Biomedical subjects

Gang Liu

Publications and source records attributed to Gang Liu.

At least 109 records · Page 6Linked to original sources

PubMed2005

Chlamydia pneumoniae and Mycoplasma pneumoniae in young children from China with community-acquired pneumonia.

Eighty-five cases community-acquired pneumonia (CAP) in children 5 years or younger, confirmed by chest X-ray, and 185 age-matched control patients with diarrhea or dermatitis from the Outpatient Department at Beijing Children's Hospital were enrolled into this study. Nasopharyngeal swab specimens were obtained from all subjects. Real-time PCR-based fluorescence assays were performed for Chlamydia pneumoniae and Mycoplasma pneumoniae. A nested PCR was also run for C. pneumoniae for comparison of assays. C. pneumoniae was found in 3 (3.5%) of CAP cases and in 4 (2.1%) of controls (P = 0.51). M. pneumoniae was found in 6 (7.1%) of CAP cases and in none of the controls (P = 0.001). The agreement rate of the 2 applied PCR methods used for C. pneumoniae detection was 98.5%. Our study demonstrates that M. pneumoniae may play a significant role in CAP affecting children up to 5 years in China, whereas C. pneumoniae in nasopharyngeal specimens was not associated with CAP in this age group.

Child, Preschool↗

PubMed2005

Effect of three flavonoids isolated from Japanese Polygonum species on superoxide generation in human neutrophils.

Three flavonoids, quercetin 3- O-glucoside-2''-gallate (QGG), quercetin 3- O-rhamnoside-2''-gallate (QRG) and kaempferol 3- O-glucoside-2''-gallate (KGG) were isolated from Japanese Polygonum species. The effect of these flavonoids on stimulus-induced superoxide generation in human neutrophils was assayed by measuring the reduction of cytochrome c. The tyrosyl or serine/threonine phosphorylation of neutrophil proteins and the translocation of p4(phox) and p67(phox) to the cell membrane were detected using specific monoclonal antibodies. The flavonoids used in this experiment significantly suppressed stimulus-induced superoxide generation in a concentration-dependent manner. FMLP-induced tyrosyl phosphorylation or PMA-induced serine/threonine phosphorylation and the translocation of the cytosolic proteins p47(phox) and p67(phox) to the cell membrane were suppressed in parallel to the suppression of the stimulus-induced superoxide generation.

Caryophyllaceae↗

PubMed2005

Molecular cloning of a novel rat gene Tsarg1, a member of the DnaJ/HSP40 protein family.

Beginning with a mouse gene mTSARG3, which was related to apoptosis of spermatogenic cells, bioinformatics was applied and a predicted novel rat gene full-length cDNA sequence was attained. Gene-specific primers were designed for PCR in rat testis cDNA library. A new gene Tsarg1 (GenBank Accession No. AY380804) was cloned, which is related to apoptosis in rat spermatogenic cells. The gene whose full cDNA length is 1176 bp containing 8 exons and 7 introns is located in rat chromosome 1q32-1q33, which encoded a protein containing 316 amino acid residues and being a new member of HSP40 protein family since the sequence contains the highly conserved J domain, which is present in all DnaJ-like proteins and is supported to have a critical role in DnaJ-DnaK protein-protein interactions. The results of RT-PCR and Northern blot analysis showed that Tsarg1 was specifically expressed in rat testis, which probably inhibits rat testis spermatogenic cell apoptosis.

Amino Acid Sequence↗

PubMed2005

A pathway-specific transcriptional regulatory gene for nikkomycin biosynthesis in Streptomyces ansochromogenes that also influences colony development.

DNA sequence analysis of a 7.5 kb XhoI DNA fragment from the region flanking the nikkomycin biosynthesis gene cluster in Streptomyces ansochromogenes revealed one 3.3 kb open reading frame (ORF), designated sanG. The deduced product of sanG (1061 amino acids), which is similar to PimR of Streptomyces natalensis, contains an OmpR-like DNA binding domain in its N-terminal portion and A- and B-type nucleotide binding motifs in the middle of the protein. Disruption of sanG abolished nikkomycin biosynthesis, reduced sporulation and led to brown pigment accumulation. All aspects of this complex phenotype were complemented by a single copy sanG which was integrated into the chromosome. The introduction of multiple copies of sanG resulted in increased nikkomycin production. S1 mapping results indicated that sanG is transcribed from at least three promoters (P1, P2 and P3), P1 being strongly upregulated when production of nikkomycins starts. Two putative transcription units for nikkomycin biosynthesis, starting from sanN and sanO, are dependent on the expression of sanG, whereas a putative transcription unit starting from sanF was not regulated by sanG. These results suggested that sanG encodes a transcriptional activator important for nikkomycin biosynthesis that, unusually, also has pleiotropic effects on secondary metabolism and development.

