Medicine posts

February 13, 2012
06:00 AM
13 views

Drinking Alcohol makes you pee more – but how much?

by Stuart Farrimond in Dr Stu's Science Blog

Too much tipple and you’ll know about it the next day. The dreaded hangover – headaches, fatigue and nausea are normal Sunday morning sensations for many a Saturday night reveller. Dehydration is frequently said to be the reason for hangover symptoms – and some swear that a pint of tap water before bed thwarts any alcohol-induced … Continue reading »... Read more »

Strauss, M., Rosenbaum, J., & Nelson, W. (1950) THE EFFECT OF ALCOHOL ON THE RENAL EXCRETION OF WATER AND ELECTROLYTE 1. Journal of Clinical Investigation, 29(8), 1053-1058. DOI: 10.1172/JCI102336

February 13, 2012
12:04 AM
9 views

Retention of Movement Pattern Changes After a Lower Extremity Injury Prevention Program Is Affected by Program Duration

by Jeffrey B. Driban in Sports Medicine Research (SMR): In the Lab & In the Field

Padua et al compared the retention of altered movement patterns between a short-duration (3 months) and extended-duration injury prevention program completed by youth soccer athletes (aged 11 to 17 years). ... Read more »

Padua DA, Distefano LJ, Marshall SW, Beutler AI, de la Motte SJ, & Distefano MJ. (2012) Retention of movement pattern changes after a lower extremity injury prevention program is affected by program duration. The American Journal of Sports Medicine, 40(2), 300-6. PMID: 22064608

February 12, 2012
01:45 PM
24 views

The Chimp that Could (almost) Talk

by Paige Brown in From The Lab Bench

“Wouldn’t it be exciting to communicate with a Chimp, and find out what it was thinking?” – Professor Herbert Terrace

I watched Project Nim tonight, an intriguing and emotional film about a scientific project that, to many, meant much more than scientific findings – the story of a chimpanzee taken from its mother at birth, raised like a human child, and taught to communicate using sign language.
... Read more »

Terrace, H., Petitto, L., Sanders, R., & Bever, T. (1979) Can an ape create a sentence?. Science, 206(4421), 891-902. DOI: 10.1126/science.504995

February 12, 2012
01:21 PM
22 views

Cell Phone Use and Risk of Brain Cancer

by William Yates, M.D. in Brain Posts

In my last post I examined the epidemiology of brain tumors using a summary of the latest data from the United States. The summary noted the slight decline in the number of malignant brain cancers over the last twenty years.One area of concern that is receiving increased attention is the potential for cell phone risk to raise the risk of brain cancers.Obviously if cell phone use was a very large effect one might have expected an increase in the rates of brain tumors and cancer over the last twenty years. This corresponding to the time when cell phone use has increased dramatically in the U.S. and around the world. Multiple case control studies have been completed examining this possible association and the majority of studies have not demonstrated a significant effect. One recent study from Frei in Denmark along with colleagues in France and Switzerland adds to the apparent safety of cell phones.The key design elements of the Frei study included:Study type: Cohort study using all individuals born in Denmark from April 1, 1968Study groups: Cell phone subscribers status (subscribers versus non-subscribers) was identified via phone records and linked to centralized health records containing health registry information including presence or central nervous system tumors.Confounding variables controlled: age, gender, education level, incomeOutcome variable: incidence rates ratio with 95% confidence interalThis data set included over 300,000 individuals with a cell phone subscription and a larger group of control individuals. The researchers grouped brain tumors into malignant gliomas, meningiomas (largely benign brain tumors) and a residual group of other brain tumor and cancer types.The analysis showed the incidence rates for cell phones subscribers did not statistically differ from those who did not differ from those without cell phone subscriptions in any brain tumor or cancer group.This is an important study. It represents a very large data set with comprehensive registry data that would be difficult to replicate in the United States health care system. The authors noted no specific increase in temporal lobe gliomas in the cell phone user group. This region of the brain would be the closest region to cell phone placement during calls and theoretically most likely to be affected if an association was present.The authors concluded: "a small to moderate increase in risk for subgroups of heavy users or after even longer induction periods than 10-15 years cannot be ruled out". Nevertheless, this study should reduce worry that cell phones users are significantly increasing their risk for brain tumors or cancer.Photo of male and female chachalaca pair from Bentsen Birding Center in Texas from the author's files.Frei, P., Poulsen, A., Johansen, C., Olsen, J., Steding-Jessen, M., & Schuz, J. (2011). Use of mobile phones and risk of brain tumours: update of Danish cohort study BMJ, 343 (oct19 4) DOI: 10.1136/bmj.d6387... Read more »

