ARTICLE | doi:10.20944/preprints202105.0181.v1
Subject: Behavioral Sciences, Applied Psychology Keywords: physical activity; sleep; inhibitory performance; mediating effects
Online: 10 May 2021 (11:51:54 CEST)
The current study aimed to investigate the relationship between physical activity (PA) level and inhibitory control performance and then determine whether this association was mediated by multiple sleep parameters (i.e., subjective sleep quality, sleep duration, sleep efficiency, sleep disturbance). Methods. 180 healthy university students (age: 20.15 ± 1.92 years) from the East China Normal University were recruited in the present study. PA level, sleep parameters, and inhibitory control performance were assessed using the International Physical Activity Questionnaire (IPAQ), the Pittsburgh Sleep Quality Index Scale (PSQI), and a Stroop test, respectively. Data were analyzed using structual equation modeling. Results. A higher level of PA was linked to better cognitive performance. Furthermore, higher subjective sleep quality and sleep efficiency were associated with better inhibitory control performance. The mediation analysis revealed that subjective sleep quality and sleep efficiency mediated the relationship between PA level and inhibitory control performance. Conclusion. Our results are in accordance with the literature and buttress the idea that a healthy lifestyle that involves a relatively high level of regular PA and adequate sleep patterns is beneficial for cognition (e.g., inhibitory control performance). Furthermore, our study adds to the literature that sleep quality and sleep efficiency mediates the relationship of PA and inhibitory control performance expanding our knowledge in the field of exercise-cognition.
ARTICLE | doi:10.20944/preprints202105.0473.v1
Subject: Behavioral Sciences, Behavioral Neuroscience Keywords: inhibitory control; executive function; event-related potentials; electroencephalography; N200; P300; cognitive aging; neural recruitment
Online: 20 May 2021 (10:18:16 CEST)
Aging is accompanied by frontal lobe and non-dominant hemisphere recruitment that supports executive functioning, such as inhibitory control, which is crucial to all cognitive functions. Yet, the spatio-temporal sequence of processing underlying successful inhibition and how it changes with age is understudied. Thus, we assessed N200 (conflict monitoring) and P300 (response inhibition, performance evaluation) event-related potentials (ERPs) in young and healthy older adults during comparably performed successful stop-signal inhibition. We additionally interrogated the continuous spatio-temporal dynamics of N200- and P300-related activation within each group. Young adults had left hemisphere dominant N200, while older adults had overall larger amplitudes and right hemisphere dominance. N200 activation was biphasic in both groups but differed in scalp topography. P300 also differed, with larger right amplitudes in young, but bilateral amplitudes in old, with old larger than young in the left hemisphere. P300 was characterized by an early parieto-occipital peak in both groups, followed by a parietal slow wave only in older adults. A temporally similar but topographically different final wave followed in both groups that showed anterior recruitment in older adults. These findings illuminate differential age-related spatio-temporal recruitment patterns for conflict monitoring and response inhibition that are critically important for understanding age-related compensatory activation.
ARTICLE | doi:10.20944/preprints201912.0398.v1
Subject: Chemistry, Organic Chemistry Keywords: Cladosporium sp.; altertoxins; quorum sensing inhibitory activity
Online: 31 December 2019 (02:31:16 CET)
Five new perylenequinone derivatives, altertoxins VIII-XII (1-5), as well as one known compound cladosporol I (6), were isolated from the fermentation broth of Cladosporium sp. KFD33 from a blood cockle from Haikou Bay, China. Their structures were determined based on spectroscopic methods and ECD spectra analysis along with quantum ECD calculations. Compounds 1-6 exhibited quorum sensing inhibitory activities against Chromobacterium violaceum CV026 with MIC values of 30, 30, 20, 30, 20 and 30 μg/well, respectively.
