Microbial infections, immunomodulation, and drugs of abuse

Heroin inhibits HIV-restriction miRNAs and enhances HIV infection of macrophages

Although opioids have been extensively studied for their impact on the immune system, limited information is available about the specific actions of opioids on intracellular antiviral innate immunity against HIV infection. Thus, we investigated whether heroin, one of the most abused drugs, inhibits the expression of intracellular HIV restriction microRNA (miRNA) and facilitates HIV replication in macrophages. Heroin treatment of macrophages enhanced HIV replication, which was associated with the downregulation of several HIV restriction miRNAs. These heroin-mediated actions on the miRNAs and HIV could be antagonized by naltrexone, an opioid receptor antagonist. Furthermore, the in vitro negative impact of heroin on HIV-associated miRNAs was confirmed by the in vivo observation that heroin addicts had significantly lower levels of macrophage-derived HIV restriction miRNAs than those in the control subjects. These in vitro and in vivo findings indicate that heroin use compromises intracellular anti-HIV innate immunity, providing a favorable microenvironment for HIV survival in the target cells.

Impact of cocaine abuse on HIV pathogenesis

Over 1.2 million people in the United States are infected with the human immunodeficiency virus type 1 (HIV-1). Tremendous progress has been made over the past three decades on many fronts in the prevention and treatment of HIV-1 disease. However, HIV-1 infection is incurable and antiretroviral drugs continue to remain the only effective treatment option for HIV infected patients. Unfortunately, only three out of ten HIV-1 infected individuals in the US have the virus under control. Thus, majority of HIV-1 infected individuals in the US are either unaware of their infection status or not connected/retained to care or are non-adherent to antiretroviral therapy (ART). This national public health crisis, as well as the ongoing global HIV/AIDS pandemic, is further exacerbated by substance abuse, which serves as a powerful cofactor at every stage of HIV/AIDS including transmission, diagnosis, pathogenesis, and treatment. Clinical studies indicate that substance abuse may increase viral load, accelerate disease progression and worsen AIDS-related mortality even among ART-adherent patients. However, confirming a direct causal link between substance abuse and HIV/AIDS in human patients remains a highly challenging endeavor. In this review we will discuss the recent and past developments in clinical and basic science research on the effects of cocaine abuse on HIV-1 pathogenesis.

Acute alcohol exposure has an independent impact on C-reactive protein levels, neutrophil CD64 expression, and subsets of circulating white blood cells differentiated by flow cytometry in nontrauma patients

Acute and massive alcohol exposure (blood alcohol concentration of ≥1 g/L) is a common way to consume alcohol. In a prospective study performed in critically ill nontrauma patients, we compared C-reactive protein (CRP) values, circulating subsets of white blood cells, and neutrophil CD64 indexes recorded at admission to the intensive care unit between abstinent or moderate drinkers (n = 173), patients with acute or chronic alcohol exposure (n = 32), and patients with acute exposure but not chronically exposed to alcohol (n = 27). Values for CRP (P < 0.001), circulating neutrophils (P < 0.001), and neutrophil CD64 indexes (P < 0.001) were significantly lower in patients acutely exposed compared with the other patients, whereas values for B lymphocytes (P < 0.001) and cytotoxic (P < 0.001) and noncytotoxic T lymphocytes (P < 0.001) were significantly higher. After multiple regression analysis, alcohol exposure remained independently associated with values of CRP, neutrophils CD4 indexes, cytotoxic and noncytotoxic T lymphocytes, and CD16-negative and -positive monocytes. These results were not affected by the presence or absence of infection at admission. Our results suggest that in nontrauma critically ill patients, acute alcohol exposure diminishes inflammation and increases numbers of circulating B and T lymphocytes.

Administration of naloxone in combination with recombinant Plasmodium vivax AMA-1 in BALB/c mice induces mixed Th1/Th2 immune responses

Naloxone (NLX) has the ability to shift the immune response to a Th1 profile. Therefore, the adjuvant efficacy of NLX with recombinant P. vivax apical membrane antigen-1(rPvAMA-1) in BALB/c mice was evaluated. Mice were immunized subcutaneously with purified rPvAMA-1 formulated with NLX (doses of 5 mg/kg body weight) alone or in combination with IFA. A significant increase in anti-PvAMA-1 IgG antibody after the second boost (mean OD₄₉₀  = 2·08 and 2·17, in groups received, rPvAMA-1/NLX and rPvAMA-1/NLX/IFA, respectively) was detected. IgG1 and IgG2b were the predominant isotypes in all immunized mouse groups. In immunized mice with rPvAMA-1/NLX (mean: 1036 pg/mL) and with rPvAMA-1/NLX/IFA (mean: 1024 pg/mL), IFN-γ was elicited in response to rPvAMA-1 after the second boost. No detectable IL-4 secretion was determined in all tested groups. In conclusion, the administration of NLX alone or NLX/IFA with rPvAMA-1 in BALB/c mice, which induced mixed Th1/Th2 immune responses, was comparable with that of the same recombinant antigen with CFA/IFA adjuvant. The results indicate that NLX alone may possibly not be considered as a potent Th1 adjuvant in PvAMA-1-based vaccine. However, in order to modulate immune responses from mixed Th1/Th2 to strong and protective Th1 response, further study is warranted on combination of NLX with other adjuvants such as CpG motifs or MPL in proper vaccine formulation. Additionally, dose-response study is necessary to determine the effect of different doses of antigen combined with NLX (at various doses) in Balb/c mice.

The effects of alcohol on the recognition of facial expressions and microexpressions of emotion: enhanced recognition of disgust and contempt

OBJECTIVE

The study compared alcohol's effects on the recognition of briefly displayed facial expressions of emotion (so-called microexpressions) with expressions presented for a longer period.

METHOD

Using a repeated-measures design, we tested 18 participants three times (counterbalanced), after (i) a placebo drink, (ii) a low-to-moderate dose of alcohol (0.17 g/kg women; 0.20 g/kg men) and (iii) a moderate-to-high dose of alcohol (0.52 g/kg women; 0.60 g/kg men). On each session, participants were presented with stimuli representing six emotions (happiness, sadness, anger, fear, disgust and contempt) overlaid on a generic avatar in a six-alternative forced-choice paradigm. A neutral expression (1 s) preceded and followed a target expression presented for 200 ms (microexpressions) or 400 ms. Participants mouse clicked the correct answer.

RESULTS

The recognition of disgust was significantly better after the high dose of alcohol than after the low dose or placebo drinks at both durations of stimulus presentation. A similar profile of effects was found for the recognition of contempt. There were no effects on response latencies.

CONCLUSION

Alcohol can increase sensitivity to expressions of disgust and contempt. Such effects are not dependent on stimulus duration up to 400 ms and may reflect contextual modulation of alcohol's effects on emotion recognition.

High prevalence of cannabis use among Aka foragers of the Congo Basin and its possible relationship to helminthiasis

OBJECTIVES

Little is known about cannabis use in hunter-gatherers. Therefore, we investigated cannabis use in the Aka, a population of foragers of the Congo Basin. Because cannabis contains anthelminthic compounds, and the Aka have a high prevalence of helminthiasis, we also tested the hypothesis that cannabis use might be an unconscious form of self-medication against helminths.

METHODS

We collected self- and peer-reports of cannabis use from all adult Aka in the Lobaye district of the Central African Republic (n = 379). Because female cannabis use was low, we restricted sample collection to men. Using an immunoassay for Δ9-tetrahydrocannabinol-11-oic acid (THCA), a urinary biomarker of recent cannabis consumption, we validated cannabis use in men currently residing in camps near a logging road (n = 62). We also collected stool samples to assay worm burden. A longitudinal reinfection study was conducted among a subsample of the male participants (n = 23) who had been treated with a commercial anthelmintic 1 year ago.

