317 research outputs found
Diagnostic value of T- and T-weighted 3-Tesla MRI for postmortem detection and age stage classification of myocardial infarction
The aims of this study are to retrospectively evaluate the diagnostic value of T- and T-weighted 3-T magnetic resonance imaging (MRI) for postmortem detection of myocardial infarction (MI) in terms of sensitivity and specificity and to compare the MRI appearance of the infarct area with age stages. Postmortem MRI examinations (nâ=â88) were retrospectively reviewed for the presence or absence of MI by two raters blinded to the autopsy results. The sensitivity and specificity were calculated using the autopsy results as the gold standard. A third rater, who was not blinded to the autopsy findings, reviewed all cases in which MI was detected at autopsy for MRI appearance (hypointensity, isointensity, hyperintensity) of the infarct area and the surrounding zone. Age stages (peracute, acute, subacute, chronic) were assigned based on the literature and compared with the age stages reported in the autopsy reports. The interrater reliability between the two raters was substantial (Îșâ=â0.78). Sensitivity was 52.94% (both raters). Specificity was 85.19% and 92.59%. In 34 decedents, autopsy identified an MI (peracute: nâ=â7, acute: nâ=â25, chronic: nâ=â2). Of 25 MI classified as acute at autopsy, MRI classified peracute in four cases and subacute in nine cases. In two cases, MRI suggested peracute MI, which was not detected at autopsy. MRI could help to classify the age stage and may indicate the area for sampling for further microscopic examination. However, the low sensitivity requires further additional MRI techniques to increase the diagnostic value
The âpost-weanlingâs conundrumâ: exploring the impact of infant and child feeding practices on early mortality in the Bronze Age burial cave of Moro de Alins, north-eastern Iberia, through stable isotope analysis
ProducciĂłn CientĂficaThe relationship between infant and child feeding practices and early mortality is difficult to address in past societies. Here, stable carbon (ÎŽ13C) and nitrogen (ÎŽ15N) isotope measurements of bulk bone and sequential dentine samples of deciduous second and/or permanent first molars of four younger children, one older child, one late adolescent, and two young adults (nâ=â8) from Moro de Alins cave, north-eastern Iberia, are used to explore the potential impact of early-life nutrition on mortality in the Bronze Age. Isotope results are compatible with generally short exclusive breastfeeding and standard weaning periods compared to other pre-modern populations. However, there are differences in exclusive breastfeeding mean ÎŽ13C values and in Î13C trophic shifts between exclusive breastfeeding and immediate post-weaning isotope values for those individuals who survived into adolescence and adulthood and those who did not. While the former seem to be consistent with trophic distances published for modern motherâinfant pairs, the latter are above most of them. This may suggest that individuals who consumed similar foods to their mothers or suffered from less physiological stress during or after weaning had greater chances of survival during early childhood and beyond. Post-weaning seems to have been a particularly stressful period of life, where a number of instances of patterns of opposing isotopic covariance compatible with catabolic changes, often preceding death among non-survivors, are detected. This outcome shows the key role of nutritional and/or physiological status in early-life morbidity and mortality among partially and especially fully weaned children from pre-antibiotic, pre-vaccination, and poor sanitation contexts and proposes that adult survival is rooted in early life experiences, in keeping with the developmental origins of health and disease.This work was supported and funded by the British Academy under the Newton International Fellowship NF170854European Unionâs Horizon 2020 research and innovation programme under the Marie SkĆodowska-Curie grant agreement No 790491Ministerio de Ciencia e InnovaciĂłn under the project (HAR2015-65620-P)PublicaciĂłn en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y LeĂłn (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEĂN, ActuaciĂłn:20007-CL - Apoyo Consorcio BUCL
Role of complement in in vitro and in vivo lung inflammatory reactions
Complement is one of the integral buttresses of the inflammatory response. In addition to host defense activities, proinflammatory properties of several complement components are described. This overview elucidates the role of complement in inflammatory reactions in vitro and in vivo, focusing on the complement activation products, C5a, and the membrane attack complex, C5bâ9. Using several approaches, the impact of these complement components in mechanisms relevant to neutrophil recruitment is emphasized. In addition, the participation of complement in endothelial superoxide generation and its essential requirement for full expression of lung injury is demonstrated, as are the involved intracellular signal transduction pathways. Understanding the mechanisms of complementâinduced proinflammatory effects may provide a basis for future therapeutic blockade of complement and/or its activation products. J. Leukoc. Biol. 64: 40â48; 1998.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142061/1/jlb0040.pd
Added value of ultra-short echo time and fast field echo using restricted echo-spacing MR imaging in the assessment of the osseous cervical spine
PURPOSE
To evaluate the added value of ultra-short echo time (UTE) and fast field echo resembling a CT using restricted echo-spacing (FRACTURE) MR sequences in the assessment of the osseous cervical spine using CT as reference.
