Immunocytochemical detection of amylase, carboxypeptidase A, carcinoembryonic antigen and alpha 1-antitrypsin in carcinomas of the exocrine pancreas of the dog.

The immunocytochemical detection of amylase, carboxypeptidase A, alpha 1-antitrypsin, carcinoembryonic antigen (CEA) and keratin in normal canine pancreatic tissue and in carcinomas of the exocrine pancreas of the dog is described. In the normal pancreas, the acinar cells contain amylase, carboxypeptidase and alpha 1-antitrypsin. The pancreatic ducts react with the antikeratin antibody. Twelve out of 14 pancreatic exocrine carcinomas showed immunoreaction with antiamylase antibody, and 10 with anticarboxypeptidase antibody. Five neoplasms reacted with anti-CEA antibody and three with the anti-alpha 1-antitrypsin antibody. It was not possible to find any systematic difference in the immunocytochemical profiles of acinar, tubular and undifferentiated carcinomas. These results indicate that immunocytochemical marking of amylase and carboxypeptidase is of value in the diagnosis of pancreatic neoplasms in the dog, especially if metastasis is the only material available for study and the tumour does not show any diagnostic feature on routine light microscope preparations.     

Lectin histochemistry on squamous metaplasia in different epithelial tumors of dogs.

Biotinylated lectins and avidin-biotin-peroxidase complex were used to study the correlation between cellular glycoconjugates' expression and squamous maturation in normal canine skin and in various epithelial neoplasms. Normal skin tissue was obtained from five, male, random-source dogs, 5 to 7 years old. The tumors tested, selected from the files of our Department, were fifteen squamous cell carcinomas from different tissue origin, five hepatoid perianal gland adenocarcinomas with squamous metaplasia, and fourteen solid mammary carcinomas with and without histologic evidence of squamous metaplasia. Except for mammary gland carcinomas, all tumors had been surgically excised from male dogs. Intermediate filament aggregation of twelve solid mammary gland carcinomas were studied electron microscopically. The basal and the lower spinous cells in normal skin and the less differentiated cells in squamous cell carcinomas stained moderately with Griffonia simplicifolia agglutinin-I. Spinous and granular cell layers stained strongly with Phytolacca americana mitogen and Arachis hypogaea agglutinin. Both lectins stained well-differentiated cells in squamous cell carcinomas. The electron microscopic study carried out in solid carcinomas of mammary glands revealed some relationship between the presence of intracytoplasmic tonofibrils and the binding of Griffonia simplicifolia agglutinin-I and Phytolacca americana mitogen to the tumors tested. Our results suggest that the glycosylation pattern occurring during normal keratinocyte differentiation is conserved in squamous cell carcinomas and that Griffonia simplicifolia agglutinin-I and Phytolacca americana mitogen may represent useful tools in distinguishing poorly differentiated squamous cell carcinomas from other poorly differentiated mammary epithelial tumors.     

Pancreatic Degenerative Atrophy and Chronic Pancreatitis in Dogs a Comparative Study of 60 Cases

During the years 1977–1980 60 cases of non-neoplastic chronic exocrine pancreatic disease in dogs were investigated clinically and pathologically. The disorders were clinically divided into pancreatic degenerative atrophy (PDA) and chronic pancreatitis. Fifty dogs had PDA and 45 of them were German shepherd dogs. The PDA cases formed both clinically and pathologically a homogeneous group except for 1 case. All the dogs had maldigestion and protease activity was absent from the faeces. General inanition and highly atrophic pancreas were the most typical macroscopic findings. Histologically the exocrine pancreas contained atypical acinar tissue and mononuclear cell infiltrations. Five of the dogs died spontaneously, 4 of them had intestinal torsion and 1 had paralytic ileus.There were 10 dogs with chronic pancreatitis. This group was rather heterogeneous both clinically and pathologically. The pancreas was slightly enlarged and the consistency was firm. The histologic picture was one of fibrous tissue proliferation and inflammatory cell infiltrations in the interstitium. The dogs nutritional state as well as faecal protease activity were normal.     

