Structure of biomimetic casein micelles: Critical tests of the hydrophobic colloid and multivalent-binding models using recombinant deuterated and phosphorylated β-casein

Milk contains high concentrations of amyloidogenic casein proteins and is supersaturated with respect to crystalline calcium phosphates such as apatite. Nevertheless, the mammary gland normally remains unmineralized and free of amyloid. Unlike κ-casein, β- and αS-caseins are highly effective mineral chaperones that prevent ectopic and pathological calcification of the mammary gland. Milk invariably contains a mixture of two to five different caseins that act on each other as molecular chaperones. Instead of forming amyloid fibrils, several thousand caseins and hundreds of nanoclusters of amorphous calcium phosphate combine to form fuzzy complexes called casein micelles. To understand the biological functions of the casein micelle its structure needs to be understood better than at present. The location in micelles of the highly amyloidogenic κ-casein is disputed. In traditional hydrophobic colloid models, it, alone, forms a stabilizing surface coat that also determines the average size of the micelles. In the recent multivalent-binding model, κ-casein is present throughout the micelle, in intimate contact with the other caseins. To discriminate between these models, a range of biomimetic micelles was prepared using a fixed concentration of the mineral chaperone β-casein and nanoclusters of calcium phosphate, with variable concentrations of κ-casein. A biomimetic micelle was also prepared using a highly deuterated and in vivo phosphorylated recombinant β-casein with calcium phosphate and unlabelled κ-casein. Neutron and X-ray scattering experiments revealed that κ-casein is distributed throughout the micelle, in quantitative agreement with the multivalent-binding model but contrary to the hydrophobic colloid models.

Hospital admissions among patients with Comorbid Substance Use disorders: a secondary analysis of predictors from the NavSTAR Trial

BACKGROUND

Individuals with substance use disorders (SUDs) frequently use acute hospital services. The Navigation Services to Avoid Rehospitalization (NavSTAR) trial found that a patient navigation intervention for hospitalized patients with comorbid SUDs reduced subsequent inpatient admissions compared to treatment-as-usual (TAU).

METHODS

This secondary analysis extends previous findings from the NavSTAR trial by examining whether selected patient characteristics independently predicted hospital service utilization and moderated the effect of the NavSTAR intervention. Participants were 400 medical/surgical hospital patients with comorbid SUDs. We analyzed 30- and 90-day inpatient readmissions (one or more readmissions) and cumulative incidence of inpatient admissions through 12 months using multivariable logistic and negative binomial regression, respectively.

RESULTS

Consistent with primary findings and controlling for patient factors, NavSTAR participants were less likely than TAU participants to be readmitted within 30 (P = 0.001) and 90 (P = 0.03) days and had fewer total readmissions over 12 months (P = 0.008). Hospitalization in the previous year (P < 0.001) was associated with cumulative readmissions over 12 months, whereas Medicaid insurance (P = 0.03) and index diagnoses of infection (P = 0.001) and injuries, poisonings, or procedural complications (P = 0.004) were associated with fewer readmissions. None of the selected covariates moderated the effect of the NavSTAR intervention.

CONCLUSIONS

Previous findings showed that patient navigation could reduce repeat hospital admissions among patients with comorbid SUDs. Several patient factors were independently associated with readmission. Future research should investigate risk factors for hospital readmission among patients with comorbid SUDs to optimize interventions.

TRIAL REGISTRATION

NIH ClinicalTrials.gov NCT02599818, Registered November 9, 2015 https://classic.

CLINICALTRIALS

gov/ct2/show/NCT02599818 .

Hepatitis C in Black Individuals in the US: A Review

Importance

In the US, the prevalence of hepatitis C virus (HCV) is 1.8% among people who are Black and 0.8% among people who are not Black. Mortality rates due to HCV are 5.01/100 000 among people who are Black and 2.98/100 000 among people who are White.

Observations

While people of all races and ethnicities experienced increased rates of incident HCV between 2015 and 2021, Black individuals experienced the largest percentage increase of 0.3 to 1.4/100 000 (367%) compared with 1.8 to 2.7/100 000 among American Indian/Alaska Native (50%), 0.3 to 0.9/100 000 among Hispanic (200%), and 0.9 to 1.6/100 000 among White (78%) populations. Among 47 687 persons diagnosed with HCV in 2019-2020, including 37 877 (79%) covered by Medicaid (7666 Black and 24 374 White individuals), 23.5% of Black people and 23.7% of White people with Medicaid insurance initiated HCV treatment. Strategies to increase HCV screening include electronic health record prompts for universal HCV screening, which increased screening tests from 2052/month to 4169/month in an outpatient setting. Awareness of HCV status can be increased through point-of-care testing in community-based settings, which was associated with increased likelihood of receiving HCV test results compared with referral for testing off-site (69% on-site vs 19% off-site, P < .001). Access to HCV care can be facilitated by patient navigation, in which an individual is assigned to work with a patient to help them access care and treatments; this was associated with greater likelihood of HCV care access (odds ratio, 3.7 [95% CI, 2.9-4.8]) and treatment initiation within 6 months (odds ratio, 3.2 [95% CI, 2.3-4.2]) in a public health system providing health care to individuals regardless of their insurance status or ability to pay compared with usual care. Eliminating Medicaid's HCV treatment restrictions, including removal of a requirement for advanced fibrosis or a specialist prescriber, was associated with increased treatment rates from 2.4 persons per month to 72.3 persons per month in a retrospective study of 10 336 adults with HCV with no significant difference by race (526/1388 [37.8%] for Black vs 2706/8277 [32.6%] for White patients; adjusted odds ratio, 1.02 [95% CI, 0.8-1.3]).

Conclusions and Relevance

In the US, the prevalence of HCV is higher in people who are Black than in people who are not Black. Point-of-care HCV tests, patient navigation, electronic health record prompts, and unrestricted access to HCV treatment in community-based settings have potential to increase diagnosis and treatment of HCV and improve outcomes in people who are Black.

Implementing a peer-supported, integrated strategy for substance use disorder care in an outpatient infectious disease clinic is associated with improved patient outcomes

BACKGROUND

Substance use disorder (SUD) and infectious disease (ID) care integration may lead to improvements in SUD and ID outcomes. We assessed implementation of integrating peer-supported SUD care in an outpatient ID setting.

METHODS

In this implementation study, we describe REcovery in Specialty care Through medication and OutREach (RESTORE), a low-threshold SUD program implemented in a Baltimore outpatient ID clinic. Key program components were clinician training and support in SUD care, prescription of SUD treatment medications, and peer-based psychosocial support provided by peer recovery specialists. We assessed clinician adoption of RESTORE and compared patient outcomes from baseline to 6 months.

