More good bacteria

Not all bacteria are bad, as we know. There are "good bacteria" that live in our gut and help us to digest our food. Now, bacteria have been harnessed to help doctors and clinicians as a vector to treat or prevent disease. This bacterial gene therapy is known as "bactofection".

Peter Celec and his team in the Slovak Republic researched the usage of bacteria to treat inflammatory bowel disease.¹ The Salmonella bacteria carried genes for an antioxidant (superoxide dismutase) and a protein that stimulates the immune response (monocyte chemoattractant protein-1). Bactofection was applied to mice suffering from inflammatory bowel disease (colitis), and alleviated colitis symptoms in these mice when compared to untreated mice.

Listeria has been tested as a vector to deliver therapeutic genes and proteins to cancer cells and immune cells.² Listeria is a particularly good candidate as it is very efficient at entering host cells, and can move from cell to cell without having to exit it anywhere. Moreover it is safe and effective in clinical trials. Anti-cancer genes can be targeted to tumours by packaging them inside this pathogen.


Salmonella has also been used as a vehicle to treat cancer. ³ Both Listeria and Salmonella infect and can survive in antigen presenting cells (cells that form part of the immune system). They can be engineered to express tumour-like proteins which stimulates the body's immune system to break tolerance against tumour cells that look a lot like "self" to the body.



Image: Salmonella enterica serovar typhimurium



¹Palffy R, Gardlik R, Behuliak M, Jani P, Balakova D, Kadasi L, Turna J, Celec P. Salmonella-mediated gene therapy in experimental colitis in mice. Exp Biol Med (Maywood). (2011) 236:177-83.

²Tangney M, Gahan CGM. Listeria monocytogenes as a Vector for Anti-Cancer Therapies. Current Gene Therapy (2010) 10: 46-55.

³Paterson Y, Guirnalda PD, Wood LM. Listeria and Salmonella bacterial vectors of tumor-associated antigens for cancer immunotherapy. Seminars in Immunology (2010) 22: 183-189.

Gold nanocages

Prof. Younan Xia and his team invented gold nanocages (see below) for therapeutic applications. In a review¹ published in 2010, he explained how gold nanoparticles have gained an increasing interest due to their plasmonic characteristics. In particular, the metal can convert light into heat. This heat can be used for different applications, such as selectively releasing the drug contents of the nanocarriers once they have reached their target, or for photothermal therapy, where the heat generated by the nanoparticles destroy the cancer cells to which they are targeted.










¹Cobley CM, Au L, Chen J, Xia Y. Targeting gold nanocages to cancer cells for photothermal destruction and drug delivery. Expert Opin Drug Deliv. 7: 577-87 (2010)

The spirit is willing but the flesh is weak

If you're struggling to lose weight, it might actually be due to a chemical imbalance in your brain.

Researchers at the National Institutes of Health have shown that some obese individuals might have differences in the reward areas of the brain, compared to non-obese individuals.¹ The ability to resist the urge to eat needs to be stronger than the expected feeling of reward when we do eat. Some people seem to have an impairment in the brain area associated with reward sensitivity, and therefore their willpower is overwhelmed by the need to get that food reward.

[I wish this paper were open access as I'd love to know whether the researchers think one could break the conditioned response!]


¹Volkow ND, Wang GJ, Baler RD. Reward, dopamine and the control of food intake: implications for obesity. Trends Cogn Sci. 15:37-46 (2011).

Placebos as medicine

Did you know that your doctor may be giving you a placebo for your niggle? Well they very well may be. Antibiotics for flu? There you have one example already.

A recent survey was done by Kermen and co-workers¹ to determine how frequently American physicians prescribe placebos.Fifty-six percent (56%) of surveyed physicians reported prescribing or administering placebos in their practices, with younger physicians being a lot more likely to prescribe placebos than older physicians. The most frequently-used placebo was antibiotics (for non-bacterial diagnoses, 40%). The second most frequently prescribed placebo was vitamines (23%), followed by herbal supplements (12%). The most common reasons for prescribing placebos were “unjustified demand for medication” (32%) and “to calm patients” (21%). Most physicians (31%) told their patients that their presription consisted of a substance that will help and not hurt, and a very honest 2% told their patients that what they were given was an actual placebo. Most physicians believe that the placebo effect is beneficial and can have real, positive results.

