26 research outputs found

    Enhanced astaxanthin production by oxidative stress using methyl viologen as a reactive oxygen species (ROS) reagent in green microalgae Coelastrum sp.

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    Microalgae are known to be a potential resource of high-value metabolites that can be used in the growing field of biotechnology. These metabolites constitute valuable compounds with a wide range of applications that strongly enhance a bio-based economy. Among these metabolites, astaxanthin is considered the most important secondary metabolite, having superior antioxidant properties. For commercial feasibility, microalgae with enhanced astaxanthin production need to be developed. In this study, the tropical green microalgae strain, Coelastrum sp., isolated from the environment in Malaysia, was incubated with methyl viologen, a reactive oxygen species (ROS) reagent that generates superoxide anion radicals (O2-) as an enhancer to improve the accumulation of astaxanthin. The effect of different concentrations of methyl viologen on astaxanthin accumulation was investigated. The results suggested that the supplementation of methyl viologen at low concentration (0.001 mM) was successfully used as a ROS reagent in facilitating and thereby increasing the production of astaxanthin in Coelastrum sp. at a rate 1.3 times higher than in the control

    Improvement of astaxanthin production in coelastrum sp. by optimization using taguchi method

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    Background and Objective: Astaxanthin is a keto-carotenoid pigment known as one of the most valuable compounds with great potentials in the market. It has widely been used in nutraceutical, pharmaceutical, cosmetics and food industries due to its strong antioxidant activity. Green microalgae seem as promising natural sources in production of astaxanthin. The aim of this study was to optimize astaxanthin production in Coelastrum sp. to overcome low productivity of microalgae. Materials and Methods: This study was carried out using experimentally statistical technique and Taguchi method to find optimum conditions for maximizing production of astaxanthin in green microalgae, Coelastrum sp. Effects of nutritional (carbon and nitrogen) and environmental (light and salinity) factors on biomass and astaxanthin production were investigated. Experiments were carried out for light intensity (250-550 μmol photons m-2 s-1), salinity using sodium chloride (1.0-3.0 g l-1), carbon source using sodium acetate (0.5-2.0 g l-1) and nitrogen source using sodium nitrate (0.1-0.3 g l-1). Results and Conclusion: Results showed that optimum conditions of astaxanthin production in Coelastrum sp. included 250 μmol photons m-2 s-1 of light intensity, 3 g l-1 salinity, 0.5 g l-1 carbon and 0.1 g l-1 nitrogen with a maximum yield of astaxanthin (14.44 mg l-1), which was 2-fold higher than that before optimization. This optimization resulted in high quantities of astaxanthin production using optimization of conditions that affected production yields of astaxanthin from Coelastrum sp

    Long-Term Persistent GBV-B Infection and Development of a Chronic and Progressive Hepatitis C-Like Disease in Marmosets

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    It has been shown that infection of GB virus B (GBV-B), which is closely related to hepatitis C virus, develops acute self-resolving hepatitis in tamarins. In this study we sought to examine longitudinally the dynamics of viral and immunological status following GBV-B infection of marmosets and tamarins. Surprisingly, two of four marmosets but not tamarins experimentally challenged with GBV-B developed long-term chronic infection with fluctuated viremia, recurrent increase of alanine aminotransferase and plateaued titers of the antiviral antibodies, which was comparable to chronic hepatitis C in humans. Moreover, one of the chronically infected marmosets developed an acute exacerbation of chronic hepatitis as revealed by biochemical, histological, and immunopathological analyses. Of note, periodical analyses of the viral genomes in these marmosets indicated frequent and selective non-synonymous mutations, suggesting efficient evasion of the virus from antiviral immune pressure. These results demonstrated for the first time that GBV-B could induce chronic hepatitis C-like disease in marmosets and that the outcome of the viral infection and disease progression may depend on the differences between species and individuals

