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.

Liver antioxidant defenses in mice fed ethanol and the AIN-76A diet

The effects of chronic alcohol (EtOH) ingestion on antioxidant defenses in mice fed AIN-76A liquid diets were investigated. C57Bl/6 female mice were divided into three groups and fed the AIN-76A liquid EtOH diet containing EtOH to provide 31% of total caloric intake (TCI), the same basic diet containing EtOH to provide 35% of TCI, or an isocaloric AIN-76A liquid control diet. After 3 weeks, the mice were killed and livers were excised for biochemical analysis. Liver reduced glutathione (GSH) levels, and activities of both Mn-superoxide dismutase (SOD) and Cu/Zn-SOD were significantly decreased by both levels of EtOH. Activities of catalase and glutathione transferase (GT) were significantly increased, whereas glutathione peroxidase (GP) activity was not affected by either level of EtOH. Our previous study using the Lieber-DeCarli liquid EtOH diet caused a decline of total SOD and GP activities. The results suggest that chronic EtOH administration decreases liver antioxidant defenses; however, the mice fed the AIN-76A EtOH liquid diet can maintain a higher antioxidant defense capability than those fed Lieber-DeCarli EtOH liquid diet.

Ethanol as a possible cofactor in the development of murine AIDS

Chronic ethanol (EtOH) abuse in humans leads to a variety of immunomodulatory events that can alter resistance to a number of infectious agents. Whether alcohol abuse affects the susceptibility to human immunodeficiency virus infection or the subsequent development of acquired immune deficiency syndrome (AIDS) is a matter of extreme importance; however, available information in humans or animal models is limited. The goal of this study was to evaluate the effect of chronic EtOH feeding in mice on the development of immunodeficiency in the murine model of AIDS (MAIDS). C57BI/6 mice were placed on the Lieber-DeCarli liquid EtOH diet (25% or 31% total caloric intake) or a nutrient-matched isocaloric liquid control diet. Seven days later, mice were infected with the LP-BM5 murine leukemia virus mixture, and groups of infected and noninfected mice were assayed at defined time points postinfection for antigen-specific and nonspecific immune responses. In the absence of retroviral infection, chronic EtOH feeding (5-8 weeks) led to reductions in spleen weights, compared with isocaloric controls. In spite of reduced spleen size, mitogenic responses of spleen cells to concanavalin A (ConA) and lipopolysaccharide (LPS) were elevated in EtOH-fed mice, as compared with mice fed the control diet. Chronic EtOH feeding also enhanced the allogeneic mixed lymphocyte response and increased antigen-specific priming of both B-cells and CD4+ T-cells to the antigen, sheep red blood cells. In MAIDS-infected mice, chronic EtOH feeding delayed but did not prevent the onset of virus-induced immunodeficiency and MAIDS-induced autoantibody synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro tumor necrosis factor cytotoxicity in Hep G2 liver cells

Tumor necrosis factor-alpha (TNF-alpha) is a mediator of liver injury. The objective of this study was to develop an in vitro model of TNF-mediated liver cell injury using the Hep G2 cell line. Hep G2 cells normally are insensitive to TNF cytotoxicity, but they were rendered susceptible, or sensitized, to TNF cytotoxicity by inhibitors of RNA and protein synthesis. The concentration of TNF required to kill 50% of Hep G2 cells sensitized with 0.8 mumol/L actinomycin D (Act D) was 35 pmol/L compared with 5 pmol/L for LM fibroblasts, a classic target cell used in TNF cytotoxicity bioassays. Similarly, TNF cytotoxicity occurred in Hep G2 cells sensitized with cycloheximide (CHX), and cytotoxicity to both inhibitors was dose dependent. Both protein and RNA synthesis were inhibited in Hep G2 cells by the concentrations of CHX and Act D associated with TNF cytotoxicity. Hep G2 cells pretreated with TNF alone and later exposed to normally toxic concentrations of TNF with DACT did not develop cytotoxicity. Thus, in vitro tolerance to TNF was induced. Cytotoxicity also was more severe at modestly increased temperatures (39 degrees C versus 37 degrees C), which may have clinical relevance to hepatic decompensation during febrile episodes. We suggest that the Hep G2 cell line sensitized by inhibiting RNA and protein synthesis is a useful in vitro model for evaluating mechanism(s) of TNF-mediated liver cell injury.