RESULTS

The prevalence of self- and peer-reported cannabis use was 70.9% among men and 6.1% among women, for a total prevalence of 38.6%. Using a 50 ng/ml threshold for THCA, 67.7% of men used cannabis. Cannabis users were significantly younger and had less material wealth than the non-cannabis users. There were significant negative associations between THCA levels and worm burden, and reinfection with helminths 1 year after treatment with a commercial anthelmintic.

CONCLUSIONS

The prevalence of cannabis use among adult Aka men was high when compared to most global populations. THCA levels were negatively correlated with parasite infection and reinfection, supporting the self-medication hypothesis.

Effects of Cannabinoids on T-cell Function and Resistance to Infection

This review examines the effects of cannabinoids on immune function, with a focus on effects on T-cells, as well as on resistance to infection. The paper considers the immune modulating capacity of marijuana, of ∆(9)-THC extracted from the marijuana plant, and synthetic cannabinoids. Of particular interest are synthetic compounds that are CB2 receptor (CB2R) selective agonists. As the CB2R is principally expressed on cells of the immune system, agonists that target this receptor, and not CB1 (which is mainly expressed on neurons), have the possibility of altering immune function without psychoactive effects. The overall conclusion of the studies discussed in this review is that cannabinoids that bind to the CB2 receptor, including ∆(9)-THC and CB2 selective agonists are immunosuppressive. The studies provide objective evidence for potentially beneficial effects of marijuana and ∆(9)-THC on the immune system in conditions where it is desirable to dampen immune responses. Evidence is also reviewed supporting the conclusion that these same compounds can sensitize to some infections through their immunosuppressive activities, but not to others. An emerging area of investigation that is reviewed is evidence to support the conclusion that CB2 selective agonists are a new class of immunosuppressive and anti-inflammatory compounds that may have exceptional beneficial effects in a variety of conditions, such as autoimmune diseases and graft rejection, where it is desirable to dampen the immune response without psychoactive effects.

Possible immunosuppressive effects of drug exposure and environmental and nutritional effects on infection and vaccination

A variety of drugs which are not primarily considered to be immunosuppressive agents have been described to modulate the humoral and cellular immune response in humans or animals. Thereby they may have an influence on the effectiveness and possible side effects of vaccines. This mini review lists some of the different substance classes and also some of endogeneous, infectious, nutritional, and environmental influences with suspected capability to interfere with immunizations. Studies in most cases focused on substances with known immunosuppressive functions, but there is growing evidence for immunomodulatory effects also of commonly used drugs with wide distribution. In particular combinations of those antiproliferative and antiphlogistic side effects of different substance classes have not been studied in detail but may substantially interfere with the development of a functional humoral and cellular immune response. The drugs of importance include antipyretics, anticoagulants, tranquilizers, and substances influencing lipid metabolism but also commonly used drugs of abuse like alcohol or cannabinoids. Additional substances of environmental, nutritional, or microbiological origin may also play a role but their combinatory/synergistic effects have been disregarded so far due to the lack of systematic data and the complex study designs necessary to elucidate those complex epidemiologic questions.

Alcohol-induced miR-27a regulates differentiation and M2 macrophage polarization of normal human monocytes

Alcohol abuse is a leading cause of liver disease characterized by liver inflammation, fatty liver, alcoholic hepatitis, or liver cirrhosis. Immunomodulatory effects of alcohol on monocytes and macrophages contribute to alcoholic liver disease. Alcohol use, an independent risk factor for progression of hepatitis C virus (HCV) infection-mediated liver disease, impairs host defense and alters cytokine production and monocyte/macrophage activation. We hypothesized that alcohol and HCV have synergistic effects on the phenotype and function of monocytes. Our data show that acute alcohol binge drinking in healthy volunteers results in increased frequency of CD16(+) and CD68(+) and M2-type (CD206(+), dendritic cell [DC]-SIGN(+)-expressing and IL-10-secreting) circulating CD14(+) monocytes. Expression of HCV-induced CD68 and M2 markers (CD206 and DC-SIGN) in normal monocytes was further enhanced in the presence of alcohol. The levels of microRNA (miR)-27a was significantly upregulated in monocytes cultured in the presence of alcohol or alcohol and HCV as compared with HCV alone. The functional role of miR-27a in macrophage polarization was demonstrated by transfecting monocytes with an miR-27a inhibitor that resulted in reduced alcohol- and HCV- mediated monocyte activation (CD14 and CD68 expression), polarization (CD206 and DC-SIGN expression), and IL-10 secretion. Overexpression of miR-27a in monocytes enhanced IL-10 secretion via activation of the ERK signaling pathway. We found that miR-27a promoted ERK phosphorylation by downregulating the expression of ERK inhibitor sprouty2 in monocytes. Thus, we identified that sprouty2 is a target of miR-27a in human monocytes. In summary, our study demonstrates the regulatory role of miR-27a in alcohol-induced monocyte activation and polarization.

Inflammatory response in heroin addicts undergoing methadone maintenance treatment

Opioid addiction influences many physiological functions including reactions of the immune system. The objective of this study was to investigate the immune system function in heroin addicted patients undergoing methadone maintenance treatment (MMT) compared to healthy controls. We tested the cytokine production of IL-1β, IL-6, IL-8, IL-10 and tumor necrosis factor (TNF)-α from a group of heroin addicts (n=34) and healthy controls (n=20). The results show that production of IL-1β, IL-6 and IL-8 was significantly higher in the group of methadone-maintained patients than in the healthy control group. Plasma TNF-α and IL-6 levels were significantly correlated with the dairy methadone dosage administered, and the IL-1β level was significantly correlated with the duration of methadone maintenance treatment. These findings suggest that methadone maintenance treatment influences the immune system functions of opioid-dependent patients and may also induce long-term systemic inflammation.

Cannabis smoking and serum C-reactive protein: a quantile regressions approach based on NHANES 2005-2010

BACKGROUND

Pre-clinical studies link cannabinoid-1 receptor activation to inflammation and atherosclerotic effects; anti-inflammation and immunosuppression seem to be mediated by cannabinoid-2 receptor activation. In this epidemiological study, we aim to present estimates on suspected cannabis-attributable immunomodulation as manifest in serum C-reactive protein (CRP) levels as non-specific inflammatory markers with interpretable clinical values. With strength of data from recent large nationally representative community sample surveys, the research approach illustrates value of a quantile regressions approach in lieu of the commonly used but relatively arbitrary cutpoints for CRP values.

METHODS

The study population encompasses 20-59 year old participants from the National Health and Nutrition Examination Surveys, 2005-2010 (n=1115 recently active cannabis smokers and 8041 non-smokers, identified via confidential Audio Computer Assisted Self-Interviews). Age, sex, race, education, income-poverty ratio, alcohol consumption, and tobacco smoking also were measured, together with body mass index (BMI), which actually might be on a mediational path. Quantile regressions, with bootstrapping for variance estimation, made it possible to hold these covariates constant while estimating cannabis-CRP associations.

RESULTS

Evidence suggesting possible cannabis-attributable immunomodulation emerges at CRP levels below the median (p<0.05). Whereas BMI might help explain a cannabis link with serum CRP, but BMI-stratified analyses disclosed no appreciable variation of the cannabis-CRP relationship across BMI subgroups.

