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PubMedDate not supplied

Hepatic lipid profiles in miniature pigs after alcohol feeding.

Changes in lipid profiles have not been reported for the known increases in total lipid content in livers of alcoholics. We have reported a lowering of the beta-oxidative capacity of alcoholic livers, and therefore would expect a lower turnover of fatty acids in these livers, and thus a change in lipid profile. The percentage composition of saturated and unsaturated fatty acids in the liver of alcohol-fed miniature pigs versus the controls, as well as the function of distance from the main hepatic vein, have both been determined in this study involving the feeding of ethanol for one year. Livers of alcohol-fed miniature pigs contained more total lipids than those of controls. Results also indicated significantly higher percentages of free fatty acids and triglycerides in the alcohol-fed miniature pigs, and also an increase in percentage total neutral lipids. The effect of distance from the main blood source (and therefore oxygenation) gave a fatty acid profile that showed an increase in the ratio of saturated to unsaturated fatty acids with increasing distance from the right hepatic vein. This change in ratio was independent of alcohol feeding.

Animals↗
PubMed2006

Miniaturization of asymmetrical flow field-flow fractionation and application to studies on lipoprotein aggregation and fusion.

Asymmetrical flow field-flow fractionation (AsFlFFF), a technique that provides direct measurement of particle size and diffusion coefficient, is converted into miniaturized scale. In comparison with conventional AsFlFFF, the separation of proteins in miniaturized AsFlFFF is achieved within shorter time periods, with smaller sample amounts, and with lower mobile phase consumption. Minimization of the overloading and optimization of the separation efficiency are prerequisites to good results. Miniaturized AsFlFFF is applied to the measurement of particle sizes of high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL). The average hydrodynamic diameters at pH 7.4 in 8.5mM phosphate buffer containing 1mM EDTA and 150 mM NaCl are 8.6+/-0.5, 11.2+/-0.2, 22.1+/-0.7, and 48.9+/-7.5 nm for subgroups HDL3, HDL2, LDL, and VLDL, respectively. In addition, the effect of different factors on the aggregation and fusion of LDL particles is studied. LDL particle sizes are unaffected by the addition of up to 300 mM NaCl and by an increase of the carrier solution pH from 3.2 to 7.4, but treatment of LDL with alpha-chymotrypsin, sphingomyelinase, or copper sulfate leads to the formation of aggregated and fused LDL particles.

Chymotrypsin↗
PubMed2005

Miniaturized cardiopulmonary bypass in coronary artery bypass surgery: marginal impact on inflammation and coagulation but loss of safety margins.

PURPOSE: Inflammation and coagulation disturbances are common consequences of cardiopulmonary bypass (CPB). Recently, miniaturized closed CPB circuits without cardiotomy suction and venous reservoir have been proposed to reduce complication rates. We compared outcomes with conventional (CCPB) and miniaturized cardiopulmonary bypass (MCPB) after coronary artery bypass operations (CABG) with respect to inflammation and coagulation. DESCRIPTION: Thirty patients (23% female; aged 67.9 +/- 9.0 years) were prospectively randomly assigned to undergo isolated CABG with CCPB or MCPB. Conventional CPB had a pump prime of 1, 600 mL. Miniaturized CPB consisted of a centrifugal pump, arterial filter, heparinized tubing, and oxygenator with a priming volume of 800 mL. Shed blood was removed by a cell-saving device and reinfused. Measurements included interleukin (IL)-2 receptor, IL-6, IL-10, tumor necrosis factor receptor 55 and 75, C reactive protein, leukocyte differentiation, d-dimers, fibrinogen, and thrombocytes at six time points. EVALUATION: In both groups no major complication occurred. However, two dangerous air leaks occurred in the closed MCPB circuit, demonstrating the narrow safety margins. Operative handling was also more difficult owing to limitations in venting and fluid management. International normalized ratio (p = 0.03) and antithrombin III (p = 0.04) levels were elevated during CPB in the CCPB group, most likely owing to differences of the intraoperative anticoagulation management. Repeated measures analysis revealed that not a single parameter of inflammation or clinical outcome showed significant differences among groups. CONCLUSIONS: Use of a MCPB affected inflammation and coagulation variables only marginally and did not lead to clinical relevant changes as assessed by blood loss, need for blood products, and intensive care unit and clinical stays. However, safety margins for volume loss, air emboli, and weaning from CPB decrease, because of the closed MCPB circuit.

