25 research outputs found
La psichiatria di consultazione e collegamento nell’ospedale generale: l’esperienza perugina
Objective - This study describes the Consultation-Liaison Service of the Perugia University and investigates the significant associations between a many variables of the assessed population. Results - During the time from July 2008 to June 2009, 722 consultations were performed at the general hospital in Perugia. First examinations were 605. Most consultations involved European patients (95,2%) of female gender (56.3%); mean age was 55.77 (SD ± 21.27). Emergencies were 22.5%; one fifth of patients were not informed of having been referred to our service and half of interventions were requested by departments of internal medicine. The primary reasons for the referral were depression (18.6%), unexplained physical symptoms (12.3%) and anxiety (10.4%); most patients were already taking psychotropic medication before our intervention (58.8%).The significant associations are the following: associations between gender and social status (p < 0.01), social condition (p < 0.01), work (p < 0.01) and advice about the need of the consultation (p < 0.05). The area (medical, surgical and specialized area) are related with the advice (p < 0.05), the reason (p < 0.01) and the type of the consultation (p < 0.01), the diagnostic explanations (p < 0.01), the liaison investigations (p < 0.01) and, at last, with the longrange plan after discharge (p < 0.01)
Hyperbaric oxygen therapy ameliorates osteonecrosis in patients by modulating inflammation and oxidative stress
Early stages of avascular necrosis of the femoral head (AVNFH) can be conservatively treated with hyperbaric oxygen therapy (HBOT). This study investigated how HBOT modulates inflammatory markers and reactive oxygen species (ROS) in patients with AVNFH. Twenty-three male patients were treated with two cycles of HBOT, 30 sessions each with a 30 days break between cycles. Each session consisted of 90 minutes of 100% inspired oxygen at 2.5 absolute atmospheres of pressure. Plasma levels of tumor necrosis factor alfa (TNF-α), interleukin 6 (IL-6), interleukin 1 beta (IL-1β) and ROS production were measured before treatment (T0), after 15 and 30 HBOT sessions (T1 and T2), after the 30-day break (T3), and after 60 sessions (T4). Results showed a significant reduction in TNF-α and IL-6 plasma levels over time. This decrease in inflammatory markers mirrored observed reductions in bone marrow edema and reductions in patient self-reported pain
Normal and pathogenic variation of RFC1 repeat expansions: implications for clinical diagnosis
Cerebellar Ataxia, Neuropathy and Vestibular Areflexia Syndrome (CANVAS) is an autosomal recessive neurodegenerative disease, usually caused by biallelic AAGGG repeat expansions in RFC1. In this study, we leveraged whole genome sequencing (WGS) data from nearly 10,000 individuals recruited within the Genomics England sequencing project to investigate the normal and pathogenic variation of the RFC1 repeat. We identified three novel repeat motifs, AGGGC (n=6 from 5 families), AAGGC (n=2 from 1 family), AGAGG (n=1), associated with CANVAS in the homozygous or compound heterozygous state with the common pathogenic AAGGG expansion. While AAAAG, AAAGGG and AAGAG expansions appear to be benign, here we show a pathogenic role for large AAAGG repeat configuration expansions (n=5). Long read sequencing was used to fully characterise the entire repeat sequence and revealed a pure AGGGC expansion in six patients, whereas the other patients presented complex motifs with AAGGG or AAAGG interruptions. All pathogenic motifs seem to have arisen from a common haplotype and are predicted to form highly stable G quadruplexes, which have been previously demonstrated to affect gene transcription in other conditions. The assessment of these novel configurations is warranted in CANVAS patients with negative or inconclusive genetic testing. Particular attention should be paid to carriers of compound AAGGG/AAAGG expansions, since the AAAGG motif when very large (>500 repeats) or in the presence of AAGGG interruptions. Accurate sizing and full sequencing of the satellite repeat with long read is recommended in clinically selected cases, in order to achieve an accurate molecular diagnosis and counsel patients and their families
