HIV - The virus, its effect, treatment and the future.

The Human Immunodeficiancy Virus (HIV) has been documented as the worst pandemic in human history. Yet despite approximately 70 million contracted cases, accounting for more than 35 million deaths, a definitive cure has evaded researchers to this date for a number of reasons. For one, rapid antigenic drift means that the intricate acquired immune system of humans cannot keep up with the constantly changing antigenic make-up of the HIV's surface (surface coat of the virus frequently changes). The HIV retrovirus also has a target immunocyte, the CD4+ helper t cell. By attacking the cells that signal, synthesise and mediate the function of the CD8+ cytotoxic t cells amongst other immune effectors, they further reduce the chances of the immune system defending against the infection. HIV is a retrovirus that causes acquired immunodeficiency syndrome (AIDS), a condition in which failure of the immune system enables opportunistic infections and cancers to thrive. HIV is a blood-borne virus that can be transmitted via the transfer of blood, semen, vaginal fluid or breast milk.

An HIV viral molecule.

Acquired Immune Response

            One of the main systems which sets out higher vertebrates from their invertebrate counterparts, is a sophisticated, well-developed immune system. The acquired, or adaptive, immune system, enables humans to recognise non-self pathogens as well as creating an immunological “memory” whereby repeated infections by the same strain of a disease will be recognised and defended against more efficiently. The cells responsible for this task are the T and B lymphocytes. The CD4+ Helper T cell are vital to proper immune function. These cells aid B cells in producing antibodies, recruits neutrophils, eosinophils and basophils to infection site, inflammation and through cytokine and chemokine signalling, orchestrate the many components of immune response. Another prominent immune effector in mammals are the CD8+ Cytotoxic T cells. These immunocytes recognises and binds to specific viral antigens on infected cell surfaces and releases chemicals to destroy the cell before the virus can enter the nucleus and begin replication. The HIV virus is so devastating to the human body as it selectively invades the CD4+ Helper t cells; the HIV envelope glycoprotein gp120 binds to to the surface of the CD4+ helper t cell followed by internalisation. This renders them incapacitated and prevents them from mediating the intricate immune response. Furthermore, the HIV virus targets macrophages which are major effectors in phagocytosing, engulfing and digesting pathogens and cellular debris. HIV infects these cell types in different ways however as CD4+ cells are generally eliminated by host pathogenic effects whereas macrophages physically survive, acting as an infection containing reservoir.

Why HIV is able to successfully hide from the immune system

Antigenic variation is a prominent factor in a diseases resistance to a host immune system. HIV is a retrovirus meaning that the enveloped virus replicates within the host cell via reverse transcription. Once the single stranded RNA enters the host cell cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA. Now, normal transcription is subject to massive amounts of proof reading to prevent any sort of mistakes and therefore mutations. HIV reverse transcription harbours no mechanisms of proof reading and therefore every viral replication produces mutated versions. As it replicates so quickly, millions of varying strands of the virus are produced within a single host so that even when the acquired immune system recognises a particular strain, many more are already going undetected. This mechanism of producing many mutated strains is an effective method of immune avoidance but it is not under the control of the virus itself. Often, less effective or benign strains of the virus are produced but due to the sheer magnitude of viral replication, enough harmful strains are produced to be effective.

An HIV virus binding to the CCR5 receptor of a CD4+ helper T cell and entering the cytoplasm.

Treatment of HIV

Historically, the stigma of HIV has been that it is a death sentence, however advances in medicine have dramatically increased not only the standard of living of patients, but also their longevity. Highly Active Antiretroviral Therapy (HAART) maintains immune system function as well as preventing opportunistic infections normally associated with a depleted immune system. Treatments have also meant that HIV progression into AIDS is becoming increasingly rare. A paper published in 2012 has suggested that as many as 700,000 lives were saved in 2010 as a direct result of antiretroviral therapy. Prior to treatment, the average life expectancy of someone infected with HIV was 9-12 years post-infection. Now, patients can live to their normal life expectancy despite carrying the disease, however as a cure is still not available, they can still transmit the infection.

