Biomedical subjects

Y Ling

Publications and source records attributed to Y Ling.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Expression of ras oncogene p21 product and proliferating cell nuclear antigen in liver cirrhosis and the correlation with liver cell dysplasia].

OBJECTIVE: To probe the role of ras oncogene p21 product, proliferating cell nuclear antigen (PCNA) and hepatitis B virus infection in the development of cirrhotic nodules, liver cell dysplasia and hepatocellular carcinoma (HCC). METHODS: S-P immunohistochemical technique was used to analyze the expression of p21, PCNA and HBsAg was studied in 30 cases of cirrhosis with HCC and 60 cases without HCC and 27 HCC cases. RESULTS: The positive rates for p21 in cirrhosis with or without HCC, and HCC tissue were 90%, 68.33%, and 62.96%, respectively. The positive rates for p21, PCNA and HBsAg in cirrhotic nodules with LCD were 92.45%, 73.59% and 64.92%, respectively, significantly higher than those without LCD (P<0.05). The incidence of p21 expression in hepatocytes was significantly higher in HBsAg- and PCNA positive cases than in negative ones (P<0.01). CONCLUSION: (1)The overexpression of p21 may play an important role in the early stage of the development of HCC; (2)LCD are precancerous cells which have the ability to initiate neoplastic growth and present a high risk of development of HCC especially combining HBV infection and the overexpression of p21 and PCNA. (3)The expression level of p21 in liver cirrhosis is related to HBV infection and the expression level of PCNA.

Adolescent↗

PubMed2000

Refractive errors and strabismus in premature Asian infants with and without retinopathy of prematurity.

AIM: In Caucasian populations, premature infants with retinopathy of prematurity (ROP) have been reported to have higher risks of developing refractive errors and strabimus. The purpose of this study is to evaluate the rate of these complications in Asian premature infants with and without ROP. METHODS: A retrospective case review of all premature infants referred to the Singapore National Eye Centre for ophthalmology screening. These included all neonates born earlier than 34 weeks gestational age and less than 1500 grams in birth weight. Standardized ophthalmology examinations including cycloplegic refraction and fundus examination at regular intervals were performed to determine the presence of ROP, refractive errors, squints and other ocular abnormalities until the patients were 3 years old. RESULTS: During 1991 to 1993, a total of 113 neonates were reviewed. Of these, 16 (14.2%) developed ROP. The risk of ROP was higher with lower birth weights and earlier gestational ages. At 1-year follow-up, the rate of myopia was 33.3% in babies with ROP compared to 3.7% in babies with no ROP (p < 0.001). The higher rates of myopia in babies with ROP remained with longer follow-up (33.3% and 25% in ROP group versus 3.4% and 3.8% in no ROP group, at 2 and 3 years respectively). There was no difference in rates of astigmatism or hyperopia throughout the 3 years. At 1 year follow-up, the rate of strabismus was 20% in the ROP group compared to 4.9% in the no ROP group (p = 0.07). However, this difference in rates of strabismus was not significant at 2 and 3 years of follow-up. CONCLUSION: Premature babies with ROP had higher rates of myopia and strabismus than those without ROP. Long-term follow-up of these babies is important for early detection and treatment of these ocular problems.

Asian People↗

PubMed2000

In situ RT-PCR detection of inducible nitric oxide synthetase gene expression in lung during endotoxemia in rabbits.

OBJECTIVE: To detect the location of inducible nitric oxide synthetase (iNOS) protein and mRNA in lung during endotoxemia in rabbits. METHODS: Northern blotting was performed before, 1 hour and 5 hours after the intravenous administration of lipopolysaccharide (LPS) in rabbits. Immunohistochemical analysis (IA), in situ hybridization and in situ reverse transcription-polymerase chain reaction (in situ RT-PCR) were also performed in lung sections. RESULTS: iNOS mRNA expression was found using Northern blotting in lung 5 hours after LPS injection, while it was not found in control. The positive stain was found only in macrophages in lung 5 hours after LPS injection by standard hybridization and IA; while by in situ RT-PCR, the amplification products were found in macrophages, airway epithelial cells, vascular endothelial cells, smooth muscle cells and leukocytes, in addition to macrophages distributed abundantly throughout the lung. The signal was absent in control or samples. CONCLUSIONS: Using an in situ RT-PCR technique, iNOS expression was not only observed in macrophages but also in many other kinds of cells in lung during endotoxemia in rabbits. This suggests that in situ RT-PCR is much more sensitive than in situ hybridization, and can be used to examine genes with low expression.

