The role of sex in daily levels of high-risk alcohol and cannabis co-use

Background

Co-use of alcohol and cannabis is highly prevalent and may be associated with negative outcomes. The intersection between alcohol and cannabis use remains poorly understood. The present study assessed this intersection and the moderating effects of sex on the daily levels of high-risk alcohol and cannabis co-use.

Methods

A secondary analysis of an experimental pharmacology study specifically designed to recruit individuals using both alcohol and cannabis was conducted. Thirty-three non-treatment seeking subjects (19 M/14F) reporting high-risk levels of alcohol and cannabis use completed a 30-day Timeline Follow-back (TLFB) assessment for alcohol and cannabis use, resulting in a total of N = 990 observations. Logistic models tested the probability of same day cannabis use as predicted by alcohol use (any use, total drinking, and binge drinking), sex, and alcohol use by sex interactions.

Results

Drinking any alcohol on a given day was associated with a significant increase in the likelihood of same-day cannabis use (b = 0.61, p = 0.001) as was amount of alcohol consumed on a given day (b = 0.083, p = 0.012). These relations were significantly moderated by sex (b = 1.58, p<0.001; b = 0.14, p = 0.044). Male-identifying individuals demonstrated an increased probability of concurrent cannabis use with any alcohol use on a given day, and this relationship increased linearly as the number of drinks consumed increased.

Conclusions

The present study investigated the patterns associated with co-using alcohol and cannabis in individuals reporting high-risk levels of both alcohol and cannabis use. The sex-dependent findings suggest that males are at higher risk for co-using alcohol and cannabis compared with females.

Cross-substance primed and cue-induced craving among alcohol and cannabis co-users: An experimental psychopharmacology approach

Co-use of alcohol and cannabis is highly prevalent and often problematic. However, mechanisms underlying their co-use remain unclear. This randomized and crossover study tests cross-substance subjective craving for alcohol and cannabis. A community sample of nontreatment-seeking alcohol and cannabis co-users (N = 30 completers, 40% female) reporting high-risk levels of alcohol and cannabis use completed two experimental sessions in their homes and were monitored remotely using internet meeting technology (i.e., Zoom). The two counterbalanced and randomized sessions were as follows: (a) consumption of a standard alcoholic beverage followed by cannabis cue exposure and (b) consumption (i.e., smoking) of a miniature cannabis cigarette (containing 18%-22% tetrahydrocannabinol), followed by alcohol cue exposure. Participants rated their subjective craving for both alcohol and cannabis at baseline, following alcohol/cannabis administration, and following the presentation of cross-substance-related cues. Repeated measures analysis of variances revealed a statistically significant difference in cannabis craving across time, such that craving for cannabis was significantly higher following cannabis cue reactivity, compared to baseline and following alcohol administration (p's < .001). Similarly, there was a statistically significant difference in alcohol craving across time, such that craving for alcohol was significantly higher following alcohol cue reactivity, compared to baseline and following cannabis administration (p's < .001). Overall, results suggest that individuals who co-use alcohol and cannabis are most sensitive to the cue-induced, rather than the pharmacologically induced effects, of substance administration on cross-substance craving. This pattern of findings does not support a complementarity model. Conversely, these results may be interpreted as indicative of a substitution model for alcohol and cannabis co-use. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Global sleep quality is associated with tonic craving, but not cue-induced craving

OBJECTIVE

Sleep disturbance is widespread among individuals with alcohol use disorder (AUD) and is thought to reduce the capacity for self-regulation. The present study examines how sleep disturbance is associated with the regulation of tonic (i.e., "trait-like") and cue-induced (i.e., "provoked") craving, among individuals with AUD.

METHODS

Participants with an AUD (N = 58) completed the Pittsburgh Sleep Quality Index (PSQI) for sleep quality, the Obsessive-Compulsive Drinking Scale (OCDS) for tonic craving, and the Alcohol Urge Questionnaire (AUQ) for cue-induced craving during an alcohol cue-exposure paradigm. A series of hierarchical regressions examined the independent contribution of sleep quality to tonic and cue-induced alcohol craving.

RESULTS

PSQI global score was associated with tonic craving per the OCDS, over and above alcohol use and demographic measures. PSQI global score was not associated with cue-induced craving.

CONCLUSION

These findings suggest that sleep dysfunction plays a role in tonic alcohol craving and that the underlying mechanism may be the reduction of self-regulation. Treatments targeting sleep dysfunction in AUD may prove useful in reducing craving and overall alcohol use.

Additive roles of tobacco and cannabis co-use in relation to delay discounting in a sample of heavy drinkers

RATIONALE

Alcohol use disorder (AUD) is associated with steeper delay discounting rates; however, it is unknown whether substance co-use, particularly cannabis use, has an additive effect on discounting rates among heavy drinkers. Furthermore, it is unclear whether substance co-use and delay discounting are independently associated with AUD severity.

OBJECTIVES

The purpose of this study was to determine whether alcohol, tobacco, and cannabis co-use impacts delay discounting rates. We also sought to determine whether substance co-use and delay discounting were associated with AUD symptom counts.

METHODS

The study sample was culled from several human laboratory studies and consisted of 483 heavy drinking individuals who completed a baseline visit (prior to experimental procedures). Participants were divided into groups based on self-reported alcohol, tobacco, and cannabis use during the past 30 days: alcohol only (n = 184), alcohol + cigarettes (n = 89), alcohol + cannabis (n = 82), and tri-use (n = 128). We examined discounting rates across the 4 groups and used multiple linear regression to test whether co-use and delay discounting were associated with AUD symptoms.

RESULTS

After adjusting for covariates, individuals in the alcohol + cannabis group and the tri-use group had steeper discounting rates relative to the alcohol-only group. In addition, tri-use and delay discounting rates were independently correlated with a greater number of AUD symptoms.

CONCLUSIONS

Delay discounting rates were significantly greater among subgroups reporting cannabis use providing partial support for an additive effect, while also highlighting the importance of co-use substance type. Both tri-use and delay discounting were associated with greater AUD severity, which may provide relevant intervention targets.

Promising outcomes from a cognitive behavioral therapy text-messaging intervention targeting drug use, antiretroviral therapy adherence, and HIV risk behaviors among adults living with HIV and substance use disorders

BACKGROUND

To date, no studies have reported the use of text messaging to deliver cognitive behavioral therapy (CBT) to people living with HIV and substance use disorders.

OBJECTIVE

We developed and evaluated a 12-week, CBT-based text-messaging intervention (TXT-CBT) targeting drug use and adherence to antiretroviral therapy (ART) for adults with HIV and comorbid opioid and stimulant use disorders.

MATERIALS AND METHODS

Participants were randomly assigned to receive either TXT-CBT (n = 25) or an informational pamphlet (INFO) discussing substance use and medication adherence (n = 25). ART adherence, drug use, and HIV-risk behaviors were assessed at baseline, monthly during treatment, and treatment-end, and were compared between groups using a mixed-model repeated-measures analysis. Injection drug use was examined as a moderator of outcomes.

