Biomedical subjects

Q He

Publications and source records attributed to Q He.

At least 109 records · Page 6Linked to original sources

PubMed2000

[Expression of alpha 1-4 integrins in hypertrophic scar fibroblasts].

OBJECTIVE: To determine the expression levels of alpha 1-4 integrins in hypertrophic scar fibroblasts and investigate the role that alpha 1-4 integrins may play in the process of hypertrophic scar formation. METHODS: The membrane protein was extracted from hypertrophic scar and normal skin tissues. The content of alpha 1-4 integrins of the membrane protein was detected by immunoblotting method. The locations of alpha 1-4 integrin expression were examined by immunohistochemical stain. RESULTS: 1. Higher concentration of alpha 1-4 integrins was identified in the membrane protein extracted from hypertrophic scar than from normal skin. 2. In normal skin, the expression of alpha 1, alpha 2 and alpha 3 integrins located on the epidermal cell surface but not on the dermal fibroblast surface. In the hypertrophic scar, not only did the epidermal cell surface express alpha 1-3 integrins, but also the fibroblast surface expressed alpha 1-4 integrins. CONCLUSIONS: The expressions of hypertrophic scar fibroblast surface integrins are subjected not only to cell-extracellular matrix adhesion, but also to intracellular/extracellular signal transduction. Integrins may play an important role in regulating much of fibroblast behavior, including growth, differentiation, phenotype, and in scar tissue remodelling.

Adolescent↗

PubMed2000

[AP-1 mediated signal transduction in thrombin-induced regulation of PAL-1 expression in human mesangial cells].

OBJECTIVE: To evaluate activator protein-1 (AP-1) mediated mechanisms in thrombin-induced qlasminogen activator inhibitor-1 (PAI-1) expression in cultured human glomerular mesangial cells (MCs). METHODS: Electrophoretic mobility shift assay (EMSA) was employed to assess AP-1 DNA-binding activity, and Western blot hybridization was used for quantification of c-fos and c-jun, two subunits of AP-1 dimers. PAI-1 activity and mRNA expression were analysed by the fibrin plate assay and Northern hybridization, respectively. RESULTS: Thrombin concentration enhanced PAI-1 activity in the supernatant and stimulated PAI-1 mRNA expression in cultured MCs. PAI-1 activity was blocked by hirudin, a specific inhibitor of thrombin. Further study demonstrated that thrombin promoted AP-1 DNA-binding activity but exerted little effect on c-fos or c-jun. Curcumin (AP-1 inhibitor), staurosporine (PKC inhibitor), and genistein (PTK inhibitor) all reduced AP-1-mediated PAI-1 mRNA expression induced by thrombin in cultured MCs. CONCLUSION: The present study indicates that in cultured human MCs, thrombin stimulates PAI-1 expression through an AP-1 signal pathway, which may be mediated by PKC and PTK.

Cells, Cultured↗

PubMed2000

[Retroviral transduction of a mutant erbB-2 gene into human CD34+ derived dendritic cells].

OBJECTIVE: To successfully transduce a mutant erbB-2 gene into normal human CD34(+)-derived dendritic cells (DCs) and verify gene expression in these transduced dendritic cells. METHODS: The packaging cell line PA317 was transfected with mutant erbB-2 gene DNA and the virus produced was used to infect packaging cell line PG13. The virus produced by PG13 was used to infect CD34(+)-derived dendritic cells by the spinoculation method using flasks coated with fibronectin material to facilitate retrovirus gene transter efficiency and the mutant erbB-2 gene expression was assessed by ABC staining and FACScan methods. RESULTS: A mutant erbB-2 gene packaging cell line was produced and this mutant gene was transduced into human CD34(+)-derived DCs. It was verified that the relatively large numbers of the transduced DCs expressed the mutant erbB-2 protein which was eradicated of the ability to transform mouse NIH3T3 fibroblast cells. CONCLUSIONS: Human DCs can be gene-modified and these gene-modified DCs may be useful in stimulating T lymphocytes for immunotherapy.

3T3 Cells↗

PubMed2000

[Surgery for lung cancer complicated by bronchial asthma].

