成人牙周炎治疗前后龈沟液蛋白质的电泳分析

目的通过分析成人牙周炎患者同一位点基础治疗前后１个月龈沟液（ｇｉｎｇｉｖａｌｃｒｅｖｉｃｕｌａｒｆｌｕｉｄ，ＧＣＦ）中蛋白成分的改变，以期发现能够反映牙周健康及疾病状况的特异蛋白。方法采用滤纸条法收集１２例成人牙周炎患者５６个位点ＧＣＦ样本，以十二烷基磺酸钠聚丙烯酰胺凝胶电泳（ＳＤＳＰＡＧＥ）法分离，ＩｍａｇｅＭａｓｔｅｒＴＭ电泳图象分析仪分析其中的蛋白质。结果治疗后蛋白区带数及非血清源低分子量１２０００，１００００蛋白的丰度及百分含量较治疗前显著减少（分别为Ｐ＜０００１和Ｐ＜００５），而３８０００蛋白百分含量呈增加趋势且与治疗前牙周探诊深度和ＧＣＦ量呈负相关（Ｐ＜００５）。结论分子量为１２０００，１００００的蛋白与牙周炎症有关；分子量３８０００的蛋白与疾病的好转有关     

平阳霉素引发细胞凋亡与MAPK信号转导通路的关联性

目的 探讨平阳霉素引发细胞凋亡与分裂原激活的蛋白激酶家族（mitogen-activated protein kinase,MAPK)信号转导通路的关联性。方法 采用Western印迹法（western blot)检测分裂原激活蛋白激酶的表达。结果 平阳霉素作用KB细胞，随作用时间延长或药物浓度增加，磷酸化细胞外信号调节激酶的表达越不明显；而p-38MAPK蛋白激酶的表达无明显变化。结论 平阳霉素引发细胞凋亡与分裂原激活的蛋白激酶家族信号转导通路有关。     

Effect of biofilm formation on virulence factor secretion via the general secretory pathway in Streptococcus mutans

Objectives

To investigate the role of SecA in protein secretion, and to evaluate the effect of biofilm formation on protein secretion in Streptococcus mutans.

Design

S. mutans strains UA159 and GS-5 were used in this study. Cells grown in biofilm and planktonic conditions were observed using immunogold electron microscopy. The mRNA levels of ftf, gtfB, gtfC, gtfD, Pac and secA were analysed in different growth conditions using real-time quantitative polymerase chain reaction. The levels of wall proteins and whole-cell protein extracts were examined using Western blot analysis.

Results

A microdomain colocalised with SecA and virulence factors such as Pac (AgI/II) and glucosyltransferase (GTF) was observed. The mRNA level of secA was upregulated in the biofilm condition. The level of protein expression of SecA and wall protein levels of GTF, fructosyltransferase (FTF) and Pac (AgI/II) in the biofilm condition were significantly higher than in the planktonic condition.

Conclusions

These data suggest that S. mutans utilises the Sec pathway to secrete virulence factor proteins such as Pac (AgI/II), GTF and FTF, and protein secretion occurred at a distinct microdomain. The level of SecA, the key factor in the Sec pathway, was influenced significantly by biofilm formation in S. mutans.     

变形链球菌在日托儿童口腔中水平传播的初探

目的 通过对日托儿童口腔中变形链球菌（S.mutans）水平传播的研究，为儿童龋的早期预防提供新思路。方法 选择32名3～4岁日托儿童，根据是否患龋分为有龋组和无龋组。用无菌牙签采集牙面菌斑，MSB琼脂培养，微量生化反应鉴定分离S.mutans菌落，纯培养后提取基因组DNA，用AP-PCR检测其基因多态性，对来自不同个体的具有相似AP-PCR扩增图谱的菌株再进行DNA指纹分析。结果 32名受检儿童中，变形链球菌的检出率为78.1%；有龋组和无龋组的变形链球菌检出率分别为100%和69.6%。在检出变形链球菌的25名儿童中，携带有2种及以上基因型的儿童占88%；有龋组为88.9%，无龋组为87.5%，OR值为1.143，二者之间的差异无统计学意义。DNA指纹分析表明，有2种基因型变形链球菌分别在2名儿童口腔中重复检出。结论 变形链球菌在日托儿童中可能存在水平传播，但其基因型检出数目与龋的发生关系不明显。     

