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1.
Zhonghua Bing Li Xue Za Zhi ; 53(2): 143-148, 2024 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-38281781

RESUMO

Objective: To investigate the clinicopathological characteristics of SMARCA4-deficient thoracic undifferentiated tumors, and the diagnostic value of the cells in serous effusion. Methods: Eleven cases of SMARCA4-deficient tumor were collected from the Affiliated Hospital of Hebei University, China from January 2018 to July 2023, which were diagnosed using cell block of serous effusion. The clinical, histopathological, immunohistochemical and molecular genetic features were reviewed, along with related literature. Results: All the 11 patients were males with ages ranging from 54 to 77 years (median 64 years). Nine patients were smokers and two had an unknown smoking history. Most of them complained of cough and dyspnea with pleural effusion. The primary tumor sites included lung (9 cases), thoracic wall (1 case), and mediastinum (1 case), while 3 patients had a history of lung surgery. Histologically, tumor cells were large and pleomorphic, with increased nuclear-cytoplasmic ratio. They also showed round nuclei, conspicuous nucleoli, and basophilic cytoplasm in serous effusion. Immunohistochemically, tumor cells in all cases were negative for SMARCA4/BRG1, CKpan and CK7, but positive for SMARCB1/INI1. Some of the cases were positive for CD34 (7/11), synaptophysin (4/11) and SALL4 (2/11). Histologically, monotonous tumor cells formed solid sheets or anastomosing islands with poor cell adhesion and rhabdoid morphology. Brisk mitotic figures were accompanied by large areas of necrosis. Some cases focally exhibited syncytia, and some had bright cytoplasm and vesicular chromatin. The immunohistochemical profiles in the tumor tissues were consistent with those of cytology. Six cases were negative for PD-L1 (22c3). Among the 6 cases analyzed by targeted next generation sequencing, concurrent SMARCA4 and TP53 mutations were detected in all 6 cases. Some of the 6 tumors showed mutations of STK11, CDKN2A, and MET, and amplification of ERBB2, exon deletion of BRCA2, etc. Follow-up information was available in all cases and ranged from 2 to 24 months. The patients showed metastases to various sites, including lymph node, liver, kidney, adrenal gland, brain, bone and other sites. Four patients died of the tumor. The survival time of 4 patients who underwent radical resection or radiofrequency ablation was more than 13 months. Conclusions: SMARCA4-deficient thoracic sarcoma is a rare but highly aggressive tumor with dismal prognosis and rhabdomyoid features. It is difficult to diagnose this disease using only serous effusion samples. This tumor thus warrants careful consideration. Accurate diagnosis can greatly improve early diagnosis and treatment of these tumors.


Assuntos
Neoplasias Torácicas , Humanos , Masculino , Biomarcadores Tumorais/genética , Núcleo Celular/metabolismo , DNA Helicases/genética , Mutação , Proteínas Nucleares/genética , Prognóstico , Fatores de Transcrição/genética , Pessoa de Meia-Idade , Idoso , Neoplasias Torácicas/patologia
2.
Zhonghua Jie He He Hu Xi Za Zhi ; 43(5): 427-430, 2020 May 12.
Artigo em Chinês | MEDLINE | ID: mdl-32087623

RESUMO

Objective: To raise awareness about 2019 novel coronavirus pneumonia (NCP) and reduce missed diagnosis rate and misdiagnosis rate by comparing the clinical characteristics between RNA positive and negative patients clinically diagnosed with NCP. Methods: From January 2020 to February 2020, 54 patients who were newly diagnosed with NCP in Wuhan Fourth Hospital were included in this study. RT-PCR method was used to measure the level of 2019-nCov RNA in pharyngeal swab samples of these patients. The patients were divided into RNA positive and negative group, and the differences of clinical, laboratory, and radiological characteristics were compared. Results: There were 31 RNA of 2019-nCov positive cases, and 23 negative cases. Common clinical symptoms of two groups were fever (80.64% vs. 86.96%) , chills (61.29% vs. 52.17%) , cough (80.64% vs. 95.65%) , fatigue (61.30% vs. 56.52%) , chest distress (77.42% vs.73.91%) . Some other symptoms were headache, myalgia, dyspnea, diarrhea, nausea and vomiting. The laboratory and radiological characteristics of two groups mainly were lymphopenia, increased erythrocyte sedimentation rate, increased C-reactive protein, increased lactate dehydrogenase, decreased oxygenation index, normal white blood cell count and bilateral chest CT involvement. There was no statistically significant difference in other clinical characteristics except for dyspnea between two groups. Conclusions: RNA positive and negative NCP patients shared similar clinical symptoms, while RNA positive NCP patients tended to have dyspnea. Therefore, we should improve the understanding of NCP to prevent missed diagnosis and misdiagnosis; In addition, more rapid and accurate NCP diagnostic approaches should be further developed.


