Proto-oncogene HER-2 in normal, dysplastic and tumorous feline mammary glands: an immunohistochemical and chromogenic in situ hybridization study

<p>Abstract</p> <p>Background</p> <p>Feline mammary carcinoma has been proposed as a natural model of highly aggressive, hormone-independent human breast cancer. To further explore the utility of the model by adding new similarities between the two diseases, we have analyzed the oncogene HER-2 status at both the protein and the gene levels.</p> <p>Methods</p> <p>Formalin-fixed, paraffin-embedded tissue samples from 30 invasive carcinomas, 7 benign lesions and two normal mammary glands were analyzed. Tumour features with prognostic value were recorded. The expression of protein HER-2 was analyzed by immunohistochemistry and the number of gene copies by means of DNA chromogenic <it>in situ </it>hybridization.</p> <p>Results</p> <p>Immunohistochemical HER-2 protein overexpression was found in 40% of feline mammary carcinomas, a percentage higher to that observed in human breast carcinoma. As in women, feline tumours with HER-2 protein overexpression had pathological features of high malignancy. However, amplification of HER-2 was detected in 16% of carcinomas with protein overexpression, a percentage much lower than that observed in their human counterpart.</p> <p>Conclusion</p> <p>Feline mammary carcinoma would be a suitable natural model of that subset of human breast carcinomas with HER-2 protein overexpression without gene amplification.</p

Seudomicetoma dermatofítico en un gato persa : aspectos clínicos, patológicos y evolutivos

En este trabajo presentamos los aspectos clínicos, anatomopatológicos y evolutivos de un caso de dermatitis piogranulomatosa múltiple causada por hongos del género Microsporum, también conocida como seudomicetoma dermatofítico, en un gato persa, no castrado, de un año de edad al comienzo de la enfermedad. Las lesiones se caracterizaron macroscópicamente por la formación de numerosos nódulos de diferentes tamaños, localizados en la cabeza y antebrazo derecho, extendiéndose posteriormente a zona dorso lateral del tronco. La evolución de estos nódulos, que se generalizaron en algo menos de un mes, era hacia la coalescencia y fistulización, con descarga de un material grumoso blanco-grisáceo. El estudio histopatológico reveló una dermatitis piogranulomatosa, supeficial y profunda, caracterizada por presentar en el centro de los granulomas agregados de hongos septados inmersos en una matriz acidófila. La extirpación quirúrgica de un gran número de nódulos proporcionó mejorías transitorias, aunque reaparecieron nuevas lesiones. En este trabajo se describe la evolución tras dos años de seguimiento clínico. Tras el tratamiento con griseofulvina no se detectan nuevas lesiones después de 6 meses de su aplicación y seguimiento.This paper reports the clinical and histopathological features of a case of pyogranulomatous dermatitis caused by Microsporum fungi, a condition also known as dermatophyte pseudomycetoma, in a eneyear-old Persian cat. Grossly apparent fistulized nodules of varying sizes displaying a granular discharge were localized on the head, back, elbow and tail. Microscopic analysis revealed a deep piogranulomatous dermatitis characterized by centrally-located clusters of fungi within an acidophilic matrix. In just under a month, nodules had beco me generalized. Partial surgical excision and non-specific treatment provided temporary improvement, but new lesions subsequentlyappeared

Primary central nervous system T-cell lymphoma mimicking meningoencephalomyelitis in a cat

A cat was presented with right head tilt and circling. The lack of expression of virus antigens did not support the postmortem diagnosis of encephalomyelitis pointing to a diffuse primary central nervous system T-cell lymphoma on the basis of CD3 and CD45R co-expression with absence of CD79a staining. = Résumé — Lymphome primaire de système nerveux central type T imitant méningo-encéphalomyélite chez un chat. Un chat est venu avec inclinaison de la tête à droite et circling. L’absence d’expression des antigènes du virus ne prend pas en charge le diagnositic post mortem e d’une encéphalomyélite pointant vers un lymphome primaire du système nerveux central type T diffus sur la base de CD3 et CD45R coexpression avec absence CD79a expression

lmmunohistochemical localization of prolactin in functioning and regressing corpus luteum of pituitary autotransplanted rats

