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1.
West Afr J Med ; 41(4): 414-420, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-39003513

RESUMO

BACKGROUND: Penile trauma is associated with debilitating complications. Apart from its sparse literature, contextually relevant evidence on aetiology and standardized severity grading, and its stratification by legal age are needed. This study aimed to describe the frequency, aetiology and injury severity grade of patients, and explore the association of specific factors by legal age. SUBJECTS, MATERIALS AND METHODS: A single-centre retrospective cross-sectional study was conducted in our centre. Male patients with penile trauma managed by urologists were included. Data on age, year of presentation, aetiology, penile injury extent and co-existing genitourethral injuries were obtained. Descriptive and inferential statistics were undertaken using SPSS and MedCalc. Pvalue < 0.05 was considered significant. RESULTS: Forty-two patient records were analyzed. The median age and interquartile range for legal minors and legal adults were 9.5 (5.0-14.8) years and 31.0 (22.5-41.0) years, and they constituted 28.6% (n=12) and 71.4% (n=30) of the study population respectively. Penile trauma was isolated in 26.2% (n=11) of the total population.Its annual frequency was below the median volume between 2001 and 2008 but shifted to a rate above the average level between 2017 and 2021. The rate of conveyor belt-related aetiology and high-grade trauma was 41.7% and 75.0% in legal minors while it was 26.1% and 53.3% respectively in legal adults. CONCLUSIONS: Grade IV trauma was the most predominant while conveyor belt injury was the most common cause of the injury. Albeit limitations of statistical comparison, the rate of conveyor belt injury and high-grade trauma was numerically high in legal minors.


CONTEXTE: Les traumatismes du pénis sont associés à des complications débilitantes. Outre la rareté de la littérature, des preuves contextuel l ement per tinentes sur l ' étiol ogie et l a classification standardisée de la gravité, ainsi que leur stratification par âge légal, sont nécessaires. Cette étude visait à décrire la fréquence, l'étiologie et le degré de gravité des blessures des patients, et à explorer l'association de facteurs spécifiques par âge légal. SUJETS, MATÉRIELS ET MÉTHODES: Une étude rétrospective transversale monocentrique a été réalisée dans notre centre. Les patients masculins ayant subi un traumatisme pénien pris en charge par des urologues ont été inclus. Les données sur l'âge, l'année de présentation, l'étiologie, l'étendue de la blessure pénienne et les blessures génito-urétrales coexistantes ont été obtenues. Des statistiques descriptives et inférentielles ont été réalisées à l'aide de SPSS et MedCalc. Une valeur de p < 0,05 a été considérée comme significative. RÉSULTATS: Quarante-deux dossiers de patients ont été analysés. L'âge médian et l'intervalle interquartile pour les mineurs légaux et les adultes légaux étaient de 9,5 (5,0-14,8) ans et 31,0 (22,5-41,0) ans, représentant respectivement 28,6 % (n=12) et 71,4 % (n=30) de la population étudiée. Le traumatisme pénien était isolé chez 26,2 % (n=11) de la population totale. Sa fréquence annuelle était inférieure au volume médian entre 2001 et 2008, mais a dépassé le niveau moyen entre 2017 et 2021. Le taux d'étiologie liée aux tapis roulants et de traumatismes graves était de 41,7 % et 75,0 % chez les mineurs légaux, contre 26,1 % et 53,3 % respectivement chez les adultes légaux. CONCLUSIONS: Le traumatisme de grade IV était le plus prédominant, tandis que les blessures causées par les tapis roulants étaient la cause la plus courante de lésion. Bien que limitées par des comparaisons statistiques, les taux de blessures par tapis roulant et de traumatismes graves étaient numériquement élevés chez les mineurs légaux. MOTS-CLÉS: Facteurs d'âge, Étiologie, Score de gravité des blessures, Pénis.


