Innovative playgrounds: use, physical activity, and implications for health

OBJECTIVES

The aim of the study is to assess the use and levels of moderate-to-vigorous physical activity (MVPA) occurring in innovative playgrounds in London vs. traditional playgrounds in the US in neighborhoods with a similar population density.

STUDY DESIGN

This is a cross-sectional observational study.

METHODS

We selected a sample of London playgrounds based on their innovative design. One group of eight playgrounds was matched to the US playgrounds by size and population density; a second group of very large London playgrounds was matched only by population density. Playground use and person-hours of MVPA were measured using direct observation at similar times of the day and days of the week in all locations.

RESULTS

The number of playground visit hours was 58% higher in London than in the US (394 vs 249). The matched London playgrounds had 37.8% more children and 129% more adults who were, respectively, engaging in 90% and 116% more MVPA. While the London playgrounds were nearly 8.5 times larger than the US ones, they attracted a total of 5.8 times more visitors (1399 vs 243, P < .0001), and this included 10 times as many adults (679 vs. 66, P < .0001) and 7.5 times more seniors (23 vs. 3). The London playgrounds included more amenities targeting adults.

CONCLUSIONS

The design of an innovative playground was associated with the amount of MVPA in similar-sized playgrounds, but the size of the playground was more strongly associated with the number of visitors. It is as important to design playgrounds for adults as it is for children to increase visit hours.

Development of an autologous canine cancer vaccine system for resectable malignant tumors in dogs

While conventional therapies exist for canine cancer, immunotherapies need to be further explored and applied to the canine setting. We have developed an autologous cancer vaccine (K9-ACV), which is available for all dogs with resectable disease. K9-ACV was evaluated for safety and immunogenicity for a variety of cancer types in a cohort of companion dogs under veterinary care. The autologous vaccine was prepared by enzymatic digestion of solid tumor biopsies. The resultant single cell suspensions were then UV-irradiated resulting in immunogenic cell death of the tumor cells. Following sterility and endotoxin testing, the tumor cells were admixed with CpG ODN adjuvant and shipped to the participating veterinary clinics. The treating veterinarians then vaccinated each patient with three intradermal injections (10 million cells per dose) at 30-day intervals (one prime and two boost injections). In a cohort of 20 dogs completing the study, 17 dogs (85%) developed an augmented IgG response to autologous tumor antigens as demonstrated using western blot analysis of pre- and post-peripheral blood samples. We also report several dogs have lived beyond expected survival time based on previously published data. In summary, K9-ACV is an additional option to be considered for the treatment of dogs with resectable cancer.

The collectivity of sexual behaviour

Human behaviour can be viewed as a collective phenomenon, determined partly by the group to which individuals belong. Collectivities of health behaviour have been found in alcohol consumption, hypertension, obesity, mental illness, and sodium intake in that the average level of risk is associated with the percentage of individuals at extremely high risk.

The goal was to investigate whether sexual behaviour may be collectively determined. A cross-sectional US survey was conducted.

Across 45 states, the mean number of lifetime sex partners excluding persons with >10, >20, and >40 lifetime partners was strongly associated with the proportion with >10, > 20 and > 40 lifetime sex partners, respectively, among men and women.

Sexual activity may represent collectively determined behaviour. If so, interventions to reduce high-risk sexual behaviour to prevent HIV or sexually transmitted diseases (STDs) may be more effective if they address the entire population, rather than target only those at the extremes of risk.

Obesity prevention at the point of purchase

The point of purchase is when people may make poor and impulsive decisions about what and how much to buy and consume. Because point of purchase strategies frequently work through non-cognitive processes, people are often unable to recognize and resist them. Because people lack insight into how marketing practices interfere with their ability to routinely eat healthy, balanced diets, public health entities should protect consumers from potentially harmful point of purchase strategies. We describe four point of purchase policy options including standardized portion sizes; standards for meals that are sold as a bundle, e.g. 'combo meals'; placement and marketing restrictions on highly processed low-nutrient foods; and explicit warning labels. Adoption of such policies could contribute significantly to the prevention of obesity and diet-related chronic diseases. We also discuss how the policies could be implemented, along with who might favour or oppose them. Many of the policies can be implemented locally, while preserving consumer choice.

Use of neighbourhood parks: does socio-economic status matter? A four-city study

OBJECTIVES

To determine if neighbourhood socio-economic status (SES) is associated with park use and park-based physical activity.

STUDY DESIGN

Cross-sectional study.

METHODS

The use and characteristics of 24 neighbourhood parks in Albuquerque, Chapel Hill/Durham, Columbus and Philadelphia were observed systematically in three seasons (spring, summer and autumn), with nearly 36,000 park users observed. Twelve parks were in high-poverty neighbourhoods and 12 parks were in low-poverty neighbourhoods. In total, 3559 park users and 3815 local residents were surveyed. Park incivilities were assessed and park administrators were interviewed about management practices.

RESULTS

The size and number of facilities in parks in high-poverty neighbourhoods were similar to those in parks in low-poverty neighbourhoods, but the former had more hours of programming. Neighbourhood poverty level, perception of safety and the presence of incivilities were not associated with the number of park users observed. However, programmed activities and the number of activity facilities were strongly correlated with park use and energy expended in the park.

CONCLUSIONS

The finding that park programming is the most important correlate of park use and park-based physical activity suggests that there are considerable opportunities for facilitating physical activity among populations of both high- and low-poverty areas.

The Tractability of CSP Classes Defined by Forbidden Patterns

The constraint satisfaction problem (CSP) is a general problem central to computer science and artificial intelligence. Although the CSP is NP-hard in general, considerable effort has been spent on identifying tractable subclasses. The main two approaches consider structural properties (restrictions on the hypergraph of constraint scopes) and relational properties (restrictions on the language of constraint relations). Recently, some authors have considered hybrid properties that restrict the constraint hypergraph and the relations simultaneously. Our key contribution is the novel concept of a CSP pattern and classes of problems defined by forbidden patterns (which can be viewed as forbidding generic sub-problems). We describe the theoretical framework which can be used to reason about classes of problems defined by forbidden patterns. We show that this framework generalises certain known hybrid tractable classes. Although we are not close to obtaining a complete characterisation concerning the tractability of general forbidden patterns, we prove a dichotomy in a special case: classes of problems that arise when we can only forbid binary negative patterns (generic sub-problems in which only disallowed tuples are specified). In this case we show that all (finite sets of) forbidden patterns define either polynomial-time solvable or NP-complete classes of instances.

Contextual influences on eating behaviours: heuristic processing and dietary choices

This paper reviews some of the evidence that dietary behaviours are, in large part, the consequence of automatic responses to contextual food cues, many of which lead to increased caloric consumption and poor dietary choices. We describe studies that illustrate how these automatic mechanisms underlie eating behaviours, as well as evidence that individuals are subject to inherent cognitive limitations, and mostly lack the capacity to consistently recognize, ignore or resist contextual cues that encourage eating. Restaurants and grocery stores are the primary settings from which people obtain food. These settings are often designed to maximize sales of food by strategically placing and promoting items to encourage impulse purchases. Although a great deal of marketing research is proprietary, this paper describes some of the published studies that indicate that changes in superficial characteristics of food products, including packaging and portion sizes, design, salience, health claims and labelling, strongly influence food choices and consumption in ways for which people generally lack insight. We discuss whether contextual influences might be considered environmental risk factors from which individuals may need the kinds of protections that fall under the mission of public health.

