Trace and non-trace elements in blood cells of bottlenose dolphins (Tursiops truncatus): variations with values from liver function indicators.

Alterations in trace and non-trace element homeostasis have been associated with both normal physiologic and pathologic processes of many species. Changes in copper and zinc, for instance, have been associated with liver disease in humans and dogs. While liver disease has been documented in marine mammals, associations of liver disease with trace and non-trace elements have not been determined. The goal of this study was to assess potential elemental associations with clinically relevant changes in liver enzymes of bottlenose dolphins (Tursiops truncatus) and to compare observed associations to what has been reported in other species. Blood cell samples were collected from 37 healthy bottlenose dolphins, maintained by the Navy Marine Mammal Program (MMP), between 1991 and 1992. Twenty-one trace and non-trace elements were assessed along with a standard liver enzyme function profile, and trace element associations to specific liver enzymes were determined. In this study, of the 21 blood cell elements assessed, 19 were measured within detectable limits in at least one of the blood samples, and 10 trace elements were found to be associated with at least one of the liver function indicators. Many of these same associations have been documented in various forms of liver disease in other species, including the associations of increases in copper and decreases in zinc with both elevated alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT). The observed analogous associations between changes in blood trace and non-trace elements and liver function indicators of bottlenose dolphins and other species may indicate similar pathologic processes and functions of some elements. Given the results of this study, additional research is warranted to further elucidate associations of trace and non-trace elements to liver disease in bottlenose dolphins.

Isolation, characterization, and expression of stromelysin-1 in primary tumors of dogs.

OBJECTIVE: To isolate and characterize the cDNA sequence of canine stromelysin-1 (matrix metalloproteinase [MMPI-3), screen various naturally developing primary tumors of dogs, and assess the effect of stromelysin-1 on survival of dogs with cancer. SAMPLE POPULATION: 3 canine cell lines and biopsy specimens of primary tumors collected from 54 dogs. PROCEDURE: 3 canine cell lines and biopsy specimens of primary tumors collected from 54 dogs at the University of Illinois Veterinary Teaching Hospital were used in the study. Primer sets based on human stromelysin-1 and consensus sequences were designed for expression, screening, and isolation. Two additional primer sets were designed for screening. Samples were assayed at least in duplicate. Data were analyzed for differences in expression of stromelysin-1 on the basis of sex, age, metastasis, malignant versus nonmalignant tissue origin, and duration of patient survival. RESULTS: A 1,479-bp cDNA nucleotide sequence was amplified from established canine cell lines. The open reading frame encoded a protein consisting of 478 amino acids. This sequence was 70% to 88% homologous with stromelysin-1 of other species at the amino acid level. Fifty-four samples were screened for stromelysin-1. Of these, 34 (63%) had positive results and 20 (37%) had negative results for expression. Stromelysin-1 and metastasis were associated with a poor prognosis for survival. CONCLUSIONS AND CLINICAL RELEVANCE: Stromelysin-1 is a potential activator of other members of the MMP family. Additional studies are needed to investigate the relationship between stromelysin-1 production and aggressive biological behavior of tumors in dogs.

Modulation of the genotoxicity of pesticides reacted with redox-modified smectite clay.

Pesticides are toxic agents intentionally released into the environment; their use raises public health and environmental concerns. In recent years there has been much attention to the biotic degradation of pesticides. Abiotic mechanisms in the soil can contribute to pesticide degradation yet the toxicological impact of such degradation is unclear. This study combines for the first time an investigation into abiotic mechanisms of degradation coupled with toxicological endpoints in mammalian cells. The genotoxicity of three commonly used agricultural pesticides was assessed before and after exposure to redox-modified clay minerals. The objectives of the study were to determine the genotoxicity of 2,4-dichlorophenoxy acetic acid (2,4-D), dicamba, and oxamyl, using single cell gel electrophoresis with Chinese hamster ovary (CHO) cells, and to determine the effect of the iron oxidation state in clay minerals (ferruginous smectite SWa-1) on the genotoxic potency of the pesticides. 2,4-D alone or following reaction with redox-modified clays did not induce DNA damage in CHO cells. Oxamyl alone induced a concentration-dependent increase in genomic DNA damage; however, its genotoxicity declined after reaction with reduced clay minerals. Dicamba was not genotoxic when directly analyzed. When dicamba was reacted with reduced clay, a concentration-dependent increase in genomic DNA damage was observed. This is the first reported case of a pesticide being converted into a genotoxin after exposure to redox-modified smectites. These data introduce a new paradigm on the interaction between redox-modified clays and pesticide-related environmental genotoxicity.

