Original Full Paper
Compensatory kidney hypertrophy/hyperplasia leads to several changes in kidney structure and function, as increased glomeruli filtration. The aim of this study was to evaluate connexin 43 in remnant mouse kidneys after unilateral nephrectomy. The right kidney was surgically removed from BALB/c mice. Groups were euthanized at 24, 48 and 72 hours, and at 7 and 30 days. Kidney sections of the reminiscent kidneys were stained with Periodic Acid/Schiff and additional slides were submitted to BrdU and Cx43 immunohistochemistry. The results demonstrated an increase in kidney weight as early as 24 hours through 30 post-nephrectomy. In addition, BrdU positive epithelial cells increased at 24 and 48 hours post-nephrectomy. Cx43 was detected in the cytoplasm and membrane of epithelial cells and vasculature. Taking into consideration the quantity, intensity and localization of Cx43 immunostaining pattern, we observed that nephrectomized mice presented lower Cx43 expression and a cytoplasmic localization after 24 hours, peaking in 48 hours. Furthermore, western blot revealed that during the first 24 and 48 hours after nephrectomy, P0 (unphosphorylated) and P1 (phosphorylated) Cx43 disappeared, and the products of Cx43 degradation were reduced. On the other hand, after 72 hours the P0 and P1 state reappeared and the amount of degraded peptides also increased. Seven and thirty days after nephrectomy, a higher intensity of P0 and P1 state and a lower P2 (hyperphosphorylated) band were observed. In conclusion, our results suggest that Cx43 phosphorylation results in the retention of Cx43 in cytoplasm and its increased degradation during compensatory renal hyperplasia/hypertrophy.
Keywords: kidney, nephrectomy, hyperplasia/hypertrophy, connexin, gap junction
Canine visceral leishmaniasis is an endemic disease in Latin America caused by Leishmania (Leishmania) chagasi and transmitted to man and animals by infected blood-sucking sandflies) of the genus Lutzomyia. Dogs are considered to be the primary domestic reservoir of disease because they present an intense cutaneous parasitism. The aim of this study was to evaluate the intensity of the inflammatory process and to compare it to the parasite load of tissue from two different sites of the ear skin of dogs naturally infected with Leishmania chagasi. We think that exist a specific anatomical region that exhibits a relatively higher rate of parasitism. For diagnostic analysis, serological tests were carried out using the indirect fluorescence antibody test (IFAT) and the enzyme-linked immunosorbent assay (ELISA). Twelve animals naturally infected with Leishmania chagasi were euthanatized with a lethal dose of Sodium Thiopental™ and T61™. During the necropsy, fragments of the extremity and middle&61481; anatomical regions of the ear were collected. All tissues were fixed in a 10% formalin solution and then paraffin-embedded for histopathological (HE) and immunohistochemical analysis. The streptoavidin-peroxidase immunohistochemistry method was used to detect tissue amastigotes using optical microscopy. Our results indicated a chronic inflammatory reaction, ranging from discrete to an intense magnitude. The inflammatory process was more frequently observed in the extremity of the ear than in the middle portion of the ear (p<0.05). The presence of parasites in the ear extremity was higher than in other evaluated regions. A positive correlation between the tissue inflammation, parasitism, and serological data was confirmed at both ear positions (p<0.05). Skin biopsies are an important tool for CVL diagnosis and the ear extremity represents an appropriated area to perform the assays.
Keywords: Leishmania chagasi, dogs, skin biopsies, diagnosis, ear extremity, ear middle.
Inflammatory mammary carcinoma (IMC) is a unique form of mammary cancer that affects women and female dogs. Hallmarks of IMC include clinical signs of inflammed affected glands and invasion of dermal lymphatics by tumor cells. Due to locally aggressive behavior and high metastatic rate, prognosis is considered poor. No satisfactory treatment has been suggested in veterinary medicine. The goal of this study was to evaluate the immunoreactivity for estrogen and progesterone receptors and cell proliferative indexes in nine cases of canine IMC. Estrogen and progesterone receptors were negative in all cases. For cell proliferative indexes, the mean number of neoplastic cells staining positive for Ki-67 and PCNA were 4.47% and 20.81%, respectively. Lack of estrogen and progesterone receptor expression, suggesting an undifferentiated phenotype, in conjunction with a relatively high proliferative capacity reflected by Ki-67 and PCNA staining are features typical of many clinically aggressive neoplasms, including canine IMC.