CONCLUSIONS

Extending pre-clinical research on cannabis-attributable immunomodulation, this study's CRP evidence points toward possible anti-inflammatory effects of cannabis smoking. More definitive evidence can be derived by combining pre-clinical research, studies of patients, and epidemiological research approaches.

Correlates of Trichomonas vaginalis Among Middle Age and Older Adults Who Use Drugs

BACKGROUND

Recent studies have reported high rates of Trichomonas vaginalis among middle age and older adults. Though trichomoniasis risk factors in this age cohort remain largely unknown, illicit drug use has been associated with increased incidence of sexually transmitted infections (STIs). The number of mid-older adults using illicit drugs has increased significantly in recent years suggesting the need to understand the relationship between drug use and STIs in this age cohort.

OBJECTIVES

This study examined the relationship between drug use, sexual-risk behaviors, and biologically confirmed T. vaginalis in a sample of mid-older and younger adults who reported recent drug use.

METHODS

The cross-sectional design examined the relationship between past 6-month drug use, sexual risk-behaviors, and PCR-confirmed T. vaginalis in 264 adults age 18-64 who were recruited from Baltimore, Maryland. These relationships were also explored in the age-stratified sample among those 18-44 years ("younger") and individuals 45+ years ("mid-older").

RESULTS

Trichomoniasis prevalence did not differ significantly between younger (18.8%) and mid-older (19.1%) adults. Mid-older adults that tested positive for T. vaginalis were more likely to have used marijuana and crack in the past 6 months. Among younger adults, there were no associations between trichomoniasis and past 6-month drug use and sexual-risk behavior.

CONCLUSIONS/IMPORTANCE

Age- and drug-related immune decline is hypothesized to contribute to increase susceptibility to T. vaginalis in mid-older adults. Broad screening for trichomoniasis, particularly among older adults who are often not regarded as at risk for STIs, is needed to control this often asymptomatic infection.

Clinical manifestation and risk factors of tuberculosis infection in Malaysia: case study of a community clinic

INTRODUCTION

The main aim of this study was to describe the clinical manifestation of tuberculosis infection cases in Malaysia and to determine the individual risk factors for their occurrence.

METHODOLOGY

The study adopted a quantitative research approach with use of descriptive statistical approach. The study setting was a community clinic which treats walk in patients who are mainly living and working in the surrounding areas. The study was conducted for a period of one year. All tuberculosis patients who sought treatment in the clinic during the time were included in this study. The total number of cases was 40. Data was collected from the medical records of the tuberculosis patients. The risk factors selected for investigation were demographic characteristics of age and sex, personal habits such as smoking, drug use and alcohol and presence of diseases such as human immunodeficiency virus positive (HIV+), diabetes mellitus, cancer, cyanotic heart disease, renal failure and steroid use.

RESULTS

Patients in the age group ranging from 41 to 50 years had the highest incidence of the infection. Smoking appears to be the most important risk factor for contracting followed by drug abuse, HIV+ infection and diabetes mellitus.

CONCLUSIONS

People with diseases such as diabetes mellitus and HIV that are high risk factors for TB should be screened for TB so that early detection and intervention is possible. Educational programs should be carried out to create awareness among the at risk groups.

[Parvovirus B19 seroprevalence in a group of schizophrenic patients]

BACKGROUND

Schizophrenia is a highly disabling chronic mental illness. It is considerded as a neurodeveloppemental illness resulting from the interaction of genetic and environmental factors. Growing evidence supports the major role of prenatal infections and inflammation in the genesis of schizophrenia. The hypothesis including viral infections has been the subject of several studies and the role of parvovirus B19 (PB19) in the onset of the disease has been suggested. However, there is, up till now, no seroepidemiological evidence of his involvement.

OBJECTIVE

To determine the prevalence of parvovirus B19 (PB19) in schizophrenic patients and in control subjects and to examine clinical associations between viral prevalence, risk factors of infectious disease and clinical features.

METHOD

We carried out a case-control seroepidemiological study in the Psychiatry department of Farhat-Hached general hospital of Sousse (Tunisia). We recruited108 schizophrenic patients and 108 healthy controls free from any psychotic disorder and matched for age and sex. We collected sociodemographic data, medical history, axis I comorbid disorders and infectious risk factors. We assessed patients for psychopathology and severity of illness using respectively the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impressions (CGI). For each study participant, blood sample was collected and levels of IgG and IgM anti-PB19 were measured using the ELISA technique.

RESULTS

The prevalence of IgG antibodies to PB19 was significantly higher in schizophrenic patients than in controls (73.1% vs 60.2%; P=0.04). There were no statistical differences between the two groups regarding the prevalence of IgM antibodies to PB19. No association was found between viral prevalence and sociodemographic data, risk factors for infection or clinical characteristics. The presence of PB19 antibodies was associated with a lower score on the PANSS negative subscale (P=0.04). No other signficative association were found.

CONCLUSIONS

In our study, prevalence of IgG antibodies to PB19 was significantly higher in schizophrenic patients than in controls. This finding supports the hypothesis of the involvement of PB19 in schizophrenia. Further studies including both virological and immunological aspects are needed to better clarify the etiopathogenic mechanisms of schizophrenia which would challenge the management of this disease.

Patient perspectives on buprenorphine/naloxone: a qualitative study of retention during the starting treatment with agonist replacement therapies (START) study

This study examines the barriers and facilitators of retention among patients receiving buprenorphine/naloxone at eight community-based opioid treatment programs across the United States. Participants (n = 105) were recruited up to three and a half years after having participated in a randomized clinical trial comparing the effect of buprenorphine/naloxone and methadone on liver function. Semi-structured interviews were conducted with 67 patients provided with buprenorphine/naloxone who had terminated early and 38 patients who had completed at least 24 weeks of the trial. Qualitative data were analyzed using the constant comparison method. Barriers to buprenorphine/naloxone retention that emerged included factors associated with: (1) the design of the clinical trial; (2) negative medication or treatment experience; and (3) personal circumstances. The facilitators comprised: (1) positive experience with the medication; (2) personal determination and commitment to complete; and (3) staff encouragement and support. The themes drawn from interviews highlight the importance of considering patients' prior experience with buprenorphine/naloxone and methadone, medication preference, personal circumstances, and motivation to abstain from illicit use or misuse of opioids, as these may influence retention. Ongoing education of patients and staff regarding buprenorphine/naloxone, especially in comparison to methadone, and support from staff and peers are essential.

Δ⁹-Tetrahydrocannabinol-induced anti-inflammatory responses in adolescent mice switch to proinflammatory in adulthood

Marijuana abuse is prominent among adolescents. Although Δ(9)-THC, one of its main components, has been demonstrated to modulate immunity in adults, little is known about its impact during adolescence on the immune system and the long-lasting effects in adulthood. We demonstrate that 10 days of Δ(9)-THC treatment induced a similar alteration of macrophage and splenocyte cytokines in adolescent and adult mice. Immediately at the end of chronic Δ(9)-THC, a decrease of proinflammatory cytokines IL- 1β and TNF-α and an increase of anti-inflammatory cytokine IL-10 production by macrophages were present as protein and mRNA in adolescent and adult mice. In splenocytes, Δ(9)-THC modulated Th1/Th2 cytokines skewing toward Th2: IFN-γ was reduced, and IL-4 and IL-10 increased. These effects were lost in adult animals, 47 days after the last administration. In contrast, in adult animals treated as adolescents, a perturbation of immune responses, although in an opposite direction, was present. In adults treated as adolescents, a proinflammatory macrophage phenotype was observed (IL-1β and TNF-α were elevated; IL-10 decreased), and the production of Th cytokines was blunted. IgM titers were also reduced. Corticosterone concentrations indicate a long-lasting dysregulation of HPA in adolescent mice. We measured blood concentrations of Δ(9)-THC and its metabolites, showing that Δ(9)-THC plasma levels in our mice are in the order of those achieved in human heavy smokers. Our data demonstrate that Δ(9)-THC in adolescent mice triggers immune dysfunctions that last long after the end of abuse, switching the murine immune system to proinflammatory status in adulthood.

