by Nestor Lopez-Duran PhD in Child-Psych
Today the American Psychiatric Association released a draft of the major changes that are expected in the new version of the Diagnostic and Statistical Manual of Mental Disorder – 5th Edition (DSM-V). While most people in the field will be underwhelmed by the relatively minor changes, there are a few areas where the DSM-V will [...]... Read more »
Brotman MA, Schmajuk M, Rich BA, Dickstein DP, Guyer AE, Costello EJ, Egger HL, Angold A, Pine DS, & Leibenluft E. (2006) Prevalence, clinical correlates, and longitudinal course of severe mood dysregulation in children. Biological psychiatry, 60(9), 991-7. PMID: 17056393
Every so often this cocaine vaccine issue rears its head again. I saw it again just the other day. The problem is, of course, the tendency of the media (ain't it always the media) to say something like "OMG THIS IS TEH CURE FOR EVERYTHING!" in response to one small study. And who knows, the cocaine vaccine may indeed be the cure for everything, but Sci needs to see some big trials before she gets her hopes up. As it is, the studies I have seen provide some interesting clues, but also provide some important warnings.
So, first question first: how the heck do you make a cocaine vaccine?
Haney et al. "Cocaine-specific antibodies blunt the subjective effects of smoked cocaine in humans" Biological Psychiatry, 2009. Read the rest of this post... | Read the comments on this post...... Read more »
Haney, M., Gunderson, E., Jiang, H., Collins, E., & Foltin, R. (2010) Cocaine-Specific Antibodies Blunt the Subjective Effects of Smoked Cocaine in Humans. Biological Psychiatry, 67(1), 59-65. DOI: 10.1016/j.biopsych.2009.08.031
A recent study in the American Academy of Neurology found that people with Alzheimer’s disease have a significantly reduced risk of being hospitalized for cancer.... Read more »
Roe CM, Fitzpatrick AL, Xiong C, Sieh W, Kuller L, Miller JP, Williams MM, Kopan R, Behrens MI, & Morris JC. (2010) Cancer linked to Alzheimer disease but not vascular dementia. Neurology, 74(2), 106-12. PMID: 20032288
There are two main kinds of Complementary and Alternative Medicine (CAM) - the ones that involve actually doing stuff, and the ones that don't.Things like herbal medicine, chiropractic, and acupuncture could plausibly make someone better, as more than just a placebo, given what we know about physics and chemistry, because they involve physically acting on the body. I don't claim to know whether they do in fact work, but in theory, they could.Other CAM techniques, however, are just magic. Homeopathy is the best example of this: it cannot work, except as a placebo, unless our understanding of nature is fundamentally wrong. The "active ingredient" in a homeopathic remedy is diluted in water to the point where not a single molecule of it remains (and then diluted more, for good measure). If some mystical "essence" or "energy" can somehow survive in water despite dilution then, logically, all water must contain the essence of pretty much everything. It literally involves nothing beyond sugar pills and waterBut there's one useful thing about homeopathy: it shines a light on the rest of modern medical science, or rather, it holds up a mirror to it. Unfortunately, the reflection is not as pretty as you'd hope.These two graphs come from a paper by Shang et al, Are the clinical effects of homoeopathy placebo effects?, which was a major meta-analysis of 110 randomized, placebo-controlled trials (RCTs) of homeopathy. It was published in The Lancet in 2005.Shang et al 2005 was bad news for homeopathy, because it concluded that "[the meta-analysis] is compatible with the notion that the clinical effects of homoeopathy are placebo effects." - i.e., homeopathy doesn't work. Since its publication the paper has been hotly criticized by homeopaths, and defended by skeptics, with the skeptics generally being right. But it was bad news for conventional medicine too.These two graphs are funnel plots. Each dot represents a published RCT. Dots to the left of the vertical line are trials where the 'active treatment' did better than the placebo control; the further left, the better. The higher up the dot is, the more "precise" the results of the trial, i.e. the less variability there was in the results. They may not look like much, but they're terrifying.The top funnel plot shows the 110 published RCTs of homeopathy for