1,610 research outputs found
Erythrocytes as carriers of oxalate decarboxylase from Bacillus subtilis: an innovative approach for the treatment of hyperoxaluria
No full textHyperoxaluria is a pathologic condition due to genetic and non-genetic causes that leads to the deposition of calcium oxalate (CaOx) crystals at first in the urinary system and, in the most severe forms, in the whole body. The disease can be due to either an increased endogenous oxalate production (primary hyperoxaluria or PH) or an increased intestinal oxalate absorption (secondary hyperoxaluria or SH). Three forms of PH are known. They are inherited disorders caused by the deficit of enzymes involved in liver glyoxylate metabolism. The most common and most severe form is PH1. Two curative therapies are currently available for the treatment of PH1: pyridoxine administration (PN) and liver transplantation. However, The first is only effective in 10-30% of the patients, while the second is a very invasive and risky procedure. Thus, the development of new therapeutic strategies represents an urgent need. In this regard, we hypothesized that a possible approach could be the use of an oxalate-degrading enzyme, which would reduce plasma oxalate concentration thus counteracting the formation of CaOx. Oxalate Decarboxylase (OxDC) from B. subtilis is an hexameric Mn-dependent enzyme belonging to the bicupin family that catalyses the cleavage of the oxalate C-C bond to give carbon dioxide and formate. A mutated form of the enzyme, called OxDC-DSSN, shows a reduced decarboxylase specific activity, but is endowed with the ability to catalyse an oxalate oxidation reaction. It should be underlined that OxDC displays an optimum pH around 4 and a deep characterization of the enzyme at neutral pH is still lacking. Based on these considerations, the aim of my PhD was the study of the biochemical features of OxDC at neutral pH and their possible improvement by protein engineering techniques. Moreover, since the direct administration of a non-human protein would elicit a remarkable immune reaction, we thought to encapsulate OxDC in red blood cells (RBCs) and use loaded RBCs as oxalate-degrading bioreactors. The data obtained indicate that: 1) OxDC and OxDC-DSSN (i) display optimal activity at pH 4.2 but retain a detectable residual activity at pH 7.2, the intracellular pH of RBCs, (ii) do not undergo major structural changes at neutral pH, (iii) are able to detoxify oxalate endogenously produced in a cellular model of PH1. 2) OxDC can be efficiently encapsulated in human and murine RBCs and does not loose catalytic activity during the encapsulation process. 3) by using directed evolution approaches, a mutated form of OxDC could be engineered that is more resistant to thermal stress and aggregation under physiological conditions as compared with wild-type OxDC. Overall these data provide the proof-of-principle for the feasibility of a therapy for PH based on the administration of RBCs-loaded with an oxalate-degrading enzyme. Future studies will be focused on the testing of the ability of wild-type and engineered OxDC to detoxify oxalate in a mouse model of PH1
The pork food chain as a root of transmission of antimicrobial resistant Escherichia coli: a farm-to-fork perspective
No full textBackground and Objectives
The pork food industry contributes to the spread of antimicrobial resistant (AMR) microorganisms through the food chain and the environment.A significant risk factor is the possible development of Multi Drug Resistance (MDR) and nonsusceptibility to last generation cephalosporins.This study focuses on the pork food chain to evaluate the risk of AMR E. coli transmission from animal to consumer with a focus on cephalosporin resistance.
Material and Methods
Sample collection was carried out in eight fattening pig farms in North Italy from 2019 to 2022. Feces, carcasses, fresh
meat and processed meat products we collected guaranteeing traceability of matrices from farm-to- fork for each animal.
coli were isolated and their ability to resist to aminoglicosides, quinolones, polymixins, glycilcyclines, sulphonamides, βlactams was evaluated with a main focus on ESBL and AmpC production. Phylogenetical analyses were performed
through Enterobacterial Repetitive Intergenic Consensus sequences and Average Nucleotide Identity to confirm possible
relations between the strains isolated from the different production phases.
Results
The most frequent resistance pattern found included β-lactams-aminoglycosides-sulphonamides defining MDR strains in
feces and carcasses, but not in pork meat products. The evaluation of β-lactams resistance highlights percentages
ranging from 7% to 12.5% in fecal, carcass, fresh meat and processed meat product isolates in a increasing order. Data
showed that the 50% of phenotypical AMR bacteria found along the pork food chain were related phylogenetically with
different identity percentages.Considering β-lactamases producing strains, in only one case bacteria were closely
genotypically similar from farm-to-fork (feces, carcasses, and fresh meat). Frequent close similarities were found in
“carcasses and fresh meat”, “carcasses and fermented product”, “feces and fresh meat” and “fresh meat and seasoned
product” isolates.
