Biomedical subjects

Bin Liu

Publications and source records attributed to Bin Liu.

301 records · Page 17Linked to original sources

PubMed2002

[Microencapsulation of immortalized mandibular condylar chondrocytes].

To explore the possibility of microencapsulation of chondrocytes in cartilage tissue engineering, immortalized manibular condylar chondrocytes (IMCCs) were microencapsuled by Alginate-polylysine-alginate (APA) method, according to air pressure shearing model. Phase contrast microscopy, trypan blue staining exclusion, cell number counting, HE staining and immunohistochemistry method were used to observe the morphology of the microencapsules, the growth character of cells, cartilage characteristics, and so on. The results showed that IMCC could survive and grow in microencapsule, and the viability rate of cells is more than 80 per cent. The diameter of microcapsule is 779 microns in average. The number of cell increased with time, and cells went into platform in about 20 days. Cells grew in clusters and cartilage specific proteoglycans and type II collagen were highly expressed. It was concluded that IMCC could form cartilage-like tissue within microencapsulation, implying that microencapsule technique might be applicable to cartilage tissue engineering.

Alginates↗

PubMed2002

[Transfection of the exogenous PTEN-induced growth inhibition of the highly metastatic mucoepidermoid carcinoma cell line M3SP2 in vitro].

OBJECTIVE: The purpose of this study was to evaluate the effects of the exogenous phosphatase and tensin homology deleted on chromosome 10 (PTEN) gene on in vitro growth of the highly metastatic mucoepidemoid carcinoma cell line M3SP2. METHODS: The growth of the exogenous PTEN transfected mucoepidemoid carcinoma cells M3SP2-PTEN gene was studied by analyzing cell growth curves, mitosis index and clone formation efficiency and compared with its parental cell line M3SP2 and the vector pBabepuro-transfected cell line M3SP2-pBp. RESULTS: The doubling time (h) of M3SP2, M3SP2-pBp and M3SP2-PTEN were 24.50, 24.76 and 31.74; the mitosis index (@1000) were 53.0 +/- 6.20, 49.0 +/- 5.24 and 16.2 +/- 3.2; the clone formation efficiency (%) were 37.37, 35.01 and 10.40, respectively. The M3SP2-PTEN cells also revealed 57.05%-71.46% inhibition of growth from day 3 to 7 and 65%-72% inhibition of clone formation compared with the parental cells. CONCLUSION: These data provide evidence that the exogenous wild-type PTEN have remarkably inhibitory effects on in vitro proliferation of the highly metastatic mucoepidermoid carcinoma cell line M3SP2.

Carcinoma, Mucoepidermoid↗

PubMed2002

[A clinical study of reflux oesophagites].

OBJECTIVE: To study the incidence and role of acid and bile reflux in gastroesophageal reflux disease (GERD). METHODS: Fifty two patients with reflux symptoms were studied. All of them were performed endoscopy received acid and bile reflux monitoring. RESULTS: Fifty two patients received acid and bile reflux monitoring, 42 patients had reflux with the main type of double-reflux (both acid and bile reflux) which was 59.5% (25/42), and with the type of the single-reflux which was 40.5% (17/42). Among single-reflux, the acid reflux was the main type about 76.4% (13/17); Among double-reflux, the degree of acid reflux was more severe, than did bile reflux; The percent of reflux oesophagites join the double-reflux patients was significant high than that in single-acid-reflux patients (P < 0.05); There was a liner correlation between acid reflux index either the frequency or the severity of reflux symptoms. CONCLUSIONS: Double-reflux was the main type of reflux in GERD, and acid reflux was the main type among double-reflux and single-reflux. There may be a synergistic effect between acid and bile reflux. Acid reflux was the main factor for reflux symptoms.

Bile Reflux↗

PubMed2002

[Clinical features of gastroesophageal reflux disease in geriatric patients].