Assuntos
Infecções por Coronavirus , Pandemias , Pneumonia Viral , RNA Viral , Betacoronavirus/isolamento & purificação , COVID-19 , Teste para COVID-19 , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/patologia , Erros de Diagnóstico/estatística & dados numéricos , Humanos , Diagnóstico Ausente/estatística & dados numéricos , Pneumonia Viral/diagnóstico , Pneumonia Viral/patologia , RNA Viral/análise , SARS-CoV-2
3.
Ecotoxicology ; 24(7-8): 1754-64, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25956985

RESUMO

Heavy metal residues and chemical contaminators considered as relevant sources of aquatic environmental pollutants have a generally immunosuppressive effect on aquatic organisms, depressing metabolic activities and immune response. Glutamine: fructose-6-phosphate aminotransferase (GFAT, EC2.6.1.16) is the first, and rate-limiting, enzyme in the hexosamine biosynthetic pathway, and is involved in the regulation of chitin biosynthesis and glycosylation of proteins. We have isolated and characterized GFAT from the white shrimp Litopenaeus vannamei. Amino acid sequence similarity of the Lv-GFAT (L.vannamei-GFAT) was highest to GFATs isolated from insects and mammals (83 % similarity to that of Haemaphysalis longicornis). The open-reading frame of the Lv-GFAT codes for a protein of 41.6 kDa with a calculated isoelectric point of 5.03. RT-PCR assays showed that endogenous Lv-GFAT mRNA is most strongly expressed in the intestine. Further analysis of Lv-GFAT gene expression in hepatopancreas by quantitative real-time PCR demonstrated that Lv-GFAT transcript levels increased when the shrimp were exposed to alkaline pH (9.3) and cadmium stress, but the time when its mRNA expression level peaked differed under these stresses. We also first expressed the recombinant protein of GFAT from shrimps in Escherichia coli. Western blot analyses confirmed that the Lv-GFAT protein was strongly expressed in the hepatopancreas after exposure to the LC-Cd stress. These results suggest that Lv-GFAT expression is stimulated by alkaline pH and cadmium stress and that it may play important roles in resistance of shrimp to environmental stresses.


Assuntos
Regulação Enzimológica da Expressão Gênica , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/genética , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/metabolismo , Penaeidae/enzimologia , Penaeidae/genética , Estresse Fisiológico , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Sequência de Bases , Cádmio/toxicidade , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Fases de Leitura Aberta , Penaeidae/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Poluentes Químicos da Água/toxicidade
4.
Genet Mol Res ; 14(2): 6202-12, 2015 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-26125821

RESUMO

We observed the effect of hydrogen-rich medium on lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVECs), hyaline leukocyte conglutination, and permeability of the endothelium. Endotheliocytes were inoculated on 6-well plates and randomly divided into 4 groups: control, H2, LPS, LPS+H2, H2, and LPS+H2 in saturated hydrogen-rich medium. We applied Wright's stain-ing to observe conglutination of hyaline leukocytes and HUVECs, flow cytometry to determine the content of vascular cell adhesion protein 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1), enzyme-linked immunosorbent assay to measure the E-selectin concentration in the cell liquor, the transendothelial electrical resistance (TEER) to test the permeability of endothelial cells, and Western blot and immunofluorescence to test the expression and distribution of vascular endothelial (VE)-cadherin. Compared with control cells, there was an increase in endothelium-hyaline leukocyte conglutination, a reduction in VCAM-1, ICAM-1, and E-selectin, and the TEER value increased obviously. Compared with LPS, there was an obvious reduction in the conglutination of LPS+H2 cells, a reduction in VCAM-1, ICAM-1, and E-selectin levels, and a reduction in the TEER-resistance value, while the expression of VE-cadherin increased. Fluorescence results showed that, compared with control cells, the VE-cadherin in LPS cells was in-complete at the cell joints. Compared with LPS cells, the VE-cadherin in LPS+H2 cells was even and complete at the cell joints. Liquid rich in hydrogen could reduce LPS-induced production of adhesion molecules and endothelium-hyaline leukocyte conglutination, and influence the expression and distribution of VE-cadherin to regulate the permeability of the endothelium.


