Article

Ceramide binding to African–American hair fibre correlates with resistance to hair breakage

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Abstract

Repetitive hair-relaxing treatments often applied to African-American hair weaken the hair structure. Therefore hair breakage is a common feature of African-American hair and an important cause of hair loss. Recently, by analysing the lipids extracted from human hair, a fraction of free-ceramide was isolated in which sphinganine was predominant. This study shows that this sphinganine-derived ceramide (i.e. C18-dhCer) binds to African-American hair and protects it from weakening caused by chemicals. To show this binding, we used two methods: radioactivity detection with a microimager™ and secondary ion mass spectrometry. We evaluated the benefits of C18-dhCer on African-American hair fibre, relaxed by guanidine hydroxide, using a new method called the Break'in Brush Technique (BBT®). This method determines the hair breakage resistance during a brushing. Using this technique, we have shown less breakage when applying a shampoo with ceramide. The present study opens new prospects for the development of products able to increase the protection, provide better care and meet the needs of African-American hair thanks to the effect of ceramide binding.

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... There is some evidence that hair relaxers may damage the condition of hair 10,11 and cause fiber fragility, 12 which may explain the shorter than expected lengths of relaxed hair. The occiput overlaps with the area where many stylists first apply the relaxer and hair at this site is more likely to be overprocessed which could increase hair breakage. ...
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Anecdotal data suggest that combed natural African hair reaches a length steady state. Easier grooming and anticipated long hair have made relaxers popular. These hypotheses were tested in a cross-sectional survey of 1042 school children using a piloted questionnaire and hair length measurements done on four scalp regions. Participants included 45% boys and 55% girls. Girls consider length important for hairstyle choice (P < 0.0001). There was no difference in mean length at 2 to 5 vs. > 5 years (P = 0.3) and at 1 to < 2 vs. 2 to 5 years (P = 0.99), suggesting that a steady state is reached within 1 year after a hair cut for combed natural hair [mean, 5.1 cm (4.3)]. Relaxed hair reached length steady state > 2 years after a haircut [mean, 10.9 cm (3.6)], was longer than natural hair (P < 0.0001), shorter than expected, and significantly shorter on the occiput than the rest of the scalp (P < 0.0001). Persistently short combed natural hair years after a hair cut suggests that breakage eventually equals new growth (i.e., steady state), which is likely to be variable. Relaxed hair, irrespective of last haircut, is also short; chemical damage as a limit to potential lengths needs confirmation. Relatively short occipital relaxed hair could be a clue to disease pathogenesis.
... There is some evidence that hair relaxers may damage the condition of hair 10,11 and cause fiber fragility, 12 which may explain the shorter than expected lengths of relaxed hair. The occiput overlaps with the area where many stylists first apply the relaxer and hair at this site is more likely to be overprocessed which could increase hair breakage. ...
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Three subjects with virgin African hair combed daily had surprisingly short hair length measurements of 40.1 +/- 14 mm, 60 +/- 10 mm, and 69 +/- 20 mm at 6 months, 1 year, and 3 years after a haircut, respectively. This observation raises the possibility that combing African hair on a daily basis may result in the equivalent of a daily haircut in some people. This observation is based on few participants and will require confirmation in population studies.
... The chemical composition of the mammalian hair shaft has been previously investigated using a large variety of methods, including quantitative bulk analysis, fiber X-ray diffraction, microanalytical techniques (Forslind, 1996), electron energy loss spectroscopy (Hallé got and Corcuff, 1993), X-ray photoelectron spectroscopy (Ward et al, 1993;Rankin, 1994;Peet et al, 1995), static and scanning secondary ion mass spectrometry (Gillen et al, 1999), histochemistry (Swift, 1997;Wollina, 1997), and autoradiography (Gautier and Bernard, 2001;Bernard et al, 2002). None of these methods, however, can map the chemical composition of a hair cross-section with similar precision and resolution. ...
