The Clinical Usefulness of the SD Bioline Influenza Antigen Test® for Detecting the 2009 Influenza A (H1N1) Virus

Though the 2009 worldwide influenza A (H1N1) pandemic has been declared to have ended, the influenza virus is expected to continue to circulate from some years as a seasonal influenza. A rapid antigen test (RAT) can aid in rapid diagnosis and allow for early antiviral treatment. We evaluated the clinical usefulness of RAT using SD Bioline Influenza Antigen Test® kit to detect the influenza virus, considering various factors. From August 1, 2009 to October 10, 2009, a total of 938 patients who visited the outpatient clinic at Korea University Guro Hospital with influenza-like illnesses were enrolled in the study. Throat or nasopharyngeal swab specimens were obtained from each of the patients. Using these specimens, we evaluated the influenza detection rate by rapid antigen test based on the real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) method. In comparison with rRT-PCR, the sensitivity and specificity of the RAT were 44.0% and 99.9%, respectively. The cyclic threshold values of RAT negative specimens were higher than RAT positive specimens (30.1±3.1 vs. 28.3±3.9, p=0.031). The sensitivity of the RAT kit was higher in patients who visited clinics within two days of symptom onset (60.4% vs. 11.1%, p=0.026). The results of this study show that the RAT cannot be recommended for general use in all patients with influenza-like illness because of its low sensitivity. The RAT may be used, only in the settings with limited diagnostic resources, for patients who visit a clinic within two days of symptom onset

N-terminal Pro-Brain Natriuretic Peptide Levels Predict Left Ventricular Systolic Function in Patients with Chronic Kidney Disease

N-terminal pro-brain natriuretic peptide (NT-proBNP) can be a useful marker for left ventricular (LV) dysfunction in patients without kidney disease. This study was conducted to clarify the relationship between NT-proBNP and LV systolic function in patients with decreased renal function. We studied 256 chronic kidney disease (CKD) patients, patients on dialysis were excluded. The median glomerular filtration rate was 24 (13-36) mL/min/1.73 m2 and the median NT-proBNP was 4,849 (1,310-19,009) pg/mL. The prevalence of LV systolic dysfunction increased from the lower to the upper NT-proBNP quartiles (I, 17%; II, 34%; III, 61%; and IV, 72%; p<0.001 for trend). The NT-proBNP quartile was an independent predictor of LV systolic dysfunction after adjustment for renal function, compared with quartile I: II, odds ratio (OR) 3.99 (95% confidence interval [CI],1.34-11.93); III, OR 11.28 (95% CI, 3.74-33.95); and IV, OR 36.97 (95% CI, 11.47-119.1). Area under the curve and optimum cut points for NT-proBNP to detect LV systolic dysfunction were 0.781 and 2,165 pg/mL in CKD stage 3, 0.812 and 4,740 pg/mL in CKD stage 4, and 0.745 and 15,892 pg/mL in CKD stage 5. The NT-proBNP level was a predictor of LV systolic dysfunction in CKD patients. Optimum cut points should be stratified according to renal function

Correlative microscopy of the constituents of a dinosaur rib fossil and hosting mudstone: Implications on diagenesis and fossil preservation

<div><p>We have applied correlative microscopy to identify the key constituents of a dorsal rib fossil from <i>Koreanosaurus boseongensis</i> and its hosting mudstone discovered at the rich fossil site in Boseong, South Korea, to investigate the factors that likely contributed to diagenesis and the preservation of fossil bone. Calcite and illite were the commonly occurring phases in the rib bone, hosting mudstone, and the boundary region in-between. The boundary region may have contributed to bone preservation once it fully formed by acting as a protective shell. Fluorapatite crystals in the rib bone matrix signified diagenetic alteration of the original bioapatite crystals. While calcite predominantly occupied vascular channels and cracks, platy illite crystals widely occupied miniscule pores throughout the bone matrix. Thorough transmission electron microscopy (TEM) study of illite within the bone matrix indicated the solid-state transformation of 1M to 2M without composition change, which was more evident from the lateral variation of 1M to 2M within the same layer. The high level of lattice disordering of 2M illite suggested an early stage of 1M to 2M transformation. Thus, the diagenetic alteration of both apatite and illite crystals within the bone matrix may have increased its overall density, as the preferred orientation of apatite crystals from moderate to strong degrees was evident despite the poor preservation of osteohistological features. The combined effects of rapid burial, formation of a boundary region, and diagenesis of illite and apatite within the bone matrix may have contributed to the rib bone preservation.</p></div

Composite optical micrographs of the main thin section under different light settings.

<p>(A) Cross-polarized light. (B) Polarized light with the lambda wave plate (530 nm) inserted. (C) Normal transmitted light. Although poorly preserved, osteohistological features are best observed under normal transmitted light as shown in the magnified images in (C).</p

An area showing lateral variation of the 1M-type illite and the 2M-type illite within the same layer.

<p>The gradual transformation of the 1M to 2M illite in a lateral direction is apparent. Note the highly disordered {00l} lattices of 2M from the HRTEM image.</p

Identified phases and their distributions in each region of the samples studied.

<p>Identified phases and their distributions in each region of the samples studied.</p

Composite cross-polarized optical micrograph of the main thin section (x40).

<p>The section was divided into three regions–hosting mudstone (yellow arrow), boundary (red arrow), and rib bone (blue arrow). Clusters of calcite microcrystals can be directly observed in all regions. The mudstone and boundary region primarily contains detrital clasts of quartz and feldspars. Due to the compressed nature of the bone matrix, specific osteohistological features were not discernible from the rib bone besides the vascularization pattern.</p

The interplanar spacings, and chemistry of representative clay phases from each region.

<p>The interplanar spacings, and chemistry of representative clay phases from each region.</p

Simplified illustration of the boundary region.

<p>The haphazard, reticular orientation of clay and the relatively abundant inclusion of quartz and albite clasts is a notable feature of this region. Clay concentration progressively increases towards the mudstone region, and a thin line of calcite microcrystals covers the bone surface. I = illite, V = vermiculite.</p

XRD analysis.

<p>(A) Main optical thin section (noise background removed). Major phases were calcite, quartz, albite, and fluorapatite. Vermiculite and illite were distinctly identified clay phases. (B) Hosting mudstone powder and rib bone powder focused on identifying clay phases. Clay phases besides illite were not detected from the rib bone sample. The prominent illite peaks at 20° range and the peaks in 24° range in the mudstone sample indicate that both 1M and 2M₁ illite polytypes are present. A = albite, C = calcite, F = fluorapatite, I = illite, K = kaolinite, Q = quartz, S = sanidine, V = vermiculite.</p