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Biomedical subjects

L Swisher

Publications and source records attributed to L Swisher.

At least 19 recordsLinked to original sources
PubMed2001

Abdominal fat distribution in pre- and postmenopausal women: The impact of physical activity, age, and menopausal status.

Age-related increases in total body fat have been reported, but the impact of menopause on abdominal fat distribution is still unclear. The purpose of this study was to determine the impact of menopausal status on abdominal fat distribution using magnetic resonance imaging (MRI). In addition, we investigated the influence of abdominal fat distribution on blood lipid profiles and leptin concentrations. Twenty-three premenopausal (PRE), 27 postmenopausal (POST), and 28 postmenopausal women on estrogen replacement therapy (ERT) had measurements of regional abdominal fat, blood lipids, and serum leptin concentrations. The women were matched for body mass index (BMI) and total body fat mass. Age and menopausal status were not found to be significant predictors of total abdominal fat, visceral fat, or subcutaneous fat, while physical activity was a significant predictor (P <.01) for total abdominal fat (R(2) =.16), visceral fat (R(2) =.32) and percent visceral fat (R(2) =.25). There was a trend for a greater visceral fat content in the POST women compared with the PRE women (2,495.0 +/- 228.4 v 1,770.4 +/- 240.8 cm(2), respectively, P =.06). The percent visceral abdominal fat was significantly lower (P <.05) in the premenopausal women than in either postmenopausal group (PRE, 23.2% +/- 1.7%; POST, 28.9% +/- 1.8%; ERT, 28.9% +/- 1.6%). Menopausal status and age did not influence any of the blood lipid values. Abdominal fat distribution was a significant predictor of cholesterol concentrations and the cholesterol/high-density lipoprotein-cholesterol (HDL-C) ratio, but only accounted for approximately 15% of the variability in these levels. Total body fat and physical activity accounted for 47% of the variability in leptin concentrations, while abdominal fat distribution, age, and menopausal status were not significant predictors. In conclusion, in early postmenopausal women, the level of physical activity accounts for the variability in abdominal fat distribution observed, while menopausal status and age do not play a significant role. ERT was not associated with additional benefits in abdominal fat distribution compared with postmenopausal women not on ERT or in the blood lipid profile in these women.

Abdomen↗
PubMed2000

Cardiac involvement in patients with acute neurologic disease: confirmation with cardiac troponin I.

BACKGROUND: Patients with acute neurologic illness often manifest findings suggestive of cardiac injury. Their proper interpretation is unclear. Accordingly, we conducted a blinded evaluation to assess the incidence of cardiac injury determined by elevations of cardiac troponin I (cTnI) in patients presenting within 24 hours of a neurologic event and to determine their short- and long-term prognostic effect. METHODS: Blood samples for measurement of cTnI levels were obtained on hospital admission and daily for 3 days and were run by immunoassay. Extensive clinical evaluations including electrocardiograms and echocardiograms were obtained from all patients; daily follow-up evaluations were performed. The clinical electrocardiographic, echocardiographic, and biochemical data were analyzed independently by blinded observers. RESULTS: Peak levels of cTnI were elevated (> or =0.4 microg/L) in 17 patients (19%) (mean + SD, 2.5 + 2.7 microg/L). All patients with elevated cTnI levels had clinical, electrocardiographic, or echocardiographic evidence of cardiac injury except those (n = 5) with minor elevations. One-year mortality was 29% (23/80). Early death (< or =30 days) accounted for 44% of total mortality (n = 10) and was significantly higher in patients with elevated cTnI levels (Wilcoxon P =.01; odds ratio, 6. 4). This difference was less marked by 1 year (Wilcoxon P =.07). CONCLUSIONS: There is a substantial prevalence of myocardial injury in patients with acute neurologic illness. Cardiac injury in this population, as in others, seems to adversely affect prognosis.

Acute Disease↗
PubMed1998

Effects of televised safety models on children's risk taking and hazard identification.

