The Power of the Potato

I am extremely lucky to have a family roast dinner every Sunday and fish and chips every Friday lunchtime but in the light of the recent potato scandal this may change.

The Food Standards Agency, who research about food safety and nutrition-related diseases in order to make the UK population’s food as safe as possible, have noticed a link between cancer and foods full of starch that are cooked at high temperatures. New Scientist magazine have suggested that this is due to ‘sugars and amino acids reacting together’ on heating to release chemicals. The chemical that the FSA are most concerned about currently is acrylamide which is said to be a carcinogen (causes cancer). There is no scientific evidence for this link in humans, however acrylamide does not seem to be a very healthy chemical to be ingesting.

Acrylamide is C3H5NO which is prop-2-enamide and decomposes without heat to form ammonia, carbon dioxide, carbon monoxide and nitrogen oxide, putting it on the US’s list of extremely dangerous substances. It is clear why we should not be ingesting this dangerous substance from what we know from basic GCSE knowledge that carbon monoxide is a colourless, odourless gas which binds irreversibly to haemoglobin, in turn preventing oxygen forming oxyhaemoglobin and therefore causing cells to respire anaerobically. Ammonia is also a very unpleasant, pungent smelling gas (at school we only use dilute ammonia in chemistry lessons due to its smell and it also being known as an ‘extremely dangerous substance’.)

In the body acrylamide is thought to cause damage by converting to another compound causing DNA mutation during transcription. This can lead to uncontrollable divisions of cells in the body in numerous locations. [Please read my skin cancer blog for more detailed information about a particular cancer.]

The FSA’s hypothesis that acrylamide causes cancer derives from their study of giving water containing different concentrations of acrylamide to rats and mice in laboratories. The results from this were that several cancers were caused however we do not know if this is the same in humans as it would be unethical to do the same test on humans.

Interestingly, as waste water is treated with this chemical, it has been estimated that one glass of water contains around 500 times the amount of acrylamide as one portion of roast potatoes! Perhaps we should be worrying about our water intake instead!

This leads me to believe that we do not have to cut out roasted potatoes, baked jacket potatoes and fried chips all together but should reduce our intake or cook them at a lower heat and for less time in order to significantly decrease the amount of acrylamide entering the body. The FSA’s official advice is to ‘go for gold’ in colour of starchy foods, check the packaging for recommended cooking instructions and to not keep raw potatoes in the fridge releasing more sugars that could bind to amino acids making acrylamide when heated.

 

Emily Buchanan

 

‘Hospital’ – BBC 2 Documentary Episode 3

Today’s episode was a fascinating insight into Charing Cross Hospital’s Neurosurgery department including some clips from inside the operating theatre, as well as interviews with patients, their families and a consultant about his view of the NHS’ waiting time problems and whether outsourcing should be used for more patients. During this episode, it was estimated that there are 10,000 neurological surgeries per year – this figure is particularly high at Charing Cross hospital due to its impeccable reputation and high success rates.

The majority of the program was centered around the fight between consultants and doctors for the highly sought after intensive care beds (IC) beds which are used for patients after a major operation, patients with major trauma and at least one must be left in case of the arrival of an emergency patient. The fight for beds in this episode was shown by the waiting times for planned neurosurgical operations which were all around nine months. This is absolutely unacceptable as seeing similar specialists in Germany is said take only “two to three weeks”.

I often find when watching Hospital that I feel stressed and bothered by the content due to the extensive waiting times and the extremely large-scale organisation and planning that has to be done by consultants and doctors. I feel that this is cleverly shown by the producers of Hospital in order to make you gain an understanding of how healthcare professionals are feeling working for our NHS. Every person in the United Kingdom should be watching Hospital in order to get a taster of how our doctors are feeling in our current overstretched NHS system so that the population can unite to bring about change.

In this episode I was particularly unnerved when brain surgeon Kevin O’Neill made tough decisions about whether to consider operating on his next patient later that day whilst operating on a brain with multiple aneurisms. He spoke of his wasting of time “chasing, phoning and waiting” to be given permission to start his operations when he should not have to worry about beds, and should be able to spend his time operating on more patients. I noticed in one particular instance there was (once again – like in episode 2) an incident where there was no ward bed available for a person coming out of intensive care as there was a problem with discharging the patient. This has a knock-on effect throughout the hospital as consultants cannot start their operations until there are intensive care beds available for post-operation.

