Porcine heterotopic composite tissue allograft transplantation using a large animal model for preclinical studies

BACKGROUND

Composite tissue allograft (CTA) transplantation is currently limited by the risks of side effects resulting from long-term high-dose immunosuppression. Therefore, preclinical animal models are essential to help CTA transplantation advance into clinical reality. Evidence has shown that small-animal model (rodents) immunotherapy protocols cannot be directly applied to humans. This study investigated whether a miniature porcine model is reproducible for preclinical studies.

METHODS

Based on the concept of vascularized skeletal tissue allograft transplantation, limb heterotopic allograft tissue from a mismatched donor miniature pig consisting of the distal femur, knee joint, tibia, fibula, and surrounding muscle with a vascularized skin paddle model supplied by the superficial femoral vessels was transplanted into recipient pigs. Swine viability and rejection signs of the allograft were monitored postoperatively. Histopathological changes in the allograft tissues were examined using hematoxylin and eosin staining if the allo-skin flap was rejected.

RESULTS

The recipient pigs were ambulatory immediately following surgery. The flaps showed no visible signs of rejection over the first 4 days of observation. The skin flaps appeared bluish-purple and edematous on postoperative days 5 approximately 7, and progressed to tissue necrosis and rejection on postoperative days 8 approximately 13. Histological examination revealed marked mononuclear cell infiltration and necrotic changes in the all rejected tissues, especial in the allograft skin tissues (skin > muscle > bone > cartilage).

CONCLUSIONS

The results showed this the porcine CTA model is reproducible and suitable for preclinical training for human CTA transplantation. Monitoring of the allo-skin flap is a useful strategy to evaluate composite tissue allograft rejection.

Hyperfibrinogenemia Alone Does Not Affect the Patency of Microvascular Anastomosis

Preventing vascular thrombosis in microsurgery is a prerequisite for a successful outcome. High plasma fibrinogen levels have been associated with thromboembolic risk in patients with cancer or cardiovascular disease. Patients with these comorbidities and associated hyperfibrinogenemia oftentimes require microsurgical reconstruction. This situation causes us to hesitate. Previously in our experience, 8 of 10 patients with hyperfibrinogenemia (> 500 mg/dL) underwent successful free-tissue transfer after oral cancer ablation. Based on this clinical observation, we investigated whether hyperfibrinogenemia contributes to the patency of a microvascular anastomosis. Optimal dosage of fibrinogen (300 mg/kg, intravenously) significantly increased the fibrinogen level in the plasma of the rodent hyperfibrinogenemia model. Forty male Lewis rats (weight = 300-350 g) were injected intravenously by normal saline and fibrinogen (300 mg/kg), respectively (n = 20 in each subgroup). Femoral artery and femoral vein division and reanastomosis were performed after 2 hours in rats with or without fibrinogen injection. The platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and the platelet aggregation test induced with adenosine diphosphate (ADP) were also measured preoperatively. The ratios of circulating activated platelets as demonstrated by p-selectin (CD62P) was analyzed by flow cytometry preoperatively and 2 hours postoperatively. Laser Doppler flowmetry was used to assess the patency of the anastomosis preoperatively and 2 hours postoperatively. Vascular patency was assessed 7 days postoperatively. The results showed that the platelet count, PT and APTT levels had no significant difference among the control and the experimental group. There were no significant differences found in the ratios of CD62P expression (P = 0.65) and ADP aggregation test (P = 0.17) in comparing both groups. There were no statistical differences in the patency rates (P > 0.05) or perfusion units of femoral arteries (P = 0.84) and femoral veins (P = 0.51) after vessels division and reanastomosis, respectively. In summary, there was no correlation between experimentally induced hyperfibrinogenemia and the enhancement of thrombosis risk after microvascular surgery. This experimental data can lend support to the idea that microvascular anastomosis could be safely performed in patients with hyperfibrinogenemia alone without untoward thrombotic complications.

Activation of ERK and p38 kinase mediated keloid fibroblast apoptosis after flashlamp pulsed-dye laser treatment

BACKGROUND AND OBJECTIVES

Flashlamp pulsed-dye lasers (PDLs) revealed effective regression or arrest in patients with keloids in our clinical studies [Kuo YR et al., Laser Surg Med 2004;34:104-108]. In this study, we further investigated whether the induction of keloid regression seen with PDL treatment through activation in mitogen-activated protein (MAP) kinase and caspase promotes cell apoptosis and reduces fibroblast proliferation.

