Search PubMed⌕ Search

Biomedical subjects

S Wang

Publications and source records attributed to S Wang.

At least 595 records · Page 33Linked to original sources
PubMed2000

[The analysis of the axises of corneal astigmatism and total astigmatism in astigmatic patients].

PURPOSE: The axial amount and the relationship between the axises of corneal astigmatism and total astigmatism were statistically analyzed in ametropic patients, for the purpose of selecting the refractive correction, the base curve of contact lens, the axis of astigmatic contact lens, and providing the reference of operational amount of ecimer laser keratoplasty. METHODS: The refractive state and the corneal curvature of ametropic patients were measured and consecutvely repeated 3 times in the same eye at the same state with the same autorefractometer in 107 cases. The detected axises of total astigmatism and corneal astigmatism were statistically analyzed through the computerized recording. RESULTS: The mean angle between the axis of corneal astigmatism and the axis of total astigmatism was 5.73 degrees +/- 3.97 degrees in myopic patients, 3.13 degrees +/- 2.49 degrees in mixture astigmatism patients and 6.35 degrees +/- 4.20 degrees in hyperopic patients. CONCLUSION: The angle between the axis of corneal astigmatism and the axis of total astigmatism in the refractive state was mainly caused by the difference of the axises of surface astigmatism of lens and cornea.

Adolescent↗
PubMed2000

[The concentration and expression of IL-5 in human nasal polyp tissue].

OBJECTIVE: To study the concentration and expression of IL-5 in nasal polyp tissues and explore its significance in the micro-environment differentiation of eosinophils accumulation and clarify the conception of nasal polyposis. METHODS: The concentration and expression of IL-5 in nasal polyp tissues of 40 patients were determined by ELISA and immunohistochemistry, and inferior turbinate mucosa from patients with nasal polyps and healthy volunteers was used as control. RESULTS: 1. IL-5 concentration in the polyp tissues was significantly higher than that in inferion turbinate mucosa(P < 0.05). There was no significant difference in inferion turbinate mucosa between the patients with nasal polyps and healthy volunteers (P > 0.05). IL-5 concentration in polyp tissues was markedly higher in patients with extensive polypoid change of nasal mucosa, history of previous polypectomy and allergic rhinitis compared with those without these features (P < 0.05). IL-5 concentration had no correlation with age and sex (P > 0.05). 2. 80.1% of the eosinophils were positive for IL-5 and 90.9% of IL-5 positive cells were eosinophils. Only 3.7% of the lymphocytes and neutrophils were IL-5 positive, and IL-5 was not detectable in epithelial cells. IL-5 expression in eosinophils of polyp tissues was remarkably stronger than that of the turbinate mucosa (P < 0.05). There was no significant difference in inferion turbinate mucosa between the patients with nasal polyps and healthy volunteers (P > 0.05). IL-5 expression of eosinophils in polyp tissues was significantly stronger in patients with extensive polypoid change of nasal mucosa, history of previous polypectomy and allergic rhinitis compared with those without these features (P < 0.05). There was no significant difference in IL-5 expression in lymphocytes and neutrophils between polyp tissues and inferior turbinate nasal mucosa (both P > 0.05). CONCLUSION: IL-5 is a key protein in eosinophilic pathologic mechanisms in nasal polyp tissues.

Adult↗
PubMed2000

[Effect of reperfusion after local ischaemia on the M receptor density in rat brains].

