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BACKGROUND: Stroma AReactive Invasion Front Areas (SARIFA) is a novel prognostic histopathologic biomarker measured at the invasive front in haematoxylin & eosin (H&E) stained colon and gastric cancer resection specimens. The aim of the current study was to validate the prognostic relevance of SARIFA-status in colorectal cancer (CRC) patients and investigate its association with the luminal proportion of tumour (PoT). METHODS: We established the SARIFA-status in 164 CRC resection specimens. The relationship between SARIFA-status, clinicopathological characteristics, recurrence-free survival (RFS), cancer-specific survival (CSS), and PoT was investigated. RESULTS: SARIFA-status was positive in 22.6% of all CRCs. SARIFA-positivity was related to higher pT, pN, pTNM stage and high grade of differentiation. SARIFA-positivity was associated with shorter RFS independent of known prognostic factors analysing all CRCs (RFS: hazard ratio (HR) 2.6, p = 0.032, CSS: HR 2.4, p = 0.05) and shorter RFS and CSS analysing only rectal cancers. SARIFA-positivity, which was measured at the invasive front, was associated with PoT-low (p = 0.009), e.g., higher stroma content, and lower vessel density (p = 0.0059) measured at the luminal tumour surface. CONCLUSION: Here, we validated the relationship between SARIFA-status and prognosis in CRC patients and provided first evidence for a potential prognostic relevance in the subgroup of rectal cancer patients. Interestingly, CRCs with different SARIFA-status also showed histological differences measurable at the luminal tumour surface. Further studies to better understand the relationship between high luminal intratumoural stroma content and absence of a stroma reaction at the invasive front (SARIFA-positivity) are warranted and may inform future treatment decisions in CRC patients.
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BACKGROUND AND PURPOSE: Currently, contrast-enhancing margins on T1WI are used to guide treatment of gliomas, yet tumor invasion beyond the contrast-enhancing region is a known confounding factor. Therefore, this study used postmortem tissue samples aligned with clinically acquired MRIs to quantify the relationship between intensity values and cellularity as well as to develop a radio-pathomic model to predict cellularity using MR imaging data. MATERIALS AND METHODS: This single-institution study used 93 samples collected at postmortem examination from 44 patients with brain cancer. Tissue samples were processed, stained with H&E, and digitized for nuclei segmentation and cell density calculation. Pre- and postgadolinium contrast T1WI, T2 FLAIR, and ADC images were collected from each patient's final acquisition before death. In-house software was used to align tissue samples to the FLAIR image via manually defined control points. Mixed-effects models were used to assess the relationship between single-image intensity and cellularity for each image. An ensemble learner was trained to predict cellularity using 5 × 5 voxel tiles from each image, with a two-thirds to one-third train-test split for validation. RESULTS: Single-image analyses found subtle associations between image intensity and cellularity, with a less pronounced relationship in patients with glioblastoma. The radio-pathomic model accurately predicted cellularity in the test set (root mean squared error = 1015 cells/mm2) and identified regions of hypercellularity beyond the contrast-enhancing region. CONCLUSIONS: A radio-pathomic model for cellularity trained with tissue samples acquired at postmortem examination is able to identify regions of hypercellular tumor beyond traditional imaging signatures.
