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Lin Zhang

Publications and source records attributed to Lin Zhang.

At least 163 records · Page 9Linked to original sources
PubMed2005

Reconstruction of air contaminant concentration distribution in a two-dimensional plane by computed tomography and remote sensing FTIR spectroscopy.

This research combined open path FTIR (OP-FTIR) technique and computed tomography (CT) to reconstruct air contaminant concentration distribution in a two-dimensional plane. Remote sensing FTIR instrument was used to scan radial beam geometry and obtain path integrated concentration (PIC) data of acetone gas in the measuring plane. Smooth basis function minimization (SBFM) algorithm was adopted to reconstruct gaseous concentration distribution. For the purpose of finding out the preferable number of Gaussians used in SBFM algorithm, single-Gaussian, double-Gaussian, and three-Gaussian models were used respectively. Experimental results showed that the reconstruction result of acetone concentration distribution by SBFM algorithm with double-Gaussian model agreed with real distribution more qualitatively and quantitatively than single-Gaussian and three-Gaussian. Also, it has been proved that simulated annealing algorithm used in the optimization process of SBFM reconstruction was feasible and effective. Although computed tomography and remote sensing FTIR technique (CT-RS-FTIR) is still at the laboratory study stage, with further improvement of SBFM algorithm and beam geometry, it promises to be used in air pollution monitoring widely.

Acetone↗
PubMed2005

Orthogonal signal correction used for noise elimination of open path Fourier transform infrared spectra.

Open path Fourier transform infrared (OP-FTIR) spectroscopy is qualified in detecting mixtures by multivariate calibration methods such as partial least squares (PLS); however, its applications are still restricted by background noise, which is unavoidable for OP-FTIR spectra and cannot be resolved solely by multivariate calibration methods. Hence OP-FTIR spectra are often pretreated before the data are subjected to the multivariate calibration model. A new preprocessing technique, orthogonal signal correction (OSC), was presented in this paper. The principle of OSC is to remove the part in X orthogonal to Y, and it is implemented based on PLS and nonlinear iterative partial least squares (NIPALS) algorithm. The approach was applied to three different data sets of PLS model. It performed much better than classical PLS when handling data with noise but comparably when processing on the simulated data. Moreover, OSC could reduce the complexity of model, which would facilitate the interpretation of the models. The results reveal that the proposed method gives much better prediction than the classical PLS and is very promising for the wide use of OP-FTIR. The preprocessing technique, auto-scaling, and second-order derivatives (SOD) were also considered.

Air Pollutants↗
PubMed2005

Enhanced antitumor effect of the combination of tumstatin gene therapy and gemcitabine in murine models.

Targeting tumor endothelium is an important strategy for cancer therapy. We evaluated the effectiveness of gene therapy, that is, intramuscular delivery of plasmid DNA encoding tumstatin (pSecTag2B-tum), combined with gemcitabine administration in vitro and in vivo, using colon carcinoma (CT26) and Lewis lung carcinoma (LLC) murine models. The in vitro growth-inhibitory and proapoptotic effects of gemcitabine and/or tumstatin on human umbilical vein endothelial cells (HUVECs) and mouse endothelial cells (SVEC4-10), respectively, were assessed. in vitro, conditioned medium from pSecTag2B-tum-transfected COS cells inhibited the growth of endothelial cells but not of CT26 or LLC cells, whereas gemcitabine inhibited the growth of both endothelial cells and CT26 and LLC cells. Mice bearing subcutaneously established CT26 or LLC tumors received pSecTag2B-tum alone or in combination with gemcitabine to assess tumor growth inhibition. in vivo, combined treatment with pSecTag2B-tum and gemcitabine significantly decreased tumor growth through increased inhibition of tumor angiogenesis and increased tumor cell apoptosis compared with either agent alone. Enhanced antiproliferative and proapoptotic activity of the combination therapy on tumor-associated endothelial cells was calculated to be significant. This study suggests that combined treatment by the intramuscular delivery of plasmid DNA encoding tumstatin and gemcitabine augments tumor growth inhibition by suppressing angiogenesis and enhancing apoptosis in murine models. A combination of these agents could be used in future studies and translated into the clinical setting.

Angiogenesis Inhibitors↗
PubMed2005

Oncolytic HSV exerts direct antiangiogenic activity in ovarian carcinoma.

