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Biomedical subjects

Jian Lu

Publications and source records attributed to Jian Lu.

At least 37 records · Page 2Linked to original sources
PubMed2006

[Expression of substance P in human laryngopharynx and gastrointestine in sudden erethistic death].

OBJECTIVE: To study the expression of substance P (SP) in human sudden erethistic death, and to seek objective morphological supports to diagnose sudden erethistic death for forensic medicine. METHODS: The expression of SP was detected with immunohistochemical technique on 15 human laryngopharynx and gastrointestine of sudden erethistic death, and 20 sudden death of heart attack as control. The images of SP were analyzed by image analyzer, and the positive indexes (PI) were calculated. RESULTS: SP expression in the experimental groups was significantly stronger than that in the control one (P < 0.001). CONCLUSION: SP expression can offer an objective morphological reference support for forensic diagnosing sudden erethistic death.

Adolescent↗
PubMed2006

[Influence of different doses of porcine pulmonary on the therapeutic effects in rats with oleic acid induced acute lung injury].

OBJECTIVE: To investigate the therapeutic effects and dose effect relationship of intratracheal instillation of different doses of porcine pulmonary surfactant (PPS) in rats with oleic acid (OA) induced acute lung injury (ALI). METHODS: Arterial blood gases and respiratory rate during the experiments, survival rate, lung index, total protein (TP) content in bronchoalveolar lavage fluid (BALF), tumor necrosis factor-alpha (TNF-alpha) level in plasma, light microscopy examination of lung specimens after the experiments were determined and performed in control group, OA (0.2 ml/kg) + saline, OA + PPS 50 mg/kg, OA+PPS 80 mg/kg, OA+PPS 100 mg/kg, OA+PPS 150 mg/kg, OA+PPS 200 mg/kg groups, respectively. RESULTS: In PPS 50 mg/kg group, arterial blood gases were improved and respiratory rate was reduced during the first 2 hours (P<0.05). Arterial blood gases and reduced breath rates respiratory rate were not improved in other PPS treatment groups but 4 hours-survival rate was lowered, lung index was decreased, protein content s in BALF and TNF-alpha level in serum were lowered, and pathological changes were ameliorated compared with group given saline after OA, especially in high dosage of PPS (150-200 mg/kg) group (P<0.05). CONCLUSION: Administration of PPS via trachea provides obvious effects on respiratory functions in rats with OA induced ALI, moreover PPS (> or =80 mg/kg) alleviates lung injury. There is no dose-effect relationship of PPS in PPS-treatment groups.

Acute Lung Injury↗
PubMed2006

Promotive effect of C/EBPepsilon overexpression on differentiation of human myelomonocytic leukemia cell line U-937.

BACKGROUND & OBJECTIVE: CCAAT-enhancer binding protein omega (C/EBPepsilon) is a kind of nuclear transcriptional factor expressed predominantly in myeloid cells, and may be a critical regulator of myeloid differentiation, which can activate the transcription of a subset of myeloid-specific genes. This study was to detect the cell-specific expression of C/EBPepsilon, and to investigate the effect of C/EBPepsilon overexpression on c-Myc expression, cell cycle distribution, and cell differentiation of human myelomonocytic leukemia cell line U-937. METHODS: The expression of C/EBPepsilon in 5 hematopoietic cell lines (U-937, NB4, HL-60, K-562 and Jurkat T cell lines) was tested by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). According to the RT-PCR results, human myelomonocytic leukemia cell line U-937 was selected and transfected with pcDNA3.1-C/EBPepsilon32 expression vector by electroperforation, and screened by G418 to yield positive clones which were termed U-937-C/EBPepsilon32. The expression of C/EBPepsilon and c-Myc in U937-C/EBPepsilon32 cells was detected by RT-PCR and Western blot; cell cycle and differentiation of U937-C/EBPepsilon32 cells was analyzed by flow cytometry. RESULTS: C/EBPepsilon overexpression obviously increased the expression of CD11b (a cell surface marker of granulocyte maturity). The positive rate of CD11b was significantly higher in U-937-C/EBPepsilon32 cells than in U-937 and U-937-pcDNA3.1 cells(92.56% vs. 77.46% and 74.81%), while c-Myc expression and cell cycle had no changes. CONCLUSION: C/EBPepsilon might be an essential transcriptional regulator for U-937 cells differentiating into granulocytes.