Halachic perspective on involuntary psychiatric care of the mentally ill

According to most mental health statutes in force around the world, doctors may involuntarily treat only acutely psychotic patients who present some danger to themselves, others or property. Chronic patients who, owing to volitional or cognitive defects, present a similar danger may not be thus treated. This may cause situations to arise where dangerous chronically ill patients who refuse treatment may cause serious harm because of physicians' inability to treat them. This article suggests changes to contemporary mental health statutes, in line with Judaic Halachic codes, which view all mentally ill patients as potentially harmful, and require physicians to treat--voluntarily or involuntarily--all mentally ill persons.

Parent participation in an adolescent drug abuse prevention program

This study reports the level of participation of parents in a parent-targeted school-based drug prevention program, the differences between students whose parents participate and those who don't, and the implications for involving parents in future drug prevention programs. Among 1761 eligible seventh grade families, 1263 students (72%) and 1142 parents (65%) completed surveys assessing the quality of parent-child relationships as well as tobacco and alcohol use. Ten percent of eligible families attended at least one of the evening sessions. Compared to students whose parents completed the survey, students whose parents did not complete a survey were more likely to report they used tobacco, had more friends who used substances, were monitored less by their parents, had more risk-taking behaviors, had lower grade-point averages, and their parents had higher rates of tobacco and alcohol use. Parents who attended evening sessions had the lowest rates of tobacco use and reported spending the most time with their children. Parent-targeted drug preventions programs may stigmatize attending parents and may be unlikely to attract the highest risk families.

Regulation of B cell:T cell interactions: potential involvement of an endogenous B cell sialidase

In light of the ability of B cells treated with neuraminidase to interact more effectively with T cells, the increased capacity of activated, but not small resting B cells, to interact with T cells could be associated with the level of sialylation on certain B cell surface molecules which influences the effectiveness of the physical interaction between B and T cells. The purpose of this study was to determine if activation of B cells altered sialylation via an endogenous sialidase which affected both the initial interaction between T and B cells and subsequent B cell-induced T cell proliferation. The competitive neuraminidase inhibitor, 2-deoxy-2,3-dehydro-N-acetylneuraminic acid (NeuAc2en), inhibited LPS-mediated enhancement of B cell conjugate formation with Ia-specific T cell clones as well as enhancement of their capacity to stimulate a mixed lymphocyte reaction. The addition of NeuAc2en during LPS stimulation did not affect the surface expression of Ia, LFA-1, ICAM-1 or mB7, suggesting that inhibition of LPS-mediated enhancement by the sialidase inhibitor was not due to changes in the level of expression of the major B cell adhesion or co-stimulatory molecules. Short term stimulation with phorbol myristate acetate (PMA) and ionomycin also enhanced the ability of resting B cells to form antigen specific T:B conjugates. However, activation of B cells with PMA and ionomycin or with LPS did not change the capacity of a sialic acid specific lectin to bind to the B cells, suggesting that activation was not associated with global changes in surface sialic acid content. B cell stimulation did not appear to increase the activity of the most prevalent B cell sialidase activity as measured in an in vitro assay system, suggesting that the major B cell sialidase may not be responsible for the alteration of B cell sialylation levels or the ability of activated B cells to interact more effectively with T cells. The possibility of intracellular compartmentalization of sialidase activity or that a minor B cell sialidase may play a role in the regulation of a B cells ability to interact with T cells are discussed.

Parenting behaviors and the onset of smoking and alcohol use: a longitudinal study

OBJECTIVE

To identify which specific parenting behaviors are associated with the onset of alcohol and tobacco use and how they are associated.

DESIGN

Prospective cohort study of two groups of preadolescents surveyed annually, the first group for 4 years, the second for 3 years.

SETTING

Two public school districts in Southern California.

SUBJECTS

1034 fifth graders and 1266 seventh graders began the study after obtaining parental consent to complete surveys in a classroom setting. By the last measurement, attrition was 37 and 38% for the two cohorts, respectively.

MAIN OUTCOME MEASURES

The onset of tobacco or alcohol use in the last month.

