Thought of the Day
April 3, 2016
It’s not ideal for your summary statement to show up whilst at a meeting attended by many of the people on the review panel.
BSD moves to emulate
April 3, 2016
Bryan Roth, of Salvanorin A and DREADD fame, was honored by ASPET with the Goodman and Gilman award at EB. In his award lecture he gave a great summary of his work to date, which is all very cool.
But one thing he did was to emphasize how a master’s degreed tech in his lab made one of the major discoveries, that she refused to take first author and that is the only reason she wasn’t listed first.
That is the kind of thing people who are in the Coalition of the Decent do.
Good to find scientific hero types remembering to credit where due.
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Other Reading: You are not “just” a tech
Co-first and CV from R Schekman
April 3, 2016
Experimental Biology 2016
April 3, 2016
Today was a looooong travel day for YHN but I’m finally in San Diego and ready for an excellent time at Experimental Biology. Hoping to catch up at least briefly with a number of y’all blog Readers and the SciTweeple.
As always, if you would like to mention your presentation details in the comments or via the blog email, feel free. (I might even see a Twitter DM or two if you choose to go that route. ) I try to swing by when I can and some of the commentariat might like to see your stuff as well.
This is an overview of a presentation in Symposium 491. Scientists versus Street Chemists: The Toxicity of Designer Marijuana presented Wed, Apr 30, 9:30 AM – 12:00 PM at the 2014 Experimental Biology meeting.
Jeffrey Moran (PubMed) of the Arkansas Department of Public Health opened with an overview of synthetic cannabinoid products being sold and consumed by individuals seeking a marijuana-like high. The state of Arkansas has established a response to the emergence of synthetic cannabimimetic and stimulant drugs which includes government, academic, clinical and private resources. It is currently called the Center for Drug Detection and Response. He specifically mentioned his own analytic laboratory in the Department of Public Health, academic scientists at the University of Arkansas for Medical Sciences and Cayman Chemicals. The latter company has been essential in preparing analytical standards for their assessment of parent drugs and, in particular, the metabolites that might be found in human samples.An analytical chemist’s approach to public health problems by J. H. Moran
Dr. Moran briefly overviewed the history of the appearance of 3 gram packets of dried plant material selling for $20-$50 each. Rather than boutique potporri, such packets are laced with synthetic cannabinoid drugs. They started appearing in the US around 2008 or 2009 and Arkansas identified their first item in 2010.
From 2010 until the present (2014), Moran’s laboratory in the Department of Health has assessed over 4,300 synthetic drug items and 1,823 human samples. From this they have identified 47 different synthetic cannabinoids, 17 designer stimulants and 9 designer hallucinogens. From this diversity, how to triage? How to decide what to focus on? Well, Dr. Moran said that a half dozen cannabinoid compounds (of the 47) amounted to about 80-90% of the samples they’ve analyzed to date. If I had it right, his summary slide of top suspects included JWH-018, AM2201, UR-144, XLR-11, AB-PINACA, AB-FUBINACA and PB-22. (I may have missed a couple). Interestingly, although Dr. Moran mentioned some compounds dropping off the radar following specific DEA Scheduling actions, and new entities arising to replace them, JWH-018 has been making a comeback. This points, in my view, to an important reminder. Despite the fact that the diversity in designer cannabinoids and cathinones appears to be driven by legal status, it is good to remember there are plenty of highly popular recreational drugs which are clearly illegal and have been so for many decades. I would predict a winnowing process whereby a few highly attractive exemplars of the cannabinoid and cathinone classes of drugs remain with us, even when they have been placed under control by the DEA (or act of Congress).
Dr. Moran when on to mention that the preparations available on the street are not exclusively predictive when it comes to appearances. That is, you might suspect that anything made of dried plant matter might contain cannabinoids where as tablets, capsules and loose powder or crystalline substances might be the cathinones. Although generally true, a few herbal material samples contained synthetic cathinones and a few “pills and powders” were found to contain synthetic cannabinoids.
Dr. Moran also described his role as a public health official by depicting statewide tracking data. The different streams of information can be synthesized and direct him / his office to the right population. If he sees a lot of activity through poison control lines with no corresponding alerts from the law enforcement, then maybe he needs to reach out to local police jurisdictions. Likewise, a flurry of law enforcement without any activity from Emergency Departments may indicate a need to educate health care professionals on what to look for in that community.
One cannot help but walk away from this presentation with an appreciation for two things. One, we are fortunate that the Arkansas folks have taken a lead in generating a wealth of information on the use of cannabimimetic drugs. Second, it is always a pleasure to learn more about how someone with a job mandate that isn’t strictly academic responds to an emerging recreational drug situation like we have been experiencing of late.
