PubMed Health⌕ Search

Biomedical subjects

S Ge

Publications and source records attributed to S Ge.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Effect of CD11b/CD18 on burn-activated PMN-mediated permeability of pulmonary microvascular in isolated perfused lung].

OBJECTIVE: To determine the effect of intercellular adhesion molecule (ICAM-1) CD11b/CD18 in burn-activated PMN-mediated permeability of microvascular in isolated perfused lung. METHOD: Isolated lungs were distributed into 7 groups according to the different contents of perfused fluid: normal perfused fluid, normal rat serum, burn rat serum, normal rat PMN, burn rat PMN, normal rat PMN blocked by monoclonal antibody to adhesion molecule CD11b/CD18 and burn rat PMN blocked by antibody. The extent of isolated lung edema, vascular permeability to small molecules (fluid) and vascular permeability to large molecules (albumin) were expressed by lung weight gain (LWG), fluid filtration coefficient (Kf) and pulmonary albumin permeability-surface area product (PS) respectively. RESULT: Burn serum could increase LWG, Kf PS, so did burn-activated PMN. The latter could make PS increase more obviously. Monoclonal antibody to CD11b/CD18 on PMN could obviously decrease PMN sequestration in isolated perfused lung. The protective effect of antibody on increasing LWG and Kf, and particularly PS was demonstrated. CONCLUSION: (1) The effect of mediators from burn-activated PMN to EC was mediated by PMN adhesion to EC. (2) Some mediators from burn-activated PMN increase mainly the pulmonary vascular permeability to small molecules, and PMN adhesion to EC mediated by CD11b/CD18 may increase directly the permeability to large molecules. (3) Adhesion molecule CD11b/CD18 perhaps have an ability to regulate directly EC by combining its receptor ICAM-1 on EC.

Animals↗
PubMed1997

Feasibility, accuracy, and incremental value of intraoperative three-dimensional transesophageal echocardiography in valve surgery.

In this prospective trial, intraoperative 2-dimensional (2-D) and 3-dimensional (3-D) transesophageal echocardiography (TEE) examinations were performed on 60 consecutive patients undergoing cardiac valve surgery. Both 2-D (including color flow and Doppler data) and 3-D images were reviewed by blinded observers, and major valvular morphologic findings recorded. In vivo morphologic findings were noted by the surgeon and all explanted valves underwent detailed pathologic examination. To test reproducibility, 6 patients also underwent 3-D TEE 1 day before surgery. A total of 132 of 145 attempted acquisitions (91%) were completed with a mean acquisition time of 2.8 +/- 0.2 minutes. Acquisition time was significantly shorter in patients with regular rhythms. Reconstructions were completed in 121 of 132 scans (92%) and there was at least 1 good reconstruction in 56 of 60 patients (93%). Mean reconstruction time was 8.6 +/- 0.7 minutes. Mean effective 3-D time, which was the time taken to complete an acquisition and a clinically interpretable reconstruction, was 12.2 +/- 0.8 minutes. Intraoperative 3-D echocardiography was clinically feasible in 52 patients (87%). Three-D echocardiography detected most of the major valvular morphologic abnormalities, particularly leaflet perforations, fenestrations, and masses, confirmed on pathologic examination. Three-D echocardiography predicted all salient pathologic findings in 47 patients (84%) with good quality images. In addition, in 15 patients (25%), 3-D echocardiography provided new additional information not provided by 2-D echocardiography, and in 1 case, 3-D echocardiographic findings resulted in a surgeon's decision to perform valve repair rather than replacement. In several instances, 3-D echocardiography provided complementary morphologic information that explained the mechanism of abnormalities seen on 2-D and color flow imaging. In the reproducibility subset, preoperative and intraoperative 3-D imaging detected a similar number of findings when compared with pathology. Thus, in routine clinical intraoperative settings, 3-dimensional TEE is feasible, accurately predicts valve morphology, and provides additional and complementary valvular morphologic information compared with conventional 2-D TEE, and is probably reproducible.

Adolescent↗
PubMed1997

Morphology and dynamic change of discrete subaortic stenosis can be imaged and quantified with three-dimensional transesophageal echocardiography.