    IRIS plus panitumumab for metastatic CRC

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    Background Irinotecan plus S-1 (IRIS) is the only oral fluoropyrimidine-based regimen reported to be non-inferior to FOLFIRI and widely used in clinical practice for metastatic colorectal cancer (mCRC) patients. However, the combination of IRIS plus an anti-EGFR agent has not been evaluated previously. This study aimed to investigate the feasibility and efficacy of IRIS with panitumumab as second-line therapy for wild-type KRAS mCRC. Methods Main inclusion criteria were patients with wild-type KRAS mCRC refractory to one prior chemotherapy regimen for mCRC, ECOG PS 0-2, and age ≥ 20 years. Patients received panitumumab (6mg/kg) and irinotecan (100mg/m2) on days 1 and 15 and S-1 (40-60 mg according to body surface area) twice daily for 2 weeks, repeated every 4 weeks. The primary endpoint was the feasibility of the therapy. The secondary endpoints were response rate (RR), progression-free survival (PFS), and overall survival (OS). Results A total of 36 patients received protocol treatment in eight centers. Of these, 23 patients (63.9%) completed protocol treatment, demonstrating achievement of the primary endpoint. The most frequent grade 3/4 toxicities were diarrhea (16.7%), acne-like rash (13.9%), and neutropenia (11.1%). The overall RR was 33.3% (12/36). Of these 4 five underwent conversion surgery. Median PFS and OS were 9.5 months (95% CI 3.5-15.4 months) and 20.1 months (95% CI 16.7-23.2 months), respectively. Conclusion IRIS plus panitumumab has an acceptable toxicity profile and a promising efficacy in patients with previously treated wild-type KRAS mCRC. Accordingly, this regimen can be an additional treatment option for second-line chemotherapy in wild-type KRAS mCRC

    Circular DNA Intermediate in the Duplication of Nile Tilapia vasa Genes

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    vasa is a highly conserved RNA helicase involved in animal germ cell development. Among vertebrate species, it is typically present as a single copy per genome. Here we report the isolation and sequencing of BAC clones for Nile tilapia vasa genes. Contrary to a previous report that Nile tilapia have a single copy of the vasa gene, we find evidence for at least three vasa gene loci. The vasa gene locus was duplicated from the original site and integrated into two distant novel sites. For one of these insertions we find evidence that the duplication was mediated by a circular DNA intermediate. This mechanism of gene duplication may explain the origin of isolated gene duplicates during the evolution of fish genomes. These data provide a foundation for studying the role of multiple vasa genes in the development of tilapia gonads, and will contribute to investigations of the molecular mechanisms of sex determination and evolution in cichlid fishes

    Future change of daily precipitation indices in Japan: a stochastic weather generator-based bootstrap approach to provide probabilistic climate information

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    This study proposes the stochastic weather generator (WG)-based bootstrap approach to provide the probabilistic climate change information on mean precipitation as well as extremes, which applies a WG (i.e., LARS-WG) to daily precipitation under the present-day and future climate conditions derived from dynamical and statistical downscaling models. Additionally, the study intercompares the precipitation change scenarios derived from the multimodel ensemble for Japan focusing on five precipitation indices (mean precipitation, MEA; number of wet days, FRE; mean precipitation amount per wet day, INT; maximum number of consecutive dry days, CDD; and 90th percentile value of daily precipitation amount in wet days, Q90). Three regional climate models (RCMs: NHRCM, NRAMS and TWRF) are nested into the high-resolution atmosphere-ocean coupled general circulation model (MIROC3.2HI AOGCM) for A1B emission scenario. LARS-WG is validated and used to generate 2000 years of daily precipitation from sets of grid-specific parameters derived from the 20-year simulations from the RCMs and statistical downscaling model (SDM: CDFDM). Then 100 samples of the 20-year of continuous precipitation series are resampled, and mean values of precipitation indices are computed, which represents the randomness inherent in daily precipitation data. Based on these samples, the probabilities of change in the indices and the joint occurrence probability of extremes (CDD and Q90) are computed. High probabilities are found for the increases in heavy precipitation amount in spring and summer and elongated consecutive dry days in winter over Japan in the period 2081-2100, relative to 1981-2000. The joint probability increases in most areas throughout the year, suggesting higher potential risk of droughts and excess water-related disasters (e. g., floods) in a 20 year period in the future. The proposed approach offers more flexible way in estimating probabilities of multiple types of precipitation extremes including their joint probability compared to conventional approaches

    Increased Red Blood Cell Distribution Width in the First Year after Diagnosis Predicts Worsening of Systemic Sclerosis-Associated Interstitial Lung Disease at 5 Years: A Pilot Study

