Effects of alcohol and nicotine on cytotoxic functions of human lymphocytes

Nicotine mediated epithelial modulations: An in-vitro evidence

Introduction

Nicotine, the main ingredient in tobacco, acts as a key alkaloid of nearly all tobacco products and has been demonstrated to facilitate tumorigenesis and accelerate metastasis. Further traditional tobacco products have shown to give systemic oral effects such as vasoconstriction, inflammation, and delayed wound healing, however; none of the reports have confirmed the significant knowledge of oral sequel of the effect of nicotine on oral epithelial cells. So, the current study aimed to investigate the effect of nicotine on epithelial transformation to a malignant state.

Material & methods

Through in-vitro experiments, the effects of nicotine on epithelial cells obtained from nicotine never exposed buccal mucosa were analyzed using total count and viability test, proliferation assay, cell cycle distribution assay, and PI3K/MAPK dual pathway activation assay.

Result & conclusion

MTT assay demonstrated that the proliferation of epithelial cells takes place at a 150 mM concentration of nicotine. Further, we identified the significantly increased cell count and viability in nicotine-exposed cells. Further, cell cycle distribution assay results demonstrated that nicotine forced the epithelial cells to enter the first growth phase. The same influence of nicotine was observed on the PI3K/MAPK dual pathway activation assay where a greater number of nicotine exposed cells showed dual pathway activation. In conclusion, the current study determined the potential mechanism of action of nicotine on oral epithelial cell proliferation through activating the oncogenic pathway. This may help to develop novel therapeutic strategies for the prevention of malignant transformation from smokeless tobacco-caused oral cancer.

Cigarette smoking and risk of infection-related mortality: A cohort study

BACKGROUND

Cigarette smoking is a leading cause of death worldwide and is associated with various diseases. However, studies addressing its impact on infection-related deaths are limited. This study examined the relationship between smoking and infection-related mortality.

METHODS

A cohort of 583,034 South Korean adults who underwent annual or biennial health examinations were followed-up for infection-related deaths using national records. Cox proportional hazards regression assessed hazard ratios (HRs) and 95% confidence intervals (CIs) for infection-related mortality.

RESULTS

The median follow-up was 9.1 years (maximum 18 years), and 335 infection-related deaths were identified. Current smoking, but not former smoking, was positively associated with an increased risk of infection-related mortality. After adjusting for possible confounders, the multivariable-adjusted HRs ( 95% CIs) for infection-related mortality comparing former and current smokers with never smokers were 0.94 (0.68-1.30) and 1.45 (1.05-2.02), respectively; and those for infection-related mortality by number of pack-years comparing 10-19.9 and ≥20 pack-years to <10 pack-years were 1.26 (0.81-1.96) and 1.47 (1.03-2.09), respectively, while those comparing 10-19 and ≥20 cigarettes/day to <10 cigarettes/day were 1.35 (0.86-2.11) and 1.54 (1.13-2.11), respectively (p for trend <0.05). Individuals with ≥20 pack-years had a 2.06 times greater risk of infection-related mortality when changes in smoking status and confounders during follow-up were updated in the analysis as time-varying covariates.

CONCLUSION

Current smoking status, intensity and pack-years were associated with an increased risk of infection-related death, with the highest risk of infection-related mortality found consistently in individuals with ≥20 pack-years.

IMPLICATIONS

In this large-scale cohort study of relatively young and middle-aged South Korean adults, current smoking, smoking intensity, and pack-years were associated with an increased risk of death due to infections; in particular, a significantly increased risk of infection-related mortality was consistently found in individuals with ≥20 pack-years. When appropriate, infection-related mortality should be included in smoking-attributable mortality burdens, and effective smoking control measures should be considered to improve infection-related mortality.

Ethanol affects fibroblast behavior differentially at low and high doses: A comprehensive, dose-response evaluation

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Ethanol exhibits hormetic response in terms of cellular activity.

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1 % (v/v) ethanol concentration demarcates non-toxic and toxic range.

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Different types of mitochondrial impairment identified at high dose.

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Cellular toxicity is accompanied by an increase in cellular stiffness.

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Dose-dependent cellular stress response to toxicity is observed.

This study aims to develop a comprehensive understanding of effects of low and high doses of ethanol on cellular biochemistry and morphology. Here, fibroblast cells are exposed to ethanol of varied concentrations [0.005−10 % (v/v)] to investigate cellular activity, cytoskeletal organization, cellular stiffness, mitochondrial structure, and real-time behavior. Our results indicate a sharp difference in cellular behavior above and below 1 % ethanol concentration. A two-fold increase in MTT activity at low doses is observed, whereas at high doses it decreases. This increased activity at low doses does not involve cell proliferation changes or mitochondrial impairment, as seen at higher doses. Moreover, the study identifies different types of mitochondrial structure impairment at high doses. Morphologically, cells demonstrate a gradual change in cytoskeletal organization and an increase in cell stiffness with increase in doses. Cells exhibit adaptation to sub-toxic doses of ethanol, wherein recovery from ethanol-induced stress is a dose-dependent phenomenon. Cell survival at low doses and toxicity at higher doses are attributed to mild and strong oxidative stress, respectively. Overall, the study provides a comprehensive understanding of dose-dependent effects of ethanol, manifesting its biphasic or hormetic response, biochemically, at low doses and illustrating its toxicological effects at higher doses.

Respiratory health effects of residential individual and cumulative risk factors in children living in two cities of the Pearl River Delta Region, China

Background

Indoor environment is complex, with many factors potentially interacting with each other to affect health. However, previous studies have usually focused on effect of a single factor. Assessment of the combined effects of multiple factors can help with understanding the overall health risk.

Methods

A cross-sectional study was conducted among 2,306 school children in Guangzhou and Shenzhen. Questionnaire data on respiratory symptoms and diseases were collected along with sociodemographic and residential environmental information. A subset of children (N=987) were measured for their lung function. A random forest algorithm was applied to screen the top-ranked indoor environmental exposure variables and to form a composite index for cumulative risk of indoor pollution (CRIP). Logistic regressions were conducted to analyze the independent effect of single indoor environmental risk factors and the combined effect of CRIP on children’s respiratory health. Multiple linear regressions were used to examine the independent and combined effects of indoor environmental exposure on lung function.

Results

We found that home dampness and molds as well as environmental tobacco smoke (ETS) were significantly and independently associated with increased prevalence of children’s respiratory symptoms and diseases and with reduced lung function. A higher CRIP level was significantly associated with increased risk of cough with cold (OR =1.37, 95% CI: 1.05–1.79) and wheeze (OR =2.71, 95% CI: 1.16–6.34). A higher CRIP level was also associated with reduced lung function measured as FVC, FEV₁, PEF, FEF_25%, FEF_25–75% and VC.

