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Biomedical subjects

D T Wang

Publications and source records attributed to D T Wang.

At least 19 recordsLinked to original sources
PubMed2001

High-level expression and single-step purification of human tryptophanyl-tRNA synthetase.

Human trpS gene was cloned into the expression vector pET-24a(+) to yield pET-24a(+)-HTrpRS, which could direct the synthesis of a mammalian derived protein in Escherichia coli BL21-CodonPlus(DE3)-RIL. The vector allows overproduction and single-step purification of His(6)-tagged human tryptophanyl-tRNA synthetase by the facilitation of metal (Ni(2+)) chelate affinity chromatography. The expression level of human TrpRS was about 40% of total cell proteins after isopropyl beta-D-thiogalactoside induction. The overproduced human TrpRS-His(6) could be purified to homogeneity within 2 h and about 24 mg purified enzyme could be obtained from 400 ml cell culture. The His(6) tag at C terminus had little effect on the binding ability of its substrates.

Chromatography, Affinity↗
PubMed2001

Measurement of parenting self-efficacy and outcome expectancy related to discussions about sex.

The purpose of this study was to evaluate the psychometric properties of two scales--one to measure the self-efficacy of parents to discuss sexual health issues with their adolescents and the other to measure parents' outcome expectancy associated with such discussions. Understanding how parents feel about their confidence in talking with their children about important sexual health issues and the outcomes they expect as a result of such discussions can be useful in guiding both the development and refinement of educational programs to promote parent-child discussions. The responses of 491 mothers who participated in an HIV prevention intervention with their adolescents were used for the present analysis. Mothers ranged in age from 25 to 68 years with a mean of 37.9 years (SD = 6.9). Of mother participants, 33% were married, 96.7% were African American, and 89.2% had completed high school. Their adolescents ranged in age from 11 to 14 years, and 61.5% were male. Assessment of reliability for both scales showed that internal consistency reliability was acceptable for the total scales as well as three of the five subscales. With the exception of one item on the outcome expectancy scale, the inter-item correlations, the mean inter-item correlations, and the item-to-total correlations meet the standard criteria for scale development for both scales. Factor analysis was used to identify the underlying structure of the scales, and hypothesis testing was used to assess construct validity. The results of these analyses provide support for the construct validity of the scales.

Adolescent↗
PubMed2000

Gimme 5 fruit, juice, and vegetables for fun and health: outcome evaluation.

A theory-based multicomponent intervention (Gimme 5) was designed and implemented to impact fourth- and fifth-grade children's fruit, juice, and vegetable (FJV) consumption and related psychosocial variables. Gimme 5 was a randomized controlled intervention trial with school (n = 16 elementary) as unit of random assignment and analysis. Participants included the cohort of students who were in the third grade in the winter of 1994 and students who joined them in the fourth and fifth grades. The intervention included a curriculum, newsletters, videotapes, and point-of-purchase education. Evaluation included 7-day food records and psychosocial measures from students, telephone interviews with parents, and observational assessments. Favorable results were observed for consumption of FJV combined, FJV consumed at weekday lunch, eating FJV self-efficacy, social norms, asking behaviors, and knowledge. A theory-based school nutrition education program can help change children's FJV consumption and impact factors at home that predispose to FJV consumption, but changes were small, and their persistence is unknown.

Child↗
PubMed2000

Gimme 5 fruit and vegetables for fun and health: process evaluation.

Gimme 5 (Georgia) was a school-based nutrition education effectiveness trial to help fourth- and fifth-grade students eat more fruit, 100% juice, and vegetables (FJV). Process evaluation assessed fidelity of implementation, reach, and use of intervention materials and environmental mediators: teacher training, curriculum delivery, participation in family activities, attendance at evening point-of-purchase grocery store activities, and availability and accessibility of FJV at home. Approximately half of the curriculum activities were implemented in fourth and fifth grades. The lowest proportion completed were those most pertinent to behavior change. Eighty-seven percent of parents reported participating in homework activities with their fourth grader, 66% with fifth graders. Sixty-five percent of parents reported viewing a video with their child in both grades. Ten percent attended evening point-of-purchase grocery store activities. The low level of implementation and modest level of participation in family activities suggest that higher levels of behavior change may have occurred if exposure to the intervention had been higher.

Adult↗
PubMed2000

GO GIRLS!: results from a nutrition and physical activity program for low-income, overweight African American adolescent females.

