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Biomedical subjects

D W Evans

Publications and source records attributed to D W Evans.

At least 37 records · Page 2Linked to original sources
PubMed1999

[School health education in California. The policies and contents of The Health Framework].

This paper introduces school health education activities in California. We focus on The Health Framework published by the California Department of Education. It describes the policies, objectives, and contents of health education for California public schools. This framework emphasizes health literacy for students and a comprehensive school health system that supports effective health education and make health an important priority at the school. The nine content areas presented by the framework describe health concepts, skills, and behaviors important for students. We analyzed this framework and its background including the trend of school health education in the United States and other health education related activities in California. Finally we compared the framework with school health education in Japan.

Adolescent↗
PubMed1999

Neuropsychological models of childhood obsessive-compulsive disorder.

Neuropsychological models of obsessive-compulsive disorder (OCD) point to a fairly consistent pattern of deficits in response inhibition, visual memory, and visuoperceptual functioning. However, little is known about these areas of functioning with respect to child onset OCD because most studies to date have focused on adults. Data from adult OCD studies nevertheless provide valuable heuristic models of functioning that need to be systematically assessed in children. Moreover, combining neuro-psychological assessment with neuroimaging methods is a particularly powerful approach that promises to delineate the pathobiology of these disorders more precisely and to determine the degree of overlap between child and adult onset forms of OCD.

Adolescent↗
PubMed1997

Hemodynamic and visual function effects of oral nifedipine in patients with normal-tension glaucoma.

PURPOSE: To investigate ocular hemodynamic and visual function changes in patients with normal-tension glaucoma after treatment with a calcium channel blocker (nifedipine). METHODS: In 21 patients with normal-tension glaucoma, color Doppler imaging of the ophthalmic, central retinal, and short posterior ciliary arteries was carried out after a 4-week washout of prior drug treatment and again after 6 months of treatment with nifedipine (30 mg per day). Visual field sensitivity, spatial contrast sensitivity, and intraocular pressure were also recorded. RESULTS: Three subjects experienced intolerable side effects from the drug and were removed from the study. In two other patients, visual function was substantially reduced after 4 months of treatment; nifedipine was discontinued. In the remaining 16 subjects, mean intraocular pressure, retrobulbar hemodynamics, visual field mean sensitivity, and contrast sensitivity at 3, 12, and 18 cycles per degree (cpd), respectively, were unchanged after nifedipine treatment. Contrast sensitivity at 6 cpd, however, improved after drug treatment (P = .004). Individuals with the greatest improvements in contrast sensitivity at 6 cpd showed the largest increases in ophthalmic arterial peak systolic velocity (r = .57; P = .02) and end-diastolic velocity (r = .65; P = .001). CONCLUSION: Nifedipine fails to provide uniform visual function or retrobulbar hemodynamic responses in patients with normal-tension glaucoma. Those patients who do show improved visual function also show improved indices of retrobulbar perfusion.

Administration, Oral↗
PubMed1997

Metacercarial encystment and in vivo cultivation of Cercaria lebouri Stunkard 1932 (Digenea: Notocotylidae) to adults identified as Paramonostomum chabaudi Van Strydonck 1965.

Cercariae found occurring in naturally infected gastropod molluscs, Littorina littorea, were identified as Cercaria lebouri Stunkard 1932. They were induced to form metacercarial cysts on the surface of glass Petri dishes. Each cercaria became attached by its oral sucker and adopted a disc-like shape before discarding its tail. A transparent cyst wall was secreted over and around each organism, inside which developmental changes were observed for up to 4 weeks. Six-week-old metacercariae were fed to 1-day-old chickens which yielded adult worms 12 days later. The worms were measured, photographed and described. Initially, attempts to identify the adult worms using a key and catalogue proved ineffective. However, comparison of the adult flukes grown from C. lebouri with the definitive description of Paramonostomum chabaudi van Strydonck 1965 indicated that the two organisms are synonymous. The larval stages of P. chabaudi had not, until now, been identified.

Animals↗
PubMed1997

Altered retrobulbar vascular reactivity in early diabetic retinopathy.

AIM/BACKGROUND: In diabetic eye disease the factors leading to compromised circulation and the resulting loss of visual function are poorly understood. Although retinal circulation has been widely investigated, it accounts for only a fraction of total eye blood flow. Blood flow was investigated in the larger vessels feeding the eye in patients with early diabetic retinopathy. METHODS: Eleven patients with early diabetes with minimal or no retinopathy and 11 healthy controls were evaluated for retrobulbar blood flow velocity using colour Doppler imaging for the ophthalmic and central retinal arteries. Patients and subjects were tested while breathing room air and again under conditions of isocapnic hyperoxia. RESULTS: Hyperoxia induced a significant change in the central retinal artery end diastolic velocity (EDV) (p = 0.008) and resistance index (RI) (p = 0.032) in normal subjects, but not in diabetic patients. Consequently, during hyperoxia, the diabetic patients were significantly higher for EDV (p = 0.006) and significantly lower for RI (p = 0.002) compared with normal controls. Hyperoxia caused no significant change in either group in the ophthalmic artery; nevertheless, under isocapnic hyperoxia conditions the diabetic patients had lower peak systolic velocity (p = 0.05) and lower RI (p = 0.05) than normal subjects. CONCLUSIONS: Imposition of isocapnic hyperoxia produces significant differences in the ophthalmic and central retinal artery blood flow velocities in diabetic patients with early disease when compared with normal subjects. These results demonstrate that diabetic patients with minimal or no retinopathy suffer from irregular ocular vascular function in the major vessels feeding the eye.

