Biomedical subjects

W O Thompson

Publications and source records attributed to W O Thompson.

At least 37 records · Page 2Linked to original sources

PubMed1994

How children remember what they have eaten.

OBJECTIVES: To determine whether students could verbalize, within 1 1/2 hours, how they remembered items eaten at the school lunch; to determine whether the categories of self-reported retrieval mechanisms were similar for two interview styles, integrated and nonintegrated; and to determine the effect of the two interview style on the accuracy of reporting items eaten by comparing reports with direct observation. DESIGN: Two styles of dietary intake interviews were compared with observed intake in a school lunch setting. SETTING: Two elementary schools in Georgia. SUBJECTS/SAMPLES: Eighty-two of 106 fourth graders from four classes volunteered; 24 (six per class) were randomly selected and assigned to an interview style. Students interviewed using a nonintegrated style verbalized how they remembered after they had reported everything eaten. Students interviewed using an integrated style verbalized how they remembered at the same time they reported eating each item. Both interview styles included free report followed by prompted report. MAIN OUTCOME MEASURES: Reported retrieval mechanisms were coded into 13 categories. Five measures of performance (specific match rate, general match rate, intrusion rate, omission rate, and overall match rate) were calculated by interview style for free report and prompted report separately. STATISTICAL ANALYSES PERFORMED: We analyzed the effect of interview style on the number of students reaching 100% accuracy after prompting and on accuracy of reporting condiments using Fisher's exact test. RESULTS: Most students could articulate how they remembered items eaten. Reported retrieval mechanism categories were comparable for both interview styles. Visual imagery, usual practice, behavior chaining, and preference were the most commonly reported retrieval mechanisms. Accuracy of free reports did not differ by interview style; however, the nonintegrated interview style produced dietary self-reports with fewer condiment omissions during free report and higher accuracy after prompting. APPLICATIONS: Determining what retrieval mechanisms children commonly use for remembering items eaten may help researchers design cues to improve the accuracy of dietary self-reports. More accurate dietary self-reports could markedly affect the many types of research that use dietary assessment.

Child↗

PubMed1994

Isothermal anneal effect on microcrack density around leucite particles in dental porcelain.

Because of the large differential in thermal expansion coefficient between leucite and the surrounding glass matrix, microcracks form around the leucite crystallites during the manufacture of dental porcelain frits. These microcracks decouple leucite from the surrounding glass matrix and affect the bulk thermal expansion of the porcelain frit (Binns, 1983). The purpose of this study was to determine if the microcrack density in a dental porcelain decreased as a result of isothermal heat treatment. Ten specimens of a commercial dental porcelain that had previously exhibited an increase in thermal expansion as a function of isothermal heat treatment were prepared and divided into two groups. The experimental group was heated to 750 degrees C and held for 16 minutes at that temperature. The control group received no anneal. The mean microcrack densities were determined by quantitative stereology to be 575 cm2/cm3 +/- 75 cm2/cm3 (mean +/- SEM) for the control group (no anneal) and 231 cm2/cm3 +/- 25 cm2/cm3 for the experimental group (16-minute anneal at 750 degrees C). The specimens annealed at 750 degrees C had a significantly lower microcrack density (p < 0.001) than those that received no anneal. A model was developed to estimate the effect of microcracking on thermal expansion of the porcelain, and a 6% increase in the coefficient of thermal expansion of the porcelain was predicted from this model as a result of this decrease in microcrack density.

Aluminum Silicates↗

PubMed1994

Development of an enzyme-linked immunosorbent assay for measurement of fire ant venom-specific IgE.

An enzyme-linked immunosorbent assay (ELISA) was developed for in vitro measurement of IgE specific for Solenopsis invicta venom. Enhanced binding microtiter plates were coated with S. invicta venom protein and incubated with sera from fire ant allergic patients and control subjects. Bound IgE was tagged with peroxidase-conjugated monoclonal anti-IgE and quantitated with the substrate/indicator system H2O2/tetramethylbenzidine. Absorbance (620 nm) represented venom-specific IgE values. The ELISA correlated well with the imported fire ant venom RAST (r = .87, P < .0001). Using skin test reactivity as the standard measure of venom-specific IgE, the venom ELISA appeared to be a sensitive in vitro assay comparable to venom RAST. ELISA is less expensive than RAST and does not require licensing or handling of radioisotopes.