Assuntos
Pênis , Humanos , Masculino , Estudos Transversais , Estudos Retrospectivos , Pênis/lesões , Adulto , Adolescente , Criança , Adulto Jovem , Pré-Escolar , Escala de Gravidade do Ferimento , Fatores Etários
2.
J Chem Phys ; 158(1): 014108, 2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36610976

RESUMO

Weighted ensemble (WE) is an enhanced sampling method based on periodically replicating and pruning trajectories generated in parallel. WE has grown increasingly popular for computational biochemistry problems due, in part, to improved hardware and accessible software implementations. Algorithmic and analytical improvements have played an important role, and progress has accelerated in recent years. Here, we discuss and elaborate on the WE method from a mathematical perspective, highlighting recent results that enhance the computational efficiency. The mathematical theory reveals a new strategy for optimizing trajectory management that approaches the best possible variance while generalizing to systems of arbitrary dimension.


Assuntos
Algoritmos , Software
4.
Endocrinology ; 152(8): 3123-34, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21558312

RESUMO

A synthetic glucocorticoid receptor (GR) ligand with the efficacy of a glucocorticoid, but without the accompanying side effects, would meet an unmet medical need for the treatment of inflammatory diseases. It was hypothesized that a GR ligand that shifted helix 12 in a manner distinct from an agonist and an antagonist would confer a distinct GR conformation, resulting in differential gene expression and, ultimately, dissociation of antiinflammatory activity from side effects. A structural feature expected to interfere with helix 12 was incorporated into a nonsteroidal, tricyclic scaffold to create novel, high-affinity, and selective GR ligands that manifested a dual function in cellular assays, partial but robust agonist activity for inflammatory cytokine inhibition, and full antagonist activity for reporter gene activation. In contrast, analogs not likely to hinder helix 12 exhibited partial agonist activity for reporter gene activation. The requirement of full antagonist activity for substantial side effect dissociation was demonstrated in primary human preadipocytes, hepatocytes, and osteoblasts in which effects on adipogenesis, key genes involved in gluconeogenesis, and genes important for bone formation were examined, respectively. The dissociated GR ligands, despite lacking significant reporter gene activation, weakly recruit a limited number of coactivators such as peroxisomal proliferator-activated receptor-γ coactivator 1α. Transcriptional activation was sensitive to both peroxisomal proliferator-activated receptor-γ coactivator 1α and GR levels, providing a basis for cell-selective modulation of gene expression. The antiinflammatory activity of the dissociated ligands was further demonstrated in mouse models of inflammation. Together these results suggest that these ligands are promising candidates with robust antiinflammatory activity and likely dissociation against glucocorticoid-induced side effects.


Assuntos
Glucocorticoides/efeitos adversos , Receptores de Glucocorticoides/efeitos dos fármacos , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Animais , Anti-Inflamatórios/farmacologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Gluconeogênese/efeitos dos fármacos , Proteínas de Choque Térmico/fisiologia , Humanos , Camundongos , Mifepristona/farmacologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Receptores de Glucocorticoides/agonistas , Receptores de Glucocorticoides/antagonistas & inibidores , Fatores de Transcrição/fisiologia
5.
J Intellect Disabil Res ; 55(8): 777-89, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20561147

RESUMO

BACKGROUND: Planning for future care after the death of parental caregivers and adapting disability support systems to achieve the best possible quality of life for people with intellectual disability as they age have been important issues for more than two decades. This study examined perceptions held by family members, group home staff and organisational managers about the future of older residents and the decisions made that a move to residential aged care was necessary. METHODS: Grounded Dimensional Analysis was used to guide data collection and analysis by an interdisciplinary research team. Three sets of interviews over a period of 18 months were conducted with a family member, house supervisor and the programme manager for each of seventeen older group home residents in Victoria. For the eight people for whom it was decided a move was necessary and the six who eventually moved focussed questions were asked about the decision-making process. RESULTS: While plans for lifelong accommodation in a group home proved unfounded, key person succession plans were effective. However, decisions to move to a residential aged care facility where necessary were made in haste and seen as a fait accompli by involved family members. CONCLUSIONS: Although family members take seriously their mandate to oversee well-being of their older relative, they have little knowledge about their rights or avenues to safeguard untimely or inappropriate decisions being made by professionals.