MATERIALS AND METHODS
Twenty-seven subjects underwent postmortem CT and MRI within 48Â h. Datasets were anonymized and analyzed retrospectively by two radiologists. Morphological cervical spine alterations were rated on CT, UTE and FRACTURE images. Afterward, neural foraminal stenosis was graded on standard MR and again after viewing additional UTE/FRACTURE sequences. To evaluate interreader and intermodality reliability, intra-class correlation coefficients (ICC) and for stenosis grading Wilcoxon-matched-pairs testing with multiple comparison correction were calculated.
RESULTS
Moderate interreader reliability (ICCâ=â0.48-0.71) was observed concerning morphological findings on all modalities. Intermodality reliability was good between modalities regarding degenerative vertebral and joint alterations (ICCâ=â0.69-0.91). Compared to CT neural stenosis grades were more often considered as nonsignificant on all analyzed MR sequences. Neural stenosis grading scores differed also significantly between specific bone imaging sequences, UTE and FRACTURE, to standard MR sequences. However, no significant difference was observed between UTE and FRACTURE sequences.
CONCLUSION
Compared to CT as reference, UTE or FRACTURE sequence added to standard MR sequences can deliver comparable information on osseous cervical spine status. Both led to changes in clinically significant stenosis gradings when added to standard MR, mainly reducing the severity of neural foramina stenosis
Assessing the reliability of microbial bioerosion features in burnt bones: a novel approach using feature-labelling in histotaphonomical analysis
Objectives
Recent histotaphonomic studies have focused on the presence of features thought to be caused either by bacteria (microscopic focal destruction/MFD and cyanobacterial tunnelling) or fungal (Wedl tunnelling types 1 and 2) attack on unburnt bone. Identifying these characteristics on burnt bones could indicate the state of decomposition before burning, with important repercussions for both archaeological and forensic contexts.
Materials and Methods
Fleshed pig (Sus scrofa, N = 25) tibiae were left exposed on a field, then collected at 14-, 34-, 91-, 180-, 365-day intervals before being burnt in an outdoor fire (â€750 °C). Fresh (fleshed) legs (N = 10) acted as unburnt and burnt controls. Thin sections were examined using transmitted light microscopy and backscattered scanning electron microscopy. Diagenetic traits were quantitatively and systematically assessed by a novel data labelling application developed for this study.
Results
Features meeting the published characteristics of microbial bioerosion (âWedl tunnellingâ, âlamellateâ and âbudded MFDâ) were significantly correlated with time since deposition on the unburnt bones. Only budded MFD increased significantly over time in the burnt groups. However, the presence features meeting the published characteristics of Wedl 2 tunnelling were present on the fresh burnt bones, indicating that they are an artefact.
Discussion
The presence of many features seemingly indistinguishable from those caused by bioerosion on the freshly burnt control bones suggests that burning is not only able to conceal features thought to be the result of bioerosion but can produce them as well. Thus, such features are not a reliable indication of bioerosion. Budded MFD may be a viable indicator but more research is required
Regulatory effects of interleukinâ11 during acute lung inflammatory injury
The role of interleukinâ11 (ILâ11) was evaluated in the IgG immune complex model of acute lung injury in rats. ILâ11 mRNA and protein were both upâregulated during the course of this inflammatory response. Exogenously administered ILâ11 substantially reduced, in a doseâdependent manner, the intrapulmonary accumulation of neutrophils and the lung vascular leak of albumin. These in vivo antiâinflammatory effects of ILâ11 were associated with reduced NFâÎșB activation in lung, reduced levels of tumor necrosis factor α (TNFâα) in bronchoalveolar lavage (BAL) fluids, and diminished upâregulation of lung vascular ICAMâ1. It is interesting that ILâ11 did not affect BAL fluid content of the CXC chemokines, macrophage inflammatory proteinâ2 (MIPâ2) and cytokineâinducible neutrophil chemoattractant (CINC); the presence of ILâ11 did not affect these chemokines. However, BAL content of C5a was reduced by ILâ11. These data indicate that ILâ11 is a regulatory cytokine in the lung and that, like other members of this family, its antiâinflammatory properties appear to be linked to its suppression of NFâÎșB activation, diminished production of TNFâα, and reduced upâregulation of lung vascular ICAMâ1. J. Leukoc. Biol. 66: 151â157; 1999.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141937/1/jlb0151.pd
Mediators of Microvascular Injury in Dermal Burn Wounds