Assuntos
Caderinas/metabolismo , Permeabilidade Capilar/efeitos dos fármacos , Hidrogênio/farmacocinética , Monócitos/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Meios de Cultura/química , Regulação da Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Lipopolissacarídeos/farmacologia , Monócitos/metabolismo
6.
Eur Rev Med Pharmacol Sci ; 28(4): 1464-1470, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38436180

RESUMO

OBJECTIVE: This study investigates the risk factors for complications following transurethral resection of the prostate and provides a reference for reducing postoperative complications. PATIENTS AND METHODS: A retrospective analysis was conducted on 322 patients with benign prostatic hyperplasia who underwent transurethral resection of the prostate from April 2015 to January 2022. Among them, 214 patients had complete clinical and follow-up data. Clinical and follow-up data were collected, and both univariate and multivariate logistic regression analyses were performed to identify factors influencing the occurrence of postoperation transurethral resection of the prostate complications. RESULTS: The incidence of complications after transurethral resection of the prostate was 19.16% (41/214). Among them, the incidence of Grade I-II complications was 14.96% (32/214), and Grade III-IV complications were 4.2% (9/214). The preoperative Quality of Life score (p<0.001) was identified as an independent risk factor for the occurrence of Grade I-II complications after transurethral resection of the prostate. The International Prostate Symptom Score (p=0.006) was identified as an independent risk factor for the occurrence of Grade III-IV complications after transurethral resection of the prostate. CONCLUSIONS: The preoperative Quality of Life score is an independent risk factor for the occurrence of Grade I-II complications after transurethral resection of the prostate. The International Prostate Symptom Score is an independent risk factor for the occurrence of Grade III-IV complications after transurethral resection of the prostate.


Assuntos
Próstata , Ressecção Transuretral da Próstata , Masculino , Humanos , Próstata/cirurgia , Ressecção Transuretral da Próstata/efeitos adversos , Qualidade de Vida , Estudos Retrospectivos , Fatores de Risco
7.
Eur Rev Med Pharmacol Sci ; 24(7): 3605-3613, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32329835

RESUMO

OBJECTIVE: Currently, the therapeutic effect on patients with liver cancer is associated with disease development. Meanwhile, the efficacy in patients with advanced liver cancer is far from satisfactory. Therefore, the aim of this study was to explore the association of disease condition with changes in liver function indexes, intestinal flora, and plasma endotoxin (ET) and vascular endothelial growth factor (VEGF) levels in patients with liver cancer. PATIENTS AND METHODS: A total of 300 patients with primary liver cancer in our hospital were enrolled in this study. All patients were divided into three groups, including early liver cancer group, middle liver cancer group, and advanced liver cancer group. Peripheral blood was collected from each subject to detect liver function indexes, procalcitonin (PCT), plasma ET, and VEGF levels. Furthermore, mid-posterior-segment stools were collected from 15 cases in each group, and sent to the company for detection of intestinal flora. RESULTS: Liver function indexes in peripheral blood of patients with liver cancer changed with the changes in disease condition. With the progression of liver cancer, the level of aspartate aminotransferase (AST) increased significantly, and the highest was observed in advanced liver cancer patients [(91.18±10.34) U/L] (p=0.046). However, the level of plasma total protein declined significantly, which was (24.83±1.75) g/L in advanced liver cancer patients (p=0.035). The changes in total bilirubin were significantly associated with the progression of liver cancer (p=0.003). The abundance of Clostridiales, Firmicutes, and Streptococcus in the intestinal tract was high in early liver cancer group. The abundance of Ruminococcaceae, Pasteurellaceae, Tanticharoenia, and Vagococcus in the intestinal tract was high in middle liver cancer group. Meanwhile, the abundance of Bifidobacteriales, Actinobacteria, Barnesiella, Porphyromonadaceae, and Pseudomonadales in the intestinal tract was high in advanced liver cancer group. In patients with liver cancer, the level of Enterobacteriaceae was positively correlated with that of Firmicutes (r=0.36, p=0.003), whereas it was negatively correlated with Lactobacillus (r=-0.72, p=0.021). The level of Lactobacillus was positively correlated with that of Ruminococcaceae (r=0.39, p=0.043), whereas it was negatively correlated with that of Firmicutes (r=-0.27, p=0.019). In addition, the level of PCT markedly rose in advanced liver cancer group [(6.89±0.35) ng/mL] (p=0.021). The level of ET increased significantly with the development of liver cancer, with the highest level observed in advanced liver cancer group [(0.71±0.09) EU/mL] (p=0.004). The level of VEGF also increased remarkably with the aggravation of liver cancer, and the highest was found in advanced liver cancer group [(112.33±2.11) µmol/L], showing differences among groups (p<0.05). CONCLUSIONS: With the progression of liver cancer, the abundance of Barnesiella, etc., rose and that of Ruminococcaceae, etc., declined in the intestinal tract. Meanwhile, the composition of intestinal flora was changed, and the levels of plasma ET and VEGF increased.


