Search PubMed⌕ Search

Biomedical subjects

Y C Yang

Publications and source records attributed to Y C Yang.

At least 145 records · Page 8Linked to original sources
PubMed1995

Metabolic and behavioral response in rats treated with amphetamine chronically with and without challenge.

Chronic amphetamine (AMPH) treatment may cause behavioral sensitization in animals and can be used as an animal model of psychosis. The aim of the study was to check the behavioral and metabolic response in this animal model. In rats pretreated with normal saline (NS) or AMPH, with or without AMPH challenge, the [14C]deoxyglucose method was employed to check the metabolic changes in 42 regions. Behavioral testing was performed in rats with the same treatment. The results showed that after challenge with AMPH, glucose utilization was enhanced in most of the regions investigated. However, metabolic enhancement of the AMPH-pretreated group was lower in the caudate nucleus when compared with that of the NS-pretreated group though the stereotypy rating was higher in the former. Dissociation between the metabolic enhancement and behavioral response was noted. Furthermore, more significant differences between the two pretreated conditions of glucose utilization were found with challenge than without challenge. Further evaluation using procedures which include advanced techniques can be applied in further investigation.

Amphetamine↗
PubMed1995

Vecuronium dissolved in normal saline exaggerates pain on intravenous injection.

BACKGROUND: On some anesthetic occasions, many patients complained of pain at the site of injection when vecuronium, dissolved in normal saline, was administered intravenously. The aims of this study was to compare the incidence of pain on i.v. injection of vecuronium either dissolved in normal saline or in a solvent provided by the pharmaceutical manufacturer. METHODS: We studied eighty patients of ASA physical status class I-II undergoing elective surgery under general anesthesia. Patients were arranged randomly to receive intravenous 0.1 mg/kg vecuronium dissolved either in solvent (n = 40) or in normal saline (n = 40) through the catheter indwelling in a vein on the dorsum of hand over 5 seconds. Immediately after injection, a nurse was appointed to score the degree of pain. Induction of anesthesia was accomplished with thiopental and fentanyl 30 seconds after vecuronium administration. RESULTS: Vecuronium dissolved in normal saline induced severe pain more frequently during injection than that dissolved in solvent (27.5% versus 10%). There was no significant difference in pH between these two solutions (3.87 versus 4.08). However, vecuronium dissolved in normal saline showed higher osmolality than that dissolved in solvent (425 +/- 7 mOsm/kg versus 149 +/- 3 mOsm/kg). CONCLUSIONS: Pain resulting from intravenous injection of vecuronium can be aggravated if normal saline was used as the solvent. Increased osmolality may also be responsible for this phenomenon.

Adult↗
PubMed1995

Cataract surgery by junior ophthalmologists.

The first 50 cases of cataract extraction and lens implant operations performed by seven junior ophthalmologists were retrospectively reviewed to determine whether the surgical outcome of cataract surgery compares with the results of the National Cataract Surgery Survey. Main outcome measures were final visual acuity achieved and the incidences of surgically related complications. In all, 322 case notes were reviewed and full datasets were obtainable in 307 patients (95%). Overall 97% achieved a final visual acuity of 6/12 or better. Twenty per cent had coexisting ocular pathology, 7% had intraoperative complications and 21% had post-operative complications. The visual outcome compared acceptably with the results of the National Cataract Surgery Survey in Britain. The overall incidences of surgically related complications were also acceptable but the rate of vitreous loss was higher and post-operative complications tended to be of greater magnitude.

Cataract Extraction↗
PubMed1994

Regulation of interleukin (IL)-11 gene expression in IL-1 induced primate bone marrow stromal cells.

