171 research outputs found
Single-Center Experience with Simultaneous Mural Aortic Thrombosis and Peripheral Obstructive Disease in Pre-COVID-19 and COVID-19 Era
Background: Mural aortic thrombosis associated with chronic peripheral obstruction of the lower limbs is an unusual event. Repeated embolism of instability aortic mural thrombosis caused acute limb ischemia (Rutherford 2 classification) in patients with peripheral arterial disease (PAD). We report a single-center experience for patients with transmural aortic thrombosis and peripheral artery disease. Methods: We retrospectively analyzed data of 54 patients with aortic mural thrombus disease with PAD presentation, treated at our center between 2013 and 2022. Results: Thirty patients (six with proven SARS-CoV-2 infection) underwent hybrid or staged treatment for an aortic lesion and for lower limb ischemia, by the placement of an endovascular aortic stent graft and a femoro-distal or a popliteal-distal bypass graft. The remaining 24 cases were only subjected to an intravascular treatment of the thoracic or abdominal aorta. Transient renal failure occurred in three patients. No embolic events were detected during the procedures. Aortic-related mortality was reported in just one patient who died from multiple organ failure. There was an embolic stroke in one patient with proven SARS-CoV-2 infection, three major amputations in patients with proven SARS-CoV-2 infection and no aortic-related mortality. Conclusions: Stent coverage of complex aortic lesions, alone or in association with a distal bypass graft, supports this approach in a variety of settings. The COVID-19 pandemic caused an increased mortality and amputation rate
The TU Wien Turbulent Water Channel: Flow control loop and three-dimensional reconstruction of anisotropic particle dynamics
A horizontal water channel facility was built to study particle dynamics in a turbulent flow. The channel is sufficiently long to produce fully developed turbulence at the test section, and the width-to-height ratio is sufficiently large to avoid the sidewall effect for a large proportion of the cross-section. The system was designed to study the dynamics of complex-shaped particles in wall-bounded turbulence, the characteristics of which can be finely controlled. A maximum bulk velocity of up to 0.8 m sâ1 can be achieved, corresponding to a bulk Reynolds number of up to 7 Ă 104 (shear Reynolds number â 1580 ), and flow parameters can be controlled within ±0.1%. The transparent channel design and aluminum structures allow easy optical access, which enables multiple laser and camera arrangements. With the current optical setup, a measurement volume of up to 54 Ă 14 Ă 54 mm3 can be imaged and reconstructed with six cameras from the top, bottom, and sides of the channel. Finally, the in-house developed reconstruction and tracking procedure allows us to measure the full motion of complex objects (i.e., shape reconstruction, translational, and rotational motions), and in this instance, it is applied to the case of microscopic, non-isotropic polyamide fibers
Response of Foraminifera to Anthropogenic Nicotine Pollution of Cigarette Butts: An Experimental Approach
The most often dispersed environmental pollutants that are released both directly and indirectly into the environment that may eventually reach aquatic ecosystems and contaminate aquatic biomes are cigarette butts (CBs). Toxicants such as nicotine, dangerous metals, total particulate matter, and recognized carcinogens can be introduced and transported via CBs into aquatic ecosystems. The examination of the effects of synthetic nicotine on three different species of cultured benthic foraminifera was the focus of this study. Three foraminiferal species from three distinct biomineralization pathways were specifically examined for viability and cellular ultrastructure, including the calcareous perforate Rosalina globularis, the calcareous imperforate Quinqueloculina spp., and the agglutinated Textularia agglutinans. The survival rate, cellular stress, and decalcification were used to assess the toxicological effects of synthetic nicotine. We were able to analyze the reaction of major macromolecules and calcium carbonate to this pollutant using FTIR (Fourier Transform Infrared) spectroscopy. High Performance Liquid Chromatography (HPLC) study was performed to increase our understanding of nicotine bioavailability in the medium culture. Different acute experiments were performed at different dates, and all indicated that synthetic nicotine is acutely hazardous to all three cultured foraminiferal taxa at lethal and sublethal concentrations. Each species responded differently depending on the type of shell biomineralization. Synthetic nicotine enhances shell decalcification and affects the composition of cytoplasmic macromolecules such as lipids and proteins, according to the FTIR spectroscopy investigations. The lipid content rose at lethal concentrations, possibly due to the creation of vesicles. The proteins signal evidences general cellular dyshomeostasis. The integration among the acute toxicity assay, synchrotron, and chemical HPLC analyses provided a valuable approach for the assessment of nicotine as a biomarker of exposure to the toxicants associated with smoking and the impact of this emerging and hazardous material on calcifying marine species
