Enamel Bond Strength of New Universal Adhesive Bonding Agents.

PURPOSE: Universal bonding agents have been introduced for use as self-etch or etch-and-rinse adhesives depending on the dental substrate and clinician's preference. The purpose of this study was to evaluate the shear bond strength (SBS) of composite to enamel using universal adhesives compared to a self-etch adhesive when applied in self-etch and etch-and-rinse modes over time. METHODS AND MATERIALS: Extracted human third molars were used to create 120 enamel specimens. The specimens were ground flat and randomly divided into three groups: two universal adhesives and one self-etch adhesive. Each group was then subdivided, with half the specimens bonded in self-etch mode and half in etch-and-rinse mode. The adhesives were applied as per manufacturers' instructions, and composite was bonded using a standardized mold and cured incrementally. The groups were further divided into two subgroups with 10 specimens each. One subgroup was stored for 24 hours and the second for six months in 37°C distilled water and tested in shear. Failure mode was also determined for each specimen. RESULTS: A three-way analysis of variance (ANOVA) found a significant difference between groups based on bonding agent (p<0.001) and surface treatment (p<0.001) but not on time (p=0.943), with no significant interaction (p>0.05). Clearfil SE in etch-and-rinse and self-etch modes had more mixed fractures than either universal adhesive in either mode. CONCLUSIONS: Etching enamel significantly increased the SBS of composite to enamel. Clearfil SE had significantly greater bond strength to enamel than either universal adhesive, which were not significantly different from each other.

Patterns and predictors of asthma-related emergency department use in Harlem.

STUDY OBJECTIVES: To assess the roles of poor access to care, psychological risk factors, and asthma severity in frequent emergency department (ED) use. DESIGN: A cross-sectional survey. SETTING: Harlem Hospital Center ED and outpatient chest clinic. PARTICIPANTS: Three hundred seventy-five adult residents of Harlem, a predominantly African-American community in New York City. MEASUREMENTS: Asthma severity was assessed by self-reported symptoms using National Asthma Education and Prevention Program guidelines, health-care utilization, and psychometric scales. RESULTS: Respondents with more severe asthma were more likely to have a primary asthma care provider, and to have had more scheduled office visits for asthma in the year prior to the interview (mean number of visits for patients with severe asthma, 3.6 visits; moderate asthma, 2.4 visits; and mild asthma, 1.7 visits). Despite having a regular source of care, 69% of respondents identified the ED as their preferred source of care; 82% visited the ED more than once in the year prior to interview (median, four visits). Persons with moderate or severe asthma were 3.8 times more likely to be frequent ED users compared to those with mild asthma (odds ratio [OR], 3.8; 95% confidence interval [CI], 2.2 to 6.6). This was the strongest predictor of frequent ED use. Other predictors of ED use were number of comorbid disorders (OR, 1.5; 95% CI, 1.1 to 2.1) and self-reported global health in the year prior to the ED visit (OR, 1.8; 95% CI, 1.2 to 2.7). Psychological characteristics were not predictive of frequent ED use when controlling for disease severity. CONCLUSIONS: Frequent ED users present with serious medical conditions. They do not substitute physician care with ED care; they augment it to address serious health needs.

Effect of polymorphism of the beta(2)-adrenergic receptor on response to regular use of albuterol in asthma.

BACKGROUND: Regular use of inhaled beta-adrenergic agonists may have adverse effects in some asthma patients. Polymorphisms of the beta(2)-adrenergic receptor (beta(2)-AR) can affect its regulation; however, results of smaller studies of the effects of such polymorphisms on response to beta-agonist therapy have been inconsistent. METHODS: We examined the possible effects of polymorphisms at codons 16 (beta(2)-AR-16) and 27 (beta(2)-AR-27) on response to albuterol by genotyping 190 asthmatics who had participated in a trial of regular versus as-needed albuterol use. RESULTS: During the 16-week treatment period, patients homozygous for arginine (Arg/Arg) at beta(2)-AR-16 who used albuterol regularly had a small decline in morning peak expiratory flow (AM PEF). This effect was magnified during a 4-week run-out period, when all patients returned to as-needed albuterol only. By the end of the study, Arg/Arg subjects who had used albuterol regularly had an AM PEF 30.5 +/- 12.1 liters/min lower (p = 0.012) than Arg/Arg patients who had used albuterol as needed only. Subjects homozygous for glycine at beta(2)-AR-16 showed no such decline. Evening PEF also declined in the Arg/Arg regular but not in as-need albuterol users. No significant differences between regular and as-needed treatment were associated with polymorphisms at beta(2)-AR-27. CONCLUSIONS: Polymorphisms of the beta(2)-AR may influence airway responses to regular inhaled beta-agonist treatment.