Adult↗

PubMed1994

The relationship among television watching, physical activity, and body composition of young children.

PURPOSE: Television watching has been reported to be associated with obesity, resting energy expenditure, and lower daily physical activity among both children and adolescents. However, most of these studies were based on self report or data collected in laboratory settings. This study examined the relationship among observed time of television watching, observed physical activity level and body composition among 3- or 4-year-old children. METHODS: African-American (41.4%), Mexican-American (23%), and Anglo-American (35.6%) children (N = 191, males = 90) from the Texas site of the Studies of Child Activity and Nutrition program were observed from 6 to 12 hours per day up to 4 days over 1 year. Activity level each minute of the day was measured with the Children's Activity Rating Scale (interobserver reliability = .84 +/- .001). The interobserver reliability of time of television watching was .96 +/- .08. RESULTS: The median of the longest number of consecutive minutes of television watching was 15 (range = 1 to 79). The median percent of minutes of television watching of total observed minutes was 14.8% (0% to 58%) and the median percent of minutes of inside minutes was 17.9% (0% to 80.9%). There were no gender or ethnic differences in time watching television or physical activity during television watching. Physical activity during television watching was lowest during the longest bout of television watching (mean = 1.48 +/- .28) compared to outside minutes (mean = 2.38 +/- .21), inside non-television minutes (mean = 1.96 +/- .13) and inside television minutes (mean = 1.65 +/- .18). The level of physical activity during television-watching times was highest (P < .0031) during October and November and lowest during March, April, June, and July. Longest bout of television watching and percent of minutes watching television to total observed minutes were inversely associated with mean physical activity, percent of minutes of physical activity levels 3, 4, or 5, and percent of physical activity levels 4 or 5. Percent of television watching to inside minutes was negatively correlated with physical activity levels 4 or 5. Television-watching behavior was not associated with body composition. CONCLUSIONS: Television watching was weakly negatively correlated with physical activity levels, and physical activity was lower during television-watching than non-television-watching time in this sample of children. Television viewing behavior was not associated with body composition.

Black or African American↗

PubMed1993

Carotid plaque associations among hypertensive patients.

OBJECTIVE: To assess the relationship between cardiovascular risk factors and carotid plaque. DESIGN: Hypertensive patients were screened for randomization into the Multicenter Isradipine Diuretic Atherosclerosis Study, a trial intended to determine if blood pressure control by isradipine as compared with hydrochlorothiazide will blunt the progression of carotid plaque (intima plus media thickness, 1.3 to 3.5 mm) in patients with serum cholesterol levels of less than 6.85 mmol/L (265 mg/dL) without insulin-dependent diabetes mellitus or estrogen therapy. Demographics of those who underwent B-mode ultrasound evaluations at common, bifurcation, and internal carotid artery sites to detect plaque were assessed from a southern and a northern site. SETTING: Participants were from ambulatory outpatient clinics associated with medical schools. PATIENTS: The initial screening included 1823 hypertensive volunteer patients who were between 40 and 83 years of age who had a diastolic pressure of 90 to 114 mm Hg (or < 90 mm Hg with treatment). OUTCOME MEASURES: Complete data were collected on the variables of age, cholesterol, cigarette smoking, race, gender, and the presence of carotid plaque in 1126 patients. RESULTS: All variables were significantly associated with carotid plaque (intima plus media thickness, > or = 1.3 mm). The adjusted percentage with plaque was 66.4% +/- 3.4% for blacks and 70.1% +/- 2.3% for whites at the southern site and 42.7% +/- 4.5% for blacks and 61.3% +/- 3.2% for whites at the northern site. The rate of plaque was 75.8% among cigarette smokers, despite a mildly elevated cholesterol level. CONCLUSIONS: Although these 1126 cases do not constitute a random sample of patients, these data suggest that there may be regional differences in racial tendencies toward plaque among blacks.

