Before you watch, discuss with your partner the saying “You are what you eat”. Do you agree with it?

PROFESSIONAL ENGLISH

 

Н.А. Грицай

Е.А. Малашенко

English For Medical Students

 

 

 

Environmental Medicine

 

УДК 811.111 (075.8):

ББК 81.2 Анг-923

М

 

 

Авторы:

Н.А. Грицай, Е.А. Малашенко, И.В. Войтова, Н.М. Левданская, Л.Н. Никитина, Н.Н. Дробыш

 

 

Рецензенты:

Зав.кафедрой современных языков ГУО КИИ МЧС Республики Беларусь, кандидат филологических наук, доцент Т.Г.Ковалева;

Зав. кафедрой экологической и молекулярной генетики,

доктор биологических наук, профессор С.Б. Мельнов

 

Английский язык для студентов медицинских специальностей: учеб. пособие для студентов учреждений высшего образования по специальности «медико-биологическое дело», «Экологическая медицина» / Н.А. Грицай [и др.]; под ред. Н.А. Грицай. – Минск: МГЭУ им. А. Д. Сахарова, 2011. – 120 с.

 

Учебное пособие по профессионально-ориентированному общению предназначено для развития лексических навыков в области специальной терминологии, совершенствовании умений и навыков устной речи, чтения и перевода текстов, имеющих профессиональную значимость для студентов, изучающих экологическую медицину.

Данное пособие предназначено для студентов факультета экологической медицины, а также для разных категорий учащихся, интересующихся проблемами развития медицины в экологическом контексте.

 

Unit 1

FOOD

Vocabulary

 

 

1. Match the words with their definitions:

 

1) nutrient (n.)	['njuːtrɪənt]	a) supply with
2) ingest (v.)	[ɪn'ʤest]	b) undergo chemical decomposition
3) carbohydrate (n.)	[ˌkɑ͟ː(r)boʊ'ha͟ɪdreɪt]	c) an odourless, tasteless white substance occurring widely in plant tissue and generally obtained from cereals and potatoes
4) protein (n.)	['pro͟ʊtiːn]	d) the smallest part of an animal or plant that is able to function independently
5) absorb (v.)	[əb'zɔːb] or [əb'sɔːb]	e) take in (energy or a liquid or other substance) by chemical or physical action
6) bloodstream (n.)	['blʌdstriːm]	f) a substance containing nitrogen and hydrogen and which can be found naturally in the body
7) digest (v.)	[daɪ'ʤest]	g) change the form, character, or function of something
8) provide with smth (v.)	[prə'vaɪd]	h) a substance that provides nourishment essential for the maintenance of life and for growth
9) convert into smth (v.)	[kən'vəːt]	i) separate food in the stomach and intestines into substances
10) break down (phr.v.)	[ˌbreɪk 'da͟ʊn]	j) take (food, drink) into the body by swallowing it
11) cell (n.)	[sel]	k) a substance found in food and drink such as meat, eggs, and milk that people need in order to grow and be healthy
12) amino acid (n.)	[əˌmi͟ːnoʊ 'æsɪd]	l) the red liquid that circulates through the body of a person or animal, carrying oxygen to and carbon dioxide from the tissues of the body
13) starch (n.)	[stɑ͟ː(r)tʃ]	m) a substance found in foods such as sugar, bread and potatoes that people need to supply their bodies with heat and energy

Watching

 

 

Before you watch, discuss with your partner the saying “You are what you eat”. Do you agree with it?

Now watch the clip and be ready to say why nutrition is important.

Before you read

 

You are going to read an article about the basics of food. What do you know about it?

It is safe to say that one thing you’ll do today is eat some food – food is essential to life. But what is food? What’s in food that makes it so important? What is food made of? How does it fuel our bodies? Discuss with your partner the above-mentioned questions. How many of them can you answer?

3. Skim ^[1] the text to check your ideas.

Reading A

THE BASICS OF FOOD (PART I)

by Marshall Brain

Food is any substance consumed to provide nutritional support for the body. Think about some of the things you have eaten today – maybe cereal, bread, milk, juice, ham, cheese, an apple, potatoes... All of these foods are usually of plant or animal origin and contain seven basic components or essential nutrients: carbohydrates (simple and complex), proteins, fats, vitamins, minerals, fiber, and water. The food is ingested by an organism and assimilated by the organism’s cells in an effort to produce energy, maintain life, and/or stimulate growth. So, your body’s goal is to digest food and use it to keep your body alive. Let’s look at each of these basic components to understand what they really do and why they are so important to your body.

Carbohydrates

Carbohydrates provide your body with its basic fuel. The simplest carbohydrate is glucose. Glucose, also called “blood sugar”, flows in the bloodstream so that it is available to every cell in your body. Your cells absorb glucose and convert it into energy to drive the cell.

The word “carbohydrate” comes from the fact that glucose is made up of carbon and water. The chemical formula for glucose is: C₆H₁₂O₆. Glucose is a simple sugar, meaning that to our tongues it tastes sweet. There are other simple sugars: fructose (the main sugar in fruits), sucrose (also known as “white sugar” or “table sugar”), lactose (the sugar found in milk), galactose, and maltose (the sugar found in malt).

Glucose, fructose and galactose are monosaccharides and are the only carbohydrates that can be absorbed into the bloodstream through the intestinal lining. Lactose, sucrose and maltose are disaccharides (they contain two monosaccharides) and are easily converted to their monosaccharide bases by enzymes in the digestive tract. Monosaccharides and disaccharides are called simple carbohydrates and are also sugars. They all digest quickly and enter the bloodstream quickly.