Adult↗
PubMed1997

Effect of regular inhaled salbutamol on airway responsiveness and airway inflammation in rhinitic non-asthmatic subjects.

BACKGROUND: Regular, inhaled beta 2 agonists may increase airway responsiveness in asthmatic subjects. The mechanism is not known but may be via an increase in airway inflammation. A study was undertaken to examine the effect of regular inhaled salbutamol on airway responsiveness to methacholine and hypertonic saline, on the maximal response plateau to methacholine, and on inflammatory cells in induced sputum in rhinitic non-asthmatic subjects. METHODS: Thirty subjects with a baseline maximal response plateau of > 15% fall in forced expiratory volume in one second (FEV1) entered a randomised, placebo controlled, parallel trial consisting of two weeks run in, four weeks of treatment, and two weeks washout. Methacholine challenges were performed at the beginning of the run in period, before treatment, after treatment, and after washout. Hypertonic saline challenges were performed before and after treatment and induced sputum samples were collected for differential cell counting. RESULTS: There was no change in airway responsiveness, maximal response plateau to methacholine, or in induced sputum eosinophils or mast cells. The maximum fall in FEV1 after hypertonic saline increased in the salbutamol group (median change 6.0%, interquartile range (IQR) 11.0) but did not change in the placebo group (median change 1.3%, IQR 5.5). CONCLUSIONS: Regular inhaled salbutamol for four weeks increases airway responsiveness to hypertonic saline but does not alter airway responsiveness to methacholine or cells in induced sputum in non-asthmatic individuals with rhinitis. The relevance of these findings to asthmatic subjects has not been established.

Administration, Inhalation↗
PubMed1997

Ritual, habit, and perfectionism: the prevalence and development of compulsive-like behavior in normal young children.

Young children engage in a significant amount of ritualistic, repetitive, and compulsive-like activity that appears to be part of their normal behavioral repertoire. Empirically, little is known about the onset, prevalence, and developmental trajectory of these phenomena. A parent-report questionnaire, the Childhood Routines Inventory (CRI), was developed to assess compulsive-like behavior in young children, and was administered to 1,492 parents with children between the ages of 8 and 72 months. The CRI has strong overall internal consistency and a distinct two-factor structure. The frequency of compulsive-like behaviors changes with age: Two-, 3-, and 4-year-olds engaged in more compulsive behavior than children younger than 1 year of age and older than 4 years of age. Results are discussed from a developmental psychopathology framework and for their implications for future research in this area.

Child↗
PubMed1996

Effect of window size on detection acuity and resolution acuity for sinusoidal gratings in central and peripheral vision.

Detection and resolution of square patches of sinusoidal gratings were measured in central and peripheral vision (30 degrees horizontal temporal visual field) for high-contrast gratings as a function of the number of cycles in the stimulus. We determined performance in a forced-choice paradigm for a fixed number of stimulus cycles by arranging for stimulus diameter to vary inversely with spatial frequency. For both psychophysical tasks and for both target locations, the psychometric function relating performance to log spatial frequency shifted to higher frequencies without changing slope significantly as the number of cycles in the stimulus was increased. Thus the entire effect could be captured by an analysis of spatial acuity, which increased with increasing number of grating cycles over the range 0.5-6 cycles but remained constant over the range 6-14 cycles. In the central field, resolution acuity and detection acuity were equal regardless of the number of cycles in the stimulus. In the peripheral field, detection acuity exceeded resolution acuity and perceptual aliasing occurred for stimuli in the range 1-14 cycles. From this result we conclude that resolution acuity is sampling limited in the periphery, provided that the stimulus contains at least one full cycle of the grating. Essential features of the results could be accounted for by Fourier analysis of the stimulus.

Fovea Centralis↗
PubMed1995

Self-perceptions of adolescents with and without mood disorder: content and structure.

This study compared the self-perceptions of three groups of adolescents: one group with conduct disorder, a second group comorbid with both mood and conduct disorder, and a third group of normal controls. Results indicated that the three groups differed on several domains of self-perception, with each group reporting perceived strengths and weaknesses. Second-order principal component analyses revealed differences across groups in the structure of their self-perceptions. Finally, regression analyses indicated that self-perceptions share variance with a mixture of internalizing and externalizing symptoms. Results are discussed from a clinical-developmental perspective.

Adolescent↗
PubMed1995

Mental and chronological age as predictors of age-appropriate leisure activity in children with mental retardation.