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Neoplasias Encefálicas , Glioblastoma , Glioma , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/patología , Recuento de Células , Glioblastoma/diagnóstico por imagen , Glioblastoma/patología , Glioma/diagnóstico por imagen , Glioma/patología , Humanos , Imagen por Resonancia Magnética/métodos , Márgenes de EscisiónRESUMEN
BACKGROUND: Microsatellite instability (MSI)/mismatch repair deficiency (dMMR) is a key genetic feature which should be tested in every patient with colorectal cancer (CRC) according to medical guidelines. Artificial intelligence (AI) methods can detect MSI/dMMR directly in routine pathology slides, but the test performance has not been systematically investigated with predefined test thresholds. METHOD: We trained and validated AI-based MSI/dMMR detectors and evaluated predefined performance metrics using nine patient cohorts of 8343 patients across different countries and ethnicities. RESULTS: Classifiers achieved clinical-grade performance, yielding an area under the receiver operating curve (AUROC) of up to 0.96 without using any manual annotations. Subsequently, we show that the AI system can be applied as a rule-out test: by using cohort-specific thresholds, on average 52.73% of tumors in each surgical cohort [total number of MSI/dMMR = 1020, microsatellite stable (MSS)/ proficient mismatch repair (pMMR) = 7323 patients] could be identified as MSS/pMMR with a fixed sensitivity at 95%. In an additional cohort of N = 1530 (MSI/dMMR = 211, MSS/pMMR = 1319) endoscopy biopsy samples, the system achieved an AUROC of 0.89, and the cohort-specific threshold ruled out 44.12% of tumors with a fixed sensitivity at 95%. As a more robust alternative to cohort-specific thresholds, we showed that with a fixed threshold of 0.25 for all the cohorts, we can rule-out 25.51% in surgical specimens and 6.10% in biopsies. INTERPRETATION: When applied in a clinical setting, this means that the AI system can rule out MSI/dMMR in a quarter (with global thresholds) or half of all CRC patients (with local fine-tuning), thereby reducing cost and turnaround time for molecular profiling.
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Neoplasias Colorrectales , Inestabilidad de Microsatélites , Inteligencia Artificial , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Reparación de la Incompatibilidad de ADN/genética , Detección Precoz del Cáncer , HumanosRESUMEN
BACKGROUND: Alveolar cleft grafting is a necessary procedure to restore bone defects. Randomized clinical trials (RCTs) are regarded as a golden standard for investigating the efficacy of treatments. Nevertheless, risk of bias (RoB) can still affect the validity of these trials. We aimed to conduct a systemic review of all control trials (CTs) using regenerative materials for alveolar cleft reconstructions to evaluate their RoB and perform a meta-analysis of new bone formation. METHODS: Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (PubMed), EMBASE AND Google Scholar were searched up to October 2020. Thereafter, the articles underwent quality assessment (according to the Jadad scale and the Delphi list) for the evaluation of the RoB. RESULTS: A total of 15 trials met the inclusion criteria, none of which reached a full score. Of these, 20% didn't randomize the trails, 73,33% failed to describe the way of randomization, and none reported the double-blinded criteria. Furthermore, allocation concealment (99.9%), intention to treat (100%), and patient awareness (100%) were inadequately described. The meta-analysis found no significant difference between regenerative materials and iliac crest graft. CONCLUSION: This review showed high RoB in CTs implying quality improvement of CTs is necessary. Meta-analysis showed no significant difference between the regenerative materials and autogenous grafts.
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Injerto de Hueso Alveolar , Fisura del Paladar , Autoinjertos , Fisura del Paladar/cirugía , Humanos , IlionRESUMEN
BACKGROUND: Exposure to particulate matter (PM) emitted from biomass burning is an increasing concern, particularly in Southeast Asia. It is not yet clear how the source of PM influences the risk of an adverse health outcome. The objective of this study was to quantify and compare health risks of PM from biomass burning and non-biomass burning sources in northern Thailand. METHODS: We collected ambient air pollutant data (PM with a diameter of < 10 µm [PM10], PM2.5, Carbon Monoxide [CO], Ozone [O3], and Nitrogen Dioxide [NO2]) from ground-based monitors and daily outpatient hospital visits in Thailand during 2014-2017. Outpatient data included chronic lower respiratory disease (CLRD), ischaemic heart disease (IHD), and cerebrovascular disease (CBVD). We performed an ecological time series analysis to evaluate the association between daily air pollutants and outpatient visits. We used the 90th and 95th percentiles of PM10 concentrations to determine days of exposure to PM predominantly from biomass burning. RESULTS: There was significant intra annual variation in PM10 levels, with the highest concentrations occurring during March, coinciding with peak biomass burning. Incidence Rate Ratios (IRRs) between daily PM10 and outpatient visits were elevated most on the same day as exposure for CLRD = 1.020 (95% CI: 1.012 to 1.028) and CBVD = 1.020 (95% CI: 1.004 to 1.035), with no association with IHD = 0.994 (95% CI: 0.974 to 1.014). Adjusting for CO tended to increase effect estimates. We did not find evidence of an exposure response relationship with levels of PM10 on days of biomass burning. CONCLUSIONS: We found same-day exposures of PM10 to be associated with certain respiratory and cardiovascular outpatient visits. We advise implementing measures to reduce population exposures to PM wherever possible, and to improve understanding of health effects associated with burning specific types of biomass in areas where such large-scale activities occur.