There are also complex carbohydrates, commonly known as “ starches ”. A complex carbohydrate is made up of chains of glucose molecules. Starches are the way plants store energy – plants produce glucose and chain the glucose molecules together to form starch. Most grains (wheat, corn, oats, rice) and things like potatoes and plantains are high in starch. Your digestive system breaks a complex carbohydrate (starch) back down into its component glucose molecules so that the glucose can enter your bloodstream. It takes a lot longer to break down a starch, however. A complex carbohydrate is digested more slowly, so glucose enters the bloodstream at a rate of only 2 calories per minute.

Insulin is incredibly important to the way the body uses the glucose that foods provide. It is a simple protein in which two polypeptide chains of amino acids are joined by disulfide linkages. It helps transfer glucose into cells so that they can oxidize the glucose to produce energy for the body. In adipose (fat) tissue, insulin facilitates the storage of glucose and its conversion to fatty acids. Insulin also slows the breakdown of fatty acids. In muscle it promotes the uptake of amino acids for making proteins. In the liver it helps convert glucose into glycogen (the storage carbohydrate of animals) and it decreases gluconeogenesis (the formation of glucose from noncarbohydrate sources). The action of insulin is opposed by glucagon, another pancreatic hormone, and by epinephrine.

Proteins

A protein is any chain of amino acids. An amino acid is a small molecule that acts as the building block of any cell. Carbohydrates provide cells with energy, while amino acids provide cells with the building material they need to grow and maintain their structure. Your body is about 20-percent protein and about 70-percent water by weight. Most of the rest of your body is composed of minerals (for example, calcium in your bones). Amino acids are called “amino acids” because they all contain an amino group (NH₂) and a carboxyl group (COOH), which is acidic. The human body is constructed of 20 different amino acids.

As far as your body is concerned, there are two different types of amino acids: essential that your body can create out of other chemicals found in your body and non-essential that cannot be created, and therefore the only way to get them is through food. Here are the different amino acids: non-essential (alanine, arginine, asparagines, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, tyrosine); essential (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine).

Protein in our diets comes from both animal and vegetable sources. Most animal sources (meat, milk, eggs) provide what’s called “complete protein”, meaning that they contain all of the essential amino acids. Vegetable sources usually are low on or missing certain essential amino acids. However, different vegetable sources are deficient in different amino acids, and by combining different foods you can get all of the essential amino acids throughout the course of the day. Some vegetable sources contain quite a bit of protein – things like nuts, beans, soybeans, etc. are all high in protein.

The digestive system breaks all proteins down into their amino acids so that they can enter the bloodstream. Cells then use the amino acids as building blocks.

Carbohydrate, protein, and fat are the main sources of calories in the diet and are called macronutrients. Both carbohydrates and proteins provide 4 calories per gram.

http://recipes.howstuffworks.com/food.htm

Reading Comprehension

You are going to read an article which provides information and advice for choosing a balanced diet. The terms “eating pattern”, “calorie balance” and “nutrient-dense foods” are essential to understanding the principles and recommendations presented in the article. Discuss with your partner (or in groups) what the terms mentioned above mean.

What keeps people healthy?

 

BAD HABITS

SMOKING

Vocabulary

1. Match the words with their definitions:

1) alter (v.)	['ɔːltə]	a) a poisonous gas that is produced especially by the engines of vehicles
2) belligerent (adj.)	[bɪ'lɪʤər(ə)nt]	b) breath out
3) inhalation (n.)	[ˌɪnhə'leɪʃ(ə)n]	c) stop or discontinue (an action or activity)
4) carbon monoxide (n.)	['kɑːbənmɔ'nɔksaɪd]	d) change or cause to change in character or composition, typically in a comparatively small but significant way
5) susceptible (adj.)	[sə'septəbl]	e) feel a powerful desire for (something)
6) ambient (adj.)	['æmbɪənt]	f) a cavity within a bone or other tissue, especially one in the bones of the face or skull connecting with the nasal cavities
7) spouse (n.)	[spauz]	g) the process or act of breathing in, taking air and sometimes other substances into your lungs.
8) exhale (v.)	[eks'heɪl]	h) relating to the immediate environs of something
9) sinus (n.)	['saɪnəs]	i) a husband or wife, considered in relation to their partner
10) quit (v.)	[kwɪt]	j) likely or liable to be influenced or harmed by a particular thing
11) crave(v.)	[kreɪv]	k) hostile and aggressive

Listening & Watching

Before you read

ALCOHOL

Vocabulary

 

1. Match the words with their definitions:

 

1) overlooked (V3)	[ˌəuvə'lukt]	a)embryonic
2) hangover (n.)	['hæŋˌəuvə]	b)a disease which destroys a person's liver and which can kill them
3) contemporaries (n.)	[kən'temp(ə)r(ə)rɪs]	c)inflammation of the pancreas
4) full of yourself (inf)	[fuləvjəself]	d) to hit sb. many times, using fists or a heavy object
5) inhibition (n.)	[ˌɪnhɪ'bɪʃ(ə)n]	e)fail to function normally or satisfactorily
6) blurred vision	[blɜːd 'vɪʒ(ə)n]	f)the experience of seeing something that is not really there because you are ill or have taken a drug
7) remorse (n.)	[rɪ'mɔːs]	g)people of the same age
8) hallucination (n.)	[həˌluːsɪ'neɪʃ(ə)n]	h)(make or become unclear or less distinct
9) batter (v.)	['bætə]	i)very self-confident
10)fetal (adj.)	['fiːt(ə)l]	j)missed, not noticed
11) pancreatitis (n.)	[ˌpæŋkrɪə'taɪtɪs]	k)a strong feeling of sadness and regret about something wrong that you have done
12) malfunction (n.)	[ˌmæl'fʌŋkʃ(ə)n]	l)feelings of fear or embarrassment that make it difficult for you to behave naturally
13)cirrhosis (n.)	[sɪ'rəusɪs]	m)headache and tiredness a few hours after drinking too much