Conclusions

In children living in the subtropical region of the Pearl River Delta, home dampness and the presence of mold as well as ETS were individual risk factors for children’s respiratory health. The composite CRIP index was associated with respiratory symptoms and lung function, suggesting the utility of this index for predicting the combined effects of multiple risk factors.

Association Between Alcohol Use Disorders and Outcomes of Patients Hospitalized With Community-Acquired Pneumonia

IMPORTANCE

Patients with alcohol use disorder (AUD) are at elevated risk of developing pneumonia, but few studies have assessed the outcomes of pneumonia in patients with AUD.

OBJECTIVES

To compare the causes, treatment, and outcomes of pneumonia in patients with and without AUD and to understand the associations of comorbid illnesses, alcohol withdrawal, and any residual effects due to alcohol itself with patient outcomes.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study was conducted of 137 496 patients 18 years or older with pneumonia who were admitted to 177 US hospitals participating in the Premier Healthcare Database from July 1, 2010, to June 30, 2015. Statistical analysis was conducted from October 27, 2017, to August 20, 2018.

EXPOSURE

Alcohol use disorders identified from International Classification of Diseases, Ninth Revision, Clinical Modification codes.

MAIN OUTCOMES AND MEASURES

Pneumonia cause, antibiotic treatment, inpatient mortality, clinical deterioration, length of stay, and cost. Associations of AUD with these variables were studied using generalized linear mixed models.

RESULTS

Of 137 496 patients with community-acquired pneumonia (70 358 women and 67 138 men; mean [SD] age, 69.5 [16.2] years), 3.5% had an AUD. Patients with an AUD were younger than those without an AUD (median age, 58.0 vs 73.0 years; P < .001), more often male (77.3% vs 47.8%; P < .001), and more often had principal diagnoses of aspiration pneumonia (10.9% vs 9.8%; P < .001), sepsis (38.6% vs 30.7%; P < .001), or respiratory failure (9.3% vs 5.5%; P < .001). Their cultures more often grew Streptococcus pneumoniae (43.7% vs 25.5%; P < .001) and less frequently grew organisms resistant to guideline-recommended antibiotics (25.0% vs 43.7%; P < .001). Patients with an AUD were treated more often with piperacillin-tazobactam (26.2% vs 22.5%; P < .001) but equally as often with anti-methicillin-resistant Staphylococcus aureus agents (32.9% vs 31.8%; P = .11) compared with patients without AUDs. When adjusted for demographic characteristics and insurance, AUD was associated with higher mortality (odds ratio, 1.40; 95% CI, 1.25-1.56), length of stay (risk-adjusted geometric mean ratio, 1.24; 95% CI, 1.20-1.27), and costs (risk-adjusted geometric mean ratio, 1.33; 95% CI, 1.28-1.38). After additional adjustment for differences in comorbidities and risk factors for resistant organisms, AUD was no longer associated with mortality but remained associated with late mechanical ventilation (odds ratio, 1.28; 95% CI, 1.12-1.46), length of stay (risk-adjusted geometric mean ratio, 1.04; 95% CI, 1.01-1.06), and costs (risk-adjusted geometric mean ratio, 1.06; 95% CI, 1.03-1.09). Models segregating patients undergoing alcohol withdrawal showed that poorer outcomes among patients with AUD were confined to the subgroup undergoing alcohol withdrawal.

CONCLUSIONS AND RELEVANCE

This study suggests that, compared with hospitalized patients with community-acquired pneumonia but without AUD, those with AUD less often harbor resistant organisms. The higher age-adjusted risk of death among patients with AUD appears to be largely attributable to differences in comorbidities, whereas greater use of health care resources may be attributable to alcohol withdrawal.

Transdermal delivery of tadalafil using a novel formulation

The aim of this work was to investigate the transdermal gel loaded with tadalafil, a practically insoluble selective phosphodiesterase-5 inhibitor (PDE5) in order to improve the solubility and bioavailability. The solubility of tadalafil in mixed solution of hydroxypropyl-β-cyclodextrin (HPCD), polyethylene glycol (PEG) 400 and tween 80 (T2 solution) was 260.8 ± 4.3 µg/mL and that of tadalafil in modified T2 (M-T2) solution, which tadalafil was dissolved in 20% (w/v) HPCD at first and then mixture solutions of PEG 400 and tween 80 were added, was increased to 344.9 ± 30.6 µg/mL. Four gel formulae were prepared, subsequently in vitro and in vivo skin permeation studies were carried out. Interestingly, tadalafil gel in M-T2 and oleic acid (OA) (F3) could promote the percutaneous absorption of tadalafil by 179.4% in vitro and increase AUC by 223% in vivo compared with tadalafil gel in the absence of M-T2 and OA (F1). Also, there was a finding that tadalafil gel in M-T2 and OA did not cause dermal irritations in an experimental animal.

Time distribution of recurrence risk of oesophageal squamous cell carcinoma with complete resection (R0) in a Chinese population

OBJECTIVES

We aimed to clarify the correlation between clinic-pathological characteristics and the distribution of recurrence probability during follow-up of oesophageal squamous cell carcinoma (OSCC) patients with complete resection analysis by hazard function, and to try to provide evidence-based data for optimal timing for adjuvant therapy.

METHODS

A single-institution, retrospective study was conducted on 553 Chinese patients with OSCC who underwent R0 resection between January 2005 and October 2007. Survival curves were generated using the Kaplan-Meier method, and hazard function was used to analyse the annual recurrence hazard.

RESULTS

The median recurrence-free survival time of these patients was 3.4 years. In univariate analysis, the favourable prognostic factors were gender, smoking status, a tumour length of ≤4.0 cm, tumour invasion thickness, normal level of squamous cell carcinoma (SCC) antigen, pathological T category and pathological N category. In multivariate analysis, pathological T category and pathological N category were independent prognostic factors. Overall, the recurrence hazard curve for the entire cohort showed that the first major recurrence surge began to increase from the first year at 22.97% and peaked at 1.3 years at 27.4% during follow-up. The second recurrence surge peaked during the seventh year at 13.0%. A lower recurrence risk was observed in patients with the following clinic-pathological characteristics: gender, smoking status and N0.

CONCLUSIONS

We identify the presence of two peaks for recurrence risk in Chinese patients with resectable OSCC, which might contribute to choosing the optimal timing for adjuvant therapy after an operation to decrease or delay the recurrence hazard for patients with resectable OSCC.

Substance use (alcohol, areca nut and cigarette) is associated with poor prognosis of esophageal squamous cell carcinoma

BACKGROUND

Few studies have reported the association between lifestyle factors and prognosis of esophageal squamous cell carcinoma (ESCC) and among these, the effects of habitual areca nut chewing have never been examined.

