Expression of Keratinocyte Growth Factor in Periapical Lesions

The epithelial proliferation associated with inflammatory periapical lesions and with periapical cyst formation represents an interesting but poorly understood pathological change. Keratinocyte growth factor (KGF) is a recently identified growth factor that is produced by stromal fibroblasts and acts specifically to stimulate epithelial growth and differentiation. To investigate its possible role in the activation of the normally quiescent rests of Malassez, we examined the expression of KGF by in situ hybridization of sections of normal periodontal ligament (PDL) and of 12 periapical granulomas or cysts. Normal PDL and periapical granulomas with scant inflammatory infiltration showed few cells expressing message for KGF. However, KGFexpressing cells were found in the connective tissue stroma close to dense foci of inflammatory cells and to proliferating epithelial elements and cystic epithelial linings. Examination of tissues by the reverse-transcription polymerase chain reaction (RT-PCR) showed KGF expression in 4 specimens of periapical lesions but low or undetectable levels in normal PDL. These observations suggest that the induction of KGF expression in the stromal cells of periapical lesions may play an important role in stimulating the epithelial proliferation associated with cyst formation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66683/2/10.1177_00220345960750090701.pd

Avaliação da concentração de flúor em águas minerais comercializadas no Brasil Evaluation of fluoride content of bottled drinking waters in Brazil

A utilização de flúor sistêmico deve ser controlada em termos de risco/benefício, pois enquanto a subdosagem não trouxer benefício anticárie, a sobredosagem estará associada com fluorose dental. Assim, uma das preocupações é o consumo de águas minerais, o qual tem aumentado nos últimos anos. Deste modo, foi realizado estudo com o objetivo de analisar a concentração de flúor em águas minerais comercializadas no Brasil. Foram analisadas 104 marcas comerciais, de diferentes regiões do País. Utilizou-se eletrodo específico Orion 96-09 e analisador de íons Orion EA 940, previamente calibrados com soluções padrões de flúor. Foram observadas concentrações de flúor variando de 0,0 a 4,4 ppm. Constataram-se: 1) Concentrações significativas de flúor não relatadas pelo produtor; 2) Concentrações de flúor sem significado preventivo anti-cárie, embora o produtor destaque na embalagem "Água Mineral Fluoretada"; 3) Concentrações de flúor capazes de provocar fluorose dental severa, embora o produtor não faça nenhuma referência que o mesmo existe. Conclui-se ser necessário um Sistema de Vigilância Sanitária para o controle de flúor nas águas minerais oferecidas à população brasileira, quer seja em termos de benefício como de risco.<br>The utilization of a systemic fluoride method must be controlled in terms of risks and benefits. The reason for this is that while a small dose will not be effective in preventing dental caries, a larger dose may cause dental fluorosis. Therefore the knowledge of the fluoride concentration found in the bottled mineral waters sold throughout the Brazilian market the consumption of which has increased lately, is of great concern. The objective of the study was the analysis of the concentration of fluoride found in the bottled mineral waters. A hundred and four brands coming from different regions of Brazil were analysed using an Orion 96-09 ion specific electrode and an Orion EA 940 ionanalyser, previously calibrated with standard fluoride solutions. Different concentrations of fluoride ranging from 0.0 to 4.4 were found. It was discovered that specific bottled waters contained: 1) Significant concentrations of fluoride not reported by the producer; 2) Fluoride concentrations of no preventive effect, although the producer had advertised the water as a Fluoridated Mineral Water; 3) Fluoride concentrations high enough to cause dental fluorosis, although the producer did not alert the consumer to this fact. It is to be concluded, therefore, that a sanitary regulatory system for the control of the level of fluoride in the bottled mineral waters marketed is necessary. Such reputation should be formulated in terms of benefits as well as in terms of risks