\documentclass[10pt,a4paper]{article} % Packages \usepackage{fancyhdr} % For header and footer \usepackage{multicol} % Allows multicols in tables \usepackage{tabularx} % Intelligent column widths \usepackage{tabulary} % Used in header and footer \usepackage{hhline} % Border under tables \usepackage{graphicx} % For images \usepackage{xcolor} % For hex colours %\usepackage[utf8x]{inputenc} % For unicode character support \usepackage[T1]{fontenc} % Without this we get weird character replacements \usepackage{colortbl} % For coloured tables \usepackage{setspace} % For line height \usepackage{lastpage} % Needed for total page number \usepackage{seqsplit} % Splits long words. %\usepackage{opensans} % Can't make this work so far. Shame. Would be lovely. \usepackage[normalem]{ulem} % For underlining links % Most of the following are not required for the majority % of cheat sheets but are needed for some symbol support. \usepackage{amsmath} % Symbols \usepackage{MnSymbol} % Symbols \usepackage{wasysym} % Symbols %\usepackage[english,german,french,spanish,italian]{babel} % Languages % Document Info \author{Molly} \pdfinfo{ /Title (3-3-cells-and-radiation.pdf) /Creator (Cheatography) /Author (Molly) /Subject (3.3 Cells and Radiation Cheat Sheet) } % Lengths and widths \addtolength{\textwidth}{6cm} \addtolength{\textheight}{-1cm} \addtolength{\hoffset}{-3cm} \addtolength{\voffset}{-2cm} \setlength{\tabcolsep}{0.2cm} % Space between columns \setlength{\headsep}{-12pt} % Reduce space between header and content \setlength{\headheight}{85pt} % If less, LaTeX automatically increases it \renewcommand{\footrulewidth}{0pt} % Remove footer line \renewcommand{\headrulewidth}{0pt} % Remove header line \renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit % This two commands together give roughly % the right line height in the tables \renewcommand{\arraystretch}{1.3} \onehalfspacing % Commands \newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour \newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols \newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns \newcommand{\tn}{\tabularnewline} % Required as custom column type in use % Font and Colours \definecolor{HeadBackground}{HTML}{333333} \definecolor{FootBackground}{HTML}{666666} \definecolor{TextColor}{HTML}{333333} \definecolor{DarkBackground}{HTML}{A3A3A3} \definecolor{LightBackground}{HTML}{F3F3F3} \renewcommand{\familydefault}{\sfdefault} \color{TextColor} % Header and Footer \pagestyle{fancy} \fancyhead{} % Set header to blank \fancyfoot{} % Set footer to blank \fancyhead[L]{ \noindent \begin{multicols}{3} \begin{tabulary}{5.8cm}{C} \SetRowColor{DarkBackground} \vspace{-7pt} {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}} } \end{tabulary} \columnbreak \begin{tabulary}{11cm}{L} \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{3.3 Cells and Radiation Cheat Sheet}}}} \\ \normalsize{by \textcolor{DarkBackground}{Molly} via \textcolor{DarkBackground}{\uline{cheatography.com/30516/cs/9541/}}} \end{tabulary} \end{multicols}} \fancyfoot[L]{ \footnotesize \noindent \begin{multicols}{3} \begin{tabulary}{5.8cm}{LL} \SetRowColor{FootBackground} \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}} \\ \vspace{-2pt}Molly \\ \uline{cheatography.com/molly} \\ \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}} \\ \vspace{-2pt}Not Yet Published.\\ Updated 20th October, 2016.\\ Page {\thepage} of \pageref{LastPage}. \end{tabulary} \vfill \columnbreak \begin{tabulary}{5.8cm}{L} \SetRowColor{FootBackground} \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}} \\ \SetRowColor{white} \vspace{-5pt} %\includegraphics[width=48px,height=48px]{dave.jpeg} Measure your website readability!\\ www.readability-score.com \end{tabulary} \end{multicols}} \begin{document} \raggedright \raggedcolumns % Set font size to small. Switch to any value % from this page to resize cheat sheet text: % www.emerson.emory.edu/services/latex/latex_169.html \footnotesize % Small font. \begin{multicols*}{3} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Linear-Quadratic Model}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{For some cell lines, the survival curve appears to bend continuously so that the linear- quadratic relation is a better fit. In this case, n has no meaning.} \tn % Row Count 4 (+ 4) % Row 1 \SetRowColor{white} \mymulticolumn{1}{x{5.377cm}}{This model assumes that there are two components to cell killing by radiation, one of which is proportional to dose and the other proportional to the square of the dose.} \tn % Row Count 8 (+ 4) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{1}{x{5.377cm}}{The idea is consistent with results from chromosome work in which many chromosome aberrations (for example, dicentrics) are clearly the result of two separate breaks.} \tn % Row Count 12 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Hallmarks of Cancer}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{There are six classical hallmarks of malignancy:} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Self sufficiency in growth signals}} - malignant cells are able to grow without an external stimulus to do so.