Search PubMed⌕ Search

Biomedical subjects

S Yuan

Publications and source records attributed to S Yuan.

At least 91 records · Page 5Linked to original sources
PubMed1999

[The changes in arteriography in extremities sustaining high tension electric injuries].

OBJECTIVE: Because it is difficult to estimate the extent and degree of damage to the blood vessels of extremities sustaining high tension electrical injuries, arteriography was carried out to evaluate the vascular changes. METHODS: Selective arteriography was carried out 29 times for 26 extremities in 17 patients suffering from > 380 V electrical injuries. RESULTS: The arteriography showed that the injured arteries were narrowed and occluded, and vascular branches decreased or disappeared. Recanalization of the partially occluded arteries or collateral circulation formation was found after decompression. CONCLUSION: Arteriography is valuable to evaluate the vascular changes in high tension electrical injuries of extremities.

Adolescent↗
PubMed1999

The change of insulin-like growth factor-1 in diabetic patients with neuropathy.

OBJECTIVE: To evaluate the possible relationship between insulin-like growth factor-1 (IGF-1) and diabetic neuropathy (DNP). METHODS: Sixty-nine patients with Type 2 non-insulin-dependent diabetes (54 with peripheral neuropathy and 15 without neuropathy) were observed. Normal controls were 34 non-diabetic persons. Diabetic peripheral neuropathy diagnosis was carried out taking into account results of NS, ND, NC and AF. After an overnight fast, blood was taken for IGF-1, glucose, hemoglobin Alc, C-peptide, and insulin. Plasma IGF-1 was measured by radioimmunoassay (RIA) method. RESULTS: The neuropathic group had significantly lower levels for IGF-1 (86.43 ng/ml +/- 45.18 ng/ml) compared to normal controls (119.68 ng/ml +/- 89.42 ng/ml) (P < 0.05), and to diabetic patients without neuropathy (113.75 ng/ml +/- 66.58 ng/ml) (P < 0.05). No significant difference was found between diabetic non-neuropathic group and normal control subjects (P < 0.05). In diabetic subjects there was a positive correlation (gamma = 0.27, P < 0.05) between IGF-1 and beat to variation in heart rate. There were negative correlation between IGF-1 and postprandial blood glucose (gamma = -0.3, P < 0.05), and aspartic acid translocase (gamma = -0.27, P < 0.05). CONCLUSION: In diabetic patients with peripheral neuropathy there are abnormalities of IGF-1 that may contribute to the pathogeneses of diabetic neuropathy.

Aged↗
PubMed1999

[The relationship between ophthalmic nerve lesion in glaucoma and ocular and systemic haemodynamic disturbance].

OBJECTIVE: To explore the relationship between the optic nerve lesion in glaucoma and ocular and systemic haemodynamic disturbance. METHODS: The color Doppler imaging was used to study blood velocity in the ophthalmic, the central retinal and the short posterior ciliary arteries in 34 patients with primary open angle glaucoma, 31 patients with low tension glaucoma and 90 healthy controls. The peak systolic velocity(PSV), the end diastolic velocity (EDV) and resistive index (RI) in each artery were measured, moreover the nailfold microcirculation and blood viscosity in each patient were examined. RESULTS: Compared with the control group, the PSV and EDV of the central retinal arteries were significantly lower while the RI of the central retinal arteries was significantly higher in both POAG and LTG patients. The RI of the short posterior ciliary arteries however was significantly higher in POAG. Nailfold microcirculation shows that some important parameters, including flow pattern, loop surrounding, morphological weighted value, total weighted value and capillary deformity rate in the two glaucoma groups were higher, whereas the flow velocity was lower than in the control group. The plasm viscosity and the whole blood viscosity (low spear) were higher than normal. According to our measurements, the nailfold microcirculation and blood viscosity was worse at the end stage of glaucoma than at early stage. The correlative analysis between measurement results of color doppler imaging and microcirculation and heamorrheology showed that nailfold microcirculation morphological weighted value was negatively correlated with the EDV of the central retinal artery and positively correlated with the RI of the central retinal artery in LTG patients. CONCLUSIONS: The abnormity of ocular haemodynamics and systemic microcirculation and blood viscosity is one important factor of optic nerve damage in glaucoma.

Adolescent↗
PubMed1999

[Study of the relation between mutant gene in bile and hepatic metastasis of large intestinal carcinoma].

