Mutagenicity of a novel 2-phenylbenzotriazole (non-chlorinated 2-phenylbenzotriazole-9) in mice.

Dinitrophenylazo dyes can form 2-phenylbenzotriazoles (PBTAs) in the textile dyeing process upon the addition of chemical reducing agents. Some dinitrophenylazo dyes, as well as their respective reduced (non-chlorinated) and chlorinated PBTAs, are now found in rivers owing to wastewater from textile plants. This study aimed to investigate the genotoxicity of a new PBTA derived from C.I. Disperse Violet 93 azo dye, namely non-Cl PBTA-9. Primary DNA damage in the blood, liver, and colon cells, micronucleated cells in the bone marrow, and gene expression (NAT2, CYP1A1, TRP53, and CDKN1A) in liver cells were observed in mice, at acute oral exposure (gavage) doses of 5, 50, and 500 µg/kg body weight (b.w.). The non-chlorinated PBTA-9 caused DNA damage in the blood and liver (at 500 µg/kg b.w.) and in colon cells (at 5, 50, and 500 µg/kg), and increased the frequency of micronucleated cells in the bone marrow (at 5 and 50 µg/kg). No histological alterations or gene expression changes were observed. In conclusion, in vivo exposure to non-chlorinated PBTA-9 induced genetic damage in various rodent tissues, corroborating results previously obtained from the Ames test. Because this compound has been detected in rivers, exposure to humans and biota is a major concern.

Luteal vascularity and embryo dynamics in mares during early gestation: Effect of age and endometrial degeneration.

The present study characterized the luteal status and the dynamic of the conceptus during the first 20 days of gestation in mares with different ages and degrees of endometrial degeneration. Total area of the corpus luteum (CL), luteal vascularity, CL area with blood signals, progesterone concentrations (P4), embryonic vesicle diameter, number of embryonic location changes, embryonic fixation position and uterine contractility were evaluated. In Experiment 1, mares ≤6 years of age (Young group, 5.6 ± 0.2 years, n = 7 mares) and mares ≥15 years of age (Old group, 17.2 ± 0.9 years, n = 6 mares) were used to investigate the effect of age. In Experiment 2, the luteal and embryonic parameters were compared between mares with minimal (Mild group, endometrial category I, n = 9 mares) and severe (Severe group, endometrial category III, n = 7 mares) endometrial degeneration. The Old and Severe groups had greater (p ≤ 0.04) total CL area and reduced luteal vascularity (p ≤ 0.04) than the Young and Mild groups, respectively. However, P4 levels and CL area with blood signals were similar (p ≥ 0.8) between the groups. A negative effect of age (p < 0.01), but not of endometrial degeneration (p = 0.6), was found for the embryonic vesicle diameter. The conceptus mobility was high (p > 0.1) until day 14 of gestation in the Severe group, while a reduced number of changes of the embryo location was detected earlier (p < 0.05) in the Old group. In conclusion, the newly formed CL of aged mares and mares with severe endometrial degeneration suffered a structural remodelling to safeguard the local blood supply and the continuous P4 output during early gestation. Moreover, an earlier reduction of the embryonic mobility and a delayed development of the conceptus were associated with advanced age, regardless of the degree of endometrial degeneration.

Canine transmissible venereal tumor: expression of MDR-1, and TP53 and BCL-2 family genes and its implications in biological and therapeutic behavior / Tumor venéreo transmissível canino/: expressão dos genes MDR-1, TP53 e da família Bcl-2 e suas implicações no comportamento biológico e terapêutico / Tumor venéreo transmisible canino: expresión de los genes MDR-1, TP53 y de la familia Bcl-2 y sus implicaciones en el comportamiento biológico y terapéutico

Transmissible venereal tumor (TVT) is a neoplasm of round cells with plasmocytoid or lymphocytoid appearance. The tumor presents several particularities, which have been the subject of numerous studies; however there still have investigations that need to be done. For example, a progressive increase of highly aggressive tumors with varying response to chemotherapy -including resistance- has been evidenced in recent years. There is scientific interest to understand these differences, allowing predicting possible clinical outcomes in affected dogs and increasingly searching adequate and individualized therapy. This review focuses on presenting possible implications of the expression of MDR-1 (P-glycoprotein), TP53, BCL-2, and BAX genes, regarding resistance to chemotherapy and/or the biologic behavior of TVT.

O tumor venéreo transmissível (TVT) é uma neoplasia de células redondas de aspecto plasmocitóide ou linfocitóide. O tumor apresenta várias particularidades que tem sido objeto de numerosas investigações e apesar disso, ainda existem lacunas que necessitam de maiores estudos. Por exemplo, nos últimos anos, tem-se evidenciado um aumento progressivo de tumores que apresentam elevados porcentuais de agressividade e variável resposta à quimioterapia, inclusive resistência. Desta forma, atualmente há interesses científicos com relação a compreender melhor estas diferenças, permitindo predizer uma possível evolução clínica entre cães acometidos pelo tumor e buscando cada vez mais uma conduta terapêutica adequada e individualizada. Assim, a revisão de literatura, centra-se em apresentar possíveis implicações da expressão dos genes MDR-1 (glicoproteína-p), TP53, BCL-2, BAX, quanto à resistência à quimioterapia, e/ou comportamento biológico do TVT.

El tumor venéreo transmisible (TVT) es una neoplasia de células redondas de aspecto plasmocitoide o linfocitoide. El tumor presenta varias particularidades que han sido objeto de numerosas investigaciones y a pesar de eso, aún existen algunos vacíos en su conocimiento que requieren mayores estudios. Por ejemplo, en los últimos años, se ha evidenciado un aumento progresivo de tumores que presentan elevados porcentajes de agresividad y una respuesta variable a la quimioterapia, inclusive alguna resistencia. En este sentido, actualmente hay intereses científicos con relación a comprender mejor estas diferencias, permitiendo predecir una posible evolución clínica entre perros afectados por el tumor y buscando cada vez más una conducta terapéutica adecuada e individualizada. Así, la revisión de literatura, se centra en presentar posibles implicaciones de la expresión de los genes MDR-1 (glicoproteína-p), TP53, BCL-2, BAX, en cuanto a la resistencia a la quimioterapia, y/o el comportamiento biológico del TVT.

A deteccao de substancias cancerígenas em bioensaios alternativos de média-duracao / The detection of chemical carcinogen in alternative medium-term biossays

Atualmente, o método standard para identificacao de substancias cancerígenas é teste de longa-duracao, con roedores. No Brasil nao há condicoes para a sua execucao, devido á inexistencia de especialistas e de infra-estructura adecuada. En consequencia, o país é dependente dos conhecimentos gerados no exterior sobre o risco que determinados compostos químicos impoem ás populacoes e ao meio ambiente. Além disto, as desvantagens operacionais de teste delonga-duiracao levaram ao desenvolvimento de bioensaios alternativos, mais convenientes. O Instituto Brasileiro de Meio Ambiente(IBAMA) adotou oficialmente o bioensaio de média-duracao para múltiplos orgaos, no rato, como fonte de evidencia do potencial cancerígeno de agentes químicos. Con isto, procura atender a demanda de substancias que precisam ser testadas no país, antes de colocadas no mercado e, ao mesmo tempo, aum,entar o know-how nacional em carcinogénese química e avaliacao de risco cancerígeno