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Biomedical subjects

Y-C Huang

Publications and source records attributed to Y-C Huang.

12 recordsLinked to original sources

Spinal epidural Rosai-Dorfman disease preceding by relapsing uveitis: a case report with literature review.

STUDY DESIGN: Case report. SETTING: Tertiary referral center hospital in Taiwan. OBJECTIVES: To report a case of spinal Rosai-Dorfman disease (RDD) presenting with paraparesis and also preceding by relapsing uveitis for 6 months. A thoracic laminectomy was performed to remove the solid mass. The pathological diagnosis reveals infiltrating histiocytes, emperipolesis and positivity for S-100. There is no recurrence 1 year later with MR imaging. CONCLUSIONS: The relapsing idiopathic uveitis may be a prodrome for this unusual disease, because RDD is associated closely to defective immunogical response. Early and accurate diagnosis of CNS RDD may reverse the neurologic deficits by early decompression.

Epidural Space↗

Vitamin B6 supplementation increases immune responses in critically ill patients.

OBJECTIVE: To investigate whether vitamin B6 supplementation has a beneficial effect on immune responses in critically ill patients. DESIGN: A single-blind intervention study. SETTING: The study was performed at the Taichung Veterans General Hospital, the central part of Taiwan. SUBJECTS: Fifty-one subjects who stayed over 14 days in the intensive care unit completed the study. Subjects were not treated with any vitamin supplement before the intervention. INTERVENTIONS: Patients were randomly assigned to one of three groups, control (n = 20), a daily injection of 50 mg vitamin B-6 (B6 -50, n=15), or 100 mg vitamin B-6 (B6 -100, n = 16) for 14 days. MAIN OUTCOME MEASURES: Plasma pyridoxal 5'-phosphate (PLP), pyridoxal (PL), 4-pyridoxic acid (4-PA), erythrocyte alanine (EALT-AC) and aspartate (EAST-AC) aminotransaminase activity coefficient, and urinary 4-PA were measured. The levels of serum albumin, hemoglobin, hematocrit, high-sensitivity C-reactive protein (hs-CRP) and immune responses (white blood cell, neutrophils, total lymphocytes count (TLC), T- (CD3) and B-(CD19) lymphocytes, T-helper (CD4) and suppressor (CD8) cells) were determined. RESULTS: Plasma PLP, PL, 4-PA and urinary 4-PA concentrations significantly increased in two treated groups. T-lymphocyte and T-helper cell numbers and the percentage of T-suppressor cell significantly increased on day 14 in the B6 -50 group. Total lymphocyte count, T-helper and T-suppressor cell numbers, the percentage of T-lymphocyte cells and T-suppressors significantly increased in the B6 -100 group at the 14th day. There were no significant changes with respect to immune responses in the control group over 14 days. CONCLUSIONS: A large dose of vitamin B6 supplementation (50 or 100 mg/day) could compensate for the lack of responsiveness of plasma PLP to vitamin B6 intake, and further increase immune response of critically ill patients. SPONSORSHIP: This study was supported by the National Science Council, Taiwan, Republic of China (NSC-92-2320-B-040-026).

APACHE↗

Bone regeneration in a rat cranial defect with delivery of PEI-condensed plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4).

Gene therapy approaches to bone tissue engineering have been widely explored. While localized delivery of plasmid DNA encoding for osteogenic factors is attractive for promoting bone regeneration, the low transfection efficiency inherent with plasmid delivery may limit this approach. We hypothesized that this limitation could be overcome by condensing plasmid DNA with nonviral vectors such as poly(ethylenimine) (PEI), and delivering the plasmid DNA in a sustained and localized manner from poly(lactic-co-glycolic acid) (PLGA) scaffolds. To address this possibility, scaffolds delivering plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4) were implanted into a cranial critical-sized defect for time periods up to 15 weeks. The control conditions included no scaffold (defect left empty), blank scaffolds (no delivered DNA), and scaffolds encapsulating plasmid DNA (non-condensed). Histological and microcomputed tomography analysis of the defect sites over time demonstrated that bone regeneration was significant at the defect edges and within the defect site when scaffolds encapsulating condensed DNA were placed in the defect. In contrast, bone formation was mainly confined to the defect edges within scaffolds encapsulating plasmid DNA, and when blank scaffolds were used to fill the defect. Histomorphometric analysis revealed a significant increase in total bone formation (at least 4.5-fold) within scaffolds incorporating condensed DNA, relative to blank scaffolds and scaffolds incorporating uncondensed DNA at each time point. In addition, there was a significant increase both in osteoid and mineralized tissue density within scaffolds incorporating condensed DNA, when compared with blank scaffolds and scaffolds incorporating uncondensed DNA, suggesting that delivery of condensed DNA led to more complete mineralized tissue regeneration within the defect area. This study demonstrated that the scaffold delivery system encapsulating PEI-condensed DNA encoding for BMP-4 was capable of enhancing bone formation and may find applications in other tissue types.

