[Operative correction of pectus accompany with atrial septal defect].
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Abnormalities, Multiple↗
Biomedical subjects
S X Chen
Publications and source records attributed to S X Chen.
Regulation of type II phosphatidylinositol phosphate kinase by tyrosine phosphorylation in bovine rod outer segments.
Type II phosphatidylinositol phosphate kinase (PIPKII) is an enzyme responsible for the synthesis of phosphatidylinositol-4,5-bisphosphate (PI-4,5-P(2)) from phosphatidylinositol-5-phosphate (PI-5-P). In this study, we demonstrate the presence of PIPKII alpha in bovine photoreceptor rod outer segments (ROS) and the involvement of tyrosine phosphorylation in the regulation of its activity. PIPKII activity in bovine ROS was verified by the preferential conversion of synthetic dipalmitoyl PI-5-P to PI-4,5-P(2), lack of effect of phosphatidic acid, inhibition by heparin, immunoreaction with an anti-PIPKII alpha antibody on Western blots, and immunocytochemical localization in bovine and rat ROS by anti-PIPKII alpha. Immunoprecipitates of bovine ROS with the anti-PIPKII alpha antibody possessed PIPK enzymatic activity and preferentially used PI-5-P as substrate for PI-4,5-P(2) biosynthesis. The activity of PIPKII was greatly increased under conditions favoring tyrosine phosphorylation in ROS, and PIPKII activity was immunoprecipitated with anti-phosphotyrosine (anti-PY) antibodies from tyrosine phosphorylated ROS. Preincubation of ROS with tyrosine kinase inhibitors almost abolished the kinase activity in the anti-PY immunoprecipitates. Immunoblot analysis showed that PIPKII alpha was present in anti-PY immunoprecipitates from phosphorylated ROS but not from nonphosphorylated controls. We conclude that PIPKII alpha is present in ROS and that its activity is regulated by tyrosine phosphorylation.
Animals↗
[Clinical study of ischemic preconditioning on isolated lung perfusion with chemotherapeutic agents in the treatment of unresectable lung cancer].
OBJECTIVE: To determine the effect of ischemic preconditioning on isolated lung perfusion (ILP) with chemotherapeutic agents in the treatment of unresectable lung cancer. METHODS: Eight patients with unresectable cancer or metastatic sarcomas in lungs underwent isolated single lung perfusion with doxorubicin. Eight patients were randomly divided into two groups: control group (Group C) and ischemic preconditioning group(Group IP). Group C was only performed isolated lung perfusion with doxorubicin; Group IP was performed isolated lung perfusion with doxorubicin after ischemic preconditioning (in ischemic preconditioning procedure, right or left pulmonary artery was clamped for 10 minutes, then released for 15 minutes). RESULTS: The mean pulmonary artery pressure (MpaP) after ILP in Group IP was much lower than that in Group C (P < 0.05). The PaO2 after ILP in Group IP was much higher than that in Group C(P < 0.01). The lung histologic examination after ILP showed that pulmonary edema, inflammatory cell infiltration, mild focal hemorrhage and alveolar disruption in Group C were significantly serious than those in Group IP, but there was no hospital death in Group C or in Group IP. The complications included hypovolemia shock and acute lung injury. Following up 2 months to 10 months, no death was observed, and the tumours diminished in various degrees or disappeared in the two groups. CONCLUSION: Isolated lung perfusion with chemotherapy can be done safely and effectively in patients with unresectable lung malignancies and metastatic sarcoma in the lung, and ILP can cause lung injury, but lung ischemic preconditioning can reduce the lung injury after isolated lung perfusion.
Adult↗
[Delayed cardioprotection of captopril in patients undergoing open heart surgery].