METHODOLOGY/PRINCIPAL FINDINGS

Data from 718 pathology-proven ESCC patients recruited in a multicenter hospital-based case-control study between 2000 and 2008 in Taiwan were analyzed. Clinical and lifestyle information were obtained by chart review and questionnaire survey. Death was confirmed using the National Death Index. The mean age at diagnosis was 59.8 years and 506 (70.5%) patients presented with stage III or IV diseases. The overall 1- and 5-year survival rates were 41.8% and 9.75% respectively. In addition to clinical stage, habitual alcohol drinking was found to be the strongest predictor for ESCC survival, followed by areca chewing and smoking. Compared with non-users, patients who regularly used all three substances (alcohol, areca nut, and cigarette) had 1.52 times the risk of early death (adjusted hazard ratio = 1.52, 95% CI = 1.02-2.27, p = 0.04). In addition, the more the number of substances used, the worse the prognosis of ESCC (adjusted p for trend = 0.01).

CONCLUSIONS/SIGNIFICANCE

Our study found that indulgence in more substances is a significant predictor of ESCC survival. Further mechanistic studies are necessary to elucidate how these substances lead to an adverse outcome.

Considerations regarding use of solvents in in vitro cell based assays

Cell culture systems are widely used for the investigation of in vitro immunomodulatory effects of medicines and natural products. Since many pharmacological relevant compounds are water-insoluble, solvents are frequently used in cell based assays. Although many reports describe the cellular effects of solvents at high concentrations, only a few relate the effects of solvents used at low concentrations. In this report we investigate the interference of three commonly used solvents: Dimethyl sulfoxide (DMSO), ethanol and β-cyclodextrin with five different cell culture systems. The effects of the solvents are investigated in relation to the cellular production of interleukin (IL)-6 or reactive oxygen species (ROS) after lipopolysaccharide (LPS) stimulation. We show that DMSO above 1 % reduces readout parameters in all cell types but more interestingly the 0.25 and 0.5 % solutions induce inhibitory effects in some cell types and stimulatory effects in others. We also found that LPS induced ROS production was more affected than the IL-6 production in the presence of ethanol. Finally we showed that β-cyclodextrin at the investigated concentrations did not have any effect on the LPS induced IL-6 production and only minor effects on the ROS production. We conclude that the effects induced by solvents even at low concentrations are highly relevant for the interpretation of immunomodulatory effects evaluated in cell assays. Furthermore, these results show the importance of keeping solvent concentrations constant in serial dilution of any compound investigated in cell based assays.

Smoking and the outcome of infection

Smoking has substantial local and systemic adverse effects on the immune system, respiratory tract and skin and soft tissues. Smokers are at increased risk of invasive pneumococcal disease, pneumonia, periodontitis, surgical infections, tuberculosis, influenza and meningococcal disease. The results of several studies indicate that smokers with periodontitis or tuberculosis suffer more severe disease. Data on the impact of smoking on sepsis and pneumonia are controversial and limited, and systematic data regarding the outcome of the majority of infections in smokers are scarce. Abundant data indicate that children exposed to environmental tobacco smoke (ETS) suffer from more severe infections. However, information regarding the effects of ETS on the outcome of infections in adults is limited. Various aspects of the relation between smoking and the outcome of bacterial infection (e.g. potential dose-dependent effects and the interactions between smoking and other environmental factors that may affect the course of infectious diseases) remain to be established.

Factors associated with hepatitis C viremia in a large cohort of HIV-infected and -uninfected women

BACKGROUND

Co-infection with hepatitis C virus (HCV) is common among HIV-infected women.

OBJECTIVE

To further our understanding of the risk factors for HCV viremia and the predictors of HCV viral load among women.

STUDY DESIGN

We investigated sociodemographic, immunologic, and virologic factors associated with presence and level of HCV viremia among 1049 HCV-seropositive women, 882 of whom were HIV-infected and 167 HIV-uninfected at their entry into the Women's Interagency HIV Study.

RESULTS

Plasma HCV RNA was detected in 852 (81%) of these 1049 women (range: 1.2-7.8 log(10)copies/ml). HCV-viremic women were more likely to have an HIV RNA level >100,000 copies/ml (P=0.0004), to have reported smoking (P=0.01), or to be Black (P=0.005). They were less likely to have current or resolved hepatitis B infection. HCV RNA levels were higher in women who were >35 years old, or HIV-infected. Current smoking and history of drug use (crack/freebase cocaine, marijuana, amphetamines, or heroin) were each associated with both presence and level of viremia.

CONCLUSIONS

Substance abuse counseling aimed at eliminating ongoing use of illicit drugs and tobacco may reduce clinical progression, improve response to treatment, and decrease HCV transmission by lowering levels of HCV viremia in women.

Depression, Immunity, and Survival in Patients With Hepatobiliary Carcinoma

Purpose

The aims of the present study were to assess the prevalence of depressive symptoms at diagnosis, test the association between depressive symptoms and survival, and preliminarily test a mediational model of depression, immunity, and survival in patients with hepatobiliary carcinoma (HBC).

Patients and Methods

One hundred one patients diagnosed with HBC were prospectively studied. Depressive symptoms were measured at diagnosis using the Center for Epidemiological Studies Depression Scale (CES-D). Sociodemographic and disease-specific data were gathered from the patients' charts. In a subsample of patients, stress; alcohol, tobacco, and drug use; sleep quality; physical activity; social support; natural killer (NK) cell number and cytotoxicity; and plasma levels of interleukin (IL) -4, IL-5, tumor necrosis factor alpha, and interferon gamma were measured. Survival was measured from date of diagnosis to death.

Results

At diagnosis, 37% of patients reported a CES-D score of ≥ 16 (clinical range). Using Cox regression analysis, sociodemographic and disease-specific variables and CES-D score significantly predicted survival (Breslow χ2= 32.4, P = .006). Only vascular invasion (P = .001) and CES-D score ≥ 16 (P = .03) were significant predictors. In a subsample of 23 patients, patients who reported a CES-D score of ≥ 16 were found to have significantly lower NK cell numbers than patients who reported a CES-D score of less than 16 (F1,21= 9.39, P = .003). A robust trend was found in which NK cell number was associated with survival. A mediational model linking depressive symptoms and survival, with NK cell number as a mediator, was preliminarily supported.

Conclusion

Secondary to the high prevalence of depressive symptoms and impact on survival, psychological and pharmacologic interventions should be designed and implemented in patients diagnosed with HBC.

