection, immunization with a peptide derived from the transmembrane glycoprotein delayed infection, as reflected by a diminished viral burden in the early phase of primary infection and delayed seroconversion. This peptide, located in the membrane-proximal region of the extracellular domain, has homology to an epitope of human immunodeficiency virus type 1 recognized by a broadly neutralizing monoclonal antibody. These results suggest that lentivirus transmembrane glycoproteins share a determinant in the juxtamembrane ectodomain which could be of importance in the design of vaccines against AIDS.

A novel BoLA class II molecule with a tissue distribution different from BoLA-DR or BoLA-DQ molecules.

This study was designed to investigate the lymphoid tissue distribution of a new BoLA class II molecule defined by a unique monoclonal antibody H42A. We immunostained various lymphoid organs of 4-month-old Holstein calves with this monoclonal antibody and compared its tissue distribution to the BoLA-DR and BoLA-DQ expressions. Our results demonstrate a unique tissue distribution of the H42A-defined molecules, restricted to epithelial cells of the thymic medulla but extending in the periphery to the different cells involved in antigen presentation (B-cells, macrophages and dendritic cells). The peculiar distribution of this new BoLA class II molecule suggests that it has a specific function.

Histopathological changes in lymph nodes of cats experimentally infected with the feline immunodeficiency virus (FIV).

Twelve specific-pathogen-free (SPF) kittens aged 8-12 weeks were serially infected in pairs every 6 weeks, by the intraperitoneal route, with the feline immunodeficiency virus (FIV). Three additional SPF kittens were kept as controls. The infected animals were killed 10 weeks after inoculation, during the primary phase of the FIV infection. Generalized lymphadenopathy (GL) was observed in the first three pairs of cats. All lymph nodes examined from the 12 infected cats showed histological changes. These included severe follicular hyperplasia with hyperactive follicular centres (FCs) which were either (1) naked, (2) infiltrated by lymphocytes, (3) seen to contain islets of lymphocytic mantle cells, or (4) disrupted by lymphocytes. The presence of both CD4+ and CD8+ T lymphocytes was demonstrated in the FCs immunocytochemically. The distribution of CD4 lymphocytes resembled that in control lymph nodes, but the CD8 cells were increased in number and either scattered or clustered in the follicles. In addition, varying degrees of interfollicular proliferation and medullary plasmacytosis were observed in the lymph nodes. These findings, which were common to all infected animals, represented distinct prodromal manifestations of FIV infection. The changes in lymphocyte subpopulation distribution observed in early FIV infection were reminiscent of findings encountered in human immunodeficiency virus (HIV) infection and reinforce the suggestion that FIV infection is an appropriate model for the study of HIV pathogenesis.

Early haematological and pathological abnormalities of pathogen-free cats experimentally infected with feline immunodeficiency virus (FIV).

Twelve 8-12-week-old specific-pathogen-free (SPF) cats were inoculated intraperitoneally with feline immunodeficiency virus, or with blood from inoculated cats. Three cats of the same age were used as controls. All animals were sacrificed 10 weeks after inoculation. The inoculated cats seroconverted between the 3rd and 6th weeks after inoculation. For 6 infected cats, a decrease in the CD4/CD8 lymphocyte ratio was observed as early as the 6th to the 10th week after inoculation. Granular lymphocytes and atypical cells with cytoplasmic vacuoles and very irregular nuclei were observed in the blood from the 1st to the 10th weeks after inoculation. The only statistically significant differences were obtained 10 weeks after inoculation. Mean leucocyte and lymphocyte numbers were decreased (8000 and 3200 per microliter respectively compared with 14500 and 7200 per microliter before inoculation). The mean CD4/CD8 ratio was also decreased (from 2.60 to 1.50). The percentage of lymphocytes in the bone marrow was increased, reaching 34% as a mean for infected cats as opposed to 20% for control animals. The atypical cells found in the blood were not observed in the marrow. The sternebral bone marrow did not contain lymphoid follicles, as described for HIV infection. Severe follicular hyperplasia was only found in the lymph nodes, but no viral particles could be observed in them.

Functional evaluation of polyarylamide fibers for use in a prosthesis for anterior cruciate ligament replacement in the sheep.

In order to evaluate the potential use of polyarylamide fibers as a prosthetic material for ligament replacement, resected sheep anterior cruciate ligaments were replaced by braided devices routed through a tibial tunnel and over the top of the lateral femoral condyle. Twelve sheep were used and sacrificed between 3 and 12 months. The tissue response to the implant was evaluated histologically. Morphologic features of the fibers and the abraded particles were measured by image analysis. Simultaneously, the tensile properties as well as the creep and fatigue properties of non-implanted prostheses were measured under laboratory conditions. It was shown that the polyarylamide fibers exhibited high strength, a high modulus, but low fatigue abrasion properties. At autopsy, 1 prosthesis was broken, 6 had frayed and 5 were intact. There was no adverse tissue response to the intact fibers. Inflammation was always linked to the presence of polymeric particles. A large bony ingrowth in the tibial tunnel through the prostheses strands was observed. There was no material resorption throughout the experiment. Polyarylamide fibers appear to be a suitable material for ligament replacement provided that abrasion against bone can be avoided.

[A new case of Mycobacterium bovis pulmonary tuberculosis in the dromedary (Camelus dromedarius) in Mauritania]. / Un nouveau cas de tuberculose pulmonaire à Mycobacterium bovis chez le dromadaire (Camelus dromedarius) en Mauritanie.

A case of pulmonary tuberculosis is described in a dromedary from Nouakchott (Mauritania). Gross lesions affected pulmonary parenchyma, diaphragmatic pleura, pericardium and regional lymph nodes: caseo-calcified nodules, miliary tubercles and haemorrhagic "pendeloques". Microscopically lesions were characterised by granulomatous tissue, epithelioid cells, necrotic material in the centre. No Langhans giant cells were seen. Mycobacterium bovis was isolated from these samples.

Preliminary report of familial thymic lymphosarcoma in Holstein calves.

Seventy-three cases of the thymic form of leukosis were found in Holstein calves in five departments of France over a period of five months. Most of the calves had been sired by the same bull. The calves were negative for specific antibodies to bovine leukaemia virus. Morphological studies including light and electron-microscopic cytology, and serological and virological studies of 14 of the cases suggest that the disease was transmitted genetically.

[Tissue effects of pulsed-dye laser lithotripsy. Experimental study on the ureter in dogs]. / Effets tissulaires de la lithotritie par laser pulsé à colorant. Etude expérimentale sur l'uretère du chien.

The tissue effects of pulsed dye laser (Pulsolith) were studied in 10 dog ureters. The results show the absence of ureteric perforation or damage to adjacent organs by the laser irradiation. The only lesions observed were focal hyperplasia of the urothelium and chorion with extremely limited abrasions of the urothelium. The absence of tissue damage of the pulsed dye laser allows it to be used in human clinical practice.