Biomedical subjects

Xin Li

Publications and source records attributed to Xin Li.

At least 271 records · Page 15Linked to original sources

PubMed2003

[Mechanism of inhibition of tumor angiogenesis by Bletilla colloid: an experimental study].

OBJECTIVE: To study the mechanism of inhibition of tumor angiogenesis by Bletilla colloid. METHODS: Human Hep-G2 hepatocellular carcinoma cells were cultured and treated with Bletilla colloid of different concentrations. Pure culture of Hep-G2 cells was used as control and pure culture medium without Hep-G2 cell was used as blank control. The concentration of vascular endothelial growth factor (VEGF) in the supernatant was detected by ELISA. The apoptosis and proliferation of the Hep-G2 cells were examined by flow cytometry. Cells of human endothelial cell line ECV-304 were cultured in the supernatant of culture media of Hep-G2 treated with Bletilla colloid of different concentrations. MTT method was used to observe the growth of the ECV-304 endothelial cells. Eighty rats were made animal model of transplanted Walker-256 hepatoma and then randomly divided into 4 groups of 20 rats 12 - 14 days after to undergo transarterial chemoembolization (TACE) treated with normal saline, 5-fluouracil (5-Fu), iodized poppy seed oil, and 5-Fu-Blettila microsphere respectively. Two weeks after, the rats were killed and the tumors were taken out. Immunohistological staining was conducted to detect the expression and localization of factor VIII, VEGF, and basic fibroblast growth factor (b-FGF). The microvcascular density (MVD) was calculated by counting the factor VIII positive endothelial cells. RESULTS: There was no statistically significant difference in the apoptosis rate, proliferation rate and supernatant VEGF level between the control group and the Bletilla groups. The inhibition rates of ECV-304 endothelial cell growth were 57.6%, 66.7%, 86.4%, 87.5%, and 94.8% in the groups of Bletilla of the concentrations of 0.5, 1.0, 2.0, 4.0, and 8.0 micro g/ml respectively in a dose-dependent manner. The MVD of tumor was 59 +/- 34 per field in the 5-Fu-Blatilla group,significantly lower than those in the other 3 groups (F = 5.177, P = 0.003). The expression of VEGF and the expression of b-FGF were not significantly different among the 4 TACE groups. CONCLUSION: Bletilla colloid inhibits angiogenesis after TACE, potentially, through inhibition of the binding of vascular endothelial growth factor to its receptor.

Angiogenesis Inhibitors↗

PubMed2003

Unilamellar liposomes covalently coupled on silica gel for liquid chromatography.

Silica gel was used as a support for the covalent coupling of liposomes, which could overcome drawbacks of soft gel beads in column efficiency and separation speed. The influences of the concentration of added dimethylaminopyridine and reaction time on the chloroformate activation reaction of silica gel were investigated. Temperature and pH for covalent coupling of liposomes on the activated silica gel were also optimized. Experimental results indicated that the stability of the covalently coupled liposome columns was obviously superior to that of the noncovalently coated liposome columns but the selectivity of both columns was basically identical. Separation and analysis of a crude extract of a traditional Chinese medicine Ligusticum Wallichii and a mixture of small peptides on both columns further support this conclusion.

Chromatography, High Pressure Liquid↗

PubMed2003

Significance of c-Myc and Bcl-2 protein expression in nasopharyngeal carcinoma.

