Standardization of phototherapy for neonatal hyperbilirubinemia using multiple-wavelength irradiance integration.

BACKGROUND: Phototherapy with radiation of 460-490 nm wavelengths provides the most potent therapeutic effect for neonatal jaundice. However, the efficacy of phototherapy has been estimated using single-wavelength detectors with sensitivity at approximately 460 nm. Cyclobilirubin formation capacity (CFC), which comprises the sum of the irradiance values from three wavelengths multiplied by their specific coefficients, has been proposed as an alternative marker to evaluate the efficacy of phototherapy. This study aimed to test whether two types of phototherapy devices with distinct spectral characteristics provide similar therapeutic effects on adjustment of device-to-patient distances to deliver similar CFCs. METHODS: Using a three-wavelength spectroradiometer, CFCs and footprints of the light-emitting diode and fluorescent tube devices were assessed. Having determined the device-specific distances that ensured similar CFCs, 32 newborn infants, requiring phototherapy for hyperbilirubinemia, were randomized into the light-emitting diode and fluorescent tube groups. The total serum bilirubin levels before and after phototherapy were assessed. RESULTS: The light-emitting diode and fluorescent tube devices had comparable CFCs at distances of 60 and 50 cm, respectively. Phototherapy reduced the total serum bilirubin levels from 18.1 to 14.6 mg/dL and from 19.1 to 15.1 mg/dL in the light-emitting diode and fluorescent tube groups, respectively. The two groups did not differ significantly with respect to the patients' clinical backgrounds, serum bilirubin levels, or changes before and after phototherapy. CONCLUSION: At similar CFCs, the two phototherapy devices reduced the total serum bilirubin levels by comparable amounts. Hence, determining CFCs may help predict phototherapy efficacy. This may ensure better safety and greater efficacy of the treatment for newborn infants.

Cupping therapy: An analysis of the effects of suction on skin and the possible influence on human health.

BACKGROUND: Cupping therapy is a traditional therapy that has been employed worldwide for thousands of years. Despite a lack of quality clinical studies evaluating the efficacy of cupping therapy, its long history and widespread use throughout the world suggests the commonly claimed health benefits should not be completely discounted as without merit. PURPOSE: The goal of this paper is to present the research detailing what is known concerning the effects of suction on skin and underlying tissue, and the reaction of the body to that stimulus. Understanding the literature on the physiological effects of this mechanical force may help elaborate an explanation for the advertised local and systemic effects of cupping therapy. FINDINGS: Negative pressure causes stretching of the skin and underlying tissue and dilation of the capillaries. This stimulates an increase in tissue blood flow, eventually leading to capillary rupture and ecchymosis. Macrophages phagocytize the erythrocytes in the extravascular space which stimulates the production of Heme Oxygenase-1 (HO-1) to metabolize the heme. Heme catalysis results in the production of carbon monoxide (CO), biliverdin(BV)/bilirubin(BR) and iron. HO-1, BV, BR, and CO has been shown to have antioxidant, anti-inflammatory, antiproliferative, and neuromodulatory effects in animal and human systems. These substances also stimulate a shift of macrophages to the anti-inflammatory M2 phenotype. There is evidence that the effects are both local and systemic. CONCLUSION: Besides the mechanical effect of cupping increasing the local blood flow and stretching underlying tissue, activation of the HO-1 system could account for many of cupping therapy's claimed local and systemic health benefits.

William A Silverman lecture.

This is the text of the William A Silverman lecture given by Dr David K Stevenson at the Pediatric Academic Societies Annual Meeting in Washington, DC, May 4-7, 2013.

Effect of light exposure on metalloporphyrin-treated newborn mice.

