Double-Bagging?

It's been a while since I posted here. This article interested me and I wanted people to know about the study. I’m from South Africa where just under 20% of the population is living with HIV/Aids. This is all news to me!

Apparently using hormonal contraception (i.e. the pill or Depo injection) are at double the risk of getting infected with HIV. On top of that, HIV-infected women who use hormonal contraception are twice more likely to five their HIV to their uninfected partners.

Acquired immune deficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV). So someone can be infected with the virus, (HIV-positive) and then only later develop AIDS.

This study, run by the University of Washington is probably the first study to the risk to male
partners of HIV-infected woman using contraception, according a prof. of global health at the international clinical research centre. It examined almost 3,800 couples in Africa. Each couple had one partner with HIV infection, and the other without. I’m amazed they could find people willing to participate in this sort of study, never to mind couples who knew that their partner was HIV-positive! Ultimately, the statistics showed that using either the pill or the depo injection doubled an uninfected woman’s chances of becoming infected. The same is true for women who are infected – they are twice as likely to transmit their HIV to their partners.

"Women should be counseled about potentially increased risk of HIV acquisition and transmission with hormonal contraception, particularly injectable methods, and about the importance of dual protection with condoms to decrease HIV risk," said Renee Heffron a key author of the study.

The findings of this study were presenting in July in Rom at the meeting of the International AIDS Society. According to UNAIDS estimats, there are 2.2million people living with HIV/AIDS in Europe.

So if you aren’t into abstinence, and if you are sleeping around, double-bagging is the way to go!

Disclaimer: Abstinence is the safest form of contraception.

Secret Life of a Solar Flare

I watched The Knowing last night, and despite negative reviews, I actually quite liked it. *SPOILER ALERT*. It ends with the entire planet Earth being incinerated by a gigantic solar flare. What really interested me was that my weekly NASA Science News email that I got today was about solar flares. So instead of writing a big spiel dissecting the workings of the sun, I thought I would instead include this sweet little video. I would recommend watching just before bed time…

Thanks to NASA Science News

Its definitely a lazy blog entry, but it's back to school time and it's sunny... days like these when little asteroids are being burnt to bits in our outer atmosphere...

Breakfast on Planet Tiffany's?

While travelling recently, I made the mistake of wandering into Tiffany's in the airport. I was quite tempted to have breakfast, but resisted the urge. I have always liked diamonds, but those sparkling, glittering magnificent stones, set so perfectly were something else - I am in love. I just hope my boyfriend doesn't mind. I think I now know their secret...

An international research team with scientists from Australia, Germany, Italy, the UK, and the United States have discovered a pulsar with an interesting neighbour. Pulsars are highly magnetized, rotating neutron starts that emit a pulsing beam of radiation. They are formed when the core of a massive star is compressed during a supernova (a huge explosion), which collapses into a neutron star. Most pulsars have no companions whatsoever, but this one appears to have a very special one.

The orbiting neighbour has a mass close to that of Jupiter and appears to be a remnant of a carbon- and oxygen-rich white dwarf star that measures no more than 55,000 kilometers across. It's make-up and mass mean that it may have a very interesting quality.

''It's highly speculative, but if you shine a light on it, I can't see any reason why it wouldn't sparkle like a diamond," says Travis Metcalfe of the National Center for Atmospheric Research in Boulder, Colorado, talking to New Scientist.

This find is very rare considering the nature of pulsars. Also, a planet that dense is also a rare find.

Some interesting facts...

On Earth, diamonds are formed at pressures of 45-60 kbar.  A kilobar is a metric unit used to measure high pressure. This high pressue corresponds to a depth of 125-200 kilometres below the Earth’s surface where the pressure is around fifty thousand times that of atmospheric pressure at the Earth’s surface.

Some diamonds form at depths of 300-400 kilometres, or even deeper, but these diamonds are particularly rare.

Diamonds are formed at temperatures between 900°C and 1,300°C.

So it makes sense that an old star (very hot) that has collapsed and compressed (very high pressure) that was composed mostly of carbon may indeed ressemble a very, very large diamond.

