RESUMEN
BACKGROUND: The 12-gene Oncotype DX Colon Recurrence Score® result quantifies the recurrence risk in stage II/III colon cancer (CC). This real-world study investigated stage II CC patients whose treatment decisions incorporated the Recurrence Score® (RS) result. MATERIALS AND METHODS: This retrospective analysis of a prospectively designed cohort included all stage II, mismatch repair-proficient CC patients who underwent 12-gene testing through Clalit between January 2011 and December 2016 and had available data with a minimum 3-year follow-up. RESULTS: The analysis included 938 patients {median age 68 [interquartile range (IQR) 60-76] years; 96% T3 tumors}. The median RS was 26 (IQR 19-33) and the three RS categories (0-29, 30-40, 41-100) included 65%, 24%, and 11% of patients, respectively. Chemotherapy (CT) use differed significantly between the three RS categories (14%, 36%, and 60%, respectively; P < 0.001). The CT and observation-only groups were imbalanced with worse clinicopathologic characteristics in the former. Among observation-only patients, Kaplan-Meier (KM) estimates for recurrence-free interval (RFI) and CC-specific survival (CCSS) differed significantly between the three RS categories (P < 0.001). Clinical outcomes by treatment (CT versus observation) within each RS category revealed no differences in RFI and CCSS in the RS 0-29 and 30-40 categories. In contrast, in the RS 41-100 category, the difference in RFI trended toward significance (P = 0.066), and for CCSS, a statistically significant difference was observed, with better outcomes among CT-treated patients (P = 0.035). CONCLUSIONS: RS results are prognostic in stage II CC. Among RS 41-100 patients, outcomes were better in CT-treated versus observation-only patients despite worse clinicopathologic characteristics, suggesting that CT confers clinical benefit in high-risk patients.
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Edad de Inicio , Neoplasias Colorrectales , Predisposición Genética a la Enfermedad , Humanos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/epidemiología , Sitios Genéticos , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Estudio de Asociación del Genoma CompletoRESUMEN
There has been no major change of practice in gastrointestinal oncology at the European Society for Medical Oncology (ESMO) symposium 2021, but confirmation that immunotherapy in combination with chemotherapy has become standard of care in several indications. The European Organisation for Research and Treatment of Cancer (EORTC) Gastrointestinal Track Cancer Group has selected important phase II and III trials presented during the symposium across all gastrointestinal cancers as well as early reports on new drugs or new combinations that may change practice in the future.
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Neoplasias Gastrointestinales , Oncología Médica , Neoplasias Gastrointestinales/tratamiento farmacológico , Humanos , InmunoterapiaRESUMEN
BACKGROUND: Recent epidemiological studies indicate the rate of gastrointestinal (GI) malignancies among younger patients is increasing, mainly due to colorectal cancer. There is a paucity of data regarding the magnitude of treatment-related symptoms, psychosocial issues and potential unmet needs in this population. We aimed to characterize the needs of this population to evaluate whether unmet needs could be targeted by potential intervention. METHODS: Female and male patients diagnosed with cancer of the gastrointestinal tract <40y retrospectively completed a questionnaire to evaluate symptoms, daily function and unmet needs at pre-treatment, during and post-treatment. Comparisons were made by gender, disease stage and treatment modality. Multiple linear regression models evaluated effects of demographics, symptoms and needs on multiple domains of health-related-quality-of-life (using Short-Form Health Survey-12 and CARES). RESULTS: Fifty patients were enrolled (52 % female) to a pilot study. Median age at diagnosis was 35.5y (range, 21-40y). The symptoms that significantly increased from baseline to during and post-treatment were: diarrhea (37 %), sleeping disorder (32 %) and sexual dysfunction (40 %). Patients also reported significant deterioration in occupational activities and coping with children compared with baseline. Female patients reported significant unmet need for nutritional counseling and psychosocial support compared to male patients (p < 0.05). Patients treated with multimodality-treatment presented higher rates of unmet needs (p = 0.03). CONCLUSIONS: Young patients with GI cancers represent a group with unique characteristics and needs compared with published evidence on other young-onset malignancies. The distinctive symptoms and areas of treatment-related functional impairments indicate there are unmet needs, especially in the area of psychosocial support and nutritional counseling.
