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"Leoni, Valerio"
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Old and New Beta-Lactamase Inhibitors: Molecular Structure, Mechanism of Action, and Clinical Use
2021
The β-lactams have a central place in the antibacterial armamentarium, but the increasing resistance to these drugs, especially among Gram-negative bacteria, is becoming one of the major threats to public health worldwide. Treatment options are limited, and only a small number of novel antibiotics are in development. However, one of the responses to this threat is the combination of β-lactam antibiotics with β-lactamase inhibitors, which are successfully used in the clinic for overcoming resistance by inhibiting β-lactamases. The existing inhibitors inactivate most of class A and C serine β-lactamases, but several of class D and B (metallo-β-lactamase) are resistant. The present review provides the status and knowledge concerning current β-lactamase inhibitors and an update on research efforts to identify and develop new and more efficient β-lactamase inhibitors.
Journal Article
A fully-virulent retargeted oncolytic HSV armed with IL-12 elicits local immunity and vaccine therapy towards distant tumors
by
Campadelli-Fiume, Gabriella
,
Zaghini, Anna
,
Lollini, Pier-Luigi
in
Antiviral agents
,
Attenuation
,
Biology and Life Sciences
2018
Oncolytic herpes simplex viruses (oHSVs) showed efficacy in clinical trials and practice. Most of them gain cancer-specificity from deletions/mutations in genes that counteract the host response, and grow selectively in cancer cells defective in anti-viral response. Because of the deletions/mutations, they are frequently attenuated or over-attenuated. We developed next-generation oHSVs, which carry no deletion/mutation, gain cancer-specificity from specific retargeting to tumor cell receptors-e.g. HER2 (human epidermal growth factor receptor 2)-hence are fully-virulent in the targeted cancer cells. The type of immunotherapy they elicit was not predictable, since non-attenuated HSVs induce and then dampen the innate response, whereas deleted/attenuated viruses fail to contrast it, and since the retargeted oHSVs replicate efficiently in tumor cells, but spare other cells in the tumor. We report on the first efficacy study of HER2-retargeted, fully-virulent oHSVs in immunocompetent mice. Their safety profile was very high. Both the unarmed R-LM113 and the IL-12-armed R-115 inhibited the growth of the primary HER2-Lewis lung carcinoma-1 (HER2-LLC1) tumor, R-115 being constantly more efficacious. All the mice that did not die because of the primary treated tumors, were protected from the growth of contralateral untreated tumors. The long-term survivors were protected from a second contralateral tumor, providing additional evidence for an abscopal immunotherapeutic effect. Analysis of the local response highlighted that particularly R-115 unleashed the immunosuppressive tumor microenvironment, i.e. induced immunomodulatory cytokines, including IFNγ, T-bet which promoted Th1 polarization. Some of the tumor infiltrating cells, e.g. CD4+, CD335+ cells were increased in the tumors of all responders mice, irrespective of which virus was employed, whereas CD8+, Foxp3+, CD141+ were increased and CD11b+ cells were decreased preferentially in R-115-treated mice. The durable response included a breakage of tolerance towards both HER2 and the wt tumor cells, and underscored a systemic immunotherapeutic vaccine response.
Journal Article
Presence of cholesterol oxides in milk chocolates and their correlation with milk powder freshness
2022
Cholesterol oxidation products (COPs) of non-enzymatic origin are mainly found in meat, fish, eggs and milk, mostly originating from the type of feeding, processing and storage. To verify the significance of COPs as biomarkers of cholesterol autoxidation and milk freshness, we quantified them in chocolates containing whole milk powders (WMPs) of increasing shelf-lives (i.e. 20, 120, and 180 days). Non-enzymatic total COPs (both free and esterified) ranged from 256.57 ± 11.97 to 445.82 ± 11.88 ng/g, increasing proportionally to the shelf-life of the WMPs, thus reflecting the ingredients’ freshness. Based on the expected theoretical COPs, the effect of processing was quantitatively less significant in the generation of oxysterols (41–44%) than the contribution of the autoxidation of the WMPs over time (56–59%), pointing to the shelf-life as the primary determinant of COPs. Lastly, we quantified COPs of major commercial milk chocolates on the Italian market, which followed a similar distribution (from 240.79 ± 11.74 to 475.12 ± 12.58 ng/g). Although further replications of this work are needed, this study reports preliminary results and a practical example of a first application of non-enzymatic COPs as markers to further quantify and characterize the nutritional quality and freshness, not only of ingredients but also of composite products.
