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1.
Front Public Health ; 12: 1358010, 2024.
Article in English | MEDLINE | ID: mdl-38721534

ABSTRACT

Purpose: Tuberculosis (TB) is linked to sustained inflammation even after treatment, and fracture risk is higher in TB survivors than in the general population. However, no individualized fracture risk prediction model exists for TB survivors. We aimed to estimate fracture risk, identify fracture-related factors, and develop an individualized risk prediction model for TB survivors. Methods: TB survivors (n = 44,453) between 2010 and 2017 and 1:1 age- and sex-matched controls were enrolled. One year after TB diagnosis, the participants were followed-up until the date of fracture, death, or end of the study period (December 2018). Cox proportional hazard regression analyses were performed to compare the fracture risk between TB survivors and controls and to identify fracture-related factors among TB survivors. Results: During median 3.4 (interquartile range, 1.6-5.3) follow-up years, the incident fracture rate was significantly higher in TB survivors than in the matched controls (19.3 vs. 14.6 per 1,000 person-years, p < 0.001). Even after adjusting for potential confounders, TB survivors had a higher risk for all fractures (adjusted hazard ratio 1.27 [95% confidence interval 1.20-1.34]), including hip (1.65 [1.39-1.96]) and vertebral (1.35 [1.25-1.46]) fractures, than matched controls. Fracture-related factors included pulmonary TB, female sex, older age, heavy alcohol consumption, reduced exercise, and a higher Charlson Comorbidity Index (p < 0.05). The individualized fracture risk model showed good discrimination (concordance statistic = 0.678). Conclusion: TB survivors have a higher fracture risk than matched controls. An individualized prediction model may help prevent fractures in TB survivors, especially in high-risk groups.


Subject(s)
Osteoporotic Fractures , Tuberculosis , Humans , Female , Male , Middle Aged , Osteoporotic Fractures/epidemiology , Tuberculosis/epidemiology , Tuberculosis/complications , Aged , Risk Factors , Risk Assessment , Cohort Studies , Adult , Proportional Hazards Models , Taiwan/epidemiology
2.
Nat Commun ; 13(1): 7554, 2022 12 07.
Article in English | MEDLINE | ID: mdl-36477674

ABSTRACT

Antibodies are essential biological research tools and important therapeutic agents, but some exhibit non-specific binding to off-target proteins and other biomolecules. Such polyreactive antibodies compromise screening pipelines, lead to incorrect and irreproducible experimental results, and are generally intractable for clinical development. Here, we design a set of experiments using a diverse naïve synthetic camelid antibody fragment (nanobody) library to enable machine learning models to accurately assess polyreactivity from protein sequence (AUC > 0.8). Moreover, our models provide quantitative scoring metrics that predict the effect of amino acid substitutions on polyreactivity. We experimentally test our models' performance on three independent nanobody scaffolds, where over 90% of predicted substitutions successfully reduced polyreactivity. Importantly, the models allow us to diminish the polyreactivity of an angiotensin II type I receptor antagonist nanobody, without compromising its functional properties. We provide a companion web-server that offers a straightforward means of predicting polyreactivity and polyreactivity-reducing mutations for any given nanobody sequence.


Subject(s)
Immunoglobulin Fragments
3.
Sensors (Basel) ; 22(24)2022 Dec 13.
Article in English | MEDLINE | ID: mdl-36560127

ABSTRACT

In this study, we propose a single camera-based dual-channel near-infrared (NIR) fluorescence imaging system that produces color and dual-channel NIR fluorescence images in real time. To simultaneously acquire color and dual-channel NIR fluorescence images of two fluorescent agents, three cameras and additional optical parts are generally used. As a result, the volume of the image acquisition unit increases, interfering with movements during surgical procedures and increasing production costs. In the system herein proposed, instead of using three cameras, we set a single camera equipped with two image sensors that can simultaneously acquire color and single-channel NIR fluorescence images, thus reducing the volume of the image acquisition unit. The single-channel NIR fluorescence images were time-divided into two channels by synchronizing the camera and two excitation lasers, and the noise caused by the crosstalk effect between the two fluorescent agents was removed through image processing. To evaluate the performance of the system, experiments were conducted for the two fluorescent agents to measure the sensitivity, crosstalk effect, and signal-to-background ratio. The compactness of the resulting image acquisition unit alleviates the inconvenient movement obstruction of previous devices during clinical and animal surgery and reduces the complexity and costs of the manufacturing process, which may facilitate the dissemination of this type of system.


