Structure, biogenesis and evolution of thylakoid membranes.

Cyanobacteria and chloroplasts of algae and plants harbor specialized thylakoid membranes that convert sunlight into chemical energy. These membranes house photosystems II and I, the vital protein-pigment complexes that drive oxygenic photosynthesis. In the course of their evolution, thylakoid membranes have diversified in structure. However, the core machinery for photosynthetic electron transport remained largely unchanged, with adaptations occurring primarily in the light-harvesting antenna systems. Whereas thylakoid membranes in cyanobacteria are relatively simple they become more complex in algae and plants. The chloroplasts of vascular plants contain intricate networks of stacked grana and unstacked stroma thylakoids. This review provides an in-depth view of thylakoid membrane architectures in phototrophs, and the determinants that shape their forms, as well as presenting recent insights into the spatial organization of their biogenesis and maintenance. Its overall goal is to define the underlying principles that have guided the evolution of these bioenergetic membranes.

Chromosomal evolution, environmental heterogeneity, and migration drive spatial patterns of species richness in Calochortus (Liliaceae).

We used nuclear genomic data and statistical models to evaluate the ecological and evolutionary processes shaping spatial variation in species richness in Calochortus (Liliaceae, 74 spp.). Calochortus occupies diverse habitats in the western United States and Mexico and has a center of diversity in the California Floristic Province, marked by multiple orogenies, winter rainfall, and highly divergent climates and substrates (including serpentine). We used sequences of 294 low-copy nuclear loci to produce a time-calibrated phylogeny, estimate historical biogeography, and test hypotheses regarding drivers of present-day spatial patterns in species number. Speciation and species coexistence require reproductive isolation and ecological divergence, so we examined the roles of chromosome number, environmental heterogeneity, and migration in shaping local species richness. Six major clades-inhabiting different geographic/climatic areas, and often marked by different base chromosome numbers (n = 6 to 10)-began diverging from each other ~10.3 Mya. As predicted, local species number increased significantly with local heterogeneity in chromosome number, elevation, soil characteristics, and serpentine presence. Species richness is greatest in the Transverse/Peninsular Ranges where clades with different chromosome numbers overlap, topographic complexity provides diverse conditions over short distances, and several physiographic provinces meet allowing immigration by several clades. Recently diverged sister-species pairs generally have peri-patric distributions, and maximum geographic overlap between species increases over the first million years since divergence, suggesting that chromosomal evolution, genetic divergence leading to gametic isolation or hybrid inviability/sterility, and/or ecological divergence over small spatial scales may permit species co-occurrence.

Multilayered regulation of developmentally programmed pre-anthesis tip degeneration of the barley inflorescence.

Leaf and floral tissue degeneration is a common feature in plants. In cereal crops such as barley (Hordeum vulgare L.), pre-anthesis tip degeneration (PTD) starts with growth arrest of the inflorescence meristem dome, which is followed basipetally by the degeneration of floral primordia and the central axis. Due to its quantitative nature and environmental sensitivity, inflorescence PTD constitutes a complex, multilayered trait affecting final grain number. This trait appears to be highly predictable and heritable under standardized growth conditions, consistent with a developmentally programmed mechanism. To elucidate the molecular underpinnings of inflorescence PTD, we combined metabolomic, transcriptomic, and genetic approaches to show that barley inflorescence PTD is accompanied by sugar depletion, amino acid degradation, and abscisic acid responses involving transcriptional regulators of senescence, defense, and light signaling. Based on transcriptome analyses, we identified GRASSY TILLERS1 (HvGT1), encoding an HD-ZIP transcription factor, as an important modulator of inflorescence PTD. A gene-edited knockout mutant of HvGT1 delayed PTD and increased differentiated apical spikelets and final spikelet number, suggesting a possible strategy to increase grain number in cereals. We propose a molecular framework that leads to barley PTD, the manipulation of which may increase yield potential in barley and other related cereals.

Metabolomic and transcriptomic analyses of yellow-flowered crocuses to infer alternative sources of saffron metabolites.

