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Biomedical subjects

Li Zhang

Publications and source records attributed to Li Zhang.

At least 631 records · Page 35Linked to original sources
PubMed2003

[Studies of the association between angiotensinogen gene regulation and cytokines in essential hypertension].

This study is to explore the association between M235T allele polymorphism of angiotensinogen (AGT) gene and cytokines using essential hypertension probands research method. In hypertensives and controls, polymerase chain reaction combined with restriction endonuclease digestion was used to detect the target genotype variation, and enzyme-lined immunosorbant assay (ELISA) was used to detect the cytokine concentrations (IL-1, IL-6, TNF). The results showed that in hypertensives AGT gene, TT genotype was 55.88%, MT 35.29% and MM 8.82%. The ratio of T/M allele frequency was 0.735/0.265. In controls AGT gene, TT genotype was 47.46%, MT 42.37% and MM 10.17%. The ratio of T/M allele frequency was 0.686/0.314. AGT gene 235 T allele frequency in hypertensives was slightly higher than those in controls. Furthermore AGT gene 235 TT genotype and T allele frequency in middle and high grade of hypertensives were significantly higher than those in mild grade. In subjects of AGT 235 T allele group, the concentrations of IL-1, IL-6 and TNF in hypertensives were significantly higher than those in controls. In subjects of AGT gene 235 M allele frequency, the concentrations of IL-1 and IL-6 in hypertensives were no significant than those in controls. No matter in groups more than 60 years old or less than 60 years old, the concentrations of IL-1, IL-6 and TNF in hypertensives were higher than those in controls. No matter in hypertensives or controls, there were no differences in concentrations of IL-1, IL-6 and TNF when comparing groups more than 60 years old with groups less than 60 years old. The study indicated that AGT gene TT genotype and AGT gene 235 T allele frequency may be an important risk factor for hypertension. The high frequency of AGT gene 235 T allele and the high concentrations of IL-1, IL-6 and TNF in hypertensives may cause hypertension developing. It is also suggested the cytokines may effect the transcription and expression of AGT gene 235 TT genotype in hypertension. The concentrations of IL-1, IL-6 and TNF had nothing to do with age no matter hypertensives or controls.

Adult↗
PubMed2003

[Effects of tobacco on proliferation and attachment of human periodontal ligament fibroblast].

OBJECTIVE: To evaluate the effects of nicotine and tobacco extract (ST) on PDLFs morphology, structure, proliferation and attachment. METHODS: PDLFs were cultured in the presence of nicotine and ST at various concentration. The cell changes in the morphology and structure were examined by histological and transmission electrical microscope (TEM). The growth and attachment of cell were measured by MTT method. RESULTS: The size of the cells became smaller gradually and their shapes changed from shuttle type to oval or round when the concentration of nicotine and ST increased, the polarity of the cells was in disorder, ultrastructure showed that the organelles, especially rough-surfaced endoplasmic reticulum and golgi complex decreased in number, microtubule and microfilaments were disassembled, the nuclei became fewer or shrunk, the growth and attachment were dose-dependently inhibited. CONCLUSIONS: Nicotine and ST can change PDLFs' morphology and structure, they may inhibit the growth and attachment through disruption of the cytoskeleton, suggesting nicotine and ST may have pathological role on human periodontitis.

Cell Adhesion↗
PubMed2003

[Campto (CPT-11) treatment of advanced large intestinal cancer: clinical experience].

OBJECTIVE: To evaluate the efficacy and toxicity of campto (CPT-11) monotherapy or combined with 5Fu + leucovorin (CF) in advanced large intestinal cancer. METHODS: 186 such patients were divided into campto monotherapy group and CPT-11 plus 5Fu + CF [De Gramont (DGM) or Mayo protocal] groups. The mean dose of CPT-11 was 270 mg/m(2) alone in the monotherapy group and 150 mg/m(2) in the combination group. Campto was given as iv infusion in no less than 30-minutes. RESULTS: 186 patients were eligible for response evaluation. The response rates were 27.9% in the monotherapy group, 32.7% in CPT-11 + DGM and 27.3% in CPT-11 + Mayo group. For 55 untreated patients, the response rates of monotherapy, Campto + DGM and Campto + Mayo regime groups were 33.3%, 28.9% and 50.0%. For 131 treated patients, they were 26.4%, 34.8% and 22.2%, respectively. The toxicities of the whole group were 16.0% cholinergic syndrome, 51.9% delayed diarrhea and 19.8% leucopenia. There were 2 treatment-related deaths. CONCLUSION: The efficacy and toxicities of campto are similar as compared with the reports by other investigators.