Nutrition standards for away-from-home foods in the USA

Away-from-home foods are regulated with respect to the prevention of food-borne diseases and potential contaminants, but not for their contribution to dietary-related chronic diseases. Away-from-home foods have more calories, salt, sugar and fat, and include fewer fruits and vegetables than recommended by national nutrition guidelines. Thus, frequent consumption of away-from-home foods contributes to obesity, hypertension, diabetes, heart disease, and cancer. In light of this, many localities are already adopting regulations or sponsoring programs to improve the quality of away-from-home foods. We review the rationale for developing nutritional performance standards for away-from-home foods in light of limited human capacity to regulate intake or physiologically compensate for a poor diet. We offer a set of model performance standards to be considered as a new area of environmental regulation. Models for voluntary implementation of consumer standards exist in the environmental domain and may be useful templates for implementation. Implementing such standards, whether voluntarily or via regulations, will require addressing a number of practical and ideological challenges. Politically, regulatory standards contradict the belief that adults should be able to navigate dietary risks in away-from-home settings unaided.

Granzyme B-mRNA expression by equine lymphokine activated killer (LAK) cells is associated with the induction of apoptosis in target cells

Lymphokine-activated killer (LAK) cells are a subset of cytotoxic cells capable of lysing freshly isolated tumor cells. While LAK activity is typically measured using the (51)Cr-release assay, here we used a non-radioactive flow cytometric method to demonstrate equine LAK activity. Equine peripheral blood mononuclear cells (PBMC) were stimulated in vitro with recombinant human interleukin 2 (hIL-2) to generate LAK cells. An equine tumor cell line, EqT8888, labeled with carboxyfluorescein succinimidyl ester (CFSE) was used as target cells. Following incubation of the targets with different concentrations of LAK cells, Annexin V was added to identify the early apoptotic cells. With increasing effector to target cell ratios, EqT8888 apoptosis was increased. We also measured interferon-gamma, granzyme B and perforin mRNA expression in the LAK cell cultures as possible surrogate markers for cytotoxic cell activity and found granzyme B mRNA expression correlated best with LAK activity. Also, we found that the reduced LAK activity of young horses was associated with decreased granzyme B mRNA expression. Our results indicate that fluorescence-based detection of LAK cell activity provides a suitable non-radioactive alternative to (51)Cr-release assays and mRNA expression of granzyme B can be used as surrogate marker for these cytotoxic cells.

Inside the fitness for work consultation: a qualitative study

BACKGROUND

Evidence now suggests that work is generally good for physical and mental health and well-being. Worklessness for whatever reason can lead to poorer physical and mental health. The role of the general practitioner (GP) in the management of fitness for work is pivotal.

AIMS

To understand the interaction between GP and patient in the fitness for work consultation. This study forms part of a larger research project to develop a learning programme for GPs around the fitness for work consultation based on behaviour change methodology.

METHODS

A qualitative study set in South Wales. Structured discussion groups with seven GPs. Two sessions each lasting 3 h were conducted to explore the GP and patient interaction around the fitness for work consultation. Multiple methods were used to enhance engagement. Thematic analysis was used to analyse the data.

RESULTS

Four major themes emerged from the meetings: role legitimacy, negotiation, managing the patient and managing the systems. Within these, subthemes emerged around role legitimacy. 'It's not my job', 'It's not what I trained for' and the 'shifting agenda' Negotiation was likened to 'A polite tug of war' and subthemes around decision making, managing the agenda and dealing with uncertainty emerged.

CONCLUSIONS

This study starts to unravel the complexity of the fitness for work consultation. It illustrates how GPs struggle with the 'importance' of their role and 'confidence' in managing the fitness for work consultation. It addresses the skillful negotiation that is required to manage the consultation effectively.

Obesity and the built environment: changes in environmental cues cause energy imbalances

The past 30 years have seen dramatic changes in the food and physical activity environments, both of which contribute to the changes in human behavior that could explain obesity. This paper reviews documented changes in the food environment, changes in the physical activity environment and the mechanisms through which people respond to these environments, often without conscious awareness or control. The most important environmental changes have been increases in food accessibility, food salience and decreases in the cost of food. The increases in food marketing and advertising create food cues that artificially stimulate people to feel hungry. The existence of a metabolic pathway that allows excess energy to be stored as fat suggests that people were designed to overeat. Many internal mechanisms favor neurophysiologic responses to food cues that result in overconsumption. External cues, such as food abundance, food variety and food novelty, cause people to override internal signals of satiety. Other factors, such as conditioning and priming, tie food to other desirable outcomes, and thus increase the frequency that hunger is stimulated by environmental cues. People's natural response to the environmental cues are colored by framing, and judgments are flawed and biased depending on how information is presented. People lack insight into how the food environment affects them, and subsequently are unable to change the factors that are responsible for excessive energy consumption. Understanding the causal pathway for overconsumption will be necessary to interrupt the mechanisms that lead to obesity.

Macrophage-mediated neuroprotection and neurogenesis in the olfactory epithelium

Resident and recruited olfactory epithelial macrophages participate in the regulation of the survival, degeneration, and replacement of olfactory sensory neurons (OSNs). We have reported that liposome-encapsulated clodronate (Lip-C) induced selective and statistically significant depletion of macrophages in the OE of sham and 48 h OBX mice (38 and 35%, respectively) that resulted in increased OSN apoptosis and decreased numbers of mature OSNs and proliferating basal cells compared to controls (Lip-O). The aim of this study was to identify molecular mechanisms by which the selective depletion of macrophages in the OE resulted in these cellular changes by using a microarray expression pattern analysis. A 2x2 ANOVA identified 4,085 overall significantly (P < 0.01) regulated genes in the OE of Lip-O and Lip-C sham and 48 h OBX mice, and further statistical analysis using pairwise comparisons identified 4,024 genes that had either a significant (P < 0.01) treatment main effect (n = 2,680), group main effect (n = 778), or interaction effect (n = 980). The mean hybridization signals of immune response genes, e.g., Cxcr4, and genes encoding growth factors and neurogenesis regulators, e.g., Hdgf and Neurod1, respectively, were primarily lower in Lip-C mice compared with Lip-O mice. Apoptosis genes, e.g., Bak1, were also differentially regulated in Lip-C and/or OBX mice. Expression patterns of selected genes were validated with real-time RT-PCR; immunohistochemistry was used to localize selected gene products. These results identified the differential regulation of several novel genes through which alternatively activated macrophages regulate OSN progenitor cell proliferation, differentiation, and maturation, and the survival of OSNs.

Suburban sprawl and physical and mental health

OBJECTIVE

To study the association between objective measures of suburban sprawl and chronic medical conditions and mental health disorders in the USA.

METHODS

Cross-sectional analysis of survey data merged with objective measures of suburban sprawl. Outcomes are self-reported medical conditions, mental health disorders and health-related quality of life.

RESULTS

Sprawl significantly predicts chronic medical conditions and health-related quality of life, but not mental health disorders. An increase in sprawl from one standard deviation less to one standard deviation more than average implies 96 more chronic medical problems per 1000 residents, which is approximately similar to an aging of the population of 4 years.