CCAAT-Enhancer-Binding Proteins↗
PubMed2006

[Segmentation-based multi-scale urban green space landscape].

In this study, three scales urban green space landscapes were generated by multi-resolution segmentation. With 50 and 300 pixels as the object segmentation thresholds, the small- and large-scale landscape object image layers were produced, and the two object image layers were obtained by the nearest neighbor classification method. The result of small-scale landscape classification image was segmented into middle-scale landscape image, and then classified. Green space information was extracted through vector form of object image layers of three scales landscape classification. The landscape indexes diversity, dominance, evenness, fractal dimension, fragmentation, and interior to edge ration were calculated, with the largest values of the former four indexes being 2.2, 0.681, 0.948, and 0.326, and the smallest values being 1.641, 0. 122, 0.707, and 0.113, respectively, indicating that the diversity, evenness and fragmentation decreased, while the dominance increased with increasing landscape scale. The method of multi-resolution segmentation to generate multi-scale landscape could meet the needs of urban green space landscape research.

Biodiversity↗
PubMed2005

Targeted drug delivery crossing cytoplasmic membranes of intended cells via ligand-grafted sterically stabilized liposomes.

In this study, we tested whether sterically stabilized liposomes (SSL) with surface ligands specific for the mu opioid receptor (MOR) can actively target MOR-expressing cells. Dermorphin, a selective MOR agonist, was conjugated to DSPE-PEG(3400) to obtain DSPE-PEG(3400)-dermorphin. Dermorphin-grafted SSL (dermorphin-SSL) was prepared by thin-film rehydration-extrusion and post-insertion method. DSPE-PEG(3400)-dermorphin and dermorphin-SSL retained the affinity to MOR as determined by receptor binding assay using [(3)H]DAMGO, whereas plain SSL without surface ligands showed no binding to the receptor. Cellular uptake of cholesteryl BODIPY encapsulated dermorphin-SSL was studied by microplate spectrofluorometry as well as fluorescent and confocal microscopy. Significant fluorescence signal was observed inside CHO-hMOR cells after the treatment with dermorphin-SSL, indicative of MOR-mediated endocytosis. In contrast, no uptake of dermorphin-SSL was found in naive CHO cells or CHO-hDOR cells that lack MOR. Taken together, these results demonstrate that dermorphin-SSL delivery system is capable of targeting intracellular components of MOR-expressing cells. Such a system may be applied to carry pharmaceutical agents to achieve region-specific delivery of analgesics and/or to attenuate side effects associated with opioids.

Animals↗
PubMed2005

Refined estimate of the incubation period of severe acute respiratory syndrome and related influencing factors.

Many epidemiologists have agreed that a refined estimate of the incubation period of severe acute respiratory syndrome (SARS) would need a sample size of about 200 cases and appropriate statistical methods enabling the inclusion of cases with defined periods of exposure. However, no such studies have been reported so far. Besides, determinants of the SARS incubation period remain unclear. In this study, 209 probable SARS cases with documented episodes of exposure between March 1 and May 31, 2003, in mainland China were included. A nonparametric method was used to analyze these data with defined periods of exposure to obtain the refined estimate of the SARS incubation period. Furthermore, the authors also explored the influence of various factors on the SARS incubation period by analysis of variance, linear regression analysis, and analysis of covariance. The estimates of mean and variance of the SARS incubation period were 5.29 days and 12.33 days(2), respectively; 90% of patients would have an incubation period of less than 11.58 days with a probability of 0.8, and 99% of patients would have an incubation of less than 22.22 days with a probability of 0.9. The affected area showed a highly significant effect on the incubation period (p < 0.001), but the contact pattern, occupation, gender, and age did not.

Analysis of Variance↗
PubMed2005

Inhibitors of phenylethanolamine N-methyltransferase devoid of alpha2-adrenoceptor affinity.