In the present study, we investigated the ability of replication-restricted herpes simplex virus (HSV) 1716 lacking ICP34.5 to infect endothelium and disrupt tumor vasculature. HSV-1716 efficiently infected and killed mouse endothelial cell lines H5V and MS1 cells, as well as human umbilical vein endothelial cells in vitro. Capillary tube formation by endothelial cells was inhibited by HSV-1716 in vitro and in vivo. Following intratumoral administration of oncolytic HSV-1716, HSV-glycoproteins could be detected in CD31-positive tumor vascular endothelium by immunostaining. Viral DNA was recovered from highly purified microdissected tumor vascular endothelium. Furthermore, endothelium of tumors treated with HSV-1716 exhibited expression of tissue factor, a marker of endothelial damage. Importantly, HSV antigen and DNA were also detected in endothelium distant from foci of active tumor infection. After intravascular inoculation of HSV-1716, viral glycoproteins were detected in association to tumor endothelium, but not vascular endothelium of different organs. Purified tumor endothelial cells showed high proliferative capability and were susceptible to HSV-1716 infection and killing ex vivo while endothelium from normal organs was not. We conclude that oncolytic HSV-1716 exerts direct antiangiogenic effects, which may contribute to the overall therapeutic efficacy of the virus.

Angiogenesis Inhibitors↗
PubMed2005

Differences in activity of cytochrome C oxidase in brain between sleep and wakefulness.

STUDY OBJECTIVES: Increased mRNA level of subunit 1 cytochrome c oxidase (COXI) during wakefulness and after short-term sleep deprivation has been described in brain. We hypothesized that this might contribute to increased activity of cytochrome oxidase (COX) enzyme during wakefulness, as part of the mechanisms to provide sufficient amounts of adenosine triphosphate to meet increased neuronal energy demands. DESIGN: COX activity was measured in isolated mitochondria from different brain regions in groups of rats with 3 hours of spontaneous sleep, 3 hours of spontaneous wake, and 3 hours of sleep deprivation. The group with 3 hours of spontaneous wake was added to delineate the circadian component of changes in the enzyme activity. Northern blot analysis was performed to examine the mRNA levels of 2 subunits of the enzyme COXI and COXIV, encoded by mitochondrial and nuclear DNA, respectively. SETTING: Laboratory of Biochemistry, Department of Animal Biology, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania. PARTICIPANTS: 2-month-old male Fischer rats (N = 21) implanted for polygraphic recording. MEASUREMENTS AND RESULTS: For COX activity, there was a main effect by analysis of variance of experimental group (P < .0001) with significant increases in COX activity in wake and sleep-deprived groups as compared to the sleep group. A main effect of brain region was also significant (P < .001). There was no difference between brain regions in the degree of increase in enzyme activity in wakefulness. Both COXI and COXIV mRNA were increased with wakefulness as compared to sleep. CONCLUSIONS: There is an increase in COX activity after both 3 hours of spontaneous wake and 3 hours of sleep deprivation as compared with 3 hours of spontaneous sleep in diverse brain regions, which could be, in part, explained by the increased levels of bigenomic transcripts of the enzyme. This likely contributes to increased adenosine triphosphate production during wakefulness. ABBREVIATIONS: ADP, adenosine diphosphate; ATP, adenosine triphosphate; COXI, cytochrome c oxidase subunit 1 mRNA; COX, cytochrome c oxidase (protein); CREB, cyclic AMP response element binding protein; DNA, deoxyribonucleic acid; EDTA, ethylenediaminetetraacetic acid; EEG, electroencephalography; EMG, electromyography; GABP, GA binding protein; HEPES, 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid; mRNA, messenger ribonucleic acid; NADH, nicotinamid adenine dinucleotide, reduced; NDII, NADH dehydrogenase subunit 2 mRNA; NRF, nuclear respiratory factor.

Animals↗
PubMed2005

Haptoglobin phenotype, sleep-disordered breathing, and the prevalence of cardiovascular disease: the Sleep Heart Health Study.

