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BACKGROUND: Hand-arm vibration (HAV) is a risk factor for carpal tunnel syndrome (CTS) and ulnar neuropathy at the elbow (UNE). It is unclear how ergonomic factors influence the relationship between HAV exposure and CTS and UNE. AIMS: We aimed to assess the relationship between cumulative HAV exposure and CTS and UNE in workers exposed to HAV from two tools with different ergonomic profiles. METHODS: We performed nerve conduction studies (NCSs) of the sensory and motor median and ulnar nerves and recorded symptoms indicating CTS and UNE in workers exposed to HAV from impact wrenches or from rock drills. Exposure was measured as cumulative lifetime exposure. We used linear regression adjusted for age and body mass index to assess linear relationships. RESULTS: Sixty-five workers participated (33 rock drill and 32 impact wrench operators). We found inverse linear associations between cumulative HAV exposure and median nerve sensory conduction velocity in impact wrench operators and ulnar nerve motor conduction velocity in rock drill operators (beta of 0.63 and 0.75). Based on NCS findings and symptoms, seven impact wrench operators had CTS and one UNE, and four rock drill operators had CTS and six UNE. CONCLUSIONS: Our findings indicate that ergonomic factors influence the development of CTS and UNE under HAV exposure. The ergonomic profile seems to influence which type of neuropathy workers exposed to HAV will develop. Design of occupational exposure guidelines and future studies should be based on ergonomic profile and exposure characteristics for different tools and not merely HAV.
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Síndrome del Túnel Carpiano , Enfermedades del Sistema Nervioso Periférico , Humanos , Vibración/efectos adversos , Conducción Nerviosa/fisiología , Enfermedades del Sistema Nervioso Periférico/etiología , Síndrome del Túnel Carpiano/etiología , Síndrome del Túnel Carpiano/diagnóstico , ErgonomíaRESUMEN
The objective of this study was to determine the natural concentrations of Hg and Se in 45 representative soil profiles from the Cerrado biome in central Brazil, and to correlate their concentrations with soil chemical and physical characteristics. The study area was composed of three sub-regions: Goiás, Northwest of Minas Gerais, and Minas Gerais Triangle. Selenium and Hg concentrations were determined by acid digestion and atomic absorption spectroscopy. Data were subjected to analysis of variance on the means of the Hg and Se variables within each soil class at two depths, followed by multivariate statistical methods. The Hg concentrations ranged from 15 to 182⯵gâ¯kg-1 and the Se concentrations ranged from 22 to 72⯵gâ¯kg-1. The soil characteristics that most contributed to Hg concentrations in the soils, according to principal component analysis, were Fe2O3, FeO, TiO2, pH, P2O5, and effective CEC. In general, the soils of the Cerrado biome have deficient Se concentrations. The Humic Rhodic Acrustoxes have Hg concentrations above the prevention reference value for soils of Minas Gerais.
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Mercurio/análisis , Selenio/análisis , Suelo/química , Brasil , Monitoreo del Ambiente/métodos , Compuestos Férricos/análisis , Análisis de Componente Principal , Espectrofotometría AtómicaRESUMEN
OBJECTIVES: The objective of this study was to compare the performance of metal oxide semiconductor field-effect transistor (MOSFET) technology dosemeters with thermoluminescent dosemeters (TLDs) (TLD 100; Thermo Fisher Scientific, Waltham, MA) in the maxillofacial area. METHODS: Organ and effective dose measurements were performed using 40 TLD and 20 MOSFET dosemeters that were alternately placed in 20 different locations in 1 anthropomorphic RANDO(®) head phantom (the Phantom Laboratory, Salem, NY). The phantom was exposed to four different CBCT default maxillofacial protocols using small (4 × 5 cm) to full face (20 × 17 cm) fields of view (FOVs). RESULTS: The TLD effective doses ranged between 7.0 and 158.0 µSv and the MOSFET doses between 6.1 and 175.0 µSv. The MOSFET and TLD effective doses acquired using four different (FOV) protocols were as follows: face maxillofacial (FOV 20 × 17 cm) (MOSFET, 83.4 µSv; TLD, 87.6 µSv; -5%); teeth, upper jaw (FOV, 8.5 × 5.0 cm) (MOSFET, 6.1 µSv; TLD, 7.0 µSv; -14%); tooth, mandible and left molar (FOV, 4 × 5 cm) (MOSFET, 10.3 µSv; TLD, 12.3 µSv; -16%) and teeth, both jaws (FOV, 10 × 10 cm) (MOSFET, 175 µSv; TLD, 158 µSv; +11%). The largest variation in organ and effective dose was recorded in the small FOV protocols. CONCLUSIONS: Taking into account the uncertainties of both measurement methods and the results of the statistical analysis, the effective doses acquired using MOSFET dosemeters were found to be in good agreement with those obtained using TLD dosemeters. The MOSFET dosemeters constitute a feasible alternative for TLDs for the effective dose assessment of CBCT devices in the maxillofacial region.
