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Concept: Long hair


The synthesis and detailed characterization of gold nanoparticles (AuNPs) inside human hair has been achieved by treatment of hair with HAuCl(4) in alkaline medium. The AuNPs, which show a strong red fluorescence under blue light, are generated inside the fiber and are arranged in the cortex in a remarkably regular pattern of whorls based on concentric circles, like a fingerprint. It opens an area of genuine nanocomposites with novel properties due to AuNPs inside the hair shaft.

Concepts: Fluorescence, Ultraviolet, Nanoparticle, Light, Gold, Hair, Hair whorl, Long hair


The present study assessed the suitability of using QuEChERS procedure for the simultaneous determination and quantification of 37 multi-class pesticides in human hair. Matrix co-eluted material had a large influence on instrumental response sensitivity. Purification was needed although dSPE cleanup sorbent selection critically influenced analyte recovery. Optimized protocol using Z-Sep+ sorbent successfully achieved recovery of 28 pesticides with high sensitivity, precision, and accuracy. Limits of detection ranged from 0.2 to 86.6 pg mg-1 and from 0.5 to 6.3 pg mg-1 for GC and UPLC amenable substances respectively. Pyrethroid pesticides were the most influenced by matrix effects which explained the higher limits of quantification retained for these substances. On the contrary, high sensitivity was achieved for UPLC amenable substances (LOD < 1 pg mg-1 for atrazine, deisopropylatrazine, desethylatrazine, and imidacloprid). Suitability for monitoring pesticide exposure was assessed by application of the proposed protocol to samples collected on the field. Hairs of the volunteers were found positive to 8 pesticides with every sample containing at least one residue. Among these pesticides, only 3 were reported as used in local vegetable production, which suggested other sources of exposure. The developed method offers a sensitive, robust, and accessible tool for biomonitoring of human exposure.

Concepts: Protein, Pesticide, Object-oriented programming, Hair, Hair follicle, Insecticide, DDT, Long hair


AGA is a common disorder. Different treatments are available to prevent hair loss and achieve hair growth with variable results. The purpose of the present study was to evaluate the efficacy and safety of a novel fractional radiofrequency (RF) device (HairLux, Innogen Technologies Ltd., Yokneam, Israel), to prevent hair loss and induce hair growth. Twenty-five patients received 10 fractional RF treatments every 2 weeks, and were followed up 2 months after the last treatment. All patients were evaluated by global photography. In 10 patients, blinded manual hair counts were performed. Patients demonstrated less hair shedding, fuller hair, and faster hair growth. There was an average increase of 31.6% in hair density (based on hair counts) and 18% increase in hair shaft thickness. All subjects tolerated the treatments well. The HairLux device is effective and safe for hair growth stimulation in AGA. Ten treatment sessions are recommended to maximize results.

Concepts: Present, Effectiveness, Efficacy, Hair, Facial hair, Radio frequency, Long hair


The human hair is a complex structure with a diversity within itself. There is a wide variation in distribution and spatial arrangement of hairs.

Concepts: Species, Hair, Hair follicle, Long hair


Resolution of mitochondrial (mt) DNA heteroplasmy is possible when applying a massively parallel sequencing (MPS) approach. However, interpretation criteria for matching heteroplasmic sequences will need to be established that address a number of important topics, including the drift of variants in sample types such as human hair shafts. Prior to MPS analysis, we compared three different DNA extraction methods for hair using a custom mtDNA quantitative PCR (mtqPCR) assay, and found that a method involving bead capture significantly outperformed methods currently in place in forensic laboratories. The findings were similar for both fine (head) and coarse (pubic) hairs. Using the favored DNA extraction approach, hair shaft extracts were subjected to MPS analysis to assess heteroplasmic drift and the potential impact of the observations on interpretation of mtDNA MPS data. Hairs from different regions of the head were evaluated in individuals with varying percentages of heteroplasmy (low-level, high-level, and no detectable heteroplasmy), as measured in buccal and blood cells. The range of variant ratios was broad and was not significantly different between individuals in the low and high-level groups. While the range was also broad for the group of individuals with no heteroplasmy, the vast majority of hairs from these donors still exhibited a lack of heteroplasmy. A model was developed to predict the amount of heteroplasmy expected in hair samples when knowledge of the percentage of heteroplasmy in buccal cells is available. While significant, the model was best applied when levels of heteroplasmy in buccal cells was high. No correlation was observed between rates of heteroplasmy in blood cells and the predicted amount of heteroplasmy in hairs. Of particular interest, unexpected sites of mixed mtDNA sequence that could be interpreted as heteroplasmy were observed for 13% of the 75 hairs tested. These sites can be explained as heteroplasmy not observed in buccal or blood cells, or sites of DNA damage, with inherent heteroplasmy a likely cause, possibly due to de novo mutation events. Overall, when applying an MPS approach to hair analysis, heteroplasmic variant ratios may be quite different than those observed in blood cells, may be correlated to rates in buccal cells, and may include unexpected mixed sites. The results of this study directly impact MPS analysis of minor sequence variants from hair samples, and are particularly relevant to clinical and forensic investigations.

Concepts: DNA, Protein, Mutation, Mitochondrion, Mitochondrial DNA, Hair, Hair follicle, Long hair


More parameters have been used for more detailed description of mechanical properties of human hair as a fibre than in analogous studies. All measured samples were taken from five different locations on the heads of 60 women of varied age.

Concepts: Caucasian race, Hair, Long hair


A 66-year-old white woman presented to her primary care clinic with concerns about hair loss, which began 2 years ago. Recently, she had noticed some “bumps” on her cheeks, as well.

Concepts: United Kingdom, White people, Hair, Long hair


The deposit and adherence of particulate matter (PM’s) from aerial pollution onto the surface of human hair is a poorly studied phenomenon.

Concepts: Particulate, Hair, Air pollution, Long hair


Oleanolic acid (OA), a pentacyclic triterpenoid compound which can be found in >1600 plants, has been shown to promote hair growth. To study the mechanisms of OA on hair growth, we investigated hair follicle (HF) growth on four different concentration OA using human hair follicle organ culture model. We found that HFs treated with 1 or 10μg/mL OA showed statistically enhanced elongation of the hair shaft and anagen-like stage. Moreover, higher positive rate of Ki-67, a matrix cellular marker of proliferation, was detected in the same groups treated with 1 or 10μg/mL than those treated with vehicle. We further demonstrated that β-catenin, a key Wnt signaling transducer, was highly expressed in the OA treated groups using immunofluorescence stain assay. These results suggest that OA may promote human hair growth by stimulating hair matrix cell proliferation through the Wnt/β-catenin pathway.

Concepts: Protein, Cell, Hair, Hair follicle, Facial hair, Long hair


We report a case of Noonan syndrome with loose anagen hair (NS/LAH), a rare variant of Noonan syndrome, with associated trichorrhexis nodosa and trichoptilosis. The SHOC2 mutation may be responsible for these additional hair shaft defects, revealing the importance of microscopic examination of hairs in these patients.

Concepts: Protein, Hair, Hair follicle, Long hair, Trichorrhexis nodosa