OBJECTIVE: To assess surgery for lung cancer complicated by bronchial asthma. METHODS: Lung hilum denervation was performed for asthma during radical resection of lung cancer. One patient with peripheral bronchogenic carcinoma in the right upper lobe underwent upper lobectomy and extensive dissection of lymph-nodes. Simultaneously, lung hilum denervation was done by complete amputation of the sympathetic and parasympathetic nerves around the lung hilum. Another patient with central bronchogenic carcinoma in the left upper lobe underwent lung autotransplantation. Pneumonectomy was performed, and the tumor parts of the lung were resected subsequently and the preservable parts of the lung were replanted into the bed of the upper lobe. RESULTS: Follow-up showed that the two patients had been alive with tumor free for 80 months and 17 months respectively and the time of postoperative mechanical ventilation was 4 and 18 hours. The frequency of asthma paroxysm decreased and the severity attenuated. Parameters of blood gas and lung function were improved. CONCLUSIONS: The poor lung function caused by asthma should not be regarded as a contradiction for the removal of lung cancer. Complete denervation around the lung hilum during the radical resection of lung cancer may contribute to the better treatment of lung cancer and asthma.

Aged↗

PubMed2000

[The St14 (DXS 52) VNTR in a Guangdong Han population and detection of hemophilia A carriers].

OBJECTIVE: To investigate the genetic polymorphism of the St14 (DXS 52) variable number tandem repeat (VNTR) in normal individuals in Guangdong, and to evaluate the efficacy of this marker for the gene diagnosis of hemophilia A. METHODS: 125 unrelated healthy individuals (male 21, female 104) and 4 hemophilia A families were detected using amplified-fragment-length polymorphism (Amp-FLP). RESULTS: 11 allelic fragments ranging from 700 to 1,810 bp in size and 7 different genotypes in males, 17 different genotypes in females were observed, respectively. The allele frequencies were 0.0044 to 0.4803. The polymorphism information contents (PIC) was 0.7335, and the heterozygosity was 0.432. Four families with hemophilia A were analyzed and 2 of them were informative for linkage analysis. In one family, 2 females were determined to be normal individuals, not carriers, one female carrier was detected in the other family. CONCLUSION: St14 (DXS 52) was a useful polymorphism marker for carrier detection of hemophilia A in southern Chinese population, and it was different from those in Caucasian.

China↗

PubMed2000

[Immune reconstitution in immunosuppressed pigs with human immune competent cells].

To reconstitute the immune system of the pig with human immune cells after destroying or suppressing it, so that the transplant immunoreactivity between human and pig could be monitored in vivo. Fifteen Chinese Neijiang pigs were divided into 3 groups. Group A (n = 5) received immunosuppression through intravenous infusion of methotrexate (MTX), myleran and cyclophosphamide (CTX). Group B received intraperitoneal injection of human bone marrow and spleen cells (HBSC) after the same treatment as group A. Group C (n = 5) received intravenous infusion of HBSC after the same treatment as group A. Blood routines and biochemical analysis were monitored. The chimerisms of human cells were supervised through immunohistochemistry of cytospin of peripheral blood from recipient pigs and flow cytometry of the same specimen and immunohistochemistry of frozen tissue sections and paraffin sections. All pigs in group A survived definitely. Group B and C survived 3 days to 54 days and 15 hours to 60 days respectively. The peripheral white blood cell count (WBCC) of group A, B and C decreased to the bottom 7 days after drug administration, about 1%-10% of the normal level. After transplantation, the WBCC of group B and C recovered more slowly than those of group A. Human cells were found in the recipient pigs of group B and C after transplantation through immunohistochemistry of peripheral blood cytospin and flow cytometry. Infiltration of human cells was found in the spleens and lungs of group C and D through immunohistochemistry. The chimerism of human cells in recipient pigs could be established by transplanting human bone marrow and spleen cells into immunosuppressed pigs. It is possible that XGVHD occurs in the recipient, which offers a novel animal model for studies on immunoreactivity of pig-to-human xenotransplantation. The proportions of human cells in peripheral blood of recipient pigs are low long after transplantation through both intraperitoneal injection and intravenous infusion.

Animals↗

PubMed2000

[Effect of xanthone from Canscora lucidissima on cultured myocytes anoxia-reoxygenation injuries].

