Born into an isolating world: family-centred care for babies born to mothers with COVID-19.

Background: The benefits of facilitating breastmilk feeding and close contact between mother and neonate (family-centred care; FCC) in the perinatal period are well-established. The aim of this study was to determine how the delivery of FCC practices were impacted for neonates born to mothers with perinatal SARS-CoV-2 infection during the COVID-19 pandemic. Methods: Neonates born to mothers with confirmed SARS-CoV-2 infection during pregnancy were identified from the 'EsPnIC Covid paEdiatric NeonaTal REgistry' (EPICENTRE) multinational cohort between 10 March 2020 and 20 October 2021. The EPICENTRE cohort collected prospective data on FCC practices. Rooming-in and breastmilk feeding practice were the main outcomes, and factors influencing each were determined. Other outcomes included mother-baby physical contact prior to separation and the pattern of FCC components relative to time and local site guidelines. Findings: 692 mother-baby dyads (13 sites, 10 countries) were analysed. 27 (5%) neonates were positive for SARS-CoV-2 (14 (52%) asymptomatic). Most sites had policies that encouraged FCC during perinatal SARS-CoV-2 infection for most of the reporting period. 311 (46%) neonates roomed-in with their mother during the admission. Rooming-in increased over time from 23% in March-June 2020 to 74% in January-March 2021 (boreal season). 330 (93%) of the 369 separated neonates had no FCC physical contact with their mother prior, and 319 (86%) were asymptomatic. Maternal breastmilk was used for feeding in 354 (53%) neonates, increasing from 23% to 70% between March-June 2020 and January-March 2021. FCC was most impacted when mothers had symptomatic COVID-19 at birth. Interpretation: This is the largest report of global FCC practice during the COVID-19 pandemic to date. The COVID-19 pandemic may have impacted FCC despite low perinatal transmission rates. Fortunately, clinicians appear to have adapted to allow more FCC delivery as the COVID-19 pandemic progressed. Funding: The National Health and Medical Research Council (Australia): Grant ID 2008212 (DGT), Royal Children's Hospital Foundation: Grant ID 2019-1155 (EJP), Victorian Government Operational Infrastructure Support Program.

Difficult airway management algorithms: a directed review.

The primary aim of this study was to identify, describe and compare the content of existing difficult airway management algorithms. Secondly, we aimed to describe the literature reporting the implementation of these algorithms. A directed search across three databases (MEDLINE, Embase and Scopus) was performed. All articles were screened for relevance to the research aims and according to pre-determined exclusion criteria. We identified 38 published airway management algorithms. Our results show that most facemask employ a four-step process as represented by a flow chart, with progression from tracheal intubation, facemask ventilation and supraglottic airway device use, to a rescue emergency surgical airway. The identified algorithms are overwhelmingly similar, yet many use differing terminology. The frequency of algorithm publication has increased recently, yet adherence and implementation outcome data remain limited. Our results highlight the lack of a single algorithm that is universally endorsed, recognised and applicable to all difficult airway management situations.

In vivo corrosion, tumor outcome, and microarray gene expression for two types of muscle-implanted tungsten alloys.

Tungsten alloys are composed of tungsten microparticles embedded in a solid matrix of transition metals such as nickel, cobalt, or iron. To understand the toxicology of these alloys, male F344 rats were intramuscularly implanted with pellets of tungsten/nickel/cobalt, tungsten/nickel/iron, or pure tungsten, with tantalum pellets as a negative control. Between 6 and 12 months, aggressive rhabdomyosarcomas formed around tungsten/nickel/cobalt pellets, while those of tungsten/nickel/iron or pure tungsten did not cause cancers. Electron microscopy showed a progressive corrosion of the matrix phase of tungsten/nickel/cobalt pellets over 6 months, accompanied by high urinary concentrations of nickel and cobalt. In contrast, non-carcinogenic tungsten/nickel/iron pellets were minimally corroded and urinary metals were low; these pellets having developed a surface oxide layer in vivo that may have restricted the mobilization of carcinogenic nickel. Microarray analysis of tumors revealed large changes in gene expression compared with normal muscle, with biological processes involving the cell cycle significantly up-regulated and those involved with muscle development and differentiation significantly down-regulated. Top KEGG pathways disrupted were adherens junction, p53 signaling, and the cell cycle. Chromosomal enrichment analysis of genes showed a highly significant impact at cytoband 7q22 (chromosome 7) which included mouse double minute (MDM2) and cyclin-dependant kinase (CDK4) as well as other genes associated with human sarcomas. In conclusion, the tumorigenic potential of implanted tungsten alloys is related to mobilization of carcinogenic metals nickel and cobalt from corroding pellets, while gene expression changes in the consequent tumors are similar to radiation induced animal sarcomas as well as sporadic human sarcomas.

