Comparison of expert and novice sonographers' performance in focused lung ultrasonography in dyspnea (FLUID) to diagnose patients with acute heart failure syndrome.

OBJECTIVES: The goal of this study was to examine the ability of emergency physicians who are not experts in emergency ultrasound (US) to perform lung ultrasonography and to identify B-lines. The hypothesis was that novice sonographers are able to perform lung US and identify B-lines after a brief intervention. In addition, the authors examined the diagnostic accuracy of B-lines in undifferentiated dyspneic patients for the diagnosis of acute heart failure syndrome (AHFS), using an eight-lung-zone technique as well as an abbreviated two-lung-zone technique. METHODS: This was a prospective, cross-sectional study of patients who presented to the emergency department (ED) with acute dyspnea from May 2009 to June 2010. Emergency medicine (EM) resident physicians, who received a 30-minute training course in thoracic US examinations, performed lung ultrasonography on patients presenting to the ED with undifferentiated dyspnea. They attempted to identify the presence or absence of sonographic B-lines in eight lung fields based on their bedside US examinations. An emergency US expert blinded to the diagnosis and patient presentation, as well as to the residents' interpretations of presence of B-lines, served as the criterion standard. A secondary outcome determined the accuracy of B-lines, using both an eight-lung-zone and a two-lung-zone technique, for predicting pulmonary edema from AHFS in patients presenting with undifferentiated dyspnea. Two expert reviewers who were blinded to the US results determined the clinical diagnosis of AHFS. RESULTS: A cohort of 66 EM resident physicians performed lung US on 380 patients with a range of 1 to 28 examinations, a mean of 5.8 examinations, and a median of three examinations performed per resident. Compared to expert interpretation, lung US to detect B-lines by inexperienced sonographers achieved the following test characteristics: sensitivity 85%, specificity 84%, positive likelihood ratio (+LR) 5.2, negative likelihood ratio (-LR) 0.2, positive predictive value (PPV) 64%, and negative predictive value (NPV) 94%. Regarding the secondary outcome, the final diagnosis was AHFS in 35% of patients (134 of 380). For novice sonographers, one positive lung zone (i.e., anything positive) had a sensitivity of 87%, a specificity of 49%, a +LR of 1.7, a -LR of 0.3, a PPV of 50%, and an NPV of 88% for predicting AHFS. When all eight lung zones were determined positive (i.e., totally positive) by novice sonographers, the sensitivity was 19%, specificity was 97%, +LR was 5.7, -LR was 0.8, PPV was 76%, and NPV was 68% for predicting AHFS. The areas under the curve for novice and expert sonographers were 0.77 (95% CI = 0.72 to 0.82) and 0.76 (95% CI = 0.71 to 0.82), respectively. CONCLUSIONS: Novice sonographers can identify sonographic B-lines with similar accuracy compared to an expert sonographer. Lung US has fair predictive value for pulmonary edema from acute heart failure in the hands of both novice and expert sonographers.

A pilot study examining the viability of a Prehospital Assessment with UltraSound for Emergencies (PAUSE) protocol.

BACKGROUND: Prehospital ultrasound has been shown to aid in the diagnosis of multiple conditions that do not generally change prehospital management. On the other hand, the diagnoses of cardiac tamponade, tension pneumothorax, or cardiac standstill may directly impact patient resuscitation in the field. STUDY OBJECTIVE: To determine if prehospital care providers can learn to acquire and recognize ultrasound images for several life-threatening conditions using the Prehospital Assessment with UltraSound for Emergencies (PAUSE) protocol. METHODS: This is a prospective, educational intervention pilot study at an urban fire department with integrated emergency medical services (EMS). We enrolled 20 emergency medical technicians--paramedic with no prior ultrasonography training. Subjects underwent a 2-h training session on basic ultrasonography of the lungs and heart to evaluate for pneumothorax, pericardial effusion, and cardiac activity. Subjects were tested on image interpretation as well as image acquisition skills. Two bedside ultrasound-trained emergency physicians scored images for adequacy. Image interpretation testing was performed using pre-obtained ultrasound clips containing normal and abnormal images. RESULTS: All subjects appropriately identified the pleural line, and 19 of 20 paramedics achieved a Cardiac Ultrasound Structural Assessment Scale score of ≥4. For the image interpretation phase, the mean PAUSE protocol video test score was 9.1 out of a possible 10 (95% confidence interval 8.6-9.6). CONCLUSION: Paramedics were able to perform the PAUSE protocol and recognize the presence of pneumothorax, pericardial effusion, and cardiac standstill. The PAUSE protocol may potentially be useful in rapidly detecting specific life-threatening pathology in the prehospital environment, and warrants further study in existing EMS systems.

Human transcription factor Sp3: genomic structure, identification of a processed pseudogene, and transcript analysis.

The human transcription factor Sp3 has been widely studied at the translational level and has been described as a regulatory factor for a number of genes. Sp3 is currently characterized as a bifunctional transcription factor having the ability to behave as both an activator and/or a repressor in various promoter regions. Previous translational studies have attempted to determine the basis for these diverse functions with mostly contradictory evidence to date. Little data are available, however, concerning genomic structure, full-length cDNA, potential transcript variants, or location of translation initiation sites for the large isoform of the Sp3 gene. In this study, bacterial artificial chromosome (BAC) sequencing, reverse transcription-polymerase chain reaction (RT-PCR), genomic PCR, and database mining indicate that the Sp3 gene encompasses seven exons spanning more than 55 kb of genomic DNA on Chromosome 2. The 5' end of this sequence contains a large CpG island. This work also detected a processed pseudogene, psiSp3, located on Chromosome 13, spanning approximately 4.0 kb. Northern blot analysis detected three predominant transcripts at 4.0, 6.0 and 2.5 kb. Sequence analysis indicated that alternative splicing of exon 3 allows for multiple transcripts of Sp3. Each sequenced transcript possesses three to five potential translation initiation sites. This diversity at the level of gene expression will likely be key to understanding the diverse functions of Sp3.

Role of an internal ribosome entry site in the translational control of the human transcription factor Sp3.

Sp1 and Sp3 are transcription factors involved in the regulation of numerous genes involved in oncogenesis. Sp3 is a bi-functional transcription factor with three different isoforms. Its bi-functional activity may in part be regulated by the relative expression of these isoforms. Northern blot analysis of Sp3 detects only a single transcript. Analysis of the known Sp3 cDNA sequence shows a high GC content and seven out-of-frame AUG codons located between the 5'-end of the mRNA and the two internal AUG initiation sites. This makes it highly unlikely that cap-recruited, translation initiation competent ribosomes could reach the internal start sites. A full human Sp3 expression construct was cloned. A bicistronic vector using Renilla and firefly luciferase showed internal ribosome entry site (IRES) activity in Sp3 RNA immediately 5' to the internal AUG sites. Also, the two smaller isoforms were translated more efficiently when full-length, uncapped transcripts were used, while the larger isoform was not translated. Mutants of Sp3 with AUG codons introduced 5' of the two internal start sites were generated. Results showed that they were unable to suppress the smaller isoforms in vitro. Furthermore, dual non-AUG to AUG mutations showed occlusion of the second introduced isoform (i.e., the isoform situated more 3') but not of the internally initiated isoforms. These experiments are consistent with IRES-mediated translation of the two smaller isoforms of Sp3. The presence of an IRES allows the possibility that Sp3 isoform ratios and activity are controlled at the translational level. This mechanism may allow cells to control the expression of numerous genes during mitosis and, thus, have profound effects on cell cycle regulation and tumorigenesis.