315 research outputs found

    Genetic screen for factors mediating PIN polarization in gravistimulated Arabidopsis thaliana hypocotyls

    Get PDF
    Gravitropism is an adaptive response that orients plant growth parallel to the gravity vector. Asymmetric distribution of the phytohormone auxin is a necessary prerequisite to the tropic bending both in roots and shoots. During hypocotyl gravitropic response, the PIN3 auxin transporter polarizes within gravity-sensing cells to redirect intercellular auxin fluxes. First gravity-induced PIN3 polarization to the bottom cell mem- branes leads to the auxin accumulation at the lower side of the organ, initiating bending and, later, auxin feedback-mediated repolarization restores symmetric auxin distribution to terminate bending. Here, we per- formed a forward genetic screen to identify regulators of both PIN3 polarization events during gravitropic response. We searched for mutants with defective PIN3 polarizations based on easy-to-score morphological outputs of decreased or increased gravity-induced hypocotyl bending. We identified the number of hypocotyl reduced bending (hrb) and hypocotyl hyperbending (hhb) mutants, revealing that reduced bending corre- lated typically with defective gravity-induced PIN3 relocation whereas all analyzed hhb mutants showed defects in the second, auxin-mediated PIN3 relocation. Next-generation sequencing-aided mutation map- ping identified several candidate genes, including SCARECROW and ACTIN2, revealing roles of endodermis specification and actin cytoskeleton in the respective gravity- and auxin-induced PIN polarization events. The hypocotyl gravitropism screen thus promises to provide novel insights into mechanisms underlying cell polarity and plant adaptive development

    TAZ Suppresses NFAT5 Activity through Tyrosine Phosphorylation

    Get PDF
    Transcriptional coactivator with PDZ-binding motif (TAZ) physically interacts with a variety of transcription factors and modulates their activities involved in cell proliferation and mesenchymal stem cell differentiation. TAZ is highly expressed in the kidney, and a deficiency of this protein results in multiple renal cysts and urinary concentration defects; however, the molecular functions of TAZ in renal cells remain largely unknown. In this study, we examined the effects of osmotic stress on TAZ expression and activity in renal cells. We found that hyperosmotic stress selectively increased protein phosphorylation at tyrosine 316 of TAZ and that this was enhanced by c-Abl activation in response to hyperosmotic stress. Interestingly, phosphorylated TAZ physically interacted with nuclear factor of activated T cells 5 (NFAT5), a major osmoregulatory transcription factor, and subsequently suppressed DNA binding and transcriptional activity of NFAT5. Furthermore, TAZ deficiency elicited an increase in NFAT5 activity in vitro and in vivo, which then reverted to basal levels following restoration of wild-type TAZ but not mutant TAZ (Y316F). Collectively, the data suggest that TAZ modulates cellular responses to hyperosmotic stress through fine-tuning of NFAT5 activity via tyrosine phosphorylation.open3

    Long-term culture captures injury-repair cycles of colonic stem cells

    Get PDF
    The colonic epithelium can undergo multiple rounds of damage and repair, often in response to excessive inflammation. The responsive stem cell that mediates this process is unclear, in part because of a lack of in vitro models that recapitulate key epithelial changes that occur in vivo during damage and repair. Here, we identify a Hop

    Continuing to Confront COPD International Physician Survey: Physician Knowledge and Application of COPD Management Guidelines in 12 Countries

    Get PDF
    AIM: Utilizing data from the Continuing to Confront COPD (chronic obstructive pulmonary disease) International Physician Survey, this study aimed to describe physicians\u27 knowledge and application of the GOLD (Global initiative for chronic Obstructive Lung Disease) Global Strategy for the Diagnosis, Management and Prevention of COPD diagnosis and treatment recommendations and compare performance between primary care physicians (PCPs) and respiratory specialists. MATERIALS AND METHODS: Physicians from 12 countries were sampled from in-country professional databases; 1,307 physicians (PCP to respiratory specialist ratio three to one) who regularly consult with COPD, emphysema, or chronic bronchitis patients were interviewed online, by telephone or face to face. Physicians were questioned about COPD risk factors, prognosis, diagnosis, and treatment, including knowledge and application of the GOLD global strategy using patient scenarios. RESULTS:Physicians reported using spirometry routinely (PCPs 82%, respiratory specialists 100%; P\u3c0.001) to diagnose COPD and frequently included validated patient-reported outcome measures (PCPs 67%, respiratory specialists 81%; P\u3c0.001). Respiratory specialists were more likely than PCPs to report awareness of the GOLD global strategy (93% versus 58%, P\u3c0.001); however, when presented with patient scenarios, they did not always perform better than PCPs with regard to recommending GOLD-concordant treatment options. The proportion of PCPs and respiratory specialists providing first- or second-choice treatment options concordant with GOLD strategy for a GOLD B-type patient was 38% versus 67%, respectively. For GOLD C and D-type patients, the concordant proportions for PCPs and respiratory specialists were 40% versus 38%, and 57% versus 58%, respectively. CONCLUSION: This survey of physicians in 12 countries practicing in the primary care and respiratory specialty settings showed high awareness of COPD-management guidelines. Frequent use of guideline-recommended COPD diagnostic practices was reported; however, gaps in the application of COPD-treatment recommendations were observed, warranting further evaluation to understand potential barriers to adopt guideline recommendations

