Celso Pilati

In Vivo Manganese Exposure Modulates Erk, Akt and Darpp-32 in the Striatum of Developing Rats, and Impairs Their Motor Function

Manganese (Mn) is an essential metal for development and metabolism. However, exposures to high Mn levels may be toxic, especially to the central nervous system (CNS). Neurotoxicity is commonly due to occupational or environmental exposures leading to Mn accumulation in the basal ganglia and a Parkinsonian-like disorder. Younger individuals are more susceptible to Mn toxicity. Moreover, early exposure may represent a risk factor for the development of neurodegenerative diseases later in life. The present study was undertaken to investigate the developmental neurotoxicity in an in vivo model of immature rats exposed to Mn (5, 10 and 20 mg/kg; i.p.) from postnatal day 8 (PN8) to PN12. Neurochemical analysis was carried out on PN14. We focused on striatal alterations in intracellular signaling pathways, oxidative stress and cell death. Moreover, motor alterations as a result of early Mn exposure (PN8-12) were evaluated later in life at 3-, 4- and 5-weeks-of-age. Mn altered in a dose-dependent manner the activity of key cell signaling elements. Specifically, Mn increased the phosphorylation of DARPP-32-Thr-34, ERK1/2 and AKT. Additionally, Mn increased reactive oxygen species (ROS) production and caspase activity, and altered mitochondrial respiratory chain complexes I and II activities. Mn (10 and 20 mg/kg) also impaired motor coordination in the 3rd, 4th and 5th week of life. Trolox™, an antioxidant, reversed several of the Mn altered parameters, including the increased ROS production and ERK1/2 phosphorylation. However, Trolox™ failed to reverse the Mn (20 mg/kg)-induced increase in AKT phosphorylation and motor deficits. Additionally, Mn (20 mg/kg) decreased the distance, speed and grooming frequency in an open field test; Trolox™ blocked only the decrease of grooming frequency. Taken together, these results establish that short-term exposure to Mn during a specific developmental window (PN8-12) induces metabolic and neurochemical alterations in the striatum that may modulate later-life behavioral changes. Furthermore, some of the molecular and behavioral events, which are perturbed by early Mn exposure are not directly related to the production of oxidative stress.

Evaluation of biochemical, hematological and oxidative parameters in mice exposed to the herbicide glyphosate-Roundup®

ABSTRACT We evaluated the toxicity of hepatic, hematological, and oxidative effects of glyphosate-Roundup® on male and female albino Swiss mice. The animals were treated orally with either 50 or 500 mg/kg body weight of the herbicide, on a daily basis for a period of 15 days. Distilled water was used as control treatment. Samples of blood and hepatic tissue were collected at the end of the treatment. Hepatotoxicity was monitored by quantitative analysis of the serum enzymes ALT, AST, and γ-GT and renal toxicity by urea and creatinine. We also investigated liver tissues histopathologically. Alterations of hematological parameters were monitored by RBC, WBC, hemoglobin, hematocrit, MCV, MCH, and MCHC. TBARS (thiobarbituric acid reactive substances) and NPSH (non-protein thiols) were analyzed in the liver to assess oxidative damage. Significant increases in the levels of hepatic enzymes (ALT, AST, and γ-GT) were observed for both herbicide treatments, but no considerable differences were found by histological analysis. The hematological parameters showed significant alterations (500 mg/kg body weight) with reductions of RBC, hematocrit, and hemoglobin, together with a significant increase of MCV, in both sexes of mice. In males, there was an important increase in lipid peroxidation at both dosage levels, together with an NPSH decrease in the hepatic tissue, whereas in females significant changes in these parameters were observed only at the higher dose rate. The results of this study indicate that glyphosate-Roundup® can promote hematological and hepatic alterations, even at subacute exposure, which could be related to the induction of reactive oxygen species.

