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Biomedical subjects

X Luo

Publications and source records attributed to X Luo.

At least 145 records · Page 8Linked to original sources
PubMed1998

[The influence of adhesion molecules expression to neutrophil aggregation in liver after severe burns].

OBJECTIVE: To elucidate the mechanism of neutrophil aggregation in the liver and the influence of the expression of adhesion molecules after severe burns during early postburn phase, and to explore simultaneously the mechanism of liver damage after severe burns. METHODS: 1. The morphology of the liver and the activation of MPO were observed. 2. The human hepatocytes and hepatic sinusoidal endothelial cells (HSECs) were isolated and cultured, the flow cytometry and micropipette aspiration system were used to observe dynamically the change in intercellular adhesive force between neutrophils and hepatocytes under the influence of burn patient sera. Also the changes in the expression of P-selectin and ICAM-1 on the hepatocytes and HSECs under the influence of burn patient sera were studied. RESULTS: 1. MPO activation was significantly higher than that in the control group, and reached its peak at 6 hours. Three pieces of liver tissue at 6, 12, 24 hours were examined, and it was found that the Disse's spaces were wide and filled with a great number of PMNs. 2. A constitutive expression of P-selectin and ICAM-1 was found in normal hepatic sinusoidal endothelial cells but not in normal hepatocytes. Under the influence of burn patient sera, the expression of P-selectin increased significantly at 1 hour (P < 0.01) in hepatic sinusoidal endothelial cells but not in hepatocytes, and the expression of ICAM-1 increased significantly at 1 and 2 hour (P < 0.01) in hepatocytes and hepatic sinusoidal endothelial cells. 3. In the presence of burn patient sera, the intercellular adhesive force between neutrophils and hepatocytes reached its peak level at 2 hour after co- cultivation and declined thereafter due to the aggravation of hepatocytic injury. After using ICAM-1 Mab in cultured hepatocytes, the adhesive force reduced significantly. CONCLUSION: Neutrophil aggregation in the liver was confirmed after severe burns during early postburn phase. The expression of P-selectin and ICAM-1 on the hepatocytes and HSECs played key roles to neutrophil aggregation in liver after severe burns during early postburn phase, inducing the participation of neutrophils in hepatocyte injury.

Animals↗
PubMed1998

[The effects of hypertonic saline/mannitol resuscitation on the myocardiac contractility and blood pressure of rabbits with hemorrhagic shock].

Eighteen healthy adult male rabbits were hemorrhaged to shock and treated with hypertonic-hyperoncotic solutions in 3 groups (6 per group): hypertonic saline/dextran(HSD), hypertonic saline/mannitol(HSM) and hypertonic acetate/mannitol(HAM). The results showed that HSM. HAM and HSD could raise the left ventricular pressure(LVP), maximum change rate of LVP (+/- dp/dt max) and the arterial blood pressure of hemorrhagic shock rabbits quickly at small dose. The efficiency of HSM was better than that of HSD and HAM (P < 0.05), and the time of blood pressure rise was in accordance with that of LVP and +/- dp/dt max, which may partly explain the mechanism of shock resuscitation by hypertonic-hyperoncotic solution.

Animals↗
PubMed1998

[Protection of hypertonic saline/mannitol to thymic cell apoptosis induced by endotoxin (LPS) in mice].

To observe the effect of HSM (hypertonic saline/mannitol) on thymic cell apoptosis induced by endotoxin (LPS) in mice, twenty-four mice were divided into three groups (8 mice/each group): 1. Control group, each mouse was intraperitonealy injected with normal saline; 2. LPS group, each mouse was intraperitonealy injected with LPS; 3. LPS + HSM group, each mouse was intraperitonealy injected with HSM before and after injection of LPS. The results showed that the percentage of apoptosis of HSM + LPS group was lower than that of LPS group (P < 0.01); the ladder of nucleosomal DNA fragments by agarose gel eletrophoresis of HSM group was not typical as compared with that of LPS group. It is suggested that HSM might protect the apoptosis of mouse thymic cell induced by LPS and may improve the immune function.

