Abstract:The effect of UV-and 137 Cs gamma radiation on the structural and chemical integrity of human hair was studied to determine the feasibility of using human hair as a non-invasive biomarker of radiation exposure to ionized gamma-and non-ionized UV-radiation. Steady state tryptophan (Trp) fluorescence and chemical analytical methods were used to evaluate the molecular integrity of Trp fluorophores and SH-groups in hair proteins and to assess the radiation induced damage quantitatively. It was found that human hai… Show more
“…The prediction of a flat dose-response at high gamma radiation doses 39 of up to 200 Gy is not found in present work, the tryptophan being incompletely damaged or depleted. The damage due to gamma irradiation has been reported to be significantly reduced in dehydrated hair with 10–30% of water content relative to other biological samples such as viable epidermis of the skin with 70% water content 39 – 41 . Figure 6 PL spectra of hair samples subjected to gamma irradiation doses ranging from 0 to 200 Gy.…”
Section: Resultscontrasting
confidence: 87%
“…Of note is that the tryptophan concentration in hair varies with age (being greater in first few years of life, 1–5 years, and highest in aging subjects 61 years), sex (higher in males), and hair colour (highest in white and grey hair, followed by black and brown hair) 38 . Figure 7 c shows the dose-response curve for doses of 10 Gy and beyond, fitted to a logarithmic function, in which the photoluminescence from the hair decreases with increasing dose ( ), evidence of hair damage being associated with the reaction of free radicals and direct deposition of energy 39 . Conversely to the situation presented for irradiations for doses from 0 to 10 Gy, a downward trend in hair fluorescence for the same dose range was observed 39 , delivered in this case by (662 keV; LET ), obtained at an emission wavelength of 335 nm.…”
Section: Resultsmentioning
confidence: 99%
“…Figure 7 c shows the dose-response curve for doses of 10 Gy and beyond, fitted to a logarithmic function, in which the photoluminescence from the hair decreases with increasing dose ( ), evidence of hair damage being associated with the reaction of free radicals and direct deposition of energy 39 . Conversely to the situation presented for irradiations for doses from 0 to 10 Gy, a downward trend in hair fluorescence for the same dose range was observed 39 , delivered in this case by (662 keV; LET ), obtained at an emission wavelength of 335 nm. The greater LET of the gamma rays is suggested to result in a greater degree of damage.…”
Preliminary study has been made of black human hair, carbon concentration of some 53%, a model in examining the potential of hair of the human head in retrospective and emergency biodosimetry applications, also offering effective atomic number near to that of water. The hair samples were exposed to $$^{60}$$
60
Co gamma rays, delivering doses from 0 to 200 Gy. Structural alterations were observed, use being made of Raman and photoluminescence (PL) spectroscopy. Most prominent among the features observed in the first-order Raman spectra are the D and G peaks, appearing at 1370 $${{\pm }} 18\,{\hbox {cm}}^{-1}$$
±
18
cm
-
1
and 1589 $${{\pm }} 11\,{\hbox {cm}}^{-1}$$
±
11
cm
-
1
respectively, the intensity ratio $${{{I}}}_{{{D}}}{{/}}{{{I}}}_{{{G}}}$$
I
D
/
I
G
indicating dose-dependent defects generation and annealing of structural alterations. The wavelengths of the PL absorption and emission peaks are found to be centred at $$592.3 \pm 12.5$$
592.3
±
12.5
nm and $$1077.4 \pm 7.3$$
1077.4
±
7.3
nm, respectively. The hair samples mean band gap energy ($${{{E}}}_{{{g}}}$$
E
g
) post-irradiation was found to be $$2.10 \pm 0.04$$
2.10
±
0.04
eV, of the order of a semiconductor and approximately two times the $${{{E}}}_{{{g}}}$$
E
g
of other carbon-rich materials reported via the same methodology.