Subject(s)
Fluorescent Dyes , Indocyanine Green , Animals , Optical Imaging/methods , Image Processing, Computer-Assisted , Fluorescence
4.
Biomedicines ; 10(4)2022 Apr 07.
Article in English | MEDLINE | ID: mdl-35453613

ABSTRACT

Paclitaxel is a widely used anticancer drug that induces dose-limiting peripheral neuropathy. Mitochondrial dysfunction has been implicated in paclitaxel-induced neuronal damage and in the onset of peripheral neuropathy. We have previously shown that the expression of PINK1, a key mediator of mitochondrial quality control, ameliorated the paclitaxel-induced thermal hyperalgesia phenotype and restored mitochondrial homeostasis in Drosophila larvae. In this study, we show that the small-molecule PINK1 activator niclosamide exhibits therapeutic potential for paclitaxel-induced peripheral neuropathy. Specifically, niclosamide cotreatment significantly ameliorated the paclitaxel-induced thermal hyperalgesia phenotype in Drosophila larvae in a PINK1-dependent manner. Paclitaxel-induced alteration of the dendrite structure of class IV dendritic arborization (C4da) neurons was not reduced upon niclosamide treatment. In contrast, paclitaxel treatment-induced increases in both mitochondrial ROS and aberrant mitophagy levels in C4da neurons were significantly suppressed by niclosamide. In addition, niclosamide suppressed paclitaxel-induced mitochondrial dysfunction in human SH-SY5Y cells in a PINK1-dependent manner. These results suggest that niclosamide alleviates thermal hyperalgesia by attenuating paclitaxel-induced mitochondrial dysfunction. Taken together, our results suggest that niclosamide is a potential candidate for the treatment of paclitaxel-induced peripheral neuropathy with low toxicity in neurons and that targeting mitochondrial dysfunction is a promising strategy for the treatment of chemotherapy-induced peripheral neuropathy.

5.
J Pers Med ; 12(4)2022 Mar 30.
Article in English | MEDLINE | ID: mdl-35455663

ABSTRACT

Background: Non-alcoholic fatty liver disease (NAFLD) is regarded as a risk factor for type 2 diabetes mellitus (DM). Menopausal status also influences T2DM risk, where estrogen is presumed to play a protective role by decreasing insulin resistance. As such, we investigated the association between NAFLD and DM risk according to menopausal status. Objectives: We sought to examine the association between NAFLD and DM incidence in pre- and post-menopausal women. Methods: A total of 842,772 pre-menopausal and 1,074,767 post-menopausal women who underwent health examinations between 2009 and 2014 were included from the Korean National Health Insurance Service database. Multivariate Cox proportional hazard analyses were performed to evaluate the association between the risk of DM according to menopausal status and NAFLD, defined by a fatty liver index >60. Results: During the mean follow-up period (7.8 years), DM was diagnosed in 33,461 (4.0%) of pre-menopausal women and 121,102 (9.4%) post-menopausal women. A stronger association between NAFLD and the risk of DM was found in pre-menopausal women (multivariable-adjusted hazard ratio [aHR], 3.60; 95% confidence interval [CI], 3.48−3.71) than in post-menopausal women (aHR, 2.24; 95% CI, 2.21−2.28) (P-interaction < 0.01). Subgroup analyses among women aged 45 to 55 years also showed a stronger association in pre-menopausal (aHR, 3.35; 95% CI, 3.21−3.49) than in post-menopausal women (aHR, 2.83; 95% CI, 2.68−2.98) (P-interaction < 0.01). Conclusions: The association between NAFLD and DM was stronger in pre-menopausal women than in post-menopausal women. This might be due to the protective effect of estrogen, which is possibly in higher production in the peripheral fat tissue of post-menopausal women with NAFLD.

