Antibodies in sera from newly diagnosed insulin-dependent diabetes mellitus (IDDM) patients are directed to a human islet cell protein of relative molecular mass (Mr) 64,000. Since Il)DM seems to develop after a prodromal period of,8-cell autoimmunity, this study has examined whether 64,000 Mr antibodies could be detected in 14 individuals who subsequently developed IDDM and five first degree relatives who have indications of altered (3-cell function. Sera were screened by immunoprecipitation on total detergent lysates of human islets and positive sera retested on membrane protein preparations. Antibodies to the 64,000 Mr membrane protein were consistently detected in 11/14 IDDM patients, and in all 5 first degree relatives. 10 IDDM patients were already positive in the first samples, obtained 4-91 mo before the clinical onset of IDIM, whereas 1 patient progressed to a high 64,000 M, immunoreactivity, at a time where a commencement of a decline in (3-cell function was detected. 64,000 M, antibodies were detected before islet cell cytoplasmic antibodies (ICCA) in two patients. In the control groups of 21 healthy individuals, 36 patients with diseases of the thyroid and 5 SLE patients, the 64,000 Mr antibodies were detected in only one individual, who was a healthy sibling to an IDDM patient. These results suggest that antibodies against the Mr 64,000 human islet protein are an early marker of (-cell autoimmunity and may be useful to predict a later development of IDDM.

Furanones may inhibit biofilm formation through interference with quorum sensing and thus represent promising agents for protecting surfaces from being colonized by S. epidermidis.

In a matter of a few days the murine tooth germ develops into a complex, mineralized, structure. Murine 30K microarrays were used to examine gene expression in the mandibular first molar tooth germs isolated at 15.5dpc and at 2DPN. Microarray results were validated using real-time RT-PCR. The results suggested that only 25 genes (3 without known functions) exhibited significantly higher expression at 15.5dpc compared to 2DPN. In contrast, almost 1400 genes exhibited significantly (P<0.015) higher expression at 2DPN compared to 15.5dpc, about half of which were genes with unknown functions. More than 50 of the 783 known genes exhibited higher than 10-fold increase in expression at 2DPN, amongst these were genes coding for enamel matrix proteins which were expressed several 100-fold higher at 2DPN. GO and KEGG analysis showed highly significant associations between families of the 783 known genes and cellular functions relating to energy metabolism, protein metabolism, regulation of cell division, cell growth and apoptosis. The use of bioinformatics analysis therefore yielded a functional profile in agreement with known differences in tissue morphology and cellular composition between these two stages. Such data is therefore useful in directing attention towards genes, or cellular activities, which likely are worthy of further studies as regards their involvement in odontogenesis.

The aim of this study was to describe the expression of genes, including ameloblastin (Ambn), amelogenin X chromosome (Amelx), and enamelin (Enam) during early (pre-secretory) tooth development. The expression of these genes has predominantly been studied at post-secretory stages. Deoxyoligonucleotide microarrays were used to study gene expression during development of the murine first molar tooth germ at 24 h intervals, starting at the 11th embryonic day (E11.5), and up to the 7th day after birth (P7). The profile search function of Spotfire software was used to select genes with similar expression profile as the enamel genes (Ambn, Amelx, and Enam). Microarray results where validated using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), and translated proteins identified by Western-blotting. In situ localization of the Ambn, Amelx, and Enam mRNAs were monitored from E12.5 to E17.5 using deoxyoligonucleotide probes. Bioinformatics analysis was used to associate biological functions with differentially expressed (DE; p ≤ 0.05) genes. Microarray results showed a total of 4362 genes including Ambn, Amelx, and Enam to be significant DE throughout the time-course. The expression of the three enamel genes was low at pre-natal stages (E11.5–P0) increasing after birth (P1–P7). Profile search lead to isolation of 87 genes with significantly similar expression to the three enamel proteins. These mRNAs were expressed in dental epithelium and epithelium derived cells. Although expression of Ambn, Amelx, and Enam were lower during early tooth development compared to secretory stages enamel proteins were detectable by Western-blotting. Bioinformatic analysis associated the 87 genes with multiple biological functions. Around 35 genes were associated with 15 transcription factors.

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The aim of this study was to develop a three-dimensional porous bone graft material as vehicle for simvastatin delivery and to investigate its effect on primary human osteoblasts from three donors. Highly porous titanium dioxide (TiO2) scaffolds were submerged into simvastatin containing alginate solution. Microstructure of scaffolds, visualized by scanning electron microscopy and micro-computed tomography, revealed an evenly distributed alginate layer covering the surface of TiO2 scaffold struts. Progressive and sustained simvastatin release was observed for up to 19 days. No cytotoxic effects on osteoblasts were observed by scaffolds with simvastatin when compared to scaffolds without simvastatin. Expression of osteoblast markers (collagen type I alpha 1, alkaline phosphatase, bone morphogenetic protein 2, osteoprotegerin, vascular endothelial growth factor A and osteocalcin) was quantified using real-time reverse transcriptase–polymerase chain reaction. Secretion of osteoprotegerin, vascular endothelial growth factor A and osteocalcin was analysed by multiplex immunoassay (Luminex). The relative expression and secretion of osteocalcin was significantly increased by cells cultured on scaffolds with 10 µM simvastatin when compared to scaffolds without simvastatin after 21 days. In addition, secretion of vascular endothelial growth factor A was significantly enhanced from cells cultured on scaffolds with both 10 nM and 10 µM simvastatin when compared to scaffolds without simvastatin at day 21. In conclusion, the results indicate that simvastatin-coated TiO2 scaffolds can support a sustained release of simvastatin and induce osteoblast differentiation. The combination of the physical properties of TiO2 scaffolds with the osteogenic effect of simvastatin may represent a new strategy for bone regeneration in defects where immediate load is wanted or unavailable.

No abstract

Enamel matrix derivative (EMD) has been found to induce reactive dentin formation; however the molecular mechanisms involved are unclear. The effect of EMD (5–50 μg/mL) on primary human pulp cells were compared to untreated cells and cells incubated with 10−8 M dexamethasone (DEX) for 1, 2, 3, 7, and 14 days in culture. Expression analysis using Affymetrix microchips demonstrated that 10 μg/mL EMD regulated several hundred genes and stimulated the gene expression of proteins involved in mesenchymal proliferation and differentiation. Both EMD and DEX enhanced the expression of amelogenin (amel), and the dentinogenic markers dentin sialophosphoprotein (DSSP) and dentin matrix acidic phosphoprotein 1 (DMP1), as well as the osteogenic markers osteocalcin (OC, BGLAP) and collagen type 1 (COL1A1). Whereas, only EMD had effect on alkaline phosphatase (ALP) mRNA expression, the stimulatory effect were verified by enhanced secretion of OC and COL1A from EMD treated cells, and increased ALP activity in cell culture medium after EMD treatment. Increased levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemoattractant proteins (MCP-1) in the cell culture medium were also found. Consequently, the suggested effect of EMD is to promote differentiation of pulp cells and increases the potential for pulpal mineralization to favor reactive dentine formation.