Assuntos
Endotoxinas/sangue , Microbioma Gastrointestinal , Neoplasias Hepáticas/sangue , Fatores de Crescimento do Endotélio Vascular/sangue , Endotoxinas/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Fatores de Crescimento do Endotélio Vascular/metabolismo
8.
Eur Rev Med Pharmacol Sci ; 24(20): 10359-10365, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33155267

RESUMO

OBJECTIVE: To investigate the heterogeneity of decidual endothelial cells and their changes during delivery. PATIENTS AND METHODS: Single-cell RNA sequencing was used to characterize the transcriptomes of decidual endothelial cells before and after the onset of labor. RESULTS: Decidual endothelial cells (9748 cells) were divided into five subgroups with different functions according to differences in the transcriptome. The functions of cluster 5 were enriched in vascular development and response to growth factors. After the onset of labor, the activities of each cluster were different, including the interleukin 17 pathway and regulation of ERK1 and ERK2 cascade. The downregulated genes were related to scavenger receptor (cluster 5), which may reflect the process of endothelial activation. In terms of genetic changes, cluster 5 may be more actively involved in labor than the other clusters. CONCLUSIONS: Peripartum decidual endothelial cells are heterogeneous and participate in labor to varying degrees. One of the five subtypes of endothelial cells may be more actively involved in labor onset. Our findings may enable the assessment of decidual endothelial cells and labor onset.


Assuntos
Decídua/citologia , Células Endoteliais/citologia , Início do Trabalho de Parto , Análise de Célula Única , Feminino , Humanos , Gravidez , Análise de Sequência de RNA , Transcriptoma
9.
Acta Physiol (Oxf) ; 222(3)2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28888077

RESUMO

AIM: Endothelial cell injury assumes a fundamental part in the pathogenesis of atherosclerosis, and endothelial cell autophagy has protective effects on the development of atherosclerosis, although the underlying molecular regulation mechanism is indistinct. This study aimed to investigate whether microRNA-214-3p (miR-214-3p) is involved in the endothelial cell autophagy regulation of atherosclerosis. METHODS: We utilized ApoE-/- mice provided with a high-fat diet (HFD) as atherosclerosis model. We analysed the level of miR-214-3p and the levels of autophagy-related protein 5 (ATG5) and autophagy-related protein 12 (ATG12) in the purified CD31+ endothelial cells from mouse aorta. Bioinformatics analysis and a dual-luciferase reporter assay were performed to confirm the binding target of miR-214-3p. In vitro study, human umbilical vein endothelial cells (HUVECs) were transfected with miR-214-3p mimics/inhibitor and stimulated with 100 µg/mL oxidized low-density lipoprotein (ox-LDL) for 12 hours to initiate a stress-repairing autophagic process. RESULTS: In mouse models, we identified an inverse correlation between miR-214-3p, ATG5 and ATG12. We observed that in young HUVECs, ox-LDL-initiated autophagy was repressed by miR-214-3p overexpression, as evaluated by autophagic protein analysis, microtubule-associated protein 1 light chain 3B-II (LC3B-II) immunofluorescence assay and transmission electron microscopy (TEM). Also, miR-214-3p promoted ox-LDL accumulation in HUVECs and THP-1 monocyte adhesion. Conversely, in old HUVECs, suppression of miR-214-3p preserved the ability to initiate a protective autophagy reaction to the ox-LDL stimulation. CONCLUSION: miR-214-3p regulates ox-LDL-initiated autophagy in HUVECs by directly targeting the 3'UTR of ATG5 and may have a suitable role in the pathogenesis of atherosclerosis.


