ABSTRACT
Injection of air under ultrasound guidance via a perineural catheter after insertion ("air test") has been described as a means to infer placement accuracy, yet this test has never been rigorously evaluated. We tested the hypothesis that the air test predicts accurate catheter location greater than chance and determined the test's sensitivity, specificity, and positive and negative predictive values using a porcine-bovine model and blinded expert in ultrasound-guided regional anesthesia. The air test improved the expert clinician's assessment of catheter tip position compared to chance, but there was no difference when compared to direct visualization of the catheter without air injection.
Subject(s)
Air/analysis , Anesthetics, Local/administration & dosage , Catheterization, Peripheral/methods , Nerve Block/methods , Peripheral Nerves/diagnostic imaging , Ultrasonography, Interventional/methods , Animals , Cattle , In Vitro Techniques , Infusions, Parenteral/methods , Peripheral Nerves/drug effects , Phantoms, Imaging , Reproducibility of Results , Sensitivity and Specificity , SwineABSTRACT
BACKGROUND: Biomarkers of fetal exposure to alcohol are important to establish so that early detection and intervention can be made on these infants to prevent undesirable outcomes. The aim of this study was to analyze long-chain fatty acid ethyl esters (FAEEs) in meconium as potential biomarkers of fetal alcohol exposure and effect. METHODS: Fatty acid ethyl esters were analyzed in the meconium of 124 singleton infants by positive chemical ionization gas chromatography/mass spectrometry (GC/MS) and correlated to maternal ethanol use. RESULTS: A total of 124 mother/infant dyads were enrolled in the study: 31 were in the control group and 93 were in the alcohol-exposed group. The incidence (28% vs 9.7%, p = 0.037) of ethyl linoleate detected in meconium was significantly higher in the alcohol-exposed groups than the control groups. Similarly, when the concentrations of ethyl linoleate in meconium were grouped (trichotomized), there was a significant linear by linear association between alcohol exposure and group concentrations of ethyl linoleate (p = 0.013). Furthermore, only alcohol-exposed infants were found in the group with the highest ethyl linoleate concentration. The sensitivity of ethyl linoleate in detecting prenatal alcohol exposure was only 26.9%, and its specificity and positive predictive value were 96.8 and 96.2%, respectively. There was no significant correlation between the concentration of ethyl linoleate in meconium and absolute alcohol consumed (oz) per drinking day across pregnancy, although a trend toward a positive correlation is seen at lower amounts of alcohol consumed. Among the polyunsaturated, long-chain FAEEs, there was weak evidence that the incidence (21.5% vs 6.5%, p = 0.057) and concentration (p = 0.064) of ethyl arachidonate (AA) were significantly higher in the alcohol-exposed groups than the control groups. Ethyl linolenate and ethyl docosahexanoate (DHA) in meconium were found only in the alcohol group, although not at statistically significant levels. Highly significant correlations were found among the concentrations of ethyl linoleate, ethyl linolenate, ethyl AA, and ethyl DHA in meconium (correlations ranged between rs = 0.203, p = 0.024; and rs = 0.594, p < 0.001). CONCLUSION: We conclude that FAEEs in meconium, particularly ethyl linoleate and ethyl AA, are biomarkers of high specificity for prenatal exposure to alcohol in newborn infants. We also propose that ethyl AA and DHA could be potential biomarkers of fetal alcohol effects on the developing fetal brain and should be investigated further.
Subject(s)
Esters/metabolism , Ethanol/pharmacology , Fatty Acids/metabolism , Fetus/drug effects , Meconium/metabolism , Adult , Alcohol Drinking/metabolism , Arachidonic Acids/metabolism , Biomarkers/metabolism , Female , Humans , Infant, Newborn , PregnancyABSTRACT
BACKGROUND: Plant development is exquisitely sensitive to light. Seedlings grown in the dark have a developmentally arrested etiolated phenotype, whereas in the light they develop leaves and complete their life cycle. Arabidopsis de-etiolated 1 (det1) mutants develop like light-grown seedlings even when grown in the dark. DET1 encodes a nuclear protein that appears to act downstream from multiple photoreceptors to regulate morphogenesis and gene expression in response to light. However, its function has remained unknown. RESULTS: We used microarrays to examine defects in transcription in dark-grown det1 seedlings. We found extensive changes in gene expression, including many of the transcriptional responses observed in light-treated wild-type seedlings. We used an epitope-tagging approach to determine the basis of DET1 function. GFP-DET1 rescues the det1 phenotype, is localized to the nucleus, and forms an approximately 350 kDa complex, which is required for full DET1 activity. We affinity-purified the DET1 complex and identified an approximately 120 kDa copurifying protein that is the plant homolog of UV-Damaged DNA Binding Protein 1 (DDB1), a protein implicated in the human disease xeroderma pigmentosa. A null mutation in Arabidopsis DDB1A results in no obvious phenotype on its own, yet it enhances the phenotype of a weak det1 allele. CONCLUSIONS: DET1 and DDB1 interact both biochemically and genetically. In animal cells, DDB1 interacts with histone acetyltransferase complexes. The DET1/DDB1 complex may regulate gene expression in response to light via recruitment of HAT activity. Thus, DET1, whose sequence is conserved in both animals and plants, may play a direct role in the regulation of many genes.
