Biomedical subjects
Publications and source records attributed to W You.
Explore the source record for details and available documents.
OBJECTIVE: To identify human gastric cancer related genes. METHODS: Specimens of paired tumor, paratumor and normal gastric mucosa tissues were collected from five patients (male 3, female 2, with average age 48.8 +/- 18.1 years) who suffered from stomach antrum adenocarcinoma. Total RNA samples were extracted from these specimens, then studied by fluorescent differential display reverse transcription polymerase chain reaction (DDRT- PCR) analysis. The differentially expressed bands of interest were recovered, purified and cloned, then they were analyzed by sequencing, Northern blot and RT-PCR. Through BLAST, the sequencing results were compared with GenBank database for homology analysis. RESULTS: One of the interesting cDNA bands expressed much lower in all five tested tumor samples than in their normal and paratumor counterparts. This band was named W4. Northern blot analysis showed a consistent result with that of DDRT-PCR. W4 was cloned into pGEM-T easy vector. Sequence analysis showed that W4 consists of 712bp, this sequence was named W44. BLAST analysis revealed that W44 has extremely low sequence identity with any genes from GenBank and any sequences from EST database. This sequence data was submitted to GenBank with accession No. AF150631. RT-PCR analysis showed that W4 was expressed much lower in 11/15 gastric cancer tissue than in paratumor and normal samples. CONCLUSION: A novel cDNA sequence related to human stomach adenocarcinoma was identified.
OBJECTIVE: To investigate a method for safe, simple and effective correction of nasal deviation complicated with the deformity of nasal septal cartilage. METHODS: From one side of the septal cartilage, the whole muco-perichondrium was separated, and from the other side a U-shaped muco-perichondrium was separated. The bottom of the septal cartilage was freed while a part of cartilage connected with the vomer was reserved. RESULTS: 12 patients were operated on with this technique for nasal deviation from March 1996 to August 1999. The follow-up period ranged from 1 to 12 months. The overall result was successful in all cases except one of recurrence. CONCLUSION: This technique not only provides wide space for removing the spetal cartilage, but also creates a cartilaginous framework to support the septal cartilage in the middle without lowing the nasal tip, which avoids the tendency of migrating to its original position caused by external fixation. This technique also ensures replacing the septal cartilage in the midline regardless of the deformity of anterior nasal spine and the vomer.
PURPOSE: In urban Shanghai, the largest industrial and commercial city in China, the age-adjusted (world standard) incidence rates for colorectal cancer increased from 14.5 to 23.3 per 10(5) men and from 12.1 to 20.3 per 10(5) women between 1972 and 1996. This change was even more pronounced for colon cancer, whose incidence rates doubled from 5.95 to 13.7 per 10(5) men and from 5.77 to 12.5 per 10(5) women. The reasons for the rapid increases in cancer rates are not fully understood, but may involve dietary exposures that have changed substantially over the past two decades.METHODS: We calculated Pearson correlation coefficients (r) between colorectal cancer rates and the dietary factors of grain, vegetable oil, pork, poultry and vegetable consumption over the period of 1972 through 1996 in urban Shanghai.RESULTS: Statistically significant positive associations were observed between colon cancer rates and per capita consumption of vegetable oil (r = 0.91 for men, r = 0.94 for women), poultry (r = 0.90 for men, r = 0.90 for women), and pork (r = 0.78 for men, r = 0.81 for women). The correlation coefficients were not statistically significant between colon cancer and per capita consumption of grain (r = 0.38 for men, r = 0.37 for women) or vegetables (r = 0.16 for men, r = 0.14 for women). Similar weaker associations were observed between rectal cancer rates and vegetable oil, pork and poultry consumption.CONCLUSIONS: The findings in our study suggest that increases in dietary fat, poultry and pork intake may play a role in the rising colorectal cancer rates in Shanghai.
Androgen receptor (AR) plays an important role in growth and hormonal therapy of human prostate tumors. Immunohistochemical analysis of AR expression, a nonquantitative technique, is currently used for screening of receptor expression in prostate tissues. The present report describes a laser flow cytometric method for monitoring AR expression in human cell lines and in archival formalin-fixed paraffin-embedded prostate tissues and tumors. Multiparametric flow analysis can be used for simultaneous detection of other cellular markers (e.g., DNA aneuploidy), and by gated analysis, AR expression in subpopulations of a tumor can be quantitatively determined.
