Biomedical subjects

J W Yang

Publications and source records attributed to J W Yang.

At least 19 recordsLinked to original sources

PubMed2006

Mass spectrometrical analysis of galectin proteins in primary rat cerebellar astrocytes.

Galectins are a family of animal lectins with specificity for beta-galactosides and are involved in a host of cellular activities, ranging from development to cancer. The molecules are expressed by neural and non-neural cells intracellularly as well as extracellularly. Using two-dimensional gel electrophoresis coupled to tandem mass spectrometry, the present work aimed to identify and characterize galectins in primary rat cerebellar astrocytes. The protein-chemical method identified nine spots representing two members of the galectin family, namely galectin-1 and galectin-3. These findings suggest that high abundant expression of galectin in astrocytes is limited to the two abundant galectin family members. As these family members are linked to human astrocytic tumors, their reliable detection in astrocytes by proteomic techniques would enable us to further understand their role in neural development, injury, and regeneration in general and astrocytoma in particular.

Amino Acid Sequence↗

PubMed2006

Current source density analysis of laser heat-evoked intra-cortical field potentials in the primary somatosensory cortex of rats.

The role of the primary somatosensory cortex in thermal pain perception has been established. However, the cortical circuitry that mediates the thermo-nociceptive information processing has not been elucidated. The aim of present study was to investigate the intracortical synaptic currents in primary somatosensory cortex evoked by short laser pulses and to determine their transmission pathway. Noxious CO2 laser pulse stimuli or innocuous electrical and mechanical stimuli were delivered to the hind paw of halothane-anesthetized rats. Multi-channel field potentials were recorded simultaneously in primary somatosensory cortex and laminar-specific transmembrane currents were analyzed using a current source density method. A distinct spatial-temporal pattern of intra-cortical sink source currents was evoked by laser pulse stimuli. The amplitude of the early component was graded by laser energy output and influenced by contralateral signals, whereas the late components were not intensity-dependent and exhibited bilateral excitation. Intra-cortical current flows revealed that synaptic activation occurred initially at layers IV and VI separately and then was relayed transynaptically to the more superficial and the deeper layers. Latency, amplitude and intracortical distributions of the activated intra-cortical currents evoked by noxious stimuli differed significantly from those evoked by innocuous stimuli. Conduction velocity data together with the results of tetrodotoxin, capsaicin and morphine treatments indicated that the early and late components were mediated separately by A-delta and C fibers. Our results suggest that large and small diameter thermal nociceptive afferents generated laminar-specific intracortical synaptic currents in primary somatosensory cortex and that these excitatory synaptic currents were conveyed separately by lateral and medial thalamic nuclei.

Animals↗

PubMed2006

Aberrant expression of cytoskeleton proteins in hippocampus from patients with mesial temporal lobe epilepsy.

Mesial temporal lobe epilepsy (MTLE), the most common form of epilepsy, is characterised by cytoarchitectural abnormalities including neuronal cell loss and reactive gliosis in hippocampus. Determination of aberrant cytoskeleton protein expression by proteomics techniques may help to understand pathomechanism that is still elusive. We searched for differential expression of hippocampal proteins by an analytical method based on two-dimensional gel electrophoresis (2-DE) coupled with mass spectrometry unambiguously identifying 77 proteins analysed in eight control and eight MTLE hippocampi. Proteins were quantified and we observed 18 proteins that were altered in MTLE. Cytoskeleton proteins tubulin alpha-1 chain, beta-tubulin, profilin II, neuronal tropomodulin were significantly reduced and one actin spot was missing, whereas ezrin and vinculin were significantly increased in MTLE. Proteins of several classes as e.g. antioxidant proteins (peroxiredoxins 3 and 6), chaperons (T-complex protein 1-alpha, stress-induced-phosphoprotein 1), signaling protein MAP kinase kinase 1, synaptosomal proteins (synaptotagmin I, alpha-synuclein), NAD-dependent deacetylase sirtuin-2 and 26S protease regulatory subunit 7 protein, neuronal-specific septin 3 were altered in MTLE. Taken together, the findings may represent or lead to cytoskeletal impairment; aberrant antioxidant proteins, chaperons, MAP kinase kinase 1 and NAD-dependent deacetylase sirtuin-2 may have been involved in pathogenetic mechanisms and altered synaptosomal protein expression possibly reflects synaptic impairment in MTLE.

