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Li Zhang

Publications and source records attributed to Li Zhang.

At least 595 records · Page 33Linked to original sources
PubMed2003

Targeted expression of the dominant-negative FGFR4a in the eye using Xrx1A regulatory sequences interferes with normal retinal development.

Molecular analysis of vertebrate eye development has been hampered by the availability of sequences that can selectively direct gene expression in the developing eye. We report the characterization of the regulatory sequences of the Xenopus laevis Rx1A gene that can direct gene expression in the retinal progenitor cells. We have used these sequences to investigate the role of Fibroblast Growth Factor (FGF) signaling in the development of retinal cell types. FGFs are signaling molecules that are crucial for correct patterning of the embryo and that play important roles in the development of several embryonic tissues. FGFs and their receptors are expressed in the developing retina, and FGF receptor-mediated signaling has been implicated to have a role in the specification and survival of retinal cell types. We investigated the role of FGF signaling mediated by FGF receptor 4a in the development of retinal cell types in Xenopus laevis. For this purpose, we have made transgenic Xenopus tadpoles in which the dominant-negative FGFR4a (Delta FGFR4a) coding region was linked to the newly characterized regulatory sequences of the Xrx1A gene. We found that the expression of Delta FGFR4a in retinal progenitor cells results in abnormal retinal development. The retinas of transgenic animals expressing Delta FGFR4a show disorganized cell layering and specifically lack photoreceptor cells. These experiments show that FGFR4a-mediated FGF signaling is necessary for the correct specification of retinal cell types. Furthermore, they demonstrate that constructs using Xrx1A regulatory sequences are excellent tools with which to study the developmental processes involved in retinal formation.

Animals↗
PubMed2003

Diabetes enhances lipopolysaccharide-induced cardiac toxicity in the mouse model.

Diabetic patients have a higher rate of mortality from sepsis than do their nondiabetic septic counterparts. The hypothesis in this study is that chronic diabetes may make cardiovascular systems more sensitive to septicemia. To test this hypothesis, the authors investigated the effect of diabetes on endotoxin- induced cardiac toxicity. Diabetes was induced in FVB mice by injecting a single dose (150 mg/kg) of streptozotocin. Two months after streptozotocin treatment, the diabetic mice were treated with lipopolysaccharide by intraperitoneal injection at 2 mg/kg. Cardiac toxicity was evaluated by measuring levels of serum cardiac enzymes and cardiac morphology at 1 h, 4.5 h, and 24 h after lipopolysaccharide treatment. Serum and cardiac tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were detected by enzyme-linked immunosorbent assay methods at 1 h and 4.5 h after lipopolysaccharide treatment. Lipopolysaccharide treatment did not significantly affect the diabetic manifestations, including decreased body weight gain and increased glycated hemoglobin and serum triglyceride levels. However, diabetes significantly enhanced lipopolysaccharide-induced cardiac toxicity, which was demonstrated by significant increases in the levels of cardiac enzymes such as creatine phosphokinase and troponin T, abnormal morphological changes examined under light microscope with hematoxylin and eosin staining, and oxidative damage to proteins detected by 3-nitrotyrosine staining. Lipopolysaccharide treatment significantly increased serum and cardiac TNF-alpha and IL-6 concentrations. Diabetes did not alter the effect of lipopolysaccharide on serum and cardiac TNF-alpha elevation, but it significantly enhanced lipopolysaccharideinduced cardiac IL-6 production. These results suggest that diabetes significantly enhances endotoxin-induced cardiac toxicity, possibly through mechanisms that involve inflammatory/acute-phase cytokines.

Animals↗
PubMed2003

Expression of local renin and angiotensinogen mRNA in cirrhotic portal hypertensive patient.