Guess I know where to have brunch... just hope I don't suffer from space-sickness!

Pass me the Yoghurt, I Feel Sad

In honour of the fact that I am graduating next week, I thought I would scout out some of the new developments that are happening in my college. Seems like I will be eating more yoghurt from now on...


An article publishind in the journal Proceedings of the National Academy of Sciences USA outlined a collaborative project that showed that mice who were fed with a type of bacteria showed less stress, anxiety and depression-related behaviours than those fed with just broth. Importantly, these mice showed lower levels of corticosterone, which is a hormone associated with stress.


What's interesting about this study is that it highlights the important role that probiotic bacteria play in the communication between the gut and the brain. Remember that there are lots of different types of bacteria in the gut, many of which are involved not only in digestion, but also in maintenance of a healthy gut and production of vitamins. According to John F. Cryan, Professor at University College Cork, these findings ''open up the intriguing opportunity of developing unique microbial-based strategies for treatment for stress-related psychiatric disorders such as anxiety and depression.''


Further findings show that feeding mice with this bacteria causes changes in the number of receptors for a neurotransmitter in the brain (called GABA). This is the first time that it has been shown that probiotics can have a direct effect on brain chemistry in normal situations. The communications between the brain and gut is three-way, involving the Vagus nerve as well, and perhaps this axi can be exploited in the future to treat other disorders that involve the brain.


So pass me an Actimel* and perhaps I can fight these 'Back-to-College' blues.

* Just to clarify, Actimel doesn't contain the exact same bacteria that they fed the mice. They used Lactobacillus rhamnosus JB-1, whereas Actimel has some other Lactobacilli.

Sleeping Beauty Had it Wrong...

Apparently that beloved fairytale had it backwards. According to a new study, there is a reason why women wake before men, and tire more easily in the evenings. Here I thought it was just so they could fetch coffee and breakfast in the morning...

A previous article (http://suupedupscience.blogspot.com/2011/07/less-rhythm-less-sleep.html) talked about circadian rhythm (the body clock) and how neural rhythms determine so many body functions. A new study shows that men and women are biologically designed to go to bed at different times. Female circadian rhythm runs faster, and therefore they tire earler and wake up ealier than men. Male rhythm predisposes them to sleep and wake later, and are therefore more likely to be night owls.

The study was led by Jeanne F Duffy, associate professor of medicine at Harvard Medical School, and is the first to find a difference in the body clocks of different sexes. She said 'We found that women are twice as likely to have a circadian rhythm shorter than the normal 24 hrs and mre likely to get sleepy in the evening.'

By contrast, men are more likely to have a rhythm that is longer than 24 hours.

The study involved 200 people and took a month. The subjects were not told the time and were kept in subdued light. The production of melatonin (a hormone that is involved in circadian rhythm) was measured and showed that the average male internal cycle lasts 24 hours and 11 minutes, 6 minutes longer than for woman.

This may not seem like a big difference, but becaus circadian rhythm affects your sensitivity to multiple external factors (like light), it can effectively mean a matter of hours. Duffy explains, 'Morning light exposure aligns us to the 24-hour clock, so if you in on Sunday, it's harder to wake up on Monday.' So if women expose themselves to light in the evenings, they can slow down their cycle, whereas men can do the opposite.

Now I know there is a reason why my mother always insisted on my going to bed at the same time every night. I wonder if there is a reason female cycles are faster. I think back to our hunter-gather days, men would so often be working harder chasing things to kill, so perhaps those who got too tired died out, and so the ones that could stay up later survived, whereas with women, it didn't matter because they were just looking after the cave hearth...

Credits:The Sunday Times 28.08.11,

www.npr.org/2011/05/03/135954176

www.macmillandictionary.com/dictionary/american/circadian

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Gene Therapy 2: Nitty Gritty Cell Stuff

Rise of the Planet of the Apes (or as I like to mockingly call it 'Beginning of the Story of the Rise of the Planet of the Apes') was surprisingly good. No spoilers here, however, in light of the fact that the main storyline involves the use of viral gene therapy to enhance (or heal) ape brains, I figured it would be appropriate to write instalment number two of the gene therapy introduction.