OBJECTIVE: To study the dynamic changes in the density of muscarinic acetylcholine receptor in different areas of rat brains during reperfusion after local ischaemia. METHODS: The rat cerebral focal ischemia/reperfusion model after middle cerebral artery occlusion was made by the intraluminal suture method. Using 3H-QNB as radioligand, after binding with M receptor on the brain slice of the rat model, the brain samples were exposed on the hypersensitive film [H-3] to complete autoradiography, and the density of M receptor in different areas on the film of autoradiography was measured. RESULTS: There were no changes in the M receptor density in 2 hours' ischaemia group and 2 hours' reperfusion group, M receptor densities in the area of occipital cortex (OC) and temporal cortex (TC) were observed to decrease significantly in 8 hours' reperfusion group, but the degree of decrease was lower than 24 hours' and 72 hours' reperfusion groups, there was significant decrease in the density of M receptor in the areas of caudate putamen (CP), frontal cortex (FC), TC, OC of the 24 hours' and 72 hours' reperfusion groups and no difference was found between these two groups, and the imaging of M receptor in the domains with decreased receptor was obvious. CONCLUSIONS: The quantity of M receptor did not change right after ischaemia or reperfusion. It decreased gradually after an interval of time; Imaging of the M receptor could assess the changes of the density of viable cholinergic neurons and be a marker of diagnosis, therapy, and prognosis of brain ischaemia.

Animals↗
PubMed2000

[Surgical treatment of malignant esophageal tumors in PUMC Hospital].

OBJECTIVE: To study how to prolong the postoperative survival time of the patients with malignant esophageal tumors. METHODS: The clinical data of 1,098 patients with malignant esophageal tumors from 1961 to 1992 were retrospectively analyzed. The deletion of fragile histamine triplet(FHIT) gene(a tumor suppressor gene) in 30 fresh esophageal samples obtained in 1996 was detected with PCR and RT-PCR. RESULTS: The resectability was raised gradually and the operative morbidity and mortality decreased year-by-year, but there was no significant improvement on the postoperative 5-year survival rate. Delayed diagnosis and ir-radical resection influenced the long term survival. The deletion of cDNA of FHIT gene was 64.2% in esophageal cancer and 20% in the resected margin of the cancer. CONCLUSIONS: High atypical hyperplasia in esophageal epithelium and deletion of FHIT gene in esophageal cancer and its resected margin are pathological and molecular markers for early diagnosis of esophageal cancer respectively, and the latter may be one of the molecular markers for the resection. Early diagnosis and treatment, radical resection, and postoperative nutritional support are essential for the improvement of the postoperative survival time of the patients.

Acid Anhydride Hydrolases↗
PubMed2000

[Detection of bacterial DNA in blood with three pairs of primers].

OBJECTIVE: To develop a stable and sensitive method to detect gut-derived bacterial DNA present in the blood. METHODS: Blood culture and PCR were performed simultaneously when temperature of patients (n = 23) was higher than 38.5 degrees C after laparotomy. PCR was performed after DNA extraction, target genes being beta-lactosidase gene of Escherichia coli(E. coli), glutamine synthase gene of Bacteroides Fragilitas, and 16SrRNA gene of most pathogenic bacteria. DNA of standard strains of E. coli and Bacteroides Fragilitas served as positive controls, blank control as negative controls, and healthy volunteers (n = 20) served as normal controls. We performed PCR twice with part of the samples (n = 20) in order to test the repetition of this method. RESULTS: The repetition rate of PCR was 95%. Three of blood cultures were positive (13.0%, 3/23), the corresponding positive ratio of PCR was 43.5% (10/23) which was higher than that of the blood culture (P = 0.016). CONCLUSION: PCR is more sensitive than blood culture in detection of bacteremia.

Bacterial Translocation↗
PubMed2000

[Studies on urinary metabolites of perlolyrine in rats].

OBJECTIVE: To study the metabolism of perlolyrine in rats, which is an active ingredient from the traditional Chinese herb, Ligusticum Wallichii Franch. METHODS: After administration of perlolyrine and deuterated perlolyrine, the rat urines were hydrolyzed with glucuronidase, basified with NaHCO3-Na2CO3, extracted with ethyl ether--iso-propyl alcohol. The organic phases (neutral and basic fractions) were concentrated for trimethylsilyl (TMS) derivatives. The aqueous phase were acidified with sulfuric acid, taken to dryness and extracted with methanol (water soluble acidic fractions) and concentrated for TMS derivatives. The TMS derivatives were determined by gas chromatograph mass spectrometry (GC-MS). RESULTS: Perlolyrine and one metabolite were found from the neutral and basic fractions, and two different metabolites were found from the water soluble acidic fractions. CONCLUSIONS: It was proposed that the major metabolic pathways of perlolyrine were that the hydroxylation of perlolyrine and the oxidation of its hydroxylmethyl group.

