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Mycotoxins are secondary metabolites produced by fungi with harmful effects such as carcinogenicity, teratogenicity, nephrotoxicity, and hepatotoxicity. They cause widespread contamination of plant products such as crops, food, and feed, posing serious threats to the life and health of human beings and animals. It has been found that many traditionally synthesized and natural compounds are capable of inhibiting the growth of fungi and their secondary metabolite production. Natural compounds have attracted much attention due to their safety, environmental, and health friendly features. In this paper, compounds of plant origin with inhibitory effects on ochratoxins, aflatoxins, Fusarium toxins, and Alternaria toxins, including cinnamaldehyde, citral, magnolol, eugenol, pterostilbene, curcumin, and phenolic acid, are reviewed, and the inhibitory mechanisms of different compounds on the toxin production of fungi are also elucidated, with the aim of providing application references to reduce the contamination of fungal toxins, thus safeguarding the health of human beings and animals. [ABSTRACT FROM AUTHOR]

CRISPR–Cas systems are known to be part of the bacterial adaptive immune system that provides resistance against intruders such as viruses, phages and other mobile genetic elements. To combat this bacterial defense mechanism, phages encode inhibitors called Acrs (anti-CRISPR proteins) that can suppress them. AcrIC9 is the most recently identified member of the AcrIC family that inhibits the type IC CRISPR–Cas system. Here, the crystal structure of AcrIC9 from Rhodobacter capsulatus is reported, which comprises a novel fold made of three central antiparallel β-strands surrounded by three α-helixes, a structure that has not been detected before. It is also shown that AcrIC9 can form a dimer via disulfide bonds generated by the Cys69 residue. Finally, it is revealed that AcrIC9 directly binds to the type IC cascade. Analysis and comparison of its structure with structural homologs indicate that AcrIC9 belongs to DNA-mimic Acrs that directly bind to the cascade complex and hinder the target DNA from binding to the cascade.

This work was aimed to investigate the α-glucosidase inhibitory potential of methanol, petroleum ether, ethyl acetate, n-butanol, and water extracts/fractions of four Dendrobium species, which are traditional medicinal plants over the centuries, and discovery some important polyphenols in terms of lowering blood sugar based our previous research. Furthermore, the enzyme kinetics, HPLC, fluorescence spectra, and molecular docking were performed to provide additional insights into the binding mechanisms between individual polyphenol and α-glucosidase. All the organic extracts/fractions showed promising results on α-glucosidase with IC50 values of 4.23–52.53 μg/mL. The EtOAcF of D. chrysotoxum (EtOAcF-DC) possessed the lowest IC50 value (4.23 ± 0.19 μg/mL) against α-glucosidase. And an obvious correlation existed between the total phenol contents and α-glucosidase inhition capacity. Schaftoside, isoschaftoside, 2,4,7-trihydroxy-9,10-dihydrophenanthrene (TD), dihydroresveratrol, coelonin, nudol (NU), gigantol (GT), erianin, and tristin were identified as the main polyphenol components in these four Dendrobium plants. However, only TD, NU, coelonin, and GT had significant inhibitory activity on α-glucosidase. TD, NU and GT were discovered simultaneously in the EtOAc fractions (EtOAcFs) of the four Dendrobium species and occupied higher contents than other components, thus being selected as objectives for deep research. The TD from Dendrobium species was first reported as α-glucosidase inhibitor with an IC50 value of 52.46 ± 2.34 μg/mL, which was almost 6.5 times stronger than that of acarbose (IC50 = 338.84 ± 18.57 μg/mL), signifying it was a potential candidate for treating diabetes. NU and GT acted as uncompetitive inhibitors against α-glucosidase, while TD and EtOAcF-DC exhibited mixed-type inhibition. The fluorescence spectra analysis demonstrated that these inhibitors could quenched the fluorescence spectrum of α-glucosidase significantly. Interestingly, the NU quenched fluorescence by an unusual static quenching method. The molecular simulation illustrated these three polyphenols interacted with α-glucosidase primarily through hydrogen bonds and van der Waals interactions, and the binding sites between polyphenols and α-glucosidase supported the obtained results of inhibition kinetics. This study revealed that the phenolic-rich extracts/fractions and polyphenol compounds from Dendrobium plants could be potential α-glucosidase inhibitors.

In order to effectively inhibit the explosion of titanium powder, this study used the Hartmann tube experimental system and the 20 L explosion tank experimental system to carry out flame propagation and explosion overpressure experiments, respectively, and the effect of NH4H2PO4 on the explosion suppression of titanium powder was studied. The results show that when the addition of NH4H2PO4 powder is 50%, the flame propagation velocity and explosion pressure can be reduced to the minimum, and the explosion pressure can be basically suppressed. Finally, the inhibition mechanism of NH4H2PO4 on the explosion of titanium powder was analyzed. The endothermic decomposition of NH4H2PO4 absorbed the energy needed by the explosion of titanium powder. Oxides produced by the decomposition of NH4H2PO4 powder cover the surface of titanium powder, increase the thickness of the oxide film, and play a role of heat insulation; the gaseous water produced by the decomposition of NH4H2PO4 powder reduces the concentration of oxygen in the air and increases the difficulty of the explosion reaction. NH4H2PO4 powder traps the free radicals needed for the explosion to block the chain reaction. [ABSTRACT FROM AUTHOR]

Plant byproducts and waste present enormous environmental challenges and an opportunity for valorization and industrial application. Due to consumer demands for natural compounds, the evident paucity of novel antimicrobial agents against foodborne pathogens, and the urgent need to improve the arsenal against infectious diseases and antimicrobial resistance (AMR), plant byproduct compounds have attracted significant research interest. Emerging research highlighted their promising antimicrobial activity, yet the inhibitory mechanisms remain largely unexplored. Therefore, this review summarizes the overall research on the antimicrobial activity and inhibitory mechanisms of plant byproduct compounds. A total of 315 natural antimicrobials from plant byproducts, totaling 1338 minimum inhibitory concentrations (MIC) (in μg/mL) against a broad spectrum of bacteria, were identified, and a particular emphasis was given to compounds with high or good antimicrobial activity (typically <100 μg/mL MIC). Moreover, the antimicrobial mechanisms, particularly against bacterial pathogens, were discussed in‐depth, summarizing the latest research on using natural compounds to combat pathogenic microorganisms and AMR. Furthermore, safety concerns, relevant legislation, consumer perspective, and current gaps in the valorization of plant byproducts–derived compounds were comprehensively discussed. This comprehensive review covering up‐to‐date information on antimicrobial activity and mechanisms represents a powerful tool for screening and selecting the most promising plant byproduct compounds and sources for developing novel antimicrobial agents. [ABSTRACT FROM AUTHOR]