various illnesses. The bottom one shows 110 RCTs of "proper" medical treatments, for the same diseases, that Shang et al picked out as comparisons. You'll notice that the two plots look rather similar - there's a lot of spread, but most of the dots are to the left of the vertical line, meaning that the treatments were better than the placebos. Quite a lot are very far to the left, meaning the treatment worked really well. Very few are on the right.But homeopathic treatments, by definition, are placebos - they're literally sugar pills. So any trial of homeopathy should have an equal chance of finding it to be better than placebo, or worse. Placebos are placebos. It should be a coin toss, 50/50. In fact, Shang et al found only about 20 trials showing homeopathic placebos to be worse than placebo placebos, and 90 finding they were better.How can this be? Either homeopathy works, in which case we need to rewrite physics and chemistry, or there is something very wrong with the published literature. I find it easier to believe the latter. But then how could the published literature be so wrong?Almost certainly the answer is publication bias, broadly speaking. If people do a trial and don't get the result they want, they generally either don't write it up for publication; or if they try to, it doesn't get published. Related to this is selective outcome bias: they pick out and write up only those results that do match what they wanted; or they pick out statistical techniques to get the result they wanted, etc.The plot for homeopathy RCTs is what you get when people study a treatment that doesn't work, but that they believe does work, and publish their findings in a biased way. But the plot for "real" medicines looks disturbingly like that.In other words, the whole clinical trial literature - all of those RCTs and meta-analyses, published in respectable journals, the ones we rely on to determine what treatment decisions doctors make - could be produced even if all of our treatments were no better than placebos. Like I said, terrifying.I should stress that this doesn't mean that real medicines are no better than placebos. Shang et al's results are also what you'd see if there's no publication bias in conventional medicine, and the treatments work really well. (The evidence for positive effects in the "real medicine" trials was also somewhat stronger than in the homeopathy trials - the dots were further left - which is reassuring, but the difference was pretty small.) The problem though is that we can't tell - at least not on the basis of the clinical trial literature.Luckily, there's an answer - mandatory registration of clinical trials. Medical journals or, ideally, governments, can require researchers to publicly announce the details of each trial, and how they plan to analyze the results, before the trial takes place, and require that the final results are made public. The USA has had such a system in place, backed by law, since 2007, and most major medical journals now demand registration.Sadly, biases still seem to be happening in registered trials. But this doesn't mean the system doesn't work, it just means it should be more strictly enforced, and extended to other countries and, I'd argue, beyond just clinical trials. Either that, or we might as well take up homeopathy.... Read more »
Shang, A., Huwiler-Müntener, K., Nartey, L., Jüni, P., Dörig, S., Sterne, J., Pewsner, D., & Egger, M. (2005) Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy. The Lancet, 366(9487), 726-732. DOI: 10.1016/S0140-6736(05)67177-2
How many of you have headed off to ‘Therapy Worksheets’ blog? Yes, that’s the one I’ve linked to in my roundup of the best CBT resources on the internet. Will Baum, the editor of that blog is also the author of where the client is, a blog about professional private practice in mental health care. [...]... Read more »
YUNUS, M. (2007) Fibromyalgia and Overlapping Disorders: The Unifying Concept of Central Sensitivity Syndromes. Seminars in Arthritis and Rheumatism, 36(6), 339-356. DOI: 10.1016/j.semarthrit.2006.12.009
This video is about mirror neurons. These mirror neurons are the key to many aspects of social interaction. It allows us to understand the actions, feelings of others. In a way to “read their minds”. Possibly mirror neurons play an important role in empathy , an important asset for physicians.
But were do they come from [...]
