Quantitative demonstration of the existence of two isoforms of canine hepcidin in the serum & urine of dogs.

Hepcidin-25 is the key peptide hormone controlling vertebrate iron metabolism. However, in the last twenty years there was some disagreement in the literature over the structure of this compound. The aim of this research was to study whether more than one isoform of canine hepcidin-25 exists. For the purpose of comparison serum concentrations of hepcidin-25 were determined in the samples of 47 dogs sick with acute/chronic inflammation too. The study demonstrated that two isoforms of canine hepcidin-25 exist. A statistical correlation may indicate that both molecules are synthesised by dogs together. No statistically significant correlations were found between the measured concentrations of the two canine hepcidin-25 isoforms and the measured serum iron parameters in the sampled dogs, irrespective of the measurements were made in serum or urine. The mean urinary total hepcidin-25/creatinine ratio in healthy dogs was 1.08 ± 0.10. The mean serum total hepcidin-25 concentration was 79.8 ± 4.9 ng/ml, about 65% of which was the 25ß version. The presence of inflammation results in a statistically significant increase in the serum concentration of both hepcidin varieties. The role and fate of the two molecules may need to be researched further to provide better understanding of their relation.

Effects of p.o. administered xylitol in cats.

Xylitol is commonly used as sugar substitute in households. While it has numerous beneficial effects on human health, it is highly toxic to dogs. The goal of this study was to examine whether xylitol has similar deleterious effects, such as hypoglycaemia and acute hepatic failure, on cats. Our research included six healthy middle-aged cats. Xylitol was dissolved in deionized water and administered p.o. at three doses (100, 500 and 1,000 mg/kg body weight). These dosages have been considered toxic and can cause liver failure or even death in dogs. After every xylitol administration, the basic health status and the blood glucose of cats were observed regularly. Additionally, prior to and 6, 24 and 72 hr after xylitol administration, blood samples were taken to check complete blood count, clinical biochemical parameters and enzymes such as ALT, ALKP, GGT, GLDH, bile acids, BUN, creatinine, phosphate, total protein, albumin, sodium and potassium. There were no significant changes (p > .05) in any of the haematological or biochemical parameters. Blood glucose concentrations did not show any significant alterations, except at 1,000 mg/kg dose, where a mild but significant increase was observed, but it was in physiological range. Based on our results, xylitol did not induce toxic effects on cats.

Expression of claudin-1 in canine peripheral nerve sheath tumours and perivascular wall tumours. Immunohistochemical study.

AIMS: A peripheral nerve sheath tumour consists of neoplastic Schwann cells or perineurial cells, or a mixture of Schwann cells, perineurial cells and fibroblasts. The first aim of the present study was to characterise the expression of the claudin-1 tight junction protein in canine intact peripheral nerves, canine benign peripheral nerve sheath tumours (cBPNSTs), such as schwannomas, neurofibromas, perineuriomas and canine malignant peripheral nerve sheath tumours (cMPNSTs), and in different other benign and malignant canine spindle cell tumours. The second aim of the present study was to examine whether claudin-1 can help to distinguish the subgroups of canine perivascular wall tumours. METHODS AND RESULTS: The biopsy and necropsy samples (n=203) included 10 intact peripheral nerves, 20 cBPNSTs (4 schwannomas, 8 neurofibromas, 8 perineuriomas), 16 cMPNSTs, 6 psammomatous meningiomas, 6 dermatofibromas, 6 leiomyomas, 6 myxomas, 4 spindle cell hemangiomas, 2 spindle cell lipomas, 6 fibrohistiocytic nodules, 8 fibrosarcomas, 8 leiomyosarcomas, 6 myxosarcomas, 8 hemangiosarcomas, 8 anaplastic sarcomas, 8 amelanotic spindle cell melanomas, 8 histiocytic sarcomas, 8 spindle cell carcinomas, 8 myoepitheliomas, 8 complex carcinomas, 5 cardiac rhabdomyosarcomas, 4 synovial sarcomas, 5 osteosarcomas, 4 chondrosarcomas and 4 liposarcomas; 31 canine perivascular wall tumours: 10 hemangiopericytomas, 8 myopericytomas, 6 angioleiomyomas, 4 angioleiomyosarcomas, 3 angiofibromas. The immunohistochemical panel consisted of humanized antibodies: anti-claudin-1, anti-neuron specific enolase, anti-S-100 protein, anti-α-smooth muscle actin, anti-vimentin, anti-cytokeratin AE1-AE3, anti-claudin-5, anti-Melan-A and anti-heavy caldesmon, anti-calponin and anti-desmin. The intact perineurial cells, all perineuriomas, neurofibromas, cMPNSTs, spindle cell carcinomas and epithelial components of the complex carcinomas, all hemangiopericytomas and myo-pericytomas showed claudin-1 positivity. The schwannomas and other spindle shape cell tumours were negative for claudin-1. CONCLUSION: Our findings suggest that an antibody against claudin-1, in combination with other antibodies, can be used as a novel diagnostic tool to differentiate canine peripheral nerve sheath tumours from other fusocellular tumours, and anti-claudin-1, together with other antibodies, can also be used to subclassify cBPNSTs. Furthermore, analysis of claudin-1 expression can help to differentiate between subgroups of canine perivascular wall tumours.