I.V. acetaminophen pharmacokinetics in neonates after multiple doses.

BACKGROUND: Pharmacokinetics of an i.v. prodrug of acetaminophen (propacetamol) in neonates after repeat dosing are reported, with scant data for i.v. acetaminophen formulation. METHODS: Neonates from an intensive care unit received 6-hourly prn i.v. acetaminophen dosed according to postmenstrual age (PMA): 28-32 weeks, 10 mg kg(-1); 32-36 weeks, 12.5 mg kg(-1); and > or =36 weeks, 15 mg kg(-1). A maximum of five blood samples for assay and liver function tests (LFTs) were collected. A one-compartment linear disposition model (zero-order input; first-order elimination) was used to describe time-concentration profiles using population modelling (NONMEM). RESULTS: Fifty neonates, median (range) PMA 38.6 (32-45) weeks, mean (SD) weight 2.9 (0.7) kg, received a mean of 15 doses over a median 4 days with 189 serum acetaminophen and 231 LFT measurements. Standardized population parameter estimates for a term neonate were clearance (CL) 5.24 (CV 30.5%) litre h(-1) 70 kg(-1) and volume of distribution (V) 76 (29.6%) litre 70 kg(-1). CL increased with PMA from 4.4 litre h(-1) 70 kg(-1) at 34 weeks to 6.3 litre h(-1) 70 kg(-1) at 46 weeks. The presence of unconjugated hyperbilirubinaemia was associated with reduced CL: 150 micromol litre(-1) associated with 40% CL reduction. Acetaminophen concentrations between 10 and 23 mg litre(-1) at steady state are predicted after 15 mg kg(-1) 6-hourly for a neonate of PMA 40 weeks. Hepatic enzyme analysis of daily samples changed significantly for one patient whose alanine aminotransferase concentration tripled. CONCLUSIONS: The parameter estimates are similar to those described for propacetamol. There was no evidence of hepatotoxicity. Unconjugated hyperbilirubinaemia impacts upon CL, dictating dose reduction.

Quantitative analysis of gemcitabine triphosphate in human peripheral blood mononuclear cells using weak anion-exchange liquid chromatography coupled with tandem mass spectrometry.

Gemcitabine triphosphate (dFdCTP) is a highly active metabolite of gemcitabine. It is formed intra-cellularly via the phosphorylation of gemcitabine by deoxycytidine kinase. The monitoring of dFdCTP in human peripheral blood mononuclear cells (PBMCs), in addition to plasma concentrations of gemcitabine and its metabolite 2',2'-difluorodeoxyuridine, is considered very useful in determining pharmacokinetic-pharmacodynamic relationships. We describe a novel sensitive assay for the quantification of dFdCTP in human PBMCs. The method is based on weak anion-exchange liquid chromatography and detection with tandem mass spectrometry (LC-MS/MS). The assay has been validated from 1 ng/ml (lower limit of quantification, LLOQ) to 25 ng/ml (upper limit of quantification, ULOQ) using 180 microl aliquots of PBMC extracts containing approximately 0.648 mg protein or 3.8 x 10(6) lysed PBMCs. The LLOQ is equivalent to 94 fmol/10(6) cells (1 ng/ml = 0.18 ng/180 microl or 0.18 ng/0.648 mg protein = 0.047 ng/10(6) cells or 94 fmol/10(6) cells). This highly sensitive assay is capable of quantifying about 200-fold lower concentrations of dFdCTP in human PBMCs than currently available methods.

Preclinical characterization of 2-[3-[3-[(5-ethyl-4'-fluoro-2-hydroxy[1,1'-biphenyl]-4-yl)oxy]propoxy]-2-propylphenoxy]benzoic acid metabolism: in vitro species comparison and in vivo disposition in rats.

