[Re-understanding the role of enamel matrix proteins in periodontal regeneration].

Enamel matrix proteins (EMP) are deposited on the surface of developing roots before dentin formation and may play a role in osteogenesis. Amelogenins (Am) are the main and active component in EMPs. Studies had showed great clinical values of EMPs in periodontal regenerative treatment and other fields. By affecting the expression of growth factors and inflammatory factors, EMPs could act on various periodontal regeneration-related cells to promote angiogenesis, anti-inflammation, bacteriostasis and tissue healing, achieving the clinical effect of periodontal tissue regeneration (newly generated cements and alveolar bones as well as functionally penetrated periodontal ligament). EMPs alone or combined with bone graft material and barrier can be used for regenerative surgical treatment in intrabony defects and degree Ⅱ furcation-involved at maxillary buccal or mandibular teeth. EMPs can also be adjunctively used to treat recession type 1 or 2 gingival recessions, forming periodontal regeneration on the exposed root surface. Through a comprehensive understanding of the principle and current clinical application of EMPs on periodontal regeneration, we can look forward to their future development. The development of recombinant human amelogenin to replace animal-derived EMPs through bioengineering technologies, the study of the clinical application of EMPs combined with other collagen biomaterials, and the specific application of EMPs in severe soft and hard periodontal tissue defects and peri-implant lesions are all important development directions of future EMPs-related researches.

[Analyzing the relevant factors affecting the clinical outcome of periodontal regeneration surgery].

Periodontitis can lead to periodontal tissue defect, tooth mobility and loss, which seriously affects the quality of life. Periodontal regeneration surgery is an important treatment method for repairing periodontal defects, and it is also the hotspot of current periodontal clinical and basic research. A comprehensive understanding of the factors affecting the efficacy of periodontal regenerative surgery can improve clinicians' periodontal treatment concepts, increases the predictability of treatment results, and enhances the level of clinical diagnosis and periodontal treatment. In order to instruct the clinicians, this article will explain the basic principles of periodontal regeneration and the key points of periodontal wound healing, and analyze the elements of periodontal regeneration surgery, which including the patient-related factors, local factors, surgical factors and regenerative material selection.

[Association between periodontitis and mild cognitive impairment: a clinical pilot study].

Objective: To evaluate the association between periodontitis and mild cognitive impairment (MCI), and explore the potential local oral risk factors for MCI. Methods: The study included 70 middle-aged and elderly subjects (44 females and 26 males) with periodontal disease who were first diagnosed by the Department of Periodontology or referred by the Department of Geriatrics in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from January 2021 to January 2022. In this study, the control group consisted of periodontal disease patients without cognitive impairment, and the case group (MCI group) consisted of those diagnosed with MCI referred by the geriatrics specialists. Full-mouth periodontal examinations of all subjects were performed and periodontal indicators were recorded by periodontists, while digital panoramic radiographs were taken. The severity of periodontitis was defined according to the 1999 classification, and the staging and grading of periodontitis were defined according to the 2018 American Academy of Periodontology and European Federation of Periodontology classification. The mini-mental state examination scale was chosen by geriatricians to evaluate the cognitive function of the included subjects. The cubital venous blood was drawn to detect the expression levels of inflammatory factors such as hypersensitive C-reactive protein (hs-CRP), interleukin (IL)-1ß, IL-6 and tumor necrosis factor-α(TNF-α) in serum. Independent-samples t test and chi-square test were used to analyze the differences in population factors, periodontal-related indexes and serum inflammatory factors between the two groups (α=0.05). Odds ratios (OR) for MCI according to the severity of periodontitis and main periodontal clinical indexes were calculated by binary Logistic analysis. Results: Thirty-nine subjects were included in the control group and thirty-one in the MCI group. The age of the study population was (58.3±6.2) years (range: 45-70 years). The comparison between two groups showed that the control group was with higher educational background (χ²=9.45, P=0.024) and 2.6 years younger than the MCI group [(57.1±6.0) years vs. (59.7±6.3) years, t=-1.24, P=0.082]. The number and proportion of moderate to severe periodontitis in control group were significantly lower compared to those in MCI group (17 cases with 43.6% vs. 23 cases with 74.2%, χ²=6.61, P=0.010), and the OR of moderate to severe periodontitis adjusted by age and educational background was 3.00 (95%CI: 1.01-8.86, P=0.048). Compared with the grading (χ²=5.56, P=0.062) of periodontitis, staging had a greater impact on MCI (χ²=7.69, P=0.041), moreover the proportion of MCI in stage Ⅰ grade A periodontitis was significantly lower than any other type of periodontitis (χ²=13.86, P=0.036). In addition, less presence of deep periodontal pockets [probing depth (PD)≥6 mm] (17.9% vs. 41.9%, χ²=4.87, P=0.027), fewer number of PD≥4 mm (6.48±6.70 vs. 11.03±8.91, t=-2.44, P=0.017), lower plaque index (1.42±0.56 vs. 1.68±0.57, t=-1.91, P=0.059) and gingival index (1.68±0.29 vs. 1.96±0.30, t=-3.93, P<0.001) were in the control group than in the MCI group. However, there were no significant differences between the two groups in the levels of serum inflammatory factors, such as hs-CRP, IL-1ß, IL-6 and TNF-α (P>0.05). Conclusions: It appears a strong correlation between moderate to severe periodontitis and the incidence of MCI in middle-aged and elderly people. Moreover, deep and increased number of periodontal pockets, poor oral hygiene, and severe gingival inflammation can be potentially associated risk factors for MCI.