RESULTS

Between January 2019 and January 2022, the number of ID clinicians (N=61) who prescribed buprenorphine increased eightfold from 3 (5%) to 24 (39%). Of 258 ID patients referred to RESTORE, 182 (71%) engaged, 137 consented to study participation. Mean age in the study sample was 52.1 (SD=10.4), 63% were male, 84% were Black/African-American. Among 127 (93%) who completed 6-month follow-up, fewer participants reported illicit/non-prescribed opioid use in the past 30 days at follow-up (32%) compared to baseline (52%; p<0.001). Similar reductions were noted for cocaine use (47% to 34%; p=0.006), emergency department visits (23% to 9%; p=0.002), and inpatient hospitalizations (15% to 7%; p=0.025).

CONCLUSION

SUD care integration into an outpatient ID care setting using a peer-supported implementation strategy was adopted by clinicians and improved clinical outcomes for patients. This strategy is a promising approach to treating people with infectious diseases and SUD.

Synthesis of the Prototypical Cyclopropyl Dipeptide Mimic and Evaluation of Its Turn-Inducing Capability

The (+) and (-) enantiomers of a new turn-inducing cyclopropyl dipeptide mimic have been synthesized and evaluated. The mimic derives its turn-inducing capabilities solely from the cyclopropyl group and without the conformational biasing that would be provided by side-chain substituents. The mimic and peptide-mimic hybrids prepared from it have been studied using a combination of spectroscopic techniques (NMR, IR, and CD). The dipeptide mimic itself displays intramolecular hydrogen bonding in organic solvents, which differs from that observed in natural peptide turns. In contrast, more elaborate peptide-mimic hybrids exhibit hydrogen bonding characteristics that vary with solvent but are consistent with structures found in the tetrapeptide portion (i → i + 3) of a native β-turn.

Identification of diverse lipid-binding modes in the groove of zinc α2 glycoprotein reveals its functional versatility

ZAG is a multifunctional glycoprotein with a class I MHC-like protein fold and an α1-α2 lipid-binding groove. The intrinsic ZAG ligand is unknown. Our previous studies showed that ZAG binds the dansylated C₁₁ fatty acid, DAUDA, differently to the boron dipyrromethane C₁₆ fatty acid, C₁₆ -BODIPY. Here, the molecular basis for this difference was elucidated. Multi-wavelength analytical ultracentrifugation confirmed that DAUDA and C₁₆ -BODIPY individually bind to ZAG and compete for the same binding site. Molecular docking of lipid-binding in the structurally related Cluster of differentiation 1 proteins predicted nine conserved ligand contact residues in ZAG. Twelve mutants were accordingly created by alanine scanning site directed mutagenesis for characterisation. Mutation of Y12 caused ZAG to misfold. Mutation of K147, R157 and A158 abrogated C₁₆ -BODIPY but not DAUDA binding. L69 and T169 increased the fluorescence emission intensity of C₁₆ -BODIPY but not of DAUDA compared to wild-type ZAG and showed that C₁₆ -BODIPY binds close to T169 and L69. Distance measurements of the crystal structure revealed K147 forms a salt bridge with D83. A range of bioactive bulky lipids including phospholipids and sphingolipids displaced DAUDA from the ZAG binding site but unexpectedly did not displace C₁₆ -BODIPY. We conclude that the ZAG α1-α2 groove contains separate but overlapping sites for DAUDA and C₁₆ -BODIPY and is involved in binding to a bulkier and wider repertoire of lipids than previously reported. This work suggested that the in vivo activity of ZAG may be dictated by its lipid ligand.

Views of barriers and facilitators to continuing methadone treatment upon release from jail among people receiving patient navigation services

BACKGROUND

Patient navigation has potential for assisting patients who initiate methadone during pretrial detention to enter and remain in treatment following release, but we know little about participants' experiences with this service.

METHODS

This study drew a purposive sample of male and female participants (N = 17) from participants enrolled in a randomized trial of initiating methadone with vs. without patient navigation while in the Baltimore City Detention Center. The study interviewed participants in the community at 1 and 3 months following release and asked them about their experiences of reentry, methadone treatment continuation, drug use, and interactions with the patient navigator. The study recorded, transcribed, coded using Atlas.ti, and analyzed thematically the interviews.

RESULTS

Participants reported encountering four key challenges in the community: getting to treatment following release, assembling basic supports, managing criminal justice system demands, and staying in treatment. Participants' experiences of the patient navigator's support to address these challenges fell into six thematic groups: showing nonjudgmental caring and persistence, advocating within programs, brokering resources, managing interactions with the criminal justice system, balancing encouragement and self-determination, and offering genuine and familial-type support.

CONCLUSION

Nearly all participants appreciated the navigator's support and deemed it helpful. The previously reported randomized trial found that participants assigned to initiate methadone treatment with navigation had higher rates of receiving their first "guest" methadone dose in the community but did not have significantly different rates of treatment enrollment or of illicit opioid use compared to those assigned to begin methadone treatment without navigation. Treatment programs should work to improve retention and postrelease outcomes among this population.

HIV-Risk Behavior Among Adults with Opioid Use Disorder During 12 Months Following Pre-trial Detention: Results from a Randomized Trial of Methadone Treatment

This was a three group randomized clinical trial of interim methadone and patient navigation involving 225 pre-trial detainees with opioid use disorder in Baltimore. The HIV Risk Assessment Battery (RAB) was administered at baseline (in jail), and at 6 and 12 months post-release. Generalized linear mixed model analyses indicated the condition × time interaction effect failed to reach significance (ps > .05) for both the drug risk and sex risk subscale scores. Therefore, findings suggest that there were no intervention effects on drug or sex risk behaviors. However, increased use of cocaine at baseline was associated with increases in drug- (b = .04, SE = .02) and sex-risk (b = .01, SE = .003) behaviors. These results suggest that interventions targeting cocaine use among pre-trial detainees may serve as a means of reducing HIV risk associated with drug- and sex-risk behaviors.Clinical Trials Registration: Clinicaltrials.gov NCT02334215.

Randomized trial of methadone treatment of arrestees: 24-month post-release outcomes

BACKGROUND

We report on the 24-month post-release outcomes of arrestees with opioid use disorder (OUD) enrolled in a randomized trial comparing three treatment approaches initiated in jail.

METHODS

Adults (N = 225) receiving medically supervised withdrawal from opioids in the Baltimore Detention Center within a few days of arrest were randomly assigned to: (1) interim methadone treatment plus patient navigation (IM + PN) started in the Detention Center; (2) IM; or (3) Enhanced Treatment-as-Usual (ETAU) consisting of detoxification with methadone and referral to treatment in the community. Participants in both methadone conditions could transfer to standard methadone treatment following release. Participants were interviewed at baseline, and 1, 3, 6, 12, and 24 months post-release. Urine was drug tested at follow-up and official arrest records were obtained.

RESULTS

On an intention-to-treat basis, there were no significant differences among the three conditions over the 24-month post-release period in terms of opioid- or cocaine-positive urine test results or self-reported opioid or cocaine use, meeting opioid or cocaine use disorder criteria, self-reported criminal behavior, or the number of official arrests. There were 9 fatal overdoses, none occurring during methadone treatment, and 109 hospitalizations unrelated to the study.

