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PubMed1994

Use of a conductance catheter to assess the effect of endotoxemia on left ventricular end-systolic pressure-volume relationships in anesthetized swine.

Effects of endotoxemia on left ventricular contractility and systemic hemodynamics were determined in pentobarbital-anesthetized swine. A multielectrode conductance (volume) catheter and a high-fidelity pressure transducer catheter were passed retrograde into the left ventricle to continuously measure pressure and volume. End-systolic pressure-volume relationships were determined during transient (8 to 10 s) caudal vena caval balloon occlusion. Lactated Ringer's solution was administered at a rate sufficient to maintain left ventricular end-diastolic pressure > or = 6 mm of Hg. Following baseline measurements, Escherichia coli endotoxin (O55-B5) was infused IV at 2.5 micrograms/kg of body weight/h for 3 hours. Left ventricular end-systolic elastance (Ees), the slope of the end-systolic pressure-volume relationship; end-systolic elastance normalized for left ventricular end-diastolic volume (Ees norm); the rate of increase of left ventricular pressure (dP/dt max); and preload recruitable stroke work (PRSW, stroke work-to-end-diastolic volume relationship) did not change in endotoxemic swine, compared with baseline measurements or with values from control (physiologic saline solution-treated) swine. Left ventricular pressures and volumes had marked pig-to-pig variability in the control and endotoxin-treated groups. Determination of Ees, Ees norm, and PRSW was further confounded by development of frequent premature ventricular contractions during caudal vena caval balloon occlusion. Endotoxin significantly (P < 0.05) decreased left ventricular end-diastolic pressure, compared with that in control swine, and significantly (P < 0.01) decreased left ventricular end-diastolic volume, compared with baseline. Endotoxin decreased cardiac index and arterial blood pressure, whereas heart rate, central venous pressure, and mean pulmonary arterial pressure increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Prophylactic treatment of swine with bretylium for experimental cardiac catheterization.

We evaluated a cryothermic ablation catheter for potential use in treating supraventricular tachycardia by cardiac catheterization in miniature swine. Cardiac catheterization was performed on anesthetized miniature swine by using multiple catheters that were inserted bilaterally by either percutaneous or cutdown techniques into the femoral veins. We performed electrophysiologic tests according to standard atrial and ventricular electrical stimulation protocols. Manipulation of catheters in the tricuspid valve area and right ventricle was an essential part of the study. During an initial study of five swine, catheter manipulation produced sustained and nonsustained ventricular tachycardia and ventricular fibrillation. To prevent arrhythmias, bretylium (5 mg/kg) was administered intravenously 10 minutes before catheter manipulation and repeated every 30 minutes throughout the procedure. Since the use of bretylium was instituted, there have been no cases of ventricular fibrillation in a series of 20 animals. We determined that bretylium is effective in the suppression of ventricular arrhythmias in swine undergoing cardiac catheterization.

Animals↗
PubMed1993

Retrovirus-mediated transfer and expression of an allogeneic major histocompatibility complex class II DRB cDNA in swine bone marrow cultures.

The possibility of inducing transplantation tolerance by somatic gene transfer is under investigation in our miniature swine model. As a crucial step in this project, we have used a retroviral vector engineered to express both a drug-resistance gene (Neo) and a swine class II DRB cDNA to transduce porcine bone marrow (BM) cells. Analysis of cultured swine fibroblasts exposed to high-titer viral supernatants demonstrated that drug resistance had been conferred and that transferred vector sequences were transcribed appropriately. Similar transduction studies with swine BM demonstrated the transfer of drug resistance to as high as 14% of colony-forming unit-granulocyte-macrophage (CFU-GM). Using polymerase chain reaction (PCR) of cDNA, vector-derived allogeneic DRB transcripts were detected in colonies derived from primitive CFU-Mix and high proliferative potential-colony-forming cell (HPP-CFC), as well as in drug-resistant GM colonies grown from transduced bone marrow (BM) maintained in long-term BM cultures (LTBMCs) for up to 5 weeks. These results indicate that a significant proportion of both colony-forming progenitors and LTBMC-initiating cells were transduced with the DRB-recombinant retroviral vector and that both vector-derived genes were expressed in the differentiated progeny of these cells.

