Prognostic indicators for dogs with dilated cardiomyopathy

The purpose of this study was to investigate the prognostic value of various clinical, ECG, echocardiographic, and Doppler echocardiographic variables in dogs with dilated cardiomyopathy. The relationship to survival of 11 variables was evaluated in 63 dogs. Studied variables were age at time of diagnosis, class of heart failure (HF), dyspnea, ascites, atrial fibrillation (AF), ejection fraction (EF), E-point septal separation, end-diastolic volume index, end-systolic volume index (ESV-I), and restrictive or nonrestrictive transmitral flow (TMF) pattern. Median survival time was 671 days (lower 95% confidence limit, 350 days). Survival curves showed that severity of HF, ascites, ESV-I greater than 140 mL/m2, EF less than 25%, and restrictive TMF pattern had a significant negative relation to survival time. Thirty-nine dogs with both sinus rhythm and AF presented adequate TMF recordings; in these dogs, after stratification by TMF pattern, the restrictive TMF pattern was the most important negative prognostic indicator. We conclude that in dogs with dilated cardiomyopathy the restrictive TMF pattern appears to represent a useful prognostic indicator. Class of HF, ascites, ESV-I, and EF are also useful indexes if an adequate TMF pattern is not recorded.     

Mydriatic effect of topically applied rocuronium bromide in tawny owls (Strix aluco): comparison between two protocols

Objective To evaluate the mydriatic efficacy of a neuromuscular blocking agent (rocuronium bromide) applied topically to only one eye of nocturnal birds of prey and to assess for any general and/or local adverse effects due to its use. Animal studied Twelve healthy adult tawny owls (Strix aluco) were randomly divided in two groups. Procedures Six birds (Group 1) received a single dose of 0.35 mg of rocuronium bromide. The second group of subjects (Group 2) received two doses of 0.35 mg of rocuronium bromide (total 0.70 mg/eye). In both groups, the curariform agent was instilled topically. Pupil diameter was measured with a pupillary gauge in 10 min intervals for a total of 100 min and then every 20 min for a total of 240 min. The assessment of the pupillary light reflex was performed using a standard light source during pupillary size recording. Results Maximal pupillary diameter was 11.5 ± 0.3 mm for Group 1 and 11.0 ± 0.6 mm for Group 2 and no statistically significant differences were detected among the two groups. The maximal pupillary diameter was achieved at T80 for Group 1, and at T60 for Group 2. A complete fundus examination was possible on all treated eyes of subjects of both groups. The drug did not cause any noticeable adverse effects in any of the examined birds. Conclusion Results of the present study suggest that a single topical administration of 0.35 mg of rocuronium bromide to the eyes of healthy tawny owls results in sufficient mydriasis to allow for a complete examination of the fundus.     

Effects of competition on acute phase proteins and lymphocyte subpopulations – oxidative stress markers in eventing horses

The aim of the study was to evaluate markers of the acute phase response (APR) in eventing horses by measuring acute phase proteins (APP) (haptoglobin, Hp, and serum amyloid A, SAA), lysozyme, protein adducts such as pentosidine‐like adducts (PENT), malondialdehyde adducts (MDA), hydroxynonenal adducts (HNE) and total advanced glycation/glycoxidation end products (AGEs), complete blood count and lymphocyte subpopulations (CD4+, CD8+ and CD21+) both at rest and at the end of an eventing competition. Blood samples were collected from eight Warmblood horses (medium age 10 ± 3) during an official national 2‐day event competition at rest (R) and 10 min after the arrival of the cross‐country test on the second day. Exercise caused a significant increase in red blood cell number, haemoglobin, packed cell volume, neutrophils, white blood cell and lymphocyte number; however, these values remained within the normal range. The CD4+ and CD8+ cells significantly increased, whereas the CD21+ lymphocytes decreased; a significant increase in serum SAA, lysozyme and protein carbonyl derivates was also observed. Two‐day event causes significant changes in APR markers such as lysozyme, protein carbonyl derivates (HNE, AGEs, PENT) and lymphocyte subpopulations. The data support the hypothesis that 2‐day event may alter significantly APR markers. Limitations of the study were the relatively small sample size and sampling time conditioned by the official regulations of the event. Therefore, further studies are needed to investigate the time required for recovery to basal values in order to define the possible effects on the immune function of the athlete horse.     