6.
J Clin Med ; 10(21)2021 Nov 06.
Article in English | MEDLINE | ID: mdl-34768709

ABSTRACT

Although both obesity and menopause are associated with increased risk of diabetes mellitus (DM), the association between obesity and DM according to menopausal status remains uncertain. Therefore, we conducted a study to examine the relationship between obesity and incidence of diabetes mellitus (DM) in premenopausal and postmenopausal women. Total of 926,196 premenopausal and 1,193,881 postmenopausal women who underwent health examinations from 2009 to 2014 were identified using the database of the Korean National Health Insurance Service. We compared the incidence and risk of DM according to body mass index (BMI) and waist circumference (WC) in the two groups of women. Cox proportional hazards analyses were performed to evaluate the association between the presence of obesity and risk of DM according to menopausal state. During the 7.8-year follow-up period, 37,736 (4.1%) premenopausal women and 121,102 (10.1%) postmenopausal women were diagnosed with DM. Compared to the reference group (BMI 18.5-23), a stronger association between obesity and risk of DM was observed in both pre- and postmenopausal women: multivariable-adjusted hazard ratios and 95% confidence intervals for BMI subgroups <18.5, 23-25, 25-30, and >30 were 0.62 (0.54, 0.70), 1.91 (1.85, 1.97), 3.38 (3.28, 3.47), and 6.25 (6.02, 6.48), respectively (p trend < 0.001) in premenopausal women and 0.87 (0.82, 0.92), 1.44 (1.41, 1.46), 2.00 (1.97, 2.03), and 2.96 (2.89, 3.02) in postmenopausal women (p trend < 0.001, p-interaction < 0.001). A similar trend was observed for WC. Subgroup analyses of women aged 45 to 55 also showed a stronger association with DM in premenopausal than in postmenopausal women. In conclusion, the association between obesity and DM was stronger in premenopausal women than in postmenopausal women. As estrogens are synthesized in adipose tissue by aromatization of androgens after menopause, increased estrogen levels in obese postmenopausal might have a protective effect against DM.

7.
Nat Chem Biol ; 17(10): 1057-1064, 2021 10.
Article in English | MEDLINE | ID: mdl-34168368

ABSTRACT

The predominant approach for antibody generation remains animal immunization, which can yield exceptionally selective and potent antibody clones owing to the powerful evolutionary process of somatic hypermutation. However, animal immunization is inherently slow, not always accessible and poorly compatible with many antigens. Here, we describe 'autonomous hypermutation yeast surface display' (AHEAD), a synthetic recombinant antibody generation technology that imitates somatic hypermutation inside engineered yeast. By encoding antibody fragments on an error-prone orthogonal DNA replication system, surface-displayed antibody repertoires continuously mutate through simple cycles of yeast culturing and enrichment for antigen binding to produce high-affinity clones in as little as two weeks. We applied AHEAD to generate potent nanobodies against the SARS-CoV-2 S glycoprotein, a G-protein-coupled receptor and other targets, offering a template for streamlined antibody generation at large.


