Function and anatomy of plant siRNA pools derived from hairpin transgenes

<p>Abstract</p> <p>Background</p> <p>RNA interference results in specific gene silencing by small-interfering RNAs (siRNAs). Synthetic siRNAs provide a powerful tool for manipulating gene expression but high cost suggests that novel siRNA production methods are desirable. Strong evolutionary conservation of siRNA structure suggested that siRNAs will retain cross-species function and that transgenic plants expressing heterologous siRNAs might serve as useful siRNA bioreactors. Here we report a detailed evaluation of the above proposition and present evidence regarding structural features of siRNAs extracted from plants.</p> <p>Results</p> <p>Testing the gene silencing capacity of plant-derived siRNAs in mammalian cells proved to be very challenging and required partial siRNA purification and design of a highly sensitive assay. Using the above assay we found that plant-derived siRNAs are ineffective for gene silencing in mammalian cells. Plant-derived siRNAs are almost exclusively double-stranded and most likely comprise a mixture of bona fide siRNAs and aberrant partially complementary duplexes. We also provide indirect evidence that plant-derived siRNAs may contain a hitherto undetected physiological modification, distinct from 3' terminal 2-O-methylation.</p> <p>Conclusion</p> <p>siRNAs produced from plant hairpin transgenes and extracted from plants are ineffective for gene silencing in mammalian cells. Thus our findings establish that a previous claim that transgenic plants offer a cost-effective, scalable and sustainable source of siRNAs is unwarranted. Our results also indicate that the presence of aberrant siRNA duplexes and possibly a plant-specific siRNA modification, compromises the gene silencing capacity of plant-derived siRNAs in mammalian cells.</p

Mild iodine deficiency and thyroid disorders in Hong Kong.

OBJECTIVES: To review evidence of iodine deficiency and clinical thyroid disorders in Hong Kong. DATA SOURCES: Publications on local dietary iodine intake, the iodine content of local food items, and clinical thyroid problems in the Hong Kong population. DATA EXTRACTION: Data was extracted and evaluated independently by the authors. DATA SYNTHESIS: Iodine is an essential nutrient. Iodine deficiency can lead to goitre, hypothyroidism, mental deficiency, and impaired growth. It is now appreciated that determination of goitre incidence in children alone may grossly underestimate the problem of iodine deficiency in a population. In total, the evidence indicates that iodine deficiency exists in Hong Kong, leading to clinical problems of transient neonatal hypothyroidism, goitrogenesis, and thyroid disorders in pregnant women and neonates, as well as thyroid dysfunction in the elderly. CONCLUSION: A supplementation programme aimed at a relatively uniform iodine intake is recommended to avoid deficient or excessive iodine intake in subpopulations.published_or_final_versio

De invloed van de temperatuur tijdens de opkweekperiode op de positie van de 1e tros, bij verschillende rassen van tomaat, 1961-1962

<p><b>Copyright information:</b></p><p>Taken from "Function and anatomy of plant siRNA pools derived from hairpin transgenes"</p><p>http://www.plantmethods.com/content/3/1/13</p><p>Plant Methods 2007;3():13-13.</p><p>Published online 25 Nov 2007</p><p>PMCID:PMC2217544.</p><p></p> mC9 sense and anti-sense sequences separated by the TGA1 intron (I) with expression by the CMV 35S promoter (35S) and NOS terminator. Transgene integrity for plants Tc9 #1, 3, 5, 9, 11, 13 was verified via PCR (primer position indicated by black arrows) to detect sense (s) and anti-sense (as) transgene elements. Endogenous rbcL is control. For siRNA expression 30 μg of total RNA from wt tobacco or Tc9 transformants was analysed by Northern blotting. A 31 nt mC9 DNA oligo (m) is size marker and an overnight phosphor-image is shown. In vivo gene silencing in Tc9 transformants. Transient transformation was performed by co-infiltration of tobacco wt, Tc9 #1 and #3 with plasmids expressing mC9 sense (pBmC9s) and EYFP transcripts (pBEYFP). Transcript levels in leaf regions were analysed 48 hr post-infiltration by Northern blotting (as described in materials and methods)

