Abstract：
:Khat-chewing has been associated with oral lesions including oral cancer, but the mechanisms leading to their development are not known. We hypothesized that khat interferes with the physiological processes of the oral mucosa, such as cell proliferation and differentiation, and aimed at investigating the effects of khat exposure on in vitro-reconstructed human normal buccal mucosa. Khat decreased cell proliferation, epithelial thickness, and cytokeratin 13 expression, while inducing premature expression of p21(Waf1/Cip1), transglutaminases, involucrin, and filaggrin. This suggests that khat is able to induce abnormal differentiation of the buccal epithelium. Khat-induced alterations were accompanied by increased levels of p38 and were reversed by p38 inhibition, pointing to p38 as the key player in this process. The morphological changes described herein mirror the in vivo changes previously described in khat users, and demonstrate for the first time that khat induces pathological alterations in human buccal mucosa, providing evidence that raises concerns about the effects of khat use on oral health.
journal_name
J Dent Resjournal_title
Journal of dental researchauthors
Lukandu OM,Neppelberg E,Vintermyr OK,Johannessen AC,Costea DEdoi
10.1177/0022034509354980subject
Has Abstractpub_date
2010-03-01 00:00:00pages
270-5issue
3eissn
0022-0345issn
1544-0591pii
0022034509354980journal_volume
89pub_type
杂志文章abstract：:Knoop hardness measurements of UV-polymerized dental composites showed that, at a certain depth below the surface, the degree of cure rapidly decreases. The depth of cure was found to be critically dependent on the UV source and exposure time used. A theoretical model was derived which was in quantitative accord with ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345800590050901
更新日期：1980-05-01 00:00:00
abstract：:The purpose of this investigation was to examine the inhibitory effects of aqueous extracts derived from the bark-containing sticks (Neem stick) of Azadirachta indica upon bacterial aggregation, growth, adhesion to hydroxyapatite, and production of insoluble glucan, which may affect in vitro plaque formation. Neem sti...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345960750021301
更新日期：1996-02-01 00:00:00
abstract：:Periodontal ligaments (PDLs) play an important role in remodeling the alveolar bond and cementum. Characterization of the periodontal tissue transcriptome remains incomplete, and an improved understanding of PDL features could aid in developing new regenerative therapies. Here, we aimed to generate and analyze a large...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034516645796
更新日期：2016-08-01 00:00:00
abstract：:A search was made for expression of genes for proline-rich proteins (PRPs) and other salivary-type proteins, including statherin and histatins, in taste-bud tissues of mice and primates because of previous genetic findings in mice (Azen et al., 1986) that Prp and taste genes for certain bitter substances are either th...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345900690110401
更新日期：1990-11-01 00:00:00
abstract：:The accumulated posteruptive tooth age was calculated for 212 children with Down's syndrome and 124 of their unaffected sibs. Posteruptive tooth age was shown to vary widely with different morphological permanent tooth types at the same chronological age. Girls in both groups had greater accumulated posteruptive tooth...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345750540033001
更新日期：1975-05-01 00:00:00
abstract：:An indirect extrusion capillary viscometer has been developed. This has been tested for nonsetting Newtonian fluids and was found to give results close to, but slightly lower than the actual viscosity. The same apparatus has been successfully applied to a non-Newtonian fluid to determine the dependence of viscosity on...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345760550021001
更新日期：1976-03-01 00:00:00
abstract：:Ten dental casting alloys were tested for alloy-element release into cell-culture medium, and this release was related to alloy composition, alloy microstructure, and alloy cytotoxicity (previously determined). Cell-culture medium was analyzed for alloy elements by flame atomic absorption. Concentrations of elements i...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345910700060301
更新日期：1991-06-01 00:00:00
abstract：:Apoptosis plays important roles in various stages of organogenesis. In this study, we hypothesized that apoptosis would play an important role in tooth morphogenesis. We examined the role of apoptosis in early tooth development by using a caspase inhibitor, z-VAD-fmk, concomitant with in vitro organ culture and tooth ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910608500610
更新日期：2006-06-01 00:00:00
abstract：:Previous studies showed that residual compressive stresses induced by thermal tempering retarded the growth of surface cracks in bilayered porcelain disks. The objectives of the present study were: (1) to determine whether thermal tempering by air blasting reduces the length of cracks induced by microhardness indentat...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345960750020301
