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Biomedical subjects

K Y Wang

Publications and source records attributed to K Y Wang.

At least 37 records · Page 2Linked to original sources
PubMed2000

Catheter-induced coronary spasm--a view of mechanical factors and experience with selective left coronary arteriography.

BACKGROUND: Coronary spasm during cardiac catheterization is not unusual. The mechanism of spasm remains uncertain, but is considered to be multifactorial. Many researchers believe that coronary spasm that develops during catheterization is partly spontaneous and partly catheter-induced. Because catheter-induced spasm results from mechanical irritation, we tried to find the iatrogenic factors that predispose patients to coronary spasm during coronary angiography. METHODS: Retrospectively, we reviewed the records of 7,295 patients who underwent coronary angiography at our hospital from June, 1983 to November, 1997; coronary spasm was documented in 30 patients, who became the study group. We randomly selected 41 patients who had normal coronary arteries as the normal control group. After reviewing cine films of coronary angiography, we compared these two groups for several parameters. These parameters included the length and diameter of the left main coronary artery (LMC), the angle between the LMC and the aorta, the angle between the catheter tip and the LMC, whether the catheter tip came into contact with the vascular wall and whether there was vessel wall bulging, catheter size and catheter/LMC ratio. This angiographic data and the demographic features, including age, sex, history of hypertension, diabetes mellitus, smoking, previous myocardial infarction, family history of coronary artery disease, cholesterol and triglyceride levels and chest pain character (exertional or rest pain) were compared between the study patient group and the control group. RESULTS: The results disclosed that larger catheter size (7.1 +/- 0.6 mm vs 6.4 +/- 0.7 mm, p < 0.001), smaller LMC diameter (4.2 +/- 0.9 mm vs 4.9 +/- 1.0 mm, p = 0.004), larger catheter/LMC ratio (0.07 +/- 0.05 vs 0.05 +/- 0.03, p = 0.022), catheter contact with the vessel wall (27/30 vs 20/41, p < 0.001) and vessel bulging (18/30 vs 5/41, p < 0.001) were related to catheter-induced coronary spasm. We found that the catheter tip coming into contact with the vessel wall, vessel wall bulging and catheter/LMC ratio (odds ratio 8.92 x 10(14)) were statistically significant factors predisposing patients to catheter-induced coronary spasm. CONCLUSIONS: Multiple factors contribute to coronary spasm. Of those, mechanical or iatrogenic factors might predispose patients to spasm during coronary catheterization. These facts deserve our attention, because iatrogenically induced spasms may be avoided by meticulously selecting catheters and manipulating them gently.

Adult↗
PubMed2000

Metabolism of the influenza neuraminidase inhibitor prodrug oseltamivir in the rat.

The metabolism of [2-acetyl-(14)C]oseltamivir (GS4104, Ro 64-0796), the prodrug of the novel influenza neuraminidase inhibitor GS4071 (Ro 64-0802), was examined in rats after oral dosing. Intact oseltamivir was observed only in lung and urine, accounting for 37 and 15% of the total radioactivity in these samples, respectively. GS4071 was the major metabolite in plasma, tissues, and urine, and accounted for 32 to 56% of the radioactivity present in these samples. The second most abundant peak in these samples (13-24% of radioactivity) was a novel metabolite (M3). This metabolite was purified from urine of rats dosed orally with oseltamivir and was identified by liquid chromatography-mass spectrometry and NMR as the (R)-omega-carboxylic acid metabolite of oseltamivir. The omega-carboxylic acid metabolite of oseltamivir could not be produced in vitro. However, omega-hydroxylated products of oseltamivir were produced by rat liver microsomes. Both the (R)- and (S)-omega-hydroxylated products were observed, but formation of the (R)-isomer predominated. These data indicated that in the rat, oseltamivir was primarily metabolized to the active influenza neuraminidase inhibitor GS4071 and, to a lesser extent, to an (R)-omega-carboxylic acid metabolite.

Acetamides↗
PubMed1999

Analysis of 8-aminonaphthalene-1,3,6-trisulfonate-derivatized oligosaccharides by capillary electrophoresis-electrospray ionization quadrupole ion trap mass spectrometry.

