Biomedical subjects

M Yu

Publications and source records attributed to M Yu.

At least 91 records · Page 5Linked to original sources

PubMed2001

Outcome of 2,284 cases with acute traumatic brain injury.

OBJECTIVE: To analyze the prognosis of 2284 cases with acute traumatic brain injury and discuss possible methods to improve the outcome of head injuries. METHODS: The relationship between trauma cause, trauma severity and management and patient's outcome was retrospectively analyzed. RESULTS: Good recovery was achieved in 60.20%, moderate disability was 13.22%, severe disability 15.24%, vegetative status 0.31% and mortality 11.03%. The mortality was 1.07% in cases with GCS 15-13, 2.47% in cases with GCS 12-9, 13.29% in cases with GCS 8-6, and 57.4% in cases with GCS 5-3. CONCLUSIONS: To prevent hypoxia, remove intracranial hematoma as soon as possible, use standard large traumatic craniotomy and apply mild hypothermia may be useful means for improving the outcome of severely head injured patients.

Acute Disease↗

PubMed2001

[The clinical effect of non-penetrating trabecular surgery with reticulated sodium hyaluronate implant for treatment of primary open-angle glaucoma].

OBJECTIVE: To evaluate the clinical effect of non-penetrating trabecular surgery (NPTS) with reticulated sodium hyaluronate implant in primary open-angle glaucoma (POAG). METHODS: NPTS with reticulated sodium hyaluronate implant was performed on 27 eyes of 25 patients with POAG. The procedure consisted of excising a deep scleral tissue including the external wall of the Schlemm's canal under a scleral flap without opening the anterior chamber, as the inner wall of the canal was left in place. Then placing a 3.0 mm x 4.5 mm x 0.5 mm or 3.5 mm x 3.5 mm x 3.5 mm reticulated sodium hyaluronate implant was placed under the flap, so that the aqueous humor may filter through the thin layer of trabeculocorneal membrane spontaneously without forming a flat chamber. The postoperative intraocular pressure (IOP), inflammation and filtering bleb were analyzed. All of patients undertook ultrasound biomicroscopy (UBM) and gonioscopy to evaluate the surgical site on the postoperative 2 weeks, 3, 6 and 9 months. The mean follow-up was (6.61 plus minus 2.47) months. RESULTS: The IOP decreased from a mean preoperative value of (26.36 +/- 9.02) mm Hg (1 mm Hg = 0.133 kPa) to a mean postoperative value of (14.18 +/- 3.51) mm Hg (t = 6.875, P < 0.05). The number of anti-glaucomatous medications, topical or systemical, was reduced from (2.96 +/- 1.43) sorts preoperatively to (0.77 +/- 1.07) sorts postoperatively. The visual acuity remained stable (no statistical difference with chi(2) test). Six eyes had elevated IOP after operation and were controlled by eyedrops or trabecular puncture with ND: YAG laser. A slight hyphema occurred in 4 eyes with small puncture during operation. The complications such as flat chamber, inflammation and choroidal detachment were not observed. The UBM showed that the sodium hyaluronate implant degraded and a transparent liquid space existed under the scleral flap in all of patients at postoperative 3 months. The gonioscopy showed that at the surgical site the thinner and semitransparent trabecular membrane and changes of a transparent cavity could be seen in 23 eyes. In the other eyes, at the site the trabecula was translucent. The filtering blebs were formed in 8 eyes. CONCLUSION: Non-penetrating trabecular surgery with reticulated sodium hyaluronate implant can effectively lower the IOP and reduce the sorts of anti-glaucomatous medications. The visual acuity may remain unchanged, and no serious complications commonly seen in the traditional trabeculectomy occur. The procedure is a new simple and effective one for the treatment of POAG.

Adolescent↗

PubMed2001

[Cloning and expression of heptad repeat regions of the Newcastle disease virus fusion protein].

Two heptad repeat regions (HR1, HR2) from F clone of the virulent and avirulent NDV were cloned, expressed with vector pGEX-6p-1 in E. coli BL21 (DE3), and purified the fusion protein by Glutathiones Sepharose 4B Column. After cleaved by precission protease, the desired protein was purified by Glutathione Sepharose 4B Column and high temperature. Purified HR1 and HR2 were analyzed by Mass spectrum, the results shows that the Molecular Weights of HR1 and HR2 of virulent NDV are 7103 and 6301, and the Molecular Weights of HR1 and HR2 of avirulent NDV is 7107 and 6309.

