Using human tissue cultures as an alternative to using protected animals in research.

Introduction

Animals have been used in biomedical and bioscientific research for over one hundred years (AMP, 2020). To scientists, animals are good models for systems representing the human body and human disease, and therefore, this in vivo method of testing is, and has been for many decades, widely used across toxicological and other biomedical research. This type of research has played an essential part in the development of masses of veterinary, medical and other scientific discoveries and breakthroughs, including the production of a variety of medical treatments and vaccinations (Kaushik and Vaswani, 2018).

Now more than ever, the use of animals in this way is an extremely controversial matter in society. While many believe that laboratory animals are mistreated and kept in poor conditions, there are government legislations in place to ensure that this is not the case. The most prevalent legislation effective in the protection of laboratory animals currently is the Animals (Scientific Procedures) Act, 1986 – otherwise known as ASPA. This legislation was put in place to regulate all procedures that are carried out on protected animals. A protected animal is classed as any living vertebrae, other than humans, or any living cephalopod (Government Legislation UK, 2020). Vertebrates such as birds, mammals and reptiles are protected once they have reached two thirds of their gestation periods, while in any other case, the animal is protected once it has reached the stage where it becomes capable of feeding independently. Cephalopods are not protected if they are in their embryonic form. A procedure is classed as regulated if it may have any effect of pain, suffering, distress or lasting harm equivalent to, or higher than, that caused by the introduction of a needle in accordance with good veterinary practice, and these must only be carried out if they serve an educational or scientific purpose (Home Office, 2014). The class of regulated procedures also encompasses breeding programmes in which the animals bred are genetically modified. These procedures are regulated by the Home Office and the Department of Health, Social Security and Public Safety across the UK – they make sure that any establishment and persons carrying out regulated procedures on protected animals have the correct licensing to do so.

ASPA ensures that all animals that are bred, supplied and used for the purpose of scientific procedures and research are looked after in accordance with the best possible standards of animal husbandry, so that scientific researchers treat laboratory animals with the respect and compassion that they deserve and provide them with the appropriate housing and enrichment that they need, as well as seeing to their social needs. If animal husbandry is not to a good enough standard, it can have severe effects on both the physical health and welfare of the animal. The Animals (Scientific Procedures) Act protects animals used in biomedical and bioscientific research through the implementation of the principles of the 3R’s: replacement, reduction and refinement. The concept of the 3R’s was introduced by William Russel and Rex Burch in 1959, with the intention of enabling biomedical and bioscientific research to become more humane (Baumans, 2004). One of the main purposes of the 3R’s is to encourage the use of alternatives to protected animals where possible in scientific research (Rai and Kaushik, 2018).

The first of the 3R’s – replacement – involves replacing protected animals used in scientific research either with non-protected animals (partial replacement), or replacing them with a source other than an animal (absolute replacement) (Parker and Browne, 2014). Examples of partial replacement could include using non-protected animals such as fruit-flies or worms, while examples of absolute replacement could include the use of human tissue cell cultures or computer models (Schechtman, 2002). Reduction simply encourages that where possible, if protected animals are absolutely necessary for a science research project, then the minimum number of animals possible should be used, without it having a negative impact and compromising the objectives of the study (Clark, 2017). What this means is that the population sample of protected animals used must be as little as possible, whilst still being of an appropriate size for the results of the study to be valid and representative of a wider population. The final of the 3R’s is refinement. Refinement is about minimizing the pain, suffering, stress or lasting harm that the animal experiences, in order to be able to maximize their wellbeing (Faisal, 20005). Where animals must be used, techniques such as administering analgesics and sedatives could be used to minimise the pain experienced by the animal. Refinement also involves providing the animals with the correct enrichment and only using them a minimal number of times to obtain results for the study, in order to make their day-to-day lives as stress free and pain free as possible.

One constantly growing and developing example of an alternative method to using animals in research involves the use of human cells and tissue cultures. This is an in vitro method that requires scientists to grow cultured human tissue cells in a suitable growth medium outside of the body, to form tiny structures that function like human organs such as the heart, lungs, liver and kidneys (Amelian et al, 2017). This review will analyse the efficacy of human tissue culturing as an alternative method to using protected animals in biomedical and bioscientific research.

 

In vitro tissue models: Human tissue cultures in biomedical and bioscientific research

Clinical studies can take years to be completed and cost millions or even billions of pounds, all while animals are being subjected to harm and stress, and many lose their lives. Using human tissues can be a particularly effective method in the biomedical industry when it comes to developing and testing the effects of new treatments and drugs, and it does not require the use of any protected or non-protected animals. Not only does it eliminate the controversial issue of using laboratory animals in biomedical and bioscientific research, but it also provides more human-relevant results during medicine and vaccination production than animal experiments do (Polini et al, 2014).

When an animal is used in a science laboratory for research purposes, it has to have first been obtained from purpose breeders. Transportation of the animals to the required establishment can take anything from a couple of hours to several days, which in itself can severely stress the animals (Ashenafi, 2018). Once they arrive in the laboratories and are placed in their new environments, they have to be left to settle for seven days before any research can be carried out. This is so that the animals can adapt to their new surroundings without it having an effect on their behaviour, which could impact the experimental results. Common laboratory animals that are used for scientific research include mice and rats. Guinea pigs and rabbits are also sometimes used along with some species of primate. Most animals are only used to collect data over a period of several days or weeks. However, due to primates having a much longer life span, they are often used for long-term studies which can take several years (Knight, 2008). In most cases, after laboratory animals have fulfilled their purpose in the research, they are humanely killed. Using human tissue cell cultures saves this entire process that a protected animal would face in its lifetime.