STUDY DESIGN/MATERIALS AND METHODS

Keloid tissues were obtained from 10 patients with intralesional or punch biopsies prior to and 7 days after PDL treatments [fluence per pulse was 10-18 J/cm2 (mean 14 J/cm2)]. Prior to and after PDL treatments, the proliferating fibroblasts in keloid tissue were immunohistochemically detected by proliferating cell nuclear antigen (PCNA) expression. The apoptotic cell was detected by terminal deoxynucleotidyl transferase dUTP-nick end labeling (TUNEL) staining and fragmented caspase-3 expression. MAP kinase activation as represented by extracellular signal-regulated kinase (ERK), p38 kinase (p38), and c-Jun N-terminal kinase (JNK) expression of keloid tissues was investigated by immunohistochemical (IHC) staining, respectively.

RESULTS

IHC staining indicated that PCNA expression of fibroblasts was significantly reduced in keloid tissue after PDL irradiation. TUNEL assay revealed lower apoptotic cells expression in the keloid tissue prior to laser treatment. Following laser treatment, apoptotic cells with relatively strong DNA damage and fragmentation were seen in all keloid biopsy samples, especially in the keloid fibroblast population. The activation of ERK and p38 MAP kinase increased significantly in keloid tissue after PDL treatment. JNK was shown to be unchanged.

CONCLUSIONS

The PDL treatment is shown to induce keloid regression through suppression of keloid fibroblast proliferation, induction of apoptosis, and upregulation of ERK and p38 MAP kinase activity.

The utility of self-concept as a predictor of recidivism among juvenile offenders

Forty institutionalized male juvenile offenders in the United States were administered a Role Construct Repertory Grid (Kelly, 1955) and the Self-Consciousness Scale (Fenigstein, Scheier, & Buss, 1975) to determine whether frequent offenders could be differentiated from infrequent offenders on the basis of these instruments. We hypothesized that the frequent offenders would have more "delinquent" self-concepts than the infrequent offenders. The results did not confirm this hypothesis. In fact, the frequent offender group actually had fewer delinquent self-concepts than the offender group, although the trend was not statistically significant. This finding is interpreted as an indication that some offenders who acknowledge their delinquent orientation are better able to apply their personal resources toward control of their behavior.

Construction of Cu-Zn superoxide dismutase deletion mutants of Brucella abortus: analysis of survival in vitro in epithelial and phagocytic cells and in vivo in mice

Cu-Zn superoxide dismutase (SOD) deletion mutants of Brucella abortus S2308, a virulent strain, and S19, a vaccine strain, were generated by gene replacement. A deletion plasmid, pBA delta sodknr, was constructed by excising the Cu-Zn SOD gene (Cu-Zn sod) from a 2.3-kb B. abortus DNA fragment of plasmid pBA20-1527 and inserting a 1.4-kb DNA fragment encoding kanamycin resistance into the Cu-Zn sod excision site. The deletion plasmid was introduced into B. abortus by electroporation, and Southern blot analysis confirmed that the antibiotic resistance fragment had replaced Cu-Zn sod in kanamycin-resistant colonies. The survival and growth of Cu-Zn SOD mutant strains were compared with that of the parental strains in HeLa cells and in the mouse macrophagelike cell line J774. The survival and growth of the Cu-Zn SOD mutant strains were similar to those of their respective parental strains in HeLa and J774 cell lines. The kinetics of infection with these strains were examined in BALB/c mice. The splenic levels of the S19 Cu-Zn SOD mutant recovered from intraperitoneally infected BALB/c mice were approximately 10-fold lower than those of the parental strain through 26 days postinfection. Thereafter, infection sharply declined in both groups, and by 105 days postinfection, no organisms were detected. The splenic levels of the S2308 Cu-Zn SOD mutant were lower than those of wild-type S2308-infected mice. The spleen weights of mice infected with the S2308 Cu-Zn SOD mutant were consistently lower than those of wild-type S2308-infected mice. These results suggest that the antioxidant enzyme Cu-Zn SOD plays a role in the survival and pathogenicity of B. abortus in vivo.

