Search PubMed⌕ Search

Biomedical subjects

W Wang

Publications and source records attributed to W Wang.

At least 1,045 records · Page 58Linked to original sources
PubMed1997

Neutrophil infiltration is involved in 5-fluorouracil induced lipid peroxidative damage of the small intestine.

UNLABELLED: This study evaluated the mechanisms of 5-fluorouracil (5-FU) induced intestinal damage by investigating the lipid peroxide (LPO) level, myeloperoxidase (MPO) activity and disaccharidase activity in rats. Group I animals (n = 6) were sacrificed and served as a normal control group. Group II animals (n = 24) were given a single intraperitoneal injection of 5-FU (150 mg/kg) and every 8 rats were sacrificed on day 1, 3 and 5 after injection respectively. RESULTS: LPO concentration in blood and intestinal mucosa was significantly higher in the group II than in the group I on day 1 and 3 (P < 0.05). MPO activity was significantly higher in the group II than in the group I at different times (P < 0.01). Lactase activity on day 5 (P < 0.01); sucrase activity (P < 0.01 and P < 0.05 respectively) and maltase activity (P < 0.01) on day 3 and 5, were significantly lower in the group II than in the group I. CONCLUSION: The results indicate that neutrophil infiltration may be involved in 5-FU-induced lipid peroxidative damage of the small intestine which was reflected by the decreased disaccharidases activities.

Animals↗
PubMed1997

[Separation of soybean agglutinin by hydrophobic-interaction chromatography].

The soybean agglutinin (SBA) was separated with hydrophobic-interaction chromatography (HIC) in this work. HIC of the crude lectin extract of SBA was performed on Phenyl-Sepharose CL-4B column, 10 cm x 2.5 cm i.d., at a flow-rate of 1.0 mL/min. A 20 mL sample of the crude extract was applied to the column previously equilibrated with the buffer, 0.01 mol/L PBS containing ammonium sulfate (60% of saturation concentration). The column was eluted with the starting buffer, then with the buffer containing 30% saturation of ammonium sulfate, and finally with 0.01 mol/L PBS. Fractions were detected by UV absorbance at 280 nm and assayed for hemagglutinating activity. The results show that the purification-fold was as high as 35 and the recovery of activity was 100%.

Chromatography↗
PubMed1997

[Reversed-phase high performance liquid chromatographic (RP-HPLC) analysis of taxol and related taxanes extracted from Taxus wallichiana zucc].

A method for determination of taxol, 10-deacetyl-7-epitaxol, cephalomannine, 10-deacetyl taxol, baccatin III and 10-deacetylbaccatin III, is reported and their retention mechanism is also discussed. These compounds were separated well by RP-HPLC on a Resolvepak C18 column with methanol-water-phosphoric acid (60:40:0.5) as mobile phase and UV detector at 228nm. The powdered stems were extracted with 95% ethanol, refluxed for 8 hrs and filtered and then the residue was partitioned three times between water and chloroform. The organic phase was evaporated to dryness and the residue dissolved in reagent methanol and was submitted to HPLC analysis. The results showed that there is a linear relationship between the peak area and the amount of these compounds over the range of 0.1-2.0microg. The lowest detectable concentration of these compounds was below 0.1microg.

Chromatography, High Pressure Liquid↗
PubMed1997

[Analysis of the stereoisomers of 14 pyrethroids by capillary gas chromatography].