Polycyclic aromatic hydrocarbons (PAHs) emitted from 25 industrial boilers were investigated. The fuels used for these 25 boilers included 21 heavy oil, two diesel, a co-combustion of heavy oil and natural gas (HO+NG) and a co-combustion of coke oven gas and blast furnace gas (COG+BFG) boilers. PAH samples from the stack flue gas (gas and particle phases) of these 25 boilers were collected by using a PAH stack sampling system. Twenty one individual PAHs were analyzed primarily by a gas chromatography/mass spectrometer (GC/MS). Total-PAH concentration in the flue gas of 83 measured data for these 25 boiler stacks ranged between 29.0 and 4250 microg/m(3) and averaged 488 microg/m(3). The average of PAH-homologue mass (F%) counted for the total-PAH mass was 54.7%, 9.47% and 15.3% for the 2-ring, 3-ring and 4-ring PAHs, respectively. The PAHs in the stack flue gas were dominant in the lower molecular weight PAHs. The emission factors (EFs) of total-PAHs were 13,300, 2920, 2880 and 208 microg/kg-fuel for the heavy oil, diesel, HO+NG and COG+BFG fueled-boiler, respectively. Nap was the most predominant PAH occurring in the stack flue gas. In addition, the EF of 21 individual PAHs in heavy-oil boiler were almost the highest among the four various fueled-boilers except for those of FL and BkF in the diesel boiler. Furthermore, the EF of total-PAHs or BaP for heavy oil were both one order of magnitude higher than that for the diesel-fueled boiler.
Curcumin has anti-inflammatory, antiproliferative, and antitumor effects. To understand the chemopreventive mechanism of curcumin against human malignancies, the cellular and molecular changes induced by this agent in human mammary epithelial (MCF-10A) and breast carcinoma (MCF- 7/TH) cell lines were investigated. The human multidrug- resistant breast cancer cell line was 3.5 fold more sensitive to curcumin than the mammary epithelial cell line. Even though both cell lines accumulated a similar amount of curcumin, a significantly higher percentage of apoptotic cells was induced in breast cancer cells compared to a very low percentage of apoptosis in mammary epithelial cells. Incubation of breast cancer cells with 20 and 40 microM curcumin for 24 h induced G2 block and sub-G0/G1 cell population, respectively. Curcumin treatment caused a reduction in the expression of Ki67, PCNA, and p53 mRNAs in breast cancer cells. The human mammary epithelial cell line showed a down-regulation of p21 mRNA and an up-regulation of Bax mRNA expression with curcumin treatment. The results suggest that apoptosis is involved in the curcumin-induced inhibition of tumor cell growth, and genes associated with cell proliferation and apoptosis may be playing a role in the chemopreventive action of curcumin.
The discordance between P-glycoprotein (P-gp) expression and functionality [as measured by the efflux of doxorubicin (DOX)] was analyzed in a DOX-sensitive human breast cancer cell line (HTB-123) with high reactivity against four P-gp specific monoclonal antibodies (C219, MRK-16, UIC2, and 4E3). Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting analyses confirmed the overexpression of MDR1 mRNA and P-gp in this cell line. However, incubation of cells with efflux blockers, verapamil (VPL) or dipyridamole (DPD), did not enhance cellular (DOX) accumulation or cytotoxicity. Upon incubation with 12-O-tetradecanoylphorbol-13-acetate (TPA), HTB-123 cells retained less DOX than control cells and were sensitive to the efflux blockers verapamil or dipyridamole. These observations suggest that 12-O-tetradecanoylphorbol-13-acetate-induced P-gp phosphorylation may be associated with induction of P-gp-mediated drug efflux in the HTB-123 cell line.
Ursolic acid was isolated form Herba Cynomorii by thin layer chromatography and was quantitatively determined by ultraviolet spectrophotometry. The results indicate that the content of ursolic acid is 0.78%. The average recovery rate of ursolic acid is 97.4%, RSD = 0.45% (n = 4).
We characterized glomerular function in adults with sickle cell anemia (SSA): 12 with normal renal function (SSA-controls), and 15 with renal insufficiency (SSA-CRF). GFR was similar in SSA-controls and healthy-controls, however, renal plasma flow was increased in SSA-controls. In SSA-CRF, the albumin and IgG excretion rates were enhanced. The fractional clearances of all dextran sizes (26 to 64 A) were significantly increased in both SSA-controls and SSA-CRF versus healthy-controls. In SSA-CRF, the fractional clearance of dextrans > 58 A was enhanced. Analysis with an "isoporous+shunt" model revealed an increase in the mean restrictive pore radius (ro) by 5 A in SSA-controls and SSA-CRF, versus healthy-controls. In SSA-CRF, the total number of membrane pores was reduced > 70%, and the shunt parameter increased twofold. We conclude that SSA patients have a distinct pattern of glomerular dysfunction with generalized increased permeability to dextrans, resulting from an increase in pore radius. When CRF develops, the total number of membrane pores is reduced, and a size-selectivity defect occurs. The changes in dextran permeability cannot be attributed to purely hemodynamic changes (increased RPF or low filtration fraction), or to known modulators of membrane porosity. These findings suggest that unique mechanism(s) are implicated in the pathogenesis of sickle glomerulopathy.