Environmental tobacco smoke exposure: prevalence and mechanisms of causation of infections in children

BACKGROUND AND OBJECTIVES

Environmental tobacco smoke (ETS) exposure is probably one of the most important public health hazards in our community. Our aim with this article is to (1) review the prevalence of ETS exposure in the United States and how this prevalence is often measured in practice and (2) summarize current thinking concerning the mechanism by which this exposure may cause infections in young children.

METHODS

We conducted a Medline search to obtain data published mainly in peer-reviewed journals.

RESULTS

There is still a very high prevalence of ETS exposure among US children ranging from 35% to 80% depending on the method of measurement used and the population studied. The mechanism by which ETS may be related to these infections is not entirely clear but may be through suppression or modulation of the immune system, enhancement of bacterial adherence factors, or impairment of the mucociliary apparatus of the respiratory tract, or possibly through enhancement of toxicity of low levels of certain toxins that are not easily detected by conventional means.

CONCLUSIONS

The prevalence of ETS exposure in the United States is still very high, and its role in causing infections in children is no longer in doubt even if still poorly understood. Research, therefore, should continue to focus on the various mechanisms of causation of these infections and how to best reduce the exposure levels.

Major depression and immunity in alcohol-dependent persons

Altered immunity has been associated with both alcoholism and major depression (MD). We investigated the contribution of MD, as well as alcoholism, to in vitro measures of immunity in inner-city alcohol-dependent (SCID-DSM-III-R) persons and community nonabusers, all otherwise in good health.

METHODS

Alcohol-dependent persons at an ambulatory alcohol treatment center who did not abuse other substances were studied along with the comparison sample (total n=122). Enumerative and functional immune measures included leukocyte and lymphocyte subsets, mitogen response, natural killer cell activity (NKCA), and granulocytic phagocytosis.

RESULTS

Controlling for alcohol dependence, age, gender, racial background, and medical status, MD was associated with decreased phytohemagglutinin (PHA) responses (p<.03), possibly decreased NKCA (p<.08), and increased circulating monocytes (p<.04). Controlling for MD, age, gender, racial background, and medical status, alcohol dependence was associated with decreased circulating B lymphocytes (p<.02), possibly decreased CD56+ (NK) cells (p<.06), and increased monocytes (p<.04). Responses to concanavalin A and pokeweed mitogen, granulocyte functions, and the composition of other leukocyte and lymphocyte subsets showed no evidence of being associated with MD or with alcoholism (p>.1). Secondary analyses exploring factors such as recent alcohol use, cigarette use, and nutrition suggested that these factors accounted for the altered lymphocyte subsets associated with alcoholism and the possibly decreased NKCA with MD. They did not account for the association of MD with increased monocytes and decreased PHA.

DISCUSSION

MD-associated immune changes in alcoholics are modest and consistent with those seen in MD without alcoholism. Some MD- and many alcoholism-associated immune effects appear related to factors such as cigarette use and recent alcohol exposure.

Effects of nicotine on proliferation, cell cycle, and differentiation in immortalized and malignant oral keratinocytes

BACKGROUND

Numerous epidemiological studies have reported that tobacco smoking is a major risk factor for oral cancer, but relatively little is known about the effect of nicotine, a major product of cigarette smoking, on immortalized oral keratinocytes and cancer cells.

METHODS

We investigated the effects of nicotine on the growth and differentiation of immortalized human oral keratinocytes (IHOK), primary oral cancer cells (HN4), metastatic oral cancer cells (HN12), and human skin keratinocytes (HaCaT), in the monolayer and in the three-dimensional (3D) raft cultures using the MTT assay, Western blotting, and cell cycle analysis.

RESULTS

Nicotine inhibited the proliferation of immortalized and malignant keratinocytes in dose- and time-dependent manners as determined by MTT assay. The 3D organotypic culture showed that nicotine at high concentration (300 microM) inhibits epithelial maturation, surface keratinization, and decreased epithelial thickness. Flow cytometry showed that nicotine inhibited cell cycle progression by inducing G(0)/G(1) arrest of HaCaT, IHOK, HN4, and HN12 cells without causing apoptosis. Nicotine treatment increased p21 expression in immortalized cells (HaCaT, IHOK) and oral cancer cells (HN4, HN12), but decreased pRb and p53 expression in oral cancer cells. Moreover, after high-dose nicotine treatment, the involucrin expression increased markedly in immortalized cells, but not in oral cancer cells.

CONCLUSIONS

We demonstrated that nicotine inhibits growth through cell cycle arrest at G(0)/G(1) phase probably by increasing the expression of p21(WAF1/CIP1). Nicotine also affects epithelial differentiation in immortalized and malignant oral keratinocytes. Malignant oral keratinocytes appear to be more resistant to the effects of nicotine on epithelial growth and differentiation as compared to the immortalized cells.

The relationships between substance abuse, psychosocial variables, and natural killer cell enumeration and function in HIV-infected and high-risk uninfected adolescents

This report examines the relationship between substance use, psychosocial stressors, and natural killer (NK) cell enumeration and function in HIV-infected and high-risk uninfected adolescents. We studied the association of demographic characteristics; self-report measures of alcohol, tobacco, and marijuana use; and self-report measures of psychosocial stressors (depressive symptoms, anxiety) with three immune outcomes: NK (CD3(-)CD16(+)CD56(+)) absolute counts, lytic units per peripheral blood mononuclear cells (PBMCs), and lytic units per NK cell. In addition, we determined the association of HIV disease stage, antiretroviral therapy (ART), CD4(+) T-cell count, and viral load with these outcomes in the subset of HIV-infected adolescents.

METHODS

This cross-sectional analysis reports on data collected during a longitudinal observational study of adolescents (the REACH Study). A cross-sectional analysis was performed with data from the first visit for each subject that met criteria for concurrent (within 3 days) assessment of NK number and function, substance use, and psychosocial data. The data set represented 501 subjects. Analyses were performed separately for the HIV-seropositive and seronegative adolescents. In the HIV-seronegative population, there were no significant predictors of NK cell count and only female gender was significantly associated with CD3(-)CD16(+)CD56(+) NK lytic units per PBMC. Analysis of the HIV-seronegative cohort also showed that black race was significantly associated with higher lytic units per NK cell.

RESULTS

In HIV-seropositive adolescents, we observed an association of female gender with lower NK cell number and lytic units per PBMC, but not with lytic units per NK cells. Current use of one or two antiretroviral drugs was predictive of lower NK numbers. This drug effect was also noted in the functional assay per PBMC but not per NK cell. Increasing worry scores and no marijuana use over the past 3 months were associated with lower functional NK measures per PBMC in HIV-seropositive youth. Laboratory-confirmed recent marijuana use was highly predictive of increased lytic activity calculated per NK cell. These effects were not observed in similar analyses of data from HIV-seronegative adolescents. Depressive symptoms, assessed with an epidemiologic screening tool, were not found to be predictive of NK cell number or function in either the HIV-seronegative or the HIV-seropositive subset. These findings document associations between substance abuse, psychosocial variables, and NK numbers and function in adolescents.