Assuntos
Continuidade da Assistência ao Paciente , Tomada de Decisões , Lares para Grupos , Instituição de Longa Permanência para Idosos , Deficiência Intelectual/reabilitação , Casas de Saúde , Idoso , Idoso de 80 Anos ou mais , Cuidadores , Família , Humanos , Pais , Relações Profissional-Família , Qualidade de Vida , Vitória
6.
Emerg Med J ; 26(10): 758-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19773513

RESUMO

The case history is presented of a normally fit and well 28-year-old woman with idiopathic right ventricular outflow tract ventricular tachycardia (RVOT VT). Presentation was with a broad complex tachycardia unresponsive to first-line anti-arrhythmic drugs and DC cardioversion (immediate recurrence) but highly sensitive to flecainide and eventually successfully treated with catheter ablation. Assessment and management of broad complex tachycardia is challenging but requires a structured approach to the underlying differential diagnosis. Ventricular tachycardia may occur in structurally normal hearts and not cause haemodynamic compromise despite persistence over 48 h, as in this case. The clinical history, ECG morphology and response to adenosine were all instrumental in making the diagnosis and hence tailoring appropriate anti-arrhythmic therapy when DC cardioversion failed.


Assuntos
Taquicardia Ventricular/diagnóstico , Adulto , Diagnóstico Diferencial , Eletrocardiografia , Feminino , Humanos , Taquicardia Ventricular/terapia
7.
J Intellect Disabil Res ; 52(Pt 5): 404-14, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18205755

RESUMO

BACKGROUND: Australia's national ageing policy recognises that people ageing with intellectual disability (ID) require particular attention, yet there is no policy framework concerning this population. This study describes the distribution and characteristics of people with ID in residential aged care in Victoria, provides insights into the pathways they take into aged care, and gives some indications of how facilities adapt to their needs. METHOD: A postal survey was sent to 826 residential aged care facilities in Victoria, seeking information from directors about their residents with ID. Facilities that responded were fairly representative of all facilities in Victoria. FINDINGS: Residents with ID were younger, had entered at an earlier age and remained longer than other residents. Their reported dependency profile was similar to the general aged care population, although the incidence of dementia was lower. Primary areas of concern identified by providers were: inability to fit into the resident community, lack of participation in activities and lack of meaningful relationships. CONCLUSION: This study provides a first glimpse into how older people with ID find their way into aged care and how others view their experiences once there. It suggests that further investigation is required into the accuracy of assessment undertaken prior to entry to more clearly understand whether residents with ID are inappropriately placed in residential aged as a result of a shortage of disability accommodation and inadequate resources to support aging in place for those in such accommodation.


Assuntos
Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Instituição de Longa Permanência para Idosos/estatística & dados numéricos , Deficiência Intelectual/reabilitação , Instituições Residenciais/estatística & dados numéricos , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/psicologia , Feminino , Pesquisas sobre Atenção à Saúde/estatística & dados numéricos , Humanos , Deficiência Intelectual/epidemiologia , Deficiência Intelectual/psicologia , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Índice de Gravidade de Doença , Vitória/epidemiologia
8.
Br J Anaesth ; 99(3): 384-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17611250

RESUMO

We present a case of fatal cardiac tamponade that occurred in association with a peripherally inserted central catheter (PICC) inserted from the right antecubital fossa. Migration of the catheter from the right atrium within 24 h of insertion lead to the administration of a potassium-enriched sodium chloride solution into the pericardial space with the development of ST-segment elevation and progression to pulseless electrical activity and, subsequently, ventricular fibrillation. Although signs of tamponade were seen on echocardiography, we propose that myocardial hyperkalaemia from the diffusion of potassium through the epicardium accounted for some of the clinical picture. PICC lines carry a greater risk of migration because of the tip movement associated with arm abduction and, therefore, care must be taken to ensure that the catheter tip is correctly positioned to reduce this risk. When such catheters are used for intra-operative central venous access, we believe chest radiography is mandatory before fluid administration through the catheter, but that this is unnecessary when the catheter is being used solely for central venous pressure monitoring. The use of softer catheters may reduce the risk of vessel perforation. Once tamponade is suspected, all drugs and infusions administered via the catheter should be reviewed, the catheter aspirated and echocardiography performed urgently. This may be facilitated by the greater availability of limited bedside echocardiography within critical care units and theatre complexes.