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Dr. Moran disclosed his participation in Pin Point Testing, LLC.
This is an overview of a presentation in Symposium 491. Scientists versus Street Chemists: The Toxicity of Designer Marijuana Wed, Apr 30, 9:30 AM – 12:00 PM at Experimental Biology 2014.
Wed, Apr 30, 10:45 – 11:10 AM Clinical and unexplained idiosyncratic toxicity of K2 exposure by G. Buser of the Oregon Health Authority.
One potential health consequence of the use of synthetic cannabinoids is acute kidney injury (AKI) or nephrotoxicity. There have been Case Reports published and there are more cases described in the MMWR report of the US CDC.
Buser indicated that in Oregon the index case for her agency’s attention was a 17 yo male who reported to the emergency department where he was found to have abnormal kidney function. He had been smoking a synthetic cannabis product. With such a finding, there are a number of questions: Is it a contaminant? Possibly a toxic solvent used to prepare the product? Toxic constituents of the plant material used for a given product? A hot spot in the product that resulted in an unusually high dose?
This thinking triggered an investigation around the state of OR, in which medical facilities, officers and other public health authorities were queried for cases of unexplained nephrotoxicity in young adults. Buser identified several additional cases in which it appeared from case histories that the smoking of synthetic cannabis products were involved. The author then attempted to secure the clinical course, case histories and any clinical samples collected.
She ended up with 9 cases collected between May-Oct 2012, all male with a median age of 18. Due to the variability in the cases, the onset from last smoking to symptoms was 2 weeks to 30 minutes although Buser cautioned that the case histories derived from friend or the user might not be that reliable.
Affected individuals (also see the above links) tend to suffer from nausea, vomiting and abdominal/flank/back pain. Buser said that in the OR cases, the individuals tended to wait anywhere from 12 hrs to a day after the start of their symptoms, thinking that it would resolve by itself.
The cases typically featured abnormal clinical chemistry (BUN, serum creatinine), proteinuria and kidney biopsies were found to confirm both acute tubular nephritis and interstitial nephritis.
The study interviewed 6 of 9 cases, all were habitual marijuana smokers, had obtained their synthetic cannabis over the counter from convenience stores or head shops and they reported 5 different product brand names. The team was able to secure 2 of the products for testing.
One of the more frustrating issues for a study like this is that the patients reported to Emergency services of some sort a long time after last exposure to synthetic cannabis. So there is a good deal of uncertainty about being able to detect any of the known agents. Nevertheless, one invidual was positive for (1-(5-fluoropentyl)-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl) methanone (XLR-11). No other known cannabimimetics were found. This individual happened to be one (of the two) for whom they were able to secure and analyze a sample of the product he had used. It was also positive for XLR-11.
XLR-11 was found in four of the five product samples and four of six patient’s specimens in the WY report as well.
It appears to be the case that no other cannabimimetic compounds have been reported in association with acute kidney injury. Obviously, the data are thin and in many cases of AKI, there are no analyses of the product and timing may be such that clinical sample would be negative anyway.
Still, there is enough of a smoking gun here to recommend some preclinical studies on the nephrotoxic effects of XLR-11, as mentioned by Buser.
Buser ended up by observing that in three of the cases there were other people smoking the same product with the affected individual. It was speculated that perhaps there was a hot spot, perhaps those individuals smoked more or perhaps they had an individul liability. With respect to the latter, she noted that two brother pairs were represented in the affected sample. This might point to shared genetic liability for these adverse effects of XLR-11 consumption.
One major takeaway from the presentation is that a specific synthetic cannabinoid might have specific risks for kidney injury. A second major takeaway is that we know far too little about this phenomenon, both from a mechanistic perspective and an epidemiological one. Efforts from public health officials such as Buser can enhance awareness and therefore detection of human cases.
This is a summary of a presentation in Symposium 222. Molecular Basis of Addiction: Neurocognitive Deficits and Memory Mon, Apr 28, 9:55 AM – 12:10 PM at the 2014 Experimental Biology meeting.
Mon, Apr 28, 10:25 – 10:40 AM Amphetamine exposure during development causes epigenetic trans-generational changes in drug sensitivity in Caenorhabditis elegant. Authors: Talus McCowan, Bryan Safratowich, Joyce Ohm, Lucia Carvelli
McCowen* presented a study which showed transgenerational effects of amphetamine in a C. elegans model.