} \tn % Row Count 4 (+ 3) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Lack of response to growth inhibition}} - this is often due to loss of tumour suppressor genes, which would normally put the growth of the cell on hold.} \tn % Row Count 8 (+ 4) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Unlimited replicative capacity}} - normal cells may only multiply a set number of times before they become senescent (unable to divide further). Malignant cells circumvent this limit through activation of telomerase.} \tn % Row Count 13 (+ 5) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Avoidance of apoptosis}} - normal cells trigger apoptotic pathways in response to uncontrolled growth signalling. Apoptosis is often suppressed by malignant cells to avoid this fate.} \tn % Row Count 17 (+ 4) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Angiogenesis}} - malignant tumours must form new blood vessels in order to expand locally. Angiogenesis is also important for allowing malignant cells to metastasise.} \tn % Row Count 21 (+ 4) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Invasion and Metastasis}} - malignant tumours invade surrounding normal tissues and may also spread throughout the body.} \tn % Row Count 24 (+ 3) % Row 7 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{{\emph{Two more were later added:}}}}} \tn % Row Count 25 (+ 1) % Row 8 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Deregulation of Cellular Energetics}}: Normal cells produce energy from glucose through glycolysis to pyruvate which then enters the citric acid cycle within the mitochondria. Malignant cells upregulate glycolysis which forms an increased source of energy compared to normal aerobic cells. It can be utilised by FDG PET scanning to identify malignant cells.} \tn % Row Count 33 (+ 8) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Hallmarks of Cancer (cont)}} \tn % Row 9 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Immune Avoidance}}: The immune system is hypothesised to provide protection again malignant transformation of cells by detecting and destroying them. Malignant cells that survive to form a tumour mass must therefore have a means of immune avoidance, either by:} \tn % Row Count 6 (+ 6) % Row 10 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{{\emph{And two additional 'enabling characteristics':}}}}} \tn % Row Count 8 (+ 2) % Row 11 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Genomic Instability:}} The ability of malignant cells to develop a wide array of mutations in multiple oncogenes and tumour suppressor genes suggests a much higher rate of mutation than is seen in normal cells. Malignant cells have been shown to downregulate the normal cellular mechanisms that detect and prevent mutation, allowing them to accelerate the rate of mutation acquisition. The cells with the ability to mutate (or with mutations that have already been acquired) their genome to avoid destruction are those which survive and reproliferate the tumour.} \tn % Row Count 20 (+ 12) % Row 12 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Tumour Promoting Inflammation}}: Certain autoimmune conditions, such as ulcerative colitis or Sjogren's syndrome, promote the development of malignancy in the afflicted organ. This is due to the carcinogenic effects of inflammation on the target organ. Malignant tumours are frequently infiltrated by cells of the immune system. It is thought that the inflammation caused by this infiltration, rather than helping to overcome the tumour, may in fact help to promote further mutation within the malignancy.} \tn % Row Count 31 (+ 11) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Cancer Cell Biology}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Cancer cells are similar yet distinct to normal cells.} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The features that make them different to normal cells allows them to be singled out for treatment; but these are limited by the similarities possessed between the cancer and normal cells.} \tn % Row Count 6 (+ 4) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Carcinomas}} (most common types of cancer), arise from the cells that cover external and internal body surfaces. Lung, breast, and colon are the most frequent cancers of this type.} \tn % Row Count 10 (+ 4) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Sarcomas}} are cancers arising from cells found in the supporting tissues of the body such as bone, cartilage, fat, connective tissue, and muscle.} \tn % Row Count 13 (+ 3) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Lymphomas}} are cancers that arise in the lymph nodes and tissues of the body's immune system.