PubMed Health⌕ Search

Biomedical subjects

Ying Liu

Publications and source records attributed to Ying Liu.

At least 217 records · Page 12Linked to original sources
PubMed2005

[Effect of ginseng fruit saponins on insulin sensitivity index in high fat-fed rats].

OBJECTIVE: To observe the effect of ginseng fruit saponins (GFS) on insulin sensitivity index in high fat-fed rats. METHODS: An animal model of insulin resistance was established by injecting low dose of streptozotocin (STZ) in high fat-fed rats. Effect of GFS on insulin sensitivity was detected with glucose infusion rate (GIR) by euglycemic hyperinsulinemic clamp technique. RESULTS: The level of fasting blood glucose and insulin in untreated group increased more significantly than that in normal control group (P<0.05, P<0.01), while the index of GIR decreased significantly (P<0.01). As compared with the untreated groupìthe parameters of GFS-treated groups were improved significantly in a dosage-dependent manner (P<0.05, P<0.01). CONCLUSION: GFS can improve experimental insulin resistance in rats.

Animals↗
PubMed2005

[Experimental study of autologous skin grafting on retained denatured dermis for the treatment of partial thickness burn wound].

OBJECTIVE: To provide experimental evidence for the feasibility of repair of deep partial thickness burn wounds with autologous skin grafting on retained denatured dermis. METHODS: Deep partial thickness burn wounds 3.5 cm x 3.5 cm in size were produced on the back of SD rats. Superficial tangential excision was performed on the burn wounds on 2 - 5 postburn days with the preservation of denatured dermis. Split thickness autoskin was grafted on the wounds immediately. Tissue samples of whole layer of the skin were harvested from the grafted sites at different time points after the skin grafting, with 8 rats in each group. The morphology and the changes in the collagen fibres in the above tissue samples were observed by light microscopy (LM) and the changes in the biodynamics were determined. The normal skin from the same rat receiving skin grafting was employed as the control. RESULTS: (1) Vitreous degeneration was observed in the preserved denatured dermis. (2) The grafted skin was fused to the burn wound on the 7th day after autoskin grafting in rats. The dermal papillae and reticular layer could be discernible under LM. The thickness, structure and morphology of the skin on the grafted area were similar to normal tissue on the 21st day after grafting with atrophic hair follicles. The density of collagen fiber cord increased gradually, and almost fused at last. (3) The tensile strength, and maximum strain value of the rat skin after operation increased gradually, approaching normal on 60 post-operational day. CONCLUSION: The denatured dermis can recover gradually with normal structure and morphology after the application of autoskin on it for the repair of deep partial thickness burn wounds.

Animals↗
PubMed2005

[Cephalometric evaluation of the effects of pendulum appliance on various vertical growth patterns].

OBJECTIVE: The aim of this study was to investigate the effects of the pendulum appliance in treating dental Class II patients with various vertical growth patterns. METHODS: The samples (n = 30) were divided into three groups equally based on their FMA. Pretreatment and post-treatment cephalometric radiographs were taken to measure the changes. RESULTS: The amount of upper molar distalization in the low-angle group was the fewest, and that in the high-angle group was the most. Upper molars had been intruded insignificantly. The amount of anchorage loss at the first premolars and overjet increased at incisors was different in the three groups. The biggest change happened in the low-angle group, and the smallest in the high-angle group. CONCLUSION: The results of this study showed that pendulum appliance could move the upper molars distally in a short period of time. The upper molars in different groups were intruded insignificantly. Pendulum appliance could be used to move the upper molars distally in high-angle cases.

Adolescent↗
PubMed2005

[Role of NF-kappaB in the induction of delayed preconditioning in rat heart by pretreatment with Sini decoction].

