Comparison Between Exclusively Long‐Axis and Multiple‐Axis Sonographic Protocols for Screening of Rotator Cuff Lesions in Symptomatic Shoulders

Objective. The purpose of this study was to determine whether exclusively long‐axis sonography differs from a multiple‐axis scanning protocol as a screening tool for rotator cuff lesions in symptomatic shoulders when compared with magnetic resonance imaging (MRI). Methods. A total of 509 consecutive patients (mean age, 52.8 years) referred for MRI were also routinely evaluated by sonography. We initially performed exclusively long‐axis sonography and graded the rotator cuff as normal or abnormal. Patients subsequently underwent a full sonographic protocol using multiple‐axis views. Magnetic resonance imaging findings were compared with sonographic findings for both techniques. Results. The overall accuracy of sonography was greater than 90%. We found divergent results from different sonographic techniques in 34 patients. Of these, 8 were multiple‐axis false‐negative; 14 were exclusively long‐axis false‐negative; 6 were exclusively long‐axis false‐positive; and 6 were multiple‐axis false‐positive. All cases with divergent false‐negative findings on multiple‐axis sonography showed tendinosis on MRI. Causes for false‐negative findings on exclusively long‐axis sonography included tendinosis and partial‐thickness tears of the supraspinatus. No statistically significant difference was seen between both sonographic techniques compared with MRI in terms of accuracy, sensitivity, specificity, positive predictive value, and negative predictive value (P > .05). Conclusions. Sonography is reliable for detecting rotator cuff abnormalities. Exclusively long‐axis sonography seems appropriate as a screening tool for rotator cuff lesions in symptomatic shoulders.     

Experimental design as a tool to evaluate chlorogenic and caffeic acids extracted from Cecropia glaziovii Sneth

The effects of different parameters, including ethanol concentration, time of drug:solvent contact, temperature and the presence of a preservative, on chlorogenic acid (CGA) and caffeic acid (CFA) yields in Cecropia glaziovii Sneth extracts were investigated using an experimental design. In order to quantify the phenolic acids in these extracts a high-performance liquid chromatography–diode array detection (HPLC–DAD) method was developed and validated. Extracts with 80% ethanol presented a higher CGA content, but low amounts of CFA. Extracts with 20% ethanol showed a higher CFA concentration, but a sharp reduction in CGA extraction yield. The presence of a preservative, under the same extraction conditions, resulted in a slight difference or no difference in the CGA and CFA extraction yields. When the temperature was controlled at refrigerator or room temperature, a slight alteration in the concentrations of the phenolics studied was observed. The present approach can be applied in order to determine the optimum conditions for the preparation of C. glaziovii Sneth extracts based on CGA or CFA extraction yield as a chemical marker.     

Partitioning of tissue expression accompanies multiple duplications of the Na+/K+ ATPase alpha subunit gene

Vertebrate genomes contain multiple copies of related genes that arose through gene duplication. In the past it has been proposed that these duplicated genes were retained because of acquisition of novel beneficial functions. A more recent model, the duplication-degeneration-complementation hypothesis (DDC), posits that the functions of a single gene may become separately allocated among the duplicated genes, rendering both duplicates essential. Thus far, empirical evidence for this model has been limited to the engrailed and sox family of developmental regulators, and it has been unclear whether it may also apply to ubiquitously expressed genes with essential functions for cell survival. Here we describe the cloning of three zebrafish alpha subunits of the Na(+),K(+)-ATPase and a comprehensive evolutionary analysis of this gene family. The predicted amino acid sequences are extremely well conserved among vertebrates. The evolutionary relationships and the map positions of these genes and of other alpha-like sequences indicate that both tandem and ploidy duplications contributed to the expansion of this gene family in the teleost lineage. The duplications are accompanied by acquisition of clear functional specialization, consistent with the DDC model of genome evolution.     

Noninvasive imaging of the vulnerable atherosclerotic plaque

Atherosclerosis is an inflammatory disease, complicated by progressively increasing atherosclerotic plaques that eventually may rupture. Plaque rupture is a major cause of cardiovascular events, such as unstable angina, myocardial infarction, and stroke. A number of noninvasive imaging techniques have been developed to evaluate the vascular wall in an attempt to identify so-called vulnerable atherosclerotic plaques that are prone to rupture. The purpose of the present review is to systematically investigate the accuracy of noninvasive imaging techniques in the identification of plaque components and morphologic characteristics associated with plaque vulnerability, assessing their clinical and diagnostic value.     