Adult↗

PubMed2005

Clinical and laboratory evaluation of a new specific ELISA for intact proinsulin.

Intact proinsulin is a marker for pancreatic beta-islet cell secretion status, and elevated levels indicate insulin resistance of type 2 diabetic patients with a high diagnostic specificity. Determination of intact proinsulin in fasting morning plasma samples can be used to establish and/or identify the optimal anti-diabetic treatment as well as to monitor a potential protective treatment effect on beta-islet cell dysfunction. For widespread use as a routine marker, simple and reliable assays must become available for measurement in clinical laboratories. This study was performed to evaluate a new ELISA method specific for intact proinsulin determination compared with a commercial chemiluminescence test. Intra-assay imprecision was determined to be 2.4 - 5.5% (inter-assay: 3.2 - 4.3%). A sample cohort derived from non-diabetic healthy subjects (66 female, 29 male, age (median, range): 37 (19-77) years) was used to calculate a reference range for non-diabetic individuals of 1.8 - 11.0 pmol/l. The comparison of samples obtained from 7 diabetic patients (2 female, 5 male, age: 66 (44-72) years) from oral glucose tolerance tests resulted in an excellent correlation between the ELISA and the chemiluminescence assay (r = 0.989; p<0.001). A sample stability investigation with different sample specimens revealed that intact proinsulin is stable for two days at room temperature in EDTA whole blood and heparin whole blood tubes without centrifugation, while serum samples should be centrifuged immediately and frozen to retain intact proinsulin concentrations. As EDTA whole blood is the routine sample specimen for determination of HbA1c, a marker frequently measured in diabetic patients, this finding underlines the practicability of analyzing intact proinsulin from the same blood specimen. In conclusion our study revealed that the new ELISA shows excellent agreement with the commonly used chemiluminescence immunoassay. The ELISA can easily be introduced into routine laboratories and does not require any further specific instrumentation. Our additional finding that intact proinsulin is stable in EDTA whole blood samples, which can be obtained from the routine.sample for HbA1c measurement, is increasing the probability of the acceptance of this marker for routine assessment of beta-cell dysfunction and insulin resistance in type 2 diabetes.

Adult↗

PubMed2004

Aberrant cytosolic acyl-CoA thioester hydrolase in hippocampus of patients with mesial temporal lobe epilepsy.

A series of enzyme alterations has been shown to be associated with several forms of epilepsy, in mesial temporal lobe epilepsy (MTLE), however, information is limited. It was therefore the aim of the study to determine brain enzyme protein expression using a proteomic screening approach. Hippocampi of controls and patients with drug-resistant MTLE were used for evaluation of protein expression. We applied two-dimensional electrophoresis (2-DE) with mass spectrometrical identification and immunoblotting. 2-DE revealed a remarkably decreased spot identified as cytosolic acyl-CoA thioester hydrolase (BACH; EC 3.1.2.2) in patients with MTLE. Western blotting showed absence of bands at 37 kDa in MTLEs using an antibody against mouse BACH and at 140 kDa in MTLEs using anti-rat BACH. This study demonstrates that BACHs were deranged in hippocampus of MTLE patients. This finding may well contribute to the understanding of the still elusive pathomechanisms involved in MTLE.

Adult↗

PubMed2004

Effect of static magnetic fields on the amplitude of action potential in the lateral giant neuron of crayfish.

PURPOSE: To investigate whether exposure to static magnetic field (SMF) affects the passive properties of neurons that mediate tail-flip escape behavior in crayfish. MATERIALS AND METHODS: A permanent magnet was placed under the isolated nerve cord of crayfish to experience SMF at 4.74 to 43.45 mT intensity for various period of time (20 seconds to 3 hours). An intracellular electrode was impaled on the axon of the lateral giant neuron (LG) of the last abdominal ganglion of crayfish to record the evoked action potential (AP) and excitatory postsynaptic potential (EPSP). The amplitudes of evoked AP and EPSPs before and after SMF exposure were measured to study the effect of SMF exposure. RESULTS: The exposure to SMF increased the amplitude of AP in the LG depending upon both the intensity of field and duration of field exposure. The changes in AP by field exposure are likely to be mediated by the increasing level of intracellular Ca2+ in the LG because the chelating of intracellular Ca2+ would block the effects by SMF exposure, while the injection of Ca2+ into the LG could mimic the effects of SMF exposure. SMF exposure also increases the input resistance of the LG membrane. Therefore, the magnitude of the EPSP in LG evoked by electrical shock on the sensory nerves was found to be enhanced after SMF exposure. CONCLUSION: SMF is usually considered to be safe for the biological issues since no electrical current is induced via the Faraday effect. Our results showed that some passive membrane properties of neurons are affected by SMF exposure. The increase in magnitude of evoked AP and EPSP suggests an increase in the sensitivity of the LG neuron. These changes by SMF exposure may not necessarily to be harmful to animals; however, further study is needed to address the biological effects from SMF exposure, especially in nervous systems.

