Primary cutaneous anaplastic large cell lymphoma in a young child.
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Biomedical subjects
Publications and source records attributed to Yu-Cheng Lin.
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This study proposed a new design of a passive micromixer employing several J-shaped baffles in the tee channel to enhance mixing. The mixing performance of the device was investigated experimentally and by numerical simulation. The in-plane structured micromixer was fabricated using micromolding of SU-8 photoresist and PDMS. The mixing performance was demonstrated using image analysis to quantify the concentration distribution in the microchannel. The percentage of mixing increased as the number of baffles increased. The simulated and experimental results showed that the mixer with J-shaped baffles exhibited better mixing performance, and the percentage of mixing was about 1.2 to 2.2 times higher when compared to those without baffles, in the range of Reynolds number (Re) 5 to 350. The improvement in mixing performance was especially apparent at the short axial distance and at the lower Reynolds numbers. The results revealed that the J-shaped baffles could result in lateral convection in the main channel, resulting in improved mixing.
In this paper a new electroporation (EP) system is developed, which includes an EP microchip and a logic circuit, which combined with electrophoresis (ES), can provide site-specific enhancement of gene concentration. In this ES-EP microchip, an arc planar electrode provides the ES function for DNA attraction, and interdigitated array electrodes provide appropriate electric fields for the EP on the chip surface. In addition, the adherent cells can be manipulated in situ without detachment of the ES-EP microchip, which performs the "Lab on a chip". Experimental results have shown that the efficiency of gene transfection with an attracting-electric field (35.89%) becomes much higher than that without an attracting-electric field (16.62%). Cell numbers as low as 10(4) cells, and DNA as little as 4 microg are sufficient for evaluating the phenotypic effects following the over-expression of the introduced genes on the ES-EP microchip. The proposed system has the advantages of portability, cost-effectiveness, a high transfection rate and ease of operation.
In this paper the manipulation of Ca-alginate microspheres, using a microfluidic chip, for the encapsulation of gold nanoparticles is presented. Our strategy is based on hydrodynamic-focusing on the forming of a series of self-assembling sphere structures, the so-called water-in-oil (w/o) emulsions, in the cross-junction microchannel. These fine emulsions, consisting of aqueous Na-alginates, are then dripped into a solution of 20% calcium salt to accomplish Ca-alginate microspheres in an efficient manner. Experimental data show that microspheres with diameters ranging from 50 microm to 2000 microm with a variation less than 5% were precisely generated. The size and gap of the droplets are tunable by adjusting the relative sheath/sample flow rate ratio. Furthermore, we applied them to encapsulated gold nanoparticles, and this one shot operation performs the 'Lab on a Chip'.
Chloral hydrate is generally considered to be a safe hypnotic drug, and is commonly used for short-term sedation before diagnostic procedures. Its irritant actions to the mucous membranes are usually limited. We report a rare complication of chloral hydrate overdose in an infant. An 8-month-old male infant became unconscious and required ventilation support after an overdose of chloral hydrate was administered to provide sedation for an ophthalmologic examination. White plaques and sloughing of the oropharyngeal mucosa were observed on the next day. Esophagogastroscopy revealed severe corrosive lesions on the whole esophagus. The child recovered after supportive treatment and his oral intake remained well without dysphagia after 1 year. This report illustrates the potential corrosive effect of chloral hydrate. Strict attention should be paid to the dosing and administration protocol of chloral hydrate in infants. The condition of the oropharyngeal mucosa should be carefully monitored after chloral hydrate administration.
OBJECTIVE: The objective of this study was to investigate whether exposure to aluminum, gallium, indium, arsenic, and antimony induces lipid peroxidation in humans. METHODS: Whole blood and urine levels of 103 exposed electronic industry workers and 67 referents were analyzed by use of inductively coupled plasma mass spectrometry. Malondialdehyde (MDA), the product of lipid peroxidation, was determined by high-performance liquid chromatography. RESULTS: The mean plasma MDA level in the 103 workers was significantly higher than that in 67 referents. The levels of MDA in the exposed workers were correlated significantly with the levels of urinary gallium and arsenic. CONCLUSIONS: Malondialdehyde as an index of lipid peroxidation can be induced by gallium and arsenic exposure. By reducing exposure to these metals, biologic effects such as lipid peroxidation may also be diminished.
