Constitutive expression of the anti-apoptotic Bcl-2 family member A1 in murine endothelial cells leads to transplant tolerance.

Anti-apoptotic genes, including those of the Bcl-2 family, have been shown to have dual functionality inasmuch as they inhibit cell death but also regulate inflammation. Several anti-apoptotic molecules have been associated with endothelial cell (EC) survival following transplantation; however, their exact role has yet to be elucidated in respect to controlling inflammation. In this study we created mice expressing murine A1 (Bfl-1), a Bcl-2 family member, under the control of the human intercellular adhesion molecule 2 (ICAM-2) promoter. Constitutive expression of A1 in murine vascular ECs conferred protection from cell death induced by the proinflammatory cytokine tumour necrosis factor (TNF)-α. Importantly, in a mouse model of heart allograft transplantation, expression of A1 in vascular endothelium increased survival in the absence of CD8+ T cells. Better graft outcome in mice receiving an A1 transgenic heart correlated with a reduced immune infiltration, which may be related to increased EC survival and reduced expression of adhesion molecules on ECs. In conclusion, constitutive expression of the anti-apoptotic molecule Bfl1 (A1) in murine vascular ECs leads to prolonged allograft survival due to modifying inflammation.

Immunotoxin Against a Donor MHC Class II Molecule Induces Indefinite Survival of Murine Kidney Allografts.

Rejection of donor organs depends on the trafficking of donor passenger leukocytes to the secondary lymphoid organs of the recipient to elicit an immune response via the direct antigen presentation pathway. Therefore, the depletion of passenger leukocytes may be clinically applicable as a strategy to improve graft survival. Because major histocompatibility complex (MHC) class II(+) cells are most efficient at inducing immune responses, selective depletion of this population from donor grafts may dampen the alloimmune response and prolong graft survival. In a fully MHC mismatched mouse kidney allograft model, we describe the synthesis of an immunotoxin, consisting of the F(ab')2 fragment of a monoclonal antibody against the donor MHC class II molecule I-A(k) conjugated with the plant-derived ribosomal inactivating protein gelonin. This anti-I-A(k) gelonin immunotoxin depletes I-A(k) expressing cells specifically in vitro and in vivo. When given to recipients of kidney allografts, it resulted in indefinite graft survival with normal graft function, presence of Foxp3(+) cells within donor grafts, diminished donor-specific antibody formation, and delayed rejection of subsequent donor-type skin grafts. Strategies aimed at the donor arm of the immune system using agents such as immunotoxins may be a useful adjuvant to existing recipient-orientated immunosuppression.

An Extraperitoneal Technique for Murine Heterotopic Cardiac Transplantation.

The mouse heterotopic cardiac transplantation model has been used extensively by investigators in the field of organ transplantation to study the rejection process, test new antirejection treatments, tolerance induction protocols or to understand basic immunological principles. Due to its extensive use, any small refinement of the technique would have a major impact on replacement, reduction and refinement (commonly known as the 3Rs). Here, we describe a novel approach to refine this model. The donor aorta and pulmonary artery are anastomosed peripherally to the femoral artery and vein of the recipient, respectively. The technical success rate is comparable to the conventional abdominal site, but it avoids a laparotomy and handling of the bowels making it less invasive method. As a result, recipients recover faster and require less postoperative analgesia. It is a major refinement under one of the 3Rs and would represent an advance in animal welfare in scientific research.

Noninvasive Imaging of Activated Complement in Ischemia-Reperfusion Injury Post-Cardiac Transplant.

Ischemia-reperfusion injury (IRI) is inevitable in solid organ transplantation, due to the transplanted organ being ischemic for prolonged periods prior to transplantation followed by reperfusion. The complement molecule C3 is present in the circulation and is also synthesized by tissue parenchyma in early response to IRI and the final stable fragment of activated C3, C3d, can be detected on injured tissue for several days post-IRI. Complement activation post-IRI was monitored noninvasively by single photon emission computed tomography (SPECT) and CT using (99m) Tc-recombinant complement receptor 2 ((99m) Tc-rCR2) in murine models of cardiac transplantation following the induction of IRI and compared to (99m) Tc-rCR2 in C3(-/-) mice or with the irrelevant protein (99m) Tc-prostate-specific membrane antigen antibody fragment (PSMA). Significant uptake with (99m) Tc-rCR2 was observed as compared to C3(-/-) or (99m) Tc-PSMA. In addition, the transplanted heart to muscle ratio of (99m) Tc-rCR2 was significantly higher than (99m) Tc-PSMA or C3(-/-) . The results were confirmed by histology and autoradiography. (99m) Tc-rCR2 can be used for noninvasive detection of activated complement and in future may be used to quantify the severity of transplant damage due to complement activation postreperfusion.