Animals↗

PubMed2000

[Role of peroxynitrite on airway hyperresponsiveness in asthmatic guinea-pigs].

OBJECTIVE: To study the formation and localization of peroxynitrite(ONOO-) in the lung tissues of asthmatic guinea pig and investigate the effects of ONOO- on airway hyperresponsiveness in asthma. METHODS: 18 guinea pigs were randomly divided into three groups of 6 each: (1) asthmatic group: guinea pigs were injected intraperitoneally with 1 ml of 10% ovalbumin. After 14 days, the animals were exposed to aerosol of 1% OVA; (2) aminoguonidine (AG) group: Animal immunization was the same as above, but 1 h before the animals were exposed to OVA aerosol, 10 mg/kg AG were injected intraperitoneally. (3) control group. The formation and localization of ONOO- in the lung tissues of the guinea-pig asthma model were observed by immunohistochemical detection. The effect of exogenous ONOO- on contractions of isolated tracheal strips of the guinea-pigs to various concentrations of histamine was examined. The damage of airway epithelial cells induced by ONOO- was observed by electron microscopy. RESULTS: There was strong immunoreactivity for nitrotyrosine (NT), a specific marker of ONOO- formation in vivo, in the airway epithelial cells and inflammatory cells surrounding small airways of the guinea-pigs with asthma. The AG group showed significantly decreased number of NT positive cells in the lung tissues. There were only a few NT positive cells in the control group. The responsiveness of isolated tracheal strips to various concentration of histamine(except 10(-8) mol/L) in the ONOO- 0.5 mmol/L group were significantly increased compared with the vehicle group. (P < 0.05, P < 0.01 or P < 0.001). The sensitivity of isolated tracheal strips to histamine in the ONOO- 0.5 mmol/L group were also increased compared with the vehicle group(P < 0.001). Electron microscopical observation of the airways revealed airway epithelial injury and shedding. CONCLUSION: There was ONOO- overproduction in airway epithelial cells of asthmatic guinea-pigs, which may contribute to airway epithelial damage and hyperresponsiveness in asthma.

Animals↗

PubMed2000

[Peroxynitrite mediated acute lung injury induced by lipopolysaccharides in rats].

OBJECTIVE: To explore the roles of peroxynitrite (ONOO(-)) in acute lung injury induced by lipopolysaccharides (LPS). METHODS: Nitrotyrosine (NT), a specific marker of in vivo ONOO(-) production, was detected with immunohistochemical technique in rat lung during endotoxin shock (LPS 5 mg/kg iv). Lung coefficient (LC), lung wet/dry weight ratio (W/D), the contents of water and Evans blue (EB) in lungs were measured after intratracheal insufflation of ONOO(-) with different doses. Monastral blue (MB)-labelled blood vessels and pathological changes in lungs were examined under a light microscope. RESULTS: After 2 or 6 hours of LPS intravenous administration, severe lung injury and positive signals of NT occurred with the latter located in the pulmonary macrophages, endothelia, subendothelial and muscular layers of the pulmonary artery. Administration of exogenous ONOO(-) caused dose-dependent increase in LC, W/D, ater and EB contents and in the number of MB-labelled blood vessels in rat lungs, together with significant pathological alterations such as diffuse alveolar collapse, capillary congestion in the septa and focal hemorrhage. CONCLUSION: In the early stage of endotoxin shock, severe lung injury and ONOO(-) production simultaneously exist, and exogenous ONOO(-) could induce significant dysfunction of microvascular endothelial barrier and lung injury, indicating that ONOO(-) generation in vivo may be involved in the pathogenesis of acute lung injury.

Animals↗

PubMed2000

[Optical coherence tomography applied for measurement of nerve fiber layer thickness in normal eyes].