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We found that the PCR could be dramatically enhanced by Au nanoparticles. With the addition of 0.7 nM of 13 nm Au nanoparticles into the PCR reagent, the PCR efficiency was increased. Especially when maintaining the same or higher amplification yields, the reaction time could be shortened, and the heating/cooling rates could be increased. The excellent heat transfer property of the nanoparticles should be the major factor in improving the PCR efficiency. Different PCR systems, DNA polymerases, DNA sizes and complex samples were compared in this study. Our results demonstrated that Au nanoparticles increase the sensitivity of PCR detection 5- to 10-fold in a slower PCR system (i.e. conventional PCR) and at least 10(4)-fold in a quicker PCR system (i.e. real-time PCR). After the PCR time was shortened by half, the 100 copies/microl DNA were detectable in real-time PCR with gold colloid added, however, at least 10(6) copies/microl of DNA were needed to reach a detectable signal level using the PCR reagent without gold colloid. This innovation could improve the PCR efficiency using non-expensive polymerases, and general PCR reagent. It is a new viewpoint in PCR, that nanoparticles can be used to enhance PCR efficiency and shorten reaction times.
AIM: To demonstrate the prevalence of sonographic fatty liver, overweight and ischemic heart disease (IHD) among the male workers in Taiwan, and to investigate the possible association of these three factors. METHODS: From July to September 2003, a total of 2 088 male aircraft-maintenance workers aged from 22 to 65 years (mean 40.5) underwent an annual health examination, including anthropometrical evaluation, blood pressure measurement, personal medical history assessment, biochemical blood analysis, abdominal ultrasonographic examination and digital electrocardiography (ECG). The Student's t-test, chi(2) test and multivariate logistic regression analysis were utilized to evaluate the relationship between IHD and salient risk factors. RESULTS: The all-over prevalence of overweight was 41.4%, and that of fatty liver was 29.5% (mild, moderate and severe fatty liver being 14.5%, 11.3%, and 3.7%, respectively); while the prevalence of ischemic changes on ECG was 17.1% in this study. The abnormal rates for conventional IHD risk factors including hypertension, dyslipidemia, hyperglycemia and overweight increased in accordance with the severity of fatty liver. Overweight and severity of fatty liver were independently associated with increased risks for developing IHD. Overweight subjects had a 1.32-fold (95%CI: 1.01-1.73) increased IHD risk. Participants with mild, moderate, and severe fatty liver had a 1.88-fold (95%CI: 1.37-2.6), 2.37-fold (95%CI: 1.66-3.37) and 2.76-fold (95%CI: 1.62-4.72) increased risk for developing IHD. The prevalence of ischemic ECG for the fatty liver-affected subjects with or without overweight was 30.1% and 19.1%, while that of overweight subjects free from fatty liver was 14.4%. Compared to the subjects without fatty liver nor overweight, IHD risk for the three subgroups above was as follows: OR: 2.95 (95%CI: 2.31-4.09), OR: 1.60 (95%CI: 1.07-2.39) and OR: 1.11 (95%CI: 0.78-1.56), respectively. CONCLUSION: The presence of fatty liver and its severity should be carefully considered as independent risk factors for IHD. Results of the study suggest the synergistic effect between fatty liver and overweight for developing IHD. Abdominal sonographic examination may provide valuable information for IHD risk assessment in addition to limited report about liver status, especially for overweight males.
The interface and surface properties and the wetting behavior of polymer-solvent mixtures are investigated using Monte Carlo simulations and self-consistent field calculations. We carry out Monte Carlo simulations in the framework of a coarse-grained bead-spring model using short chains (oligomers) of N(P)=5 beads and a monomeric solvent, N(S)=1. The self-consistent field calculations are based on a simple phenomenological equation of state for compressible binary mixtures and we employ Gaussian chain model. The bulk behavior of the polymer-solvent mixture belongs to type III in the classification of van Konynenburg and Scott [Phil. Trans. R. Soc. London, Ser. A 298, 495 (1980)]. It is characterized by a triple line on which the polymer-liquid coexists with solvent-vapor and a solvent-rich liquid. The solvent is not homogeneously distributed across the dense polymer film but tends to accumulate at the surface and the polymer-vapor interface. This solvent enrichment at the interface and surface becomes more pronounced upon increasing the vapor pressure and alters the surface and interface tensions. This effect gives rise to a nonmonotonic dependence of the contact angle on the vapor pressure and one might observe reentrant wetting. The results of the Monte Carlo simulations and the self-consistent field calculations qualitatively agree. The profiles of drops are investigated by Monte Carlo simulations and a pronounced solvent enrichment is observed at the wedge formed by the substrate and the liquid-vapor interface at the three-phase contact line.
