Biomedical subjects

Y Guo

Publications and source records attributed to Y Guo.

At least 307 records · Page 17Linked to original sources

PubMed1999

[Construction of DNA vaccine including a chimeric gene encoding Cysticercus cellulosae antigen and porcine interleukin-4].

AIM: To construct a fusion expression vector for DNA vaccine including porcine interleukin-4(IL-4) and antigen cC1 to enhance the protective immunity of Cysticercus cellulosae antigen cC1. METHODS: The cDNA fragments encoding porcine IL-4 and cC1 were amplified respectively by PCR and the fused. The obtained chimeric gene IL-4cC1 contained a synthetic linker of ten amino acids and the sequence surrounding its 5' AUG initiatory codon was changed to optimized translational initiation. RESULTS: Identified by restriction enzyme analysis, an insert fragment of 1.5 kb was demonstrated. It had the same sequence as reported and designed by DNA sequencing analysis. CONCLUSION: A fusion expression plasmid containing porcine IL-4 and cC1 was constructed.

Animals↗

PubMed1999

[Research of experimental fistula stimuli vestibule evoked response].

OBJECTIVE: To investiqate a way of stimulation for experimental vestibul evoked response. The artificial fistula of right upper semicircular canal was made in 12 guineapig. METHOD: Using a fistula stimuli probe device designed specially. RESULT: We obtain a potential consisting of 3-4 positive waveforms. We called it the fistula stimuli vestibule evoked response (FsVeR). They had a coincide character. The response disappeared when the animal died. The cervical spinal section, orbital removal and facial nerve removal had little effects to FsVeR. When severe inner ear damage produced by Gentamycin injection, the potential disappeared. The potential disappeared but ABR were existed. When the upper semicircular canal and its nerve damage. The noise screen had a little affection to FsVeR. CONCLUSION: These results indicated that FsVeR was mainly originated from the vestivbule system. The development of this recording technique provides a new method and maybe has important value for vestibule experimental research work.

Acoustic Stimulation↗

PubMed1999

[Character identification of 12 kinds of pilose antler medicinal materials].

In this paper, commercial medicinal materials of 12 kinds of pilose antler, Cervus nippon, C. elaphus, C. albirostris, C. unicolor, C. eldihainanus, C. timorensis C. porinus, Dama dama, Rangifer farandus, Alces alces, Elaphurus davidianus, Capreolus capreolus were compared and identified. A key and simple character illustration were listed.

Animals↗

PubMed1999

The preliminary study of glucocorticoid receptor gene in Chinese patients with glucocorticoid-induced glaucoma.

BACKGROUND: To study the glucocorticoid receptor (GR) and the associated gene regulation in the pathogenesis of glucocorticoid-induced glaucoma (GIG) in Chinese patients. METHODS: The trabecular cells of normal individuals and patients with GIG were cultured in vitro. By using polymerase chain reaction (PCR), gene fragments on GR DNA binding sites of trabecular cells were amplified. The product was detected by gel electrophoresis. RESULTS: The trabecular cells were cultured successfully in normal individuals and patients with GIG in vitro. A single PCR product was obtained in both two groups with the same size of 545 base pairs. CONCLUSION: There is not any difference in gene on the GR DNA binding sites between normal individuals and patients with GIG. The results suggest the difference in mRNA or other functional genes.

Binding Sites↗

PubMed1999

Differentiation of embryonic stem cells into neurons and retina-like structure in nude mice.

PURPOSE: To investigate the intraocular growth and biological characteristics of mice embryonic stem cells in nude mice. METHODS: Murine embryonic stem cells (D3 cell line) were cultured and maintained in an undifferentiated state in vitro, then transplanted into the anterior chamber of nude mice. Mophological and immunohistochemical examinations were implemented. RESULTS: Two to three days after transplantation, yellow-white floating granules, sheets and masses were seen inside the anterior chamber and vitreous cavity, and enlarged gradually. 14-20 days later, the mice were executed. Morphological examination showed that there were undifferentiated cells and some round or polygonal differentiated cells in anterior chamber and vitreous cavity. The morphology of these differentiated cells were similar to that of the retina. The cells were highly positive in NSE staining. CONCLUSION: The transplanted embryonic stem cells could grow in the eyes of nude mice with tendency to differentiate into neurons and retina-like structure.

Animals↗

PubMed1999

The study of influencing factors on the growth characters of Sprague-Dawley rat retinal neurons in vitro.

