One germline mutation of PTCH gene in a Chinese family with non-syndromic keratocystic odontogenic tumours

Keratocystic odontogenic tumours (KOCTs) are common benign cystic tumours that arise sporadically or associated with nevoid basal cell carcinoma syndrome (NBCCS). PTCH mutation can be found in sporadically or NBCCS associated KOCTs. Few PTCH mutations in families with non-syndromic KOCTs have been reported. Through PCR and gene sequence analysis, the authors discovered one missense mutation c.3277G>C in exon 19 of PTCH gene in a Chinese family with non-syndromic KOCTs. This mutation causes one highly conserved glycine residue transit to arginine on the 10th transmembrane region of PTCH protein. This work revealed that the missense mutation of PTCH is the causative and dominant gene of KOCTs in this family.     

Periodontal and oral microbiological status of an adult population undergoing haemodialysis: a cross-sectional study

OBJECTIVES: The aim of this cross-sectional study was to evaluate the periodontal status and oral microbiological patterns of a population with end-stage renal disease (ESRD), undergoing haemodialysis (HD). DESIGN: This was a cross-sectional study, involving 52 patients from the Nephrology Department and 52 matched control subjects. MATERIALS AND METHODS: The subjects had a periodontal clinical examination; subgingival plaque samples were taken and analysed using a semiquantitative polymerase chain reaction (PCR) test to detect Porphyromas gingivalis, Tannerella forsythia, Prevotella intermedia, Prevotella nigrescens and Actinobacillus actinomycetemcomitans. Subgingival plaque and saliva samples were studied for Candida and Enterobacteriaceae. MAIN OUTCOME MEASURES: Most of the 104 subjects had some degree of loss of periodontal attachment (LPA) > or =3 mm [11 (10.5%) had severe LPA; 16 (15.4%) moderate LPA; and 64 (61.5%) mild LPA]. Only 13 subjects (12.5%) presented good periodontal health. Results: No statistically significant differences were found between the HD patients and the control group regarding bleeding index, number of teeth, or percentage of LPA > or =3 mm. However, a statistically significant difference was seen in the degree of oral hygiene. CONCLUSIONS: On the basis of the findings presented here, we cannot associate ESRD with more severe periodontal destruction. Although HD patients presented a higher number of periodontopathic microorganisms than the matched controls, a prolonged duration of HD did not bear a statistically significant relationship with the percentage of sites with LPA > or =3 mm, specific microbiota or composition of biofilm.     

PCR method is essential for detecting Mycobacterium tuberculosis in oral cavity samples

Tuberculosis is a re-emerging infectious disease, and infection by Mycobacterium tuberculosis has been increasing in immunocompromised hosts, including elderly persons. M. tuberculosis-infected persons may receive dental treatment. To evaluate the risk of M. tuberculosis infection in dental clinics, we examined the detection rates of M. tuberculosis in sample of mixed saliva, dental plaque, extracted teeth, caries lesions, and denture plaque by nested polymerase chain reaction (PCR). The detection rates by PCR in samples from mixed saliva, dental plaque, caries lesions and denture plaque obtained from tuberculosis patients were 98.0%, 92.0%, 89.0%, and 100%, respectively. The detection rates by the culture method were 17.3%, 2.0%, 0%, and 0%, respectively. M. tuberculosis also was detected from the nontuberculous mycobacteria-infected group. Strains of Actinomyces naeslundii, Porphyromonas gingivalis, and Fusobacterium nucleatum inhibited the growth of clinical strains of M. tuberculosis, but strains of Streptococcus mutans, Streptococcus sanguinis, and Actinobacillus actinomycetemcomitans did not. The present study concludes that the PCR method is essential for detecting M. tuberculosis in oral samples.     

Repeat expansion and methylation-sensitive triplet-primed polymerase chain reaction for fragile X mental retardation 1 gene screening in institutionalised intellectually disabled individuals

INTRODUCTIONFragile X syndrome (FXS) is the most prevalent X-linked intellectual disability (ID) and a leading genetic cause of autism, characterised by cognitive and behavioural impairments. The hyperexpansion of a CGG repeat in the fragile X mental retardation 1 (FMR1) gene leads to abnormal hypermethylation, resulting in the lack or absence of its protein. Tools for establishing the diagnosis of FXS have been extensively developed, including assays based on triplet-primed polymerase chain reaction (TP-PCR) for detection and quantification of the CGG trinucleotide repeat expansion, as well as determination of the methylation status of the alleles. This study aimed to utilise a simple, quick and affordable method for high sensitivity and specificity screening and diagnosis of FXS in institutionalised individuals with ID.METHODSA total of 109 institutionalised individuals at the Center for Social Rehabilitation of Intellectual Disability Kartini, Temanggung, Central Java, Indonesia, were screened in a three-step process using FastFrax™ Identification, Sizing and Methylation Status Kits.RESULTSTwo samples that were classified as indeterminate with respect to the 41-repeat control at the identification step were subsequently determined to be non-expanded by both sizing and methylation status analyses. Two samples classified as expanded at the identification step were determined to carry full mutation expansions > 200 repeats that were fully methylated using sizing and methylation status analyses, respectively, yielding a disease prevalence of 1.83%.CONCLUSIONRepeat expansion and methylation-specific TP-PCR is practical, effective and inexpensive for the diagnosis of FXS, especially in high-risk populations of individuals with ID of undetermined aetiology.     

