V04-10, V04-11, V04-12, V04-13

Question

Although the class of anti-inflammatory drugs known as COX-2 inhibitors has proven successful at reducing pain and swelling, a series of clinical trials has shown that these drugs come with potentially harmful side effects. Anti-inflammatory drugs act on prostaglandins, hormone-like substances with a general regulatory role in the body – controlling blood flow to the kidneys or prompting contraction of the uterus during childbirth, for example – in addition to bearing the primary responsibility for causing pain and inflammation. Prostaglandins are the result of a process by which a type of acid in the cell membrane is transformed by two enzymes both known as cyclooxygenase, or COX-1 and COX-2. Older anti-inflammatory medications such as aspirin and ibuprofen stop pain by blocking the action of both COX enzymes. Researchers have long been aware, however, that the simultaneous repression of both COX-1 and COX-2 halts production of  all  prostaglandins, including those not responsible for pain.
 
Researchers who developed COX-2 inhibitors hoped to avoid negative side effects by blocking only one of the two COX enzymes. After a series of trials, drugs such as Vioxx and Celebrex entered the market in the 1990s. This approach, unfortunately, soon presented its own drawbacks. Although COX-2 inhibitors do in fact prevent production of prostaglandin E2 (PGE2), which is responsible for causing pain and inflammation, they also inhibit production of various other substances in the body, including prostacyclin (PGI2), which dilates blood vessels and prevents clots. On the other hand, COX-2 inhibitors do  not  prevent the production of thromboxane, another prostaglandin that constricts vessels and helps blood platelets clump. There is widespread agreement that the next step for researchers is to develop anti-inflammatory drugs that target specific prostaglandins rather than the enzymes that produce them.  1. Which of the following best describes the organization of the passage?

(a) Two options for anti-inflammatory drugs are compared.
(b) The history of a type of medication is outlined.
(c) The function of and problems with a type of medication are presented.
(d) The usefulness of a popular prescription is debated.
(e) New information is used to undermine old assumptions.
 C

2. 
According to the passage, a problem with COX-2 inhibitors arises for which of the following reasons?
 
COX-2 inhibitors

(a) often conflict with older types of anti-inflammatory medication.
(b) cause the production of an excessive amount of prostaglandin E2.
(c) do not suppress an excessive amount of thromboxane, which causes blood clots.
(d) do not account for the complexity of prostaglandin function.
(e) block the production of necessary regulatory substances.
 E

3. Based on information in the passage, which of the following can be concluded about the function of the substance thromboxane?

(a) Thromboxane is responsible for several types of circulatory disorder.
(b) Prostaglandins are made in different cells than thromboxane.
(c) Aspirin does not affect the production of thromboxane.
(d) Thromboxane balances the effects of PGI2.
(e) Thromboxane plays an undetermined role in regulating inflammation.
 D

4. It can be concluded from the passage that COX-2 inhibitors are in danger of accidentally disrupting which of the following bodily processes?

(a) constriction of blood vessels
(b) inflammation
(c) cell division
(d) kidney function
(e) enzyme production
 D

