RESUMEN
The distribution of epidermal growth factor receptors (EGFR) and receptors for steroid hormones--androgens (RA), estrogens (RE) and glucocorticoids (RG) was studied in malignant (MT) and benign (BT) tumors in children. The distribution and mean levels of some receptors in normal tissues were statistically different from those in MT and BT. The absence of RA and the high levels of RE > 20 fmol/mg protein and RG > 50 fmol/mg protein were typical of MT whereas BT might be characterized by the high levels of EGFR > 300 fmol/mg protein. In MT with and without metastases, the following parameters were significantly different (p < 0.001): RG = 81 and 18 fmol/mg, respectively, and EGFR = 160 and 58 fmol/mg protein, respectively. The most informative parameters for distinguishing BT and MT appeared to be RA (0.086 dit), RE (0.043 dit) and EGFR (0.037 dit). The most sensitive parameter for MT was RG, which, however, is least specific; RA is most specific (75%). The optimal amount of three parameters: RA + RE + EGFR (88.4%) is most exact for differential diagnosis.
Asunto(s)
Corticoesteroides/metabolismo , Receptores ErbB/metabolismo , Neoplasias/diagnóstico , Neoplasias/metabolismo , Adolescente , Factores de Edad , Niño , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Valor Predictivo de las PruebasRESUMEN
The radioligand technique was used to study the amount of epidermal growth factor receptors (EGFR) in malignant and benign tumors in 32 children aged 8 months to 17 years. The membranous fraction of 11 of the 32 tumors studied showed EGFR equal to 10.1 to 1327 fmol/mg (163.0 +/- 117.5 fmol/mg, median 38.0 fmol/mg). The greatest amount of EGFR was found in breast fibroadenomas. There was no clear relationship of the frequency and level of EGFR expression to a nosological tumor entity in children. A possible role of the EGFR system in tumors in children is discussed.
Asunto(s)
Receptores ErbB/sangre , Neoplasias/sangre , Adolescente , Biomarcadores de Tumor/sangre , Niño , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Lactante , Masculino , Neoplasias/diagnósticoRESUMEN
The plasma levels of tyrosine and the lipid peroxidation intermediate malonic dialdehyde (MDA) were measured in children with pigmental nevus and melanoma. They were found to have antioxidative protective failure. The presence of pigmental nevus predetermines the high incidence of tyrosine metabolic abnormalities. In children with pigmental nevus and melanoma, there was an impairment in the correlation of the parameters of tyrosine metabolism, the rate of free radical lipid peroxidation processes, and the status of the antioxidative system. The findings suggest that children with pigmental nevus may be referred to as a high cancer risk group and monitoring of these parameters should be recommended at follow-up of pigmental nevi.
Asunto(s)
Antioxidantes/metabolismo , Depuradores de Radicales Libres/metabolismo , Peroxidación de Lípido/fisiología , Melanoma/metabolismo , Nevo Pigmentado/metabolismo , Neoplasias Cutáneas/metabolismo , Tirosina/metabolismo , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/orina , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Malondialdehído/metabolismoRESUMEN
Lipid peroxidation (LP) occurring in pediatric cancer patients receiving polychemotherapy has been investigated. Plasma level of malonic dialdehyde in children with retinoblastoma (Rtb) was found to drop while it remained unchanged in patients with acute lymphoblastic leukemia (ALL). The treatment caused different changes in the red cell catalase levels in said groups: the enzyme concentration increased in the Rtb patients in the course of therapy and decreased in the ALL group. A slight decline in alpha-tocopherol and retinol levels the Rtb group was matched by a relevant rise in blood-plasma in the ALL group. To adjust LP regulation and improve resistance, antioxidants should be given to pediatric cancer patients suffering peroxidation-related stress.