Subject(s)
Antibody Formation/immunology , Protein Engineering/methods , Recombinant Proteins/biosynthesis , Antibodies/immunology , Antigens , COVID-19/immunology , Humans , Peptide Library , Recombinant Proteins/metabolism , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Saccharomyces cerevisiae/metabolism , Single-Domain Antibodies/genetics , Single-Domain Antibodies/metabolism , Spike Glycoprotein, Coronavirus/immunology
8.
Front Public Health ; 9: 641140, 2021.
Article in English | MEDLINE | ID: mdl-33842422

ABSTRACT

Objectives: Adolescents in multicultural families (AMFs) are exposed to numerous stressors and face environmental vulnerability within the family, school, and community systems, which may affect their health and well-being. Concrete discussion on policies is lacking due to insufficient data on the levels of well-being of AMFs in South Korea. This study aimed to investigate social-cultural and community factors affecting their well-being. Methods: A cross-sectional study was conducted with a convenience sample of 206 AMFs (aged 13-18 years) from 16 general schools and three multicultural schools across eight large cities. AMFs completed a self-administrative questionnaire assessing well-being, individual factors (acculturative stress, health behavior), social and community factors (social support, sense of community), and environmental factors (school type, economic status). Data were analyzed using structural equation modeling. Results: Social support and sense of community significantly and directly affected well-being. The economic status and type of school had an indirect effect on well-being, whereas the effect of acculturative stress was not significant. Factors significantly affecting adolescents' well-being were social support, sense of community, economic status, and type of school. Conclusion: Addressing well-being may be the strategy leading AMFs to grow into healthy adults. These results could help educators, health professionals, and policymakers to identify ways to enhance the well-being of AMFs.


Subject(s)
Cultural Diversity , Social Determinants of Health , Adolescent , Adult , Cities , Cross-Sectional Studies , Humans , Republic of Korea/epidemiology
9.
Nat Commun ; 12(1): 2403, 2021 04 23.
Article in English | MEDLINE | ID: mdl-33893299

ABSTRACT

The ability to design functional sequences and predict effects of variation is central to protein engineering and biotherapeutics. State-of-art computational methods rely on models that leverage evolutionary information but are inadequate for important applications where multiple sequence alignments are not robust. Such applications include the prediction of variant effects of indels, disordered proteins, and the design of proteins such as antibodies due to the highly variable complementarity determining regions. We introduce a deep generative model adapted from natural language processing for prediction and design of diverse functional sequences without the need for alignments. The model performs state-of-art prediction of missense and indel effects and we successfully design and test a diverse 105-nanobody library that shows better expression than a 1000-fold larger synthetic library. Our results demonstrate the power of the alignment-free autoregressive model in generalizing to regions of sequence space traditionally considered beyond the reach of prediction and design.


Subject(s)
Algorithms , Computational Biology/methods , Neural Networks, Computer , Protein Engineering/methods , Amino Acid Sequence , Antibodies/genetics , Antibodies/immunology , Antibodies/metabolism , Antigens/immunology , Genotype , Humans , Mutation , Phenotype , Proteins/genetics , Proteins/immunology , Proteins/metabolism
10.
J Pers Med ; 12(1)2021 Dec 21.
Article in English | MEDLINE | ID: mdl-35055319

ABSTRACT

Prostate cancer is the fourth most common cause of cancer in men in Korea, and there has been a rapid increase in cases. In the present study, we constructed a risk prediction model for prostate cancer using representative data from Korea. Participants who completed health examinations in 2009, based on the Korean National Health Insurance database, were eligible for the present study. The crude and adjusted risks were explored with backward selection using the Cox proportional hazards model to identify possible risk variables. Risk scores were assigned based on the adjusted hazard ratios, and the standardized points for each risk factor were proportional to the ß-coefficient. Model discrimination was assessed using the concordance statistic (c-statistic), and calibration ability was assessed by plotting the mean predicted probability against the mean observed probability of prostate cancer. Among the candidate predictors, age, smoking intensity, body mass index, regular exercise, presence of type 2 diabetes mellitus, and hypertension were included. Our risk prediction model showed good discrimination (c-statistic: 0.826, 95% confidence interval: 0.821-0.832). The relationship between model predictions and actual prostate cancer development showed good correlation in the calibration plot. Our prediction model for individualized prostate cancer risk in Korean men showed good performance. Using easily accessible and modifiable risk factors, this model can help individuals make decisions regarding prostate cancer screening.

