Feasibility study of in vivo fingernail dosimetry by electron paramagnetic resonance / 中华放射医学与防护杂志

Objective To explore the feasibility of EPR in vivo fingernail dosimetry to address the difficulty in separating mechanically induced signals from fingernail EPR dosimetry for need of nuclear medical emergency aid.Methods Using the specially designed EPR in vivo measurement system,uncut fingernails were measured to obtain the characteristics of EPR signal without mechanically induced signals.The in vivo fingernail experiment was carried out to evaluate the impact of in vivo condition on the spectra.Actual in vivo measurement experiment was conducted to evaluate the interference of the in vivo condition on EPR spectra.Results The background signal distribution of uncut fingernails was obtained and background signals had no significant difference between male and female(P＞0.05).The dose response curve in the range of 2-10 Gy was established,and the half-life of the fingernail radiation-induced signal was approximately 5 d.The water treatment combined with temperature-changing was established for restoring the background signal.EPR signal obtained after restoring treatment has no significant difference with background signal (P＞ 0.05).The EPR spectra of in vivo fingernails were obtained.Conclusions The EPR spectra without mechanically induced signals can be acquired by this method.The feasibility of the in vivo fingernail EPR dosimetry is preliminarily verified.

Biological Markers of Fluoride Exposure: A Review Article.

Biological markers or biomarkers act as indicators that signal events in biological systems (human body) or samples. The concept of biological markers of fluoride exposure came to prominence in the 1994 Technical Report on Fluorides and Oral Health. The WHO stated that a fluoride biomarker was of value primarily for identifying and monitoring deficient or excessive intakes of biologically available fluoride. Knowledge of fluoride availability during pre-eruptive periods of tooth formation allows assessment of the potential for later development of fluorosis while knowledge of its availability post-eruptively provides a guide to the potential level of protection from caries. Contemporary biological markers assess present, or very recent, exposure to fluoride, fluoride concentrations in blood, bone surface, saliva, milk, sweat, and urine have been considered. The most studied recent biomarkers are nails and hair. Both can be non-invasively obtained, although collection of nails is more accepted by the subjects. During the last two decades, there has been a rapid expansion in the availability and use of biomarkers in health care such that they now occupy a central position in the armamentarium of the clinician for screening, diagnosis, and management of the disease. Here, an attempt is made to review biomarkers of fluoride exposure.

Squamous Cell Carcinoma and Bowen Disease in Nail Apparatus / 대한피부과학회지

Squamous cell carcinoma of the nail apparatus is a rare phenomenon. Because of its indolent course and similar presentation to other benign conditions, correct diagnosis in the early stages is practically difficult. We here report two cases of periungual squamous cell carcinoma and squamous cell carcinoma in situ (Bowen's disease). These cases emphasize the importance of extra vigilance and high suspicion when facing intractable atypical lesions on the fingers. Repetitive biopsy with exploratory nail plate extraction should be considered to acquire appropriate specimens, which is critical for early and correct diagnosis.

Growth Disturbance of Nail Plate after a Metacarpal Fracture: Four Cases Report

The fingernail is damaged and deformed by various causes such as crushing, laceration, avulsion injury, infection, tumor and personal habit. The growth disturbance of nail plate may be caused by systemic diseases or trauma without a direct injury of the fingernail and is usually found in accident. We experienced abnormal growth of nail plate in four patients with previous fractures of metacarpal bone. At about 8 weeks after trauma, a swelling and tenderness on the eponychium and a growth disturbance of affected nail plates occurred. All affected fingernails were treated with the nail extraction. The authors report four cases of growth disturbance of nail plates which obtained the satisfactory results by using the nail extraction.