An upward trend in the incidence of Parkinson’s disease (PD), known as one of the most prominent neurodegenerative maladies, has evoked great concerns among medical community over the past decades. Recently, studies have suggested the initiation of PD in the gastrointestinal tract decades before the advent of manifestations. Accumulating evidence suggests that intracellular deposition of α-synuclein (α-syn) in patients with PD is associated with systemic inflammation leading to the neuroinflammation and neuropsychiatric disorders. The α-syn protein accumulation can be initiated from GI cells and distribute into CNS cells through trans-synaptic cell to cell transmission. Without doubt, gut microbiota affects the enteric nervous system (ENS) known as the “second brain”. Patients with PD have a different balance of bacteria in their intestines, as compared to healthy population. Metabolites from gut microbiota affect the enteric wall such as neurodegeneration. Probiotics have a substantial role in the neutralization or inhibition of reactive oxygen species (ROS) and free radicals and thus improve the PD symptoms. The anti-inflammatory role of probiotics also inhibits the neurodegeneration and PD development. Hence, probiotics contribute to the improvement of PD through several mechanisms which need more in-depth verification.

Pomegranate peel (PoP) contains plenty of bioactive compounds and exhibits strong activity to prevent postprandial hyperglycaemia and improve diabetes mellitus. Presently, bioaffinity ultrafiltration coupled with high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS/MS) is employed to screen and identify the efficient α-glucosidase inhibitors in PoP and the detailed inhibitory mechanisms are further investigated. The results show that many substances, including ellagic acid, kaempferol, gallic acid, and resveratrol in PoP reveal strong activity to inhibit α-glucosidase and ellagic acid (EA) is screened as the most effective compound. Further research indicates that EA plays a competitive and reversible inhibition role against α-glucosidase with the value of Ki was 6.24 × 105 mol/L. EA also directly interacts with the amino acids of α-glucosidase mainly via van der Waals forces and hydrogen bonds, thereby, influencing the secondary structure and stability of α-glucosidase. Finally, the α-glucosidase inhibitory activity of EA is further confirmed to significantly reduce postprandial blood glucose in vivo.

Abstract The effectiveness of silver nanomaterials (AgNMs), as antiviral agents, has been confirmed in humans against many different types of viruses. Nanobiocides-based AgNMs can be effectively applied to eliminate coronaviruses (CoVs), as the cause of various diseases in animals and humans, particularly the fatal human respiratory infections. Mostly, these NMs act effectively against CoVs, thanks to the NMs’ fundamental anti-viral structures like reactive oxygen species (ROS), and photo-dynamic and photo-thermal abilities. Particularly, the antiviral activity of AgNMs is clarified under three inhibitory mechanisms including viral entry limitation, attachment inhibition, and viral replication limitation. It is believed that nanobiocide with other possible materials such as TiO2, silica and, carbon NMs exclusively nano-graphene materials can emerge as a more effective disinfectant for long-term stability with low toxicity than common disinfectants. Nanobiocides also can be applied for the prevention and treatment of viral infections specifically against COVID-19. Graphic Abstract

Purpose of Review: Until the last 5 years, there was very little in the literature about the phenomenon now known as visual snow syndrome. This review will examine the current thinking on the pathology of visual snow and how that thinking has evolved. Recent Findings: While migraine is a common comorbidity to visual snow syndrome, evidence points to these conditions being distinct clinical entities, with some overlapping pathophysiological processes. There is increasing structural and functional evidence that visual snow syndrome is due to a widespread cortical dysfunction. Cortical hyperexcitability coupled with changes in thalamocortical pathways and higher-level salience network controls have all shown differences in patients with visual snow syndrome compared to controls. Summary: Further work is needed to clarify the exact mechanisms of visual snow syndrome. Until that time, treatment options will remain limited. Clinicians having a clearer understanding of the basis for visual snow syndrome can appropriately discuss the diagnosis with their patients and steer them towards appropriate management options. [ABSTRACT FROM AUTHOR]

Negation is known to have inhibitory consequences for the information under its scope. However, how it produces such effects remains poorly understood. Recently, it has been proposed that negation processing might be implemented at the neural level by the recruitment of inhibitory and cognitive control mechanisms. On this line, this manuscript offers the hypothesis that negation reuses general-domain mechanisms that subserve inhibition in other non-linguistic cognitive functions. The first two sections describe the inhibitory effects of negation on conceptual representations and its embodied effects, as well as the theoretical foundations for the reuse hypothesis. The next section describes the neurophysiological evidence that linguistic negation interacts with response inhibition, along with the suggestion that both functions share inhibitory mechanisms. Finally, the manuscript concludes that the functional relation between negation and inhibition observed at the mechanistic level could be easily integrated with predominant cognitive models of negation processing. [ABSTRACT FROM AUTHOR]

The effectiveness of silver nanomaterials (AgNMs), as antiviral agents, has been confirmed in humans against many different types of viruses. Nanobiocides-based AgNMs can be effectively applied to eliminate coronaviruses (CoVs), as the cause of various diseases in animals and humans, particularly the fatal human respiratory infections. Mostly, these NMs act effectively against CoVs, thanks to the NMs' fundamental anti-viral structures like reactive oxygen species (ROS), and photo-dynamic and photo-thermal abilities. Particularly, the antiviral activity of AgNMs is clarified under three inhibitory mechanisms including viral entry limitation, attachment inhibition, and viral replication limitation. It is believed that nanobiocide with other possible materials such as TiO2, silica and, carbon NMs exclusively nano-graphene materials can emerge as a more effective disinfectant for long-term stability with low toxicity than common disinfectants. Nanobiocides also can be applied for the prevention and treatment of viral infections specifically against COVID-19. [ABSTRACT FROM AUTHOR]

Though there is agreement on the description, incidence and main neuroanatomical findings in Attention Deficit Hyperactivity Disorder (ADHD), as well as on the fact that this syndrome affects children who have undergone either high-risk conditions during pregnancy, during delivery or at the postnatal periods, there are discrepancies in interpretation of these observations. The symptoms of ADHD undoubtedly represent the predominance of excitation over inhibition processes (delay, stimulus discrimination and differentiation, etc.), which economize and make the behavior of the organism more effective. At the level of plasma membranes of neurons, one of the factors of inhibition is considered to be the chloride channel. It and all other active protein complexes (channels, receptors, enzymes) must have a stable spatial orientation. Although the chloride channel has some intracellular fixation, it must also have fixation points in the space of the lipid bilayer. This can be offered by fatty acids with a longer chain and with more double bonds - especially docosahexaenoic acid. This acid has millions of possible spatial variations and normally represents one-fifth of all fatty acids in the mammalian brain. Lack of PUFA omega 3 fatty acids in the body (and subsequently in the CNS) can pose a significant risk to the functionality of neuronal membranes (for its fluidity and the ability to anchor proteins in the membrane). We have shown that so-called high-risk newborns, i.e. premature infants, with low birth weight, in the presence of gestational diabetes in mothers, in hypotrophy, etc., show a significant deficit of just unsaturated fatty acids of the omega 3 series. Similarly, stressful situations, e.g. nutritional deprivation also causes an acute decrease in PUFA omega 3 levels in the body (and subsequently in the CNS) can pose a significant risk to the functionality of the neuronal membrane (for its fluidity and also the ability to help anchor proteins in the membrane). Resting membrane potential depends on the activity of the transmembranous localized enzyme Na-K ATPase. Both hypoglycemia and short-term nutritional stress or the presence of arachidonic acid in the extracellular space significantly reduce the activity of that enzyme. In contrast, catecholamines have been shown to increase the enzyme activity in in vivo and in vitro experiments. Among the causes of the development of ADHD syndrome not only a certain genetic predisposition is expected, but also an "unfavorable" environment that interferes with intrauterine and postnatal development. In addition to their general effect, environmental factors can lead to the impairment of neuronal cell membranes and affect and retard CNS differentiation processes. [ABSTRACT FROM AUTHOR]