RESULTS

Relative to the INFO group, TXT-CBT participants evidenced increased ART adherence, measured by phone-based unannounced pill counts and biochemically by viral load and CD4 count. TXT-CBT participation was also associated with reductions in opioid use and HIV risk behaviors. While reductions in cocaine use were observed in the TXT-CBT group, relative to the INFO group, other stimulant use did not change. Among people who inject drugs, TXT-CBT produced increases in ART adherence and corresponding changes in viral load, relative to injection drug users in the control condition.

CONCLUSIONS

Findings demonstrated promising preliminary evidence for the efficacy of TXT-CBT in improving ART adherence and reducing drug use and HIV-risk behaviors among people with HIV infection and comorbid opioid and stimulant use disorders.

Sex-dependent effects of alcohol administration on the urge to use cannabis

Alcohol and cannabis couse is highly prevalent and associated with various negative consequences. The likelihood of same day couse is high, especially among men, however, underlying mechanisms to their couse and its sex-dependent nature remain poorly understood. This study aims to elucidate the effects of controlled alcohol administration on the urge to use cannabis and considers sex-dependent effects. A community sample of non-treatment-seeking heavy drinkers (N = 37, 46% female) reporting cannabis use in the past 6 months completed an alcohol administration paradigm. Participants rated their urge to use cannabis and drink alcohol at baseline and at rising levels of breath alcohol concentration (BrAC). Mixed model analyses examined the effects of BrAC, sex, and their interaction on craving for cannabis. The relationships across urge for cannabis, urge for alcohol, and subjective responses to alcohol were also tested. There was a significant BrAC × Sex interaction on the urge to use cannabis, such that males reported increases in the urge to use cannabis at rising BrACs but females did not. Urge for alcohol significantly predicted urge for cannabis across rising levels of BrAC and this relationship was stronger in males than in females. Lastly, stimulation, but not sedation, during alcohol administration was positively associated with the urge for cannabis. Overall, these results suggest that the pharmacological effects of alcohol on the urge to use cannabis are sex-dependent and that the stimulant effects of alcohol are associated with a higher urge for cannabis. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Understanding low treatment seeking rates for alcohol use disorder: A narrative review of the literature and opportunities for improvement

Despite a well-documented global burden of disease attributable to alcohol use disorder (AUD), treatment seeking rates remain low. In this qualitative literature review, we address treatment seeking for AUD from a host of perspectives and summarize the literature on key factors. First, we summarize the rates of alcohol treatment seeking across various epidemiological surveys, spanning decades. Second, we discuss the definition of treatment seeking and 'what' is typically considered formal treatment. Third, we consider timing and discuss 'when' individuals are most likely to seek treatment. Fourth, we review the literature on 'who' is most likely to seek treatment, including demographic and clinical correlates. Fifth, we address the critical question of 'why' so few people receive clinical services for AUD, relative to the number of individuals affected by the disorder, and review barriers to treatment seeking at the treatment- and person-levels of analysis. Finally, we identify opportunities to improve treatment seeking rates by focusing on tangible points of intervention. Specifically, we recommend a host of adaptations to models of care including efforts to make treatment more appealing across stages of AUD severity, accept a range of health-enhancing drinking goals as opposed to an abstinence-only model, educate providers and consumers about evidence-based behavioral and pharmacological treatments, and incentivize the delivery of evidence-based services.

Effect of alcohol, tobacco, and cannabis co-use on gray matter volume in heavy drinkers

OBJECTIVE

Alcohol, tobacco, and cannabis are the three most frequently used drugs in the United States and co-use is common. Alcohol, tobacco, and cannabis use has been separately associated with altered brain structure, and alcohol and tobacco co-use results in decreases in gray matter volume. Less is known about the effect of alcohol and cannabis co-use, and alcohol, tobacco, and cannabis tri-use. Therefore, this study examined the effect of co- and tri-use on gray matter volume, a measure of brain cell density, in heavy drinkers.

METHOD

Heavy drinkers (n = 237; 152m/85f; age = 32.52; white = 111; black = 28; Latino = 9; American Indian = 2; Pacific Islander = 4; Asian = 59; mixed = 15; other = 9) were classified into four groups based on their alcohol, tobacco, and cannabis use: alcohol only users (n = 70), alcohol and tobacco co-users (n = 90), alcohol and cannabis co-users (n = 35), and alcohol, tobacco, and cannabis tri-users (n = 42). All participants completed a structural MRI scan. Voxel-based morphometry was conducted to evaluate the effect of co-use on gray matter volume, with alcohol only users as the reference group. Age, sex, and scanner were included as covariates.

RESULTS

Alcohol and tobacco co-users had significantly decreased left orbitofrontal gray matter volume relative to alcohol only users (Cohen's d = .79). There were no differences in gray matter volume between the alcohol only and alcohol and cannabis co-users, or between the alcohol only and tri-user groups.

CONCLUSION

The additive effect of tobacco co-use on gray matter volumes in heavy drinkers was limited and localized. The effect of tri-use of alcohol, tobacco, and cannabis may have interacted, such that overlapping cannabis and tobacco use masked volume differences present in separate co-using groups. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

POS0985 DISEASE CONTROL PERCEPTION BY PHYSICIANS AND PATIENTS WITH ANKYLOSING SPONDYLITIS AND PSORIATIC ARTHRITIS IN REAL CLINICAL PRACTICE IN SPAIN: MIDAS STUDY RESULTS

Background:

There are few published data regarding physician’ and patient’ perception of the disease control for ankylosing spondylitis (AS) and psoriatic arthritis (PsA).

Objectives:

To evaluate the relationship between physician’ and patient’ disease control perception compared to clinical outcomes for controlled disease (BASDAI<4 in AS or DAPSA≤14 in PsA).

Methods:

MIDAS is an observational, non-interventional, cross-sectional, multicenter study. Patients ≥18 years with ≥6 months AS or PsA diagnosis according to ASAS and modified New York criteria or CASPAR criteria, respectively, undergoing treatment ≥3 months before inclusion. The endpoint of this analysis was the relationship between disease control perception by physicians and patients and disease control (BASDAI<4 in AS or DAPSA≤14 in PsA).

Results:

313 AS patients included: 75.7% male, 78.5% HLA-B*27+, a mean (SD) age of 50.4 (12.0) years, a mean (SD) disease duration of 15.5 (11.6) years and a mean (SD) CRP of 5.1 (8.2) mg/l. 313 PsA patients included: 54.3% male, 17.95% HLA-B*27+, a mean (SD) age of 54.1 (12.2) years, a mean (SD) disease duration of 10.5 (9.0) years and a mean (SD) CRP of 4.91 (7.3) mg/l. AS group: in 95.5% of AS patients with BASDAI<4, physician’s perception matched the clinical evaluation, while only 42.3% of the patients with BASDAI≥4 matched physician’s perception. Positive Predictive Value (PPV) was 75.1%, Negative Predictive Value (NPV) was 83.9% and precision was 76.7%. Patients perceived their own disease as controlled in 95.0% of cases with BASDAI scores <4 and as not controlled in 29.7% of cases with BASDAI score ≥4. PPV was 71.1%, NPV was 76.7% and precision was 71.9%. The same trend was observed when assessing disease control through ASDAS-CRP index. PsA group: in 96.2% of patients with DAPSA≤14, physician’s perception matched the clinical evaluation, while only 47.6% of patients with DAPSA>14 matched the physician’s perception. PPV was 73.1%, NPV was 89.6% and precision was 76.4%. Patients perceived their own disease as controlled in 93.5% of the cases with DAPSA scores ≤14 and as not controlled in 32.3% of the cases with DAPSA>14. PPV was 66.8%, NPV was 77.4% and precision was 68.4%. The same trend was observed when assessing disease control through the MDA criteria (Table 1).