Dextran was partially hydrolyzed with 0.1 mol/l HCl and the hydrolysate was derivatized with 8-aminonaphthalene-1,3,6-trisulfonate (ANTS) by reductive amination. The derivatized-oligosaccharide mixture was separated by capillary electrophoresis (CE) in a buffer of 1% HAc-NH4OH, pH 3.4, and the separated components were detected on-line by electrospray ionization quadrupole ion trap mass spectrometry (ESI-QIT-MS) in the negative ion mode. A mass accuracy lower than 0.01% could be achieved and as low as 1.6 pmol of detxran octaose could be detected. ANTS-derivatized dextran oligosaccharide with a degree of polymerization (DP) lower than 6 produced both [M-H]- and [M-2H]2- ions, whereas those with a DP of 6 or higher than 6 produced only [M-2H]2- ion. As 1< or =DP< or =6, the percentage of [M-2H]2- ion in the total ions of [M-H]- and [M-2H]2- was found to be a linear function of the logarithmic DP. Molecular mass determination with ESI-QIT-MS strengthens the power of CE analysis of oligosaccharides.

Electrophoresis, Capillary↗
PubMed1999

Cloning of a galactose-binding lectin from the venom of Trimeresurus stejnegeri.

A galactose-binding lectin isolated from the venom of Trimeresurus stejnegeri is a homodimer C-type lectin. The cloned cDNA encoding the monomer of Trimeresurus stejnegeri lectin (TSL) was sequenced and found to contain a 5'-end non-coding region, a sequence which encodes 135 amino acids, including a typical 23 amino acid signal peptide followed by the mature protein sequence, a 3'-end non-coding region, a polyadenylation signal, and a poly(A) region. To completely characterize the deduced amino acid sequence, on-line HPLC-MS and tandem MS were used to analyse the intact monomer and its proteolytic peptides. A modified peptide fragment was also putatively identified by HPLC-MS analysis. The deduced amino acid sequence was found to contain a carbohydrate-recognition domain homologous with those of some known C-type animal lectins. Thus TSL belongs to group VII of the C-type animal lectins as classified by Drickamer [(1993) Prog. Nucleic Acid Res. Mol. Biol. 45, 207-232]. At present, a number of C-type lectins have been purified from snake venom, but most of them have been characterized only at the protein level. To our knowledge, this is the first known cDNA sequence of a true C-type lectin from snake venom.

Amino Acid Sequence↗
PubMed1999

Comparative study on the distribution of ovalbumin glycoforms by capillary electrophoresis.

Two commercial turkey egg ovalbumins (TEOs) with different quantities of mannose, were further purified by reversed-phase high-performance liquid chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis for either of the purified glycoproteins showed one big wide band and one close small band. Capillary electrophoresis was used for the investigation of the separation of glycoforms of both glycoproteins. The best resolution of the glycoforms was obtained, reproducibly, with 100 mM borate, 1.8 mM 1,4-diaminobutane and pH 8.6 electrophoretic buffer. At least 13 glycoform peaks could be separated for either of the two glycoproteins. Their glycoform patterns were highly similar except for the conspicuous decrease in quantity of four glycoforms in the ovalbumin containing less mannose, compared to that of the other with more mannose. Coinjection electrophoresis of the two glycoproteins indicated that almost every glycoform peak of the former exactly overlapped with its corresponding glycoform peak of the latter. These results clearly indicated that the two TEOs possessed the same glycoform patterns but differed in quantity at least four glycoforms. It was found that the glycoform patterns were remarkably different between TEO and chicken egg ovalbumin.

Animals↗
PubMed1999

Shortened microsatellite d(CA)21 sequence down-regulates promoter activity of matrix metalloproteinase 9 gene.

