Total Hair Density Research Articles

Diversity in human hair growth, diameter, colour and shape. An in vivo study on young adults from 24 different ethnic groups observed in the five continents.

Based on previous findings, from a worldwide study, classified the shapes of human hair into 8 major types, from straight to highly curly. This clearly extended the usual classification of hair into African, Asian or Caucasian types. However, determinations of hair growth parameters and hair density were excluded from such studies. To measure and compare the hair growth profiles of young adults without alopecia living in the five continents. 2249 young adults (18-35 years, females and males) without alopecia, originating from 24 various human ethnic groups were included in the study. Total hair density, telogen percentage and growth rate on three different scalp areas were measured, using non-invasive validated techniques. Natural hair colour level, curliness and hair diameter were additionally recorded, when practically possible. Diversity in hair growth parameters among the entire cohort was a key finding, with differences linked to scalp area, gender and geographic origin. Statistical approaches depicted African hair as having lower density and a slower growth rate. Asian hair showed a thicker diameter, with faster growth. Caucasian hair showed a high total hair density. On the one hand, this inter-continental study of hair growth parameters provides initial valuable base-line data on hair in young adults without alopecia, and on the other hand, further extends our knowledge of this unique human appendage, with some mosaic features, observed worldwide.

Comparisons of Physical Characteristics of Crossbred Boer Goat Fur Skin Tanned by Coffee Pomace and Gros Michel Banana Bunch

The current study was conducted to compare the physical characteristics and quality of fur skin of male crossbred Boer goat using different tanning formulas (coffee pomace and Gros Michel banana bunch). Crossbred Boer goat aged approximately 8 months old and weighed approximately 25kg were used in the study. Sixteen skin sheets prepared by cutting raw skin into a size of 21×29.7 cm2 were divided into 2 treatments, 8 sheets each. The first group was tanned using coffee pomace formula and the second group was tanned using Gros Michel banana bunch formula. The raw skin weights of the first group and second group before tanning were 198.25±8.66g and 197.72±7.64g, respectively. Tanned fur skin were then compared for physical characteristics, including skin color, total hair density, percentage of coarse hair, percentage of fine hair, and skin thickness, both before and after tanning process and between the tanning formulas. The results showed that the color of goat skin before tanning with Gros Michel banana bunch and coffee pomace formula was not significantly different (P>0.05). While after tanning with coffee pomace, the skin was darker than those tanned with Gros Michel banana bunch, although hair color of both groups were not altered (P>0.05). The thickness of the tanned skin using Gros Michel banana bunch and coffee pomace formula was not significantly different (P>0.05). Fine hair density and coarse hair density of both groups before soaking in Gros Michel banana bunch and coffee pomace formula were not significantly different (P>0.05). However, after tanning with both formula, it was found that density of fine and coarse hairs of both groups were less than initial hairs (P<0.05). In conclusion, coffee pomace and Gros Michel banana bunch can be used as agent in tanning process to conserve the goat hair.

The Effect of Platelet-Rich Plasma in Hair Regrowth: A Randomized Placebo-Controlled Trial.

Platelet-rich plasma (PRP) has emerged as a new treatment modality in regenerative plastic surgery, and preliminary evidence suggests that it might have a beneficial role in hair regrowth. Here, we report the results of a randomized, evaluator-blinded, placebo-controlled, half-head group study to compare, with the aid of computerized trichograms, hair regrowth with PRP versus placebo. The safety and clinical efficacy of autologous PRP injections for pattern hair loss were investigated. PRP, prepared from a small volume of blood, was injected on half of the selected patients' scalps with pattern hair loss. The other half was treated with placebo. Three treatments were administered to each patient at 30-day intervals. The endpoints were hair regrowth, hair dystrophy as measured by dermoscopy, burning or itching sensation, and cell proliferation as measured by Ki67 evaluation. Patients were followed for 2 years. Of the 23 patients enrolled, 3 were excluded. At the end of the 3 treatment cycles, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 33.6 hairs in the target area, and a mean increase in total hair density of 45.9 hairs per cm² compared with baseline values. No side effects were noted during treatment. Microscopic evaluation showed the increase of epidermis thickness and of the number of hair follicles 2 weeks after the last PRP treatment compared with baseline value (p < .05). We also observed an increase of Ki67(+) keratinocytes in the epidermis and of hair follicular bulge cells, and a slight increase of small blood vessels around hair follicles in the treated skin compared with baseline (p < .05). Relapse of androgenic alopecia was not evaluated in all patients until 12 months after the last treatment. After 12 months, 4 patients reported progressive hair loss; this was more evident 16 months after the last treatment. Those four patients were re-treated. Our data clearly highlight the positive effects of PRP injections on male pattern hair loss and absence of major side effects. PRP may serve as a safe and effective treatment option against hair loss; more extensive controlled studies are needed. Platelet-rich plasma (PRP) has emerged as a new treatment modality in regenerative plastic surgery, and preliminary evidence suggests that it might have a beneficial role in hair regrowth. Here, the results of a randomized, placebo-controlled, half-head group study to compare the hair regrowth with PRP versus placebo are reported. Hair regrowth was quantified by a blinded evaluator using computerized trichograms. The safety and clinical efficacy of autologous PRP injections for pattern hair loss were investigated. Of the 23 patients enrolled, 3 were excluded. At the end of the 3 treatment cycles, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 33.6 hairs in the target area and a mean increase in total hair density of 45.9 hairs per cm² compared with baseline values. No side effects were noted during treatment. The data clearly highlight the positive effects of PRP injections on male pattern hair loss and absence of major side effects. PRP may serve as a safe and effective treatment option against hair loss; more extensive controlled studies are needed.