Animals↗

Genotyping analysis of colonizing candidal isolates from very-low-birthweight infants in a neonatal intensive care unit.

To analyse the relatedness of colonizing candidal isolates from very-low-birthweight infants hospitalized in a neonatal intensive care unit (NICU), we prospectively collected 86 candidal isolates from 20 infants, including 67 isolates of Candida albicans from 15 infants, 17 isolates of Candida parapsilosis from five infants and two isolates of Candida glabrata from one infant, who also had C. albicans colonization, over a one-year period. All 86 isolates were genotyped by infrequent-restriction-site polymerase chain reaction (IRS-PCR) and electrophoretic karyotyping (EK) with pulsed-field gel electrophoresis. A total of 15 genotypes were identified by IRS-PCR and 12 genotypes by EK. Some infants shared a common genotype. From a single infant, an identical genotype was found in 11 of 13 cases where at least two isolates of same Candida species were available for genotyping analysis, regardless of anatomical site, how many isolates were recovered or how many times. Should an infant harbour a candidal strain, they may harbour this strain at multiple sites and for a prolonged period.

Candida↗

Folic acid and vitamin B12 are more effective than vitamin B6 in lowering fasting plasma homocysteine concentration in patients with coronary artery disease.

OBJECTIVE: To investigate whether vitamin B(6) supplementation had a beneficial effect on lowering fasting plasma homocysteine concentrations in coronary artery disease (CAD) patients. DESIGN: A single-blind intervention study. SETTING: The study was performed at the Taichung Veterans General Hospital, the central part of Taiwan. SUBJECTS: A total of 50 subjects were identified by cardiac catheterization to have at least 70% stenosis of one major coronary artery. In all, 42 patients successfully completed this study. INTERVENTIONS: Patients were randomly assigned to one of five groups and treated with a daily dose of placebo (n=8), 5 mg vitamin B(6) (n=8), 10 mg vitamin B(6) (n=8), 50 mg vitamin B(6) (n=9), or 5 mg folic acid combined with 0.25 mg vitamin B(12) (n=9) for 12 weeks. MAIN OUTCOME MEASURES: Nutrient intakes were recorded by using 24-h diet recalls when patients returned to the cardiology clinic before the intervention (week 0) and at week 12. Vitamin B(6) status was assessed by direct measures (plasma pyridoxal 5'-phosphate) and indirect measures (erythrocyte alanine and aspartate aminotransaminase activity coefficient). Fasting plasma homocysteine, serum folic acid, and vitamin B(12) were measured. RESULTS: Fasting plasma homocysteine concentration did not respond to high or low doses of vitamin B(6) when compared with a placebo treatment after 12 weeks of supplementation. The mean fasting plasma homocysteine concentration, however, decreased significantly after 12 weeks of folic acid combined with vitamin B(12) supplementation (P=0.047). Further, within group, mean fasting plasma homocysteine concentration was nonsignificantly increased by 25.5, 16.2, and 18.3% in placebo, 10 mg/day and 50 mg/day vitamin B(6) supplemented groups, respectively; whereas folic acid combined with vitamin B(12) supplementation significantly reduced fasting plasma homocysteine concentration by 32% (P<0.001). CONCLUSIONS: Our results indicate that vitamin B(6) supplementation alone is less effective than folic acid combined with vitamin B(12) in lowering plasma homocysteine concentrations in CAD patients. SPONSORSHIP: This study was supported by the National Science Council, Taiwan, Republic of China (NSC-91-2320-B-040-023).