In previous studies we have demonstrated that second-degree thermal injury of skin in rats leads to secondary effects, such as systemic complement activation, C5a-mediated activation of blood neutrophils, their adhesion-molecule-guided accumulation in lung capillaries and the development of acute pulmonary injury, largely caused by neutrophil-derived toxic oxygen metabolites. In the dermal burn wound, however, pathophysiologic events are less well understood. The injury is fully developed at four hours post-burn. To further elucidate the pathogenesis of the âlate phaseâ dermal vascular damage, rats were depleted of neutrophils or complement by pretreatment with rabbit antibody against rat neutrophils or with cobra venom factor, respectively. In other experiments, rats were treated with blocking antibodies to IL-6, IL-1, and TNFα immediately following thermal burning or were pretreated with hydroxyl radical scavengers (dimethyl sulfoxide, dimethyl thiourea). Extravasation of 125 I-labeled bovine serum albumin into the burned skin was studied, as well as, skin myeloperoxidase levels. The studies revealed that, like in secondary lung injury, neutrophils and toxic oxygen metabolites, are required for full development of microvascular injury. In contrast, however, development of dermal vascular damage in thermally injured rats was not affected by complement depletion. Our data suggest that the development of microvascular injury in the dermal burn wound is complement-independent, involves the pro-inflammatory cytokines IL-1, TNFα and IL-6, and may result from reactive oxygen metabolites generated by neutrophils accumulating in the burn wound.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44523/1/10753_2004_Article_415307.pd
Conformal TiO aerogel-like films by plasma deposition: from omniphobic antireflective coatings to perovskite solar cells photoelectrodes
The ability to control porosity in oxide thin films is one of the key factors
that determine their properties. Despite the abundance of dry processes for the
synthesis of oxide porous layers, the high porosity range is typically achieved
by spin-coating-based wet chemical methods. Besides, special techniques such as
supercritical drying are required to replace the pore liquid with air while
maintaining the porous network. In this study, we propose a new method for the
fabrication of ultra-porous titanium dioxide thin films at room or mild
temperatures (T lower or equal to 120 degrees Celsius) by the sequential
process involving plasma deposition and etching. These films are conformal to
the substrate topography even for high-aspect-ratio substrates and show
percolated porosity values above 85 percent that are comparable to advanced
aerogels. The films deposited at room temperature are amorphous. However, they
become partly crystalline at slightly higher temperatures presenting a
distribution of anatase clusters embedded in the sponge-like structure.
Surprisingly, the porous structure remains after annealing the films at 450
degrees Celsius in air, which increases the fraction of the embedded anatase
nanocrystals. The films are antireflective, omniphobic, and photoactive
becoming super-hydrophilic subjected to UV light irradiation The supported
percolated nanoporous structure can be used as an electron-conducting electrode
in perovskite solar cells. The properties of the cells depend on the aerogel
film thickness reaching efficiencies close to those of commercial mesoporous
anatase electrodes. This generic solvent-free synthesis is scalable and is
applicable to ultra-high porous conformal oxides of different compositions with
potential applications in photonics, optoelectronics, energy storage, and
controlled wetting.Comment: 31 pages, 10 Figs. plus Supporting Information 7 pags, 6 figs. Full
Pape
Silicon detector for a Compton Camera in Nuclear Medical Imaging
Electronically collimated gamma ca\-me\-ras based on Com\-pton scattering in silicon pad sensors may improve imaging in nuclear medicine and bio-medical research. The work described here concentrates on the silicon pad detector developed for a prototype Compton camera. The silicon pad sensors are read out using low noise VLSI CMOS chips and novel fast triggering chips. Depending on the application a light weight and dense packaging of sensors and its readout electronics on a hybrid is required. We describe the silicon pad sensor and their readout with the newly designed hybrid. %The silicon detector of a Compton camera %may contain up to ~analogue channels requiring %a fast and low cost data acquisition system. We also describe a modular and low-cost data acquisition system (CCDAQ) based on a digital signal processor which is interfaced to the EPP port of personal computers. Using the CCDAQ and the hybrids energy spectra of gamma-ray photons from technetium (Tc) and americium (Am) were acquired with an energy resolution of 2.45~keV FWHM for the 140.5~keV photo-absorption line of Tc. For all pads the discrimination threshold in the trigger chip was between (15 and 25)~keV
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