Listening

 

DRUGS

Vocabulary

2. Match the words with their definitions:

1) analgesic (adj.)	[ˌænəl'ʤiːzɪk]	a) is used to produce hemp fibre and as a psychotropic drug
2) barbiturate (n.)	[bɑː'bɪtjurət]	b) an infusion of one thing into another
3) remedy	['remədɪ]	c) the leaves of an Arabian shrub, which are chewed (or drunk as an infusion) as a stimulant
4) rite (n.)	[raɪt]	d) a synthetic, addictive, mood-altering drug, used illegally as a stimulant
5)medicinal (adj.)	[mə'dɪs(ə)n(ə)l]	e)make excessive and habitual use of
6) cannabis (n.)	['kænəbɪs]	f) a medicine or treatment for a disease or injury
7) solvent (n.)	['sɔlvənt]	g) having healing properties
8) khat (n.)	[kɑːt]	h) a person or thing that is likely to cause harm; a threat or danger
9) amphetamine (n.)	[æm'fetəmiːn]	i) a religious or other solemn ceremony or act
10) injection (n.)	[ɪn'ʤekʃ(ə)n]	j)a liquid, typically one other than water, used for dissolving other substances
11) menace (n.)	['menɪs ], ['menəs]	k) a drug which people take to make them calm or to help them to sleep
12) abuse (v.)	[ə'bjuːs]	l) acting to relieve pain

Listening & Watching

 

 

Before you read

1. You are going to read an article written by a mental health consultant. He was former Regional Adviser in Mental Health for WHO (World Health Organization) in Alexandria. What do you know you about drugs?

PROBLEMS WITH DRUGS

by Dr Taha Baasher

For centuries men and women have been seeking not only the euphoric, but also the analgesic effects of narcotics. In the last century, Sir William Osler described this situation so well when he said, "The desire to take medicine is, perhaps, the greatest feature which distinguishes man from animals".

Throughout the history of mankind, nearly all countries and cultures have had problems with the use and abuse of drugs. Since the earliest recorded times, drugs have been used for different reasons – mainly religious, medicinal and pleasure. For example, alcohol and opium were both well known in ancient Egyptian culture. Cannabis was commonly used in Hindu ceremonial rites as well as in Indian and Chinese medicine. Drug related problems, therefore, are not new.

Today, drug problems have become more varied, becoming both more complicated and more global in character. Natural drugs – such as cannabis, cocaine, khat (qat) and opium – which had previously only been used in certain cultures and within traditional ways of life, have been increasingly exploited and their use now reaches epidemic level. Also, manufactured drugs such as amphetamine, barbiturates and a wide range of sedatives and tranquillizers have become more easily available, both through legal and illegal markets.

Added to these is the growing habit among young people in some countries of sniffing solvents in paints and glues. Levels of drug abuse are rising in most countries. Drugs are taken more often and in greater quantities. There is also a trend towards using a mixture of different drugs or combining drugs with alcohol. Cocaine misuse needs special attention. It is the most dependence-producing drug available. Currently its misuse is reaching epidemic levels in some parts of the world and it is rapidly spreading to other areas. Traditional coca chewing in the Andes is being replaced by coca paste smoking in cities in South America. Opium eating among rural cultures in South Asia has developed into the much more dangerous use of heroin in the form of smoking or by injection. Drugs are supposed to do wonderful things but all they really do is ruin the person.

The drug scene brings with it a wide range of social and economic problems, including crime, violence and neglect of family life. Concern is growing in many countries over levels of drug abuse.

In order to prevent drug abuse it is important to identify the main reasons for using a drug. Next, practical efforts should be made to overcome this motivation. The reasons for using drugs are very varied within each culture. Even within the same country, preventative programmes may need to vary according to local problems.

In north east Afghanistan and in some areas of Pakistan, India, Myanmar and Thailand where rural health services are lacking, opium is used as a household remedy and for overcoming pain and discomfort caused by cold weather and the hardships of life. Emphasis must therefore be given to these priority needs before the drug problem can be dealt with.

What should be prevented? Who should do the preventing? On an official level there are international agreements to control the movement and export of drugs. On a national level, control depends on the police and customs and government measures. On the whole, the best preventative measures are those which are developed by people within their own culture and social life. Religious groups can play an effective preventative role against the abuse of alcohol and tobacco through their teaching about moral values and self discipline.

Drug abuse problems are among the most damaging menacesof modern life. Their effective prevention calls for huge efforts from government authorities, widespread education and awareness raising campaigns and active community participation.

http://tilz.tearfund.org

Reading Comprehension

Writing

Design an anti-smoking poster for schools or universities. Sketch a picture or use photos from a magazine; write a slogan and a couple of sentences to go with it.

UNIT 4

You are going to read an article in the form of a chart about the revolutionary discoveries that transformed the world of medicine to what it is today. Think of five greatest discoveries on the field of medicine and put them in order of importance for you. What do you think is the most important medical discovery in the last 100-200 years and why? Give your reasons.