Adult↗
PubMed2006

Effects of NO-1886 on inflammation-associated cytokines in high-fat/high-sucrose/high-cholesterol diet-fed miniature pigs.

Inflammation, closely associated with obesity, is emerging as an important risk factor for the pathophysiological development of atherosclerosis and diabetes mellitus. Fat balance is critical in the aetiology of obesity. Lipoprotein lipase is an important enzyme in lipid metabolism. The aim of this study was to investigate the long-term effect of the lipoprotein lipase activator, NO-1886, on inflammation cytokines, adiposity and related diseases in miniature pigs fed a high-fat/high-sucrose/high-cholesterol diet (HFSC diet). Chinese Bama-miniature pigs were fed a control diet or HFSC diet with or without NO-1886 for 5 months. The levels of inflammation-associated cytokines were determined using the antibody arrays. Feeding of the HFSC diet to miniature pigs markedly increased the expression of inflammatory cytokines. On the other hand, supplementation of NO-1886 to HFSC diet decreased the expression of inflammatory cytokines significantly, protecting against the development of atherosclerosis and diabetes mellitus. NO-1886 may have a beneficial effect on the most inflammation-associated cytokines, and this effect may contribute to improving atherosclerosis and diabetes mellitus.

Animals↗
PubMed2001

Miniaturized solid-phase extraction with resin disks.

The properties and advantages of membrane disks for solid-phase extraction (SPE) are described. Miniaturization is a trend in SPE, as well as chemical analysis in general. A semimicro method is reviewed in which an extraction disk 4 mm in diameter is used for SPE. Even smaller scale separations are possible with a device in which a membrane 0.7 mm in diameter was incorporated into the needle of a 50-micro syringe. Aqueous samples containing 10 ppb of eight substituted benzenes were passed through the miniaturized-SPE syringe automatically using a single-syringe infusion pump. Elution volumes of 5 microl provided 500-fold concentrations and delivered average recoveries greater than 90% and an average relative standard deviation (RSD) of 4.6% for the analytes. Direct injection of the 5 microl eluate from the miniaturized-SPE syringe into a gas chromatograph also produced average recoveries greater than 90% and an average RSD of 6.2%.

Benzene Derivatives↗
PubMedDate not supplied

New miniaturized versus conventional biplane transesophageal transducers: recent clinical experience in adults.

A subset of patients have substantial discomfort on examination with transesophageal echocardiography with the conventional probe, whereby the dimensions of the probe play a decisive role. Miniaturized biplane transducers have recently become available (2 x 32 channels, dimensions 9.5 x 8.7 mm, and circumference approximately 30% less than the conventional echoscope) and allow ultrasound examination at 3.5, 5.0 and 7.0 MHz. A prospective study was carried out in 90 patients to compare difficulties on insertion of the probe, subjective evaluation by the patient during examination, and the two-dimensional image, as well as Doppler and color-coded Doppler quality of the miniaturized biplane versus the conventional probe. In 62 patients, intubation of the esophagus proved less difficult with the smaller instrument and more difficult in nine cases. Seventy-six patients reported that they suffered less discomfort on use of the narrow instrument. Concomitant parasympatholytic medication was needed with the smaller probe in seven cases and 17 times with the conventional probe. As anticipated, quality of the two-dimensional image attained by the miniaturized probe was lower. With transmit/receive frequency of 7.0 MHz, however, image resolution was excellent in the near field of 5 cm and nearly equivalent to that of the conventional probe (5.0 MHz). Pulsed-wave and continuous wave Doppler and color-coded Doppler information from both probes was similar in quality. Whenever examination with a conventional transesophageal transducer promises to be difficult, or when sedation is contraindicated because of a severe illness or respiratory insufficiency, transesophageal echocardiography should be considered with a smaller biplane probe at higher transmit-receive frequencies.