The anoxia/reoxygenation model of cultured neonatal rats myocardial cells were developed, according to Laarse's method: anoxia and glucose deficiency for 60 min followed by reoxygenation and re-exposure to glucose for 30 min. The results showed that the survival rate of myocardial cells in the anoxia group was significantly decreased, release of lactate dehydrogenase (LDH) from myocytes was increased and membrane fluidity was decreased, all the changes were much more severe in the reoxygenation group. 30 min before anoxia, addition of xanthones: 1,8-dihydroxy-3, 5-dimethoxyxanthone, 1-hydroxy-3,5-dimethoxyanthone and 1-hydroxy-3,7,8-trithoxyxanthone, isolated from Canscora lucidissima increased the rate of myocardial cells and membrane fluidity, decreased the release of LDH. These results suggested that xanthone may provide some protective effects on the anoxia/reoxygenation damages on myocardium.

Animals↗

PubMed2000

[Determination of trace elements Cu, Zn, Mg, Cr, Mn in serum of people with hepatoma, cirrhosis, hepatapstema disease].

Using AAS method, we detected serum Zn, Cu, Mn, Cr, Mg in the people with hepatoma, cirrhosis and hepatophyma disease. The results showed that the level of serum Cu of people with hepatoma and cirrhosis were significantly higher than those in the healthy control and with hepatophyma disease (P < 0.01). The levels of serum Mn, Cr of those with hepatoma and cirrhosis disease were significantly lower than those with hepatophyma and the healthy control (P < 0.01). It is concluded that determination of Cu, Mn, Cr may be one of the methods to diagnose hepatoma and cirrhosis disease.

Adolescent↗

PubMed1999

Basis for recognition of cisplatin-modified DNA by high-mobility-group proteins.

The anticancer activity of cis-diamminedichloroplatinum(II) (cisplatin) arises from its ability to damage DNA, with the major adducts formed being intrastrand d(GpG) and d(ApG) crosslinks. These crosslinks bend and unwind the duplex, and the altered structure attracts high-mobility-group domain (HMG) and other proteins. This binding of HMG-domain proteins to cisplatin-modified DNA has been postulated to mediate the antitumour properties of the drug. Many HMG-domain proteins recognize altered DNA structures such as four-way junctions and cisplatin-modified DNA, but until now the molecular basis for this recognition was unknown. Here we describe mutagenesis, hydroxyl-radical footprinting and X-ray studies that elucidate the structure of a 1:1 cisplatin-modified DNA/HMG-domain complex. Domain A of the structure-specific HMG-domain protein HMG1 binds to the widened minor groove of a 16-base-pair DNA duplex containing a site-specific cis-[Pt(NH3)2[d(GpG)-N7(1),-N7(2)]] adduct. The DNA is strongly kinked at a hydrophobic notch created at the platinum-DNA crosslink and protein binding extends exclusively to the 3' side of the platinated strand. A phenylalanine residue at position 37 intercalates into a hydrophobic notch created at the platinum crosslinked d(GpG) site and binding of the domain is dramatically reduced in a mutant in which alanine is substituted for phenylalanine at this position.

Amino Acid Sequence↗

PubMed1999

Cis-regulation of inter-allelic exchanges in mutation at human minisatellite MS205 in yeast.

Tandemly repeated DNA is a major component of the human genome, and includes loci contributing to human disease. Minisatellites include the most variable human loci described to date, and the mechanisms by which this variation is generated in humans have been studied in detail. Integration of human minisatellites into yeast not only provides a model for further dissecting the molecular basis of length change mutation at these loci, but also more generally allows the study of complex recombinational events in yeast. We have used human minisatellite MS205 integrated into yeast to study the structural details of length change mutations. Apart from showing that mutation at this locus in yeast has features similar to those observed at some minisatellites in humans, including meiosis-specificity, and polarity, in which exchange events are localised to one extremity of the array, we here, for the first time, directly demonstrate that a flanking element in yeast regulates the mutation process. The results therefore support the hypothesis that flanking initiators are involved in minisatellite mutation in humans. Furthermore, mutant alleles showed more complex rearrangements in one orientation than the other. The data also suggest that the mutational pathway for deletions might be different from the pathway generating inter-allelic exchanges and duplications.

Alleles↗

PubMed1999

Modulation of peripheral blood mononuclear cell activation status during Salmonella-triggered reactive arthritis.