Keywords: Dog, inflammatory mammary carcinoma, estrogen receptors, progesterone receptors, proliferative indices.
Multiple myeloma is an uncommon malignant neoplastic disease of humans and domestic animals associated with the excessive production of immunoglobulin by proliferated plasma cells. This article describes the findings associated with this disease entity in a 12-yr-old female Boxer dog. Clinically, the dog was very thin and had polyuria, polydypsia, and motor incoordination. Laboratory examinations revealed hypergammaglobulinemia, hypercalcemia, leucopenia, anemia, and thrombocytopenia. Radiographical evidences of osteolytic bone lesions were observed in various regions of the vertebrate column. Multiple myeloma was initially diagnosed by cytology from a fine needle bone marrow aspirate. Gross lesions suggestive of multiple myeloma were observed in the marrow of long bones, with associated widespread lymph node enlargement, splenomegaly, and hepatomegaly. Histopathology confirmed multiple myeloma in the bone marrow with metastases to the liver, lymph nodes, and spleen.
Keywords: dog; multiple myeloma; hypergammaglobulinemia; pathology.
This report describes a case of insulin-secreting pancreatic beta cell carcinoma in a crab-eating fox (Cerdocyon thous). The animal died approximately 60 days after the first clinical signs. At necropsy, a nodule (2 x 3 cm) was observed in the pancreas. Microscopic features were consistent with a pancreatic islet cell carcinoma. By immunohistochemistry, neoplastic cells were strongly positive for insulin and synaptophysin while negative for glucagon. These results supported the diagnosis of insulinoma, which to the best of our knowledge is the first documented case of this tumor in a crab-eating fox.
Keywords: Cerdocyon thous, crab-eating fox, insulinoma.
Avian mycobacteriosis was diagnosed in a captive scarlet macaw (Ara macao) that presented multifocal granulomas on subcutaneous tissue, sciatic nerves, infraorbital sinus, trachea, air sacs, muscles, spleen and liver. Microscopically, central areas of caseous necrosis surrounded by epithelioid macrophage, multinucleated giant cells, and lymphocytes were observed. Acid-fast bacilli were demonstrated by Ziehl-Neelsen stain. Inoculation into Löwenstein– Jensen, Stonebrink and Petragnani media, yielded Mycobacterium spp, which was identified as Mycobacterium avium by polymerase chain reaction technique (PCR).
Keywords: Ara macao, Mycobacterium avium.
A crossbred 14-year-old castrated male cat had a history of lethargy, anorexia and weight loss of one month evolution. On clinical examination, anemia, emaciation, jaundice and a large mass in the abdomen were detected. Ultrasonography revealed hepatomegaly and a single splenic mass. The cat was submitted to biopsy and euthanatized during the surgical procedure. The diagnosis of malignant histiocytosis was achieved on the basis of the clinical presentation, histopathologic and immunoistochemical findings.
Keywords: Malignant histiocytosis, histiocytic diseases, neoplasia, pathology, diseases of cats
Gap junctions are sites on the cellular membrane with intercellular channels build up by twelve protein subunits called connexins. Each connected cell contributes with a hemichannel made up by six connexins subunits. This kind of connection represents and efficient way of intercellular communication in most tissues, including the nervous system. It works as a passage for ions, secondary messenger and metabolites exchange between the cells. In a complex tissue like the nervous tissue they are particularly important because they connect the various cellular types composing a panglial syncytium that performs neuronal protection and tissue homeostasis. The expression of connexins and the intercellular communication through gap junctions are crucial to regulate vital functions as cellular motility, proliferations and survival; changes in the conformational expression of connexins may be involved in diseases as Alzheimer´s disease, neoplasms, bacterial and parasitic infections,even affect cellular groups when they occur as genetic mutations leading to functional defects of the nervous system as demyelination in the PNS (Charcot-Marie-Tooth disease), hereditary epilepsy, nonsyndromic deafness and senile cataract.
Keywords: gap junctions, connexins, diseases of the nervous system