Aged↗

PubMed1993

Lymphocytic colitis. A definable clinical and histological diagnosis.

We reviewed colorectal biopsies and clinical records from 36 patients with chronic watery diarrhea who had been diagnosed as having microscopic colitis and compared their histologic features with the more detailed and precise criteria for lymphocytic colitis. Published pathologic criteria for lymphocytic colitis were applied to the biopsies and compared. Focal or diffuse nature of the lymphoid infiltrate were noted separately. The focal lymphoid infiltrate was related to lymphoid aggregates in the lamina propria of the mucosa. Eighteen cases had focal lymphoid cell infiltration, and 16 of them had associated diverticula, polyps, or both. Eighteen cases had diffuse lymphoid cell infiltration, and six of them had diverticula or polyps. Results indicate that focal cellular infiltration strongly predicts associated diverticula or polyps. The group with no diverticula or polyps most closely conformed to histologic criteria for lymphocytic colitis (Kruskal-Wallis P < 0.02). We conclude that lymphocytic colitis comprises a well-defined group of cases within the large and less-defined group of microscopic colitis.

Adult↗

PubMed1993

Association among serum lipid and lipoprotein concentrations and physical activity, physical fitness, and body composition in young children.

OBJECTIVE: To examine the relationships among indicators of physical activity, physical fitness, and body composition with serum lipid and lipoprotein levels in young children. DESIGN: Cross-sectional and 1-year prospective cohort. SETTING: Studies of Child Activity and Nutrition (SCAN) program, Galveston, Tex. SUBJECTS: One hundred twenty-three 4- or 5-year-old black, Hispanic (of Mexican origin), and white children. MEASUREMENTS: Body composition, resting heart rate, and cardiovascular fitness variables and serum lipid and lipoprotein levels were measured at age 3 or 4 years (study year 1) and at age 4 or 5 years (study year 2), and day-long heart rate was measured and the Children's Activity Rating Scale was administered between study years 1 and 2. RESULTS: Year-1 waist/hip ratios were inversely correlated with total serum cholesterol (TSC) and low-density lipoprotein (LDL) levels. Mean activity level was inversely correlated with waist/hip ratios. On the basis of multiple regression analysis, the sum of seven skin-fold measurements, height, and gender explained 15.4% of the variation in triglyceride levels. The sum of seven skin-fold measurements was inversely correlated with the high-density lipoprotein (HDL) level. Resting heart rate, waist/hip ratio, and the slope of the exercise heart rate during fitness testing explained 19.5% of the variation in the concentration of an HDL subclass, HDL2. These children's levels of physical activity were associated with higher fitness levels. Year-1 waist/hip ratios and year-2 sum of seven skin-fold measurements were positively correlated with the LDL/HDL and TSC/HDL ratios. CONCLUSION: Higher levels of cardiovascular fitness and lower levels of fatness were associated with more favorable serum lipid and lipoprotein levels in these young children. Physical activity appeared to have an indirect association with serum lipid and lipoprotein values through its relationship with higher fitness levels and lower levels of fatness.

Activities of Daily Living↗

PubMed1993

Observations on physical activity in physical locations: age, gender, ethnicity, and month effects.

The level of physical activity of 3- and 4-year-old children was assessed in alternative physical locations by month and time of day and by age, gender, and ethnicity. Physical activity was assessed by observation with the Children's Activity Rating Scale (CARS) for up to 12 hours from 7:00 am to 7:00 pm. A sample of 191 three- and four-year-old children was observed for up to four times in the course of a year. The sample was tri-ethnic. Boys were significantly more active than girls. Activity was consistently higher outside than inside. There were significant differences in the amount of time children in this age group spent inside versus outside by time of year; the activity levels of boys and girls differed by time of year, particularly when outside. A model including gender, month, and location terms accounted for 75% of the variance in physical activity. These data further documented gender differences in physical activity among very young children using measures not subject to self-report biases but did not explain or clarify the gender differences. The substantial differences by physical location and time of year deserve future attention, but more refined methods will be needed to balance data by location and important seasonal times. An inference from these results is that activity levels among young children may be increased by encouraging them to spend more time outdoors.

