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Pt is an excellent and widely used hydrogen evolution reaction (HER) catalyst. However, it is a rare and expensive metal, and alternative catalysts are being sought to facilitate the hydrogen economy. As tungsten carbide (WC) has a Pt-like occupied density of states, it is expected to exhibit catalytic activity. However, unlike Pt, excellent catalytic activity has not yet been observed for mono WC. One of the intrinsic differences between WC and Pt is in their magnetic properties; WC is non-magnetic, whereas Pt exhibits high magnetic susceptibility. In this study, the WC lattice was doped with ferromagnetic Co nanocrystals to introduce an ordered-spin atomic configuration. The catalytic activity of the Co-doped WC was â¼30% higher than that of Pt nanoparticles for the HER during the hydrolysis of ammonia borane (NH3BH3), which is currently attracting attention as a hydrogen fuel source. Measurements of the magnetisation, enthalpy of adsorption, and activation energy indicated that the synergistic effect of the WC matrix promoting hydrolytic cleavage of NH3BH3 and the ferromagnetic Co crystals interacting with the nucleus spin of the protons was responsible for the enhanced catalytic activity. This study presents a new catalyst design strategy based on the concept of an internal magnetic field. The WC-Co material presented here is expected to have a wide range of applications as an HER catalyst.
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BACKGROUND: The relationship between dental anxiety and mucosal wound healing, especially the inflammatory response, has not been well studied. This study aimed to examine the relationship between anxiety prior to dental treatment and short-term inflammation following impacted mandibular third molar (IMTM) surgery. METHODS: Fifty-nine patients who required IMTM surgery were recruited for this study. Sample demographics (gender, age) and surgical extent (Pederson classification, duration) were collected. Psychological stress towards surgery was assessed by the Dental Fear Survey (DFS). All surgeries were conducted according to an identical surgical protocol and all patients were given the same medical prescription. Correlations between short-term inflammation (swelling and trismus after 2 days) and DFS, demographics and surgical extent were statistically analysed. RESULTS: The results showed that patients with a higher DFS score demonstrated more severe swelling (ß = 0.36, P = 0.016) and trismus (ß = 0.37, P = 0.008) 2 days after surgery. In addition, more severe trismus occurred following more difficult surgery (ß = 0.29, P = 0.016) or that with a longer duration (ß = 0.21, P = 0.081). Neither gender nor age showed any significant relationship with swelling or trismus. CONCLUSION: Short-term inflammatory response following IMTM surgery correlated with the preoperative dental anxiety and this correlation was independent of gender and surgical extent.
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Ansiedad al Tratamiento Odontológico , Diente Impactado , Humanos , Tercer Molar/cirugía , Dolor Postoperatorio , Extracción Dental , Diente Impactado/cirugíaRESUMEN
AML is a genetically heterogeneous disease and understanding how different co-occurring mutations cooperate to drive leukemogenesis will be crucial for improving diagnostic and therapeutic options for patients. MIR142 mutations have been recurrently detected in IDH-mutated AML samples. Here, we have used a mouse model to investigate the interaction between these two mutations and demonstrate a striking synergy between Mir142 loss-of-function and IDH2R140Q, with only recipients of double mutant cells succumbing to leukemia. Transcriptomic analysis of the non-leukemic single and leukemic double mutant progenitors, isolated from these mice, suggested a novel mechanism of cooperation whereby Mir142 loss-of-function counteracts aberrant silencing of Hoxa cluster genes by IDH2R140Q. Our analysis suggests that IDH2R140Q is an incoherent oncogene, with both positive and negative impacts on leukemogenesis, which requires the action of cooperating mutations to alleviate repression of Hoxa genes in order to advance to leukemia. This model, therefore, provides a compelling rationale for understanding how different mutations cooperate to drive leukemogenesis and the context-dependent effects of oncogenic mutations.