Adult↗
PubMed2003

[The quantity analysis of reverse transcriptase in porcine endogenous retrovirus expressed in Banna minipig inbred].

Quantitative RT(reverse transcriptase) assay was established to detect the reverse transcriptase in plasma of thirty-four Chinese Banna minipig inbred in this work. The protocol was given in the RT kit (Roche), using HIV-1 as the positive control of the kit and supernatant of PK-15 as the PERV positive control respectively. The results show that positive reverse transcriptase reaction can be detected in the plasma of the pigs, but the levels are much lower than that of HIV-1 and lower than that of PERV in supernatant of PK-15.

Animals↗
PubMed2003

[Inhibitory effects on hepatocarcinoma and B16 melanoma cells by N-(4-hydrophenyl) retinamide].

In this paper, a significantly effect of N-(4-hydrophenyl) retinamide (4-HPR), a derivative of retinoic acid, was observed on inhibition of migration, invasion, cell growth, and induction of apoptosis in hepatoma cells and B16 melanoma cells. The number of migratory hepatoma cells reduced significantly from the control 201 +/- 27.2 to 58 +/- 5.03 after 6-hour incubation with 4-HPR (p < 0.01, n = 4). The number of migratory B16 melanoma cells reduced from the control 302 +/- 30.1 to 254 +/- 25.04 (p < 0.05, n = 4). The invasive ability of these cells was also suppressed by 4-HPR treatment. Cells that penetrated the artificial membrane matrigel decreased from 27 +/- 13.1 to 11.2 +/- 3.3 in hepatoma cells, from 67.5 +/- 10.1 to 24.3 +/- 3.2 in B16 melanoma cells (p < 0.05, n = 3). Furthermore, cell growth was significantly inhibited especially in B16 melanoma cells and 37.11 +/- 0.94% cells were induced to apoptosis after 48-hour induction by 4-HPR, which was significantly higher than those by retinoic acid treatment (p < 0.05). Although the mechanism of 4-HPR effects was not very clear, over expression of CST, which was inhibited by 4-HPR in our previous study, could diminish the apoptosis--inducing effect by 4-HPR. We believe that 4-HPR has a strong inhibitory effect on melanoma and hepatocarcinoma cells and might become a potent therapeutic agent.

Animals↗
PubMed2003

[Reserpine-induced supersensitivity and alpha 1-adrenoceptor subtypes].

Supersensitivity is one of classical and pharmacological phenomena, and may be caused by a variety of procedures, including surgical and chemical denervation and chronic treatment with antagonists. We examined reserpine-induced chemical denervation supersensitivity with special reference to arterial alpha 1-adrenoceptor (alpha 1-AR) subtypes. Chronic treatment with reserpine for 2 weeks produced supersensitivity in the contractile response to phenylephrine of isolated rat tail artery, resulting a leftward shift of concentration-response curve (10 fold shift at EC50 value). This supersensitivity in reserpine-treated artery was selectively inhibited by BMY7378 (alpha 1D-AR selective antagonist) but not by KMD-3213 (alpha 1A-AR selective antagonist). On the other hand, the response to phenylephrine in reserpine-untreated artery was inhibited by KMD-3213 but not by BMY7378. Tissue segment binding study with 3H-prazosin revealed that high affinity binding sites for BMY7378 were detected with a proportion of 32% in reserpine-treated tail artery but absent in untreated artery, although total density of alpha 1-ARs was not changed by reserpine-treatment. The present results strongly suggest that reserpine-induced supersensitivity of rat tail artery is caused by a selective induction of alpha 1D-AR subtype.

Animals↗
PubMed2003

[Transvaginal follicular aspiration in follicle phase in the management of anovulation associated with polycystic ovary syndrome].

