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Naturaleza del diseño.

Understanding the biology of adipocytes is important to the progress of lipolysis techniques and the possible usage of adipocytes as stem cells. In addition, various methods for fat removal are being investigated, including drugs or chemicals that can stimulate lipoly- sis (e.g., phosphatedylcholine, isopro- terenal, theophylline, aminophylline, caffeine, carnitine, carbon dioxide, and herbal extracts) and device-assisted liposuction such as ultrasound (to burst fat cells) or 1064 nm Nd:YAG laser (to melt the fat cell). These new methods need to be evaluated for safety and efficacy.

SUMMARY

Adipocytes and subcutaneous tissue are important subjects to which the

BOX 3-2 Hexsel Classification of Cellulitea

• At Stage 0, the skin’s surface is not altered. • At Stage I, skin is smooth when the indi-

vidual is standing or lying down, but some cellulite appears if the skin is pinched. • At Stage II, skin appears dimpled without

any pinching or manipulation. • At Stage III, skin appears both dimpled

and raised in some areas.

aPersonal communication with Doris Hexsel,

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cosmetic dermatologist should pay attention. There are cosmetic concerns related to both excess and loss of fat for which the patient will seek cos- metic intervention. Advances in this field will be centered on more directed therapies of fat removal or disruption in heavy patients and on stem cell purification and injection in thinner patients. It is the role of the cosmetic dermatologist to remain abreast of these changes. Furthermore, cosmetic dermatologists and surgeons should take an active role in counseling patients on proper nutrition and weight management from both extremes (too thin or too heavy).

REFERENCES

1. Hausman DB, DiGirolamo M, Bartness TJ, et al. The biology of white adipocyte

proliferation. Obes Rev. 2001;2:239.

2. Avram MM, Avram AS, James WD. Subcutaneous fat in normal and diseased

states: 1. Introduction. J Am Acad Dermatol.

2005;53:663.

3. Bélanger C, Hould FS, Lebel S, et al. Omental and subcutaneous adipose tis-

sue steroid levels in obese men. Steroids.

2006;71:674.

4. Wang B, Han J, Gao Y, et al. The differen- tiation of rat adipose-derived stem cells into OEC-like cells on collagen scaffolds

by co-culturing with OECs. Neurosci Lett.

2007;421:191.

5. Avram MM, Avram AS, James WD. Subcutaneous fat in normal and diseased states 3. Adipogenesis: from stem cell to

fat cell. J Am Acad Dermatol. 2007;56:

472.

6. Prins JB, O’Rahilly S. Regulation of adi-

pose cell number in man. Clin Sci.

1997;92:3.

7. Faust IM, Miller HM Jr. Hyperplastic growth of adipose tissue in obesity. In: Angel A, Hollenberg CH, Roncari DAK,

eds. The Adipocyte and Obesity: Cellular

and Molecular Mechanisms. New York, NY: Raven Press; 1983:41-51.

8. Spiegelman BM, Flier JS. Adipogenesis and obesity: rounding out the big picture. Cell. 1996;87:377.

9. Manson JE, Bassuk SS. Obesity in the United States: a fresh look at its high toll.

JAMA. 2003;289:229.

10. Kuczmarski RJ, Flegal KM, Campbell SM, et al. Increasing prevalence of over- weight among US adults. The National Health and Nutrition Examination

Surveys, 1960–1991. JAMA. 1994;272:

205.

11. Friedman JM, Halaas JL. Leptin and the regulation of body weight in mammals. Nature. 1998;395:763.

12. Montague CT, Farooqi IS, Whitehead JP, et al. Congenital leptin deficiency is asso- ciated with severe early-onset obesity in

humans. Nature. 1997;387:903.

13. Krude H, Biebermann H, Schnabel D, et al. Obesity due to proopiomelano- cortin deficiency: three new cases and treatment trials with thyroid hormone

and ACTH4–10. J Clin Endocrinol Metab.

2003;88:4633.

14. Löffler H, Aramaki JU, Effendy I. The influence of body mass index on skin susceptibility to sodium lauryl sulphate. Skin Res Technol. 2002;8:19.

15. Deplewski D, Rosenfield RL. Growth hormone and insulin-like growth factors have different effects on sebaceous cell

growth and differentiation. Endocrinology.

1999;140:4089.

