Gray Hair Black Iron Pdf Free Do PORTABLE
The pigmentary unit is a pear-shaped black structure at the tip of dermal papilla in pigmented hair. In gray hair, the pigmentary unit becomes fuzzy, the melanocytes become few and rounded, and lightly pigmented oligodendritic melanocytes become visible in the proximal hair bulb. During anagen, there is a marked reduction in the number of melanocytes in the hair follicles through autophagolysosomal degeneration leading to pigment loss. This is thought to be central in the pathogenesis of graying. Defective melanosomal transfer to cortical keratinocytes or melanin incontinence due to melanocyte degeneration contributes to graying. Degenerative changes within the hair follicle are associated with an increase in dendritic cells in the hair follicle. Eventually, there are no melanogenic melanocytes in the hair bulb.
Gray Hair Black Iron Pdf Free Do
Genetic and environmental elements influence the hair follicle stem cells and melanocytes. Telomere shortening, decrease in cell numbers, and certain transcription factors have all been implicated in this process of aging. In turn, these molecular alterations lead to structural modifications of the hair fiber, decrease melanin production, and lengthen of the telogen phase of the hair cycle.
Perhaps the role of reactive oxygen species (ROS) on graying of hair is most studied. During active growth phase, i.e., anagen phase there is active melanogenesis in the hair follicle. This involves hydroxylation of tyrosine and oxidation of dihydroxyphenylalanine to melanin causing enormous accumulative oxidative stress. The failure of antioxidant effect could damage melanocytes leading to decreased pigmentation.[12,22] Wood et al. demonstrated that the accumulation of hydrogen peroxide in hair follicles and absent expression of antioxidants such as catalase and methionine sulfoxide reductase in gray hair follicles. Their experiment supported the theory of prooxidant role in graying of hair. Oxidative stress can also be a result of ultraviolet (UV) rays, pollution, emotional factors, or inflammatory causes. Experiments have shown melanocyte apoptosis and oxidative damage in graying hair follicles. Furthermore, exogenous oxidative stress showed increased graying in the hair follicles. An experiment on mice demonstrated that UV radiation could cause oxidative damage on hair follicles causing hair graying. They also demonstrated that the protective effect of an antioxidant superoxide dismutase. Numerous studies have demonstrated increased oxidative load due to psychological stress implying that even emotional factors play a role in premature graying.[25,26] A recent study on young adults in Turkey revealed that PGH is closely related to factors causing oxidative stress such as emotional stress, alcohol consumption, and chronic diseases in genetically predisposed men and women. Daulatabad et al. made an attempt to measure oxidative stress load in PGH. They demonstrated an increase in prooxidants such as serum malonaldehyde, whole blood reduced glutathione, and serum ferric reducing antioxidant potential and decrease in antioxidants. Shi et al. demonstrated compromised antioxidant activity in gray hair follicles. Their experiments revealed that catalase protein expression and hydroxyl radical-scavenging activities are strongly repressed in unpigmented hair follicles.
Progeroid syndromes are associated with defective repair of DNA. Thus, DNA is more susceptible to oxidative stress. Vitiligo is another condition with early graying of hair. Melanocytes in patients with vitiligo are more sensitive to oxidative stress. ROS damage to melanocytes leads to ectopic differentiation of stem cells and apoptosis of differentiated melanocytes.
Vitamin B12 deficiency can cause PGH through unknown mechanism. About 55% of patients with pernicious anemia had graying before 50 years as compared to 30% in the control group. Decreased thyroid hormones cause premature graying, alopecia, and changes in hair morphology. Thyroid hormones T3 and T4 act on hair follicles directly to increase melanogenesis.
