64 research outputs found
Study of the cellulose-peptide conjugation for the development of antimicrobial cotton textiles
openThe aim of this thesis is the study of chemoselective ligations in the context of antimicrobial tissues.
Cotton is the chosen textile because it is a natural fiber, widely produced, air permeable and easy to functionalize. The selected class of antimicrobial agents are antimicrobial peptides. In fact, they present a broad-spectrum mechanism of action. Thus, they are at a lower risk for the resistance development; they are produced by the immune system of different organisms, thus inherently biocompatible and biodegradable.
Thiazolidine and oxime bonds are the selected ligation methods. They are formed by the reaction of an aldehyde and a β-amino thiol (Cysteine) and an alkoxyamine (Aminooxyacetic acid), respectively. The use of a covalent bond is due to the requirement to produce a functionalized textile that is durable, washable and reusable.
The aldehyde is introduced at the C6 atom of the glucose unit of cotton cellulose by an enzymatic oxidation in a 2,2,6,6-Tetramethyl-1-piperidinyloxyical(TEMPO)/laccase/O2 system, whereas the Cysteine (Cys) and Aminooxyacetic acid (Aox) are introduced during the peptide synthesis at the N-terminal. Both the oxidizing and the conjugation reactions are interesting for the mild conditions at which they take place.
All the peptides are synthetized through solid phase peptide synthesis (SPPS). Two model peptides are used for the study of the two ligation types. They both have a UV-vis active side chain, a detectable side chain and either a Cys or an Aox. The first is needed to follow the course of the reaction, the second allows to confirm the presence of the peptide on cotton by colorimetric tests and the last two are necessary for the effective ligation with the oxidized cotton. FT-IR analysis is performed to further confirm the presence of the peptides on cotton. The main goals of using these peptides are: the quantification of the peptide loading on different types of cotton, the rough estimation of the aldehyde content on cotton upon the re-use of the oxidizing solution and the evaluation the stability of the two bonds in different media.
Finally, a short analogue of PMAP-36, an antimicrobial peptide, is linked to cotton using the above-mentioned strategy and the antimicrobic activity of the obtained material is tested
Dysphagia-related mucositis in children undergoing chemotherapy: The COMEDY pattern
Objectives Children undergoing chemotherapy can experience dysphagia due to non-erosive reflux disease (NERD). Oral mucositis (OM) associated with NERD-dysphagia in children with cancer has recently been defined with the acronym COMEDY (Clenching, Oral Mucositis, closed Eyes, DYsphagia). This study aims to identify the prevalence of the COMEDY pattern among chemotherapy-induced OM. Subjects and methods Forty-two medical records of children undergoing chemotherapy for haemato-oncologic diseases and presenting OM were reviewed. The following data were collected: age, type of haemato-oncologic disease, presence of dysphagia, type of oral mucosal lesions (i.e. traditional oral mucositis or COMEDY pattern), site of oral lesions, ear-nose-throat (ENT) assessment for the indirect signs of NERD and paediatric neuro-psychiatric (PNP) assessment. Results Among 42 children with chemotherapy-related OM, 6 patients (14.2%) showed the COMEDY pattern. Besides the characteristic clinical aspect of the oral mucosa, initially classified as grade II OM, these children suffered from NERD-related dysphagia and PNP issues. Conclusion A COMEDY pattern can occur in a number of cases of chemotherapy-induced OM; recognizing this pattern may improve the effectiveness of treatment
Fragment-based approach to identify IDO1 inhibitor building blocks
Abstract Indoleamine 2,3-dioxygenase 1 (IDO1) is attracting a great deal of interest as drug target in immune-oncology being highly expressed in cancer cells and participating to the tumor immune-editing process. Although several classes of IDO1 inhibitors have been reported in literature and patent applications, only few compounds have proved optimal pharmacological profile in preclinical studies to be advanced in clinical trials. Accordingly, the quest for novel structural classes of IDO1 inhibitors is still open. In this paper, we report a fragment-based screening campaign that combines Water-LOGSY NMR experiments and microscale thermophoresis approach to identify fragments that may be helpful for the development of novel IDO1 inhibitors as therapeutic agents in immune-oncology disorders
Clostridioides difficile in Calves in Central Italy: Prevalence, Molecular Typing, Antimicrobial Susceptibility and Association with Antibiotic Administration
Idiopathic Aqueductal Stenosis: Late Neurocognitive Outcome in ETV Operated Adult Patients
