N-methyl-N-nitrosourea toxicology: data from a rat model

Introduction: N-methyl-N-nitrosourea (MNU) is the oldest member of the nitroso-compounds that can alkylate DNA. MNU induces tumor development in several organs, depending on the animals’ specie and strain, dose, route, and age at administration. Aims: This study aimed to address the toxicological effects of MNU administration in female rats. Methods: Twelve Sprague-Dawley female rats were divided into two experimental groups: MNU (n=10) and control (n=2). At seven weeks of age, animals from group MNU received an intraperitoneal administration of the carcinogen MNU, at a dose of 50 mg/Kg. Animals from group control received an administration of vehicle (saline solution 0.9%). Animals were humanely sacrificed 18 weeks after MNU or vehicle administration by intraperitoneal injection of xylazine and ketamine, followed by exsanguination by cardiac puncture. A complete necropsy was performed. Heart, lungs, liver, spleen, kidneys, adrenal glands, clitoral glands, and lymph nodes were removed and immersed in buffered formalin for histopathological analysis. Results: Animals from group MNU developed a total of 21 mammary tumors., The organs of animals from group MNU presented a higher number of lesions with higher grade, when compared with the organs of animals from group control. Hyalinization, coagulative myocytolysis, congestion hemorrhage and hyperemia were observed in the heart. Lungs exhibited interstitial inflammation, arteriolosclerosis, arteriosclerosis, congestion, and hyperemia. Interstitial inflammation, congestion and cholestasis were observed in the liver. The spleen presented interstitial inflammation, congestion, hemosiderosis and hyperemia. Congestion, hyperemia, blebbing, hydropic degenerescence, hyaline casts and cystic dilations were found in the kidneys. Adrenal glands presented hyperplasia, congestion, and hydropic degeneration; while clitoral glands presented interstitial fibrosis, ductal dilation, interstitial inflammation, and hyperemia. Infiltrate and congestion were observed in the lymph nodes. Conclusions: The higher number and higher grade of the lesions in group MNU were due to the carcinogenic action of the chemical agent MNU

Histopathological features of organs in a rat model of mammary carcinogenesis: a reference database

Mammary tumors’ development was induced through the intraperioneal administration of the carcinogen N-methyl-N-nitrosourea (MNU). Animals from group control were injected with the vehicle (saline solution). Animals were sacrificed at 25 weeks-old and the organs were histopathologically evaluated. A higher number of lesions was observed in the organs of animals from group MNU. The animals from group control did not present any lesion in lymph nodes. Independently of the experimental group, the internal organs presented hemodynamic alterations, degenerative and inflammatory changes. Hemodynamic changes may be consequence of euthanasia method. As expected, the higher number and the higher grade of the lesions in group MNU were due to the carcinogen administration

In vivo and in vitro effects of RAD001 on bladder cancer

Objective: To evaluate the influence of Everolimus (RAD001) on chemically induced urothelial lesions in mice and its influence on in vitro human bladder cancer cell lines. Methods: ICR male mice were given N-butyl-N-(4-hydroxybutyl) nitrosamine in drinking water for a period of 12 weeks. Subsequently, RAD001 was administered via oral gavage, for 6 weeks. At the end of the experiment, all the animals were sacrificed and tumor development was determined by means of histopathologic evaluation; mammalian target of rapamycin (mTOR) expressivity was evaluated by immunohistochemistry. Three human bladder cancer cell lines (T24, HT1376, and 5637) were treated using a range of RAD001 concentrations. MTT assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry were used to assess cell proliferation, apoptosis index, and cell cycle analysis, respectively. Immunoblotting analysis of 3 cell line extracts using mTOR and Akt antibodies was performed in order to study the expression of Akt and mTOR proteins and their phosphorylated forms. Results: The incidence of urothelial lesions in animals treated with RAD001 was similar to those animals not treated. RAD001 did not block T24 and HT1376 cell proliferation or induce apoptosis. A reduction in cell proliferation rate and therefore G0/G1 phase arrest, as well as a statistically significant induction of apoptosis (P 0.001), was only observed in the 5637 cell line. Conclusion: RAD001 seems not to have a significant effect on chemically induced murine bladder tumors. The effect of RAD001 on tumor proliferation and apoptosis was achieved only in superficial derived bladder cancer cell line, no effect was observed in invasive cell lines

Parasitas Pulmonares em Pequenos Ruminantes: Mais Conhecimento, Melhor Diagnóstico