Seroprevalence of ovine progressive pneumonia virus in sheep in the United States as assessed by analyses of voluntarily submitted samples

Ovine progressive pneumonia (OPP) is a lentivirus-induced disease of sheep in the United States that is similar, if not identical, to maedi/visna in many other countries. Prevalence estimates of seropositivity to this virus in sheep in the United States have been confined to limited groups or flocks of sheep and have varied from 1 to 90%. In this study of detection of antibodies against OPP virus, we found a lower general prevalence of antibodies to OPP virus in sheep than was previously reported. Of 16,827 sheep from 29 states in the United States, 26% were seropositive and 48% of 164 flocks that were tested had 1 or more seropositive sheep. Seropositivity to OPP virus for sheep within special categories was determined, although nonrandom samples that were available may have biased the results. Within regions of the United States, prevalence was highest in the Rocky Mountain region at 49% and lowest in the northern Atlantic region at 9%. Seropositive sheep were not evenly distributed among flocks, but were clustered in a few flocks of sheep. A high number of flocks had no or few seropositive sheep. Prevalence increased with age from 4% at less than 1 year to a plateau of 34% at 4 years. Seropositivity was variable among breeds and was not associated with sex, wool class, or place of origin of ancestors.

Prevalence of antibody to caprine arthritis-encephalitis virus in goats in the United States

Goats from 28 states were tested for antibodies to caprine arthritis-encephalitis virus. Of 3,790 goats, 1,175 (31%) tested positive, and of 196 herds tested, 143 (73%) had 1 or more seropositive members. This prevalence, based on serum samples from all goats in the participating herds, was lower than most rates reported in other studies. Such studies were based on fewer samples, incomplete sampling of herds, or smaller geographic base. Prevalence was highest in western Pacific and northern plains regions, increased with age to 3 years, was highest among goats on family-owned farms, and was lowest in the Angora breed. Differences in prevalence was not related to gender or size of herd.

Immunity induced in rats vaccinated with toxoid prepared from heat-labile toxin produced by Pasteurella multocida serogroup D

Rats were vaccinated with a toxoid (D-toxoid) prepared from purified heat-labile toxin (D-toxin) produced by Pasteurella multocida serogroup D. Vaccination of rats with D-toxoid prevented death and other effects of D-toxin (hepatic necrosis, development of elevated leukocyte counts, lymphopenia, neutrophilia, and elevated complement titers) that occurred in phosphate buffered saline (PBS)-vaccinated control rats.

Effects of adjuvant-augmented germling vaccines in turkey poults challenged with Aspergillus fumigatus

Turkey poults were vaccinated with combinations of two different germling preparations and three adjuvants (N-acetylmuranyl-L-alanyl-D-isoglutamine, Pasteurella multocida lipopolysaccharide [LPS], and avridine) at 1 and 2 weeks of age, and their immunity was challenged by sublethal exposure to aerosols of Aspergillus fumigatus conidia at 1 month of age. Fewer turkeys in the groups given vaccines prepared from germlings grown on Dorset's and Henley's medium (D&H) had organisms in lung tissue at 2 weeks after challenge exposure as compared with those vaccinated with germling grown on neopeptone dialysate (Neo). The LPS of P. multocida appeared to be the most efficacious of the adjuvants in the D&H vaccine group, as A. fumigatus was isolated from only one of eight turkeys in this group; the number of organisms per gram of lung tissue was low compared with other vaccine groups at 2 weeks after challenge exposure; and poults given D&H vaccine with LPS as adjuvant had less-severe lung lesions than other groups. These differences in lung lesions were more marked at 2 weeks than at 8 weeks after challenge exposure. The only difference among other parameters in the vaccinated turkeys was lower heterophil counts in the turkeys given D&H-prepared vaccines than in unvaccinated controls. This was probably due to less-severe infections resulting from protective effects of these vaccines.

Serologic survey for transmissible gastroenteritis virus neutralizing antibodies in selected feral and domestic swine sera in the southern United States

Serum samples collected from feral and domestic swine (Sus scrofa) in Florida and feral swine in Georgia and Texas were assayed by plaque reduction for their virus neutralizing (VN) antibodies against the porcine transmissible gastroenteritis virus (TGE). None of 560 samples collected from feral swine contained VN antibodies for TGE virus, but experimentally infected feral swine seroconverted. None of 665 samples from domestic swine contained TGE-VN antibodies. These results indicate feral swine are not a significant reservoir for TGE virus in southern states, but are capable of becoming infected and developing VN antibodies against TGE.

Prevalence and transmission of pseudorabies virus in an isolated population of feral swine

Six hundred sixty-one feral swine (Sus scrofa) from Ossabaw Island, Georgia (USA) were captured, bled, and their sera tested for pseudorabies virus (PRV) antibody during a 6 yr period. Prevalence of seroconversion in females was somewhat higher than in males (10% versus 7%), but the difference was not statistically significant. Adults had a significantly higher prevalence than juveniles (29% versus 1%). An important finding in this study was that seroconversion occurred primarily in the adult feral swine.