RESULTS

Children who reported that parents spent more time with them and communicated with them more frequently had lower onset rates of using alcohol and tobacco in the last month. These parental interactions lead to more positive relationships with their children. Parental monitoring and positive relations were protective factors for disruptive behavior and the selection of substance-using friends. Disruptive behavior increased the odds of adolescents drinking in the last month approximately twofold and of smoking in the last month two to fourfold.

CONCLUSIONS

This study provides further evidence that parenting behaviors are significant precursors to adolescent disruptive behavior, vulnerability to peer pressure, and subsequent substance use. Parents should be targeted in future substance use prevention programs, before their children reach adolescence.

Pulmonary hypertension in a murine model of the acquired immunodeficiency syndrome

Rapidly accumulating evidence suggests that a proportion of patients with acquired immunodeficiency syndrome (AIDS) develop hypertensive pulmonary vascular disease reminiscent of primary pulmonary hypertension. As an initial step to explore the link between AIDS and hypertensive pulmonary vascular disease, the present study determined whether pulmonary hypertension is present in a well-characterized murine model of retrovirus-induced immunodeficiency. In agreement with previous reports, mice infected with the LP-BM5 murine leukemia virus developed polyclonal B and T cell activation followed by progressive and severe B and T cell immunodeficiency. At 12 wk postinfection, when persistent immunodeficiency was established, mice were anesthetized, and right ventricular systolic pressure was determined in open-chest, mechanically ventilated animals. Mean right ventricular systolic pressure was 14.7 +/- 1.3 mm Hg in control animals and was increased significantly to 22.5 +/- 3.2 mm Hg in virus-infected mice. Right ventricular hypertrophy was also present in infected mice as evidenced by a 27% increase in the ratio of right to left ventricular weights; there were no group-dependent differences in the left ventricular to total-body weight ratio. Morphometric evaluation indicated that medial thickness in muscularized pulmonary arteries, expressed as a percentage of the external diameter, was 9.6 +/- 0.4% in control lungs and increased to 14.4 +/- 0.5% in lungs from infected animals. Qualitative histopathologic analysis suggested increased perivascular collagen deposition in lungs from infected animals relative to control animals. Unlike AIDS patients with pulmonary hypertension, infected mice did not exhibit plexiform lesions or intimal fibrosis of the pulmonary arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism of differential regulation of IL-2 in murine Th1 and Th2 T cell subsets. 1. Induction of IL-2 transcription in Th2 cells by up-regulation of transcription factors with the protein synthesis initiation factor 4E

Regulation of IL-2 gene expression in response to receptor-mediated stimuli is known to be mediated primarily by the IL-2 transcriptional enhancer and multiple transcription factors. However, the mechanism that controls the differential expression of the IL-2 gene in both human and murine CD4+ Th cell subsets (Th1-IL-2+ and Th2-IL-2-) is not clearly understood. Differential IL-2 gene expression was assessed in murine Th1 and Th2 subsets by analyzing the expression of a Escherichia coli lacZ reporter gene under control of the human IL-2 enhancer (IL2ZH) transfected in both T cell subsets. Stimulation of transfected T cells with the mitogen Con A, anti-CD3 Ab, or PMA plus ionomycin activated the IL2ZH construct in Th1 but not Th2 cells. However, IL2ZH was activated in stimulated Th2 cells that were co-transfected with a vector that overexpressed the eukaryotic initiation factor 4E (eIF-4E). It has been shown that eIF-4E is rate limiting for protein synthesis and its overexpression leads to increased rates of protein synthesis. Hence, eIF-4E overexpression could have overcome a deficiency in transcriptionally active levels of IL-2 regulatory factors in Th2 cells leading to IL-2 enhancer activation. This possibility was supported by demonstrating that transcriptionally active levels of the critical IL-2 transcription factor, nuclear factor of activated T cells (NF-AT), occurred only in Th2 cells overexpressing eIF-4E but not in normal Th2 cells, thus indicating that the inability of Th2 cells to express IL-2 was associated with inadequate levels of at least one transcription factor, NF-AT. Moreover, these results were confirmed by the observation that eIF-4E overexpression augmented NF-AT binding activity in Th2 cells. These data suggest that concentrations of inducible transcription factors are a major component of the regulatory mechanisms dictating IL-2 expression and may be under translational control in Th1/Th2 T cell subsets.

