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Biomedical subjects

S Wen

Publications and source records attributed to S Wen.

At least 37 records · Page 2Linked to original sources
PubMed2001

Flashlamp-pumped pulsed dye laser in treatment of port-wine stains.

OBJECTIVE: To assess the effectiveness of the flashlamp-pumped pulsed dye laser (Photogeneca V, Synosure Corp, Boston, United States) in the treatment of port-wine stains. METHODS: One hundred and ninety-four consecutive patients with port-wine stains were treated with a flashlamp-pumped pulsed dye laser in Peking Union Medical College Hospital from January 1998 to August 1999. RESULTS: Of 194 patients who completed treatment, 56.2% had more than 60% fading of the lesion and only 6.7% had less than 20% fading. An average of 3.6 treatments were needed to achieve more than 60% fading. The response was better in children than in adults, although the difference was not significant. Pigmentary change (usually transient) occurred in 3.1% of patients. CONCLUSIONS: This study confirms the efficacy of the flashlamp-pumped pulsed dye laser in the treatment of port-wine stains in children and adults.

Adolescent↗
PubMed2000

Enhancement by escins Ib and IIb of Mg(2+) absorption from digestive tract in mice: role of nitric oxide.

The effects of escins Ib and IIb isolated from horse chestnuts on Mg(2+) absorption from the digestive tract and the role of endogenous nitric oxide (NO) were investigated in mice. Test samples were given orally to fasted mice 30, 120, 180, 240 and 300 min before administration of 0.5 M MgSO(4) (10 ml/kg, p.o.). The serum Mg(2+) levels were determined 30, 60, 120 and 180 min after administration of MgSO(4). Escins Ib and IIb (12.5 and 25 mg/kg) significantly increased the serum Mg(2+) by 10.0-27.3%, 30, 120 and 180 min after administration of the samples, and 30, 60, 120 and 180 min after administration of MgSO(4). Escins Ib and IIb (12.5 mg/kg) significantly decreased the Mg(2+) content in the small intestinal fluid in MgSO(4)-loaded mice, but did not increase the serum Mg(2+) levels in normal mice. The effects of escins Ib and IIb (12.5 mg/kg) on serum Mg(2+) levels were attenuated in a dose-related manner by the pretreatment with N(G)-nitro-L-arginine methyl ester (L-NAME, 3-20 mg/kg, i.p., an inhibitor of constitutive and inducible NO synthase), but not with D-NAME (10 mg/kg, i.p., the inactive enantiomer of L-NAME) or dexamethasone (0.05 and 0.5 mg/kg, s.c., an inhibitor of inducible NO synthase). The effect of L-NAME was reversed by L-arginine (600 mg/kg, i.p., a substrate of NO synthase), but not by D-arginine (900 mg/kg, i.p., the enantiomer of L-arginine). These results suggest that escins Ib and IIb enhance Mg(2+) absorption from the digestive tract in mice, in which the constitutive, but not the inducible, NO synthase plays an important role.

Animals↗
PubMed2000

Expression of Fas ligand in arteries of hypercholesterolemic rabbits accelerates atherosclerotic lesion formation.

Fas ligand (FasL) is expressed by cells of the arterial wall and is present in human atherosclerotic lesions. However, the role of FasL in modifying the initiation and progression of atherosclerosis is unclear. To investigate the role of arterial FasL expression in the development of atherosclerosis, we first established a model of primary lesion formation in rabbit carotid arteries. In this model, infusion of adenoviral vectors into surgically isolated, nondenuded arteries of hypercholesterolemic rabbits leads to the formation of human-like early atherosclerotic lesions. Expression of FasL in arterial endothelium in this model decreased T-cell infiltration and expression of vascular cell adhesion molecule-1 but did not affect expression of intercellular adhesion molecule-1. Intimal lesions grew more rapidly in FasL-transduced arteries than in arteries transduced with a control adenovirus that did not express a transgene. Total intimal macrophage accumulation was increased in FasL-transduced arteries; however, the proportion of lesion area occupied by macrophages was not elevated. The accelerated lesion growth was primarily due to the accumulation of intimal smooth muscle cells with a synthetic proliferative phenotype. There was no significant apoptosis in FasL-transduced or control arteries and no granulocytic infiltrates. Thus, the net result of elevated FasL expression is to accelerate atherosclerotic lesion growth by increasing lesion cellularity. Vascular expression of FasL may contribute to the progression of atherosclerosis.

