干扰素-γ对腭部瘢痕成纤维细胞的影响

目的:探讨γ干扰素对腭部瘢痕成纤维细胞的生物学作用。方法:以腭瘢痕成纤维细胞为研究对象,采用三维培养法,了解基因重组γ干扰素(IFN-γ)对瘢痕组织中成纤维细胞的生长增殖、组织收缩等生物学活动的影响。结果:IFN-γ可以抑制腭部瘢痕成纤维细胞的生长增殖及三维培养的胶原纤维凝胶的收缩。结论:IFN-γ是创伤愈合与瘢痕形成过程中的一种负性调节因子,对减少瘢痕的形成及收缩具有一定的作用。     

Preservation of rat palatal scar tissue myofibroblasts in organ culture

In order to modulate palatal scar tissue, especially its myofibroblastic component, there is a pressing need for an in vitro model of this tissue. In the present, study we established an organ culture model of the rat palatal scar tissue. After excision of palatal mucoperiosteum, explants from the developing immature scar tissue and from the normal palatal mucosa were used to observe myofibroblasts in vivo and their maintenance in organ culture. Explants were cultured at the gas-liquid interface in serum-free Waymouth's MB 752/1 medium and in a humid atmosphere containing 55% O2/5% CO2 in air at 37 degrees C for 3 days. Viability of the cultured explants was evaluated with morphological and histological criteria and BrdU incorporation. After organ culture, the scar tissue showed good preservation of the in vivo histology. The myofibroblasts and smooth muscle cells of the cultured scar tissues showed continuous expression of alpha-smooth muscle actin (alpha-SMA), mimicking the in vivo situation. In the normal tissues, only smooth muscle cells of the blood vessels expressed alpha-SMA. These results demonstrate that the established model provides a useful in vitro experimental tool for investigating the palatal scar tissue in general and its myofibroblasts in particular.     

激光对瘢痕成纤维细胞胶原合成及前胶原基因表达的影响

目的：探讨激光对体外培养瘢痕成纤维细胞胶原合成的选择性抑制作用。方法：以不同能量密度（５００Ｊ／ｍ＾２、１０００Ｊ／ｍ＾２、１５００Ｊ／ｃｍ＾２和２０００Ｊ／ｃｍ＾２）Ｎｄ：ＹＡＧ激光照射体外培养增生性瘢痕和正常成纤维细胞,照射后２４ｈ分别用＾Ｈ－脯氨酸掺入法和斑点杂交检测成纤维细胞胶原合成和Ⅰ型前胶的基因表达。结果：培养的增生性瘢痕和正常皮肤成纤维细胞的胶原合成和Ⅰ型前胶原ｍＲＮＡ相对量在５００     

Effects of restorative materials on the palatal mucosa of the rat

The effects of self-curing acrylic resin, silver, copper, and silver amalgam were tested on the palatal mucosa of 35 rats. No significant changes were observed in the tissue when copper, silver, and acrylic resin were used. When silver amalgam of varying silver to mercury ratios was used, the tissue in contact with the material underwent extensive epithelial proliferation and hyperkeratinization. Since the pure silver induced no significant changes in the epithelium, it must be concluded that the tissue changes resulted from the increased proportion of mercury in the amalgam.     

Kr：F准分子激光对大鼠牙髓的影响

目的 研究Kr:F准分子激光对大鼠切牙牙髓的影响。方法 用功率为5W的Kr:F准分子激光照射大鼠切牙1min,百姓凰即刻、第2天、第7天分别处死5只大鼠,作病理切片观察其牙髓变化,并与Nd:YAG激光作比较,结果 Kr：F准分子激光照射后仅出现0-1级的牙髓组织变化。而Nd:YAG激光照射后出现3级变化。结论 Kr:F准分子激光照射牙体硬组织所引起的牙髓反应较小。     

Effects of interferons on proliferation and collagen synthesis of rat palatal wound fibroblasts.

The purpose was to select drugs that specifically reduce collagen synthesis by palatal granulation fibroblasts without affecting their proliferation. Granulation fibroblasts were obtained from 8-day-old palatal mucoperiosteal wounds and normal fibroblasts from palatal tissue of unwounded rats. Cultured cells were treated with interferon-alpha2b, interferon-beta and interferon-gamma (0, 100, 1000, and 10000 U/ml). Cell proliferation was measured by [3H]thymidine incorporation. Collagen synthesis and non-collagenous protein synthesis were determined from the incorporation of [3H]proline. None of the interferons significantly inhibited the proliferation of either type of fibroblasts. Interferon-alpha2b had no effect on the variables studied at the dosages used. Interferon-beta reduced collagen synthesis of granulation fibroblasts without affecting their non-collagenous protein synthesis or protein synthesis by normal fibroblasts. Interferon-gamma reduced collagen synthesis of both types of fibroblast and the non-collagenous protein synthesis of granulation fibroblasts. These data show that interferon-beta specifically reduces collagen synthesis by oral granulation fibroblasts without affecting normal palatal fibroblasts.     