A pneumonia parasitária por nematodes da superfamília Trichostrongyloidea e Metastrongyloidea, também conhecida como estrongilose pulmonar, apresenta elevada prevalência nalgumas regiões geográficas, mas tem merecido pouca atenção por parte dos Médicos Veterinários e investigadores [1,2]. Os estudos de prevalência disponíveis assentam predominantemente na deteção de lesões pulmonares em matadouro e no diagnóstico in vivo, com recurso à técnica de Baermann. No entanto, a velocidade de processamento das carcaças no matadouro limita substancialmente a probabilidade de deteção de lesões características de estrongilose e a técnica de Baermann, apesar de ser considerada a gold standard para diagnóstico in vivo, apresenta uma sensibilidade que não ultrapassa os 90%, é demorada e exige conhecimentos técnicos para a sua correta execução [3,4,5]. Em Portugal, do ponto de vista clínico, estas parasitoses são subdiagnosticadas, na medida em que a pesquisa de parasitas pulmonares raramente é incluída nos testes parasitológicos de rotina, requisitados pelos Médicos Veterinários aos laboratórios [6], o que, associado à escassez de investigação científica na área, cria uma lacuna no conhecimento da distribuição geográfica e de outros aspetos da epidemiologia destas infeções, comprometendo o seu tratamento e controlo. Apesar da desparasitação regular (anual ou bianual) de pequenos ruminantes estar amplamente instituída, alguns princípios ativos frequentemente utilizados para o controlo de parasitas gastrointestinais são pouco eficazes nos nematodes pulmonares, particularmente nalgumas espécies da família Protostrongylidae, pelo que a abordagem terapêutica deve ser integrada e assente no diagnóstico parasitológico prévio. Assim, este trabalho, assente na revisão da bibliografia disponível e na experiência prática dos técnicos e investigadores do Laboratório de Anatomia Patológica da Escola Superior Agrária de Viseu (LAP, ESAV) e do Laboratório de Parasitologia Victor Caeiro da Universidade de Évora (LPVC, UE), pretende sensibilizar os profissionais de saúde animal e investigadores dedicados aos pequenos ruminantes para as infeções por nematodes pulmonares, fornecendo ainda ferramentas de diagnóstico laboratorial acessíveis e orientações para a abordagem terapêutica e profilática.info:eu-repo/semantics/publishedVersio

Long-term treatment with chaethomellic acid A reduces glomerulosclerosis and arteriolosclerosis in a rat model of chronic kidney disease

The high prevalence of end-stage renal disease emphasizes the failure to provide therapies to effectively prevent and/or reverse renal fibrosis. Therefore, the aim of this study was to evaluate the effect of long-term treatment with chaethomellic acid A (CAA), which selectively blocks Ha-Ras farnesylation, on renal mass reduction-induced renal fibrosis. Male Wistar rats were sham-operated (SO) or subjected to 5/6 renal mass reduction (RMR). One week after surgery, rats were placed in four experimental groups: SO:SO rats without treatment (n = 13); SO + CAA: SO rats treated with CAA (n = 13); RMR:RMR rats without treatment (n = 14); and RMR + CAA:RMR rats treated with CAA (n = 13). CAA was intraperitoneally administered in a dose of 0.23 μg/kg three times a week for six months. Renal fibrosis was evaluated by two-dimensional ultrasonography and histopathological analysis. The kidneys of the RMR animals treated with CAA showed a significantly decrease in the medullary echogenicity (p < 0.05) compared with the RMR rats that received no treatment. Glomerulosclerosis and arteriolosclerosis scores were significantly lower (p < 0.001) in the RMR + CAA group when compared with the RMR group. There were no significant differences in interstitial fibrosis, interstitial inflammation and tubular dilatation scores between the RMR + CAA and RMR groups. These data suggest that CAA can be a potential future drug to attenuate the progression of chronic kidney disease.This work is supported by : European Investment Funds by FEDER/COMPETE/POCI– Operacional Competitiveness and Internacionalization Programme, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013; and by European Investment Funds by FEDER/COMPETE/POCI– Operacional Competitiveness and Internacionalization Programme, under Project POCI-01-0145-FEDER-016728 and National Funds by FCT - Portuguese Foundation for Science and Technology, under the project PTDC/DTP-DES/6077/2014.info:eu-repo/semantics/publishedVersio

Quercus spp. extract as a promising preventive or therapeutic strategy for cancer: A systematic review