OBJECTIVE: To evaluate the efficiency of optical coherence tomography (OCT) on quantifying retinal nerve fiber layer (RNFL) thickness and its reproducibility and investigate the difference of RNFL thickness between different groups. METHODS: According to their age, 152 eyes of 152 normal subjects were classified into six groups (such as 10 year, 20 year group, etc.), and investigated by OCT to measure the RNFL thickness. Each subject had circular scans around the optic nerve with a circle size of 3.46 mm. The RNFL thickness in different groups was analyzed. Intraclass correlation coefficient (ICC) in fifty eyes of 37 subjects was calculated. RESULTS: The mean RNFL thickness of 152 eyes was (90.09 +/- 10.81) microm, (140.27 +/- 10.60) microm, (85.03 +/- 14.01) microm, (140.27 +/- 9.70) microm and (114.11 +/- 6.08) microm (temporal, superior, nasal, inferior and the mean of the whole layer, respectively). Least significant difference (LSD)-t test was applied for multiple thickness comparisons of the mean and different quadrants among different groups. The results showed there were significant differences between the 60 year group and others except the 50 year group in temporal, superior, inferior quadrants and mean RNFL thickness (P = 0.000 - 0.019), and between each of 10 to 40 year groups and each of 50 to 60 year groups in the mean RFNL thickness (P = 0.000 - 0.026). ICCs of RNFL thickness measured by OCT were 0.78, 0.66, 0.64, 0.52 and 0.74 (temporal, superior, nasal, inferior and mean, respectively). CONCLUSIONS: Normal RNFL thickness can be measured accurately by OCT. There are some differences of RNFL thickness between different groups in normal persons.

Adolescent↗

PubMed2000

[Qualitative and quantitative measurement of retinal nerve fiber layer in primary open angle glaucoma by optical coherence tomography].

OBJECTIVE: To study the characteristics of optical coherence tomography (OCT) of primary open angle glaucoma (POAG), the difference of retinal nerve fiber layer (RNFL) thickness between normal persons and patients with POAG and the correlation between RNLF and visual field index. METHODS: Eighty-three cases (149 eyes) with POAG and 83 normal persons (150 eyes) were tested by OCT with circular scans around the optic nerve head (diameter = 3.46 mm) to observe the features of OCT. Statistic analysis was taken to compare the difference of RNFL thickness in quadrants and means between normal and glaucomatous group, and the difference of the thickness among the stages in POAG. Linear correlation and regression analysis was used to show the correlation between RNFL thickness and visual field index of 115 eyes of glaucomatous patients. RESULTS: The RNFL thickness measured by OCT in normal subjects is the thickest in superior and inferior quadrants, less in thickness in temporal and the thinnest in nasal quadrant. The curve showed double peaks. The RNFL of glaucomatous patients showed local thinness or defect, diffuse thinness or combination of the above two types. The mean RNFL thickness of normal group was (90.1 +/- 10.8) microm, (140.4 +/- 10.5) microm, (85.2 +/- 14.0) microm, (140.4 +/- 9.7) microm and (114.2 +/- 6.0) microm, of glaucomatous group was (56.0 +/- 31.0) microm, (81.0 +/- 36.3) microm, (47.1 +/- 27.5) microm, (73.4 +/- 38.4) microm and (64.6 +/- 28.8) microm in temporal, superior, nasal, inferior quadrant and the whole area, respectively. There is significant difference of RNFL thickness between the normal and glaucomatous group (P < 0.000), and there are significant differences among the three stages (early, developing and late) of glaucomatous group (P < 0.000). There is a close negative relationship between RNFL thickness and visual field index (r = -0.796, P < 0.0001). The sensitivity and specificity of RNFL thickness measured by OCT were 93.3% and 92.0%, respectively. CONCLUSION: OCT can quantitatively measure the RNFL thickness and show the difference of RNFL between normal persons and glaucomatous patients. The RNFL thickness gradually decreases while visual field defect increases with the development of POAG.

Adolescent↗

PubMed2000

[Study on the modulation of the inflammatory response in mouse hepatic vasculitis with sodium selenite and vitamin E antioxidants].