As well as this method of research being beneficial in the sense that no animals have to be put through any pain, suffering or distress, human tissue culturing techniques can be much less time consuming and cheaper to run (Doke and Dhawale, 2015). Almost all drugs, chemicals and cosmetics are now tested for their efficacy and toxicity using human tissue cell cultures as opposed to protected animals. For example, in the year 2000, Ke-Ping Xu et al undertook a study which looked at eye irritancy. Previous to this study, chemical irritancy was analysed by a method called the Draize Test, which was carried out on animals – particularly on rabbits – and caused them a great level of pain and discomfort (Yun et al, 2016). However, Ke-Ping Xu and his team of researchers instead used organ tissue cultures, which saw a cornea cultured for three weeks before it was then analysed to look for the effects of the chemical irritancy. This way no animals were harmed in the process of the research.

One of the current top ten emerging human tissue culturing tools developed to aid in drug discovery programmes is a method called “Organs-on-a-chip” (Wu et al, 2020). While many clinical trials on animals often fail to predict accurate human responses to the treatments, due to the lack of ability of the animal models to accurately mimic human pathophysiology, organs-on-a-chip studies are an alternative way to accelerate the progression of drug development for humans (Selimovic et al, 2013). The cultures are grown on scaffolds embedded on plastic chips, and the growth of the organs enable modelling of human physiology and disease. These biomimetic organ systems have the ability to regulate key parameters found in human organs, such as maintaining concentration gradients, cell patterning, interactions between tissues and organs, and so on (Zhang et al, 2018). This form of microengineering enables definite control over the cellular microenvironment, therefore resulting in more representative microsystems for the true in vitro environment (Wikswo et al, 2013).

Furthermore, the organs-on-a-chip research method can replace the use of whole live animals in early research stages, when only certain systems need to be tested on. Each organ chip consists of a small, clear, flexible polymer, which contains hollow microfluidic channels that are lined by living human organ-specific cells. These cells are connected with human endothelial cell-lined artificial vasculature, and when mechanical forces are applied, this can mimic the physical microenvironment of true living organs in humans (Ronaldson-Bouchard and Vunjak-Novakovic, 2018). This can include mimicking functions such as peristalsis-like deformations in the intestine, as well as respiratory motions in the lungs. Their ability to be able to host and combine different cell and tissue types to form human organs, means that organ chips are ideal microenvironments for studying molecular-scale activities in organ functions, as well as mimicking human-specific disease states and enabling researchers to identify new therapeutic targets in vitro. Additionally, the fact that they can recreate therapeutically relevant connections, such as the blood-brain-barrier, means that it is possible for scientists to be able to more easily investigate drug delivery and effects (Takebe et al, 2017).

Organ-on-a-chip technology gives scientists the ability to be able to reproduce physiological functions of in vivobody tissue, with much more accuracy than if they did so with the standard cell-based model systems (Sung, 2018). The fact that the organ-on-a-chip technology consists of different micro channels and allows for the formation of sub-compartments, means that it provides the advantages of scientists being able to manipulate the communication between different tissue types, as well as allowing them control the physical conditions so precisely (Ingber, 2018). Considering the fact that drug trials using animals often fail, due to the animal models not being particularly predictive of the human condition, and the fact that they are much more expensive and time-consuming, organ-on-a-chip cultures will be able to provide a better alternative platform for drug and toxicology testing, whilst only requiring micro-sale quantities of cell and drug samples (Sosa-Hernandez et al, 2018).

Although organ-on-a-chip systems represent many aspects of real body tissues, many tissue functions are not represented, which can cause certain limitations. This concept is specifically predominant in the organ-on-a-chip recreation of the hepatic system. The liver is responsible for an abundancy of toxicology mechanisms, including interactions with circulating immune cells to pathogenesis of liver fibrosis. The sinusoidal tissue unit responsible for this is not fully established in organ-on-a-chip cell cultures, which could mean that not all toxicological effects of drug treatments trialled on the liver in this way  are effectively displayed (Reif, 2014). As well as this, alveoli (the structures responsible for regulating gas exchange in the lungs) can be extremely challenging to produce in vitro. Although this is the case, a team of scientists led by Dongeun Huh, in 2012, created a lung-on-chip model which used soft lithography to separate the chip into several regions, which were partitioned by membranes with an extracellular matrix. The upper regions contained alveolar epithelial cells, while the lower regions had human microvascular endothelial cells, which enabled the organ-a-chip model to mimic the alveolar-capillary barrier.  This highlights that although organ-on-a-chip technologies are an extremely enhanced development as an alternative to using animals in the biomedical and bioscientific research field, further developments still need to be made for them to act as a completely accurate  representation of an organ’s entire function.

In addition, the process of actually obtaining human tissue cell samples for the purpose of research has to follow several government legislations. The Human Tissue Act 2004 regulates the use of tissue donated by either deceased or living organ donors. A deceased donor must have given full consent to the removal of their organs for the sole purpose of scientific research, prior to their death (Government Legislation UK, 2020). Living donors must also give their full consent and a government ethics committee must review it before any research can be carried out.

 

Conclusion

Biomedical and bioscientific research involving animals will always remain a crucial part of scientific developments, particularly in the medical health field. Although human cell cultures are an extremely effective in vitro method that avoid the use of protected animals, and the use of this method in the development of different drugs and vaccinations will continue to increase over the coming years, it will never completely eliminate the use of laboratory animals in research, even in combination with other alternatives. An overall faster turnaround of analysis via the means of organ-on-a-chip technology could lead to a reduction in the cost of drug trials, and the use of human cells produce greater precision. However, even in times like the current, with all of the rapid progression of advances in technology, using animals in biomedical research will remain a vital component of scientific discoveries, with beneficial results for both animals and humans, for the foreseeable future.