Risk factors for tuberculosis in foreign-born people (FBP) in Italy: a systematic review and meta-analysis

In Italy, TB notifications in foreign-born people (FBP) are steadily increasing. To investigate this issue we did a meta-analysis on risk factors for FBP people. A systematic search was performed in PubMed and EMBASE from Jan-1980 to Jan-2013. We analysed HIV status, previous TB-treatment, intravenous drug use and alcohol abuse, and multidrug resistant TB. Odd ratio was used as a measure of effect. One and two-stages approaches were used. In the main analysis we used a 2-stages approach to include studies with only aggregate estimates. Among 1996 references, 18 fulfilled inclusion criteria. In TB-affected FBP people positive HIV-status was about 3 times higher than among Italians, after 1996 when combined antiretroviral therapy for HIV was introduced (OR: 2.91; 95%CI: 1.37; 6.17). No association was found between FBP and intravenous drug users in adults; after 1-stage meta-analysis foreign born people from highly endemic countries had a 4 times higher risk to be multidrug resistant TB than Italian people. Finally, TB-affected FBP were less likely than Italians to be alcoholics (OR: 0.10 95%CI: 0.01; 0.84) or of having received previous TB-treatment (OR: 0.55; 95%CI: 0.43; 0.71). An association of multidrug resistant TB with immigrant status as well as an association of Tuberculosis with HIV-positive status in foreign-born people are major findings of this analysis. Drugs and alcohol abuse do not appear to be risk factors for TB in FBP, however they cannot be discharged since may depend on cultural traditions and their role may change in the future along with the migratory waves. An effective control of TB risk factors among migrants is crucial to obtain the goal of TB eradication.

Patterns and correlates of cannabis use among individuals with HIV/AIDS in Maritime Canada

BACKGROUND

The prevalence of cannabis use in HIV-infected individuals is high and its long-term effects are unclear.

METHODS

The prevalence, perceived benefits and consequences, and predictors of cannabis use were studied using a cross-sectional survey in two immunodeficiency clinics in Maritime Canada.

RESULTS

Current cannabis use was identified in 38.5% (87 of 226) of participants. Almost all cannabis users (85 of 87 [97.7%]) acknowledged its use for recreational purposes, with 21.8% (19 of 87) reporting medicinal cannabis use. The majority of patients enrolled in the present study reported mild or no symptoms related to HIV (n=179). Overall, 80.5% (70 of 87) of the cannabis-using participants reported a symptom-relieving benefit, mostly for relief of stress, anorexia or pain. Participants consumed a mean (± SD) of 18.3±21.1 g of cannabis per month and spent an average of $105.15±109.87 on cannabis per month. Cannabis use was associated with rural residence, lower income level, driving under the influence of a substance, and consumption of ecstasy and tobacco. Income level, ecstasy use and tobacco use were retained as significant predictors in regression modelling. Cannabis use was not associated with adverse psychological outcomes.

DISCUSSION

Prolonged previous cannabis consumption and the substantial overlap between recreational and medicinal cannabis use highlight the challenges in obtaining a tenable definition of medicinal cannabis therapy.

Morphine increases hippocampal viral load and suppresses frontal lobe CCL5 expression in the LP-BM5 AIDS model

Chronic opiate abuse accelerates the development of cognitive deficits in human immunodeficiency virus (HIV)-1 patients. To investigate morphine's effects on viral infection of the central nervous system, we applied chronic morphine treatment to the LP-BM5 murine acquired immunodeficiency syndrome (MAIDS) model. LP-BM5 infection induces proinflammatory cytokine/chemokine production, correlating to increased blood-brain barrier permeability. Morphine treatment significantly increased LP-BM5 viral load in the hippocampus, but not in the frontal lobe. Morphine reduced the chemokine CCL5 to non-infected levels in the frontal lobe, but not in the hippocampus. These data indicate a region-specific mechanism for morphine's effects on virally-induced neurocognitive deficits.

Reactivation of human polyomaviruses in immunocompromised states

Infection with various human polyomaviruses (HPyVs) is prevalent, with rates as high as 80 % within the general population. Primary infection occurs during childhood through respiratory or urino-oral transmission. While the majority of individuals exhibit asymptomatic latent infection, those immunocompromised persons are at risk for viral reactivation and disease progression resulting in conditions such as progressive multifocal leukoencephalopathy (PML), trichodysplasia spinulosa, Merkel cell carcinoma, and polyomavirus associated nephropathy. Individuals with altered immune systems due to HIV, organ transplantation, lymphoproliferative diseases, and monoclonal antibody therapy are particularly susceptible to reactivation of various HPyVs. While the specific factors that induce lytic infection have yet to be defined, it is evident that dysfunctional host cellular immune responses allow active infection to occur. Immunosuppressant conditions, such as in chronic alcohol abuse, may serve as added risk factors for reactivation of HPyVs. Since the human HPyV family is rapidly expanding, continuing studies are needed to characterize the role that known and newly discovered HPyVs play in human disease.

Marijuana 'bong' smoking and tuberculosis

The incidence of tuberculosis in the non-indigenous Australian population is low. However, in this paper we report on three cases of cavitating disease, which seem to be associated with a common illicit drug habit namely smoking marijuana using a makeshift pipe or bong. There was a total of 34 positive contacts of these cases and among the contacts sharing a bong with an index case was associated with a sixfold risk of transmission (odds ratio 6.5, confidence interval 1.4-30.4, P = 0.016). When cavitating tuberculosis is detected in a young non-indigenous native born Australian, marijuana use should be considered as a possible risk factor.

Latent tuberculosis among injection drug users in a methadone maintenance treatment program, Taipei, Taiwan: TSPOT.TB versus tuberculin skin test

BACKGROUND

Taiwan has a growing HIV/AIDS epidemic that has recently shifted to an increase among injection drug users (IDUs). IDUs co-infected with HIV and tuberculosis (TB) have a high risk of progression from latent tuberculosis infection (LTBI) to active TB.

METHODS

This study aimed to determine the prevalence and correlates of LTBI among IDUs by TSPOT.TB and tuberculin skin test (TST), in a large methadone program in Taipei, Taiwan. Consenting participants were interviewed by a trained worker regarding sociodemographics, substance use history, and health factors.

RESULTS

Multivariate analysis was used to determine risks associated with each test outcome. Of 287 participants, 165 (58.7%) tested TSPOT.TB-positive and 244 (85.0%) tested TST-positive. The mean age was 44 y, and 7.3% were HIV-infected. Kappa statistics indicated slight concordance between TSPOT.TB and TST. In multivariate analysis, after controlling for potential confounders, TSPOT.TB positivity was significantly associated with age ≥ 50 y (reference, 20-34 y). A history of ever having had contact with a TB-infected person was associated with TST positivity, whereas HIV infection was inversely associated with TSPOT.TB positivity and TST positivity.

CONCLUSIONS

This study shows a high prevalence of LTBI in individuals at risk for HIV infection in Taipei, Taiwan. Future TB prevention programs should particularly focus on IDUs.