OBJECTIVE: To identify the regulatory effect of sodium selenite and vitamin E on complement-neutrophil-reactive oxygen species (ROS)-activation feedback mechanism-mediated inflammatory response. METHODS: The modulation of inflammatory response through the complement-neutrophil-ROS-activation feedback cycle with sodium selenite and alpha-tocopherol was verified both in vitro tests by chemiluminescense technique and complement fixation to detect ROS production and complement activation as well as in vivo mouse hepatic vasculitis models to test for the regulation of the inflammatory response. RESULTS: Convincing results were observed as the incidence of hepatic vasculitis dropped from 100% in the control group down to 20% in the seleno-antioxidant vitamin E treated group, indicating down regulation of the inflammatory response. CONCLUSIONS: Elucidation of the mechanism of complement mediated inflammatory response is a promising area for new therapeutic developments in the modulation of inflammatory response. This study suggests that selenium, vitamin E and other antioxidants may be the useful therapeutic agents in those disorders in which upregulation of inflammatory response has been implicated, e.g. ischemia, reperfusion injury, severe sepsis, rheumatoid arthritis and hepatitis.

Animals↗

PubMed2000

Study on stereometric parameters of optic nerve head of normal, big-cupped disk and glaucomatous eyes using Heidelberg retina tomograph.

PURPOSE: To investigate the difference of stereometric parameters of optic nerve head between the normal subjects and patients with big-cupped disk and primary open angle glaucoma(POAG). METHODS: Twenty-two cases (44 eyes) of normal subjects, 17 cases (34 eyes) of patients with big-cupped disk and 19 cases (37 eyes) of patients with POAG underwent Heidelberg Retina Tomograph (HRT) examination to get topography images and stereometric parameters of optic nerve head. RESULTS: The stereometric parameters of optic nerve head of the normal, patients with big-cupped disk and POAG were 1) disk area (mm2): 1.995 +/- 0.501, 2.407 +/- 0.661 and 2.248 +/- 0.498; 2) cup area (mm2): 0.573 +/- 0.264, 1.095 +/- 0.673 and 1.340 +/- 0.516; 3) cup/disk ratio: 0.257 +/- 0.095, 0.428 +/- 0.176 and 0.589 +/- 0.195; 4) rim area (mm2): 1.461 +/- 0.328, 1.312 +/- 0.418 and 0.905 +/- 0.409; 5) cup volume (mm3): 0.108 +/- 0.073, 0.347 +/- 0.346 and 0.550 +/- 0.394; 6) rim volume (mm3): 0.421 +/- 0.111, 0.378 +/- 0.225 and 0.224 +/- 0.189; 7) mean cup depth (mm): 0.225 +/- 0.070, 0.327 +/- 0.105 and 0.424 +/- 0.148; 8) maxim cup depth (mm): 0.630 +/- 0.178, 0.732 +/- 0.170 and 0.871 +/- 0.245; 9) cup shape measure (mm): -0.1867 +/- 0.09, -0.108 +/- 0.068 and -0.02 +/- 0.164; 10) mean RNFL thickness (mm): 0.290 +/- 0.053, 0.236 +/- 0.131 and 0.174 +/- 0.134; 11) RNFL cross sectional area (mm2): 1.419 +/- 0.332, 1.263 +/- 0.606 and 0.920 +/- 0.687. Besides, there was no difference of disk area between big cupped disk group and POAG group, no difference of rim area, rim volume and RNFL thickness between normal group and big cupped disk group, statistics analysis showed that there was significant difference of other stereometric parameters between the normal group and big cupped disk group or big cupped disk group and POAG group. CONCLUSIONS: There is certain difference of optic nerve head between the normal subjects and big-cupped disk and patients with POAG.

Adult↗

PubMed2000

[Quantitative measurement of macular thickness in normal subjects by optical coherence tomography].