· Compare your answers with a partner

MEDICAL ADVANCES TIMELINE

460 BCE	Birth of Hippocrates, Greek physician and founder of the first university. Considered the father of medicine. Hippocrates bases medicine on objective observation and deductive reasoning, although he does accept the commonly held belief that disease results from an imbalance of the four bodily humors (an idea that persists for centuries).
c.130 CE	Birth of Galen, considered by many to be the most important contributor to medicine following Hippocrates. Born of Greek parents, Galen resides primarily in Rome where he is physician to the gladiators and personal physician to several emperors. He publishes some 500 treatises and is still respected for his contributions to anatomy, physiology, and pharmacology.
	Persian physician Rhazes is the first to identify smallpox, as distinguished from measles, and to suggest blood as the cause of infectious disease.
	Dutch lens grinder Zacharius Jannssen invents the microscope
	William Harvey publishes An Anatomical Study of the Motion of the Heart and of the Blood in Animals, describing how blood is pumped throughout the body by the heart, and then returns to the heart and recirculates. The book is very controversial but becomes the basis for modern research on the heart and blood vessels.
	Experimenting on dogs, English architect Sir Christopher Wren is the first to administer medications intravenously by means of an animal bladder attached to a sharpened quill. Wren also experiments with canine blood transfusions (although safe human blood transfusions only became feasible after Karl Landsteiner develops the ABO blood-typing system in 1900).
	Anton van Leeuwenhoek refines the microscope and fashions nearly 500 models. Discovers blood cells and observes animal and plant tissues and microorganisms.
	James Lind, a Scottish naval surgeon, discovers that citrus fruits prevent scurvy. He publishes his Treatise of the Scurvy in 1754, identifying the cure for this common and dangerous disease of sailors, although it takes another 40 years before an official Admiralty order dictates the supply of lemon juice to ships.
	Edward Jenner develops a method to protect people from smallpox by exposing them to the cowpox virus. In his famous experiment, he rubs pus from a dairymaid's cowpox postule into scratches on the arm of his gardener's 8-year-old son, and then exposes him to smallpox six weeks later (which he does not develop). The process becomes known as vaccination from the Latin vacca for cow. Vaccination with cowpox is made compulsory in Britain in 1853. Jenner is sometimes called the founding father of immunology.
	Sir Humphry Davy announces the anesthetic properties of nitrous oxide, although dentists do not begin using the gas as an anesthetic for almost 45 years.
	René Laënnec invents the stethoscope.
	British obstetrician James Blundell performs the first successful transfusion of human blood.
	American surgeon Crawford W. Long uses ether as a general anesthetic during surgery but does not publish his results. Credit goes to dentist William Morton.
	Dr. Horace Wells, American dentist, uses nitrous oxide as an anesthetic.
	Boston dentist Dr. William Morton demonstrates ether's anesthetic properties during a tooth extraction.
	Elizabeth Blackwell is the first woman to receive a medical degree (from Geneva Medical College in Geneva, New York).
	Joseph Lister publishes Antiseptic Principle of the Practice of Surgery, one of the most important developments in medicine. Lister was convinced of the need for cleanliness in the operating room, a revolutionary idea at the time. He develops antiseptic surgical methods, using carbolic acid to clean wounds and surgical instruments. The immediate success of his methods leads to general adoption. In one hospital that adopts his methods, deaths from infection decrease from nearly 60% to just 4%.
1870s	Louis Pasteur and Robert Koch establish the germ theory of disease. According to germ theory, a specific disease is caused by a specific organism. Before this discovery, most doctors believe diseases are caused by spontaneous generation. In fact, doctors would perform autopsies on people who died of infectious diseases and then care for living patients without washing their hands, not realizing that they were therefore transmitting the disease.
	First vaccine for cholera
	First vaccine for anthrax
	First vaccine for rabies
	Emil von Behring discovers antitoxins and uses them to develop tetanus and diphtheria vaccines.
	German physicist Wilhelm Conrad Roentgen discovers X rays.
	First vaccine for typhoid fever.
	Ronald Ross, a British officer in the Indian Medical Service, demonstrates that malaria parasites are transmitted via mosquitoes, although French army surgeon Charles Louis Alphonse Laveran identified parasites in the blood of a malaria patient in 1880. The treatment for malaria was identified much earlier (and is still used today). The Qinghao plant (Artemisia annua) was described in a Chinese medical treatise from the 2nd century BCE; the active ingredient, known as artemisinin, was isolated by Chinese scientists in 1971 and is still used today. The more commonly known treatment, quinine, was derived from the bark of a tree called Peruvian bark or Cinchona and was introduced to the Spanish by indigenous people in South America during the 17th century.
	First vaccine for plague.
	Felix Hoffman develops aspirin (acetyl salicylic acid). The juice from willow tree bark had been used as early as 400 BC to relieve pain. 19th century scientists knew that it was the salicylic acid in the willow that made it work, but it irritated the lining of the mouth and stomach. Hoffman synthesizes acetyl salicylic acid, developing what is now the most widely used medicine in the world.
	Austrian-American Karl Landsteiner describes blood compatibility and rejection (i.e., what happens when a person receives a blood transfusion from another human of either compatible or incompatible blood type), developing the ABO system of blood typing. This system classifies the bloods of human beings into A, B, AB, and O groups. Landsteiner receives the 1930 Nobel Prize for Physiology or Medicine for this discovery.
	Sir Frederick Gowland Hopkins suggests the existence of vitamins and concludes they are essential to health. Receives the 1929 Nobel Prize for Physiology or Medicine.
	First successful human blood transfusion using Landsteiner's ABO blood typing technique
	Dr. Paul Dudley White becomes one of America's first cardiologists, a doctor specializing in the heart and its functions, and a pioneer in use of the electrocardiograph, exploring its potential as a diagnostic tool.
	Edward Mellanby discovers vitamin D and shows that its absence causes rickets.
	Insulin first used to treat diabetes.
	First vaccine for diphtheria.
	First vaccine for pertussis (whooping cough).
	First vaccine for tuberculosis.
	First vaccine for tetanus.
	Scottish bacteriologist Sir Alexander Fleming discovers penicillin. He shares the 1945 Nobel Prize for Physiology or Medicine with Ernst Chain and Sir Howard Florey.
	First vaccine for yellow fever.
	Dr. John H. Gibbon, Jr., successfully uses a heart-lung machine for extracorporeal circulation of a cat (i.e., all the heart and lung functions are handled by the machine while surgery is performed). Dr. Gibbon uses this method successfully on a human in 1953. It is now commonly used in open heart surgery.
	First vaccine for typhus.
	Bernard Fantus starts the first blood bank at Cook County Hospital in Chicago, using a 2% solution of sodium citrate to preserve the blood. Refrigerated blood lasts ten days.
	Microbiologist Selman A. Waksman discovers the antibiotic streptomycin, later used in the treatment of tuberculosis and other diseases.
	First vaccine for influenza.
	Paul Zoll develops the first cardiac pacemaker to control irregular heartbeat.
	James Watson and Francis Crick at Cambridge University describe the structure of the DNA molecule. Maurice Wilkins and Rosalind Franklin at King's College in London are also studying DNA. (Wilkins in fact shares Franklin's data with Watson and Crick without her knowledge.) Watson, Crick, and Wilkins share the Nobel Prize for Physiology or Medicine in 1962 (Franklin had died and the Nobel Prize only goes to living recipients).
	Dr. Joseph E. Murray performs the first kidney transplant between identical twins.
	Jonas Salk develops the first polio.
	Dr. Willem Kolff and Dr. Tetsuzo Akutzu implant the first artificial heart in a dog. The animal survives 90 minutes.
	First oral polio vaccine (as an alternative to the injected vaccine).
	First vaccine for measles.
	First vaccine for mumps.
	South African heart surgeon Dr. Christiaan Barnard performs the first human heart transplant.
	First vaccine for rubella.
	First vaccine for chicken pox.
	First vaccine for pneumonia.
	First test-tube baby is born in the U.K.
	First vaccine for meningitis.
	W.H.O. (World Health Organization) announces smallpox is eradicated.
	First vaccine for hepatitis B.
	Dr. William DeVries implants the Jarvik-7 artificial heart into patient Barney Clark. Clark lives 112 days.
	HIV, the virus that causes AIDS, is identified.
	First vaccine for hepatitis A.
	Dolly the sheep becomes the first mammal cloned from an adult cell (dies in 2003).
	First vaccine for lyme disease.
	Scientists discover how to use human skin cells to create embryonic stem cells.