 

Bibliography

Amelian, A., Wasilewska, K., Megias, D. and Winnicka, K. (2017) Application of standard cell cultures and 3D in vitro tissue models as an effective tool in drug design and development. Pharmacological Reports. 69(5). Pp 861-870.

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Ashenafi, D. (2018) The Effect of Long Distance Transportation Stress on Cattle: A Review. Biomedical Journal of Scientific and Technical Research.

Baumans, V. (2004) Use of animals in experimental research: an ethical dilemma? Gene Therapy.

Clark, J. M. (2017) The 3Rs in research: a contemporary approach to replacement, reduction and refinement. British Journal of Nutrition. Vol 120.

Doke, S. K. and Dhawale, S. C. (2015) Alternatives to animal testing: A review. Saudi Pharmaceutical Journal. 23(3). Pp 223-229.

Faisal, G. (2005) Introduction to the 3Rs (Refinement, Reduction and Replacement). Journal of the American Association for Laboratory Animal Science. 44(2). Pp 58-59.

Home Office (2014) Chapter 1: Background to the Animals (Scientific Procedures) Act 1986. Guidance on the Operation of the Animals (Scientific Procedures) Act 1986. Pp 10-11.

Huh, D., Leslie, D. C., Matthews, B. D., Fraser, J. P., Jurek, S., Hamilton, G. A., Thorneloe, K. S., McAlexander, M. A. and Ingber, D. E. (2012) Human Disease Model of Drug Toxicity-Induced Pulmonary Edema in a Lung-on-a-Chip Microdevice. Science Translational Medicine. 4(159). Pp 147-159.

Ingber, D. E. (2018) Developmentally inspired human ‘organs on chips’. The Company of Biologists. Vol 145.

Kaushik, K. and Vaswani, R. (2018) Research on animas and current UGC guidelines on animal dissection and experimentation: A critical analysis. Bioethics Update. 4(2). Pp 119-139.

Knight, A. (2008) The beginning of the end of for chimpanzee experiments?  Philosophy, Ethics, and Humanities in Medicine. 3(16).

Legislation.gov.uk (2020) Animals (Scientific Procedures) Act 1986. [online]. http://www.legislation.gov.uk/ukpga/1986/14/section/1 (Accessed on 17th February, 2020).

Legislation.gov.uk (2020) Human Tissue Act 2004. [online]. https://www.legislation.gov.uk/ukpga/2004/30/contents (Accessed 29th March, 2020).

Parker, R. M. A. and Browne, W. J. (2014) The Place of Experimental Design and Statistics in the 3Rs. ILAR Journal. 55(3).

Polini, A., Prodanov, L., Bhise, N. S., Manoharan, V., Dokmeci, M. R. and Khademhosseini, A. (2014) Organs-on-a-chip: a new tool for drug discovery. Expert Opinion on Drug Discovery. 9(4). Pp 335-352.

Rai, J. and Kaushik, K. (2018) Reduction of Animal Sacrifice in Biomedical Science & Research through Alternative Design of Animal Experiments. Saudi Pharmaceutical Journal. 36(6). Pp 896-902.

Reif, R. (2014) The body-on-a-chip concept: possibilities and limitations. Journal of Experimental and Clinical Sciences. Vol 13. Pp 1283-1285.

Ronaldson-Bouchard, K. and Vunjak-Novakovic, G. (2018) Organs-on-a-Chip: A Fast Track for Engineered Human Tissues in Drug Development. Cell Stem Cell. 22(3). Pp 310-324.

Schechtman, L. M. (2002) Implementation of the 3Rs (Refinement, Reduction, and Replacement): Validation and Regulatory Acceptance Considerations for Alternative Toxicological Test Methods. ILAR Journal. 43(1). Pp 85-94.

Selimovic, S., Dokmeci, M. R. and Khademhosseini, A. (2013) Organs-on-a-chip for drug discovery. Current Opinion in Pharmacology. 13(5). Pp 829-833.

Sosa-Hernandez, J. E., Villalba-Rodriguez, A. M., Romero-Castillo, K. D., Aguilar-Aguila-Isaias, M. A., Garcia-Reyes, I. E., Hernandez-Antonio, A., Ahmed, I., Sharma, A., Parra-Saldivar, R. and Iqbal, H. M. N. (2018) Organs-on-a-Chip Module: A Review from the Development and Applications Perspective. Micromachines. 9(10).

Sung, J. H. (2018) Chapter 10 – Pharmacokinetic-based multi-organ chip for recapitulating organ interactions. Methods in Cell Biology. Vol 146. Pp 183-197.

Takebe, T., Zhang, B. and Radisic, M. (2017) Synergistic Engineering: Organoids Meet Organs-on-a-Chip. Cell Stem Cell. 21(3). Pp 297-300.

Wikswo, J. P., Curtis, E. L., Eagleton, Z. E., Evans, B. C., Kole, A., Hofmeister, L. H. and Matloff, W. J. (2013) Scaling and systems biology for integrating multiple organs-on-a-chip. Royal Society of Chemistry. Vol 13. Pp 3496-3511.

Wu, Q., Liu, J., Wang, X., Feng, L., Wu, J., Zhu, X., Wen, W. and Gong, X. (2020) Organ-on-a-chip: recent breakthroughs and future prospects. Biomedical Engineering Online. 19(9).

