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Biomedical subjects

Bo Han

Publications and source records attributed to Bo Han.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Detection of IFN-gamma level in single CD8+ T cell].

AIM: To establish a new method capillary electrophoretic immunoassay laser-induced fluorescence (CEIA-LIF), to detect IFN-gamma level in single CD8(+) T cell. METHODS: CD8(+) T cells were isolated from peripheral blood of two patients with severe aplastic anemia(SAA) and one normal person by Ficoll-Hypaque gradient centrifugation and then were purified by immunomagnetic microbead separation. Then purified CD8(+) T cells were incubated with digitonin for 15 min followed by FITC-anti-IFN-gamma mAb for 20 min. The single cell was detected continuously by CEIA-LIF. The feasibility of the method was confirmed by inverted microscopy and laser scanning confocal fluorescence microscopy. RESULTS: The IFN-gamma content in purified CD8(+) T cells was detected under the condition of cell-membrane integrity. The IFN-gamma level in single CD8(+) T cell from 2 SAA patients was (151.53+/-28.92)zmol and (223.72+/-45.23)zmol, respectively, and much higher that from normal control (47.47+/-17.97)zmol ( P=0.001). CONCLUSION: It is feasible to quantitate IFN-gamma in single CD8(+) T cell by CEIA-LIF. CEIA-LIF might be useful in the clinical detection of intracellular cytokines.

Antigen-Antibody Complex↗
PubMed2005

[A retrospective study on the complications after modified parotidectomy in benign tumors of parotid gland].

OBJECTIVE: A retrospective clinic study is presented of surgical patients undergoing a modified parotidectomy with conserving the sub-superficial musculoaponeurotic system (sub-SMAS) and great auricular nerve and reconstructing by the stemocleidomastoid flap (SF). The incidence of clinical complications was observed after the parotidectomy. METHODS: 226 patients were divided randomly into four groups. Group 1 (94 cases) were operated by the conserving the sub-SMAS. Group 2 were operated by the sub-SMAS and constructed by SF. Group 3 (57 cases) were treated by the subcutaneous flap (sub-CF). Group 4 (33 cases) were received by sub-CF and SF. The surgical technique was described and the incidence of clinical Frey's syndrome was evaluated by minor test (starch-iodine test) and observed gustatory sweating syndrome. The feeling and concave of the region of auricular lobule were followed up. RESULTS: The incidence of Frey's syndrome in group 1 (5.32%) or group 2 (4.76%) was significantly lower than that of group 3 (49.1%) or group 4 (51.5%) through by subjective observation and minor test (P < 0.005). The significance between group with SF and group without SF existed in protecting the concave of the region of auricular lobule (P < 0.05). The feeling of the region of auricular lobule had no change by preserving the great auricular nerve. CONCLUSION: There was good effect to prevent gustatory sweating syndrome in parotidectomy of reserve parotid fascia. The aesthetics and sense of the region of auricular lobule could be prevented by using SF and reserving the great auricular nerve.

Face↗
PubMed2005

Urokinase-type plasminogen activator system and breast cancer (Review).

Malignant tumors have a capacity to degrade the extracellular matrix (ECM) by controlled proteolysis. One proteolytic system involved in these processes is the urokinase-type plasminogen activator (uPA) system, which consists of uPA, uPA receptor (uPAR) and uPA inhibitors 1 and 2 (PAI-1 and PAI-2). In the past two decades, study of the uPA system in human breast cancer has yielded valuable insights. Increased levels of uPA, PAI-1 and uPAR have been reported to be associated with poor prognosis in patients with breast cancer. Furthermore, uPA and PAI-1 may be new prognostic markers for axillary node-negative patients. To date, a growing body of evidence has suggested that uPA system promotes tumor metastasis by several different mechanisms, not just by breaking down the ECM. This article is focused on reviewing the current understanding of uPA system members as prognostic markers in breast cancer, and their cellular localization and tissue distribution. Correlations of the uPA system with other informative markers of breast cancer are also discussed.

Breast Neoplasms↗
PubMed2005

[The mechanisms responsible for the therapeutic effects of anti-Fas ligand antibody on viral myocarditis in mice].