Future of Cure and Vaccine Research

As it stands, there is no way of curing or preventing HIV. Obviously, there is ongoing research into more efficient and effective retroviral treatment but the main priority should be into a cure the virus, or even better a vaccine to prevent it in the first place. Efforts have been placed on targeting the gp120 on the surface of the virus that binds to the CCR5 receptor on the CD4+helper T cell. There are documented cases of individuals who possess a 32 base pair deletion on their CCR5 receptor that are technically immune to HIV. Studies on these particular mutations could pave the way to a definitive vaccine.

Thankfully, we live in an age where treatments are available but many of the sufferers of HIV do not have access to such therapy. The disease is most prevalent in Africa where a combination of lack of education about the disease and lack of funds to afford treatment make it particularly devastating. Awareness saves lives and there should be no stigma to being tested. Preventing the spread of the disease can be as important as developing a cure. I find this disease as fascinating as it is devastating so if you would like to know more about it, I would be happy to answer any questions.

Prevalence of HIV, the predominance of cases are in Africa due to lack of education and access to treatment 

Simple science shorts #1

Again I would like to explore a different route. As I haven’t posted in a while I thought I would lump together some ideas I have had over the past few weeks that I feel may not be worth an entire blog on their own. If you would like some more short questions answered send me a message and I could include them if I do something along these lines again! Enjoy!

Why does your stomach rumble when you are hungry?

                A very common occurrence during the interdigestive phase. It has been several hours since your last meal and suddenly everyone around you becomes very aware that you are hungry. The rumble of your stomach associated hunger is a series of convulsions known as the migrating motility complex (MMC). The MMC triggers peristaltic waves (muscular waves, the same as in your throat for swallowing) in an attempt to transport indigestible materials such as bone past the ileocecal sphincter and into the colon. So in essence, your stomach starts attempting to suck in other parts of your body to eat.

What makes your eye twitch?

                Unwelcomed spasms of the eyelid come and go without much thought despite them being mildly annoying. Known as “myokymia” to doctors, an eye twitch is simply rippling muscle contrations caused by a variety of simple triggers such as: tiredness, stress, caffeine, allergies, dry eyes, alcohol consumption or caused by an irritant. Generally (almost always), eye twitching is a benign condition (meaning harmless) however in some cases it can be an indication of neurological conditions. Blepharospasm is a CNS disorder sometimes associated with an eye twitch however the cause is not yet known.

Heard of a Demodex?

                Based on their abundance you definitely should have but if you are squeamish I recommend skipping this section and move on…..

Demodex are arachnids called eyebrow mites and they are considered one of the most commonly occurring human parasites. Up to 90% of people have them and they are very contagious but at only 0.3mm long, you won’t be seeing any without a microscope. The 2 species that might be found within your hair follicles or sebaceous glands are Demodex folliculorum and D. brevis but do not worry, they will not harm you in any way. They simply feed off of skin cells and oils which can actually be beneficial by preventing waste build up on the skin surface.

Demodex folliculorum

What causes “butterflies” when you’re nervous?

                Some of you may now be experiencing this due to your new found knowledge about Demodex. Interestingly, your digestive system is actually closely linked to your thoughts and emotions. When you are faced with a nerve-wracking situation the body undergoes its “fight-or-flight” response which includes increase of heart rate, blood pressure and breathing rate. Stimulation of adrenal glands also releases adrenaline and cortisol whilst muscle contraction makes the body more alert. The rush of adrenaline temporarily halts digestion enabling energy and oxygenated blood to be utilised in the necessary working muscles. Sensitive muscles surrounding the stomach also contract. The combination of muscle contraction and ceased digestion gives you that fluttery feeling when you are racked with nerves or fear.

Which came first the chicken or the egg?

                The egg….Dinosaurs laid eggs…

How accurate is counting a trees rings to determine its age?