This report describes three-dimensional transesophageal echocardiographic findings in three consecutive patients with discrete subaortic stenosis. The discrete subaortic stenosis lesions included a circumferential, a remnant crescent, and a broken fibrotic subaortic membrane. The lesions were best imaged by using a three-dimensional transesophageal echocardiography-generated "aortotomy view" of the left ventricular outflow tract immediately below the plane of the aortic valve. The three-dimensional images correlated well with surgical and pathologic findings. The three-dimensional surface areas of the left ventricular outflow tract at the level of discrete subaortic stenosis during systole (0.8 +/- 0.5 cm2) and diastole (1.7 +/- 0.7 cm2) were measured by planimetry of the three-dimensional transesophageal echocardiographic images. The novel "aortotomy view" offered by three-dimensional transesophageal echocardiography provided direct visualization and quantification of discrete subaortic stenosis in a dynamic fashion. In summary, three-dimensional transesophageal echocardiography can accurately display and quantify discrete subaortic stenosis and could be a new clinically useful tool for assessing discrete subaortic stenosis and guiding surgical and transcatheter interventions.

Adult↗
PubMed1997

[The effect of endurance training and exhaustive exercise on metallothionein in rats].

To understand physiological role of metallothionein (MT) during exercise, MT levels in liver, brain, heart, lung, blood vessel, skeletal muscle and serum were observed in rats. The results showed that the levels of MT were decreased by 13-34% in lung, liver, heart and skeletal muscle of rats trained by swimming for 10 weeks and were increased by 21%-75% in skeletal muscle, heart, brain, lung and liver of rats after exhaustive swimming respectively, compared with normal control rats. (P < 0.05 and P < 0.01). But the levels of MT in blood vessel and serum were not changed in two groups of rats by swimming for 10 weeks and acute exhaustive swimming (P > 0.05). It is suggested that the different changes of MT levels under physical training and acute exhaustive exercise may be of importance in protection against oxygen free radicals.

Animals↗
PubMed1997

[Effect of dietary arginine on peripheral blood Th/Ts ratio and survival rate in severe burned rats].

The effect of supplemental dietary arginine on dynamic changes in peripheral blood Th/ Ts ratio and survival rate were studied in burned rats (30% TBSA III degree). The results are as follows: 1. Th/Ts ratio dropped on the 3rd day and showed a trough value 10 days postburn. 2. Arginine could prevent the falling of Th/Ts ratio, which was distinct since 5 days after burn. 3. Survival rate 14 days postburn was raised in arginine rats. This study suggests that dietary arginine may be beneficial after severe burn.

Adjuvants, Immunologic↗
PubMed1997

[Experimental study of temporal expression of endogenous TGF alpha in partial thickness scalded wounds].

Investigating spatial and temporal expression and distribution of endogenous TGF alpha, and clarifying its role in burn wound healing. Immunohistochemical and mRNA dot blot hybridization approaches were adopted. Thermal injury can induce TGF alpha gene expression. The expression peaks at the time when repair cells migrate and proliferate most actively, and declines on near completion of epithelialization. Otherwise, the mRNA expression of EGF receptor manifests the same change as TGF alpha's. Immunohistochemical investigation indicates that TGF alpha is mainly distributed in the survived hair follicles and reepithelialized cell layers, and the immunoreactive staining is proportional to epidermal cell growth and migration. Thermal injury can induce endogenous TGF alpha and EGF receptor expression, which is well controlled and correlated with the migration and proliferation of keratinocytes. Endogenous TGF alpha plays a positive role in regulation of wound healing.

Animals↗
PubMed1997

[The role of PMN CD11b/CD18 on the increasing PMN adhesion to endothelial cells induced by severe burn injury].

The process of leukocyte adhesion was mediated by the intercellular adhesion molecular. In this study, both the influence of burn serum on the expression of PMN CD11b/CD18 and the role of CD11b/CD18 on the burn serum stimulated PMN adhesion to endothelial cells (EC) were investigated. The expression of CD11b/CD18 on PMN incubated with burn serum for 2 hours was increased obviously. So was PMN adhesion to EC. Monoclone antibody to PMN CD11b/CD18 could reduce the normal PMN adhesion to EC by half and block the increasing PMN adhesion induced by burn serum. These indicated that PMN CD11b/CD18 may be the main adhesion molecular participating in the increasing PMN adhesion to EC due to severe burn.

Animals↗
PubMed1997

Study on enzyme electrode biosensor of choline.

Choline oxidase was immobilized at a hydrogen peroxide electrode and the enzyme electrode was used for the amperometric determination of choline. The linear range is 0-200 mg/L with a response time of 40 seconds and a 25-microliter sample injection. The relative standard deviation (RSD) is less than 1.5% in 20 assays. The enzyme membrane can be used continuously at 25 degrees C for 60 days. The recovery rate of this method is 100.3-102.3%.

Alcohol Oxidoreductases↗
PubMed1996

Intraoperative transesophageal echocardiography using high-resolution biplane 7.5 MHz probes with continuous-wave Doppler capability in infants and children with tetralogy of Fallot.

This study reports the role of biplane transesophageal echocardiography in monitoring surgical repairs of tetralogy of Fallot. In our patients, 3 repairs were revised based on transesophageal echocardiography and continuous-wave Doppler results, and intraoperative management was altered in 2 others.

