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OBJECTIVE: Feedback facilitates learning by guiding and modifying behaviors through an action-outcome contingency. As the majority of existing studies have focused on the immediate presentation of feedback, the impact of delayed feedback on learning is understudied. Prior work demonstrated that learning from immediate and delayed feedback employed distinct brain regions in healthy individuals, and compared to healthy individuals, individuals with traumatic brain injury (TBI) are impaired in learning from immediate feedback. The goal of the current investigation was to assess the effects of delayed vs immediate feedback on learning in individuals with TBI and examine brain networks associated with delayed and immediate feedback processing. SETTING: Nonprofit research organization. PARTICIPANTS: Twenty-eight individuals with moderate-to-severe TBI. DESIGN: Participants completed a paired-associate word learning task while undergoing magnetic resonance imaging. During the task, feedback was presented either immediately, after a delay, or not at all (control condition). MAIN MEASURES: Learning performance accuracy, confidence ratings, post-task questionnaire, and blood oxygen level-dependent signal. RESULTS: Behavioral data showed that delayed feedback resulted in better learning performance than immediate feedback and no feedback. In addition, participants reported higher confidence in their performance during delayed feedback trials. During delayed vs immediate feedback processing, greater activation was observed in the superior parietal and angular gyrus. Activation in these areas has been previously associated with successful retrieval and greater memory confidence. CONCLUSION: The observed results might be explained by delayed feedback processing circumventing the striatal dopaminergic regions responsible for learning from immediate feedback that are impaired in TBI. In addition, delayed feedback evokes less of an affective reaction than immediate feedback, which likely benefited memory performance. Indeed, compared to delayed feedback, positive or negative immediate feedback was more likely to be rated as rewarding or punishing, respectively. The findings have significant implications for TBI rehabilitation and suggest that delaying feedback during rehabilitation might recruit brain regions that lead to better functional outcomes.
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BACKGROUND: This paper describes the protocol for a Phase I/II, parallel-group, single-blind randomized controlled trial (RCT). The RCT investigates the combined effects of 12-weeks of aerobic exercise training (AET) integrated with virtual reality (VR) and cognitive rehabilitation (CR) on new learning and memory in 78 persons with multiple sclerosis (MS) who have mobility disability and objective impairments in learning and memory. METHODS: Participants will undergo baseline assessments consisting of neuropsychological testing, neuroimaging, self-report questionnaires, and cardiorespiratory fitness. Participants will then be randomized into one of two conditions using concealed allocation: aerobic cycling exercise that incorporates VR combined with CR or stretching and toning (i.e., active control; S/T) combined with CR. Participants will be masked regarding the intent of the conditions. After 7-weeks of exercise alone, the 5-week Kessler Foundation modified Story Memory Technique (KF-mSMT®) will be integrated into the training. After the 12-week training period, participants will complete the same measures as at baseline administered by treatment-blinded assessors. Primary study outcomes include new learning and memory (NLM) measured by a small battery of neuropsychological assessments that assess list learning (California Verbal Learning Test-II), prose memory (Memory Assessment Scale), visuospatial memory (Brief Visuospatial Memory Test-Revised), and everyday memory (Ecological Memory Simulations). Secondary study outcomes include neuroimaging outcomes of hippocampal structure, function, and connectivity. CONCLUSION: If successful, this trial will provide the first Class I evidence supporting the unique combination of aerobic cycling exercise with VR and CR for treating MS-related learning and memory impairments in persons with mobility disability.
