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Biomedical subjects

R D Morris

Publications and source records attributed to R D Morris.

At least 19 recordsLinked to original sources
PubMed2001

Linking sight and sound: fMRI evidence of primary auditory cortex activation during visual word recognition.

We describe two studies that used repetition priming paradigms to investigate brain activity during the reading of single words. Functional magnetic resonance images were collected during a visual lexical decision task in which nonword stimuli were manipulated with regard to phonological properties and compared to genuine English words. We observed a region in left-hemisphere primary auditory cortex linked to a repetition priming effect. The priming effect activity was observed only for stimuli that sound like known words; moreover, this region was sensitive to strategic task differences. Thus, a brain region involved in the most basic aspects of auditory processing appears to be engaged in reading even when there is no environmental oral or auditory component.

Adolescent↗
PubMed2000

Social problem solving in children with acquired brain injuries.

OBJECTIVES: To assess the performance of children with acquired brain injuries (ABIs) on a measure of social problem solving and to examine the relationships between participant characteristics and performance on the Social Knowledge Interview (SKI) and between parent-reported child behavior and performance on the SKI. DESIGN: Between-group comparisons using correlational analyses, matched pairs t-tests, and analysis of covariance (ANCOVA). PARTICIPANTS: Thirty-one children 6-12 years old with ABI and 31 control participants, matched on age and sex. MAIN OUTCOME MEASURE: The SKI, a measure of social problem-solving skills. RESULTS: Using matched pairs t-tests and ANCOVA, groups were compared on several SKI measures, including the number of unique responses generated for each problem scenario, the quality of those responses, and the ability to select the best response from a set of alternatives. When equated for socioeconomic status (SES), ABI and control participants performed similarly on the SKI; however, a trend for children with ABI to generate more assertive responses was observed. Performance on the SKI was positively correlated with IQ and related to parent-reported adaptive behavior. In children with ABI, performance was also related to primary lesion location and treatment regimen. CONCLUSIONS: Children with ABI are as capable of judging the appropriateness of behavior and generating response options on an analog measure of social problem solving as were their typically developing peers. However, those individual children with ABI who are more likely to have social problems may be identified by the qualitative aspects of their responses on analog tasks. These findings have implications for the identification of children with social skills deficits following ABI and for the development of effective rehabilitation strategies.

Brain Injuries↗
PubMed1998

Parent assessment of psychological and behavioral functioning following pediatric acquired brain injury.

OBJECTIVE: Compare the measured prevalence rate of psychopathology and behavior disorders in 29 children with acquired brain injuries using four parent-report instruments. METHOD: Two questionnaires, the Child Behavior Checklist (CBCL) and the Personality Inventory for Children (PIC-R) and two interview measures, the Diagnostic Interview for Children and Adolescents (DICA-R) and the Vineland Adaptive Behavior Scales (VABS), were completed following injury or diagnosis. RESULTS: The DICA-R identified the highest prevalence of anxiety disorders and acting-out behaviors, whereas the CBCL identified the lowest prevalence. Opposite results were found within the domain of attentional problems. Interview measures were more concordant for global psychological impairment than were questionnaires. DISCUSSION: Discordant findings across measures are discussed in terms of type of disorder, classification model, response format, item characteristics, and scaling.

Adolescent↗
PubMed1998

Carbon monoxide and hospital admissions for congestive heart failure: evidence of an increased effect at low temperatures.

The combined effects of carbon monoxide and low temperature on daily variation in hospital admissions for congestive heart failure (CHF) were examined for a 4-year period in Chicago, Illinois. Medicare hospital admissions for CHF were analyzed as a function of the maximum hourly temperature, maximum hourly levels of carbon monoxide (CO), and other criteria pollutants in Chicago for each day of the 4-year period (1986-1989). The regression analyses for the time series were conducted using single and multipollutant models with interaction terms and adjustments for weather, weekly cycles, seasonal effects, and secular trend. The data were also grouped into three temperature ranges, <40 degrees, 40 degrees-75 degrees, and >75 degrees F, and the relationship between CO and CHF admissions was evaluated for each range. For the 4-year time series, the CO level was positively associated with hospital admissions for CHF in the single pollutant and multipollutant models after adjustment for seasonal effects and weather pattern. The relative risks of hospital admissions for CHF in Chicago associated with the 75th percentile of exposure to CO in the high, medium, and low temperature ranges were 1.02 [95% confidence interval (CI), 0.95-1.10], 1.09 (CI, 1.04-1.14), and 1.15 (CI, 1.09-1.22), respectively. In these data, the effect of CO on hospital admissions for CHF was temperature dependent, with the magnitude of the effect increasing with decreasing temperature. This synergy may help to explain the association between ambient CO and CHF admissions demonstrated in other studies.

