Biomedical subjects

J Ge

Publications and source records attributed to J Ge.

At least 37 records · Page 2Linked to original sources

PubMed2001

Optical coherence tomography in measuring retinal nerve fiber layer thickness in normal subjects and patients with open-angle glaucoma.

OBJECTIVES: To investigate image characteristics and thickness of the retinal nerve fiber layer (RNFL) in normal and glaucomatous eyes using optical coherence tomography (OCT), and analyze the relationship between RNFL thickness and visual field index. METHODS: Eighty-three normal persons (150 eyes) and 83 patients with primary open angle glaucoma (POAG, 149 eyes) underwent OCT examinations with 3.4 mm diameter circle scan to calculate the RNFL thickness. Statistical analysis was used to compare differences in RNFL thickness in quadrants and means between the normal and glaucomatous groups and the different stages of POAG. Linear correlation and regression analysis were used to show the correlation between RNFL thickness and visual field index of 115 eyes in glaucomatous patients. Reproducibility, sensitivity and specificity of RNFL measurements using OCT were evaluated. RESULTS: RNFL thickness measured by OCT in normal subjects was thicker in superior and inferior, less in temporal, and thinnest in nasal quadrants. The curve showed double peaks. RNFL of glaucomatous patients showed local thinning or defect, diffuse thinning, or both. The mean RNFL thicknesses of the normal group in the temporal, superior, nasal and infelor quadrants were 90.1 +/- 10.8 microns, 140.4 +/- 10.5 microns, 85.2 +/- 14.0 microns, and 140.4 +/- 9.7 microns, respectively with a mean of 114.2 +/- 6.0 microns. The numbers for the glaucomatous group were respectively 56.0 +/- 31.0 microns, 81.0 +/- 36.3 microns, 47.1 +/- 27.5 microns, and 73.4 +/- 38.4 microns for the four quadrants, with a mean of 64.6 +/- 28.8 microns. There was a significant difference in RNFL thickness between the normal and glaucomatous groups (P < 0.000), and the three stages (early, developing and late) of glaucomatous groups (P < 0.000). There was a close negative relationship between RNFL thickness and visual field index (r = -0.796, P < 0.0001). The sensitivity and specificity of RNFL thickness in POAG measured using OCT were 93.3% and 92.0%, respectively. CONCLUSIONS: OCT can quantitatively measure RNFL thickness differences between normal persons and glaucomatous patients. RNFL thickness gradually decreases while visual field defect increases with the development of POAG.

Adolescent↗

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

[A study on susceptibility of different layers of rabbit retina to ocular hypertension].

OBJECTIVE: To investigate the histological damage and its degrees of different layers of rabbit retina induced by ocular hypertension. METHODS: The intraocular pressure (IOP) was elevated by intracameral injection of 0.10 - 0.15 ml of 2% methylcellulose in sixteen gray rabbits. The rabbit eyes were enucleated, fixed, and paraffin-embedded. For histological evaluation, the slides were stained with hematoxylin-eosin, examined by light microscopic and computer automatic image analysis. RESULTS: The quantitative analysis indicated that all of the retinal layers have different degrees of histopathological damage. Among them, the retinal ganglion cells (RGCs) and retinal nerve fiber layer (RNFL) were most severely damaged, with the decrease rate of 74.3% and 61.9%, respectively. The decrease rates of other retinal layers were as follows: the retinal inner layer, 42.4%; the whole sensory layer of the retina, 35.0% and the outer layer, 24.2%. We also found a significant correlation between RGCs loss and RNFL thinning (r = 0.68, P < 0.01), demonstrating a strong correlation between IOP level and RNFL thickness (F = 8.97, P < 0.01). CONCLUSION: All of the anatomic layers of retina can suffer from degeneration and atrophy at different degrees.

Animals↗

PubMed2001

[Amplifying variable region gene of light chain of monoclonal antibody against human retinoblastoma by PCR].