CONCLUSIONS

Given the high morbidity and mortality found in this population of arrestees and costs to society associated with their health care utilization and continued crime and arrests, research aimed at finding more effective interventions should be continued.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02334215.

Cost and cost-effectiveness of interim methadone treatment and patient navigation initiated in jail

BACKGROUND

Individuals with opioid use disorder (OUD) who are released from pre-trial detention in jail have a high risk of opioid relapse. While several interventions for OUD initiated during incarceration have been studied, few have had an economic evaluation. As part of a three-group randomized trial, we estimated the cost and cost-effectiveness of a negative urine opioid test. Detainees were assigned to interim methadone (IM) in jail with continued methadone treatment post-release with and without 3 months of post-release patient navigation (PN) compared to an enhanced treatment-as-usual group.

METHODS

We implemented a micro-costing approach from the provider's perspective to estimate the cost per participant in jail and over the 12 months post-release from jail. Economic data included jail-based and community-based service utilization, self-reported healthcare utilization and justice system involvement, and administrative arrest records. Our outcome measure is the number of participants with a negative opioid urine test at their 12-month follow-up. We calculated incremental cost-effectiveness ratios (ICERs) for intervention costs only and costs from a societal perspective.

RESULTS

The average cost of providing patient navigation services per individual beginning in jail and continuing in the community was $283. We find that IM is dominated by ETAU and IM + PN. Per additional participant with a negative opioid urine test, the ICER for IM + PN including intervention costs only is $91 and $305 including societal costs.

CONCLUSIONS

IM + PN is almost certainly the cost-effective choice from both an intervention provider and societal perspective.

A Latent Class Analysis of HIV Risk Factors Among Men and Women with Opioid Use Disorder in Pre-trial Detention

Adults entering pre-trial detention who inject drugs are at high risk for acquiring HIV/AIDS. In the current study, we examined pre-incarceration HIV risk behaviors among 114 people with opioid use disorder who inject drugs. Participants were recruited from the Baltimore City Detention Center as part of a randomized controlled trial of pre-release methadone treatment. Using latent class analysis, we found three separate latent classes, which we identified as the sex exchange class (14.2%), drug equipment sharing class (36.8%) and lower risk class (49.0%). Women in the sex exchange class (n = 16) reported having multiple male partners and selling sex for money or drugs; however, this group also reported more consistent condom use and less frequent injection drug and equipment sharing than participants in the drug equipment sharing class. Our findings highlight distinct profiles of jail detainees with OUD based on their risks for HIV, and could inform more targeted interventions for each group.Clinical Trials Registration: Clinicaltrials.gov NCT02334215.

Impact of methadone treatment initiated in jail on subsequent arrest

BACKGROUND

There are limited data from randomized trials about the impact of starting methadone treatment in jail on subsequent arrest after release for adults with opioid use disorder (OUD).

METHODS

Official arrest records were obtained for 212 participants with OUD who were enrolled in a three-group randomized controlled trial of initiating methadone treatment in jail either with or without patient navigation vs. enhanced treatment-as-usual in Baltimore, Maryland. Participants treated for opioid withdrawal in jail were assigned to: 1) interim methadone (IM) with patient navigation (PN; IM + PN); 2) IM without PN (IM); or 3) enhanced treatment-as-usual (ETAU). Participants in both IM groups were able to continue treatment at a community-based methadone treatment program with counseling upon release, while ETAU participants received overdose information and a city-wide treatment assessment/referral number. Likelihood of arrest, time to first subsequent arrest, and severity of arrest charges in the 12 months following release were examined for: 1) combined IM + PN and IM groups compared to ETAU; and 2) IM + PN compared to IM.

RESULTS

Within 12 months of release from the index incarceration, 50.5% of the sample had been arrested. The majority of arrest charges (71%) were for low-level, nonviolent crimes. On an intention-to-treat basis, there were no significant differences between the combined IM + PN and IM groups vs. ETAU or IM + PN vs. IM in the likelihood of arrest, time to first subsequent arrest, or severity of arrest charges.

CONCLUSION

Initiating IM with or without PN during pretrial detention did not have a significant effect on subsequent arrest during a 12-month post-release follow-up compared to not starting methadone maintenance during detention, despite the high rate of methadone treatment entry in the community following release. This finding may be attributable to the considerable attrition from treatment in the community or other systematic factors. Additional interventions may be needed to reduce the likelihood of subsequent arrest.

Disclosure of Adolescent Substance Use in Primary Care: Comparison of Routine Clinical Screening and Anonymous Research Interviews

PURPOSE

The American Academy of Pediatrics recommends substance use screening in adolescent primary care. Many studies of substance use prevalence and screening tool validation are conducted under research protocols that differ from routine clinical screening in context, consequences, and privacy implications.

METHODS

This study is a secondary analysis drawing from two projects focused on adolescent primary care patients, aged 12-17, conducted nearly contemporaneously in a Federally Qualified Health Center system. The first project conducted anonymous research interviews with patients (N = 525), while the other tracked routine clinical screening as part of a larger service implementation project (N = 5,971). Both projects assessed substance use with the CRAFFT screening tool.

RESULTS

Rates of substance use disclosure and substance use problems were over three and four times higher, respectively, in the anonymous research interview sample compared to rates found in routine clinical screening (p values < .001).

CONCLUSIONS

Routine clinical screening may underestimate substance use among adolescents.

LC-HRMS-Database Screening Metrics for Rapid Prioritization of Samples to Accelerate the Discovery of Structurally New Natural Products

In order to accelerate the isolation and characterization of structurally new or novel secondary metabolites, it is crucial to develop efficient strategies that prioritize samples with greatest promise early in the workflow so that resources can be utilized in a more efficient and cost-effective manner. We have developed a metrics-based prioritization approach using exact LC-HRMS, which uses data for 24 618 marine natural products held in the PharmaSea database. Each sample was evaluated and allocated a metric score by a software algorithm based on the ratio of new masses over the total (sample novelty), ratio of known masses over the total (chemical novelty), number of peaks above a defined peak area threshold (sample complexity), and peak area (sample diversity). Samples were then ranked and prioritized based on these metric scores. To validate the approach, eight marine sponges and six tunicate samples collected from the Fiji Islands were analyzed, metric scores calculated, and samples targeted for isolation and characterization of new compounds. Structures of new compounds were elucidated by spectroscopic techniques, including 1D and 2D NMR, MS, and MS/MS. Structures were confirmed by computer-assisted structure elucidation methods (CASE) using the ACD/Structure Elucidator Suite.

