Morphology and histochemistry of human hair

Ja, Swift

doi:10.1007/978-3-0348-9223-0_4

Cited by 53 publications

(53 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By making use of established techniques of electron histochemistry appropriate to keratin fibres (Swift 1997b) it should also be possible to gain some information about their underlying chemical composition. In this context it is worth noting that Wolfram (1972) has examined transverse sections of wool fibres in the TEM close to their surfaces.…”

Section: Surface Striationsmentioning

confidence: 99%

“…Each cuticle sheet that is typically 0.5 µm thick is internally laminated and is separated from its neighbours by further lamellae (the socalled cell membrane complex). Much of our knowledge about the internal structure and chemistry of these components derives from transmission electron microscope (TEM) observations of stained fibre sections (Swift 1997b); the schematic diagram of Figure 3 summarises this structure. The A-layer and exocuticle consist of proteins highly toughened by disulphide and isopeptide crosslinking but, in sharp contrast to this, the endocuticle is of softer, relatively uncrosslinked proteins that swell on immersion in water.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Atomic force microscopy of human hair

Swift

Smith

2000

Scanning

View full text Add to dashboard Cite

Summary:The atomic force microscope (AFM) was used to investigate the surface architecture of the entire lengths of cleaned human head hairs. Many features previously seen with the scanning electron microscope (SEM) were identified. However, the AFM has provided much greater detail and, in particular, the hair's cuticular surfaces appear not to be as smooth as had been previously supposed. A consistent feature was of step discontinuities or "ghosts" on the scale surfaces. These delineated the original location of each overlying scale before its edge had been chipped away. There was a change in the longitudinal angular presentation of the surfaces about each ghost. This means the distal ends of each cuticle cell have been synthesised in the follicle to be thicker than where that same cuticle cell is bounded on both sides by other cuticle cells. The undamaged outer cuticular surfaces at the root end of each hair were covered everywhere by longitudinal ridges (striations). Where the hair surface was worn, the striations terminated at a scale edge ghost. The ridges were approximately 9 nm high and were in parallel array with a lateral repeat spacing of about 350 nm. The striations are evidently formed on the outer surface of each cuticle cell following earlier contact in the hair follicle with the inner root sheath. The study of stained transverse sections of hairs in the transmission electron microscope (TEM) is suggested as a means for throwing some light on the underlying structure and chemistry of the striations. Finally, our AFM studies have revealed that the surface of the freshly emergent hair gradually changes over a distance of about 20 mm and that the surface of the hair for most of its length is quite different from that near the root. This is likely to be of import to those engaged in the hair toiletries industry.

show abstract

Section: Surface Striationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Atomic force microscopy of human hair

Swift

Smith

2000

Scanning

View full text Add to dashboard Cite

show abstract

“…1 [1][2][3] . The structure of the cuticle CMC (cell membrane complex), which originates from the cell membrane, has the role of connecting cuticle cells with each other and provides a penetration route for moisture to reach the i nner part of the hair 4) .…”

Section: Introductionmentioning

confidence: 99%

The influence of hair bleach on the ultrastructure of human hair with special reference to hair damage

Imai

2011

Okajimas Folia Anat. Jpn.

View full text Add to dashboard Cite

Summary: The influence of human hair bleaching agents with different bleaching strength on the ultrastructure of human hair was studied using a transmission electron microscope (TEM) and an energy dispersive X-ray spectrometer equipped with TEM (EDS-TEM). Two kinds of bleaching agents were used: a lightener agent with a weak bleaching effect and a powder-bleach with a stronger bleaching effect.From the comparison of the bleaching properties obtained by the electronic staining of black and white hair samples, it was suggested that the permeability of hair was increased by bleaching, and there was an increase of the stainability of hair subjected to electronic staining. The bleaching action provoked the decomposition of melanin granules and the flow out of granular contents into the intermacrofibrillar matrix. Some metal elements were detected in the melanin granular matrix by EDS-TEM. As a result, the diffusion of metal elements into the intermacrofibrillar matrix promoted further damage to the hair by catalytic action with the hydrogen peroxide in the bleaching agents outside the melanin granules. Further study will lead us to the edge of the development of a new bleaching agent, which reacts only with melanin granules and causes the minimum of damage to outside the melanin granules.

show abstract

“…The common method for visualizing keratin groups in keratin fibers is with an aqueous solution of uranyl salts in which ionic binding of the uranyl ion occurs (Swift 1996).…”

Section: B2 the Problem Of Distinguishing Between Internal And Extmentioning

confidence: 99%

Controlling intake of uranium in the workplace: Applications of biokinetic modeling and occupational monitoring data

Leggett¹,

Eckerman²,

McGinn³

et al. 2012

View full text Add to dashboard Cite

This report provides methods to interpret and apply occupational uranium monitoring data. The methods are based on current international radiation protection guidance, current information on the chemical toxicity of uranium, and best available biokinetic models for uranium. Emphasis is on air monitoring data and three types of bioassay data: the concentration of uranium in urine; the concentration of uranium in feces; and the externally measured content of uranium in the chest. Primary Reference guidance levels for prevention of chemical effects and limitation of radiation effects are selected based on a review of current scientific data and regulatory principles for setting standards. Generic investigation levels and immediate action levels are then defined in terms of these primary guidance levels. The generic investigation and immediate actions levels are stated in terms of radiation dose and concentration of uranium in the kidneys. These are not directly measurable quantities, but models can be used to relate the generic levels to the concentration of uranium in air, urine, or feces, or the total uranium activity in the chest. Default investigation and immediate action levels for uranium in air, urine, feces, and chest are recommended for situations in which there is little information on the form of uranium taken into the body. Methods are prescribed also for deriving case-specific investigation and immediate action levels for uranium in air, urine, feces, and chest when there is sufficient information on the form of uranium to narrow the range of predictions of accumulation of uranium in the main target organs for uranium: kidneys for chemical effects and lungs for radiological effects. In addition, methods for using the information herein for alternative guidance levels, different from the ones selected for this report, are described. v FOREWORDThis report provides a detailed description of uranium biokinetics and bioassays applicable to evaluation of health risks from potential intakes in an occupational setting. The report addresses both the radiotoxicity and chemical (renal) toxicity of uranium. For reference occupational exposure scenarios, predictions of the time-dependent concentration of uranium in tissues and bioassay are based on biokinetic models currently recommended by the International Commission on Radiological Protection (ICRP). The ICRP's models and default assumptions for uranium were based primarily on data for human subjects exposed to uranium in controlled studies or in occupational or environmental settings. In addition, the ICRP considered an extensive database for uranium in laboratory animals. Sensitivity studies examine the robustness of these models and assumptions to ensure that radiation doses and accumulation of uranium in the kidneys are not underestimated. For example, analyses indicate that a default 5 µm activity median aerodynamic diameter particle size can lead to an underestimation of radiation dose as well as the concentration of uranium in the kidneys if inhal...

show abstract

Morphology and histochemistry of human hair

Cited by 53 publications

References 33 publications

Atomic force microscopy of human hair

Atomic force microscopy of human hair

The influence of hair bleach on the ultrastructure of human hair with special reference to hair damage

Controlling intake of uranium in the workplace: Applications of biokinetic modeling and occupational monitoring data

Contact Info

Product

Resources

About