Detection of human blood in the bat tick Carios (Ornithodoros) kelleyi (Acari: Argasidae) in Iowa.

The argasid tick Carios (Ornithodoros) kelleyi Cooley & Kohls is a common ectoparasite of bats and has been found in massive numbers in homes with associated bat colonies in eastern Iowa. This tick feeds nearly exclusively on bats in nature. Several inhabitants of infested homes complained of "bug bites" at night while asleep that may have resulted in erythematous, edematous, urticaric skin lesions and constitutional signs and symptoms. We provide laboratory evidence that a single, engorged C. kelleyi nymph contained host blood from a human female. The clinical implications of our findings are intriguing but unclear.

Effects of occlusal load on cervical lesions.

Toothbrush abrasion has been considered to cause cervical lesions. However, some investigators have proposed that occlusal loading factors direct tensile stresses at the cervical area, resulting in wedge-shaped abfraction defects. The purpose of this study is to investigate the role of axial and non-axial load on the development of cervical lesions. Matched paired premolars, extracted for orthodontic purposes, were used in a custom-fabricated toothbrushing apparatus. A periodontal sulcus width of 0b1 mm with 1 mm gingival recession was simulated with denture base resin. In phase 1, eight matched premolar pairs were subjected to 80 h (1b4 million strokes) of brushing and 300 g of toothbrush force. Toothpaste slurry was applied continuously through the toothbrush. One specimen in each pair was subjected to 250 h and 45 kg of continuous axial load, while the other unloaded tooth served as a negative control. In phase 2, 10 matched premolar pairs were subjected to the same conditions; however, the experimental teeth were subjected to 250 h and 45 kg of intermittent non-axial load, directed at a 45 degrees angle to the buccal cusp. Rubber impressions were made of the cervical lesions, then trimmed, weighed, and compared to determine the amount of tooth material lost. When teeth were loaded axially, there was significantly less tooth material loss (P < 0b02); however, when teeth were loaded non-axially, there was no significant difference (P =0b80) when compared with controls. Optical and scanning electron microscopy did not reveal any significant differences in the morphology between pairs. Our data suggest that the application of occlusal load may not necessarily play a significant role in the progression of cervical tooth wear commonly referred to as abfraction.

Asthma self-management: the perspective of children.

This qualitative study explored the knowledge, perceptions, and autonomy of 7- and 12-year-old children relative to the management of their asthma. A total of 32 children with moderate to severe asthma were interviewed using an open-ended drawing interview and a semi-structured interview. The triangulation of results from these two methods revealed developmental differences. Younger children identified medicines by shape, color, or lay terms, relied on adults to manage their asthma, and did not recognize warning symptoms of an attack. Older children mastered biomedical terminology and used medicines independently, although they sometimes asked for the assistance of an adult. All children perceived benefits and non-monetary costs of asthma medicines. However, they lacked understanding of the categories and role of asthma medicines. This study suggests that long-term control and quick-relief metered dose inhalers should be identifiable by consistent color-coding, and that professionals should tailor asthma education and information to children's stages of cognitive development.

A comparison of the wear resistance and hardness of indirect composite resins.

