Epigenetic regulation by metabolites from the gut microbiome

The gut microbiome can metabolise food components, such as dietary fibres and various phytochemicals; and the microbiome can also synthesise some nutrients, for example B vitamins. The metabolites produced by bacteria and other micro-organisms in the colon can have implications for health and disease risk. Some of these metabolites are epigenetically active, and can contribute to changes in the chemical modification and structure of chromatin by affecting the activity and expression of epigenetically-active enzymes, for example histone deacetylases and DNA methyltransferases. The epigenetic activity of such gut microbiome metabolites is reviewed herein.

P75 PRELIMINARY FINDINGS OF THE DAVIDS REGISTRY (DYEVERT TO AVOID UNNECESSARY CONTRAST MEDIA DELIVERY DURING PCI SANREMO REGISTRY)

Background

Contrast–induced acute kidney injury (CI–AKI) is a percutaneous coronary intervention’s (PCI) feared complication, linked to increased morbidity and mortality. Many risk factors have been identified. Amongst procedural variables contrast media (CM) volume is one of the most predictive. An easy–to–use and effective CM sparing device would represent a valuable tool in the cath–lab armamentarium.

Aim

To evaluate the effectiveness of the DyeVert Power XT system in reducing CM delivery during PCI in pts at high risk of CI–AKI, consequently reducing the risk itself. Methods We collected clinical, laboratory, instrumental, procedural and outcome data of 75 consecutive patients (pts) who underwent PCI with the use of the DyeVert system between September 2020 and December 2021. We also compared these data in two groups of patients, divided according to CI–AKI onset. Inclusion criteria were reduced estimated glomerular filtration rate (eGFR) – defined as creatinine clearance (CrCl) <60 mL/min/m2 – and/or need for a complex PCI – chronic total occlusion (CTO), previous coronary artery bypass graft (CABG) or diffuse multivessel disease (MVD) – with the likelihood to receive a high amount of CM.

Results

Clinical data are shown in Table 1. Lab and instrumental data are shown in Table 2. Procedural data are shown in Table 3. In–hospital events are shown in Table 4. CI–AKI predictors at multivariate analysis are shown in Table 5. Median dose of CM delivered was 255 ml while CM spared with DyeVert was 110 ml (43% volume reduction, median 1 point reduction in Mehran score). Turning to outcomes 11 pts (14.7%) experienced AKI stage I according to Kidney Disease – Improving Global Outcomes (KDIGO) definition, whilst only 3 pts (4%) and 2 pts (2.7%) experienced stage 2 and 3 AKI. At follow–up there were 4 in–hospital deaths, none linked to deteriorating renal function.

Conclusions

DyeVert use was simple and effective in cutting delivered CM amount, with preserved image quality according to the operators judgement, however the reduction in Mehran score was not sufficient to affect risk class in pts experiencing CI–AKI versus those who did not.

A New Formulation for Quenching Processes under Restricted Geometry Conditions in the Slow Exchange Limit

A quantitative treatment of quenching processes under restricted geometry conditions in the Slow Exchange Limit is presented. The expressions for KSV have been obtained for this limit in some common situations that can arise in studies under restricted geometry conditions, such as an inhomogeneous quencher distribution in the solution, the presence of oxygen in solution, or the case of solutions containing a mixture of receptors. These situations have been considered and incorporated into the treatment.

[Natalizumab and reduction of carbonylated proteins in patients with multiple sclerosis]

INTRODUCTION

The sensitivity of the central nervous system to oxidative damage and its relationship with inflammatory response are well known. Recent studies have shown that oxidative stress is present in the establishment and development of multiple sclerosis (MS). One of the most recent treatments in this process is natalizumab, a monoclonal antibody.

AIM

To evaluate whether the therapeutic effect of natalizumab is associated with the severity of the disease and the oxidative damage.

PATIENTS AND METHODS

Researchers recruited twenty patients with relapsing-remitting MS (RRMS) undergoing therapy with natalizumab and distributed, according to the Expanded Disability Status Scale (EDSS), in two groups: RRMS-1 (EDSS < 5) and RRMS-2 (EDSS ≥ 5). Blood samples were taken for an oxidative profile study.

RESULTS

Data showed a decrease in carbonylated proteins following treatment with natalizumab. The reduction in oxidative damage rated as protein oxidation is significant between the previous (baseline) situation of the patient and after 14 months' treatment. The most significant decrease coincided with the patients with the highest levels of severity in the process. Although it has not been possible to establish a correlation, the statistical significance is higher for patients in the RRMS-2 group treated with natalizumab. The antioxidant systems, on the other hand, did not display any statistically significant changes.

CONCLUSIONS

Natalizumab brings about a reduction in carbonylated protein levels.

