Biomedical subjects

Bin Liu

Publications and source records attributed to Bin Liu.

At least 91 records · Page 5Linked to original sources

PubMed2006

[Intratympanic dexamethasone injections for intractable sudden sensorineural hearing loss].

OBJECTIVE: To investigate the efficacy of intratympanic dexamethasone injection (IDI) for 23 patients with intractable sudden sensorineural hearing loss (SSNHL). METHOD: Dexamethasone (5 g/ml) was injected into the middle ear. The injection was repeated once two days and had a total of 4 doses (10 mg). RESULT: The 23 patients were followed up for one month. Eight of 23 patients (34.8%) demonstrated a 17 to approximately 54 dB improvement in PTA and 15 of 23 (65.2%) had no response. CONCLUSION: IDI is a simple and effective treatment for SSNHL patient who had not responded to conventional therapy, although hearing was rarely improved to normal levels.

Adult↗

PubMed2006

[Remaining laryngeal flap reconstruction of the hypopharynx in pyriform sinus carcinoma resection].

OBJECTIVE: To discuss the feasibility of using remaining laryngeal flap to reconstruct the hypopharyngeal defect in pyriform sinus carcinoma resection. METHOD: Seven patients with pyriform sinus carcinoma to reconstruct hypopharyngeal defect with remaining laryngeal flap were summarized. Half the hypopharynx and half the larynx were resected and unaffected half the larynx was reserved. On the unaffected side, thyroid, cricoid and arytenoid cartilages were removed and inner perichondrium was reserved. A 4.0 cm x 2.0 cm laryngeal flap was made with a broad base on the base of tongue. Subhyoid muscles on unaffected side were reserved and superior laryngeal artery should not be injuries. The food canal was reconstructed with the pulled-down mucosa of the base of the tongue, the unaffected half of the larynx and the remnant hypopharyngeal mucosa. Postoperative radiation (60 Gy) was undertaken. RESULT: Six cases healed normally. Local infection and pharyngeal fistula were found in one case and cured in two weeks. No hypopharyngeal stenosis was observed. Through three to five years follow-up of the seven patients, three died in three years and one died in four years. CONCLUSION: To the selected cases with pyriform sinus carcinoma, reconstruction of hypopharyngeal defect with laryngeal flap is simple and safe. The injury is relatively small and complications are not severe. In the case sufficient blood supply is insured, firm suture is the key point to prevent pharyngeal fistula.

Aged↗

PubMed2006

[Constituents in the alkaloid fraction of Kushen decoction].

OBJECTIVE: To study the chemical constituents of the alkaloid fraction of Kushen decoction. METHOD: Constituents were isolated by different kinds of column chromatography and their structures were elucidated with spectral methods. RESULT: Eight compounds were isolated and identified as matrine (I), sophoridine (II), sophocarpine (III), sophoramine (IV), oxymatrine (V), oxysophocarpine (VI), aloperine (VII) and sparteine (VIII). CONCLUSION: All these compounds were isolated from Kushen decoction for the first time. Aloperine was found firstly in Sophora flavescens, or Scutellaria baicalensis, or Rehmannia glutinosa which constituted Kushen decoction.

Alkaloids↗

PubMed2006

[Analysis of differential protein expression profile between retinoic acid resistant and sensitive acute promyelocytic leukemia cells].

BACKGROUND & OBJECTIVE: This study was to compare the protein expression profiles between retinoic acid (RA) resistant and sensitive acute promyelocytic leukemia (APL) cells by proteomic research method. METHODS: Total cellular proteins extracted from a RA sensitive cell line NB4 and a RA resistant cell line MR2 were separated by two-dimensional (2D) polyacrylamide gel electrophoresis (PAGE). High quality 2D-PAGE protein profiles were obtained and analyzed by PDQuest v7.1 analysis software to screen differentially expressed protein spots. Those sports were identified by mass spectrometry. RESULTS: 2-DE patterns of APL cell lines with high-resolution and reproducibility were obtained. The average spots for MR2 and NB4 cells were 890+/-45 and 912+/-56, respectively. 57 significantly differentially expressed protein spots were screened, among which 23 protein spots were identified to be up-regulated and 34 down-regulated in MR2 cells compared with NB4 cells. Ten proteins were identified by mass spectrometry, with a successful identification rate of 70%. The identified proteins could be classified into different categories: oncogenes,cell cycle regulator and signal transducer. CONCLUSION: The utilization of 2D-PAGE is effective in identifying the protein expression profiles between RA resistant and sensitive APL cells, therefore this study may provide a novel clue to elucidate the drug resistant mechanisms of all-trans retinoic acid.

