Study of two glycosyltransferases related to polysaccharide biosynthesis in Rhodococcus jostii RHA1.

The bacterial genus Rhodococcus comprises organisms performing oleaginous behaviors under certain growth conditions and ratios of carbon and nitrogen availability. Rhodococci are outstanding producers of biofuel precursors, where lipid and glycogen metabolisms are closely related. Thus, a better understanding of rhodococcal carbon partitioning requires identifying catalytic steps redirecting sugar moieties to storage molecules. Here, we analyzed two GT4 glycosyl-transferases from Rhodococcus jostii (RjoGlgAb and RjoGlgAc) annotated as α-glucan-α-1,4-glucosyl transferases, putatively involved in glycogen synthesis. Both enzymes were produced in Escherichia coli cells, purified to homogeneity, and kinetically characterized. RjoGlgAb and RjoGlgAc presented the "canonical" glycogen synthase activity and were actives as maltose-1P synthases, although to a different extent. Then, RjoGlgAc is a homologous enzyme to the mycobacterial GlgM, with similar kinetic behavior and glucosyl-donor preference. RjoGlgAc was two orders of magnitude more efficient to glucosylate glucose-1P than glycogen, also using glucosamine-1P as a catalytically efficient aglycon. Instead, RjoGlgAb exhibited both activities with similar kinetic efficiency and preference for short-branched α-1,4-glucans. Curiously, RjoGlgAb presented a super-oligomeric conformation (higher than 15 subunits), representing a novel enzyme with a unique structure-to-function relationship. Kinetic results presented herein constitute a hint to infer on polysaccharides biosynthesis in rhodococci from an enzymological point of view.

A community-based advanced nurse practitioner-led integrated oncology care model for adults receiving oral anticancer medication: a pilot study.

Oral anti-cancer medications (OAMs) are being used increasingly within cancer care. OAMs offer the potential to improve patient convenience and increase hospital capacity. The clinical assessment for each cycle of OAMs requires specialist patient review often performed in hospital-based oncology units. Consequently, any potential improvement in patient expediency or increased hospital capacity that OAMs can offer is not realised. This study aimed to develop and pilot the specialist assessment of patients receiving OAMs by an Advanced Nurse Practitioner (ANP) in a community-based location.The primary aim of this pilot study was to assess the feasibility of a community-based ANP-led integrated oncology care model for adults receiving OAMs in Ireland who met the pre-specified eligibility criteria. The objectives were to determine the feasibility of a definitive trial of this intervention by measuring patient safety, acceptability to patients and staff and cost of the new model of care.This single-centre pilot study provided patient care (n = 37) to those receiving OAM therapies within a community setting for a 4-month period. Consent rate was high with no attrition other than for clinical reasons. There were 151 contacts with the sample during that time.Results demonstrated that the ANP-led intervention and new model for OAM care was safe, highly acceptable to patients and staff and that related healthcare costs could be captured. Based on the success of this pilot study, the authors conclude that a community-based ANP-led integrated oncology care model for adults receiving OAMs is feasible, and a definitive trial is warranted.Trial registration ISRCTN, ISRCTN10401455 . Registered 30 November 2020.

Early Metformin in Gestational Diabetes: A Randomized Clinical Trial.

Importance: Gestational diabetes is a common complication of pregnancy and the optimal management is uncertain. Objective: To test whether early initiation of metformin reduces insulin initiation or improves fasting hyperglycemia at gestation weeks 32 or 38. Design, Setting, and Participants: Double-blind, placebo-controlled trial conducted in 2 centers in Ireland (one tertiary hospital and one smaller regional hospital). Participants were enrolled from June 2017 through September 2022 and followed up until 12 weeks' postpartum. Participants comprised 510 individuals (535 pregnancies) diagnosed with gestational diabetes based on World Health Organization 2013 criteria. Interventions: Randomized 1:1 to either placebo or metformin (maximum dose, 2500 mg) in addition to usual care. Main Outcomes And Measures: The primary outcome was a composite of insulin initiation or a fasting glucose level of 5.1 mmol/L or greater at gestation weeks 32 or 38. Results: Among 510 participants (mean age, 34.3 years), 535 pregnancies were randomized. The primary composite outcome was not significantly different between groups and occurred in 150 pregnancies (56.8%) in the metformin group and 167 pregnancies (63.7%) in the placebo group (between-group difference, -6.9% [95% CI, -15.1% to 1.4%]; relative risk, 0.89 [95% CI, 0.78-1.02]; P = .13). Of 6 prespecified secondary maternal outcomes, 3 favored the metformin group, including time to insulin initiation, self-reported capillary glycemic control, and gestational weight gain. Secondary neonatal outcomes differed by group, with smaller neonates (lower mean birth weights, a lower proportion weighing >4 kg, a lower proportion in the >90% percentile, and smaller crown-heel length) in the metformin group without differences in neonatal intensive care needs, respiratory distress requiring respiratory support, jaundice requiring phototherapy, major congenital anomalies, neonatal hypoglycemia, or proportion with 5-minute Apgar scores less than 7. Conclusion and relevance: Early treatment with metformin was not superior to placebo for the composite primary outcome. Prespecified secondary outcome data support further investigation of metformin in larger clinical trials. Trial Registration: ClinicalTrials.gov Identifier: NCT02980276; EudraCT: 2016-001644-19.

