The medial meniscus was resected from the right knees of twelve young grivet monkeys that were killed at intervals of twenty-one to 252 days after operation. The knees operated upon and the control knees were investigated radiologically and histologically. Degenerative changes occurred in the medial femoral and tibial condyles. At first there was loss of cells from the superficial layer of the articular cartilage, with a marked decrease in the acid mucopolysaccharide content of the matrix. The chondrocytes in the deeper layer of the non-calcified zone proliferated to form clones before finally degenerating. The acellular cartilage showed splitting, and with progress of the degenerative process there was thinning and erosion of the cartilage. Eventually there was complete loss of articular cartilage with thickening and exposure of the subchondral bone. These degenerative changes were confined to a small area of the articular cartilage and had occurred despite regeneration of the meniscus. The rest of the cartilage looked normal. It is concluded that articular cartilage deprived of the protection of a meniscus may undergo arthritic changes.

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Background: The biological examination of pulp injury, repair events and response of dental pulp stem cells to dental restorative materials is important to accomplish restorative treatment, especially to commonly used dental materials in paediatric dentistry, such as glass ionomer cement (GIC) and calcium hydroxide (Ca(OH) 2 ) lining cement. Methods: Healthy patients aged between 9 to 11 years with carious primary molars without pulp exposure were selected and divided into two groups: Group 1 (teeth restored with GIC) and Group 2 (teeth lined using Ca(OH) 2 and restored with GIC). The proliferative activity of stem cells of teeth between these two groups was compared using colourimetric cell proliferation reagent, alamarBlue. Immunocytochemistry and flow cytometry confirmation were performed using mesenchymal stem cell markers, CD105 and CD166. Results: The proliferative activity using alamarBlue TM assay showed that cells derived from the remaining dental pulp of exfoliated deciduous teeth were positive for CD105 and CD166 and exhibited no difference between the two groups. Conclusions: It can be concluded that the use of Ca(OH) 2 or GIC as a lining material in indirect pulp capping procedures has the same effect on cells derived from the remaining dental pulp of exfoliated deciduous teeth which have responded favourably to the restorative treatments.

Genetic diversities in two cultured oyster species, Crassostrea iredalei (Faustino 1932) and Crassostrea belcheri (Sowerby 1871) were assessed using a 581-nucleotide fragment of the mtDNA cytochrome oxidase subunit 1 (CO1) gene. A total of 103 C. iredalei individuals and 120 C. belcheri from 12 populations were sampled along the coast of Malaysia. Trees of unique haplotype samples generated based on Neighbor-Joining (NJ) algorithm revealed that many individuals had been misidentified and did not cluster with their presumed species based on morphological identification. BLAST results of DNA sequences showed presence of previously unreported C. madrasensis in Peninsular Malaysian waters (98% maximum identity). The true identity of the Muar (Crassostrea sp.) and Semporna (Saccostrea sp.) populations were unresolved by two BLAST search and showed less than 88% identity with other species in GenBank. Repeated analysis of these two populations using 487 bp of the mitochondrial 16S gene data showed only a maximum identity less than 97%. Hence, the identity of these specimens remains unclear. Evolutionary divergences within presumed species were 0.001-0.011 and 0.034-0.313 between species. Findings from this study have important implications for aquaculture, management and monitoring of cultured populations as well as conservation of wild oyster species in Malaysia.