Frei, P., Poulsen, A., Johansen, C., Olsen, J., Steding-Jessen, M., & Schuz, J. (2011) Use of mobile phones and risk of brain tumours: update of Danish cohort study. BMJ, 343(oct19 4). DOI: 10.1136/bmj.d6387

February 12, 2012
11:10 AM
23 views

How the TB bacteria bursts your cells

by Lab Rat in Lab Rat Blog

The bacteria that causes Tuberculosis is a nasty little beast. The white blood cells that clear infection in your body work by ingesting bacteria and then breaking them up, and the TB escapes this by letting itself get ingested and then sitting inside your white blood cells. They don’t sit passively, however, they burst out of the cell and recruit a whole host of other blood cells which surround the infection and form what’s called a granuloma. The bacteria stay inside the granuloma and become dormant, but if they escape they can set up other sites of infection throughout the body.... Read more »

Simeone R, Bobard A, Lippmann J, Bitter W, Majlessi L, Brosch R, & Enninga J. (2012) Phagosomal Rupture by Mycobacterium tuberculosis Results in Toxicity and Host Cell Death. PLoS pathogens, 8(2). PMID: 22319448

February 10, 2012
04:24 PM
36 views

The role of the Androgen Receptor in breast cancer

by Sally Church in Pharma Strategy Blog

This week I have been in Orlando for the American Association for Cancer Research (AACR) Special Conference on prostate cancer chaired by Drs Arul Chinnaiyan (U. of Michigan) and Charles Sawyers (MSKCC). It was a superb meeting, probably one of … Continue reading →
... Read more »

Hu, R., Dawood, S., Holmes, M., Collins, L., Schnitt, S., Cole, K., Marotti, J., Hankinson, S., Colditz, G., & Tamimi, R. (2011) Androgen Receptor Expression and Breast Cancer Survival in Postmenopausal Women. Clinical Cancer Research, 17(7), 1867-1874. DOI: 10.1158/1078-0432.CCR-10-2021

February 10, 2012
03:40 AM
66 views

Good Science, Bad History, in the British Journal of Psychiatry

by Neuroskeptic in Neuroskeptic

The latest February 2012 issue of the British Journal of Psychiatry features a paper about the association between child abuse and later mental health problems. I haven't read it yet, but it looks pretty good.However, it also includes an editorial from John Read and Richard Bentall which argues that: Just 20 years ago, however, it would have been difficult to get the paper published. Mental health professions have been slow, even resistant, to recognise the role of childhood adversities in psychiatric disorder... Until very recently the hypothesis that abuse in childhood has a causal role in psychosis was regarded by many biologically oriented psychiatrists as heresy...Really? I checked the BJP from exactly 20 years ago. The February 1992 issue contained:A paper about child sexual abuse in female psychiatric patients.A letter praising a different article, on the same topic.A review of 11 studies on psychosocial family interventions as treatments for schizophrenia.A paper looking at the effect of the social environment on symptoms of schizophrenia.Four strikes and they're out. It's not true that this kind of thing wasn't being discussed 20 years ago.Such grandstanding is bad for science. Few would deny that psychiatry in recent years has undervalued psychosocial factors and overvalued genetics and neuroscience, but it's actually quite a complicated story, not a Punch and Judy show with bad guys on one side and good guys on the other.Rhetorical flourishes like this editorial certainly get attention but in the long run, down that road lies madness.Read, J., and Bentall, R. (2012). Negative childhood experiences and mental health: theoretical, clinical and primary prevention implications The British Journal of Psychiatry, 200 (2), 89-91 DOI: 10.1192/bjp.bp.111.096727... Read more »