OBJECTIVE: To investigate the follicle development and pregnancy in clomiphene citrate-resistant patients with polycystic ovary syndrome (PCOS) after transvaginal follicular aspiration and gonadotropin administration. METHODS: Seventeen clomiphene citrate-resistant patients with PCOS failed to gonadotropin treatment associated with ovarian hyperstimulation syndrome (OHSS). They are anovulatory infertility with normal tubal and husbands' sperm condition. In this treatment regimen, all patients was administered with gonadotropin from day 5 of menstrual cycle (or withdrawal bleeding) and were asked to undergo ultrasound-guided transvaginal follicular aspirations for 5 days later. Only one or two follicles for every ovary were remained and gonadotropin administration was continued. A follicle development, ovulation rate, pregnancy rate and sex hormone were monitored. RESULTS: Fifteen of the 17 patients experienced dominant follicles development and ovulation. 9 of them with one (52.9%), 4 with two (23.5%) and 2 with three (11.8%) dominant follicles ovulated and pregnancy occurred in 7 patients (41.2%). All of pregnancy are singleton. CONCLUSION: A single follicle development and singleton pregnancy can be realized in clomiphene citrate-resistant PCOS patients by combined ultrasound-guided transvaginal follicular asperation with gonadotropin administration.

Adult↗
PubMed2003

[The effect of overtraining on human sperm chromatin structure].

OBJECTIVE: To identify the effects of overtraining on human sperm DNA. METHODS: Molecular epidemiological investigation of 249 men from different groups (training and non-training) was carried out by using flow cytometer to detect the integrity and damage of in situ DNA of sperm nucleus, and sperm chromatin structure assay was performed. RESULTS: The average COMPalpha(t) in training group was 11.02% while that in control group was 5.90% (P < 0.01). COMPalpha(t) was significantly correlated with sperm activity (r = 0.41, P < 0.05). CONCLUSION: Overtraining could induce sperm DNA injury and affect sperm activity, thus to decrease the potentiality of reproduction.

Adult↗
PubMed2003

[An analysis of the state of teeth of 961 elderly cadres in Shenyang City].

OBJECTIVE: To assess the current state of teeth in elderly cadres in Shenyang City. METHODS: According to the standards of the 2nd national oral health sampling survey, 961 elderly cadres, above 60 years old, were examined. The results were processed using SPSS. RESULTS: 67.12% had dental caries and among them 33.18% were completely treated. The mean numbers of decayed and filled teeth in persons with caries become higher with the increase of ages (P<0.05). 80.65% of individuals had lost partial or all of their teeth. The mean number of lost teeth was 7.38. The number of teeth present had a negative correlation to ages (P<0.01). The state of periodontal health also had a negative correlation to ages(P<0.01). 10.20% was the edentate and 98.98% of them were wearing complete dentures. Among the elderly with part of their teeth lost, 36.04% had prosthetic restoration. CONCLUSION: Teeth loss is common in elderly population. Dental caries and periodontal diseases are two main causes. To increase the treatment rates of dental disease, it is evident to improve the oral health awareness in elder persons.

Age Factors↗
PubMed2003

[Indentification of differentially expressed genes in proliferating and involuting hemangiomas by cDAN microarray analysis of gene-expression profiles].

OBJECTIVE: To investigate the differentially expressed genes of proliferating and involuting hemangiomas by cDNA microarray analysis of gene-expression profiles in an effort to identify the key disease-related genes. METHODS: Samples were processed from total RNA and purified to mRNA, which was reverse-transcripted and hybridized onto Biodoor Genechip expression microarrays. Analyses were performed to determine the consensus pattern of gene expression in the proliferating and involuting stages of the same hemangioma and the changes in the expression level. RESULTS: In proliferating hemangioma, 79 genes were overexpressed, and 115 genes were underexpressed in comparison with the involuting hemangioma. Some cytokines and growth factors such as neurotensin, Nov, CYR6, keratinocyte growth factor, interleukin-10 were overexpressed in proliferative hemangioma. In involuting hemangioma, apoptotic factors such as bcl-2 binding component, cytochrome C were overexpressed. The overexpression of Nov, CYR6, c-myc implied that angiogenesis and oncogenes might participate in the pathogenesis of hemangiomas. Mitochondria activated apoptotic passage (cytokines, bcl-2, cytochrome C) and Wnt/beta-catenin passage(Frizzled, beta-catenin, c-myc) were involved. CONCLUSION: The development of hemangiomas may be the results of imbalance of cell proliferation and apoptosis.

