Endodontic treatment of canine teeth in a cynomolgus monkey ( Macaca fascicularis).

A case of bilateral superior canine tooth pulp necrosis in an 18-year-old male Macaca fascicularis is described . A skull computed tomography scan was performed to confirm the diagnostic suspicion. A successful bilateral endodontic treatment with coronotomy was performed using rotary nickel-titanium instruments. Post-operative dental radiographs confirmed the correct positioning of the sealant. A rapid and excellent clinical recovery was obtained after each surgery. This innovative approach may contribute to improving the quality of root canal treatments provided to non-human primates.

In vitro and in vivo effects of the carbon monoxide-releasing molecule, CORM-3, in the xenogeneic pig-to-primate context.

BACKGROUND: Carbon monoxide (CO) interferes with inflammatory and apoptotic processes associated with ischemia-reperfusion injury and graft rejection. Here, the in vitro effects of carbon monoxide releasing molecule-3 (CORM-3), a novel water-soluble carbonyl CO carrier, have been investigated on porcine aortic endothelial cells (PAEC) and primate peripheral blood mononuclear cells (PBMC). Furthermore, the pharmacodynamics and pharmacotolerance of CORM-3 after administration of single and multiple doses in the primate have been assessed in view of its potential application in pig-to-primate xenotransplantation models. METHODS: For in vitro studies, PAEC and primate PBMC were exposed for 24, 48 and 72 h to CORM-3 (20 to 1000 microm) and viability was measured using an MTS assay. PAEC and primate PBMC proliferation after exposure to CORM-3 was assessed by CFSE labelling. Proliferation of primate PBMC against irradiated pig lymphocytes was also assessed. Tumor necrosis factor alpha (TNF-alpha) production and Caspase-3 and -7 activity in Concanavalin A (conA)-stimulated primate PBMC were measured following treatment with CORM-3. In vivo, CORM-3 was administered i.v. to cynomolgus monkeys at 4 mg/kg, as single or multiple doses for up to 30 days. The effect of CORM-3 was evaluated by the assessment of production of TNF-alpha and interleukin 1beta following PBMC stimulation with LPS by species-specific ELISA. Complete hematologic and biochemical analyses were routinely performed in treated primates. RESULTS: At concentrations <500 microm, CORM-3 did not alter the viability of PAEC or primate PBMC cultures in vitro, nor did it induce significant levels of apoptosis or necrosis. Interestingly, at concentrations of 300 and 500 microm, significant PAEC proliferation was observed, whilst concentrations > or =50 microm inhibited conA-activated primate lymphocyte proliferation (IC(50) of 345.8 +/- 51.9 microm) and the primate xenogeneic response against pig PBMC. Such responses were demonstrated to be CO-dependent. In addition, CORM-3 significantly inhibited caspase-3 and -7 activity at concentrations between 200 and 500 microm and caused a significant reduction in TNF-alpha production (IC(50) 332.8 +/- 33.9 microm). In vivo, following the administration of multiple doses, TNF-alpha production was significantly reduced in comparison to pre-treatment responses, with decreased levels maintained throughout the study. Moreover, a slight and transient increase in transaminases and bilirubin was observed in animals exposed to multiple doses of CORM-3. CONCLUSIONS: These studies suggest that CORM-3 has anti-inflammatory and immunomodulatory properties in primates that may result in clinical benefit to allo- and xenografted organs.

Heterotopic cardiac xenotransplantation in rodents: report of a refined technique in a hamster-to-rat model.

Hamster-to-rat heterotopic cardiac xenotransplantation is widely used as an experimental model to study xenograft rejection, accommodation, and tolerance, as well as in studies aimed at developing immunosuppressive strategies in xenotransplantation. Despite its widespread application, no detailed description of a surgical technique for this model has been provided in the literature. Indeed, all publications so far on the use of this species combination refer to the rat allotransplantation technique. Hence the present paper provides a detailed, up-to-date description of the surgical method adopted at our center for the hamster-to-rat heterotopic cardiac xenotransplantation model. Considerable effort went into developing a reliable, reproducible experimental model in rodents, and the description given here is enriched with "tips" that we learned in the process. The discussion of the technique also addresses several significant related issues, e.g., the anesthesia and organ preservation solution used (aspects that, in our experience, are crucial to a good surgical outcome).

Methotrexate for immunosuppression in life-supporting pig-to-cynomolgus monkey renal xenotransplantation.

Methotrexate (MTX) has been used successfully as an immunosuppressant in rodent xenotransplantation models, but the data generated so far with MTX in pig-to-baboon cardiac transplantation studies have been disappointing. The potential of this agent was consequently explored in a life-supporting pig-to-primate renal model using the cynomolgus monkey as the recipient species. Introductory in vitro and in vivo pharmacokinetic and pharmacodynamic studies with MTX were conducted in three cynomolgus monkeys. Subsequently, 10 cynomolgus monkey recipients of a life-supporting kidney from human decay-accelerating factor transgenic pigs were administered MTX intravenously according to three different regimens. All the animals also received cyclosporine A and steroids. In addition, mycophenolate sodium (MPS) was administered post-operatively in two of the three groups of transplanted animals. At clinically relevant concentrations, MTX is able in vitro to inhibit the mixed lymphocyte reactions (MLR) in cynomolgus monkeys. After intravenous administration, moreover, exposure of cynomolgus monkeys to MTX appeared to be higher than had been previously reported in baboons. Graft function was observed in the transplanted animals, which survived from 0 to 41 days. All but two animals revealed acute humoral rejection in the explanted graft and developed diarrhea. Diarrhea was the cause of euthanasia in five cases. It was unrelated to the administration of MPS and associated with severe histopathological signs of enteritis. This study demonstrates that the pharmacokinetic and pharmacodynamic profiles if MTX vary substantially between non-human primate species. In vitro, MTX has immunosuppressive properties in the cynomolgus monkey at clinically relevant concentrations. In vivo, MTX has a very narrow therapeutic window in cynomolgus monkeys, however, as it does in baboons. We conclude that MTX is scarcely effective as an immunosuppressant, be it for induction or maintenance, in pig-to-cynomolgus monkey renal xenotransplantation.