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Contaminantes Atmosféricos/efectos adversos , Biomasa , Enfermedades Cardiovasculares/epidemiología , Incendios , Material Particulado/efectos adversos , Enfermedades Respiratorias/epidemiología , Adolescente , Adulto , Anciano de 80 o más Años , Contaminación del Aire/efectos adversos , Animales , Enfermedades Cardiovasculares/etiología , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Enfermedades Respiratorias/etiología , Factores de Riesgo , Tailandia/epidemiología , Adulto JovenRESUMEN
OBJECTIVE/BACKGROUND: Posterior fossa (PF) recurrences of supratentorial (ST) World Health Organization (WHO) grade II and III gliomas are thought to be rare and to have grim prognoses. METHODS: This study entailed searching through our database and reviewing the records of patients with grade II and III ST gliomas who developed PF recurrence with no overt secondary gliomatosis or leptomeningeal spread. RESULTS: Of 2266 grade II and III gliomas, 14 fulfilled the inclusion criteria: 5 oligodendrogliomas (O; 1 OII, 4 OIII); 7 astrocytomas (A; 4 AII, 3 AIII); and 2 oligoastrocytomas (OA; both OAIII). The male/female gender ratio was 10/4, and median age at recurrence was 43 years. Two groups were identified. In one group (n=8; 1 AII, 3 AIII, 2 OAIII, 2 OIII), a rapidly growing contrast-enhancing PF mass (6/8) was associated with ST progression, and median survival time after detection was only 6.5 months despite radiotherapy and/or chemotherapy. In the second group (n=6; 3 AII, 1 OII, and 2 OIII), a non-contrast-enhancing (5/6), asymptomatic (5/6), slow-growing PF mass remained isolated, and treatment with radio- or chemotherapy produced objective responses in three patients and durable stabilization in the remaining three. After a median follow-up of 63months, only one patient died due to delayed recurrence of the ST lesion, while the remaining five patients are still alive. CONCLUSION: Non-contiguous PF relapses of ST grade II and III gliomas are rare. A high-grade ST tumor that is concomitantly progressing appears to be a predictor of poor survival. Conversely, the tumor course may be indolent if the ST lesion is low-grade and non-progressive at the time of PF involvement. The possible mechanism(s) behind this tropism are also discussed.
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Glioma/patología , Neoplasias Infratentoriales/secundario , Neoplasias Supratentoriales/patología , Adulto , Femenino , Glioma/diagnóstico , Glioma/mortalidad , Glioma/terapia , Humanos , Neoplasias Infratentoriales/diagnóstico , Neoplasias Infratentoriales/mortalidad , Neoplasias Infratentoriales/terapia , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Estudios Retrospectivos , Neoplasias Supratentoriales/diagnóstico , Neoplasias Supratentoriales/mortalidad , Neoplasias Supratentoriales/terapia , Análisis de Supervivencia , Organización Mundial de la Salud , Adulto JovenRESUMEN
BACKGROUND AND PURPOSE: Patients with recurrent glioblastoma often exhibit regions of diffusion restriction following the initiation of bevacizumab therapy. Studies suggest that these regions represent either diffusion-restricted necrosis or hypercellular tumor. This study explored postmortem brain specimens and a population analysis of overall survival to determine the identity and implications of such lesions. MATERIALS AND METHODS: Postmortem examinations were performed on 6 patients with recurrent glioblastoma on bevacizumab with progressively growing regions of diffusion restriction. ADC values were extracted from regions of both hypercellular tumor and necrosis. A receiver operating characteristic analysis was performed to define optimal ADC thresholds for differentiating tissue types. A retrospective population study was also performed comparing the overall survival of 64 patients with recurrent glioblastoma treated with bevacizumab. Patients were separated into 3 groups: no diffusion restriction, diffusion restriction that appeared and progressed within 5 months of bevacizumab initiation, and delayed or stable diffusion restriction. An additional analysis was performed assessing tumor O6-methylguanine-DNA-methyltransferase methylation. RESULTS: The optimal ADC threshold for differentiation of hypercellularity and necrosis was 0.736 × 10-3mm2/s. Progressively expanding diffusion restriction was pathologically confirmed to be coagulative necrosis surrounded by viable tumor. Progressive lesions were associated with the worst overall survival, while stable lesions showed the greatest overall survival (P < .05). Of the 40% of patients with O6-methylguanine-DNA-methyltransferase methylated tumors, none developed diffusion-restricted lesions. CONCLUSIONS: Progressive diffusion-restricted lesions were pathologically confirmed to be coagulative necrosis surrounded by viable tumor and associated with decreased overall survival. Stable lesions were, however, associated with increased overall survival. All lesions were associated with O6-methylguanine-DNA-methyltransferase unmethylated tumors.