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Regulación Leucémica de la Expresión Génica/fisiología , Proteínas de Homeodominio/metabolismo , Isocitrato Deshidrogenasa/metabolismo , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , MicroARNs/metabolismo , Animales , Carcinogénesis/genética , Carcinogénesis/patología , Línea Celular Tumoral , Femenino , Regulación Leucémica de la Expresión Génica/genética , Genotipo , Proteínas de Homeodominio/genética , Humanos , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/genética , Masculino , Ratones , MicroARNs/genética , Mutación/genéticaRESUMEN
BACKGROUND: The right hepatic venous system consists of the right hepatic vein (RHV) and inferior RHVs (IRHVs). When the right posterior section is used as a graft for liver transplantation, understanding variations and relationships between the RHV and IRHVs is critical for graft venous return and hepatic vein reconstruction. This study aimed to evaluate variations in the hepatic veins and the relationships between them. METHODS: The medical records and CT images of patients who underwent hepatectomy as liver donors were assessed retrospectively. The relationship between the veins was evaluated by three-dimensional CT. RESULTS: The configuration of the posterior section was classified into one of eight types based on the RHV and IRHVs in 307 patients. Type 1a (103 of 307), type 1b (139 of 307) and type 2a (40 of 307) accounted for 91·9 per cent of the total. The diameter of the RHV extending towards the inferior vena cava had a significant inverse correlation with that of the IRHV (r2 = -0·615, P < 0·001). Type 1a, which had no IRHVs, had the RHV with the largest diameter; conversely, type 2a, which had a large IRHV, had the RHV with the smallest diameter. CONCLUSION: The hepatic venous system of the right posterior section was classified into eight types, with an inverse relationship between RHV and IRHV sizes. This information is useful for segment VII resection or when the right liver is used as a transplant graft.
ANTECEDENTES: El sistema venoso hepático derecho consiste en la vena hepática derecha (right hepatic vein, RHV) y las RHVs inferiores (IRHVs). Cuando se utiliza la sección posterior derecha hepática como injerto para el trasplante hepático, es fundamental conocer las variaciones e interrelaciones entre la RHV y las IRHVs para el retorno venoso del injerto y la reconstrucción de la vena hepática. El objetivo de este estudio fue determinar las variaciones en las venas hepáticas y sus interrelaciones. MÉTODOS: Se evaluaron retrospectivamente las historias clínicas y las imágenes de la tomografía computarizada de los pacientes que se sometieron a una hepatectomía como donantes vivos para trasplante hepático. La interrelación entre las venas se evaluó mediante imágenes de CT tridimensional. RESULTADOS: La configuración de la sección posterior clasificó a 307 pacientes en base a la RHV y a las IRHVs. Se clasificaron en 8 tipos, de los cuales el Tipo 1a (103/307), el Tipo 1b (139/307) y el Tipo 2a (40/307) representaron el 92% del total. El diámetro de la RHV que se extiende hacia la vena cava inferior presentó una correlación inversa significativa con la de las IRHV (r2: −0,632, P < 0,0001). El diámetro mayor de la RHV se observó en el Tipo 1a, que no presentaba IRHVs; por el contrario, el diámetro más pequeño se observó en el Tipo 2a que presentaba una IRHV grande. CONCLUSIÓN: El sistema venoso hepático de la sección posterior derecha se clasificó en 8 subtipos con una relación inversa entre los tamaños de la RHV y las IRHV. Esta información es útil cuando se practica una resección del segmento 7 o cuando se utiliza el hígado derecho como injerto para el trasplante.