The effect of polymorphisms of the beta(2)-adrenergic receptor on the response to regular use of albuterol in asthma.

Inhaled beta-adrenergic agonists are the most commonly used medications for the treatment of asthma although there is evidence that regular use may produce adverse effects in some patients. Polymorphisms of the beta(2)-adrenergic receptor (beta(2)-AR) can affect regulation of the receptor. Smaller studies examining the effects of such polymorphisms on the response to beta-agonist therapy have produced inconsistent results. We examined whether polymorphisms at codon 16 (beta(2)-AR-16) and codon 27 (beta(2)-AR-27) of the beta(2)-AR might affect the response to regular versus as-needed use of albuterol by genotyping the 190 asthmatics who had participated in a trial examining the effects of regular versus as needed albuterol use. During the 16-wk treatment period there was a small decline in morning peak expiratory flow in patients homozygous for arginine at B(2)-AR-16 (Arg/Arg) who used albuterol regularly. This effect was magnified during a 4-wk run out period, during which all patients returned to using as-needed albuterol, so that by the end of the study Arg Arg patients who had regularly used albuterol had a morning peak expiratory flow 30. 5 +/- 12.1 L/min lower (p = 0.012) than Arg/Arg patients who had used albuterol on an as needed basis. There was no decline in peak flow with regular use of albuterol in patients who were homozygous for glycine at beta(2)-AR-16. Evening peak expiratory flow also declined in the Arg/Arg patients who used albuterol regularly but not in those who used albuterol on an as-needed basis. No significant differences in outcomes between regular and as-needed treatment were associated with polymorphisms at position 27 of the beta(2)-AR. No other differences in asthma outcomes that we investigated occurred in relation to these beta(2)-AR polymorphisms. Polymorphisms of the beta(2)-AR may influence airway responses to regular inhaled beta-agonist treatment.

Environmentally responsive temperature instability in pediatric spinal cord injury.

OBJECTIVE: To study the frequency and clinical implications of environmentally responsive temperature instability in hospitalized pediatric patients with spinal cord injury (SCI). SETTING: A tertiary level SCI rehabilitation unit located in a free standing children's hospital in Wilmington, DE, USA. STUDY DESIGN: Temperature data and corresponding clinical responses were collected prospectively between January 1991 and June 1993. Fifty-four consecutive patients with SCI levels at or above T6 were admitted to the pediatric spinal cord injury rehabilitation unit over that time (4059 SCI days). METHODS: Hypothermic events were defined as oral temperatures less than 35.0 degrees C or rectal temperatures less than 35.6 degrees C. Hyperthermic events were defined as oral temperatures greater than 38.0 degrees C or rectal temperatures greater than 38.4 degrees C. The events and the clinical responses were reviewed retrospectively and were used for subsequent analysis if there was evidence of clinical response to environmental manipulation within 4 hours of case identification, and other potential etiologies of temperature fluctuation could be excluded. RESULTS: Sixty-five events of hypothermia (1.60%) and 14 events of hyperthermia (0.34%) were analyzed. Twelve patients (22%) accounted for all 79 events. Subjects with environmentally responsive temperature instability were more recently injured (P<0.001), had longer lengths of stay (P<0.001) and were more likely to be ventilator dependent (P<0.002) than those who did not have environmentally responsive temperature instability. There was no significant difference between the two groups in age, gender, level or etiology of the SCI. There were no adverse clinical outcomes as a result of the environmentally responsive temperature instability. CONCLUSIONS: Environmentally responsive temperature instability affects a select subset of pediatric aged spinal cord injured persons. Early recognition of the potential contribution of the environment to temperature fluctuation in this group has led to the successful utilization of a temperature instability protocol on our SCI unit.

Risk factors for excess mortality in Harlem. Findings from the Harlem Household Survey.