Throughout the meetings of the consultants with the organised administration staff, consultants were constantly stressing the importance of remembering that every operation must never be treated as a number (which is sometimes hard for people to understand due to the enormous number of patients) but must be treated as a patient in every individual case. This is one of the most influential reasons that consultant Kevin O’Neill does not support outsourcing to private hospitals. He stressed the importance of continuity of healthcare professionals throughout a patient’s medical journey as the patient and their doctor form a relationship which in turn helps to maintain standard of care. I believe that once patients are seen and have operations they are treated correctly and with respect throughout their procedure and during their recovery period, however, as one patient said “the bit before that is a disaster, an absolute disaster”. He had been waiting for his operation for nine months.

The part of this weeks episode that interested me the most was the showing of non-invasive ultrasound brain surgery. [I read about something similar in last week’s New Scientist (14/1/17) about transcranial direct current stimulation (tDCS) to treat tinnitus, depression and strokes.] This newly found ultrasound surgery was shown to treat a problem deep in the brain causing constant shaking (tremor) of the arm. I hope to find out more about this surgery as I believe that this is the key to future operations, saving doctors time, equipment and beds, allowing more patients to be saved in a far shorter amount of time.

 

Emily Buchanan

‘Hospital’ – BBC 2 Documentary Episodes 1 & 2

Two programs have been shown so far from the current BBC 2 series ‘Hospital’ in which St Mary’s hospital in Paddington opens its doors to BBC cameras to reveal the truth about the NHS crisis. I believe it is extremely important that as many people of the British public as possible watch the program in order to understand exactly where problems currently lie in the NHS. I believe that the more people that we educate about the crisis and expose major flaws in the system, the more likely we will be able to persuade the government to spend money on a solution. The tax payer funds the NHS and therefore it is their decision as to how it is run.

It was very interesting to see that highly qualified consultants had to wait around and check for beds, wasting precious time of which could be spent with a patient or researching. Before I watched ‘Hospital’ I did not think that this job is done by a surgeon but by skilled administrative staff.

Lack of beds is shown as the biggest problem at St Mary’s. Whilst a team of 14 people arranged their day around performing an operation, the operation did not end up taking place due to no ICU bed being available for after the patient’s operation. Many emergency trauma patients were coming into the hospital via emergency ambulances, taking up the precious ICU beds. I learned that beds will be given to patients in order of priority. This is extremely understandable as they would like to help as many patients as possible and if someone is near death they must treat that case first, using up any pre-arranged and less urgent beds. However, this is extremely frustrating for patients who have pre-arranged ICU beds as they mentally prepare for their operation and are often sent home, having to wait another four weeks or more. These last minute cancellations of arranged operations mean that doctors waste their days waiting around and have to spend time rearranging the surgery. If there were more beds available, all planned operations, along with emergency operations, could take place and doctor’s would no longer have to worry about rearranging appointments and checking availability of beds for a ‘go ahead’. A delay in appointments on one day also means rearranging future appointments in order to fit the rearranged operation in the consultant’s schedule.

I saw that ward beds were also wasted due to the fact that there was no care system put in place as an intermediate step between hospital and home. If there was an intermediate step, people could be discharged from hospital wards safely with the reassurance that they will be looked after for as long as needs be, whilst not putting a strain on the hospital beds that are in extremely high demand. There must be a better care plan put into place for elderly people who are discharged from hospital as they are weak and particularly vulnerable. Currently, these elderly patients stay in A and E until they are completely better – this wastes bed space and equipment and means that consultants cannot get on with their job as there are no beds available for the patients that need them. The day we tighten up discharges from hospital is the day that we will see more beds available, more people being saved in a shorter amount of time and less wasting of doctors’ precious time.

I learned more about a healthcare professional as a role in society as opposed to solely a profession as a nurse feared to discharge a patient who was well enough to leave due to him having nowhere to go as he is homeless. This is another clear case of failing in the discharge system. The man spent a week in the hospital after he was well enough to go home due to the fact that there is no recognised place for him to go. This wasted his bed and other precious resources. Nurses and doctors are taught to express their duty of care and this nurse showed her duty of care to the homeless patient as she spoke about showing the same amount of care whether the patient is “from Buckingham Palace or a park bench”. It was said that he could have been discharged a week earlier as he was fit enough to leave but was not discharged due to the nurse’s concerns of his future living plans. There has to be a recovery location available after stays in hospitals so that the nurses and doctors can be reassured that the patient’s condition will not deteriorate due to a poor environment during recovery and the bed can be used for the next patient.