Xu, K., Li, X., and Yu, F. X. (2000) Corneal Organ Culture Model for Assessing Epithelial Responses to Surfactants. Toxicological Sciences. 58(2). Pp 306-314.

Yun, J., Hailian, Q., Na, Y., Kang, B., Yoon, J., Cho, E., Lee, M., Kim, D., Bae, S., Seok, S. H. and Lim, K. (2016) Exploration and comparison of in vitro eye irritation tests with the ISO standard in vivo rabbit test for evaluation of the ocular irritancy of contact lenses. Toxicology in Vitro. Vol 37. Pp 79-87.

Zhang, B., Korolj, A., Lai, B. F. L. and Radisic, M. (2018) Advances in organ-on-a-chip engineering. Nature Reviews Materials. Vol 3. Pp 257-278.

Reflective Practice as Evidence for Decision Making

Particularly in medical professions, evidence based practice and reflective thinking are two of the most important professional skills required when making decisions. Without reflective thinking, it would be almost impossible to be able to learn from mistakes and improve on professional decision making. Decision making is vital in clinical practice because the outcome can have a huge, or even life-changing impact on a patient’s life.

 

Evidence based practice (EBP) can be described as the use of current, valid and best available evidence alongside a high level of expertise in order to be able to make informed decisions regarding patients in the health care field (Titler, 2008). Within the subject of evidence based practice, it is important to consider what evidence is and the variety of different sources that can be used.

Figure 1: Evidence Based Practice Model (Shlonsky and Gibbs, 2004).

 

In simple terms, evidence is a form of material that can be used to prove whether something is true or not true (Cambridge Dictionary, 2019). As shown in figure 1, evidence can be subdivided into 3 different sections: clinical expertise, best research evidence and patient/owner opinions and preferences (Toon, 2014). Particularly in the case of veterinary and medical occupations, a combination of these three factors are used to determine the most accurate diagnosis and the best course of action for a patient. Whether a professional practitioner undertakes evidence based practice effectively or not, all depends on whether they use the right sources of evidence that are available to them. For example, the use of scientific based evidence in research papers and peer-reviewed articles are much more reliable than if a professional was to base their clinical decision purely on anecdotal evidence, or the personal opinion of one veterinary surgeon that they may have spoken to.

Figure 2: The traditional hierarchy of evidence based medicine (QUT Library, 2019).

 

The pyramid in figure 2 shows which sources of evidence are of best quality, in order from the best at the top, down to the least reliable at the bottom. The best evidence based practice would use the best sources of evidence.

 

Alongside evidence based practice comes reflective practice. Reflective practice is a method used to study and analyse your own experiences in order to be able to improve how you work in the future (Koshy et al, 2017). The idea of it is to be able to identify where certain decisions that you have made may have led to things either being a success or going wrong. Most importantly, reflective practice is being able to learn from the experience.

Examples of what reflective practice could be used to reflect on in the field of veterinary medicine include things as simple as a dissatisfied patient, to things more serious like post-operative complications, a missed diagnosis or even a failed procedure. These examples are all things that could go wrong, and reflecting on these involves working out whether there is anything that might have been done differently to prevent it from happening again in the future.

Although most reflective practice is centred around errors, it is also extremely important for professionals to use it to look back on things that have been successful. For example, veterinary surgeons use reflective practice to look back on things like ‘thank you’ letters from clients, successful revivals from a cardiac arrest, an extremely hard procedure which has been performed well, and so forth. This is hugely important in confidence building and providing a rewarding feeling, which encourages surgeons to be able to do the same thing again the next time.

 

There are several important steps to reflective practice, which are well displayed and described by the reflective learning cycle produced by Gibbs in figure 3 (see below).

Figure 3: The stages of Gibbs’ Reflective Learning Cycle (University of Sheffield, 2019).

 

This cycle is used by many practitioners to help them reflect on their experiences at work and learn from them so that they can use it to help them constantly excel and improve in the workplace.
As quoted by Jill Macdonald, (a qualified veterinary nurse): “Reflective practice is one of the fundamental aspects of being a professional”. Reflective practice comes with the benefits of retaining and consolidating information, using what you have learned and applying it to everyday work practice, as well as sharing it with others to help them learn too.

 

A specific example of where reflective practice may be used as evidence for decision making could be when considering the best choice for an old dog who has been seriously injured after being hit by a car. A veterinary surgeon may decide that a leg amputation is the best option for the dog at that time. However, on reflection, it may have been more beneficial to explore other options such as a more minor surgery, or for the dog to have been euthanised, due to its age and the suffering. When looking back on this in future cases, the vet can use it as evidence to help them make different decisions in other similar incidents.

 

When comparing the two, both evidence based practice and reflective practice are vital thinking skills necessary to be able to analyse critical clinical decisions (Fontaine, 2018).  It is important that veterinarians are able to make good clinical decisions using evidence based practice as well as then being able to use reflective practice to analyse the decision that they have made. This therefore enables them to keep improving the way that they practice and make decisions in future cases.

Overall, it is clear that evidence based practice and reflective practice both work with each other hand-in-hand to produce the best decision making in professions. Together they enhance professionalism and encourage self-directed learning.

 

 

Bibliography:

 

Cambridge Dictionary (2019) Evidence. [online]. https://dictionary.cambridge.org/dictionary/english/evidence(Accessed on 18th November 2019).

 

Fontaine, S. J. (2018) The role of reflective practice in professional development. UK-VET The Veterinary Nurse.