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Venas Hepáticas/diagnóstico por imagen , Donantes de Tejidos , Venas Hepáticas/anatomía & histología , Venas Hepáticas/cirugía , Humanos , Imagenología Tridimensional , Hígado/irrigación sanguínea , Trasplante de Hígado/métodos , Estudios Retrospectivos , Tomografía Computarizada por Rayos XRESUMEN
Mechanical loading plays an important role in bone homeostasis. However, molecular mechanisms behind the mechanical regulation of bone homeostasis are poorly understood. We previously reported p130Cas (Cas) as a key molecule in cellular mechanosensing at focal adhesions. Here, we demonstrate that Cas is distributed in the nucleus and supports mechanical loading-mediated bone homeostasis by alleviating NF-κB activity, which would otherwise prompt inflammatory processes. Mechanical unloading modulates Cas distribution and NF-κB activity in osteocytes, the mechanosensory cells in bones. Cas deficiency in osteocytes increases osteoclastic bone resorption associated with NF-κB-mediated RANKL expression, leading to osteopenia. Upon shear stress application on cultured osteocytes, Cas translocates into the nucleus and down-regulates NF-κB activity. Collectively, fluid shear stress-dependent Cas-mediated alleviation of NF-κB activity supports bone homeostasis. Given the ubiquitous expression of Cas and NF-κB together with systemic distribution of interstitial fluid, the Cas-NF-κB interplay may also underpin regulatory mechanisms in other tissues and organs.
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Huesos/metabolismo , Proteína Sustrato Asociada a CrK/metabolismo , Homeostasis , FN-kappa B/metabolismo , Transducción de Señal , Estrés Mecánico , Animales , Biomarcadores , Resorción Ósea , Huesos/diagnóstico por imagen , Proteína Sustrato Asociada a CrK/genética , Expresión Génica , Ratones , Ratones Noqueados , Osteoclastos/metabolismo , Osteocitos/metabolismo , Ligando RANK/genética , Ligando RANK/metabolismo , Microtomografía por Rayos XRESUMEN
Microlipid vesicles (MLV) have a broad spectrum of applications for the delivery of molecules, ranging from chemical compounds to proteins, in both in vitro and in vivo conditions. In the present study, we developed a new set of nanosize multilayer lipid vesicles (NMVs) containing a unique combination of lipids. The NMVs enable the adsorption of histidine-tagged proteins at the vesicle surface and were demonstrated to be suitable for the in vivo delivery of antigens. The NMVs contained a combination of neutral (DOPC) and anionic (DPPG) lipids in the inner membrane and an external layer composed of DOPC, cholesterol, and a nickel-containing lipid (DGS-NTA [Ni]). NMVs combined with a recombinant form of the B subunit of the Shiga toxin (rStx2B) produced by certain enterohemorragic Escherichia coli (EHEC) strains enhanced the immunogenicity of the antigen after parenteral administration to mice. Mice immunized with rStx2B-loaded NMVs elicited serum antibodies capable of neutralizing the toxic activities of the native toxin; this result was demonstrated both in vitro and in vivo. Taken together, these results demonstrated that the proposed NMVs represent an alternative for the delivery of antigens, including recombinant proteins, generated in different expression systems.
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Anticuerpos Antibacterianos/inmunología , Sistemas de Liberación de Medicamentos/métodos , Escherichia coli Enterohemorrágica/inmunología , Infecciones por Escherichia coli/inmunología , Lípidos/química , Toxina Shiga/inmunología , Animales , Formación de Anticuerpos , Antígenos Bacterianos/administración & dosificación , Antígenos Bacterianos/química , Antígenos Bacterianos/inmunología , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/instrumentación , Escherichia coli Enterohemorrágica/genética , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/prevención & control , Femenino , Humanos , Inmunización , Ratones , Ratones Endogámicos BALB C , Nanopartículas/administración & dosificación , Nanopartículas/química , Toxina Shiga/administración & dosificación , Toxina Shiga/químicaRESUMEN
This paper reports a case of nosocomial transmission of Mycobacterium tuberculosis by brief casual contact. Routine variable number tandem repeat typing in Yamagata Prefecture, Japan found that M. tuberculosis clinical isolates from two patients showed indistinguishable genotypes. The patients had an epidemiological relationship of sharing a waiting room in a hospital on the same day. As comparative genomics detected only two single nucleotide variants between the isolates, it was concluded that recent tuberculosis transmission occurred in the waiting room. These results indicate that the physical separation of infectious tuberculosis patients is an essential control measure for preventing unpredictable nosocomial transmission by casual contact.
