Influence of Host Plants and Tending Ants on the Cuticular Hydrocarbon Profile of a Generalist Myrmecophilous Caterpillar.

In myrmecophilous organisms, which live in symbiosis with ants, cuticular hydrocarbons (CHCs) play a pivotal role in interspecific communication and defense against chemical-oriented predators. Although these interactions form complex information webs, little is known about the influence of biotic environmental factors on the CHC profiles of myrmecophiles. Here, we analyzed the effect of different host plants and tending ants on the larval CHC profile of Synargis calyce (Lepidoptera: Riodinidae), a polyphagous species with facultative myrmecophily. Groups of caterpillars were fed individually with three host plant species (without tending ants), and with two tending ant species. Through gas chromatography analysis, we compared the cuticular profiles of treatments and found a high similarity between plants and caterpillars (65-82%), but a low similarity between caterpillars and their tending ants (30 - 25%). Cluster analysis showed that caterpillars, ants, and plants form distinct groups, indicating that S. calyce caterpillars have their own chemical profile. These results are similar to those observed for Lycaenidae caterpillars indicating that there is functional convergence in the chemical strategies used by myrmecophilous caterpillar species with similar ecology. Also, the results suggest that the cuticular compounds of S. calyce are primarily influenced by their host plants rather than their tending ants. Thus, we propose that these caterpillars present a trade-off between camouflage and directly informing their presence to ants, maintaining their unique chemical profile, though slightly affected by biotic environmental factors.

Interplay between nitric oxide and inorganic nitrogen sources in root development and abiotic stress responses.

Nitrogen (N) is an essential nutrient for plants, and the sources from which it is obtained can differently affect their entire development as well as stress responses. Distinct inorganic N sources (nitrate and ammonium) can lead to fluctuations in the nitric oxide (NO) levels and thus interfere with nitric oxide (NO)-mediated responses. These could lead to changes in reactive oxygen species (ROS) homeostasis, hormone synthesis and signaling, and post-translational modifications of key proteins. As the consensus suggests that NO is primarily synthesized in the reductive pathways involving nitrate and nitrite reduction, it is expected that plants grown in a nitrate-enriched environment will produce more NO than those exposed to ammonium. Although the interplay between NO and different N sources in plants has been investigated, there are still many unanswered questions that require further elucidation. By building on previous knowledge regarding NO and N nutrition, this review expands the field by examining in more detail how NO responses are influenced by different N sources, focusing mainly on root development and abiotic stress responses.

Allosteric activation unveils protein-mass modulation of ATP phosphoribosyltransferase product release.

Heavy-isotope substitution into enzymes slows down bond vibrations and may alter transition-state barrier crossing probability if this is coupled to fast protein motions. ATP phosphoribosyltransferase from Acinetobacter baumannii is a multi-protein complex where the regulatory protein HisZ allosterically enhances catalysis by the catalytic protein HisGS. This is accompanied by a shift in rate-limiting step from chemistry to product release. Here we report that isotope-labelling of HisGS has no effect on the nonactivated reaction, which involves negative activation heat capacity, while HisZ-activated HisGS catalytic rate decreases in a strictly mass-dependent fashion across five different HisGS masses, at low temperatures. Surprisingly, the effect is not linked to the chemical step, but to fast motions governing product release in the activated enzyme. Disruption of a specific enzyme-product interaction abolishes the isotope effects. Results highlight how altered protein mass perturbs allosterically modulated thermal motions relevant to the catalytic cycle beyond the chemical step.

MetageNN: a memory-efficient neural network taxonomic classifier robust to sequencing errors and missing genomes.