Gastrointestinal parasites of mountain gorillas (Gorilla gorilla beringei) in the Parc National des Volcans, Rwanda.

Ninety-eight fecal samples were collected from 74 free-living mountain gorillas (Gorilla gorilla beringei) from the Parc National des Volcans, Rwanda, between July 1995 and January 1997 and examined for parasites by Sheather's sugar and zinc sulfate flotation methods, trichrome staining, and larval cultures. All samples contained at least one parasite. Seventeen endoparasites were identified, including eight protozoa, seven nematodes, one cestode, and one trematode. Two species of arthropod mite were also recovered from the fecal samples. Parasites observed on fecal examinations included strongyle/trichostrongyle-type eggs (72/74) (representing Oesphagostomum sp., Trichostrongylus sp., Hyostrongylus spp., and possibly Murshidia sp.), Strongyloides sp. (1/74), Trichuris trichiura (2/74), Probstmayria sp. (7/74), Anoplocephala sp. (63/74), Entamoeba hartmanni cysts and trophozoites (19/70), Endolimax nana cysts (31/70), Iodamoeba buetschlii cysts (11/70), Endolimax nana or Iodamoeba buetschlii trophozoites (63/70). Entamoeba coli cysts and trophozoites (14/70), Entamoeba histolytica trophozoite (1/70), Chilomastix sp. cysts and trophozoites (31/70), and Giardia sp. cysts (2/70). In addition, one ascarid and one trematode egg were seen. There were no significant differences in the prevalence of parasites between males and females and between age groups: however, infants and juveniles appeared to have a lower prevalence of Anoplocephala gorillae, and the silverbacked males appeared to have a higher prevalence of Probstmayria sp. Parasite prevalence was consistent among the five social groups studied except Susa group had a significantly lower prevalence of Anoplocephala gorillae. Trichuris trichiura, Strongyloides sp., Chilomastix sp., and Endolimax nana were identified for the first time in this population, and it is possible that these parasites were of human origin. Although there were no obvious clinical effects due to the presence of these parasites, six parasites identified (Trichuris trichiura, Strongyloides sp., Oesphagostomum sp., Trichostrongylus sp., Entamoeba histolytica, and Giardia sp.) could potentially be pathogenic. Some of the parasite products and cultured larvae could not be speciated.

Cephalometric evaluation of the changes in patients wearing complete dentures: a 20-year study.

The purpose of this continuing longitudinal investigation was to study the changes on the craniofacial complex in complete denture wearers; herein are reported the 20-year findings. At the onset of the study complete dentures were made for 64 persons. Two dentures techniques were employed: a complex method of construction and a simplified method. At the start of the project the patients' ages ranged from 30 to 60 years (average age 53 years) and all had been edentulous for at least 1 year (range 1 to 30 years). Lateral cephalometric radiographs were made immediately after initial placement of the dentures and during subsequent years (1, 2, 3, 4, 5, 7, 10, 15, and 20). The same cephalostat was used throughout and all films were exposed with the teeth in centric occlusion. Thirty-four subjects presented for the 20-year follow-up. Of this number, the radiographs of 24 subjects (14 women and 10 men; average age 65.5 years [range 50-83 years]) (12 complex denture wearers; 12 simplified technique denture wearers) were used in this report (10 had denture alterations over the 20-year period that excluded them). The 20-year observations corroborate earlier findings. There is a loss of the vertical dimension of occlusion as viewed from the right profile, and the mandible rotates in a counterclockwise fashion resulting in an increase in relative prognathism. The maxillary alveolus was stable, the mandibular alveolus resorbed, and the dentures rotated counterclockwise and shifted slightly forward. The observed changes were not significantly affected by the sex of the patient or by the denture technique employed.