Novel ERCC2 variant in trichothiodystrophy infant: the first case report in China.

Background: Trichothiodystrophy (TTD) is a rare, autosomal recessive, multisystem disorder most commonly caused by variants in ERCC2.

Case Presentation: Here, we describe the first Chinese patient with a novel variant in ERCC2. A male infant, who was born to a healthy non-consanguineous couple, exhibited brittle hair, hair loss ichthyosis, eczema, retinal pigmentation and hypospadias.

Comparative characterization of stem cells from human exfoliated deciduous teeth and dental pulp stem cells.

Objective: This study focused on the characterization of stem cells from human exfoliated deciduous teeth (SHED) in comparison with dental pulp stem cells (DPSCs) to certify SHED as a key element in tissue engineering.

Methods: In the present study, SHED and DPSCs were assayed for their cell surface antigens and proliferation by measuring the cell cycles, growth rates, Ki67-positive efficiencies, and colony-forming units (CFUs). The evaluation of multi-differentiation was performed using alizarin red and oil red O and real-time PCR in vitro.

In vitro study of the effects of fluoride-releasing dental materials on remineralization in an enamel erosion model.

Objectives: This study was conducted to compare the remineralization effects of five regimens on the loss of fluorescence intensity, surface microhardness, roughness and microstructure of bovine enamel after remineralization. We hope that these results can provide some basis for the clinical application of these materials.

Methods: One hundred bovine incisors were prepared and divided into the following five groups, which were treated with distinct dental materials: (1) Clinpro™ XT varnish (CV), (2) F-varnish (FV), (3) Tooth Mousse (TM), (4) Fuji III LC(®) light-cured glass ionomer pit and fissure sealant (FJ) and (5) Base Cement(®) glass polyalkenoate cement (BC).

Targeting nicotinic acetylcholine receptor to treat smoking-related periodontitis.

Tobacco smoking is considered to be one of the major risk factors for periodontitis. Nicotine, the major component in tobacco smoke, has been considered playing an important role in tobacco-related morbidity by acting through the nicotinic acetylcholine receptors (nAChRs) expressed by non-neuronal cells. Recently studies found that nAChRs could be expressed on oral gingival and periodontal tissues.

Changes of the unique odontogenic properties of rat apical bud cells under the developing apical complex microenvironment.

Aim: To characterize the odontogenic capability of apical bud and phenotypical change of apical bud cells (ABCs) in different microenvironment.

Methodology: Incisor apical bud tissues from neonatal SD rat were dissected and transplanted into the renal capsules to determine their odontogenic capability. Meanwhile ABCs were cultured and purified by repeated differential trypsinization.

[Expression feature and bioinformatic analysis of molar root patterning gene 1].

Objective: To examine the expression of molar root patterning gene 1 (Mrp1) and predict the Mrp1 structure by bioinformatics analysis.

Methods: A pair of Mrp1-specific PCR primers were designed, and RT-PCR method was used to study the mRNA's expression pattern in rat molar root and other organs. Gene positioning and other protein sequence prediction were carried out by chromosome analysis and other bioinformatics analysis.

[Effects and molecular mechanism of nicotine on odontoblasts].

Objective: To observe the effects of nicotine on the proliferation of odontoblasts and explore the possible mechanism.

Methods: Odontoblasts MDPC-23 were cultured, inoculated and divided into two groups randomly. With no stimuli added for the control group, the experimental group was stimulated by 100 microg/mL nicotine.

Identification of a novel missense mutation of MSX1 gene in Chinese family with autosomal-dominant oligodontia.

Objectives: Oligodontia is defined as the congenital absence of 6 or more permanent teeth excluding the third molar. The occurrence of non-syndromic still remains poorly understood, but in recent years some cases have been reported where mutations or polymorphisms of PAX9 and MSX1 had been associated with non-syndromic oligodontia. The objective of the present work was to study the phenotype and genotype of three generations of a Han Chinese family affected by non-syndromic autosomal-dominant oligodontia.

[Regulation of osteopontin expression in odontoblasts by upstream stimulatory factor 1].

Objective: To investigate the regulation effects of upstream stimulatory factor 1 (USF1) on osteopontin expression in odontoblasts.

Methods: Odontoblast MDPC-23 was cultured and stably transfected with PCMV-USF1 or A-USF plasmids. Total RNA was extracted and osteopontin expression examined by semi-quantitative RT-PCR.

[Expression, subcellular localization and nuclear translocation of transcription factor up stream stimulatory factor-1 in odontoblasts].

Objective: To examine the expression and subcellular localization of transcription factor USF1 in odontoblasts and investigate whether nuclear translocation occurs under stimuli.

Methods: Odontoblasts MDPC-23 were cultured on coverslips and divided into 2 groups. Group 1 received no stimuli, and group 2 was stimulated by nicotine with various concentrations respectively for 1h.

ADAM28 participates in the regulation of tooth development.

Disintegrin and metalloprotease (ADAM) proteins are a family of membrane-anchored glycoproteins with diverse functions in fertilisation, development, neurogenesis and protein ectodomain shedding. ADAM28 is a newly discovered member of the ADAM family in humans and murine with autocatalytic activity. Recently, the authors screened ADAM28 genes from patients with congenital hypoplasia of tooth root, and studied the relationship between ADAM28 and tooth development.

[Effects of ADAM28 AS-ODN on proliferation and AKPase of HDFCs].

Purpose: To study the effects of ADAM28 antisense oligodeoxynucleotide (AS-ODN) on proliferation of human dental follicle cells (HDFCs) and activity of alkaline phosphatase (AKPase).

Methods: Cell culture, gene transfection, MTT chromatometry and enzyme kinetics methods were used to detect the possible mechanisms of ADAM28 AS-ODN on proliferation, differentiation of HDFCs and effect of the activity of AKPase. Statistical significance was assessed by multiple comparison (q test, SNK) in one-way analysis of variance (ANOVA).

[In situ hybridization analysis of USF1 mRNA expression in odontoblasts].

Objective: To detect and verify USF1 mRNA expression in odontoblasts.

Methods: T-USF1 clone prepared previously was used as template and the desired USF1 cDNA segment was amplified by PCR with specific primers. The segment was labeled with digoxin as a probe and in situ hybridization was performed on the mounting of odontoblasts.

[Changes of dentin, dental pulp and periodontium tissue in tail-suspended rats].

Objective: To investigate the metabolic changes of calcium and phosphorus in dentin, dental pulp and periodontium in tail-suspended rats, and the functions of TGF-beta 1, c-fos, collagen-I and collagen IV in dentin, dental pulp and periodontium.

Method: Relative percentage contents of Ca, P in dentin, dental pulp and periodontium were measured with scanning electron microscope and energy spectrum analytical system in 3 groups of rats. The expression of TGF-beta 1, c-fos, collagen-I and collagen IV were also observed.