On the occurrence of a glutaredoxin-like small protein in the anaerobic protozoan parasite Entamoeba histolytica.

BACKGROUND: Entamoeba histolytica, an intestinal parasitic protozoan that usually lives and multiplies within the human gut, is the causative agent of amoebiasis. To date, de novo glutathione biosynthesis and its associated enzymes have not been identified in the parasite. Cysteine has been proposed to be the main intracellular thiol. METHODS: Using bioinformatics tools to search for glutaredoxin homologs in the E. histolytica genome database, we identified a coding sequence for a putative Grx-like small protein (EhGLSP) in the E. histolytica HM-1:IMSS genome. We produced the recombinant protein and performed its biochemical characterization. RESULTS: Through in vitro experiments, we observed that recombinant EhGLSP could bind GSH and L-Cys as ligands. However, the protein exhibited very low GSH-dependent disulfide reductase activity. Interestingly, via UV-Vis spectroscopy and chemical analysis, we detected that recombinant EhGLSP (freshly purified from Escherichia coli cells by IMAC) was isolated together with a redox-labile [FeS] bio-inorganic complex, suggesting that this protein could have some function linked to the metabolism of this cofactor. Western blotting showed that EhGLSP protein levels were modulated in E. histolytica cells exposed to exogenous oxidative species and metronidazole, suggesting that this protein cooperates with the antioxidant mechanisms of this parasite. CONCLUSIONS AND GENERAL SIGNIFICANCE: Our findings support the existence of a new metabolic actor in this pathogen. To the best of our knowledge, this is the first report on this protein class in E. histolytica.

Trimodality therapy versus perioperative chemotherapy in the management of locally advanced adenocarcinoma of the oesophagus and oesophagogastric junction (Neo-AEGIS): an open-label, randomised, phase 3 trial.