OBJECTIVE: To study the value of point mutant genes in the diagnosis of hepatic metastasis of large intestinal carcinoma. METHODS: Techniques of PCR-SSCP and DNA sequencing were used to detect point mutations of p53 and k-ras genes in primary focus, hepatic metastatic focus, and bile. RESULTS: 50 cases of large intestinal cancer were detected. 38 cases (76.0%) had p53 and k-ras gene mutations. p53 gene mutations were detected in 28 cases (56.0%) and k-ras gene mutations in 16 cases (32.0%). The same point mutant genes in bile with primary focus were detected in 10 out of 12 patients with hepatic metastasis (83.3%). CONCLUSIONS: The tumor cells of hepatic metastasis show the same clonal origin with primary focal cells that had same point mutant genes. Detection of the point mutant genes in bile is of value in the diagnosis of hepatic metastasis of large intestinal carcinoma.

Bile↗
PubMed1999

[Clinical and pathological analysis in 327 cases with renal biopsy].

The renal biopsy results of 372 cases are summarized in this article. Definite pathological diagnoses were made in 354 cases, among which most cases were of mesengioproliferative glomerulonephritis type (27.1%), followed by glomerulopathy type with minimal change(12.4%). The association between clinical manifestation and pathological change was discussed. The data indicate that renal biopsy plays pivotal role in confirming the clinical diagnosis and guiding treatment.

Adolescent↗
PubMed1999

[Effect of benazepril on renal interstitial inflammatory cell infiltration in rats with unilateral ureteral obstruction].

Effect of benazepril on renal interstitial inflammatory cell infiltration was observed in rats with unilateral ureteral obstruction(UUO). The results showed that the relative volume of interstitium and number of infiltrating inflammatory cell on the fifth day were significantly less in rats with benazepril than the control group, but the difference between two groups lose significance on the tenth day. These data indicate that benazepril can ameliorate early phase of renal interstitial inflammation in UUO.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1999

[Comprehensive evaluation and practical confirmation on processing technology of Daphne genkwa Sieb. et Zucc].

OBJECTIVE: To investigate the effect of five processing methods for D. genkwa. METHOD: Comparing the pharmacodynamic and toxic parameters and related chemical constituents of the processed products with those of crude D. genkwa and vinegar-processed D. genkwa recorded in Chinese Pharmacopoeia. THE RESULT: The vinegar stir-fry method was the best. One hundred kilograms of crud D. genkwa was evenly mixed with 30 kg vinegar diluted in 60 kg water and moistened in a closed container for an hour, then put into a drug-parching machine to get nearly dry with slow fire wenhuo and taken out timely. CONCLUSION: Three repetitions of pilot production have shown that the technology is simple, easy to operate and of good reproducibility, and thus can be used in the production of D. genkwa in slice form.

Acetic Acid↗
PubMed1999

[High-level expression of human acidic fibroblast growth factor in E. coli and its purification].

A reconstructed human acidic fibroblast growth factor (haFGF) cDNA was cloned into the expression vector pkk223-3, and the expression in Escherichia coli. JM109 was induced by IPTG induction; the expression level of the recombinant haFGF was about 80 mg/L. The expressed haFGF was purified to identity by heparin affinity chromatography and the recovery rate of haFGF was 65%. The specific activity of the purified haFGF was ED50 4.6 ng/ml. The characters of recombinant haFGF was identical to that of natural one.

Cloning, Molecular↗
PubMed1999

[Comparative study of dependence of the cell proliferation of Saccharomyces cerevisiae and Schizosaccharomyces pombe on Ca2+].

Under the same experimental conditions, exogenous Ca2+ had no effect on the proliferation of S. cerevisiae, but it could obviously stimulate the proliferation of S. pombe. Ca2+ chelator EGTA had no inhibition effect on the proliferation of S. cerevisiae, but it apparently inhibited the proliferation of S. pombe and the inhibition could be effectively overcome by adding Ca2+. Non-special ion chelator EDTA could inhibit the proliferation of both S. cerevisiae and S. pombe, but the inhibition could not be overcome by adding Ca2+. The results above directly showed that the dependence of the proliferation of the two kinds of yeast on exogeneous Ca2+ was different. The growth rate of S. cerevisiae was about 3 times that of S. pombe and the proliferation of S. cerevisiae was independent on the exogenous Ca2+, which was similar to transformed cells. Therefore, in order to understand the relationship between the disorder of cell cycle and cell transformation, it was very important to study the mechanism of different effects of exogenous Ca2+ on the proliferation of the two kinds of yeast.

Calcium↗
PubMed1999

[Study on the action force of dimerization of cobalt tetrasulfonate Ph-thalocyanine in aqueous solotion].

