Quantitation of oxidized and reduced albumin in mammals. An intriguing analytical question.

Oxidized albumin is considered a short-term biomarker of oxidative stress and its measurement in blood contributes to evaluate the impact of diseases, drugs, dialytic treatments, physical activity, environmental contaminants etc. on the red-ox balance of humans as well as of other mammalians. Nevertheless, the most common methods for quantifying the oxidized and reduced albumins are costly and time-consuming. Furthermore, there is a dearth of information regarding the proper ways to store human serum or plasma samples in order to prevent inaccurate quantification of these various albumin forms. This paper explores these aspects and proposes a few spectrophotometric assay procedures which make the quantitation of oxidized and reduced albumin very fast, precise and un-expensive in various mammals.

Erythrocyte glutathione transferase. A sensitive Up-Down biomarker of environmental and industrial pollution.

Erythrocyte glutathione transferase is a well-known biomarker of environmental pollution. Examination of the extensive scientific literature discovers an atypical and very interesting property of this enzyme which may reveal a chronic exposition to many contaminants but in some cases even an acute and short-term dangerous contamination. This review also underlines the peculiar molecular and kinetic properties of this enzyme which makes it unique in the panorama of enzymes used as biomarker for environmental contamination.

Analysis of Clinical and Laboratory Risk Factors of Post-Traumatic Intracranial Hemorrhage in Patients on Direct Oral Anticoagulants with Mild Traumatic Brain Injury: An Observational Multicenter Cohort.

BACKGROUND: Assessing the risk of intracranial hemorrhage (ICH) in patients with a mild traumatic brain injury (MTBI) who are taking direct oral anticoagulants (DOACs) is challenging. Currently, extensive use of computed tomography (CT) is routine in the emergency department (ED). OBJECTIVE: This study aims to investigate whether the clinical and laboratory characteristics presented at the ED evaluation can also estimate the risk of post-traumatic ICH in DOAC-treated patients with MTBI. METHODS: A retrospective observational study was conducted in three EDs in Italy from January 1, 2016 to March 15, 2020. All patients treated with DOACs who were evaluated for an MTBI in the ED were enrolled. The primary outcome of the study was the presence of post-traumatic ICH in the head CT performed in the ED. RESULTS: Of 930 patients on DOACs with MTBI who were enrolled, 6.8% (63 of 930) had a post-traumatic ICH and 1.5% (14 of 930) were treated with surgery or died as a result of the ICH. None of the laboratory factors were associated with an increased risk of ICH. On multivariate analysis, previous neurosurgical intervention, major trauma dynamic, post-traumatic loss of consciousness, post-traumatic amnesia, Glasgow Coma Scale score of 14, and evidence of trauma above the clavicles were associated with a higher risk of post-traumatic ICH. The net clinical benefit provided by risk factor assessment appears superior to the strategy of performing CT on all DOAC-treated patients. CONCLUSIONS: Assessment of the clinical characteristics presented at ED admission can help identify DOAC-treated patients with MTBI who are at risk of ICH.

Changes in emergency psychiatric consultations in time of COVID-19: a retrospective observational study in the Verona Academic Hospital over the two pandemic years 2020-2021.

BACKGROUND: During the first months of the COVID-19 pandemic, local health authorities in most Italian regions prescribed a reduction of ordinary outpatient and community mental health care. The aim of this study was to assess the impact of the COVID-19 pandemic on access to the emergency departments (ED) for psychiatric consultation in the pandemic years 2020 and 2021 compared to 2019. METHODS: This is a retrospective study conducted by using routinely collected administrative data of the two EDs of the Verona Academic Hospital Trust (Verona, Italy). All ED psychiatry consultations registered from 01.01.2020 to 31.12.2021 were compared with those registered in the pre-pandemic year (01.01.2019 to 31.12.2019). The association between each recorded characteristic and the year considered was estimated by chi-square or Fisher's exact test. RESULTS: A significant reduction was observed between 2020 and 2019 (-23.3%) and between 2021 and 2019 (-16.3%). This reduction was most evident in the lockdown period of 2020 (-40.3%) and in the phase corresponding to the second and third pandemic waves (-36.1%). In 2021, young adults and people with diagnosis of psychosis showed an increase in requests for psychiatric consultation. CONCLUSIONS: Fear of contagion may have been an important factor in the overall reduction in psychiatric consultations. However, psychiatric consultations for people with psychosis and for young adults increased. This finding underlines the need for mental health services to implement alternative outreach strategies aimed to support, in times of crisis, these vulnerable segments of the population.

