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OBJECTIVES: The purpose of this study was to measure the effectiveness of the cervical headgear for distalizing first permanent maxillary molars in relation to hours of use. METHODS: This was a one-centre, prospective, clinical study conducted at the Department of Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece. Participants (Nâ =â 26; 17 females, 9 males) were patients with no history of orthodontic treatment, no syndromes or clefts, and Angle's Class II malocclusion, where the treatment plan included a cervical headgear. They were instructed to wear the appliance for at least 12 h per day. A TheraMon® microsensor was embedded in the headgear's strap to objectively measure wear-time. To measure tooth movement, pre- and post-treatment digital models were superimposed, using the palate as a reference area; translation and rotation were measured along three axes. Superimposition and movement measurements were made with the Viewbox 4 software. RESULTS: Average treatment time and headgear wear were 130 days and 55 days, respectively, i.e. 10.1 h/day. During this period, distal movement averaged 1.75 mm with high variability (min 0.2 mm, max 4.5 mm). Distal tipping and rotation had an average of approximately 5 °C. Cumulative headgear wear was significantly correlated with distal movement (r2 = 0.32, Pâ <â .002), distal tipping (r2 = 0.27, Pâ <â .01), and distal rotation around the long axis of the tooth (r2 = 0.20, Pâ <â .05). CONCLUSION: Compliance is critical for having a successful clinical outcome. Distalization of the molar with a cervical headgear is correlated with the cumulative hours of appliance use, with hours per day being a weaker predictor.
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Má Oclusão Classe II de Angle , Aparelhos Ortodônticos , Masculino , Feminino , Humanos , Estudos Prospectivos , Cefalometria , Má Oclusão Classe II de Angle/terapia , Técnicas de Movimentação Dentária , Maxila , Dente Molar , Cooperação do Paciente , Desenho de Aparelho Ortodôntico , Aparelhos de Tração ExtrabucalRESUMO
INTRODUCTION: The study aimed to assess (1) the effect of the treatment with cervical headgear on patients' sleep-related attributes and well-being and (2) whether these sleep-related parameters (ie, sleep quality and quantity) were associated with patients' compliance during the orthodontic treatment. METHODS: The study protocol was based on a prospective longitudinal quasi-experimental design. Participants (n = 26; 9 males; mean age, 12.4 ± 1.68 years) were patients in the Postgraduate Orthodontic Clinic, National and Kapodistrian University of Athens. All patients received treatment with a cervical headgear having an embedded TheraMon microsensor. Sleep was assessed by wrist-worn actigraphy for 59 ± 19 days. The Epworth Sleepiness Scale was used to assess average daytime sleepiness, whereas we used the Athens Insomnia Scale for insomnia symptoms. Oral health-related quality of life (OHRQOL) was assessed by the Oral Health Impact Profile (OHIP-14). RESULTS: Patients slept on average 7.35 ± 0.42 h/d. Compared with the lowest sleep duration recommended for their age group, patients had an average chronic sleep deficit of 1.40 ± 0.49 h/d. Patients wore the headgear 90.9% of the days for 10.40 ± 4.17 h/d. However, only 7 (28%) patients reached or exceeded the wear-time recommendation of 12 h/d. In contrast, 2 (8%) patients wore headgear <5 h/d, 11 (44%) 5-10 h/d, and 12 (48%) patients wore headgear >10 h/d. Aggregated by participants, the median Epworth Sleepiness Scale score during the study was 3.40 (interquartile range [IQR], 4.85; range, 0.2-13.6), the median Athens Insomnia Scale score was 3.00 (IQR, 4.25; range, 0-7), and the median Oral Health Impact Profile score was 1.40 (IQR, 4.17; range, 0.0-20.8). Compared with patients who wore the orthodontic appliance >7.8 h/d, patients who wore it <7.8 h/d had worse average daytime sleepiness (P = 0.050) and worse OHRQOL (P = 0.019). CONCLUSIONS: Orthodontic treatment with cervical headgear has no substantive negative effect on sleep attributes (quantity and quality), average daytime sleepiness and OHRQOL. However, poor compliance with orthodontic treatment seems to be associated with higher levels of daytime sleepiness.