OBJECTIVE: To assess the changes and possible role of expression of TGF-alpha and EGFR in gastric carcinogenesis and its relationship with PCNA labelling index (PCNA LI). METHODS: Immunohistochemical study using LSAB kit. RESULTS: (1) The expression of TGF-alpha was increased in normal mucosa and metaplastic tissue near the carcinoma when compared with non-cancer controls (P < 0.01). (2) Increased expression of EGFR was found in the intestinal metaplastic and dysplastic areas compared with nomral mucosa and carcinoma tissue (P < 0.01). (3) Coexpression rate of TGF-alpha and EGFR was higher in dysplasia than in other tissues (P < 0.01). (4) There was a close correlation between the intensities of TGF-alpha, EGFR and PCNA. (5) The expression of TGF-alpha, EGFR and PCNA was not related to infiltration and lymph node metastasis of gastric carcinoma. CONCLUSION: The increased expression of EGFR, TGF-alpha may serve as an important molecular marker of gastric premalignant lesions when combined with measurement of PCNA LI and may be of assistance in screening of early gastric carcinoma in high risk populations.
OBJECTIVE: To clarify the relationship between c-myc gene amplification and expression in human hepatocellular carcinoma (HCC) tissue. METHODS: Levels of amplification, transcription and P62 myc expression of c-myc gene in tumor tissues and corresponding non-tumor tissues were systematically studied using Dot blot hybridization, in situ hybridization and immunohistochemical technique, respectively. The 14 pairs of specimens were resected from patients with HCC. RESULTS: The amplification of c-myc gene was not found in tumor and non-tumor tissues. Overexpression of c-myc mRNA transcription was detected in 11 tumor tissues and 10 non-tumor tissues. The positive rate of P62 myc was 85.7% (12/14) in tumor tissues and 92.9% (13/14) in non-tumor tissues, respectively. A close correlation was noticed between c-myc mRNA and P62 myc expression. The results suggested that c-myc gene overexpression was not related to its amplification. CONCLUSIONS: The overexpression of c-myc mRNA and gene product without amplification may be characteristic in HCC.
Immunohistochemistry (ABC method) and in situ hybridization (DNA-RNA) were used to detect c-myc and p53 gene expression in tissues of human HCC and nearby non-tumorous liver (NT) from 23 patients. The results showed that the positive rates of P62c-myc were 87% (20/23) in HCC and 91% (21/23) in NT. The positive rates of P53 protein were 39% (9/23) in HCC as well as in NT. The positive rates of c-myc and p53 mRNA were 70% (16/23) and 56% (13/23) in HCC and NT respectively. The expression of c-myc and p53 at protein level was significantly correlated with that at mRNA level. These observations suggest a close association of c-myc and p53 gene overexpression with hepatocarcinogenesis. Immunohistochemistry (ABC method) on section of paraffin embedded tissue is a reliable method for detecting c-myc and p53 gene expression in HCC.
We developed site-specific fluorescent probes that permit simultaneous microscopic observation of G- and F-actin in bovine endothelial cells. G-actin distribution was visualized with fluorescein-deoxyribonuclease I (DNAse I). F-actin was labeled with phalloidin conjugated to the new long-wavelength fluorophore BODIPY 581/591 (581-nm excitation, 591-nm emission), which is spectrally similar to Texas Red. The G-actin appeared as pervasive green fluorescence that was more intense in the nuclear region, where cell thickness is greater and stress fibers are less frequent. In addition, we observed a punctate fluorescein pattern around the nuclei and in other parts of the cells, suggesting that some G-actin is localized to small discrete sites. F-actin was observed as red fluorescent filaments. Unlabeled DNAse I effectively prevented staining of G-actin by the fluorescent DNAse I conjugates. The specificity of DNAse I for G-actin was confirmed by the presence of a single labeled band with molecular weight corresponding to actin in a Western blot of total cytoplasmic endothelial proteins reacted with biotin-DNAse I-streptavidin-alkaline phosphatase. Anti-actin antibody, which associates with both G- and F-actin, in conjunction with fluorescent secondary antibody produced a pattern similar to that obtained by simultaneous visualization with fluorescein-DNAse I and BODIPY 581/591- or rhodamine-phalloidin.