Protein free diet feeding: effects on sympathetic activity and salivary evoked secretion in the submandibular gland of the rat

Protein restriction impairs the salivary flow rate and composition in human and rats. The aim of the present work was to establish the effect of low protein (casein 5%) and protein free (casein 0%) isocaloric diets on sympathetic activity and salivary evoked secretion in the submandibular gland (SMG) of the rat. After 21 days, rats fed casein 0% presented: (a) a significant shift to the left of the dose-response curves (DRC) to the autonomic agonists-norepinephrine (NE), methoxamine, isoproterenol (ISO) and methacholine; (b) increased food consumption (p<0.001); (c) decreased body (p<0.001) and SMG (p<0.001) weights maintaining SMG/body (w/w) relation; (d) enhanced submandibular alpha1-adrenoceptor number without changes in the apparent dissociation constant (Kd); (e) increased submandibular NE content (p<0.05) and phosphoinositoside hydrolysis (p<0.001); (f) decreased submandibular tyrosine hydroxylase activity (TH) (p<0.01). Casein 5% feeding increased food consumption (p<0.01) and reduced body weight (p<0.05). This protein restriction increased metacholine-evoked salivation, but it altered neither submandibular sympathetic activity nor sympathetic-induced salivary secretion as compared to the Control group (C) fed a similar diet containing 25.5% protein. Present results suggest that in the adult rat, a protein free diet during 21 days lowers SMG sympathetic and cholinergic activity leading to supersensitivity as revealed by up-regulation of alpha1-adrenergic receptor number and increased autonomic-evoked salivation.     

Protein carbonyl levels in serum and gingival crevicular fluid in patients with chronic periodontitis

OBJECTIVE: Evidence reveals the role of reactive oxygen species (ROS) in many pathologies including periodontitis. Protein carbonylation is the most widely used biomarker for oxidative damage to proteins, and reflects cellular damage induced by ROS. In this study protein carbonyl (PC) levels in serum and gingival crevicular fluid (GCF) in patients with chronic periodontitis (CP) was evaluated. MATERIALS AND METHODS: Thirty-three patients with CP and 24 healthy controls were included in the study. Following the clinical measurements and samplings, total protein levels in serum and GCF were determined by Bradford method, and serum and GCF PC levels were measured by modified Levine method. RESULTS: PC levels in serum and GCF were significantly higher in the CP group compared to the control group (p<0.05). In all subjects, serum and GCF PC levels showed statistically significant positive correlations with all clinical parameters (p<0.05). CONCLUSIONS: The results suggest that both systemic and local/periodontal protein carbonylation increase in CP compared to health and that elevated levels of PCs may be a sign of oxidative damage in periodontitis and correlate well with the periodontal status.     

Protein content of molar–incisor hypomineralisation enamel

Objectives

The aim of the study was to compare the relative amounts and nature of the proteinous content of sound and molar–incisor hypomineralisation (MIH) enamel.

Methods

TCA (20%) was used to dissolve the mineral phase and precipitate the proteins from enamel pieces sectioned from sound and MIH enamel. The protein content was estimated using a miniaturized version of the method of Lowry et al. Samples of the solubilised protein were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), stained with Coomassie Blue R250 and tryptic fingerprint/mass spectrometry (MS/MS) of bands in excised gel pieces used for protein identification.

Results

Compared to sound enamel, brown enamel showed a 15–21-fold higher protein content, and yellow and chalky enamel showed about 8-fold higher protein content. Tryptic fingerprint/MS performed on excised 50–70 kDa areas demonstrated serum albumin, type I collagen and antitrypsin to be common to all types of enamel. Yellow and brown enamel showed more abundant serum albumin and antitrypsin, and the presence of serum antithrombin. Albumin is reported to be an inhibitor of crystal growth, and antitrypsin and antithrombin inhibit kallikrein 4 proteolytic activity.

Conclusions

The combination of the effects of serum proteins on developing enamel may result in elevated proteinous content and reduced mineral content as seen in MIH enamel.     