Claudin-7 protein differentiates canine cholangiocarcinoma from hepatocellular carcinoma.

UNLABELLED: The aim of the present study was to characterise the expression pattern of claudin-7 tight junction protein in canine normal liver, hyperplastic and primary neoplastic lesions of the canine liver and whether this tight junction protein can help differentiate canine cholangiocarcinomas from canine hepatocellular carcinomas. METHODS AND RESULTS: Necropsy samples included 15 canine normal liver tissue samples, 10 hepatocellular nodular hyperplasias, 6 hepatocellular adenomas, 15 well-differentiated and 6 poorly differentiated hepatocellular carcinomas, 6 cholangiocellular hyperplasias, 10 cholangiocellular adenomas, 15 well-differentiated and 6 poorly differentiated cholangiocarcinomas, 6 normal extrahepatic bile ducts, 8 normal gall bladder tissue samples, and 5 cystic mucinous hyperplasias of the gall bladder. In all canine normal liver tissue samples the hepatocytes were negative for claudin-7 and the normal biliary epithelial cells showed intense basolateral membrane claudin-7 positivity. In all cholangiocellular hyperplasia samples and in all cholangiocellular adenoma samples the benign cholangiocytes showed intense basolateral membrane positivity for claudin-7. In all samples of the well-differentiated and poorly differentiated cholangiocarcinomas, the malignant neoplastic biliary epithelial cells showed intense basolateral membrane positivity for claudin-7. Neither the hyperplastic nodules of the liver cells nor the hepatocellular adenomas reacted with claudin-7. The well-differentiated and poorly differentiated hepatocellular cancers were negative for claudin-7. The epithelial cells of canine normal extrahepatic bile ducts, gall bladder and cystic mucinous hyperplasias of the gall bladder showed intense basolateral membrane positivity for claudin-7. Differences in the intensity of claudin-7 reaction were not apparent among different types of proliferative lesions of cholangiocytes or degrees of cellular differentiation of neoplastic biliary epithelial cells. CONCLUSION: Consequently, we hypothesize that claudin-7 is an excellent immunohistochemical marker of the cholangiocellular differentiation in canines and can be used to detect benign and malignant proliferative lesions of the canine biliary tract. It can also help to differentiate canine cholangiocarcinomas from hepatocellular carcinomas.

Chronic hepatitis in the dog--a review.

Chronic hepatitis is a heterogeneous group of inflammatory-necrotizing diseases of the liver. There is controversy in both human and veterinary medicine about the classification of chronic hepatitis and this is likely to remain until a classification based on aetiology rather than on morphology is introduced. Controversy exists as to whether chronic hepatitis in dogs is comparable to the human disorder. The aetiology of chronic hepatitis in dogs is poorly understood, whereas in humans an increasing number of viral causes have been found. Liver biopsy is essential for the diagnosis of chronic hepatitis both in dogs and in humans. Histopathological evaluation of the liver is required to make the diagnosis, which is based on the presence of liver cell necrosis and inflammatory reaction. The proposed criteria for the classification of hepatitis in dogs are then as follows: aetiology is the primary denominator (infectious, drug induced, autoimmune, or, if unknown, idiopathic). The other criteria are histopathological, with severity reflecting the severity of the necro-inflammatory activity (minimal, mild, moderate or severe) and chronicity reflecting the extent of fibrosis (none, mild, moderate, severe or cirrhosis).

Effects of lorglumide and atropine on MgSO(4)-induced gallbladder emptying in conscious dogs.

The aim of the study was to examine the possible involvement of cholecystokinin (by lorglumide) and cholinergic mechanisms (by atropine) in magnesium sulphate (MgSO(4))-induced gallbladder contraction of conscious dogs. The gallbladder (GB) volume was determined by ultrasonography. The optimal dose of 80 mg kg(-1)of MgSO(4)was determined from a MgSO(4)dose-response curve using doses of 10, 20,40, 80, 120 mg kg(-1). The largest dose of MgSO(4)was less effective than the optimal dose. Peak gallbladder contraction (32 per cent) was achieved at 30 minutes. Atropine (50 microg kg(-1)s.c.) or lorglumide (1 mg kg(-1)p.o.) fully prevented GB contraction. In conclusion, supraoptimal doses of MgSO(4)have a diminishing effect. The sustained contraction of the gallbladder in response to the optimal dose of MgSO(4)can be explained by an additive effect of the cholecystokinin release and a cholinergic trigger mechanism. Ultrasonography and MgSO(4)stimulation proved to be a valuable technique for examination of gallbladder motility.

