Human Genetic Variation by National Institute of Health - HTML preview

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some relief

________%

some relief

________%

no relief

________%

no relief

________%

Total

154

100%

Total

146

100%

1. Calculate the percentages by dividing the number of children in each cell by the total number of children (154 for girls; 146 for boys).

2. Based on the data above, does sex explain why some children experience no relief from symptoms of asthma after using Drug X? Why or why not?

Table 3. Effect of Exposure to Pet Dander* on Response to Drug X among 300 Children

Response

Number with

Percentage

Response

Number

Percentage

Pets

with Pets

without Pets

signifi cant relief

_______%

signifi cant relief

_______%

some relief

_______%

some relief

_______%

no relief

_______%

no relief

_______%

Total 120

100%

Total 180

100%

* Pet dander is tiny particles of hair, skin, or feathers that can cause an allergic reaction like asthma.

1. Calculate the percentages by dividing the number of children in each cell by the total number of children (120 for those with pets; 180 for those without pets).

2. Based on the data above, does exposure to pet dander explain why some children experience no relief from symptoms of asthma after using Drug X? Why or why not?

Master 3.5b (page 2 of 2)

Report Form for Firm A

Use this form to organize your discussion about Drug X and report your team’s results. You and your teammates will have 30 minutes to complete this form. Be prepared to explain your analysis and proposed solution to the rest of the class.

1. What is the biological problem facing Firm A with respect to Drug X?

2. Describe asthma in your own words (refer to the Team Coordinator and Physiologist handouts).

3. What is Drug X designed to do for asthma sufferers (refer to the Team Coordinator and Physiologist handouts)?

4. Look at the preliminary test results (refer to the Biostatistician handout). Can you predict which group will be helped most or least by Drug X? For example, does the sex of an individual make a difference?

Does having pets make a difference? Explain your answers.

5. What does the example of ApoE (refer to the Molecular Biologist handout) suggest might be happening with Drug X? Based on this example, what might Firm A investigate?

6. Firm A’s vice president for research (your teacher) will provide you with some new data. What do the new data reveal about Drug X?

7. What would be an appropriate way to prescribe Drug X?

8. Has your team solved the biological problem facing the company with respect to Drug X? What new problems has it raised?

Master 3.6

Some New Genetic Data about Firm A

CONFIDENTIAL

Do not discuss or circulate

these data outside Firm A.

Preliminary Results of a Study of 300 Children Treated with Drug X

for Wheezing Associated with Asthma

Number (and percent) of Subjects and Extent of Relief by Genotype

Genotype, as Indicated by Amino Acids*

Signifi cant Relief

Some Relief

Little Relief

arginine/arginine

80 (78%)

20 (16%)

8 (11%)

arginine/glycine

20 (20%)

100 (82%)

24 (35%)

glycine/glycine

2 (2%)

38 (54%)

Total

102

122

* Molecular biologists have determined that a particular protein acts as a receptor for Drug X. Variations in the gene that encodes this receptor protein cause different amino acids to be located at position (number) 16 in the protein. There are two amino acids listed (for example, arginine/arginine) because each person has inherited two genes that encode the receptor protein.

Master 3.7

Saving Firm B, Role:

Team Coordinator

You are an experienced executive for Firm B, a U.S.-based company that develops, tests, manufactures, and distributes pharmaceuticals worldwide. Although you worked in a research lab years ago, your assignments have changed across the years. Now, you head up a small team of scientists that provides expert advice to the much larger teams that actually design, develop, and test new drugs.

You receive an e-mail from Firm B’s vice president for research with a new assignment for your team.

Although one of the company’s major products is still doing very well in the marketplace, the vice president wants to be sure that the company keeps its competitive edge in this area. Because of the importance of this product to the company’s well-being, you decide to call a team meeting for the next day. To prepare for the meeting, you study the relevant section of the e-mail closely.

. . . As you know, Drug Y, a treatment for cystic

fibrosis, is our company’s primary product. . . .