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Cone beam CT (CBCT) is a relatively new imaging modality, which is now widely available to dentists for examining hard tissues in the dental and maxillofacial regions. CBCT gives a three-dimensional depiction of anatomy and pathology, which is similar to medical CT and uses doses generally higher than those used in conventional dental imaging. The European Academy of DentoMaxilloFacial Radiology recognizes that dentists receive training in two-dimensional dental imaging as undergraduates, but most of them have received little or no training in the application and interpretation of cross-sectional three-dimensional imaging. This document identifies the roles of dentists involved in the use of CBCT, examines the training requirements for the justification, acquisition and interpretation of CBCT imaging and makes recommendations for further training of dentists in Europe who intend to be involved in any aspect of CBCT imaging. Two levels of training are recognized. Level 1 is intended to train dentists who prescribe CBCT imaging, such that they may request appropriately and understand the resultant reported images. Level 2 is intended to train to a more advanced level and covers the understanding and skills needed to justify, carry out and interpret a CBCT examination. These recommendations are not intended to create specialists in CBCT imaging but to offer guidance on the training of all dentists to enable the safe use of CBCT in the dentoalveolar region.
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Tomografía Computarizada de Haz Cónico/métodos , Educación en Odontología , Radiología/educación , Competencia Clínica , Educación Continua en Odontología , Europa (Continente) , Odontología General/educación , Humanos , Imagenología Tridimensional/métodos , Rol Profesional , Dosis de RadiaciónRESUMEN
OBJECTIVES: This study investigated the absorbed doses in a full anthropomorphic body phantom from two different panoramic radiography devices, performing protocols with and without applying a lead apron. METHODS: A RANDO(®) full body phantom (Alderson Research Laboratories Inc., Stamford, CT) was equipped with 110 thermoluminescent dosemeters at 55 different sites and set up in two different panoramic radiography devices [SCANORA(®) three-dimensional (3D) (SOREDEX, Tuusula, Finland) and ProMax(®) 3D (Planmeca, Helsinki, Finland)] and exposed. Two different protocols were performed in the two devices. The first protocol was performed without any lead shielding, whereas the phantom was equipped with a standard adult lead apron for the second protocol. RESULTS: A two-tailed paired samples t-test for the SCANORA 3D revealed that there is no difference between the protocol using lead apron shielding (m = 87.99, s = 102.98) and the protocol without shielding (m = 87.34, s = 107.49), t(54) = -0.313, p > 0.05. The same test for the ProMax 3D showed that there is also no difference between the protocol using shielding (m = 106.48, s = 117.38) and the protocol without shielding (m = 107.75, s = 114,36), t(54) = 0.938, p > 0.05. CONCLUSIONS: In conclusion, the results of this study showed no statistically significant differences between a panoramic radiography with or without the use of lead apron shielding.