OBJECTIVE: To determine the activation status of mononuclear cells in the peripheral circulation during the acute phase and the recovery phase of Salmonella-triggered reactive arthritis (ReA). METHODS: Peripheral blood mononuclear cells (PBMC) were obtained from 8 patients with Salmonella infection (4 with ReA and 4 without) and were studied by reverse transcription-polymerase chain reaction for messenger RNA (mRNA) of proinflammatory and antiinflammatory cytokines, by flow cytometry (FC) for cell surface activation and adhesion molecules, by immunofluorescence (IF) microscopy for bacterial antigens, and by FC, IF, and DNA fragmentation on gel for signs of apoptosis. RESULTS: During the acute phase of the infection, PBMC were activated in all patients, as characterized by high levels of expression of CD14, CD11b, and CD11c on monocytes. In the patients with ReA, PBMC also had the capacity to produce interleukin-1beta (IL-1beta), IL-6, IL-8, IL-10, and tumor necrosis factor alpha. During the amelioration of disease, monocyte activation was decreased in all patients. A complete down-regulation of CD14 was detected only in the patients with ReA, whereas the expression of CD14 in the patients without ReA was positive and was similar to that in healthy controls. In addition, cytokine mRNA levels decreased regardless of the presence of Salmonella antigens in blood cells in all 4 patients with ReA. CONCLUSION: High levels of expression of some activation and adhesion molecules and elevated levels of mRNA for certain cytokines that are predominantly produced by monocytes were found in PBMC from patients with acute Salmonella-triggered ReA, which suggests that these cells are activated. On the other hand, complete down-regulation of CD14 and a marked decrease in the cytokine production capacity during amelioration of the disease suggest that suppression of PBMC activity might be involved in recovery from ReA.

Acute-Phase Reaction↗

PubMed1999

A normalized identity-by-state statistic for linkage analysis of sib pairs.

A sib-pair analysis was performed on a simulated data set for a fictitious disease, with a prevalence of approximately 3% to 6%. The disease could manifest itself in a severe or mild form and the analyses focused primarily on families with the mild form, barring any misdiagnoses. The numbers of shared genes identical by descent (IBD) and identical by state (IBS) were used to detect linkage between the marker loci and the disease. The results of the two methods were compared. We considered the distribution of the number of shared alleles IBS (for different parental allele combinations) and suggest a normalized IBS method. A large proportion of pedigrees in this data set had at least one homozygous parent or both parents sharing a common gene, thus generating the need for an adjustment of the IBS method. Our results indicate that the normalized IBS method gives results similar to those obtained by the traditional IBD approach. The adjusted score requires no assumptions be made with regard to the allele frequencies.

Alleles↗

PubMed1999

Performance of the nonparametric linkage analysis using GENEHUNTER for a complicated genetic disease.

The nonparametric linkage (NPL) analysis of the GENEHUNTER program was applied to one set of the simulated data of Problem 2, GAW11. We conducted a straightforward screening of the genome to evaluate the performance of the NPL test, with respect to its ability to detect linkage on specific disease loci. Our findings indicate that disease genes were detected with relatively good power, despite the presence of a complex inheritance pattern. We found that the NPL test varies depending on penetrance rates and gene frequencies, however, we conclude that it is a useful tool for linkage analysis.

Alleles↗

PubMed1999

Capillary array electrophoretic NMR of proteins in biological buffer solutions.

The capillary array electrophoretic NMR (CA-ENMR) was developed to study protein mixtures in biological buffer solutions of high ionic strength. By enhancing the strength of the effective electric field across the sample, the technique permits the detection of the electrophoretic motion of 1 mM lysozyme in 50 mM NaH(2)PO(4) aqueous solution, which was previously not achievable using conventional ENMR. Heat-induced convection was dramatically reduced by blocking convective current loops and by improving the efficiency of heat exchange. Thus, the capability of ENMR study of electrolyte solutions was extended from low to high ionic strength. In addition, capillary walls reduced rf-induced electrical eddy current, thereby maintaining good probe Q factors. Because of its parallel configuration to the static magnetic field, the capillary array chamber produced no susceptibility distortions of the ENMR signal. The technique offers great potential in characterizing multiple protein conformations and protein interactions in solution.

Buffers↗

PubMed1999

Local reactions and IgE antibodies to pertussis toxin after acellular diphtheria-tetanus-pertussis immunization.