Read, J., & Bentall, R. (2012) Negative childhood experiences and mental health: theoretical, clinical and primary prevention implications. The British Journal of Psychiatry, 200(2), 89-91. DOI: 10.1192/bjp.bp.111.096727

February 10, 2012
12:02 AM
36 views

The Benefits of Prehabilitation: Mobilizing Your Patient Before it’s too Late

by Joseph Zeni in Sports Medicine Research (SMR): In the Lab & In the Field

The authors in this paper evaluated the value of “prehabilitation” before knee replacement.... Read more »

Swank AM, Kachelman JB, Bibeau W, Quesada PM, Nyland J, Malkani A, & Topp RV. (2011) Prehabilitation before total knee arthroplasty increases strength and function in older adults with severe osteoarthritis. Journal of Strength and Conditioning Research, 25(2), 318-25. PMID: 21217530

February 9, 2012
10:38 AM
46 views

Immunoediting in Cancer by Exome Sequencing

by Daniel Koboldt in Massgenomics

Cancer immunoediting is a process by which the immune system controls the growth of nascent tumors and shapes their antigenic properties. It’s a sort of catch-22 of cancer biology; by protecting the host from development of cancer, the immune system ultimately selects for tumor cells that are resistant to its attack. Central to the concept [...]... Read more »

Matsushita, H., Vesely, M., Koboldt, D., Rickert, C., Uppaluri, R., Magrini, V., Arthur, C., White, J., Chen, Y., Shea, L.... (2012) Cancer exome analysis reveals a T-cell-dependent mechanism of cancer immunoediting. Nature. DOI: 10.1038/nature10755

DuPage, M., Mazumdar, C., Schmidt, L., Cheung, A., & Jacks, T. (2012) Expression of tumour-specific antigens underlies cancer immunoediting. Nature. DOI: 10.1038/nature10803

