Purpose: To validate our initial pilot study and confirm sustained safety and tumor response of extended-shelf-life super(90)Y glass microspheres. We hypothesized that for the same planned tissue ...dose, the increase in number of glass microspheres (decayed to the second week of their allowable shelf-life) administered for the same absorbed dose would result in better tumor distribution of the microspheres without causing additional adverse events. Methods: Between June 2007 and January 2010, 134 patients underwent radioembolization with extended-shelf-life super(90)Y glass microspheres; data from 84 new patients were combined with data from our 50-patient pilot study cohort. Baseline and follow-up imaging and laboratory data were obtained 1 and 3 months after therapy and every 3 months thereafter. Clinical and biochemical toxicities were prospectively captured and categorized according to the Common Terminology Criteria. Response in the index lesion was assessed using WHO and EASL guidelines. Results: The mean delivered radiation dose was 123 Gy to the target liver tissue. The mean increase in number of microspheres with this approach compared to standard super(90)Y glass microsphere dosimetry was 103 %, corresponding to an increase from 3.84 to 7.78 million microspheres. Clinical toxicities included fatigue (89 patients, 66 %), abdominal pain (49 patients, 36.6 %), and nausea/vomiting (25 patients, 18.7 %). Grade 3/4 bilirubin toxicity was seen in three patients (2 %). Two (1 %) of the initial 50-patient cohort showed gastroduodenal ulcers; gastroduodenal ulcers were not seen in any of the subsequent 84 patients. According to WHO and EASL guidelines, response rates were 48 % and 57 %, respectively, and 21 % demonstrated a complete EASL response. Conclusion: This study showed sustained safety and efficacy of extended-shelf-life super(90)Y glass microspheres in a larger, 134-patient cohort. The increase in number of microspheres administered theoretically resulted in better tumor distribution of the microspheres without an increase in adverse events.
Recent research on bilirubin, a historically well-known waste product of heme catabolism, suggests an entirely new function as a metabolic hormone that drives gene transcription by nuclear receptors. ...Studies are now revealing that low plasma bilirubin levels, defined as "hypobilirubinemia," are a possible new pathology analogous to the other end of the spectrum of extreme hyperbilirubinemia seen in patients with jaundice and liver dysfunction. Hypobilirubinemia is most commonly seen in patients with metabolic dysfunction, which may lead to cardiovascular complications and possibly stroke. We address the clinical significance of low bilirubin levels. A better understanding of bilirubin's hormonal function may explain why hypobilirubinemia might be deleterious. We present mechanisms by which bilirubin may be protective at mildly elevated levels and research directions that could generate treatment possibilities for patients with hypobilirubinemia, such as targeting of pathways that regulate its production or turnover or the newly designed bilirubin nanoparticles. Our review here calls for a shift in the perspective of an old molecule that could benefit millions of patients with hypobilirubinemia.
Despite a century of research, bilirubin metabolism and the transport mechanisms responsible for homeostasis of bilirubin in serum remain controversial. Emerging evidence on the hepatic membrane ...transporters and inherited disorders of bilirubin metabolism have contributed to a greater understanding of the various steps involved in bilirubin homeostasis and its associated excretory pathways. We discuss these recent research findings on hepatic membrane transporters and evaluate their significance on the newborn bilirubin metabolism and excretion. New insights gained speculate that a proportion of conjugated bilirubin is excreted via the renal system, as an alternative to the intestinal excretion, even in normal physiological jaundice with no associated pathological concerns. Finally, this paper discusses the clinical relevance of targeting the altered renal excretory pathway, as bilirubin in urine may hold diagnostic importance in screening for neonatal jaundice.
Healthy infants are thought to acquire biliary atresia (BA) in the first weeks of life. Because those diagnosed earlier have better outcomes, we were interested in determining the earliest time BA ...could be detected. We started by examining the immediate postnatal period, hypothesizing that newborns would not yet have acquired disease and still have normal direct/conjugated bilirubin (DB/CB) levels.
Newborn DB/CB levels were obtained retrospectively from birth hospitals. Subjects with BA were born between 2007 and 2010 and cared for at Texas Children's Hospital. Those with BA splenic malformation syndrome or born prematurely were excluded. Control subjects were term newborns who later never developed neonatal liver disease.
Of the 61 subjects with BA, 56% had newborn DB/CB levels measured. All DB/CB levels exceeded laboratory norms and rose over time. At 24 to 48 hours of life, subjects with BA had mean DB levels significantly higher than those of controls (1.4 ± 0.43 vs. 0.19 ± 0.075 mg/dL, P < .0001), even while their mean total bilirubin (TB) levels remained below phototherapy limits. Finally, despite the elevated DB/CB levels, the majority of patients (79%) had normal DB:TB ratios ≤ 0.2.
Patients with BA have elevated DB/CB levels shortly after birth. To detect affected infants earlier and improve outcomes, the results suggest two possibilities: (1) screen all newborns for elevated DB/CB levels, rather than just those who appear jaundiced; and then (2) follow all newborns with elevated DB/CB levels, rather than just those with DB:TB ratios >0.2.
To evaluate the effect of intravenous (IV) ceftriaxone on free bilirubin concentrations in infants with unconjugated hyperbilirubinemia born at term.
