Biomedical subjects

R Gao

Publications and source records attributed to R Gao.

At least 91 records · Page 5Linked to original sources

PubMed1996

Left ventricular diastolic dysfunction in patients with angina decubitus.

OBJECTIVE: To investigate the relationship between left ventricular diastolic dysfunction and episodes of angina decubitus. METHODS: The study population consisted of three groups, groups I (20 controls) had no cardiovascular diseases. Group II (20 patients) had coronary artery disease (CAD) without angina decubitus. Group III (24 cases with ejection fraction (EF) > 45%) were selected from 26 patients with angina decubitus. RESULTS: Left ventriculography (LVG) showed that left ventricular (LV) first 1/3 filling fraction (1/3FF) was significantly reduced in groups III as compared with groups II and I (P < 0.01). Left ventricular end-diastolic pressure (LVEDP) significantly increased in patients with angina decubitus after LVG as compared with that before LVG (P < 0.01). However, there were no statistically differences in LVEDP, before and after LVG in both groups II and I. CONCLUSIONS: Patients with angina decubitus have abnormalities of LV diastolic filling and decrease in LV compliance.

Adult↗

PubMed1996

Macrophages in human epiretinal and vitreal membranes in patients with proliferative intraocular disorders.

PURPOSE: Macrophages are versatile cells and have been known as a cellular component of epiretinal membranes of proliferative intraocular disorders (PID). However, the origin and functions of these cells in the membranes are not yet clear. In the present study we investigated the characterization of macrophages/monocytes in various types of human epiretinal membranes from patients with proliferative vitreortinopathy (PVR), proliferative diabetic retinopathy (PDR) and ocular perforating injury by means of immunohistochemical techniques. METHODS: A total of 49 epiretinal membranes of PID in which 24 were PDR specimens, 17 were PVR and 8 were proliferations after perforating eye injury were studied. Monoclonal antibodies against human macrophages, monocytes, HLA-DR antigen and interleukin-1 (IL-1) were used. The alkaline phosphatase anti-alkaline phosphatase (APAAP) technique was performed. RESULTS: The results showed that 19 out of 24 PDR specimens (79%), 15 out of 17 PVR specimens (88%) and 7 out of 8 traumatic specimens (87%) contained macrophages, HLA-DR antigen was detected in 20 out of the 24 PDR membranes (83%), 14 out of 17 PVR membranes (82%) and 5 out of 8 traumatic membranes (63%); monocytes were only detected in 10 out of the 24 PDR specimens (41%). In addition, in a group of PDR specimens, interleukin-1 (IL-1) was detected in 8 out of 13 tested specimens (62%). CONCLUSION: The results revealed that the macrophages in the membranes were in an active stage and may play a significant role in the development of proliferative intraocular disorders through either inducing inflammatory reactions or immune responses, or the effects of their cytokines.

Diabetic Retinopathy↗

PubMed1996

[The study on changes of macular light sensitivity before and after photocoagulation for diabetic macular edema].

OBJECTIVE: The study was designed to determine whether laser photocoagulation could damage macular visual function in treatment of diabetic macular edema. METHODS: A prospective clinical trial was taken to determine the effects of argon green (514.5nm) laser photocoagulation on macular light sensitivity (MLS) by comparing the self MLS pairing data collected from a Humphrey automatic visual field analyzer before and after the procedure. Nineteen eyes of 15 patients with diabetic macular edema consistent with its diagnostic criteria were enrolled in this study, a follow-up period being 3 months. RESULTS: The mean MLS at the photocoagulation area, non-photocoagulation area, 5 degrees and 13 degrees eccentricity were significantly decreased within 1 week after the treatment, the drops of MLS were 1.85 dB, 1.05 dB, 0.99 dB, 1.66 dB respectively (P < 0.05). The mean reduction of MLS at the fovea within 1 week after the treatment has no statistical significance. The MLS gradually recovered at the 1st and 3rd month after photocoagulation, and the visual acuities in most of the cases were stable or increased. CONCLUSIONS: MLS is affected little by laser photocoagulation, and photocoagulation can reduce the risk of visual loss or increase visual acuity in an eye with diabetic macular edema.

Adult↗

PubMed1996

[Vitreous surgery for subretinal neovascular membrane and hemorrhage].

