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2.
J Pharmacol Toxicol Methods ; 88(Pt 1): 46-55, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28688881

RESUMO

In vivo phototoxicity studies are important to predict drug-induced phototoxicity in humans; however, a standard methodology has not established. To determine differences in sensitivity to drug-induced phototoxicity among various skin sites, we evaluated phototoxic reactions in the back and abdominal skin of female Sprague-Dawley rats orally dosed with phototoxic drugs (pirfenidone, 8-methoxysoraren, doxycycline, and lomefloxacin) or a non-phototoxic drug (gatifloxacin) followed by solar-simulated light irradiation comprising 18J/cm2 ultraviolet A. Tissue reactions were evaluated by macroscopic and microscopic examination and immunohistochemistry for γ-H2AX, and tissue concentrations of pirfenidone, doxycycline, and lomefloxacin were measured by tandem mass spectrometry. In addition, the thicknesses of the skin layers at both sites were measured in drug-naïve rats. The abdominal skin showed more severe reactions to all phototoxic drugs than the back skin, whereas the minimal erythema dose in drug-naïve rats and skin concentrations of each drug were comparable between the sites. Furthermore, histopathological lesions and γ-H2AX-positive cells in the abdominal skin were detected in deeper layers than in the back skin. The stratum corneum and dermis in the abdominal skin were significantly thinner than in the back skin, indicating a difference in the depth of light penetration and potentially contributing to the site differences observed in sensitivity to phototoxicity. Gatifloxacin did not induce any phototoxic reactions at either site. In conclusion, the abdominal skin is more sensitive to drug-induced phototoxicity than the back skin and may represent a preferable site for irradiation in this rat phototoxicity model.


Assuntos
Abdome/patologia , Dorso/patologia , Dermatite Fototóxica/patologia , Pele/patologia , Luz Solar/efeitos adversos , Testes de Toxicidade Aguda/métodos , Abdome/efeitos da radiação , Administração Oral , Animais , Dorso/efeitos da radiação , Dermatite Fototóxica/etiologia , Modelos Animais de Doenças , Doxiciclina/farmacologia , Feminino , Fluoroquinolonas/farmacologia , Gatifloxacina , Histonas/metabolismo , Metoxaleno/farmacologia , Fosfoproteínas/metabolismo , Piridonas/farmacologia , Ratos , Ratos Sprague-Dawley , Índice de Gravidade de Doença , Pele/efeitos da radiação , Espectrometria de Massas em Tandem , Testes de Toxicidade Aguda/instrumentação
3.
Clin Oral Investig ; 21(4): 1327-1333, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27324474

RESUMO

PURPOSE: The aim of this study was to compare the dose at skin level at five significant anatomical regions for panoramic radiography devices with and without lead apron by means of a highly sensitive dosimeter. MATERIALS AND METHODS: A female RANDO-phantom was exposed in five different digital panoramic radiography systems, and the dose at skin level was assessed tenfold for each measurement region by means of a highly sensitive solid-state-dosimeter. The five measurement regions selected were the thyroid, both female breasts, the gonads, and a central region in the back of the phantom. For each panoramic machine, the measurements were performed in two modes: with and without a commercial lead apron specifically designed for panoramic radiography. Reproducibility of the measurements was expressed by absolute differences and the coefficient of variation. Values between shielded and unshielded doses were pooled for each region and compared by means of the paired Wilcoxon tests (p ≤ 0.05). RESULTS: Reproducibility as represented by the mean CV was 22 ± 52 % (median 2.3 %) with larger variations for small dose values. Doses at skin level ranged between 0.00 µGy at the gonads and 85.39 µGy at the unshielded thyroid (mean ± SD 15 ± 24 µGy). Except for the gonads, the dose in all the other regions was significantly lower (p < 0.001) when a lead apron was applied. Unshielded doses were between 1.02-fold (thyroid) and 112-fold (at the right breast) higher than those with lead apron shielding (mean: 14-fold ± 18-fold). CONCLUSION: Although the doses were entirely very low, we observed a significant increase in dose in the radiation-sensitive female breast region when no lead apron was used. Future discussions on shielding requirements for panoramic radiography should focus on these differences in the light of the linear non-threshold (LNT) theory which is generally adopted in medical imaging.


