154 research outputs found
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
Clinical features and long-term outcome of nephrotic syndrome associated with heterozygous NPHS1 and NPHS2 mutations.
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 dell’inquinamento da plastiche sui foraminiferi bentonici
Le plastiche sono divenuti contaminanti ubiquitari negli ecosistemi marini, d’acqua dolce e terrestri
che producono rilevanti impatti sulle specie che in essi vivono. Dal 1950 ad oggi sono stati accumulati
nell’ambiente 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
dell’ecosistema e nei cicli biogeochimici. La loro sensibilità 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 l’effetto delle plastiche negli oceani e negli organismi marini, abbiamo valutato
l’incorporazione di (bio)polimeri e microplastiche in foraminiferi bentonici utilizzando tecniche di spettromicroscopia
ad infrarossi in trasformata di Fourier (ÎĽFTIR).
In questo studio, abbiamo raccolto ed analizzato spettri ed immagini ÎĽFTIR 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 l’incorporazione 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) l’incorporazione 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 dell’inquinamento da microplastiche sia a livello cellulare che di biomineralizzazione confermando
l’ingresso delle microplastiche e DEHP nei cicli biogeochimici.
Questa indagine ha inoltre dimostrato che la microscopia FTIR è uno strumento efficace per studiare,
senza l’utilizzo di marcatori specifici, l’interazione 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 5 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 5 years of age. Some children present with extrarenal symptoms: retinitis pigmentosa (Senior-Løken 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
Genetic and Clinical Predictors of Age of ESKD in Individuals With Autosomal Dominant Tubulointerstitial Kidney Disease Due to UMOD Mutations
Changes of anti-glucosidase content and some other characteristics in mulberry juice during fermentation with Leuconostoc mesenteroides
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