Biomedical subjects

Bin Li

Publications and source records attributed to Bin Li.

At least 109 records · Page 6Linked to original sources

PubMed2006

Treatment of chronic osteomyelitis with one-stage allograft.

OBJECTIVE: To avoid disadvantages of two-stage cancellus bone autograft, we investigated the feasibility of one-stage allograft for reconstructing the bone defect resulting from debridement of chronic osteomyelitis in limbs. METHODS: Between Feb. 1999 and Apr. 2004, 35 cases of chronic osteomyelitis (8 cases of nonunion) underwent one-stage allograft after debridement in our hospital. RESULTS: Thirty-five cases were followed up for an average period of 28 months (range, 13 to 55 months), in which 32 cases (91.43%) were found no infection, and 3 cases (8.57%) were confirmed recurrence of infection. Four out of 8 cases of bone nonunion healed in 9.5 months on average (range, 3 to 12 months), and another case also acquired union after redebridement and autograft of ilium due to infection recurrence 35 days after surgery. Renonunion occurred in 3 cases, 2 out of whom healed after secondary operation with autograft. One case of renonunion and 2 cases of infection recurrence refused further treatment. CONCLUSIONS: A high rate of infection arrest can be attained when one-stage allograft is used to reconstruct the bone defect of chronic osteomyelitis after debridement in limbs. Therefore, chronic osteomyelitis should not be regarded as a contraindication to one-stage allogeneic bone grafting. Renonuion, however, achieves a relatively high rate, especially in cases of segmental bone defect.

Adolescent↗

PubMed2006

[The effects of matrine on cell proliferation and telomerase activity in retinoblastoma cells in vitro].

OBJECTIVE: To evaluate the effects of matrine on cell proliferation and telomerase activity in retinoblastoma cells in vitro. METHODS: HXO-Rb44 cells were treated with 0.1 to 3.2 mmol/L matrine for 24 h, then cell viability was measured by MTT assay. Apoptosis rates were evaluated by flow cytometry and TUNEL assay after the cells were treated for various durations. The telomerase activity were measured by telomeric repeat amplification protocol. RESULTS: MA inhibited the growth of HXO-Rb44 cells. Ma induced the apoptosis and down-regulated the telomerase activity of HXO-Rb44 cells, which were time dependent. There was a positive correlation between the telomerase activity and the apoptosis (r = -0.961, P < 0.01). CONCLUSIONS: Ma can induce the apoptosis and down-regulate the telomerase activity of retinoblastoma cells, which may be one of important mechanisms to inhibit the cell proliferation. It suggests that Ma may be a potent drug for the treatment of retinoblastoma.

Alkaloids↗

PubMed2006

[The value of thoracoscopy for diagnosis and management of refractory hepatic hydrothorax].

OBJECTIVE: To study the value of thoracoscopy for diagnosis and management of refractory hepatic hydrothorax (HH). METHODS: Twenty-six patients with refractory HH were enrolled in this study. Twenty-four of them underwent therapeutic thoracoscopy to achieve pleurodesis by application of talc poudrage. RESULTS: Nineteen of the 26 patients had dilated chest wall veins, 6 had dilated azygos veins, and 16 had diaphragm blebs. Of the 24 patients who received pleurodesis via thoracoscope, 14 cases showed complete response, and 8 showed partial response. Mild chest pain and temperature elevation were the most complaints during or after the procedure. Liver function abnormalities were the most serious side effects after pleurodesis. During the follow-up period ranging from 6 months to 3 years, 1 patient died of upper gastrointestinal hemorrhage and encephalopathy in 1 month, 3 patients died of hemorrhage in 6, 12, 18 months respectively, and 1 case experienced recurrence in 18 months. CONCLUSIONS: Defects in the diaphragm seemed to be the main cause for the development of HH. Pleurodesis achieved by thoracoscopy and talc poudrage was effective in the treatment of HH, but complications and impaired liver functions should be considered.

Adult↗

PubMed2006

[Lymphatic mapping and parametrial lymph nodes identification in patients with early stage cervical cancer].

