Efeitos colaterais do uso da ribavirina, prednisona e DMSO em cães naturalmente infectados pelo vírus da cinomose

Quinoline, with the active site of 8-hydroxyl, efficiently inhibits Micropterus salmoides rhabdovirus (MSRV) infection in vitro and in vivo

Micropterus salmoides rhabdovirus (MSRV) is an significant pathogen that causes high mortality and related economic losses in bass aquaculture. There is no effective or approved therapy to date. In this study, we evaluated the anti-MSRV effects of 22 quinoline derivatives in grass carp ovary (GCO) cells. Among these compounds, 8-hydroxyquinoline exhibited valid inhibition in decreasing MSRV nucleoprotein gene expression levels of 99.3% with a half-maximal inhibitory concentrations (IC₅₀ ) value of 4.66 μM at 48 h. Moreover, 8-hydroxyquinoline significantly enhanced a protective effect in GCO cells by reducing the cytopathic effect (CPE). By comparing the anti-MSRV activity of 22 quinoline derivatives, we found that 8-hydroxyquinoline possessed the efficient active site of 8-hydroxyl and inhibited MSRV infection in vitro. For in vivo studies, 8-hydroxyquinoline via intraperitoneal injection exhibited an antiviral effect in MSRV-infected largemouth bass by substantially enhancing the survival rate by 15.0%. Importantly, the viral loads in the infected largemouth bass notably reduced in the spleen on the third days post-infection. Overall, 8-hydroxyquinoline was considered to be an efficient agent against MSRV in aquaculture.

Contribution of astrocytes and macrophage migration inhibitory factor to immune-mediated canine encephalitis caused by the distemper virus

Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine that is produced by many cell types in situations of homeostasis or disease. One of its functions is to act as a proinflammatory molecule. In humans, several studies have shown that MIF levels become elevated in the serum, urine, cerebrospinal fluid and tissues of patients with chronic inflammatory diseases (systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, sepsis, atheromas, diabetes and cancer). In dogs, distemper is a viral infectious condition that may lead to demyelination and inflammation in the central nervous system (CNS). In addition to the action of the virus, the inflammatory process may give rise to lesions in the white matter. Therefore, the objectives of the present study were to evaluate the role of MIF in the encephalitis that the canine distemper virus causes and to compare this with immunodetection of major histocompatibility complex-II (MHC-II), CD3 T lymphocytes, MMP-9 and glial fibrillary acidic protein (GFAP; astrocytes) in demyelinated areas of the encephalon, in order to ascertain whether these findings might be related to the severity of the encephalic lesions. To this end, a retrospective study on archived paraffinized blocks was conducted, in which 21 encephala from dogs that had been naturally infected with the canine distemper virus (infected group) and five from dogs that had been free from systemic or CNS-affecting diseases (control group) were used. In the immunohistochemical analysis on the samples, the degree of marking by GFAP, MHC-II, MMP-9 and MIF was greater in the demyelinated areas and in the adjacent neuropil, and this was seen particularly in astrocytes. Detection of CD3 was limited to perivascular cuffs. In areas of liquefactive necrosis, Gitter cells were positive for MMP-9, MIF and MHC-II. Hence, it was concluded that activated astrocytes influenced the afflux of T lymphocytes to the encephalon (encephalitis). In the more advanced phases, activated phagocytes in the areas of liquefactive necrosis (Gitter cells) continued to produce inflammatory mediators even after the astrocytes in these localities had died, thereby worsening the encephalic lesions. Distemper virus-activated astrocytes and microglia produce MIF that results in proinflammatory stimulus on glial cells and brain-infiltrating leukocytes. Therefore, the effect of the inflammatory response is potentiated on the neuropil, resulting in neurological clinical signs.

Combined use of ivermectin, dimethyl sulfoxide, mineral oil and nematophagous fungi to control Rhabditis spp

Rhabditis spp., is a nematode known to cause otitis externa, an infection difficult to control, in cattle reared within tropical regions. The objective of this study was to assess the combined use of ivermectin 1%, dimethyl sulfoxide 1% and mineral oil 100% containing nematophagous fungi of both Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34) species to control in vitro Rhabditis spp. Thus, 12 experimental groups were designed with eight replicates each: G1 (nematodes + AC001); G2 (nematodes + NF34); G3 (nematodes + ivermectin 1%/positive control); G4 (nematodes + dimethyl sulfoxide 1%/positive control); G5 (nematodes + mineral oil 100%/positive control); G6 (nematodes + AC001 + ivermectin 1%); G7 (nematodes + NF34 + ivermectin 1%); G8 (nematodes + AC001 + mineral oil 100%); G9 (nematodes + NF34 + mineral oil 100%); G10 (nematodes + AC001 + dimethyl sulfoxide 1%); G11 (nematode + NF34 + dimethyl sulfoxide 1%); G12 (nematode + distilled water/negative control). The results demonstrated that all experimentally treated groups differed statistically (p < 0.01) from the control group. In the present study, the use of dimethyl sulfoxide 1% and mineral oil 100% in conjunction with conidia fungi portrayed noteworthy outcomes, which represents a future premise for the combined use of nematophagous fungi within these vehicles in both controlling Rhabditis spp.