Multi-centric study for development and validation of a CT head rule for mild traumatic brain injury in direct oral anticoagulants: the HERO-M nomogram.

BACKGROUND: Nomograms are easy-to-handle clinical tools which can help in estimating the risk of adverse outcome in certain population. This multi-center study aims to create and validate a simple and usable clinical prediction nomogram for individual risk of post-traumatic Intracranial Hemorrhage (ICH) after Mild Traumatic Brain Injury (MTBI) in patients treated with Direct Oral Anticoagulants (DOACs). METHODS: From January 1, 2016 to December 31, 2019, all patients on DOACs evaluated for an MTBI in five Italian Emergency Departments were enrolled. A training set to develop the nomogram and a test set for validation were identified. The predictive ability of the nomogram was assessed using AUROC, calibration plot, and decision curve analysis. RESULTS: Of the 1425 patients in DOACs in the study cohort, 934 (65.5%) were included in the training set and 491 (34.5%) in the test set. Overall, the rate of post-traumatic ICH was 6.9% (7.0% training and 6.9% test set). In a multivariate analysis, major trauma dynamic (OR: 2.73, p = 0.016), post-traumatic loss of consciousness (OR: 3.78, p = 0.001), post-traumatic amnesia (OR: 4.15, p < 0.001), GCS < 15 (OR: 3.00, p < 0.001), visible trauma above the clavicles (OR: 3. 44, p < 0.001), a post-traumatic headache (OR: 2.71, p = 0.032), a previous history of neurosurgery (OR: 7.40, p < 0.001), and post-traumatic vomiting (OR: 3.94, p = 0.008) were independent risk factors for ICH. The nomogram demonstrated a good ability to predict the risk of ICH (AUROC: 0.803; CI95% 0.721-0.884), and its clinical application showed a net clinical benefit always superior to performing CT on all patients. CONCLUSION: The Hemorrhage Estimate Risk in Oral anticoagulation for Mild head trauma (HERO-M) nomogram was able to predict post-traumatic ICH and can be easily applied in the Emergency Department (ED).

Risk of delayed intracranial haemorrhage after an initial negative CT in patients on DOACs with mild traumatic brain injury.

BACKGROUND: Repeat head CT in patients on direct oral anticoagulant therapy (DOACs) with minor traumatic brain injury (MTBI) after an initial CT scan without injury on arrival in the Emergency Department (ED) is a common clinical practice but is not based on clear evidence. AIM: To assess the incidence of delayed intracranial haemorrhage (ICH) in patients taking DOACs after an initial negative CT and the association of clinical and risk factors presented on patient arrival in the ED. METHODS: This retrospective multicentre observational study considered patients taking DOACs undergoing repeat CT after a first CT free of injury for the exclusion of delayed ICH after MTBI. Timing between trauma and first CT in the ED and pre- or post-trauma risk factors were analysed to assess a possible association with the risk of delayed ICH. RESULTS: A total of 1426 patients taking DOACs were evaluated in the ED for an MTBI. Of these, 68.3% (916/1426) underwent a repeat CT after an initial negative CT and 24 h of observation, with a rate of delayed ICH of 1.5% (14/916). Risk factors associated with the presence of a delayed ICH were post-traumatic loss of consciousness, post-traumatic amnesia and the presence of a risk factor when the patient presented to the ED within 8 h of the trauma. None of the patients with delayed ICH at 24-h repeat CT required neurosurgery or died within 30 days. CONCLUSIONS: Delayed ICH is an uncommon event at the 24-h control CT and does not affect patient outcome. Studying the timing and characteristics of the trauma may indicate patients who may benefit from more in-depth management.