OBJECTIVE: To determine the presence, distribution, and metastasis incidence of parametrial lymph nodes (PLN) of patients with cervical cancer and to investigate the role of lymphatic mapping and topographic section in PLN identification. METHODS: Sixty patients with early stage (Ib-IIa) cervical cancer undergoing radical hysterectomy and pelvic lymphadenectomy were included in the study. Before surgery 4 ml methylene was injected into the cervix around the tumor. The blue-dyed lymph nodes were identified as sentinel lymph nodes (SLN) during operation. An immediate topographic section on uterine specimen was performed to separate the PLN from parametria for pathologic examination. RESULTS: Ninety five PLN were presented in 38 (63%) of 60 specimens, with a mean size in diameter of (0.46 +/- 0.24) cm. Among the total PLN, 57 (60%) were located parallel to uterine artery through the entire broad ligament, and the other 38 (40%) were scattered in cardinal ligament, sacral ligament and vesicocervical ligament. After lymphatic mapping, 69 (73%) of PLN were dyed and identified as SLN. Parametrial metastasis was found in 12 (20%) patients, and parametrium was the only site containing positive nodes in 2 patients with parametrial metastasis. On routine pathologic evaluation, 17 PLN were found to be positive. Among the remaining 78 PLN, multilevel sectioning in conjunction with immunohistochemical analysis was carried out and 3 PLN containing micrometastases were identified. CONCLUSIONS: The study shows that PLN are usually found in the parametria, and these nodes often contain metastatic diseases which are easily overlooked. Lymphatic mapping followed by meticulous topographic section is feasible in PLN identification in patients with cervical cancer.

Adult↗

PubMed2006

[Effects of cropping system and cultivation pattern on bacterial populations and anti-fusarium wilt bacteria in melon soils].

A total of 132 soil samples were collected from Xinjiang, Fujian and Zhejiang provinces to study the effects of different cropping system and cultivation pattern on the amount of bacterial populations and the distribution of anti-fusarium wilt bacteria in melon soils. The results of plate counting showed that the amount of culturable bacteria was 15.2 times higher in melon soils than in uncultivated soil, 1.0 times higher in rhizosphere than in non-rhizosphere, 2.5 times higher in the soil with rotation than in that with monoculture, and 0.5 times higher in the soil with non-graft than in that with graft. The Biolog determination of anti-fusarium wilt bacteria in melon soils showed that the soil with water-drought rotation or graft had more antagonistic bacteria, and more than 80% of them were classified as fluorescent Pseudomonas spp.

Antifungal Agents↗

PubMed2005

Chronic aspiration of gastric fluid accelerates pulmonary allograft dysfunction in a rat model of lung transplantation.

OBJECTIVE: Emerging clinical evidence suggests that gastroesophageal reflux disease is associated with pulmonary allograft dysfunction. In this study, we used a model of rat lung transplantation to test the hypothesis that chronic aspiration of gastric contents accelerates pulmonary allograft dysfunction. METHODS: We evaluated the effects of chronic aspiration on pulmonary isografts (strain F344) and pulmonary allografts (strain WKY to strain F344). Chronic aspiration consisted of 0.5 mL/kg of filtered gastric contents injected weekly into the left lung for 4 to 8 weeks beginning 1 week after transplantation. Seven days after the last aspiration, animals were killed, and grafts were evaluated grossly and by histologic and immunochemical analyses, including Masson trichrome staining for collagen and immunostaining for CD68+ and CD8+ cells. Serum cytokine concentrations were determined by bead-based immunoassays or enzyme-linked immunosorbent assay. RESULTS: Allografts without aspiration (n = 12) demonstrated a relatively normal architecture with diffuse International Society for Heart and Lung Transplantation grade 3 acute rejection; occasional grade 4 rejection was noted. In contrast, allografts with chronic aspiration (n = 7) demonstrated severe grade 4 acute rejection with significant monocyte infiltration, fibrosis, and loss of normal alveolar anatomy. Grossly, 8 (67%) of 12 allografts without aspiration seemed to inflate and perfuse normally, whereas all allografts exposed to chronic aspiration were firm and shrunken, without the ability to ventilate (P = .013; Fisher exact test). Aspiration was associated with increases in graft-infiltrating macrophages and CD8+ T cells and higher levels of serum transforming growth factor beta. CONCLUSIONS: Chronic aspiration of gastric contents promotes accelerated allograft failure and may promote a profibrotic environment.