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Distúrbios do Sono por Sonolência Excessiva , Distúrbios do Início e da Manutenção do Sono , Masculino , Humanos , Criança , Adolescente , Estudos Prospectivos , Qualidade de Vida , Sonolência , SonoRESUMO
Mass Spectrometry (MS) is one of the fastest-developing methods in analytical instrumentation. As a highly sensitive, universal detector, it can identify known and unknown compounds, which can indeed be found in a minimal concentration. This review aims to highlight the significant milestones in MS applications in dentistry during recent decades. MS can be applied in three different fields of dentistry: (1) in research of dental materials and chemical agents, (2) in laboratory analysis of biospecimens, and (3) as a real-time diagnostic tool in service of oral surgery and pathology. MS applications on materials and agents may focus on numerous aspects, such as their clinical behavior, possible toxicity, or antimicrobial properties. MS is also a valuable, non-invasive tool for biomarkers' detection in saliva and has found great application in -omics technologies as it achieves efficient structure-finding in metabolites. As metabolites are located beyond the central dogma, this technique can provide a complete understanding of cellular functions. Thus, it is possible to determine the biological profile in normal and pathological conditions, detect various oral or systematic diseases and conditions, and predict their course. Lastly, some promising advances concerning the surgical approach to potentially oral malignant or malignant disorders exist. This breakthrough method provides a comprehensive approach to dental materials research and biomarker discovery in dental and craniofacial tissues. The current availability of various 'OMIC' approaches paves the way for individualized dentistry and provides suggestions for clinical applications in the point-of-care hubs.
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The enzymatic activity of APOBEC3B (A3B) has been implicated as a prime source of mutagenesis in head and neck squamous cell carcinoma (HNSCC). The expression of Protein Kinase C α (PKCα) and Nuclear Factor-κΒ p65 (NF-κΒ p65) has been linked to the activation of the classical and the non-canonical NF-κB signaling pathways, respectively, both of which have been shown to lead to the upregulation of A3B. Accordingly, the aim of the present study was to evaluate the expression of PKCα, NF-κΒ p65 and A3B in non-HPV related oral and oropharyngeal squamous cell carcinomas (SCC), by means of immunohistochemistry and in silico methods. PKCα was expressed in 29/36 (80%) cases of oral and oropharyngeal SCCs, with 25 (69%) cases showing a PKCα+/A3B+ phenotype and only 6/36 (17%) cases showing a PKCα-/A3B+ phenotype. Εxpression of NF-κB p65 was seen in 33/35 (94%) cases of oral and oropharyngeal SCCs, with 30/35 (86%) cases showing an NF-κB p65+/A3B+ phenotype and only 2/35 (6%) cases showing an NF-κB p65-/A3B+ phenotype. In addition, mRNA expression analysis, using the UALCAN database, revealed strong expression of all three genes. These findings indicate that the expression of A3B is associated with PKCα/NF-κB p65 expression and suggest a potential role for the PKC/NF-κB signaling pathway in the development of oral and oropharyngeal cancer.
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Palatal rugae constitute significant morphological landmarks, with wide clinical applications in forensics, insertion of mini-screws, and superimposition. Their morphology has been studied mainly with indices relevant to their qualitative characteristics. The present paper aims at presenting a new quantitative method to evaluate their complexity, by means of box-counting fractal dimension analysis, and to investigate its inter- and intra-rater reliability. Twenty maxillary plaster models were scanned for the needs of this study. A sequence of steps, including cropping of the mesh, ball pivoting, distance mapping and fractal dimension analysis, performed with Viewbox 4 software, was followed. Box-counting fractal dimensions were calculated as a measure of rugae's complexity. Inter- and intra-rater reliability were investigated, using Bland-Altman analysis. Fractal dimensions ranged from 1.274 to 1.491 (average: 1.412). Bland-Altman analysis of inter- and intra-examiner reliability demonstrated that the 95% limits of agreement ranged from - 0.012 to 0.011 and from - 0.004 to 0.004, respectively. The method is reliable and can be applied in research and forensics. It offers comprehensive evaluation of the rugae's complexity and a complete set of information about their outlines and height profiles, with minimum user intervention.