"Decision tree analysis for assessing the risk of post-traumatic haemorrhage after mild traumatic brain injury in patients on oral anticoagulant therapy".

BACKGROUND: The presence of oral anticoagulant therapy (OAT) alone, regardless of patient condition, is an indication for CT imaging in patients with mild traumatic brain injury (MTBI). Currently, no specific clinical decision rules are available for OAT patients. The aim of the study was to identify which clinical risk factors easily identifiable at first ED evaluation may be associated with an increased risk of post-traumatic intracranial haemorrhage (ICH) in OAT patients who suffered an MTBI. METHODS: Three thousand fifty-four patients in OAT with MTBI from four Italian centers were retrospectively considered. A decision tree analysis using the classification and regression tree (CART) method was conducted to evaluate both the pre- and post-traumatic clinical risk factors most associated with the presence of post-traumatic ICH after MTBI and their possible role in determining the patient's risk. The decision tree analysis used all clinical risk factors identified at the first ED evaluation as input predictor variables. RESULTS: ICH following MTBI was present in 9.5% of patients (290/3054). The CART model created a decision tree using 5 risk factors, post-traumatic amnesia, post-traumatic transitory loss of consciousness, greater trauma dynamic, GCS less than 15, evidence of trauma above the clavicles, capable of stratifying patients into different increasing levels of ICH risk (from 2.5 to 61.4%). The absence of concussion and neurological alteration at admission appears to significantly reduce the possible presence of ICH. CONCLUSIONS: The machine-learning-based CART model identified distinct prognostic groups of patients with distinct outcomes according to on clinical risk factors. Decision trees can be useful as guidance in patient selection and risk stratification of patients in OAT with MTBI.

The Anfinsen Dogma: Intriguing Details Sixty-Five Years Later.

The pioneering experiments of Anfinsen on the oxidative folding of RNase have been revisited discovering some details, which update the statement of his dogma and shed new light on the leading role of the correct disulfide in the attainment of the native structure. CD analysis, mass spectrometry, fluorescence spectroscopy and enzyme activity indicate that native disulfides drive the formation of the secondary and tertiary structures that cannot be entirely formed in their absence. This opposes a common opinion that these structures are first formed and then stabilized by the native disulfides. Our results also indicate that a spontaneous re-oxidation of a reduced RNase cannot produce a complete recovery of activity, as described by many textbooks; this can be obtained only in the presence of a reshuffling solution such as GSH/GSSG.

The PSI Domain of the MET Oncogene Encodes a Functional Disulfide Isomerase Essential for the Maturation of the Receptor Precursor.

The tyrosine kinase receptor encoded by the MET oncogene has been extensively studied. Surprisingly, one extracellular domain, PSI, evolutionary conserved between plexins, semaphorins, and integrins, has no established function. The MET PSI sequence contains two CXXC motifs, usually found in protein disulfide isomerases (PDI). Using a scrambled oxidized RNAse enzymatic activity assay in vitro, we show, for the first time, that the MET extracellular domain displays disulfide isomerase activity, abolished by PSI domain antibodies. PSI domain deletion or mutations of CXXC sites to AXXA or SXXS result in a significant impairment of the cleavage of the MET 175 kDa precursor protein, abolishing the maturation of α and ß chains, of, respectively, 50 kDa and 145 kDa, disulfide-linked. The uncleaved precursor is stuck in the Golgi apparatus and, interestingly, is constitutively phosphorylated. However, no signal transduction is observed as measured by AKT and MAPK phosphorylation. Consequently, biological responses to the MET ligand-hepatocyte growth factor (HGF)-such as growth and epithelial to mesenchymal transition, are hampered. These data show that the MET PSI domain is functional and is required for the maturation, surface expression, and biological functions of the MET oncogenic protein.

Decision tree analysis to predict the risk of intracranial haemorrhage after mild traumatic brain injury in patients taking DOACs.