    Health Behaviors and Their Correlates Among Participants in the Continuing to Confront COPD International Patient Survey

    Get PDF
    Background and aims: We used data from the Continuing to Confront COPD International Patient Survey to test the hypothesis that patients with COPD who report less engagement with their disease management are also more likely to report greater impact of the disease. Methods: This was a population-based, cross-sectional survey of 4,343 subjects aged ≥ 40 years from 12 countries, fulfilling a case definition of COPD based on self-reported physician diagnosis or symptomatology. The impact of COPD was measured with COPD Assessment Test, modified Medical Research Council Dyspnea Scale, and hospital admissions and emergency department visits for COPD in the prior year. The 13-item Patient Activation Measure (PAM-13) instrument and the 8-item Morisky Medication Adherence Scale (MMAS-8) were used to measure patient disease engagement and medication adherence, respectively. Results: Twenty-eight percent of subjects reported being either disengaged or struggling with their disease (low engagement: PAM-13 levels 1 and 2), and 35% reported poor adherence (MMAS-8 \u3c 6). In univariate analyses, lower PAM-13 and MMAS-8 scores were significantly associated with poorer COPD-specific health status, greater breathlessness and lower BMI (PAM-13 only), less satisfaction with their doctor’s management of COPD, and more emergency department visits. In multivariate regression models, poor satisfaction with their doctor’s management of COPD was significantly associated with both low PAM-13 and MMAS-8 scores; low PAM-13 scores were additionally independently associated with higher COPD Assessment Test and modified Medical Research Council scores and low BMI (underweight). Conclusion: Poor patient engagement and medication adherence are frequent and associated with worse COPD-specific health status, higher health care utilization, and lower satisfaction with health care providers. More research will be needed to better understand what factors can be modified to improve medication adherence and patient engagement

    Two cases of telbivudine-induced myopathy in siblings with chronic hepatitis B

    Get PDF
    Telbivudine is an L-nucleoside analogue with potent antiviral activity against hepatitis B virus (HBV). Clinical trials have shown that telbivudine has a more potent and sustained antiviral activity with a lower frequency of viral resistance than lamivudine. Although there are several reports concerning the safety profile of telbivudine, most adverse events are described as mild and transient in nature. Here we report two cases of telbivudine-induced myopathy in patients with chronic hepatitis B who were siblings

    Occupational asthma as a differential diagnosis of adult-onset asthma – a case report

    Get PDF
    Bronchial asthma causes great morbidity and mortality worldwide. Certain occupations especially those exposed to known triggers of asthma such as animal fur, dusts or solvents may trigger asthma attacks in a previously undiagnosed individual or worsen its’ control in a known asthmatic. This is especially true for adult-onset asthma. This may in turn the health of the affected workers and affect their productivity. Affected workers may be given job reassignment and eligible for medical compensation from Social Security Organisation (SOSCO). This case report will look at how two individuals in very distinct occupation were diagnosed with suspected occupational asthma

    Exposures to Air Pollutants during Pregnancy and Preterm Delivery

    Get PDF
    The association between preterm delivery (PTD) and exposure to air pollutants has recently become a major concern. We investigated this relationship in Incheon, Republic of Korea, using spatial and temporal modeling to better infer individual exposures. The birth cohort consisted of 52,113 singleton births in 2001–2002, and data included residential address, gestational age, sex, birth date and order, and parental age and education. We used a geographic information system and kriging methods to construct spatial and temporal exposure models. Associations between exposure and PTD were evaluated using univariate and multivariate log-binomial regressions. Given the gestational age, birth date, and the mother’s residential address, we estimated each mother’s potential exposure to air pollutants during critical periods of the pregnancy. The adjusted risk ratios for PTD in the highest quartiles of the first trimester exposure were 1.26 [95% confidence interval (CI), 1.11–1.44] for carbon monoxide, 1.27 (95% CI, 1.04–1.56) for particulate matter with aerodynamic diameter ≤ 10 μm, 1.24 (95% CI, 1.09–1.41) for nitrogen dioxide, and 1.21 (95% CI, 1.04–1.42) for sulfur dioxide. The relationships between PTD and exposures to CO, NO(2), and SO(2) were dose dependent (p < 0.001, p < 0.02, p < 0.02, respectively). In addition, the results of our study indicated a significant association between air pollution and PTD during the third trimester of pregnancy. In conclusion, our study showed that relatively low concentrations of air pollution under current air quality standards during pregnancy may contribute to an increased risk of PTD. A biologic mechanism through increased prostaglandin levels that are triggered by inflammatory mediators during exposure periods is discussed

    Genetic and antigenic characterization of influenza A/H5N1 viruses isolated from patients in Indonesia, 2008–2015

    Get PDF
    Since the initial detection in 2003, Indonesia has reported 200 human cases of highly pathogenic avian influenza H5N1 (HPAI H5N1), associated with an exceptionally high case fatality rate (84%) compared to other geographical regions affected by other genetic clades of the virus. However, there is limited information on the genetic diversity of HPAI H5N1 viruses, especially those isolated from humans in Indonesia. In this study, the genetic and antigenic characteristics of 35 HPAI H5N1 viruses isolated from humans were analyzed. Full genome sequences were analyzed for the presence of substitutions in the receptor binding site, and p
    corecore