Animals↗
PubMed2000

[IR and Raman studies of inorganic nano giant cluster compounds].

The syntheses, IR and Raman spectra of four nanosize giant cluster compounds were reported in this paper. These compounds show similar IR and Raman spectra because they were assembled by the similar building blocks. The bands with frequencies in IR spectra in the range from 980 to 550 cm-1 and those absorptions under 970 cm-1 in Raman spectra have to be attributed to the absorptions of Mo-O bonds including Mo = O, Mo-O-Mo and mu 3-O-Mo bonds.

English Abstract↗
PubMed2000

[Sequential injection vapor generation atomic absorption spectrometric determination of mercury and arsenic].

A sequential injection vapor generation atomic absorption spectrometric (SI-VGAAS) method for the determination of mercury and arsenic was developed, characterized by reagent merging using a double-syringe pump and a multi-position selector valve. A sample throughput of 120 h-1 was achieved with 500 microL sample with a precision of 2.2% for mercury at 8.0 micrograms.L-1 (n = 11) and 1.4% for arsenic at 6.0 micrograms.L-1 (n = 11) levels and a detection limit of 0.15 microgram.L-1 for mercury and 0.07 microgram.L-1 for arsenic. The method was applied to the analysis of geochemical standard reference material GSS-5, and good agreement with the certified values were obtained.

Arsenic↗
PubMed2000

[Synthesis and spectroscopic studies of new N-functionalized macrocyclic compounds and complex].

Three new N-functionalized tetraazamacrocyclic compounds, C-messo-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane- N,N',N",N'"-tetrakis (ethyl acetate) (A), C-messo-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetra- azacyclotetradecane-N,N,'N",N'"-tetraacetic acid (H4L) and the hydrobromide of H4L have been synthesized and the complex Na2[NiL].2C2H5OH has been prepared as well. The macroyclic compounds and the complex have been studied by electronic spectrum, infrared spectrum, 1H NMR, MS and elemental analysis.

English Abstract↗
PubMed2000

[Developments in microfluidic spectrometry].

A review is presented on the development of spectrometric detection in microfluidic chemical analysis systems. A brief introduction of microfluidic analysis and future perspectives of the technique are also discussed.

Animals↗
PubMed2000

[Data processing for interferogram of ultraviolet Fourier transform spectrometer].

The method of data processing for interferogram is described in this paper. The interferogram of a mercury lamp has been measured in experiment by means of ultraviolet Fourier Transform Spectrometer in developing. The apodization function that we have chosen is four-term Blackman-Harris window function and a fitting polynomial has been used for phase correction of Fourier Transform spectra based on the least square method. The ultraviolet emission lines of high precision have been obtained by use of this method.

Electronic Data Processing↗
PubMed2000

[Synthesis and characterization of complex Eu (C8H7O3)3.C12H8N2.H2O].

A new complex Eu (C8H7O3)3.C12H8N2.H2O has been synthesized. The complex was deduced tentatively that the Eu (III) ion was chelated by the bidentate ligand 3-methoxybenzoic acid in bridging mode by the characterization of element analysis, molar electric conductance, IR, UV and 1H NMR spectra.

English Abstract↗
PubMed1999

c-Src activates the DNA binding and transcriptional activity of Stat3 molecules: serine 727 is not required for transcriptional activation under certain circumstances.