BACKGROUND: Although the preliminary evidence seems to confirm a lower incidence of post-traumatic bleeding in patients treated with direct oral anticoagulants (DOACs) compared to those on vitamin K antagonists (VKAs), the recommended management of mild traumatic brain injury (MTBI) in patients on DOACs is the same as those on the older VKAs, risking excessive use of CT in the emergency department (ED). AIM: To determine which easily identifiable clinical risk factors at the first medical evaluation in the ED may indicate an increased risk of post-traumatic intracranial haemorrhage (ICH) in patients on DOACs with MTBI. METHODS: Patients on DOACs who were evaluated in the ED for an MTBI from 2016 to 2020 at four centres in Northern Italy were considered. A decision tree analysis using the chi-square automatic interaction detection (CHAID) method was conducted to assess the risk of post-traumatic ICH after an MTBI. Known pre- and post-traumatic clinical risk factors that are easily identifiable at the first medical evaluation in the ED were used as input predictor variables. RESULTS: Among the 1146 patients on DOACs in this study, post-traumatic ICH was present in 6.5% (75/1146). Decision tree analysis using the CHAID method found post-traumatic TLOC, post-traumatic amnesia, major trauma dynamic, previous neurosurgery and evidence of trauma above the clavicles to be the strongest predictors associated with the presence of post-traumatic ICH in patients on DOACs. The absence of a concussion seems to indicate subgroups at very low risk of requiring neurosurgery. CONCLUSIONS: The machine-based CHAID model identified distinct prognostic groups of patients with distinct outcomes based on clinical factors. Decision trees can be useful as guides for patient selection and risk stratification.

Risk factors associated with intracranial bleeding and neurosurgery in patients with mild traumatic brain injury who are receiving direct oral anticoagulants.

BACKGROUND: The established clinical risk factors for post-traumatic intracranial bleeding have not been evaluated in patients receiving DOACs yet. AIM: Evaluating the association between clinic and patient characteristics and post-traumatic intracranial bleeding (ICH) in patients with mild traumatic brain injury (MTBI) and DOACs. METHODS: This is a retrospective observational study conducted on three Emergency Departments. Multivariate analysis provided association in terms of OR with the risk of ICH. The performance of the multivariate model, described in a nomogram, has been tested with discrimination and decision curve analysis. RESULTS: Of 473 DOACs patients with MTBI, 8.5% had post-traumatic ICH. On multivariable analysis, major dynamics (odds ratio [OR] 6.255), post-traumatic amnesia (OR 3.961), post-traumatic loss of consciousness (LOC, OR 7.353), Glasgow Coma Scale (GCS) score < 15 (OR 3.315), post-traumatic headache (OR 4.168) and visible trauma above the clavicles (OR 3.378) were associated with a higher likelihood of ICH. The multivariate model, used for the nomogram construction, showed a good performance (AUC bias corrected with 5000 bootstraps resample 0.78). The DCAs showed a net clinical benefit of the prognostic model. CONCLUSIONS: Clinical risk factors can be used in DOACs patients to better define the risk of post-traumatic ICH.

Oxidative Folding of Proteins: The "Smoking Gun" of Glutathione.

Glutathione has long been suspected to be the primary low molecular weight compound present in all cells promoting the oxidative protein folding, but twenty years ago it was found "not guilty". Now, new surprising evidence repeats its request to be the "smoking gun" which reopens the criminal trial revealing the crucial involvement of this tripeptide.

New Factors Enhancing the Reactivity of Cysteines in Molten Globule-Like Structures.