 

Koshy, K., Limb, C., Gundogan, B., Whitehurst, K. and Jafree, D. J. (2017) Reflective practice in health care and how to reflect effectively. International Journal of Surgery. Oncology. 2(6).

 

Macdonald, J. (2018) Learning from reflection. RCVS.

 

QUT Library (2019) Evidence explained. [online]. https://www.library.qut.edu.au/search/getstarted/howtofind/evidencebased/evidenceexplained.jsp (Accessed on 30th November 2019).

 

Shlonsky, A. and Gibbs, L. (2004) Will the Real Evidence-Based Practice Please Stand Up? Teaching the Process of Evidence-Based Practice to the Helping Professions.

 

Titler, M. G. (2008) Chapter 7: The Evidence for Evidence-Based Practice Implemention. Patient Safety and Quality: An Evidence-Based Handbook for Nurses.

 

Toon, P. (2014) What is evidence? London Journal of Primary Care. 6(5). Pp 95-97.

 

University of Sheffiled (2019) Reflective Practice. [online]. https://www.sheffield.ac.uk/ssid/301/study-skills/university-study/reflective-practice (Accessed 30th November 2019).

 

Professional Practice in Bioveterinary Science – Task D

A reflection on the result of a research skills test

 

After reflecting on the process of my learning and skills development across the Sector Studies module, and especially looking at the feedback I have received from the exam, I am overall very happy with what I have achieved and feel confident that I have a good and strong understanding of the topics that have been covered.

 

In the research skills test, I achieved a mark of 78%, which was an improvement from the mock exam we did in class in which I achieved 70%. Upon looking at this score and even at the slight improvement across the small period between the mock and the real exam, I can confidently say that my knowledge on research methods, mathematical and statistical skills, as well as my ability to use a scientific calculator, have all hugely developed and are at the required level that they should be in order to be a successful bioveterinary scientist.

 

Going into the exam, although I had achieved a first class mark in my mock, I lacked confidence as I know from previous exams in other modules, and from sitting GCSE and A-level exams, that when under pressure and trying to work to a time limit, I often make silly mistakes, particularly when it comes to mathematical calculations. I also know that regardless of how many times I double check answers, I usually fail to identify anything that I have done wrong, and therefore when I go over them, I tend to make the same mistakes each time – this was one of the main problems that I faced in my statistics module of A-level mathematics. Making silly mistakes under pressure and not being able to identify and rectify them is common for anyone, and it is difficult to be able to prevent it (Eisold, 2011). However, feedback from the sector studies exam showed that I hardly lost any marks on the mathematics questions at all. On reflection, mathematics has been a consistently strong area of mine throughout this first year of my degree, as I also achieved well in the maths areas of both our Fundamentals in Bioveterinary Science module and in Essential Laboratory Techniques.

 

One of the other factors that unnerved me about the exam was the possibility of a Chi-squared test question featuring in the paper, as this was one of my weaknesses at A-Level biology. Having said this, in both the lecture covering this material and the exam question, I was comfortable with it and knew how to do it with no problem. Despite my doubts, my ability to complete this question correctly could have been from my prior knowledge on the topic, whether I had been successful with it at A-Level or not. Studies have proved that students tend to achieve higher marks in areas which they already have prior-knowledge in (Cogliano et al, 2019). All I needed was a re-cap on the subject to enhance my understanding of it. My prior knowledge from A-Level biology and chemistry has also been a great help for me over the last year, particularly in the fundamentals, molecular biology and biochemistry modules. Due to knowing the basics of these I have been able to build on that knowledge and expand and develop it into much deeper and wider details, which has helped me to improve quickly over this last year and will be very beneficial for the duration of this course, as well as any further degrees or jobs that I may have in the animal health industry in the future.

 

Furthermore, a method of teaching that helped me a lot with the sector studies exam were the starter activities given in each lecture. These were really useful, as the constant repetition of practicing the basic calculator questions made me able to answer them increasingly quickly and with ease. The method of repetition was clearly of a huge benefit to my learning, and this can be explained by the fact that repetition induces neural enhancement (Hashimoto et al, 2011). As well as this, although we were given a step by step calculator sheet explaining how to perform each of these calculations, the constant repetition of doing this in the starter activities meant that it came very naturally and I had no need to use the sheet at all. This was beneficial because it saved me a lot of time in the exam.

 

My main downfall in the exam was the general research practice questions. These included questions on journals and databases, along with limitations to research. I think my main reason for losing marks in this area was because the rest of my co-hort and I joined in on the sector studies classes slightly later than the animal science students, and as a result we missed any content identifying that journals and databases were topics we needed to know for the exam. When I saw these questions in the exam, I completely panicked and I left most of them blank. However, on reflection, I should have stayed calm and tried to recall any journals and databases that I have used for previous assignments across other modules covered this year and written those down as examples.

 

Overall, I am extremely happy with how Sector Studies has helped me to develop my statistical skills and improve my knowledge on research methods. I am confident when I say that this, along with my progress in all other modules across this year, has prepared me well for future tasks requiring these skills both on this degree, and in the animal health industry when working as a professional bioveterinary scientist.

 

 

 

 

 

 

 

 

References:

 

Cogliano, M., Kardash, C.M. and Bernacki, M.L. (2019) The effects of retrieval practice and prior topic knowledge on test performance and confidence judgements. Contemporary Educational Psychology. Vol. 56. Pp. 117-129.

 

Eisold, K. (2011) Making stupid Mistakes. Psychology Today.