I’d like your team to spend some time identifying

possible new directions we could go in developing new

drugs for the treatment of this disease. Much has been

learned about cystic fibrosis in the last few years.

Does any of this new information suggest some different

approaches we could take to treating the disease?

Ideally, we could develop one or two new drugs that

would supplement, or even one day replace, Drug Y as

our company’s major product.

Master 3.8

Saving Firm B, Role:

Physiologist

You are an experienced physiologist* for Firm B, a U.S.-based company that develops, tests, manufactures, and distributes pharmaceuticals worldwide. You are part of a small team of scientists that provides expert advice to the much larger teams that actually design, develop, and test new drugs.

You have been reading a research report in your office. Now, your assistant calls to say that the leader of your team has called a special team meeting to do some brainstorming about new approaches the company could take in developing drugs for the treatment of cystic fibrosis. You know that Drug Y, your company’s major product, is widely used as a treatment for this disease. Still, a lot has been learned about cystic fibrosis in the last few years. If the company is to maintain its competitive edge, it needs to keep looking for new, more effective treatments. You don’t know much about cystic fibrosis, so you pull out a medical textbook to learn more about it.

Cystic Fibrosis

Cystic fibrosis (CF) is a genetic disease that

affects approximately 30,000 children and

young adults in the United States. CF affects

tissues that produce mucus secretions, such as

the airway, the gastrointestinal tract, and the

ducts of the pancreas. CF causes the body to

produce abnormally thick, sticky mucus that

clogs these passages. The most characteristic

symptom of CF is the excessive production

of mucus in the airways and lungs. This

mucus provides an ideal breeding ground for

many microorganisms, and CF patients have

frequent airway infections that can require

hospitalization and even cause death. Thick

mucus also clogs the pancreatic ducts and

prevents enzymes from the pancreas from

reaching the intestines to help digest food.

People with CF have many symptoms. The

most common are very salty sweat; frequent

coughing, wheezing, and pneumonia; and an

excessive appetite, but poor weight gain and

slowed growth and development.

* A physiologist studies the basic processes of life, such as respiration, digestion, circulation, or cellular metabolism.

Master 3.9

Saving Firm B, Role:

Molecular Biologist

You are an experienced molecular biologist* for Firm B, a U.S.-based company that develops, tests, manufactures, and distributes pharmaceuticals worldwide. You are part of a small team of scientists that provides expert advice to the much larger teams that actually design, develop, and test new drugs.

Your assistant has left you a note. It says that the leader of your team has called a special team meeting to do some brainstorming about new approaches the company could take in developing drugs for the treatment of cystic fibrosis. You know that Drug Y, your company’s major product, is widely used as a treatment for this disease. Still, if the company is to maintain its competitive edge, it needs to keep looking for new, more effective treatments. You decide to find out what the latest research says about CF, and you pick up a recent article.

. . . In 1989, researchers at the

the cell membranes of several

University of Michigan and at

types of cells in the body, where

the Hospital for Sick Children

it acts as a “channel” that opens

in Toronto, Canada, identified

and closes and controls the

the genetic defect responsible

movement of chloride ions out

for CF. Mutations in one

of the cells. Depending on the

gene, called the cystic fibrosis

specific type of CF mutation a

transmembrane conductance

patient has, the CTFR protein

regulator (CFTR), cause the

may be reduced in quantity or

body to make nonfunctional

missing, or it may be present

CFTR protein. The normal

but not work properly . . .

CFTR protein is embedded in

As you read, you develop a flow chart of the biological effects of the most common CF mutation: 1. A person inherits two mutated genes for the CFTR protein.

2. These mutations result in one missing amino acid in the CFTR protein that his or her cells make.

3. The absence of this amino acid means that the CFTR protein in his or her cells does not fold into its proper shape.

4. Most of this improperly folded CFTR protein is destroyed before it can be inserted into

the cell membrane.

5. The absence of properly functioning CFTR protein in the cell membrane leads to

abnormal movement of chloride ions and water in and out of the cell.

6. The result of this abnormal movement of chloride ions and water is the

production of thick, sticky mucus.

