Biomedical subjects

Li Zhou

Publications and source records attributed to Li Zhou.

At least 73 records · Page 4Linked to original sources

PubMed2005

Determination of nine organophosphorus pesticides in cereals and kidney beans by capillary gas chromatography with flame photometric detection.

A method is developed for the determination of nine organophosphorus pesticide residues in cereals and kidney beans by capillary gas chromatography with flame-photometric detection. In this method, dichloromethane is used for clean-up after liquid-liquid extraction. It is shown that good separations are obtained using a fused-silica capillary column (DB-1701) by the optimized temperature program. In the spiked levels of 0.012-0.43 mg/kg, the recoveries are from 83.7% to 107%, with the relative standard deviation between 3.2% and 13% and limits of detection from 8.2 to 15 microg/kg. The method is rapid, sensitive, and practical.

Chromatography, Gas↗

PubMed2005

Similar effects on rat renal mesangial cells by expressing different fragments of adrenomedullin gene in vitro.

AIM: To construct pEGFP-N3 recombinant vectors carrying adrenomedullin (AM) or fragments of the AM gene, and to express AM or fragments of AM from the pEGFP-N3 recombinant vectors (pEGFP-N3-AM1-2 and pEGFP-N3-AM1-3) and study their biological properties on cultured rat renal mesangial cells (RMC). METHODS: Total RNA of rat kidney was obtained using TriZol reagent. The cDNA was synthesized by reverse transcriptase using oligo-deoxythymidine as primer. The fragments of AM gene were then amplified by polymerase chain reaction (PCR) with specific upstream and downstream oligonucleotides. The PCR products were digested with EcoRI and BamHI and subcloned into the plasmid pEGFP-N3. Facilitated by cationic liposomes, RMC were transfected with pEGFP-N3-AM1-2 or pEGFP-N3-AM1-3. After 24 h, green fluorescent protein (GFP) fluorescent images were examined with a fluorescence microscope. After 48 h, the proliferation of RMC was detected using the MTT assay, and the mRNA expression of transforming growth factor-beta1 (TGF-beta1) was measured by semiquantitative PCR. RESULTS: DNA sequence reports verified that pEGFP-N3-AM1-2, which carried the full length AM gene translation fragment (preproadrenomedullin preproAM1-185), and pEGFP-N3-AM1-3, which carried the translation fragment of preproAM [without adrenotensin (ADT, preproAM150-185)], were constructed successfully. After 24 h, green fluorescence was observed in RMC into which either pEGFP-N3-AM1-2 or pEGFP-N3-AM1-3 was transfected, while in the control cells no fluorescence was observed. Either pEGFP-N3-AM1-2 or pEGFP-N3-AM1-3 delivery inhibited the proliferation of RMC (P<0.01) and decreased the mRNA transcription level of TGF-beta1 in RMC (P<0.05). However, no significant difference was observed between the effects of pEGFP-N3-AM1-2 and pEGFP-N3-AM1-3. CONCLUSION: pEGFP-N3-AM1-2 and pEGFP-N3-AM1-3 were constructed successfully and were functionally expressed in RMC. Expressing the fragment of AM without ADT has similar inhibitory biological effects on RMS proliferation and TGF-beta1 transcription with full length preproAM.

Adrenomedullin↗

PubMed2005

[Effect of Fränkel function regulator on the condylar and mandibular positions of patients with class II malocclusion].

OBJECTIVE: To determine the positional changes of condyle and mandible in children treated successfully with Fränkel function regulator. METHODS: 30 Angle's class II patients including 15 boys and 15 girls treated with Fränkel function regulator were selected. Superimposition of the pretreatment and posttreatment lateral cephalograms of all the patients was done on the stable bone structure of the anterior cranial base and mandible. Cartesian coordinate system was used to measure the positional changes of condyle and mandible over time by computer. RESULTS: There was significant inferior displacement of condyle, gonion and pogonion after treatment with reference to stable bone structure of anterior cranial base. Anterior displacement of pogonion in boys was also significant. There was significantly superior and posterior displacement of condyle and posterior displacement of gonion after treatment with reference to stable bone structure of mandible. CONCLUSION: Fränkel function regulator can stimulate condylar growth and do favor to mandibular remolding.

Activator Appliances↗

PubMed2005

[Clone expression and purification of influenza A virus nucleoprotein gene].