Adjuvants, Immunologic↗
PubMed1998

[The effect of brain-derived neurotrophic factor on the rat electroretinography after pressure-induced ischemic injury].

Brain-derived neurotrophic factor (BDNF) or normal goat serum (NGS) was injected intravitreously in each 11 wistar albino rats two days before the induction of ischemia. Retinal ischemia was induced in 22 rats by increasing intraocular pressure to the threshold level which extinguished the electroretinography (ERG) b-wave individually, and maintaining for 90 minutes. The ERG b-wave of the BDNF-treated rats recovered to 80.5 +/- 24.4% of their normal amplitude three days after ischemia, while that of the NGS-treated rats recovered only to 11.1 +/- 5.3%. Statistic analysis showed that the recovery level of ERG b-wave after ischemia in the BDNF and NGS treated rats was significantly different (P < 0.01). The results suggest that BDNF could promote the recovery of the retinal electrophysiologic function from ischemia induced by high intraocular pressure.

Animals↗
PubMed1998

[A rapid simple and reliable method for sequencing the targeted gene of shuttle vector pSP189].

The authors established a simple, rapid and effective procedures for sequencing the targeted a-gene SupF TRNA of shuttle vector pSP189, which is very important and useful in molecular mechanism research of mutagens. In this method, double-stranded plasmid DNA as template, prepared single-stranded DNA with alkali denaturation, applied r-32P-ATP for labelling 5'-end of primer, were used. A satisfactory result was achieved.

Escherichia coli↗
PubMed1998

[Research on bending strength and fracture toughness of alumina-glass composite].

To develop a new ceramic material that can be machined and infiltrated with glass, a porous alumina blank sintered at 1350 degrees C was made of high purity, super fine alpha-alumina and then infiltrated with glass in this study. The density, bending strength and fracture toughness of the partially sintered alumina and alumina-glass composite were determined. The results indicated that the porous alumina density was 2.12 g/cm3, the three point bending strength 102 MPa, the fracture toughness 1.61 MPam1/2; that the alumina-glass composite density was 3.85 g/cm3, the three point bending strength 385 MPa, and the fracture toughness 4.05 MPam1/2. By SEM and EDXA analysis, lanthanum boroslicate glass was completely infiltrated into the 3 mm thick porous alumina blank for 6 h at 1150 degrees C. These suggest that the new developed alumina blank is suited for clinical use.

Aluminum Oxide↗
PubMed1998

[Analysis of 196 cases of trial of labor with borderline oligohydramnios assessed by ultrasound].

OBJECTIVE: To determine the effect of borderline oligohydramnios on perinatal outcome. METHOD: Patients admitted for delivery had an amniotic fluid index (AFI) assessment. Color Doppler was used to examine the systolic/diastolic ratio of the blood flow velocity in fetal umbilical arteries. Normal amniotic fluid volume was defined as an AFI of 8.1-18 cm (n = 200), and borderline oligohydramnios as 5.1-8.0 cm (n = 196). The two groups were compared on perinatal outcomes as all of the patients had trial of labor. RESULTS: There was no difference in the incidence of fetal distress and neonatal mortality between the two groups. The incidence of emergency section in borderline oligohydramnios group was significantly higher. CONCLUSION: The patients with borderline oligohydramnios may have a trial of labor under proper intensive care.

Female↗
PubMed1998

[Experimental study on reducing effect of shexiang baoxin pill from damage of arterial wall caused by hyperlipemia].