 

 

http://www.infoplease.com/ipa/A0932661.htm

Reading Comprehension

You are going to read an extract from Wikipedia the encyclopedia about the discovery of antibiotics, the powerful substances that saved the world. So, first of all, discuss with your partner the following questions.

- Why antibiotics can be called one of the advances in medicine?

- What are antibiotics and how do they work?

- What outstanding scientists discovered antibiotics?

- When and how was the discovery made?

ANTIBIOTICS

Before the early twentieth century, treatments for infections were based primarily on medicinal folklore. Mixtures with antimicrobial properties that were used in treatments of infections were described over 2000 years ago. Many ancient cultures, including the ancient Egyptians and ancient Greeks used specially selected mold and plant materials and extracts to treat infections. More recent observations made in the laboratory of antibiosis between micro-organisms led to the discovery of natural antibacterials produced by microorganisms. The term antibiosis, meaning "against life," was introduced by the French bacteriologist Vuillemin as a descriptive name of the phenomenon exhibited by these early antibacterial drugs.

Antibiosis was first described in 1877 in bacteria when Louis Pasteur and Robert Koch observed that an airborne bacillus could inhibit the growth of Bacillus anthracis. These drugs were later renamed antibiotics by Selman Waksman, an American microbiologist in 1942.

The successful outcome of antimicrobial therapy with antibacterial compounds depends on several factors. These include host defense mechanisms, the location of infection, and the pharmacokinetic and pharmacodynamic properties of the antibacterial. A bactericidal activity of antibacterials may depend on the bacterial growth phase, and it often requires ongoing metabolic activity and division of bacterial cells. These findings are based on laboratory studies, and in clinical settings have also been shown to eliminate bacterial infection. Since the activity of antibacterials depends frequently on its concentration, in vitro characterization of antibacterial activity commonly includes the determination of the minimum inhibitory concentration and minimum bactericidal concentration of an antibacterial. To predict clinical outcome, the antimicrobial activity of an antibacterial is usually combined with its pharmacokinetic profile, and several pharmacological parameters are used as markers of drug efficacy.

Like antibiotics, antibacterials are commonly classified based on their mechanism of action, chemical structure, or spectrum of activity. Most antibacterial antibiotics target bacterial functions or growth processes. Antibiotics that target the bacterial cell wall (such as penicillins and cephalosporins), or cell membrane (for example, polymixins), or interfere with essential bacterial enzymes (such as quinolones and sulfonamides) have bactericidal activities. Those that target protein synthesis, such as the aminoglycosides, macrolides, and tetracyclines, are usually bacteriostatic. Further categorization is based on their target specificity. "Narrow-spectrum" antibacterial antibiotics target specific types of bacteria, such as Gram-negative or Gram-positive bacteria, whereas broad-spectrum antibiotics affect a wide range of bacteria. Following a 40-year hiatus in discovering new classes of antibacterial compounds, three new classes of antibiotics have been brought into clinical use. These new antibacterials are cyclic lipopeptides (including daptomycin), glycylcyclines (e.g., tigecycline), and oxazolidinones (including linezolid).