Adult↗

Invasive pneumococcal infections: a clinical and microbiological analysis of 53 patients in Taiwan.

OBJECTIVE: To track penicillin susceptibility among Streptococcus pneumoniae causing invasive diseases and to evaluate risk factors for antibiotic resistance. METHODS: A retrospective study was performed in a medical center of all patients with invasive pneumococcal infections based on positive microbiological findings, confirmed by appropriate clinical and laboratory findings. MICs of penicillin and ceftriaxone were determined and interpreted by NCCLS methodology. RESULTS: Fifty-three episodes of invasive S. pneumoniae infections (ISPI) among 22 children and 31 adults were identified. The disease patterns of ISPI were similar between children and adults, and the most common modes were pneumonia (70%) and primary bacteremia (23%). The rate of penicillin-nonsusceptible S. pneumoniae (PNSP) isolated from pediatric patients was higher than that in adult patients (95.5% vs. 54.8%, P < 0.001). This finding was correlated to prior antibiotic use that was more common in children (36.4%) than in adults (18.9%). The rate of penicillin-resistance among S. pneumoniae isolates (PRSP) was extremely high in this area: 45.5% from pediatric patients and 41.9% from adult patients. More adults (90.3%) with ISPI had major underlying diseases than children (4.5%). This may explain why adult patients tended to run an unfavorable outcome (mortality rate, 51.6% and 4.5% in adults and children, respectively), although most of the cases with empyema were children. None of the patients enrolled in this study received pneumococcal vaccination. CONCLUSION: We suggest that vaccines be administered for young children and the elderly with major underlying diseases to prevent ISPI.

Adolescent↗

Comparison of nitric oxide production and motion characteristics after 3-layer percoll and IxaPrep preparation methods of human sperm.

OBJECTIVE: To compare two different spermatozoa preparation mediums, the three-layer Percoll (Sigma, St. Louis, MO; salica-based) and the IxaPrep (Medicult, Copenhagen, Denmark; non-salica based, polysucrose medium) method, with respect to recovery of pregressive motile sperm and various sperm motion characteristics. Analysis was determined by computer-aided sperm analysis and nitric oxide (NO) production of the supernatant after centrifugation. METHOD: Thirty-nine semen specimens were obtained from men who presented for semen analysis and each of them was divided into two aliquots for preparation with the two mediums mentioned above. The motile sperm recovery, motility percentage and motion parameters were measured for each semen specimen (n=39) before and after preparation using one of the two above methods. The NO was measured using the chemiluminscence method after centrifugation. RESULTS: Recovery rate was higher in the IxaPrep group (Ixaprep: 45.4+/-28.7% versus Percoll: 32.3+/-22.7%; p<0.05). The other motion characteristics such as average path velocity (VAP) and straight line velocity (VSL) were better than those of fresh semen samples [VAP: 72+/-17.2 micro m/s (Percoll), 62.8+/-18.2 micro m/s (Ixaprep) vs 52.2+/-9.5 micro m/s (fresh); p<0.05; VSL: 51.8+/-13.4 micro m/s (Percoll), 44.8+/-12.9 micro m/s (Ixaprep) vs 38.6+/-7.9 micro m/s (fresh); p<0.05]. The motility between fresh and post-preparation semen samples had no significant difference. Hyperactivation of the sperm was improved in the IxaPrep group compared with fresh sperm (Percoll: 24.7+/-16.9% and IxaPrep: 20.5+/-10.5% versus fresh: 9.2+/-9.2%; p<0.05). NO produced in the IxaPrep method was significantly lower than that in the Percoll method (Ixaprep: 0.24+/-0.3 micro M versus Percoll: 0.54+/-0.91 micro M; p<0.05). CONCLUSION: Our data suggests that the IxaPrep method provides a better recovery rate, but that other motion characteristics did not demonstrate any significant difference. The lower level of NO produced in the IxaPrep preparation method may suggest that better sperm quality achieved is due to the decreased NO production.

