Aerobic exercise training reduces cannabis craving and use in non-treatment seeking cannabis-dependent adults

Background

Cannabis dependence is a significant public health problem. Because there are no approved medications for this condition, treatment must rely on behavioral approaches empirically complemented by such lifestyle change as exercise.

Aims

To examine the effects of moderate aerobic exercise on cannabis craving and use in cannabis dependent adults under normal living conditions.

Design

Participants attended 10 supervised 30-min treadmill exercise sessions standardized using heart rate (HR) monitoring (60–70% HR reserve) over 2 weeks. Exercise sessions were conducted by exercise physiologists under medical oversight.

Participants

Sedentary or minimally active non-treatment seeking cannabis-dependent adults (n = 12, age 25±3 years, 8 females) met criteria for primary cannabis dependence using the Substance Abuse module of the Structured Clinical Interview for DSM-IV (SCID).

Measurements

Self-reported drug use was assessed for 1-week before, during, and 2-weeks after the study. Participants viewed visual cannabis cues before and after exercise in conjunction with assessment of subjective cannabis craving using the Marijuana Craving Questionnaire (MCQ-SF).

Findings

Daily cannabis use within the run-in period was 5.9 joints per day (SD = 3.1, range 1.8–10.9). Average cannabis use levels within the exercise (2.8 joints, SD = 1.6, range 0.9–5.4) and follow-up (4.1 joints, SD = 2.5, range 1.1–9.5) periods were lower than during the run-in period (both P<.005). Average MCQ factor scores for the pre- and post-exercise craving assessments were reduced for compulsivity (P  = .006), emotionality (P  = .002), expectancy (P  = .002), and purposefulness (P  = .002).

Conclusions

The findings of this pilot study warrant larger, adequately powered controlled trials to test the efficacy of prescribed moderate aerobic exercise as a component of cannabis dependence treatment. The neurobiological mechanisms that account for these beneficial effects on cannabis use may lead to understanding of the physical and emotional underpinnings of cannabis dependence and recovery from this disorder.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00838448","term_id":"NCT00838448"}}NCT00838448]     

Characterizing hospital workers' willingness to respond to a radiological event

Introduction

Terrorist use of a radiological dispersal device (RDD, or “dirty bomb”), which combines a conventional explosive device with radiological materials, is among the National Planning Scenarios of the United States government. Understanding employee willingness to respond is critical for planning experts. Previous research has demonstrated that perception of threat and efficacy is key in the assessing willingness to respond to a RDD event.

Methods

An anonymous online survey was used to evaluate the willingness of hospital employees to respond to a RDD event. Agreement with a series of belief statements was assessed, following a methodology validated in previous work. The survey was available online to all 18,612 employees of the Johns Hopkins Hospital from January to March 2009.

Results

Surveys were completed by 3426 employees (18.4%), whose demographic distribution was similar to overall hospital staff. 39% of hospital workers were not willing to respond to a RDD scenario if asked but not required to do so. Only 11% more were willing if required. Workers who were hesitant to agree to work additional hours when required were 20 times less likely to report during a RDD emergency. Respondents who perceived their peers as likely to report to work in a RDD emergency were 17 times more likely to respond during a RDD event if asked. Only 27.9% of the hospital employees with a perception of low efficacy declared willingness to respond to a severe RDD event. Perception of threat had little impact on willingness to respond among hospital workers.

Conclusions

Radiological scenarios such as RDDs are among the most dreaded emergency events yet studied. Several attitudinal indicators can help to identify hospital employees unlikely to respond. These risk-perception modifiers must then be addressed through training to enable effective hospital response to a RDD event.     

High genetic diversity despite the potential for stepping-stone colonizations in an invasive species of gecko on Moorea, French Polynesia

Invasive species often have reduced genetic diversity, but the opposite can be true if there have been multiple introductions and genetic admixture. Reduced diversity is most likely soon after establishment, in remote locations, when there is lower propagule pressure and with stepping-stone colonizations. The common house gecko (Hemidactylus frenatus) was introduced to Moorea, French Polynesia in the remote eastern Pacific within the last two decades and accordingly is expected to exhibit low diversity. In contrast, we show that H. frenatus on Moorea has exceptionally high genetic diversity, similar to that near the native range in Asia and much higher than reported for other Pacific island reptiles. The high diversity in this recently founded population likely reflects extensive genetic admixture in source population(s) and a life history that promotes retention of diversity. These observations point to the importance of understanding range-wide dynamics of genetic admixture in highly invasive species.     

Going coastal: shared evolutionary history between coastal British Columbia and Southeast Alaska wolves (Canis lupus)

Background

Many coastal species occupying the temperate rainforests of the Pacific Northwest in North America comprise endemic populations genetically and ecologically distinct from interior continental conspecifics. Morphological variation previously identified among wolf populations resulted in recognition of multiple subspecies of wolves in the Pacific Northwest. Recently, separate genetic studies have identified diverged populations of wolves in coastal British Columbia and coastal Southeast Alaska, providing support for hypotheses of distinct coastal subspecies. These two regions are geographically and ecologically contiguous, however, there is no comprehensive analysis across all wolf populations in this coastal rainforest.