} \tn % Row Count 15 (+ 2) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Leukemias}} are cancers of the immature blood cells that grow in the bone marrow and tend to accumulate in large numbers in the bloodstream.} \tn % Row Count 18 (+ 3) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Cancer arises from a loss of normal growth control.}} In normal tissues, the rates of new cell growth and old cell death are kept in balance. In cancer, this balance is disrupted.} \tn % Row Count 22 (+ 4) % Row 7 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{This disruption can result from uncontrolled cell growth or loss of a cell's ability to undergo cell suicide by a process called {\bf{apoptosis.}}} \tn % Row Count 25 (+ 3) % Row 8 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{This results in as gradual increase in the number of dividing cells, and creates a growing mass of tissue called a {\bf{tumour}} or {\bf{neoplasm.}}} \tn % Row Count 28 (+ 3) % Row 9 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{If the rate of cell division is relatively rapid, and no "suicide" signals are in place to trigger cell death, the tumour will grow quickly in size; if the cells divide more slowly, tumour growth will be slower. As more and more of these dividing cells accumulate, the normal organisation of the tissue gradually becomes disrupted.} \tn % Row Count 35 (+ 7) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Cancer Cell Biology (cont)}} \tn % Row 10 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Cancers are capable of spreading throughout the body by two mechanisms: {\bf{invasion}} (the direct migration and penetration by cancer cells into neighboring tissues) and {\bf{metastasis}} (penetrate into lymphatic and blood vessels, circulate through the bloodstream, and then invade normal tissues elsewhere in body).} \tn % Row Count 7 (+ 7) % Row 11 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Benign}} tumours cannot spread by invasion or metastasis (grow locally)} \tn % Row Count 9 (+ 2) % Row 12 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Malignant}} tumours ("cancer") are capable of spreading by invasion and metastasis, making them a serious health problem.} \tn % Row Count 12 (+ 3) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Radiosensitivity in Radiation Therapy}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{When a single dose of radiation is delivered to a population of cells that are asynchronous, the effect will be different on cells occupying different phases of the cell cycle at the time of radiation exposure.} \tn % Row Count 5 (+ 5) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{More cells will be killed in the sensitive portion of the cell cycle, such as those at or close to mitosis, while fewer of those in the DNA synthetic phase will be killed.} \tn % Row Count 9 (+ 4) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The overall effect is that a dose of radiation will, to some extent, tend to synchronise the cell population leaving the majority of cells in a resistant phase of the cycle.} \tn % Row Count 13 (+ 4) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{In the clinical situation, the radiation is delivered in many separate dose fractions. In the time between these fractions, movement of cells through the cycle into more sensitive phases may be an important factor in 'sensitising' a cycling population of tumour cells to later doses in this treatment regime.} \tn % Row Count 20 (+ 7) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{This process is termed {\bf{sensitisation due to reassortment}} and it is the first of what are referred to as the five Rs of radiobiology.} \tn % Row Count 23 (+ 3) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Variation of Radiosensitivity in the Cell Cycle}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{In the discussion on survival curves, we assume that the population of irradiated cells is asynchronous; that is, it consistes of cells distributed throughout all phases of the cell cycle} \tn % Row Count 4 (+ 4) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Techniques now make it possible to study the variation of radiosensitivity with the position or age of the cell in the cell cycle. These include: the mitotic harvest technique and the hydroxyurea technique.} \tn % Row Count 9 (+ 5) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Mitotic Harvest Technique}}can be used for cultures that grow in monolayers attached to the surface of the growth dish.} \tn % Row Count 12 (+ 3) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Cells close to mitosis round up and become loosely attached. If the culture flasks are gently shaken, the mitotic cells will detach from the surface and float in the medium.} \tn % Row Count 16 (+ 4) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{If these cells are removed and incubated in new dishes, the cells will move together synchronously in step through their mitotic cycle for a few cell division cycles. By delivering a dose of radiation at various times after the initial harvestingwe can irradiate cells at various phases of the cell cycle.