PURPOSE: To investigate the influencing factors in culturing Sprague-Dawley (S-D) rats retinal neurons in order to lay foundation for further experimental research. MATERIALS AND METHODS: Retinal cells were plated on plastic plates and coverslips coated with poly-l-lysine or ethylene imine polymer for primary culture. The cultured cells were divided into following groups: 1. Culture medium changed every 2 to 3 days vs changed only once; 2. Cytosine arabinoside (Ara-C) added to the culture medium vs not added. The cells were observed and pictured under inverted phase contrast microscope. The cells were identified through immunocytochemistry. RESULTS: The immunofluorescence showed that most of the cultured cells were neurons, among them were a few retinal ganglion cells. In the cultured group of which substrata coated with poly-l-lysine and culture medium added with Ara-c, the neurons intended to aggregate into clusters with relatively straight neurites. In the group of which substrata coated with ethylene imine polymer and medium added with Ara-c, the neurons grew dispersively with bent neurites. Both of them survived for 2 to 3 weeks. The cells which plated in the medium not added with Ara-c did not aggregate into clusters and survived longer than 4 weeks. In the group of which medium changed several times, the survival time of neurons was shorter than that in the medium changed only once. CONCLUSIONS: The retinal neurons plated on the substrata coated with ethylene imine polymer are easy to observe because of its dispersive growth. It is not favorable for the growth of the neurons by changing culture medium many times. Ara-c may possibly have side effect on the growth of retinal neurons.

Animals↗

PubMed1999

Corrective change of retinal thickness measured by optical coherence tomography and histologic studies.

PURPOSE: To evaluate the correlation of retinal thickness between optical coherence tomography (OCT) images and histologic slides. METHODS: Retinal thickness was measured in 16 rabbit retinal histologic slides. The same eyes had been previously measured by OCT for the comparison of results between two methods. Retinal thickness of each OCT image section was measured using both the manually assisted (requiring localization of reflectivity peaks by observer) and automated modes of the computer software. RESULTS: Retinal thickness measured by OCT demonstrated a high degree of correlation with retinal histologic study. The automated method (Cc = 0.66, P < 0.01) was less reliable than the manually assisted one (Cc = 0.84, P < 0.001). The former had an error in 95% confidence interval, ranged between -0.71 and 11.09 microns. The latter had a less error, ranged from -2.99 to 5.13 microns. CONCLUSION: OCT can quantitatively measure the retinal thickness. However, automatical identification of the reflective boundaries by computer may result in errors in some cases. To measure the retinal thickness by manually assisted mode can increase the accuracy.

Animals↗

PubMed1999

New management of malignant glaucoma by phacoemulsification with posterior chamber foldable intraocular lens implantation.

OBJECTIVE: To investigate the feasibility of phacoemulsification with posterior chamber foldable intraocular lens implantation in the management of malignant glaucoma. PATIENTS AND METHODS: Fourteen patients with malignant glaucoma diagnosed in the Department of Glaucoma were enrolled in the study. 12 patients developed malignant glaucoma after filtration surgery. 1 developed after peripheral iridectomy. 1 patient developed malignant glaucoma without any clear cause. Cataract phacoemulsification was performed. Posterior chamber intraocular foldable lens was implanted in 10 cases of patients. RESULTS: All 14 patients were cured with normal intraocular pressure, normal anterior chamber depth and increased visual acuity. CONCLUSION: Phacoemulsification with posterior chamber foldable intraocular lens implantation is a good alternative in treating malignant glaucoma.

Aged↗

PubMed1999

Modification of isolation and culture of human retinal pigment epithelial cells.

PURPOSE: To modify the isolation of human retinal pigment epithelial (RPE) cells and to increase the purification and production of cultured RPE cells. METHODS: The human eyecups were fixed on a rubber holder. After digestion by trypsin, RPE cells were collected, then cultured and identified by morphology, immunohistochemistry and electron microscopy. RESULTS: The cultured RPE cells grew actively in the early stage with transparent nucleus and abundant melanin particles in cytoplasm. These cells were positive in DOPA oxidase reaction and in anti-pancytokeratin antibody staining. Cellular microvilli and tight junctions could be seen through transmission electron microscopy. CONCLUSION: We developed a rubber holder to fix the eyecup. Using this holder, more and purer cultured RPE cells can be obtained. These cultured RPE cells are similar to those in vivo in morphology and immunohistochemical staining.

Cell Separation↗

PubMed1999

[Nucleotide sequence of A/Goose/Guangdong/2/96 (H5N1) virus M and NS RNA].