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The elemental composition of melanin granules and other components of the hair shaft was determined by multi-isotope imaging mass spectrometry, a method with unique advantages for the visualization and quantification of stable isotopes and the elemental composition in study of the fine structure of biologic samples. We mapped and quantified the chemical composition of hair cross-sections using secondary ions generated from naturally occurring 16O, 12C14N, 32S, and 34S with a maximum lateral resolution of 35 nm. Based on these elemental maps of unprecedented resolution we obtained simultaneously the chemical fingerprints and the structural features, such as cuticle, melanin granules, the macro fibrils of the cortex, and small sulfur-rich domains in the medulla, in the hair cross-section. We found an intriguing distribution of 16O, 12C14N, and 32S in melanin granules that we interpret as a highly anisotropic pattern of oxidation.
... It is well known that sphinganine-derived ceramide binds to the hair, strengthens the cohesion between the cuticular cells of the hair, and protects it from weakening. 28 This might be one reason for the observed improved hair quality parameters. Secondly, direct absorption of sphinganine by the scalp might strengthen the hair follicle and rebuild the hair from inside. ...
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Background The effects of chemical straighteners on the scalp and hair shaft are not fully known, although such substances are widely used. Hair straightening became popular in Brazil with the use of formaldehyde and its derivatives, despite the prohibition by the current legislation. Objective To identify changes in hair shaft and scalp caused by the use of chemical straighteners. Methods A search was performed using keywords in three databases from 03/16/2020 to 05/20/2020, with publications between the years 2000 to 2020. After applying the inclusion and exclusion criteria, 33 articles were selected for review. Results In some studies, hair relaxers were associated with eczema, desquamation, pain, burns, and inflammation in the scalp. Hair loss, damage to the shaft, alteration in the color of the hairs and in the composition of their amino acids were observed. Findings are variable across the studies. Study limitations The search was restricted to three databases, in two languages, different study designs were accepted. Conclusions Straightening techniques can have side effects, including scalp inflammation, damage to the shaft, and hair loss. Its long-term effects remain unknown and further studies are necessary.
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Synopsis The practice and theory of permanent hair straightening are discussed. Hair straightening as a cosmetic process is the reverse of hair waving. It removes hair curliness and makes wavy hair straight. While it is generally accepted that permanent hair straightening can be achieved only at very high pH with strong alkali, we have observed that it can also be achieved at neutral pH with lithium salt, or even at acidic pH with resorcinol. Also, while some of these treatments do result in considerable loss of cystine, others leave the cystine entirely intact. Lanthionine is produced in some cases, but is absent in others. It appears that the prime requirement for an effective hair straightening treatment is to be able to induce supercontraction of the hair fiber. Based on these observations, a model is proposed to explain permanent hair straightening in terms of certain molecular events such as chain folding and alpha-beta transformation of the polypeptide in the hair keratin.
Chapter
Human hair consists of proteins, lipids, water, trace elements and pigments. The composition of the first four of these components is the focus of this Chapter. About two decades ago the emphasis on the proteins of hair was on its amino acid constituents which provided important information on the relative amounts of different functional groups in different types of hair and in different regions of the fiber. However, as a result of advances in the characterization and classification of the different proteins and genes of keratins and keratin associated proteins the focus today is on the proteins themselves. Several important new contributions to the composition of the surface layers of hair and the proteins of the cell membrane complex have been and are continuing and therefore are summarized in this Chapter. The current state of changes in the amino acids, proteins and lipids of hair by morphological region (including KAP and keratin proteins and where they reside), chemical and sunlight damage, diet, puberty and menopause, and other factors have been and are being made and are summarized here. An expanded section on metals in hair, where in the fiber these metals reside and the functional groups that they bind to and their effects on hair chemistry, toxicity and disorders are included.
Article
The alleged relationship between the cross sectional shape of the hair shaft and the form of the hair, eg, curly or straight hair, has been challenged. By serial sections of human hair follicles from ten patients representing the three biological races, the relation between the follicle form and the hair form was studied. Using three-dimensional computer-aided reconstruction it was demonstrated that the follicle form determines the hair form, eg, the Negroid follicle has a helical form, whereas that of the Oriental follicle is completely straight. The caucasoid follicle represent variation between these extremes. However, even a straight caucasoid follicle may produce a hair shaft that has an oval cross section.
