Presença da mutação do gene BRCA1 em cadelas com tumores mamários malignos / Presence of BRCA1 gene mutation in bitches with malignant mammary tumors

Mammary tumors (MTs) in bitches are similar to breast cancers in women. Thus, they can be used as a model for human breast cancer and findings can be extrapolated for use in human medicine. BRCA1 is a tumor suppressor gene. When the gene has a mutation, it cannot repair damaged DNA, which causes genetic instability and tumorigenesis. Therefore, we aimed to study the frequency of single nucleotide polymorphisms (SNPs) in the BRCA1 gene that are associated with distinct histological types of malignant MT in bitches. The study population consisted of 91 bitches, including a control group of 6 animals with healthy mammary glands and 85 animals with MTs. All animals underwent a presurgery evaluation consisting of a questionnaire administered to the person responsible for the animal, a physical examination, collection of peripheral blood for hematological and serum biochemistry evaluations, an electrocardiogram, and a preanesthesia evaluation. In addition, distant metastasis was studied via chest radiography and abdominal ultrasound. After evaluations were complete, the animals that could undergo surgery were administered general anesthesia and underwent a mastectomy or mammary gland sample collection. Histopathological examination and molecular analysis were performed to identify mutations in the BRCA1 gene. Histopathological examinations found 10 different types of malignant tumors in 36 sick animals. Tumor samples plus samples from the 6 control animals were subjected to DNA extraction, polymerase chain reaction (PCR) analysis, and genetic sequencing. The tumor with the highest incidence (33.33%) was a complex carcinoma, followed by carcinoma in mixed tumor (13.88), tubular carcinoma (13.88) and carcinosarcoma (13.88). Molecular analysis revealed 3 different SNP points in 5 samples (4006G>A, 3619A>G, and 3761C>T). The allelic variant 4006G>A (1/36) resulted in the alteration of the amino acid valine by isoleucine (V1336 I). The mutation 3619A>G (2/36) inserted the amino acid alanine instead of threonine (T1207 A). The mutation 3761C>T (2/36) led to the alteration of the amino acid serine by phenylalanine (S1254 F), a mutation for which there are no published reports. The histological types that showed BRCA1 mutations were complex carcinoma (1/5), carcinoma in mixed tumor (1/5), papillary carcinoma (1/5) and tubular carcinoma (2/5). Software analysis identified the new SNP (nucleotide 3761) in BRCA1 and 2 point mutations in nucleotides 4006 and 3619 and responsible for genetic instability. The development of breast cancer is caused by many endogenous and exogenous factors. The results of our study show that these factors have a greater presence in female, mixed breed, uncastrated, and older dogs, confirming the data in the veterinary literature. In the present study, we found different histological types of malignant breast tumors with mutations in the BRCA1 gene, as other authors have reported. However, we also found the mutation 3761C>T, which, to the best of our knowledge, has not been reported in the literature. This shows the need for studies in veterinary medicine that assess mutations in the BRCA1 gene and the most common histological types. In conclusion, SNPs in the BRCA1 gene cause genetic instability, resulting in additional mutations that lead to the development of breast tumors. They are point mutations that affect transcription, resulting in truncated proteins. These proteins may have a loss of function, leading to carcinogenesis.(AU)

Effects of intracameral injection of epinephrine and 2% lidocaine on pupil diameter, intraocular pressure, and cardiovascular parameters in healthy cats.

