Efficient immobilization of agarase using carboxyl-functionalized magnetic nanoparticles as support

Background: A simple and efficient strategy for agarase immobilization was developed with carboxyl-functionalized magnetic nanoparticles (CMNPs) as support. The CMNPs and immobilized agarase (agarase-CMNPs) were characterized by transmission electron microscopy, dynamic light scattering, vibrating sample magnetometry, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and zeta-potential analysis. The hydrolyzed products were separated and detected by ESI-TOF-MS. Results: The agarase-CMNPs exhibited a regular spherical shape with a mean diameter of 12 nm, whereas their average size in the aqueous solution was 43.7 nm as measured by dynamic light scattering. These results indicated that agarase-CMNPs had water swelling properties. Saturation magnetizations were 44 and 29 emu/g for the carriers and agarase-CMNPs, respectively. Thus, the particles had superparamagnetic characteristics, and agarase was successfully immobilized onto the supports. Agaro-oligosaccharides were prepared with agar as substrate using agarase-CMNPs as biocatalyst. The catalytic activity of agarase-CMNPs was unchanged after six reuses. The ESI-TOF mass spectrogram showed that the major products hydrolyzed by agarase-CMNPs after six recycle uses were neoagarotetraose, neoagarohexaose, and neoagarooctaose. Meanwhile, the end-products after 90 min of enzymatic treatment by agarase-CMNPs were neoagarobiose and neoagarotetraose. Conclusions: The enhanced agarase properties upon immobilization suggested that CMNPs can be effective carriers for agarase immobilization. Agarase-CMNPs can be remarkably used in developing systems for repeated batch production of agar-derived oligosaccharides.

Application of Magnetoencephalography with Synthetic Aperture Magnetometry in Localization of Motor Cortex and Epileptogenic Focus / 中国康复理论与实践

@#Objective To investigate the value of synthetic aperture magnetometry (SAM) in localizing motor cortex and epileptogenic focus for brain lesions near the central sulcus and to clear its advantage in the localization. Methods 12 patients (6 patients with epilepsy) were enrolled in this study. Before the operation, the patients were all taken Karnofsky Performance Status Score (KPS), examined with MEG by SAM technique in the localization of motor cortex and epileptogenic focus to determine their position relationship, and guide the scheme of surgery programme. During the operation, the location of hand-motor functional area were identified with evoked potential monitoring awaking test, and epileptogenic focus with electrocorticogram (ECoG) monitoring. The accuracy of location was assessed with the hand movement and KPS score, and the epileptic attack were evaluated with Engel curative effect grading. They were followed up for 2 years. Results The motor cortex of all the patients were located near the precentral gyrus with SAM and the localization of epileptogenic focus in 6 patients by SAM was consistent with that by ECoG. All the operations were based on and guided by the SAM. After the operations, the motor function and KPS score of 8 patients improved. No extra functional lesions happened in all patients. Epilepsy was well controlled in 5 cases. Conclusion SAM can correctly localize the motor cortex and epileptogenic focus. Meanwhile position relationship between the intracranial lesions and motor functional areas and epileptic focus can be clear. It is a valuable method for surgical planning and epilepsy controlling and will decrease the occurrence of neurological deficits after operation.

The cytotoxicity of microglass fibers on alveolar macrophages of fischer 344 rats evaluated by cell magnetometry, cytochemisry and morphology

<p><b>OBJECTIVES</b>The toxicity of microglass fibers (MG), one of the man-made mineral fibers, has not been sufficiently evaluated. The aim of the current study was to evaluate the cytotoxicity of MGin vitro.</p><p><b>METHODS</b>Alveolar macrophages were obtained from the bronchoalveolar lavage of male F344/N rats. The macrophages were exposed to MG at concentrations of 0, 40, 80, 160 and 320 μg/ml. The effects of MG on the macrophages were examined by cell magnetometry, LDH assay and morphological observation.</p><p><b>RESULTS</b>In the cell magnetometry experiment, a significant delay of relaxation (the reduction of remanent magnetic field strength) was observed in the cells treated with 160 and 320 μg/ml of MG in a dose-dependent manner. A significant increase in LDH release was also observed in the cells with 160 and 320 μg/ml in a dose-dependent manner. Changes in the cytoskeleton were observed after exposure to MG by immunofluorescent microscopy using an α-tubulin antibody.</p><p><b>CONCLUSIONS</b>The cytotoxicity of MG on alveolar macrophages was demonstrated with cell magnetometry. The mechanism of the toxic effects of MG was related to cytoskeleton damage.</p>

The Cytotoxicity of Microglass Fibers on Alveolar Macrophages of Fischer 344 Rats Evaluated by Cell Magnetometry, Cytochemisry and Morphology

Objectives: The toxicity of microglass fibers (MG), one of the man-made mineral fibers, has not been sufficiently evaluated. The aim of the current study was to evaluate the cytotoxicity of MG in vitro. Methods: Alveolar macrophages were obtained from the bronchoalveolar lavage of male F344/N rats. The macrophages were exposed to MG at concentrations of 0, 40, 80, 160 and 320 μg/ml. The effects of MG on the macrophages were examined by cell magnetometry, LDH assay and morphological observation. Results: In the cell magnetometry experiment, a significant delay of relaxation (the reduction of remanent magnetic field strength) was observed in the cells treated with 160 and 320 μg/ml of MG in a dose-dependent manner. A significant increase in LDH release was also observed in the cells with 160 and 320 μg/ml in a dose-dependent manner. Changes in the cytoskeleton were observed after exposure to MG, by immunofluorescent microscopy using an α-tubulin antibody. Conclusions: The cytotoxicity of MG on alveolar macrophages was demonstrated with cell magnetometry. The mechanism of the toxic effects of MG was related to cytoskeleton damage.

In Vitro Magnetometric Evaluation for Toxicity to Alverolar Macrophage of Arsenic Compounds / 예방의학회지

OBJECTIVES: This study was conducted to evaluate the cytotoxicity of gallium arsenide(GaAs), indium phosphide(InP) and indium arsenide(InAs) all of which are used as the semiconductor eletments in semiconductor industry. METHODS: Cytotoxicity in the alveolar macrophage was evaluated by the measurement of in vitro magnetometry, LDH release assay and histological examination. RESULTS: The relaxation curves by the in vitro magnetometry showed that GaAs has the cytotoxicity for the alveolar macrophage which is more significant in the higher dosages, while this cytotoxicity is not appeared in the groups added with InP or InAs or PBS. In the decay constant for two minutes after magnetization, GaAs-added groups showed a significant decrease with increasing doses, but both InP- and InAs-added groups did not show any significance. The LDH release assay showed a dose-dependent increasing tendency in the GaAs-, InP- and InAs-added groups. In terms of cellular morphological changes, GaAs-added groups revealed such severe cellular damages as prominent destructions in cell membranes and their morphological changes of nucleus, while InP- and InAs-added groups remained intact in intracellular structures, except for cytoplasmic degenerations. CONCLUSIONS: It is suggested that GaAs is more influential to cytotoxicity of alveolar macrophages than InP and InAs.