The potential use of honey as a remedy for allergic diseases: a mini review

Honey has been conventionally consumed as food. However, its therapeutic properties have also gained much attention due to its application as a traditional medicine. Therapeutic properties of honey such as anti-microbial, anti-inflammatory, anti-cancer and wound healing have been widely reported. A number of interesting studies have reported the potential use of honey in the management of allergic diseases. Allergic diseases including anaphylaxis, asthma and atopic dermatitis (AD) are threatening around 20% of the world population. Although allergic reactions are somehow controllable with different drugs such as antihistamines, corticosteroids and mast cell stabilizers, modern dietary changes linked with allergic diseases have prompted studies to assess the preventive and therapeutic merits of dietary nutrients including honey. Many scientific evidences have shown that honey is able to relieve the pathological status and regulate the recruitment of inflammatory cells in cellular and animal models of allergic diseases. Clinically, a few studies demonstrated alleviation of allergic symptoms in patients after application or consumption of honey. Therefore, the objective of this mini review is to discuss the effectiveness of honey as a treatment or preventive approach for various allergic diseases. This mini review will provide insights into the potential use of honey in the management of allergic diseases in clinical settings

Neuroinflammation and structural injury of the fetal ovine brain following intra-amniotic Candida albicans exposure.

BackgroundIntra-amniotic Candida albicans (C. Albicans) infection is associated with preterm birth and high morbidity and mortality rates. Survivors are prone to adverse neurodevelopmental outcomes. The mechanisms leading to these adverse neonatal brain outcomes remain largely unknown. To better understand the mechanisms underlying C. albicans-induced fetal brain injury, we studied immunological responses and structural changes of the fetal brain in a well-established translational ovine model of intra-amniotic C. albicans infection. In addition, we tested whether these potential adverse outcomes of the fetal brain were improved in utero by antifungal treatment with fluconazole.MethodsPregnant ewes received an intra-amniotic injection of 10(7) colony-forming units C. albicans or saline (controls) at 3 or 5 days before preterm delivery at 0.8 of gestation (term ~ 150 days). Fetal intra-amniotic/intra-peritoneal injections of fluconazole or saline (controls) were administered 2 days after C. albicans exposure. Post mortem analyses for fungal burden, peripheral immune activation, neuroinflammation, and white matter/neuronal injury were performed to determine the effects of intra-amniotic C. albicans and fluconazole treatment.ResultsIntra-amniotic exposure to C. albicans caused a severe systemic inflammatory response, illustrated by a robust increase of plasma interleukin-6 concentrations. Cerebrospinal fluid cultures were positive for C. albicans in the majority of the 3-day C. albicans-exposed animals whereas no positive cultures were present in the 5-day C. albicans-exposed and fluconazole-treated animals. Although C. albicans was not detected in the brain parenchyma, a neuroinflammatory response in the hippocampus and white matter was seen which was characterized by increased microglial and astrocyte activation. These neuroinflammatory changes were accompanied by structural white matter injury. Intra-amniotic fluconazole reduced fetal mortality but did not attenuate neuroinflammation and white matter injury.ConclusionsIntra-amniotic C. albicans exposure provoked acute systemic and neuroinflammatory responses with concomitant white matter injury. Fluconazole treatment prevented systemic inflammation without attenuating cerebral inflammation and injury

Comparison of Several Methods of Chromatographic Baseline Removal with a New Approach Based on Quantile Regression

The article is intended to introduce and discuss a new quantile regression method for baseline detrending of chromatographic signals. It is compared with current methods based on polynomial fitting, spline fitting, LOESS, and Whittaker smoother, each with thresholding and reweighting approach. For curve flexibility selection in existing algorithms, a new method based on skewness of the residuals is successfully applied. The computational efficiency of all approaches is also discussed. The newly introduced methods could be preferred to visible better performance and short computational time. The other algorithms behave in comparable way, and polynomial regression can be here preferred due to short computational time

HURP Expression-Assisted Risk Scores Identify Prognosis Distinguishable Subgroups in Early Stage Liver Cancer

