257 research outputs found
The role of selenium peroxidases in the protection against oxidative damage of membranes.
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Dalla Next-Generation Sequencing alla tomografia a emissione di positroni con fluoro-18 fluorodeossiglucosio (18F-FDG) con risonanza magnetica o tomografia computerizzata: tecniche all’avanguardia per supportare la diagnosi delle malattie autoinfiammatorie sistemiche
No full textLe malattie autoinfiammatorie sistemiche (MAIS) comprendono un’ampia varietà di patologie caratterizzate da episodi ricorrenti di infiammazione, in cui risulta fondamentale il ruolo svolto dalle cellule dell’immunità innata. Fino ad ora sono state identificate più di 60 MAIS e con i progressi derivanti dall’espansione delle conoscenze genetiche sono state recentemente identificate nuove patologie. La maggior parte delle MAIS si presenta con episodi di febbre ricorrente, manifestazioni articolari/cutanee, coinvolgimento oculare e/o gastrointestinale o addirittura con quadri di immunodeficienza. Sono state riconosciute diverse classi di MAIS che spaziano dalle “inflammosomopatie”, caratterizzate da processi di disregolazione che coinvolgono i diversi tipi di inflammosoma (pirina, NLRP3, NLRC4, NLRP12...) e che comportano la produzione finale di citochine pro-infiammatorie quali IL-1β e IL-18, alle “interferonopatie” caratterizzate da un intenso rilascio di interferone (IFN)-I; un’altra classe include le patologie da stress del reticolo (sindrome infiammatoria associata al recettore del TNF), mentre altre malattie sono annoverate tra le forme multifattoriali come la malattia di Still ad esordio in età adulta o la recentemente descritta sindrome VEXAS caratterizzata da mutazioni somatiche. Nuove tecniche di analisi genetica come la Next generation sequencing e l'identificazione pannelli di geni sempre più ampi, hanno permesso di ottimizzare il processo diagnostico nella definizione delle malattie autoinfiammatorie sistemiche, nonostante le forme indifferenziate rappresentino ancora circa il 40-60 % dei pazienti con fenotipi compatibili con MAIS, seppur in assenza di mutazioni genetiche conosciute. Tuttavia, è ancora difficile prevedere se l’analisi genetica rileverà una mutazione patogenica basandosi solo sul fenotipo clinico e sull’anamnesi; per questo motivo gli studi funzionali di laboratorio e le tecniche di imaging di terzo livello come la tomografia a emissione di positroni (PET) con risonanza magnetica (RM) o con tomografia computerizzata (TC) stanno diventando esami fondamentali nel supportare il percorso diagnostico dei pazienti. L’obiettivo del presente lavoro è promuovere uno schema di supporto alla diagnosi della MAIS, attraverso l’integrazione di analisi genetica, test funzionali e imaging di terzo livello per poter inquadrare in maniera più precisa le forme autoinfiammatorie indifferenziate e tutti i quadri di infiammazione di origine indeterminata che entrano in diagnosi differenziale con malattie infettive, neoplastiche o linfoproliferative
Hyperinflammation after anti-SARS-CoV-2 mRNA/DNA vaccines successfully treated with anakinra: Case series and literature review
No full textThe current SARS-CoV-2 pandemic diffused worldwide has encouraged the rapid development of vaccines to counter the spread of the virus. At present in Italy, 75.01% of the population completed the vaccination course (AIFA.gov.it) and very few adverse events have been recorded by now. Side-effects related to a theoretical over-reaction of the immune system in response to vaccines administration have been described, and the possibility that an autoimmune or a hyperinflammatory condition may occur was recently observed. Herein, we report four cases of hyperinflammatory syndrome with features indicative of Adult-onset Still’s disease (AOSD) and macrophage activation syndrome (MAS), occurred after anti-SARS-CoV-2 vaccine injection and seen at our Unit between March and May 2021. Since interleukin (IL)-1 is one of the pivotal cytokines involved in AOSD pathogenesis, the inhibition of IL-1 is crucial in ameliorating the clinical symptoms of those patients. Moreover, it has been highlighted the central role of IL-1 as a hallmark of the hyperinflammatory status elicited by SARS-CoV-2 infection. In this case series, we successfully employed the IL-1 receptor antagonist anakinra to curb the cytokine release likely unleashed by the vaccine stimulation in potentially predisposed subjects. We also made a literature search to detect other patients with hyperinflammation temporally related to vaccines injection who benefited from IL-1 inhibition, while other AOSD/MAS-like described syndromes improved with other immunomodulatory strategies
Inhibitory action of neuroleptic drugs and serotonin on dopamine autoxidation and lipid peroxidation
No full text1. Dopamine, like other catecholamines, is normally metabolized by the enzymes monoamino oxidase and catechol-ortho-methyl transferase but it can also undergo oxidation to potentially toxic products, that, in turn, can generate free radicals.