Interleukin (IL)-1 alpha treatment of a primate bone marrow stromal cell line, PU-34, transiently increased the steady state level of IL-11 mRNA. Nuclear run-on experiments showed that the transcription rate of the IL-11 gene was not affected appreciably by IL-1 alpha induction, but changes in the half-life of the IL-11 mRNA corresponded well with the changes in the steady state level of the IL-11 mRNA during the induction. Although transient transfection of PU-34 cells with IL-11 promoter constructs failed to respond to IL-1 alpha, a 10-base pair promoter region and JunD.AP-1 complex were found to be responsible for the basal level transcription of the IL-11 gene. The tyrosine kinase inhibitor genistein accelerated the degradation of the IL-11 mRNA without affecting the transcription rate of the IL-11 gene in IL-1 alpha stimulated cells. The insertion of DNA sequences corresponding to the 3'-untranslated region of the IL-11 gene into a rabbit beta-globin gene resulted in destabilization of the chimeric mRNA which failed to be induced by IL-1 alpha. Exogenous IL-11 expression generated from transient transfection with plasmid pCMV-IL-11, however, can be stabilized by IL-1 alpha. In contrast to the hypothesis that AUUUA motifs in the 3'-untranslated region are sufficient to regulate cytokine mRNA stability, our results suggest that IL-1 alpha induced stabilization of the IL-11 mRNA requires participation of RNA sequences from different regions of the IL-11 message.

Animals↗
PubMed1994

JAK1 kinase forms complexes with interleukin-4 receptor and 4PS/insulin receptor substrate-1-like protein and is activated by interleukin-4 and interleukin-9 in T lymphocytes.

Interleukin (IL)-4 and IL-9 regulate the proliferation of T lymphocytes through interactions with their receptors. Previous studies have shown that unknown tyrosine kinases are involved in the proliferative signaling triggered by IL-4 and IL-9. Here we show that IL-4 and IL-9 induce overlapping (170, 130, and 125 kilodalton (kDa)) and distinct (45 and 88/90 kDa, respectively) protein tyrosine phosphorylation in T lymphocytes. We further identify the 170-kDa tyrosine-phosphorylated protein as 4PS/insulin receptor substrate-1-like (IRS-1L) protein and 130-kDa protein as JAK1 kinase. Furthermore, we demonstrate for the first time that JAK1 forms complexes with the IL-4 receptor and 4PS/IRS-1L protein following ligand-receptor interaction. In addition, we demonstrate that IL-9, but not IL-4, induced tyrosine phosphorylation of Stat 91 transcriptional factor. The overlapping and distinct protein tyrosine phosphorylation and activation of the same JAK1 kinase in T lymphocytes strongly suggests that IL-4 and IL-9 share the common signal transduction pathways and that the specificity for each cytokine could be achieved through the unique tyrosine-phosphorylated proteins triggered by individual cytokines.

Animals↗
PubMed1994

A new procedure for the purification of the bacteriophage lambda terminase enzyme and its subunits. Properties of gene product A, the large subunit.

New methods for the purification of highly active bacteriophage lambda terminase holoenzyme, and its individual subunits, gene products (gp) A and gpNu1, have been developed. These methods are rapid, simple, reproducible, and give high yields of unaggregated protein from small volumes of culture. The procedures involve fractionation of extracts of Escherichia coli strains harboring plasmids engineered to overproduce the respective proteins. All purified proteins exist as monomers or dimers at moderate concentrations. At concentrations where holoenzyme efficiently promotes in vitro cosN-cleavage and lambda DNA packaging, gpA displays neither of these activities unless supplemented with gpNu1 and the E. coli protein integration host factor. At high protein concentrations, however, gpA can promote cos-cleavage by itself. Although gpNu1 itself cannot promote either cosN-cleavage or DNA packaging, it does modulate these activities of gpA. GpA is a DNA-stimulated ATPase whose catalytic parameters closely resemble those of the holoenzyme. Like the holoenzyme, gpA displays a DNA helicase activity which is able to melt the annealed cosN overhangs. Certain preparations of gpA appear to undergo a time-dependent amino-terminal clipping at discrete sites even in the presence of as many as four protease inhibitors and at low temperature.

