Hair counts from scalp biopsy specimens in Asians

Lee, Hyun-Jeong; Ha, Sang Jin; Lee, Joo-Han; Kim, Jin-Wou; Kim, Hyung-Ok; Whiting, David

doi:10.1067/mjd.2002.119558

Cited by 91 publications

(81 citation statements)

References 8 publications

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“…Though it is speculated that Asians have fewer nasal hairs than Caucasians, such data on nasal hair density are lacking. However, significantly lower head hair density as well as follicular density was found in Koreans than in whites and blacks (Lee et al 2002). Therefore, as an indirect evidence, nasal hair density in the Taiwanese adults of the current study is very likely lower than that of Caucasian subjects in the previous studies and is likely another cause for the lower nasal particle deposition.…”

Section: Resultsmentioning

confidence: 39%

In-Vivo Measurements of Micrometer-Sized Particle Deposition in the Nasal Cavities of Taiwanese Adults

Hsu

Chuang

2012

Aerosol Science and Technology

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It has been observed that Asians and Caucasians possess considerably different craniofacial features, which may affect the anatomical structure of the upper respiratory tract and, consequently, the characteristics of particle deposition. Most deposition studies on the human respiratory tract were primarily based on a limited number of Caucasian subjects. Therefore, data of the particle deposition efficiency in the upper respiratory tract of Asians are needed to supplement the understanding of the deposition characteristics in the human respiratory tract. This study measured the nasal deposition efficiency of particles ranging from 0.5 to 20 µm in five Taiwanese male and four Taiwanese female adults under different inspiratory flow rates. The measured deposition efficiency showed a very large intersubject variability in the inertial parameters, ranging between 10 3 to 5 × 10 4 µm 2 cm 3 /s, and the deposition efficiency of the subjects with similar values of the minimum nasal cross-sectional area approaches to each other. This study showed that Taiwanese adults have lower nasal deposition efficiency than Caucasians, and that the differences in the nostril shape, inclination of nostrils, and nasal hair density between the two ethnic groups are likely the causes. In addition, this study suggested that up to 15% of overestimation in the nasal deposition efficiency for larger particles may occur if the inhalation efficiency is not considered. An empirical equation adopting inspiratory flow rate and the minimum nasal cross-sectional area was developed to predict the nasal particle deposition in the upper airway of Taiwanese adults.

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Section: Resultsmentioning

confidence: 39%

In-Vivo Measurements of Micrometer-Sized Particle Deposition in the Nasal Cavities of Taiwanese Adults

Hsu

Chuang

2012

Aerosol Science and Technology

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“…In contrast, Iranian males have more terminal and vellus hairs (35.2 ± 7.2 and 2.5 ± 1.4, respectively) than females (31.1 ± 2.7 and 2.2 ± 0.8) [6]. In Koreans, the number of terminal hairs is higher in females (16 ± 2.9) compared with males (14 ± 3.3) [4]. But Taiwanese men and women have similar numbers of terminal hairs and vellus hairs (20.9 ± 4.1 and 0.9 ± 1.1, respectively, in men, versus 19.9 ± 5.3 and 0.6 ± 0.8 in women) [5].…”

Section: Discussionmentioning

confidence: 99%

Quantification of Hair Follicles in the Scalp in Mexican Mestizo Population

Martínez-Luna

Rodríguez-Lobato

Vázquez-Velo³

et al. 2018

Skin Appendage Disord

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Introduction: There are no reports of the density of hair follicles in the scalp of Mexican mestizo population, necessitating the determination of normal references values for this population compared with other ethnic groups. Objective: To determine the average hair follicle count on the scalp in Mexican mestizo population. Materials and Methods: A total of 50 scalp samples (25 men and 25 women) from Mexican mestizo individuals aged between 19 and 60 years, with no clinical evidence of hair disease, obtained by biopsy punch at General Hospital “Dr. Manuel Gea González” were collected over 2 years. The total follicular density, vellus and terminal hair follicles, and the percentage in anagen and catagen-telogen phase were measured. χ² was used as the basic statistical test. Results: The mean number of total hair follicles in our Mexican mestizo population was 23.2 ± 4.2, which is lower compared with Thais, Iranians, and Caucasians. However, the ratio of terminal and vellus hair follicles was higher than in Thais, Caucasians, and African-Americans. The percentage of terminal hairs in anagen phase was lower than in the other populations, and higher in telogen, without exceeding 15%, established as the normal reference value. There was an association between sex and terminal hairs in telogen phase (p < 0.05). The average follicular density per mm² was slightly higher compared with African-Americans and Asians. Women had more terminal hairs than men. Conclusions: The density of total follicles is lower in the Mexican mestizo population compared with Iranians, Thais, and Caucasians. However, the greater number of terminal hairs compared to vellus hairs gives the appearance of greater overall volume. The results of this study can be used as a reference for diseases of the scalp in the Mexican population.

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“…Asian hair fiber has the greatest diameter with circular geometry [71,72]. African hair has elliptical cross section diameters changing along the hair fiber length; it is a flattening twisted oval rod-shaped fiber with random reversals in direction [71].…”

Section: Differences On Ethnic Hair Fiber Characteristics and Propertiesmentioning

confidence: 99%

Human Hair and the Impact of Cosmetic Procedures: A Review on Cleansing and Shape-Modulating Cosmetics

et al. 2016

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Abstract:Hair can be strategically divided into two distinct parts: the hair follicle, deeply buried in the skin, and the visible hair fiber. The study of the hair follicle is mainly addressed by biological sciences while the hair fiber is mainly studied from a physicochemical perspective by cosmetic sciences. This paper reviews the key topics in hair follicle biology and hair fiber biochemistry, in particular the ones associated with the genetically determined cosmetic attributes: hair texture and shape. The traditional and widespread hair care procedures that transiently or permanently affect these hair fiber features are then described in detail. When hair is often exposed to some particularly aggressive cosmetic treatments, hair fibers become damaged. The future of hair cosmetics, which are continuously evolving based on ongoing research, will be the development of more efficient and safer procedures according to consumers' needs and concerns.

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Hair counts from scalp biopsy specimens in Asians

Cited by 91 publications

References 8 publications

In-Vivo Measurements of Micrometer-Sized Particle Deposition in the Nasal Cavities of Taiwanese Adults

In-Vivo Measurements of Micrometer-Sized Particle Deposition in the Nasal Cavities of Taiwanese Adults

Quantification of Hair Follicles in the Scalp in Mexican Mestizo Population

Human Hair and the Impact of Cosmetic Procedures: A Review on Cleansing and Shape-Modulating Cosmetics

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