Subject(s)
Multiple Sclerosis , Adult , Female , Humans , Male , Middle Aged , Cardiorespiratory Fitness/physiology , Cognitive Training , Exercise/physiology , Exercise Therapy/methods , Learning , Memory , Mobility Limitation , Multiple Sclerosis/rehabilitation , Multiple Sclerosis/psychology , Multiple Sclerosis/complications , Neuropsychological Tests , Single-Blind Method , Virtual Reality Exposure Therapy/methods , Randomized Controlled Trials as Topic , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as TopicABSTRACT
Some of the most metabolically diverse species of bacteria (e.g., Actinobacteria) have higher GC content in their DNA, differ substantially in codon usage, and have distinct protein folding environments compared to tractable expression hosts like Escherichia coli. Consequentially, expressing biosynthetic gene clusters (BGCs) from these bacteria in E. coli often results in a myriad of unpredictable issues with regard to protein expression and folding, delaying the biochemical characterization of new natural products. Current strategies to achieve soluble, active expression of these enzymes in tractable hosts can be a lengthy trial-and-error process. Cell-free expression (CFE) has emerged as a valuable expression platform as a testbed for rapid prototyping expression parameters. Here, we use a type III polyketide synthase from Streptomyces griseus, RppA, which catalyzes the formation of the red pigment flaviolin, as a reporter to investigate BGC refactoring techniques. We applied a library of constructs with different combinations of promoters and rppA coding sequences to investigate the synergies between promoter and codon usage. Subsequently, we assess the utility of cell-free systems for prototyping these refactoring tactics prior to their implementation in cells. Overall, codon harmonization improves natural product synthesis more than traditional codon optimization across cell-free and cellular environments. More importantly, the choice of coding sequences and promoters impact protein expression synergistically, which should be considered for future efforts to use CFE for high-yield protein expression. The promoter strategy when applied to RppA was not completely correlated with that observed with GFP, indicating that different promoter strategies should be applied for different proteins. In vivo experiments suggest that there is correlation, but not complete alignment between expressing in cell free and in vivo. Refactoring promoters and/or coding sequences via CFE can be a valuable strategy to rapidly screen for catalytically functional production of enzymes from BCGs, which advances CFE as a tool for natural product research.
Subject(s)
Cell-Free System , Promoter Regions, Genetic , Streptomyces griseus/enzymology , Streptomyces griseus/genetics , Streptomyces griseus/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Multigene Family , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Polyketide Synthases/genetics , Polyketide Synthases/metabolism , Codon/genetics , AcyltransferasesABSTRACT
It is widely recognised that orange peels contain a considerable quantity of phenolics, primarily in the form of glycosides. The process of fermentation holds potential as a viable method for extracting phenolic compounds and facilitating their biotransformation into novel metabolites. The aim of this study was to assess the enhanced release of phenolic compounds through the process of solid-state fermentation of orange peels using microorganisms. Following a 6-day incubation period, the methanol extract obtained from the sample fermented with starter Banh men exhibited the highest concentration of total phenolic compounds (17.57 ± 0.34 mg GAE/g DW) and demonstrated the most significant DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (55.03%). The Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis revealed that the predominant phenolic compounds in all fermented samples were flavonoid aglycones, specifically naringenin, hesperetin, and nobiletin. Conversely, in the unfermented orange peels, the major compound observed was the glycoside derivative hesperidin.
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ADHD is a common chronic neurodevelopmental disorder and is characterized by persistent inattention, hyperactivity, impulsivity and are often accompanied by learning and memory impairment. Great evidence has shown that learning and memory impairment of ADHD plays an important role in its executive function deficits, which seriously affects the development of academic, cognitive and daily social skills and will cause a serious burden on families and society. With the increasing attention paid to learning and memory impairment in ADHD, relevant research is gradually increasing. In this article, we will present the current research results of learning and memory impairment in ADHD from the following aspects. Firstly, the animal models of ADHD, which display the core symptoms of ADHD as well as with learning and memory impairment. Secondly, the molecular mechanism of has explored, including some neurotransmitters, receptors, RNAs, etc. Thirdly, the susceptibility gene of ADHD related to the learning and impairment in order to have a more comprehensive understanding of the pathogenesis. Key words: Learning and memory, ADHD, Review.