Explaining human recreational use of 'pesticides': The neurotoxin regulation model of substance use vs. the hijack model and implications for age and sex differences in drug consumption

Most globally popular drugs are plant neurotoxins or their close chemical analogs. These compounds evolved to deter, not reward or reinforce, consumption. Moreover, they reliably activate virtually all toxin defense mechanisms, and are thus correctly identified by human neurophysiology as toxins. Acute drug toxicity must therefore play a more central role in drug use theory. We accordingly challenge the popular idea that the rewarding and reinforcing properties of drugs "hijack" the brain, and propose instead that the brain evolved to carefully regulate neurotoxin consumption to minimize fitness costs and maximize fitness benefits. This perspective provides a compelling explanation for the dramatic changes in substance use that occur during the transition from childhood to adulthood, and for pervasive sex differences in substance use: because nicotine and many other plant neurotoxins are teratogenic, children, and to a lesser extent women of childbearing age, evolved to avoid ingesting them. However, during the course of human evolution many adolescents and adults reaped net benefits from regulated intake of plant neurotoxins.

Medical and recreational marijuana: commentary and review of the literature

Recent years have seen substantial shifts in cultural attitudes towards marijuana for medical and recreational use. Potential problems with the approval, production, dispensation, route of administration, and negative health effects of medical and recreational marijuana are reviewed. Medical marijuana should be subject to the same rigorous approval process as other medications prescribed by physicians. Legalizing recreational marijuana may have negative public health effects.

Latent and active tuberculosis: evaluation of injecting drug users

Background

There is a high risk of tuberculosis (TB) infection among injecting drug users (IDUs).

Objectives

This study aimed to determine the frequency of latent and active TB infection among IDUs.

Materials and Methods

In a cross-sectional study between 2008 and 2009, IDUs referred to the methadone maintenance treatment (MMT) centers in Hamedan-Iran, undergone tuberculin skin test (PPD; purified protein derivative) were recruited. The participants with positive results for PPD test (> 5 mm and > 10 mm in HIV positive and negative cases), undergone other complementary procedures such as chest-X-ray and sputum smear test.

Results

Overall, 268 IDUs between 18 and 70 (mean: 34.5 [8.2]) years were included in the study. PPD test had positive findings in 49 cases (18.3%). There was no significant difference of PPD positivity between HIV positive and negative participants (17.7% vs. 18.5%). An active TB was found among IDUs.

Conclusions

The high prevalence of latent and active TB among IDUs indicates the need for TB screening tests among this population.

Susceptibility genes are enriched in those of the herpes simplex virus 1/host interactome in psychiatric and neurological disorders

Herpes simplex virus 1 (HSV-1) can promote beta-amyloid deposition and tau phosphorylation, demyelination or cognitive deficits relevant to Alzheimer's disease or multiple sclerosis and to many neuropsychiatric disorders with which it has been implicated. A seroprevalence much higher than disease incidence has called into question any primary causal role. However, as also the case with risk-promoting polymorphisms (also present in control populations), any causal effects are likely to be conditional. During its life cycle, the virus binds to many proteins and modifies the expression of multiple genes creating a host/pathogen interactome involving 1347 host genes. This data set is heavily enriched in the susceptibility genes for multiple sclerosis (P = 1.3E-99) > Alzheimer's disease > schizophrenia > Parkinsonism > depression > bipolar disorder > childhood obesity > chronic fatigue > autism > and anorexia (P = 0.047) but not attention deficit hyperactivity disorder, a relationship maintained for genome-wide association study data sets in multiple sclerosis and Alzheimer's disease. Overlapping susceptibility gene/interactome data sets disrupt signalling networks relevant to each disease, suggesting that disease susceptibility genes may filter the attentions of the pathogen towards particular pathways and pathologies. In this way, the same pathogen could contribute to multiple diseases in a gene-dependent manner and condition the risk-promoting effects of the genes whose function it disrupts.

Morphine prevents lipopolysaccharide-induced TNF secretion in mast cells blocking IκB kinase activation and SNAP-23 phosphorylation: correlation with the formation of a β-arrestin/TRAF6 complex

We have previously shown that morphine pretreatment inhibits mast cell-dependent TNF production after LPS injection in the murine peritoneal cavity. In this study, we used bone marrow-derived mast cells (BMMCs) to investigate the molecular mechanisms of that inhibition. We found that morphine prevented LPS-induced TNF secretion in these cells. The observed inhibition was not due to morphine-induced TLR4 internalization and it was related to the blockage of preformed TNF secretion. LPS-induced TNF exocytosis in BMMCs was dependent on tetanus toxin-insensitive vesicle-associated membrane proteins and calcium mobilization, as well as PI3K, MAPK, and IκB kinase (IKK) activation. TNF secretion was also associated to the phosphorylation of synaptosomal-associated protein 23 (SNAP-23), which was found forming a complex with IKK in LPS-activated BMMCs. Morphine pretreatment prevented TLR4-dependent ERK and IKK phosphorylation. Analyzing the signaling events upstream of IKK activation, we found diminished TGF-β-activated kinase 1 (TAK1) phosphorylation and TNFR-associated factor (TRAF) 6 ubiquitination in BMMCs pretreated with morphine and stimulated with LPS. Morphine pretreatment provoked a marked increase in the formation of a molecular complex composed of TRAF6 and β-arrestin-2. Naloxone and a combination of μ and δ opioid receptor antagonists prevented morphine inhibitory actions. In conclusion, our results show that activation of μ and δ opioid receptors with morphine suppresses TLR4-induced TNF release in mast cells, preventing the IKK-dependent phosphorylation of SNAP-23, which is necessary for TNF exocytosis, and this inhibition correlates with the formation of a β-arrestin-2/TRAF6 complex. To our knowledge, these findings constitute the first evidence of molecular crosstalk between opioid receptors and the TLR4 signal transduction system in mast cells.

Cytokine profiles in long-term smokers of opium (Taryak)

OBJECTIVES

There are few studies with conflicting results on the effects of in vivo administration of opioids on immune function. The aim of this study was to evaluate the serum levels of interferon (IFN)-γ, interleukin (IL)-4, IL-10, IL-17, and hs-C-reactive protein (hs-CRP) in opium smokers.

METHODS

The study was conducted between 44 male opium addicts and 44 controls aged 20 to 40 years. The control group was healthy individuals with no lifetime history of substance abuse. All the opium abusers were selected from those who had a history of use of opium, as a regular habit, at least for 1 year, with a daily opium dosage of not less than 2 g. Addicts known to abuse alcohol or other drugs were excluded. Serum samples were collected from all participants and tested for the cytokine and hs-CRP levels by ELISA (enzyme-linked immunosorbent assay) method. Statistical analysis was performed using the Student t test.

RESULTS

The mean serum levels of IFN-γ, IL-10, and IL-17 in the opium addicts were significantly higher than those observed in the control group. The mean concentration of serum IL-4 in opium addicts did not differ from that in the control group. Systemic IL-10 levels correlated positively and significantly with CRP in opium addicts.

CONCLUSIONS

Long-term, daily use of opium is associated with higher Th1 (IFN-γ), Tr1 (IL-10), and Th17 (IL-17) cytokines concentration in serum. Interferon-γ and IL-17 are involved in inducing and mediating proinflammatory responses. Our data suggest that an immunoregulatory response is occurring with the upregulation of IL-10.