Viruses are used to deliver the correct genetic material to cells in the hopes that this genetic material will be incorporated as part of the cells own genetic code. But how does this actually work?

The above diagram shows a virus (called a vector because it is basically a transport vehicle) attching to a cell. It is an adenovirus vector. Adenovirus is associated with respiratory, intestinal, and eye infections in humans (especially the common cold). As shown in the diagram, the virus is taken into the cell and then travles to the nuclues (the pink thing). It attaches to the surface of the nucleus and injects the DNA into to core of the nucleus. Remember that the nucleus of the cell is where we hold all our own genetic material.

The DNA molecule isn't a double-stranded molecule, but instead is a single strand, and can thus be read by the cells replication molecules. These molecules are called messenger RNA, and they are part of the process by which new proteins are formed. Thus, if the correct DNA is present, the correct proteins will be made, and so any disfunction that occured before may be rectified.

That's the nitty gritty of what is happening in the cells when infected with a virus vector carrying the corret DNA sequence. Next up we'll look at what diseases and disorders have been cured or treated to date, and what side effects have occured.

Will gene therapy one day become the ultimate application of genetic technology? Gene Therapy, the newest booklet in the Special Topics in Biology Series, addresses this question by exploring gene therapy as a complex technology for delivering therapeutic genes as a way to treat and cure human genetic diseases.
Author Mary Colavito provides an overview of the basic science involved in gene therapy methods and chronicles the history of gene therapy by discussing successful and ongoing gene therapy treatments as well as adverse outcomes in some cases of gene therapy. Also discussed are challenges that must be overcome for gene therapy to become a more reliable and readily accessible approach for treating a multitude of genetic diseases that affect humans.

The World is No Longer Flat: A Cure for Viruses

This shifting world never ceases to amaze me. When I went into the field of Science, a path that did not come naturally or totally suit my strengths, my parents would jokingly suggest that maybe I would find the cure for the common cold. In jest; veritas, but I already thought I knew that there was no way that would ever happen. Viruses can't be targeted; they change too much; they aren't really living organisms. They hide extremely well in our bodies so that we are not always able to find them and make antibodies against them. You can treat the symptoms of a virus. But you can't kill the virus.

It seems, however, that we have, yet again, been proven wrong. Oh Copernicus and Galileo!

Scientists working at MIT's Lincoln Laboratory have supposedly designed a broad-spectrum drug that may make viral infections a thing of the past. Most infectious diseases are caused by either bacteria or viruses. Most bacterial diseases can be treated using antibiotics, however, such a cure for viral infection has remained elusive.

"If you detect a pathogenic bacterium in the environment, there is probably an antibiotic that could be used to treat someone exposed to that, but I realized there are very few treatments out there for viruses," said Todd Rider, one of the scientists credited with discovering the new drug.

Double-stranded RNA Activated Caspase Oligomerizers (DRACO, for short) seems, at least in theory, to be able to destroy any virus. To date, viruses that have been treated include rhinovirus (our not-so-friendly cold-causing virus), H1N1, a stomach virus, a polio virus and dengue fever (transmitted by mosquitoes).

"In theory, it should work against all viruses," said Rider.

The nitty gritty of how this drug works is complex. It utilizes a protein that targets a type of double-stranded RNA that is produced only in cells that are infected by a virus. These protein then joins with another protein, causing the cell to die (apoptosis). The key is that only cells infected with a virus will have that double-stranded RNA, so the drug will only target infected cells.

Apparently, DRACO can also ward off drug resistance, which is often a problem when using antibiotics to treat bacterial infections, leading to superbacteria.

So far the only mice have been tested using DRACO. They were infected with the H1N1 influenza virus were cured by the drug without any toxic side effects. Hopefully, larger animals will be tested soon, with human clincial trials the end goal. It could take up to a decade before DRACO is availale on pharmacy shelves.

A Brief Introduction to Gene Therapy

I haven’t written an article on Gene Therapy, and seeing as it is something a vaguely specialise in, I think it’s about time I do. So here it is.