Base Sequence↗

PubMed2001

[Examination and evaluation of lipopolysaccharide binding protein in serum of patients with chronic hepatitis, severe hepatitis].

OBJECTIVE: To observe the variability of lipopolysaccharide binding protein (LBP) in patients with chronic hepatitis and severe hepatitis. METHODS: Using ELISA the authors detected the serum LBP of 71 patients including 16 with chronic hepatitis, 15 with post hepatitis cirrhosis, 12 with severe hepatitis and 17 healthy controls. RESULTS: The serum LBP of chronic liver disease group was 35 166.25 micrograms/L, which was higher than that of healthy control group (18 590.00 micrograms/L). The serum LBP of chronic hepatitis and cirrhosis patients was higher than that of severe hepatitis cases. These differences were significant. The serum LBP had positive correlation with prothrombin activity (PTA) (r =0.395 8,P <0.01), while it had no significant correlation with serum ALT and total bilirubin levels (r =0.164 5,0.189 4, respectively, P <0.05). CONCLUSIONS: Serum LBP could be used as an index for predicting liver function compensation.

Acute-Phase Proteins↗

PubMed2001

[Comparative study on self-made denture adhesive paste and fixodent in improving chewing efficiency of dentures].

OBJECTIVE: The objective of this study is to test whether the self-made denture adhesive paste can improve the chewing efficiency of complete denture. METHODS: The abilities to improve chewing efficiency of two different materials, including self-made and Fixodent denture adhesive paste, will be investigated in this experiment. 24 patients were randomly selected, who wore complete dentures or mucous membrane supporting removable partial dentures because of the loss of most teeth. Identical test method was adopted by chewing peanuts. By employing a spectrophotometer, the absorbency values of chewed peanuts suspension before and after the use of self-made denture adhesive pasties were measured, and the differences could be obtained by calculation. The differences indicated the relationship between denture adhesive paste and chewing efficiency. Then the results of two materials would be compared and analyzed. RESULTS: The statistical analysis revealed that both self-made denture adhesive paste and Fixodent resulted in remarkable difference in the absorbency values before and after use (P < 0.01), however, there is no obvious difference in improving the chewing efficiency between the self-made and Fixodent denture adhesives (P > 0.05). CONCLUSION: The self-made denture adhesive paste is the same as Fixodent in improving the chewing efficiency of denture.

Dental Bonding↗

PubMed2001

[Studies of the resistance of the recombinant alphavirus RNAs containing dengue-2 PrM gene to virus infection].

The amplified PrM gene of dengue-2 virus was cloned into the downstream SP6 promoter-pSFV vector and the recombinant plasmid (pSF.rM2) DNA which contained sense- or antisense-PrM gene, was selected. pSF.rM2 DNA and helper DNA linearized by the enzyme SpeI digestion were both transcribed in vitro into recombinant RNAs which contained the capping analog on the 5'-end and contaansfected into BHK cells by electroportation. The the transfected host cells were challenged with dengue-2 virus and the resistant efficiency of recombinant virus RNAs containing sense- or antisense-PrM gene to virus infection were observed, respectively. The recombinant plasmids (pSFV-PrM) containing sense- or antisense-PrM gene were selected with determination of the nucleotide sequence. The recombinant virus particles were obtained with recombinant RNA and helper RNA co-transfected into BHK cells. Host cells transfected with antisense-PrM RNA derived complete resistance to dengue-2 virus replication and the efficiency was higher than that of the recombinant virus RNA containing sense-PrM gene.

Alphavirus↗

PubMed2001

[The ocular hypotensive effect and safety of 0.2% brimonidine].

PURPOSE: To study the ocular hypotensive efficacy and safety of 0.2% Brimonidine when used in chinese people. METHODS: Using randominzed parallel group control study, 0.2% Brimonidine twice a day or 1% Carteolol twice a day was applied in patients with primary open angle glaucoma or ocular hypertension for three months. RESULTS: The results showed that 0.2% Brimonidine and 1% Carteolol both have good ocular hypotensive efficacy. There was no significant difference between them. 0.2% Brimonidine did not produce significant changes in pupil size and heart rate. Change in blood pressure was not clinically significant. Six patients with 0.2% Brimonidine had drowsiness. Two patients had dry mouth. One patient had ocular burning. CONCLUSION: Our results suggested that 0.2% Brimonidine would be a stable and effective antiglaucoma medicine with good tolerance. Thus, 0.2% Brimonidine should be the main choice of medical therapy for primary open angle glaucoma and ocular hepertension.