Studio di una glutation perossidasi del reticolo endoplasmatico
Cells are continuously facing an oxidative challenge induced by free radicals. These may be generated in different way, i. e. by electron escaping the mitochondrial transport chain, activity of the NADPH oxidase and nitric oxide synthase family of enzymes and autoxidation of favoenzymes. However, the radicals superoxide (*O2- ) and nitric oxide (NO*) do not appear so destructive when produced in tissues. The abundance of superoxide dismutases (SODs) assures that O2*- is immediately dismutated to O2 and the apparently less dangerous H2O2. In pathologic conditions, however, H2O2 is used to produce hypoclorous acid (HOCl) and similarly reactive compounds by the heme peroxidases of leukocytes, or the hydroxyl radical (OH*) by Fenton-like chemistry. Similarly, under these conditions, peroxynitrite (ONOO-) -the reaction product between NO* and *O2- - is transformed into more toxic species. Interestingly, no enzyme has so far been discovered that could detoxify OH*, RO*, singlet oxygen, or HOCl. Evidently, nature was sage enough not to embark in this effort, due to the difficulty to compete with the diffusion-limited reaction of these species on biological targets. However living cells are continuously facing an oxidative challenge and self-protection appears mandatory. This is essentially achieved by preventing radical formation from hydroperoxides (R-OOH) and ONOO-. Interestingly, this appears particularly relevant on the light of the observation that these species may act as mediators of diverse physiological responses such as cell proliferation, differentiation and migration.
The enzymes involved in mammals to handle R-OOH and ONOO-, belong to two distinct protein families, the glutathione peroxidases (GPxs) and the peroxiredoxins (Prxs). Both act on H2O2 and on ONOO- -although ONOO- is generally believed to be a better substrate for Prx than GPxs- and, also, on a wide spectrum of alkyl hydroperoxides comprising the products of lipoxygenases.
GPxs are widely distributed in nature, from bacteria to humans. They use either selenium or sulfur in the redox center that is oxidized by the hydroperoxide, thus forming an oxidized enzyme intermediate, which is regenerated in its reduced form by a reductant. This is not always glutathione (GSH), as the name of the family should suggest. The redox center is remarkably conserved in the whole family and it is made of a catalytic tetrad containing Sec or Cys, Gln, Trp and Asn. When it contains selenium, as it typically occurs in mammalian GPx -the ‘SecGPxs’- the oxidized intermediate formed upon reaction of the catalytic moiety with the R-OOH -believed to be a selenol (SeO-)- is reduced by GSH. In this reaction a selenodisulfide intermediate is formed, that is displaced by a second GSH, yielding GSSG and reduced enzyme. When it contains sulphur, instead, as in the GPxs of non-vertebrates and plants (CysGPxs), the reducing substrate is a Trx or a ‘redoxin’ of the Trx family, and an intrachain disulphide is the oxidized intermediate of the enzyme. This mechanism requires, besides the ‘peroxidatic Cys ‘(CP), a second ‘resolving Cys’ (CR). The sole monomeric SecGPx of vertebrates -GPx4- does not bear the CR residue, is active on GSH and, obviously, does not form the intermediate intrachain selenodisulfide.
The ‘canonic mechanism’ of GPxs, involving a CR when the redox center is a CP instead of a ‘peroxidatic Sec’ (UP) and the consequent use of Trx or ‘redoxins’ as the reducing substrate for the intermediate disulphide (CP - CR) has been challenged by the discovery of GPx7 and GPx8 in mammals. These are two monomeric GPxs of the endoplasmic reticulum (ER), containing a CP but missing a Cys residue –located within the aminoacid stretch of the alpha 4 helix of the GPx thioredoxin fold- where the CR residue of non-vertebrate and plants GPxs is found.
Here, GPx7 has been characterized as the prototype of these unusual 1CysGPx.