OBJECTIVE: To acquire the variable region gene of light chain of monoclonal antibody against human retinoblastoma. METHODS: Total RNA were extracted from hybridoma cells secreting specific monoclonal antibody(McAb) against human retinoblastoma(RB), then transcripted reversely into cDNA with random primers. The variable region of the light chain(VL) gene fragments were ampliflied using polymerase chain reaction(PCR) method. Agrose gel electrophoresis was confirmed. RESULTS: 1.5% agrose gel electrophoresis indicated that VL gene was about 340 base pairs. CONCLUSION: The light chain variable region gene of the McAb against human RB was amplified successfully, which lays a good basis for construction of a recombinant antibody.

Antibodies, Monoclonal↗

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

Phacoemulsification in patients with secondary glaucoma caused by uveitis.

PURPOSES: To evaluate the effect of phacoemulsification in the patients with uveitis, secondary glaucoma and complicated cataract. METHODS: Phacoemulsification and implantation of a foldable intraoucular len was performed in 12 patients(13 eyes) with uveitis, secondary glaucoma and complicated cataract. The complications, intraocular pressures (IOP), and visual acuity were observed postoperatively. RESULTS: No severe complication was found in the patients postoperatively or within the operation procedure. The visual acuity was improved after the operation (P < 0.05). The intraocular pressures and/or the number of antiglaucoma medications reduced in 3 months of the follow-up time. CONCLUSION: Phacoemulsification is the best way to treat the patients with secondary glaucoma and complicated cataract caused by uveitis.

Adult↗

PubMed2001

Identified circadian rhythm genes of ciliary epithelium with differential display.

PURPOSE: To identify differential genes expressed in the rabbit ciliary epithelium during the circadian cycle of aqueous flow. METHODS: Total RNA from ciliary epithelium of rabbits at 8 AM (light on 1 hour) and 8 PM (light off 1 hour) were compared by differential display reverse transcription-polymerase chain reaction (DD RT-PCR), using 6% denaturing polyacrylamide electrophoresis, choose differential display bands, cut and reamplify with the same primer, clone and sequence. Search the database of Genbank, prolong them with 5' RACE and 3' RACE technique then clone, sequence and search database of Genbank. RESULTS: 93 Significant differences gene expression were detected between light on and light off in the rabbit ciliary epithelium. CONCLUSION: Differential display is a powerful tool to screen differentially expressed genes in circadian rhythm of ciliary epithelium.

Animals↗

PubMed2001

The preliminary experimental study of induced differentiation of embryonic stem cells into corneal epithelial cells.

PURPOSE: To study preliminarily induced differentiation of embryonic stem cells into corneal epithelial cells in vitro. METHODS: Murine embryonic stem cells were co-cultured with Rabbit limbal corneal epithelial cells in Transwell system to induce differentiation. Mophological and immunohistochemical examination were implemented. RESULTS: The induced cells from embryonic stem cells have an epithelial appearance. The cells formed a network and were confluent into film gradually after being co-cultured with rabbit limbal corneal epithelial cells for 24-96 hours. The cells ranged mosaic structure and localized together with clear rim. Most of the cells showed polygonal appearance. Transmission electron microscope showed lots of microvilli on the surface of induced cells and tight junctions between them. These epithelial-like cells expressed the corneal epithelial cell specific marker cytokeratin3/cytokeratin12. CONCLUSION: The potential mechanism of the differentiation of murine embryonic stem cells into corneal epithelial cells induced by limbal corneal epithelial cell-derived inducing activity is to be further verified.

Animals↗

PubMed2001

Construction of the enhanced yellow fluorescent protein expression vector carrying IFN-gamma gene.

PURPOSE: To construct the enhanced yellow fluorescent protein (EYFP) vector carrying interferon-gamma gene (ifn-gamma) in order to provide an ideal reporter in the expression of ifn-gamma and location of protein in vitro and in vivo. METHOD: According to the nucleotide sequence of ifn-gamma gene, a pair of oligonucleotides was designed as primer whose two end contained nucleotide sequence of EcoR V and Not I restriction endonuclease respectively. The gene encoding for inf-gamma was amplified using PCR technqiue. After the PCR product was retrieved and purified, it was digested with EcoR V and Not I restriction endonuclease, and then cloned into the plasmid pIRES-EYFP. The recombinant plasmid pIRES-EYFPIFN-gamma was identified by restriction endonuclease enzyme analysis and DNA sequence analysis. RESULTS: The ifn-gamma was successfully amplified and verified by partial DNA sequence analysis. The recombinant plasmid was correctly screened. CONCLUSION: The EYFP expression vector carrying ifn-gamma gene was successfully established. This research work has formed a base for monitoring the ifn-gamma gene expression and protein position in living cells.