Assuntos
Proteção Radiológica/instrumentação , Radiografia Panorâmica , Pele/efeitos da radiação , Dorso/efeitos da radiação , Mama/efeitos da radiação , Feminino , Gônadas/efeitos da radiação , Humanos , Técnicas In Vitro , Masculino , Modelos Anatômicos , Doses de Radiação , Reprodutibilidade dos Testes , Glândula Tireoide/efeitos da radiação
4.
Photochem Photobiol Sci ; 14(2): 481-7, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25410723

RESUMO

Previous studies on the association of solar lentigines with ultraviolet radiation (UVR) exposure have been based on retrospective questionnaires about UVR exposure. We aimed to investigate the association between solar lentigines and UVR exposure in healthy individuals using objective measurements, and to investigate the association between solar lentigines and cutaneous malignant melanoma (CMM). Forty-eight patients with CMM and 48 controls that matched the patients individually by age, sex, constitutive skin type and occupation participated. Solar lentigines on the shoulders and upper back were counted and graded into 3 categories using black light photographs to show sun damage. Current UVR exposure in healthy controls was assessed by personal electronic UVR dosimeters that measured time-related UVR and by corresponding exposure diaries during a summer season. Sunburn history was assessed by interviews. Among controls, the number of solar lentigines was positively associated with daily hours spent outdoors between noon and 3 pm on holidays (P = 0.027), days at the beach (P = 0.048) and reported number of life sunburns (P < 0.001). Compared with matched controls CMM patients had a higher number of solar lentigines (P = 0.044). There was a positive association between CMM and higher solar lentigines grade; Category III versus Category I (P = 0.002) and Category II versus Category I (P = 0.014). Our findings indicate that solar lentigines in healthy individuals are associated with number of life sunburns, as well as time spent outdoors around noon on holidays and beach trips during a summer season, most likely reflecting past UVR exposure, and that solar lentigines are a risk factor for CMM.


Assuntos
Dorso/patologia , Exposição Ambiental/efeitos adversos , Lentigo/patologia , Melanoma/patologia , Ombro/patologia , Raios Ultravioleta , Adulto , Idoso , Dorso/fisiopatologia , Dorso/efeitos da radiação , Estudos de Casos e Controles , Equipamentos e Provisões Elétricas , Feminino , Humanos , Entrevistas como Assunto , Lentigo/fisiopatologia , Masculino , Registros Médicos , Melanoma/fisiopatologia , Pessoa de Meia-Idade , Radiometria , Índice de Gravidade de Doença , Ombro/fisiopatologia , Ombro/efeitos da radiação , Neoplasias Cutâneas , Fenômenos Fisiológicos da Pele , Luz Solar/efeitos adversos , Fatores de Tempo
5.
Ann Plast Surg ; 67(4): 352-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21629107

RESUMO

Flaps with adequate blood supply are the best methods for covering the radiation ulcer defect. Our report is on the use of the lateral intercostal artery perforator-based reversed thoracodorsal artery (TA) flap for treatment of a patient with a large radiation ulcer on his lower back. When the flap was elevated, we could use an infrared imaging device to confirm the location of the perforators and demonstrate the communication with the TA. The communication between the main TA and the lateral intercostal artery perforator has previously not been reported in the literature in detail. We used an indocyanine green dye and infrared imaging device to seek out the perforators and their communication. Even in a small communication, we were able to use the device to check the perforators and to elevate this flap with more assurance, without having to be concerned about further radiation exposure for the patient.