AIM: To investigate the expression of local renin and angiotensinogen mRNA in cirrhotic portal hypertensive patients. METHODS: The expression of local renin and angiotensinogen mRNA in the liver, splenic artery and vein of PH patients was detected by RT-PCR analysis. RESULTS: Expression of local renin mRNA in the liver of control group was (0.19+/-0.11), significantly lower than that in splenic artery (0.45+/-0.17) or splenic vein(0.39+/-0.12) respectively, (P<0.05). Expression of local angiotensinogen mRNA in the liver was (0.64+/-0.21), significantly higher than that in splenic artery(0.41+/-0.15) or in splenic vein (0.35+/-0.18) respectively, (P<0.05). Expression of local renin mRNA in the liver, splenic artery and vein of PH group was (0.78+/-0.28), (0.86+/-0.35) and (0.81+/-0.22) respectively, significantly higher than that in the control group, (P<0.05). Expression of local angiotensinogen mRNA in the liver, splenic artery and vein of PH group was (0.96+/-0.25), (0.83+/-0.18) and (0.79+/-0.23) respectively, significantly higher than that in the control group, (P<0.05). There was no significant difference between the liver, splenic artery and vein in the expression of local renin or local angiotensinogen mRNA in PH group, (P<0.05). CONCLUSION: In normal subjects the expression of local renin and angiotensinogen mRNA was organ specific, but with increase of the expression of LRAS, the organ-specificity became lost in cirrhotic patients. LRAS may contribute to increased resistance of portal vein with liver and formation of splanchnic vasculopathy.

Adult↗
PubMed2003

FT-IR spectroscopic analysis of normal and cancerous tissues of esophagus.

AIM: To investigate the special Fourier transform infrared spectroscopy (FT-IR) spectra in normal and cancerous tissues of esophagus. METHODS: Twenty-seven pairs of normal and cancerous tissues of esophagus were studied by using FT-IR and the special spectra characteristics were analyzed in different tissues. RESULTS: Different spectra were found in normal and cancerous tissues. The peak at 1 550/cm was weak and wide in cancerous tissues but strong and high in normal tissues. The ratio of I 1 647/I 1 550 was 2.0 in normal tissues and 2.36 in cancerous tissues (P<0.05). The ratio of I 1 550/I 1 080 was 4.5 in normal tissues and 3.4 in cancerous tissues (P<0.01). The peak at 1453 /cm was higher than at 1 402/cm in normal tissue and lower than at 1 402/cm in cancerous tissues. CONCLUSION: The results indicate that FTIR may be used in clinical diagnosis.

Case-Control Studies↗
PubMed2003

[Study on the association of cholesteryl ester transfer protein gene mutations with the susceptibility to coronary atherosclerotic heart disease].

OBJECTIVE: To determine the frequencies of 4 mutations of cholesteryl ester transfer protein (CETP) gene in Chinese population and to investigate the association of the mutations with lipid metabolism and the susceptibility to coronary atherosclerotic heart disease (CHD). METHODS: The target fragments of CETP gene were amplified and analyzed by PCR-restriction fragment length polymorphism technique in 209 unrelated control individuals and 203 CHD patients. The test for Hardy-Weinberg equilibrium was performed using HWE program and statistical analysis was implemented in statistical package SPSS. RESULTS: IVS14A and 451Q mutant genes were not found in either control group or patient group. The frequencies of 405V mutant allele were 0.443 and 0.413 in controls and patients, respectively, while 442G mutant gene frequencies were 0.007 and 0.025, respectively. The observed allele frequencies of I405V and D442G mutation were in accord with Hardy-Weinberg equilibrium. The frequency of 442G mutant gene in patients was significantly higher than that in controls (P=0.043). Compared with the CHD patients without D442G mutation, the 442G heterozygous CHD patients exhibited a significant increase in plasma TC and LDL-C concentration (P=0.017; P=0.041). CONCLUSION: IVS14A and 451Q mutants of CETP gene were rare in Chinese population and 442G mutant gene was possibly one of the susceptibility factors to CHD in Chinese.

Aged↗
PubMed2003

[Safety of an E1B deleted adenovirus administered intratumorally to patients with cancer].

BACKGROUND & OBJECTIVE: In recent years, great development has been made in cancer therapeutics with replication-competent viruses (oncolytic viruses). Genetically modified adenovirus is one of promising viruses. The current study was designed to evaluate the safety of intratumoral H101, an E1B deleted adenovirus. METHODS: A total of 15 patients with malignant tumors were treated with H101 in a dose-escalation manner (from 5 x 10(7) VP to 1.5 x 10(12) VP per day for 5 consecutive days). Systemic examination was performed prior to injection. Physical signs (including weight, temperature, respiration,pulse, and blood pressure) and toxicity were observed and recorded carefully during treatment. Adenoviral DNA in plasma, urine, and swabs of oropharynx, swabs of the injection site from different time-point were determined by PCR. RESULTS: Evaluation of toxicity in all 15 cases was available. All patients tolerated well following intratumoral injection of H101. Dose limited toxicity (DLT) and serious adverse event (SAE) were not found in the course of treatment. Main side effects were injection site pain (60.0%) and fever (33.3%). Adenoviral DNA was undetectable in plasma, urine, and swabs of oropharynx, swabs of the injection site. CONCLUSION: This study showed that the toxicities of intratumoral injection of E1B deleted adenovirus (H101) were lower and tolerable. There is no evidence indicating the invasion. These results suggested that intratumorally injected H101 is safe.