Adolescent↗
PubMed2001

Morphometric analysis of miniature swine hearts as potential human xenografts.

Miniature swine are considered to be potential donors for clinical cardiac transplantation. However, it is unclear how an appropriately sized porcine donor will be selected for a particular human recipient. To address this issue, we performed a morphometric study of the swine heart using transthoracic echocardiography (n = 26) to determine the diameters of the aortic annulus and root, pulmonary artery annulus, and mitral valve annulus. We also obtained direct ex vivo measurements of swine heart weight and linear dimensions (n = 71). Relationships between a swine's height, weight, length, chest circumference and these internal and external cardiac dimensions are described. The strongest correlations were found between a pig's body length and its aortic annulus and root diameters (r-values = 0.97). These relationships are accurately described by univariate linear regression models. By cross-relating our morphometric measurements of aortic annulus diameter in the miniature swine with normative human data, we were able to develop a nomogram, relating swine length and human height, which predicts which miniature swine would donate the best size-matched heart for a particular human recipient.

Animals↗
PubMed1998

In vivo evaluation of the miniaturized Gyro centrifugal pump as an implantable ventricular assist device.

A miniaturized Gyro centrifugal pump has been developed to be incorporated into a totally implantable artificial heart. The Gyro PI (permanently implantable) model is a pivot bearing supported centrifugal pump with a priming volume of 20 ml. With the miniaturized actuator, the pump-actuator package has a height of 53 mm, a diameter of 65 mm, and a displacement volume of 145 ml. To evaluate the hemocompatibility and efficiency of the Gyro PI pump system, a plastic prototype (Gyro PI-601) was implanted into a bovine model as a left or right ventricular assist device (LVAD or RVAD), bypassing from the left ventricular apex to the descending aorta or from the right ventricular infundibulum to the main pulmonary artery. The calves were anticoagulated with heparin to maintain activated clotting times from 150 to 200 s. Four calves were supported for 23, 24, and 50 days in the LVAD studies, and 40 days in the RVAD study. The first calf died due to intrathoracic bleeding associated with sepsis. The second calf was euthanized for a low flow rate less than 2 L/min due to an obstructed inflow with growing pannus. The third and fourth calves were euthanized as scheduled. Renal and hepatic functions remained normal, and plasma free hemoglobin values were less than 8 mg/dL throughout the experiments. The fourth case showed flow rates of 4.83 +/- 0.57 L/min, input power of 6.16 +/- 0.49 W, and the inside temperature of the actuator of 43.5 +/- 0.52 degrees C. The pumps implanted in the fourth calf demonstrated no thrombus formation at the autopsy. These in vivo experiments revealed that the Gyro PI pump can provide adequate flow as an easily implantable, efficient, antithrombogenic, and nonhemolytic centrifugal LVAD or RVAD with miniaturized actuators.

Animals↗
PubMed2005

Developmental competence of somatic cell nuclear transfer embryos reconstructed from oocytes matured in vitro with follicle shells in miniature pig.

The developmental competence of domestic pig oocytes that were transferred to somatic cell nuclei of miniature pig was examined. A co-culture system of oocytes with follicle shells was used for the maturation of domestic pig oocytes in vitro. Co-cultured oocytes progressed to the metaphase II stage of meiosis more quickly and more synchronously than non co-cultured oocytes. Oocytes were enucleated and fused with fibroblast cells of Potbelly miniature pig at 48 h of maturation. The blastocyst formation rate of nuclear transfer (NT) embryos using cocultured oocytes (24%) was significantly higher (p < 0.05) than that of non-co-cultured oocytes (13%). Cleaved embryos at 48 h after nuclear transfer using co-cultured oocytes were transferred to the oviducts of 14 Göttingen miniature pigs and four Meishan pigs. Estrus of all Göttingens returned at around 20-31 days of pregnancy. Two of the four Meishans became pregnant. Three and two cloned piglets were born after modest number of embryo transfer (15 and 29 embryos transferred), respectively. These results indicated that oocytes co-cultured with follicle shells have a high developmental competence after nuclear transfer and result in full-term development after embryo transfer.