Adenosine Triphosphatases↗
PubMed1994

Mitogen-activated protein kinases and ribosomal S6 protein kinases are involved in signaling pathways shared by interleukin-11, interleukin-6, leukemia inhibitory factor, and oncostatin M in mouse 3T3-L1 cells.

The mechanisms of signaling pathways shared by interleukin (IL)-11, IL-6, leukemia inhibitory factor (LIF), and oncostatin M (ONC) remain elusive. We report here that treatment of 3T3-L1 cells with IL-11, IL-6, LIF, and ONC induces overlapping but distinct patterns of tyrosine phosphorylation and activates indistinguishable primary response genes. We further demonstrate for the first time that IL-11, IL-6, LIF, and ONC can trigger the activation of mitogen-activated protein kinases and the 85-92-kDa ribosomal S6 protein kinase (pp90rsk). In addition, our data also show that preincubation of cells with a tyrosine kinase inhibitor herbimycin A, but not with a serine/threonine kinase inhibitor H7, blocks activation of mitogen-activated protein kinases and pp90rsk. Interestingly, H7, but not herbimycin A, inhibits pp90rsk activity in the in vitro kinase assays. These results suggest that pp90rsk is one of the potential candidates for the H7-sensitive protein kinase(s), which is critical for the activation of primary response genes by these cytokines.

3T3 Cells↗
PubMed1994

Histopathological analysis of metastatic melanoma deposits in patients receiving adoptive immunotherapy with tumor-infiltrating lymphocytes.

Tumor-infiltrating lymphocytes (TIL) from a wide range of human and murine tumors can be expanded in vitro using interleukin-2 (IL-2). These TIL are cytolytic T lymphocytes with in vivo and in vitro antitumor activity in mice and in humans. TIL from human melanoma can recognize autologous tumor in an MHC-restricted fashion, localize in vivo after 111In labeling, and mediate regression of large metastatic deposits. Although studied extensively in vitro, less is known in vivo about TIL activity associated with tumor regression. This study was undertaken, in association with a study of TIL localization, to investigate mechanisms of TIL action by evaluating histopathological changes that occur at the tumor site during TIL administration. A total of 106 pre- and post-treatment pathological specimens from 25 patients enrolled in phase II TIL treatment and 111In-TIL imaging protocols were examined blindly by a single pathologist. Histological subtype, lymphocytic infiltration, melanin content, vascularity, and necrosis were documented for each tumor specimen. Average baseline and post-treatment parameters were compared. Any significant changes were evaluated for correlation with clinical response and 111In-TIL localization to tumor. Melanin content and vascularity of the tumor did not change as a result of therapy or correlate with either response or TIL localization. However, both increased lymphocytic infiltration and tumor necrosis were present after TIL administration (P = 0.044 and 0.032 respectively). Furthermore, increases in lymphocytic infiltration correlated with tumor imaging using 111In-TIL, and with the percentage of 111In-labeled injectate present per gram of tumor specimen (P = 0.036 and 0.0041 respectively). This suggests that TIL either account for the increased lymphocytes directly, or localize to tumor and recruit endogenous lymphocytes. We were unable to demonstrate any pretreatment histopathological predictors of response or variables that significantly correlated with subsequent clinical response, although peak and average values of necrosis were higher in responding patients compared to non-responding patients.

Cohort Studies↗
PubMed1994

Activation and tyrosine phosphorylation of 44-kDa mitogen-activated protein kinase (MAPK) induced by electroconvulsive shock in rat hippocampus.