Effects of MA and CA on everyday leisure-time behaviors of children with mild and moderate mental retardation were examined by comparing 40 children with mental retardation to groups of 40 MA- and 40 CA-matched children without mental retardation on an adult-reported scale. Child's overall score, highest single behavior performed by the child, and highest behavior not performed because it was considered below the child's level were measured. Children with retardation performed most similarly to their MA-matches and well-below levels of CA-matches. Older children received higher scores in all groups. Late adolescents with retardation performed between MA- and CA-levels on the highest behavior considered too immature. Although MA best predicted overall functioning on leisure-time behavior of children with retardation, CA best predicted both single highest behavior performed and highest behavior considered too immature. Implications for teaching leisure-time behaviors to individuals with mental retardation were discussed.

Activities of Daily Living↗
PubMed1994

Self-complexity and its relation to development, symptomatology and self-perception during adolescence.

Self-complexity refers to the degree to which various aspects of self-concept are differentiated from each other. A new measure of self-complexity (the SCI) was administered to 182 adolescents. The SCI correlated positively with chronological age and global self-worth and was negatively related to internalizing and externalizing symptoms. Regression analyses indicated that the SCI was the best predictor of depression when holding global self-worth constant.

Adolescent↗
PubMed1994

Self-perception and adolescent psychopathology: a clinical-developmental perspective.

The relationship between self-perception and adolescent psychopathology was examined on nine domains of self-perception in a group of adolescent psychiatric inpatients and a comparison group of nonpatients. Inpatients rated themselves significantly lower in four domains, and correlations between symptom reports and domains of self-perception supported a relationship between negative self-perception and psychopathology. Further analysis suggested less differentiated self-perceptions among inpatients than among nonpatients. Implications for developmental assessments and clinical interventions are discussed.

Adolescent↗
PubMed1994

Test-retest reliability of the CSV-1000 contrast test and its relationship to glaucoma therapy.

PURPOSE: To determine the relationship between changes in contrast sensitivity, if any, after glaucoma therapy and the test-retest reliability of the CSV-1000 contrast sensitivity test. METHODS: Patients with primary open angle glaucoma (N = 16) were retrospectively evaluated to determine changes in visual function, as measured by contrast sensitivity, after beta-blocker therapy. A control group (N = 24) of normally sighted patients was tested and retested on contrast sensitivity. For the control group, the coefficients of repeatability (95% confidence interval for test-retest variability [COR]) were calculated for each spatial frequency. The CORs were compared to the changes in vision found after therapy in the patients with glaucoma. RESULTS: The group with glaucoma showed a significant improvement (P < .01) in contrast sensitivity at all spatial frequencies. The test-retest variance for normals, as measured by the COR, was smaller than the mean differences in contrast sensitivity before and after therapy at all spatial frequencies, expect 18 cyc/deg. CONCLUSIONS: Visual function in patients with glaucoma, as measured by contrast sensitivity, does improve after beta-blocker therapy. Further, the CSV-1000 is a clinically reliable tool for monitoring these changes.

Aged↗
PubMed1994

Profiles and development of adaptive behavior in children with Down syndrome.

The profiles and developmental trajectories of adaptive behavior were cross-sectionally examined in 80 children with Down syndrome ages 1 to 11.5 years using the Vineland Adaptive Behavior Scales. Profile findings indicated a significant weakness in communication relative to daily living and socialization skills. Within communication itself, expressive language was significantly weaker than receptive skills, especially when children's overall communicative levels were above 24 months. One to 6-year-old children showed significant age-related gains in adaptive functioning, but older subjects showed no relation between age and adaptive behavior. There was, however, increased variability within this older group, implying that not all children plateau in adaptive development during the middle childhood years. Implications for development in Down syndrome and intervention programs were discussed.

Activities of Daily Living↗
PubMed1993

An assessment of total and leachable contaminants in zebra mussels (Dreissena polymorpha) from Lake Erie.

Samples of zebra mussels, Dreissena polymorpha, from populations infesting two power generating stations on Lake Erie were subjected to tests assessing the potential for leaching of metals and other (inorganic and organic) contaminants from mussel waste destined for disposal in conventional landfills. These tests revealed that mussels collected from Ontario Hydro's Nanticoke Thermal Generating Station and Niagara Mohawk Power Corporation's Dunkirk Steam Station did not release hazardous materials in excess of limits set forth in Canadian and U.S. regulations, respectively. A variety of metals and inorganic materials leached from Nanticoke mussels at levels significantly lower than the registration limits for those analytes. Detectable levels of chloroform (0.080 mg/liter) and barium (3.3 mg/liter) leached from Dunkirk mussels at > 30-fold lower levels than U.S. regulatory action limits for those materials. Whole body analyses revealed a lack of detectable levels of herbicides and pesticides in either population with a variety of metals and inorganic constituents in all samples from both populations. The physiological condition of Dunkirk mussels appeared to be consistent with that of other Lake Erie populations based on percentage water and total fat content of soft tissues.

Animals↗