Search PubMed⌕ Search

Biomedical subjects

F Li

Publications and source records attributed to F Li.

At least 235 records · Page 13Linked to original sources
PubMed2000

[Detection of cucumber mosaic virus subgroup II isolate from tobacco plants in Yunnan province].

One of the spherical virus(designated as CMV-YNb) was isolated form the tobacco plants in Yunnan province. SDS-PAGE showed that this virus contained one polypeptide with molecular weights of 55 kD. The polypeptide was submitted to automated Edman degradation, and found the 10 amino acid sequence of the N-terminus of 55 kD protein shares 100% identity with amino acid sequence of coat protein of CMV-Q, which is belong to CMV Subgroup II. Western blot analysis also showed that this 55 kD protein was serological related to CMV-Q. A 0.9 kb cDNA fragment was amplified by RT-PCR from the RNA template of CMV-YNb with the QCf/QCr primer pair, which was designed according to the CP gene sequence of CMV-Q. The cDNA fragment was then cloned and sequenced. The fragment comprises 865 bp (EMBL accession number: AJ242585), including a 197 bp of 5' intergenic region, 657 bp of CP gene encoding 158 amino acids and a 11 bp of 3' partial non-coding region. Comparison of the nucleotide and amino acid sequences of CMV-YNb CP gene with that of CMV strains belonging to Subgroup II, and that of CMV strains belonging to subgroup I showed 97%-98% and 96%-99%, 75%-76% and 78%-79% identities, respectively. With these data, we made a conclusion that the CMV-YNb is an isolate of CMV Subgroup II.

Amino Acid Sequence↗
PubMed2000

[Effects of soil factors on root colonization of wheat by luxAB genes-marked Pseudomonas fluorescens Xl6L2].

Colonization density of Pseudomonas fluorescens Xl6L2 marked with luxAB genes in wheat Rhizosphere in sterilized Rhizobox--Calcareous chao soil microcosms was greater than that in insterilized microcosms. The population of Pf.Xl6L2 in the Rhizosphere in the rhizobox--Yellow brown soil microcosms was larger than that in the Calcareous chao soil microcosms; As soil water content was about 50% field capacity (FC), Pf.Xl6L2 could move to the place of 8 cm of root from coated seeds in the former microcosm, but only 4 cm in the later microcosm. In the former microcosms, the number of Pf.Xl612 in the rhizosphere under 60% FC and 75% FC were greater than that under 50% FC; In the second microcosm, the dispersal distance of Pf.Xl6L2 along the root was affected significantly by the soil moisture, it could be detected as far as 8 cm of root from the coated seeds under 60% FC and 75% FC.

Genetic Markers↗
PubMed2000

[Experimental study on decoctum Agrimonia pilosa Ledeb-induced apoptosis in HL-60 cells in vitro].

In this study, MTT assay, cell morphology and flow cytometry were used to explore Agrimonia pilosa Ledeb on HL-60 cells in vitro. The data suggested that Agrimonia pilosa Ledeb had the effects of growth inhibition in HL-60 cells. After treated with decoctum Agrimonia pilosa Ledeb, cells underwent apoptosis with typical morphological feature. DNA histograms by flow cytometric analysis displayed distinct apoptotic peak.

Agrimonia↗
PubMed2000

The value of 99mTc-MIBI myocardial perfusion spect imaging in detecting coronary artery disease in patients with valvular disease before operation.

OBJECTIVE: The aim of this study was to detect coronary artery disease using 99mTc-MIBI myocardial perfusion imaging in patients with valvular disease. METHODS: Thirty patients with valvular disease confirmed by echocardiography underwent 99mTc-MIBI myocardial perfusion imaging using multiSPECT 1h after stress test (exercise, dipyridamole or dobutamine test) and were performed coronary angiography within 1 month before valvular operation. RESULTS: For 29 out of the 30 patients, the results of 99mTc-MIBI myocardial perfusion imaging were similar with those of coronary angiography, the concordance rate was 96.7% and the negative predictability was 100%. CONCLUSION: 99Tc-MIBI myocardial perfusion imaging is a reliable non-invasive method for detecting coronary artery disease in patients with valvular disease and so as to draw up suitable operation programs for them.