One characteristic elements in the promoter of the matrix metalloproteinase 9 (MMP-9) gene is the d(CA) repeat. To investigate whether this element regulates the transcription of the MMP-9 gene and its enzymatic activities, we sequenced the promoter region isolated from esophageal carcinoma cell lines. TE9 cells with low MMP-9 enzymatic activity had the number of d(CA) repeats shortened from 21 to 14 or 18. TE8, TE10 and TE11 cells with high MMP-9 activities had 21 or 23 d(CA) repeats. Luciferase assays using MMP-9 promoter containing 18, 14 or 0 d(CA) repeats showed transcriptional activities which were 50, 50 or 5%, respectively, of the level achieved with promoter containing 21 d(CA) repeats. Sequence analysis of the promoter of 223 Japanese subjects revealed that most had two alleles with 20, 21 or 22 d(CA) repeats, whereas six had one or two alleles with 14, 18 or 19 d(CA) repeats. We postulate that length alteration of the d(CA) repeat causes phenotypic differences among carcinoma cells and that microsatellite instability may contribute to the polymorphism of d(CA) repeat length.

Base Sequence↗
PubMed1999

Characterization of derivatization of sialic acid with 2-aminoacridone and determination of sialic acid content in glycoproteins by capillary electrophoresis and high performance liquid chromatography--ion trap mass spectrometry.

A simple and highly sensitive capillary electrophoresis (CE) method for determining the content of N-acetylneuraminic acid (Neu5Ac) in glycoproteins was developed. Neu5Ac was derivatized with 2-aminoacridone (AMAC) by reductive amination, and the AMAC-Neu5Ac adduct could be readily separated from the other 11 AMAC-derivatized neutral and acidic monosaccharides usually present in glycoproteins by CE in a 0.3 mol/L borate buffer, pH 10.5, and detected at 260 nm. The derivatization of Neu5Ac was achieved at 55 degrees C for 4 h. AMAC-Neu5Ac was stable at 20 degrees C in the dark for at least 12 h while at room temperature it spontaneously converted into another substance with a lower electrophoretic mobility, which was identified as decarboxylated AMAC-Neu5Ac by high performance liquid chromatography - ion trap mass spectrometry (HPLC-ITMS). Concentration and mass of Neu5Ac as low as 1 micromol/L and 35 fmol could be detected. The linear correlation coefficient between the ratio of peak area to migration time of AMAC-Neu5Ac and the concentration of Neu5Ac ranging from 10 to 120 micromol/L was 0.9978 (n=8). This method was successfully applied to the analysis of sialic acid in human urinary trypsin inhibitor (hu-UTI), bovine alpha1-acid glycoprotein (alpha1-AGP) and recombinant human erythropoietin (rhu-EPO). By combination of CE and HPLC-ITMS we found that N-glycolylneuraminic acid (Neu5Gc) was present in bovine alpha1-AGP in addition to Neu5Ac, with a quantity comparable to that of the latter.

Aminoacridines↗
PubMed1999

Coronary artery aneurysms: A 25-patient study.

Coronary artery aneurysm is a rare disorder, characterized by abnormal dilatation of a localized portion or diffuse segments of the coronary artery. We studied clinical demographics, catheterization findings, and clinical outcomes in an Asian patient cohort with documented coronary artery aneurysms. Compared to a Caucasian adult population, our patient cohort had a lower incidence of coronary artery aneurysm (0.25% vs. 2.6%), and more patients with nonobstructive coronary artery aneurysms (70%); age, gender, and coronary distribution were comparable. The initial presentation of myocardial infarction occurred in five patients (5/17, 30%) with nonobstructive coronary artery aneurysms; however, none who were receiving preventive medications consisting of anticoagulant and antiplatelet agents subsequently developed myocardial infarction. We conclude that the incidence of coronary artery aneurysms with or without associated significant coronary stenosis seems to be lower in the Asian population. In contrast, the incidence of nonobstructive coronary artery aneurysms is considerably high and should not be thought of as a relatively benign disease entity if not treated with preventive medications. Rheumatoid arthritis-related vasculitis might be a cause of coronary artery aneurysm. Surgical intervention is based on the severity of coronary artery stenosis. The result of medical treatment has been compatible with long-term survival. Cathet. Cardiovasc. Intervent. 48:31-38, 1999.

