Dr. Springer[/caption]
Matthew L. Springer, Ph.D.
Associate Professor of Medicine
Division of Cardiology
Cardiovascular Research Institute
Broad Center of Regeneration Medicine and Stem Cell Research
Center for Tobacco Control Research & Education
Helen Diller Family Comprehensive Cancer Center
University of California, San Francisco
Medical Research: What is the background for this study? What are the main findings?
Dr. Springer: The general public is aware that cigarette secondhand smoke is harmful. However, many people who actively avoid tobacco secondhand smoke don't feel the need to avoid marijuana secondhand smoke; they don't consider it harmful because there's no nicotine and because we who tell them to avoid tobacco smoke don't tell them to avoid marijuana smoke. However, secondhand smoke from tobacco and marijuana is very similar in chemical composition (4000-7000 chemicals depending on whom you ask), aside from the nicotine and the THC (the psychoactive drug in marijuana).
We and others have shown that brief exposure to tobacco secondhand smoke, such as 30 minutes, at real-world levels impairs vascular function in humans. We developed a way to study vascular function (measured as arterial flow-mediated dilation; FMD) in living rats, and recently published that even one minute of sidestream smoke from the burning tips of tobacco cigarettes, a well-accepted model for secondhand smoke, is enough to start detecting impairment of FMD. The main findings of the current study are that in laboratory rats, FMD was substantially impaired by a 30 minute exposure to marijuana secondhand smoke, when measured 10 minutes after the end of exposure. Impairment was comparable to that resulting from exposure to tobacco sidestream smoke, although whereas impairment from tobacco smoke was temporary and had normalized by 40 minutes later, FMD was still impaired 40 minutes after the end of exposure to marijuana smoke. Smoke from marijuana lacking THC still impaired FMD, showing that
MedicalResearch.com Interview with:
David Plurad, MD
Los Angeles Biomedical Research Institute.
Medical Research: What are the main findings of the study?
Based on a survey of patients with traumatic brain injuries, a group of Los
Angeles Biomedical Research Institute researchers found those who tested
positive for tetrahydrocannabinol (THC), the active ingredient in marijuana, were more likely to survive than those who tested negative for the illicit substance.
We surveyed 446 patients who were admitted to a major urban hospital with
traumatic brain injuries between Jan. 1, 2010, and Dec. 31, 2012, who were
also tested for the presence of THC in their urine. We found 82 of the
patients had THC in their system. Of those, 2.4% died. Of the remaining
patients who didn't have THC in their system, 11.5% died.
While most - but not all - the deaths in the study can be attributed to the
traumatic brain injury itself, it appears that both groups were similarly
injured. The similarities in the injuries between the two groups led to the
conclusion that testing positive for THC in the system is associated with a
decreased mortality in adult patients who have sustained traumatic brain
injuries.
MedicalResearch.com Interview with:
Anna-Karin Danielsson, PhD
Project Coordinator
Karolinska Institutet
Department of Public Health Sciences (PHS)
Widerströmska huset| Stockholm, Sweden
Medical Research: What are the main findings of the study?
Dr. Danielsson: Smoking cannabis in adolescence increases the risk of adverse social consequences later on in life.
MedicalResearch.com Interview with:
Chuanhai Cao Ph.D.
Neuroscientist at the Byrd Alzheimer's Institute
and the USF College of Pharmacy.
Medical Research: What are the main findings of the study?
Dr. Cao: The major goal of this study was to investigate the effect of Ä9-tetrahydrocannabinol (THC), a major component of marijuana, on Alzheimer’s disease (AD) pathology. THC has long been known to have anti-inflammatory effects, but we were looking to determine whether THC directly affected amyloid beta (Aâ). Aâ aggregation is considered one of the key pathological hallmarks of Alzheimer’s disease. Our study showed that extremely low doses of THC were able to decrease Aâ production, inhibit Aâ aggregation, and enhance mitochondrial function in a cellular model of AD. Decreased levels of amyloid beta, coupled with THC’s inhibitory effect on aggregation may protect against the progression of Alzheimer’s disease.
MedicalResearch.com Interview with:
Meesha Ahuja, MD
Department of Psychiatry and Human Behavior of the
Warren Alpert Medical School of Brown University
Young Adult Behavioral Health Program at Rhode Island Hospital
Mentors: Laura Whiteley, MD and Larry Brown, MD
MedicalResearch: Why did you decided to study this topic?
Dr. Ahuja: Severe mental illness is more common among college students than it was a decade ago, and the number of college students presenting for psychiatric care both on and off campus has dramatically increased. The rates of cannabis use have also been increasing among college students in the United States since the mid-1990s. The concomitant use of cannabis and other substances among general samples in psychiatric treatment has been linked to poorer clinical outcomes including increased hospitalizations, increased symptomatology, poorer treatment adherence, higher treatment resistance. However, before doing this study, there was no research that examined the effect of cannabis and other substance use disorders on the scholastic and general functioning of college students in psychiatric care.
