Biomedical subjects
Publications and source records attributed to L Li.
This paper has reported the effect of sunshine to stromata of Cordyceps senensis grown in Kanding, Sichuan and Naqu, Tibet. The ejective time, quantity and germination rate of ascoporaes between the two habitats are different with sunshine. To satisfy the needs of sunshine, moisure and temperature can be raised the ejection and germination of ascorporae.
PURPOSE: To establish the culture of human iris pigment epithelial cells in vitro and study the freezing-state preservation and resusciation. METHODS: The iris pigment epithelial specimens from human eyes were cultured in vitro. Based on the cell-frozen principle, the cultured cells were collected, then frozen in liquid nitrogen and resuscitation. RESULTS: Cultured iris pigment epithelial cells were obtained. Under the inverted light microscope, primary cells appeared multigonal and arranged in monolayer, there were abundant pigment granules in the cytoplasm and the nuclei each of which contained 1 or 2 nuceoli wre relatively transparent. Under the transmission electron microscope, there were plenty of microvilli at the cell membrane and desmosomes present in the intercellular space. 6 groups of cells were frozen. The resuscitation exeriment was carried out for 4 times, every times being successful. All of the resuscitated rates were more than 90%. CONCLUSION: The human iris pigment epithelial cells were cultured in vitro successfully, they can also be frozen and resuscitated, which will be useful in studies of pathogenesis for some eye disease.
A new telemedicine system and its application are introduced in this paper. Many new technologies, such as multiteleconference, multibind of MODEM and ISP, are adopted, which greatly improve the performance of the system.
OBJECTIVE: To evaluate the hearing function in patients with hereditary progressive non-syndromic hearing loss. METHODS: Distortion product otoacoustic emissions (DPOAE) and pure tone audiometry were carried out in 52 individuals from a family with non-syndromic hearing loss and 15 persons with normal hearing. RESULTS: 1. Sensorineural hearing loss (SNHL) was found in 34 individuals of the family. Among these individuals, DPOAE was totally absent in 15 cases (29 ears) with pure tone average > or = 40 dB and low amplitude or absent middle to high frequencies in 12 cases (23 ears) with high frequency hearing loss but pure tone average < or = 35 dB. 2. Among 21 individuals (42 ears) with normal audiograms, DPOAE presented lower amplitude or absent high and middle frequencies in 12 individuals. CONCLUSION: DPOAE can be used in identification of subclinical pathologic alterations in the cochlea. This would be of particular value in early diagnosis and genetic consultation.
OBJECTIVE: To study the effect of 6A8 alpha-mannosidase expression on the proliferative response of human B cell 3D5. METHODS: Recombination of adeno-associated virus vector(rAAV) mediated delivery of sense 6A8 DNA or antisense 6A8 DNA into 3D5 cells, and monoclonal antibody 6A8 alpha staining and Con A binding assay for determination of the change of 6A8 alpha-mannosidase expression, MTT assay for proliferation detection of 3D5 cells driven by Staphylococcus aureus crude cell suspension formalin-fixed (SAC), lower molecular weight B cell growth factor (LMW-BCGF), or rIL-6. RESULTS: The expression of 6A8 alpha-mannosidase was enhanced in sense 6A8-transduced cells and reduced in antisense 6A8-transduced cells. In comparison with the wild type and the mock-transduced cells, the proliferative response of the sense 6A8-transduced cells to SAC stimulation was enhanced (P < 0.05). However, transduction with antisense 6A8 did not affect the response. In addition, transduction with either sense or antisense 6A8 had no effect on proliferation of 3D5 cells induced by LMW-BCGF or IL-6. CONCLUSION: The proliferative response to SAC stimulation was enhanced in the 3D5 cells with enhanced expression of 6A8 alpha-mannosidase. Either enhancement or reduction of 6A8 alpha-mannosidase expression had no effect on proliferation induced by LMW-BCGF or IL-6.
OBJECTIVE: To analyze the interactions between domains within the NH2- and COOH-terminal regions of presenilins. METHODS: The various constructions corresponding to NH2-terminal fragment (NTF) and COOH-terminal fragment (CTF) derivatives of presenilin 1 (PS1) and presenilin 2 (PS2) were generated by RT-PCR, and their interactions were assayed by yeast two-hybrid system. RESULTS: Domains within the NH- and COOH-terminal fragments of presenilins could directly interact with each other, and therefore form high molecular weight complex. The interaction site between domains within PS1 located at amino acid 361-447 of PS1 CTF, without the involvement of other partners. Similar interaction was not observed between PS11-360 and PS2341-448, PS2(1)-340 and PS1(361)-467. CONCLUSIONS: Intramolecular interaction between domains within the NH2- and COOH-terminal regions of presenilins may be critical to the folding and assembly of mature PS molecules.