Although at low levels, GPx7 is widely distributed in tissues. Both, its NH2-terminal peptide and the C terminal KREDL motif proved to be functional to ER entrance and retention respectively. Kinetic studies on GPx7 have been carried out using phospholipid hydroperoxides, the most appropriate for monomeric GPxs, using the enzyme expressed in E. coli, fused with synuclein to overcome an otherwise very poor expression. From steady state kinetics the rate constant for the oxidation of the active site resulted rather high (k+1=9.5 x E03 M-1sec-1), whilst the rate of the regeneration of the catalyst by GSH remarkably low (k’+2=12.6 M-1sec-1). Unexpectedly, the oxidized active site is instead rapidly reduced by a ‘redoxin’, protein disulfide isomerase (PDI) (k’+2=3.5 x E03 M-1sec-1), but not by Trx. This evidence was corroborated by the affinity constant for PDI measured by SPR (KD= 5.2 µM). Furthermore the presence in GPx7 of a Cys residue replacing the resolving function of the CR of non-vertebrates and plants GPxs, was ruled out by mutagenesis. Thus, the ‘canonical mechanism’ by which in GPx a CR is required for being reduced by a ‘redoxin’ does not apply to GPx7. This enzyme indeed accepts electrons from a ‘redoxin’ such as PDI by a mechanism involving the CP only. GPx7, and the structurally similar GPx8, therefore, represent rare exceptions within the family of glutathione peroxidases, for being 1CysGPx preferentially reduced by a ‘redoxin’. In fact the GPxs family is mostly contributed by the non-vertebrates ‘2CysGPx’ that are functionally Trx peroxidases.
Although these data frame the physiological function of GPx7 in the area of oxidative folding of proteins in ER, no evidence was obtained in this respect. Searching for adaptive response to ER stress alternative to the unfolded protein response (UPR), we observed increased phosphorylation of the extracellular signal regulated kinase 1-2 (ERK 1-2) by GPx7 silencing following a proliferative stimulus by the fibroblast growth factor (FGF). These data finalize the enzymatic characterization of GPx7 as a ‘non-canonical’ member of the GPxs family, do not support the role in ER stress but envisage a role in the cross talk between the redox status of ER and growth factor signaling.Le cellule vanno continuamente incontro a ‘stress ossidativo’ indotto da radicali liberi. Questi possono essere generati in diversi modi, ad esempio da elettroni che sfuggono alla catena respiratoria mitocondriale, dall'attività delle NADPH ossidasi o dalle ossido nitrico sintasi e dalla autossidazione di flavoenzimi. Tuttavia, i radicali superossido (*O2-) e ossido nitrico (NO*) non appaiono così distruttivi per i tessuti. L'abbondanza di superossido dismutasi (SOD) assicura che l’ *O2- sia immediatamente dismutato a O2 e H2O2, una sostanza apparentemente meno pericolosa. Ciò non toglie che, in condizioni patologiche, l’H2O2 possa essere usata per produrre acido ipocloroso (HOCl) e altri composti reattivi dalle eme perossidasi dei leucociti, oppure per produrre il radicale idrossile (OH*) attraverso la reazione di Fenton. Allo stesso modo, in queste condizioni, il perossinitrito (ONOO-), prodotto di reazione tra NO* e *O2-, si trasforma in specie più tossiche. È interessante notare il fatto che non sia stato mai trovato enzima capace di detossificare OH*, RO*, ossigeno singoletto, oppure HOCl. Evidentemente, la natura è stata saggia abbastanza da non impegnarsi in uno sforzo impossibile, per la difficoltà di competere con l’altissima reattività di queste specie su bersagli biologici, limitata solo dalla diffusione. Tuttavia le cellule devono costantemente affrontare ‘stress ossidativo’ e pertanto l’autoprotezione è obbligatoria. Questa è perseguita prevenendo la formazione di radicali dagli idroperossidi (R-OOH) e dal perossinitrito. Ciò è particolarmente rilevante alla luce del fatto che queste sostanze stanno emergendo come mediatori di diverse risposte fisiologiche quali la proliferazione, la differenziazione e la migrazione cellulare. Gli enzimi dei mammiferi implicati nella detossificazione degli R-OOH e ONOO- appartengono a due distinte famiglie di proteine, le glutatione perossidasi (GPxs) e le peroxiredossine (Prx). Entrambi agiscono sull’H2O2 o sul ONOO- - anche se, generalmente il ONOO- è ritenuto substrato migliore per le Prx rispetto alle GPxs – e, inoltre, su un ampio spettro di idroperossidi alchilici comprendenti i prodotti della lipossigenasi.
