SEARCH · PubMed Health

Results for “Pigs”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed1992

Gastrin metabolism in neonatal pigs and grower-pigs.

1. Half-life (1.7 +/- 0.1 min), distribution volume (146 +/- 12 ml/kg) and metabolic clearance rate (28 +/- 1 ml/kg/min) of little gastrin (G17) in neonatal pigs (N = 6; 3-12 days old) were significantly different from those in grower-pigs (N = 4; 161-170 days old) (2.4 +/- 0.1 min; 58 +/- 2 ml/kg; 7.9 +/- 0.3 ml/kg/min, respectively). 2. Half-life (33 +/- 4 min) and distribution volume (265 +/- 33 ml/kg) of big gastrin (G34) in neonatal pigs were greater but not significantly different from those in grower-pigs (24 +/- 2 min; 217 +/- 20 ml/kg, respectively). 3. Half-life of G17 in liver extracts from pigs 2-90 days old (40.4 +/- 4.2 min) was significantly longer than in kidney extracts (22.0 +/- 1.7 min). Half-lives of G34 in liver and kidney extracts from pigs 10-90 days old (78 +/- 6; 74 +/- 4 min, respectively) were significantly shorter than the corresponding values for 2-day-old pigs (134 +/- 3; 149 +/- 9 min, respectively). 4. Since G34 is the major circulating form of gastrin in neonatal pigs the relative longer half-life of G34 to G17 in these animals may contribute to the higher circulating gastrin concentration compared with that in older animals.

Animals↗

PubMed1998

Evidence of human non-alpha-galactosyl antibodies involved in the hyperacute rejection of pig lungs and their removal by pig organ perfusion.

BACKGROUND: Human natural xenoantibodies represent a major hurdle to the clinical application of pig lungs in transplantation by initiating hyperacute rejection within minutes to hours. OBJECTIVE: The object was to compare pig organ perfusion and specific depletion of anti-alpha-galactosyl xenoantibodies for prevention of hyperacute rejection in the pig to human lung combination. METHODS: Large White pig (20-25 kg) left lungs were removed and continuously ventilated and reperfused ex vivo either with (1) whole human blood previously perfused in situ through pig right lung (group I), liver (group II), or spleen (group III) or with (2) human plasma in vitro immunoabsorbed on columns containing alpha-galactosyl disaccharide (Gal-alpha-(1-3)Gal-beta-(CH2)3NH2; B disaccharide) (group IV). Each study group included 6 animals. RESULTS: The in situ and in vitro preperfusions depleted anti-alpha-galactosyl xenoantibodies and all in situ perfused pig organs showed histologic signs of hyperacute rejection. After the ex vivo reperfusion, group I xenografts had a significantly (P < .001) longer functional and histologic survival than did xenografts in groups II, III, and IV. Human blood reperfusing group I xenografts had a significantly (P < 0.05) lower (1) decline of clotting factors and total circulating immunoglobulins, (2) total and membrane attack complex (C5b,6,7,8,9) complement activation, and (3) hemolysis. By Western blot analysis, the in situ lung preperfusion removed antibodies against non-alpha-galactosyl proteins of low molecular weight that were not eliminated by the alpha-galactosyl column. CONCLUSIONS: Results demonstrate that specific depletion of anti-alpha-galactosyl antibodies alone incompletely protects pig lungs from hyperacute rejection. It is speculated that the more complete prevention of this rejection afforded by pig lung preperfusion relates to the removal of other, non-alpha-galactosyl antibodies.

Acute Disease↗

PubMed1999

Progression of Mycoplasma hyosynoviae infection in three pig herds. Development of tonsillar carrier state, arthritis and antibodies in serum and synovial fluid in pigs from birth to slaughter.