               

                Dendrochronology is the analysis of growth rings and throughout school we have always been told you can determine how old a tree is by simply counting the rings when you cut its trunk in half. Well this is actually completely true, but the age of the tree is not all you can find out from a cross section of the trunk. Growth rings are the result of recent growth in the vascular cambium which is a layer near the tree bark known as a lateral meristem. There is a visible ring because of variation in growth speed through certain seasons of the year. The inner portion of the growth ring is formed during the early stages of the growing season. Then, under the optimum conditions, rapid growth produces less dense and differently coloured wood followed by the end of season, dense wood giving the distinctive ring formation. The rings can vary dependant on the growing conditions. A wide ring will occur when there is adequate moisture and a long growing season whereas a drought year causes a narrow ring to form. This can however cause confusion as mid-summer droughts can result in “missing rings” or several to form in any given year. To a skilled dendrochronologist however, this is merely an indication of seasonal shifts and the trees age can still be identified accurately.

Note the lighter, less dense rings indicating the rapid growing season. You can also see the variation in size indicating optimal and poor growing conditions.

The octopus: greatest animal ever? Yes...yes it is.

If your favourite animal isn’t the octopus I can tell you right now that you are wrong. These majestic invertebrates are not only top predators but are also intelligent, masters of camouflage and delicious. They are cephalopod molluscs with a beak, 2 developed eyes, 8 distinctive arms, venom, 3 hearts, and several characteristics that belong in sci-fi films.

Firstly, I’d like to settle the plurality debate: OCTOPUSES is the plural of octopus, not octopi. This is because the name derived from ancient Greek (ὀκτώπους meaning 8 legs, obviously). Had octopuses been of latin decent the “i” ending would be correct… but its not.

Camouflage

            You think chameleons are the masters of colour change? Wrong! Cephalopods (octopuses, cuttlefish and squids) have the most advanced mechanisms of rapid adaptive camouflage that cannot be matched by any land animal. Many animals that possess the ability of colour change must move to the correct visual background with appropriate lighting conditions to fully implement camouflage. Octopuses however have such precise vision and sophisticated skin, they can use direct neural control to rapidly change and fine-tune the optical diversity of their colour change. As can be seen in the below image, the Octopus vulgaris can change from completely invisible to its normal state in a fraction over 2 seconds.

A time lapse representation of the Octopus vulgaris using camouflage. The difference between the first and last image is 2.02 seconds.

Not only are octopuses able to adapt their colour they can also manipulate their shape. The ‘mimic octopus’ Macrotritopus defilippi has mastered the art of hiding in plain sight. Often found in open sandy habitats, it mimics the swimming behaviour of a flounder to deter predators. Typically, predators of the octopus are seeking a soft, fleshy meal and will therefore ignore what seems to be a boney flatfish. Octopuses have also been noted to use batesian mimicry whereby they imitate the warning signals of a harmful species despite being harmless themselves. Some species have been observed to imitate the colouration of the deadly lionfish. Octopuses, and other cephalopods, are able to alter their colour because of chromatophore organs. Chromatophore organs are composed of a single chromatophore cell and an elastic sacculus containing pigment. When excited, the sacculus can expand and retract accredited to specific neural control, allowing particular colours/patterns to be revealed.

https://www.youtube.com/watch?v=orrdcwTuXmQ

DID YOU SEE THAT

There are even better videos on youtube but this was the best I could find on short notice without annoying commentary. Have a look!

Intelligence

            The true extent of the octopuses’ intelligence is under serious debate but regardless, their intellect can be considered a great evolutionary success. Two thirds of an octopuses neurons reside in its arms rather than its head. This means that each individual arm can “consciously” solve problems, like opening shellfish, whilst the others can be busy doing other things like foraging for more shellfish. It seems effortless that an octopus can coordinate and control its 8 arms yet we as human beings struggle to control our own fingers….oh you can? Try this: place your hand palm down on the table/floor/surface. Bend your middle finger inward as shown in the picture. Now, keeping your hand down, raise and lower your pointing finger….raise and lower your pinky….raise and lower your thumb…raise and lower your ring finger. Not gonna happen. Also try miming anticlockwise circles with your right foot whilst drawing the number 6 with your right hand.

Place your hand like so and see how much control you really have over your own digits.

