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Biomedical subjects

Wen Chen

Publications and source records attributed to Wen Chen.

At least 55 records · Page 3Linked to original sources
PubMed2005

[Abnormalities of microsatellite in transitional cell carcinoma of urinary bladder related with aromatic amine exposure].

OBJECTIVE: To study the microsatellite abnormalities of the aromatic amine exposure-associated transitional cell carcinoma (TCC) and sporadic TCC of urinary bladder, and to evaluate the potential of microsatellite analysis on detection of this diseases. METHODS: Based on our previous investigations, 5 microsatellite markers (D17S695, D9S162, D3S1295, DBH and D3S1234) that had high frequencies of loss of heterozygosity (LOH) in sporadic TCC, were selected for analysis with the bladder lesions derived from 16 patients with aromatic amine exposure history. The microsatellite analysis with urine sediments from the post-operated patients was also carried out. RESULTS: There was at least one informative marker out of the 5 microsatellite foci showed polymorphism in the DNA derived from 16 patients examined. Within 87.50% (14/16) patients, LOH was detected in the bladder lesions at least with one microsatellite marker. The LOH frequency of D3S1295 was higher in occupational TCC patients than that in sporadic TCC patients. The diagnostic accordance rate of patients showed LOH in at least one microsatellite marker with patients diagnosed by pathology was 81.25% (13/16). In the urine sediments from 8 TCC post-operated patients, LOH was found at least with one microsatellite marker. CONCLUSION: There could be a different LOH pattern in aromatic amine exposure-associated TCC, and genes near D3S1295 might play a role in the occupational exposure-associated TCC.

Carcinoma, Transitional Cell↗
PubMed2005

[Clinical observation and mechanism study on acupuncture combined with massage for treatment of vertebrobasilar insufficiency].

OBJECTIVE: To search for the best program increasing clinical therapeutic effect on vertebrobasilar insufficiency (VBI) and to study the mechanism. METHODS: The patients were randomly divided into an acupuncture plus massage group, an acupuncture group and a massage group. Their therapeutic effects were observed and compared. And transcranial Doppler (TCD) was used for detection of systolic flow velocity (Vs), enddiastolic peak flow velocity (Vd), mean peak flow (Vm) and pulsatility index (PI) before and after treatment. RESULTS: The cured rate and the total effective rate in the acupuncture plus massage group were significantly higher than the acupuncture group and the massage group (P < 0.05). And there were significant differences in Vm, PI and DI in the left vertebral artery (LVA), the right vertebral artery (RVA) and the basilar artery (BA) before and after treatment (P < 0.01). CONCLUSION: Acupuncture combined with massage can improve Vm, PI, DI of VA-BA and the clinical therapeutic effect on VBI as well. It is superior to the simple acupuncture therapy and simple massage therapy. At present, it is one of the best therapy for VBI.

Acupuncture Therapy↗
PubMed2005

[Optimum selection of acupuncture treatment programs of cerebral infarction and its effects on insulin resistance].

OBJECTIVE: To study the optimum acupuncture treatment program and the mechanism for treatment of cerebral infarction. METHODS: Sixty-three cases were randomly divided into 9 groups. The four factors, times of manipulation, the retaining time of the needle, acupuncture instrument and acupoints,and their corresponding three levels were adopted respectively in treatment of each group. Then nerve function defect score and insulin resistance were observed before and after treatment. RESULTS: The acupoints, the times of manipulation and the retaining time of the needle have significant effects on nerve function defect and insulin resistance (P < 0.01 or P < 0.05), and the acupuncture instrument has a significant effect on insulin resistance (P < 0.01). The choice of acupoints was the most important factor for acupuncture treatment of cerebral infarction. CONCLUSION: Acupuncture for regulating The Governor Vessel with twice manipulations and retaining the needle for 60 min is optimum treatment program for cerebral infarction. The good regulating effect of acupuncture on insulin resistance is one of the mechanisms of achieving the therapeutic results.

Acupuncture Points↗
PubMed2005

[Autologous buccal mucosal graft pre-transplantation for urethral reconstruction of complicated hypospadias].

OBJECTIVE: Applicate autologous buccal mucosal graft pre-transplantation for urethral reconstruction of complicated hypospadias by staging. METHODS: From 1999 to 2003, 40 patients have been treated by method of autologous buccal mucosal graft pre-placing. There were two models: graft onlay and graft-tube for urethral reconstruction, and the 2rd operation was accomplished half year later. RESULTS: All patients healed without urethral fistula. CONCLUSION: The method is valuable for treatment of complicated hypospadias.