} \tn % Row Count 23 (+ 7) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Hydroxyurea Technique}} involves the use of the drug hydroxyurea.} \tn % Row Count 25 (+ 2) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Following the addition of the drug, cells that are in S phase (that is, synthesising DNA) are killedand cells that are in G2, M and G1 are halted at the end of the G1 period.} \tn % Row Count 29 (+ 4) % Row 7 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The drug is only added for a period equal to the combined G2, M and G1 time for that particular cell line. After this time, all the viable cells are poised at the end of G1 ready to enter S phase. If the drug is removed the synchronised cells proceed through the cell cycle. This technique can be used to produce synchronously dividing cell populations in tissue as well as in culture.} \tn % Row Count 37 (+ 8) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Variation of Radiosensitivity in the Cell Cycle (cont)}} \tn % Row 8 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Irradiation of Synchronously Dividing Cell Cultures }}} \tn % Row Count 2 (+ 2) % Row 9 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{When Chinese hamster cells, harvested at mitosis, are irradiated with a single dose of x- rays at various times afterwards, the fraction of cells surviving varies with different phases of the cell cycle.} \tn % Row Count 7 (+ 5) % Row 10 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Following a dose of 6.6 Gy of x-rays, the surviving fraction is about 13\% when the cells are in G1 and increases to more than 40\% near the end of S phase.} \tn % Row Count 11 (+ 4) % Row 11 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Complete survival curves for mitotic cells (M), and for cells in G1 and G2 and for cells in early and late S can be obtained by repeating the procedure for various radiation doses. The most sensitive cells are those in M and G2 indicated by a steep curve with no shoulder. Cells in late S exhibit a survival curve that is less steep with a broad shoulder, and cells in G1 and early S are intermediate in sensitivity.} \tn % Row Count 20 (+ 9) % Row 12 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Application For Tissues}}} \tn % Row Count 21 (+ 1) % Row 13 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The variation in response with the phase of the cell cycle at which the radiation is given is very similar to that observed in many cells cultured in vitro. There is a radiosensitive period between G1 and S and maximum radioresistance occurs in late S phase.} \tn % Row Count 27 (+ 6) % Row 14 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The reasons for the sensitivity changes through the cell cycle are not at all understood but a number of correlations have been observed:} \tn % Row Count 30 (+ 3) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Variation of Radiosensitivity in the Cell Cycle (cont)}} \tn % Row 15 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{1. minimum radiosensitivity coincides with DNA doubling in the S phase;} \tn % Row Count 2 (+ 2) % Row 16 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{2. maximum radiosensitivity occurs just before mitosis when the chromosomes condense; and} \tn % Row Count 4 (+ 2) % Row 17 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{3. radiosensitivity varies with levels of naturally occurring sulfhydryl compounds (powerful radioprotectors) which are at their highest levels in S and at their lowest near mitosis.} \tn % Row Count 8 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{The Cell Cycle}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/molly_1476964796_Capture.PNG}}} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{The Cell Cycle}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Every biological species has its own sensitivity to ionising radiation, that is, its own radiosensitivity.} \tn % Row Count 3 (+ 3) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{his is not the same in all phases of a cell's life; cell death requires a greater or lesser dose, depending on when in the cycle radiation is given.} \tn % Row Count 6 (+ 3) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The basic division of the cell cycle is into that of {\bf{mitosis}} (M) and {\bf{interphase}} (G1, S, G2).} \tn % Row Count 8 (+ 2) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Cells may also be in a special state known as G0 or {\bf{'resting phase'}}, where the cell is not making any effort to divide.} \tn % Row Count 11 (+ 3) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{We can divide the cell cycle into four recognisable stages:} \tn % Row Count 13 (+ 2) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{G1}} is the stage between reproduction episodes.