Complement, bacteriostatic, and enzymatic activities in sera from guinea pigs given aflatoxin and/or rubratoxin

The relationship of serum complement activity and bacteriostatic activity was investigated in male guinea pigs given aflatoxin and/or rubratoxin. In experiment 1, guinea pigs were given 0.6 mg of aflatoxin/kg of body weight, PO, once. In experiment 2, guinea pigs were given 0.02 mg of aflatoxin/kg, PO, and/or 8 mg of rubratoxin, PO, 11 times. Aflatoxin (0.02 mg/kg) had no effect given alone, but potentiated the effect of rubratoxin. In both experiments, changes in complement activity were accompanied by similar but not always significant (P less than 0.05) changes in bacteriostatic activity of serum. Guinea pigs given 0.06 mg of aflatoxin/kg had significant (P less than 0.05) changes in complement titers and in serum alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase activities. Guinea pigs given repeated oral doses of aflatoxin and/or rubratoxin had changes in complement titers, bacteriostasis, and alkaline phosphatase and aspartate aminotransferase activities, but not in alanine aminotransferase activities. Significant differences were detected only when average values for all guinea pigs given rubratoxin or rubratoxin with aflatoxin were compared with average values for guinea pigs not given rubratoxin.

Prevalence estimation from pooled samples

Under certain conditions, prevalence can be estimated by testing samples from individual members or by pooling samples from members into a group and by testing the sample from the group as a single unit. Pooled tests are more accurate than individual tests when P is less than 10%. Optimal group size is 1.6/P. Efficiency decreases slowly with suboptimal size and rapidly with overly large size.

Immunological surveillance in a pseudorabies quarantined herd using gilts and their progeny as sentinels

Specific pathogen free gilts and their progeny were evaluated to use as sentinels in a pseudorabies virus (PRV) infected herd by immunologically monitoring for PRV seroconversions. Time intervals targeted were pre- and post-PRV vaccinations, herd exposure, and farrowing to finishing. Post-PRV vaccinations, gilts showed low PRV lymphocyte stimulation and humoral responses. Following herd exposure, control gilts PRV seroconverted and PRV vaccinated gilts increased (2 to 4 times) in virus neutralization (VN) titers. Sixty-seven percent (4/6) of the progeny from a control gilt were PRV seropositive at finishing. Progeny from PRV vaccinated gilts were depleted of passive immunity by week 7, and were seronegative until week 9. At finishing 47% (14/30) of them were PRV seropositive indicating exposure to PRV. The VN test was not sensitive enough to detect weak positive serums, noted as positives by latex agglutination (LA) test, ELISA, and Western blots. The gilts and progeny detected PRV, respectively, in the herd housing quarters and in the farrow to finish facilities. A strategy for future sentinel experimental surveillances using primarily the LA test is proposed.

Development and evaluation of an enzyme-linked immunosorbent assay for bovine antibody (IgG) to Pasteurella haemolytica

The sensitivity of an indirect enzyme-linked immunosorbent assay (ELISA) for bovine IgG serum antibody to Pasteurella haemolytica was compared with that of an indirect hemagglutination (IHA) test. Pasteurella haemolytica serotypes were grown in a chemically defined cell culture medium, and soluble antigens released into the growth medium were used in the ELISA and IHA test. An ELISA with serotype-1 antigen consistently detected antibody in sera that were positive by IHA test (correlation, 99%). Sera reacting with serotype-1 ELISA antigens also reacted with ELISA antigens prepared from other serotypes. Although ELISA titers averaged 5 log2 units higher than IHA titers, plots of titers determined by the 2 methods were approximately linear. Titer increases detected in paired serum samples by either test were similar. The ELISA was more sensitive than was the IHA in detecting colostral IgG antibody in serum of newborn calves. The ELISA uses a simple, stable antigen preparation and detects antibody to P haemolytica serotypes that commonly infect cattle.

Development and evaluation of an enzyme-linked immunosorbent assay for bovine antibody to Pasteurella haemolytica: constructing an enzyme-linked immunosorbent assay titer

A 2-stage strategy was developed and evaluated for estimating serum antibody titer by use of ELISA and a series of dilutions. In stage 1, the linear response region and least-square estimate of the assay line slope were established from 9-point dilution assays. Provided that the reading was within the linear response region, this information was used in the stage-2 estimation of titer from a single absorbance reading. Operationally, 2 fixed dilutions were selected, one suitably low and one suitably high, to provide at least one reading within the linear region. The procedure should save considerable time when a large number of assays are to be performed. Stage 1 required approximately twenty 9-point assays, but all subsequent assays required only 2 fixed dilutions.