OBJECTIVE: To measure the thickness of retinal neurosensory layer, retinal pigment epithelium (RPE) and choriocapillaris in normal subjects by optical coherence tomography (OCT). METHODS: Sixty normal subjects (120 eyes) were examined by OCT with 4 mm scanning length horizontally and vertically through foveola. The mean thickness of retinal neurosensory layer, RPE and choriocapillaris thickness in foveola, 175 microns and 750 microns to foveola, were calculated and compared. RESULTS: The mean thickness of retinal neurosensory layer is 146.34 +/- 8.58 microns in foveola; 155.58 +/- 10.20 microns in 175 microns to foveola and 252.98 +/- 14.07 microns in 750 microns to foveola. The mean thickness of RPE and choriocapillaris is 106.26 +/- 10.58 microns in foveola; 104.98 +/- 7.24 microns in 175 microns to foveola and 106.84 +/- 9.95 microns in 750 microns to foveola. The results show that there are no significant in mean thickness of retinal neurosensory layer in 175 microns to foveola in statistics, but there are differences in 750 microns to foveola between nasal and temporal or superior, inferior and nasal, temporal. The differences in mean RPE and choriocapillaris thickness of all sites are not significant. Correlative analysis showed that there is no correlation between retinal neurosensory layer, RPE and choriocapillaris thickness and age. CONCLUSION: OCT can accurately measure the thickness of retina in normal eyes and provide a subjective and Quantitative method to diagnose macular diseases.

Adolescent↗

PubMed2000

[Modulation of the inflammatory response through complement-neutrophil activation feedback mechanism with selenium and vitamin E].

To identify the regulatory effect of sodium selenite and vitamin E on the complement-neutrophil-reactive oxygen(ROS) activation feedback (CNAF) mechanism mediated inflammatory response, we detected ROS production and complement activation in vitro tests by chemiluminescence technique and complement fixation and recognized the regulation of the inflammatory response in vivo mouse vasculitis models of skin, lung, and liver. Convincing results were observed as both in vitro and in vivo experiments showing inhibition of CNAF mechanism with sodium selenite and vitamin E could effect the reduced ROS production and complement activation. The incidence (100%) for vasculitis in control group decreased to 20%-57% in sodium selenite and vitamin E treated groups. Elucidation of the ancillary mechanism of CNAF enhancing inflammatory response is a promising area for new therapeutic developments in the modulation of inflammatory response. As in a clinical approach, a remarkable therapeutic effect with sodium selenite was observed during an epidemic episode of epidemic hemorrhagic fever in Henan province. The mortality rate of fulminant cases was reduced from 100% of untreated control cases to 36.6% by treatment with sodium selenite. The results of present studies strongly suggest that antioxidants such as selenium and vitamin E as well as others like flavonoids can exhibit a novel anti-inflammatory action via this CNAF mechanism. It is expected in the future an increasing number of patients with severe infections or inflammatory disorders in which excessive complement activation and adverse ROS production have been implicated, e. g. ischemia-reperfusion injury, severe sepsis and diverse inflammatory vascular injuries like rheumatoid arthritis, hepatitis and inflammatory bowel diseases should benefit from this newer concept guided adjuvant therapies which make use of nutrient antioxidants like selenium, vitamin E and others.

Animals↗

PubMed1999

[A new approach for secondary deformities of unilateral cleft lip nose].

OBJECTIVE: The aim of this work was to correct the secondary deformities of unilateral cleft lip nose. METHODS: On the basis of patho-anatomical study and the comprehension on the cleft lip nose, a new approach to correct the secondary deformities of unilateral cleft lip nose was designed and used. During operation, an intranasal and marginal combining incision was made to explore the alar cartilages and to from a mucosal-cartilage flap in the nasal vestibule. After the deformity of septal cartilage and the abnormalities of the alar base on the cleft side were repaired, the total alar cartilage was repositioned and rotated with suspension and V-Y advancement to correct the nasal deformities. RESULTS: Since 1993, a total of 92 cases were treated by the above procedure and satisfactory results were obtained. CONCLUSION: The clinical applications showed that there were several advantages for this method, and good results can be gained by repositioning the total alar cartilage on the cleft side.

Abnormalities, Multiple↗

PubMed1999

[Chemical constituents of Pistia stratiotes L].

