PubMed Health⌕ Search

Biomedical subjects

S Weintraub

Publications and source records attributed to S Weintraub.

At least 19 recordsLinked to original sources
PubMed2005

Responsiveness of the aging circadian clock to light.

The present study assessed whether advances in sleep times and circadian phase in older adults might be due to decreased responsiveness of the aging circadian clock to light. Sixteen young (29.3+/-5.6 years) and 14 older adults (67.1+/-7.4 years) were exposed to 4h of control dim (10lux) or bright light (3500lux) during the night. Phase shifts of the melatonin rhythm were assessed from the nights before and after the light exposure. Bright light delayed the melatonin midpoint in both young and older adults (p<0.001). Phase delays for the older subjects were not significantly different from those of the young subjects for either the bright or dim light conditions. The magnitude of phase delays was correlated with both sleep offset and phase angle in the older, but not the younger subjects. The present results indicate that at light intensities commonly used in research as well as clinical practice older adults are able to phase delay to the same extent as younger subjects.

Adaptation, Physiological↗
PubMed2005

Primary progressive aphasia: reversed asymmetry of atrophy and right hemisphere language dominance.

Primary progressive aphasia (PPA) is almost always associated with asymmetrical left hemisphere degeneration. The authors report that right hemisphere atrophy in a patient with PPA was associated with atypical right hemisphere dominance for language. This suggests that neuronal damage in PPA is therefore tightly linked to the underlying anatomy of the language network.

Aphasia, Primary Progressive↗
PubMed2004

[Magnetic resonance studies in Alzheimer's dementia. What routine scanning shows].

Magnetic resonance images of the brain acquired in relationship to the commissural plane have been analyzed in twenty cases classified as Probable Alzheimer's disease (Pr. AD). These examinations have been compared to normal aged matched subjects. All examinations have been made in strict correlation with the planes defined by Talairach and Tournoux (1988). The analysis of brain cortical damage was made by evaluating the sulci of the brain mainly on coronal sections correlated with simultaneous image review of the same area on the two other orthogonal planes. In Pr. AD, an asymmetric atrophic pattern was found mainly on the following areas: amygdaloid nucleus, para hippocampal gyrus, hippocampus, areas 22 and 21, temporal pole, insula, dorso frontal cortex, angular gyrus, superior parietal lobule. The primary motor and visual areas were normal in all cases.

Aged↗
PubMed2003

Possible association of the tau H1/H1 genotype with primary progressive aphasia.

The authors screened for tau gene mutations and polymorphisms to determine whether genetic variation at or near the tau locus contributes to the development of primary progressive aphasia (PPA). No mutations were detected in 25 patients with PPA. However, a significant overrepresentation of the tau H1/H1 genotype, also found in progressive supranuclear palsy and corticobasal degeneration, was found in the PPA group. Whether tau haplotypes have a primary causal role or whether they affect the topology of neurodegeneration remains to be determined.

Adult↗
PubMed2001

Dynamic allocation of attention in aging and Alzheimer disease: uncoupling of the eye and mind.

CONTEXT: Visual attention can be distributed focally, in the direction of gaze, or globally, throughout the extrapersonal space. Aging, and especially Alzheimer disease (AD), may influence global attention, resulting in shifts of gaze to attend to the global workspace. OBJECTIVE: To determine if subjects who have AD and cognitively intact older subjects shift their gaze more often than young subjects while viewing a dynamic stimulus that emphasizes global attention. DESIGN: Experimental study of eye fixation patterns in response to a simulated driving scene with stationary and moving distractors. SETTING: Urban, medical school, National Institute on Aging-funded Alzheimer's Disease Center. PARTICIPANTS: Thirteen subjects with mild probable AD, 13 age-comparable cognitively intact older control subjects, and 11 young control subjects. MAIN OUTCOME MEASURE: Proportion of eye fixations within and outside of a central region of interest encompassing the "road" surface. RESULTS: Young controls made significantly more eye fixations (mean number of eye fixations, 47.5) than either of the other 2 groups (older controls mean, 33.2; patients with AD mean, 32.2). However, 76% of their fixations remained within the central region of interest. Older controls and subjects with AD made proportionately fewer fixations within this region (48% and 49%, respectively) than young controls and moved their eyes more often to the periphery but did not differ from one another. CONCLUSIONS: Young controls maintain central eye position regardless of peripheral distraction. Older controls move their eyes to the periphery, presumably to widen the window of attention. Subjects with mild AD did not experience an additional disadvantage beyond that associated with aging.

Adult↗
PubMed2000

Emotional curiosity: modulation of visuospatial attention by arousal is preserved in aging and early-stage Alzheimer's disease.

Previous studies have shown that Alzheimer's disease, even in its early stages, decreases novelty-seeking behaviors (curiosity) and impairs the shifting of spatial attention to extrapersonal targets. In this study, early-stage probable Alzheimer's disease patients (PRAD) and young and aging controls were shown pairs of visual scenes, some of which contained emotionally-arousing material, while eye movements were recorded under free viewing conditions. In all three subject groups, emotionally-arousing scenes attracted more viewing time and also became the preferential target of the initial visual orientation. Our findings suggest that the arousing properties of sensory stimuli may overcome some of the AD-related impairments in the distribution of attention to extrapersonal targets. These results may have implications for interventions aimed at improving the cognitive symptoms of PRAD.