OBJECTIVE: To clone the influenza A virus NP gene into expression vector and to purify the target protein, which was used to study the preparation of monoclonal antibody. METHODS: The RNA of influenza A virus was extracted and primers were designed according the NP gene sequence, then the NP gene of influenza A virus was expressed in E.coli DH5alpha and the NP protein was purified by affinity chromatography. RESULTS: The recombinant expression vector-pGEX-4T-2-NP was successfully constructed and relatively pure target protein was obtained. CONCLUSION: Through reasonably controlling the fermentation time, growth temperature and induction concentration, satisfactory soluble target product was obtained.

Base Sequence↗

PubMed2005

Effect of oxidized-LDL on NF-kappaB nuclear translocation in aortic smooth muscle cells originated from rats of different ages.

OBJECTIVE: To investigate the molecular mechanism of atherosclerosis that related to age. METHODS: Immunohistochemistry staining and Western blot were adopted to determine the nuclear translocation of nuclear factor-kappa B (NF-kappaB) and expression of platelet-derived growth factor B (PDGF-B) in smooth muscle cells (SMCs) co-cultured with low density lipoprotein (LDL), oxidized LDL (ox-LDL), and ox-LDL+high density lipoprotein (HDL) originated from rats of 2 and 10 months old respectively. Fat stain was used to identify the lipid intake in SMCs. RESULTS: The optimal stimulation time of ox-LDL to SMCs was 12 hours. NF-kappaB intensity increased in most nuclei of SMCs that originated from rats of either 2 or 10 months old co-cultured with ox-LDL. The intensity of NF-KB and the amount of intracellular lipid taken in SMCs were more obvious in cells from 10-month-old rats than from the younger ones. Change of PDGF-B expression in SMCs was not remarkable in each group of rats. CONCLUSIONS: The 10-month-old rats are more susceptive to ox-LDL than 2-month-old rats in activating nuclear translocation of NF-kappaB. Maybe this is one of the important reasons contributing to the difference between the older and younger rats on the initiation and development of atherosclerosis lesion. Expression of PDGF-B is not associated with the activity of nuclear translocation of NF-kappaB.

Age Factors↗

PubMed2005

[Effects of RGD tripeptide on the expression of FAK and HA in glomerular mesangial cells].

OBJECTIVE: Observing the effects of Arg-Gly-Asp (RGD) peptides on the proliferation of glomerular mesangial cells (GMCs), and on the expression of focal adheshion kinase (FAK) and hyaluronic acid (HA) in GMCs. METHODS: GMCs of rats were induced with RGD peptide in vitro. The proliferation of GMCs was measured by MTT; the expression of FAK, by immunohistochemistry; and the quantity of HA, by radioimmunoassay. RESULTS: After being incubated with RGD peptides, some of the attached GMCs became round, detached, and floated. As compared with the control, the proliferation (A value) of the induced with RGD peptide GMCs was significantly lower. After the cultured GMCs had been induced with RGD (1 mmol/L) for 24 h, the expression of FAK decreased by 3.10%, and the secretion of HA decreased by 5.64%. After the cultured GMCs had been incubated with RGD (4 mmol/L) for 8 h and 24 h, the expression of FAK decreased by 6.50% and 15.95%, and the secretion of HA decreased by 6.37% and 18.43%, respectively. CONCLUSION: RGD peptides can inhibit the attachment of the cultured GMCs, reduce the proliferation of GMCs and decrease the secretion of the extracellular matrix.

Animals↗

PubMed2005

[Sexual dysfunction in female patients with chronic renal insufficiency].

OBJECTIVE: To investigate the prevalence, the main manifestations and related factors of sexual dysfunction in female patients with chronic renal insufficiency (CRI). METHODS: A multi-factor cooperation cross-section study was conducted. The prevalence and severity of sexual dysfunction were assessed using SCASF Microsoft. RESULTS: The prevalence of sexual dysfunction in patients with CRI was higher than that in those without renal insufficiency (P<0.05). The main manifestations in female patients were "decreased libido, lack of orgasm and no feeling of sex pleasure". Stratified analysis on uremia showed that the prevalence and severity of sexual dysfunction of the patients on hemodialysis were similar to those on peritoneum dialysis. The women with kidney allografts suffered less "decreased-libido, lack of orgasm and no feeling of sex pleasure". Multivariate analyses demonstrated that anemia, depression, and the use of beta-blocker were risk factors for decreased libido. Ageing was a risk factor for "lack of orgasm". The use of r-HuEpo was inversely associated with "lack of orgasm". CONCLUSION: Sexual dysfunctions are common in female patients with CRI. The main manifestations are decreased libido, lack of orgasm and no feeling of sex pleasure. The replacement therapy, especially kidney transplantation, could decrease the prevalence or severity of sexual dysfunction. The genesis of sexual dysfunction is multifactorial, including age, physiological factors, psychological factors and medical conditions.