OBJECTIVE: To investigate the relationship between oncogene protein expression and nasopharyngeal carcinoma outcome. DESIGN: Tumor samples from 51 patients with nasopharyngeal carcinoma were analyzed by immunohistochemical staining for expression of Bcl-2 and c-Myc protein before irradiation. Five-year follow-up data were available. RESULTS: Thirty-one (61%) of 51 tumors expressed Bcl-2 protein, and 29 (57%) of 51 tumors expressed c-Myc protein. In the Bcl-2+ group, 20 (65%) and 19 (61%) of 31 patients experienced recurrence or died, respectively, whereas only 7 (35%) and 5 (25%) of 20 patients with Bcl-2- tumors did so. On the other hand, patients with c-Myc+ tumors had lower recurrence and death rates (38% [11/29] and 34% [10/29], respectively) than those with c-Myc- tumors (73% [16/22] and 64% [14/22], respectively). A statistically significant association was confirmed between Bcl-2 and c-Myc positivity and patient outcome. CONCLUSION: Expression of Bcl-2 and c-Myc protein seems to be a useful marker to reflect irradiation response and to predict illness condition and patient outcome.

Biomarkers, Tumor↗

PubMed2003

Correlation between prostate cancer grade and vascularity on color doppler imaging: preliminary findings.

PURPOSE: We examined the relationship between the amount of prostate cancer-associated vascularity as seen on color Doppler imaging and the tumor grade. METHODS: Transrectal color Doppler imaging of the prostate was performed in 54 patients with prostate cancer. Color flow signal/total pixel ratios (SPRs) of selected images were calculated using the ratio of the number of pixels showing color Doppler signals to the total number of pixels within the lesion. All the patients underwent prostate biopsy guided by transrectal sonography. Gleason scores were determined from the biopsy specimens. RESULTS: Color Doppler signals were demonstrated in the lesions of 91% (49/54) of the patients. The mean SPRs of prostate cancers 3 cm or smaller and larger than 3 cm were 0.15 +/- 0.07 and 0.11 +/- 0.04 (+/- standard deviation), respectively (p < 0.05). The mean SPRs of well- (Gleason score of 2-4), moderately (Gleason 5-7), and poorly (Gleason 8-10) differentiated prostate cancers were 0.08 +/- 0.03, 0.12 +/- 0.06, and 0.17 +/- 0.11, respectively (r = 0.45; p < 0.01). CONCLUSIONS: The refinement of color Doppler equipment has improved the detection of color Doppler signals associated with prostate cancer. Our study shows a correlation between prostate cancer-associated vascularity as shown on color Doppler imaging and the tumor grade.

Biopsy↗

PubMed2003

Variation of the relaxographic "shutter-speed" for transcytolemmal water exchange affects the CR bolus-tracking curve shape.

Contrast reagents (CRs) may enter the tissue interstitium for a period after a vascular bolus injection. As the amount of interstitial CR increases, the longitudinal relaxographic NMR "shutter-speed" (T(-1)) for the equilibrium transcytolemmal water exchange process increases. The quantity T(-1) is given by |r(1o)[CR(o)] + R(1o0) - R(1i)| (where r(1o) and [CR(o)] represent the interstitial (extracellular) CR relaxivity and concentration, respectively, and R(1o0) and R(1i) are the extra- and intracellular (1)H(2)O relaxation rate constants, respectively, in the absence of exchange). The increase of T(-1) with [CR(o)] causes the kinetics of the water exchange equilibrium to appear to decrease. Here, analytical theory for two-site-exchange processes is combined with that for pharmacokinetic CR delivery, extraction, and distribution in a method termed BOLus Enhanced Relaxation Overview (BOLERO(Copyright )). The shutter-speed effect alters the shape of the bolus-tracking (B-T) time-course. It is shown that this is mostly accounted for by the inclusion of only one additional parameter, which measures the mean intracellular lifetime of a water molecule. Simulated and real data demonstrate that the effect of shutter-speed variation on pharmacokinetic parameters can be very significant: neglecting this effect can lead to an underestimation of the parameter values by 50%. This phenomenon can be heterogeneous. Within a tiny gliosarcoma implanted in the rat brain, the interstitial CR in the tumor core never rises to a level sufficient to cause apparent slowing of the exchange process. However, within the few microns needed to reach the proliferating rim, this occurs to a significant degree. Thus, even relative pharmacokinetic quantities can be incorrectly represented in a parametric map that neglects this effect. The BOLERO analysis shows promise for in vivo vascular phenotyping in pathophysiology. It also includes a provision for approximating the separation of the perfusion and permeability contributions to CR extravasation.

