Faculty Bibliography

This paper describes a framework for automatic brain tumor segmentation from MR images. The detection of edema is done simultaneously with tumor segmentation, as the knowledge of the extent of edema is important for diagnosis, planning, and treatment. Whereas many other tumor segmentation methods rely on the intensity enhancement produced by the gadolinium contrast agent in the T1-weighted image, the method proposed here does not require contrast enhanced image channels. The only required input for the segmentation procedure is the T2 MR image channel, but it can make use of any additional non-enhanced image channels for improved tissue segmentation. The segmentation framework is composed of three stages. First, we detect abnormal regions using a registered brain atlas as a model for healthy brains. We then make use of the robust estimates of the location and dispersion of the normal brain tissue intensity clusters to determine the intensity properties of the different tissue types. In the second stage, we determine from the T2 image intensities whether edema appears together with tumor in the abnormal regions. Finally, we apply geometric and spatial constraints to the detected tumor and edema regions. The segmentation procedure has been applied to three real datasets, representing different tumor shapes, locations, sizes, image intensities, and enhancement.

Statistical shape analysis has become of increasing interest to the neuroimaging community due to its potential to precisely locate morphological changes and thus potentially discriminate between healthy and pathological structures. This paper describes a combined boundary and medial shape analysis based on two different shape descriptions applied to a study of the hippocampus shape abnormalities in schizophrenia. The first shape description is the sampled boundary implied by the spherical harmonic SPHARM description. The second one is the medial shape description called M-rep. Both descriptions are sampled descriptions with inherent point correspondence. Their shape analysis is based on computing differences from an average template structure analyzed using standard group mean difference tests. The results of the global and local shape analysis in the presented hippocampus study exhibit the same patterns for the boundary and the medial analysis. The results strongly suggest that the normalized hippocampal shape of the schizophrenic group is different from the control group, most significantly as a deformation difference in the tail region.

This article reviews of some of the lessons in trauma psychiatry learned by the US military through wartime and other trauma experiences during the past century. Current practice in the military's employment of stress control teams is reviewed. The military's efforts to prevent and limit psychological casualties, to include the care of battle casualties and prisoners of war (POWs), are addressed.Recent experiences that have informed further, and are shaping the military's approach to managing the psychological aftermath of trauma (such as the Sept. 11, 2001, attack on the Pentagon and the current war with Iraq) are included. Guidelines developed after 9/11, and articulated in the 'Mass Violence and Early Intervention' conference are presented. Finally, current ideas on preparation for and intervention after weapons of mass destruction will be outlined

The present study investigated chemosensory gender differences by means of ratings of total nasal chemosensory intensity, unpleasantness and sensory irritation and simultaneous recordings of chemosensory event-related potentials (CSERPs) for three concentrations of the olfactory/trigeminal stimulus pyridine in 19 women and 17 men, all young adults. Results show that, compared to men, women gave higher intensity and unpleasantness ratings, in particular for the highest stimulus concentration. The gender differences in perceived intensity are reflected in the signal-to-noise ratio of the individual CSERP averages, revealing more identifiable early components (P1, N1) in women than in men. The late positive component, labeled P2/P3, displayed larger amplitudes at all electrode sites and shorter latencies at Cz, in women compared to men. The effects of increased pyridine concentration on perception (larger in women) and CSERPs (similar across gender) imply that the two measures involve partially different neural processing. CSERP component identifiability is proposed here as a general means of assessing signal-to-noise ratio of the CSERPs.

Background: Few policies designed specifically to support child and adolescent mental health exist worldwide. The absence of policy is a barrier to the development of coherent systems of mental healthcare for children and adolescents. Method: This study collected data on existing policies from international databases, WHO headquarters in Geneva, Switzerland, and in consultation with experts in child and adolescent psychiatry from around the world. A set of criteria for ranking the adequacy of these policies was developed. Results: Though no single country was found to have a mental health policy strictly pertaining to children and adolescents alone, 35 countries (corresponding to 18% of countries worldwide) were found to have identifiable mental health policies, which may have some beneficial impact on children and adolescents. Though little has been achieved worldwide in this area, there has been a significant degree of movement towards policy development in the past 10 years. The policies identified vary greatly in terms of their provisions for delivering services, initiating research, training professionals, and educating the public. Conclusions: The development of mental health policies is feasible and would substantially aid in the expansion of service systems, the institutionalisation of culturally relevant data gathering, and the facilitation of funding. (journal abstract)

There are two basic types of bacterial communication systems--those in which the signal is directed solely at other organisms and those in which the signal is sensed by the producing organism as well. The former are involved primarily in conjugation; the latter in adaptation to the environment. Gram-positive bacteria use small peptides for both types of signaling, whereas Gram-negative bacteria use homoserine lactones. Since adaptation signals are autoinducers the response is population-density-dependent and has been referred to as 'quorum-sensing'. Gram-negative bacteria internalize the signals which act upon an intracellular receptor, whereas Gram-positive bacteria use them as ligands for the extracellular receptor of a two-component signaling module. In both cases, the signal activates a complex adaptation response involving many genes