Initiating methadone in jail and in the community: Patient differences and implications of methadone treatment for reducing arrests

The extent to which patient characteristics differ between individuals entering methadone treatment through community programs and jail-based programs is not known. Such differences could impact the likelihood of relapse and recidivism in these two populations and inform efforts at targeting interventions. We compared treatment-entry characteristics of participants enrolling in methadone treatment in two studies conducted in Baltimore, one conducted in community programs (N = 295) and the other in a jail-based program (N = 225). Controlling for age, race, and gender, individuals starting methadone treatment in jail compared to the community, had more severe drug use and criminal justice profiles. These different characteristics suggest that patients initiating methadone in a jail-based program could have greater likelihood of future arrest compared to patients entering community-based treatment. CLINICAL TRIALS REGISTRATION: Clinicaltrials.gov NCT 02334215 and NCT 01442493.

Pharmacotherapy for opioid addiction in community corrections

Pharmacotherapy for opioid addiction with methadone, buprenorphine, and naltrexone has proven efficacy in reducing illicit opioid use. These treatments are under-utilized among opioid-addicted individuals on parole, probation, or in drug courts. This paper examines the peer-reviewed literature on the effectiveness of pharmacotherapy for opioid addiction of adults under community-based criminal justice supervision in the US. Compared to general populations, there are relatively few papers addressing the separate impact of pharmacotherapy on individuals under community supervision. Tentative conclusions can be drawn from the extant literature. Reasonable evidence exists that illicit opioid use and self-reported criminal behaviour decline after treatment entry, and that these outcomes are as favourable among individuals under criminal justice supervision as the general treatment population. Surprisingly, there is no conclusive evidence regarding the extent to which pharmacotherapy impacts the likelihood of arrest and incarceration among individuals under supervision. However, given the proven efficacy of these three medications in reducing illicit opioid use and the evidence that, in the general population, methadone and buprenorphine treatment are associated with reduction in overdose mortality, the use of all three pharmacotherapies among patients under criminal justice supervision should be expanded while more data are collected on their impact on arrest and incarceration.

Re-engineering methadone-Cost-effectiveness analysis of a patient-centered approach to methadone treatment

Methadone maintenance treatment has proven effectiveness in the treatment of opioid use disorder, but significant barriers remain to treatment retention. In a randomized clinical trial, 300 newly-admitted methadone patients were randomly assigned to patient-centered methadone (PCM) v. treatment-as-usual (TAU). In PCM, participants were treated under revised program rules which permitted voluntary attendance at counseling and other changes focused on reducing involuntary discharge, and different staff roles which shifted disciplinary responsibility from the participant's counselor to the supervisor. The study found no significant differences in treatment retention, measures of opioid use, or other patient outcomes. This paper employs an activity-based costing approach to estimate the cost and cost-effectiveness of the two study conditions. We found that service use and costs were similar between PCM and TAU. Specifically, the average cost for PCM patients was $2396 compared to $2292 for standard methadone, while the average length of stay was 2 weeks longer for PCM patients. Incremental cost-effectiveness ratios (ICER) for self-reported heroin use, opioid positive urine screens, and meeting DSM-IV criteria for opioid dependence were mixed, with TAU achieving non-significantly better outcomes at lower treatment episode costs (i.e., economically dominating) for opioid positive urine screens. PCM patients reported slightly more days abstinent from heroin and fewer meet the opioid dependence criteria. While these differences are small and not statistically significant, we can still examine the cost-effectiveness implications. For days, abstinent from heroin, the ICER was $242 for one additional day of abstinence, however, there was notable uncertainty around this estimate. For opioid dependence criteria, the ICER was $1160 for a one-percentage point increase in the probability that a participant no longer met criteria for opioid dependence at follow-up. This economic study finds that patient choice concepts can be introduced into methadone treatment without significant impacts on costs or patient outcomes.

Characterisation of a pucBA deletion mutant from Rhodopseudomonas palustris lacking all but the pucBAd genes

Rhodopseudomonas palustris is a species of purple photosynthetic bacteria that has a multigene family of puc genes that encode the alpha and beta apoproteins, which form the LH2 complexes. A genetic dissection strategy has been adopted in order to try and understand which spectroscopic form of LH2 these different genes produce. This paper presents a characterisation of one of the deletion mutants generated in this program, the pucBAd only mutant. This mutant produces an unusual spectroscopic form of LH2 that only has a single large NIR absorption band at 800 nm. Spectroscopic and pigment analyses on this complex suggest that it has basically a similar overall structure as that of the wild-type HL LH2 complex. The mutant has the unique phenotype where the mutant LH2 complex is only produced when cells are grown at LL. At HL the mutant only produces the LH1-RC core complex.

Combining the platinum(ii) drug candidate kiteplatin with 1,10-phenanthroline analogues

Drug candidate kiteplatin has been combined with analogues of 1,10-phenanthroline, and the DNA affinity and cytotoxicity have been assessed.

When does methadone treatment reduce arrest and severity of arrest charges? An analysis of arrest records

This is an analysis of the odds of arrest, severity of charges, and factors predicting these outcomes in the year after methadone treatment entry using arrest records of patients (N=289) participating in two opioid treatment programs (OTPs) in Baltimore, MD as part of a previously-reported study. Baseline Addiction Severity Index data were examined along with publicly-available dates of arrest and arrest charges from the year before and after OTP entry. Severity of charges was rated independently by three researchers using a 1-7 point scale. Data were analyzed using Generalized Estimating Equations and Multiple Regression. The majority of the patients had no arrests over both time periods (61.6% and 65.7%, respectively). Of those arrested, the majority of the sample were charged with non-severe crimes in the year before and after OTP entry (82.9% and 73.7%, respectively). There were no significant differences in the odds of arrest or severity of charges in the year before versus the year after OTP admission (both ps>0.05). Predictors of arrest following admission included an arrest in the year prior to admission (p<0.001), younger age (p<0.001), and more lifetime months of incarceration (p=0.045). Predictors of the higher severity of charges included younger age (p<0.001), African-American race (p=0.032), and more lifetime months of incarceration (p=0.018). While in this population, the odds of arrest and severity of charges did not decrease significantly in the year following OTP entry, we discuss the need to avoid generalizing findings without considering those factors that may influence the likelihood of post-OTP entry arrest.

The concurrent validity of the Problem Oriented Screening Instrument for Teenagers (POSIT) substance use/abuse subscale in adolescent patients in an urban federally qualified health center

BACKGROUND

The Problem Oriented Screening Instrument for Teenagers (POSIT) substance use/abuse subscale has been validated with high school students, adolescents with criminal justice involvement, and adolescent substance use treatment samples using the Diagnostic and Statistical Manual of Mental Disorders (DSM)-III-R and DSM-IV. This study examines the concurrent validity of the POSIT's standard 17-item substance use/abuse subscale and a revised, shorter 11-item version using DSM-5 substance use disorder diagnoses.