Animals↗

PubMed2003

The clinical pathology of severe acute respiratory syndrome (SARS): a report from China.

In order to investigate the clinical pathology of severe acute respiratory syndrome (SARS), the autopsies of three patients who died from SARS in Nan Fang Hospital Guangdong, China were studied retrospectively. Routine haematoxylin and eosin (H&E) staining was used to study all of the tissues from the three cases. The lung tissue specimens were studied further with Macchiavello staining, viral inclusion body staining, reticulin staining, PAS staining, immunohistochemistry, ultrathin sectioning and staining, light microscopy, and transmission electron microscopy. The first symptom was hyperpyrexia in all three cases, followed by progressive dyspnoea and lung field shadowing. The pulmonary lesions included bilateral extensive consolidation, localized haemorrhage and necrosis, desquamative pulmonary alveolitis and bronchitis, proliferation and desquamation of alveolar epithelial cells, exudation of protein and monocytes, lymphocytes and plasma cells in alveoli, hyaline membrane formation, and viral inclusion bodies in alveolar epithelial cells. There was also massive necrosis of splenic lymphoid tissue and localized necrosis in lymph nodes. Systemic vasculitis included oedema, localized fibrinoid necrosis, and infiltration of monocytes, lymphocytes, and plasma cells into vessel walls in the heart, lung, liver, kidney, adrenal gland, and the stroma of striated muscles. Thrombosis was present in small veins. Systemic toxic changes included degeneration and necrosis of the parenchyma cells in the lung, liver, kidney, heart, and adrenal gland. Electron microscopy demonstrated clusters of viral particles, consistent with coronavirus, in lung tissue. SARS is a systemic disease that injures many organs. The lungs, immune organs, and systemic small vessels are the main targets of virus attack, so that extensive consolidation of the lung, diffuse alveolar damage with hyaline membrane formation, respiratory distress, and decreased immune function are the main causes of death.

Adrenal Glands↗

PubMed2003

Purification and characterization of an extracellular alkaline serine protease with dehairing function from Bacillus pumilus.

An extracellular alkaline serine protease (called DHAP), produced by a Bacillus pumilus strain, demonstrates significant dehairing function. This protease is purified by hydrophobic interaction chromatography, ion exchange, and gel filtration. DHAP had a pI of 9.0 and a molecular weight of approximately 32,000 Dalton. It shows maximal activity at pH 10 and with a temperature of 55 degrees C; the enzyme activity can be completely inhibited by phenylmethylsulfonyl fluoride (PMSF) and diisopropyl fluorophosphates (DFP). The first 20 amino acid residues of the purified DHAP have been determined with a sequence of AQTVPYGIPQIKAPAVHAQG. Alignment of this sequence with other alkaline protease demonstrates its high homology with protease from another B. pumilus strain.

Amino Acid Sequence↗

PubMed2003

SNAREs and epithelial cells.

SNARE proteins control the membrane fusion events of membrane trafficking pathways. Work in epithelial cells has shown that polarized trafficking to the apical and basolateral plasma membrane domains requires different sets of SNAREs, suggesting a mechanism that contributes to the overall specificity of polarized trafficking and, perhaps, the formation and maintenance of polarity itself. This article describes methods that have been designed and adapted specifically for the investigation of SNAREs in epithelial cells. The knowledge of the subcellular localization of a SNARE of interest is essential to understand its function. Unfortunately, the endogenous expression levels of SNAREs are often low which makes detection challenging. We provide guidelines for determination of the localization of SNAREs by immunofluorescence microscopy including methods for signal amplification, antigen retrieval, and suppression of antibody cross-reactivity. To define which trafficking pathway a SNARE of interest is involved in, one needs to specifically inhibit its function. We provide guidelines for SNARE inhibition by overexpression of the SNARE of interest. An alternative is to introduce inhibitors of SNARE function, such as antibodies or clostridial toxins, into cells. Two methods are presented to make this possible. The first allows the monitoring of effects on trafficking pathways by biochemical assays, and is based on plasma membrane permeabilization using the bacterial toxin streptolysin-O. The second is suitable for single-cell observations and is based on microinjection.