A study on the correlation between urinary fluoride/creatinine ratio, fluoride concentration of drinking water, urine and fingernail in preschool children / 대한구강보건학회지

OBJECTIVES: This study aimed to confirm the efficacy of the urinary fluoride concentration/creatinine ratio for monitoring fluorine intake in fluoridated and non-fluoridated communities. METHODS: The correlations among the fluoride concentration in drinking water and that in the urine and fingernails of 52 preschool children (age, 60-72 months) from fluoridated and non-fluoridated communities were analyzed. RESULTS: The urinary fluoride concentration/creatinine ratio had a relatively high correlation with the fluoride concentration in drinking water (Pearson's correlation coefficient, 0.606; P0.05). CONCLUSIONS: The findings of this study suggest that the urinary fluoride concentration/creatinine ratio in children can be utilized as an index for monitoring excess fluoride intake in fluoridated communities.

Fingernail may not be a reliable biomarker of fluoride body burden from dentifrice

Fingernail has been suggested as a biomarker of fluoride (F) body burden, but there is no consensus if it would be a reliable indicator of F exposure from dentifrice. Therefore, the present study was conducted to investigate if fingernails would have sensitivity to detect F exposure from dentifrice in young children. Twenty-three 1-3-year-old children living in the city of Piracicaba (0.72 ppm F in water), Brazil, were enrolled in two phases of different F exposure: in phase A (1st to 11th week), they were exposed to the combination of F from diet (solids and liquids) and dentifrice (1,500 µg F/g as MFP), and in phase B (12th to 29th week), only to F from diet (the use of F dentifrice was interrupted). Fingernails were weekly clipped during 35 weeks for F determination. F intake from diet and dentifrice in each phase was also determined. Both analyses were made with ion-specific electrode. F intake (Mean ± SD) was significantly higher (p<0.01) when the children were exposed to F from diet+dentifrice than only to F from diet (0.086 ± 0.032 and 0.040 ± 0.009 mg F/day/kg body weight, respectively). However, F concentrations in nails collected during the whole experimental period of 35 weeks presented great variation with no trend of decreasing after F dentifrice intake interruption. The findings suggest that fingernail may not be a reliable F biomarker of body burden from dentifrice.

As unhas têm sido consideradas um biomarcador para a exposição ao flúor (F), mas não há consenso se é um indicador confiável para exposição ao F a partir do dentifrício. Vinte e três crianças, com idade entre 1 a 3 anos, moradoras de Piracicaba (0,72 ppm F na água), Brasil, foram submetidas a duas fases de diferentes exposição ao F: fase A (1a a 11a semanas), as crianças foram expostas à combinação de F a partir da dieta (sólidos e líquidos) e dentifrício (1500 µg F/g como MFP); e na fase B (12ª a 29ª semanas), apenas ao F da dieta, uma vez que usaram dentifrício não fluoretado. As unhas das mãos foram coletadas semanalmente durante 35 semanas para determinação de F. A exposição ao F a partir da dieta e dentifrício foi também determinada. Ambas análises foram feitas com eletrodo específico para F. A exposição ao F foi significativamente maior (p<0,001) quando as crianças foram expostas ao F da dieta + dentifrício que ao F da dieta (0,086 ± 0,032 e 0,040 ± 0,009 mg F/kg corpóreo/dia, respectivamente). Entretanto, a concentração de F nas unhas coletadas durante todo o período experimental não diminuiu após a interrupção da ingestão do F a partir do dentifrício. Os resultados sugerem que as unhas das mãos não são um biomarcador confiável para refletir a exposição ao F pelo dentifrício.

A Case of White Superficial Onychomycosis / 대한피부과학회지

Clinical types of onychorpycosis, consist of distal subungual orychomycosis, white superficial onychomycosis, proximal subongual onychomycosis and candidal onychomycosis. White superficial onychomycosis aippears as white, sharply outlined areas on the surfaces of toenails. The fingernails are not affected. Trichophyton mentogrophytes, rarely Trichophyton rubrm, is the causa ive dermatophytes. The auther reports a case of white superficial onychomycosis of the fingernail caused by T. rubrm.