Alteration of mammalian-cell toxicity of pesticides by structural iron(II) in ferruginous smectite.

The ultimate concern over pesticides in the environment is their toxic impact on nontarget organisms, including humans. Soil clays are known to interact with pesticides in ways that decrease the concentration of the parent compound in the soil solution (adsorption, sequestration, degradation). These phenomena are generally regarded as beneficial, but toxicological verification is lacking. In this study, mammalian-cell cytotoxicity of four commonly used agricultural chemicals (2,4-D, alachlor, dicamba, and oxamyl) was assessed after exposure to either reduced or oxidized ferruginous smectite (SWa-1). Results revealed that treatment with reduced smectite produced differential effects on mammalian-cell viability, depending on the pesticide. Oxamyl and alachlor reacted with reduced SWa-1 showed a significant decrease in their overall cytotoxic potential. Dicamba reacted with the reduced-clay treatment and generated products that were more toxic than the parent pesticide. Finally, no differences were observed between redox treatments for 2,4-D. The significance of these results is that oxidized smectites have virtually no influence on the toxicity of pesticides, whereas reduced-Fe smectite plays an important role in altering the cytotoxic potential of agricultural pesticides. The Fe oxidation state of clay minerals should, therefore, be taken into account in pesticide management programs.

Expression of matrix metalloproteinases in feline vaccine site-associated sarcomas.

OBJECTIVES: To screen for expression of 9 predominant members of the matrix metalloproteinase (MMP) family, including membrane-type matrix metalloproteinases (MT-MMPs) and tissue inhibitors of metalloproteinases (TIMPs), in primary tumor tissue biopsy specimens of vaccine site-associated sarcomas (VSS) in cats and compare expression profiles of VSS with expression profiles of non-VSS and carcinomas. SAMPLE POPULATION: 31 primary tumor tissue biopsy specimens and 6 nontumor (normal) tissue biopsy specimens. PROCEDURES: Tissue specimens were obtained from primary tumor biopsy specimens of cats. Primers for reverse transcriptase-polymerase chain reaction assay were designed on the basis of known sequences. Data were analyzed for patterns of expression of MMPs, MT-MMPs, and TIMPs. Differences in expression patterns were evaluated among cats of differing genders, ages, metastasis status, and overall survival durations, and between cats with VSS and cats with non-VSS tumor types. RESULTS: A total of 31 primary tumor tissue biopsy specimens and 6 nontumor (normal) tissue biopsy specimens were screened for the presence of 6 MMPs and 3 TIMPs. Matrix metalloproteinase and TIMP expression was found in non-VSS, carcinomas, and VSS. No significant differences were found in patterns of expression among tumor types. Metastasis was found to be the only predictive factor for overall survival duration. A significant correlation was found between MMP2 and MT-MMP16 expression and overall duration of survival. CONCLUSIONS AND CLINICAL RELEVANCE: The identification of MMPs in feline VSS supports an underlying inflammatory pathogenesis for this tumor. Expression of MMP2 and MT-MMP16 were correlated with survival time in our study.

Isolation, characterization, and expression of feline stromelysin-1 in naturally developing tumors in cats.

OBJECTIVE: To detect, isolate, and characterize feline stromelysin-1 (ie, matrix metalloproteinase [MMP]-3) in naturally developing tumors in cats. SAMPLE POPULATION: 31 tissue samples obtained from primary tumors and 6 samples of normal tissues from cats. PROCEDURE: Biopsy specimens were obtained from primary tumors. Primers were designed on the basis of known sequences. The sequence of stromelysin-1 was cloned and analyzed. An additional primer set was used as a screening tool. Samples were assayed in duplicate or triplicate, when possible. Data obtained were analyzed for differences in expression of stromelysin-1 with regard to overall survival among cats of various sex, age, and disease status. RESULTS: A 1,181-bp cDNA nucleotide sequence was amplified. The open reading frame encoded 393 amino acids. This amino acid sequence shared 70% to 85% sequence homology with sequences of other species. In addition, samples were screened for stromelysin-1. Of the 31 tumor samples tested, 16 (51.6%) had positive results for expression of stromelysin-1. Total RNA expression was detected in a diverse group of tumor types. Prognostic factors associated with a shorter duration of survival included evidence of metastasis and metastasis associated with expression of stromelysin-1. CONCLUSIONS AND CLINICAL RELEVANCE: Feline stromelysin-1 contains all the conserved regions typically found in members of the MMP family. Activity of stromelysin-1 has been implicated in a wide number of physiologic and pathologic processes. Identification of this gene may lead to the development of useful reagents to assist with diagnosis and management of neoplastic diseases in cats.