Bacterial Proteins↗

PubMed2001

[Phacoemulsification in patients with cataract and overfiltering bleb after antiglaucoma surgery].

PURPOSE: To evaluate the effect of phacoemulsification in patients with cataract, overfiltering bleb, and low-tension after antiglaucoma surgery. METHODS: Phacoemulsification and implantation of a foldable intraocular len was performed in six patients(7 eyes) with overfiltering bleb, low-tension, and cataract. The complications, blebs, intraocular pressures(IOP), and visual acuity were observed postoperatively. RESULTS: No severe complication was found. The overfiltering blebs constricted and their walls became thicker three months after the operation. The visual acuity and IOP were improved (P < 0.05). CONCLUSION: Phacoemulsification may be another way to treat the patients with cataract and overfiltering bleb, low-tension after antiglaucoma surgery.

Aged↗

PubMed2001

[Influence of cell cycle in human trabecular cells induced by dexamethsone].

PURPOSE: To investigate the influence of dexamethesone (Dex) on cell cycle in human trabecular cells(HTC). METHODS: The trabecular specimens from human eyes were cultured in vitro. Then the cultured cells were immersed in DMEM solution containing 10(-7) M dexamethesone for three, five and seven days. The cell cycle was detected by Flow Cycometry. RESULTS: The G2 phase of cell cycle in HTC increased when HTC were treated by Dex. The G2 phase was 2% in control group. For three, five and seven days treated by Dex, the G2 phase were 8%, 16.3 and 19.4%. CONCLUSION: The influence of cell cycle might be induced by Dex, it may be related with the pathogenesis of glucocorticoid induced glaucoma.

Cell Cycle↗

PubMed2000

Fabrication and Characterization of a New Self-Assembled Monolayer of Fullerene Dicarboxylic Acid Derivative and Its Photoelectric Conversion Property.

A new fullerene self-assembled monolayer (SAM) which has the property of photoelectric conversion is reported here. The SAM was fabricated on hydrophilic substrates by an esterification reaction. The SAM is characterized by contact angle, AFM, UV spectrum, and cyclic voltammetry. A cathodic photocurrent of 226 nA/cm(2) was obtained. Copyright 2000 Academic Press.

Journal Article↗

PubMed2000

Long-term effect of Nd:YAG laser posterior capsulotomy on intraocular pressure.

OBJECTIVE: To study the long-term effect of Nd:YAG capsulotomy on intraocular pressure (IOP). METHODS: We reviewed the records of patients with bilateral pseudophakia who received Nd:YAG capsulotomy in only 1 eye. Using the Wilcoxon rank sum test, we compared the mean change in IOP in eyes before and after capsulotomy with that of the noncapsulotomy eyes at corresponding time intervals. Using multiple regression tests, we analyzed the factors significantly associated with postcapsulotomy long-term IOP increases. RESULTS: The study included 100 patients who were followed up for a median of 1.5 years after capsulotomy. The mean +/- SD age of the study group was 76+/-7 years, and 37 patients had glaucoma. The changes in IOP in the eyes treated with capsulotomy were significantly higher than those in noncapsulotomy eyes at each time interval following capsulotomy. The long-term IOP increase was significantly associated with the IOP increase measured 1 hour after the capsulotomy (P =. 001). Patients with glaucoma were more likely to require long-term additional glaucoma medication than were nonglaucoma patients to require initial glaucoma therapy after the capsulotomy (P =.002). CONCLUSION: After Nd:YAG capsulotomy, long-term IOP is often elevated above precapsulotomy baselines, especially in glaucoma patients or patients who experience a significant IOP increase within hours after the capsulotomy.

Aged↗

PubMed2000

Corrected coronary flow velocity reserve: a new concept for assessing coronary perfusion.