Journal Article
Alteration of Lipid Metabolism in Patients with IPF and Its Association with Disease Severity and Prognosis: A Case–Control Study
2025
The pathogenesis of idiopathic pulmonary fibrosis (IPF) involves complex interactions between epithelial, mesenchymal, immune, and endothelial cells, often aggravated by lipid metabolism dysfunction, mitochondrial, and peroxisomal abnormalities. Changes in lipid metabolism may drive fibrotic processes, suggesting the potential of lipid biomarkers for disease monitoring. We compared here the cholesterol metabolism and very-long-chain fatty acid profiles of patients with IPF with healthy controls. The IPF patients’ lipidic profiles were also evaluated according to disease severity and progression rate. This prospective, observational study involved 50 IPF patients at disease diagnosis before antifibrotic treatment initiation and 50 age- and gender-matched healthy controls. Using a serum lipidomic profile, we focused on cholesterol synthesis, mitochondrial and peroxisomal markers, inflammatory lipids, and oxidative stress markers. Disease severity was evaluated using the Gender-Age-Physiology (GAP) index, while the prognosis was assessed by classifying patients as rapid or slow progressors based on a 24-month follow-up. IPF patients exhibited lower levels of cholesterol synthesis precursors (e.g., lathosterol), mitochondrial oxysterols, and inflammatory mediators (e.g., arachidonic acid) compared to controls. Reduced levels of these biomarkers were also associated with higher disease severity and rapid disease progression. Conversely, some peroxisomal markers (e.g., brassidic acid and nervonic acid) showed altered trends depending on disease severity. Our findings indicate that patients with IPF, compared to healthy controls, may show lipidomic alterations, particularly a reduction in cholesterol precursors and docosahexaenoic acids, which are also associated with IPF severity and progression. While preliminary, this study suggests lipidomics to be a promising tool to stratify IPF severity and prognosis.
Journal Article
Effect of packaging in preventing cholesterol autoxidation in milk chocolates for a higher quality and safer shelf-life
2023
Non-enzymatic cholesterol oxidation products (COPs) are nowadays receiving increasing attention in food technology for their potential use as biomarkers of freshness and safety in raw materials and complex food matrices, as well as markers of cholesterol oxidation during the production and shelf-life of end products. Here reported is the investigation of how long three prototype milk chocolates containing whole milk powders (WMPs) of increasing shelf-lives (i.e. 20, 120, and 180 days), could be safely stored in the market by adopting the non-enzymatic COPs as a quality markers. In addition, the protective effect of two different primary packaging, sealed and unsealed ones, in mitigating the generation of non-enzymatic COPs in three prototype milk chocolates after 3, 6, 9, 12 months of shelf-life was assessed to simulate two real storage conditions. Quantifying oxysterols’ levels by mass spectrometry, the oxygen impermeable packaging (PLUS) resulted to significantly quench the non-enzymatic COPs production up to 34% as to that found in the same product but with unsealed standard packaging (STD). This study represents one practical application of non-enzymatic COPs as a reliable tool for corrective strategies to prevent food oxidation.
Journal Article
Purple corn extract induces long-lasting reprogramming and M2 phenotypic switch of adipose tissue macrophages in obese mice
by
Leoni, Valerio
,
Mock, Hans-Peter
,
Petroni, Katia
in
Adipose tissue
,
Adipose tissues
,
Anthocyanins
2019
Background
Obesity is a chronic and systemic inflammatory disorder and an important risk factor for the onset of several chronic syndromes. Adipose tissue (AT) plays a crucial role in the development of obesity, promoting the infiltration and accumulation of leukocytes in the tissue and sustaining adipocyte expansion. Anthocyanins exert a broad range of health benefits, but their effect in improving obesity-related inflammation in vivo has been poorly characterized. We examined the effects of a purple corn cob extract in the context of AT inflammation in a murine diet-induced obesity (DIO) model.
Methods
Male C57BL/6J mice were subjected to control diet (CTR + H
2
O), high fat diet (HF + H
2
O) or high fat diet plus purple corn extract (HF + RED) for 12 weeks. Blood glucose, AT, and liver gene expression, metabolism, biochemistry, and histology were analysed and flow cytometry was performed on AT leukocytes and Kupffer cells.
Results
RED extract intake resulted in lower MCP-1 mediated recruitment and proliferation of macrophages into crown-like structures in the AT. AT macrophages (ATM) of HF + RED group upregulated M2 markers (
ArgI
,
Fizz1
,
TGFβ
), downregulating inflammatory mediators (
TNF
-
α
,
IL
-
6
,
IL
-
1β
,
COX
-
2
) thanks to the suppression of NF-kB signalling. ATM also increased the expression of iron metabolism-related genes (
FABP4
,
Hmox1
,
Ferroportin
,
CD163
,
TfR1
,
Ceruloplasmin
,
FtL1
,
FtH1
) associated with a reduction in iron storage and increased turnover. ATM from HF + RED mice did not respond to LPS treatment ex vivo, confirming the long-lasting effects of the treatment on M2 polarization. Adipocytes of HF + RED group improved lipid metabolism and displayed a lower inflammation grade. Liver histology revealed a remarkable reduction of steatosis in the HF + RED group, and Kupffer cell profiling displayed a marked switch towards the M2 phenotype.
