New attachment following surgical treatment of human periodontal disease

Abstract The present experiment was undertaken to test the hypothesis that new connective tissue attachment may form on a previously periodontitis involved root surface provided cells originating from the periodontal ligament are enabled to repopulate the root surface during healing. A mandibular incisor with advanced periodontal disease of long standing (the distance between the cemento-enamel junction and the alveolar bone crest was 9 mm) was subjected to periodontal surgery using a technique which during healing prevented the dentogingival epithelium and the gingival connective tissue from reaching contact with the curetted root surface. Preference was hereby given to the periodontal ligament cells to repopulate the previously diseased root surface. After 3 months of healing a block biopsy containing the incisor and surrounding tissue was sampled. The histological analysis revealed that new cementum with inserting principal fibers had formed on the previously diseased root surface. This new attachment extended in coronal direction to a level 5 mm coronal to the alveolar bone crest. This finding suggests that new attachment can be achieved by cells originating from the periodontal ligament and demonstrates that the concept that the periodontitis affected root surface is a major preventive factor for new attachment is invalid.     

Effect of low intensity laser irradiation on surgically created bony defects in rats

Low intensity lasers have been used by clinicians to improve healing and reduce pain in humans. Lasing also results in new bone formation around hydroxyapatite implants and a significant increase in the total bone area. However, the exact mechanism of cell biostimulation by laser is still unclear. This study biochemically assessed the effects of low intensity laser (Gallium-Arsenide) using 4 and 22.4 mW cm(-2) power density on the bone healing process after surgically creating bony cavities in rat mandibles. Rats (n = 24) were divided into two groups each treated with specific energy, 4 or 22.4 mW cm(-2), for 3 min each day post-surgery. Surgical cavities were created on both sides of the mandible: the left served as an untreated control, the right was treated with laser. All rats were sacrificed after 1, 2 and 4 weeks of treatment. In the newly formed callus, accumulation of radiocalcium and alkaline phosphatase activity was measured to indicate osteogenic activity. One-way anova with repeated measures showed that the low intensity laser using 4 mW cm(-2) power density significantly increased radiocalcium accumulation from 2 weeks post-surgery, whereas 22.4 mW cm(-2) had no effect. No changes were noted in the activity of alkaline phosphatase with the laser treatment. These results suggest that laser therapy of low power density is effective on the bone healing process in artificially created osseous cavities by affecting calcium transport during new bone formation.     

Retardation of epithelial migration in new attachment attempts in intrabony defects in monkeys

Abstract New attachment procedures were performed in 80 three-wall intrabony defects produced adjacent to incisors and canines in monkeys. Following a reverse bevel incision, rnucoperiosteaS flaps were raised on the buccal and lingual aspect of 40 intrabony defects, AH soft tissue was removed from the defects and following transplantation of autogenous bone grafts, the tissue flaps were replaced and sutured. On the buccal and lingual aspect of another 40 intrabony defects a split flap procedure was performed. Granulation tissue was removed from the defects and following transplantation of autogenous bone grafts, the defects were covered with free palatal grafts. The animate were sacrificed (o yield observation periods from 0 to 42 days. After de-caicification of the specimens and embedding in paraffin, 8-μm serial sections were cut and stained. The epithelium on the full thickness flap seemed almost unaffected by the surgical procedure and had migrated between 0.2 mm and 2.0 mm along the root surface during the first week of healing. The epithelium on the transplants degenerated almost completely within the first week after surgery and epithelial migration along the root surface was not observed until after 10–12 days. These results indicate that the migration of epithelium during the postoperative phase of new attachment attempts can be retarded by covering the defects with free palatal grafts instead of full thickness flaps.     

Radiographic study of periosteal new bone formation in osteomyelitis of the mandible

A total of 1008 cases with osteomyelitis of the mandible underwent radiological examinations at the department of Oral Radiology, Osaka Dental University Hospital from 1979 to 1988. Osteomyelitis with periosteal new bone formation was observed in 114 out of the 1008 cases (11.3%). The radiographic patterns of the periosteal new bone formation were grouped into 3 types: solid, laminated and one-layer. Sixty-seven of the 114 cases (58.8%) were of the solid type, 23 cases (20.2%) were the laminated type and 24 cases (21.0%) were the one-layer type. The average age in the solid type was 30.8 years, 23.8 years in the laminated type and 38.0 years in the one-layer type. Concerning the sites of periosteal new bone formation 94 out of 114 cases (82.5%) were in the mandibular body and 20 (17.5%) in the ascending ramus of the mandible. The extent of the periosteal new bone formation was far larger among the young. This was particularly remarkable in the ascending ramus of the mandible. These findings were proved to correlate with the age, the clinical symptoms, the route of infection and the condition of eruption in the lower molars.     

Repair of periodontal tissues In vivo and in vitro

Repair of experimental cavities in dental roots and of periodontal wounds was studied in vivo and in vitro. Incisors from monkeys were extracted and experimental cavities were made in the roots. The teeth were either replanted immediately or cultured for 1-12 weeks in tissue culture medium. After 8 weeks the tissue reaction around the replanted teeth was evaluated on demineralized histological sections and undecalcified freeze-sections incubated for histochemical demonstration of certain enzymes. The cultured teeth were evaluated on decalcified histological sections. In the experimental cavities of the replanted teeth reparative cementum was found. It was frequently separated from the denuded dentin while a firm attachment was always established to the intermediate cementum and dental cementum at the periphery of the cavities. The reparative cementum was also firmly attached to some small areas on the exposed dentin surface where resorption had taken place. The activity of alkaline and acid phosphatase was lower in the connective tissue in the experimental cavities than in the surrounding PDM, suggesting an incomplete regeneration of the periodontal membrane in these areas. A loose connective tissue devoid of demonstrable collagen fibers was found in the cavities in vitro. The reparative cementum did not fill the experimental cavities in the replanted teeth. The alveolar bone extended into the experimental cavities and made the width of the PDM normal also in the experimental cavities. Epithelial and endothelial cells were numerous in the connective tissue separating the reparative cementum from the alveolar bone in the experimental cavities. It is possible that they contribute to the integrity of the PDM and prevent resorption of the dental root.     

