The Effect Of Different Phototherapy Methods On Chromosome Of Newborns With Hyperbilirubinemia

The phototherapy (PT) is currently the most effective andcommon method of reducing serum bilirubin level in icteric newboms.The few mutagenic effect of PT has been reported. Following initialdomestic reports, increased frequency of sister chromatid exchange(SCE) was observed in the peripheral blood lymphocytes of neonatesgiven PT with intermittence double blue ligh treatment after 72 hours.Such that the frequency of SCE is considered to be a very sensitivecytogenetic index of mutagens and carcinogens. The results of foreignstudies were conflict. Up to the present, there was no study about themutagenic effects of single light.The purpose of our study was to determine whether intermittenceirradiation of single blue or white light has an adverse effect on theDNA of neonate with hyperbilirubinemia by examining the SCEfrequency of peripheral blood lymphocytes.The frequency of SCE in lymphocytes from l5 normal controls(group D) and 35 icteric treated infans was analyzed by SisterChromatid Differetance staining technique (SCD). We divided thepatients accepting PT into three groups according to three methods of4AbstractPT (grouP A: single blue ligh, l0 cases; grouP B: single white ligh,1 0 cases; group C: double blue light, l5 cases).The results showed that: (l) There is no obvious difference in thelevel of SCE before PT among grouP A. B and C, but the level of SCEin grouP D was Iower than that of other three groups; (2) In grouP A:less than three days, there was no difference between the level of SCEbefore theraPy and the level of SCE after theraPy After four days, thelevel of SCE increased; (3) Obvious changes were observed in grouPB. The frequency of SCE increased after one day and increasedsignificantly in a dose-dependan manner; (4) ComPared with the SCElevel before theraPy, the frequency of SCE increased after three days,but no obvious difference was observed after one day of theraPy ingrouP C. (5) After one day of treaAnent, there was no significantdifference in the frequency of SCE between grouP A and C. The SCEfrequency of grouP B was higher than that of others; (6) After tWodays of treaAnent, the frequency of SCE in grouP B was higher thangrouP A; (7) After three days of treaAnent, there was significantdifference in the frequency of SCE between grouP A and B. grouP Band C. grouP A and C. (8) After four days of treatment, the frequencyof SCE in grouP B was higher than that in grouP A.In summary PT has mutagenic effect on newboms withAbstracthyperbilirubinemia. The effect of single white ligh on peripheralblood lymPhocytes ofneonates was the most significant. The effect of. single bIue ligh was less obvious than double blue ligh.