The separation of stereoisomers of 14 pyrethroids has been studied by capillary gas chromatography. The pyrethroids are cypermethrin (P1), phenothrin (P2), allethrin (P3), prallethrin (P4), tetramethrin (P5), permethrin (P6), cyfluthrin (P7), fenvalerate (P8), flucythrinate (P9), bromofenvalerate (P10), fluvalinate (P11), methothrin (P12), resmethrin (P13) and py115 (P14). The gas chromatographic conditions were as follows. Column 1: fused silica, 10m x 0.53mm x 1.0microm film (QF-1); columntemperature: 180 degrees C-260 degrees C depending on the pyrethroids analysed; the temperature of injector and detector: 280 degrees C; carrier gas: H2 4.6mL/min; detector: FID; spilt ratio: 5:1, sample size 1.0 L. The stereoisomers of P2, P3, P4, P5, P6, P8, P9, P10, P12 and P10 can be completely separated by QF-1 column. However the stereoisomers of P11 can not be separated and the three peaks of P1 and P7 have been only separated by column 1. In comparing with packed column of QF-1, there are advantages in superior resolution, lower oven temperature and shorter analysis time for capillary column of QF-1. Column 2: fused silica HP-5 (crosslinked 5% phenyl methyl silicone) 25m x 0.32mm x 1.0microm film; column temperature: P1 and P7 250 degrees C, P11 260 degrees C, and P14 200 degrees C; carrier gas: H2 2.6mL/min. Other conditions were the same as the column 1 described. The stereoisomers of P1, P7, P11 and P14 can be separated, but the separation of stereoisomers was not sufficient. The stereoisomers of P2, P5, P6, P8, P9, P10, P12 and P13 can be completely separated by HP-5 capillary column. However separation on the HP-5 capillary column is not sufficient for diastereoisomers of P3 and P4.

Chromatography, Gas↗
PubMed1997

[Determination of R- and S-mephenytoin in human urine by gas chromatography].

The levels of R- and S-mephenytoin in human urine were determined by chiral capillary gas chromatography with nitrogen-phosphorus detector. The conditions of the chromatography and detection included a chiral capillary column (Chirasil-Val, 25 m x 0.25 mm i.d., Alltech), column temperature (T) 190 degrees C, injector T 220 degrees C, detector T 240 degrees C, and the flow-rates of 0.85, 3.5 and 120 mL/min for nitrogen, hydrogen and air respectively. Based on the above conditions, the satisfactory separation of R- and S-mephenytoin was gained, and other interference from urine sample was not found. The linear curves for both tested compounds ranged between 12.5 and 2500 microg/L, with a minimum detectable concentration of about 6 microg/L. Because of its simplicity, rapidity, sensitivity and accuracy, this method has been extensively used for testing metabolic ability of S-mephenytoin polymorphic oxidation in the Chinese populations and for the determination of the activity of hepatic drug-metabolizing enzyme CYP2C19 using mephenytoin S/R ratio of the urine samples of subjects as an indicator.

Anticonvulsants↗
PubMed1997

Differences in the incidence of the CYP2C19 polymorphism affecting the S-mephenytoin phenotype in Chinese Han and Bai populations and identification of a new rare CYP2C19 mutant allele.

The incidence of the S-mephenytoin polymorphism was compared in two Chinese ethnic groups, Han (n = 101) and Bai (n = 202) by phenotype and genotype analysis. The frequency of poor metabolizers (PMs) in Han vs. Bai subjects was 19.8% vs. 13.4%. Han subjects had a higher frequency of the mutant CYP2C19m1 allele (0.366 vs. 0.257, P < .01) and a lower frequency of the wild-type allele (0.559 vs. 0.688, P < .01) than Bai subjects, which is consistent with the difference in the frequencies of PMs between the two ethnic groups. This results in a lower percentage of homozygous wild-type extensive metabolizers of mephenytoin (EMs) in Han subjects than in Bai subjects (40% vs. 59%, P = .005). Therefore, Han subjects may be more susceptible than Bai subjects to the drugs metabolized by the CYP2C19 enzyme. Ratios of urinary S/R-mephenytoin in homozygous EMs were lower than those of heterozygous EMs for both Han and Bai subjects, which shows a gene-dosage effect. Genotype analysis identified all but one PM as homozygous or heterozygous for the two known mutant CYP2C19m1 and/or CYP2C19m2 alleles. A single Bai PM outlier was shown to be heterozygous for CYP2C19m1 and a new mutant CYP2C19 allele containing a single amino acid change of Arg433 --> Trp433. A genotyping test demonstrated that only this one individual carried this rare allele (frequency of 0.0025 in Bai subjects).