ARTICLE | doi:10.20944/preprints202208.0171.v2
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: combination; antimicrobial resistance; selection index; collateral sensitivity; mutant prevention concentration; minimal inhibitory concentration; fractional inhibitory concentration index; stress factor
Online: 13 September 2022 (07:53:32 CEST)
Antimicrobial resistance (AMR) has been a serious threat to human health, and combination therapy is proved to be an economic and effective strategy to fight the resistance. However, the abuse of drug combinations would conversely accelerate the spread of AMR. In our previous work, it had been concluded that the mutant selection indexes (SIs) of one agent against a specific bacterial strain are closely related to the proportions of two agents in a drug combination. To discover probable correlations, predictors and laws for further proposing feasible principles and schemes guiding the AMR-preventing practice, here three aspects were further explored. First, the power function (y=axb, a > 0) correlation between the SI (y) of one agent and the ratio value (x) of two agents in a drug combination was further established based on the mathematical and statistical analyses for those experimental data, and two rules a1 × MIC1 = a2 × MIC2 and b1 + b2 = -1 were discovered from both equations of y=a1xb1 and y=a2xb2 respectively for two agents in drug combinations. Simultaneously, it was found that one agent with larger MPC alone for drug combinations show greater potency for narrowing itself MSW and preventing the resistance. Second, a new concept as mutation-preventing selection index (MPSI) was proposed and used for evaluating the mutation-preventing potency difference of two agents in drug combinations, and the positive correlation between the MPSI and the mutant prevention concentration (MPC) or minimal inhibitory concentration (MIC) was subsequently established. Inspired by this, the significantly positive correlation, contrary to previous reports, between the MIC and the corresponding MPC of antimicrobial agents against pathogenic bacteria was established using one hundred and eighty-one of data pairs reported. These results together of above three aspects indicate that the MPCs in alone and combination are very important indexes for drug combinations to predict the mutation-preventing effects and the trajectories of collateral sensitivity, and while the MPC of an agent can be roughly calculated from its corresponding MIC. Subsequently, the former conclusion was further verified and improved by the antibiotic exposure to forty-three groups designed as different drug concentrations and various proportions. The results further proposed that the C/MPC for the agent with larger proportion in drug combinations can be considered as a predictor and is the key to judge whether the resistance and the collateral sensitivity occur to two agents. Based on these above correlations, laws, and their verification experiments, some principles were proposed, and a diagram of the mutation-preventing effects and the resistant trajectories for drug combinations with different concentrations and ratios of two agents was presented. Simultaneously, the reciprocal of MPC alone (1/MPC), proposed as the stress factors of two agents in drug combinations, together with their SI in combination, is the key to predict the mutation-preventing potency and control the trajectories of collateral sensitivity. Finally, a preliminary scheme for antimicrobial combinations preventing the AMR was further proposed for subsequent improvement research and clinic popularization, based on the above analyses and discussion. Moreover, some similar conclusions were speculated for triple or multiple drug combinations.
COMMUNICATION | doi:10.20944/preprints201810.0408.v1
Subject: Chemistry, Other Keywords: Salvia pachyphylla; plant extracts; antioxidant; antimicrobial; antiproliferative; enzyme inhibitory
Online: 18 October 2018 (09:56:26 CEST)
The antioxidant, antimicrobial, antiproliferative, and enzyme inhibitory properties of five extracts from aerial parts of Salvia pachyphylla were examined to assess the prospective of this plant as a source of natural products with therapeutic potential. Those properties were analyzed performing a set of standard assays. The extract obtained with dichloromethane showed the most variety of components, as yielded promising results in all completed assays. Furthermore, the extract obtained with ethyl acetate exhibited that greatest antioxidant activity as well as the best xanthine oxidase inhibitory activity. Remarkably, both extracts obtained with n-hexane or dichloromethane revealed significant antimicrobial activity against the Gram-positive bacteria; also, they showed greater antiproliferative activity against three representative cell lines of the most common types of cancers in women worldwide, and against a cell line that exemplifies cancers that typically develop drug resistance. Despite that other extracts were less active, such as the methanolic or aqueous, their results are promising for the isolation and identification of novel bioactive molecules.