Table 1.

Physician’s and patient’s perception of the disease control related to disease control variables in AS and PsA

Controlled disease by physician’s perception?Controlled disease by patient’s perception?Valid NYesN (%)NoN (%)Valid NYesN (%)NoN (%)ASDisease control(BASDAI)Controlled(BASDAI<4)202 (100%)193 (95.5%)9 (4.5%)202 (100%)192 (95.0%)10 (5.0%)Not controlled(BASDAI≥4)111 (100%)64 (57.7%)47 (42.3%)111 (100%)78 (70.3%)33 (29.7%)Disease activity(ASDAS-CRP)Inactive(ASDAS-CRP<1.3)92 (100%)90 (97.8%)2 (2.2%)92 (100%)91 (98.9%)1 (1.1%)Active(ASDAS-CRP≥1.3)221 (100%)167 (75.6%)54 (24.4%)221 (100%)179 (81.0%)42 (19.0%)PsADisease control(DAPSA)Controlled(DAPSA≤14)186 (100%)179 (96.2%)7 (3.8%)185 (100%)173 (93.5%)12 (6.5%)Not controlled(DAPSA>14)126 (100%)66 (52.4%)60 (47.6%)127 (100%)86 (67.7%)41 (32.3%)Active disease (MDA)Inactive(MDA criteria ≥5)161 (100%)154 (95.7%)7 (4.3%)160 (100%)152 (95.0%)8 (5.0%)Active(MDA criteria<5)151 (100%)91 (60.3%)60 (39.7%)152 (100%)107 (70.4%)45 (29.6%)

AS, ankylosing spondylitis; ASDAS-CRP, Ankylosing Spondylitis Disease Activity Score- C-reactive protein; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; DAPSA, Disease Activity in Psoriatic Arthritis; MDA, Minimal Disease Activity; PsA, psoriatic arthritis.

Conclusion:

A higher agreement between physician’s and patient’ perception with the current clinical evaluation was observed when patients were controlled. MiDAS study showed that in real clinical practice in Spain, physicians perceived more disease control than the patients

Acknowledgements:

We thank to MIDAS group investigators and patients included in the study.

Disclosure of Interests:

José Luis Pablos Speakers bureau: Janssen, Pfizer, Lilly, Novartis, Roche, Celgene, Bristol, Abbvie, Sanofi, Consultant of: Janssen, Pfizer, Lilly, Novartis, Roche, Celgene, Bristol, Abbvie, Sanofi, Gilead, Galápagos, Xavier Juanola Speakers bureau: Novartis, Abbvie, Pfizer, Lilly, Consultant of: Novartis, Lilly, Abbvie, Ceferino Barbazán Speakers bureau: Sanofi, Pfizer, Novartis, Amgen, Abbvie, Roche, Galápagos, Lilly, BMS, Biogen, UCB, Consultant of: Sanofi, Pfizer, Novartis, Amgen, Abbvie, Roche, Galápagos, Lilly, BMS, Biogen, UCB, María L. García Vivar Speakers bureau: Lilly, Novartis, Pfizer, Amgen, Bristol, Abbvie, Sanofi, Janssen and UCB, Consultant of: Lilly, Novartis, Pfizer, Amgen, Bristol, Abbvie, Sanofi, Janssen and UCB, Ana Cruz Valenciano Speakers bureau: Novartis, Consultant of: Novartis, Carlos Rodriguez-Lozano: None declared, Maria Estadella Employee of: I’m employed at Syneos Health providing services for Novartis., Ana Venegas Employee of: employee at Novartis, Cristina Sanabra Employee of: Novartis employee, Carlos Sastré Employee of: Novartis employee.

Executive function moderates naltrexone effects on methamphetamine-induced craving and subjective responses

Background: Emerging evidence suggests that opioid receptor antagonists, such as naltrexone, are effective pharmacotherapies for alcohol, opioid, and possibly stimulant use disorders. It is posited that naltrexone exerts its effects, in part, by increasing functional connectivity between neural reward circuitry and frontal systems implicated in executive function. Yet no studies had examined whether executive function moderates these effects. Objectives: This study examined whether a composite measure of executive function (EF) moderates the effect of naltrexone on craving for methamphetamine and subjective responses following infusion of the drug. Methods: Individuals with methamphetamine use disorder (N = 30; 27% female) completed baseline neurocognitive assessments of premorbid and executive function, and an executive function factor was computed. Participants then underwent a randomized, double-blind, cross-over study of titration with naltrexone and placebo. Participants then received a 30-mg intravenous methamphetamine infusion and completed subjective response questionnaires at 8 times in the 120 minutes post-infusion. Results: Multilevel mixed models indicated a significant EF × medication interaction, reflecting greater effects of naltrexone to decrease "desire to access the drug", "want more of the drug", "crave the drug", "feel drug effects" and "feel high" in participants with low EF compared to those with high EF (Bs = .36-1.29, SEs = .14-.17, ps<0.01). These effects remained significant after controlling for premorbid cognitive functioning, baseline responses to methamphetamine, severity of methamphetamine use, and methamphetamine-related functional problems. Conclusion: Naltrexone may be especially effective in methamphetamine-dependent individuals with low EF. Neuropsychological assessments may also provide predictive clinical utility not captured by traditional measures of substance use severity.

Inclusion of Cannabis Users in Alcohol Research Samples: Screening In, Screening Out, and Implications

BACKGROUND

Alcohol and cannabis are frequently co-used, as 20-50% of those who drink alcohol report co-using cannabis. This study is based on the argument that alcohol researchers should enroll cannabis users in human laboratory studies of alcohol use disorder (AUD) to strengthen generalizability. This study examines how heavy drinking cannabis users differ from non-cannabis using heavy drinkers.

METHODS

In a community sample of non-treatment-seeking heavy drinkers (n = 551, 35% female), cannabis users were identified through: (a) self-reported cannabis use in the past 6 months and (b) positive urine toxicology test for tetrahydrocannabinol (THC). Cannabis users, identified as described previously, were compared with non-cannabis users on demographic and clinical characteristics.

RESULTS

Those who endorsed cannabis use in the past 6 months reported more binge drinking days. Participants who tested positive for THC had higher Alcohol Use Disorder Identification Test scores and more binge drinking days. Younger age and being a tobacco smoker were associated with an increased likelihood of cannabis use in the past 6 months, whereas male gender and being a tobacco use were associated with a greater likelihood of testing positive for THC. Individuals with cannabis use disorder (CUD) endorsed more depression and anxiety and had higher AUD symptom counts than cannabis users without CUD.

CONCLUSIONS

The inclusion of cannabis users in AUD samples allows for increased clinical severity. Excluding cannabis users from AUD studies may limit representativeness and expend unnecessary study resources. Lastly, tobacco use may explain a large portion of the effects of cannabis use on sample characteristics.