Serum markers of inflammation and oxidative stress in chronic opium (Taryak) smokers

A relationship between the expression of inflammation markers, oxidative stress and opium use has not been clearly established. This study was done to determine serum high-sensitivity C-reactive protein (hs-CRP), quantity of C3 and C4 complement factors, immunoglobulins, nitric oxide (NO) and total antioxidant capacity (TAC) in opium smokers and non-drug-using control participants. The present study was done on 44 male opium smokers and 44 controls of the same sex and age (20-40 years). The control group was healthy individuals with no lifetime history of drug abuse or dependence. All of the opium abusers were selected from those who had a history of opium use, for at least one year, with a daily opium dosage not less than 2g. Addicts known to abuse alcohol or other drugs were excluded. Serum hs-CRP concentration was measured using ELISA method and serum C3, C4 and immunoglobulins concentration were determined by Single Radial Immunodiffusion (SRID) method. NO production was estimated through Griess reaction and TAC was assessed by Ferric Reducing/Antioxidant Power (FRAP) test. Serum hs-CRP, complement factors (C3 and C4) and FRAP levels were significantly higher in the opium smokers (8.93 ± 1.93; 138.47 ± 13.39; 68.79 ± 7.02 and 972.75 ± 11.55, respectively) relative to the control group (0.72 ± 0.09; 93.36 ± 8.73; 33.08 ± 7.39 and 761.95 ± 18.61, respectively). These results permit us to conclude that opium smokers indeed present with a low to moderate grade inflammation, which is defined by an increase in acute phase proteins.

Circulating brain microvascular endothelial cells (cBMECs) as potential biomarkers of the blood-brain barrier disorders caused by microbial and non-microbial factors

Despite aggressive research, central nervous system (CNS) disorders, including blood-brain barrier (BBB) injury caused by microbial infection, stroke, abused drugs [e.g., methamphetamine (METH) and nicotine], and other pathogenic insults, remain the world's leading cause of disabilities. In our previous work, we found that dysfunction of brain microvascular endothelial cells (BMECs), which are a major component of the BBB, could be caused by nicotine, meningitic pathogens and microbial factors, including HIV-1 virulence factors gp41 and gp120. One of the most challenging issues in this area is that there are no available cell-based biomarkers in peripheral blood for BBB disorders caused by microbial and non-microbial insults. To identify such cellular biomarkers for BBB injuries, our studies have shown that mice treated with nicotine, METH and gp120 resulted in increased blood levels of CD146+(endothelial marker)/S100B+ (brain marker) circulating BMECs (cBMECs) and CD133+[progenitor cell (PC) marker]/CD146+ endothelial PCs (EPCs), along with enhanced Evans blue and albumin extravasation into the brain. Nicotine and gp120 were able to significantly increase the serum levels of ubiquitin C-terminal hydrolase 1 (UCHL1) (a new BBB marker) as well as S100B in mice, which are correlated with the changes in cBMECs and EPCs. Nicotine- and meningitic E. coli K1-induced enhancement of cBMEC levels, leukocyte migration across the BBB and albumin extravasation into the brain were significantly reduced in alpha7 nAChR knockout mice, suggesting that this inflammatory regulator plays an important role in CNS inflammation and BBB disorders caused by microbial and non-microbial factors. These results demonstrated that cBMECs as well as EPCs may be used as potential cell-based biomarkers for indexing of BBB injury.

Substance abuse, HIV-1 and hepatitis

During the course of human immunodeficiency virus type 1 (HIV-1) disease, the virus has been shown to effectively escape the immune response with the subsequent establishment of latent viral reservoirs in specific cell populations within the peripheral blood (PB) and associated lymphoid tissues, bone marrow (BM), brain, and potentially other end organs. HIV-1, along with hepatitis B and C viruses (HBV and HCV), are known to share similar routes of transmission, including intravenous drug use, blood transfusions, sexual intercourse, and perinatal exposure. Substance abuse, including the use of opioids and cocaine, is a significant risk factor for exposure to HIV-1 and the development of acquired immune deficiency syndrome, as well as HBV and HCV exposure, infection, and disease. Thus, coinfection with HIV-1 and HBV or HCV is common and may be impacted by chronic substance abuse during the course of disease. HIV- 1 impacts the natural course of HBV and HCV infection by accelerating the progression of HBV/HCV-associated liver disease toward end-stage cirrhosis and quantitative depletion of the CD4+ T-cell compartment. HBV or HCV coinfection with HIV-1 is also associated with increased mortality when compared to either infection alone. This review focuses on the impact of substance abuse and coinfection with HBV and HCV in the PB, BM, and brain on the HIV-1 pathogenic process as it relates to viral pathogenesis, disease progression, and the associated immune response during the course of this complex interplay. The impact of HIV-1 and substance abuse on hepatitis virus-induced disease is also a focal point.

Isolating cognitive and neurologic HIV effects in substance-dependent, confounded cohorts: a pilot study

Controversy exists as to whether effects of HIV infection can be detected in the cognitive profiles of substance users, with methodological differences in degree of control for confounding factors a major contributor to empirical discrepancies. To address this shortcoming, we conducted a small but well-controlled study aimed at isolating HIV neurocognitive (NC) effects in a group of chronic substance users. Thirty HIV-negative substance users were individually matched to 30 HIV-positive substance users on relevant medical and demographic factors, including reading level and methadone therapy status. Results revealed that reading level, methadone maintenance therapy, and positive urine toxicology each exerted significant influence on NC function, and that HIV status was a significant predictor of learning and speeded processing after these control factors were considered. The HIV-positive group also displayed significantly more neurologically assessed motor impairment (p < .05), which was specifically related to impaired cognition in this group and independent of degree of immunocompromise. These data demonstrate the need for increased attention to clinical/demographic characteristics of groups under study. They also show that with applied methodological rigor, the deleterious effects of HIV on cognition can be parsed from substance use, even in small samples with chronic and active use histories.

Chronic alcohol exposure, infection, extended circulating white blood cells differentiated by flow cytometry and neutrophil CD64 expression: a prospective, descriptive study of critically ill medical patients

Background

A history of prolonged and excessive consumption of alcohol increases the risk for infections. The goal of this study was to investigate circulating white blood cells (WBC) differentiated by flow cytometry and neutrophil CD64 expression in excessive alcohol drinkers versus abstinent or moderate drinkers, and in those with or without infection, in medical patients admitted to the intensive care unit (ICU).

Methods

All patients admitted between September 2009 and March 2010 with an ICU-stay of 3 days or more were eligible for inclusion. Upon admission, hematological exams were conducted by flow cytometry.

Results

Overall, 281 adult were included, with 37% identified as at-risk drinkers. The only significant difference found in circulating WBC between at-risk and not-at-risk drinkers was a lower number of B lymphocytes in at-risk drinkers (P = 0.002). Four groups of patients were defined: not-at-risk drinkers with no infection (n = 66); not-at-risk drinkers with infection (n = 112); at-risk drinkers with no infection (n = 53); and at-risk drinkers with infection (n = 50). Whilst the presence of infection significantly reduced levels of noncytotoxic and cytotoxic T lymphocytes and significantly increased levels of CD16^– monocytes in not-at-risk drinkers, with variation related to infection severity, infection had no effect on any of the variables assessed in at-risk drinkers. Post-hoc comparisons showed that B-lymphocyte, noncytotoxic, and cytotoxic T lymphocyte and CD16^– counts in at-risk drinkers were similar to those in not-at-risk drinkers with infection and significantly lower than those in not-at-risk drinkers without infection. Neutrophil CD64 index varied significantly between groups, with variations related to infection, not previous alcohol consumption.

Conclusions

These results show that chronic alcohol exposure has an impact on the immune response to infection in critically ill medical patients. The absence of significant variations in circulating WBC seen in at-risk drinkers according to the severity of infection is suggestive of altered immune response.

