Several growth factors and polypeptides are not commonly yet used for regenerators of bone tissue or alveolar bone because of the insufficiency of studies on their side effects, genetic engineering for mass production and stability for clinical application. Recently, many natural medicines, which have advantage of less side effects and possibility of long-term use, have been studied for their capacity and effects of anti-bacterial, antiinflammatory and regenerative potential of periodontal tissues. Olibanum, Myrrha, Phlomis Radix, and Cimicifugae Rhizoma have been traditionally used as a drug for treatment of bone disease in oriental medicine. The objective of this study was to examine the ability of alkaline phosphatase(ALP) synthesis of rat calvarial osteoblast(MC3T3-E1) when several natural medicines were supplemented. MC3T3-E1 cells were cultured with alpha-MEM(negative control), dexamethasone(positive control), and each natural medicines for 3 and 5 days. And then ALP synthesis was measured by spectrophotometer for enzyme activity and by naphthol AS-BI staining for morphometry. All of the natural medicines induced higher activity of ALP synthesis than the negative controls. Especially Olibanum induced the higher activity than the positive controls(p<0.05). In the aspects of culturing time, except Cimicifugae Rhizoma, the natural medicines induced higher activity of ALP synthesis at 5 days than at 3 days(p<0.05). In morphometry, all of the natural medicines showed statistical significance compared to the negative control(p<0.05). Myrrha and Phlomis Radix showed larger positively stained area at 5 days than at 3 days, whereas the others did not showed the difference between at 5 and at 3 days(p<0.05). These results indicate that several natural medicines have an inducing ability of ALP synthesis in MC3T3-E1 cells.
Rats ; Animals

No abstract available.
Animals ; Rats*

No abstract available.
Animals ; Rats*

The surface characteristics of titanium have been shown to have an important role in contact ossseointegration around the implant. Anodizing at high voltage produces microporous structure and increases thickness of surface titanium dioxide layer. The aim of present study was to analyse the response of rat calvarial osteoblast cell to commercially pure titanium and Ti-6Al-4V anodized in 0.06 mol/l beta-glycerophosphate and 0.03 mol/l sodium acetate. In this study, rat calvarial osteoblasts were used to assay for cell viability and cell proliferation on the implant surface at 1, 2, 4, 7 days. 1. Surface roughness was 1.256micrometer at 200V, and 1.745micrometer at 300V. 2. The thickness of titanium oxide layer was increased 1micrometer with the increase of 50V. 3. The proliferation rate of osteoblastic cells was increased with the increase of the surface roughness and the thickness of titanium oxide layer. 4. There was no difference in cell viability and cell proliferation between commercially pure titanium and Ti- 6Al-4V anodized at the same condition. In conclusion, the titanium surface modified by anodizing was biocompatible, produced enhanced osteoblastic response. The reasons of enhanced osteoblast response might be due to reduced metal ion release by thickened and stabilized titanium dioxide layer and microporous rough structures.
Rats ; Animals

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can be used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region. For an experimental model, a calvarial defect of rat was selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set as an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and histometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogenesis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1 %, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.
Rats ; Animals

