Lymphocytic hypophysitis in dogs infected with Leishmania spp.

Background: Morphological involvement of endocrine glands, such as the pituitary gland, remain uninvestigated in dogs with canine visceral leishmaniasis. Therefore, this study investigated the presence of amastigotes of Leishmania spp. and characterized inflammatory changes, highlighting the involvement of TCD3+ lymphocytes in different regions of the pituitary gland of dogs. Methods: Samples were collected from 21 naturally infected dogs and 5 control, uninfected dogs. The different pituitary regions were analyzed in histological sections stained with hematoxylin and eosin (HE) under light microscopy. Inflammation was classified by intensity in a score from 0 to 3, absent (0), mild (1), moderate (2), and marked (3). The immunohistochemical (IHC) evaluation was performed in five high-power fields (hot spot) in a 40x objective of each region with manual counting (Image J1.52ª) of the TCD3+ lymphocytes and for amastigotes analyzed in 40x and 100x objectives. The Shapiro-Wilk test was used to assess the normality of the data. Differences between groups were determined by the Mann Whitney test. The correlation between variables was assessed by Sperman's correlation test. p < 0.05 were considered statistically significant. Results: Amastigotes from the pituitary glands of two infected dogs were identified using IHC. The histopathological evaluation stained with hematoxylin and eosin showed greater intensity of inflammation in the pars distalis and pars intermedia regions of infected dogs. IHC for TCD3+ lymphocytes showed a higher median number of immunolabeled cells in pars nervosa in the infected group than in the control group (p < 0.05); and expecting a variation in the distribution and number of these cells in naturally infected dogs, the median of the control group was considered a cut-off point, an increase in T lymphocytes (p < 0.05) was also observed in the pars intermedia and pars distalis of an infected subgroup (n = 10). A moderate significant correlation between the intensity of inflammation and the number of immunolabeled TCD3+ lymphocytes was established in the analyzed pituitary regions, characterizing the occurrence of hypophysitis. Conclusion: These findings presuppose that inflammation and/or the parasite in the pituitary region can result in gland dysfunction, worsening the clinical condition of the patient and compromising the efficiency of treatment and prognosis.

Microvessel density assessment in canine mammary carcinomas as a predictive factor for metronomic chemotherapy / Mensuração da densidade microvascular em carcinomas mamários caninos como fator preditivo à quimioterapia metronômica

The canine mammary tumor is the neoplasia that most commonly affects intact female dogs (not spayed) in routine veterinary practice. Canine mammary tumor therapy is a challenge because only few effective treatments have been described for high-grade tumors in veterinary medicine. One such therapeutic option that slows down tumor growth is metronomic chemotherapy (MC), a therapeutic modality that acts by decreasing tumor angiogenesis. Quantification of intratumoral microvessel density (MVD) has been proposed as a means to evaluate the effectiveness of MC in human and canine tumors. In this study, MVD is proposed as a predictive factor for the effectiveness of MC in canine mammary tumors. Twenty female dogs with mammary carcinoma were equally distributed into a mastectomy group treated only with mastectomy, and a MC group treated with MC (cyclophosphamide and piroxicam) orally and daily for 28 days followed by mastectomy. Mammary tumors were classified and graded histologically. MVD was ascertained by CD31 immunostaining. The analysis showed statistically significant difference in MVD scores between groups, corroborating a quantitative reduction in tumor microvasculature in the group treated with MC. Our findings suggest that MVD may be an important predictive factor for the selection of female dogs with malignant mammary tumors that may benefit from MC.

