Injections of Medical Insights

HeLa cells are cancer cells taken from Henrietta Lacks in 1951. Normally, cancer cells would divide a few times before dying. However, these specific cells kept dividing so long as they were fed with the right mixture of nutrients. These cells were thus “immortal” and responsible for numerous medical breakthroughs.  HeLa cells have become the most widely used human cell line in biological research. They were used in 1954 to develop the polio vaccine and were also used in the 1980s to identify and isolate the human immunodeficiency virus (HIV). Over 70000 studies of research have been published involving the use of HeLa cells, and at least two Nobel Prizes have been awarded.  HeLa cells have provided scientists and researchers a human cell line to conduct their research for the past 70 years. Without these cells, many medical breakthroughs would not have been possible.  However, there was also an ethical lapse in obtaining these cells. Henrietta Lacks’s surgeon conducted a...

No one in the world has a fingerprint completely identical to yours, past, present or future. This mainly stems from the fact that the formation of fingerprints has too many variables to be accounted for and can never be accurately predicted. There are some general patterns that have been observed such as the loop, whorl, arch and the double loop whorl. Early on in foetal development, lumps of stem cell tissue known as volar pads grow beneath the skin of each finger. The formation of volar pads is determined by genetics, which attributes to why some relatives share the same general design to you. Despite so, the uniqueness of each fingerprint does not stem from the DNA in your cells but rather the way your fingerprints grow. Microscopically, the embryonic skin has 3 main layers; the epidermis, basal layer and the dermis. These layers are growing at different rates and are heavily affected by external variables. There are too many to account for, this makes the formation of fingerprints...

Lymphedema refers to swelling which generally occurs in the limbs. It is most commonly caused by the removal of or damage to the lymph nodes, causing a blockage in the lymphatic system. The blockage prevents lymph fluid from draining well, leading to swelling.  In addition to the swelling, patients with lymphedema may experience aching, recurring infections and hardening or thickening of the skin (fibrosis). Fibrosis occurs in the later stages of lymphedema, and further restricts the limb’s range of motion. If left untreated for long periods of time, lymphangiosarcoma - a rare cancer - may develop.  Lymphedema can be categorised into primary and secondary lymphedema. Primary lymphedema is a rare genetic condition caused by mutations. In contrast, secondary lymphedema is caused by procedures which damage the lymph nodes, such as surgery and radiation treatment for cancer.  While there is no cure for lymphedema, therapy is often used to reduce swelling and pain. Complex dec...

Conjoined Twins is a phenomenon when monozygotic twins are physically attached to each other before birth, sharing body parts ranging from bones to even renal openings. Typically, the embryonic layers of the cell will split 8 to 12 days after conception; these twins will then develop their own individual organs. However, the embryo of conjoined twins takes a few days longer to split after conception.  Before the splitting mechanism is complete, embryonic separation stops and the twins are conjoined. Conjoined twins are extremely rare, and this makes it difficult to determine analyse potential risk factors that may cause couples to have them. There are also no specific symptoms unique to conjoined twins, they only share the same symptoms as normal twins such as the uterus growing at a faster rate and expecting mothers can experience more fatigue than normal. Recently, improvements in surgical procedures have lessened the mortality rate of separating conjoined twins. Also, advances i...

Personalised medicine, also known as precision medicine, is a form of medicine that uses information about a person’s genes, proteins and environment profile to prevent, diagnose, and treat diseases.  While medicine has traditionally taken a reactive approach, this new methodology focuses more on a preemptive approach. Women with mutated BRCA1 and BRCA2 have a higher risks of suffering from breast cancer. Through personalised medicine, one will be able to know if they have the mutated gene, and can choose to surgically remove their breasts before developing the cancer.  With personalised medicine, clinicians tailor their recommendations to individual factors, which increases the effectiveness of the treatment. As the costs of genetic testing drops, and the usage of big data rises, there is greater accessibility for personalised medicine, improving the prospects of healthcare in the future.  Personalised medicine is an example of how medicine can continue to evolve in a bi...