METHODS

Adolescents (N = 525; 93% African American, 55% female) 12-17 years of age awaiting primary care appointments at a Federally Qualified Health Center in Baltimore, Maryland completed the 17-item POSIT substance use/abuse subscale and items from a modified World Mental Health Composite International Diagnostic Interview corresponding to DSM-5 alcohol use disorder (AUD) and cannabis use disorder (CUD). Receiver operating characteristic curves, sensitivities, and specificities were examined with DSM-5 AUD, CUD, and a diagnosis of either or both disorders for the standard and revised subscales using risk cutoffs of either 1 or 2 POSIT "yes" responses.

RESULTS

For the 17-item subscale, sensitivities were generally high using either cutoff (range: 0.79-1.00), although a cutoff of 1 was superior (sensitivities were 1.00 for AUD, CUD, and for either disorder). Specificities were also high using either cutoff (range: 0.81-0.95) but were higher using a cutoff of 2. For the 11-item subscale, a cutoff of 1 yielded higher sensitivities than a cutoff of 2 (ranges for 1 and 2: 0.96-1.00 and 0.79-0.86, respectively). Specificities for this subscale were higher using a cutoff of 2 (ranges for 1 and 2: 0.82-0.89 and 0.89-0.96, respectively).

CONCLUSIONS

Findings suggest that the POSIT's substance use/abuse subscale is a potentially useful tool for screening adolescents in primary care for AUD or CUD using a cutoff of 1 or 2. The briefer, revised subscale may be preferable to the standard subscale in busy pediatric practices.

Functional characterization of a constitutively active kinase variant of Arabidopsis phototropin 1

Phototropins (phots) are plasma membrane–associated serine/threonine kinases that coordinate a range of processes linked to optimizing photosynthetic efficiency in plants. These photoreceptors contain two light-, oxygen-, or voltage-sensing (LOV) domains within their N terminus, with each binding one molecule of flavin mononucleotide as a UV/blue light–absorbing chromophore. Although phots contain two LOV domains, light-induced activation of the C-terminal kinase domain and subsequent receptor autophosphorylation is controlled primarily by the A′α-LOV2-Jα photosensory module. Mutations that disrupt interactions between the LOV2 core and its flanking helical segments can uncouple this mode of light regulation. However, the impact of these mutations on phot function in Arabidopsis has not been explored. Here we report that histidine substitution of Arg-472 located within the A′α-helix of Arabidopsis phot1 constitutively activates phot1 kinase activity in vitro without affecting LOV2 photochemistry. Expression analysis of phot1 R472H in the phot-deficient mutant confirmed that it is autophosphorylated in darkness in vivo but unable to initiate phot1 signaling in the absence of light. Instead, we found that phot1 R472H is poorly functional under low-light conditions but can restore phototropism, chloroplast accumulation, stomatal opening, and leaf positioning and expansion at higher light intensities. Our findings suggest that Arabidopsis can adapt to the elevated phosphorylation status of the phot1 R472H mutant in part by reducing its stability, whereas the activity of the mutant under high-light conditions can be attributed to additional increases in LOV2-mediated photoreceptor autophosphorylation.

Update on Barriers to Pharmacotherapy for Opioid Use Disorders

PURPOSE OF REVIEW

The recent heroin and prescription opioid misuse epidemic has led to a sharp increase in the number of opioid overdose deaths in the USA. Notwithstanding the availability of three FDA-approved medications (methadone, buprenorphine, and naltrexone) to treat opioid use disorder, these medications are underutilized. This paper provides an update from the recent peer-reviewed literature on barriers to the use of these medications.

FINDINGS

These barriers are interrelated and can be categorized as financial, regulatory, geographic, attitudinal, and logistic. While financial barriers are common to all three medications, other barriers are medication-specific. The adverse impact of the current opioid epidemic on public health can be reduced by increasing access to effective pharmacotherapy for opioid use disorder.

Patient-centered methadone treatment: a randomized clinical trial

BACKGROUND AND AIMS

Methadone patients who discontinue treatment are at high risk of relapse, yet a substantial proportion discontinue treatment within the first year. We investigated whether a patient-centered approach to methadone treatment improved participant outcomes at 12 months following admission, compared with methadone treatment-as-usual.

DESIGN

Two-arm open-label randomized trial.

SETTING

Two methadone treatment programs (MTPs) in Baltimore, MD, USA.

PARTICIPANTS

Three hundred newly admitted MTP patients were enrolled between 13 September 2011 and 26 March 2014. Their mean age was 42.7 years [standard deviation (SD) = 10.1] and 59% were males.

INTERVENTION

Newly admitted MTP patients were assigned randomly to either patient-centered methadone treatment (PCM; n = 149), which modified the MTP's rules (e.g. counseling attendance was optional), and counselor roles (e.g. counselors were not responsible for enforcing clinic rules) or treatment-as-usual (TAU; n = 151).

MEASUREMENTS

The primary outcome was opioid-positive urine test at 12-month follow-up. Other 12-month outcomes included days of heroin and cocaine use, cocaine-positive urine tests, meeting DSM-IV opioid and cocaine dependence diagnostic criteria, HIV risk behavior and quality of life and retention in treatment.

FINDINGS

There was no significant difference between PCM and TAU conditions in opioid-positive urine screens at 12 months [adjusted odds ratio = 0.98; 95% confidence interval (CI) = 0.61, 1.56]. There were also no significant differences in any of the secondary outcome measures (all Ps > 0.05) except Quality of Life Global Score (P = 0.04; 95% CI = 0.01, 0.45). There were no significant differences between conditions in the number of individual or group counseling sessions attended. (Ps > 0.05).

CONCLUSIONS

Patient-centered methadone treatment (with optional counseling and the counselor not serving as the treatment program disciplinarian) does not appear to be more effective than methadone treatment-as-usual.

Spontaneous Assembly of an Organic-Inorganic Nucleic Acid Z-DNA Double-Helix Structure

Herein, we report a hybrid polyoxometalate organic-inorganic compound, Na₂ [(HGMP)₂ Mo₅ O₁₅ ]⋅7 H₂ O (1; where GMP=guanosine monophosphate), which spontaneously assembles into a structure with dimensions that are strikingly similar to those of the naturally occurring left-handed Z-form of DNA. The helical parameters in the crystal structure of the new compound, such as rise per turn and helical twist per dimer, are nearly identical to this DNA conformation, allowing a close comparison of the two structures. Solution circular dichroism studies show that compound 1 also forms extended secondary structures in solution. Gel electrophoresis studies demonstrate the formation of non-covalent adducts with natural plasmids. Thus we show a route by which simple hybrid inorganic-organic monomers, such as compound 1, can spontaneously assemble into a double helix without the need for a covalently connected linear sequence of nucleic acid base pairs.

