Site-directed mutagenesis reveals the interplay between stability, structure, and enzymatic activity in RidA from Capra hircus.

Reactive intermediate deaminase A (RidA) is a highly conserved enzyme that catalyzes the hydrolysis of 2-imino acids to the corresponding 2-keto acids and ammonia. RidA thus prevents the accumulation of such potentially harmful compounds in the cell, as exemplified by its role in the degradation of 2-aminoacrylate, formed during the metabolism of cysteine and serine, catalyzing the conversion of its stable 2-iminopyruvate tautomer into pyruvate. Capra hircus (goat) RidA (ChRidA) was the first mammalian RidA to be isolated and described. It has the typical homotrimeric fold of the Rid superfamily, characterized by remarkably high thermal stability, with three active sites located at the interface between adjacent subunits. ChRidA exhibits a broad substrate specificity with a preference for 2-iminopyruvate and other 2-imino acids derived from amino acids with non-polar non-bulky side chains. Here we report a biophysical and biochemical characterization of eight ChRidA variants obtained by site-directed mutagenesis to gain insight into the role of specific residues in protein stability and catalytic activity. Each mutant was produced in Escherichia coli cells, purified and characterized in terms of quaternary structure, thermal stability and substrate specificity. The results are rationalized in the context of the high-resolution structures obtained by x-ray crystallography.

Brachial Tunneled Peripherally Inserted Central Catheters and the Risk of Catheter Complications: A Systematic Review and Meta-Analysis.

INTRODUCTION: Situations involving increased workloads and stress (i.e., the COVID-19 pandemic) underline the need for healthcare professionals to minimize patient complications. In the field of vascular access, tunneling techniques are a possible solution. This systematic review and meta-analysis aimed to compare the effectiveness of tunneled Peripherally Inserted Central Catheters (tPICCs) to conventional Peripherally Inserted Central Catheters (cPICCs) in terms of bleeding, overall success, procedural time, and late complications. METHODS: Randomized controlled trials without language restrictions were searched using PUBMED®, EMBASE®, EBSCO®, CINAHL®, and the Cochrane Controlled Clinical Trials Register from August 2022 to August 2023. Five relevant papers (1238 patients) were included. RESULTS: There were no significant differences in overall success and nerve or artery injuries between the two groups (p = 0.62 and p = 0.62, respectively), although cPICCs caused slightly less bleeding (0.23 mL) and had shorter procedural times (2.95 min). On the other hand, tPICCs had a significantly reduced risk of overall complications (p < 0.001; RR0.41 [0.31-0.54] CI 95%), catheter-related thrombosis (p < 0.001; RR0.35 [0.20-0.59] IC 95%), infection-triggering catheter removal (p < 0.001; RR0.33 [0.18-0.61] IC 95%), wound oozing (p < 0.001; RR0.49 [0.37-0.64] IC 95%), and dislodgement (p < 0.001; RR0.4 [0.31-0.54] CI 95%). CONCLUSIONS: The tunneling technique for brachial access appears to be safe concerning intra-procedural bleeding, overall success, and procedural time, and it is effective in reducing the risk of late complications associated with catheterization.

Integrated short peripheral intravenous cannulas and risk of catheter failure: A systematic review and meta-analysis.

BACKGROUND: Short peripheral catheters (SPCs) are used to provide intravenous therapies in hospitalized patients. Recently, the category of SPC has become more complex, with the introduction in clinical practice of "integrated" SPCs (ISPCs), renewed regarding the material (polyurethane rather than polytetrafluoroethylene) and design (large wing; pre-assembled extension; preassembled needle-free connector (NFC)). METHODS: This systematic review and meta-analysis aimed to analyze randomized controlled trials (RCTs) and quasi-randomized studies in hospitalized patients, analyzing the risk of overall catheter failure as well as the risk of each type of complication (occlusion, infiltration, thrombophlebitis, and dislodgement) for ISPCs compared to non-integrated SPCs. These systematic review and meta-analysis were registered on PROSPERO (CRD42022322970). DATA SOURCES: We searched PUBMED®, EMBASE®, and the Cochrane Controlled Clinical Trials register from April to November 2022. RESULTS: INCLUDED STUDIES: The research identified 1260 articles. After the abstract review, 13 studies were included for full manuscript review and, after that, six papers (4727 patients) were included in the meta-analysis. DESCRIPTION OF THE EFFECT: We found a significantly reduced risk of catheter failure (pooling all complications) for ISPCs compared to SPCs (p = 0.002 RR 0.65; 95% CI 0.63-0.9). A significant reduction in the risks of occlusion (p = 0.007 RR 0.72; 95% CI 0.56-0.92) was observed. As regards the risk of infiltration, thrombophlebitis, and dislodgement, the analysis showed a trend in favor of ISPCs, though not statistically significant (respectively p = 0.2 RR 0.84; 95% CI 0.64-1.1; p = 0.25 RR 0.91; 95% CI 0.78-1.07; p = 0.06 RR 0.72; 95% CI 0.52-1.01). CONCLUSIONS: ISPCs significantly reduce the risks of catheter failure (overall complications) and occlusion. More RCTs are needed to understand if the preassembled ISPC is better than the composted closed system (non-integrated SPC + extension line + NFC).