Back to octopuses however…they are unique among invertebrates due to their extremely large nervous system. In laboratory experiments they can readily learn to associate visual or tactile stimuli with a positive or negative reward, they can learn by observation and in maze experiments have shown prominent evidence of both a short-term and long-term memory.

Like chimpanzees they have also been witnessed to use tools. Some species of octopus carry coconut shell halves under their bodies to later assemble into shelters; others use stones to barricade the front of their dens. This shows a level of cognitive ability and sophisticated behaviour that used to be exclusive to vertebrates. Some octopuses have a special set of skills that even human beings cannot come close to matching. For example, I can’t for the life of me win a football bet yet a certain octopus named Paul managed to predict 11 out of 13 matches during the 2010 world cup.

Paul the octopus

Other amazing things about octopuses that I can’t fit in without turning this into a novel

• The suckers on the octopus appendages are both incredibly strong and very delicate. Not only can they individually respond to subtle chemical signals, a single large sucker can hold up to 15kg.
• Their dexterity is phenominal. In some tests, octopuses have been able to unlock and open the top of a childproof pill bottle.
• The blue ringed octopus has enough venom to paralyse an adult (most species however, do not have venom)
• They can fit through the smallest of holes. As its body is fully flexible, an octopus can fit through any sized hole, no matter how small, as long as its beak can fit through. (http://video.nationalgeographic.com/video/octopus_cyanea_locomotion)
• They have 3 hearts – 2 work exclusively to transport blood beyond the animals gills whilst the 3^rd acts similar to a human heart, circulating haemocyanin (equivalent of blood) to the organs. BONUS FACT – the heart actually stops beating as it swims which makes octopuses prone to crawling as swimming can be exhausting.
• Octopuses have highly developed eyes. Some species actually have colour vision and most have statocysts which allow the animal to sense its orientation relative to horizontal.
• The octopus defense mechanism of shooting ink at a potential threat does not only hide the animal, it also harms the predator. The ink contains tyrosinase which causes blinding irritation and disrupts the sense of smell and taste. Despite their advanced intelligence, octopuses that fail to escape their own ink cloud, can accidentally kill themselves.
• THEY CAN HUNT SHARKS. Seriously. Watch. (https://www.youtube.com/watch?v=rCDBt-4NSCk)
• Olfactory sensors have been identified in the suction cups on the octopuses arms. Meaning they can basically smell with their arms.
• A detached limb from a predation attack can regenerate. I have read that they occasionally eat their own arms in certain circumstances but the sources are far from reputable.

Asbestos: awareness that could save your life.

As far as I am aware, everyone knows that asbestos is pretty bad. At some stage, most people will have at least heard of a building being quarantined due to disturbed asbestos but how detrimental can it really be to our health? What effects does it have on our body and what preventative measures can be taken? To begin I will outline what asbestos is and why it is so common.

            The use of asbestos has been dated back over 4000 years and contrary to popular belief, it is not man made, it is actually mined. Initially it was used to strengthen cooking utensils and woven into clothes but it was not very commonly used. Later, in the industrial era, manufacturers and builders began utilising asbestos for its favourable properties. Asbestos is resistant to heat, fire, chemical and electrical damage as well as being inexpensive and have high tensile strength. Based on these attributes and lack of knowledge regarding potential health defects, asbestos was widely used in insulation, ceiling tiles, in walls, fireplaces, surrounding boilers, floor tiles amongst other places. Although throughout history it was noted that people working in asbestos mines or in asbestos manufacturing experienced negative health effects, the first documented death relating to asbestos was in 1906. Despite subsequent cases of deaths relating to exposure to asbestos, it was still ordinarily used in construction until legislation passed in 1999 outlawed its use. As a result, many homes, schools, factories and offices built before 2000 can contain asbestos. But do not panic. Asbestos is only dangerous if it is disturbed or damaged.

As you can see,  asbestos can be extremely common around the home. Do remember however that it is harmless unless disturbed so always take care before undertaking any destructive DIY work.