BACKGROUND: The increasing demand for saffron metabolites in various commercial industries, including medicine, food, cosmetics, and dyeing, is driven by the discovery of their diverse applications. Saffron, derived from Crocus sativus stigmas, is the most expensive spice, and there is a need to explore additional sources to meet global consumption demands. In this study, we focused on yellow-flowering crocuses and examined their tepals to identify saffron-like compounds. RESULTS: Through metabolomic and transcriptomic approaches, our investigation provides valuable insights into the biosynthesis of compounds in yellow-tepal crocuses that are similar to those found in saffron. The results of our study support the potential use of yellow-tepal crocuses as a source of various crocins (crocetin glycosylated derivatives) and flavonoids. CONCLUSIONS: Our findings suggest that yellow-tepal crocuses have the potential to serve as a viable excessive source of some saffron metabolites. The identification of crocins and flavonoids in these crocuses highlights their suitability for meeting the demands of various industries that utilize saffron compounds. Further exploration and utilization of yellow-tepal crocuses could contribute to addressing the growing global demand for saffron-related products.

Changes in Noradrenergic Synthesis and Dopamine Beta-Hydroxylase Activity in Response to Oxidative Stress after Iron-induced Brain Injury.

Noradrenaline (NA) levels are altered during the first hours and several days after cortical injury. NA modulates motor functional recovery. The present study investigated whether iron-induced cortical injury modulated noradrenergic synthesis and dopamine beta-hydroxylase (DBH) activity in response to oxidative stress in the brain cortex, pons and cerebellum of the rat. Seventy-eight rats were divided into two groups: (a) the sham group, which received an intracortical injection of a vehicle solution; and (b) the injured group, which received an intracortical injection of ferrous chloride. Motor deficits were evaluated for 20 days post-injury. On the 3rd and 20th days, the rats were euthanized to measure oxidative stress indicators (reactive oxygen species (ROS), reduced glutathione (GSH) and oxidized glutathione (GSSG)) and catecholamines (NA, dopamine (DA)), plus DBH mRNA and protein levels. Our results showed that iron-induced brain cortex injury increased noradrenergic synthesis and DBH activity in the brain cortex, pons and cerebellum at 3 days post-injury, predominantly on the ipsilateral side to the injury, in response to oxidative stress. A compensatory increase in contralateral noradrenergic activity was observed, but without changes in the DBH mRNA and protein levels in the cerebellum and pons. In conclusion, iron-induced cortical injury increased the noradrenergic response in the brain cortex, pons and cerebellum, particularly on the ipsilateral side, accompanied by a compensatory response on the contralateral side. The oxidative stress was countered by antioxidant activity, which favored functional recovery following motor deficits.

Coronary microvascular dysfunction is associated with impaired cognitive function: the Cerebral-Coronary Connection study (C3 study).

BACKGROUND: It remains unknown whether the presence of coronary microcirculatory dysfunction (CMD) correlates with its equivalent condition in the brain, cerebral small vessel disease (CSVD). The cerebral-coronary connection (C3), a prospective blinded study, investigated the prevalence of CMD in patients with coronary artery disease (CAD) and its association with CSVD and cognitive function. METHODS AND RESULTS: Patients with documented CAD fulfilling inclusion criteria underwent physiological assessment of epicardial vessels and the microcirculation using intracoronary pressure and Doppler. Coronary microcirculation-related indices included coronary flow reserve (CFR) and hyperaemic microvascular resistance. Brain magnetic resonance imaging, transcranial Doppler (TCD), and neurocognitive examination were performed. Overall, 67 patients were included in the study (mean age 66 years, 73% female). Patients with abnormal CFR (<2.0) (55.2%) showed higher burden of white-matter hyperintensities: 43.2 vs. 20.0% (P = 0.044). After statistical adjustment, low CFR was associated with lower grey matter volume (P = 0.024) and with parameters of white-matter microstructural damage in diffusion-tensor imaging (lower fractional anisotropy and higher mean diffusivity, P = 0.029 and P = 0.032, respectively). Low CFR was associated with higher resistive (P = 0.027) and pulsatility (P = 0.043) values on TCD, and worse neurocognitive test scores (lower mini mental state examination, P = 0.025, and slower Trail Making Test A, P = 0.034). CONCLUSIONS: Coronary microcirculatory dysfunction is frequent in patients with CAD and correlates with CSVD, abnormal cerebral flow haemodynamics, and significant cognitive impairment. These findings support the hypothesis that microvascular dysfunction in the heart and the brain are part of a single pathological process affecting microcirculation in patients with CAD. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT04131075.

How do barley plants with impaired photosynthetic light acclimation survive under high-light stress?