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Fractais , Maxila , Reprodutibilidade dos Testes , SoftwareRESUMO
Molar incisor hypomineralization is a complex developmental enamel defect that affects the permanent dentition of children with significant functional and aesthetic implications. Saliva is an ideal diagnostic tool and ensures patients' compliance by diminishing the discomfort especially in pediatric population. Lately, salivary proteome analysis has progressively evolved in various biomedical disciplines. As changes in saliva composition are associated with oral diseases, it is reasonable to assume that the saliva proteome of MIH-affected children might be altered compared to healthy children. This study analyzed the human and microbial salivary proteome in children with MIH in order to identify salivary markers indicative of the pathology. The conducted proteomic analysis generated a comprehensive dataset comprising a total of 1515 high confidence identifications and revealed a clear discrimination between the two groups. Statistical comparison identified 142 differentially expressed proteins, while the pathway analysis indicated deregulation of inflammation, immune response mechanisms, and defense response to bacteria in MIH patients. Bacterial proteome analysis showed a lower diversity for the microbial species, which highlights the dysbiotic environment established in the MIH pathology.
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Mosaicism, a state in which an individual has two or more genetically distinct populations of cells in the body, can be difficult to detect because of either mild or atypical clinical presentation and limitations in the commonly used detection methods. Knowledge of the role of mosaicism is limited in many skeletal disorders, including osteopathia striata with cranial sclerosis (OSCS) and cleidocranial dysplasia (CCD). We used whole-genome sequencing (WGS) with coverage >40× to identify the genetic causes of disease in two clinically diagnosed patients. In a female patient with OSCS, we identified a mosaic 7-nucleotide frameshift deletion in exon 2 of AMER1, NM_152424.4:c.855_861del:p.(His285Glnfs*7), affecting 8.3% of the WGS reads. In a male patient with CCD, approximately 34% of the WGS reads harbored a 3710-basepair mosaic deletion, NC_000006.11:g.45514471_45518181del, starting in intron 8 of RUNX2 and terminating in the 3' untranslated region. Droplet digital polymerase chain reaction was used to validate these deletions and quantify the absolute level of mosaicism in each patient. Although constitutional variants in AMER1 and RUNX2 are a known cause of OSCS and CCD, respectively, the mosaic changes here reported have not been described previously. Our study indicates that mosaicism should be considered in unsolved cases of skeletal dysplasia and should be investigated with comprehensive and sensitive detection methods. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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BACKGROUND: Root resorption (RR) of the adjacent teeth due to upper canine impaction requires an appropriate modification of the orthodontic treatment plan and the mechanotherapy used. AIM: The aim of this review was to assess scientific evidence published during the last decade, concerning the prevalence of lateral incisor RR caused by impacted maxillary canines, based only on cone-beam computed tomography (CBCT). The location of RR on this tooth, as well as the prevalence of RR on the other adjacent teeth, were additionally evaluated. METHODS: This review followed the criteria specified by the PRISMA statement. Four databases were searched for articles published between January 2008 and June 2021. Predefined and piloted data collection forms were used to record the necessary information. RESULTS: A total of 5098 records were initially screened. Only seven articles were finally eligible for further analysis. A total number of 540 participants (176 males and 364 females) was derived from the included studies. RR of maxillary lateral incisors was common (50%). RR of mild severity was more common (62%), more frequently located in the middle (52%) and apical (42%) thirds of the root. CONCLUSIONS: Further research with more homogeneous groups is required.
