Richard M. Jakowski

p53 Expression and Environmental Tobacco Smoke Exposure in Feline Oral Squamous Cell Carcinoma

The purpose of this study was to determine the prevalence of p53 overexpression in feline oral squamous cell carcinomas (SCC) and to determine, if any, the association between p53 overexpression and lifestyle factors and environmental exposures, including exposure to environmental tobacco smoke (ETS). Questionnaires concerning exposure to ETS and other environmental factors were sent to owners of cats presenting to the Harrington Oncology Program with a diagnosis of oral SCC between 1991 and 2000. Additionally, 23 formalin-fixed biopsy samples from these cats, with information regarding ETS, were evaluated immunohistochemically for p53 expression using the CM-1 clone and the avidin-biotin-horseradish peroxidase method. Of the 23 samples evaluated, 15 (65%) showed positive nuclear staining for the CM-1 clone. Tumor biopsy samples from cats exposed to any ETS were 4.5 times more likely to overexpress p53 than were tumors from unexposed cats (P = 0.19). Among cats with any ETS exposure, those with 5 years or longer of exposure were 7.0 times more likely to overexpress p53 (P = 0.38). Longhaired cats (P = 0.18) and female cats (P = 0.35) were also more likely to show p53 expression in their tumors. These results provide additional support for a relationship between oral SCC development and exposure to household ETS and may implicate p53 as a potential site for carcinogen-related mutation in this tumor.

Chylothorax and chylous ascites in a dog with mediastinal lymphangiosarcoma.

A 10-year-old, male toy poodle presented for evaluation of a progressively worsening, harsh, nonproductive cough. Chylous pleural effusion, lymphopenia, thrombocytopenia, normoblastemia, and recurrent subcutaneous bruising were diagnosed. Surgical exploration of the cranial mediastinum revealed extensive, redundant connective tissue which was confirmed by histopathology to be mediastinal lymphangiosarcoma (LAS). During surgical placement of a fenestrated silastic mesh for passive pleuroperitoneal drainage, chylous ascites also was diagnosed. The patient was euthanized two days postoperatively due to persistent chylothorax. The etiopathogenesis of chylothorax and chylous ascites are discussed. Previous case reports of lymphatic endothelial neoplasia are reviewed.

Adenomatous Polyp With Intestinal Metaplasia of the Esophagus (Barrett Esophagus) in a Dog

Multiple endoscopic biopsy specimens of esophageal mucosa were received from a 13-year-old castrated male standard Poodle. The dog was presented for painful swallowing. Endoscopically, the distal aspect of the esophagus was inflamed with a polypoid mass that protruded into the esophageal lumen. Histologically, the stratified squamous epithelium overlying the mass and lining the adjacent esophageal mucosa was replaced by papillary projections covered by columnar epithelium with goblet cells supported by a fibrous stroma. This article reports a case of spontaneous esophageal adenomatous polyp with intestinal metaplasia (Barrett esophagus) and reviews the pathogenesis of esophageal metaplasia and adenocarcinoma.

Anaplastic Astrocytoma in the Spinal Cord of an African Pygmy Hedgehog (Atelerix albiventris)

A 2–year-old, female hedgehog presented with an 8–month history of progressive, ascending paresis/paralysis and was tentatively diagnosed with wobbly hedgehog syndrome. She died awaiting further diagnostic tests, and the owners consented to postmortem examination. Grossly, the bladder was large and flaccid and the cervical and lumbar spinal cord were regionally enlarged, light grey, and friable with multifocal hemorrhages. The thoracic spinal cord was grossly normal. Microscopically all regions of the spinal cord had similar changes, although the cervical and lumbar sections were most severely affected. These regions were completely effaced by a moderately cellular infiltration of highly pleomorphic polygonal to spindle shaped cells, mineralization, and necrosis, which were most consistent with anaplastic astrocytoma. The thoracic spinal cord white matter was similarly infiltrated by the neoplastic cells, with perivascular extension into the otherwise normal grey matter. A diagnosis of anaplastic astrocytoma was confirmed using immunohistochemical stains that were positive for glial fibrillary acidic protein and S100.

Adult-onset lysosomal storage disease in a Schipperke dog: clinical, morphological and biochemical studies.

SummaryAn adult-onset lysosomal storage disorder was diagnosed in a 5-year-old Schipperke dog with progressive cerebellar and central vestibular signs. It was characterized by cerebellar atrophy with extensive loss of Purkinje and granular cells, and hydrocephalus. Enlarged and vacuolated neurons were observed in spinal cord and brain; pancreatic centrolobular and islet cells were also vacuolated. Ultrastructurally, enlarged secondary lysosomes laden with lamellated membrane structures were present in neurons and empty enlarged vacuoles were found in pancreatic centroacinar, ductal, and islet cells. On frozen sections neurons stained with Ricinus communis agglutinin-I and wheat germ agglutinin. On paraffin sections neurons stained with luxol fast blue, periodic acid-Schiff, Concanavalia ensiformis agglutinin, and were autofluorescent. These findings indicate an accumulation of glycolipids containing terminal β-galactosyl and α-sialyl residues, and N-linked oligosaccharides. Tissue activity of lysosomal β-galactosidase was 50% of normal and the activity of β-hexosaminidase was elevated. Brain lipid-bound sialic acid was twice normal, with a small increase of GM1-ganglioside, but there was a significant elevation of GM2 (GD2) and GM3 (GD3). In addition, significant elevations of sialylated and non-sialylated oligosaccharides were noted. These clinical, biochemical and pathological findings are similar to those observed in human patients with adult-onset galactosialidosis.

Diagnosis, treatment, and temporary remission of disseminated paecilomycosis in a vizsla

A case of disseminated paecilomycosis in a three-year-old vizsla is described. Clinical signs of lethargy, weight loss, lymphadenopathy, diarrhea, and vestibulocochlear deficits were exhibited. Dense colonization of bone marrow by the fungus was found early in the disease course. Serial culture of bone-marrow aspirates and in vitro sensitivity testing helped monitor disease progression and guide antifungal therapy. Clinical and laboratory parameters demonstrated marked improvement for a period of 12 weeks. Multisystemic disease with central nervous system involvement was found at necropsy.

Experimental Evaluation of Absorbable Copolymer Staples for Hysterectomy

&NA; Absorbable copolymer staples of three different variants were tested for retention of tensile strength after implantation into the peritoneal cavity of rats. One type maintained tensile strength for two weeks, but then lost it rapidly over the next week. The same three staple compounds were further compared after use for vaginal vault closure during ovariohysterectomy in adult sheep. In all ewes the absorbable staples were effective in providing a stable vaginal cuff closure. The postoperative tissue reaction was minimal. The goal of developing an absorbable staple that would degrade rapidly without compromising wound stability was achieved. (Obstet Gynecol 68:404, 1986)