MAIN CONCLUSION: WHIRLY1 deficient barley plants surviving growth at high irradiance displayed increased non-radiative energy dissipation, enhanced contents of zeaxanthin and the flavonoid lutonarin, but no changes in α-tocopherol nor glutathione. Plants are able to acclimate to environmental conditions to optimize their functions. With the exception of obligate shade plants, they can adjust their photosynthetic apparatus and the morphology and anatomy of their leaves to irradiance. Barley (Hordeum vulgare L., cv. Golden Promise) plants with reduced abundance of the protein WHIRLY1 were recently shown to be unable to acclimatise important components of the photosynthetic apparatus to high light. Nevertheless, these plants did not show symptoms of photoinhibition. High-light (HL) grown WHIRLY1 knockdown plants showed clear signs of exposure to excessive irradiance such as a low epoxidation state of the violaxanthin cycle pigments and an early light saturation of electron transport. These responses were underlined by a very large xanthophyll cycle pool size and by an increased number of plastoglobules. Whereas zeaxanthin increased with HL stress, α-tocopherol, which is another lipophilic antioxidant, showed no response to excessive light. Also the content of the hydrophilic antioxidant glutathione showed no increase in W1 plants as compared to the wild type, whereas the flavone lutonarin was induced in W1 plants. HPLC analysis of removed epidermal tissue indicated that the largest part of lutonarin was presumably located in the mesophyll. Since lutonarin is a better antioxidant than saponarin, the major flavone present in barley leaves, it is concluded that lutonarin accumulated as a response to oxidative stress. It is also concluded that zeaxanthin and lutonarin may have served as antioxidants in the WHIRLY1 knockdown plants, contributing to their survival in HL despite their restricted HL acclimation.

Putative adaptive loci show parallel clinal variation in a California-endemic wildflower.

As the global climate crisis continues, predictions concerning how wild populations will respond to changing climate conditions are informed by an understanding of how populations have responded and/or adapted to climate variables in the past. Changes in the local biotic and abiotic environment can drive differences in phenology, physiology, morphology and demography between populations leading to local adaptation, yet the molecular basis of adaptive evolution in wild non-model organisms is poorly understood. We leverage comparisons between two lineages of Calochortus venustus occurring along parallel transects that allow us to identify loci under selection and measure clinal variation in allele frequencies as evidence of population-specific responses to selection along climatic gradients. We identify targets of selection by distinguishing loci that are outliers to population structure and by using genotype-environment associations across transects to detect loci under selection from each of nine climatic variables. Despite gene flow between individuals of different floral phenotypes and between populations, we find evidence of ecological specialization at the molecular level, including genes associated with key plant functions linked to plant adaptation to California's Mediterranean climate. Single-nucleotide polymorphisms (SNPs) present in both transects show similar trends in allelic similarity across latitudes indicating parallel adaptation to northern climates. Comparisons between eastern and western populations across latitudes indicate divergent genetic evolution between transects, suggesting local adaptation to either coastal or inland habitats. Our study is among the first to show repeated allelic variation across climatic clines in a non-model organism.

Films of biopolymers, pectin and gellan, enriched with natamycin and clove essential oils for the packaging of Corn tortilla: Protection against Staphylococcus aureus and Candida parapsilosis.

It was investigated the microbial protection of corn tortilla, traditional Mexican food with high acceptance, for food safety. We elaborated a functional film (FF) prepared with 0.4% (w/v) gellan gum, 2% (w/v) citrus pectin, 0.5% (w/v) glycerol, 0.0003% (w/v) natamycin, 0.03% (v/v) essential clove oils, and 0.1% (v/v) tween 80. The FF impeded the growth of indicator microorganisms in corn tortilla medium: Staphylococcus aureus (i.e., 35 °C, 50% RH, 7 days) and Candida parapsilosis (i.e., 27 °C, 42% RH, 7 days; and 9 °C, 95% RH, 30 days). In packaged artisanal corn tortilla storage at 22 °C and 50% RH for 30 days, the FF-treatments showed 5.5 log CFU/g total aerobes and 4.8 log CFU/g yeasts and moulds, being two and three logs lower than the concentrations recorded in the controls with no film, respectively. Some physical-mechanical properties of FF were Young's modulus, 500 MPa; elongation at break, 10%; stress at break, 18.5 MPa; oxygen permeability, 4 × 10-13 g m Pa-1 s-1 m-2; and water vapour permeability, 4.8 × 10-11 g m Pa-1 s-1 m-2. Also, the sensory evaluation of wrapped tortilla suggested no negative effects. The obtained results envisage potential food-packaging applications with the elaborated films.

