RESUMEN
AIM: The purpose of our study was to correctly fuse MRI and SPECT ¹¹¹In WBC and 99m Tc HDP images using companion CT images. The fused images could be used to assess proper surgical approach in treatment of the diabetic foot. METHODS: Nine patients who had dual energy ¹¹¹In WBC/ 99m Tc HDP SPECT/CT and MRI studies within a week were investigated in an ongoing project. A GE Infinia SPECT/CT camera and Siemens MAGNETOM 1.5T MR system were used in this study. First, the MRI and corresponding CT images were coregistrated using a transformation based on normalized mutual information. The transformation was saved and used for MRI and ¹¹¹In WBC/ 99m Tc HDP SPECT fusion. A Jaszczak phantom study was also performed in order to estimate accuracy of MRI/ SPECT fusion. RESULTS: The Jaszczak phantom study with 3.7 MBq ¹¹¹In hot sphere showed that MRI/SPECT alignment using the approach described above produced registration with 0.7 ± 0.4 mm accuracy in all three dimensions (3D). The nine clinical cases were visually evaluated and showed 1-2 mm 3D fusion accuracy. MRI provides almost perfect anatomy of soft tissue and bony structures but it may exaggerate the extent of infection. ¹¹¹In WBC/99m Tc HDP SPECT imaging is more accurate for infection detection but lacks anatomical reference. Combination of these images proved an essential adjunct to diagnosis. A clinical utility of the approach is illustrated in two clinical examples. CONCLUSION: The CT in dual energy ¹¹¹In WBC/99m Tc HDP SPECT/CT studies can be used to accurately fuse and compare ¹¹¹In WBC/99m Tc HDP SPECT and MRI images of the diabetic foot. This can significantly help in conservative treatment planning and limb salvage procedures in treatment of diabetic foot infections.
Asunto(s)
Pie Diabético/diagnóstico , Leucocitos/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Medronato de Tecnecio Tc 99m/análogos & derivados , Tomografía Computarizada de Emisión de Fotón Único/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Femenino , Humanos , Radioisótopos de Indio , Masculino , Persona de Mediana Edad , Imagen Multimodal/métodos , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
We reviewed, retrospectively, 13 patients who had undergone open anterograde autologous bone grafting of the talus for symptomatic osteochondral defects of the dome of the talus. The mean age of the seven men and six women was 38.4 years. The defects included the full thickness of articular cartilage, extended through the subchondral plate and were associated with subchondral cysts. Six patients (46%) were clinical failures requiring further surgery. Of the remaining seven, functional outcome results were obtained at a mean of 51.9 months after surgery. The mean outcome scores for the Musculoskeletal Outcomes Data Evaluation and Management System foot and ankle questionnaire and the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale were 87.0 and 84.3, respectively. There was an overall 46.2% patient satisfaction rate. We believe that the technique of autologous bone grafting presented should be used with extreme caution, when considered as the primary treatment for the adult patient with a symptomatic advanced osteochondral defect of the talus.
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Quistes Óseos/cirugía , Trasplante Óseo/métodos , Astrágalo/cirugía , Adulto , Traumatismos del Tobillo/complicaciones , Quistes Óseos/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Astrágalo/diagnóstico por imagen , Astrágalo/lesiones , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
We reviewed retrospectively 11 patients who had been treated surgically by open autologous osteochondral grafting for symptomatic chondral or osteochondral defects of the dome of the talus between 1996 and 1999. The mean ages of the eight men and three women were 34.2 and 25.9 years, respectively, with a mean time to follow-up of 24 months. The results of functional outcome were prospectively obtained using the MODEMS AAOS foot and ankle follow-up questionnaire, the AOFAS ankle-hindfoot scale and the Hannover scores for the ankle. The grafts were harvested from the ipsilateral knee. Good to excellent results were obtained for the ankle without adverse effects on the knee. We believe that autologous osteochondral grafting should be considered for the patient with a symptomatic osteochondral defect of the talus.
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Articulación del Tobillo/cirugía , Trasplante Óseo , Cartílago/trasplante , Osteocondritis Disecante/cirugía , Osteonecrosis/cirugía , Astrágalo , Adolescente , Adulto , Articulación del Tobillo/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Trasplante Autólogo , Resultado del TratamientoRESUMEN
Over just the past few years, tremendous progress has been made in unraveling the molecular basis of the circadian clock in mammals. This success has been primarily due to an approach whereby mutations are induced randomly in the germ line and the offspring of the mutagenized animals are tested for abnormal circadian phenotype. Circadian clock genes have been discovered this way in both fruit flies and mice and it is now clear that most, if not all clock genes show homology between flies and mammals, including humans. This 'forward genetics' approach is a powerful tool for uncovering genes which underline complex behaviors and brain disorders. Even when a complex neural function involves many, many genes, mutating just one of these genes can have pronounced effects on the expressed behavior and can lead to the discovery of other genes, and their protein products, that interact directly or indirectly with the mutated gene.