OBJECTIVE: To evaluate the features of gastroesophageal reflux disease (GERD) in elderly patients. METHODS: 72 patients with GERD were investigated for the history of illness and the results of gastroscopy and 24 hours esophageal bile monitoring of 54 patients were simultaneously randomized to undergo ambulatory pH monitoring. The degrees of esophagitis were graded according to endoscopic findings. RESULTS: Obesity was found in 48% of the elderly group (more than 65 years old) and 49% of the control group (less than 65 years old). There were longer acid and bile reflux time and higher frequency (65%) of hiatal hernia in the elderly, and more patients (35%) had complicated severe grade esophagitis. There were longer time of bile reflux and the higher incidence (76%) of both acid and bile reflux in elderly group than in control group (P < 0.05). But the acid reflux time (%) was similar in two groups (P > 0.05). CONCLUSIONS: The GERD in elderly patients may be associated with obesity and hiatal hernia. The features of elderly GERD patients are high frequency of erosive esophagitis, and high frequency of both acid and bile reflux, as well as longer history of bile reflux time.

Age Factors↗

PubMed2002

Neural invasion in pancreatic carcinoma.

BACKGROUND: Neural invasion is a special metastatic route in pancreatic cancer and responsible for the high recurrence in curatively resected cases. OBJECTIVE: To summarize the characteristics and mechanisms of neural invasion in pancreatic carcinoma for the better treatment of this disease. DATA SOURCES: The international literatures were reviewed about the definition, incidence and mechanisms of neural invasion and its clinicopathology, diagnosis and treatment. DATA SYNTHESIS: Neural invasion is defined when the medial perineurium is involved by cancer cells, accounting for 45%-100% of all cases. It can be divided into different kinds or stages according to its locations and the number of nerve fascicles involved. Invasion along vascularity, lymphatic vessels, perineural space and neurotropism is considered as its primary mechanisms. No clinicopathologic factors are correlated with neural invasion. Intravascular ultrasound, CT scan and immunostaining K-ras gene analysis can be used to diagnose neural invasion pre-, intra- or postoperatively. CONCLUSION: Neural invasion is an important prognostic factor for the recurrence of pancreatic carcinoma after pancreatectomy. Because of its high incidence, pancreatectomy with extended radical retroperitoneal dissection should be considered as a basic procedure in the treatment of pancreatic carcinoma.

Carcinoma↗

PubMed2002

[Transformation of Populus tomentosa with anti-PLD gene].

Antisense Phospholipase Dgamma( PLDgamma) gene was introduced into Populus tomentosa mediated by Agrobactrium tumefaciens. The young leaves of triploid populus were used as the material and the regeneration system of high frequency has been established. We have developed the traditional transgene method by Agrobactrium trmefaciens and obtained many transgenic plants of anti-PLDgamma gene. Tests showed that the transgenic plants can grow well on the culture medium with 0.7% NaCl.

English Abstract↗

PubMed2001

NM23-H1 and NM23-H2 repress transcriptional activities of nuclease-hypersensitive elements in the platelet-derived growth factor-A promoter.

The platelet-derived growth factor (PDGF)-A promoter is regulated by a number of GC-rich regulatory elements that possess non-B-form DNA structures. Screening of a HeLa cDNA expression library with the C-rich strand of a PDGF-A silencer sequence (5'-S1 nuclease-hypersensitive site (SHS)) yielded three cDNA clones encoding NM23-H1, a protein implicated as a suppressor of metastasis in melanoma and breast carcinoma. Recombinant human NM23-H1 cleaved within the 3'-portions of both 5'-SHS strands in either single-stranded or duplex forms. In contrast, NM23-H2, known as a transcriptional activator with a DNA cleavage function, cleaved within the 5'-portions of both strands, revealing that NM23-H1 and NM23-H2 cleave at distinct sites of the 5'-SHS and by different mechanisms. NM23-H1 and NM23-H2 also cleaved within the PDGF-A basal promoter region, again exhibiting preferences for cleavage within the 5'- and 3'-portions of the element, respectively. Transient transfection analyses in HepG2 cells revealed that both NM23-H1 and -H2 repressed transcriptional activity driven by the PDGF-A basal promoter (-82 to +8). Activity of the negative regulatory region (-1853 to -883), which contains the 5'-SHS, was also inhibited modestly by NM23-H1 and NM23-H2. These studies demonstrate for the first time that NM23-H1 interacts both structurally and functionally with DNA. They also indicate a role for NM23 proteins in repressing transcription of a growth factor oncogene, providing a possible molecular mechanism to explain their metastasis-suppressing effects.