更新日期：1996-02-01 00:00:00
abstract：:Administration of indomethacin inhibited the appearance of osteoclasts and bone resorption induced by experimental tooth movement in rats. Effects were limited to groups injected within 12 h after treatment. Prostaglandin E1 or E2 solutions injected in gingiva lying near the upper first molar caused the appearance of ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345800590101301
更新日期：1980-10-01 00:00:00
abstract：:The biocompatibility of two implant materials, vitallium and poly-methyl methacrylate (PMMA), was evaluated in an animal model in which bone formation and resorption are independent of each other. Neither material accelerated resorption, but formation was inhibited 12% by vitallium and 38% by PMMA. When three PMMA pre...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345810600010801
更新日期：1981-01-01 00:00:00
abstract：:In the past decade, medical genetic research has generated multiple discoveries, many of which were obtained via genome-wide association studies (GWASs). A major GWAS finding is that the majority of risk variants for complex traits map to noncoding regions. This has resulted in a paradigm shift in terms of the interpr...
journal_title：Journal of dental research
pub_type： 杂志文章,评审
doi：10.1177/0022034517720403
更新日期：2017-10-01 00:00:00
abstract：:To identify salivary biomarkers of periodontal diseases, we used plaque-resistant and -susceptible rats as animal models. The levels of salivary cystatin S in saliva, salivary glands, and gingiva were tested in Nembutal-anesthetized young and adult plaque-resistant and -susceptible rats of both sexes with and without ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345980770110801
更新日期：1998-11-01 00:00:00
abstract：:Sense of coherence (SOC) has been related to oral health behaviors and oral-health-related quality of life (OHRQoL) in observational studies. This cluster-randomized trial aimed to test the effect of an intervention to enhance SOC on OHRQoL in children. Twelve primary schools were randomly allocated to intervention an...
journal_title：Journal of dental research
pub_type： 杂志文章,随机对照试验
doi：10.1177/0022034512459757
更新日期：2013-01-01 00:00:00
abstract：:Bone remodeling is a complex process regulated by several mediators. Recent work has revealed that cytokines and growth factors have significant effects on bone cell metabolism. However, little information is available concerning the production of cytokines during orthodontic tooth movement in human subjects, and ther...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345960750010801
更新日期：1996-01-01 00:00:00
abstract：:A new type of hydraulic cement has been developed. This cement consists of a mixture of cement powder and setting agent powder and therefore has only to be kneaded with a little amount of water when being used. ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345790580050601
更新日期：1979-05-01 00:00:00
abstract：:Light propagation in human dentin exhibits a strong directional dependence featuring the long-known optical magnification property. We hypothesized that this anisotropic effect is caused by multiple scattering at the dentin tubules, and not by fiberoptic effects, as had been previously assumed. We performed measuremen...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910608501017
更新日期：2006-10-01 00:00:00
abstract：:The aim of this study was to examine the association between the bone mass (bone mineral content [BMC]) and hypomineralized second primary molars (HSPMs)/molar incisor hypomineralization (MIH) in 6-y-old children. This cross-sectional study was embedded in the Generation R Study, a population-based prospective cohort ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034515625470
更新日期：2016-04-01 00:00:00
abstract：:An analysis of the relationship between creep and microstructural characteristics of several gamma2-containing amalgams showed the grain size of the Ag-Hg phase (gamma1) to be a predominant factor influencing creep. When gamma1 grain size is increased, creep is reduced. ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345770560121401
更新日期：1977-12-01 00:00:00
abstract：:Pulpal blood flow was determined in 32 dogs ranging in age from 6 weeks to 18 months by the isotope fractionation method incorporating diffusible and nondiffusible tracers. Dogs were placed into selected age groups by the developmental status of the canine teeth. For the teeth sampled, the maxillary first, second, and...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345770560102601
更新日期：1977-10-01 00:00:00
abstract：:Loss of hybrid layer integrity compromises resin-dentin bond stability. Matrix metalloproteinases (MMPs) may be partially responsible for hybrid layer degradation. Since chlorhexidine inhibits MMPs, we hypothesized that chlorhexidine would decelerate the loss of resin-dentin bonds. Class I preparations in extracted th...