Gene Therapy is an umbrella term for many types of treatments. Ultimately it involves changing or fixing or replacing genes that are defective or mutated in someone’s cell such that the cells can function again. Remember that genes represent the code by which just about everything that happens in the body follows. It’s like the instruction manual for the body. So if some of that code is missing, or incorrect, the body won’t work properly.

Examples of such diseases would be cystic fibrosis, Huntington’s disease, Sickle-cell anaemia and a huge range of immunity disorders. Even cancer is caused by genetic mutations. So if there was a way to fix the code, repair it in some way, this would have huge benefits to thousands of people.

More here: http://offthemark.com/

One way to fix a broken code involves using viruses. This may sound alarming, but it is actually quite effectively used. The basic principal revolves around using a harmless virus i.e. one that will only infect certain cells and won’t replicate, to carry the corrected gene code to cells. Viruses do this anyway – when they infect a person, they are often actually infecting the cells, their own gene codes being incorporated into the host cell. Usually this is detrimental, but by controlling what gene sequences are included in the virus, you can make tailor what happens when a virus infects a cell.

There are a few ways to ‘infect’ the cells with the virus. Say you have someone who has cystic fibrosis; their lung cells have defective genes that code correct mucous production. So if these genes were fixed, the cells would work correctly. Ideally, the virus could be injected into someone’s lungs, where they would infect the lung cells. These lung cells would ultimately then start performing the way they should. This is termed ‘In Vivo gene transduction’ i.e. you are placing the virus directly into the human, into the cells. Another method is to take the defective cells OUT of the body, and then infect them, only to put the hopefully fixed cells back into the body. This could work for any disorders that involve bone marrow (e.g immunity diseases or blood disorders). This is ‘Ex Vivo gene transduction’.

So there is the introduction to gene therapy. I could write a book on it. But there will be more posts soon... huge inroads are being made all the time in this field.

Teary Solution

I woke up this morning to the shocking news about the riots in London. These things really amaze me, and so I started researching about mob mentality and mass hysteria. The literature is endless, and I can’t fully relate. So instead, i started looking at riot control. Tear gas?

Tear gas works by annoying the mucous membranes in the eyes, nose, mouth and lungs, causing a multitude of effects. It causes excess tears, coughing, snot production in the nose and often panic. The blood pressure rises, and the breathing and heart rate slow. It is a skin irritant and causes a burning sensation on any skin exposed to it. Nausea and vomiting may also be caused.One of the more commonly used riot control agents is called CS. It is not actually a gas, but instead a very fine, white acid powder. Studies suggest that if this compound is sprayed into eyes, serious damage can occur. Some studies recommend blowing dry air into the eyes to remove it, but this actually doesn’t work. Correct treatment would involve prolonged and copious irrigation with water or a normal saline solution to deactivate CS, such that the solid particles can be removed from the eye.

According to the BBC, the correct response if exposed to CS is as follows:

‘Immediately hold your breath, and do not panic. Almost completely close your eyes, and expect to be blinking a lot. If you are a long way from fresh air, cover your face with a clean cloth - your outer sleeve is probably covered with the stuff so pull your sleeve up or inside out if necessary.

Remember, CS is not a gas. It's a powder, so it's relatively easy to stop the stuff getting up your nose. Don't breathe through your mouth if you can avoid it - it will give you a bigger dose quicker and will cause coughing and possibly vomiting.

Your first priority should be to get to fresh air. If you are indoors, get out as quickly as possible. If you are outdoors, try to see where the CS is coming from and get out of the way. As soon as you get into fresh air, keep moving. Your clothes will be coated with the stuff, but the majority will blow away in the wind, so hold your arms up and turn around. When you get the chance, wash the clothes thoroughly separately from any others. Above all, remember that the effects will wear off very quickly when you reach fresh air, so do not panic.’

Well at least now I know. The advice doesn't work if you have other reasons for tearing up. I tried.