Antigens, Neoplasm↗

PubMed2001

Photochromic Inorganic/Organic Self-Assembled Superlattice Films.

Phosphotungstic acid (PW(12)) and 1,10-diaminodecane (1,10-DAD) molecules have been alternatively assembled on 3-aminopropyltriethyoxysilane modified quartz or silicon substrate to form multicomposite mutilayer thin films by the molecular deposition technique. Thus-obtained films were characterized by UV-visible, XRD, X-ray reflection (XRR), and XPS spectra. Results show that the layer-by-layer self-assembly of PW(12) and 1,10-DAD leads to a well-ordered superlattice-layered structure with a d-spacing of 3.19 nm, which exhibits extremely exciting photochromic properties. Based on the experimental data, a presumable interlayer structural model has also been suggested. Copyright 2001 Academic Press.

Journal Article↗

PubMed2001

[Variant Frequency of Erythrocyte Glycophorin A in Persons Accidentally Irradiated by (60)Co Source]

Glycophorin A (GPA) is one of the important molecular markers in studies of somatic cell mutations. To investigate the relationship between the gamma-irradiation and the frequency of GPA variation, the frequency of variant erythrocytes at the GPA locus was determined in peripheral blood of 3 subjects with accidental whole-body gamma-irradiation. The biological dose of individuals was 2.5, 2.9 and 1.9 Gy estimated by the chromosome aberration assay, respectively, and the frequency of GPA variation was 3.9, 4.3 and 4.1 times greater than that from normal controls, respectively. Our results suggest that the variant frequency of erythrocyte GPA was increased. On account of the GPA gene mutations are preserved in hematopoietic stem cells during all irradiated individual's life, the frequency of GPA variation could be used as a permanent marker for mutagenesis of radiation.

Journal Article↗

PubMed1997

Characterization and Identification of Recombinant [B18Ile] Human Insulin.

Recombinant [B18Ile] human insulin was obtained from a mutant [B18Ile] PIP purified by transpeptidation. [B18Ile] human insulin can be crystallized and has 82% of receptor binding activity as that of porcine insulin and retains almost the same level of in vivo biological activity comparing with porcine insulin. It is proposed that the B18Val residue may not be involved in the expression of insulin activity.

Journal Article↗

PubMed1996

Protein Engineering of Insulin: [B9Glu, B10Asp] Human Insulin.

B9Ser and B10His of the insulin B chain are substituted respectively by Glu and Asp using a gapped duplex DNA approach for site-directed mutagenesis. A mutant insulin-[B9Glu, B10Asp] human insulin was obtained. The receptor binding capacity of the mutant insulin is 34.4% as that of porcine insulin. However, the in vivo biological activity of [B9Glu, B10Asp] human insulin is almost as the same as that of porcine insulin.

Journal Article↗

PubMed1996

Protein Engineering of Insulin: [B9 Glutamic Acid] Human Insulin.

B9Ser of insulin B chain was substituted by Glu using site-directed mutagenesis to obtain a fast-acting insulin-[B9Glu] human insulin. The receptor binding capacity and in vivo biological activity of [B9Glu] human insulin are 21% and 40% as those of porcine insulin respectively.

Journal Article↗

PubMedDate not supplied

The fluorescence sensor for saccharide based on internal conversion.

In this paper, an internal conversion (IC) fluorescence probe N-(o-boronic acid)benzyl-1-naphthylamine (BBNA) was prepared from 1-naphthylamine and 2-formylbenzeneboronic acid. The fluorescence parameters of BBNA were investigated in a variety of solvents. When BBNA interacted with D-fructose in phosphate buffer solution of 30% MeOH, pH 8.21 (v/v), the fluorescence intensity increased and emission maximum red-shifted slightly with increasing D-fructose concentration. In the presence of D-fructose, the fluorescence quantum yield of BBNA increased with increasing solvent polarity, suggesting that internal conversion (IC) occurred with BBNA. The binding force of BBNA with d-fructose was the strongest, and the stability constant (K) of D-fructose was 99.9 mol/L. Therefore, a selective recognition system based on IC was constructed for D-fructose.

1-Naphthylamine↗