Hepatoma up-regulated protein (HURP) is a component of the chromatin-dependent pathway for spindle assembly. We examined the prognostic predictive value of HURP in human hepatocellular carcinoma (HCC).HURP expression was evaluated by immunocytochemistry of fine needle aspirated hepatoma cells in 97 HCC patients with Barcelona Clinic Liver Cancer (BCLC) stage A. Subsequently, these patients underwent partial hepatectomy (n = 18) or radiofrequency ablation (n = 79) and were followed for 2 to 35 months. The clinicopathological parameters were submitted for survival analysis.HURP expression in aspirated HCC cells was detected in 19.6% patients. Kaplan-Meier survival analysis showed that positive HURP expression (P = 0.023), cytological grading ≥3 (P = 0.008), AFP ≥35 ng/mL (P = 0.039), bilirubin ≥1.3 mg/dL (P = 0.010), AST ≥50 U/L (P = 0.003) and ALT ≥35 U/L (P = 0.005) were all associated with a shorter disease-free survival. A stepwise multivariate Cox proportional hazard model revealed that positive HURP expression (HR, 2.334; 95% CI, 1.165-4.679, P = 0.017), AST ≥50 U/L (HR, 3.697; 95% CI, 1.868-7.319, p<0.001), cytological grade ≥3 (HR, 4.249; 95% CI, 2.061-8.759, P<0.001) and tumor number >1 (HR, 2.633; 95% CI, 1.212-5.722, P = 0.014) were independent predictors for disease-free survival. By combining the 4 independent predictors, patients with different risk scores (RS) showed distinguishable disease-free survival (RS≤1 vs. RS = 2, P = 0.001; RS = 2 vs. RS = 3, P<0.001). In contrast, the patients cannot be separated into prognosis distinguishable subgroups by using AJCC/UICC TNM staging system.HCC patients with BCLC stage A can be separated into three prognosis-distinguishable groups by use of a risk score that is based upon HURP expression in aspirated HCC cells, ALT, cytological grade and tumor number

A Dual Function for Prickle in Regulating Frizzled Stability during Feedback-Dependent Amplification of Planar Polarity

The core planar polarity pathway coordinates epithelial cell polarity during animal development, and loss of its activity gives rise to a range of defects, from aberrant morphogenetic cell movements to failure to correctly orient structures, such as hairs and cilia. The core pathway functions via a mechanism involving segregation of its protein components to opposite cells ends, where they form asymmetric intracellular complexes that couple cell-cell polarity. This segregation is a self-organizing process driven by feedback interactions between the core proteins themselves. Despite intense efforts, the molecular pathways underlying feedback have proven difficult to elucidate using conventional genetic approaches. Here we investigate core protein function during planar polarization of the Drosophila wing by combining quantitative measurements of protein dynamics with loss-of-function genetics, mosaic analysis, and temporal control of gene expression. Focusing on the key core protein Frizzled, we show that its stable junctional localization is promoted by the core proteins Strabismus, Dishevelled, Prickle, and Diego. In particular, we show that the stabilizing function of Prickle on Frizzled requires Prickle activity in neighboring cells. Conversely, Prickle in the same cell has a destabilizing effect on Frizzled. This destabilizing activity is dependent on the presence of Dishevelled and blocked in the absence of Dynamin and Rab5 activity, suggesting an endocytic mechanism. Overall, our approach reveals for the first time essential in vivo stabilizing and destabilizing interactions of the core proteins required for self-organization of planar polarity

Pulmonary Embolism Incidence and Fatality Trends in Chinese Hospitals from 1997 to 2008: A Multicenter Registration Study

BACKGROUND: There has not been sufficient evidence to support the Asians being less susceptible to pulmonary embolism (PE) than other ethnicities, because the prevalence of PE/deep venous thrombosis (DVT) in different racial and ethnic groups has not been carefully studied until recently except in Caucasians. To test the hypothesis that the Chinese population has a lower risk for PE, this study comprehensively assessed the hospital-based incidence and case fatality rates for PE during the 1997-2008 in China. METHODS: A registration study of patients with suspected PE syndromes admitted to 60 level-3 hospitals involved in the National Cooperative Project for the Prevention and Treatment of Venous Thromboembolism (NCPPT) was conducted from January 1997 to December 2008. The only exclusion criterion was an age of less than 18 years. Helical computed tomography scan, ventilation-perfusion lung scintigraphy or pulmonary angiography was carried out before or after hospitalization. All images were reviewed and evaluated independently by two specialists. RESULTS: A total of 18,206 patients were confirmed with PE from 16,972,182 hospital admissions. The annual incidence was 0.1% (95% CI: 0.1% to 0.2%). The overall incidence of PE in male patients (0.2%, 95% CI: 0.1% to 0.3%) was higher than that in female patients (0.1% and 95% CI: 0.0% to 0.1%). An increasing incidence gradient for PE was noticed from Southern to Northern China. In addition, the case fatality rate was apparently decreasing: 25.1% (95% CI: 16.2% to 36.9%) in 1997 to 8.7% (95% CI: 3.5% to 15.8%) in 2008. CONCLUSIONS: Our findings suggest the relatively stable PE incidence and decreasing fatality trends in Chinese hospitals may be partially attributable to the implementation of the NCCPT and suggest the government should reevaluate the severity of PE so that health resources for the prevention, diagnosis and treatment of PE could be used to their fullest