Local reactions and pertussis toxin specific immunoglobulin E antibodies (PT-IgE) were investigated in healthy children following primary and booster immunization with a combined diphtheria tetanus acellular pertussis vaccine (DTPa) including pertussis toxin, filamentous haemagglutinin and pertactin. A primary series of DTPa was administered to 150 infants, and 104 of them received a booster dose of DTPa combined with inactivated polio vaccine at 2 years of age. PT-IgE was measured in serum samples from 72 children using a modified nitrocellulose RAST. Primary immunization was associated with low incidence of local reactions (1%-5%). After the booster dose 21% of children had a local reaction >/=20 mm. Local reactions after the booster dose tended to be more common in children who had experienced reaction at primary immunization. PT-IgE was detected in 18% and 86% of children following primary and booster vaccinations, respectively. Allergic and non-allergic children did not differ in PT-IgE responses. After primary immunization, elevated PT-IgE levels were found more often in children with a family history of allergy than in those without known allergy in the family. Children with local reactions had significantly higher pre- and post-booster PT-IgE levels and median post-booster pertactin IgG and diphtheria-IgG levels than children without local reactions. Conclusion Acellular pertussis immunization induces IgE antibodies to pertussis toxin, especially after booster vaccination. The higher median pre- and post-booster levels of pertussis toxin specific immunoglobulin E and post-booster levels of IgG to pertactin and diphtheria in children with local side-effects reflect a multifactorial immunological mechanism of such reactions.

Child, Preschool↗

PubMed1999

A novel aminosteroid is active for proliferation inhibition and differentiation induction of human acute myeloid leukemia HL-60 cells.

A novel aminosteroid, 2beta-(4'-methyl-1'piperazinyl)-3alpha,17beta-dihydroxyl+ ++-5alpha-androstane (HY), was found to inhibit proliferation of HL-60 leukemia cells and induce these cells to differentiate toward macrophage-like cells from the following evidence. (1) It inhibited HL-60 cell proliferation by cell counts, colony counts and MTT assay; (2) It caused morphological changes toward macrophage-like cells after culture for 6 days; (3) It induced NBT reduction activity; (4) It induced alpha-naphthyl acetate esterase activity and (5) it induced CD11b and CD14 expression indicated by flow cytometry analysis. There is potential for this novel aminosteroid in the treatment of myeloid leukemia.

Androstane-3,17-diol↗

PubMed1999

Fallout beryllium-7 as a tracer in soil erosion investigations.

Recent developments in the use of the environmental radionuclides 137Cs and 210Pb for documenting medium-term soil erosion rates must be seen as an important advance. However, measurements of these radionuclides provide estimates of medium-term (i.e. ca. 45 or 100 years) soil redistribution rates and there is a need to explore the potential for using complementary radionuclides, to estimate erosion rates associated with individual events or short periods. Beryllium-7 (7Be, t0.5 = 53 days) has the potential to fulfil these requirements. This contribution presents some preliminary results from an investigation undertaken in a field near Crediton, UK, which successfully demonstrates the potential for using 7Be as a tracer in soil erosion investigations.

Beryllium↗

PubMed1999

Genetic deletion of proteins resembling Type IV pilins in Synechocystis sp. PCC 6803: their role in binding or transfer of newly synthesized chlorophyll.

Upon non-denaturing gel electrophoresis of Synechocystis sp. PCC 6803 thylakoid extracts, a Type IV pilin-like protein encoded by open reading frame sll1694 was found in chlorophyll-containing bands. The Synechocystis sp. PCC 6803 genome also encodes two similar open reading frames, sll1695 and slr1456. Even though transcripts of sll1694 and slr1456 could be detected, deletion of the three open reading frames in systems with normal chlorophyll content had no effect. However, Sll1694 was found to affect the rate of chlorophyll synthesis and of the assembly of chlorophyll-binding proteins. In the sll1694/sll1695 deletion mutant in a PS I-less/chlL- background, which is unable to synthesize chlorophyll in darkness, chlorophyll synthesis during the first hours of illumination after dark incubation was 30% slower than in the PS I-less/chlL- strain. Moreover, the biogenesis of chlorophyll-protein complexes with a 77K chlorophyll fluorescence emission maximum at 685 mm was delayed by several hours in this mutant whereas the rate of biogenesis of photosystem II was not significantly affected. Furthermore, results of non-denaturing gel electrophoresis indicated that a chlorophyll-binding complex formed during the early hours of chlorophyll synthesis was altered in stability and mobility upon deletion of the three open reading frames. We propose that the protein encoded by sll1694 is involved in, but is not absolutely required for, delivering chlorophyll to nascent photosystems and antennae.

Amino Acid Sequence↗