BACKGROUND: With the rapid increase in throughput of long-read sequencing technologies, recent studies have explored their potential for taxonomic classification by using alignment-based approaches to reduce the impact of higher sequencing error rates. While alignment-based methods are generally slower, k-mer-based taxonomic classifiers can overcome this limitation, potentially at the expense of lower sensitivity for strains and species that are not in the database. RESULTS: We present MetageNN, a memory-efficient long-read taxonomic classifier that is robust to sequencing errors and missing genomes. MetageNN is a neural network model that uses short k-mer profiles of sequences to reduce the impact of distribution shifts on error-prone long reads. Benchmarking MetageNN against other machine learning approaches for taxonomic classification (GeNet) showed substantial improvements with long-read data (20% improvement in F1 score). By utilizing nanopore sequencing data, MetageNN exhibits improved sensitivity in situations where the reference database is incomplete. It surpasses the alignment-based MetaMaps and MEGAN-LR, as well as the k-mer-based Kraken2 tools, with improvements of 100%, 36%, and 23% respectively at the read-level analysis. Notably, at the community level, MetageNN consistently demonstrated higher sensitivities than the previously mentioned tools. Furthermore, MetageNN requires < 1/4th of the database storage used by Kraken2, MEGAN-LR and MMseqs2 and is > 7× faster than MetaMaps and GeNet and > 2× faster than MEGAN-LR and MMseqs2. CONCLUSION: This proof of concept work demonstrates the utility of machine-learning-based methods for taxonomic classification using long reads. MetageNN can be used on sequences not classified by conventional methods and offers an alternative approach for memory-efficient classifiers that can be optimized further.

Trehalose Improved 20-min Cycling Time-Trial Performance After 100-min Cycling in Amateur Cyclists.

Carbohydrate (CHO) supplementation during endurance exercise can improve performance. However, it is unclear whether low glycemic index (GI) CHO leads to differential ergogenic and metabolic effects compared with a standard high GI CHO. This study investigated the ergogenic and metabolic effects of CHO supplementation with distinct GIs, namely, (a) trehalose (30 g/hr), (b) isomaltulose (30 g/hr), (c) maltodextrin (60 g/hr), and (d) placebo (water). In this double-blind, crossover, counterbalanced, placebo-controlled study, 13 male cyclists cycled a total of 100 min at varied exercise intensity (i.e., 10-min stages at 1.5, 2.0, and 2.5 W/kg; repeated three times plus two 5-min stages at 1.0 W/kg before and after the protocol), followed by a 20-min time trial on four separated occasions. Blood glucose and lactate (every 20 min), heart rate, and ratings of perceived exertion were collected throughout, and muscle biopsies were taken before and immediately after exercise. The results showed that trehalose improved time-trial performance compared with placebo (total work done 302 ± 39 vs. 287 ± 48 kJ; p = .01), with no other differences between sessions (all p ≥ .07). Throughout the 100-min protocol, blood glucose was higher with maltodextrin compared with the other supplements at all time points (all p < .05). Heart rate, ratings of perceived exertion, muscle glycogen content, blood glucose, and lactate were not different between conditions when considering the 20-min time trial (all p > .05). Trehalose supplementation throughout endurance exercise improved cycling performance and appears to be an appropriate CHO source for exercise tasks up to 2 hr. No ergogenic superiority between the different types of CHO was established.

Impact of the COVID-19 Pandemic on the Outcomes of Patients Undergoing Oncological Surgeries: CORONAL Study.

BACKGROUND: The impact of coronavirus disease 2019 (COVID-19) on postoperative recovery from oncology surgeries should be understood for the clinical decision-making. Therefore, this study was designed to evaluate the postoperative cumulative 28-day mortality and the morbidity of surgical oncology patients during the COVID-19 pandemic. METHODS: This retrospective cohort study included patients consecutively admitted to intensive care units (ICU) of three centres for postoperative care of oncologic surgeries between March to June 2019 (first phase) and March to June 2020 (second phase). The primary outcome was cumulative 28-day postoperative mortality. Secondary outcomes were postoperative organic dysfunction and the incidence of clinical complications. Because of the possibility of imbalance between groups, adjusted analyses were performed: Cox proportional hazards model (primary outcome) and multiple logistic regression model (secondary outcomes). RESULTS: After screening 328 patients, 291 were included. The proportional hazard of cumulative 28-day mortality was higher in the second phase than that in the first phase in the Cox model, with the adjusted hazard ratio of 4.35 (95% confidence interval [CI] 2.15-8.82). The adjusted incidences of respiratory complications (odds ratio [OR] 5.35; 95% CI 1.42-20.11) and pulmonary infections (OR 1.53; 95% CI 1.08-2.17) were higher in the second phase. However, the adjusted incidence of other infections was lower in the second phase (OR 0.78; 95% CI 0.67-0.91). CONCLUSIONS: Surgical oncology patients who underwent postoperative care in the intensive care unit during the COVID-19 pandemic had higher hazard of 28-day mortality. Furthermore, these patients had higher odds of respiratory complications and pulmonary infections. Trials registration The study is registered in the Brazilian Registry of Clinical Trials under the code RBR-8ygjpqm, UTN code U1111-1293-5414.