ARTICLE | doi:10.20944/preprints202210.0439.v1
Subject: Behavioral Sciences, Behavioral Neuroscience Keywords: executive function; early childhood; fNIRS; working memory; cognitive shifting; inhibitory control
Online: 28 October 2022 (07:02:39 CEST)
This study examined the relationship among the three domains of executive function (EF; cognitive shifting, inhibitory control, and working memory) to test the applicability of the unity-diversity model in preschoolers using both behavioral and fNIRS approaches. Altogether 58 Chinese preschoolers (34 boys, 24 girls, Mage = 5.86 years, SD = 0.53, Age range = 4.83-6.67 years) were administered the Dimensional Card Change Sort (DCCS), go/no-go, and missing scan task. Their brain activations in the prefrontal cortex during the tasks were examined using fNIRS. First, the behavioral results indicated that the missing scan task scores (working memory) correlated with the DCCS (cognitive shifting) and go/no-go tasks (inhibitory control). But the latter two did not correlate with each other. Second, the fNIRS results demonstrated that the prefrontal activations during the working memory task correlated with those in the same regions during the cognitive shifting and inhibitory control tasks. Still, the latter two did not correlate. The behavioral and neuroimaging evidence jointly indicates that the unity-diversity model of EF does apply to Chinese preschoolers.
ARTICLE | doi:10.20944/preprints202205.0149.v1
Subject: Biology, Other Keywords: organotin(IV) dithiocarbamate; childhood leukemia; antileukemia activity; anticancer potential; inhibitory effects
Online: 11 May 2022 (08:27:20 CEST)
Acute lymphoblastic leukemia (ALL) is the most common type of leukemia affecting children under the age of 15 years old in Malaysia. Chemotherapy is the primary treatment for cancer, which involves the intake of chemotherapeutic drugs to kill cancer cells. Glucocorticoids such as dexamethasone are chemotherapeutic agents used in the treatment of ALL. Although dexamethasone is highly effective, it is also associated with adverse effects such as bone fractures and organ toxicity. Therefore, there is a need to develop a new anticancer drug which milder side effects and better efficacy. Organometallic compounds such as organotin have a high potential to be developed as an antineoplastic agent and show high specificity towards cancer cells compared to normal cells. This study is done to evaluate the cytotoxic effects of diphenyltin(IV) diisopropyl dithiocarbamate (DPDT) against leukemic cells CCL-119 using the Trypan Blue exclusion (TBE) method at the intervals of 24, 48 and 72 h. Dexamethasone was used as a positive control. The cell’s morphological changes were observed at 12, 24 and 48 h using the IC50 values obtained using TBE assay. Results show that DPDT has a lower IC50 value than dexamethasone against CCL-119 cells at 24 h with a value of 4.16 ± 0.44µM and a selectivity index of 2.02. Dexamethasone exhibited cytotoxic effects against CCL-119 but only IC25 and IC10 values were obtained. Cytotoxicity testing has shown that DPDT is toxic on CCL-119 cells with IC50 values of less than 10µM. Morphological changes in cells show characteristics of apoptosis such as cell shrinkage, blebbing and formation of apoptotic bodies. In conclusion, DPDT has the potential to be made into an antineoplastic agent but requires a more detailed study involving the molecular pathway of DPDT leading to cell death.