Epithelial Cells↗

PubMed2003

Syntaxin 2 and endobrevin are required for the terminal step of cytokinesis in mammalian cells.

The terminal step of cytokinesis in animal cells is the abscission of the midbody, a cytoplasmic bridge that connects the two prospective daughter cells. Here we show that two members of the SNARE membrane fusion machinery, syntaxin 2 and endobrevin/VAMP-8, specifically localize to the midbody during cytokinesis in mammalian cells. Inhibition of their function by overexpression of nonmembrane-anchored mutants causes failure of cytokinesis leading to the formation of binucleated cells. Time-lapse microscopy shows that only midbody abscission but not further upstream events, such as furrowing, are affected. These results indicate that successful completion of cytokinesis requires a SNARE-mediated membrane fusion event and that this requirement is distinct from exocytic events that may be involved in prior ingression of the plasma membrane.

Animals↗

PubMed2003

Three-dimensional analysis of post-Golgi carrier exocytosis in epithelial cells.

Targeted delivery of proteins to distinct plasma membrane domains is critical to the development and maintenance of polarity in epithelial cells. We used confocal and time-lapse total internal reflection fluorescence microscopy (TIR-FM) to study changes in localization and exocytic sites of post-Golgi transport intermediates (PGTIs) carrying GFP-tagged apical or basolateral membrane proteins during epithelial polarization. In non-polarized Madin Darby Canine Kidney (MDCK) cells, apical and basolateral PGTIs were present throughout the cytoplasm and were observed to fuse with the basal domain of the plasma membrane. During polarization, apical and basolateral PGTIs were restricted to different regions of the cytoplasm and their fusion with the basal membrane was completely abrogated. Quantitative analysis suggested that basolateral, but not apical, PGTIs fused with the lateral membrane in polarized cells, correlating with the restricted localization of Syntaxins 4 and 3 to lateral and apical membrane domains, respectively. Microtubule disruption induced Syntaxin 3 depolarization and fusion of apical PGTIs with the basal membrane, but affected neither the lateral localization of Syntaxin 4 or Sec6, nor promoted fusion of basolateral PGTIs with the basal membrane.

Animals↗

PubMed2003

Recombinant tissue plasminogen activator (alteplase) for restoration of function to occluded central venous catheters in pediatric patients.

PURPOSE: To evaluate the safety and efficacy of alteplase for restoring function to occluded central venous catheters in a pediatric population. PATIENTS AND METHODS: A phase III, open-label, single-arm, multicenter trial was performed in 995 adult and pediatric patients with dysfunctional nondialysis catheters and ports. This report is a subset analysis of subjects between 2 and 18 years of age (N = 122) who were enrolled in the study. Alteplase (2 mg/2 mL) was instilled into the dysfunctional catheter lumen and assessed at 30 and 120 minutes. Subjects weighing > or =30 kg received 2 mL of alteplase; subjects <30 kg received 110% of the internal lumen volume (not exceeding 2 mL). Alteplase dosing was repeated once after 120 minutes if the catheter remained dysfunctional. The primary safety endpoint was the rate of intracranial hemorrhage (ICH) within 5 days of treatment. RESULTS: The overall efficacy following up to two instilled doses of alteplase was 87%. In 70 patients (57%), restoration of catheter flow occurred by 30 minutes following a single dose of alteplase. Restoration of function was related to the duration of occlusion (P = 0.04). For catheters with occlusions of 0, 1 to 14, and >14 days duration, the efficacy was 91%, 78%, and 60%, respectively. Success was independent of the patient's age, sex, body weight, CVC type, or catheter age. There were no cases of death, ICH, major bleeding episodes, or embolic events attributable to treatment. CONCLUSIONS: An alteplase regimen of up to two 2-mg doses is safe and effective for restoration of function to occluded central venous catheters in a pediatric population.