Animals↗

PubMed2005

Effects of carvedilol on cardiac cytokines expression and remodeling in rat with acute myocardial infarction.

OBJECTIVE: A number of observations suggest that cytokines may be important modulators in the ventricular remodeling process. It is unclear whether carvedilol modulates myocardial pro-inflammatory and anti-inflammatory cytokines expression. We hypothesized that carvedilol could improve ventricular remodeling partly through the modulation of cytokines. The goal of this study was to evaluate the effects of carvedilol on cardiac cytokines expression as well as on myocardial and extracellular matrix remodeling in rats with acute myocardial infarction. METHODS: Rats with AMI induced by left anterior descending branch ligation were randomized to carvedilol and control group which were further compared to sham-operated group. We studied the effects of 4-weeks therapy with carvedilol starting 24 h after infarction on 1) hemodynamics, 2) tissue weights, 3) myocardial cytokines (TNF-alpha, IL-1beta, IL-6, IL-10 and TGF-beta1) expression by semi-quantitative RT-PCR and immunoblotting, 4) matrix metalloproteinases activity by gelatin zymography, 5) collagen expression by immunohistochemistry, 6) myocardium fetal gene (alpha and beta myosin heavy chain) expression. RESULTS: Treatment with carvedilol 1) reduced the pro-inflammatory cytokines and fibrogenic cytokine TGF-beta1 levels in myocardium and was associated with the amelioration of the elevated left ventricular diastolic pressure. 2) increased anti-inflammatory cytokine, IL-10 protein expression. 3) reduced matrix metalloproteinases-2 and matrix metalloproteinases-9 activity 4) reduced myocardial collagens 5) did not modify fetal gene re-expression. CONCLUSION: Pro-inflammatory, anti-inflammatory and fibrogenic cytokines are all involved in the process of post-infarction myocardial remodeling. One mechanism underlying the beneficial effects of carvedilol on post-infarction myocardial remodeling may be modulation of the balance between pro- and anti-inflammatory cytokines as well as fibrogenic cytokines and extracellular matrix (ECM) remodeling.

Animals↗

PubMed2005

Sialylation regulates peripheral tolerance in CD4+ T cells.

Decreased binding by the 6C10 auto-antibody serves as a unique marker for CD4+ T cell unresponsiveness after the induction of T cell tolerance in Vbeta8.1 TCR transgenic mice. We further define the nature of the epitope recognized by the 6C10 antibody to be a subset of Thy-1 bearing incompletely sialylated N-linked glycans, and furthermore, we demonstrate that tolerant CD4+ T cells have an increased degree of cell-surface sialylation. To test the significance of the altered glycosylation state identified by the 6C10 auto-antibody in the tolerant CD4+ T cell population, surface sialic acid was cleaved enzymatically. Treatment of purified peripheral CD4+ T cells with Vibrio cholerae sialidase (VCS) leads to increased 6C10 binding, significantly enhances proliferation in the tolerant CD4+ population and corrects defects in phosphotyrosine signaling observed in the tolerant CD4+ T cell. Furthermore, in vivo administration of VCS enhances proliferation in both tolerant and naive CD4+ T cell subsets. These studies suggest that sialylation of glycoproteins on the surface of the CD4+ T cell contributes to the regulation of T cell responsiveness in the tolerant state.

Animals↗

PubMed2005

A key role for the microglial NADPH oxidase in APP-dependent killing of neurons.