Background Phytophthora nicotianae is a fungal soil-borne pathogen that damages various plant species. Mancozeb and Zineb, fungicides containing manganese (Mn) and zinc (Zn) as the main components, are widely used to control the diseases caused by Phytophthora. However, the inhibition mechanism is still unclear. The purpose of this study was to examine the effects of Mn and Zn on P. nicotianae and to determine possible inhibitory mechanisms of Mn and Zn on sporangiogenesis of P. nicotianae. Methods The mycelial growth, sporangium generation, zoosporogenesis and zoospore germination of P. nicotianae were observed under Mn and Zn treatments. The gene (csn4 and csn7) expression levels of P. nicotianae in different growth stages were examined. Csn4 and csn7 gene expression, superoxide dismutase (SOD) activity, catalase (CAT) activity and malondialdehyde (MDA) content were tested at the stage of sporangiogenesis under different Mn and Zn concentrations. Results Mycelial growth of P. nicotianae was significantly inhibited by Mn from ≥1 mg/L concentration and by Zn from ≥10 mg/L. The sporangia production, sporangia release, and zoospore germination of P. nicotianae were significantly reduced by Mn at all concentrations, while treatment with Zn from ≥0.5 mg/L concentration significantly inhibited the same processes. At the same concentration, the inhibition rate of Mn on the growth process of P. nicotianae was higher than that of Zn. The csn4 and csn7 gene transcription of P. nicotianae were significantly reduced by all treatments with Mn and Zn at the stage of sporangiogenesis. With the increase of Mn concentration, the activities of SOD and CAT increased to maxima and then decreased, and the content of MDA gradually increased during sporangiogenesis of P. nicotianae. The sporangia production of P. nicotianae was significantly positively correlated with the expression levels of the genes csn4 and csn7. Conclusion The inhibitory effect of Mn on the growth process of P. nicotianae was stronger than that of Zn, especially on sporangiogenesis and zoosporogenesis. A possible mechanism of the inhibitory effect on sporangiogenesis of P. nicotianae was that Mn and Zn acted by inhibiting the expression levels of the genes csn4 and csn7 and by affecting antioxidant enzyme activity (further resulting in lipid peroxidation) in the sporangium of P. nicotianae.

The new coronavirus (COVID‐19) was first reported in Wuhan in China, on 31 December 2019. COVID‐19 is a new virus from the family of coronaviruses that can cause symptoms ranging from a simple cold to pneumonia. The virus is thought to bind to the angiotensin‐converting enzyme 2, as a well‐known mechanism to enter the cell. It then transfers its DNA to the host in which the virus replicates the DNA. The viral infection leads to severe lack of oxygen, lung oxidative stress because of reactive oxygen species generation, and overactivation of the immune system by activating immune mediators. The purpose of this review is to elaborate on the more precise mechanism(s) to manage the treatment of the disease. Regarding the mechanisms of the virus action, the suggested pharmacological and nutritional regimens have been described. [ABSTRACT FROM AUTHOR]

Alzheimer's disease is the most common form of neurodegenerative disease and the formation of Aβ amyloid aggregates has been widely demonstrated to be the principal cause of Alzheimer's disease. Our previous study and other studies suggested that the gallate moiety played an obligatory role in the inhibition process of naturally occurring polyphenols on Aβ amyloid fibrils formation. However, the detailed mechanisms were still unknown. Thus, in the present study, the gallic acid (GA) was specially selected and the molecular recognition mechanisms between GA molecules and Aβ 1 – 40 monomer were examined and analyzed by molecular dynamics simulation. The in silico experiments revealed that GA significantly prevented the conformational changes of Aβ 1 – 40 monomer with no β-sheet structure during the whole 100 ns. By analyzing the binding sites of GA molecules to Aβ 1 – 40 monomer, we found that both hydrophilic and hydrophobic amino acid residues were participated in the binding of GA molecules to Aβ 1 – 40 monomer. Moreover, results from the binding free energy analysis further demonstrated that the strength of polar interactions was significantly stronger than that of nonpolar interactions. We believed that our results could help to elucidate the underlying mechanisms of gallate moiety on the anti-amyloidogenic effects of polyphenols at the atomic level. • The mechanisms of gallate moiety on the anti-amyloidogenic effects of polyphenols were studied by MD simulation. • The conformation of Aβ 1-40 monomer in the presence of GA was less compact than that of Aβ 1-40 monomer alone. • The binding of GA to Aβ 1-40 monomer dramatically prevented the secondary structure transition from helix to β-sheet. • GA inhibited the long-range intra-Aβ 1-40 peptide sidechain-sidechain contacts. • The polar and nonpolar interactions were both involved in the binding of GA to Aβ 1-40 monomer. [ABSTRACT FROM AUTHOR]

Sulfate-reducing bacteria are studied for their potential in heavy metal bioremediation. However, the occurrence of elevated nitrate in contaminated environments has been shown to inhibit sulfate reduction activity. While the inhibition has been suggested to result from competition with nitrate-reducing bacteria, the possibility of direct inhibition of sulfate reducers by elevated nitrate needs to be explored. Using Desulfovibrio vulgaris as a model sulfate-reducing bacterium, it was observed that significant growth inhibition was effected by 70 mM NaNO3 but not 70 mM NaCl, indicating the presence of inhibitory mechanisms in addition to osmotic stress. While the differential expression of a small number of genes in response to nitrate suggested the potential involvement of osmotic and nitrite stress responses, the roles of these two stress responses appear minor given the lack of similarity in the overall transcriptional profiles between nitrate, nitrite, and NaCl stress responses. The presence of unique stress response pathways in nitrate stress is further suggested by the lack of extensive similarities in the response profiles between nitrate stress and various other stress conditions. In addition, the importance of genes with functions in the metabolism of S-adenosylmethionine in the shift of energy flow was implicated in nitrate stress response.