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Radiografía Panorámica , Dosimetría Termoluminiscente , Humanos , Fantasmas de Imagen , Dosis de Radiación , Protección Radiológica/instrumentación , Radiografía Dental Digital/instrumentación , Dosimetría Termoluminiscente/instrumentaciónRESUMEN
OBJECTIVES: Evaluation and reduction of dose are important issues. Since cone beam CT (CBCT) has been established now not just in dentistry, the number of acquired examinations continues to rise. Unfortunately, it is very difficult to compare the doses of available devices on the market owing to different exposition parameters, volumes and geometries. The aim of this study was to evaluate the spans of effective doses (EDs) of ten different CBCT devices. METHODS: 48 thermoluminescent dosemeters were placed in 24 sites in a RANDO(®) head phantom. Protocols with lowest exposition parameters and protocols with highest exposition parameters were performed for each of the ten devices. The ED was calculated from the measured energy doses according to the International Commission on Radiological Protection 2007 recommendations for each protocol and device, and the statistical values were evaluated afterwards. RESULTS: The calculation of the ED resulted in values between 17.2 µSv and 396 µSv for the ten devices. The mean values for protocols with lowest and highest exposition parameters were 31.6 µSv and 209 µSv, respectively. CONCLUSIONS: It was not the aim of this study to evaluate the image quality depending on different exposition parameters but to define the spans of EDs in which different CBCT devices work. There is a wide span of ED for different CBCT devices depending on the selected exposition parameters, required spatial resolution and many other factors.
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Tomografía Computarizada de Haz Cónico/instrumentación , Dosis de Radiación , Calibración , Vértebras Cervicales/efectos de la radiación , Mejilla/efectos de la radiación , Tomografía Computarizada de Haz Cónico/métodos , Esófago/efectos de la radiación , Cabeza/efectos de la radiación , Humanos , Cristalino/efectos de la radiación , Mandíbula/efectos de la radiación , Mesencéfalo/efectos de la radiación , Órbita/efectos de la radiación , Glándula Parótida , Fantasmas de Imagen , Hipófisis/efectos de la radiación , Base del Cráneo/efectos de la radiación , Glándula Sublingual/efectos de la radiación , Glándula Submandibular/efectos de la radiación , Dosimetría Termoluminiscente/instrumentación , Glándula Tiroides/efectos de la radiaciónRESUMEN
OBJECTIVES: This study investigated the absorbed doses in a full anthropomorphic body phantom from two different panoramic radiography devices, performing protocols with and without applying a lead apron. METHODS: A RANDO® full body phantom (Alderson Research Laboratories Inc., Stamford, CT) was equipped with 110 thermoluminescent dosemeters at 55 different sites and set up in two different panoramic radiography devices [SCANORA® three-dimensional (3D) (SOREDEX, Tuusula, Finland) and ProMax® 3D (Planmeca, Helsinki, Finland)] and exposed. Two different protocols were performed in the two devices. The first protocol was performed without any lead shielding, whereas the phantom was equipped with a standard adult lead apron for the second protocol. RESULTS: A two-tailed paired samples t-test for the SCANORA 3D revealed that there is no difference between the protocol using lead apron shielding (m = 87.99, s = 102.98) and the protocol without shielding (m = 87.34, s = 107.49), t(54) = −0.313, p > 0.05. The same test for the ProMax 3D showed that there is also no difference between the protocol using shielding (m = 106.48, s = 117.38) and the protocol without shielding (m = 107.75, s = 114,36), t(54) = 0.938, p > 0.05. CONCLUSIONS: In conclusion, the results of this study showed no statistically significant differences between a panoramic radiography with or without the use of lead apron shielding.
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Dosis de Radiación , Protección Radiológica/instrumentación , Radiografía Panorámica/instrumentación , Humanos , Imagenología Tridimensional/instrumentación , Fantasmas de Imagen , Radiografía Dental Digital/instrumentación , Radiografía Panorámica/métodos , Dosimetría Termoluminiscente/instrumentaciónRESUMEN
OBJECTIVES: The aim of this study was to examine the relationship between the roof of the glenoid fossa (RGF) thickness and condyle morphology and the influence of the number of remaining teeth and age. METHODS: Cone beam CT data sets from 77 asymptomatic European patients were analysed retrospectively in this study. The thinnest area of RGF was identified among the sagittal and coronal slices on a computer screen; distance measurement software was used to measure the thickness. Moreover, we applied a free digital imaging and communications in medicine viewer for classification of condyle head type. It was also used to analyse any relation between RGF thickness and the number of remaining teeth. We performed a correlation analysis for RGF, age and missing teeth. Finally, we investigated combining sagittal condyle morphological characterization with coronal condyle morphology in relation to the number of joints and RGF thickness. RESULTS: The Kruskal-Wallis test revealed no significant differences in RGF thickness among any of the coronal condyle head morphology groups (p > 0.05). There were significant differences in the thinnest part of RGF in relation to the sagittal plane for condyle morphological characterization, because we observed increased RGF thickness in joints with osteoarthritis features (p < 0.05). There is a non-significant correlation between the thinnest part of the RGF and the number of remaining teeth (p > 0.05). CONCLUSIONS: We found that the RGF thickness is unaffected by the coronal condyle head morphology and the number of remaining teeth. Osteoarthritic changes (sagittal condyle morphology) have an effect on RGF.
