Tumor necrosis factor-alpha and virus expression in the central nervous system of cats infected with feline immunodeficiency virus.

Cytokine disregulation has been implicated in the pathogenesis of lentivirus-induced diseases. In the present study, 18 specific pathogen free (SPF) cats were inoculated with feline immunodeficiency virus (FIV) Petaluma strain and sacrificed at different times post-infection. Five additional SPF cats were used as controls. The cell localization of the cytokine tumor necrosis factor alpha (TNF-alpha) in the central nervous system (CNS) was determined by immunohistochemical and morphometric analyses with a polyclonal rabbit anti-human TNF-alpha antibody. TNF-alpha and FIV RNA were measured using competitive reverse transcriptase polymerase chain reaction (PCR) assays and the number of proviral genomes was estimated by competitive PCR. Portions of frontal cortex were collected from each animal and both formalin-fixed and snap-frozen and stored at -80 degrees C until used. The results showed that TNF-alpha is present mainly in astrocytes and microglial cells. Morphometric analysis showed that areas of TNF-alpha production increased in the early phases of infection. Molecular analyses demonstrated that the kinetics of proviral loads in the CNS were comparable to what observed in lymph nodes and peripheral blood mononuclear cells, with the peaks in the early and late stages of infection. A positive correlation was found between viral parameters and TNF-alpha transcription, the strongest relationship was found between the transcription of the cytokine and viral RNA load. These results confirm that invasion of CNS by FIV occurs soon after virus exposure and that during this phase there is an increase of local viral loads with concomitant up-regulation of TNF-alpha expression. During the asymptomatic phase viral replication remains low in spite of the progression of CNS alterations. The dissociation between the viral load and the lesions observed suggests the importance of an indirect mechanism for the progression of these lesions, even if TNF-alpha seems to play a role particularly in the early phase of infection.

Neospora caninum infection in a Bernese cattle dog from Italy.

A cutaneous nodule associated with Neospora caninum infection was diagnosed in a 5-year-old male Bernese cattle dog from Italy. The ulcerative lesion was 2-3 cm wide located in the skin of the tarsal region. Haematological values were normal and the dog did not show any neurological abnormalities. The dermal lesion consisted of a diffuse necrotic dermatitis with a dense infiltrate of mostly neutrophils and macrophages, surrounded by a fibrous wall. Histological sections revealed numerous tachyzoites of N. caninum scattered throughout the tissue. Diagnosis was confirmed both by immunohistochemical staining and electron microscopic examination. The dog had a 1:640 IFAT titre to N. caninum. Four weeks after surgical excision new subcutaneous nodules reappeared. The cutaneous lesions resolved following 21 days of therapy with clindamycin hydrochloride. These observations demonstrate the presence of N. caninum in Italy and confirm that neosporosis should be considered in the differential diagnosis of pyogranulomatous dermatitis in dogs. Clindamycin may be an effective treatment for cutaneous neosporosis.

Neuropathology in cats experimentally infected with feline immunodeficiency virus: a morphological, immunocytochemical and morphometric study.

Neuropathological changes have been described associated with feline immunodeficiency virus (FIV) infection. The objective of our study was to characterize the lesions found in the brain and spinal cord of experimentally FIV-infected cats and to quantify, by morphometric analysis, the intensity of gliosis found in these subjects at different time post infection (pi). The brains and spinal cords appeared grossly normal. Gray matter of cortical and subcortical structures showed a moderate to pronounced gliosis particularly in all cerebral cortex and hippocampus. Morphometric analysis demonstrated that GFAP immunoreactivity was markedly higher in infected animals. Gliosis was present 15 days pi and did not appear to progress during the infection, whereas neuronal changes when present were observed only in long-term infected animals (15-23 months pi). In a large proportion of infected cats a diffuse gliosis of white matter and vacuolar myelinopathy was also present. Despite some discrepancies observed between neuropathological changes in FIV-infected animals and HIV-infected individuals, the presence in the cerebral cortex of cats with FIV infection of alterations similar to those observed in AIDS patients demonstrates that FIV is an interesting animal model particularly that may be useful for clarifying the pathogenesis of neuropathological changes associated with HIV infection.

Effects of IAL and Healon on postoperative intraocular pressure after cataract surgery with intraocular lens implantation.

A randomized controlled study was done on 60 patients, divided into three groups, who underwent extracapsular cataract extraction and intraocular lens implantation. The aim of the study was to investigate the effect on postoperative intraocular pressure (IOP) of IAL left in situ compared with IAL or Healon removed after surgery. The IOP was monitored three, six, 12, and 24 hours and seven days after surgery. In general, there was a similar trend in IOP in the three groups with increasing values starting three hours after surgery and normal values reached around 24 hours. No significant statistical difference was found when IAL was removed compared with Healon removed or IAL left in situ compared with Healon removed. No differences were found in the presence of an inflammatory reaction or its severity among the three groups 24 hours after surgery. We believe that IAL can be used in cataract surgery without removing it at the end of the operation, thus simplifying surgical maneuvers and reducing surgical risks.