No abstract available.
Animals ; Rats*

The cholestasis are defined as blockade or secretory distrubance of bile and appearance of bile in hepatocytes, Kupffer cells and biliary passages, usually associated with dilated bile canaliculi. Intra-and extraheptic cholestasis were induced by 17-ethinyl estradiol, or chlorpromazine hydrochloride and by ligation of bile duct to investigate the mechanism of the hepatic injury, ultrastructural changes of liver and alterations of liver function. The results obtained were as follows. 1) Functional and histological changes of intra-and extrahepatic cholestasis differed in various experimental groups. The liver weight is increased in 17-ethinyl estradiol treated group and ligation of bile duct group (5.6+/-0.15, P<0.001, 5.3+/-0.19 gm/100 gm body weight, P<0.001). The common features of intra-and extrahepatic cholestasis were double membrane bounded amorphous vesicular material infiltrations in the cytoplasm of hepatocyte, partial loss of microvilli of bile canaliculi, anf focal thickening of pericanalicular ectoplasm on electron microscopy. 2) Intrahepatic cholestasis induced by 17-ethinyl estradiol show significantly increased serum level of alkaline phosphatase and total bile aicd (134.0+/-16.82 IU/L, 29.5+/-4.68 umol/l). Kupffer cell proliferation and focal cytoplasmic degradation with myelin figures are characteristic features on electron microscopy. Chlorpromazine hydrochloride induced intrahepatic cholestasis show increased serum level of AST, ALT, Cholesterol and bilirubin (156.9+/-11.32, 49.0+/-2.83 IU/L, 59.3+/-6.73 mg/dl, 1.8+/-.043 mg/dl). Inflammatory cell infiltration, chiefly lymphocytes and esoinophils are seen in periportal area. Prominent vesiculation and vacuolations of smooth endoplasmic reticulum are characteristic feature on electron microscopy. 3) Extrahepatic cholestasis induced by ligation of bile duct show increase serum level of AST, ALT, GGT, cholesterol, total bile acid, and bilirubin (290.2+/-50.24, 171.5+/-47.17, 159.3+/-24.54, 33.7+/-1.47 IU/L, 86.6+/-9.18 mg/dl, 246.6+/-27.34 umol/l, 13.9+/-0.83 mg/dl). Light microscopically, morphologic alterations are feathery degeneration of hepatocytes, proliferation of bile ducts, bile infarct and prominent intracytoplasmic lipid droplets. Electron microscopically, electron dense acidophilic body, bile casts and complete loss of microvilli are seen in dilated bile canaliculi. Also noted are hypertrophy of cannalicular ectoplasm. Finely granular materials are infiltrated in degenerative cytoplasm.
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To fine out the changes of DNA ploidy and cellular proliferation activity during carcinogenesis and evaluate correlation between flow cytometrically determined S-phase fraction and proportion of proliferation cell nuclear antigen(PCNA, PC10) immunoreactive cells, the authors studied on malignant fibrous histocytoma induced by intra-articular injection of 9, 10-dimethy1-1, 2-benzanthracene(DMBA) in the rats. Forty Wistar rats were used. The results obtained were as follows. 1) Firstly, tumors were palpated 5 weeks after the last injection of DMBA and formed in 27 rats at sacrificed. Histologically, these lesions showed storiform, indicative of malignant fibrous histiocytoma. 2) Three cases of DNA aneuploidy were observed at 4 and 5 months after the last injection of DBMA and one of them, which was DNA diploidy at main mass, was found at daughter mass. 3) Flow cytometrically determined S-phase fraction and proportion of PCNA(PC10) immunoreactive cells in malignant fibrous histiocytoma induced by DMBA were much higher than in control groups and slightly increased according to sequential changes after formation of mass. The comparison of flow cytometrically determined S-phase fraction and proportion of PCNA(PC10) immunoreactive cells showed significant correlation(r=0.6092, p<0.001). Above results strongly suggest that ploidy pattern may evolve into aneuploid type during the development of tumor and proliferation activity increases during the carcinogenesis.
Rats ; Animals

To clarity the effect of biliary obliteration on copper metabolism of rat liver and on the hepatic morphology, 0.5% cuppuric sulfate was administered intraperitoneally for 42 days following ligation of the common bile duct (CBD) of Sprague-Dawley rats. The blood copper concentration, the hepatic copper content and the accumulation patterns of copper and copper binding protein in the liver were examined and compared with those of the simple CBD ligation group and the simple copper over loaded group. CBD ligation induced marked proliferation of bile ductular structures which, after expanding the portal tracts, invaded and divided the hepatic lobules. There was, however, no excess fibosis beyond what needed to support the new ductules. The blood copper concentration and the hepatic copper content were increased by copper overload with or without CBD ligation, particularly incases with CBD ligation. Liver cell necrosis did not occur by the overloaded copper alone in rats. The hepatic copper and copper binding protein were accumulated at periportal liver cells in the group of coppe overload after CBD ligatio, whereas they began to appear at perivenular hepatocytes in the simple copper overloaded group. In conclusion, it is suggested that CBD ligation does not induce excess fibrosis or liver cirrhosis in rat as far as during our experimental period, but affect significantly on copper metabolism by intrahepatic redistribution of the copper and the copper binding proteins.
Rats ; Animals

Author performed this experiment to define the most important factor preventing the intimal thickening. An endothelium of abdominal aorta in the rat was denuded by two different wires having same caliver. The degree of injury was limited to the endothelial cells in one, and extended to the internal elastic lamina in another. The results showed that at 72 hours, in the case of superficial injury, the entire injury site was covered by new regenerating cells, but in the case of disruption of the internal elastic lamina, the migrating smooth muscle cell completely reached into the intima and resulted in intemal thickening. Similar findings persisted to 1 week later. Above results suggest the most important factor preventing the intimal thickening in endothelial injury is the depth of the injury which limited within the endothelial cells without extending into the internal elastic lamina and medial smooth muscle cells.
Rats ; Animals