OBJECTIVE: To investigate the abnormalities of the relative factors of pRb-p16 cell regulatory pathway in pancreatic adenocarcinoma. METHODS: Five strains of human pancreatic adenocarcinoma cell lines were analysed by PCR and single-strand conformation polymorphism (SSCP) for homozygous deletion and mutation of the p16 gene, respectively. The gene amplification of cyclin D1 was detected by Southern blot analysis and the protein expression of pRb gene was examined by Western blot analysis. RESULTS: Homozygous deletion of exon 1 were found in two cell lines and no mutation was found within exon 1 and exon 2 in five cell lines. Cyclin D1 gene amplification was observed in one cell line and all of the five cell lines showed hyper-phosphorylated pRb protein. CONCLUSION: These findings have demonstrated that there are abnormalities of pRb-p16 regulatory pathway in pancreatic adenocarcinoma cell lines, revealing the alteration of the p16 and cyclin D1 genes.
OBJECTIVE: To study the role of mitochondrial deficiency in the pathogenesis of neurodegenerative disease by investigating the energy metabolism in a sodium azide inhibited cytochrome-c oxidase SH-SY5Y Cell model. METHODS: Human neuroblastoma SH-SY5Y Cells were exposed to sodium azide, then mitochondrial complex IV activity was assayed by microassay method; cell viability was measured by Thiazolyl blue(MTT) method; mitochondrial membrane potential (MMP) was detected by confocal microscopy and flow cytometry. RESULTS: Cultured SH-SY5Y cells were exposed to 16-64 mmol/L sodium azide for 1 hour, the mitochondrial complex IV activity decreased dose-dependently. MTT absorbance decreased does- and time-dependently in cultured nerve cells treated by 16-128 mmol/L sodium azide for 1-8 hours. After the treatment of 16 mmol/L sodium azide for 1 hour, both the fluorescence intensity of MMP and normal cell events reduced. Decrease of MMP was significant especially in cell processes. CONCLUSION: Sodium azide induced the impairment of mitochondrial energy synthesis in the cultured nerve cells which is an important cause in cell death.
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Nickel salicylates complexes were synthesized with the rheologic phase reaction method. The composition of these complexes were confirmed by elemental analysis, TG and IR, the principal infrared absorption peaks were assigned for the region 4,000-400 cm-1. The IR spectra indicated that a hydroxyl group on Ni atom was occurred and so absorption peaks of hydroxyl group were shifted obviously to higher frequency in nickel monosalicylates.
Micro amounts of calcium and magnesium in saturated high purity sodium chloride solution were determined by flame atomic absorption spectrometry after the preseparation of calcium and magnesium from matrix solution through ion-exchange resin column filled with model 401 chelate resin. The parameters and operating conditions of the preseparation of calcium and magnesium from matrix solution were studied by orthogonal optimization process. The relative standard deviations of this method were 6.5% and 5.5% for calcium and magnesium, respectively. The recoveries were 99% and 94% for calcium and magnesium, respectively.
OBJECTIVE: A 3D geometric simulation of mandible with dental arch from CT has been obtained in this study. METHODS: This process uses automatic system assisted with interactive action to get 2D contour data from CT images,then 3D wireframe model and solid model were obtained by using CAD/CAM software Pro-E(USA) and DELCAM(UK). RESULTS: 3D solid model of mandible with dental arch were presented which can be fully edited. CONCLUSION: This model can be applied to further educational and clinical researches such as RP,biomechanics simulation in prosthetic dentistry.The processes of simulation has wide applications in clinical practice of dentistry and dental education.
OBJECTIVE: Based on 3D reconstruction data from CT scanning, a solid model of mandible with dental arch is obtained via a rapid prototype machine using LOM method. METHODS: 3D reconstruction data is transferred to STL file using software of Delcam(UK),which will be fed to Magics RP software for detection and rebuilding. Reproduction of the papery model of mandible with dental arch is then performed with highly geometric similarity. RESULTS: The RP model of mandible with dental arch is obtained. CONCLUSION: Accuracy of the reproduction model meets the demands of students in prosthetic dentistry,which gives the possibility of computer aided design of prosthetic dentistry based on 3D solid model.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
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The ability to directly sequence peptides from biological cells using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with postsource decay (PSD) and collision-induced dissociation (CID) fragment ion mass analysis is explored. Three different sample preparation methods are described for sequencing peptides in tissue samples and in single neurons from the invertebrate model Aplysia californica. To characterize peptides from the atrial gland, MALDI-PSD/CID is applied directly to a tissue blot covered with the matrix alpha-cyano-4-hydroxycinnamic acid (CHCA). The resulting fragment ions combined with database searching confirm the structure of several novel peptides encoded by egg-laying hormone genes. Moreover, MS profiling of a single unidentified neuron detects peptides with molecular weights of myomodulins C and E; this assignment is confirmed using MALDI-PSD with the matrix 2,5-dihydroxybenzoic acid (DHB). DHB does not always provide adequate fragmentation for PSD experiments; therefore, a unique dual-matrix sampling method, employing both DHB and CHCA, is developed to directly sequence a decapeptide from a single cerebral ganglion B cell. Mass accuracy of fragment ions from cellular samples is typical for the instrument employed and is not deleteriously affected by the morphology and complexity of the samples.