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Cóndilo Mandibular/patología , Osteoartritis/patología , Hueso Temporal/patología , Articulación Temporomandibular/patología , Pérdida de Diente/fisiopatología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Niño , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Modelos Lineales , Masculino , Cóndilo Mandibular/diagnóstico por imagen , Persona de Mediana Edad , Osteoartritis/diagnóstico por imagen , Estudios Retrospectivos , Estadísticas no Paramétricas , Hueso Temporal/diagnóstico por imagen , Articulación Temporomandibular/diagnóstico por imagen , Trastornos de la Articulación Temporomandibular/diagnóstico por imagen , Trastornos de la Articulación Temporomandibular/patología , Adulto JovenRESUMEN
PURPOSE: To generate hybrid VMAT-IMRT treatment plans by utilizing an IMRT beam-angle-optimality (BAO) search under a commercially available TPS without the aid of custom optimization software or high performance computing. METHODS: The high dose modulation provided by IMRT beams can be exploited to improve the quality of VMAT treatments. To achieve this, a VMAT treatment was created where the gantry pauses at predetermined angles to deliver IMRT segments. To determine IMRT BAO, an IMRT plan ('poly-IMRT') was made with many beams (>30) equally spaced around the patient. For practical reasons and to reduce the total time to approximately 1 hour, BAO was approximated by removing one beam out of the set and noting the new objective score. Determining this'score penalty' for each of the beams serves as a proxy for true BAO. The hybrid plan was created by combining the VMAT arc with a user-determined number of top-ranked beams from the poly-IMRT set. The BAO from this approach was compared with a more rigorous method ('VMAT+1'), in which a VMAT plan was optimized with 1 IMRT beam at various angles, allowing a direct determination of objective score versus gantry angle. The overall hybrid planning process was demonstrated by creating separate plans for a SBRT lung patient, with dose normalized to the limiting maximum aorta dose. RESULTS: Large score penalties from poly-IMRT coincided with large score benefits from VMAT+1, indicating both methods identified the same optimal beams. The VMAT, IMRT, and hybrid plans delivered the prescription dose to 84.3%, 85.6% and 87.7% of the PTV and had homogeneity indices of 1.38, 1.41, and 1.32 respectively. Normal tissue doses were within 0.5%. CONCLUSION: The presented method can create hybrid VMAT-IMRT plans which combine delivery efficiency with improved target coverage. The planning process takes about an hour using a standard TPS.
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Few data exist regarding the human papillomavirus (HPV) types in penile warts (PW) of HIV-infected men in Africa. Nurses collected penile swabs for HPV typing from 74 HIV-positive men with PW. HPV genotyping was performed using the Roche Linear Array Test. Analysis was performed on data relating to 74 samples. The mean age of the men was 36.0 years and 78.5% (51/65) were uncircumcised. Of the 73/74 validated results, all tested positive for HPV; 42.5% (31/73) and 32.9% (24/73) had HPV types 6 and 11, respectively. 84.9% of men tested positive for any oncogenic type: 20/73 (27.4%) were positive for type 16, 11/73 (15.1%) were positive for type 18 and 8/73 (11.0%) men had both types. Our study shows a high prevalence (68.5%) of HPV type 6 and/or 11 in this male population with PW. Given the poor availability of treatment, a quadrivalent vaccine for men may have significant benefit.
