Lance C. Buoen

Foreign body tumorigenesis.

This review deals with factors and mechanisms involved in sarcoma development upon implantation of chemically inert foreign bodies. The topic is of importance regarding cancer in asbestosis or schistosomiasis, and also in view of increasing ise of artificial implants. After detailing morphological and biological characteristics of foreign body-induced sarcomas in man and animals, the review focuses on specific properties of implants and experimental animals which determine or influence tumor incidence and latency. Included are surface properties, size and shape of implants, and species characteristics, sex, and genetic background of animals. It follows a description of recent etiologic research which has evealed foreign body tumorigenesis as a multistage developmental process. Some of the salient features are monoclonal forigin from mesenchymal stem cells of the micro-vasculature; origination of neoplastic destination and specific tumor leterminants in cells distant from the implant during the earliest st...

XY sex-reversal syndrome in the domestic horse

The XY sex-reversal syndrome occurs when a phenotypic mare is born that has the karyotype of a stallion. The syndrome is manifested by both genotypic and phenotypic heterogeneity. The sex-reversed genetic condition occurs frequently within certain pedigrees where XY females have been found and can be readily detected by chromosome karyotyping. The phenotypic spectrum ranges from the feminine mare with a reproductive tract that is within normal limits to the greatly masculinized mare. Pedigree analysis suggests that there are two modes of inheritance: (1) an X-linked recessive or autosomal sex-limited dominant transmitted through the female and (2) an autosomal sex-limited dominant or a Y chromosomal mutation with variable expression transmitted through the male. The proportion of female to male progeny of the 69 top-producing Arabian stallions in the world is 53 to 47, indicating that the occurrence of genetic defects affecting the sex ratio such as the XY sex-reversal syndrome is relatively infrequent. In nine cases where the sex ratios of stallions deviated significantly from the expected sex ratio, the incidence of female infertility also increased. Cytogenetic screening of young animals would provide for early detection and avoid the expense and disappointment of continuous breeding attempts. Just as importantly, it would aid in the reduction and the possible elimination of this genetic condition from breeding herds.

Idiopathic Hypereosinophilic Syndrome in 3 Rottweilers

Three Rottweilers with marked peripheral eosinophilia and infiltration of the liver, spleen, lungs, and bone marrow with eosinophils were diagnosed with idiopathic hypereosinophilic syndrome (IHES). Mean serum immunoglobulin E concentrations were markedly high. On cytogenetic analysis, no evidence of karyotypic abnormalities was found in bone marrow aspirates. Despite an extensive search, no underlying cause for the eosinophilia could be identified. In this study, cytogenetic analysis and measurement of serum IgE concentrations were used to differentiate IHES and eosinophilic leukemia.

Feline Mammary Sarcoma Composed of Cells Resembling Myofibroblasts

A recurrent mammary sarcoma from an 11-year-old, female domestic cat was studied by light and electron microscopy and immunohistochemistry. The tumor consisted of interlacing bands of spindle cells with elongated blunt-ended nuclei and variable amounts of stroma. Multinucleated tumor giant cells and mitoses were common. Ultrastructurally, tumor cells had abundant rough endoplasmic reticulum with dilated cisternae, a prominent Golgi complex, frequent mitochondria, bundles of intracytoplasmic filaments with focal densities, and discontinuous basal lamina-like material and cell junctions. These findings suggest that myofibroblast-like cells were the predominant type of tumor cell. Failure to demonstrate immunoreactivity for cytokeratins attested to the non-epithelial origin of these neoplastic cells. Uniform immunoreactivity with anti-vimentin antibodies and specific labelling of some tumor cells with antiserum to actin are compatible with an origin of this tumor from modified fibroblasts (i.e., myofibroblast-like cells). Tumors composed largely of myofibroblasts may be unique and warrant separate classification from other types of fibroblastic tumors in animals.

