142 research outputs found
Ultrasonication-Assisted Spray Ionization Mass Spectrometry for the Analysis of Biomolecules in Solution
In this paper, we describe a novel techniqueβultrasonication-assisted spray ionization (UASI)βfor the generation of singly charged and multiply charged gas-phase ions of biomolecules (e.g., amino acids, peptides, and proteins) from solution; this method employs a low-frequency ultrasonicator (ca. 40 kHz) in place of the high electric field required for electrospray ionization. When a capillary inlet is immersed into a sample solution within a vial subjected to ultrasonication, the solution is continually directed to the capillary outlet as a result of ultrasonication-assisted capillary action; an ultrasonic spray of the sample solution is emitted at the outlet of the tapered capillary, leading to the ready generation of gas-phase ions. Using an ion trap mass spectrometer, we found that singly charged amino acid and multiply charged peptides/proteins ions were generated through this single-step operation, which is both straightforward and extremely simple to perform. The setup is uncomplicated: only a low-frequency ultrasonicator and a tapered capillary are required to perform UASI. The mass spectra of the multiply charged peptides and proteins obtained from sample solutions subjected to UASI resemble those observed in ESI mass spectra
Surface-Assisted Laser Desorption/Ionization Mass Spectrometry on Titania Nanotube Arrays
Titania nanotube arrays (NTA) generated from anodizing processes are tested as the substrate for surface-assisted laser desorption/ionization mass spectrometry (SALDI MS). The background generated from titania NTA is very low, making the approach suitable for the analysis of small molecules. The upper detectable mass is βΌ29 kDa. Homogeneous sample deposition leads to good shot-to-shot reproducibility and suitability for quantitative analysis. Additionally, phosphopeptides can be selectively trapped on the titania NTA substrate, as illustrated by simply depositing a tryptic digest of Ξ²-casein followed by titania NTA SALDI MS analysis. The detection limit for small organics and peptides is in low fmol
Acute Fatty Liver of Pregnancy in a Taiwanese Tertiary Care Center: A Retrospective Review
SummaryObjectiveTo evaluate the demographics, clinical presentations, laboratory findings, and maternal and fetal outcomes in patients with acute fatty liver of pregnancy.Materials and MethodsA retrospective review was conducted of the records of pregnant patients with a diagnosis of acute fatty liver in a tertiary medical center over a 22-year period.ResultsEighteen patients with acute fatty liver of pregnancy were recruited, all of whom developed the disease in the third trimester. Eleven women (61%) were primigravid and four (22%) had twin pregnancies; six (33%) were diagnosed antepartum, and the other 12 (67%) were diagnosed postpartum. There were two maternal deaths (11%) and four fetal deaths (18%). The most common complications apart from severe liver dysfunction were acute renal failure (83%), hypoglycemia (61%), and disseminated intravascular coagulation (61%).ConclusionWomen who become acutely ill during the third trimester of pregnancy should undergo tests for acute fatty liver of pregnancy, including laboratory tests for assessing liver function and coagulation profile
Projected Economic and Financial Benefits of the 2017 Summer Universiade Games
In Western society, sport economic impact studies are often utilized to showcase the financial benefits for hosting mega sport event or to justify the spending for entering bids or covering infrastructure construction costs. This study projected economic impact of the 2017 Summer Universiade by examining the Taiwanese (the hosting country) residentsβ willingness to attendance and estimated individual spending (consumption) while attending the games. Through a series of convenience sampling surveys from February to April, 2017, 1,021 respondents (53.5% males and 45.3% females) reported their potential personal spending, willingness to attend the events, and preferred ticket price range. The results indicated that 61.5% of respondents expressed their willingness to purchase tickets. Projected cost for each individual potential game attendee was about 13.5 USDs. The estimated total revenues based on one million game attendeesβ (including local and non-local Taiwanese residents and foreign visitors) personal spending reached 154.1-million USDs. The researchers further compared the obtained figures with the finding of past sport economic impact studies and addressed the significance and rationale for selecting a modest impact multiplier for the calculation. Additional recommendations are offered in using impact study results to plan strategies for boosting tourism and winning bids for future event
Projected Economic and Financial Benefits of the 2017 Summer Universiade Games.