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Neoplasias Encefálicas/patología , Glioblastoma/patología , Recurrencia Local de Neoplasia/patología , Adulto , Anciano , Antineoplásicos/uso terapéutico , Bevacizumab/uso terapéutico , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/tratamiento farmacológico , Imagen de Difusión por Resonancia Magnética/métodos , Femenino , Glioblastoma/diagnóstico por imagen , Glioblastoma/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Necrosis/diagnóstico por imagen , Necrosis/patología , Recurrencia Local de Neoplasia/diagnóstico por imagen , Recurrencia Local de Neoplasia/mortalidad , Estudios RetrospectivosRESUMEN
Glioblastoma (GBM) is one of the most aggressive types of cancer with limited therapeutic options and unfavorable prognosis. Stemness and non-classical epithelial-to-mesenchymal transition (ncEMT) features underlie the switch from normal to neoplastic states as well as resistance of tumor clones to current therapies. Therefore, identification of ligand/receptor systems maintaining this privileged state is needed to devise efficient cancer therapies. In this study, we show that the expression of CD95 associates with stemness and EMT features in GBM tumors and cells and serves as a prognostic biomarker. CD95 expression increases in tumors and with tumor relapse as compared with non-tumor tissue. Recruitment of the activating PI3K subunit, p85, to CD95 death domain is required for maintenance of EMT-related transcripts. A combination of the current GBM therapy, temozolomide, with a CD95 inhibitor dramatically abrogates tumor sphere formation. This study molecularly dissects the role of CD95 in GBM cells and contributes the rational for CD95 inhibition as a GBM therapy.
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Neoplasias Encefálicas/genética , Transición Epitelial-Mesenquimal/genética , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Recurrencia Local de Neoplasia/genética , Receptor fas/genética , Antineoplásicos Alquilantes/farmacología , Neoplasias Encefálicas/clasificación , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/patología , Fosfatidilinositol 3-Quinasa Clase Ia/genética , Fosfatidilinositol 3-Quinasa Clase Ia/metabolismo , Dacarbazina/análogos & derivados , Dacarbazina/farmacología , Combinación de Medicamentos , Sinergismo Farmacológico , Glioblastoma/clasificación , Glioblastoma/mortalidad , Glioblastoma/patología , Humanos , Inmunoglobulina G/farmacología , Recurrencia Local de Neoplasia/clasificación , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/patología , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Cultivo Primario de Células , Pronóstico , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes de Fusión/farmacología , Transducción de Señal , Esferoides Celulares/efectos de los fármacos , Esferoides Celulares/metabolismo , Esferoides Celulares/patología , Análisis de Supervivencia , Temozolomida , Receptor fas/metabolismo , Receptor fas/farmacologíaRESUMEN
OBJECTIVE: To determine the status of existing violence and injury prevention (VIP) efforts and surveillance systems in the Caribbean. SUBJECTS AND METHODS: The Caribbean Public Health Agency undertook a survey to gather evidence of VIP in 24 member Countries. The survey was administered to national epidemiologists and non-communicable disease focal points in October 2015 using an online tool, Survey Monkey. Questions were asked about the availability in each country of VIP representative surveys, policies,action plans, laws, victim support services and surveillance systems.RESULTS: Nineteen (79%) countries completed the VIP survey. Only three (16%) countries confirmed having undertaken a nationally representative survey. Twelve (63%) had not developed a national policy and 14 (74%) had not implemented an action plan on VIP. Each country reported the existence of VIP laws and offered victim support services, though average enforcement ranged from 4079%. Nine (47%) countries indicated using an injury registry and 15 (79%) reported collecting injury data within patient records, mainly from public hospitals. All 19 countries confirmed that records of reported violent incidents were maintained by the police. Unique identifiers were generally lacking in registries and police systems. Only four (44%) countries with registries, ten (67%) countries with inpatient injury data and 12 (63%) countries with police records indicated sharing data with other organizations. CONCLUSION: Each country reported some level of injury surveillance system; however, such systems should be harmonized to produce more complete baseline data. The use of unique identifiers is required to reduce duplication and effectively link surveillance systems.