Adenoviridae↗
PubMed2003

[Study on the association of lecithin cholesterol acyltransferase gene polymorphisms with the lipid metabolism in coronary atherosclerotic heart disease].

OBJECTIVE: To examine the distribution of 3 polymorphisms of lecithin cholesterol acyltransferase gene in Chinese population and the association of these polymorphisms with lipid metabolism in patients with atherosclerotic heart disease (CHD). METHODS: Genotypes and frequencies of 3 sites were examined by PCR-restriction fragment length polymorphism technique in 209 unrelated normal control individuals and 203 CHD patients. RESULTS: The observed allele frequencies conform well to Hardy-Weinberg equilibrium. The frequency of 608T allele was significantly higher in controls than that in patients (P=0.034). Compared with the CHD patients without 608T, the CHD patients with 608T exhibited a significant increase in plasma HDL-C concentration (P=0.015). 911T/C and 1188C/T polymorphisms were not found in either group. CONCLUSION: 608T polymorphism of LCAT gene was associated with higher plasma HDL-C level in CHD patients, while 911T/C and 1188C/T polymorphisms maybe very rare in Chinese population.

Alleles↗
PubMed2003

[Study on sperm quality of the soldiers influenced by reinforced training].

OBJECTIVES: To investigate the correlation between abnormal sperm parameters and reproductive hormones and reinforced training. METHODS: Epidemic investigation were done between two different groups by determining endocrine hormone and standard clinical sperm analysis. RESULTS: Comparison between reinforced training group and non-training group showed decreased sperm velocity but no change on sperm moving form, increased teratism sperm percentage but no change on sperm number, decreased plasma testosterone but no change on LH. CONCLUSIONS: Reinforced training has correlation with weak part of sperm parameter analysis and reproductive hormones.

Humans↗
PubMed2003

[Preliminary outcome for patients with relapsed or resistant advanced non-Hodgkin's lymphoma treated by EPOCH regimen].

BACKGROUND & OBJECTIVE: In the management of relapsed or refractory non-Hodgkin's lymphoma(NHL), there is still no standard salvage chemotherapy regimen so far. Potentiation of effectiveness and reduction of toxicity for some anti-cancer agents through continuous intravenous infusion were shown in some pre-clinical and clinical studies. The purpose of this study was to evaluate the efficacy and toxicity of EPOCH regimen. METHODS: A prospective phase II study of EPOCH regimen (doxorubicin/epirubicin,vincristine,etoposide over 96 hours infusion with bolus cyclophosphamade and oral prednisone) was administered to 26 patients with relapsed or refractory/resistant aggressive NHL. There were 20 patients (84.7%) among them treated by over 2 kinds of chemotherapy regimen with median regimen types of 2 (range,1-6 types) and median chemotherapy cycles of 8 (range,3-16 cycles) given for all patients. Fifteen patients (65.7%) were chemo-resistant recurrence. RESULTS: All the 26 patients were assessable. The response rate for the whole group was 50.0% with complete remission (CR) rate of 19.2%. Among the 7 patients with T-cell lymphoma and the 19 patients with B-cell lymphoma, the response rates were 28.6% and 57.9%,respectively. Major toxicity was myelosuppression with 34.8% and 8.7%incidence of grade III-IV neutropenia and thrombocytopenia respectively in all 46 cycles of EPOCH. Other toxicities were mild. CONCLUSION: EPOCH was effective for the patients with relapsed or refractory/resistant aggressive non-Hodgkin's lymphoma. Continuous infusion schedules of several chemotherapeutic agents may partially reverse chemo-resistance and reduce toxicity. EPOCH can be used as standard salvage regimen. Further clinical study is warranted.

Adolescent↗
PubMed2003

[Estimation of isoprene emission from forest ecosystems in China].