Adult↗
PubMed1999

Characterization and analysis of a novel glycoprotein from snake venom using liquid chromatography-electrospray mass spectrometry and Edman degradation.

An N-linked glycosylation in a novel C-lectin protein from snake venom was observed by Edman degradation and liquid chromatography-electrospray mass spectrometry. The peptides obtained by trypsin cleavage were analyzed to confirm the amino acid sequence and Asn5 was found to be the N-glycosylation site. The result was further confirmed by N-glycosidase digestion. In addition, the protein and tryptic peptides with and without glycan chain were characterized by mass spectrometry according to the mass difference. The glycopeptide obtained from proteolytic digestion was analyzed and the glycoforms were identified as high-mannose type by tandem MS coupled with alpha-mannosidase digestion. An oxidized Met residue was detected and located in the protein by mass spectrometry.

Amidohydrolases↗
PubMed1999

Evaluation of arterial compliance in patients with carotid arterial atherosclerosis.

BACKGROUND: High-resolution peripheral vascular sonography has the capability to determine vessel compliance. A number of factors affect compliance in humans, including age, hypertension and atherosclerosis. However, compliance in patients with coronary artery disease (CAD) combined with carotid artery lesions has not been well studied. The objectives of this study were: 1) to determine whether carotid artery compliance is reduced in patients with CAD and carotid artery lesions, and 2) to determine whether decreased arterial compliance is related to an abnormality in vascular wall structure. METHODS: The study participants included 12 patients with CAD and carotid artery disease (group III), 13 patients with CAD only (group II) and 13 age-matched normal subjects who served as controls (group I). High-resolution peripheral vascular ultrasonography was performed to directly visualize the common carotid artery and to measure its diameter and wall thickness. Carotid artery elastic properties were determined relative to arterial diameter and pressure generated within the heart. RESULTS: Carotid artery walls were thicker in Group II and III patients than in normal subjects (1.49 +/- 0.03 mm, 1.98 +/- 0.04 mm, vs 1.22 +/- 0.03 mm, p < 0.05 and p < 0.01). There were significant differences in wall thickness between subgroups of CAD patients (p < 0.01). Carotid distensibility was lower (21.8 +/- 1.2 x 10(-6).N-1.m2, 14.8 +/- 1.7 x 10(-6).N-1.m2, vs 25.6 +/- 1.5 x 10(-6).N-1.m2; p < 0.05 and p < 0.01) and Young's modulus of elasticity was higher (3.12 +/- 0.43 x 10(5).Nm-2, 4.18 +/- 0.30 x 10(5).Nm-2, vs 2.34 +/- 0.23 x 10(5).Nm-2; p < 0.05 and p < 0.01) in group II and III patients than in normal subjects. These two indices of carotid artery compliance also differed between subgroups of CAD (p < 0.01). Increased wall thickness may occur secondary to changes in the architectural structure of the vessel wall, and these atherosclerotic changes lead to decreased compliance of arteries. CONCLUSION: The mechanical properties of the carotid arteries provide reliable information regarding changes caused by atherosclerosis.

Arteriosclerosis↗
PubMed1998

Pathological study of splenomegaly associated with cadmium-induced anemia in rats.

Splenomegaly was observed both in male and female Sprague-Dawley rats after 1 week of exposure to CdCl2 (0.6 mg Cd/kg/day). Spleen weight reached about double that in controls by 8 weeks of Cd exposure. Histopathological examination of the enlarged spleen revealed that iron- and lipid-laden histiocytes were clustered in the periarterial lymphatic sheath, and the red pulp appeared to be expanded. It is noteworthy that electron microscopy revealed marked poikilocytosis and Heinz body formation in red blood cells (RBCs) in both the sinus and cord. Histiocytes were swollen by a granular substance in the cytoplasm and also many secondary lysosomes. These morphological findings indicate that degradation of damaged RBCs induced by exposure to Cd might be promoted in the spleen and possibly cause splenomegaly. This RBC damage-hemolysis-splenomegaly sequence is also considered to be associated with the etiology of Cd-induced anemia. In addition to the abnormal RBC degradation, nuclei of lymphocytes in the Cd-exposed spleen exhibited high electron density, consistent with a preapoptotic state suggesting the immunosuppressive effect of Cd.