Adolescent↗

PubMed2003

Evaluation of the effect of protamine on human prostate carcinoma PC-3m using contrast enhanced Doppler ultrasound.

PURPOSE: We evaluated the ability of contrast enhanced Doppler ultrasound (CEDU) to demonstrate changes in tumor vascularity during angiogenesis inhibitive therapy in PC-3m human prostate carcinoma. MATERIALS AND METHODS: Pieces of human prostate carcinoma PC-3m tumor (Institute of Urology, Beijing University, Beijing, People's Republic of China) were transplanted subcutaneously into 48 male BALB/C nude mice (Center of Animal Quarantine, Beijing, People's Republic of China). Protamine (Shanghai Biochemistry Pharmaceutical Co., People's Republic of China) was injected subcutaneously as an angiogenesis inhibitor. The animals were randomly divided into 3 groups according to protamine dose. The color flow signal-pixel rate (SPR) of the images was calculated using the number of pixels showing color Doppler signals as a ratio of the total number of pixels covering the lesion. RESULTS: The SPR of the high and low dose groups were significantly lower than that of the control group (p <0.01). Mean SPR +/- SD in the 3 groups was 0.09 +/- 0.05, 0.11 +/- 0.05 and 0.22 +/- 0.10, respectively. SPR correlated significantly with microvessel density (r = 0.86 to 0.94, p <0.01). CONCLUSIONS: CEDU can effectively reveal the change in vascularity in a tumor that was treated with protamine. In addition to microvessel density, CEDU may become one of several independent prognostic indexes of angiogenesis inhibitor therapy.

Angiogenesis Inhibitors↗

PubMed2003

Isolation and characterization of phyC mutants in Arabidopsis reveals complex crosstalk between phytochrome signaling pathways.

Studies with mutants in four members of the five-membered Arabidopsis phytochrome (phy) family (phyA, phyB, phyD, and phyE) have revealed differential photosensory and/or physiological functions among them, but identification of a phyC mutant has proven elusive. We now report the isolation of multiple phyC mutant alleles using reverse-genetics strategies. Molecular analysis shows that these mutants have undetectable levels of phyC protein, suggesting that they are null for the photoreceptor. phyC mutant seedlings were indistinguishable from wild-type seedlings under constant far-red light (FRc), and phyC deficiency had no effect in the phyA mutant background under FRc, suggesting that phyC does not participate in the control of seedling deetiolation under FRc. However, when grown under constant red light (Rc), phyC seedlings exhibited a partial loss of sensitivity, observable as longer hypocotyls and smaller cotyledons than those seen in the wild type. Although less severe, this phenotype resembles the effect of phyB mutations on photoresponsiveness, indicating that both photoreceptors function in regulating seedling deetiolation in response to Rc. On the other hand, phyB phyC double mutants did not show any apparent decrease in sensitivity to Rc compared with phyB seedlings, indicating that the phyC mutation in the phyB-deficient background does not have an additive effect. These results suggest that phyB is necessary for phyC function. This functional dependence correlates with constitutively lower levels of phyC observed in the phyB mutant compared with the wild type, a decrease that seems to be regulated post-transcriptionally. phyC mutants flowered early when grown in short-day photoperiods, indicating that phyC plays a role in the perception of daylength. phyB phyC double mutant plants flowered similarly to phyB plants, indicating that in the phyB background, phyC deficiency does not further accelerate flowering. Under long-day photoperiods, phyA phyC double mutant plants flowered later than phyA plants, suggesting that phyC is able to promote flowering in the absence of phyA. Together, these results suggest that phyC is involved in photomorphogenesis throughout the life cycle of the plant, with a photosensory specificity similar to that of phyB/D/E and with a complex pattern of differential crosstalk with phyA and phyB in the photoregulation of multiple developmental processes.