BACKGROUND: Neonatal hyperbilirubinemia arises from increased bilirubin production and decreased bilirubin elimination. Although phototherapy safely and effectively reduces bilirubin levels, recent evidence shows that it has adverse effects. Therefore, alternative treatments are warranted. Metalloporphyrins, competitive inhibitors of heme oxygenase (HO), the rate-limiting enzyme in bilirubin production, effectively reduce bilirubin formation; however, many are photoreactive. Here, we investigated possible photosensitizing effects of chromium mesoporphyrin (CrMP) and zinc deuteroporphyrin bis-glycol (ZnBG). METHODS AND RESULTS: Administration of CrMP or ZnBG to 3-d-old mouse pups (3.75-30.0 µmol/kg intraperitoneally) and exposure to cool white (F20T12CW) and blue (TL20W/52) fluorescent lights (+L) for 3 h, resulted in a dose-dependent mortality (50% lethal dose (LD50) = 21.5 and 19.5 µmol/kg, respectively). In contrast to ZnBG, there was no significant difference in survival between the CrMP+L and CrMP groups. Following 30 µmol/kg ZnBG+L, we found significant weight loss, decreased liver antioxidant capacities, and increased aspartate aminotransaminase levels. At 6-d post-light exposure, ZnBG+L-treated pups showed gross and histologic skin changes at doses >7.5 µmol/kg. No lethality was observed following treatment with 30 µmol ZnBG/kg plus exposure to blue light-emitting diodes. Phototoxicity of ZnBG was dependent on light source, emission spectrum, and irradiance. CONCLUSION: Low doses of ZnBG (<3.75 µmol/kg) retained maximal HO inhibitory potency without photosensitizing effects, and therefore are potentially useful in treating neonatal hyperbilirubinemia.

Heme oxygenase-derived carbon monoxide modulates gonadotropin-releasing hormone release in immortalized hypothalamic neurons.

Heme oxygenase (HO), the main enzyme deputed to heme metabolism, has been identified as two main isoforms called HO-1 and HO-2 both present in the central nervous system. Heme oxygenase has been shown to regulate the hypothalamic release of neuropeptides such as corticotrophin-releasing hormone and arginin-vasopressin. The aim of this study was to investigate and further characterize the presence of HO in gonadotropin-releasing hormone (GnRH) secreting hypothalamic neurons, GT1-7 and the role of HO by-products on GnRH secretion. The pulsatile release of GnRH from scattered hypothalamic neurons is the key regulator of mammalian fertility in the central nervous system. GT1-7 cells are immortalized hypothalamic neurons, characterized by spontaneous electrical activity and pulsatile GnRH release, resembling the central control pathway of the hypothalamic pituitary gonadal axis (HPG) in mammals. Hemin, the substrate of HO, significantly stimulated HO activity in static cultures, causing a rapid increase in GnRH release. Neither biliverdin nor bilirubin were able to mimic this rapid stimulatory effect, which was instead caused by carbon monoxide. Evidence of a possible involvement of prostaglandin E(2) in the HO by-product modulated GnRH secretion was reported. The hemin-evoked effect on GT1-7 neurons suggests a direct activity of HO by-products on the hypothalamic neuropeptide secretion, and claims for a possible role of CO in both the modulation of gonadotropin secretion and crosstalk among HPG and stress axis within the mammalian hypothalamus.

Hyperbilirubinemia.

Hyperbilirubinemia is the most common condition requiring evaluation and treatment in newborns. The clinical manifestation of hyperbilirubinemia-jaundice-occurs in 60% of normal newborns and nearly all preterm infants. Compared with conditions that require advanced pharmacologic and technologic treatment strategies, hyperbilirubinemia seems to be overshadowed and may lose the attention it deserves as a condition that has potentially devastating effects. Nurses must be vigilant when caring for babies with "just jaundice" by monitoring bilirubin levels, identifying infants at risk for developing severe hyperbilirubinemia, and implementing prescribed treatment effectively when indicated.

Heme oxygenase-1 mediates the inhibitory actions of brazilin in RAW264.7 macrophages stimulated with lipopolysaccharide.