Effects of aflibercept and bevacizumab on cell viability, cell metabolism and inflammation in hypoxic human Müller cells.

Anti-VEGF (vascular endothelial growth factor) drugs such as aflibercept (AFL) and bevacizumab (BVZ) inhibit pathological neo-angiogenesis and vascular permeability in retinal vascular diseases. As cytokines and growth factors are produced by Müller glial cells under stressful and pathological conditions, we evaluated the in vitro effect of AFL (Eylea®, 0.5 mg/mL) and BVZ (Avastin®, 0.5 mg/mL) on cell viability/metabolism, and cytokine/growth factor production by Müller cells (MIO-M1) under cobalt chloride (CoCl2)-induced hypoxia after 24h, 48h and 72h. Cell viability/metabolism were analyzed by Trypan Blue and MTT assays and cytokine/growth factors in supernatants by Luminex xMAP-based multiplex bead-based immunoassay. Cell viability increased with AFL at 48h and 72h and decreased with BVZ or hypoxia at 24h. BVZ-treated cells showed lower cell viability than AFL at all exposure times. Cell metabolism increased with AFL but decreased with BVZ (72h) and hypoxia (48h and72h). As expected, AFL and BVZ decreased VEGF levels. AFL increased PDGF-BB, IL-6 and TNF-α (24h) and BVZ increased PDGF-BB (72h). Hypoxia reduced IL-1ß, -6, -8, TNF-α and PDGF-BB at 24h, and its suppressive effect was more prominent than AFL (EGF, PDGF-BB, IL-1ß, IL-6, IL-8, and TNF-α) and BVZ (PDGF-BB and IL-6) effects. Hypoxia increased bFGF levels at 48h and 72h, even when combined with anti-VEGFs. However, the stimulatory effect of BVZ predominated over hypoxia for IL-8 and TNF-α (24h), as well as for IL-1ß (72h). Thus, AFL and BVZ exhibit distinct exposure times effects on MIO-M1 cells viability, metabolism, and cytokines/growth factors. Hypoxia and BVZ decreased MIO-M1 cell viability/metabolism, whereas AFL likely induced gliosis. Hypoxia resulted in immunosuppression, and BVZ stimulated inflammation in hypoxic MIO-M1 cells. These findings highlight the complexity of the cellular response as well as the interplay between anti-VEGF treatments and the hypoxic microenvironment.

Cryptic circulation of chikungunya virus in São Jose do Rio Preto, Brazil, 2015-2019.