SHORT SUMMARY

Alcohol and cannabis are frequently co-used substances. In a sample of non-treatment-seeking heavy drinkers (n = 551, 35% female), cannabis users reported higher alcohol use and higher likelihood of tobacco use than non-cannabis users. Including cannabis users in alcohol research studies will improve representativeness and likely increase clinical severity.

Alcohol Cue-Induced Ventral Striatum Activity Predicts Subsequent Alcohol Self-Administration

BACKGROUND

Human laboratory paradigms are a pillar in medication development for alcohol use disorders (AUD). Neuroimaging paradigms, in which individuals are exposed to cues that elicit neural correlates of alcohol craving (e.g., mesocorticolimbic activation), are increasingly utilized to test the effects of AUD medications. Elucidation of the translational effects of these neuroimaging paradigms on human laboratory paradigms, such as self-administration, is warranted. The current study is a secondary analysis examining whether alcohol cue-induced activation in the ventral striatum is predictive of subsequent alcohol self-administration in the laboratory.

METHODS

Non-treatment-seeking heavy drinkers of East Asian descent (n = 41) completed a randomized, placebo-controlled, double-blind, crossover experiment on the effects of naltrexone on neuroimaging and human laboratory paradigms. Participants completed 5 days of study medication (or placebo); on day 4, they completed a neuroimaging alcohol taste cue-reactivity task. On the following day (day 5), participants completed a 60-minute alcohol self-administration paradigm.

RESULTS

Multilevel Cox regressions indicated a significant effect of taste cue-elicited ventral striatum activation on latency to first drink, Wald χ²  = 2.88, p = 0.05, such that those with higher ventral striatum activation exhibited shorter latencies to consume their first drink. Similarly, ventral striatum activation was positively associated with total number of drinks consumed, F(1, 38) = 5.90, p = 0.02. These effects were significant after controlling for alcohol use severity, OPRM1 genotype, and medication. Other potential regions of interest (anterior cingulate, thalamus) were not predictive of self-administration outcomes.

CONCLUSIONS

Neuroimaging alcohol taste cue paradigms may be predictive of laboratory paradigms such as self-administration. Elucidation of the relationships among different paradigms will inform how these paradigms may be used synergistically in experimental medicine and medication development.

Reward, Relief and Habit Drinking: Initial Validation of a Brief Assessment Tool

AIMS

Alcohol use disorder is highly heterogeneous. One approach to understanding this heterogeneity is the identification of drinker subtypes. A candidate classification consists of reward and relief subtypes. The current study examines a novel self-report measure of reward, relief, and habit drinking for its clinical correlates and subjective response (SR) to alcohol administration.

METHODS

Non-treatment-seeking heavy drinkers (n = 140) completed the brief reward, relief, habit drinking scale (RRHDS). A subset of this sample (n = 67) completed an intravenous alcohol administration. Individuals were classified into drinker subtypes. A crowdsourced sample of heavy drinkers (n = 187) completed the RRHDS and a validated reward relief drinking scale to compare drinking classification results.

RESULTS

The majority of the sample was classified as reward drinkers (n = 100), with fewer classified as relief (n = 19) and habit (n = 21) drinkers. Relief and habit drinkers reported greater tonic alcohol craving compared to reward drinkers. Reward drinkers endorsed drinking for enhancement, while relief drinkers endorsed drinking for coping. Regarding the alcohol administration, the groups differed in negative mood, such that relief/habit drinkers reported a decrease in negative mood during alcohol administration, compared to reward drinkers. The follow-up crowdsourcing study found a 62% agreement in reward drinker classification between measures and replicated the tonic craving findings.

CONCLUSIONS

Our findings suggest that reward drinkers are dissociable from relief/habit drinkers using the brief measure. However, relief and habit drinkers were not successfully differentiated, which suggests that these constructs may overlap phenotypically. Notably, measures of dysphoric mood were better at detecting group differences than measures capturing alcohol's rewarding effects.

Preliminary Efficacy of a Cognitive Behavioral Therapy Text Messaging Intervention Targeting Alcohol Use and Antiretroviral Therapy Adherence: A Randomized Clinical Trial

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov, NCT02603471.

Comparing alcohol cue-reactivity in treatment-seekers versus non-treatment-seekers with alcohol use disorder

Background: Recent studies have examined the distinction between treatment-seekers and non-treatment-seekers with alcohol use disorder (AUD) with a focus on treatment development.Objectives: To advance our understanding of treatment-seeking in clinical research for AUD, this study compares treatment-seekers to non-treatment-seekers with AUD on alcohol cue-reactivity (CR).Methods: A community sample (N = 65, 40% female) of treatment-seeking (n = 32, 40.6% female) and non-treatment-seeking individuals (n = 33, 39.4% female) with a DSM-5 diagnosis of moderate-to-severe AUD completed a laboratory CR paradigm. Analyses compared the two groups on subjective alcohol craving, heart rate, and blood pressure after the presentation of water cues and alcohol cues.Results: Mixed-design analyses of variance revealed a main effect of treatment-seeking status (i.e., group; p = .02), such that treatment-seekers reported higher levels of subjective craving across both water (p = .04) and alcohol (p = .03) cue types. However, analyses did not support a group × cue type interaction effect (p = .9), indicating that treatment-seekers were not more cue-reactive. Group differences in craving were no longer significant when controlling for AUD severity. On blood pressure and heart rate, there was no significant effect of cue type, group, or cue type × group (p's > 0.13).Conclusion: These findings suggest that while treatment-seekers report higher levels of subjective craving than non-treatment-seekers, they are not more cue-reactive. Under the framework of medications development, we interpret these null findings to indicate that non-treatment seeking samples may be informative about CR and therefore, medication-induced effects on CR.

Naltrexone and alcohol effects on craving for cigarettes in heavy drinking smokers

Naltrexone has been extensively studied for the treatment of alcohol use disorder. However, less is known about the effects of naltrexone on smoking outcomes in the context of alcohol use among East Asian individuals who have been suggested to differ in response to alcohol and to naltrexone. The present study is a secondary analysis that used a double-blind placebo-controlled design (n = 31) to examine the (a) effects of alcohol on basal craving for cigarettes, (b) effects of naltrexone on cigarette craving and alcohol craving during alcohol administration, and (c) relationship between craving for alcohol and cigarettes. Heavy drinking smokers of East Asian descent completed two counterbalanced intravenous alcohol administration sessions, one after taking naltrexone (50 mg) for five days and one after taking a placebo for five days. Self-reported subjective craving for cigarettes and for alcohol was recorded during each experimental session. Craving for cigarettes and alcohol increased significantly throughout the intravenous alcohol administration. A significant breath alcohol concentration (BrAC) × Medication interaction revealed that naltrexone blunted cigarette craving during alcohol administration, compared to placebo. Naltrexone significantly reduced craving for alcohol during alcohol administration in this group of heavy drinking smokers. Alcohol craving significantly predicted cigarette craving, however this effect did not vary across rising alcohol administration or by medication. These findings demonstrate that naltrexone reduces the urge to smoke and to drink during alcohol administration. Clinical studies are needed to further ascertain whether naltrexone may be of benefit to this distinct subgroup of heavy drinking smokers. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The Interplay Between Subjective Response to Alcohol, Craving, and Alcohol Self-Administration in the Human Laboratory

BACKGROUND

Despite a rich literature on human laboratory paradigms of subjective response (SR) to alcohol, craving for alcohol, and alcohol self-administration, few studies have examined the interplay across these 3 constructs. The present study addresses this gap in the literature by examining the interplay between SR, craving, and self-administration in the human laboratory.

