Biomedical subjects
R R Dubielzig
Publications and source records attributed to R R Dubielzig.
Inductive fibroameloblastoma, an unusual dental tumor of young cats.
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The nomenclature of periodontal epulides in dogs.
Epulides of periodontal origin are seen frequently in dogs. The classification of these tumors in the literature varies greatly and leads to much confusion when trying to compare reports from different sources. Our article reviews the literature regarding these tumors and suggests a standardized nomenclature. Three types of epulis are described. These are fibromatous epulis, ossifying epulis, and acanthomatous epulis, all of which are of periodontal origin. The three are grouped together because all have a stroma closely resembling normal periodontal ligament. The acanthomatous epulis has the potential to infiltrate locally into bone, whereas the other forms are not invasive.
The effect of canine distemper virus on the ameloblastic layer of the developing tooth.
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Tracheal osteochondroma in a young dog.
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Comments on gross postmortem examination of small animals.
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Preclinical development of human granulocyte-macrophage colony-stimulating factor-transfected melanoma cell vaccine using established canine cell lines and normal dogs.
Tumor vaccines and gene therapy have received significant attention as means of increasing cellular and humoral immune responses to cancer. We conducted a pilot study of seven research dogs to determine whether intradermal injection of canine tumor cells transfected via the Accell particle-mediated gene transfer device with the cDNA for human granulocyte-macrophage colony-stimulating factor (hGM-CSF) would generate biologically relevant levels of protein and result in demonstrable histological changes at sites of vaccination. Tumor cell vaccines of 10(7) irradiated canine melanoma cells were nontoxic, safe, and well tolerated. No significant alterations in blood chemistry values or hematological profiles were detected. A histological review of control vaccine sites revealed inflammatory responses predominated by eosinophils, whereas vaccine sites with hGM-CSF-transfected tumor cells had an influx of neutrophils and macrophages. Enzyme-linked immunosorbent assays of skin biopsies from vaccine sites had local hGM-CSF production (8.68-16.82 ng/site of injection) at 24 hours after injection and detectable levels (0.014-0.081 ng/site) for < or =2 weeks following vaccination. Flow cytometric analysis of hGM-CSF-transfected cells demonstrated < or =25% transfection efficiency, and hGM-CSF levels obtained during time-course assays demonstrated biologically relevant levels for both irradiated and nonirradiated samples. These data demonstrate the in vivo biological activity of irradiated hGM-CSF-transfected canine tumor cells and help provide evidence for a valid translational research model of spontaneous tumors.
Immunohistochemical properties of ocular adenomas, adenocarcinomas and medulloepitheliomas.
Ocular medulloepitheliomas, adenomas and adenocarcinomas share a common phenotype and originate from the optic cup neuroectoderm. This can make it very difficult to differentiate between these tumors histopathologically. Therefore, this study focused on identifying a combination of immunologic markers that might be used in the diagnosis of these tumors. These markers included AE1/AE3, CK7, CK20, and telomerase reverse transcriptase (TERT). Routine immunohistochemical staining was performed on 27 whole globes diagnosed with one of these tumors. The tumors that immunostained for TERT showed increasing immunoreactivity as the tumor types increased in aggressiveness. None of the tumor types were immunopositive for CK7. CK20 immunostaining was found in the adenomas but not in the adenocarcinomas or medulloepitheliomas. AE1/AE3 expression was present more consistently in the adenocarcinomas and less frequently in the adenomas. AE1/AE3 expression was present in only one of six medulloepitheliomas. Furthermore, CK20 and TERT showed inverse expression patterns, i.e. TERT increased in expression and CK20 decreased in expression with increasing aggressiveness. These results may be important diagnostic and prognostic indicators for these tumors.
Chemonucleolysis with collagenase. A radiographic and pathologic study in dogs.
Collagenase, a proteolytic enzyme, was injected intradiscally in nine clinically normal, middle-aged beagles. Calcium chloride diluent solution (control), 100 ABC units of collagenase, and 250 ABC units of collagenase, were injected in randomly selected intervertebral discs (T13-L1 to L5-L6). On day 11, the discs injected with collagenase were narrowed radiographically, but there was no significant change in myelograms. Grossly and histologically, there was dissolution of the intervertebral discs, mainly nucleus pulposus, and protrusion of nucleus material in the vertebral body through bony end-plates in discs injected with collagenase. Collagenase chemonucleolysis may be an alternative to spinal surgery for intervertebral disc protrusion in dogs.