Assuntos
Tamponamento Cardíaco/etiologia , Cateterismo Venoso Central/efeitos adversos , Complicações Pós-Operatórias , Adulto , Cateterismo Venoso Central/instrumentação , Evolução Fatal , Feminino , Hidratação/efeitos adversos , Hidratação/métodos , Migração de Corpo Estranho/complicações , Humanos , Hiperpotassemia/etiologia
9.
Emerg Med J ; 23(12): 918-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17130598

RESUMO

Following the accession of Poland to the European Union in 2004, large numbers of Polish migrant workers have come to the UK. We describe how this migration has impacted on an emergency department in the West Midlands, and suggest advice that should be given to such visitors about how to use the NHS.


Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Mau Uso de Serviços de Saúde/estatística & dados numéricos , Migrantes/estatística & dados numéricos , Serviço Hospitalar de Emergência/tendências , Emigração e Imigração , Inglaterra , Etnicidade/estatística & dados numéricos , Pesquisa sobre Serviços de Saúde , Humanos , Polônia/etnologia
10.
BMJ ; 331(7513): 373-7, 2005 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-16096304

RESUMO

OBJECTIVE: To determine whether motivational interviewing--a behavioural therapy for addictions-provided at home by specially trained midwives helps pregnant smokers to quit. DESIGN: Randomised controlled non-blinded trial analysed by intention to treat. SETTING: Clinics attached to two maternity hospitals in Glasgow. PARTICIPANTS: 762/1684 pregnant women who were regular smokers at antenatal booking: 351 in intervention group and 411 in control group. INTERVENTIONS: All women received standard health promotion information. Women in the intervention group were offered motivational interviewing at home. All interviews were recorded. MAIN OUTCOME MEASURES: Self reported smoking cessation verified by plasma or salivary cotinine concentration. RESULTS: 17/351 (4.8%) women in the intervention group stopped smoking (according to self report and serum cotinine concentration < 13.7 ng/ml) compared with 19/411(4.6%) in the control group. Fifteen (4.2%) women in the intervention group cut down (self report and cotinine concentration less than half that at booking) compared with 26 (6.3%) in the control group. Fewer women in the intervention group reported smoking more (18 (5.1%) v 44 (10.7%); relative risk 0.48, 95% confidence interval 0.28 to 0.81). Birth weight did not differ significantly (mean 3078 g v 3048 g). CONCLUSION: Good quality motivational interviewing did not significantly increase smoking cessation among pregnant women.


Assuntos
Aconselhamento/métodos , Serviços de Assistência Domiciliar/organização & administração , Tocologia/métodos , Cuidado Pré-Natal/métodos , Abandono do Hábito de Fumar/métodos , Adulto , Cotinina/análise , Feminino , Humanos , Motivação , Cooperação do Paciente , Gravidez , Saliva/química , Fumar/psicologia , Abandono do Hábito de Fumar/psicologia , Prevenção do Hábito de Fumar , Resultado do Tratamento
11.
Methods Inf Med ; 43(4): 315-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15472740