METHODS

Data were culled from a medication study (NCT02026011) in which heavy drinking participants of East Asian ancestry completed 2 double-blinded and counterbalanced experimental sessions. In each experimental session, participants received a priming dose of intravenous (IV) alcohol to a target breath alcohol concentration (BrAC) of 0.06 g/dl and measures of SR (stimulation and sedation) and alcohol craving were collected across rising BrACs. The IV alcohol challenge was immediately followed by a 1-hour alcohol self-administration period.

RESULTS

Mixed model analyses found a positive and significant relationship between the slope of stimulation and the slope of craving during the alcohol challenge. The relationship between sedation and craving, however, was not significant. The slope of craving during the alcohol challenge significantly predicted a higher number of mini-drinks consumed and lower latency to first drink. Further, mediation analyses found that craving was a significant mediator of the relationship between stimulation and total number of mini-drinks consumed, but the same pattern was not found for sedation.

CONCLUSIONS

Insofar as alcohol self-administration represents the end point of interest for a host of experimental and clinical research questions, the present study suggests that alcohol craving represents a more proximal predictor of self-administration than measures of alcohol-induced stimulation. It is recommended that human laboratory models interpret measures of SR and craving in light of their relative predictive utility for drinking outcomes.

State-of-the-art behavioral and pharmacological treatments for alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) and its associated consequences remain significant public health concerns. Given that AUD represents a spectrum of severity, treatment options represent a continuum of care, ranging from single-session brief interventions to more intensive, prolonged, and specialized treatment modalities.

OBJECTIVE

This qualitative literature review seeks to describe the best practices for AUD by placing a particular emphasis on identifying those practices which have received the most empirical support.

METHOD

This review summarizes psychological and pharmacological intervention options for AUD treatment, with a focus on the relapse prevention phase of recovery. Psychological and pharmacological treatments are summarized in terms of the empirical evidence favoring each approach and the level of AUD severity for which they are most indicated.

SCIENTIFIC SIGNIFICANCE

One of the broad assertions from this review is that while AUD is highly prevalent, seeking treatment for AUD is not. There are a myriad of behavioral and pharmacological treatments that have shown compelling evidence of efficacy for the treatment of AUD. In the behavioral treatment literature, cognitive behavioral therapy has received the most consistent support. Opioid antagonism (via naltrexone) has been the most widely studied pharmacotherapy and has produced moderate effect sizes. While none of the treatments reviewed herein represents a so-called silver bullet for AUD, they each have the potential to significantly improve the odds of recovery. Precision medicine, or the identification of best treatment matches for individual patients, looms as an important overarching goal for the field, although specific matches are not yet sufficiently reliable in their empirical evidence to warrant clinical dissemination.

Preliminary Outcomes of a Computerized CBT/MET Intervention for Depressed Cannabis Users in Psychiatry Care

Although depression is common among cannabis users, there is a paucity of targeted interventions addressing depression and cannabis use disorders concurrently. In the present pilot study, we examine the feasibility, acceptability, and preliminary outcomes of a computer-assisted intervention combining cognitive behavioral therapy (CBT) and motivational enhancement therapy (MET) techniques for adults with comorbid major depressive disorder (MDD) and cannabis use disorder (CUD) presenting for care in a psychiatric setting. Adults with MDD and CUD (N=26) recruited from mental health care settings were enrolled in a 10-week, computer-assisted psychosocial intervention: Self-Help for Alcohol and other Drug Use and Depression (SHADE). Feasibility, acceptability, perceived helpfulness, treatment retention, completion, and clinical outcomes including cannabis use and depression were assessed. Participants found the SHADE intervention to be acceptable and helpful in facilitating action towards their therapeutic goals concerning depression and cannabis use. Treatment completion, achieved by the majority (85%) of participants, was excellent. On average, participants reduced their past 30 day cannabis use from baseline (mean percentage of days using = 69%) to follow-up (M=44%) (t(22)= 2.3, p<0.05; Effect Size= 0.79). Concurrently, they evidenced reductions in depressive symptom severity, from the moderately severe range at baseline to the mild range at follow-up (t(24)=7.3, p<0.001; Effect Size=1.52). Addressing comorbid CUD and MDD using a computer-assisted, evidence-based treatment strategy is feasible in a psychiatric care setting, and may produce improvements in both depressive symptoms and cannabis use.

Barriers to initiation of extended release naltrexone among HIV-infected adults with alcohol use disorders

Alcohol consumption is a major risk factor for the acquisition of HIV/AIDS and is associated with greater disease burden and mortality among those who become HIV-infected. Of the extant pharmacological treatments for alcohol use disorders, naltrexone is recognized as one of the most efficacious, producing robust reductions in alcohol craving and use. Given that treatment with oral naltrexone has been limited by problems with adherence, which are particularly prevalent among individuals with multiple chronic, co-occurring conditions, long-acting formulations may be a promising approach for HIV-infected substance users. However, little is known about the barriers to initiation of extended-release naltrexone (XR-NTX) treatment among alcohol users living with HIV. In this report we present and discuss the content analysis of open-ended survey questions, as well as lessons learned, with regards to barriers to initiation and maintenance of XR-NTX treatment collected as part of an RCT evaluating a cognitive behavioral text messaging intervention for HIV-infected adults with alcohol use disorders. Barriers to initiation and maintenance of XR-NTX pharmacotherapy among HIV+ individuals with alcohol use disorders seem to fall in one of two categories: [1] barriers that are amenable to change, which include distance and transportation issues, fear of injections, and belief that alcohol use does not warrant pharmacotherapy, and [2] barriers that are not amenable to change, such as the potential interaction of XR-NTX with another medication regimen.

Effect of ageing on the availability of heavy metals in soils amended with compost and biochar: evaluation of changes in soil and amendment properties

Remediation strategies using soil amendments should consider the time dependence of metal availability to identify amendments that can sustainably reduce available pollutant concentrations over time. Drying-wetting cycles were applied on amendments, soils and soil + amendment mixtures, to mimic ageing at field level and investigate its effect on extractable Cd, Cu, Ni, Pb and Zn concentrations from three contaminated soils. The amendments investigated were municipal waste organic compost and biochars. The amendments, soils and mixtures were characterised by their physicochemical properties at different ageing times. The amendments were also characterised in terms of sorption capacity for Cd and Cu. The sorption capacity and the physicochemical properties of the amendments remained constant over the period examined. When mixed with the soils, amendments, especially the compost, immediately reduced the extractable metals in the soils with low pH and acid neutralisation capacity, due to the increase in pH and buffering capacity of the mixtures. The amendments had a relatively minor impact on the metal availability concentrations for the soil with substantially high acid neutralisation capacity. The most important changes in extractable metal concentrations were observed at the beginning of the experiments, ageing having a minor effect on metal concentrations when compared with the initial effect of amendments.