Adrenergic alpha-Agonists↗

PubMed2001

Histopathological study of trabeculum after excimer laser trabeculectomy ab interno.

PURPOSE: To study the clinical manifestations and histopathologic changes of trabeculum after excimer laser trabeculectomy ab interno (ELT), and to investigate the mechanisms of ELT in reducing intraocular pressure. METHODS: ELT was performed on ten rabbit eyes and postoperative responses were documented. Corneoscleral tissue samples were harvested consecutively each week until the 5th postoperative week and these samples were examined under light and electrical microscopy. RESULTS: Mild stimulation signs were present postoperatively in nine of ten eyes, but no serious complications were experienced. Obvious inflammation was observed in one rabbit eye as a result of iris damage during the surgical manipulations. Local fractures on the trabecular meshwork and openings into Schlemm's canal were detected in all tissue samples under light microscope. Mitochondria were found to be turgescent and dilated like vacuoles and endoplasmic reticula were found to be dilated under electrical microscope in the early postoperative period. Later, all trabecular cells returned normal and no fibroblast cells were ever detected. CONCLUSIONS: Permanent openings through trabecular meshwork into the inner wall of Schlemm's canal can be created with ELT. The outflow resistance of aqueous humor can be reduced with these openings and intraocular pressure can be controlled thereafter.

Animals↗

PubMed2001

Effect of 0.2% brimonidine on retinal blood flow.

PURPOSE: To analyze the effect of 0.2% brimonidine eye drops on retinal blood flow of patients with glaucoma. METHODS: Using self-control method and Heidelberg Retina Flowmeter (HRF), we examined the volume, flow and velocity of the superior nasal and temporal, the inferior nasal and temporal artery of retina at baseline and 2 hours after single instillation of 0.2% brimonidine. RESULTS: There were no significant changes in volume, flow and velocity of four vessels before and after the administration of 0.2% brimonidine. CONCLUSIONS: There are no significant ocular haemodynamic benefits associated with Brimonidine therapy to the glaucoma patients.

Adrenergic alpha-Agonists↗

PubMed2001

Motion perception of short-wavelength sensitive cones in glaucoma using random dots moving.

PURPOSE: To determine whether motion perception of short-wavelength sensitive(SWS) cones is capable of predicting primary open angle glaucoma(POAG) optic neuropathy. METHODS: Motion perceptions of SWS cones were isolated by Blue random dot stimulus displayed on the Yellow background, then the detecting displacement threshold of motion perception from SWS cone in POAG was measured, and compared with the age-matched normal group. RESULTS: The detecting displacement thresholds of motion perception from SWS cones in 8 sites of 15 degrees were all elevated in POAG compared with the normal group. CONCLUSION: These findings suggest that motion perception of SWS cones may reveal preclinical visual nerve damage in early POAG.

Adolescent↗

PubMed2001

[Cytotoxic effect of Acanthamoeba trophozoite on HeLa cells].

OBJECTIVE: To investigate the cytotoxic effect(CTE) on human cervix cancer HeLa cells induced by five strains of pathogenic free-living Acanthamoeba. METHODS: The cytotoxic effect of five isolates of Acanthamoeba on HeLa cells was investigated by light microscopy and MTT method. RESULTS: The photomicrographs of HeLa cells showed a sequence of cardinal morphological features of apoptosis when HeLa cells were exposed to Acanthamoeba in a time-dependent manner at a ratio of 1:1 for 12 h. MTT method showed more than 50% of tumor cells underwent cytolysis following exposure to A. lugdunensis trophozoites, and only 18% of cells treated with A. polyphaga underwent CTE. The CTE produced by A. lugdunensis and A. quina trophozoites was more rapid than the others, beginning as early as 6 h after coincubation and resulting in cytolysis by 72 h. CONCLUSION: These five strains of Acanthamoeba exhibit cytotoxic effects of varying degrees on HeLa cells, inducing apoptosis.

Acanthamoeba↗

PubMed2001

[Hydroxyapatite for experimental laryngotracheal reconstruction].