OBJECTIVES: In order to limit the variability of coronary flow velocity reserve (CFVR), we analyzed which factors independently affect CFVR and established a new parameter integrating these factors. BACKGROUND: Coronary flow velocity reserve (CFVR) is a frequently used parameter for evaluating the physiological significance of epicardial stenosis and microvascular function. Since CFVR measurements are done in substantially different hemodynamic and clinical situations, interpretation of CFVR requires correction for major influencing factors. METHODS: In 141 patients with angina-like symptoms and angiographically unobstructed coronary arteries, intracoronary Doppler measurements were performed in at least two coronary vessels. Coronary flow velocity reserve was calculated as the ratio of hyperemic average peak velocity (hAPV), after intracoronary bolus of adenosine, to baseline average peak velocity (bAPV). RESULTS: Analysis of covariance revealed that only bAPV (p < 0.0001) and age (p < 0.0001) were independent factors influencing CFVR. Based on a regression model for estimation of predicted CFVR values, individual CFVR values (CFVRind) obtained at different bAPV and age were transformed in corrected CFVR values (CFVRcorr) by relating them to a mean bAPV of 15 cm/s and a mean age of 55 years. The transformation from CFVRind into CFVRcorr for the left anterior descending artery can be done by using the following equation: CFVRcorr = 2.85*CFVR(ind)*10(0.48*log(bAPV)+(0.0025*age)-1.16). When applying this new parameter to conditions assumed to cause microvascular dysfunction, analysis showed that only patients with diabetes showed a significant decrease of traditional CFVR and CFVRcorr, whereas a history of hypertension and current smoking habit had no influence on CFVRcorr. CONCLUSIONS: The concept of CFVRcorr standardizes CFVR for bAPV and age as the major physiological determinants. Especially in patients with microvascular dysfunction, this approach may help to discriminate between conditions directly affecting vasodilator reserve and conditions primarily affecting bAPV.

Blood Flow Velocity↗

PubMed2000

The nitroreductase/CB1954 combination in Epstein-Barr virus-positive B-cell lines: induction of bystander killing in vitro and in vivo.

Epstein-Barr virus (EBV)-based gene delivery vectors that preferentially express toxic genes in EBV-infected cells could be used to target EBV-positive tumors for destruction. We have shown previously that the cytosine deaminase (CD) enzyme, which converts the prodrug 5-fluorocytosine (5-FC) into the toxic compound 5-fluorouracil efficiently kills EBV-positive cells in the presence of 5-FC, with a substantial bystander killing effect in vitro and in vivo. To identify the optimal enzyme/prodrug combination for treating EBV-positive lymphomas, we have compared the effectiveness of the CD/5-FC combination with the nitroreductase (NTR)/CB1954 combination for killing EBV-positive B-cell lines. NTR metabolizes CB1954 into an alkylating agent that cross-links DNA. When the CD gene or the NTR gene were transfected into two different EBV-positive B-cell lines in vitro, approximately 90% of cells were killed in a prodrug-dependent manner, although the transfection efficiency was <5%. However, severe combined immunodeficient mouse tumors containing either 30% or 100% of NTR-expressing Burkitt lymphoma (Jijoye) cells were growth inhibited, but not cured, by treatment with intraperitoneal CB1954 (20 mg/kg/day) for 10 days. These results suggest that the NTR/CB1954 combination induces efficient bystander killing of EBV-positive B-cell lines in vitro but may not be as effective as the CD/5-FC combination for treating B-cell lymphomas in vivo.

Animals↗

PubMed2000

Safety of intracoronary Doppler flow measurement.