Subject(s)
Attention Deficit Disorder with Hyperactivity , Memory Disorders , Attention Deficit Disorder with Hyperactivity/psychology , Attention Deficit Disorder with Hyperactivity/genetics , Humans , Animals , Memory Disorders/psychology , Memory Disorders/etiology , Learning , Disease Models, Animal , Learning Disabilities/psychology , Learning Disabilities/etiology , MemoryABSTRACT
Drug resistance and off-target toxicity are two of the greatest challenges to chemotherapeutic melanoma treatments. Nitric oxide (NO) represents an attractive alternative to conventional therapeutics due to its numerous anticancer properties and low probability of engendering resistance. As NO is highly reactive, macromolecular NO donors are needed for the controlled and targeted delivery of NO for therapeutic applications. Herein, mesoporous silica nanoparticles (MSNs) coated with hyaluronic acid (HA) were developed as a NO delivery system to facilitate controlled delivery to cancer cells through both passive and active targeting via the enhanced permeation and retention effect and directed binding of HA with CD44 receptors, respectively. The aminosilane modification, HA concentration, and HA molecular weight were systematically evaluated to facilitate the MSN coating and NO loading. The hydrodynamic diameter and dispersity of the nanoparticles increased after HA coating due to the hydrophilic nature of HA, with greater increases observed at higher HA molecular weight. Lower starting concentrations of HA and aminosilanes with longer alkyl chains favored more efficient HA coating. Faster NO-release kinetics and lower NO payloads were observed for the HA-coated MSNs relative to uncoated MSNs. However, the localized delivery of NO to cancer cells through the active targeting conferred by HA increased levels of oxidative stress and induced mitochondria-mediated apoptosis in melanoma cells. Cytotoxicity was also evaluated against human dermal fibroblasts, with the use of 6 kDa HA-coated MSNs resulting in the greatest therapeutic indices. Enhanced internalization of HA-coated nanoparticles into melanoma cells versus uncoated nanoparticles was visualized with confocal microscopy and quantified by fluorescence spectroscopy. In total, HA-coated MSNs represent a promising NO delivery system for potential use as a chemotherapeutic for skin melanomas.
Subject(s)
Hyaluronic Acid , Materials Testing , Nanoparticles , Nitric Oxide , Particle Size , Silicon Dioxide , Hyaluronic Acid/chemistry , Humans , Silicon Dioxide/chemistry , Nanoparticles/chemistry , Nitric Oxide/chemistry , Nitric Oxide/metabolism , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Cell Survival/drug effects , Drug Screening Assays, Antitumor , Drug Delivery Systems , Cell Line, Tumor , Cell Proliferation/drug effectsABSTRACT
The immune system maintains constant surveillance to prevent the infiltration of both endogenous and exogenous threats into host organisms. The process is regulated by effector immune cells that combat external pathogens and regulatory immune cells that inhibit excessive internal body inflammation, ultimately establishing a state of homeostasis within the body. Disruption to this process could lead to autoimmunity, which is often associated with the malfunction of both T cells and B cells with T cells playing a more major role. A number of therapeutic mediators for autoimmune diseases are available, from conventional disease-modifying drugs to biologic agents and small molecule inhibitors. Recently, ribosomally synthesized peptides, specifically cyclotides from plants are currently attracting more attention as potential autoimmune disease therapeutics due to their decreased toxicity compared to small molecules inhibitors as well as their remarkable stability against a number of factors. This review provides a concise overview of various cyclotides exhibiting immunomodulatory properties and their potential as therapeutic interventions for autoimmune diseases.
Subject(s)
Autoimmune Diseases , Cyclotides , Humans , Autoimmune Diseases/drug therapy , Autoimmune Diseases/immunology , Cyclotides/therapeutic use , Cyclotides/chemistry , Cyclotides/pharmacology , Immunosuppressive Agents/therapeutic use , Immunosuppressive Agents/pharmacology , AnimalsABSTRACT
The glutaminase enzymes GAC and GLS2 catalyze the hydrolysis of glutamine to glutamate, satisfying the 'glutamine addiction' of cancer cells. They are the targets of anti-cancer drugs; however, their mechanisms of activation and catalytic activity have been unclear. Here we demonstrate that the ability of GAC and GLS2 to form filaments is directly coupled to their catalytic activity and present their cryo-EM structures which provide a view of the conformational states essential for catalysis. Filament formation guides an 'activation loop' to assume a specific conformation that works together with a 'lid' to close over the active site and position glutamine for nucleophilic attack by an essential serine. Our findings highlight how ankyrin repeats on GLS2 regulate enzymatic activity, while allosteric activators stabilize, and clinically relevant inhibitors block, filament formation that enables glutaminases to catalyze glutaminolysis and support cancer progression.