Adult↗
PubMed2000

Alterations of visual search strategy in Alzheimer's disease and aging.

Visual search, characterized by eye fixation patterns, was examined in 8 patients with Alzheimer's disease (AD), 8 cognitively intact, age-matched individuals, and 8 young control participants as they searched for a number among a nonlinear array of letters on a large computer screen. Among the 3 groups, target detection accuracy differed and detection time increased linearly. There were more fixations, and fixation duration was significantly longer in the AD patients than in the other 2 groups. These factors contributed to the lengthening of target detection time. This qualitative difference in the architecture of visual search between AD and aging may reflect a specific deficit in the disengagement of visual spatial attention, a prolongation of saccade initiation, or inefficiency in planning a search strategy.

Adult↗
PubMed2000

Three words three shapes: A clinical test of memory.

Three Words - Three Shapes was designed as an easy "bedside" test for elderly patients that assesses verbal and nonverbal memory within the same modality. In the present study, it was administered to patients with probable Alzheimer's disease (PRAD), a control group of non-demented older subjects (NC) and a group of patients with Korsakoff's amnesia (KA). Incidental recall and several other measures of learning, retention and recognition differentiated control from PRAD and KA subjects. PRAD and KA subjects' performance was similar, but there were some material-specific interactions. This test is relatively easy and some of the derived measures could prove useful in staging amnesia progression beyond the earliest stages of PRAD when more difficult tests yield floor effects.

Aged↗
PubMed2000

Direct measurement of the lumped constant for 2-deoxy-[1-(14)C]glucose in vivo in human skeletal muscle.

The lumped constant (LC) is used to convert the clearance rate of 2-deoxy-D-glucose (2-DG(CR)) to that of glucose (Glc(CR)). There are currently no data to validate the widely used assumption of an LC of 1.0 for human skeletal muscle. We determined the LC for 2-deoxy-[1-(14)C]glucose (2-DG) in 18 normal male subjects (age, 29+/- 2 yr; body mass index, 24.8+/-0.8 kg/m(2)) after an overnight fast and during physiological (1 mU x kg(-1) x min(-1) insulin infusion for 180 min) and supraphysiological (5 mU x kg(-1) x min(-1) insulin infusion for 180 min) hyperinsulinemic conditions. Normoglycemia was maintained with the euglycemic clamp technique. The LC was measured directly with the use of a novel triple tracer-based method. [3-(3)H]glucose, 2-[1-(14)C]DG, and [(12)C]mannitol (Man) were injected as a bolus into the brachial artery. The concentrations of [3-(3)H]glucose and 2-[1-(14)C]DG (dpm/ml plasma) and of Man (micromol/l) were determined in 50 blood samples withdrawn from the ipsilateral deep forearm vein over 15 min after the bolus injection. The LC was calculated by a formula involving blood flow calculated from Man and the Glc(CR) and 2-DG(CR). The LC averaged 1.26+/-0.08 (range 1.06-1.43), 1.15+/-0.05 (0.99-1.39), and 1.18+/-0.05 (0.97-1.37) under fasting conditions and during the 1 and 5 mU x kg(-1). min(-1) insulin infusions (not significant between the different insulin concentrations, mean LC = 1.2, P<0.01 vs. 1.0). We conclude that, in normal subjects, the LC for 2-DG in human skeletal muscle is constant over a wide range of insulin concentrations and averages 1. 2.

Adult↗
PubMed1999

Neurological involvement in a child with the wrinkly skin syndrome.

In 1973, a syndrome was reported comprising of wrinkled skin over the dorsum of hands, feet, and abdomen, reduced skin elasticity, skeletal involvement, craniofacial anomalies, mental and developmental delay, and failure to thrive. Only nine cases have been reported. Three additional cases with deletion 2q32 show some manifestations of this syndrome. We present another child with this syndrome with prominent neurological involvement manifested by mental retardation, microcephaly, and an episode of status epilepticus.

Campylobacter Infections↗
PubMed1998

Lissencephaly associated with congenital hypomyelinating and axonal neuropathy.

The authors describe an 11-year-old male with severe mental retardation, hypotonia, and arthrogryposis, with both type I lissencephaly and a congenital peripheral neuropathy, probably hypomyelinating with axonal involvement. To the best of the authors' knowledge, this is the first report involving the co-occurrence of these two developmental disorders. A viral, metabolic, or nutritional insult acting throughout the period of migration and myelination or a contiguous gene linkage are possible explanations for this disorder.

Axons↗
PubMed1998

Are there sex differences in neuropsychological functions among patients with schizophrenia?