Anemia↗
PubMed1998

Growth, respiration and nitrogen content in needles of Scots pine exposed to elevated ozone and carbon dioxide in the field.

Single Scots pine (Pinus sylvestris L.) trees, aged 30 years, were grown in open-top chambers and exposed to two atmospheric concentrations of ozone (O3; ambient and elevation) and carbon dioxide (CO2) as single variables or in combination for 3 years (1994-1996). Needle growth, respiration and nitrogen content were measured simultaneously over the period of needle expansion. Compared to ambient treatment (33 nmol mol(-1) O3 and 350 micromol mol(-1) CO2) doubled ambient O3 (69 nmol mol(-1)) significantly reduced the specific growth rates (SGRs) of the needles in the early stage of needle expansion and needle nitrogen concentration (N1) in the late stage, but increased apparent respiration rates (ARRs) in the late stage. Doubled ambient CO2 (about 650 micromol mol(-1)) significantly increased maximum SGR but reduced ARR and N1 in the late stage of needle expansion. The changes in ARR induced by the different treatments may be associated with treatment-induced changes in needle growth, metabolic activities and turnover of nitrogenous compounds. When ARR was partitioned into its two functional components, growth and maintenance respiration, the results showed that neither doubled ambient O3 nor doubled ambient CO2 influenced the growth respiration coefficients (Rg). However, doubled ambient O3 significantly increased the maintenance respiration coefficients (Rm) regardless of the needle development stage, while doubled ambient CO2 significantly reduced Rm only in the late stage of needle expansion. The increase in Rm under doubled ambient O3 conditions appeared to be related to an increase in metabolic activities, whereas the decrease in Rm under doubled ambient CO2 conditions may be attributed to the reduced N1 and turnover rate of nitrogenous compounds per unit. The combination of elevated O3 and CO2 had very similar effects on growth, respiration and N1 to doubled ambient O3 alone, but the interactive mechanism of the two gases is still not clear.

Journal Article↗
PubMed1998

Full 1H NMR assignment of a 24-nucleotide RNA hairpin: application of the 1H 3D-NOE/2QC experiment.

The subject RNA models the binding site for the coat protein of the R17 virus, as well as the ribosome recognition sequence for the R17 replicase gene. With an RNA of this size, overlaps among the sugar protons complicate assignments of the 1H NMR spectrum. The cross peaks that overlap significantly in 2D-NOE spectra can frequently be resolved by introducing a third, in our approach the double-quantum, frequency axis. In particular the planes in a 3D-NOE/2QC spectrum perpendicular to the 2Q axis are extremely useful, showing a highly informative repeating NOE-2Q pattern. In this experiment substantial J-coupling confers special advantages. This always occurs for geminal pairs (H5'/H5" for RNA plus H2'/H2" for DNA), as well as for H5/H6, for H3'/H4' in sugars with substantial populations of the N-pucker, for H1'/H2' for S-puckered sugars, and usually for H2'/H3'. For the 24-mer RNA hairpin the additional information from the 3D-NOE/2QC spectrum allowed assignment of all of the non-exchangeable protons, eliminating the need for stable-isotope labeling.

Capsid↗
PubMed1998

Biexponential decomposition of a neuraminidase inhibitor prodrug (GS-4104) in aqueous solution.

PURPOSE: To examine the degradation kinetics and identify the degradation products of a neuraminidase inhibitor prodrug. GS-4104. METHODS: Degradation was studied as a function of pH and temperature using a stability-indicating RP-HPLC assay. Degradation products were isolated by RP-HPLC and identified by NMR. Specific rate constants were calculated based on a scheme defined by products(s) analysis. RESULTS: Three distinct degradation products were observed in the pH region studied (pH 2-8): isomer I, GS-4071, and isomer II. Isomer I resulted from the N, N-migration of the acetyl group. Gs-4071 was formed by the hydrolysis of the ethyl ester. Both GS-4071 and isomer I degraded further to isomer II by N, N-acyl migration and ester hydrolysis, respectively. The N, N-acyl migration reaction was characterized using two dimensional heteronuclear multiple bond correlation (HMBC) NMR. The decomposition kinetics of GS-4104 follow a biexponential decay at pH 2-7. The degradation kinetics of Gs-4104 at pH 4.0, 70 degree C were independent of the initial GS-4104 concentration. CONCLUSIONS: The degradation profile indicates that development of solution or solid dosage from of GS-4104 with adequate shelf-life stability at room temperature is feasible.