Adult↗

PubMed2005

[Functional analysis of novel mutations in PAX9 associated with familial oligodontia].

OBJECTIVE: To gain new insights into the molecular pathogenesis of the 109(InsG) and 139(C--> T) mutations and their roles in familial oligodontia. METHODS: The region of PAX9 paired domain (PAX9PD) was amplified and the expression plasmids were constructed in pGEXlambda -1T by PCR-based cloning. PAX9PD proteins were prepared on the basis of GST instruction. The binding of wild type and two novely mutant PAX9 paired domain to double-stranded DNA targets were analyzed by gel mobility shift assay. RESULTS: Wild type PAX9PD protein bind to the high affinity paired domain recognition sequences, CD19-2(A-ins) and Pax6CON, the 109(InsG) and 139(C--> T) mutant PAX9PD protein were unable to bind to these cognate DNA-binding sites. CONCLUSION: The functional defects in DNA binding of mutant 109(InsG) PAX9 and 139(C--> T) PAX9, as well as loss-of-function of PAX9 most likely result in its haploinsufficiency during the patterning of dentition and the subsequent loss of posterior teeth.

Anodontia↗

PubMed2005

[Calcium antagonistic effect of Xanthotoxol on isolated guinea pig atria].

OBJECTIVE: To study the mechanism of depressant effect of xanthotoxol (XT) on contractility in the isolated guinea pig atria. METHODS: The contractile force of the isolated left atria was determined by tension recording method. RESULTS: In the experiments on contractility of the left atria XT and Verapamil (Ver) significantly depressed the positive staircase phenomena, which was reversed by Ver but not by XT. However, the post-rest potentiation of myocardial contraction in the left atria was only markedly decreased by XT but not by Ver. Furthermore, XT not only attenuated the positive inotropic action, but also delayed the following toxicity response induced by ouabain in the isolated left atria. CONCLUSION: XT blocked not only the voltage dependent calcium channel, but also the receptor operated calcium channel in the isolated guinea pig atria.

Animals↗

PubMed2005

Degradation of crude oil by indigenous microorganisms supplemented with nutrients.

Different kinds of mineral nutrients(NO3-N, NH4-N and PO4-P) were applied in the simulated oil-polluted seawater for enhancing oil biodegradation in the N/P ratio 10:1 and 20:1. Although indigenous microorganisms have the ability to degrade oil, adding nutrients accelerated biodegradation rates significantly. For the group amended with NO3-N and PO4-P in the ratio 10:1, the reaction rate coefficient was 4 times higher than the natural biodegradation. Chemical and microbiological analysis showed that the optimal N/P ratio in the system is 10:1, and microorganisms tend to utilize nitrate rather than ammonium as N source.

Biodegradation, Environmental↗

PubMed2005

[K-mean cluster analysis for incisal jaw morphology of normal occlusion subjects among different vertical facial skeletal types].

OBJECTIVE: To study the incisal jaw morphology of subjects with normal occlusion and to discuss the relationship between different vertical facial skeletal types and different incisal jaw cluster types. METHODS: After studied by radiographic cephalometry, the incisal jaw morphology of 169 subjects with normal occlusion in early permanent dentition were analyzed by K-mean cluster analysis. RESULTS: Morphology of maxillary or mandibular incisal jaws could be divided into four types separately, including division I, division II, division III and division N. In maxilla or in mandible, the incisal jaw morphology of division I was characterized by wideness and shortness. In contrast, division II was characterized by thinness and length. As for division III and division IV, both of two were intermediate types between division I and division II . In maxilla, it was found that division II was the majority (86.49%) in the high-angle subjects, division III was the majority (47.67%) in the average-angle subjects, and division I and III were the majority (82.61%) in the low-angle subjects. In mandible, it was found that division II was the majority (51.35%) in the high-angle subjects, division IV was the majority (48.84%) in the average-angle subjects, and division III and IV were the majority (69.57%) in the low-angle subjects. CONCLUSION: Owing to the obvious characteristics of morphology in each cluster types and in each vertical facial skeletal types, different clinic considerations must be put forward when we want to move the incisor.

Cephalometry↗

PubMed2005

[Novel mutations of PAX9 gene in Chinese patients with oligodontia].