Click here for more: http://www.explosm.net/

Credits:

Emerg Med J. 2010 Nov;27(11):881-2.

http://www.bbc.co.uk/dna/h2g2/A655517

Food: A Drug of Choice?

I dropped two dress sizes recently. Accolades are not entirely in order as I didn’t really try – never have believed in to diets – I’m too lazy! But as I got thinner, I began noticing just how fat we are as a population. Obesity is on the rise, with 16 to 20% of Irish women and men respectively being overweight. There are many reasons for this, and here may be yet another one...

Food may act physiologically like a drug for some people. According to a researcher (Sheeley McGuire, PhD): "We've known for years that foods- even eating, itself- can trigger release of various brain chemicals, some of which are also involved in what happens with drug addiction and withdrawal.’’ She goes on to suggest that repeated use of food (habituation) is sometimes accompanied by a lack of response, or in other words a loss of interest in food. This can actually lead to a lower calorie intake. Many diets utilize this idea, and meals become monotonous. For example, liquid diets or low carbohydrate diets. The other side of that is the idea that when presented with a variety of foods, calorie intake will increase.

The ‘’food addiction hypothesis’’ proposes that some people may overeat because they are insensitive to the normal ‘loss of interest’ response. They have lost their habituations reflex. So they can easily keep eating the same food (and possibly lots of it) without getting bored. This brings to mind people ordering half a dozen burgers and chips; tasteless and monotonous.

The study is pretty boring to read, but concludes that reducing variety of food choices may be a method of dieting. As if Atkinson doesn't already know that. The idea of habituation interests me, and I wonder if that stretches to other aspects of our lives? 

Thanks to: http://bestinshowcomic.com/wordpress/

You Wear Your Heart on Your Sleeve, Mr. Green.

(Or More Correctly, On Your Back!)

Waiting in the line at the bank is often a heart stopping moment – ‘I have HOW much left?!’ But as I was watching Sky News I found out that someone has finally been transplanted with a portable artificial heart made my own heart speed up with excitement. THIS is big. THIS is news.

In a hospital in Cambridge on the ninth of June, Mr Green became the first UK patient to receive a portable artificial heart implant. The operation took 6 hours and the implant seems to be working successfully as Mr Green’s symptoms decline.

This plastic device is a temporary measure while the patient awaits a real donor. The transplant itself is a plastic device. It replaces the ventricles of the heart, which are the two large, lower chambers of the heart. These chambers pump blood to the lungs and the whole body. The operation involved moving the failing ventricles from the patient, and attaching the artificial ventricles to the heart by plastic tubes.

But how is it powered, you ask? It does not contain any motors or electrical parts but is run by a power supply that is carried outside the body. Normally, a patient with a failing heart would have to be kept in the hospital with a large, fixed machine supplying power to the artificial parts. This new device, although heavy at 14lbs, allows Mr Green freedom as he waits.

There have been other artificial heart devices, but these were normally to help a single damaged ventricle. An example would be the Jervik-7 Artificial Heart that was used in the 1980s. But this new device is the first case where the patient can return home. It cannot be used indefinitely, but is instead termed as a ‘bridge-to-transplant’ device.

This may sound like something out of The Terminator or I Robot, and perhaps it is. I imagine this is this is the beginning of a long series of discoveries and innovations that will make us more and more reliant on artificial parts to replace our failing ones. This portable heart just gave new meaning to wearing your heart on your sleeve…

Credits: Various News Articles,

             Tex Heart Inst J. 2010; 37(2): 149–158.

No More Back Seat Driving - Front Lobe Driving?

I don't drive, but I can be an annoying passenger some of the time - my mind travels with the car, and I get frustrated when I can't keep up, or if I am ahead of whoever is driving. But perhaps my mind will be enough; new technology may allow for drivers to use their minds to brake, and maybe eventually drive entirely.

There is a moment that lasts about 700 milliseconds just before a driver decides to brake, where brainwaves are being emitted. It is these brainwaves that can now be detected and interperated by a system designed by Stefen Haufe et al. In the study, scientists at Berlin Institute of Technology in Germany measured changes in brain wave changes while participants drove in a car simulator.