Brazilin, the main constituent of Caesalpinia sappan L., is a natural red pigment that has been reported to possess anti-inflammatory properties. This study aimed to identify a novel anti-inflammatory mechanism of brazilin. We found that brazilin did not cause cytotoxicity below 300 microM, and activated heme oxygenase-1 (HO-1) protein synthesis in a concentration-dependent manner at 10-300 microM in RAW264.7 macrophages without affecting mRNA transcription of HO-1. Additionally, brazilin increased bilirubin production and HO-1 activity in RAW264.7 macrophages. In lipopolysaccharide (LPS)-stimulated macrophages, brazilin suppressed the release of nitric oxide (NO), prostaglandin E(2) (PGE(2)), interleukin (IL)-1beta and tumor necrosis factor-alpha (TNF-alpha), and reduced the expression of inducible nitric oxide synthase (iNOS). A specific inhibitor of HO-1, Zn(II) protoporphyrin IX, blocked the suppression of NO production, cytokines release and iNOS expression by brazilin. These results suggest that brazilin possesses anti-inflammatory actions in macrophages and works through a novel mechanism involving the action of HO-1.

Inhibition of heme oxygenase activity in newborn mice by azalanstat.

Inhibition of heme oxygenase (HO), the rate-limiting enzyme in heme catabolism, may be an ideal strategy for preventing neonatal jaundice. Although natural and synthetic heme analogs, called metalloporphyrins (Mps), have been extensively investigated for this purpose, some Mps are phototoxic, affect the activity of other enzymes, or induce HO-1 transcription-properties that may limit their clinical use. Another class of compounds, imidazole-dioxolanes, has been shown to selectively inhibit the inducible isozyme HO-1. Therefore, we investigated the efficacy of azalanstat (AZA), an imidazole-dioxolane, towards inhibiting HO activity in 7-day-old mice. We found that a single dose of AZA at 500 micromol.kg(-1) body mass (BM) administered i.p. significantly inhibited HO activity and reduced in vivo bilirubin production. In the spleen, HO inhibition (>50%) was observed within 0.25-3 h after administration. After 24 h, however, spleen HO activity, HO-1 protein, and HO-1 mRNA levels significantly increased 1.2-, 2.4-, and 4.0-fold, respectively. We conclude that AZA effectively inhibits in vivo HO activity only at a high dose and that it also induces spleen HO-1 gene transcription. Therefore, other imidazole-dioxolanes should be evaluated to determine whether they are more potent than AZA for use in treating neonatal jaundice.

In vitro production of bilirubin photoisomers by light irradiation using neoBLUE.

BACKGROUND: The light-emitting diode is used as one of the new light sources for phototherapy. NeoBLUE (Atom Medical, Tokyo, Japan) incorporates blue light-emitting diodes for the treatment of neonatal hyperbilirubinemia. The authors compared the in vitro efficacy of neoBLUE with conventional phototherapy devices. METHODS: The three light devices used included neoBLUE and two conventional phototherapy devices with six blue-white (BW) or six green (GR) fluorescent tubes. A bilirubin/human serum albumin solution (15 mg/dL) in 200 x 300 mm elliptical bag was irradiated with each three light device. The average light intensity of neoBLUE, BW and GR was 22.5, 10.2 and 2.6 microW/cm(2) per nm, respectively, for the irradiated area. Bilirubin photoisomers and native bilirubin were measured by high-performance liquid chromatography. RESULTS: In neoBLUE, BW and GR, the respective production rate of cyclobilirubin was 6.0, 3.7 and 3.9 x 10(-2) mg/dL/min, and the respective (4Z, 15E)-bilirubin/(4Z, 15Z)-bilirubin ratio after irradiation was 0.44, 0.33 and 0.12; the (4Z, 15Z)-bilirubin reduction rate at 20 min after irradiation was 60, 68 and 82%, respectively. The reduction rate of (4Z, 15Z)-bilirubin correlated with the (4Z, 15E)-bilirubin/(4Z, 15Z)-bilirubin ratio. CONCLUSION: Phototherapy using the neoBLUE under high level may be clinically more effective than therapy using the conventional light source from the results of the production rate of cyclobilirubin.

Recent advances in the pharmacotherapy for hyperbilirubinaemia in the neonate.