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Humanos , Violencia , Vigilancia en Desastres , Región del CaribeRESUMEN
For differentiation-defective malignancies, compounds that modulate transcription, such as retinoic acid and histone deacetylase (HDAC) inhibitors, are of particular interest. HDAC inhibitors are currently under investigation for the treatment of a broad spectrum of cancer diseases. However, one clinical drawback is class-specific toxicity of unselective inhibitors, limiting their full anticancer potential. Selective targeting of individual HDAC isozymes in defined tumor entities may therefore be an attractive alternative treatment approach. We have previously identified HDAC family member 8 (HDAC8) as a novel target in childhood neuroblastoma. Using small-molecule inhibitors, we now demonstrate that selective inhibition of HDAC8 exhibits antineuroblastoma activity without toxicity in two xenograft mouse models of MYCN oncogene-amplified neuroblastoma. In contrast, the unselective HDAC inhibitor vorinostat was more toxic in the same models. HDAC8-selective inhibition induced cell cycle arrest and differentiation in vitro and in vivo. Upon combination with retinoic acid, differentiation was significantly enhanced, as demonstrated by elongated neurofilament-positive neurites and upregulation of NTRK1. Additionally, MYCN oncogene expression was downregulated in vitro and tumor cell growth was markedly reduced in vivo. Mechanistic studies suggest that cAMP-response element-binding protein (CREB) links HDAC8- and retinoic acid-mediated gene transcription. In conclusion, HDAC-selective targeting can be effective in tumors exhibiting HDAC isozyme-dependent tumor growth in vivo and can be combined with differentiation-inducing agents.
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Histona Desacetilasas/metabolismo , Neuroblastoma/metabolismo , Proteínas Represoras/metabolismo , Tretinoina/farmacología , Animales , Western Blotting , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Femenino , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/genética , Humanos , Ácidos Hidroxámicos , Indoles/farmacología , Ratones , Ratones Desnudos , Proteínas Represoras/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
An appropriate bony situation is essential for dental implant placement and bony support of soft tissues (pink esthetic). Loss of teeth often results in complex horizontal and vertical alveolar ridge defects. They demand advanced bone augmentation techniques for reconstruction. We present the different techniques and materials used in complex bone augmentation. Clinical cases show the application of the methods in the clinical setting. We present current techniques and materials used in complex bone augmentations. Clinical cases show the application of the methods in the clinical setting. Applied techniques include stabilized-guided bone regeneration (GBR), autologous local block augmentation, modified techniques such as Gellrich shell technique including piezosurgery, pelvic bone blocks, complex materials such as graft-derived bone blocks and their unique handling problems. Successful basic principles are reduction of cortical bone healing due to long remodeling time and possible late loss; extended application of materials with interconnecting porous system and particulate material resulting in fast healing analogous to cancellous bone; mechanical stabilization of the augmentation to allow bony healing in vertical defect situations. GBR and autologous bone blocks with minimal cortical thickness and a high volume of particulated material are most favorable techniques.
