An Exploratory Study on Determinants of Regular Group Indoor Cycling Participation in Black and White Adults

This study investigated factors influencing regular group indoor cycling (GIC) participation in a sample of Black (71%) and White (29%) adults. Seventeen regular GIC participants (≥1 day/week for ≥3 consecutive months) completed surveys that examined motivations for GIC participation. Treatment Self-Regulation Questionnaire (TSRQ), Preference for and Tolerance of Intensity of Exercise Questionnaire (PRETIE-Q), and open-ended survey questions were used. TSRQ showed autonomous motivation was significantly higher than controlled (p \u3c.001) and amotivation (p \u3c .001), with no significant difference between controlled and amotivation (p = .08). There was no significant interaction between motivation and race. There were no significant differences between race groups for PRETIE-Q. Five themes emerged as reasons for GIC participation: music, physical health, social support, studio atmosphere, and enjoyment/fun. Racial differences surfaced in the themes. More research is needed to understand the role of cultural relevance as it relates to exercise motivation and regular exercise participation. This could inform strategies for promoting regular exercise in various populations

Cannabigerolic acid, a major biosynthetic precursor molecule in cannabis, exhibits divergent effects on seizures in mouse models of epilepsy

Background and Purpose: Cannabis has been used to treat epilepsy for millennia, with such use validated by regulatory approval of cannabidiol (CBD) for Dravet syndrome. Unregulated artisanal cannabis-based products used to treat children with intractable epilepsies often contain relatively low doses of CBD but are enriched in other phytocannabinoids. This raises the possibility that other cannabis constituents might have anticonvulsant properties. Experimental Approach: We used the Scn1a+/− mouse model of Dravet syndrome to investigate the cannabis plant for phytocannabinoids with anticonvulsant effects against hyperthermia-induced seizures. The most promising, cannabigerolic acid (CBGA), was further examined against spontaneous seizures and survival in Scn1a+/− mice and in electroshock seizure models. Pharmacological effects of CBGA were surveyed across multiple drug targets. Key Results: The initial screen identified three phytocannabinoids with novel anticonvulsant properties: CBGA, cannabidivarinic acid (CBDVA) and cannabigerovarinic acid (CBGVA). CBGA was most potent and potentiated the anticonvulsant effects of clobazam against hyperthermia-induced and spontaneous seizures, and was anticonvulsant in the MES threshold test. However, CBGA was proconvulsant in the 6-Hz threshold test and a high dose increased spontaneous seizure frequency in Scn1a+/− mice. CBGA was found to interact with numerous epilepsy-relevant targets including GPR55, TRPV1 channels and GABAA receptors. Conclusion and Implications: These results suggest that CBGA, CBDVA and CBGVA may contribute to the effects of cannabis-based products in childhood epilepsy. Although these phytocannabinoids have anticonvulsant potential and could be lead compounds for drug development programmes, several liabilities would need to be overcome before CBD is superseded by another in this class

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Cannabis constituents interact at the drug efflux pump BCRP to markedly increase plasma cannabidiolic acid concentrations.

Cannabis is a complex mixture of hundreds of bioactive molecules. This provides the potential for pharmacological interactions between cannabis constituents, a phenomenon referred to as "the entourage effect" by the medicinal cannabis community. We hypothesize that pharmacokinetic interactions between cannabis constituents could substantially alter systemic cannabinoid concentrations. To address this hypothesis we compared pharmacokinetic parameters of cannabinoids administered orally in a cannabis extract to those administered as individual cannabinoids at equivalent doses in mice. Astonishingly, plasma cannabidiolic acid (CBDA) concentrations were 14-times higher following administration in the cannabis extract than when administered as a single molecule. In vitro transwell assays identified CBDA as a substrate of the drug efflux transporter breast cancer resistance protein (BCRP), and that cannabigerol and Δ9-tetrahydrocannabinol inhibited the BCRP-mediated transport of CBDA. Such a cannabinoid-cannabinoid interaction at BCRP transporters located in the intestine would inhibit efflux of CBDA, thus resulting in increased plasma concentrations. Our results suggest that cannabis extracts provide a natural vehicle to substantially enhance plasma CBDA concentrations. Moreover, CBDA might have a more significant contribution to the pharmacological effects of orally administered cannabis extracts than previously thought

Coadministered cannabidiol and clobazam : preclinical evidence for both pharmacodynamic and pharmacokinetic interactions

Objective: Cannabidiol (CBD) has been approved by the US Food and Drug Administration (FDA) to treat intractable childhood epilepsies, such as Dravet syn-drome and Lennox‐Gastaut syndrome. However, the intrinsic anticonvulsant activity of CBD has been questioned due to a pharmacokinetic interaction between CBD and a first‐line medication, clobazam. This recognized interaction has led to speculation that the anticonvulsant efficacy of CBD may simply reflect CBD augmenting clobazam exposure. The present study aimed to address the nature of the interaction between CBD and clobazam. Methods: We examined whether CBD inhibits human CYP3A4 and CYP2C19 mediated metabolism of clobazam and N‐desmethylclobazam (N‐CLB), respectively, and performed studies assessing the effects of CBD on brain and plasma pharma-cokinetics of clobazam in mice. We then used the Scn1a+/− mouse model of Dravet syndrome to examine how CBD and clobazam interact. We compared anticonvulsant effects of CBD‐clobazam combination therapy to monotherapy against thermally‐in-duced seizures, spontaneous seizures and mortality in Scn1a+/− mice. In addition, we used Xenopus oocytes expressing γ‐aminobutyric acid (GABA)A receptors to investigate the activity of GABAA receptors when treated with CBD and clobazam together. Results: CBD potently inhibited CYP3A4 mediated metabolism of clobazam and CYP2C19 mediated metabolism of N‐CLB. Combination CBD‐clobazam treatment resulted in greater anticonvulsant efficacy in Scn1a+/− mice, but only when an anticonvulsant dose of CBD was used. It is important to note that a sub‐anticonvulsant dose of CBD did not promote greater anticonvulsant effects despite increasing plasma clobazam concentrations. In addition, we delineated a novel pharmacodynamic mechanism where CBD and clobazam together enhanced inhibitory GABAA receptor activation