Amino Acid Sequence↗

PubMed2005

[Effect of high level spinal cord injury on rat heart function].

OBJECTIVE: To study the effects of high level spinal cord injury (SCI) on rat heart, and investigate the role of endothelin-1 (ET-1) in the harmful effects on heart after SCI. METHODS: Forty-eight male SD rats were randomly divided into six groups of 8 animals each: control group; 4-hour group: 4 th hour after injury to spinal cord at cervical 7 level; 12-hour group: 12 th hour after injury to 7 spinal cord at C7 level; 24-hour group with same injury; 48-hour group and 72-hour group, all with same injury. Mean arterial pressure (MAP), heart rate (HR), left ventricle systolic pressure (LVSP), and left ventricular maximum velocities of contraction (+/-dp/dt max) were recorded in each group. Lactate dehydrogenase (LDH), creatine kinase (CK), MB isoenzyme of creatine kinase (CK-MB) and ET-1 contents in the myocardium. were also measured. Specimens of the myocardium were harvested for ultrastructure examination with transmission electron microscopy. RESULTS: Hemodynamics variables including HR, MAP, LVSP and+/-dp/dtmax were significantly decreased in all the injury groups compared with that of control group (P<0.05 or P<0.01). These variables in 12-hour group showed lowest values among all the groups (all P<0.01). But the values of cardiac enzymes were much higher in five injury groups compared with that of control group (P<0.05 or P<0.01). ET-1 contents in serum and cardiac tissue raised markedly after the injury was inflicted to the animals (P<0.05), reaching peak at 12 hours (P<0.01). Ultrastructural examination of the myocardial tissue demonstrated that there were mild dissolution of myocardial fibrils and vacuolation of mitochondria at 12 hours after injury. CONCLUSION: High level SCI could induce myocardial injuries and an excessive production of ET-1 in circulation and myocardial tissue might play a role in myocardial damage after injury of the spinal cord at a high level.

Animals↗

PubMed2005

[Effect of spironolactone on left ventricular remodeling in patients with acute myocardial infarction].

OBJECTIVE: To investigate the effect of spironolactone on left ventricular remodeling (LVRM) in patients with acute myocardial infarction. METHODS: In this multicentric, randomized, controlled study, spironolactone 40 mg/d was randomly administered in addition to the routine treatment for patients with AMI. During the 6 months the serum PIIINP, BNP and echocardiography were examined in all patients to assess myocardial fibrosis, LV function and volume. RESULTS: A total of 88 AMI patients entered the study came from 4 hospitals in Shijiazhuang. There were 43 patients with anterior MI and 45 with inferior MI. In anterior MI group 23 patients received spironolactone and 20 accepted the routine treatment. In inferior MI group 23 received spironolactone and 22 accepted the routine treatment. In anterior MI group: (1) At 3rd, 6th month PIIINP and BNP serum levels were significantly lower in the spironolactone group compared with those in control group [PIIINP (260.2 +/- 59.9) vs (328.0 +/- 70.3) ng/L, P = 0.001, (197.1 +/- 46.3) vs (266.7 +/- 52.4) ng/L, P < 0.001], [BNP (347.4 +/- 84.0) vs (430.1 +/- 62.9) ng/L, P < 0.001, (243.7 +/- 79.7) vs (334.6 +/- 62.8) ng/L, P < 0.001]; (2) There were smaller LVEDD and LVESD in spironolactone group compared with those in control group after 6 months intervention [(51.0 +/- 5.5) vs (55.6 +/- 4.5) mm, P = 0.005, (35.7 +/- 4.6) vs (39.1 +/- 5.6) mm, P = 0.046]. However, in inferior MI group: (1) There were no significant differences in PIIINP and BNP values between the two groups after 6 months intervention; (2) There were no significant differences in the LVEDD, LVESD, LVEF after 6 months treatment. CONCLUSION: (1) In patients with anterior MI, spironolactone combined with the routine treatment could inhibit myocardial fibrosis and left ventricular dilation and prevent LVRM. (2) In patients with inferior MI, no significant difference in prevention of LVRM was found between the spironolactone combined with the routine treatment and the routine treatment alone.