Reactive oxygen species (ROS) and deposition of cleaved products of amyloid precursor protein (APP) are thought to contribute to neuronal loss observed in Alzheimer's disease (AD). The relationship between these factors was studied in a neuroblastoma and microglia co-culture system. Overexpression of wild-type APP (APP-wt) or APP with three mutations typical of familial AD (APP-3m) in SH-SY5Y neuroblastoma cells did not directly alter their morphology, growth rate, cell cycle or H(2)O(2) sensitivity. In a co-culture of APP-wt neuroblastoma cells with microglia, microglial cells generated ROS and neuronal cells died. The cell death was more pronounced in APP-3m-expressing neurons. Neuroblastoma cell death was attenuated by ROS-scavengers and was dose-dependently inhibited by the NADPH oxidase inhibitor diphenyleneiodonium chloride (DPI). Macrophage cell lines behaved similarly to microglia in the co-culture model. However, a macrophage cell line deficient in the NADPH oxidase subunit, gp91phox, failed to kill neurons. These results suggest that APP-dependent microglia activation and subsequent ROS generation by the phagocyte NADPH oxidase play a crucial role in neuronal killing in a cellular model of AD.

Alzheimer Disease↗

PubMed2005

Rapid structural characterization of triterpenoid saponins in crude extract from Symplocos chinensis using liquid chromatography combined with electrospray ionization tandem mass spectrometry.

Triterpenoid saponins in bioactive crude extract from Symplocos chinensis were rapidly identified using electrospray ionization multi-stage tandem mass spectrometry (ESI-MSn) and liquid chromatography coupled with sequential mass spectrometry (LC-MSn). According to the characteristic fragmentation behavior of known glucuronide-type triterpenoid saponins isolated from this plant, a total of fourteen constituents in the crude extract were structurally characterized on the basis of their retention time and tandem mass spectrometric analysis, including five pairs of naturally occurring isomers. Except one known saponin formerly obtained, the other constituents were new compounds. The analytical method of LC-MSn combined with ESI-MSn in positive and negative ion modes has been developed for the direct structural elucidation of triterpenoid saponins of this kind in plant extracts.

Chromatography, Liquid↗

PubMed2005

Butyrylcholinesterase, paraoxonase, and albumin esterase, but not carboxylesterase, are present in human plasma.

The goal of this work was to identify the esterases in human plasma and to clarify common misconceptions. The method for identifying esterases was nondenaturing gradient gel electrophoresis stained for esterase activity. We report that human plasma contains four esterases: butyrylcholinesterase (EC 3.1.1.8), paraoxonase (EC 3.1.8.1), acetylcholinesterase (EC 3.1.1.7), and albumin. Butyrylcholinesterase (BChE), paraoxonase (PON1), and albumin are in high enough concentrations to contribute significantly to ester hydrolysis. However, only trace amounts of acetylcholinesterase (AChE) are present. Monomeric AChE is seen in wild-type as well as in silent BChE plasma. Albumin has esterase activity with alpha- and beta-naphthylacetate as well as with p-nitrophenyl acetate. Misconception #1 is that human plasma contains carboxylesterase. We demonstrate that human plasma contains no carboxylesterase (EC 3.1.1.1), in contrast to mouse, rat, rabbit, horse, cat, and tiger that have high amounts of plasma carboxylesterase. Misconception #2 is that lab animals have BChE but no AChE in their plasma. We demonstrate that mice, unlike humans, have substantial amounts of soluble AChE as well as BChE in their plasma. Plasma from AChE and BChE knockout mice allowed identification of AChE and BChE bands without the use of inhibitors. Human BChE is irreversibly inhibited by diisopropylfluorophosphate, echothiophate, and paraoxon, but mouse BChE spontaneously reactivates. Since human plasma contains no carboxylesterase, only BChE, PON1, and albumin esterases need to be considered when evaluating hydrolysis of an ester drug in human plasma.

Acetylcholinesterase↗

PubMed2005

MRS algorithm: a new method for searching myocardial region in SPECT myocardial perfusion images.

