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.

Composite urinary reservoir in dogs: histological findings.

Purpose: This animal study was designed to investigate whether the composite urinary reservoir might lessen the premalignant histological alterations observed after bladder augmentation performed with a gastric segment or large bowel.

Materials And Methods: Composite urinary reservoirs were created using gastric and colonic segments simultaneously in 8, 3-month-old female beagle dogs by augmenting half the native bladder. Two dogs with gastrocystoplasty and 2 with colocystoplasty served as controls.

Expression of claudin-4 molecule in canine exocrine pancreatic acinar cell carcinomas.

Aims: Claudins, integral membrane proteins are components of the tight junction structures between epithelial and endothelial cells. These transmembrane proteins create a primary barrier to prevent paracellular transport of solutes, and also restrict the lateral diffusion of membrane lipids and proteins to maintain the cellular polarity. The aim of the present study was to characterise the expression pattern of claudin-4 tight junction molecule in canine normal pancreatic tissues and in the well-differentiated and poorly-differentiated pancreatic acinar cell carcinomas in canines.

Prognostic significance of claudin expression changes in breast cancer with regional lymph node metastasis.

Adherent and tight junction molecules have been described to contribute to carcinogenesis and tumor progression. Additionally, the group of claudin-low tumors have recently been identified as a molecular subgroup of breast carcinoma. In our study, we examined the expression pattern of claudins, beta-catenin and E-cadherin in invasive ductal (IDCs) and lobular (ILCs) carcinomas and their corresponding lymph node metastases (LNMs).

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.

Expression of claudin-1, -3, -4, -5 and -7 proteins in low grade colorectal carcinoma of canines.

Unlabelled: The aim of the present study was to characterise the expression pattern of claudin-1, -3, -4, -5 and -7 tight junction proteins in canine normal colorectum and in the low-grade, tubulopapillary colorectal carcinoma in canines.

Methods And Results: The biopsy samples included 10 canine normal colorectal tissues and 20 canine low grade colorectal carcinomas (CLGCCs). The canine normal colorectal mucosa was negative for claudin-1.

Claudin-5 protein is a new differential marker for histopathological differential diagnosis of canine hemangiosarcoma.

Aims: Claudin-5 protein is an endothel-specific claudin, present in tight junctions. To evaluate its usefulness as a differential diagnostic marker of canine hemangiosarcomas, the expression of claudin-5 molecule was studied in different canine tumours of vascular origin.

Methods And Results: Ninety two canine neoplastic tissue samples obtained from necropsies and biopsy specimens were routinely processed and stained immunhistochemically for claudin-5.

Expression of claudin-1, -2, -3, -4, -5 and -7 proteins in benign and malignant canine mammary gland epithelial tumours.

Claudins are tight junction proteins expressed by epithelial and endothelial cells. The present study has evaluated the expression of claudin-1, -2, -3, -4, -5 and -7 in 115 hyperplastic and neoplastic lesions of the canine mammary gland and compared this expression with that of normal mammary epithelium. The lesions studied included lobular hyperplasia (n=15), simple adenoma (n=20), non-infiltrating carcinoma in situ (n=20) and infiltrating carcinomas of histological grades I, II and III (n=20 of each).

Magnetic resonance imaging technique for the examination of canine mammary tumours.

The aim of this study was to adapt the human magnetic resonance imaging (MRI) sequences for use in the routine examination of canine mammary glands. MRI was performed on 10, middle- to old-aged dogs of different breeds. It was found that T1- and T2-weighted spin echo, short T1 inversion recovery sequences and a gradient echo (GE) dynamic T1-weighted measurement made in the coronal and transversal planes were the most informative MR diagnostic methods for imaging canine mammary tumours.