} \tn % Row Count 14 (+ 1) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{S}} is the stage when new DNA is synthesised.} \tn % Row Count 15 (+ 1) % Row 7 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{G2}} is the stage when certain protein and RNA molecules are synthesised.} \tn % Row Count 17 (+ 2) % Row 8 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{M}} is the stage when cells, having replicated DNA and chromosomes, divide to produce two cells from one.} \tn % Row Count 20 (+ 3) % Row 9 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Mitosis}} is subdivided into several events:} \tn % Row Count 21 (+ 1) % Row 10 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Prophase}} – The cell begins to assemble the mitotic spindle, a set of microtubules extending from the centromeres which will later attach to the chromosomes.} \tn % Row Count 25 (+ 4) % Row 11 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Prometaphase}} – The nuclear envelope disintegrates, and the microtubules of the mitotic spindle attach to the chromosomes.} \tn % Row Count 28 (+ 3) % Row 12 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Metaphase}} – The chromosomes are aligned on the mitotic spindle. There is a pause here to allow all chromosomes to become attached.} \tn % Row Count 31 (+ 3) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{The Cell Cycle (cont)}} \tn % Row 13 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Anaphase}} – The cohesion proteins which bind the sister chromatids together are cleaved and the chromosomes are pulled apart by the mitotic spindle.} \tn % Row Count 4 (+ 4) % Row 14 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Telophase}} – The nuclear membrane reconstitutes around each set of chromosomes.} \tn % Row Count 6 (+ 2) % Row 15 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The length of time required for the reproduction phases S, G2 and M does not vary very much among mammalian cells. It is the time between reproduction episodes (G1) that varies} \tn % Row Count 10 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Linear-Quadratic Model cont.}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{A characteristic of the linear-quadratic formulation is that the cell-survival curve is continuously bending.} \tn % Row Count 3 (+ 3) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The extent of the curviness is a function of the relative values of α and β.} \tn % Row Count 5 (+ 2) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{This does not coincide with what is observed experimentally when survival curves are determined down to 7 or more decades (powers of 10) of cell killing.} \tn % Row Count 9 (+ 4) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Here, the curve closely approximates to an exponential function of dose. However, in the first one or two decades of cell killing and up to any doses used as daily fractions in clinical radiotherapy, the linear-quadratic model is an adequate representation of the data.} \tn % Row Count 15 (+ 6) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Responses of tissues to radiotherapy can be predicted from the ratio α/β} \tn % Row Count 17 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Linear-Quadratic Model}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/molly_1476962468_Capture.PNG}}} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Normal Cell Biology}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{There are two major compartments in the cell:} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The {\bf{cytoplasm}} contains the structures of the cell outside of the nucleus. The {\bf{cell membrane}} forms the boundary of the cytoplasm and the cell.} \tn % Row Count 4 (+ 3) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The {\bf{nucleus}} is the central, darker staining part of the cell which contains the chromosomes.} \tn % Row Count 6 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Multi-target Model}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{In this model, the survival curve is described in terms of:} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{1. D1, the dose required to reduce the fraction of surviving cells to 0.37 on the initial portion of the curve {\bf{(single-hit killing),}}} \tn % Row Count 5 (+ 3) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{2. D0, the dose required to reduce survival from 0.1 to 0.037 or from 0.01 to 0.0037 on the final straight portion of the curve {\bf{(multi-hit killing),}}} \tn % Row Count 9 (+ 4) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{3. n, the extrapolation number, or Dq, the quasi-threshold, which are a measure of the width of the shoulder.} \tn % Row Count 12 (+ 3) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{If n is large (for example, 10 or 12), the survival curve has a broad shoulder. If n is small (for example, 1.5 to 2), the shoulder is narrow. A threshold dose is the dose below which radiation produces no effect, so there can be no true threshold; Dq, the quasi- threshold dose, is the closest thing.