Gan DC, Sinclair RD
J Investig Dermatol Symp Proc10p184-9(2005 Dec)
In search of the “hair cycle clock”: a guided tour
PAUS Ralf ; FOITZIK Kerstin ; Résumé / Abstract The hair follicle, a unique characteristic of mammals, represents a stem cell-rich, prototypic neuroectodermal-mesodermal interaction system. This factory for pigmented epithelial fibers is unique in that it is the only organ in the mammalian body which, for its entire lifetime, undergoes cyclic transformations from stages of rapid growth (anagen) to apoptosis-driven regression (catagen) and back to anagen, via an interspersed period of relative quiescence (telogen). While it is undisputed that the biological “clock” that drives hair follicle cycling resides in the hair follicle itself, the molecular nature of the underlying oscillator system remains to be clarified. To meet this challenge is of profound general interest, since numerous key problems of modern biology can be studied exemplarily in this versatile model system. It is also clinically important, since the vast majority of patients with hair growth disorders suffers from an undesired alteration of hair follicle cycling. Here, we sketch basic background information and key concepts that one needs to keep in mind when exploring the enigmatic “hair cycle clock”(HCC), and summarize competing models of the HCC. We invite the reader on a very subjective guided tour, which focuses on our own trials, errors, and findings toward the distant goal of unravelling one of the most fascinating mysteries of biology: Why does the hair follicle cycle at all? How does it do it? What are the key players in the underlying molecular controls? Attempting to offer at least some meaningful answers, we share our prejudices and perspectives, and define crucial open questions. Revue / Journal Title Differentiation ISSN 0301-4681 Source / Source 2004, vol. 72, no9-10, pp. 489-511 [23 page(s) (article)] Langue / Language
Prevalence of male and female pattern hair loss in Maryborough.
Gan DC, Sinclair RD. Department of Dermatology, University of Melbourne, St Vincent's Hospital, Melbourne, Victoria, Australia. Maryborough, in central Victoria has an approximate population of 8000 and census data is well matched for Australia overall. Australia has compulsory voting and registration on the electoral roll. To determine the age-related prevalence of balding among men and women in Maryborough we conducted a postal survey of 5000 men and women aged 20 or older, and 427 were invited to attend for examination. Additional data was collected on dandruff, presence of gray hair. Supplementary questionnaires were sent to 340 children aged 5-9, attending a coeducational primary school. 1456 adults (34.1%) responded to the questionnaire. 396 attended for examination. The prevalence of androgenetic alopecia (AGA) increased with advancing age. 98.6% of men had bitemporal recession and severity was significantly associated with vertex and mid-frontal hair loss (p <0.01) but not age (p = 0.06). In all, 64.4% of women had bitemporal hair loss, and similar to men there was a significant association with mid-frontal hair loss (p =0.042) but not age (p =0.467). One hundred and forty children with completed questionnaires were examined. All 72 females and 68 males were assessed as stage 1 on the mid-line part and with no bitemporal recession (frequency stage 1 = 100%, 95% CI (confidence interval) 97.4%-100%). A significant but weak positive association existed between presence of gray hair and history of dandruff (p<0.01). The prevalence of mid-frontal hair loss increases with age and affects 57% of women and 73.5% of men aged 80 and over. 1)
“Vertex baldness, but not frontal baldness, is associated with an increased risk of CHD. The association with CHD depends on the severity of vertex baldness and also exists among younger men”2)
From: mvanwink5 Date: 2011-10-20 05:47:33 Reply: http://www.marshallprotocol.com/reply.php?topic_id=10978
When I went to California last month, one of my friends pointed out that I was showing hair growth on top of my head. At first I thought he was joking, but he assured me that he was not. Frankly, I was not convinced, but this month I am not so sure as it does appear to be more up top, there. At this rate I'll give it a couple or more years before I look for a comb. :cool:
From: leroybrown Date: 2011-10-20 07:35:57 Reply: http://www.marshallprotocol.com/reply.php?topic_id=10978
I hope that happens to my hubby, now that he's on the MP too!
From: Paisleykilt Date: 2011-10-20 08:16:09 Reply: http://www.marshallprotocol.com/reply.php?topic_id=10978
My hair has definitely become both thicker and darker again; the downside is that my legs are hairier again, too! :shock:
Ah well, that'll keep me toasty warm in the winter… :P
From: JudyBeauty Date: 2011-10-20 16:10:14 Reply: http://www.marshallprotocol.com/reply.php?topic_id=10978
When I started the MP I noticed that the hair on my legs and arms stopped growing so I don't have to shave my legs anymore and the hair on my head stopped falling out so I don't shed much hair on my head.
I will be 59 this November and I don't have grey hair and did not have grey hair before the MP. My mother started to get some white hairs in her late 70's but then her hair went back to it's normal color and when she died at 85 she didn't have any grey or white hair. The health care worker that was helping to take care of her the last year and half of her life thought we were dying her hair. My mother's father and mother did not have grey hair when they died (one at 63 and the other at 68).
My Dad didn't start to go grey till his 80's. He was so proud of his hair. All the older men he knew accused him of dying his hair. All of my dad's brothers and sisters went grey and eventually white haired. Not my Dad. Why? Is it just a coincidence that my Dad's entire family went grey and white (he had 9 siblings) and he didn't? Was it just a coincidence that his wife was not grey or white haired?