A series of 3-trifluoromethyl-1,2,3,4-tetrahydroisoquinolines was synthesized and evaluated for their phenylethanolamine N-methyltransferase (PNMT) inhibitory potency and affinity for the alpha(2)-adrenoceptor. Although their PNMT inhibitory potency decreased compared with corresponding 3-methyl-, 3-hydroxymethyl- or 3-unsubstituted-THIQs, some of them showed good selectivity due to their extremely low alpha(2)-adrenoceptor affinity.

Enzyme Inhibitors↗
PubMed2005

Modulation of androgen receptor transactivation by FoxH1. A newly identified androgen receptor corepressor.

Androgen signaling plays key roles in the development and progression of prostate cancer, and numerous ongoing studies focus on the regulation of androgen receptor (AR) transactivity to develop novel therapies for the treatment of androgen-independent prostate cancer. FoxH1, a member of the Forkhead-box (FOX) gene family of transcription factors, takes part in mediating transforming growth factor-beta/activin signaling through its interaction with the Smad2.Smad4 complex. Using a series of experiments, we found that FoxH1 repressed both ligand-dependent and -independent transactivation of the AR on androgen-induced promoters. This action of FoxH1 was independent of its transactivation capacity and activin A but relieved by Smad2.Smad4. In addition, the repression of the AR by FoxH1 did not require deacetylase activity. A protein-protein interaction was identified between the AR and FoxH1 independently of dihydrotestosterone. Furthermore, a confocal microscopic analysis of LNCaP cells revealed that the interaction between the AR and FoxH1 occurred in the nucleus and that FoxH1 specifically blocked the foci formation of dihydrotestosterone-activated AR, which has been shown to be correlated with the AR transactivation potential. Taken together, our results indicate that FoxH1 functions as a new corepressor of the AR. Our observations not only strengthen the role of FoxH1 in AR-mediated transactivation but also suggest that therapeutic interventions based on AR-coregulator interactions could be designed to block both androgen-dependent and -independent growth of prostate cancer.

Activins↗
PubMed2005

Metallothionein gene expression in peripheral lymphocytes and renal dysfunction in a population environmentally exposed to cadmium.

In order to study the validity of metallothionein (MT) gene expression in peripheral blood lymphocytes (PBLs) as a biomarker of cadmium exposure and susceptibility to renal dysfunction, MT mRNA levels were measured using reverse transcription polymerase chain reaction (RT-PCR) in PBLs from residents living in a cadmium-contaminated area. MT mRNA levels were found to increase with the increase of blood cadmium (BCd) and urinary cadmium (UCd) levels. Basal MT mRNA levels were significantly correlated with the logarithm of BCd levels and the logarithm of UCd levels confirming that MT expression in PBLs is a biomarker of cadmium exposure and internal dose. An inverse relationship was observed between in vitro induced MT-mRNA level in PBLs and urinary N-acetyl-beta-d-glucosaminidase (UNAG) suggesting that MT gene expression in PBLs may be used as a biomarker of susceptibility to renal toxicity of cadmium.

Adult↗
PubMed2005

Effects of molecular weight and concentration of arabinoxylans on the membrane plugging.

In this paper, arabinoxylans from wheat were isolated, purified, and degraded into four fractions with different molecular weight. The distribution of particle size was employed to evaluate the membrane plugging by beer. These arabinoxylans fractions were added into arabinoxylan-free beer to investigate the effects of molecular weight and concentration on the distribution of particle size in beer. Results showed that the fraction of arabinoxylans retained by a 0.22-mum pore size membrane was more easily affected by shearing and arabinoxylan concentration than the fraction of arabinoxylans retained by a 0.45-mum membrane. The effects of shearing, pH, and ethanol concentration of beer on the particle size distribution of the highest molecular weight arabinoxylan fraction in beer were also examined. General linear models (GLM) equations indicated that there was a positive correlation between the particle size distributions of arabinoxylans and shearing and ethanol content, while high molecular weight arabinoxylans particle size retained by the 0.45-mum membrane was not significantly (p > 0.05) influenced by pH value. Scanning electron microscope (SEM) photos showed that membrane plugging was significantly affected by the molecular weight of the arabinoxylans.