16. Cappel M, Mauger D, Thiboutot D. Correlation between serum levels of insulin-like growth factor 1, dehy- droepiandrosterone sulfate, and dihy- drotestosterone and acne lesion counts in

adult women. Arch Dermatol. 2005;141:

333.

17. Goodson WH III, Hunt TK. Wound colla- gen accumulation in obese hyper-

glycemic mice. Diabetes. 1986;35:491.

18. de Jongh RT, Serné EH, IJzerman RG, et al. Impaired microvascular function in obesity: implications for obesity- associated microangiopathy, hyperten-

sion, and insulin resistance. Circulation.

2004;109:2529.

19. Garcia-Hidalgo L. Dermatological com-

plications of obesity. Am J Clin Dermatol.

2002;3:497.

20. Pribanich S, Simpson FG, Held B, et al. Low-dose tretinoin does not improve striae distensae: a double-blind, placebo-

controlled study. Cutis. 1994;54:121.

21. Hernández-Pérez E, Colombo-Charrier E, Valencia-Ibiett E. Intense pulsed light in the treatment of striae distensae. Dermatol Surg. 2002;28:1124.

22. Jiménez GP, Flores F, Berman B, et al. Treatment of striae rubra and striae alba with the 585-nm pulsed-dye laser. Dermatol Surg. 2003;29:362.

23. Goldberg DJ, Sarradet D, Hussain M. 308-nm Excimer laser treatment of

mature hypopigmented striae. Dermatol

Surg. 2003;29:596.

24. Yosipovitch G, DeVore A, Dawn A. Obesity and the skin: skin physiology

and skin manifestations of obesity. J Am

Acad Dermatol. 2007;56:901.

25. Lemonnier D. Effect of age, sex, and sites on the cellularity of the adipose tissue in mice and rats rendered obese by a high-

fat diet. J Clin Invest. 1972;51:2907.

26. Faust IM, Johnson PR, Stern JS, et al. Diet-induced adipocyte number increase

in adult rats: a new model of obesity. Am

J Physiol. 235:E279, 1978.

27. Coleman WP IV, Hendry SL II. Principles

of liposuction. Semin Cutan Med Surg.

2006;25:138.

28. Svedman KJ, Coldiron B, Coleman WP III, et al. ASDS guidelines of care for

tumescent liposuction. Dermatol Surg.

2006;32:709.

29. Coleman WP III, Glogau RG, Klein JA, et al. Guidelines of care for liposuction. J Am Acad Dermatol. 2001;45:438. 30. Dolsky RL. State of the art in liposuction.

Dermatol Surg. 1997;23:1192.

31. Giese SY, Bulan EJ, Commons GW, et al. Improvements in cardiovascular risk pro- file with large volume liposuction: a pilot

study. Plast Reconstr Surg. 2001;108:

510.

32. Klein S, Fontana L, Young VL, et al. Absence of an effect of liposuction on insulin action and risk factors for coro-

nary heart disease. N Engl J Med.

2004;350:2549.

33. Giugliano G, Nicoletti G, Grella E, et al. Effect of liposuction on insulin resistance and vascular inflammatory markers in

obese women. Br J Plast Surg. 2004;57:

190.

34. Pessa JE, Zadoo VP, Mutimer KL, et al. Relative maxillary retrusion as a natural consequence of aging: combining skele- tal and soft-tissue changes into an inte-

grated model of midfacial aging. Plast

Reconstr Surg. 1998;102:205.

35. Obagi S. Autologous fat augmentation: a perfect fit in new and emerging technolo-

gies. Facial Plast Surg Clin North Am.

2007;15:221.

36. Gosain AK, Amarante MT, Hyde JS, et al. A dynamic analysis of changes in the nasolabial fold using magnetic reso- nance imaging: implications for facial rejuvenation and facial animation

surgery. Plast Reconstr Surg. 1996;98:

622.

37. Rohrich RJ, Pessa JE. The fat compart- ments of the face: anatomy and clinical

implications for cosmetic surgery. Plast

Reconstr Surg. 2007;119:2219.

38. Donofrio LM. Fat distribution: a mor-

phologic study of the aging face. Dermatol

Surg. 2000;26:1107.

39. Coleman SR. Concepts of aging: rethink- ing the obvious. In: Structural Fat Grafting. St. Louis, MO: Quality Medical Publishing; 2004:xvii-xxiv.

40. Kranendonk S, Obagi S. Autologous fat transfer for periorbital rejuvenation: indi- cations, technique, and complications. Dermatol Surg. 2007;33:572.