First, the necessity of automatically segmenting myocardium from myocardial SPECT image is discussed in Section 1. To eliminate the influence of the background, the optimal threshold segmentation method modified for the MRS algorithm is explained in Section 2. Then, the image erosion structure is applied to identify the myocardium region and the liver region. The contour tracing method is introduced to extract the myocardial contour. To locate the centriod of the myocardium, the myocardial centriod searching method is developed. The protocol of the MRS algorithm is summarized in Section 6. The performance of the MRS algorithm is investigated and the conclusion is drawn in Section 7. Finally, the importance of the MRS algorithm and the improvement of the MRS algorithm are discussed.

Algorithms↗

PubMed2005

Grain-size effect on the structure and antiobesity activity of konjac flour.

The effect of high-frequency oscillatory type ball-mill treatment on the structure and antiobesity activity of konjac flour was investigated. The grain size of konjac flour changed from 657.3 microm (d(50)) to 23.7 microm (d(50)) after 4 h of treatment. The structural change of the konjac flour with different grain size was characterized by using X-ray diffraction (XRD) differential scanning calorimetry (DSC). The results indicated that the crystallinity decreased and the diffraction peak drifted not only by when the crystallization region was reduced but also when the crystalline structure was changed. With the decrease of the grain size and crystallinity, the konjac flour grain, especially the 4 h milled konjac flour, swelled more rapidly and led to the improvement of the antiobesity effect. Compared with the native konjac flour, the 4 h milled konjac flour could significantly decrease the body weight and total wet weight of fat of nutritional obese rats (P < 0.05) and also decreased the contents of triglyceride, glucose, and high-density lipoprotein in blood of nutritional obese rat significantly (P < 0.05), which meant the grain-size effect of konjac flour improved its antiobesity activity notably.

Amorphophallus↗

PubMed2005

Participation of sodium in the bonding of anionic networks: synthesis, structure, and bonding of Na3MIn2 (M = Au, Ag).

Two isostructural compounds Na(3)MIn(2) (M = Au, Ag) with a NiTi(2)-type structure (Fd-3m) were synthesized via typical high-temperature reactions. The anionic M-In structure consists of tetrahedral star building units [In(4)M(4/2)] (TS) that are connected into a three-dimensional framework via shared TS vertexes, with the Na atoms filling the cages. On the basis of TB-LMTO-ASA calculations, the electronic structures of both compounds show substantial participation of sodium in the overall bonding of the structure. Compared with the Ag compound, relativistic effects in the Au phase appear to be significant, as shown in the M-M and M-Na bond length decreases of 0.03-0.04 A.

Journal Article↗

PubMed2005

Comparative immunogenicity in rhesus monkeys of multi-protein HIV-1 (CRF02_AG) DNA/MVA vaccines expressing mature and immature VLPs.

We developed an AIDS vaccine for Western and West-Central Africa founded on HIV-1 subtype CRF02_AG. Rhesus macaques were primed with Gag-Pol-Env-expressing plasmid DNA and boosted with a recombinant modified vaccinia virus Ankara (rMVA), expressing matched proteins. Two DNA vaccine constructs (IC1-90 and IC48) that differed by point mutations in gag and pol were compared. IC1-90 produces primarily immature (core comprises unprocessed Pr55Gag) HIV-like particles (VLPs) and IC48 produces mature VLP with processed Pr55Gag, immature VLP, and intracellular protein aggregates. Both vaccines raised significant cellular responses for Gag, Pol, and Env. Approximate twofold higher ELISPOT responses to Gag and Env epitopes were observed for IC48 animals than for IC1-90 animals at the peak post-MVA effector (P = 0.028) and late memory (P = 0.051) phases, respectively. Greater breadth for IC48-primed animals was observed than for IC1-90-primed animals at peak response (P = 0.03). Our results indicated that the vaccines elicited high frequency T cell responses and primed anti-Env antibody. They also suggest that expression of different forms of VLP has a significant effect on elicited cellular and humoral immunity.

AIDS Vaccines↗

PubMed2005

Limitations and potentials of current motif discovery algorithms.