OBJECTIVE: To investigate whether there is delayed cardioprotection of captopril pretreatment in open heart surgery. METHODS: Twenty patients with ventricular septal defect (VSD) undergone open heart surgery were randomly divided into captopril group (CAP group) and control group. In the CAP group, patients were pretreated with captopril (1 mg.kg-1, oral) at 48 hours before operation, No special treatment was given at the same time in the control group. Release of creatine phosphokinase-MB (CK-MB) and myocardial adenosine triphosphate (ATP) content was studied. Heart shock protein 70 (HSP70) in myocardum was examined using Western blotting analysis. RESULTS: No statistically significant difference was found in release of CK-MB between control group and CAP group. ATP depletion was (1.40 +/- 0.56) mumol.g-1, (2.06 +/- 0.72) mumol.g-1 in CAP group and control group respectively (P < 0.05). Western blotting analysis showed that both group had HSP70 expression. In CAP group, HSP70 expression was higher than that in control group. CONCLUSION: The results suggest that captopril pretreatment 48 hours before operation could reduce ATP depletion in pediatric patients of VSD during open-heart surgery, and HSP70 might be involved in the delayed cardioprotection induced by captopril.
Angiotensin-Converting Enzyme Inhibitors↗
Measurement errors in line transect surveys where detectability varies with distance and size.
When using bivariate line transect methods to estimate the biomass density of a tightly clustered biological population, it is generally assumed that both the perpendicular distance from the trackline to the cluster and the cluster size, or biomass, are measured without error. This is unlikely to be the case in practice. In this article, assuming additive mean zero errors in distance and multiplicative errors in size, we develop an estimator of density that corrects for these errors. We use the method of moments for the case of gamma cluster size, randomly placed transect lines, and the generalized exponential detection function. We derive results that show that it may not be necessary to correct for errors in distance or size when the distance and size estimates are not biased. When the size estimates are biased, the biomass density estimate has approximately the same bias as the size estimates. The work is illustrated in the context of annual aerial surveys for juvenile southern bluefin tuna in the Great Australian Bight.
Animals↗
A comparison of ischemic preconditioning versus terminal warm cardioplegia with controlled reperfusion in open heart operation.
BACKGROUND: The purpose of this study was to evaluate the effects of three different methods of cardioprotection in patients undergoing valve replacement. METHODS: Ninety patients undergoing elective valve replacement were randomly divided into three groups. In group 1 (n=30), the patients received intermittent cold blood cardioplegia. In group 2 (n=30) they received terminal warm cardioplegia and controlled reperfusion, and in group 3 (n=30), the patients received two cycles of ischemia (2 minutes) and reperfusion (3 minutes) before heart arrest induced by cold blood cardioplegia. The parameters of cardiac function, creatine kinase MB, and clinical outcomes were recorded to assess the effects of experiment. RESULTS: The major preoperative and intraoperative variables are comparable within the three groups. The number of patients requiring the support of inotropic agents was 70% (21/30), 33% (11/30) and 40% (12/30) in group 1, 2 and 3, respectively (p<0.05). The doses of inotropic agent in groups 2 and 3, were significantly lower than in group 1 (1.5+/-0.3 and 1.8+/-0.4 versus 4.5+/-0.8 microg x kg x min(-1), p<0.01) during the first 24 hours after operation. Two deaths (30 day-hospital mortality) occurred, one in group 1 and one in group 2. The cardiac index at 2 hours after bypass discontinuing were 2.2+/-0.04, 3.0+/-0.1 and 2.8+/-0.05 L/m(2) in group 1, 2 and 3, respectively (p<0.01). The left ventricular stroke work index were 24.8+/-1.3, 34.5+/-1.6 and 31.6+/-1.2 g/m x m(2) in group 1, 2, 3, respectively (p<0.01). The release of CK-MB in group 2 and 3 were lower than in group 1 (68+/-7, 81+/-9 versus 116+/-10 IU/L, p<0.01). CONCLUSIONS: Terminal warm cardioplegia with controlled aortic root reperfusion and ischemic preconditioning equally improve cardiac function and reduce the requirement of inotropic agents in patients undergoing valve replacement.
Adult↗
[Synthesis and antibacterial activity of 3-hydroxy-6-O-methylerythromycin-9-O-substituted oxime derivatives].