A prospective study was performed with subjects ...serving as their own controls. Our inclusion criteria were infants born at term <7 days old with sepsis and receiving IV antibiotics for >3 days and resolving hyperbilirubinemia with total serum bilirubin levels between 6 and12 mg/dL by day 4 of life. Free bilirubin concentrations were measured by the peroxidase method using a UB analyzer and a Zone Fluidics device before (baseline) and 15 minutes after (follow-up) IV ceftriaxone administration on postnatal days 4 to 6. Paired measurements of free bilirubin were analyzed using a Student paired t-test or Wilcoxon signed-rank test.
In total, 27 infants were studied. The mean free bilirubin (μg/dL) at follow-up was not different from that at baseline when measured by the UB analyzer (P = .78). The mean free bilirubin was significantly lower at follow-up compared with baseline when measured by the Zone Fluidics device (P = .02). The ratio of a free bilirubin with and without ceftriaxone, an index of displacing effect, was 1.02 (95% CI 0.89-1.14) using the UB analyzer and 0.58 (95% CI 0.30-0.86) using the Zone Fluidics device.
Ceftriaxone is not associated with a bilirubin-displacing effect in infants with a mild unconjugated hyperbilirubinemia. Home therapy with once-daily intramuscular ceftriaxone may be an alternative option for management of sepsis in asymptomatic infants with a mild unconjugated hyperbilirubinemia born at term.
Abstract Although asthma, a chronic inflammatory airway disease, is relatively well-managed by inhaled corticosteroids, the side effects associated with the long-term use of these agents precipitate ...the need for alternative therapeutic options based on differing modes of action. Bilirubin, a potent endogenous antioxidant, and anti-inflammatory molecule have been shown to ameliorate asthmatic symptoms; however, its clinical translation has been limited owing to its water insolubility and associated potential toxicity. Here we report the first application of bilirubin-based nanoparticles (BRNPs) as a nanomedicine for the treatment of allergic lung inflammatory disease. BRNPs were prepared directly from self-assembly of PEGylated bilirubin in aqueous solution and had a hydrodynamic diameter of ∼100 nm. Because allergen-specific type 2 T-helper (Th2) cells play a key role in the pathogenesis and progression of allergic asthma, the effects of BRNPs on Th2 immune responses were investigated both in vivo and in vitro . BRNPs after intravenous injection (i.v.) showed much higher serum concentration and a longer circulation time of bilirubin than the intraperitoneal injection (i.p.) of BRNPs or unconjugated bilirubin (UCB). The anti-asthmatic effects of BRNPs were assessed in a mouse model of allergen-induced asthma. Compared with UCB, treatment with BRNPs suppressed the symptoms of experimental allergic asthma and dramatically ameliorated Th2-related allergic lung inflammation. Consistent with these results, BRNPs caused a reduction of Th2 cell populations and the expression of related cytokines by antibody-stimulated CD4+ T cells in vitro . Therefore, our results establish BRNPs as an important immunomodulatory agent that may be useful as a therapeutic for allergic lung inflammatory disease and other immune-mediated disorders.
Unconjugated bilirubin (UCB), the principal mammalian bile pigment, is the end product of heme catabolism. Both belong to the superfamily of tetrapyrrolic compounds that serve multiple biological ...functions in animals and plants. Its six internal hydrogen bonds give UCB a unique structure responsible for its physico-chemical properties and biological effects. Like many weakly-polar, poorly-soluble compounds, UCB is transported in blood tightly bound to albumin, with less than 0.01% of total bilirubin circulating in an unbound form (free bilirubin, Bf). This fraction governs the diffusion of UCB into tissues, and therefore Bf is responsible for both its beneficial and toxic effects on cells. Although, UCB was long thought to be a non-functional waste product, recent studies have shown that the antioxidant effects of mildly elevated serum bilirubin levels, as well as activation of heme oxygenase, may protect against diseases associated with oxidative stress, such as atherosclerosis. By contrast, markedly elevated serum UCB levels may cause severe neurological damage, especially in neonates. The regulation of cellular UCB content, by its conjugation, oxidation, and export, are, therefore of paramount importance to cellular health.
Bilirubin oxidases, a sub class of the Multicopper oxidases family, were discovered in 1981 by Tanaka and Murao (Murao and Tanaka, 1981) and first used for the detection of bilirubin. Since 2001 and ...the pioneering work of Tsujimura, these BODs have attracted a lot of attention for the reduction of O2. Unlike laccases, these BODs are stable in physiological conditions (20mM phosphate buffer, pH 7.4, 0.14M NaCl, 37°C) and more than 120 papers have been published in the last 7 years. Here, we will first briefly describe some general features of BODs and then review the use of BODs for bilirubin biosensors and the recent achievements and progress toward the elaboration of efficient O2 reducing cathodes.
•Bilirubin oxidases are a sub class of the Multicoppers oxidases family.•BODs have attracted a lot of interest with 116 published papers in the last 7 years.•We first describe some general features of Bilirubin Oxidases.•We review the use of BODs for bilirubin biosensors.•We review the use of BODs for the O2 reduction, either in DET or MET.