ObjectiveThe aim of the present study is to evaluate a neurocognitive outcome in patients affected by late-onset idiopathic aqueductal stenosis (LIAS) who underwent endoscopic third ventriculostomy (ETV). Materials and MethodsA prospective study was conducted between January 2015 and December 2017 in a series of 10 consecutive adult patients referred to the Neurosurgery Department of IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy. All the adult patients admitted with absence of CSF flow through the aqueduct in phase-contrast (PC)-MRI sequences or a turbulence void signal in T2-weighted images in midsagittal thin-slice MR sequences underwent a specific neuroradiological, neurological, and neurocognitive assessment pre- and postoperatively. ResultsAll patients affected by gait and sphincter disturbances improved after ETV. Attentive and executive functions as well as visuo-spatial memory and verbal executive functions improved in several patients. Similarly, the affective and behavioral scales improved in almost 50% of the patients. No major complications have been recorded, and no patients required a second surgery for shunt placement. ConclusionEndoscopic third ventriculostomy represents a safe and effective surgical procedure for the treatment of LIAS. In addition to neurological improvement, we demonstrated also postoperative neurocognitive improvement mainly in attentive and executive functions, visuo-spatial memory, verbal executive functions, and behavioral and affective domains
Kidins220/ARMS modulates brain morphology and anxiety-like traits in adult mice
open11: Kinase D interacting substrate of 220 kDa (Kidins220), also known as ankyrin repeat-rich membrane spanning (ARMS), is a transmembrane scaffold protein that participates in fundamental aspects of neuronal physiology including cell survival, differentiation, and synaptic plasticity. The Kidins220 constitutive knockout line displays developmental defects in the nervous and cardiovascular systems that lead to embryonic lethality, which has so far precluded the study of this protein in the adult. Moreover, Kidins220 mRNA is tightly regulated by alternative splicing, whose impact on nervous system physiology has not yet been addressed in vivo. Here, we have asked to what extent the absence of Kidins220 splicing and the selective knockout of Kidins220 impact on adult brain homeostasis. To answer this question, we used a floxed line that expresses only the full-length, non-spliced Kidins220 mRNA, and a forebrain-specific, CaMKII-Cre driven Kidins220 conditional knockout (cKO) line. Kidins220 cKO brains are characterized by enlarged ventricles in the absence of cell death, and by deficient dendritic arborization in several cortical regions. The deletion of Kidins220 leads to behavioral changes, such as reduced anxiety-like traits linked to alterations in TrkB-BDNF signaling and sex-dependent alterations of hippocampal-dependent spatial memory. Kidins220 floxed mice present similarly enlarged brain ventricles and increased associative memory. Thus, both the absolute levels of Kidins220 expression and its splicing pattern are required for the correct brain development and related expression of behavioral phenotypes. These findings are relevant in light of the increasing evidence linking mutations in the human KIDINS220 gene to the onset of severe neurodevelopmental disorders.openAlmacellas-Barbanoj, Amanda; Albini, Martina; Satapathy, Annyesha; Jaudon, Fanny; Michetti, Caterina; Krawczun-Rygmaczewska, Alicja; Huang, Huiping; Manago, Francesca; Papaleo, Francesco; Benfenati, Fabio; Cesca, FabriziaAlmacellas-Barbanoj, Amanda; Albini, Martina; Satapathy, Annyesha; Jaudon, Fanny; Michetti, Caterina; Krawczun-Rygmaczewska, Alicja; Huang, Huiping; Manago, Francesca; Papaleo, Francesco; Benfenati, Fabio; Cesca, Fabrizi
Occurrence and temporal distribution of extended-spectrum β-lactamase-producing Escherichia coli in clams from the Central Adriatic, Italy
The spread of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is a major public health issue. Bivalves are filter-feeder animals capable of bioaccumulating the microorganisms present in water. This physiological characteristic makes them both good indicators of environmental contamination and possible carriers of pathogenic bacteria, including those resistant to antimicrobials. The aim of this study was to investigate the occurrence of ESBL-producing E. coli in clams (n = 308) collected from harvesting areas of the Central Adriatic Sea between 2018 and 2019. ESBL- /class C β-lactamase (AmpC)- producing E. coli and Escherichia spp. were isolated by streaking over the surface of MacConkey agar plates supplemented with cefotaxime enriched broths of the initial shellfish suspension. E. coli and Escherichia spp. resistant to cefotaxime were screened for ESBL production by using the double