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1.
Artigo em Inglês | MEDLINE | ID: mdl-31799699

RESUMO

Telomeres are specialized genomic structures that protect chromosomal ends to maintain genomic stability. Telomeric length is primarily regulated by the telomerase complex, essentially consisting of an RNA template (TERC), an enzymatic subunit (telomerase reverse transcriptase, TERT). In humans, telomerase activity is repressed during embryonic differentiation and is absent in most somatic cells. However, it is upregulated or reactivated in 80%-90% of the primary tumours in humans. The human TERT (hTERT) plays a pivotal role in cellular immortality and tumourigenesis. However, the molecular mechanisms of telomerase functioning in cancer have not been fully understood beyond the telomere maintenance. Several research groups, including ours, have demonstrated that hTERT possesses vital functions independent of its telomere maintenance, including angiogenesis, inflammation, cancer cell stemness, and epithelial-mesenchymal transformation (EMT). All these telomere-independent activities of hTERT may contribute to the regulation of the dynamics and homeostasis of the tumour microenvironment (TME), thereby promoting tumour growth and development. Cancer progression and metastasis largely depend upon the interactions between cancer cells and their microenvironment. In this review, the involvement of TERT in the tumour microenvironment and the underlying implications in cancer therapeutics have been summarized.

2.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 47(3): 382-8, 2016 May.
Artigo em Chinês | MEDLINE | ID: mdl-27468485

RESUMO

OBJECTIVE: To develop a questionnaire measuring sexual mental health of Tibetan university students. METHODS: A draft questionnaire was developed with reference to the Sexual Civilization Survey for University Students of New Century and other published literature, and in consultation with experts. The questionnaire was tested in 230 students. Exploratory factor analyses with principal component and varimax orthogonal rotation were performed. Common factors with a > 1 eigenvalues and ≥ 3 loaded items (factor loading ≥ 0.4) were retained. Items with a < 0.4 factor loading, < 0.2 commonality, or falling into a common factor with < 3 items were excluded. The revised questionnaire was administered in another sample of 481 university students. Cronbach's α and split-half reliabilities were estimated. Confirmatory factor analyses were performed to test the construct validity of the questionnaire. RESULTS: Four rounds of exploratory factor analyses reduced the draft questionnaire items from 39 to 34 with a 7-factor structure. The questionnaire had a Cronbach's α of 0.920, 0.898, 0.812, 0.844, 0.787, 0.684, 0.703, and 0.608, and a Spearman-Brown coefficient of 0.763, 0.867, 0.742, 0838, 0.746, 0.822, 0.677, and 0.564 for the overall questionnaire and its 7 domains, respectively, suggesting good internal reliability. The structural equation of confirmatory factor analysis fitted well with the raw data: fit index χ²/df 3.736; root mean square residual (RMR) 0.081; root mean square error of approximation (RMSEA = 0.076; goodness of fit index (GFI) 0.805; adjusted goodness of fit index (AGFI) 0.770; normed fit index (NFI) = 0.774; relative fit index (RFI) 0.749; incremental fit index (IFI) 0.824; non-normed fit index (NNFI) = 0.803; comparative fit index (CFI) = 0.823; parsimony goodness of fit index (PGFI) = 0.684; parsimony normed fit index (PNFI) = 0.698; parsimony comparative fit index (PCFI) = 0.742, suggesting good construct validity of the questionnaire. CONCLUSION: The Sexual Mental Health Questionnaire for Tibetan University Student has demonstrated good reliability and validity.


Assuntos
Saúde Mental , Inquéritos e Questionários , Análise Fatorial , Humanos , Reprodutibilidade dos Testes , Estudantes , Tibet , Universidades
3.
Shanghai Kou Qiang Yi Xue ; 22(4): 448-52, 2013 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-24100907

RESUMO

PURPOSE: The objective of present study was to assess the dimensional stability of the grafting material DBBM (Bio-oss) after maxillary sinus floor augmentation with spiral computed tomography (SCT) scans and 3D reconstruction. METHODS: Two postoperative SCT scans were available from 12 patients who had undergone maxillary sinus lift procedures. CT scan was taken at 2 week after surgical intervention and 6 months later, respectively. A total of 12 maxillary sinuses were augmented with 100% DBBM before implant insertion by lateral antrostomy in a staged approach. The augmentation volume was calculated using the SurgiCase CMF5.0 software. Data were calculated by Stata10 software package. RESULTS: The mean volume of the graft was reduced by 19.40%. Specifically, the reduction reached 0.29% in the buccal-palatal direction, 5.87% in the mesial-distal dimension, and 14.32% in vertical dimension. CONCLUSIONS: This study confirmed that the volume of DBBM has a certain amount of reduction within 6 months after sinus floor augmentation. The reduction in vertical direction is most severe.