Alleles↗
PubMed1997

Treatment of capillary vascular malformation (port-wine stains) with photochemotherapy.

One-hundred and thirty patients (85 female, 45 male) with port-wine stains were treated with photodynamic therapy, also called photochemotherapy, which recently has become acknowledged as effective for a variety of malignant tumors. Probably based on the photochemical reaction with the generation of toxic species, photochemotherapy results in endothelial cell injury and death of abnormal capillaries under overlying epidermis. A retrospective review of 118 available patients with port-wine stains reveals that 98.3 percent responded to photochemotherapy with varying degrees of success after one-time treatment. Results were reported under a simple classification system ranging from ordinary to dilated to posttreatment type. In the ordinary group, the results evaluated as excellent, good, fair, and poor were 37.8, 53.7, 8.5, and 0 percent, respectively, before a second treatment; the treated area was an average of 9.8 (range 7 to 13) cm in diameter. In addition, hypertrophic scars, permanent hyperpigmentation, and hypopigmentation were not seen based on proper parameters. Photochemotherapy offers a potentially efficient and promising choice based on a completely different mechanism from that of selected photothermal therapy with the pulsed-dye laser.

Adolescent↗
PubMed1997

Duplex PCR of the Y-27H39 and HPRT loci with reference to Japanese population data on the HPRT locus.

Using a duplex polymerase chain reaction (PCR) system, we successfully amplified GATA microsatellite loci Y-27H39 and HPRT on the Y and X chromosomes, respectively, and detected their alleles with a digoxigenin-labeled (GATA)6 probe. Among 450 unrelated Japanese including 225 females, we found 6 HPRT alleles ranging from 155 to 175 nucleotides with a simple repeat structure comprising 11 to 16 repeats. The duplex PCR is highly informative in Japanese.

Alleles↗
PubMed1997

Improved methods for making and using glass knives.

We have observed over time that the right side of a glass knife is the optimal cutting edge for microtomy if the counterpiece (heel opposite the edge) is controlled within 1 mm. The right cutting edge has been considered the "saw toothed" side and has not been used for ultrathin sectioning. We have observed that the right cutting edge is sharper and more durable than the left. Light and scanning electron microscopy were used to observe the cutting edge, and transmission electron microscopy was used to examine semithin and ultrathin sections of animal and plant tissues cut by the right and left sides of the cutting edge. The results indicate that the cutting edge becomes sharper and more durable from left to right. Both the quality and efficiency of ultrathin sectioning is improved by using the right cutting edge.

Animals↗
PubMed1997

Thrombin, thrombomodulin and TAFI in the molecular link between coagulation and fibrinolysis.

The thrombin thrombomodulin dependent activation of the plasma protein TAFI (Thrombin Activatable Fibrinolysis Inhibitor) and Subsequent Inhibition of Fibrinolysis by the TAFIa is described. Work to date indicates that TAFIa is a carboxypeptidase B enzyme that suppress fibrinolysis most likely by down regulating the cofactor functions of partially degraded fibrin. The existence of TAFI provides the explanation for the apparent profibrinolytic effect of activated protein C. and implies the existence of an explicit molecular connection between the blood coagulation of fibrinolytic cascades that is expressed through the thrombin thrombomodulin dependent activation of TAFI. Thus, thrombin generation can, in principle, result in the suppression of fibrinolysis.

Amino Acid Sequence↗
PubMed1997

Intestinal alkaline phosphatase: role in the depressed gut lipid transport after trauma-hemorrhagic shock.