OBJECTIVE: To examine effects of televised safety models on children's willingness to take physical risks and their ability to identify injury hazards in common situations. METHODS: Sixty children, between the ages of five and eight years, were exposed to one of three TV stimulus programs: (1) a safety educational videotape, in which actors engaged in dangerous behavior, suffered injuries, and then enacted alternative safe behaviors; (2) an animated cartoon, which portrayed characters engaged in safety behaviors incidental to the main story line; or (3) the same cartoon program edited to omit the scenes depicting safety behavior. Children's willingness to take physical risks was measured before and after the TV stimulus by a series of pictorial child-relevant scenarios in which they could indicate the level of risk they would take. They also completed pretest and posttest measures of hazard identification, in which they were to identify injury hazards in several pictorial scenarios. RESULTS: Exposure to the safety educational videotape decreased children's willingness to take physical risks and increased their identification of injury hazards. Exposure to the animated cartoon with incidental safety components did not affect risk taking, but did increase ability to identify hazards. CONCLUSIONS: Findings are interpreted as evidence of observational learning and priming of thematically related knowledge by the television stimuli. Implications for safety educational curricula are discussed.

Analysis of Variance↗
PubMed1997

Another look at nonverbal rule induction in children with SLI: testing a flexible reconceptualization hypothesis.

This study focuses on the ability of preschool children with specific language impairment (SLI) to extract target regularities from recurring nonverbal stimuli. As a step beyond previous methodologies, we also assessed their ability to shift and extract other regularities after feedback indicated that their choices were no longer correct. This step was motivated by Connell and Stone's (1994) hypothesis that difficulties manifested by children with SLI in extracting nonverbal "rules" from multiple problem sets may reflect difficulties in "flexible reconceptualization," that is, in the ability to flexibility shift across regularities. Thirty 4- and 5-year-olds with SLI and 30 age-matched children developing language normally participated in a discrimination learning-shift paradigm. Findings indicated that both language groups were successful in extracting regularities and making shifts. In fact, language groups did not differ in number of regularities extracted, number of shifts completed, or trials to criterion. As a consequence, findings failed to provide evidence that children with SLI are limited in either the ability to extract nonverbal regularities or to flexibly reconceptualize them. From a larger theoretical perspective, the findings fail to support theories positing that generalized "rule-induction" deficits underlie the verbal and nonverbal impairments of SLI.

Child, Preschool↗
PubMed1997

Brief report: cross-validation of the Injury Behavior Checklist in a school-age sample.

Examined descriptive characteristics, internal validity, and convergent validity of the Injury Behavior Checklist (IBC) in a sample of 7- to 10-year-old children. Although the IBC was originally designed for use with preschool children, results of the present study showed that it has acceptable psychometric qualities for use with children as old as 9 years. The IBC shows promise as an easily administered instrument for research on psychological and behavioral mechanisms of childhood injury, as well as for individual screening for injury liability.

Child↗
PubMed1996

Reliability of performance-based clinical skill assessment of emergency medicine residents.

OBJECTIVE: To test the overall reliability of a performance-based clinical skill assessment for entering emergency medicine (EM) residents. Also, to investigate the reliability of separate reporting of diagnostic and management scores for a standardized patient case, subjective scoring of patient notes, and interstation exercise scores. METHODS: Thirty-four first-year EM residents were tested using a 10-station standardized patient (SP) examination. Following each 10-minute encounter, the residents completed a patient note that included differential diagnosis and management. The residents also were asked to read an ECG or chest x-ray (CXR) associated with each case. History, physical examination, and interpersonal skills were scored by the SPs. The patient note, CXR, and ECG readings were scored by faculty emergency physicians. Intercase reliability was determined for the residents. RESULTS: Global score reliability, Cronbach's alpha = 0.85. Reliabilities for the other components were: history, 0.77; physical examination, 0.83; and interpersonal skills, 0.80. Differential diagnosis and management reliabilities were 0.61 and 0.66, respectively. Subjective scoring of the patient note resulted in acceptable reliability for legibility (0.80), history completeness (0.80), and history organization (0.81). Physical examination completeness and organization reliabilities were 0.74 and 0.73. For ECG and CXR readings, alpha = 0.74 and 0.34, respectively. CONCLUSIONS: SPs can be used to reliably assess bedside clinical skills of EM residents. While component reliability levels are slightly lower than the global clinical skill reliability coefficient, they are still high enough to use for identification of individual strengths and weaknesses.