AIM: To study the antibacterial activity against erythromycin-resistant organisms of 3-hydroxy-6-O-methylerythromycin-9-O-substituted oxime derivatives, a new route of synthesis with 6 steps was designed. METHODS: The starting material, erythromycin A (1), was reacted with NH2OH.HCI to give 2, which reacted with BzBr to give 3. Selective methylation of C-6 hydroxy group using iodomethane afforded 4, which was hydrolyzed with loss of the 3-cladinosyl to give 5. Compound 5 was reduced by H2 to provide 6, which was treated with substituted benzyl chlorides to provide 7 and 8. RESULTS: Four unreported compounds (5-8) were synthesized. The antibacterial activity of the new compounds were tested in vitro against both erythromycin-susceptible and erythromycin-resistant organisms. The compounds 5 (MIC = 1 microgram.mL-1) and 6 (MIC = 1 microgram.mL-1) showed significant activity against Staphylococcus epidermidis 26,069 compared with erythromycin (MIC = 4 micrograms.mL-1). Compounds 5 (MIC = 16, 4 micrograms.mL-1), 7 (MIC = 32, 64 micrograms.mL-1) and 8 (MIC = 64, 32 micrograms.mL-1) showed better activity against Streptococcus pneumoniae 64 and Staphylococcus aureus 9525 than erythromycin (MIC > 128, 128 micrograms.mL-1). CONCLUSION: 3-hydroxy-6-O-methylerythromycin-9-O-substituted oxime derivatives have stronger antibacterial activity against some erythromycin-resistant organisms than erythromycin A.
Anti-Bacterial Agents↗
[Protective effects of low dose nitric oxide inhalation on lung ischemia/reperfusion injury during cardiopulmonary bypass surgery].
OBJECTIVE: Out aim is to study the effects of inhaling nitric oxide(NO) on the pulmonary ischemia/reperfusion injury during cardiopulmonary bypass surgery. METHODS: Cardiac valve replacement was performed on twenty patients with chronic rheumatic heart valve disease under cardiopulmonary bypass, and they were randomly divided into two groups: control group(n = 10) and NO group(n = 10). We monitored the following: mean pulmonary arterial pressure(MPaP), pulmonary vascular resistance(PVR), peak airway pressure (PAP), cyclic guanosine monophosphate(cGMP), inter-cellular adhesion molecule-1(ICAM-1), xanthinoxidase (XOD), malondialdehyde(MDA), PaO2 and the duration of post-operative mechanical ventilation. RESULTS: The PAP, MPaP and PVR in the control group were much higher than those in NO group after reperfusion(P < 0.05). The durations of postoperative mechanical ventilation in NO group were shorter than those in the control group(P < 0.01). The cGMP and PaO2 after reperfusion in NO group were higher(P < 0.01), and the ICAM-1, XOD, MDA were lower(P < 0.05) than those in the control group. CONCLUSIONS: 1. If aortic clamp time is over 1 h, lung ischemia/reperfusion injury may occur during cardio-pulmonary bypass surgery. 2. Inhaling 20 ppm NO in the early phase of reperfusion has protective effects on the lung ischemia/reperfusion injury during cardio-pulmonary bypass surgery. 3. The mechanisms of the protective effects may be related with the increase of cGMP and the decrease of ICAM-1, XOD, MDA.
Administration, Inhalation↗
[Ischemic preconditioning decrease the release of cardiac troponin T during heart valve replacement].
Using cardiac troponin T(cTnT), a highly sensitive and specific marker of myocardial injury, we evaluated the effects of ischemic precondition on ischemic reperfusion myocardial injury. Thirty two patients were randomly divided into control group(n = 16) and ischemic preconditioning group(n = 16). The marker cTnT was measured in each group before operation, and 4 h, 24 h and 72 h after operation. The results showed that the peak value of cTnT was lower, and more quickly recovered in the preconditioning group than that in the control. It is suggested that ischemic preconditioning exert an evidently protective effect on ischemic reperfusion myocardial injury.
Adult↗
Identification of a locus for disseminated superficial actinic porokeratosis at chromosome 12q23.2-24.1.
