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Biomedical subjects

E W Simon

Publications and source records attributed to E W Simon.

At least 19 recordsLinked to original sources
PubMed2001

Characterization of self-injurious behaviors in children and adults with Smith-Magenis syndrome.

A characteristic pattern of stereotypic and self-injurious behavior (SIB) distinguishes Smith-Magenis syndrome from many other genetic disorders. We examined the prevalence and severity of 11 specific types of SIB in 29 children and adults with Smith-Magenis syndrome. We confirmed the near universal presence of SIB in people with this disorder. The overall prevalence of SIB was found to increase with age as was the number of different types of SIB demonstrated by individuals with Smith-Magenis syndrome. The number of different types of SIB exhibited was also directly correlated with level of intellectual functioning. Our data suggest that with increasing age and ability levels, people with Smith-Magenis syndrome add to their repertoire of SIB from among a small number of specific behaviors.

Adolescent↗
PubMed2000

Body temperature as a risk factor for Alzheimer's disease.

A number of risk factors underlie the development of Alzheimer's disease. We propose low body temperature is also implicated. This is based on the belief that low temperature influences the biomechanics of the disease and promotes its development. Support for this hypothesis is found in a consideration of temperature effects on the disease process, in anecdotal observations and from our studies of people with Down syndrome.

Alzheimer Disease↗
PubMed1998

Autistic symptoms among children and young adults with isodicentric chromosome 15.

A standardized assessment of autistic symptomatology was completed for 29 children and young adults with a supernumerary isodicentric chromosome 15 (formerly known as inverted duplication 15). Although there was variability in severity, 20 individuals with an isodicentric chromosome 15 [idic(15)] had a high probability of being autistic. Eight of the 9 remaining children were under age 5 years and were more sociable than the rest of the cohort. Group characteristics such as gender and seizure presence could not explain the observed difference between older and younger individuals in our study. The natural history of isodicentric 15 syndrome remains to be shown through longitudinal work and may include an age-related risk for developing autism.

Adult↗
PubMed1997

Low glucose metabolism during brain stimulation in older Down's syndrome subjects at risk for Alzheimer's disease prior to dementia.

OBJECTIVE: Down's syndrome is characterized by the genetically programmed accumulation of substantial Alzheimer's disease neuropathology after age 40 and the development of early dementia years later, providing a unique human model to investigate the preclinical phases of Alzheimer's disease. Older nondemented adults with Down's syndrome show normal rates of regional cerebral glucose metabolism at rest before the onset of dementia, indicating that their neurons maintain function at rest. The authors hypothesized that an audiovisual stimulation paradigm, acting as a stress test, would reveal abnormalities in cerebral glucose metabolism before dementia in the neocortical parietal and temporal areas most vulnerable to Alzheimer's disease. METHOD: Regional cerebral glucose metabolism was assessed by means of positron emission tomography (PET) with [18F]fluorodeoxyglucose in eight younger (mean age = 35 years, SD = 2) and eight older (mean age = 50, SD = 7) healthy, nondemented adults with trisomy 21 Down's syndrome. PET scans were performed at rest and during audiovisual stimulation in the same scanning session. Levels of general intellectual functioning and compliance were similar in the two groups. RESULTS: At rest the two groups showed no difference in glucose metabolism in any cerebral region. In contrast, during audiovisual stimulation the older subjects with Down's syndrome had significantly lower glucose metabolic rates in the parietal and temporal cortical areas. CONCLUSIONS: Abnormalities in cerebral metabolism during stimulation appeared in the first cortical regions typically affected in Alzheimer's disease. These results indicate that a stress test paradigm can detect metabolic abnormalities in the preclinical stages of Alzheimer's disease despite normal cerebral metabolism at rest.

Acoustic Stimulation↗
PubMed1996

Facial emotion identification in males with fragile X syndrome.

Fifteen postpubertal males with fragile X syndrome (FRA(X)) and 15 non-FRA(X) males matched on IQ and age were assessed for their ability to identify the facially expressed emotions of happiness, sadness, anger, fear, disgust, and surprise. Emotions of happiness and sadness were the easiest to identify for both groups of participants. Regardless of etiology, individuals with higher IQ scores performed better at this task than did individuals with lower IQ scores. Results were consistent with findings in females having the fragile X mutation. The current study supported the notion that FRA(X) individuals are sensitive to facial emotion cues presented by others. This finding is discussed in the context of autism and gaze aversion.

Adolescent↗
PubMed1996

A case study: follow-up assessment of facilitated communication.

A 6-month follow-up of an individual reported to engage in validated facilitated communication (FC) is presented. Three main issues are addressed: the current status of the individual's FC use, the effect of food reinforcers on his communicative ability, and a comparison of FC to the Picture Exchange Communication System (PECS). Results indicated that the individual did not engage in any validated FC, that performance was equivalent on food and nonfood trials, and that PECS was the preferred mode of communication, yielding 100% accuracy in a message-passing, object identification task. Implications of these findings are discussed in the context of an individual's right to communicate by objectively validated methods.

Adolescent↗
PubMed1996

Substituting traditional antipsychotics with risperidone for individuals with mental retardation.

The use of risperidone for 10 individuals with mental retardation and mental health disturbances was reported. A case study approach was employed to delineate the course of substitution of more traditional antipsychotic medications with risperidone. At the conclusion of the study, 6 of the 10 individuals had completed the substitution protocol. All participants evidenced improvement or resolution in side effects attributed to previous antipsychotic medication, with no worsening in psychiatric or behavioral status.

Adult↗
PubMed1995

Fragile-X and Down's syndrome: are there syndrome-specific cognitive profiles at low IQ levels?