In this investigation, natural infection with Mycoplasma hyosynoviae was followed in groups of individual pigs in three different herds with regard to occurrence of tonsillar carrier state, clinical arthritis and development of antibodies in serum and in synovial fluid. Antibodies were detected by a polyclonal enzyme-linked immunosorbent assay (ELISA) developed for experimental use. The infection with M. hyosynoviae progressed very differently in the three herds investigated. In one herd, the infection was apparently limited to adult pigs. In a second herd, all pigs became tonsillar carriers of M. hyosynoviae, but no mycoplasma-related arthritis nor any serological response was demonstrated within the growing-finishing period. In the third herd investigated, tonsillar infection was detected in all pigs, clinical cases of M. hyosynoviae arthritis followed and a moderate serological response was observed in some, but not all, pigs. In all three herds, M. hyosynoviae infection was carried in the tonsils of the adult pigs, but it was only occasionally transmitted from sows to piglets. Maternal antibodies were transferred to the piglets and persisted for approximately 8-12 weeks. After weaning, some pigs became infected before 20 weeks of age, while others did not. In the majority of cases, the tonsillar infection was established from 11 weeks of age or older. A latent tonsillar infection was present for a period of several weeks within the group of investigated pigs before cases of generalized infection and arthritis were seen. In some cases, generalization of M. hyosynoviae infection in the blood and in joints was observed in spite of the detection of an active serological response a few weeks earlier. The present work suggests that generalization of the infection and development of arthritis may depend on age, immunity, virulence factors and/or infection pressure; in some herds maybe combined with certain triggering mechanisms such as stress and lowered general resistance.

Animals↗

PubMed1981

Digestion in the pig between 7 and 35 d of age. 5. The incorporation of amino acids absorbed in the small intestines into the empty-body gain of pigs given milk or soya-bean proteins.

1. In two separate experiments, forty-two pigs weaned at 4--5 d of age were given diets containing milk or soya-bean protein and slaughtered at 7, 28 or 35 d of age. 2. The amino acid composition of the empty body of the pigs did not vary with age or sources of protein fed. 3. The nitrogen and amino acid contents of the empty body gain were calculated between 7 and 28, and 7 and 35 d of age. The retention of absorbed N was greater in pigs given a soya-bean meal (SBM) diet than in pigs given milk or isolated soya-bean protein (ISP) diets. 4. The retention of total absorbed N was greater in pigs given a pelleted milk diet (0 .72) than in pigs given a liquid milk diet (0 . 58). 5. Methionine and threonine appeared to be the first two limiting amino acids, as indicated by their high incorporation into the empty body, for pigs given soya-bean proteins in Expt 3, while methionine and lysine were the first two limiting amino acids for pigs given ISP in Expt 4. 6. The addition of methionine to diets in Expt 3 reduced the retention of absorbed methionine in the empty body by 43--76%. Lysine supplementation did not alter the retention of the absorbed lysine. 7. Retention of arginine, proline and glycine in the body was greater than the apparent absorption of each of these amino acids.

Aging↗

PubMed1982

Artificial rearing of pigs. 12. Effect of replacement of dried skim-milk by either a soya-protein isolate or concentrate on the performance of the pigs and digestion of protein.

1. Pigs (sixteen/diet) were weaned at 2 d of age and given liquid diets (200 g dry matter/l) during a 26 d experiment. The pigs were fed on a scale based on live weight. Dried skim-milk was the only source of protein in diet U and was partially or totally replaced by a soya-bean isolate (diet B) or a concentrate (diets C and D). Soya-bean protein provided 500, 700 or 350 g/kg total crude protein (nitrogen x 6.25) in diets B, C and D respectively. 2. Performance was similar for diets B and D, but poorer than that of pigs given diet U. The apparent digestibility and retention of N of these diets was similar. Pigs given diet C scoured severely and twelve died. 3. Protein digestion was studied in pigs given diets U, B and D, killed at 28 d of age, at the termination of the feeding experiment. The dry matter content and proportion of N in the digesta in the stomach were reduced in pigs given soya-bean protein. Pepsin concentrations in digesta and stomach tissue were unchanged. 4. The concentrations of trypsin and chymotrypsin in the pancreas were greater in pigs given the soya-bean protein concentrate compared with milk protein, but only the increase in trypsin was significant (P less than 0.01). Digesta from the small intestine of pigs given the soya-bean-protein isolate contained less chymotrypsin (P less than 0.05). There were no differences in the proportion of non-protein-N in the total N in the digesta, suggesting that proteolysis of the milk and soya-bean proteins were equally by 28 d of age.

Aging↗

PubMed1994

Protection of pig kidney (PK15) cells from the cytotoxic effect of anti-pig antibodies by alpha-galactosyl oligosaccharides.