Female↗

PubMed2005

[The relationship between expression of fas mRNA and apoptosis after traumatic brain injury in rats and the role of GM-1 in protecting the brain].

OBJECTIVE: To explore the mechanism of apoptosis after traumatic brain injury (TBI) in rats and elucidate the role of GM-1 by detecting the expression of Fas mRNA and apoptosis in hippocampi. METHODS: After creating the model of Marmarou cranio-cerebral trauma and offering GM-1 therapy, we observed the expression of Fas mRNA and apoptotic cell death using in situ hybridization and terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL) technique. RESULTS: Increased expression of Fas mRNA and increased apoptotic cells in hippocampi after TBI were observed. GM-1 could decrease the expression of Fas mRNA and apoptotic cell death. CONCLUSION: The increased expression of Fas mRNA may be a noteworthy cause of apoptotic cell death after traumatic brain injury. GM-1 may play a protective role by way of decreasing the expression of Fas mRNA and apoptotic cell death.

Animals↗

PubMed2005

[Forms and bio-availabilities of exogenous arsenic in purple soils].

This study showed that after As was added into purple soils for 10 days, 50.2%-61.1% of it transformed into residual As, occupying 68%-86% in original soils. For acid purple soil, the As forms were Al-As > Fe-As> Ca-As; for neutral purple soil, they were Ca-As > Al-As > Ca-As > Fe-As > A-As, and for calcic purple soil, they were Ca-As > Al-As > Fe-As >A-As. It is suggested that NH4Cl could be used as common extractant for different soils, because it slightly affected original As forms in soils, and showed a highly significant correlation (P = 0.01) to plant absorption. From pluralistic regressive analysis of plant As content and each As form, Al-As and Fe-As were the main available forms in acid purple soil, but A-As and Ca-As were the most important fractions in neutral and calcic purple soils. The study also showed that H3BO3 could restrain the F interference in the operation of As speciation separations.

Arsenic↗

PubMed2005

[An A/G polymorphism in muscle-specific creatine kinase gene in Han population in Northern China].

To explore the distribution about genotype and allele frequencies of Nco I polymorphism in the CKMM gene in Han population in Northern China, and investigate what the genotypes were, PCR-RFLP was used to examine the genotype and allele frequencies of 306 unrelated healthy persons. Sequencing was used to analyze all three genotypes. Chi2 test was used to compare the frequencies between Chinese Han population and foreign population. The Nco I polymorphism was A/G. The allele frequencies were as follows: A=86%,G=14% . The genotype frequencies were A/A=74%, A/G=24%, G/G=2% and they were in Hardy-Weinberg equilibrium. The site of Nco I in the CKMM from Chinese Han population had polymorphism. No significant difference was detected in genotype and allele frequencies between men and women. There were significant differences between Chinese Han population and those in Europe and America, but no significant difference was detected between Chinese population and Korean population.

Adolescent↗

PubMed2005

[Raman spectroscopic study of human tissues].

Raman spectroscopy has been applied to the investigation of human thyroid, lung, oviduct, ovarian, cervical, and uterine tissues. Thyroid and uterine tissues exhibit more Raman bands than the other tissues in the range from 500 to 3 500 cm(-1) with 514.5 nm excitation, while lung and cervical tissue do not show any bands. In the range of 600-1 800 cm(-1), uterine and ovarian tissues show 20 c only the Raman features of carotenoids near 1 004, 1 158, and 1 cm(-1). Remarkable differences between normal and follicular carcinoma samples of thyroid were observed by the absence of characteristic bands at 1 585 and 1 634 cm(-1) in the latter. The spectral intensity of lung cancerous sample is much lower than that of normal sample, by which normal and malignant samples can be discriminated. The results indicate that Raman spectroscopic technique will play an important rule in clinical diagnosing.

Diagnosis, Differential↗

PubMed2005

[Dynamic observation of pathological changes and expression of nuclear factor-kappaB in the intestinal mucosa of rats after diffuse brain injury].