Antineoplastic Agents↗

PubMed2006

Extracapsular spread in ipsilateral neck metastasis: an important prognostic factor in laryngeal cancer.

OBJECTIVE: To evaluate the impact of extracapsular spread (ECS) in ipsilateral neck metastasis on prognosis and its related factors in laryngeal cancer. METHODS: The study included 184 patients who underwent laryngectomy and simultaneous radical or modified radical neck dissection between January 1994 and December 1997 for laryngeal cancer. All of them had a complete 5-year follow-up. We used transparent lymph node detection and continuous slicing method on all neck dissection specimens. Kaplan-Meier model was used for survival analysis and the log-rank test was used to assess significance. RESULTS: We found pathological neck metastases in 80 patients. Among them, 26 cases (32.5%) had ECS in ipsilateral neck. ECS incidence increased with advanced pathological N (pN) stages (pN1 3.7%, pN2a 25.0%, pN2b 50.0%, and pN2c 55.6%; P = 0.001). ECS incidence also increased with number of positive nodes (1 positive node 8.6%, 2 positive nodes 33.3%, 3 and more positive nodes 66.7%; P < 0.001). Incidences of contralateral neck metastases and ipsilateral neck recurrence in patients with ECS were higher than those in patients without ECS (46.2% vs. 24.1%, P = 0.046; 34.6% vs. 7.4%, P = 0.002). The 5-year survival rate of patients with ECS was significantly lower than that of patients without ECS (23.1% vs. 57.4%, P = 0.013). CONCLUSION: ECS is an important prognostic factor in laryngeal cancer. Patients with ECS have a higher incidence of contralateral neck metastasis, so bilateral neck dissection should be selected.

Adult↗

PubMed2005

Semiconductor rings fabricated by self-assembly of nanocrystals.

Three types of nonlinear organization schemes for creating ringlike semiconductors have been elucidated with the self-assembly of nanocrystals in aqueous phase under one-pot conditions. The synthetic architecture is based on morphological controls of primary nanocrystals which possess an intrinsic hexagonal symmetry. As most semiconducting materials have similar hexagonal (or cubic) crystal symmetries, in principle, the self-assembling processes revealed in this work should be extendable to other semiconductor nanocrystals.

Journal Article↗

PubMed2005

Ordered alignment of CdS nanocrystals on MWCNTs without surface modification.

This paper describes a facile hydrothermal procedure capable of aligning CdS nanocrystals on multiwalled carbon nanotubes (MWCNTs) without the use of organic bridging molecules such as cysteamine and carboxylates. The direct placement of CdS on MWCNTs allows good mixing and better interfacing between the two nanophases. The synthesis conditions can in principle be tuned to produce modulations in compositions, phases, and crystal orientations to the need of optoelectronic and photonic applications.

Journal Article↗

PubMed2005

[Duraplasty with Neuropatch versus autologous fascia lata for Chiari I malformation with syringomyelia: a comparative study].