11.
bioRxiv ; 2020 Nov 11.
Article in English | MEDLINE | ID: mdl-33200136

ABSTRACT

The predominant approach for antibody generation remains animal immunization, which can yield exceptionally selective and potent antibody clones owing to the powerful evolutionary process of somatic hypermutation. However, animal immunization is inherently slow, has poor compatibility with certain antigens ( e . g ., integral membrane proteins), and suffers from self-tolerance and immunodominance, which limit the functional spectrum of antibodies that can be obtained. Here, we describe A utonomous H ypermutation y E ast surf A ce D isplay (AHEAD), a synthetic recombinant antibody generation technology that imitates somatic hypermutation inside engineered yeast. In AHEAD, antibody fragments are encoded on an error-prone orthogonal DNA replication system, resulting in Saccharomyces cerevisiae populations that continuously mutate surface-displayed antibody repertoires. Simple cycles of yeast culturing and enrichment for antigen binding drive the evolution of high-affinity antibody clones in a readily parallelizable process that takes as little as 2 weeks. We applied AHEAD to generate nanobodies against the SARS-CoV-2 S glycoprotein, a GPCR, and other targets. The SARS-CoV-2 nanobodies, concurrently evolved from an open-source naïve nanobody library in 8 independent experiments, reached subnanomolar affinities through the sequential fixation of multiple mutations over 3-8 AHEAD cycles that saw ∼580-fold and ∼925-fold improvements in binding affinities and pseudovirus neutralization potencies, respectively. These experiments highlight the defining speed, parallelizability, and effectiveness of AHEAD and provide a template for streamlined antibody generation at large with salient utility in rapid response to current and future viral outbreaks.

12.
Arch Psychiatr Nurs ; 31(6): 588-595, 2017 12.
Article in English | MEDLINE | ID: mdl-29179826

ABSTRACT

The purposes of this study were to identify correlations between body mass index, body image, and self-esteem in patients with schizophrenia and to analyse the specific factors affecting self-esteem. This study had a descriptive design, utilising a cross-sectional survey. Participants were patients with schizophrenia who were admitted to a mental health facility in South Korea. A total of 180 questionnaires were distributed, and an appropriate total sample size of 167 valid questionnaires was analysed. Self-esteem was significantly correlated with body image, the subscale of appearance orientation, and body areas satisfaction. However, body mass index exhibited no significant correlation with any variable. The variables found to have a significant explanatory power of 21.4% were appearance orientation and body areas satisfaction. The explanatory power of all factors was 33.6%. The self-esteem of patients with schizophrenia was influenced by body mass index and body image. The positive symptoms of schizophrenia can be controlled by medication, whereas negative symptoms can be improved through education and nursing care with medication. Thus, psychiatric nurses should develop education and care programs that contribute to the positive body image and self-esteem of patients with schizophrenia.


Subject(s)
Body Image , Body Mass Index , Schizophrenia , Self Concept , Adult , Antipsychotic Agents/therapeutic use , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Psychiatric Nursing/methods , Republic of Korea , Schizophrenia/drug therapy , Surveys and Questionnaires
13.
J Affect Disord ; 214: 53-59, 2017 May.
Article in English | MEDLINE | ID: mdl-28266321

ABSTRACT

BACKGROUND: Previous studies on patients diagnosed with social anxiety disorder (SAD) reported changed patterns of the resting-state functional connectivity network (rs-FCN) between the prefrontal cortices and other prefrontal, amygdalar or striatal regions. Using a graph theory approach, this study explored the modularity-based community profile and patterns of inter-/intra-modular communication for the rs-FCN in SAD. METHODS: In total, for 28 SAD patients and 27 healthy controls (HC), functional magnetic resonance imaging (fMRI) data were acquired in resting-state and subjected to a graph theory analysis. RESULTS: The within-module degree z-score for a hub region [out of a total of 10 hub regions ranked using the participation coefficient] named left middle temporal gyrus was impaired in SAD compared to HC, proportional to the severity of clinician-scored and patient-reported functional impairment in SAD. LIMITATIONS: Most of participants included in this study were undergraduate students in their early-to-mid 20's. CONCLUSIONS: This study showed the importance of functional communication from the left middle temporal gyrus with other opercular-insular-subcortical regions for better objective functioning and lesser subjective disability in SAD.