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Background: It was the aim of this study to investigate tooth agenesis patterns, which are expressed to different subphenotypes according to the TAC method in a spectrum of non-syndromic orofacial cleft patients. Methods: A total of 183 orofacial cleft patient records were assessed for tooth agenesis and TAC patterns. The association between TAC and sex, and cleft type was examined, and logistic regression models were additionally applied. Additionally, the distribution of missing teeth by cleft type and the tooth agenesis inter-quadrant association were examined. Results: The most frequent cleft type was CLPL (n = 72; 39.3%), while the maxillary left lateral incisor was the most frequently missing tooth that was strongly dependent on the cleft type (29.5%, p < 0.001). Of the 31 TAC patterns identified, four were the most prevalent and occurred in 80.8% of the sample, while 20 TAC patterns were unique. Cleft type contrary to sex (p = 0.405) was found to play a significant role in TAC distribution (p = 0.001). The logistic regression's results suggested that overall, neither sex nor cleft type were associated with tooth agenesis. Prevalence of tooth agenesis in each quadrant clearly depended on cleft type; and there was a strong association found between tooth agenesis in different quadrants. Conclusions: Thirty-one different subphenotypes were identified in TAC patterns. The first four TAC patterns accounted for the 80.8% of the sample's variability while twenty of the patterns were unique. A strong association was present between TAC pattern and cleft type. No association was found between the sex of the patient, tooth agenesis and TAC patterns. Tooth agenesis depended strongly on the cleft type, and the most frequently missing tooth was the maxillary left lateral incisor. The interquadrant association for tooth agenesis found suggests a genetic link in the etiology of clefts.
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BACKGROUND: Facioscapulohumeral muscular dystrophy is the third most commonly found type of muscular dystrophy. The aim of this study was to correlate the D4Z4 repeat array fragment size to the orofacial muscle weakening exhibited in a group of patients with a genetically supported diagnosis of FSHD. METHODS: Molecular genetic analysis was performed for 52 patients (27 female and 25 male) from a group that consisted of 36 patients with autosomal dominant pedigrees and 16 patients with either sporadic or unknown family status. The patients were tested with the southern blotting technique, using EcoRI/Avrll double digestion, and fragments were detected by a p13E-11 telomeric probe. Spearman's correlation was used to compare the fragment size with the degree of muscle weakening found in the forehead, periocular and perioral muscles. RESULTS: A positive non-significant correlation between the DNA fragment size and severity of muscle weakness was found for the forehead (r = 0.27; p = 0187), the periocular (r = 0.24; p = 0.232) and the left and right perioral (r = 0.29; p = 0.122), (r = 0.32; p = 0.085) muscles. CONCLUSIONS: Although FSHD patients exhibited a decrease in muscular activity related to the forehead, perioral, and periocular muscles the genotype-phenotype associations confirmed a weak to moderate non-significant correlation between repeat size and the severity of muscle weakness. Orofacial muscle weakening and its association with a D4Z4 contraction alone may not have the significance to serve as a prognostic biomarker, due to the weak to moderate association. Further studies with larger sample sizes are needed to determine the degree of genetic involvement in the facial growth in FSHD patients.
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Dentin dysplasia is a rare hereditary disorder, transmitted by autosomal dominant mode, affecting both dentin and pulp. In Type I crown morphology is normal, but root dentin organization loss leads to shorter roots. Mutations in the SSUH2, VPS4B and SMOC2 genes have been reported as responsible for this condition. Orthodontic treatment was conducted on an 11-year-old female patient presenting the disorder along with bilaterally impacted permanent maxillary canines, in close proximity to the roots of the lateral and central incisors. Treatment plan included lateral incisors extraction, surgical exposure and traction of the impacted canines. Light forces were applied from a custom-made trans-palatal arch. Comprehensive orthodontic treatment was performed using edgewise appliances. After 3 years and 2 months, group function occlusion was achieved. The canines underwent composite resin restorations. At one year post-retention, the dentition remained stable. Family-based genetic analysis did not reveal any mutations in the aforementioned genes pointing to further genetic heterogeneity of this disorder. As dental medicine becomes more sophisticated and personalized, the association between mutation type/function and orthodontic treatment response may provide useful therapeutic insights. The positive treatment response of the presented case could be attributed to a more "benign" mutation awaiting to be identified.