BACKGROUND: The optimum curative approach to adenocarcinoma of the oesophagus and oesophagogastric junction is unknown. We aimed to compare trimodality therapy (preoperative radiotherapy with carboplatin plus paclitaxel [CROSS regimen]) with optimum contemporaneous perioperative chemotherapy regimens (epirubicin plus cisplatin or oxaliplatin plus fluorouracil or capecitabine [a modified MAGIC regimen] before 2018 and fluorouracil, leucovorin, oxaliplatin, and docetaxel [FLOT] subsequently). METHODS: Neo-AEGIS (CTRIAL-IE 10-14) was an open-label, randomised, phase 3 trial done at 24 centres in Europe. Patients aged 18 years or older with clinical tumour stage T2-3, nodal stage N0-3, and M0 adenocarcinoma of the oesophagus and oesophagogastric junction were randomly assigned to perioperative chemotherapy (three preoperative and three postoperative 3-week cycles of intravenous 50 mg/m2 epirubicin on day 1 plus intravenous 60 mg/m2 cisplatin or intravenous 130 mg/m2 oxaliplatin on day 1 plus continuous infusion of 200 mg/m2 fluorouracil daily or oral 625 mg/m2 capecitabine twice daily up to 2018, with four preoperative and four postoperative 2-week cycles of 2600 mg/m2 fluorouracil, 85 mg/m2 oxaliplatin, 200 mg/m2 leucovorin, and 50 mg/m2 docetaxel intravenously on day 1 as an option from 2018) or trimodality therapy (41·4 Gy in 23 fractions on days 1-5, 8-12, 15-19, 22-26, and 29-31 with intravenous area under the curve 2 mg/mL per min carboplatin plus intravenous 50 mg/m2 paclitaxel on days 1, 8, 15, 22, and 29). The primary endpoint was overall survival, assessed in all randomly assigned patients who received at least one dose of study drug, regardless of which study drug they received, by intention to treat. Secondary endpoints were disease-free survival, site of treatment failure, operative complications, toxicity, pathological response (complete [ypT0N0] and major [tumour regression grade 1 and 2]), margin-free resection (R0), and health-related quality of life. Toxicity and safety data were analysed in the safety population, defined as patients who took at least one dose of study drug, according to treatment actually received. The initial power calculation was based on superiority of trimodality therapy (n=366 patients); it was adjusted after FLOT became an option to a non-inferiority design with a margin of 5% for perioperative chemotherapy (n=540). This study is registered with ClinicalTrials.gov, NCT01726452. FINDINGS: Between Jan 24, 2013, and Dec 23, 2020, 377 patients were randomly assigned, of whom 362 were included in the intention-to treat population (327 [90%] male and 360 [99%] White): 184 in the perioperative chemotherapy group and 178 in the trimodality therapy group. The trial closed prematurely in December, 2020, after the second interim futility analysis (143 deaths), on the basis of similar survival metrics and the impact of the COVID-19 pandemic. At a median follow-up of 38·8 months (IQR 16·3-55·1), median overall survival was 48·0 months (95% CI 33·6-64·8) in the perioperative chemotherapy group and 49·2 months (34·8-74·4) in the trimodality therapy group (3-year overall survival 55% [95% CI 47-62] vs 57% [49-64]; hazard ratio 1·03 [95% CI 0·77-1·38]; log-rank p=0·82). Median disease-free survival was 32·4 months (95% CI 22·8-64·8) in the perioperative chemotherapy group and 24·0 months (18·0-40·8) in the trimodality therapy group [hazard ratio 0·89 [95% CI 0·68-1·17]; log-rank p=0·41). The pattern of recurrence, locoregional or systemic, was not significantly different (odds ratio 1·35 [95% CI 0·63-2·91], p=0·44). Pathological complete response (odds ratio 0·33 [95% CI 0·14-0·81], p=0·012), major pathological response (0·21 [0·12-0·38], p<0·0001), and R0 rates (0·21 [0·08-0·53], p=0·0003) favoured trimodality therapy. The most common grade 3-4 adverse event was neutropenia (49 [27%] of 183 patients in the perioperative chemotherapy group vs 11 [6%] of 178 patients in the trimodality therapy group), followed by diarrhoea (20 [11%] vs none), and pulmonary embolism (ten [5%] vs nine [5%]). One (1%) patient in the perioperative chemotherapy group and three (2%) patients in the trimodality therapy group died from serious adverse events, two (one in each group) of which were possibly related to treatment. No differences were seen in operative mortality (five [3%] deaths in the perioperative chemotherapy group vs four [2%] in the trimodality therapy group), major morbidity, or in global health status at 1 and 3 years. INTERPRETATION: Although underpowered and incomplete, Neo-AEGIS provides the largest comprehensive randomised dataset for patients with adenocarcinoma of the oesophagus and oesophagogastric junction treated with perioperative chemotherapy (predominantly the modified MAGIC regimen), and CROSS trimodality therapy, and reports similar 3-year survival and no major differences in operative and health-related quality of life outcomes. We suggest that these data support continued clinical equipoise. FUNDING: Health Research Board, Cancer Research UK, Irish Cancer Society, Oesophageal Cancer Fund, and French National Cancer Institute.

Transforming growth factor ß1 upregulates 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase-4 expression in A549 and MCF-10A cells.

Transforming growth factor ß1 (TGFß1) induces a cellular process known as epithelial-mesenchymal transition (EMT) associated with metabolic reprogramming, including enhanced glycolysis. Given the involvement of 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase (PFKFB) enzymes in glycolysis, we aimed to investigate whether TGFß1 regulates expressions of PFKFB genes and if PFKFBs are required for TGFß1-driven phenotypes. A549 and MCF-10A cell lines were used as TGFß1-driven EMT models. Messenger RNA expressions of PFKFB and EMT genes were determined by real-time quantitative polymerase chain reaction. A small interfering RNA approach was used to deplete PFKFB4 expression. A Matrigel invasion assay was conducted to assess the effect of PFKFB4 silencing on the TGFß1-enhanced invasion of A549 cells. F2,6BP levels were analyzed using an enzyme-coupled assay. Glucose and lactate concentrations were determined using colorimetric assays. TGFß1 robustly induced expression of the fourth isoform of PFKFBs, PFKFB4, in both cell lines. PFKFB4 depletion partially inhibits mesenchymal transdifferentiation caused by TGFß1 in A549 cells, as assessed by microscopy. Inductions of Snail in MCF-10A cells and Fibronectin in A549 cells and repressions of E-cadherin in both cell lines by TGFß1 are attenuated by PFKFB4 silencing. PFKFB4 silencing reduces F2,6BP and glycolytic activity, although TGFß1 alone does not affect these parameters. Finally, PFKFB4 depletion suppresses the TGFß1-driven invasion of A549 cells through Matrigel. Presented data suggest that TGFß1 induces the expression of PFKFB4 in A549 and MCF-10 cells, and PFKFB4 may be required for TGFß1-driven phenotypes such as EMT and invasion in these models.

Integrating multiple regulations on enzyme activity: the case of phosphoenolpyruvate carboxykinases.