Electroconvulsive shock (ECS) has been reported to induce the phosphorylation and activation of 42-kDa, but not 44-kDa, mitogen-activated protein kinase (MAPK) in rat hippocampus. We studied the activation and tyrosine phosphorylation of MAPKs in rat brain after ECS. We observed the increase of the activities of both 42- and 44-kDa MAPKs in rat hippocampus after ECS. The activities reached peak at 2 min and returned to basal levels by 15 min after ECS. We also observed the increased phosphorylation on the tyrosine residue of 42-kDa MAPK in rat hippocampus after ECS, but not on that of 44-kDa MAPK. However, when we examined the immunoprecipitated 44-kDa MAPK, we could demonstrate that the tyrosine phosphorylation of 44-kDa MAPK at 2 min after ECS was markedly increased, in accordance with the increase of kinase activity. These results indicate that ECS induces the transient activation and tyrosine phosphorylation of 44-kDa MAPK, as well as 42-kDa MAPK, in rat hippocampus, although the amount of tyrosine phosphorylation is far less and the kinase activity is lower in 44-kDa MAPK than in 42-kDa MAPK.

Animals↗
PubMed1994

[Barium-pudding: a new medium for videofluoroscopic examination].

The evaluation of swallowing function is crucial in the management of dysphagic patients. It includes clinical assessment and laboratory tests that consist of fiberoptic endoscopic examination of swallowing (FEES) and videofluoroscopic examination. The "modified barium swallow" has been regarded as the standard procedure of videofluoroscopic examination since its introduction in 1983. The technique enables the entire process of deglutition to be observed with the benefits of safety, easily performance, and information. However, pitfalls developed in patients with pseudobulbar paralysis. Discrepancy always occurs between barium meals and real food and the refusal of swallow and misswallowing to the airway in videofluoroscopic examination sometimes occurs because of the unsatisfactory taste of barium meal. All these things make the procedure impractical and inaccurate. We developed a barium sulfate pudding that is better tasting, similar to real food as a pudding, is adequate to visualise on videofluoroscopic examination, and has the ability to represent the patient's capacity to swallow solid food. We present a case of hypoxic encephalopathy where the patient was considered to be in danger of aspiration when swallowing any consistency of foods. Barium-pudding study showed the patient had the ability to eat solid food with safety. We removed her nasogastric tube following barium-pudding assessment and successfully restored her oral feeding function within 2 weeks. Barium-Pudding is a better medium of videofluoroscopic examination by which to evaluate the swallowing function of solid food than Barium paste in patient, who have disturbed swallowing.

Aged↗
PubMed1994

Cardiovascular collapse during gynecologic laparoscopy complicated by pulmonary edema: report of a case.

Although gynecologic laparoscopic surgery has recently become a routine and widespread operative procedure in Taiwan, the potential risks and complications in the clinical practice of laparoscopy should not be overlooked. Whilst the incidence of complications are rare, they can sometimes be serious, even life-threatening. This case report presents a woman with ruptured endometrioma, who developed sudden-onset cardiovascular collapse during laparoscopic procedure, in which carbon dioxide was used for insufflation. After resuscitation including cardioversion, her vital functions were restored; pulmonary edema developed soon afterwards but was resolved with conservative treatment. We discuss the possible causes of cardiovascular collapse during laparoscopic procedure and the management of resulting complications.

Adult↗
PubMed1994

[Family influence on cancer screening participation in seven communities in Taiwan].

Cancer is the leading cause of death in Taiwan. Since there is no definitive method for cancer prevention, early detection play a major role in fighting cancer. Factors that affect people's willingness to participate cancer screening have been discussed widely except for those relating to the family. The family's role in motivation & influencing its members to participate in an invited cancer-screening program was studied in seven Taiwanese communities. 5% of participants in each area for both genders were chosen by stratified random sampling, and matched with teice-informed nonparticipants who were chosen by sex, age, and neighborhood. By means of a home visit and structured questionnaire, 729 of the 987 eligible cases were interviewed (73.9%). The main findings were that the response was higher among people with higher education, nonsmokers, and those who felt the scheduled time and place of attendance was suitable and convenient. Moreover, in the 6 variables related to family (family structure, family life cycle, cancer history in family and friends, family APGAR, family support about health problems, and family's opinion about cancer screening), the last 4 variables were found to be significantly related by chi-square analysis to the attendance. Finally, a logistic regression analysis adjusted by age, sex, education, smoking habits, time available and traffic factors was used to analyze how family factors affect attendance. The result was cancer history in family and friends (odd ratio = 2.42) and family's encouragement (odd ratio = 1.85) had a positive association.