MedicalResearch.com Interview with:
Emilie Jouanjus, PharmD, PhD
Risques, maladies chroniques et handicaps
Facult_e de M_edecine,
Guesde, Toulouse 31073, France.
MedicalResearch.com: What are the main findings of the study?
Dr. Jouanjus: Our study emphasizes that cardiovascular complications make up 1.8 percent of cannabis-related health complications reported in France. These were cases of peripheral arteriopathies, and cardiac and cerebrovascular disorders, some of which resulted in the death. These findings conducted us to conclude that marijuana is a possible risk factor for cardiovascular disease in young adults.
MedicalResearch.com Interview with:
Mary-Ann Fitzcharles, MB, ChB, MRCP(UK), FRCP(C)
McGill University Health Centre
Division of Rheumatology and Alan Edwards Pain Management Unit
MedicalResearch.com: What are the highlights of your review?
Dr. Fitzcharles: Thank you for your interest in the review article which will shortly be published in Arthritis Care & Research. This was not a research study but rather a review focused towards the use of herbal cannabis for patients with rheumatic diseases.
The essence of our message after a thorough review of the literature is that there is not a single study published regarding efficacy or side effects of herbal cannabis in the rheumatic diseases. It is notable that almost 2 thirds of persons using herbal cannabis for therapeutic reasons report use for musculoskeletal complaints. In the 21st century, we cannot rely upon heresay or anecdote to justify use of a treatment intervention. It is unacceptable to recommend use of a substance without knowledge of concentration of molecules in the product, any knowledge of blood concentrations that might have a positive or negative effect, and formal study in defined patient populations with acceptable endpoint criteria and evidence for short and long term risks.
MedicalResearch.com Interview with:
Joanne E. Brady SM
Senior Staff Associate
Department of Anesthesiology
Doctoral Candidate in Epidemiology
Columbia University Medical Center
New York, NY 10032
Department of Epidemiology,
Columbia’s Mailman School of Public Health
MedicalResearch.com: What are the main findings of the study?
Answer: The prevalence of non-alcohol drugs detected in fatally injured drivers in the U.S. increased from 17% in 1999 to 28% in 2010. The increases are largely driven by the tripling in the prevalence of cannabis.
MedicalResearch.com Interview with:
David J. Allsop, PhD
National Cannabis Prevention and Information Centre, National Drug and Alcohol Research Centre, Faculty of Medicine
Now with the School of Psychology, University of Sydney, Sydney, Australia
MedicalResearch.com: What are the main findings of the study?
Dr. Allsop: We found that administering a botanical preparation of the cannabinoids Tetrahydrocannabidiol (THC - the main psychoactive ingredient in cannabis) and Cannabidiol (a lesser known component of the cannabis plant that
counteracts the psychotogenic effects of THC with anxiolytic properties) to
dependent cannabis smokers during initial abstinence from cannabis
substantially dampened their withdrawal experience. In essence this is akin
to Nicotine Replacement Therapy (NRT) but for cannabis users. It might seem
obvious - sure you give cannabis users a cannabis preparation and they find
it easier to quit - but this is important because it has never been done
before - and we currently have no consensus evidence based medicines to
offer cannabis users who ask for help.
MedicalResearch.com Interview with:
W. Scott Burgin, MD
Professor and Chief, Cerebrovascular Division
Director, Comprehensive Stroke Center
Department of Neurology
USF College of Medicine
Tampa General Hospital Stroke Center.
MedicalResearch.com What are the main findings of the study?
Dr. Burgin: Two cases of stroke, of embolic appearance, shortly after smoking synthetic marijuana.
MedicalResearch.com Interview with:
Professor John Zajicek
Professor of Clinical Neuroscience, Centre for Clinical Trials & Health Research - Translational & Stratified Medicine (Peninsula Schools of Medicine and Dentistry)
MedicalResearch.com: What are the main findings of the study?
Prof. Zajicek: Our study investigated whether dronabinol (one of the major active ingredients of cannabis) may slow the progression of multiple sclerosis. We currently have no treatments that are effective in modifying the disease course in people with either primary or secondary MS. We did a clinical trial across the UK involving nearly 500 patients, who were randomly allocated to dronabinol or placebo, and followed them up for three years to look at progression on rates. Overall we failed to find an effect of dronabinol on disease progression, either clinically (using a variety of clinical measures) or using magnetic resonance imaging (MRI). There was a suggestion of an effect in people with the least disability (who didn't need a stick to help them walk), and there were no major problems with serious side effects. However, over all the population that took part in the study also progressed less than we expected, which reduced our chances of finding an effect of treatment. The study was not designed to investigate an effect on MS-related symptoms (such as pain and muscle stiffness), which have been investigated before.