Jaundice is a common cause for diagnostic works-up and therapeutic intervention in neonates. This is motivated by the risk for severe neurological sequelae (kernicterus). The mainstays of treatment for the past decades have been exchange transfusion and phototherapy. Exchange transfusion is now becoming rare due to immune prophylaxis in Rhesus-negative women, and treatment of sensitised infants with intravenous immunoglobulin. Several different pharmacological approaches have been studied as far as the treatment of neonatal jaundice. Of these, the focus of attention in recent years has been on the haem oxygenase inhibitors (metal meso- and protoporphyrins). These are effective inhibitors of bilirubin production and have been shown to significantly reduce peak serum bilirubin levels in several clinical trials, both when used prophylactically and therapeutically. However, questions remain regarding long-term safety, as well as the advisability of whole-scale inhibition of bilirubin production. Nevertheless, in selected infants with a high risk of severe jaundice, the use of haem oxygenase inhibitors may be acceptable. Pharmacotherapy in jaundiced infants is fraught with risks, as many drugs may increase the entry of bilirubin into the brain and presumably, the risk for neurotoxicity. Both the displacement of bilirubin from its albumin binding and interference with the function of phosphoglycoprotein in the blood-brain barrier are documented mechanisms in this respect.

New approach for the establishment of an hepatocyte cell line derived from rat early embryonic stem cells.

A cell line with the characteristics of hepatocytes was established from rat early embryonic stem cells (REES). This cell line was established using a new novel method of Ishiwata et al. from two cell embryos taken from the spontaneous dwarf rat (SDR). The hepatocyte cell line (REES-hep) was instituted from dark red colored tissue in embryos during embryogenesis using REES cell line cultured in the presence of embryotrophic factors. These cell lines were cultured with DMEM/F12 medium supplemented 10% FBS and 1 ng/ml of LIF. They were found to maintain their diploid state, were characterized with 42 normal chromosomes and proliferated to confluence; contact inhibition was also present. These cells produced albumin when cultured using a collagen sponge gel system and reconstructed in a funicular form resembling the cell cords of liver. The cells also produced albumin and bilirubin when transplanted into the spleen of SDR Reconstruction of a REES-hep cell line from early embryonic stem cells should help in treating hepatic insufficient patients. It will be valuable for further research, as an introduction to cell transplantation and application for use in a bio-hybrid typed liver apparatus.

Cyclobilirubin formation by in vitro photoirradiation with neonatal phototherapy light.

BACKGROUND: The main mechanism of phototherapy for neonatal hyperbilirubinemia is the production and excretion of (EZ)- and (EE)-cyclobilirubin (4E,15Z- and 4E,15E-cyclobilirubin). Thus, the clinical efficacy of the light source for phototherapy must be evaluated by cyclobilirubin formation from (ZZ)-bilirubin in in vitro photoirradiation. METHODS: In the present study, we investigated the in vitro production pattern of bilirubin photoisomers by phototherapy light from the bilirubin-human serum albumin complex. RESULTS: No clear difference was found in the curves relative to (ZZ)-bilirubin and its photoisomers under aerobic and anaerobic conditions. The ratio of (EZ)-cyclobilirubin to (ZZ)-bilirubin increased proportionately to the dose of irradiating light and no photoequilibrium state was observed analogous to that found in configurational photoisomerization. The concentration of (EZ)- and (EE)-cyclobilirubin increased proportionately with the grade of the percentage decrease in A(460 nm) from 0 to 23%. With a percentage decrease in A(460 nm) of 23% or more, the cyclobilirubin concentrations reached a steady state. The reason for this appears to be that the concentration of (ZZ)-bilirubin, a substrate for photoisomers, dropped below 1 mg/100 mL. Biliverdin was produced only in trace amounts. However, the absorption at 520--700 nm increased after a percentage decrease in A(460 nm) of more than 23%. CONCLUSIONS: The results of the present study show that little bilirubin photooxidation occurred with in vitro aerobic photoirradiation. Before the concentration of cyclobilirubin reaches a steady state, it is theoretically valid to use the percentage decrease in A(460 nm) for the evaluation of the clinical efficacy of the light source.

Phototherapy increases hemoglobin degradation and bilirubin production in preterm infants.