OBJECTIVE: To determine the nucleotide sequences of M and NS genes of A/Goose/Guangdong/2/96(H5N1) virus and also to compare them with the sequences of A/HK/156/97(H5N1) strain for revealing the relationship between the two viruses, as well as for setting up a solid base for studying M and NS genes of influenza A viruses in the future. METHODS: Virion RNA was transcribed into cDNA by reverse transcriptase, cDNA was amplified by PCR, the products of PCR were purified. Afterward, RNA sequence analysis was performed by the dideoxynucleotide chain termination method using synthetic oligodeoxynucleotide primers. RESULTS: The segment length of A/Goose/Guangdong/2/96(H5N1) virus RNA 7 is 1,027 nucleotides. It codes M1 (252 amino acids) and M2 (97 amino acids) proteins. However, the segment length of RNA 8 of A/Goose/Guangdong/2/96(H5N1) virus is 890 nucleotides coding NS1 (230 amino acids) and NS2 (121 amino acids) proteins. The amino acid sequence homologies of M1, M2, NS1 and NS2 protein molecules between A/Goose/Guangdong/2/9(H5N1) and A/HK/156/97 (H5N1) viruses are 97.6%, 92.8%, 65.7% and 76.9%, respectively. CONCLUSION: The lengths of A/Goose/Guangdong/2/96(H5N1) virus RNA 7 and RNA 8 and 1,027 are 890 nucleotides, respectively. These two RNA segments belong to those of avian influenza A virus. The A/HK/156/97(H5N1) virus RNA 7 and RNA 8 segments are not derived from those of A/Goose/Guangdong/2/96(H5N1) virus directly.

Amino Acid Sequence↗

PubMed1999

[Protective effect of poly DL-aspartic acid on ototoxicity of gentamicin].

OBJECTIVE: To observe the protective effect of poly DL-aspartic acid (PAA) on ototoxicity of gentamicin (GM). METHODS: Fifty F-344 rats were divided into four groups, GM only PAA + GM, PAA only and saline control. ABR thresholds at different frequencies were measured at different times and hair cell losses were numerated. Two-dimensional diffusion assays in the culture medium were performed to evaluate the effect of PAA on the antimicrobial activity. RESULTS: Eighteen days after the treatment, ABR thresholds at 10 kHz and 8 kHz as well as hair cell losses in the GM-treated group showed significant differences as compared with other three groups (P < 0.01). CONCLUSION: PAA had the protective effect against the cochlear ototoxicity of GM without decreasing its antimicrobial activity.

Animals↗

PubMed1999

[Floating culture of human nasal glandular cells].

OBJECTIVE: To establish a floating cultural model of human nasal glandular (HNG) cells. METHODS: HNG cells were cultured on floating collagen gels. RESULTS: Cultured HNG cells incubated with monoclonal antibody for cytokeratin stained positively. After two-week culture, the cells stained blue by AB-PAS staining. Transmission electron microscopy showed that the cells exhibited numerous microvilli on their surfaces and had numerous secretary granules. They were well polarized and interconnected by junctional complexes. Cultured HNG cells possessed typical characteristics of normal epithelium. CONCLUSION: The floating cultural model of HNG was successfully established.

Cell Culture Techniques↗

PubMed1999

[Morphological observations of the medial olivocochlear efferents in gerbils with chronic gentamicin ototoxicity].

OBJECTIVE: To determine the possible involvement of the medial olivocochlear efferents (MOC) in chronic aminoglycoside ototoxicity, the morphological changes of the MOC efferents in the cochlea of Mongolian gerbils and their correlations with the impairment of the outer hair cells (OHCs) were observed. METHODS: The animals were given gentamicin in a dose of 150 mg/kg a day for 10 days. The distributions and densities of the MOC efferents were examined using the modified histochemical staining for acetylcholinesterase (AChE) and the numbers of OHCs were numerated with toluidine blue and Ehrlich haematoxylin staining on the surface preparation. RESULTS: Significant damage to the MOC fibers and terminals as well as OHCs was noted in the basal turn of the cochlea, especially in those animals examined in 7th and 11th week after the gentamicin administration. The site of the greatest impairment of OHCs was consistent with that of the MOC efferents. CONCLUSION: The results suggested that damage to the MOC efferents might play an important role in gentamicin-induced impairment of OHCs.

Animals↗

PubMed1999

[Sodium channels in the apical membrane of human nasal epithelial cells].