Assuntos
Aterosclerose/metabolismo , Autofagia/fisiologia , Células Endoteliais/patologia , MicroRNAs/metabolismo , Animais , Autofagia/efeitos dos fármacos , Dieta Hiperlipídica , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Lipoproteínas LDL/farmacologia , Camundongos , Camundongos Knockout
10.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 52(6): 351-354, 2017 Jun 09.
Artigo em Chinês | MEDLINE | ID: mdl-28613056

RESUMO

Objective: To evaluate the processing accuracy, internal quality and suitability of the titanium alloy frameworks of removable partial denture (RPD) fabricated by selective laser melting (SLM) technique, and to provide reference for clinical application. Methods: The plaster model of one clinical patient was used as the working model, and was scanned and reconstructed into a digital working model. A RPD framework was designed on it. Then, eight corresponding RPD frameworks were fabricated using SLM technique. Three-dimensional (3D) optical scanner was used to scan and obtain the 3D data of the frameworks and the data was compared with the original computer aided design (CAD) model to evaluate their processing precision. The traditional casting pure titanium frameworks was used as the control group, and the internal quality was analyzed by X-ray examination. Finally, the fitness of the frameworks was examined on the plaster model. Results: The overall average deviation of the titanium alloy RPD framework fabricated by SLM technology was (0.089±0.076) mm, the root mean square error was 0.103 mm. No visible pores, cracks and other internal defects was detected in the frameworks. The framework fits on the plaster model completely, and its tissue surface fitted on the plaster model well. There was no obvious movement. Conclusions: The titanium alloy RPD framework fabricated by SLM technology is of good quality.


Assuntos
Ligas Dentárias/normas , Técnica de Fundição Odontológica , Planejamento de Dentadura , Prótese Parcial Removível/normas , Lasers , Titânio , Desenho Assistido por Computador , Humanos
11.
Eur Rev Med Pharmacol Sci ; 20(11): 2338-45, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27338059

RESUMO

OBJECTIVE: Surfactant protein B (SP-B) is the only essential protein component of lung surfactant, the relationship between localization and function is very close. The localization of rat SP-B and influences of lipopolysaccharide (LPS) on it were investigated. MATERIALS AND METHODS: The localization of SP-B protein in lung tissue was detected by immunofluorescence after challenged with intratracheal instillation of LPS. The constructed recombinant plasmid pEGFP-N2-SP-B was transfected with CCl-149 cell lines by liposome to explore the localization of SP-B in alveolar type II epithelial cells. Furthermore, the expression and function of SP-B were analyzed with LPS stimulating. RESULTS: The proteins SP-B and SP-C showed the same pattern of expression in normal lung, and distributed in the alveolar cavity, LPS can directly affect the expression of SP-B in vivo, contrast to SP-B, the LPS-induced influences on SP-C is little. SP-B had the membrane embedded features and localized on the cell surface of CCL149 in vitro, but was influenced by LPS. CONCLUSIONS: It is confirmed that the expression and membrane function of SP-B were decreased by stimulating LPS in lung tissue and alveolar type II epithelial cells.


Assuntos
Pulmão/metabolismo , Proteína B Associada a Surfactante Pulmonar , Surfactantes Pulmonares , Animais , Lipopolissacarídeos/farmacologia , RNA Mensageiro/metabolismo , Ratos
12.
Dev Comp Immunol ; 59: 77-88, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26801100

RESUMO

PTEN, a tumor suppressor gene, suppresses cell survival, growth, apoptosis, cell migration and DNA damage repair by inhibiting the PI3K/AKT signaling pathway. In this study, the full-length Litopenaeus vannamei PTEN (LvPTEN) cDNA was obtained, containing a 5'UTR of 59bp, an ORF of 1269bp and a 3'UTR of 146bp besides the poly (A) tail. The PTEN gene encoded a protein of 422 amino acids with an estimated molecular mass of 48.3 KDa and a predicted isoelectric point (pI) of 7.6. Subcellular localization analysis revealed that LvPTEN was distributed in both cytoplasm and nucleus, and the tissue distribution patterns showed that LvPTEN was ubiquitously expressed in all the examined tissues. Vibrio alginolyticus challenge induced upregulation of LvPTEN expression. Moreover, RNAi knock-down of LvPTEN in vivo significantly increased the expression of LvAKT mRNA, while reducing that of the downstream apoptosis genes LvP53 and LvCaspase3. LvPTEN knock-down also caused a sharp increase in cumulative mortality, bacterial numbers, and DNA damage in the hemolymph of L. vannamei following V. alginolyticus challenge, together with a sharp decrease in the total hemocyte count (THC). These results suggested that LvPTEN may participate in apoptosis via the PI3K/AKT signaling pathway in L. vannamei, and play an important role in shrimp innate immunity.