In an attempt to shed light on the intimate mechanism by which prolactin (PRL) switches from supporting corpus luteum (CL) progesterone secretion (P) to promote structural regression of the CL, day 2 (metestrous) autopituitary transplanted (APTr) rats were used. In APTr rats the CL is under the only control of PRL since an almost complete absence of LH and FSH exist. The experimental group was given bromocriptine (CB-154: 0.4 mg/day) on days 12, 13 and 14 of the cycle and 0.25 ml of ethanol from day 15 to day 21. The control group was given CB-154 from day 12 to day 21. Rats were hemiovariectomized on day 12 to assess the morphological characteristics of the active CL. PRL and P were determined by RIA on days 12, 15 and 22. On day 12, both PRL and P levels were higher than 80ng/ml (luteotrophic action of PRL). On day 15, due to treatment with CB- 154, the levels of both hormones had fallen below 7 ng/ml (functional luteolysis). On day 22, PRL levels were again high ( > 50 ng/ml) in the shortly CB-154-treated rats and low ( < 5 ng/ml) in the controls; the P levels were lower than 5 ng/ml in both groups. PRL-induced structural luteolysis in the experimental group (hyperprolactinemic) was assessed by the structural characteristics and by the CL weight loss on day 22 in comparison with that exhibited by control rats. The immunohistochemical staining of both endogenous and total PRL in the lutein cells showed that the internalization of PRL is not modified by the functional state of the CL, nevertheless the intracellular redistribution of the internalized hormone varied in relation with the PRL action on the CL (luteotrophic, day 12vs luteolytic, day 22).These results seem to indicate that intracellular mechanisms rather than receptor content determine CL response to PRL

Short Paper : A Joint Myxoma in a Dog

Myxomas of the joints are extremely rare in domestic animals, only four cases, all in dogs, having been reported previously. This paper describes a myxoma originating from the synovium of the right radiocarpal joint of a mature female Dobermann pinscher with right front limb lameness. The tumour was excised surgically and no recurrence was detected during a 2-year follow-up period. Immunohistochemically, the tumour cells reacted with antibodies to vimentin and S100 protein but not with antibodies to cytokeratins (high and low molecular weight) or human callus keratin.Los mixomas articulares son extremadamente raros en los animales domésticos; sólo se han registrado cuatro casos, todos ellos en perros. En este artículo se describe un mixoma originado en la sinovia de la articulación radiocarpiana derecha de una hembra madura de de una hembra madura de Dobermann pinscher con cojera de la extremidad delantera derecha. El tumor fue extirpado quirúrgicamente y no se detectó ninguna recidiva durante un periodo de seguimiento de 2 años. Inmunohistoquímicamente, las células tumorales reaccionaron con anticuerpos contra la vimentina y la proteína S100, pero no con anticuerpos contra las citoqueratinas (de alto y bajo peso molecular) o a la queratina del callo humano.Universidad Nacional, Costa RicaEscuela de Medicina Veterinari

PLAQUETAS: CARACTERÍSTICAS ULTRAESTRUCTURALES Y SU PAPEL EN LA HEMOSTASIA Y RESPUESTA INFLAMATORIA

Platelets are the smallest elements in the blood where they circulate a anucleated cells derived from megakaryocytes. Platelets play a critical role in hemostasis . However, current research has revealed that platelets also participate in the inflammatory process and in body defense. Platelets may interact with neutrophils. monocytes and macrophages, endothelial cells, fibroblasts, microorganisms, and immunoglobulins. Because of great importance of these cells we want to do a review of platelets function .Las plaquetas son las célula más pequeñas de la sangre en la que circulan como elemento anucleados derivados de los megacariocitos. E tas célula juegan un papel muy importante en la hemostasis. Sin embargo, trabajos recientes han revelado que la plaquetas también participan en lo procesos inflamatorios y en la respuesta inmune. La plaquetas pueden interaccionar con los leucocitos polimorfonucleares neutrófilos, monocitos y macrófago , células endoteliaJes, fibroblastos, microorganismos, proteínas de fa e aguda, el sistema del complemento y las inmunoglobulina . Por su gran importancia pretendemos hacer una revisión actualizada de las funciones de las plaquetas