CONCLUSIONS

A robust association between sprawl and physical (but not mental) health suggests that suburban design may be an important new avenue for health promotion and disease prevention.

Idiopathic pneumonia syndrome after bone marrow transplantation: the role of pre-transplant radiation conditioning and local cytokine dysregulation in promoting lung inflammation and fibrosis

Pulmonary complications and graft-vs.-host disease (GVHD) remain severe threats to survival after bone marrow transplantation (BMT). Idiopathic pneumonia syndrome (IPS) accounts for nearly 50% of all the cases of interstitial pneumonitis after BMT. IPS is characterized by an early inflammatory phase followed by chronic inflammation and fibrosis of lung tissue; however, the immunopathogenesis of this disease is not yet clearly understood. This biphasic syndrome has been reported to be associated with pre-transplant radiation conditioning in some studies while others have suggested that GVHD or autoimmune phenomena may be responsible for its development. The early post-BMT phase is characterized by the presence of inflammatory cytokines whose net effect is to promote lymphocyte influx into lungs with minimal fibrosis, that leads to an acute form of graft-vs.-host reaction-mediated pulmonary tissue damage. Gradual changes over time in leucocyte influx and activation lead to dysregulated wound repair mechanisms resulting from the shift in the balance of cytokines that promote fibrosis. Using data from new animal models of IPS and information from studies of human IPS, we hypothesize that cytokine-modulated immunological mechanisms which occur during the acute and chronic phases after bone marrow transplantation lead to the development of the progressive, inflammatory, and fibrotic lung disease typical of idiopathic pneumonia syndrome.

Bleomycin-induced pulmonary fibrosis is independent of eosinophils

Eosinophils have been shown to increase in tissues during many fibrotic conditions and consequently have been suggested to contribute to the development of fibrosis. This study tested the hypothesis that eosinophils are essential in the development of lung fibrosis in mice in response to bleomycin (BLM). Anti-IL-5 antibody was administered intraperitoneally into mice 2 h prior to endotracheal BLM inoculation and thereafter, every other day. Lung eosinophilia was evaluated by measurement of eosinophil peroxidase activity and confirmed by eosinophil counts in histologic sections. Lung fibrosis was evaluated by hydroxyproline content and confirmed by collagen staining in histological sections. Results demonstrated that BLM induced pronounced lung eosinophilia, which was maximal 7 days after BLM treatment and remained elevated through day 14, in C57B1/6 SCID mice and CBA/J mice. In contrast, eosinophilia was a minor component in the lungs of wildtype C57B1/6 mice after BLM treatment, although lung fibrosis developed similarly in all three strains of mice. Treatment with anti-IL-5 completely abrogated eosinophilia but failed to block pulmonary fibrosis induced by BLM in all mouse strains, including C57B1/6 SCID, wildtype C57B1/6 mice, and CBA/J mice. Analysis of cytokine mRNA by RNase-protection assay in C57B1/6 SCID mice indicated that BLM treatment caused enhanced expression of the cytokines, TNF-alpha, and IL-6 at days 3, 7, and 14 post-BLM inoculation, regardless of whether eosinophils were depleted by anti-IL-5. Finally, the importance of eosinophils in lung fibrosis was examined in IL-5 gene knockout mice (IL-5tm1Kopf). BLM treatment induced significant lung fibrosis in IL-5 knockout mice in the absence of eosinophilia. These findings indicate that eosinophils are not an absolute requirement for BLM-induced pulmonary fibrosis in the mouse.

Participation in a school-based sexually transmitted disease screening program

BACKGROUND

A school-based chlamydia screening program was offered repeatedly in three Louisiana public high schools in an effort to expand sexually transmitted disease screening services for adolescents.

GOAL

To describe participation of a fixed cohort of students to elucidate the impact of screening on chlamydia prevalence.

STUDY DESIGN

Five opportunities for chlamydia testing were offered in 3 schools during 3 school years (1995-1996, 1996-1997, 1997-1998). Only students with parental consent could be tested. Students consistently enrolled during the 3 years (n = 1475) were included in this analysis.

RESULTS

During the 3 school years, parental consent was cumulatively obtained for 1443 students (97.8%), and 1305 students (88.5%) were tested at least once. Of those tested, 81.1% tested more than once. The prevalence of Chlamydia trachomatis infection at first test among students who tested more than once was 1.8% for males and 7.7% for females. Among students tested only once, 6.2% of males and 12.7% of females had chlamydial infection. Among students tested more than once, no significant difference in C. trachomatis prevalence was associated with repeat screenings. Incidence rates per 1000 person-months were 4.3 (2.2, males; 7.1, females; P < 0.0001). Reinfections explained only 5.6% of all incident cases.

CONCLUSION

The documented high response from both parents and students to this school-based chlamydia screening program offers great promise for sexually transmitted disease control among adolescents. Overall, C. trachomatis prevalence was two times higher among students testing only once than among those testing more than once. Routine and continued availability of school-based chlamydia screening programs can potentially reduce the burden of disease among adolescents.

Strategies for syphilis prevention: findings from surveys in a high-incidence area

BACKGROUND

The persistence of syphilis in the United States suggests that a better understanding is needed of the potential for various public health approaches to prevent the spread of the disease.

STUDY DESIGN

The authors conducted surveys of 92 persons with early syphilis, 56 uninfected sexual contacts, and 143 neighborhood controls in the Baton Rouge, Louisiana area. The surveys collected information regarding sexual behavior, access to and use of healthcare services, encounters at sites at which serologic screening for syphilis could be done, and exposure to interventions designed to prevent HIV infection.

RESULTS

All groups reported high-risk sexual behavior. Cases and contacts were more likely than controls to report two or more sex partners in the previous year, but the three groups were similar in the percentage reporting five or more sex partners. Cases had poor access to health care and by some measures this access was less than that of controls. The potential screening site visited most frequently by cases was the public hospital emergency room (40%). Cases were less likely to have been exposed to programs designed to prevent HIV infection than uninfected contacts and controls combined (odds ratios, 0.51-0.66).

CONCLUSIONS

Persons with syphilis were not unlike others in their neighborhoods, suggesting that syphilis is a sentinel event that indicates an entire neighborhood is at risk. Improvements in access to health care for sexually transmitted disease-related symptoms, screening in sites such as public hospital emergency rooms, and emphasizing sexual risk-reduction interventions may limit the spread of syphilis in these neighborhoods. To prevent syphilis in the long term, public health programs should also try to better understand and change other community-level socioeconomic factors that influence sexual behavior.

Evidence of a structural effect for alcohol outlet density: a multilevel analysis

BACKGROUND

Ecological studies reveal that alcohol-related outcomes tend to occur in high alcohol outlet density neighborhoods. The ecological design of these studies limits the interpretation of the findings in terms of the level of the effect. The effect of alcohol outlet density could be related to greater individual access to alcohol, an individual level effect, or to the grouping of drinkers by neighborhood, a structural effect at the neighborhood level.