Conference Paper
Using a scanning ion microprobe we analyzed the distribution of labelled thymidine along human chromosomes. Two labels have been used: bromodeoxyuridine (BrdU which contains one bromine atom per molecule) and 14C-thymidine (which contains either one or ten 14C atoms per molecule). Both types of labelled nucleosides can be detected with our insirument. Best results are obtained when using the uniformly labelled thymidine (U-14C-thymidine) and adding up in a KONTRON IBAS image processing system the sequential analytical maps acquired from the sample at mass 28 (14C14N ions). The distribution of thymidine is heterogeneous along the chromosomes and a banding pattern can be observed on the pictures (SIMS-bands). The spatial resolution obtained with our scanning ion microprobe (the University of Chicago Scanning Ion Microprobe: UC-SIM) surpasses the one of autoradiography which is the common direct method of localization of labelled nucleosides. 1.
Article
High lateral resolution imaging (≈ 20 nm) secondary ion mass spectrometry (SIMS) can be achieved with liquid metal ion sources (LMIS). The use of scanning ion microprobes to explore the sensitivity and limitations of SIMS is discussed using examples from metallurgical and biological applications.
Book
Human hair is the subject of a remarkably wide range of scientific investigations. Its chemical and physical properties are of importance to the cosmetics industry, forensic scientists and to biomedical researchers. The fifth edition of this book confirms its position as the definitive monograph on the subject. Previous editions were recognized as “concise and thorough” (Journal of the American Chemical Society), “an invaluable resource” (Canadian Forensic Science Society Journal), and “highly recommended” (Textile Research Journal). Chemical and Physical Behavior of Human Hair is a teaching guide and reference volume for cosmetic chemists and other scientists in the hair products industry, academic researchers studying hair and hair growth, textile scientists and forensic specialists. Features of the Fifth Edition: Recent advances in the classification and characterization of the different proteins and genes in IF and keratin associated proteins in human hair are described. The mechanism and incidence of hair growth and loss and hair density vs. age of males & females are described for Asians, Caucasians and Africans in different scalp regions. Details of hair surface lipids and cuticle membranes provide a better understanding of the surface and organization of the CMC and its involvement in stress strain is presented. Recent evidence demonstrates a more bilateral structure in curly hair and a more concentric arrangement of different cortical proteins in straighter hair. SNPs involved in hair form (curl and coarseness) and pigmentation and genes in alopecia and hair abnormalities are described. The latest biosynthetic scheme for hair pigments and structures for these and the different response of red versus brown-black pigments to photodegradation is described. A new method for curvature on 2,400 persons from different countries and groups is used to assign curvature throughout this book. Additional data for age and effects on diameter, ellipticity, elastic modulus, break stress and other parameters are presented with much larger data sets featuring statistical analyses. Hair conditioning, strength, breakage, split ends, flyaway, shine, combing ease, body, style retention, manageability and feel parameters are defined and described. A new section of different life stages by age groups considering collective and individual changes in hair fiber properties with age and how these affect assembly properties.
Article
Synopsis The fracture behavior of Negroid hair was studied to clarify the causes of fiber breakage at low levels of extension. Visual observation and ellipticity measurements reveal frequent twists, with random reversals in direction and pronounced flattening which can lead to stress concentrations during tensile deformation. Simultaneous measurements of the effect of tensile load on extension and on axial angle of untwisting of specimens with a single twist indicate that failure at low extensions is due to the initiation of cracks at numerous flaws near the twists, which relieves torsional stresses in these regions. Extension at failure is higher in wet fibers, probably because plasticization relaxes these stresses. Scanning electron microscopy of fracture ends reveals a predominance of step fractures, indicating a large number of flaws, and a large proportion of fibrillated ends, reflecting poor cohesion between cortical cells. Fatiguing via a method devised to simulate the impact loading occurring during hair grooming appears to accentuate existing fiber damage and/or to reduce intercellular cohesion in the cortex, since fibrillated fracture ends predominate among fibers that fracture during fatiguing. The large number of premature failures in surviving fibers suggests that new damage may be initiated at the highest fatiguing loads and may also occur during combing and picking.
