Ultrasonography (US) is of value in the evaluation and characterization of breast masses in children. Most masses represent either normal breast tissue, cysts, or fibroadenomas. Premature thelarche may be unilateral, and normal breast tissue is found at US. Cysts are commonly retroareolar; when they become infected, they appear sonographically as a complex mass. Fibroadenoma is the most frequent breast tumor in adolescent girls, and it is usually solitary, homogeneous, and hypoechoic. Malignant breast lesions are very rare in children; most are due to metastatic disease secondary to rhabdomyosarcoma, leukemia, lymphoma, and neuroblastoma, and their US appearance is nonspecific. Gynecomastia in boys can be mimicked by general obesity and pectoral hypertrophy; US is helpful in the diagnosis, especially when gynecomastia is asymmetric. Most breast lesions in children and adolescents are benign, and surgery should be avoided to prevent later deformity. US is the ideal imaging modality to evaluate breast lesions and may be used to guide a fine-needle aspiration biopsy. Color Doppler US evaluation is helpful; cysts are avascular, fibroadenomas may be avascular or hypovascular, and abscesses show peripheral increased flow. Bloody nipple discharge is more common in prepubertal patients, may occur in infants, and may be secondary to mammary ductal ectasia. Discharge commonly resolves spontaneously, and findings at US are frequently normal.
Iron (Fe), copper (Cu), and zinc (Zn) fulfill various essential biological functions and are vital for all living organisms. They play important roles in oxygen transport, cell growth and differentiation, neurotransmitter synthesis, myelination, and synaptic transmission. Because of their role in many critical functions, they are commonly used in food fortification and supplementation strategies globally. To determine the involvement of divalent metal transporter 1 (DMT1) and human copper transporter 1 (hCTR1) on Fe, Cu, and Zn uptake, Caco-2 cells were transfected with four different shRNA plasmids to selectively inhibit DMT1 or hCTR1 transporter expression. Fe and Cu uptake and total Zn content measurements were performed in shRNA-DMT1 and shRNA-hCTR1 cells. Both shRNA-DMT1 and shRNA-hCTR1 cells had lower apical Fe uptake (a decrease of 51% and 41%, respectively), Cu uptake (a decrease of 25.8% and 38.5%, respectively), and Zn content (a decrease of 23.1% and 22.7%, respectively) compared to control cells. These results confirm that DMT1 is involved in active transport of Fe, Cu, and Zn although Zn showed a different relative capacity. These results also show that hCTR1 is able to transport Fe and Zn.
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