Subject(s)
Phobia, Social/physiopathology , Temporal Lobe/physiopathology , Adult , Amygdala/physiopathology , Brain/physiopathology , Brain Mapping/methods , Cerebral Cortex/physiopathology , Corpus Striatum/physiopathology , Female , Humans , Magnetic Resonance Imaging , Male , Prefrontal Cortex/physiopathology
14.
Nucleic Acids Res ; 44(9): 4460-71, 2016 05 19.
Article in English | MEDLINE | ID: mdl-27084942

ABSTRACT

Horizontal gene transfer (HGT) is the non-inherited acquisition of novel DNA sequences. HGT is common and important in bacteria because it enables the rapid generation of new phenotypes such as antibiotic resistance. Here we show that in vivo and in vitro DNA methylation patterns can be horizontally transferred into bacterial chromosomes to program cell phenotypes. The experiments were performed using a synthetic system in Escherichia coli where different DNA methylation patterns within the cis-regulatory sequence of the agn43 gene turn on or off a fluorescent reporter (CFP). With this system we demonstrated that DNA methylation patterns not only accompany the horizontal transfer of genes into the bacterial cytoplasm but can be transferred into chromosomes by: (i) bacteriophage P1 transduction; and (ii) transformation of extracellular synthetic DNA. We also modified the experimental system by replacing CFP with the SgrS small RNA, which regulates glucose and methyl α-D-glucoside uptake, and showed that horizontally acquired DNA methylation patterns can increase or decrease cell fitness. That is, horizontally acquired DNA methylation patterns can result in the selection for and against cells that have HGT. Findings from these proof-of-concept experiments have applications in synthetic biology and potentially broad implications for bacterial adaptation and evolution.


Subject(s)
Chromosomes, Bacterial/genetics , DNA Methylation , Escherichia coli/genetics , Gene Transfer, Horizontal , Genes, Bacterial , DNA, Bacterial/genetics , Genetic Engineering
15.
J Psychiatr Res ; 75: 31-40, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26802808

ABSTRACT

In social anxiety disorder (SAD), anxiety reactions are triggered by attentional bias to social threats that automatically appear in social situations. The present study aimed to investigate the neural basis and underlying resting-state pathology of attentional bias toward internal and external social threats as a core element of SAD. Twenty-two patients with SAD and 20 control subjects scanned functional magnetic resonance imaging during resting-state and while performing the visual search task. During the task, participants were exposed to internal threat (hearing participants' own pulse-sounds) and external threat (crowds in facial matrices). Patients showed activations in the lateral orbitofrontal cortex, rostral anterior cingulate cortex and insula in response to internal threat and activations in the posterior cingulate cortex and middle temporal gyrus in response to external threat. In patients, neural activity related to combined internal and external threats in the posterior cingulate cortex was inversely correlated with the functional connectivity strengths with the default mode network during resting-state. These findings suggest that attentional bias may stem from limbic and paralimbic pathology, and the interactive process of internally- and externally-focused attentional bias in SAD is associated with the self-referential function of resting-state.