Reducing De Novo Donor-Specific Antibody Levels during Acute Rejection Diminishes Renal Allograft Loss

The effect of de novo DSA detected at the time of acute cellular rejection (ACR) and the response of DSA levels to rejection therapy on renal allograft survival were analyzed. Kidney transplant patients with acute rejection underwent DSA testing at rejection diagnosis with DSA levels quantified using Luminex single-antigen beads. Fifty-two patients experienced acute rejection with 16 (31%) testing positive for de novo DSA. Median follow-up was 27.0 ± 17.4 months postacute rejection. Univariate analysis of factors influencing allograft survival demonstrated significance for African American race, DGF, cytotoxic PRA >20% (current) and/or >50% (peak), de novo DSA, C4d and repeat transplantation. Multivariate analysis showed only de novo DSA (6.6-fold increased allograft loss risk, p = 0.017) to be significant. Four-year allograft survival was higher with ACR (without DSA) (100%) than mixed acute rejection (ACR with DSA/C4d) (65%) or antibody-mediated rejection (35%) (p < 0.001). Patients with >50% reduction in DSA within 14 days experienced higher allograft survival (p = 0.039). De novo DSAs detected at rejection are associated with reduced allograft survival, but prompt DSA reduction was associated with improved allograft survival. DSA should be considered a potential new end point for rejection therapy.     

Prognostic implications of a normal stress technetium-99m-tetrofosmin myocardial perfusion study in patients with a healed myocardial infarct and/or previous coronary revascularization

Previous studies have shown a good outcome for patients who present with normal findings on stress myocardial perfusion imaging. Currently, the prognostic implications of a normal study in patients who have a history of coronary artery disease (CAD) are not clear. This study investigated the long-term prognosis after a normal finding on stress technetium-99m (Tc-99m)-tetrofosmin single-photon emission computed tomography in patients with a history of CAD. The study included 147 consecutive patients with a history of CAD (previous myocardial infarction and/or myocardial revascularization), who underwent exercise bicycle or high-dose dobutamine-atropine stress Tc-99m-tetrofosmin single-photon emission computed tomography, and had normal perfusion results during stress and at rest. Follow-up was completed in all patients. During a follow-up of 6.5 +/- 1.9 years, 20 patients (14%) died, 10 (7%) of whom died due to cardiac causes, and 12 (8%) had a nonfatal myocardial infarction. Annual cardiac death rates were 0.5% during the first 3 years of follow-up and 1.3% in the subsequent 3 years. Independent predictors of cardiac death were male gender, rate-pressure product at rest, and rate-pressure product at peak stress. In conclusion, patients who have a history of CAD have a very low cardiac death rate during the 3 years after a normal finding on stress Tc-99m-tetrofosmin single-photon emission computed tomography. Repeated testing should be reconsidered 3 years after the initial evaluation and when a change in symptoms or clinical condition occurs.     

Non-invasive diagnosis of in stent stenosis by stress 99m technetium tetrofosmin myocardial perfusion imaging

Background The aim of this study was to assess the accuracy of stress 99m technetium tetrofosmin myocardial perfusion imaging for the diagnosis of in stent stenosis (ISS).Methods We studied 72 patients who underwent exercise or dobutamine stress 99m technetium tetrofosmin imaging, 0.9±0.5 years after percutaneous coronary interventions in which stents were deployed. Coronary angiography was performed within 3 months of the stress test. ISS was defined as ≥50% stenosis in a coronary segment with previous stenting. Significant coronary artery disease (CAD) was defined as ≥50% stenosis within or outside the stented coronary segment.Results The stent was deployed in 1 coronary artery in 52 patients, and in 2 coronary arteries in 20 patients (a total of 92 detected in 42 (58%) patients (51 stents). Reversible perfusion abnormalities were present in 34 of patients with ISS (sensitivity=81%, CI 70–94). Regional sensitivity for diagnosis of stenosis per stent was 76% (CI 65–88), specificity was 83% (CI 71–94) and accuracy was 79% (CI 69–85). Reversible perfusion abnormalities were detected in ≥2 vascular distributions in 15 of 22 patients with multi-vessel CAD and in 5 of 50 patients without (sensitivity for identifying multivessel CAD=68%, CI 50–89; specificity=90%, CI 82–98; and accuracy=83%, CI 75–90).Conclusion Stress 99m technetium tetrofosmin myocardial perfusion imaging is a useful non-invasive technique for the diagnosis of in stent stenosis and extent of CAD in patients with previous percutanenous coronary artery interventions.