The emergence of resistance of bacteria to antibacterial drugs is a common phenomenon. Emergence of resistance often reflects evolutionary processes that take place during antibacterial drug therapy. The antibacterial treatment may select for bacterial strains with physiologically or genetically enhanced capacity to survive high doses of antibacterials. Under certain conditions, it may result in preferential growth of resistant bacteria while growth of susceptible bacteria is inhibited by the drug. For example, antibacterial selection within whole bacterial populations for strains having previously acquired antibacterial-resistance genes was demonstrated in 1943 by the Luria–Delbrück experiment. Survival of bacteria often results from an inheritable resistance. Resistance to antibacterials also occurs through horizontal gene transfer. Horizontal transfer is more likely to happen in locations of frequent antibiotic use.

Antibacterials like penicillin and erythromycin, which used to have high efficacy against many bacterial species and strains, have become less effective, because of increased resistance of many bacterial strains. Antibacterial resistance may impose a biological cost thereby reducing fitness of resistant strains, which can limit the spread of antibacterial-resistant bacteria, for example, in the absence of antibacterial compounds. Additional mutations, however, may compensate for this fitness cost and can aid the survival of these bacteria.

Several molecular mechanisms of antibacterial resistance exist. Intrinsic antibacterial resistance may be part of the genetic makeup of bacterial strains. For example, an antibiotic target may be absent from the bacterial genome. Acquired resistance results from a mutation in the bacterial chromosome or the acquisition of extra-chromosomal DNA. Antibacterial-producing bacteria have evolved resistance mechanisms that have been shown to be similar to, and may have been transferred to, antibacterial-resistant strains. The spread of antibacterial resistance often occurs through vertical transmission of mutations during growth and by genetic recombination of DNA by horizontal genetic exchange. For instance, antibacterial resistance genes can be exchanged between different bacterial strains or species via plasmids that carry these resistance genes. Plasmids that carry several different resistance genes can confer resistance to multiple antibacterials. Cross-resistance to several antibacterials may also occur when a resistance mechanism encoded by a single gene conveys resistance to more than one antibacterial compound.

Antibacterial-resistant strains and species, sometimes referred to as "superbugs", now contribute to the emergence of diseases which were for a while well-controlled. For example, emergent bacterial strains causing tuberculosis (TB) that are resistant to previously effective antibacterial treatments pose many therapeutic challenges. Every year, nearly half a million new cases of multidrug-resistant tuberculosis (MDR-TB) are estimated to occur worldwide. For example, NDM-1 is a newly identified enzyme conveying bacterial resistance to a broad range of beta-lactam antibacterials. United Kingdom Health Protection Agency has stated that "most isolates with NDM-1 enzyme are resistant to all standard intravenous antibiotics for treatment of severe infections."

Antibiotic resistance is a problem because infections due to resistant bacteria are more difficult to treat, may result in longer and more severe illness, or expensive hospitalizations, and may need treatment with stronger antibiotics that can cause more serious side-effects. The problem of antibiotic resistance is getting worse. As the number of resistant bacteria grows, we may lose the ability to cure bacterial infections and people may die from common infections like pneumonia.

The misuse and overuse of antibiotics in humans, animals, and agriculture is responsible for the current problem of antibiotic resistance. Humans contribute to the problem in several ways:

· Taking antibiotics when they are not necessary, such as for viral infections.

· Demanding antibiotics when antibiotics are not appropriate OR insisting on a prescription for an antibiotic when your doctor says they are not necessary.

· Not taking your prescribed antibiotic for the full course of treatment.

· Using antibiotics without a doctor's care or using leftover antibiotics.

It is estimated that up to 50% of antibiotics used in humans may be inappropriate. Most of this inappropriate use is for illnesses due to viruses-- against which antibiotics are ineffective. It is very important to do what we can to slow resistance now. The best way to do that is to reduce inappropriate antibiotic use.

From Wikipedia, the free encyclopedia

Reading Comprehension

Read the article again and decide if the following statements are true (T), false (F) or not stated (NS). Find in the article the sentences that can prove the true statements and correct the false statements.

1. The antibiotic therapy goes back to ancient medicine.

2. The immune system doesn’t play any role in the successful result of antimicrobial therapy.

3. The activity of antibacterials depends only on their concentration.

4. Antibacterial resistance is genetically proved.

5. Bacteria mutations can contribute into antibiotic resistance.

6. Today there are different ways to avoid antibiotic resistance.

7. Doctors should always prescribe antibiotics.

Language Development

 

ǃ Participles

Role play

A New Biological Era

The knowledge of how genetic material is stored and copied has given rise to a new way of looking at and manipulating biological processes, called molecular biology. With the help of so-called restriction enzymes, molecules that cut the DNA at particular stretches, pieces of DNA can be cut out or inserted at different places.

In basic science, where you want to understand the role of all the different genes in humans and animals, new techniques have been developed. For one thing, it is now possible to make mice that are genetically modified and lack particular genes. By studying these animals scientists try to figure out what that gene may be used for in normal mice. This is called the knockout technique, since stretches of DNA have been taken away, or knocked out.

Scientists have also been able to insert new bits of DNA into cells that lack particular pieces of genes or whole genes. With this new DNA, the cell becomes capable of producing gene products it could not make before. The hope is that, in the future, diseases that arise due to the lack of a particular protein could be treated by this kind of gene therapy.