Cellular and humoral immune responses in atrophic lymphocytic pancreatitis in German shepherd dogs and rough-coated collies

The most common cause for the clinical signs of exocrine pancreatic insufficiency (EPI) in dogs is pancreatic acinar atrophy (PAA). In the subclinical phase of EPI, before total atrophy occurs, exocrine pancreas is affected by infiltrative lymphocytic inflammation, which gradually leads to selective destruction and atrophy of the acinar tissue.Here, we analyzed the role of cell-mediated and humoral immune mechanisms in the pathogenesis of atrophic lymphocytic pancreatitis in German shepherd dogs and rough-coated collies. Pancreas biopsies and serum samples were obtained from 12 dogs with subclinical EPI (SEPI), 13 dogs with clinical EPI and 13 healthy control dogs.Immunohistochemical analysis showed that, in the subclinical phase, the majority of the infiltrating lymphocytes were T-cells with an almost equal number of CD4+ 'T-helper' and CD8+ 'cytotoxic' T-lymphocytes. The distribution of the two lymphocyte subsets was different. Typically, the CD4+ cells were present in large cellular infiltrates in the affected parenchyma, and the scattered CD8+ cells had infiltrated both the affected and the normal parenchyma. In sections where destruction of acinar parenchyma was present, the CD8+ T-cells were predominant. In cases of marked T-cell infiltration, CD79+ B-lymphocytes and plasma cells, and lysozyme-positive macrophages were also detected. Lymphoid follicle germinal centers with a majority of cells staining positively for CD79 were found. The lymphocytic infiltration in the totally atrophic tissue of dogs with clinical EPI was less prominent. Indirect immunofluorescence staining showed serum antibodies reacting weakly with pancreatic acinar cells in five out of nine dogs with subclinical and three out of 10 dogs with clinical EPI, but not in the control dogs.The results suggest that the tissue destruction is largely T-cell-mediated, although the presence of numerous B-lymphocytes and pancreas-specific antibodies in the sera of some dogs indicate that humoral mechanisms are also involved. In conclusion, this study suggests that the atrophic lymphocytic pancreatitis in German shepherds and rough-coated collies is an autoimmune disease.     

Cyclooxygenase-2 expression in feline pancreatic adenocarcinomas.

Cyclooxygenase-2 (COX-II) is an inducible enzyme that is responsible for the production of prostaglandin E2 (PGE2), which is often upregulated in neoplastic conditions. Expression of COX-II is documented in the majority of human pancreatic adenocarcinomas and in many epithelial neoplasms in humans and animals. The purpose of this study was to assess a series of feline pancreatic adenocarcinomas for the expression of COX-II. Eight feline pancreatic adenocarcinomas (5 poorly differentiated ductular variants and 3 well-differentiated acinar variants) were included. Immunohistochemical staining showed that COX-II was expressed in 2 (both poorly differentiated ductular variants) of the 8 neoplasms (25%). Approximately 10% of the epithelial cells from these 2 neoplasms expressed intense cytoplasmic staining. However, because feline pancreatic adenocarcinoma does not appear to consistently express COX-II, it is not a useful prognostic indicator for this group of feline neoplasms. In addition, COX-II inhibitors are not likely to be effective therapeutics for cats with this neoplasm.     

Expression of the sweet receptor protein, T1R3, in the human liver and pancreas

The expression of T1R3, a taste receptor essential for the perception of sweetness and umami-taste, was examined by immunohistochemistry to determine whether and where it may be localized in the liver and pancreas. In the liver, both immunopositive and immunonegative reactions were detected; bile ducts and intercalated portions of the bile ductules were immunopositive to T1R3, while arterioles and venules were immunonegative in interlobular connective tissue. In the hepatic lobule, all other cells including liver cells (hepatocytes) and bile capillaries were immunonegative. In the pancreas, all endocrine portions of the pancreas were immunonegative to T1R3. Within the exocrine portions, immunopositive reactions were detected in excretory duct cells, intercalated cells, and centroacinar cells. In contrast, acinar cells were immunonegative, as were vessels, lymph capillaries, nerve fibers, and connective tissue cells in the exocrine portions. The restricted localization of T1R3 in the duct cells of the liver and pancreas in the present study may indicate that T1R3 is involved in monitoring changes in the makeup of bile and pancreatic juices in the hepatic and pancreatic duct systems.     