} \tn % Row Count 19 (+ 7) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{For high-LET radiation D1 = D0 and Dq = 0, however for low-LET D1 \textgreater{} D0.} \tn % Row Count 21 (+ 2) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The value of D0 usually falls in the range of 1 to 2Gy.} \tn % Row Count 23 (+ 2) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{High and Low LET survival curves}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/molly_1476961123_Capture.PNG}}} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Cell Survival Curves}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Survival curves are usually presented with dose plotted on a linear scale (x-axis) and surviving fraction on a logarithmic scale (y-axis).} \tn % Row Count 3 (+ 3) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{When cells are irradiated by single exposures of varying doses of high-LET radiation (for example, α-particles), an exponential survival curve is obtained.} \tn % Row Count 7 (+ 4) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{When cells are irradiated by single exposures of varying doses of ow-LET radiation (x-rays or γ-rays), the slope is not constant. Initially, the curve is relatively flat, but with a negative slope. This is followed by an inflection (called the shoulder) after which the curve also becomes exponential.} \tn % Row Count 14 (+ 7) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{It is difficult to explain the shape of the cell-survival curve in terms of the biophysical events that have occurred and many theories have been proposed. Two models will be described here: {\bf{Multi-target Model}} and {\bf{Linear-Quadratic Model}}} \tn % Row Count 19 (+ 5) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{X} \SetRowColor{DarkBackground} \mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Plating efficiency (PE)}} \tn \SetRowColor{LightBackground} \mymulticolumn{1}{p{5.377cm}}{\vspace{1px}\centerline{\includegraphics[width=5.1cm]{/web/www.cheatography.com/public/uploads/molly_1476960815_Capture.PNG}}} \tn \hhline{>{\arrayrulecolor{DarkBackground}}-} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Cell Culture Technique}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{A cell survival curve describes the relationship between the radiation dose and the proportion of cells that survive.} \tn % Row Count 3 (+ 3) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{In the cell culture technique, a specimen of normal tissue is chopped into small pieces and treated with the enzyme trypsin.} \tn % Row Count 6 (+ 3) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{This loosens the cells and separates them into a single cell suspension. A known number of the single cells are plated in culture medium in a petri dish and here they attach themselves to the bottom of the dish, which is incubated at 37°C.} \tn % Row Count 11 (+ 5) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{After about 10 days, small isolated colonies of cells are seen in the dish. These are the result of individual cells having undergone a series of cell divisions.} \tn % Row Count 15 (+ 4) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{If the single cells are irradiated soon after they are plated, some of them will be killed and so will not produce colonies.} \tn % Row Count 18 (+ 3) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The ability to undergo five or more cell divisions following irradiation is an indication of cell survival, since these cells are capable of almost indefinite cell multiplication.} \tn % Row Count 22 (+ 4) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Conversely, cell death is indicated by a cell's inability to proliferate and give rise to a visible colony of some 32 - 64 cells (five or six successive doublings).} \tn % Row Count 26 (+ 4) % Row 7 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{This is called {\bf{reproductive death (or mitotic death)}} to distinguish it from death of cells that do not proliferate (for example, nerve, muscle, secretory cells) where cell death may be defined as loss of specific function.} \tn % Row Count 31 (+ 5) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Cell Culture Technique (cont)}} \tn % Row 8 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The process is repeated for a range of doses and from this data, we can plot a cell-survival curve. For higher radiation doses, more cells need to be plated in order to produce a statistically meaningful surviving fraction.} \tn % Row Count 5 (+ 5) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Eukaryotic Genes}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{A {\bf{gene}} is a length of DNA, associated with some function, that may be inherited.} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{In {\bf{eukaryotes}} (nucleated cells), a gene usually consists of:} \tn % Row Count 4 (+ 2) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{A {\bf{transcribed segment}}, which is translated into RNA for some effect:} \tn % Row Count 6 (+ 2) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The transcribed segment contains {\bf{introns}} and {\bf{exons}}; exons are {\bf{ex}}pressed whereas introns are in between exons and are {\bf{in}}cised by splicing mechanics after translation has occurred.} \tn % Row Count 10 (+ 4) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Each end of the transcribed segment contains a 5' and 3' untranslated region. This may allow the cell to recognise sequences of genetic code after they have been transcribed into RNA.} \tn % Row Count 14 (+ 4) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{{\bf{Non-transcribed parts}}, which include:} \tn % Row Count 15 (+ 1) % Row 6 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{{\bf{Regulatory segment(s)}}, which are lengths of DNA allowing the cell to control which genes are expressed.} \tn % Row Count 18 (+ 3) % Row 7 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Start and stop segments which flank the transcribed segment, allowing transcription enzymes to bind.} \tn % Row Count 20 (+ 2) % Row 8 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{The classical gene codes for a protein; the genetic code is transcribed into a strand of RNA by {\bf{RNA polymerase}}.} \tn % Row Count 23 (+ 3) % Row 9 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{This RNA, known as {\bf{pre-messenger RNA}}, undergoes splicing where the introns are removed. Once completed, the messenger RNA is transported to the ribosomes in the cytoplasm for translation into protein.} \tn % Row Count 28 (+ 5) % Row 10 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Other genes code for RNA products that do not require translation into protein. This includes the RNA that forms the ribosome ({\bf{ribosomal RNA}}), or {\bf{micro-RNAs}} which are important in the post-transcription control of gene expression.} \tn % Row Count 33 (+ 5) \end{tabularx} \par\addvspace{1.3em} \vfill \columnbreak \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Eukaryotic Genes (cont)}} \tn % Row 11 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Gene regulatory segments need not be located immediately adjacent to the transcribed segment. Regulatory segments can exert an influence over thousands of base pairs, and different regulatory segments can also interact to enhance (or further suppress) the transcription of a gene.} \tn % Row Count 6 (+ 6) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{The Nucleus}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Contains the {\bf{DNA.}}} \tn % Row Count 1 (+ 1) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{DNA is stored in 44 somatic and two sex chromosomes.} \tn % Row Count 3 (+ 2) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{may also contain a nucleolus, a site of ribosome manufacturing. The double-membrane of the nucleus contains numerous pores which allow proteins and RNA to communicate with the cytoplasm.} \tn % Row Count 7 (+ 4) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} \begin{tabularx}{5.377cm}{p{0.4977 cm} p{0.4977 cm} } \SetRowColor{DarkBackground} \mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{The Cytoplasm}} \tn % Row 0 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Contains numerous organelles which perform cellular functions:} \tn % Row Count 2 (+ 2) % Row 1 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{Mitochondria are energy producing organelles with their own mitochondrial DNA.} \tn % Row Count 4 (+ 2) % Row 2 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Endoplasmic reticulum is involved in the assembly of proteins. Rough endoplasmic reticulum contains ribosomes which translate messenger RNA (Ribonucleic Acid) into protein.} \tn % Row Count 8 (+ 4) % Row 3 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The golgi apparatus is involved in the packaging of protein into membrane bound organelles, either for storage or for delivery to the cell membrane} \tn % Row Count 11 (+ 3) % Row 4 \SetRowColor{LightBackground} \mymulticolumn{2}{x{5.377cm}}{Centrioles are small assemblies of microtubles arranged in a cylinder. They are important localisation of the chromosomes during cell division.} \tn % Row Count 14 (+ 3) % Row 5 \SetRowColor{white} \mymulticolumn{2}{x{5.377cm}}{The {\bf{cytoskeleton}} extends through the cytoplasm, attached to cell membrane proteins. The cytoskeleton helps to cell to keep its shape and is also mobile in some cells (such as neutrophils), altering the shape of the cell and allowing movement. {\bf{Tumour cells}} frequently co-opt the cytoskeleton to allow them to move through tissues.} \tn % Row Count 21 (+ 7) \hhline{>{\arrayrulecolor{DarkBackground}}--} \end{tabularx} \par\addvspace{1.3em} % That's all folks \end{multicols*} \end{document}