Psoriaskill is being developed for marketing as a topical psoriasis (a skin disorder characterized by peeling, scaling and itching) agent by Oceans of Potions Ltd. To gain FDA approval, Psoriaskill must be tested for skin sensitivity. A consulting company (Svengalilabs Research Institute) is hired to run the skin sensitivity test.TEST DESIGN:
• 90 female rats, 6 months old (equivalent of late teens, early 20s, and concerned about their skin) were selected for the experiment. The rats were divided into 6 dose groups of 100% (F), 50% (E), 25% (D), 10% (C) and 1% (B) of pure Psoriaskill, as well as a control diluent (mineral oil, A).
• A 4 cm by 4 cm patch of each rats’ back was shaved of fur with an electric rotary razor (after the long fur was trimmed) once per week. Psoriaskill, at either one of the 5 test concentrations or the mineral oil diluent was applied to the entire shaved area at a rate of 5 ml/rat/day for 6 days/week. There was not an application of the potion on the day of shaving (the 7th day).
• Applications continued in the above manner for 10 months. The rats were maintained and observed for an additional 10 months (so a total of 20 months for the experiment). Rats were monitored two times/day (at 10:00 am and at 4:00 pm). General comments about food and water consumption, body weight, consistency of waste and overall appearance were noted. No significant changes were noted between dose groups. No rats were deleted from this study.
• At the end of the 20-month period, the rats were carefully observed. All Type 1A skin growths were counted (the data sheet is attached). Note: Type 1A skin growths are hypothetical lesions for purposes of this assignment, not real lesions.
ASSIGNMENT:
As the junior research directors, your job is to interpret the skin growth data. You are writing a report to the Vice-Presidents of Research and Marketing about the dermal toxicity of Psoriaskill and making a recommendation(s) for future research or marketing. Follow standard scientific format for writing your report (introduction, methods, results, discussion/conclusion).
Your report MUST include the following information:
1a) Generate two different dose-response curves to graphically characterize the data. Interpret the data in two different ways (having one graph with a log10 axis and graph with a non-logged axis does not count as two different graphs). Explain briefly what each of the two graphs illustrates (1-2 sentences).
1b) EXCEPTION FOR GROUP OF 3: You will generate 3 different dose-response curves. The third dose response curve will reflect the data for Psoriaskill with the added ingredient Oxybenzone (which is by itself reported to cause some skin irritation effects in sensitive individuals).
2) In your results section, identify:
A) Threshold
B) NOEL and LOEL (both if possible; if not, specify which and why only that metric)
C) Approximate EC (effective concentration) 25, EC50, EC75
3) In your GROUP discussion, interpret/answer the following:
A) Are the values described above (parts 2 A-C) different for your two ways of interpreting the data? Why or why not?
B) Do you recommend continued development of this potion for psoriasis treatment? Why or why not?
4) At the end of the paper, include a break-down of who in the group did what (i.e., Diane wrote the introduction, Alex did the editing, etc.).
Also turn in an individual evaluation form (handed out separately) - it is for you to evaluate yourself and your partner. This will be confidential so BE HONEST. This will help us determine individual grades.
Study # 122376: Psoriaskill Dermal toxicity. Final growth counts, 8-31-19.
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
1A 0 1B 0 1C 0 1D 0 1E 9 1F 10
2A 0 2B 0 2C 5 2D 9 2E 5 2F 9
3A 0 3B 1 3C 0 3D 5 3E 0 3F 7
4A 0 4B 1 4C 5 4D 7 4E 0 4F 12
5A 0 5B 0 5C 0 5D 0 5E 7 5F 4
6A 1 6B 0 6C 6 6D 6 6E 6 6F 25
7A 0 7B 0 7C 0 7D 7 7E 8 7F 2
8A 0 8B 1 8C 1 8D 3 8E 6 8F 9
9A 0 9B 0 9C 0 9D 0 9E 10 9F 8
10A 0 10B 0 10C 7 10D 0 10E 15 10F 10
11A 2 11B 1 11C 9 11D 5 11E 19 11F 7
12A 0 12B 0 12C 0 12D 0 12E 4 12F 12
13A 0 13B 0 13C 0 13D 4 13E 2 13F 15
14A 1 14B 1 14C 0 14D 0 14E 8 14F 14
15A 0 15B 0 15C 3 15D 1 15E 1 15F 9
FOR GROUP OF 3 ONLY: Data for Psoriaskill with added 2% Oxybenzone (a concentration that is considered "safe")
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
ID # # Type 1A Skin Growths
1A 0 1B 0 1C 0 1D 0 1E 10 1F 8
2A 0 2B 0 2C 5 2D 10 2E 5 2F 5
3A 1 3B 0 3C 0 3D 5 3E 0 3F 6
4A 0 4B 1 4C 2 4D 6 4E 0 4F 12
5A 0 5B 0 5C 0 5D 0 5E 4 5F 4
6A 1 6B 1 6C 6 6D 6 6E 6 6F 20
7A 0 7B 0 7C 0 7D 5 7E 8 7F 2
8A 0 8B 1 8C 1 8D 3 8E 6 8F 9
9A 0 9B 0 9C 0 9D 1 9E 10 9F 8
10A 0 10B 0 10C 6 10D 0 10E 14 10F 14
11A 0 11B 1 11C 8 11D 5 11E 18 11F 7
12A 0 12B 0 12C 0 12D 0 12E 4 12F 11
13A 0 13B 0 13C 0 13D 3 13E 2 13F 12
14A 0 14B 0 14C 4 14D 0 14E 8 14F 14
15A 2 15B 0 15C 3 15D 1 15E 1 15F 9