BACKGROUND: Diabetes is an independent risk factor for cardiovascular disease, and there is growing evidence that sleep-disordered breathing also may increase the risk of cardiovascular disease. The mechanism responsible for increased susceptibility of people with diabetes to cardiovascular disease is thought to share several features with sleep-disordered breathing, notably increased oxidative stress. We recently demonstrated that a particular haptoglobin phenotype that is associated with differential antioxidant activity is an independent risk factor for cardiovascular disease in individuals with diabetes. We therefore sought to determine whether sleep-disordered breathing and cardiovascular disease are more strongly associated among people with the unfavorable haptoglobin phenotype. METHODS: We tested this hypothesis in 2612 middle-aged and older participants from the Sleep Heart Health Study. Haptoglobin phenotyping was performed by gel electrophoresis. Respiratory disturbance index was assessed by standard methods. Logistic regression analysis was performed to estimate the association between haptoglobin phenotype and cardiovascular disease, adjusting for known cardiovascular risk factors (age, sex, diabetes, smoking, lipid levels, and hypertension). Possible modification by haptoglobin phenotype of the association of sleep-disordered breathing with cardiovascular disease prevalence was explored by examining interaction terms. RESULTS: We found no significant association between haptoglobin phenotype and prevalent cardiovascular disease in this cohort, nor were significant interactions found between haptoglobin phenotype and sleep-disordered breathing on the prevalence of cardiovascular disease. CONCLUSIONS: Sleep-disordered breathing did not appear to interact with haptoglobin phenotype in modifying the association with prevalent cardiovascular disease in the Sleep Heart Health Study. These findings could be due to the absence of association or to survivor bias in these cross-sectional analyses.

Aged↗
PubMed2005

Comparison of the efficacy of 1-day high-dose quadruple therapy versus 7-day triple therapy for treatment of Helicobacter pylori infection.

BACKGROUND: The proton pump inhibitor (PPI)-based 7-day triple therapy is the regimen with the highest cure rates for eradication of Helicobacter pylori infection and has been recommended as the first-line regimen in the world. It had been reported that a 1-day quadruple therapy could also successfully cure 95% of the H. pylori infected patients. OBJECTIVES: To observe the efficacy of 1-day high-dose quadruple therapy versus 7-day triple therapy for treatment of H. pylori infection, and to observe side-effects of the two different regimens. METHODS: This randomized, open, parallel-controlled study was conducted at Renji Hospital between November 2004 to March 2005. A total of 80 consecutive patients with non-ulcer dyspepsia, who were H. pylori positive proven by both rapid urease test and histology were included and randomly assigned to 1-day quadruple therapy or 7-day triple therapy. Thirty-nine patients were administered with 1-day high-dose quadruple therapy including esomeprazole 40 mg b.i.d., colloidal bismuth subcitrate 440 mg q.i.d., amoxicillin 2 g q.i.d. and metronidazole (400 mg q.i.d.) for 1 day. Forty-one patients received a standard 7-day triple therapy consisting of esomeprazole 20 mg b.i.d., clarithromycin 500 mg b.i.d. and amoxicillin 1 g b.i.d. for 7 days. The eradication rates were evaluated by the (13)C-urea breath test at least 4 weeks after completion of a course treatment. RESULTS: Seventy-seven patients completed the trial and three patients dropped out. The eradication rates in the 1-day therapeutic group and the 7-day therapeutic group were 39.5% (15/38) and 84.6% (33/39), respectively. There was a statistically significant difference between the two groups (P < 0.0001). Short-lasting and self-limiting side effects including thirst, a metallic taste, diarrhea and abdominal pain were reported in three patients (7.9%) in the 1-day group and seven patients (18%) in the 7-day group (P = 0.31). CONCLUSIONS: A 1-day high-dose quadruple therapy with amoxicillin, metronidazole, bismuth salt, and esomeprazole is not effective for eradication of H. pylori compared with the standard 7-day triple therapy.

Adult↗
PubMed2005

MEKK1 transduces activin signals in keratinocytes to induce actin stress fiber formation and migration.

Activins and other members of the transforming growth factor beta family play a critical role in morphological changes of the epidermis that require epithelial cell movement. We investigated the molecular pathways in the transmission of activin signals that lead to actin reorganization and epithelial cell migration. We found that activins cause the activation of RhoA but not of Rac and CDC42, leading to MEKK1-dependent phosphorylation of JNK and transcription factor c-Jun. Through a RhoA-independent mechanism, the activins also induce p38 activity in keratinocytes from wild-type but not from MEKK1-deficient mice. Although neither pathway is dependent on Smad activation, the MEKK1-mediated JNK and p38 activities are both essential for activin-stimulated and transcription-dependent keratinocyte migration. Only JNK is involved in transcription-independent actin stress fiber formation, which needs also the activity of ROCK. Because ROCK is required for JNK activation by RhoA and its overexpression leads to MEKK1 activation, we propose a RhoA-ROCK-MEKK1-JNK pathway and a MEKK1-p38 pathway as Smad-independent mechanisms in the transmission of activin signals. Together, these pathways lead to the control of actin cytoskeleton reorganization and epithelial cell migration, contributing to the physiologic and pathological effects of activins on epithelial morphogenesis.

Actins↗
PubMed2005

[A multiplex for simultaneous amplification of three Y-STR loci using modified primers].