Anti-pig antibodies in human and baboon serum are believed to be directed against alpha-galactosyl (alpha Gal) epitopes expressed on various pig cells, including vascular endothelia. We have investigated the effect of human sera on the PK15 pig kidney cell line, which abundantly expresses alpha Gal epitopes. To quantitate cell viability, we have used a staining method that differentiates live cells from dead ones. Various carbohydrates (n = 28) were added individually to serum at concentrations of 0.125-50 mg/ml. Unmodified serum caused approximate 100% PK15 cell death within 60 min. Carbohydrates that were not alpha Gal based did not significantly protect PK15 cells. Of the alpha Gal-based carbohydrates, only B disaccharide protected PK15 cells from both human and baboon serum (76% and 93% protection, respectively, at 1 mg/ml). Three alpha Gal oligosaccharides provided approximately 80-90% protection against both human and baboon sera at a concentration of 10 mg/ml. Three other closely related structures protected only against baboon serum (> 80%) at high concentration (50 mg/ml), suggesting a difference in anti-pig antibody affinity between baboon and man. Specific anti-alpha Gal antibody-depleted serum caused < 10% pig cell death, whereas the antibodies eluted from the alpha Gal columns caused > 70% pig cell death. In conclusion, this study provides further evidence that (1) alpha Gal structures are the targets for human and baboon anti-pig antibodies, and (2) there may be a therapeutic role for the infusion of specific alpha Gal carbohydrates, or for antibody removal using alpha Gal immunoaffinity columns, in order to prevent hyperacute rejection of pig organs in man.

Animals↗

PubMed1997

Hyperacute lung rejection in a pig-to-human transplant model: the role of anti-pig antibody and complement.

BACKGROUND: The physiology of hyperacute rejection of pig lung by human blood and the role of antispecies antibody and complement in this phenomenon have not previously been characterized. METHODS: Human blood was perfused through an ex vivo pig heart-lung preparation. In the treatment groups, blood was either unmodified or modified to deplete alternative pathway complement (heat treatment), anti-pig antibody, or both. Control experiments were performed with unmodified and heat-treated pig blood. Physiologic parameters, organ survival, and immunohistology were the primary outcome measures assessed. RESULTS: Pig lung was consistently damaged by human blood within 45 min (median 20 min), as evidenced by elevated pulmonary vascular resistance and parenchymal injury. Immunohistologic studies of perfused lungs showed prominent deposition of IgM and classical pathway component, C4, and weaker deposition of alternative pathway component, properdin. Heat treatment did not impede the rise in pulmonary vascular resistance or significantly prolong survival. Depletion of anti-pig antibody prolonged survival (median 90 min) and attenuated the rise in pulmonary vascular resistance. Antibody absorption, combined with heat treatment of plasma, prevented the elevation in pulmonary vascular resistance and yielded median graft survival (210 min) similar to pig blood perfusion (approximately 240 min). CONCLUSIONS: These results show that elevated pulmonary vascular resistance and pulmonary parenchymal injury are mediated at least in part by antispecies antibody and heat-sensitive pathways. They are consistent with the hypothesis that complement activation contributes significantly to acute lung damage in the pig-to-human species combination.

Animals↗

PubMed1998

An ELISA technique for quantitation of human xenoantibodies binding to pig cells: application in patients with pig kidneys extracorporeally connected to the circulation.