Subject(s)
Glutaminase , Neoplasms , Glutamine , Cytoskeleton , Catalysis , Glutamic AcidABSTRACT
The human CC chemokine receptor 8 (CCR8) has been extensively pursued as target for the treatment of various inflammatory disorders. More recently, the importance of CCR8 in the tumor microenvironment has been demonstrated, spurring the interest in CCR8 antagonism as therapeutic strategy in immuno-oncology. On a previously described naphthalene sulfonamide with CCR8 antagonistic properties, the concept of isosterism was applied, leading to the discovery of novel CCR8 antagonists with IC50 values in the nM range in both the CCL1 competition binding and CCR8 calcium mobilization assay. The excellent CCR8 antagonistic activity of the most potent congeners was rationalized by homology molecular modeling.
Subject(s)
Chemokines, CC , Receptors, Chemokine , Humans , Chemokines, CC/metabolism , Chemokine CCL1/metabolism , Receptors, Chemokine/chemistry , Receptors, Chemokine/metabolism , Amides , Receptors, CCR8 , Sulfonamides/pharmacology , Naphthalenes/pharmacologyABSTRACT
Five coumarins were isolated from the heartwood of Mansonia gagei, which included two newly discovered compounds, namely 11-hydroxypopulene E (1) and mansorin D (2), along with three previously identified compounds. The structures were determined through the utilisation of comprehensive spectroscopic data, ECD calculations, and a thorough comparison with existing literature data. The α-glucosidase inhibitory activities of all isolated compounds were assessed in yeast. Out of the compounds tested, compound 2 exhibited the most significant activity, displaying a percentage inhibition of 34.33% at a concentration of 200 µM.
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PURPOSE: In the aftermath of a nuclear disaster or accident, survivors will suffer from radiation-induced normal tissue damage. Recovery after radiation exposure is dictated by several factors, one of which is degree of shielding at time of exposure. This study aims to characterize the short and late term changes in kinetics and magnitude of pancytopenia and blood chemistry in a model of heterogeneous radiation exposure, or partial body irradiation (PBI), compared to whole body irradiation (WBI). MATERIALS AND METHODS: Male C57BL/6 mice, 8-10 weeks of age, were WBI at 6 different doses (6, 6.1. 6.15, 6.2, 6.5, and 7.5 Gy) to establish the LD50. To determine the effect of shielding on blood cell counts and chemistry, animals were either WBI at 6 Gy (LD2230) or 6 Gy PBI with one leg shielding (LD030). Complete blood counts and chemistry were measured at 1, 5-, 10-, 20-, 30- and 120-days post-irradiation. RESULTS AND CONCLUSIONS: Irradiated animals had significant depletion of white blood cells, red blood cells and platelets up to 10 days post-irradiation. Separation between PBI and WBI were observed at 10- and 20-days post-irradiation at which point PBI animals showed sign of recovery while overall cell count remains depleted in WBI animals up to 30 days post-irradiation. In addition, significant changes were found in parameters indicative of hematopoietic injury including hemoglobin count, hematocrit count and white blood cell population. Significant changes were observed in kidney function with changes to blood urea nitrogen and calcium concentration at 5-days post-irradiation. At 10-days post-irradiation. liver function changes differentiated WBI from PBI animals. Long-term, irradiated animal's chemistry values and many blood counts were not significantly different from Sham. In conclusion, partial shielding ensured complete survival and demonstrated a different recovery kinetics of blood and chemistry parameters after irradiation compared to survivors of whole body irradiation and no single hemopoietic parameter was able to consistently differentiate irradiated from Sham animals. This seems to indicate that there is no single robust hemopoietic parameter to differentiate those exposed from those who were not due to the inherent variability in individual responses. Furthermore, there were no significant long-term effects on these blood parameters between survivors of WBI and PBI except that shielding accelerated recovery.