Protein cysteines often play crucial functional and structural roles, so they are emerging targets to design covalent thiol ligands that are able to modulate enzyme or protein functions. Some of these residues, especially those involved in enzyme mechanisms-including nucleophilic and reductive catalysis and thiol-disulfide exchange-display unusual hyper-reactivity; such a property is expected to result from a low pKa and from a great accessibility to a given reagent. New findings and previous evidence clearly indicate that pKa perturbations can only produce two-four-times increased reactivity at physiological pH values, far from the hundred and even thousand-times kinetic enhancements observed for some protein cysteines. The data from the molten globule-like structures of ribonuclease, lysozyme, bovine serum albumin and chymotrypsinogen identified new speeding agents, i.e., hydrophobic/electrostatic interactions and productive complex formations involving the protein and thiol reagent, which were able to confer exceptional reactivity to structural cysteines which were only intended to form disulfides. This study, for the first time, evaluates quantitatively the different contributions of pKa and other factors to the overall reactivity. These findings may help to clarify the mechanisms that allow a rapid disulfide formation during the oxidative folding of many proteins.

Direct Oral Anticoagulant Treatment and Mild Traumatic Brain Injury: Risk of Early and Delayed Bleeding and the Severity of Injuries Compared with Vitamin K Antagonists.

BACKGROUND: The risk of intracranial hemorrhage (ICH) in patients taking direct oral anticoagulants (DOACs) after mild traumatic brain injury (MTBI) is unclear. OBJECTIVES: To assess the differences in the risk of developing early, delayed, and comprehensive bleeding after MTBI among patients treated with DOACs as compared with those treated with vitamin K antagonists (VKAs). METHODS: All MTBI patients taking oral anticoagulants in our emergency department between June 2017 and August 2018 were included. All patients on oral anticoagulants underwent immediate cerebral computed tomography (CT) and a second CT scan after 24 h of clinical observation. RESULTS: There were 451 patients enrolled: 268 were on VKAs and 183 on DOACs. Of the DOAC-treated patients, 7.7% (14/183) presented overall intracranial bleeding, compared with 14.9% (40/268) of VKA-treated patients (p = 0.026). Early bleeding was present in 5.5% (10/183) of DOAC-treated patients and in 11.6% (31/268) of VKA-treated patients (p = 0.030). Multivariable analysis showed that VKA therapy (odds ratio [OR] 2.327), high-energy impact (OR 11.229), amnesia (OR 2.814), loss of consciousness (OR 5.286), Glasgow Coma Scale score < 15 (OR 4.719), and the presence of lesion above the clavicles (OR 2.742) were associated with significantly higher risk of global ICH. A nomogram was constructed to predict ICH using these six variables. Discrimination of the nomogram revealed good predictive abilities (area under the receiver operating characteristic curve: 0.817). CONCLUSIONS: DOAC-treated patients seem to have lower risk of posttraumatic intracranial bleeding compared with VKA-treated patients.

Ultra-Rapid Glutathionylation of Ribonuclease: Is this the Real Incipit of its Oxidative Folding?

Many details of oxidative folding of proteins remain obscure, in particular, the role of oxidized glutathione (GSSG). This study reveals some unknown aspects. When a reduced ribonuclease A refolds in the presence of GSSG, most of its eight cysteines accomplish a very fast glutathionylation. In particular, one single cysteine, identified as Cys95 by mass spectrometry, displays 3600 times higher reactivity when compared with an unperturbed protein cysteine. Furthermore, the other five cysteines show 40-50 times higher reactivity toward GSSG. This phenomenon is partially due to a low pKa value of most of these cysteines (average pKa = 7.9), but the occurrence of a reversible GSSG-ribonuclease complex (KD = 0.12 mM) is reasonably responsible for the extraordinary hyper-reactivity of Cys95. Neither hyper-reactivity nor some protein-disulfide complexes have been found by reacting a reduced ribonuclease with other natural disulfides i.e., cystine, cystamine, and homocystine. Hyper-reactivity of all cysteines was observed toward 5,5'-dithiobis-(2-nitrobenzoic acid). Given that GSSG is present in high concentrations in the endoplasmic reticulum, this property may shed light on the early step of its oxidative folding. The ultra-rapid glutathionylation of cysteines, only devoted to form disulfides, is a novel property of the molten globule status of the ribonuclease.

Association between short- and medium-term air pollution exposure and risk of mortality after intravenous thrombolysis for stroke.

