SomeInfo First…

MID-TERM REVISION

Let’s talk about theExam first…..

THE EXAM

-March 4th, 2003, from 10h05am to 11h25am

-Multiple choices 11 questions worth 1 point each : 11 points 1 question worth 3 points : 3 points

TOTAL : 14 points

-Essay Questions 1 obligatory question 4 points Choice of 2 questions (3.5 each) 7 points

TOTAL 11 points

TOTAL 25 points

For many years, a significant number of men and women considered Marilyn Monroe as being the best representative of feminine characteristics (breasts, hips etc.). What were people implicitly doing while considering Marilyn Monroe as such?

MULTIPLE CHOICE : EXAMPLE

A) A behavioral bioassayB) A bioassayC) A metabolite assayD) A radioimmunoassay

MULTIPLE CHOICE : EXAMPLE

Mary is brought to the hospital by her mother because she has been feeling very depressed lately and shows signs of truncal obesity. At the hospital, doctors suspect that Mary is suffering from Cushing’s Disease. What methodological protocol can they use in order to evaluate rapidly if Mary is suffering from a hypersecretion of cortisol ?

A) Measure cortisol levels for 24hr, one sample every hour, many days in the month.

B) Use a pharmacological challenge such as the dexamethasone suppression test (DST test) in order to evaluate the feedback activity of her hypothalamic-pituitary-adrenal axis.

C) Use a pharmacological protocol in which metyrapone (inhibitor of cortisol secretion) will be administered as a treatment in order to assess whether lowering cortisol levels will alleviate her symptoms.

D) A and B are trueE) A and C are true

You inject 50mg testosterone in 10 young female and 10 young male participants. In a baseline blood sample taken before the injection, you observed that the testosterone level in males was 12mg while the testosterone level in females was 7mg. Five minutes after the injection of the 50mg dose of testosterone in both groups, you take another blood sample. What should you observe in each group?

A) A similar increase in circulating levels of testosterone in both groupsB) A larger increase of testosterone levels in malesC) A testosterone-induced increase in estrogen levels in both groupsD) A and C are true

MULTIPLE CHOICE : EXAMPLE

Let’s say you suffer from a very rare disease that does not allow your body to possess any carrier proteins. You decide to enter an experiment measuring the impact of exogenous administration of synthetic estrogen on anxiety level. The hypothesis is that high estrogen levels significantly increase anxiety level (PMS). The scientist injects a dose of 30 mg synthetic estrogen to you (this drug has been shown to cross the blood-brain barrier in previous experiments), and to another participant who possesses normal levels of carrier proteins. Starting 5 minutes later and going further in time, what will be the major differences between your response to treatment, and that of the other participant? (This question is worth 3.5 points).

Given that it is the free bound fraction of the steroid (in this case, estrogen) that can cross the blood-brain barrier, there will be more estrogen getting to your brain after administration of the synthetic estrogen than for the other subject. So, we will see very fast effect of the estrogen on anxiety 1 point

However, once in the circulation the steroid has to be bound to a carrier protein in order not to be degraded by enzymes while in circulation, so there is also a higher probability that the dose injected to you will be degraded faster than for the other participants, thus leading to faster degradation of estrogen by enzymes in your case compared to the other subject, thus leading to a shorter half-life 1.5 points . Net effect : In your case, a very fast action of estrogen on anxiety, but that will not last long. In the case of the other subject, it will be the reverse. It will take longer to see effects of estrogen on anxiety, but these effects will last longer 1 point.

ANSWER KEY