Simulation and experimental demonstration of the in vitro gene delivery enhancement using electrostatic forces and electroporation (EP) microchips were conducted. Electroporation is a technique with which DNA molecules can be delivered into cells using electric field pulses. This study demonstrates that plasmid DNA can be attracted to the cell surfaces at the specific regions using an electrostatic force. Therefore, the DNA concentration on the cell surface is dramatically increased, which highly enhances the gene transfection efficiency compared to that without an attracting-electric field. The electrostatic force can be designed into specific regions, where the DNA plasmids are attracted to, to provide the region-targeting function. In this micro-device, the top electrode and the interdigitated electrodes provided the DNA attracting-electric field, and the interdigitated electrodes provided adequate electric fields for the electroporation process on the chip surface. Using the EP microchip, cells could be manipulated in situ without detachment if adherent cells were used for electroporation. Five different cells of two different types, primary cell and cell line, were successfully transfected under multi-pulse or single pulse electric field stimulation without applying an attracting-electric field. This study simulated and analyzed the electric field distributions at the DNA attracting and electroporation processes, and successfully demonstrated that the electrostatic force attracted DNA plasmids to specific regions and highly enhanced the gene delivery. In summary, this EP microchip should provide many potential applications for gene therapy.
Au nanoparticles modified with 21-base thiolated-oligonucleotides have been evaluated as delivery vehicles for the development of a nonviral transfection platform. The electromigration combined with electroporation for DNA delivery in an osteoblast like cell was employed to test on microchips. Electroporation introduces foreign materials into cells by applying impulses of electric field to induce multiple transient pores on the cell membrane through dielectric breakdown of the cell membrane. On the basis of the characteristic surface plasmon of the Au particles, UV-vis absorption was utilized to qualitatively judge the efficiency of delivery. Transmission electron microscopy images and atomic absorption measurements (quantitative analysis) provided evidence of the bare Au and Au/oligonucleotide nanoparticles before and after electroporation and electromigration function. The experiments demonstrated that electrophoretic migration followed by electroporation significantly enhanced the transportation efficiency of the nanoparticle-oligonucleotide complexes as compared with electroporation alone. Most interestingly, Au capped with oligonucleotides led to optimal performance. On the other hand, the bare Au colloidal suspensions resulted in aggregation, which might be an obstacle to the internalization process. In addition, analytical results demonstrated an increase in the local particle concentrations on the cell surface that provided additional support for the mechanism underlying the improved Au nanoparticle transportation into cells in the presence of electromigration function.
A high efficiency DNA extraction microchip was designed to extract DNA from lysed cells using immobilized beads and the solution flowing back and forth. This chip was able to increase the extraction efficiency by 2-fold when there was no serum. When serum existed in the solution, the extraction efficiency of immobilized beads was 88-fold higher than that of free beads. The extraction efficiency of the microchip was tested under different conditions and numbers of E. coli cells. When the number of E. coli cells was between 10(6) and 10(8) in 25 microl of whole blood, the extraction efficiency using immobilized beads was only slightly higher than that using free beads (10(0) to 10(1) fold). When the number of E. coli cells was in the range 10(4) to 10(6) in 25 microl of whole blood, the extraction efficiency of immobilized beads was greater than that of the free beads (10(1) to 10(2) fold). When the number of E. coli cells was lower, in the range 10(3) to 10(4) in 25 microl of whole blood, the extraction efficiency of immobilized beads was much higher than that of the free beads (10(2) to 10(3) fold). This study indicated that DNA could be efficiently extracted even when the number of bacterial cells was smaller (10(5) to 10(3)). This microfluidic extraction chip could find potential applications in rare sample genomic study.
The paper proposed novel designs to pinch the transverse diffusion of the sample in the injection mode using microelectrodes to generate the potential difference at the channel intersection in the capillary electrophoresis (CE) microchip. A pair of microelectrodes was used to conduct the injection channel and the separation channel, which directly provided the potential to pinch the sample without using a power supply. These new designs of the CE microchip simplify the electric circuitry and improve performance. Simulations were performed using the CFD-ACE[trade mark sign] software. The mechanisms of diffusion and electrophoresis were employed in the numerical simulation. The injection and separation processes of the sample were simulated and the parameters of the present design were investigated numerically.