Conclusions
RED extract attenuated AT inflammation in vivo, with a long-lasting reprogramming of ATM and adipocyte profiles towards the anti-inflammatory phenotype, therefore representing a valuable supplement in the context of obesity-associated disorders.
Journal Article
Antimicrobial Resistance Patterns of Enterobacter cloacae and Klebsiella aerogenes Strains Isolated from Clinical Specimens: A Twenty-Year Surveillance Study
by
Siracusa, Claudia
,
Leoni, Valerio
,
Intra, Jari
in
Aerogenes
,
Aminoglycosides
,
Antibiotic resistance
2023
We retrospectively analyzed the antimicrobial data of Enterobacter spp. strains isolated from hospitalized subjects and outpatients over 20 years (2000–2019). A total of 2277 non-duplicate Enterobacter spp. isolates, 1037 from outpatients (45%) and 1240 from hospitalized subjects (55%), were retrieved. Most of samples are infections of the urinary tract. Considering Enterobacter aerogenes, now classified as Klebsiella aerogenes, and Enterobacter cloacae, representing more than 90% of all isolates, except for aminoglycosides and fluroquinolones, which showed significant antibiotic decreasing trends (p < 0.01), none of the other antimicrobial agents tested showed significant changes in both groups (p > 0.05). Conversely, there was a significant increasing resistance trend for fosfomycin (p < 0.01), among both community and hospital-related subjects, most probably owing to uncontrolled and improper usage. Surveillance studies on antibiotic resistance at the local and regional level are required to detect new resistance mechanisms, reduce inappropriate antimicrobial consumption, and increase the focus on antimicrobial stewardship.
Journal Article
Effect of packaging in preventing cholesterol autoxidation in milk chocolates for a higher quality and safer shelf-life
2023
Non-enzymatic cholesterol oxidation products (COPs) are nowadays receiving increasing attention in food technology for their potential use as biomarkers of freshness and safety in raw materials and complex food matrices, as well as markers of cholesterol oxidation during the production and shelf-life of end products. Here reported is the investigation of how long three prototype milk chocolates containing whole milk powders (WMPs) of increasing shelf-lives (i.e. 20, 120, and 180 days), could be safely stored in the market by adopting the non-enzymatic COPs as a quality markers. In addition, the protective effect of two different primary packaging, sealed and unsealed ones, in mitigating the generation of non-enzymatic COPs in three prototype milk chocolates after 3, 6, 9, 12 months of shelf-life was assessed to simulate two real storage conditions. Quantifying oxysterols’ levels by mass spectrometry, the oxygen impermeable packaging (PLUS) resulted to significantly quench the non-enzymatic COPs production up to 34% as to that found in the same product but with unsealed standard packaging (STD). This study represents one practical application of non-enzymatic COPs as a reliable tool for corrective strategies to prevent food oxidation.
Journal Article
Enhanced molecular release from elderly bone samples using collagenase I: insights into fatty acid metabolism alterations
2024
Background
Bone is a metabolically active tissue containing different cell types acting as endocrine targets and effectors. Further, bone is a dynamic depot for calcium, phosphorous and other essential minerals. The tissue matrix is subjected to a constant turnover in response to mechanical/endocrine stimuli. Bone turnover demands high energy levels, making fatty acids a crucial source for the bone cells. However, the current understanding of bone cell metabolism is poor. This is partly due to bone matrix complexity and difficulty in small molecules extraction from bone samples. This study aimed to evaluate the effect of metabolite sequestering from a protein-dominated matrix to increase the quality and amount of metabolomics data in discovering small molecule patterns in pathological conditions.
Methods
Human bone samples were collected from 65 to 85 years old (the elderly age span) patients who underwent hip replacement surgery. Separated cortical and trabecular bone powders were treated with decalcifying, enzymatic (collagenase I and proteinase K) and solvent-based metabolite extraction protocols. The extracted mixtures were analyzed with the high-resolution mass spectrometry (HRMS). Data analysis was performed with XCMS and MetaboAnalystR packages.
Results
Fast enzymatic treatment of bone samples before solvent addition led to a significantly higher yield of metabolite extraction. Collagenase I and proteinase K rapid digestion showed more effectiveness in cortical and trabecular bone samples, with a significantly higher rate (2.2 folds) for collagenase I. Further analysis showed significant enrichment in pathways like de novo fatty acid biosynthesis, glycosphingolipid metabolism and fatty acid oxidation-peroxisome.
Conclusion
This work presents a novel approach for bone sample preparation for HRMS metabolomics. The disruption of bone matrix conformation at the molecular level helps the molecular release into the extracting solvent and, therefore, can lead to higher quality results and trustable biomarker discovery. Our results showed β-oxidation alteration in the aged bone sample. Future work covering more patients is worthy to identify the effective therapeutics to achieve healthy aging.
Journal Article