Animals↗
PubMed2005

A novel miniaturized flame ionization detector for portable gas chromatography.

A novel miniaturized flame ionization detector (FID) operated by battery, which can be used as a detector in portable gas chromatography (GC) is devised and manufactured. It is characterized by the structure of building blocks, small volume, low energy consumption, and needing only two gases, which can be used for detection of hydrocarbons in portable GC. The miniaturized detector mainly includes a porous metallic diffuser plate, bugle-figuration collector, quartz capillary flame tip, and self-heated system. The miniaturized FID is easy to fabricate and assemble because of its structure of building blocks. The FID response is linear over six orders of magnitude and the detection limit of 0.518 ng for benzene, 0.430 ng for n-dodecane, 0.473 ng for naphthalene, and 0.509 ng for n-tetradecane.

Alkanes↗
PubMed1999

Recovery of 15N-lactoferrin is higher than that of 15N-casein in the small intestine of suckling, but not adult miniature pigs.

Performance of biological functions of lactoferrin in the small intestine requires at least some resistance to degradation. Therefore, we studied prececal digestibility of lactoferrin in comparison to casein both in suckling and adult miniature pigs, applying 15N-labeled proteins. In study 1, 43 piglets (10-d-old), deprived of food for 12 h received 10 mL of sow's milk supplemented with 120 mg of 15N-labeled protein (porcine or bovine lactoferrin or bovine casein). Piglets were anesthetized 150 min later, after which the small intestine was excised, cut into three sections, and chyme was collected. In study 2, nine food-deprived boars fitted with T-canulae at the terminal ileum were given two semisynthetic experimental meals (204 g) in a cross-over design, 2 wk apart. One contained 7.5% (g/100 g) 15N-labeled bovine casein, the other 1.25% 15N-labeled bovine lactoferrin. Both were adjusted to 15% total protein with nonlabeled casein. Ileal chyme was collected from the canula over 33 h postprandially. All diets contained the indigestible marker chromic oxide. 15N-digestibility of lactoferrin, both porcine (84.4 +/- 3.2%) and bovine (82.3 +/- 4.8%), was significantly lower than casein digestibility (97.6 +/- 0.5%) in the distal small intestine of suckling piglets (P < 0.05). Based on immunoblotting after acrylamide electrophoresis, 4.5% of non- and partially digested lactoferrin was found in the last third of the small intestine of piglets. In adult miniature pigs there was no difference in 15N-digestibility of bovine lactoferrin compared to bovine casein (90.7 +/- 1.9% vs. 93.9 +/- 1.0%, P > 0.05). In suckling miniature pigs, the reduced digestibility of lactoferrin may provide the prerequisite for biological actions along the whole intestinal tract. The source of lactoferrin, porcine or bovine, made no difference in this respect.

Aging↗
PubMed2000

Cytokine-mobilized peripheral blood progenitor cells for allogeneic reconstitution of miniature swine.