口腔粘膜肥大细胞介质对成纤维细胞超微结构的影响

目的：研究口腔粘膜下纤维性变（ＯＳＦ）组织中胶原纤维增生的原因。方法：采用分离纯化人胚口腔粘膜肥大细胞的介质溶液（ＯＭＭＣＣ）与体外培养的人胚口腔粘膜成纤维细胞（ＯＭＦｂ）的共同培养,对ＯＭＦｂ进行形态计量分析。结果：ＯＭＦｂ内粗面内质网（ＲＥＲ）和线粒体（Ｍｉ）体密度、面密质和Ｍｉ的数密度增大,ＲＥＲ和Ｍｉ的比表面减小。结论：ＯＭＭＣＣ可促进ＯＭＦｂ分泌胶原蛋白的功能,肥大细胞可能参与了ＯＳＦ胶     

Analysis of scar tissue distribution on rat palates: a laser Doppler flowmetric study.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of laser Doppler flowmetry (LDF) to discriminate postoperative scar tissue distribution on the palate. METHODS: Nineteen male Wistar rats at the 20th postnatal day were divided into experimental and control groups. In the experimental group, lateral palatal mucoperiosteum was excised to form scar tissue on the palate. At the 11th postnatal week, changes in the palatal blood flow were recorded with LDF in both groups by occluding exposed common carotid arteries. Perfusion values of nonoccluded (stable) and occluded states and the ratio of occluded to stable states were compared for scar tissue and normal tissue areas, and also for the normal tissue areas. After the LDF measurements, India ink-injected specimens and tissue sections were prepared for histological observations. RESULTS AND CONCLUSIONS: Scar tissue areas showed lower perfusion values both in the stable and occluded states, reflecting a lower vascular density in the scar tissue. The ratio of the occluded to stable states was higher in the scar tissue than in the normal tissue areas. In normal tissue areas, perfusion values of both the stable and occluded states appeared to vary, but the ratio did not vary among the areas. In the LDF study, the ratio of the occluded to stable states was considered to be the better parameter for discriminating scar tissue from normal tissue.     

Effects of different scaffolds on rat adipose tissue derived stroma cells

BackgroundAdipose tissue derived stroma cells (ASC's) offer for many advantages for tissue engineering strategies over mesenchymal stroma cells from other sources and ideal carrier materials have to be identified for them. The aim of this study was to demonstrate and to compare the effects of three clinically established biomaterials on proliferation and metabolic activity of rat ASC's in vitro.Materials and methodsRat adipose tissue derived stroma cells (ASC's) were isolated and differentiated into distinct lineages proved by lineage specific staining and gene expression analysis (RT-PCR). The biomaterials Bio-Gide^®, Tutodent^® Membrane and Belotero^® Soft were tested with rat ASC's for their biocompatibility using scanning electron microscopy (SEM), cell vitality staining, cytotoxicity and proliferation tests (LDH, MTT, BrdU, WST-1).ResultsThe collagen membrane Bio-Gide^® resulted in a significantly higher viability and proliferation (WST-1, BrdU) compared to Tutodent^® Membrane. No significant difference was determined in the LDH and MTT test. The hyaluronic acid gel Belotero^® Soft showed no cytotoxicity (LDH, FDA/PI) and had no negative effects on metabolic activity (WST-1, MTT) or cell proliferation (BrdU) of ASC's.ConclusionOur results indicate Bio-Gide^® and Belotero^® Soft as preferable carrier materials for ASC's. For the further establishment of ASC's-based treatment strategies, in vivo investigations on the tissue regeneration potential of these cell-biomaterial scaffolds should follow.     

Progesterone metabolism by rat oral mucosa. III. Participation of granulation tissue and fibroblasts

The metabolism of progesterone by rat granulation tissue was studied. Experimental granulation tissue was produced by implanting viscose-cellulose sponges beneath the dorsal skin of female and male rats for 21 days. The granuloma capsules and fibroblasts in the sponges were homogenized, and mitochondrial, microsomal and soluble fractions were prepared with differential centrifugation. The subcellular Preparations were incubated with 4-¹⁴C-progesterone and NADPH for 30 min at PH 7.4 and 37°C. The metabolites were identified with column and multiple thinlayer chromatography and radioautography and quantitated with liquid scintillation counting. The granulation tissue and fibroblasts showed much less activity in metabolizing progesterone than the gingival tissue of either sex. As reported earlier, gingival tissues contain Δ⁴-5α- and,Δ⁴-5β-steroid hydrogenases and 3α-, 3β-, 20α- and 20β-hydroxysteroid dehydrogenases. The granulation tissue and fibroblasts lack 3 β-hydroxysteroid dehydrogenase activity. In addition, the fibroblasts show no 20 β-hydroxysteroid dehydrogenase activity. The enhanced metabolism of progesterone during gingival inflammation is thus probably not due to the formation of granulation tissue.     