Biomarkers in post-reperfusion syndrome after acute lower limb ischaemia
Ischaemia reperfusion (I/R) injury refers to tissue damage caused when blood supply
returns to the tissue after a period of ischaemia. Matrix metalloproteinases (MMPs),
neutrophil gelatinase-associated lipocalin (NGAL) and cytokines are biomarkers
involved in several vascular complications. The aim of this study was to evaluate the
role of MMPs, NGAL and inflammatory cytokines in I/R syndrome. We conducted an
open label, multicentric, parallel group study, between January 2010 and December
2013. Patients with acute limb ischaemia were enrolled in this study and were divided
into two groups: (i) those subjected to fasciotomy and (ii) those not subjected to fasciotomy,
according to the onset of compartment syndrome. Plasma and tissue values
of MMPs and NGAL as well as plasma cytokines were evaluated. MMPs, NGAL and
cytokine levels were higher in patients with compartment syndrome. Biomarkers evaluated
in this study may be used in the future as predictors of I/R injury severity and its
possible evolution towards post-reperfusion syndrome
Urinary secretion and extracellular aggregation of mutant uromodulin isoforms
Uromodulin is exclusively expressed in the thick ascending limb and is the most abundant protein secreted in urine where it is found in high-molecular-weight polymers. Its biological functions are still elusive, but it is thought to play a protective role against urinary tract infection, calcium oxalate crystal formation, and regulation of water and salt balance in the thick ascending limb. Mutations in uromodulin are responsible for autosomal-dominant kidney diseases characterized by defective urine concentrating ability, hyperuricemia, gout, tubulointerstitial fibrosis, renal cysts, and chronic kidney disease. Previous in vitro studies found retention in the endoplasmic reticulum as a common feature of all uromodulin mutant isoforms. Both in vitro and in vivo we found that mutant isoforms partially escaped retention in the endoplasmic reticulum and reached the plasma membrane where they formed large extracellular aggregates that have a dominant-negative effect on coexpressed wild-type protein. Notably, mutant uromodulin excretion was detected in patients carrying uromodulin mutations. Thus, our results suggest that mutant uromodulin exerts a gain-of-function effect that can be exerted by both intra- and extracellular forms of the protein
Urinary secretion and extracellular aggregation of mutant uromodulin isoforms.
Uromodulin is exclusively expressed in the thick ascending limb and is the most abundant protein secreted in urine where it is found in high-molecular-weight polymers. Its biological functions are still elusive, but it is thought to play a protective role against urinary tract infection, calcium oxalate crystal formation, and regulation of water and salt balance in the thick ascending limb. Mutations in uromodulin are responsible for autosomal-dominant kidney diseases characterized by defective urine concentrating ability, hyperuricemia, gout, tubulointerstitial fibrosis, renal cysts, and chronic kidney disease. Previous in vitro studies found retention in the endoplasmic reticulum as a common feature of all uromodulin mutant isoforms. Both in vitro and in vivo we found that mutant isoforms partially escaped retention in the endoplasmic reticulum and reached the plasma membrane where they formed large extracellular aggregates that have a dominant-negative effect on coexpressed wild-type protein. Notably, mutant uromodulin excretion was detected in patients carrying uromodulin mutations. Thus, our results suggest that mutant uromodulin exerts a gain-of-function effect that can be exerted by both intra- and extracellular forms of the protein
Effetti dellâinquinamento da plastiche sui foraminiferi bentonici
Le plastiche sono divenuti contaminanti ubiquitari negli ecosistemi marini, dâacqua dolce e terrestri
che producono rilevanti impatti sulle specie che in essi vivono. Dal 1950 ad oggi sono stati accumulati
nellâambiente circa 5 miliardi di tonnellate di plastica (Geyer et al., 2017). I meccanismi di interazione tra
microplastiche e biosfera nonché gli effetti biochimici delle molecole sintetiche, specialmente sugli organismi
eucariotici unicellulari marini, sono scarsamente studiati. In particolare, i foraminiferi bentonici costituiscono
una componente fondamentale delle comunitĂ marine e svolgono un ruolo chiave nel funzionamento
dellâecosistema e nei cicli biogeochimici. La loro sensibilitĂ e la rapida risposta allo stress ambientale li
rendono efficienti indicatori dei cambiamenti climatici e ambientali attuali e del passato (Schönfeld et al.,
2012).Per comprendere meglio lâeffetto delle plastiche negli oceani e negli organismi marini, abbiamo valutato
lâincorporazione di (bio)polimeri e microplastiche in foraminiferi bentonici utilizzando tecniche di spettromicroscopia
ad infrarossi in trasformata di Fourier (ÎŒFTIR).