Animals↗
PubMed1993

[The effect of husbandry, management and stall climate on lung changes in swine].

21 swine fattening units (17 closed and 4 open swine herds), their pigs suffering from chronic respiratory disease since a long time were investigated concerning fattening period, morbidity, mortality, lung lesions by slaughtered swine, microorganisms involved, husbandry and management conditions, stall climate (indoor temperature, relative air humidity, contents of NH3, CO2, H2S, air microorganisms and dust). We estimated annual fattening periods of 137.4 +/- 6.8 days, morbidity of 49.1 +/- 12.2% and mortality of 6.8 +/- 3.7%. About 55-96% of lungs of slaughtered pigs showed pneumonic lesions in different degrees. Bacteriological examination of such lesions revealed up to 9 and not less than 3 different bacteria species per unit. Continuous producing systems were used by 19 units, only 2 units were managed by all in all out system. Pigs of 70 kg weight have air spaces of 1.7-3.1 m3, indoor temperature were between 21-26 C degrees and relative air humidity between 83.9 +/- 13.7%. Concentration of NH3 was found between 3-35 ppm, of CO2 between 500-3500 ppm, the numerical content of bacteria was within 900-1620 cfu (colony forming units) and of fungi between 2-80 cfu per litre air. There were also E. coli with and without haemolysis, Klebsiella pneumoniae, beta-haemolyzing streptococci and staphylococci in stall air. 2 swine houses gave 3-5, 15 houses 12-50 and 4 houses more than 50 cfu/cm2 blood agar plates exposed for 1 minute to the stable air (sedimentation method to judge stall dust). Animals of the later mentioned 4 houses showed the highest incidence of respiratory disorders (> 50% of pigs).(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollution, Indoor↗
PubMed1997

Exposure of swine to Trichinella spiralis antigen as determined by consecutive ELISAs and western blot.

Exposure of swine to Trichinella spiralis was evaluated using a combination of 3 consecutive enzyme-linked immunosorbent assays (ELISAs) based on larval T. spiralis excretory-secretory antigen as screening test and western blot analysis as confirmatory test. Ninety-three of 32,693 domestic swine sera collected in Georgia over a 5-yr period contained antibodies specific to T. spiralis (prevalence of exposure = 0.28%). The highest prevalence (0.52%) of exposure to T. spiralis was in samples from stockyards and salebarns. Prevalence of exposure in samples from cull sows from 1 slaughter house was 0.38% compared with 0.17% in samples obtained from farms. Pepsin-HCl digestion of diaphragms from 49 swine from 6 seropositive farms revealed 0.01 larvae/g in 4 swine from 3 farms. Determination of T. spiralis infection status of farms appears to be accurately determined with this combination of exploratory ELISAs and confirmatory western blot analysis.

Animals↗
PubMed1996

Longitudinal evaluation of dose-response relationships for environmental exposures and pulmonary function in swine production workers.