幽门螺杆菌在牙髓中的分布研究

目的：检测人牙髓标本中Hp的存在情况，探计Hp与牙髓病变的相关性以及Hp的传播途径和传播方式。方法：本实验分为5组，共计79例标本，前4组取根髓，第5组取龈下牙石。采用聚合酶链反应(PCR)和Hp快速诊断试剂盒两种方法检测不同病情下人牙髓和牙石标本中的Hp。结果：经x^2检验各牙髓组间Hp检出率无明显性差异；而牙髓组与龈下牙石组间Hp检出率均有显著性差异。结论：发现在人牙髓中存在Hp，牙髓中幽门螺杆菌的存在可能是Hp不易清除和相关疾病易于复发的原因。     

石蜡包埋涎腺肿瘤组织中人乳头瘤病毒的分型检测

目的 探讨人乳头瘤病毒(HPV)16型、18型与涎腺肿瘤病因学之间的关系.方法 采用型特异性引物PCR法对44例涎腺肿瘤组织标本中31例HPV检测阳性的组织DNA进行HPV分型检测.结果 检出HPV16 E7阳性率为13.64%,HPV18 E7阳性率为47.72%;涎腺肿瘤组织中HPV18 E7阳性率明显高于HPV16 E7阳性率;恶性肿瘤组中HPV16 E7、HPV18 E7阳性率显著高于良性肿瘤组(P<0.05).结论 HPV 16型、18型E7基因可能在恶性肿瘤的发生中起作用,其中HPV18感染与涎腺肿瘤的发生可能更密切.     

儿童口腔唾液中牙周病病原菌的检测

目的:确立儿童唾液中牙周可疑病原菌检测方法,了解牙周病原菌在儿童口腔中的分布。方法:利用细菌16SRNA设计10种牙周病原菌PCR引物,采用PCR技术检测291名儿童唾液中牙周病原菌。结果:唾液中共有9种病原菌被检出。检出率分别为:生痰二氧化碳噬纤维菌(C.s)75.9%,黄褐二氧化碳噬纤维菌(C.o)72.8%,伴放线放线杆菌(A.a)64.6%,啮蚀艾肯氏菌(E.c)48.5%,直肠弯曲菌(C.r)45.0%,变黑普氏菌(P.n)29.0%,福赛拟杆菌(B.f)22.0%,中间普氏菌(P.i)5.2%,牙龈卟啉单胞菌(P.g)5.2%,未检出齿垢密螺旋体(T.d)。细菌检出率与性别无关,不同年龄组总体检出率无统计学差异。P.g只在8岁以上儿童中检出。结论:通过PCR方法可以简单、快速地检测牙周病原菌在唾液中的分布,牙周病原菌的检出为研究儿童牙周病发病提供了重要的理论依据。     

Comparison of different techniques of quantitative PCR for determination of Streptococcus mutans counts in saliva samples

Saliva samples from 16 children with current caries activity were investigated for Streptococcus mutans using three different PCR techniques, and the results were compared with those of selective cultivation on mitis salivarius agar with bacitracin (MSB) (I, II: LightCycler - competitive PCR end-point analysis; III: LightCycler - kinetic real-time analysis; IV, V: block cycler - competitive PCR end-point analysis; VI: cultivation on MSB agar). In groups I, III, IV and VI the saliva samples were analyzed directly. A DNA preparation before PCR with added competitors was carried out in groups II and V to exclude the influence of PCR inhibitors. The coefficients of correlation ranged from 0.97 to 0.98 among the competitive PCR methods, 0.8 to 0.85 for competitive vs. real-time PCR and 0.5 to 0.65 for PCR vs. cultivation methods. Competitive PCR on the real-time instrument was found to be more rapid than, comparably sensitive to, but less reproducible than competitive PCR on a block cycler.     

变形链球菌在父子间传播的研究

目的　本实验应用随机引物聚合酶链反应法 (AP PCR)对父子间变链的传播进行研究 ,以期为龋病预防提供新思路和理论依据。方法　随机选取中国沈阳一个幼儿园 10名 3～ 5岁的儿童及其父亲作为研究对象 ,取父亲非刺激性全唾液并刮取儿童牙菌斑 ,进行细菌培养 ,用酚 -氯仿法抽提细菌DNA ,进行PCR反应 ,电泳。结果　儿童共分离出 16个基因型 ,3个与父亲的一致 ,占 18.8%。结论　在中国家庭父子间存在变链传播     

分体可调式止鼾器治疗OSAS的临床研究

目的：探讨分体可调式止鼾器治疗阻塞性睡眠呼吸暂停综合征（OSAS）的效果。方法：35例OSAS患者制作分体可调式矫治器，采用多导睡眠仪监测患者戴用前后呼吸紊乱指数（AHI），呼吸暂停指数（AI），低通气指数（HI）和SaO2指标变化，进行标准化问卷调查。结果：戴用矫治器前后对比，32例呼吸暂停低通气指数下降50％以上；呼吸暂停指数和低通气指数分别降低81．17％和49．45％（P〈0．01），夜间最低血氧饱和度明显升高（P〈0．01）．患者睡眠质量均有显著改善，鼾声均消失或明显减轻．结论：分体可调式止鼾器治疗轻、中度OSAS疗效明显。