Health defects caused by asbestos

            As aforementioned, exposure to asbestos fibres can be dangerous and often fatal. Asbestos is a generic name for a group of minerals that have severe adverse effects on the respiratory system. Inhalation can cause fibrosis of the lung (known as “asbestosis”) as well as 2 types of malignant tumours making it a prominent carcinogen. Mesothelioma is a tumour of the serosal cells which line the pleural and peritoneal cavities (the external lining of the lung and the lining of the abdomen respectively). This form of cancer is rare but is predominantly seen in individuals whose occupation entails the risk of asbestos inhalation.

The second type of cancer caused by asbestos is bronchogenic carcinoma. This begins as a small lesion within the epithelial cells of the bronchial mucosa which grows and develops into the bronchial lumen. Eventually it can spread to the regional lymph nodes and other distant organs.

            But how does asbestos fibres actually cause cancer? Well asbestos kills cells in a gruesome process known as ‘programmed cell necrosis’. Instead of the cell merely dying and being harmlessly disposed of via macrophages, the cells release group box 1 protein (HMGB1). This protein induces a particular type of inflammatory reaction that causes the release of mutagens and tumour growth factors

Identifying asbestos:

            Below are some images of asbestos, as you can see, it can be rather difficult to identify and comes in a variety of colours (white, brown and blue).

 

The 3 main types of asbestos

White asbestos

An example of a ceiling that contains asbestos

If you discover asbestos or even think you have, don’t panic. If it is in good condition it will not pose a concern to your health. Just ensure that it is not damaged or deteriorated. Importantly, if you are aware of asbestos and your house is being renovated, always inform the tradesperson! Never assume they have identified it.

If you wish to remove asbestos for whatever reason DO NOT THROW IT IN THE BIN OR USE A NORMAL HOOVER. Contact your local council who will dispose of it safely. 

Your blood and what you can do with it.

It flows through all of our veins, and although it looks identical from person to person, there is a lot more than meets the eye with blood. Firstly, a common misconception is that blood is just a red liquid that flows through our veins and arteries when in actual fact it is much more complex. Blood is a series of cells suspended in plasma:

• Erythrocytes – the biconcaved red blood cells are the most abundant and are the principal means of delivering oxygen to body tissues via the circulatory system.
• Leukocytes – these white blood cells are the immune effectors. There are several types of white blood cells with a range of specific and general immune functions.
• Platelets – important for coagulation. At a site of interruption, platelets prevent bleeding by clotting (thus the formation of scabs).

The constituents of blood.

Most of us have heard the term “blood type” especially if you are generous enough to donate your blood, but many people do not understand the key differences between the blood types and why certain people cannot receive specific blood types based on the composition of their erythrocytes (red blood cells). Also did you know that there are currently 33 recognised human blood group systems? However it is commonly divided into 4 main groups: A, B, AB and O (known as the ABO system), and these 4 groups can either be RhD positive or RhD negative.

The ABO system is determined by the presence of specific glycoproteins on the surface of the red blood cells known as antigens. Antigens are unique, microscopic markers that need to be matched correctly otherwise complications can arise during blood transfusions. Differentiation is relatively simple, if the red blood cells are covered in A antigens then that person is blood type A. If they are covered in B antigens then they are type B. Both A and B antigens type AB and if they have neither then they will be categorised as O. The significance of matching blood groups in transfusion is a result of antibodies associated with blood types. For instance, blood type A has antibodies against B antigens (and vice versa) meaning they are recognised as foreign to the body disposed of immunologically. Type O blood has antibodies against A and B antigens whilst AB blood has no antibodies at all. This seems fairly complicated with lots of letters being thrown around so I will do my best to simplify it.

• Blood Type O – has no antigens so can be universally donated as no antibodies can recognise it as foreign. Unfortunately as it has antibodies against A and B, people with type O blood can receive blood from the O group only. (Universal donor)
• Blood Type AB – Has no antibodies so can receive blood from any other blood group. (Universal recipient)
• Blood Type A – Can receive blood from type A and O but will reject type B and AB due to antibodies against B antigens.
• Blood Type B – Can receive blood from type B and O but not A or AB due to antibodies against A.

Simple representation of the surface antigenic make up of red blood cells.

