Biomedical subjects

Yu-Chih Chen

Publications and source records attributed to Yu-Chih Chen.

8 recordsLinked to original sources

PubMed2025

In vitro modeling of human dorsal root ganglion neurons for GCaMP6-based calcium imaging of sensory responses to HSV-1 infection.

Dorsal root ganglion (DRG) neurons play a pivotal role in transmitting sensory information from the periphery to the central nervous system, mediating diverse stimuli such as pain, touch, and temperature. Despite advances, translating findings from rodent models to human applications remains challenging due to species-specific differences, necessitating reliable human DRG neuron models. The immortalized human DRG neuronal cell line HD10.6, derived from embryonic DRG cells and capable of differentiating into functional nociceptive-like neurons, offers a promising in vitro system for studying sensory neuron biology and drug screening. This study explores the utility of GCaMP6s, a genetically encoded calcium indicator, as a molecular tool for imaging sensory activation in HD10.6 cells. To establish HD10.6 as a robust human DRG model, we constructed and characterized adeno-associated virus (AAV9) vectors for efficient GCaMP6s delivery. Differentiated HD10.6 cells were efficiently transduced, and calcium dynamics were validated to assess functional responses to sensory stimuli. The results showed that AAV9 serotype was sufficient to infect HD10.6 and the GCaMP6s was successfully introduced into the cells. The HD10.6-GCaMP6s responded to capsaicin well under the appropriate condition. A series of viral infection studies indicated that herpesvirus HSV-1 triggered robust calcium influx within 5 min after the exposure to the virus. Our findings highlight the potential of GCaMP6s-expressing HD10.6 cells as a high-throughput platform for studying nociception, neuronal signaling, host cell responses to viruses, and therapeutic interventions, bridging the gap between preclinical research and clinical applications.

Humans↗

PubMed2006

The effect of intermittent nasogastric feeding on preventing aspiration pneumonia in ventilated critically ill patients.

This randomized, controlled study employed two feeding protocols for 107 participants in two intensive care units (ICUs) of a medical center to investigate the efficacy of intermittent nasogastric (NG) feeding in preventing aspiration pneumonia in critically ill patients on ventilators. The participants were randomly assigned to receive continuous (51 patients) or intermittent (56 patients) feeding. The primary outcomes, including gastric emptiness index and pulmonary aspiration index, were examined on Day 0 and Day 7 of the intervention. In addition, patients were followed up to the 21st day to evaluate the secondary outcomes, which included length of stay (LOS) in the ICU and airway status. The results showed that the patients in the intermittent feeding group had a higher total intake volume at Day 7 (p = .000), had been extubated earlier at Day 21 (p = .002), and had a lower risk of aspiration pneumonia (odds ratios: 0.146, 95% CI = 0.062-0.413, p = .000) than the patients in the control group. Participants being treated with a high dose of dopamine were 2.95 times more likely to get aspiration pneumonia than those receiving a low dose of dopamine (95 % CI = 1.076-8.107, p = .035). However, there was no significant difference between the two groups'; LOS. The results of this study provide evidence that clinical caregivers may use to make better decisions in terms of feeding methods for critically ill patients.

Critical Illness↗

PubMed2006

[Family satisfaction with systematic nursing instructions in a pediatric emergency department].

This study aimed to evaluate satisfaction with systematic nursing instructions among family members of pediatric emergency patients and to determine the degree to which family members complied with instructions provided. All subjects recruited were from a single medical center. A structured questionnaire was used to collect data. Written systematic nursing instructions were given to patient family members, supplemented by verbal interpretation. Family members were then contacted by telephone at 24 and 72 hours, respectively, after emergency department (ED) discharge. Questionnaires were completed and mailed back to the hospital within 72 hours. The 362 valid responses returned out of 700 questionnaires dispensed represented a response rate of 51.7%. Data were analyzed using descriptive statistics, t-test, one-way ANOVA and Scheffe's test. Main study findings included: (1) Family member satisfaction with systematic nursing instructions was 83.8%; (2) Families with higher educational levels had higher expectations in terms of health education and were less satisfied with instructions provided; and (3) 61.4% of participants reported symptom relief after following systematic nursing instructions and, as a result, did not need to return for further clinical help. Results demonstrate that systematic nursing instructions are effective in improving family satisfaction and compliance with nursing instructions. In addition, these instructions help reduce the rate of unplanned return visits to the pediatric ED.

Adult↗

PubMed2005

A novel in vitro retinal differentiation model by co-culturing adult human bone marrow stem cells with retinal pigmented epithelium cells.

Human retinal pigment epithelium (HRPE) cells are important in maintaining the normal physiology within the neurosensory retina and photoreceptors. Recently, transplantation of HRPE has become a possible therapeutic approach for retinal degeneration. By negative immunoselection (CD45 and glycophorin A), in this study, we have isolated and cultivated adult human bone marrow stem cells (BMSCs) with multilineage differentiation potential. After a 2- to 4-week culture under chondrogenic, osteogenic, adipogenic, and hepatogenic induction medium, these BMSCs were found to differentiate into cartilage, bone, adipocyte, and hepatocyte-like cells, respectively. We also showed that these BMSCs could differentiate into neural precursor cells (nestin-positive) and mature neurons (MAP-2 and Tuj1-positive) following treatment of neural selection and induction medium for 1 month. Furthermore, the plasticity of BMSCs was confirmed by initiating their differentiation into retinal cells and photoreceptor lineages by co-culturing with HRPE cells. The latter system provides an ex vivo expansion model of culturing photoreceptors for the treatment of retinal degeneration diseases.