OBJECTIVE: To evaluate the outcome and postoperative reaction of dural substitute (Neuropatch) applying in the treatment of Chiari I malformation(CMI) associated with syringomyelia(SM). METHODS: Forty patients of CMI associated with SM were operated in our department from Jul. 2002 to Jul. 2004. All patients underwent posterior cranial fossa decompression and duraplasty. They were divided into two groups, 20 patients being repaired with Neuropatch (Neuropatch group), and the others with autologous fascia lata (fascia group). There were 6 males and 14 females in Neuropatch group and 10 males and 10 females in fascia group. The operations were performed under general anesthesia via suboccipital approach and the extent of posterior cranial fossa decompression ranged from 20 cm(2) (5 cmx4 cm) to 35 cm(2) (5 cmx7 cm). The removal of posterior arch of atlas depended on the extent of tonsillar herniation, and the dura was opened in Y shape. The Neuropatch was cut into triangular shape, and the same sized autologous fascia lata was used in fascia group. The patches were sutured tightly to the dura matter in each group. The incision was closed layer by layer and drainage was used, if necessary. Antibiotics and hormone were routinely used. The duration of operation, postoperative fever were evaluated, the outcome of the operation was evaluated by Tator scale, and the data were analyzed with statistic software SPSS 10.0. RESULTS: There were12 patients (60%) who suffered from postoperative fever in the Neuropatch group, and 9 patients (45%) in the fascia group(chi(2)=0.902,P=0.342). Seventeen patients in each group were improved postoperatively. The duration of operation, postoperative fever and antibiotics used were compared between the two groups. No significant difference was found, but the duration of postoperative fever and the time of hormone used were different. There were no postoperative infections that occurred after the follow up for 1 to 2 years, except for one patient in fascia group who developed infective granuloma and recovered later by treatment. CONCLUSION: Neuropatch is a useful dural substitute for the repair of dural defects in the treatment of CMI associated with syringomyelia.

Arnold-Chiari Malformation↗

PubMed2005

Characterization of transferrin receptor-dependent GaC-Tf-FeN transport in human leukemic HL60 cells.

BACKGROUND: Understanding the uptake of GaC-Tf-FeN by cells will provide key insights into studies on transferrin-mediated drug delivery. METHODS: The mechanism of GaC-Tf-FeN transporting into and out of HL60 cells has been investigated by comparing transports between GaC-Tf-FeN and apoTf by means of 125I-labeled transferrin. RESULTS: An association constant for GaC-Tf-FeN was 2 times that for apoTf. GaC-Tf-FeN and apoTf of cell surface-bound displayed similar kinetics during the uptake, but the release rates of internalized GaC-Tf-FeN and apoTf from cells were different which showed characteristic disparate. The release continued to occur during the incubation of GaC-Tf-FeN in the presence of nonradioactive apoTf. Neither NaN3 nor NH4Cl could completely block internalization of GaC-Tf-FeN, but they prevented the release of GaC-Tf-FeN from the cells. Excess cold unlabeled apoTf could overcome the block in the release due to NH4Cl but not NaN3. The binding and internalization of GaC-Tf-FeN could be competitively inhibited by nonradioactive apoTf. It implies that both bind to the same receptor on the membrane and the localization of GaC-Tf-FeN resembles that of apoTf inside cells. Pretreated cells with pronase abolished the binding of GaC-Tf-FeN significantly. CONCLUSION: On the basis of these findings, we proposed the "transferrin receptor" for the mechanism of GaC-Tf-FeN transport by HL60 cells.

Ammonium Chloride↗

PubMed2005

Chemiluminescence of CdTe nanocrystals induced by direct chemical oxidation and its size-dependent and surfactant-sensitized effect.

CdTe nanocrystals (NCs) capped with thioglycolic acid (TGA) were synthesized via a microwave-assisted method. The chemiluminescence (CL) of CdTe NCs induced by directly chemical oxidation and its size-depended and surfactant-sensitized effect in aqueous solution were then investigated. It was found that oxidants, especially hydrogen peroxide and potassium permanganate, could directly oxidize CdTe NCs to produce strong CL emission in basic conditions. The oxidized CL of CdTe NCs displayed size-dependent effect and its intensity increased along with increasing the sizes of the NCs. Moreover, the CL intensity could, if surfactants CTAB or beta-cyclodextrin were added to the above CL system, be sensitized to some degree. The sensitized CL induced by CTAB and beta-cyclodextrin is mainly contributing to the formation of aggregate nanostructure and the micellar micronanoenvironment, respectively. The possible oxidized CL mechanisms were further examined by means of photoluminescence spectra, CL spectra, and transmission electron microscopy studies. The CL properties of CdTe NCs not only will be helpful to study physical chemistry properties of semiconductor nanocrystals but also are expected to find use in many fields such as luminescence devices, bioanalysis, and multicolor labeling probes.