In Western society, sport economic impact studies are often utilized to showcase the financial benefits for hosting mega sport event or to justify the spending for entering bids or covering infrastructure construction costs. This study projected economic impact of the 2017 Summer Universiade by examining the Taiwanese (the hosting country) residentsβ willingness to attendance and estimated individual spending (consumption) while attending the games. Through a series of convenience sampling surveys from February to April, 2017, 1,021 respondents (53.5% males and 45.3% females) reported their potential personal spending, willingness to attend the events, and preferred ticket price range. The results indicated that 61.5% of respondents expressed their willingness to purchase tickets. Projected cost for each individual potential game attendee was about 13.5 USDs. The estimated total revenues based on one million game attendeesβ (including local and non-local Taiwanese residents and foreign visitors) personal spending reached 154.1-million USDs. The researchers further compared the obtained figures with the finding of past sport economic impact studies and addressed the significance and rationale for selecting a modest impact multiplier for the calculation. Additional recommendations are offered in using impact study results to plan strategies for boosting tourism and winning bids for future events
Nuclear Export Signal Mutation of Epidermal Growth Factor Receptor Enhances Malignant Phenotypes of Cancer Cells
Nuclear epidermal growth factor receptor (EGFR) has been shown to be correlated with drug resistance and a poor prognosis in patients with cancer. Previously, we have identified a tripartite nuclear localization signal (NLS) within EGFR. To comprehensively determine the functions and underlying mechanism of nuclear EGFR and its clinical implications, we aimed to explore the nuclear export signal (NES) sequence of EGFR that is responsible for interacting with the exportins. We combined in silico prediction with site-directed mutagenesis approaches and identified a putative NES motif of EGFR, which is located in amino acid residues 736-749. Mutation at leucine 747 (L747) in the EGFR NES led to increased nuclear accumulation of the protein via a less efficient release of the exportin CRM1. Interestingly, L747 with serine (L747S) and with proline (L747P) mutations were found in both tyrosine kinase inhibitor (TKI)-treated and -naΓ―ve patients with lung cancer who had acquired or de novo TKI resistance and a poor outcome. Reconstituted expression of the single NES mutant EGF
Effects of work-related factors on the breastfeeding behavior of working mothers in a Taiwanese semiconductor manufacturer: a cross-sectional survey
BACKGROUND: In recent years, the creation of supportive environments for encouraging mothers to breastfeed their children has emerged as a key health issue for women and children. The provision of lactation rooms and breast pumping breaks have helped mothers to continue breastfeeding after returning to work, but their effectiveness is uncertain. The aim of this study was to assess the effects of worksite breastfeeding-friendly policies and work-related factors on the behaviour of working mothers. METHODS: This study was conducted at a large Taiwanese semiconductor manufacturer in August-September 2003. Questionnaires were used to collect data on female employees' breastfeeding behaviour, child rearing and work status when raising their most recently born child. A total of 998 valid questionnaires were collected, giving a response rate of 75.3%. RESULTS: The results showed that 66.9% of survey respondents breastfed initially during their maternity leave, which averaged 56 days. Despite the provision of lactation rooms and breast pumping breaks, only 10.6% mothers continued to breastfeed after returning to work, primarily office workers and those who were aware of their company's breastfeeding-friendly policies. CONCLUSION: In conclusion, breastfeeding-friendly policies can significantly affect breastfeeding behaviour. However, an unfavourable working environment, especially for fab workers, can make it difficult to implement breastfeeding measures. With health professionals emphasizing that the importance of breastfeeding for infant health, and as only females can perform lactation, it is vital that women's work "productive role" and family "reproductive role" be respected and accommodated by society
Results based on 124 cases of breast cancer and 97 controls from Taiwan suggest that the single nucleotide polymorphism (SNP309) in the MDM2 gene promoter is associated with earlier onset and increased risk of breast cancer
<p>Abstract</p> <p>Background</p> <p>It has been suggested that the single nucleotide polymorphism 309 (SNP309, T -> G) in the promoter region of the MDM2 gene is important for tumor development; however, with regards to breast cancer, inconsistent associations have been reported worldwide. It is speculated that these conflicting results may have arisen due to different patient subgroups and ethnicities studied. For the first time, this study explores the effect of the MDM2 SNP309 genotype on Taiwanese breast cancer patients.</p> <p>Methods</p> <p>Genomic DNA was obtained from the whole blood of 124 breast cancer patients and 97 cancer-free healthy women living in Taiwan. MDM2 SNP309 genotyping was carried out by restriction fragment length polymorphism (RFLP) assay. The multivariate logistic regression and the Kaplan-Meier method were used for analyzing the risk association and significance of age at diagnosis among different MDM2 SNP309 genotypes, respectively.</p> <p>Results</p> <p>Compared to the TT genotype, an increased risk association with breast cancer was apparent for the GG genotype (OR = 3.05, 95% CI = 1.04 to 8.95), and for the TG genotype (OR = 2.12, 95% CI = 0.90 to 5.00) after adjusting for age, cardiovascular disease/diabetes, oral contraceptive usage, and body mass index, which exhibits significant difference between cases and controls. Furthermore, the average ages at diagnosis for breast cancer patients were 53.6, 52 and 47 years for those harboring TT, TG and GG genotypes, respectively. A significant difference in median age of onset for breast cancer between GG and TT+TG genotypes was obtained by the log-rank test (p = 0.0067).</p> <p>Conclusion</p> <p>Findings based on the current sample size suggest that the MDM2 SNP309 GG genotype may be associated with both the risk of breast cancer and an earlier age of onset in Taiwanese women.</p
Angiogenesis in Differentiated Placental Multipotent Mesenchymal Stromal Cells Is Dependent on Integrin Ξ±5Ξ²1
Human placental multipotent mesenchymal stromal cells (hPMSCs) can be isolated from term placenta, but their angiogenic ability and the regulatory pathways involved are not known. hPMSCs were shown to express integrins Ξ±v, Ξ±4, Ξ±5, Ξ²1, Ξ²3, and Ξ²5 and could be induced to differentiate into cells expressing endothelial markers. Increases in cell surface integrins Ξ±5 and Ξ²1, but not Ξ±4, Ξ±vΞ²3, or Ξ±vΞ²5, accompanied endothelial differentiation. Vascular endothelial growth factor-A augmented the effect of fibronectin in enhancing adhesion and migration of differentiated hPMSC through integrin Ξ±5Ξ²1, but not Ξ±vΞ²3 or Ξ±vΞ²5. Formation of capillary-like structures in vitro from differentiated cells was inhibited by pre-treatment with function-blocking antibodies to integrins Ξ±5 and Ξ²1. When hPMSCs were seeded onto chick chorioallantoic membranes (CAM), human von Willebrand factor-positive cells were observed to engraft in the chick endothelium. CAMs transplanted with differentiated hPMSCs had a greater number of vessels containing human cells and more incorporated cells per vessel compared to CAMs transplanted with undifferentiated hPMSCs, and overall angiogenesis was enhanced more by the differentiated cells. Function-blocking antibodies to integrins Ξ±5 and Ξ²1 inhibited angiogenesis in the CAM assay. These results suggest that differentiated hPMSCs may contribute to blood vessel formation, and this activity depends on integrin Ξ±5Ξ²1
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