Amines↗
PubMed1998

Lignocaine plus morphine in bolus patient-controlled intravenous analgesia lacks post-operative morphine-sparing effect.

Lignocaine has been used successfully to treat burn pain and neuropathic pain. We have conducted a randomized, double-blind trial to assess the morphine-sparing effect of intravenous lignocaine in patients with acute pain. After major abdominal surgery, patients were treated with post-operative patient-controlled intravenous analgesia in two groups: group M (n = 25, morphine 0.2 mg mL-1) and group ML (n = 25, morphine 0.2 mg mL-1 plus lignocaine 3.2 mg mL-1). The patient-controlled analgesia system was programmed to deliver a 5 mL bolus with a 50 mL per 4 h limit; the lockout time was 10 min. Both groups closely resembled each other in terms of demographic data, pain intensity, cumulative morphine dose and the morphine-associated nausea, vomiting and pruritus. However, the sedation scores in group ML patients during the first post-operative day were significantly greater than those in group M. The incidence of lignocaine-related lightheadedness and dry mouth was also significantly greater in group ML than in group M. It was concluded that the addition of lignocaine 3.2 mg mL-1 to morphine 0.2 mg mL-1 given via patient-controlled analgesia system does not provide a post-operative morphine-sparing analgesic effect.

Abdomen↗
PubMed1998

Temporal and spatial expression of erbB4 in ectodermal and mesenchymal cells during primary palatogenesis in noncleft and cleft strains of mice.

Primary palatogenesis in mice is similar to that in humans, and spontaneous cleft lip appears to be multifactorially determined in both. Binding of a ligand to erbB4 has been shown to stimulate the receptor's protein kinase activity, which subsequently stimulates a signal-transduction cascade leading to cell growth and differentiation, and to morphogenesis during development. In this study, an immunohistochemical technique was used to investigate the temporal and spatial expression of erbB4 in the primary palate of cleft (A/WySn) and noncleft strains of mice (BALB/cBy). Positive staining of erbB4 was found in ectodermal and mesenchymal cells of facial prominences before the primary palate formation stage (day 10, hour 20) in both strains. During the primary palate formation stage (day 11, hour 20), positive staining of erbB4 was found in the ectodermal and mesenchymal cells of the facial prominences of the noncleft strain, but not in those of the cleft strain. These results suggest erbB4 expression may be associated with normal primary palatogenesis of mice and, conversely, cleft lip may be associated with a deficiency of erbB4 expression during primary palate formation in mice.

Animals↗
PubMed1997

Solution structure of a duplex DNA with an abasic site in a dA tract.

The presence of dA tracts in DNA can lead to stable curvature of the DNA, and this curvature can be important in gene regulation, DNA packaging, and other processes. Since damage to DNA may eliminate this stable curvature, the solution state structure of the duplex of d(CGCAAAAATGCG) paired with d(CGCATTDTTCCG), with D indicating an abasic site, has been determined. The undamaged DNA bends into the major groove both in solution and in the crystal state. The presence of the abasic site in the dA tract region induces changes in the DNA structure up to four base pairs away from the damaged site. The structure of the DNA is dependent on whether the abasic site is in the alpha or beta hemiacetal form. These consequences are quite different from the more localized effects that have been observed for "normal" DNAs containing abasic sites. Thus, there appears to be a strong sequence dependence of the structural effects of abasic sites just as there is for undamaged DNA. Furthermore, these results indicate that the presence of an abasic site can alter DNA bending and hence is likely to have significant long range effects on gene regulation and other properties that are dependent on the stable curvature of DNA.

DNA↗