Microbial infections, immunomodulation, and drugs of abuse

The use of recreational drugs of abuse has generated serious health concerns. There is a long-recognized relationship between addictive drugs and increased levels of infections. Studies of the mechanisms of actions of these drugs became more urgent with the advent of AIDS and its correlation with abused substances. The nature and mechanisms of immunomodulation by marijuana, opiates, cocaine, nicotine, and alcohol are described in this review. Recent studies of the effects of opiates or marijuana on the immune system have demonstrated that they are receptor mediated, occurring both directly via specific receptors on immune cells and indirectly through similar receptors on cells of the nervous system. Findings are also discussed that demonstrate that cocaine and nicotine have similar immunomodulatory effects, which are also apparently receptor mediated. Finally, the nature and mechanisms of immunomodulation by alcohol are described. Although no specific alcohol receptors have been identified, it is widely recognized that alcohol enhances susceptibility to opportunistic microbes. The review covers recent studies of the effects of these drugs on immunity and on increased susceptibility to infectious diseases, including AIDS.

Nicotine reduces the incidence of type I diabetes in mice

Nicotine has been previously shown to have immunosuppressive actions. Type I diabetes is an autoimmune disease resulting from the specific destruction of the insulin-producing pancreatic beta-cells. Thus, we hypothesized that nicotine may exert protective effects against type I diabetes. The multiple low-dose streptozotocin (MLDS)-induced model and spontaneous nonobese diabetic (NOD) mouse model of type I diabetes were used to assess whether nicotine could prevent this autoimmune disease. Blood glucose levels, diabetes incidence, pancreas insulin content, and cytokine levels were measured in both models of diabetes, both to asses the level of protection exerted by nicotine and to further investigate its mechanism of action. Nicotine treatment reduced the hyperglycemia and incidence of disease in both the MLDS and NOD mouse models of diabetes. Nicotine also protected against the diabetes-induced decrease in pancreatic insulin content observed in both animal models. The pancreatic levels of the Th1 cytokines interleukin (IL)-12, IL-1, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma were increased in both MLDS-induced and spontaneous NOD diabetes, an effect prevented by nicotine treatment. Nicotine treatment increased the pancreatic levels of the Th2 cytokines IL-4 and IL-10. Nicotine treatment reduces the incidence of type I diabetes in two animal models by changing the profile of pancreatic cytokine expression from Th1 to Th2.

Fatores de risco e medidas profiláticas nas pneumonias adquiridas na comunidade

Este artigo revisa os efeitos do envelhecimento, tabagismo, DPOC, insuficiência cardíaca, colonização da orofaringe, aspiração (micro e macro), alcoolismo, cirrose hepática, deficiência nutricional, imunossupressão e fatores ambientais sobre o risco de adquirir pneumonia na comunidade e sua gravidade. Na segunda parte, é feita revisão sobre a ação profilática das vacinas antiinfluenza e antipneumococo, assim como a ação das drogas antivirais, na profilaxia e tratamento das pneumonias adquiridas na comunidade.

Severe community-acquired pneumonia. Risk factors and follow-up epidemiology

The aim of the study was to determine risk factors for severe community-acquired pneumonia (CAP) as well as to compare microbial patterns of severe CAP to a previous study from our respiratory intensive care unit (ICU) originating from 1984 to 1987. Patients admitted to the ICU according to clinical judgment were defined as having severe CAP. For the study of risk factors, a hospital-based case-control design was used, matching each patient with severe CAP to a patient hospitalized with CAP but not requiring ICU admission. Microbial investigation included noninvasive and invasive techniques. Overall, 89 patients with severe CAP were successfully matched to a control patient. The presence of an alcohol ingestion of >/= 80 g/d (odds ratio [OR] 3.9, 95% confidence interval [CI] 1.4 to 10.6, p = 0.008) was found to be an independent risk factor for severe CAP and prior ambulatory antimicrobial treatment (OR 0.37, 95% CI 0.17 to 0.79, p = 0.009) to be protective. Streptococcus pneumoniae (24%) continued to be the most frequent pathogen; however, 48% of strains were drug-resistant. "Atypical" bacterial pathogens were significantly more common (17% versus 6%, p = 0.006) and Legionella spp. less common (2% versus 14%, p = 0.004) than in our previous study, whereas gram-negative enteric bacilli (GNEB) and Pseudomonas aeruginosa continued to represent important pathogens (6% and 5%, respectively). Our findings provide additional evidence for the importance of the initiation of early empiric antimicrobial treatment for a favorable outcome of CAP. Variations of microbial patterns are only in part due to different epidemiological settings. Therefore, initial empiric antimicrobial treatment will also have to take into account local trends of changing microbial patterns.

Sudden infant death syndrome, virus infections and cytokines

Many epidemiological risk factors identified for sudden infant death syndrome (SIDS) suggest a viral aetiology, e.g. exposure to cigarette smoke and winter peak, mild respiratory symptoms. Virus infections and bacterial toxins induce cytokine activity and it has been suggested that uncontrolled inflammatory mediators could be involved in some cases of SIDS. The aim of this review was to assess the evidence for virus infection in SIDS and to examine those findings in relation to individual variations in cytokine responses and various pathophysiological mechanisms proposed for SIDS such as sleep derangement, hypoxia, cardiac arrhythmia, vascular hypotonicity and hypoglycaemia.

Etiology of community-acquired pneumonia: impact of age, comorbidity, and severity

The aim of this study was to determine the etiology of community-acquired pneumonia (CAP) and the impact of age, comorbidity, and severity on microbial etiologies of such pneumonia. Overall, 395 consecutive patients with CAP were studied prospectively during a 15-mo period. Regular microbial investigation included examination of sputum, blood culture, and serology. Sampling of pleural fluid, transthoracic puncture, tracheobronchial aspiration, and protected specimen brush (PSB) sampling were performed in selected patients. The microbial etiology was determined in 182 of 395 (46%) cases, and 227 pathogens were detected. The five most frequent pathogens were Streptococcus pneumoniae (65 patients [29%]), Haemophilus influenzae (25 patients [11%]), Influenza virus A and B (23 patients [10%]), Legionella sp. (17 patients [8%]), and Chlamydia pneumoniae (15 patients [7%]). Gram-negative enteric bacilli (GNEB) accounted for 13 cases (6%) and Pseudomonas aeruginosa for 12 cases of pneumonia (5%). Patients aged < 60 yr were at risk for an "atypical" bacterial etiology (odds ratio [OR]: 2.3; 95% confidence interval [CI]: 1.2 to 4.5), especially Mycoplasma pneumoniae (OR: 5.3; 95% CI: 1.7 to 16.8). Comorbid pulmonary, hepatic, and central nervous illnesses, as well as current cigarette smoking and alcohol abuse, were all associated with distinct etiologic patterns. Pneumonia requiring admission to the intensive care unit was independently associated with the pathogens S. pneumoniae (OR: 2.5; 95% CI: 1.3 to 4.7), gram-negative enteric bacilli, and P. aeruginosa (OR: 2.5; 95% CI: 0.99 to 6.5). Clinical and radiographic features of "typical" pneumonia were neither sensitive nor specific for the differentiation of pneumococcal and nonpneumococcal etiologies. These results support a management approach based on the associations between etiology and age, comorbidity, and severity, instead of the traditional syndromic approach to CAP.