Disseminated superficial actinic porokeratosis is an autosomal dominant cutaneous disorder characterized by many uniformly small, minimal, annular, anhidrotic, and keratotic lesions. The genetic basis for this disease is unknown. Using a genomewide search in a large Chinese family, we identified a locus at chromosome 12q23.2-24. 1 responsible for disseminated superficial actinic porokeratosis. The fine mapping study indicates that the disseminated superficial actinic porokeratosis gene is located within a 9.6 cM region between markers D12S1727 and D12S1605, with a maximum two-point LOD score of 20.53 (theta = 0.00) at D12S78. This is the first locus identified for a genetic disease where the major phenotype is porokeratosis. The study provides a map location for isolation of a gene causing disseminated superficial actinic porokeratosis.
China↗
A new cytotoxic polyhydroxysterol from soft coral Sarcophyton trocheliophorum.
A new cytotoxic polyhydroxysterol, 23,24-dimethylcholest-16(17)-E-en-3beta,5alpha,6beta,2 0(S)-tetraol (2), together with nine known compounds was isolated from the soft coral Sarcophyton trocheliophorum. Their structures were determined by spectroscopic methods. Compound 2 showed potent growth inhibitory activity against human HL60 leukemia, M14 skin melanoma, and MCF7 breast carcinoma cells with EC50 values of 2.8, 4.3, and 4.9 microg/ml, respectively, and exhibited minimal toxicity to normal human peripheral blood lymphocytes.
Animals↗
Bioactivities of methyl allyl disulfide and diallyl trisulfide from essential oil of garlic to two species of stored-product pests, Sitophilus zeamais (Coleoptera: Curculionidae) and Tribolium castaneum (Coleoptera: Tenebrionidae).
Two of the major constituents of the essential oil of garlic, Allium sativum L., methyl allyl disulfide and diallyl trisulfide, were tested against Sitophilus zeamais Motschulsky and Tribolium castaneum (Herbst) for contact toxicity, fumigant toxicity, and antifeedant activity. The contact and fumigant toxicities of diallyl trisulfide were greater than that of methyl allyl disulfide to the adults of these two species of insects. These two compounds were also more toxic to T. castaneum adults than to S. zeamais adults. Older T. castaneum larvae were more susceptible to the contact toxicity of the two compound, whereas younger larvae were more susceptible to the fumigant toxicity of these compounds. Both compounds reduced egg hatching of T. castaneum and subsequent emergence of progeny. Diallyl trisulfide totally suppressed egg hatching at 0.32 mg/cm2, and larval and adult emergence at 0.08 mg/cm2. Methyl allyl disulfide significantly decreased the growth rate, food consumption, and food utilization of adults of both insect species, with feeding deterrence indices of 44% at 6.08 mg/g food for S. zeamais and 1.52 mg/g food for T. castaneum. However, it did not affect any nutritional indices of T. castaneum larvae. Diallyl trisulfide significantly reduced all of the nutritional indices in all of the insects tested. Feeding deterrence indices of 27 and 51% were obtained in S. zeamais adults and T. castaneum larvae, respectively, at the concentration of 2.98 mg/g food, whereas feeding deterrence of 85% was achieved in T. castaneum adults at a much lower concentration of 0.75 mg/g food. Hence, diallyl trisulfide is a more potent contact toxicant, fumigant and feeding deterrent than methyl allyl disulfide.
Allyl Compounds↗
[Study on continuous synthesis of galacto-oligosaccharide by immobilized Bacillus stearothermophilus].
The galacto-oligosaccharide was synthesized continuously by immobilized Bacillus stearothermophilu producing beta-galactosidase in fibrous bed reactor. The effect of substrate concentration, pH, reaction temperature and retention time on production of GOS was investigated. The optimal reaction conditions were determined. Substrate concentration were 450 g/L; Reaction temperature was 55 degrees C; pH was 7.0; Residence time was 100 min. The product yield reached up to 50.7%. GOS synthesis was promoted by feeding 1.5% D-glactose after 24 h. The immobilized cell reactor can work stably for 120 h.
Galactose↗
Hydroxyl-radical production in physiological reactions. A novel function of peroxidase.