COMMUNICATION | doi:10.20944/preprints201911.0354.v1
Subject: Biology, Plant Sciences Keywords: Acer saccharum; sugar maple; phenolics; chebulate derivatives; antioxidant; α-glucosidase inhibitory
Online: 28 November 2019 (05:30:31 CET)
To elucidate the chemical compositions of the sugar fall maple leaves, the methanol extracts were firstly fractionated by ethyl acetate and n-butanol respectively. The phenolic acids-rich fractions (ethyl acetate extracts) were further purified by various chromatographic columns including XAD macroporous resin, Sephadex LH-20, ODS and semi-preparative HPLC to yield the compounds. The isolated compounds were characterized by 1H-Nuclear Magnetic Resonance (1H-NMR), 13C-NMR, and high resolution electrospray ionisation mass spectral (HR-ESI-MS) spectroscopy. Twenty eight phenolics including fourteen flavonoids (1-14), five quinic acid derivatives (15-19), five galloyl tannins (20-24) and four other phenolic acids (25-28) were isolated and their structures were identified. The isolated compounds were evaluated for their antioxidant and α-glucosidase inhibitory activities. All of the phenolics constituents showed DPPH scavenging antioxidant activities. While, glycosides of quercetin and myricetin, galloyl tannins were showed promising α-glucosidase inhibitory activity. All of the compounds except 4, 11, 12 and 28 were isolated from sugar maple for the first time. Moreover, Compounds 9, 10, 14, 20, 21, 23, 25 and 26 were isolated from the Acer species for the first time.
ARTICLE | doi:10.20944/preprints201911.0177.v1
Subject: Life Sciences, Molecular Biology Keywords: macrophage migration inhibitory factor; HNSCC cell lines; proliferation; cell cycle; apoptosis
Online: 15 November 2019 (08:48:50 CET)
Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine that contributes to the progression of several cancers. MIF overexpression has been reported in head and neck squamous cell carcinoma (HNSCC) patients. However, the exact role of MIF in HNSCC is not fully understood. Our aim was to evaluate the amount of secreted MIF and the role of MIF in the proliferation, cell cycle, and apoptosis in HNSCC cell lines. The MIF levels in conditioned media from human primary (HN18 and HN30) and metastatic (HN17 and HN31) HNSCC cell lines were evaluated using ELISA. The HNSCC cell lines were treated with recombinant MIF and its effect on proliferation, cell cycle, and apoptotic status was determined by MTT and flow cytometry, respectively. The HNSCC-secreted MIF concentration ranged from 49.33‒860 pg/ml. Exogenous MIF (25 ng/ml) significantly increased HN18, HN30, and HN31 cell proliferation. Moreover, MIF induced cell cycle progression and inhibited apoptosis in these cells. However, MIF did not affect growth or apoptosis in HN17 cell. In conclusion, the HNSCC cell lines were evaluated secrete MIF. Exogenous MIF promotes various effects on proliferation, cell cycle, and apoptosis in HNSCC cells.
REVIEW | doi:10.20944/preprints202008.0728.v1
Subject: Biology, Physiology Keywords: T cell exhaustion; chronic viral infections; cancer; immunotherapy; epigenetics; PD-1; inhibitory receptors
Online: 31 August 2020 (17:49:37 CEST)
T cells follow a triphasic distinct pathway of activation, proliferation and differentiation before becoming functionally and phenotypically ‘exhausted’ in settings of chronic infection, autoimmunity and in cancer. Exhausted T cells progressively lose canonical effector functions, exhibit altered transcriptional networks and epigenetic signatures and gain constitutive expression of a broad coinhibitory receptor suite. This review outlines recent advances in our understanding of exhausted T cell biology and examines cellular and molecular mechanisms by which a state of dysfunction or exhaustion is established, and mechanisms by which exhausted T cells may still contribute to pathogen or tumour control. Further, this review describes our understanding of exhausted T cell heterogeneity and outlines the mechanisms by which checkpoint blockade differentially engages exhausted T cell subsets to overcome exhaustion and recover T cell function.