Stat3 proteins are constitutively activated in cells transformed by v-Src and the proteins have been shown to interact directly. Subsequent studies have shown that Stat3 is required for cellular transformation of NIH fibroblasts by v-Src, suggesting a potential role for Stat3 in aberrant cell growth. Stat3 is phosphorylated on a single tyrosine (tyrosine 705) which is required for effective dimer formation. An additional phosphorylation event (serine 727) is believed to be required for full transcriptional activity of Stat1 and Stat3 molecules. Here we report that c-Src activates the DNA binding activity of Stat3alpha, Stat3beta, and three Stat3 mutants, one in which serine 727 was replaced by alanine (Stat3alphaS727A) and C-terminal truncated molecules Delta48 and Delta55. Consistent with this finding is a general increase in the tyrosine 705-phosphorylated Stat3 in cells cotransfected with c-Src. Furthermore, transcription from an alpha-2 macroglobulin reporter gene is activated by Stat3alphaS727A to the same magnitude as compared to Stat3alpha and Stat3beta in the presence of c-Src. These results suggest that serine 727, contained in a consensus MAP kinase recognition site and shown to be the only serine in Stat3 phosphorylated in epidermal growth factor (EGF) treated cells, is not necessary for transcriptional activity comparable to wild-type Stat3alpha or Stat3beta when activated by c-Src in COS-7 cells.

Amino Acid Sequence↗
PubMed1999

The CD14 ligands lipoarabinomannan and lipopolysaccharide differ in their requirement for Toll-like receptors.

Mammalian Toll-like receptor (TLR) proteins are new members of the IL-1 receptor family that participate in activation of cells by bacteria and bacterial products. Several recent reports indicate that TLR proteins mediate cellular activation by bacterial LPS via a signaling pathway that is largely shared by the type I IL-1 receptor. We previously showed that Chinese hamster ovary (CHO) fibroblasts engineered to express CD14 (CHO/CD14) were responsive to LPS, but not to a distinct CD14 ligand, mycobacterial lipoarabinomannan (LAM). These CHO/CD14 cells were subsequently found to possess a frame-shift mutation within the TLR2 gene which resulted in their inability to express functional TLR2 protein. Thus, we hypothesized that TLR2, but not TLR4, was necessary for LAM signaling. In this paper we show that CHO/CD14 cells engineered to express functional TLR2 protein acquired the ability to be activated by LAM. Similarly, overexpression of TLR2 in murine macrophages conferred enhanced LAM responsiveness. Together, our data demonstrate that the distinct CD14 ligands LAM and LPS utilize different TLR proteins to initiate intracellular signals. These findings suggest a novel receptor signaling paradigm in which the binding of distinct ligands is mediated by a common receptor chain, but cellular activation is initiated via distinct signal-transducing chains that confer ligand specificity. This paradigm contrasts with many cytokine receptor complexes in which receptor specificity is conferred by a unique ligand-binding chain but cellular activation is initiated via shared signal-transducing chains.

Animals↗
PubMed1999

Autosomal XX sex reversal caused by duplication of SOX9.

SOX9 is one of the genes that play critical roles in male sexual differentiation. Mutations of SOX9 leading to haploinsufficiency can cause campomelic dysplasia and XY sex reversal. We report here evidence supporting that SOX9 duplication can cause XX sex reversal. A newborn infant was referred for genetic evaluation because of abnormal male external genitalia. The infant had severe penile/scrotal hypospadias. Gonads were palpable. Cytogenetic analysis demonstrated a de novo mosaic 46,XX,dup(17)(q23.1q24.3)/46, XX karyotype. Fluorescent in situ hybridization (FISH) with a BAC clone containing the SOX9 gene demonstrated that the SOX9 gene is duplicated on the rearranged chromosome 17. The presence of SRY was ruled out by FISH with a probe containing the SRY gene and polymerase chain reaction with SRY-specific primers. Microsatellite analysis with 13 markers on 17q23-24 determined that the duplication is maternal in origin and defined the boundary of the duplication to be approximately 12 centimorgans (cM) proximal and 4 cM distal to the SOX9 gene. Thus, SOX9 duplication is the most likely cause for the sex reversal in this case because it plays an important role in male sex determination and differentiation. This study suggests that extra dose of SOX9 is sufficient to initiate testis differentiation in the absence of SRY. Other SRY-negative XX sex-reversed individuals deserve thorough investigation of SOX9 gene.

Chromosomes, Human, Pair 17↗