Differential expression of Phaseolus vulgaris genes induced during the interaction with Rhizoctonia solani

Common bean (Phaseolus vulgaris L.) is the most important grain legume for direct human consumption; however, bean production is affected by several diseases such as Rhizoctonia root rot. Few bean cultivars have been identified that effectively resist the attack of this fungus. Herein, we used the P. vulgaris Pv-2094 landrace, which is less susceptible to Rhizoctonia root rot, for the construction of a suppressive subtractive hybridization cDNA library in order to isolate plant defense-related genes. Total RNAs obtained after 8 and 16 h from inoculated and non-inoculated roots with R. solani Kühn, were used as the source of the "tester" and the "driver" samples, respectively. A total of 136 unigenes were obtained and classified into 12 functional categories. Six unigenes were selected to analyze for differential expression by qRT-PCR, including a receptor-like kinase (PvRK20-1), an acid phosphatase associated to defense (PA), a pathogenesis related protein (PR1), an ethylene responsive factor (ERF), a polygalacturonase inhibitor protein (PGIP), and an alpha-dioxygenase (α-DOX). These genes were found to be differentially expressed in a time-dependent manner in bean roots during the interaction with R. solani. Data generated from this study will contribute to the understanding of the molecular mechanisms associated with plant defense against root rot in common bean.

Nosocomial outbreak of Blastoschizomyces capitatus associated with contaminated milk in a haematological unit

In July 2002, Blastoschizomyces capitatus was isolated from four neutropenic patients in a haematology unit. Two patients died due to disseminated infection while the other two had oropharyngeal colonisation. Nosocomial acquisition of the fungus was suspected and epidemiological and environmental studies were undertaken. To determine the potential source for the acquisition of the fungus, epidemiological relationships between the patients were investigated. We performed surveillance cultures on all patients and took environmental cultures of air, inanimate surfaces, food samples, blood products and chemotherapy drugs. No direct contact transmission between patients was found and B. capitatus was isolated only in vacuum flasks used for breakfast milk distribution. All isolates were compared by four independent molecular typing methods: pulsed-field gel electrophoresis, genomic DNA restriction endonuclease analysis, randomly amplified polymorphic DNA, and polymerase chain reaction fingerprinting using a single primer specific for one minisatellite or two microsatellite DNAs. Milk vacuum flasks and clinical strains were genetically indistinguishable by all typing techniques. Milk vacuum flasks were withdrawn from all hospital units and no further B. capitatus infection was detected. Our findings suggest that clonal dissemination of a single strain of B. capitatus from vacuum flasks used for milk distribution was responsible for this nosocomial outbreak in the haematological unit.

Predictors of candidaemia caused by non-albicans Candida species: results of a population-based surveillance in Barcelona, Spain

Although Candida albicans (CA) is the most common cause of Candida bloodstream infections (BSIs), recent studies have observed an increasing percentage of candidaemias caused by non-albicans Candida species (NAC). In the present study, we attempted to identify the predictors of candidaemia due to NAC compared to CA. We analyzed data from an active population-based surveillance in Barcelona (Spain) from January 2002 to December 2003. Factors associated with NAC fungaemia were determined by multivariate analysis. A total of 339 episodes of Candida BSI, in 336 patients (median age 63 years, interquartile range: 41-72 years), were included. CA was the most commonly isolated (52%), followed by Candida parapsilosis (23%), Candida tropicalis (10%), Candida glabrata (8.6%), Candida krusei (3.4%) and other NAC spp. (3%).Overall, 48% of cases were due to NAC spp. Multivariate logistic regression analysis identified factors associated with a risk of BSI due to NAC spp.: having received a haematologic transplant (OR 10.8; 95% CI 1.31-90.01; p 0.027), previous fluconazole exposure (OR 4.47; 95% CI 2.12-9.43; p <0.001) and neonatal age (OR 4.42; 95% CI 1.63-12.04; p 0.004). Conversely, previous CA colonization (OR 0.33; 95% CI 0.19-0.57; p 0.001) and previous antibiotic use (OR 0.42; 95% CI 0.21-0.85; p 0.017) were associated with CA fungaemia compared to NAC. In conclusion, NAC candidaemia comprised 48% of cases in our series. Predictors of NAC include having received a haematologic transplant, neonatal age and previous fluconazole use.

Kinetics of Photochemical Reactions under Restricted Geometry Conditions

Kinetics of ground state reactions under restricted geometry conditions have been rationalized generally taking as a basis the Pseudophase Model, whose basic hypothesis is: The distribution of the reactants between the pseudophases is at equilibrium, that is, the rate of the reaction is slow in relation to the rates of entry and exit of the reactant to and from the receptor. However, photochemical reactions are generally very rapid, so the following question emerges: is the Pseudophase Model still applicable to photochemical reactions? To answer this question has been the primary objective of this work in which photochemical reactions in micelles, polymers and cyclodextrins have been reviewed. The lifetime of the fluorophore and the distributions of the quencher and the probe are crucial properties; they must be taken into account to obtain a proper description of the behaviour of a given system. The models of Infelta, Almgren and Quina visualise different scenarios with varied combinations of these properties. It is shown that, in some cases, the Pseudophase Model holds at least formally.