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Saliva, an essential oral secretion involved in protecting the oral cavity's hard and soft tissues, is readily available and straightforward to collect. Recent studies have analyzed the salivary proteome in children and adolescents with extensive carious lesions to identify diagnostic and prognostic biomarkers. The current study aimed to investigate saliva's diagnostic ability through proteomics to detect the potential differential expression of proteins specific for the occurrence of carious lesions. For this study, we performed bioinformatics and functional analysis of proteomic datasets, previously examined by our group, from samples of adolescents with regulated and unregulated type 1 diabetes, as they compare with healthy controls. Among the differentially expressed proteins relevant to caries pathology, alpha-amylase 2B, beta-defensin 4A, BPI fold containing family B member 2, protein S100-A7, mucin 5B, statherin, salivary proline-rich protein 2, and interleukin 36 gamma were significantly downregulated in poorly-controlled patients compared to healthy subjects. In addition, significant biological pathways (defense response to the bacterium, beta-defensin activity, proline-rich protein activity, oxygen binding, calcium binding, and glycosylation) were deregulated in this comparison, highlighting specific molecular characteristics in the cariogenic process. This analysis contributes to a better understanding of the mechanisms involved in caries vulnerability in adolescents with unregulated diabetes.
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Saliva is identified as functional equivalent to serum, reflecting the physiological state of the body, as well as hormonal, emotional, nutritional and metabolic alterations. The application of mass spectrometry based approaches has allowed a thorough characterization of the saliva proteome and led to the discovery of putative biomarkers. Several salivary biomarkers have been recently explored as potentially useful screening tools in patients diagnosed with metabolic disorders. In this review, we provide an overview of saliva proteomics studies, with a focus on diabetes, and we explore the evidence for the utility of well identified markers for the diagnosis and monitoring of the disease. Emerging approaches in salivary diagnostics that may significantly advance the field of diabetes research are also highlighted.
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Proteoma/análise , Proteômica/métodos , Saliva/química , Biomarcadores/análise , Biomarcadores/metabolismo , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/metabolismo , Humanos , Proteoma/metabolismo , Saliva/metabolismoRESUMO
OBJECTIVES: The aim of this cross-sectional study was to investigate how the level of metabolic control affects salivary function, xerostomia prevalence and incidence of caries, in children and adolescents with type 1 diabetes. METHODS: For the purpose of this study, a total of 150 children and adolescents (10-18 years old) were examined and allocated among 3 groups: 50 patients poorly-controlled (HbA1c≥7.5%), 50 well-controlled (HbA1c<7.5%) and 50 age- and sex-matched healthy controls. All subjects were examined for dental caries, oral hygiene and salivary factors. Assessments of salivary characteristics included self-reported xerostomia, quantification of resting and stimulated whole saliva flow rates, pH values, buffering capacity and saliva's viscosity. A questionnaire and a chair-side saliva testing kit were used for the evaluation of salivary function. Caries incidence was recorded using DMFT index. Plaque index and gingival index were additionally evaluated. Data were analysed by Chi-square and Kruskal-Wallis tests. RESULTS: Higher caries levels, higher prevalence of xerostomia and a decreased unstimulated salivary flow rate were recorded in poorly-controlled diabetics. The average caries indexes were DMFT(poor c) 3.6, DMFT(well c)1.2, DMFT(healthy) 1.5, p < 0.05). Salivary status and caries index were not found to be significantly different between well-controlled patients and healthy controls. CONCLUSIONS: The results of this study indicated that chair-side salivary tests provide the practitioners with an easy-to use and quick method for the evaluation of salivary function and caries risk assessment in young patients with diabetes. CLINICAL SIGNIFICANCE: The use of chair-side salivary tests provide the practitioners with an easy-to use and quick method for caries risk assessment and confirmation of clinical symptoms and signs in young patients with diabetes. They could be easily incorporated into daily office routine and may provide a useful tool for screening at risk patients and a simple way to communicate with the patients the need for further interventions for prevention.