Structure of the bacterial plant-ferredoxin receptor FusA

Iron is a limiting nutrient in bacterial infection putting it at the centre of an evolutionary arms race between host and pathogen. Gram-negative bacteria utilize TonB-dependent outer membrane receptors to obtain iron during infection. These receptors acquire iron either in concert with soluble iron-scavenging siderophores or through direct interaction and extraction from host proteins. Characterization of these receptors provides invaluable insight into pathogenesis. However, only a subset of virulence-related TonB-dependent receptors have been currently described. Here we report the discovery of FusA, a new class of TonB-dependent receptor, which is utilized by phytopathogenic Pectobacterium spp. to obtain iron from plant ferredoxin. Through the crystal structure of FusA we show that binding of ferredoxin occurs through specialized extracellular loops that form extensive interactions with ferredoxin. The function of FusA and the presence of homologues in clinically important pathogens suggests that small iron-containing proteins represent an iron source for bacterial pathogens.

Many bacteria use TonB-dependent outer membrane receptors to scavenge iron from their host during infection. Here, the authors report on the structure and function of FusA, which is a bacterial receptor that is used to obtain iron from plants.

An Ab Initio Description of the Excitonic Properties of LH2 and Their Temperature Dependence

The spectroscopic properties of light-harvesting (LH) antennae in photosyntehtic organisms represent a fingerprint that is unique for each specific pigment-protein complex. Because of that, spectroscopic observations are generally combined with structural data from X-ray crystallography to obtain an indirect representation of the excitonic properties of the system. Here, an alternative strategy is presented which goes beyond this empirical approach and introduces an ab initio computational description of both structural and electronic properties and their dependence on the temperature. The strategy is applied to the peripheral light-harvesting antenna complex (LH2) present in purple bacteria. By comparing this model with the one based on the crystal structure, a detailed, molecular level explanation of the absorption and circular dichroism (CD) spectra and their temperature dependence is achieved. The agreement obtained with the experiments at both low and room temperature lays the groundwork for an atomistic understanding of the excitation dynamics in the LH2 system.

Interim methadone and patient navigation in jail: Rationale and design of a randomized clinical trial

BACKGROUND

Methadone maintenance is an effective treatment for opioid dependence but is rarely initiated in US jails. Patient navigation is a promising approach to improve continuity of care but has not been tested in bridging the gap between jail- and community-based drug treatment programs.

METHODS

This is an open-label randomized clinical trial among 300 adult opioid dependent newly-arrested detainees that will compare three treatment conditions: methadone maintenance without routine counseling (termed Interim Methadone; IM) initiated in jail v. IM and patient navigation v. enhanced treatment-as-usual. The two primary outcomes will be: (1) the rate of entry into treatment for opioid use disorder within 30days from release and (2) frequency of opioid positive urine tests over the 12-month follow-up period. An economic analysis will examine the costs, cost-effectiveness, and cost-benefit ratio of the study interventions.

RESULTS

We describe the background and rationale for the study, its aims, hypotheses, and study design.

CONCLUSIONS

Given the large number of opioid dependent detainees in the US and elsewhere, initiating IM at the time of incarceration could be a significant public health and clinical approach to reducing relapse, recidivism, HIV-risk behavior, and criminal behavior. An economic analysis will be conducted to assist policy makers in determining the utility of adopting this approach. ClinicalTrials.gov: NCT02334215.

Observation of coherent delocalized phonon-like modes in DNA under physiological conditions

Underdamped terahertz-frequency delocalized phonon-like modes have long been suggested to play a role in the biological function of DNA. Such phonon modes involve the collective motion of many atoms and are prerequisite to understanding the molecular nature of macroscopic conformational changes and related biochemical phenomena. Initial predictions were based on simple theoretical models of DNA. However, such models do not take into account strong interactions with the surrounding water, which is likely to cause phonon modes to be heavily damped and localized. Here we apply state-of-the-art femtosecond optical Kerr effect spectroscopy, which is currently the only technique capable of taking low-frequency (GHz to THz) vibrational spectra in solution. We are able to demonstrate that phonon modes involving the hydrogen bond network between the strands exist in DNA at physiologically relevant conditions. In addition, the dynamics of the solvating water molecules is slowed down by about a factor of 20 compared with the bulk.

Pharmacotherapy for opioid dependence in jails and prisons: research review update and future directions

Purpose

The World Health Organization recommends the initiation of opioid agonists prior to release from incarceration to prevent relapse or overdose. Many countries in the world employ these strategies. This paper considers the evidence to support these recommendations and the factors that have slowed their adoption in the US.

Methods

We reviewed randomized controlled trials (RCTs) and longitudinal/observational studies that examine participant outcomes associated with the initiation or continuation of opioid agonists (methadone, buprenorphine) or antagonists (naltrexone) during incarceration. Papers were identified through a literature search of PubMed with an examination of their references and were included if they reported outcomes for methadone, buprenorphine, or naltrexone continued during incarceration or initiated prior to release in a correctional institution.

Results

Fourteen studies were identified, including eight RCTs and six observational studies. One RCT found that patients treated with methadone who were continued on versus tapered off methadone during brief incarceration were more likely to return to treatment upon release. A second RCT found that the group starting methadone treatment in prison versus a waiting list was less likely to report using heroin and sharing syringes during incarceration. A third RCT found no differences in postrelease heroin use or reincarceration between individuals initiating treatment with methadone versus those initiating treatment with buprenorphine during relatively brief incarcerations. Findings from four additional RCTs indicate that starting opioid agonist treatment during incarceration versus after release was associated with higher rates of entry into community treatment and reduced heroin use. Finally, one pilot RCT showed that providing extended-release naltrexone prior to discharge resulted in significantly lower rates of opioid relapse compared to no medication.

Conclusion

Reasons why uptake of these pharmacotherapies is limited in the US and relatively widespread in Europe are discussed. Recommendations for future research are outlined.

The CRAFFT cut-points and DSM-5 criteria for alcohol and other drugs: a reevaluation and reexamination

BACKGROUND

The CRAFFT, previously validated against DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) diagnostic criteria, is the most widely used screening instrument for alcohol and other substance misuse in adolescents. The present secondary analysis study sought to compare the CRAFFT with the new DSM-5 diagnostic criteria in order to assess the CRAFFT's psychometric properties and determine the optimal cut-point for identifying adolescents in need of further assessment.

METHODS

Participants were primary care patients aged 12-17 (N = 525) who were recruited while waiting for a medical appointment in an urban federally qualified health center in Baltimore, Maryland, USA. Participants were administered the CRAFFT and the Composite International Diagnostic Interview, second edition, modified to include the new DSM-5 craving item. The authors examined the performance of the CRAFFT in identifying any problem use (defined as 1 or more DSM-5 criteria) and any DSM-5 substance use disorder (2 or more DSM-5 criteria) for alcohol or drugs other than tobacco. The authors examined sensitivity, specificity, and receiver operating characteristic areas under the curve (AUC) to determine the optimal CRAFFT cut-point(s) for predicting any problem use and any DSM-5 substance use disorder (SUD).