Cocaine and HIV-1 interplay in CNS: cellular and molecular mechanisms

Although antiretrovirals are the mainstay of therapy against HIV infection, neurological complications associated with the virus continue to hamper quality of life of the infected individuals. Drugs of abuse in the infected individuals further fuel the epidemic. Epidemiological studies have demonstrated that abuse of cocaine resulted in acceleration of HIV infection and the progression of NeuroAIDS. Cocaine has not only been shown to play a crucial role in promoting virus replication, but also has diverse but often deleterious effects on various cell types of the CNS. In the neuronal system, cocaine exposure results in neuronal toxicity and also potentiates gp120-induced neurotoxicity. In the astroglia and microglia, cocaine exposure leads to up-regulation of pro-inflammatory mediators such as cytokines and chemokines. These in turn, can lead to neuroinflammation and transmission of toxic responses to the neurons. Additionally, cocaine exposure can also lead to leakiness of the blood-brain barrier that manifests as enhanced transmigraiton of leukocytes/monocytes into the CNS. Both in vitro and in vivo studies have provided valuable tools in exploring the role of cocaine in mediating HIV-associated neuropathogenesis. This review summarizes previous studies on the mechanism(s) underlying the interplay of cocaine and HIV as it relates to the CNS.

Incidence and risk factors of sternal wound infection at site of incision after open-heart surgery

OBJECTIVE

To identify the incidence of sternal wound infection and the risk factors before, during and after open-heart surgery in an Iranian critical care unit.

METHOD

A descriptive, analytic study investigating all open-heart surgery patients from March 2010 to March 2011, in terms of the incidence of sternal wound infection and the risk factors before, during, and after surgery. Patients were examined for signs of infection at the site of surgical incision on presentation to the ward, daily during their stay, and on discharge. The same investigator reviewed all wounds, every day.

RESULTS

The incidence of sternal wound infection was found to be 10%. Multivariate regression analysis identified the following risk factors: diabetes (OR: 0.439; 95%CI: 0.21-0.95; p=0.04), age (OR: 1.033; 95%CI: 1.003-1.064; p=0.03), hyperlipidaemia (OR: 1.008; 95%CI: 1.005-1.011; p<0.001), history of respiratory disorders ([COPD] OR: 2.952; 95%CI: 1.3-6.4; p=0.007), female gender (OR: 2.06; 95%CI: 1.40-3.03; p<0.008), and history of addiction to opiates (OR: 2.33; 95%CI: 1.56-3.49; p<0.006).

CONCLUSION

This study found a high rate of surgical sternal wound infection in open-heart surgery patients in an Iranian critical care unit, suggesting that the medical and care-giving team in the cardiac intensive care unit need further education.

DECLARATION OF INTEREST

There were no external sources of funding for this study. The authors have no conflicts of interest to declare.

Vitamin D receptor activation and downregulation of renin-angiotensin system attenuate morphine-induced T cell apoptosis

Opiates have been reported to induce T cell loss. We evaluated the role of vitamin D receptor (VDR) and the activation of the renin-angiotensin system (RAS) in morphine-induced T cell loss. Morphine-treated human T cells displayed downregulation of VDR and the activation of the RAS. On the other hand, a VDR agonist (EB1089) enhanced T cell VDR expression both under basal and morphine-stimulated states. Since T cells with silenced VDR displayed the activation of the RAS, whereas activation of the VDR was associated with downregulation of the RAS, it appears that morphine-induced T cell RAS activation was dependent on the VDR status. Morphine enhanced reactive oxygen species (ROS) generation in a dose-dependent manner. Naltrexone (an opiate receptor antagonist) inhibited morphine-induced ROS generation and thus, suggested the role of opiate receptors in T cell ROS generation. The activation of VDR as well as blockade of ANG II (by losartan, an AT(1) receptor blocker) also inhibited morphine-induced T cell ROS generation. Morphine not only induced double-strand breaks (DSBs) in T cells but also attenuated DNA repair response, whereas activation of VDR not only inhibited morphine-induced DSBs but also enhanced DNA repair. Morphine promoted T cell apoptosis; however, this effect of morphine was inhibited by blockade of opiate receptors, activation of the VDR, and blockade of the RAS. These findings indicate that morphine-induced T cell apoptosis is mediated through ROS generation in response to morphine-induced downregulation of VDR and associated activation of the RAS.

Morphine induces splenocyte trafficking into the CNS

Opioids significantly alter functional responses of lymphocytes following activation. The opiate Morphine, alters the Th1 to Th2 response and modulates functional responses such as cytolytic activity and T-cell proliferation. Although there has been extensive research involving morphine's effects on lymphocytes, little is known about the effects morphine has on lymphocyte trafficking. The objective of the study was to use in vivo bioluminescent imaging to determine morphine's effect on the trafficking pattern of splenocytes systemically and into the CNS either in a naïve state or following a neuroinflammatory stimulus. A neuroinflammatory response was induced by intracerebrally administering a DNA IFN-γ DNA plasmid into morphine-dependent or placebo wildtype mice. Mice with or without a neurostimulus received adoptively transferred firefly luciferase transgenic splenocytes and imaged. Morphine dependence significantly altered the inherent ability of splenocytes to traffic into the spleen, and lead to non-directed chaotic trafficking throughout the animal, including into the CNS. The morphine-mediated effects on trafficking were blocked by the antagonist naltrexone. Morphine dependence intensified splenocyte infiltration into the CNS following neuroinflammation induced by IFN-γ gene transfer. The study precented determined that morphine severely altered the ability of non-activated splenocytes to home to the spleen, inducing extrasplenic trafficking thoughout the animal. In addition to altering the ability of naive splenocyte to traffic to the spleen, this study demonstrated that morphine profoundly exacerbated lymphocyte infiltration into the CNS following a neurostimulus.

Rodent models of HAND and drug abuse: exogenous administration of viral protein(s) and cocaine

Humans and chimpanzees are the natural hosts for HIV. Non-human primate models of SIV/SHIV infection in rhesus, cynomologus and pigtail macaques have been used extensively as excellent model systems for pathogenesis and vaccine studies. However, owing to the variability of disease progression in infected macaques, a phenomenon identical to humans, coupled with their prohibitive costs, there exists a critical need for the development of small-animal models in which to study the untoward effects of HIV-1 infection. Owing to the fact that rodents are not the natural permissive hosts for lentiviral infection, development of small animal models for studying virus infection has used strategies that circumvent the steps of viral entry and infection. Such strategies involve overexpression of toxic viral proteins, SCID mice engrafted with the human PBLs or macrophages, and EcoHIV chimeric virus wherein the gp120 of HIV-1 was replaced with the gp80 of the ecotropic murine leukemia virus. Additional strategy that is often used by investigators to study the toxic effect of viral proteins involves direct stereotactic injection of the viral protein(s) into specific brain regions. The present report is a compilation of the applications of direct administration of Tat into the striatum to mimic the effects of the viral neurotoxin in the CNS. Added advantage of this model is that it is also amenable to repeated intraperitoneal cocaine injections, thereby allowing the study of the additive/synergistic effects of both the viral protein and cocaine. Such a model system recapitulates aspects of HAND in the context of drug abuse.

Legalization, decriminalization & medicinal use of cannabis: a scientific and public health perspective

Empirical and clinical studies clearly demonstrate significant adverse effects of cannabis smoking on physical and mental health as well as its interference with social and occupational functioning. These negative data far outweigh a few documented benefits for a limited set of medical indications, for which safe and effective alternative treatments are readily available. If there is any medical role for cannabinoid drugs, it lies with chemically defined compounds, not with unprocessed cannabis plant. Legalization or medical use of smoked cannabis is likely to impose significant public health risks, including an increased risk of schizophrenia, psychosis, and other forms of substance use disorders.