Apoptosis↗
PubMed2003

[Experimental studies on antianimia effect of shengxuesu].

OBJECTIVE: Using animal anemia models to observe the antianemia effect of Shengxuesu, and to afford an experimental basis for preventing and treating anemia. METHOD: Rat model of iron deficiency induced by denutrition and mouse model of nemorrhagic anemia by blood lefting were established. Indices of hemoglobin(HB), red blood cell count(RBC), hematocrit(HCT), mean corpuscular hemoglobin count(MCHC), serum iron(SI), serum ferritin (SF) and total iron-binding capacity(TIBC) were monitored. RESULT: A dosage of Shengxuesu 0.5-2 g.kg-1 was given to the rat model of hypoferric anemia by gavage for 15 days, and to the mouse model of hemorrhagic anemia by gavage for 7 days. The result shows that HB, RBC, HCT, MCHC in blood and iron, ferroprotein in serum were elevated significantly; but total bounding iron in serum was decreased. Meanwhile, diet amount, diet consumption and general activity of the model rats were increased.

Anemia, Hemolytic↗
PubMed2003

[Yixintong tablet's protection against experimental myocardial ischemia].

OBJECTIVE: Various models of experimental myocardial ischemia were set up to ovbserve the Yixinton's protection against ischemia. METHOD: Models of experimentally acute myocardial ischemia were made by ligature or medication (pituitrin or isoprenaline) to check the indices of ECG, hemodynamics, and morphology. RESULT: A dosage of Yixintong tablets 100 mg/kg, 200 mg/kg was given to rats by gavage; the rats had undergone a thirty-minute ligatute of coronary lef anterior descending branch, and used as a model of ischemic reperfusion. The observations showed that Yixintong tablets exerted a recovery effect on heart rate, blood pressure, internal pressure of left ventricule and its peak/trough rate (+/- dp/dtmax), and ST segment (electrocardiogram). The tablet markedly reduced the myocardial infarct size of the coronary-ligatured rats. The tablet benefited the rats with pituitrin(iv)- or isoprenaline(ip)-induced acute myocardial ischemia to reverse any ST deviation and T-wave fall. CONCLUSION: Yixintong has a protective and therapeutic action to the experimental myocardial ischemia.

Animals↗
PubMed2003

[Construction and expression of recombinant antibody/granzyme B containing truncated translocating peptide].

AIM: To construct an eukaryotic expression vector for recombinant antibody/granzyme B gene containing truncated translocating peptide and express it in HER-2(+) SKBR-3 cells and HER-2(-) Hela cells. METHODS: PCR amplication was used to obtain recombinant DNA encoding antibody/granzyme B containing truncated translocating peptide DNA, and then the DNA fragment was cloned into eukaryotic expression vector pCMV-e23sFv-PE40. After being transfected into SKBR-3 cells and Hela cells, the expression of target gene and its effect on cellular morphology were detected by immunocytochemical staining. RESULTS: The eukaryotic expression vector encoding recombinant antibody/granzyme B containing truncated translocating peptide was successfully constructed. e23sFv-FSD-GrB protein was expressed in most of Hela cells and had no effect on Hela cells, but the transfected SKBR-3 cells which also express e23sFv-FSD-GrB protein exhibited condensed nucleus and cytoplasm. CONCLUSION: The construction of eukaryotic expression vector of recombinant antibody/granzyme B gene containing truncated translocating peptide lays the foundation for further determination of minimal fragment responsible for translocation.

ADP Ribose Transferases↗
PubMed2003

[Feeding of mixed-carbon-resource during the expression phase in cultivation of recombinant Pichia pastoris expressing angiostatin].