This work was aimed to investigate the α-glucosidase inhibitory potential of methanol, petroleum ether, ethyl acetate, n -butanol, and water extracts/fractions of four Dendrobium species , which are traditional medicinal plants over the centuries, and discovery some important polyphenols in terms of lowering blood sugar based our previous research. Furthermore, the enzyme kinetics, HPLC, fluorescence spectra, and molecular docking were performed to provide additional insights into the binding mechanisms between individual polyphenol and α-glucosidase. All the organic extracts/fractions showed promising results on α-glucosidase with IC 50 values of 4.23–52.53 μg/mL. The EtOAcF of D. chrysotoxum (EtOAcF-DC) possessed the lowest IC 50 value (4.23 ± 0.19 μg/mL) against α-glucosidase. And an obvious correlation existed between the total phenol contents and α-glucosidase inhition capacity. Schaftoside, isoschaftoside, 2,4,7-trihydroxy-9,10-dihydrophenanthrene (TD), dihydroresveratrol, coelonin, nudol (NU), gigantol (GT), erianin, and tristin were identified as the main polyphenol components in these four Dendrobium plants. However, only TD, NU, coelonin, and GT had significant inhibitory activity on α-glucosidase. TD, NU and GT were discovered simultaneously in the EtOAc fractions (EtOAcFs) of the four Dendrobium species and occupied higher contents than other components, thus being selected as objectives for deep research. The TD from Dendrobium species was first reported as α-glucosidase inhibitor with an IC 50 value of 52.46 ± 2.34 μg/mL, which was almost 6.5 times stronger than that of acarbose (IC 50 = 338.84 ± 18.57 μg/mL), signifying it was a potential candidate for treating diabetes. NU and GT acted as uncompetitive inhibitors against α-glucosidase, while TD and EtOAcF-DC exhibited mixed-type inhibition. The fluorescence spectra analysis demonstrated that these inhibitors could quenched the fluorescence spectrum of α-glucosidase significantly. Interestingly, the NU quenched fluorescence by an unusual static quenching method. The molecular simulation illustrated these three polyphenols interacted with α-glucosidase primarily through hydrogen bonds and van der Waals interactions, and the binding sites between polyphenols and α-glucosidase supported the obtained results of inhibition kinetics. This study revealed that the phenolic-rich extracts/fractions and polyphenol compounds from Dendrobium plants could be potential α-glucosidase inhibitors. [ABSTRACT FROM AUTHOR]

Abstract Epigallocatechin-3-O-gallate (EGCG), a tea polyphenol is renowned for its anti-diabetic properties, however limited studies elucidate its hypoglycemic mechanism from multi-perspectives. In the present study, the interaction between EGCG and α-glucosidase was investigated through kinetics analysis, fluorescence spectra, Fourier transform infrared (FT-IR) spectra and molecular docking studies. Additionally, the effect of EGCG on glucose uptake and its related signaling pathway in L6 muscle cells were also investigated. The results showed that the α-glucosidase inhibitory activity of EGCG (IC 50 = 19.5 ± 0.3 μM) was higher than that acarbose (IC 50 = 278.7 ± 1.1 μM). EGCG inhibited α-glucosidase in a reversible and non-competitive manner. EGCG quenched the fluorescence of α-glucosidase due to the complex formation between EGCG and α-glucosidase, where the hydrogen bonds played a critical role. Microenvironment and the secondary structure of α-glucosidase were highly influenced by EGCG. Molecular docking results indicated that the binding sites on α-glucosidase for EGCG were close to the active site pocket of the enzyme. EGCG was also found to enhance the glucose uptake and promote GLUT4 translocation to plasma membrane via PI3K/AKT signaling pathway in L6 skeletal muscle cells. Overall, these results revealed the possible hypoglycemic mechanism of EGCG. Highlights • Interaction between EGCG and α-glucosidase was systematically determined. • EGCG possessed non-competitive reversible inhibition against α-glucosidase. • EGCG quenched the fluorescence of α-glucosidase. • The binding site of EGCG on α-glucosidase is determined by molecular docking analysis. • EGCG enhanced the glucose uptake via PI3K/AKT/GLUT4 signaling pathway in L6 cells [ABSTRACT FROM AUTHOR]

A method for rapid quantitation of insect juvenile hormones (JH) and intermediates in the biosynthetic pathway, both in vitro and in vivo (hemolymph and whole body), has been developed using GC–MS/MS. This method is as simple as the radiochemical assay (RCA), the most commonly used method for measurement of JH biosynthesis in vitro, without need for further purification and derivatization, or radioactive precursors or ligands. It shows high sensitivity, accuracy and reproducibility. Linear responses were obtained the range of 1–800 ng/mL (approximately 4–3000 nM). Recovery efficiencies for farnesol, farnesal, methyl farnesoate and JH III were approximately 100% in vitro and over 90% in vivo , with excellent reproducibility at three different spike levels. Titer of JH III in the hemolymph was relatively low at day 0 (adult female emergence) (79.68 ± 5.03 ng/mL) but increased to a maximum of 1717 ng/mL five days later. In whole body, JH III quantity reached a maximum on day 4 (845.5 ± 87.9 ng/g) and day 5 (679.7 ± 164.6 ng/g) and declined rapidly thereafter. It is in agreement with the hemolymph titer changes and biosynthetic rate of JH in vitro . Comparison with the results of inhibition of JH biosynthesis by two known inhibitors (allatostatin (AST) mimic H17 and pitavastatin) using RCA and GC–MS/MS, showed that there was little difference between the two methods In contrast to other methods, the present method with GC–MS/MS can be used to elucidate the mechanism of inhibition by inhibitors of JH biosynthesis without any derivatization and purification. This method is applicable to screening of JH inhibitors and the study of inhibitory mechanisms with high sensitivity and accurate quantification. It may also be useful for the determination of JH titer in other Arthropods. [ABSTRACT FROM AUTHOR]