Adolescent↗
PubMed1996

Three-dimensional reconstruction of color Doppler flow convergence regions and regurgitant jets: an in vitro quantitative study.

OBJECTIVES: This study sought to investigate the applicability of a current implementation of a three-dimensional echocardiographic reconstruction method for color Doppler flow convergence and regurgitant jet imaging. BACKGROUND: Evaluation of regurgitant flow events, such as flow convergences or regurgitant jets, using two-dimensional imaging ultrasound color flow Doppler systems may not be robust enough to characterize these spatially complex events. METHODS: We studied two in vitro models using steady flow to optimize results. In the first constant-flow model, two different orifices were each mounted to produce flow convergences and free jets--a circular orifice and a rectangular orifice with orifice area of 0.24 cm(2). In another flow model, steady flows through a circular orifice were directed toward a curved surrounding wall to produce wall adherent jets. Video composite data of color Doppler flow images from both free jet and wall jet models were reconstructed and analyzed after computer-controlled 180 degrees rotational acquisition using a TomTec computer. RESULTS: For the free jet model there was an excellent relation between actual flow rates and three-dimensional regurgitant jet volumes for both circular and rectangular orifices (r = 0.99 and r = 0.98, respectively). However, the rectangular orifice produced larger jet volumes than the circular orifice, even at the same flow rates (p < 0.0001). Calculated flow rates by the hemispheric model using one axial measurement of the flow convergence isovelocity surface from two-dimensional color flow images underestimated actual flow rate by 35% for the circular orifice and by 44% for the rectangular orifice, whereas a hemielliptic method implemented using three axial measurements of the flow convergence zone derived using three-dimensional reconstruction correlated well with and underestimated actual flow rate to a lesser degree (22% for the circular orifice, 32% for the rectangular orifice). In the wall jet model, the jets were flattened against and spread along the wall and had reduced regurgitant jet volumes compared with free jets (p < 0.01). CONCLUSIONS: Three-dimensional reconstruction of flow imaged by color Doppler may add quantitative spatial information to aid computation methods that have been used for evaluating valvular regurgitation, especially where they related to complex geometric flow events.

Echocardiography, Doppler, Color↗
PubMed1996

Myocardial imaging with a new transpulmonary lipid-fluorocarbon echo contrast agent: experimental studies in pigs.

The development of echo contrast agents that can provide reliable opacification of the myocardium after intravenous injection is an important advancement for the clinical application of contrast echocardiography. In this study, the hemodynamic effects and echocardiographic characteristics of a new lipid-fluorocarbon echo contrast agent, Aerosomes MRX 115 (ImaRx Pharmaceutical Corp., Tucson, Ariz.) were studied in six anesthetized ventilated pigs. Intravenous injection of this new agent in doses ranging from 0.0005 to 0.01 ml/kg produced significant measurable and visible myocardial opacification without any effect on heart rate, systemic pressure, partial pressure of oxygen, or left ventricular systolic function. The two largest doses (0.005 and 0.01 ml/kg), however, resulted in mild reversible increases in mean pulmonary artery pressure of 12 and 16 mm Hg, respectively. In four animals, epicardial images were obtained before and during coronary artery occlusion. Intravenous contrast injection during coronary occlusion permitted delineation of the hypoperfused myocardial segment. This capability may further expand the utility of contrast echocardiography.

Animals↗
PubMed1996

[Effects of hypertonic sodium lactate dextran resuscitation in severely burned dogs].

12 dogs with 35% TBSA third degree burns received HLD resuscitation (HLD group, n = 6) or LR resuscitation (LR group, n = 6). Fluid resuscitation started one hour postburn. The amount of fluid infused with HLD resuscitation was calculated by that after giving HLD 19.6 ml/kg in 3 hours and 6 ml/kg/% TBSA lactate Ringer's solution followed. The amount of fluid infused with LR resuscitation was calculated by 8 ml/kg/% TBSA lactate Ringer's solution. Infusion of lactated Ringer's solution in both groups was adjusted by maintaining urinary output 0.5-1 ml/kg/h. The volume of fluid infused in HLD group (5.05 +/- 1.11 ml/kg/% TBSA) was much less than that of LR group (10.03 +/- 1.30 ml/kg/%TBSA) (P < 0.01). There was no significant difference in urinary output, serum Na+ and albumin, and plasmacrystalloid osmolarity between two groups. Plasma level of MDA decreased after resuscitation with HLD, which (0.81 +/- 0.20 mmol/g Hb) was much lower than that (1.39 +/- 0.44 mmol/g Hb) of LR group 4 hours postburn (P < 0.05). Plasma SOD activity (7.22 +/- 0.68 u/g Hb) of HLD group were much higher than that of LR group (4.86 +/- 0.53 u/g Hb) 4 hours postburn (P < 0.05). HLD resuscitation could significant reduce the amount of fluid infused comparing with lactate Ringer's solution. HLD resuscitation could attenuate postburn damage to tissue induced by lipid peroxide by elevating plasma SOD activity.