OBJECTIVE: Viral myocarditis (VM) is one of the most common acquired myocardial diseases in children. However, its pathogenesis is not clear. Recent studies indicate that the cytotoxicity mediated by cytotoxic T lymphocyte (CTL) plays an important role in the development of myocardial injury involved in VM. Apoptosis mediated by Fas/FasL pathway is an essential mechanism of target cells damage by CTL. In this study, the authors investigated the regulatory effects of neutralizing anti-Fas ligand (anti-FasL) antibody on apoptosis and caspase-3 expression in experimental coxsackievirus B3 myocarditis and the role of the CTL mediated apoptosis in myocardium through Fas/FasL pathway in the development of VM. METHODS: A total of 80 BALB/c mice were used in the experiments. They were divided randomly into the following groups: normal control group (Gr1), CVB3 control group (Gr2), IgG control group (Gr3) and anti-FasL antibody therapy group (Gr4). The mice in Gr2, Gr3 and Gr4 were inoculated with 0.15 ml of TCID(50) 10(9)/ml coxsackie virus B3 (CVB3) and the mice in Gr1 with 0.15 ml of Eagle reagent. The mice in Gr3 and Gr4 were inoculated with IgG (0.1 mg/kg) and FasL antibody (0.1 mg/kg) on days 0 and days 3 after inoculation (p.i.), respectively. Eight mice in each group were sacrificed on day 10 p.i. Histopathological studies and terminal transferase-mediated dUTP-biotin nick end labeling (TUNEL) assays were used to quantify inflammation, necrosis and apoptosis in myocardium. The expression of active caspase-3 in myocardium was determined by immunohistochemistry. Caspase-3 mRNA and CVB3 mRNA were analyzed by reverse-transcription polymerase chain reaction (RT-PCR). RESULTS: (1) Caspase-3 activation and apoptosis were seen in the myocardium of mice with myocarditis. They had a significantly positive correlation with the changes of myocardial histopathologic scores (r = 0.81, P < 0.05; r = 0.73, P < 0.05). (2) The pathologic scores, average percentages of apoptotic cardiomyocytes, expression of active caspase-3 (protein and mRNA) and expression of CVB3 mRNA in myocardium of mice in Gr4, were significantly reduced compared to those in the myocardium of mice in Gr2 (P < 0.01, P < 0.01, P < 0.01, P < 0.01, and P < 0.05, respectively) and Gr3 (P < 0.01, P < 0.01, P < 0.05, P < 0.01, and P < 0.05, respectively). CONCLUSION: Myocytic apoptosis is a key mechanism responsible for myocardial damage in viral myocarditis. Anti-FasL antibody can effectively reduce expression of active caspase-3 protein and mRNA, viral replication, cardiomyocytic apoptosis and myocardial injury in the experimental CVB3 myocarditis.

Animals↗
PubMed2004

Mannich-type C-nucleosidations in the 5,8-diaza-7,9-dicarba-purine family.

[structure: see text] C-Nucleosidation with cyclic iminium salts occurring under mild reaction conditions and affording C-nucleosides that are isosteric with N-nucleosides of natural purines is shown to be a consistent property of the entire family of 2,6-(oxo or amino)-disubstituted 5,8-diaza-7,9-dicarba-purines.

Magnetic Resonance Spectroscopy↗
PubMed2004

Inhibitory mechanism of inteferon-gamma on human fibroblasts from Tenon's capsule.

The inhibitory mechanism of interferon-gamma (IFN-gamma) on the fibroblasts from Tenon's capsule was studied. By using immunohistochemical SP method and pathological image system, the inhibitory effects of IFN-gamma on the expression of transforming growth factor beta receptor I in the in vitro cultured fibroblasts from Tenon's capsule were quantitatively analyzed. The results showed that IFN-gamma could reduce the expression of transforming growth factor beta receptor I in the fibroblasts with the following dose-effect relationship: Y = 1937.5-134.2 Igx (r=-0.971, P<0.01). It was concluded that IFN-gamma could inhibit the expression of transforming growth factor beta receptor I in the fibroblasts from Tenon's capsule. The modulation of the transforming growth factor beta receptor I expression by IFN-gamma may be beneficial to the alleviation of the hyperplasia of scar after trabeculectomy.

Conjunctiva↗
PubMed2004

Effect of arsenic trioxide (ATO) on human lung carcinoma PG cell line: ATO induced apoptosis of PG cells and decreased expression of Bcl-2, Pgp.

Arsenic trioxide (ATO) has been established to be an effective agent for treating newly diagnosed and relapsed acute promyelocytic leukemia (APL) patients. Laboratory data suggest that ATO induces apoptosis of hematopoietic or several solid tumor cells. However, to date, its effect on lung carcinoma has not been fully explored. In the present study, we investigated the effect of ATO on human lung carcinoma PG cells in vitro. We found ATO significantly inhibited the proliferation of PG cells in a dose- and time-dependent manner. ATO-induced apoptosis of PG cells was confirmed by the observance of typical morphological changes and detected by the analysis of flow cytometry (FCM). ATO significantly inhibited Bcl-2 and Pgp expression of PG cells by SABC immunohistochemistry and FCM analysis. In conclusion, our findings indicated that ATO induced apoptosis of PG cells and down-regulation of Bcl-2 and Pgp expressions, and these data might provide some theoretical basis for its clinical use in treating lung carcinoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

The opposing effects of endothelin-1 and C-type natriuretic peptide on apoptosis of neonatal rat cardiac myocytes.