RESUMO

OBJECTIVES: To design, implement in Java, and evaluate a method and means for the automated localization of artificial landmarks in optical images for tuned-aperture computed tomography (TACT) that allows the replacement of radiographic with optical landmarks. METHODS: Circular, colored, optical landmarks were designed to provide flexibility with regard to landmark constellation, imaging equipment, and lighting conditions. The landmark detection was based on Hough transforms (HT) for ellipses and lines. The HT for ellipses was extended to enable selective detection of bright ellipses on a dark background and vice versa, and the number of irrelevant votes in the accumulator arrays was reduced. An experiment was performed in vitro to test the automated landmark localization scheme, verify registration accuracy, and measure the required computation time. RESULTS: A visual evaluation of the tomographic slices that were produced using the new method revealed good registration accuracy. A comparison to tomographic slices similarly produced by means of conventional TACT showed identical results. The algorithm ran sufficiently fast on standard hardware to allow landmark localization in "real time" during successive image acquisition in clinical applications. CONCLUSIONS: The proposed method provides robust automated localization of landmarks in optical images. Using a hybrid imaging system, TACT can now be clinically applied without manual interaction of a human operator and without radiopaque landmarks, which might cover anatomic details of diagnostic interest.


Assuntos
Imageamento Tridimensional , Interpretação de Imagem Radiográfica Assistida por Computador/instrumentação , Radiografia Dentária Digital/instrumentação , Tomografia Computadorizada por Raios X/instrumentação , Algoritmos , Humanos , Aplicações da Informática Médica , Intensificação de Imagem Radiográfica , Processamento de Sinais Assistido por Computador
12.
Dentomaxillofac Radiol ; 31(5): 299-304, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12203128

RESUMO

OBJECTIVES: This study compared the accuracy of three radiographic imaging modalities for the detection of artificially induced radicular fractures on maxillary anterior teeth. METHODS: Fractures were induced in 28 of 54 maxillary incisors in 15 cadaver specimens using a distally directed force. Radiographs evaluated included conventional two-dimensional direct digital radiographs (DDI), unprocessed Tuned Aperture Computed Tomography (TACT-U) and iteratively restored TACT (TACT-IR). Eight observers recorded their findings using a five-point confidence-rating scale. Receiver Operating Characteristic (ROC) analyses were done, followed by ANOVA to test for significant effects of observers, imaging modality and fracture location. Post hoc tests were carried out in instances where ANOVA indicated significance. RESULTS: The areas under the ROC-curves (A(z)) were, respectively: DDI: 0.53; TACT-U: 0.83 and TACT-IR: 0.97. TACT-IR and TACT-U performed significantly better than DDI (P < 0.001) with TACT-IR providing a higher detection accuracy than TACT-U (P < 0.033). A difference in detection accuracy was also noted based on fracture location (P < 0.001). Tukey's post hoc analyses revealed that fractures extending beyond the middle third of the root were more accurately detected. Inter-observer agreement was 0.68, and intra-examiner agreement, 0.87 (kappa analysis). CONCLUSIONS: TACT performed significantly better than direct digital images in detecting trauma-induced radicular fractures in unrestored, maxillary anterior teeth.


Assuntos
Incisivo/lesões , Fraturas dos Dentes/diagnóstico por imagem , Raiz Dentária/lesões , Análise de Variância , Área Sob a Curva , Humanos , Maxila , Variações Dependentes do Observador , Curva ROC , Radiografia Dentária Digital , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos
13.
Dentomaxillofac Radiol ; 31(3): 187-92, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12058267