Bunuel · Answer

In order to answer this question, analyze the structure of the passage. The first sentence of the passage introduces the topic of COX-2 inhibitors, paragraph 1 discusses their function, and paragraph 2 presents more detailed information about the problems they present. The organization of the passage is intended to discuss function and problems with COX-2 inhibitors.   Two options are not compared. 
 Although historical information is given, the purpose of the passage is not to discuss history. 
 Problems of COX-2 inhibitors are discussed in the first sentence and second paragraph, and general function of COX-1 inhibitors is overviewed in paragraph 1. 
 Popular prescriptions Vioxx and Celebrex are mentioned only in the second paragraph. 
 None of the information in the passage is presented as new.     The phrase  according to the passage  in the question stem is a signal that this question can be answered using specific details from the passage. In order to answer the question, review significant lines or sentences in the paragraph to determine which is accurate. The correct answer will be a paraphrase of information stated in the passage.   The interaction of COX-2 inhibitors with other anti-inflammatory medications is not discussed in the passage. 
 Actually, COX-2 inhibitors successfully  block  production of this substance. See here. 
 Though this is true, the larger problem with COX-2 inhibitors is that they  do  block the substance that keeps thromboxane in balance. 
 This is a distortion of details from the passage. 
 The passage states that COX-2 inhibitors block the production of PGI2, which  dilates vessels and prevents clots .     An inference drawn from specific details from the passage will be necessary to answering this question. To begin, review what is stated in the passage about thromboxane in the second paragraph, as well as in sentences surrounding the thromboxane reference. The lines state that thromboxane and PGI2 have opposite effects on the cardiovascular system. It can be concluded, then, that their functions balance each other.   Circulatory disorders are not discussed in the passage. 
 The passage does not discuss the location of the production of substances. Additionally, the passage states that thromboxane is a  type  of prostaglandin. 
 Aspirin’s affect on the production of thromboxane is not discussed in the passage. 
 According to the passage, thromboxane  constricts vessels and helps blood platelets clump , while PGI2 dilates blood vessels and prevents clots . 
 On the contrary, the passage contains information about the exact functioning of thromboxane.     The answer to this question depends on making an inference. More specifically, the question requires the connection of information in the first and third paragraphs. It is stated in the first paragraph that prostaglandins regulate certain healthy functions, such as blood flow to the kidneys. In the second paragraph it is stated that COX-2 inhibitors disrupt the production of various prostaglandins, which could reasonably include those that control kidney function.    These lines state that COX-2 inhibitors do  not  block thromboxane, which constricts blood vessels. 
 COX-2 inhibitors are anti-inflammatories intended to disrupt inflammation. 
 Cells are mentioned in the passage, but not cell division. 
 Since this line states that prostaglandins regulate blood flow to the kidneys and this line states that COX-2 inhibitors interrupt the production of various prostaglandins, it can reasonably be concluded that COX-2 inhibitors could disrupt kidney function. 
 COX-2 inhibitors deliberately interrupt the function of COX enzymes, but their  production  is not discussed in the passage.

TudorM · Answer

I got tricked (and I partly do not agree with some of the responses/explanations)

- by the V04-11 question because:

For answer E, the correct one, the text states "also drastically reduce the amount of various other substances in the body, including prostacyclin (PGI2)," - So drastically reduce BUT NOT BLOCK - Should we actually infer that drastically reduce = block? (I have not seen this before)

While C is supported by the text: "do not prevent the production of thromboxane, another prostaglandin that constricts vessels and helps blood platelets clump." it is considered by the response key as "less larger problem" - How do we account for that?

- by question V04-12 because:

I did not manage to infer that the effects of the 2 substances balance. While I can agree that "It can be concluded, then, that their functions balance each other.", but is it safe to infer that their effects balance as well? (Since we don't know the quantities, how can we infer that the effects balance? In the V04-11 we considered that one is less important than other, then can we safely say that they balance?)

- and by question V04-13 because:

I think we can equally infer that COX-2 can accidentally disrupt constriction of blood vessels for the reason: "COX-2 inhibitors do not prevent the production of thromboxane, another prostaglandin that constricts vessels and helps blood platelets clump". Since the inhibitors do not prevent the production of thromoxane, then the inhibitors permit the the constriction of blood vessels, right?

Thanks for clarifying!

RahulSingh13 · Answer

I think this is a  poor-quality  question and I don't agree with the explanation. Isn't blocking the production and reducing the amount, as stated in the passage, two different implications?

RahulSingh13 · Answer

My previous feedback came across too critical. I blame the auto-select options :/ I don't have a problem with the quality of the question. It's a great question. I just don't agree with the correct answer choice and it's explanation.

manlog · Answer

V04-11: I don't agree with the explanation and the correct answer choice. "Reduce amount" doesn't mean block. The could for instance, make a chemical reaction and thus reduce the concentration, and not block anything at all.

V04-11: Thank you for the observation. The text has been modified accordingly.