OBJECTIVE: To study the indications, techniques and therapeutic effects of vitreous surgery for subretinal neovascular membranes. METHODS: 6 cases of subretinal neovascularization and subretinal hemorrhage were treated by vitreoretinal surgery. The surgical techniques consisted of three port pars plana vitrectomy, intraocular laser, retinotomy, subretinal neovascular membrane resection or hemorrhage removal, air-fluid exchange, etc. The pre and post-operative examinations included fundus fluorescein angiography (FFA), Humphry visual field to evaluate the therapeutic effects of the surgery. RESULTS: The postoperative follow-up ranged from 4 to 7 months. The visual acuities of 4 cases improved, 0.3 or over in 2 cases and unchanged in 2 cases. CONCLUSION: Subretinal operation may be a safe and effective method to treat subretinal neovascularization if the indication was well mastered.

Adult↗

PubMed1996

[Long-term prognosis of percutaneous transluminal coronary angioplasty in 229 cases].

In order to approach long-term efficacy of percutaneous transluminal coronary angioplasty (PTCA) and the factors affecting its efficacy in Chinese patients, 229 patients who underwent successful PTCA in this institution were followed by direct interview or letters. The rate of follow-up was 95% for the patients who should be followed. The period of follow-up was 0.5-8.4 (mean 2.3 +/- 1.8) years. Angina pectoris recurred in 76 (33.2%) of the patients. In 76% of the patients with recurrence, angina developed within 6 months after PTCA. Cox regression analysis revealed that the relative risk of recurrence of angina pectoris was increased among the patients with triple vessel disease and hypertension. During the period of follow-up, 2 (0.9%) patients died, 6 (2.6%) had non-fatal acute myocardial infarction, 4 (1.7%) had coronary artery bypass graft surgery, and 29 (12.7%) had repeat PTCA. The cardiac event free survival rate calculated by Kaplan-Meier method was 84.8% at 1 year and 70.5% at 8 years. Cox regression analysis revealed that there were positive correlations between stenosis of lesions before PTCA and residual stenosis of LAD after PTCA and the relative risks of cardiac events. In conclusion, the long-term efficacy of PTCA in Chinese patients was good. We suggest that to decrease the residual stenosis of LAD during procedure could probably decrease the relative risk of cardiac events during follow-up.

Adult↗

PubMed1996

[The relation between coronary vasospasm and coronary obstructive lesions in patients with variant angina].

A series of 38 patients with variant angina in whom coronary arteriography was performed was reviewed to investigate the relation between coronary vasospasm and coronary obstructive lesions. 10 of the 38 (26.3%) patients had completely normal coronary arteriograms; 4 (10.5%) had insignificant coronary artery disease (< 50% stenosis); 24 (63.2%) had significant (> or = 50% stenosis) coronary artery disease, including single vessel disease in 12 cases, multiple vessel disease in 11 cases and left main trunk disease in one case. The results of this study showed that the incidence of coronary vasospasm increased with the severity of coronary stenosis and was highest at 75%-90% stenosis of the ischemia-related artery in those patients with significant coronary disease. In this study of 38 patients, coronary vasospasm involved the left anterior descending artery (LAD) in 25 patients (65.8%), right coronary artery (RCA) in 10 (26.3%) and left circumflex artery (LCX) in 2 (5.3%), but in patients with in significant stenosis (< 50%), LAD was involved in 50.0%, RCA in 42.9% and LCX in 7.1%. These results indicate that coronary vasospasm occurs frequently in patients with severe stenosis of the LAD.

Adult↗

PubMed1996

[Study of pathogenesis of age-related macular degeneration].

OBJECTIVES: To explore the pathogenesis of age-related macular degenerastion (AMD) for its early prevention and treatment. METHODS: The enzymes of red blood cells, levels of serum mineral elements and antiretinal antibodies were determined in AMD and controls. Electronic microscopy, immunohistochemical survey of the AMD patient subretinal neovascular membrane were performed. The light exposure of animal experiment was also made. RESULTS: The levels of superoxide dismutase and catalase as well as serum zinc were decreased in AMD patients, the ratio of copper and zinc was increase. The retinal antibody reaction was higher than that of controls, and the subretinal neovascular membrane showed inflammatory granulomatous appearance. CONCLUSIONS: In addition to age, AMD may be related to light damage, change in human defense system and chronic inflammatory process.

Age Factors↗

PubMed1995

Impact of family history of colon cancer on development of multiple primaries after diagnosis of colon cancer.