This article describes the development, implementation, and results of an intervention designed for inner-city, overweight African American adolescent women. Fifty-seven participants were recruited from four public housing developments. Participants were administered physiologic, dietary, and cognitive assessments at baseline and immediately postintervention. Each session comprised three elements: (1) an educational/behavioral activity, (2) 30 to 60 minutes of physical activity, and (3) preparation and tasting of low-fat meals. In the absence of a control group, results were compared for high and low attenders, the former defined as attending at least 50% of the sessions. High attenders (n = 26) showed more favorable 6-month posttest values for most outcomes compared with low attenders (n = 31). These effects achieved statistical significance for nutrition knowledge, low-fat practices, perceived changes in low-fat practices, and social support.

Adolescent↗
PubMed1999

Evaluation of developmentally appropriate programs for adolescent tobacco cessation.

Despite introduction of numerous smoking prevention programs in schools, tobacco use has not declined among adolescents. Schools face the dilemma of what to do with students who smoke and are not ready to quit. This study evaluated two programs based on the stages of change model. The educational program, the Tobacco Education Group (TEG), was designed for adolescents not yet thinking about quitting. The cessation program, the Tobacco Awareness Program (TAP), was intended for adolescents who want to quit. Evaluation was completed on 351 students at six public high schools. Compared to a control group of adolescent smokers not assigned to programs, both intervention groups significantly decreased tobacco use. Self-reported use was validated biochemically. Self-efficacy for quitting increased in both programs. Posttest use was predicted by posttest self-efficacy, peer support, and parental support, after controlling for initial use and initial self-efficacy.

Adolescent↗
PubMed1998

Determination of diquat and paraquat in water by liquid chromatography-(electrospray ionization) mass spectrometry.

A method for the determination of the herbicides diquat and paraquat in water was developed using liquid chromatography-(electrospray ionization) mass spectrometry [LC-(ESI)MS]. The analytes were isolated on an ENVI-8 DSK solid phase extraction (SPE) disk and eluted with 5-M trifluoroacetic acid (TFA). The eluate was evaporated to dryness and the analytes were redissolved in the mobile phase (7% methanol/93% water/25-mM TFA). The extract was analyzed by liquid chromatography (C1 column) with postcolumn addition of propionic acid/methanol followed by (ESI)MS. Diquat was detected using the [M(2+)-H+] ion (M2+ = dication) at m/z 183, whereas paraquat was detected using the mono-trifluoroacetate ion pair [M2 +/- OOCCF3] at m/z 299. Quantitation was done by isotope dilution mass spectrometry using d4-diquat and d8-paraquat and the corresponding ions [M(2+)-D+] and [M2 +/- OOCCF3] at m/z 186 and m/z 307, respectively. Detection limits of 0.1 and 0.2 microgram/L, respectively (based on the dications), were adequate to meet the Ontario Drinking Water Objectives of 70 and 10 micrograms/L, respectively, and the Ontario Provincial Water Quality Objective for diquat of 0.5 microgram/L. Precision and accuracy were 14% and 6% for diquat and 12% and 3% for paraquat.

Chromatography, Liquid↗
PubMed1998

How best to measure implementation of school health curricula: a comparison of three measures.

The impact of school health education programs is often attenuated by inadequate teacher implementation. Using data from a school-based nutrition education program delivered in a sample of fifth graders, this study examines the discriminant and predictive validity of three measures of curriculum implementation: class-room observation of fidelity, and two measures of completeness, teacher self-report questionnaire and post-implementation interview. A fourth measure, obtained during teacher observations, that assessed student and teacher interaction and student receptivity to the curriculum (labeled Rapport) was also obtained. Predictive validity was determined by examining the association of implementation measures with three study outcomes; health knowledge, asking behaviors related to fruit and vegetables, and fruit and vegetable intake, assessed by 7-day diary. Of the 37 teachers observed, 21 were observed for two sessions and 16 were observed once. Implementation measures were moderately correlated, an indication of discriminant validity. Predictive validity analyses indicated that the observed fidelity, Rapport and interview measures were significantly correlated with post-test student knowledge. The association between health knowledge and observed fidelity (based on dual observation only), Rapport and interview measures remained significant after adjustment for pre-test knowledge values. None of the implementation variables were significantly associated with student fruit and vegetable intake or asking behaviors controlling for pre-test values. These results indicate that the teacher self-report questionnaire was not a valid measure of implementation completeness in this study. Post-implementation completeness interviews and dual observations of fidelity and Rapport appear to be more valid, and largely independent methods of implementation assessment.

Child↗
PubMed1998

Results of the TeachWell worksite wellness program.