Activity Cycles↗

PubMed1993

Immunocytochemical study of insulin-like growth factor I and insulin-like growth factor I receptor in human endometrium during the normal menstrual cycle.

Our aims were to detect, using immunocytochemistry, IGFI and IGFI R in the human endometrium and to assess semiquantitatively their levels in the phases of the normal menstrual cycle. Twelve normal proliferative and 10 normal secretory endometrial samples were studied. Each specimen was subjected to an immunocytochemical peroxidase antiperoxidase protocol. The antibodies used to detect IGFI and IGFI R were, respectively, 3D1/2/1 and alpha 1R3. Analysis of variance (ANOVA) was performed to evaluate mean IGFI and IGFI R levels in the glandular epithelium and stroma of each sample while correcting for intra- and interobserver variation. These experiments show the presence of IGFI and IGFI R in human endometrium. There are significant variations in the IGFI and IGFI R levels from patient to patient within each cycle phase, and between glands and stroma within each sample. These findings highlight the importance of the use of in situ studies to clarify endometrial IGFI and IGFI R physiology.

Endometrium↗

PubMed1993

Evaluation of the Children's Activity Rating Scale (CARS) in young children.

We describe the daily activity patterns and the between-day and -year reliabilities of the Children's Activity Rating Scale (CARS) measured in 180 Anglo-, African-, and Mexican-American children aged 3 or 4 yr. Reliabilities were assessed at up to 11 measurement periods over 3 yr. CARS scores were measured by two trained observers (alternating 2-h shifts) up to 12 working hours. There were no significant ethnic or day of week differences in the activity levels. Males had higher mean activity levels than females and higher activity was performed in the summer and fall than the spring or winter. The all-measurements reliability for a mean of 5.34 d of observation over the 3 yr of measurement was 0.57. The reliability across all days and years of measurement was 0.73. The highest level of reliability (0.75) was found for the percent of minutes spent at CARS levels 3, 4, or 5 followed by an intraclass correlation of 0.74 for percent of minutes spent at CARS levels 4 or 5. These data support the utility of using the CARS as a measure of physical activity in younger children from different ethnic groups.

Activities of Daily Living↗

PubMed1993

The meniscus in the cruciate-deficient knee.

Evidence clearly implicates meniscectomy as a primary factor in the premature development of OA of the knee joint. Although data demonstrate the ability of the menisci to transmit load, they do not contribute to the primary stability of the knee. In the absence of the ACL, the menisci have been shown to enhance the knee's stability in the AP, varus-valgus, and internal-external directions in vitro. Clinically, the argument that the menisci are important secondary stabilizers is less clear. The restraining capacity of the menisci to AP translation is much smaller than the forces the knee is subjected to in vivo during activities of daily living. Additionally, these forces can increase as much as threefold during strenuous athletics. It becomes apparent, on review of the literature, that the menisci clearly are not designed to participate as a significant restraining mechanism for the ACL-deficient knee. The incidence of acute meniscal tear is 52% and increases to 83% in the long run. It is important to realize that although the menisci contribute in part to the stability of the ACL-deficient knee, such a role places them at risk for injury. When meniscal lesions are noted in the ACL-deficient knee, it is important to bear in mind the patient's goals, including his or her willingness to have an ACL reconstructive procedure and desire to return to sports. Also, the tear's configuration and location dictate its the ability to heal. One final area of interest relates to the fate of an ACL reconstruction in the meniscus-deficient knee. Although the meniscus is not a participant in primary stability, the subtle alteration in knee joint kinematics may create unfavorable conditions for the ACL graft. It is possible that the menisci may provide some protection to an ACL-reconstructed knee by restoring normal knee joint kinematics. Such a situation may explain why some ACL reconstructions in the meniscectomized knee fail over time. Prosthetic meniscal substitution or allograft meniscal transplantation are techniques on the horizon and may prove useful in the future when the remaining meniscus cannot be repaired.

Animals↗

PubMed1993

Gastrointestinal effects of sugarbeet fiber and wheat bran in healthy men.