Measuring Drug Metabolism Kinetics and Drug–Drug Interactions Using Self-Assembled Monolayers for Matrix-Assisted Laser Desorption-Ionization Mass Spectrometry

The competition of two drugs for the same metabolizing enzyme is a common mechanism for drug–drug interactions that can lead to altered kinetics in drug metabolism and altered elimination rates <i>in vivo</i>. With the prevalence of multidrug therapy, there is great potential for serious drug–drug interactions and adverse drug reactions. In an effort to prevent adverse drug reactions, the FDA mandates the evaluation of the potential for metabolic inhibition by every new chemical entity. Conventional methods for assaying drug metabolism (e.g., those based on HPLC) have been established for measuring drug–drug interactions; however, they are low-throughput. Here we describe an approach to measure the catalytic activity of CYP2C9 using the high-throughput technique self-assembled monolayers for matrix-assisted laser desorption-ionization (SAMDI) mass spectrometry. We measured the kinetics of CYP450 metabolism of the substrate, screened a set of drugs for inhibition of CYP2C9 and determined the <i>K</i>_i values for inhibitors. The throughput of this platform may enable drug metabolism and drug–drug interactions to be interrogated at a scale that cannot be achieved with current methods

An Examination of the Anti-Cancer Properties of Plant Cannabinoids in Preclinical Models of Mesothelioma

Mesothelioma is an aggressive cancer with limited treatment options and a poor prognosis. Phytocannabinoids possess anti-tumour and palliative properties in multiple cancers, however their effects in mesothelioma are unknown. We investigated the anti-cancer effects and potential mechanisms of action for several phytocannabinoids in mesothelioma cell lines. A panel of 13 phytocannabinoids inhibited growth of human (MSTO and H2452) and rat (II-45) mesothelioma cells in vitro, and cannabidiol (CBD) and cannabigerol (CBG) were the most potent compounds. Treatment with CBD or CBG resulted in G0/G1 arrest, delayed entry into S phase and induced apoptosis. CBD and CBG also significantly reduced mesothelioma cell migration and invasion. These effects were supported by changes in the expression of genes associated with the cell cycle, proliferation, and cell movement following CBD or CBG treatment. Gene expression levels of CNR1, GPR55, and 5HT1A also increased with CBD or CBG treatment. However, treatment with CBD or CBG in a syngeneic orthotopic rat mesothelioma model was unable to increase survival. Our data show that cannabinoids have anti-cancer effects on mesothelioma cells in vitro and alternatives of drug delivery may be needed to enhance their effects in vivo

Fine Mapping of a Dravet Syndrome Modifier Locus on Mouse Chromosome 5 and Candidate Gene Analysis by RNA-Seq

<div><p>A substantial number of mutations have been identified in voltage-gated sodium channel genes that result in various forms of human epilepsy. <i>SCN1A</i> mutations result in a spectrum of severity ranging from mild febrile seizures to Dravet syndrome, an infant-onset epileptic encephalopathy. Dravet syndrome patients experience multiple seizures types that are often refractory to treatment, developmental delays, and elevated risk for SUDEP. The same sodium channel mutation can produce epilepsy phenotypes of varying clinical severity. This suggests that other factors, including genetic, modify the primary mutation and change disease severity. Mouse models provide a useful tool in studying the genetic basis of epilepsy. The mouse strain background can alter phenotype severity, supporting a contribution of genetic modifiers in epilepsy. The <i>Scn1a</i>^<i>+/-</i> mouse model has a strain-dependent epilepsy phenotype. <i>Scn1a</i>^<i>+/-</i> mice on the 129S6/SvEvTac (129) strain have a normal phenotype and lifespan, while [129xC57BL/6J]F1-<i>Scn1a</i>^<i>+/-</i> mice experience spontaneous seizures, hyperthermia-induced seizures and high rates of premature death. We hypothesize the phenotypic differences are due to strain-specific genetic modifiers that influence expressivity of the <i>Scn1a</i>^<i>+/-</i> phenotype. Low resolution mapping of <i>Scn1a</i>^<i>+/-</i> identified several Dravet syndrome modifier (<i>Dsm</i>) loci responsible for the strain-dependent difference in survival. One locus of interest, <i>Dsm1</i> located on chromosome 5, was fine mapped to a 9 Mb region using interval specific congenics. RNA-Seq was then utilized to identify candidate modifier genes within this narrowed region. Three genes with significant total gene expression differences between 129S6/SvEvTac and [129xC57BL/6J]F1 were identified, including the GABA_A receptor subunit, <i>Gabra2</i>. Further analysis of <i>Gabra2</i> demonstrated allele-specific expression. Pharmological manipulation by clobazam, a common anticonvulsant with preferential affinity for the GABRA2 receptor, revealed dose-dependent protection against hyperthermia-induced seizures in <i>Scn1a</i>^<i>+/-</i> mice. These findings support <i>Gabra2</i> as a genetic modifier of the <i>Scn1a</i>^<i>+/-</i> mouse model of Dravet syndrome.</p></div