C-type natriuretic peptide (CNP) and endothelin-1 are paracrine peptides with opposing effects on cardiac myocyte contraction and intracellular cGMP production. Elevated levels of both endothelin-1 and CNP are found in patients with congestive heart failure. These factors may be related to positive and negative regulation of cell apoptosis in the failing heart. To evaluate the effect of CNP and endothelin-1 on apoptosis of cardiac myocytes and the possible mechanisms involved, primary cardiac myocytes were prepared from neonatal Sabra rats. Cardiomyocyte apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Annexin V in situ staining. The TUNEL method was used to measure the apoptotic index. CNP and the cGMP derivative, 8-br-cGMP, induced apoptosis of cardiac myocytes. CNP-induced apoptosis could be blocked by HS 142-1 (a mixture of 20-30 kinds of linear beta-1, 6-glucan esterified by capronic acid, an antagonist of type A and B natriuretic peptide receptors), and KT 5823 (C29H25N3O5), the inhibitor of cGMP-dependent protein kinase). Alpha-difluoromethylornithine (DFMO), the irreversible inhibitor of ornithine decarboxylase, also induced apoptosis to a similar extent. CNP and 8-br-cGMP caused a marked reduction of intracellular ornithine decarboxylase expression, as determined by Western blot analysis and immunohistochemical assay. Preincubation with endothelin-1 attenuated CNP- and 8-br-cGMP-induced cardiomyocyte apoptosis. Endothelin-1 also antagonized the CNP- and 8-br-cGMP-induced reduction of intracellular ornithine decarboxylase expression. These results suggest that CNP has a proapoptotic effect on neonatal rat cardiac myocytes. The effect is mediated via natriuretic peptide receptors and is due to an elevation of intracellular cGMP, which reduces the expression of intracellular ornithine decarboxylase and probably the production of polyamines. Endothelin-1 protects cardiac myocytes against CNP-induced apoptosis by influencing the cGMP-dependent pathway, and this effect is probably mediated through both a reduction of cGMP and antagonism of the CNP-induced reduction of intracellular ornithine decarboxylase expression.

Animals↗
PubMed2003

2,6-Diamino-5,8-diaza-7,9-dicarba-purine.

[reaction: see text] The title compound, a constitutional isomer of the natural nucleobase 2,6-diaminopurine, undergoes regioselective electrophilic substitutions at carbon C-9.

2-Aminopurine↗
PubMed2003

[Expression of Ki-67 antigen in ameloblastoma and its clinical significance].

OBJECTIVE: The expression of Ki-67 antigen of ameloblastoma was examined in order to investigate the different proliferation activity of histological variants of ameloblastoma and its clinical significance. METHODS: 70 cases of different histological specimen of ameloblastoma were analyzed by immunohistochemical method using Ki-67 antibody. The Label Index was calculated in percentage of Ki-67 positive cells after examined with an image analysis system. RESULTS: The results showed that the Labeled Index in malignant ameloblastoma was the highest 14.72% +/- 2.87%. The Labeled Index in solid ameloblastoma was in the middle, among which the follicular 4.42% +/- 1.05% was higher than the plexiform 3.64% +/- 1.23%. The Labeled Index in mono-cystic ameloblastoma was the lowest 2.21% +/- 1.09%. CONCLUSION: The results demonstrated that the proliferation activity varied according to the histological pattern of ameloblastoma. The prognosis with different proliferation activity was also varied accordingly.

Ameloblastoma↗
PubMed2003

Proanthocyanidin: a natural crosslinking reagent for stabilizing collagen matrices.

While attempting to find a suitable crosslinking reagent for biopolymers, a naturally occurring proanthocyanidin (PA) obtained from grape seeds was selected to fix biological tissues. The cytotoxicity and crosslinking rate, reflected by the in vitro and in vivo degradation of fixed matrices has been studied. The shrinkage temperature of the fixed bovine pericardium increased from 66 to 86 degrees C. A cytotoxicity assay using fibroblast cultures revealed that PA is approximately 120 times less toxic than glutaraldehyde (GA), a currently used tissue stabilizer. In vitro degradation studies showed that fixed tissue was resistant to digestion by bacterial collagenase. Crosslinks between PA and tissues can be stabilized by decreasing the dielectric constant of the solution during storage. After subcutaneous implantation for periods ranging between 3 and 6 weeks, we found no apparent degradation of the GA- or PA-fixed tissues, whereas fresh tissue controls rapidly disintegrated. Beyond 6 weeks PA crosslinks began to degrade. More fibroblasts migrated and proliferated inside the PA-fixed implants compared with GA counterparts. Tissues crosslinked with PA manifested an enhanced collagen expression and deposition and did not calcify after implantation. GA, on the other hand, even after thorough rinsing continued to be cytotoxic, inhibited collagen synthesis and encouraged dystrophic calcification. Collagen matrices crosslinked with PA are expected to be of value in the design of matrices that will encourage cell ingrowth and proliferation, which are temporary in nature, and that are intended to regenerate or replace missing tissues, which can delay the biogradation of collagen. As such they should be of significant value in the emerging field of tissue engineering.

