Case report: Intrapulmonary tidal volumes in a preterm infant with chest wall rigidity

BACKGROUND Chest wall rigidity is a known side effect of fentanyl use, which is why fentanyl is usually combined with a muscle relaxant such as mivacurium. Verifying endotracheal intubation is difficult in case of a rigid chest wall. CASE PRESENTATION We present the case of a preterm infant (29 completed weeks gestation, birth weight 1,150 g) with a prolonged chest wall rigidity after fentanyl administration for intubation despite adequate doses of mivacurium. This resulted in a pronounced desaturation without any effect on heart rate. Clinically, the infant showed no chest wall movement despite intubation and common tools to verify intubation (including end-tidal carbon dioxide measurement and auscultation) were inconclusive. However, using electrical impedance tomography (EIT), we were able to demonstrate minimal tidal volumes at lung level and thereby, EIT was able to accurately show correct placement of the endotracheal tube. CONCLUSIONS This case may increase vigilance for fentanyl-induced chest wall rigidity in the neonatal population even when simultaneously administering mivacurium. Higher airway pressures exceeding 30 mmHg and the use of μ-receptor antagonists such as naloxone should be considered to reverse opioid-induced chest wall rigidity. Most importantly, our data may imply a relevant clinical benefit of using EIT during neonatal intubation as it may accurately show correct endotracheal tube placement

A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in Medicago truncatula

<p>Abstract</p> <p>Background</p> <p><it>Medicago truncatula </it>is a model legume species that is currently the focus of an international genome sequencing effort. Although several different oligonucleotide and cDNA arrays have been produced for genome-wide transcript analysis of this species, intrinsic limitations in the sensitivity of hybridization-based technologies mean that transcripts of genes expressed at low-levels cannot be measured accurately with these tools. Amongst such genes are many encoding transcription factors (TFs), which are arguably the most important class of regulatory proteins. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) is the most sensitive method currently available for transcript quantification, and one that can be scaled up to analyze transcripts of thousands of genes in parallel. Thus, qRT-PCR is an ideal method to tackle the problem of TF transcript quantification in Medicago and other plants.</p> <p>Results</p> <p>We established a bioinformatics pipeline to identify putative TF genes in <it>Medicago truncatula </it>and to design gene-specific oligonucleotide primers for qRT-PCR analysis of TF transcripts. We validated the efficacy and gene-specificity of over 1000 TF primer pairs and utilized these to identify sets of organ-enhanced TF genes that may play important roles in organ development or differentiation in this species. This community resource will be developed further as more genome sequence becomes available, with the ultimate goal of producing validated, gene-specific primers for all Medicago TF genes.</p> <p>Conclusion</p> <p>High-throughput qRT-PCR using a 384-well plate format enables rapid, flexible, and sensitive quantification of all predicted Medicago transcription factor mRNAs. This resource has been utilized recently by several groups in Europe, Australia, and the USA, and we expect that it will become the 'gold-standard' for TF transcript profiling in <it>Medicago truncatula</it>.</p

A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in -0

T ampification. The derivative of fluorescence intensity is shown on the y-axis. Separation of PCR products on 3% (v/w) agarose gels following electrophoresis (C) confirmed the presence of unique amplicons of the expected size for most reactions. Few reactions yielded no products (indicated by arrow).<p><b>Copyright information:</b></p><p>Taken from "A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in "</p><p>http://www.plantmethods.com/content/4/1/18</p><p>Plant Methods 2008;4():18-18.</p><p>Published online 8 Jul 2008</p><p>PMCID:PMC2490690.</p><p></p

A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in -1

045 TF primer pairs (right).<p><b>Copyright information:</b></p><p>Taken from "A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in "</p><p>http://www.plantmethods.com/content/4/1/18</p><p>Plant Methods 2008;4():18-18.</p><p>Published online 8 Jul 2008</p><p>PMCID:PMC2490690.</p><p></p

A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in -2

Resis on 3% (v/w) agarose gels (A) and by dissociation curves with a single peak (B to D). Typical real-time RT-PCR amplification plots of three reference gene transcripts (E to G).<p><b>Copyright information:</b></p><p>Taken from "A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in "</p><p>http://www.plantmethods.com/content/4/1/18</p><p>Plant Methods 2008;4():18-18.</p><p>Published online 8 Jul 2008</p><p>PMCID:PMC2490690.</p><p></p

A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in -3

Nt organs with three replicate measurements of each cDNA preparation. A low value for the average expression stability M, as calculated by geNORM software, indicates more stable expression throughout the various organs.<p><b>Copyright information:</b></p><p>Taken from "A community resource for high-throughput quantitative RT-PCR analysis of transcription factor gene expression in "</p><p>http://www.plantmethods.com/content/4/1/18</p><p>Plant Methods 2008;4():18-18.</p><p>Published online 8 Jul 2008</p><p>PMCID:PMC2490690.</p><p></p