February 9, 2012
05:36 AM
66 views

Why parkin has scientists backing the future of Parkinson's research

by Andrew Watt in A Hippo on Campus

Back in the '80s the name Michael J. Fox was more or less interchangeable with that of Marty McFly, the effortlessly cool protagonist from the Back to the Future trilogy who introduced an entire generation of kids to hoverboards, self-lacing shoes and flux capacitors. Not to mention 'Johnny B Goode'. These days however Fox's name is more likely to have us thinking of his fight with Parkinson's disease, which he was diagnosed with back in 1991, or the advocacy work he does for his aptly named Michael J. Fox Foundation for Parkinson's Research. Looking at their mission statement you can't help but get the feeling that Fox has brought a little of Marty "nobody calls me chicken" McFly's fighting spirit to the Foundation as it dedicates itself to "finding a cure for Parkinson's disease through an aggressively funded research agenda". Whilst a cure remains allusive, recent research funded by the Foundation has resulted in a giant leap forward in our understanding of Parkinson's disease and suggests that the cure which Fox hopes will one day put him out of business may not be as far off as once thought.It all starts in the basal gangliaClinically, Parkinson's disease (PD) is characterised by an array of motor symptoms including tremors, rigidity, slowness of movement (or bradykinesia) and gait and walking difficulties. Symptoms which are thought to result from neuronal degeneration within the substantia nigra, a small region of the basal ganglia which acts to produce and release the neurotransmitter dopamine. The basal ganglia is a highly organised group of structures located at the base of the forebrain which exerts a constant inhibitory effect on our various motor systems. An effect which helps to prevent our bodies from becoming inappropriately active. And that's where dopamine comes in. The dopamine, produced by the substantia nigra, acts to facilitate the release of the basal ganglia's inhibitory influence, and thus allows movement to occur. It might be easier to think of the motor system as a somewhat fused set of gears attached to a small motor. Despite the motor (motor system) being active the friction (basal ganglia) is too great to allow the gears to turn. The friction can however be overcome by spraying a small amount of lubricant (our dopamine in this analogy) onto the gears, thus whilst the dopamine doesn't actively turn the gears it acts to reduce the constant friction between the gears thus allowing the motor to initiate movement. Our brains work in much the same way, everything is able to work smoothly in the presence of our personal lubricant, dopamine (sounds wrong I know but stick with me here), however when sufficient levels of dopamine are not available, such as in Parkinson's disease, our ability to initiate and control our movements slowly grinds to a halt.Like most neurodegenerative conditions, the neuronal loss associated with Parkinson's disease occurs due to a variety of factors, some of which are environmental whilst others are genetic. However, as is often the case, it is the rarer genetic forms of the disease which offer the greatest promise for therapeutic advancement in the field. Approximately one in 10 Parkinson's cases result from mutations in the parkin gene, a gene on chromosome six which encodes a component of the E3 ubiquitin ligase complex (for those of you playing at home). Normally this knowledge would result in the use of a mouse model of the disease, however parkin knockout mice show no signs of Parkinson's disease suggesting that parkin mutations act selectively on human nigral dopaminergic neurons. The selective nature of the parkin gene was, until recently, a major hurdle in Parkinson's research as the complexity of neuronal networks in the human brain make it incredibly difficult to study the genetic form of the disease. After all parkin-affected dopaminergic human neurons aren't something you can just grow in a lab. Or at least they weren't, until now.Test tube neuronsThat's right for the first time ever scientists have managed to generate human dopaminergic neurons from Parkinson's disease patients with parkin mutations. And what's more they made them from skin. Ok so to be more specific the researchers generated human induced pluripotent stem cells from dermal fibroblasts (skin cells), collected from two Parkinson's patients (both with parkin mutations) and two controls. The stem cells were subsequently used to generate the dopaminergic neurons some of which contained the parkin mutations and some of which did not. The generation of these mutant neurons allowed the researchers to finally observe parkin in action in its native habitat, and enabled them to see just how mutations in the gene were leading to neuronal damage. As it would turn out normal parkin acts to control the production of monoamine oxidase, or MAO for short, an enzyme which acts to catalyse dopamine oxidation. The production of MAO is normally tightly controlled to ensure that adequate levels of dopamine are being oxidised and our movements are able to all run smoothly. However when parkin mutations occur, the tight control of MAO production is lost and MAO is expressed at much higher levels. But what's the big deal? Surely there's nothing wrong with a bit of extra MAO floating around the place. After all it just means we'll have some MAO for a rainy day, right? Wrong. As it would happen MAO production is generally tightly controlled for a very good reason. It's toxic! Yep, at high levels MAO leads to the degeneration of our dopaminergic neurons as a result of oxidative stress. And no amount of shiraz-based anti-oxidants can do anything about it. But whilst shiraz may not work, it turns out that restoring control over MAO production does, as lead author Houbo Jiang and his team found that the early-stage damage could be reversed by delivering normal parkin back into the cells. As well as providing insight into the role parkin plays in genetic forms of the disease, these findings also provide a novel target for future Parkinson's treatments. MAO production. Whilst one of the drugs currently on the market acts to inhibit MAO activity, there are no therapies which attempt to restore control over MAO production. At least not for the time being. So with the hope these findings seem to be injecting into the field of Parkinson's research, you can't help but get the feeling that if Marty McFly were reading this now he'd smile and say 'if only they knew, there's just a few short years to go'. And I for one am hoping he's right. SourcesJiang, H., Ren, Y., Yuen, E., Zhong, P., Ghaedi, M., Hu, Z., Azabdaftari, G., Nakaso, K., Yan, Z., & Feng, J. (2012). Parkin controls dopamine utilization in human midbrain dopaminergic neurons derived from induced pluripotent stem cells Nature Communications, 3 DOI: 10.1038/ncomms1669... Read more »

Obeso JA, Rodríguez-Oroz MC, Benitez-Temino B, Blesa FJ, Guridi J, Marin C, & Rodriguez M. (2008) Functional organization of the basal ganglia: therapeutic implications for Parkinson's disease. Movement disorders : official journal of the Movement Disorder Society. PMID: 18781672