OBJECTIVE: To investigate the dynamic pathological changes in the intestinal mucosa of rats and the role of activation of nuclear factor-kappaB (NF-kappaB) in the alteration in intestinal mucosal barrier dysfunction after diffuse brain injury. METHODS: The animal model established by Marmarou was used to produce diffuse brain injury. One hundred and fifty male Wistar rats were randomly divided into nine groups in terms of postinjury time: 1, 2, 4, 8, 12, 24, 48, 72, 168 hours after injury, and control group. Mucosal thickness, villous height and width were estimated under light microscope, and expression of NF-kappaB was assessed with immunohistochemical staining in control group to compare with those in injury groups. RESULTS: Mucosal thickness, villous height and width were diminished and the optical density of expression of NF-kappaB was much higher in the injury groups than those of control group. CONCLUSION: The structure of intestinal mucosa is damaged in the earlier stages after diffuse brain injury. NF-kappaB is activated by cellular stress, which may be involved in the pathogenesis of secondary intestinal lesion.

Animals↗

PubMed2005

[Correlation between the activation of AP-1 signal transduction pathway and metastasis of colorectal carcinoma].

OBJECTIVE: To investigate the binding activity of activator protein-1 (AP-1) with DNA probe in the colorectal carcinoma (CRC) tissues and surrounding tissues and explore the correlation between the activation of AP-1 signal transduction pathway and metastasis of CRC. METHODS: The AP-1 DNA binding activities were investigated by electrophoretic mobility shift assay (EMSA) in CRC specimens (T), surrounding tissues including 2 cm (P(2)), 5 cm(P(5)) far away from primary tumor margin and distal resection margin of the specimens (N). The mRNA expression level of vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9) were measured by quantitive reverse transcription polymerase chain reaction (Q- RT-PCR). RESULTS: The AP-1 DNA binding activity in T was significantly higher than those in P(2), P(5) and N (P< 0.05) tissues. There were significantly positive correlations between AP-1 DNA binding activity in tumor and invasive degree, lymphatic metastasis respectively (P< 0.01), but no correlation with histological classification and differentiation (P> 0.05). The transcription levels of VEGF and MMP-9 in CRC were significantly higher than those in P(5) and N (P< 0.01, P< 0.05) tissues. The transcription levels of VEGF and MMP-9 were significantly correlated with increasing AP-1 DNA binding activity (P< 0.01). CONCLUSIONS: AP-1 is significantly correlated to the invasion and metastasis in CRC. The activation of AP-1 signal transduction pathway might be involved in the angiogenesis and of degradation extracellular matrix during tumor metastasis.

Colorectal Neoplasms↗

PubMed2005

[In vitro study of the effects of estrogen receptor beta expression on the biological behavior of a human breast cancer cell line].

OBJECTIVE: To study effects of estrogen receptor beta (ER beta) on the biological behavior of a human breast cancer cell line MDA-MB-435. METHODS: Human ER beta cDNA was introduced into MDA-MB-435 cells by stable transfection. Effects of ER beta expression on cell proliferation and invasion were investigated by MTT, flow cytometry and transwell techniques. Cyclin A, cyclin E, cyclin D1, p21, MMPs, Ets-1, VEGF and b-FGF were detected by RT-PCR and/or Western blot or gelatin zymography. RESULTS: ER beta was shown to be able to significantly increase the proliferation and invasion of MDA-MB-435 cells in an estradiol-independent manner. The S phase distribution of the cells with ER beta overexpression was 46.8%, significantly higher than that of wild type (29.9%) and mock transfected cells (27.6%) (P = 0.01). In ER beta transfected cells, the expression of p21 decreased by 33.3% at mRNA level (P = 0.03) and by 47.4% at protein level (P = 0.02), respectively. The expression of MMP-9 increased by 91.3% at mRNA level (P < 0.01) and its activity was up-regulated by 67.3% (P = 0.02). Furthermore, the mRNA and protein levels of Ets-1 increased 62.2% (P = 0.01) and 51.0% (P = 0.01), respectively. No significant difference was observed in the mRNA levels of cyclin A, cyclin E, cyclin D1, MMP-1, MMP-2, MMP-7, VEGF and b-FGF among these cells. CONCLUSION: ER beta can enhance proliferation and invasion of breast cancer cells. Down-regulation of p21 and up-regulation of MMP-9 and Ets-1 may be involved in its mechanisms.