Data on protein post-translational modifications (PTMs) increased exponentially in the last years due to the refinement of mass spectrometry techniques and the development of databases to store and share datasets. Nevertheless, these data per se do not create comprehensive biochemical knowledge. Complementary studies on protein biochemistry are necessary to fully understand the function of these PTMs at the molecular level and beyond, for example, designing rational metabolic engineering strategies to improve crops. Phosphoenolpyruvate carboxykinases (PEPCKs) are critical enzymes for plant metabolism with diverse roles in plant development and growth. Multiple lines of evidence showed the complex regulation of PEPCKs, including PTMs. Herein, we present PEPCKs as an example of the integration of combined mechanisms modulating enzyme activity and metabolic pathways. PEPCK studies strongly advanced after the production of the recombinant enzyme and the establishment of standardized biochemical assays. Finally, we discuss emerging open questions for future research and the challenges in integrating all available data into functional biochemical models.

A critical inter-subunit interaction for the transmission of the allosteric signal in the Agrobacterium tumefaciens ADP-glucose pyrophosphorylase.

ADP-glucose pyrophosphorylase is a key regulatory enzyme involved in starch and glycogen synthesis in plants and bacteria, respectively. It has been hypothesized that inter-subunit communications are important for the allosteric effect in this enzyme. However, no specific interactions have been identified as part of the regulatory signal. The enzyme from Agrobacterium tumefaciens is a homotetramer allosterically regulated by fructose 6-phosphate and pyruvate. Three pairs of distinct subunit-subunit interfaces are present. Here we focus on an interface that features two symmetrical interactions between Arg11 and Asp141 from one subunit with residues Asp141 and Arg11 of the neighbor subunit, respectively. Previously, scanning mutagenesis showed that a mutation at the Arg11 position disrupted the activation of the enzyme. Considering the distance of these residues from the allosteric and catalytic sites, we hypothesized that the interaction between Arg11 and Asp141 is critical for allosteric signaling rather than effector binding. To prove our hypothesis, we mutated those two sites (D141A, D141E, D141N, D141R, R11D, and R11K) and performed kinetic and binding analysis. Mutations that altered the charge affected the regulation the most. To prove that the interaction per se (rather than the presence of specific residues) is critical, we partially rescued the R11D protein by introducing a second mutation (R11D/D141R). This could not restore the activator effect on kcat , but it did rescue the effect on substrate affinity. Our results indicate the critical functional role of Arg11 and Asp141 to relay the allosteric signal in this subunit interface.

Understanding the role of mask-wearing during COVID-19 on the island of Ireland.

Non-pharmaceutical interventions have played a key role in managing the COVID-19 pandemic, but it is challenging to estimate their impacts on disease spread and outcomes. On the island of Ireland, population mobility restrictions were imposed during the first wave, but mask-wearing was not mandated until about six months into the pandemic. We use data on mask-wearing, mobility, and season, over the first year of the pandemic to predict independently the weekly infectious contact estimated by an epidemiological model. Using our models, we make counterfactual predictions of infectious contact, and ensuing hospitalizations, under a hypothetical intervention where 90% of the population wore masks from the beginning of community spread until the dates of the mask mandates. Over periods including the first wave of the pandemic, there were 1601 hospitalizations with COVID-19 in Northern Ireland and 1521 in the Republic of Ireland. Under the counterfactual mask-wearing scenario, we estimate 512 (95% CI 400, 730) and 344 (95% CI 266, 526) hospitalizations in the respective jurisdictions during the same periods. This could be partly due to other factors that were also changing over time.

Biochemical characterization of GAF domain of free-R-methionine sulfoxide reductase from Trypanosoma cruzi.

Trypanosoma cruzi is the causal agent of Chagas Disease and is a unicellular parasite that infects a wide variety of mammalian hosts. The parasite exhibits auxotrophy by L-Met; consequently, it must be acquired from the extracellular environment of the host, either mammalian or invertebrate. Methionine (Met) oxidation produces a racemic mixture (R and S forms) of methionine sulfoxide (MetSO). Reduction of L-MetSO (free or protein-bound) to L-Met is catalyzed by methionine sulfoxide reductases (MSRs). Bioinformatics analyses identified the coding sequence for a free-R-MSR (fRMSR) enzyme in the genome of T. cruzi Dm28c. Structurally, this enzyme is a modular protein with a putative N-terminal GAF domain linked to a C-terminal TIP41 motif. We performed detailed biochemical and kinetic characterization of the GAF domain of fRMSR in combination with mutant versions of specific cysteine residues, namely, Cys12, Cys98, Cys108, and Cys132. The isolated recombinant GAF domain and full-length fRMSR exhibited specific catalytic activity for the reduction of free L-Met(R)SO (non-protein bound), using tryparedoxins as reducing partners. We demonstrated that this process involves two Cys residues, Cys98 and Cys132. Cys132 is the essential catalytic residue on which a sulfenic acid intermediate is formed. Cys98 is the resolutive Cys, which forms a disulfide bond with Cys132 as a catalytic step. Overall, our results provide new insights into redox metabolism in T. cruzi, contributing to previous knowledge of L-Met metabolism in this parasite.