Air Pollutants↗
PubMed1998

Did Milwaukee experience waterborne cryptosporidiosis before the large documented outbreak in 1993?

The patterns of incidence and pathways of spread for cryptosporidiosis are poorly understood. In this study, we explored the possibility that drinking water caused significant waterborne cryptosporidiosis in Milwaukee well before the massive documented outbreak in April 1993. We generated time series of daily counts of emergency room visits and hospital admissions for gastroenteritis in Milwaukee using the billing records of the Medical College of Wisconsin for January 1, 1992, through May 3, 1993. The Milwaukee Water Works provided us with data on drinking water turbidity for the same period. The service area of the South Plant experienced a sharp rise in turbidity just before the outbreak. During the outbreak period, gastroenteritis events were most strongly associated with turbidity at a lag of 7 days in children and 8 days in adults. It is reasonable to conclude that these lag times reflect the incubation period of Cryptosporidium. During the 434 days before the outbreak, gastroenteritis events were most strongly associated with turbidity at a lag of 8 days among children and 9 days among adults in the service area of the North Plant, the plant that experienced the highest effluent turbidity during this period. These findings are consistent with the conclusion that waterborne cryptosporidiosis was occurring in Milwaukee for more than a year before the documented outbreak.

Adult↗
PubMed1997

Cognitive-behavioral remediation of problem solving deficits in children with acquired brain injury.

The inability to problem solve can have a deleterious impact on a student's academic performance and social adjustment. Children with an acquired brain injury (ABI) are at risk for deficits in problem solving skills. This case study and series of multiple baseline experiments examined the effects of a multi-component cognitive-behavioral training program on the remediation of problem solving deficits in five children with ABI. Results indicated that the training program resulted in a substantial decrease in errors on a computerized problem solving task used to monitor problem solving performance during baseline and treatment. In addition, significant improvements were found on two of four standardized measures of problem solving abilities. Finally, students, parents and teaching staff reported a high degree of satisfaction with and generalization of the training program.

Brain Injuries↗
PubMed1997

Additive impact of in-hospital cardiac arrest on the functioning of children with heart disease.

OBJECTIVE: This study examined the impact of a sudden cardiac arrest (CA) on the neurodevelopmental and adaptive functioning of young children with congenital heart disease (CHD). METHODOLOGY: Sixteen children with CHD who had sustained an in-hospital CA were compared with a medically similar group of children with CHD who had not incurred a CA. The contribution of CA, disease severity, and family socioeconomic status on the prediction of developmental outcome variables was evaluated. RESULTS: Children in the CA group displayed more impairments in general cognitive, motor, and adaptive behavior functioning as well as greater disease severity as measured by a cumulative medical risk index. With respect to all children in the study, a higher socioeconomic status was related to higher scores on cognitive functioning, lower levels of child maladjustment, and lower levels of stress within the parent-child relationship. Although the occurrence of a CA alone did not contribute to the prediction of outcome measures, a significant interactional effect between CA and cumulative medical risk index was found. Specifically, among children who had incurred a CA, as disease severity increased, decrements in abilities were observed. Few significant correlations between specific CA-related variables (eg, length of CA) and outcome indices were found. CONCLUSIONS: Results from this study indicate that the impact of cardiac arrest on neuropsychological functioning may be mediated by the child's overall disease severity. These findings have implications for the identification of CA survivors at greatest risk for developmental difficulties.

Case-Control Studies↗
PubMed1996

Temporal variation in drinking water turbidity and diagnosed gastroenteritis in Milwaukee.

Daily counts of diagnosed gastroenteritis (gastrointestinal events) in Milwaukee County, Wisconsin, from January 1992 through April 1993 were compared with reported daily turbidity from the two drinking water treatment plants serving the county. Turbidity in both plants was associated with an increased number of gastrointestinal events even after exclusion of a major documented outbreak of cryptosporidiosis. During the 434-day period prior to the outbreak, an increase in turbidity of 0.5 nephelometric turbidity units at one of the plants was associated with relative risks for gastrointestinal events of 2.35 among children (95% confidence interval [CI] = 1.34, 4.12) and 1.17 among adults (95% CI = 0.91, 1.52).

Adolescent↗
PubMed1995

Family and illness predictors of outcome in pediatric brain tumors.