Mechanism of differential regulation of IL-2 in murine Th1 and Th2 T cell subsets. 1. Induction of IL-2 transcription in Th2 cells by up-regulation of transcription factors with the protein synthesis initiation factor 4E

Regulation of IL-2 gene expression in response to receptor-mediated stimuli is known to be mediated primarily by the IL-2 transcriptional enhancer and multiple transcription factors. However, the mechanism that controls the differential expression of the IL-2 gene in both human and murine CD4+ Th cell subsets (Th1-IL-2+ and Th2-IL-2-) is not clearly understood. Differential IL-2 gene expression was assessed in murine Th1 and Th2 subsets by analyzing the expression of a Escherichia coli lacZ reporter gene under control of the human IL-2 enhancer (IL2ZH) transfected in both T cell subsets. Stimulation of transfected T cells with the mitogen Con A, anti-CD3 Ab, or PMA plus ionomycin activated the IL2ZH construct in Th1 but not Th2 cells. However, IL2ZH was activated in stimulated Th2 cells that were co-transfected with a vector that overexpressed the eukaryotic initiation factor 4E (eIF-4E). It has been shown that eIF-4E is rate limiting for protein synthesis and its overexpression leads to increased rates of protein synthesis. Hence, eIF-4E overexpression could have overcome a deficiency in transcriptionally active levels of IL-2 regulatory factors in Th2 cells leading to IL-2 enhancer activation. This possibility was supported by demonstrating that transcriptionally active levels of the critical IL-2 transcription factor, nuclear factor of activated T cells (NF-AT), occurred only in Th2 cells overexpressing eIF-4E but not in normal Th2 cells, thus indicating that the inability of Th2 cells to express IL-2 was associated with inadequate levels of at least one transcription factor, NF-AT. Moreover, these results were confirmed by the observation that eIF-4E overexpression augmented NF-AT binding activity in Th2 cells. These data suggest that concentrations of inducible transcription factors are a major component of the regulatory mechanisms dictating IL-2 expression and may be under translational control in Th1/Th2 T cell subsets.

Tactile activity in primate primary somatosensory cortex during active arm movements: correlation with receptive field properties

1. Five hundred ninety-five single neurons with tactile receptive fields (RFs) on the contralateral arm were isolated in the primary somatosensory cortex (SI) of awake, behaving monkeys. 2. Fifty-eight percent of the tactile cells showed significantly different levels of activity during active movements of the arm in eight directions or during active maintenance of the arm over the target endpoints. 3. The discharge of many of the active tactile cells was unimodally tuned with movement direction and the pattern of the tactile population activity varied in a meaningful fashion with arm movement direction and posture. 4. The intensity of the arm-movement-induced activity was typically less than that evoked by direct tactile stimulation of the cell's RF. 5. The probability of task-related activity was correlated with certain RF properties, in particular the sensitivity of the cell to lateral stretch of the skin and to passive arm movements that avoided direct contact of the RF on any surface. 6. This suggests that task-related activity results mainly from the activation of tactile receptors by mechanical deformation of the skin as the arm changes geometry during movement. 7. These results demonstrate that tactile activity containing potential proprioceptive information is generated in SI during active arm movements that avoid direct contact of the skin with external surfaces. Whether or not this input contributes to the kinesthetic sensations evoked by the movements cannot be resolved by this study.

Tactile activity in primate primary somatosensory cortex during active arm movements: cytoarchitectonic distribution

1. Cells were recorded in areas 3b and 1 of the primary somatosensory cortex (SI) of three monkeys during active arm movements. Successful reconstructions were made of 46 microelectrode penetrations, and 298 cells with tactile receptive fields (RFs) were located as to cytoarchitectonic area, lamina, or both. 2. Area 3b contained a greater proportion of cells with slowly adapting responses to tactile stimuli and fewer cells with deep modality inputs than did area 1. Area 3b also showed a greater level of movement-related modulation in tactile activity than area 1. Other cell properties were equally distributed in the two areas. 3. The distribution of cells with low-threshold tactile RFs that also responded to lateral stretch of the skin or to passive arm movements was skewed toward deeper laminae than for tactile cells that did not respond to those manipulations. 4. The variation of activity of tactile neurons during arm movements in different directions was weaker in the superficial laminae than in deeper cortical laminae. 5. Cells with only increases in activity during arm movements were preferentially but not exclusively located in middle and superficial layers. Cells with reciprocal responses were found mainly in laminae III and V, whereas cells with only decreases in activity were concentrated in lamina V. 6. Overall, active arm movements evoke directionally tuned tactile and "deep" activity in areas 3b and 1, in particular in the deeper cortical laminae that are the source of the descending output pathways from SI.