Adenoviridae↗
PubMed2000

Second-generation adenoviral vectors do not prevent rapid loss of transgene expression and vector DNA from the arterial wall.

The utility of adenoviral vectors for arterial gene transfer is limited by the brevity of their expression and by inflammatory host responses. As a step toward circumventing these difficulties, we used a rabbit model of in vivo arterial gene transfer to test 3 second-generation vectors: a vector containing a temperature-sensitive mutation in the E2A region, a vector deleted of E2A, and a vector that expresses the immunomodulatory 19-kDa glycoprotein (gp19k) from adenovirus 2. Compared with similar first-generation vectors, the second-generation vectors did not significantly prolong beta-galactosidase transgene expression or decrease inflammation in the artery wall. Although cyclophosphamide ablated the immune and inflammatory responses to adenovirus infusion, it only marginally prolonged transgene expression (94% drop in expression between 3 and 14 days). In experiments performed with "null" adenoviral vectors (no transgene), loss of vector DNA from the arterial wall was also rapid (>99% decrease between 1 hour and 14 days), unrelated to dose, and only marginally blunted by cyclophosphamide. Thus, the early loss of transgene expression after adenoviral arterial gene transfer is due primarily to loss of vector DNA, is not correlated with the presence of local vascular inflammation, and cannot be prevented by use of E2A-defective viruses, expression of gp19k, or cyclophosphamide-mediated immunosuppression. Adenovirus-induced vascular inflammation can be prevented by cyclophosphamide treatment or by lowering the dose of infused virus. However, stabilization of adenovirus-mediated transgene expression in the arterial wall is a more elusive goal and will require novel approaches that prevent the early loss of vector DNA.

Adenoviridae↗
PubMed2000

[Comparative studies of different carriers and introducing routes on the effects of liver targeted uptake of exogenous gene].

OBJECTIVE: To compare the effects of liposomes and glyco-poly-L-lysine (G-PLL) on target uptake and gene expression of the liver, and to observe the effects of intravenous route and intraperitoneal route on target uptake and gene expression of the liver. METHODS: After encapsulated by liposomes or galactose-terminal glyco-poly-L-lysine, the plasmid which can be expressed in eukaryotic cells was transferred into rat's body by intravenous injection and peritoneal injection respectively, then observed the results in different time by in situ hybridization and immunohistochemistry. RESULTS: The expression of the plasmid encapsulated by liposomes or G-PLL was obvious after transferred in vivo 24 h later, and one week later the expression began to decrease, but still could be found three weeks later. Both liposomes and G-PLL made the liver as the major distribution tissue. In the liver, the distribution and expression of the plasmid encapsulated by G-PLL were higher than those encapsulated by liposomes; in other tissues, however, the distribution and expression of the plasmid encapsulated by G-PLL were lower than those by liposomes. The distribution and expression of the plasmid transferred via intravenous route were higher in the liver than that transferred via intraperitoneal route. CONCLUSION: The effect of G-PLL on liver target uptake and expression is better than that of liposome; The effect of intravenous route on liver target uptake and expression of the plasmid binding to G-PLL is better than that of peritoneal route.

Animals↗
PubMed2000

[Response to milrinone treatment in patients with chronic congestive heart failure].

The objective of this study was to examine the efficacy of milrinone in chronic congestive heart failure. In this randomized, double-blind, placebo-controlled trial, 30 patients with class III or IV chronic congestive heart failure were randomly assigned to receive milrinone (n = 15) or placebo (n = 15). The results showed that in the milrinone group, stroke volume increased from 38.50 +/- 5.34 to 64.93 +/- 6.46 ml (P < 0.001), cardiac output increased from 3.39 +/- 0.42 to 5.28 +/- 0.55 L/min (P < 0.001), cardiac index increased from 2.01 +/- 0.42 to 3.21 +/- 0.57/min/m2 (P < 0.001) and ejection fraction increased from 0.23 +/- 0.05 to 0.35 +/- 0.06(P < 0.001). In the placebo group, no hemodynamic effects were found. Milrinone favourably influenced the symptoms and heart function in 11/15(73.3%) patients. In the placebo group, only 4/15(26.7%) patients had such response (P < 0.05). These data indicate that milrinone is effective for improving the hemodynamics status and heart function in patients with chronic heart failure.