BACKGROUND: Because of the relative ease of acquisition, increased yield, and improved engraftment characteristics, mobilized peripheral blood progenitor (stem) cells (PBSCs) have recently become the preferred source for hematopoietic stem cell transplantation. In our laboratory, procurement of a megadose of PBSCs is necessary for on-going studies evaluating non-myelosuppressive transplant regimens for the induction of mixed chimerism and allograft tolerance. To exploit hematopoietic growth factor synergy, we have sought to combine growth factors with proven utility to improve PBSC mobilization and maximize our PBSC procurement through an automated collection procedure. METHODS: Mobilization characteristics of PBSCs were determined in 2-5-month-old miniature swine. Animals received either swine recombinant stem cell factor (pSCF, 100 microg/kg) and swine recombinant interleukin 3 (pIL-3, 100 microg/kg), administered intramuscularly for 8 days, or pSCF, pIL-3, and human recombinant granulocyte-colony stimulating factor (hG-CSF), at 10 microg/kg. Leukapheresis was performed beginning on day 5 of cytokine treatment and continued daily for 3 days. RESULTS: Collection of PBSCs from cytokine-mobilized animals via an automated leukapheresis procedure demonstrated a 10-fold increase in the number of total nucleated cells (TNC) (20-30 x 10(10) TNC) compared to bone marrow harvesting (2-3 x 10(10) total TNC). A more rapid rise in white blood cells (WBCs) was seen after administration of all three cytokines compared to pSCF and pIL-3 alone. An increase in colony-forming unit granulocyte-macrophage frequency measured daily from peripheral blood during cytokine treatment, was seen with the addition of hG-CSF to pSCF/pIL-3 correlating well with the rise in WBCs. Similarly, the addition of hG-CSF demonstrated a notable increase in the median progenitor cell yield from the 3-day leukapheresis procedure. Cytokine-mobilized PBSCs were capable of hematopoietic reconstitution. PBSCs mobilized with pSCF/pIL-3 were infused into an SLA-matched recipient conditioned with cyclophosphamide (50 mg/kg) and total body irradiation 1150 cGy. Neutrophil and platelet engraftment occurred on days 5 and 7, respectively, with minimal evidence of graft-versus-host disease. Complete donor chimerism has been demonstrated 331 days after transplant. CONCLUSIONS: Our preliminary results show that in this well-defined miniature swine model, recombinant swine cytokine combinations (pSCF, pIL-3 with or without hG-CSF) successfully mobilize a high yield of progenitor cells for allogeneic transplantation. Furthermore, these cytokine-mobilized PBSCs demonstrate the potential to reconstitute hematopoiesis and provide long-term engraftment in miniature swine.

Animals↗
PubMed2001

Peripheral regulation of graft-versus-host alloreactivity in mixed chimeric miniature swine.

BACKGROUND: Despite the presence of circulating donor-derived T cells during the induction of mixed chimerism across MHC barriers in miniature swine, severe graft-versus-host disease was avoided in the majority of animals. In this study, we investigated the possible roles of recipient and donor lymphoid populations in the regulation of donor-anti-recipient alloreactivity. METHODS: Mixed chimerism across a full MHC-mismatch barrier was established in miniature swine using a high-dose allogeneic peripheral blood stem cell protocol. Peripheral blood mononuclear cells from mixed chimeric swine were co-cultured with naïve donor-matched responders and naïve recipient-matched stimulators in mixed lymphocyte reactions. RESULTS: Peripheral blood mononuclear cells from mixed chimeras inhibited donor-anti-recipient proliferation. This suppression was radioresistant to 25 Gy. Suppression of donor-anti-recipient alloreactivity was not observed in mixed lymphocyte co-cultures when donor-derived cells were added in the absence of recipient-derived cells. CONCLUSIONS: These results suggest an association between the presence of an active and relatively radioresistant cell population, demonstrable in vitro, and the regulation of graft-versus-host disease across MHC barriers in mixed chimeric miniature swine.

Animals↗
PubMed2001

Neuropathy in miniature swine after administration of the mutant diphtheria toxin-based immunotoxin, pCD3-CRM9.