Subject(s)
Leukocytes , Radiation Exposure , Mice , Male , Animals , Mice, Inbred C57BL , Blood Cell Count , Radiation Dosage , Whole-Body Irradiation/adverse effectsABSTRACT
Chemical pesticides remain the predominant method for pest management in numerous countries. Given the current landscape of agriculture, the development of biopesticides has become increasingly crucial. The strategy empowers farmers to efficiently manage pests and diseases, while prioritizing minimal adverse effects on the environment and human health, hence fostering sustainable management. In recent years, there has been a growing interest and optimism surrounding the utilization of peptide biopesticides for crop protection. These sustainable and environmentally friendly substances have been recognized as viable alternatives to synthetic pesticides due to their outstanding environmental compatibility and efficacy. Numerous studies have been conducted to synthesize and identify peptides that exhibit activity against significant plant pathogens. One of the peptide classes is cyclotides, which are cyclic cysteine-rich peptides renowned for their wide range of sequences and functions. In this review, we conducted a comprehensive analysis of cyclotides, focusing on their structural attributes, developmental history, significant biological functions in crop protection, techniques for identification and investigation, and the application of biotechnology to enhance cyclotide synthesis. The objective is to emphasize the considerable potential of cyclotides as the next generation of plant protection agents on the global scale.
Subject(s)
Agriculture , Cyclotides , Cyclotides/chemistry , Agriculture/methods , Biological Control Agents/chemistry , Pesticides/chemistry , HumansABSTRACT
The biomedical field faces an ongoing challenge in developing more effective anti-cancer medication due to the significant burden that cancer poses on human health. Extensive research has been conducted on the utilization of natural polysaccharides in nanomedicine owing to their properties of biocompatibility, biodegradability, non-immunogenicity, and non-toxicity. These characteristics make them a potent drug delivery system for cancer therapy. The chitosan hyaluronic acid nanoparticle (CSHANp) system, consisting of chitosan and hyaluronic acid nanoparticles, has exhibited considerable potential as a nanocarrier for various cancer drugs, rendering it one of the most auspicious systems presently accessible. The CSHANps demonstrate remarkable drug loading capacity, precise control over drug release, and exceptional selectivity towards cancer cells. These properties enhance the therapeutic effectiveness against cancerous cells. This article aims to provide a comprehensive analysis of CSHANp, focusing on its characteristics, production techniques, applications, and future prospects.
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BACKGROUND: Children are especially vulnerable to Toxocara infection and its severe complications; however, there have not been any published data on the disease prevalence and treatment effectiveness in the population of Vietnamese children. This study was conducted to determine the prevalence of toxocariasis and explore factors associated with Toxocara infection in children aged 3-15 y in Ho Chi Minh City, Vietnam. METHODS: We conducted a cross-sectional study using a multistage cluster sampling approach in public schools. Blood samples were collected, and toxocariasis cases were confirmed, based on a history of contact with dogs/cats and positive anti-Toxocara antibody detection via ELISA. We calculated the percentage of seropositive children across gender, grade levels, districts and caregiver education. Multiple regression models were employed to identify potential risk factors. RESULTS: Anti-Toxocara antibodies were found in 14.2% of the 986 children studied. Significant variations in seropositivity were observed across grade levels, districts and caregiver education levels. Multivariable analysis identified caregiver education, contact with dogs/cats and improper handling of pet feces as seropositivity risk factors. CONCLUSION: This was the first community-based prevalence study of toxocariasis in a pediatric population in Vietnam. Implementation of preventive measures such as public education, routine fecal examinations and chemotherapeutic treatment of animals is highly recommended.
Subject(s)
Toxocara , Toxocariasis , Humans , Vietnam/epidemiology , Child , Toxocariasis/epidemiology , Cross-Sectional Studies , Male , Female , Animals , Adolescent , Risk Factors , Child, Preschool , Dogs , Seroepidemiologic Studies , Toxocara/immunology , Cats , Antibodies, Helminth/blood , Enzyme-Linked Immunosorbent Assay , Prevalence , SchoolsABSTRACT
Cyclotides, plant-derived cysteine-rich peptides, exhibit a wide range of beneficial biological activities and possess exceptional structural stability. Cyclotides are commonly distributed throughout the Violaceae family. Viola dalatensis Gagnep, a Vietnamese species, has not been well studied, especially for cyclotides. This pioneering research explores cyclotides from V. dalatensis as antimicrobials. This study used a novel approach to enhance cyclotides after extraction. The approach combined 30% ammonium sulfate salt precipitation and RP-HPLC. A comprehensive analysis was performed to ascertain the overall protein content, flavonoids content, polyphenol content, and free radical scavenging capacity of compounds derived from V. dalatensis. Six known cyclotides were sequenced utilizing MS tandem. Semi-purified cyclotide mixtures (M1, M2, and M3) exhibited antibacterial efficacy against Bacillus subtilis (inhibitory diameters: 19.67-23.50 mm), Pseudomonas aeruginosa (22.17-23.50 mm), and Aspergillus flavus (14.67-21.33 mm). The enriched cyclotide precipitate from the stem extract demonstrated a minimum inhibitory concentration (MIC) of 0.08 mg/mL against P. aeruginosa, showcasing significant antibacterial effectiveness compared to the stem extract (MIC: 12.50 mg/mL). Considerable advancements have been achieved in the realm of cyclotides, specifically in their application as antimicrobial agents.