Adolescent↗
PubMed2004

[Expression of Survivin in transitional cell carcinoma of urinary bladder and its clinical significance].

OBJECTIVE: Survivin is a member of the inhibitors of apoptosis protein (IAP) family. Recent researches had shown that survivin plays an important role in oncogenesis. This study was designed to investigate the expression of survivin in transitional cell carcinoma (TCC) of urinary bladder and its clinical significance. METHODS: Immunohistochemical assay was used to detect the expression of survivin in 75 cases of tumor tissue and 7 cases of normal bladder tissue. RESULTS: The expression rates of survivin were 77.3% (58/75) in TCC of urinary bladder, whereas no expression of survivin was detected in the 7 cases of normal bladder tissue. CONCLUSIONS: Expression of survivin protein was observed in the tumor tissue derived from the patients with bladder TCC, indicating that this protein may play an important rule in carcinogenesis of human urinary bladder. The expression of survivin was statistically significant associated with tumor grade. Our results suggested that the expression of survivin may be considered as a prognostic factor for bladder TCC.

Adult↗
PubMed2004

Signaling and transcriptional changes critical for transformation of human cells by simian virus 40 small tumor antigen or protein phosphatase 2A B56gamma knockdown.

One set of genes sufficient for transformation of primary human cells uses the combination of Ha-Ras-V12, the telomerase catalytic subunit hTERT, SV40 large tumor antigen (LT), and SV40 small tumor antigen (ST). Whereas SV40 LT inactivates the retinoblastoma protein and p53, the contribution of ST is poorly understood. The essential helper function of ST requires a functional interaction with protein phosphatase 2A (PP2A). Here we have identified changes in gene expression induced by ST and show that ST mediates these changes through both PP2A-dependent and PP2A-independent mechanisms. Knockdown of PP2A B56gamma subunit can substitute for ST expression to fully transform cells expressing LT, hTERT, and Ras-V12. We also identify those genes affected similarly in two cell lines that have been fully transformed from a common parental line by two alternative mechanisms, namely ST expression or PP2A B56gamma subunit knockdown. ST altered expression of genes involved in proliferation, apoptosis, integrin signaling, development, immune responses, and transcriptional regulation. ST reduced surface expression of MHC class I molecules, consistent with a need for SV40 to evade immune detection. ST expression enabled cell cycle progression in reduced serum and src phosphorylation in anchorage-independent media, whereas B56gamma knockdown required normal serum levels for these phenotypes. Inhibitors of integrin and src signaling prevented anchorage-independent growth of transformed cells, suggesting that integrin and src activation are key ST-mediated events in transformation. Our data support a model in which ST promotes survival through constitutive integrin signaling, src phosphorylation, and nuclear factor kappaB activation, while inhibiting cell-cell adhesion pathways.

Antigens, Polyomavirus Transforming↗
PubMed2004

Site-selective DNA hydrolysis by combining Ce(IV)/EDTA with monophosphate-bearing oligonucleotides and enzymatic ligation of the scission fragments.

By using two oligonucleotide additives that bear a monophosphate group at the termini through various linkers, gap structures were formed at predetermined positions in substrate DNA, and the monophosphate groups were placed at both edges of these gaps. At pH 7.0 and 37 degrees C, the phosphodiester linkages in the gap sites were efficiently and selectively hydrolyzed by Ce(IV)/EDTA complex (EDTA = ethylenediamine-N,N,N',N'-tetraacetate). The linkages in the middle of the gaps were predominantly hydrolyzed. Compared with DNA scission using oligonucleotide additives that bear no terminal monophosphate, the present scission was much faster (22-fold for a 3-base gap and 14-fold for a 5-base gap) and more site selective. Introduction of one monophosphate group to either edge of the gaps was also effective for promotion of both site selectivity and scission rate. The monophosphate group(s) at the gap site recruits the Ce(IV) to the target site and magnifies the difference in intrinsic reactivity between the target site and the others. Even at higher reaction temperatures, the site selectivity remained satisfactorily high. Furthermore, the fragments formed by the site-selective scission were connected with various oligonucleotides by using DNA ligase, producing desired recombinant DNAs.

Base Sequence↗
PubMed2004

The effect of taurine on cholesterol degradation in mice fed a high-cholesterol diet.