Peroxidases catalyze the dehydrogenation by hydrogen peroxide (H2O2) of various phenolic and endiolic substrates in a peroxidatic reaction cycle. In addition, these enzymes exhibit an oxidase activity mediating the reduction of O2 to superoxide (O2.-) and H2O2 by substrates such as NADH or dihydroxyfumarate. Here we show that horseradish peroxidase can also catalyze a third type of reaction that results in the production of hydroxyl radicals (.OH) from H2O2 in the presence of O2.-. We provide evidence that to mediate this reaction, the ferric form of horseradish peroxidase must be converted by O2.- into the perferryl form (Compound III), in which the haem iron can assume the ferrous state. It is concluded that the ferric/perferryl peroxidase couple constitutes an effective biochemical catalyst for the production of .OH from O2.- and H2O2 (iron-catalyzed Haber-Weiss reaction). This reaction can be measured either by the hydroxylation of benzoate or the degradation of deoxyribose. O2.- and H2O2 can be produced by the oxidase reaction of horseradish peroxidase in the presence of NADH. The .OH-producing activity of horseradish peroxidase can be inhibited by inactivators of haem iron or by various O2.- and .OH scavengers. On an equimolar Fe basis, horseradish peroxidase is 1-2 orders of magnitude more active than Fe-EDTA, an inorganic catalyst of the Haber-Weiss reaction. Particularly high .OH-producing activity was found in the alkaline horseradish peroxidase isoforms and in a ligninase-type fungal peroxidase, whereas lactoperoxidase and soybean peroxidase were less active, and myeloperoxidase was inactive. Operating in the .OH-producing mode, peroxidases may be responsible for numerous destructive and toxic effects of activated oxygen reported previously.
Enzyme Inhibitors↗
Estimation in independent observer line transect surveys for clustered populations.
This paper introduces a framework for animal abundance estimation in independent observer line transect surveys of clustered populations. The framework generalizes an approach given in Chen (1999, Environmental and Ecological Statistics 6, in press) to accommodate heterogeneity in detection caused by cluster size and other covariates. Both parametric and nonparametric estimators for the local effective search widths, given the covariates, can be derived from the framework. A nonparametric estimator based on conditional kernel density estimation is proposed and studied owing to its flexibility in modeling the detection functions. A real data set on harbor porpoise in the North Sea is analyzed.
Animals↗
A condition for designing bus-route type access site surveys to estimate recreational fishing effort.
A theoretical framework for using bus-route surveys to estimate recreational fishing effort has been established by taking into account the arrival and departure distributions of the fishing parties. Properties of a fishing effort estimator proposed by Robson and Jones (1989) are investigated. It is found that the estimator is not automatically unbiased; rather, a condition on the survey design has to be satisfied in order to be unbiased. The condition is simple and can be easily implemented.
Animals↗
Chromatographic purification of human alpha 1 proteinase inhibitor from dissolved Cohn fraction IV-1 paste.
A novel chromatographic process for purification of alpha 1 proteinase inhibitor (alpha 1-PI) from Cohn fraction IV-1 paste is described. This process has been successfully scaled up to 50-1 columns. It involves DEAE chromatography, sulfopropyl (S) cation chromatography, tri-n-butyl phosphate (TNBP)-cholate treatment, a second S cation chromatography, freeze-drying and dry-heat. The process has been optimized for purity, yield, lipid removal, chemical usage and water consumption. Filtration after TNBP-cholate treatment plays a key role in ensuring a low lipid content in the final product. Pre-equilibration with high salt buffer is necessary to reduce the water consumption significantly during the ion-exchange chromatography equilibration step. The final product is approximately 95% pure by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with a 64% to 70% yield from IV-1 paste.
Blood Proteins↗
A new antiplatelet diarylheptanoid from Alpinia blepharocalyx.
A new diarylheptanoid, 1,7-bis(4-hydroxyphenyl)-3-hydroxy-1,3-heptadien-5-one (1), along with seven other known compounds, were isolated from the seeds of Alpinia blepharocalyx. Of these, compounds 1 and 3 showed strong inhibition of collagen-induced, arachidonic acid-induced, and adenosine diphosphate-induced platelet aggregation of human whole blood. Compound 3 also strongly inhibited ristocetin-induced platelet aggregation. Structures of these compounds were elucidated by spectroscopic and chemical means.
China↗