Osteoporosis is a bone disease that occurs when there is too little bone or when the body produces too little bone. The word is derived from the terms ‘osteo’ which means ‘bone’ and ‘porosis’ which means porous. Compared to normal bones, the spongy bone has more holes or pores, weakening the structural integrity of the skeleton. Bone cels called Osteoclasts, break down bone tissue and Osteoblasts build bone using minerals such as Calcium and Phosphate. Hormones such as oestrogen and testosterone help to keep the number and activity of Osteoblast high.  There are 2 types of osteoporosis. Primary Osteoporosis is due to old age when Osteoclasts remove more bone than Osteoblast make. This usually happens after the age of 30 when adults reach their ‘peak bone mass’. Secondary Osteoporosis affects both children and adults and mainly stem from cancer, hormonal imbalances or certain use of medications. In severe cases, bones may become too weak to support the rest of the human body and is ...

Christmas disease, also known as haemophilia B, is a genetic disorder in which the blood does not clot properly.  Christmas disease follows X-linked recessive inheritance. As a result, the disease is almost exclusively found in males and much rarer in females. Queen Victoria and her family are carriers of Christmas disease.  The recessive alleles result in little or no production of factor IX. Factor IX is a protein that is naturally produced in the body which is required in the blood clotting process. Consequently, patients with Christmas disease experience prolonged and unexplained bleeding.  There is no cure for Christmas disease. However, one can be treated with factor IX injections. Patients with Christmas disease are also advised to avoid activities which increase the chances of bleeding. Sources: https://www.healthline.com/health/hemophilia-b#treatments https://hemophilianewstoday.com/hemophilia-type-b/ https://www.cdc.gov/ncbddd/hemophilia/facts.html https://hemop...

  In 1990, a publicly funded project called The Human Genome Project aimed to determine the exact sequencing of the human DNA, base-pair by base-pair. 20 international research centers collaborated on finding out the exact sequence of the human genome which lasted up to 13 years since. Inside every cell of your body there is DNA measuring 3.2 Billion base pairs long. It is divided into smaller portions using enzymes, making it more manageable to sequence. These reduced genes are injected into artificial bacteria and then divide, revealing finger prints in labs which let scientists know which genes are overlapped, allowing them to attach each gene together. Each portion is further divided into smaller portions, measuring at approximately 1000 base pairs long; they are shipped to the 20 different labs all around the world, using the aforementioned method, and are further checked to maximise the accuracy of the gene sequence. Each piece of genome is determined using a computerised met...

Atopic dermatitis, more commonly known as eczema, is a skin condition that appears as a red rash with flaking skin or as small blisters.  Allergic reactions are a significant trigger for itching. These include pollen allergies as well as allergic reactions to animal dander. Infections such as herpes virus infections can also cause a severe skin reaction.  A survey showed that 21 percent of children and 11 percent of adults suffer from eczema in Singapore, with half of the cases having the skin condition throughout their lives.  Common medications for severe cases of atopic dermatitis include steroids. Steroids act as an immunosuppressant, which will reduce the inflammation and itching in the skin, thus allowing the skin to heal.  Sources:  https://nationaleczema.org/eczema/treatment/topicals/ https://www.mayoclinic.org/diseases-conditions/atopic-dermatitis-eczema/symptoms-causes/syc-20353273 https://www.healthhub.sg/a-z/diseases-and-conditions/16/atopicdermatiti...

Dyslexia is commonly known as the difficulty to read words that Dyslexia see things backwards. i.e They see d as b, vice versa. Instead, Dyslexia is a phonological processing problem. Dyslexic individuals do not have trouble seeing the language, but rather they have problems manipulating it. They have trouble connecting sounds of individual letters which make up a word, taking them a longer time to read and internalise the sound and meaning of words. Hence, Dyslexia makes it especially difficult to break down multi-syllabi words such as “beautiful”. Dyslexia affects about 1 in 5 people and it may also be hereditary. It runs in the family but does not affect everyone in it. One family member may have dyslexia and the other may not.   There are 2 hemispheres in the brain. The left hemisDphere is responsible for language and reading, whereas the right is responsible for spatial activities. Dyslexic individuals rely more on the right and frontal lobe of the brain. They have reduce...

