• The korean journal of orthodontics
• /
• v.28 no.3 s.68
• /
• pp.399-407
• /
• 1998

In order to resolve enamel demineralization around orthodontic bracket, fluoride-releasing materials, glass ionomer cements and fluoride-containing resin, were introduced in orthodontic department. There were many studies about their fluoride release, but their results were controversial. The purpose of this study was to clarify the pattern and amounts of fluoride release from glass ionomer cements and a fluoride-containing resin during 70 days in vitro. Disc shaped specimens were prepared and immersed in polyethylene tube containing 2ml distilled deionized water. The daily amounts of the fluoride released from each specimens were measured after experiment 1 day, 3 days, 7 days, 14 days, 42 days and 70 days. They were measured by fluoride-specific electrode combined pH/Ion meter. The following results were as follow, 1. Fluorides released from fluoride-containing resin during 1 day were significantly less than those from glass ionomer cements. 2. On experiment 70 days, mean daily amounts of fluoride released from Miracle-$Mix^{\circledR}$were $3.4{\mu}g/cm^2$, those from Fuji GC $II^{\circledR}$ were $2.7{\mu}g/cm^2$, those from $Orthobond^{\circledR}$ were $2.3{\mu}g/cm^2$, those from Fuji GC $LC^{\circledR}$were $1.4{\mu}g/cm^2$ and those from fluoride-containing resin, $Heliomolar^{\circledR}$, were $0.1{\mu}g/cm^2$. 3. There were no significant differences in daily amounts of fluoride released from between self-curing glass ionomer cements and light-curing glass ionomer cements. Amounts of released fluoride varied among commercially available products. 4. In all experimental materials, amounts of released fluoride decreased rapidly until experimental 3 days and then decreased slowly until 14 days and more slowly until 70 days.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.6
• /
• pp.775-785
• /
• 1999

Background : The herbicide paraquat can cause severe lung injury and fibrosis in experimental animals. In this study we have investigated the changes in lung endothelin-1(Et-1) levels and immunohistochemical localization in relation to treatment with cyclophosphamide and methylprednisolone in paraquat induced pulmonary fibrosis in guinea pigs. Material and methods : 29 male Hartley guinea pigs were divided into 4 groups. Group I was normal control. Paraquat was instilled into the lung of guinea pig of group II, III and IV unilaterally. Group II was treated with cyclophosphamide and methylprednisolone. Group III was treated with methlprednisolone. Group IV was not treated. The degree of fibrosis was evaluated by H-E stains and Masson's trichrome stains and cell activity was assessed by Et-1 immunohistochemical stains. Statistical evaluation was performed using the Kruskawallis oneway analysis. Results : Paraquat induced an increase in numbers of fibroblasts and total amount of lung collagen in Group IV compared to the normal controls. There was no significant difference in total numbers of fibroblasts between any of paraquat instilled groups, but there was significant increase in total amount of collagen in Group IV compared to group II and III (p<0.05). The treatment of cyclophosphamide and methyprednisolone suppressed the growths of both fibroblasts and collagen, but this suppression was stastically significant only in the case of collagen Et-1 immunoreactivities of bronchial epithelium, type II pneumocytes, endothelial cells and fibroblast in group II and III were decreased compared to those in group IV. Conclusion : These results demonstrate that Et-1 is an important contributing factor in the pathogenesis of pulmonary fibrosis. Et-1 is synthesized and released by bronchial epithelium, Type II pneumocyte, endothelial cells, alveolar macrophages and fibroblasts. Especially they are associated with alveolar macrophage and fibroblasts. We conclude that combined therapy of cyclophosphamide and methylprednisolone are more effective in the control of Et-1 expression and collagen deposition.

• Journal of radiological science and technology
• /
• v.26 no.4
• /
• pp.21-26
• /
• 2003

To evaluate the newly designed gastroduodenal coil catheter:in-vitro test. The coil catheter that we made in our laboratory was 150 cm. The coil that is made of stainless steel wire was composed 1.3 mm inner diameter and this coil spring was covered with heat-shrinkable polyethylene tube. To measure the length under fluorocopy, 8 radiopaque marks were attached at 5 cm, 10 cm, 11 cm, 12 cm, 13 cm, 14 cm, 15 cm, 20 cm apart from distal end of the catheter and 6, 2, 1 pores were made at 7 cm, 13 cm, 19 cm apart from the distal end. Radio-opacity and the amount of injected contrast was investigated in formerly used 5 Fr. vessel catheter, which is possible in measuring length, and newly designed coil catheter. Film density was tested for radio-opacity with autodensitometer. For measuring the volume of injected salin, the catheter was located in the acryl box(26 cm, 3 cm, 16 cm) that divided into 4 chambers. After injection 50 cc of contrast with autoinjector, the contrast's quantity in each chamber was measured with and without over the guide wire. Radio-opacity was 0.51 in 5 Fr. vessel catheter, 0.31 in newly made catheter. The amount of injected contrast was measured. In case of 5 Fr. vessel catheter, the amount was 99.5% from the distal part, there was no difference between with and without the guide wire. Otherwise, using a coil catheter, the pacentage the ejected saline was 1.17%, 18.8%, 41.8%, 38.2% from the distal part with the guide wire, 19.5%, 32.6%, 27.7%, 20.3% without the guide wire. Compare with formerly established catheter, this new coil catheter is easy to measure the length thanks to easy confirming under fluoroscopy and excellent in injecting contrast. Therefore, newly designed gastrointestinal catheter seems to be useful in gastrointestinal intervention procedure.