Gut Microbiota and Derived Short-Chain Fatty Acids Are Linked to Evolution of Heart Failure Patients.

There is a lack of direct evidence regarding gut microbiota dysbiosis and changes in short-chain fatty acids (SCFAs) in heart failure (HF) patients. We sought to assess any association between gut microbiota composition, SCFA production, clinical parameters, and the inflammatory profile in a cohort of newly diagnosed HF patients. In this longitudinal prospective study, we enrolled eighteen newly diagnosed HF patients. At admission and after 12 months, blood samples were collected for the assessment of proinflammatory cytokines, monocyte populations, and endothelial dysfunction, and stool samples were collected for analysis of gut microbiota composition and quantification of SCFAs. Twelve months after the initial HF episode, patients demonstrated improved clinical parameters and reduced inflammatory state and endothelial dysfunction. This favorable evolution was associated with a reversal of microbiota dysbiosis, consisting of the increment of health-related bacteria, such as genus Bifidobacterium, and levels of SCFAs, mainly butyrate. Furthermore, there was a decrease in the abundance of pathogenic bacteria. In vitro, fecal samples collected after 12 months of follow-up exhibited lower inflammation than samples collected at admission. In conclusion, the favorable progression of HF patients after the initial episode was linked to the reversal of gut microbiota dysbiosis and increased SCFA production, particularly butyrate. Whether restoring butyrate levels or promoting the growth of butyrate-producing bacteria could serve as a complementary treatment for these patients deserves further studies.

Antibacterial and Cytotoxic Study of Hybrid Films Based on Polypropylene and NiO or NiFe2O4 Nanoparticles.

This study presents an in vitro analysis of the bactericidal and cytotoxic properties of hybrid films containing nickel oxide (NiO) and nickel ferrite (NiFe2O4) nanoparticles embedded in polypropylene (PP). The solvent casting method was used to synthesize films of PP, PP@NiO, and PP@NiFe2O4, which were characterized by different spectroscopic and microscopic techniques. The X-ray diffraction (XRD) patterns confirmed that the small crystallite sizes of NiO and NiFe2O4 NPs were maintained even after they were incorporated into the PP matrix. From the Raman scattering spectroscopy data, it was evident that there was a significant interaction between the NPs and the PP matrix. Additionally, the Scanning Electron Microscopy (SEM) analysis revealed a homogeneous dispersion of NiO and NiFe2O4 NPs throughout the PP matrix. The incorporation of the NPs was observed to alter the surface roughness of the films; this behavior was studied by atomic force microscopy (AFM). The antibacterial properties of all films were evaluated against Pseudomonas aeruginosa (ATCC®: 43636™) and Staphylococcus aureus (ATCC®: 23235™), two opportunistic and nosocomial pathogens. The PP@NiO and PP@ NiFe2O4 films showed over 90% bacterial growth inhibition for both strains. Additionally, the effects of the films on human skin cells, such as epidermal keratinocytes and dermal fibroblasts, were evaluated for cytotoxicity. The PP, PP@NiO, and PP@NiFe2O4 films were nontoxic to human keratinocytes. Furthermore, compared to the PP film, improved biocompatibility of the PP@NiFe2O4 film with human fibroblasts was observed. The methodology utilized in this study allows for the production of hybrid films that can inhibit the growth of Gram-positive bacteria, such as S. aureus, and Gram-negative bacteria, such as P. aeruginosa. These films have potential as coating materials to prevent bacterial proliferation on surfaces.

Depression and Anxiety Are Common Among Patients With Cirrhosis.