Journal Article↗

PubMed2005

Construction and application of a yeast surface-displayed human cDNA library to identify post-translational modification-dependent protein-protein interactions.

Although post-translational modifications such as phosphorylation mediate fundamental biological processes within the cell, relatively few methods exist that allow proteome-wide identification of proteins that interact with these modifications. We constructed a yeast surface-displayed human cDNA library and utilized it to identify protein fragments with affinity for phosphorylated peptides derived from the major tyrosine autophosphorylation sites of the epidermal growth factor receptor or focal adhesion kinase. We identified cDNAs encoding the Src homology 2 domains from adapter protein APS, phosphoinositide 3-kinase regulatory subunit 3, SH2B, and tensin, demonstrating the effectiveness of this approach. Our results suggest that large libraries of functional human protein fragments can be efficiently displayed on the yeast surface. In addition to the analysis of post-translational modifications, yeast surface-displayed human cDNA libraries have many potential applications, including identifying targets and defining potential cross-reactive proteins for small molecules or drugs.

Adult↗

PubMed2005

Synthesis and herbicidal evaluation of novel 3-[(alpha-hydroxy-substituted)benzylidene]pyrrolidine-2,4-diones.

A series of 3-[(alpha-hydroxy-substituted) benzylidene]pyrrolidine-2,4-dione derivatives were synthesized as candidate herbicides by reacting different aroyl acetates with N-substituted glycine esters. The new compounds were identified by 1H NMR spectroscopy and elemental analyses. Their herbicidal activities were evaluated. Some compounds exhibited excellent herbicidal activities at a dose of 187.5 g/ha. A suitable electron-donating substituent at the 2- and/or 4-position of the phenyl ring was essential for high herbicidal activity, a result that has not been reported before. It was also found that the title compound's structure-activity relationships were different from those of other similar kinds of earlier compounds, a result that may depend on the enol structure difference.

4-Hydroxyphenylpyruvate Dioxygenase↗

PubMed2005

Isolation, structure elucidation, antioxidative and immunomodulatory properties of two novel dihydrocoumarins from Aloe vera.

Two new dihydrocoumarin derivatives, compounds 1 and 2, were isolated from Aloe vera. Their structures were determined by X-ray crystallographic diffraction analysis and extensive 1D, 2D NMR spectroscopic data. Both of them evidently showed antioxidant activity against superoxide and hydroxyl radicals. Only 1 obviously exhibited immunomodulatory activity in relation to increasing the phagocytic activity and stimulating the production of superoxide anions in the oxygen respiratory burst of rat peritoneal macrophages.

Aloe↗

PubMed2005

Molecular markers for detection of pathogenic Escherichia coli strains belonging to serogroups O 138 and O 139.

Escherichia coli strains belonging to O-serogroup 138 and 139 are important as disease agents in pigs causing post-weaning diarrhea and edema disease. Several types of shiga toxin-producing O 138 and O 139 strains were isolated from diarrheic humans and from cattle and food of bovine origin. Serotyping is the current method for detection of O 138 and O 139 strains but its applicability can be limited due to the presence of capsules and capsular-like bacterial surface antigens and in the case of rough LPS. To overcome these difficulties for diagnosis, we have developed a specific PCR method suitable for detection of different types of O 138 and O 139 strains. The O-antigen gene clusters of E. coli O 138 and O 139 type strains were sequenced, and the genes were identified on the basis of homology. By screening against 186 E. coli and Shigella type strains, two genes specific to each of E. coli O 138 and O 139 were identified, respectively, and were tested on 15 clinical and environmental isolates of those two serogroups in a double-blind test. The sensitivity of the PCR assays was determined, and the detection limits were 2 pg per mul of chromosomal DNA and 2 CFU per 10 g of water or pork samples. PCR-based detection of O-antigen specific genes of E. coli O 138 and O 139 was shown to be accurate, highly sensitive and rapid, and is suggested as a new diagnostic tool for investigations of infections and outbreaks with these strains in animals and humans and for control of food.

Animals↗

PubMed2005

Design and synthesis of heterocyclic malonyl-CoA decarboxylase inhibitors.