Electroactive biofilms (EABs) play a crucial role in environmental bioremediation due to their excellent extracellular electron transfer (EET) capabilities. However, Cd2+ can have toxic effects on the electrochemical performance of EABs, and the comprehensive inhibition mechanism of EABs in response to Cd2+ shock remains elusive. This study indicated that Cd2+ shock significantly reduced biomass and increased oxidative stress in EABs at the cellular level. The bacterial viability of EABs in phase III under 0.5 mM Cd2+ shock (EAB Cd 2+-III 0.5) decreased by 16.31% compared to EAB CK -III. Moreover, intracellular NADH, c -Cyts, and the abundance of electroactive species were essential indicators to evaluate EET behavior of EABs. In EAB Cd 2+-III 0.5 , these indicators decreased by 26.32%, 33.40%, and 20.65%, respectively. Structural equation modeling analysis established quantitative correlations between core components and electrochemical activity at cellular and community levels. The correlation analysis revealed that the growth and electron transfer functions of EABs were predictive indicators for their electrochemical performance, with standardized path coefficients of 0.407 and 0.358, respectively. These findings enhance our understanding of EABs' response to Cd2+ shock and provide insights for improving their performance in heavy metal wastewater. [Display omitted] • Mechanistic insight into the response of EABs to Cd2+ shock was proposed. • Viability and EET behavior of EABs were analyzed at cellular and community levels. • Correlations between core components and electrochemical activity were established. • Growth and electron transfer functions can predict electrochemical activity in EABs. • ROS and electroactive species are critical for EABs' performance under Cd2+ shock. [ABSTRACT FROM AUTHOR]

White-rot fungi (WRF) and their ligninolytic enzymes have been investigated for the removal of a broad spectrum of trace organic contaminants (TrOCs) mostly from synthetic wastewater in lab-scale experiments. Only a few studies have reported the efficiency of such systems for the removal of TrOCs from real wastewater. Wastewater derived organic and inorganic compounds can inhibit: (i) WRF growth and their enzyme production capacity; (ii) enzymatic activity of ligninolytic enzymes; and (iii) catalytic efficiency of both WRF and enzymes. It is observed that essential metals such as Cu, Mn and Co at trace concertation (up to 1 mM) can improve the growth of WRF species, whereas non-essential metal such as Pb, Cd and Hg at 1 mM concentration can inhibit WRF growth and their enzyme production. In the case of purified enzymes, most of the tested metals at 1–5 mM concentration do not significantly inhibit the activity of laccases. Organic interfering compounds such as oxalic acid and ethylenediaminetetraacetic acid (EDTA) at 1 mM concentration are potent inhibitors of WRF and their extracellular enzymes. However, inhibitory effects induced by interfering compounds are strongly influenced by the type of WRF species as well as experimental conditions ( e.g. , incubation time and TrOC type). In this review, mechanisms and factors governing the interactions of interfering compounds with WRF and their ligninolytic enzymes are reviewed and elucidated. In addition, the performance of WRF and their ligninolytic enzymes for the removal of TrOCs from synthetic and real wastewater is critically summarized. [ABSTRACT FROM AUTHOR]

Nitrite (NO-2), one of the main substrates in the anaerobic ammonium oxidation (anammox) process, has the potential to inhibit anammox bacteria. The sensitivity of anammox cells with different energy status to NO-2 was evaluated, and addition of nitrate (NO-2) inhibition on the basis of narK gene with the putative function of facilitating NO-2 / NO-2 antiporter. The results showed that the resistance of anammox bacteria to NO-2 inhibition follows the order: activecells > starved-cells > resting-cells > starved-/resting-cells. Anammmox resting cells have increasing tolerance to NO-2 in the pH range from 7.0 to 7.5. Dissipating the proton gradient by using carbonyl cyanide m-chlorophenyl hydrazine (CCCP) caused severe inhibition at all pH values including pH = 7.5. Addition of NO-2 enabled activity recovery of NO-2-inhibited anammox bacteria regardless of whether the proton gradient was disrupted or not, supporting the hypothesis of NO-2dependent detoxification via a secondary transport system. [ABSTRACT FROM AUTHOR]

As the aglycone of phloridzin, phloretin belongs to dihydrochalcone with antioxidant, anti-inflammatory and antimicrobial activities. In this study, multispectroscopic techniques and molecular docking analysis were used to investigate the inhibitory activity and mechanisms of phloretin on α-glucosidase. The results showed that phloretin reversibly inhibited α-glucosidase in a mixed-type manner and the value of IC 50 was 31.26 μg L −1 . The intrinsic fluorescence of α-glucosidase was quenched by the interactions with phloretin through a static quenching mechanism and spontaneously formed phloretin-α-glucosidase complex by the driving forces of van der Waals force and hydrogen bond. Atomic force microscope (AFM) studies and FT-IR measurements suggested that the interactions could change the micro-environments and conformation of the enzymes and the molecular docking analysis displayed the exact binding site of phloretin on α-glucosidase. These results indicated that phloretin is a strong α-glucosidase inhibitor, thus could be contribute to the improvement of diabetes mellitus. [ABSTRACT FROM AUTHOR]

• This paper applied the theoretical knowledge of visual marking to the study of industrial icons, and the relationship between the inhibitory mechanism of visual marking and the information characteristic, semantic categories and spatial layout of industrial icons is explored from the inhibition of location, feature, category and spatial structure in visual marking. As a carrier of complex information, industrial icons play an important role in intelligent manufacturing systems, and the superiority of its visual presentation affects the visual search efficiency of operators. This paper applied the theoretical knowledge of visual marking to the study of industrial icons, and the relationship between the inhibitory mechanism of visual marking and the information characteristic, semantic categories and spatial layout of industrial icons is explored from the inhibition of location, feature, category and spatial structure in visual marking. The experimental results show that: in the aspect of feature inhibition, the 2.5D style inhibits the flat style and the complex icon inhibits the simple icon. In the aspect of category inhibition, the inhibitory degree of four different categories are warning, monitoring, equipment and production in order from high to low. In the aspect of spatial layout inhibition, the regular layout inhibits the chaotic layout and the orderly arrangement inhibits the disorderly arrangement. It is concluded that there is a certain correlation among the industrial icons' inhibition of feature, category and spatial layout, and the priority of category is higher than that of feature, the spatial layout inhibition is jointly influenced by the inhibition of feature and category, among which category inhibition takes the lead role. [ABSTRACT FROM AUTHOR]

Fusarium graminearum is a pathogen that can infect wheat, corn and other grain crops, resulting in a reduction in grain yield and nutritional value and even causing serious harm to public health. Ferulic acid (FA) is popularly extracted from a variety of traditional Chinese medicines, such as ferula, asafoetida and angelica, and is a promising fungicide for the preservation of foods due to its antibacterial, antioxidant and anti-inflammatory functions. Based on its efficacy, the inhibitory activity of FA against F. graminearum was evaluated and the involved mechanism was investigated as well. The EC 50 and EC 90 values were approximately 20 μg/mL and 100 μg/mL, respectively, according to the mycelial dry weight test. TEM and SEM analyses after FA treatment revealed that the cell membrane of hyphae was impaired and showed the following characteristics: coarse surface with wrinkles, blurry ultrastructure edges, and cytoplasmic leakage. In addition, cell integrity and permeability analyses were performed to identify its antifungal mechanism. After FA treatment, the fluorescence intensity of mycelia after PI staining increased significantly (p < 0.001), and the high concentration group showed a continuous rise in extracellular relative conductivity and more significant leakage of nucleic acids and protein. Moreover, FA inhibited ergosterol synthesis in the F. graminearum cell membrane, which confirmed that the target site of FA antifungal action was the cell membrane. • FA exhibited antifungal effect on Fusarium graminearum. • FA induced the disruption of cell surface morphology and internal structure. • FA damaged the cell integrity and caused the leakage of cellular content. • The cell membrane as the targeted site for the antifungal mechanism of FA. [ABSTRACT FROM AUTHOR]

Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin in the human body. Overproduction of melanin could lead to a variety of skin disorders. Glabridin, an isoflavan, isolated from the root of Glycyrrhiza glabra Linn, has exhibited several pharmacological activities, including excellent inhibitory effects on tyrosinase. In this paper, the inhibitory kinetics of glabridin on tyrosinase and their binding mechanisms were determined using spectroscopic, zebrafish model and molecular docking techniques. The results indicate that glabridin reversibly inhibits tyrosinase in a noncompetitive manner through a multiphase kinetic process with the IC 50 of 0.43 μmol/L. It has been shown that glabridin had a strong ability to quench the intrinsic fluorescence of tyrosinase mainly through a static quenching procedure, suggesting a stable glabridin-tyrosinase complex may be generated. The results of molecular docking suggest that glabridin did not directly bind to the active site of tyrosinase. Moreover, according to the results of zebrafish model system, glabridin shows no effects on melanin synthesis in zebrafish but presents toxicity to zebrafish embryo. The possible inhibitory mechanisms, which will help to design and search for tyrosinase inhibitors especially for glabridin analogues, were proposed. [ABSTRACT FROM AUTHOR]

The widespread utilization of silver nanoparticles (AgNPs) in industrial and commercial products inevitably raises the release into wastewater that might cause potential negative impacts on sewage treatment system. In this paper, long-term exposure experiments at four levels were conducted to determine whether AgNPs caused adverse impacts on nutrient removals in sequencing batch reactors (SBRs) and changes of microbial community structure. Compared with the control reactor (without AgNPs), carbon, nitrogen and phosphorus removal in presence of 0.1 mg/L AgNPs was no difference. However, presence of 1.0 and 10 mg/L AgNPs decreased the average removal efficiencies of COD from 95.4% to 85.2% and 68.3%, ammonia nitrogen from 98.8% to 71.2% and 49%, SOP from 97.6% to 75.5% and 54.1%, respectively. It was found that AgNPs could accumulate in sludge with the distribution coefficients of 39.2–114 L/g, inhibit the protein and polysaccharide production in EPS, reduce the SOUR of sludge, and greatly increase LDH release from microbial cells. The illumina high-throughput sequencing results indicated that AgNPs concentration changed the structures of bacterial communities, associating with the effects of AgNPs on reactor performance. Sequence analyses showed that Proteobacteria , Bacteroidetes and Acidobacteria were the dominant phyla. It was notable that AgNPs addition reduced the contents of several nitrifying bacteria at genera level in sludge, leading to the lower removal of nitrogen. [ABSTRACT FROM AUTHOR]

This work aimed to investigate effects and reaction mechanisms of CaO/Fe 2 O 3 on emission behaviors of arsenic during sewage sludge pyrolysis. The results showed that 24.8–54.2%, 26.4–60.4% and 27.7–63.1% of arsenic escaped from three samples when pyrolysis process happened at 723, 923 and 1123 K respectively. And the sludge which contained higher calcium and iron contents released less arsenic than others. External CaO and Fe 2 O 3 were added into the sewage sludge to study their effects on arsenic emissions during pyrolysis, where both of them inhibited arsenic emission effectively, especially at high temperatures. With the help of thermogravimetry analysis and X-ray fluorescence, inhibitory mechanisms of CaO/Fe 2 O 3 on arsenic emission during sewage sludge pyrolysis were studied. CaO could react with As 2 O 3 , As 2 S 3 and NaAsO 2 to form nonvolatile substances, such as Ca(AsO 2 ) 2 ; while Fe 2 O 3 could react with NaAsO 2 to generate certain substances which was stable below 1123 K. [ABSTRACT FROM AUTHOR]

The three purified herbal compounds tetrahydropalmatine (Tet), neferine and berberine (Ber) were explored in vitro for basic inhibition mechanisms towards recombinant human CYP1A2, CYP2D6 and CYP3A4 metabolic activities. Phenacetin, dextromethorphan and testosterone, respectively, were used as CYP1A2, CYP2D6 and CYP3A4 substrates, and their metabolites were determined by validated HPLC methodologies. Positive inhibition controls were used. Mechanism-based (irreversible) inhibition was assessed by time-dependent and nicotinamide adenine dinucleotide phosphate-dependent and reversible inhibition by Lineweaver-Burk plot assessments. Inhibition mechanisms were also assessed by computerized interaction prediction by using the Discovery Studio CDOCKER software (Accelrys, San Diego, CA, USA). Tetrahydropalmatine showed a mechanism-based inhibition of both CYP1A2 and CYP2D6, and Ber of CYP2D6. Neferine and Ber both showed a nonmechanistic inhibition of CYP1A2. All compounds showed a similar and significant mechanism-based inhibition of CYP3A4. Tetrahydropalmatine and Ber demonstrated both reversible and irreversible inhibition of CYP2D6 and CYP3A4. Tetrahydropalmatine and Ber displayed H-bond and several Pi-bond connections with specific amino acid residues of CYP1A2, CYP2D6 and CYP3A4, giving further knowledge to the identified reversible and irreversible herb-drug interactions. Tetrahydropalmatine and Ber should be considered for herb-drug interactions in clinical therapy until relevant clinical studies are available. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Motor directional tuning (Georgopoulos et al., 1982) has been found in every brain area in which it has been sought for during the past 30-odd years. It is typically broad, with widely distributed preferred directions and a population signal that predicts accurately the direction of an upcoming reaching movement or isometric force pulse (Georgopoulos et al., 1992). What is the basis for such ubiquitous directional tuning? How does the tuning come about? What are the implications of directional tuning for understanding the brain mechanisms of movement in space? This review addresses these questions in the light of accumulated knowledge in various sub-fields of neuroscience and motor behavior. It is argued (a) that direction in space encompasses many aspects, from vision to muscles, (b) that there is a directional congruence among the central representations of these distributed directions arising from rough but orderly topographic connectivities among brain areas, (c) that broad directional tuning is the result of broad excitation limited by recurrent and non-recurrent (i.e. direct) inhibition within the preferred direction loci in brain areas, and (d) that the width of the directional tuning curve, modulated by local inhibitory mechanisms, is a parameter that determines the accuracy of the directional command.