Gastrointestinal effects of feeding 20 g total dietary fiber as wheat bran (WB) and sugarbeet fiber (SBF) were compared in 17 healthy men in a randomized cross-over design. The fibers were milled to similar particle sizes and consumed as supplements to the subjects' self-selected diets (SS). Transit times were similar among the diets. Fecal wet and dry weights were greater on the fiber diets compared to the SS diet (P < 0.05); wet weights were similar with WB and SBF; dry weights were greater with WB than SBF (P < 0.001); and moisture content was lower with WB than SBF (P < 0.01). Fecal pH was lower with WB than SBF (P < 0.025). WB and SBF provided similar fecal bulking effect; however, the contribution of fecal dry matter and fecal water content to increased bulk differed between fibers.

Adult↗

PubMed1993

Reliability and variability of indicators of heart-rate monitoring in children.

We describe the daily heart-rate patterns and the between-day and within-day reliabilities of several heart rate indicators measured in 131 Anglo-, African-, and Mexican-American children aged 5-7 yr. Heart rates were measured over 12 waking hours with a Quantum XL Telemetry heart rate monitor. The percent of heart rates 25% above resting heart rate, an index of physical activity heart rate (PAHR-25 index), was found to have the highest within-day (0.92) and between-day (0.81) reliabilities. The Spearman-Brown prophecy formula indicated that only 9.3 h of observation would be needed to maintain a within-day reliability of 0.90. The percentage of heart rates 50% above resting heart rate (PAHR-50) was found to have slightly lower within-day (0.88) and between-day (0.56) reliability. Principal components analysis revealed that the PAHR-25 and PAHR-50 indicies only had one component throughout the day. The PAHR-25 and PAHR-50 indicies were weakly correlated with age, suggesting that they may be good indicators of relative PAHR. Male children had higher (P < or = 0.025) PAHR-25 index scores than females. There were no gender or ethnic differences in the PAHR-50 index.

Black or African American↗

PubMed1993

Cerebral lateralization and histamine skin test asymmetries in humans.

Although asymmetries exist in both cerebral and somatic systems, their relationship is not well understood. One hypothesis suggests that some processes determining cerebral hemispheric dominance also affect immune systems. We employed histamine, a final common mediator for the immediate hypersensitivity immune response, to examine the relationship of skin response to cerebral lateralization (ie, left versus right brain dominance). Histamine skin wheal responses on the left and right forearms were measured using computerized planimetry in 176 consecutive patients undergoing allergy skin testing. Cerebral lateralization was determined by personal and family handedness via questionnaires. Subjects were classified as right handed (RH) with only RH relatives, RH with non-RH relatives, or non-RH (ie, left-handed or ambidextrous). Left/right arm asymmetries in wheal area were demonstrated and were related to cerebral dominance, but could not be explained by simple arm use. Right-handed subjects with only RH relatives had greater wheal size on the right arm, RH subjects with non-RH relatives had no significant left/right difference in wheal size, and non-RH subjects had greater wheal size on the left arm. Further, gender differences in these asymmetries appeared to be present for subjects with mixed cerebral dominance. The results suggest an association between process affecting cerebral and somatic asymmetries, and offer new insight into brain/body interactions.

Adolescent↗

PubMed1992

The effect of glaze on porcelain strength.

The self-glazing technique provides an esthetic and hygienic surface for crowns and fixed partial dentures that use porcelain veneers. A study of the biaxial flexure strengths of polished vs. glazed specimens is needed to verify that current laboratory methods are appropriate for planned fatigue studies. Four groups of 50 porcelain disk specimens each were subjected to the following polishing and firing procedures: group one was fired, glazed-no hold, and polished; group two was fired, polished, and glazed-no hold; group three was fired, polished and glazed-1 min. hold; group four was fired, polished, and not glazed. The piston-on-three-ball method was used for testing biaxial flexure strengths. Significantly lower differences in biaxial flexure strengths were noted when group two values were compared with values from groups one, three and four. The results show that the Weibull distribution is an appropriate model for our studies. Differences in glaze thickness among the groups were noted in SEM examination; however, bulk (interior) microcrack density differences were absent. The specimens that were fired, polished to a 1 micron surface finish, and not glazed (group four) were significantly higher in flexure strength than groups one and three at the p less than 0.001 level. The hypothesis that glazing of porcelain surfaces improves the biaxial flexure strength of test specimens was rejected.