Studies describing respiratory health hazards for workers in swine production facilities have been published in the United States, Sweden, Canada, the Netherlands, and Denmark. Up to 50% of these workers experience bronchitis, organic dust toxic syndrome, hyper-reactive airways disease, chronic mucous membrane irritation, and other respiratory effects. These studies clearly point to the fact that this occupational environment poses a significant health risk hazard, and that control methods are needed to protect the worker. Before precise control strategies can be developed, implemented, and evaluated, dose-response studies are required to determine acceptable target levels for exposure. A previous manuscript described the development of multiple regression equations characterizing the relationships between environmental exposures and pulmonary response in a cohort of 207 swine producers. Baseline pulmonary function was included as a significant predictor of cross-shift decrements in pulmonary function in addition to personal measurements of dust, endotoxin, and ammonia concentrations. These equations were then used to predict specific exposure levels of dust and ammonia that could be expected to elicit significant decrements in cross-shift pulmonary function. This paper presents the results from analysis of follow-up data obtained on this same cohort 2 years after the initial measurements. At the second measurement period of the study (time-2), swine workers were found to have a mean cross-shift decrease in FEV1 of 2%. Cross-shift change in FEV1 was significantly correlated with personal exposures to total dust, total endotoxin, respirable endotoxin, and ammonia. The magnitude of the decrease in FEV1 was associated with increasing airborne concentrations of these environmental parameters thus confirming the dose-response relationship observed in the initial study (time-1). The correlation of dust with FEV1 changes in workers with more than 6 years of exposure (time-1 data) and more than 10 years of exposure (time-2 data) suggests that dust exposure is an important factor in chronic respiratory disease. Additionally, the correlation of endotoxins with FEV1 changes in the group with less than 6 years exposure (time-2 data) suggests endotoxins may have more significance for subacute respiratory effects. The agreement between observed cross-shift FEV1 changes measured in time-2 with changes predicted using regression equations derived from time-1 data demonstrates a consistent dose-response relationship over time for this cohort of swine production workers. This finding provides further support for conclusions of the previous study that levels of 2.5 mg/m3 (total dust) and 7.5 ppm (ammonia) are reasonable guidelines for occupational exposure limits in this environment.

Adult↗
PubMed1979

Crystalloids of actin-like filaments in the Sertoli cell of the swine testis.

Normal swine testes, congenital cryptorchid swine testes, and normal human tests were exposed to HMM (heavy meromyosin) after either glycerination or saponin treatment in order to determine whether the fine filaments composing the crystalloids in the Sertoli cells of the cryptorchid swine testes bind HMM to form arrowhead complexes. Short bundles of microfilaments observed in the basal part of the Sertoli cells in both normal and cryptorchid testes also bind HMM. Similar bundles of HMM-bound filaments are observed in the vicinity of spermatocytes. The periodicity of the arrowhead complexes is about 35 nm, and all arrowheads on a given filament point in the same direction. In addition, the polarity of the HMM-bound filaments in a given crystalloid or bundle is uni-directional. A mechanism for the formation of the swine crystalloids has been strongly support this hypothesis. Fine filaments of Charcot-Boettcher's crystalloid in human Sertoli cells did not bind HMM. Therefore the fine filaments of the human crystalloid are not actin-like in nature.

Actins↗
PubMed1986

Swine chromosomes: flow sorting and spot blot hybridization.

Flow cytometry analysis was applied to swine chromosomes prepared from phytohemagglutinin (PHA) stimulated peripheral blood lymphocytes. Flow karyotypes from both sexes and from t(3;7) translocation carrier females were obtained. A certain number of chromosome pairs could be assigned to various peaks. In fact, 13 peaks were observed for 18 autosomal pairs plus X and Y. Moreover, abnormalities owing to the t(3;7) translocation were readily observable. The number of base pairs for chromosomes associated with the various peaks was estimated by comparison with human flow karyotypes. The following four peaks were thus sorted: the peak assumed to represent the translocated chromosome 7 plus the normals associated with it; the corresponding peak from a normal swine; the peak assumed to contain among others the normal chromosome 7; and finally the peak corresponding to swine chromosome 1. Chromosomes of each peak were collected on Pall Biodyne membrane. Following appropriate denaturation and prehybridization, the four samples were hybridized with a human leucocyte antigen (HLA) class I 32P-labelled cDNA probe, representing most of the coding sequence of the HLA B7 gene. The results confirmed previous data from other techniques that assigned the swine MHC(SLA) to chromosome 7. Subsequently, sorted samples were hybridized with a porcine genomic Interferon alpha probe in order to confirm the mapping of this gene family on porcine chromosome 1.

Animals↗
PubMed2004

Identification of five chromosomal regions involved in predisposition to melanoma by genome-wide scan in the MeLiM swine model.