Evaluation of ammonia measurements in dogs with two analysers for use in veterinary practice.

The measurement of ammonia in biological fluids is the only way to diagnose and evaluate hepatic encephalopathy, but samples for ammonia measurement cannot be stored or sent by post. Two analysers for use in veterinary practice have recently become available, the VetTest and the Blood Ammonia Checker II; the reliability of ammonia measurements in canine blood with these two analysers has been evaluated by comparing the results with a standard automated enzymatic assay. Blood samples from 39 dogs, with a range of ammonia concentrations from 5 to 589 microM, were used simultaneously in the three assays. The blood samples were placed immediately on ice, and the measurements were made in duplicate. The intra-assay coefficients of variation were 13.7 per cent for the VetTest, 4.7 per cent for the Blood Ammonia Checker, and 2.8 per cent for the enzymatic assay. The correlation coefficients over the entire range of concentrations were 0.79 between the VetTest and the enzymatic assay, and 0.98 between the Ammonia Checker and the enzymatic assay. The ammonia concentrations recorded in the enzymatic assay were divided into 12 samples within the normal range (0 to 50 microM), 18 samples with moderately increased concentrations (51 to 150 microM), and nine samples with concentrations above 150 microM. No correlation or a poor correlation was found between the results from the VetTest and those from the enzymatic assay from 0 to 50 microM (R = 0.27) and from 50 to 150 microM (R = 0.51; P = 0.05). The results from the VetTest were only reliable in samples with the highest concentrations (R = 0.93; P < 0.05). In contrast, the results from the Ammonia Checker correlated well with the results from the enzymatic assay over all the ranges: R = 0.79 (P < 0.05) from 0 to 50 microM, R = 0.86 (P < 0.05) from 50 to 150 microM, and R = 1.00 (P < 0.05) in samples exceeding 150 microM.

Fast resolution of hypercortisolism in dogs with portosystemic encephalopathy after surgical shunt closure.

The aim of this study was to investigate whether hypercortisolism in dogs with congenital portosystemic shunts disappeared after surgical closure of the shunts concomitantly with recovery from hepatic encephalopathy. We examined 22 dogs before and four weeks after partial surgical closure of a single, large congenital portosystemic shunt (PSS). Parameters measured to characterise the basal activity of the pituitary-adrenal axis were the cortisol:creatinine (c/c) ratio in home-sampled urine and total and free cortisol in plasma. The binding characteristics of cortisol binding globulin (CBG) in pooled pre- and postoperative plasma were also determined. Ammonia and bile acid concentrations were measured in plasma to characterise the liver perfusion and function. Clinical symptoms relevant to liver function, cortisol excess, and hepatic encephalopathy were recorded semiquantitatively using a standardized questionnaire. The dogs had hypercortisolism before surgery, which had normalized four weeks later. The pre- and postoperative concentrations (means +/- SEM) were, respectively, 238+/-45 nM and 126+/-19 nM for total cortisol, 15.5+/-2.6 nM and 8.4+/-1.3 nM for free cortisol in plasma, 13.4+/-4.3 x 10(-6) and 3.9+/-0.4 x 10(-6) for c/c in urine. The pre- and postoperative Bmax values of CBG were 41 and 79, and Kd values were 3.8 and 5.5. The concentrations of ammonia were 217+/-23 microM and 32+/-3.1 microM, and of bile acids 1 10+/-33 and 11.1+/-2.0 microM, respectively. We conclude that there is a close relation between portosystemic encephalopathy and hypercortisolism in dogs with PSS and that both deviations resolve completely within four weeks of closure of the shunt.

Effect of cholagogues on the volume of the gallbladder of dogs.

The effect of cholagogues on the volume of the gallbladder was studied by two-dimensional ultrasonography in six healthy dogs fasted for 24 hours. The volume was measured immediately before the administration of each test substance and at 10-minute intervals for 120 minutes thereafter. Tap water administered orally as a control did not elicit significant contractions; only the normal cyclic contractions of the gallbladder, occurring at intervals of 60 to 90 minutes, were recorded. Magnesium sulphate (500 mg as a 20 per cent aqueous solution given orally) and clanobutin (15 mg kg bodyweight-1 given intravenously) reduced the volume of the gallbladder by 24 per cent, and the volume then gradually increased at a rate which was almost identical for the two drugs. The cholagogic hormone cholecystokinin (administered intravenously at a dose rate of 0.04 microgram kg bodyweight-1) reduced the volume of the gallbladder by 40 per cent 10 minutes after its administration, and the volume was still markedly decreased 30 to 50 minutes after dosing. The results indicate that magnesium sulphate and clanobutin exert a direct effect on the motor activity of the gallbladder.