Motor directional tuning (Georgopoulos et al., 1982) has been found in every brain area in which it has been sought for during the past 30-odd years. It is typically broad, with widely distributed preferred directions and a population signal that predicts accurately the direction of an upcoming reaching movement or isometric force pulse (Georgopoulos et al., 1992). What is the basis for such ubiquitous directional tuning? How does the tuning come about? What are the implications of directional tuning for understanding the brain mechanisms of movement in space? This review addresses these questions in the light of accumulated knowledge in various sub-fields of neuroscience and motor behavior. It is argued (a) that direction in space encompasses many aspects, from vision to muscles, (b) that there is a directional congruence among the central representations of these distributed "directions" arising from rough but orderly topographic connectivities among brain areas, (c) that broad directional tuning is the result of broad excitation limited by recurrent and non-recurrent (i.e., direct) inhibition within the preferred direction loci in brain areas, and (d) that the width of the directional tuning curve, modulated by local inhibitory mechanisms, is a parameter that determines the accuracy of the directional command. [ABSTRACT FROM AUTHOR]

Abstract: The objectives of this work were to prepare and characterize an anti-algal sustained-release granule, then study its mode of action on Microcystis aeruginosa. The anti-algal sustained-release granule was prepared with artemisinin using alginate–chitosan microcapsule technology and characterized by a high performance liquid chromatography with an evaporative light-scattering detector, Fourier transform infrared spectral analysis, and a scanning electron microscope. The optimum preparation (in %, w/v) using the orthogonal method was: 2.5 sodium alginate; 0.25 chloride; 0.6 artemisinin; 2 calcium chloride; and 1.5mL of the cross-linking agent, glutaraldehyde. These artemisinin sustained-release granules had a high encapsulation efficiency (up to 68%) and good release properties (release time of more than 40d). Artemisinin sustained-release granules released cumulatively in a solution containing M. aeruginosa, and the stress on algae increased gradually within 30d. Artemisinin sustained-release granules decreased the content of the soluble protein, Chlorophyll a in 30d, increased the superoxide dismutase activity of M. aeruginosa, but exerted no effect on the soluble sugar content. Compared to direct dosing of artemisinin, algae can be inhibited longer and more effectively by the artemisinin sustained-release granules. The results of our research can aid in the development of new anti-algal sustained-release granules and lead to further study of their application in the field. [Copyright &y& Elsevier]

We present an original model designed to study how a second language (L2) is acquired in biL1nguals at different proficiencies starting from an existing L1. The model assumes that the conceptual and lexical aspects of languages are stored separately: conceptual aspects in distinct topologically organized Feature Areas, and lexical aspects in a single Lexical Network. Lexical and semantic aspects are then Linked together during Hebbian learning phases by presenting L2 lexical items and their L1 translation equivalents. The model hypothesizes the existence of a competitive mechanism to solve conflicts and simulate language switching tasks. Results demonstrate that, at the beginning of training, an L2 lexicon must parasitize its L1 equivalent to access its conceptual meaning. At intermediate proficiency, L2 items may evoke their semantics independently of L1, but with a high risk of interference. At higher proficiency, the L2 representation becomes progressively similar to the L1 representation, according to Green s (2003) convergence hypothesis. [ABSTRACT FROM AUTHOR]

Abstract: The goals of this work were to isolate and identify an anti-algal compound from extracts of Artemisia annua and study its mode of action on Microcystis aeruginosa. The anti-algal compound was isolated from the extracts using column chromatography and activity-guided fractionation methods. Artemisinin with strong anti-algal activity was identified by gas chromatography–mass spectrometry and 1H Nuclear Magnetic Resonance. The EC50 of artemisinin on M. aeruginosa was 3.2mg L−1. Artemisinin decreased the soluble protein content and increased the superoxide dismutase activity and ascorbic acid content of M. aeruginosa, but exerted no effect on soluble sugar content. The results suggested the mode of action of artemisinin on algae may primarily be the increasing level of reactive oxygen species in algae cells. The results of our research could aid in the development of new anti-algal substances and lead to further study of mechanisms of inhibitory effect on algae. [Copyright &y& Elsevier]

One of the main causes for age-related declines in working memory is a higher vulnerability to retroactive interference due to a reduced ability to suppress irrelevant information. However, the underlying neural correlates remain to be established. Magnetoencephalography was used to investigate differential neural patterns in young and older adults performing an interference-based memory task with two experimental conditions, interrupting and distracting, during successful recognition. Behaviorally, both types of retroactive interference significantly impaired accuracy at recognition more in older adults than in young adults with the latter exhibiting greater disruptions by interrupters. Magnetoencephalography revealed the presence of differential age-related neural patterns. Specifically, time-modulated activations in temporo-occipital and superior parietal regions were higher in young adults compared with older adults for the interrupting condition. These results suggest that age-related deficits in inhibitory mechanisms that increase vulnerability to retroactive interference may be associated with neural under-recruitments in a high-interference task. [ABSTRACT FROM PUBLISHER]

Abstract: The present study uses magnetoencephalography (MEG) to examine brain magnetic patterns in young and older adults who perform an interference-based working memory (WM) task with two experimental conditions; interrupting and distracting. Behaviourally, both types of retroactive interference significantly impair WM accuracy at recognition more in older adults than in young adults with the latter exhibiting greater disruptions by interruptors. MEG results revealed the presence of differential age-related and interference-related neural patterns. Specifically, time-modulated activations in posterior-frontal regions were increased in young compared to older adults characterising each condition. Additionally, young adults exhibited greater posterior-frontal activations for the interrupting compared to the distracting condition. These results suggest that age-related deficits in inhibitory mechanisms that increase vulnerability to interference are associated with under-recruitments in posterior-frontal regions. On the other hand, the absence of differential interference-related neural recruitments reflects that both types of interference affect WM equally in the elderly. [Copyright &y& Elsevier]

Abstract: At rest, the H-reflex is lower during lengthening than shortening actions. During passive lengthening, both soleus (SOL) and medial gastrocnemius (MG) H-reflex amplitudes decrease with increasing angular velocity. This study was designed to investigate whether H-reflex amplitude is affected by angular velocity during concentric and eccentric maximal voluntary contraction (MVC). Experiments were performed on nine healthy men. At a constant angular velocity of 60°/s and 20°/s, maximal H-reflex and M-wave potentials were evoked at rest (i.e., Hmax and Mmax, respectively) and during concentric and eccentric MVC (i.e., Hsup and Msup, respectively). Regardless of the muscle, Hmax/Mmax was lower during lengthening than shortening actions and the Hsup/Msup ratio was higher than Hmax/Mmax during lengthening actions. Whereas no action type and angular velocity effects on the MG Hsup/Msup were found, the SOL Hsup/Msup was lower during eccentric than concentric MVC and this depression was increased with higher angular velocity. Our findings indicate that the depression of the H-reflex amplitude during eccentric compared to concentric MVC depends mainly on the amount of inhibition induced by lengthening action. In conclusion, H-reflex should be evoked during both passive and active dynamic trials to evaluate the plasticity of the spinal loop. [Copyright &y& Elsevier]

The article focuses on the study which investigates the plasticity of the spinal reflexes during maximal voluntary isometric, concentric, and eccentric contractions. It evaluates 18 healthy male with no history of neurological injuries or diseases. These men were divided into an eccentric strength training group and a control group for a program which consists 18 sessions of eccentric exercise for a seven-week period. The result of the study suggests that the increase in voluntary torque induced by eccentric training could be ascribed according to the contraction type, and to an increased volitional drive from the supraspinal centers.