METHODS

To differentiate between individual and neighborhood level possibilities, we conducted a multilevel study. Individual distance to the closest alcohol outlet was the individual level measure of the effect of alcohol outlet density, whereas the mean distance to the closest alcohol outlet for all individuals within a census tract was the neighborhood level measure for the effect of alcohol outlet density. We analyzed telephone surveys of 2604 telephone households within 24 census tracts stratified by poverty status and alcohol outlet density. Individual distance to alcohol outlets, age, sex, race/ethnicity, and level of education were entered as individual level covariates, and their corresponding aggregated means were entered as census tract level covariates (i.e., mean distance to outlets, mean age, percentage male, percentage Black, mean education).

RESULTS

Analysis of variance revealed that 16.2% of the variance in drinking norms and 11.5% of the variance in alcohol consumption were accounted for at the census tract level. In multivariate hierarchical analysis, individual distance to the closest alcohol outlet was unrelated with drinking norms and alcohol consumption, whereas mean distance to the closest alcohol outlet demonstrated a negative relation with drinking norms (betae = -5.50+/-2.37) and with alcohol consumption (betae = -0.477+/-0.195); that is, the higher the mean distance to the closest alcohol outlet, the lower the mean drinking norms score and mean level of alcohol consumption.

CONCLUSIONS

The findings suggest that the effect of alcohol outlet density on alcohol-related outcomes functions through an effect at the neighborhood level rather than at the individual level. Problem drinkers tend to be grouped in neighborhoods, an effect predicted by alcohol outlet density.

A structural model of health behavior: a pragmatic approach to explain and influence health behaviors at the population level

BACKGROUND

Behavior is influenced by individual-level attributes as well as by the conditions under which people live. Altering policies, practices, and the conditions of life can directly and indirectly influence individual behavior. This paper builds on existing ecological theories of health behavior by specifying structural mechanisms by which population-level factors effect change in individual health behaviors.

METHODS

This paper moves ecological theory from model building to a pragmatic characterization of structural interventions. We examined social and environmental factors beyond individual control and mechanisms as to how they influence behavior.

RESULTS

Four categories of structural factors are identified: (1) availability of protective or harmful consumer products, (2) physical structures (or physical characteristics of products), (3) social structures and policies, and (4) media and cultural messages. The first three can directly influence individuals through facilitating or constraining behavior. The fourth, media, operates by changing individual-level attitudes, beliefs, and cognitions, as well as group norms.

CONCLUSION

Interventions that target the four identified structural factors are a means to provide conditions that not only reduce high-risk behavior but also prevent the adoption of high-risk behaviors. Structural interventions are important and underutilized approaches for improving our nation's health.

An STD/HIV prevention intervention framework

Historically, interventions to prevent STD/HIV transmission have been categorized by program methodology rather than defining the content and nature of the intervention. A new taxonomy is needed to help expand the scope of interventions that can be used to prevent STD and HIV transmission. The taxonomy defines two major types of interventions, individual-level and structural level. The former targets risk factors attributable to individuals. Structural interventions target conditions outside the control of the individual. Individual-level interventions focus on counseling, screening, and treatment. They include psychological and biological interventions. Structural-level interventions address accessibility of relevant consumer products (condoms, needles), physical structures (e.g. blighted and abandoned housing, lighting, design of social facilities), social structures (policies that facilitate or constrain behaviors such as supervision of youth, and enforcement of alcohol beverage laws); and media messages (messages and images in the broadcast and print media that portray high-risk behaviors as positive and without serious consequences). A new taxonomy not only clarifies the content of preventive interventions but highlights neglected strategies involving individual biological interventions and structural interventions to prevent STD/HIV transmission.

Role of virus replication in a murine model of AIDS-associated interstitial pneumonitis

One of the major complications of HIV infection is the development of interstitial pneumonitis (IP). IP is characterized by lymphocytic infiltration of the lung and may lead to respiratory failure in some cases. The etiology of IP is unknown although it is likely the result of an antiviral or autoimmune response occurring in the lung. To determine the role of viral replication in the development of IP, AZT was evaluated for the ability to inhibit development of lung inflammation in a murine model of retrovirus-associated IP. Mice were infected with LP-BM5 retrovirus, which induces murine AIDS. Infected mice develop IP by 4 weeks postinfection characterized by infiltration of the lung with activated T cells, B cells, and macrophages. Virus could be detected in the lungs of these mice by 2 weeks postinfection and persisted throughout the course of disease. To determine if reduction in viral load affected the disease process, infected mice were treated with AZT for varying periods postinfection and analyzed for the development of IP. Treatment with AZT resulted in a treatment time-dependent reduction of viral RNA in the lungs of infected mice compared to untreated infected mice. The reduction of viral burden in the lungs correlated with a reduction in the severity of IP and decreased production of the proinflammatory cytokines interleukin (IL)-1 beta and interferon (IFN)-gamma. These results suggest that continuous viral replication in the lung contributes to the pathogenesis of IP.

Role of T cell subsets in the development of AIDS-associated interstitial pneumonitis in mice

Idiopathic interstitial pneumonitis (IP), characterized by lymphocytic infiltration of the lung and pulmonary dysfunction, is a major noninfectious complication of human immunodeficiency virus (HIV) infection. The role of the CD4+ and CD8+ T cell populations and INF-gamma in the development of IP were analyzed using a murine model of retroviral-associated IP. Infected mice depleted of CD8+ T cells developed IP similarly to untreated infected mice, suggesting that the CD8+ T cell population does not play a role in IP. Furthermore, depletion of CD8+ T cells did not alter the level of viral RNA in lungs, suggesting that cytotoxic T cells may not serve a role in controlling virus burden in lungs. In contrast, depletion of CD4+ T cells in infected mice prevented the development of IP and inhibited inflammatory cytokine expression, suggesting that CD4+ T cells are important for the development of IP. IFN-gamma -/- mice infected with virus for 10 weeks developed IP, although the severity of lymphocytic infiltration was substantially reduced compared to infected wild-type mice. The data suggest that persistent viral antigen in the lung may drive a CD4+ T cell-mediated immune response, resulting in the chronic production of IFN-gamma which amplifies a chronic inflammatory response in the lung resulting in tissue injury.

Repeated school-based screening for sexually transmitted diseases: a feasible strategy for reaching adolescents

OBJECTIVES

To determine whether repeated school-based screening and treatment for chlamydia and gonorrhea will decrease the prevalence of infection among students.

DESIGN

At three high schools serving over 2000 students, all 9th through 12th grade students were given the opportunity to be tested during three consecutive school years for chlamydia and gonorrhea, using urine ligase chain reaction tests. Five comparable schools with 5063 students enrolled served as wait-listed controls.

SETTING

Eight urban public high schools in Louisiana.

PARTICIPANTS

Annually, 52% to 65% of all enrolled students participated; among those enrolled in schools for > or = 2 years, 83.4% of students were tested at least once.

INTERVENTION

Education of all students; counseling and treatment of infected students with oral single-dose antibiotic therapy.

MAIN OUTCOME MEASURE

Prevalence of Chlamydia trachomatis and gonorrhea infection.

RESULTS

At first test, 286 (11.5%) of 2497 girls and 143 (6.2%) of 2308 boys were infected with chlamydia, and 48 (2.5%) of 1883 girls and 19 (1.2%) of 1628 boys had gonorrhea. Over 90% of infections were asymptomatic. With repeated testing, chlamydia prevalence among boys dropped to half the rate of comparison schools (3.2% vs 6.4%). Among girls chlamydia prevalence declined only slightly (10.3% vs 11. 9% in comparison schools).