Adolescent↗
PubMed1999

Phenotyping of epidermal dendritic cells: clinical applications of a flow cytometric micromethod.

BACKGROUND: The differential diagnosis of inflammatory skin diseases is largely based on the patient's history and the morphological analysis of the skin lesion. Laboratory data, such as serum IgE-level and prick and patch tests, may be helpful but do not assess individual lesions. The assumption of our approach is that each individual lesion is associated with a specific microenvironment and that the immunophenotype of the two epidermal dendritic cell populations, Langerhans cells (LC) and inflammatory dendritic epidermal cells (IDEC), reflects this environment in a disease-specific manner. METHODS: A flow cytometric micromethod was developed to directly analyze individual inflammatory human skin lesions. Crude epidermal single cell suspensions were prepared by trypsinization, stained for three-color analysis with different monoclonal antibodies and the vital stain 7-amino-actinomycin-D, and finally analyzed on a single laser equipped FACScan flow cytometer. RESULTS: With a limited set of cell surface markers, such as FcepsilonRI, FcgammaRII/CD32, CD1b and CD36, highly specific diagnostic criteria for atopic dermatitis and inflamed human skin could be established. CONCLUSIONS: Phenotyping of epidermal dendritic cells is a useful procedure helpful in differential diagnosis of inflammatory skin diseases.

Antigens, CD1↗
PubMed1999

Structure-related enhancing activity of escins Ia, Ib, IIa and IIb on magnesium absorption in mice.

We examined the effects of the saponin fraction and its principal saponins, escins Ia (1), Ib (2), IIa (3) and IIb (4), obtained from European horse chestnut, and their hydrolyzed products, desacylescins I (5) and II (6) on magnesium absorption from the gastrointestinal tract in mice. Test samples were given orally to fasted mice before loading of 0.5 or 1.67 M MgSO4 (10 mL/kg, p.o.). The saponin fraction (12.5-100 mg/kg) significantly enhanced the Mg2+ absorption 30, 60, 120 and 240 min after administration, with maximum enhancement by 48.3% at 50 mg/kg. Escins Ib (2) and IIb (4) (12.5 and 25 mg/kg) also enhanced the absorption, whereas escins Ia (1) and IIa (3) (12.5 and 25 mg/kg) and desacylescins I(5) and II (6) (25 mg/kg) showed no activity. These results suggested that the 21-O-tigloyl and/or 22-O-acetyl group(s) is essential for such activity. The saponin fraction, 2 and 4 (50 mg/kg) also affected the activity, but their effects were attenuated in streptozotocin-induced diabetic mice. Furthermore, pretreatment with insulin or indomethacin did not reduce the effect of 2 and 4. These results also implied that neither the sympathetic nervous system nor endogenous prostaglandins were involved. The involvement of parathyroid hormone, and/or the metabolism of vitamin D should be considered.

Animals↗
PubMed1999

Discovery of a regulatory motif that controls the exposure of specific upstream cyclin-dependent kinase sites that determine both conformation and growth suppressing activity of pRb.