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Neoplasias Gastrointestinales/psicología , Calidad de Vida/psicología , Sobrevivientes/psicología , Adulto , Consejo , Estudios Transversales , Femenino , Humanos , Masculino , Evaluación de Necesidades , Proyectos Piloto , Estudios Retrospectivos , Apoyo Social , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Oncotype-DX assay has never been validated for BRCA mutation carriers. This study compares the recurrence score (RS) distribution in BRCA-positive breast cancer patients with that of a general population (GP) of patients and reports their outcomes. Eligible patients were BRCA carriers who performed the Oncotype-DX assay. Two sets of databases were cross-linked: BRCA carriers at Rabin Medical Center and Sheba Medical Center with Oncotype-DX tests performed through Clalit Health Services HMO, from 2003 to 2015. Fifty-eight BRCA patients were included (20 BRCA1, 38 BRCA2). The GP included 1020 patients. Compared to the GP, BRCA1 patients were younger, had higher rate of grade three tumors, and higher Ki67. BRCA2 patients had lower PR index, higher rate of grade three tumors, and higher Ki67. Among the GP, 52.9, 37.9, and 9.1 % had low, intermediate, and high risk RS, respectively. Corresponding rates were 15, 35, and 50 % in BRCA1 patients, and 18.4, 52.6, and 29 % in BRCA2 patients. Subgroup analysis revealed a similar RS distribution pattern regardless of the nodal status. Median follow-up was 45 months. Four BRCA patients (7 %) developed disease recurrence. RS of these patients were in the intermediate and low range. All recurrences occurred in chemo-naïve patients who had not undergone bilateral oophorectomy. This study revealed significantly different RS distributions between BRCA patients and the GP. RS values shifted toward high and intermediate risk categories. This pattern held regardless of the nodal status and was more pronounced in the BRCA1 group.
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Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias de la Mama/genética , Mutación , Recurrencia Local de Neoplasia/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Bases de Datos Genéticas , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Clasificación del Tumor , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/metabolismo , Pronóstico , Receptores de Estrógenos/metabolismo , Medición de RiesgoRESUMEN
STUDY QUESTION: Is a protocol that combines in vitro maturation of germinal vesicle-stage oocytes and their vitrification with freezing of cortical ovarian tissue feasible for use in fertility preservation for both chemotherapy-naive paediatric patients as well as patients after initiation of cancer therapy? SUMMARY ANSWER: Follicle-containing ovarian tissue as well as oocytes that can undergo maturation in vitro can be obtained from paediatric patients (including prepubertal girls) both before and after cancer therapy. WHAT IS KNOWN ALREADY: Anticancer therapy reduces the number of follicles/oocytes but this effect is less severe in young patients, particularly the paediatric age group. Autotransplantation of ovarian tissue has yielded to date 60 live births, including one from tissue that was cryostored in adolescence. However, it is assumed that autografting cryopreserved-thawed ovarian cortical tissue poses a risk of reseeding the malignancy. Immature oocytes can be collected from very young girls without hormonal stimulation and then matured in vitro and vitrified. We have previously shown that there is no difference in the number of ovarian cortical follicles between paediatric patients before and after chemotherapy. STUDY DESIGN, SIZE, DURATION: A prospective study was conducted in a cohort of 42 paediatric females with cancer (before and after therapy initiation) who underwent fertility preservation procedures in 2007-2014 at a single tertiary medical centre. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study group included girls and adolescent females with cancer: 22 before and 20 after chemotherapy. Following partial or complete oophorectomy, immature oocytes were either aspirated manually ex vivo from visible small antral follicles or filtered from spent media. Oocytes were incubated in oocyte maturation medium, and those that matured at 24 or 48 h were vitrified. Ovarian cortical tissue was cut and prepared for slow-gradual cryopreservation. Anti-Mullerian hormone (AMH) levels were measured in serum before and after oophorectomy. MAIN RESULTS AND ROLE OF CHANCE: Ovarian tissue was successfully collected from 78.7% of the 42 patients. Oocytes were obtained from 20 patients before chemotherapy and 13 after chemotherapy. The youngest patients from whom oocytes were retrieved were aged 2 years (two atretic follicles) and 3 years. Of the 395 oocytes collected, â¼30% were atretic (29.6% in the pre-chemotherapy group, 37% in the post-chemotherapy group). One hundred twenty-one oocytes (31%) were matured in vitro and vitrified: 67.8% from patients before chemotherapy, the rest after chemotherapy. Mature oocytes suitable for