Cytokines in detoxified patients with chronic alcoholism without liver disease: increased monocytic cytokine production

BACKGROUND

The aim of the present study was to examine the production of interferon-gamma, tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-6 (IL-6), IL-10, IL-4, IL-5, IL-1 receptor antagonist (IL-1RA), and prostaglandin E2 in relation to the number of leukocytes in the blood of detoxified, chronic alcoholic patients without apparent liver disease (AWLD).

METHODS

Phytohemagglutinin + lipopolysaccharide-induced production of the above variables as well as the number of white blood cells and differentials were determined in detoxified AWLD patients and normal volunteers.

RESULTS

Detoxified AWLD patients have a significantly higher production of IL-6, IL-10, TNF-alpha, GM-CSF, and IL-1RA and significantly increased numbers of leukocytes and neutrophils compared to normal volunteers.

CONCLUSIONS

Detoxified AWLD patients show an increased production of proinflammatory cytokines, i.e., IL-6, TNF-alpha, and GM-CSF, as well as negative immunoregulatory proteins, such as IL-10 and IL-1RA.

Reduction of natural killer cytotoxic activity in major depression: interaction between depression and cigarette smoking

OBJECTIVE

Epidemiological data suggest that the presence of a depressed mood combined with cigarette smoking increases the risk of cancer at sites associated with smoking and at sites not associated with smoking. This study tested the hypothesis that major depression and smoking together contribute to a decline of natural killer cell (NK) activity, an immune parameter thought to be important in immune surveillance.

METHODS

A sample of 245 men were stratified into four groups: control subjects who were not smokers, control subjects who were smokers, subjects with major depression who were not smokers, and subjects with major depression who were smokers. Blood samples were obtained for measurement of total white blood cell (WBC) counts, differential cell counts, and assay of NK activity.

RESULTS

Major depression and cigarette smoking interact and were together associated with changes in WBC counts and NK activity. Depressed subjects who were smokers had higher WBC counts (p < .001) and lower NK activity (p < .01) than depressed nonsmoking subjects. However, WBC counts and NK activity were similar in control smokers and nonsmokers. Backward elimination regression analyses showed that the interaction of depression and smoking significantly (p < .001) predicted WBC counts and NK activity.

CONCLUSIONS

This study extends previous findings of immune alterations in patients with major depression. Major depression and smoking interact and together contribute to an elevation of total WBC count and a decline of NK activity.

The effects of nicotine on the immune system

Although considerable work has been done on the potential health effects of smoking, little is known about the contribution of nicotine to those effects. This paper presents an overview of the immune system, and a discussion of the existing literature on the effects of tobacco smoke and nicotine on immunity. Treatment with nicotine has been shown to influence all aspects of the immune system, including alterations in humoral and cellular immunity. In addition, preliminary data suggest that gender and genetic factors impact on the immunological effects of nicotine. Finally, the possible mechanisms that might mediate the effects of nicotine are discussed.

Recovery from 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced immunosuppression in A/J mice by treatment with nonsteroidal anti-inflammatory drugs

BACKGROUND

We have previously reported that nonsteroidal anti-inflammatory drugs inhibit lung tumorigenesis induced by the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in mice.

PURPOSE

The aims of this study were to determine if NNK suppresses humoral (i.e., antibody) and cellular immune responses in mice and if nonsteroidal anti-inflammatory drugs could attenuate these immune responses.

METHODS

Female A/J mice (7-8 weeks old) were fed nonsteroidal anti-inflammatory drugs starting 2 weeks before the beginning of NNK treatment (9.1 mg per mouse in total) and continuing through the 7 weeks of NNK treatment. Eight groups (two control groups and six experimental groups) of 10 mice each were used per experiment. Animals in the two control groups received the same diet and water as animals in the six experimental groups; one control group received no nonsteroidal anti-inflammatory drugs or NNK and the other control group received only NNK. The primary humoral and cellular immune responses to the various treatments were assayed by the plaque-forming cell technique and by measurement of natural killer cell cytotoxic activity, respectively. At the end of each experiment, the animals were killed, blood was collected, plasma was prepared, and levels of the immune system modulator prostaglandin E2 were measured.

RESULTS

NNK treatment inhibited the plaque-forming cell response by approximately 50%; this inhibition was attenuated by treatment with sulindac or acetylsalicylic acid (P = .0001 for both). In contrast, treatment with naproxen, which had no chemopreventive (i.e., tumor inhibitory) efficacy, further increased by 26% (P = .05) the immunosuppressive effect of NNK. The cytotoxic activity of splenic natural killer cells against YAC-1 cells was reduced by 60% (P = .002); treatment with acetylsalicylic acid (254 mg/kg of diet) reduced the NNK-induced natural killer cell cytotoxicity inhibition by 50% (P = .02), whereas the administration of the specific cyclooxygenase-2 inhibitor NS-398 (7 mg/kg of diet) resulted in an almost complete recovery (approximately 95%, P = .04) of natural killer cell activity. The prostaglandin E2 plasma concentration was approximately 100% greater in NNK-treated mice than in untreated mice. Treatment of the mice with nonsteroidal anti-inflammatory drugs attenuated this elevation (from approximately 25% to 100%), and NS-398 (7 mg/kg of diet) was the most effective (100%).

CONCLUSIONS AND IMPLICATIONS

The ability of various nonsteroidal anti-inflammatory drugs to inhibit NNK-induced carcinogenesis appears to be directly related to the ability of these drugs to inhibit NNK-induced immunosuppression. Our results suggest that the chemopreventive effect of nonsteroidal anti-inflammatory drugs may be mediated through the modulation of prostaglandin E2 synthesis.