A Cognitive Behavioral Therapy-Based Text Messaging Intervention Versus Medical Management for HIV-Infected Substance Users: Study Protocol for a Pilot Randomized Trial

Background

Evidence-based psychosocial interventions for addictions and related conditions such as cognitive behavioral therapy (CBT) are underutilized. Obstacles to implementation of CBT in clinical settings include limited availability of quality training, supervision, and certification in CBT for clinicians; high rates of clinician turnover and high caseloads; and limited qualifications of the workforce to facilitate CBT expertise.

Objective

Mobile phone–based delivery of CBT, if demonstrated to be feasible and effective, could be transformative in broadening its application and improving the quality of addiction treatment. No experimental interventions that deliver CBT targeting both drug use and medication adherence using text messaging have been previously reported; as such, the objective of this study is to develop and test an SMS-based treatment program for HIV-positive adults with comorbid substance use disorders.

Methods

With user input, we developed a 12-week CBT-based text messaging intervention (TXT-CBT) targeting antiretroviral (ART) adherence, risk behaviors, and drug use in a population of HIV-infected substance users.

Results

The intervention has been developed and is presently being tested in a pilot randomized clinical trial. Results will be reported later this year.

Conclusions

This investigation will yield valuable knowledge about the utility of a cost-effective, readily deployable text messaging behavioral intervention for HIV-infected drug users.

Viability of organic wastes and biochars as amendments for the remediation of heavy metal-contaminated soils

Composts derived from municipal (MOW and MSW) and domestic wastes (DOM), wastes from the olive oil industry (OWH and OP), green waste (GW), and biochars (BF and BS) were investigated to test their viability for remediating metal-contaminated soils. In addition to common analyses, the characterisation included structural analyses (FTIR and (13)C NMR), determination of the acid neutralisation capacity (ANC) and the construction of sorption isotherms for target metals (Pb, Zn, Cd, Ni and Cu). MOW and GW had the highest ANC values (4280 and 7100 meq kg(-1), respectively), and MOW, GW, DOM, BF and BS exhibited the highest solid-liquid distribution coefficients (Kd) with maximum values in the 10(4) L kg(-1) range. Sorption isotherms were fitted using linear and Freundlich models for better comparison of the sorption capacities of the materials. Based on their basic pH, high ANC and high sorption capacity, MOW, GW and biochars are the most promising materials.

Arg113His mutation of vanishing white matter is not present in multiple sclerosis

Vanishing white matter (VWM) is a childhood leukoencephalopathy with central hypomyelination, white matter rarefaction, and cystic degeneration. Adult onset, variable phenotype, and high frequency characterize Arg113His mutation caused by G338A polymorphism associated with VWM. A patient with trauma-associated onset, and clinical features compatible with multiple sclerosis (MS), was homozygous for G338A mutation of eukaryotic translation initiation factor (eIF2B5). The authors checked a cohort of 101 MS patients, including 19 with head/neck trauma-associated onset, and failed to find the mutation, described above, in MS chromosomes. Our report does not exclude the presence in MS chromosomes of other mutations in the eIF2B gene family. Multiple Sclerosis 2007; 13: 424-427. http://msj.sagepub.com

Helicobacter pylori vacA s1a and s1b alleles from clinical isolates from different regions of Chile show a distinct geographic distribution

AIM

To establish the most common vacA alleles in Helicobacter pylori (H pylori) strains isolated from Chilean patients and its relationship with gastritis and gastroduodenal ulcers.

METHODS

Two hundred and forty five H pylori clinical isolates were obtained from 79 biopsies from Chilean infected patients suffering from gastrointestinal diseases. An average of 2-3 strains per patient was isolated and the vacA genotype was analyzed by PCR and 3% agarose electrophoresis. Some genotypes were checked by DNA sequencing.

RESULTS

The most prevalent vacA genotype in Chilean patients was s1b m1 (76%), followed by s1a m1 (21%). In contrast, the s2 m2 genotype was scarcely represented (3%). The s1b m1 genotype was found most frequently linked to gastropathies (P<0.05) rather than ulcers. Ulcers were found more commonly in male and older patients. Curiously, patients living in cities located North and far South of Santiago, the capital and largest Chilean city, carried almost exclusively strains with the s1b m1 genotype. In contrast, patients from Santiago and cities located South of Santiago carried strains with either one or both s1a m1 and s1b m1 genotypes. Regarding the s2 m2 genotype, comparison with GenBank sequences revealed that Chilean s2 sequence was identical to those of Australian, American, and Colombian strains but quite different from those of Alaska and India.

CONCLUSION

Differences in geographic distribution of the s and m vacA alleles in Chile and a relationship of s1b m1 genotype with gastritis were found. Sequence data in part support a hispanic origin for the vacA genotype. Asymmetric distribution of genotypes s1b m1 and s2 m2 recedes H Pylori strain distribution in Spain and Portugal.

Subset of hybrid eukaryotic proteins is exported by the type I secretion system of Erwinia chrysanthemi

Erwinia chrysanthemi exports degradative enzymes by using a type I protein secretion system. The proteases secreted by this system lack an N-terminal signal peptide but contain a C-terminal secretion signal. To explore the substrate specificity of this system, we have expressed the E. chrysanthemi transporter system (prtDEF genes) in Escherichia coli and tested the ability of this ABC transporter to export hybrid proteins carrying C-terminal fragments of E. chrysanthemi protease B. The C terminus contains six glycine-rich repeated motifs, followed by two repeats of the sequences DFLV and DIIV. Two types of hybrid proteins were assayed for transport, proteins with the 93-residue-protease-B C terminus containing one glycine-rich repeat and both hydrophobic terminal repeats and proteins with the 181-residue C terminus containing all repeat motifs. Although the shorter C terminus is unable to export the hybrids, the longer C terminus can promote the secretion of hybrid proteins with N termini as large as 424 amino acids, showing that the glycine-rich motifs are required for the efficient secretion of these hybrids. However, the secretion of hybrids occurs only if these proteins do not carry disulfide bonds in their mature structures. These latter results suggest that disulfide bond formation can occur prior to or during the secretion. Disulfide bonds may prevent type I secretion of hybrids. One simple hypothesis to explain these results is that the type I channel is too narrow to permit the export of proteins with secondary structures stabilized by disulfide bonds.

Chromogenic plate assay distinguishing bacteriolytic from bacteriostatic activity of an antibiotic agent

A solid agar plate assay was devised to discriminate bacteriolytic from bacteriostatic activity for a given antibacterial agent. The assay uses a bacterial culture harboring beta-galactosidase enzyme as reporter of cellular lysis. When a drop of bacteriolytic compound is placed on the agar, beta-galactosidase is released from the bacteria to the external solid medium where it hydrolyzes X-Gal substrate analogue, developing a blue halo at the edge of the inhibition growth zone. The assay was successfully evaluated against several antibiotics with well-known mechanism of action. It was found that bacteriostatic compounds consistently did not display blue halo at the inhibition zone.