OBJECTIVES: To investigate the effects of the intracameral injection of epinephrine and two doses of 2% lidocaine on pupil diameter (PD), intraocular pressure (IOP), heart rate (HR), and mean arterial pressure (MAP) in healthy cats. METHODS: Five treatment groups were formed (10 cats/each). Animals received 0.2 mL of epinephrine, 0.2 or 0.3 mL of 2% lidocaine, or 0.2 mL of BSS. Cats were anesthetized, and all solutions were injected intracamerally. PD, IOP, HR, and MAP were assessed at baseline, following anterior chamber paracentesis (T0), and at every 5 minutes, until anesthesia was terminated (T60). PD and IOP continued to be assessed for 2 additional hours during recovery from anesthesia. In another group, cats were not anesthetized and one of the eyes was treated with one drop of 0.5% tropicamide to check for maximal pupil diameter. RESULTS: Faster onset and longer duration of sufficient mydriasis (>10 mm) were observed in epinephrine treatment group, when comparing with cats treated with both doses of lidocaine. Eyes treated with epinephrine achieved the largest maximum pupil diameter (mm) when comparing with eyes treated with 0.3 mL of lidocaine (11.01 ± 0.16), tropicamide (10.66 ± 0.17), and 0.2 mL of lidocaine (10.23 ± 0.12) (P < .0001). In all groups, IOP decreased significantly at T0, but tended to return to baseline at T60. HR and MAP did not change significantly during time and among treatments. CONCLUSIONS: The intracameral injection of 0.2 mL of 1:100 000 epinephrine and 0.3 mL of 2% lidocaine can be used as an alternative to tropicamide in healthy cats. Both treatments produced satisfactory and long-lasting mydriasis without adverse effects on IOP, HR, and MAP.

Rural area of the Brazilian Pantanal wetlands associated with the occurrence of anti-Leishmania spp. antibodies in dogs / Área rural do Pantanal brasileiro associada à ocorrência de anticorpos anti-Leishmania spp. em cães

An evaluation was made of the presence of anti-Leishmania infantum chagasi antibodies in domestic dogs from the urban and rural areas of Brazil's Pantanal wetland region using serological techniques. A total of 429 dogs were sampled in three areas of the Pantanal biome, including the municipalities of Poconé, Santo Antônio de Leverger, and Barão de Melgaço, in the state of Mato Grosso, and in the municipality of Corumbá, in the state of Mato Grosso do Sul. The immunofluorescence assay (IFA) was used to detect antibodies (cut-off point 40) using Leishmania infantum chagasi antigen. Because of the possibility of cross-reactivity between species of the genus Leishmania, samples that were positive in the IFA against L. infantum chagasi were also tested by IFA in the same conditions, using L. amazonensis and L. braziliensis antigens. IFA-positive samples to L. infantum chagasi were also evaluated using Enzyme-Linked Immunosorbent Assay (ELISA). The results showed the presence of antibodies against L. infantum chagasi in 23 (5.36%; 95% CI: 3.50%-8.05%) dogs and at least one seroreactive dog was found in each of the municipalities evaluated in this study. Antibody titers ranged from 40 to 5,120, and all IFA positive samples were positive in the ELISA. Among the 23 positive dogs, nine were also were seroreactive for L. amazonensis and L. braziliensis antigens. The occurrence of anti- L. infantum chagasi antibodies in dogs was higher in rural areas (7.06%) than in urban areas (2.50%) (P < 0.05). Based on this study, we concluded that dogs from rural areas of the Pantanal wetlands were in contact with Leishmania species, which is relevant information given their importance to public health.(AU)

Neste trabalho foi realizada uma avaliação sobre a presença de anticorpos anti-Leishmania infantum chagasi em cães domésticos das áreas urbanas e rurais da região do Pantanal brasileiro usando técnicas sorológicas. Um total de 429 cães foram amostrados em três áreas do bioma do Pantanal, incluindo os municípios de Poconé, Santo Antônio de Leverger e Barão de Melgaço, em Mato Grosso, e o município de Corumbá, em Mato Grosso do Sul. A reação de imunofluorescência indireta (RIFI) foi utilizada para detectar anticorpos (ponto de corte de 40) de Leishmania infantum chagasi como antígeno. Devido à possibilidade de reação cruzada entre as espécies do gênero Leishmania, as amostras positivas na RIFI para L. infantum chagasi foram também avaliadas na RIFI utilizando L. amazonensis e L. braziliensis como antígenos. As amostras positivas na RIFI para L. infantum chagasi foram avaliadas utilizando o ensaio de imunoadsorção ligado à enzima (ELISA). Os resultados mostraram a presença de anticorpos contra L. infantum chagasi em 23 (5,36%; IC 95%: 3,50% -8,05%) cães e pelo menos um cão soro-reativo foi encontrado em todos os municípios avaliados neste estudo. Os títulos de anticorpos variaram de 40 a 5.120 e todas as amostras positivas na RIFI foram positivas no ELISA. Entre os 23 cães positivos, nove também reagiram para L. amazonensis e L. braziliensis. A ocorrência de anticorpos anti-L. infantum chagasi em cães foi maior nas áreas rurais (7,06%) do que nas áreas urbanas (2,50%) (P < 0,05). Com base neste estudo, concluímos que cães de áreas rurais do Pantanal tiveram contato com espécies de Leishmania, o que é uma informação relevante, dada a sua importância para a saúde pública.(AU)

