74 research outputs found
Muscle-specific deletion of SOCS3 increases the early inflammatory response but does not affect regeneration after myotoxic injury
Myosin heavy chain gene expression and muscle fiber oxidative capacity in muscles from uninjured control and SOCS3 MKO mice. qRT-PCR using primers to detect MyHCIIb (A), MyHCIIx (B), MyHCI (C), and MyHCIIa (D) was performed on RNA extracted from snap frozen muscles following dissection. Data are expressed as meanâ±âSEM and compared with an unpaired two-tailed Studentâs t test. nâ=â8 mice/genotype. (E) Representative succinate dehydrogenase (SDH)-reacted TA muscle sections from uninjured muscles of 12-week-old control and SOCS3 MKO mice. Quantification of SDH intensity was determined by analysis of SDH reacted TA muscle sections. Data are expressed as meanâ±âSEM and compared with an unpaired two-tailed Studentâs t test. nâ=â5 mice/genotype. Scale barâ=â100 Όm. (PDF 145 kb
Constitutive Gs activation using a single-construct tetracycline-inducible expression system in embryonic stem cells and mice
Abstract Introduction The controlled expression of many genes, including G-protein coupled receptors (GPCRs), is important for delineating gene functions in complex model systems. Binary systems for inducible regulation of transgene expression are widely used in mice. One system is the tTA/TRE expression system, composed of a tetracycline-dependent DNA binding factor and a separate tetracycline operon. However, the requirement for two separate transgenes (one for each tTA or TRE component) makes this system less amenable to models requiring directed cell targeting, increases the risk of multiple transgene integration sites, and requires extensive screening for appropriately-functioning clones. Methods We developed a single, polycistronic tetracycline-inducible expression platform to control the expression of multiple cistrons in mammalian cells. This platform has three basic constructs: regulator, responder, and destination vectors. The modular platform is compatible with both the TetOff (tTA) and TetOn (rtTA) systems. The modular Gateway recombineering-compatible components facilitate rapidly generating vectors to genetically modify mammalian cells. We apply this system to use the elongation factor 1α (EF1α) promoter to drive doxycycline-regulated expression of both the fluorescent marker mCherry and an engineered Gs-coupled GPCR "Rs1" separated by a 2A ribosomal skip site. Results We show that our combined expression construct drives expression of both the mCherry and Rs1 transgenes in a doxycycline-dependent manner. We successfully target the expression construct into the Rosa26 locus of mouse embryonic stem (ES) cells. Rs1 expression in mouse ES cells increases cAMP accumulation via both basal and ligand-induced Gs mechanisms and is associated with increased embryoid body size. Heterozygous mice carrying the Rs1 expression construct showed normal growth and weight, and developed small increases in bone formation that could be observed in the calvaria. Conclusions Our results demonstrate the feasibility of a single-vector strategy that combines both the tTA and TRE tetracycline-regulated components for use in cells and mouse models. Although the EF1α promoter is useful for driving expression in pluripotent cells, a single copy of the EF1α promoter did not drive high levels of mCherry and Rs1 expression in the differentiated tissues of adult mice. These findings indicate that promoter selection is an important factor when developing transgene expression models
Population Pharmacokinetics and Pharmacodynamics of Itraconazole for Disseminated Infection Caused by Talaromyces marneffei.