Intoxicaçäo experimental pelos frutos de Xanthium cavanillesii (Asteraceae) em bovinos

Os frutos moidos de Xanthium cavanillesii Schouw, foram administrados por via oral, em doses unica ou repetidas, com intervalo semanal, a onze bovinos. Desses, quatro morreram. Doses unicas a partir de 5 g/kg foram letais para bovinos. Dose de 3 g/kg produziu sinais clinicos e recuperacao em um bovino. Repeticoes de 4 doses de 3 g/kg para um bovino e 2 doses de 5 g/kg para outro bovino nao foram toxicas. Foram constatadas hipoglicemia e elevacao dos niveis sericos de aspartato aminotransferase (AST) nos bovinos que apresentaram sinais clinicos da intoxicacao. Os primeiros sinais clinicos nos animais que morreram foram observados entre 6 e 12 horas apos a administracao dos frutos. A evolucao do quadro clinico variou entre 5h30min e 8 horas. O quadro clinico foi semelhante nestes animais sendo que os principais sinais clinicos foram anorexia, apatia, salivacao profusa e tremores musculares. Ocorreram tambem hipomotilidade e atonia ruminal, colicas abdominais, gemidos frequentes, ranger de dentes, sudorese generalizada e endoftalmia. As alteracoes de locomocao observadas foram incoordenacao motora, instabilidade do trem posterior, decubito permanente com movimentos de pedalagem, espasmos musculares e opistotono. As alteracoes respiratorias foram aumento da frequencia respiratoria, respiracao laboriosa com ruidos e momentos de apneia. Finalmente ocorria perda do reflexo palpebral, ausencia de reflexo pupilar e morte. No bovino que se recuperou, os primeiros sinais clinicos foram observados 18 horas apos a administracao e evoluiram num periodo de aproximadamente 72 horas. Neste bovino, atraves de biopsias hepaticas, observou-se necrose hepatica coagulativa centrolobular associada a congestao e hemorragias. Necrose hepatica coagulativa massiva foi observado por biopsias hepaticas em um bovino que morreu, a partir de 12 horas apos a administracao dos frutos, associada com alteracoes nos niveis sericos de glicose e AST. As principais lesoes encontradas na necropsia foram no figado e consistiam de aumento do padrao lobular na superficie capsular e de corte, distensao da vesicula biliar e edema moderado da parede da vesicula biliar. A principal alteracao microscopica era caracterizada por necrose coagulativa centrolobular ou massiva associada a congestao e hemorragia e alteracoes degenerativas nos hepatocitos circunjacentes.

Asymptomatic Cattle Naturally Infected with Mycobacterium bovis Present Exacerbated Tissue Pathology and Bacterial Dissemination

Rational discovery of novel immunodiagnostic and vaccine candidate antigens to control bovine tuberculosis (bTB) requires knowledge of disease immunopathogenesis. However, there remains a paucity of information on the Mycobacterium bovis-host immune interactions during the natural infection. Analysis of 247 naturally PPD+ M. bovis-infected cattle revealed that 92% (n = 228) of these animals were found to display no clinical signs, but presented severe as well as disseminated bTB-lesions at post-mortem examination. Moreover, dissemination of bTB-lesions positively correlated with both pathology severity score (Spearman r = 0.48; p<0.0001) and viable tissue bacterial loads (Spearman r = 0.58; p = 0.0001). Additionally, granuloma encapsulation negatively correlated with M. bovis growth as well as pathology severity, suggesting that encapsulation is an effective mechanism to control bacterial proliferation during natural infection. Moreover, multinucleated giant cell numbers were found to negatively correlate with bacterial counts (Spearman r = 0.25; p = 0.03) in lung granulomas. In contrast, neutrophil numbers in the granuloma were associated with increased M. bovis proliferation (Spearman r = 0.27; p = 0.021). Together, our findings suggest that encapsulation and multinucleated giant cells control M. bovis viability, whereas neutrophils may serve as a cellular biomarker of bacterial proliferation during natural infection. These data integrate host granuloma responses with mycobacterial dissemination and could provide useful immunopathological-based biomarkers of disease severity in natural infection with M. bovis, an important cattle pathogen.