Cell Separation↗

Vitamin B6 intakes and status of mechanically ventilated critically ill patients in Taiwan.

OBJECTIVE: To assess vitamin B6 intake and status of critically ill patients. The relationship between vitamin B6 status indicators and the severity of illness and outcome in these patients was also examined. DESIGN: Prospective clinical study. SETTING: The study was performed at the Taichung Veteran General Hospital, in the central part of Taiwan. SUBJECTS: Ninety-four patients in the intensive care unit (ICU) entered the study and 46 patients successfully completed this study. INTERVENTIONS: No intervention. MAIN OUTCOME MEASURES: Vitamin B6 intake was recorded for 14 days. Vitamin B6 status was assessed by direct measures (plasma pyridoxal 5'-phosphate (PLP), pyridoxal (PL), and urinary 4-pyridoxic acid (4-PA)) and indirect measures (erythrocyte alanine (EALT-AC) and aspartate (EAST-AC) aminotransaminase activity coefficient). The severity of illness (APACHE II score), the length of ventilation dependency, and the length of ICU and hospital stay were recorded. RESULTS: Patients had an adequate mean vitamin B6 intake (16.26+/-19.39 mg) during the 14 day study. Mean vitamin B6 intake was significantly higher on day 14 than on day 1 (P<0.001). However, plasma PLP and PL concentrations significantly decreased at the 14th day after admission (P<0.05). Erythrocyte alanine aminotransaminase activity coefficient and EAST-AC did not change significantly. Urinary 4-PA significantly increased at the 14th day (P<0.001). No significant relationships were found between APACHE II scores and clinical outcomes (the length of ICU and hospital stay, the length of ventilation dependency) of patients, vitamin B6 intake or status indicators. CONCLUSIONS: Critically ill patients received nutritional support in the ICU, and had sufficient mean vitamin B6 intake and adequate vitamin B6 status. Therefore, the severity of illness and the results should not be affected by vitamin B6 status. However, we have noted that plasma PLP and PL concentrations significantly decreased while vitamin B6 intake significantly increased on day 14. Critical clinical conditions and complex metabolism in the critically ill may account for the reduction of plasma PLP and PL. Since vitamin B6 deficiency causes profound effects on immune system function, dietary or supplemented vitamin B6 intake is suggested for hospitalized patients.

APACHE↗

Measured versus estimated energy expenditure in mechanically ventilated critically ill patients.

Accurate determination of energy expenditure is essential in patients receiving nutritional support to meet metabolic needs. The purpose of this study was to assess and compare the energy expenditure as measured by indirect calorimetry (MEE) and estimated by 5 equations in the mechanically ventilated critically ill patients. Forty-six patients were divided into either enteral nutrition (EN) (n=l2), total parenteral nutrition (TPN) (n=16) or combined (EN plus TPN) (n=l8) groups. Patients' energy expenditure was measured by indirect calorimetry on two occasions. Anthropometric and biochemical measurements, energy expenditure and medical status (APACHE II score) were also assessed in the intensive care unit (ICU) of Taichung Veteran General hospital. No significant difference was found in the MEE among the 3 groups. The type of nutritional support did not affect MEE. Energy expenditure calculated by using Harris- Benedict, Kleiber and Liu equations times the estimated stress factor did not significantly different than the values of MEE in all groups. There were significant correlations (P<0.01) between MEE and patients' sex (r=-0.499), age (r=-0.402), height (r=0.533), knee height (r=0.431), current body weight (r=0.379), usual body weight (r=0.407), ideal body weight (r=0.466) and urinary urea nitrogen (r=0.383) in the pooled group. Results demonstrated that energy expenditure could be estimated in most critically ill patients by using Harris-Benedict, Kleiber and Liu equations if the estimated stress factor is in the reasonable value.

Aged↗

Comparison of nitric oxide production motion characteristics of sperm after cryopreserved in three different preparations.