A quantitative ELISA technique for determination of human anti-pig xenoantibody number in serum samples has been established using pig lymphocytes and pig/rabbit erythrocytes as target cells and a pool of serum from human blood group AB donors. The number of low affinity antibodies binding to the cells was determined by quantitation following the use of aqueous washing of the cells and separation of bound and unbound antibodies with the phthalate oil method. The efficiency of different soluble Gal(alpha)1-3Gal-terminating di- and tri-saccharides to inhibit antibody binding was tested and found to vary between 70-90% at a saccharide concentration of 10 mg/ml. The assay was used to evaluate the antibody changes in two patients who, after plasmapheresis treatments, had pig kidneys extracorporeally connected to their blood circulation. The number of anti-pig IgM/IgG antibodies bound to each pig lymphocyte were reduced from 5,600/13,200 to 1,300/3,100 in patient 1 and from 1,200/6,500 to 500/2,100 in patient 2 by three consecutive daily plasmapheresis treatments. Although the lymphocytotoxic titers were reduced to very low levels, the antibody numbers still present in the blood of patient 1 caused a hyperacute rejection of the pig kidney. However, the antibody levels in patient 2 did not cause rejection of this kidney during 15 min perfusion time. A strong anti-pig antibody response 3 weeks after the perfusion experiment was found in patient 1 as shown by 27,600/245,300 IgM/IgG molecules bound to pig lymphocytes corresponding to an increase of lymphocytotoxic titer from 8 to 512. The second patient showed a much weaker immune response with 1,400/19,800 IgM/IgG antibodies corresponding to a lymphocytotoxic titer increase from 8 to 32. The use of this quantitation technique enables more accurate investigation of antibody binding to xenogenic target cells than conventional titration techniques.

Animals↗

PubMed2006

Parameters favouring successful adult pig islet isolations for xenotransplantation in pig-to-primate models.

BACKGROUND: In the near future, adult porcine islets of Langerhans appear as an unlimited source of insulin-producing cells which could play a major role for treating diabetes mellitus. There is, however, an obvious lack of pre-clinical results and data in the pig-to-primate model. One of the main hurdles of this model is certainly related to the difficulty of reproducing regularly successful porcine islet isolation. This experimental work was designed to provide guidelines applicable in pig pancreas procurement and islet isolation for successful islet xenotransplantation into primates. METHODS: Pancreases were harvested from adult Belgium Landrace pigs (n = 79) in a single centre. The impact on islet yield of (1) pancreas procurement (blood exsanguination and warm ischaemia time (WIT)), (2) cold storage solutions (classic UW and modified UW (without hydroxyethyl starch and inverse K+/Na+ concentration)), (3) a dynamic or static method of pancreas digestion, and (4) the endotoxin content and enzymatic activity from five different batches of Liberase PI was studied. In addition, pancreatic biopsies (n = 18), performed before isolation, were retrospectively analyzed to study the impact of histomorphometry on porcine islet yield. Finally, two diabetic cynomolgus monkeys were transplanted without immunosuppression with 15,000 pig islet equivalents/kg body weight of recipient to assess in vivo the function of freshly isolated islets. Univariate and multivariate analyses were performed. RESULTS: By multiple linear regression, the most significant variables that significantly improved islet yield were, firstly, the presence of <30 EU (endotoxin units) of endotoxin in Liberase batches, followed by a WIT under 10 min and the use of blood exsanguination before pancreas harvesting (P < 0.005). In contrast, isolation method (dynamic vs. static) and the solution used for storage (short-term) (UW vs. modified UW) did not significantly influence islet yield. The correlation of retrospective histomorphometry analysis of native pancreas and extemporaneous biopsy before isolation clearly determined a positive relationship between isolated islet number and the number of islets/cm2 (r = 0.708, P < 0.01) or with the percentage of large islets (r = 0.680, P < 0.01) found in pancreas biopsies. Pig pancreases containing more than 82 islets/cm2 and more than 42% of large islets (>100 microm) thus enabled more than 120,000 islet equivalents to be obtained in 90% of the cases, which is an ideal amount of islets to transplant into a primate of 4 to 5 kg. In vivo, a reduction of blood glucose (<200 mg/dl), associated with porcine C-peptide production, was observed in two primates after transplantation with adult pig islets. At day 7 post-transplantation, however, loss of islet function was associated with graft destruction and immune reaction. CONCLUSIONS: Morphological screening of the pig pancreas before isolation, optimal blood exsanguination, WIT <10 min, and an endotoxin content <30 EU/mg in Liberase PI batches determine successful pig islet isolation for xenotransplantation in primates.

Adenosine↗

PubMed2007

Relation between human decay-accelerating factor (hDAF) expression in pig cells and inhibition of human serum anti-pig cytotoxicity: value of highly expressed hDAF for xenotransplantation.