First-line treatment of talaromycosis with amphotericin B deoxycholate (DAmB) is labor-intensive and toxic. Itraconazole is an appealing alternative antifungal agent. Pharmacokinetic data were obtained from 76 patients who were randomized to itraconazole in the Itraconazole versus Amphotericin B for Talaromycosis (IVAP) trial. Plasma levels of itraconazole and its active metabolite, hydroxyitraconazole, were analyzed alongside longitudinal fungal CFU counts in a population model. Itraconazole and hydroxyitraconazole pharmacokinetic variability was considerable, with areas under the concentration-time curve over 24âh (AUC24) of 3.34â±â4.31âmg·h/liter and 3.57â±â4.46âmg·h/liter (mean ± standard deviation), respectively. Levels of both analytes were low; itraconazole minimum concentration (Cmin) was 0.11â±â0.16âmg/liter, and hydroxyitraconazole Cmin was 0.13â±â0.17âmg/liter. The mean maximal rates of drug-induced killing were 0.206 and 0.208 log10 CFU/ml/h, respectively. There were no associations between itraconazole Cmin/MIC and time to sterilization of the bloodstream (hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.99 to 1.03; Pâ=â0.43), time to death (HR, 0.99; 95% CI, 0.96 to 1.02; Pâ=â0.77), or early fungicidal activity (EFA) (coefficient, -0.004; 95% CI, -0.010 to 0.002; Pâ=â0.18). Similarly, there was no relationship between AUC/MIC and time to sterilization of the bloodstream (HR, 1.00; 95% CI, 0.99 to 1.00; Pâ=â0.50), time to death (HR, 1.00; 95% CI, 0.99 to 1.00; Pâ=â0.91), or EFA (coefficient, -0.0001; 95% CI, -0.0003 to 0.0001; Pâ=â0.19). This study raises the possibility that the failure of itraconazole to satisfy noninferiority criteria against DAmB for talaromycosis in the IVAP trial was a pharmacokinetic and pharmacodynamic failure
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Assessing the virulence of Cryptococcus neoformans causing meningitis in HIV infected and uninfected patients in Vietnam.
We previously observed a substantial burden of cryptococcal meningitis in Vietnam atypically arising in individuals who are uninfected with human immunodeficiency virus (HIV). This disease was associated with a single genotype of Cryptococcus neoformans (sequence type [ST]5), which was significantly less common in HIV-infected individuals. Aiming to compare the phenotypic characteristics of ST5 and non-ST5 C. neoformans, we selected 30 representative Vietnamese isolates and compared their in vitro pathogenic potential and in vivo virulence. ST5 and non-ST5 organisms exhibited comparable characteristics with respect to in vitro virulence markers including melanin production, replication at 37°C, and growth in cerebrospinal fluid. However, the ST5 isolates had significantly increased variability in cellular and capsular sizing compared with non-ST5 organisms (P < .001). Counterintuitively, mice infected with ST5 isolates had significantly longer survival with lower fungal burdens at day 7 than non-ST5 isolates. Notably, ST5 isolates induced significantly greater initial inflammatory responses than non-ST5 strains, measured by TNF-α concentrations (P < .001). Despite being generally less virulent in the mouse model, we hypothesize that the significant within strain variation seen in ST5 isolates in the tested phenotypes may represent an evolutionary advantage enabling adaptation to novel niches including apparently immunocompetent human hosts
Modifying Ligand-Induced and Constitutive Signaling of the Human 5-HT4 Receptor
G proteinâcoupled receptors (GPCRs) signal through a limited number of G-protein pathways and play crucial roles in many biological processes. Studies of their in vivo functions have been hampered by the molecular and functional diversity of GPCRs and the paucity of ligands with specific signaling effects. To better compare the effects of activating different G-protein signaling pathways through ligand-induced or constitutive signaling, we developed a new series of RASSLs (receptors activated solely by synthetic ligands) that activate different G-protein signaling pathways. These RASSLs are based on the human 5-HT4b receptor, a GPCR with high constitutive Gs signaling and strong ligand-induced G-protein activation of the Gs and Gs/q pathways. The first receptor in this series, 5-HT4-D100A or Rs1 (RASSL serotonin 1), is not activated by its endogenous agonist, serotonin, but is selectively activated by the small synthetic molecules GR113808, GR125487, and RO110-0235. All agonists potently induced Gs signaling, but only a few (e.g., zacopride) also induced signaling via the Gq pathway. Zacopride-induced Gq signaling was enhanced by replacing the C-terminus of Rs1 with the C-terminus of the human 5-HT2C receptor. Additional point mutations (D66A and D66N) blocked constitutive Gs signaling and lowered ligand-induced Gq signaling. Replacing the third intracellular loop of Rs1 with that of human 5-HT1A conferred ligand-mediated Gi signaling. This Gi-coupled RASSL, Rs1.3, exhibited no measurable signaling to the Gs or Gq pathway. These findings show that the signaling repertoire of Rs1 can be expanded and controlled by receptor engineering and drug selection
The global response: How cities and provinces around the globe tackled Covid-19 outbreaks in 2021