STATEMENT OF PROBLEM: Various new, second-generation indirect composites have been developed with claimed advantages over existing tooth-colored restorative materials. To date, little independent research has been published on these materials, and the properties specified in the advertising materials are largely derived from in-house or contracted testing. PURPOSE: Four second-generation indirect composites (Artglass, belleGlass, Sculpture, and Targis) were tested for wear resistance and hardness against 2 control materials with well-documented clinical application. Human enamel was also tested for comparison. MATERIAL AND METHODS: Twelve specimens of each material were fabricated according to the manufacturers' directions and subjected to accelerated wear in a 3-body abrasion, toothbrushing apparatus. Vickers hardness was measured for each of the tested materials, and energy dispersive x-ray (EDX) spectroscopy was performed to determine the elemental composition of the composite fillers. The statistical tests used for wear and hardness were the Kruskal-Wallis 1-way ANOVA test with Mann-Whitney tests and 1-way ANOVA with multiple comparisons (Tukey HSD). The Pearson correlation coefficient was used to determine the existence of a relationship between the hardness of the materials and the degree to which they had worn. The level of statistical significance chosen was alpha=.05. RESULTS: The control material Concept was superior to the other composites in wear resistance and hardness and had the lowest surface roughness. Significant relationships were observed between depth of wear and hardness and between depth of wear and average surface roughness. Enamel specimens were harder and more wear resistant than any of the composites. EDX spectroscopy revealed that the elemental composition of the fillers of the 4 new composites was almost identical, as was the composition of the 2 control composites. CONCLUSION: The differences in wear, hardness, and average surface roughness may have been due to differences in the chemistry or method of polymerization of the composites. Further research in this area should be encouraged. It was also apparent that the filler present in the tested composites did not exactly fit the manufacturers' descriptions.

Ten guiding principles for teaching children and adolescents about medicines. US Pharmacopeia.

In 1996, an open conference sponsored by the US Pharmacopeia (USP) and attended by more than 100 health care professionals established the need and rationale for teaching children and adolescents about medicines. After the conference, a public, iterative, consensus-development process including participation by 35 health-professional organizations was undertaken. This process resulted in a USP position statement, "Ten Guiding Principles for Teaching Children and Adolescents About Medicines," which supports the right of children and adolescents to receive developmentally appropriate information and direct communications about medicines that are consistent with their health status, capabilities, and culture. The position statement is intended to stimulate activities that will help children become active participants in the process of appropriate use of medicines and prepare them for the day they begin to use medicines independently.

Perception of friends' use of alcohol, cigarettes, and marijuana among urban schoolchildren: a longitudinal analysis.

Relations between adolescents' substance use and perceptions of their friends' substance use were examined cross-sectionally and longitudinally in a predominantly African-American school district. Fourth- and fifth-grade students were surveyed and tracked for 4 consecutive years. Cross-sectional samples included 3,073, 5,955, 7,701, and 6,616 students in years 1 to 4, respectively; the longitudinal sample included 1,802 students surveyed in every year. Self-reported substance use of friends and classmates also was assessed. Perceived friends' substance use had a stronger association with prior substance use than friends' self-reported substance use in every year. Perceived family use and classmates' self-reported use also made independent contributions to regression models. Longitudinal structural equation analyses indicated that perceived friends' use is more likely to be a product of an adolescent's previous substance use than a precursor of subsequent substance use. The findings contradict prevailing theories on the influence of peers on substance use.

Early adolescents' substance use and life stress: concurrent and prospective relationships.

Life stress during early adolescence has been linked to substance use. Few studies have investigated whether the amount of control the child has over stress moderates this relationship even though the role of personal control is of increasing theoretical importance. Relationships between controllable and uncontrollable life stress and substance use were investigated in 303 urban, African-American fourth and fifth graders (152 males, 151 females). Controllable life stress contributed to six regression equations predicting children's substance use both cross-sectionally and longitudinally, even when selected demographic and personal variables were controlled. Evidence supporting a similar role for uncontrollable life stress was not found.

Contradictory subject response in longitudinal research.

OBJECTIVE: This study investigated the prevalence of logical and estimation errors in a 4-year longitudinal survey of substance abuse for elementary and junior high school students. Logical errors occur when a subject reports having used a substance on one measurement occasion, but reports never having used the substance on a second measurement occasion. Estimation errors occur when a subject reports a lifetime frequency of use on a later survey that is less than the lifetime frequency of use reported for an earlier survey. METHOD: Substance abuse surveys were completed every year for four years by predominantly black District of Columbia students, beginning when the students were in 4th/5th grade, and ending when they were in 7th/8th grade. (Ns ranged from 5,671 to 6,421). Errors for alcohol, cigarette and marijuana use were calculated for every pair of years. Background characteristics such as demographic and academic performance variables were also assessed for each of the four years. RESULTS: Logical errors decreased for all substances as student got older, whereas estimation errors remained stable. Marijuana had the highest frequency of logical errors in every pair of years except one, and had the lowest frequency of estimation errors. Students who made errors in Years 1-2 were 1.64 times more likely to make errors again in Years 3-4. For some of the years, students who made any kind of error had lower school grades, were judged untrustworthy by their peers and were more likely to be males. CONCLUSIONS: The alarming prevalence of errors should be considered when conducting longitudinal substance abuse research. Several methods of dealing with these errors are reviewed. In most cases, the best a researcher can do is assess the error rates and report them.