Methodology/Principal Findings

By combining mitochondrial DNA datasets from throughout the Pacific Northwest, we examined the genetic relationship between coastal British Columbia and Southeast Alaska wolf populations and compared them with adjacent continental populations. Phylogenetic analysis indicates complete overlap in the genetic diversity of coastal British Columbia and Southeast Alaska wolves, but these populations are distinct from interior continental wolves. Analyses of molecular variation support the separation of all coastal wolves in a group divergent from continental populations, as predicted based on hypothesized subspecies designations. Two novel haplotypes also were uncovered in a newly assayed continental population of interior Alaska wolves.

Conclusions/Significance

We found evidence that coastal wolves endemic to these temperate rainforests are diverged from neighbouring, interior continental wolves; a finding that necessitates new international strategies associated with the management of this species.     

Enhanced collateral growth by double transplantation of gene-nucleofected fibroblasts in ischemic hindlimb of rats

Background

Induction of neovascularization by releasing therapeutic growth factors is a promising application of cell-based gene therapy to treat ischemia-related problems. In the present study, we have developed a new strategy based on nucleofection with alternative solution and cuvette to promote collateral growth and re-establishment of circulation in ischemic limbs using double transplantation of gene nucleofected primary cultures of fibroblasts, which were isolated from rat receiving such therapy.

Methods and Results

Rat dermal fibroblasts were nucleofected ex vivo to release bFGF or VEGF165 in a hindlimb ischemia model in vivo. After femoral artery ligation, gene-modified cells were injected intramuscularly. One week post injection, local confined plasmid expression and transient distributions of the plasmids in other organs were detected by quantitative PCR. Quantitative micro-CT analyses showed improvements of vascularization in the ischemic zone (No. of collateral vessels via micro CT: 6.8±2.3 vs. 10.1±2.6; p<0.05). Moreover, improved collateral proliferation (BrdU incorporation: 0.48±0.05 vs. 0.57±0.05; p<0.05) and increase in blood perfusion (microspheres ratio: gastrocnemius: 0.41±0.10 vs. 0.50±0.11; p<0.05; soleus ratio: soleus: 0.42±0.08 vs. 0.60±0.08; p<0.01) in the lower hindlimb were also observed.

Conclusions

These results demonstrate the feasibility and effectiveness of double transplantation of gene nucleofected primary fibroblasts in producing growth factors and promoting the formation of collateral circulation in ischemic hindlimb, suggesting that isolation and preparation of gene nucleofected cells from individual accepting gene therapy may be an alternative strategy for treating limb ischemia related diseases.     

Über das Invertierungsvermögen der Speicheldrüsen und des Mitteldarmes von Bienen verschiedenen Alters

Zusammenfassung Die gewonnenen Ergebnisse zeigen mit völliger Klarheit, daß die Schlunddrüse ein stark ausgesprochenes Invertierungsvermögen besitzt, das sich jedoch in hohem Grade, je nach dem Alter der Bienen ändert. Im Gegensatz zum Mitteldarm, der Invertase auszuscheiden beginnt von dem Augenblicke des Ausschlüpfens der jungen Biene, bedarf die Schlunddrüse eines gewissen Zeitraumes zu ihrer Entwicklung. Die von uns angestellten Versuche können indessen die Frage noch nicht endgültig entscheiden, in welchem Moment die Schlunddrüse zu funktionieren beginnt. Wir haben die Sekretionstätigkeit der Drüse an verhältnismäßig alten Bienen — von 10 Tagen an — beobachtet und die maximalen Ziffern der Zuckerinversion bei 30tägigen Bienen ermittelt. Hieraus lassen sich noch keine verallgemeinernden Schlüsse ziehen. Unsere Versuche begannen im August und dauerten bis Mitte September, fanden also am Ende der Saison statt. Das Versuchsvolk war schwach und die Zahl der jungen Bienen und der Brut gering (auf einem Rahmen). Als Beleg dazu genügt der Hinweis, daß die Bienen ihre Orientierungsausflüge im Alter von 18 Tagen unternahmen. Alle diese Faktoren könnten zweifellos das Tempo der Entwicklung des Organismus der Biene — und der Sehlunddrüse im besonderen — beeinflussen. Es ist sehr wahrscheinlich, daß eine Untersuchung über die Veränderung des Invertierungsvermögens der Schiunddrüsen von Bienen, die zu verschiedenen Zeiten der Frühlings- und Sommersaison ausgeschlüpft waren, auch eine verschiedene Schnelligkeit der Entwicklung der Drüse ergeben würde.Was die Brustdrüse anbetrifft, so geben unsere Versuche kein genügendes Material zur Beurteilung, welche Rolle sie im Kohlehydratstoffwechsel der Biene spielt. Nur eines steht fest, daß sie an der Invertierung des Zuckers in keinem Falle beteiligt ist.Der Mitteldarm scheint auch mit dem Alter der Biene sein Invertierungsvermögen zu steigern, wenn auch nicht in solchem Umfange als die Schlunddrüse.Die von uns gewonnenen Resultate erlauben, einige Schlüsse über mehrere Fragen der Bienenbiologie zu ziehen, wie z. B. die Frage über den Anteil der Schlunddrüse an der Futtersaftbereitung usw. Doch müssen solche spezielle Fragen an einer anderen Stelle ausführlich besprochen werden.Zum Schlusse sprechen wir Dr. Resnitschenko sowie Dr. Alpatov für die freundliche Hilfe bei der Ausführung der Arbeit unseren Dank aus.