Action Potentials↗

PubMed2004

Simultaneous removal of nitrate and phosphate using cross-flow micellar-enhanced ultrafiltration (MEUF).

The feasibility of cross-flow micellar-enhanced ultrafiltration (MEUF) was investigated to remove nitrate and phosphate simultaneously. At the above critical micelle concentration (CMC), a cationic surfactant added in wastewater forms micelles, which have positive charge on their surface. Anionic contaminants such as nitrate and phosphate can be bound on the micelles by electrostatic interaction, and the micelle-pollutants complex is removed effectively by ultrafiltration. In this study, a cross-flow MEUF system was designed and investigated the feasibility of MEUF for field application. A cationic surfactant, cetylpyridinium chloride (CPC), was used, and the synthetic wastewater was treated by the polyacrylonitrile membranes with molecular weight cut-off (MWCO) of 30,000 Da and 10,000 Da. With the molar ratio of CPC to total pollutants of > 3, > 86% of nitrate and > 91% of phosphate were removed, respectively, and > 97% of CPC was also rejected. The flux was maintained 20-30% of the flux of distilled water. Therefore, it is feasible to remove nitrate and phosphate simultaneously using the cross-flow MEUF system.

Acrylic Resins↗

PubMed2003

Overexpression of transcription factor BACH1 in fetal Down syndrome brain.

There is a series of about 12 transcription factors expressed on chromosome 21. These transcription factors (TFs) are major candidates for playing a pathogenetic role for the abnormal wiring of the brain in fetal Down Syndrome (DS) as approximately 5,000 TFs are developmentally involved in the complex architecture of the human brain. TF derangement in DS has been already reported and we decided to contribute to the problem by studying four TFs encoded on chromosome 21 in fetal DS brain. We used fetal cortex of 8 DS fetuses and 6 controls (females) from the 18-19th week of gestation. Brain homogenates were subject to immunoblotting using goat-anti-BACH1, rabbit anti-heme oxygenase 1 (HO1), rabbit anti-ERG, rabbit anti-RUNX1 and goat anti-SIM2 l. Antibodies against beta-actin were used to normalise cell loss and antibodies against neuron-specific enolase were used to compensate neuronal loss. BACH1 was significantly overexpressed in fetal DS (p < 0.008) as compared to controls whereas RUNX1 and ERG proteins were comparable between groups, and SIM2 l was not detectable in any specimen. BACH1 was even significantly increased in the DS panel when normalised versus the housekeeping protein beta-actin (p < 0.01) or the neuron specific enolase (p < 0.01). HO-1 was found comparable between groups. BACH1, a member of the family of BTB-basic leucine zipper transcription factors, regulates gene expression through the NF-E2 site. More specifically, BACH1 suppresses expression of HO1. Increased BACH1, however, did not lead to decreased HO1, which would have explained oxidative stress observed in fetal DS.

Basic-Leucine Zipper Transcription Factors↗

PubMed2001

Clinical and anatomical factors associated with thalamic dyskinesias.

To define the clinical and anatomical factors associated with dyskinesias following thalamic infarction, we performed neurological examination and three-dimensional brain magnetic resonance imaging for 23 patients with thalamic infarction. We measured the total volumes and the largest diameters of the lesions on axial and coronal images. Using the atlas of human thalamus, we investigated the damaged thalamic nuclei. We compared the means of the volumes and the largest diameters of the lesions, and the frequencies of damaged thalamic nuclei between patients with and without thalamic dyskinesias. Seven (two pseudochoreoathetosis and five dystonia) of the 23 patients with thalamic infarction developed dyskinesias. No specific neurological deficits at the onset of stroke predicted the development of dyskinesias. The mean volume of the lesions of patients with dyskinesias (739 mm(3)) was significantly larger than that of those without dyskiensias (92.9 mm(3)). The means of the largest axial (11.6 mm) and coronal (10.8 mm) diameters were significantly larger in patients with dyskinesias, compared to those (axial, 7.1 mm; coronal, 6.4 mm) of patients without dyskinesias. Patients with dyskinesias had damage in the centromedian (CM) thalamic nucleus more frequently compared to those without dyskinesias. Patients with a large thalamic infarction involving the CM nucleus are more likely to develop dyskinesias.