Assuntos
Seio Maxilar , Levantamento do Assoalho do Seio Maxilar , Humanos , Minerais , Tomografia Computadorizada por Raios X
4.
J Plast Reconstr Aesthet Surg ; 66(3): 364-71, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23122692

RESUMO

BACKGROUND: This retrospective study aims to report an algorithm to assist surgeons in selecting different modes of the double-barrel vascularised fibula graft for mandibular reconstruction. METHODS: A total of 45 patients who underwent reconstruction of mandibular defects with different modes of the double-barrel vascularised fibula graft were reviewed. Our algorithm for deciding on any one of the different modes for different mandibular defects is influenced by factors including history of radiotherapy, the length of mandibular body defect and the need to preserve the inferior mandibular border. Post-operative functional outcomes included diet type and speech, and aesthetic results gained at post-operative 2 years. Patients with implant-borne prosthetic teeth underwent assessment of their masticatory function. RESULTS: There were four modes of mandibular reconstruction according to our algorithm, which included double-barrel vascularised fibula graft (n=21), partial double-barrel fibula graft (n=11), condylar prosthesis in combination with partial/double-barrel fibula graft (n=11), and double-barrel fibula onlay graft (n=2). Flap survival in all patients was 97.78%. Good occlusion, bony unions and wound closures were observed in 44 patients. Eleven patients received dental implantation in the transplanted fibula at post-operative 9-18th months. One patient wore removal partial dentures. For 11 patients with implant-borne prosthetic teeth, the average post-operative ipsilateral occlusal force was 41.5±17.7% of the contralateral force. Good functional and aesthetic results were achieved in 38 patients with more than 2 years of follow-up, including regular diet, normal speech and excellent or good appearance, especially for patients with dental rehabilitation. CONCLUSION: Good aesthetic and functional results can be achieved after dental rehabilitation by following our algorithm when choosing the different modes of double-barrel vascularised fibula graft for mandibular reconstruction.


Assuntos
Fíbula/irrigação sanguínea , Fíbula/transplante , Reconstrução Mandibular/métodos , Radiografia Panorâmica/métodos , Retalhos Cirúrgicos/irrigação sanguínea , Adulto , Idoso , Algoritmos , Transplante Ósseo/métodos , Estudos de Coortes , Feminino , Seguimentos , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Imagem Tridimensional , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Neoplasias Mandibulares/diagnóstico por imagem , Neoplasias Mandibulares/patologia , Neoplasias Mandibulares/cirurgia , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/métodos , Estudos Retrospectivos , Medição de Risco , Fatores de Tempo , Adulto Jovem
5.
Shanghai Kou Qiang Yi Xue ; 20(3): 265-8, 2011 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-21779734

RESUMO

PURPOSE: To compare the microstructure and ESR dosimetry between tetracycline-stained teeth and normal teeth by means of scanning electron microscopy (SEM) and electron spin resonance (ESR) dosimeter. METHODS: Ten first or second premolars of tetracycline-stained teeth and ten normal teeth extracted for adult orthodontic persons were collected. The enamel on the surface and the dentine on the cross section of both type of teeth were observed with SEM. The ESR signal of teeth components (enamel and dentine) was evaluated by X-band ESR spectroscopy. RESULTS: Compared with normal teeth, the enamel of tetracycline-stained teeth was of porosity and the enamel prisms were irregular. The dentinal tubules and dentinal matrix also showed obvious difference between the two type of teeth. The X-band ESR spectrum of tetracycline-stained teeth was different from normal teeth. CONCLUSION: The microstructure and the native radicals have significant effect on the tetracyclines deposited in the teeth.