Chondrosarcoma in a paediatric population: a study of 247 cases.

PURPOSE: The aims of present study are to clarify the follow questions: 1) what constitutes paediatric chondrosarcoma?; 2) what are the effects of the demographic and tumour characteristics on survival in patients with paediatric chondrosarcoma?; 3) which prognostic factors of paediatric chondrosarcoma differ from those of the adult population, which have been reported previously? METHODS: Paediatric patients who were diagnosed with chondrosarcoma were searched for using the case listing session protocol of the National Cancer Institute's Surveillance, Epidemiology, and End Results 18 databases (1973 to 2014). The extracted demographic information includes: age, race, gender, year of diagnosis, tumour sites, tumour histological subtype, grade, stage and treatment. RESULTS: A total of 247 paediatric chondrosarcoma patients were extracted and included in our present study. We find that the paediatric patients have significantly better survival rates than the adult patients. The year of diagnosis, tumour sites, tumour histological subtype, grade, stage and surgery received are independent prognostic factors for the survival rate of paediatric chondrosarcoma patients, but race, gender and age are not. CONCLUSION: The paediatric chondrosarcoma patients have better survival rates than the adults. Paediatric patients with a diagnosis at an early age, tumour site at the vertebral column and pelvis/sacrococcyx, myxoid variants, high grade, distant stage and who did not have surgery have a poorer prognosis than patients with a diagnosis at a later age, tumour site at limbs, head and base, chondrosarcoma not otherwise specified, lower grade, localized stage and who received surgery. LEVEL OF EVIDENCE: II -Prognostic Study.

[A study on Wu Jinshou].

Wu Jinshou()[(1785-1795)-(1844-1851)]once wanted to take the imperial examination, but in late Qing Dynasty, under the depressed situation of economics and politics, he was trapped in countryside as many lower intellectuals, and chose medicine as another way to earn a living. In fact, he was both a doctor and a literatus. He kept friends with scholars, such as Zhang Tingji, Yao Wentian, Lu Changchun, Wei Guangfu, and scholar-physicians like Chen XIshu, Lu zeng and also Xu Jin's family, famous doctors at that time. He changed status Flexibly. To some extent, he represented the basic appearance of the traditional Chinese practitioner. In Daoguang 11 years(1831), Wu Jinshou published Medincal Cases Records of Three physicians(《》), Yi Xiao Mi Chuan(《》), Wen Re Zhui Yan(《》). This naturally have business purpose and was market-oriented. He had influenced on the spread of Wuzhong(the name of Suzhou and its surrounding area in Ming and Qing Dynasty) medical books, and provided some topics to the study of the Wenbing academic history.