* A molecular biologist studies the structure and processes of life at the molecular level. Molecular biologists are interested in such things as the structure and function of proteins and DNA and the molecular mechanisms that regulate activities inside the cell.

Master 3.10

Saving Firm B, Role:

Physician

You are an experienced physician for Firm B, a U.S.-based company that develops, tests, manufactures, and distributes pharmaceuticals worldwide. You are part of a small team of scientists that provides expert advice to the much larger teams that actually design, develop, and test new drugs.

You have been analyzing a new set of test results that one of those larger teams just sent you. Now, your assistant comes into your office to say that the leader of your team has called a special team meeting to do some brainstorming about new approaches the company could take in developing drugs for the treatment of cystic fibrosis (CF). You know that Drug Y, your company’s major product, is widely used as a treatment for this disease. Still, a lot has been learned about CF in the last few years. If the company is to maintain its competitive edge, it needs to keep looking for new, more effective treatments. You decide that you will prepare for the meeting by learning more about Drug Y and also by learning about other companies’ products to treat CF. You pull out some reference material and learn that improvements in treatment across the past few years have increased the average survival time of patients with CF from under 5 years to approximately 30 years. You create a table to help you organize what you learn about these treatments, but leave the last column blank in order to discuss it with your teammates.

Summary of Existing Treatment Approaches for Cystic Fibrosis

Treatment Addresses

Major Type

Description

Primary Benefit

Symptoms or Cause?

chest physical therapy

vigorous tapping on

dislodges mucus from

the back and chest with lungs, allowing better

cupped hands

breathing and reducing

the risk of infection

antibiotics antibiotics

administered

treats lung infections

intravenously, through

that can damage the

pills, or, in the case of

lungs and even cause

Drug Y, as a medicated

death

vapor that is inhaled

enzyme supplements

supplements of

improves digestion

pancreatic enzymes

diet

enriched diet and

reduces malnutrition

supplements of vitamins and improves growth

and other nutrients

and development

Master 3.11

Report Form for Firm B

Use this form to organize your discussion about Drug Y and report your team’s results. You and your teammates will have 30 minutes to complete this form. Be prepared to explain your analysis and proposed solution to the rest of the class.

1. What is the problem facing Firm B with respect to Drug Y (refer to the Team Coordinator handout, Master 3.8)?

2. Describe cystic fibrosis (CF) in your own words (refer to the Physiologist handout, Master 3.9).

3. What have we learned in the past few years about the cause of CF (refer to the Molecular Biologist handout, Master 3.10)?

4. What is Drug Y (and most other current treatments) designed to do for CF patients (refer to the Physician handout, Master 3.11, and discuss what goes in the last column of the table provided)?

5. Firm B’s vice president for research (your teacher) will provide you with some new information. What clue does this new information provide about how Firm B might approach developing new treatments for CF?

6. What new approaches do you recommend Firm B consider as it attempts to design and develop one or more new treatments for CF?

7. Has your team solved the problem facing the company with respect to Drug Y? What new problems has it raised?

Master 3.12

Some New Information about Firm B

INTEROFFICE

M E M O

TO: Team Investigating New Treatment Approaches for Cystic Fibrosis

FROM: Vice President for Research, Firm B

CONFIDENTIAL

Do not discuss or circulate

this memo outside Firm B.

I just heard from a colleague that another research team (not associated with our company)

will apply soon for a patent on a new method for treating cystic fibrosis. These researchers have spent years studying exactly what goes wrong in CF cells. The new method they will propose

involves using small fragments of a protein normally found in brain cells to create working chloride channels in CF cells that lack such channels. Does this offer us any clues about how we might change our treatment approach to CF? Are there any other places in the flow chart of biological effects of CF where we could intervene to correct the problems in CF cells?

Master 3.13

Rolling the Dice

Imagine that you are going to live your entire life—your teen years, your adult years, and your senior-citizen years—in the next 10 minutes and that your choices in life are going to be made by a roll of the dice. Begin with your teen years and roll one die to discover your behavioral choices in each category for each life stage. Use the information provided to determine how many points you receive for each behavior. Record the result in the blanks provided.