BACKGROUND: Chikungunya virus (CHIKV) has spread across Brazil with varying incidence rates depending on the affected areas. Due to cocirculation of arboviruses and overlapping disease symptoms, CHIKV infection may be underdiagnosed. To understand the lack of CHIKV epidemics in São José do Rio Preto (SJdRP), São Paulo (SP), Brazil, we evaluated viral circulation by investigating anti-CHIKV IgG seroconversion in a prospective study of asymptomatic individuals and detecting anti-CHIKV IgM in individuals suspected of dengue infection, as well as CHIKV presence in Aedes mosquitoes. The opportunity to assess two different groups (symptomatic and asymptomatic) exposed at the same geographic region aimed to broaden the possibility of identifying the viral circulation, which had been previously considered absent. METHODOLOGY/PRINCIPAL FINDINGS: Based on a prospective population study model and demographic characteristics (sex and age), we analyzed the anti-CHIKV IgG seroconversion rate in 341 subjects by ELISA over four years. The seroprevalence increased from 0.35% in the first year to 2.3% after 3 years of follow-up. Additionally, we investigated 497 samples from a blood panel collected from dengue-suspected individuals during the 2019 dengue outbreak in SJdRP. In total, 4.4% were positive for anti-CHIKV IgM, and 8.6% were positive for IgG. To exclude alphavirus cross-reactivity, we evaluated the presence of anti-Mayaro virus (MAYV) IgG by ELISA, and the positivity rate was 0.3% in the population study and 0.8% in the blood panel samples. In CHIKV and MAYV plaque reduction neutralization tests (PRNTs), the positivity rate for CHIKV-neutralizing antibodies in these ELISA-positive samples was 46.7%, while no MAYV-neutralizing antibodies were detected. Genomic sequencing and phylogenetic analysis revealed CHIKV genotype ECSA in São José do Rio Preto, SP. Finally, mosquitoes collected to complement human surveillance revealed CHIKV positivity of 2.76% of A. aegypti and 9.09% of A. albopictus (although it was far less abundant than A. aegypti) by RT-qPCR. CONCLUSIONS/SIGNIFICANCE: Our data suggest cryptic CHIKV circulation in SJdRP detected by continual active surveillance. These low levels, but increasing, of viral circulation highlight the possibility of CHIKV outbreaks, as there is a large naïve population. Improved knowledge of the epidemiological situation might aid in outbreaks prevention.

Beliefs and practices of the nursing team related to pressure injury preventive measures: A analysis of social representations.

AIMS AND OBJECTIVES: To analyse the process of elaborating social representations about pressure injury preventive measures by the nursing team (nurses and nurse technicians) and how this process relates to preventive practices for hospitalized patients. DESIGN: Qualitative study, with the application of the theory of social representations in its procedural methodological approach. METHODS: The study was carried out in an inpatient clinic of a public hospital in the state of Rondônia, Brazil. Totally, 28 nursing professionals in the medical clinic sectors who had worked directly with patient care for more than 6 months participated. The data were collected between July and September 2021 via in-depth interviews with the application of a semi-structured instrument. Analysis was carried out with the help of ALCESTE software, which performed a lexicographic analysis, and also via thematic analysis. The COREQ guided the presentation of the research report. RESULTS: The social representations were developed based on the professionals' symbolic beliefs about the visibility/invisibility of the results of applying preventive care. These symbolic constructions mobilized positive and negative feelings among the nursing team, which guided the classification of prevention practices as being of greater or lesser priority among other care activities. There were favourable attitudes among professionals, which included applying prevention measures in their daily routines, and unfavourable attitudes of non-adherence to the institution's protocol for preventing pressure injuries. CONCLUSIONS: The nursing team's perception of pressure injury prevention is influenced by symbolic, affective, values, and social dimensions. Non-adherence behaviours are attributed to the belief in the invisibility of prevention outcomes, resulting in a reluctance to implement preventive measures. RELEVANCE TO CLINICAL PRACTICE: Understanding the subjective logic that explains the thinking and actions of the nursing team suggests the need to incorporate discussions on beliefs, values, sentiments, and attitudes of nursing professionals into educational programs on pressure injury prevention. PATIENT OR PUBLIC CONTRIBUTION: No public contribution.

Unraveling the Nano-Bio Interface Interactions of a Lipase Adsorbed on Gold Nanoparticles under Laser Excitation.