vitrification were obtained from 16/20 patients before chemotherapy and from 12/13 patients after chemotherapy (maturation rate, 32 and 26.4%, respectively). There were significant correlations of the number of vitrified oocytes with patient age (more matured oocytes with older age) (P = 0.001) and with pre-oophorectomy AMH levels (P = 0.038 pre-chemotherapy group, P = 0.029 post-chemotherapy group). Oocytes suitable for vitrification were obtained both by manual aspiration of antral follicles (45%) and from rinse solutions after dissection. There were significantly more matured oocytes in the pre-chemotherapy group from aspiration than in the post-chemotherapy group after both aspiration (P < 0.033) and retrieval from rinsing fluids (P < 0.044). The number of pre-antral follicles per histological section did not differ in the pre- versus post-chemotherapy. AMH levels dropped by approximately 50% after ovarian removal in both groups, with a significant correlation between pre- and post-oophorectomy levels (P = 0.002 pre-chemotherapy group, P = 0.001 post-chemotherapy group). LIMITATIONS, REASONS FOR CAUTION: There were no patients between 5 years and 10 years old in the post-chemotherapy group, which might have affected some results and correlations. Oocytes from patients soon after chemotherapy might be damaged, and caution is advised when using them for fertility-restoration purposes. The viability, development capability and fertilization potential of oocytes from paediatric patients, especially prepubertal and after chemotherapy, are unknown, in particular oocytes recovered from the media after the tissue dissection step. WIDER IMPLICATIONS OF THE FINDINGS: Although more oocytes were collected and matured from chemotherapy-naïve paediatric patients, ovarian tissue and immature oocytes were also retrieved from young girls in whom cancer therapy has already been initiated. Our centre has established a protocol for potential maximal fertility preservation in paediatric female patients with cancer. Vitrified-in vitro-matured oocytes may serve as an important gamete source in paediatric female patients with cancer because the risk of reseeding the disease is avoided. Further studies are needed on the fertility-restoring potential of oocytes from paediatric and prepubertal patients, especially after exposure to chemotherapy. STUDY FUNDING/COMPETING INTERESTS: The study was conducted as part of the routine procedures for fertility preservation at our IVF unit. No funding outside of the IVF laboratory was received. Funding for the AMH measurements was obtained by a research grant from the Israel Science Foundation (to B.-A.I., ISF 13-1873). None of the authors have competing interests. TRIAL REGISTRATION NUMBER: N/A.
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Criopreservación , Preservación de la Fertilidad/efectos adversos , Técnicas de Maduración In Vitro de los Oocitos , Neoplasias/patología , Oocitos/patología , Ovario/patología , Adolescente , Factores de Edad , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Niño , Preescolar , Estudios de Cohortes , Estudios de Factibilidad , Femenino , Humanos , Israel , Neoplasias/tratamiento farmacológico , Oocitos/efectos de los fármacos , Ovariectomía/efectos adversos , Ovario/efectos de los fármacos , Ovario/cirugía , Estudios Prospectivos , Centros de Atención Terciaria , VitrificaciónRESUMEN
Current cognitive models suggest that the processing of dynamic facial attributes, including social signals such as gaze direction and facial expression, involves the superior temporal sulcus, whereas the processing of invariant facial structure such as the individuals' identity involves the fusiform face area. Where facial attractiveness, a social signal that may emerge from invariant facial structure, is processed within this dual-route model of face perception is uncertain. Here, we present two studies. First, we investigated the explicit judgments of facial attractiveness and attractiveness-motivated behavior in patients with acquired prosopagnosia, a deficit in familiar face recognition usually associated with damage to medial occipitotemporal cortex. We found that both abilities were impaired in these patients, with some weak residual ability for attractiveness judgments found only in those patients with unilateral right occipitotemporal or bilateral anterior temporal lesions. Importantly, deficits in attractiveness perception correlated with the severity of the face recognition deficit. Second, we performed a functional magnetic resonance imaging study in healthy subjects that included an implicit and explicit processing of facial attractiveness. We found increased neural activity when explicitly judging facial attractiveness within a number of cortical regions including the fusiform face area, but not the superior temporal sulcus, indicating a potential contribution of the fusiform face area to this judgment. Thus, converging neuropsychological and neuroimaging evidence points to a critical role of the inferior occipitotemporal cortex in the processing of facial attractiveness.