Exocrine Pancreatic Insufficiency in the Dog: Historical Background,Diagnosis, and Treatment

This overview summarizes research performed during the last decades that has had an impact on the diagnosis and management of exocrine pancreatic insufficiency (EPI) in dogs. Pancreatic acinar atrophy is by far the most common cause for the maldigestion signs of canine EPI. The ability to diagnose pancreatic acinar atrophy in the subclinical phase before the development of total acinar atrophy and manifestation of clinical signs has offered new possibilities to study the pathogenesis of the disease. Diagnosis of exocrine pancreatic dysfunction is based on typical findings in clinical histories and clinical signs and is confirmed with pancreatic function tests. In recent years, the measurement of serum canine trypsin-like immunoreactivity has become the most commonly used pancreatic function test to diagnose canine EPI. Serum trypsin-like immunoreactivity measurement is species- and pancreas-specific. When clinical maldigestion signs of EPI appear, enzyme replacement therapy is indicated. Despite accurate enzyme supplementation, only a small portion of orally administered enzymes are delivered functionally intact into the small intestine. In dogs, the highest enzyme activity in the duodenum has been obtained with nonenteric-coated supplements: raw chopped pancreas or powdered enzymes. Aside from dietary enzyme supplements, dietary changes are often made to improve clinical response, but sometimes weight gain and stool quality remain suboptimal. Other medications for treatment of gastrointestinal tract signs are often used in such dogs with EPI. Antibiotics are the most common adjunctive medication. Of the antibiotics administered, tylosin is used in Finland almost exclusively.     

Juvenile Pancreatic Atrophy in Greyhounds: 12 Cases (1995–2000)

Background: This study describes compound failure of the endocrine and exocrine pancreas in Greyhounds, a condition that has not been reported in the veterinary literature.
Objective: To describe the clinical and pathologic findings in 12 Greyhounds with juvenile pancreatic atrophy.
Animals: Ten Greyhounds presented for necropsy examination and 2 sibling Greyhounds presented for clinical evaluation before necropsy, all with a history of small-bowel diarrhea.
Procedures: Retrospective study of laboratory and pathologic findings in 12 Greyhounds, including serum trypsin-like immunoreactivity assays, oral glucose tolerance testing, and serum anti-insulin antibody concentrations.
Results: Gross pancreatic atrophy was found in all 12 dogs. Histopathologic lesions were found in both the endocrine and exocrine pancreas and included acinar cell apoptosis, zymogen granule loss, cytoplasmic clearing or vacuolar change, lobular atrophy, islet loss, and lymphocytic or lymphoplasmacytic pancreatitis. Antemortem test results on the 2 Greyhound puppies indicated concurrent exocrine pancreatic insufficiency (EPI) and insulin-dependent diabetes mellitus (IDDM).
Conclusions and Clinical Importance: Compound failure of the exocrine and endocrine pancreas is rarely reported in dogs and neither disease is well recognized in the Greyhound. This condition is of potential economic importance to the Greyhound racing industry.     

Morphologic and immunocytochemical study of young dogs with diabetes mellitus associated with pancreatic islet hypoplasia

In 11 dogs (7 males, 4 females; 10 purebred, 1 mixed breed), diagnosed as having diabetes mellitus before the age of 6 months, the pancreas was evaluated histologically; in 6, the pancreas also was examined by use of electron microscopy and/or immunocytochemical methods. Each dog was placed in 1 of 3 groups (A through C) on the basis of pancreatic histopathologic findings: Group A (n = 3)--no recognizable islets, but the pancreas in 2 dogs contained scattered endocrine cells detectable by use of immunoperoxidase staining or electron microscopy; Group B (n = 4)--no recognizable islets, but the pancreas had severe vacuolation of ducts and acini, as well as acinar atrophy; Group C (n = 4)--scant shrunken islets; 1 pancreas had reduced numbers of recognizable islets, hydropic beta-cell vacuolation attributable to glycogen deposition, and islet and nonislet endocrine cells in expected proportions. Insulitis was not observed in any pancreas, although scattered lymphocytes were seen in the pancreatic interstitial fibrous tissue of 3 dogs. Histologic pancreatic lesions in these young dogs were distinct from those of type-I (insulin-dependent) diabetes mellitus in human beings, as well as from those of diabetes mellitus in aged dogs, but were similar to those described in other young diabetic dogs. This uncommon syndrome is distinct from commonly recognized canine diabetes mellitus, on the basis of age of onset, predisposition for purebred dogs, lack of predisposing endocrinopathies or obesity, and pancreatic histologic features. The cause(s) is unknown, but is related to pancreatic endocrine hypoplasia and not to insulitis or to exocrine pancreatic inflammation. The term pancreatic islet hypoplasia is chosen as best describing this disorder.     