Cooperative and noncooperative binding of *Ru(bpy)3(2+) to DNA and SB4.5G dendrimers

The process *Ru(bpy)(3)(2+) + S(2)O(8)(2-) in two different reaction media, the SB4.5G dendrimer and DNA solutions, was studied. In both media, the receptors have anionic characteristics. This fact will produce a binding of the ruthenium complex to the two receptors by attractive electrostatic interactions. On the contrary, the peroxodisulfate ions will be preferentially located in the aqueous solution due to electrostatic repulsions with the receptors. Despite the similarities of the receptors, some differences are observed in these two reaction media. These differences arise from the fact that the binding of the *Ru(bpy)(3)(2+) complex to DNA shows a negative cooperativity, whereas the binding to the dendrimer is noncooperative in character. The anticooperative character of the binding that happens in DNA solutions becomes noncooperative when an electrolyte, NaNO(3), is added to the medium. This is related to a condensation of the salt's counterions on the surface of the DNA which produces a decrease of the equilibrium constant corresponding to the binding of the complex to the receptor. Therefore, it is shown that the ionic strength of the reaction medium exerts a great influence on the cooperative nature of the ligand/receptor binding. This also explains the different behavior observed in DNA and dendrimer solutions.

Passively mode-locked erbium-doped double-clad fiber laser operating at the 322nd harmonic

We report passive mode locking of a soliton erbium-doped double-clad fiber laser operating at the 322nd harmonic of the fundamental cavity frequency. Repetition rates up to 3 GHz have been obtained with pulses of 1 ps duration and 18 pJ of energy. The supermode suppression at the 322nd harmonic is better than 25 dB. In addition, the transition dynamics from a bunched state of pulses to stable harmonic mode locking is presented, revealing a very long time scale.

Reducing costs and operational constraints of dengue vector control by targeting productive breeding places: a multi-country non-inferiority cluster randomized trial

OBJECTIVES

To test the non-inferiority hypothesis that a vector control approach targeting only the most productive water container types gives the same or greater reduction of the vector population as a non-targeted approach in different ecological settings and to analyse whether the targeted intervention is less costly.

METHODS

Cluster randomized trial in eight study sites (Venezuela, Mexico, Peru, Kenya, Thailand, Myanmar, Vietnam, Philippines), with each study area divided into 18-20 clusters (sectors or neighbourhoods) of approximately 50-100 households each. Using a baseline pupal-demographic survey, the most productive container types were identified which produced >or=55% of all Ae. aegypti pupae. Clusters were then paired based on similar pupae per person indices. One cluster from each pair was randomly allocated to receive the targeted vector control intervention; the other received the 'blanket' (non-targeted) intervention attempting to reach all water holding containers.

RESULTS

The pupal-demographic baseline survey showed a large variation of productive container types across all study sites. In four sites the vector control interventions in both study arms were insecticidal and in the other four sites, non-insecticidal (environmental management and/or biological control methods). Both approaches were associated with a reduction of outcome indicators in the targeted and non-targeted intervention arm of the six study sites where the follow up study was conducted (PPI, Pupae per Person Index and BI, Breteau Index). Targeted interventions were as effective as non-targeted ones in terms of PPI. The direct costs per house reached were lower in targeted intervention clusters than in non-targeted intervention clusters with only one exception, where the targeted intervention was delivered through staff-intensive social mobilization.

CONCLUSIONS

Targeting only the most productive water container types (roughly half of all water holding container types) was as effective in lowering entomological indices as targeting all water holding containers at lower implementation costs. Further research is required to establish the most efficacious method or combination of methods for targeted dengue vector interventions.

Quadriceps muscle strength in scoliosis

Quadriceps muscle weakness is an important component of chronic obstructive pulmonary disease (COPD). We hypothesised that quadriceps weakness would also be a feature of restrictive lung disease due to scoliosis. We studied 10 patients with severe scoliosis (median (interquartile range (IQR)) forced expiratory volume in 1 s (FEV(1))() 35.3 (11)% predicted), 10 patients with severe COPD (FEV(1) 26.5 (9.0)% pred) and 10 healthy age-matched adults. We measured quadriceps strength, exercise capacity and analysed quadriceps muscle biopsies for myosin heavy-chain (MyHC) isoform expression and the presence of oxidative stress. Both groups exhibited quadriceps weakness with median (IQR) maximal voluntary contraction force being 46.0 (17.0) kg, 21.5 (21.0) kg and 31.5 (11.0) kg, respectively (p = 0.02 and 0.04, respectively, for each patient group against controls). Oxidative stress was significantly greater in the quadriceps of both restrictive and COPD patients. The scoliosis patients exhibited a decrease in the proportion of MyHC type I compared with controls; median (IQR) 35.3 (18.5)% compared with 47.7 (9.3)%, p = 0.028. The scoliosis patients also showed an increase in MyHC IIx (26.3 (15.5)% compared with 11.3 (13.0)%, p = 0.01. Quadriceps weakness is a feature of severe scoliosis; the similarities between patients with scoliosis and patients with COPD suggest a common aetiology to quadriceps weakness in both conditions.