Coronary Angiography↗
PubMed2000

[Gastric solid emptying in diabetic rats and its respond to Chinese traditional medicine].

OBJECTIVE: To investigate the change of gastric solid emptying at different stages in diabetic rats, and the effect of Chinese traditional medicine(CTM) on gastric emptying. METHODS: 40 Wistar rats were randomly divided into three groups: CTM treated diabetic(15 rats), untreated diabetic(15 rats) and control(10 rats). Diabetes was induced by i.p. of streptozotocin(STZ), 65 mg/kg. CTM, 3.75 g/kg daily (consisting of Dan shen, Fu Ling mainly which functioned as Huo xue hua yu and Bu shen) was administrated in treated diabetic rats. Blood glucose and body weights were measured weekly. 12 and 24 weeks after induction of diabetes, gastric emptying was examined with scintigraphy for 240 min (30 min interval). A test meal (42 kJ) labeled with 99mTc-SC(2.96 x 10(5) Bq) was provided. RESULTS: (1) There were no significant differences in total gastric retention rate and T 1/2 among three groups at 12 weeks. (2) The lag phase of total stomach in DM-B was (41.56 +/- 8.39) min, shorter than in control's (67.50 +/- 9.09) min, (P < 0.05). (3) The proximal gastric retention rate of 12-week diabetes at 90 min were (38.2 +/- 6.2)% (vs control, P < 0.01), (16.0 +/- 7.9)% (vs control, P < 0.01), and (61.9 +/- 3.5)%; and of 24-week at 120 min were (21.3 +/- 6.8)% (vs control, NS), (48.5 +/- 8.2)% (vs control, P < 0.05, vs treated diabetes, P < 0.01), (28.3 +/- 6.4)% in treated, untreated and control group respectively. (4) There was negative correlation between blood glucose and gastric retention rate (r = -0.62, P < 0.05). CONCLUSION: (1) The proximal gastric solid emptying was impaired in diabetic rats, there was significantly accelerated in 12-week and slowed down in 24-week compared with control. (2) CTM could modify these impairment. (3) Hyperglycemia had positive correlation to gastric emptying in animal model, which might explain the clinic presentations of patients with diabetes in early stage.

Animals↗
PubMed2000

[Construction and expression of eukaryotic expression vector pBK-IL-1ra].

OBJECTIVE: Construction of eukaryotic vector with high expression of interleukin-1 receptor antagonist (IL-1ra) for IL-1ra gene delivery. METHODS: (1) Eukaryotic expression vector pBK-IL-1ra was constructed by recombinant DNA technique, and identified by restriction mapping enzymes, PCR, and DNA sequence analysis. (2) Expressions of the IL-1ra mRNA and IL-1ra in vitro and in vivo were detected by in situ hybridization, ELISA, and immunohistochemistry. RESULTS: (1) The correct construction of pBK-IL-1ra was identified by the method above. (2) The higher levels of IL-1ra in the supernate of COS-7 cells (24 h, (P < 0.001; 48 h, P < 0.01) and the over expression of IL-1ra mRNA (P < 0.01) and IL-1ra (P < 0.05) in the synoviocytes have been detected after 48 h of the transfection with pBK-IL-1ra. (3) The over expression of IL-1ra in muscle of the mice was detected by immunohistochemistry after 4 days of pBK-IL-1ra injection (P < 0.01) CONCLUSIONS: We have successfully constructed eukaryotic expression vector pBK-IL-1ra which could highly expressed IL-1ra in vitro and in vivo, and it offers a novel possibility in the research of IL-1ra gene therapy.

Animals↗
PubMed2000

[Gastro-pyloro-duodenal motor cooperation in patients with dyspepsia].