Non-methane hydrocarbon (NMHC) emission from plants significantly affects the atmospheric environment change. Isoprene is the main NMHC in the troposphere. With the light-temperature model put forward by Guenther, isoprene emission from Chinese forest ecosystem was estimated. The result showed that the total isoprene emission was 0.03-8.6 Tg/a and release 0.026-7.589 TgC/a, which is 1.5%-4.3% of the global one. Isoprene emission has largely spatial variation, and the higher emissions occur in Southern and Northeast parts of China, where large forests are distributed. Yunnan and Heilongjiang are two higher emission provinces of China, and their contributions to the total are about 22% and 11%. The contribution varied with different species. The emissions from poplar and oak forests contribute 52.28% and 44.29% of the total, respectively.

Butadienes↗
PubMed2003

[Relationship among soil enzyme activities, vegetation state, and soil chemical properties of coal cinder yard].

From field investigation and laboratory analysis, the relationships among soil enzyme activities, vegetation state and soil chemical properties of coal cinder yard in thermal power station were studied. The results showed that vegetation on coal cinder yard was distributed in scattered patch mainly with single species of plant, and herbs were the dominant species. At the same time, the activity of three soil enzymes had a stronger relativity to environment conditions, such as vegetation state and soil chemical properties. The sensitivity of three soil enzymes to environmental stress was in order of urease > sucrase > catalase. The relativity of three soil enzymes to environmental factor was in order of sucrase > urease > catalase. Because of urease being the most susceptible enzyme to environmental conditions, and it was marked or utmost marked interrelated with vegetation state and soil chemical properties, urease activity could be used as an indicator for the reclamation of wasteland.

Cadmium↗
PubMed2003

[Association of HMG-CoA reductase gene polymorphism with levels of lipids].

OBJECTIVE: To study the distribution of ScrF1 restriction polymorphism in intron 2 of the 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA) reductase gene in Chinese Han population and the association of the polymorphism with coronary heart disease(CHD). METHODS: HMG-CoA reductase genotyping was performed using polymerase chain reaction-restriction fragment polymorphism. RESULTS: HMG-CoA reductase allelic frequencies of A, a were 0.519, 0.481; 0.440, 0.560 in CHD group and control group respectively. There was no significant difference in frequencies of allele and genotype in ScrF1 polymorphism between CHD group and control group(P>0.05). However, the levels of plasma very low density lipoprotein (VLDL) and TG in CHD patients with AA genotype were higher than those in CHD patients with other genotypes(P<0.05). The frequencies of A, a alleles at ScrF1 polymorphic site were significantly different from those reported in European Caucasians (0.44 vs 0.55, 0.56 vs 0.45, P<0.05). CONCLUSION: No direct association was found between the ScrF1 polymorphism and CHD, but there is a significant correlation between the AA genotype of the HMG-CoA reductase gene and the levels of plasma VLDL and TG in CHD group.

Adult↗
PubMed2003

[Experimental study of apoptosis and proliferation of gastric mucosal cells in chronic atrophic gastritis].

OBJECTIVE: To study the relationship between long-term high-salt hot diet and chronic atrophic gastritis (CAG). The expression of apoptosis cells, proliferation cells, bcl-2 and Fas proteins were detected in the gastric mucosa of CAG rates induced by high-salt hot water. METHODS: TUNEL technique and immunohistochemical method were used in the experiment. Flow cytometry method was used to detect the DNA content of apoptosis cells. RESULTS: (1) The detection of apoptosis with TUNEL showed that the apoptosis cells in CAG rates induced by high-salt hot water were high. These cells could be seen in all layers of gastric mucosa, apoptosis index of model rates was higher than that of normal rates (P < 0.05). (2) The result of detecting apoptosis gene and proliferating cell nuclear antigen (PCNA) by immunohistochemical method showed that the expression of bcl-2, Fas and PCNA in the CAG rates induced by high-salt hot water was much higher than that of normal gastric mucosa (P < 0.05). The expression rates of bcl-2, Fas proteins were higher with time going on. After being given high-salt hot water intragastrically for 4, 8, 12 weeks, the bcl-2 protein expression rates were 12.5%, 16.7%, 76.5%, the Fas protein expression rates were 18.7%, 22.2% and 64.7%. (3) Flow cytometry technique showed that there was a second G(0)/G(1) peek, which was apoptosis cells peak, but was not seen in the normal gastric mucosa. CONCLUSIONS: Abnormality of proliferation and apoptosis in gastric mucosa could be induced by high-salt hot water. bcl-2, Fas gene played an important role in this course.

Animals↗
PubMed2003

Antisense oligodeoxynucleotide inhibits vascular endothelial growth factor expression in U937 foam cells.