OBJECTIVE: The present study was designed to investigate whether Sini decoction (SND) containing several chinese medicinal herbs, could induce delayed preconditioning-like effect in rat heart and the possible mechanism. METHOD: In anesthetized open-chest Sprague Dawley rats, left anterior descending coronary artery (LAD) was occluded for 1 h and reperfused vided into four groups: Sham ( n = 8) group in which the surgical procedure was identical to other groups,but the LAD ligature was not ligated; I/R group (n = 8) in which the LAD of rat hearts was subjected to the index occlusion; IPC/SWOP group (n = 8) in which the LAD was occluded for three cycles of 5-minute episodes of preconditioning ischemia followed by 5-minute episodes of reperfusion 24 hours prior to the index occlusion; SND group (n = 8) in which rats were pretreated with Sini decoction (5 g x kg(-1) d(-1)) for three days, the last treatment was pretreated 24 h before the index occlusion. Myocardial infarct size, the activity of superoxide dismutase( SOD) and the content of malondialdehyde (MDA) in myocardial tissue were measured. The mRNA expression of MnSOD and Cu-ZnSOD were detected by RT-PCR. The expression of P65 subunit of NF-kappaB was determined by immunohistochemistry assay. RESULT: As compared with I/R group, myocardial infarct size and the amount of MDA in myocardial tissue were significantly decreased, the activity of SOD and the mRNA expression of MnSOD were increased, the translocation of NF-kappaB was detected and furthermore the expression of NF-kappaB was significantly elevated in SND group as well as in IPC/SWOP group. The mRNA expression of Cu-ZnSOD was lowered in I/R, SND and IPC/SWOP groups, and there was no significant difference among these groups. CONCLUSION: The results suggest that Sini decoction can induce delayed preconditioning-like effect in rat heart and the activation of NF-kappaB may play an important role in it.

Animals↗
PubMed2005

[Influence of excitation light wavelength on the fluorescence spectra of ethanol solutions].

Ethanol solution can emit visible fluorescence when induced by UV light. With emission spectral profiles similar on the whole, the peaks are red-shifted distinctly when the excitation light alters from 200 to 250 nm. And the spectral profiles of ethanol solutions with different concentrations are also red-shifted when induced by the same wavelength of excitation light. A thorough analysis of the rule of spectrum peaks that are red-shifted is carried out and discussed in theory and in experiment. Investigation on the intrinsic fluorescence spectrum of ethanol solution and its characteristics will contribute to the study of the fluorescence spectra when ethanol serves as a solute and hydrolysis catalyst. Especially, this study will also help to offer a sensitive method of the determination of ethanol.

Ethanol↗
PubMed2005

[Effect of apoptosis in human breast cancer cells and its probable mechanisms by genistein].

OBJECTIVE: To investigate the effects of genistein on human breast cancer cell MCF-7 apoptosis and its probable mechanisms. METHODS: In this study, the methods of MTT, cell apoptosis detecting in fluorescent and electronic microscope and flow cytometry, and expression of Bax and erbB-2 protein were employed. RESULTS: The results showed that genistein could significantly inhibit the growth and induce the apoptosis of MCF-7 cells. Apoptotic cells of morphology from MCF-7 cells treated by different concentrations of genistein were observed by fluorescent and electronic microscope and the frequency of apoptosis in MCF-7 cells by flow cytometry showed increasingly with concentrations of genistein increased. The expression of Bax protein in MCF-7 cells was increased and the expression of erbB-2 protein was decreased with the doses of genistein. CONCLUSION: Genistein can induce MCF-7 cells apoptosis and it may be one of the mechanisms for the inhibitory effect of genistein in human cancer cells.

Anticarcinogenic Agents↗
PubMed2005

[Effects of early treatment with metoprolol on myocardial inflammatory cytokine expression and heart function in rats with acute myocardial infarction].

OBJECTIVE: The aim of study was to explore the effects of early beta-adrenergic blockade-metoprolol treatment on myocardial inflammatory cytokine expression and heart function in rats after acute myocardial infarction (AMI). METHODS: The therapeutic effects of metoprolol on myocardial inflammation and heart function up to 4 weeks (according to the protocol of CCS-2) were studied by the rat model of AMI. Myocardial inflammation was examined by taking account of the number of lymphocytes infiltrated in the myocardium and analyzing the myocardial cytokine production including the pro-inflammatory cytokines: interleukin (IL)-1beta, 6 and tumor necrosis factor (TNF)-alpha and the anti-inflammatory cytokine: IL-10. Echocardiography was used to evaluate heart function. RESULTS: The levels of TNF-alpha, IL-1beta, IL-6 and IL-10 in AMI group were markedly elevated compared to sham rats (P < 0.01) and the cytokines principally excreted by cardiac myocytes. After 4 weeks therapy, metoprolol reduced the production of TNF-alpha and IL-1beta and increased IL-10 levels (P < 0.05) in cardiac myocytes, but had no effect on the number of lymphocytes infiltrated in myocardium. Echocardiography showed that metoprolol markedly improved left heart function (P < 0.05). CONCLUSION: Early metoprolol treatment can improve heart function and myocardial inflammatory cytokine expression after AMI. One immunopharmacologic mechanism underlying the beneficial effects of beta-adrenergic blockade may involve the attenuation of pro-inflammatory cytokines and the increase of anti-inflammatory cytokine levels in cardiac myocytes.

Adrenergic beta-Antagonists↗
PubMed2005

[Epitopes recognized by cytotoxic T lymphocytes in immunoglobulin heavy chain variable regions expressed by B-cell acute lymphoblastic leukemia].

OBJECTIVE: To clone IgHV genes from childhood B-ALL cells and identify CTL epitopes deduced from IgHV gene. METHODS: Seven IgHV gene families were respectively amplified by PCR and directly sequenced for 37 childhood B-ALL cases. Bioinformatics were applied for analyzing characteristics of sequences available and predicting HLA-A*0201 molecule-binding nonapeptides derived from IgHV. The predicted nonapeptide QLVQSGAEV was synthesized and its binding affinity to T2 cells determined. CD8+ T cells from a healthy HLA-A*0201+ donor peripheral blood were stimulated repeatedly with QLVQSGAEV-loaded antigen presenting cells. RESULTS: IgHV gene rearrangements were identified in 37 B-ALL. Forty IgHV gene sequences available preferentially utilized V(H)4-59 and V(H)4-34 gene segments. Increased frequency (15.4%) of D7-27 in B-ALL IgHV was found compared to that reported for adult PBLs (P = 0.02); 20.0% DJ(H) junctions in B-ALL lacked non-encoding nucleotides, a frequency higher than that reported for adult PBLs (P = 0.02). 17.5% B-ALL IgHV contained < 2% replacement mutations. Forty B-ALL IgHV sequences acquired 12 high HLA-A*0201-binding nonapeptides, 10 (83.0%) peptides were located in frame region (FR)1 and 3. The synthesized peptide QLVQSGAEV up-regulated HLA-A*0201 expression 1.63 fold on the surface of T2 cells. The frequency of QLVQSGAEV-specific CD8+ T cells in a healthy HLA-A*0201+ donor peripheral blood increased from 1.6% and 82.6% after two-round and 3-round stimulations, respectively. CONCLUSION: IgHV genes in childhood B-ALL are of germline characteristics. Their heavy chain framework regions contain HLA-A*0201-binding nonapeptides. These peptides are capable of inducing specific CD8+ T cells to activate and proliferate.

Adolescent↗
PubMed2005

[Induction of anti-B-cell acute lymphoblastic leukemia cytotoxic T lymphocyte response against immunoglobulin heavy chain frame-derived nonapeptide].

OBJECTIVE: To induce anti-B-cell acute lymphoblastic leukemia (B-ALL) cytotoxic T lymphocyte response against immunoglobulin heavy chain frame-derived nonapeptide. METHODS: The peptide, QLVQSGAEV, containing IgHV1 frame region 3rd-11th amino acids (IgHV1(3-11)), was synthesized. IgHV1(3-11)-T2 binding tests were performed. HLA-A * 0201-positive normal peripheral blood mononuclear cells (PBMNC) were stimulated by IgHV1(3-11)-loaded antigen presenting cells three times at weekly intervals. HLA-A * 0201/IgHV1(3-11) tetramers were used to detect the proliferation of IgHV1(3-11)-specific CD8(+) T cells in the culture. Seven IgHV gene families of B-ALL patients were respectively amplified by PCR and the PCR products were sequenced to select IgHV1 and IgHV3 family monoallelic functional rearrangements. Among them, HLA-A * 0201 positive individuals were subsequently identified. Cytotoxicity of IgHV1(3-11)-specific CD8(+) T cells against HLA-A * 0201-positive IgHV1/IgHV3 family B-ALL cells was measured by MTT assay. RESULTS: The synthesized IgHV1(3-11) up-regulated HLA-A * 0201 expression on T2 cell surface by 1.63-folds. The percentage of IgHV1(3-11)-specific CD8(+) T cells in HLA-A * 0201-positive normal PBMNC was increased from 1.64% after second stimulation to 82.57% after third stimulation. At effector: target ratio of 20:1, the killing rate of IgHV1(3-11)-specific CD8(+) T cells against IgHV1 family B-ALL cells was 18.24%, being 1.8-folds as that against IgHV3 family B-ALL cells (P = 0.01). CONCLUSION: Cytolytic T lymphocytes generated in vitro against immunoglobulin heavy chain frame-derived nonapeptides can kill B-ALL cells expressing these peptides.

Cells, Cultured↗
PubMed2005

[Analysis of chromosome karyotype of oral carcinoma-associated fibroblasts].

OBJECTIVE: The purpose of this study was to investigate whether the fundamental genetic character of oral carcinoma-associated fibroblasts changes through contrasting and analyzing the oral carcinoma-associated fibroblasts and the normal fibroblasts of oral mucosa. METHODS: The two kinds of cells were treated with colchicine and microsometic fluid, and then were expanded with cold acetic acid and formalized with methyl alcohol. The cells were observed under the oil microscope after Giemsa staining. The chromosome karyotype of the two kinds of cells was analyzed by Visus 2. 1. RESULTS: There were not obvious differences in the way of chromosome karyotype between the oral carcinoma-associated fibroblasts and the normal fibroblasts of oral mucosa. CONCLUSION: The basic genetic characteristics of the normal cells are conserved in the oral carcinoma-associated fibroblasts, which means the cells have no malignant changes.

Chromosomes↗
PubMed2005

[Prospective clinical study on serum immunity in IgG-antibodies positive patients convalescent from severe acute respiratory syndrome].

OBJECTIVE: To investigate the serum immunological characteristics in patients convalescent from severe acute respiratory syndrome (SARS). METHODS: In the 1 st, 3 rd, 6 th month after their discharge, eg. SARS-IgG, T cell subsets, blood routine, and the blood biochemistry were systemically determined in SARS convalescent patients. RESULTS: The SARS-antibodies could be used as the diagnostic evidence. During the 6 months after discharge, the titers of SARS-antibodies were high, but they lowered along with passage of time. At the first recheck, the CD4(+) lymphocyte count was lower than normal level in 55.9% of patients, the CD3(+) lymphocyte count was lower than normal level in 31.2% of patients, and the CD8(+) lymphocyte count was lower than normal level in 14.0% of patients. At the second recheck, the levels of T cell subsets recovered to normal level in the most patients. CONCLUSION: T cell subsets, and the number of leukocyte are abnormal in some patients convalescent from SARS. All the indexes examined recover to normal levels half year after discharge. Therefore, it is necessary to follow up the changes in the levels of SARS-antibodies.

Adolescent↗
PubMed2005

[Management of sinonasal inverted papilloma: endoscopic excision vs traditional procedures].

OBJECTIVE: To evaluate the effect of endoscopic resection and traditional procedure in the management of sinonasal inverted papilloma with a staging system based on endoscopic examination of the nasal cavity and computed tomography (CT) scan evaluation. METHODS: Two hundred and twenty-two patients with sinonasal inverted papilloma treated surgically were retrospectively reviewed. There were 23 cases in stage I; 119 cases in stage II; 65 cases in stage III and 15 cases in stage IV. Among these patients, 122 cases were treated endoscopically; 100 cases were treated by traditional surgical techniques, including 56 cases with lateral rhinotomy; 27 cases with intranasal approach and 15 cases with Caldwell-Luc technique. RESULTS: The inverted papilloma was removed completely and no serious complications were encountered by all four kinds of techniques used. With an average follow-up of 3. 8 years, the recurrence rate for endoscopic group was 14.8% (18/122, four patients were in group I; nine in group II; four in group III; and one patient in group IV. No recurrence was found in group III who underwent endoscopic excision combined with Caldwell-Luc procedure. The recurrence rate for lateral rhinotomy group was 33. 9% (19/56, one patients in group I; six in group II; nine in group III; three in group IV). The recurrence rate for intranasal approach group was 51.9% (14/27, two patients were in group I; ten in group II; and two in group III). The recurrence rate for Caldwell-Luc procedure group was 29.4% (5/17, all in group II and group III). Regardless of approaches, patients who had primary resection had a recurrence of 26. 8%, whereas those with secondary resection had a recurrence of 20. 9% (P = 0.39). CONCLUSIONS: The endoscopic surgical technique was proved to be a better method for treating sinonasal inverted papilloma in stage I and stage II. Better results for patients in stage III would be achieved by combining endoscopic technique with Caldwell-Luc procedure. As to patients with stage IV, radical external approaches should be considered.