Tobacco and smoking: environmental factors that modify the host response (immune system) and have an impact on periodontal health

This review summarizes the current data on the effects of smoking and tobacco on the immune system and its potential impact on periodontal health. Smokers are 2.5-6 times more likely to develop periodontal disease than non-smokers, and there is evidence for a direct correlation between the number of cigarettes smoked and the risk of developing disease. Tobacco users also tend to exhibit increased severity of periodontal disease. Direct correlations between tobacco use and increased attachment loss and pocket depth and reduced bone crest height have been reported. Although the correlation between tobacco use and periodontal disease is quite strong, the role of tobacco in the pathogenesis of periodontal disease is uncertain. Recent studies indicate that one potential mechanism is that tobacco use exacerbates periodontal disease because it alters the immune response to periodontal pathogens. Indeed, smokers exhibit increased numbers of peripheral blood mononuclear phagocytes which appear to be functionally compromised. Inadequate phagocyte activity could reduce the clearance of pathogens from the oral cavity and thereby facilitate the development of periodontal disease. Tobacco-exposed B- and T-lymphocytes exhibit reduced proliferative capacities which could limit the production of protective immunoglobulins against oral pathogens. The risk factors for periodontal disease can be broadly classified as genetic, environmental, host-response factors, and host-related factors such as age. Tobacco, an environmental factor, undermines the host response and may facilitate the development and progression of periodontal disease. This review highlights the inter-relatedness of two of the risk factors associated with periodontal disease.

Passive smoking is a risk factor for esophagitis in children

A case-control study was undertaken to determine whether esophagitis in children correlated with exposure to parental cigarette smoking. At least one parent smoked in 77 (79%) of 97 families in the study group, compared with 42 (38.9%) of the 108 families in the control group (p < 0.001). Passive smoking is a risk factor for the development of esophagitis in children, providing added support for public health efforts to restrict childhood exposure to tobacco smoke.

Selective inhibitory effects of stress hormones on natural killer (NK) cell activity of lymphocytes from AIDS patients

To examine the potential role of stress hormones in the progression of HIV infections, we developed an in vitro model system that investigates the effects of cortisol, adrenocorticotropin-releasing hormone (ACTH) and beta-endorphin on the natural killer cell activity of lymphocytes from normal subjects and AIDS patients. The system employs a 4 hr 51Cr release assay and K562 target cells. Direct addition of cortisol (0.05, 0.1, and 0.2 microgram/ml) or ACTH (10(-6) to 10(-8) M) to the mixture of effector and prelabeled target cells did not produce any significant immunoregulatory effects on the NK cell activity of normal lymphocytes. Direct addition of beta-endorphin (10(-13) to 10(-17) M) to the mixture of effector and prelabeled target cells did not produce any significant immunoregulatory effects on the NK cell activity of lymphocytes from normal or AIDS subjects. However, cortisol and ACTH significantly inhibited the NK activity of lymphocytes from AIDS patients. The selective inhibitory effects of cortisol and ACTH in patients with HIV infections are consistent with a model which proposes that stress related neurohormones and/or neuropeptides may be involved in the progression of HIV infections.

Immune function in cigarette smokers who quit smoking for 31 days

A group of 28 healthy, white, male, light-to-moderate smokers, 21 to 35 years of age, were offered a financial inducement to abstain from smoking for 31 days. A matched control group of 11 smokers were paid to continue smoking during the same period. Nonspecific parameters of immune system function were monitored before and at various times after smoking abstinence. Abstinence increased natural killer cell cytotoxic activity but did not alter mitogen-induced T-lymphocyte proliferation as measured by responses to concanavalin A or phytohemagglutinin. Serum cortisol concentrations also decreased after smoking cessation; however, changes in immune function were not correlated with serum cortisol change, nor with indices of smoking such as plasma nicotine and cotinine levels. Responses to concanavalin A and phytohemagglutinin were positively correlated with change in self-reported alcohol ingestion during smoking abstinence. Results indicate that elevation in natural kill cell cytotoxic activity is detectable within 1 month of smoking cessation, even in light-to-moderate smokers. However, elevation in natural killer cell cytotoxic activity appears not to be directly related to cessation-induced reductions in plasma nicotine, cotinine, or circulating cortisol levels.

Activation of human lymphomononuclear cells by peptides derived from extracellular matrix proteins

A series of peptides of 15 amino acids with sequences contained in human extracellular matrix (ECM) proteins (fibronectin, laminin A, laminin B1, tenascin, undulin, alpha 1-chain of type IV and VIII collagen and alpha 2-chain of type VIII collagen) have been synthesized. The selected structures conformed to the following pattern: (i) Pro at position 6, (ii) Leu, Lys, Ile, Val, Ala or Gly at position 2, (iii) Glu or Asp at position 11. Fibronectin and the indicated peptides, when present in cultures of lymphomononuclear cells from healthy donors, promoted stimulation of monocytes manifested by a release of IL-1 alpha, IL-beta, IL-6 and TNF alpha; an increase in the percentage of cells expressing CD14, CD16, CD11b and CD14/CD16; an increase in cytotoxicity against HT-29. Cytotoxicity against K562 and Daudi cells (targets of NK and LAK cells) was also observed together with an increase in the percentage of cells expressing CD56, CD56/CD16 (corresponding to NK cells), and CD56/CD8 (corresponding to NK-like lymphocytes), indicating a stimulation of lymphocytes. Activated monocytes and lymphocytes contained a large number of granules with DNAse activity. These results suggest that at least some of the immunological properties of ECM proteins could be accounted for by motifs fulfilling a characteristic sequence pattern shared by all of them.

Effects of ethanol on human natural killer cell activity: in vitro and acute, low-dose in vivo studies

Chronic use of ethanol may cause a variety of immunological abnormalities in humans. In this study, we have determined the effects of an acute, low dose of ethanol (0.5 g/kg), administered either intravenously or orally, to normal, nonalcoholic male volunteers, on natural killer cell (NK) activity. We have also examined the effects of a 4-hr incubation with ethanol, in concentrations ranging from 0 to 320 mg/dl, on human NK activity in vitro. NK activity was measured by the 51Cr release assay technique in all of these studies, using peripheral blood mononuclear cells prepared from blood obtained from healthy, nonalcoholic volunteers. Eight subjects received ethanol in vivo; cells from nine subjects were used for the in vitro studies. Blood ethanol concentrations were determined at multiple time points before and after ethanol administration for the in vivo studies; for the in vitro studies, ethanol concentrations were measured from each assay sample both before and after the incubation period. Gas chromatography was used for determinations of both blood alcohol and medium ethanol concentrations. Results of the in vivo studies showed that a single dose of ethanol (0.5 g/kg), administered either intravenously (with resultant peak blood levels transiently up to 89 mg/dl) or orally (with resultant peak blood levels transiently up to 40 mg/dl at the time of the NK assay), did not alter NK activity. However, results of the in vitro studies showed a significant dose-dependent decrease (p < 0.001) in NK activity when ethanol exposure was sustained for 4 hr at concentrations of 80 mg/dl and above.(ABSTRACT TRUNCATED AT 250 WORDS)