AIM: To study the expression of vascular endothelial growth factor (VEGF) induced by oxidized low density liporotein (ox-LDL) and the inhibitory effects of antisense oligodeoxynucleotide (asODN) on the levels of VEGF protein and mRNA in the U937 foam cells. METHODS: U937 cells were incubated with ox-LDL 80 mg/L for 48 h, then, the foam cells were treated with asODN (0, 5, 10, and 20 micromol/L). The VEGF concentration in the media was determined by ELISA. The VEGF protein expression level in cells was measured by immuohistochemistry; the positive ratio detected by a morphometrical analysis system was used as the amount of the VEGF expression level. The VEGF mRNA level was examined by Northern blotting. RESULTS: After U937 cells were incubated with ox-LDL, VEGF expression level increased greatly both in the cells and in the media. asODN markedly inhibited the increase of VEGF. After treatment with asODN 20 micromol/L, the VEGF protein concentration in the media decreased by 45.0%, the VEGF positive ratio detected by immuohistochemistry in cells decreased by 64.9%, and the VEGF mRNA level decreased by 47.1%. CONCLUSION: The expression of VEGF in U937 foam cells was strong. asODN inhibited VEGF expression significantly in U937 foam cells in vitro.

Foam Cells↗
PubMed2003

[Analysis of correlation between parameters of sperm chromatin structure assay and semen routine analysis].

OBJECTIVES: To analysis the correlation between parameters of sperm chromatin structure assay(SCSA) and semen routine analysis, and to discuss the reliable methods of semen quality evaluation. METHODS: Five hundred and eleven semen samples were detected to analyse the mutiple-parameter correlation between results of SCSA (COMP alpha t) and semen routine analysis. RESULTS: The parameters that have low-level positive correlation(r: 0.10-0.30) with denatured sperm percentage(COMP alpha t) were viscosity, ejaculation interval, abnormal sperm ratio, concentration of grade c sperm; those having low-level negative correlation(r: -0.30(-)-0.10) were VDL, VSL and VAP; those having mid-level positive correlation (r: 0.30-0.70) were sperm concentration, percentage of grade d sperm; those having mid-level negative correlation (r: -0.70(-)-0.30) were MAD, percentage of grade a sperm and survival rate. CONCLUSIONS: Flow cytometry can be used to evaluate the percentage of denatured or injured sperm rapidly, correctly and simply. The result (COMP alpha t) correlates partly with semen parameters, and it is not a conclusively parameter compared with routine semen analysis. It is important to use SCSA to evaluate productivity under the above situation.

Adult↗
PubMed2003

[Survey of knowledge, attitude and behavior regarding safe injection among health practitioners in Shandong, China].

PURPOSE: To assess the knowledge, attitude and behavior of health practitioners (HPs) about safe injection in Shandong, China and to clarify risk factors related to unsafe injection and improper handling of used disposable syringes. METHODS: A cross-sectional study of 497 HPs in three-levels of health units (village clinic, township health center, and county hospital) in two areas of Shandong, China was carried out using a questionnaire. RESULTS: 468 HPs returned completed questionnaires. The proportion that did not receive formal medical education in the village (21.5%) was higher than in the township (9.9%) and in the county (2.5%). Proportions of HPs who only used disposable syringes were 97.0% in the county, 81.1% in the township and 69.0% in the village. Scores for safe injection knowledge among village HPs were significantly lower than those with township and county HPs (P < 0.001). Rate of unsafe injection practice was 6.2%, rate of improper handling of used disposable syringes was 7.6%, and both of which were significantly greater at the village level. Four factors were found to be significantly related to unsafe injection practice (P < 0.05): lower than middle level professional grade; knowledge scores of < 15 (full score 18); thinking that AIDS is not a terrible disease; and thinking that patients would accept the practice of sharing the same syringe for different persons. Four factors were found to be significantly related to improper handling of used disposable syringes (P < 0.05): working in the village; knowledge scores of < 15; thinking that patients would accept the practice of sharing the same syringe for different persons; and unwillingness to properly handle used disposable syringes. CONCLUSIONS: HPs working in village clinics had comparatively high rates of unsafe injection practice and improper handling of used disposable syringes, and a lower level of knowledge about safe injection. Lack of knowledge about safe injection was a risk factor for both unsafe injection and improper handling of used disposable syringe. Therefore, interventions should focus on this insufficient level of safe injection knowledge.

Adult↗