Arabidopsis↗

PubMed2003

Mutations in Aspergillus fumigatus resulting in reduced susceptibility to posaconazole appear to be restricted to a single amino acid in the cytochrome P450 14alpha-demethylase.

To better understand the molecular basis of posaconazole (POS) resistance in Aspergillus fumigatus, resistant laboratory isolates were selected. Spontaneous mutants arose at a frequency of 1 in 10(8) and fell into two susceptibility groups, moderately resistant and highly resistant. Azole resistance in A. fumigatus was previously associated with decreased drug accumulation. We therefore analyzed the mutants for changes in levels of transcripts of genes encoding efflux pumps (mdr1 and mdr2) and/or alterations in accumulation of [(14)C]POS. No changes in either pump expression or drug accumulation were detected. Similarly, there was no change in expression of cyp51A or cyp51B, which encode the presumed target site for POS, cytochrome P450 14alpha-demethylase. DNA sequencing revealed that each resistant isolate carried a single point mutation in residue 54 of cyp51A. Mutations at the same locus were identified in three clinical A. fumigatus isolates exhibiting reduced POS susceptibility but not in susceptible clinical strains. To verify that these mutations were responsible for the resistance phenotype, we introduced them into the chromosome of a POS-susceptible A. fumigatus strain under the control of the glyceraldehyde phosphate dehydrogenase promoter. The transformants exhibited reductions in susceptibility to POS comparable to those exhibited by the original mutants, confirming that point mutations in the cyp51A gene in A. fumigatus can confer reduced susceptibility to POS.

Antifungal Agents↗

PubMed2003

Influence of transarterial chemoembolization on angiogenesis and expression of vascular endothelial growth factor and basic fibroblast growth factor in rat with Walker-256 transplanted hepatoma: an experimental study.

AIM: After transarterial chemoembolization (TACE), the residual cancer cells are under extensive hypoxic or even anoxic environment. Hypoxia can lead to adaptive responses. For example, angiogenesis will help these cells survive. In this study, we examined the effect of TACE on angiogenesis and expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) and to assess their relevance to Walker-256 transplanted hepatoma. METHODS: Male Wistar rats were inoculated with Walker-256 tumor in the left lobe of liver. Angiography and transarterial chemoembolization were performed at d14 after transplantation. Sixty rats bearing walker-256 transplanted hepatoma were randomly divided into control group, arterial infusion group and TACE group. Each group consisted of twenty rats. Normal saline, 5-Fu, 5-Fu and lipiodol were infused through hepatic artery respectively. Two weeks after the infusion, staining of factor VIII, VEGF and b-FGF was performed by immunohistochemistry method in routine paraffin-embedded sections. Microvessel density (MVD) was counted in endothelial cells with positive factor VIII. Their expression levels were analyzed in conjunction with the pathologic features. RESULTS: While a smaller tumor volume was found in TACE group (F=37.818, P<0.001), no statistical differences between MVD and expression of VEGF and b-FGF were found among the 3 groups. MVD of the control group, chemotherapy group and chemoemoblization group was 80.84+/-24.24, 83.05+/-20.29 and 85.20+/-23.91 (F=0.193, P=0.873), respectively. The positive expression of VEGF and b-FGF was 75%, 75%, 85% (chi2=0.449, P=0.799) and 30%, 25%, 30% (chi2=0.141, P=0.922), respectively. Statistical analysis revealed a positive correlation between the expression of VEGF and MVD (r=0.552, P<0.001). CONCLUSION: There has been little influence of lipiodol chemoembolization on the formation of tumor angiogenesis, but the development of neovascularization and expression of VEGF play important roles in establishment of collateral circulation and reconstruction of blood supply of residual cancer tissue.