The dimerization of cobalt tetrasulfonate phthalocyanine (CoTSPc) was studied in the microemulsion, micelles and aqueous alcoholic solutions. The coordination reaction for the formation of complexes CoTSPc (L), which was formed by cobalt tetrasulfonate phthalocyanine (CoTSPc) plus ligand L(L = NH3, CN-, en), was also studied. The reaction kinetics was discussed and the stability constant K of CoTSPc(L)2 was also calculated from absorbance measurement.

English Abstract↗
PubMed1999

[Dimerization of aluminum, zinc, vanadium and gallium phthalocyanine-sulfonates in water, aqueous alcoholic solutions and micelles].

The dimerization of Aluminum (III),Vanadium(lV), Gallium(III) tetrasulfonated phthalocyanine (AlTSPc, VOTSPc, GaTSPc) and Zinc(II) bisulfonated phthalocyanine (ZnBSPc) was studied by spectrophotometic method. The dimerization constants KD were calculated from absorbance measurements. The absorption spectra in water, aqueous alcoholic solutions and micelles of phthalocyanine sulfonates aluminum shows the "slow-forming dimer", and VOTSPc, GaTSPc, ZnBSPc show contact dimer formation.

English Abstract↗
PubMed1998

Comparative studies on genotoxicity and antigenotoxicity of natural and synthetic beta-carotene stereoisomers.

To evaluate the practical value of natural beta-carotene (NbetaC) and to elucidate the apparent discrepancy between epidemiological observations and intervention trials on the role of beta-carotene (betaC) in tumor prevention, the genotoxicity and the antigenotoxicity of NbetaC and synthetic betaC crystal (SbetaCC) stereoisomers were studied comparatively using chromosome aberration analysis and the micronucleus test in human lymphocytes in vitro. NbetaC was extracted from the halotolerant algae Dunaliella salina. The NbetaC crystal (NbetaCC) preparation is about 70% all-trans (TbetaC) and 8% 9-cis (CbetaC). The NbetaC oil (NbetaCO) preparation is about 40% all-trans and 38% 9-cis. SbetaCC is more than 97% all-trans, and the 9-cis can not be detected. The mixture of betaC (betaCM) preparation is 74% SbetaCC and 26% NbetaC. Our results show no genotoxicity of 1-30 microg/ml NbetaCC, but this concentration of NbetaCC inhibited significantly gamma-ray-induced micronucleus formation in human lymphocytes in vitro. One to thirty microg/ml NbetaCO was most effective against both gamma-ray-induced and spontaneous micronucleus formation. However, no influence of NbetaCO on spontaneous chromosome aberrations in human lymphocytes in vitro was observed. NbetaCO suppressed significantly mitomycin C (MMC)-induced chromosome aberrations. One to thirty microg/ml SbetaCC induced a dose-dependent increase in micronucleus frequency, and also inhibited gamma-ray-induced micronucleus formation. No effect of betaCM on spontaneous chromosome aberrations was found. One to thirty microg/ml betaCM is more effective against MMC-induced chromosome aberrations than NbetaCO. These results suggest that CbetaC might play a critical role in the genotoxicity and antigenotoxicity of SbetaCC and NbetaC. The genotoxic activity of SbetaCC might be involved in carcinogenesis. NbetaC or betaCM could be of practical value in tumor prevention and supplementary treatment.

Adolescent↗
PubMed1998

The non-permissive infection of insect (gypsy moth) LD-652 cells by Vaccinia virus.

The members of Poxviridae family are among the most complex of animal viruses and subfamily members infect both vertebrate (Chordopoxvirinae) and invertebrate (Entomopoxvirinae) hosts, respectively. Vaccinia virus (VV) is the most commonly studied vertebrate virus and the entomopoxvirus of Amsacta moorei (AmEPV) is the prototypic insect virus. AmEPV, while not able to productively infect vertebrate cells, does enter vertebrate cells and expresses early genes after which the infection aborts although the cells survive (Y. Li, R. L. Hall, and R. W. Moyer. J.Virol. 71(12), 95579562, 1997). We show here that a recombinant VV, containing the lacZ gene regulated by the cowpox virus A-type inclusion (ATI) late promoter, likewise does not productively infect insect cells. Our results suggest that the recombinant VV enters insect cells, host protein synthesis is inhibited, early gene expression is normal, and viral DNA replication occurs as does late protein synthesis. However, little if any proteolytic processing of late viral proteins, typical of morphogenesis, is observed. Electron micrographs of infected cells suggest that while cytoplasmic virosomes (factories) are formed, there is little indication of further morphogenesis or any formation of mature virions. Therefore, while both orthopoxviruses and entomopoxviruses fail to replicate in heterologous hosts, the nature of abortive infections is quite different.