Exocrine pancreatic atrophy in German Shepherd Dogs and Rough-coated Collies: an end result of lymphocytic pancreatitis

Previously published studies of the pathology of canine exocrine pancreatic insufficiency (EPI) have been based on morphological findings during the clinical phase of the disease, when atrophy of acinar parenchyma occurs. Recently, low serum trypsinlike immunoreactivity (TLI) concentration has been shown to precede clinical signs, making it possible to diagnose EPI prior to onset of the clinical disease. This study presents histological and ultrastructural findings of pancreatic biopsies from 11 German Shepherd Dogs and 2 Rough-coated Collies with subclinical EPI (SEPI). These findings were compared with those from dogs with clinical EPI (n = 11) and healthy control dogs (n = 5). Biopsied tissue from dogs with SEPI typically contained both normal and atrophied acinar parenchyma. The most significant finding was the marked lymphocytic infiltration, which was most prevalent at the border zone of affected and nonaffected parenchyma but had spread into the normal acinar tissue. Numerous intraacinar lymphocytes were found. Most of the lymphocytes were positive by immunostaining for CD3. In more advanced stages of destruction, the findings were characteristic of pancreatic acinar atrophy. In the atrophied parenchyma, the inflammatory reaction, if present, was less prominent. Ultrastructural changes were in accordance with those of the histological study showing infiltration of lymphocytes both in affected acini and in acini that revealed no obvious ultrastructural changes. Progressive degenerative changes of acinar cells were considered a nonspecific finding. Apoptotic death of acinar cells was occasionally found. The inflammatory reaction was clearly shown to precede the pancreatic acinar atrophy, and the findings suggested that lymphocytic pancreatitis leads to atrophy of the pancreas. The possibility that EPI is an immune-mediated disease in German Shepherd Dogs and Rough-coated Collies is discussed.     

Pancreatic acinar atrophy in German shepherd dogs and rough-coated collies. Etiopathogenesis, diagnosis and treatment. A review

In pancreatic acinar atrophy (PAA) a selective destruction of digestive enzyme-producing acinar cells leads to maldigestion signs typical of exocrine pancreatic insufficiency (EPI). Although the clinical disease is well-known, the etiopathogenesis of PAA has been long remained obscure. German shepherd dogs and rough-coated Collies with PAA show similar genetic, clinical and pathological findings indicating a similar etiopathogenesis of the disease in these two breeds. In this review article the etiopathogenesis of PAA is discussed, including the current suggestion of autoimmune nature of the disease. The diagnostic methods for detection both early and end-stage exocrine pancreatic dysfunction are described, as well as the treatment options and prognosis.     

Histopathological Changes in the Pancreas from a Spontaneous Hyperglycemic Cynomolgus Monkey

Morphological and immunohistochemical examinations were carried out on the pancreas of a hyperglycemic 5-year-old male cynomolgus monkey. Body weight gradually decreased from 6 months before termination, accompanying a slight reduction in food consumption and anorexia for the last 2 days. The blood glucose level was markedly elevated when examined at termination. Histopathologically, in the exocrine pancreas, diffuse hyperplasia of centroacinar and intercalated duct cells and diffuse atrophy of acinar cells with sporadic apoptosis were observed, although most centroacinar and intercalated duct cells were proliferating cell nuclear antigen (PCNA)-positive in both the present case and age-matched control animals. In the endocrine pancreas, the islets tended to be hypertrophic, with an increase in insulin-positive cells in comparison with the age-matched control animals. PCNA-positive cells also tended to increase in the islets, although positive cells for phospho-histone H3, a marker for mitotic cells, were not detected in the endocrine and exocrine pancreas. Moreover, neither inflammation nor amyloidosis was noted in the islets. In conclusion, the present case probably suffered from early-stage type 2 diabetes mellitus, and it provides fundamental information concerning pancreatic histopathology under insulin-related derangement in monkeys.     