41. Narins RS. Fat transfer with fresh and frozen fat, microlipoinjection, and lipocytic dermal augmentation. In: Klein AW, ed. Tissue Augmentation in Clinical Practice. 2nd ed. New York, NY: Taylor and Francis; 2006:1-19.

42. Eremia S, Newman N. Long-term follow- up after autologous fat grafting: analysis of results from 116 patients followed at least 12 months after receiving the last of

a minimum of two treatments. Dermatol

Surg. 2000;26:1150.

43. Sommer B, Sattler G. Current concepts of fat graft survival: histology of aspirated adipose tissue and review of the litera-

ture. Dermatol Surg. 2000;26:1159.

44. Egido JA, Arroyo R, Marcos A, et al. Middle cerebral artery embolism and unilateral visual loss after autologous fat

injection into the glabellar area. Stroke.

1993;24:615.

45. Teimourian B. Blindness following fat

injections. Plast Reconstr Surg. 1988;82:361.

46. Dreizen NG, Framm L. Sudden visual loss after autologous fat injection into the

glabellar area. Am J Ophthalmol. 1989;107:

85.

47. Danesh-Meyer HV, Savino PJ, Sergott RC. Case reports and small case series: ocular and cerebral ischemia following

facial injection of autologous fat. Arch

Ophthalmol. 2001;119:777.

48. Pinski KS, Coleman WP III. Micro- lipoinjection and autologous collagen. Dermatol Clin. 1995;13:339.

49. Strem BM, Hicok KC, Zhu M, et al. Multipotential differentiation of adipose

tissue-derived stem cells. Keio J Med.

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50. Mizuno H, Zuk PA, Zhu M, et al. Myogenic differentiation by human

processed lipoaspirate cells. Plast Reconstr

Surg. 2002;109:199.

51. De Ugarte DA, Morizono K, Elbarbary A, et al. Comparison of multi-lineage cells from human adipose tissue and bone mar-

row. Cells Tissues Organs. 2003;174:

101.

52. Kokai LE, Rubin JP, Marra KG. The potential of adipose-derived adult stem cells as a source of neuronal progenitor

cells. Plast Reconstr Surg. 2005;116:1453.

53. Draelos ZD, Marenus KD. Cellulite. Etiology and purported treatment. Dermatol Surg. 1997;23:1177.

54. Draelos ZD. The disease of cellulite. J

Cosmet Dermatol. 2005;4:221.

55. Piérard GE. Cellulite: from standing fat herniation to hypodermal stretch marks. Am J Dermatopathol. 2000;22:34. 56. Alexiades-Armenakas M. Laser and light-

based treatment of cellulite. J Drugs

Dermatol. 2007;6:83.

57. Hexsel DM, Mazzuco R. Subcision: a

treatment for cellulite. Int J Dermatol.

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C H A P T E R 4

Immunology of

the Skin

H. Ray Jalian, MD

Jenny Kim, MD, PhD

response, on the other hand, occurs slowly and activation of adaptive immune cells, such as B and T cells, requires that receptors undergo gene rearrangements. The adaptive immune system can mount either humoral immunity (B cells, which make antibod- ies) or cell-mediated immunity (T cells). Furthermore, the adaptive immune sys- tem is also responsible for immune memory, which confers long-term pro- tection to the host. Although the two systems appear distinct, they are not separate, and in fact can act synergisti- cally, insofar as the innate immune sys- tem instructs the adaptive immune response and the adaptive immune sys- tem influences the innate system.

In the epidermis, the two main innate cells are the keratinocytes and Langerhans cells. In addition, neutrophils, macro- phages, and dendritic cells present within the dermis also play a role in innate immunity. When a foreign substance is encountered, activation of innate cells occurs through PRRs, including the Toll- like receptors (TLRs), which are reviewed below. Upon activation, the innate cells become capable of inducing a direct antimicrobial response by producing fac- tors that can help protect the host from external insults. These factors include reactive oxygen and nitrogen intermedi- ates (also known as “free radicals”) and antimicrobial peptides. In addition, acti-

vated innate cells produce cytokines and other inflammatory mediators that can instruct adaptive immunity. Paradoxically, the same innate immune response can induce proinflammatory cytokine pro- duction that can lead to inflammation and tissue injury, thereby facilitating dis- ease pathology.