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Biomedical subjects

D Liu

Publications and source records attributed to D Liu.

At least 289 records · Page 16Linked to original sources
PubMed2000

[The effect of Shenmai injection on the expression of TNFalpha mRNA of the macrophages in scalded mice].

OBJECTIVE: To explore the effect of Shenmai injection on the expression of TNFalpha mRNA of peritoneal macrophages in scalded mice. METHODS: BALB/c mice inflicted with 11% TBSA III degree scalding injury were employed as the model. Shenmai injection was composed of 100 mg of red ginseng and 100 mg of lily turf root in 1 ml injection solution and was administered to mice via peritoneal injection in a dose of 2.5 ml per kilogram of mice body weight per day for 5 days. The expression of TNFalpha mRNA was determined by semi-quantitative RT-PCR. RESULTS: The expression of macrophage TNFalpha mRNA was significantly increased in the scalded mice, while the expression was obviously lowered after the administration of Shenmai injection (P < 0.01) to scalded mice and the survival rate of the scalded mice was thus markedly increased (P < 0.05). CONCLUSION: The beneficial effect of Shenmai injection on the scalded mice might be related to its inhibitory effect on the hyperexpression of macrophage TNFalpha mRNA. Shenmai injection could lower down the expression of TNFalpha in scalded mice and raise the survival rate of scalded mice.

Animals↗
PubMed2000

[Role of pp60c-src in mitogen-activated protein kinase activation of vascular smooth muscle cells].

The effect of pp60c-src on mitogen-activated protein kinase (MAPK) activation induced by angiotensin II (Ang II) in vascular smooth muscle cells (VSMCs) was observed to explore the signal transduction process of VSMCs proliferation mediated by Ang II. Following transfection of the synthetic antisense c-src oligodeoxynucleotides (ODNs) wrapped in lipofectin into cultured rat VSMCs, pp60c-src content markedly decreased, pp60c-src kinase activity was only 14.4% of control, while MAPK activity was not significantly changed (P>0.05). When these transfected VSMCs were further stimulated by Ang II, the increase in MAPK activity was only 1.6% of control. These data suggest that pp60c-src is needed for MAPK activation in VSMCs stimulated by Ang II, and pp60c-src may be an important signaling molecule in abnormal proliferation of VSMCs.

Angiotensin II↗
PubMed2000

[Simultaneous intrusion and retraction of the anterior teeth using a three-piece base arch].

OBJECTIVE: To evaluate the effects of the three-piece base arch on overbite correction of Class II malocclusion. METHODS: 20 patients with high angle, flared incisors were treated using a three-piece base arch appliance. The intrusion force of four upper incisors was adjusted to approximately 50 g. The line of force action was 2 mm distally to the resistant center(RC) and the retraction force was 20 g, the right and left posterior segments were joined by a palatal bar. Cephalograms were taken before treatment (T1) and six months after treatment (T2). RESULTS: The upper molars moved mesially 0.60 +/- 0.35 mm and the distance of the vertical extrusion was 0.80 +/- 0.52 mm. The distances of the upper central incisor retraction and intrusion were -4.20 +/- 2.12 mm and 3.10 +/- 0.54 mm respectively. The RC of the central incisor retracted -4.12 +/- 1.96 mm and intruded 3.20 +/- 0.66 mm. The axial inclination of the upper incisor-palatal plane changed from 123.21 degrees +/- 4.26 degrees to 116.00 degrees +/- 3.96 degrees. CONCLUSION: The three-piece segmented approach can effectively intrude and retract the upper anterior teeth for flared incisors and deep overbite.

Adolescent↗
PubMed2000

[Pharmacodynamic effects of the extracts from Orobanche cumana].

Pharmacodynamic effects of the extracts from Orobanche cumana were studied for the first time. The result showed that it has the effects of antifatigue, facilitating immune function and an andrin-like action. It is consided that Orobanche cumana can be developed as a new medicinal resource plant.

Adjuvants, Immunologic↗
PubMed2000

[Effects of phytohormones on growth and content of depsides in Salvia miltiorrhiza suspension cells].

This paper deals with the effects of 2,4-D, BA and GA3 on the growth and content of two depsides (rosmarinic acid and lithospermic acid B) in suspension cells of Salvia miltiorrhiza. The results showed cell growth and rosmarinic acid content reached the maximum on the 12th day and lithospermic acid B content on the 16th day after incubating cells in the subculture medium MS + 2, 4-D 1 mg/L + KT 0.1 mg/L. This cell line was a growth-product-associated. With the same concentration (1 mg/L), 2, 4-D stimulated the cell growth but prohibited the formation of lithospermic acid B; GA3 inhabited the cell growth but stimulated the formation of two depsides; The effects of BA is between 2, 4-D and GA3. The concentration optimum of phytohormones tested displayed 3 mg/L for BA and 1 mg/L for GA3. For the optimum time of adding BA and GA3 was in med-term (the 8th day) and early term (at the beginning) of culture period respectively. The synergiatic function of BA and GA3 on the depside formation was also showed that adding GA3 (1 mg/L) was favour for the formation of lithospermic acid B of the suspension cell cultured in the medium containing BA 3 mg/L. The suitable time of adding GA3 was the 6the day after incubating cells in the medium of MS + BA 3 mg/L.