Background: Tackling the spread of COVID-19 remains a crucial part of ending the pandemic. Its highly contagious nature and constant evolution coupled with a relative lack of immunity make the virus difficult to control. For this, various strategies have been proposed and adopted including limiting contact, social isolation, vaccination, contact tracing, etc. However, given the heterogeneity in the enforcement of these strategies and constant fluctuations in the strictness levels of these strategies, it becomes challenging to assess the true impact of these strategies in controlling the spread of COVID-19.Methods: In the present study, we evaluated various transmission control measures that were imposed in 10 global urban cities and provinces in 2021 Bangkok, Gauteng, Ho Chi Minh City, Jakarta, London, Manila City, New Delhi, New York City, Singapore, and Tokyo.Findings: Based on our analysis, we herein propose the population-level Swiss cheese model for the failures and pit-falls in various strategies that each of these cities and provinces had. Furthermore, whilst all the evaluated cities and provinces took a different personalized approach to managing the pandemic, what remained common was dynamic enforcement and monitoring of breaches of each barrier of protection. The measures taken to reinforce the barriers were adjusted continuously based on the evolving epidemiological situation.Interpretation: How an individual city or province handled the pandemic profoundly affected and determined how the entire country handled the pandemic since the chain of transmission needs to be broken at the very grassroot level to achieve nationwide control
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Food and Power in Roald Dahl\u27s Children\u27s Fiction
Food and Power in Roald Dahl\u27s Children\u27s Fiction
Jennifer Trieu
Trinity College Dublin
2017
Abstract
This thesis examines the representation of food and power in Roald Dahl?s children?s fiction written between the years 1961 and 1990. This thesis explores how the relationship between food and power in Dahl?s biographical and literary works provides valuable insight into the author?s often contradictory messages about food and ?proper? consumption. In this dissertation, I trace how Dahl?s lifelong fascination with food and food issues have shaped the power relationships, power dynamics, and power reversals represented in his children?s works. Food is indeed central to important discussions about power and control in his oeuvre: the fantastical confectionery in Charlie and the Chocolate Factory (1964), the gigantic peach in James and the Giant Peach (1961), and Mr Twit?s food-filled beard in The Twits (1980) are just a few examples that are part of important discussions about consumer power, power and the natural world, and self-control, respectively. In a similar vein, the power dynamics between animals and humans in The Magic Finger (1966), and Fantastic Mr Fox (1970), and adults and children in Matilda (1988), are effectively understood through the representations of food in these novels. Throughout Dahl?s children?s fiction, ideas about pleasure and restraint are deeply connected to discussions about food?s position in the minutiae of everyday life in twentieth-century British society. Particular emphasis is placed on industrialised and processed food in Dahl?s novels and this study focuses on four key foodstuffs predominantly represented in his works: meat, sweets, convenience foods, and futuristic foods. This thesis endeavours to uncover new areas of study on Dahl?s major and lesser-known children?s works, and offers suggestions for future critical work on the author
Risk factors of female breast cancer in Vietnam: a case-control study
Purpose: Rates of women with breast cancer have increased rapidly in recent years in Vietnam, with over 10,000 new patients contracting the disease every year. This study was conducted to identify demographic, reproductive and lifestyle risk factors for breast cancer in Vietnam. Materials and Methods: Breast density, demographic, reproductive and lifestyle data of 269 women with breast cancer and 519 age-matched controls were collected in the two largest oncology hospitals in Vietnam (one in the north and one in the south). Baseline differences between cases and controls in all women, premenopausal and postmenopausal women were assessed using chi-squared tests and independent t tests. Conditional logistic regression was used to derive odds ratios (OR) for factors that had statistically significant associations with breast cancer. Results: Vietnamese women with breast cancer were significantly more likely to have a breast density > 75% (OR, 1.7), be younger than 14 years at first menstrual period (OR, 2.2), be postmenopausal (OR, 2.0), have less than three pregnancies (OR, 2.1), and have less than two babies (OR, 1.7). High breast density (OR, 1.6), early age at first menstrual period (OR, 2.6), low number of pregnancies (OR, 2.3), hormone use (OR, 1.8), and no physical activities (OR, 2.2) were significantly associated with breast cancer among premenopausal women, while breast density (OR, 2.0), age at first menstrual period (OR, 1.8), number of pregnancies (OR, 2.3), and number of live births (OR, 2.4) were the risk factors for postmenopausal women. Conclusion: Breast density, age at first menarche, menopause status, number of pregnancies, number of babies born, hormone use and physical activities were significantly associated with breast cancer in Vietnamese women
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