Comparison of cytogenetics and polymerase chain reaction based detection of the amelogenin gene polymorphism for the diagnosis of freemartinism in cattle

A polymerase chain reaction (PCR) assay which detects a sex-based polymorphism in the bovine amelogenin locus was modified and compared to conventional cytogenetic analysis for diagnosis of freemartinism (XX/XY chimerism) in cattle. The PCR assay is more sensitive than cytogenetic analysis for detection of XY cells, with the limit of detection of the assay falling between 0.2% and 1% XY cells. Seventy-three heifer blood samples submitted for evaluation of freemartinism to the University of Minnesota Diagnostic Laboratory were tested using both cytogenetic and PCR techniques. Poor-quality samples precluded successful lymphocyte culture and recovery of mitotic nuclei for cytogenetic evaluation in 17 cases (23%). Two of these samples (2.7%) also failed to amplify with PCR. There was 100% agreement in the results from the 56 samples that were suitable for testing using both techniques. This PCR-based assay provides an alternative to the more laborious cytogenetic evaluation for diagnosis of freemartinism.

X trisomy in an Airedale bitch with ovarian dysplasia and primary anestrus

A 79,XXX chromosome complement was detected in a four-year-old Airedale Terrier bitch examined for primary anestrus. Serum concentrations of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were markedly elevated. Ovaries contained solid epithelial cords and large masses of interstitial cells but lacked follicles and corpora lutea. Somatic abnormalities were not observed. X trisomy is reviewed in six species in which it has been described.

Development and use of a microdissected swine chromosome 6 DNA library

To facilitate the identification of microsatellite genetic markers from a single swine chromosome, chromosome microisolation and microcloning have been used to generate a swine chromosome 6-specific DNA library. Ten copies of swine chromosome 6 were scraped from metaphase spreads, ligated to custom-prepared adaptors, and amplified by PCR. The purity of the amplified product was verified by fluorescent in situ hybridization. The utility of the chromosome painting probe for heterologous painting was demonstrated and confirmed that swine chromosome 6 is syntenic to human chromosomes 1p and 19q. A small insert genomic library of 1.39 x 10(6) clones was generated from the PCR-amplified chromosome 6 genomic DNA and screened for (GT)n microsatellite genetic markers. Nine (GT)n microsatellite markers were developed and genotyped on a Yorkshire x Meishan swine reference family. All nine markers genetically mapped to chromosome 6, confirming the purity of the microisolation method. The method used here should be adaptable to the microdissection of subchromosomal regions of not only the swine genome but also other livestock genomes.

Malignant transformation and maturation in non-dividing cells during polymer tumorigenesis.

Summary It was confirmed that, during polymer solid surface carcinogenesis, pre-malignant cells reside on the plastic insert as early as eight months before tumor maturation. No premalignant cells were demonstrated in the surrounding tissue except for the very late stage of less than four weeks. During the premalignant period no mitotic activity or cellular turnover was observed among the cell population that presumably included the premalignant clone. Clearance of carbon particles was minimal. It was concluded that at least in this instance the entire process of premalignant development and maturation seems to take place in non-dividing cells.

Polymer Tumorigenesis Multiple Preneoplastic Clones in Priority Order with Clonal Inhibition

Summary Tumorigenesis was induced in CBA-mice by implanting plastic films. Each animal produced multiple karyologically distinct preneoplastic cell clones. These were separated by transferring preneoplastic cells or tissue in various ways to CBA-T6-recipients. It was concluded that one of the clones has neoplastic priority apparently by specifically inhibiting preneoplastic processes in secondary clones.

The Requirement of Fibroblasts to Confirm the Identity of Cytogenetic Centric Fusion (CF) Carriers in Same-Sex Twin Cattle

to demonstrate a tear or rupture. No evidence of thoracic trauma was found. The mucous membranes were pink, and there was no obvious pallor to the other body tissues. There were no other hemorrhages. No anticoagulant rodenticides were detected in the stomach contents or liver. Microscopic lesions were restricted to the tissue of the heart base and pericardium. Multiple lobules of thymic tissue were present at the heart base. There was depletion of lymphocytes and thinning of the cortex consistent with thymic invo1ution. Interlobular septa were markedly widened by hemorrhage (Fig. 1). This hemorrhage blended with hemorrhage infiltrating the wall of the dorsal pericardium, adventitia of the great vessels, and adipose tissue located at the heart base. Blood vessels in the medulla were heavily congested. Hemorrhages obscured the medulla of several lobules (Fig. 2).