 

Hashimoto, T., Usui, N., Taira, M. and Kojima, S. (2011) Neural enhancement and attenuation induced by repetitive recall. Neurobiology of Learning and Memory. 96(2). Pp. 143-149.

 

 

Failures in meiosis, which could result in chromosomal disease

Although the ability of an individual organism to reproduce is not essential to its survival, reproduction between different organisms is vital for the continuation of life on earth. In order for animals to be able to reproduce, they need working sexual reproductive organs which can produce gametes (ovum in females and spermatids in males) – these gametes are produced by a process called meiosis (Stauffer et al, 2018).

 

Meiosis is one of two types of cell division. The other type of cell division found in organisms is called mitosis, and it is the process by which a single cell divides, producing two genetically identical daughter cells. The main purpose of mitosis is for tissue growth and also to replace dead or worn out cells (Live Science, 2018). Mitosis is one of the phases of the cell cycle and it consists of five different stages. The first stage is prophase, followed by prometaphase, metaphase, anaphase and then telophase (Nature.com, 2019). There is also a further stage called cytokinesis, which begins towards the end of telophase .

 

Unlike mitosis, which consists of one division, meiosis involves two complex cellular divisions (Alberts et al, 2002). The first stage, (Meiosis 1), is made up of 4 stages: prophase 1 (which itself consist of five sub-phases), metaphase 1, anaphase 1 and telophase 1. Meiosis 1 is all to do with the separation of homologous chromosomes and the duplication of DNA. As well as this, the process of DNA shuffling allows genetic variation in species.

The five sub-phases of prophase 1 include leptotene, zygotene (where crossing over is initiated), pachytene, diplotene (where crossing over is completed) and finally diakinesis. Throughout these stages, the chromosomes condense and the nuclear membrane of the cell dissolves, which makes the chromosomes become gradually visible. The homologous chromosomes pair up and become bivalent, aligning with each other gene by gene. Recombination occurs and the non-sister chromatids exchange genes at corresponding segments of DNA – this produces recombinant DNA.
In metaphase 1, bivalent chromosomes line up on the metaphase plate, facing the opposite poles of the cell. Microtubules from opposing poles of the spindle fibres attach to each individual pair of homologous chromosomes. This is also the stage where independent assortment occurs (Chinnici et al, 2004). Independent assortment is where the chromosomes move around randomly to separate / opposing poles, which will eventually  result in a variety of combinations of chromosomes in each gamete. This, combined with crossing over, is what causes genetic variation.
Anaphase 1 consists of the separation of the homologous chromosomes. The kinetochores retract, which pulls the chromosomes apart to the opposite poles. During this process, the sister chromatids remain associated at the centromere, which in turn results in their movement as one single unit towards the same pole that the spindle fibre is attached to.

In the final stage of meiosis 1 (telophase 1), each half of the cell now has a complete haploid set of chromosomes which have been duplicated. The nuclear membrane reforms and surrounds the two daughter nuclei that now exist. Finally, the chromosomes become less condensed.

At the same time as telophase 1 occurs, the cell is also undergoing cytokinesis. This is the process which produces the end products of meiosis 1 – two unidentical daughter cells with a complete set of chromosomes (46 chromosomes each).

 

The second stage of meiosis is called meiosis 2, and this is almost made up of the same stages as the first meiotic division. The stages are: prophase 2, metaphase 2, anaphase 2, telophase 2 and cytokinesis. Meiosis 2 resembles almost the exact same process as a normal mitotic division, apart from the fact that there is no chromosome division – instead of the separation of homologous chromosomes it is about the separation of the sister chromatids. Meiosis 2 begins with prophase 2 which starts immediately after interkinesis (the phase between meiosis 1 and meiosis 2). In prophase 2, the nuclear membrane dissolves again and the chromosomes become compact like in prophase 1. The main difference is that a spindle apparatus forms and each chromosome remains as a composition of two sister chromatids attached at the centromere.

The next stage of meiosis 2 is metaphase 2, which is where the chromosomes line up at the equator and microtubules from opposing poles of the spindle attach to the kinetochores of the sister chromatids. This stage is followed by anaphase 2, which is where the centromeres split, resulting in the separation of the sister chromatids. These then move to opposite poles of the cell.

Telophase 2 is where the nuclear membrane and nucleolus reappear, forming 4 haploid nuclei. These are then cleaved apart to form a tetrad of cells in cytokinesis, which produces the end result of meiosis: 4 non-identical haploid daughter cells (gametes), each cell containing 23 chromosomes. In a male, one meiotic division produces four spermatozoa cells, whereas in a female, meiosis produces one ovum and three polar bodies.

 

The gametes produced by meiosis (ovum and sperm cells), combine to make a zygote during sexual reproduction. The halving of the number of chromosomes in the gametes during meiosis ensures that the zygotes have the same number of chromosomes from each generation to the next. However, meiosis does not always produce the right results. In some cases, there can be failures at any stage in the meiotic divisions which can in turn lead to the offspring having a chromosomal disease. Chromosomal disorders or abnormalities can be caused by the deletion, duplication or alteration of either an entire chromosome or a large part of one. Any changes to the volume of chromosomal material, whether it be an increase or a decrease, can interfere with the normal development and function of an organism. Although each different type of failure in meiosis on individual chromosomes causes a specific set of physical symptoms, the severity of the condition can vary.