Population attributable fraction of hypertension for dementia: global, regional, and national estimates for 186 countries.

Background: Quantifying the proportion of dementia attributable to highly prevalent modifiable risk factors, such as hypertension, is important in informing effective dementia prevention strategies. We aim to quantify the population attributable fraction (PAF) of hypertension for dementia (the proportion of dementia cases that would not occur if hypertension was eliminated) at global, regional, and national levels. Methods: In this study, we searched international and governmental websites for global, regional, and national data reporting population hypertension (according to 10-year age categories) and dementia prevalence. MEDLINE was searched for studies reporting the risk of dementia from age at hypertension diagnosis from database inception to December 31, 2022. Longitudinal observational studies with >500 participants reporting hazard ratios by age at hypertension diagnosis for risk of future all-cause dementia were eligible for inclusion. Studies excluded had cross-sectional methodology, specific vascular dementia or 'cognitive impairment' outcomes, and no age-specific metrics of association reported. The PAF of hypertension for dementia was calculated globally and for each country and region worldwide. Findings: Data from the Global Burden of Disease, United Nations Population Prospectus, NCD Risk Factor Collaboration, UK Biobank, and Atherosclerosis Risk in Communities Study were obtained. 186 countries reported dementia and hypertension prevalence data. The global PAF of hypertension for dementia was 15.8% [95% Credible Interval (CI), 8.8%-22.7%]. Latin America and the Caribbean (18.0% [95% CI, 9.4%-26.6%]), and Europe (17.2% [95% CI, 9.6%-24.7%]) had the highest PAF of hypertension for dementia. Hypertension diagnosed between the ages of 30-44 had the highest age-specific global attributable fraction for dementia (8.4% [95% CI, 3.4%-13.5%]), followed by ages 45-54 (2.92% [ 95% CI, 0.96%-4.88%]), 55-64 (2.59% [95% CI, 1.15%-4.03%]) and 65-74 (1.82% [95% CI, -2.31%-5.96%]). Interpretation: The population attributable risk of hypertension for dementia is 15.8%, suggesting that optimal detection and treatment, particularly at midlife, has the potential to markedly reduce the global burden of dementia. Funding: Wellcome Trust; Health Research Board of Ireland; Alzheimer's Association.

Estimating time-dependent contact: a multi-strain epidemiological model of SARS-CoV-2 on the island of Ireland.

Mathematical modelling plays a key role in understanding and predicting the epidemiological dynamics of infectious diseases. We construct a flexible discrete-time model that incorporates multiple viral strains with different transmissibilities to estimate the changing patterns of human contact that generates new infections. Using a Bayesian approach, we fit the model to longitudinal data on hospitalisation with COVID-19 from the Republic of Ireland and Northern Ireland during the first year of the pandemic. We describe the estimated change in human contact in the context of government-mandated non-pharmaceutical interventions in the two jurisdictions on the island of Ireland. We take advantage of the fitted model to conduct counterfactual analyses exploring the impact of lockdown timing and introducing a novel, more transmissible variant. We found substantial differences in human contact between the two jurisdictions during periods of varied restriction easing and December holidays. Our counterfactual analyses reveal that implementing lockdowns earlier would have decreased subsequent hospitalisation substantially in most, but not all cases, and that an introduction of a more transmissible variant - without necessarily being more severe - can cause a large impact on the health care burden.

Dietary counselling to reduce moderate sodium intake: effects on cardiovascular and renal biomarkers: primary findings of the COSIP and STICK phase II feasibility randomised controlled trials.