CONCLUSION

There are high rates of asymptomatic sexually transmitted diseases (STDs) in the general urban school population. Repeated screening and treatment are associated with declines in chlamydia prevalence among boys. Expansion of STD screening and treatment programs to school settings is likely to be a critical component of a national strategy to control bacterial STDs.

School-based screening for sexually-transmitted diseases

Chlamydia and gonorrhea are the two most common bacterial sexually transmitted diseases (STDs) disproportionately affecting adolescents. Compared to other states, in 1997, Louisiana ranked fifth and seventh in reported case rates of gonorrhea and chlamydia, respectively. These two diseases can now be diagnosed with a urine test using DNA amplification technology, making it possible to identify asymptomatically infected persons without having to conduct a physical examination. In a school screening program piloted in Louisiana school-based health centers, all students in 12 urban public high schools were offered the urine test. Most infected students had no symptoms. The infection rate in girls was generally at least twice as high as among boys. Over time, the prevalence of chlamydia infection decreased. School-based screening is feasible and acceptable and can identify a large number of asymptomatic, infected youth. Screening programs which target asymptomatic youth should be expanded in order to reduce the burden of chlamydia and gonorrhea in our communities.

Condom availability for HIV/STD prevention

Condom availability is a structural intervention that increases access to condoms. It is the most important strategy for the prevention of the sexual transmission of HIV/STDs in developing countries. While it is an integral component of many prevention programs, it is considered controversial in high school settings and its role in a variety of HIV/STD prevention interventions has been understudied, understated, and/or unacknowledged. Condom availability as an HIV/STD prevention strategy needs to be reprioritized and should be considered a critical foundation of all programs to prevent the sexual transmission of HIV.

Idiopathic pneumonia syndrome after allogeneic bone marrow transplantation in mice. Role of pretransplant radiation conditioning

Idiopathic pneumonia syndrome (IPS) is a significant clinical problem encountered among patients treated with bone marrow transplantation (BMT). IPS is identified as an inflammatory lung disease characterized by diffuse interstitial pneumonitis and alveolitis leading to interstitial fibrosis in the absence of an identifiable infectious agent. In an earlier study we characterized a murine model of IPS following allogeneic BMT that exhibits several features of human IPS. In this report we show that the lung represents a unique target of post-BMT disease in this model. The kinetics of developing lung disease were found to be markedly different from the kinetics of graft-versus-host disease in other tissues such as liver, colon, ear, skin, and tongue. Mice transplanted by our standard protocol with T-cell-depleted semiallogeneic donor bone marrow plus donor spleen cells in the absence of pretransplant radiation conditioning did not develop lung inflammation or fibrosis characteristic of IPS. Pretransplant radiation conditioning in the absence of BMT also failed to cause IPS, demonstrating an important role for radiation conditioning in the development of BMT-related IPS. The occurrence of lung disease post-BMT was found to be dependent on radiation conditioning in a dose-dependent manner. Finally, thoracic irradiation alone was demonstrated to be sufficient in causing IPS in mice transplanted with bone marrow plus spleen cells, albeit with reduced severity. Based on these findings, we conclude that pretransplant radiation conditioning plays an important role in the development of IPS following allogeneic BMT.

Implementation of condom social marketing in Louisiana, 1993 to 1996

OBJECTIVES

This article describes the implementation and impact of the first statewide condom social marketing intervention in the United States.

METHODS

A statewide social marketing program made condoms freely available in 93 public health clinics, 39 community mental health centers, 29 substance abuse treatment sites, and more than 1000 businesses in neighborhoods with high rates of sexually transmitted diseases (STDs) and HIV. Surveys about condom use were conducted annually.

RESULTS

Between 1994 and 1996, more than 33 million condoms were distributed without significant opposition. Over time, self-reported condom use at the last sexual encounter increased among African American women (from 28% in 1994 to 36% in 1996), particularly African American women with 2 or more sex partners (from 30% to 48%). Condom use at the last sexual encounter increased among African American men (from 40% in 1994 to an average of 54% in 1996). The number of reported sex partners did not increase.

CONCLUSIONS

Condom social marketing can be successfully implemented in the United States. The widespread availability of free condoms is associated with increased condom use, particularly among persons at high risk for STDs and HIV.

T cell independence of bleomycin-induced pulmonary fibrosis

The role of T cells and cytokines in bleomycin (BLM)-induced fibrosis was evaluated in susceptible and resistant strains of normal and SCID mice. Histology and hydroxyproline analysis showed that BLM induced pulmonary fibrosis in C57BL/6 and (C57BL/6 x BALB/c)F1 mice, whereas BALB/c mice were resistant to the disease. To test whether lymphocytes were required for the induction of BLM-induced pulmonary fibrosis, SCID mice were injected intratracheally with BLM and evaluated for the development of pulmonary inflammation and fibrosis. Similar morphological changes and increases in hydroxyproline were observed in both C57BL/6 SCID and (C57BL/6 x CB.17)F1 SCID animals compared to those seen in wild-type C57BL/6 and (C57BL/6 x BALB/c)F1 mice. In contrast, CB.17 SCID mice, which are genetically similar to BALB/c mice, were resistant to disease induction. Analysis of the cellular infiltrate in BLM-treated C57Bl/6 SCID mice confirmed a lack of T cells in the lungs of SCID mice and demonstrated a pronounced accumulation of eosinophils in areas of developing pulmonary fibrosis. NK cells were significantly elevated in untreated SCID mice and did not increase further after BLM treatment. Analysis of selected cytokines 1 day after initiation of BLM-induced pulmonary fibrosis indicated that the levels of TNF-alpha and IFN-gamma appeared to segregate with fibrosis in both the SCID and wild-type mice. The data demonstrate that T cells are not required for the induction of fibrosis by BLM and suggest that responses by non-lymphoid cells may be sufficient for the induction of fibrosis.

Evaluation of the Gen-Probe PACE 2 assay for the detection of asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees

BACKGROUND

The LET and Gen-Probe PACE 2 assay are used to screen male arrestees for evidence of infection with chlamydia and gonorrhea in the intake/booking area of the Jefferson Parish Correctional Center.

GOAL OF THIS STUDY

To determine the accuracy of the Gen-Probe PACE 2 assay for the detection of asymptomatic infection with Chlamydia trachomatis and Neisseria gonorrhoeae infections in male arrestees.

STUDY DESIGN

From December 1993 to March 1994, 196 arrestees younger than 22 years were screened with the Gen-Probe PACE 2 assay and McCoy shell vial culture for Chlamydia trachomatis. From April to October 1994, 444 arrestees of all ages were screened with the Gen-Probe PACE 2 assay and standard culture for Neisseria gonorrhoeae. The sensitivity, specificity, and predictive values of the Gen-Probe PACE 2 assay, compared with culture, were calculated with 95% confidence intervals.

RESULTS

The Gen-Probe PACE 2 assay compared with culture had a sensitivity, specificity, and positive predictive value for Chlamydia trachomatis of 84%, 99%, and 93% and for Neisseria gonorrhoeae of 54%, 99.5%, and 78%.