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Transmisión de Enfermedad Infecciosa , Genómica , Tipificación Molecular , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis/transmisión , Anciano de 80 o más Años , Femenino , Genotipo , Humanos , Japón , Masculino , Persona de Mediana Edad , Repeticiones de Minisatélite , Mycobacterium tuberculosis/clasificación , Mycobacterium tuberculosis/genética , Aislamiento de Pacientes , Polimorfismo de Nucleótido SimpleRESUMEN
BACKGROUND: Two false-positive tuberculosis (TB) cases in Yamagata Prefecture, Japan, 2016. OBJECTIVE: To report the effectiveness of comparative genomics of Mycobacterium tuberculosis for identification of cross-contamination cases. DESIGN: Case report of laboratory cross-contamination. RESULTS: Beginning with detection of an identical genotype in two M. tuberculosis strains using variable number of tandem repeat typing, we suspected M. tuberculosis cross-contamination of specimens collected in a mycobacteriology laboratory based on epidemiological investigations. This suspicion was confirmed using comparative genomics of the two M. tuberculosis strains and a strain from an epidemiologically unrelated specimen from the same batch as the two strains in the mycobacteriology laboratory. All strains had an identical genomic sequence with no single nucleotide variants. CONCLUSION: Comparative genomics, which offers the highest discrimination power, is a potent tool for identifying laboratory cross-contamination using epidemiological investigations.
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Reacciones Falso Positivas , Genómica , Mycobacterium tuberculosis/genética , Tuberculosis/microbiología , Genotipo , Humanos , Japón , Laboratorios de Hospital , Polimorfismo de Longitud del Fragmento de Restricción , Manejo de Especímenes , Tuberculosis/diagnósticoRESUMEN
Acute myeloid leukemia (AML) is an aggressive and lethal blood cancer originating from rare populations of leukemia stem cells (LSCs). AML relapse after conventional chemotherapy is caused by a remaining population of drug-resistant LSCs. Selective targeting of the chemoresistant population is a promising strategy for preventing and treating AML relapse. Polycomb repressive complex 2 (PRC2) trimethylates histone H3 at lysine 27 to maintain the stemness of LSCs. Here, we show that quiescent LSCs expressed the highest levels of enhancer of zeste (EZH) 1 and EZH2, the PRC2 catalytic subunits, in the AML hierarchy, and that dual inactivation of EZH1/2 eradicated quiescent LSCs to cure AML. Genetic deletion of Ezh1/2 in a mouse AML model induced cell cycle progression of quiescent LSCs and differentiation to LSCs, eventually eradicating AML LSCs. Quiescent LSCs showed PRC2-mediated suppression of Cyclin D, and Cyclin D-overexpressing AML was more sensitive to chemotherapy. We have developed a novel EZH1/2 dual inhibitor with potent inhibitory activity against both EZH1/2. In AML mouse models and patient-derived xenograft models, the inhibitor reduced the number of LSCs, impaired leukemia progression, and prolonged survival. Taken together, these results show that dual inhibition of EZH1/2 is an effective strategy for eliminating AML LSCs.