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Cárie Dentária/diagnóstico , Diabetes Mellitus Tipo 1 , Saliva/metabolismo , Xerostomia/diagnóstico , Adolescente , Criança , Estudos Transversais , Índice CPO , Cárie Dentária/epidemiologia , Humanos , Medição de RiscoRESUMO
In vulnerable populations, such as infants and children, saliva makes the perfect diagnostic medium because of its noninvasive collection, easy handling and storage of samples. Its unique biomarker profiles help tremendously in the diagnosis of many diseases and conditions. In fact, saliva genomics, proteomics, transcriptomics, metabolomics and microbiome-based discoveries have led to complementary and powerful diagnostic information. In children and neonates, saliva is the preferred medium not only for diagnosis of caries and aggressive periodontitis but also for a number of systemic conditions, metabolic diseases, cognitive functions, stress assessment and evaluation of immunological and inflammatory responses to vaccination. In this review, we provide an overview of current and future applications of saliva diagnostics to various diseases and conditions and highlight studies in paediatrics across the "omic" spectrum. Emerging frontiers in salivary diagnostics research that may significantly advance the field are also highlighted.
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Pediatria , Saliva/química , Biomarcadores , Criança , Genômica , Humanos , Recém-Nascido , Metabolômica , Microbiota , Proteômica , TranscriptomaRESUMO
The case of an 18-year-old woman with generalized short root anomaly (SRA) is presented, and the clinical management and challenges associated with this rare condition are discussed. The patient was referred for restoration of the edentulous maxillary left anterior region. Due to the SRA, the patient had previously received limited orthodontic treatment for the ectopic maxillary canines. The maxillary left canine failed during orthodontic traction, the left lateral incisor migrated in its region and had poor prognosis due to severe mobility. Therefore, it was extracted and the region was restored with an implant-supported cantilever metal-ceramic fixed partial denture. Radiographic examination revealed generalized SRA along with other dental anomalies. From the patient's family history, as well as from the physical, clinical, radiographic, biochemical, and histologic evaluations, we were unable to identify the etiology behind this unique combination of dental anomalies. Esthetics and function were successfully restored and a strict recall system was implemented in order to monitor and maintain the short-rooted teeth. The need to prevent tooth and periodontal tissue deterioration in patients with generalized short roots is emphasized.
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Prótese Dentária Fixada por Implante , Prótese Parcial Fixa , Arcada Parcialmente Edêntula/reabilitação , Raiz Dentária/anormalidades , Adolescente , Feminino , Humanos , Maxila , Anormalidades Dentárias/diagnóstico por imagem , Anormalidades Dentárias/reabilitação , Técnicas de Movimentação Dentária/instrumentaçãoRESUMO
The composition of the salivary proteome is affected by pathological conditions. We analyzed by high resolution mass spectrometry approaches saliva samples collected from children and adolescents with type 1 diabetes and healthy controls. The list of more than 2000 high confidence protein identifications constitutes a comprehensive characterization of the salivary proteome. Patients with good glycemic regulation and healthy individuals have comparable proteomic profiles. In contrast, a significant number of differentially expressed proteins were identified in the saliva of patients with poor glycemic regulation compared to patients with good glycemic control and healthy children. These proteins are involved in biological processes relevant to diabetic pathology such as endothelial damage and inflammation. Moreover, a putative preventive therapeutic approach was identified based on bioinformatic analysis of the deregulated salivary proteins. Thus, thorough characterization of saliva proteins in diabetic pediatric patients established a connection between molecular changes and disease pathology. This proteomic and bioinformatic approach highlights the potential of salivary diagnostics in diabetes pathology and opens the way for preventive treatment of the disease.