RESULTS

Examining the CRAFFT as a continuous measure, AUC values were 0.93 for problem use or higher and 0.97 for DSM-5 SUD. Consistent with previously recommended cut-points for the CRAFFT, the cut-point of 2 performed optimally for identifying adolescents both exhibiting problem use of alcohol or drugs and meeting DSM-5 SUD criteria for alcohol or other drugs.

CONCLUSIONS

Despite changes in the DSM substance use diagnostic criteria, the CRAFFT continues to demonstrate excellent sensitivity and specificity at its established cut-point of 2. Additional studies examining the CRAFFT in light of the new DSM-5 diagnostic criteria with more diverse populations are warranted.

Discovery of a Single Monooxygenase that Catalyzes Carbamate Formation and Ring Contraction in the Biosynthesis of the Legonmycins

Pyrrolizidine alkaloids (PAs) are a group of natural products with important biological activities. The discovery and characterization of the multifunctional FAD-dependent enzyme LgnC is now described. The enzyme is shown to convert indolizidine intermediates into pyrrolizidines through an unusual ring expansion/contraction mechanism, and catalyze the biosynthesis of new bacterial PAs, the so-called legonmycins. By genome-driven analysis, heterologous expression, and gene inactivation, the legonmycins were also shown to originate from non-ribosomal peptide synthetases (NRPSs). The biosynthetic origin of bacterial PAs has thus been disclosed for the first time.

Manipulating adenovirus hexon hypervariable loops dictates immune neutralisation and coagulation factor X-dependent cell interaction in vitro and in vivo

Adenoviruses are common pathogens, mostly targeting ocular, gastrointestinal and respiratory cells, but in some cases infection disseminates, presenting in severe clinical outcomes. Upon dissemination and contact with blood, coagulation factor X (FX) interacts directly with the adenovirus type 5 (Ad5) hexon. FX can act as a bridge to bind heparan sulphate proteoglycans, leading to substantial Ad5 hepatocyte uptake. FX “coating” also protects the virus from host IgM and complement-mediated neutralisation. However, the contribution of FX in determining Ad liver transduction whilst simultaneously shielding the virus from immune attack remains unclear. In this study, we demonstrate that the FX protection mechanism is not conserved amongst Ad types, and identify the hexon hypervariable regions (HVR) of Ad5 as the capsid proteins targeted by this host defense pathway. Using genetic and pharmacological approaches, we manipulate Ad5 HVR interactions to interrogate the interplay between viral cell transduction and immune neutralisation. We show that FX and inhibitory serum components can co-compete and virus neutralisation is influenced by both the location and extent of modifications to the Ad5 HVRs. We engineered Ad5-derived HVRs into the rare, native non FX-binding Ad26 to create Ad26.HVR5C. This enabled the virus to interact with FX at high affinity, as quantified by surface plasmon resonance, FX-mediated cell binding and transduction assays. Concomitantly, Ad26.HVR5C was also sensitised to immune attack in the absence of FX, a direct consequence of the engineered HVRs from Ad5. In both immune competent and deficient animals, Ad26.HVR5C hepatic gene transfer was mediated by FX following intravenous delivery. This study gives mechanistic insight into the pivotal role of the Ad5 HVRs in conferring sensitivity to virus neutralisation by IgM and classical complement-mediated attack. Furthermore, through this gain-of-function approach we demonstrate the dual functionality of FX in protecting Ad26.HVR5C against innate immune factors whilst determining liver targeting.

Adenoviruses are mostly considered self-limiting pathogens associated with respiratory, gastrointestinal and ocular infections; however, in immunocompromised subjects disseminated Ad infection can occur with life-threatening consequences. Many human Ads are capable of binding to coagulation factor X (FX). Following intravenous administration in animal models, FX binds directly to the major Ad capsid protein, the hexon, which subsequently results in virus accumulation in the liver. FX coating Ad5 also acts to shield against immune neutralisation via natural IgM antibodies and the classical complement system. Here we show that FX protection is not a conserved mechanism amongst Ads and identify the Ad5 hexon hypervariable regions (HVR) as the capsid proteins targeted by this host defense pathway. Furthermore, we show that genetic inclusion of Ad5 HVRs onto a native non-FX binder Ad26 to be sufficient to confer sensitivity to immune attack in vitro and in vivo. Using intravenous administration, we determine the significance of FX binding to the Ad5-derived HVRs with respect to defending the virus from neutralisation whilst mediating virus tropism. Our study gives new insight into the role of the viral HVRs and of FX at the interface between virus and host defense mechanisms.

Validation and performance of the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) among adolescent primary care patients

BACKGROUND AND AIMS

The World Health Organization's Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) has strong support as a clinical screening tool and research instrument, but has only been validated with adults. This study evaluated the ASSIST and ASSIST-Lite in an adolescent population.

DESIGN

Internal consistency, concurrent validity, discriminant validity and diagnostic accuracy were examined for tobacco, alcohol and cannabis ASSIST scores. An abbreviated version (the ASSIST-Lite) was evaluated for cannabis.

SETTING

Three community health centers in Baltimore, MD, USA.

PARTICIPANTS

A total of 525 primary care patients, ages 12-17 years.

MEASUREMENTS

Measures included the ASSIST, the CRAFFT screening tool and items from the Composite International Diagnostic Interview (CIDI) corresponding to substance use disorder criteria in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition.

FINDINGS

The ASSIST had good internal consistency (α = 0.68-0.88), good concurrent validity with the CRAFFT (r = 0.41-0.76; P < 0.001), and was able to discriminate between gradations of cannabis problem severity. In receiver operating characteristics analysis of optimal clinical cut-points, the ASSIST accurately identified tobacco, alcohol and cannabis use disorders (sensitivities = 95-100%; specificities = 79-93%; area under the curve [AUC] = 0.90-0.94), but did so at minimally low cut-points (indicative of any use in the past 3 months). The ASSIST-Lite performed similarly to the ASSIST in identifying cannabis use disorders (sensitivity = 96%; specificity = 88%; AUC = 0.92), also at a minimally low cut-point. However, confirmatory factor analysis of the ASSIST indicated poor model fit.

CONCLUSIONS

The Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) is promising as a research and screening/brief assessment tool with adolescents, but revisions to clinical risk thresholds are warranted. The ASSIST-Lite is sufficiently informative for rapid clinical screening of adolescents for cannabis use disorders.

Heroin Use, HIV-Risk, and Criminal Behavior in Baltimore: Findings from Clinical Research

This article reviews research conducted in Baltimore over the past 15 years, examining the following: (1) What factors differentiate heroin-addicted individuals who enter methadone treatment from those who do not? (2) How difficult is gaining access to methadone treatment? (3) What are effective ways to overcome barriers to treatment entry? (4) Why do so many methadone patients drop out of treatment prematurely? (5) What are the added benefits of counseling when coupled with methadone or buprenorphine treatment? (6) Does increasing access to treatment have an impact on overdose deaths? Specific recommendations are made for policymakers concerned with addressing heroin addiction.