Alzheimer’s disease is a progressive disorder that causes brain cells to degenerate and die. It is the most common cause of dementia.  Gradual memory loss is the key symptom of Alzheimer’s disease. However, it can also lead to inability to make judgements and decisions and change in behaviour and personality.  A combination of genetic, lifestyle and environmental factors causes neurons to be damaged and eventually die. The presence of beta-amyloid plaques and a change in conformation of tau proteins into neurofibrillary tangles are identified as potential causes of Alzheimer’s disease.  Beta-amyloid plaques appear to have a toxic effect on neurons and disrupt cell-to-cell communication.  Likewise, the neurofibrillary tangles disrupt the transport system in the brain and are also toxic to the neurons.  Researchers have thus identified these two factors to be the most likely cause of Alzheimer’s disease.   Alzheimer’s disease is not preventable. However,...

Anaphylactic shock is a severe allergic reaction which sends your body into shock, depleting it of oxygen. The body gets “shocked” when blood pressure drops and bodily cells (thus organs) do not receive sufficient oxygen. Symptoms range from the nasal area such as coughing and sneezing to dizziness or weakness. In some severe cases, anaphylaxis can lead to death. An antigen crosslinks to IgE (Immunoglobulin E) and binds to the receptor on the Mast Cell. This is known as Cell signalling. When this happens, a cascade of reactions occur and Mast Cells releases histamine. Histamine increases the permeability and dilates blood vessels which causes blood pressure to drop, leading to shock.  Inflamed tissue looks red because there is more blood in dilated blood vessels. Also, the increased permeability of blood vessels allows fluid to enter which causes swelling. As a result, the swelling increases the tension in nerve tissues by pressing against them, and this leads to itchy and/or skin ...

  Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is a repeating sequence found in bacteria. When a bacteria fights off a virus, the virus’s genetic code is broken down and stored in CRISPR spaces in the bacteria’s genome. Upon a viral infection, an enzyme called Cas9 then chops the viral genome if it matches the sequence in the CRISPR spaces.  By using artificial RNA in the CRISPR space, Cas9 can then be used to cut anything with the same code. CRISPR can thus be used to remove undesirable genes, and also harness repair enzymes to substitute desired genes into the space left by the snippers.  Beyond the CRISPR/Cas9 system, other systems such as CRISPR/Cas13 have also been found. While Cas9 is used to edit DNA, Cas13 is found to edit RNA.  The potential for CRISPR technology is endless. On a basic level, CRISPR can be used to remove genes coding for diseases and replace it with a normal gene. CRISPR can also be used to experiment on the different g...

  Poliomyelitis, or Polio for short is primarily known for its paralysis in patients. Poliovirus can multiply in specialised cells in the intestines which enters the bloodstream to invade the Central Nervous System, where it spreads along nerve fibres and multiplies. The virus destroys nerve cells (Motor Neurons) which cannot regenerate. Consequently, nerve impulses are unable to be transmitted to skeletal muscles, causing paralysis.  Poliovirus also attacks the motor neurons of the brain stem, damaging breathing capacity and causing difficulty in swallowing and speaking. Without respiratory support, polio can result in death. Hence, many patients whose conditions were severe required a metallic cylinder infamously known as the “Iron Lung” for breathing support. The Iron Lung functions by creating a vacuum within itself. This air pressure in the Iron Lung will be reduced, relative to that of the atmosphere, forcing oxygen into the patient’s lungs. Poliovirus is highly contagio...

  Arthritis is the swelling and tenderness of the joints. There are many different causes of arthritis, but the most common types are osteoarthritis and rheumatoid arthritis.  Osteoarthritis occurs when the cartilage between bones in the joints gradually deteriorates. Eventually, the cartilage can wear down completely, causing the bones to rub against each other.  On the other hand, rheumatoid arthritis is an autoimmune disorder and occurs when the immune system mistakenly attacks the body’s tissues. Rheumatoid arthritis can eventually result in bone erosion and joint deformity, as well as cause physical disabilities in severe cases.  Painkillers and non-steroidal anti-inflammatory drugs (NSAIDs) are prescribed to reduce pain and inflammation in the joints. In the case of rheumatoid arthritis, disease-modifying anti-rheumatic drugs (DMARDs) are also used to slow or stop the immune system from attacking the joints.  Other forms of treatment also include physical ...