Le GPxs sono ampiamente distribuite in natura, dai batteri all'uomo. Utilizzano sia selenio che zolfo nel centro catalitico ossidoriduttivo, che viene ossidato dall’R-OOH, formando così un intermedio ossidato che viene rigenerato da un agente riducente. Questo non è sempre glutatione (GSH), come il nome di questa famiglia di enzimi potrebbe suggerire. Il centro redox delle GPxs è notevolmente conservato in tutta la famiglia ed è costituito da una tetrade catalitica composta da Sec o Cys, Gln, Trp e Asn. Quando contiene selenio, come tipicamente nelle GPx dei mammiferi – le ‘SecGPxs’-, l’intermedio ossidato, formatosi dalla reazione del centro catalitico con l’R-OOH, probabilmente il selenolo (SeO-), viene ridotto dal GSH, il quale forma un intermedio selenodisulfuro che viene poi ridotto da una seconda molecola di GSH, con produzione di GSSG ed enzima ridotto. Quando invece contiene zolfo, come tipicamente nelle GPxs dei non-vertebrati e nelle piante (CysGPxs), il substrato riducente è una preferenzialmente la tioredossina (Trx) o una ‘redossina’ della famiglia delle Trxs, e l'intermedio ossidato dell’enzima è un disolfuro intracatena. Per questo è necessario, oltre alla ‘Cys perossidasica’ (CP), un secondo residuo di Cys la ‘Cys resolving’ (CR). L'attuale, unica SecGPx monomerica nei vertebrati - la GPx4- non presenta il residuo CR, è ridotta dal GSH e ovviamente non forma un intermedio selenodisulfuro intracatena.
Il ‘meccanismo canonico’ delle GPxs, che implica quindi una CR quando il centro redox è una CP invece di una Sec perossidasica (UP) e quindi l’uso di preferenziale di Trx o altre ‘redossine’ come substrato riducente, è stato rimesso in discussione dalla scoperta, nei mammiferi, di due nuove GPx, la GPx7 e la GPx8. Queste sono due GPx monomeriche del reticolo endoplasmatico (ER), contenenti una CP, senza un residuo di Cys nello ‘stretch’ di aminoacidi dove si trova la CR delle altre CysGPx dei non-vertebrati e delle piante.
In questa tesi, abbiamo caratterizzato la GPx7, come prototipo di queste insolite ‘1CysGPx’.
Anche se a bassi livelli, la GPx7 è ampiamente distribuita nei tessuti. Il peptide segnale presente all’estremità NH2-terminale e il motivo C-terminale KREDL sono funzionali per l’ingresso e la ritenzione nell’ER, rispettivamente. Gli studi cinetici sulla GPx7 sono stati effettuati su idroperossidi fosfolipidi (PL-OOH), il substrato più appropriato per le GPxs monomeriche, utilizzando enzima espresso in E. coli, fuso con sinucleina per ottenere alti livelli di espressione. Dalla cinetica in stato stazionario, la costante cinetica per l'ossidazione del sito attivo è risultata piuttosto elevata (k+1=9.5 x E03 M-1sec-1), mentre costante cinetica per la rigenerazione del catalizzatore con GSH notevolmente bassa (k’+2=12.6 M-1sec-1). Sorprendentemente, il sito attivo ossidato è invece rapidamente ridotto da una ‘redossina’, la protein disulfide isomerase (PDI) (k’+2=3.5 x E03 M-1sec-1) ma non dalla Trx. L’interazione PDI-GPx7 è stata confermata dalla misura della costante di affinità della GPx7 per la PDI mediante SPR (KD= 5.2 µM). Inoltre è stata esclusa, mediante mutagenesi, la eventuale presenza nella GPx7 di un residuo Cys che possa fare la funzione della CR tipica delle GPxs dei non-vertebrati e delle piante. Quindi, il ‘meccanismo canonico’ mediante il quale nelle GPxs è richiesta una CR per essere ridotte da una ‘redossina’ non si applica alla GPx7 (e probabilmente neanche alla GPx8, che è strutturalmente simile). Questo enzima infatti, accetta elettroni da un ‘redossina’ come la PDI attraverso un meccanismo che implica la sola CP. La GPx7 (e la GPx8) si configurano quindi come insolite ‘1CysGPx’ della famiglia delle glutation perossidasi, poiche’ sono di fatto rare eccezioni. Infatti, la famiglia delle glutation perossidasi è per la maggior parte composta da ‘2CysGPx’ dei non-vertebrati e delle piante che sono funzionalmente Trx perossidasi.