BACKGROUND: Although the successful production of alpha1,3-galactosyltransferase-knockout (GT-KO) pigs has increased expectations of clinical xenotransplantation, additional modifications of genetically engineered pigs are still being explored, because even GT-KO pigs are incapable of inhibiting the host's immunological response completely. One of the potential candidates is a complement-regulatory protein, such as human decay-accelerating factor (hDAF). However, there are few reports on how high the expression level of hDAF in pig cells would be required for suppression of complement activation. The purpose of this study was to examine the relationship between the level of hDAF expression and its inhibitory effect on human serum cytotoxicity. METHODS: An expression (pCAGGS) vector containing the hDAF gene was transfected into pig fibroblasts using an electroporation system (Gene Pulser II). Forty-eight to fifty-two hours after transfection, the cells were stained with FITC-labeled anti-hDAF antibody and then applied to the cell sorter. hDAF-transfected cells with various expression levels were collected by gating on fluorescence intensity. The level of hDAF expression was determined relative to that in human control endothelial cells. Collected cells expressing x1, x5, x10, x15 and x30 hDAF were incubated into 96-well plates for 16 h, and the cells were subjected to 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: hDAF expression levels in transfected cells at the time of MTT assay (16 h after sorting) were comparable to those immediately after sorting. hDAF expression in pig cells five times higher than in human endothelial cells was effective in inhibiting complement-dependent cytotoxicity of most human sera. However, 15- to 30-fold expression of hDAF was required for effective inhibition of human sera with the highest cytotoxic capacity. CONCLUSIONS: A much higher level of hDAF expression in pig cells than previously considered necessary might be required to provide additional benefit in inhibiting antibody-mediated rejection. Genetically engineered pigs that express very high levels of hDAF would be beneficial for xenotransplantation.

Animals↗

PubMed1981

Drug resistance and R plasmids of Escherichia coli strains isolated from pigs, slaughterers, and breeders of pigs in Japan.

We isolated 1,120 drug-resistant Escherichia coli strains from pigs, slaughterers, breeders of pigs, and urban residents and examined their drug resistance. With reference to resistance to tetracycline (Tc) chloramphenicol (Cm), streptomycin (Sm), and sulfanilamide (Su), Tcr, Smr, and Sur strains were most frequently isolated from pigs (57.9%), followed by slaughterers (50.2%) and breeders (42.4%). By contrast, the isolation frequencies of Tcr, Smr, and Sur strains from urban residents were low (12.0%). The isolation frequencies of R plasmids from resistant strains were more than 50% in the case of pigs, slaughterers, and breeders, whereas they were only 13.8% in urban residents. Kanamycin-resistant strains were frequently isolated from pigs (40.3%), slaughterers (22.6%), and breeders of pigs (25.4%), but seldom (only 3.4%) from urban residents. With ampicillin resistance, the frequencies of strains from pigs, slaughterers, breeders, and urban residents were 30.0, 21.5, 5.6, and 13.8%, respectively. R plasmids specifying these latter resistances were frequently seen from pigs (24.0%), slaughterers (23.6%), and breeders (21.1%), but they were not isolated from urban residents. The results suggest that the porcine gut can function as a reservoir of antibiotic resistance plasmids which can then be directly transferred to humans, with the highest frequency of such plasmids appearing in people in the most immediate contact with these animals.

Abattoirs↗

PubMed1999

Epidemiology of enteric disease in grower-finisher pigs: a postal survey of pig producers in England.

A questionnaire was sent to 238 members of local pig discussion groups in the West Midlands region of England to identify farm level factors associated with the occurrence of diarrhoea in grower-finisher pigs. The questions related to the occurrence, diagnosis and aetiology of scour problems on the farm, the prevalence of common porcine diseases on the farm, the classes of pigs, staff employment, source of replacement stock and biosecurity measures, the husbandry techniques such as piglet management, use of medication, movement and mixing of pigs, dung removal and pen preparation between batches of pigs, and the physical resources such as floor type, pen divisions, watering, feeding and dung disposal systems. Replies from 105 producers keeping grower-finisher pigs were included in the analysis, 50.5 per cent of which had had a scour problem at some time in the previous three years. The causes of scour had been identified as colitis (34.3 per cent), swine dysentery (10.5 per cent) or porcine enteropathy (3.8 per cent). There was a significant association between the following factors and the occurrence of diarrhoea in grower-finisher pigs: the use of water medication for weaners (odds ratio = 11.8; P = 0.002), the tail-docking of piglets (odds ratio = 8.6; P = 0.003), the use of a wet feeding system for finishers (odds ratio = 5.9; P = 0.009), finishers housed on partially slatted floors (odds ratio = 3.6; P = 0.044), and the use of an isolation procedure for incoming breeding stock involving exposure to dung (odds ratio = 3.5; P = 0.046). The use of disinfectant in the preparation of pens between batches of pigs appeared to be protective (odds ratio = 0.3; P = 0.046).