Background: While low sodium intake (<2.3 g/day) is recommended, there is uncertainty about long-term feasibility and effects on cardiorenal biomarkers in populations with moderate intake. Methods: In two phase IIb, feasibility, randomised, parallel, open-label, controlled, single-centre trials, individuals aged >40 years with stable blood pressure (BP), without heart failure or postural hypotension were randomised to intensive dietary counselling (target sodium intake <2.3 g/day) or usual care between March 2016 and July 2018. One trial included participants with chronic kidney disease (CKD); the other excluded those with CKD or cardiovascular disease. All participants received healthy eating advice. Primary outcomes were NT-pro B-type natriuretic peptide (NT-proBNP), high sensitivity troponin T (hsTnT), C-reactive protein (CRP), renin, aldosterone and, creatinine clearance (CrCl) at 2-years. These trials are registered with ClinicalTrials.gov, STICK trial (NCT02458248) and COSIP trial (NCT02738736). Findings: 373 participants, with mean 24-h urine sodium 3.16 ± 1.47 g/day, were randomised to intervention (n = 187) or usual care (n = 186). At 3-months, the intervention reduced 24-h urine sodium (intervention -0.11 g/day, usual care +0.28 g/day, p = 0.003), BP (systolic -2.52 mmHg, p = 0.05; diastolic -1.92, p = 0.02) and increased renin (+33.35 mIU/L [95%CI 3.78-62.91]). At 2-years, the intervention significantly reduced self-reported salt use (p < 0.001), but not 24-h urine sodium (intervention -0.23 g/day, usual care +0.05 g/day, p = 0.47). At 2-years, there were no significant between-group differences in BP (systolic p = 0.66; diastolic p = 0.09), NT-proBNP (p = 0.68), hsTnT (p = 0.20), CRP (p = 0.56), renin (p = 0.52), aldosterone (p = 0.61), or CrCl (p = 0.68). Interpretation: Among individuals with moderate sodium intake, intensive dietary counselling resulted in small short-term reductions in sodium intake and BP, but no significant effect on sodium intake, BP, or cardiorenal biomarkers at two years. Our trial suggests that it may not feasible to reduce sodium sustainably in those with a sodium intake around 3.0 g/day, through an intensive dietary counselling intervention. Funding: The STICK trial was funded by the Health Research Board of Ireland and the COSIP trial was funded by the European Research Council.

Insights to improve the activity of glycosyl phosphorylases from Ruminococcus albus 8 with cello-oligosaccharides.

The phosphorolysis of cello-oligosaccharides is a critical process played in the rumen by Ruminococcus albus to degrade cellulose. Cellodextrins, made up of a few glucosyl units, have gained lots of interest by their potential applications. Here, we characterized a cellobiose phosphorylase (RalCBP) and a cellodextrin phosphorylase (RalCDP) from R. albus 8. This latter was further analyzed in detail by constructing a truncated mutant (Ral∆N63CDP) lacking the N-terminal domain and a chimeric protein by fusing a CBM (RalCDP-CBM37). RalCBP showed a typical behavior with high activity on cellobiose. Instead, RalCDP extended its activity to longer soluble or insoluble cello-oligosaccharides. The catalytic efficiency of RalCDP was higher with cellotetraose and cellopentaose as substrates for both reaction directions. Concerning properties of Ral∆N63CDP, results support roles for the N-terminal domain in the conformation of the homo-dimer and conferring the enzyme the capacity to catalyze the phosphorolytic reaction. This mutant exhibited reduced affinity toward phosphate and increased to glucose-1-phosphate. Further, the CBM37 module showed functionality when fused to RalCDP, as RalCDP-CBM37 exhibited an enhanced ability to use insoluble cellulosic substrates. Data obtained from this enzyme's binding parameters to cellulosic polysaccharides agree with the kinetic results. Besides, studies of synthesis and phosphorolysis of cello-saccharides at long-time reactions served to identify the utility of these enzymes. While RalCDP produces a mixture of cello-oligosaccharides (from cellotriose to longer oligosaccharides), the impaired phosphorolytic activity makes Ral∆N63CDP lead mainly toward the synthesis of cellotetraose. On the other hand, RalCDP-CBM37 remarks on the utility of obtaining glucose-1-phosphate from cellulosic compounds.

The involvement of allosteric effectors and post-translational modifications in the control of plant central carbon metabolism.

Plant metabolism is finely orchestrated to allow the occurrence of complementary and sometimes opposite metabolic pathways. In part this is achieved by the allosteric regulation of enzymes, which has been a cornerstone of plant research for many decades. The completion of the Arabidopsis genome and the development of the associated toolkits for Arabidopsis research moved the focus of many researchers to other fields. This is reflected by the increasing number of high-throughput proteomic studies, mainly focused on post-translational modifications. However, follow-up 'classical' biochemical studies to assess the functions and upstream signaling pathways responsible for such modifications have been scarce. In this work, we review the basic concepts of allosteric regulation of enzymes involved in plant carbon metabolism, comprising photosynthesis and photorespiration, starch and sucrose synthesis, glycolysis and gluconeogenesis, the oxidative pentose phosphate pathway and the tricarboxylic acid cycle. Additionally, we revisit the latest results on the allosteric control of the enzymes involved in these pathways. To conclude, we elaborate on the current methods for studying protein-metabolite interactions, which we consider will become crucial for discoveries in the future.

Sleep Patterns and the Risk of Acute Stroke: Results From the INTERSTROKE International Case-Control Study.