再探五运六气起始时间

五运六气的推演必须首先建立一个始点,始点的正确与否决定了推演的成败。目前学术界主要有3种观点:大寒说、立春说和正月朔日说。因此初运和初气起始时间如何界定,成为不可回避的关键问题,亟待解决。文章从文献沿革、原理评价、现代气象数据验证3个角度,讨论为何初运和初气起于立春。立春日与正月朔日是同一天的不同说法,下言立春说。从文献沿革上讲,内经原义主张立春说,大寒说多见于经注;从原理评价上讲,立春说比大寒说更加说理通畅,透彻圆融;从现代实际气象数据验证上讲,立春说证据较多且能符合中原地区气候变化。暂论证认为,初运和初气起始时间应为立春。     

新医科背景下医学检验技术专业人才培养模式改革与创新

目的:在新医科背景下,培养适应医学检验技术快速发展的医学检验技术人才。方法:更新教育教学理念,改革人才培养模式,深化产教融合,重构医学检验技术专业课程体系,打造信息化实践教学平台,提高双师队伍比例,突出办学特色。结果:通过以上几个方面的改革,使专业教育教学改革有明显成效,人才培养质量明显提高,服务地方健康产业的能力明显增强,专业特色进一步彰显,在全省乃至全国同类民办院校中起到示范和引领作用。结论:医学检验技术的信息化、标准化的发展,必须改变传统的教学模式才能适应行业的发展和社会的需求。     

脂质代谢与肺癌相关性及其潜在治疗靶点

正脂质代谢调节机制在肿瘤发生发展中的重要性已得到广泛关注。通过增加多种脂肪生成酶的表达,肿瘤细胞可以诱导新生脂肪形成,甚至有研究者认为新生脂肪组织生成的增加可作为多种侵袭性肿瘤的新型标志~([1])。肺部肿瘤常存在血管异构,在限制肿瘤细胞营养供应的同时,造成细胞缺氧微环境,最终诱导肿瘤细胞发生包括脂代谢在内的多方面代谢变化~([2])。     

医患合作新模式在学龄期儿童哮喘管理中的价值

目的分析医患共同商讨哮喘儿童用药方案及管理计划新模式在学龄期儿童哮喘规范化管理中的价值。方法选取2019年4月—2019年10月在同济大学附属第十人民医院儿科就诊的100例哮喘患儿为研究对象,医务人员通过门诊与电话随访、微信互动等相结合的方法与患儿及家长建立良好的伙伴关系,共同商讨决策哮喘患儿的用药方案和管理计划,对哮喘儿童实施规范化管理。比较规范化管理之前与规范化管理6个月后哮喘儿童的哮喘急性发作次数、急诊就医次数、住院次数、用药依从性和哮喘控制率之间的差异,并进行年龄分层分析;比较入组时、规范化管理3个月后及规范化管理6个月后肺功能各指标的变化。结果规范化管理6个月后与规范化管理之前比较有着更少的哮喘急性发作、急诊就医和住院次数,有着更高的用药依从性和哮喘控制率。对规范化管理是否影响儿童哮喘控制情况进行年龄分层分析,不同年龄组中规范化管理对儿童哮喘急性发作次数、急诊就医次数、用药依从性和哮喘控制水平的的影响是一致的(P＞0.05),哮喘急性发作次数、急诊就医次数与规范化管理呈负相关关系,用药依从性和哮喘控制水平与规范化管理呈正相关关系。规范化管理3个月后和6个月后的肺功能各指标较入组时明显改善,且差异具有统计学意义（P<0.05）,但规范化管理6个月后与规范化管理3个月后的肺功能各指标比较,仅25%用力呼气流速、50%用力呼气流速指标差异具有统计学意义（P<0.05）。结论医务人员与患儿及家长通过多渠道合作共同商讨决策哮喘儿童用药方案及管理计划的新模式能有效提高儿童哮喘控制水平,降低未来哮喘发作风险,值得在临床进一步推广。     

针对性护理干预对根治性膀胱全切回肠原位膀胱术后新膀胱功能的影响

目的 分析针对性护理干预对根治性膀胱全切回肠原位膀胱术后新膀胱功能的影响.方法 选择2018年7月至2020年7月收治的80例行根治性膀胱全切回肠原位膀胱术治疗患者为研究对象,按照护理方法将其分为对照组与观察组,各40例.对照组给予常规护理干预,观察组在此基础上给予针对性护理干预.比较两组的护理效果.结果 观察组的排尿困难、尿失禁、泌尿系统感染发生率低于对照组,膀胱功能分级优于对照组(P<0.05).术后3个月,观察组的膀胱容量、膀胱逼尿肌压力大于对照组,残余尿量少于对照组,SF-36各维度评分高于对照组(P<0.05).观察组的护理满意度显著高于对照组(P<0.05).结论 针对性护理干预应用于根治性膀胱全切回肠原位膀胱术后患者中,有助于促进新膀胱排尿功能恢复,改善患者预后.