Firocoxib on aqueous humor prostaglandin E 2 levels for controlling experimentally-induced breakdown of blood-aqueous barrier in healthy and Toxoplasma gondii -seropositive cats / Efeitos do firocoxib sobre os níveis de prostaglandina E 2 no humor aquoso de gatos saudáveis e com sorologia positiva para toxoplasmose mediante quebra da barreira hematoaquosa experimentalmente induzida

ABSTRACT: This study aimed to evaluate the effects of firocoxib for controlling experimentally-induced breakdown of the blood-aqueous barrier in healthy and Toxoplasma gondii -seropositive cats. Thirty two cats with no ocular abnormalities were used. Groups (n=8/each) were formed with healthy cats that received 5mg g-1 of oral firocoxib (FH) or no treatment (CH) on day 0; seropositive cats for anti -T. gondii specific immunoglobulin G (IgG) were grouped (n=8/each) and treated in a similar fashion (FT and CT). On day 1, cats of all groups received the same treatment protocol, and 1h later, aqueocentesis was performed under general anesthesia (M0). Following 1h, the same procedure was repeated (M1). Quantitation of aqueous humor total protein and prostaglandin E2 (PGE2) were determined. Aqueous samples of seropositive cats were tested for anti- T. gondii specific IgG. In M0, aqueous samples of CT showed a significantly higher concentration of PGE2 in comparison with other groups (P<0.05). In all groups, PGE2 concentration increased significantly from M0 to M1 (P=0.001). PGE2 values did not change significantly between groups in M1 (P=0.17). Anti- T. gondii specific IgG were reported only in samples of M1, and aqueous titers did not change significantly between FT and CT (P=0.11). Although we have observed that aqueous humor PGE2 levels were significantly higher in cats of CT group during M0, such increase was not able to break the blood-aqueous barrier and cause anterior uveitis. Firocoxib did not prevent intraocular inflammation after aqueocentesis, in healthy and toxoplasmosis-seropositive cats.

RESUMO: Objetivou-se avaliar a eficácia do firocoxib no controle da quebra da barreira hematoaquosa experimentalmente induzida em gatos saudáveis e com sorologia positiva para toxoplasmose. Para tanto, utilizaram-se trinta e dois gatos sem alterações oculares, alocados em grupos (n=8/cada) compostos por gatos saudáveis que receberam tratamento prévio com 5mg g-1 de firocoxib oral (HF) ou sem nenhum tratamento (CH) no dia 0, e por gatos com sorologia positiva para toxoplasmose tratados de maneira similar (FT e CT). No dia 1, os gatos de todos os grupos receberam o mesmo protocolo de tratamento do dia anterior e, 1h depois, foram submetidos à paracentese da câmara anterior sob anestesia geral (M0). Após 1h, realizou-se nova paracentese (M1). Mediante a colheita de humor aquoso (M0 e M1), quantificaram-se os valores de proteína total e prostaglandina E2 (PGE2) das amostras. As amostras dos gatos com sorologia positiva para toxoplasmose foram também testadas para anticorpos anti- T. gondii IgG específicos. Em M0, as amostras de humor aquoso de CT apresentaram concentração de PGE2 significativamente superior aos demais grupos (P<0,05). Em todos os grupos, a concentração de PGE2 aumentou significativamente de M0 para M1 (P=0,001), no entanto, não houve diferença significativa entre os grupos em M1 (P=0,17). Anticorpos anti -T. gondii IgG específicos foram encontrados somente em amostras de M1, e os títulos não diferiram significativamente entre FT e CT (P=0,11). Valores de PGE2 significativamente superiores no CT durante M0 não foram capazes de induzir a quebra da barreira hematoaquosa e causar uveíte anterior nos gatos deste estudo. O firocoxib, por sua vez, não foi capaz de prevenir a quebra da barreira hematoaquosa após realização de paracente na câmara anterior em gatos saudáveis e com sorologia positiva para toxoplasmose.