RESUMEN
Pupillometry has been widely employed in the evaluation of a large number of pathological conditions, including intracranial pathology. The recent introduction of a portable, user-friendly, infrared pupillometer (ForSite, NeurOptics Inc., Irvine, CA) has enabled the accurate and reproducible measurement of several pupillary parameters, such as maximum and minimum apertures, constriction and dilation velocities, and latency period. It should be noted that various clinical conditions, especially neurological and ocular diseases, as well as numerous medications, may interfere with the measurements. Furthermore, a number of physiological parameters, such as the intensity of retinal illumination, the level of patient's alertness, the intensity of ambient light, as well as the time of day that the examination is performed may alter the obtained values. The potential implications of pupillometry in the clinical assessment of neurosurgical patients, including its complex relationship to intracranial pressure changes, mandate the undertaking of prospective clinical studies validating the clinical significance of this noninvasive, diagnostic modality.
Asunto(s)
Anisocoria/diagnóstico , Lesiones Encefálicas/cirugía , Rayos Infrarrojos , Hipertensión Intracraneal/cirugía , Procedimientos Neuroquirúrgicos/métodos , Lesiones Encefálicas/complicaciones , Diagnóstico Diferencial , Humanos , Hipertensión Intracraneal/etiologíaRESUMEN
OBJECT: The authors describe the prospective use of a new hand-held point-and-shoot pupillometer (NeurOptics) to assess pupil function quantitatively. METHODS: Repetitive measurements were made in 90 pediatric participants ranging in age from 1 to 18 years, providing a total of 100 measurements under ambient light conditions. The participants consisted of 45 patients without known intracranial or ophthalmological pathological conditions as well as 45 volunteers in the outpatient setting. Quantitative pupil measurements were reliably replicated in the study participants. The mean resting pupil aperture was 4.11 mm and the minimal diameter after stimulation was 2.65 mm, resulting in a 36% change in pupil size. The mean constriction velocity was 2.34 mm/second, with a mean dilation velocity of 2.2 mm/second. CONCLUSION: Pupil symmetry was impressive in the entire cohort.
Asunto(s)
Técnicas de Diagnóstico Oftalmológico , Pupila/fisiología , Adolescente , Niño , Preescolar , Técnicas de Diagnóstico Oftalmológico/instrumentación , Técnicas de Diagnóstico Oftalmológico/normas , Diseño de Equipo , Humanos , Lactante , Recién Nacido , Estudios Prospectivos , Tiempo de Reacción , Valores de ReferenciaRESUMEN
This report reviews three categories of precursor cells present within adults. The first category of precursor cell, the epiblast-like stem cell, has the potential of forming cells from all three embryonic germ layer lineages, e.g., ectoderm, mesoderm, and endoderm. The second category of precursor cell, the germ layer lineage stem cell, consists of three separate cells. Each of the three cells is committed to form cells limited to a specific embryonic germ layer lineage. Thus the second category consists of germ layer lineage ectodermal stem cells, germ layer lineage mesodermal stem cells, and germ layer lineage endodermal stem cells. The third category of precursor cells, progenitor cells, contains a multitude of cells. These cells are committed to form specific cell and tissue types and are the immediate precursors to the differentiated cells and tissues of the adult. The three categories of precursor cells can be readily isolated from adult tissues. They can be distinguished from each other based on their size, growth in cell culture, expressed genes, cell surface markers, and potential for differentiation. This report also discusses new findings. These findings include the karyotypic analysis of germ layer lineage stem cells; the appearance of dopaminergic neurons after implantation of naive adult pluripotent stem cells into a 6-hydroxydopamine-lesioned Parkinson's model; and the use of adult stem cells as transport mechanisms for exogenous genetic material. We conclude by discussing the potential roles of adult-derived precursor cells as building blocks for tissue repair and as delivery vehicles for molecular medicine.
Asunto(s)
Trasplante de Células Madre , Células Madre/citología , Células Madre/fisiología , Heridas y Lesiones/terapia , Adulto , Humanos , Cariotipificación , Mesodermo/citología , Mesodermo/fisiologíaRESUMEN
STUDY DESIGN: Retrospective analysis of the fusion rate of a group of 38 patients having undergone anterior screw fixation for type II and "shallow" type III odontoid fractures. OBJECTIVE.: To determine primarily the long-term fusion rate after anterior screw fixation and to study the clinical characteristics of patients that have a statistically significant or nonsignificant influence on successful outcome. SUMMARY OF BACKGROUND DATA: Long-term outcome of anterior screw fixation for odontoid fractures has been evaluated in very few studies. This information should be critical for further establishing this technique as a major therapeutic strategy for these cases. METHODS: Thirty-eight patients, 25 males and 13 females (with mean age 48.4 +/- 0.4 years), with type II and rostral type III odontoid fractures, underwent anterior cannulated screw fixation during a 62-month period. Radiologic examination of the cervical spine with plain radiographs was performed at 6 weeks, and 2, 6, 12, and 24 months, while computerized tomography of the upper cervical spine (C1-C3) was obtained at 6 months after surgery. Follow-up was available for 31 patients, and the follow-up time ranged from 39 to 87 months (mean 58.4). RESULTS: Radiographic evaluation of the follow-up group showed satisfactory bony fusion and no evidence of abnormal movement at the fracture site in 27 (87.1%) patients. Pseudarthrosis developed in 4 (12.9%) patients; however, 3 (9.6%) of them without instability and 1 (3.2%) with instability. One (3.2%) patient had an instrumentation failure without instability. CONCLUSIONS: In our series, anterior odontoid screw fixation comprised a safe therapeutic modality with high stability and low mechanical failure rates during short-term and long-term follow-up.
Asunto(s)
Tornillos Óseos , Fijación Interna de Fracturas/instrumentación , Apófisis Odontoides/lesiones , Apófisis Odontoides/cirugía , Fracturas de la Columna Vertebral/cirugía , Fusión Vertebral/instrumentación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Fijación Interna de Fracturas/métodos , Humanos , Masculino , Persona de Mediana Edad , Apófisis Odontoides/diagnóstico por imagen , Estudios Retrospectivos , Fracturas de la Columna Vertebral/clasificación , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fusión Vertebral/métodos , Tomografía Computarizada por Rayos XRESUMEN
The authors offer a brief overview of early theories and treatments of sciatica. Tracing medical traditions through early Greek, Roman, and Eastern epochs, the authors demonstrate the slow sequential steps that were required to delineate this disease as a uniquely human affliction.