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Trasplante Óseo , Implantes Dentales , Regeneración Tisular Guiada Periodontal/métodos , Animales , HumanosRESUMEN
AIMS: Combined deletion of the whole chromosomal arms 1p and 19q is a frequent event in oligodendroglial tumours. Recent identification of recurrent mutations in CIC on 19q and FUBP1 on 1p and their mutational patterns suggest a loss of function of the respective proteins. Surprisingly, oligoastrocytomas harbouring identical genetic characteristics regarding 1p/19q codeletion and frequent IDH1/2 mutations have been shown to carry CIC mutations in a significantly lower number of cases. The present study investigates whether epigenetic modification may result in silencing of CIC. METHODS: As IDH1/2 mutation-mediated DNA hypermethylation is a prominent feature of these tumours, we analysed a set of CIC wild-type oligoastrocytomas and other diffuse gliomas with regard to 1p/19q status for presence of CIC-associated CpG island methylation by methylation-specific PCR. RESULTS: Both methylation-specific PCR and subsequent bisulphite-sequencing of selected cases revealed an unmethylated status in all samples. CONCLUSION: Despite the hypermethylator phenotype in IDH1/2 mutant tumours and recent detection of gene silencing particularly on retained alleles in oligodendroglial tumours, hypermethylation of CIC-associated CpG islands does not provide an alternative mechanism of functional CIC protein abrogation.
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Neoplasias Encefálicas/genética , Cromosomas Humanos Par 19 , Cromosomas Humanos Par 1 , Islas de CpG/genética , Metilación de ADN , Oligodendroglioma/genética , Neoplasias Encefálicas/patología , Metilación de ADN/genética , Predisposición Genética a la Enfermedad , Humanos , Pérdida de Heterocigocidad/genética , Mutación/genéticaRESUMEN
OBJECTIVES: Tetragonal zirconia polycrystal (TZP) materials are widely used for full ceramic partial dentures, even though their mechanical properties might change during service. A key property for the durability of the constructs is thought to be an inhibition of crack propagation by phase transformation toughening. Because dental prosthesis are ground and polished for adjustment purposes, it is important to understand the effects of mechanical surface treatments, on localized transformation and around the propagating cracks. METHODS: Sintered samples of commercially available 3 mol-% Yittria-doped TZP were ground and polished and the surface structure and phase composition were compared with those of re-transformed annealed samples. Microindentation was used to induce cracks and nanoindentation was performed to determine the local variety of hardness and indentation modulus, coupled with XRD and SEM investigations. RESULTS: Y-TZP polished surfaces exhibited 9% monoclinic phase content and have reduced hardness and indentation modulus amounting 16.3 GPa and 210.6 GPa, respectively. Y-TZP re-transformed annealed sample revealed 19.4 GPa and 242.3 GPa, respectively. A localized reduction of the stiffness around the crack tips on the annealed surface reveals an irregular arrangement of t-m-transformed grains. Electron micrographs show more damage on the transformed surface following microindentation than on indented annealed surfaces. SIGNIFICANCE: Y-TZP prostheses are adapted and roughened by clinicians prior to bonding to teeth. Annealing recovers properties and microstructure that is changed by the adaptation of the outer layer. This might be important to ensure long-term toughening functionality of the dentures and optimal comfort for the patients.