Caenorhabditis elegans is a nematode about 1 mm long which has the dubious virtue of having 302 neurons of which a mere 8 are dopaminergic. This makes for a tractable model, particularly when you think you might want to model the entire nervous system.
The model involved Swimming Induced Paralysis (SWIP) which can be induced in a liquid medium by treating the worm with amphetamine. This is a time and dose dependent phenomenon which has been shown to depend on the dopamine transporter and D2/3-like dopamine receptors. Classic targets of the amphetamines.
The study exposed eggs to 500 uM amphetamine or control media for 15 hours. After maturation of the worms, they were subjected to the SWIP test in which it was found that the egg-exposed animals had an enhanced freezing response. In this case it was an increased percentage of the worms freezing in the context of a moderate dose, selected to give parametric range on either side. The authors then examined the F1 generation of worms, which had received no drug treatment up until the SWIP challenge. here it was found that the F1 offspring of the F0 worms exposed to amphetamine during development also had an enhanced response to amphetamine.
The lab is interested in methylation of histones as an epigenetic mechanism that might possibly convey this effect. They found decreases of histone H3 Lys4 trimethylation (H3K4me3) in the F1 offspring of amphetamine incubated worms compared with the offspring of control worms. This was selective as there was no difference in H3K27me3 expression.
Obviously this is just a start, one would think that the advantage of the worm is that you could go out for generations quite readily, in comparison with rodents (see below). So presumably this story will advance by the time we see it in publication. Nevertheless, this joins a growing appreciation of the transgenerational effects of drug. While there are many caveats in translating this to humans, it certainly puts a bright spotlight on familial abuse patterns and our potential targets for explaining them.
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Related: Heritability of Substance Abuse Meets Epigenetics?
*The speaker identified himself as a first year graduate student. I think he did a bang up job of the presentation and of handling the questions.
Experimental Biology 2014: Non-alcoholic fatty liver disease
April 29, 2014
I learned something at poster session 1116. Alcoholic and Nonalcoholic Fatty Liver Disease
Tue, Apr 29, 7:30 AM – 4:00 PM.
Tue, Apr 29, 12:45 – 3:00 PM 1116.11/A601 – Low copper and dietary sucrose drive fibrosis pathways in a rat model of non-alcoholic fatty-liver disease
Tallino and Burkhead presented a poster studying non-alcoholic fatty liver disease in a rodent model. I’m most used to considering similar damage in the context of alcohol exposure, given that abused drugs are my focus. So it was interesting to learn that some 20-25% of those on a Western diet may exhibit some signs of fatty liver disease that has nothing to do with alcohol.
The study Tallino and Burkhead conducted was based on evidence that steatosis may be related to copper (Cu) deficiency and that this may interact with sucrose in the diet.
The study consisted of four groups of Wistar rats, exposed to different dietary conditions for 12 weeks. The factors were a diet either sufficient or deficient in Cu and a 10% or 30% sucrose addition.
The authors show that low Cu diet works, serum Cu was significantly lowered in these groups. Interestingly there was an interaction whereby the group with low Cu and 30% sucrose diet was further depleted in serum Cu. As expected, serum glucose was elevated with 30% sucrose but this was only out of the normal range with the low Cu / 30% sucrose group.
Interestingly, these dietary conditions resulted in no change in free fatty acids and no change in body weight. Remember that now.
The low Cu diet increased liver steatosis significantly with an interaction with the sucrose treatment to increase this sign of non-alcoholic fatty-liver disease. So Cu deficiency can combine with high sucrose in the diet to produce liver damage in the absence of other indications of a fatty diet (weight gain, high circulating triglycerides).
The study then went on to find that the high sucrose, low Cu diet was associated with alterations in gene transcripts related to fibrosis progression, hepatic stellate cell activation and a few other things related to the hypothesized model of damage.
Will a dual sigma receptor antagonist / dopamine transporter inhibitor treat stimulant abuse?
April 28, 2014
This post covers a platform presentation in symposium 222. Molecular Basis of Addiction: Neurocognitive Deficits and Memory (Mon, Apr 28, 9:55 AM – 12:10 PM) at the 2014 Experimental Biology meeting.
803.3/D382 – Preclinical efficacy of the dual sigma receptor antagonist dopamine uptake inhibitor, CM699, as a medication for stimulant abuse
Johnathan Katz of the NIDA Intramural Research program presented an overview of the data and findings that led up to the creation of a new molecule (CM699) that functions a both a dopamine transporter (DAT) inhibitor and a sigma receptor antagonist. As a bit of background, NIDA has spent a tremendous amount of effort trying to use dopamine transporter inhibitors as agonist therapy for stimulant abuse. The theory of agonist therapy is familiar from the nicotine patch and methadone. The outline is that if you have a drug which mimics the abused drug in effect but has different time-course of effect, you may be able to blunt the acute high of the preferred drug and/or method of use. The nicotine patch supplies the identical drug but in a more sustained, slower and less-peaky manner. Methadone is relatively long acting at endogenous opioid receptors, apparently providing relief without the acute euphoric high. A similar strategy has governed attempts to identify compounds which would confer protection against stimulant abuse.