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An important Canadian study has shown that the use of paroxetine (Paxil) in breast cancer patients taking tamoxifen is associated with an increased risk of death from breast cancer. These findings, which were published this week in the British Medical Journal, add to a growing body of evidence that certain (but not all) SSRI antidepressants neutralize tamoxifen's beneficial effects in treating breast cancer by interfering with it's metabolism.First, a few things about the study -The study was done using a combination of pharmacy records, cancer registry records, hospital databases and death certificates in seniors, the age group for whom this data were readily available. The study included women taking both tamoxifen and an SSRI between 1993 and 2005. The median age was 74 years old (range 70-79 years) We know nothing about the stage of breast cancer in these patientsBy the end of the 2.8 year follow up, 44% of the participants had died from any cause (not surprising given the age of the study cohort), including 15% in whom breast cancer was listed as one of the causes of death. No comparisons were done among women taking tamoxifen only. The researchers compared women taking different SSRI's to one another, and within each SSRI group, compared different duration of uses as a way to measure the effect of the potential interaction. What the researchers foundUse of Paxil was associated with an increase in deaths from both breast cancer and other causes during the follow-up period. (See PowerPoint graph ). The increase in risk was higher with longer overlapping use of Paxil with tamoxifen, and ranged from 25% to 91% increase as time on the two drugs together increased, meaning that the risk was almost double with longest use in the study. All of these results were statistically significant. (For those who know statistics, that's a relative risk of 1.24 to 1.91 and the 95% confidence intervals did not include 1).In more meaningful layman's terms, there will be 1 additional breast cancer death for every 20 women taking Paxil and Tamoxifen together 41% of the time (the average in the study). If Paxil is taken the entire time tamoxifen is used, there will be 1 additional death for every 7 women treated with both drugs.What is additionally interesting about these numbers, according to the study's researcher Dr. David Juurlink (who graciously agreed to speak to me today), is that 7 is the number of women need to treat with Tamoxifen to prevent one breast cancer death. So, Paxil essentially is neutralizing the tamoxifen effect.The Results are Biologically PlausibleIn order to be effective, tamoxifen must be converted in the body to its active metabolites, the most potent of which is 4-hydroxy-N-desmethyltamoxifen or endoxifen. The conversion of tamoxifen to endoxifen is catalyzed by an enzyme called CYP2D6. SSRI antidepressants interfere with CPY2D6 to varying degrees, with Paxil being the most potent of the SSRI's in this regard . (So potent that they actually call it "suicide inhibition".) Thus, use of Paxil makes tamoxifen less effective, attenuating the survival advantage imparted by tamoxifen use. (Note - Not all women are inherently able to optimally metabolize tamoxifen to its active metabolites, and research suggests that so called slow metabolizers of tamoxifen may have worse breast cancer outcomes. Genotyping for CYP2D6 variation may prove to be a useful genetic marker for tailoring of cancer treatment in this group.)Another expected finding of the study was that women taking Venlafaxine (Effexor) had a reduced risk of breast cancer deaths. Venlafaxine is used to treat the hot flashes associated with tamoxifen use, and women who have hot flashes while using tamoxifen may have better survival, probably because the hot flashes are a good sign that the Tamoxifen is being activated to Endoxifen. So this group would be selected to have better survival from the start, and the use of a weak CYP2D6 inhibitor doesn't appear to impede this survival advantage within the study group.What was unexpected in the study results was that fluoxetine (Prozac), another known potent inhibitor of CYP2D6, was not associated with an increase death risk compared to the other less potent CYP2D6 inhibitors. The researchers warn, however, that this may be due to the relatively small numbers of women on this drug in their population. "We want to be careful that this study is