I truly believe that this television program can change people’s opinions of the NHS – many people have the misconception that it is the doctor’s own fault that they have to wait so long to be seen or referred, and through this program they can see the true workings of a hospital and the number of hours spent catering for every patient’s needs. For me as a potential future doctor, I will use this program as an example of where I would like to see changes in our NHS whilst appreciating how lucky we are that every patient receives outstanding healthcare through the NHS, even though we may have to wait to be seen.

Many condolences to Peter’s wife and family – a truly brave, patient and appreciative man.

 

 

Emily Buchanan

The Truth about Skin Cancer

In order to understand the science that is extremely specific to skin cancer, we must first understand that the ‘choosing’ of genes and turning them into proteins is a series of events that is known as a cellular signaling pathway. The genes that are switched on control migration (movement of cells) and proliferation (generation of new cells). Cells proliferate first, then migrate to a desired destination and differentiate in order to carry out a particular function.

The type of cells affected by skin cancer are melanocytes which are mainly found on the skin and in hair follicles, named after the pigment melanin which they release to protect the skin from UV rays. As I previously said in my book review of Extreme Survival, melanin is found in greater quantities in people with darker skin colours and smaller quantities in people with lighter skin colours. The chemical is made up of the amino acid tyrosine and is also responsible for the colour of one’s eyes.

The gene that melanocytes express is called BRAF which has the MEK/ERK pathway as its cellular signalling pathway. The pathway allows stimuli to be relayed so that cells can respond to changes in the environment, by migrating and proliferating.

In my earlier blog today, about cyclophosphamide, I described cancer as an uncontrollable division of cells. If the chemicals controlling proliferation, migration and differentiation are not released or are misregulated, melanoma (cancer of the skin) is caused. The most common cause of melanoma is the replacement of thymine with adenine in the DNA base sequence of a BRAF gene so BRAF proteins made have their amino acid valine is replaced by glutamic acid which means that their shape (tertiary structure) of the is changed. The shape is changed so the part of BRAF activating the pathway for the MEK/ERK proteins is always active. Therefore, cells are always proliferating (uncontrollably dividing). This forms a primary tumour.

Secondary tumours are made by the migration of the large number of new cells around the body in the lymph and blood, known as ‘metastasis’. These tumours are more dangerous and aggressive than the primary tumour as rapidly dividing cells could be moved to key areas for survival such as in the bones, brain and lungs.

Treatment of metastatic melanoma includes Vemurafenib which is a drug specifically targeting the mutated BRAF protein and works by switching of the MEK/ERK pathway, therefore preventing excessive proliferation. In order to use these drugs, a doctor must first sequence their patient’s genome to ensure that it is the specific mutation in the BRAF gene that is causing the cancer.

 

Emily Buchanan

 

 

Cyclophosphamide – cancer can not hide

Today I wish to blog about an interesting drug that I have been researching, called Cyclophosphamide. I will talk about its uses, how it works, how it enters the body and its side effects.

The drug is both used as cancer therapy and to suppress the immune system. Whilst its use in suppressing the immune system for someone with nephrotic syndrome or its more common use during an organ transplant, due to us currently studying cancer in our A Level lessons I am keen to focus on Cyclophosphamide’s use in cancer treatment.

It is a chemotherapy medication that helps in the treatment of leukemia which is high numbers of abnormal white blood cells known as cancer of the blood, ovarian cancer, breast cancer, small cell lung cancer, sarcoma (more commonly known as cartilage or fat cancer), lymphoma (cancer of lymphocytes) and myeloma (bone marrow cancer) and also kills T cells.

Cancer is uncontrollable division of cells and naturally the body has mechanisms it puts into place, during the cell cycle, to prevent “normal cells” dividing when they come into contact with cancerous cells. However, cancerous cells bypass these mechanisms and continue to divide uncontrollably by mitosis.

The cell cycle is made up of two parts; interphase and mitosis. During interphase, the cell gets ready for division by going through the G1 phase, S phase and G2 phase. In the G1 phase, the cell doubles in size whilst organelle and protein are synthesised, whilst in S phase DNA replication occurs so that there are two clones of each chromosome. These chromosomes are renamed chromatin when they wrap around Histone proteins therefore after the clones have been made, these ‘sister chromatids’ are held together by a centromere. A fault in copying of DNA could lead to mutations so the cells are thoroughly checked in the G2 phase, and the presence of correct proteins for division is also checked, before continuing through the cycle to mitosis. Cancer cells bypass parts of the G2 ‘checking’ phase.