The conformation and activity of pRb, the product of the retinoblastoma susceptibility gene, is dependent on the phosphorylation status of one or more of its 16 potential cyclin-dependent kinase (cdk) sites. However, it is not clear whether the phosphorylation status of one or more of these sites contributes to the determination of the various conformations and activity of pRb. Moreover, whether and how the conformation of pRb may regulate the phosphorylation of the cdk sites is also unclear. In the process of analyzing the function and regulation of pRb, we uncovered the existence of an unusual structural motif, m89 (amino acids 880-900), the mutation of which confers upon pRb a hypophosphorylated conformation. Mutation of this structural domain activates, rather than inactivates, the growth suppressor function of pRb. In order to understand the effect of the mutation of m89 on the phosphorylation of cdk sites, we identified all the cdk sites (Thr-356, Ser-807/Ser-811, and Thr821) the phosphorylation of which drastically modify the conformation of pRb. Mutation of each of these four sites alone or in combinations results in the different conformations of pRb, the migration pattern of which, on SDS-polyacrylamide gel electrophoresis, resembles various in vivo hypophosphorylated forms. Each of these hypophosphorylated forms of pRb has enhanced growth suppressing activity relative to the wild type. Our data revealed that the m89 structural motif controls the exposure of the cdk sites Ser-807/Ser-811 in vitro and in vivo. Moreover, the m89 mutant has enhanced growth suppressing activity, similar to a mutant with alanine substitutions at Ser-807/Ser-811. Our recent finding, that the m89 region is part of a structural domain, p5, conserved antigenically and functionally between pRb and p53, suggests that the evolutionarily conserved p5 domain may play a role in the coordinated regulation of the activity of these two tumor suppressors, under certain growth conditions.

Amino Acid Sequence↗
PubMed1999

Validity of the right ventricular Doppler index for assessment of severity of congestive heart failure in patients with dilated cardiomyopathy.

This study was designed to clarify the validity of Doppler indices for assessment of the severity of congestive heart failure in patients with dilated cardiomyopathy. Left ventricular (LV) and right ventricular (RV) Doppler indices, defined as the sum of isovolumic contraction time and relaxation time divided by the ejection time, were obtained in 30 normal subjects and 35 patients with ischemic or idiopathic dilated cardiomyopathy. We analyzed the correlation between New York Heart Association (NYHA) functional class, right-sided cardiac pressure, and the Doppler indices. Patients with dilated cardiomyopathy revealed significantly higher LV and RV Doppler indices than normal subjects; however, the LV Doppler index did not correlate significantly with NYHA functional class or right-sided cardiac pressure. On the other hand, the RV Doppler index correlated significantly with NYHA functional class (rs = 0.83, P < 0.001), pulmonary capillary wedge pressure (r = 0.80, P < 0.001), pulmonary artery systolic pressure (r = 0.81, P < 0.001) and pulmonary artery diastolic pressure (r = 0.77, P < 0.001). Both RV isovolumic contraction and relaxation time also correlated significantly with right-sided cardiac pressure. In 12 patients who improved from NYHA III-IV to I-II after treatment, the RV Doppler index decreased from 0.84 +/- 0.25 to 0.33 +/- 0.10 (P < 0.001), while the LV Doppler index did not change significantly (0.72 +/- 0.27 to 0.68 +/- 0.23, P = 0.53). These results suggest that the RV Doppler index is useful for assessment of the severity of congestive heart failure in patients with dilated cardiomyopathy.

Cardiac Catheterization↗
PubMed1999

[Study of transcription and cleavage in vitro of HDV with HBV-specific hammerhead ribozyme].

OBJECTIVE: To study the effect of hepatitis B virus(HBV) specific ribozyme(RZ) and recombinant hepatitis D virus(HDV) inserting hammerhead ribozyme(rHDVRZP and rHDVRZA). METHODS: 831 bp HBV C gene fragment was cloned under the control of T7 promoter, 32P-labeled HBV transcript was incubated with gel-purified RZ, rHDVRZA, rHDVRZP at different temperature and autoradiographed after denaturing gel-electrophoresis. RESULT: These results show that rRZ, rHDVRZA, rHDVRZP were active at 37 degrees C and more so at higher temperatures. CONCLUSION: Recombinant Delt virus could serve as a vector for the delivery of a ribozyme specific for hepatitis B virus cleavage. Our data demonstrate the value of recombinant ribozyme as potential therapeutic agents for treatment of HBV infection. Further study about cleavage in vitro and in vivo will continue.

Cloning, Molecular↗
PubMed1999

[Multivariate analysis of clinical factors in restenosis after coronary interventional treatment].