Beer↗
PubMed2005

Androgen receptor mutants detected in recurrent prostate cancer exhibit diverse functional characteristics.

BACKGROUND: Alterations in the function of androgen receptor (AR) and its signaling pathway may be responsible for the progression of prostate cancer. The goal of the present study was to investigate the potential roles of AR structural and functional alterations in the progression of prostate cancer, and the relationship between the structure and function of the AR. METHODS: AR gene in 58 prostate cancer samples was examined for mutations using PCR-single strand conformation polymorphism (SSCP) analysis and DNA sequencing. Effects of mutations on the structure and function of AR were investigated by androgen-binding assays and transactivation assays, respectively. RESULTS: Four novel somatic mutations (G142V, D221H, E872Q, and M886I) were identified from recurrent prostate cancer samples. None of the AR mutants differed from wild-type AR (wtAR) in their abilities to bind the synthetic androgen methyltrienolone. However, these mutated AR exhibited diverse functional characteristics as compared with wtAR. G142V and D221H showed increased responses to DHT. E872Q could be abnormally activated by 17beta-estradiol, progesterone, and cyproterone acetate (CPA). Furthermore, E872Q and M886I presented increased responses to DHT in the presence of coactivators TIF-2 and CBP, but not p300. On the other hand, although overexpression of corepressors N-CoR and SMRT could result in evident inhibition on DHT- or CPA-induced transactivity of wtAR and the AR mutants, N-CoR displayed stronger inhibitory effects on DHT-induced transactivity of the AR mutants (especially for E872Q and M886I) than that of wtAR. To our knowledge, this is the first characterization of enhanced inhibitory effects of corepressors on the transactivity of the AR mutants found in prostate cancer. CONCLUSIONS: The data presented here demonstrate that AR mutants found in prostate cancer had different functional alterations, which might play an important role in the progression of prostate cancer.

Aged↗
PubMed2005

Weak selection revealed by the whole-genome comparison of the X chromosome and autosomes of human and chimpanzee.

The effect of weak selection driving genome evolution has attracted much attention in the last decade, but the task of measuring the strength of such selection is particularly difficult. A useful approach is to contrast the evolution of X-linked and autosomal genes in two closely related species in a whole-genome analysis. If the fitness effect of mutations is recessive, X-linked genes should evolve more rapidly than autosomal genes when the mutations are advantageous, and they should evolve more slowly than autosomal genes when the mutations are deleterious. We found synonymous substitutions on the X chromosome of human and chimpanzee to be less frequent than those on the autosomes. When calibrated against substitutions in the intergenic regions and pseudogenes to filter out the differences in the mutation rate and ancestral population size between X chromosomes and autosomes, X-linked synonymous substitutions are still 10% less frequent. At least 90% of the synonymous substitutions in human and chimpanzee are estimated to be deleterious, but the fitness effect is weaker than the effect of genetic drift. However, X-linked nonsynonymous substitutions are approximately 30% more frequent than autosomal ones, suggesting the fixation of advantageous mutations that are recessive.

Animals↗
PubMed2005

The Kluyveromyces lactis gamma-toxin targets tRNA anticodons.

Kluyveromyces lactis killer strains secrete a heterotrimeric toxin (zymocin), which causes an irreversible growth arrest of sensitive yeast cells. Despite many efforts, the target(s) of the cytotoxic gamma-subunit of zymocin has remained elusive. Here we show that three tRNA species tRNA(Glu)(mcm(5)s(2)UUC), tRNA(Lys)(mcm(5)s(2)UUU), and tRNA(Gln)(mcm(5)s(2)UUG) are the targets of gamma-toxin. The toxin inhibits growth by cleaving these tRNAs at the 3' side of the modified wobble nucleoside 5-methoxycarbonylmethyl-2-thiouridine (mcm(5)s(2)U). Transfer RNA lacking a part of or the entire mcm(5) group is inefficiently cleaved by gamma-toxin, explaining the gamma-toxin resistance of the modification-deficient trm9, elp1-elp6, and kti11-kti13 mutants. The K. lactis gamma-toxin is the first eukaryotic toxin shown to target tRNA.