OBJECTIVE: To develop a multiplex method for simultaneous detection of Y-STR loci. METHODS: The primers of Y-STR loci were devised for use in the simultaneous amplification of three Y-STR loci (DYS390, DYS391, DYS393). RESULTS: Simultaneous amplification of the three Y-STR loci was successfully performed using the modified primers in which the fragment length of DYS391 was shortened from 279-287 bp to 142-150 bp, and at the same time, the virile specificity of DYS393 was enhanced. CONCLUSION: The use of new-devised primers of Y-STR loci is a valid approach to rapid detection of multiple Y-STRs loci; it is worthy to be recommended in the field of forensic science.

Chromosomes, Human, Y↗
PubMed2005

[Expression of PDGF-B after fluid percussion brain injury in rats].

OBJECTIVE: To elucidate the changes of PDGF-B chain in the brain injured by fluid percussion. METHODS: The expression of PDGF-B protein was studied by immunohistochemistry and the results were assessed by image analysis system. RESULTS: Enhanced expression of PDGF-B protein induced by fluid percussion injury was seen at 1 h, and its marked up-regulation was noted at 4-7 days, and then the expression became decreased but it remained above the control levels till 14 days after injury. CONCLUSION: Fluid percussion brain injury induced expression of PDGF-B. The regular change pattern of PDGF-B level in time course seems to be of value in estimating the age of brain injury.

Animals↗
PubMed2005

[Genetic polymorphisms of fifteen short tandem repeat loci in Chengdu Han population].

OBJECTIVE: To acquire the population genetic data of fifteen short tandem repeat (STR) loci in Chengdu Han population. METHODS: A total of 210 EDTA-blood specimens were collected from the unrelated individuals in Chengdu Han population. The DNA samples were extracted with Chelex method and amplified by multiplex PCR technique. The PCR products were analyzed by an automatic genetic analyzer; the relative fragment's lengths of PCR products were calculated by gene scan analysis software and afterward genotyped by genotype software. RESULTS: Fifteen STR loci of the 210 samples showed a successful result of genotyping. The heterozygosities of the fifteen STR loci in Chengdu Han population were found to be 0.529-0.881; the combined exclusion probability and discrimination power for the fifteen STR loci in Chengdu Han population were determined to be 0.999998 and 7.3 x 10 (-17); respectively. CONCLUSION: The distinct genotype of fifteen STR loci and the sex of sample could be unveiled just through PCR and electrophoresis once, and a higher measured value could be obtained for both the combined discrimination power and the exclusion probability; the fifteen STR loci can meet the needs of the parentage testing and personal identification in forensic medicine.

Asian People↗
PubMed2005

[Vaginal paravaginal repair in treatment of severe anterior vaginal prolapse and cystocele].

OBJECTIVE: To explore the rationality, efficacy and safety of vaginal paravaginal repair (VPVR) in treating anterior vaginal prolapse and cystocele. METHODS: Twenty-five consecutive women with stage II to IV and grade II-III anterior vaginal prolapse and cystocele evaluated by pelvic organ prolapse quantification (POP-Q) and Baden-Walker half way system were treated by VPVR. One hundred and one concomitant procedures for reconstructive pelvic surgery were also performed. The VPVR consisted of a thorough entry from the vesicovaginal space under the inferior pubic ramus into the retropubic space, exposing the area of the arcus tendineus fascia pelvis (ATFP), placing nonabsorbable sutures around ATFP on either side and fixed to appropriate locations on the bladder fascia and anterior vaginal walls. Tying of these sutures resulted in dramatic elevation of the lateral superior sulci, as well as prolapsed vesica. Patients were followed up after operation. The cure rate was estimated subjectively and objectively, according to POP-Q and Baden-Walker half way system. RESULTS: All patients had their surgery completed by VPVR. The average operative time was 40 min and estimated blood loss was 70 ml. Two minor intraoperative hemorrhage occurred during dissection of retropubic space and there were no other complications. No morbidity after operation was observed either. Postoperatively, two patients developed obstructive voiding and urinary retention. One recovered completely in a few days, the other has improved slowly for 2 months. Patients were followed up for 2 - 14 months. Two patients with asymptomatic stage I or grade I cystocele were found by examination between 2 and 6 months after operation. Our objective cure rate was 92% and subjective cure rate was 100% respectively at a mean of 6 months after operation. CONCLUSIONS: Since VPVR can restore the normal lateral attachment of the pubocervical fascia to pelvic side wall at ATFP, it is a reasonable, safe and effective procedure to correct severe anterior vaginal prolapse and cystocele.