Since the acute reinforcing effect of stimulants such as cocaine and methamphetamine is mediated through the DAT, this was the target of considerable NIDA effort over decades. It has not been a successful effort.
First off, Katz pointed out that calling sigma a “receptor” is bit of a misnomer as it functions as an intracelluar chaperone protein. This molecule hangs out in association with the endoplasmic reticulum but under ligand activation can migrate to modulate the function of membrane bound proteins. One of those is apparently the dopamine transporter.
Another background consideration for the presentation is that cocaine, as Katz noted, blocks the DAT but also has some sigma affinity. The significance of this agonist activity was not made entirely clear in the talk and we should keep in mind that any antagonism of the sigma receptor will also likely remove the sigma-mediated effects of cocaine. This part was not well explicated in the talk.
At any rate, sigma antagonist compounds block the effects of cocaine. Katz described data indicating that the acute locomotor stimulant effect of cocaine can be prevented and that sigma antagonists can attenuate lethality from an otherwise toxic dose of cocaine.
An initial study from Remi Martin-Fardon, however, found that one sigma antagonist (BD1047) did not reduce cocaine self-administration. Katz then tested several additional sigma antagonists to rigorously determine that no, sigma antagonist compounds by themselves did not reduce cocaine self-administration, even cross a wide range of cocaine doses.
Katz next presented data to remind us that the DAT inhibitor methylphenidate (aka Ritalin) not only fails to reduce cocaine self-administration but that it can increase the self-administration of lower per-infusion doses of cocaine.
However, the combination of methylphenidate with any of several sigma antagonists produced an “insurmountable antagonism” of cocaine self-administration. Meaning that across a wide range of per-infusion doses of cocaine, the rats now failed to self-administer. Importantly, these combinations had no effect on food maintained operant responding, no effect on self administration of opioids or direct dopamine D1 or D2 like receptor agonists but did work to suppress methamphetamine self-administration. This indicates the effect is specific to DAT mediated reinforcing effects.
This all led up to the creation of a compound (CM699) that had the ability to both antagonize sigma receptors and to inhibit the DAT. It was found to blunt the dopamine response to acute cocaine, as measured with intracerebral microdialysis. Furthermore, this single compound produced the “insurmountable antagonism” of cocaine self-administration that had been found for the two-drug combinations.
The talk ended with a proposal that the mechanism of action is that sigma antagonism depletes cholesterol from the membrane which promotes an inward-facing conformation of the DAT.
Obviously, Katz is optimistic that this combined-action CM699 compound proves the concept for a stimulant abuse treatment medication. The half-life of this particular compound was only about 4 and a half hours, thus their immediate goal is to get a longer acting compound which both antagonizes sigma and blocks the dopamine transporter. Nevertheless, the chance that it can completely remove the rewarding properties of cocaine supports the idea that combined activity at DAT and sigma is the route to effective agonist therapy for stimulant abuse.
Will You Be Attending Experimental Biology 2014?
April 17, 2014
The good folks at the American Society for Pharmacology and Experimental Therapeutics have seen fit to invite me to serve as an official blogger for the Experimental Biology 2014 meeting to be held in San Diego, CA, April 26-30. I will be joined in this effort by @katiesci who blogs at http://sicknessisfascinating.blogspot.com.
I would like to invite you, Dear Readers, to send me your presentation details, should you be attending this year. You can drop a note in the comments to this thread or send me an email (drugmnky at the google mail). I will try to stop by if it fits in my schedule and maybe blog it if I can understand what you do.
There may also be a meet up or two which revolves around either this community at the blog or my Twitter Tweeps. So stay in touch about that. If you are interested in such a thing and leave a comment, this may help to stimulate someone (say, me) to get off their behind and organize something.
Looking forward to seeing some of your science and to meeting some of you.
Are you attending Experimental Biology 2012?
April 12, 2012
I decided to go to EB12 so I’ll extend my offer/request from the usual SFN routine.
No promises, but if you drop me a line (drugmnky at the googles) or post your presentation details in the comments, I’ll try to stop by. Might even blog your work!
Also, there may be coffee klatch…interested?
DrugMonkey 