349 research outputs found
Effects of human parvovirus B19 VP1 unique region protein on macrophage responses
<p>Abstract</p> <p>Background</p> <p>Activity of secreted phospholipase A (sPLA2) has been implicated in a wide range of cellular responses. However, little is known about the function of human parvovirus B19-VP1 unique region (VP1u) with sPLA2 activity on macrophage.</p> <p>Methods</p> <p>To investigate the roles of B19-VP1u in response to macrophage, phospholipase A2 activity, cell migration assay, phagocytosis activity, metalloproteinase assay, RT-PCR and immunoblotting were performed.</p> <p>Results</p> <p>In the present study, we report that migration, phagocytosis, IL-6, IL-1β mRNA, and MMP9 activity are significantly increased in RAW264.7 cells by B19-VP1u protein with sPLA2 activity, but not by B19-VP1uD175A protein that is mutated and lacks sPLA2 activity. Additionally, significant increases of phosphorylated ERK1/2 and JNK proteins were detected in macrophages that were treated with B19-VP1u protein, but not when they were treated with B19-VP1uD175A protein.</p> <p>Conclusion</p> <p>Taken together, our experimental results suggest that B19-VP1u with sPLA2 activity affects production of IL-6, IL-1β mRNA, and MMP9 activity, possibly through the involvement of ERK1/2 and JNK signaling pathways. These findings could provide clues in understanding the role of B19-VP1u and its sPLA2 enzymatic activity in B19 infection and B19-related diseases.</p
Using Sidereal Rotation Period Expressions to Calculate the Sun’s Rotation Period through Observation of Sunspots
We utilize sidereal rotation period expressions to calculate the sun’s rotation period via sunspot observation. From the well-known astronomical sites, we collected sunspot diagrams for 14 months, from January 2013 to February 2014, to analyze, compare, and implement statistical research. In addition to acquiring the average angular rate of the movement of sunspots, we found that even the same number of sunspots moved at different angular rates, and generally the life of larger sunspots is longer than 10 days. Therefore the larger sunspots moved around the back of the sun, and a handful of relatively smaller sunspots disappeared within a few days. The results show that the solar rotation period varied with the latitude. However, if we take the average of the sunspots at high and low latitudes, we find that the calculated value is very close to the accredited values
High-yield antibody production using targeted integration and engineering CHO host
To identify the high expression sites in the CHO cells, we employed NGS to analyze the integration sites of a high producing cell line (titer \u3e 3g/L). The pair-end reads with one read mapped to the vector and the other read mapped to the CHO reference genome are extracted to identify the integration sites. To test the expression activity of the integration sites, we employed CRISPR/Cas9 to specifically integrate the antibody gene into CHO genome for expression. Our data showed 4 integration sites are in the high producing cell line. Among the 4 integration site, one integration site was tested by CRISPR/Cas9 for target integration of antibody gene for expression. The target integrated cell pool present higher expression level (130 mg/L/copy) and less copy number when compared other integration sites. Through single-copy integration method, we can also achieve 60-150 mg/L/copy in a batch culture. About 80% of the single-copy cell clones were stable at generation 60. We have also applied the CHO-specific microarray transcriptomics technology to identify genes that contribute to high productivity. Transfection of our proprietary dual promoter vector J 1.0 resulting in 1.65 to 2.4 fold increase in the expression in engineered CHO DXB11 host. Through fed-batch process development, 3 – 5 g/L mAb productivity can be achieved through targeted integration and engineered CHO host
Comparison of AR and physical experiential learning environment in supporting product innovation
This article compares how virtual and physical learning aids enhance learners’ product innovation capability, that is, design experiences and domain knowledge. The virtual aid utilises augmented reality (AR) allowing learners to experience a range of animated mechanisms using smart devices. The legacy physical aid mechanisms were made using three-dimensional printers. We studied the effects of both manipulatives on learners’ understanding of mechanical movements, for example, rack and pinion, and Geneva mechanism. To investigate learning impact of each aid, we compared the experimental results derived from two learners groups (13 participants each). This study provides a case to support product innovation education under an experiential learning environment. The outcomes showed that both aids were useful in enhancing design experiences and domain knowledge. Pre-and-post attention, relevance, confidence and satisfaction motivation of both aids was found to be similar. However, distinctive differences were observed in terms of divergent search for ideation, suggesting for further research in combining both aids. We also found that learners’ learning motivation is lower in AR-based aid