Investigated the prediction of cognitive and behavioral outcomes in 63 children with heterogenous brain tumors. Hierarchical multiple regression analyses were used to determine how family-related variables added to the prediction of children's outcome over and above illness measures. The best predictors of children's behavior problems and adaptive behavior were family and demographic variables, whereas the best predictors of achievement were illness and demographic variables. A combination of family and illness variables, however, was the best predictor of intellectual functioning. In addition to identifying specific predictors of cognitive and behavioral outcome in children with brain tumors, these results lend initial support for the inclusion of contextual factors such as family stress, maternal coping, number of parents in the home, and family SES measures in studies of how disease factors affect outcomes in pediatric brain tumor patients.

Adaptation, Psychological↗
PubMed1995

Drinking water and cancer.

Any and all chemicals generated by human activity can and will find their way into water supplies. The types and quantities of carcinogens present in drinking water at the point of consumption will differ depending on whether they result from contamination of the source water, arise as a consequence of treatment processes, or enter as the water is conveyed to the user. Source-water contaminants of concern include arsenic, asbestos, radon, agricultural chemicals, and hazardous waste. Of these, the strongest evidence for a cancer risk involves arsenic, which is linked to cancers of the liver, lung, bladder, and kidney. The use of chlorine for water treatment to reduce the risk of infectious disease may account for a substantial portion of the cancer risk associated with drinking water. The by-products of chlorination are associated with increased risk of bladder and rectal cancer, possibly accounting for 5000 cases of bladder cancer and 8000 cases of rectal cancer per year in the United States. Fluoridation of water has received great scrutiny but appears to pose little or no cancer risk. Further research is needed to identify and quantify risks posed by contaminants from drinking-water distribution pipes, linings, joints, and fixtures and by biologically active micropollutants, such as microbial agents. We need more cost-effective methods for monitoring drinking-water quality and further research on interventions to minimize cancer risks from drinking water.

Humans↗
PubMed1995

Ambient air pollution and hospitalization for congestive heart failure among elderly people in seven large US cities.

OBJECTIVES: Preexisting data sets were used to investigate the association between hospital admissions for congestive heart failure and air pollutants. METHODS: Medicare hospital admissions data, ambient air pollution monitoring data, and meteorological data were used to create daily values of hospital admissions for congestive heart failure, maximum hourly temperature, and maximum hourly levels of carbon monoxide, nitrogen dioxide, sulfur dioxide, and ozone. Data were compiled for each of seven cities (Chicago, Detroit, Houston, Los Angeles, Milwaukee, New York, and Philadelphia) for 1986 through 1989. Single-pollutant and multipollutant models with adjustments for temperature, seasonal effects, and weekly cycles were used in conducting negative binomial regression analyses. RESULTS: Ambient carbon monoxide levels were positively associated with hospital admissions for congestive heart failure in the single-pollutant and multipollutant models for each of the seven cities. The relative risk of hospital admission for congestive heart failure associated with an increase of 10 ppm in carbon monoxide ranged from 1.10 in New York to 1.37 in Los Angeles. CONCLUSIONS: Hospital admissions for congestive heart failure exhibited a consistent association with daily variations in ambient carbon monoxide. This association was independent of season, temperature, and other major gaseous pollutants.

Age Distribution↗
PubMed1994

Predicting injury risk in adolescent football players: the importance of psychological variables.

Explored the relationship of anger/aggression, attention, and stressful life events to injury while addressing the methodological limitations of prior studies. An additional objective was to determine whether the relationship of stressful life events to injury is mediated either by anger (directed either inward or outward) or by impaired attention, either vigilant (broad, external) or focused (narrow, internal). At the beginning of summer practice, 120 first-string high school football players completed measures of anger (Framingham Anger Scale), vigilant attention (Symbol Digit Modalities test), focused attention (Pursuit subtest, MacQuarrie Test of Mechanical Ability), and stressful life events (abbreviated form of the Social Readjustment Rating Scale as modified for use with adolescents by Coddington, 1972). Players were then followed through one season to identify those injured. Logistic regression indicated that high anger directed outward (p < .05) and low focused attention (p < .01) increased injury risk, while stressful life events and vigilant attention interacted. Injury risk was elevated when recent stress was present (p < .05), and increased as vigilance decreased, suggesting that stressful life events elevate injury risk by reducing vigilance.

Adolescent↗
PubMed1994

Meta-analysis in cancer epidemiology.