Assessment of the pharmacokinetics of [14C]2-[3-[3-[(5-ethyl-4'-fluoro-2-hydroxy[1,1'-biphenyl]-4-yl)oxy]propoxy]-2-propylphenoxy-]benzoic acid ([14C]LY293111), an experimental anti-cancer agent, suggested long-lived circulating metabolites in rats. In vivo metabolites of LY293111 were examined in plasma, bile, urine, and feces of Fischer 344 (F344) rats after oral administration of [14C]LY293111. Metabolites were profiled by high-performance liquid chromatography-radiochromatography, and identified by liquid chromatography (LC)/mass spectrometry and LC/NMR. The major in vivo metabolites of LY293111 identified in rats were phenolic (ether), acyl, and bisglucuronides of LY293111. Measurement of radioactivity in rat plasma confirmed that a fraction of LY293111-derived material was irreversibly bound to plasma protein and that this bound fraction increased over time. This was consistent with the observed disparity in half-lives between LY293111 and total radioactivity in rats and monkeys, and is likely due to covalent modification of proteins by the acyl glucuronide. In vitro metabolism of [14C]LY293111 in liver slices from CD-1 mice, F344 rats, rhesus and cynomolgus monkeys, and humans indicates that glucuronidation was the primary metabolic pathway in all species. The acyl glucuronide was the most prevalent radioactive peak (16% of total 14C) produced by F344 rat slices, whereas the ether glucuronide was the major metabolite in all other species (26-36% of total 14C). Several minor hydroxylated metabolites were detected in F344 rat slice extracts but were not observed in other species. The data presented suggest that covalent modification of proteins by LY293111 acyl glucuronide is possible in multiple species, although the relative reactivity of this metabolite appears to be low compared with those known to cause adverse drug reactions.

Towards environmental toxicogenomics -- development of a flow-through, high-density DNA hybridization array and its application to ecotoxicity assessment.

Assessment of the environmental hazard posed by soils/sediments containing low to moderate levels of contaminants using standard analytical chemical methods is uncertain due (in part) to a lack of information on contaminant bioavailability, the unknown interactive effects of contaminant mixtures, our inability to determine the species of a metal in an environmental matrix, and the relative sensitivity of bioassay species. Regulatory agencies compensate for this uncertainty by lowering cleanup goals, but in this process they effectively exclude otherwise attractive cleanup options (i.e. bioremediation). Direct evaluations of soil and sediment toxicity preclude uncertainty from most of these sources. However, the time and cost of chronic toxicity tests limits their general application to higher levels of tiered toxicity assessments. Transcriptional level (mRNA) toxicity assessments offer great advantages in terms of speed, cost and sample throughput. These advantages are currently offset by questions about the environmental relevance of molecular level responses. To this end a flow-through, high-density DNA hybridization array (genosensor) system specifically designed for environmental risk assessment was developed. The genosensor is based on highly regular microchannel glass wafers to which gene probes are covalently bound at discrete (200-microm diameter spot) and addressable (250-microm spot pitch) locations. The flow-through design enables hybridization and washing times to be reduced from approximately 18 h to 20 min. The genosensor was configured so that DNA from 28 environmental samples can be simultaneously hybridized with up to 64 different gene probes. The standard microscopic slide format facilitates data capture with most automated array readers and, thus high sample throughput (> 350 sample/h). In conclusion, hardware development for molecular analysis is enabling very tractable means for analyzing RNA and DNA. These developments have underscored the need for further developmental work in probe design software, and the need to relate transcriptional level data to whole-organism toxicity indicators.

Succession of phenotypic, genotypic, and metabolic community characteristics during in vitro bioslurry treatment of polycyclic aromatic hydrocarbon-contaminated sediments.