The exposure to air pollutants may increase both incidence and mortality of stroke. We aimed to investigate the association of short- and medium-term exposure to particulate matter (PM) and nitrogen dioxide (NO2) with the outcome of intravenous thrombolysis (IVT) for stroke. We conducted a retrospective analysis based on data prospectively collected from 944 consecutive IVT-treated stroke patients. The main outcome measure was 3-month mortality. The secondary outcome measures were causes of neurological deterioration (≥ 1 NIHSS point from baseline or death < 7 days), including intracerebral hemorrhage, cerebral edema (CED), and persistence or new appearance of hyperdense cerebral artery sign. In the adjusted model, higher PM2.5 and PM10 values in the last 3 days and 4 weeks before stroke were independently associated with higher mortality rate [hazard ratio (HR) 1.014, 95% confidence intervals (CI) 1.005-1.024, p = 0.003; HR 1.079, 95% CI 1.055-1.103, p = 0.001; HR 1.019, 95% CI 1.005-1.032, p = 0.008; and HR 1.015, 95% CI 1.004-1.027, p = 0.007; respectively]. Higher PM2.5 and PM10 values in the last 4 weeks were associated with higher CED rate [odd ratio (OR) 1.023, 95% CI 1.007-1.040, p = 0.006; and OR 1.017, 95% CI 1.003-1.032, p = 0.021; respectively]. No significant association between PM or NO2 and other causes of neurological deterioration was observed. Higher exposure to PM in the last 3 days and 4 weeks before stroke may be independently associated with 3-month mortality after IVT. Higher exposure to PM in the last 4 weeks before stroke may also be independently associated with CED after IVT.

Paraoxonase, arylesterase and lactonase activities of paraoxonase-1 (PON1) in obese and severely obese women.

Obesity is independently associated with disturbances in lipid and lipoprotein metabolism, oxidative stress, and is a well-established independent risk factor for cardiovascular diseases (CVD). Human paraoxonase 1 (PON1) is a pleotropic high-density lipoprotein (HDL)-associated enzyme with antioxidant and anti-inflammatory proprieties that have been suggested to contribute to the athero-protective function of the lipoprotein. The aim of this study was to investigate whether obesity is associated with PON1 activity and whether this association is influenced by oxidative stress, inflammation and HDL cholesterol (HDL-C) concentration. The promiscuous activities, arylesterase and paraoxonase, and the putative physiological activity, lactonase, of PON1 were assessed in the serum of 214 obese and severely obese, 101 overweight and 129 normal-weight women. Levels of high-sensitivity C-reactive protein (hs-CRP), hydroperoxides (by-products of lipid oxidative damage) and lipid profiles were also evaluated. Arylesterase activity was the only activity that significantly differed across the groups (ANOVA, p < .01), with the greatest decrease observed in individuals with body mass index (BMI) > 40 kg/m2 compared to controls (p < .001). This activity was also inversely, although weakly (r = -0.160, p < .001) correlated with the BMI, and the association was independent of age and levels of oxidative stress and inflammation, but not of HDL-C concentration. In conclusion, our results suggest that the apparent obesity-associated decrement of PON1 activity might simply reflect the decrease in concentration of its plasmatic carrier.

Association of Short- and Medium-Term Particulate Matter Exposure with Risk of Mortality after Spontaneous Intracerebral Hemorrhage.