Assuntos
Imunidade Inata/imunologia , PTEN Fosfo-Hidrolase/genética , Penaeidae/imunologia , Vibrioses/imunologia , Vibrio alginolyticus/imunologia , Sequência de Aminoácidos , Animais , Apoptose/imunologia , Sequência de Bases , Caspase 3/biossíntese , Clonagem Molecular , Dano ao DNA/genética , DNA Complementar/genética , Hemócitos/imunologia , Hemolinfa/citologia , Hemolinfa/microbiologia , PTEN Fosfo-Hidrolase/imunologia , Penaeidae/genética , Penaeidae/microbiologia , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Proto-Oncogênicas c-akt/biossíntese , Interferência de RNA , RNA Interferente Pequeno/genética , Alinhamento de Sequência , Proteína Supressora de Tumor p53/biossíntese , Vibrioses/microbiologia
14.
Angle Orthod ; 61(1): 31-4, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1826416

RESUMO

White spot decalcifications and caries occurring adjacent to bonded orthodontic brackets have long been a concern to orthodontists. One procedure suggested to overcome this problem is fluoride treatment prior to bonding. The purpose of this study was to compare the tensile bond strength of orthodontic self-cured resin from Concise on teeth rinsed 4 minutes in 1.23% APF with untreated controls. Measurements were made on an Instron machine. Debonding interfaces were observed with a scanning electron microscope and energy dispersive x-ray spectrometry. Distributions were calculated. The tensile bond strengths of the fluoride-treated teeth and the untreated teeth were not significantly different. The debonding interfaces between resin and bracket base, within the resin itself, and between enamel and resin were similar in the two experimental groups. However, greater enamel detachment was seen within the fluoride pretreatment group. So while fluoride pretreatment does not significantly affect tensile bond strength, it may cause enamel detachment after debonding.


Assuntos
Resinas Acrílicas/química , Resinas Compostas/química , Colagem Dentária , Esmalte Dentário/efeitos dos fármacos , Fluoretos Tópicos/farmacologia , Aparelhos Ortodônticos , Condicionamento Ácido do Dente , Adolescente , Bis-Fenol A-Glicidil Metacrilato , Criança , Esmalte Dentário/ultraestrutura , Análise do Estresse Dentário , Microanálise por Sonda Eletrônica , Humanos , Propriedades de Superfície , Resistência à Tração
15.
Angle Orthod ; 63(3): 225-30, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8214792

RESUMO

The purpose of this study was to analyze the tensile bond strength and debonding failure mode in younger and older permanent teeth after etching for 15 and 60 seconds. Bond strength did not change significantly when etching time was increased from 15 to 60 seconds in younger or older permanent teeth. However, regardless of etching time, the bond strength of the older permanent teeth was greater than that of the younger teeth with statistically significant differences. Four types of debonding interface were found; bracket base-resin, within the resin, resin-enamel and enamel detachment. There were no statistically significant differences noted among younger and older permanent teeth with 15 or 60 second etching fracture mode incidence at debondings. Enamel detachment was found only at etching times of 60 seconds. To reduce enamel destruction and save chair time, 15 second etching on either younger or older permanent teeth is suggested.


Assuntos
Condicionamento Ácido do Dente , Envelhecimento/fisiologia , Colagem Dentária , Ácidos Fosfóricos/química , Dente/fisiologia , Adolescente , Idoso , Bis-Fenol A-Glicidil Metacrilato/química , Criança , Colagem Dentária/métodos , Esmalte Dentário/ultraestrutura , Análise do Estresse Dentário , Humanos , Teste de Materiais , Pessoa de Meia-Idade , Braquetes Ortodônticos , Estresse Mecânico , Resistência à Tração , Fatores de Tempo
16.
Angle Orthod ; 64(5): 377-82, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7802332

RESUMO

Prior to bonding, the enamel surface of the tooth is normally etched using a solution of 37%-50% phosphoric acid (H3PO4) for 60 seconds. The purpose of this study was to evaluate the tensile bond strength, debonding interface distribution and enamel surface detachment of various concentrations of H3PO4 solution, from 2% to 80%, applied for 15 seconds. Statistically significant differences in bond strength were found among the various concentrations tested: concentrations in the 10% to 60% range produced greater bond strengths than both the weaker and stronger concentrations. The weaker the bond strength, the greater the debonding interface between resin and enamel. The greater the bond strength, the greater the debonding interface between the bracket and resin. Enamel detachment occurred as the H3PO4 concentration rose above 30%. To obtain greater bond strength and less enamel detachment, 10%-30% concentrations of phosphoric acid for 15 seconds etching are suggested for clinical bonding.


