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The cell occlusive effects on human gingival fibroblasts of degradable lactic acid-glycolic acid copolymer membranes (noncoated membranes) and membranes coated with a sucrose ester of fatty acid (coated membranes) were studied and compared with those of expanded polytetrafluoroethylene (e-PTFE) membranes. The membranes were immersed in a culture medium periodically for 21 days and interposed into a chemotaxis chamber, and the fibroblasts then were cultured in the chamber for another 7 days. The passage rate of cells through the membranes was calculated and the change in surface structure of each membrane after immersion for 28 days was observed by an environmental scanning electron microscope. The passage rate of coated membranes (3.4+/-2.2%) was significantly lower than that of noncoated (25.7+/-5.1%) at the 28th day whereas the passage rate of e-PTFE membranes was 0.8-1.5%. Many pores were observed on the noncoated membranes before immersion while the coating material covered most of the pores on the coated membranes. The average pore size of the noncoated membranes was larger than that of the coated membranes at day 28. The structure of the e-PTFE membranes underwent no change. The passage rate of the coated membranes was not different from the e-PTFE membranes, suggesting an effect that might be useful for a guided tissue regeneration procedure.

The male-enhanced antigen-1 (Mea-1) gene was previously isolated from a bovine testicular cDNA library. In the present study, we cloned the full-length bovine genomic Mea-1 gene and compared this with the Mea-1 cDNA. The 1035-nucleotide bovine mRNA for Mea-1 (excluding the poly (A) tail) is encoded in three exons distributed over 3123 base pairs of the genome. Analysis of the 5' flanking sequence by primer extension mapping identified two main transcription start sites and several minor ones. The 5' region contained transcription-related sequences such as TATA/CAAT boxes, GC-rich regions, and several cis elements. When chloramphenicol acetyltransferase (CAT) activities of 5'-deleted clones were measured in CHO, TM4, and BALB/3T3 cells, a critical region for transcription was identified around -249 to -113 bp region from transcription start site. In situ hybridization and immunohistochemistry indicate that transcripts of the Mea-1 gene were localized in primary and secondary spermatocytes, and spermatids, but the protein products were detected only in spermatids. Intensive transcription of Mea-1 gene and specific localization of the gene product suggest that Mea-1 may play a important role in the late stage of spermatogenesis.

We previously reported that materials leached from bioactive glass (BG) and vitamin D3 induced the formation of nodules on cultured periodontal-ligament fibroblasts (PLF). In this study, we have investigated the relationship between the conditions of the materials and nodule formation, analyzed morphologically, and also studied whether the production of nodules was specific to cultured PLF. PLF and skin fibroblasts were cultured in the presence or absence of BG. The amounts of calcium, phosphate, sodium and silicon in the culture medium and the number of nodules were measured at the 55th day. The nodules were observed microscopically and analyzed using an X-ray microanalyzer. In PLF, nodules were formed regardless of the presence or absence of BG; however, they were more numerous in the presence of BG. In skin fibroblasts, nodules were not observed. The amounts of calcium and silicon were higher in the presence of BG, while the amount of phosphate was lower. The nodules appeared crystalline with a spongy structure and contained calcium and phosphorus. Our results show that the nodules were associated with PLF and precipitated by the materials (higher concentrations of calcium and silicon), and they were spongy crystal composed of calcium and phosphorus.

The effects of bioactive glass and vitamin D3 on cultured fibroblasts derived from periodontal-ligament, with respect to their proliferation and alkaline-phosphatase activity were studied. The cells were cultured with or without the bioactive glass and/or vitamin D3, then the number and alkaline-phosphatase activity of the cells were measured periodically until the 33rd day. Formation of mineralized deposits was assessed by staining with alizarin red and von Kossa staining techniques. Fewer fibroblasts grew when they were cultured in the presence of bioactive glass and/or vitamin D3 as compared to those cultures without them. Alkaline-phosphatase activity was greater in the fibroblasts cultured with bioactive glass and vitamin D3 than in the cells grown without them. Mineralized deposits assessed by alizarin red and von Kossa staining techniques were observed microscopically around the fibroblasts cultured with bioactive glass and/or vitamin D3. A nodule visible after drying was evident only when both bioactive glass and vitamin D3 were present in culture. The results showed that although the bioactive glass and vitamin D3 decreased cell proliferation, they increased the alkaline-phosphatase activity of the fibroblasts which formed a nodule, suggesting an effect which might be useful for implant materials.