To make matters slightly more complicated blood types also fall under the Rh system. This is based on 5 Rhesus antigens: C, c, D, E and e. Most important is the D antigen whereby the presence of which makes a blood type positive and absence negative. The presence of the D antigen can also cause a transfusion reaction so the true universal donor blood type is O- as it has no A, B or Rh antigens for a recipient to reject.

So there you have it,  a brief overview of what is going on in your veins. It is all well and good to understand what your blood type is but it is much more important to do something with it. The volume of blood in an adult human is approximately 5 litres. When donating blood a mere 470mls are taken and that is regenerated pretty rapidly (fluid in less than 24 hours, red blood cells in 3 weeks and iron in around 8 weeks). For those of you that haven’t donated blood before I urge you to do so. The nurses are always accommodating to those who are nervous with needles and it is far from painful. About half as sore as a wasp sting when the needle enters then no pain during the process. Some people experience slight dizziness and or light-headedness but the free tea, coffee and biscuits quickly squares you up. Donating blood is such a simple act that benefits so many people in cases of transfusions, serious accidents, cancers, childbirth, bone marrow failure and surgeries to name a few.

In closing I urge you to do something incredible. Give blood. Look for your local donation times and dates here:

https://www.scotblood.co.uk/

Smoking tobacco and a look at e-cigarettes

I am not just a non-smoker. I am an anti-smoker. Not only because of the catastrophic health defects but I just hate the smell. Cigarettes are a known cause of lung, mouth, lip, throat, larynx, oesophagus, bladder, kidney, liver, stomach and pancreatic cancer to name a few. Damaged caused to the heart also places a smoker at risk to heart disease and other vascular problems. It begs the question, how can simply smoking cause so many problems?

Well, tobacco smoke is rich with compounds emitted in gases and condensed tar particles. Most of these compounds are genotoxic (genetically harmful) and carcinogenic (cancer causing). The constituents of the compounds are alkenes, nitrosamines, aromatic and heterocyclic hydrocarbons and amines (generally synthetic and very harmful). Issues are slightly less severe as second hand smoke but are still heavily detrimental.

The effects of second hand smoke on infants as well as adults.

Adverse effects of smoking tobacco (there are more!)

The latest smoking trend however is e-cigarettes. I for one have welcomed it based entirely on olfactory reasons but are they really a clean and “healthy” alternative to the classic smoke and tar combo? Until recently, electronic cigarettes have had very little laboratory testing and as a result they have been marketed as tobacco-free, nicotine delivery devices that are a safer, more sociable option opposed to cigarettes. On a social front, studies have shown promise that e-cigarettes may be a useful tool in smoking abstinence. Respondents to a survey published in the American Journal of Preventive Medicine found that using e-cigarettes for a prolonged period of time increased rate of smoking cessation. The relevance of this study is questionable as tobacco consumption is self-monitored and sample sizes limited. On the contrary to smoking cessation, e-cigarettes have been found to have a “glamour factor”. In a study published this year, it has been found that passive exposure to e-cigarettes significantly increases observers’ desire or urge to smoke a regular cigarette or to try an e-cigarette for the first time. The funky flavours and sleek designs make them cooler than the average white stick and tar taste with the added bonus of “smoking” indoors.

Attractive designs such as this could be encouraging more people to start smoking than help them to stop.

Now for the science. E-cigarettes still contain nicotine, a parasymphathomimetic alkaloid. This is not only worth 54 points on scrabble (without any bonus squares), but it is a naturally occurring insecticide in plants, ie. Toxic. In humans, it acts on the α3β4 ganglion type nicotinic receptor in the adrenal ganglia/medulla as well as a central nervous system α4β2 nicotinic causing an increase in dopamine and epinephrine contributing the relaxation or happiness associated with inhalation. As it increases cholinergic (neuron receptor proteins) and adrenergic signalling, this impedes apoptosis (programmed cell death) which is essential for preventing the onset of tumours. Nicotine also stimulates angiogenesis and neovascularisation. The be all and end all is that nicotine itself can cause cancer and a result, so can e-cigarettes. On the plus side they do not possess the fatal ailments directly associated from tobacco smoking and levels of nicotine can be altered by purchasing varying strengths of cigarette liquid.