Subject(s)
Attention/physiology , Attentional Bias/physiology , Brain Mapping , Phobia, Social/diagnostic imaging , Self Concept , Adult , Analysis of Variance , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Oxygen/blood , Phobia, Social/physiopathology , Phobia, Social/psychology , Photic Stimulation , Rest , Statistics as Topic , Young Adult
16.
Nucleic Acids Res ; 43(17): 8502-15, 2015 Sep 30.
Article in English | MEDLINE | ID: mdl-26261213

ABSTRACT

Small RNAs (sRNAs) are important regulators of gene expression during bacterial stress and pathogenesis. sRNAs act by forming duplexes with mRNAs to alter their translation and degradation. In some bacteria, duplex formation is mediated by the Hfq protein, which can bind the sRNA and mRNA in each pair in a random order. Here we investigate the consequences of this random-order binding and experimentally demonstrate that it can counterintuitively cause high Hfq concentrations to suppress rather than promote sRNA activity in Escherichia coli. As a result, maximum sRNA activity occurs when the Hfq concentration is neither too low nor too high relative to the sRNA and mRNA concentrations ('Hfq set-point'). We further show with models and experiments that random-order binding combined with the formation of a dead-end mRNA-Hfq complex causes high concentrations of an mRNA to inhibit its own duplex formation by sequestering Hfq. In such cases, maximum sRNA activity requires an optimal mRNA concentration ('mRNA set-point') as well as an optimal Hfq concentration. The Hfq and mRNA set-points generate novel regulatory properties that can be harnessed by native and synthetic gene circuits to provide greater control over sRNA activity, generate non-monotonic responses and enhance the robustness of expression.


Subject(s)
Escherichia coli Proteins/metabolism , Gene Expression Regulation, Bacterial , Host Factor 1 Protein/metabolism , RNA, Small Untranslated/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Silencing , Protein Binding , RNA, Bacterial/metabolism , RNA, Messenger/metabolism
17.
Nat Commun ; 5: 4574, 2014 Aug 04.
Article in English | MEDLINE | ID: mdl-25087841

ABSTRACT

Mechanisms that control cell-to-cell variation in gene expression ('phenotypic variation') can determine a population's growth rate, robustness, adaptability and capacity for complex behaviours. Here we describe a general strategy (termed FABMOS) for tuning the phenotypic variation and mean expression of cell populations by modulating the frequency and bias of stochastic transitions between 'OFF' and 'ON' expression states of a genetic switch. We validated the strategy experimentally using a synthetic fim switch in Escherichia coli. Modulating the frequency of switching can generate a bimodal (low frequency) or a unimodal (high frequency) population distribution with the same mean expression. Modulating the bias as well as the frequency of switching can generate a spectrum of bimodal and unimodal distributions with the same mean expression. This remarkable control over phenotypic variation, which cannot be easily achieved with standard gene regulatory mechanisms, has many potential applications for synthetic biology, engineered microbial ecosystems and experimental evolution.


Subject(s)
Escherichia coli/genetics , Fimbriae, Bacterial/genetics , Gene Expression Regulation, Bacterial , Genes, Regulator , Models, Genetic , Computer Simulation , Escherichia coli/metabolism , Fimbriae, Bacterial/metabolism , Genotype , Phenotype , Stochastic Processes
18.
Comput Biol Med ; 49: 60-6, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24747729

ABSTRACT

Virtual reality has been used to measure abnormal social characteristics, particularly in one-to-one situations. In real life, however, conversations with multiple companions are common and more complicated than two-party conversations. In this study, we explored the features of social behaviors in patients with schizophrenia during virtual multiparty conversations. Twenty-three patients with schizophrenia and 22 healthy controls performed the virtual three-party conversation task, which included leading and aiding avatars, positive- and negative-emotion-laden situations, and listening and speaking phases. Patients showed a significant negative correlation in the listening phase between the amount of gaze on the between-avatar space and reasoning ability, and demonstrated increased gaze on the between-avatar space in the speaking phase that was uncorrelated with attentional ability. These results suggest that patients with schizophrenia have active avoidance of eye contact during three-party conversations. Virtual reality may provide a useful way to measure abnormal social characteristics during multiparty conversations in schizophrenia.


