Biomedical subjects

Fei Wang

Publications and source records attributed to Fei Wang.

At least 55 records · Page 3Linked to original sources

PubMed2006

[Treatment of dural arteriovenous fistula by transarterial embolization with low dose of N-butyl-2-cyanoacrylate].

OBJECTIVE: To evaluate the efficacy of treatment of dural arteriovenous fistula (DAVF) by transarterial embolization with low dose of N-butyl-2-cyanoacrylate (NBCA). METHODS: Eighteen patients, 6 males and 12 females, aged 47.5 (23-72), with DAVF, 12 with carotid cavernous fistula and 6 with fistula in parietal lobe, underwent transarterial embolization with low dose of NBCA (10%-20%). The key point of transarterial embolization with low dose of NBCA was that low dose NBCA was injected and embolized the veins and then was reversed into the other supplying arteries. RESULTS: Seventeen patients with DAVF in cavernous region and 6 patients with DAVF in parietal lobe were cured anatomically, with the clinical syndromes disappearing. In 1 patient with DAVF in cavernous region the clinical syndrome were moderately improved after transarterial embolization, however, worsened 2 days later. Cerebrovascular angiography demonstrated that the vein was not completely embolized and the draining vein was broadened, and the clinical syndromes were moderately improved again after carotid artery compression therapy for 10 days. CONCLUSION: Convenient and fast, and with low cost and satisfying efficacy, transarterial embolization with low dose of NBCA is a better choice for treatment of DAVF in some cases. The key point of this approach is that the tip of microcatheter is close as much as possible to the fistulae, and NBCA is injected into the fistulae and make the vein diffused well. Attention should be paid to avoid dangerous anastomosis.

Adult↗

PubMed2006

Joint registration and segmentation of neuroanatomic structures from brain MRI.

RATIONALE AND OBJECTIVES: Segmentation of anatomic structures from magnetic resonance brain scans can be a daunting task because of large inhomogeneities in image intensities across an image and possible lack of precisely defined shape boundaries for certain anatomical structures. One approach that has been quite popular in the recent past for these situations is the atlas-based segmentation. The atlas, once constructed, can be used as a template and can be registered nonrigidly to the image being segmented thereby achieving the desired segmentation. The goal of our study is to segment these structures with a registration assisted image segmentation technique. MATERIALS AND METHODS: We present a novel variational formulation of the registration assisted image segmentation problem which leads to solving a coupled set of nonlinear Partial Differential Equations (PDEs) that are solved using efficient numeric schemes. Our work is a departure from earlier methods in that we can simultaneously register and segment in three dimensions and easily cope with situations where the source (atlas) and target images have very distinct intensity distributions. RESULTS: We present several examples (20) on synthetic and (3) real data sets along with quantitative accuracy estimates of the registration in the synthetic data case. CONCLUSION: The proposed atlas-based segmentation technique is capable of simultaneously achieve the nonrigid registration and the segmentation; unlike previous methods of solution for this problem, our algorithm can accommodate for image pairs having very distinct intensity distributions.

Algorithms↗

PubMed2006

Humulane-type sesquiterpenoids from the mushroom Lactarius mitissimus.

Five new humulane-type sesquiterpenes, mitissimols A (1), B (2), and C (3), and a mixture of mitissimol A oleate (4) and mitissimol A linoleate (5), were isolated from the fruiting bodies of Lactarius mitissimus. Their structures were elucidated on the basis of comprehensive spectroscopic techniques and necessary chemical methods. The relative stereochemistry of 1 was determined by single-crystal X-ray diffraction analysis.

Agaricales↗

PubMed2006

Hypocrellin D, a cytotoxic fungal pigment from fruiting bodies of the ascomycete Shiraia bambusicola.

A fungal pigment, hypocrellin D (1), together with three known perylenequinone derivatives hypocrellin A (2), B (3) and C (4), was isolated from the fruiting bodies of Shiraia bambusicola. Its structure was elucidated on the basis of spectral data including 2D NMR experiments. Hypocrellin D (1) significantly inhibited the growth of tumor cell lines Bel-7721, A-549 and Anip-973 with IC50 values of 1.8, 8.8, 38.4 microg/ml, respectively.

Antibiotics, Antineoplastic↗

PubMed2006

Racial/ethnic differences in diabetes care for older veterans: accounting for dual health system use changes conclusions.