Assuntos
Dorso/efeitos da radiação , Lesões por Radiação/cirurgia , Procedimentos Cirúrgicos Reconstrutivos/métodos , Retalhos Cirúrgicos , Úlcera/cirurgia , Idoso , Dorso/cirurgia , Humanos , Raios Infravermelhos , Região Lombossacral , Masculino , Microcirurgia/métodos , Retalhos Cirúrgicos/irrigação sanguínea
6.
Clin Exp Dermatol ; 30(4): 337-9, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15953061

RESUMO

In most dermatology centres where phototesting is performed, the starting dose is calculated as a proportion of the minimal erythema dose (MED). Previous studies have found significant differences in MED readings between forearm and back skin with both broadband and narrowband (NB) UVB. Our objective was to compare MEDs obtained from three body sites, the forearm, back and abdomen, to see if there was a significant difference in individuals. We recruited 20 healthy volunteers who were exposed to our standard dose series for phototesting with NB-UVB to three body sites: forearm, back and abdomen. MEDs were assessed 24 h post exposure. The median MED for the abdomen was 0.79 J/cm2, the back 0.95 J/cm2 and the arm 1.11 J/cm2. Friedman's analysis of variance by ranks showed that these differences were significant (P = 0.003). There was no correlation between skin type and MED for any of the three anatomical sites. Our results support phototesting for all patients prior to treatment with NB-UVB. Furthermore, we have shown that the abdomen is the anatomical site of choice for phototesting, as this will result in a reduced risk of burning episodes.


Assuntos
Eritema/etiologia , Radiodermatite/etiologia , Terapia Ultravioleta/efeitos adversos , Abdome/efeitos da radiação , Adulto , Idoso , Dorso/efeitos da radiação , Feminino , Antebraço/efeitos da radiação , Humanos , Masculino , Pessoa de Meia-Idade , Radiodermatite/patologia , Dosagem Radioterapêutica , Testes Cutâneos/métodos
7.
Bioelectromagnetics ; 24(2): 75-81, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12524673

RESUMO

Two groups of SENCAR mice were treated with a single dose of carcinogen and then, for 23 weeks, with a chemical tumor promoter to induce skin tumors. During this period, one group was coexposed to a 2 mT power frequency (60 Hz) magnetic field, while the other was exposed to sham conditions. Application of the tumor promoter ceased after 23 weeks, but the exposure to sham conditions or magnetic fields continued for an additional 29 weeks. No difference was found between the two groups of mice in terms of the incidence of total tumors (P =.297) or squamous cell carcinomas (SSC) (P =.501). In summary, there was no evidence to support the hypotheses that 60 Hz magnetic fields (MF) can influence the development of either papillomas or SSC under our defined experimental conditions. The overall results add to previous animal studies that find no association between exposure to 60 Hz MF and the incidence of benign or malignant tumors.


Assuntos
Carcinoma de Células Escamosas/etiologia , Campos Eletromagnéticos/efeitos adversos , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Cutâneas/etiologia , Pele/efeitos da radiação , 9,10-Dimetil-1,2-benzantraceno , Animais , Dorso/efeitos da radiação , Carcinógenos , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/patologia , Cocarcinogênese , Tolerância a Medicamentos/efeitos da radiação , Eletricidade , Camundongos , Camundongos Endogâmicos SENCAR , Neoplasias Induzidas por Radiação/patologia , Tolerância a Radiação/efeitos dos fármacos , Valores de Referência , Pele/efeitos dos fármacos , Pele/patologia , Neoplasias Cutâneas/induzido quimicamente , Neoplasias Cutâneas/patologia , Acetato de Tetradecanoilforbol
9.
Br J Dermatol ; 139(5): 811-4, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9892946

RESUMO

A device for phototesting patients prior to narrowband phototherapy is described. One hundred and fifty patients (130 with psoriasis and 20 with eczema) of skin types I-IV were phototested on the forearm and 22 on both forearm and back. The minimal erythema dose (MED) was judged visually 24 h after irradiation, and in those patients who were tested at two body sites, objective measurement of the erythema was made using a reflectance instrument. The MED values on the arm showed a fivefold range. There was no significant association between skin type and MED. The MED values on the arm were significantly higher than those measured on the back, although the differences were small in the majority of cases. No significant difference was found between the slopes of the dose-response curves measured on the arm and on the back.


