Morphological, Macromolecular Structure and Hair Growth

This review discusses new developments in understanding the structure and properties of keratin fiber cell membrane complexes, without reporting new experimental results.

This study found that beard hair medulla cells express an unexpected range of keratins, showing variability and promiscuous behavior in keratin interactions distinct from other hair follicle cells.

This study found that the prevalence of androgenetic alopecia in Chinese men was lower than in Caucasian men, similar to Korean men, and most commonly presented as type III vertex.

This study found that in naturally curved human scalp hairs, distinct arrangements of cell types on either side of the hair fiber contribute to its curvature.

This study examined hair curvature in Japanese women, finding that 47% have curved hair, and identified structural differences in hair fiber, which resemble those in wool fibers.

In this study, researchers found that the curliness of human hair is associated with an asymmetric structure at the cellular level, particularly in the differentiation of the precortex.

Oxidation changes the structure of hair protein filaments, causing them to compact and rearrange.

This study observed that Japanese women experience diffuse central hair loss after age 40, characterized by reduced hair density and thicker hair ratio rather than vellus-like hairs.

This article discusses the influence of estrogens on hair follicle growth and metabolism, suggesting a significant role alongside androgens in hair growth control but reports no new clinical results.

This study concluded that the curliness of human hair, regardless of ethnicity, originates from the inhomogeneous internal nanostructure due to differences in the distribution of two types of cortices.

This article reviews the stages and regulation of the hair cycle, highlighting molecular regulators involved, but it does not present new research findings.

This article reviews modern hair transplantation techniques, noting that while many innovations have improved natural-looking results and expanded candidate eligibility, some may have hidden drawbacks, and it reports no new results.

Different ethnic groups have unique hair growth patterns, with African hair growing slower and less dense, Asian hair growing fast but sparse, and Caucasian hair being densest; men are more likely to experience hair loss than women.

This study found that the absence of Sgk3 in mice leads to impaired hair follicle maturation, characterized by reduced cell proliferation, increased apoptosis, and premature regression.

This review examines mechanical and chemical causes of hair fiber adhesion failure and fracture patterns in the cell membrane complex, but presents no new experimental results.

Hard α-keratin in hair has a unique, nonordered structure, different from other fibers.

This study found that continuous β-catenin signaling in adult mouse epidermis can reprogram hair follicles to form benign tumors, which regress after the signaling is discontinued.

This review discusses advances in understanding hair and hair follicle structure, gene expression, and molecular signals in hair formation, without reporting new clinical findings.

This review discusses the hair eclipse phenomenon in hair cycling and the potential roles of synchronizers and microinflammation in its occurrence, reporting no new empirical findings.

This review discusses advancements in gene delivery to hair follicles and suggests potential gene therapy applications for treating hair loss, but it reports no new experimental results.

This study found that hair diameter increases toward the scalp during pregnancy, a novel observation compared to the normal decrease seen in nonpregnant women.

In this study, Msx2-deficient mice showed progressive hair loss due to shortened anagen phase and prolonged catagen and telogen phases, resulting in cyclic alopecia with structurally abnormal hair shafts.

This review summarizes recent advances in understanding the molecular mechanisms of hair follicle formation and discusses potential future clinical applications for treating hair loss and skin tumors, but it reports no new clinical results.

This study cataloged human type II hair keratins, detailing their expression and differentiation roles in hair follicles and comparing them with type I keratins to explore keratin-pairing principles.

In this study, the prevalence of androgenetic alopecia among Korean men and women was found to be lower than in caucasians, with Korean men showing more frontal hairline preservation and a higher incidence of 'female pattern' hair thinning.

This study identified a cluster of genes on chromosome 17 related to hair keratin-associated proteins, including 37 genes forming seven multigene families, localized in the hair shaft's upper cortex.

This study found that specific genetic markers near the androgen receptor gene are significantly more common in men with male pattern baldness, suggesting a genetic component in its development.