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Discriminación en Psicología , Estética/psicología , Cara , Lóbulo Frontal , Prosopagnosia/fisiopatología , Lóbulo Temporal , Corteza Visual , Adulto , Mapeo Encefálico , Femenino , Lóbulo Frontal/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estimulación Luminosa , Prosopagnosia/psicología , Lóbulo Temporal/fisiología , Corteza Visual/fisiología , Percepción Visual/fisiologíaRESUMEN
The association of the antiphospholipid syndrome with malignancy has been extensively reported. Raynaud's phenomenon has also been reported to be associated with various malignancies. In this report, we describe two patients who presented with severe digital ischemia mimicking Raynaud's phenomenon. The patients were found to have antiphospholipid syndrome, and upon extensive evaluation, a diagnosis of a malignancy was made. This report highlights the importance of malignancy workup in patients with severe digital ischemia associated with antiphospholipid syndrome.
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Síndrome Antifosfolípido/etiología , Neoplasias/complicaciones , Enfermedad de Raynaud/etiología , Anciano , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Calpastatin is an intrinsic intracellular inhibitor of calpain, a Ca(2+)-dependent thiol protease. The calpain-calpastatin system constitutes one functional proteolytic unit whose presence and function has already been investigated in various cell types, but not in the egg. We have previously shown that calpain is expressed in rat eggs and is activated upon egg activation. The present study was designed to investigate the calpain-calpastatin interplay throughout the process. Western blot analysis revealed two main calpastatin isoforms, the erythrocyte type (77 kDa) and the muscle tissue type (110 kDa). By immunohistochemistry and confocal laser scanning microscopy, we demonstrated that the 110 kDa calpastatin was localized at the membrane area and highly abundant at the meiotic spindle in eggs at the first and second meiotic divisions. The 77 kDa calpastatin isoform appeared to be localized as a cortical sphere of clusters. The 110 kDa calpastatin and beta-tubulin have both been localized to the spindle of metaphase II eggs, both being scattered all through the cytoplasm following spindle disruption by nocodazole treatment, implying a dynamic interaction between calpastatin and microtubule elements. Upon egg activation, membranous calpastatin translocated to the cortex whereas cortical millimolar (m)-calpain shifted towards the membrane. Spindle calpastatin and calpain remained static. We suggest that calpastatin serves as a regulator of m-calpain. The counter translocation of m-calpain and calpastatin could serve as a means of calpain escape from calpastatin inhibition and may reflect a step in the process of calpain activation, throughout egg activation, that is required for calpain to exert its proteolytic activity.
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Proteínas de Unión al Calcio/análisis , Calpaína/análisis , Fertilización/fisiología , Óvulo/química , Partenogénesis/fisiología , Isoformas de Proteínas/análisis , Animales , Transporte Biológico , Western Blotting/métodos , Proteínas de Unión al Calcio/metabolismo , Calpaína/metabolismo , Membrana Celular/metabolismo , Femenino , Ionomicina/farmacología , Ionóforos/farmacología , Microscopía Confocal , Peso Molecular , Óvulo/metabolismo , Óvulo/ultraestructura , Isoformas de Proteínas/metabolismo , Ratas , Ratas WistarRESUMEN
Using functional magnetic resonance imaging (fMRI) we found that a noxious thermal stimulus (46 degrees C) to the hand activates the nucleus accumbens (NAc) in humans, while a non-noxious warm stimulus (41 degrees C) does not. Following the noxious stimulus, two distinct foci of decreased activation were observed showing distinct time course profiles. One focus was anterior, superior, and lateral and the second that was more posterior, inferior, and medial. The anatomical segregation may correlate with the functional components of the NAc, i.e., shell and core. The results support heterogeneity of function within the NAc and have implications for the understanding the contribution of NAc function to processing of pain and analgesia.