Benzofurans↗
PubMed2000

[The relationship between tracheotomy and intra-tracheal papilloma progression in children].

OBJECTIVE: To clarify the relationship between tracheotomy and intra-tracheal papilloma progression and introduce the experience of managing dyspnea in the hospital. METHODS: Children who were treated in ENT department of Tongren Hospital between 1992 and 1997 were reviewed in this essay. There were totally sixty-two children (thirty-two boys and thirty girls) with laryngeal papilloma and recurrent respiratory papillomatosis enroled in the series. RESULTS: Among 33 non-tracheotomied children the intra-tracheal lesions were found in only 2 cases (6.1%). There were 17 (80.9%) cases presented intra-tracheal lesions in 21 tracheotomied cases, and it showed great statistical difference (chi 2 = 27.4, P < 0.005). There were no difference of onset age, sex and the first sites of papilloma lesions between the non-tracheotomied and tracheotomied groups(P > 0.05). CONCLUSION: We found papilloma has a week potential to progress into trachea. Tracheotomy is the most important factor of intra-tracheal papilloma progression in many cases. The tracheotomy can be avoided.

Child↗
PubMed2000

[Investigation of the nasal T/NK cell lymphomas in 14 cases].

OBJECTIVE: To study the biologic behavior, pathologic features as well as clinic manifestations of the nasal T/NK cell lymphomas, and to provide experiences for the diagnosis and treatment of the tumor. METHODS: Specimens of 23 cases lethal midline granulomas (LMG) were examined: (1) HE stain for immunohistochemical staining for TIA-1, CD43, CD20, CD3 epsilon, CD56 and in situ hybridization for EBV encoded small nuclear RNA(EBER1/2, Y017, DAK0). (2) The cases histories were reviewed. RESULTS: (1) 14 cases were confirmed by histological features. In the 14 cases, tumor cells expressed TIA-1, CD56, CD3 epsilon, CD43, EBER1/2 positive. (2) Among them 8 cases (57%) showed special clinic features of LMG, Nasopharynx, pharynx and laryngeal involvement were found in other 6 cases. One case revealed lymphoid leukemia. In other 2 cases, gastrointestinal tract were involved. Hemophagocytic syndrome (HPS) complication happened in 1 case. CONCLUSION: The tumor cells of nasal T/NK cell lymphomas expressed TIA-1, CD56, CD43, CD3 epsilon may suggest it originates from NK cell. The high association with EBV may suggest in situ hybridization. 57% patients showed that the special clinic features of the LMG, and gastrointestinal tract, bone marrow, peripheral blood were involved in some cases. One case complicated with hemophagocytic syndrome (HPS).

Herpesvirus 4, Human↗
PubMed2000

[Effect of reperfusion after local ischaemia on the M receptor density in rat brains].

OBJECTIVE: To study the dynamic changes in the density of muscarinic acetylcholine receptor in different areas of rat brains during reperfusion after local ischaemia. METHODS: The rat cerebral focal ischemia/reperfusion model after middle cerebral artery occlusion was made by the intraluminal suture method. Using 3H-QNB as radioligand, after binding with M receptor on the brain slice of the rat model, the brain samples were exposed on the hypersensitive film [H-3] to complete autoradiography, and the density of M receptor in different areas on the film of autoradiography was measured. RESULTS: There were no changes in the M receptor density in 2 hours' ischaemia group and 2 hours' reperfusion group, M receptor densities in the area of occipital cortex (OC) and temporal cortex (TC) were observed to decrease significantly in 8 hours' reperfusion group, but the degree of decrease was lower than 24 hours' and 72 hours' reperfusion groups, there was significant decrease in the density of M receptor in the areas of caudate putamen (CP), frontal cortex (FC), TC, OC of the 24 hours' and 72 hours' reperfusion groups and no difference was found between these two groups, and the imaging of M receptor in the domains with decreased receptor was obvious. CONCLUSIONS: The quantity of M receptor did not change right after ischaemia or reperfusion. It decreased gradually after an interval of time; Imaging of the M receptor could assess the changes of the density of viable cholinergic neurons and be a marker of diagnosis, therapy, and prognosis of brain ischaemia.

Animals↗
PubMed2000

[Screening the trans-action factors binding to the enhancer element of rat GST-P by yeast one-hybrid system].

