Wavelengths of light producing photodecomposition of bilirubin in serum from a neonate with hyperbilirubinemia

Raethel, H. A.

doi:10.1016/s0022-3476(75)80084-9

Cited by 19 publications

(10 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Because of the experimental design, the physiological relevance of that study is questionable: photoisomerization reactions were neglected, photoreactions were allowed to go to high conversion and performed on unstirred solutions in cells of long photochemical pathlength, and samples had higher optical thicknesses at 457.9 and 488.0 nm than at longer wavelengths. The results disagreed with those of several other more detailed studies (Gutcher et al, 1983;Lightner et al, 1980;Raethel, 1975), probably because of a failure to recognize the effects of optical thickness differences. Nevertheless, clinical trials (which did not include a control group of unirradiated infants) have indicated that green lights do have a phototherapeutic effect (Sbrana et al, 1987), though they are not more effective than blue lights (Foschi et al, 1986;Ayyash et al, 1987a, b).…”

Section: Clinical Implications; Green Light Phototherapycontrasting

confidence: 90%

Quantum Yields for Laser Photocyclization of Bilirubin in the Presence of Human Serum Albumin. Dependence of Quantum Yield on Excitation Wavelength

McDonagh¹,

Agati²,

Fusi³

et al. 1989

Photochem & Photobiology

View full text Add to dashboard Cite

The quantum yield for laser photocyclization of bilirubin to lumirubin in the presence of human serum albumin (phi LR) was measured at five monochromatic excitation wavelengths in the range 450-530 nm. Solutions used were optically thin throughout the wavelength range and precautions were taken to exclude contributions from photocyclization of bilirubin XIII alpha impurities. The values obtained (7.2-18 x 10(-4] were lower than those previously reported and showed the following wavelength dependence: 457.9 less than 488.0 less than 501.7 less than 514.5 approximately equal to 528.7. However, the rate of lumirubin formation, normalized to constant fluence, decreased with wavelength over the same wavelength range and no evidence was found that photoisomerization of bilirubin to lumirubin is faster with green (514.5 or 528.7 nm) than with blue (457.9 or 488.0 nm) light. The stereoselectivity of the configurational isomerization of bilirubin to 4Z,15E and 4E,15Z isomers also was studied. This reaction became less regioselective for the 4Z,15E isomer with increasing wavelength. The observed wavelength dependence of phi LR and of the [4E,15Z]: [4Z,15E] ratio at photoequilibrium are consistent with an exciton coupling model in which intramolecular energy transfer can occur between the two pyrromethenone chromophores of the bilirubin molecule in the excited state. Relative rates of lumirubin formation in vivo at different excitation wavelengths and constant fluence were estimated for different optical thicknesses and for different skin thicknesses. These estimates suggest that the recently reported clinical equivalence of blue and green phototherapy lights probably reflects the marked variation of skin transmittance with wavelength more than wavelength-dependent photochemistry. The calculations also indicated that the optimal wavelength for phototherapy is probably on the long wavelength side of the bilirubin absorption maximum.

show abstract

Section: Clinical Implications; Green Light Phototherapycontrasting

confidence: 90%

Quantum Yields for Laser Photocyclization of Bilirubin in the Presence of Human Serum Albumin. Dependence of Quantum Yield on Excitation Wavelength

McDonagh¹,

Agati²,

Fusi³

et al. 1989

Photochem & Photobiology

View full text Add to dashboard Cite

show abstract

“…The clinical application of this phenomenon has been widely used as phototherapy in the treatment of neonatal hyperbilirubinemia. Investigations designed to delineate the effective wavelengths have employed broad spectrum light sources and have indicated that irradiance with light of wavelengths of 425-475 nm is maximally effective both in vitro (2,7,8,10,13,25,31) and in vivo (1,11,17,24,29,33,36). But one study performed in vitro with a relatively narrow spectral source suggested wavelengths at 490 nm might also be efficacious (10).…”

mentioning

confidence: 99%

The in Vitro and in Vivo Photoreactivity of Bilirubin: I. Laser-Defined Wavelength Dependence