Safety of mid-thigh exit site venous catheters in multidrug resistant colonized patients.

INTRODUCTION: Venous catheters inserted in superficial femoral vein and with mid-thigh exit site have emerged as a feasible and safe technique for central or peripheral tip's venous access, especially in agitated, delirious patients. The spread of multidrug-resistant bacterial (MDR) strains is an emerging clinical problem and more and more patients are being colonized by these types of bacteria. The aim of this study is to evaluate the incidence of central line associated bloodstream infections (CLABSI) or catheter related bloodstream infections (CRBSI) in mid-thigh catheters in patients with positive rectal swabs to evaluate the safety of this procedure and the real infection risk. METHODS: In this retrospective observational study, we analyzed data on patients with mid-tight catheters inserted from May 2021 to November 2022. All surveillance rectal swabs were recorded. In addition, to collect data on CLABSI and CRBSI, the results of all blood and catheter tip cultures performed during the hospital stay were acquired. RESULTS: Six hundred two patients were enrolled, 304 patients (50.5%) had a rectal swab; 128 (42.1%) swabs were positive for MDR. Nine CLABSI (only two in patients with a positive rectal swab) and three CRBSI were detected. No statistical difference in the absolute number of CLABSI and CRBSI and in the number of infections per 1000 catheter days emerged between the overall population and patients with positive rectal swabs (respectively p = 0.45 and p = 0.53). Similarly, no statistical difference in the number of CLABSI and CRBSI was found among patients with a negative swab and patients with a positive one (respectively p = 0.43 and p = 0.51). CONCLUSIONS: According to our data, cannulation of the superficial femoral vein represents a safe location in patients with positive rectal swabs.

A decision-making algorithm proposal for PICCs and midlines insertion in patients with advanced kidney disease: A pilot study.

INTRODUCTION: Kidney Disease Outcomes Quality Initiative clinical practice guidelines recommend avoiding placement of peripherally inserted vascular access devices in patients with an estimated glomerular filtration rate (eGFR) <45 ml/min. On the other hand, many patients with severe chronic kidney disease (CKD) have poor prognosis.This study carried out a global assessment of mortality at 2 years through Charlson Comorbidity Index (CCI) and Beclap score in patients with PICCs or Midlines, assuming that in those with an estimated high mortality rate at 2 years, it could be acceptable to implant a peripheral vascular access device (PVAD) despite the presence of CKD. METHODS: We analyzed data on patients with PICCs or Midlines inserted from October 2018 to November 2019. CCI, Beclap score, and eGFR were calculated for each patient at the time of the catheter insertion. We then followed patients for 2 years to assess 2-year mortality for each. RESULTS: One hundred and thirty-one patients were enrolled, 49 (37.4%) had eGFR<45 ml. The 2-year mortality rate was 57.3%. The cut off derived from ROC curve analysis of 15 for Beclap score and 5 for CCI, showed good sensitivity and specificity in predicting mortality of the total population, patients without an oncological disease and patients with eGFR<45 ml/min. CONCLUSION: CCI and Beclap score are good predictors of mortality at 2 years.Physicians and nurses can use these tools in the evaluation of patients at risk for future dialysis, instead of relying exclusively on renal function to decide whether implanting PICCs, Midlines, or other vascular access devices.

Remdesivir-induced bradycardia in patients hospitalized with SARS-CoV2 infection: a possible vagally-mediated mechanism.