Development of high-producing CHO cell lines through target-designed strategy
Productivity and stability are critical for the protein drug producing cell lines for manufacturing. Given that the integration sites of gene of interest (GOI) could contribute remarkable effect on the productivity and stability of GOI expression, we intended to develop a targeting-designed approach to generate the high-producing cell lines in a time-saving and less labor-intensive method through targeting the active and stable regions. To identify the active and stable regions located in CHO genome, two approaches were applied in our experiments. Firstly, the integration sites of GOI in cell clones developed by random integration were identified by whole genome sequencing. Secondly, we developed transposon-mediated low copy integration to discover novel active region located in CHO genome. It is interesting that the productivity per integrated GOI in cell clones developed by transposon system was more than two times to that in cell clones developed by random integration (random integration: 20-40 mg/L/copy; transposon-mediated integration: 40-140mg/L/copy). In addition, about 80% of cell clones developed by transposon system maintained the stability of antibody titer after culturing for 60 generations. These results implied that the potential active and stable integration region in the cell clones developed by transposon system. The identified integration regions could be applied for target integration. In order to verify the expression activity and stability of the integration sites, we employed CRISPR/Cas9 to specifically integrate the antibody gene into CHO genome for expression. Our data showed the cell pool generated by knock-in of expression vector into the IS1 integration site present higher expression titer than cell pools generated by integration into other sites or random integration. We further cultured the single cell clones derived from this cell pool by Clonepix and limiting dilution. These single cell clones have high expression titer ranging from 254 to 804 mg/L in batch culture of after 6 Days. A single cell clone(376 mg/L in batch culture) can reached 2 g/L in fed-batch culture. The stability analysis showed this clone maintain stable expression of GOI after 60 generation. Here, we demonstrated the generation of stable cell line with high protein expression by CRISPR/Cas9 mediated target integration. This approach will cost less time and labor than traditional method
Tet oncogene family member 2 gene alterations in childhood acute myeloid leukemia
Background/PurposeMutations in the tet oncogene family member 2 gene (TET2) are frequently found in adult patients with acute myeloid leukemia (AML). Reports of TET2 mutations in children are limited. We assessed the prevalence of TET2 mutations in Taiwanese children with AML and analyzed their prognosis.MethodsBetween 1997 and 2010, a total of 69 consecutive children with AML were enrolled at the National Taiwan University Hospital. The analysis for TET2 mutations was performed using direct sequencing. Clinical characteristics and overall survival (OS) were compared between patients with and without TET2 alterations.ResultsIntronic and missense mutations were identified. No nonsense or frameshift mutations were observed. Two putative disease-causing missense mutations (S609C and A1865G) were identified in one patient. We estimated the prevalence of TET2 mutations in the current patient population to be 1.4%. The most common polymorphism was I1762V (45%), followed by V218M (12%), P29R (6%), and F868L (6%). Patients with polymorphism I1762V had an increased 10-year survival rate compared with patients without I1762V (48.4% vs. 25.7%, p = 0.049) by Chi-square test; OS was not different when examined using the Kaplan–Meier method (p = 0.104).ConclusionThe prevalence of TET2 mutations in children with AML compared with adults with AML was lower and less complex. Patient prognosis associated with TET2 mutations in children requires further investigation
Use and effectiveness of dapagliflozin in patients with type 2 diabetes mellitus: a multicenter retrospective study in Taiwan