Activation-dependent apoptosis in CD4+ T cells during murine AIDS

The mechanism by which CD4+ T cells are depleted during HIV infection remains a matter of controversy. Recent reports have suggested that activation-induced apoptosis of antigen-specific CD4+ T cells may lead ultimately to depletion of this T cell subset during HIV infection. The murine retroviral model of AIDS (MAIDS) also displays progressive immunodeficiency, but depletion of the CD4+ T cell subset is not characteristic of the disease. We report that a fraction of splenic CD4+ T cells from 8- to 14-week MAIDS-infected C57B1/6 mice, but not normal mice, was undergoing apoptosis at the time of cell isolation. Typical apoptotic morphology and internucleosomal DNA fragmentation was seen in CD4+ T cells only from infected mice. Moreover, injection of anti-CD3 mAb enhanced DNA fragmentation in CD4+ T cells from infected but not normal mice, suggesting that the apoptosis in vivo in CD4+ T cells during MAIDS may be dependent on cell activation. Induction of apoptosis was associated with defective signaling through the TcR complex, since anti-CD3 stimulation in vitro of CD4+ T cells from infected mice caused a diminished calcium response, yet no cellular proliferation. Despite the occurrence of apoptosis in vivo in CD4+ T cells from MAIDS-infected mice, CD4+ T cells were not depleted during the course of disease. Thus, while apoptosis in CD4+ T cells is a characteristic of MAIDS immunodeficiency disease as well as HIV infections in humans, CD4+ T cell depletion is only observed in HIV infections. In view of the extensive lymphocyte expansion which occurs in vivo in MAIDS, the balance between activation-induced apoptosis and chronic cell proliferation may determine whether cell depletion is a characteristic feature of retrovirus-induced immunodeficiencies.

Effects of chronic alcohol feeding and murine AIDS virus infection on liver antioxidant defense systems in mice

Whether ethanol (ETOH) abuse could contribute to the development of acquired immunodeficiency syndrome (AIDS) among human immunodeficiency virus (HIV)-positive drug abusers is a critical question for which little experimental information is available. This study was designed to determine if chronic ETOH feeding and murine AIDS virus infection cooperatively affected liver antioxidant defense systems in C57B1/6 female mice. Mice were divided into two groups and fed the Lieber-DeCarli liquid ETOH diet containing ETOH at a concentration to provide 31% of total caloric intake or an isocaloric liquid control (control) diet in which dextrin-maltose replaced ETOH. One week after the initiation of ETOH feeding, half of the mice in each diet group (8 mice) were injected intraperitoneally with murine retrovirus (MAIDS) stock. After 3 and 5 weeks of ETOH feeding, half of the mice in each of the four treatment groups (4 mice) were killed, and livers were excised for biochemical analysis. Liver reduced glutathione (GSH) levels and activities of glutathione peroxidase (GP), glutathione reductase (GR), glutathione transferase (GT), catalase and superoxide dismutase (SOD), and serum ETOH concentrations were determined. The results demonstrated that serum ETOH concentrations were significantly elevated in ETOH-MAIDS group when compared with the ETOH group. Moreover, chronic ETOH feeding and MAIDS infection independently depressed liver antioxidant defense capability, and together led to an additive inhibition of GSH and SOD activities. In addition, MAIDS infection inhibited an ETOH-induced increase in catalase and GT activities. These results suggest that alcohol abuse could contribute to the development of AIDS by inhibiting the protective capability of an infected individual against oxidative stress.(ABSTRACT TRUNCATED AT 250 WORDS)