Sebbene questi dati sembrerebbero inquadrare la funzione fisiologica della GPx7 nel ‘protein folding’ che avviene nell’ER, nessuna evidenza è stata da noi ottenuta in questo senso. In cerca di una risposta adattativa alternativa all’unfolded protein response (UPR), abbiamo osservato un aumento di fosforilazione della extracellular signal regulated kinase 1-2 (ERK 1-2) in seguito al silenziamento della GPx7 dopo uno stimolo proliferativo con il fattore di crescita dei fibroblasti (FGF). Questi dati finalizzano la caratterizzazione enzimatica della GPx7 come un membro ‘non-canonico’ della famiglia delle GPxs, non suggeiscono un ruolo nello stress del ER, ma indicano invece un ruolo nel cross talk tra lo stato redox del ER e segnali provenienti da fattori di crescita
Band 3 tyr-phosphorylation in human erythrocytes from non-pregnant and pregnant women.
Pregnancy is associated with changes in circulating red blood cells, mainly involving band 3 protein and membrane lipid peroxidation. Membrane band 3 is a multifunctional protein containing four Tyr-phosphorylatable residues which modulate the physiological status of erythrocytes by regulating glycolysis, cell shape and membrane transport. Erythrocytes from nine pregnant and 12 age-matched non-pregnant healthy women were subjected to oxidative and hyperosmotic stress conditions and the extent of band 3 Tyr-phosphorylation and membrane Syk recruitment as a membrane marker were evaluated. Results indicated that, in pregnancy, red blood cells show a decrease in band 3 Tyrphosphorylation and a clear-cut rearrangement of band 3 protein within the membrane. In fact, band 3 shows a decrease in high molecular weight aggregates (HMWA), with different subdivision between Triton-soluble and -insoluble compartments, and an increase in proteolytic fragments. In conclusion, it is demonstrated that pregnancy is associated with membrane adjustments which reduce the sensitivity of erythrocytes to both oxidative and osmotic stress. Band 3 Tyr-phosphorylation is proposed as a new parameter in the evaluation of erythrocyte membrane arrangement
Inhaled mucoactive drugs for treating non-cystic fibrosis bronchiectasis in children
Abstract
Non-cystic fibrosis bronchiectasis (nCFb) is an acquired condition of variable etiology. Medical treatment basically involves antibiotics and chest physiotherapy. An impaired mucociliary clearance seems to be one of the mechanisms behind nCFb, and inhaled therapy with mucoactive agents has frequently been used to try to correct it. The most often used mucoactive agents in this setting are N-acetylcysteine, hypertonic saline solution (HS), mannitol powder and recombinant human DNase (rhDNase). Reviewing the international medical literature on the use of these drugs for patients with nCFb from 1992 to the present day, we retrieved 88 articles, only 12 of which met our selection criteria for this analysis. We found only 2 papers and 2 reviews on the use of rhDNase in children, and in adults 3 trials on HS, 5 on mannitol powder and 2 on rhDNase. In conclusion, no observational or randomized controlled trials (RCT) have been published on the use of these drugs in children with nCFb, while the few conducted on adult patients report some evidence of their effects. Further studies are needed on inhaled mucoactive drugs for the treatment of children with nCFb
Hyperbaric Oxygen Therapy Improves the Osteogenic and Vasculogenic Properties of Mesenchymal Stem Cells in the Presence of Inflammation In Vitro
Hyperbaric oxygen (HBO) therapy has been reported to be beneficial for treating many conditions of inflammation-associated bone loss. The aim of this work was to in vitro investigate the effect of HBO in the course of osteogenesis of human Mesenchymal Stem Cells (MSCs) grown in a simulated pro-inflammatory environment. Cells were cultured with osteogenic differentiation factors in the presence or not of the pro-inflammatory cytokine Tumor Necrosis Factor-α (TNF-α), and simultaneously exposed daily for 60 min, and up to 21 days, at 2,4 atmosphere absolute (ATA) and 100% O2. To elucidate osteogenic differentiation-dependent effects, cells were additionally pre-committed prior to treatments. Cell metabolic activity