Cystic fibrosis is a genetic condition where the lungs and digestive system are clogged by mucus. It is the second most life-shortening inherited disorder in the United States, proving its seriousness. The symptoms include persistent coughing, recurring lung infections and poor weight gain.
Saturday, 20 February 2016
Hydrocephalus is a condition caused by an abnormal build up of fluid in the brain’s ventricles or cavities. Although in 2015, 400,000 newborns were born with this condition, treatment of hydrocephalus is still lacking, particularly in developing countries. In Uganda, neurosurgeons number 1:10,000,000 showing the urgency for more qualified staff. In the past, the fluid was thought to have been water, hence the term ‘hydro’. Now the fluid has been identified to be cerebrospinal fluid (CSF), a clear liquid that surrounds the brain and spinal cord.
|Baby with hydrocephalus|
The main purposes of CSF are to keep the brain tissue buoyant, act as a transport medium, and to compensate for the changes in intracranial blood volume (the amount of blood within the brain). Every day, the brain produces half a litre of CSF a day, with the old fluid being released from the brain to be absorbed by blood vessels. If this process were to be interrupted, the ventricles would be forced to enlarge in order to accumulate the large volumes of CSF, resulting in greater pressure on the brain.
There are two ways of developing hydrocephalus: congenitally or acquired. Congenital hydrocephalus is present at birth. It can occur due to abnormal foetal development or genetic abnormalities. Most often, these abnormalities are bleeding in the foetus during development or as a result of certain infections from the mother, such as syphilis.
Acquired Hydrocephalus occurs at birth or after. This could be from physical injury such as a head trauma. It is then identified as Normal Pressure Hydrocephalus (NPH), occurring often in those over the age of 60.
The physical symptoms of hydrocephalus can be easily identified, as the condition causes a baby’s head to grow at an abnormal rate. Fibrous material between the five bone plates allow the head to grow after birth. However with hydrocephalus, these sutures become abnormally large and the frontanelles (the area where sutures meet) bulge due to pressure from the build-up of CSF.
This pressure can cause significant brain damage, triggering mental problems. The classic triad for NPH consists of an abnormal gait, urinary incontinence, and dementia. This is due to NPH affecting the parts of the brain controlling the legs, bladder, and the "cognitive" mental processes like memory. Since this classic triad of symptoms are similar to those of Parkinson’s disease and Alzheimer’s, NPH is often misdiagnosed. Normal pressure hydrocephalus can be accurately identified through neurological examinations, commonly CT scans. The images produced can aid doctors and surgeons when performing shunt surgery, which has failure rates ranging from 40 to 50%.
Shunt surgery can only treat not cure NPH. During this procedure, a neurosurgeon would implant a long tube with a valve into the ventricle of the brain, to drain away excess CSF. Increase in pressure would cause the valve to open, releasing the fluid through the tube and allowing it to flow in one direction only. The tube leads into the peritoneal cavity, where CSF can be absorbed safely into the bloodstream, preventing any build up of CSF in the brain.
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Wednesday, 17 February 2016
Regeneration is one of the ultimate abilities that humans lack, however the axolotl native to Lake Xochimilco in Mexico has cracked this long searched for secret.
They have recently become infamous for their bizarre smile, but more importantly in the scientific world, their perfect display of regeneration and neoteny. This is where instead of developing until the peak of adult form, axolotls maintain their juvenile characteristics such as retaining external gills and lidless eyes. Therefore aging is of little concern and so is the fear of losing a limb or two as all complex anatomical structures can be grown in a period of months.
|Example of neoteny in apes|
Scientists have tested the axolotls’ miraculous regeneration by amputating their limbs and discovering that ‘’they can regenerate the same limb 50, 60, 100 times. And every time: perfect."
|Axolotl's regenerative abilities|
The cells at the site of amputation become pluripotent, this is the ability to differentiate, similar to embryonic stem cells. A blastema forms on the wound as a clustered mass of the pluripotent cells which finally develop into a fully functional limb. Scientists at the TGF-β1 in particular increase during the formation of the blastema, and when inhibited, little regeneration development is displayed. Similarly, p53 showed to also be essential in the axolotls’ regenerative pathway.
Fortunately, a connection has been made between humans and the axolotl, with both species sharing the compounds p53 and TGF-β1.
Currently, scientists are still distant from successfully transferring the relationship between the two proteins to humans in order to share the regenerative abilities of the axolotl. However, the salamander has introduced a hope in the scientific world that the possibility of becoming fully dependable on our own regenerative abilities will no longer be a secret.
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