The concept of "inhibition" is widely used in synaptic, circuit, and systems neuroscience, where it has a clear meaning because it is clearly observable. The concept is also ubiquitous in psychology. One common use is to connote an active/willed process underlying cognitive control. Many authors claim that subjects execute cognitive control over unwanted stimuli, task sets, responses, memories, and emotions by inhibiting them, and that frontal lobe damage induces distractibility, impulsivity, and perseveration because of damage to an inhibitory mechanism. However, with the exception of the motor domain, the notion of an active inhibitory process underlying cognitive control has been heavily challenged. Alternative explanations have been provided that explain cognitive control without recourse to inhibition as concept, mechanism, or theory. This article examines the role that neuroscience can play when examining whether the psychological concept of active inhibition can be meaningfully applied in cognitive control research. [ABSTRACT FROM AUTHOR]

Abstract: The present study explored the idea that the tendency to experience intrusive memories might be associated with relatively weak cognitive control in general as indexed by the general propensity to become distracted by irrelevant information. A sample of undergraduate students (N =413) filled in self-report measures of involuntary memories, distractibility, depression and repressive coping. The results showed a significant relation between involuntary memories and distractibility, independent of both trait depression and repressive coping, indicating a general vulnerability factor. As cognitive control may be sensitive to circadian variation, time of day effects in the experience of intrusions were also explored. No significant relation emerged. A proposed relationship between deficient inhibitory mechanisms of working memory and vulnerability for developing and maintaining intrusive memories after experiencing a stressful event is also discussed. [Copyright &y& Elsevier]

Abstract: On the basis of recent evidence concerning the amplification of incoming stimulation in fibromyalgia (FM) patients, it has been proposed that a generalized hypervigilance of painful and nonpainful sensations may be at the root of this disorder. So far, research into this issue has been inconclusive, possibly owing to the lack of agreement as to the operational definition of “generalized hypervigilance” and to the lack of robust objective measures characterizing the sensory style of FM patients. In this study, we recorded auditory-evoked potentials (AEPs) elicited by tones of increasing intensity (60, 70, 80, 90, and 105 dB) in 27 female FM patients and 25 healthy controls. Fibromyalgia patients presented shorter N1 and P2 latencies and a stronger intensity dependence of their AEPs. Both results suggest that FM patients may be hypervigilant to sensory stimuli, especially when very loud tones are used. The most noteworthy difference between patients and control subjects is at the highest stimulus intensity, for which far more patients maintained increased N1-P2 amplitudes in relation to the 90-dB tones. The larger AEP amplitudes to the 105-dB tones suggest that defects in an inhibitory system protecting against overstimulation may be a crucial factor in the pathophysiology of FM. Because a stronger loudness dependence of AEPs has been related to weak serotonergic transmission, it is hypothesized that for many FM patients deficient inhibition of the response to noxious and intense auditory stimuli may be due to a serotonergic deficit. Perspective: The study of auditory-evoked potentials in response to tones of increasing intensity in FM patients may help to clarify the pathophysiology of this disorder, especially regarding the role of inhibition deficits involving serotonergic dysfunction, and may be a useful tool to guide the pharmacologic treatment of FM patients. [Copyright &y& Elsevier]

The eyes of zebra finches are placed laterally, the foveae are looking into different directions. It is unlikely that the birds are able to process different images from both eyes simultaneously. A neural mechanism might therefore be necessary to guide the birds' attention to one of the two eyes and to reduce the processing of information of the other. Previous studies revealed that information from the ipsilateral eye is indeed suppressed on its way to the telencephalon by the activity of the contralateral eye. It has been suggested that two nuclei of the tecto-thalamic tract, nucleus subpraetectalis and nucleus interstitio praetecto subpraetectalis, are a central part of such a suppressive mechanism. Using electrophysiological recordings, we investigated the influence of these two nuclei and nucleus rotundus on the processing of binocular visual information by treating the nuclei with picrotoxin or electrolytic lesions. Deactivation of inhibitory neurons within SP/IPS leads to a significant increase of the ectostriatal responses to ipsilateral and bilateral stimulation, the responses to contralateral stimulation remain unaffected. Lesioning SP/IPS does not alter the responses to visual stimuli. Treatment of nucleus rotundus with picrotoxin increases contralaterally and bilaterally, but not ipsilaterally evoked responses. A wiring diagram is presented which interprets these findings. [ABSTRACT FROM AUTHOR]

The use of tobacco products significantly contributes to the progression of periodontal disease and poor response to healing following periodontal therapy. The purpose of this study was to determine the effects of nicotine, a major component of cigarette smoking, on human periodontal ligament fibroblast (PDLF) growth, proliferation, and protein synthesis to elucidate its role in periodontal destruction associated with its use. Human PDLFs were derived from three healthy individuais undergoing extraction for orthodontic reasons. Ar a concentration higher than 2.5 mM, nicotine was found to be cytotoxic to human PDLFs (P > 0.05). Nicotine also significantly inhibited cell proliferation and decreased protein synthesis in a dose-dependent manner. At concentrations of 50 and 200 µM, nicotine suppressed the growth of PDLFs by 48% and 86% (P > 0.05), respectively. A 10-mM concentration level of nicotine significantly inhibited the protein synthesis to only 44% of these in the untreated control (P > 0.05). Furthermore, the effects of antioxidants (superoxide dismutase (SOD); catalase and 2-oxothi-azolidine-4-carboxylic acid (OTZ) and buthionine sulfoximine (BSO) were added to search for the possible mechanism of action, as well as a method for the prevention, of cigarette smoking-associated periodontal diseases. The addition of OTZ, a precursor of cysteine that metabolically promotes GSH synthesis, acted as a protective effect on the nicotine-induced cytotoxicity. However, SOD and catalase did not decrease the nicotine-induced cytotoxicity. In contrast, the addition of BSO, a cellular GSH synthesis inhibitor, enhanced the nicotine-induced cytotoxicity. These results indicate that thiol depletion coutd be the mechanism for nicotine cytotoxicity. The levels of nicotine tested inhibited cell growth, proliferation, and protein synthesis on human PDLFs. This suggests that nicotine itself might augment the destruction of periodontium associated with cigarette... [ABSTRACT FROM AUTHOR]