Antimetastatic activity and low systemic toxicity of tetradecyl gallate in a preclinical melanoma mouse model

SummaryGallates with eight or more carbon atoms in the lateral chain show potent anticancer activity against various cell lines. However, studies regarding the in vivo antimelanoma activity of tetradecyl gallate (C14) have not yet been reported. In this study an evaluation of the ability of C14 to inhibit metastasis, using lung metastases as a model, was carried out. The experimental mouse melanoma model was established by intravenous injection of metastatic B16F10 melanoma cells. The systemic toxicity of C14 was evaluated in vivo by monitoring the weight, survival, biochemical and hematological parameters, and through histological analysis. It was observed that C14 decreased lung metastasis in vivo by 80% and increased the survival rate of the animals without toxic effects. Additionally, C14 induced cytotoxic effects on B16F10 cells, inhibited the inter-cellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) expression, and significantly decreased cell adhesion. These results reveal that C14 has potent antimetastatic ability and is a good candidate for further study as a potential therapeutic agent for tumor metastases.

Natural Infection of the Wild Canid Lycalopex gymnocercus by the Protozoan Rangelia vitalii, the Agent of Canine Rangeliosis

Abstract Rangelia vitalii is a piroplasmid that causes canine rangeliosis, a severe hemorrhagic disease of domestic dogs in South America. We report about R. vitalii infecting a pampas fox (Lycalopex gymnocercus). The fox, which developed a fatal illness, was also infected by Hepatozoon canis and Capillaria hepatica.

Capillaria hepatica in Puma concolor: First Report in Brazil

Abstract Capillaria hepatica was detected by histopathologic diagnosis in two cougars that were shot in April 2008 in Painel, Santa Catarina, Brazil. Macroscopic analysis of their livers revealed the presence of diffuse granulomas, and the histopathologic analysis indicated the presence of C. hepatica eggs, surrounded by mononuclear inflammatory cell infiltrate, small foci of necrosis, and mild-to-moderate fibrosis. This is the first report of C. hepatica in cougars (Puma concolor) in Brazil.

Surto autóctone de leishmaniose visceral canina no Estado de Santa Catarina

The present study reports the first outbreak of autochthonous canine visceral leishmaniasis in Florianopolis, Santa Catarina, southern Brazil. Following the report of two cases of CVL, the Control Center of Zoonotic Diseases conducted a serological survey by ELISA and IFAT assays in seven districts of the Santa Catarina Island. Eleven seropositive dogs of autochthonous transmission were used in the present study. Infection by Leishmania sp. was confirmed by parasitological examination of bone marrow, liver, spleen and lymph nodes, culture in Schneiders medium and PCR. Leishmania sp. isolates were characterized by PCR-RFLP and hybridization with specific probes, allowing for the identification of Leishmania infantum. Autochthonous transmission of this disease in an area with high tourist traffic presents a major public health concern and signifies the emergence of an important zoonosis in southern Brazil. Therefore, the implementation of surveillance and control measures is imperative to prevent the spread of the disease among the canine population as well as transmission to the human population.