Assuntos
Esmalte Dentário , Tetraciclina , Descoloração de Dente , Adulto , Dente Pré-Molar , Dentina , Humanos , Microscopia Eletrônica de Varredura , Dente
6.
Shanghai Kou Qiang Yi Xue ; 20(3): 308-13, 2011 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-21779744

RESUMO

PURPOSE: Using spiral computed tomography and Simplant software to measure the width and height of residual alveolar crest of agomphious upper molar region at different levels around bottom of low-set maxillary sinus. To evaluate the impact of sex, age, agomphious duration, and cause of tooth extraction on the width and height of residual alveolar crest. METHODS: Forty-three patients with missing uppers molar and residual alveolar bone height being 4 to 6mm showed by panoramic radiographs were scanned by spiral computed tomography. 3D model of the alveolar crest and maxillary sinus were reconstructed using the images from CT scan and Simplant software. The height and width of the residual alveolar crest of agomphious upper molar region at different levels around bottom of maxillary sinus were measured. The data was analyzed with SPSS16.0 software package for Student's t test, analysis of variance(ANOVA) and Kruskal-Wallis H test. RESULTS: (1)The mean distance between the top of residual alveolar crest and the floor of sinus was (5.26±0.58)mm. (2)The difference between the width of internal bone wall and that of external bone wall at different levels above the bottom of maxillary sinus was significant(P<0.01), except for agomphious upper second molar at 3.75mm. (3)The height of residual crest and width of sinus floor decreased remarkably with age and agomphious duration(P<0.01) while the width of sinus lateral walls didn't change so much with them(P>0.05). (4)Height of residual crest of the tooth extracted due to periodontitis was obviously lower than that of the tooth extracted due to residual root(crown) or crown fracture(P<0.01). CONCLUSIONS: The height and width of residual crest change significantly with age, agomphious duration and causes of tooth extraction. However, the width of lateral walls above sinus floor do not change so much with those factors. The internal wall of maxillary sinus floor is wider than the external wall at agomphious molar. This anatomic feature may be taken into consideration during implantation. The site and direction of implant can be adjusted equally according to the age, agomphious duration and causes of tooth extraction, so that maxillary sinus augmentation can be avoided in part of patients with low-set maxillary sinus.


Assuntos
Seio Maxilar , Levantamento do Assoalho do Seio Maxilar , Processo Alveolar , Humanos , Dente Molar , Tomografia Computadorizada por Raios X , Extração Dentária
7.
Zhonghua Nan Ke Xue ; 14(10): 876-8, 2008 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-19157093

RESUMO

OBJECTIVE: To study the effects of growth factors on the survival and proliferation of human spermatogonial stem cells (SSCs) in vitro. METHODS: SSCs were treated with the growth factors SCF, LIF and bFGF added to the culture, each at the concentrations of 0, 5, 10 and 20 microg/L and repeated three times. The survival time and proliferation rate of the cells were determined every 8-12 hours and their morphological features observed with the light microscope and electron microscope. RESULTS: The survival time and proliferation rate of the SSCs were significantly increased in the treated groups as compared with the control (P < 0.05). CONCLUSION: The growth factors SCF, LIF and bFGF can promote the survival and proliferation of SSCs in vitro.


Assuntos
Proliferação de Células/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Espermatogônias/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Fator 2 de Crescimento de Fibroblastos/farmacologia , Humanos , Fator Inibidor de Leucemia/farmacologia , Masculino , Espermatogônias/citologia , Fator de Células-Tronco/farmacologia , Células-Tronco/citologia
8.
Shanghai Kou Qiang Yi Xue ; 16(4): 370-3, 2007 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-17924019

RESUMO

PURPOSE: To analyze the effect of different premolar extraction on the position of the mandibular third molar during orthodontic treatment. METHODS: Cephalometric radiographs were taken before and after 2 years of treatment in 28 female patients selected from Department of Orthodontic, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University. Treatment for 12 patients in group I included extraction of 4 second premolars,the other 16 patients in group II were treated with extraction of 4 first premolars. Modified sectional arch wire technique was used to redistribute the spaces.Change of the mandibular third molar position was valued by tracing. The data was analyzed using SAS6.12 software package for student's t test. RESULTS: The vertical change in the third molar position in group I and II was (4.58+/-1.85)mm and (0.21+/-1.11)mm (P<0.01), the horizontal change was (2.95+/-2.55)mm and (-0.03+/-1.74)mm (P<0.01), the mesio-angulation was decreased (-10.12+/-8.27) degrees and (-5.06+/-3.60) degrees (P<0.05),and the angle to the second molar decreased (-15.58+/-9.65) degrees and (-4.21+/-3.68) degrees (P<0.001), respectively. CONCLUSION: Second premolar extraction may increase the rates of movement of the third molar in horizontal and vertical direction and decrease the mesio-angulation and the angle to the second molar than first premolar extraction.


Assuntos
Dente Serotino , Erupção Dentária , Extração Dentária , Migração de Dente , Dente Pré-Molar , Feminino , Humanos , Ortodontia Corretiva
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