Acorns have traditionally been used in the human diet and for the treatment of specific diseases. Therefore, the present study performed a systematic review of studies which investigated the effects of Quercus spp. extracts in cancer prevention and treatment. A systematic literature search was performed for original records which addressed the anticancer effects of Quercus spp. extract in in vitro and in vivo cancer models. Body composition, food consumption, tumor development and/or toxicity were evaluated in in vivo studies, while cytotoxicity was evaluated in in vitro studies. Few studies and low sample sizes presented a challenge in the drawing of solid conclusions. Overall, the results suggested a positive impact of Quercus spp. extract, by reducing cancer development. Therefore, more studies with different cancer cell lines and animal models to address the efficacy of the acorn extracts in several types of cancer are required. Furthermore, the effects of acorn flour, incorporated in the diet, in an animal model of mammary cancer should be evaluated.info:eu-repo/semantics/publishedVersio

Prospective Serosurvey of Coxiella burnetii Antibodies in Selected Sheep of Portugal

Q fever is a zoonotic disease caused by Coxiella burnetii that is highly prevalent across the world. In this study, a prospective serosurvey was performed to study C. burnetii circulation in a population of sheep in the central region of Portugal. Blood from a representative sample of 168 animals was drawn in both 2015 and 2016, and sera were tested for IgG anti-C. burnetii by EIA. In 2015, 7.7% (13/168) animals tested positive for IgG anti-C. burnetii, while in 2016, 17.3% (29/168) tested positive, showing a statistically significant (P = 0.008) increase in anti-C. burnetii seroprevalence. Results support the notion that Q fever is emerging in central Portugal.N/

Outbreaks of abortions byCoxiella burnetiiin small ruminant flocks and a longitudinal serological approach on archived bulk tank milk suggest Q fever emergence in Central Portugal

Q fever is a worldwide zoonotic infectious disease caused by Coxiella burnetii and sheep and goats are known to be the main reservoir for human infection. This study describes the epidemiological and laboratory findings of C. burnetii outbreaks affecting sheep and goat flocks and also provides the results of a prospective serosurvey in bulk tank milk samples to assess C. burnetii circulation in a population of sheep living in close contact to the human population in Central Portugal. In the epizooties, C. burnetii was identified in tissues of the resulting abortions by qPCR. As for the serological survey, 10.2% (95%CI: 4.5‐19.2) of the 78 bulk tank milk samples collected in 2015 presented IgG antibodies against C. burnetii. The same farms were visited and sampled in 2016 and 25.6% (95%CI: 16.4‐36.8) were positive. This steep increase in the number of anti‐C. burnetii farms between the 2015 and 2016 collections showed to be statistically significant (p = 0.020) and is strongly suggestive of Q fever emergence in Central Portugal. Measures on animal health and on disease spread control to the human population should be considered.N/

Urinary bladder chemical carcinogenesis in laboratory rodents as an experimental model [Carcinogénesis química de vejiga urinaria en roedores de laboratorio como modelo experimental]

Urotelial cancer, is a common malignancy in the worldwide, is an important contributor to the overall international cancer burden. The urotelial tumors induced by chemical carcinogens in the laboratory animals repeat many of the features observed in the human urotelial neoplasia. The urotelial tumors chemically induced in the urinary bladder are morphologically and histologically similar to the human urotelial tumors. Like human urotelial carcinogenesis, rodent carcinogenesis is a multistep process that involves sequential progression from simple hyperplasia to invasive carcinoma or papillary tumors through varying lesions. In addition, the rodent tumors (Rattus norvegicus) and (Mus musculus) express several biochemical and molecular markers that are also expressed in the human urotelial tumors. For this reason, the rodent urinary bladder carcinogenesis is a good animal system to evaluate chemo preventive agents and to study cancer pathways

Altered expression of CKs 14/20 is an early event in a rat model of multistep bladder carcinogenesis

Cytokeratins (CKs) 14 and 20 are promising markers for diagnosing urothelial lesions and for studying their prognosis and histogenesis. This work aimed to study the immunohistochemical staining patterns of CK14/20 during multistep carcinogenesis leading to papillary bladder cancer in a rat model. Thirty female Fischer 344 rats were divided into three groups: group 1 (control); group 2, which received N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) for 20 weeks plus 1 week without treatment; and group 3, which received BBN for 20 weeks plus 8 weeks without treatment. Bladder lesions were classified histologically. CK14 and CK20 immunostaining was assessed according to its distribution and intensity. In control animals, 0-25% of basal cells and umbrella cells stained positive for CK14 and CK20 respectively. On groups 2 and 3, nodular hyperplastic lesions showed normal CK20 and moderately increased CK14 staining (26-50% of cells). Dysplasia, squamous metaplasia, papilloma, papillary tumours of low malignant potential and low- and high-grade papillary carcinomas showed increased CK14 and CK20 immunostaining in all epithelial layers. Altered CK14 and CK20 expression is an early event in urothelial carcinogenesis and is present in a wide spectrum of urothelial superficial neoplastic and preneoplastic lesions