not used to bless the use of fluoxetine in tamoxifen users", says Dr Juurlink.A few more notes on study designGiven the robustness of the data sets they had, which appear to include both cancer registry and hospital records, it's a shame that the researchers did not have information on breast cancer stage, a critically important potential confounding factor. It's a huge limitation of the study that they acknowledge in the paper.I also found it odd that the researchers chose only to compare the SSRI's to one another, without having a control group of tamoxifen users not taking an SSRI. Juurelink explained that this was a deliberate choice, to avoid potential unknown variables that would affect mortality and be associated with the need to use antidepressants.Importance of Drug-Drug InteractionsWe were first clued in to the potential interactions between SSRI's and tamoxifen in 2005, when a landmark paper was published in JNCI on the pharmacologic interactions of these two classes of drugs. Since them, several other pharmacologic studies have confirmed the interactions and clarified which SSRI's are problematic and which are not, and concomitant use of the more potent PYP2D6 inhibitors has decreased. In 2009, a paper presented at the American Society of Clinical Oncology reported that women who used a potent or moderate CYP2D6- inhibiting SSRI (paroxetine, fluoxetine or serttraline) in conjunction with tamoxifen had a two-fold increase in breast cancer recurrence compared to use of weakly-inhibiting SSRI's (citalopran, escitalopram and fluvoxamine). This BMJ study is the first to report an increase in breast cancer mortality resulting from these interactions.Enormous credit goes to those who first suspected this interaction between SSRI's and Tamoxifen, did the excellent research to confirm it, and then went the extra mile to help identify which SSRI's are safe to use with tamoxifen and which are best to avoid. Treatment of depression in cancer patients can be critical to both their physical as well as emotional recovery, and it's important that we continue to have options that are effective for depression without interfering with cancer treatment. What should you do if you are on an SSRI and Tamoxifen?First of all, DO NOT suddenly stop your SSRI, since severe withdrawal symptoms can occur. DO talk to your doctor about which SSRI medication you are taking. If it is paroxetine or fluoxetine, it is recommended that you try to change to an SSRI that is a less potent or non-inhibitor of tamoxifen metabolism._____________________________________________________________Kelly, C., Juurlink, D., Gomes, T., Duong-Hua, M., Pritchard, K., Austin, P., & Paszat, L. (2010). Selective serotonin reuptake inhibitors and breast cancer mortality in women receiving tamoxifen: a population based cohort study BMJ, 340 (feb08 1) DOI: 10.1136/bmj.c693Photo licensed from Istockphoto.com... Read more »
Kelly, C., Juurlink, D., Gomes, T., Duong-Hua, M., Pritchard, K., Austin, P., & Paszat, L. (2010) Selective serotonin reuptake inhibitors and breast cancer mortality in women receiving tamoxifen: a population based cohort study. BMJ, 340(feb08 1). DOI: 10.1136/bmj.c693
One of the most important characteristics to be considered about the Influenza, in the preparation for pandemics, is the rearrangement. A mixture of genes of two or more different viruses is able to generate a new variety. Such as the new Influenza A (H1N1).
Although the mutations have an important role in the diversity of the [...]... Read more »
It is quite clear that for athletes, consuming protein and carbohydrate after a workout is crucial to recovery for subsequent sessions (replenish glycogen) and performance improvement. The doses of each macronutrient, as well as the inclusion of fat (which according to preliminary evidence, certain types of fat may further increase protein synthesis, and fat for [...]... Read more »
Newsom SA, Schenk S, Thomas KM, Harber MP, Knuth ND, Goldenberg N, & Horowitz JF. (2009) Energy deficit after exercise augments lipid mobilization but does not contribute to the exercise-induced increase in insulin sensitivity. Journal of applied physiology (Bethesda, Md. : 1985). PMID: 20044472
Yesterday I mentioned that a key aspect of fighting AIDS is staying on the drug regimen. Charles pointed out that this is more difficult than it might seem: the drugs are constant reminder of your condition, and taking them can revive horrible memories.