Bone Marrow Cells↗

PubMed2004

Important computer competencies for the nursing profession.

Nursing requires computer competencies. This study aimed at identifying those competencies required for the nursing profession in Taiwan. The Delphi technique was deployed in this study. In the Delphi questionnaires, computer competencies were sorted into seven domains: concepts of hardware, software, and networks; principles of computer applications; skills of computer usage; program design; limitations of the computer; personal and social issues; attitudes toward the computer. In three Delphi questionnaires, nursing informatics experts gave us their opinions on the importance of each computer competency for the nursing profession. The experts also designated when the competency should be cultivated. This study provides a comprehensive list for nursing professionals to check on their computer competence. The results of this study should also serve as good references for teachers and schools in designing related curriculums.

Adult↗

PubMed2003

Analysis of the envelope proteins of heat-shocked Vibrio parahaemolyticus cells by immunoblotting and biotin-labeling methods.

Vibrio parahaemolyticus, a common enteropathogen in tropical and subtropical coastal regions, exhibits significant adaptive acid tolerance response and heat-shock response, and the envelope proteins induced by stresses are suggested to be associated with virulence. This work examined the heat-shock proteins located in the envelope of V. parahaemolyticus by two rapid methods; namely, the immunoblotting and biotin-labeling methods. The bacterial cells were cultured at 25 C and heat shocked at 37 or 42 C for 1 or 2 hr. The cells were first lysed, then proteins were separated by gel electrophoresis and probed with antiserum raised against heat-shocked cells. Next, the heat-shocked cells were examined by labeling with water soluble sulfo-NHS-LC-biotin. Proteins of 33, 61, 66, 71, 78, 92 and 101 kDa were induced, while 55, 86, 102, 120 and 160 kDa proteins were markedly enhanced in the envelope of the heat-shocked V. parahaemolyticus cells. The biotin tagged envelope proteins were purified using a monomeric avidin column, and the N-terminal sequence was determined and compared with other high identity protein sequences. The sequence results suggest that Vph1 (55 kDa), Vph2 (46 kDa) and Vph3 (42 kDa) are de novo synthesized heat-shock proteins located in the envelope of this pathogen, and the functions of these proteins in stress protection and virulence have yet to be determined.

Amino Acid Sequence↗

PubMed2002

The anticorrosion ability of titanium nitride (TiN) plating on an orthodontic metal bracket and its biocompatibility.

Typically, an orthodontic metal bracket is made from stainless steel. It has been shown that such metal may corrode in an acid- and chloride-rich environment. The purpose of the current study was to investigate a titanium nitride (TiN) ion-plated stainless steel orthodontic bracket's anticorrosion properties and compare its biocompatibility with that of non-TiN-plated brackets. The stainless-steel brackets studied here were tested in acidic artificial saliva. The plated metal bracket was produced by the titanium nitride (TiN) ion-plating method. The TiN-plating on the bracket surface was demonstrated to be successful by EDX analysis. The quantity of metallic-ion release under test immersion solutions was analyzed by atomic absorption spectrophotometry. Both TiN- and non-TiN-plated brackets may release detectable ions into the test solution, including nickel, chromium, manganese, copper, and iron (ferric). The anticorrosion ability of the plated bracket was analyzed by means of inductively coupled plasma atomic emission spectroscopy. The results revealed that the TiN-plated metal bracket did not increase the anticorrosion ability of the standard bracket. The biocompatibility of the TiN plating versus the standard bracket material resulting from bracket immersion in the test solution revealed no toxicity on U2OS cells using a methylthiazole tetrazolium (MTT) colorimetric assay. Clearly, the search for an improved technique for enhancing the anticorrosion ability of the normal metal orthodontic bracket should be continued.

Cell Line↗

PubMed2002

Effects of heat shock on the thermotolerance, protein composition, and toxin production of Vibrio parahaemolyticus.

Vibrio parahaemolyticus, an important seafood-associated enteropathogen, usually encounters different adverse conditions in its native or food-processing environment, and the stresses resulting from these conditions may affect the survival of this pathogen and thus change its risk with regard to food hygiene. In this study, we investigated the thermotolerance of V. parahaemolyticus under sublethal heat shock and characterized this response by examining the changes in protein profiles and toxin production. Logarithmically grown cells heat shocked at 42 degrees C for 30 min were more resistant to thermal inactivation at 47 degrees C than were unshocked cells. After the 25 degrees C culture was heat shocked, 24 species of proteins were induced, while 13 species were inhibited, as indicated by polyacrylamide gel electrophoresis. DnaJ-, GroEL-, and GroES-like proteins with molecular sizes of 47, 62, and 12 kDa, respectively, were detected by immunoblotting with antibodies raised against the Escherichia coli proteins. During 1 to 8 h of heat shock, GroEL-like protein was produced in substantial amounts and was present in the periplasmic and extracellular fractions, while DnaJ- and GroES-like proteins were present mainly in the total cellular fraction. DnaK-like protein was not detected; nevertheless, the presence of the dnaK-like genetic element was revealed by Southern blotting. Production of thermostable direct hemolysin, the major virulence factor in V. parahaemolyticus, was enhanced in the cells heat shocked at 42 degrees C but not in those heat shocked at 37 degrees C.

Adaptation, Physiological↗