OBJECTIVE: To investigate the chemical constituents of Pistia stratiotes, a kind of duckweed. METHOD: Compounds were separated by chromatography on sillica gel, and their structures were identified by spectral analysis and chemical evidence. RESULT: Four compounds were obtained and identified as stigmasta-4,22-dien-3-one, stigmasterol, stigmasteryl stearate and palmitic acid. CONCLUSION: All the four compounds were isolated from this plant for the first time.

Araceae↗

PubMed1999

[Isolation and identification of two flavonoids from Taraxacum mongolicum Hand.-Mazz].

OBJECTIVE: To study the chemical constituents of Taraxacum mongolicum. METHOD: Compounds were separated by column chromatography on silica gel and polyamide, and their structures were determined by spectral analysis and chemical evidence. RESULT: Two flavonoid compounds were separated and elucidated as isoquercitrin and hyperin. CONCLUSION: These two compounds were isolated from the plant for the first time.

Flavonoids↗

PubMed1999

[Relationship between complement activation and reactive oxygen species generation in inflammatory response].

OBJECTIVE: To verify the proposed activation feedback mechanism between complement and polymorphonuclear leukocytes(PMN) derived reactive oxygen species(ROS). METHODS: In vitro tests were designed to identify the activation feedback process by alternative activations of complement by inulin or PMNs by 12-O-tetradecanoylphorbol-13-acetate(TPA) in the test medium in consisting serum complement and isolated PMNs, with chemiluminescence technique to determine the production of ROS and complement fixation trial for complement activations. RESULTS: Evidently that activated complement could activate PMNs to release ROS which further activated complement, so the activating feedback cycle was set. CONCLUSIONS: The complement and PMNs-ROS activation feedback cycle mechanism was recognized. It was expected to serve for delineating the regulation of inflammatory response.

Animals↗

PubMed1999

[Effects of abalong polysaccharide on the activity of the peritoneal macrophages and delayed-type hypersensitivity in mice bearing S180].

The effect of Abalone polysaccharide(Ap) which extracted from Haliotis discus hannai Ino on phagocytosis activity of the peritoneal macrophages and delayed-type hypersensitivity in mice bearing S180 were studied. The results showd that the ablong polysaccharide promoted the phagocytosis activity of the peritoneal macrophages and delayed-type hypersensitivity in mice bearing S180. It was suggested that the polysaccharide inhibited tumor growth maybe by activating the macrophage and T cells.

Animals↗

PubMed1999

[Synergy and attenuation of cyclophosphamidum (CTX) activities by abalone polysaccharide].

Abalone polysaccharide (AP) was extracted from Haliotis discushannai Ino. The combined effects of AP and CTX against tumor-bearing mice were investigated. The results showed that AP could markedly promote the inhibition effects of CTX on S180 and HepA tumor, enhance protection against leukocytopenia, decrease of spleen and thymus weight and hemolysin in serum, and bone marrow supression induced by CTX.

Animals↗

PubMed1998

Interaction of transcription factors with serum response factor. Identification of the Elk-1 binding surface.

Serum response elements (SREs) play important roles in transforming extracellular signals into specific nuclear responses. The SRE-binding protein, serum response factor (SRF), plays a pivotal role in this process. Several transcription factors have been shown to interact with SRF and thereby create distinct complexes with different regulatory potentials. The ETS domain transcription factor Elk-1 is one such protein and serves to integrate distinct mitogen-activated protein kinase cascades at SREs. Elk-1 uses a short hydrophobic surface presented on the surface of an alpha-helix to interact with SRF. In this study we have used site-directed mutagenesis to identify residues in SRF that comprise the Elk-1 binding surface. The Elk-1 binding surface is composed of residues that lie on a hydrophobic surface-exposed groove located at the junction of the MADS box and C-terminal SAM motif. Different residues are implicated in interactions between SRF and the transcription factor Fli-1, indicating that although some overlap with the Elk-1 binding surface occurs, their interaction surfaces on SRF are distinct. Our data are consistent with the hypothesis that the SRF DNA-binding domain acts as docking site for multiple transcription factors that can bind to small surface-exposed patches within this domain.

Amino Acid Sequence↗