Sunday, 30 November 2014

Diabetes

Diabetes (Diabetes Mellitus) is a life long condition, suffered by over 3 million people in England, in which the body is in capable of controlling it blood-glucose concentrations. It can be a huge problem if left alone as body tissues are in constant need for glucose for respiration, especially the brain as glucose is the only respiratory substrate it can use. It is essential that diabetes is diagnosed soon so that measures can be taken to re-control the blood-glucose concentrations.

Insulin and Glucagon are hormones that are used to control blood-glucose concentrations at a steady 4-6 mmol/dm^3. Insulin promotes glucose uptake in liver cells and to get converted into glycogen for storage (Glycogenesis), lowering the blood-glucose concentrations. Glucagon increases glucose concentration in the blood by causing the breakdown of glycogen back into glucose (Glycolysis) or if need be, the creation on new glucose from fats and amino acids (Gluconeogenesis)9. Both of these chemical messengers are created in the Islets of Langerhan in the pancreas.

There are 2 types of Diabetes which are very conveniently named type 1 and type 2 diabetes. Type 1 is an autoimmune disease that starts in children, a disease where the body's own immune system mistakes the Islets of Langerhans as foreign and starts attacking and destroying them. Type 1 diabetes is spontaneous and you're more likely to get it if its existed in your family but can also happen randomly. Type 2 diabetes is when the body cells slowly become more and more resistant to insulin, this happens to everyone and some experts say that everyone who lives up to 120 year will have diabetes. However, the process of insulin resistance can be accelerated by the use of more insulin in the body then normal, like having a sugar rich diet or being obese.

There really isn't any cure as such for diabetes, but patients have to become at least part of the body's control mechanism. Patients are advised to
-increase consumption high fibre foods
-eat foods that are low in fats
-eat fish and lean meat
-eating fruits and unsalted nuts

These not only help patients, but also help lower the chances of getting type 2 diabetes in the first place. You can also be asked to take Metformin tablets which reduces the amount of sugar that is released from the liver. Sulphonylureas can also help by promoting an increase in the amount of insulin produced.

As for type 1 diabetes, patients will need to take full control of the blood sugar levels, having to measure the glucose levels in samples of blood and to inject insulin according to what's being eaten at every meal. This can be a very difficult to
get used to, especially as it children who get it. life has been made slightly easier by the invention of pumps that inject the required insulin while only needing to be changed once every 3 days. Researches have been looking into ways of measuring blood glucose levels without taking any blood.
http://www.rsc.org/chemistryworld/2014/11/diabetes-glucose-through-skin-spectroscopy 


Now there's something to stroke your goatee on!





Sources
http://www.who.int/mediacentre/factsheets/fs312/en/
http://en.wikipedia.org/wiki/Diabetes_mellitus
http://www.nhs.uk/Conditions/Diabetes/Pages/Diabetes.aspx
http://www.nhs.uk/Conditions/Diabetes-type2/Pages/Treatment.aspx
http://drhyman.com/blog/2010/05/20/are-diabetes-and-insulin-resistance-reversible/#close
http://www.inputdiabetes.org.uk/alt-insulin-pumps/what-is/
OCR A2 Biology Student Book

Sunday, 16 November 2014

Locomotion - Birds

We've had a look at human locomotion but in all honesty we are rubbish compared to some of the animals that are out there. First off, when considering locomotion, it is quite clear the that the most impressive animal group has to be the birds. They contain some of the fastest of all animal, they can travel the furthest and over the roughest terrains they are completely fine.

There are some amazing feats of locomotion within birds, the one that stands out for a lot is the shear speeds that they can achieve. The fastest animal by far is the beautiful Peregrine falcon, achieving speeds of up to 289 km/h in their speed dives used to catch its pray. However, in terms of horizontal speed, the golden eagle is faster, moving at speed of      129 km/h compared to the 110 km/h.

Seeing the Wandering Albatross is a wonderful sight, having the largest wingspan of up to 3.5 m allows it to become an incredibly efficient flyer. I have to say this bad-ass has to be my favourite bird. These 8 kg birds live most of their 70 year long lives in the air, that's right. They're able to fly for thousands of miles without ever flapping. Albatrosses live mainly in oceans of the southern hemisphere and it just a phenomenal organism. Oh, by the way, it travels around 25,000,000 km in its life (to the moon and back 18 times!)

There are however, downsides to being a bird. Travelling through the air is much more energy demanding then both land and sea location. The pectorals are the muscles that are responsible for the powerful wing strokes actually makes up 15 to 20% of its total mass. Pectoral contractions don't instantaneously result in movement, meaning that its response time is a lot slower to say a lynx and so allows the them to catch birds before they have enough time to fly away (however for an albatross this is not an issue!).

Oh and this is a little Treat!
https://www.youtube.com/watch?v=VjE0Kdfos4Y

Now there's something to stroke your goatee on!




Sources

Friday, 7 November 2014

Rabies Battle Plans

Rabies (meaning madness) is a neurological disease that causes very serious inflammation (encephalitis). This is when the brain reddens and swells causing extreme headaches, fever and confusion. Rabies is often lethal when it gets to its latest stages, its transmitted from affected animals (mostly dogs and bats) onto humans though saliva via scratches and bites. Early symptoms include fever and tingling ate the site of the bite. When systems of fear of water, violent movements, uncontrolled excitement or lack of conciousness start to show, often within one to three months, it is an indication that the victim is unlikely to survive.

Rabies causes around 40,000 deaths per year and has spread to over 150 countries. Recently though, a study from Tel Avive University found to precise pathway that the pathway takes to the central nervous system (CNS) where it erupts into the symptoms. The study was conducted by Dr. Eran Perlson and Shai Gluska.

"Rabies not only hijacks the nervous system’s machinery, it also manipulates that machinery to move faster," said Dr. Perlson. "We have shown that rabies enters a neuron in the peripheral nervous system by binding to a nerve growth factor receptor, responsible for the health of neurons, called p75. The difference is that its transport is very fast, even faster than that of its endogenous ligand, the small molecules that travel regularly along the neuron and keep the neuron healthy." 

Rabies, as it turns out, hijacks the transport system of the neurones. The transport system, consisting of the cytoskeleton, is used to move around cell contents so that it can function. The researches 'saw' the virus hijacking the system and head straight towards the spinal cored (part of the CNS).


"A tempting premise is to use this same machinery to introduce drugs or genes into the nervous system," Dr. Perlson added. This is a very rapid system of transport and is one of the reasons why rabies quickly becomes deadly. However, Dr Perlson points out that we could take advantage of this mechanism to create the next generation of faster acting and efficient pharmaceuticals. Knowledge of such pathways can also help us with the elimination of neurodegenerative disease like Alzheimers and Amyotrophic Lateral Sclerosis (ALS). 


Now there's something to stroke your goatee on!






Sources
http://inside-the-brain.com/tag/rabies/
http://en.wikipedia.org/wiki/Rabies
http://en.wikipedia.org/wiki/Encephalitis
http://www.aftau.org/weblog-medicine--health?=&storyid4704=2113&ncs4704=3

Images
http://www.ijm.fr/recherche/equipes/trafic-membranaire-normal-pathologique/