Dental Casting Technique↗

PubMed1992

Calcium and phosphorus content of roots exposed to the oral environment.

This study analyzed the calcium and phosphorus content of extracted tooth roots exposed to the in vivo oral environment. 20 teeth were obtained from 16 patients and divided into two groups of 10 teeth each. In group 1, the teeth had gingival probing depths of 5 mm or more, and teeth of group 2 had gingival recessions of 3 mm or more. Prior to extraction, the gingival margin location was recorded by placing a groove on the tooth surface. After extraction, the teeth were sectioned coronal-apically, air dried and coated with carbon. Energy dispersive X-ray spectra, excited in a scanning electron microscope, were analyzed to measure relative calcium and phosphorus contents and for calculation of their ratios. X-rays were collected from two positions on the sectioned root. Experimental positions were selected within the exposed portion of the roots of groups 1 and 2, and unexposed positions were selected from that portion of the same root with attached periodontal membrane. At each position, calcium and phosphorus content was measured at 4 depths into the root surface: in cementum, in dentin three-quarters of the distance to the pulp chamber, and at 2 locations in between on either side of the cemento-dentinal junction. Analysis of data demonstrated large variations in calcium and phosphorus content from surface to surface of individual teeth and from tooth to tooth in a subject. No statistically significant differences were found between experimental and unexposed locations. Calcium and phosphorus contents were greater in roots exposed to pockets when compared to roots exposed by recession at both experimental and unexposed locations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

In vitro effects of interleukin-2 and gamma globulin on immune dysfunction in a patient with severe mucocutaneous herpes simplex virus infection.

A previously healthy woman developed severe, recurrent mucocutaneous herpes simplex virus (HSV) infection at 21 years of age. Immunologic assessment over the past 2 years has revealed persistent T-cell and natural killer cell dysfunction despite normal numbers of these cells as measured by flow cytometry. We studied the effect of recombinant interleukin 2 (rIL-2) and gamma globulin on the patient's mononuclear cells in 18-hour 51Cr release assays using HSV-infected and uninfected target cells. Both gamma globulin and rIL-2 significantly enhanced target cell lysis of HSV-infected target cells (P less than .001), but did not increase lysis of uninfected target cells. Addition of the patient's serum had no effect on HSV-infected target cell lysis despite a high HSV IgG titer, indicating a possible specific abnormality in production of antibody-dependent cellular cytotoxicity antibody.

Adult↗

PubMed1992

Reliability and variability of heart rate monitoring in 3-, 4-, or 5-yr-old children.

We describe the daily heart rate patterns and the between day and within day reliabilities of several heart rate variables measured in 159 Anglo-, African-, and Mexican-American children aged 3-5 yr. Heart rates were measured over 12 waking hours with a Quantum XL Telemetry heart rate monitor. There were no significant ethnic, gender, day of week, or season of the year differences in either mean resting heart rate, mean daily heart rate, mean longest duration of the heart rate sustained above 120 bpm for the day, nor percent of minutes of daily heart rate above 120 bpm. The reliabilities for these variables for 2 d of observation separated by 3-6 months ranged from 0.65 to 0.66. At this level of reliability, just over 4 d of recording are necessary to achieve a reliability of 0.80. All within-day across-hour reliabilities were greater than 0.80. However, for mean hourly heart rate and the longest duration of heart rate sustained above 120 bpm each hour, a principal components analysis revealed three distinct time components during the day. This suggests that monitoring heart rate during limited portions of the day will provide a biased estimate of overall heart rate. For the morning component, there were significant ethnic and gender differences in the children's heart rates and younger children had longer durations of heart rate sustained above 120 bpm than older children. Although daily heart rate monitoring is not a perfect indicator of children's physical activity, these data suggest that it may be a reliable measure among younger children from different ethnic and gender groups.

Black People↗