I hope that these messages are slightly clearer than the SMOKING KILLS note that is now compulsory for all smoking products, although in my opinion if the product you are consuming directly tells you it will kill you it’s a pretty clear sign to avoid it. 

The Hangover

As I managed to dodge one despite a heavy session on Saturday night, I thought it seemed a good use of my time to write about them. They are an inevitability. I have not met one person yet who drinks and has not been crippled by a hangover at some stage to the point where death would be welcomed just to get rid of the horrors of the morning after. Normally, a hangover has standard symptoms: nausea, dizziness, tiredness, headache, aches and pains, photophobia (sensitivity to light), trembling and the fear. But what causes all of the adverse effects and why do they only kick in the next morning? And most importantly can we cure it?

First things first. Alcohol is a toxin. Defined in chemistry as an organic hydrocarbon compound containing a hydroxyl croup. The type that is present in alcoholic drinks is ethanol which is a byproduct of yeasts metabolic process. It is also produced during germination of many plants. Ethanol is a central nervous system depressant. In small doses it acts as psychoactive drug whereby is causes a sense of euphoria, talkativeness and relaxation. However, as you increase the blood alcohol content, you also increase the risks of alcohol poisoning.  I had always thought that when drinking, you lose a fairly large proportion of alcohol through sweating and urine however in actual fact, only 2-8% is disposed of this way, the rest has to be metabolised. When ethanol is degraded by the enzyme alcohol dehydrogenase in the liver**, it is first broken down into acetaldehyde, which is further broken down to acetic acid radicals. Unfortunately, acetaldehyde is a poison that causes immflamation and is closely related to formaldehyde and is thought to be a major contributor to hangovers. Acetaldehyde is degraded fairly quickly by acetaldehyde dehydrogenase and glutathione and if you only have a couple of drinks, it won’t have time to cause any harm. The issue lies in the limited store of glutathione in the liver which cannot handle larger amounts of alcohol, allowing acetaldehyde to accumulate, leaving the toxin in the body for a prolonged period of time.

Process of ethanol metabolism to acetaldehyde (toxin) and finally to acetic acid.

The reason you become dehydrated after consuming alcohol is due to the inhibition of anti-diuretic hormone. This hormone is responsible for maintaining a fluid balance and hydrated state by making you pee out water in your body. You may notice that drinking makes you urinate more and that is a result of depletions of anti-diuretic hormone. You also lose a lot of key electrolytes (salts) in the process. Dehydration itself causes sickness, headache and dizziness on its own. Combine that with the other side effects of alcohol consumption and there is really no wonder why you feel so dreadful first thing the next morning.

Drinking alcohol also induces what is known as the “glutamine rebound”. Hangovers are suggested to be worse due to lack of sleep and it has been found that after a night of alcohol consumption, a drinker won’t sleep soundly. This because alcohol inhibits glutamine, a natural stimulant (thus the sleepiness associated with drinking). Post-drinking, the body over-produces glutamine to make up the difference and as a result causes a restless sleep as well as tremors, anxiety and increased blood pressure

To summarise there are 3 true causes of hangovers:

1. Acetaldehyde toxicity

2. Dehydration

3. Glutamine rebound

The causes of hangovers makes them so difficult to cure. Because consumption of alcohol inhibits certain hormones as well as relying on the finite reserves of natural chemicals, there is no sure fire way of ridding yourself of the sickness, headaches and chronic fear. However Irn Bru, a fry up and a cuddle is a close as any scientist has come so far.

Possibly the worst symptom of a hangover. This picture could not be more accurate.

**Ethanol is not exclusively broken down by alcohol dehydrogenase, other enzymes do contribute but I could spend a whole other (less interesting) post on alcohol metabolism.

Ebola - Should we be concerned in Scotland?

The short answer is Yes. I had never intended on beginning this blog on such a morbid note but I felt with the current situation regarding Ebola spreading to western countries, I believe it is pretty relevant and hope that I can provide a better understanding of the dynamics of the disease.