Intoxicação experimental por Senecio brasiliensis (Asteraceae) em eqüinos

Fourteen 4 to 22-year-old mixed breed horses weighing 230-475 kg were experimentally fed the dried aerial parts of Senecio brasiliensis (Spreng.) collected in its sprouting stage. A 15-year-old horse served as non-plant-fed control. Small amounts of the dried plant material were admixed in the ration given to the horses; larger amounts were grounded, admixed with water and force fed through nasogastric intubation. Liver biopsies were periodically performed in 11 horses. Nine horses died with signs or lesions of the poisoning after having received amounts of the plant corresponding to 0.87%, 1.5% (single administrations), 1.74% (two weekly administrations), 3.0% (three daily administrations), 7.42% (17 weekly administrations), 8.9% (284 daily administrations), 9.66% (82 daily administrations) and 9.30% (43 weekly administrations) of their body weight. Two horses which received amounts of the plant corresponding to 15.0% (30 and 60 daily administrations) of their body weight died during the experiments due to unrelated causes. Three horses which received amounts of the plant corresponding to 0.5% and 1.0% (single administrations), and 15.0% (240 daily administrations) of their body weight, and the control horse survived without any clinical signs. The disease induced by the plant had a clinical course of 1-30 days and was characterized by anorexia, jaundice and neurological signs of hepatic encephalopathy. Weight loss was observed in the more protracted cases. Necropsy findings included marked enhancement of the lobular pattern of the livers or those were firm and dark-red. Hemorrhages were frequent and more conspicuous on the subcutis, serosal surfaces and in the gastrointestinal mucosa. Edema occurred in the submucosa of the gastrointestinal tract and in body cavities. Histologically, the livers of horses that ingested relatively larger amounts of the plant for short periods of time had zonal coagulative necrosis and centrilobular to massive hemorrhages. Moderate to marked hepatomegalocytosis and mild to moderate fibrosis were seen in 4 horses which ingested small amounts of the plant for longer periods. Cholestasis and hemosiderosis were observed in the liver of 8 horses, neutrophilic aggregates in 6 and acidophilic intranuclear pseudo-inclusion bodies in hepatocytes of 3 horses. Changes suggestive of hepatic encephalopathy were observed in the brain of 6 horses. The earliest detected change in the liver biopsies was vacuolization of hepatocyte nuclei followed by apoptotic loss of hepatocytes, hepatomegalocytosis, infiltration of neutrophils and centrolobular necrosis. Occasionally hepatocellular acidophilic intranuclear pseudo-inclusion bodies and, in more protracted cases, slight fibrosis were seen. No changes were observed in the liver biopsies of the 3 plant-fed horses that survived, nor on the 2 horses that died of unrelated causes. The control horse had no clinical signs.

Estudo morfológico de fígado de bovinos abatidos em frigoríficos industriais sob inspeção estadual no Oeste e no Planalto de Santa Catarina, Brasil

Criteria for condemnation and liberation of organs submitted to the official meat inspection services have been controversial, it is argued that organs witch do not present gross lesions may still have certain degree of pathological changes under microscopic scrutiny; conversely, organs rejected on microscopic exam may reveal normalcy under histological evaluation. A gross and histological morphologic study was conducted in bovine livers during meat inspection in commercial slaughter; bovine livers were allotted in two groups: condemned and non-condemned, according to the Animal Standard Meat Inspection (SIS) of the State of Santa Catarina, Brazil. Liver fragments were fixed in 10% neutral formalin and processed for routine histopathological examination. The objectives were: to establish the main reasons for condemnation of bovine livers in the meat inspection routine of SIS, to evaluate livers from both groups by histological examination and to identify the possible etiologies responsible for condemnation. According to the SIS, the reasons for condemnation were: telangiectasis (32.2%), fasciolosis (18.5%), abscesses (18.0%), irregular and bright spots (12.6%), adherence between liver and diaphragm (6.0%), yellow and friable liver (4.2%), dark or pale spots (3.6%), nodules (1.8%) and other causes (3.0%). Under microscopic study livers from condemned group showed telangiectasis (25.7%), abscesses (18.0%), fasciolosis (16.1%), capsular fibrosis (13.2%), random necrosis (8.4%), degeneration (3.6%), inflammatory infiltrate (2.4%), neoplasia (1.8%), no changes (7.2%) and miscellaneous changes (3.6%). Among livers from the non condemned group, 73% did not have microscopic changes; however, inflammatory infiltration (12.6%), necrosis (7.8%), telangiectasis (4.8%), fasciolosis (0.6%) and miscellaneous lesions (1.2%) were detected in the remaining 27%. In conclusion, inaccuracy was detected in the meat inspection routine of SIS since the microscopic changes observed in 27% of the non-condemned livers were not detected on gross examination and so affected organs were liberated for human consumption. Conversely several livers among the condemned groups were unnecessarily rejected, consequently causing importantly economic losses.