Over to you

 

 

1. Is DNA effective in identifying persons?

2. Is gene therapy being used to cure diseases? What is its promise for the future of medicine?

3. What some recent developments in gene therapy research do you know?

4. What are the potential benefits of human genome research?

5. Prepare presentations on some recent developments in gene therapy research.

Writing

 

Do you believe that human behavior is determined by our evolution and our genes? Write an essay .

 

 

 

UNIT 5

 

GENETIC ENGINEERING

 

AN OVERVIEW

Vocabulary

 

1. Match the words with their definitions and write the transcription of the words in column 2. Translate the words in column 1 into Russian:

 

1) inovation (n.)		a) a group of products, thoughts, people, etc., appearing at one time or in one season
2) crop (n.)		b) the generation, usually intentional, of mutations
3) breeding (n.)		c) (of machines, methods, etc.) complex and refined •
4) mutagenesis (n.)		d) a result or effect of some previous occurrence
5) insect (n.)		e) to make or become greater in extent, volume, size, or scope; increase
6) sophisticated (adj.)		f) a person or thing that is regarded as dangerous or likely to inflict pain or misery
7) consequence (n.)		g) any small air-breathing arthropod of the class Insecta, having a body divided into head, thorax, and abdomen, three pairs of legs, and (in most species) two pairs of wings.
8) harm (n.)		h) the process of producing plants or animals by sexual reproduction
9) expand (v.)		i) something newly introduced, such as a new method or device

 

 

Listening

 

Decide which experiments should be conducted. Rank these choices from the one you think is the most important (number 1) to the one you think is the least important (number 4) for improving today’s world.

The Plasmid Method

The first technique of genetic engineering, the plasmid method, is the most familiar technique of the three, and is generally used for altering microorganisms such as bacteria. In the plasmid method, a small ring of DNA called a plasmid (generally found in bacteria) is placed in a container with special restriction enzymes that cut the DNA at a certain recognizable sequence. The same enzyme is then used to treat the DNA sequence to be engineered into the bacteria; this procedure creates "sticky ends" that will fuse together if given the opportunity.

Next, the two separate cut-up DNA sequences are introduced into the same container, where the sticky ends allow them to fuse, thus forming a ring of DNA with additional content. New enzymes are added to help cement the new linkages, and the culture is then separated by molecular weight. Those molecules that weigh the most have successfully incorporated the new DNA, and they are to be preserved.

The next step involves adding the newly formed plasmids to a culture of live bacteria with known genomes, some of which will take up the free-floating plasmids and begin to express them. In general, the DNA introduced into the plasmid will include not only instructions for making a protein, but also antibiotic-resistance genes. These resistance genes can then be used to separate the bacteria which have taken up the plasmid from those that have not. The scientist simply adds the appropriate antibiotic, and the survivors are virtually guaranteed (barring spontaneous mutations) to possess the new genes.

Next, the scientist allows the successfully altered bacteria to grow and reproduce. They can now be used in experiments or put to work in industry. Furthermore, the bacteria can be allowed to evolve on their own, with a "selection pressure" provided by the scientist for producing more protein. Because of the power of natural selection, the bacteria produced after many generations will outperform the best of the early generations.

Many people strongly object to the plasmid method of genetic engineering because they fear that when the engineered plasmids are transferred into other bacteria it will cause problems if they express the gene. Lateral gene transfer of this type is indeed quite common in bacteria, but in general the bacteria engineered by this method do not come in contact with natural bacteria except in controlled laboratory conditions. Those bacteria that will be used in the wild - for example, those that could clean up oil spills - are generally released for a specific purpose and in a specific area, and they are carefully supervised by scientists.

The Vector Method

The second method of genetic engineering is called the vector method. It is similar to the plasmid method, but its products are inserted directly into the genome via a viral vector. The preliminary steps are almost exactly the same: cut the viral DNA and the DNA to be inserted with the same enzyme, combine the two DNA sequences, and separate those that fuse successfully. The only major difference is that portions of the viral DNA, such as those that cause its virulence, must first be removed or the organism to be re-engineered would become ill. This does yield an advantage - removal of large portions of the viral genome allows additional "space" in which to insert new genes.

Once the new viral genomes have been created, they will synthesize protein coats and then reproduce. Then the viruses are released into the target organism or a specific cellular subset (for example, they may be released into a bacterium via a bacteriophage, or into human lung cells as is hoped can be done for cystic fibrosis patients). The virus infects the target cells, inserting its genome - with the newly engineered portion - into the genome of the target cell, which then begins to express the new sequence.

With vectors as well, marker genes such as genes for antibiotic resistance are often used, giving scientists the ability to test for successful uptake and expression of the new genes. Once again, the engineered organisms can then be used in experiments or in industry. This technique is also being studied as a possible way to cure genetic diseases.

Many people object to this type of genetic engineering as well, citing the unpredictability of the insertion of the new DNA. This could interfere with existing genes' function. In addition, many people are uncomfortable with the idea of deliberately infecting someone with a virus, even a disabled one.

The Biolistic Method

The biolistic method, also known as the gene-gun method, is a technique that is most commonly used in engineering plants - for example, when trying to add pesticide resistance to a crop. In this technique, pellets of metal (usually tungsten) coated with the desirable DNA are fired at plant cells. Those cells that take up the DNA (again, this is confirmed with a marker gene) are then allowed to grow into new plants, and may also be cloned to produce more genetically identical crop. Though this technique has less finesse than the others, it has proven quite effective in plant engineering.

Objections to this method arise for many of the same reasons: the DNA could be inserted in a working gene, and the newly inserted gene might be transferred to wild plants. Additionally, this technique is commonly opposed because of its association with genetically modified foods, which many people dislike.

