[Possibility of minimizing capital costs for organization of sanitary protection zone of enterprise].

The article covers topic of sanitary protection zones, from a viewpoint of decided ecologic solutions and economic content, and approach to calculation of the most optimal correlation between them.

[Soil pollution influenced by chemical hazards releases into atmosphere].

The article covers a problem of soil pollution degree, that can be caused by industrial releases into atmosphere.

[Possibilities to minimize fundamental expenses for organizing sanitary protective zone of enterprise].

The article covers problem of sanitary protective zones, from a viewpoint of present ecologic decisions and economic contents, and approach to calculation of more optimal relationships between them.

Targeted disruption of two small leucine-rich proteoglycans, biglycan and decorin, excerpts divergent effects on enamel and dentin formation.

Small leucine-rich proteoglycans have been suggested to affect mineralization of dental hard tissues. To determine the functions of two of these small proteoglycans during the early stages of tooth formation, we characterized the dental phenotypes of biglycan (BGN KO) and decorin deficient (DCN KO) mice and compared them to that of wild type mice. Each targeted gene disruption resulted in specific effects on dentin and enamel formation. Dentin was hypomineralized in both knock out mice, although the effect was more prominent in the absence of decorin. Enamel formation was dramatically increased in newborn biglycan knockout mice but delayed in absence of decorin. Increased enamel formation in the former case resulted from an upregulation of amelogenin synthesis whereas delayed enamel formation in the later case was most probably an indirect consequence of the high porosity of the underlying dentin. Enamelin expression was unchanged in BGN KO, and reduced in DCN KO. Dentin sialoprotein (DSP), a member of the family of phosphorylated extracellular matrix proteins that play a role in dentinogenesis, was overexpressed in BGN-KO odontoblasts and in the sub-odontoblastic layer. In contrast, a decreased expression of DSP was detected in DCN KO. Dentin matrix protein-1 (DMP-1), bone sialoprotein (BSP) and osteopontin (OPN) were upregulated in BGN KO and downregulated in the DCN KO. Despite the strong effects induced by these deficiencies in newborn mice, no significant difference was detected between the three genotypes in adult mice, suggesting that the effects reported here in newborn mice are transient and subjected to self-repair.

Proteoglycans in predentin: the last 15 micrometers before mineralization.

Small leucine-rich proteoglycans (SLRPs) regulate extracellular matrix organization. In order to investigate the distribution and potential functions of decorin, biglycan (BGN), and fibromodulin (3 SLRPs, potentially related to dentinogenesis), we performed light and electron immunochemistry on teeth from rats, and on wild-type and biglycan knockout mice (BGN KO). Immunohistochemical data demonstrate that chondroitin sulfate/dermatan sulfate (CS/DS) and keratan sulfate (KS) distributions displayed reverse gradients in predentin. The decrease of CS/DS labeling from the proximal to the distal predentin contrasted with the sharp decorin increase observed in the distal predentin near the predentin/dentin transition, an effect possibly attributable to the deglycosylation action of stromelysin-1. In contrast, BGN concentration was apparently constant throughout the whole predentin. Additional immunolabelings showed, for the first time, the presence of fibromodulin in predentin. Compared with the wild-type mouse, the mean diameter of collagen fibrils in the BGN KO was smaller in the proximal predentin but larger in the central and distal predentin, the metadentin was broader, and the dentin mineralization appeared altered and heterogeneous. Altogether, our data suggest an important role for BGN in dentin formation and mineralization.