Correlation of adrenomedullin gene expression in peripheral blood leukocytes with severity of ischemic stroke

Human adrenomedullin (ADM), a 52-amino acid peptide, belongs to the calcitonin/calcitonin gene-related peptide (CGRP)/amylin peptide family. ADM acts as a multifunctional regulatory peptide and is upregulated in response to hypoxia. Previous microarray studies have found increased ADM gene (ADM) expression in peripheral blood cells of patients with stroke, however, it is unknown if an increased ADM level is correlated with severity of human ischemic stroke. This study investigated ADM expression in peripheral blood leukocytes (PBL) of healthy controls and subjects at day 1, week 1 and week 3 postacute ischemic stroke using rtPCR methodology. We found that ADM expression was significantly upregulated on the first day of stroke compared to the healthy subjects and the disease controls; the levels remained elevated for up to week 3. Further, ADM expression at day 1 was correlated with stroke severity measured by the National Institute of Healthy Stroke Scale (NIHSS), the modified Barthel Index (mBI) and the modified Rankin Scale (mRS). This could indicate that ADM expression level is related to the severity of tissue damage. We suggest that increased ADM expression in PBL after acute ischemic stroke is most likely to indicate that these cells have been subjected to hypoxia and that the magnitude of expression is likely to be related to the volume of hypoxic tissue. Hypoxia can affect lymphocytes function and could affect the immune response to stroke. The correlation of ADM expression level with the measures of stroke severity implicates ADM - a potential blood bio-marker in studies of ischemic stroke

Genome evolution and plasticity of <em>Serratia marcescens</em>:an important multidrug resistant nosocomial pathogen

Serratia marcescens is an important nosocomial pathogen that can cause an array of infections, most notably of the urinary tract and bloodstream. Naturally, it is found in many environmental niches, and is capable of infecting plants and animals. The emergence and spread of multidrug-resistant strains producing extended-spectrum or metallo beta-lactamases now pose a threat to public health worldwide. Here we report the complete genome sequences of two carefully selected S. marcescens strains, a multidrug-resistant clinical isolate (strain SM39) and an insect isolate (strain Db11). Our comparative analyses reveal the core genome of S. marcescens and define the potential metabolic capacity, virulence, and multidrug resistance of this species. We show a remarkable intraspecies genetic diversity, both at the sequence level and with regards genome flexibility, which may reflect the diversity of niches inhabited by members of this species. A broader analysis with other Serratia species identifies a set of approximately 3,000 genes that characterize the genus. Within this apparent genetic diversity, we identified many genes implicated in the high virulence potential and antibiotic resistance of SM39, including the metallo beta-lactamase and multiple other drug resistance determinants carried on plasmid pSMC1. We further show that pSMC1 is most closely related to plasmids circulating in Pseudomonas species. Our data will provide a valuable basis for future studies on S. marcescens and new insights into the genetic mechanisms that underlie the emergence of pathogens highly resistant to multiple antimicrobial agents

Left atrial appendage emptying fraction assessed by a feature-tracking echocardiographic method is a determinant of thrombus in patients with nonvalvular atrial fibrillation

SummaryBackgroundLeft atrial appendage (LAA) thrombus increases the risk of thromboembolism in atrial fibrillation (AF), and LAA contractile function like emptying fraction (EF) should have physiological importance in thrombus formation. The aim of this study was to validate a velocity vector imaging (VVI) method for quantification of the LAA function and to elucidate echocardiographic parameters that are related to the presence of LAA thrombus in patients with nonvalvular AF.MethodsWe measured left atrial (LA) dimension and LAEF by VVI using transthoracic echocardiography, and LAA emptying velocity, spontaneous echo contrast (SEC), and LAAEF by VVI using transesophageal echocardiography (TEE) in 142 consecutive patients with nonvalvular AF. The patients were divided into two groups according to the presence (n=38) or absence (n=104) of LAA thrombus.ResultsThere was a good correlation between the VVI method and manual-tracing method for LAAEF and LAEF of patients with AF (r=0.97, r=0.96, respectively, p<0.001). LAAEF in AF with thrombus was significantly reduced compared with AF without thrombus (16.9±3.1% and 29.0±9.7%, p<0.001). In multivariate logistic regression analysis, LAAEF, SEC, and prior stroke were independent determinants of LAA thrombus. Using 20% of LAAEF as a cutoff value, the sensitivity was 92% and specificity was 88% for LAA thrombus.ConclusionThe VVI method was reliable in the measurement of LAAEF and LAEF compared with the manual-tracing method. LAAEF assessed by the VVI method using TEE was related to the presence of LAA thrombus

Output characteristics of piezoelectric lead zirconate titanate detector using high-energy heavy-ion beam

A radiation detector fabricated using piezoelectric lead zirconate titanate (PZT) has been studied by irradiating it with a 400 MeV/n xenon (Xe) beam. The beam diameter was controlled to change the irradiation conditions. It was found that the magnitude of the output observed from the PZT detector may be related to the number of Xe ions per unit area per unit time within the limits of the experimental conditions

Acoustic signal production in ethanol by energetic xenon ions

Acoustic signals produced by irradiating ethanol with 400 MeV/n Xe ions were experimentally studied. The signals were detected by an array of piezoelectric PZT elements. They were categorized into two types: one was a primary product of the incident fast ions; the other was a secondary product resulting from an energy release to ethanol just before the ions stopped and subsequently diffused in ethanol. A possible mechanism of the secondary signal is discussed in association with the Bragg peak formation

Variation in resonant frequency of piezoelectric lead–zirconate–titanate element undergoing high-level radiation

A piezoelectric lead–zirconate–titanate (PZT) element was exposed to a 400MeV/n xenon beam and the radiation effect on the element was studied as a variation of resonant and antiresonant frequencies by the resonance method. A possible effect of heating the element on the resonant frequency was avoided by using data obtained while the temperature of the element was kept constant. Consequently, the variation of the resonant frequency was empirically represented by a simple function of the amount of accumulated energy in the element. We therefore discuss the piezoelectric PZT element as a potential detector for high-level radiation. We point out that a piezoelectric equation including the heat term is required to explain the experimental results