Cyclophosphamide works by disrupting transcription of DNA into RNA in dividing cancerous cells by sticking to DNA strands in cancerous cells. More specifically, the drug is converted into phosphoramide mustard which makes DNA cross-link preventing mitosis. Transcription is a key function of our cells, allowing genetic material to be passed from cell to cell in a protein code. Therefore, by disrupting transcription, the cell does not know how to divide so dies. Whilst disrupting transcription, this chemotherapy drug also causes cells to ‘commit suicide’ by apoptosis. Apoptosis is when the cell dies by its own disrupted nucleus or cell membrane.

Cyclophosphamide is an ‘alkylating’ drug which means that it is cell-cycle non-specific in medical terms which means that the disruption of transcription happens at all or any parts of the cell cycle.

To treat with cyclophosphamide, a cannula, portacath or PICC line is inserted directly into the bloodstream. A cannula is a thin tube directly inserted into a vein whilst a portacath is a catheter attached to a port under the skin where drugs can be injected. PICCs are peripherally inserted central catheters that are inserted into a vein above the elbow and are pushed through the vein into the chest. These ways of inserting the drug are very invasive and in some circumstances tablets may be used instead.

The largely talked about side effects of chemotherapy are due to the drugs not knowing the difference between a cancerous cell and a “normal cell” so all cells in the area are killed. The most commonly affected “normal” cells are in the blood, mouth, stomach, bowl and hair follicle. A side effect more specific to cyclophosphamide, is a decrease in white blood cells weakening the immune system due to the drug being cytotoxic and this means that you are more likely to get a cough or cold, for example. A second effect is that you may have a reduced number of red blood cells so are more likely to be anaemic and a decrease in platelets means that you bruise more easily. More noticeable effects are hair loss within the first 4 weeks of use and amenorrhoea which means stopping of women’s periods along with loss of fertility.

 

Emily Buchanan

 

News topic of interest: The three-parent baby

Three-parent families is a topic that particularly interests me due to its relevance now and for the future, allowing women with mitochondrial DNA mutations to have children. This is a topic of ‘personalised medicine’ which is an ever-increasing part of medicine that allows a patient’s treatment to be determined by their genetics. There are ethical issues surrounding personalised medicine due to the fact it is not considered a natural birth so is said to be ‘questioning God’ by the Church of England and encouraging ‘designer babies’ by the House of Lords. Altering nuclear DNA is banned by law in the UK with the exception of mitochondrial replacement.

Genetic medicine is very modern due to its reliance on new technologies such as oligoarrays. An oligoarray analyses nucleic acid transcripts [A Level teaches us that transcription is when DNA is copied into RNA by the enzyme polymerase] to detect micro genetic mutations.

The technology of three-parent families is that the pronucleus of an oocyte (cell which divides by meiosis to form an ovum) from the woman with mitochondrial disease is transferred into a healthy donor cell. Both the mother’s and donor’s oocytes are fertilised by the spermatozoon (motile sperm cell) before the pronucleus is removed from the mother’s oocyte. The pronucleus is removed before the oocytes divide into an embryo. The nucleus contains the majority of genetic content so this will be passed onto the offspring along with normal, healthy mtDNA (the offspring genome is made up of 0.2% mitochondrial DNA). This donor cell with the mother’s nucleus can now divide by mitosis into an embryo. This process of moving the pronucleus from cell to cell is called ‘pronuclear transfer’.

Women need this new technology if they have a mitochondrial disease. Due to the mitochondria being such an important organelle, with the role of synthesising ATP, many organs are affected if the organelle is diseased. Heteroplasmy is when mitochondrial DNA is made up of two types, wild-type and mutant. The severity of symptoms depends on the proportion of mutant mitochondrial DNA per cell. Some problems caused by having mitochondrial disease are blindness, deafness, muscle disease, heart disease, respiratory failure, liver failure and diabetes.

Foetuses are tested by genetic analysis within the first three months (trimester) by examining amniotic fluid or chorionic villus sampling (CVS), or before implanting of an embryo made by in vitro fertilisation called pre-implantation genetic diagnosis, if there is a chance that they may have a genetic disorder.

Emily Buchanan