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Calor/efectos adversos , Imagen por Resonancia Magnética , Núcleo Accumbens/irrigación sanguínea , Dolor/patología , Adulto , Mapeo Encefálico , Peróxido de Carbamida , Análisis por Conglomerados , Combinación de Medicamentos , Lateralidad Funcional/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Núcleo Accumbens/anatomía & histología , Dolor/etiología , Dimensión del Dolor/métodos , Peróxidos/sangre , Estimulación Física/métodos , Factores de Tiempo , Urea/análogos & derivados , Urea/sangreRESUMEN
An important issue in functional MRI analysis is accurate characterisation of the noise processes present in the data. Whilst conventional fMRI noise representations often assume stationarity (or time-invariance) in the noise generating sources, such approaches may serve to suppress important dynamic information about brain function. As an alternative to these fixed temporal assumptions, we present in this paper two time-varying procedures for examining nonstationary noise structure in fMRI data. In the first procedure, we approximate nonstationary behaviour by means of a collection of simple but numerous time-varying parametric models. This is accomplished through the derivation of a locally parametric AutoRegressive (AR) plus drift model which tracks temporal covariance by allowing the model parameters to evolve over time. Before exploring time variation in these parameters, window-widths (bandwidths) that are well suited to the latent time-varying noise structure must be determined. To do this, we employ a bandwidth selection mechanism based on Stein's Unbiased Risk Estimator (SURE) criterion. In the second procedure, we describe the fMRI noise using a nonparametric method based on Functional Data Analysis (FDA). This process generates well-conditioned nonstationary covariance estimates that reflect temporal continuity in the underlying data structure whilst penalizing effective model dimension. We demonstrate both methods on simulated data and investigate the presence of nonstationary noise in resting fMRI data using the whitening capabilities of the locally parametric procedure. We evaluate the comparative behaviour of the stationary and nonstationary AR-based methods on data acquired at 1.5, 3 and 7 T magnetic field strengths and show that incorporation of time variation in the AR parameters leads to an overall decrease in the level of residual structure in the data. The FDA noise modelling technique is formulated within an activation mapping procedure and compared to the SPM (Statistical Parametric Mapping) toolbox on a cognitive face recognition task. Both the SPM and FDA methods show good sensitivity on this task, but we find that inclusion of the nonstationary FDA noise model seems to improve detection power in important task-related medial temporal regions.
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Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/estadística & datos numéricos , Algoritmos , Artefactos , Simulación por Computador , Interpretación Estadística de Datos , Cara , Humanos , Funciones de Verosimilitud , Memoria/fisiología , Modelos Estadísticos , Reconocimiento en Psicología/fisiología , Análisis de Regresión , Percepción Social , Factores de TiempoRESUMEN
This study examined what is communicated by facial expressions of anger and mapped the neural substrates, evaluating the motivational salience of these stimuli. During functional magnetic resonance imaging, angry and neutral faces were presented to human subjects. Across experimental runs, signal adaptation was observed. Whereas fearful faces have reproducibly evoked response habituation in amygdala and prefrontal cortex, angry faces evoked sensitization in the insula, cingulate, thalamus, basal ganglia, and hippocampus. Complementary offline rating and keypress experiments determined an aversive rank ordering of angry, fearful, neutral, and happy faces and revealed behavioral sensitization to the angry faces. Subjects rated angry faces, in contrast to other face categories such as fear, as significantly more likely to directly inflict harm. Furthermore, they rated angry faces as significantly less likely to produce positive emotional outcomes than the other face categories. Together these data argue that angry faces, a directly aversive stimulus, produce a sensitization response.
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Ira/fisiología , Encéfalo/fisiología , Percepción Social , Adaptación Psicológica , Adulto , Mapeo Encefálico , Interpretación Estadística de Datos , Miedo/fisiología , Felicidad , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética , Masculino , Estimulación LuminosaRESUMEN
The brain circuitry processing rewarding and aversive stimuli is hypothesized to be at the core of motivated behavior. In this study, discrete categories of beautiful faces are shown to have differing reward values and to differentially activate reward circuitry in human subjects. In particular, young heterosexual males rate pictures of beautiful males and females as attractive, but exert effort via a keypress procedure only to view pictures of attractive females. Functional magnetic resonance imaging at 3 T shows that passive viewing of beautiful female faces activates reward circuitry, in particular the nucleus accumbens. An extended set of subcortical and paralimbic reward regions also appear to follow aspects of the keypress rather than the rating procedures, suggesting that reward circuitry function does not include aesthetic assessment.