A recombinant strain of Pichia pastoris with a phenotype of Muts was used to produce angiostatin in a 5-L fermentor. The methanol utilization ability of the present strain was weak, which resulted in extremely low growth rate and angiostatin productivity during the expression phase with methanol as the sole carbon source. To enhance the cell density and angiostatin expression level, mixed-carbon-source of glycerol-methanol was used in the expression phase. The methanol concentration was well controlled at 5 g/L by a methanol sensor and control system, and glycerol was continuously fed into the fermentor to achieve a higher cell density. 120 g/L of cells and 39 mg/L of angiostatin were reached at the end of fermentation which lasted 110 h. The mean specific cell growth rate in the expression phase was 0.01 h(-1), and the mean specific angiostatin productivity was 0.006 mg/(g x h). According to the data obtained in several runs of fermentation in which glycerol was fed at different rates, a higher mean specific angiostatin productivity was reached at the mean specific cell growth rate of 0.012 h(-1). To avoid the repression of angiostatin expression caused by residual glycerol and ethanol accumulation due to overfeeding of glycerol, glycerol addition was controlled to produce continuous oscillations in dissolved oxygen, because the change of dissolved oxygen concentration could deliver the information of available carbon source in the fermentation broth. Controlled glycerol feeding also avoided the problem of oxygen limitation brought by high cell density, and thus decreased the cooling requirement of the fermentor. Cell density reached 150 g/L at the end of fermentation, and angiostatin level reached 108 mg/L after an expression period of 96 h when the mean specific growth rate was maintained at 0.012 h(-1) by using the glycerol feeding strategy to result in the oscillations in dissolved oxygen. The mean specific angiostatin productivity was improved to 0.02 mg/(g x h). The apparent cell yield on glycerol and methanol were respectively 0.69 g/g and 0.93 g/g, higher than those in the fermentation without using the feeding strategy with dissolved oxygen as the indicator of metabolism.

Angiostatins↗
PubMed2003

Fourier harmonic approach for visualizing temporal patterns of gene expression data.

DNA microarray technology provides a broad snapshot of the state of the cell by measuring the expression levels of thousands of genes simultaneously. Visualization techniques can enable the exploration and detection of patterns and relationships in a complex dataset by presenting the data in a graphical format in which the key characteristics become more apparent. The purpose of this study is to present an interactive visualization technique conveying the temporal patterns of gene expression data in a form intuitive for non-specialized end-users. The first Fourier harmonic projection (FFHP) was introduced to translate the multi-dimensional time series data into a two dimensional scatter plot. The spatial relationship of the points reflect the structure of the original dataset and relationships among clusters become two dimensional. The proposed method was tested using two published, array-derived gene expression datasets. Our results demonstrate the effectiveness of the approach.

Algorithms↗
PubMed2002

Reperfusion injury is reduced in skeletal muscle by inhibition of inducible nitric oxide synthase.

This study evaluated the effects of the selective inducible nitric oxide synthase (iNOS) inhibitor N-[3-(aminomethyl)benzyl]acetamidine (1400W) on the microcirculation in reperfused skeletal muscle. The cremaster muscles from 32 rats underwent 5 h of ischemia followed by 90 min of reperfusion. Rats received either 3 mg/kg 1400W or PBS subcutaneously before reperfusion. We found that blood flow in reperfused muscles was <45% of baseline in controls but sharply recovered to near baseline levels in 1400W-treated animals. There was a significant (P < 0.01 to P < 0.001) difference between the two groups at each time point throughout the 90 min of reperfusion. Vessel diameters remained <80% of baseline in controls during reperfusion, but recovered to the baseline level in the 1400W group by 20 min, and reached a maximum of 121 +/- 14% (mean +/- SD) of baseline in 10- to 20-micro m arterioles, 121 +/- 6% in 21- to 40-micro m arterioles, and 115 +/- 8% in 41- to 70-micro m arteries (P < 0.01 to P < 0.001). The muscle weight ratio between ischemia-reperfused (left) and non-ischemia-reperfused (right) cremaster muscles was 193 +/- 42% of normal in controls and 124 +/- 12% in the 1400W group (P < 0.001). Histology showed that neutrophil extravasation and edema were markedly reduced in 1400W-treated muscles compared with controls. We conclude that ischemia-reperfusion leads to increased generation of NO from iNOS in skeletal muscle and that the selective iNOS inhibitor 1400W reduces the negative effects of ischemia-reperfusion on vessel diameter and muscle blood flow. Thus 1400W may have therapeutic potential in treatment of ischemia-reperfusion injury.

Abdomen↗