OBJECTIVE: To found the independent predictors for restenosis after coronary interventional treatment. METHODS: Quantitative angiography was performed in 103 patients(128 successfully dilated lesions) at angioplasty and at 6-month follow-up, and then univariate analysis and multivariate logistic regression analysis were performed to identify correlates of restenosis with clinical factors. RESULTS: The total restenosis rate was 39.8% (51 of 128 lesions). According to univariate analysis, the patients who had undergone coronary tenting > or = 3.5 mm had a lower rate of restenosis(3/29 and 6/30) and the others with the ACC/AHA lesion type B and C(46/51 and 51/77), collateral circulation to the obstruction set(17/51 and 2/77), high percentage diameter stenosis before PTCA(86 +/- 14)% and (79 +/- 15)%, and high maximal inflation pressure(8.3 +/- 2.1) kPa and (7.4 +/- 1.7) kPa had a higher rate of restenosis (P < 0.01). Stable angina showed a low restenosis rate (3/29 and 6/30). The less minimal lumen diameter before(0.43 +/- 0.41) mm and (0.66 +/- 0.43) mm and after PTCA(2.56 +/- 0.55) mm and (2.85 +/- 0.59) mm, had the higher the restenosis rate (P < 0.05). Multivariate logistic regression analysis showed that coronary stenting had a low rate of restenosis, and that lesion type B and C, high percentage diameter stenosis before PTCA, high maximal inflation pressure, and male had a high rate of restenosis. CONCLUSION: Coronary stent, percentage diameter stenosis before PTCA, lesion type, maximal inflation pressure, and sex were independent predictors for restenosis.

Aged↗
PubMed1999

[Effect of antisense oligonucleotides on endothelin converting enzyme expression and endothlin-1 release from airway smooth muscle cells].

OBJECTIVE: To explore the mechanism of TNF-alpha induced ET-1 release and evaluate the effects of endothelin converting enzyme (ECE) antisense oligonucleotides (oDNS) on TNF-alpha induced ET-1 release from airway smooth muscle cells (ASMC). METHODS: ASMC transfected with the antisense oligonucleodides of ECE vectored with lipofectin were established. TNF-alpha induced ECE-mRNA expression and ET-1 release from above cultured cells were determined by RT-PCR and ELISA. RESULTS: ET-1 levels (10.1 +/- 0.3) ng/L and ECE expression (ECE/beta-actin: 0.228 +/- 0.015) in cultured ASMC incubated with 1,000 U/ml TNF-alpha were significantly higher than those in controls without TNF-alpha incubation (7.3 +/- 0.8) ng/L, (0.132 +/- 0.032, all P < 0.01). However, after transfecting antisence ECE-oDNS in those cells, ET-1 levels and ECE expressions were significantly lower than those in control cells without antisense transfection. The inhibition rates were (29 +/- 5)% and (35 +/- 12)% respectively. CONCLUSIONS: Abnormal expression of ECE mRNA may be a keypoint responsible for TNF-alpha induced ET-1 release in human ASMC; TNF-alpha induced ET-1 release and ECE mRNA expression from human ASMC are inhibited by antisense oligonucleotide of ECE.

Aspartic Acid Endopeptidases↗
PubMed1999

[Application of the treatment combined Western and traditional Chinese medicine in idiopathic uveo-encephalitis].

PURPOSE: TO study the factors, which influence idiopathic uveo-encephalitis(IUE) in the occurrence, diagnosis, treatment and prognosis. METHODS: Analysing retrospectively 33 cases of IUE(66 eyes) treated with Combined Western and Traditional Chinese Medicine(CWTCM). The etiology, diagnosis and prognosis were also be discussed. RESULTS: Of the 33 cases, there were 21 cases having the history of eating Xin, Hot, fried food or certain special protein. 15 cases were misdiagnosed. With the therapy of CWTCM, 15 cases recovered completely, 12 cases improved in visual acuity and 6 cases showed no improvement or deterioration. CONCLUSION: Xin, Hot, fried food and certain special protein may interfere with the human immunity, which may be the cause of the IUE in certain patients. Fundus fluorescein angiography is helpful in early diagnosis, the method of CWTCM is a efficient treatment, which values for further investigation.