By the way, the object of this game is to stay alive to a ripe old age. You do this by keeping your “heart points” below the threshold level of 85. Once you exceed 85 points at any life stage, you’re out (you’ve had a fatal heart attack).

Life Stage 1: Choices as a Teenager

Heart Points

1. Diet. Roll one die. If you rolled:

1 or 2

You eat a well-balanced, low-fat diet (subtract 10 points).

________

3 or 4

You eat some high-fat fast food and junk food (add 5 points).

________

5 or 6

You eat a lot of high-fat fast food and junk food (add 10 points).

________

2. Exercise. Roll the die again. If you rolled:

1 or 2

You’re a couch potato! You get little or no exercise beyond walking from

the TV to the refrigerator (add 15 points).

________

3 or 4

You get a moderate amount of exercise (subtract 5 points).

________

5 or 6

You exercise regularly (subtract 15 points).

________

3. School/Job/Relationships. Roll the die again. If you rolled:

You feel that your life is pretty stress-free (subtract 10 points).

________

You are under a great deal of stress at home, at school, and at work

(add 10 points).

________

For any other rolls, add no points.

________

4. Smoking. Roll the die again. If you rolled:

1 or 2

You don’t smoke and are rarely exposed to those who do (subtract 20 points).

3 or 4

You don’t smoke, but you are around many people who smoke (add 10 points).

5 or 6

You smoke one or more packs of cigarettes a day (add 20 points).

Total risk points from choices made as a teenager: _________

If the total is more than 85, you’ve had a fatal heart attack.

Master 4.1a (page 1 of 3)

Life Stage 2: Choices as an Adult (Ages 20–50 years)

(Start from zero points.)

1. Diet. Roll one die. If you rolled:

1 or 2

You eat a well-balanced, low-fat diet (subtract 10 points).

________

3 or 4

You eat some high-fat fast food and junk food (add 5 points).

________

5 or 6

You eat a lot of high-fat fast food and junk food (add 10 points).

________

2. Exercise. Roll the die again. If you rolled:

1 or 2

You’re a couch potato! You get little or no exercise beyond walking from the

TV to the refrigerator (add 20 points).

________

3 or 4

You get a moderate amount of exercise (subtract 5 points).

________

5 or 6

You exercise regularly (subtract 15 points).

________

3. Job/Relationships. Roll the die again. If you rolled:

You feel that your life is pretty stress-free (subtract 10 points).

________

You are under a great deal of stress at home and at work (add 10 points).

________

For any other rolls, add no points.

4. Smoking. Roll the die again. If you rolled:

1 or 2

You started smoking during your teen years* (add 20 points).

You did not start smoking during your teen years (add no points).

________

3 or 4

You smoked during your teen years, but you have stopped smoking*

(subtract 20 points).

________

You did not smoke during your teen years (subtract 5 points).

________

5 or 6

You smoke one or more packs of cigarettes a day (add 20 points).

________

Total risk points from choices made as an adult: _________

Total risk points from choices made as a teenager: _________

Total points: _________

If the total is more than 85, you’ve had a fatal heart attack.

* Be sure to check your record on Master 4.1a.

Master 4.1b (page 2 of 3)

Life Stage 3: Choices as a Senior Citizen (Over Age 50 years)

(Start from zero points.)

1. Diet. Roll one die. If you rolled:

1 or 2

You eat a well-balanced, low-fat diet (subtract 10 points).

________

3 or 4

You eat some high-fat fast food and junk food (add 5 points).

________

5 or 6

You eat a lot of high-fat fast food and junk food (add 10 points).

________

2. Exercise. Roll the die again. If you rolled:

1 or 2

You’re a couch potato! You get little or no exercise beyond walking

from the TV to the refrigerator (add 20 points).

________

3 or 4

You get a moderate amount of exercise (subtract 5 points).

________

5 or 6

Human Genetic Variation by National Institute of Health - HTML preview

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