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Biomedical subjects

Q Huang

Publications and source records attributed to Q Huang.

At least 253 records · Page 14Linked to original sources
PubMed1995

Alterations in intestinal bacterial flora modulate the systemic cytokine response to hemorrhagic shock.

To test the hypothesis that the resident gut flora plays an active role in modulating the cytokine response to hemorrhagic shock, plasma levels of interleukin-6 (IL-6) and tumor necrosis factor (TNF) were measured from the following three groups of rats before, immediately after, and 3, 8, or 24 h post-hemorrhagic shock (90 min at 30 mmHg)/sham shock: 1) rats with a normal gut flora (NF), 2) rats whose gut flora had been decontaminated with oral antibiotics (AD), and 3) rats with intestinal overgrowth with E. coli. In all three groups, portal and systemic TNF and IL-6 levels were 2- to 10-fold higher in the shock than the sham-shock rats (P < 0.05), with the highest TNF and IL-6 levels observed in the rats that were colonized with Escherichia coli (P < 0.05 vs. AD and NF). TNF levels were higher in the NF than the AD groups at 3 and 8 h postshock. The present study suggests that changes in the gut microflora modulate the systemic cytokine response to hemorrhagic shock with intestinal bacterial overgrowth leading to the greatest increase in plasma IL-6 and TNF levels.

Animals↗
PubMed1995

Lack of association between an interleukin-1 receptor antagonist gene polymorphism and systemic lupus erythematosus.

Non-MHC linked genes may contribute to genetic predisposition to the development of systemic lupus erythematosus. The possibility that cytokine genes may be involved was raised by the observation of increased frequency in expression of an uncommon allele of an interleukin-1 receptor antagonist gene polymorphism and SLE in a recent U.K. study. We have not been able to show any significant differences in expression of this allele in SLE patients as a whole or in any patient subgroups. Our results actually show a slight decrease in the expression of this allele in SLE patients compared with healthy controls and in SLE patients with malar rash compared with SLE patients without malar rash.

Alleles↗
PubMed1995

Increased frequency of the uncommon allele of a tumour necrosis factor alpha gene polymorphism in rheumatoid arthritis and systemic lupus erythematosus.

The frequency of the uncommon allele (TNF2) of a polymorphism in the promoter region of the tumour necrosis factor alpha (TNF alpha) gene in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) was found to be 3 times that of the normal anglo-saxon population. In SLE patients, this allele was strongly associated with HLA-DR3 expression and was also more frequent in patients who did not have malar rash. Functional studies of normal monocyte cytokine production in vitro showed that this genotype was associated with increased IL-1 alpha protein production but there were no differences in the production of TNF alpha protein.

Alleles↗
PubMed1995

Overexpressing cell surface beta 1.4-galactosyltransferase in PC12 cells increases neurite outgrowth on laminin.

Neurite outgrowth on cellular and extracellular matrices is mediated by a variety of cell surface receptors. Some of these receptors recognize peptide determinants, whereas others bind oligosaccharide ligands. Previous studies have suggested that cell surface beta 1.4-galactosyltransferase functions as one of these receptors during neurite outgrowth on basal lamina by binding to N-linked oligosaccharides in the E8 domain of laminin. However, these previous investigations have been limited to the use of galactosyltransferase inhibitory reagents to block neurite formation. Therefore, in this study, we investigated whether the level of surface galactosyltransferase directly affects the efficiency of neurite outgrowth, or rather, is incidental to neurite formation. Northern blot analysis and cell surface galactosyltransferase assays were used to select two stable PC12 transfectants that overexpress surface galactosyltransferase by approximately four-fold. Radiolabeled antibody binding to intact cells and indirect immunofluorescence confirmed the higher expression of surface galactosyltransferase on transfected cells, compared to controls. Both galactosyltransferase transfected cell lines exhibited markedly enhanced neurite initiation, neurite formation, and rates of neurite elongation by two- to three-fold. These studies demonstrate that the expression of laminin receptors can be rate-limiting during neurite outgrowth, and that the level of surface galactosyltransferase can modulate the frequency and rate of neurite formation from PC12 cells on laminin.

Animals↗
PubMed1995

Studies on metabolites of mycoparasitic fungi. IV. Minor peptaibols of Trichoderma koningii.

Three minor peptaibols, trichokonins (TKs)-Ia, Ib, and IX, were obtained from the culture broth of Trichoderma koningii Oudemans. Primary structures of these peptaibols were elucidated by ion-spray ionization mass spectrometry (ISI-MS) including the collision-induced dissociation (CID) technique together with two-dimensional nuclear Overhauser enhancement spectroscopy (NOESY).

Alamethicin↗
PubMed1995

Studies on metabolites of mycoparasitic fungi. II. Metabolites of Trichoderma koningii.

Four peptaibols, named trichokonins (TKs) V, VI, VII, and VIII, were isolated from the culture broth of Trichoderma koningii Oudemans. Primary structures of these peptaibols were elucidated by electrospray ionization mass spectrometry (ESI-MS), FAB-MS, and collision-induced dissociation (CID) techniques along with nuclear Overhauser enhancement spectroscopy (NOESY).