The hypocholesterolemic effect of taurine was examined in mice fed a high-cholesterol diet containing 1% cholesterol and 0.25% sodium cholate. Male C57BL/6 mice were divided into 3 groups: control group (HC), 1% taurine-supplemented group (HCT+), and taurine-deficient group (HCT-) produced by supplying 0.5% guanidinoethyl sulfonate (GES) solution ad libitum instead of water. After they were fed with the respective diet or drinking water for 4 weeks, the liver taurine level was reduced 80% in the HCT- group compared with that in the HC group, although there was no difference in the serum taurine amount between the two groups. The formation ratio of cholesterol gallstones increased from 71% to 100% by taurine deficiency, and decreased to 0% by taurine supplementation. Compared with the HC group, serum and liver cholesterol significantly decreased, and the excretion of fecal bile acid notably rose in the HCT+ group but tended to lower in the HCT- group. There were no differences in LDL receptor protein level among the three groups. In the subsequent experiment, triglycerides (TG) secretion rate was determined and found to be significantly suppressed by taurine supplementation. In conclusion, it is suggested that taurine does not up-regulate LDL receptor protein level, and the decrease in cholesterol in the circulation is mainly due to its suppressive effect on TG secretion from the liver.

Analysis of Variance↗
PubMed2004

Human MUC1 carcinoma-associated protein confers resistance to genotoxic anticancer agents.

The MUC1 transforming protein is overexpressed by most human carcinomas. The present studies demonstrate that the MUC1 C-terminal subunit (MUC1 C-ter) localizes to mitochondria in HCT116/MUC1 colon carcinoma cells and that heregulin stimulates mitochondrial targeting of MUC1 C-ter. We also show that MUC1 attenuates cisplatin-induced (1) release of mitochondrial apoptogenic factors, (2) activation of caspase-3, and (3) induction of apoptosis. Moreover, knockdown of MUC1 expression in A549 lung and ZR-75-1 breast carcinoma cells by MUC1siRNA was associated with increased sensitivity to genotoxic drugs in vitro and in vivo. These findings indicate that MUC1 attenuates the apoptotic response to DNA damage and that this oncoprotein confers resistance to genotoxic anticancer agents.

Antigens↗
PubMed2004

Identification of specific PP2A complexes involved in human cell transformation.

The SV40 small t antigen (ST) interacts with the serine-threonine protein phosphatase 2A (PP2A). To investigate the role of this interaction in transformation, we suppressed the expression of the PP2A B56gamma subunit in human embryonic kidney (HEK) epithelial cells expressing SV40 large T antigen, hTERT, and H-RAS. Suppression of PP2A B56gamma expression inhibited PP2A-specific phosphatase activity similar to that achieved by ST and conferred the ability to grow in an anchorage-independent fashion and to form tumors. Overexpression of PP2A B56gamma3 in tumorigenic HEK cells expressing ST or human lung cancer cell lines partially reversed the tumorigenicity of these cells. These observations identify specific PP2A complexes involved in human cell transformation.

Animals↗
PubMed2004

Manipulation of DNA through Ce(IV)/EDTA-induced site-selective hydrolysis using phosphate-bearing oligonucleotides.

By using two oligonucleotides bearing a monophosphate group at the terminus and placing them at both edges of gap-site formed in substrate DNA, this site was preferentially and efficiently hydrolyzed by Ce(IV)/EDTA. In this study, site-selective hydrolysis of gap-site in long substrate DNA (274-mer) was investigated. When two monophosphate groups were placed to both edges of 5-base gap, predetermined site was selectively hydrolyzed by Ce(IV)/EDTA. Furthermore, desired recombinant DNA was prepared from this fragment and foreign DNA using T4 DNA ligase.

Cerium↗
PubMed2004

Vulvar keratoacanthoma: a report of two cases.

Keratoacanthomas are commonly encountered by dermatopathologists and general pathologists, and usually present as a rapidly growing crateriform lesion on sun exposed skin of the elderly. Because of its rarity in the vulva, this lesion can be mistaken for a malignant lesion, specifically the much more common squamous cell carcinoma. We report two cases of vulvar keratoacanthomas at our institution, one of which was initially diagnosed as a squamous cell carcinoma. Both patients are free of disease after follow-up of 14 and 138 months. Awareness of the occurrence of keratoacanthoma at this site and attention to its characteristic features will help avoid its misdiagnosis as squamous cell carcinoma.

Adult↗
PubMed2004

[Study on the mechanism of oocyte aneuploidy formation by multicolor fluorescence in situ hybridization].

