ABSTRACT
Microbiota, and the plethora of signalling molecules that they generate, are a major driving force that underlies a striking range of inter-individual physioanatomic and behavioural ...consequences for the host organism. Among the bacterial effectors, one finds peptidoglycan, the major constituent of the bacterial cell surface. In the steady-state, fragments of peptidoglycan are constitutively liberated from bacterial members of the gut microbiota, cross the gut epithelial barrier and enter the host system. The fate of these peptidoglycan fragments, and the outcome for the host, depends on the molecular nature of the peptidoglycan, as well the cellular profile of the recipient tissue, mechanism of cell entry, the expression of specific processing and recognition mechanisms by the cell, and the local immune context. At the target level, physiological processes modulated by peptidoglycan are extremely diverse, ranging from immune activation to small molecule metabolism, autophagy and apoptosis. In this review, we bring together a fragmented body of literature on the kinetics and dynamics of peptidoglycan interactions with the mammalian host, explaining how peptidoglycan functions as a signalling molecule in the host under physiological conditions, how it disseminates within the host, and the cellular responses to peptidoglycan.
A comprehensive review of the diverse mechanisms acting in the mammalian host to facilitate the uptake, biodistribution, processing and recognition of the major bacterial cell wall constituent, peptidoglycan, a key microbiome effector molecule influencing host physiology during health and disease.
Export Destinations and Input Prices Bastos, Paulo; Silva, Joana; Verhoogen, Eric
The American economic review,
02/2018, Letnik:
108, Številka:
2
Journal Article
Recenzirano
Odprti dostop
This paper examines the relationship between the destination of exports and the input prices paid by firms, using detailed customs and firm-product-level data from Portugal. Both ordinary least ...squares regressions and an instrumental-variable strategy using exchange-rate movements (interacted with indicators for initial exports) as a source of variation in destinations indicate that exporting to richer countries leads firms to pay higher prices for inputs, other things equal. The results are supportive of what we call the income-based quality-choice channel: selling to richer destinations leads firms to raise the average quality of goods they produce and to purchase higher-quality inputs.
Alzheimer’s disease (AD) is a progressive and neurodegenerative disorder of the cortex and hippocampus, which eventually leads to cognitive impairment. Although the etiology of AD remains unclear, ...the presence of β-amyloid (Aβ) peptides in these learning and memory regions is a hallmark of AD. Therefore, the inhibition of Aβ peptide aggregation has been considered the primary therapeutic strategy for AD treatment. Many studies have shown that resveratrol has antioxidant, anti-inflammatory, and neuroprotective properties and can decrease the toxicity and aggregation of Aβ peptides in the hippocampus of AD patients, promote neurogenesis, and prevent hippocampal damage. In addition, the antioxidant activity of resveratrol plays an important role in neuronal differentiation through the activation of silent information regulator-1 (SIRT1). SIRT1 plays a vital role in the growth and differentiation of neurons and prevents the apoptotic death of these neurons by deacetylating and repressing p53 activity; however, the exact mechanisms remain unclear. Resveratrol also has anti-inflammatory effects as it suppresses M1 microglia activation, which is involved in the initiation of neurodegeneration, and promotes Th2 responses by increasing anti-inflammatory cytokines and SIRT1 expression. This review will focus on the antioxidant and anti-inflammatory neuroprotective effects of resveratrol, specifically on its role in SIRT1 and the association with AD pathophysiology.
What drives export quality? Using Portuguese firm-level data on exports by product and destination market, we find that f.o.b. unit values increase systematically with distance, and tend to be higher ...in shipments to richer nations. These relationships reflect not only the sorting of firms across markets, but also the within-firm variation of unit values across destinations. Within product categories, higher-productivity firms tend to ship greater quantities at higher prices to a given market, consistent with higher quality. In addition, firm productivity tends to magnify the positive effect of distance on within-product unit values, suggesting that high-productivity, high-quality firms are more able to serve difficult markets.
•Midnight plasma melatonin levels are lower in schizophrenia patients than in healthy controls.•Pineal gland enlarged calcifications are more prevalent in schizophrenia patients.•Pineal gland volume ...is apparently smaller in schizophrenia patients.•Melatonin therapy fosters slight improvements of sleep and of antipsychotic Sequels.•Treatment with low-dose melatonin is chronobiotically effective, but for antioxidant purposes higher doses are required.
Melatonin (MLT), the main hormone of the pineal gland (PG), is assumed to support initiation and maintenance of sleep, and a stable sleep-wake cycle, exerting antioxidative and neuroprotective actions. Evidence demonstrates that sleep and circadian rhythm abnormalities are very common in schizophrenia patients. Some imaging studies suggest structural abnormalities of the PG in these patients as well. We aimed to critically appraise the literature on PG imaging and melatonin secretion in schizophrenia patients, in comparison to matched healthy controls, and to review placebo-controlled trials of add-on exogenous MLT treatment in schizophrenia patients. In this systematic review, twenty-nine studies were included. Meta-analytical evaluation of data was possible only for MLT secretion finding that midnight plasma levels were significantly reduced in individuals with schizophrenia as compared to healthy controls (Hedge`s g = 1.32, p < 0.01). Imaging studies demonstrated greater prevalence of enlarged calcifications (>1 cm) of the PG (2 out of 2 computed tomography studies) and smaller PG volume (2 out of 3 magnetic resonance studies) compared with healthy controls. Anatomic and functional abnormalities of the PG were not associated with duration of illness or with treatment factors, maybe suggesting them to be primary characteristics of the disease and genetically based. Add-on MLT treatment leads to a modest improvement of objective and subjective sleep quality, of metabolic adverse effects of antipsychotics, and of tardive dyskinesia symptoms in schizophrenia patients. It remains to be established whether MLT treatment in prodromal phases of the disease could prevent neurostructural abnormalities.