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Condiloma Acuminado/epidemiología , Infecciones por VIH/complicaciones , Papillomaviridae/clasificación , Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/epidemiología , Enfermedades del Pene/epidemiología , Adulto , Condiloma Acuminado/virología , Genotipo , Humanos , Masculino , Tipificación Molecular , Infecciones por Papillomavirus/virología , Enfermedades del Pene/virología , Prevalencia , Sudáfrica/epidemiologíaRESUMEN
UNLABELLED: Osteoporosis is a major public health problem worldwide. Its significance in the fields of traumatology and implantology of the maxillofacial area requires investigation. A large animal model was used to assess bone loss in the lumbar spine and mandible. INTRODUCTION: Osteoporosis is a prevalent disease characterized by low bone mass and microarchitectural deterioration of bone tissue. Osteoporosis-related fractures represent a major public health burden. The presence and relevance of osteoporosis in the maxillofacial area remain controversial. Research in humans is limited by difficulties in finding large homogenous study groups and, due to ethical considerations, numerous animal models have been used in osteoporosis research. The aim of this study was to assess a sheep model of generalized osteopenia for changes in the maxillofacial area. METHODS: Bone loss was induced in ten Merino sheep by ovariectomy, intramuscular administration of glucocorticoids, and a calcium-reduced diet. Five untreated animals served as controls. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry at the lumbar spine at baseline and after 1, 3, 6, 9, and 12 months. Lumbar and mandibular bone biopsies were obtained and analyzed with microcomputed tomography. RESULTS: Lumbar BMD decreased progressively in the intervention group and was most significantly low after 6 months (p < 0.001). Lumbar trabecular bone showed a significant decrease in bone volume (BV)/tissue volume (TV; p < 0.05) in the inducted group. Significant changes were found in both analyzed mandibular regions for BV/TV (p < 0.05). Regional variations were found for other parameters in the mandible. The cortical width was substantially reduced in the intervention group (p < 0.001). CONCLUSIONS: Microstructural changes occurring in sheep as a result of induction seem to have a generalized nature. This sheep model meets the criteria for further investigation in the maxillofacial area.
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Enfermedades Óseas Metabólicas/etiología , Modelos Animales de Enfermedad , Mandíbula/fisiopatología , Animales , Enfermedades Óseas Metabólicas/diagnóstico por imagen , Enfermedades Óseas Metabólicas/fisiopatología , Calcio de la Dieta/administración & dosificación , Dexametasona , Femenino , Glucocorticoides , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/fisiopatología , Mandíbula/diagnóstico por imagen , Ovariectomía , Ovinos , Microtomografía por Rayos X/métodosRESUMEN
AIM: Modified quantitative computed tomography is a method used to predict bone quality and quantify the bone mass of the jaw. The aim of this study was to determine whether bone quantity or quality was detected by cone beam computed tomography (CBCT) combined with image analysis. MATERIALS AND PROCEDURES: Different measurements recorded on two phantoms (Siemens phantom, Comac phantom) were evaluated on images taken with the Somatom VolumeZoom (Siemens Medical Solutions, Erlangen, Germany) and the NewTom 9000 (NIM s.r.l., Verona, Italy) in order to calculate a calibration curve. The spatial relationships of six sample cylinders and the repositioning from four pig skull halves relative to adjacent defined anatomical structures were assessed by means of three-dimensional visualization software. RESULTS: The calibration curves for computer tomography (CT) and cone beam computer tomography (CBCT) using the Siemens phantom showed linear correlation in both modalities between the Hounsfield Units (HU) and bone morphology. A correction factor for CBCT was calculated. Exact information about the micromorphology of the bone cylinders was only available using of micro computer tomography. CONCLUSION: Cone-beam computer tomography is a suitable choice for analysing bone mass, but, it does not give any information about bone quality.
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Densidad Ósea , Tomografía Computarizada de Haz Cónico , Procesamiento de Imagen Asistido por Computador , Mandíbula/diagnóstico por imagen , Pérdida de Hueso Alveolar/diagnóstico por imagen , Animales , Cefalometría , Fantasmas de Imagen , Porcinos , Tomógrafos Computarizados por Rayos X , Tomografía Computarizada por Rayos X , Microtomografía por Rayos XRESUMEN
The objective of the present study was to determine the clinical success of Cerec 3D inlays over a period of three years. Within the scope of the restorative dentistry course II, 62 Cerec ceramic inlays were inserted with Dual Cement (Ivoclar Vivadent) in combination with the Syntac Classic system (Ivoclar Vivadent). Regular follow-up examinations and assessments were performed by reference to modified US Public Health Service (USPHS) criteria. The baseline examination was performed one week after insertion and further follow-up examinations were performed at 6-month intervals. The survival rate of the Cerec 3D inlays was 95% after three years. Three inlays were assessed as failures because of loss of sensitivity, restoration fracture, and marginal gap formation. Six patients initially suffered from postoperative hypersensitivity, which vanished by the first follow-up examination. The results of this study show that dentists with little experience are able to achieve good clinical results and long-term success after short theoretical as well as practical training and an introductory course in the Cerec method.