OBJECTIVE: To investigate the mechanism of oocyte aneuploidy formation. METHODS: The unfertilized oocytes were fixed 1-3 days after oocyte retrieval. Multicolor fluorescence in situ hybridization (M-FISH) was performed according to the Vysis protocol to check the chromosome status in oocytes by using centromeric enumerator probes for chromosomes 16, 18 and locus-specific probes for chromosomes 13, 21 and 22. RESULTS: 47% oocytes were found to be normal, while 53 % oocytes were abnormal. Nondisjunction was found in 22(18%) oocytes, unbalanced predivision of chromatids in 15(12%) oocytes, balanced predivision of chromatids in 45(36%) oocytes. The balanced predivision rate in oocytes aged in vitro>24h was much higher than that in oocytes aged in vitro<or=24h (P<0.01). CONCLUSION: Both nondisjunction, balanced and unbalanced predivision of chromatids are involved in the oocyte aneuploidy formation. Balanced predivision is related to the time in culture.

Adult↗
PubMed2003

Fluorescence excitation-emission matrix regional integration to quantify spectra for dissolved organic matter.

Excitation-emission matrix (EEM) fluorescence spectroscopy has been widely used to characterize dissolved organic matter (DOM) in water and soil. However, interpreting the > 10,000 wavelength-dependent fluorescence intensity data points represented in EEMs has posed a significant challenge. Fluorescence regional integration, a quantitative technique that integrates the volume beneath an EEM, was developed to analyze EEMs. EEMs were delineated into five excitation-emission regions based on fluorescence of model compounds, DOM fractions, and marine waters or freshwaters. Volumetric integration under the EEM within each region, normalized to the projected excitation-emission area within that region and dissolved organic carbon concentration, resulted in a normalized region-specific EEM volume (phi(i,n)). Solid-state carbon nuclear magnetic resonance (13C NMR), Fourier transform infrared (FTIR) analysis, ultraviolet-visible absorption spectra, and EEMs were obtained for standard Suwannee River fulvic acid and 15 hydrophobic or hydrophilic acid, neutral, and base DOM fractions plus nonfractionated DOM from wastewater effluents and rivers in the southwestern United States. DOM fractions fluoresced in one or more EEM regions. The highest cumulative EEM volume (phi(T,n) = sigma phi(i,n)) was observed for hydrophobic neutral DOM fractions, followed by lower phi(T,n) values for hydrophobic acid, base, and hydrophilic acid DOM fractions, respectively. An extracted wastewater biomass DOM sample contained aromatic protein- and humic-like material and was characteristic of bacterial-soluble microbial products. Aromatic carbon and the presence of specific aromatic compounds (as indicated by solid-state 13C NMR and FTIR data) resulted in EEMs that aided in differentiating wastewater effluent DOM from drinking water DOM.

Biomass↗
PubMed2003

WormBase: a cross-species database for comparative genomics.

WormBase (http://www.wormbase.org/) is a web-accessible central data repository for information about Caenorhabditis elegans and related nematodes. The past two years have seen a significant expansion in the biological scope of WormBase, including the integration of large-scale, genome-wide data sets, the inclusion of genome sequence and gene predictions from related species and active literature curation. This expansion of data has also driven the development and refinement of user interfaces and operability, including a new Genome Browser, new searches and facilities for data access and the inclusion of extensive documentation. These advances have expanded WormBase beyond the obvious target audience of C. elegans researchers, to include researchers wishing to explore problems in functional and comparative genomics within the context of a powerful genetic system.

Animals↗
PubMed2003

The effect of zinc on the apoptosis of cultured human retinal pigment epithelial cells.

To clarify the effects of zinc on the proliferation and apoptosis of cultured human retinal pigment epithelia (RPE) and the expression of caspase-3 in RPE cells. The effect of Zinc on the proliferation of RPE were examined with MTT method. TUNEL method was used to detect the apoptosis of RPE cells. Caspase-3 was detected by immunohistochemistry. A concentration of zinc higher than 0.001 microM could inhibit the proliferation of RPE. And the relationship between concentration of zinc higher than 10 microM and growth prohibition rate of RPE cells was dose-dependent. All concentrations of zinc including 0.001 microM enhanced the expression of caspase-3 of RPE. But only the concentration of zinc higher than 0.01 microM could induce apoptosis of RPE. It is concluded that zinc could enhance the expression of caspase-3 of RPE cells and induce apoptosis of RPE cells. Caution should be taken when using zinc supplements for the treatment of ARMD patients without deficiency of zinc.

Apoptosis↗