journal_title：Journal of dental research
pub_type： 杂志文章,随机对照试验
doi：10.1177/154405910708600115
更新日期：2007-01-01 00:00:00
abstract：:Pilocarpine (P) is of potential utility in the treatment of xerostomia. Because optimal development of P dosage forms for humans requires that its pharmacokinetics and pharmacodynamics be defined, this intravenous study of its disposition and associated salivary responses was performed. In a hospital setting, two heal...
journal_title：Journal of dental research
pub_type： 临床试验,杂志文章
doi：10.1177/00220345950740120701
更新日期：1995-12-01 00:00:00
abstract：:Current challenges in adhesive dentistry include over-hydrophilic bonding formulations, which facilitate water percolation through the hybrid layer and result in unreliable bonded interfaces. This study introduces nanogel-modified adhesives as a way to control the material's hydrophobic character without changing the ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034511426573
更新日期：2012-02-01 00:00:00
abstract：:The acquired enamel pellicle is an oral, fluid-derived protein layer that forms on the tooth surface. It is a biologically and clinically important integument that protects teeth against enamel demineralization, and abrasion. Tooth surfaces are exposed to different proteinaceous microenvironments depending on the enam...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034516680771
更新日期：2017-04-01 00:00:00
abstract：:The molecular mechanisms that maintain the equilibrium of odontoblast progenitor cells in dental pulp are unknown. Here we tested whether homeostasis in dental pulp is modulated by Twist-1, a nuclear protein that partners with Runx2 during osteoblast differentiation. Our analysis of Twist-1(+/-) mice revealed phenotyp...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910708601007
更新日期：2007-10-01 00:00:00
abstract：:Interfacial bonding and stability of gamma-methacryloxypropyltrimethoxysilane with silica surfaces have been studied by means of infrared spectroscopy. The addition of n-propylamine enhances silanization of gamma-methacryloxypropyltrimethoxysilane to silica surfaces in normal aliphatic hydrocarbons, and cyclohexane yi...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345820610121301
更新日期：1982-12-01 00:00:00
abstract：:Dental porcelains rely on the high-thermal-expansion mineral leucite to elevate their bulk thermal expansion to levels compatible with dental PFM alloys. The microcracks that form around these leucite particles when cooled during porcelain manufacture are a potential source of change in bulk porcelain thermal expansio...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345960750070801
更新日期：1996-07-01 00:00:00
abstract：:In an attempt to make a dynamic study of the isoelectric point and the chargeability of human dental enamel, an electrochemical approach was utilized. Zeta potential of three kinds of the enamel was measured by a streaming potential method. As a result, these isoelectric points could be decided. ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345780570022701
更新日期：1978-02-01 00:00:00
abstract：:Stress-relaxation measurements were performed on specimens of radicular human dentin. The relaxation modulus showed a linear dependence on the logarithm of time and the approximation to the logarithmic distribution function of relaxation times was used to predict the behavior of other viscoelastic properties. This exp...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345750540061801
更新日期：1975-11-01 00:00:00
abstract：:Erupting first permanent molars of 5 1/2 to 6 1/2 year-olds are eminently suited for the clinical testing of potential caries-inhibiting techniques. Due to the rapid onset of caries in these teeth, accurate monitoring of new materials/regimes can be instituted and meaningful data obtained within one year of trial comm...
journal_title：Journal of dental research
pub_type： 临床试验,杂志文章
doi：10.1177/002203457705600301011
更新日期：1977-10-01 00:00:00