Recently, case series studies on patients with SARS-CoV-2 infection reported an association between remdesivir (RDV) administration and incidental bradycardia. However, the phenomenon has not yet been described in detail. We conducted a retrospective case-control study to evaluate the occurrence of RDV-related bradycardia in patients hospitalized for SARS-CoV2 pneumoniae. We retrospectively evaluated 71 patients, hospitalized in six internal medicine wards of the Milan area, affected by mild-to-moderate COVID-19 who received RDV (RDV group) and 54 controls, matched for sex, age and disease severity on admission (CTR group). The mean heart rate value recorded during the first two days of hospitalization was considered as baseline heart rate (HRb). Heart rate values relative to the 5-days treatment and the 5-days post-treatment were extracted for RDV group, while heart rate values relative to 10 days of hospitalization were considered for the CTR group. ΔHR values were calculated as maximum HR drop versus HRb. Possible associations between ΔHR and clinical-demographic factors were assessed through regression analysis. The RDV group experienced a significantly higher incidence of bradycardia compared to the CTR group (56% vs 33%, OR 2.6, 95% CI 1.2-5.4, p value = 0.011). Moreover, the RDV group showed higher ΔHR values than the CTR group. The HR progressively decreased with daily administration of RDV, reaching the maximun drop on day six (-8.6±1.9 bpm). In RDV group, patients who experienced bradycardia had higher drop in HR, higher alanine aminotransferase (ALT) values at the baseline (bALT) and during the RDV administration period. ΔHR was positively associated with HRb (ß = 0.772, p < 0.001) and bALT (ß = 0.245, p = 0.005). In conclusion, our results confirmed a significant association between RDV administration and development of bradycardia. This effect was proportional to baseline HR and was associated with higher levels of baseline ALT, suggesting a possible interaction between RDV liver metabolism and a vagally-mediated effect on HR due to increased availability of RDV metabolites.

Benchmark dataset of memes with text transcriptions for automatic detection of multi-modal misogynistic content.

In this paper we present a benchmark dataset generated as part of a project for automatic identification of misogyny within online content, which focuses in particular on memes. The benchmark here described is composed of 800 memes collected from the most popular social media platforms, such as Facebook, Twitter, Instagram and Reddit, and consulting websites dedicated to collection and creation of memes. To gather misogynistic memes, specific keywords that refer to misogynistic content have been considered as search criterion, considering different manifestations of hatred against women, such as body shaming, stereotyping, objectification and violence. In parallel, memes with no misogynist content have been manually downloaded from the same web sources. Among all the collected memes, three domain experts have selected a dataset of 800 memes equally balanced between misogynistic and non-misogynistic ones. This dataset has been validated through a crowdsourcing platform, involving 60 subjects for the labelling process, in order to collect three evaluations for each instance. Two further binary labels have been collected from both the experts and the crowdsourcing platform, for memes evaluated as misogynistic, concerning aggressiveness and irony. Finally for each meme, the text has been manually transcribed. The dataset provided is thus composed of the 800 memes, the labels given by the experts and those obtained by the crowdsourcing validation, and the transcribed texts. This data can be used to approach the problem of automatic detection of misogynistic content on the Web relying on both textual and visual cues, facing phenomenons that are growing every day such as cybersexism and technology-facilitated violence.

Apis mellifera RidA, a novel member of the canonical YigF/YER057c/UK114 imine deiminase superfamily of enzymes pre-empting metabolic damage.

The Reactive intermediate deiminase (Rid) protein family is a group of enzymes widely distributed in all Kingdoms of Life. RidA is one of the eight known Rid subfamilies, and its members act by preventing the accumulation of 2-aminoacrylate, a highly reactive enamine generated during the metabolism of some amino acids, by hydrolyzing the 2-iminopyruvate tautomer to pyruvate and ammonia. RidA members are homotrimers exhibiting a remarkable thermal stability. Recently, a novel subclass of RidA was identified in teleosts, which differs for stability and substrate specificity from the canonical RidA. In this study we structurally and functionally characterized RidA from Apis mellifera (AmRidA) as the first example of an invertebrate RidA to assess its belonging to the canonical RidA group, and to further correlate structural and functional features of this novel enzyme class. Circular dichroism revealed a spectrum typical of the RidA proteins and the high thermal stability. AmRidA exhibits the 2-imino acid hydrolase activity typical of RidA family members with a substrate specificity similar to that of the canonical RidA. The crystal structure confirmed the homotrimeric assembly and the presence of the typical structural features of RidA proteins, such as the proposed substrate recognition loop, and the ß-sheets ß1-ß9 and ß1-ß2. In conclusion, our data define AmRidA as a canonical member of the well-conserved RidA family and further clarify the diagnostic structural features of this class of enzymes.