was evaluated by means of the MTT assay and DNA content quantification, whereas osteogenic and vasculogenic differentiation was assessed by quantification of extracellular calcium deposition and gene expression analysis. Metabolic activity and osteogenic properties of cells did not differ between HBO, high pressure (HB) alone, or high oxygen (HO) alone and control if cells were pre-differentiated to the osteogenic lineage. In contrast, when treatments started contextually to the osteogenic differentiation of the cells, a significant reduction in cell metabolic activity first, and in mineral deposition at later time points, were observed in the HBO-treated group. Interestingly, TNF-α supplementation determined a significant improvement in the osteogenic capacity of cells subjected to HBO, which was not observed in TNF-α-treated cells exposed to HB or HO alone. This study suggests that exposure of osteogenic-differentiating MSCs to HBO under in vitro simulated inflammatory conditions enhances differentiation towards the osteogenic phenotype, providing evidence of the potential application of HBO in all those processes requiring bone regeneration
Botulinum a toxin intravesical injections for painful bladder syndrome: impact upon pain, psychological functioning and quality of life
INTRODUCTION:
To assess the impact of intravesically injected botulinum A toxin (BoNT/A) upon bladder pain, urological complaints, symptoms of anxiety and depression, and Quality of Life (QoL) in patients with painful bladder symptoms (PBS) refractory to conventional treatment.
PATIENTS AND METHODS:
In this prospective study 14 patients received one injection of BoNT/A (200 U diluted in 20 ml 0.9% NaCl), under cystoscopic guidance. At pre- and 3 months post- treatment all patients underwent an urological assessment (voiding diary, urodynamics), a pain quantification on a visual analog scale (VAS), an evaluation with the 14-item Hamilton Anxiety Rating Scale (HAM-A) to assess symptoms of psychic and somatic anxiety, an evaluation with the Hamilton Depression Rating Scale (HAM-D) to assess depression, and the 36-item Medical Outcomes Study Short Form (SF-36) to assess QoL. Results. At pre-treatment all 14 patients had increased daytime and nighttime urinary frequency and high VAS scores. Nine patients had pathological HAM-A scores and all had pathological HAM-D scores. At the 3-month follow-up 10/14 patients reported a subjective improvement in pain. Mean VAS score, mean daytime and nighttime urinary frequency decreased significantly (p <0.01, <0.01 and <0.01, respectively). All domains in SF-36 and HAM-A significantly improved (p<0.01). All domains, except weight and sleep disorders, significantly improved in HAM-D, particularly somatoform symptoms (p<0.01), cognitive performance (p<0.01), and circadian variations (p<0.01).
CONCLUSION:
In patients with refractory PBS with symptoms of anxiety, depression and poor QoL, BoNT/A intravesical treatment reduced bladder pain, improved psychological functioning, and well-being
Review on hyperbaric oxygen treatment in femoral head necrosis
Femoral head necrosis (FHN) is a common invalidating disease with an unclear etiology and pathophysiology that affects middle-aged people. FHN may lead to joint collapse and require invasive treatments. Because of its clinical and socioeconomic significance, an early diagnosis, staging and appropriate treatment are required. Unfortunately, to date a unique algorithm for the treatment of FHN has not been defined
Spirometry and oxidative stress after rebreather diving in warm water
Hyperbaric oxygen (HBO\u2082) therapy and use of enriched air can result in oxidative injury affecting the brain, lungs and eyes. HBO\u2082 exposure during diving can lead to a decrease in respiratory parameters. However, the possible effects of acute exposure to oxygen-enriched diving on subsequent spirometric performance and oxidative state in humans have not been recently described recently. We aim to investigate possible effects of acute (i) hyperbaric and (ii) hyperbaric hyperoxic exposure using scuba or closed-circuit rebreather (CCR) on subsequent spirometry and to assess the role of oxidative state after hyperoxic diving