OBJECTIVE: To study the protecting effect of Shexiang Baoxin Pill (SXBXP) on arterial wall in hyperlipemia rabbit model. METHODS: Thirty-six male, New Zealand rabbits were randomized into three groups: control group, fed with common diet for 8 weeks: Hypercholesterolemia group (HC) and SXBXP group (SX), fed with 1% cholesterol and 3% lard diet for 8 weeks. In SX group, SXBXP was iven from 7th week for 2 weeks. The plasma levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were measured at the first, 6th and the 8th week of experiment. Serum superoxide dismutase (SOD) and electrocardiography (ECG) were also evaluated at the 8th week. Light microscopy and transmission electron microscopy were adopted to assess the degree of pathologic damage of arterial wall. RESULTS: SXBXP could reduce the levels of serum TC and LDL-C, as compared with the HC group, P < 0.05. It could also reduce the extent of atherosclerotic lesion and the severity of intimal proliferation. CONCLUSION: SXBXP has the effect of inhibiting development of experimental atherosclerosis.

Animals↗
PubMed1998

[Post diameter optimal design of over dentures attachment].

OBJECTIVE: The effect of the post diameter design of over dentures attachment on the strss distribution of pulpless dentine was investigated in this study. METHODS: The optimal post diameter design was computed with a finite element method and analyzed with graphic method. RESULTS: The changes between the dentine stress value and the post diameter was parabola relationship. The optimal diameter of attachment post was 1.55 mm for this study model. The dentine thickness which retained above apical foramen 4 mm was 0.83 mm. CONCLUSION: This investigation provides a series of valuable parameters for making a post diameter optimal design of over dentures attachment.

Denture Design↗
PubMed1998

[Three dimensional finite element analysis on the mandibular complete overdenture supported by nature roots or implants].

OBJECTIVE: To investigate the stress distribution around the bone tissue of overdenture supported by teeth roots or implants in the process of mastication which may assist to improve the design of the dentures. METHODS: By means of CT scan, CAD and a three distribution finite element methods to study the stress distribution of the supporting tissue of overdenture supported by roots or implants when various attachment retentive apparatus and various bite forces were applied. RESULTS: No matter overdenture supported by roots or implants the stress distribution on bone tissue are difference between the bar and stud attachments, However these difference were minor compared with the difference caused by the direction of force. The stress value of cortical bone around the roots or implants with twenty degree oblique force is 2.2-3 times higher than that with vertical force. Overdenture supported by implants produced 2.5-4 times higher stress in the cortical bone around than that of overdenture supported by roots when various superstructures or various loads were applied. CONCLUSION: It must consider to reduce the stress peaks and provent bone resorption by increasing the number of implants and using the force-breaking design of implant super-strcture when the overdenture were supported with implants only.

Dental Implants↗
PubMed1998

[The influence of pressure on human lamina cribrosa cell and its collagen synthesis].

OBJECTIVE: To study the influence of pressure on human lamina cribrosa cell (HLC) and its synthesis of collagen. METHOD: HLCs were cultured in vitro and submitted to elevated hydrostatic pressure, their changes in morphology were observed by light and electron microscopy and their synthesis of collagen was measured with fluorescence spectrophotometer. RESULTS: Under a hydrostatic pressure of 6.67 kPa (1 kPa = 7.5 mmHg), the flat and polygonal HLCs became elongated. Vacuoles appeared in the cytoplasm and increased as the pressure persisted. The mitochondria were swollen, some of them turned into vacuoles, and myelin figures were found in the cytoplasm. When exposed to elevated pressure for 3 days, the amounts of synthesized collagen type I, III, IV were 43.95 +/- 6.37, 61.35 +/- 10.35 and 82.90 +/- 11.36 arbitrary unit (AU) by fluorometry respectively, and compared to controls, they were statistically significantly (P < 0.05) increased; after 5 days of pressure exposure, the amounts were 33.50 +/- 6.94, 40.85 +/- 12.30 and 80.45 +/- 14.65 AU, e.g., still increased. CONCLUSION: It is indicated that under pressure, HLCs undergo obvious morphological changes and increase their synthesis of collagen types I, III and IV.