Adolescent↗
PubMed1998

High resolution electron microscopy investigations of interface and other structure defects in some ceramics.

Interface, grain boundary, and other structure defects are the most important structural factors to affect the properties of ceramics materials. The present paper shows the relationship between the properties and those structure features such as grain boundaries, phase boundaries, interfaces, twins, intergrowths, dislocations, point defect aggregates, order-disorder, and other structure defects in different kinds of ceramics materials. At present this research covers: C60, sialon-based ceramics (alpha-sialon/SiC(w) composite, Y-alpha-sialon/beta-sialon composite), high Tc superconductors (YBa2Cu3O7, YBa2Cu4O8, Bi2Sr2CaCu2O8, Bi2Sr2Ca2Cu3O10), and bioceramics (hydroxyapatite, chlorapatite) and so on. The structure features mentioned above were characterized by high-resolution electron microscopy; so the structure details are at an atomic level and the related physical, chemical, engineering, even biological phenomena can be understood at an atomic and molecular level.

Biocompatible Materials↗
PubMed1998

[The detection of basement membrane and dendritic cells in laryngeal carcinoma].

The state of basement membrane(BM) and dendritic cells(DC) were observed by immunohistochemical methods with the use of anti-laminin antibody, anti-type IV collagen antibody, anti-S-100 protein antibody in 68 cases of laryngeal carcinoma and 21 cases of non-cancer laryngeal tissues. The results showed that among 68 patients with laryngeal carcinoma 39 cases had discontinuous BM. A continuous, linear BM was found mostly in normal larynx, atypia hyperplasia and papilloma, only 3 cases had discontinuous BM. 43 positive DC were detected in 68 cases of laryngeal carcinoma. There were rarely positive DC in non-cancer laryngeal tissues. The poorer the differentiation of carcinoma, the more the discontinuous BM and the lesser the number of DC. The discontinuous BM and DC(-) were seen more in advanced stages of carcinoma. The five-year survival rate in patients with continuous BM was significantly higher than that in patients with discontinuous BM, the five-year survival rate in patients with DC positive was also higher than that in patients with DC negative; the survival rate was highest in patients with continuous BM and DC positive. Our results indicated that the detection of the state of BM and dendritic cells were of value to the prognostic analysis in patients with laryngeal carcinoma.

Adult↗
PubMed1997

Detection of numeric abnormalities of chromosome 17 and p53 deletions by fluorescence in situ hybridization in pleomorphic adenomas and carcinomas in pleomorphic adenoma. Correlation with p53 expression.

BACKGROUND: A fluorescence in situ hybridization (FISH) technique using specific DNA probes allows for the detection of chromosomal aberrations and gene deletions and gains, even in interphase nuclei in human solid tumors. A high frequency of aberrations of chromosome 17 and mutation of the p53 gene have been reported in some human tumors. The correlation of p53 expression with abnormalities of chromosome 17 and p53 gene deletion in salivary gland tumors has not yet been investigated. METHODS: The authors analyzed the numeric aberrations of chromosome 17 and p53 gene deletions in 11 paraffin embedded pleomorphic adenomas (PA) and 9 carcinomas in pleomorphic adenoma (CIPA), using FISH techniques. The centromere specific DNA probe for chromosome 17 and p53 cosmid DNA probe was used. The aberrations of chromosome 17 and p53 deletion were correlated with immunohistochemical detection of p53 protein. RESULTS: Monosomy 17 was detected in 30.8% of CIPA cells and 29.6% of PA cells, and polysomy 17 was detected in 19.6% of CIPA cells and 9.6% of PA cells. p53 protein expression was observed in 6 of 9 CIPA specimens (66.7%) and 2 of 75 PA specimens (2.7%). Deletion of the p53 gene was frequent in p53 protein positive specimens. A statistically significant correlation existed between p53 protein expression and polysomy 17 (P = 0.0417). CONCLUSIONS: It was observed that loss of chromosome 17 may occur in PA before its transformation to carcinoma. p53 expression was frequently associated with deletion of the p53 gene as detected by FISH. Polysomy 17 was more frequent in CIPA than PA and was associated with mutation of p53.

Adenocarcinoma↗