BACKGROUND: Effective in vivo T-cell depletion is a critical component of many transplantation tolerance protocols. We have previously demonstrated T-cell depletion in miniature swine using a CRM9-based CD3-immunotoxin, pCD3-CRM9. CRM9 is a mutant form of diphtheria toxin (DT) that binds less efficiently than wild-type DT to the DT receptor (proHB-EGF) of primates. In this report, we describe and characterize the dose-dependent neurotoxicity associated with CRM9-based immunotoxin administration in swine. METHODS: Miniature swine were treated with varying doses of pCD3-CRM9 followed by daily monitoring for symptoms of neuropathy, including limb weakness, paresis, sluggishness, and/or respiratory distress. Animals demonstrating severe respiratory distress were euthanized and peripheral nerve, spinal cord, and skeletal muscle tissue samples were obtained at autopsy for microscopic examination. Unconjugated CRM9 was administered to one animal to define its toxicity independent of the effects of T-cell depletion. RESULTS: Excellent T-cell depletion was obtained using doses of pCD3-CRM9 greater than 0.1 mg/kg. However, neurotoxicity was observed at these doses, as manifested by transient muscle weakness or paresis, which in some cases progressed to respiratory failure and death. Dorsal root ganglia samples revealed pathological changes typical of diphtheritic polyneuropathy. The animal receiving unconjugated CRM9 exhibited the same neurotoxic side effects as those receiving the pCD3-CRM9 conjugate. CONCLUSIONS: Administration of pCD3-CRM9 immunotoxin provides excellent T-cell depletion in miniature swine but is associated with significant dose-dependent neurotoxicity. A possible reason for CRM9-associated neurotoxicity in swine, but not primates, is suggested on the basis of a known amino acid difference in the exodomain of the DT receptor (proHB-EGF) of swine compared with that of primates.

Amino Acid Sequence↗
PubMed2006

Allosensitization does not increase the risk of xenoreactivity to alpha1,3-galactosyltransferase gene-knockout miniature swine in patients on transplantation waiting lists.

BACKGROUND: The recent availability of alpha1,3-galactosyltransferase knockout (GalT-KO) miniature swine has eliminated anti-Gal antibodies as the major barrier to xenotransplantation, potentially bringing this modality closer to clinical application. Highly-allosensitized patients, who have poor prospects of receiving a suitable cross-match negative human organ, might be the first patients to benefit from xenotransplantation of porcine organs. However, concerns exist regarding cross-reactivity of alloreactive anti-human leukocyte antigen (HLA) antibodies against xenogeneic swine leukocyte antigen (SLA) antigens. We have investigated this question using sera from such patients on GalT-KO target cells. METHODS: Using flow cytometry and complement-dependent cytotoxicity (CDC) assays, we have tested a panel of 88 human serum samples from patients awaiting cadaveric renal allotransplantation for reactivity against: 1) human; 2) standard miniature swine; and 3) GalT-KO peripheral blood lymphocytes (PBL) and cultured endothelial cells. RESULTS: Anti-swine IgM and IgG antibody binding, as well as CDC, were significantly attenuated on GalT-KO versus standard swine. No correlation was found between the degree of anti-human panel reactive antibodies (PRA) and xenoreactivity against either standard or GalT-KO miniature swine. Treatment of sera with dithiothreitol (DTT) showed that the majority of remaining lymphocytotoxicity against GalT-KO swine was mediated by preformed IgM antibodies. Patients with high alloreactivity but low anti-GalT-KO xenoreactivity were readily identified. CONCLUSIONS: Highly allosensitized patients awaiting renal transplants appear to be at no increased risk of xenosensitization over their non-sensitized cohorts, and could therefore be candidates for xenotransplantation using GalT-KO swine donors.

Animals↗
PubMed2005

Autonomous stair-climbing with miniature jumping robots.

The problem of vision-guided control of miniature mobile robots is investigated. Untethered mobile robots with small physical dimensions of around 10 cm or less do not permit powerful onboard computers because of size and power constraints. These challenges have, in the past, reduced the functionality of such devices to that of a complex remote control vehicle with fancy sensors. With the help of a computationally more powerful entity such as a larger companion robot, the control loop can be closed. Using the miniature robot's video transmission or that of an observer to localize it in the world, control commands can be computed and relayed to the inept robot. The result is a system that exhibits autonomous capabilities. The framework presented here solves the problem of climbing stairs with the miniature Scout robot. The robot's unique locomotion mode, the jump, is employed to hop one step at a time. Methods for externally tracking the Scout are developed. A large number of real-world experiments are conducted and the results discussed.

Algorithms↗
PubMed2003

Toward virtual biopsy through an all fiber optic ultrasonic miniaturized transducer: a proposal.