In situ characterization of the granulomatous immune response with time in nonhealing lesional skin of Leishmania braziliensis-infected rhesus macaques (Macaca mulatta)

We have recently introduced a macaque (Macaca mulatta) model of Leishmania braziliensis-induced self-healing cutaneous leishmaniasis in which the T cell-mediated inflammatory response effectively promotes parasite clearance and granuloma resolution. Here we show that macaques infected with a highly pathogenic L. braziliensis strain displayed longstanding granulomatous lesions which lasted until the end of the observation period (52 weeks). Immunoperoxidase staining of representative tissue sections indicated that distinct cell populations (CD3, CD4, CD8, CD20, Foxp3, CD20, CD68, HLA-DR, CCL2, and CXCL-10) change uniformly during infection, suggesting that the same components of the local immune response are working in unison. This model also confirmed that granuloma formation is orchestrated by diverse inflammatory mediators that are important for T helper type 1 (Th1) cell development and macrophage effector functions. Cytometry analysis of ex vivo granuloma-derived leukocytes revealed accumulation of distinct functional subsets of effector and regulatory T cells into the inflamed skin. We provide evidence that local interleukin (IL)-10 production by both Foxp3(+) and Foxp3(-) CD4(+) T subsets is likely important in promoting lesional granuloma maintenance. Further studying the immune suppression mechanisms that induces granulomas in L. braziliensis-infected macaques may reveal new opportunities for therapeutic control of this important human disease.     

Secretion of multi-protein migratory complex induced by Toxoplasma gondii infection in macrophages involves the uPA/uPAR activation system

Toxoplasmosis is a world wide spread zoonosis caused by Toxoplasma gondii, an obligate intracellular parasite that is able to disseminate into deep tissues and cross biological barriers, reaching immunoprivileged sites such as the brain and retina. The parasite is able to infect macrophages and dendritic cells for dispersal throughout the body. However, the molecular mechanisms or outcomes of the subversion of the host cell are largely unknown. Recently our group established that metalloproteinases are involved in migration of infected macrophages. Herein, we evaluated the recruitment of host invasive machinery components in T. gondii infected murine macrophages. We showed by immunoprecipitation assays that MMP-9, CD44 TIMP-1 and uPAR were secreted as a multi-protein complex by infected macrophages. Zymographic analysis revealed that MMP-9 was present in its pro- and active form. Moreover, inhibition of uPA/uPAR pathway by PAI-1 decreased secretion of MMP-9 active forms, as well those associated to uPAR and TIMP-1, but not to CD44. Data presented here suggest that MMP-9 is secreted as a multiprotein complex by T. gondii infected macrophages, similar to that observed in metastatic cells. We further speculate that uPA/uPAR system is involved in the expression/secretion of complexes containing active MMP-9 forms.     

Mammary carcinoma in a tiger (Panthera tigris): morphological and immunohistochemical study

The histologic and immunohistochemical features of a case of mammary gland carcinoma are described in a 14-yr-old female tiger (Panthera tigris). Immunoreactivity to estrogen receptor (ER), progesterone receptor (PR), tumoral protein 53 (p53), vascular endothelial growth factor (VEGF), human epidermal growth factor receptor 2 (HER-2), and cyclooxigenase-2 (COX-2) was investigated. Neoplastic cells were negative for ER, PR, and p53 but showed positivity for VEGF, HER-2, and COX-2, both in the primary and the metastatic lesions. Histopathologic findings and immunohistochemistry results suggested that the malignant behavior of the reported case could be comparable with some aggressive cat mammary carcinomas.     

Postpartum toll-like receptors and β-defensin 5 mRNA levels in the endometrium of Holstein cows

Toll-like receptors (TLRs) and β-defensins are important components of the innate immune system. This study aimed to evaluate endometrial mRNA levels of TLRs (1/6, 2, 4, and 5) and β-defensin 5 in Holstein cows by quantitative real time RT-PCR. Uterine biopsies were performed from 6 to 12 h after parturition, and cows were divided into two groups: (i) cows with placental retention and clinical signs of uterine infection until 45 days postpartum (n=10) or (ii) cows with normal puerperium (n=10). All cows had detectable levels of TLRs and β-defensin 5 mRNAs, but these levels did not differ between groups (P>0.05). Levels of TLR4 mRNA had a positive and significant correlation with the time required for uterine involution in both groups.     

Can fleas from dogs infected with canine visceral leishmaniasis transfer the infection to other mammals?

In order to investigate the possible role of dog fleas in the transmission of trypanosomatids, ectoparasites were removed from 59 dogs testing positive for canine zoonotic visceral leishmaniasis according to the indirect fluorescent antibody test (IFAT). Of the fleas collected, 4/207 (1.9%) showed the presence of promastigotes in smears stained by Giemsa, whilst 43/144 (29.9%) exhibited positive polymerase chain reaction (PCR) amplification assays for Leishmania DNA. Fleas (409) from 9 Leishmania chagasi-infected dogs, each hosting more than 20 fleas per animal, were macerated and administered by peritoneal injection or orally to 36 hamsters. After 6 months, the 30 surviving hamsters were sacrificed and liver and spleen fragments were removed for PCA assay and to produce imprint smears, whilst blood samples were subjected to IFAT assay. Sixteen hamsters tested positive for Leishmania infection, 14 on the basis of PCR amplification and four by IFAT assay (two animals testing positive in both assays). Of the infected hamsters, 11/16 (68.7%) had been infected peritoneally and 5/16 (31.2%) orally. The imprint smears for all animals were, however, negative. Since both PCR and IFAT could present cross-reactivity for Leishmania and Leptomonas, the possibility of oral transmission of L. chagasi by fleas cannot be proven unambiguously even though the hamsters developed infection.