OBJECTIVE: This study examined whether providing a school-based teacher wellness program enhances the impact of a health curriculum on student outcomes and improves cognitive, behavioral, and physiological outcomes among participating teachers. METHODS: Thirty-two elementary schools were randomly assigned to experimental or comparison conditions. Comparison group schools received the Gimme-5 program, a curriculum designed to increase fourth and fifty graders' consumption of fruits and vegetables. Experimental schools received Gimme-5 and the teacher wellness program, which included 54 workshops over 2 years, along with several schoolwide health activities. Physiological, behavioral, and cognitive outcomes were assessed in teachers and students. RESULTS: There was no evidence that the intervention favorably modified any student or teacher end points; nor did intervention teachers deliver the Gimme-5 program with greater fidelity than comparison teachers. CONCLUSION: Confidence in the null results is bolstered by the randomized design, baseline sample equivalence, appropriate mixed-model analyses, and lack of selective or differential attrition. Insufficient participation in the wellness program appears a likely explanation for the lack of teacher and student effects. Factors specific to the school setting and intervention may have diminished participation and, thus, intervention effects.

Adult↗
PubMed1997

Social-cognitive predictors of fruit and vegetable intake in children.

Social-cognitive theory (SCT) was used to explain the fruit and vegetable intake of 1,398 3rd graders. SCT variables assessed included self-efficacy, outcome expectations, preferences, social norms, asking skills, and knowledge. Fruit and vegetable intake was assessed with 7-day records. Bivariate correlations with fruit and vegetable intake ranged from .17 for asking skills to .29 for fruit and vegetable preferences. In analyses controlling for school-level clustering, only preferences and positive outcome expectations remained significantly associated with fruit and vegetable intake, accounting for approximately 10%-11% of the variance. Limitations in the conceptualization, scope, and measurement of the variables assessed may have contributed to the weak associations observed. Models incorporating factors other than individual-level social-cognitive variables may be required to more fully explain children's dietary behavior.

Child↗
PubMed1997

Patterns in children's fruit and vegetable consumption by meal and day of the week.

OBJECTIVE: To assess differences in children's consumption of fruit and vegetables (F&V) by day of the week and meal of the day. DESIGN: Baseline data from two school based nutrition education studies were combined for analysis. SUBJECTS/SETTING: 2984 third grade students from 48 participating elementary schools in three school districts in the metropolitan Atlanta area. MEASURES OF OUTCOME: The frequency of consumption of F&V abstracted by trained registered dietitians from prompted 7-day food records. STATISTICAL-ANALYSES PERFORMED: Mixed model analysis with meals and days as terms, controlling for the within school correlation, gender and ethnic group. RESULTS: F&V were most frequently consumed at weekday lunch, and second most frequently at dinner. Participation in school lunch accounted for a substantial proportion of F&Vs consumed at lunch. Few F&Vs were consumed at breakfast or snack. CONCLUSIONS: School lunch makes an important contribution to elementary school students' F&V consumption. Dietary change programs should target parents to increase F&V consumption at dinner, and target students for the meals over which they assert the most control: breakfast and snacks.

Adolescent↗
PubMed1990

Vacuole sign and nodule sign in early peripheral bronchogenic carcinoma. Diagnostic value and pathologic correlation.

We analyzed the radiological and pathological characteristics of 30 peripheral lung masses 1.5-3 cm in diameter. We describe the vacuole and the nodule sign. Retrospective examination of 100 conventional tomograms of peripheral pulmonary masses and comparison with the histological diagnoses allowed us to determine the usefulness of these two signs in differentiating small peripheral bronchogenic carcinomas from tuberculomas.

Adenocarcinoma↗
PubMed1989

Gastric gastrinoma.

Two patients with Zollinger-Ellison Syndrome were diagnosed and treated in PUMC Hospital, the primary tumors were found in the stomach. On sectioning of the gastrectomized specimens, 85 tumors ranging from 0.1 to 1.0 cm in diameter were disclosed in Case 1, and a large ulcero-infiltrative carcinoma-like tumor in Case 2. Both tumors had already metastasized to regional lymph nodes and/or liver. Tumor cells in both cases exhibited gastrin, NSE, GH and hCG alpha immunoreactivity immunocytochemically, and abundant neurosecretory granules of 100-250 nm in diameter under electron microscope. The clinicopathological, immunocytochemical and ultrastructural findings of tumors from these two cases met the criteria of primary malignant gastrinoma of the stomach.

Adult↗