Assuntos
Dermatite Atópica/radioterapia , Psoríase/radioterapia , Terapia Ultravioleta/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Dorso/efeitos da radiação , Relação Dose-Resposta à Radiação , Eritema/etiologia , Antebraço/efeitos da radiação , Humanos , Pessoa de Meia-Idade , Lesões por Radiação/etiologia , Radiometria/métodos , Dosagem Radioterapêutica , Terapia Ultravioleta/efeitos adversos
10.
Photochem Photobiol ; 58(5): 643-7, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8284319

RESUMO

The Philips TL01 narrow-band (311-313 nm) fluorescent lamp provides effective phototherapy for psoriasis and atopic eczema while emitting less erythemogenic radiation than conventional broad-band (e.g. Philips TL12; 270-350 nm) sources. We studied the potency of TL01 and TL12 radiation to induce edema and sunburn cells (SBC) and to photoisomerize naturally occurring trans-urocanic acid (UCA) to cis-UCA in hairless mouse skin. Cis-UCA has immunosuppressive properties and is a putative mediator of UV-induced suppression of immune responses. For each source, there was UV dose dependence for all three responses. Within the dose ranges used, the potency ratio of TL12:TL01 radiation to induce equivalent edema and SBC was about 6:1. However, the potency ratio to induce cis-UCA was less than 2.3:1. Therefore, at a given level of edema or SBC induction, TL01 was more efficient than TL12 at UCA photoisomerization. The TL01 induction of immunomodulating cis-UCA, while causing minimal skin injury, may relate to the therapeutic efficacy of this source in skin conditions with an immunological component.


Assuntos
Edema , Fototerapia/instrumentação , Pele/efeitos da radiação , Queimadura Solar , Ácido Urocânico/química , Albinismo , Animais , Dorso/efeitos da radiação , Relação Dose-Resposta à Radiação , Orelha/efeitos da radiação , Feminino , Isomerismo , Camundongos , Camundongos Pelados , Pele/citologia , Raios Ultravioleta
11.
Int J Radiat Oncol Biol Phys ; 18(4): 879-82, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1691161

RESUMO

R1H tumors were irradiated with a single dose of 15 Gy X rays using varying sizes of treatment fields. Damage to tumor cells and tumor stroma was determined separately by analysis of growth delay to ten times treatment volume (GD10vo) and net growth delay. GD10vo comprises irradiation effects on tumor parenchymal cells and on tumor stroma, whereas net growth delay only measures effects on tumor parenchymal cells. Stromal damage was observed to increase with increasing field size; the effect on the tumor parenchymal cells, however, was independent of the field size. An increase of GD10vo of 13 days per cm increase of field size diameter was observed. From this the velocity of neovascularization of the irradiated tumor bed was calculated to be 0.30 to 0.38 mm per day.


Assuntos
Rabdomiossarcoma/radioterapia , Animais , Dorso/irrigação sanguínea , Dorso/efeitos da radiação , Cinética , Masculino , Transplante de Neoplasias , Neovascularização Patológica , Ratos , Rabdomiossarcoma/patologia
12.
Z Erkr Atmungsorgane ; 148(2): 185-8, 1977.
Artigo em Alemão | MEDLINE | ID: mdl-919625

RESUMO

Radiation doses to hands, gonads, head and dorsum received by staff carrying out bronchological X-ray examinations have been measured using LiF/teflon dosimeters. Because of the relatively high dorsal doses, it is important for the medical personnel to face the patient exclusively with the radiation protected foreside.


Assuntos
Departamentos Hospitalares , Radiação , Serviço Hospitalar de Radiologia , Dorso/efeitos da radiação , Broncografia , Broncoscopia , Exposição Ambiental , Alemanha Oriental , Gônadas/efeitos da radiação , Mãos/efeitos da radiação , Cabeça/efeitos da radiação , Ocupações em Saúde , Humanos , Doses de Radiação , Proteção Radiológica
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