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Prótesis Dental , Itrio/química , Circonio/química , Diseño de Prótesis Dental , Dureza , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Transición de Fase , Propiedades de Superficie , Difracción de Rayos XRESUMEN
PURPOSE: To evaluate the influence of two different tooth preparation forms, two luting space settings and two cement types on the marginal and internal adaptation of all-ceramic crown copings produced using Cerec3 CAD/CAM system. MATERIALS AND METHODS: Forty working stone dies were made from two metal master casts (1. Tooth 36: with anatomic occlusal reduction, 2. Tooth 36: with flat occlusal reduction). Forty crown copings were milled using Vita In-Ceram 2000 YZ: 20 with an luting space settings of 0 = 100 microm and 20 with -50 = 50 microm. Copings were cemented using two cements (zinc phosphate cement, P21: Panavia21), then embedded and sectioned bucco-lingually and mesio-distally. Widths of marginal and internal gaps were measured using a light microscope at magnification of 40X. Data were submitted to one-way ANOVA, and statistical significance was set at p < 0.05. RESULTS: Copings with flat occlusal reduction and luting space settings of 100 pm had a better internal and marginal fit compared with copings with anatomic occlusal reduction and luting space settings of 50 microm, regardless of the cement used. P21 showed a significantly better fit compared with zinc phosphate cement. CONCLUSION: The presented Cerec3 CAD/CAM system can provide a marginal and internal adaptation which is comparable to that of conventional cast and conventional all-ceramic crowns.
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Cementación/métodos , Diseño Asistido por Computadora , Coronas , Adaptación Marginal Dental , Diseño de Prótesis Dental , Preparación Protodóncica del Diente/métodos , Análisis de Varianza , Porcelana Dental , Humanos , Modelos Dentales , Diente Molar , Fosfatos , Ajuste de Prótesis , Cementos de Resina , Estadísticas no Paramétricas , Cemento de Fosfato de ZincRESUMEN
Siliceous sponge spicules contain silicateins--proteins taking part in biogenic silica precipitation and determination of the spicule morphological features. The exon-intron structure of four silicatein-alpha isoforms: -alpha1,-alpha2, -alpha3 and -alpha4 from endemic baikalian sponge Lubomirskia baicalensis was studied. For eight sponge species, including both cosmopolitan (Spongilla lacustris, Ephydatia muelleri, E. fluviatilis) and Baikal endemic (L. baicalensis, L. incrustans, Baikalospongia intermedia, B. fungiformis, Sw. papyracea) species, seventeen gene fragment sequences of different silicatein isoforms were determined. It was shown that cosmopolitan and endemic Baikalian sponges differ from each other by gene structure (have different length ofintrons). Among Baikalian sponges silicatein-alpha1 has the most variable intron length, and silicatein-alpha4 is the most conservative. Phylogenetic analysis of amino-acid silicatein sequences allow identify different silicatein isoforms, which authentically differ form four clusters on phylogenetic tree. Phylogenetic analysis of exon-intron sequences gives the possibility to separate different sponge species in the clusters.
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Catepsinas/genética , Poríferos/genética , Animales , Evolución Molecular , Exones/genética , Agua Dulce , Intrones/genética , Filogenia , Poríferos/clasificaciónRESUMEN
Full-ceramic zirconia crowns and bridges have become very popular with dentists and patients because of their excellent esthetics and mechanical properties. We studied phase transformations within the outermost surface layer of 3 mol.% yttria-stabilized zirconia (Y-TZP) samples of small, clinically relevant thicknesses, manipulated by polishing, grinding and fracture as might be encountered in everyday clinical practice. Stress-induced transformations of the tetragonal phase were studied in three dimensions in order to better understand the organization and extent of the monoclinically transformed phase. By means of laboratory- and synchrotron-based X-ray diffraction measurements, coupled with electron microscopy and multimodal tomography, it was possible for the first time to visualize and quantify the phase distributions non-destructively and in three dimensions. Highly variable degrees of local transformation result in ragged transformed zones of very inhomogeneous thickness. The overall thickness of the transformation layers strongly depends on the severity and rate of loading. Gentle diamond cutting resulted in surprisingly low transformation ratios of less than 0.1%. When Y-TZP constructions are manipulated before bonding, toughness of the outer layers is reduced and they may become brittle with important implications for the stability of the bond: dental practitioners thus need to be cautious when altering the surfaces of these materials after sintering.