Subject(s)
Fixation, Ocular/physiology , Interpersonal Relations , Schizophrenia/epidemiology , Schizophrenic Psychology , User-Computer Interface , Adult , Computer Simulation , Female , Humans , Male , Social Behavior
19.
Environ Toxicol Pharmacol ; 36(2): 463-471, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23792233

ABSTRACT

All-trans retinoic acid (ATRA) is reported to reduce hair cell loss and hearing deterioration caused by noise-induced hearing loss (NIHL). The present study investigates the involvement of peroxiredoxin 6 (Prdx 6) in ATRA-mediated protection of temporary threshold shift of hearing. Mice fed with ATRA before or after exposure to white noise showed a faster recovery than untreated controls within 1 week, with a concomitant increase of cochlear Prdx 6 expression. Treatment of mouse auditory cells with ATRA induced Prdx 6 expression. A putative retinoic acid (RA)-response element (RARE) was identified in a murine Prdx 6 promoter region. Prdx 6 promoter activities were elevated in wild-type reporter plasmid-transfected cells, whereas no significant change in activity was in those with RARE-disrupted mutant reporter. RA receptor α (RARα) functions as a transactivator of Prdx 6 gene expression. These findings suggest that ATRA-induced Prdx 6 expression may be associated with rapid recovery from temporary NIHL.


Subject(s)
Auditory Fatigue/drug effects , Cochlea/drug effects , Hearing Loss, Noise-Induced/metabolism , Hearing/drug effects , Peroxiredoxin VI/metabolism , Tretinoin/pharmacology , Animals , Binding Sites , Cell Line , Cochlea/metabolism , Cochlea/physiopathology , Disease Models, Animal , Dose-Response Relationship, Drug , Hearing Loss, Noise-Induced/etiology , Hearing Loss, Noise-Induced/physiopathology , Mice , Mice, Inbred BALB C , Mutation , Peroxiredoxin VI/genetics , Promoter Regions, Genetic , Receptors, Retinoic Acid/agonists , Receptors, Retinoic Acid/genetics , Receptors, Retinoic Acid/metabolism , Recovery of Function , Response Elements , Retinoic Acid Receptor alpha , Signal Transduction , Time Factors , Transcriptional Activation , Transfection , Up-Regulation
20.
Environ Toxicol Pharmacol ; 31(1): 153-9, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21787680

ABSTRACT

Since hypoxia-inducible factor-1α (HIF-1α) is the key transcription factor that enables cells to survive in hypoxia, we have investigated whether an upregulation of HIF-1α prevents the noise-induced hearing loss in BALB/c hybrid mice, which were intraperitoneally injected with CoCl(2) (a HIF-1α inducer) and exposed to white band noise with 120 dB peak equivalent sound pressure level for 3h once daily for 3 days. In the CoCl(2) treatment group, HIF-1α was found to be up-regulated in the cochlear tissues and the hearing loss was largely prevented. Histologically, the loss of sensory hair cells was also significantly lower in the CoCl(2) treatment group than the Control group. However, YC-1 (a HIF-1α inhibitor) attenuated the preventive effect of CoCl(2) on the noise-induced hearing loss. These results suggest that HIF-1α plays a crucial role in the prevention against noise trauma in the inner ear.


Subject(s)
Cobalt/pharmacology , Hearing Loss, Noise-Induced/prevention & control , Hypoxia-Inducible Factor 1, alpha Subunit/biosynthesis , Animals , Auditory Threshold/drug effects , Auditory Threshold/physiology , Blotting, Western , Cell Survival/drug effects , Cochlea/drug effects , Cochlea/metabolism , Environmental Exposure , Enzyme Inhibitors/pharmacology , Evoked Potentials, Auditory/drug effects , Guanylate Cyclase/antagonists & inhibitors , Hair Cells, Auditory/drug effects , Hair Cells, Auditory/pathology , Hearing/drug effects , Hearing Loss, Noise-Induced/pathology , Hearing Loss, Noise-Induced/psychology , Hypoxia-Inducible Factor 1, alpha Subunit/antagonists & inhibitors , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Indazoles/pharmacology , Mice , Mice, Inbred BALB C , Noise/adverse effects
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