 

A well known example of a chromosomal disease caused by failures in meiosis is Edward’s Syndrome (Trisomy 18). This disorder is caused by the presence of all, or part of, a third copy of the 18thchromosome. Trisomy 18 is the second most common autosomal trisomy in newborn children. The vast majority of those who suffer from Edward’s Syndrome have it as a result of maternal nondisjunction of chromosome 18 (Gaw & Platt, 2018). This means that either the homologous chromosomes fail to separate during the anaphase 1 stage of meiosis, or the sister chromatids fail to separate during the anaphase 2 stage of meiosis. Half of all babies born with Edward’ Syndrome die within less than one week of birth, and between 5% and 10% of these babies live for no longer than one year (Perlstein, n.d.).

 

Another example of a chromosomal disease caused by failures in meiosis is Wolf-Hirschhorn Syndrome (WHS), or 4p deletion syndrome. This disorder is caused by partial deletion of genetic material near to the end of the short arm of chromosome 4. Wolf-Hirschhorn Syndrome was the very first example of a human chromosomal deletion syndrome, however it is extremely rare in comparison with other chromosomal diseases (Lee & Van Den Veyver, 2018). Some symptoms of WHS include serious prenatal growth restriction, severe seizures and predominant or deformed facial features. Like Trisomy 18, 4p deletion syndrome can be diagnosed through a series of ultrasound findings, and its diagnosis is confirmed by certain genetic testing.

 

Overall, meiosis is the fundamental process in providing genetic variation, as well as ensuring that generations carry the same number of chromosomes between generations. This is critical for stable sexual reproduction through successive generations. Without meiosis occurring, no organism would be fertile and therefore there would be no continuation of life on earth. Not only is the process of meiosis vital in ensuring that there is a continuation of life, but also if there is even one tiny failure at any given point during the meiotic divisions, it can have a significant impact on the life of the offspring inheriting that gene.

 

 

 

 

 

References:

 

Alberts, B.,  Johnson, A., Lewis, J. et al. (2002) Meiosis. Molecular biology of the cell. 4thedition.

 

Chinnici, J.P., Yue, J.W., Torres, K.M. (2004) Students as “Human Chromosomes” in Role-Playing Mitosis & Meiosis. The American Biology Teacher. 66(1), pp. 35-39.

 

Gaw, S.L. & Platt, L.D. (2018) 150 – Trisomy 18.  Obstetric Imaging: Fetal Diagnosis and Care. 2ndedition. Pp. 605-608.

 

Lee, W., Van Den Veyver, I.B. (2018) 155 – Chromosome 4p Deletion Syndrome (Wolf-Hirschhorn Syndrome). Obstetric Imaging: Fetal Diagnosis and Care. 2ndedition. Pp. 626-630.

 

Live Science. (2018) What is mitosis?https://www.livescience.com/52512-mitosis.html[Accessed 22ndMarch, 2019].

 

Nature.com. (2019) Mitosis.https://www.nature.com/subjects/mitosis[Accessed 22ndMarch, 2019]

 

Perlstein, D., Davis, C.P. (n.d.) Trisomy 18 (Edward’s Syndrome). MedicineNet.

 

Stauffer, S., Gardner, A., Ungu, D.A.K., Lopez-Cordoba, A., Heim, M. (2018) Meiosis. Labster Virtual Lab Experiments: Basic Biology. Springer Spektrum, pp. 27-41.

Personal and Professional Development Plan

Becoming a working professional, in any area of expertise, is an extremely difficult and task and involves high levels of competition from others trying to secure their place in the same industry. Once becoming a professional, it is then vital to be able to maintain a high level of professionalism and to continue to develop important skills. At the end of my degree I will become a professional veterinary bioscientist. In order to continue as a professional and fulfil my ambition to go onto a postgraduate veterinary medicine degree after this course, it is extremely important that I am able to and can continue to assess the skills that I need to develop to achieve this goal.

 

Identifying personal strengths is a very important part of being able to assess progress and development. Personally, something that I identify as one of my own strengths is being able to manage my time between my work life, university life, and then also my own personal and social life including my hobbies. Time management is a key aspect of success, as without managing time well, assignments and revision can be left too late and therefore any work produced at the last minute will not be done to the highest standard possible. On the contrary, spending too much time studying can also have a negative impact on the work produced, because it can become overwhelming and the brain needs time to relax and wind down in order to function properly and learn. Due to the fact that I have a part time job and play or umpire netball matches three to four times a week, I have to ensure that I work efficiently over regular short periods of time, whilst still allowing myself time to be able to relax and go out with friends. Currently I can do this very well, and so long as I am able to maintain this I should hopefully continue to succeed and achieve well in assignments and exams, as well as keeping fit and healthy and keeping stress levels to a minimum at the same time.

 

Although my general and background knowledge of the content of the course that I am studying is good, to develop further I need to ensure that I conduct my own further independent study adding to the content that we are delivered in lectures. I need to read around the subjects more in order to widen my knowledge, as it is very important to be able to fully understand what it is that I am learning, rather than just being able to memorise a set of facts. This is vital so that I am able to progress and use this knowledge in practice in the future, whether it be during my postgraduate study or after that when I begin working in the professional field.

 

Setting myself targets is crucial to my professional and personal development throughout my studies and also for my future career. Without specific targets and goals, it is difficult to be able to know what areas to improve on and what new skills to develop in order to better myself and progress professionally.

I think that one of the main targets I have set myself is to complete more CPD (continued personal development) courses online, and to ensure that I keep a log of them on the facilities available via my Royal Society of Biology membership. This not only will broaden my own skills and knowledge, but it will be beneficial to have as evidence to show that I am committed to constant new learning when applying for postgraduate courses, and further down the line when applying for a new job. A record of continuous personal development will hopefully make me stand out compared to others who are competing for the same educational and vocational places as myself.