OBJECTIVE: Studies of sex differences in neuropsychological performance in schizophrenia report inconsistent results, due in part to methodological artifacts. The study presented here was specifically designed to examine sex differences in neuropsychological performance. It was hypothesized that schizophrenic women would exhibit fewer neuropsychological deficits than schizophrenic men and that their performance would be more similar to that of normal women than schizophrenic men's performance would be to that of normal men. METHOD: Thirty-one outpatients with DSM-III-R-defined schizophrenia were systematically sampled from an extensive service network serving a large urban catchment area for seriously mentally ill persons. Twenty-seven normal comparison subjects were matched within sex on the basis of age, parental socioeconomic status, ethnicity, and handedness. An extensive neuropsychological test battery was administered, and multivariate analysis of variance was used to test for the effects of sex and group and sex-by-group interactions. RESULTS: Male patients were significantly impaired across all functions in comparison with normal male subjects and on tests of attention, verbal memory, and executive functions in comparison with female patients. Female patients performed significantly worse than female normal comparison subjects only on tests of attention, executive functions, visual memory, and motor functions. CONCLUSIONS: The findings suggest that women with schizophrenia may be less vulnerable to particular cognitive deficits, especially those involving verbal processing, than schizophrenic men.

Adult↗
PubMed1998

Dopamine agonists reorient visual exploration away from the neglected hemispace.

OBJECTIVE: To study the effects of bromocriptine, a dopamine agonist, on visual search. BACKGROUND: The anatomic substrate of spatial attention takes the form of a distributed network with interconnected cortical (frontal, parietal, and cingulate) and subcortical (striatal and thalamic) components. Dopamine appears to exert a modulatory effect on the function of this network. METHODS: Seven consecutive right-handed subjects with right-sided cerebral lesions were studied using a computerized target search paradigm. Eye movements were recorded. RESULTS: Bromocriptine caused the subjects to spend more time exploring the ipsilesional hemispace and therefore increased the relative neglect of the contralesional left hemispace. However, target detection accuracy did not change. Bromocriptine thus had a differential impact on the exploratory-motor versus sensory-perceptual components of directed attention. CONCLUSIONS: Our results show that bromocriptine may worsen some aspects of hemispatial neglect in patients with lesions that include the postsynaptic components of ascending dopaminergic pathways.

Adult↗
PubMed1997

Deficient antisaccades in the social-emotional processing disorder.

We investigated whether adolescents and adults with the developmental social-emotional processing disorder (SEPD) exhibit deficits in visual attention, as measured by eye movements, when compared with dyslexic and normal control subjects. On the antisaccade task, subjects with SEPD made more errors than either control group and were the only group to show a decrease in performance accuracy compared with prosaccade. This deficit in inhibiting reflexive shifts of attention and gaze suggests that individuals with SEPD have dysfunction of the prefrontal component of the right hemisphere dominant network for spatially directed attention.

Adolescent↗
PubMed1997

Apolipoprotein E genotypes in primary progressive aphasia.

We obtained apolipoprotein E genotyping in a population of 12 consecutive patients who fulfilled rigorous criteria for the clinical diagnosis of primary progressive aphasia (PPA). The allele frequencies were 4% for E2, 83% for E3, and 13% for E4. This pattern of allele distribution was significantly different from the pattern seen in groups of patients either with the clinical diagnosis of probable Alzheimer's disease (PRAD) or the histopathologic diagnosis of Alzheimer's disease (AD). The E4 allele frequency in the group of patients with PPA was in the range seen in control populations and was much lower than the one reported in populations of patients with PRAD or AD. The E4 allele is therefore not a significant risk factor for developing PPA. These results provide neurobiological support for the syndromic distinction of PPA from PRAD and are in keeping with neuropathologic evidence showing that the vast majority of patients with PPA do not have the histopathology of AD. Although we do not yet have neuropathologic information on our patients, these results indicate that the clinical diagnosis of PPA has biological validity in that it identifies a population that is genetically different from the population of patients with a clinical diagnosis of PRAD.

Adult↗
PubMed1996

Absence of neglect for mental representations during the intracarotid amobarbital procedure.

BACKGROUND: The unilateral suppression of right-hemisphere electrophysiological activity during the intracarotid amobarbital procedure results in left neglect on visuomotor search tasks. OBJECTIVE: To investigate whether right-hemisphere inactivation during the intracarotid amobarbital procedure also results in left neglect of the mental representation of a remembered scene. DESIGN: Before the intracarotid amobarbital procedure, 16 subjects were asked to draw a room from their homes. Following the right-hemisphere injection, subjects wee tested for the presence of left neglect of extrapersonal space using a Random Letter Cancellation Test. To test for neglect of the mental representation of a remembered scene, they were then asked to report items from the room they had drawn. RESULTS: While 10 of the 16 subjects showed left neglect on the Random Letter Cancellation Test, only one subject showed left neglect of the mental representation. The other 15 subjects recalled approximately equal numbers of items from the left and the right hemispaces. CONCLUSIONS: These results replicate previous findings of left neglect of extra personal space during the intracarotid amobarbital procedure and fail to show concurrent neglect for mental representations. They provide further evidence for the multiplicity and dissociability of the behavioral manifestations of neglect.

Amobarbital↗