BACKGROUND: Veterans Health Administration (VHA) databases are used extensively to study racial/ethnic disparities; however, these databases may not capture all care received by VHA patients. OBJECTIVES: We examined the extent to which accounting for non-VHA care changed conclusions about racial/ethnic disparities for VHA patients with diabetes. METHODS: Using a cross-sectional observational study, we analyzed a national sample of noninstitutionalized Hispanic (n = 5931), black (n = 24,670), and white (n = 149,222) VHA patients with diabetes who were at least 65 years of age for receipt of annual HbA1c testing, low-density lipoprotein (LDL) cholesterol testing, or eye examination from VHA and Medicare administrative files. RESULTS: In VHA alone data, adjusting for patient characteristics, Hispanic and black patients were as likely as white patients to receive HbA1c testing (odds ratio 1.06 [95% confidence interval 0.99-1.13] and 1.04 [1.00-1.07], respectively), and more likely to receive eye examinations (1.31 [1.24-1.38] and 1.33 [1.29-1.37], respectively). Hispanic patients were equally likely (1.01 [0.95-1.07]) and black patients were less likely (0.81 [0.79-0.84]) to receive LDL testing versus white patients. In VHA plus Medicare data, Hispanic and black patients were less likely than white patients to receive HbA1c (0.76 [0.71-0.82] and 0.83 [0.80-0.87], respectively) and LDL testing (0.84 [0.79-0.90] and 0.70 [0.68-0.72], respectively), and equally likely to receive eye examinations (0.91 [0.86-0.96]) and 0.98 [0.95-1.01]), respectively). Accounting for VHA facility had little effect on results. CONCLUSIONS: Restricting to VHA data masks racial/ethnic disparities in care of VHA patients. VHA researchers must be aware and supplement VHA data with other sources whenever possible.

Black or African American↗

PubMed2006

[Effect of the ethyl acetate extract of zhi ju zi on serum makers and the expression of TGF-beta1 in rats with hepatic fibrosis].

OBJECTIVE: To study the effect of the Ethyl Acetate Extract of Zhi Ju Zi on hepatic fibrosis. METHODS: Model of liver fibrosis in rats was induced by CCl4. The level of hyaluronic acid (HA) and laminin (LN) was detected by RIN. The expression of TGF-beta1 of the rat liver was detected by RT-PCR. RESULTS: After treatment, the level of HA was apparently decreased (P < 0.05); the level of LN wsn't apparently different with the Colchicin group (P > 0.05); The expression of TGF-beta1, was apparently decreased (P < 0.05) CONCLUSION: The Ethyl Acetate Extract of Zhi Ju Zi can effectviely decrease the level of serum markers of hepatic fibrosis and the expression of TGF-beta1.

Acetates↗

PubMed2006

[Effect of Hovenia dulcis extract on expression of MMP-13 and TIMP-1 in hepatic tissue].

OBJECTIVE: To investigate the effects of Hovenia dulcis extract on mRNA expression of MMP-13 and TIMP-1 mRNA in hepatic tissue in experimental rats. METHOD: 48 male Sprague-Dawley rats were randomly divided into 2 groups: normal group (16) and model group (32), hepatic fibrosis was induced by CCl4 for 6 weeks in rats, 8 rats were sacrificed at the end of the 6th week from every group respectively, HE staining of hepatic tissue was performed; In the model group, rats randomly subdivided into 3 groups: spontaneous recovery group, control group and medication administration group, 8 rats were sacrificed at the end of the 12th week from every group respectively, the mRNA levels of MMP-13 and TIMP-1 in hepatic tissue were assayed by semi-quantitative RT-PCR. RESULT: The mRNA expression of MMP-13 among the 4 groups were not statistically significant, but the mRNA expression of TIMP-1 among the 4 groups were statiscally significant. The levels of TIMP-1 mRNA were significantly increased in control group and medication administration group compared, with those in the model group (P < 0.05), and reverse effects of medication administration groups were significantly high than those of control group (P < 0.05). CONCLUSION: Inhibition of the mRNA expression of TIMP-1 may be the mechanism of reversing hepatic fibrosis H. dulcis, for thus collogen degradation system was recoveried gradually.

Animals↗

PubMed2006

[The role of serine endopeptidase in cucumber leaf senescence].