Alignment of nanostructured tripeptide gels by directional ultrasonication

We demonstrate an in situ ultrasonic approach to generate anisotropic organo- and hydrogels consisting of oriented tripeptides self-assembled structures.

Recombinant expression, purification, crystallization and preliminary X-ray diffraction analysis of the C-terminal DUF490(963-1138) domain of TamB from Escherichia coli

TamB is a recently described inner membrane protein that, together with its partner protein TamA, is required for the efficient secretion of a subset of autotransporter proteins in Gram-negative bacteria. In this study, the C-terminal DUF490963-1138 domain of TamB was overexpressed in Escherichia coli K-12, purified and crystallized using the sitting-drop vapour-diffusion method. The crystals belonged to the primitive trigonal space group P3121, with unit-cell parameters a = b = 57.34, c = 220.74 Å, and diffracted to 2.1 Å resolution. Preliminary secondary-structure and X-ray diffraction analyses are reported. Two molecules are predicted to be present in the asymmetric unit. Experimental phasing using selenomethionine-labelled protein will be undertaken in the future.

Screening of DUB activity and specificity by MALDI-TOF mass spectrometry

Deubiquitylases (DUBs) are key regulators of the ubiquitin system which cleave ubiquitin moieties from proteins and polyubiquitin chains. Several DUBs have been implicated in various diseases and are attractive drug targets. We have developed a sensitive and fast assay to quantify in vitro DUB enzyme activity using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Unlike other current assays, this method uses unmodified substrates, such as diubiquitin topoisomers. By analysing 42 human DUBs against all diubiquitin topoisomers we provide an extensive characterization of DUB activity and specificity. Our results confirm the high specificity of many members of the OTU and JAB/MPN/Mov34 metalloenzyme DUB families and highlight that all USPs tested display low linkage selectivity. We also demonstrate that this assay can be deployed to assess the potency and specificity of DUB inhibitors by profiling 11 compounds against a panel of 32 DUBs.

Deubiquitylases (DUBs) remove ubiquitin chains from proteins. Here the authors develop a mass spectrometry-based DUB activity screen using unmodified diubiquitin isomers to characterize substrate specificity for 42 human DUBs, and assess the potency and selectivity of 11 DUB inhibitors.

Concordance between DSM-5 and DSM-IV nicotine, alcohol, and cannabis use disorder diagnoses among pediatric patients

BACKGROUND

The recently published Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) includes several major revisions to substance use diagnoses. Studies have evaluated the impact of these changes among adult samples but research with adolescent samples is lacking.

METHODS

525 adolescents (93% African American) awaiting primary care appointments in Baltimore, Maryland were recruited for a study evaluating a substance use screening instrument. Participants were assessed for DSM-5 nicotine, alcohol, and cannabis use disorder, DSM-IV alcohol and cannabis abuse, and DSM-IV dependence for all three substances during the past year using the modified Composite International Diagnostic Interview-2, Substance Abuse Module. Contingency tables examining DSM-5 vs. DSM-IV joint frequency distributions were examined for each substance.

RESULTS

Diagnoses were more prevalent using DSM-5 criteria compared with DSM-IV for nicotine (4.0% vs. 2.7%), alcohol (4.6% vs. 3.8%), and cannabis (10.7% vs. 8.2%). Cohen's κ, Somers' d, and Cramer's V ranged from 0.70 to 0.99 for all three substances. Of the adolescents categorized as "diagnostic orphans" under DSM-IV, 7/16 (43.8%), 9/29 (31.0%), and 13/36 (36.1%) met criteria for DSM-5 disorder for nicotine, alcohol, and cannabis, respectively. Additionally, 5/17 (29.4%) and 1/21 (4.8%) adolescents who met criteria for DSM-IV abuse did not meet criteria for a DSM-5 diagnosis for alcohol and cannabis, respectively.

CONCLUSIONS

Categorizing adolescents using DSM-5 criteria may result in diagnostic net widening-particularly for cannabis use disorders-by capturing adolescents who were considered diagnostic orphans using DSM-IV criteria. Future research examining the validity of DSM-5 substance use disorders with larger and more diverse adolescent samples is needed.

Structure of the atypical bacteriocin pectocin M2 implies a novel mechanism of protein uptake

The colicin-like bacteriocins are potent protein antibiotics that have evolved to efficiently cross the outer membrane of Gram-negative bacteria by parasitizing nutrient uptake systems. We have structurally characterized the colicin M-like bacteriocin, pectocin M2, which is active against strains of Pectobacterium spp. This unusual bacteriocin lacks the intrinsically unstructured translocation domain that usually mediates translocation of these bacteriocins across the outer membrane, containing only a single globular ferredoxin domain connected to its cytotoxic domain by a flexible α-helix, which allows it to adopt two distinct conformations in solution. The ferredoxin domain of pectocin M2 is homologous to plant ferredoxins and allows pectocin M2 to parasitize a system utilized by Pectobacterium to obtain iron during infection of plants. Furthermore, we identify a novel ferredoxin-containing bacteriocin pectocin P, which possesses a cytotoxic domain homologous to lysozyme, illustrating that the ferredoxin domain acts as a generic delivery module for cytotoxic domains in Pectobacterium.

Validity of brief screening instrument for adolescent tobacco, alcohol, and drug use

BACKGROUND AND OBJECTIVE

The National Institute on Alcohol Abuse and Alcoholism developed an alcohol screening instrument for youth based on epidemiologic data. This study examines the concurrent validity of this instrument, expanded to include tobacco and drugs, among pediatric patients, as well as the acceptability of its self-administration on an iPad.

METHODS

Five hundred and twenty-five patients (54.5% female; 92.8% African American) aged 12 to 17 completed the Brief Screener for Tobacco, Alcohol, and other Drugs (BSTAD) via interviewer-administration or self-administration using an iPad. Diagnostic and Statistical Manual, Fifth Edition substance use disorders (SUDs) were identified using a modified Composite International Diagnostic Interview-2 Substance Abuse Module. Receiver operating characteristic curves, sensitivities, and specificities were obtained to determine optimal cut points on the BSTAD in relation to SUDs.

RESULTS

One hundred fifty-nine (30.3%) adolescents reported past-year use of ≥1 substances on the BSTAD: 113 (21.5%) used alcohol, 84 (16.0%) used marijuana, and 50 (9.5%) used tobacco. Optimal cut points for past-year frequency of use items on the BSTAD to identify SUDs were ≥6 days of tobacco use (sensitivity = 0.95; specificity = 0.97); ≥2 days of alcohol use (sensitivity = 0.96; specificity = 0.85); and ≥2 days of marijuana use (sensitivity = 0.80; specificity = 0.93). iPad self-administration was preferred over interviewer administration (z = 5.8; P < .001).

CONCLUSIONS

The BSTAD is a promising screening tool for identifying problematic tobacco, alcohol, and marijuana use in pediatric settings. Even low frequency of substance use among adolescents may indicate need for intervention.