The present generation of devices based on opto-acoustic and acousto-optic conversion lets us foresee the possibility of realizing complete miniaturized transmitting-receiving transducers, able to generate and detect wideband ultrasounds by laser light. In the present paper, a miniaturized ultrasonic transducer entirely based on fiber optic technology is proposed. Such a device springs from the conjunction between our research, which has produced a highly efficient fiber optic opto-acoustic source, with the results obtained by other researchers concerning the realization of an ultrasonic receiver based on optical interferometry. Making use of the thermo-elastic effect for ultrasound generation, a source of ultrasound can be obtained by coupling a fiber optic to pulsed laser, if a film capable of absorbing laser light is placed onto fiber end. Starting from these remarks, we propose an efficient opto-acoustic source, able to generate pressure pulses with amplitude of the order of 10(4) Pa and bandwidth extending up to 40 MHz and beyond by using graphite materials as absorbing film. This solution makes use of a low-power pulsed laser as optical source possible. An ultrasonic receiving element was realized placing a Fabry-Perot cavity over the tip of a fiber optic. The cavity thickness modulation induced by ultrasonic beam is detected by an interferometer optical technique. We have realized a prototype of a receiving device that exhibits a sensitivity comparable with that of piezoelectric devices (10-100 nV/Pa) and an almost flat bandwidth extending up to 20 MHz or more. The extreme miniaturization of the resulting ultrasonic transducer, together with its wide ultrasonic frequency bandwidth, is the first step toward ultrasonic tissue biopsy. In this paper, before discussing the problem of constructing a complete ultrasonic transducer composed by a transmitter and receiver, the results carried out in these fields during the last decade are reviewed.

Biopsy↗
PubMed2004

Molecular investigation of hepatitis E virus infection in domestic and miniature pigs used for medical experiments.

BACKGROUND: Hepatitis E virus (HEV) infection is highly prevalent among domestic pigs in Japan. It has been reported that pig handlers such as farmers and veterinarians are at increased risk of contracting HEV infection. Pigs are regarded as the most acceptable candidate animals for xenotransplantation and, recently, they are being used as experimental animals. METHODS: We investigated the prevalence of IgG class antibodies to swine HEV (anti-HEV) and HEV RNA among 152 2-month-old domestic pigs and 38 miniature pigs of 4 to 10 months of age that had been brought to our center for medical experiments from five swine farms (A-E) in Japan. Serum samples were tested for anti-HEV by in-house enzyme immunoassay, and for HEV RNA by reverse transcription-polymerase chain reaction using primers targeting the open reading frame 2 (ORF2) region. RESULTS: One percent (one of 84), 6% (one of 16), and 38% (20 of 52) of the domestic pigs from farms A, B and C, respectively, had detectable HEV RNA, and the 22 HEV isolates recovered from the viremic pigs were 89.8 to 100% identical to each other in the 412-nucleotide sequence of ORF2 and segregated into three clusters within genotype 3. Although one pig from farm A had detectable HEV RNA reproducibly, the HEV isolate recovered from this pig was up to 100% similar to those recovered from pigs from farm C, and the sera from all 84 pigs from farm A were negative for anti-HEV. These results suggested that farm A is free from HEV infection. As the viremic pig from farm A had been raised for 1 month in a barn at our center before serum sampling, it is most likely that the pig acquired HEV infection in the barn at our center where HEV-viremic pigs from farm C had been reared for several days approximately 3 months earlier. The 38 miniature pigs from farms D and E were negative for both anti-HEV and HEV RNA. In an attempt to further investigate the prevalence of HEV infection, pigs that were being raised in four swine farms (farms A, C, D, and E) were tested for anti-HEV. Although 96 (86%) of the 112 pigs from farm C were positive for anti-HEV, none of the 48 pigs in farm A and 138 miniature pigs in farms D and E was positive for anti-HEV. CONCLUSIONS: These results suggest that three of the five swine farms tested were free from HEV, and that periodic testing for anti-HEV and HEV RNA of pigs used as experimental animals and pigs raised in swine farms from which pigs are purchased, is useful for providing HEV-free pigs to researchers who are engaged in studies using pigs.

Animals↗