Action Potential An action potential is an electrical charge that travels along the membrane of a neuron. This occurs through depolarising and repolarising of the membrane.  The differences in concentration of potassium and sodium ions across the membrane creates an electrical charge of -70mV. This is called resting potential.  During depolarisation of the membrane, sodium ion channels open, allowing sodium ions to enter the cell, increasing the positive charge inside the cell. This starts the action potential. Potassium ion channels then open, and potassium ions flow out of the cell, causing the inside of the membrane to become negatively charged and thus repolarising the membrane. This ends the action potential.  Action potential works on an all-or-nothing basis. A threshold of  -55mV has to be reached for an action potential to begin. An action potential transmits electrical impulses through the neuron’s axon and to the synapses. Consequently, this allows the brai...

The UK was the first country to approve the Pfizer COVID-19 vaccine for widespread use in the country, with a 90 year old grandmother being the first to receive the vaccination outside of a trial.  The phase 3 clinical trial data showed that the vaccine was more than 90 percent effective, and that BIPOC (black, indigenous, people of colour) communities had higher rates of COVID-19 infection as compared to white, non-Hispanic communities.  The vaccine contains viral mRNA which codes for the spike glycoproteins found on the outer surface of the virus. The human cell reads the mRNA and translates the proteins and no other part of the virus. The presence of the glycoproteins triggers an immune response where the body produces antibodies to remove the viral glycoproteins. This will allow the body to fight infections from COVID-19 in the future.  However, there are also several issues with the vaccine. The most pressing is the storage of the vaccine. The drug has to be stored a...

Thalassemia is a blood disorder that causes your body to have less haemoglobin than normal. As a result, thalassemia can cause anaemia and will leave the patient feeling fatigued.  Thalassemia is caused by mutations in the DNA of the cells that make haemoglobin. In thalassemia, either the alpha or the beta chains are reduced, resulting in alpha-thalassemia or beta-thalassemia respectively.  The alleles for the thalassemia are recessive. Hence, many carriers do not realise that they carry the allele. Four genes are involved in making the alpha haemoglobin chain. The greater the amount of mutated genes, the greater the severity of the disease. Two genes are involved in making the beta haemoglobin chain. Likewise, having two mutated genes will result in thalassemia major, a more severe form of the disease.  Family history of thalassemia increases the risk of a patient having the disease, as the disease is hereditary. Thalassemia most often occurs in African Americans as well...

Diabetes is a group of diseases that leads to  the body to be unable to get sugar from the blood into the cells, also leading to high blood sugar levels.  Type 1 diabetes is a chronic condition in which the pancreas produces little or no insulin. This is because the body’s own immune system mistakenly destroys the beta cells of the islet of Langerhans. Type 1 diabetes has no cure.  In contrast, type 2 diabetes arises due to a change in the way the body metabolites glucose. The exact cause of type 2 diabetes is unknown, but risk factors include being overweight, lack of exercise and family history of type 2 diabetes.  In the long term, diabetes can lead to severe complications such as heart and blood vessel disease, nerve damage (neuropathy), and kidney damage (nephropathy) among others.  Worryingly, the incidences of diabetes in Singapore has risen to 11.3% in 2010. In 2016, a war against diabetes was spearheaded by the Ministry of Health. This included greater ...

Prion is a term used to describe the mysterious infectious agent responsible for several neurodegenerative diseases such as Creutzfeldt-Jakob disease. The word refers to Dr Stanley Prusiner’s hypothesis of the infectious agent causing these diseases. This hypothesis explains why the infectious agent is resistant to ultraviolet light, which would typically kill the agent by damaging the DNA/RNA, but is instead susceptible to substances that disrupt proteins.  Prion diseases include Creutzfeldt-Jakob Disease and Kuru in humans, as well as Bovine Spongiform Encephalopathy and Scrapie in animals. They are distinguished by characteristic spongiform changes associated with neuronal loss and failure to induce inflammatory response.  The prion protein was discovered to be encoded by a gene (PrP gene) found in all animals examined, including humans. The infectious prion protein was caused by a mutation in the PrP gene. These studies argued that prion diseases can be inherited and infec...