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Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Leucemia Mieloide Aguda/metabolismo , Células Madre Neoplásicas/metabolismo , Complejo Represivo Polycomb 2/antagonistas & inhibidores , Animales , Histonas/metabolismo , Humanos , Ratones , Ratones Endogámicos C57BLRESUMEN
Purpose. Radiation-induced oral mucositis is the most common side effect of radiotherapy in head and neck cancer; however, effective modalities for its prevention have not been established. In this study, we evaluated the effectiveness of Hangeshashinto (TJ-14), a Japanese herbal medicine, for preventing radiation-induced mucositis and elucidated its effect on inflammatory responses, including inflammatory cell chemotaxis and cyclooxygenase-2 (COX2) expression, in an animal model. Methods. Syrian hamsters, 89 weeks old, were enrolled in this study. Animals were irradiated with a single 40 Gy dose to the buccal mucosa. Hamsters freely received a treatment diet mixed with 2% TJ-14 or a normal diet daily. The therapeutic effect was determined based on the visual mucositis score, body weight, and histological examination of infiltrated neutrophils and COX2 expression. Results. TJ-14 significantly reduced the severity of mucositis. The percentage with severe mucositis (score ≥3) was 100% in the untreated group and 16.7% in the TJ-14 group (P < 0.05). There was no difference in body weight change between the groups; however, weight gain in the untreated group tended to be suppressed compared to that in the TJ-14 group during the peak period of mucositis. In addition, TJ-14 inhibited the infiltration of neutrophils and COX2 expression in irradiated mucosa (P < 0.05). Conclusions. TJ-14 reduced the severity of mucositis in an animal model by suppressing the inflammatory response. Because TJ-14 is inexpensive and its safety is established, it is a promising candidate for the standard treatment of radiation-induced mucositis in cancer patients (AU)
No disponible
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Animales , Mucositis/tratamiento farmacológico , Mucositis/radioterapia , Ciclooxigenasa 2/análisis , Medicamentos Herbarios Chinos/administración & dosificación , Medicamentos Herbarios Chinos/uso terapéutico , Quimiotaxis/efectos de la radiación , Mucositis/veterinaria , Modelos Animales , Radioterapia/efectos adversos , Radioterapia/veterinaria , Inflamación/complicaciones , Inflamación/veterinariaRESUMEN
After several experimental campaigns in the Kyushu University Experiment with Steady-state Spherical Tokamak (QUEST), the originally stainless steel plasma-facing wall (PFW) becomes completely covered with a deposited film composed of mixture materials, such as iron, chromium, carbon, and tungsten. In this work, an innovative colorimetry-based method was developed to measure the thickness of the deposited film on the actual QUEST wall. Because the optical constants of the deposited film on the PFW were position-dependent and the extinction coefficient k1 was about 1.0-2.0, which made the probing light not penetrate through some thick deposited films, the colorimetry method developed can only provide a rough value range of thickness of the metal-containing film deposited on the actual PFW in QUEST. However, the use of colorimetry is of great benefit to large-area inspections and to radioactive materials in future fusion devices that will be strictly prohibited from being taken out of the limited area.
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PURPOSE: Radiation-induced oral mucositis is the most common side effect of radiotherapy in head and neck cancer; however, effective modalities for its prevention have not been established. In this study, we evaluated the effectiveness of Hangeshashinto (TJ-14), a Japanese herbal medicine, for preventing radiation-induced mucositis and elucidated its effect on inflammatory responses, including inflammatory cell chemotaxis and cyclooxygenase-2 (COX2) expression, in an animal model. METHODS: Syrian hamsters, 8-9 weeks old, were enrolled in this study. Animals were irradiated with a single 40 Gy dose to the buccal mucosa. Hamsters freely received a treatment diet mixed with 2% TJ-14 or a normal diet daily. The therapeutic effect was determined based on the visual mucositis score, body weight, and histological examination of infiltrated neutrophils and COX2 expression. RESULTS: TJ-14 significantly reduced the severity of mucositis. The percentage with severe mucositis (score ≥3) was 100% in the untreated group and 16.7% in the TJ-14 group (P < 0.05). There was no difference in body weight change between the groups; however, weight gain in the untreated group tended to be suppressed compared to that in the TJ-14 group during the peak period of mucositis. In addition, TJ-14 inhibited the infiltration of neutrophils and COX2 expression in irradiated mucosa (P < 0.05). CONCLUSIONS: TJ-14 reduced the severity of mucositis in an animal model by suppressing the inflammatory response. Because TJ-14 is inexpensive and its safety is established, it is a promising candidate for the standard treatment of radiation-induced mucositis in cancer patients.