OBJECTIVE: To compare hemoglobin degradation and bilirubin production before and during phototherapy in preterm infants. BACKGROUND: Hemoglobin is catabolized into globin and heme, which is degraded by microsomal heme oxygenase into equimolar carbon monoxide and biliverdin. Biliverdin is then reduced into bilirubin. CO is excreted exclusively by the lungs; therefore, end-tidal carbon monoxide, corrected for inhaled CO (ETCOc), reflects hemoglobin degradation and total bilirubin production. METHOD: A prospective study design was used, including a study group of 24 preterm infants requiring phototherapy. Infants with hemolytic diseases, sepsis, recent blood transfusion, and infants on mechanical ventilation were excluded. ETCOc was measured in preterm infants before and during phototherapy. Hemoglobin degradation and bilirubin production were calculated by measuring ETCOc. RESULTS: The (mean +/- SD) birth weight of 24 preterm neonates was 1975 +/- 613 gm, gestational age was 32.7 +/- 2.3 weeks, hematocrit was 47.5 +/- 6.2 volume%, and peak bilirubin was 13.1 +/- 3.2 mg/dl. First ETCOc measurements were done at 59.6 +/- 22.2 hours of age immediately before starting phototherapy. The second ETCOc measurements were taken at 13.7 +/- 7.9 hours after starting phototherapy. The second measurement of 2.6 +/- 0.6 ppm (mean +/- SD) was significantly higher than the first ETCOc of 2.1 +/- 0.6 ppm (p < 0.05). CONCLUSION: Phototherapy increases hemoglobin degradation and bilirubin production in preterm infants.

Activation of heme oxygenase and consequent carbon monoxide formation inhibits the release of arginine vasopressin from rat hypothalamic explants. Molecular linkage between heme catabolism and neuroendocrine function.

Heme oxygenase (HO)-catalyzed degradation of cellular heme moieties generates biliverdin and equimolar amounts of carbon monoxide (CO), which has been implicated as a possible modulator of neural function. Technical difficulties preclude direct measurements of CO within intact nervous tissues; hence, alternative procedures are needed to monitor the formation and possible biologic functions of this gas. In the present study rat hypothalamic explants were found to generate 114 +/- 5 or 127 +/- 11 pmol biliverdin/hypothalamus/1 h (n = 3) upon incubation with 1 or 10 microM hemin, respectively. Ten micromolar zinc-protoporphyrin IX (Zn-PP-IX), a known inhibitor of HO, significantly decreased the degradation of 10 microM hemin from 127 +/- 11 to 26 +/- 11 pmol biliverdin/hypothalamus/1 h (n = 3; P < 0.01). Biliverdin was the principal product of HO-dependent heme degradation, as its possible conversion into bilirubin was precluded by hemin-dependent inhibition of biliverdin reductase. Basal or hemin-supplemented hypothalamic incubations were also shown to generate sizable amounts of propentdyopents (PDPs), reflecting HO-independent degradation pathways which do not liberate CO and cannot be inhibited by Zn-PP-IX. Plotting the ratio of biliverdin to PDPs thus provided an index of the efficiency with which hemin was degraded through biochemical pathways involving CO. Under the experimental conditions of our study, the biliverdin/PDPs ratio varied from 0 to 32 or 15%, depending on the absence or presence of 1 or 10 microM hemin respectively: this suggested that the formation of CO was most efficient at 1 microM hemin. Under these defined conditions, 1 microM hemin was also found to inhibit the release of arginine vasopressin (AVP) evoked by depolarizing solutions of KCl. A series of experiments showed that the effect of hemin was counteracted by Zn-PP-IX, and also by tin-mesoporphyrin IX, which is even more selective in inhibiting HO; it was also attenuated in the presence of the gaseous scavenger ferrous hemoglobin. Furthermore, the inhibition of AVP release could be reproduced by omitting hemin and by incubating hypothalami under CO, whereas treatment with biliverdin had no effect. This suggested that the release of AVP was suppressed by HO degradation of hemin, yielding CO as a modulator of hypothalamic function. These observations may be relevant to diseases characterized by inappropriate secretion of AVP and enzymatic disturbances affecting the synthesis of heme and the formation of CO through the HO pathway (e.g., acute intermittent porphyria or lead intoxication).