PURPOSE: The purpose of this study was to assess risk of developing multiple primaries after a diagnosis of colon cancer and to determine the impact that having a family history of cancer has on cancer risk. METHODS: Data from the Utah Cancer Registry and the Utah Population Database were used. A cohort of 2,236 first primary colon cancers were observed for the subsequent development of additional primary cancers. RESULTS: We observed a greater than expected incidence of colon, rectal, and pancreatic cancers among the cohort. The standardized incidence ratios were 2.77 (95 percent confidence interval (CI), 2.07-3.70), 2.26 (95 percent CI, 1.34-3.81), and 2.38 (95 percent CI, 1.32-4.30), respectively. Having a family history of colon or rectal cancer did not greatly influence risk of having a multiple primary. However, there was a trend toward increased risk of pancreatic cancer (hazard rate ratios, 1.99; 95 percent CI, 0.67-5.90) and bladder cancer (hazard rate ratios, 2.35; 95 percent CI, 0.77-7.18) among patients with a family history of rectal cancer. We also observed that risk of uterine cancer in the cohort was positively associated with family history of uterine cancer, risk of breast cancer was positively associated with family history of breast cancer, and risk of prostate cancer was positively associated with family history of prostate cancer. CONCLUSIONS: People with colon cancer are at a greater risk of developing colon, rectal, and possibly pancreatic cancer. Although a family history of colon or rectal cancer did not have a large impact on developing other cancers, a family history of other primary cancers did influence risk of other cancers.

Aged↗

PubMed1995

Isolation and properties of a blood coagulation factor X activator from the venom of king cobra (Ophiophagus hannah).

A specific blood coagulation factor X activator was purified from the venom of Ophiophagus hannah by gel filtration and two steps of FPLC Mono-Q column ion-exchange chromatography. It showed a single protein band both in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and alkaline polyacrylamide gel electrophoresis. The mol. wt was estimated to be 62,000 in non-reducing conditions and 64,500 in reducing conditions by SDS-PAGE. The isoelectric point was found to be pH 5.6. The enzyme had weak amidolytic activities toward CBS 65-25, but it showed no activities on S-2266, S-2302, thrombin substrate S-2238, plasmin substrate S-2251 or factor Xa substrate S-2222. It had no arginine esterase activity toward substrate benzoylarginine ethylester (BAEE). The enzyme activated factor X in vitro and the effect was absolutely Ca2+ dependent, with a Hill coefficient of 6.83. It could not activate prothrombin nor had any effect on fibrinogen and thus appeared to act specifically on factor X. The procoagulant activity of the enzyme was almost completely inhibited by serine protease inhibitors like PMSF, TPCK and soybean trypsin inhibitor; partially inhibited by L-cysteine. Metal chelator EDTA did not inhibit its procoagulant activity. These results suggest that the factor X activator from O. hannah venom is a serine protease.

Animals↗

PubMed1995

Beneficial effects of NTG on left ventricular volumes and systolic function in patients with myocardial infarction.

The effect of sublingual administration and intravenous drip of nitroglycerin (SLNTG and IVNTG) on left ventricular volumes (LVVs) were studied and systolic function was quantitatively assessed with two-dimensional echocardiography (2DE) in 28 patients with myocardial infarction (MI), including 13 cases without heart failure (MI-NHF) in one group and 15 with heart failure (MI-HF) in another. The results showed that after SLNTG and IVNTG in both groups the heart rate (HR) increased significantly (P < 0.05-0.001); the systolic blood pressure (SBP) decreased significantly (P < 0.05-0.001); the diastolic blood pressure (DBP) was not significantly changed (all P > 0.05); the left ventricular end-diastolic and end-systolic volumes (EDV and ESV) both significantly reduced [EDV: decreased by 5.8-11.6% (-13.2-19.0 ml), P < 0.05-0.001; ESV: decreased by 9.6-16.6% (-8.6-17.3 ml), P < 0.05-0.001)]; the left ventricular ejection fraction (LVEF) all significantly elevated (increased by 6.6%-9.4% (3.2%-3.4%), P < 0.05-0.001] except in MI-NHF group after IVNTG; the segmental EF of normal and hypokinetic segments also significantly increased (P < 0.05-0.001). The results suggest that NTG could beneficially reduce left ventricular EDV and ESV; and improve or strengthen its global and segmental systolic function in MI patients, particularly noticeable in patients with heart failure.