Article
2-N-Oleoylamino-octadecane-1,3-diol is a new synthetic ceramide. The process enables a four-step preparation of 2-amino-octadecane-1,3-diol (D,L-erythro/threo) and a five-step synthesis of 2-N-oleoylamino-octadecane-1,3-diol (D,L-erythro/threo). The latter compound is related to ceramide 2 according to the classification of Downing. This route of synthesis is rapid, reproducible and uses low-cost starting materials. The new ceramide was analysed as follows 1H, 13C, 15N NMR spectra afforded an unambiguous characterization of the structure; additionally, these three methods identified the threo and erythro isomers. 1H and 13CNMR permitted the measurement of the threo/erythro ratio (26.6/73.4 and 25.5/74.5, respectively). Chemical ionization mass spectrometry confirmed the expected mass of the pseudo-molecular ion (m/z = 566.5:[M + H]+) as well as the presence of different chain lengths other than the oleic moiety due to the fatty acid composition of the technical grade oleic acid used for the synthesis. Capillary gas chromatography measured the the threo/erythro ratio (23.5/76.5) which agrees with the 1H and 13C NMR data. Moreover, this method afforded the relative distribution of the different N-acylated chains. The properties of the new synthetic ceramide for the treatment of skin and hair were mainly assessed by two in vitro methods. The first measured the flux of water through lipid-extracted stratum corneum. The described ceramide showed high efficacy in decreasing water loss. The second recorded the friction coefficient of different types of hair: virgin, permanent-waved, and bleached. Treatment by the ceramide led to a strong decrease in this coefficient. This was particularly observed on unrinsed hair. These findings suggest two potential fields of application and beneficial contribution for the new ceramide: repairing the barrier to transepidermal water loss, and improving the surface properties of hair.
Article
The analysis of the lipids extracted from human hair by silica-gel-column liquid chromatography permitted an isolation of the fraction enriched in free ceramides. These were identified by GC/MS and are related to ceramide classes 2 and 5 in which the long-chain base was predominantly sphinganine. This differs from that observed in the free ceramides found within the stratum corenum. L'analyse des lipides de cheveux humains par extraction et chromatographie liquide sur colonne de silice a permis d'isoler la fraction enrichie en céramides libres. L'identification de ces céramides à l'aide du couplage GC/MS a montré qu'ils sont principalement apparentés aux céramides de classe 2 et 5. Ils sont caractérisés par la prédominance des bases saturées et plus particulièrement de la sphinganine. Leur distribution est différente de celle observée dans le cas des céramides libres du stratum corneum.
Article
Secondary ion mass spectroscopy (SIMS) was used to obtain images representing the intracellular distribution of molecules labelled with carbon 14. Deoxyadenosine labelled with carbon 14 was added to a cultured human fibroblast cell medium, and the intracellular distribution of this molecule was studied using three different SIMS instruments: the CAMECA IMS 3F and SMI 300 ion microscopes and the UC-HRL scanning ion microprobe. Carbon 14 distribution images obtained by this method show that deoxyadenosine U-C14 is present in the cytoplasm as well as the nucleus, with a higher concentration in the nucleoli. Our study clearly demonstrates that ion microscopy is well suited for carbon 14 detection and localization at the subcellular level, permitting a wide variety of microanalytical tracer experiments.
The performance of a new high resolution scanning ion microprobe (SIM) is elucidated with regard to imaging capabilities using the ion-induced secondary electron (ISE) or secondary ion (ISI) signals, and the mass-resolved signal from a secondary ion mass spectrometry (SIMS) system. The new instrument focuses a beam extracted from a liquid metal ion source (LMIS) to a range of spot sizes reaching the 20 nm level. The probe current (1.6 pA) available at this level of lateral resolution, which approaches the theoretical resolution limits of the SIMS method, is still adequate to obtain detailed isotopic maps for surfaces rich in the elements of low ionization potential (positive ISI), or high electron affinity (negative ISI). In addition to examples of high resolution ISE and ISI images of objects displaying sufficiently small topographic detail, mass spectra and isotopic maps are shown, testing both the lateral and depth resolution attained. The latter results belong with a program of interdisciplinary research applications of the new microprobe, which include studies of e.g., the monolayer lateral distribution of intercalant in SbCl5 intercalated graphite and of silicate minerals and iron distribution in sections of chondrules and their rims (components of chondrites, a class of stony meteorites). In the biomedical field, the new microprobe finds application in e.g., the study of human renal calculi and bone. Most promising is the use of stable isotope tracers (e.g., Ca44) to unravel the dynamics of bone mineralization, as thus far shown with the in-vitro culture of the skull bone of neonatal mice.