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Quimiotaxis/efectos de los fármacos , Ciclooxigenasa 2/química , Medicamentos Herbarios Chinos/uso terapéutico , Rayos gamma/efectos adversos , Inflamación/tratamiento farmacológico , Mucositis/tratamiento farmacológico , Traumatismos Experimentales por Radiación/prevención & control , Animales , Células Cultivadas , Cricetinae , Modelos Animales de Enfermedad , Femenino , Inflamación/etiología , Inflamación/patología , Mesocricetus , Mucosa Bucal/metabolismo , Mucosa Bucal/patología , Mucosa Bucal/efectos de la radiación , Mucositis/etiología , Mucositis/patologíaRESUMEN
Colloidal clay in water suspensions are known to exhibit a multitude of bulk phases depending on initial colloidal concentration and ionic strength, and examples of this include repulsive Wigner colloidal glasses at low ionic strength and attractive gels at higher ionic strength due to screened electrostatic forces by the electrolyte. From confocal Raman microscopy combined with elasticity measurements, we infer that clay trapped at quasi two-dimensional interfaces between oil and water also exhibit confined glass-like or gel-like states. The results can be important for the preparation of particles stabilized colloidal emulsions or colloidal capsules, and a better understanding of this phenomenon may lead to new emulsion or encapsulation technologies.
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Intraductal papillary mucinous neoplasm (IPMN), the most common pancreatic cystic neoplasm, is known to progress to invasive ductal adenocarcinoma. IPMNs commonly harbor activating somatic mutations in GNAS and KRAS, primarily GNAS(R201H) and KRAS(G12D). GNAS encodes the stimulatory G-protein α subunit (Gsα) that mediates a stimulatory signal to adenylyl cyclase to produce cyclic adenosine monophosphate (cAMP), subsequently activating cAMP-dependent protein kinase A. The GNAS(R201H) mutation results in constitutive activation of Gsα. To study the potential role of GNAS in pancreatic tumorigenesis in vivo, we generated lines of transgenic mice in which the transgene consisted of Lox-STOP-Lox (LSL)-GNAS(R201H) under the control of the CAG promoter (Tg(CAG-LSL-GNAS)). These mice were crossed with pancreatic transcription factor 1a (Ptf1a)-Cre mice (Ptf1a(Cre/+)), generating Tg(CAG-LSL-GNAS);Ptf1a(Cre/+) mice. This mouse line showed elevated cAMP levels, small dilated tubular complex formation, loss of acinar cells and fibrosis in the pancreas; however, no macroscopic tumorigenesis was apparent by 2 months of age. We then crossed Tg(CAG-LSL-GNAS);Ptf1a(Cre/+) mice with LSL-Kras(G12D) mice, generating Tg(CAG-LSL-GNAS);LSL-Kras(G12D);Ptf1a(Cre/+) mice. We used these mice to investigate a possible cooperative effect of GNAS(R201H) and Kras(G12D) in pancreatic tumorigenesis. Within 5 weeks, Tg(CAG-LSL-GNAS);LSL-Kras(G12D);Ptf1a(Cre/+) mice developed a cystic tumor consisting of marked dilated ducts lined with papillary dysplastic epithelia in the pancreas, which closely mimicked the human IPMN. Our data strongly suggest that activating mutations in GNAS and Kras cooperatively promote murine pancreatic tumorigenesis, which recapitulates IPMN. Our mouse model may serve as a unique in vivo platform to find biomarkers and effective drugs for diseases associated with GNAS mutations.