Serological response to Helicobacter pylori recombinant antigens in Chilean infected patients with duodenal ulcer, non-ulcer dyspepsia and gastric cancer

We have previously cloned 10 Helicobacter pylori antigen genes from a Chilean strain including: cytotoxin VacA, a truncated region of CagA (called A17), a species-specific protein (Ag26), urease subunits (UreA, UreB), a flagellin, (FlaB), heat shock proteins (HspA and HspB), an adhesin (HpaA) and a lipoprotein (Lpp20). Immunogenicity of these antigens was tested by immunoblot with sera of Chilean infected patients, revealing that HpaA, A17, HspB and VacA were more frequently recognized (86%, 82%, 68% and 68%, respectively). According to the clinical condition, it was determined that Lpp20 was preferentially recognized by sera from non-ulcer dyspepsia patients (80%), A17 and VacA by patients with duodenal ulcer (92% and 83% respectively), and HspB by patients with duodenal ulcer (83%) and gastric cancer (90%). An ELISA was developed with a purified mixture of A17 and VacA antigens to test the different groups of patients. It was found that sera from duodenal ulcer patients showed higher values than those from non-ulcer dyspepsia patients, but this difference was not significant (p<0.2). Moreover, sera from gastric cancer patients showed values lower than those from non-ulcer dyspepsia patients (p<0.019). These results indicate that, in the Chilean population, antibodies raised against VacA and A 7 are not markers either for duodenal ulcer or for gastric cancer.

Varicocele-associated decrease in antioxidant defenses

Varicocele is associated with an oxidative stress condition. We have measured the antioxidant defenses of varicocele patients both at the local (seminal plasma) and systemic (blood plasma) levels. The antioxidant defenses, as evaluated by the total reactive antioxidant potential parameter, decrease both in the seminal (controls 676+/-128; patients = 386+/-186) and blood (controls = 519+/-63; patients = 268+/-110) plasma of varicocele patients. Compared with controls, patients with both normal spermiograms and spermiograms altered in motility or morphology demonstrated lower values. The results obtained suggest that varicocele-associated oxidative stress is evidenced both at the local and systemic levels. This conclusion is supported by results showing that urinary spontaneous chemiluminescence is also significantly increased in the patients.

Selective regulation of integrin--cytoskeleton interactions by the tyrosine kinase Src

Cell motility on extracellular-matrix (ECM) substrates depends on the regulated generation of force against the substrate through adhesion receptors known as integrins. Here we show that integrin-mediated traction forces can be selectively modulated by the tyrosine kinase Src. In Src-deficient fibroblasts, cell spreading on the ECM component vitronectin is inhibited, while the strengthening of linkages between integrin vitronectin receptors and the force-generating cytoskeleton in response to substrate rigidity is dramatically increased. In contrast, Src deficiency has no detectable effects on fibronectin-receptor function. Finally, truncated Src (lacking the kinase domain) co-localizes to focal-adhesion sites with alpha v but not with beta 1 integrins. These data are consistent with a selective, functional interaction between Src and the vitronectin receptor that acts at the integrin-cytoskeleton interface to regulate cell spreading and migration.

Construction of a gene encoding the insect bactericidal protein attacin. Studies on its expression in Escherichia coli

Attacin, a bactericidal small protein is produced by the giant silk moth Hyalophora cecropia. This paper deals with our efforts to clone the attacin cDNA in a bacterial vector to express it in Escherichia coli and produce the protein in sufficient amount, for further studies. We chose two inducible expression vector/bacterial cell systems: pPL-lambda/N99cI+ cells which is able to be induced by nalidixic acid, and pET3d/BL21(DE3) cells carrying a T7 RNA polymerase gene which is IPTG-inducible. After cloning in the pPL-lambda system and under no addition of the inducer, isolated transformants carried this plasmid with at least 2 concurrent deletions that drastically affected attacin expression, even though attacin gene seems to be intact as deduced by its PCR amplification. It was concluded that basal attacin expression occurred in this system and bacterial growth was limited. Plasmid deletions may have emerged by selection pressure as a way to avoid bactericidal expression and allow bacteria survival. The second cloning attempt was done in pET3d vector/BL21 cells, that should not express the cloned sequence (they lack T7 RNA polymerase gene). Transformed BL21 cells gave 3 recombinant plasmids, 2 of them presented a C deletion that generated an early stop signal in the attacin coding region. The third clone, pET-ATT18, carrying an intact gene, was transferred to BL21(DE3)-IPTG inducible cells in order to be expressed. Attacin was undetectable in stained gels or by Western blot analysis. However, expression was visualized in grown cells after 30 min of IPTG induction and 5 min of [35S]-methionine labeling, as a 22.5 kDa protein band by using gel electrophoresis and fluorography. This low level of expression drastically affected bacterial growth. Considering that attacin has no lytic activity, these results suggest that this molecule should block bacterial growth directly at the cytoplasm by an unknown mechanism, since no signal peptide coding sequence was incorporated in this gene construction, precluding periplasmic or external destination of this protein.

NMDA-NR1 receptor subunit mRNA expression in rat brain after 6-OH-dopamine induced lesions: a non-isotopic in situ hybridization study

Antisense digoxigenin-labeled deoxyoligonucleotides probes and non-isotopic in situ hybridization (HIS) techniques have been used to explore the NMDA-NR1 receptor subunit mRNA distribution in different brain areas of rats which had their dopaminergic nigrostriatal pathway previously lesioned with intracerebral administration of 6-OH-dopamine (6-OH-DA). Intense and significant hybridization signals for NR1 mRNA were found in dentate gyrus and regions CA1-CA2-CA3 of the hippocampus, in layers II-III and V-VI of the cerebral cortex, and in the cerebellum of sham-treated rats. Basal ganglia structures such as the striatum exhibited few NR1 mRNA hybridization signals as compared to the hippocampus and cerebral cortex. In contrast, both zona compacta and reticulata of substantia nigra (SN) showed a reduced number of cells with nevertheless intense NR1 mRNA HIS signals. The NR1 mRNA distribution in the brain was affected in a brain regional selective manner by 6-OH-DA induced lesions of DA neuronal systems. A striking increase in NR1 mRNA HIS signals was observed in both striata after unilateral lesioning with 6-OH-DA. Instead, in SN compacta but not in reticulata, a moderate but significant bilateral reduction of NR1 mRNA was observed after unilateral 6-OH-DA injection. No significant changes in NR1 mRNA were detected in cerebral cortex and other brain regions after 6-OH-DA treatment. These studies, and others reported in the literature, support the view that extensive lesions of nigrostriatal DA-containing neurons in the brain may trigger compensatory or adaptative responses in basal ganglia structures such as striatum and substantia nigra which involve glutamateric neurons and the genic expression of NMDA receptors.

Discrete transcripts encode multiple chitinase isoforms in Brugian microfilariae

The blood-borne microfilariae of the Brugian nematodes produce multiple isoforms of chitinase, whose expression is coincident with the onset of microfilarial infectivity for mosquitoes. A single cDNA sequence was previously obtained by screening a Brugia malayi microfilarial cDNA library, yet two chitinase isozymes are readily distinguished in this species. In this paper, we present evidence for the existence of multiple transcripts encoding Brugian microfilarial chitinases. Using primers based on the previously-sequenced cDNA clone, we amplified and sequenced two discrete products from B. malayi microfilarial RNA by RT-PCR. While the shorter fragment was nearly identical to the previously sequenced cDNA, the larger fragment contained an extra copy of a serine/threonine-rich repeat. RNAse protection assays were used to demonstrate that both sequences represent true transcripts, and not PCR artifacts. Using primers based on the B.malayi sequence, two novel sequences were generated by RT-PCR from B. pahangi microfilariae. Homologous and cross-species RNAse protection assays verified that multiple transcripts also encode chitinase isozymes in B. pahangi microfilariae.