Although studies have indicated that the gut lipid absorptive capacity is impaired after trauma and hemorrhagic shock, the mechanism responsible for this remains unknown. The aim of this study, therefore, was to determine whether intestinal alkaline phosphatase (IAP) plays any role in the depressed gut lipid absorptive function observed under such conditions. To determine this, 5 cm midline laparotomy (i.e., trauma induced) was performed in the rats, and animals were then bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of shed blood volume was returned in the form of Ringer's lactate. The rats were resuscitated with four times the volume of maximal bleedout with Ringer's lactate over 60 min. For in vivo lipid loading test, 1 mL olive oil was given intraduodenally upon the completion of resuscitation. The enterocytes were isolated at either 0, 1.5, or 5 h after fat feeding, and the soluble, membranous and pre-chylomicron (pre-CM) IAP activities as well as triglyceride contents were determined thereafter. The results indicated that the soluble IAP activity in the villus tip cells isolated from trauma-hemorrhaged rats increased significantly at 0, 1.5, or 5 h after fat feeding. The pre-CMIAP activity, however, decreased markedly in villus tip cells at 1.5 or 5 h after lipid administration, which was associated with the decreased pre-CM triglyceride contents in villus tip cells under such conditions. The altered IAP activity in villus tip cells, therefore, appears to play a role in the depressed gut lipid absorption and transport following trauma-hemorrhage and resuscitation.

Alkaline Phosphatase↗
PubMed1997

[Genetic diversity and phylogenetic relationships among Chinese Macacas based on protein electrophoresis].

In this paper, using protein electrophoresis method, we studied proteinpolymorphism and genetic divergence of 5 species in Genus Macaca: M. mulatta, M. arctoides, M. assamensis, M. thibetana, M. fascicularis. A total of 30 genetic loci were analyzed for 29 individuals, including 4 Nycticebus pygmaeus as outgroup. For the 19 M. mulatta, 9 loci were found to be polymorphic. Accordingly, the percentage of polymorphic loci, P = 0.3; the mean number of alleles, A = 1.4, and the mean heterozygosity, H = 0.1045, indicating a rather high level of genetic diversity in this species. Furthermore, 10 loci showed polymorphic among the 5 species, which can be used as information loci for phylogenetic reconstruction. Three programs (conml, neighbor, fitch) in PHYLIP 3.5 c were chosen to construct phylogenetic trees. All of the three trees show support a close relationship between M. mulatta and M. fascicularis. However, two trees have the same topology, suggesting that M. arctoides belongs to an independent species group, while M. assamensis and M. thibetana are closely related and belong to another species group, and the other tree gives a different topology which implies that M. arctoides, M. assamensis and M. thibetana belong to one species group.

Animals↗
PubMed1997

Nutrition assessment in children with sickle cell disease.

Children with sickle cell disease have decreased height and weight when compared with their peers. Although exact reasons for poor growth have not been established, increased calorie and protein needs and deficiencies in zinc, folic acid, and vitamins A, C, and E may be factors. To determine whether inadequate nutrient intake contributes to this poor growth, we conducted a survey of the nutrition knowledge and practices of families affected by sickle cell disease. Sixty-one patients with a median age of 8 years (range, 13 months to 17 years) participated in the study. Patients with homozygous S hemoglobin (sickle cell) disease (Hb SS, n = 34) and sickle beta zero thalassemia (Hb S beta zero-thalassemia, n = 2) were combined; 19% were below the fifth percentile for height. The other patients, with sickle hemoglobin C disease (Hb SC, n = 21) and sickle beta plus thalassemia (Hb beta(+)-thalassemia, n = 4), were grouped, and 4% were below the fifth percentile for height (P = .043). Ninety percent of the study patients or their parents were familiar with the food groups indicated on the US Department of Agriculture's Food Guide Pyramid, but most patients failed to consume appropriate amounts from those groups. Although two thirds of the patients ate the recommended number of servings daily from the meat group, only 20% to 31% of the recommended servings from each of the other food groups was consumed. This was possibly related to low socioeconomic status. The patients in the Hb SS group ate significantly less from the bread (P < .037) and milk (P < .022) categories than the patients in the Hb SC group. Fifty-nine percent of families had incomes below the poverty level, and 79% participated in a food assistance program. We conclude that the nutrient intake of patients with sickle cell disease is often inadequate. Education for patients with sickle cell disease should focus on (1) specific nutrient needs, with proper distribution of dietary intake among the food groups, (2) ways to provide nutritious meals on a limited income, and (3) methods for increasing calorie and protein intake.