The role of serine endopeptidase in cucumber leaf senescence was studied by using the inhibitor of serine endopeptidase and plant growth regulators (6-BA and ABA) on darkness-induced cucumber leaves. The results showed that the senescence of cucumber leaves were delayed by AEBSF [4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride], an inhibitor of serine-type endopeptidase, or 6-BA treatment. The chlorophyll contents increased by AEBSF (Fig.3) and the protein degradation of leaves under AEBSF treatment declined more slowly than in the control or under ABA 50 micromol/L treatment (Fig.4), partly because the activities of serine endopeptidases became lower during senescence. However, the activities of endopeptidase in cucumber leaf were increased by ABA 50 micromol/L (Fig.2A), furthermore, the MDA content were also influenced by AEBSF and plant growth regulators (Fig.5). Native gradient PAGE showed that six bands of isoenzymes were detected in cucumber leaves and four bands of which were the type of serine-endopeptidase (Fig.1), and proved that the activities of serine-endopeptidase were inhibited by AEBSF, but enhanced by ABA (Fig.2B) in the leaves. It implies that serine endopeptidases might play an important role in cucumber leaf senescence.

Abscisic Acid↗

PubMed2006

[Efficacy of DICE (dexamethasone, etoposide, ifosfamide, and cisplatin) regimen on recurrent and refractory non-Hodgkin's lymphoma].

BACKGROUND & OBJECTIVE: There is no standard salvage regimen for patients with recurrent and refractory non-Hodgkin's lymphoma (NHL) so far. This study was to investigate the efficacy of DICE (dexamethasone, isofosfamide, cisplatin, and etoposide) regimen on recurrent and refractory NHL, and observe the adverse events. METHODS: Clinical records of 80 patients with recurrent and refractory NHL, who failed to get remission from CHOP regimen (cyclophosfamide, vincristine, and donaurubicin) and accepted DICE as a salvage regimen for 6 cycles, were reviewed. Of the 80 patients, 25 were T-cell original, and the other 55 were B-cell original. The efficacy of DICE regimen and adverse events were evaluated. RESULTS: The total response rate (RR) of these 80 patients was 56.3%. The complete remission (CR) rate was 27.5%.The total response rate was 48.0% for T-cell NHL and 60.0% for B-cell NHL. The CR rate was 16.0% for T-cell NHL and 32.7% for B-cell NHL. Myelosuppression, nausea, vomit, alopecia, and electrolytes disorder were major adverse events, and could be cured after treatment. No chemotherapy-related death occurred. CONCLUSION: DICE regimen is effective in treating recurrent and refractory NHL.

Adult↗

PubMed2005

Hyperglycemia increased brain ischemia injury through extracellular signal-regulated protein Kinase.

This study was to examine the alterations in the phosphorylation of mitogen-activated protein kinase (MAPK) family in transient brain ischemia under a hyperglycemia and to highlight the molecular mechanisms by which hyperglycemia exacerbates brain damage resulting from stroke. Extracellular signal-regulated protein kinase (ERK) expression was studied in rats subjected to global brain ischemia with pre-ischemic normoglycemic (CIN) and hyperglycemic (CIH) conditions. In another group, the hyperglycemic ischemic rats were pretreated with ERK inhibitor U0126 (U0126). Increased phospho-ERK1/2 immunoreactive neurons in the cingulate cortex and hippocampal CA3 were detected in CIN after ischemia and reperfusion. The numbers of phospho-ERK1/2-positive neurons were further increased significantly in CIH compared to the CIN. Pretreatment with U0126 in CIH rats significantly decreased ERK1/2 immunoreactive cells. Western blot analyses confirmed that phospho-ERK1/2 increased significantly after 30 min ischemia and reperfusion compared to non-ischemic controls in both the CIN and CIH groups. The increase of phospho-ERK1/2 was more prominent in the CIH than in the CIN group after 3 and 6h of reperfusion. Treatment with U0126 significantly reduced phospho-ERK1/2 in the CIH group. The findings presented here suggest that ERK1/2 may play a role in mediating neuronal cells death under hyperglycemic condition.

Animals↗

PubMed2005

Comparison of chlordecone effects on autoimmunity in (NZBxNZW) F(1) and BALB/c mice.