Alamethicin↗
PubMed1995

Enhanced adeno-associated virus vector expression by adenovirus protein-cationic liposome complex. A novel and high efficient way to introduce foreign DNA into endothelial cells.

Adeno-associated virus vector (AAV), a non-pathogenic integrating vector, can integrate on chromosome 19 in humans. But its gene transfer efficiency is quite low. In this study we combined adenovirus (Adv-5) capsid protein or the Fiber protein of Adv with liposome, termed adenosome (adenovirus protein-cationic liposome complex). This complex can bring AAV/CMV-LacZ to the endothelial cells, and improve the efficiency of gene transfer. It may be a novel, specific, stable and safe gene delivery system and will be widely used in human gene therapy.

Adenoviruses, Human↗
PubMed1995

Adenovirus mediated gene transfer of vascular smooth muscle cells and endothelial cells in vitro.

Introducing foreign gene(s) into vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) is the pre-requirement of gene therapy for cardiovascular diseases. We have explored the use of adenoviral vectors (Adv-CMV/LacZ) to transfer LacZ gene into cultured VSMCs and ECs. Our results demonstrated that adenoviral vectors transferred foreign gene into VSMCs and ECs high-efficiently with dose-dependent response pattern. The frequencies of transfection reached 100% at the viral titer of 10(9) pfu/ml. Comparing the sensitivities of VSMCs and ECs to adenoviral vectors, we found that ECs were more sensitive than VSMCs, of which the frequencies of transfection in ECs reached 80% while in VSMCs only 40% for 8 hrs after transfection. In addition, the transfection of ECs and VSMCs with adenoviral vectors was partly blocked by monoclonal antibodies to Fiber and Core protein of the adenoviral capsid, but not by monoclonal antibody to Hexon protein. It is suggested transfection of ECs and VSMCs with adenovirus vectors is mediated by Fiber or Core protein of adenoviral capsid proteins.

Adenoviruses, Human↗
PubMed1995

Comparison of plasma cytokine levels in rats subjected to superior mesenteric artery occlusion or hemorrhagic shock.

The overall goal of this study was to compare the effects of systemic hypotension (hemorrhagic shock) versus local gut ischemia (superior mesenteric artery (SMA) occlusion) on cytokine production and bacteria/endotoxin translocation. Sham or actual SMA occlusion led to an increase in tumor necrosis factor (TNF), which was greatest at the end of the occlusion period, while the IL-6 response peaked 3 h post-SMA occlusion. The TNF and IL-6 response after hemorrhagic shock differed from that observed after SMA occlusion in that the peak response occurred later and was of lower magnitude (p < .05). Although the animals subjected to SMA occlusion had a significantly increased incidence of bacterial translocation to both the mesenteric lymph nodes and systemic organs compared to rats subjected to hemorrhagic shock, in neither group was the blood level of endotoxin elevated and there was no association between bacterial translocation and cytokine levels. These results suggest that different models of intestinal ischemia have different cytokine profiles and that the early TNF response associated with SMA occlusion model is primarily due to the laparotomy.

Animals↗
PubMed1995

A study of biological function of retinoblastoma gene (Rb gene).

The human wild-type Rb gene cDNA has been cis- or trans inserted into the retrovirus vector DOL, resulting in a sense-expression vector DOLRB and an antisense-expression vector DOLRBAS of Rb gene. By eletroporation transfection techniques, the vector DOLRB has been introduced into the human breast carcinoma cell line MDAMB468 and human hepatocellular carcinoma cell line SMMC7721 both of which have an inactivated Rb gene and the vector DOLBAS, into normal human embryonic lung fibroblasts HEL cells. With the expression of Rb protein, the growth rate of the MDAMB468 cells is decreased by about 50%, their colony formation ability in soft agar is repressed completely, and their tumorigenicity in nude mice is repressed partially. Meanwhile, the cell population of G1 phase of Rb+ MDAMB468 cells is increased markedly. About 75% of transfected SMMC7721 cells have been killed by Rb gene product. For HEL cells, with the transient expression of antisense Rb gene, the Rb protein synthesis is reduced and the growth rate of those cells increased, but no colonies of HEL cells are formed in soft agar.

Animals↗
PubMed1995

The population association of glucokinase gene with type 2 (noninsulin-dependent) diabetes mellitus in Chinese.