OBJECTIVE: We investigated the association of short- and medium-term particulate matter (PM) exposure with risk of mortality in patients with spontaneous intracerebral hemorrhage (ICH) identified according to strict etiologic criteria. METHODS: We conducted a retrospective analysis of prospectively collected data from consecutive patients with spontaneous ICH admitted to the emergency department of the University Hospital of Verona from March 2011 to December 2014. Outcome measures were mortality within 1 month after ICH and significant hematoma expansion (HE) defined as an absolute growth of more than 12.5 mL or a relative increase of more than 50% from baseline to follow-up computed tomography scan. RESULTS: A final number of 308 patients were included. In the adjusted model, higher PM2.5 and PM10 values in the last 3 days (odds ratio [OR] 1.827, 95% confidence interval [CI] 1.057-3.159, P = .031 and OR 1.949, 95% CI 1.025-3.704, P = .042, respectively) and in the last 4 weeks (OR 4.975, 95% CI 2.174-11.381, P < .001 and OR 9.781, 95% CI 3.425-27.932, P < .001, respectively) before ICH were associated with higher mortality rate. No association was found between PM exposure and significant HE. CONCLUSIONS: PM exposure in the short- and medium-term before spontaneous ICH was associated with risk of 1-month mortality, independent of predictors such as age, sex, stroke severity, intraventricular hemorrhage, ICH volume, ICH location, ICH etiologic subtype, significant HE, antithrombotic therapy, atrial fibrillation, and blood glucose levels.

Evolution of Negative Cooperativity in Glutathione Transferase Enabled Preservation of Enzyme Function.

Negative cooperativity in enzyme reactions, in which the first event makes subsequent events less favorable, is sometimes well understood at the molecular level, but its physiological role has often been obscure. Negative cooperativity occurs in human glutathione transferase (GST) GSTP1-1 when it binds and neutralizes a toxic nitric oxide adduct, the dinitrosyl-diglutathionyl iron complex (DNDGIC). However, the generality of this behavior across the divergent GST family and its evolutionary significance were unclear. To investigate, we studied 16 different GSTs, revealing that negative cooperativity is present only in more recently evolved GSTs, indicating evolutionary drift in this direction. In some variants, Hill coefficients were close to 0.5, the highest degree of negative cooperativity commonly observed (although smaller values of nH are theoretically possible). As DNDGIC is also a strong inhibitor of GSTs, we suggest negative cooperativity might have evolved to maintain a residual conjugating activity of GST against toxins even in the presence of high DNDGIC concentrations. Interestingly, two human isoenzymes that play a special protective role, safeguarding DNA from DNDGIC, display a classical half-of-the-sites interaction. Analysis of GST structures identified elements that could play a role in negative cooperativity in GSTs. Beside the well known lock-and-key and clasp motifs, other alternative structural interactions between subunits may be proposed for a few GSTs. Taken together, our findings suggest the evolution of self-preservation of enzyme function as a novel facility emerging from negative cooperativity.

Red Blood Cell Distribution Width Is an Independent Predictor of Outcome in Patients Undergoing Thrombolysis for Ischemic Stroke.

An appropriate and timely management, including early diagnosis and accurate prognostication, is the mainstay for managed care of patients with acute ischemic stroke. Since red blood cell distribution width (RDW) was found to be an independent predictor of clinical outcomes in patients with thrombotic disorders, we designed a retrospective observational study to investigate whether the RDW value may also retain predictive significance in stoke patients undergoing thrombolytic therapy. This retrospective study was based on all patients admitted to the Emergency Department (ED) of the University Hospital of Verona (Italy) with a diagnosis of ischemic stroke, who underwent systemic thrombolysis between January 2013 and June 2015. The RDW value along with basal clinical characteristics was recorded at ED admission. The final study population consisted of 316 patients. A significant association was found between stroke severity (NIHSS score) and RDW (r = 0.322; p < 0.001). The median RDW value in patients with clinical improvement after thrombolysis was significantly lower than in patients without (13.4 vs. 14.1%; p < 0.001). The diagnostic accuracy (area under the curve) of RDW for predicting the lack of neurological improvement was 0.667. In univariate analysis, RDW >14.5% was associated with increased rate of no neurological improvement (odds ratio [OR], 2.38; 95% confidence interval [CI], 1.37-4.13), an association remaining significant also in multivariate analysis (OR, 1.85; 95% CI, 1.13-3.32). Survivor curve analysis showed that patients with RDW values ≥14.5% had a higher risk of 1-year mortality and shorter survival. These results suggest that RDW assessment at ED admission may provide valuable diagnostic and prognostic information in patients with acute ischemic stroke.