2. In the present paper the effect of neuroleptic drugs (chlorpromazine, trifluoperazine and clozapine) and serotonin on the in vitro oxidation of dopamine and on lipid peroxidation was examined. Serotonin, clozapine, chlorpromazine and trifluoperazine inhibit autoxidation of dopamine both at pH 7.4 and pH 8.5. Trifluoperazine appears more efficient than chlorpromazine while serotonin shows an inhibitory effect intermediate between those of trifluoperazine and chlorpromazine; clozapine has only a moderate effect.
3. The catalytic effect of trace metal seems irrelevant since chelating agents do not show any significant inhibition.
4. All the substances used show a strong antiperoxidative activity.
5. It is concluded that the molecular and biochemical properties of serotonin and neuroleptic drugs on brain dopamine autoxidation and lipid peroxidation could be related to their physiological and clinical effects on mental illness in general and schizophrenia in particular
Intravenous anakinra to curb cytokine storm in adult-onset Still's disease and in macrophage activation syndrome: A case series
No full textObjective: Adult-onset Still's disease (AOSD) is an auto-inflammatory polygenic disorder, for which the diagnosis is essentially clinical. The exclusion of mimickers [such as common bacterial and viral infections, hematologic malignancies, and, more recently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)] is necessary to confirm the diagnosis. Anti-interleukin (IL)-1 therapy is considered a treatment milestone for AOSD. Herein, we present a short series of newly-diagnosed AOSD or upcoming macrophage activation syndrome (MAS) cases who received intravenous (IV) anakinra, an IL-1 receptor blocker. Methods: Four patients with newly-diagnosed AOSD or upcoming MAS were treated with IV anakinra at the Rheumatology Unit of Padova University Hospital, Italy. We obtained informed consent from the patients for use of their cases and medical images for publication purposes. Results: All patients presented with AOSD or MAS during the COVID-19 pandemic, making diagnosis challenging due to similar immunological and clinical characteristics across both pathologies. All patients presented with hyperpyrexia and elevated inflammatory markers; two patients had a skin rash typically seen in AOSD. IV anakinra slowed down AOSD progression in all patients, prevented severe outcomes and mitigated the risk of multiorgan failure. All cases improved within 24hours of anakinra administration. Conclusion: We found that administration of anakinra in patients with newly-diagnosed AOSD and/or upcoming MAS reduced hyperinflammation and prevented life-threatening complications. The IV route appears to be preferable in the hospital setting, where comorbidities such as coagulopathies and thrombocytopenia can complicate the use of other routes of administration
Mitochondrial thioredoxin reductase: purification, inhibitor studies, and role in cell signaling
No full textMitochondrial thioredoxin reductase (TrxR2) maintains thioredoxin (Trx2) in a reduced state and plays a critical role in mitochondrial and cellular functions. TrxR2 has been identified in many different tissues and can be purified to homogeneity from whole organs and isolated mitochondria. Here we describe the detailed steps required to purify this enzyme. A different initial procedure is needed, according to whether purification starts from whole organs or from isolated and purified mitochondria. In the first case, acid precipitation is a critical preliminary step to separate mitochondrial thioredoxin reductase from the cytosolic isoform. Preparation involves ammonium sulfate fractionation, heating, and freeze/thaw cycles, followed by chromatographic passages involving DEAE-Sephacel, 2',5'-ADP-Sepharose 4B affinity, and omega-Aminohexyl-Sepharose 