The effect of autologous activated platelet rich plasma (AA-PRP) injection on pattern hair loss: clinical and histomorphometric evaluation.

To investigate the safety and clinical efficacy of AA-PRP injections for pattern hair loss. AA-PRP, prepared from a small volume of blood, was injected on half of the selected patients' scalps with pattern hair loss. The other half was treated with placebo. Three treatments were given for each patient, with intervals of 1 month. The endpoints were hair re-growth, hair dystrophy as measured by dermoscopy, burning or itching sensation, and cell proliferation as measured by Ki-67 evaluation. At the end of the 3 cycles of treatment, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 18.0 hairs in the target area, and a mean increase in total hair density of 27.7 ( number of hairs/cm2) compared with baseline values. Microscopic evaluation showed the increase of epidermis thickness and of the number of hair follicles two weeks after the last AA-PRP treatment compared to baseline value (P < 0.05). We also observed an increase of Ki67+ keratinocytes of epidermis and of hair follicular bulge cells and a slight increase of small blood vessels around hair follicles in the treated skin compared to baseline (P < 0.05).

Nutritive Beeinflussung des Haarwachstums

Ziel der Studie: Haarausfall ist ein weit verbreitetes Problem bei Frauen und Männern. Ziel der klinischen Studie war die Prüfung eines nutritiven Konzeptes mit Bockshornsamenextrakt und Mikronährstoffen auf den anlagebedingten Haarausfall.

Automated digital image analysis (TrichoScan®) for human hair growth analysis: Ease versus errors

Background:TrichoScan® is considered to be time-saving, easy to perform and consistent for quantifying hair loss/growth. Conflicting results of our study lead us to closely observe the image analysis, and certain repeated errors in the detection of hair were highlighted.Aims:To assess the utility of TrichoScan in quantification of diffuse hair loss in males with androgenetic alopecia (AGA) and females with diffuse telogen hair loss, with regard to total hair density (THD), telogen and vellus hair percentages.Materials and Methods:TrichoScan procedure was performed on 77 cases and 20 controls.Results and Discussion:In the cases, THD decreased with increasing severity of alopecia. Surprisingly, more than 85% of the healthy volunteers had an unexplained abnormal telogen hair percentage of more than 20. Also, the telogen hair percentages were not significantly different between cases and controls. Also, 65% of the patients with advanced thinning of hair did not have the expected elevation of vellus hair percentages on TrichoScan evaluation. Multiple errors were highlighted in hair detection by the software. Errors were noted at the exit points of follicular ostia, at places where hair strand thickness was not uniform throughout its length, where there was crossing, overlapping of the neighboring strands, and when more than one hair emerged from a single ostium.Conclusion:TrichoScan is promoted as a validated and precise tool for measurement of hair growth parameters. Under certain conditions, it may seem suitable for clinical trials evaluating treatment response. We provide evidence that this is an overstatement. This study concludes that TrichoScan-analyzed anagen/telogen hair detection is not optimal; moreover, there is overestimation of THD and the vellus hair percentage does not correlate with clinical severity of alopecia. The current form of TrichoScan, though easy to use, is error-prone and awaits refinement.

AN ANALYSIS OF CALIFORNIA SEA OTTER (ENHYDRA LUTRIS) PELAGE AND INTEGUMENT

AbstractThe sea otter is associated with a cold, marine habitat, has no insulating fat layer, and relies on its fur layer for insulation. Soiled pelage provides inadequate insulation and can lead to hypothermia and death. Information on sea otter pelage, the surface and bound lipids found in the pelage, and histology of the integument is thus relevant to the development of rehabilitation and management techniques for sea otters soiled with oil. We present detailed data on the sea otter pelage and integument, including hair bundle density (737–2,465 bundles per cm2), hair density per bundle (19–91.1), total hair density (26,413–164,662 hairs per cm2), guardhair length (8.2–26.9 mm), underfur length (4.6–15.8 mm), guardhair diameter (44.0–106.0 μ), underfur diameter (7.6–11.9 μ), angle of hair with respect to the skin (61.9°‐ 84.3°) and structure of individual hairs as seen with a scanning electron microscope. The hydrocarbon squalene was found to be the major component of the lipids associated with the pelage. Various layers of skin from eight sites on a single animal are described histologically. With the exception of density of the hair coat, sea otter integument is similar to that of domestic carnivores.

Natural progression of male pattern baldness in young men

Twenty-six men who presented with male pattern baldness (androgen-dependent alopecia), were quantitatively evaluated for scalp hair variables and compared with 13 age-matched controls. Compared to controls, significant mean differences for hair variables were found in the frontal-vertex area, while in the occipital area, a reduction in total hair density (hairs/cm2) was the only significant (P less than 0.05) finding. A large proportion (48.5%) of meaningful hair (non-vellus hair) was less than or equal to 40 mm in length, yet had diameters similar to hairs growing much longer. In controls, these hairs accounted for only 12.2% of the total population. Compared to baseline, mean values from the frontal-vertex area of subjects with androgen-dependent alopecia were significantly lower for total hair density, meaningful hair density (non-vellus hairs/cm2) and percentage of hair in the anagen growth phase, 12 and 24 months later. During this time, total hair density decreased by 6.5% after 12 months and by 11.9% after 24 months. Similarly, meaningful hair density declined at 12 months by 10.8% and by 22.7% after 24 months. No change in any hair variable was detected in controls after 12 or 24 months. Our findings suggest that medications capable of maintaining the existing hair population should be regarded as effective treatments for this condition. Left untreated androgen-dependent alopecia progressively deteriorates. The induction of non-vellus hairs less than or equal to 40 mm in length to grow longer, would substantially improve the aesthetic profile without the need to generate new hair.