Peripheral neuroblastoma in a dog.
Primitive neuroectodermal tumors are composed of primitive neuroepithelial cells and include tumors of the central and peripheral nervous system. Neuroblastoma, medulloblastoma and retinoblastoma are examples of these rare malignant tumors that usually occur in young patients. This report describes a peripheral neuroblastoma in a 2 year old Boxer that presented with signs of renal disease and a palpable abdominal mass. The purpose of this paper is to describe the clinical presentation, imaging and immunohistological studies of this abdominal tumor in a young dog and to review the literature.
Ultrasonography and fine needle aspirate cytology of the mesenteric lymph node in normal domestic ferrets (Mustela putorius furo).
The large mesenteric lymph node of 28 normal ferrets was imaged with ultrasound. The large node, located in the mid-abdomen at the root of the mesentery, was round to ovoid and uniformly hyperechoic. Mean ultrasonographic dimensions of the lymph node were 12.6 +/- 2.6 mm by 7.6 +/- 2.0 mm. Fine needle aspirates of 20 lymph nodes were obtained either using ultrasound guided free-hand techniques or at necropsy. The cytological descriptions were compared to histological descriptions of 13 lymph node core biopsies obtained during laparotomy or necropsy as well as 10 peripheral blood smear differentials. The large mesenteric lymph node of ferrets could be easily imaged and measured by ultrasound and evaluated by fine needle aspirate cytology. Normal lymph node cytology may include an eosinophilic infiltrate.
Effects of a specific thromboxane synthetase inhibitor on development of experimental Dirofilaria immitis immune complex glomerulonephritis in the dog.
Twelve Beagle dogs were immunized with aqueous-soluble Dirofilaria immitis antigens, and subsequent to at least fivefold increases in serum antibody titer, 6 mg of homologous antigen was infused into the left renal artery. Six dogs were treated once daily starting the day of infusion with 0.75 mg/kg of 1-benzylimidazole (1-BIM) in saline. Six control dogs were given saline only. Light, immunofluorescent, and transmission electron microscopic examinations of renal tissue from control dogs, 10 days after antigen infusion, showed a mesangioproliferative glomerulonephritis in the left kidney with polymorphonuclear leukocyte (PMNL) infiltration and fibrin deposition. Immunoglobulin (Ig) G, M, C3, and Dirofilaria antigen deposits were observed in a segmental granular pattern. Mesangial, subendothelial, and intramembranous electron dense deposits were observed, and anti-Dirofilaria antibodies were demonstrated in kidney eluates from each dog. Administration of 1-BIM had no significant effect on IgG, IgM, C3, or antigen deposits, electron dense deposits, or concentration of antibody in kidney eluates. However, 1-BIM-treated dogs had less glomerular cell proliferation, periodic acid-Schiff (PAS) positive glomerular staining, PMNL infiltration, and fibrin deposition. These data suggest that thromboxane is an important mediator in the development of immune complex glomerulonephritis, and that in certain circumstances, inhibition of thromboxane synthesis may be an effective therapy for immune complex glomerulonephritis in the dog.
Plasma histamine and gastrin concentrations in 17 dogs with mast cell tumors.
Dogs with mast cell tumors (MCT) are often affected with paraneoplastic syndromes such as gastrointestinal ulceration. The mechanism of ulceration is believed to be related to hyperhistaminemia. To test this hypothesis, plasma histamine and gastrin concentrations were measured in 17 dogs with MCT. Plasma histamine concentrations in dogs with MCT were significantly higher than those in normal dogs. Conversely, plasma gastrin concentrations in dogs with MCT were significantly lower than gastrin concentrations in normal dogs. Additionally, plasma gastrin concentrations were inversely related to plasma histamine concentrations, which provided indirect evidence for the presence of hyperacidity secondary to hyperhistaminemia (r2 = 57.7). Plasma histamine and plasma gastrin concentrations were not related to clinical stage of disease, tumor histologic grade, or tumor size. Median survival time was 245 days, with a range of 90 to 1315 days. Because the degree of hyperhistaminemia could not be predicted in this study from the clinical stage, histologic grade, or tumor size, these data suggest that hyperhistaminemia may occur in any dog with MCT.