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) occurs in as many as 4 percent of adults yet it is often not recognized in clinical settings because the presenting symptoms may resemble those seen in other disorders or because symptoms may be masked by commonly comorbid conditions such as anxiety and depression. OBJECTIVE: The purpose of this study was to examine the diagnostic utility of instruments commonly used in the assessment of adults presenting with symptoms of ADHD. METHODS: We reviewed several widely used self-report and laboratory measures and empirically examined the utility of the Brown Attention-Deficit Disorder Scale for Adults (Brown ADD Scale) and the Conners Continuous Performance Test (CPT) in differentially identifying adults with ADHD and those with other Axis I disorders. RESULTS: Ninety-three adults who self-referred to the ADHD program for adults at a university medical center participated in the study. Of these, 44 had ADHD combined subtype (ADHD-CB), and 26 had ADHD, predominantly inattentive subtype (ADHD-IA). Thirty-three non-ADHD adults diagnosed with Axis I mood or anxiety disorders comprised an "Other Psychiatric" group. Rates of comorbid disorders, including substance abuse, in the ADHD groups were typical of those reported in the adult ADHD literature. Data on the Brown ADD Scale and on the CPT were available for subsets of 61 and 46 participants, respectively. Analyses showed that the ADHD-CB, ADHD-IA, and Other Psychiatric groups all received mean scores in the clinical range on the Brown ADD Scale, with a trend toward even higher elevations in the two ADHD groups. Among 12 CPT variables assessed for the three groups, the mean scores on only two variables for the ADHD-IA group were clinically elevated. Neither the Brown ADD Scale nor CPT scores evinced sufficient sensitivity and specificity to qualify them to assist in differential diagnosis of ADHD vis-a-vis other, predominantly internalizing, psychiatric disorders. CONCLUSION: The results indicate a need for closer examination of executive and adaptive functioning in adults with ADHD compared with those with internalizing disorders in order to identify features that could assist in differential diagnosis.

OBJECTIVE: Few studies have used a combination of objective and self-report measures to examine neuropsychological and behavioral functioning in parents of children with attention-deficit/hyperactivity disorder (ADHD). This study examined attention and inhibitory control in the parents of preschool children who were rated as "at risk" for developing ADHD as compared with parents of controls. METHODS: Preschool children (N=53) were divided into at risk for ADHD and control groups based on parent and teacher ratings of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition ADHD symptoms. One parent of each child was administered an identical pairs Continuous Performance Test (CPT-IP), a Go/No-Go task, and the Brown Attention-Deficit Disorder Scale for Adults. RESULTS: Parents of preschoolers at risk for ADHD showed a pattern of responding on measures of vigilance characterized by slower reaction times and increased commission errors as compared with parents of controls. There were no significant group differences on self-report measures on the Brown Attention-Deficit Disorder Scale for Adults. CONCLUSION: Parents of preschoolers at risk for ADHD appear to exhibit cognitive processing deficits that may not be evident using self-report measures. Further research is needed to more clearly identify the specific nature of these neuropsychological deficits and to determine whether they have a negative impact on their children.

OBJECTIVE: This study examines the impact of comorbidity of attention-deficit/hyperactivity disorder (ADHD) with disruptive and anxiety disorders in childhood on clinical course and outcome. We consider the relative contribution of each comorbid symptom constellation, and also their interaction, to assess the following questions: (1) Does early comorbidity with conduct disorder (CD) and anxiety disorders define specific developmental trajectories?; (2) Is comorbid anxiety disorders in childhood continuous with anxiety disorders in adolescence?; (3) Does comorbid anxiety disorders mitigate the negative behavioral outcome of youth with ADHD?; and (4) Is there an interaction between comorbid CD and anxiety disorders, when they occur simultaneously, that predicts a different outcome than either comorbid condition alone? METHOD: Thirty-two 15- to 18-year-old adolescent males, diagnosed with ADHD between 7 and 11 years of age, were re-evaluated for assessment of adolescent outcome 4.3-9.2 years later. Hierarchical regression analyses were run with each of the eight Child Behavior Checklist and Youth Self-Report problem scales, and the four anxiety symptom subscales of the Multidimensional Anxiety Scale for Children serving as outcome variables. RESULTS: Findings indicate that comorbid CD at baseline predicted parent reports of behavior problems in adolescence, while comorbid anxiety disorders in childhood predicted youth reports of anxiety and social problems. Anxiety disorders without CD did not predict poor behavioral outcome. Children with both comorbid CD and anxiety disorder had the highest levels of parent-rated symptoms on follow up. In particular, adolescent social problems were best predicted by the combination of comorbid CD and anxiety disorder in childhood. CONCLUSION: These data provide evidence that children with ADHD plus anxiety disorder do in fact have anxiety disorders, and that the combination of anxiety disorder and CD predicts a more rather than less severe course.