Animals↗

PubMed2003

Investigation of Epstein-Barr virus in Chinese colorectal tumors.

AIM: To elucidate the association of Epstein-Barr virus (EBV) with colorectal tumors and to demonstrate whether infection of EBV existed in different stages of colorectal tumors involves in the carcinogenesis. METHODS: One hundred and thirty paraffin-embedded tissues of colorectal tumors were classified into 5 groups: 26 adenomas, 23 adenomas complicated with dysplasia, 22 adenomas complicated with carcinomatous, 36 colon carcinoma and 23 HNPCC, were examined by PCR, IHC and ISH, respectively. RESULTS: EBV DNA was detected by PCR in 26 cases out of the 130 specimens, including 5 cases of adenomas, 5 adenomas complicated with dysplasia, 5 adenomas complicated with carcinomatous, 7 colorectal carcinoma and 4 HNPCC. IHC detection showed the expression of LMP1 in 7 cases, including 1 adenoma, 1 adenoma with dysplasia, 1 HNPPC, 2 adenomas complicated with carcinomatous, and 2 colorectal carcinomas. The expression of EBER1 detected by ISH was positive in 6 cases, including 1 adenoma with dysplasia, 2 adenomas complicated with carcinomatous and 3 colorectal carcinomas. There were no significant differences among the results of PCR, IHC and ISH in the 5 groups. In all cases of HNPCC, none of the tumor cells showed positive signals of EBER1, but some EBV-positive tumor infiltrating lymphocytes were found in 2 of 23 cases. CONCLUSION: Our results showed that infection of EBV exists in human colorectal tumors, which indicates that EBV may be involved in the carcinogenesis of colorectal tumors but does not play an important role. The mechanisms need to be clarified further.

Adenoma↗

PubMed2003

Overexpression of ETS2 in human esophageal squamous cell carcinoma.

AIM: To study the expression pattern of ETS2 (erythroblastosis virus oncogene homolog 2) in human esophageal squamous cell carcinoma (ESCC). METHODS: Reverse transcription polymerase chain reaction (RT-PCR) and Northern blot were performed to examine the expression level of ETS2 mRNA in 37 pairs of ESCC tissue samples. Western blot and immunohistochemistry were carried out to check the expression level of ETS2 protein in 30 pairs of ESCC tissue specimens. RESULTS: RT-PCR and Northern blot analysis showed that ETS2 mRNA upregulated in 75.7 % (28/37) examined ESCC tissues relative to matched normal tissues. From those 37 cases, 14 cases were randomly selected to perform Western blot and the results revealed that ETS2 protein overexpressed in 71.4 % (10/14) checked ESCC tissues compared with the corresponding normal tissues. Moreover, the expression patterns of ETS2 protein in those 14 cases were identical to those of ETS2 mRNA displayed by RT-PCR or Northern Blot. Immunohistochemistry analysis showed that the expression level of ETS2 protein rose in 75 % (12/16) tumor epithelial cells contrasted to the normal cells. Altogether the expression level of ETS2 protein increased in 73.3 % (22/30) checked ESCC tissue samples contrary to their normal counterparts. CONCLUSION: The results suggested that ETS2 overexpressed in paired human ESCC tissue samples at both mRNA and protein levels and may be associated with the tumorigenesis of esophagus.

Blotting, Northern↗

PubMed2003

Modeling of residual chlorine in water distribution system.

Water quality within water distribution system may vary with both location and time. Water quality models are used to predict the spatial and temporal variation of water quality throughout water system. A model of residual chlorine decay in water pipe has been developed, given the consumption of chlorine in reactions with chemicals in bulk water, bio-films on pipe wall, in corrosion process, and the mass transport of chlorine from bulk water to pipe wall. Analytical methods of the flow path from water sources to the observed point and the water age of every observed node were proposed. Model is used to predict the decay of residual chlorine in an actual distribution system. Good agreement between calculated and measured values was obtained.

Chlorine↗