BACKGROUND & AIMS: Depression and anxiety can have negative effects on patients and are important to treat. There have been few studies of their prevalence among patients with cirrhosis. We aimed to characterize the prevalence and risk factors for depression and anxiety in a large multi-center cohort of patients with cirrhosis. METHODS: We conducted a telephone-based survey of patients with cirrhosis at 3 health systems in the United States (a tertiary-care referral center, a safety net system, and a Veterans hospital) from April through December 2018. Of 2871 patients approached, 1021 (35.6%) completed the survey. Depression and anxiety were assessed using the PHQ-9 (range 0-25) and STAI (range 20-80) instruments, with clinically significant values defined as PHQ-9 ≥15 and STAI ≥40. We performed multivariate logistic regression analysis to identify factors associated with significant depression and anxiety. RESULTS: The median PHQ-9 score was 7 (25th percentile-75th percentile, 3-12) and the median STAI score was 33 (25th percentile-75th percentile, 23-47); 15.6% of patients had moderately severe to severe depression and 42.6% of patients had high anxiety. In multivariable analyses, self-reported poor health (odds ratio [OR], 4.08; 95% CI, 1.79-9.28), being widowed (OR, 2.08; 95% CI, 1.07-4.05), fear of hepatocellular carcinoma (OR, 1.89; 95% CI, 1.04-3.42), higher household income (OR, 0.30; 95% CI, 0.10-0.95), and Hispanic ethnicity (OR, 0.57; 95% CI, 0.33-0.97) were associated with moderately severe to severe depression. Male sex (OR, 0.71; 95% CI, 0.51-0.98), self-reported poor health (OR, 2.73; 95% CI, 1.73-4.32), and fear of hepatocellular carcinoma (OR, 2.24; 95% CI, 1.33-3.78) were associated with high anxiety. CONCLUSIONS: Nearly 1 in 6 patients with cirrhosis have moderately severe to severe depression and nearly half have moderate-severe anxiety. Patients with cirrhosis should be evaluated for both of these disorders.

Unraveling metabolic patterns and molecular mechanisms underlying storability in sugar beet.

BACKGROUND: Sugar beet is an important crop for sugar production. Sugar beet roots are stored up to several weeks post-harvest waiting for processing in the sugar factories. During this time, sucrose loss and invert sugar accumulation decreases the final yield and processing quality. To improve storability, more information about post-harvest metabolism is required. We investigated primary and secondary metabolites of six sugar beet varieties during storage. Based on their variety-specific sucrose loss, three storage classes representing well, moderate, and bad storability were compared. Furthermore, metabolic data were visualized together with transcriptome data to identify potential mechanisms involved in the storage process. RESULTS: We found that sugar beet varieties that performed well during storage have higher pools of 15 free amino acids which were already observable at harvest. This storage class-specific feature is visible at harvest as well as after 13 weeks of storage. The profile of most of the detected organic acids and semi-polar metabolites changed during storage. Only pyroglutamic acid and two semi-polar metabolites, including ferulic acid, show higher levels in well storable varieties before and/or after 13 weeks of storage. The combinatorial OMICs approach revealed that well storable varieties had increased downregulation of genes involved in amino acid degradation before and after 13 weeks of storage. Furthermore, we found that most of the differentially genes involved in protein degradation were downregulated in well storable varieties at both timepoints, before and after 13 weeks of storage. CONCLUSIONS: Our results indicate that increased levels of 15 free amino acids, pyroglutamic acid and two semi-polar compounds, including ferulic acid, were associated with a better storability of sugar beet taproots. Predictive metabolic patterns were already apparent at harvest. With respect to elongated storage, we highlighted the role of free amino acids in the taproot. Using complementary transcriptomic data, we could identify potential underlying mechanisms of sugar beet storability. These include the downregulation of genes for amino acid degradation and metabolism as well as a suppressed proteolysis in the well storable varieties.

A Wearable System Based on Multiple Magnetic and Inertial Measurement Units for Spine Mobility Assessment: A Reliability Study for the Evaluation of Ankylosing Spondylitis.

Spinal mobility assessment is essential for the diagnostic of patients with ankylosing spondylitis. BASMI is a routine clinical evaluation of the spine; its measurements are made with goniometers and tape measures, implying systematic errors, subjectivity, and low sensitivity. Therefore, it is crucial to develop better mobility assessment methods. The design, implementation, and evaluation of a novel system for assessing the entire spine's motion are presented. It consists of 16 magnetic and inertial measurement units (MIMUs) communicated wirelessly with a computer. The system evaluates the patient's movements by implementing a sensor fusion of the triaxial gyroscope, accelerometer, and magnetometer signals using a Kalman filter. Fifteen healthy participants were assessed with the system through six movements involving the entire spine to calculate continuous kinematics and maximum range of motion (RoM). The intrarater reliability was computed over the observed RoM, showing excellent reliability levels (intraclass correlation >0.9) in five of the six movements. The results demonstrate the feasibility of the system for further clinical studies with patients. The system has the potential to improve the BASMI method. To the best of our knowledge, our system involves the highest number of sensors, thus providing more objective information than current similar systems.