1983

View full text Add to dashboard Cite

SummaryMonochromatic light was provided by a continuous wave Argon ion laser. We chose to study the in vitro effects of light at 457.9, 465.8, 476.5, 488.0, 501.7, and 514.5 nm as representative of a reasonably evenly spaced samplig across the blue-green spectrum. The in vivo experiments were conducted at 457.9, 476.5, 488.0, and 514.5 nm.In vitro light at 488.0 nm appeared to be more effective than the others studied.After 24 h of irradiance, the in vivo decline in serum bilirubin concentration produced by light at 488.0 nm was one-and-one-half, two, and four times as effective as light at 457.9, 476.5 and 514.5 nm, respectively. By 48 h of exposure, the declines produced by light at 457.9 nm and 488.0 nm are significantly superior to that at 476.5 nm and 514.5 nm, but they do not differ from one another.The photon-induced chemical alteration of bilirubin has been demonstrated by various light sources both in vitro and in vivo. The clinical application of this phenomenon has been widely used as phototherapy in the treatment of neonatal hyperbilirubinemia. Investigations designed to delineate the effective wavelengths have employed broad spectrum light sources and have indicated that irradiance with light of wavelengths of 425-475 nm is maximally effective both in vitro (2,7,8,10, 13,25,31) and in vivo (1,11,17,24,29,33,36). But one study performed in vitro with a relatively narrow spectral source suggested wavelengths at 490 nm might also be efficacious (10). More recently, Lilien et al. (27) have performed experiments that also suggest that wavelengths of light beyond the 425475 nm range are efficacious in vitro.Radiant energies within the 400-500 nm range exhibit potential for inducing damage to tissues. Light from standard fluorescent lamps causes breaks in DNA strands in vitro (3, 35) and increases sister chromatid exchanges and other chromosomal alterations in cultured cells (4,18,21,23,32,35,37). An increased frequency of sister chromatid exchange has been reported in some infants after phototherapy (12). Although we know of no reports regarding any increase in sister chromatid exchange in vivo in response to monochromatic light, the occurrence seems likely; thus, the widespread use of phototherapy has generated concern regarding the potential for long-term mutagenic and carcinogenic effects. Inasmuch as most published data suggest that the offending wavelengths are principally in the ultraviolet range, some recent work has implicated light of wavelengths exceeding 300 nm (9) and, indeed, some alterations appear to occur maximally in response to wavelengths of light between 420-500 nrn (35). Although the magnitude of these latter risks has not been quantitated as they may relate to the clinical setting, it seems desirable to more precisely define the most efficacious wavelengths for the photoalteration of bilirubin that results in its enhanced excretion. This is particularly needed in the design of future phototherapy instruments to be used in the management of neonatal hyperbilirubinemia. Preliminary po...

show abstract

“…The use of phototherapy equipment with efficient average spectral irradiance 16,22,23 caused the levels to be very close to those of early-treated infants in the study carried out by Curtis-Cohen et al 20 If we had used the same criterion for the late-treatment group we would not probably have found any significant difference between the two groups tested. When both groups were divided into subgroups according to their weight (< 1,000 g, 1,000 to 1,500 g, and > 1,500 g), there was a clear difference as to the incidence of levels greater than 10 mg/dl, although the number of cases in each subgroup does not allow any statistical evaluation.…”

Section: In 1985mentioning

confidence: 91%

Avaliação de dois esquemas de manejo da hiperbilirrubinemia em recém-nascidos com peso menor que 2.000 g

Leite¹,

Facchini²

2004

J. Pediatr. (Rio J.)

View full text Add to dashboard Cite

Objective: To evaluate the use of two phototherapy guidelines for the treatment of hyperbilirubinemia in newborn babies weighing less than 2,000 g. Methods:Eighty-one newborn infants with birth weight less than 2,000 g were studied. They were divided in two groups: the early group, which started phototherapy 12 hours after birth, undergoing treatment for at least 96 hours; and the late group, which received phototherapy whenever the transcutaneous bilirubin reached 8 mg/dl and phototherapy suspended when bilirrubin levels fell to 5 mg/dl. The following factors were analyzed: maintenance of transcutaneous bilirubin levels below 10 mg/dl, mean value of daily transcutaneous bilirubin, the highest transcutaneous bilirubin value and the period it first occurred, and duration of treatment.Results: In the early group, 20% of all patients showed transcutaneous bilirubin level higher than 10 mg/dl compared to 60% of patients in the late group. The highest daily mean rate of transcutaneous bilirubin in the early group was 6.6 mg/dl, which happened on the 7th day. In the late group, it was 8.6 mg/dl on the 2nd day after birth. The median duration of phototherapy treatment used in the early group was 96 hours (minimum of 96 and maximum of 156 hours) and in the late group, 51 hours (minimum of zero and maximum of 120 hours). None of the babies needed changes in the treatment (double phototherapy or exchange transfusion). Conclusion:The use of early phototherapy treatment for babies weighing less than 2,000 g is safer when compared to the late group, considering satisfactory the maintenance of transcutaneous bilirubin levels below 10 mg/dl.

show abstract

Wavelengths of light producing photodecomposition of bilirubin in serum from a neonate with hyperbilirubinemia

Cited by 19 publications

References 16 publications

Quantum Yields for Laser Photocyclization of Bilirubin in the Presence of Human Serum Albumin. Dependence of Quantum Yield on Excitation Wavelength

Quantum Yields for Laser Photocyclization of Bilirubin in the Presence of Human Serum Albumin. Dependence of Quantum Yield on Excitation Wavelength

The in Vitro and in Vivo Photoreactivity of Bilirubin: I. Laser-Defined Wavelength Dependence

Avaliação de dois esquemas de manejo da hiperbilirrubinemia em recém-nascidos com peso menor que 2.000 g

Contact Info

Product

Resources

About