In human familial melanoma, 3 risk susceptibility genes are already known, CDKN2A, CDK4 and MC1R. However, various observations suggest that other melanoma susceptibility genes have not yet been identified. To search for new susceptibility loci, we used the MeLiM swine as an animal model of hereditary melanoma to perform a genome scan for linkage to melanoma. Founders of the affected MeLiM stock were crossed with each other and with healthy Duroc pigs, generating MeLiM, F1 and backcross families. As we had previously excluded the MeLiM CDKN2A gene, we paid special attention to CDK4 and MC1R, as well as to other candidates such as BRAF and the SLA complex, mapping them on the swine radiation hybrid map and/or isolating close microsatellite markers to introduce them into the genome scan. The results revealed, first, that swine melanoma was inherited as an autosomal dominant trait with incomplete penetrance, preferably in black animals. Second, 4 chromosomal regions potentially involved in melanoma susceptibility were identified on Sus Scrofa chromosomes (SSC) 1, 2, 7 and 8, respectively, in intervals 44-103, 1.9-18, 59-73 and 47-62 cM. A fifth region close to MC1R was revealed on SSC 6 by analyzing an individual marker located at position 7.5 cM. Lastly, CDK4 and BRAF were unlikely to be melanoma susceptibility genes in the MeLiM swine model. The 3 regions on SSC 1, 6 and 7, respectively, have counterparts on human chromosomes (HSA) 9p, 16q and 6p, harboring melanoma candidate loci. The 2 others, on SSC 2 and 8, have counterparts on HSA 11 and 4, which might therefore be of interest for human studies.

Animals↗
PubMedDate not supplied

Effects of zearalenone and/or tamoxifen on swine and mink reproduction.

Tamoxifen (TAM), which binds to estrogen receptors and can act as an estrogen antagonist, was incorporated into the diets of swine and mink to determine if it would ameliorate the effects of the estrogenic mycotoxin zearalenone (ZEN). Sows and female mink were fed diets containing 2 ppm (swine) or 20 ppm (mink) ZEN and/or 10 ppm TAM from day 30 of gestation through weaning (swine) or from 2 months prior to breeding through weaning (mink). The diets containing ZEN and/or TAM did not adversely affect reproduction in the sows. Although some hyperestrogenic effects on testes, uterine and ovarian weights were observed in the F1 piglets at 21 days of age, subsequent breeding performance was not affected. All the female mink exposed to ZEN mated, but only 25% whelped. No mink fed TAM (singly or in combination with ZEN) mated. Necropsy of these unmated females fed TAM revealed consistent severe pyometra. Histological examination of the reproductive tracts of the ZEN, TAM and ZEN + TAM-treated mink showed similar alterations, including ovarian follicular atrophy and degeneration, and mild to severe uterine atrophy, pyometra and endometritis. The results of these studies indicate that TAM was not effective in ameliorating the hyperestrogenic effects of ZEN in swine and mink, but rather it acted as an estrogen agonist.

Animals↗
PubMed1996

Constitutive expression of HSP 72 in swine heart.

Stress-induced regulation of the 72 kD heat shock protein (HSP 72), the major stress inducible protein in mammalian cells, is mediated by the activation and binding of a heat shock transcription factor (HSF) to a specific sequence in the 5' region of the promoter termed the heat shock element (HSE). In agreement with this regulation, HSP 72 is absent in most cells under unstressed conditions but is rapidly synthesized following exposure to protein damaging stressors. An exception is the skeletal muscle, where HSP 72 is constitutively expressed in muscles that express the beta myosin heavy chain (beta-MHC) protein. Since beta-MHC is also expressed in the ventricles of large mammals, we have examined if HSP 72 was also constitutively expressed in beta-MHC positive hearts. Chambers of the heart muscle from Yorkshire swine were examined for alpha-MHC, beta-MHC and HSP 72 content. HSF:HSE activation was also assessed by gel shift analyses. In the swine heart, atria and ventricles differed in their alpha-MHC and beta-MHC protein content but all expressed a high HSP 72 content. Gel shift analyses demonstrated no HSF:HSE binding in extracts from unstressed swine hearts. These results indicate that HSP 72 is constitutively expressed in all portions of the swine heart and this expression may not be dependent on an HSF:HSE interaction.