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    The course of systemic sclerosis-associated interstitial lung disease (SSc-ILD) varies among individuals. Red blood cell distribution width (RDW) has been reported to be a predictor of idiopathic pulmonary fibrosis. However, there are no studies on the relationship between RDW and SSc-ILD. We conducted a retrospective study of 28 patients who were diagnosed with SSc-ILD on their first visit to our hospital and were followed-up for 5 years. The correlation between the changes in RDW, KL-6, and SP-D (ΔRDW, ΔKL-6, ΔSP-D) and the changes in percent-predicted forced lung volume and % carbon monoxide diffusion (Δ%FVC, Δ%DLco) was investigated. ΔRDW at 1 year after diagnosis was significantly inversely correlated with Δ%FVC at 5 years after diagnosis (r = −0.51, p < 0.001) and Δ%DLco at 5 years after diagnosis (r = −0.47, p < 0.001), whereas ΔKL-6 and ΔSP-D at 1 year were not correlated with Δ%FVC or Δ%DLco at 5 years. In the group of SSc-ILD patients with RDW increase in the first year after diagnosis, %FVC and %DLco were significantly lower than baseline at 3-, 4-, and 5-year assessments. In the group of patients without RDW increase in the first year, %FVC and %DLco did not decrease during the follow-up period. In conclusion, the changes in RDW in the first year after diagnosis may be useful surrogate markers to predict the long-term course of SSc-ILD

    Serum TARC Levels in Patients with Systemic Sclerosis: Clinical Association with Interstitial Lung Disease

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    Systemic sclerosis (SSc) is a multisystem fibrotic disorder with autoimmune background. Accumulating evidence has highlighted the importance of T helper (Th) 2 cells in the pathogenesis of SSc and its complications. Because thymus and activation-regulated chemokine (TARC) is a potent chemoattractant for Th2 cells, we measured serum TARC levels in SSc patients and analyzed their correlation with interstitial lung disease (ILD), a major complication of SSc. Serum TARC levels were significantly elevated in patients with SSc, especially in those with the diffuse subtype, compared with healthy controls. In particular, dcSSc patients with SSc-associated ILD (SSc-ILD) showed higher TARC levels than those without SSc-ILD. However, there was no significant correlation between serum TARC levels and pulmonary function in SSc patients. Serum TARC levels did not correlate with serum levels of interleukin-13, an important Th2 cytokine, either. Furthermore, in the longitudinal study, serum TARC levels did not predict the onset or progression of SSc-ILD in patients with SSc. These results were in contrast with those of KL-6 and surfactant protein D, which correlated well with the onset, severity, and progression of SSc-ILD. Overall, these results suggest that serum TARC levels are not suitable for monitoring the disease activity of SSc-ILD

    Serum Calponin 3 Levels in Patients with Systemic Sclerosis: Possible Association with Skin Sclerosis and Arthralgia

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    Systemic sclerosis (SSc) is a connective tissue disease characterized by tissue fibrosis and vasculopathy in various organs with a background of inflammation initiated by autoimmune abnormalities. Calponin 3 plays a role in the cell motility and contractibility of fibroblasts during wound healing in the skin. We aimed to evaluate serum calponin 3 levels in SSc patients and their association with clinical manifestations of SSc. Serum samples were collected from 68 patients with SSc and 20 healthy controls. Serum calponin 3 levels were examined using enzyme-linked immunosorbent assay kits, and their association with clinical features of SSc was statistically analyzed. The upper limit of the 95% confidence interval of serum calponin 3 levels in healthy controls was utilized as the cut-off value when dividing SSc patients into the elevated and normal groups. Serum calponin 3 levels were significantly higher in SSc patients than in healthy controls (mean (95% confidence interval), 15.38 (14.66–16.11) vs. 13.56 (12.75–14.38) ng/mL, p < 0.05). The modified Rodnan total skin thickness score was significantly higher in the elevated serum calponin 3 level group than in the normal level group (median (25–75th percentiles), 10.0 (2.0–16.0) vs. 6.5 (3.25–8.75), p < 0.05). Moreover, SSc patients with increased serum calponin 3 levels also had a higher frequency of arthralgia (40% vs. 9%, p < 0.05). Elevated serum calponin 3 levels were associated with skin sclerosis and arthralgia in SSc patients. Serum calponin 3 levels might be a biomarker that reflects the severity of skin sclerosis and joint involvement in SSc
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