FPHL affects hair density and diameter, causing visible hair loss in older women.

This study demonstrated that multipotent stem cells in adult mice whisker follicles migrate to produce whisker growth, and that this process requires precise control of stem cell trafficking.

Hair loss in women is common, starts in late 20s, and affects 30% of women over 50.

Inhibiting Bmp signaling disrupts hair growth and differentiation.

This study reports that activating Notch signaling in the hair follicle cortex of transgenic mice caused abnormal differentiation of the medulla and cuticle, highlighting potential cell-cell interactions.

This study found that LEF1/TCF3 is necessary but not sufficient for TOPGAL activation in hair follicle development, indicating complex regulation in the skin.

This article discusses the biologic and psychosocial significance of hair, the current limitations in hair growth drugs, and anticipates future therapies based on advancing hair follicle research.

This study found that the loss of a functional hr gene in mice leads to premature and abnormal hair follicle regression, disrupting normal hair cycling and architecture.

This study establishes a catalog of human type I hair keratins and identifies their specific roles and expression patterns during hair differentiation and growth in scalp follicles.

This study found that hair density is significantly lower in African Americans compared to whites, which may affect the evaluation and diagnosis of scalp biopsy specimens in this population.

This study identified a missense mutation in the human hairless gene associated with a rare form of recessively inherited alopecia universalis, pinpointed on chromosome 8p12.

This article integrates existing literature on hair follicle structure and formation at the cellular and molecular level, reporting no new findings.

This review examines the histochemistry and keratinization processes of human hair, exploring the structural roles of keratin proteins, protein chains, and lipids, but offers no new results.

Finasteride increases hair growth, prolongs hair cycle, and lowers dihydrotestosterone levels.

This study found that 4 weeks of finasteride treatment significantly decreased DHT levels in bald scalp to levels similar to hair-containing scalp in men with male pattern baldness.

This study concluded that epidermal growth factor may induce a 'catagen-like' phase in human hair follicles by disrupting normal cellular proliferation and migration patterns.

This study found that the formation of the fibre cuticle surface in Merino sheep is similar to the epidermal stratum corneum process and not from a modified plasma membrane as previously thought.

This study concluded that horizontal sections of scalp biopsy specimens provide more diagnostic information for male pattern androgenetic alopecia than vertical sections and can predict hair regrowth potential following topical minoxidil therapy.

This research observed that sheep and rabbit KAP6 genes, expressed in hair follicle cells, have high sequence similarity and indicate conservation due to evolutionary selection pressures.

Glycoproteins are present in the cell membranes of various keratin fibers.

Diffuse alopecia in women may be related to androgens and iron deficiency, and basic hormone and nutrient screening is useful.

This study found that sebaceous glands in bald scalp have greater androgen binding affinity and capacity than those in hairy scalp, possibly contributing to the androgenic response seen in male pattern baldness.

In this study, researchers used three-dimensional reconstruction to show that the shape of the hair follicle determines the hair's form, with variations observed among different racial groups.

The document concludes that treatments for female hair loss and excessive hair growth are temporary and not well-studied.

This study found significant species differences in the enzyme activity and inhibitor affinities of prostatic 5α-reductases from rats, dogs, and humans, with variable potencies for different 3-oxo-4-azasteroid inhibitors across species.

This study found that the moisture content of human hair significantly influences the type of fracture under tensile loading, with low or high humidity levels leading to smooth fractures and intermediate humidity resulting in step fractures.

This article presents a classification system for stages of female-pattern androgenetic alopecia to aid early diagnosis and mentions existing systems for rare male-pattern cases, but reports no new clinical results.

This study found that papain/bisulfite disintegrates human hair cuticles by dissolving the endocuticle, potentially accelerated by ethanol's removal of cell membrane material.

A fatty acid/protein complex in human hair helps protect it from damage.

This article reports electron microscope studies on the structure of hair and wool, but it does not present new clinical findings.