But how important is it to maintain adherence to the regimen? A 2008 [...]... Read more »
Bisson, G., Gross, R., Bellamy, S., Chittams, J., Hislop, M., Regensberg, L., Frank, I., Maartens, G., & Nachega, J. (2008) Pharmacy Refill Adherence Compared with CD4 Count Changes for Monitoring HIV-Infected Adults on Antiretroviral Therapy. PLoS Medicine, 5(5). DOI: 10.1371/journal.pmed.0050109
by amiya in Physiology physics woven fine
Mobile phones have drastically transformed our lives. Also known as cellular phones or cell phones, these gadgets not only incorporate a phone, as the name suggests, but also a lot of other technologically advanced features. They include a camera, a sound recorder cum music system, a Bluetooth device and many more depending on the model and the maker of the phone. They are called mobile phones since they can be used while on the move.A mobile phone maintains a two way (transmit and receive) communication with the nearby tower within a cell. Even when you are not talking on your mobile, it is constantly in touch with its ‘cell’. A cell may be thought of as the operational unit of a ‘base station’. A city or area may be likened to a bee hive, each hexagon representing a ‘cell’ having its own tower. As you move from one honeycomb to other, your mobile will change contact from one tower to another (another cell).Cell phones radiate high frequency (hence, microwave, as wavelength is inversely proportional to the frequency) electromagnetic radiation as a means of communication. One could easily demonstrate this electromagnetic emanation by putting a mobile flashing sticker close to a phone when it’s being used. This radiation can pierce our body tissues, particularly the head. But they could also microwave our scrotum if we keep them inside our pant pocket, as the phone is constantly in touch with the tower and emitting radiation unceasingly.The rapidly alternating electromagnetic field makes the polar molecules in our body move back and forth, as a tiny magnetic compass would move if the external magnetic field was allowed to change. This molecular movement results in heating of the tissues. Scientists were curious if this could harm us.Previously, it was thought that they could cause brain cancer but it was later found out that there was no significant relationship. There were some unconfirmed reports suggesting an association between mobile phone usage and an increase in the incidence of acoustic neuroma, a benign tumor of auditory nerve. The thermal effects arising out of the to-and fro effects of the polar molecules could give rise to the increased production of a class of proteins, called ‘heat shock proteins’ or stress proteins.Some drugs (like glucocorticoids, estrogen and progesterone) enter inside the cells where they combine with molecules called receptors, in the cytosol. This drug-receptor complex then translocates to the nucleus and commands the DNA into producing protein molecules by transcription. The resulting proteins typically account for the actions of these steroidal drugs. Heat shock proteins (like Hsp90) cover the DNA binding domain of the cytosolic receptors, preventing interaction with the DNA. When a steroid molecule attaches with the receptor, a conformational change occurs in the receptor releasing the Hsp, thereby freeing the DNA binding domain. Naturally, more stress proteins would mean more blocking of steroid receptors.Studies have also shown that microwave radiation at doses considered harmless caused DNA damage after two hours of exposure. All these led authorities in some countries advice Bluetooth usage and to keep your head away from your mobile. Read the next few lines if you really should keep your head away!Having said all those, let me state that the WHO, the American Cancer Society and the National Institute of Health have concluded that there was no scientific evidence that cell phone use had any adverse health risks.A University of South Florida research team wanted to find out any association of Alzheimer’s disease with cell phone usage. In the past, several studies have hinted at a possible increased risk of Alzheimer’s disease in humans with low frequency electromagnetic radiation, such mains power line frequency. But as they went on with their research, they were surprised at what they saw.They employed about 100 mice and subjected them to a daily radiation of 1 hour by an antenna that was kept in the center of the cage as shown. Some of these mice were 2 month old, which were genetically programmed to develop Alzheimer's disease like symptoms and signs with age; and some 4 month old, which already had the symptoms. They also placed normal healthy mice in the same cage. The electromagnetic field was made to emulate the radiation received by a man as he talked on his mobile phone and the wavelength was