February 9, 2012
12:02 AM
54 views

Baseline Neurocognitive Test Performance and Symptoms may be Influenced by Depression

by Jane McDevitt in Sports Medicine Research (SMR): In the Lab & In the Field

The objective of this study was to examine depression and baseline neurocognitive function and concussion symptoms in male and female high school and college athletes.... Read more »

Covassin T, Elbin RJ 3rd, Larson E, & Kontos AP. (2012) Sex and Age Differences in Depression and Baseline Sport-Related Concussion Neurocognitive Performance and Symptoms. Clinical Journal of Sport Medicine. PMID: 22246342

February 8, 2012
10:12 AM
44 views

Is Medical Reporting Making the Grade?

by Arielle D. Ross in Salamander Hours

The quality of scientific reporting, especially of medical reporting, is of great import to the public, but that is only one reason among many to care about media coverage quality. False or sub-quality reporting can lead to inaccurate beliefs, … Continue reading →... Read more »

Schwartz, L., Woloshin, S., Andrews, A., & Stukel, T. (2012) Influence of medical journal press releases on the quality of associated newspaper coverage: retrospective cohort study. BMJ, 344(jan27 1). DOI: 10.1136/bmj.d8164

February 8, 2012
07:44 AM
56 views

Deceiving Degrees

by E Markham in Genetic Cuckoo

Discussion of the recent change to courses offered in British universities following increased awareness and protest against pseudoscience, with more universities choosing to no longer offer degrees in homeopathy and alternative medicine, it seems evidence based medicine is finally eradicating flimflam from our higher institutions. However, this is not the situation in much of the world, as many leading universities in Australia still offering these misleading and pointless courses. This article highlights the change within the British universities, following more scrutiny form students and parents alike for the quality of university courses in the wake of the rises in tuition fees.... Read more »

E Markham. (2012) Deceiving Degrees. Blogspot. info:/

February 8, 2012
03:33 AM
72 views

Visualizing The Connected Brain

by Neuroskeptic in Neuroskeptic

So it seems as though the "connectome" is the latest big thing in neuroscience. This is the brain's wiring diagram, in terms of the connections between neurons and on a larger scale, between brain regions.We certainly won't understand the brain without getting to grips with the connections but equally, it's not the whole story. I previously emphasised that the brain is not made of soup; it's not made of spaghetti, either.Connectomics does however unquestionably provide some of the prettiest images in neuroscience. And they just got prettier, with a new technique for visualizing connections, just revealed in Neuroimage: Circular representation of human cortical networks for subject and population-level connectomic visualization.See above. It's a rather lovely vista (for which the authors Irimia et al share credit with the folks behind the Circos visualization tool they used).All you need are some MRI scans, and a lot of image processing, and you can produce one of these "Connectograms". But what does it mean? Here's the authors' description:The outermost ring shows the various brain regions arranged by lobe (fr — frontal; ins — insula; lim — limbic; tem — temporal; par — parietal; occ — occipital; nc — non-cortical; bs — brain stem; CeB — cerebellum) and further ordered anterior-to-posterior. The color map of each region is lobe-speciﬁc and maps to the color of each regional parcellation.In other words, the outer ring is just a list of brain regions, each with an assigned colour. The inner rings tell us about those regions: Proceeding inward towards the center of the circle, these measures are: total GM volume, total area of the surface associated with the GM–WM interface (at the base of the cortical ribbon), mean cortical thickness, mean curvature and connectivity per unit volume. For non-cortical regions, only average regional volume is shown.So each of the five inner rings displays data about one aspect of brain anatomy, for each of the regions. The colors are a heat map of the numbers.Finally, the lines between regions represent the degrees of connectivity between regions via white matter tracts, as measured with diffusion tensor imaging:The links represent the computed degrees of connectivity between segmented brain regions. Links shaded in blue represent DTI tractography pathways in the lower third of the distribution of FA, green lines the middle third, and red lines the top third (see text for details). You can also make a pooled connectogram of the average neuroanatomy across a group of people. Still, it remains to be seen whether these are as useful as they are beautiful.Irimia A, Chambers MC, Torgerson CM, and Van Horn JD (2012). Circular representation of human cortical networks for subject and population-level connectomic visualization. NeuroImage PMID: 22305988... Read more »