ARTICLE | doi:10.20944/preprints201811.0463.v1
Subject: Life Sciences, Other Keywords: Mass Spectroscopy, Bioinformatics, FGF14, Voltage Gated Channels, Schizophrenia, Alzheimer’s Disease, Sex-Specific Differences, Synaptic Plasticity, Cognitive Impairment, Excitatory/Inhibitory Tone
Online: 19 November 2018 (11:54:50 CET)
Fibroblast growth factor 14 (FGF14) is a member of the intracellular FGFs, a group of proteins with roles in neuronal ion channel regulation and synaptic transmission. We have previously demonstrated that a male Fgf14-/- mouse model recapitulates salient endophenotypes of synaptic dysfunction and behaviors associated with schizophrenia (SZ). As the underlying etiology of SZ and its sex-specific onset remain elusive, the Fgf14-/- model provides a valuable tool to interrogate pathways that might be related to the disease mechanism. Here, we performed label free quantitative proteomics and bioinformatics to identify enriched pathways at the proteome level in the male and female hippocampi from Fgf14+/+ and Fgf14-/- mice. We discovered that many differentially expressed proteins in Fgf14-/- animals are associated with SZ. In addition, measured changes in the proteome and signaling pathways were predominantly sex-specific with the male Fgf14-/- being distinctly enriched for pathways associated with neuropsychiatric disorders and addiction and the female exhibiting modest changes. In the male Fgf14-/- mouse the major protein changes that could in part explain the previously described neurotransmission and behavioral phenotype of this model were loss of ALDH1A1 and PRKAR2B. ALDH1A1 has been shown to mediate an alternative pathway for GABA synthesis, while PRKAR2B is essential for dopamine 2 receptor signaling, which is the basis of current antipsychotics. Collectively, our results provide new insights in the role of FGF14 and support the use of the Fgf14-/- mouse as a useful preclinical model of SZ for generating hypothesis on the disease mechanism, sex-specific manifestation and therapy.
ARTICLE | doi:10.20944/preprints202202.0194.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: antifungal resistance; isavuconazole; cystic fibrosis; pulmonary disease; Aspergillus fumigatus; pulmonary aspergillosis; respiratory disease; antifungal stewardship; therapeutic drug monitoring; minimum inhibitory concentration (MIC)
Online: 16 February 2022 (05:12:39 CET)
Background: The burden of resistant fungal infection is rising in patients with pulmonary disease. Options for antifungal therapy are limited, and the only orally-available antifungals, the triazoles, demonstrate inter and intra-patient variability, non-linear kinetics, toxicity, drug interactions and increasing antifungal resistance. Therapeutic drug monitoring (TDM) of itraconazole, voriconazole and posaconazole has been necessary to ensure their safety and efficacy, but is considered unnecessary for the newest triazole isavuconazole, use of which is increasing. Aims: To characterise isavuconazole susceptibility of Aspergillus fumigatus isolates in a tertiary respiratory referral centre to understand prevalence of isavuconazole antimicrobial resistance. To retrospectively review experience of isavuconazole use in this setting, assessing tolerability and therapeutic drug monitoring. Methods: A retrospective observational analysis of adult patients with respiratory disease in a tertiary hospital setting between Sept 2016 and Aug 2021. Clinical cultures were collected and triazole Minimum inhibitory concentration (MIC) were recorded (based on Clinical & Laboratory Standards Institute (CLSI method)). Isavuconazole trough drug levels were carried out as part of the standard of care. Clinical outcomes of treatment were evaluated, along with drug tolerance and TDM. Results: During the study period, isavuconazole susceptibility testing was performed on 26 Aspergillus spp isolates. 80.8% of Aspergillus fumigatus isolates were non-wild type and had isavuconazole MIC > 1mg/L, and 73.0% had MIC above the EUCAST (European Committee on Antimicrobial Susceptibility Testing) epidemiological cut-off (ECOFF) of 2mg/L. There was good correlation between isavuconazole MIC and voriconazole MIC (r =0.7, p=0.0002). 54 patients had isavuconazole therapy over the study period with a median duration of 7.7 months (IQR 0.79 - 16.42). 67% of patients were able to tolerate isavuconazole, despite toxicity with prior azole treatment being the primary indication for use (in 61.8%). Increased age (r=0.29; p=0.03 (95%CI 0.02,0.52)) and gender (r for female sex=-0.31; p=0.027 (95%CI -0.52,0.036) were associated risk factors for development of adverse events (AEs). 127 Isavuconazole TDM levels were performed over the study period with 90% >1mg/L and 72% >2mg/L. Dose change from manufacturer’s dose recommendation, however, was required in 15% of patients to achieve a serum drug concentration above the EUCAST ECOFF or Area of technical uncertainty (ATU) value of 2mg/L. Conclusion: In our study, we show use of Isavuconazole as salvage therapy in chronic pulmonary fungal disease setting with high prevalence of azole resistance. Isavuconazole MICs demonstrated good correlation with voriconazole MICs suggesting the latter could be a useful surrogate marker for isavuconazole susceptibility. Although Isavuconazole achieved excellent serum drug concentrations at standard dose compared to other azole drugs, we highlight the importance of antifungal stewardship and TDM monitoring to optimise therapy in this setting.
