Phototherapy for neonatal XXXX .

@entity1 @entity648 @entity35 @entity71514 @entity3638
New light has recently been shed on the way phototherapy reduces @entity648 concentration in icteric @entity1 . The introduction of a high-performance liquid chromatography technique led to the discovery of new photoisomers of @entity648 , the configurational and structural isomers with high and low quantum yields, respectively, and to a renewed interest in the photochemical properties of @entity648 in vitro and in vivo. Circular dichroism and absorption spectroscopies have then shown that @entity648 behaves like a bichromophoric system, with the 2 halves of the molecule strongly interacting in the excited state. This coupling mechanism makes the quantum yields of @entity648 photochemistry wavelength-dependent, with marked effects in the long wavelength edge of the @entity648 absorption spectrum. The photochemistry of @entity648 is substantially similar in icteric @entity35 and babies, and is consistent with what is observed in vitro. However, the metabolism of @entity648 photoproducts in @entity35 sometimes differs quite significantly from that in babies. In particular, only the low quantum yield structural isomer, @entity71514 , is efficiently excreted by babies. Although the relative role of the @entity648 photoprocesses in the therapy of @entity3638 is not yet known with certainty, the structural photoisomerization is generally assumed to represent the main route of @entity648 elimination. As a consequence, the determination of the spectral band that optimizes the process of formation of @entity71514 in neonate may represent an important step in the improvement of the clinical protocol of phototherapy. Therefore, in addition to reviewing the most recent data on @entity648 photochemistry and the metabolism of @entity648 products, this article presents a computation of the optimal light for @entity71514 formation. The combined effects of long-wavelength photochemistry of @entity648 and skin attenuation show that the optimal spectral range should be between 480 and 510 nm.