Adult↗

PubMed2001

The accuracy of segregation of human mini-chromosomes varies in different vertebrate cell lines, correlates with the extent of centromere formation and provides evidence for a trans-acting centromere maintenance activity.

We show that the accuracy of mitotic segregation of three engineered, mapped human mini-chromosomes differs between human, mouse and chicken cell lines. We have studied the cause of these differences by analysing the extent of centromere formation on one mini-chromosome immunocytochemically. In human and chicken cell lines the mini-chromosomes segregate accurately and form centromeres but in one mouse cell line centromere formation is undetectable and mitotic segregation is inaccurate. These results indicate that the centromere is maintained by an activity that functions in trans and varies either in amount or specificity between different cells. Structurally defined mini-chromosomes may allow this activity to be studied.

Animals↗

PubMed2001

Cost-effective monitoring for a soil vapor extraction (SVE) system: a simplified modeling and gas sensor test.

In order to establish cost-effective monitoring strategies for soil vapor extraction (SVE), a simplified model for multi-component mass transfer of a complex liquid mixture in porous media and gas sensor are proposed and experimentally evaluated. The basic task for the cost-effective monitoring of SVE is to decide how to predict the performances of venting systems in terms of the contaminant vapor removal rate and the time required to accomplish the clean-up specification. The method includes classifying of individual components of a complex mixture on the basis of gas chromatographic (GC) profile and treating each resulting group as a pseudo-single compound. BTEX components of gasoline were selected for model input and the remainders were divided into 4 groups based on their GC retention times. The model proposed in this study is capable of predicting with accuracy volatilization behaviors of gasoline components in soil and the gas sensor (FIGARO TGS 823) was tested by GC-FID to toluene and TPH-GRO(Total Petroleum Hydrocarbon-Gasoline Range Organics) gas samples. A VOC gas sensor was developed which recognizes TPH-GRO concentrations between 250 and 50 ppm. The developed gas sensor test and proposed model can be used as a valuable tool for the cost-effective monitoring for SVE systems.

Chromatography, Gas↗

PubMed2001

Impregnation of vancomycin, gentamicin, and cefotaxime in a cement spacer for two-stage cementless reconstruction in infected total hip arthroplasty.

Twenty-two patients with infected total hip arthroplasty were treated with 2-stage arthroplasty, using a cement spacer impregnated with a combination of 3 thermostable antibiotics (vancomycin, gentamicin, and cefotaxime). Initially, implants were removed, and a spacer was inserted. Six to 12 weeks later, the spacer was removed, and the patients underwent reconstruction using cementless components. The patients were followed for an average of 41 months. One patient had a recurrence of infection and was treated with resection arthroplasty. The remaining 21 patients (95%) had no evidence of infection at the final follow-up. We recommend using the combination of these 3 antibiotics in the cement spacer for 2-stage reconstruction in infected hip arthroplasty when the causative organism is not identified in the culture of preoperative aspiration.

Adult↗

PubMed2001

Pigmentary glaucoma.

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Endothelium, Corneal↗

PubMed2001

In vitro model using mouse hepatocytes for study of alcohol stress.

In this study, the effects of ethanol and allyl alcohol on primary mouse hepatocytes were investigated. No cytotoxicity was observed by ethanol treatments, but more toxicity to cells was found in the response to allyl alcohol treatment. The expression of cytochrome P450 2E1 (CYP2E1), phase I enzyme was examined in response to ethanol and allyl alcohol. Both xenobiotics induced CYP2E1 up to 1.5 to approximately 5 fold at the protein level. The effects of insulin on CYP2E1 expression were also measured. Insulin, which has been regarded as an essential hormone for primary hepatocytes, was shown to decrease the level of CYP2E1 protein, and did not affect cell viability. These results on CYP2E1 induction demonstrate that primary mouse hepatocytes, when using ethanol and allyl alcohol as substrates and in insulin-free medium, provide a suitable system for the studies of the role of CYP2E1 in xenobiotic metabolism and toxicity.