So, while most physicians "believe" in the placebo effect, only about half would prescribe a substance that they knew had no direct therapeutic ingredient. Of course this was a very small study, but it makes one wonder what's happening in one's own surgery. It also reiterates the strong effect that thoughts can have on health.

¹ Kermen R, Hickner J, Brody H, Hasham I. Family physicians believe the placebo effect is therapeutic but often use real drugs as placebos. Fam Med. 42:636-42 (2010)
Source

Christmas special: the weird and the wonderful

In the process of looking for hot new research topics (or just in the course of my daily working day) I find a fair amount of curious papers. So, as a final entry for the year I thought I'd post a special edition, listing a few of my favourites.

From the department of Advanced Medical Science (literally)¹:

"Obesity significantly increases the difficulty of patient management in the emergency department."

With the objective to "... determine which aspects of ED management are adversely affected by patient obesity, to determine the level of obesity above which management is made more difficult and to make recommendations on how these effects might be mitigated...", this study showed that patient obesity makes it difficult to manage an emergency department. And offered no solutions.


Ever wondered if watching TV or working on your computer late at night affects your sleep? So did a couple of researchers in Brazil who investigated the "Quality of sleep among university students: effects of nighttime computer and television use."²

The internet lost out in this study as it seems to affect sleep a lot more than television. Interestingly, if you manage to use the internet untill 3am, you sleep a bit better. This blogger wonders how much of the "affected sleep" is due to online arguing...



The title of this paper says it all, really: PMS: premenstrual storm? An unusual cause of electrical storm in a young woman with vasospastic angina. ³
Never underestimate how hard it is to be a girl...



Apparently "Hearing loss in stranded odontocete dolphins and whales" ⁴ is a big problem. Researchers speculate that this may have somethig to do with the actual stranding. How do you measure hearing in a dolphin? Well, with great difficulty, but apparently "in all cases, a jawphone consisting of an ITC-1042 piezoceramic transducer embedded in a RTV silicone suction cup was placed on the lower jaw fat pad to deliver sound stimuli." If a response could be detected from the dolphin or whale, then that was marked as the level at which the animal could "hear". There was a strong correlation between stranding and hearing loss in some of the species. (Picture below: a hydrophone)




The brushtail possum is a major pest species of New Zealand. Some researchers are investigating a nanoparticle system containing a chemical sterilitant which could be used orally to control their numbers.⁵ Poor little possums.




Our last two entries are shamelessly of a scatological nature:

A woman with a history of depression presents with abdominal bloating. Her doctor sends her for a colonoscopy. It turns out she's fine, but they do find something odd. A cockroach. ⁶


And finally... Apparently "robotic assisted laparoscopic radical prostatectomy" is a fairly uncomfortable procedure used in prostate cancer. So a few researchers in Seattle wondered whether a suppository containing belladonna (that's deadly nightshade to me and you) and opium would help.⁷ And indeed it did! With no adverse events noted either!





¹ Kam J, Taylor DM. Emerg Med Australas. 2010 Aug;22(4):316-23. Source

² Mesquita G, Reimão R. Arq Neuropsiquiatr. 2010 Oct;68(5):720-5. Source

³ Li J, Zitron E, Katus HA, Becker R. Clin Res Cardiol. 2010 Nov 30. [Epub ahead of print] Source

⁴ Mann D, Hill-Cook M, Manire C, Greenhow D, Montie E, Powell J, Wells R, Bauer G, Cunningham-Smith P, Lingenfelser R, DiGiovanni R Jr, Stone A, Brodsky M, Stevens R, Kieffer G, Hoetjes P. PLoS One. 2010 Nov 3;5(11):e13824. Source

⁵ Kafka AP, McLeod BJ, Rades T, McDowell A. J Control Release. 2010 Oct 31. [Epub ahead of print] Source

⁶ Kumar AR, Perez JA, Miick R, Govil YK Endoscopy. 2010;42 Suppl 2:E209-10. Epub 2010 Sep 15. Source - INCLUDES FULL ARTICLE PLUS PHOTO!