Treatment of membranoproliferative glomerulonephritis and nephrotic syndrome in a dog with a thromboxane synthetase inhibitor.
A 2-year-old spayed female Whippet with membranoproliferative glomerulonephritis and nephrotic syndrome was treated with a specific thromboxane synthetase inhibitor (3-methyl-2[3-pyridyl]-1-indoleoctanoic acid), resulting in decreased proteinuria and resolution of ascites and edema. Glomerular histology, however, appeared unaffected by treatment. Discontinuation of treatment for 10 weeks resulted in increased proteinuria and decreased serum albumin concentrations that were again attenuated when treatment was reinitiated. Thromboxane synthetase inhibitors have been used successfully to treat experimentally induced glomerulonephritis in several species and this treatment appears to hold promise for naturally occurring glomerulonephritis in dogs.
Temperature distributions, microangiographic and histopathologic correlations in normal tissue heated by ferromagnetic needles.
Rabbit hind limb musculature implanted with nine ferromagnetic nickel-copper alloy needles was inductively heated in a 120 kHz oscillating magnetic field. Rabbits were heated every third day for a total of three 30 min heating periods. Ferromagnetic needles with Curie points of 42 degrees C, 45 degrees C, and 48 degrees C were used. Fourteen days following the third heating the animals were sacrificed and the tissues processed for microangiography and histopathology. Implanted muscle heated rapidly and achieved a stable temperature within 10 min. Two weeks after heating for three 30 min heat cycles at temperatures above 47.1 degrees C, both vasculature destruction and muscle necrosis were noted. However, at temperatures below 45.5 degrees C, histopathologic and microangiographic findings were indistinguishable from unheated, implanted controls. Myocentric granuloma formation surrounding the thermoseed tracks with vascular preservation characterized tissue at a steady-state temperature between 45.5 degrees C and 47.1 degrees C. Nickel-copper alloy thermoseeds were effective at producing reproducible, localized interstitial hyperthermia. Chronic vascular and histopathologic alterations correlated closely with previous steady-state temperatures.
Evaluation of bovine fibrin sealant in the dog.
Fibrin sealant (human fibrinogen-bovine thrombin) is an effective biodegradable hemostatic agent. However, there is a risk of transmission of infectious viral disease. A new bovine fibrinogen-thrombin sealant (BFTS) was tested for tissue and immune responses in intrathoracic aorta graft in dogs. Intrathoracic aorta replacement was performed in three dogs with a porous Dacron graft presealed with BFTS. Dogs were immunized preoperatively with four dermal applications of BFTS at 9-day intervals. Cellular and humoral immunity to BFTS were determined with lymphocyte blastogenesis test and enzyme-lined immunosorbent assay, respectively. Dogs were necropsied 3 weeks after aortic replacement. Histopathological examination showed that all dogs had a mild inflammatory reaction to the BFTS sealed graft, as expected in response to an inert foreign body. Assay of cellular and humoral immunity to BFTS revealed a low lymphocyte response and a moderate immunoglobulin G (Ig G) response, with no evidence of immediate Ig E (type I) or delayed (type IV) hypersensitivity reaction. We conclude that BFTS causes no adverse tissue response or immunologic reaction when used as a hemostatic agent in the dog even after multiple applications of the material.
Hepatocellular necrosis associated with the subcutaneous injection of an intranasal Bordetella bronchiseptica-canine parainfluenza vaccine.
A three-year-old wire fox terrier inadvertently was given an intranasal Bordetella bronchiseptica and canine parainfluenza vaccine subcutaneously. The dog subsequently developed both a local inflammatory reaction at the injection site and acute, nonseptic hepatocellular degeneration and necrosis. The patient was treated successfully with intravenous fluids and amikacin. Two months after the injection, the serum bile acid concentrations and hepatic histopathology indicated the presence of continued hepatocellular disease.
Malignant mesenchymoma associated with an unusual vasoinvasive metastasis in a dog.
A case of a malignant mesenchymoma with an unusual, vasoinvasive, metastatic behavior in a three-year-old, intact female basset hound is presented. Malignant mesenchymomas are rare neoplasms in humans and in dogs. No previous reports of a malignant mesenchymoma with vasoinvasive metastasis in the dog were found in the literature. The constituent neoplasms are discussed in relation to reports in the human and veterinary literature, and a potential etiology for this unique presentation is hypothesized.