Dredged harbor sediment contaminated with polycyclic aromatic hydrocarbons (PAHs) was removed from the Milwaukee Confined Disposal Facility and examined for in situ biodegradative capacity. Molecular techniques were used to determine the successional characteristics of the indigenous microbiota during a 4-month bioslurry evaluation. Ester-linked phospholipid fatty acids (PLFA), multiplex PCR of targeted genes, and radiorespirometry techniques were used to define in situ microbial phenotypic, genotypic, and metabolic responses, respectively. Soxhlet extractions revealed a loss in total PAH concentrations of 52%. Individual PAHs showed reductions as great as 75% (i.e., acenapthene and fluorene). Rates of (14)C-PAH mineralization (percent/day) were greatest for phenanthrene, followed by pyrene and then chrysene. There was no mineralization capacity for benzo[a]pyrene. Ester-linked phospholipid fatty acid analysis revealed a threefold increase in total microbial biomass and a dynamic microbial community composition that showed a strong correlation with observed changes in the PAH chemistry (canonical r(2) of 0.999). Nucleic acid analyses showed copies of genes encoding PAH-degrading enzymes (extradiol dioxygenases, hydroxylases, and meta-cleavage enzymes) to increase by as much as 4 orders of magnitude. Shifts in gene copy numbers showed strong correlations with shifts in specific subsets of the extant microbial community. Specifically, declines in the concentrations of three-ring PAH moieties (i.e., phenanthrene) correlated with PLFA indicative of certain gram-negative bacteria (i.e., Rhodococcus spp. and/or actinomycetes) and genes encoding for naphthalene-, biphenyl-, and catechol-2,3-dioxygenase degradative enzymes. The results of this study suggest that the intrinsic biodegradative potential of an environmental site can be derived from the polyphasic characterization of the in situ microbial community.

In vivo acetylcholinesterase inhibition, metabolism, and toxicokinetics of aldicarb in channel catfish: role of biotransformation in acute toxicity.

The carbamate pesticide, aldicarb, demonstrates significant acute toxicity in mammals, birds, and fish through the inhibition of acetylcholinesterase (AChE), and may present high potential for exposure of aquatic organisms during periods of runoff. Toxicity studies have shown that channel catfish are less sensitive to the acute toxic effects of aldicarb than are rainbow trout or bluegill. An earlier in vitro study suggests that the aldicarb resistance in catfish may be related to a low level of bioactivation to the potent aldicarb sulfoxide. The current study examines the toxicity, AChE inhibition, plasma kinetics, and in vivo metabolism of aldicarb in channel catfish. A 48-h LC50 of 9.7 mg/l was determined for juvenile channel catfish. Mortality was accompanied by dramatic loss of brain AChE. Further characterization of tissue-level effects suggests that muscle AChE plays a causal role in mortality. Aldicarb was metabolized in channel catfish to aldicarb sulfoxide, along with the formation of minor hydrolytic products. The toxicokinetics of aldicarb in catfish are bi-compartmental with rapid elimination (t1/2 = 1.9 h). Plasma AChE was inhibited in a pattern similar to that of the elimination of total aldicarb-derived compounds. A comparison of aldicarb uptake between catfish and rainbow trout showed no difference in compound absorbed in 24 h. The pattern of in vivo metabolism, however, was quite different between these species. Rainbow trout produce significantly more hydrolytic derivatives and have a 3-fold higher aldicarb sulfoxide to aldicarb ratio at 3 h. These data give strength to the hypothesis that a slower rate of bioactivation in the catfish (vs. rainbow trout) is acting as a protective mechanism against the acute toxicity of aldicarb.

In vitro sulfoxidation of aldicarb by hepatic microsomes of channel catfish, Ictalurus punctatus.

The carbamate pesticide, aldicarb, demonstrates significant acute toxicity in mammals, birds, and fish, and is readily biotransformed by most organisms studied. Metabolic products of aldicarb include the more toxic sulfoxide and the less toxic sulfone as two of the major products. Both the cytochrome P450 (CYP) and the flavin monooxygenase systems (FMO) are involved in this process. This study examined the capacities of liver microsomes of male channel catfish (Ictalurus punctatus), which lack FMO, to biotransform aldicarb in vitro. In addition, the acetylcholinesterase inhibitory potencies of aldicarb and its sulfoxide and sulfone derivatives were determined. For metabolism studies, incubations of [14C]-aldicarb (0.1mM) were carried out for up to 15-90 min using 1.0 mg/mL of hepatic microsomal protein. Total NADPH- dependent biotransformation was low (< 3.0% conversion to polar metabolites), and was inhibited by carbon monoxide. The only metabolite detected was aldicarb sulfoxide (Kmapp = 53.8 +/- 25.3 microM; Vmaxapp = 0.040 +/- 0.007 nmol/min/mg). Treatment of fish with the CYP modulators beta-naphthoflavone (BNF, 50 mg/kg) and ethanol (EtOH, 1.0% aqueous) had no effect on sulfoxide production. No correlation existed between CYP isoform expression (determined by western blot) and aldicarb sulfoxidation rates, suggesting the involvement of an unmeasured CYP isoform or involvement of several isoforms with low specificity. This study indicates that a low rate of bioactivation of aldicarb to aldicarb sulfoxide may be responsible for the resistance of channel catfish to aldicarb toxicity relative to that of other piscine species.