Reading Comprehension

 

Read the article carefully and decide if the following statements are true (T), false (F) or not stated (NS). Find in the article the sentences that can prove the true statements and correct the false statements.

1) The widely-spread technique of Genetic Engineering is the vector method.

2) A plasmid is a small ring of DNA.

3) The final step of plasmid method is when the altered bacteria grow and reproduce.

4) The molecules with the least weight have to be preserved after the successful incorporation the new DNA in one of the stages of plasmid method.

5) The plasmid with the introduced DNA includes instructions for making protein but doesn’t’ have antibiotic-resistance genes.

6) The successfully altered bacteria grow, reproduce and used in experiment and industry.

7) There are many objections to plasmid method because of ethical issues.

8) The vector method is entirely different from the plasmid method, but its preliminary steps are similar to the vector method.

9) In accordance with the vector method technique, if certain portions of the viral DNA are not removed from the organism, it will become ill.

10) The vector method has been successfully applied to cure genetic diseases.

11) People are opposed to this method because it can lead to some virus diseases,

 

12) The biolistic method is used in agribusinesses.

13) The biolistic method is supported by many people for many reasons.

 

Language Development

ǃ The Future Tenses

For predictions and general statements about the future will or will be doing are used.

Look at these sentences from the article and underline the future forms of the verb: The next step involves adding the newly formed plasmids to a culture of live bacteria with known genomes, some of which will take up the free-floating plasmids and begin to express them.

In general, the DNA introduced into the plasmid will include not only instructions for making a protein, but also antibiotic-resistance genes.

Remember that will is not normally used in a clause following a time conjunction: when, if, until, before, after, while, provided, as soon as, once, by the time etc

Once the new viral genomes have been created, they will synthesize protein coats and then reproduce.

Many people strongly object to the plasmid method of genetic engineering because they fear that when the engineered plasmids will be transferred into other bacteria it will cause problems if they express the gene.

For more information refer to English Grammar in Use by R.Murphy Un.6, 7, 9

 

1. Complete the sentences with a verb adding will if it is needed.

PROVIDE BECOME BE PERFECTED POLLINATE IMPROVE DEPEND BE BE RESTORED DEVELOP PRACTICE TELL COMPLETE

1. The precise nature of the future society in regards to the look of its members ____________________ on an unpredictable factor - the relative success of different development approaches.

2. It is clear that virtual reality, cyborgisation and genetic engineering all _________ ______________ almost unlimited possibilities for human expression. But which of the three methods ___________ more popular (at certain point) is hard to predict, because it depends on which one will be more advanced, more efficient, safer, cheaper, more available, easier to use, etc

3. Once this research_____________ and scientists understand each step in the life cycle of plants and animals, and once computers _________ powerful enough to simulate the consequences of any changes to DNA, then humans will be able to safely engineer almost any imaginable type of plant or animal.

4. If the tools and techniques __________ and all of the problems associated with food production can be solved, the world environment __________, and our human health and lifestyle ___________ beyond imagination.

5. If super-plants cross ____________ with weeds, will we get super-weeds?

6. If we ___________ super intelligent species or machines that are smarter than human beings, will we be replaced?

7. Only if humanity _______________ practice extremely stringent methods of preventing these technologies from getting out of control, it will be guaranteed a future. Either way, these news reports rightfully predict that these new technologies are the future, unavoidable, somewhat unpredictable, and everyone should heavily invest in the companies researching these technologies to make a small fortune. Only time ___________ who is right.

 

2. Find and learn Russian equivalents for the following words and expressions:

 

1)restriction enzymes	a)
2)to fuse together	b)
3)to weigh	c)
4)free-floating plasmids	d)
5)to possess the new genes	e)
6)to put to work in industry	f)
7)to express the gene	g)
8)lateral gene transfer	h)
9)in the wild	i)
10)to yield an advantage	j)

 

3. Find and learn English equivalents for the following words and expressions:

 

1) cеквенирование ДНК	a)
2) новые соединения	b)
3) молекулярная масса	c)
4) гены, устойчивые к антибиотику	d)
5) возражать	e)
6) исключая спонтанные мутации	f)
7) сталкиваться с	g)
8) вирусная ДНК	h)
9) непредсказуемость	i)
10) быть против, возражать	j)

You are going to listen to the interview with an owner of a restaurant in San Francisco. Before you listen, in groups discuss your answers to the following questions. When you have finished, talk together, compare your answers and try to persuade each other to see your point of view.

- In buying fruits and vegetables, which is more important: taste, texture, color, nutritional value, price, or shelf life? Why?

- Have you ever eaten food that was genetically engineered? What did it look like? What did it taste like?

 

2. Listen to the interview. Find the answers to the following question:

- Is Joyce Goldstein more in favor of or more against genetically engineered food?

3. Read the statements for Part 1. Then listen to Part 1 and decide whether the statements are true or false. Write T or F next to each statement.

Part 1

- Genetically designed tomatoes are now available in the supermarket.

- Genetically engineered sheese can now be purchased.

- World hunger may be halped with genetically engineered food.

- Last week 1000 chefs decided not to serve genetically engineered food.

- Special labeling is required for genetically engineered food.

- Goldstein owns a restaurant in San Francisco.

Part 2

Goldstein believes…

- The genetically engineered tomato is being produced for flavor.

- The use of fish genes in tomatoes is a good idea.

- These foods should ne thoroughly tested and labeled before they are sold.

Part 3

According to Goldstein…

- “progress” os our enemy.

- The methods of the old days were better than those today.

- Genetically bred roses are very beautiful and smell good.