Individuals with either fragile-X syndrome or Down's syndrome with IQ scores less than 40 were assessed on the Down Syndrome Mental Status Exam. The results of the testing were examined for syndrome-specific cognitive profiles. No evidence for syndrome-specific cognitive profiles were found. These same individuals were then classified as high or low IQ, and each group was examined for IQ-level-specific profiles. Unique IQ level cognitive profiles were found. Classifying the individuals with regard to aetiology obscured IQ-level-specific strengths and weaknesses. Researchers and developers of curricula are cautioned against generalizing cognitive profiles to all IQ levels of a specific genetic syndrome.

Activities of Daily Living↗
PubMed1995

Subjective measure of quality of life.

A subjective measure of quality of life--PALS--was developed. The measure, which contains four scales (Perceived Stress, Affect, Loneliness, and Satisfaction), was normed with 100 individuals with mental retardation residing at a large facility. The PALS differs from other measures of quality of life in that it is focused exclusively upon subjective psychological dimensions that are regarded as the most relevant criteria. Potential uses and limitations of PALS were discussed.

Adult↗
PubMed1994

A naturalistic approach to the validation of facilitated communication.

By manipulating the facilitator's knowledge of a student's just-completed activity, facilitated communication ability and the extent of guiding were assessed. Seven students diagnosed with mental retardation and their facilitators participated in the study. All 7 students were purported at the start of the study to be communicating via facilitation at levels far above what was previously thought possible given their level of intellectual ability. A large degree of facilitator guiding was revealed for each of the 4 facilitators. Minimal evidence of facilitation was found for 4 of the 7 students. One of the 7 students demonstrated validated facilitated communication on two trials.

Adolescent↗
PubMed1982

Aging and the picture superiority effect in recall.

One recurrent theme in the literature on aging and memory is that the decline of memory for nonverbal information is steeper than for verbal information. This research compares verbal and visual encoding using the picture superiority effect, the finding that pictures are remembered better than words. In the first experiment, an interaction was found between age and type of material; younger subjects recalled more pictures than words while older subjects did not. However, the overall effect was small and two further experiments were conducted. In both of these experiments, the picture superiority effect was found in both age groups with no interaction. In addition, performing a semantic orienting task had no effect on recall. The finding of a picture superiority effect in older subjects indicates that nonverbal codes can be effectively used by subjects in all age groups to facilitate memory performance.

Adult↗
PubMed1982

Text recall in adulthood as a function of level of information, input modality, and delay interval.

Five stories adapted from newspaper articles were presented to subjects in three predominantly female age groups (18-32 yrs., 34-56 yrs., and 60-81 yrs.) to determine the effects of level of information, input modality (reading vs. listening), and delay interval (immediate vs. one week delay) on recall. Subject's recall protocols were scored according to the propositional system of Kintsch. Analyses indicated that the younger adults remembered the text materials better than the middle-aged and older adults under both immediate and delayed recall conditions. However, age interacted with input modality. Both the younger and middle-aged adults benefited more from the opportunity to read the material than the older adults. The results also suggested the older adults' difficulty in text processing may be related to organizational propositions of the text than in the case of the subordinate proposition of the text.

Adolescent↗
PubMed1982

Orienting task effects on text recall in adulthood.

This investigation examined the effects of orienting task-controlled processing on the text recall of younger (18 to 32 years), middle-aged (39 to 51 years), and older (59 to 76 years) adults. The participants were presented with a 500-word narrative text. Three groups performed orienting tasks (syntactic, stylistic, advice) within an incidental memory paradigm. A fourth group was asked for intentional recall. Analysis indicated a significant age by orienting task interaction. Younger adults recalled more propositions when recall was intentional or when it was preceded by a deep-orienting task than when it was preceded by a shallow-orienting task. Middle-aged and older adults recalled more propositions when recall was intentional than when it was incidental, regardless of the depth of the orienting task. There were no significant differences in intentional recall. In addition, a significant age x orienting task x propositional level interaction indicated that younger adults recalled more of the main ideas of the text following deep processing, whereas the middle-aged and older adults recalled more of these ideas following intentional processing.

Adolescent↗
PubMed1979

Primary grade children's memory for parts of speech.

Developmental differences in elementary school (kindergarten, first and second grade) children's free recall for parts of speech were investigated using sentences with normal and scrambled word order. The children were presented four sentences with normal syntax and four sentences with scrambled word order. There were significant effects of age, syntax, and rate of presentation; these replicated previous research. The unusual finding was that the kindergarten children, when presented with scrambled word strings, recalled more verbs than either the first or second grade children. It was hypothesized that this occurred because either the kindergarten children failed to detect the scrambled nature of syntaxless strings, or there is a change in the comprehension strategies which de-emphasizes the role of the verb.

Child↗
PubMed1971

Ribosomes and Polysomes in Cucumber Leaves during Growth and Senescence.

The quantity of RNA in the ribosomal fraction of the first leaf of cucumber (Cucumis sativus) increases during growth, reaches a maximum before the final fresh weight is attained, and then decreases. The main changes are in the free ribosome fraction, the quantity of membrane-bound ribosomes remaining about constant. Few 65.5S chloroplast ribosomes are present in small leaves; however, they increase in quantity rapidly during growth and form about half of the ribosomes present in the mature fully green leaf. The cytoplasmic ribosomes have a sedimentation coefficient of 77.6S. Ribonuclease-sensitive polysomes were present in leaves of all ages except possibly the very oldest. The proportion of ribosomes in polysome form decreases during growth and then remains roughly constant during senescence. Following maturation of the leaf, the rate of incorporation of (32)P into ribosomal-fraction RNA begins to decline. This decline could account for the loss of ribosomes during the early stages of senescence. The possibility that leaf ribonuclease might be responsible for the final, more rapid loss of RNA, is discussed.

Journal Article↗