Animal Husbandry↗

PubMed1995

Experimental infection of pigs with a parvovirus isolated from the diarrheic feces of a pig.

A parvovirus (the H-45 strain) isolated from an outbreak of epizootic diarrhea in swine was examined to observe the infectivity and pathogenecity in swine. The virus infection by intranasal route was demonstrated in each group of 2- and 5-day-old colostrum-deprived pigs, 30- and 100-day-old pigs by virus recovery from the nasal and rectal swabs, and detecting seroconversion. The virus was recovered from rectal swabs up to 14 days after inoculation and from nasal swabs up to 9 days. Uninoculated pigs were infected with the virus by contacting with the inoculated pigs. Between 1 and 5 days after inoculation, the inoculated pigs of 2, 5 and 30 days old developed diarrhea and then all the pigs of 2 days old died, resulting from dehydration. In the pigs died after intranasal inoculation, the virus was recovered mainly from the respiratory and gastrointestinal tracts. One hundred-day-old pigs showed no clinical signs. The pathological change was characterised by congestion and edema with hemorrhage in the epithelium of the small intestines exhibiting additional degeneration and desquamation of the epithelial cells.

Aging↗

PubMed2004

[Analysis of presence and difference of sequence of porcine endogenous retrovirus in DNA genomes from peripheral blood white cells of pig and mRNA in tissues from mini-pigs].

The aim is to investigate biological features of porcine endogenous retrovirus (PERV) of pigs in China and to provide basic parameters for evaluation of biological safety of xenotransplantation from pig to human. In this study, basic biologic features of PERV of DNA of peripheral blood white cells of 12 species of domestic pigs in China were examined by polymerase chain reaction; Analysis of difference of PERV gene sequence was investigated by sliver-stained single stranded conformational polymorphism and restriction fragment length polymorphism; Difference of PERV mRNA from a variety of tissue of two species of mini-pig was analysized by reverse transcriptase-PCR and semi-quantitative analysis. These results showed that Sequences of PERV-A, -B genes are ubiquitous in DNA genome of peripheral blood white cells in the examined pigs; There was no single stranded conformational polymorphism in PERV-A, -B gene sequences. There is the phenomenon of restriction fragment length polymorphism of sequence of PERV env gene in DNA genome of peripheral blood white cells in some pigs of the examined pigs. The PERV-A, -B and -C are expressive in a variety of tissues from two species of mini-pig, higher in kidneys, lymph nodes and livers, lower in pancreas and brains. It is deserved that the phenomenon of restriction fragment length polymorphism of PERV and the absence and mismatch of base of sequence of PERV-A may induce potential hazard of infection of PERV during xenotransplantation.

Animals↗

PubMed1987

Intranasal vaccination of pigs against Aujeszky's disease: comparison with one or two doses of attenuated vaccines in pigs with high maternal antibody titres.

Ten-week-old pigs with high levels of maternally derived antibody (MDA) against Aujeszky's disease virus (ADV) were given either a single intranasal vaccination or one or two doses (with an interval of three weeks) of commercially available attenuated ADV vaccines intramuscularly. The pigs did not produce a clear neutralising antibody response to ADV. However, pigs vaccinated intranasally and pigs given two doses of attenuated ADV vaccines were protected against intranasal challenge with virulent ADV two months after the first vaccination. Pigs given one parenteral dose of attenuated ADV vaccine were insufficiently protected. Protection was shown by shorter periods of growth arrest and fever and a greater reduction of virulent virus shedding after challenge in vaccinated pigs than in unvaccinated control pigs. Although intranasal vaccination conferred protection comparable to two parenteral doses of attenuated vaccines, it reduced shedding of virulent virus much more effectively. These results, together with those of other studies, show that intranasal vaccination confers better protection against Aujeszky's disease in pigs with MDA than parenteral vaccination. However, the efficacy of intranasal vaccination also decreases with increasing levels of MDA at the time of vaccination.

