A preliminary evaluation of the circulating leptin/adiponectin ratio in dogs with pituitary-dependent hyperadrenocorticism and concurrent diabetes mellitus

Leptin and adiponectin are thought to modulate insulin sensitivity and pancreatic β-cell function, but there is limited information regarding the adipokine status of hyperglycemic dogs with hyperadrenocorticism. This study aimed to determine whether alterations in the leptin/adiponectin ratio, insulin sensitivity, and/or pancreatic β-cell function are associated with diabetes mellitus (DM) in dogs with pituitary-dependent hyperadrenocorticism (PDH). A total of 48 client-owned dogs were included in this prospective observational study: 20 dogs with PDH (10 normoglycemic and 10 with DM), 15 dogs with DM, and 13 healthy dogs. The serum concentrations of leptin, adiponectin, resistin, interleukin (IL)-1β, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF)-α were measured, and homeostatic model assessment indices (HOMAs) were calculated and compared among the groups. Serum leptin was significantly higher in PDH dogs with and without DM than in healthy and DM dogs, and it was lower in DM dogs than in PDH dogs without DM. Serum adiponectin was significantly lower in PDH dogs with DM than in healthy and PDH dogs, and it was significantly lower in DM dogs than in healthy dogs. Serum IL-10 was significantly higher in PDH dogs with DM than in healthy and PDH dogs without DM. The leptin/adiponectin ratio was significantly higher in PDH dogs with DM than in normoglycemic PDH dogs. Serum IL-6 concentrations were significantly higher in DM dogs than in healthy dogs. Serum IL-1β concentration was significantly higher in DM dogs than in healthy dogs and PDH dogs with DM and without DM. Serum TNF-α and IL-18 concentrations were not different among groups. The HOMA_{β-cell function} was significantly lower in PDH dogs with DM than in normoglycemic PDH dogs, while HOMA_{insulin sensitivity} was significantly lower in PDH dogs with DM than in healthy dogs. These results suggest that adipokine dysregulation, a reduction in insulin sensitivity, and a further impairment in pancreatic β-cell function might predispose PDH dogs to DM. Further longitudinal study will be necessary to confirm this result.

Cellular Characterization of Multidrug Resistance P-glycoprotein, Alpha Fetoprotein, and Neovascular Endothelium-Associated Antigens in Canine Hepatocellular Carcinoma and Cirrhotic Liver

P-glycoprotein (P-gp), which is encoded by the multidrug resistance gene (MDR-1); alpha fetoprotein (AFP); and vascular endothelium-associated antigens are well-known markers for human and canine hepatic diseases. We obtained liver tissues from 5 dogs with hepatocellular carcinoma (HCC) and 12 dogs with cirrhosis, and we performed histopathologic and immunohistochemical evaluations using anti-P-gp, anti-AFP, anti-CD31, and anti-CD34 antibodies. P-gp was expressed at higher levels in HCC than in cirrhotic livers ( P < .01), and was most commonly localized in biliary canaliculi and small ductuli. AFP was localized mainly in the cytoplasm in HCC ( P < .01) and in a few cases of cirrhosis. In both HCC and cirrhosis, the AFP-positive cells were morphologically similar to normal hepatocytes and showed an even cytoplasmic distribution of AFP. The endothelial markers CD31 and CD34 were used to investigate vascular distribution. CD31 was expressed strongly in the portal area and parenchyma in HCC, but it was rarely observed in the parenchyma in cirrhosis. CD34 expression could not be detected in both HCC and cirrhosis. This study constitutes the first comprehensive study of P-gp, AFP, and endothelial markers in canine HCC and cirrhosis. The importance of these markers in HCC and cirrhosis in dogs was demonstrated and provides a more accurate basis for a definitive diagnosis of HCC and cirrhosis in dogs.

Pulmonary lymphomatoid granulomatosis in a dog: evidence of immunophenotypic diversity and relationship to human pulmonary lymphomatoid granulomatosis and pulmonary Hodgkin's disease

We describe a 10-month-old, intact female American Cocker Spaniel with pulmonary lymphomatoid granulomatosis (PLG). On clinical examination, this dog presented with nonproductive dry cough, serous nasal discharge, dyspnea, and lack of appetite. Radiography showed a consolidated lesion in the left cranial lung lobe. Histopathologic examination showed a mixed population of atypical lymphoid cells that had infiltrated into the pulmonary blood vessels angiocentrically. The lymphocytes were CD3 positive, consistent with a pan-T-cell phenotype. The lymphoid cells in the lesion were also positive for CD20cy and CD79a, indicative of the presence of B cells. We also observed large Reed-Sternberg-like cells that were positive for CD15 and CD30, similar to observations in human pulmonary Hodgkin's disease (PHD). In conclusion, canine PLG in this Cocker Spaniel was associated with B and T cells, which is first identified in a case of canine PLG. It was histopathologically similar to human lymphomatoid granulomatosis and immunophenotypically similar to human PHD.

Stereochemistry of the proton elimination in the formation of (+)- and (-)-alpha-pinene by monoterpene cyclases from sage (Salvia officinalis)

The three pinene synthases (cyclases) from common sage (Salvia officinalis) catalyze the conversion of geranyl pyrophosphate to the bicyclic olefins (+)-alpha-pinene and (+)-camphene (cyclase I), (-)-alpha-pinene, (-)-beta-pinene, and (-)-camphene (cyclase II), and (+)-alpha-pinene and (+)-beta-pinene (cyclase III), in addition to smaller amounts of monocyclic and acyclic monoterpene olefins. (1R)-4-2H1- and (1S)-4-2H1-labeled geranyl pyrophosphates were prepared and used to examine the stereochemistry of the C3-proton elimination from the pinyl cation intermediates in the formation of the alpha-pinene enantiomers. Mass spectrometric analysis of the biosynthetic products derived from the chirally deuterated substrates revealed that cyclase I and cyclase III removed the C4-proR-hydrogen of the substrate (C3 proton trans to the dimethyl bridge of the pinyl nucleus) with a stereoselectivity exceeding 94% in the formation of (+)-alpha-pinene. Similarly, cyclase II removed the C4-proS-hydrogen of the substrate (C3-trans proton of the corresponding pinyl cation) with a stereoselectivity exceeding 78% in the formation of (-)-alpha-pinene. The stereoselectivity of these C3-axial hydrogen eliminations is rationalized on the basis of a stereochemical model for the electrophilic isomerization-cyclization reaction sequence catalyzed by the pinene cyclases. The changes in the overall rates of olefin biosynthesis by these enzymes and in the product ratios resulting from deuterium substitution also permitted confirmation of isotopically sensitive branching in pinene biosynthesis and allowed the observation of primary kinetic isotope effects in isolation.