Three ml of semen collected from 20 volunteers were divided into three aliquots: a) semen cryopreserved for 48 hr then swim-up method; b) using swim-up method then cryopreserving for 48 h; and c) using 45%-90% two layers PureSperm to prepare sperm then cryopreserved for 48 h. Motility characteristics were evaluated before cryopreservation and after thawing. NO was measured using the chemiluminescence method after centrifugation. The recovery rate and motion parameters were the highest in the swim-up group. NO produced in the swim-up group was significantly lower than the PureSperm group, and the PureSperm group was lower than the semen treated with cryoprotectant group. Best semen quality was achieved due to the decreased NO production.

Cryopreservation↗

The characteristics of betamethasone-loaded chitosan microparticles by spray-drying method.

Betamethasone (BTM)-loaded microparticles prepared by a spray drying method using chitosan (CTS) as raw material, type-A gelatin and ethylene oxide-propylene oxide block copolymer (Pluronic F68) as modifiers. The BTM-loaded in varied chitosan/Pluronic F68/gelatin microparticle formulations was investigated. By properly choosing excipient type and concentration a high degree of control was achieved over the physical properties of the BTM-loaded microparticles. Microparticle characteristics (zeta potential, tap density, particle size and yield), loading efficiencies, microparticle morphology and in-vitro release properties were examined. Surface morphological characteristics and surface charges of prepared microparticles were observed by using scanning electron microscopy (SEM) and microelectrophoresis. A SEM micrograph shows that the particle sizes of the varied chitosan composed microparticles ranged from 1.1-4.7 microm and the external surfaces appear smooth. The BTM-loaded microparticles entrapped in the chitosan/Pluronic F68/gelatin microparticles with trapping efficiencies up to 93%, collected yield rate 44%, and mean particle size varied between 1-3 microm, positive surface charge (20-40 mv), and tap densities (0.04-0.40 g/cm3) were obtained. The collected BTM yield and size of particle was increased with increasing BTM-loaded amount but both zeta potential and tap density of the particles decreased with increasing BTM-loaded amount. The in vitro release of BTM showed a dose-dependent burst followed by a slower release phase that was proportional to the drug concentration in the concentration range between 5-30%w/w. The in vitro drug release from the chitosan/Pluronic F68/gelatin 1/0.1/0.4 microspheres had a prolong release pattern. These formulation factors were correlated to particulate characteristics for optimizing BTM microspheres in pulmonary delivery.

Anti-Inflammatory Agents↗

Optimizing formulation factors in preparing chitosan microparticles by spray-drying method.

The chitosan only, chitosan/Pluronic F68, chitosan/gelatin, chitosan/Pluronic F68/gelatin microparticles and betamethasone-loaded chitosan/Pluronic F68/gelatin microparticles were successfully prepared by a spray-drying method. Microparticle characteristics (yield rate, zeta potential, particle size and tap density), loading efficiencies, microparticle morphology and in-vitro release properties were investigated. By properly choosing excipient type, concentration and varying the spray-drying parameters, a high degree of control was achieved over the physical properties of the dry chitosan powders. SEM micrograph shows that the particle sizes of the varied chitosan composed microparticles ranged from 2.12-5.67 microm and the external surfaces appear smooth. Using betamethasone as model drug, the spray-drying is a promising way to produce good spherical and smooth surface microparticles with a narrow particle size range for controlled delivery of betamethasone. The positively charged betamethasone-loaded microparticles entrapped in the chitosan/Pluronic F68/gelatin microparticles with trapping efficiencies up to 94.5%, yield rate 42.5% and mean particle size 5.64 microm varied between 4.32-6.20 microm and tap densities 0.128 g/cm(3). The pH of particle was increased with increasing betamethasone-loaded amount, but both zeta potential and tap density of the particles decreased with increasing betamethasone-loaded amount. The betamethasone release rates from chitosan/Pluronic F68/gelatin microparticles were influenced by the drug/polymer ratio in the manner that an increase in the release% and burst release% was observed when the drug loading was decreased. The in vitro release of betamethasone showed a dose-dependent burst followed by a slower release phase that was proportional to the drug concentration in the concentration range between 14-44%w/w.

Betamethasone↗