Animals↗
PubMed1998

Neuronal pathways and transmission to the lower esophageal sphincter of the guinea Pig.

BACKGROUND & AIMS: The lower esophageal sphincter (LES) normally controls the opening and closing of the gastroesophageal junction to resist gastric reflux but allow swallowing. Neuronal pathways controlling the guinea pig LES were investigated anatomically and physiologically in isolated preparations. METHODS: Intracellular recording from the LES with focal electrical stimulation and retrograde and anterograde neuronal tracing were used. RESULTS: Electrical stimulation on the LES evoked inhibitory junction potentials (IJPs), which were reduced by 60% by 100 micromol/L N-nitro-L-arginine and subsequently blocked by 0.5 micromol/L apamin, unmasking excitatory junction potentials, which were abolished by 1 micromol/L hyoscine. Esophageal or vagal stimulation evoked IJPs, which were blocked by 100 micromol/L hexamethonium. Focal stimulation of the upper stomach evoked IJPs at 5-8 of 20 stimulation sites, which were abolished by cutting between the stimulation site and sphincter. Application of 1,1'-didodecyl-3,3,3', 3'-tetramethyl indocarbocyanine perchlorate (DiI) to the gastric sling muscle anterogradely labeled many motor axons in the sling muscle but few in the LES, confirming that the two muscles are separately innervated. DiI on the esophagus labeled nerve fibers, but not cell bodies, in the upper stomach. CONCLUSIONS: The inhibitory motor neurons of the LES receive inputs from the vagus nerve, esophagus, and upper stomach.

Animals↗
PubMed1998

TCRBV14S1 and rheumatoid arthritis revisited: abnormalities in the percentage of transcribed TCRBV14S1 family genes in PBMC from rheumatoid arthritis patients.

The purpose of this study was to identify Vbeta gene families that are associated with rheumatoid arthritis (RA). A PCR-based assay was used to compare the Vbeta repertoire of unstimulated PBMC from 18 RA patients and 18 matched controls. The influence of an HLA-DRB1-binding peptide (HA307-319) on the Vbeta repertoire of PBMC in culture was compared in 11 RA patients and 10 controls. There was a larger variance in the percentage of BV14S1 transcripts in unstimulated PBMC from RA patients than from controls (p = 0.0003). The mean percentage of BV14S1 transcripts was higher in RA patients when prednisone-treated RA patients were excluded from the analysis (p = 0.0006). In vitro stimulation with the HA307-319 peptide increased the percentage of BV14S1 transcripts in PBMC from RA patients (+ 1.5 +/- 0.4%, p < 0.005) but not controls (+ 0.3 +/- 0.2%, ns), and the difference between RA patients and controls was significant (p = 0.03). In conclusion, there is an association between RA and the BV14S1 gene family in New Zealand patients.

Arthritis, Rheumatoid↗
PubMed1998

Shear stress activates p60src-Ras-MAPK signaling pathways in vascular endothelial cells.

The aim of this study was to elucidate the upstream signaling mechanism that mediates the fluid shear stress activation of mitogen-activated protein kinases (MAPKs), including c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinases (ERKs), in vascular endothelial cells (ECs). Our results indicate that p60src is rapidly activated by fluid shear stress in bovine aortic endothelial cells (BAECs). Shear stress induction of the hemagglutinin (HA) epitope-tagged HA-JNK1 and the Myc epitope-tagged Myc-ERK2 was significantly attenuated by v-src(K295R) and c-src(K295R), the kinase-defective mutants ofv-src and c-src, respectively. HA-JNK1 and Myc-ERK2 were activated by c-src(F527), a constitutively activated form of p60src, and the activation was abolished by RasN17, a dominant-negative mutant of p2lras. In contrast, although HA-JNK1 and Myc-ERK2 were also activated by RasL61, an activated form of p21ras, the activation was not affected by v-src(K295R). These results indicate that p60src is upstream to the Ras-JNK and Ras-ERK pathways in response to shear stress. The shear stress inductions of the promoters of monocyte chemotactic protein-1 (MCP-1) and c-fos, driven by TPA-responsive element (TRE) and serum-responsive element (SRE), respectively, were attenuated by v-src(K295R). This attenuation is associated with decreased transcriptional activities of c-Jun and Elk-1, the transcription factors targeting TRE and SRE, respectively. Thus, p60src plays a critical role in the shear stress activation of MAPK pathways and induction of Activating Protein-1 (AP- 1)/TRE and Elk-1/SRE-mediated transcription in ECs.

Animals↗