Healthful behaviors: do they protect African-American, urban preadolescents from abusable substance use?

PURPOSE: Relationships between positive health behaviors and abusable substance use in preadolescent, urban, African-American schoolchildren were investigated. DESIGN: Personal interviews and classroom surveys were used to assess health behavior and abusable substance use cross-sectionally. SETTING: All respondents resided in the District of Columbia and attended the public school system. SUBJECTS: The sample consisted of 303 urban, African-American fourth and fifth graders (151 boys, 152 girls). MEASURES: Classroom surveys assessed drinking, drinking without parental knowledge, smoking, use of other abusable substances, friends' use, self-esteem, and academic performance. Personal interviews assessed children's diet, exercise, overall health behavior, and socioeconomic status. RESULTS: Logistic regressions showed that children who engaged in more health behaviors (exercise and proper nutrition) were one-third less likely to have smoked (OR=0.66) or to have drunk alcohol (OR=0.63) than those who engaged in fewer healthful activities. However, when gender, socioeconomic status, self-esteem, academic performance, personal use, and friends' use of other abusable substances were controlled, relationships were no longer statistically significant. CONCLUSIONS: These findings suggest that although positive health behaviors appear to be inversely related to abusable substance use in urban, African-American preadolescents, the relationship may be spurious.

Alcohol, cigarette, and marijuana use among fourth-grade urban schoolchildren in 1988/89 and 1990/91.

A public-school-based epidemiological survey of fourth-grade students in Washington, DC, was performed in 1988/89 (n = 4675) and 1990/91 (n = 4678). Comparisons of data for the two periods revealed that the lifetime prevalence of self-reported alcohol use, alcohol use without parental knowledge, and smoking more than a puff of cigarettes declined; marijuana use and cigarette experimentation did not. Seven variables were associated with use. Declines were observed in perceived peer pressure to use; seeing a family member/friend selling drugs; and being offered alcohol, cigarettes, or marijuana by peers. No declines were observed in family use, perceived friends' use, being bothered a lot if best friends use, or seeing someone else selling drugs.

Elementary schoolchildren's use of alcohol, cigarettes and marijuana and classmates' attribution of socialization.

In each of 2 years beginning in fourth and fifth grades, urban elementary public schoolchildren completed surveys about abusable substance use and health promoting behaviors and completed an instrument that permitted each child to have a socialization score attributed by classmates. A factor weighted 12-item scale was developed from 15 items in three domains (personal, interpersonal and school). The scale was positively correlated over the 2 years and positively correlated with a healthful activities scale in both years. Conditional multiple logistic regression, matching on school classroom, indicated that socialization was negatively associated with use of alcohol without parental permission and cigarettes in both years (grades 4-5, grades 5-6) and with use of marijuana in year 1. Socialization measured in year 1 was negatively associated with cigarette use in year 2 and with onset of use from year 1 to year 2. Shyness, a non-socialization scale item, was negatively associated with use of cigarettes in both years and with use of alcohol without permission and use of marijuana in year 2. Being 'good at sports' was an attribute positively associated with alcohol use without permission and cigarette use in year 2. Results suggest that elementary schoolchildren can ascribe social characteristics to their classmates that are associated with and predict health related behaviors.

Perceived vs. actual friends' use of alcohol, cigarettes, marijuana, and cocaine: Which has the most influence?