Microglial CX3CR1 production increases in Alzheimer's disease and is regulated by noradrenaline.

The loss of noradrenergic neurons and subsequent reduction of brain noradrenaline (NA) levels are associated with the progression of Alzheimer's disease (AD). This seems to be due mainly to the ability of NA to reduce the activation of microglial cells. We previously observed that NA induces the production of the chemokine Fractalkine/CX3CL1 in neurons. The activation of microglial CX3CR1, sole receptor for CX3CL1, reduces the activation of microglia, which is known to largely contribute to the neuronal damage characteristic of AD. Therefore, alterations of CX3CR1 production in microglia could translate into the enhancement or inhibition of CX3CL1 anti-inflammatory effects. In order to determine if microglial CX3CR1 production is altered in AD and if NA can control it, CX3CR1 expression and synthesis were analyzed in 5xFAD mice and human AD brain samples. In addition, the effects of NA and its reuptake inhibitor reboxetine were analyzed in microglial cultures and mice respectively. Our results indicate that in AD CX3CR1 production is increased in the brain cortex and that reboxetine administration further increases it and enhances microglial reactivity toward amyloid beta plaques. However, direct administration of NA to primary rat microglia or human HMC3 cells inhibits CX3CR1 production, suggesting that microglia responses to NA may be altered in the absence of CX3CL1-producing neurons or other nonmicroglial external factors.

Untargeted metabotyping to study phenylpropanoid diversity in crop plants.

Plant genebanks constitute a key resource for breeding to ensure crop yield under changing environmental conditions. Because of their roles in a range of stress responses, phenylpropanoids are promising targets. Phenylpropanoids comprise a wide array of metabolites; however, studies regarding their diversity and the underlying genes are still limited for cereals. The assessment of barley diversity via genotyping-by-sequencing is in rapid progress. Exploring these resources by integrating genetic association studies to in-depth metabolomic profiling provides a valuable opportunity to study barley phenylpropanoid metabolism; but poses a challenge by demanding large-scale approaches. Here, we report an LC-PDA-MS workflow for barley high-throughput metabotyping. Without prior construction of a species-specific library, this method produced phenylpropanoid-enriched metabotypes with which the abundance of putative metabolic features was assessed across hundreds of samples in a single-processed data matrix. The robustness of the analytical performance was tested using a standard mix and extracts from two selected cultivars: Scarlett and Barke. The large-scale analysis of barley extracts showed (1) that barley flag leaf profiles were dominated by glycosylation derivatives of isovitexin, isoorientin, and isoscoparin; (2) proved the workflow's capability to discriminate within genotypes; (3) highlighted the role of glycosylation in barley phenylpropanoid diversity. Using the barley S42IL mapping population, the workflow proved useful for metabolic quantitative trait loci purposes. The protocol can be readily applied not only to explore the barley phenylpropanoid diversity represented in genebanks but also to study species whose profiles differ from those of cereals: the crop Helianthus annuus (sunflower) and the model plant Arabidopsis thaliana.

Toward understanding the signals of bacteriocin production by Streptococcus spp. and their importance in current applications.

Microorganisms have developed quorum sensing (QS) systems to detect small signaling molecules that help to control access to additional nutrients and space in highly competitive polymicrobial niches. Many bacterial processes are QS-regulated; two examples are the highly related traits of the natural genetic competence state and the production of antimicrobial peptides such as bacteriocins. The Streptococcus genus is widely studied for its competence and for its ability to produce bacteriocins, as these antimicrobial peptides have significant potential in the treatment of infections caused by multiple-resistant pathogens, a severe public health issue. The transduction of a two-component system controls competence in streptococci: (1) ComD/E, which controls the competence in the Mitis and Anginosus groups, and (2) ComR/S, which performs the same function in the Bovis, Mutans, Salivarius, and Pyogenic groups. The cell-to-cell communication required for bacteriocin production in the Streptococcus groups is controlled mainly by a paralog of the ComD/E system. The relationships between pheromone signals and induction pathways are related to the bacteriocin production systems. In this review, we discuss the recent advances in the understanding of signaling and the induction of bacteriocin biosynthesis by QS regulation in streptococci. This information could aid in the design of better methods for the development and production of these antimicrobial peptides. It could also contribute to the analysis and emerging applications of bacteriocins in terms of their safety, quality, and human health benefits.