CONCLUSION

The Gen-Probe PACE 2 assay is useful for screening young males in this jail setting and is more accurate for detecting Chlamydia trachomatis compared with Neisseria gonorrhoeae.

A geographic relation between alcohol availability and gonorrhea rates

BACKGROUND AND OBJECTIVES

The availability of alcohol measured as alcohol outlet density is associated with numerous alcohol-related outcomes in small area analysis. A number of studies suggest that high-risk sexual behavior should also be considered an alcohol-related outcome.

GOAL OF THIS STUDY

To assess the geographic relationship between alcohol availability and high-risk sexual behavior at the neighborhood level.

STUDY DESIGN

Ecological analysis of the geographic relation between off-premise, on-premise, and total alcohol outlet density and reported gonorrhea rates among 155 urban residential census tracts in New Orleans during 1995.

RESULTS

All alcohol outlet density variables were positively related to gonorrhea rates. Off-premise outlets per square mile was most strongly related to gonorrhea rates (beta +/- SE) (beta = 0.582+/-0.073), accounting for 29% of the variance in gonorrhea rates. Interpreted as an elasticity, a 10% increase in off-sale alcohol outlet density accounts for a 5.8% increase in gonorrhea rates. Including the covariates percent black and percent unemployed to the model reduced but did not remove the effect of off-sale outlet density (beta = 0.192+/-0.047).

CONCLUSIONS

These results indicate there is a geographic relationship between alcohol outlet density and gonorrhea rates at the census tract level. Although these results cannot be interpreted causally, they do justify a public health intervention as a next step in defining the relation between alcohol availability and high-risk sexual behavior.

Attitudes and compliance of pre-adolescent children during early treatment of Class II malocclusion

A survey was administered to 168 parents and their children at the end of mixed dentition treatment for Class II correction utilizing bionators and headgears to investigate attitudes of parents and patients toward bionators and headgears and to elicit factors associated with compliance. Directional differences between parent and child responses occurred frequently with agreement ranging from 41 to 100%, averaging 69% overall. The results indicate that the orthodontic patient population has medical and dental health as a priority. While parental and child reasons for seeking treatment may be different, it appears that both groups seek care for perceived benefits of health, decreased present and future oral problems, peer influences, and dental self image improvement. Additionally, children who are undergoing treatment perceive that others do not understand what they are going through, they may be embarrassed, and some may break their appliances to annoy the parent or orthodontist. Pain, decreased ability to speak, and difficulty chewing were reported to decrease appliance wear. Patient understanding of the treatment goals was reported to increase compliance. The bionator caused more instances of speech problems and associated non-compliance than the headgear. The headgear caused more instances of pain, but did not cause significantly less associated compliance than the bionator. The results suggest that bolstering the patient-orthodontist relationship, informing the patient about the treatment goals, methods, and their individual role, and offering immediate short term rewards can potentially increase patient compliance.

Idiopathic pneumonia syndrome in mice after allogeneic bone marrow transplantation

Pulmonary complications are a major clinical problem following allogeneic bone marrow transplantation (BMT), contributing to more than 30% of transplant-related mortalities. Idiopathic pneumonia syndrome is responsible for significant mortality among BMT patients. However, the etiology of injury to the lung parenchyma by this disease syndrome is unknown and it has been difficult to evaluate the cellular and molecular mechanisms underlying IPS in the absence of a suitable animal model. To study post-BMT lung disease during graft-versus-host disease (GVHD), we have developed a murine model that utilizes a semi-allogeneic parental --> F1 transplant strategy to induce a mild form of GVHD. Progressive inflammatory lung disease developed in animals with mild GVHD, as indicated by changes in immune cell distribution and cytokine expression in the lungs of transplanted animals. Histologic analysis of lung tissue from GVHD mice at 3 wk post-BMT showed minor immunopathologic changes compared with control mice. In contrast, lungs of GVHD mice at 12 wk displayed histopathologic hallmarks of interstitial pneumonitis, such as prominent perilumenal mononuclear cell infiltration and areas of alveolar congestion. Flow cytometric analysis of lung interstitial cells of GVHD mice revealed an increase in CD8+ T-cells at week 3, which decreased to normal levels by week 12 post-BMT. Simultaneously, the percentage of CD4+ T-cells increased progressively above normal levels and peaked at week 7 post-BMT. Analysis of cytokine mRNA expression in lung tissue indicated that steady state levels of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, interferon-gamma, and IL-12 were significantly elevated in lungs of GVHD mice at 3 wk post-BMT compared with untreated controls. Mice that were transplanted with allogeneic bone marrow alone (BMT controls) also displayed elevated expression of these cytokines, although only IL-6 was significantly higher than in untreated controls. In contrast, at 12 wk after transplantation only TNF-alpha and IL-12 levels remained elevated in GVHD mice, suggesting prolonged macrophage activation. On the basis of these findings, we conclude that allogeneic bone marrow transplantation in this mouse model causes a progressive interstitial pneumonitis, which is characterized by an acute influx of CD8+ T-cells, followed in the chronic phase by a prominent accumulation of CD4+ T-cells, and is associated with persistent production of cytokines known to activate macrophages.

A school-based Chlamydia control program using DNA amplification technology

OBJECTIVES

Chlamydia trachomatis is the most prevalent bacterial sexually transmitted disease (STD) in the United States, with the highest rates reported among adolescents. Chlamydia has severe consequences including pelvic inflammatory disease and infertility, and is believed to be a cofactor in human immunodeficiency virus transmission. Given that chlamydia is predominantly asymptomatic, most cases are identified through routine screening in health care settings. Over time, screening and treatment appear to be associated with a decrease in the prevalence of disease in areas with consistent chlamydia control programs. The new availability of sensitive and specific urine tests for chlamydia (polymerase chain reaction [PCR] and ligase chain reaction [LCR]) provides the opportunity to screen large numbers of at-risk youth in a noninvasive manner. We used PCR/LCR testing to investigate the feasibility of a school-based chlamydia control program and to determine the prevalence of chlamydia infection among junior and senior high school students.

DESIGN

At three junior/senior high schools, all students, regardless of symptoms or sexual history, were given the opportunity to be tested for chlamydia using urine-based PCR or LCR testing. Only students with parental consent were eligible. Parents could not obtain test results, except if their children told them. During the five 3-week testing periods, throughout the day, classes were escorted to the testing area and each student was individually counseled regarding the opportunity to participate in the testing.

SETTING

Three urban public schools in Louisiana.

PARTICIPANTS

A total of 1933 students in grades 7 through 12, including 861 girls and 1072 boys.

INTERVENTION

All students were informed about the test and taught about chlamydia during the homeroom period. Students were asked to provide a first-void urine specimen of not more than 30 mL. Specimens were refrigerated and delivered to the laboratory on the same day. Infected students were counseled and offered treatment with azithromycin, 1 g orally. They were also referred for or offered additional STD and human immunodeficiency virus testing. Infected students were asked to refer their sex partners to the city STD clinic for treatment.

MAIN OUTCOME MEASURE

Prevalence of C trachomatis infection by grade and gender.