OBJECTIVE: To investigate the mutational characteristics of PAX9 gene in Chinese patients with congenital oligodontia and thus to provide a molecular basis for studying the pathogenesis of oligodontia. METHODS: Thirteen individuals with oligodontia and 9 healthy individuals, from 4 unrelated autosomal dominant families, and 16 sporadic patients with hypodontia in China, as well as 196 healthy control individuals (without oligodontia or hypodontia) were screened. Congenital absence of teeth was confirmed by panoramic X-ray analysis. Mutations of PAX9 gene were detected using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. After the finding of abnormal SSCP bands, analysis was carried out with DNA sequencing. RESULTS: PCR-SSCP detected SSCP bands alteration in exon2 of PAX9 gene in two unrelated families. Sequencing of PAX9 gene revealed a novel frameshift mutation (109InsG) and a novel missense mutation (C139T). All the affected members of each family were heterozygous for the mutations. In sporadic patients and the other two families, no similar sequence changes in PAX9 gene were found. CONCLUSIONS: The results extend the spectrum of mutations in PAX9 gene associated with oligodontia. The novel mutations will play an important role in gene diagnosis of oligodontia.

Adolescent↗

PubMed2005

[The point of view of moxibustion in the book, A General Survey of Moxibustion].

OBJECTIVE: To study on academic point of view of the book, A General Survey of Moribustion. METHODS: Study academic thought of the book and clarify academic origin and characteristics of the book. CONCLUSION: Processing of argyi leaf, manufacture of mugwort floss and size of moxa cone have a certain technique standards in the book. The book indicates that small cones should be used with more times of moxibustion. and the properties of mugwort floss are not dry and heat, but are warm and moist and mild, moxibustion not only can be used to treat cold syndrome but also can be used to treat heat syndrome; the body can response to the external moxibustion. The above points of view have still guiding significance in nowadays.

Acupuncture Points↗

PubMed2005

[Effect of radix bupleuri extract on cardiomyocyte apoptosis related genes expression in mouse infected with coxsackie virus B3m].

OBJECTIVE: To explore the mechanism of Radix Bupleuri (RB) extract in regulating cardiomyocyte apoptosis. Methods The BALB/c mouse inoculated with the cardiomyocytophilic strain Coxsackie virus B3m (CVB3m) by peritoneal injection was adopted as viral myocarditis model. The experimental mice were divided into the normal control (A), the model (B) and the RB (C) groups. Mice in Group C were given 0.2 ml / 10 g of RB extract, 2 mg/ml in concentration by gastrogavage once daily, while equal volume of normal saline was given by gastrogavage to mice in Group A and B. All the mice were sacrificed on the 10th day after modeling. The cardiomyocyte apoptosis was detected by TDT/Dutp nick end labelling (TUNEL). The expression of Fas Bcl-2, and Caspase3 protein in myocardium was determined by immunohistochemistry and reverse-transcription polymerse chain reaction (RT-PCR). RESULTS: The apoptotic cell was not found in Group A, but Fas, Bcl-2 and Caspase3 were expressed in different degree. In Group B, a lot of apoptotic cells could be seen, with expression of Fas, Bcl-2 and Caspase3 stronger than those in Group A (P < 0.01). Compared with Group B, the apoptotic cardiomyocyte in Group C was significantly reduced (P < 0.01), with the expression of Fas and Caspase3 significantly lowered but expression of Bcl-2 increased slightly. CONCLUSION: RB extract could inhibit the cardiomyocyte apoptosis in animal with viral myocarditis, obviously down-regulate the expression of Fas and Caspase3, and slightly up-regulate Bcl-2 expression.

Animals↗

PubMed2005

[Effect of matrine on regulating renal tubulointerstitial expression of MMP-3, TIMP-1 and FN].

OBJECTIVE: To explore the effect and mechanism of matrine on regulating renal tubulointerstitium expression of MMP-3, TIMP-1 and FN. METHODS: Seventy male SD rats were randomly allocated to five groups: normal group, shame UUO group, UUO group, UUO group treated with fusinopril (F group), UUO group treated with large dose of matrine (E group) and UUO group treated with small dose of matrine (D group). The expression levels of MMP-3, TIMP-1 and FN of the rats were determined with immunohistochemistry at 7, 14 days of the experiment. RESULTS: The expression levels of MMP-3 of the rats in the UUO group and treatment groups decreased significantly compared with the normal group and shame UUO group (P<0.05). The treatment groups had higher expression of MMP-3 than that of the UUO group (P< 0.05). The expression levels of TIMP-1 and FN of the rats in the normal group and shame UUO group were amongst the lowest. The treatment groups had lower expression of TIMP-1 and FN than that of the UUO group (P<0.05). No significant difference of expression of MMP-3, FN and TIMP-1 were found between E group and F group (P>0.05). The expression level of MMP-3 was negatively correlated with those of TIMP-1 and FN in the UUO group (P < 0.01). CONCLUSION: Matrine decreases the expression of TIMP-1 and FN in the tubulointerstitium and increases the expression of MMP-3, which would delay the progression of renal tubulointerstitial fibrosis.