Histopathological changes in the pancreas due to decreased pancreatic blood flow in a canine tachycardia-induced cardiomyopathy model

In dogs, pancreatic acinar cell injury is thought to be caused by decreased pancreatic blood flow due to heart failure. In previous our report, it demonstrated that decreased heart function causes a significant decrease in pancreatic blood flow in heart failure dog model caused by rapid ventricular pacing (RVP). However, the types of histopathological changes remain unclear. We aimed to verify the types of histopathological changes occurring in the pancreatic tissue due to decreased heart function. After RVP for 4 weeks, atrophy of pancreatic acinar cells, characterized by a decrease in zymogen granules, was observed in all areas of the pancreas. In conclusion, the result of this study suggests that attention should be paid to ischemia/hypoperfusion injury in the pancreas.     

Relationships between the histological grade of cutaneous mast cell tumours in dogs, their survival and the efficacy of surgical resection

The histological grade of 340 cutaneous mast cell tumours derived from 280 dogs was determined by an established histological grading system; 87 of the tumours (26 per cent) were well differentiated, 199 (59 per cent) were intermediately differentiated and 54 (16 per cent) were poorly differentiated. The one-year survival rates for the dogs with tumours of these three grades were significantly different (P = 0.0001), being 100 per cent, 92 per cent and 46 per cent, respectively. The median survival time for the dogs with poorly differentiated tumours was 278 days, significantly shorter than that for the dogs with either intermediately or well-differentiated tumours, which were both over 1300 days. Regrowth of the tumours was identified in 10 (19 per cent) of the dogs with poorly differentiated tumours, 12 (6 per cent) of the dogs with intermediately differentiated tumours and one of the dogs with well-differentiated tumours; only three of the tumours which regrew had initially had complete margins. The results suggest that wide surgical margins are not a prerequisite for a successful long-term outcome in dogs with well-differentiated cutaneous mast cell tumours.     

ENDOSCOPIC ULTRASONOGRAPHIC FINDINGS OF THE PANCREAS AFTER PANCREATIC DUCT LIGATION IN THE DOG

Endoscopic ultrasonographic evaluation and gray-scale histogram analysis of pancreatic atrophy after pancreatic duct ligation were performed in four normal adult dogs. Using endoscopic ultrasonography, markedly dilated pancreatic ducts were visualized, and the pancreas became gradually atrophied with a hyperechoic parenchyma. In gray-scale histogram analysis of the pancreas, mean brightness increased gradually until 8 weeks, then decreased temporally. Standard deviation of the histogram increased markedly and then fluctuated until the 4th week, after which the mean brightness and standard deviation became stable. At 4 weeks postoperatively, collapse of most pancreatic acinar structures were observed, and each atrophic lobule was associated with a significantly large amount of interstitial fibrous tissue at histopathology. At 12 weeks postoperatively, most exocrine tissue had decreased and was partly replaced by fibrous and fatty tissue. These changes of mean brightness and standard deviation reflected the histologic analysis. These findings indicated that endoscopic ultrasonography is a useful technique to image such atrophic disorders of the pancreas as chronic pancreatitis. Furthermore, gray-scale histogram analysis provides helpful information for ultrasonographic tissue characterization of the pancreas.     

The effect of pentaghrelin on amylase release from the rat and porcine dispersed pancreatic acinar cells in vitro

Ghrelin-28 was found to inhibit the pancreatic enzyme output in rats, although the effect of pentaghrelin has not been studied. The effect of ghrelin on pig exocrine pancreas remains largely unknown. The aim of the present study was: (1) to establish a model of porcine dispersed pancreatic acinar cells in vitro and compare it with an existing rat model, and (2) to investigate the effect of pentaghrelin on amylase release from the rat and pig pancreatic acini. The rat and porcine acinar cell preparations released amylase in response to cholecystokinin octapeptide (CCK-8) stimulation in a dose-related manner. Pentaghrelin hardly inhibited the amylase release in rat preparations (maximum inhibition with 10^− 9 M pentaghrelin). It stimulated amylase release in porcine preparations, however, no dose response was found in a range of doses between 10^− 10 and 10^− 7 M. Concluding, pentaghrelin may stimulate amylase release from porcine acinar cells through as yet unknown mechanisms.     