OBJECTIVE: The porous hydroxyapatite (HA) tubiform prosthesis was employed for reconstruction of large circumferential defect of the larynx and cervical trachea. The biocompatibility, bioactivity and biofunctionality of the HA prosthesis were evaluated, and the feasibility for laryngotracheal reconstruction was discussed. METHODS: Twelve healthy canines were used to establish the experimental models, a large portion of cricoid cartilage and upper ten-ring segment of cervical trachea were resected and substituted with a corresponding 5 cm HA prosthesis by end-to-end anastomosis. Six months later, the eight survival canines were sacrificed and the HA prostheses with surrounding tissues were removed. They were observed in decalcified sections by optical microscopy and scanning electron microscopy. RESULTS: Two canines died in the immediate postoperative period with unknown reason and another two deaths were attributed to obstruction caused by the complete dislocation of the HA prostheses owing to rupture of the sutures within three weeks after operation. Eight canines survived up to six months. The implanted HA prostheses were tolerated in all cases without any rejection and dislocation or shift. An excellent airway was obtained and no signs of dyspnea and suffocation were found though there were hypergranulation and scar formation occurred at the site of anastomosis. Morphologic examination revealed that collagen fibers, new vessels and plenty of cells penetrated deeply into the pores of HA, and occupying the outer two third of HA wall. HA prostheses were surrounded by connective tissues and anchored firmly to the neighboring tissues, including the ends of the cricoid and tracheal cartilage by ingrowths of cartilaginous tissue into the macropores of the HA. However, the luminal surface of HA prosthesis was not covered at all section levels by respiratory mucosa. CONCLUSIONS: The implantation of the porous HA tubiform prosthesis can maintain the normal respiratory function of the experimental canines, but the proliferating granulation and scar formation at the anastomotic site are questions still remained to be solved. To cover the inner surface of HA with the epithelial mucosa and then reduce the morbidity caused by scar and hypergranulation, some forms of allografts such as pedicled flaps and jejunal autografts will be deserved.

Animals↗

PubMed2001

[Comparative research on Seal & Protect for treatment of hypersensitivity of the dentine].

OBJECTIVE: Observation of clinical results in treatment of hypersensitive dentine with two kinds of drugs. METHODS: Seal & Protect was compared with conventional NaF method for the treatment of 120 teeth with typical hypersensitivity which were divided into two groups. RESULTS: The efficiency of Seal & Protect group was 96.67 % while that of NaF group 76.67%. There was significant difference between two groups. CONCLUSION: The safe, effective and good method was provided for treating the hypersensitive dentine by use of Seal & Protect.

English Abstract↗

PubMed2000

Modulation of the IL-10/IL-12 cytokine circuit by interferon-beta inhibits the development of epitope spreading and disease progression in murine autoimmune encephalomyelitis.

IFN-beta has been shown to be effective in the treatment of multiple sclerosis (MS). However, the primary mechanism by which IFN-beta mediates its therapeutic effect remains unclear. Recent studies indicate that under defined conditions, IFN-beta may downregulate DC expression of IL-12. We and others have shown that IFN-beta may also downregulate IL-10. In light of the recently proposed paradigm that an IL-10/IL-12 immunoregulatory circuit controls susceptibility to autoimmune disease, we examined the effect of IFN-beta on the development and behavior of the autoreactive T cell repertoire during experimental autoimmune encephalomyelitis (EAE), an animal model sharing many features with MS. SWXJ mice were immunized with the immunodominant p139-151 determinant of myelin proteolipid protein (PLP), and at onset of EAE were treated every other day with IFN-beta. After eight weeks of treatment, we assessed autoreactivity and observed no significant IFN-beta effect on splenocyte proliferation or splenocyte production of IFN-gamma, IL-2, IL-4, or IL-5 in response to the priming determinant used to initiate disease. However, in IFN-beta treated mice, the cytokine profile in response to the priming immunogen was significantly skewed toward an increased production of IL-10 and a concurrent decreased production of IL-12. Moreover, the in vivo modulation of the IL-10/IL-12 immunoregulatory circuit in response to the priming immunogen was accompanied by an aborted development of epitope spreading. Our results indicate that IFN-beta induces a reciprocal modulation of the IL-10/IL-12 cytokine circuit in vivo. This skewed autoreactivity establishes an inflammatory microenvironment that effectively prevents endogenous self-priming thereby inhibiting the progression of disease associated with epitope spreading.

Adjuvants, Immunologic↗

PubMed2000

Inhibition of CCR5-dependent HIV-1 infection by hairpin ribozyme gene therapy against CC-chemokine receptor 5.