OBJECTIVE: To study the physiological properties of sodium channels in the apical membrane of human nasal epithelial cells. METHODS: Serum-free cultured nasal epithelial cells of human inferior turbinate from obstructive sleep apnea syndrome patients on collagen gel-coated membranes at an air-liquid interface were studied by patch clamp technique. RESULTS: In cell-attached patches, a typical single channels current was recorded, their conductance was 21.09 pS, the reversal potential was -50.96, and 77.78% of them < -40 mV. Permeability ratio PNa/PK > 5.80. In the presence of 10(-4) mmol/L amiliride in the pipette, the incidence of sodium channels decreased from 26.67% to 5.13%. It revealed that a population of channels were inhibited by amiloride. Ca2+ did not influence the incidence of sodium channels(P > 0.05), there were no obviously association between voltage and the open probability of the channels. CONCLUSION: On Na+ channels in cell attached patches of human nasal epithelial cells, most of channels are amiloride-sensitive and selective Na+ over K+; The channels were not activated by extracellular Ca2+, but the open probability of them were voltage-independence.

Adult↗

PubMed1999

[The significance of matrix metalloproteinases expression in nasal polyps].

OBJECTIVE: To explore the role of matrix metalloproteinases (MMPs) in nasal polyp formation. METHODS: The expression of MMP9, MMP2 and MMP3 was studied in 32 nasal polyps by immunohistochemical method. RESULTS: MMPs could not be detected in all samples of normal mucosa. In nasal polyp tissue, MMP9 was observed epithelial in cells, inflammatory cell and blood cells, MMP2 was detected in fibroblasts, epithelial cells and inflammatory cells, and MMP3 was detected in inflammatory cells and epithelial cells. Compare to normal mucosa, MMP9, MMP2 and MMP3 was over expressed in their positive cells of polyp. The expression of MMP9 was higher than that of MMP2 and MMP3 in nasal polyp tissue (P < 0.01). CONCLUSION: MMP9, MMP2 and MMP3 were strongly correlated with nasal polyp formation. They cause pathological changes in nasal mucosa and MMP9 may play the most important role among them.

Adolescent↗

PubMed1999

[The thermodynamic molar absorptivity of coordination color reaction of indium(III) with 4,5-dihydroxybenzene-1,3-disufornic acid].

The thermodynamic molar absorptivity of complex formed by 1:1 coordination color reaction of tiron with highly charged cation In3+ has been measured spectrophotometrically at 20.0+/-0.1 degrees C, using NaClO4 as supporting electrolyte. The influence of å on linear relation between molar absorptivity and ionic strength has been investigated. At å = 6.5, the thermodynamic molar absorptivity lg epsilon(o) was found to be 3.69.

English Abstract↗

PubMed1998

[Study on toxicity of P-Dichlorobenzene].

The authors studied the toxicity of P-Dichlorobenzene(P-DCB). The results showed that the toxicity of P-DCB was low. It has no accumulation (K > 5), no eye irritation and no skin sensitization effects. But light skin irritation effect was observed. In sub-acute inhalate exposure, damage on the function of liver and kidney was not observed. Genotoxic tests showed that tests in s. typhimurium strains TA98 and TA100 did not show any mutagenic potential. In Chinese hamster lung fibroblast CHL cell test system, it did not cause chromosomal aberrations.

Animals↗

PubMed1998

Proto-oncogene PML controls genes devoted to MHC class I antigen presentation.

Fragments of foreign antigens associated with class I molecules of the major histocompatibility complex (MHC) are presented at the cell surface to elicit an immune response. This presentation requires the coordinated expression of several genes contained in the MHC, including those encoding the MHC class I heavy chain, the proteins LMP-2 and LMP-7, which are involved in the proteasomal degradation of cytosolic antigens into peptide fragments that are destined for association with MHC class I molecules, and TAP-1 and TAP-2, which transport these fragments across the membrane of the endoplasmic reticulum at the start of their journey to the cell surface. In many virus-transformed cell lines and spontaneous tumours, these genes are simultaneously repressed. However, the key factor(s) that are essential for their expression and repression have not been identified. Here we report that the proto-oncogene product PML induces expression of LMP-2, LMP-7, TAP-1 and TAP-2 in an MHC-class I-negative, recurrent tumour, leading to the re-expression of cell-surface MHC in tumours and to rejection of the tumours. PML also regulates MHC expression in untransformed fibroblasts. We conclude that malfunction of PML may enable a tumour to evade the immune defence of its host.

3T3 Cells↗