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Belleza , Cara , Imagen por Resonancia Magnética , Motivación , Recompensa , Adulto , Análisis de Varianza , Encéfalo/fisiología , Mapeo Encefálico/métodos , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , MasculinoRESUMEN
Neural responses accompanying anticipation and experience of monetary gains and losses were monitored by functional magnetic resonance imaging. Trials comprised an initial "prospect" (expectancy) phase, when a set of three monetary amounts was displayed, and a subsequent "outcome" phase, when one of these amounts was awarded. Hemodynamic responses in the sublenticular extended amygdala (SLEA) and orbital gyrus tracked the expected values of the prospects, and responses to the highest value set of outcomes increased monotonically with monetary value in the nucleus accumbens, SLEA, and hypothalamus. Responses to prospects and outcomes were generally, but not always, seen in the same regions. The overlap of the observed activations with those seen previously in response to tactile stimuli, gustatory stimuli, and euphoria-inducing drugs is consistent with a contribution of common circuitry to the processing of diverse rewards.
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Mapeo Encefálico , Encéfalo/fisiología , Juego e Implementos de Juego , Recompensa , Adulto , Amígdala del Cerebelo/irrigación sanguínea , Amígdala del Cerebelo/fisiología , Análisis de Varianza , Tronco Encefálico/fisiología , Corteza Cerebral/fisiología , Circulación Cerebrovascular , Hemodinámica , Humanos , Hipotálamo/fisiología , Imagen por Resonancia Magnética , Masculino , Núcleo Accumbens/fisiología , Vías Visuales/fisiologíaRESUMEN
We present a novel, computerized method of examining cerebral cortical thickness. The normal cortex varies in thickness from 2 to 4 mm, reflecting the morphology of neuronal sublayers. Cortical pathologies often manifest abnormal variations in thickness, with examples of Alzheimer's disease and cortical dysplasia as thin and thick cortex, respectively. Radiologically, images are 2-D slices through a highly convoluted 3-D object. Depending on the relative orientation of the slices with respect to the object, it is impossible to deduce abnormal cortical thickness without additional information from neighboring slices. We approach the problem by applying Laplace's Equation (V2psi = 0) from mathematical physics. The volume of the cortex is represented as the domain for the solution of the differential equation, with separate boundary conditions at the gray-white junction and the gray-CSF junction. Normalized gradients of psi form a vector field, representing tangent vectors along field lines connecting both boundaries. We define the cortical thickness at any point in the cortex to be the pathlength along such lines. Key advantages of this method are that it is fully three-dimensional, and the thickness is uniquely defined for any point in the cortex. We present graphical results that map cortical thickness everywhere in a normal brain. Results show global variations in cortical thickness consistent with known neuroanatomy. The application of this technique to visualization of cortical thickness in brains with known pathology has broad clinical implications.
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Algoritmos , Mapeo Encefálico/métodos , Corteza Cerebral/anatomía & histología , Imagen por Resonancia Magnética/métodos , Modelos Neurológicos , HumanosRESUMEN
This article presents and analyses several cases in which the use of the cut-off effect is useful. It starts from the fact that an anesthetic effect of homologous agents is always expressible as a function of their chain lengths and that the cut-off point is a point at which the function vanishes. We then investigate four categories of results: (i) whole body effects. (ii) Cases in which the anesthetics affect the Hodgkin-Huxley parameters of a nerve. (iii) Molecular mechanisms of anesthetic action. (iv) The physical chemistry of the anesthetic process. Our discussion shows that it is possible to incorporate these apparently remote results into one framework. It also shows how to compare results that were gathered by independent measuring methods. In some instances we suggest an interpretation, in others we suggest a further gathering of experimental data. One of the deductions indicates that a weakness exists in the lipid theories of anesthesia.