Controlling a syphilis epidemic

In 1986 the rate of infectious syphilis (primary and secondary) in Los Angeles County began to rise from previously stable levels of about 23.5 per 100,000 to peak at 55.6 per 100,000 in 1987. The incidence of congenital syphilis increased from 205 cases in 1987 to 575 cases in 1989. The county's Sexually Transmitted Disease Program instituted a disease-specific plan to address the epidemic. Factors considered in designing the program included the high morbidity and mortality associated with congenital infection, the existence of latent infection, self-limiting symptoms, and the availability of an inexpensive screening test and curative treatment. Policy changes implemented comprised expanded screening, expanded surveillance, increased contact tracing, and the initiation of condom promotion programs. To evaluate the relative effectiveness of Los Angeles County's syphilis control efforts, the epidemic curve for infectious syphilis was compared with trends in other urban areas. Although the rate of infectious syphilis climbed a year earlier in Los Angeles than in other cities, it returned to baseline levels when other cities' rates remained at epidemic levels.

Condoms for men, not women. Results of brief promotion programs

Three different brief intervention programs to promote condom use were tested among patients in inner-city sexually transmitted disease (STD) clinics. The first, "Condom Skills," focused on teaching mechanical aspects of how to use a condom. The second, "Social Influences," emphasized how to negotiate condom use with one's sexual partner. The third, "Distribution," provided patients with an unlimited number of free condoms, retrievable at local community businesses. Of the 903 subjects whose medical records were reviewed after exposure to the intervention programs, evidence of continued unsafe sexual behavior, documented by subsequent treatment for a new STD, was found for 12.6% of the women and 19.9% of the men. When compared with male control subjects, male study patients had fewer documented subsequent STD reinfections. The relative risk (RR) and 95% confidence interval (CI) values were 0.48 and 0.28, 0.81 for the condom skills group; 0.65 and 0.40, 1.04 for the social influences group; and 0.85 and 0.56, 1.29 for the distribution group. There was no decrease in the incidence of STDs among female patients compared with control subjects; indeed, there was a trend toward increased risk of STDs among women exposed to the Social Influences intervention program. This study demonstrates that brief condom promotion programs can be effective for male STD patients, and that caution must be exercised in promoting condoms to women with a high risk of acquiring STDs. Further research on programs promoting safer sex among these women is needed.

T-deficient transmembrane signaling in CD4+ T cells of retroviral-induced immune-deficient mice

The defective virus found in the LP-BM5 mixture of murine leukemia viruses induces a severe immune deficiency disease in C57BL/6 mice that is characterized by the activation and expansion of T and B cells that become unresponsive to normal immune stimuli. The nature of the biochemical lesion in these defective lymphocyte populations remains unknown. Flow cytometric analysis of the T cell population in infected animals has demonstrated expansion of both CD4+ and CD8+ subsets. Despite chronic expansion in vivo, CD4+ T cells by wk 4 postinfection failed to up-regulate cell surface IL-2R expression, produced IL-2, or proliferate in vitro in response to either Con A, Staphylococcal enterotoxin super-antigens, or anti-CD3 stimulation. Exogenous IL-2 did not restore the proliferative response and also failed to up-regulate IL-R expression on CD4+ T cells from infected mice, even though basal IL-2R expression was initially elevated compared to normals. In contrast, CD4+ T cells from infected mice could be induced to proliferate by stimulation with PMA and ionomycin resulting in IL-2R up-regulation, IL-2 production, and proliferation. Moreover, proliferation could also be induced by anti-CD3 plus PMA, although anti-CD3 plus ionomycin was without effect. These studies suggest that chronic expansion of CD4+ T cells in infected mice is probably not maintained by normal TCR signaling, which appears defective in these cells. In addition, the lesion in biochemical signaling appears to result in defective activation of protein kinase C, which can be overcome by direct activation with PMA.