Pectin-gellan films intended for active food packaging: release kinetics of nisin and physico-mechanical characterization.

Films were prepared by casting 2% w/v apple pectin, 0.5% w/v low-acyl gellan and 2.2% w/v glycerol as plasticizer. Bioactive film (BF, films with 3912 International Units (IU) nisin/cm2) and control films (CF, films without nisin) were elaborated. The objective was to analyze the release kinetics of nisin from films to a food model, to determine the period of film bioactivity and potential use as antimicrobial packaging. The release of nisin from BF to a food model was determined at 5 °C and 30 °C. The release kinetics of nisin was fitted to the analytical solution of the Fick's second law for an infinite plate. The diffusion coefficients of nisin (D) were 5.22 × 10-14 and 7.36 × 10-14 m2/s for 5 °C and 30 °C, respectively. Besides, both films were characterized in their mechanical properties and gas permeabilities [oxygen (PO2) and water vapour permeability (WVP)]. The mechanical properties were reduced by the nisin incorporation, whereas PO2 was increased, and no significant effect on WVP was observed.

Advances in infrared thermography: Surgical aspects, vascular changes, and pain monitoring in veterinary medicine.

One of the main functions of infrared thermography (IRT) consists in detecting temperature changes in organisms caused by variations in surface blood circulation. IRT is a useful tool that has been used mainly as a diagnostic method for various stress-causing pathologies, though recent suggestions indicate that it can be used to assess the block quality of certain body regions. In the field of anaesthesiology, IRT has been applied to brachial and epidural blocks, while in algology, changes in surface blood circulation associated with sympathetic activity have been investigated. Thermography has also been employed to complement pain level scales based on the facial expressions of patients in critical condition, or after surgery. In addition, it has been used as a tool in research designed to evaluate different surgical procedures in human medicine, as in the case of surgical burrs for placing dental implants, where IRT helps assess the degree of heating associated with bone devascularisation, reduction in vascular perfusion as a consequence of stroke, and changes in the autonomous nervous system, or the degree of vascular changes in flaps applied to burn patients. In veterinary medicine, thermography has brought several benefits for animals in terms of evaluating lesions, diseases, and surgical procedures. The aim of this review is to evaluate how IRT can be used as a tool in surgical procedures, cases of vascular change, and pain monitoring in veterinary medicine with an emphasis on small animals.

Alterations in cardiovascular function in an experimental model of lung fibrosis and pulmonary hypertension.

NEW FINDINGS: What is the central question of this study? We have evaluated changes in cardiovascular physiology using echocardiography in an experimental model of lung fibrosis. What is the main finding and its importance? Remarkably, we report changes in cardiovascular function as early as day 7, concomitant with evidence of vascular remodelling. We also report that isolated pulmonary arteries were hypercontractile in response to a thromboxane A2 agonist. These findings are significant because the development of pulmonary hypertension is one of the most significant predictors of mortality in patients with lung fibrosis, where there are no available therapies and a lack of animal models. ABSTRACT: Group III pulmonary hypertension is observed in patients with chronic lung diseases such as chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis. Pulmonary hypertension (PH) develops as a result of extensive pulmonary vascular remodelling and resultant changes in vascular tone that can lead to right ventricle hypertrophy. This eventually leads to right heart failure, which is the leading indicator of mortality in patients with idiopathic pulmonary fibrosis. Treatments for group III PH are not available, in part owing to a lack of viable animal models. Here, we have evaluated the cardiovascular changes in a model of lung fibrosis and PH. Data obtained from this study indicated that structural alterations in the right heart, such as right ventricular wall hypertrophy, occurred as early as day 14, and similar increases in right ventricle chamber size were seen between days 21 and 28. These structural changes were correlated with decreases in the systolic function of the right ventricle and right ventricular cardiac output, which also occurred between the same time points. Characterization of pulmonary artery dynamics also highlighted that PH might be occurring as early as day 21, indicated by reductions in the velocity-time integral; however, evidence for PH is apparent as early as day 7, indicated by the significant reduction in pulmonary acceleration time values. These changes are consistent with evidence of vascular remodelling observed histologically starting on day 7. In addition, we report hyperactivity of bleomycin-exposed pulmonary arteries to a thromboxane A2 receptor (Tbxa2r) agonist.