I have a fascination with diseases. By detaching from the harm and suffering they cause, the way in which they interact to immune systems and pharmaceuticals captivates me. I had always believed that when we feel feverish due to illness, that was the bug causing us to feel unwell, but it is in fact our body raising its own temperature to make it a less hospitable host to the infection. Basically, we make ourselves ill. Now, at some stage I would like to write short entries on other diseases and how they interact with the body but as it is topical I will overview Ebola.

Ebola is a zoonotic virus meaning it reservoirs non-pathogenic within a host before being passed to another susceptible host for the virus to take effect. Ebola, amongst other viruses, are carried by bats however, there has been little evidence as to why they are not affected by the disease itself. Some hypothesis suggest that the rapid and significant body temperature and metabolism increase bats incur during flight is adjuvant to an effective immune response. Frighteningly, humans and primates do not possess the ability to fend off the infection. A study in 2006 revealed that as Ebola spread across central Africa, 90% of Gorilla populations were wiped out. At the time it was also noted that the mortality rate in humans was 80% and unfortunately, that figure has not changed.

The typical symptoms of Ebola after infection. As you can see it takes rapid effect and can be catastrophic.

The disease targets endothelial cells (lining of blood vessels), mononuclear phagocytes and hepatocytes. Upon infection, the Ebola virus glycoprotein is synthesised and replication overwhelms protein synthesis of infected cells and the host immune system. The glycoprotein also interferes with neutrophil signalling further helping it evade the immune system. The result is haemorrhagic fever with subsequent organ damage, leading to organ failure and death.

There is currently no vaccine or treatment available against the virus. This is not reason to panic as there are many labs all over the world currently working to find one. Certain procedures can help patients such as fluid and electrolyte balance to counter dehydration and the administration of anticoagulants early in the infection to control intravascular coagulation although these treatments still do not guarantee survival by any means. The best chance of fighting it is isolation and quarantine. The disease typically spreads via fluid transmission, ie and infected bat’s saliva contacting a hosts blood, introducing the virus (there has been instances of bats dropping part-eaten flats and passing the disease to mammalian hosts that way). At this stage there is very little evidence to suggest it can be transmitted through the air which is in some ways comforting as airborne transmission is a much more effective method of disease progression.

I hope the intent of this post is not misconstrued. I am opposed to media derived scaremongering with little evidence backing up their weekly “civilisation ending” catastrophe, be it war, disease, famine or something more nonsensical. I merely want to provide a bit more insight into the disease itself. I believe that if the disease is controlled properly then we will not face any danger as a civilisation and as individuals in the western wealthy world we should be relatively safe from contracting it (unless you visit central Africa or get particularly cosy with bats). So to go back on my initial answer to the question: in Scotland, we probably shouldn’t worry about Ebola. 

My only concern is failure to properly quarantine the disease. Aid and healthcare workers who have been flown back to america for better treatment could prove problematic if there is a breach in patient isolation. The recent story of 2 American humanitarians who have been released from hospital after receiving treatment with experimental drugs (http://www.theguardian.com/society/2014/aug/21/ebola-americans-released-hopsital-recovery-doctors) is also a bit dodgy. Releasing patients at this stage without knowing the long term effects could result in relapses of the virus.

Next time I plan on writing about more positive and cheery scientific stories however I cannot guarantee the odd disease cropping up that I find interesting.

A Welcome to Scientific Blogging

Welcome to my blog. 

I will be writing a far from from impartial and heavily biased account of recent scientific discoveries and stories of interest. I will do my utmost to make this not sound like bitching and moaning but I entirely intend to voice my opinions on common misconceptions on everyday topics.

A bit about me: I have recently graduated in animal biology and am a few months away from travelling the world. I one day hope to pursue a career in pharmaceuticals due to my interest in diseases and cell biology but for now I just wanted to keep myself stimulated by researching and writing this blog. 

I hope you enjoy it! I welcome comments and if I haven't been clear on some aspects or if I am wrong about something (which will happen, I guarantee that) please let me know and I will do my best to clarify.

Cheers,

Chris

P.S - Below is the only photo that I have appropriate for this blog, typically they would include alcohol or lack of clothing.