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.

Liver endogenous antioxidant defenses in mice fed AIN-76A diet and infected with murine AIDS

The effects of murine AIDS infection on endogenous antioxidant defenses in mice fed the AIN-76A liquid diet were investigated. C57BL/6 female mice were divided into 2 groups: one group was injected interperitoneally with LP-BM5 murine retrovirus (MAIDS) stock, and the other group served as the non-infected control. Two weeks after the infection, the mice were killed and livers were excised for biochemical analysis of the antioxidant defenses. Liver reduced glutathione (GSH) levels and activities of both cytosolic superoxide dismutase (SOD) and mitochondrial SOD were significantly depressed by MAIDS infection. Activities of glutathione reductase (GR) selenium (Se)-dependent glutathione peroxidase (GPx), catalase and glutathione-S-transferase (GST) toward 1-chloro-2,4-dinitrobenzene (CDNB) were not affected by MAIDS infection. A previous study by this laboratory using the Lieber-DeCarli (L-D) all purpose liquid diet caused a decline in total SOD activity and GPx activity, but not GSH levels. The results suggest that MAIDS infection depresses liver antioxidant defenses; however, MAIDS infection of mice fed the AID-76A liquid diet depresses different liver antioxidant defense parameters when compared to those of the mice fed the L-D all purpose liquid diet.