Subject(s)
Cyclotides , Viola , Cyclotides/pharmacology , Cyclotides/chemistry , Viola/chemistry , Viola/metabolism , Plant Extracts/pharmacology , Plant Extracts/chemistry , Anti-Bacterial Agents/chemistry , VietnamABSTRACT
Some of the most metabolically diverse species of bacteria (e.g., Actinobacteria) have higher GC content in their DNA, differ substantially in codon usage, and have distinct protein folding environments compared to tractable expression hosts like Escherichia coli. Consequentially, expressing biosynthetic gene clusters (BGCs) from these bacteria in E. coli frequently results in a myriad of unpredictable issues with protein expression and folding, delaying the biochemical characterization of new natural products. Current strategies to achieve soluble, active expression of these enzymes in tractable hosts, such as BGC refactoring, can be a lengthy trial-and-error process. Cell-free expression (CFE) has emerged as 1) a valuable expression platform for enzymes that are challenging to synthesize in vivo, and as 2) a testbed for rapid prototyping that can improve cellular expression. Here, we use a type III polyketide synthase from Streptomyces griseus, RppA, which catalyzes the formation of the red pigment flaviolin, as a reporter to investigate BGC refactoring techniques. We synergistically tune promoter and codon usage to improve flaviolin production from cell-free expressed RppA. We then assess the utility of cell-free systems for prototyping these refactoring tactics prior to their implementation in cells. Overall, codon harmonization improves natural product synthesis more than traditional codon optimization across cell-free and cellular environments. Refactoring promoters and/or coding sequences via CFE can be a valuable strategy to rapidly screen for catalytically functional production of enzymes from BCGs. By showing the coordinators between CFE versus in vivo expression, this work advances CFE as a tool for natural product research.
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Objectives: Classroom-based learning such as academic half days (AHDs) are complementary to workplace learning in postgraduate medical education. This study examined three research questions: the purpose of AHDs, elements of an effective AHD, and factors that make AHD sustainable. Methods: We conducted a case study of the AHD in a large Obstetrics and Gynecology residency program at the University of British Columbia. Residents were interviewed in 2013 (n = 11) and 2018 (n = 7) and the program administrator was interviewed in 2018. The themes in each research question were identified by modified inductive analysis. Results: Residents expressed that the purposes of AHD included: providing organization and an overview for their knowledge acquisition; preparation for their Royal College specialty exam; and to provide a venue for peer support and mentorship. Elements of an effective AHD include the repetition of key concepts; formative assessments such as quizzes, a suitable balance of faculty input and resident active participation, and protection from clinical duty during AHD. Regarding the sustainability of AHD, themes included: addressing barriers to faculty participation, providing administrative support for logistical needs, and providing feedback to faculty. Conclusions: This work provides important insights into the purpose, effectiveness, and sustainability of AHDs for those who design and implement classroom learning for residents.