Animals↗
PubMed1991

Subunit structure of deglycosylated human and swine trachea and Cowper's gland mucin glycoproteins.

The oligosaccharide chains in human and swine trachea and Cowper's gland mucin glycoproteins were completely removed in order to examine the subunit structure and properties of the polypeptide chains of these glycoproteins. The carbohydrate, which constitutes more than 70% of these glycoproteins, was removed by two treatments with trifluoromethanesulfonic acid for 3 h at 3 degrees and periodate oxidation by a modified Smith degradation. All of the sialic acid, fucose, galactose, N-acetylglucosamine and N-acetylgalactosamine present in these glycoproteins was removed by these procedures. The deglycosylated polypeptide chains were purified and characterized. The size of the monomeric forms of all three polypeptide chains were very similar. Data obtained by gel filtration, release of amino acids during hydrolysis with carboxypeptidase B and gel electrophoresis in the presence of 0.1% dodecyl sulfate showed that a major fraction from each of the three mucin glycoproteins had a molecular size of about 67 kDa. All of the deglycosylated chains had a tendency to aggregate. Digestion with carboxypeptidases showed that human and swine trachea mucin glycoproteins had identical carboxyl terminal sequences, -Val-Ala-Phe-Tyr-Leu-Lys-Arg-COOH. Cowper's gland mucin glycoprotein had a similar carboxyl terminal sequence, -Val-Ala-Tyr-Leu-Phe-Arg-Arg-COOH. The yield of amino acids after long periods of hydrolysis with carboxypeptidases showed that at least 85% of the polypeptide chains in each of the deglycosylated preparations have these sequences. These results suggested that the polypeptide chains in these deglycosylated mucin glycoprotein preparations were relatively homogeneous. The deglycosylated polypeptide chains as well as the intact mucin glycoproteins had blocked amino terminii. The purified polypeptide chains were digested with trypsin-TCPK, and S. aureus V8 protease and the resulting peptides were isolated by gel electrophoresis in the presence of 0.1% dodecyl sulfate and by HPLC. Two partial amino acid sequences from swine trachea mucin glycoprotein, two partial sequences from human trachea mucin glycoprotein and three partial sequences from Cowper's gland mucin glycoprotein were determined. The partial amino acid sequences of the peptides isolated from swine trachea mucin glycoprotein showed more than 70% sequence homology to a repeating sequence present in porcine submaxillary mucin glycoprotein. Five to eight immunoprecipitable bands with sizes ranging from about 40 kDa to 46 kDa were seen when the polypeptide chains were digested with S. aureus V8 protease. All of the bands had blocked amino terminii and differed by a constant molecular weight of about 1.5 kDa.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1991

Penicillium verrucosum in feed of ochratoxin A positive swine herds.

Ochratoxin A contamination of cereal feed grain was monitored during October 1989-September 1990 by analysis of blood samples from slaughter swine in Sweden. The detection of ochratoxin A in swine blood was used as a method to identify swine herds fed ochratoxin A contaminated feed. The contamination level of ochratoxin A in the blood of the positive herds was in the range 2-45 ng/ml with the mean concentration 5.2 ng/ml. Feed samples for mycological analysis were collected from both ochratoxin A positive herds (greater than or equal to ng/ml blood) and ochratoxin A negative herds (less than 2 ng/ml blood). From the ochratoxin A positive herds and the ochratoxin A negative herds 22 and 21 feed samples were collected, respectively. No quantitative differences in mould content, as determined by colony forming units, were observed between the two groups. However, there were differences in the mycoflora. The incidence of storage fungi (Penicillium and Aspergillus spp.) was significantly higher (p less than 0.05) in feed from ochratoxin A positive herds. Particularly, Penicillium verrucosum was found to be significantly more common (p less than 0.001). Altogether 274 isolates were screened for their ability to produce ochratoxin A. Ochratoxin A producers were found only within P. verrucosum; 38% of the 63 isolates produced detectable amounts of ochratoxin A. Ochratoxin A producing isolates of P. verrucosum were found in 60% of the feed samples collected from ochratoxin A positive swine herds and in one sample (5%) of the feed samples collected from the ochratoxin A negative herds.