Advances in canine diabetes mellitus research: etiopathology and results of islet transplantation

Histopathologic and immunocytochemical alterations in the pancreas of 18 dogs with spontaneous diabetes mellitus were evaluated. In 5 of 18 dogs (28%), extensive pancreatic damage appeared to be responsible for the development of diabetes mellitus. In the other 13 dogs, there was substantial reduction in the number of well-granulated beta cells, but the number of well-granulated alpha and delta cells was normal in 70% and 85% of the dogs, respectively. Also, insulitis lesions composed of infiltrating mononuclear cells, predominantly lymphocytes, were observed in 6 of 13 dogs (46%), but evidence of islet-directed humoral autoimmunity was not detected. Each pancreas had dense Ia (class II antigen) expression on ductal epithelia but not on islet endocrine cells. The importance of the insulitis lesions and class II antigen expression on ductal epithelial cells remains unclear. Of the 18 dogs, 8 received multidonor intrahepatic islet allografts. Allograft rejection was prevented by administration of cyclosporin. Five dogs were administered cyclosporin continuously. One dog with an allograft failed to sustain euglycemia at 231 days after transplantation, and one dog with fasting euglycemia died of pneumonia at 186 days after transplantation. In the other dogs, euglycemia was sustained for periods that ranged from 253 to 716 days.     

Experimental encephalomyocarditis virus infection in Mongolian gerbils (Meriones unguiculatus)

Two strains of Mongolian gerbils (Meriones unguiculatus), Tumble Brook (TUM) and Japan Medical Science (JMS), were intraperitoneally inoculated with the D variant of encephalomyocarditis virus (EMC-D) and killed 3 days later. Mortality was significantly higher in females than in males. Evidence of viral replication was detected in the heart of both strains and in the pancreas of the TUM strain. Histopathological alterations were found in the heart and pancreas. Heart lesions involved foci of necrosis with inflammatory cell infiltration and calcification in both strains. Pancreatic lesions were restricted to the exocrine glands; islets of Langerhans were rarely and secondarily involved in the extensive destruction of exocrine glands. Severe acinar cell necrosis with marked inflammatory edema was conspicuous in TUM, whereas only slight acinar cell involvement was detected in JMS gerbils. Immunoperoxidase staining showed viral antigens in intracytoplasmic vacuoles in damaged acinar cells.     

Serum isoamylase values in normal dogs and dogs with exocrine pancreatic insufficiency

Estimations were made of the serum isoamylase values of normal dogs and of dogs with confirmed exocrine pancreatic insufficiency. A statistically significant difference was demonstrated between the two groups in respect of the values of one of the isoamylase fractions measured. Further study has confirmed that canine salivary tissue lacks amylase activity and that the source of the isoamylase fractions was the pancreas.This knowledge has potential value in the diagnosis of canine exocrine pancreatic insufficiency.     

Loss of p27 expression in canine mammary tumors and their metastases

The p27 gene is a member of the cyclin-dependent kinase inhibitors, which arrest G1- to S-phase transition of the cell cycle. We have previously shown a significant reduction of p27 mRNA expression level in laser-microdissected mammary carcinomas and their lymph node metastases when compared to non-neoplastic mammary gland of the same dog. Here, p27 expression was analyzed on the protein level in non-neoplastic mammary gland, primary mammary carcinomas, their lymph node metastases and intravascular tumor cells of 49 dogs, adenomas of 49 dogs and non-neoplastic mammary gland of 98 dogs by immunohistochemistry. A significantly (p ? 0.05) decreased percentage of p27 positive tissue samples was found when normal gland was compared with adenomas, carcinomas and lymph node metastases. Specifically, 91% of normal gland epithelium displayed nuclear p27 expression. In contrast, only 22% of the adenomas, 20% of carcinomas, 12% of lymph node metastases and 32% of intravascular tumor cells had p27 reactivity. Cell cycle control by p27 is therefore lost in the majority of canine mammary tumors. The lack of significant differences between benign and malignant mammary tumors indicates that decreased p27 expression is an early step in carcinogenesis of canine mammary tumors and hinders the use of p27 as a marker of malignancy for this tumor type.