CCR-5 is a major cellular coreceptor for R5 strains of HIV-1. Individuals carrying a homozygous 32-base-pair deletion in this gene are apparently healthy and are relatively resistant to HIV-1 infection. Since CCR5 appears to be dispensable for the host, but important for initial HIV-1 infection, CCR5 mRNA is an excellent therapeutic target for inhibiting HIV-1 replication via ribozyme knockout. We report here that hairpin ribozymes are able to reduce cellular CCR5 mRNA and cell surface CCR5 when stably introduced into PM1 cells by transduction with recombinant adenoassociated viral vector. The ribozymes effectively protect the cells from infection by R5 HIV-1 strains or non-syncytium-inducing clinical isolates commensurate with a reduction in CCR5 mRNA. These results suggest a novel gene therapy approach to preventing or slowing the disease progression of HIV-1 infection.

CCR5 Receptor Antagonists↗

PubMed2000

HEDJ, an Hsp40 co-chaperone localized to the endoplasmic reticulum of human cells.

Hsp40 co-chaperones, characterized by the presence of a highly conserved J domain, are involved in nearly all aspects of protein synthesis, folding, and secretion. Within the lumen of the endoplasmic reticulum, these chaperones are also involved in reverse translocation and degradation of misfolded proteins. We describe here the cloning and characterization of a novel Hsp40 chaperone, which we named HEDJ. Epitope-tagged HEDJ was demonstrated by confocal microscopy to be localized to the endoplasmic reticulum. Protease susceptibility, glycosidase treatment, and detergent solubility assays demonstrated that the molecule was luminally oriented and membrane-associated. In vitro experiments demonstrated that the J domain interacted with the endoplasmic reticulum-associated Hsp70, Bip, in an ATP-dependent manner and was capable of stimulating its ATPase activity. HEDJ mRNA expression was detected in all human tissues examined. Highly homologous sequences were found in mouse, Drosophila, and Caenorhabditis elegans data bases. These results suggest potential roles for HEDJ in protein import, folding, or translocation within the endoplasmic reticulum.

Adenosine Triphosphatases↗

PubMed2000

Identification of B94 (TNFAIP2) as a potential retinoic acid target gene in acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is characterized by a block to myeloid differentiation caused by expression of the fusion oncoprotein promyelocytic leukemia-retinoic acid receptor alpha (PML-RARalpha). The purpose of this study was to identify genes that are regulated in a PML-RARalpha-dependent fashion by retinoic acid (RA), because such genes may be integrally involved in APL pathogenesis and/or myeloid differentiation. A cDNA microarray approach was used to identify genes induced in response to RA in TF1 myeloid leukemia cells expressing PML-RARalpha (TF1-PR cells). The B94 gene (TNFAIP2; Unigene Hs.101382), originally identified as a tumor necrosis factor alpha-inducible gene in endothelial cells, was one of several genes found to be induced by RA specifically in TF1-PR cells, but not in TF1-neo (control) cells. The induction of B94 was most pronounced in cells expressing the PML-RARalpha short isoform and was negligible in cells that expressed a mutant PML-RARalpha protein containing a deletion of the PML coiled-coil domain. B94 induction by RA occurred within 1 h, did not require new protein synthesis, and was inhibited by actinomycin D, suggesting rapid transcriptional activation. B94 was also induced by RA in NB4, UF1, and HL-60 cells, but not in other hematopoietic cell lines tested, suggesting that its up-regulation by RA may be specific to cells that express PML-RARalpha or are at the late myeloblast or promyelocyte stage of myeloid development. A screen of bone marrow cells from normal donors or patients with acute myelogenous leukemia showed that B94 was highly expressed in normal marrow and in marrow from patients with acute myelogenous leukemia French-American-British subtypes M0-M2, but was repressed in marrow cells from APL patients. Treatment of APL blasts in vitro with all-trans-RA resulted in up-regulation of B94 mRNA. These results suggest that B94 plays a role in myeloid development and support the hypothesis that B94 is a target gene of PML-RARalpha in APL.

Bone Marrow Cells↗

PubMed2000

Photoelectron diffraction imaging for C2H2 and C2H4 chemisorbed on Si(100) reveals a new bonding configuration

A new adsorption site for adsorbed acetylene on Si(100) is observed by photoelectron imaging based on the holographic principle. The diffraction effects in the carbon 1s angle-resolved photoemission are inverted (including the small-cone method) to obtain an image of the atom's neighboring carbon. The chemisorbed acetylene molecule is bonded to four silicon surface atoms. In contrast to the C2H2 case, the image for adsorbed C2H4 shows it bonded to two Si surface atoms.

Journal Article↗