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Encefalopatías/genética , Ritmo Circadiano/genética , Genética Conductual/métodos , Transactivadores/fisiología , Animales , Proteínas CLOCK , Técnicas Genéticas/tendencias , Humanos , Transactivadores/genéticaRESUMEN
Calorie restriction and other situations of reduced glucose availability in rodents alter the entraining effects of light on the circadian pacemaker located in the suprachiasmatic nuclei. Siberian and Syrian hamsters are photoperiodic species that are sexually active when exposed to long summer-like photoperiods, while both species show opposite changes in body mass when transferred from long to short or short to long days. Because metabolic cues may fine tune the photoperiodic responses via the suprachiasmatic nuclei, we tested whether timed calorie restriction can alter the photic synchronization of the light-entrainable pacemaker in these two hamster species exposed to long photoperiods. Siberian and Syrian hamsters were exposed to 16 h:8 h light:dark cycles and received daily hypocaloric (75% of daily food intake) or normocaloric diet (100% of daily food intake) 4 h after light onset. Four weeks later, hamsters were transferred to constant darkness and fed ad libitum. The onset of the nocturnal pattern of locomotor activity was phase advanced by 1.5 h in calorie-restricted Siberian hamsters, but not in Syrian hamsters. The lack of phase change in calorie-restricted Syrian hamsters was also observed in individuals exposed to 14 h:10 h dim light:dark cycles and fed with lower hypocaloric food (i.e. 60% of daily food intake) 2 h after light onset. Moreover, in hamsters housed in constant darkness and fed ad lib., light-induced phase shifts of the locomotor activity in Siberian hamsters, but not in Syrian hamsters were significantly reduced when glucose utilization was blocked by pretreatment with 500 mg/kg i.p. 2-deoxy-D-glucose. Taken together, these results show that the photic synchronization of the light-entrainable pacemaker can be modulated by metabolic cues in Siberian hamsters, but not in Syrian hamsters maintained on long days.
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Ritmo Circadiano/fisiología , Mesocricetus/fisiología , Actividad Motora , Phodopus/fisiología , Fotoperiodo , Animales , Relojes Biológicos , Cricetinae , Oscuridad , Ingestión de Energía , Privación de Alimentos/fisiología , Luz , Masculino , Especificidad de la Especie , Núcleo Supraquiasmático/fisiologíaRESUMEN
In recent years, there has been extraordinary progress in elucidating the molecular components of the mammalian circadian clock system. The discovery of circadian clock genes in lower organisms (such as fruit flies and fungi), which show many similarities with clock genes in mammals, together with advances in mouse molecular genetics have led to major new discoveries on the molecular and genetic basis of mammalian circadian rhythms. This article reviews both of these lines of research from an historical perspective and discusses how these lines have merged to provide unique insights into the molecular mechanisms of circadian function. The review also speculates on how the discovery of circadian clock genes may lead directly or indirectly to the discovery of mammalian sleep genes. The determination of the molecular mechanisms via which circadian clock genes (and their protein products) regulate the timing and the need for sleep, and the identification of new genes involved in sleep regulation, may produce new information on the genetic and molecular control of sleep which could ultimately lead to the development of new treatments for sleep disorders.
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Ritmo Circadiano/genética , Sueño/genética , Animales , Proteínas CLOCK , Drosophila/genética , Drosophila/fisiología , Mamíferos , Ratones , Neurospora/genética , Neurospora/fisiología , Transactivadores/genéticaRESUMEN
Shift work is associated with increased cardiovascular morbidity and mortality. Whereas it has been suggested that continuous shifting of the circadian clock/sleep-wake cycle may have negative effects on health, there is very little experimental evidence to support such a hypothesis. Cardiomyopathic Syrian hamsters were either maintained on a fixed light-dark (LD) cycle (n = 31) or were subjected to a 12-h phase shift in the LD cycle on a weekly basis (n = 32). The duration of the life span was recorded for each animal. Chronic reversal of the external LD cycle at weekly intervals resulted in a significant decrease in the survival time in cardiomyopathic hamsters with the median life span being reduced by 11%. Disrupting normal circadian rhythmicity in an animal susceptible to early mortality due to cardiac disease results in a further decrease in longevity. The deleterious effects of the chronic phase shifts in the LD cycle in cardiomyopathic hamsters may be related to reports of increased cardiovascular morbidity and mortality in humans engaged in shift work.
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Cardiomiopatías/fisiopatología , Ritmo Circadiano/fisiología , Animales , Cardiomiopatías/patología , Cricetinae , Insuficiencia Cardíaca/patología , Longevidad/fisiología , Masculino , Mesocricetus , Actividad Motora/fisiología , Valores de Referencia , Análisis de Supervivencia , Factores de TiempoRESUMEN
The most commonly measured mouse behavior in fear conditioning tests is freezing. A technical limitation, particularly for genetic studies, is the method of direct observation used for quantifying this response, with the potential for bias or inconsistencies. We report the use of a computerized method based on latency between photobeam interruption measures as a reliable scoring criterion in mice. The different computer measures obtained during contextual fear conditioning tests showed high correlations with hand-scored freezing; r values ranged from 0.87 to 0.94. Previously reported strain differences between C57BL/6J and DBA/2J in context-dependent fear conditioning were also detected by the computer-based system. In addition, the use of computer-scored freezing of 199 (BALB/cJ x C57BL/6J)F2 mice enabled us to detect a suggestive gender-dependent chromosomal locus for contextual fear conditioning on distal chromosome 8 by QTL analysis. Automation of freeze scoring would significantly increase efficiency and reliability of this learning and memory test.