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Cerámica , Diseño Asistido por Computadora , Porcelana Dental , Incrustaciones , Adulto , Diente Premolar , Humanos , Persona de Mediana Edad , Diente Molar , Adulto JovenRESUMEN
The authors report a case of navigation-guided tumour ablation of a high-grade epithelial-myoepithelial carcinoma of the right parotid gland extending to the skull base. Immediate functional reconstruction of the mandible with a prosthetic temporomandibular joint and facial nerve was performed. Postoperative follow-up showed no evidence of local tumour recurrence or distant metastasis with satisfactory temporomandibular and facial nerve function.
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Carcinoma/cirugía , Neoplasias de la Parótida/cirugía , Procedimientos de Cirugía Plástica/métodos , Cirugía Asistida por Computador , Carcinoma/secundario , Quimioterapia Adyuvante , Nervio Facial/cirugía , Estudios de Seguimiento , Humanos , Imagenología Tridimensional , Prótesis Articulares , Metástasis Linfática/patología , Imagen por Resonancia Magnética , Masculino , Mandíbula/cirugía , Cóndilo Mandibular/cirugía , Persona de Mediana Edad , Disección del Cuello , Invasividad Neoplásica , Estadificación de Neoplasias , Radioterapia Adyuvante , Base del Cráneo/patología , Articulación Temporomandibular/cirugía , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: To report the clinical, histopathological and immunohistochemical findings of two novel mutations within the TGFBI gene. METHODS: The genotype of 41 affected members of 16 families and nine sporadic cases was investigated by direct sequencing of the TGFBI gene. Clinical, histological and immunohistochemical characteristics of corneal opacification were reported and compared with the coding region changes in the TGFBI gene. RESULTS: A novel mutation Leu509Pro was detected in one family with a geographic pattern-like clinical phenotype. Histopathologically we found amyloid together with non-amyloid deposits and immunohistochemical staining of Keratoepithelin (KE) KE2 and KE15 antibodies. In two families and one sporadic case the novel mutation Gly623Arg with a late-onset, map-like corneal dystrophy was identified. Here amyloid and immunohistochemical staining of only KE2 antibodies occurred. Further, five already known mutations are reported: Arg124Cys Arg555Trp Arg124His His626Arg, Ala546Asp in 13 families and five sporadic cases of German origin. The underlying gene defect within the TBFBI gene was not identified in any of the four probands with Thiel-Behnke corneal dystrophy. CONCLUSIONS: The two novel mutations within the TGFBI gene add another two phenotypes with atypical immunohistochemical and histopathological features to those so far reported.
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Distrofias Hereditarias de la Córnea/genética , Proteínas de la Matriz Extracelular/genética , Predisposición Genética a la Enfermedad/genética , Mutación/genética , Factor de Crecimiento Transformador beta/genética , Agudeza Visual/genética , Adulto , Factores de Edad , Distrofias Hereditarias de la Córnea/patología , Análisis Mutacional de ADN , Femenino , Humanos , Masculino , Linaje , Fenotipo , Adulto JovenRESUMEN
AIMS/HYPOTHESIS: In a previous study, we demonstrated that a creatine kinase (CK) modulates K(ATP) channel activity in pancreatic beta cells. To explore phosphotransfer signalling pathways in more detail, we examined whether K(ATP) channel regulation in beta cells is determined by a metabolic interaction between adenylate kinase (AK) and CK. METHODS: Single channel activity was measured with the patch-clamp technique in the inside-out (i/o) and open-cell attached (oca) configuration. RESULTS: The ATP sensitivity of K(ATP) channels was higher in i/o patches than in permeabilised beta cells (oca). One reason for this observation could be that the local ATP:ADP ratio in the proximity of the channels is determined by factors not active in i/o patches. AMP (0.1 mmol/l) clearly increased open channel probability in the presence of ATP (0.125 mmol/l) in permeabilised cells but not in excised patches. This suggests that AK-catalysed ADP production in the vicinity of the channels is involved in K(ATP) channel regulation. The observation that the stimulatory effect of AMP on K(ATP) channels was prevented by the AK inhibitor P (1),P (5)-di(adenosine-5')pentaphosphate (Ap(5)A; 20 micromol/l) and abolished in the presence of the non-metabolisable ATP analogue adenosine 5'-(beta,gamma-imido)triphosphate tetralithium salt (AMP-PNP; 0.12 mmol/l) strengthens this idea. In beta cells from AK1 knockout mice, the effect of AMP was less pronounced, though not completely suppressed. The increase in K(ATP) channel activity induced by AMP in the presence of ATP was outweighed by phosphocreatine (1 mmol/l). We suggest that this is due to an elevation of the ATP concentration by CK. CONCLUSIONS/INTERPRETATION: We propose that phosphotransfer events mediated by AK and CK play an important role in determining the effective concentrations of ATP and ADP in the microenvironment of pancreatic beta cell K(ATP) channels. Thus, these enzymes determine the open probability of K(ATP) channels and eventually the actual rate of insulin secretion.