Clinical Competence↗
PubMed1995

Effect of implicit and explicit "rule" presentation on bound-morpheme generalization in specific language impairment.

This study addressed whether generalization of a trained bound morpheme to untrained vocabulary stems differs between children with specific language impairment (SLI) and children with normal language (NL) under two controlled instructional conditions. Twenty-five children with NL and 25 children with SLI matched for age served as subjects. Contrasts between affixed and unaffixed words highlighted the affixation "rule" in the "implicit-rule" condition. The "rule" was verbalized by the trainer in the "explicit-rule" condition. Bimodal generalization results occurred in both subject groups, indicating that generalization was not incremental. Chi-square analyses suggested that the SLI group generalized the bound morpheme less often than the NL group under the explicit-rule training condition. The findings add to those that indicate children with SLI have a unique language-learning style, and suggest that the explicit presentation of metalinguistic information during training may be detrimental to bound-morpheme generalization by preschool-age children with SLI.

Child↗
PubMed1994

Bound-morpheme skills in the oral language of school-age, language-impaired children.

Bound-morphine skills of school-age, language-impaired (LI) children were explored with three tasks designed to assess multiple dimensions of this component of language. Ten English-speaking, school-age LI children (Mean age: 10:3) and ten children with normal language (Mean age: 9:9) served as subjects. A two-way analysis of variance revealed significant group differences. Fisher a priori testing documented significant group differences for a measure of English bound-morpheme skill levels, a measure of ability to generalize English bound-morphemes to novel words, and a measure of ability to learn novel bound-morphemes attached to novel words. The findings indicate that core features of developmental language impairment in preschool children--poor ability to learn, to use, and to generalize bound-morphemes--are also present in school-age, LI children.

Child↗
PubMed1994

Learning and generalization components of morphological acquisition by children with specific language impairment: is there a functional relation?

Children with specific language impairment (SLI) have particular difficulty acquiring bound morphemes. To determine whether these morphological deficits spring from impairments of rule-induction or memory (storage/access) skills, 25 preschool-age children with normal language (NL) and 25 age-matched children with SLI were presented with a novel vocabulary and novel bound-morpheme learning task. A chi square analysis revealed that the children with SLI had significantly lower vocabulary learning levels than NL children. In addition, there was tentative evidence that a dependency relationship existed in some children between success in vocabulary learning and proficiency in generalizing a trained bound morpheme to untrained vocabulary stems. These findings are predicted by the storage/access but not the rule-induction theory of specific language impairment. They suggest that intervention targeting bound-morpheme skills acquisition in children with SLI might include attention to vocabulary development.

Child↗
PubMed1993

Language matches: illuminating or confounding? Research note.

The practice of matching younger, language-matched controls, in addition to age-matched controls, is often used in studies of language-disordered children to examine the role of "language level" on performance. However, the interpretation of the relative performance of subjects in studies using such dual control groups is problematic. Conceptual concerns arise with the use of language matches because language is a multidimensional skill that is not reflected equivalently for the language-disordered children and their language-matched controls. Furthermore, matching by language level inevitably introduces an extraneous age effect that confounds interpretation. In addition, erroneous interpretations of null findings can occur when no differences are found between language-disordered and language-matched groups.

Age Factors↗
PubMed1992

Relations among verbal and nonverbal cognitive skills in normal language and specifically language-impaired children.

This study tested the hypothesis that specifically language-impaired (SLI) children have a qualitatively different cognitive system from that of normal language (NL) children. Twenty NL and 20 SLI children between the ages of 4:2 (years:months) and 5:11 were presented with experimental language-learning measures, experimental nonverbal measures, and verbal and nonverbal norm-referenced tests. A confirmatory analysis of the covariance matrix structures of the two subject groups indicated that relations among cognitive skills differed between NL and SLI children. In addition, a planned comparison indicated that the relation between nonverbal rule-induction and novel bound-morpheme learning differed significantly between groups. The findings indicate that a "qualitative-differences" model of specific language impairment better accounts for the co-occurrence of poor verbal and poor nonverbal cognitive skills in SLI children than a "low-normal" model.