Irimia A, Chambers MC, Torgerson CM, & Van Horn JD. (2012) Circular representation of human cortical networks for subject and population-level connectomic visualization. NeuroImage. PMID: 22305988

February 8, 2012
12:04 AM
38 views

Return to Sport Following ACL Reconstruction Surgery - How Many Athletes Return to Preinjury Levels?

by Nicole Cattano in Sports Medicine Research (SMR): In the Lab & In the Field

Anterior cruciate ligament (ACL) reconstruction is often performed in an effort for an athlete to return to sporting activity. General outcomes are successful, but it remains unclear how many people return to play and participate at their preinjury levels. This study was a systematic review with the purpose to determine return-to-sport outcomes (e.g., return to participation at preinjury levels) after ACL surgery.... Read more »

Ardern CL, Webster KE, Taylor NF, & Feller JA. (2011) Return to sport following anterior cruciate ligament reconstruction surgery: a systematic review and meta-analysis of the state of play. British Journal of Sports Medicine, 45(7), 596-606. PMID: 21398310

February 7, 2012
09:39 AM
43 views

Finding the cause of Liam’s metabolic disease

by Guest Blogger in Beaker

Dr. Hudson Freeze and colleagues are using whole-exome sequencing to diagnose severe metabolic diseases.... Read more »

Jones MA, Ng BG, Bhide S, Chin E, Rhodenizer D, He P, Losfeld ME, He M, Raymond K, Berry G.... (2012) DDOST Mutations Identified by Whole-Exome Sequencing Are Implicated in Congenital Disorders of Glycosylation. American journal of human genetics. PMID: 22305527

February 7, 2012
04:00 AM
71 views

Thoughts on World Cancer Day: Part I–Unraveling Yuvraj Singh’s Cancer

by Pranab Chatterjee in Scepticemia

Sorry for missing the train on this one. February 4th is the World Cancer Day and is one of the public health days that could do with some more propaganda in the public eye. I was so caught up with work and studies it just passed me by and I could not even get the [...]... Read more »

Bokemeyer C, Droz JP, Horwich A, Gerl A, Fossa SD, Beyer J, Pont J, Schmoll HJ, Kanz L, Einhorn L.... (2001) Extragonadal seminoma: an international multicenter analysis of prognostic factors and long term treatment outcome. Cancer, 91(7), 1394-401. PMID: 11283942

February 7, 2012
12:02 AM
66 views

Benefits of Spinal Manipulation or Home Exercise vs Medication for Neck Pain

by Kris Fayock in Sports Medicine Research (SMR): In the Lab & In the Field

Bronfort et al tested the effectiveness of spinal manipulation therapy (SMT), medication, and home exercise with advice (HEA) for acute and sub-acute neck pain.... Read more »

Bronfort G, Evans R, Anderson AV, Svendsen KH, Bracha Y, & Grimm RH. (2012) Spinal manipulation, medication, or home exercise with advice for acute and subacute neck pain: a randomized trial. Annals of Internal Medicine, 156(1 Pt 1), 1-10. PMID: 22213489

February 6, 2012
11:40 AM
115 views

Exome-based Copy Number Analysis with VarScan 2

by Daniel Koboldt in Massgenomics

Now online at Genome Research is the publication of VarScan 2, our in-house algorithm for simultaneous detection of somatic mutations and copy number alterations using exome sequence data from matched tumor-normal pairs. There are a number of reasons why exome-based copy number alteration (CNA) detection should not work. The hybridization process introduces biases, both between [...]... Read more »

Koboldt DC, Zhang Q, Larson DE, Shen D, McLellan MD, Lin L, Miller CA, Mardis ER, Ding L, & Wilson RK. (2012) VarScan 2: Somatic mutation and copy number alteration discovery in cancer by exome sequencing. Genome research. PMID: 22300766

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