4B columns. The 2',5'-ADP-Sepharose 4B affinity step can be repeated to remove any contaminating glutathione reductase completely. Although several methods are available to detect the activity of this enzyme, reduction of DTNB is an easy and inexpensive test that can be applied not only to the highly purified enzyme but also to lysed mitochondria, provided non-TrxR2-dependent reaction rates are subtracted. TrxR2, like TrxR1, can be inhibited by several different and chemically unrelated substances, usually acting on the C-terminal containing the cysteine-selenocysteine active site. Many of these inhibitors react preferentially with the reduced form of the C-terminal tail. This condition can be evaluated by estimating enzyme activity after removal of the inhibitor by gel filtration of the enzyme preincubated in oxidizing or reducing conditions. Inhibition of thioredoxin reductase has important consequences for cell viability and can lead to apoptosis. Inhibition of TrxR2 causes large production of hydrogen peroxide, which diffuses from the mitochondrion to the cytosol and is responsible for most of the signaling events observed. Methods to measure hydrogen peroxide in isolated mitochondria or cultured cells are described
The amount of cytokine-release defines different shades of Sars-Cov2 infection
No full textThe recent outbreak of coronavirus disease (COVID 19), spreading from China all around the world in early 2020, has led scientists to investigate the immuno-mediated mechanisms underlying the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) infection. Depending on the amount of cytokines released as the result of the immunological activation induced by SARS-CoV2, three major clinical phenotypes can be identified: "mild",symbolized as a "drizzle" of cytokines, severe as a "storm", and critical as a "hurricane". In patients with mild symptoms, the release of pro-inflammatory cytokines is balanced to obtain a defense response against the virus which is often self-limiting and overcomes without tissue damage. In severe phenotype, resembling a "cytokine-release syndrome", SARS-CoV2 causes the lysis of the immune-mediators leading to a cytokine storm able to induce lung epithelium damage and acute respiratory distress syndrome. In critical patients, the immune response may become uncontrolled, thus the cytokine burst resembles a form of secondary hemophagocytic lymphohistiocytosis which may result in a multi organ failure. In addition to the standard of care, an immune-modulatory therapy tailored to each one of the different phenotypes should be used in order to prevent or reduce the release of cytokines responsible for organ damage and disease progression
ANTIOXIDANT ACTION AND PHOTOSENSITIZING EFFECTS OF 3 DIFFERENT CHLORPROMAZINES
No full textChlorpromazine inhibits by about 60% the lipid peroxidation stimulated by Fe2+/ascorbate in liposomes and the lipid peroxidation stimulated by cumene hydroperoxide in microsomes. Under the same conditions, two new synthetic derivatives of chlorpromazine, i.e., a N-benzoyloxymethylchlorpromazine and a N-pivaloyloxymethylchlorpromazine, induce no more than a 20% inhibition. On the other hand, when the different chlorpromazines are entrapped in liposomes and subsequently irradiated with near-UV light, they act as photosensitizing agents giving rise to lipid peroxidation. The latter is quite extensive in the presence of chlorpromazine or N-pivaloyloxymethylchlorpromazine, whereas it is drastically lower in the presence of N-benzoyloxymethylchlopromazine. The N-benzoyloxymethylchlorpromazine molecule, despite its low photodynamic effect, retains its neuroleptic properties. The possible mechanisms of the antioxidant and prooxidant actions of these compounds are discussed
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