RESULTS

Parental consent was obtained for 2849 (86.9%) of the 3278 matriculated students in grades 7 through 12. Fifty-one parents (1.6%) returned consent forms refusing permission for their child to participate in this screening and treatment program. The remaining 378 (11.5%) could not be reached by mail or telephone. Among all students with consent, 1933 (67.8% of those consented and 59.0% of those matriculated) were tested. Girls were less likely to be tested than boys (861/1363 [63. 2%] vs 1072/1465 [73.2%]). The overall prevalence of C trachomatis was 6.5%, with rates among girls more than twice that of boys (9.7% vs 4.0%). Generally, rates of infection increased with age. The prevalence rates among boys were for 7th grade, 2/208 (1%); 8th grade, 2/196 (2%); 9th grade, 10/236 (4.2%); 10th grade, 12/185 (6. 5%); 11th grade, 8/146 (5.5%); and 12th grade, 9/101 (8.9%). For boys 15 to 19 year old, the prevalence of chlamydia was 5.7%. Among girls, the prevalence rates were 7th grade, 0/105 (0%); 8th grade, 11/166 (6.6%); 9th grade, 23/218 (10.6%); 10th grade 23/146 (15.8%); 11th grade, 13/118 (11%); and 12th grade, 13/107 (12.1%). Among girls 15 to 19 years old, 12.7% were infected. Of 126 infected students, treatment was provided to 111 (88%). For this project, the laboratory cost of LCR testing was $17.76 per test. Without considering clinical staff time to collect the specimens, the average laboratory cost per infected student identified was $272. For students 15 to 19 years of age, of whom 104 (8.9%) of 1170 were infected, the laboratory cost was $200 per case identified.

CONCLUSION

(ABSTRACT TRUNCATED)

Anteroposterior skeletal and dental changes after early Class II treatment with bionators and headgear

In this study we examined anteroposterior cephalometric changes in children enrolled in a randomized controlled trial of early treatment for Class II malocclusion. Children, aged 9.6 +/- 0.8 years at the start of study, were randomly assigned to control (n = 81), bionator (n = 78), and headgear/biteplane (n = 90) treatments. Cephalograms were obtained initially, after Class I molars were obtained or 2 years had elapsed, after an additional 6 months during which treated subjects were randomized to retention or no retention and after a final 6 months without appliances. Calibrated examiners, blinded to group, used Johnston's analysis to measure anteroposterior cephalometric changes. Statistical analysis was used to determine annual skeletal and dental changes during treatment, retention, and follow-up, and overall. Our data reveal that both bionator and head-gear treatments corrected Class II molar relationships, reduced overjets and apical base discrepancies, and caused posterior maxillary tooth movement. The skeletal changes, largely attributable to enhanced mandibular growth in both headgear and bionator subjects, were stable a year after the end of treatment, but dental movements relapsed.

Enhanced cytokine detection by a novel cell culture-based ELISA

Production of some cytokines, such as IL-4 and IL-10, often occurs at low levels and is difficult to detect by standard ELISA techniques. In many cases the level of detection is at or near to the limits of sensitivity of the assay due either to minimal synthesis and/or cytokine consumption. In an effort to enhance the quantitation of weakly detected cytokines we have developed a unique cell culture-capture ELISA. Lymphocytes are incubated in an anti-cytokine antibody coated ELISA plate for the last 6 hours of a 24 hour in vitro activation period. Use of this cell culture capture method consistently enhanced detection of several T cell cytokines compared to conventional ELISA techniques. Moreover, this technique was found to enhance detection without altering the rate of cytokine secretion which occurred prior to the cell culture capture period. Thus, the cell culture capture ELISA may be useful for detection of a variety of cytokines which are produced at low levels and have traditionally been difficult to quantify.

Zinc attenuates tumor necrosis factor-mediated activation of transcription factors in endothelial cells

OBJECTIVE

The objective of the study was to test the hypothesis that zinc can protect against endothelial dysfunction by interfering with oxidative stress-mediated cellular signaling and subsequent inhibition of an endothelial cell inflammatory response. Our approach was to compare alterations on molecular and biochemical levels with changes in endothelial barrier function that occur in zinc deficient conditions.

METHODS

To investigate our hypothesis, endothelial cells were exposed to zinc deficient media for 2 to 10 days to deplete cellular zinc stores. Following this, half of the groups received zinc supplementation (9.2 microM) for 48 hours. The other half served as zinc deficient controls. These cells were then challenged with tumor necrosis factor-alpha (TNF) for varying time periods. Nuclear extracts were prepared from cells and analyzed for nuclear factor kappa B (NF-kappa B) and activator protein-1 (AP-1) binding. Media from cells were analyzed for interleukin 8 (IL-8) production, and cellular proteins were determined.

RESULTS

Zinc supplementation resulted in a 74% increase in cellular zinc content. It was also shown that a 1.5 hour exposure to TNF (100 U/mL medium) significantly increased NF-kappa B and AP-1 binding, which was lowered considerably when cells were supplemented with physiological levels of zinc. Zinc supplementation also caused a marked attenuation in IL-8 expression by endothelial cells in response to TNF-mediated cell activation.

DISCUSSION

Our previous data clearly show that zinc is a protective and critical nutrient for maintenance of endothelial integrity. The present data suggest that zinc may protect against cytokine-mediated activation of oxidative stress sensitive transcription factors, upregulation of inflammatory cytokines and endothelial cell dysfunction. This may have implications in understanding mechanisms of atherosclerosis.

Metabolically inactive insulin analog prevents type I diabetes in prediabetic NOD mice

The purpose of this study was to determine the relative importance of the metabolic effects of insulin for diabetes prevention by administering insulin or an inactive insulin analog by daily subcutaneous injections to prediabetic mice. A recombinant monomeric human insulin analog, which does not bind to the insulin receptor as a consequence of an alteration of a single amino acid at position 25 of the B chain, was shown to be equally effective at diabetes prevention as was intact insulin. In contrast to native insulin, the insulin analog did not cause hypoglycemia after subcutaneous injection. The insulin analog, however, protected young adult mice from diabetes, even when it was initiated after the onset of extensive lymphocytic infiltration of the islets. Thus, preventative therapy by daily subcutaneous injections of insulin does not require the hypoglycemic response, or binding to the insulin receptor to prevent the onset of type I diabetes.

Rapid screening and treatment for sexually transmitted diseases in arrestees: a feasible control measure

OBJECTIVES

The purpose of this study was to determine the feasibility and usefulness of rapid screening and immediate presumptive treatment for sexually transmitted diseases among arrestees at a county jail.

METHODS

The rapid plasma reagin test (for syphilis) and the urine leukocyte esterase test (for urethritis) were used in establishing routine screening and presumptive treatment for sexually transmitted diseases among arrestees.

RESULTS

Of 4757 arrestees screened, 82 (1.7%) had untreated syphilis, and, of 4174 male arrestees screened, 541 (13%) had a positive leukocyte esterase test. The syphilis prevalence rate was higher among women than among men (3.1% vs 1.5%), and the rate was higher among Blacks than among Whites (2.3% vs 0.7%). Although leukocyte esterase test positivity was higher among persons reporting a urethral discharge (57% vs 12%), 88% of persons with a positive test result did not report such symptoms.