BACKGROUND AND OBJECTIVES: Symptoms of sleep disturbance are common and may represent important modifiable risk factors of stroke. We evaluated the association between a spectrum of sleep disturbance symptoms and the risk of acute stroke in an international setting. METHODS: The INTERSTROKE study is an international case-control study of patients presenting with first acute stroke and controls matched by age (±5 years) and sex. Sleep symptoms in the previous month were assessed through a questionnaire. Conditional logistic regression estimated the association between sleep disturbance symptoms and acute stroke, expressed as odds ratios (ORs) and 95% CIs. The primary model adjusted for age, occupation, marital status, and modified Rankin scale at baseline, with subsequent models adjusting for potential mediators (behavioral/disease risk factors). RESULTS: Overall, 4,496 matched participants were included, with 1,799 of them having experienced an ischemic stroke and 439 an intracerebral hemorrhage. Short sleep (<5 hours: OR 3.15, 95% CI 2.09-4.76), long sleep (>9 hours: OR 2.67, 95% CI 1.89-3.78), impaired quality (OR 1.52, 95% CI 1.32-1.75), difficulty getting to sleep (OR 1.32, 95% CI 1.13-1.55) or maintaining sleep (OR 1.33, 95% CI 1.15-1.53), unplanned napping (OR 1.48, 95% CI 1.20-1.84), prolonged napping (>1 hour: OR 1.88, 95% CI 1.49-2.38), snoring (OR 1.91, 95% CI 1.62-2.24), snorting (OR 2.64, 95% CI 2.17-3.20), and breathing cessation (OR 2.87, 95% CI 2.28-3.60) were all significantly associated with an increased odds of acute stroke in the primary model. A derived obstructive sleep apnea score of 2-3 (2.67, 2.25-3.15) and cumulative sleep symptoms (>5: 5.38, 4.03-7.18) were also associated with a significantly increased odds of acute stroke, with the latter showing a graded association. After an extensive adjustment, significance was maintained for most of the symptoms (not difficulty getting to/maintaining sleep and unplanned napping), with similar findings for stroke subtypes. DISCUSSION: We found that sleep disturbance symptoms were common and associated with a graded increased risk of stroke. These symptoms may be a marker of increased individual risk or represent independent risk factors. Future clinical trials are warranted to determine the efficacy of sleep interventions in stroke prevention.

Depressive symptoms and risk of acute stroke: INTERSTROKE case-control study

METHODS: The INTERSTROKE is an international case-control study of risk factors of first acute stroke, conducted in 32 countries. Cases were patients with CT- or MRI-confirmed incident acute hospitalized stroke, and controls were matched for age, sex, and within sites. Standardized questions asked about self-reported depressive symptoms during the previous 12 months and the use of prescribed antidepressant medications were recorded. Multivariable conditional logistic regression was used to determine the association of prestroke depressive symptoms with acute stroke risk. Adjusted ordinal logistic regression was used to explore the association of prestroke depressive symptoms with poststroke functional outcome, measured with the modified Rankin scale at 1 month after stroke. RESULTS: Of 26,877 participants, 40.4% were women, and the mean age was 61.7 ± 13.4 years. The prevalence of depressive symptoms within the last 12 months was higher in cases compared with that in controls (18.3% vs 14.1%, p < 0.001) and differed by region (p interaction <0.001), with lowest prevalence in China (6.9% in controls) and highest in South America (32.2% of controls). In multivariable analyses, prestroke depressive symptoms were associated with greater odds of acute stroke (odds ratio [OR] 1.46, 95% CI 1.34-1.58), which was significant for both intracerebral hemorrhage (OR 1.56, 95% CI 1.28-1.91) and ischemic stroke (OR 1.44, 95% CI 1.31-1.58). A larger magnitude of association with stroke was seen in patients with a greater burden of depressive symptoms. While preadmission depressive symptoms were not associated with a greater odds of worse baseline stroke severity (OR 1.02, 95% CI 0.94-1.10), they were associated with a greater odds of poor functional outcome at 1 month after acute stroke (OR 1.09, 95% CI 1.01-1.19). DISCUSSION: In this global study, we recorded that depressive symptoms are an important risk factor of acute stroke, including both ischemic and hemorrhagic stroke. Preadmission depressive symptoms were associated with poorer functional outcome, but not baseline stroke severity, suggesting an adverse role of depressive symptoms in poststroke recovery.

Depressive Symptoms and Risk of Acute Stroke: INTERSTROKE Case-Control Study.