INTRODUCTION: In 1980, age-adjusted mortality rates in Central Harlem were the highest among New York City's 30 health districts. This population-based study was designed to describe the self-reported frequency of selected health conditions, behavioral risk factors, preventive health practices, and drug use in the Harlem community. METHODS: From 1992 to 1994, in-person interviews were conducted among 695 adults aged 18 to 65 years who were randomly selected from dwelling-unit enumeration lists for the Central Harlem health district. Descriptive statistics were computed for men and women separately, and compared to other population-based surveys. RESULTS: Self-reported medical insurance coverage in Harlem was unexpectedly high (74% of men, 86% of women) as was lifetime use of preventive health practices, e.g., blood cholesterol screening (58% of men, 70% of women). However, lifetime rates of substance use, e.g. crack cocaine (14%) and self-reported history of traumatic events, e.g., witnessing someone seriously injured or violently killed (49% of men, 21% of women) were also high in Harlem, especially in comparison to other populations. CONCLUSIONS: This study has identified important patterns of similarities and differences in risk behaviors between Harlem and other populations. Potential solutions to the health problems of Harlem may lie in the creation of strategies that operate at the community, municipal, and regional level, as well as at the level of individual behavior and risk-taking.

Predictors of reported condom use in central Harlem youth as conceptualized by the health belief model.

PURPOSE: To examine the relationship of reported condom use to specific sociodemographics, psychosocial variables, and perceptions of and motivations for condom use as conceptualized by the Health Belief Model. METHODS: This study performed a cross-sectional survey of 557 adolescents enrolled in a hospital-based pregnancy prevention program in an urban community hospital (Harlem Hospital). Multiple logistic regression analysis examined the combined relationship of the significant psychosocial variables to consistent condom use. RESULTS: Males were less likely than females to report teen-parent conflict and depression and more likely to report support for birth control, participation in community activities, and favorable attitudes toward delaying parenthood. Consistent with the Health Belief Model adjusting for age, the strongest predictors of consistent condom use were partner preference for condoms, perceived benefit of avoidance of pregnancy, male gender, and support for birth control (usually by a parent). CONCLUSIONS: The data on this urban, predominantly African-American sample of adolescents suggest the importance of the influences on specific motivations to use protection--that is, the wish to avoid pregnancy, human immunodeficiency virus/acquired immunodeficiency syndrome, and sexually transmitted diseases, although the mechanisms are still unclear. In addition, gender and the modifying effects of parental and partner support of the use of protection strongly influence the reported use of condoms by adolescents. These factors (in addition to psychosocial factors such as depression) may be important in planning interventions to increase condom use by sexually active teens.

PIP: The relationship of condom use to the sociodemographic, psychosocial, and cognitive factors included in the Health Belief Model was investigated in a cross-sectional study of 557 primarily low-income, African-American youth 12-19 years of age (mean age, 15.9 years) enrolled in a pregnancy prevention program at Harlem Hospital, New York City, during 1991-93. 74% reported ever having sex, 51% in the preceding 3 months. At last intercourse, 47% used no protection, 43% reported condom use, and 10% used another method. Males were more than 4 times as likely to report condom use than females. Males had more assets, more positive attitudes toward delaying parenthood, less teen-parent conflict, less depression, and more social support for birth control than females. Consistent with the Health Belief Model, the strongest predictors of consistent condom use (after adjustment for age) were partner preference for condoms, perceived benefit of avoidance of pregnancy, male gender, and social (mostly parental) support for birth control. These factors should be considered in the planning of interventions to increase condom use among sexually active teenagers.

Maternal exercise during pregnancy, physical fitness, and fetal growth.

The value of exercise during pregnancy is controversial; both benefits and risks have been hypothesized. As empiric evidence is scant, the issue was investigated in a prospective study that assessed the impact on fetal growth of maternal exercise in each trimester of pregnancy. A cohort of over 800 prenatal patients was recruited from obstetric practices in Pennsylvania and New York between January 1987 and June 1989. Subjects were interviewed at entry into care and recontacted at 28 and 36 weeks of gestation. In women with prior adverse outcomes or a lack of conditioning, the associations between maternal exercise and fetal growth were equivocal. In fit, low-risk, prenatal patients, exercise was positively associated with fetal growth. With low-moderate exercise levels, the adjusted mean birth weights were about 100 g higher than in nonexercisers (117 g; 95% confidence interval 17 to 217 g). With heavier exercise, larger birth weight increments were seen, close to 300 g in those who exercised throughout pregnancy at levels of about 2,000 kcal/week in energy expenditure (276 g; 95% confidence interval 54 to 497 g). These results suggest that the guidelines issued by the American College of Obstetricians and Gynecologists may be too stringent for well-conditioned, low-risk, prenatal patients. Additional research to define safe limits more precisely seems warranted.