Child, Preschool↗
PubMed1992

Echolalic responses by a child with autism to four experimental conditions of sociolinguistic input.

Studies of the immediate verbal imitations (IVIs) of subjects with echolalia report that features of linguistic or social input alone affect the number of IVIs elicited. This experimental study of a child with echolalia and autism controlled each of these variables while introducing a systematic change in the other. The subject produced more (p less than .05) IVIs in response to unknown lexical words presented with a high degree of directiveness (Condition D) than in response to three other conditions of stimulus presentation (e.g., unknown lexical words, minimally directive style.) Thus, an interaction between the effects of linguistic and social input was demonstrated. IVIs were produced across all conditions, primarily during first presentations of lexical stimuli. Only the IVIs elicited by first presentations of the lexical stimuli during Condition D differed significantly (p less than .05) from the number of IVIs elicited by first presentations of lexical stimuli in other conditions. These findings viewed together suggest that the occurrence of IVIs was related, at least for this child, to an uncertain or informative event and that this response was significantly greater when the lexical stimuli were unknown and presented in a highly directive style.

Adult↗
PubMed1991

MRI findings in boys with specific language impairment.

Magnetic resonance imaging scans of specifically language-impaired (SLI) boys were examined to determine whether atypical cerebral findings could be documented in children whose primary deficits were in language skills. Clinical examination of the scans failed to reveal any visually obvious lesions or abnormalities. In contrast, measurement of the scans revealed atypical perisylvian asymmetries in most of these subjects. The distribution of perisylvian asymmetries in SLI subjects was significantly different from the distribution in controls (p less than .01). Measurement of other brain regions revealed that extraperisylvian areas were occasionally deviant in individual SLI subjects; but no one region was consistently deviant across the SLI group. Thus, only atypical perisylvian asymmetries were linked to the language disorder. These neuroanatomical findings suggest that a prenatal alteration of brain development underlies specific language impairment.

Brain Damage, Chronic↗
PubMed1990

A note on intelligence assessment within studies of specific language impairment.

The purpose of this paper is to review the procedures, reported in three journals, that researchers have adopted to evaluate the intelligence of children with specific language impairment. The results indicated that researchers used one of the following procedures: no mention of intelligence, statements of negative history for mental retardation (without further documentation), reporting cut-off scores on one or more standardized assessment instruments, reporting means on one or more standardized assessment instruments, or reporting individual test scores from such instruments. A majority of researchers adopted the procedures in the first three categories. Implications of such reporting procedures are discussed.

Child↗
PubMed1990

The initial learning of novel English words: two single-subject experiments with minority-language children.

The two single-subject, alternating treatment design experiments reported here investigated the initial learning of novel words by minority-language children acquiring English as a second language. Four Spanish- and 3 Navajo-speaking children (ages 4:11-6:3) served as subjects. The results for all children in both experiments supported the hypothesis that receptive learning of novel words in a second language would reach a pre-established criterion in fewer trials under a bilingual compared with a monolingual condition. In addition, several children in each study met the learning criterion for both first and second language words in the bilingual condition in approximately the same number of trials needed to reach criterion for the second language words in the monolingual condition. Neither study suggested that the degree of a subject's relative language dominance influenced the learning patterns. The findings are discussed in relation to the linguistic, language-related, and learning requirements of the experimental tasks.

Child↗
PubMed1990

Predictors of novel inflection learning by preschool-aged boys.

This study addressed the extent to which performance on selected verbal and nonverbal measures contributes to the prediction of inflection learning. Twenty normal boys between the ages of 4:4 (years:months) and 5:7 were presented with stories designed to teach novel vocabulary and morphological inflections. A multiple regression analysis indicated that the measure of current inflection skills accounted for nearly half of the variance in inflection learning results. In addition, performance on a posttest of vocabulary learning significantly (p less than .05) contributed to the prediction equation. Although closer analysis of the findings indicates that the relation between nonverbal rule learning and inflection learning warrants further investigation, none of the three nonverbal measures was a significant contribution to the prediction equation. The results suggest that inflection learning may be tied more to other language abilities than to nonverbal cognitive skills in normally developing boys.

Child, Preschool↗