It has been shown previously that chronic treatment with relatively low doses of chlordecone accelerates the development of systemic lupus erythematosus (SLE) in ovariectomized female (NZBxNZW) F(1) mice. In this study, the effect of chronic chlordecone treatment on SLE was evaluated in ovary-intact female (NZBxNZW) F(1) mice, as well as in female mice from a strain that is not lupus-prone, BALB/c. Chlordecone was administered chronically via implanted sustained-release pellets, and mice were monitored over time for the appearance of elevated autoantibodies (anti-dsDNA and anti-chromatin) and for the development of renal impairment, both indicators of SLE. Chlordecone treatment in (NZBxNZW) F(1) mice shortened significantly the time to onset of elevated autoantibody titers and renal disease in a dose-related manner. The doses required to produce this effect were similar to those observed previously to accelerate SLE development in ovariectomized females. Treatment of female BALB/c mice with chlordecone for up to one year did not produce elevated autoantibody titers or renal disease, suggesting an inability of chlordecone to cause a break in tolerance in this strain. These observations confirm the ability of chronic chlordecone to influence SLE, but demonstrate the importance of genetic background for this effect.

Animals↗

PubMed2005

Asymmetric transfer hydrogenation of ketones catalyzed by hydrophobic metal-amido complexes in aqueous micelles and vesicles.

[Reaction: see text]. Asymmetric transfer hydrogenation of ketones, especially alpha-bromomethyl aromatic ketones, catalyzed by unmodified, hydrophobic transition metal-amido complexes (TsDPEN-M), was performed successfully with significant enhancement of activity, chemoselectivity, and enantioselectivity (up to 99% ee) in aqueous media containing micelles and vesicles. The hydrophobic catalyst, embedded in micelles constructed from the surfactant cetyltrimethylammonium bromide (CTAB), could be separated from the organic phase along with the products and was recycled for at least six times.

Journal Article↗

PubMed2005

Rho1 regulates Drosophila adherens junctions independently of p120ctn.

During animal development, adherens junctions (AJs) maintain epithelial cell adhesion and coordinate changes in cell shape by linking the actin cytoskeletons of adjacent cells. Identifying AJ regulators and their mechanisms of action are key to understanding the cellular basis of morphogenesis. Previous studies linked both p120catenin and the small GTPase Rho to AJ regulation and revealed that p120 may negatively regulate Rho. Here we examine the roles of these candidate AJ regulators during Drosophila development. We found that although p120 is not essential for development, it contributes to morphogenesis efficiency, clarifying its role as a redundant AJ regulator. Rho has a dynamic localization pattern throughout ovarian and embryonic development. It preferentially accumulates basally or basolaterally in several tissues, but does not preferentially accumulate in AJs. Further, Rho1 localization is not obviously altered by loss of p120 or by reduction of core AJ proteins. Genetic and cell biological tests suggest that p120 is not a major dose-sensitive regulator of Rho1. However, Rho1 itself appears to be a regulator of AJs. Loss of Rho1 results in ectopic accumulation of cytoplasmic DE-cadherin, but ectopic cadherin does not accumulate with its partner Armadillo. These data suggest Rho1 regulates AJs during morphogenesis, but this regulation is p120 independent.

Adherens Junctions↗

PubMed2005

Regulation of cardiac sarcoplasmic reticulum Ca release by luminal [Ca] and altered gating assessed with a mathematical model.

Cardiac excitation-contraction coupling is initialized by the release of Ca from the sarcoplasmic reticulum (SR) in response to a sudden increase in local cytosolic [Ca] ([Ca]i) within the junctional cleft. We have tested the hypothesis that functional ryanodine receptor (RyR) regulation plays a major role in the regulation of myocyte Ca. A mathematical model with unique characteristics was used to simulate Ca homeostasis. Specifically, the model was designed to accurately represent the SR [Ca]-dependence of release from a variety of experimentally produced data sets. The simulated data for altered RyR Ca sensitivity demonstrated a regulatory feedback loop that resulted in the same release at lower [Ca]SR. This suggests that the primary role of myocyte RyR regulation may be to decrease SR [Ca] without decreasing the size of the [Ca]i transient. The model results suggest that this action moderates the increased SR [Ca] observed with adrenergic stimulation and may keep the [Ca]SR below the threshold for delayed afterdepolarizations and arrhythmia. However, increased Ca affinity of the RyR increased the probability of delayed afterdepolarizations when heart failure was simulated. We conclude that RyR regulation may play a role in preventing arrhythmias in healthy myocytes but that the same regulation may have the opposite effect in chronic heart failure.

Animals↗

PubMed2005

Distribution of beacon immunoreactivity in the rat brain.