Adult↗
PubMed1994

[Evaluation of yellow IRIS/model 450 for routine urinalysis].

BACKGROUND: Urinalysis yields a great deal of information quickly and economically for detection of renal diseases. The inter-technician variation and time consuming are major problems while processing large amount of specimens. The purpose of this study is to evaluate the benefit of an automated urine analyzer, Yellow IRIS/model 450, and the feasibility of replacing the currently-used manual KOVA method. METHODS: A total of 1,000 random urine specimens were analyzed with Yellow IRIS and KOVA method. Precision, correlation, and detection rate of abnormality were compared between these two methods. RESULTS: The results revealed that Yellow IRIS had high precision with little between-run and within-run variation, while the obtained values were notably highly correlated with the expected values (r = 0.99). In addition, detection rate of blood cell abnormalities for the Yellow IRIS was twice better than for the manual KOVA method. CONCLUSIONS: The high precision of the machine, the simple procedure of performing, and the quickness of obtaining data, can minimize variability caused by the manual method and save processing time for mass screening. It is feasible to replace the manual urinalysis by the automated urine analyzer Yellow IRIS. Nevertheless, to minimize the extent of manual manipulation, including pouring the urine into the pour cup, and placement of the urine strip, will assist in a wider acceptance for the Yellow IRIS/Model 450.

Autoanalysis↗
PubMed1994

Identification of a 130-kilodalton tyrosine-phosphorylated protein induced by interleukin-11 as JAK2 tyrosine kinase, which associates with gp130 signal transducer.

Interleukin-11 (IL-11) shares the common signal transducer gp130 with IL-6, leukemia inhibitory factor (LIF), and oncostatin M (OSM) and triggers activation of unknown tyrosine kinases as the early steps of signal transduction pathway. Here we identify a 130-kilodalton tyrosine-phosphorylated protein induced by IL-11 in 3T3-L1 cells as JAK2 tyrosine kinase. We further show that the in vitro kinase activity of JAK2 is greatly enhanced following stimulation with IL-11 in 3T3-L1 cells and TF-1 cells. Furthermore, we demonstrate that JAK2 physically associates with the signal transducer gp130. Similar results were observed following stimulation with IL-6, LIF, and OSM. However, we were unable to show that JAK1 is tyrosine phosphorylated and activated by IL-11 under identical conditions. These results suggest that JAK2 tyrosine kinase is one of the tyrosine kinases involved in signal transduction mediated by IL-11, IL-6, LIF, and OSM.

Antigens, CD↗
PubMed1993

Establishment and characterization of an HTLV-I cell line from a Taiwanese patient with HTLV-I-associated myelopathy.

We describe a Taiwanese woman with chronic progressive myelopathy, in whom Western blot analysis of the serum and cerebrospinal fluid (CSF) displayed positive reactions to human T-lymphotropic virus type I (HTLV-I) proteins, p19, p24, p28, p36, gp46 and p53. HTLV-I proviral genomes were detected in the peripheral blood mononuclear cells (PBMC) and CSF cells by nested polymerase chain reaction and Southern blot hybridization. HTLV-I was successfully isolated from PBMC stimulated with interleukin-2 (IL-2). The established cell line, named THAM-1, was an IL-2-independent T-cell line with CD2+, CD3+, CD4+, CD25+ and HLA-DR+. Retrovirus particles with type C morphology were observed in the THAM-1 cells by electron microscopy, and HTLV-I-related antigens were also demonstrated by immunocytochemical staining and Western blot assay. Southern blot analysis revealed that HTLV-I proviral genomes were integrated into the THAM-1 cellular DNA. In Northern blot analysis, two extra-species of RNA were detected in addition to three typical viral transcripts. For the first time, an HTLV-I-producing T cell line was established from a patient with HTLV-I-associated myelopathy in Taiwan, an HTLV-I non-endemic area.