RESUMO

OBJECTIVE: To develop a three-dimensional (3D) model for quantitative analysis of image subtraction methods simulating clinical conditions and relevant to dental radiology. METHOD: A high-resolution volume representation of a formalin-preserved segment of a human maxilla was synthesized from a set of 51 digital radiographs equidistantly covering the entire sampling aperture by means of Tuned-Aperture Computed Tomography (TACT). Two-dimensional (2D) projection renderings of a 3D model were generated yielding arbitrary but well-known 2D projections with, and without, structured noise producing 'virtual radiographs'. RESULTS: Virtual radiographs were found to be similar to actual clinical images with respect to appearance, structure, and texture. Because the TACT reconstruction process allows all possible positions and orientations of source, specimen, and image plane to be simulated with negligible under sampling over a reasonable range of solid angles (sampling aperture), the resulting 3D model provided a rigorous method for establishing a truly objective gold standard (ground truth) for testing different registration techniques. CONCLUSIONS: TACT image registration can be assessed quantitatively by comparing actually observed vs theoretically professed parameters that presumably constrain the underlying projection geometries. Other attributes that vary from one method to the next, such as the use of nonlinear or region-specific techniques to facilitate registration, likewise, now can be rigorously measured by context-based methods such as quantitative determination of image similarity. Hence, a 3D model that renders idealized virtual radiographs from any desired projection geometry makes possible truly objective comparison of various digital subtraction techniques.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Radiografia Dentária Digital/métodos , Técnica de Subtração , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Artefatos , Simulação por Computador , Humanos , Maxila/diagnóstico por imagem , Processamento de Sinais Assistido por Computador , Interface Usuário-Computador
14.
Dentomaxillofac Radiol ; 31(4): 240-8, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12087441

RESUMO

OBJECTIVE: To design, fabricate, and perform preliminary in vitro testing of a portable, hand-held, three-dimensional (3D) dental X-ray system using options unique to Tuned-Aperture Computed Tomography (TACT). The design allows for task-specific positioning over an unlimited range of user-selected angles and incorporates an integrated laser guidance system to constrain the focal-object distance. METHODS: A prototype system was fabricated consisting of an extremely lightweight X-ray source cantilevered from an aluminum gunstock-type handle to which a transparent radiation scatter shield was attached. Aiming was facilitated by task-specific visual cues used in conjunction with a spherically shaped radiolucent alignment jig coupled to the tissues of interest. Proper range was assured by a laser-assisted guidance system. The image transducer was an extrinsically modified commercially available CMOS device. The irradiated patient was simulated by a DXTTR phantom. RESULTS: The prototype demonstrated automated display of radiographed intra-oral tissues in three dimensions from arbitrary projection geometries and simulated task-specific sequences. Uncontrolled movements between exposures produced no obvious degeneration of 3D image quality. The aiming system minimized technical errors from misangulation. All dental regions in the phantom were imaged without difficulty. Projected risk was observed to be within clinically acceptable limits. CONCLUSIONS: Task-specific 3D images can be generated from as few as three uncontrolled projections. Total exposures can be prorated to levels not greatly exceeding those required for conventional two-dimensional radiographs of comparable image quality. Predicted radiation risks lie well below existing guidelines for occupational exposure.


Assuntos
Equipamentos Odontológicos , Imageamento Tridimensional/instrumentação , Radiografia Dentária Digital/instrumentação , Tomografia Computadorizada por Raios X/instrumentação , Desenho de Equipamento , Humanos , Lasers , Imagens de Fantasmas , Doses de Radiação , Tecnologia Radiológica , Tomografia Computadorizada por Raios X/métodos
15.
Dentomaxillofac Radiol ; 31(4): 249-56, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12087442

RESUMO

OBJECTIVES: To implement, refine, and evaluate a generalized TACT reconstruction method that corrects for misregistration caused by uncontrolled variations in projective magnification, alleviates normalization artifacts at borders of backprojections, and exploits all available source information to minimize losses produced from projective truncations in three dimensions. METHODS: A new Java-based software application was designed and tested in vitro using clinically representive data derived from four titanium dental implants in a cadaver jaw segment. These implants were irradiated by an intra-oral X-ray machine from various angles and distances using a solid-state sensor producing 48 radiographs. Six radiopaque markers were attached to the segment facilitating inference of associated projection geometries from analyses of the distributions of their respective shadows as seen by the sensor. Three-dimensional (3D) images were produced using the new algorithm, and the results were compared with those obtained from existing code. RESULTS: Slices processed using the new program were corrected for magnification errors. The resulting 3D displays showed significantly reduced tomosynthetic blur relative to uncorrected counterparts. The new reconstructions also minimized known border artifacts and made use of all available information. These images demonstrated apparent details otherwise hidden or lost when comparably processed using the control algorithm. CONCLUSIONS: The new software reduces both misregistration and scaling artifacts in tomosynthetically reconstructed slices. Hence, these modifications are expected to increase diagnostic accuracy and facilitate the appropriate application of TACT to an enlarged set of diagnostic tasks as compared with earlier implementations of the method.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional/métodos , Radiografia Dentária Digital/métodos , Tomografia Computadorizada por Raios X/métodos , Artefatos , Humanos , Mandíbula/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador , Ampliação Radiográfica , Software , Tecnologia Radiológica
16.
Dentomaxillofac Radiol ; 30(6): 319-24, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11641730