Immunochemical characterization of hepatic cytochrome P450 isozymes in the channel catfish: assessment of sexual, developmental and treatment-related effects.

The profiles of immunoreactive proteins recognized by antibodies raised against purified trout P-450 isoforms (CYP1A1, CYP2M1 and CYP2K1) were examined in channel catfish liver by Western blot analysis. Gender differences in basal expression of these isoforms, as well as responses to known inducers of mammalian isoforms (ethanol, beta-naphthoflavone and clofibric acid) and early life stage (3 and 6 months) profiles are described. Two similar protein bands were detected by Western blotting in mature untreated catfish with CYP2K1 and CYP2M1 antibodies. A third band is detected by anti-2K1 in fish treated with beta-naphthoflavone; this band was verified as CYP1A, with about twice the level of expression in males versus females. No difference between sexes was seen in the expression of the 51-kDa CYP2-reactive bands; however, a significant difference (female > male) was seen in the lower molecular weight CYP2 band (47-kDa). Ethanol treatment caused a dose-dependent decrease in the 47-kDa CYP2-reactive isoforms but no change in the 51-kDa band. Clofibric acid treatment caused an increase in both the 51-kDa CYP2 protein as well as in liver somatic index. Age-dependent changes in isoform expression were also detected in CYP2-reactive forms, with a novel protein (53-kDa) detected in 3-month-old fish. The results from this study provide insight into the regulation of constitutive catfish CYP isoforms and prepares a foundation for further examination of the biotransformation capabilities of an important aquatic species.

Detection of trichloroethylene-protein adducts in rat liver and plasma.

Trichloroethylene is an industrial chemical with widespread occupational exposure and is a major environmental contaminant. In a Western blot using antiserum that recognizes trichloroethylene covalently bound to protein, a single 50 kDa microsomal adduct was detected in the livers of trichloroethylene-treated Sprague-Dawley rats. To determine if trichloroethylene-protein adducts could be detected in blood, plasma proteins were immunoaffinity purified using an antidichloroacetyl column. A single 50 kDa protein was detected in the affinity-purified fraction in a Western blot using dichloroacetyl antiserum. This protein was also immunochemically reactive with anti-cytochrome P450 2E1 antibodies. The 50 kDa trichloroethylene-protein adduct may be formed in the liver and released into the blood following exposure to trichloroethylene. The significance of adduct formation with respect to trichloroethylene toxicity remains to be established; however, the data suggest that this approach may be useful in the investigation of trichloroethylene-protein adducts and adverse effects following exposure.

Organization and sequence analysis of the 2,4-dichlorophenol hydroxylase and dichlorocatechol oxidative operons of plasmid pJP4.

Growth of Alcaligenes eutrophus JMP134 on 2,4-dichlorophenoxyacetate requires a 2,4-dichlorphenol hydroxylase encoded by gene tfdB. Catabolism of either 2,4-dichlorophenoxyacetate or 3-chlorobenzoate involves enzymes encoded by the chlorocatechol oxidative operon consisting of tfdCDEF, which converts 3-chloro- and 3,5-dichlorocatechol to maleylacetate and chloromaleylacetate, respectively. Transposon mutagenesis has localized tfdB and tfdCDEF to EcoRI fragment B of plasmid pJP4 (R. H. Don, A. J. Wieghtman, H.-J. Knackmuss, and K. N. Timmis, J. Bacteriol. 161:85-90, 1985). We present the complete nucleotide sequence of tfdB and tfdCDEF contained within a 7,954-base-pair HindIII-SstI fragment from EcoRI fragment B. Sequence and expression analysis of tfdB in Escherichia coli suggested that 2,4-dichlorophenol hydroxylase consists of a single subunit of 65 kilodaltons. The amino acid sequences of proteins encoded by tfdD and tfdE were found to be 63 and 53% identical to those of functionally similar enzymes encoded by clcB and clcD, respectively, from plasmid pAC27 of Pseudomonas putida. P. putida(pAC27) can utilize 3-chlorocatechol but not dichlorinated catechols. A region of DNA adjacent to clcD in pAC27 was found to be 47% identical in amino acid sequence to tfdF, a gene important in catabolizing dichlorocatechols. The region in pAC27 does not appear to encode a protein, suggesting that the absence of a functional trans-chlorodienelactone isomerase may prevent P. putida(pAC27) from utilizing 3,5-dichlorocatechol.