Article
Images of the distribution of a given nuclide in a section of biological tissue can be obtained at the microscopic level by "secondary-ion mass analysis." In this method, the images are formed by an ion-emission microscope wherein the specimen's atoms are progressively sputtered from the surface and the ions are selectively visualized by mass spectrometry according to their mass-to-charge ratios. Such images are obtained at the cost of the destruction of the specimen, which is progressively eroded at the rate of 1-10 atomic layers per second. The spatial resolution is better than 1 micrometer for an imaged area 250 micrometer in diameter and a section thickness of 1-2000 nm; thus, the analytical images are element distributions representative of 3-6000 atomic layers. Distributional images can be obtained for many nuclides, whether stable or radioactive, natural or artificially administered.
Article
Secondary ion mass spectrometry (SIMS) is a potentially valuable but not fully exploited technique for problems in biological research. It is valuable because of: (1) detection of all elements and isotopes from mass 1, hydrogen; (2) high sensitivity for physiologically important elements, Na, K, Mg, Ca; (3) ion imaging of elements in areas as large as 250 micrometers in diameter with a lateral resolution of 0.5 micrometers; (4) promising efforts at quantitation at levels as low as 0.1 mmol/kg; (5) ability to analyse sequential layers to form a three-dimensional analysis. The problems which complicate its use are primarily variations in ion emission, presence of poly-atomic interferences and tissue preparation. Examples are cited of SIMS analysis of biomineralization, botany, toxicology and physiology, mostly by ion imaging techniques. SIMS has not yet been fully exploited for any single biological problem. In particular, studies using isotope discrimination, quantitative analysis and depth profiling will enhance the usefulness of SIMS as a technique for biological research.
Article
African-American hair is unique due to its geometry--a kinky hair shaft with variations in diameter. This complex shaft structure creates the need for specialized grooming products and procedures to ensure that the hair maintains its cosmetic value.
Article
The meager data on normal hair density in humans have been gathered from a predominantly white population. Examination of scalp biopsy specimens from African Americans suggests that hair density in this group may be lower than in whites. This study was performed to quantify any differences between white and African American patients. A retrospective case series of subjects who had undergone a biopsy of clinically healthy scalp skin. The 4-mm punch biopsy specimens were sectioned, and all follicles contained within the specimens were counted at various levels (suprabulbar, isthmus, and infundibulum) to arrive at the number and type of hairs present. Outpatient clinic in a tertiary care medical center. A consecutive sample of 22 African American and 12 white patients with clinically healthy scalp skin specimens that were studied and compared with previously reported data. Patients' age and total number of follicles, terminal follicles, vellus follicles, terminal anagen hairs, and terminal telogen hairs. Total hair density (number of follicles per 4-mm punch biopsy specimen) and total number of terminal follicles and terminal anagen hairs were significantly lower in African Americans (P<.001) than in whites and in a previously reported, predominantly white, population. Hair density in African Americans is significantly lower than that in whites, which must be taken into consideration when evaluating a biopsy specimen from an African American patient. Data previously collected from white patients may not provide adequate guidance when evaluating scalp biopsy specimens from African Americans and could lead to an incorrect diagnosis.
Article
In Africa, the ancestral home of most African Americans, hair is viewed as the epitome of beauty. However, when Africans were brought to America as slaves, they were unable to care for their hair and skin adequately and were exposed to the predominant white culture, which valued straight hair and light skin. As a result, many African Americans lost self-esteem because of the characteristics of their hair and skin. In this article we examine the anatomic and physiologic features of African American hair and skin and typical African American hair and skin care practices. Common African American hair and skin disorders and their management are discussed. The goal of this article is to help primary care providers understand the special hair and skin care required for African American children (as well as other dark-skinned patients). With good patient education, understanding one's own hair and skin characteristics can also support positive self-esteem.
Hair follicle struc-ture, keratinization and the physical properties of hair
  • R P R Dawber
  • A G Messenger
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Recent advances in treating excessively curly hair
  • A N Syed
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