Frequency of association of noncytopathic bovine viral diarrhea virus with mononuclear leukocytes from persistently infected cattle

All mononuclear leukocytes and T lymphocyte-enriched and B lymphocyte-enriched subpopulations of mononuclear leukocytes collected from 8 cows persistently infected with 1 of 3 isolates of noncytopathic bovine viral diarrhea virus were tested for association with virus. For all persistently infected cows, approximately 4.4% of all mononuclear leukocytes, 5.4% of T lymphocyte-enriched, and 2.1% of B lymphocyte-enriched subpopulations of mononuclear leukocytes were associated with virus. Differences between leukocyte populations in percentages of leukocytes associated with virus were real (P less than 0.05). Among virus isolates, significant differences in percentages of leukocytes associated with virus were not detected.

Prevalence of Mycobacterium paratuberculosis in ileocecal lymph nodes of cattle culled in the United States

During 1983 and 1984, ileocecal lymph node specimens were obtained from clinically normal cattle at 76 US Department of Agriculture-inspected cull cattle slaughterhouses in 32 states and Puerto Rico. Mycobacterium paratuberculosis was isolated from the lymph nodes of 119 of 7,540 cattle. The prevalence of bovine paratuberculosis was 1.6% overall, with 2.9% in dairy culls and 0.8% in beef culls. The prevalence for females and males did not appear to differ significantly.

Characteristics of the homeless mentally disordered population in Fresno County

A survey of a sample comprising 9.5% of the estimated homeless mentally disordered population of Fresno County was conducted as a needs assessment for a treatment program proposal. Eighty percent of the sample were found to meet the criteria for a psychiatric diagnosis as determined by a standardized interview. Of these, 34% were rated severely impaired and urgently in need of treatment. An additional 33% were rated moderately impaired so that treatment would be of substantial benefit. Survey data are presented of the samples' priorities concerning primary needs, preferred locale for treatment and services, type of personnel with whom they would feel most comfortable, and most important problems.

Antiviral effectiveness of butylated hydroxytoluene against pseudorabies (Aujeszky's disease) virus in cell culture, mice, and swine

Butylated hydroxytoluene (BHT) was evaluated for antiviral effectiveness on pseudorabies virus (PRV) in cell culture, mice, and swine. When relatively small amounts of BHT were mixed with PRV and incubated at 37 C for 30 or 60 minutes before inoculation into cell cultures, the cell cultures did not become infected with virus. The PRV was not infectious when the virus was treated with BHT and then inoculated intraperitoneally into mice, but was infectious when BHT and PRV were inoculated simultaneously or when BHT was inoculated either 30 or 60 minutes before PRV. Swine fed BHT-medicated feed for 10 days before they were intranasally exposed with virulent PRV did not have overt signs of pseudorabies, had a lower concentration of PRV in nasal mucus than did control swine, and had acceptable blood enzyme and cholesterol concentrations during the experiment. The BHT was detected in tissues of 2 swine after they were fed BHT-medicated feed for 10 days, and higher concentrations of BHT were detected in tissues of 3 swine given BHT feed for 29 days.

Breed susceptibility to ovine progressive pneumonia (maedi/visna) virus

In this retrospective study of breed differences in susceptibility to disease caused by ovine progressive pneumonia (OPP) virus, 29 Border Leicester sheep were compared with 46 Columbia sheep. As judged by frequency and severity of clinical signs and lesions attributable to the infection, Border Leicester sheep were markedly more susceptible than Columbia sheep and experimentally infected sheep were slightly more susceptible than naturally infected sheep. Differences in susceptibility to infection by the virus were not determined.

Decreased complement and bacteriostatic activities in the sera of cattle given single or multiple doses of aflatoxin

Five steers given 1 dose of partially purified aflatoxin at concentrations sufficient to provide 0.2 mg to 0.8 mg of aflatoxin B1 equivalents/kg of body weight were compared with 4 steers given 14 daily doses of 0.25 mg of aflatoxin B1 equivalents/kg of body weight for complement activity and bacteriostasis. Complement activity was measured by hemolysis in gel, and bacteriostatic activity, by growth inhibition of Escherichia coli in liquid medium. In the single-dose group, complement activity and bacteriostatic activities decreased by 57 hours after dosing, and both returned to near base line by 168 hours. In the daily dose group, only bacteriostatic activity decreased, and the decrease persisted 2 weeks after the last dose of aflatoxin was given. Apparently, aflatoxin affects both complement-dependent and independent serum bacteriostatic activity.