⁷ Lukasewycz S, Holman M, Kozlowski P, Porter CR, Odom E, Bernards C, Neil N, Corman JM. Can J Urol. 2010 Oct;17(5):5377-82. Source

New skins for old wine

Curcumin is the metabolite that's responsible for the yellow colour of the spice, tumeric. It can be used for food colouring (it's E number is E100), to quantify boron ¹, and to treat a number of ailments.

The first research on curcumin looked at its antibacterial properties ², and since then researchers have looked at its antioxidant properties ³, its use as an antirheumatic ⁴, a potential cholesterol-lowering role for it ⁵ and many other medicinal applications.

Recently a group in Canada investigated the effect of tumeric on cancer treatment.⁶ Previous research showed that curcumin also has an anti-cancer effect, but these researchers wanted to know if curcumin given in addition to standard chemotherapy could improve the efficacy of the treatment while keeping side-effects to a minimum. The researchers found that the combined treatment worked at lower doses than monotherapy; that non-cancerous cells remained unaffected; and that cancer cells still responded to the treatment even after the drugs were removed.

Many people scoff at the idea of "natural therapies", but it is important to remember that aspirin was originally made from willow bark. Tumeric might be the next aspirin!


¹Roth HJ, Miller B. On the color reaction between boric acid and curcumin. I. Boric acid-curcumin complexes. Arch Pharm (Weinheim)297:617-23 (1964)

²SCHRAUFSTATTER E, BERNT H. Antibacterial action of curcumin and related compounds. Nature. 164(4167):456 (1949)

³ Sharma OP. Antioxidant activity of curcumin and related compounds. Biochem Pharmacol. 25:1811-2 (1976)

⁴Deodhar SD, Sethi R, Srimal RC. Preliminary study on antirheumatic activity of curcumin (diferuloyl methane). Indian J Med Res. 71:632-4 (1980)

⁵Soudamini KK, Unnikrishnan MC, Soni KB, Kuttan R. Inhibition of lipid peroxidation and cholesterol levels in mice by curcumin. Indian J Physiol Pharmacol. 36:239-43 (1992)

⁶
Chatterjee SJ, Pandey S. Chemo-resistant melanoma sensitized by tamoxifen to low dose curcumin treatment through induction of apoptosis and autophagy. Cancer Biol Ther. 2011 Jan 29;11(2). [Epub ahead of print]

Nanobots!

In Star Trek: The Next Generation episode Evolution (1989), Wesley Crusher creates Nanobots called “nanites” which unexpectedly evolve to the point of sentience.

According to the Futurama Wiki "The Nanobots were a model of Robots created by Professor Hubert J. Farnsworth that inhabited the Robo-Planetoid during August of 3010."

Recently, Prof Joseph Wang and his team at UCSD published a paper on fuel free nanomotors¹. These nanomotors or nanoshuttles are designed to pick up, transport, and deliver drugs to their target more efficiently than current nanotherapy strategies.

Each nanoshuttle has a polypyrrole-cadmium nanowire containing a diode, which allows an electric current to flow in only one direction.² In order to get the nanoshuttles to move, an alternating current electric field is applied to the nanowires - this propels the shuttle by converting electrical energy into movement. The nanoshuttles are propelled a distance equivalent to seven times their body length in one second.


¹ Kagan D et al. Small Oct 27 (2010) E-pub
² Burch H. Nanomotors go fuel-free. Chemical Science 09 February 2010. (Source) This article includes a video.