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Pulido Dental/efectos adversos , Prótesis Dental , Circonio/química , Materiales Biocompatibles/química , Fuerza Compresiva , Análisis del Estrés Dental , Dureza , Humanos , Ensayo de Materiales , Propiedades de Superficie , Difracción de Rayos XRESUMEN
BACKGROUND: Hemangiopericytomas (HPs) of the central nervous system are rare tumors and afflicted with a high propensity of recurrences and metastases. Histopathologically, HPs correspond to differentiated (WHO grade II) and anaplastic (WHO grade III) tumors. With respect to the available literature and our own experiences, the aggressiveness, especially of differentiated grade II HPs, seems to be underestimated. METHODS: Thus, in this retrospective study, we describe tumor behavior and examined the effect of radio- and chemotherapy on tumor control with respect to the WHO classification of grade II and III neoplasms. This study consists of 15 patients with cerebral (n = 10) and spinal (n = 5) HPs. RESULTS: Seven HPs were histopathologically classified as grade II and eight as anaplastic grade III tumors. Complete surgical resection could be achieved in 60% of cerebral and in 25% of spinal HPs. In total, local recurrences occurred in 20% of patients within 17.3 months after the primary operation. Recurrences occurred both from differentiated (n = 1) and anaplastic (n = 2) neoplasms. Treatment comprised re-operation followed by radio- and chemotherapy. Pointing out the importance of the extent of surgical resection, in this study, we could not detect a single patient showing any recurrences or systemic metastases after complete surgical resection of grade II HPs. During primary diagnostics, four patients showed systemic metastases. Although these tumors could be controlled via surgery, systemic metastases appeared in further four patients within 60.4 months. Interestingly, two of them were classified as differentiated tumors (WHO grade II). To control tumor progress, radiotherapy seemed to be partially effective. On the other hand, however, chemotherapy did not show any effect on tumor control. With respect to these results, screening investigations seem to be indispensable and are highly recommended during primary diagnostics and after the appearance of recurrences or metastases, independent of the histopathological staging of the tumor. CONCLUSION: With respect to our results, radical surgical resection offers the best treatment option to control tumor progress. In case of subtotal resection or histopathologically diagnosed anaplasia (WHO III), radiotherapy seems to be indicated; however, chemotherapy did not show effectiveness to control tumor progress.
Asunto(s)
Neoplasias Encefálicas/patología , Neoplasias Encefálicas/secundario , Hemangiopericitoma/patología , Hemangiopericitoma/secundario , Neoplasias de la Columna Vertebral/patología , Neoplasias de la Columna Vertebral/secundario , Adulto , Anciano , Neoplasias Encefálicas/clasificación , Desdiferenciación Celular/fisiología , Femenino , Hemangiopericitoma/clasificación , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/clasificación , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/patología , Estudios Retrospectivos , Neoplasias de la Columna Vertebral/clasificación , Adulto JovenAsunto(s)
Anticuerpos Monoclonales/administración & dosificación , Síndrome Inflamatorio de Reconstitución Inmune/diagnóstico , Síndrome de Abstinencia a Sustancias/diagnóstico , Adulto , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Femenino , Humanos , Síndrome Inflamatorio de Reconstitución Inmune/etiología , Síndrome Inflamatorio de Reconstitución Inmune/patología , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/patología , Natalizumab , Síndrome de Abstinencia a Sustancias/etiología , Síndrome de Abstinencia a Sustancias/patologíaRESUMEN
BACKGROUND: The proportion of epithelial and stromal cells in tumours is thought to have an important role in the progression of epithelial malignancy. We aimed to determine whether the relative proportion of tumour (PoT) was related to survival in colorectal cancer. METHODS: The PoT at the luminal surface was measured by point counting using virtual tissue sections in a series of 145 colorectal cancer cases. The relationship of PoT to clinicopathological parameters including cancer-specific survival was analysed. Modified receiver operating characteristic curves were used to determine the optimum cut off points to dichotomise the data for survival analyses. RESULTS: Tumours with PoT-low (Asunto(s)
Adenocarcinoma/mortalidad
, Adenocarcinoma/patología
, Neoplasias Colorrectales/mortalidad
, Neoplasias Colorrectales/patología
, Anciano
, Área Bajo la Curva
, Femenino
, Humanos
, Estimación de Kaplan-Meier
, Masculino
, Persona de Mediana Edad
, Estadificación de Neoplasias
, Pronóstico
, Curva ROC