Anticodon↗
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

[Selectivity and individualization of transpedicular balloon kyphoplasty for aged osteoporotic spinal fractures].

OBJECTIVE: To investigate the selectivity and individualization of transpedicular balloon kyphoplasty for aged osteoporotic spinal fracture. METHODS: Twenty-two consecutive procedures were performed in 17 aged patients with osteoporotic spinal compression fractures from April 2002 to June 2004. The signal changes in different sequences were confirmed by magnetic resonance imaging before the procedures. This operation involved the percutaneous insertion of two inflatable bone tamps into a fractured vertebral body transpedicularly under fluoroscopic guidance. Every patient was treated individually, according to the results of radiography and CT scan before operation. Preoperative and postoperative complications, visual analogue scale, and radiographic findings such as vertebral height and Cobb angle were recorded and analyzed. RESULTS: All patients tolerated the procedure well with immediate relief of their back pain in 24 hours. There was no leakage of cement into the epidura. The mean loss percent of the anterior and middle vertebral heights were (35.32 +/- 13.15)% and (27.53 +/- 12.61)% before operation, and (14.21 +/- 12.43)% and (16.2 +/- 7.5)% after operation. The height restoration of vertebra was confirmed by X-ray after the procedure (P < 0.01). The mean kyphosis was improved from (25.3 +/- 4.2) degrees to (8.6 +/- 5.1) degrees. No complications occurred. No patient had nerve injury. The patients were allowed to walk next day after the procedure. CONCLUSION: The selectivity and individualization of transpedicular balloon kyphoplasty for aged osteoporotic spinal fractures has satisfactory short-term clinical efficacy. It is also an effective way to prevent complications.

Aged↗
PubMed2005

[Modeling for prediction of arabinoxylans solubilization and endo-xylanase random attacking during mashing].

A model describing the solubilization of arabinoxylans and degradation by endo-xylanase random attacking during mashing was developed. The model was expected to predict the arabinoxylans concentration in wort at the settings of different initial value and mashing parameters for diminishing the negative effects of arabinoxylans on brewing. Results showed that the modeling errors range for the final concentration of arabinoxylans in wort was -9.5% to +13.6%. The model prediction accuracy for industrial scale mashing process was lower than that in laboratory scale. The errors were given 16.8% and 17.9%, respectively. The simulation results showed that arabinoxylans concentration was increased with the increase of mashing-in temperature, but it was decreased with prolonging the mashing-in time. The effect of initial arabinoxylans in malt on arabinoxylans concentration in wort was more remarkable than that of endo-xylanase activity in grist.

Endo-1,4-beta Xylanases↗
PubMed2005

[Molecular cloning and expression of the severe acute respiratory syndrome-associated coronavirus nucleocapsid protein and its clinical application].

OBJECTIVE: To clone and express nucleocapsid (N) protein of the severe acute respiratory syndrome (SARS)-associated coronavirus, and to evaluate its antigenicity and application value in the development of serological diagnostic test for SARS. METHODS: SARS-associated coronavirus N protein gene was amplified from its genomic RNA by reverse transcript nested polymerase chain reaction (RT-nested-PCR) and cloned into pBAD/Thio-TOPO prokaryotic expression vector. The recombinant N fusion protein was expressed and purified, and its antigenicity and specificity was analyzed by Western Blot, to establish the recombinant N protein-based ELISA for detection of IgG antibodies to SARS-associated coronavirus, and SARS-associated coronavirus lysates-based ELISA was compared parallelly. RESULTS: The recombinant expression vector produced high level of the N fusion protein after induction, and that protein was purified successfully by affinity chromatography and displayed higher antigenicity and specificity as compared with whole virus lysates. CONCLUSION: The recombinant SARS-associated coronavirus N protein possessed better antigenicity and specificity and could be employed to establish a new, sensitive, and specific ELISA for SARS diagnosis.

Antibodies, Viral↗