BACKGROUND: With the introduction of Doppler-tipped guide wires, intracoronary Doppler flow measurement has been increasingly accepted as an additional diagnostic approach in the catheterization laboratory. However, the safety of intracoronary Doppler flow measurement has not been well-investigated. The purpose of our study was to evaluate the safety of intracoronary Doppler flow measurement using the Doppler FloWire (Cardiometrics, Mountain View, Calif). METHODS AND RESULTS: A total of 906 patients were examined by intracoronary Doppler with a 0.014-inch or an 0.018-inch Doppler FloWire. For coronary flow reserve measurement, intracoronary injection of adenosine or papaverine was used. Of the patients studied, 77 were cardiac transplant recipients and 829 were patients who had not received a transplant, of whom 617 had undergone diagnostic coronary procedures and 212 had coronary interventions. In 27 (2.98%) of 906 patients adverse cardiac events were observed. Fifteen (1.66%) of 906 patients had severe transient bradycardia develop (asystole or second- to third-degree atrioventricular block) after intracoronary administration of adenosine, 14 of which occurred in the right coronary artery and 1 in the left anterior descending artery. Nine (0.99%) of 906 patients had coronary spasm during the passage of the Doppler wire (5 in the right coronary artery, 4 in the left anterior descending artery). Two (0.22%) of 906 patients had ventricular fibrillation during the procedure. Hypotension with bradycardia and ventricular extrasystole each occurred in 1 (0.11%) of 906 patients. The incidence of complication was significantly higher in transplant recipients than in patients who underwent either diagnostic or interventional procedures (12.99% vs 2.43% vs 0.94%, P <.001). The Doppler measurements in the right coronary artery were associated with a higher incidence of complications, especially bradycardia, compared with the left anterior descending and the left circumflex arteries (right coronary, 5.87% vs left anterior descending, 1.05% vs left circumflex, 0.17%; P <.001). All complications were cured medically. CONCLUSION: Intracoronary Doppler flow measurement with Doppler wires and intracoronary administration of adenosine is a safe method. However, severe complications such as bradycardia and coronary spasm can occur. Attention should be paid to the examination of the right coronary artery, especially in heart transplant recipients.

Adenosine↗

PubMed2000

Size of emptied plaque cavity following spontaneous rupture is related to coronary dimensions, not to the degree of lumen narrowing. A study with intravascular ultrasound in vivo.

OBJECTIVE: To identify any potential relations between the size of an emptied plaque cavity and the remodelling pattern, plaque or vessel dimensions, lumen narrowing, and other ultrasonic lesion characteristics. DESIGN: Intravascular ultrasound was used to examine prospectively 51 ruptured ulcerated coronary plaques. Cross sectional area measurements comprised lumen, vessel, plaque, and emptied plaque cavity. Lumen narrowing was calculated as 1 - (lesion lumen area/reference lumen area) x 100%. A remodelling index was calculated as lesion vessel area/reference vessel area, and plaques were divided into those with values > 1.05 (group A) and </= 1.05 (group B). RESULTS: Of the total of 51 plaques, 36 (71%) were assigned to group A and 15 (29%) to group B. In neither group was there a significant difference in reference dimensions and lumen narrowing. However, lesion vessel (mean (SD): 22.6 (8.1) mm(2) v 17. 5 (4.3) mm(2); p = 0.006) and plaque areas (15.8 (6.2) mm(2) v 12.8 (3.2) mm(2); p = 0.03) were greater in group A than in group B. The cavity inside the plaque was larger in group A than in group B (2.8 (1.6) mm(2) v 1.8 (0.9) mm(2); p = 0.007) and showed a positive linear relation with lesion and reference vessel size (r = 0.58 and 0.56, respectively; p < 0.001), but not with lumen narrowing. CONCLUSIONS: The size of the emptied cavity inside ruptured plaques is on average larger in lesions with adaptive vascular remodelling, and shows a linear relation with lesion plaque and vessel size and with the reference dimensions, but not with the degree of lumen narrowing.

Adult↗

PubMed2000

[A quantitative study of poincare dispersed-dot plot for heart rate variability].

Poincare dispersed-dot plot is an important nonlinear dynamics method that can effectively describe the attractor shape. Yet studies in the past generally processed the plot in a graphic mode without further discussion on the quantitative indices. That was not suited for clinical application and studies. So, based on the shape of Poincare dispersed-dot plot, we propose a group of quantitative parameters of Poincare dispersed-dot plot: plot square(SQ), long axis (LA), short axis(SA), and angle related to long-axis and short-axis(ALS). According to the characters of the heart rate Poincare dispersed-dot plot, we have posed the 'tortoise crawling and counting' algorithm to get these four quantitative parameters. We have tested these four quantitative parameters with clinical and animal experiment data. The results demonstrate that these four parameters are of certain specificity to heart diseases, indicating that these parameters might be useful for clinical diagnosis.

Algorithms↗