Blood Pressure↗

PubMed1995

Modified vitreous surgery for subretinal neovascularization and hemorrhage.

PURPOSE: To modify vitreous surgery for subretinal neovascularization (SRNV) and to determine the effects of this operation. METHODS: Six patients with SRNV were performed with this operation. The methods of examination before and after operation included: testing the best-corrected visual acuity before operation and 1, 3 or 6 months after operation; 30 degrees and macular 10 degrees Humphrey visual field examination; FFA examination preoperatively and 1, 3 or 6 months postoperatively. Modified surgery procedure is: a preventive buckling; pars plana vitrectomy; peeling the vitreous cortical; no intraocular diathermy; small retinotomy; subretinal surgery; air-fluid exchange. RESULTS: SRNV was taken off in 4 cases. Subretinal hemorrhage was washed in 2 cases. After 4 to 7 months follow-up, the visual acuity was improved in 4 cases, unchanged in 2 cases. The visual field was improved in 4 cases, unchanged in 1 case, decraesed in 1 case. The complications included macular hole due to surgery in 1 case and subretinal hemorrage in 1 case. CONCLUSION: The surgery criteria were: 1) massive subretinal hemorrhage; 2) some patients of SRNV included: FFA evidence they showed the membrane is beneath fovea, the best V. A is 20/100 or lower, and can't be treated by laser and the patient consent. This modified subretinal operation is safe, and effective for massive hemorrhage and some SRNVS.

Adult↗

PubMed1995

[Effects of low dose aspirin on platelet function and prostaglandins metabolism in systemic and coronary circulation in patients with ischemia heart disease].

Eleven patients with ischemia heart disease (IHD) were treated with low dose aspirin (ASA, 50mg/day) for more than two weeks (ASA group). 29 cases with IHD not taking ASA served as patient control (NASA group) and 13 cases without IHD not taking ASA as normal control. Blood samples for measurement of plasma (serum) TXB2 and 6-keto-PGF1 alpha were simultaneously taken from aortic root (AO) and coronary sinus (CS). The results showed: ASA group had lower plasma TXB2 level in AO blood than NASA group (P < 0.05), but there was no significant difference in plasma 6-keto-PGF1 alpha level between the two groups. Both of plasma and serum TXB2/6-keto-PGF1 alpha ratios in AO blood in ASA group were significantly lower than those in NASA group (P < 0.05 and P < 0.0005 respectively). Plasma TXB2 CS/AO ratio and 6-keto-PGF1 alpha CS/AO ratio in ASA group were significantly lower than those in NASA group (P < 0.05), but not different from those in control group. Both ASA and NASA groups had lower serum TXB2 CS/AO ratios than control group (P < 0.05). The results suggest that low dose aspirin inhibits selectively TXA2 synthesis in systemic circulation and inhibits synthesis and/or release of TXA2 and PGI2 equally (no selectivity) in coronary circulation, but could not completely inhibit intracoronary platelet activation.

6-Ketoprostaglandin F1 alpha↗

PubMed1995

[Left ventricular diastolic dysfunction in patients with angina decubitus].

Our study population consisted of three groups: 1. 24 cases with ejection fraction (EF) > 45% in 26 patients with angina decubitus (AD) were studied as group A. 2. 20 patients had coronary artery disease without AD as group B. Group B and A were matched for age, EF and coronary artery obstructive lesions. 3. 20 cases without cardiovascular diseases as group C. Left ventriculography (LVG) was performed in these patients. The results showed that left ventricular (LV) early 1/3 filling fraction (1/3FF) was significantly reduced in group A as compared with that in group B and C (both P < 0.001). The findings suggest that patients with AD have abnormalities of LV diastolic filling. Left ventricular end diastolic pressure (LVEDP) significantly increased in patients with AD after LVG as compared with before LVG (P < 0.01). However, there was no statistically difference in LVEDP before and after LVG in both group B and C, indicating that the compliance of LV was also decreased in patients with AD. The increase of LV volume after recumbency would cause increase of LV wall tension and myocardial contraction and aggravate the LV diastolic dysfunction, resulting in a progressive increase in myocardial oxygen consumption. Therefore, we consider that on the basis of severe coronary artery obstructive lesions, LV diastolic dysfunction is a significant pathologic factor in the pathogenesis of AD.