Discussion and Conclusion
In conclusion, direct transmission of AMR from farm-to-fork is a public health concern and β-lactams AMR transmitted in
only one case. Fresh meat showed a higher risk of AMR transmission than processed meat products.However, the
prudent use of antimicrobials in pig farms, the correct management of food production stages and of the environment
continue to play a strategic role in the spread of AMR microorganisms
Colony Conter Portable Dilemgkapi Tampilan LCD Berbasis Mikrokontroler Atmega 8535
No full textxiii, 137 hlm, ilus: 27 c
SAC3B is a target of CML19, the centrin 2 of Arabidopsis thaliana
No full textArabidopsis centrin 2, also known as calmodulin-like protein 19 (CML19), is a member of the EF-hand superfamily of calcium (Ca2+)-binding proteins. In addition to the notion that CML19 interacts with the nucleotide excision repair protein RAD4, CML19 was suggested to be a component of the transcription export complex 2 (TREX-2) by interacting with SAC3B. However, the molecular determinants of this interaction have remained largely unknown. Herein, we identified a CML19-binding site within the C-terminus of SAC3B and characterized the binding properties of the corresponding 26-residue peptide (SAC3Bp), which exhibits the hydrophobic triad centrin-binding motif in a reversed orientation (I8W4W1). Using a combination of spectroscopic and calorimetric experiments, we shed light on the SAC3Bp-CML19 complex structure in solution. We demonstrated that the peptide interacts not only with Ca2+-saturated CML19, but also with apo-CML19 to form a protein-peptide complex with a 1 : 1 stoichiometry. Both interactions involve hydrophobic and electrostatic contributions and include the burial of Trp residues of SAC3Bp. However, the peptide likely assumes different conformations upon binding to apo-CML19 or Ca2+-CML19. Importantly, the peptide dramatically increases the affinity for Ca2+ of CML19, especially of the C-lobe, suggesting that in vivo the protein would be Ca2+-saturated and bound to SAC3B even at resting Ca2+-levels. Our results, providing direct evidence that Arabidopsis SAC3B is a CML19 target and proposing that CML19 can bind to SAC3B through its C-lobe independent of a Ca2+ stimulus, support a functional role for these proteins in TREX-2 complex and mRNA export
Der „Fall Woyzeck“. Historische Quellen, zeitgenössische Diskurse
No full textSchmideler S, Steinberg H. Der „Fall Woyzeck“. Historische Quellen, zeitgenössische Diskurse. In: Conter C, ed. Literatur und Recht im Vormärz. Jahrbuch des Forum Vormärz Forschung. Vol 15. Bielefeld: Aisthesis; 2010: 41-58
Prevalence and antimicrobial resistance profile in Salmonella spp. isolates from swine food chain
No full textThe aim of this survey was to examine the prevalence and the antimicrobial resistance (AMR) of Salmonella spp. isolated from swine food chain. A total of 435 samples were collected: 360 from slaughterhouse (150 carcasses, 30 cecal samples, 180 environmental samples) and 75 from Italian traditional pork dry sausages. Thirty-six Salmonella were isolated and identified by Polymerase Chain Reaction (PCR): 13,3% (4/30) in fecal samples, 5,5% (10/180) in environmental samples, 7,3% (11/150) in carcasses, and 14,6% (11/75) in Italian traditional dry sausages. Salmonella serotypes were: S. Typhimurium (44,4%), S. Typhimurium monophasic variant (8,3%), S. Typhi (2,8%), S. Enteritidis (22,2%), S. Rissen (16,6%) and S. Derby (5,5%). Phenotypic and genotypic characterization of AMR Salmonella spp. isolates was executed through automatic system (VITEK 2, bioMèrieux) and PCR assays. Salmonella spp. showed phonotypical and genotypical resistance to at least one or more classes of antibiotic. All Salmonella spp. were resistant to aminoglycoside (amikacin and tobramycin) and gentamicin, 86,1% strains were resistant to tetracycline, 55,5% strains were resistant to ampicillin and piperacillin, 25% strains to trimethoprim, 5,5% strains to chloramphenicol, 2,8% strains to amoxicillin/ clavulanic acid, and nitrofurantoin. Among Salmonella isolates, the most detected AMR genes were catA for chloramphenicol (94,4%), nitrofuran nfsA (77.7%), nfsB (86,1%) and, for fluoroquinolone par C (100%) and gyrA (94,4%). This study reported epidemiological data regarding Salmonella spp. and AMR’s circulation in the swine food chain. This phenomenon (AMR) has critical repercussions on the final consumer health; therefore, it represents a crucial One-Health issue
Treatment of childhood acute lymphoblastic leukemia after the first relapse: curative strategies.
No full textLA LEUCEMIA LINFOBLASTICA ACUTA: UN MODELLO DI PERCORSO TERAPEUTICO DELLA PEDIATRIA MODERNA.
No full textAs in the past interested and involvedpeople were willing to leave the shore towardsthe unknown, looking for new andfuture perspectives, in the same way, concerningtherapy of acute lymphoblasticleukaemia, many people, from differentcountries and through alternative routes,sometime converging ones, have undertakena long journey towards the “unknownworld of the disease”. Initiallythey were defeated, as the disease was incurableuntil 50 years ago, but thereafterthey won many battles and got able to obtainabout 80% of cure. Continuous andsystematic research of new “tools andweapons”, more sophisticated and specificones, such as new generation drugs,immunotherapy and gene therapy, arewaited for additional success at shortand long term. Another important goal toachieve is to allow sick children the safestjourney towards the cure, i.e. lacking ofrisks and consequences, regardless theeconomy and the latitude of the countrieswhere the disease shows up. Thisreview aimed to register the “board diary”of this long and not ended journe
- …