Morphine suppresses IFN signaling pathway and enhances AIDS virus infection

BACKGROUND

Opioids exert a profound influence on immunomodulation and enhance HIV infection and replication. However, the mechanism(s) of their action remains to be determined. We thus investigated the impact of morphine on the intracellular innate antiviral immunity.

METHODOLOGY/PRINCIPAL FINDINGS

Seven-day-cultured macrophages were infected with equal amounts of cell-free HIV Bal or SIV Delta(B670) for 2 h at 37°C after 24 h of treatment with or without morphine. Effect of morphine on HIV/SIV infection and replication was evaluated by HIV/SIV RT activity assay and indirect immunofluorescence for HIV p24 or SIV p28 antigen. The mRNA expression of cellular factors suppressed or induced by morphine treatment was analyzed by the real-time RT-PCR. We demonstrated that morphine treatment of human blood monocyte-derived macrophages significantly inhibited the expression of interferons (IFN-α, IFN-β and IFN-λ) and IFN-inducible genes (APOBEC3C/3F/3G and 3H). The further experiments showed that morphine suppressed the expression of several key elements (RIG-I and IRF-7) in IFN signaling pathway. In addition, morphine treatment induced the expression of suppressor of cytokine signaling protein-1, 2, 3 (SOCS-1, 2, 3) and protein inhibitors of activated STAT-1, 3, X, Y (PIAS-1, 3, X, Y), the key negative regulators of IFN signaling pathway.

CONCLUSIONS

These findings indicate that morphine impairs intracellular innate antiviral mechanism(s) in macrophages, contributing to cell susceptibility to AIDS virus infection.

Determinants of newly detected human papillomavirus infection in HIV-infected and HIV-uninfected injection drug using women

BACKGROUND

We sought to identify factors associated with newly detected human papillomavirus (HPV) infection in a high-risk cohort of injection drug using women in Baltimore, MD.

METHODS

We studied 146 HIV-infected and 73 HIV-uninfected female participants in a 5-year prospective HIV natural history study. We examined the association of sexual and nonsexual risk factors and newly detected type-specific HPV infection as determined by consensus PCR between consecutive visits.

RESULTS

Newly detected HPV was more common among HIV-infected versus HIV-uninfected women (30% and 6%, respectively; P <0.01). Among the entire cohort, recent crack use (OR, 1.7; 95% CI, 1.1-2.6) and HIV infection/CD4 cell count were independent predictors for new HPV detection (HIV-uninfected as reference, OR, 4.6; 95% CI, 2.3-8.9, OR, 5.4; 95% CI, 2.8-10.3, and OR, 10.9; 95% CI, 5.5-21.7 for HIV-infected CD4 >500, 200-500, and <200, respectively). Among HIV-uninfected women, recent marijuana use was an independent predictor of newly detected HPV infection (OR, 3.5; 95% CI, 1.3-9.5).

CONCLUSIONS

Newly detected HPV clearly increased with greater immunosuppression in HIV-infected injection drug users. Larger studies of HIV-uninfected and infected high-risk individuals are needed to clarify the independent associations of crack and marijuana use with new (or reactivated) HPV infection.

Withdrawal from morphine reduces cell-mediated immunity against herpes simplex virus generated by natural immunization

In a previous study, the authors have shown that herpes simplex virus type 1 (HSV-1) glycoprotein B DNA vaccine but not live vaccine (non-virulent KOS strain) failed to induce protective immunity against acute HSV-1 challenge in morphine-dependent mice. The present study reports the effect of morphine withdrawal on protective immunity induced by live HSV-1 immunization. BALB/c mice were vaccinated with KOS strain as a live vaccine. Three weeks later, they were exposed to morphine for 14 days. On day 14, withdrawal was induced by administration of normal saline instead of morphine. One day later, immune responses against HSV-1 were assessed by measuring cytotoxicity, lymphocyte proliferation and interferon-γ production. Protection against HSV-1 was assessed by measuring the mortality rate after acute HSV-1 challenge. The results showed that withdrawal from morphine reduces protective immunity against acute HSV-1 challenge. These findings raise the possibility that withdrawal from morphine may increase the susceptibility of drug addicts to infectious diseases.

Alcohol consumption and the intention to engage in unprotected sex: systematic review and meta-analysis of experimental studies

AIMS

To review and analyse in experimentally controlled studies the impact of alcohol consumption on intentions to engage in unprotected sex. To draw conclusions with respect to the question of whether alcohol has an independent effect on the incidence of human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs).

METHODS

A systematic review and meta-analysis of randomized controlled studies examined the association between blood alcohol content (BAC) and self-perceived likelihood of using a condom during intercourse. The systematic review and meta-analysis were conducted according to internationally standardized protocols (Preferred Reporting Items for Systematic Reviews and Meta-Analyses: PRISMA). The meta-analysis included an estimate of the dose-response effect, tests for publication bias and sensitivity analyses.

RESULTS

Of the 12 studies included in the quantitative synthesis, our pooled analysis indicated that an increase in BAC of 0.1 mg/ml resulted in an increase of 5.0% (95% CI: 2.8-7.1%) in the indicated likelihood (indicated by a Likert scale) of engaging in unprotected sex. After adjusting for potential publication bias, this estimate dropped to 2.9% (95% CI: 2.0-3.9%). Thus, the larger the alcohol intake and the subsequent level of BAC, the higher the intentions to engage in unsafe sex. The main results were homogeneous, persisted in sensitivity analyses and after correction for publication bias.

CONCLUSIONS

Alcohol use is an independent risk factor for intentions to engage in unprotected sex, and as risky sex intentions have been shown to be linked to actual risk behavior, the role of alcohol consumption in the transmission of HIV and other STIs may be of public health importance.

Recruitment of α7 nicotinic acetylcholine receptor to caveolin-1-enriched lipid rafts is required for nicotine-enhanced Escherichia coli K1 entry into brain endothelial cells

AIM

We investigate how the α7 nicotinic acetylcholine receptor (α7 nAChR), an essential regulator of inflammation, contributes to the α7 agonist nicotine-enhanced Escherichia coli K1 invasion of human brain microvascular endothelial cells (HBMECs) through lipid rafts/caveolae-mediated signaling.

MATERIALS & METHODS

α7 nAChR-mediated signaling and bacterial invasion were defined by lipid raft fractionation, immunofluorescence microscopy and siRNA knockdown.

RESULTS

Nicotine-enhanced bacterial invasion was dose-dependently inhibited by two raft-disrupting agents, nystatin and filipin. Significant accumulation of the lipid raft marker GM3 was observed in HBMEC induced by E. coli K1 and nicotine. The recruitment of α7 nAChR and related signaling molecules, including vimentin, and Erk1/2, to caveolin-1 enriched lipid rafts was increased upon treatment with E44 or E44 plus nicotine. Erk1/2 activation (phosphorylation), which is required for α7 nAChR-mediated signaling and E44 invasion, was associated with lipid rafts and nicotine-enhanced bacterial infection. Furthermore, E44 invasion, E44/nicotine-induced activation of Erk1/2 and clustering of α7 nAChR and caveolin-1 was specifically blocked by both siRNAs.

CONCLUSION

α7 nAChR-mediated signaling through lipid rafts/caveolae is required for nicotine-enhanced E. coli K1 invasion of HBMEC.