Determinants of the use of alcohol, alcohol without parental knowledge, cigarettes, marijuana, and crack were assessed in predominantly black, urban, fourth- and fifth-grade students. Each subject identified three best friends. Logistic and least-square regression analyses indicated that children's perceptions of friends' use, perceptions of family use, and actual use of classmates were better predictors of substance use than friends' actual use. The pattern of predictors suggested that peer behaviors and attitudes are more influential for children's socially censured behaviors such as using alcohol without parental permission than for more socially approved behaviors such as using alcohol with parental permission. The importance of perceived friends' use vs. friends' actual use supports Behavioral Intention Theory and Cognitive Developmental Theory, while the importance of classroom use supports Social Learning Theory or may reflect social and environmental conditions including neighborhood availability of drugs and neighborhood values regarding substance use.

Relationships among black families' cardiovascular disease risk factors.

BACKGROUND: As participants in the District of Columbia Studies of Children's Activity and Nutrition (D.C. SCAN), 262 black mothers and two of each mother's children (3-4 and 8-10 years of age) were measured in their homes for selected cardiovascular disease risk factors: serum total cholesterol, systolic and diastolic blood pressures, height and weight for body mass index, fitness (sum of pulses), activity, and triceps and subscapular skinfolds. RESULTS: For each measure, mothers in the highest quartile were more likely to have children who were also in the highest quartile, and mothers in the lowest quartile were more likely to have children who were in the lowest quartile. For the physiological measures, (with the exception of systolic blood pressure), correlations tended to be stronger between the siblings than between the younger child and the mother, and older siblings' physiological measures contributed to the prediction of younger siblings' physiological measures after controlling for mothers' physiological measures. Relationships between family cardiovascular disease risk factor history and children's serum total cholesterol, and systolic and diastolic blood pressure levels tended to be gender related; i.e., family cardiovascular disease risk factors on the mother's side were more likely to be related to levels among the female but not the male children and vice versa. When personal characteristics were controlled for, the family's cardiovascular disease history was related more strongly to the younger than to the older sibling's systolic and diastolic blood pressure levels. CONCLUSIONS: Results tend to substantiate the importance of screening and counseling other family members, especially a child of the same gender as the parent with a cardiovascular disease or an elevated risk factor level.

A process evaluation of the District of Columbia "Know Your Body" project.

A process evaluation was conducted of the effectiveness of the "Know Your Body" curriculum in reducing coronary heart disease risk factors among black elementary and junior high school students. The evaluation, part of a five-year longitudinal study, linked effectiveness of teachers' implementation with student outcomes and identified program weaknesses during implementation. Teachers with higher effectiveness scores had significantly more favorable student outcomes in systolic blood pressure, diastolic blood pressure, HDL cholesterol, HDL/cholesterol ratio, serum thiocyanate, and fitness. Of 82 teachers, 38 (46%) had scores reflecting effective teaching. Lack of time and commitment and inadequate use of the behavioral teaching approach demanded by the curriculum contributed most to implementation failure. Teachers as insufficient role models emerged as an important factor. Future research needs appropriate reinforcement of teacher participation and measurement of the environmental factors and personal teacher characteristics that may affect program implementation. School health education programs need an intensive training component that will enable teachers to adopt behavioral teaching approaches, promote teacher's examination and change of their personal risk factors, and stress the classroom dynamic of teachers as role models.

Towards rational medicine use: is there a role for children?

Irrational, wasteful, and even dangerous medicine use is a serious problem in developing countries. It is important to work to solve it through the provision of safe, efficacious and affordable drugs, through strengthening the drug regulatory systems and through the education of health care providers. However, it is important as well that the population learns to use medicines wisely. Educating children in developing countries about appropriate use of medicines is a strategy that has the potential to improve medicine use throughout the communities where the children live and for future generations. Currently, very few children's health education curricula include anything on appropriate medicine use, and what exists has not been based on what children know, or on their behavior or expectations relative to medicines in the context of their cultures. Support is sought for the inclusion of rational medicine use in comprehensive school health curricula and researchers are encouraged to develop and evaluate culturally sensitive, age appropriate, and acceptable medicine use education programs.