Breast Neoplasms↗

PubMed2005

[Relationship of microtubule and [Ca2+]cyt in wheat mesophyll protoplast].

By using immunofluorescence labeling technique and incubating the Fluo-3AM of Ca2+ fluorescein, wheat (Triticum aestivum) cultivars Lovrin 10 was selected as mesophyll protoplast material in this paper for studying the relationship between the pattern of microtubule and [Ca2+]cyt. Laser scanning confocal microscopy(LSCM) was used and pharmacologic examination was set. The results indicated there was a connection between calcium signaling and microtubule organization in wheat mesophyll protoplast. When the cytosolic calcium concentration distinctly ascends, the pattern of microtubule showed depolymerization; Depolymerization of microtubule could enhance extracellar calcium afflux.

Biological Transport↗

PubMed2005

[Fourier transform infrared spectroscopic study of different parts of wild growing edible mushrooms].

In this paper, vibrational spectra of different parts of fruiting bodies of wild growing mushrooms were recorded with Fourier transform infrared spectrometer. It was different for the spectra of cap skin, gill, cap meat and stem of the same mushroom. The great differences were found between cap skin and other parts of the same mushrooms of Russula virescens and Russula rubra, whereas the spectra of mushroom Termitomyces albuminosus show greated differences between gill and other parts. These indicate variety in the chemical composition of different parts of the same fruiting body. The results suggest that the mushrooms could be identified at the species level by comparison of the vibrational spectra of different parts of fruiting bodies of mushrooms.

Agaricales↗

PubMed2005

JNK: bridging the insulin signaling and inflammatory pathway.

Obesity and insulin resistance are strongly associated with systemic markers of inflammation and endoplasmic reticulum stress. c-Jun N-terminal kinases (JNK) are activated by inflammatory cytokines and have a key role in beta-cell apoptosis and in negative regulation of insulin signaling. JNK1-deficient mice are protected from diet-induced obesity and insulin resistance, while genetically obese mice with targeted mutations in JNK1 are leaner and have reduced insulin and blood glucose levels. These studies validate JNK as a link between inflammation and metabolic diseases and as a promising drug target. This review highlights recent advances in small-molecule inhibitors of JNK that have also been targeted for other diseases with an inflammatory component such as stroke, rheumatoid arthritis, and Alzheimer's and Parkinson's diseases.

Animals↗

PubMed2005

[Root activity and nitrogen assimilation of rice (Oryza sativa) under free-air CO2 enrichment].

With Free-Air CO2 Enrichment(FACE) technique, this paper studied the root activity and amino acid(aa) synthesis of rice (Oryza sativa )at low N(LN, 150 kgN x hm(-2)) and normal N(NN, 250 kgN x hm(-2)) under ambient air and elevated atmospheric CO2 (Ambient + 200 micromol x mol(-1)). Under elevated CO2, the xylem exudates per hill changed little, while the xylem exudates per stem declined by 1.4% - 21.7% as the result of greater tiller numbers. At tillering and heading stages, elevated CO2 increased aa N/inorganic N in xylem exudates by 11.1% - 143.1%, but did not affect the aa concentration in xylem exudates and the total amount of aa in roots significantly. However, at 35 days after heading, the aa N/inorganic N ratio decreased by 38.1% (LN) and 29.2% (NN) under elevated CO2. FACE also declined the aa concentration in xylem exudates by 34.0% (LN) and 44.7% (NN), and the total amount of aa by 50.8% (LN) and 40.0% (NN), which meant the retarded capability of aa synthesis in roots. N amendment led to a decrease of aa N/inorganic N in xylem exudates by 19.5% (Ambient) and 36.8% (FACE) at heading stage, as the result of unaffected aa and increased inorganic N concentration. There existed a significantly antagonistical CO2 x N interaction on aa N/inorganic N at heading stage.

Air↗

PubMed2005

[The functional integrity of imaging diagnostic equipments].

On the basis of introduction and analysis of three new medical imaging equipments, the article discusses the superiority of the function integrity that is a new concept, and its application in the development of medical equipments in 21st century.

Diagnostic Equipment↗