I would love to know more about why people go grey but there is not to much information on the internet about it.
Are there any other MP'ers around my age that aren't turning grey?
Br J Vener Dis. 1977 Dec;53(6):389-90.Syphilitic alopecia and Jarisch-Herxheimer reaction. Pareek SS. 3)
Alopecia syphilitica with detection of Treponema pallidum in the hair follicle. Nam-Cha SH, Guhl G, Fernández-Peña P, Fraga J. J Cutan Pathol. 2007 Dec;34 Suppl 1:37-40. 4)
2: Cutaneous Mycobacterium neoaurum infection causing scarring alopecia in an immunocompetent host. Martin LK, Lawrence R, Kossard S, Murrell DF. Br J Dermatol. 2007 Jul;157(1):204-6. Epub 2007 May 14. No abstract available. 5)
3: [Scarring tinea profunda in the pubic area due to Trichophyton verrucosum] Grunewald S, Paasch U, Gräser Y, Glander HJ, Simon JC, Nenoff P. Hautarzt. 2006 Sep;57(9):811-3. German. 6)
Balding in 20s linked to doubled risk of prostate cancerShare698(2)
By Thomas H. Maugh II, Los Angeles Times February 16, 2011, 9:40 a.m. Men who go bald in their early 20s have a doubled risk of developing prostate cancer, but those who lose hair in their 30s and 40s apparently are not at greater risk, French researchers reported Tuesday. The findings suggest that men who lose their hair very early in life might benefit from increased screening.
Because the same male hormones that are involved in hair growth also play a role in prostate cancer, researchers have been tantalized by possible links between balding and prostate cancer. But past studies have yielded conflicting results or none at all.
Dr. Philippe Giraud, a professor of radiation oncology at Paris Descartes University, and Dr. Michael Yassa, a radiation oncologist who is now at the University of Montreal, studied 388 men being treated for prostate cancer and 281 healthy men, questioning them about their history of hair loss. They reported in the Annals of Oncology that 37 of the men with prostate cancer had some balding at the age of 20, but only 14 of the healthy men had had balding at that age. But there was no association with the type or pattern of hair loss, they reported, and no association with balding at older ages.
Androgenic alopecia, sometimes known as male pattern baldness, is common in men, affecting about half of them throughout the course of their lives. It is related to androgenic hormones, and androgens also play a role in the onset and growth of prostate tumors. The widely used drug finasteride blocks the conversion of the male hormone testosterone to an androgen called dihydrotestosterone, which is thought to play a role in hair loss, and the drug, known as Propecia, is used to treat hair loss. It also has been shown to decrease the incidence of prostate cancer and is sold as Proscar for that purpose.
PSA screening for prostate cancer is generally not begun until men are in their 40s and 50s, but Giraud and Yassa suggested that it might be useful to start it somewhat earlier for men who go bald in their 20s because of their increased risk. Experts cautioned, however, that the number of people involved in the study was small, so the results should be interpreted with care.
Other risk factors for prostate cancer include age, family history of the disease, diet, lifestyle and ethnicity.
Dermatol Online J. 2010 Feb 15;16(2):3. Does D matter? The role of vitamin D in hair disorders and hair follicle cycling. Amor KT, Rashid RM, Mirmirani P.
Department of Dermatology, University of Texas and MD Anderson Cancer Center, Houston, Texas. firstname.lastname@example.org. BACKGROUND: The role of vitamin D in the proliferation and differentiation of keratinocytes is well known within the field of dermatology. OBJECTIVE: We sought to evaluate the role that vitamin D and the vitamin D receptor play in the hair cycle and assess how this can be clinically applied to the treatment of hair disorders. METHODS: A MEDLINE search (1955-July 2009) was preformed to find relevant articles pertaining to vitamin D, the vitamin D receptor, and hair loss. RESULTS: The vitamin D receptor, independent of vitamin D, plays an important role in hair cycling, specifically anagen initiation. The role of vitamin D in hair follicle cycling is not as well understood. LIMITATIONS: The review is broad and there are limited human studies available to date. CONCLUSION: Additional studies to evaluate the role of vitamin D in the hair cycle should be done. Treatments that up regulate the vitamin D receptor may be successful in treating hair disorders and are a potential area of further study. 7)
From: BaneDate: 2011-10-20 03:36:53 Reply: http://www.marshallprotocol.com/reply.php?topic_id=10978
The hair cycle and Vitamin D receptor. 8)
The Vitamin D receptor (VDR) plays a critical role in epidermal homeostasis. The ligand-dependent actions of the VDR attenuate epidermal keratinocyte proliferation and promote keratinocyte differentiation. Calcium can compensate for the absence of the VDR in maintaining a normal program of epidermal keratinocyte differentiation both in vitroA technique of performing a given procedure in a controlled environment outside of a living organism - usually a laboratory. and in vivo. In contrast, the effects of VDR ablation on the hair follicle cannot be prevented by maintaining normal calcium levels and are independent of 1,25-dihydroxyvitamin D. These actions of the VDR are critical in the keratinocyte stem cell population that resides in the bulge region of the hair follicle. Absence of a functional VDR leads to a self-renewal and lineage progression defect in this population of stem cells, resulting in the absence of post-morphogenic hair cycles. The molecular partners and downstream target genes of the VDR in this unique population of cells have not yet been identified.
— Sallie Q 02.26.2017 re-arranged content and added a recent reference