Peptidoglycan, the major structural polymer forming the cell wall of bacteria, is an important mediator of physiological and behavioral effects in mammalian hosts. These effects are frequently linked ...to its translocation from the intestinal lumen to host tissues. However, the modality and regulation of this translocation across the gut barrier has not been precisely addressed. In this study, we characterized the absorption of peptidoglycan across the intestine and its systemic dissemination. We report that peptidoglycan has a distinct tropism for host organs when absorbed via the gut, most notably by favoring access to the brain. We demonstrate that intestinal translocation of peptidoglycan occurs through a microbiota-induced active process. This process is regulated by the parasympathetic pathway via the muscarinic acetylcholine receptors. Together, this study reveals fundamental parameters concerning the uptake of a major microbiota molecular signal from the steady-state gut.
Genetic testing is currently the leading edge of clinical care when it comes to diagnostics. However, many questions remain unanswered even when employing next-generation sequencing techniques due to ...our inability to decode genetic variations and our limited repertoire of available diagnoses. Accordingly, diagnostic yields for current genomic screenings are <50% and fail to provide the whole picture, leaving the remaining patients without a definitive diagnosis. Human phenotypic/disease expression is explained by alterations not only at the genome, but also at the transcriptome, proteome and metabolome levels. These “higher” complexity levels represent at wealth of information, and diagnostic screenings tests at these levels have been shown to significantly improve diagnostic yields in specific populations compared to conventional diagnostic workup or gold standards in use (7–30% increase in diagnostic yields, depending on the population, approach and gold standard being compared against). However, these are not yet routinely available to clinicians. Due to their dynamic and modifiable nature, tapping into data from different omics will improve our understanding of the pathophysiological bases underlying (many yet to characterize) human disorders. We herein review how alterations at these levels (e.g. post-transcriptional and post-translational) may be pathogenic, how such tests may be implemented and in which situations they are of significant utility.
This paper uses international trade data to assess the degree of exposure of Belt and Road economies to China trade shocks. It finds that the growth of China's trade following its internal ...transformation and accession to the WTO significantly impacted the export performance of Belt and Road economies in the period 2000-2015. The increase in China's imports significantly boosted the exports of these economies. However, this effect was attenuated by increased competition from China in export markets. The effects of China's demand shocks were stronger in more upstream industries, while those of competition shocks were stronger in industries that produce goods that are closer to final use. The effects of competition shocks were also relatively stronger in countries that are relatively poorer and geographically closer to China. Building on these findings, the paper documents the current degree of exposure of Belt and Road economies to China trade shocks.
•China's internal transformation impacted the export performance of Belt and Road Economies.•China's growing import demand boosted the exports of Belt and Road economies, but this effect was attenuated by increased competition in export markets.•The impacts of demand shocks were stronger in more upstream industries.•The impacts of competition shocks were stronger in industries that produce goods that are closer to final use, and in countries that are poorer and geographically closer to China.
This study aimed to implement and evaluate the effectiveness of the Teacher's Vocal Health Program in the Municipal Education Network in Campo Grande, MS, in the 2016 school year so as to reduce or ...extinguish the high prevalence of vocal symptoms among teachers.
This is an experimental research with convenience sampling of 48 teachers presenting with vocal symptoms. The Vocal Symptoms Scale was used to collect data, which according to the criteria of the Scientific Advisory Committee of the Medical Outcomes Trust, present proved psychometric properties and is specific to evaluate individuals with vocal alterations. The proposed Vocal Program is considered as a brief intervention one (3 months) and consists of qualification or instruction, as well as application of 5 daily vocal techniques and is controlled through individual monitoring spreadsheets.
The total score average had statistically significant reduction in the experimental group when compared with the control group, which represents a positive effect concerning the program adhesion. The fact that there was no nullity in the subscales (limitations, physical, emotional) means that even submitted to the intervention, the teachers still present with vocal symptoms.
Teacher's Vocal Health Program represents an effective Vocal Health Program model for the teachers.
This study was designed to evaluate a spray-dried multivalent polyclonal antibody preparation (PAP) against lactate-producing bacteria as an alternative to monensin (MON) to control ruminal ...acidification. Holstein cows (677 ± 98 kg) fitted with ruminal cannulas were allocated in an incomplete Latin square design with two 20 days period. Cows were randomly assigned to control (CTL), PAP, or MON treatments. For each period, cows were fed a forage diet in the first 5 days (d-5 to d-1), composed of sugarcane, urea and a mineral supplement, followed by a 74% concentrate diet for 15 days (d 0 to d 14). There were no treatment main effects (
> 0.05) on dry matter intake (DMI) and microbial protein synthesis. However, there was a large peak (
< 0.01) of intake on d 0 (18.29 kg), followed by a large decline on d 1 (3.67 kg). From d2, DMI showed an increasing pattern (8.34 kg) and stabilized around d 8 (12.96 kg). Higher mean pH was measured (
< 0.01) in cattle-fed MON (6.06 vs. PA
= 5.89 and CTL = 5.91). The ruminal NH
-N concentration of CTL-fed cows was lower (
< 0.01) compared to those fed MON or PAP. The molar concentration of acetate and lactate was not affected (
> 0.23) by treatments, but feeding MON increased (
= 0.01) propionate during the first 4 days after the challenge. Feeding MON and PAP reduced (
= 0.01) the molar proportion of butyrate. MON was effective in controlling pH and improved ruminal fermentation of acidosis-induced cows. However, PAP was not effective in controlling acidosis. The acidosis induced by the challenge was caused by the accumulation of SCFAs. Therefore, the real conditions for evaluation of this feed additive were not reached in this experiment, since this PAP was proposed to work against lactate-producing bacteria.
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