O tumor mamário canino é a neoplasia que mais comumente acomete cadelas não castradas na rotina veterinária. A terapia para a neoplasia mamária canina é um desafio, com poucos tratamentos eficazes descritos em medicina veterinária, especialmente para as neoplasias de alto grau. Uma opção terapêutica que diminui o crescimento tumoral é a quimioterapia metronômica (QM). A QM é uma modalidade terapêutica que age pelo decréscimo da angiogênese tumoral. Para avaliação da eficácia da QM tem sido proposta a quantificação da densidade microvascular (DMV) em neoplasias caninas. Neste estudo foi proposta a mensuração da DMV como fator preditivo à utilização da QM em neoplasias mamárias caninas. Foram utilizadas 20 (vinte) cadelas com carcinomas mamários malignos sendo um grupo mastectomia, tratado somente por mastectomia, e um grupo QM, em que foi empregada a QM (ciclofosfamida e piroxicam) ambos oralmente e de uso diário por 28 dias seguida de mastectomia. As neoplasias mamárias foram histologicamente classificadas e graduadas. A DMV foi obtida por imunomarcação utilizando o anticorpo CD31. A análise estatística mostrou diferença na DMV entre os grupos, evidenciando redução quantitativa na microvasculatura tumoral no grupo tratado com quimioterapia metronômica. Com base neste resultado é possível afirmar que a DMV pode vir a ser um fator preditivo de importância para a seleção de cadelas portadoras de neoplasia mamária maligna que possam vir a se beneficiar da quimioterapia metronômica.

Microvessel density assessment in canine mammary carcinomas as a predictive factor for metronomic chemotherapy / Mensuração da densidade microvascular em carcinomas mamários caninos como fator preditivo à quimioterapia metronômica

The canine mammary tumor is the neoplasia that most commonly affects intact female dogs (not spayed) in routine veterinary practice. Canine mammary tumor therapy is a challenge because only few effective treatments have been described for high-grade tumors in veterinary medicine. One such therapeutic option that slows down tumor growth is metronomic chemotherapy (MC), a therapeutic modality that acts by decreasing tumor angiogenesis. Quantification of intratumoral microvessel density (MVD) has been proposed as a means to evaluate the effectiveness of MC in human and canine tumors. In this study, MVD is proposed as a predictive factor for the effectiveness of MC in canine mammary tumors. Twenty female dogs with mammary carcinoma were equally distributed into a mastectomy group treated only with mastectomy, and a MC group treated with MC (cyclophosphamide and piroxicam) orally and daily for 28 days followed by mastectomy. Mammary tumors were classified and graded histologically. MVD was ascertained by CD31 immunostaining. The analysis showed statistically significant difference in MVD scores between groups, corroborating a quantitative reduction in tumor microvasculature in the group treated with MC. Our findings suggest that MVD may be an important predictive factor for the selection of female dogs with malignant mammary tumors that may benefit from MC.(AU)

O tumor mamário canino é a neoplasia que mais comumente acomete cadelas não castradas na rotina veterinária. A terapia para a neoplasia mamária canina é um desafio, com poucos tratamentos eficazes descritos em medicina veterinária, especialmente para as neoplasias de alto grau. Uma opção terapêutica que diminui o crescimento tumoral é a quimioterapia metronômica (QM). A QM é uma modalidade terapêutica que age pelo decréscimo da angiogênese tumoral. Para avaliação da eficácia da QM tem sido proposta a quantificação da densidade microvascular (DMV) em neoplasias caninas. Neste estudo foi proposta a mensuração da DMV como fator preditivo à utilização da QM em neoplasias mamárias caninas. Foram utilizadas 20 (vinte) cadelas com carcinomas mamários malignos sendo um grupo mastectomia, tratado somente por mastectomia, e um grupo QM, em que foi empregada a QM (ciclofosfamida e piroxicam) ambos oralmente e de uso diário por 28 dias seguida de mastectomia. As neoplasias mamárias foram histologicamente classificadas e graduadas. A DMV foi obtida por imunomarcação utilizando o anticorpo CD31. A análise estatística mostrou diferença na DMV entre os grupos, evidenciando redução quantitativa na microvasculatura tumoral no grupo tratado com quimioterapia metronômica. Com base neste resultado é possível afirmar que a DMV pode vir a ser um fator preditivo de importância para a seleção de cadelas portadoras de neoplasia mamária maligna que possam vir a se beneficiar da quimioterapia metronômica.(AU)