 

Furthermore, eventhough through work experience, my current job, completion of the bronze duke of Edinburgh award and my place in one or more netball teams at a time, all display evidence that I am capable at working  well in a team, I would like to further develop my leadership skills, which are equally as important. Leadership skills and teamwork are both extremely essential skills to have for a postgraduate course, as well as for a future career in the veterinary industry. In order for me to practice and enhance my leadership skills, I will be applying for the role as captain of the university netball team from September this year, and I have also taken on the role as Vice Chairperson of the netball club that I play for in the Chelmsford District Netball League.

 

Overall, by using the targets that I have set for myself I will hopefully be able to develop both my personal and professional skills to help me reach and achieve my desired goal.

Fundamentals Task D: Critical reflection on current understanding of maths and chemistry

As mentioned in Task A, maths and chemistry are extremely important subjects to me with regards to the level of understanding that I need in them for the career path that I am choosing to follow: veterinary medicine. Over the course of the last few months studying for my Bioveterinary Science degree, maths and chemistry skills have been a constant requirement – not just in the Fundamentals of Bioveterinary Science module, but also in the Essential Laboratory Techniques module as well. Maths skills have been required for converting units, calculating amounts of substances and making solutions, while chemistry skills were needed during Fundamentals lessons when looking into aspects of biochemical energetics and organic chemistry, as well as needing an understanding of basic chemistry when carrying out laboratory practicals. As a result of using and practicing these skills, my understanding of maths and chemistry has definitely improved and is continuing to do so each day.

Although my understanding of mathematics has always been very strong, (supported by my A* mathematics GCSE, A grade further mathematics qualification, and C grade mathematics A level qualification), at the beginning of the bioveterinary science course I was struggling to apply my maths knowledge to the word problems, and my intention was to keep practicing this question style in order to enhance my ability to be able to answer them correctly and confidently. Repeating questions over and over again is a really good way of learning and retaining information (L. Zhan et al, 2018), and by using this technique myself and practicing the maths word questions repetitively, I can now confidently answer most questions regarding making solutions that are put in front of me, or I at least know what information I am looking for and where to start. Considering the fact that when I look at my Task A reflection, answering word problems and interpreting the right information to understand where to start was a significant problem for me, my ability to now do that is a huge improvement from a month or two ago.

Furthermore, unlike mathematics, I have always found understanding chemistry a huge challenge – it is not something that comes naturally to me. In task A, I explained that I believe my lower level of understanding in chemistry could have been due to my lack of interest in the subject at school, in contrast to mathematics which is something I have always enjoyed. Students being able to engage and find interest in their subjects is a major key to them achieving well in that subject and being successful (A. Rissanen, 2018). Although being interested in a subject is not something that you can necessarily learn, I have found other ways to enhance my understanding of chemistry:
Firstly, in the Task A reflective writing piece I showed an interest in a textbook called “Chemistry for the Biosciences: The essential concepts”, written by J. Crowe and T. Bradshaw (2014 edition). I took it upon myself to purchase this book and I have been reading through it and using it at home for my own personal study. This textbook was a great purchase because it contains all of the chemistry in it that I will need to know for this course, and its explanations are all very detailed yet easy for me to be able to understand.. It also has lots of clear diagrams and pictures – which for me, as a very visual learner, is really useful and has helped me get a much better understanding of the subject (A. Bourgoyne and M. Alt, 2017). I am also able to use the book to asses my understanding of the subject because it provides online services and questions for you to answer. The most helpful part of the questions is not necessarily actually answering them, but it is marking them by using the answers given at the back of the book and being able to self-assess. Being able to self-assess and review answers and see where you have gone wrong is a big part of advancing your learning  and helping you to progress forwards (P. Orsmond and S. Merry, 2013).

Also, throughout all of the biochemistry / organic chemistry lessons that we have had run by John Morgan for our Fundamentals in Bioveterinary Science module, I have been engaging and answering his questions to the class. In doing so I have actually found myself very surprised with my level of understanding of chemistry and have come to the realisation that I may have been underestimating my ability in chemistry just because I did not achieve highly in it at A level. It is possible that my good level of understanding John Morgan’s lessons have been aided by the extra reading and self-learning that I have been doing, combined with the previous knowledge I have from GCSE and A Level chemistry.

On reflection, I am extremely pleased with the improvement I have seen in my understanding of maths and chemistry to get it to the level that it is currently at now. With the help of my peers, lecturers and own resources, I am constantly building my knowledge and understanding of the subjects. Moving forward, I will continue to uphold my own private study on both mathematics and chemistry, and I will seek any advice from peers and staff around me if it is needed in order to ensure that I can continue to maintain and build on my level of understanding.

 

 

References

Bourgoyne, A. and Alt, M. (2017) The Effect of Visual Variability on the Learning of Academic Concepts. Journal of Speech, Language and Hearing research.

Orsmond, P and Merry, S. (2013) The importance of self-assessment in students’ use of tutors’ feedback: a qualitative study of high and non-high achieving biology undergraduates. Assessment & Evaluation in Higher Education.

Rissanen, A. (2018) Student Engagement in Large Classroom: The Effect on Grades, Attendance and Student Experiences in an Undergraduate Biology Course. Canadian Journal of Science, Mathematics and Technology Education.

Zhan, L. et al. (2018) Effects of Repetition Learning on Associative Recognition Over Time: Role of the Hippocampus and Prefrontal Cortex. Frontiers in Human Neuroscience.