兔口腔黏膜固有层多能干细胞的分离培养

目的：探讨兔口腔黏膜固有层中是否含有间充质干细胞并对其进行分离培养。方法：利用间充质干细胞的粘附特性,对兔口腔黏膜固有层多能干细胞进行筛选分离。体外培养扩增后,以CD44、角蛋白抗体（Ck）、波形丝蛋白（Vim）抗体,免疫组化方法对细胞进行鉴定;并用MTT方法检测其增殖,流式细胞术检测其细胞周期。结果：所筛选培养的细胞可在体外呈克隆性生长,细胞表面表达CIN4分子,而不表达Ck、Vim;细胞增殖活力旺盛;流式细胞检测结果显示95．1％的细胞处于G0／G1期,与未经筛选的对照组有明显差异。结论：本实验证实在兔口腔黏膜固有层中含有成体干细胞,这类细胞可在体外成功分离并进行扩增培养。口腔黏膜固有层可能是间充质干细胞的又一重要来源,为研究间充质干细胞和口腔黏膜的生物学特性提供基础。     

应用组织工程口腔黏膜固有层修复颊黏膜缺损的实验研究

目的：评价组织工程口腔黏膜固有层修复颊黏膜缺损的效果。方法：以壳多糖-胶原凝胶为网架,与体外培养的Wistar大鼠口腔黏膜成纤维细胞构建壳多糖-胶原凝胶口腔黏膜固有层（FPCCL）,用5-BrdU标记其中的成纤维细胞后．移植修复同种异体大鼠口腔颊黏膜圆形缺损（用直径8mm的圆形刀制成）;21只Wistar大鼠随机分为FPCCL组（12只）及对照组（9只）。术后行大体观察、创面直径测量、组织学及免疫组织化学观察;所有数据用SPSSll．5统计软件包进行t检验。结果：术后大鼠创面无感染,术后7d时,2组创面均被浅黄色膜覆盖,术后14、21d时,2组创面完全被新生黏膜覆盖。术后7d时,对照组创面比FPCCL组创面显著为小（P〈0．05）。组织学观察：术后7d,2组创面未完全上皮化。术后14、21d时,2组创面完全上皮化,有钉突;上皮复层,表面有角化物;新生固有层中细胞数量较多。含毛细血管。免疫组织化学染色,FPCCL组术后7、14、21d时阳性成纤维细胞出现在肉芽组织的细胞密集处和新生固有层中．与新生组织共同参与了颊黏膜缺损的修复重建。未出现免疫排斥现象。结论：FPCCL在修复重建颊黏膜缺损、限制创口收缩方面明显优于对照组。FPCCL作为颊黏膜缺损区永久性固有层替代物是可行和有效的。     

Surface and lamina propria lipids of bovine gingiva.

In terms of both quality and quantity, the surface lipids are noticeably different from the lamina propria lipids. The surface lipids are mainly structural in nature (cholesterol, cholesterol esters, and phospholipids), whereas the lamina propria lipids are mostly of storage types (triglycerides). The surface lipids are also more unsaturated, whereas the lamina propria lipids are more saturated. Even though gingiva is histologically similar to skin, bovine gingival surface lipids are different from the bovine skin surface lipids. Further studies are needed to investigate the importance of surface lipids in regulating the various physiologic functions of gingiva.     

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目的    探讨以壳多糖-胶原凝胶为支架材料,利用口腔黏膜成纤维细胞（oral mucous fibroblast,OMF）在体外构建口腔黏膜人工固有层的可行性。方法    将2 × DMEM培养液、胎牛血清、胶原溶液、壳多糖等按一定比例配置成凝胶溶液,大鼠OMF与上述凝胶溶液迅速混合制成口腔黏膜人工固有层,动态观察细胞生长状况和凝胶收缩情况。结果    成功建立大鼠OMF种子细胞库,原代细胞与传代细胞在形态和生长速度差异无统计学意义。壳多糖-胶原-OMF复合物（FPCCL）体外培养10 d,OMF在支架材料中生长良好,细胞呈长梭形,排列无一定方向。随时间推移,OMF逐渐增多,凝胶颜色变浅,厚度变薄,3 d后发生收缩,7 d后则凝胶人工固有层稳定,无明显收缩。结论    OMF可在壳多糖-胶原凝胶形成的三维空间结构生长并分泌基质,形成类似黏膜固有层的致密结缔组织。壳多糖-胶原凝胶是构建组织工程化口腔黏膜固有层的合适材料。     

Papillarity of the palatal mucosa

A sample of 575 palatal casts was studied and found to possess varying degrees of papillary convolutions between and around the palatal rugae. No palatal appliances were worn and no irritative influence was present. A classification of 1-4 was established and the peak incidence was Class II at 48.4% (Class I, being an absence of papillarity, was 7.3%). It is postulated that the presence of a denture may well cause an inflammatory papillary hyperplasia to arise not by a progression through the various stages of denture stomatitis but directly, in an individual with a papillary palate.     

Neurofibroma of the palatal mucosa. A case report

Neurofibromas have not been reported in the periodontal literature. In this case report, a 27-year-old female presented with a complaint of a lump in the maxillary left palatal tissue; periodontal evaluation revealed a mass 15 x 8 x 4 mm on the palatal mucosa. After removal, the region healed without recurrence. The patient was referred to her physician for a physical, and no evidence of neurofibromatosis was found elsewhere, suggesting that this case represented an example of an isolated oral neurofibroma lesion.     