In questo studio, abbiamo raccolto ed analizzato spettri ed immagini ÎŒFTIR dauna selezione di specie
di foraminiferi bentonici: Rosalina globularis cresciuta in colture inquinate con la plastica e Cibicidoides
lobatulus, Rosalina bradyi e Textularia bocki raccolti su un frammento di plastica trovato sepolto in un
sedimento del fondale del Mar Mediterraneo. In particolare, i foraminiferi provenienti dalle colture sono stati
intossicati con molecola di di-2-etilesilftalato (DEHP) allo scopo di valutarne lâincorporazione nel citoplasma.
Questo studio ha permesso di documentare: (1) la presenza di microplastiche nel citoplasma e nel guscio
agglutinante di T. bocki; (2) segnali di stress ossidativo e di aggregazione proteica nella componente cellulare di
C. lobatulus, R. bradyi e T. bocki, ancorati alla busta di plastica; (3) lâincorporazione del DEHP nel citoplasma
di R. globularis.
Questo studio ha confermato il ruolo chiave svolto dai foraminiferi bentonici come proxy per la valutazione
degli effetti dellâinquinamento da microplastiche sia a livello cellulare che di biomineralizzazione confermando
lâingresso delle microplastiche e DEHP nei cicli biogeochimici.
Questa indagine ha inoltre dimostrato che la microscopia FTIR Ăš uno strumento efficace per studiare,
senza lâutilizzo di marcatori specifici, lâinterazione su scala molecolare tra plastica, citoplasma e guscio dei
foraminiferi
The Temperley-Lieb algebra and its generalizations in the Potts and XXZ models
We discuss generalizations of the Temperley-Lieb algebra in the Potts and XXZ
models. These can be used to describe the addition of different types of
integrable boundary terms.
We use the Temperley-Lieb algebra and its one-boundary, two-boundary, and
periodic extensions to classify different integrable boundary terms in the 2,
3, and 4-state Potts models. The representations always lie at critical points
where the algebras becomes non-semisimple and possess indecomposable
representations. In the one-boundary case we show how to use representation
theory to extract the Potts spectrum from an XXZ model with particular boundary
terms and hence obtain the finite size scaling of the Potts models. In the
two-boundary case we find that the Potts spectrum can be obtained by combining
several XXZ models with different boundary terms. As in the Temperley-Lieb case
there is a direct correspondence between representations of the lattice algebra
and those in the continuum conformal field theory.Comment: 49 page
Nephronophthisis
Nephronophthisis (NPH) is an autosomal recessive disease characterized by a chronic tubulointerstitial nephritis that progress to terminal renal failure during the second decade (juvenile form) or before the age of 5Â years (infantile form). In the juvenile form, a urine concentration defect starts during the first decade, and a progressive deterioration of renal function is observed in the following years. Kidney size may be normal, but loss of corticomedullary differentiation is often observed, and cysts occur usually after patients have progressed to end-stage renal failure. Histologic lesions are characterized by tubular basement membrane anomalies, tubular atrophy, and interstitial fibrosis. The infantile form is characterized by cortical microcysts and progression to end-stage renal failure before 5Â years of age. Some children present with extrarenal symptoms: retinitis pigmentosa (Senior-LĂžken syndrome), mental retardation, cerebellar ataxia, bone anomalies, or liver fibrosis. Positional cloning and candidate gene approaches led to the identification of eight causative genes (NPHP1, 3, 4, 5, 6, 7, 8, and 9) responsible for the juvenile NPH and one gene NPHP2 for the infantile form. NPH and associated disorders are considered as ciliopathies, as all NPHP gene products are expressed in the primary cilia, similarly to the polycystic kidney disease (PKD) proteins
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