3T3 Cells↗
PubMed2003

Synthesis and hydrolysis of a phenylalanyl adenylate pentacoordinated phosphorane.

Amino acid-nucleotide conjugates have important biological functions and therapeutic applications. For example, aminoacyl adenylates are key intermediates in aminoacyl tRNA synthetase reactions. They may also be involved in the prebiotic synthesis of polypeptides. Finally, various amino acid carbomethoxy aryl phosphoramidates of nucleotide prodrugs may be activated through a mechanism involving a pentacoordinated phosphorane intermediates. In order to understand better the chemistry of these compounds, a phenylalanyl adenylate pentacoodinated phosphorane has been synthesized in 72% yield and its decomposition in aqueous solution studied. Hydrolysis gave 2('),3(')-O-isopropylidene adenosine 5(')-monophosphate, 2('),3(')-O-isopropylidene adenosine, and phenylalanine. The results provide model chemistry for the enzymatic degradation mechanism of antiviral aryl amino acid phosphodiester amidates in cells, which leads to their activation.

Adenosine Monophosphate↗
PubMed2003

Quantitative and sensitive in vitro assay for osteoinductive activity of demineralized bone matrix.

A sensitive, rapid, reliable and quantitative method to check the bone forming potential of demineralized bone matrix (DBM) has been developed. The osteoinductivity of the bone morphogenetic proteins (BMPs), present in DBM, can be measured in vitro using a pluripotent myoblast C2C12 cell line. Alkaline phosphatase activity induced by co-incubation of DBM with C2C12 cells was dose-responsive and corresponds to the amount of active BMPs in DBM. Bone forming potential was simultaneously tested in vivo by implanting DBM intra-muscularly in nude rats. ALP activity induced in C2C12 cells, correlated with bone formation in vivo (r=0.88), determined by alkaline phosphatase activity, mineralization density and histomorphology of the DBM explants. Results from DBM batches, originating from five established Bone Banks, showed good consistency between in vitro and in vivo assays. However, DBM activity varied widely from bank to bank as well as from batch to batch within the same bank.

Alkaline Phosphatase↗
PubMed2003

Cardiovascular effects of natriuretic peptides and their interrelation with endothelin-1.

The natriuretic peptides are a group of structurally related but genetically distinct peptides. Four types of natriuretic peptides have been found thus far: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP) and Dendroaspis natriuretic peptide (DNP). ANP and BNP are secreted mainly from the heart and function as hormones with vasodilatory and natriuretic effects. CNP originates mainly from endothelial cells with a paracrine effect to induce vasodilation. Other effects of natriuretic peptides including negative inotropy, antimitogenic and anticoagulation have been described. Three types of natriuretic peptide receptors mediate their functions, and among them two are cGMP-coupled. Clearance of natriuretic peptides is via its clearance receptor through the action of neutral endopeptidases. Natriuretic peptides interact with other vasoactive peptides including endothelin. The putative role of natriuretic peptides in the pathophysiology of various cardiovascular diseases including congestive heart failure, hypertension, ischemic heart disease, and cardiomyopathy are discussed. Natriuretic peptide plasma levels are used for the diagnosis and therapeutic follow-up of congestive heart failure patients. Increasing the levels of natriuretic peptides by natriuretic peptide mimetics and neutral endopeptidase inhibitors may provide a new therapeutic strategy for the treatment of cardiovascular diseases such as congestive heart failure and hypertension.

Animals↗
PubMed2003

Combined effects of phosphatidylcholine and demineralized bone matrix on bone induction.

The osteoinductivity of demineralized bone matrix (DBM) becomes significantly reduced if the specimens are further delipidated with chloroform-methanol. The addition of phosphatidylcholine (PC), a major constituent of the lipid fraction present in the calcification front during normal bone formation, can restore the biological activity. Active endochondral bone formation is observed in the DBM/PC implants placed in the anterior abdominal wall musculature or subcutaneously for 28 days. When PC is added to generate a putty containing 60% PC and 40% DBM, biochemical parameters associated with osteoinductivity are significantly enhanced. Biological responses evaluated histologically and by determination of alkaline phosphatase activity are in very good agreement. The DBM/PC putty has good handling properties, can be molded into different shapes, and does not wash away from the application site. An advantage of adding PC is that it not only enhances the handling properties, but also boosts the osteoinductivity of the preparation.

Alkaline Phosphatase↗