Aims/Introduction To investigate the clinical outcomes of patients with type 2 diabetes mellitus (T2DM) who initiated dapagliflozin in real-world practice in Taiwan. Materials and Methods In this multicenter retrospective study, adult patients with T2DM who initiated dapagliflozin after May 1st 2016 either as add-on or switch therapy were included. Changes in clinical and laboratory parameters were evaluated at 3 and 6 months. Baseline factors associated with dapagliflozin response in glycated hemoglobin (HbA1c) were analyzed by univariate and multivariate logistic regression. Results A total of 1,960 patients were eligible. At 6 months, significant changes were observed: HbA1c by −0.73% (95% confidence interval [CI] −0.80, −0.67), body weight was -1.61 kg (95% CI −1.79, −1.42), and systolic/diastolic blood pressure by −3.6/−1.4 mmHg. Add-on dapagliflozin showed significantly greater HbA1c reduction (−0.82%) than switched therapy (−0.66%) (p = 0.002). The proportion of patients achieving HbA1c <7% target increased from 6% at baseline to 19% at Month 6. Almost 80% of patients experienced at least 1% reduction in HbA1c, and 65% of patients showed both weight loss and reduction in HbA1c. Around 37% of patients had at least 3% weight loss. Multivariate logistic regression analysis indicated patients with higher baseline HbA1c and those who initiated dapagliflozin as add-on therapy were associated with a greater reduction in HbA1c. Conclusions In this real-world study with the highest patient number of Chinese population to date, the use of dapagliflozin was associated with significant improvement in glycemic control, body weight, and blood pressure in patients with T2DM. Initiating dapagliflozin as add-on therapy showed better glycemic control than as switch therapy
Association of combination antiretroviral therapy with risk of neurological diseases in patients with HIV/AIDS in Taiwan: a nested case-control study
Heterogeneous neurocognitive impairment remains an important issue, even in the era of combination antiretroviral therapy (cART), with an incidence ranging from 15% to 65%. Although ART drugs with higher penetration scores to the central nervous system (CNS) show better HIV replication control in the CNS, the association between CNS penetration effectiveness (CPE) scores and neurocognitive impairment remains inconclusive. To explore whether ART exposure is associated with the risk of neurological diseases among patients with HIV/AIDS, this study in Taiwan involved 2,571 patients with neurological diseases and 10,284 matched, randomly selected patients without neurological diseases between 2010 and 2017. A conditional logistic regression model was used in this study. The parameters for ART exposure included ART usage, timing of exposure, cumulative defined daily dose (DDD), adherence, and cumulative CPE score. Incident cases of neurological diseases, including CNS infections, cognitive disorders, vasculopathy, and peripheral neuropathy, were obtained from the National Health Insurance Research Database in Taiwan. Odds ratios (ORs) for the risk of neurological diseases were conducted using a multivariate conditional logistic regression model. Patients with a history of past exposure (OR: 1.68, 95% confidence interval [CI]:1.22–2.32), low cumulative DDDs (< 2,500) (OR: 1.28, 95% CI: 1.15–1.42), low adherence (0 < adherence (ADH) ≤ 0.8) (OR: 1.46, 95% CI: 1.30–1.64), or high cumulative CPE scores (>14) (OR: 1.34, 95% CI: 1.14–1.57) had a high risk of neurological diseases. When stratified by classes of ART drugs, patients with low cumulative DDDs or low adherence had a high risk of neurological diseases, including NRTIs, PIs, NNRTIs, INSTIs, and multi-drug tablets. Subgroup analyses also suggested that patients with low cumulative DDDs or low adherence had a high risk of neurological diseases when they had high cumulative CPE scores. Patients with high cumulative DDDs or medication adherence were protected against neurological diseases only when they had low cumulative CPE scores (≤ 14). Patients may be at risk for neurological diseases when they have low cumulative DDDs, low adherence, or usage with high cumulative CPE scores. Continuous usage and low cumulative CPE scores of ART drugs may benefit neurocognitive health in patients with HIV/AIDS
Do Learners’ Characteristics Matter? An Exploration of Mobile-learning Adoption in Self-directed Learning
This paper aims to identify individual characteristics that motivate learners to use mobile-learning. It sheds light on our current knowledge by a) examining an m-learning adoption model which accounts for learners’ characteristics (learning style and personal innovativeness) in addition to previously studied mobile platform characteristics and b) considering the context in which learning occurs (formal and informal). A framework has been introduced and empirically tested. Results suggest that individuals’ learning style and perceived playfulness influence m-learning usage in both learning situations; while performance expectancy and personal innovativeness are only influential in specific learning contexts. This study highlights the role of learners’ characteristics in m-learning adoption and emphasizes the importance of distinguishing between various types of m-learning. This multi-disciplinary research enriches m-learning literature and offers practical implications for educators using mobile technologies as well as developers of virtual learning platforms
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