Administration, Intranasal↗

PubMed1981

Route of lymphocyte migration in pigs. II. Migration to the intestinal lamina propria of antigen-specific cells generated in response to intestinal immunization in the pig.

Intestinal lymph-duct cannulae were established in normal and mesenteric lymphadenectomized (MLNx) pigs for the 6-day duration of a local intestinal immune response to a protein antigen (ovalbumin). The daily output of anti-ovalbumin-containing cells (AOCC) in intestinal lymph and the numbers of AOCC in the intestinal lamina propria at the end of the experiment were recorded. Very few AOCC were recovered in the intestinal lymph of normal pigs whereas in MLNx pigs large numbers were recovered reaching a peak output on day 4. However, there were significantly more AOCC detected in the jejunal lamina propria of normal pigs than MLNx pigs despite continuous drainage of intestinal lymph throughout the response. The absence of AOCC from efferent intestinal lymph of normal pigs, the failure of chronic intestinal-lymph drainage to abrogate the AOCC response in the intestine of these pigs and the reversal of these findings in MLNx pigs indicate that, in contrast to other species, lymphoblasts are diverted from porcine intestinal lymph, and probably enter the blood circulation at the level of the mesenteric lymph node (MLN).

Animals↗

PubMed1995

A comparison of membrane enzymes of human and pig oesophagus; the pig oesophagus is a good model for studies of the gullet in man.

The distribution and relative catalytic activities of five plasma membrane enzymes (alkaline phosphatase, dipeptidyl peptidase IV, gamma-glutamyl transpeptidase, microsomal alanyl aminopeptidase and glutamyl aminopeptidase) were examined in human and pig oesophagus. In both species, alkaline phosphatase activity occurred in basal and suprabasal cells of the epithelium and in capillaries. Stromal cells in the human submucosa were particularly reactive. Dipeptidyl peptidase IV was present in blood vessels and capillaries in man and pig and in submucous glands in the pig. The enzyme was also present in both species in the lamina propria cells immediately adjacent to the epithelial basal lamina. In the human, gamma-glutamyl transpeptidase occurred in the epithelial basal cells and in isolated basal and lower prickle cells in the pig. Stromal cells in the human submucosa were strongly reactive and capillaries in the muscularis propria in both species moderately active. Microsomal alanyl aminopeptidase was detected in lamina propria cells adjacent to the epithelial basal cell layer in man and pig and at the apices of mucous cells in pig submucous glands. Weak glutamyl aminopeptidase activity was confined to capillaries in both species. The findings of this study, along with the ready availability of pig oesophagus, suggest that the pig may be a suitable model for studies of the gullet in man.

Animals↗

PubMed1983

Malignant transformation of guinea pig cells after exposure to ultraviolet-irradiated guinea pig cytomegalovirus.

Guinea pig cells were malignantly transformed in vitro by ultraviolet (uv)-irradiated guinea pig cytomegalovirus (GPCMV). When guinea pig hepatocyte monolayers were infected with uv-irradiated GPCMV, three continuous epithelioid cell lines which grew in soft agarose were established. Two independently derived GPCMV-transformed liver cells and a cell line derived from a soft agarose clone of one of these lines induced invasive tumors when inoculated subcutaneously or intraperitoneally into nude mice. The tumors were sarcomas possibly derived from hepatic stroma or sinusoid. Transformed cell lines were also established after infection of guinea pig hepatocyte monolayers with human cytomegalovirus (HCMV) or simian virus 40 (SV40). These cell lines also formed colonies in soft agarose and induced sarcomas in nude mice. It is concluded that (i) GPCMV can malignantly transform guinea pig cells; (ii) cloning of GPCMV-transformed cells in soft agarose produced cells that induced tumors with a shorter latency period but with no alteration in growth rate or final tumor size; and (iii) the tumors produced by GPCMV-and HCMV-transformed guinea pig cells were more similar to each other in growth rate than to those induced by SV40-transformed guinea pig cells.

Animals↗