Animal Feed↗
PubMed1992

Characterization of fumonisin toxicity in orally and intravenously dosed swine.

Fumonisin B1 (FB1), a recently identified mycotoxin produced by Fusarium moniliforme in corn, has been shown to cause death in swine due to pulmonary edema, an apparently species specific effect, and to interfere with sphingolipid metabolism in vitro. Here we characterize the toxicity of fumonisins, using female cross-bred swine weighing 6 to 13 kg, and present a hypothesis regarding the mechanism of fumonisin-induced pulmonary edema in swine. FB1 was given daily intravenously (IV) to pig 1 for 9 days for a total of 72 mg (7.9 mg/kg) and to pig 2 for 4 days for a total of 67 mg (4.6 mg/kg). Pig 3 (control) was given saline IV for 9 days. Corn screenings naturally contaminated with FB1 (166 ppm) and FB2 (48 ppm) were fed to pigs 4, 5, and 6, and ground corn was fed to pigs 7 and 8 (controls). Pigs 4 and 7 were killed on day 5; pig 5 was found dead on day 6; and pigs 6 and 8 were killed on day 15. Pigs 4 and 5 had ingested 187 and 176 mg total fumonisins, respectively, while pig 6 had ingested 645 mg. Feed consumption had decreased in pigs fed corn screenings, with an additional sharp decrease prior to onset of clinical signs. Increases in serum liver enzymes, total bilirubin, and cholesterol were present, but electrocardiograms, heart rate, and body temperature were unaffected. Pigs dosed IV with FB1, developed mild intermittent respiratory abnormalities, while those fed screenings developed respiratory distress within 5 days. Mild interstitial pulmonary edema was observed in pig 1. Severe interstitial pulmonary edema, pleural effusion, and increased lung wet/dry weight ratio were observed in pigs 4 and 5. All pigs given fumonisin (either IV or orally) had hepatic changes characterized by hepatocyte disorganization and necrosis; pancreatic acinar cell degeneration was also observed. Ultrastructural changes in orally dosed swine included loss of sinusoidal hepatocyte microvilli; membranous material in hepatic sinusoids; and multilamellar bodies in hepatocytes, Kupffer cells, pancreatic acinar cells and pulmonary macrophages. Pulmonary intravascular macrophages (PIMs) contained large amounts of membranous material. Thus, the target organs of fumonisin in the pig are the lung, liver, and pancreas. At lower doses, slowly progressive hepatic disease is the most prominent feature, while at higher doses, acute pulmonary edema is superimposed on hepatic injury and may cause death. We hypothesize that altered sphingolipid metabolism causes hepatocellular damage resulting in release of membranous material into the circulation.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗
PubMed1985

Characterization of a 1980-swine recombinant influenza virus possessing H1 hemagglutinin and N2 neuraminidase similar to that of the earliest Hong Kong (H3N2) virus.

A recombinant (H1N2, formerly Hsw 1N2), A/swine/Ehime/1/80 was found to possess antigenic, biological and genomic characteristics different from those of a previous A/swine/Kanagawa/2/78 (H1N2) strain. Five monoclonal antibodies to A/NJ/8/76 definitely differentiated the hemagglutinin molecules of the former virus from the latter, showing that these viruses differed, at least, at two antigenic determinants. Neuraminidase-inhibition tests with monoclonal antibodies to different H2N2 and H3N2 viruses revealed that the A/swine/Ehime/1/80 strain contained a neuraminidase very similar to that of the late human Asian (H2N2) and the earliest Hong Kong (H3N2) viruses. Growth comparison of swine and human isolates indicated that A/swine/Ehime/1/80 and A/swine/Shizuoka/1/78 (H1N1) failed to grow at 42 degrees C, while A/swine/Kanagawa/2/78 and its possible parental virus, A/swine/Kanagawa/4/78 (H1N1) replicated efficiently at this stringent temperature. These results revealed that the viruses having growth characteristics similar to those of avian influenza virus were present in the swine population. RNA analysis by oligonucleotide mapping suggested that A/swine/Ehime/1/80 may be a recombinant between A/swine/Shizuoka/1/78-like and A/Aichi/2/68 (H3N2)-like viruses. To further determine the gene constellation of this recombinant virus, DNA-RNA hybridization was performed by using DNA segments complementary for swine (H1N1) virus RNA and the entire RNAs of three viruses. The molecular hybridization could define the genomic composition of the recombinant, indicating that only the neuraminidase gene of this virus is derived from the earliest Hong Kong (H3N2)-like virus and remaining seven genes from swine (H1N1) virus.