Smoking has been studied as an etiological agent in early-onset achromotrichia. Studies revealed that there was a significant correlation between smoking and premature hair graying. The possible explanation to this is the prooxidant effect of smoking on the body leading to increased ROS damage to hair follicle melanocytes.[38,39,40,41]
There is no single widely recognized standard scoring system to determine the severity of PGH. Attempts have been made to classify graying as mild, moderate, and severe based on percentage of hair involved, number of hair involved, or percentage of hair affected in various areas of the scalp. These grading systems used questionnaires and clinical examination to assess the severity of graying.[38,43,66,67,68]
Although many patients visit dermatology outpatient for the treatment of PGH, very few treatment options are satisfactory. The treatment for PGH should be directed to address the cause. Vitamin B12 deficiency and hypothyroidism are reversed with vitamin and hormone replacement, respectively. Plucking of gray hair is an easy option for individuals with
Although various vitamins and minerals such as biotin, calcium pantothenate, zinc, copper, and selenium are being prescribed, the results have not been promising. Calcium pantothenate is a commonly prescribed agent for PGH. Pasricha reported the cases of successful treatment of PGH in two adolescent girls treated with 200 mg of calcium pantothenate daily. They further investigated on 39 patients and concluded that high doses (200 mg/day) were beneficial for PGH. In addition, when combined with gray hair avulsion therapy, it yielded better results. Not all gray hair that were avulsed grew back as gray hair.
There have been anecdotal reports of temporary hair darkening with P-aminobenzoic acid (PABA). Sieve administered 200 mg PABA to 30 patients for 2 months and repigmentation was seen in all subjects. Zarafontes reported repigmentation of gray hair in patients who had received PABA for various indications. The authors, however, do not recommend the use of PABA for the sole purpose of darkening hair. Psoralen and UV A (PUVA)-sol was reported to be effective in PGH in one study. PUVA therapy stimulates melanocytes leading to pigmentation. However, repeated experiments failed to yield similar results. Topical prostaglandins have been used to stimulate melanogenesis. Bellandi et al. reported repigmentation of gray hair after using Latanoprost for around 3 years.
You may not know it, but the head dinosaur has just past the 50 year mark and is still pushing, pulling and tugging at the heavy black iron. Therefore, he understands the needs of the seasoned trainee. His training methods have had to evolve along with his age. Fortunately, he has put to paper those tried and true training methods that he has found to have really worked for him and will work for those trainees that share some of the same problems that naturally occur with middle age.
While some people celebrate gray hair as a sign of maturity and wisdom, many feel that they look older when their hair starts growing gray and would like the gray to go away for a more youthful appearance.
From Helen Mirren and Jane Fonda to George Clooney and Anderson Cooper, many people look distinguished with and embrace their gray hair. And many more, celebrities or otherwise, were forced to do so during the pandemic when salons shut down and it was challenging or impossible to keep up with professional touch-ups.
As each strand grows, all hair goes through a cycle of regeneration then death, and the cycle continues again and again throughout the lifespan as long as your hair follicles remain active. (If they flip "off" and go dormant, that's when balding occurs.) As hair follicles encounter stressors and age, they can begin to produce less color each phase. Our genes partially determine when we begin to gray. In fact, the Library of Congress says our chance of going gray, on average, increases 10% to 20% every decade after age 30.
As hair grows from its follicle, melanocytes add pigment via melanin into the hair cells that contain keratin, the protein that makes up hair, nails and skin. Researchers believe the body has a "melanogenic clock" that can slow down or halt this melanocyte activity. This "clock" is controlled by our DNA, but it can be adjusted based on what the environment throws your way.
"It's a natural, age-related process whereby the cells that produce pigment start to die off, leaving fewer and fewer to add color to the hair strand, eventually causing the hair to have no color at all, therefore gray," explains Ted Lain, M.D., a board-certified dermatologist and the chief medical officer at Sanova Dermatology in Austin, Texas.
A 2020 study in the International Journal of Trichology found that oxidative stress (an imbalance of antioxidants and free radicals in the body that can trigger cell and tissue damage and accelerated aging) is linked to premature graying.
Some autoimmune and thyroid-related disorders can be related to premature graying, a 2018 International Journal of Trichology study confirms. Be sure to keep up with your yearly physicals and check in with our primary care doctor if anything feels "off" internally, or book an appointment with your dermatologist if you notice any big changes in the vitality of your skin or hair.
How early is too early for white hair depends on your genetics. A 2013 study suggested that white or gray hair is considered premature if it pops up before age 30 for black folks, age 25 for folks of Asian descent, and age 20 for white folks.
A 2016 study of people of European, Native American, and African descent even found a gene that researchers believe is responsible for 30 percent of gray hair. This gene is also more prevalent in people with lighter hair colors (thanks, Mom!).
Lifestyle choices like smoking also come into play. Lighting up is known to speed up skin aging and can cause premature grays. A 2013 study found that people who smoke cigarettes have more gray hair before age 30.