Selective inhibition by alcohol and cortisol of natural killer cell activity of lymphocytes from cord blood

1. The immunosuppressive effects of drugs such as alcohol or hormones such as cortisol may be age-related. To test this hypothesis, the authors investigated the in vitro effects of ethanol (EtOH) and cortisol on Natural Killer (NK) cell activity of lymphocytes from normal cord blood in comparison with that of lymphocytes from normal adult peripheral blood. 2. K562, an erythroleukemia cell line, was used as a target in a 4 hr 51Cr release assay. 3. Ethanol at 0.3% (V/V) and cortisol at 0.05, 0.1 and 0.2 microgram/ml concentrations, added directly to a mixture of effector and target cells significantly suppressed the NK activity of cord blood lymphocytes in a dose dependent fashion, whereas similar concentrations of either EtOH or cortisol did not manifest significant immunoregulatory effects on NK cell activity of normal adult lymphocytes. 4. Pre-treatment of the target with either EtOH or cortisol for 4 hours did not affect cytotoxicity. Inhibition of cytotoxicity was also not due to direct toxicity of effector cells because lymphocytes treated with either EtOH or cortisol showed normal 51Cr release and their viability was comparable to that of untreated control cells. 5. This suggests a selective inhibitory effect of EtOH and cortisol on NK activity of neonatal lymphocytes that may be of clinical significance.

Suppression of tumor necrosis factor production by alcohol in lipopolysaccharide-stimulated culture

Many studies have shown that alcohol consumption is associated with alteration in immune responses and increased incidence of infection in the host. Tumor necrosis factor (TNF) is a potent soluble mediator of immunoregulation and inflammation, and plays a very important role in host's defenses against infection and tumor. We propose that one of the mechanisms of alcohol-mediated immunosuppression may be due to a defect in the synthesis and release of the TNF. To determine this, we studied the direct effect of alcohol on lipopolysaccharide (LPS)-induced TNF production by whole blood and total mononuclear cell from normal subjects. Aliquots of blood samples (1 ml) or ficoll-hypaque separated total mononuclear cells (1 x 10(6)/ml) were cultured with different concentrations of either ethanol or acetaldehyde in the presence or absence of LPS for 4 hr at 37 degrees C. Plasma samples and culture supernatants were assayed for TNF levels in a bioassay using a TNF-sensitive WEHI 164 subclone 13 cell line. LPS at 10 micrograms/ml produced a maximal level of TNF compared with lower (1 micrograms/ml) or higher concentration (50 micrograms/ml) of LPS. Kinetics studies showed that an incubation time of 4 hr with LPS produced a maximum level of TNF production by blood. Alcohol, as low as 0.1% concentration, produced significant suppression of LPS-induced TNF production by whole blood, whereas alcohol at 0.2 and 0.3% concentrations were required to produce a significant suppression of TNF production by separated mononuclear cells. Anti-TNF-alpha antibodies significantly neutralized the LPS-induced TNF that suggests that blood monocytes may be the primary source of TNF production.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunomodulation induced by synthetic peptides derived from Staphylococcus aureus protein A

Peptides from 10 to 22 amino acids containing sequences encompassed by Staphylococcus aureus protein A were synthesized. Some of these peptides, when present in cultures of lymphomononuclear cells from healthy donors or from cancer patients (melanoma, breast carcinoma, non-Hodgkin lymphoma and renal cell carcinoma) promoted: (i) changes in the phenotype of the lymphomononuclear population, (ii) stimulation of monocytes (release of IL-1 and TNF-alpha), and (iii) an increase in cytotoxicity against K562, Daudi and HT-29 cells. Isolated monocytes responded also to those peptides with a release of IL-1 and TNF alpha and an increase of cytotoxicity against HT-29 cells. It was found that the active peptides had the following structural pattern: a length of at least 15 amino-acid residues with a proline at position 6, valine, leucine, isoleucine, glycine, alanine or lysine at position 2, and glutamic or aspartic acid at position 11. Replacement of Pro at position 6 with any other residue turned the peptide inactive. Replacement of residues at positions 2 and 11 with amino-acid residues other than those required for activity resulted in compounds with a marked decrease in the immunomodulating properties described, or lacking these properties altogether.

Selective effect of alcohol on cellular immune responses of lymphocytes from AIDS patients

In this study we examined the in vitro effects of alcohol on the proliferative responses of lymphocytes from healthy donors and AIDS patients to a recombinant fusion peptide, env-gag, corresponding to portions of the gp41 envelope (env) and internal core (gag) proteins of HIV. The effects of alcohol (ETOH) on the natural killer (NK) cell activities of lymphocytes from healthy donors and patients with AIDS were also investigated. Peripheral blood mononuclear cells from both normal donors and AIDS patients produced significant levels of lymphocyte proliferative responses to the HIV env-gag peptide; however, these responses were significantly higher in patients with AIDS, showing the specificity of the response. The env-gag-induced proliferative responses of lymphocytes from normal subjects were significantly suppressed when cultures contained only higher levels of ETOH (0.2% and 0.3%), whereas ETOH even at a lower level (0.1%) produced significant suppression of the env-gag-induced proliferation of lymphocytes only from AIDS patients. Direct addition of ETOH at concentrations of 0.1%, 0.2%, and 0.3% to cultures of lymphocytes from normal donors and NK target cells did not produce significant suppression of NK cell activities. However, ETOH at concentrations of 0.2% and 0.3% significantly suppressed the NK activities of lymphocytes from AIDS patients, and the suppressive effect was observed at all E:T cell ratios examined. Control peptide from the Escherichia coli expression vector did not produce any significant effect on lymphocyte proliferative responses or NK activity of both normal donors and AIDS patients.(ABSTRACT TRUNCATED AT 250 WORDS)

'Normal' cigarette smoking increases free cortisol in habitual smokers

In habitual smokers salivary cortisol responses to cigarette smoking were investigated. In the first study, 31 adults assigned to two experimental groups smoked either one or two cigarettes of their preferred brand. Mean salivary cortisol levels were significantly elevated after smoking of two cigarettes. In the second study, 10 smokers and 10 nonsmokers provided saliva samples at 20 min intervals over a 12-hr period. While environmental stimuli were paralleled in both groups overall cortisol output was significantly elevated in the smokers. These data suggest that 'normal' cigarette smoking can increase free cortisol levels.