This study presents comparisons of ethnic difference in anthropometric characteristics among four peoples, i.e., Chinese, Japanese, Korean, and Taiwanese, in East Asia. Anthropometric data from the four East Asian countries were compared. The means of 33 body dimensions and 31 bodily proportions are presented. Also, 15 segmental proportions are illustrated. The results of statistical analyses showed that there is a significant morphological difference among these peoples in the same region. The Mainland Chinese body shape has a narrower body with mid-range limbs. The Japanese body shape is wider with shorter limbs. The Korean body shape is mid-range among the four peoples, but the upper limbs are longer. The Taiwanese body shape has wide shoulder and narrow hip with large hands and long legs. The ethnic diversity in bodily proportions should be considered as well as the mean dimensions.
BACKGROUND: Angina is a hallmark symptom of cardiovascular disease, which has become an important public health issue in Taiwan. The purpose of this study was to examine the prevalence of angina and its risk factors in elderly Taiwanese. METHODS: The study was based on a government-sponsored health examination performed in Tao-Yuan, North Taiwan, from April to June 2001. A total of 2060 participants aged 65 years and older were enrolled. Data were collected through a physician-conducted Rose questionnaire, a biochemical blood test, and a physical examination. Multivariate logistic regression was used to evaluate the relationship between angina and risk factors. RESULTS: Prevalence of angina was 15.0% in this study, 15.1% in men, and 14.4% in women. Women had a significantly higher body mass index (BMI), total serum cholesterol, and triglyceride. Participants with hypertension had a 1.6-fold 95% confidence interval (CI): 1.2-2.0 increased risk of having angina, 1.4-fold (95% CI: 1.0-1.9) increased risk for men and 2.1-fold (95% CI: 1.3-3.5) for women. Diabetes mellitus was associated with a 1.8-fold (95% CI: 1.2-2.6) increase in the risk for men. Conventional cardiovascular risk factors such as BMI, cholesterol, triglyceride, and smoking were not significantly associated with angina. CONCLUSIONS: The findings of this study suggest the need to prioritize hypertension treatment for elderly Taiwanese in both genders, and to provide adequate diabetes mellitus treatment for men, as these conditions are associated with the development of angina, a clinical indicator of cardiovascular disease.
BACKGROUND: Children beyond infancy (>12 months of age) rarely have gastroesophageal reflux disease (GERD). Underlying diseases may contribute to the persistence of GERD from infancy to childhood. This study compares the clinical course of children with GERD with and without underlying diseases. METHODS: The authors studied the role of underlying diseases responsible for GERD in children beyond infancy by a retrospective analysis. From 1985 to 2000, GERD was confirmed in 34 children beyond infancy in the National Taiwan University (median age 2.5 years, range 1.1-9.7 years), according to the inclusion criteria of reflux symptoms and the fraction of pH < 4 above 5% in the 24-h esophageal pH study. The patients were divided into two groups: those without underlying diseases (n=10) and those with underlying diseases (n=24). The follow-up duration was 0.5-17.1 years (median 4.5 years). RESULTS: The underlying diseases responsible for GERD in 24 children included neurological impairment (n=14), repaired esophageal atresia (n=2), hiatal hernia (n=3), repaired congenital diaphragmatic hernia (n=2), and congenital heart disease (n=3). At the end of the study, 9 of 10 children with GERD beyond infancy and without underlying diseases were free of symptoms without any need for further medical treatment. In contrast, 10 of 14 children with neurological disorders had persisting reflux symptoms (Kaplan-Meier analysis, P=0.02, log-rank test). CONCLUSIONS: Neurological impairment and esophageal or diaphragmatic anatomic abnormalities were frequently associated with GERD beyond infancy. Children with underlying diseases, especially with neurological impairment, ran a refractory course, while those without underlying diseases enjoyed a longer symptom-free life.
Group B streptococcal (GBS) infection is an important cause of perinatal morbidity and mortality. We report the use of extracorporeal membrane oxygenation (ECMO) to rescue a newborn with refractory GBS sepsis and meningitis who developed cardiopulmonary failure. This 2-day-old infant weighed 2640 g and was born to a healthy mother at full term. Respiratory distress, hypotension, and persistent pulmonary hypertension developed on the second day of life. The clinical condition deteriorated rapidly despite conventional treatment, and venoarterial ECMO was established to rescue this moribund newborn. During ECMO, the patient regained stable hemodynamics and good oxygenation, and infection was controlled. ECMO was used for 90 hours and the baby was weaned smoothly. Neurologic assessment after ECMO revealed hydrocephalus, abnormal electroencephalogram, and increased brain auditory evoked potential threshold. This report emphasizes that ECMO may be considered to rescue neonatal patients with cardiopulmonary failure due to GBS sepsis. Possible neurologic complications after ECMO should be carefully monitored.