Glycolytic activity of neonatal rat palatal mucosa maintained in organ culture

The glycolytic activity of neonatal rat palatal mucosa was determined after maintenance in a chemically defined medium for periods up to 28 days. Glycolytic specific activity progressively fell over the culture period but the protein content per expiant progressively increased. When expressed per expiant, the glycolytic activity was increased after 2 days of maintenance in vitro but then slowly returned to control values by 28 days. It is suggested that these changes are the result of altered rates of cell proliferation and maturation rather than a disturbance of cellular metabolism resulting from sub-optimal culture conditions.     

Epithelial cell kinetics of rat palatal mucosa in organ culture.

The dynamic behaviour of the epithelial cells was evaluated in explants of rat palatal mucosa maintained in a chemically-defined medium in organ culture for periods up to 28 days. Epithelial mitotic activity, comparable with that in vivo, was observed after 5 h in vitro but after 24 h had increased to 4 times the initial value. This increased activity persisted for 4 days and then gradually declined until at 10 days levels comparable with that at the start of the experiment were reached. During the initial period in culture, the thickness of the nucleated cell layer of the epithelium increased slowly, reaching a maximum after 4 days, and then decreased to the initial values by 12 days. The number of nucleated cells per square millimetre of surface also showed a transient increase but such changes did not correspond with changes in thickness. The changes in average cell volume were interpreted as a change in the relative sizes of the different epithelial compartments. It is suggested that the changes are caused by the surgical wounding of the tissues during excision; consequently, rat palatal mucosa maintained in this organ culture system provides a reliable model system for the study of oral mucosa only after a minimum period of 10 days.     

3-Hydroxy-3-methylglutaryl-coenzyme A reductase activity and chemical composition of rat palatal tissue after gamma irradiation.

The effect of various amounts of head and neck irradiation on the enzyme activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (E.C. 1.1.1.34) from rat palatal tissue was measured. Enzyme activity increased with increasing radiation exposure, showing a plateau at 800–1200 rads with about five times the original activity. Above 1200 rads, the enzyme activity returned to its previous range. It is suggested that irradiation may interfere directly or indirectly with some enzyme regulatory mechanisms.The DNA, RNA, total protein and total lipid content of the irradiated (1200 rads) and sham-irradiated rat palatal tissues were determined. Of these parameters, the total lipid was the only one significantly altered, with about a two-fold increase and with its cholesterol content greatly increased.As the liver is known to have received scattered radiation, (～-5 per cent) the enzyme activity and total cholesterol were also determined in the liver of rats that received irradiation to the neck. These values when compared to those obtained from the livers of the sham-irradiated rats showed a 2.5-fold increase in the enzyme levels of 3-hydroxy-3-methylglutaryl-coenzyme A reductase while its total cholesterol doubled.     

Effects of visible light irradiation on eugenol-treated oral mucosa

The purpose of this study was to evaluate the histopathological effects of eugenol (EUG) and iso-eugenol (IsoEUG)--with or without visible light (VL) irradiation--on oral mucous membranes. Oral mucous membranes of mice were applied with three agents, EUG, IsoEUG, and aceton (as the control) in the absence or presence of VL irradiation. VL irradiation resulted in more tissue damage for EUG- or IsoEUG-treated mucosa compared to corresponding compounds without VL irradiation, and that damage under IsoEUG treatment was greater than that under EUG treatment. Necrosis, but not apoptosis, was preferentially expressed in EUG- or IsoEUG-treated mucous membranes in the presence of VL irradiation.     

Histological localization of myxoid tissue in normal human palatal mucosa and its glycosaminoglycans

Eighteen specimens of palatal mucosa were taken from 17 human subjects. Paraffin-wax sections were stained by routine methods and with various techniques to demonstrate glycosaminoglycans (GAG). In some sections, GAG were removed by selective degradative procedures before staining. Beneath all rugae, there were myxoid areas varying in size and marginal definition. Collagen fibres were few; elastic and reticulin fibres were numerous in a minority of sections. Alcianophilia at pH 2.5, preventable by streptomyces hyaluronidase digestion, suggested the presence of hyaluronic acid beneath the rugae. Alcian-blue staining at pH 1.0 and with the critical electrolyte concentration method using 0.5 M MgCl2 did not distinguish the myxoid tissue from the surrounding connective tissue and could be prevented by digestion with testicular hyaluronidase or chondroitinase ABC. Chondroitin sulphate and, or dermatan sulphate thus may be present but were not localized to the myxoid tissue. This unusual zone of loose connective tissue may act as a physical buffer resisting the local effects of high loads by allowing reversible extrusion of the water.