Ammonia↗

PubMed2001

Trochanteric rotational osteotomy for osteonecrosis of the femoral head.

The rate of success of transtrochanteric rotational osteotomy for osteonecrosis of the femoral head may be improved if patients are preselected using MRI. We have used three criteria for selection for osteotomy (i) minor collapse of the infarcted area, loss of congruity or the crescent sign, without narrowing of the joint space or acetabular involvement (ii) patients younger than 55 years and with a painful hip (iii) patients with an intact area constituting an arc of more than 120 degrees between the central vertical line of the femoral head and the posterior or anterior margin of the necrotic portion as seen on a midsagittal MRI. Seventeen patients were selected, with a follow-up of more than 42 months. A bone scan four weeks after operation showed adequate perfusion of the proximal segment in all hips. The hip score of Merle d'Aubigné et al improved from 13.5 points before operation to 17.2 points at the latest follow-up. Further collapse of the femoral head did not occur. The use of MRI instead of plain radiographs for the selection of patients has improved the success rate of transtrochanteric rotational osteotomy.

Adolescent↗

PubMed2001

In vitro migratory responses of swine neutrophils to actinobacillus pleuropneumoniae.

Swine neutrophils were quantitatively examined for the direct and indirect migratory responses to Actinobacillus pleuropneumoniae (APP) in vitro and the effects of pseudorabies virus (PrV), frequently co-infecting with APP, were also observed. About 30% of swine neutrophils responded to viable APP, while 3.2% of the neutrophils responded to 0.1% casein which served as the control. The migration of APP was not affected by preincubation of neutrophils with PrV, which inhibited the random migration. When the random migration was normalized to 1, the chemotactic indices for APP, opsonized-APP and casein were 64, 70 and 8.5, respectively. Heat-killed APP or E. coli lipopolysaccharide stimulated the production of interleukin-8 activity by adherent peripheral blood mononuclear cells (PBMC). Preincubation of PBMC with PrV inhibited the production of neutrophil attractant activity when stimulated with heat-killed APP. The results suggested that the direct chemotaxis of neutrophils to viable APP might contribute to early infiltration in Actinobacillus pleuropneumonia, and that PrV might inhibit indirect recruitment of neutrophils to infected lungs by compromising the functions of PBMC.

Actinobacillus pleuropneumoniae↗

PubMed2001

The central conduction time in posterior tibial and pudendal nerve somatosensory evoked potentials.

The somatosensory evoked potentials (SEPs), following stimulation of both the posterior tibial nerve (PTSEP) and pudendal nerve (PNSEP), comprise of the lumbar negative, subcortical and cortical potential. These can be used to assess the long somatosensory pathway, including peripheral, intraspinal and intracranial conduction along the entire length. This study aimed to compare the central conduction time between the PTSEP and the PNSEP, and to investigate the relationship between the intraspinal and intracranial conduction time in the SEP pathway. The SEPs following stimulation of the posterior tibial nerve at the ankle and the pudendal nerve at the shaft of the penis were analyzed in 20 normal male subjects. The central conduction of the PNSEP was found to be slower than that of the PTSEP (p <0.05). This difference is due to a delay in conduction rather than that of intracranial conduction.

Adolescent↗

PubMed2001

[Protective effect of Angelica on ECV(304) from injury induced by hyperlipidemic serum in vitro].

The aim of this article was to examine the protective effect of Chinese traditional medicine Angelica on human umbilical vein endothelial cells (HUVECs, ECV(304)) from injury induced by hyperlipidemic serum (HLS) and to study the underlying mechanisms. Microstructures of HUVECs were observed by a scanning electron microscope. Spectrophotometer and immunocytochemical methods were used to detect the content of NO in the suspension and expression of ICAM-1, TGFbeta(1), bFGF on the cell surface, respectively. After being incubated with HLS for 24 hours, HUVECs exhibited pronounced morphological changes, such as disappearance of microvilli on the endothelial cell (EC) surface, rupture of cell membranes, etc. Expression of ICAM-l and bFGF in ECs was significantly increased, while expression of TGFbeta(1) and the release of NO from ECs were significantly decreased. All these effects of HLS on ECs can be reversed by Angelica significantly. The above effects of Angelica may be related to its anti-atherosclerotic action.

Angelica sinensis↗