Adult↗

PubMed1995

[Vitrectomy for treatment of vitreous hemorrhage associated with age-related macular degeneration].

Age-related macular degeneration (AMD) is an aging disorder which has been a leading cause for blindness among old people. The wet type AMD is the main cause which deteriorates visual function rapidly because of the complications including detachment of retinal pigment epithelium, formation of subretinal neovascular membrane and scar, subretinal and vitreous hemorrhage. This assay reports the results of vitrectomy for treatment of 10 cases with vitreous hemorrhage associated with AMD. The follow-up periods ranged from 1/2 to 28 months. The visual acuities in 9 cases were increased and in 1 case decreased. The factors affecting the postoperative visual acuity, operative complications and therapeutic prospects of the surgery were discussed.

Age Factors↗

PubMed1995

[Cataract after silicone oil tamponade and its surgical treatment].

Twelve eyes of twelve cases of cataract after complicated retinal detachment surgery and silicone oil tamponade were treated in this report. Successful extracapsular cataract extraction (ECCE) was performed on 10 of the 12 cases, no oil escape occurred in any of the operation and in one eye an intraocular lens was implanted. Intraoperatively, loss of large amount of silicone oil occurred and it was removed completely in ECCE in 2 cases. After the follow-up periods of 3 approximately 30 months (mean, ten months), ten cases with the intact posterior capsule and silicone oil in place had a good view of the fundus, their retinae were attached and visual acuities were recovered above the best levels after retinal detachment surgery. Two cases with silicone oil removal suffered from retinal re-detachment. The main points of the surgery were discussed, and the effective method of prevention from silicone oil escape and maintenance of the transparency of the posterior capsule after ECCE were proposed.

Adolescent↗

PubMed1994

Evaluating for vitreous surgery used in proliferative vitreoretinopathy grade D3.

Proliferative vitreoretinopathy (PVR) is one of the main failure causes of retinal detachment repair. In this paper, 25 cases of vitreous surgery used in the PVR D3 are analyzed. The diagnosis of PVR depended on the classification of the American Retina Society Terminology Committee. Vitrectomy and peeling were carried out in all of the patients. Intraocular tamponade included silicone oil and gas tamponade. Follow-up is more than 3 months. The anatomic successful rate was 68% and 11 cases arrived 20/400 or better. The complications included vitreous hemorrhage, cataract, silicone oil into anterior chamber, PVR recurrent and so on. The authors suggest that vitrectomy combined with peeling and intraocular tamponade be key for the treatment of PVR D3. Silicone oil tamponade may improve the patients' prognosis. PVR formation is connected with the operative irritation, giant tear, trauma and vitreous hemorrhage. Adaptation and time of the vitreous surgery are discussed in this paper, too.

Adolescent↗

PubMed1994

[Argon laser photocoagulation in the treatment of central serous chorioretinopathy].

Thirty-six cases (41 eyes) with central serous chorioretinopathy were treated by using argon laser photocoagulation. The results showed that the number of eyes with vision equal to or more than 1.0 increased from 7 (17.1%) pre-laser to 26 (63.4%) post-laser, while the number of eyes with vision less than 1.0 decreased from 25 (61%) pre-laser to 6 (14.6%) post-laser. The subretinal fluid was almost entirely absorbed from 1 week to 1 month after, and central fovea reflex could be seen in some cases. The results indicate that the vision prognosis is strongly related to the duration of the disease, but the direction of leakage to the fovea, the distance between the leakage and the fovea, and the dimension of sensory retina detachment are factors which weakly affect the post-laser vision.

Adult↗

PubMed1993

[Laser treatment for the membranous cataract: the significance of pre-laser interferometric acuity].

Laser interferometer was used for the detection of interferometric acuity before and after membranous cataract disruption by Q--switched Nd: YAG laser in 23 patients (23 eyes). There was no significant difference between the interferometric acuity before and after laser surgery (p < 0.05). The postoperative corrected acuity was related positively to the preoperative one (p < 0.05). 65.2% of the eyes had a postoperative corrected acuity better than the postoperative interferometric acuity. These results show that laser interferometric acuity is a valuable method in the evaluation of postoperative visual acuity, but false negative and false positive ones should be considered under some circumstances. The interferometric acuity can be affected by aphakia (high refractive error).

Aged↗