Computational methods for de novo identification of gene regulation elements, such as transcription factor binding sites, have proved to be useful for deciphering genetic regulatory networks. However, despite the availability of a large number of algorithms, their strengths and weaknesses are not sufficiently understood. Here, we designed a comprehensive set of performance measures and benchmarked five modern sequence-based motif discovery algorithms using large datasets generated from Escherichia coli RegulonDB. Factors that affect the prediction accuracy, scalability and reliability are characterized. It is revealed that the nucleotide and the binding site level accuracy are very low, while the motif level accuracy is relatively high, which indicates that the algorithms can usually capture at least one correct motif in an input sequence. To exploit diverse predictions from multiple runs of one or more algorithms, a consensus ensemble algorithm has been developed, which achieved 6-45% improvement over the base algorithms by increasing both the sensitivity and specificity. Our study illustrates limitations and potentials of existing sequence-based motif discovery algorithms. Taking advantage of the revealed potentials, several promising directions for further improvements are discussed. Since the sequence-based algorithms are the baseline of most of the modern motif discovery algorithms, this paper suggests substantial improvements would be possible for them.

Algorithms↗

PubMed2005

Characterization of the c-type lysozyme gene family in Anopheles gambiae.

Seven new c-type lysozyme genes were found using the Anopheles gambiae genome sequence, increasing to eight the total number of genes in this family identified in this species. The eight lysozymes in An. gambiae have considerable variation in gene structure and expression patterns. Lys c-6 has the most unusual primary amino acid structure as the predicted protein consists of five lysozyme-like domains. Transcript abundance of each c-type lysozyme was determined by semiquantitative RT-PCR. Lys c-1, c-6 and c-7 are expressed constitutively in all developmental stages from egg to adult. Lys c-2 and c-4 also are found in all stages, but with relatively much higher levels in adults. Conversely, Lys c-3 and c-8 transcripts are highest in larvae. Lys c-1, c-6 and c-7 transcripts are found in nearly all the adult tissue samples examined while Lys c-2 and Lys c-4 are more restricted in their expression. Lys c-1 and c-2 transcripts are clearly immune responsive and are increased significantly 6-12 h post challenge with bacteria. The functional adaptive changes that may have evolved during the expansion of this gene family are briefly discussed in terms of the expression patterns, gene and protein structures.

Amino Acid Sequence↗

PubMed2005

Correlation of the expression of telomerase RNA with risk factors for recurrence of sebaceous gland carcinoma.

AIMS: To investigate the expression of human telomerase gene RNA (hTR) and human telomerase reverse transcriptase (hTRT) in eyelid sebaceous gland carcinoma and to evaluate risk factors for sebaceous carcinoma recurrence. METHODS: The expression patterns of hTR and hTRT were detected by in situ hybridization (ISH) in paraffin-embedded samples of 55 eyelid sebaceous gland carcinoma, 12 chalazia, and four sebaceous adenoma. The proliferation index (PI) of sebaceous gland carcinoma was determined by Ki-67 immunolabeling and the results were compared with the expression of hTR and hTRT. Several factors for recurrence of sebaceous gland carcinoma were evaluated by statistical analysis. RESULTS: Expression of hTR and hTRT was present mainly in the sebaceous gland carcinoma tissues and not in adjacent tissues of carcinoma, chalazia, and sebaceous adenoma. The prevalence of hTR, hTRT, and Ki-67 expression in 55 sebaceous carcinoma samples were 84.45%, 58.1%, and 78.18%, respectively. hTR expression was highly associated with the degree of carcinoma differentiation (P<0.001) and hTRT expression was correlated with the proliferation index as determined by Ki-67 staining (P<0.005). There was a correlation between the recurrence of sebaceous gland carcinoma and the patient's onset age (OR=0.914, P<0.05), as well as the time to first treatment (OR=1.163, P<0.01). CONCLUSIONS: Telomerase may play an important role in the carcinogenesis of sebaceous gland carcinoma, and expression of hTR and hTRT combined with other features of sebaceous gland carcinoma may be helpful for the diagnosis and evaluation of clinical prognosis. Risk factors for recurrence of sebaceous gland carcinoma are patients' onset age and the time to first treatment.

Adenocarcinoma, Sebaceous↗