CONCLUSIONS

The program described here has reached persons with sexually transmitted diseases who are unlikely to use traditional health care services and thus are likely to remain untreated. Rapid screening and treatment for sexually transmitted diseases among arrestees is feasible and should be considered in areas with high sexually transmitted disease rates.

Role of T-lymphocytes in the resolution of endotoxin-induced lung injury

An acute neutrophilic lung injury was compared in Balb/c normal and nu/nu (nude) mice to assess the role of T lymphocytes in the resolution of acute pulmonary neutrophilic inflammation following the administration of endotoxin. Maximal neutrophilic infiltration occurred on day 1 post-endotoxin treatment and declined to near normal levels by day 5. In contrast, the percentage of lymphocytes in the bronchoalveolar lavage (BAL) fluid increased from 1.8% on day 1 post-endotoxin to greater than 11% on days three and five, during which time neutrophil resolution was occurring. On days 1-5 after endotoxin administration, approximately 40% of the CD4 lymphocytes expressed the cell surface activation marker, CD69. Despite being CD69+, CD4 cells did not express the high affinity IL-2 receptor chain, CD25, to any significant extent on any of the days studied. To assess the contribution of T cells to the rate of clearance of neutrophils from the BAL, normal and nude Balb/c mice were compared for the percentage of neutrophils following nasal administration of endotoxin. Endotoxin-treated nude mice did not demonstrate significant differences in either the total white blood cell counts or in the clearance of neutrophils from the BAL, as compared to normal Balb/c mice. These data indicate that the influx of activated T cells during the resolution of neutrophilic pneumonitis does not contribute to the rate of neutrophil clearance during acute lung injury.

Pulmonary mechanical and immunologic dysfunction in a murine model of AIDS

Human immunodeficiency virus-infected patients occasionally exhibit alveolar septal wall thickening and decreases in gas diffusion capacity, but the mechanism underlying these abnormalities is unknown. The present study evaluated septal wall thickness and gas exchange properties in a murine model of the acquired immunodeficiency syndrome and determined whether there were alterations in lung lymphocyte deposition and activation that could contribute to changes in respiratory structure and function. Although alveolar septal wall thickness did not differ from control at 1, 2, and 4 wk postimmunosuppressive virus infection, at 8 wk after infection, septal wall thickness was substantially increased. Immunohistochemical evaluation at this time revealed marked increases in the septal wall deposition of fibronectin and collagen type IV. Pulmonary function tests on anesthetized mice with virus-induced septal wall thickening demonstrated that, although total lung capacity, compliance, and functional residual capacity were unaltered, diffusion capacity for carbon monoxide was significantly impaired. A diffuse nonspecific interstitial pneumonitis was present in lungs of immunodeficient mice, and flow cytometry indicated that both lymphocytes and macrophages were activated. Reverse transcriptase-polymerase chain reaction analysis of lung lymphocytes demonstrated enhanced mRNA expression for several cytokines known to affect lung structure. These results show that impaired gas exchange occurs in a murine model of acquired immunodeficiency syndrome and suggest that such alterations may be mediated by elaboration of cytokines from activated lung lymphocytes and macrophages.

Pulmonary lymphoid cell activation and cytokine expression in murine AIDS-associated interstitial pneumonitis

Limited information is available about the pathogenesis of acquired immune deficiency syndrome (AIDS)-associated idiopathic interstitial pneumonitis, a common noninfectious complication of human immunodeficiency virus (HIV) infection. Infection of C57B1/6 mice with LP-BM5 retrovirus, a murine model of AIDS, leads to development of a diffuse interstitial pneumonitis that displays many features of human AIDS-associated interstitial pneumonitis. To further characterize the cellular and molecular features of this lung disease, the temporal development of cellular infiltration, cytokine expression, and virus replication were evaluated in lung tissue of virus-infected mice. Persistent expression of viral RNA was detectable in lungs as early as 1 wk after infection. Infiltration of the lungs by CD4+ and CD8+ T cells, by IgG+ and IgA+ B cells, and by macrophages was observed by 4 wk after infection and continued through 8 wk of infection. Histologically, cellular infiltration was most pronounced in peribronchial and perivascular regions, whereas inflammation of alveolar septae and alveolar spaces was minimal. In contrast to normals, T cells from infected lungs were immunodeficient in that they failed to proliferate in response to the mitogen concanavalin A (ConA). However, evaluation of cytokine mRNA expression by interstitial lung lymphoid cells indicated that cells from infected lungs were chronically activated, in that elevated expression of interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) was observed throughout the course of infection. Similarly, expression by interstitial lung lymphoid cells of mRNA for the proinflammatory cytokine IL-1 and the fibrogenic cytokine transforming growth factor-beta (TGF-beta) was also increased following infection. These results indicate that retrovirus-induced immunodeficiency in mice is associated with infiltration and chronic activation of lymphoid cells in the lungs. Furthermore, simultaneous expression of IL-10, IFN-gamma, and TGF-beta suggests that cytokine-expressing cells in infected lungs may be unresponsive to inhibitory and antiinflammatory effects of IL-10 and/or TGF-beta, thus contributing to chronicity of inflammation in this disorder.

Parenting styles, adolescent substance use, and academic achievement

This article investigates how children and their parents rate their parenting styles, and how this rating is associated with academic achievement, alcohol, and tobacco use. We surveyed students and their parents in two public school districts. A total of 386 matched parent-child pairs from eighth- and ninth-grade students were analyzed for parent and student classification of parents as authoritative, authoritarian, permissive, or mixed parenting styles. Agreement on parenting styles between parents and children was poor. Students perceived parents as less authoritative, less permissive and more authoritarian than parents considered themselves. High grades were associated with child and parent perception of higher authoritativeness, lower permissiveness, and lower authoritarianism. Child tobacco and alcohol use was associated with child perception of lower authoritativeness, and higher permissiveness while parent perception of parenting style was not associated with child substance use. This study provides further evidence that parenting styles and adolescents' perceptions of them are associated with child achievement and substance use. While we cannot determine whether child or parent perception of parenting style is more accurate, child perception is more strongly associated with grades and substance use than is parent perception. It is likely that parents would benefit from understanding how they are perceived by their children.

Defective CD4+ T cell signaling in murine AIDS: uncoupling of the T cell receptor complex from PIP2 hydrolysis

CD4+ T cells from mice with murine AIDS (MAIDS) have been shown to be unable to respond to TCR stimulation as measured by proliferation, IL-2 production, or IL-2R upregulation, although responsiveness was restored with PMA and ionomycin. In this report we have demonstrated that the inability of MAIDS CD4+ T cells to respond to CD3 stimulation was not associated with reduced surface expression of CD3, CD4, or CD28 and could not be overcome by costimulation with anti-CD28 antibody. However, MAIDS CD4+ T cells failed to activate the PIP2 hydrolysis pathway efficiently, resulting in diminished IP3 production and reduced Ca2+ mobilization compared to normal controls. Additionally, TCR signaling in MAIDS resulted in a reduction in the level of tyrosine phosphorylation of some proteins including deficient tyrosine phosphorylation of PLC-gamma 1, compared to normal CD4+ T cells. These studies suggest that stimulation through the TCR in CD4+ T cells from MAIDS-infected mice is uncoupled from the phosphotidylinositol hydrolysis pathway due to deficient activation of PLC-gamma 1.