A comparison of enamelin and amelogenin expression in developing mouse molars

Amelogenin and enamelin are structural proteins in the enamel matrix of developing teeth. The temporal and spatial patterns of enamelin expression in developing mouse molars have not been characterized, while controversy remains with respect to amelogenin expression by odontoblasts and cementoblasts. Here we report the results of in situ hybridization analyses of amelogenin and enamelin expression in mouse molars from postnatal days 1, 2, 3, 7, 9, 14, and 21. Amelogenin and enamelin mRNA in maxillary first molars was first observed in pre-ameloblasts on the cusp slopes at day 2. The onsets of amelogenin and enamelin expression were approximately synchronous with the initial accumulation of predentin matrix. Both proteins were expressed by ameloblasts throughout the secretory, transition, and early maturation stages. Enamelin expression terminated in maturation stage ameloblasts on day 9, while amelogenin expression is still detected in maturation stage ameloblasts on day 14. No amelogenin expression was observed in day 21 mouse molars. Amelogenin and enamelin RNA messages were restricted to ameloblasts. No expression was observed in pulp, bone, or along the developing root. We conclude that amelogenin and enamelin are enamel-specific and do not directly participate in the formation of dentin or cementum in developing mouse molars.     

新型冠状病毒肺炎期间皮肤科医务人员的焦虑情绪分析

目的 调查新型冠状病毒肺炎疫情下皮肤科医务人员的焦虑情绪,以期为今后的心理疏导和临床工作提供依据。方法 采用随机抽样方法选取笔者医院皮肤科医务人员为研究对象,采用焦虑自评量表(SAS)评定患者焦虑程度,并对于检出的焦虑者进行综合心理干预。结果 皮肤科医务人员SAS评分为(40.66±7.84)分,焦虑症状检出率为14.93%,其中女性SAS评分高于男性,女性焦虑情绪检出率高于男性,护士SAS评分高于医生。检出焦虑的医务人员平均SAS评分在接受综合心理干预后由59.45±6.97降低至40.32±7.88(P＜0.001)。结论 基于新型冠状病毒肺炎疫情环境,皮肤科医务人员的心理健康也会受到一定程度的负面影响,女性和护士的焦虑检出率较高。以呼吸放松训练,正念疗法及音乐聆听三位一体的综合心理干预是应对焦虑,促进心理健康的可靠方法。     

20例ABO血型抗原表达异常样本的血型基因分析

目的 探讨20例样本ABO血型抗原表达减弱的分子生物学机制。方法 采用微柱凝集法及盐水试管法进行ABO血型血清学鉴定;对ABO基因第1-7外显子及其上游启动子区域PCR产物直接测序进行基因分型。结果 11例样本通过家系分析可以确定其基因型（1例ABO*A2.01/ABO*B.01,1例ABO*A2.01/ABO*O01.01,1例A1.02/B3.04,2例B3.04/O.01.01、2例B3.02/O.01.02,4例Bw.12/O.01.01）;3例样本在ABO基因启动子区域发生-35_-18位的碱基缺失,通过家系分析,提示该变异发生在B等位基因;1例样本在ABO基因启动子区域发生-119位C>T变异;1例样本发生第7外显子1054位点缺失碱基C;4例样本在ABO血型基因1-7外显子及其调控区域未发现变异。结论 启动子区域-119位C>T变异及Exon7 1054del变异可能是导致ABO血型抗原异常表达的新变异;部分ABO亚型可能与内含子异常或mRNA合成异常有关;本地区B亚型明显多于A亚型。     

Combined Effect of Smoking and Obesity on Coronary Heart Disease Mortality in Male Veterans: A 30-year Cohort Study