“Our approach was to obtain the intention of the driver faster than he could actually act,” Haufe says. This would certainly make a huge difference in the numbers of collisions; isn't it always those few seconds that lead to regret?

But there are a few kinks and many skeptics. Even when the system is working at its best, it slams on the brakes almost two times per hour. Also, drivers whould have to wear an uncomfortable and unattractive EEG cap. With that many false alarms, it may be more dangerous than safe.

I heard somewhere that there was a time when they thought that there was a limit in the amount of memory you can have in a computer. So maybe this is just one of those things. Time will create the technology needed to work out the kinks. I wonder how much we could control with our minds...

Credits: Stefan Haufe et al 2011 J. Neural Eng. 8 056001 doi: 10.1088/1741-2560/8/5/056001

Less Rhythm = Less Sleep

I recently spent an extended holiday with my grandparents in South Africa. It was an amazing trip all round. But I found myself sleeping very little, waking up at insane hours, and surviving on vast amounts of coffee, which I have since managed to wean myself off of. It got me thinking though; a lot of the old people I know find it difficult to sleep, why is that?

The body clock which maintains circadian rhythm (sleep-wake patterns among many other patterns) is called the suprachiasmatic nucleus (or SCN) which is located in the hypothalamus in the brain. Neural signals from many parts of the body are received by the SCN which, coupled with other minor body clocks, generate a pattern of rhythmic activity, all in response to various factors including daylight, hormone levels and temperature.

A study lead by UCLA Chancellor Gene Block involved examination of the signals emitted by the SCN in mice. Results showed that the signals from this clock start to decline in middle age, and this may be true for humans as well. Normally during the day, SCN brain cells are active, while at night they are silent. It was suggested and proven the case that it is a change in this pulsing that affects sleep patterns in older mice (or people). Indeed, disruptions in the SCN lead to disrupted sleep, dysfuntion in memory, the cardiovascular system and even the body’s immune response and metabolism. The study suggests that one of the causes of these changes is a reduction in the amplitude of the signals being emitted from the SCN.

So now I get why old people struggle to sleep and why they are often tired. Even more than that, the decline of rhythm affects so many other body functions. I don’t think it accounts for bad dancing though…

Retrieved August 1, 2011, from http://www.sciencedaily.com­ /releases/2011/07/110719093808.htm

Eat more wheat and less meat: Is a Vegetarian diet better?

I have met many a vegetarian who holds the view that they are better than I because of their dietary choices. At one point, even I followed suit, hanging up the meat hooks in exchange for gardening gloves. I loved it – I felt healthier and lighter and actually enjoyed the ‘green’, meat-free diet. A few years later, I got very hungry at a barbeque, and succumbed to a delicious chicken drumstick. I haven’t looked back… until now…

It was recently suggested that vegetarians are approximately 30% less likely to get common bowel disorder than meat-eaters. Bowel disorders (or diverticular disease) are common in western civilisation with symptoms that include abdominal cramps, bloating, excessive wind, constipation and diarrhoea.

Nearly 50 thousand people took part in the study set up by a team in Oxford, of which approximately 15 thousand reported to consume a vegetarian diet. Over about 11 years, there were 812 cases of bowel disease. After adjusting the statistics to include other possible factors such as smoking, alcohol consumption and weight, the study revealed that vegetarians had a 31% lower risk of getting bowel disease compared with meat eaters.Furthermore, people who had a high intake of fiber (around 25g per day) also had a lower risk of being admitted to hospital or dying from diverticular disease compared with those who ate less than 14g per day.

Fibre or roughage is the indigestible portion of plant foods. Some types of fibre are broken down by bacteria in the colon and are used as energy sources, while other types absorb water and expand, moving through the digestive tract, easing defecation. So it makes sense that a diet that relies more on fibre rather than meat would lead to a lower risk of bowel disorders.

I don’t think I will betray my taste buds again and deny myself carnivorous pleasures, but I could easily devour more greens and beans, especially if there is a chance it will save on hospital bills…

Credits: BMJ 2011; 343:d4131