The complex nature and structure of biomolecules and nanoparticles and their interactions make it challenging to achieve a deeper understanding of the dynamics at the nano-bio interface of enzymes and plasmonic nanoparticles subjected to light excitation. In this study, circular dichroism (CD) and Raman spectroscopic experiments and molecular dynamics (MD) simulations were used to investigate the potential changes at the nano-bio interface upon plasmonic excitation. Our data showed that photothermal and thermal heating induced distinct changes in the secondary structure of a model nanobioconjugate composed of lipase fromCandida antarcticafraction B (CALB) and gold nanoparticles (AuNPs). The use of a green laser led to a substantial decrease in the α-helix content of the lipase from 66% to 13% and an increase in the ß-sheet content from 5% to 31% compared to the initial conformation of the nanobioconjugate. In contrast, the differences under similar thermal heating conditions were only 55% and 11%, respectively. This study revealed important differences related to the enzyme secondary structure, enzyme-nanoparticle interactions, and the stability of the enzyme catalytic triad (Ser105-Asp187-His224), influenced by the instantaneous local temperature increase generated from photothermal heating compared to the slower rate of thermal heating of the bulk. These results provide valuable insights into the interactions between biomolecules and plasmonic nanoparticles induced by photothermal heating, advancing plasmonic biocatalysis and related fields.

Comparison of energy expenditure of individuals with Duchenne muscular dystrophy in the sitting posture on the ground and in water.

Duchenne Muscular Dystrophy (DMD) is one of the most frequent childhood dystrophies, affecting cardiopulmonary functions and walking ability. One of the main symptoms is fatigue, which is caused by altered muscle metabolism related to energy expenditure (EE). Aquatic physiotherapy is a therapeutic modality that facilitates the maintenance of this posture because of immersion on the body. This cross-sectional observational study aimed to compare the EE on the ground and water of individuals with DMD through oxygen consumption in the maintenance of sitting posture. The individuals were in a sitting position on the ground and in the water for 20 min for the assessments. The variables peripheral oxygen saturation, heart rate, maximum expiratory pressure, maximum inspiratory pressure, forced vital capacity, respiratory quotient (RQ), and oxygen consumption per kilogram of body weight (VO2 /kg) were compared, adopting a significance of 5 %. No difference was found between medians and quartiles of RQ when comparing the two environments. The same was observed for VO2 /Kg values on the ground and in water. The data from this study demonstrate that the EE of individuals with DMD did not change when maintaining a sitting posture on the ground and in water.

Snapshots of the Reaction Coordinate of a Thermophilic 2'-Deoxyribonucleoside/ribonucleoside Transferase.

Nucleosides are ubiquitous to life and are required for the synthesis of DNA, RNA, and other molecules crucial for cell survival. Despite the notoriously difficult organic synthesis of nucleosides, 2'-deoxynucleoside analogues can interfere with natural DNA replication and repair and are successfully employed as anticancer, antiviral, and antimicrobial compounds. Nucleoside 2'-deoxyribosyltransferase (dNDT) enzymes catalyze transglycosylation via a covalent 2'-deoxyribosylated enzyme intermediate with retention of configuration, having applications in the biocatalytic synthesis of 2'-deoxynucleoside analogues in a single step. Here, we characterize the structure and function of a thermophilic dNDT, the protein from Chroococcidiopsis thermalis (CtNDT). We combined enzyme kinetics with structural and biophysical studies to dissect mechanistic features in the reaction coordinate, leading to product formation. Bell-shaped pH-rate profiles demonstrate activity in a broad pH range of 5.5-9.5, with two very distinct pKa values. A pronounced viscosity effect on the turnover rate indicates a diffusional step, likely product (nucleobase1) release, to be rate-limiting. Temperature studies revealed an extremely curved profile, suggesting a large negative activation heat capacity. We trapped a 2'-fluoro-2'-deoxyarabinosyl-enzyme intermediate by mass spectrometry and determined high-resolution structures of the protein in its unliganded, substrate-bound, ribosylated, 2'-difluoro-2'-deoxyribosylated, and in complex with probable transition-state analogues. We reveal key features underlying (2'-deoxy)ribonucleoside selection, as CtNDT can also use ribonucleosides as substrates, albeit with a lower efficiency. Ribonucleosides are the building blocks of RNA and other key intracellular metabolites participating in energy and metabolism, expanding the scope of use of CtNDT in biocatalysis.