the same as that of the mobile phones. The mice’s memory was checked by maze tests.They were astonished to find that the electromagnetic field (EMF) not only boosted memory in both healthy and transgenic mice (compared to other mice who did not receive radiation) but also they actually reversed symptoms of Alzheimer’s. EMF seemed to break up tell-tale beta-amyloid plaques, a histopathologic marker of Alzheimer’s disease in mice which already expressed them. There was no evidence of increased tumour/cancer formation, DNA damage or behavioral changes.While what exactly cleared the plaques was not certain, but to quote Gary Arendash of the University of Southern Florida: "One thing is clear, however -- the cognitive benefits of long-term electromagnetic exposure are real”. Arendash also wondered if the preferential use of one of our ears in holding the phone could have asymmetric outcomes in the brain in terms of the plaques. He also observes: "It might also be useful in traumatic brain injury, which is also characterised by plaques, or just to improve cognitive performance”While it’s too premature to use your phone too close to your head to get a boost in your exams in the near future, its possible use as a “nootropic” is certainly encouraging.Mobile phones have a lot of other usable paraphernalia, some of which I pointed earlier. These features and the availability of inexpensive high-efficiency light emitting diodes (LEDs) inspired Breslauer et al to construct a microscope that would be helpful in developing countries.They have developed a high-resolution microscope attachment that is meant for camera- phones (picture on the left; click to enlarge). Their microscope can capture colour images of the malignant malaria causing parasite Plasmodium falciparum, red blood cells sickling in peripheral blood smear in homozygous sickle cell anemia (hemoglobin SS ) using brightfield microscopy. When fluorescence microscopy was performed with the sputum of tuberculosis patients using Auramine-O stain, the device captured Mycobacterium tuberculosis as well. The resolution was sufficient for the identification of single TB bacterium. The contraption was also good enough to highlight the rod shaped morphology of the acid-fast aerobic bacteria. In addition, epidemiological studies could be easily performed given that the individual mobile cells had their own identification codes and was under GPS location monitoring.Thus, we can create a cheap and efficient brightfield and fluorescent microscope out of a simple mobile phone (they used Nokia N73 camera phones, equipped with a 3.2 megapixel CMOS camera) and some easy to obtain components. To end up, there seems to be more to cheer than fear.Last modified: neverReferences:... Read more »
Gary W. Arendash, Juan Sanchez-Ramos, Takashi Mori, Malgorzata Mamcar, Xiaoyang Lin, Melissa Runfeldt, Li Wang, Guixin Zhang, Vasyl Sava, Jun Tan.... (2010) Electromagnetic Field Treatment Protects Against and Reverses Cognitive Impairment in Alzheimer's Disease Mice . Journal of Alzheimer's Disease, 191-210. info:/
Yesterday a couple of colleagues were talking about balance in life, and making it plain that they think people who spend a lot of time and energy on their work are sad. Their opinion? Work is the means to pay for your ‘real’ life, to spend more on working means less on what is really [...]... Read more »
MCCRACKEN, L., & VOWLES, K. (2007) Psychological Flexibility and Traditional Pain Management Strategies in Relation to Patient Functioning With Chronic Pain: An Examination of a Revised Instrument. The Journal of Pain, 8(9), 700-707. DOI: 10.1016/j.jpain.2007.04.008
GUTIERREZ, O., LUCIANO, C., RODRIGUEZ, M., & FINK, B. (2004) Comparison between an acceptance-based and a cognitive-control-based protocol for coping with pain*. Behavior Therapy, 35(4), 767-783. DOI: 10.1016/S0005-7894(04)80019-4
If there is one aspect of "complementary and alternative" medicine (CAM) that can puzzle advocates of science-based medicine, it's why, given how nonsensical much of it is given that some of it actually goes against the laws of physics (think homeopathy or distance healing), CAM is so popular. Obviously one reason is that there are conditions for which SBM does not have any "magic bullet" treatments. Diabetes, heart disease, other chronic illnesses, SBM can manage them quite well, but it can't cure them. Then there are conditions that science doesn't understand very well, conditions like, for example, fibromyalgia. It would be less than honest of me (or any other supporter of SBM) not to acknowledge that SBM sometimes has little to offer some patients. Of course, there's no evidence that CAM has anything therapeutic or concrete to offer these patients either, although certainly CAMsters would like you and their other marks to believe that they do.