V04-14:   I don't agree with the explanation and the correct answer choice as well. The first passage talks that  prostaglandins in general  control blood flow and so on. Then it's said that COX-2 blocks only specific prostaglandin E2, that is related to blood vessels. Though one can conclude that if prostaglandins in general have affect on the kidneys, then E2, since it is a prostaglandin, also has this effect, the description of COX-2 clearly gives an info that different prostaglandins have  different  individual features. Thus we can't conclude that E2 despite being a prostaglandin could cause problems with kidneys.

sayantanc2k · Answer

V04-11: Thank you for the observation. The text has been modified accordingly.

V04-13: It is true that different prostaglandins have  different  individual features. Nonetheless at least two of those features are common for ALL prostaglandins - "controlling blood flow to the kidneys or prompting contraction of the uterus during childbirth" as you have already noticed in the first paragraph.

apple08 · Answer

Dear Expert,
for option C, how can I know the popular prescription refers to Vioxx and Celebrex? when I attempted the question, I thought COX-2 inhbitors is popular based on my understanding of this sentence "Although the class of anti-inflammatory drugs known as COX-2 inhibitors has proven successful..."
Hope to hear from you. Many thanks

sayantanc2k · Answer

I am not clear about your query. Which question are you referring to?

Heisenberg12 · Answer

In explanation for V-04 11, option C has been discarded on account of a larger problem that the given option doesn't cater to. I have two queries. How to decide whether something mentioned in the option has a larger significance? The fact that it has been specified in the passage makes it significant. Regarding option E, it is more of an inference than specification from the passage. However, the question stem states we need to find something indicated in the passage. Option C could be called true in the sense that COX-2 inhibits PGI2 production, thus making the vessels more prone to blood clots. Additionally, COX-2, by not preventing the production of thromboxane increases the possibility of blood clots since the same constricts vessels. Thus, the problem of probable blood clots increases two-fold with COX-2 inhibitors.

apple08 · Answer

Dear Expert,

im sorry, im referring to question 1. Hope to hear from you.

Many thanks

chessgiants · Answer

well, I hope the question is placed following the flow of the passage. In other words, if you look at other parts of the passage, you can see how the drugs affect the body, and other organs. In the end, after skimming through the passage, the readers only recall the big pictures, not the right detail to deduct the any information.

Sassie · Answer

I do not agree with the explanation. Opposing effects are not necessarily balancing each other out.

Sassie · Answer

I do not agree with the explanation. Opposing effects are not necessarily balancing each other out. FUrthermore, bloodvessel constriction can most definitely be a circulatory disorder. (I'm a doctor)

rafa rakesh · Answer

i too have the same doubt.Can anyone please clarify

peterpete · Answer

I think this is a  poor-quality  question and the explanation isn't clear enough, please elaborate.

CHANDRA080252 · Answer

nice question.

Tanisha_shasha · Answer

For question V04-11 have you used the lines in para 1 to infer that  COX-2 inhibitors block the production of necessary  regulatory  substances . I ended up choosing option C, i somehow couldn't agree with the explanation provided.

The passage clearly states that  "COX-2 inhibitors do not prevent the production of thromboxane, another prostaglandin that constricts vessels and helps blood platelets clump. " hence i chose the answer whose language connected "do not suppress an excessive amount of thromboxane, which causes blood clots."
Please help me bridge the gap in my understanding

Thank you

AdityaHongunti · Answer

C. Aspirin does not affect the production of thromboxane.

passage : Older anti-inflammatory medications such as  aspirin  and ibuprofen stop pain by blocking the action of  both  COX enzymes. 
   COX-2  inhibitors  do not   prevent the production of thromboxane ,

2+2 = Aspirin does not affect(does not prevent) . If COX2 inhibitirs do not prevent then aspirin doesnt too because aspirin inhibits the action of COX1 AND COX2. 
please explain

aryarkrishnan · Answer

This is what i thought too.. It would be nice if someone can post what aspect we are missing here.

V04-10, V04-11, V04-12, V04-13

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards