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Biomedical subjects

Yan Li

Publications and source records attributed to Yan Li.

At least 523 records · Page 29Linked to original sources
PubMed2004

[Expression of orexin A, orexin receptor-1, and Ob-R of hypothalamus in rats with chronic renal failure].

OBJECTIVE: To examine the changes of expressions of orexin A, orexin receptor-1 (OX1R), prepro-orexin (Prepro-OX) mRNA, OX1R mRNA and ob-R of hypothalamus in rats with chronic renal failure (CRF). METHODS: Sixty-two male Wister rats weighing 200-250 g were divided into three groups, including group 1 (normal, n = 5), group 2 (sham-operated, n = 25) and group 3 (CRF, n = 32). Hypothalamus orexin A was assayed by radioimmunoassay. Serum leptin was assayed by enzyme linked immunosorbent assay. The expression of Prepro-OX mRNA and OX1R mRNA of hypothalamus were measured by reverse transcription polymerase chain reaction, and expression of orexin A, OX1R and ob-R by immunohistochemistry. Automatic biochemical analyzer was used to measure the serum creatinine. RESULTS: Hypothalamus orexin A levels were negatively correlated (r = -0.63, P < 0.001) with serum leptin levels in the rats. The expression of hypothalamus Prepro-OX mRNA in CRF rats was significantly lower than that of sham-operation at week 12 (P < 0.01). Hypothalamus Prepro-OX mRNA levels were negatively correlated (r = -0.81, P < 0.001) with the levels of serum leptin and serum creatinine (r = -0.68, P < 0.05) in the rats at week 12. The expression of hypothalamus OX1R mRNA in CRF rats was lower than that of sham-operation at week 12 (P > 0.05). Specific immunoreactivity for orexin A was present in perikeryon of the hypothalamus neuron. Specific OX1R-like immunoreactivity was observed in some nerve fibres. Specific immunoreactivity for ob-R was present in membranes of the hypothalamus neuron. Hypothalamus neurons of orexin A-like specific immunoreactivity in CRF rats were significantly fewer than those in shamoperated rats at week 8. Hypothalamus neurons of OX1R-like specific immunoreactivity in CRF rats were similar to those in sham-operated rat at week 8. Hypothalamus neurons of ob-R-like specific immunoreactivity in CRF rats were significantly more than those in sham-operated rats at week 8. CONCLUSIONS: The lower hypothalamus orexin A levels may be induced by high serum leptin level in CRF rats. The lower expression of hypothalamus Prepro-OX mRNA in CRF rats may be one of the main causes inducing lower hypothalamus orexin A. The expression of OX1R in hypothalamus neurons is somewhat reduced and the expression of ob-R in hypothalamus neurons is somewhat raised in CRF rats. These remain to be studied further.

Animals↗
PubMed2004

[Primary studies on synthesis and properties of mitoxantrone-insulin conjugates].

OBJECTIVE: Mitoxantrone-insulin conjugate was prepared through covalent bond, where mitoxantrone was an anticancer model drug and insulin acted as a vector. Its stability in vitro was discussed. METHODS: Spacer was used to join insulin and mitoxantrone. The intermediate and the final conjugate were characterized by infra-red spectroscopy (IR), 1H NMR, mass spectrometray (MS) and ultra-violet spectrophotometry (UV). Stability trials of the conjugate were carried out in different pH buffer solutions and mouse plasma at 37 degrees C. RESULTS: Drug loading of the conjugate was 11.68%. The conjugate was stable in phosphate buffer solution of pH 2-8 and mouse plasma at 37 degrees C. CONCLUSION: Stable mitoxantrone-insulin conjugate was obtained to ensure further tumor targeted study in vivo.

Antimetabolites, Antineoplastic↗
PubMed2004

[Study on the syndrome-effect relationship of treatment for post-craniotomy fever treated by combination of naoreqing oral liquid and western medicine].

OBJECTIVE: To observe the antifebrile effect of Naoreqing oral liquid (NRQ) in treating post-craniotomic fever, its relationship with the Syndrome type of fever, and the effect of treatment in improving main symptoms. METHODS: Patients were randomly divided, according to the ward they accommodated, into three groups, the 86 patients in the TCM group treated with NRQ, the 276 in the TCM-WM group with NRQ plus western medicine (WM) and the 89 in the WM group with WM alone. The antifebrile effect of treatment and the degree of body temperature subsidence in groups were compared, relationship between TCM Syndrome type and antifebrile effect was analyzed and the changes of scores of main symptoms before and after treatment were observed. RESULTS: The degree of body temperature subsidence and the total antifebrile effective rate in the TCM and the TCM-WM group were similar and better than those in the WM group (P < 0.01). In the TCM-WM group, the antifebrile effects in patients with various Syndrome types, in high to low order, were Dampness-Heat type > Inner-Heat type > Phlegm-Heat type, and the treatment showed definite antifebrile effect in improving main symptoms of patients of various types. CONCLUSION: Combination of NRQ and WM has definite antifebrile effect in treating post-craniotomic fever, in a Syndrome-effect dependent manner. At the same time, it also could markedly relieve the various symptoms in patients.

Analgesics, Non-Narcotic↗
PubMed2004

[A baseline survey on the association of smoking onset and life events on adolescents in Wuhan, China].

OBJECTIVE: To understand the association between stressful life event and onset of smoking among adolescents in China. METHODS: Data on baseline survey from a 5-year longitudinal smoking prevention trail was used. Five thousand, five hundred and thirty-six students, from grade 7, 8 and 9 in 22 junior high schools all over Wuhan, China, had completed the survey on the onset of smoking in the past year and on stressful life events. Logistic regression analysis was used. RESULTS: The results showed that 8.2% of the respondents reported the onset of smoking in the past year before the survey. The rates for male and female were 13.6% and 3.4% respectively while 7.8% for 7th graders, 9.1% for 8th graders and 8.3% for 9th graders. When gender, urbanicity and age were controlled with logistic regression model, the onset of smoking in general was significantly positively associated with the negative life events at school and family while negatively associated with positive life events in school and personal domain (P < 0.05). CONCLUSION: Attention should be paid to help adolescents to cope with stressful life events in order to prevent and control the onset of smoking among adolescents.

Adolescent↗
PubMed2004

[A cumulative renal survival analysis of 495 cases of IgA nephropathy].

OBJECTIVE: To study the long-term outcome of idiopathic IgA nephropathy and analyze its clinical and histological prognostic factors. METHODS: We conducted a retrospective analysis of 495 cases of IgA nephropathy patients in our hospital from 1986 to 2002. Renal survival was analyzed by Kaplan-Meier method, univariate analysis and multivariate Cox regression analysis. RESULTS: The cumulative renal survival rate was 85% at 10 years and 70.9% at 15 years. Univariate analysis found the following parameters at the time of biopsy to be significantly correlated with poor renal survival: serum creatinine > or = 133 micromol/L (P < 0.001), hypertension (P < 0.05), 24-hour urine protein excretion > or = 3 g (P < 0.001), histological subclass V (P < 0.001), and without the history of gross hematuria (P < 0.05). The Cox regression analysis showed that only the presence of hypertension (HR=7.75, 95%CI 1.02 to approximately 2.19) and serum creatinine level (HR=1.49, 95%CI 1.54 to approximately 38.90) were independent prognostic indicators. CONCLUSIONS: The findings in Chinese IgA nephropathy patients are in agreement with the results of many other studies worldwide.

Adolescent↗
PubMed2004

[Induction of apoptosis of cultured hepatocarcinoma cell by essential oil of Artemisia Annul L].

OBJECTIVE: To know whether the essential oil of Artemisia annul L. can induce apoptosis of cultured hepatocarcinoma cell SMMC-7721. METHODS: Hepatocarcinoma cells were treated by the essential oil of Artemisia annul L. while positive control was treated by hydroxycamptothecine (HPT) and negative or mock control was treated by normal saline (NS). Induction of the apoptosis was analyzed by using flow cytometry (FCM), light microscope and electronic microscope, Giemsa's stain and DNA pattern after drug treatment. RESULTS: After the treatment of the cells with 100 micrograms/ml essential oil of Artemisia annul L. for 24 hours, the morphological changes of classic apoptosis such as condensation of cytoplasm, fragmentation of nuclear chromatin, and apoptosis body were seen. The sub-G1 peak was exhibited by FCM, and the DNA ladder pattern was observed. CONCLUSION: These findings demonstrated that the essential oil of Artemisia annul L. could induce apoptosis of cultured SMMC-7721.

Antineoplastic Agents, Phytogenic↗
PubMed2004

[The cloning, expression, purification and identification of SARS virus S2 gene and study on its immunological characteristics].

AIM: To express S2 protein of SARS virus fused with Trx and then detect its reactivity to the sera from convalescent SARS patients. METHODS: The Trx-S2 fusion protein was expressed in E.coli. After purification, the Trx-S2 fusion protein was detected by Western blot with 6 serum samples of convalescent SARS patients and 6 serum samples of healthy donors. RESULTS: According to the SDS-PAGE analysis, the relative molecular mass (M(r)) of the Trx-S2 fusion protein is about 76 x 10(3). The fusion protein could react with all the sera from convalescent SARS patients but not with the sera from healthy donors. CONCLUSION: The Trx-S2 fusion protein provides a basis for the research on its role in the course of SARS virus infection of host cells and preparation of recombinant vaccine against SARS virus.

Antibodies, Viral↗
PubMed2004

[Cloning and expression of the extracellular domain of calcium-activated chloride channel in mouse airway goblet cells].

AIM: To clone and express the extracellular domain of murine calcium-activated chloride channel (mCLCA3) in airway goblet cell of mouse. METHODS: According to the gene sequence of mCLCA3 the PCR primers for N-terminal, middle and C-terminal extracellular domains were designed. Using recombinant plasmid pcDNA3.1(-)/mCLCA3 as template, the DNAs coding for the three extracellular domains were amplified. And then the DNAs encoding N-terminal and C-terminal extracellular domains were inserted into expression vector pRSET-A, while the middle extracellular domain DNA was inserted into pGEX-T1. E.coli. BL21(DE3) were transformed with the three recombinant plasmids, respectively, and were induced with IPTG for expression. RESULTS: DNA sequencing showed that the cloned DNAs encoding extracellular domains were identical with those in GenBank (GenBank accession No. NM-017474 ). The 3 domains were expressed in E.coli and most of the expressed products existed in the form of inclusion body. CONCLUSION: The expression of three extracellular domains of mCLCA3 lays the foundation for further preparing anti-mCLCA3 antibody and exploring the mechanism of modulation of mCLCA3.

Animals↗
PubMed2004

[Study on the relationship between serum cytokeratin 19 level in hepatocellular carcinoma patients and the clinico-pathologic characteristics].

OBJECTIVE: As our previous comparative proteomics study on high and low metastasis human hepatocellular carcinoma (HCC) cell strains revealed that cytokeratin 19 (CK19) was related to higher metastasis potential, we further investigated the relationship between serum CK19 level in HCC patients and their clinico-pathologic characteristics. METHODS: Serum CK19 levels of 101 normal controls and 108 pathology-proven HCC patients were determined using radioimmunoassay, and the their correlation with clinico-pathologic parameters were studied. RESULTS: The upper limit of one-side 98% confidence interval of normal serum CK19 level was 2.3 microg/L. Among 108 HCC patients, 24 (22.2%) had increased serum CK19 level, ranging from 2.4 to 45.5 microg/L. There were 12 patients (11.1%) with increased CK19 level but normal AFP level. The percentage of poor differentiated tumor was higher in CK19 increased cases (37.5%, 9/24) than in CK19 normal cases (20.2%, 17/84). Moreover, the presence of portal vein tumor emboli was significantly higher in CK19 increased cases (25.0%, 6/24) than in CK19 normal cases (6.0%, 5/84). (Chi-square = 7.403, P < 0.01) In addition, the percentage of TNM stage III/IV tumor was significantly higher in CK19 increased patients (54.2%, 13/24) than in CK19 normal cases. (chi-square = 13.300, P < 0.005) CONCLUSION: Some HCC patients do have increased serum CK19 level, which could be related to portal vein tumor emboli, poor tumor differentiation and advanced tumor stages.

Adult↗
PubMed2004

[Application of ricin-immunotoxin mediated T cell depletion to allogeneic hematopoietic stem cell transplantation].

This study was aimed to investigate the clinical outcome of ricin-immunotoxin mediated T cell partially depleted HLA/MLC mismatched allogeneic hematopoietic stem cell transplantation. 13 patients with hematological malignancies were treated by ricin-immunotoxin mediated T cell partially depleted allogeneic hematopoietic stem cell transplantations from HLA/MLC mismatched donors, including 6 cases of CML in CP(1), 1 case of ALL in CR(1), 1 case of ALL in CR(2), 1 case of ALL in relapse, 2 cases of AML in CR(1), 1 case of AML in CR(2), 1 case of MDS-RAEBT-AML (M(4)) in CR(1). The results showed that 8 cases were engrafted successfully, 2 cases of them developed grade II acute GVHD and 2 cases developed grade III-IV acute GVHD. Within following-up of 8 - 90 months, 2 patients who experienced grade III-IV acute GVHD died early after transplantation; 1 patient died of late onset of infection; the other 5 patients survived free from diseases. After failure at first infusion, 4 patients were given reinfusion of peripheral blood hematopoietic stem cells from the same donor. 3 out of 4 cases failed to engraft and only one patient got engraftment but died of related complications of transplantation. One patient was performed a second transplantation from a syngeneic donor and survive free of disease until now. In conclusion, T cell partially depleted HLA/MLC mismatched allogeneic hematopoietic stem cell transplantation by ricin-immunotoxin decreases the occurrence of severe acute GVHD but with high risk of rejection, which clinical outcome still needs further evaluation.

Adolescent↗
PubMed2004

[A retrospective analysis on multiple cord blood transplantation in 13 cases].

In order to study the feasibility of multi-umbilical cord blood transplantation (multi-UCBT) in adult, 13 cases of unrelated allogeneic multi-UCBT performed from June 1998 to July 2003 were analyzed retrospectively. All cord blood units were obtained from full term normal vaginal and cesarean deliveries in Guangzhou Maternity and Neonatal Hospital. The fractionation, cryopreservation and thawing of cord blood were done according to the regulation of New York Umbilical Cord Blood Bank and pertinent literatures. Donors of HLA 1/6-2/6 mismatch were accepted at registry search. The results showed that from June 1998 to July 2003, 28 umbilical cord blood units were selected by 7 transplantation centers for 13 cases. The median age of recipients was 22 (8 - 41) years, and the median weight was 50 (21 - 75) kg, the median infused dose of total nuclear cells was 2.91 x 10(7)/kg. Six out of thirteen cases were engrafted after cord blood infusion with absolute neutrophil count of > 5.0 x 10(8)/L at 19 days post-infusion. Only one case suffered from graft versus host disease, the total survival of multi-UCBT was 46.2% (6/13). It is concluded that good prospects in the field of multi-umbilical cord blood transplantation is likely to be realized.

Adolescent↗
PubMed2004

A simple and rapid method for propagation and purification of the peripheral blood gammadeltaT cells.

The purpose of this study was to set up an approach for expansion of the peripheral blood gammadeltaT cells from normal subjects in order to explore the characteristics of gammadeltaT cells. Peripheral blood mononuclear cells (PBMNC) were separated from 5 - 10 ml peripheral blood and stimulated by the low molecular peptide derived from Mycobacterium tuberculosis (MTb-Ag), and expanded in rIL-2-containing medium. The relative amount of gammadeltaT cells were measured by anti TCR gammadelta-PE staining and flow cytometry. The Cytotoxicity were detected by gammadeltaT assay. The results showed that after stimulation and expansion for 10 days, gammadeltaT cells increased to 69.2% of the total PBMNC and demonstrated significant cytotoxicity against K562 cells. In conclusion, this is a simple, rapid and specific method for expansion of peripheral blood gammadeltaT cells in vitro.

Antigens, Bacterial↗
PubMed2004

[The distribution of gene polymorphisms in the intron 2 and exon 2 of interleukin-1 receptor antagonist and their correlation with the serum lipoprotein level].

OBJECTIVE: To study the distribution of variable numbers of tandem repeat (VNTR) polymorphism in the intron 2 and the single nucleotide polymorphism (SNP) at position +8006 in the exon 2 of IL-1RN in healthy Chinese Han Population of Wuhan province and to analyze their correlation with the serum lipoprotein level. METHODS: IL-1RN (VNTR) and IL-1RN (+8006) polymorphisms were detected by PCR and PCR-RFLP methods in 251 healthy Chinese Han Population of Wuhan, and the levels of serum lipoprotein, IL-1 and IL-1Ra were inspected simultaneously. RESULTS: In IL-1RN (VNTR), allele I appeared most common, then allele II, and allele IV was rare. At the position of IL-1RN (+8006), allele T was most commonly seen followed by allele C. Allele II of IL-1RN (VNTR) always existed with allele C of IL-1RN (+8006). The levels of serum lipoprotein, IL-1 and IL-1Ra were not different among the different genotypes of the two polymorphisms. CONCLUSION: There were two gene polymorphisms in the intron 2 and exon 2 of IL-1RN, which were not correlated with the levels of serum lipoprotein, IL-1 and IL-1Ra. However, there seemed to be a linkage disequilibrium between IL-1RN (VNTR) and IL-1RN (+8006).

Adolescent↗
PubMed2004

[Effect of BMP-7 on the transdifferentiation of cultured human tubular epithelial cell induced by TGF-beta1].

OBJECTIVE: To observe the effect of bone morphogenetic protein-7 (BMP-7) on the transdifferentiation of cultured human tubular epithelial cell (HKC) induced by TGF-beta1 and to elucidate its possible mechanism. METHODS: The cultured HKC cells were divided into 5 groups: serum-free group (negative control); single TGF-beta1 treated group (positive control); single BMP-7 treated group; combined TGF-beta1 and BMP-7 treated group; and BMP-7 pre-treated group. Expression of keratin of HKC cells was assessed by indirect enzyme immunohistochemistry (IEI), expression of alpha-smooth muscle actin (alpha-SMA) and E-cadherin by immunohistological method, percentage of alpha-SMA positive HKC cells by flow cytometry, and mRNA expression of alpha-SMA, TGF-beta1, and TGF-beta type II receptor by reverse transcription PCR. RESULTS: The expression of alpha-SMA and the percentage of alpha-SMA positive HKC cells markedly increased after having been treated by TGF-beta1 while the expression of E-cadherin and keratin decreased. In the group pre-treated with BMP-7 (50 ng/ml) and then added with TGF-beta1 (8 ng/ml), expression of alpha-SMA was significantly lower than in the positive control group, while expression of E-cadherin and keratin significantly higher than in the positive control group. Measurement of the percentage of alpha-SMA positive HKC found significant deference between the combined TGF-beta1 and BMP-7 treated group and the positive control group (9.7% vs 19.8%; 5.8% vs 19.8%; P < 0.05). Significant difference existed between the BMP-7 (50 ng/ml) pre-treated group and the positive control group (8.7% vs 19.8%, P < 0.05). mRNA expression of alpha-SMA was measured by RT-PCR and the results showed that it significantly decreased in the group treated or pre-treated with BMP-7 (50 ng/ml) (15% and 12% of the results in the positive control group, respectively). The mRNA expression levels of both TGF-beta1 and its type II receptor significantly decreased (28% and 19%; 47% and 36%, compared with the positive control group, respectively). CONCLUSION: Transdifferentiation of cultured renal epithelial cell induced by TGF-beta1 can be inhibittd by certain levels of BMP-7, cultured together with TGF-beta1 or pretreated. BMP-7 can prevent and inhibit the mRNA expression of TGF-beta1 and its type II receptor, which may be an important mechanism by which BMP-7 inhibit the transdifferentiation of renal tubular epithelial cell.

Actins↗
PubMed2004

[Expression of antibody Fab against platelet IIb/IIIa in E.coli and characterization of its biological activity].

AIM: To develop a Fab antibody against platelet GPIIb/IIIa. METHODS: A mouse anti-human GPIIb/IIIa monoclonal antibody (mAb) P140 was selected by the indirect immunofluorescence assay (IFA) and platelet aggregation inhibition test. The Fd and light chain genes were cloned from the hybridoma cells secreting the mAb P140. The genes of P140 Fab were inserted into plasmid p3MH to construct recombinant expression plasmid p3MH/P140kappa-Fd. After digestion with the restriction enzyme, the recombinant plasmid was transformed into E.coli XLI-Blue. The expressed product was purified by TALON metal affinity resin. Purified P140 Fab was characterized by SDS-PAGE, ELISA, Western blot and platelet aggregation inhibition test. RESULTS: SDS-PAGE analysis showed that relative molecular mass (M(r)) of P140 Fab was 47x10(3). The results of ELISA, Western blot and platelet aggragation inhibition test indicated that P140 Fab could specifically bind to platelet and inhibit platelet aggragation in dose-dependent manner. The mean value of IC(50) was 16.85 mg/L. CONCLUSION: A soluble anti-platelet GPIIb/IIIa antibody P140 Fab was prepared successfully, which lays the foundation for further clinical application.

Amino Acid Sequence↗
PubMed2004

[Role of intron and 5' untranslated region in human thrombopoietin gene expression].

OBJECTIVE: To study the role of 5' untranslated region (UTR) and intron in the expression of human thrombopoietin (TPO) gene. METHODS: A number of expression vectors containing TPO mini-gene fused to the regulatory elements of cytomegalovirus (CMV) were constructed and transfected via lipofectin into cultured cos-1 cells for transient expression of TPO gene. The cell culture media were analyzed with highly sensitive sandwich enzyme-linked immunosorbent assay (ELISA) 48 h after the transfection. RESULTS: The expression levels of the TPO gene elements followed the order of TPO intron v> TPOcDNA> TPO intron I> TPO intron I> TPO gDNA in cos-1 cells. CONCLUSION: The last intron of TPO gene obviously enhances the expression level of TPO gene, which can be inhibited by 5'UTR of TPO gene.

5' Untranslated Regions↗
PubMed2004

Genetic analysis of rice varietal diversity for rice blast control.

Two Indica hybrid rice of Shanyou63 (A) and Shanyou22 (B), two glutinous landraces of Huanghenuo (C) and Zinuo (D) and three improved Japonica rice of Hexi41 (E), Chujing12 (F) and 8126 (G) were selected and their genetic resistance relationship was estimated using resistance gene analogue (RGA). The results showed that there were similar genetic relationships between hybrid varieties at the genetic similarity (GS) of 0.86,and among improved Japonica varieties at the GS of 0.84, while highly genetic diversifications between traditional varieties, Indica and Japonica varieties, traditional and modern variety ( GS:0.45). The results also showed that clustering analysis based on RGA data were generally corresponded to known pedigrees and blast field resistances of the varieties. Based on varietal differences in RGA data and agronomic traits, plot experiments of five mixed-planting combinations of A/C, A/D, B/C, B/D and A/B and two combinations of E/C and E/F/G were conducted in Jianshui and Shiping counties ( Indica rice growing region) and Luxi County (warm Japonica region) in Yunnan Province in past two years, respectively. The results demonstrated that rice blast management was more effective in five mixed-planting combinations of varieties with different genetic backgrounds (GS: 0.45-0.77) than in two combinations with similar genetic relationships (GS: 0.84-0.90), compared with their monocultures. It is evident for the highly susceptible landraces in mixed-planting to achieve disease control, with significant decreases both in incidence and severity. The blast control efficiencies of landraces in different mixture combinations reached to 54.47%-92.18%. The control efficiencies of improved varieties varied from 15.12% to 25.54% in mixture combinations with closed genetic relationship. In addition,the total yield of 5 varietal combinations with distant genetic relationship increased 539.0-904.0 kg/ha in the mixed-planting plots, at increase rates of 5.6%-10.2%. Mixed rice varieties with similar genetic background did not achieve significant yield increase. Otherwise, the yield of E/F/G decreased 2.7%-4.0% compared with pure stand. The results can provide scientific basis of varietal combinations in diversification experiments for blast control.

Genetic Variation↗