459例试管婴儿备孕期高龄女性膳食蛋白质摄入现状分析

目的 了解试管婴儿备孕期高龄女性膳食蛋白质摄入现状。 方法 选取2018年9月至2019年9月在山东大学附属生殖医院拟行试管婴儿技术助孕的高龄备孕女性459例,利用食物频率法进行膳食调查,分析每日膳食蛋白质、氨基酸摄入量以及蛋白质膳食来源。 结果 被调查的459例备孕女性膳食蛋白质摄入量中位数为61.73 g/d,达到推荐摄入量的人群占65.14%,其中居住地来源于城镇和农村的备孕女性蛋白质摄入量中位数分别为62.76 g/d和60.35 g/d,二者间差异无统计学意义(P=0.119)。城镇备孕女性膳食蛋白质达到推荐摄入量的人群比例为70.56%,高于农村备孕女性(59.65%),差异有统计学意义(P=0.015)。459例备孕女性蛋白质食物来源以植物性食物为主,占63.08%,优质蛋白质占蛋白质供给量的33.66%;来源于谷薯类食物的蛋白质摄入量农村备孕女性高于城镇备孕女性,差异无统计学意义(P=0.070),来源于畜禽肉、鱼虾、奶类食物的蛋白质摄入量城镇备孕女性高于农村备孕女性,差异有统计学意义(P<0.05)。各种必需氨基酸评分在0.97~1.83。 结论 被调查的459例试管婴儿备孕期高龄女性膳食蛋白质摄入量适宜,蛋白质食物来源以植物性食物为主,必需氨基酸模式与WHO/FAO推荐模式接近;但部分人群存在蛋白质摄入不合理的情况,农村备孕女性动物蛋白摄入量有待进一步改善。     

点突变Uchl1不影响小鼠卵母细胞成熟

目的 通过观察突变蛋白与野生蛋白过量对卵母细胞成熟过程的影响,分析Uchl1在小鼠卵母细胞离体成熟中发挥的作用及其作用方式。方法 通过原核重组蛋白技术制备点突变（C90S和I93M）和野生型Uchl1蛋白,通过蛋白微量注射技术将突变蛋白与对照蛋白注射到未成熟卵母细胞,或体外培养液中添加突变蛋白与野生型蛋白,分析野生型Uchl1过量,或突变Uchl1-I93M蛋白添加,或泛素水解酶活性缺失的Uchl1-C90S突变蛋白添加,对于卵母细胞体外成熟的影响。结果 显微注射UCHL1融合蛋白的各组之间以及与注射PBS之间, GVBD率差异没有达到统计学显著性;同时培养液中添加Uchl1的GST融合蛋白,相对于无注射对照组,也没有统计学显著差异（P>0.05）。注射GST-C90S融合蛋白组少量GV期卵母细胞体外发育为MII期卵母细胞后呈现极体偏大于对照组。I93M点突变小鼠与WT小鼠比较,GV期卵母细胞体外GVBD率无显著差异。结论 在小鼠卵母细胞中,添加外源性Uchl1,或者有毒性作用的I93M突变体,或者水解酶活性结构改变的C90S突变体,均不影响卵母细胞成熟的GVBD进程。即使构建的I93M点突变小鼠卵母细胞GVBD率无异常。但是,其水解酶活性位点突变影响极体的形成。     

头孢噻肟结合中成药对婴幼儿肺炎C-反应蛋白的影响

目的:探讨头孢噻肟结合中成药对婴幼儿肺炎患儿血C-反应蛋白(CRP)水平的影响。方法:对未能住院的42例婴幼儿肺炎采用头孢噻肟结合中成药治疗,并对其治疗前及治疗7d后的血CRP水平、临床症状和体征等进行评估。结果:总有效率为81.0%;血CRP水平从治疗前的(45.27±15.70)mg.L-1降至(10.38±7.26)mg.L-1,前后比较有统计学差异(P<0.01)。结论:头孢噻肟结合中成药对婴幼儿肺炎患儿的血CRP有较好的干预效果,该方法治疗婴幼儿肺炎是可取的、有效的、安全的。