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PURPOSE: The present study aimed to investigate the long-term effects of hydrostatic pressure on chondrocyte differentiation, as indicated by protein levels of transcription factors SOX9 and RUNX2, on transcriptional activity of SOX9, as determined by pSOX9 levels, and on the expression of polycystin-encoding genes Pkd1 and Pkd2. MATERIALS AND METHODS: ATDC5 cells were cultured in insulin-supplemented differentiation medium (ITS) and/or exposed to 14.7 kPa of hydrostatic pressure for 12, 24, 48, and 96 h. Cell extracts were assessed for SOX9, pSOX9, and RUNX2 using western immunoblotting. The Pkd1 and Pkd2 mRNA levels were detected by real-time PCR. RESULTS: Hydrostatic pressure resulted in an early drop in SOX9 and pSOX9 protein levels at 12 h followed by an increase from 24 h onwards. A reverse pattern was followed by RUNX2, which reached peak levels at 24 h of hydrostatic pressure-treated chondrocytes in ITS culture. Pkd1 and Pkd2 mRNA levels increased at 24 h of combined hydrostatic pressure and ITS treatment, with the latter remaining elevated up to 96 h. CONCLUSIONS: Our data indicate that long periods of continuous hydrostatic pressure stimulate chondrocyte differentiation through a series of molecular events involving SOX9, RUNX2, and polycystins-1, 2, providing a theoretical background for functional orthopedic mechanotherapies.
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Diferenciação Celular/fisiologia , Condrócitos/citologia , Condrócitos/fisiologia , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Mecanotransdução Celular/fisiologia , Fatores de Transcrição SOX9/metabolismo , Animais , Linhagem Celular , Condrogênese/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Pressão Hidrostática , Camundongos , Estresse MecânicoRESUMO
Normal extension and skull expansion is a synchronized process that prevails along the osteogenic intersections of the cranial sutures. Cranial sutures operate as bone growth sites allowing swift bone generation at the edges of the bone fronts while they remain patent. Premature fusion of one or more cranial sutures can trigger craniosynostosis, a birth defect characterized by dramatic manifestations in appearance and functional impairment. Up until today, surgical correction is the only restorative measure for craniosynostosis associated with considerable mortality. Clinical studies have identified several genes implicated in the pathogenesis of craniosynostosis syndromes with useful insights into the underlying molecular signaling events that determine suture fate. In this review, we exploit the intracellular signal transduction pathways implicated in suture pathobiology, in an attempt to identify key signaling molecules for therapeutic targeting.
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It has been demonstrated that APOBEC3B possesses cytidine deaminase activity, which is likely to result in C-to-T signature mutations. Increased expression of the APOBEC3B gene has been shown to correlate with higher incidence of such mutations in various cancer types, such as breast, bladder, lung, and head and neck carcinomas. In the current study, we used in silico methods, immunohistochemistry and qRT-PCR to detect the presence of APOBEC3B signature mutations and examine the levels and patterns of APOBEC3B expression in oral squamous cell carcinomas (OSCCs). Using the Cancer Genome Atlas (TCGA) database, we have found a high incidence of C-to-T transitions in head and neck squamous cell carcinomas (HNSCCs), of which OSCCs constitute the largest subgroup. Additionally, we compared APOBEC3B expression, at both mRNA and protein level, between OSCCs and non-cancerous samples. APOBEC3B was detected in both groups, but nuclear localization was consistent only in normal oral cells. APOBEC3B mRNA levels were clearly higher in OSCCs than in controls. These results suggest that while in normal oral cells APOBEC3B has an important nuclear function to fulfill, this activity may be hindered in a subgroup of tumor cells, due to the more prominent localization of the enzyme in the cytoplasm.