Objective Evidence is lacking regarding the combined effects of smoking and obesity on mortality from coronary heart disease in male veterans.This study aimed to explore the combined effect of smoking and obesity on coronary heart disease mortality in male veterans in China.Methods A cohort of 1,268 male veterans from 22 veteran centers in Xi’an(Shaanxi Province,China)were followed up once every 2 years from February 1,1987 to October 30,2016.The endpoint was death from any cause.The hazard ratio(HR)of each risk factor and the 95%confidence interval(CI)were calculated using a multivariate Cox proportional hazard model.Results The total follow-up was 24394.21 person-years;each subject was followed up for a mean duration of 19.24 years.By the end of the study,of the 1,268 veterans,889 had died,363 were alive,and 16 were lost to follow-up.Cox regression analysis results revealed that current smoking(HR:1.552,95%CI:1.074–2.243),obesity(HR:1.625,95%CI:1.024–2.581),and the combined effect of the two factors(HR:2.828,95%CI:1.520–5.262)were associated with coronary heart disease mortality.Conclusion Our results suggest that obese veterans who smoke might be an important target population for coronary heart disease mortality control.     

B-learning在进修医生胎儿超声心动图教学中的应用

胎儿超声心动图是筛查、诊断胎儿先天性心脏病最有效的方法,其作为一门高难度的新兴学科,从业者需要具备扎实的理论知识和规范的操作技能,学习和掌握起来较为困难。而来我院学习胎儿超声心动图的进修医生,往往存在自身知识水平参差不齐、学习时间紧、任务重等特点,传统教学模式难以达到其学习的目的。我们探索将传统教学与计算机及网络教学相结合即混合式学习(B-learning)运用到进修医生胎儿超声心动图教学中,采用案例式教学、问题导向教学、多媒体教学等多元化教学手段,激发进修医生学习的主动性、积极性,培养其分析、思考问题的能力,提高教学质量,进而提高进修医生超声筛查和诊断胎儿先天性心脏病的能力。     

凝血酶调节蛋白、纤溶酶原激活剂抑制物-1与儿童免疫性血小板减少症的相关性

目的探讨凝血酶调节蛋白(TM)、纤溶酶原激活剂抑制物-1(PAI-1)与儿童免疫性血小板减少症(IPT)的相关性。方法选取2018年9月~2019年12月期间的70例ITP患儿作为研究对象,设为ITP组。选取同期进行体检的儿童50例作为对照组。比较各组间血清TM、PAI-1水平及PLT。结果ITP组血清TM、PAI-1水平显著高于对照组,PLT显著低于对照组(P<0.05)。ITP组治疗后血清TM、PAI-1水平显著低于治疗前,PLT显著高于治疗前(P<0.05)。经过Pearson相关性分析,ITP患者血清TM、PAI-1水平与PLT均呈负相关(P<0.05)。结论血清TM、PAI-1水平与儿童IPT密切相关,可以作为临床疾病监测的辅助指标。     

Diversity,novelty, antimicrobial activity,and new antibiotics of cultivable endophytic actinobacteria isolated from psammophytes collected from Taklamakan Desert

Three hundred and twenty endophytic actinobacterial strains were isolated from psammophytes collected from Taklamakan Desert and identified. Among them, three strains already had been identified as new species of two genera and sixteen isolates showed relatively low 16S rRNA similarities < 98.6% to validly described species. Seventy-five of the isolates were selected as representative strains to screen antibacterial activity and mechanism. Forty-seven strains showed antagonistic activity against at least one of the indicator bacteria. Two Streptomyces strains produced bioactive compounds inducing DNA damage, and two Streptomyces strains produced bioactive compounds with inhibitory activity on protein biosynthesis. Notably, the strain Streptomyces sp. 8P21H-1 that demonstrated both strong antibacterial activity and inhibitory activity on protein biosynthesis was prioritized for exploring new antibiotics. Under the strategy of integrating genetics-based discovery program and MS/MS-based molecular networking, two new streptogramin-type antibiotics, i.e., acetyl-griseoviridin and desulphurizing griseoviridin, along with known griseoviridin, were isolated from the culture broth of strain 8P21H-1. Their chemical structures were determined by HR-MS, and 1D and 2D NMR. Desulphurizing griseoviridin and griseoviridin exhibited antibacterial activities by inhibiting translation.