“…The prediction of a flat dose-response at high gamma radiation doses 39 of up to 200 Gy is not found in present work, the tryptophan being incompletely damaged or depleted. The damage due to gamma irradiation has been reported to be significantly reduced in dehydrated hair with 10–30% of water content relative to other biological samples such as viable epidermis of the skin with 70% water content 39 – 41 . Figure 6 PL spectra of hair samples subjected to gamma irradiation doses ranging from 0 to 200 Gy.…”
Section: Resultscontrasting
confidence: 87%
“…Of note is that the tryptophan concentration in hair varies with age (being greater in first few years of life, 1–5 years, and highest in aging subjects 61 years), sex (higher in males), and hair colour (highest in white and grey hair, followed by black and brown hair) 38 . Figure 7 c shows the dose-response curve for doses of 10 Gy and beyond, fitted to a logarithmic function, in which the photoluminescence from the hair decreases with increasing dose ( ), evidence of hair damage being associated with the reaction of free radicals and direct deposition of energy 39 . Conversely to the situation presented for irradiations for doses from 0 to 10 Gy, a downward trend in hair fluorescence for the same dose range was observed 39 , delivered in this case by (662 keV; LET ), obtained at an emission wavelength of 335 nm.…”
Section: Resultsmentioning
confidence: 99%
“…Figure 7 c shows the dose-response curve for doses of 10 Gy and beyond, fitted to a logarithmic function, in which the photoluminescence from the hair decreases with increasing dose ( ), evidence of hair damage being associated with the reaction of free radicals and direct deposition of energy 39 . Conversely to the situation presented for irradiations for doses from 0 to 10 Gy, a downward trend in hair fluorescence for the same dose range was observed 39 , delivered in this case by (662 keV; LET ), obtained at an emission wavelength of 335 nm. The greater LET of the gamma rays is suggested to result in a greater degree of damage.…”
Preliminary study has been made of black human hair, carbon concentration of some 53%, a model in examining the potential of hair of the human head in retrospective and emergency biodosimetry applications, also offering effective atomic number near to that of water. The hair samples were exposed to $$^{60}$$
60
Co gamma rays, delivering doses from 0 to 200 Gy. Structural alterations were observed, use being made of Raman and photoluminescence (PL) spectroscopy. Most prominent among the features observed in the first-order Raman spectra are the D and G peaks, appearing at 1370 $${{\pm }} 18\,{\hbox {cm}}^{-1}$$
±
18
cm
-
1
and 1589 $${{\pm }} 11\,{\hbox {cm}}^{-1}$$
±
11
cm
-
1
respectively, the intensity ratio $${{{I}}}_{{{D}}}{{/}}{{{I}}}_{{{G}}}$$
I
D
/
I
G
indicating dose-dependent defects generation and annealing of structural alterations. The wavelengths of the PL absorption and emission peaks are found to be centred at $$592.3 \pm 12.5$$
592.3
±
12.5
nm and $$1077.4 \pm 7.3$$
1077.4
±
7.3
nm, respectively. The hair samples mean band gap energy ($${{{E}}}_{{{g}}}$$
E
g
) post-irradiation was found to be $$2.10 \pm 0.04$$
2.10
±
0.04
eV, of the order of a semiconductor and approximately two times the $${{{E}}}_{{{g}}}$$
E
g
of other carbon-rich materials reported via the same methodology.
“…It has been demonstrated that exposure to ionizing gamma radiation cleaves the disulfide bonds and decomposes amino acids in keratin, cysteine hair leading to the formation of cysteic acid, CySO3 H.The numerous disulfide bonds formed by cysteine are responsible for the great stability of keratin and both keratin and cysteine are very reactive, can easily be reduced, oxidized, and hydrolyzed . [13] It is worth to mention that both of heat and irradiation produced decomposition of tryptophan residues to kynurenine type oxidation products. [14][15][16] Stress of heat and/or irradiation stimulated the pro-inflammatory cytokines, [17] which can further activate kynurenine pathway through the induction of indole amine 2, 3dioxygenase and tryptophan 2, 3-dioxygenase enzymes.…”
The objective of the submitted work was to assess the effect of hot air and/ or gamma irradiation following the application of a protein hair conditioner on the skin hygiene. Ninety six albino rats were employed in this work, one half of them were females and the other half was males. The animals were divided into eight main groups; each included six males and six females. Rats in group 1 (control) and they were fed free on normal food and water. Rats of groups 2, 3 and 4were rubbed with protein conditioner for one, two and three times, respectively, every so often was separated by seven days duration. Following every treatment, the rats were exposed to hot air from a blow dryer (95 ᵒ C) for one minute. Rats in groups 5, 6 and 7 were treated in the same manner and after one week, they exposed to a single dose whole body gamma irradiation (10 Gy). Rats in group 8 were treated once with protein conditioner and they were directly exposed to the same irradiation dose. Post one week of irradiation, all rats were anesthetized and blood samples were collected for biochemical analyses, while shaven skin cuts from the centre protein applying area for histological examinations. Morphological observations revealed decreases in hair density, alopecia and skin ulcer. Whereas, the biochemical results indicated that serum collagen I (Col. I) contents decreased while heat shock protein (HSP70) concentrations increased as treatment repetitions. The level of vascular endothelial growth factor (VEGF) exhibited inconsistence trend. Histopathological observations confirmed the morphological findings particularly the skin ulcer phenomenon.In conclusion, there is no protein -based hair conditioner products that can be considered completely safe. It is worth to state that, it's time to give serious consideration for stopping these treatments. Even if there are no negative effects as yet are noticed, it doesn't mean that human is immune but cumulative exposure can increase the risks.
EPR spectroscopy was used to monitor formation of free radicals in human hair upon UV irradiation. While the EPR spectra of brown hair were dominated by melanin signal, those of white hair were keratin-derived. The decay of UV induced keratin radicals was enhanced at increased ambient humidity. We argue that at higher humidity the swollen hair provides a more liquid-like environment, and higher molecular mobility in this environment leads to faster radical reactions. This interpretation is consistent with the increased UV-triggered protein damage in hair at high humidity as demonstrated by the protein loss, MALDI-TOF and FT-IR data.
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