T-deficient transmembrane signaling in CD4+ T cells of retroviral-induced immune-deficient mice

The defective virus found in the LP-BM5 mixture of murine leukemia viruses induces a severe immune deficiency disease in C57BL/6 mice that is characterized by the activation and expansion of T and B cells that become unresponsive to normal immune stimuli. The nature of the biochemical lesion in these defective lymphocyte populations remains unknown. Flow cytometric analysis of the T cell population in infected animals has demonstrated expansion of both CD4+ and CD8+ subsets. Despite chronic expansion in vivo, CD4+ T cells by wk 4 postinfection failed to up-regulate cell surface IL-2R expression, produced IL-2, or proliferate in vitro in response to either Con A, Staphylococcal enterotoxin super-antigens, or anti-CD3 stimulation. Exogenous IL-2 did not restore the proliferative response and also failed to up-regulate IL-R expression on CD4+ T cells from infected mice, even though basal IL-2R expression was initially elevated compared to normals. In contrast, CD4+ T cells from infected mice could be induced to proliferate by stimulation with PMA and ionomycin resulting in IL-2R up-regulation, IL-2 production, and proliferation. Moreover, proliferation could also be induced by anti-CD3 plus PMA, although anti-CD3 plus ionomycin was without effect. These studies suggest that chronic expansion of CD4+ T cells in infected mice is probably not maintained by normal TCR signaling, which appears defective in these cells. In addition, the lesion in biochemical signaling appears to result in defective activation of protein kinase C, which can be overcome by direct activation with PMA.

Group counseling at STD clinics to promote use of condoms

An intervention was developed to promote safer sex and condom use among patients seeking treatment for sexually transmitted disease (STD) at a public health STD clinic in Los Angeles, CA. The intervention consisted of a short group discussion on condom use, a presentation of a videotape portraying condom use as socially acceptable behavior, and a role-playing session concerning negotiating the use of a condom with one's sex partner. The study group was 551 persons who visited the clinic in 1988. Medical records of 426 (77 percent) were located and reviewed 7 to 9 months later. Among those, 220 had participated in the intervention and 206 were control subjects who had not participated in the intervention. The rates at which patients reacquired STD after treatment and after the intervention were compared between the intervention group and the control group. Men who participated in the intervention subsequently showed a lower rate of STD reinfection than those who did not. There was no evidence that the intervention reduced reinfection among women. The strongest predictor of reinfection was found to be a history of STD infection prior to the infection that was being treated at the time of the intervention. The results show that group interventions directed to STD patients can be effective in reducing STD reinfection among men.

The effect of the endophyte (Acremonium coenophialum) and associated toxin(s) of tall fescue on serum titer response to immunization and spleen cell flow cytometry analysis and response to mitogens

Experiments were conducted with rats and mice to evaluate the effect of the consumption of endophyte (Acremonium coenophialum) and associated toxin(s) infected tall fescue on humoral and cellular aspects of immune function. Treatment diets were: (1) rodent chow (RC) or (2) rodent chow mixed 1:1 (w/w) with endophyte infected (E+) or (3) non-infected (E-) tall fescue seed. Rats fed the E+ diet in experiment 1 (43 days) exhibited a lower (P less than 0.05) serum titer to sheep red blood cell (SRBC) immunization than those fed the E- diet (38.4 vs 131.3). The E+ rats also had lower (P less than 0.01) white cell counts than either RC or E- groups (5225 vs 8959 and 7491/mm3). Spleen cells from mice fed the E+ diet for 37 days exhibited a reduced (P less than 0.05) response to the mitogens Concanavalin A and lipopolysaccharide. Flow cytometric analysis revealed a significant (P less than 0.01) 42% increase in T suppressor cell numbers in spleens of mice fed the E+ vs RC diets.

Parietal area 5 neuronal activity encodes movement kinematics, not movement dynamics

A previous study reported that proximal-arm related area 5 neurons showed continuously-graded changes in activity during unloaded arm movements in different directions (Kalaska et al. 1983), which resembled the responses of primary motor cortex cells in several respects (Georgopoulos et al. 1982). We report here that loading the arm reveals an important difference between cell activity in the two areas. Loads were continuously applied to the arm in different directions. The loads produced large continuously-graded changes in muscle activity but did not alter the handpath or joint angle changes of the arm during the movements. The activity of most area 5 cells was only weakly affected by the loads, and the overall pattern of population activity was virtually unaltered under all load conditions. This indicates that area 5 activity encodes the invariant spatial parameters (kinematics) of the movements. In contrast, many motor cortex cells showed large changes in activity during loading, and so signal the changing forces, torques or muscle activity (movement dynamics; Kalaska et al. 1989).