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Carcinogénesis/genética , Carcinoma Ductal Pancreático/patología , Cromograninas/genética , Subunidades alfa de la Proteína de Unión al GTP Gs/genética , Mutación , Neoplasias Pancreáticas/patología , Proteínas Proto-Oncogénicas p21(ras)/genética , Animales , Femenino , Humanos , Masculino , Ratones , Neoplasias Pancreáticas/genéticaRESUMEN
Far-upstream element-binding protein-interacting repressor (FIR) is a transcription factor that inhibits c-Myc expression and has been shown to have antitumor effects in some malignancies. Here, we evaluated the antitumor effects of FIR using fusion gene-deleted Sendai virus (SeV/ΔF) as a nontransmissible vector against head and neck squamous cell carcinoma (HNSCC). Using in vitro and in vivo xenograft mouse models, we observed efficient expression of green fluorescent protein (GFP) following transduction with the SeV/ΔF vector encoding GFP (GFP-SeV/ΔF) into HNSCC cells. In vitro and in vivo studies revealed that administration of the FIR-encoded SeV/ΔF (FIR-SeV/ΔF) vector exerted significant antitumor effects, suppressed c-Myc expression and induced apoptosis in HNSCC. Additionally, the antitumor effects of FIR or the expression of GFP following administration of the FIR- or GFP-SeV/ΔF vector, respectively, were dependent on the multiplicity of infection or titer. Furthermore, the SeV/ΔF vector itself had no cytotoxic effects. Therefore, the SeV/ΔF vector may be safe and useful for the treatment of HNSCC, allowing for high-titer SeV/ΔF vector administration for anticancer gene therapy. In addition, SeV/ΔF vector-mediated FIR gene therapy demonstrated effective tumor suppression in HNSCC, suggesting that this therapy may have the potential for clinical use as a novel strategy for HNSCC treatment.
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Factores de Intercambio de Guanina Nucleótido/metabolismo , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/terapia , Virus Sendai/metabolismo , Animales , Línea Celular , Femenino , Técnicas de Transferencia de Gen , Terapia Genética , Vectores Genéticos , Neoplasias de Cabeza y Cuello/genética , Xenoinjertos , Humanos , Ratones , Trasplante de Neoplasias , Proteínas Proto-Oncogénicas c-myc/metabolismoRESUMEN
As CBCT is widely used in dental and maxillofacial imaging, it is important for users as well as referring practitioners to understand the basic concepts of this imaging modality. This review covers the technical aspects of each part of the CBCT imaging chain. First, an overview is given of the hardware of a CBCT device. The principles of cone beam image acquisition and image reconstruction are described. Optimization of imaging protocols in CBCT is briefly discussed. Finally, basic and advanced visualization methods are illustrated. Certain topics in these review are applicable to all types of radiographic imaging (e.g. the principle and properties of an X-ray tube), others are specific for dental CBCT imaging (e.g. advanced visualization techniques).
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Tomografía Computarizada de Haz Cónico/métodos , Radiografía Dental/métodos , Tecnología Radiológica/métodos , Artefactos , Tomografía Computarizada de Haz Cónico/instrumentación , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Dosis de Radiación , Intensificación de Imagen Radiográfica/métodos , Radiografía Dental/instrumentación , Rayos XRESUMEN
OBJECTIVES: The aim of this study was to analyse the position and relationship of juxta-apical radiolucency (JAR) to the mandibular canal and buccal and/or lingual cortical plates using cone beam CT (CBCT). METHODS: A retrospective study was carried out to analyse the JAR on CBCT for 27 patients. These findings were compared with 27 age- and sex-matched patients without the presence of JAR, which acted as the control group. The CBCT images were analysed according to a checklist, to evaluate the position of the JAR and its relationship to the mandibular canal. Then, any thinning or perforation of either the buccal or lingual cortical plate due to JAR was noted, and a classification to quantify the thinning of cortical plates was proposed. The findings in the two groups were analysed using a paired comparison by McNemar test. RESULTS: A statistical increased thinning of cortical plates was seen in the JAR group compared with the control group, and most of the cases were in the J3 group. None of the patients in either the JAR or the control group showed perforation of the buccal and/or lingual cortical plate on CBCT images. CONCLUSIONS: A classification to quantify the thinning of cortical plates was proposed, which may be used for objective evaluation of the thinning of the cortical plates in future studies. The present study gives an insight into the relationship of the juxta-apical area with the mandibular canal and cortical plates in the mandible using CBCT.