Meta-analysis has seen increasing use as a tool in epidemiology over the past five years. Although this method is relatively well accepted for use in clinical trials, its use has proved somewhat more controversial in epidemiology. If meta-analysis is viewed as an evolutionary improvement over the review article, it may become more widely acceptable. Meta-analysis should incorporate the concern for study quality and differences in study design seen in classic review articles with the concern for rigor, objectivity, and quantitative precision characteristic of meta-analysis. Available tools for consideration of differences among studies are described with several examples from the literature. The extent to which various methods are used in published meta-analyses is described. Methods for assessing publication bias, and tools for combining dose-response data, are discussed also. Evaluation of risk factors and protective factors for cancer must be based on the weight of the evidence. Tools such as meta-analysis are essential if we are to interpret the vast number of completed studies in cancer epidemiology.

Alcohol Drinking↗
PubMed1994

Geographic variability in hospital admission rates for respiratory disease among the elderly in the United States.

BACKGROUND: The elderly represent a susceptible subpopulation that experiences disproportionate levels of morbidity and mortality from respiratory disease. As a consequence, they are frequently hospitalized for these conditions. Evaluating the geographic distributions of these hospital admissions can provide useful insights concerning patterns in incidence and medical care for respiratory diseases. METHODS: All hospital admissions for pneumonia, acute respiratory infections, asthma, and chronic obstructive pulmonary disease from the United States for a 6-year period (1984 through 1989) were identified using Medicare admissions records. Age-, race-, and sex-standardized annual admission rates were calculated for each county and spatial clustering of disease specific rates was evaluated using Moran's I statistic. Ecologic analyses were conducted using multiple regression procedures with county-specific measures of average annual temperature, average income, household crowding, median educational level, population density, physicians per capita, and hospital beds per capita together with surrogate measures of cigarette consumption and occupational exposures as predictor variables. RESULTS: Hospital admission rates in the elderly for all four categories of respiratory disease showed marked regional elevations (p < 0.0001), particularly in the southeast and the northern plains states. Low median education level, low per capita income, and household crowding were all associated with elevated hospital admission rates. Surrogate measures of cigarette consumption were strongly associated with hospital admissions in all four disease groups. Hospital beds per capita demonstrated positive associations with hospital admissions, but the number of physicians per capita exhibited consistent inverse relationships with hospital admissions. CONCLUSIONS: Hospital admission rates for respiratory diseases among the elderly show marked geographic variation and are associated with regional indicators of socioeconomic status, availability of medical resources, occupational lung disease rates, and smoking.

Aged↗
PubMed1993

Aggregation of existing geographic regions to diminish spurious variability of disease rates.

The availability of large data sets together with the growth in power and storage capabilities of computers have made the analysis of the spatial distribution of disease rates an increasingly important tool in public health research. Use of existing geographic divisions or groupings tends to result either in unstable estimates of disease rates if the corresponding populations are small or in loss of spatial resolution if the areas are unnecessarily large. This paper describes a computer algorithm for combining existing geographic areas into regions with populations large enough to diminish spurious variability in disease rates while limiting the loss in resolution. The method is demonstrated using Medicare hospital admissions data for pneumonia and central nervous system cancer. Disease rates were calculated for both predefined regions and those generated by the algorithm and their frequency distributions were compared. The algorithm produces more stable rates over a variety of diseases and provides substantially more flexibility than the use of predefined aggregations.

Black or African American↗
PubMed1993

Perception of human chimeric faces by chimpanzees: evidence for a right hemisphere advantage.

The aim of this study was to investigate hemispheric advantages in the processing of human chimeric faces by chimpanzees using a free-vision task developed by Levy, Heller, Banich, and Burton (1983a). Subjects were taught a visual discrimination in which they were to select the human face that appeared "happiest" when paired with its neutral counterpart. After reaching criterion, chimeric faces were substituted as test trials, and the face the subjects selected was recorded. On 62% of the trials, three chimpanzee subjects selected the face in which the smiling half fell in the left hemispatial field. Familiarity factors appear to have accounted for some of the observed findings. We believe this is the first evidence for hemispheric advantages in the perception of human faces by great apes.

Animals↗
PubMed1993

Assessment of hand preference in two language-trained chimpanzees (Pan troglodytes): a multimethod analysis.

The nonhuman primate literature concludes that monkeys and apes do not exhibit handedness preferences at the population level. This discrepancy between human and nonhuman primate findings may be due to differences in the methods of assessment of handedness, lack of reliability between various measures of handedness, and a paucity of studies involving great apes. This paper presents the results of extensive hand preference studies with two language-trained chimpanzees (Pan troglodytes). Both naturalistic and experimental paradigms are described. In particular, various methodologic factors involved in handedness assessment, including the use of a hand preference measure previously used with human subjects were examined. Both chimpanzees exhibited a right-hand preference for fine motor tasks requiring manual dexterity.

Animals↗