Human 2'-Deoxynucleoside 5'-Phosphate N-Hydrolase 1: The Catalytic Roles of Tyr24 and Asp80.

The human enzyme 2'-deoxynucleoside 5'-phosphate N-hydrolase 1 (HsDNPH1) catalyses the hydrolysis of 5-hydroxymethyl-2'-deoxyuridine 5'-phosphate to generate 5-hydroxymethyluracil and 2-deoxyribose-5-phosphate via a covalent 5-phospho-2-deoxyribosylated enzyme intermediate. HsDNPH1 is a promising target for inhibitor development towards anticancer drugs. Here, site-directed mutagenesis of conserved active-site residues, followed by HPLC analysis of the reaction and steady-state kinetics are employed to reveal the importance of each of these residues in catalysis, and the reaction pH-dependence is perturbed by each mutation. Solvent deuterium isotope effects indicate no rate-limiting proton transfers. Crystal structures of D80N-HsDNPH1 in unliganded and substrate-bound states, and of unliganded D80A- and Y24F-HsDNPH1 offer atomic level insights into substrate binding and catalysis. The results reveal a network of hydrogen bonds involving the substrate and the E104-Y24-D80 catalytic triad and are consistent with a proposed mechanism whereby D80 is important for substrate positioning, for helping modulate E104 nucleophilicity, and as the general acid in the first half-reaction. Y24 positions E104 for catalysis and prevents a catalytically disruptive close contact between E104 and D80.

Proximate and fatty acid profile analysis of Tenebrio molitor and Zophobas morio using different killing methods.

The present work aimed to quantify the macronutrients and the fatty acid (FA) profile in different killing methods, blanching (BC) and freezing (FR), on edible insects of the speciesTenebrio molitor(TM) andZophobas morio(ZM). Concerning macronutrients TM-BC and TM-FR presented 51.2% and 50.6% of protein, 28% and 29.4% of lipids, and 12.4% and 11.4%. Meanwhile, ZM-BC and ZM-FR expressed 42.8% and 43.7% of protein, 39.1% and 40.1% of lipids, and 10.7% and 8.9% of carbohydrates. The FA of TM and ZM shows respectively values of Saturated Fatty Acids (∑SFA) 30% - 45%, Monounsaturated (MUFA) 47% - 32%, Polyunsaturated (∑PUFA) 23% - 22%, Atherogenicity Index (AI) 0.64 - 0.75, Thrombogenicity Index (TI) 0.77 - 1.44 and hypocholesterolemic/hypercholesterolemic index (h/H) of 2.50-1.51. Based on the results obtained, the slaughter methods showed statistically differences in relation to MUFA's in TM, and ZM larvae only in the minority fraction of FA.

Lack of Annexin A1 Exacerbates Inflammatory Response in Acute Endometritis Model.

Annexin A1 (AnxA1) is a glucocorticoid-inducible protein and an important endogenous modulator of inflammation. However, its effect in the endometrial microenvironment is poorly explained. This study aimed to evaluate the role of endogenous AnxA1 in an endometritis mouse model induced by lipopolysaccharide (LPS). Female C57BL/6 wild-type (WT) and AnxA1-/- mice were divided into two groups: SHAM and LPS. To induce endometritis, mice received a vaginal infusion of 50 µL of LPS (1 mg/mL) dissolved in phosphate-buffered saline. After 24 h, the mice were euthanized, and blood and uteri samples were collected. The endometrium inflammatory scores were significantly increased in the LPS-treated group. AnxA1-/- mice from the LPS group demonstrated a significant increase in the number of degranulated mast cell levels compared to AnxA1-/- SHAM mice. The Western blotting analysis revealed that a lack of AnxA1 promoted the upregulation of NLRP3 and pro-IL-1ß in the acute endometritis animal model compared to WT LPS animals. LPS-induced endometritis increased the number of blood peripheral leukocytes in both WT and AnxA1-/- mice compared with SHAM group mice (p < 0.001). AnxA1-/- mice also showed increased plasma levels of IL-1ß (p < 0.01), IL-6, IL-10, IL-17, and TNF-α (p < 0.05) following LPS-induced endometritis. In conclusion, a lack of endogenous AnxA1 exacerbated the inflammatory response in an endometritis model via NLRP3 dysregulation, increased uterine mast cell activation, and plasma pro-inflammatory cytokine release.