OBJECTIVE: To investigate the diversity of the mechanisms of rat glutathione S-transferase P (GST-P) gene expression regulation and the relation between rat GST-P gene expression and carcinogenesis. To search the trans-action factors binding to the enhancer element of rat GST-P (glutathione S-transferase P enhancer, GPE I). METHODS: We searched the trans-action factors binding to GPE I using yeast one-hybrid system, and analyzed the DNA sequence by sequencing and computer search. RESULTS: Two positive clones pYGPE1 and pYGPE2 were obtained. The homologies of the insert sequence of pYGPE1 nucleotide and amino acid sequences with rat c-jun cDNA were 99% and 100% respectively; the homologies of the insert sequence of pYGPE2 nucleotide and amino acid sequences with rat mitochondrial adenine nucleotide translocase cDNA were 99% and 100% respectively. CONCLUSIONS: Rat c-Jun and mitochondrial adenine nucleotide translocase can bind to the GPE I core sequence, and they perhaps are the trans-action factors of GPE I.

Animals↗
PubMed2000

[The diagnostic and prognostic values of assay of serum vascular endothelial growth factor in epithelial ovarian cancer].

OBJECTIVE: To detect the level of the preoperative serum vascular endothelial growth factor (VEGF) in patients with epithelial ovarian cancer, and to evaluate the correlation between preoperative serum VEGF level and prognosis of epithelial ovarian cancer. METHODS: Forty-one patients with epithelial ovarian cancer (EOC), 10 patients with borderline ovarian tumor (BOT), and 25 women with benign ovarian tumor (BET) were included as three study groups, while 20 healthy women were selected as a control group. Enzyme-linked immunosorbent assay (ELISA) was utilized to measure the serum VEGF level. RESULTS: The serum VEGF levels in patients with EOC were higher than those in patients with BOT, or with BET, or those in healthy women. The median and ranges of serum VEGF levels were as follows: EOC: median 415.0 pg/ml, range 110-2,120 pg/ml; BOT: median 312.5 pg/ml, range 100-1,250 pg/ml; BET: median 170 pg/ml, range 70-925 pg/ml; healthy women: median 165 pg/ml, range 100-735 pg/ml. When median preoperative serum VEGF levels were grouped by tumor stages, histological grade of tumor cells, histological type of the tumor, lymph node involvement, and omentum involvement, significant correlations between serum levels of VEGF and histological grade, lymph node involvement and omentum involvement were found. The patients with high serum VEGF appeared to be accompanied with poor 3-year survival. CONCLUSIONS: Preoperative serum VEGF levels seemed to be correlated with the malignant behavior of ovarian cancer, which might provide some prognostic value.

Adult↗
PubMed2000

[Study on the complex formation reactions between rare earths (La3+, Pr3+) and DBS-Arsenazo with absorption spectrophotometry].

In this paper, ways of determining the composition and formation constants for rare earths (La3+, Pr3+)-DBS-Arsenazo (2-(2-arsonophenylazo)-7-(2,6-dibromo-4-sulphophenylazo)-1,8-dihydroxy-3, 6-naphthalene-disulfonic acid) complexes were discussed. La3+ or Pr3+ (colorless) reacts with DBS-Arsenazo which absorbs at 535 nm, blue-violet products absorbing at 630 nm are formed in 1 mol.L-1 HCl solution. To study the reactions, a series of spectra of the complexes were obtained by spectrophotometric titration of DBS-Arsenazo with La3+ or Pr3+. The number of the components contributing to the color systems was obtained by using factor analysis method. It shows that only two color components are in the system. Combined with structural consideration, it is possible that the reactions is as follows: La3+ or Pr3+ + nDBS-Arsenazo = La3+ or Pr(3+)-(DBS-Arsenazo)n Coloress absorbs at 535 nm absorbs strongly at 630 nm A linear regression method was proposed to determine the compositions, the formation constants and the concentration of the color reagent. The results show that La3+ or Pr3+ reacts with DBS-Arsenazo, and form 1:3 complexes in 1 mol.L-1 HCl solution. The conditional formation constants (log beta 3) determined are 15.36 and 15.34 respectively.

Arsenazo III↗
PubMed2000

[Acid extraction of coal for the determination of major ash forming elements by ICP-AES].

A new method is described for the analysis of whole coal for the major ash forming elements by ICP-AES. The major ash forming elements were extracted with HF and HNO3 in an ultrasonic water bathe. The best proportion of the acid and the time of extraction were studied. Compared with the ash content of coal, the extraction ratio is more than 95%. Recovery ratio is between 96%-104%. RSD of extraction and determination is less than 4% (n = 9).

English Abstract↗
PubMed2000

[Simultaneous determination of La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+ in their mixtures by multi-system multi-wavelength computational spectrophotometry].