Beacon is a novel peptide isolated from the hypothalamus of Israeli sand rat. In the present study, we determined the distribution of beacon in the rat brain using immunohistochemical approach with a polyclonal antiserum directed against the synthetic C-terminal peptide fragment (47-73). The hypothalamus represented the major site of beacon-immunoreactive (IR) cell bodies that were concentrated in the paraventricular nucleus (PVN) and the supraoptic nucleus (SON). Additional immunostained cells were found in the septum, bed nucleus of the stria terminalis, subfornical organ and subcommissural organ. Beacon-IR fibers were seen with high density in the internal layer of the median eminence and low to moderate density in the external layer. Significant beacon-IR fibers were also seen in the nucleus of the solitary tract and lateral reticular formation. The beacon neurons found in the PVN were further characterized by double label immunohistochemistry. Several beacon-IR neurons that resided in the medial PVN were shown to coexpress corticotrophin-releasing hormone (CRH) and most labeled beacon fibers in the external layer of median eminence coexist with CRH. The topographical distribution of beacon-IR in the brain suggests multiple biological activities for beacon in addition to its proposed roles in modulating feeding behaviors and pituitary hormone release.

Animals↗

PubMed2005

Molecular self-assembling and the fluorescence enhancement in morin-Al3+-cetyltrimethylammonium bromide-protein system.

Fluorescence enhancement effect of the morin-Al3+-cetyltrimethylammonium bromide (CTAB)-bovine serum albumin (BSA) system is reported here and the interaction mechanism is studied using fluorescence, resonance light scattering (RLS), absorption spectroscopy, Far-UV circular dichroism (CD) spectrum and small angle X-ray scattering (SAXS) measurement. It is considered that protein can bind with Al3+, morin and CTAB through self-assembling function with electrostatic attraction, hydrogen bond, hydrophobic interaction and Vander Waal force etc, and forms a supermolecular association with multilayer structure, in which morin-Al3+ is clamped between BSA and CTAB. In this system, the fluorescence enhancement of morin originates from both intermolecular energy transfer between BSA and morin, and the hydrophobic microenvironment provided by BSA and CTAB. Whereas Al3+ plays a key role for the enhancement of energy transfer efficiency because it provides an efficient channel for the energy transfer between BSA and morin.

Aluminum Compounds↗

PubMed2005

Local delivery of a viral vector mitigates neutralization by antiviral antibodies and results in efficient transduction of rabbit liver.

Antiviral antibodies within the human population remain a barrier to the effective clinical use of viral gene transfer vectors. We have asked whether local, balloon catheter-mediated delivery of a viral vector to the rabbit liver using a hepatic vein might mitigate the neutralizing effects of antiviral antibodies. We have compared directly the ability of adenovirus (Ad2) encoding nuclear-localized beta-galactosidase to infect the rabbit liver after local and systemic delivery in both the presence and the absence of defined anti-Ad2 antibody titers. In naive rabbits, local delivery resulted in higher beta-galactosidase expression compared to systemic delivery. In the presence of passively administered anti-Ad2 antibodies, local delivery resulted in expression levels that were comparable to those obtained in naive rabbits by systemic delivery. Local delivery also resulted in the majority of expression originating from hepatocytes, even in passively immunized animals, a result that could not be duplicated using the systemic approach. Since systemic delivery of adenovirus in naive animal models results in transgene expression levels often regarded as therapeutic, these results predict that local hepatic vein delivery of a viral vector is a clinically practical approach to mitigate neutralizing antiviral antibodies and generate therapeutic levels of transgene expression.

Adenoviridae↗

PubMed2005

Load-dependent kinetics of myosin-V can explain its high processivity.

Recent studies provide strong evidence that single myosin class V molecules transport vesicles and organelles processively along F-actin, taking several 36-nm steps, 'hand over hand', for each diffusional encounter. The mechanisms regulating myosin-V's processivity remain unknown. Here, we have used an optical-tweezers-based transducer to measure the effect of load on the mechanical interactions between rabbit skeletal F-actin and a single head of mouse brain myosin-V, which produces its working stroke in two phases. We found that the lifetimes of the first phase of the working stroke changed exponentially and about 10-fold over a range of pushing and pulling forces of +/- 1.5 pN. Stiffness measurements suggest that intramolecular forces could approach 3.6 pN when both heads are bound to F-actin, in which case extrapolation would predict the detachment kinetics of the front head to slow down 50-fold and the kinetics of the rear head to accelerate respectively. This synchronizing effect on the chemo-mechanical cycles of the heads increases the probability of the trail head detaching first and causes a strong increase in the number of forward steps per diffusional encounter over a system with no strain dependence.

Actins↗