Inhibition of Rho kinase (ROCK) impairs cytoskeletal contractility in human Müller glial cells without effects on cell viability, migration, and extracellular matrix production.

The epiretinal membrane is a fibrocontractile tissue that forms on the inner surface of the retina, causing visual impairment ranging from mild to severe, and even retinal detachment. Müller glial cells actively participate in the formation of this membrane. Current research is constantly seeking for new therapeutic approaches that aim to prevent or treat cellular dysfunctions involved in the progression of this common fibrosis condition. The Rho GTPases signaling pathway regulates several processes associated with the epiretinal membrane, such as cell proliferation, migration, and contraction. Rho kinase (ROCK), an effector of the RhoA GTPase, is an interesting potential therapeutic target. This study aimed to evaluate the effects of a ROCK inhibitor (Y27632) on human Müller cells viability, growth, cytoskeletal organization, expression of extracellular matrix components, myofibroblast differentiation, migration, and contractility. Müller cells of the MIO-M1 lineage were cultured and treated for different periods with the inhibitor. Viability was evaluated by MTT assay and trypan blue exclusion method, and growth was evaluated by growth curve and BrdU incorporation assay. The actin cytoskeleton was stained with fluorescent phalloidin, intermediate filaments and microtubules were analyzed with immunofluorescence for vimentin and α-tubulin. Gene and protein expression of collagens I and V, laminin and fibronectin were evaluated by rt-PCR and immunofluorescence. Chemotactic and spontaneous cell migration were studied by transwell assay and time-lapse observation of live cells, respectively. Cell contractility was assessed by collagen gel contraction assay. The results showed that ROCK inhibition by Y27632 did not affect cell viability, but decreased cell growth and proliferation after 72 h. There was a change in cell morphology and organization of F-actin, with a reduction in the cell body, disappearance of stress fibers and formation of long, branched cell extensions. Microtubules and vimentin filaments were also affected, possibly because of F-actin alterations. The inhibitor also reduced gene expression and immunoreactivity of smooth muscle α-actin, a marker of myofibroblasts. The expression of extracellular matrix components was not affected by the inhibitor. Chemotactic cell migration showed no significant changes, while cell contractility was substantially reduced. No spontaneous migration of MIO-M1 cells was observed. In conclusion, pharmacological inhibition of ROCK in Müller cells could be a potentially promising approach to treat epiretinal membranes by preventing cell proliferation, contractility and transdifferentiation, without affecting cell viability.

Labelling of intravenous drug delivery devices in critically ill patients: A scoping review.

BACKGROUND: Labelling is a strategy that contributes to the correct and faster identification of drugs, minimizing misidentification. There is a gap in knowledge on optimal labelling standards for intravenous (IV) devices applied to the care of critically ill patients. AIM: The goal of this article was to map existing knowledge on the labelling of IV drug delivery devices in critically ill patients for the prevention of medication errors. STUDY DESIGN: This was a scoping review conducted according to the JBI methodology in the LILACS, MEDLINE, CINAHL, IBECS, Scopus, Embase and Web of Science databases, and on the websites of specialized institutions. Searches were conducted up to December 2022 for scientific articles and grey literature that addressed the labelling of IV devices in intensive care units, emergency departments, and anaesthesia units. The data were collected using a structured form and were later classified, summarized, and aggregated to map the knowledge related to the review question. RESULTS: Twenty-one documents were included, which demonstrated variability in label use with IV drug delivery devices. The following features of structure and design stood out: printed format, colour coding, letter size differentiation, and the use of sturdy material. In terms of information, the name of the drug, dose, date and time of preparation, identification of the patient, and who prepared it were found. CONCLUSIONS: The identified patterns contributed to the reduction of drug misidentification and the development of timelier drug labelling and administration. RELEVANCE TO CLINICAL PRACTICE: The evidence supports the development of standardized labels for the prevention of medication errors.