Since the spectra of the rare earth color complexes are rather similar, it is very difficult to determine simultaneously rare earth elements in their mixtures. To reduce the collinearity of multicomponent spectra, different amounts of EDTA-Na2P2O7 were added to the rare earth-DBC-CPA(2-(4-chloro-2-phosphonophenylazo)-(2,6-dibromo-4- chlorophenylazo) 1,8-dihydroxy-3,6-naphthalene-difulfonic acid) color system. The flexible tolerance method which has high numerical stability and resolving power was used to improve the reliability of simultaneous spectrophotometry. The method has been applied to simultaneous spectrophotometric determination of seven components of rare earth elements(La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+) in synthetic samples with satisfactory results.

Cerium↗
PubMed1999

Identification and characterization of a novel siglec, siglec-7, expressed by human natural killer cells and monocytes.

We describe the characterization of sialic acid-binding Ig-like lectin-7 (siglec-7), a novel member of the siglec subgroup of the immunoglobulin superfamily. A full-length cDNA encoding siglec-7 was isolated from a human primary dendritic cell cDNA library. Siglec-7 is predicted to contain three extracellular immunoglobulin-like domains that comprise an N-terminal V-set domain and two C2-set domains, a transmembrane region and a cytoplasmic tail containing two tyrosine residues embodied in immunoreceptor tyrosine-based inhibition motif-like motifs. Overall, siglec-7 exhibited a high degree of sequence similarity to genes encoding CD33 (siglec-3), siglec-5, OBBP1/siglec-6, and OBBP-like protein and mapped to the same region on chromosome 19q13.3. When siglec-7 was expressed on COS or Chinese hamster ovary cells, it was able to mediate high levels of sialic acid-dependent binding to human erythrocytes and soluble sialoglycoconjugates, suggesting that it may be involved in cell-cell interactions. Among human peripheral blood leukocytes, siglec-7 was found to be present at low levels on granulocytes, intermediate levels on monocytes, and relatively high levels on a major subset of natural killer cells and a minor subset of CD8(+) T cells. Immunoprecipitation experiments indicated that siglec-7 is expressed as a monomer of approximately 65 kDa.

3T3 Cells↗
PubMed1999

Salmon gonadotropin IIbeta subunit promoter contains multiple DNA elements responsible for stimulation by gonadotropin-releasing hormone through protein kinase C-dependent and -independent pathways.

Gonadotropin-releasing hormone (GnRH) stimulates gonadotropin (GTH) production by activating GTH subunit gene transcription. In salmonid fish, the expression of the beta subunit gene of GTH II (sGTH IIbeta) is stimulated by GnRH at the final stages of reproduction. DNA elements required for the GnRH stimulation were examined by analyzing sGTH IIbeta promoter activity by transfection studies in a gonadotrope-derived cell line, alphaT3-1. A GnRH analog (GnRHa) specifically stimulated the sGTH IIbeta promoter (3358 bp) expression 3.6-fold, while phorbol myristate acid (PMA) stimulated it 6.2-9-fold. Analysis of a series of 5'-deletion mutants has revealed that a proximal region (-258 to -199) was important in GnRHa stimulation through protein kinase C (PKC)-independent signal transduction pathways, because an internal deletion mutant (delta(246 - 217)/3358) showed a significant decrease in the level of GnRHa stimulation, but showed no change in stimulation by PMA. A large upstream region (-3358 to -1260) showed an enhancing activity of the GnRHa stimulation, and a far upstream 530 bp segment in this region (-3358 to -2829) may be responsible for this activity. The present results suggest that sGTH IIbeta gene may be controlled by GnRH through multiple DNA elements including those responsive to PKC-dependent and -independent signal transduction pathways.

Animals↗
PubMed1999

Gender differences in p53 mutational status in small cell lung cancer.

Mutations in the p53 tumor suppressor gene have been demonstrated to be one of the most frequent genetic abnormalities in human cancers. Previous studies have shown that the frequency of p53 mutations is significantly higher in small cell lung cancer than in non-small cell lung cancer. However, this conclusion was based in large part on data derived from tumor cell lines and from studies with relatively small sample sizes and biased gender populations. To determine the mutational frequency in the p53 tumor suppressor gene and a potential difference in gender, we analyzed primary small cell lung cancer tumors from 65 patients (37 males and 28 females) for p53 mutations between exons 5 and 9. Mutations were found in 37 of 65 tumors (57%) within the region of p53 analyzed. Interestingly, none of the tumors from females contained more than one mutation, whereas four of the tumors from males contained more than one mutation. The most common mutation in this population was an adenosine-to-guanine transition (27%), followed by guanine-to-thymidine transversion (17%) and guanine-to-adenosine transition (12%). The gender difference in p53 mutational rate identified in this study suggests that a higher proportion of female tumors may develop through pathways not involving p53 mutations.

Adult↗