OBJECTIVE: To investigate the role of the midgastric transverse band(MTB) and gastro-pyloro-duodenal motility in functional dyspepsia (FD) and diabetic dyspepsia (DD). METHODS: Healthy subjects, patients with FD and DD participated in the study. Of them, 65 subjects received radionuclide gastric emptying, 48 complex ultrasonograph, and 35 gastro-pyloro-duodenal manometry. RESULTS: (1) MTB was (7.01 +/- 1.31), (3.39 +/- 0.21) cm in FD and DD, which was significantly wider than that in HS group [(2.42 +/- 0.16) cm, P < 0.01, P < 0.001]. (2) The half gastric emptying time (t 1/2) in FD and DD were prolonged, gastric remained rate at 120 min increased, the gastric emptying velocity reduced when compared with HS. (3) The gastric occlusive and non-occlusive peristaltic contractions could be clearly shown under ultrasonograph. The percentage of emptying circle > 10 seconds was reduced in FD and DD. (4) There was decreased number of migrating motor complex phase III in FD and DD, when compared with HS. CONCLUSIONS: MTB is an area with physiological function, which affects intra-gastric food distribution. Patients with FD and DD showed delayed gastric emptying associated with decreased gastric motor activity and antro-pyloro-duodenal in-cooperative function. There may be different pathogenesis in FD and DD. Further study needs to be performed.

Adult↗
PubMed2000

[Studies on spectral interferences and correction in simultaneous determination of multi-elements in sediments with ICP-AES].

Spectral interferences in the simultaneous determination of multi-elements in sediments and soil by ICP-AES were investigated and the multicomponent spectral fitting (MSF) method was used for the correction. Several factors affecting the MSF method such as the signal integration time and the spectra shift were studied. The comparison between MSF and off-peak background correction were made by analyzing national standard reference material: sediment GBW07306. The detection limit and the precision could be improved by a factor of 1.3-9.0 and 1.1-4.9 respectively and the results agreed better with those of the certified values when using MSF correction.

Aluminum↗
PubMed2000

[The preparation of nanometer silver colloid by photochemical method and its resonance scattering spectroscopic study].

The maximum resonance scattering peak of the silver colloids prepared by ultraviolet-photochemical method is at 470 nm and the maximum absorption peak is at 412.2 nm. The intensity of resonance scattering light is linear to the silver concentration in the range of 0.456-9.12 micrograms.mL-1. It is the first time that the blue silver colloid was prepared photochemically. Its maximum resonance scattering peak is at 470 nm. It has two absorption peaks at 397.4 and 623.4 nm.

Colloids↗
PubMed2000

[Study on simultaneous determination of multiplex trace elements in Chinese herbal medicine loulu by ICP-AES].

A method for the simultaneous determination of multiplex trace elements in Chinese herbal medicine Loulu by inductively coupled plasma atomic emission spectrometry(ICP-AES) has been presented. The operating condictions and the suitable internal standard elements were selected. The detection limits of the method are 0.005-1.24 micrograms.mL-1 for Fe, Mn, Cu, Ti, Cr, Ba, Sr, Zn, Al with relative standard deviations (RSD) of 1.20%-3.90% (n = 7). The recoveries of most elements are in the range of 90.1%-104.2%. The method proposed has been applied to the analysis of real samples and biological standard samples (GBW 08501) peach leaves. The determined values of trace elements in the biological standard sample were in good agreement with the certified values.

Asteraceae↗
PubMed2000

[Data processing for interferogram of ultraviolet Fourier transform spectrometer].

The method of data processing for interferogram is described in this paper. The interferogram of a mercury lamp has been measured in experiment by means of ultraviolet Fourier Transform Spectrometer in developing. The apodization function that we have chosen is four-term Blackman-Harris window function and a fitting polynomial has been used for phase correction of Fourier Transform spectra based on the least square method. The ultraviolet emission lines of high precision have been obtained by use of this method.

Electronic Data Processing↗
PubMed2000

Some vegetables (commonly consumed by humans) efficiently modulate bone metabolism.

We have hypothesized that some vegetables which are part of the regular human diet may contain modulators of bone metabolism. To mimic a typical Western diet with large proportions of refined components, rats were pair-fed a semi-purified diet to which, in the treated animals, the dried material under investigation was added. Effects are expressed as % of untreated control. Bone parameters in rats were assessed in the proximal tibia by pQCT. Bone resorption (BR) was assessed by the urinary excretion of [3H]-tetracycline from prelabeled rats. Daily administration of 1 g of onion during 4 weeks increased total bone mineral content by 17.4% (p<0.05), trabecular bone mineral density by 13.6% (p<0.05). One g of onion/day administered to male rats blunted BR by 23-/+5% (p<0.05). Daily administration of onion to ovariectomized rats inhibited BR in a dose-dependent manner. At the highest dose (1.5 g of onion) BR was inhibited by 26-/+4% (p<0.01) as compared to 24-/+3% (p<0.001) for estradiol (27microg/kg/day). An additional 13 vegetables displayed significant effects on BR at the dose of 1g/day. Interestingly, 1g/day of soy did not inhibit BR in this model. Also, skimmed milk, meat and egg (all 1 g/day) were ineffective. Thus, common vegetables consumed by humans potently modulate bone metabolism in the rat. This opens the possibility to develop the basis for a low-cost, safe and effective nutritional approach to osteoporosis.

Journal Article↗
PubMed1999

7alpha-methyl-19-nortestosterone, a synthetic androgen with high potency: structure-activity comparisons with other androgens.

CNNT. There was a good correlation between bioactivity and binding affinity to AR for the 7alpha-substituted androgens compared to T. In contrast, relative to their binding affinity to AR, the androgenic potency of DHT and 19-NT was lower compared to T. The reason for the lower in vivo androgenic activity of 19-NT is attributable to its enzymatic conversion to 5alpha-reduced-19-NT in the prostate. In the case of DHT, the lower bioactivity could be attributed to its faster metabolic clearance rate relative to T. The correlation was further investigated in vitro by co-transfection of rat ARcDNA expression plasmid and a reporter plasmid encoding the chloramphenicol acetyl transferase (CAT) gene driven by an androgen inducible promoter into CV-1 cells. All the androgens led to a dose-dependent increase in the CAT activity. MENT was found to be the most potent followed by DHT, 19-NT, T, and CNNT. The specificity of the androgenic response was confirmed by its inhibition with hydroxyflutamide, an antiandrogen. Thus, there was a good correlation between binding affinity and in vitro bioactivity in the transient transfection assay for the androgens. This suggests that the in vivo bioactivity of androgens could be influenced not only by binding affinity to receptors but also by factors such as absorption, binding to serum proteins and metabolism. However, the high potency of MENT is primarily related to its higher affinity to AR.

Androgen Antagonists↗
PubMed1999

Transcriptional analysis of human survivin gene expression.

The preservation of tissue and organ homoeostasis depends on the regulated expression of genes controlling apoptosis (programmed cell death). In this study, we have investigated the basal transcriptional requirements of the survivin gene, an IAP (inhibitor of apoptosis) prominently up-regulated in cancer. Analysis of the 5' flanking region of the human survivin gene revealed the presence of a TATA-less promoter containing a canonical CpG island of approximately 250 nt, three cell cycle dependent elements, one cell cycle homology region and numerous Sp1 sites. PCR-based analysis of human genomic DNA, digested with methylation-sensitive and -insensitive restriction enzymes, indicated that the CpG island was unmethylated in both normal and neoplastic tissues. Primer extension and S1 nuclease mapping of the human survivin gene identified two main transcription start sites at position -72 and within -57/-61 from the initiating ATG. Transfection of cervical carcinoma HeLa cells with truncated or nested survivin promoter-luciferase constructs revealed the presence of both enhancer and repressor sequences and identified a minimal promoter region within the proximal -230 nt of the human survivin gene. Unbiased mutagenesis analysis of the human survivin promoter revealed that targeting the Sp1 sequences at position -171 and -151 abolished basal transcriptional activity by approximately 63-82%. Electrophoretic mobility-shift assay with DNA oligonucleotides confirmed formation of a DNA-protein complex between the survivin Sp1 sequences and HeLa cell extracts in a reaction abolished by mutagenesis of the survivin Sp1 sites. These findings identify the basal transcriptional requirements of survivin gene expression.

Apoptosis↗