The association of gluckinase (GCK) gene with type 2 (non-insulin-dependent) diabetes mellitus was investigated in 168 Chinese subjects (85 unrelated type 2 diabetics and 83 non-diabetic controls). The microsatellite polymorphism marker, GCK-5', was amplified with polymerase chain reaction. Four alleles were observed in Chinese population with length varying from 137bp to 143bp and the most common one being the 139bp allele 3. In comparison with non-diabetics, allele 4 was significantly increased in type 2 diabetes (10% versus 38, respectively; X2 = 6.773, P = 0.009); genotype 44 and 4X (X denotes any allele other than allele 4) were significantly increased in type 2 diabetes (16% versus 6% respectively; X2 = 6.439, P = 0.011). The frequency difference was also shown in overweight/obese subgroup comparison (X2 = 7.718, P = 0.021), but not in lean/normal-weight subgroup comparison. No differences of age of onset and frequency of positive family history were observed between type 2 diabetic patients with genotype 44 or 4X and those with XX. The risk for type 2 diabetes in Chinese with genotype 44 or 4X was about 3.5 times higher than in Chinese with genotype XX. Therefore, GCK gene was associated with Chinese type 2 diabetes.

Adult↗
PubMed1995

[Endoscopic sinus surgery in children].

Thirty-seven cases (67 sides) of chronic sinusitis treated with endoscopic sinus surgery (ESS) at the age of 8 to 17 years were evaluated in the paper. All the patients after ESS were followed up for a period of 2 to 24 months. Twenty-four out of 37 cases were primarily healed, 7 cases had delayed healing and 2 cases still had persistent inflammation during the period of follow-up. Among the 37 cases, 17 recovered completely and 20 recovered incompletely. The necessity, feasibility and indications of ESS in children were discussed.

Adolescent↗
PubMed1994

Trichokonin VI, a new Ca2+ channel agonist in bullfrog cardiac myocytes.

The effects of trichokonin VI (= gliodeliquescin A), a peptaibol isolated from the culture broth of Trichoderma koningii Oudemans, on L-type Ca2+ channel currents in single bullfrog atrial cells were investigated. Our results showed that trichokonin VI is a new potent agonist of L-type Ca2+ channels in cardiac membranes.

Alamethicin↗
PubMed1994

Oligonucleotides with novel, cationic backbone substituents: aminoethylphosphonates.

Oligonucleotide (2-aminoethyl)phosphonates in which the backbone consisted of isomerically pure, alternating (2-aminoethyl)-phosphonate and phosphodiester linkages have been prepared and characterized. One of these single isomer oligonucleotides (Rp) formed a more stable duplex with DNA or RNA than its corresponding natural counterpart. Hybrid stability was more pH-dependent, but less salt-dependent than a natural duplex. The specificity of hybridization was examined by hybridization of an oligonucleotide containing one (2-aminoethyl)phosphonate to oligonucleotides possessing mismatches in the region opposite to the aminoethyl group. In contrast to oligonucleotides containing (aminomethyl)-phosphonate linkages, oligonucleotide (2-aminoethyl)phosphonates were completely stable to hydrolysis in aqueous solution. These oligonucleotides were resistant to nuclease activity but did not induce RNase H mediated cleavage of a complementary RNA strand. Incubation in a serum-containing medium resulted in minimal degradation over 24 hours. Studies of cell uptake by flow cytometry and confocal microscopy demonstrated temperature dependent uptake and intracellular localization. (2-Aminoethyl)phosphonates represent a novel approach to the introduction of positive charges into the backbone of oligonucleotides.

Aminoethylphosphonic Acid↗
PubMed1994

Refined 1.8 A resolution crystal structure of the porcine epsilon-trypsin.

Porcine epsilon-trypsin is a three-chain inactivated trypsin from the limited autolysis of porcine beta-trypsin. It is cleaved at positions Lys60-Ser61 and Lys145-Ser146. The crystal structure has been determined by using the molecular replacement method, and refined at 1.8 A resolution. The R-value of final model is 0.184. Comparison with the electron density map of porcine beta-trypsin (PTRY) in complex (BBIT), and with that of native bovine beta-trypsin (HTNA), revealed no obvious changes except at the autolysis positions, and no changes at the active center were observed. The autolysis at positions Lys60-Ser61 and Lys145-Ser146 does not affect the conformation of His-57 in the active center and therefore cannot explain for a loss in porcine epsilon-trypsin activity.

Animals↗
PubMed1994

IT15 gene expression in fetal human brain.

To examine the expression of the gene which causes Huntington's disease (HD), IT15, during development, in situ hybridization of radiolabeled riboprobes was performed in human fetal (gestational ages 20-23 weeks) and adult brain. Optical densities of autoradiographs were determined in various brain regions and compared to cell density in those regions. IT15 expression was found in all regions of the fetal and adult brain, and there was a high degree of correlation of autoradiographic signal with cell number in all regions but germinal matrix in fetal brain and white matter in adult brain. These two regions are notable for their significant proportion of glial cells, and suggest that IT15 expression is predominantly neuronal. There was no preponderance of IT15 expression in striatal compartments in fetal brain as demonstrated by acetylcholinesterase activity, nor was there differential expression of IT15 in brain regions known to be particularly affected in HD. IT15 gene expression is present by 20 weeks gestation in human brain, and at that stage of development exhibits a pattern of distribution which is similar to adult brain. If a developmentally-regulated role for IT15 exists in the pathogenesis of HD, it must occur prior to 20 weeks gestation.

Aged↗