Inhibition of bovine pancreatic deoxyribonuclease I (DNase I) has been a standard method for specific quantitation of monomeric (G-) actin. The aim of this work is to substantially enhance the sensitivity of this type of G-actin assay by using a fluorescent dye, thiazole orange (TO), which has a high optical absorption, moderate DNA affinity, and large fluorescence enhancement upon binding to DNA. The high fluorescence output and moderate affinity of TO's DNA complex produce a large fluorescence decrease when the complex is disrupted by DNase I, thus permitting a highly sensitive detection of G-actin by its inhibition on the fluorescence decrease. The results show that the dynamic responsiveness of a fluorometric G-actin assay can be improved by lowering the concentration of DNA and affinity of the labeling dye, as long as the fluorescence signal of the dye-DNA complex is sufficient for instrumental detection. With a DNA concentration of 6.0 micrograms/ml and TO dye labeling, as little as 20 ng of G-actin can be reliably detected in a fluorescence microplate scanner. This sensitivity also appears to be the utmost detection limit of any G-actin assay that is based on DNase I inhibition.
We describe here the in situ detection of alkaline phosphatase (APase) activity with a new fluorogenic substrate, 2-(5'-chloro-2'-phosphoryloxyphenyl)-6-chloro-4-(3H)-quinazolinone (CPPCQ). CPPCQ is very soluble and colorless. APase converts it into a rapidly precipitating product, whose strong fluorescence marks the sites of APase activity. The detected APase was either a probing enzyme anchored to epidermal growth factor (EGF) receptors of fixed human epidermoid carcinoma cell line (A431) by biotinylated EGF and streptavidin-APase conjugates or an endogenous marker existing in a fixed canine kidney cell line (MDCK). With CPPCQ staining, the EGF receptors and the endogenous APase were both visualized by fluorescence microscopy as contrasting, photostable, and well-resolved fluorescent stains. The EGF receptor staining was specific since it could be blocked by excessive unlabeled EGF. In contrast, fluorescein-labeled EGF failed to specifically stain the EGF receptors under the same fluorescent microscope. The endogenous APase staining with CPPCQ was sensitive to heating, levamisole and L-homoarginine, showing an APase tissue specificity of the liver/bone/kidney type. Therefore, CPPCQ appears to be a novel substrate dye for sensitive fluorescence APase histochemistry.
Characterization of 2-(2'-phosphoryloxyphenyl)-4(3H)-quinazolinone (PPQ) derivatives as fluorogenic precipitating substrates of phosphatases is reported in this work. Soluble and colorless PPQ derivatives can be specifically hydrolyzed by acid and alkaline phosphatases into insoluble products, 2-(2'-hydroxyphenyl)-4(3H)-quinazolinone (HPQ) derivatives which appear as fluorescent precipitates in water. The fluorescence and precipitation of HPQ depend on the concentration of its neutral phenolic form and therefore are related to the aqueous pH and PPQ concentration converted. Since HPQ formed from corresponding PPQ hydrolysis by phosphatases instantly precipitates and simultaneously fluoresces with a high photostability and large Stokes shift in water, PPQ can serve as a novel class of substrate dyes for detecting any immobilized phosphatase activities in situ, especially for applications of sensitive fluorescence histochemistry and cytochemistry. This is demonstrated by the alkaline phosphatase-aided visualization of static concanavalin A (Con A) receptors. By a linkage-amplification technique involving biotinylated Con A, streptavidin-alkaline phosphatase conjugate, and a PPQ substrate, the Con A receptors on the membrane of fixed NIH 3T3 cell were specifically viewed as dense, contrasting, durable, and cytologically resolved fluorescent stains under a conventional fluorescent microscope.
A competitive ELISA for sensitive detection of 2,4-dinitrophenol (DNP) was established. Certain amounts of bovine serum albumin conjugate of DNP were readily coated on a polystyrene microplate. Free DNP was then quantitated by its competition with the coated DNP for binding to anti-DNP (antibody)-alkaline phosphatase conjugate. The enzyme conjugate remaining on the plate surface as a result of the competition was detected by an enzymatic reaction with a fluorogenic substrate, 3,6-fluorescein diphosphate (FDP), or comparatively with a conventional chromogenic substrate, p-nitrophenyl phosphate (PNPP). The results showed that the ELISA with FDP at the optimal conditions of enzymatic reaction can detect as little as 10 fmol DNP, a detection limit of 50 times less than that with PNPP. The easy and sensitive DNP assay procedures in this work can be generalized to ELISAs for other antigens, particularly small antigens, haptens or drugs.