A Children's Health Belief Model.

The classic Health Belief Model (HBM) was adapted to explain children's expected medicine use for five common health problems. To evaluate this Children's Health Belief Model (CHBM), 270 urban preadolescents, stratified by socioeconomic status, grade level, and sex, and their primary caretakers (93% mothers) were individually interviewed. Analyses were performed in two steps. First, regression analysis evaluated the influence of the child's primary caretaker on the child's expected medicine use. Individual differences in children's motivations, perceived benefits and threats, and expectations to take medicines were partially explained by caretakers' perceptions of these children. Second, path analysis evaluated hypothesized causal relationships in the CHBM, accounting for 63% of the adjusted variance in children's expected medicine use. Two readiness factors, perceived severity of illness and perceived benefit of taking medicines, had the highest path coefficients, with illness concern and perceived vulnerability to illness accounting for a smaller, but significant, portion of the variance. Cognitive/Affective variables, notably children's health locus of control, contributed to indirect paths between demographic and readiness factors. The CHBM appears to be a promising model for studying the development of children's health beliefs and expectations.

Obesity, self-esteem, and health locus of control in black youths during transition to adolescence.

Abstract A three-year longitudinal study of 1,003 urban black children, ages nine through 12, explored the relationship between obesity, health locus of control, and self-esteem. Subjects were classified as obese or not-obese at two times, approximately two years apart. From Time 1 to Time 2, subjects were categorized as remaining the same, or either changing from obese to non-obese or non-obese to obese. Measures included the Children's Health Locus of Control scale (CHLC), the Rosenberg Self-Esteem scale (SE), and ponderosity (weight relative to height). SE and CHLC improved across the entire sample. Multiple regression analyses indicated that baseline self-esteem was associated with decreased ponderosity only for subjects who changed from obese to non-obese. Group differences imply that building self-esteem and acknowledging individual differences may facilitate treatment of adolescent obesity. Continued research is recommended.

Stability in a measure of children's health locus of control.

Increased interest in children's health locus of control has precipitated continued examination of the psychometric properties of scales measuring this concept. The Children's Health Locus of Control scale (CHLC) was administered to more than 1,000 urban black students in each of four years across three grade levels: Year 1 - grades four-six to Year 4 - grades seven-nine. Factor analyses revealed five factors forming scales with acceptable reliability at each year. Students' beliefs that they have control over their own health increased as a function of age. Beliefs in self-control had low, negative correlations with measures of external control. Stability of CHLC and the relatively simple procedure (16 dichotomous items) suggest that, despite problems with wording of some items, CHLC is an appropriate and efficient measure for comparing cross-sectional and longitudinal samples in this age range.

Cardiovascular risk factor prevention in black schoolchildren: two-year results of the "Know Your Body" program.

A five-year intervention study of the effectiveness of the "Know Your Body" program in reducing coronary heart disease risk factors among black students in the District of Columbia, who were in grades 4-6 at baseline, was begun in 1983. Nine schools were stratified on socioeconomic status and randomly assigned to control and intervention groups. The "Know Your Body" curriculum focuses on nutrition, fitness, and the prevention of cigarette smoking. At baseline, 1,234 students were eligible for the screening in which the following target risk factors were measured: systolic and diastolic blood pressures, ponderosity index, triceps skinfold thickness, postexercise pulse recovery rate, serum total and high density lipoprotein (HDL) cholesterol, and serum thiocyanate. After two years of intervention, results indicated that the program may have had a favorable impact on the following risk factors: systolic and diastolic pressures, HDL cholesterol, ratio of total to HDL cholesterol, fitness (postexercise pulse recovery rate), and smoking. Significant net changes in the favorable direction also were found for health knowledge and attitude toward smoking. Blood pressure reduction was associated with decreased ponderosity and improved fitness, and increased HDL cholesterol was associated with decreased ponderosity. These results are consistent with other evaluations of the "Know Your Body" program, suggesting that the program may be effective in reducing chronic disease risk in diverse school populations.