Assuntos
Condicionamento Ácido do Dente/métodos , Ácidos Fosfóricos/química , Adolescente , Análise de Variância , Bis-Fenol A-Glicidil Metacrilato/química , Criança , Descolagem Dentária , Esmalte Dentário/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Teste de Materiais , Braquetes Ortodônticos , Ácidos Fosfóricos/efeitos adversos , Propriedades de Superfície/efeitos dos fármacos , Resistência à Tração
17.
Angle Orthod ; 65(3): 209-14, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7639434

RESUMO

The absorption and desorption of water by a polymer matrix of composite orthodontic resin could cause debonding of the filler-matrix or hydrolytic degradation of fillers and loss of bond strength. In this study, the bond strength of brackets directly bonded with orthodontic composite to the enamel surface of premolars was measured with an Instron machine; the debonding interface distribution was analyzed by scanning electron microscope and energy dispersive x-ray spectrometry following water immersion for 1, 2, and 3 days, and 1, 2, 4, 8, 16, 24, and 32 weeks, respectively. The results show that, under water immersion, bond strength may gradually weaken over time. The greatest loss occurs initially, followed by a period of relative stabilization, and then a weaker reduction after 24 weeks. The greater the time in water immersion, the less the bond strength and the greater the destruction of the composite resin. The debonding interface occurs between bracket and resin.


Assuntos
Bis-Fenol A-Glicidil Metacrilato/química , Colagem Dentária , Cimentos Dentários/química , Braquetes Ortodônticos , Absorção , Adolescente , Análise de Variância , Dente Pré-Molar , Criança , Microanálise por Sonda Eletrônica , Humanos , Imersão , Teste de Materiais , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo , Água
18.
Ann R Coll Surg Engl ; 94(6): 395-401, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22943328

RESUMO

INTRODUCTION: The negative appendicectomy rate (NAR) is a quality metric in the management of appendicitis. While computed tomography (CT) has been associated with a low NAR, Alvarado scoring produces an acceptable NAR. The definition of negative appendicectomy may affect the NAR. This study examined the impact of CT, Alvarado score and definition on the NAR. METHODS: The charts of 1,306 emergency appendicectomy patients from 1996 to 2010 were reviewed. Three five-year cohorts were created (Cohort A: 1996-2000, Cohort B: 2001-2005, Cohort C: 2006-2010) and the NAR was calculated for each cohort using two definitions of negative appendicectomy: absence of inflammation (NAR-STD) and absence of intramural neutrophils (NAR-STR). NAR-STD was correlated to the CT rate for Cohorts B and C and also to Alvarado score for Cohort C. RESULTS: When the definition of negative appendicectomy was changed, the NAR rose from 9.2% to 15.8% (p=0.0097) for Cohort A, from 2.8% to 8.6% (p=0.0180) for Cohort B (CT rate: 80.6%) and from 3.0% to 6.7% (p=0.0255) for Cohort C (CT rate: 92.4%). The introduction of CT lowered NAR-STD from 1996-2000 (9.2%) to 2001-2010 (2.9%) but increasing the CT rate from 2001-2010 had no impact on the NAR. The positive predictive value for Alvarado score (98.60%) and CT (99.03%) were similar. CONCLUSIONS: The definition of a negative appendicectomy determines the NAR. CT reduces the NAR regardless of definition but routine CT is unnecessary for male patients with positive Alvarado scores. Early/mild appendicitis may resolve without surgery and CT may contribute to unnecessary surgery. Alvarado scoring allows selective use of CT in suspected appendicitis.


Assuntos
Apendicectomia/estatística & dados numéricos , Apendicite/cirurgia , Adolescente , Adulto , Idoso , Apendicectomia/normas , Apendicite/diagnóstico por imagem , Criança , Pré-Escolar , Estudos de Coortes , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Qualidade da Assistência à Saúde , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Adulto Jovem
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