Aged↗
PubMed2005

[Root biomass of different stand-age Pinus yunnanensis forests and its distribution pattern in different soil depths].

With average-tree-specific sampling method, the authors measured the root biomass of Pinus yunnanensis forests with different stand ages in Yongren County, Yunnan Province. The results indicated that total root biomass increased from 8.50 t x hm(-2) in young stand (15-17 yr) to 11.70 t x hm(-2) in middle-aged stand (30-32 yr), and to 18.91 t x hm(-2) in mature stand (60-130 yr). Among different stand age classes, the biomass of coarse roots (>10 mm) varied greatly (1.5-12.3 t x hm(-2)), whereas those of medium (5-10 mm) and fine (<5 mm) roots showed less variation (medium roots 1.4-1.6 t x hm(-2), fine roots 5.3-6.2 t x hm(-2)). The root biomass of mature stand decreased with soil depth, approximately 93% of total underground biomass being distributed in surface layer (0-30 cm), and only 7% in deeper layer (30-115 cm).

China↗
PubMed2005

[Primary study of recombinant immunotoxin IL-18-PE38 in treating rheumatoid arthritis].

OBJECTIVE: To establish a kind of gene therapy method of rheumatoid arthritis, to construct the interleukin-18-PE38 fusion gene expression vector and to explore the expression of the fusion gene in the chondrocytes and 3T3 cells. METHODS: Interleukin-18-PE38 fusion gene was cleaved from plasmid PRKL459k-IL-18-PE38 by restriction enzyme digestion, then linked with vectors PsecTag2B and transformed into competence bacteria, positive clones were selected and confirmed by restrictive enzyme (EcoRI) digestion assay. The rearrangement plasmid PsecTag2B-IL-18-PE38 was transfected into 3T3 cells and mouse chondrocytes by liposome protocol (experimental group), null vector was used as negative control, and the transient expression was identified by fluorescence Restrictive enzymes digestion analysis revealed that the length of the interleukin-immunocytochemical assay. RESULTS: 18-PE38 fusion gene was 6000 bp. Fluorescence immunocytochemical method showed that fluorescence intensity of the experimental group is strong,while fluorescence intensity of the control group is weak. CONCLUSION: The eukaryotic expression vector PsecTag2B-IL-18-PE38 is established successfully which can be expressed in the 3T3 cells and mouse chondrocytes. Our results lay a foundation for the further investigation for rheumatoid arthritis therapy.

3T3 Cells↗
PubMed2005

[Forensic applications of the sequencing of mitochondrial DNA cytochrome oxidase subunit I and II gene for idenfication of Sarcosaphagous flies (diptera)].

OBJECTIVE: This study was based on a 278 and 635 bp region of the gene for cytochrome oxidase subunit I and I (CO I and CO II ) encoding region of mtDNA; the aim was to solve the problems in identifying Sarcosaphagous flies, particularly in the flies' larvae and eggs which could not be identified only by use of their morphologyical features. METHODS: Samples of sarcosaphagous flies and larvae were collected from those on the corps of rabbits on the grassland in the Huhhot district and of a pig on the sandy ground in the Dunhuang district. The mtDNA of flies and their larvae and eggs was extracted using the Chelex technique. Polymerase chain reactions were conducted on a Perkin-Elmer 9600 thermal cycler, followed by vertical non-denaturing polyacrylamide gelectrophoresis. PCR products were purified using the Nucleic Acid Purification Kit. Sequences of both strands were obtained by direct sequencing of the double-stranded PCR product using one of the PCR primers and the ABI PRISM Big Dye Terminator Cycle Sequencing Kit. Sequence reactions were electrophoresed on ABI Model 377 DNA Sequencers. A neighbour-joining tree using the Tamura and Nei model of nucleotide substitution was constructed using the MEGA2. 1 package. RESULTS: A 278 and 635 bp region of the gene for CO I and CO II encoding region of mtDNA of Sarcosaphagous flies and their larvae and eggs was noted to show the percentages for the sequence divergence within species (less than 1%) and the sequence divergence between species (above 3%). For species that diverged from all others by a relatively large percentage and had small within-species variation, the least percentages of sequence divergence were given which distinguished any individual within that species from any other species. CONCLUSION: A 278 and 635 bp region of the gene for CO I and CO II encoding region of mtDNA of Sarcosaphagous flies and their larvae and eggs has been effectively used for the molecular phylogeny and the identification of their species group. CO I and CO II, or CO II, is better than CO I.

Animals↗