BACKGROUND AND OBJECTIVES: Depression has been reported to be a risk factor of acute stroke, based largely on studies in high-income countries. In the INTERSTROKE study, we explored the contribution of depressive symptoms to acute stroke risk and 1-month outcome across regions of the world, within subpopulations and by stroke type. METHODS: The INTERSTROKE is an international case-control study of risk factors of first acute stroke, conducted in 32 countries. Cases were patients with CT- or MRI-confirmed incident acute hospitalized stroke, and controls were matched for age, sex, and within sites. Standardized questions asked about self-reported depressive symptoms during the previous 12 months and the use of prescribed antidepressant medications were recorded. Multivariable conditional logistic regression was used to determine the association of prestroke depressive symptoms with acute stroke risk. Adjusted ordinal logistic regression was used to explore the association of prestroke depressive symptoms with poststroke functional outcome, measured with the modified Rankin scale at 1 month after stroke. RESULTS: Of 26,877 participants, 40.4% were women, and the mean age was 61.7 ± 13.4 years. The prevalence of depressive symptoms within the last 12 months was higher in cases compared with that in controls (18.3% vs 14.1%, p < 0.001) and differed by region (p interaction <0.001), with lowest prevalence in China (6.9% in controls) and highest in South America (32.2% of controls). In multivariable analyses, prestroke depressive symptoms were associated with greater odds of acute stroke (odds ratio [OR] 1.46, 95% CI 1.34-1.58), which was significant for both intracerebral hemorrhage (OR 1.56, 95% CI 1.28-1.91) and ischemic stroke (OR 1.44, 95% CI 1.31-1.58). A larger magnitude of association with stroke was seen in patients with a greater burden of depressive symptoms. While preadmission depressive symptoms were not associated with a greater odds of worse baseline stroke severity (OR 1.02, 95% CI 0.94-1.10), they were associated with a greater odds of poor functional outcome at 1 month after acute stroke (OR 1.09, 95% CI 1.01-1.19). DISCUSSION: In this global study, we recorded that depressive symptoms are an important risk factor of acute stroke, including both ischemic and hemorrhagic stroke. Preadmission depressive symptoms were associated with poorer functional outcome, but not baseline stroke severity, suggesting an adverse role of depressive symptoms in poststroke recovery.

Evaluating the feasibility and preliminary efficacy of a Cognitive Occupation-Based programme for people with Multiple Sclerosis (COB-MS): an update to the protocol for a feasibility cluster-randomised controlled trial.

BACKGROUND: Cognitive difficulties experienced by people with multiple sclerosis (MS) impact on quality of life and daily functioning, from childcare and work to social and self-care activities. The Cognitive Occupation-Based programme for people with MS (COB-MS) was developed as a holistic, individualised cognitive rehabilitation intervention to address the wide-ranging symptoms and functional difficulties that present in MS, including the ability to maintain employment, social activities, home management and self-care. The aim of the research is to evaluate the feasibility and preliminary efficacy of COB-MS for people with MS. METHODS: Due to the impacts of COVID-19, trial activities that were planned for in-person delivery were completed remotely. One hundred and twenty people with MS will be assigned to participate in either the COB-MS programme or a treatment-as-usual, wait-list control group as part of this single-blind, cluster-randomised controlled feasibility and preliminary efficacy trial of the COB-MS programme. The COB-MS group will participate in an eight-session occupational-based cognitive rehabilitation programme over 9 weeks. The COB-MS intervention was planned for in-person delivery but was delivered online by occupational therapists to small groups of people with MS. The primary outcome measure is the Goal Attainment Scaling at 12 weeks. Participants will be assessed pre-intervention, post-intervention, 12 weeks post-intervention and 6 months post-intervention. Qualitative evaluations of participants' perspectives will also be examined as part of the feasibility study. Data, due to be collected in-person, was collected online or by post. The original study design, including the statistical analysis plan, remains unchanged despite the shift to a remote trial conduct. DISCUSSION: Results will provide recommendations for a future definitive trial of COB-MS, with respect to both feasibility and preliminary, clinical efficacy. TRIAL REGISTRATION: ISRCTN ISRCTN11462710 . Registered on 9 September 2019 and updated on 23 September 2020 to account for changes outlined here.

Remote administration of BICAMS measures and the Trail-Making Test to assess cognitive impairment in multiple sclerosis.

Reliable remote cognitive testing could provide a safer assessment of cognitive impairment in multiple sclerosis (MS) during the COVID-19 pandemic and thereafter. Here we aimed to investigate the reliability and feasibility of administering Brief International Cognitive Assessment for MS (BICAMS) and the Trail-Making Test (TMT) to people with MS online. Between-group differences on BICAMS and the TMT were examined in a sample of 68 participants. Group 1 (N = 34) was tested in-person pre-pandemic. Group 2 was tested remotely. Within-group differences for in-person and virtual administrations were examined for Group 1. No significant differences between virtual and in-person administrations of the CVLT-II and SDMT were detected. BVMT-R scores were significantly higher for virtual administrations (M = 20.59, SD = 6.65) compared to in-person administrations (M = 16.35, SD = 6.05), possibly indicating inter-rater differences. Strong positive correlations were found for in-person and virtual scores within Group 1 on the CVLT-II (r = .84), SDMT (r = .85), TMT-A (r = .88), TMT-B (r = .76) and BVMT-R (r = .72). No significant differences between in-person and remote administrations of CVLT-II and SDMT in people living with MS were detected. Recommendations for future studies employing the TMT and BVMT-R online are provided.