Induction of hepatic bilirubin and drug metabolizing enzymes by individual herbs present in the traditional Chinese medicine, yin zhi huang.

Yin Zhi Huang (YZH) is a decoction of four plants which is widely used in Asia to treat neonatal jaundice. This study compares the ability of phenobarbital and the individual herbs comprising YZH, Artemisia, Gardenia, Rheum, and Scutellaria baicalensis, to induce hepatic drug and bilirubin metabolizing enzymes in rats. Herbal decoctions (30 ml/kg/day) or phenobarbital (60 mg/kg/day) were administered for 5 days. Only phenobarbital increased cytochrome P-450 levels whereas Gardenia slightly decreased levels. Artemisia, Rheum and phenobarbital increased bilirubin glucuronyl transferase activity. Glucuronidation of alpha-naphthol was increased by Gardenia and phenobarbital, whereas Artemisia and Rheum were ineffective inducers. Phenobarbital was the most effective inducer of glutathione-S-transferase (GSHT) activity. Phenobarbital and Gardenia both induced delta 5-3-ketosteroid isomerase activity, a marker for the Ya subunit of GSHT responsible for intracellular bilirubin transport in liver. The selective patterns of enzyme induction suggest potential value for using specific plant decoctions to modify drug and bilirubin metabolic pathways.

Fototerapia: nem tudo que ilumina trata / Phototherapy: nor everything that lights up negotiates

Desde sua introduçäo em 1958 a fototerapia tem sido largamente utilizada em neonatologia. Estima-se que cerca de 10 por cento dos recém-nascidos säo submetidos anualmente a fototerapia. Entretanto, apesar do uso frequente e rotineiro, esta terapia ainda e utilizada de maneira empírica e näo controlada na maioria dos serviços. Entre os profissionais de saúde que prestam assistência a recém-nascidos, existe uma crença bastante difundida de que as lâmpadas de fototerapia devem ser substituídas após determinado tempo de uso. Näo existe, entretanto, um consenso quanto ao momento apropriado da substituiçäo. Alguns serviços preconizam a troca após 240 horas de uso, outros com 400, 600 e até 2000 horas de uso. Este estudo, conduz a 2 etapas. Na primeira etapa o objetivo foi determinar o momento ideal para a substituiçäo das lâmpadas fluorescentes baseado no tempo de uso. Numa segunda etapa desta investigaçäo, analisam a situaçäo dos aparelhos de fototerapia utilizados em hospitais públicos do Rio de Janeiro. Determina através da mediçäo periódica da irradiância emitida utilizando-se fotodosimetros especiais. A irradiância emitida por aparelhos de fototerapia de fabricaçäo nacional säo significativamente menores do que as doses terapêuticas recomendadas na literatura.

Carboxyhemoglobin concentration as an index of bilirubin production in neonates with birth weights less than 1,500 grams: a randomized double-blind comparison of supplemental oral vitamin E and placebo.

A randomized double-blind study of the efficacy of oral vitamin E supplementation as a prophylactic treatment for hyperbilirubinemia was undertaken in preterm infants weighing less than 1,500 g. Hemoglobin (Hb) levels, blood carboxyhemoglobin saturation (HbCOc), end-tidal carbon monoxide concentration (ETCO), and serum total bilirubin levels were determined in each subject on the first and third days of the study. We found no differences between the vitamin E-treated and placebo-treated groups with respect to Hb, HbCOc, ETCO, or serum bilirubin levels on day 1 or 3. In addition, we reanalyzed our data to compare those infants who had low vitamin E levels at birth with those who had vitamin E levels greater than 0.4 mg/dl on day 1. We still observed no differences in Hb, HbCOc, ETCO, or serum bilirubin levels on day 1 or 3. The results of our study suggest that supplemental oral vitamin E therapy has no major effect on bilirubin production during the first 3 days of life in premature infants weighing less than 1,500 g at birth.