Dental microwear texture analysis of two families of subfossil lemurs from Madagascar.

This study employs dental microwear texture analysis to reconstruct the diets of two families of subfossil lemurs from Madagascar, the archaeolemurids and megaladapids. This technique is based on three-dimensional surface measurements utilizing a white-light confocal profiler and scale-sensitive fractal analysis. Data were recorded for six texture variables previously used successfully to distinguish between living primates with known dietary differences. Statistical analyses revealed that the archaeolemurids and megaladapids have overlapping microwear texture signatures, suggesting that the two families occasionally depended on resources with similar mechanical properties. Even so, moderate variation in most attributes is evident, and results suggest potential differences in the foods consumed by the two families. The microwear pattern for the megaladapids indicates a preference for tougher foods, such as many leaves, while that of the archaeolemurids is consistent with the consumption of harder foods. The results also indicate some intraspecific differences among taxa within each family. This evidence suggests that the archaeolemurids and megaladapids, like many living primates, likely consumed a variety of food types.

Characterization of host response, resorption, and strength properties, and performance in the presence of bacteria for fully absorbable biomaterials for soft tissue repair.

PURPOSE: The objective was to evaluate the host response, resorption, and strength properties, and to assess the performance in the presence of bacteria for Phasix™ Mesh (Phasix™) and Gore® Bio-A® Tissue Reinforcement (Bio-A®) in preclinical models. METHODS: In a rat model, one mesh (2 × 2 cm) was implanted subcutaneously in n = 60 rats. Animals were euthanized after 2, 4, 8, 12, 16, or 24 weeks (n = 5/mesh/time point), and implant sites were assessed for host inflammatory response and overall fibrotic repair thickness. In a rabbit model, meshes (3.8 cm diameter) were bilaterally implanted in subcutaneous pockets in n = 20 rabbits (n = 10 rabbits/mesh) and inoculated with 108 CFU clinically isolated methicillin-resistant Staphylococcus aureus (MRSA). One mesh type was implanted per animal. Animals were euthanized after 7 days, and implants were assessed for abscess formation, bacterial colonization, and mechanical strength. RESULTS: In the rat study, Phasix™ and Bio-A® exhibited similar biocompatibility, although Bio-A® demonstrated a significantly greater inflammatory response at 4 weeks compared to Phasix™ (p < 0.01). Morphometric analysis demonstrated rapid resorption of Bio-A® implants with initially thicker repair sites at 2, 4, 8, and 12 weeks (p < 0.0001), which transitioned to significantly thinner sites compared to Phasix™ at 16 and 24 weeks (p < 0.0001). In the rabbit bacterial inoculation study, Phasix™ exhibited significantly lower abscess score (p < 0.001) and bacterial colonization (p < 0.01), with significantly greater mechanical strength than Bio-A® (p < 0.001). CONCLUSIONS: Host response, resorption, repair thickness, strength, and bacterial colonization suggest a more stable and favorable outcome for monofilament, macroporous devices such as Phasix™ relative to multifilament, microporous devices such as Bio-A® over time.

The gamete and embryo compatibility of various synthetic polymers.

Several popular and well-characterized polymeric materials were evaluated for their biocompatibility toward the cells unique to reproduction. To accomplish these studies, several in vitro tests were developed that evaluated biocompatibility between the polymers and spermatozoa, ova, and embryos. The data indicated significant differences between the materials with respect to their biocompatibility toward sperm motility, the sperm's ability to penetrate zona-free hamster eggs, and the ability of two-cell mouse embryos to divide. Polytetrafluoroethylene (PTFE-Teflon; PTFE, Chemplast Inc., Wayne, NJ), polyethylene glycol (PEG), and polyhydroxyethyl methacrylate (PHEMA) appear to be the most inert of the materials studied. Polyvinyl chloride (PVC; Tygon-Norton, Akron, OH) was found to be the most detrimental material toward gametes and embryos, with gross physiologic and morphologic changes observed in the PVC-exposed cells.

Pregnancies following implantation of an artificial fallopian tube in rabbits.

The first cases of pregnancies obtained in vivo in animals after implantation of a Teflon artificial fallopian tube model are presented. The Teflon prosthesis was implanted into the uterine cornua of rabbits and fixed subcutaneously in the abdominal wall. Five to eight blastocysts obtained from donor rabbits were transferred through the tubing into each recipient animal's uterus 2 to 14 days after placement of the device. On posttransfer day 10, normally developed pregnancies were visible and confirmed histologically in 4 of 7 animals.