Crystal Structure, Steady-State, and Pre-Steady-State Kinetics of Acinetobacter baumannii ATP Phosphoribosyltransferase.

The first step of histidine biosynthesis in Acinetobacter baumannii, the condensation of ATP and 5-phospho-α-d-ribosyl-1-pyrophosphate to produce N1-(5-phospho-ß-d-ribosyl)-ATP (PRATP) and pyrophosphate, is catalyzed by the hetero-octameric enzyme ATP phosphoribosyltransferase, a promising target for antibiotic design. The catalytic subunit, HisGS, is allosterically activated upon binding of the regulatory subunit, HisZ, to form the hetero-octameric holoenzyme (ATPPRT), leading to a large increase in kcat. Here, we present the crystal structure of ATPPRT, along with kinetic investigations of the rate-limiting steps governing catalysis in the nonactivated (HisGS) and activated (ATPPRT) forms of the enzyme. A pH-rate profile showed that maximum catalysis is achieved above pH 8.0. Surprisingly, at 25 °C, kcat is higher when ADP replaces ATP as substrate for ATPPRT but not for HisGS. The HisGS-catalyzed reaction is limited by the chemical step, as suggested by the enhancement of kcat when Mg2+ was replaced by Mn2+, and by the lack of a pre-steady-state burst of product formation. Conversely, the ATPPRT-catalyzed reaction rate is determined by PRATP diffusion from the active site, as gleaned from a substantial solvent viscosity effect. A burst of product formation could be inferred from pre-steady-state kinetics, but the first turnover was too fast to be directly observed. Lowering the temperature to 5 °C allowed observation of the PRATP formation burst by ATPPRT. At this temperature, the single-turnover rate constant was significantly higher than kcat, providing additional evidence for a step after chemistry limiting catalysis by ATPPRT. This demonstrates allosteric activation by HisZ accelerates the chemical step.

Outbreak of extensively drug-resistant Serratia marcescens in an intensive care unit.

We present the investigation and control of an extensively drug-resistant Serratia marcescens outbreak in a 30-bed intensive care unit (ICU). Within 6 weeks, 4 critically ill trauma patients were infected by the same strain. Intensive containment measures limited the spread of this strain while sustaining the capacity of the trauma ICU.

Chemical Resemblance of Egg Surface Compounds and Dufour's Gland in Two Neotropical Polistinae Wasps Polistes versicolor (Olivier) and Mischocyttarus metathoracicus (de Saussure, 1854).

Chemical communication plays a major role in regulating social dynamics in social insect colonies. The most studied class of chemical compounds are the cuticular hydrocarbons (CHCs), compounds with high molecular weight that cover the insect body. CHCs are used in nestmate recognition and to signal reproductive status. Brood, in the form of larvae and eggs, is known to participate in chemical communication and social dynamics by performing hunger behaviour and inducing interaction with adults and conferring nest and maternity identity. CHCs of adults and egg surface compounds are similar in composition in social insect species. The main source of egg compounds is proposed to be Dufour's gland, an accessory reproductive gland found in several Hymenoptera females. There is still a lack of information about the level of similarity among CHCs, compounds of egg surface and Dufour's gland for several wasp species, which could provide correlational evidence about the origins of egg-marking compounds. Thus, we investigated whether egg surface compounds were more similar to CHCs or Dufour's gland secretions in two Neotropical primitively eusocial wasp species, Polistes versicolor (Olivier) and Mischocyttarus metathoracicus (de Saussure, 1854). As expected, there was a higher chemical similarity between eggs and Dufour's gland secretions in both studied species, supporting the hypothesis that this gland is the source of chemical compounds found over the eggs in these two primitively eusocial species.