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Adenilato Quinasa/metabolismo , Células Secretoras de Insulina/fisiología , Canales KATP/fisiología , Adenosina Monofosfato/farmacología , Adenosina Trifosfato/fisiología , Animales , Electrofisiología/métodos , Células Secretoras de Insulina/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Modelos Biológicos , Técnicas de Placa-ClampAsunto(s)
Trastornos de los Cromosomas/complicaciones , Trastornos de los Cromosomas/genética , Cromosomas Humanos Par 22/genética , Anomalías del Ojo/complicaciones , Anomalías del Ojo/genética , Esquizofrenia/complicaciones , Esquizofrenia/genética , Adulto , Coloboma/genética , Anomalías Craneofaciales/genética , Femenino , Cardiopatías Congénitas/genética , Humanos , Discapacidad Intelectual/genética , Escalas de Valoración Psiquiátrica , Psicología del Esquizofrénico , SíndromeRESUMEN
Currently, methods of modern imaging are increasingly assuming a predominant position in diagnostics and therapy. Larger and larger amounts of sensitive data and information are generated, processed and--frequently with inadequate protection--transmitted through generally accessible networks. The Internet is used especially intensively as a medium for transporting digital data; at the same time, protection of sensitive data is frequently neglected to a high degree by medical professionals. The present contribution is therefore intended to provide an overview of currently valid standards and legal regulations, as well as suitable encoding methods relevant for the dental practice.
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Redes de Comunicación de Computadores , Seguridad Computacional , Confidencialidad/legislación & jurisprudencia , Registros Odontológicos , Correo Electrónico , Europa (Continente) , Control de Formularios y Registros , Humanos , Sistemas de Información Radiológica/normas , Programas InformáticosRESUMEN
The objective of this paper is to evaluate magnetic field interactions at 1.5 and 3 T for 20 orthodontic devices used for fixed orthodontic therapy. Twenty springs and auxiliary parts made from varying ferromagnetic alloys were tested for magnetic field interactions in the static magnetic field at 1.5 and 3 T. Magnetic translational force F(z) (in millinewtons) was evaluated by determining the deflection angle beta [American Society for Testing and Materials (ASTM standard test method)]. Magnetic-field-induced rotational force F(rot) was qualitatively determined using a five-point scale. beta was found to be >45 degrees in 13(15) devices at 1.5(3) T and translational force F(z) exceeded gravitational force F(g) on the particular object [F(z) 10.17-261.4 mN (10.72-566.4 mN) at 1.5(3) T]. F(z) was found to be up to 24.1(47.5)-fold higher than F(g) at 1.5(3) T. Corresponding to this, F(rot) on the objects was shown to be high at both field strengths (> or = +3). Three objects (at 1.5 T) and one object (at 3 T) showed deflection angles <45 degrees , but F(rot) was found to be > or = +3 at both field strengths. For the remaining objects, beta was below 45 degrees and torque measurements ranged from 0 to +2. Of 20 objects investigated for magnetic field interactions at 1.5(3) T, 13(15) were unsafe in magnetic resonance (MR), based on the ASTM criteria of F(z). The implications of these results for orthodontic patients undergoing MRI are discussed.