Actually, that may not be entirely accurate. There does appear to be something that CAMsters offer patients that we practitioners of SBM appear to have a problem providing. It's unfortunate that this is true, but it does appear to be, and what it is should be fairly easy to guess. Basically, it's time. Anecdotally, most of us who pay attention to the issue of CAM and the infiltration of pseudoscience into medicine have suspected this, but there hasn't been a lot of data one way or the other to determine whether this is indeed the case and, if so, what the difference is. Last week, however, Dr. RW pointed me to a study that takes a stab at answering that very question. Published by a Dutch group, the study examined the practices of conventional physicians and CAM practitioners in terms of diagnoses seen and time spent with patients. The CAM practitioners included physicians practicing homeopathy, acupuncture, and naturopathy. A total of 5919 visits in 1839 patients were studied for diagnoses and time spent with each patient. These data were then compared with data from general practitioners (GPs) participating in the second Dutch national study in general practice (DNSGP-2). One result of this study was not surprising: Read the rest of this post... | Read the comments on this post...... Read more »
Heiligers, P., de Groot, J., Koster, D., & van Dulmen, S. (2010) Diagnoses and visit length in complementary and mainstream medicine. BMC Complementary and Alternative Medicine, 10(1), 3. DOI: 10.1186/1472-6882-10-3
The strongest evidence exists for Broadman Area 25 in the subcallosal cingulate gyrus (SCG) as target for deep brain stimulation in treatment resistant depression. This area in the brain is depicted in the figure above and is from the most important publication about DBS and depression in Neuron march 2005 by Helen Mayberg. Functional neuroimaging [...]
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Hamani, C., Mayberg, H., Snyder, B., Giacobbe, P., Kennedy, S., & Lozano, A. (2009) Deep brain stimulation of the subcallosal cingulate gyrus for depression: anatomical location of active contacts in clinical responders and a suggested guideline for targeting. Journal of Neurosurgery, 111(6), 1209-1215. DOI: 10.3171/2008.10.JNS08763
A 7 year-old girl was brought to hospital with lethargy, irritability and vomiting. A week previously she developed chicken pox, and was treated with regular aspirin and paracetamol for fever and discomfort.... Read more »
Glasgow JF, & Middleton B. (2001) Reye syndrome--insights on causation and prognosis. Archives of disease in childhood, 85(5), 351-3. PMID: 11668090
Schrör K. (2007) Aspirin and Reye syndrome: a review of the evidence. Paediatric drugs, 9(3), 195-204. PMID: 17523700
With a departmental initiative to hire new tenure-track neuroscientists/psychopathologists, I highlight today's job seminar given by Dr. Jilla Sabeti of The Scripps Institute and attach her respective paper. ... Read more »
Sabeti, J., & Gruol, D. (2008) Emergence of NMDAR-independent long-term potentiation at hippocampal CA1 synapses following early adolescent exposure to chronic intermittent ethanol: Role for sigma-receptors. Hippocampus, 18(2), 148-168. DOI: 10.1002/hipo.20379
I've been working on fitting some excess relative risk (ERR) models to case-control data on occupational exposures lately. ERR models are of the form:RR=1+β*XIn SAS, unfortunately, we don't have unlimited freedom in defining the form of the model we want to fit, but a recent paper by Langholz and Richardson [behind firewall] describes a way that we can solve for parameters once we specify the likelihood function. (For those interested, the likelihood function can be thought of as the function that would be most likely to give rise to the data. We define it with some variables, and then try to solve for the variable(s) that maximize the likelihood function. This falls into the class of methods called maximum likelihood estimation.)The general conditional logistic likelihood is pretty simple (phi represents the odds or rate ratio function) :The best way to conceptualize this equation is as: divide the data you observed by all possible permutations of the data.This function is then maximized with respect to beta (for the mat-inclined, an iterative process minimizes the derivative of the log of the function to look for the global maximum).The method described by Langholz and Richardson makes use of a nifty little SAS procedure called PROC NLP (the NLP stands for non-linear programming). It basically does exactly what I just described: you can specify a function and host of parameters, and it will iteratively search for a maximum value of the function, and spit out the parameters that yield the maximum.A cool extension of this is that you can define complex "mixture models" that contain two distinct models that are each exponentiated: one to alpha, one to 1-alpha. You then multiply the two exponentiated models together. If you then maximize the likelihood, including the parameter alpha, you get a neat little value that tells you the relative importance of each of the two models in the full mixture model. For example:RR=[(βX)^α]*[(exp(βX))^(1-α)]PROC NLP lets you specify this model form and get an estimate of which model (linear or exponential) fits better, depending on whether alpha is closer to zero or one.Langholz, B., & Richardson, D. (2009). Fitting General Relative Risk Models for Survival Time and Matched Case-Control Analysis American Journal of Epidemiology, 171 (3), 377-383 DOI: 10.1093/aje/kwp403... Read more »
Langholz, B., & Richardson, D. (2009) Fitting General Relative Risk Models for Survival Time and Matched Case-Control Analysis. American Journal of Epidemiology, 171(3), 377-383. DOI: 10.1093/aje/kwp403
Some people just won’t do well with pain management. In just the same way as a surgeon selects good candidates for surgery, so people need to be selected for self management. Although there is some truth that getting even a little pain management is good for everyone, the cost of doing so in staff energy [...]... Read more »
Foster, N., Thomas, E., Bishop, A., Dunn, K., & Main, C. (2009) Distinctiveness of psychological obstacles to recovery in low back pain patients in primary care. Pain. DOI: 10.1016/j.pain.2009.11.002
McCracken, L., & Zhao-O’Brien, J. (2010) General psychological acceptance and chronic pain: There is more to accept than the pain itself. European Journal of Pain, 14(2), 170-175. DOI: 10.1016/j.ejpain.2009.03.004
Last Friday, Peter wrote a post about Wii-related injuries which generated some interesting discussion. Essentially, some readers felt that we were being too hard on the Wii, with one commenter going so far as to suggest that the post was "anti-Wii" (hard to dispute, given that the post was focused on Wii-related injuries!). Although we've mentioned the Wii in passing on Obesity Panacea before, we've never had a full discussion of the pros and cons, and I thought that this would be an excellent opportunity to do so. So - should we really consider the Nintendo Wii as a form of physical activity?... Read more »
Graves, L., Stratton, G., Ridgers, N., & Cable, N. (2007) Comparison of energy expenditure in adolescents when playing new generation and sedentary computer games: cross sectional study. BMJ, 335(7633), 1282-1284. DOI: 10.1136/bmj.39415.632951.80
Daley, A. (2009) Can Exergaming Contribute to Improving Physical Activity Levels and Health Outcomes in Children?. PEDIATRICS, 124(2), 763-771. DOI: 10.1542/peds.2008-2357
The Best Stretch for the Pectoralis Minor?
This post came about from some of the live Q&A that we had following my webinar last week on “assessing asymmetry in the overhead athlete – does asymmetry mean pathology?” (the webinar is now recorded and available for download if you couldn't make the live session). We discussed some asymmetries with the scapula and talked about stretching the pectoralis minor. I thought this would be...
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Borstad, J., & Ludewig, P. (2006) Comparison of three stretches for the pectoralis minor muscle. Journal of Shoulder and Elbow Surgery, 15(3), 324-330. DOI: 10.1016/j.jse.2005.08.011
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