Animals↗
PubMed1990

Establishment of transformed swine fibroblast cell lines using SV40 large T antigen.

Swine testicle cell lines were established by transformation of primary swine testicle (PST) cells with an SV40 plasmid (pSV3-neo), which contains genes conferring resistance to neomycin and expressing SV40 large T antigen. Plasmid DNA was transfected into PST cells using a lipofection system. Two related plasmids, pSV2-neo and pSV5-neo, failed to induce transformed cells. Cells transformed with pSV3-neo formed single colonies that were resistant to the antibiotic, G418, and expressed large T antigen. Upon two cycles of cloning by endpoint dilution method, three transformed clones, designated transformed swine testicle (tST)-3, tST-14 and tST-18, were selected and characterized in regards to cell replication and susceptibility to swine viruses. The resultant clones were compared with a counterpart non-transformed ST cell line (ATCC-ST). The three tST cell lines showed longer or the same doubling times and higher saturation densities compared to ATCC-ST cells. These cells were free from a range of adventitious agents and supported the replication of porcine parvovirus (PPV), pseudorabies virus (PRV) and transmissible gastroenteritis virus (TGEV), comparable to ATCC-ST cells. All three cell lines have been maintained in continuous cultures for over 60 passages with no changes in growth characteristics. These findings indicate that lipofection with pSV3-neo is an efficient means for the introduction of exogenous DNA into porcine cells and for establishment of transformed immortalized cell lines.

Animals↗
PubMed1983

Antigenic and genetic characterization of H1 influenza viruses isolated from feral ducks and swine in Japan.

The strains of H 1 N 4 influenza A virus isolated from feral ducks in Japan in 1977-78 were compared to swine-origin H 1 N 1 viruses antigenically and genetically. Homologous characteristics were found among the H 1 N 4 isolates from feral ducks in hemagglutination-inhibition (HI) tests, viral RNA patterns on polyacrylamide gel electrophoresis and oligonucleotide mapping. Although the hemagglutinins of duck-origin viruses employed in this study were identified as H 1, the viruses were distinguishable from A/New Jersey/8/76 (H 1 N 1), A/duck/Alberta/35/76 (H 1 N 1) and the virus isolated from swine in Japan in the cross HI test. Also, the viral RNA patterns of the duck- and swine-origin H 1 viruses were found to be quite different, indicating that genetic reassortment of HA genes between them is unlikely. After H 1 N 4 virus of duck-origin was intranasally inoculated into pigs, a brief period of virus recovery with no serological response was observed; whereas swine-origin H 1 N 1 virus produced seroconversion in the pigs inoculated.

Animals↗
PubMed1979

Comparative studies on cell lines established from normal and radiation-exposed miniature swine.

Cloned cell lines were established from two swine with radiation-induced myeloproliferative disorders, including one cell culture from an animal with myelogenous leukemia and one from an animal with myeloid metaplasia. A third cloned cell line with similar morphology was established from pooled normal fetal swine cornea to compare the growth characteristics of cells from normal and irradiated swine. All three cell lines grew as foci of aggregated cells and were able to form macroscopic colonies in semisolid agar medium. The lack of normal mechanisms of contact inhibition and the observed aneuploidy indicated that these cells were morphologically transformed. Further, the cloned cells caused tumors in nude mice, clearly indicating that these cells were also malignantly transformed. A major difference between these cell lines was that type C viruses were observed only in the cells derived from swine with myeloproliferative disorders.

Animals↗