Animals↗
PubMed1995

Factors influencing pulmonary venous flow velocity patterns in mitral regurgitation: an in vitro study.

OBJECTIVES: The aim of this study was to investigate factors affecting pulmonary venous flow patterns in mitral regurgitation. BACKGROUND: Although pulmonary venous flow velocity patterns have been reported to be helpful in assessing the severity of mitral regurgitation, the influence of regurgitant jet direction, pulmonary venous location and left atrial pressures on pulmonary venous flow patterns has yet to be clarified. METHODS: The mitral regurgitant jet was produced by a pulsatile piston pump at 10, 30 and 40 ml/beat through a circular orifice, whereas the pulmonary venous flow was driven by gravity. Four different patterns of pulmonary venous flow and mitral regurgitation were examined. The V wave pressure was set at 10, 30 and 50 mm Hg and pulmonary venous flow velocity at 30 cm/s. Color and pulsed Doppler recordings were obtained with a VingMed 800 scanner interfaced with a computer facilitating digital analysis. RESULTS: The decrease in the velocity time integral of pulmonary venous flow was more prominent for any given volume of mitral regurgitation at higher left atrial pressure. When the mitral regurgitant jet was directed toward the pulmonary vein, a more prominent decrease in the velocity time integral was seen, especially for severe mitral regurgitation (40 ml) with high left atrial pressure (95% vs. 55%, p < 0.001); and the time to peak deceleration of forward flow was significantly shorter (485 vs. 523 ms, respectively, p < 0.01). Also, two different types (laminar and turbulent) of reversed pulmonary venous flow were observed. CONCLUSIONS: Multiple factors, including jet direction, mitral regurgitant volume and left atrial pressure, determine the effect of mitral regurgitation on pulmonary venous flow velocity patterns.

Blood Flow Velocity↗
PubMed1995

Dynamic change in mitral regurgitant orifice area: comparison of color Doppler echocardiographic and electromagnetic flowmeter-based methods in a chronic animal model.

OBJECTIVES: The aim of the present study was to investigate dynamic changes in the mitral regurgitant orifice using electromagnetic flow probes and flowmeters and the color Doppler flow convergence method. BACKGROUND: Methods for determining mitral regurgitant orifice areas have been described using flow convergence imaging with a hemispheric isovelocity surface assumption. However, the shape of flow convergence isovelocity surfaces depends on many factors that change during regurgitation. METHODS: In seven sheep with surgically created mitral regurgitation, 18 hemodynamic states were studied. The aliasing distances of flow convergence were measured at 10 sequential points using two ranges of aliasing velocities (0.20 to 0.32 and 0.56 to 0.72 m/s), and instantaneous flow rates were calculated using the hemispheric assumption. Instantaneous regurgitant areas were determined from the regurgitant flow rates obtained from both electromagnetic flowmeters and flow convergence divided by the corresponding continuous wave velocities. RESULTS: The regurgitant orifice sizes obtained using the electromagnetic flow method usually increased to maximal size in early to midsystole and then decreased in late systole. Patterns of dynamic changes in orifice area obtained by flow convergence were not the same as those delineated by the electromagnetic flow method. Time-averaged regurgitant orifice areas obtained by flow convergence using lower aliasing velocities overestimated the areas obtained by the electromagnetic flow method ([mean +/- SD] 0.27 +/- 0.14 vs. 0.12 +/- 0.06 cm2, p < 0.001), whereas flow convergence, using higher aliasing velocities, estimated the reference areas more reliably (0.15 +/- 0.06 cm2). CONCLUSIONS: The electromagnetic flow method studies uniformly demonstrated dynamic change in mitral regurgitant orifice area and suggested limitations of the flow convergence method.

Animals↗
PubMed1995

[Isolation and identification of a pathogen of grasshoppers].

A pathogen was isolated from natural dead pests of Ceracris kiangsu in Geleshan farm of Chongqin. Its pathogenecity was confirmed by the law of KOCK. It was identified as Pseudomonas pseudoalcaligenes according to its physiological and biochemical properties as well as the G + C content of DNA (63.73mol%). The results of preliminary bioassay show that the pathogen can infect the grasshoppers and Ceracris kiangsu, and also can infect other pests of grassland in a certain extent.

Animals↗