Expression of recombinant microfilarial chitinase and analysis of domain function

A family of chitinase isozymes was previously characterized from the microfilariae of Brugia malayi and Brugia pahangi. The expression of these enzymes correlates with the onset of microfilarial infectivity for the mosquito vector. To study the role of chitinase activity in filarial transmission, the p70 chitinase from Brugia malayi was cloned and expressed in two forms: a full-length product of approximately 62 kDa and a truncated product of 43 kDa containing only the N-terminal catalytic domain. Two epitopes defined by monoclonal antibodies were preserved only in the full-length recombinant enzyme. It was found that deletion of the cysteine-rich C-terminal domain increased the yield of the recombinant expression product, and did not affect the K(m) for di- or trisaccharide substrates. However, affinity for high molecular weight chitin was specific to the full-length molecule, and is apparently mediated by the cysteine-rich domain, suggesting a role for this part of the protein in targeting the secreted enzyme to its substrate.

Rotavirus detection by dot blot hybridization assay using a non-radioactive synthetic oligodeoxynucleotide probe

A synthetic oligodeoxynucleotide of 40 nucleotides corresponding to nucleotides 33-72 of the gene coding for the viral protein VP7 of rotavirus, was used as a nucleic acid probe to develop a non-radioactive hybridization method for rotavirus detection. The probe was labelled at the 3' end with biotin-7-dATP. The sensitivity and specificity of the dot blot hybridization assay for rotavirus detection was evaluated with 303 stool specimens. The results indicate that the hybridization assay has a higher sensitivity than both PAGE and EIA. Among the rotavirus strains tested 37 different electropherotypes were found. The results suggest that rotavirus diagnosis by dot hybridization using a non-radioactive probe may become routine laboratory procedure because it is simple, highly specific and very sensitive.

[Isolation of transcription promoters from Thiobacillus ferrooxidans and T. acidophilus and its introduction by conjugation to T. intermedius]

The chemolithotrophic acidophilic bacteria, Thiobacillus ferrooxidans is considered as the most important microorganism in relation to copper and uranium bioleaching ability. Since T. ferrooxidans is a strict chemolithotrophic microorganism, its genetic manipulation is a very hard task. Until now, all efforts have been unsuccessful. Therefore, we decided to approach the problem in steps, trying initially to manipulate some T. ferrooxidans related strains. We chose Thiobacillus acidophilus that shares its habitat with T. ferrooxidans and Thiobacillus intermedius, for its heterotrophic nature that makes them easier to grow and suitable for heterologous conjugation. The main objective of this work was directed towards the isolation and characterization of transcription promoters from T. acidophilus and T. ferrooxidans genomic DNA. Four different promoters from T. acidophilus and four from T. ferrooxidans were isolated and sequenced. In order to test their functional capacity in bacterial systems different from E. coli, they were subcloned and transferred to other bacteria. One of these recombinant plasmids was successfully transferred to T. intermedius and from it to Ps. putida. The subcloned promoter was able to confer streptomycin resistance to Ps. putida.

[Synthesis and secretion of the surface antigen from hepatitis B virus in animal cell cultures]

Stable mammalian cell lines synthesizing and secreting Hepatitis B surface particles have been obtained through genetic engineering techniques. These particles show by electron microscopy a size of 22 nm, they are structurally and immunochemically similar to the particles present in the plasma from chronic hepatitis B patients. Therefore these particles are an excellent source for the preparation of a vaccine against the virus.

Molecular cloning and expression in E. coli of a Salmonella typhi porin gene

Immunoscreening of a Salmonella typhi cosmid library in E. coli allowed the detection of clones producing a 36 kDa porin from S. typhi. The gene is efficiently expressed in an E. coli porin-less mutant and the protein is exported to the outer membrane envelope. Two clones which markedly differ in their level of expression have been isolated.

The yeast tRNA(Phe) gene family: structures and transcriptional activities reveal member differences not explained by intragenic promoters

Several cloned members of the yeast tRNA(Phe) gene family were transcribed in vitro using a HeLa extract and a yeast extract. The optimum DNA concentration was determined and kinetic experiments were performed for each clone to compare transcription levels. Both extract systems were able to splice the intervening sequence, but only the yeast extract produced the mature product. Some genes were not transcribed with the homologous system while they were transcribed with the HeLa extract, suggesting a control mechanism that is not operating in the heterologous system. Competition experiments demonstrated that the intragenic promoters of the inactive genes were able to bind transcription factor(s), but not as efficiently as active genes. This binding was not so strong when using linear DNA and was dependent on the presence of the 3' intragenic control region. DNA sequencing and computer analysis indicated the presence of short conserved sequences upstream from the genes. These sequences, which are not related to the intragenic promoters, are direct repeats of part of the 3' coding region in those genes that are transcribed in the homologous system. The relevance of these sequences on homologous transcription in vitro remains to be established.

Nucleotide sequence of a yeast tRNAArg3A gene and its transcription in a homologous in vitro system

Twelve bacterial clones containing complementary sequences to yeast tRNAArg3 were isolated from a gene library. The size of the yeast BamHI inserts ranges from 5.4 to 10 MDa. There are at least 6 copies of this gene in different loci of the yeast genome. Insert from clone pYAT-3 was mapped, and the presence of a tRNAArg3A gene was confirmed by DNA sequence. The coding region is colinear with the transcriptional product. Unlike other reported tRNAArg3A genes, this one is not linked to a tRNAAsp gene. In vitro transcription using a yeast extract produces a transcript of 76 +/- 1 bases.

Isolation and structure of a yeast initiator tRNAmet gene

Sixteen bacterial clones containing yeast initiator tRNAmet genes have been isolated. The size of the BamHI fragments encoding these genes ranges from 4,000 to 23,000 base pairs. The nucleotide sequence of one member of this group has been determined. It has no intervening sequences.

Yeast tRNA3Leu gene transcribed and spliced in a HeLa cell extract

A cloned yeast tRNA3Leu gene containing a 33-base intervening sequence (IVS) is selectively transcribed by a soluble extract from HeLa cells. The 130-nucleotide tRNA3Leu precursor RNA formed is colinear with the gene and contains approximately 4 leader nucleotides and up to 9 trailer nucleotides. The IVS is accurately and efficiently removed by an endogenous HeLa excision-ligase activity to yield the spliced tRNA, the free IVS, and the half-tRNA intermediates. The splicing reaction occurs without prior 5' and 3' maturation of the precursor but, with this exception, this pattern of synthesis and subsequent maturation of the tRNA3Leu precursor conforms to the scheme for tRNA biosynthesis deduced for the xenopus system. Indeed, the two systems utilize similar or identical tRNA3Leu precursors. Our results stress the extraordinary conservation of tRNA biosynthesis in eukaryotes and demonstrate that a HeLa extract provides a useful system for investigating this process.