Robert McMahon

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BACKGROUND In a previous open-label study of hydroxyurea therapy, the synthesis of fetal hemoglobin increased in most patients with sickle cell anemia, with only mild myelotoxicity. By inhibiting sickling, increased levels of fetal hemoglobin might decrease the frequency of painful crises. METHODS In a double-blind, randomized clinical trial, we tested(More)
OBJECTIVE Patients with schizophrenia frequently present with negative symptoms and cognitive impairments for which no effective treatments are known. Agents that act at the glycine site of the N-methyl-D-aspartic acid (NMDA) glutamatergic receptor have been suggested as promising treatments for moderate to severe negative symptoms and cognitive(More)
BACKGROUND Impairments in working memory have been proposed to underlie a broad range of cognitive deficits seen in schizophrenia. Visual working memory impairments are frequently reported in schizophrenia. Investigations of visual working memory generally assume intact visual information processing, despite evidence of visual perceptual impairments in(More)
OBJECTIVES To evaluate the impact of early, mid-onset, and late maturation, as assessed by timing of menarche, on height, height velocity, weight, body mass index, and sum of skinfolds in a group of white and black girls. STUDY DESIGN The Growth and Health Study recruited 9- and 10-year-old girls from Richmond, California, Cincinnati, Ohio, and(More)
PURPOSE This report describes the development and use of two self-report methods and an objective measure to assess longitudinal changes in physical activity in a large biethnic cohort of young girls from childhood through adolescence. METHODS The NHLBI Growth and Health Study (NGHS) is a multicenter study of obesity development in 2379 black and white(More)
OBJECTIVE People with schizophrenia are characterized by a broad range of cognitive impairments. Despite appropriate treatment with conventional or second-generation antipsychotics, they continue to exhibit pronounced impairments. The current study was designed to examine the efficacy and safety of galantamine, an acetylcholinesterase inhibitor that also(More)
OBJECTIVE Electroencephalographic (EEG) synchronization in the gamma band is thought to represent a neuronal mechanism by which the brain integrates information processed in different cortical areas to build a coherent internal representation. Previous studies have reported abnormal gamma range ( approximately 40 Hz) synchronization in schizophrenic(More)
OBJECTIVE The National Heart, Lung, and Blood Institute Growth and Health Study (NGHS) is a 10-year study to investigate the development of obesity in black and white girls during adolescence and its environmental and psychosocial correlates. The purpose of this report was to examine changes in the annual prevalence rates of overweight and obesity in the(More)
This study reports evidence that individuals with schizophrenia (SC) demonstrate intact attentional selection for visual working memory (WM) storage. A group of 62 participants with SC and 55 control participants without SC were studied in a series of 5 experiments that examined the ability to use top-down and bottom-up cues to guide WM encoding, as well as(More)
The current study examined the psychometric properties of the Brief Negative Symptom Scale (BNSS), a next-generation rating instrument developed in response to the NIMH sponsored consensus development conference on negative symptoms. Participants included 100 individuals with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder who completed a(More)