Adolescent↗
PubMed1997

Neurophysiological correlates of response production and inhibition in alcoholics.

Scalp recordings of the P300 component of the event-related potential were made from a group of medication-free, chronic male alcoholics and a control group, participating in a visual Go/No Go reaction time paradigm. Subjects were presented with large and small forms of the letters T and V. The large forms (Go stimuli) required a button press with either the left or right hand, whereas the small forms (NO Go stimuli) required response inhibition. Recordings were made from 31 electrodes that, for statistical analyses, were grouped into five regions: frontal, central, parietal, occipital, and temporal. The results indicated that, in each of the five regions, both Go and NO Go response amplitudes were larger in the controls than in the alcoholics. No group differences in latency were observed in any region. Surface energy (Wang et al., Brain Topogr. 6:193-202, 1994) magnitudes paralleled P300 amplitudes and in the controls, compared with the alcoholics, were larger during both Go and No Go trials. Our findings suggest that abstinent, chronic alcoholics differ electro-physiologically from control individuals. These differences are manifested as widespread reductions in P300 amplitudes during the performance of a simple information processing paradigm. The reduced amplitudes may reflect a deficiency in an inhibitory mechanism proposed to underlie P300 generation.

Adult↗
PubMed1997

[Genetic divergence of Cordyceps sinensis as estimated by random amplified polymorphic DNA analysis].

Random amplified polymorphic DNA(RAPD) has been used in analyzing 13 winter worm, summer grasses (Cordyceps sinensis [Berk.], Sacc.) from 5 areas in Qingzang plateau. For 19 arbitrary primers, each individual showed about 65 RAPD markers. The genetic distances among those 13 winter worm, summer grasses were correlated to their geographic distances. Molecular phylogenetic tree constructed by UPGMA and NJ suggested that 13 winter worm, summer grasses could be divided into 3 clusters: east cluster, north cluster and middle cluster, in consistence with their origins and genetic divergence among different clusters. Furthermore, our results implied that the RAPD markers of winter worm, summer grasses showed a geographic specificity and could be a better genetic marker in studying genetic diversity and phylogeny of winter worm, summer grasses.

Genetic Variation↗
PubMed1997

[A new karyotype of Drosophila albomicans].

In the paper, we present a new karyotype of D. albomicans found in the populations from Southeast China. Short chromosome IV of D. albomicans has been reported in Thailand populations while long type was discovered in Taiwan populations. However, we found that long and short chromosome IV coexisting in the same somatic cells. The individuals which contained the "hybrid" cells were collected from Shanghai, Fuzhou, Xiamen and Shenzhen, China. Moreover, the three karyotypes could be detected in each population mentioned above in other words, the populations showed a pattern of karyotype polymorphism. Furthermore, our observation disclosed that the new karyotype was unstable. Its frequency decreased with increasing breeding generation. Since the geographic locations of these populations just lies between the regions of double long and double short type's populations, this new karyotype seems a intermediate transitional type during the variance process of D. albomicans.

Animals↗
PubMed1997

Significance probability mapping in 45 patients with lacuna infarct.

OBJECTIVE: To find out the implications of significant probability mapping (SPM) in patients with lacuna infarct. METHODS: Quantitative electroencephalograms (QEEGs) of 45 patients with lacuna infarcts verified by computerized tomography (CT) were compared with mean power of different frequency bands of the healthy control group by Z transform. RESULTS: Thirty patients with one focus of lacuna infarct and 15 patients with multiple foci were verified by CT scan. Thirty patients had focus, and the focal abnormality was found by SPM in 22 cases, but only 5 cases by EEGs (P < 0.05). In multiple lacuna infarcts, focal abnormalities were discovered on SPM in 5 cases. Both general and focal abnormalities in the predominant findings were the increased power of slow frequency band. In 13 cases the focal abnormalities were basically in correspondence with the localization verified by CT scan. CONCLUSIONS: SPM could be helpful in discovering the remote dysfunction of cortex. The sensitivity of SPM was better than the electroencephalogram (EEG) and brain electrical activity mapping (BEAM).

Aged↗