RESUMO

OBJECTIVES: To compare the diagnostic efficacy of tuned aperture computed tomography (TACT) with the application of the 'buccal object rule' (BOR) in the localization of simulated periodontal defects. METHODS: Thirty interproximal sites were selected in fifteen cadaver segments of maxillae and mandible. Artificial periodontal defects were created using round burs and 40% formic acid in the buccal, lingual or mid-buccolingual areas. Eight basis projections were obtained and TACT slices were reconstructed for each region of interest. Two of the basis images were used in application of BOR for localization of the defect. Eight observers scored the location of defects using TACT slices and the paired radiographs separately. Data were analysed using the kappa statistic and ANOVA. RESULTS: A mean weighted kappa of 0.14 for localization was obtained with both BOR and TACT. Using ANOVA, there was no significant difference between modality and observer. There was however, a significant difference (P=0.019) between different defect sizes. Both modalities performed better with larger defect sizes. TACT performed slightly better than BOR when the smaller lesions were included; however, with larger lesions, this trend was reversed. CONCLUSIONS: The results confirm the relationship between correlation distance (the resultant slice width) and object size in the application of TACT for localization. BOR remains a simple yet effective tool for localization. The clinical significance is not clear considering the low kappa scores obtained with both the modalities.


Assuntos
Perda do Osso Alveolar/diagnóstico por imagem , Radiografia Dentária Digital/métodos , Algoritmos , Análise de Variância , Humanos , Variações Dependentes do Observador , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos
17.
J Dent Res ; 80(7): 1621-4, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11597021

RESUMO

Quantification of osseous healing is a challenging task, requiring expensive advanced imaging modalities. To improve diagnostic osseous imaging, we undertook this prospective study to explore the potential of Tuned Aperture Computed Tomography. Eighty defects in 20 rabbit mandibles, randomly carrying an osteoblast suspension or a polymer matrix or a combination thereof or no treatment, were imaged at 3, 6, 9, and 12 weeks post-surgery. TACT slices, iteratively restored TACT, and conventional digital radiographs were evaluated. Mean-gray-value distribution within regions of interest was correlated with histomorphometric data. Lesions treated with osteoblast/polymer-matrix delivery systems demonstrated the highest mean gray-value, while the diagnostic efficacy of TACT-IR was significantly better than that of other imaging modalities (p < 0.001). Thus, TACT is an accurate imaging modality for non-destructive quantification of osseous dynamics.


Assuntos
Osteogênese , Tomografia Computadorizada por Raios X/métodos , Cicatrização , Análise de Variância , Animais , Materiais Biocompatíveis , Imageamento Tridimensional , Ácido Láctico , Mandíbula/cirurgia , Osteoblastos/fisiologia , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros , Estudos Prospectivos , Coelhos , Distribuição Aleatória , Estatísticas não Paramétricas
18.
Bioorg Med Chem Lett ; 11(19): 2651-3, 2001 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-11551770

RESUMO

The potency and selectivity of a series of 5-hetero-2-iminohexahydroazepines were examined as inhibitors of the three human NOS isoforms. The effect of ring substitution of the 5-carbon for a heteroatom is presented. Potencies (IC(50)'s) for these inhibitors are in the low micromolar range for hi-NOS with some examples exhibiting a 500x selectivity versus hec-NOS.