Adult↗
PubMed1993

Effects of osmotic stress and growth stage on cellular pH and polyphosphate metabolism in Neurospora crassa as studied by 31P nuclear magnetic resonance spectroscopy.

High-resolution 31P-NMR was employed to investigate the effects of growth stage and environmental osmolarity on changes of polyphosphate metabolism and intracellular pH in intact Neurospora crassa cells. Our study showed that changes of these parameters were growth-dependent. The ratio of polyphosphate to orthophosphate in vacuoles increased from 2.4 to 13.5 in N. crassa as cells grew from early log phase to stationary phase. Cytoplasmic pH and vacuolar pH changed, respectively, from 6.91 and 6.49 in early log phase cells to 7.25 and 6.84 in stationary phase cells. Hypoosmotic shock of N. crassa produced growth-dependent changes including: (i) a rapid hydrolysis of polyphosphate with a concomitant increase in the concentration of the cytoplasmic phosphate, (ii) an increase in cytoplasmic pH, and (iii) an increase in vacuolar pH. Early log phase cells produced the most dramatic response whereas the stationary phase cells appeared to be recalcitrant to the osmotic stress. Thus, 95% and 60% of polyphosphate in the early log phase and mid-log phase cells, respectively, disappeared in response to hypoosmotic shock, but little or no hydrolysis of polyphosphate occurred in stationary cells. The cytoplasmic pH and the vacuolar pH increased in response to hypoosmotic shock by 0.4 and 0.53 unit, respectively, in early log phase cells; and by 0.22 and 0.27 unit, respectively, in the mid-log phase cells. In contrast, hypoosmotic shock of the stationary phase cells did not cause any change in intracellular pH. The osmotic stress-induced polyphosphate hydrolysis and pH changes in early log and mid-log phase cells were reversible, suggesting that these changes were related environment osmolarity. Addition of polyamines or basic amino acids which are known to be sequestered in vacuoles did not effect polyphosphate metabolism.

Amino Acids↗
PubMed1993

Involvement of IL-6 signal transducer gp130 in IL-11-mediated signal transduction.

IL-11 is a novel cytokine with a variety of biofunctions which overlap with those of IL-6. We have previously identified IL-11 specific binding protein which is distinct from that of IL-6 in a number of cell lines. The similarities in biofunctions and differences in ligand binding proteins between IL-11 and IL-6 prompted us to investigate whether IL-11 shares common signal transduction mechanisms with IL-6. We have examined early signals triggered by IL-11 or IL-6 in a multifactor-dependent human erythroleukemic cell line, TF-1. The results showed that IL-11 and IL-6 can both stimulate cell proliferation, induce similar pattern of protein tyrosine phosphorylation, and activate the same proto-oncogene (junB) expression in TF-1 cells. These findings imply that IL-11 and IL-6 share similar early signaling events with the possibility of using the same signal transducer, gp130. We next tested whether IL-11 induced signaling can be inhibited by anti-gp130 antibodies which blocked IL-6-mediated functions. It was observed that anti-gp130 antibodies abolished cell proliferation, protein tyrosine phosphorylation, and junB gene expression elicited by IL-11 or IL-6 in TF-1 cells. The same antibodies, however, had no effect on granulocyte-macrophage colony stimulating factor or erythropoietin-induced TF-1 cell proliferation. Finally, anti-IL-6R antibody inhibited the ability of IL-6, but not IL-11, to transduce early signals in TF-1 cells. These results demonstrate that IL-11 and IL-6 utilize different ligand binding proteins, but share common signal transducer, gp130, in TF-1 cells.

Animals↗