[A brief investigation on Gu Dehua, a female healer from Wuzhong in the Qing Dynasty].

The female healer is a special community in traditional Chinese medical professionals. Since the Song-Yuan Dynasties, although the literati class holding the social voices and the male healers acting as medical orthodoxy were always suspicious of the female healers' behaviors and their medical morality, and tarnished their images through all kinds of media. Meanwhile, the female healers were still badly needed on the account of recognition of distinction between sexes between both sexes due to the rising of neo-Confucianism. An excellent female healer could still earn wide respect from the society. Gu Dehua was a famous female healer from Wuzhong in the Qing Dynasty's Daoguang-Xianfeng period. By investigating Gu Delua's family conditions, deeds and works, and her career, the community of the female healers in the Ming-Qing Dynasties can be thus understood.

Analogous effects of recombinant human full-length amelogenin expressed by Pichia pastoris yeast and enamel matrix derivative in vitro.

OBJECTIVES: Amelogenins are proposed to be responsible for enamel matrix derivative (EMD)-induced periodontal regeneration; however, heterogeneity of amelogenins makes it challenging to purify the full-length proteins. This study has been carried out to express and purify a recombinant full-length human amelogenin protein (rHhAm175) in the eukaryotic yeast Pichia pastoris, and further compare biological responses of human periodontal ligament fibroblasts (PDLFs) to rHhAm175 and porcine EMD (pEMD). MATERIALS AND METHODS: Human cDNA encoding a 175-amino acid amelogenin was subcloned into the pPIC3.5K vector. The rHhAm175 expressed in P. pastoris GS115 (Mut+) was purified and characterized. We examined cell attachment, migration and proliferation responses of human PDLFs to rHhAm175 and pEMD respectively, and characterized associated changes of proliferation-related intracellular signalling molecules, including extracellular signal response kinase (ERK) and Akt kinases/protein kinase B (Akt/PKB) kinases. RESULTS: The purified rHhAm175 was confirmed to be molecular mass 22 021.13 Da, phosphorylated human amelogenin, and alone significantly promoted proliferation and migration of human PDLFs to an extent comparable to that of pEMD. Cell attachment was increased over the first 60 min incubation with rHhAm175 or pEMD. Both rHhAm175 and pEMD induced PDLF mitogenesis via extracellular signal response kinase (ERK1/2), but not by Akt kinases/protein kinase B (Akt/PKB). CONCLUSIONS: rHhAm175 modulated cell activities of human PDLFs, to a comparable extent as porcine EMD. These data suggest that rHhAm175 might be used to induce periodontal tissue regeneration.

Synchrotron photoionization mass spectrometry study of intermediates in fuel-rich 1,2-dimethoxyethane flame.

Intermediates in a fuel-rich premixed laminar 1,2-dimethoxyethane (DME) flame are studied by molecular beam mass spectrometry combined with tunable synchrotron vacuum ultraviolet photoionization. About 30 intermediate species are identified in the present work, and their mole fraction profiles are evaluated. The experimental results show that the formations of intermediates, both hydrocarbons and oxygenated hydrocarbons, are closely linked to the structure of fuel, which is consistent with the previous reports. Species produced from H atom abstraction and beta scission of DME usually have much higher concentrations than others. The oxygen atoms in DME are considered to act as partitions of the primary intermediates; therefore farther reactions among these primary intermediates are difficult to occur, resulting in absence of most large intermediate species.

[Effect of some nonintercalative antitumor drugs on the activity of calf thymus DNA topoisomerase I].

DNA topoisomerase I has been isolated from the nuclei of calf thymus by PEG fractionation and chromatography on P11 and on Bio-Rex 70. Either a positive or negative supercoiled pBR322 DNA can be relaxed by the enzyme. The activity of Topo I is Mg2+ and ATP independent. Some of nonintercalative antitumor drugs such as camptothecine, hydroxycamptothecine, cyclophosphamide, methotrexate and mitomycin C were found to inhibit the activity of Topo I. The results suggest that DNA Topo I can be used to screen new nonintercalative antitumor drugs as a target protein.