Duplication of a 2,4-dichlorophenoxyacetic acid monooxygenase gene in Alcaligenes eutrophus JMP134(pJP4).

The Alcaligenes eutrophus JMP134 plasmid pJP4 contains genes necessary for the complete degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) and 3-chlorobenzoic acid. tfdA encodes 2,4-D monooxygenase, the initial enzyme in the 2,4-D catabolic pathway. The tfdA locus has recently been localized to a region on pJP4 13 kilobases away from a cluster of five genes, tfdB to tfdF, which encode the enzymes responsible for the further degradation of 2,4-D to chloromaleylacetic acid (W.R. Streber, K. N. Timmis, and M. H. Zenk, J. Bacteriol. 169:2950-2955, 1987). A second, dissimilar locus on pJP4, tfdAII, has been observed which encodes 2,4-D monooxygenase activity. Gas chromatographic analysis of the 2,4-D metabolites of A. eutrophus harboring pJP4 or subclones thereof localized tfdAII to within a 9-kilobase SstI fragment of pJP4 which also carries the genes tfdBCDEF. This fragment was further characterized in Escherichia coli by deletion and subcloning analysis. A region of 2.5 kilobases, adjacent to tfdC, enabled E. coli extracts to degrade 2,4-D to 2,4-dichlorophenol. Hybridization under low-stringency conditions was observed between tfdA and tfdAII, signifying that the 2,4-D monooxygenase gene was present as two related copies on pJP4.

Chlorophyll a biosynthetic routes and chlorophyll a chemical heterogeneity in plants.

A six-branched chlorophyll a biosynthetic pathway instead of a four-branched pathway has been proposed as being responsible for the formation of chlorophyll a in green plants. The several biosynthetic routes that make up the pathway have been described as leading to the formation of ten chemically different groups of chlorophyll a species. The latter differ from one another by one or more of the following modifications: (a) by having a vinyl or ethyl group at position 4 of the macrocycle, (b) by the nature of the long-chain fatty alcohols at position 7 of the macrocycle, and (c) by having a 6-membered lactone ring instead of a 5-membered cyclopentanone ring. The chemical structure of several of the metabolic intermediates of that pathway and of some of the chlorophyll a species have now been determined by primary chemical derivatization methods coupled to spectrofluorometric, nuclear magnetic resonance and mass spectral analyses. The formation of highly organized photosynthetic membranes in which some of the chlorophyll alpha molecules are specifically oriented is ascribed to the multiplicity of chlorophyll biosynthetic routes which result in the formation of multiple chlorophyll alpha chemical species. Proper orientation of chlorophyll in the photosynthetic membranes is visualized as being controlled by peripheral group modifications that either modulate the polarity of the Chl chromophore or control the magnitude of the net positive charge on the central Mg atom. Finally it is proposed that in addition to the proper orientation of chlorophyll a, chemical heterogeneity of the chlorophyll chromophores in the photosynthetic reaction centers is mandatory for efficient charge separation, and proper vectorial electron transfer.

The need for sublethal studies.

In problems of waste management, the preoccupation of the would-be manager is the means whereby waste may be released to the environment without impairing the health of the biota inhabiting the receiving waters. In such a situation, measurements based upon acute poisoning are unhelpful since they tell nothing of the impact that the much lower concentrations found at some distance from the waste source have upon the ability of the affected organisms to undertake the responses necessary to ensure survival and more particularly to reproduce successfully. Such responses can only be investigated with organisms not at the point of death, i.e. in truly sublethal studies.