Adolescent↗
PubMed2005

[Chromosomal localization and inhibitory effect on TPK activition of a human novel gene hbrp].

The purpose of present study is to determine the location of the novel gene hbrp which is related to bovine seminal plasma (BSP) proteins in the human chromosome by the FISH (fluorescent in situ hybridization) technique, and to investigate the relation of HBRP to TPK( tyrosine protein kinase)by genetic engineering. The result is that the novel gene hbrp was successfully localized on human chromosome 19q1.3; HBRP protein obviously inhibited the activity of PKC. It is concluded that the structure of BSP contained two tandemly arranged fibronectin type II(Fn2)--domains which were related to the function of binding protein BSP. Amino acid sequence of HBRP protein with four tandemly arranged Fn2-domains showed that the protein might be binding protein functionly relating to BSP protein. We have concluded that HBRP protein obviously inhibited the activity of TPK. The location of the novel gene on human chromosome 19q1.3 is very important to study the other biological functions of the protein encoded by gene hbrp.

Animals↗
PubMed2005

[Expression in Pichia pastoris, fermentation and purification of HIV-1 CN54 Gag antigen].

OBJECTIVE: To express the Gag protein of HIV-1 strain CN54 in Pichia pastoris (P.pastoris), optimize fermentation parameters and purify Gag antigen. METHODS: The Gag gene was subcloned into downstream of aox1 promoter of Pichia expression vector pPS1.0, an integrative vector which possesses an identical 5' untranslated region as the natural aox1 gene and employs both in vitro construction and in vivo selection for multi-copy integrants. The recombinant vector was introduced into P.pastoris strain GS115 by electroporation and selected with G418 for Gag gene integration. Super G418 resistant clones were selected and screened for Gag expression. The engineered P.pastoris was cultured to high cell density (>300 A600 Units/ml) in a 5L fermentor. Through methanol induction, the expression level of Gag reached 120 mg/L. Intracellularly expressed Gag was released by high-pressure homogenization and purified through Sepharose FF and DEAE Sepharose FF column chromatography, the purity of Gag reached up to 90%. RESULTS: Western-blotting suggested that purified Gag expressed in P.pastoris could react specifically with serum from HIV infected individual. CONCLUSION: Gag antigen expressed in P.pastoris has provided a good basis for the development of a new generation of HIV vaccine candidates against some Chinese prevalent strains.

Blotting, Western↗
PubMed2005

[The significance of Th1/Th2 function imbalance in patients with post-infarction cardiac insufficiency].

OBJECTIVE: To study the significance of Th1/Th2 function imbalance in patients with post-infarction cardiac insufficiency. METHODS: Forty-three MI (myocardial infarction) patients were divided into 2 groups one month after the onset according to the New York Heart Association (NYHA) classification system: group MI 1 (I, II) 25 patients and group MI 2 (III, IV) 18 patients. At the same time, the heart function was evaluated by two-dimensional echocardiography. Peripheral blood mononuclear cells (PBMCs) were collected from these patients. Cytokine-producing CD4 + T cells were quantified by 3-color flow cytometry after being stimulated with phorbol myristate acetate (PMA) and ionomycin. After being stimulated with PHA, the levels of IFN-gamma and IL-4 in culture supernatants were measured by ELISA. RESULTS: The frequencies of IFN-gamma-producing T cells were found to be significantly higher in group MI 2 (16.8%) than that in group MI 1 (13.1%). There was no significant difference on the frequencies of IL-4-producing peripheral T cells between the two groups. The IFN-gamma level and the ratios of IFN-gamma/IL-4 in group MI 2 were significantly higher than those in group MI 1, while there was no significant difference in IL-4 levels between the two groups. CONCLUSIONS: The Th-cell function was associated with heart function in post MI patients. The up-regulation of Th1 cell function was consistent with poor heart function, suggesting that Th1/Th2 cell function imbalance may participate in ventricular remodelling after MI.

Aged↗