disk synergy test. Susceptibility to different antimicrobials and confirmation of ESBL-production were determined by the minimum inhibitory concentration (MIC) test. Isolates were further characterized by whole genome sequencing (WGS) and bioinformatic analysis of genomes with different tools. Overall, ESBL-producing E. coli were isolated from 3% of the samples. Of 13 ESBL- and ESBL−/AmpC-producing Escherichia spp. (n = 11 E. coli, n = 1 E. marmotae, n = 1 E. ruysiae) isolates, 13 were resistant to ampicillin and cefotaxime, 9 to sulfamethoxazole, 6 to tetracycline and nalidixic acid, 4 to trimethoprim, and 3 to ceftazidime, cefoxitin, ciprofloxacin, and chloramphenicol. Moreover, the majority (8/11) of the ESBL-producing E. coli isolates were multidrug-resistant. WGS showed that the isolates predominantly carried the blaCTX-M-15 gene (3/11) and blaCTX-M-14 and blaCTX-M-1 (2/11 each). The AmpC β-lactamase CMY-2 was found in two isolates. Phylogroup A was the most prevalent (5/11), followed by phylogroups D (4/11), F (1/11), and B2 (1/11). Ten different sequence types (STs) were identified. Occurrence at sampling sites ranged between 0 and 27%. To identify associations between the occurrence of ESBL-producing E. coli and E. coli levels, samples were divided into two groups, with E. coli at >230 MPN/100 g and E. coli at ≤230 MPN/100 g. ESBL-producing E. coli isolates were significantly more commonly recovered in samples with higher E. coli levels (14%) than in those with lower levels of E. coli (2%). Moreover, the majority (3/4) of the potentially pathogenic strains were isolated in samples with higher E. coli levels. These findings provided evidence for the bacterial indicator of fecal contamination, E. coli, as an index organism for ESBL-producing E. coli isolates in bivalves
Allosteric modulation of metabotropic glutamate receptor 4 activates IDO1-dependent, immunoregulatory signaling in dendritic cells
Metabotropic glutamate receptor 4 (mGluR4) possesses immune modulatory properties in vivo, such that a positive allosteric modulator (PAM) of the receptor confers protection on mice with relapsing-remitting experimental autoimmune encephalomyelitis (RR-EAE). ADX88178 is a newly-developed, one such mGluR4 modulator with high selectivity, potency, and optimized pharmacokinetics. Here we found that application of ADX88178 in the RR-EAE model system converted disease into a form of mild-yet chronic-neuroinflammation that remained stable for over two months after discontinuing drug treatment. In vitro, ADX88178 modulated the cytokine secretion profile of dendritic cells (DCs), increasing production of tolerogenic IL-10 and TGF-β. The in vitro effects required activation of a Gi-independent, alternative signaling pathway that involved phosphatidylinositol-3-kinase (PI3K), Src kinase, and the signaling activity of indoleamine 2,3-dioxygenase 1 (IDO1). A PI3K inhibitor as well as small interfering RNA targeting Ido1-but not pertussis toxin, which affects Gi protein-dependent responses-abrogated the tolerogenic effects of ADX88178-conditioned DCs in vivo. Thus our data indicate that, in DCs, highly selective and potent mGluR4 PAMs such as ADX88178 may activate a Gi-independent, long-lived regulatory pathway that could be therapeutically exploited in chronic autoimmune diseases such as multiple sclerosis
The glycosaminoglycan-binding domain of PRELP acts as a cell type–specific NF-κB inhibitor that impairs osteoclastogenesis
The PRELP heparin sulfate–binding protein translocates to the nucleus, where it impairs NF-κB transcriptional activity, which in turn regulates bone homeostasis
A Relay Pathway between Arginine and Tryptophan Metabolism Confers Immunosuppressive Properties on Dendritic Cells
Arginase 1 (Arg1) and indoleamine 2,3-dioxygenase 1\ua0(IDO1) are immunoregulatory enzymes catalyzing the degradation of L-arginine and L-tryptophan, respectively, resulting in local amino acid deprivation. In addition, unlike Arg1, IDO1 is also endowed with non-enzymatic signaling activity in dendritic cells (DCs). Despite considerable knowledge of their individual biology, no integrated functions of Arg1 and IDO1 have been reported yet. We found that IDO1 phosphorylation and consequent activation of IDO1 signaling in DCs was strictly dependent on prior expression of Arg1 and Arg1-dependent production of polyamines. Polyamines, either produced by DCs or released by bystander Arg1+ myeloid-derived suppressor cells, conditioned DCs toward an IDO1-dependent, immunosuppressive phenotype via activation of the Src kinase, which has IDO1-phosphorylating activity. Thus our data indicate that Arg1 and IDO1 are linked by an entwined pathway in immunometabolism and that their joint modulation could represent an important target for effective immunotherapy in several disease settings
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