We have previously reported the discovery of small molecule inhibitors of malonyl-CoA decarboxylase (MCD) as novel metabolic modulators, which inhibited fatty acid oxidation and consequently increased the glucose oxidation rates in the isolated working rat hearts. MCD inhibitors were also shown to improve cardiac efficiency in rat and pig demand-induced ischemic models through the mechanism-based modulation of energy metabolism. Herein, we describe the design and synthesis of a series of novel heterocyclic MCD inhibitors with a preference for substituted imidazole and isoxazole.

Animals↗

PubMed2005

Solvent effects on the two-photon absorption of distyrylbenzene chromophores.

A series of organic- and water-soluble distyrylbenzene-based two-photon absorption (TPA) fluorophores containing dialkylamino donor groups at the termini was designed, synthesized, and characterized. The central core was systematically substituted to modulate intramolecular charge transfer (ICT). These molecules allow an examination of solvent effects on the TPA cross section (delta) and on the TPA action cross section. In toluene, the delta values follow the order of ICT strength. The effect of solvent on delta is nonmonotonic: maximum delta was measured in an intermediate polarity solvent (THF) and was lowest in water. We failed to find a correlation between the observed solvent effect and previous theoretical predictions. Hydrogen bonding to the donor groups and aggregation of the optical units in water, which are not included in calculational analysis, may be responsible for the discrepancies between experimental results and theory.

Absorption↗

PubMed2005

Silencing of human phosphatidylethanolamine-binding protein 4 sensitizes breast cancer cells to tumor necrosis factor-alpha-induced apoptosis and cell growth arrest.

PURPOSE: The current therapeutic approach is not so effective in breast cancer patients. Alternative treatment protocols aimed at different targets need to be explored. We recently reported a novel phosphatidylethanolamine-binding protein, human phosphatidylethanolamine-binding protein 4 (hPEBP4), as an antiapoptotic molecule. The finding led us to explore a promising approach for breast cancer therapy via silencing the expression of hPEBP4. EXPERIMENTAL DESIGN: hPEBP4 expression in clinical breast specimens was examined by Tissue Microarrays. RNA interference was used to silence hPEBP4 expression in MCF-7 breast carcinoma cells and the effects on cell proliferation, cell cycle progression, apoptosis, as well as underlying mechanisms, were investigated. RESULTS: hPEBP4 was found to be expressed in up to 50% of breast cancers but in only <4% of normal breast tissues. Silencing of hPEBP4 potentiated tumor necrosis factor-alpha (TNF-alpha)-induced apoptosis and cell cycle arrest in MCF-7 cells, which was due to the increased mitogen-activated protein kinase activation and the enhanced phosphatidylethanolamine externalization. Further investigation showed that silencing of hPEBP4 in MCF-7 cells promoted TNF-alpha-induced stability of p53, up-regulation of phospho-p53ser15, p21waf/cip, and Bax, and down-regulation of Bcl-2 and Bcl-xL, which were shown to depend on extracellular signal-regulated kinase 1/2 and c-jun NH2-terminal kinase activation by hPEBP4 silencing. Moreover, the increased proportion of cells in the G0-G1 phase of cell cycle was observed in hPEBP4-silenced MCF-7 cells on TNF-alpha treatment and the expression of cyclin A and cyclin E was down-regulated more significantly. CONCLUSIONS: The antiapoptotic effect and the preferential expression pattern in breast cancer tissues make hPEBP4 a new target for breast cancer therapy. Silencing of hPEBP4 expression may be a promising approach for the treatment of breast carcinoma.

Apoptosis↗

PubMed2005

Mixed-valent diruthenium diphosphonate with kagomé structure.

This paper reports the first example of diruthenium phosphonate with kagomé structure, namely, [NH3(CH2)4NH3][Ru2(hedpH(0.5))2].2H2O (hedp = 1-hydroxyethylidenediphosphonate). The compound contains kagomé layers that are linked by very strong hydrogen bonds into a nanoscale kagomé structure. Ferromagnetic interactions are mediated between the paramagnetic diruthenium units.

Journal Article↗