Alkaloids↗

PubMed2005

[Gene transfer of tumor necrosis factor related apoptosis inducing ligand to endothelial progenitor cell for ovarian cancer therapy].

OBJECTIVE: To express tumor necrosis factor related apoptosis inducing ligand (TRAIL) protein using endothelial progenitor cell (EPC) and observe antitumor activity of secreted TRAIL in cell culture supernatant. METHODS: EPC were isolated by immunomagnetic sorting. Human TRAIL plasmid was transfected into EPC by lipofectamine 2000. The cell culture supernatant was harvested and the secreted protein was measured by immunoassay method. Apoptosis rate was analysed by flow cytometry. RESULTS: EPC could develop from the culture of cord blood CD(133)(+) (cluster of differentiation 133(+)) cells. EPC may be transiently transfected with human TRAIL plasmid. The level of TRAIL in the cell culture supernatant was higher in the TRAIL transfected group than in the non-transfected group and green-fluoro protein (GFP) transfected group (532.8 pg/ml versus 12.4 and 9.2 pg/ml). Apoptosis detection showed that TRAIL had high antitumor activity in 3AO cell, the apoptosis rate of ovarian cancer cell could reach 24.1%. CONCLUSIONS: In vitro, TRAIL EPC gene transfer enhances EPC to secrete TRAIL protein, and induces apoptosis of ovarian cancer cell. There is a good clinical prospect for EPC in the gene therapy of ovarian cancer.

Cell Line, Tumor↗

PubMed2005

[Investigation on border mandibular movement of adolescent with angle III malocclusion in initial stage of permanent dentition].

OBJECTIVE: To investigate characteristics of the border mandibular movement of the adolescent with Angle III malocclusion and to find the correlations between craniofacial morphology and border mandibular movement function. METHODS: The subjects consisted of 21 adolescent patients with Angle III malocclusion in the initial stage of permanent dentition (mean age 12.3 years). 20 adolescents with individual normal occlusion served as control (mean age 12.8 years). The border mandibular movement of all cases in the two groups were traced and recorded by K6-1 Evaluation System and standardized lateral cephalograms were taken. RESULTS: The results revealed no significant difference in the maximal movement range between two groups, but indicated a positive association between the maximum jaw opening and both the mandible length (Go-Gn) and the L1-MP. The distance from ICP to maximal opening (D) was positively correlated with facial height and the L1-MP. While to adolescents with individual normal occlusion, the wider the maximal jaw opening was, the bigger the posterior facial height and the cephalometric values of mandibular ramus. The distance D positively correlated with the anterior lower facial height. CONCLUSION: Angle III malocclusion had its characteristics in the tracing and had a specific relationship with the craniofacial morphology.

Adolescent↗

PubMed2005

Anti-inflammatory effect and mechanism of osthole in rats.

OBJECTIVE: To investigate the anti-inflammatory effect and mechanism of osthole (Ost). METHODS: Carrageenan -induced hind paw edema in rats were prepared. The nitric oxide synthase (NOS) activity was measured by NADPH -diaphoras stain assay, nitric oxide (NO) content by Griess diazotization assay, malondialdehyde (MDA) content by Thibabituric acid mehtods. And PG content was assaied by Uv -vis spectrophotometry with 278 nm after 0.5 mol/L KOH methanol reagent dissimilating. RESULTS: The increase in NO2(-) observed 4h after carrageenan administration was inhibited by Ost from 524.4 +/- 58.7/micromol/L(-1) NO2(-) for carrageenan alone to 461.5 +/- 68. 8,353.8 +/- 111.0/micromol/L NO2(-) for, respectively, carrageenan administered in combination with 50 mg/kg or 100 mg/kg Ost. It suggested Ost suppress inflammatory responses on NO levels in a dose -dependent manner (P < 0.05). In the presence of Ost 100 mg/kg, NOS activities remained at near blank control levels. Meanwhile results showed reduced malondialdehyde production (MDA) in the presence of Ost, which is one of the byproducts of lipid peroxidation. Ost 50, 100 mg/kg markedly suppressed the generation of PG in inflamed paws. CONCLUSION: Ost presents anti-inflammatory activities at the used models. The effects may be associated to a supression of content of PG, NO, MDA and cNOS activity by inhibition of calcium entry and elevating cGMP levels way.

Animals↗