Assuntos
Azepinas/farmacologia , Inibidores Enzimáticos/farmacologia , Isoenzimas/antagonistas & inibidores , Óxido Nítrico Sintase/antagonistas & inibidores , Azepinas/síntese química , Azepinas/química , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Concentração Inibidora 50 , Óxido Nítrico Sintase Tipo II , Relação Estrutura-Atividade
19.
Bone ; 29(2): 180-4, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11502481

RESUMO

Fractal analysis was used to quantify changes in trabecular bone induced through the use of a rat tail-suspension model to simulate microgravity-induced osteopenia. Fractal dimensions were estimated from digitized radiographs obtained from tail-suspended and ambulatory rats. Fifty 4-month-old male Sprague-Dawley rats were divided into groups of 24 ambulatory (control) and 26 suspended (test) animals. Rats of both groups were killed after periods of 1, 4, and 8 weeks. Femurs and tibiae were removed and radiographed with standard intraoral films and digitized using a flatbed scanner. Square regions of interest were cropped at proximal, middle, and distal areas of each bone. Fractal dimensions were estimated from slopes of regression lines fitted to circularly averaged plots of log power vs. log spatial frequency. The results showed that the computed fractal dimensions were significantly greater for images of trabecular bones from tail-suspended groups than for ambulatory groups (p < 0.01) at 1 week. Periods between 1 and 4 weeks likewise yielded significantly different estimates (p < 0.05), consistent with an increase in bone loss. In the tibiae, the proximal regions of the suspended group produced significantly greater fractal dimensions than other regions (p < 0.05), which suggests they were more susceptible to unloading. The data are consistent with other studies demonstrating osteopenia in microgravity environments and the regional response to skeletal unloading. Thus, fractal analysis could be a useful technique to evaluate the structural changes of bone.


Assuntos
Osso e Ossos/fisiologia , Fractais , Ausência de Peso , Animais , Osso e Ossos/diagnóstico por imagem , Radiografia , Ratos , Ratos Sprague-Dawley
20.
Eur Radiol ; 11(8): 1510-5, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11519567

RESUMO

The aim of this study was to evaluate osseous healing in mandibular defects using fractal analyses on conventional radiographs and tuned aperture computed tomography (TACT; OrthoTACT, Instrumentarium Imaging, Helsinki, Finland) images. Eighty test sites on the inferior margins of rabbit mandibles were subject to lesion induction and treated with one of the following: no treatment (controls); osteoblasts only; polymer matrix only; or osteoblast-polymer matrix (OPM) combination. Images were acquired using conventional radiography and TACT, including unprocessed TACT (TACT-U) and iteratively restored TACT (TACT-IR). Healing was followed up over time and images acquired at 3, 6, 9, and 12 weeks post-surgery. Fractal dimension (FD) was computed within regions of interest in the defects using the TACT workbench. Results were analyzed for effects produced by imaging modality, treatment modality, time after surgery and lesion location. Histomorphometric data were available to assess ground truth. Significant differences (p < 0.0001) were noted based on imaging modality with TACT-IR recording the highest mean fractal dimension (MFD), followed by TACT-U and conventional images, in that order. Sites treated with OPM recorded the highest MFDs among all treatment modalities (p < 0.0001). The highest MFD based on time was recorded at 3 weeks and differed significantly with 12 weeks (p < 0.035). Correlation of FD with results of histomorphometric data was high (r = 0.79; p < 0.001). The FD computed on TACT-IR showed the highest correlation with histomorphometric data, thus establishing the fact TACT is a more efficient and accurate imaging modality for quantification of osseous changes within healing bony defects.


Assuntos
Osso e Ossos/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Tomografia Computadorizada por Raios X/métodos , Cicatrização , Animais , Osso e Ossos/patologia , Osso e Ossos/fisiologia , Células Cultivadas , Fractais , Mandíbula/diagnóstico por imagem , Mandíbula/patologia , Mandíbula/fisiologia , Osteoblastos , Polímeros/administração & dosagem , Coelhos , Engenharia Tecidual
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