ARTICLE | doi:10.20944/preprints202206.0234.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: corticotropin releasing factor (CRF); patch-clamp electrophysiology; sex difference; alcohol use disorder (AUD); Gamma-Aminobutyric Acid (GABA); central amygdala (CeA); spontaneous inhibitory post synaptic currents (sIPSCs)
Online: 16 June 2022 (08:41:35 CEST)
Alcohol use disorder (AUD) is a chronically relapsing disease characterized by loss of control in seeking and consuming alcohol (ethanol) driven by recruitment of brain stress systems. However, AUD differs among the sexes: men are more likely to develop AUD, but women progress from casual to binge drinking and heavy alcohol use more quickly. The central amygdala (CeA) is a hub of stress and anxiety, with corticotropin releasing factor (CRF)-CRF1 receptor and GABAergic signaling dysregulation occurring in alcohol dependent male rodents. However, we recently showed that GABAergic synapses in female rats are less sensitive to the acute effects of ethanol. Here, we used patch clamp electrophysiology to examine the effects of alcohol dependence on the CRF-modulation of rat CeA GABAergic transmission of both sexes. We found that GABAergic synapses of naïve female rats were unresponsive to CRF application compared males, although alcohol dependence induced a similar CRF responsivity in both sexes. In situ hybridization revealed that females had less CeA neurons containing mRNA for the CRF1 receptor (Crhr1) than males, but in dependence, the percentage of Crhr1-expressing neurons in females increased, unlike males. Overall, our data provide evidence for sexually dimorphic CeA CRF system effects on GABAergic synapses in dependence.
ARTICLE | doi:10.20944/preprints202208.0324.v1
Subject: Life Sciences, Immunology Keywords: T cytotoxic cells; Leukocyte-associated Immunoglobulin-like Receptor-1; LAIR-1; Hepatitis C virus genotype 4; HCV G4; hepatocellular carcinoma; cirrhosis; immune inhibitory checkpoints; inflammation; prognosis; insulin resistance
Online: 17 August 2022 (11:38:10 CEST)
Background and Aim. Since virus-related hepatocellular carcinoma (HCC) pathogenesis involves liver inflammation, therefore, post-hepatitis C virus (HCV) infection would be a cause for liver cirrhosis that would progress to HCC. Cytotoxic T cells (Tc) are known to be involved in post-HCV complications and HCC pathogenesis. The inhibitory checkpoint Leukocyte-Associated Immunoglobulin-like Receptor-1 (LAIR-1) is expressed on Tc. Therefore, we aimed to determine whether the Tc expression level of LAIR-1 is associated with HCC progression post-HCV and moreover, to evaluate LAIR-1 expression as a non-invasive biomarker for HCC progression in the context of liver cirrhosis post-HCV genotype 4 (G4) in Egyptian patients’ peripheral venous blood liquid biopsy. We studied LAIR-1 expression on Tc related to the progression of liver cirrhosis in a case-controlled study enrolled 64 patients with post-HCV G4-HCC and 37 patients with post-HCV G4-liver cirrhosis. Methods: LAIR-1 expression was analyzed by flow cytometry. Results: LAIR-1 expression on Tc and the percentage of Tc positive for LAIR-1 (LAIR-1+Tc %) were significantly higher in the post-HCV G4-HCC group compared to the post-HCV G4-liver cirrhosis