Elastolysis induces collagenolysis in a gingival lamina propria model

Elastin peptides were previously reported to increase MMP expression in several cell types. We found binding of these peptides to their receptors led to enhanced MMP-3 and MMP-1 expression, but not activation, in human gingival fibroblasts cultured on plastic dishes. We hypothesized that these peptides, in a more physiological environment, might additionally trigger an MMP-3/MMP-1 activation cascade, leading to matrix lysis, as occurs in periodontitis. To test this hypothesis, we used contracted and attached lattices as gingival lamina propria equivalents. In such 3D models, supplementation of elastin peptides and plasminogen triggered an MMP-3/MMP-1 activation cascade and significant down-regulation of TIMPs production, further leading to intense collagen degradation. We propose that elastolysis, as occurs in periodontitis, potentiates collagenolysis, thus promoting disease progression.     

Collagen scaffolds implanted in the palatal mucosa

Scar formation after repair of the cleft palate leads to growth impairment of the upper jaw and midface. The implantation of a suitable scaffold during surgery may reduce this adverse effect. However, little is known about tissue reactions to scaffolds implanted in the oral cavity. Our goal was to analyze the tissue reactions to cross-linked type I collagen scaffolds after submucoperiosteal implantation in the palate of rats. Collagen type I scaffolds were implanted in the palate of 25 male Wistar rats. Groups of 5 rats were killed consecutively after 1, 2, 4, 8, and 16 weeks and were processed for histologic and immunohistochemical analyses. After 1 and 2 weeks, 3 rats from the sham group were also killed. On hematoxylin and eosin-stained sections, the cell density and the number of giant cells were determined. Blood vessels, inflammation, and the presence of myofibroblasts were detected by immunohistochemistry. An influx of inflammatory cells started after 1 week but had completely subsided after 8 weeks. Myofibroblasts were observed within the scaffolds only in the first 2 weeks. Angiogenesis already started after 1 week and showed a peak after 4 weeks, slowly declining afterward. The scaffolds were gradually integrated within the host tissue and only elicited a mild and transient inflammatory response. The scaffolds were biocompatible and seemed to be promising for future applications in cleft palate surgery.     

Thickness of palatal masticatory mucosa associated with age.

BACKGROUND: The palatal masticatory mucosa is widely used as a donor material in periodontal plastic surgery. However, there are relatively few studies investigating the volume or thickness of the palatal mucosa. The purpose of this study was to determine the thickness of palatal masticatory mucosa in Asian subjects aged 14 to 59 years by a direct clinical technique. The associations of age and gender with the thickness of palatal mucosa were also examined. METHODS: Sixty-two systemically and periodontally healthy Asians (31 males; 31 females; age range 14 to 59 years) participated in this study. The younger age group (age 14 to 21 years) consisted of 32 subjects with a mean age of 16.8 years, whereas the older age group (age 30 to 59 years) consisted of 30 subjects with a mean age of 38.7 years. A bone-sounding method using a periodontal probe with minimal anesthesia and a prepared clear acrylic stent were utilized to assess the thickness of palatal mucosa at 15 measurement sites defined according to the gingival margin and mid-palatal line. Multiple linear regression analysis was performed to examine the associations of age and gender with the mean mucosal thickness at the subject level. The Wilcoxon test was used to determine the difference in mucosal thickness between the 2 age groups, and between gender at each measurement point. RESULTS: The mean thickness of palatal masticatory mucosa ranged from 2.0 to 3.7 mm. The younger age group had significantly thinner mucosa (mean 2.8 +/- 0.3 mm) than the older age group (mean 3.1 +/- 0.3 mm). Females had thinner mucosa than males in the same age group, but the difference was not statistically significant. Overall, the thickness of palatal mucosa increased from the canine to second molar areas and in the sites furthest from the gingival margin towards the mid-palate (with the exception of the first molar area, where significantly decreased thickness was observed). CONCLUSIONS: Within the limits of the present study, the canine and premolar areas appear to be the most appropriate donor site for grafting procedures in both young and adult individuals. The subepithelial connective tissue graft procedure can be considered as a treatment modality in young patients, since a sufficient volume of donor tissue can be obtained from the hard palate area. Other factors that may influence the thickness of palatal mucosa such as racial and genetic factors and body weight need to be further investigated.     

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.     

The predominant microflora of the palatal mucosa in an elderly island population.

The prevalence and microbiology of macrophotographically documented denture stomatitis were studied in denture wearers participating in an interdisciplinary health-monitoring project (Koster Health Project) on the Koster islands, Sweden. Upper dentures were used by 26.6% of the adult population, and 59.2% of the denture wearers had stomatitis. Denture stomatitis type I was identified as sialadenitis. The more severe forms of denture stomatitis (types II and III) demonstrated increased recovery of microorganisms in the palatal mucosa in addition to sialadenitis. Only one proband showed increased growth of fungi. Hemophilus spp. and Bacteroides spp. were the predominating microorganisms in stomatitis types II and III. Shifts in the normal oral flora are suggested to be an important factor for the development of denture stomatitis. It is concluded that bacterial colonization on the palatal mucosa may play an important role in denture stomatitis in this relatively healthy population.