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Tomografía Computarizada de Haz Cónico/métodos , Mandíbula/diagnóstico por imagen , Tercer Molar/diagnóstico por imagen , Ápice del Diente/diagnóstico por imagen , Adulto , Estudios de Casos y Controles , Lista de Verificación , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Estudios Retrospectivos , Raíz del Diente/diagnóstico por imagen , Diente Impactado/diagnóstico por imagenRESUMEN
OBJECTIVES: The SEDENTEXCT Project proposed quality assurance (QA) methods and introduced a QA image quality phantom. A new prototype was recently introduced that may be improved according to previous reports. The purpose of this study is to evaluate image quality in various protocols of three cone beam CT (CBCT) machines using the proposed QA phantom. METHODS: Using three CBCT machines, nine image quality parameters, including image homogeneity (noise), uniformity, geometrical distortion, pixel intensity value, contrast resolution, spatial resolution [line pair (LP) chart, point spread function (PSF) and modulation transfer function (MTF)] and metal artefacts, were evaluated using a QA phantom proposed by SEDENTEXCT. Exposure parameters, slice thickness and field of view position changed variously, and the number of total protocols was 22. RESULTS: Many protocols showed a uniform gray value distribution except in the minimum slice thickness image acquired using 3D Accuitomo 80 (Morita, Kyoto, Japan) and Veraviewepocs 3Df (Morita). Noise levels differed among the protocols. There was no geometric distortion, and the pixel intensity values were correlated with the CT value. Low contrast resolution differed among the protocols, but high contrast resolution performed well in all. Many protocols showed that the maximum line pair was larger than 1 LP mm(-1) but smaller than 3 LP mm(-1). PSF and MTF did not correlate well with the pixel size. The measured metal artefact areas varied for each device. CONCLUSIONS: We studied the image quality of three CBCT machines using the SEDENTEXCT phantom. Image quality varied with exposure protocols and machines.
Asunto(s)
Tomografía Computarizada de Haz Cónico/instrumentación , Fantasmas de Imagen , Intensificación de Imagen Radiográfica/normas , Aluminio/química , Artefactos , Tomografía Computarizada de Haz Cónico/normas , Diseño de Equipo , Humanos , Procesamiento de Imagen Asistido por Computador/normas , Imagenología Tridimensional/normas , Polietileno/química , Polimetil Metacrilato/química , Politetrafluoroetileno/química , Garantía de la Calidad de Atención de Salud/normas , Dosis de Radiación , Magnificación Radiográfica , Resinas Sintéticas/química , Titanio/química , Tomógrafos Computarizados por Rayos X/normasRESUMEN
BACKGROUND: Delirium and dementia are highly interrelated. However, few comprehensive epidemiological studies have examined this altered state of consciousness superimposed on dementia. We investigated the frequency of delirium in patients with dementia, its prevalence in patients with each dementia type, and its association with cerebrovascular disease (CVD) in patients with neurodegenerative dementias. METHODS: We studied 261 consecutive outpatients in the memory clinic of a psychiatric hospital between April 2010 and September 2011. All patients underwent routine laboratory tests and computed tomography (CT), and their Mini-Mental State Examination, Neuropsychiatric Inventory (NPI), Physical Self-Maintenance Scale (PSMS), and Delirium Rating Scale - Revised 98 scores were recorded. The diagnosis of delirium was based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision. CVD was detected by CT. RESULTS: Among the 206 patients with dementia, delirium was present in 40 (19.4%). The proportion of patients who experienced episodes of delirium was 14.7% in the Alzheimer's disease, 34.4% in the vascular dementia, 31.8% in the dementia with Lewy bodies, and none in frontotemporal lobar degeneration. Delirium was frequently observed in patients with dementia and CVD. The NPI total and agitation subscale scores were significantly higher in dementia patients with delirium than in those without delirium. PSMS scores were significantly lower for patients with delirium than for patients without delirium. CONCLUSIONS: The frequency of delirium varies with each dementia type. In addition, delirium decreases activities of daily living, exaggerates behavioral and psychological symptoms dementia, and is associated with CVD in patients with neurodegenerative dementias.