Advances in ultrasonography of urinary tract obstruction

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42393/1/261-23-1-3_23n1p3.pd

The Effect of Poststenotic Vessel Wall Compliance upon the Pulsus Tardus Phenomenon

Recent studies have investigated the detection of significant arterial stenoses through identification of the "pulsus tardus" phenomenon in Doppler waveforms obtained distal to the stenosis. The etiology of this phenomenon, however, has not yet been determined. Using an in vitro model based upon an electrical circuit analogy, the authors had as their objective to determine whether the compliance of the vessel wall immediately distal to a stenosis, in conjunction with the stenosis, is the cause of pulsus tardus. For a constant stenosis, it was found that the degree of pulsus tardus, as quantitated by the acceleration index, increased as the compliance of the poststenotic segment increased. It is concluded that pulsus tardus distal to an arterial stenosis is likely due to the compliance of the normally distensible artery, in conjunction with the stenosis. Pathological conditions that alter the compliance of the poststenotic segment may affect the degree of pulsus tardus, perhaps limiting its usefulness for upstream stenosis detection.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68136/2/10.1177_000331979404500703.pd

Dilated renal collecting systems:Differentiating obstructive from nonobstructive dilation using duplex doppler ultrasound

Two patients with ileal loop urinary diversions, studied with real-time and Doppler sonogphy ("duplex sonography") of the kidneys, were shown to have dilated intrarenal collecting Resistive index measurements calculated from the Doppler signal correctly identified obstructive dilatation in 1 case and nonobstructive dilatation in the other.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29467/1/0000553.pd

The prediction of radiationâ induced liver dysfunction using a local dose and regional venous perfusion model

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134805/1/mp1081.pd

Technique and diagnostic utility of saline infusion sonohysterography

The introduction of saline infusion sonohysterography has significantly improved sonographic diagnosis of various endometrial pathologies. This procedure entails instillation of warm saline into the uterine cavity transcervically to provide enhanced visualization of the endometrium during transvaginal ultrasound examination. This article reviews the sonohysterography technique and current utility, as well as the spectrum of imaging features of various endometrial pathologies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135202/1/ijgo5.pd

Computed tomographic enterography adds information to clinical management in small bowel Crohn's disease

Background: CT enterography yields striking findings in the bowel wall in Crohn's disease. These images may help to evaluate whether small bowel narrowing results from active disease requiring anti-inflammatory therapy. However, the clinical relevance of these images is unknown. It is also not known if these radiologic findings correlate with objective biomarkers of inflammation. Methods: In a blinded and independent evaluation, IBD subspecialty gastroenterologists reviewed clinical data, and CT radiologists reviewed CT enterography scans of 67 consecutive patients with Crohn's disease and suspicion of either small bowel inflammation or stricture. Comparisons were made between (1) clinical and radiologic assessments of inflammation and stricture, (2) clinical assessments before and after computed tomographic enterography (CTE) reports were revealed, and (3) radiologic findings and objective biomarkers of inflammation. Results: (1) Individual CTE findings correlated poorly (Spearman's rho < 0.30) with clinical assessment; (2) clinicians did not suspect 16% of radiologic strictures, and more than half the cases of clinically suspected strictures did not have them on CTE; (3) CTE data changed clinicians' perceptions of the likelihood of steroid benefit in 41 of 67 cases; (4) specific CTE findings correlated with CRP, and a distinct set of CTE findings correlated with ESR in the subset of patients who had these biomarkers measured. Conclusions: CTE seems to add unique information to clinical assessment, both in detecting additional strictures and in changing clinicians' perceptions of the likelihood of steroids benefiting patients. The biomarker correlations suggest that CTE is measuring real biologic phenomena that correlate with inflammation, providing information distinct from that in a standard clinical assessment. (Inflamm Bowel Dis 2006)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55965/1/20013_ftp.pd

Adaptive Value of Phenological Traits in Stressful Environments: Predictions Based on Seed Production and Laboratory Natural Selection

Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition), using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS), we assessed the strength and nature (directional, disruptive and stabilizing) of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously

European aerosol phenomenology - 8 : Harmonised source apportionment of organic aerosol using 22 Year-long ACSM/AMS datasets

Organic aerosol (OA) is a key component of total submicron particulate matter (PM1), and comprehensive knowledge of OA sources across Europe is crucial to mitigate PM1 levels. Europe has a well-established air quality research infrastructure from which yearlong datasets using 21 aerosol chemical speciation monitors (ACSMs) and 1 aerosol mass spectrometer (AMS) were gathered during 2013-2019. It includes 9 non-urban and 13 urban sites. This study developed a state-of-the-art source apportionment protocol to analyse long-term OA mass spectrum data by applying the most advanced source apportionment strategies (i.e., rolling PMF, ME-2, and bootstrap). This harmonised protocol was followed strictly for all 22 datasets, making the source apportionment results more comparable. In addition, it enables quantification of the most common OA components such as hydrocarbon-like OA (HOA), biomass burning OA (BBOA), cooking-like OA (COA), more oxidised-oxygenated OA (MO-OOA), and less oxidised-oxygenated OA (LO-OOA). Other components such as coal combustion OA (CCOA), solid fuel OA (SFOA: mainly mixture of coal and peat combustion), cigarette smoke OA (CSOA), sea salt (mostly inorganic but part of the OA mass spectrum), coffee OA, and ship industry OA could also be separated at a few specific sites. Oxygenated OA (OOA) components make up most of the submicron OA mass (average = 71.1%, range from 43.7 to 100%). Solid fuel combustion-related OA components (i.e., BBOA, CCOA, and SFOA) are still considerable with in total 16.0% yearly contribution to the OA, yet mainly during winter months (21.4%). Overall, this comprehensive protocol works effectively across all sites governed by different sources and generates robust and consistent source apportionment results. Our work presents a comprehensive overview of OA sources in Europe with a unique combination of high time resolution (30-240 min) and long-term data coverage (9-36 months), providing essential information to improve/validate air quality, health impact, and climate models.Peer reviewe

A Wide Extent of Inter-Strain Diversity in Virulent and Vaccine Strains of Alphaherpesviruses

Alphaherpesviruses are widespread in the human population, and include herpes simplex virus 1 (HSV-1) and 2, and varicella zoster virus (VZV). These viral pathogens cause epithelial lesions, and then infect the nervous system to cause lifelong latency, reactivation, and spread. A related veterinary herpesvirus, pseudorabies (PRV), causes similar disease in livestock that result in significant economic losses. Vaccines developed for VZV and PRV serve as useful models for the development of an HSV-1 vaccine. We present full genome sequence comparisons of the PRV vaccine strain Bartha, and two virulent PRV isolates, Kaplan and Becker. These genome sequences were determined by high-throughput sequencing and assembly, and present new insights into the attenuation of a mammalian alphaherpesvirus vaccine strain. We find many previously unknown coding differences between PRV Bartha and the virulent strains, including changes to the fusion proteins gH and gB, and over forty other viral proteins. Inter-strain variation in PRV protein sequences is much closer to levels previously observed for HSV-1 than for the highly stable VZV proteome. Almost 20% of the PRV genome contains tandem short sequence repeats (SSRs), a class of nucleic acids motifs whose length-variation has been associated with changes in DNA binding site efficiency, transcriptional regulation, and protein interactions. We find SSRs throughout the herpesvirus family, and provide the first global characterization of SSRs in viruses, both within and between strains. We find SSR length variation between different isolates of PRV and HSV-1, which may provide a new mechanism for phenotypic variation between strains. Finally, we detected a small number of polymorphic bases within each plaque-purified PRV strain, and we characterize the effect of passage and plaque-purification on these polymorphisms. These data add to growing evidence that even plaque-purified stocks of stable DNA viruses exhibit limited sequence heterogeneity, which likely seeds future strain evolution