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This paper describes the protocol for a Phase I/II, parallel-group, blinded randomized controlled trial that compares the effects of 12-weeks of combined learning and memory rehabilitation with either aerobic cycling exercise or stretching on cognitive, neuroimaging, and everyday life outcomes in 60 persons with moderate-to-severe traumatic brain injury (TBI) who demonstrate impairments in new learning. Briefly, participants will undergo baseline testing consisting of neuropsychological testing, neuroimaging, daily life measures, and cardiorespiratory fitness. Following baseline testing, participants will be randomized to one of 2 conditions (30 participants per condition) using concealed allocation. Participants will be masked as to the intent of the conditions. The conditions will both involve supervised administration of an enhanced, 8-week version of the Kessler Foundation modified Story Memory Technique, embedded within either 12-weeks of supervised and progressive aerobic cycling exercise training (experimental condition) or 12-weeks of supervised stretching-and-toning (active control condition). Following the 12-week intervention period, participants will complete the same measures as at baseline that will be administered by treatment-blinded assessors. The primary study outcome is new learning and memory impairment based on California Verbal Learning Test (CVLT)-III slope, the secondary outcomes include neuroimaging measures of hippocampal volume, activation, and connectivity, and the tertiary outcomes involve measures of daily living along with other cognitive outcomes. We further will collect baseline sociodemographic data for examining predictors of response heterogeneity. If successful, this trial will provide the first Class I evidence supporting combined memory rehabilitation and aerobic cycling exercise training for treating TBI-related new learning and memory impairment.
Subject(s)
Brain Injuries, Traumatic , Cognitive Training , Humans , Exercise , Brain Injuries, Traumatic/psychology , Exercise Therapy/methods , Memory , Treatment Outcome , Randomized Controlled Trials as Topic , Clinical Trials, Phase I as TopicABSTRACT
High GC bacteria from the genus Streptomyces harbor expansive secondary metabolism. The expression of biosynthetic proteins and the characterization and identification of biological "parts" for synthetic biology purposes from such pathways are of interest. However, the high GC content of proteins from actinomycetes in addition to the large size and multi-domain architecture of many biosynthetic proteins (such as non-ribosomal peptide synthetases; NRPSs, and polyketide synthases; PKSs often called "megasynthases") often presents issues with full-length translation and folding. Here we evaluate a non-ribosomal peptide synthetase (NRPS) from Streptomyces lavenduale, a multidomain "megasynthase" gene that comes from a high GC (72.5%) genome. While a preliminary step in revealing differences, to our knowledge this presents the first head-to-head comparison of codon-optimized sequences versus a native sequence of proteins of streptomycete origin heterologously expressed in E. coli. We found that any disruption in co-translational folding from codon mismatch that reduces the titer of indigoidine is explainable via the formation of more inclusion bodies as opposed to compromising folding or posttranslational modification in the soluble fraction. This result supports that one could apply any refactoring strategies that improve soluble expression in E. coli without concern that the protein that reaches the soluble fraction is differentially folded.
Subject(s)
Streptomyces , Streptomyces/genetics , Streptomyces/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Peptide Synthases/genetics , Peptide Synthases/metabolism , Recombinant Proteins/genetics , Multigene FamilyABSTRACT
Of the 265 known bumble bee (Bombus) species, knowledge of colony lifecycle is derived from relatively few species. As interest in Bombus commercialization and conservation grows, it is becoming increasingly important to understand colony growth dynamics across a variety of species since variation exists in nest success, colony growth, and reproductive output. In this study, we reported successful nest initiation and establishment rates of colonies and generated a timeline of colony development for 15 western North American Bombus species, which were captively reared from wild-caught gynes from 2009 to 2019. Additionally, we assessed variation in colony size among 5 western North American Bombus species from 2015 to 2018. Nest initiation and establishment rates varied greatly among species, ranging from 5-76.1% and 0-54.6%, respectively. Bombus griseocollis had the highest rates of nest success across the 11-yr period, followed by B. occidentalis, B. vosnesenskii, and B. huntii. Furthermore, days to nest initiation and days to nest establishment varied among species, ranging from 8.4 to 27.7 days and 32.7 to 47 days. Colony size also differed significantly among species with B. huntii and B. vosnesenskii producing more worker/drone cells than B. griseocollis, B. occidentalis, and B. vancouverensis. Additionally, gyne production differed significantly among species with B. huntii colonies producing more gynes than B. vosnesenskii. Results from this study increase knowledge of systematic nesting biology for numerous western North American Bombus species under captive rearing conditions, which can further improve rearing techniques available to conservationists and researchers.