Collagen↗
PubMed1998

[The effect of elevated hydrostatic pressure on expression level of type III collagen mRNA by lamina cribrosa cells in vitro].

OBJECTIVE: To investigate the effect of elevated hydrostatic pressure on the expression level of type III collagen mRNA by lamina cribrosa cells (LCCs) and approach the action of changes of extracellular stroma on glaucomatous optic nerve damage. METHODS: LCCs were cultured and submitted to elevated hydrostatic pressure (4.67 - 5.33 kPa). We observed collagen type III mRNA level by dot-blot hybridization and computer imaging analysis. RESULTS: Under the pressure for 3 days, the amounts of collagen III mRNA were 0.5828 +/- 0.0517 in optical density (OD), compared with the same period controls (0.2832 +/- 0.0613), the difference was statistically significant (P < 0.05). When exposed to pressure up to 6 days, the collagen III mRNA level remained somewhat higher than that of the control, but there was no significant difference (P > 0.05). After 9 to 12 days of exposure to pressure, the mRNA amounts were decreased respectively to 0.3246 +/- 0.0957 and 0.2164 +/- 0.0171 in OD that were lower than that of the control in the respective same periods, and the differences between the experimental and the control had no significance (P > 0.05). CONCLUSION: Elevated hydrostatic pressure may increase expression level of collagen III mRNA by LCCs in a certain period.

Collagen Type III↗
PubMed1998

[A clinical study on reducing immunologic rejection in combining corneal lamellar autografting with allografting].

OBJECTIVE: To reduce the rate of immunologic rejection, corneal lamellar autografting with allografting were combined, making immune cells less attack on allograft. METHODS: The pterygium having encroached upon the pupillary area was removed surgically, and the combination of autograft with allograft was transplanted on the peripheral and central cornea in 23 cases (24 eyes). The control group of 13 cases (13 eyes) was established in which the pterygium and dermoids were removed, and lamellar allografts were transplanted. The rate of rejection and their effects were compared. RESULTS: The rate of transparent autograft and allograft was 100%, no rejection and recurrence of pterygium occurred in any case in the combined group, while in the control group, the rejection rate was 30.8% and recurrence rate, 20.0%. CONCLUSION: The combination of lamellar autografting with allografting can reduce the rate of rejection and recurrence of pterygium.

Adult↗
PubMed1998

[Application of statistical simulation spectrophotometry to the determination of four medicaments in feibaosanxiao tablets].

The steps of statistical simulation spectrophotometry are to build a model based on a collection of limited but sufficient data from simulation samples to reveal the real absorbance-concentration relationship of the real sample and provide concentrated data of the individual components of the real sample measured by its absorbance data at several sensitive wavelengths. In this article, the method of stepwise regression has been used for building absorbance-concentration model of Feibaosanxiao tablets, a compound formulation of multimedicaments, and uniform design, for experimental design and recovery test. Recoveries of the four medicaments, acetaminophen, phenytoin sodium, theophylline and caffeine were 99.6%, 97.4%, 100.7% and 100.7% with RSD 0.3%, 1.9%, 1.3% and 1.3% respectively (n = 14).

Acetaminophen↗
PubMed1998

A new species of Anopheles hyrcanus group from Nei Mongol Autonomous Region (Diptera:Culicidae).

Morphology of Anopheles (Anopheles) hailarensis, a new species belonging to the Anopheles hyrcanus group, collected from Hailaer, Nei Mongol Autonomous Region, P. R. of China, is described in adult, pupal, larval and egg stages. It is closely related to Anopheles sinensis Wiedemann, 1828 and Anopheles heiheensis Ma, 1981. Comparisons on adult morphology among above three species and egg morphology between the new species and Anopheles sinensis are made.

Animals↗
PubMed1998

[Comparison of the morphology of wing spot between Anopheles minimus and Anopheles fluviatilis].

AIM: To compare the morphology of wing spot between Anophelesminimus Theobald, 1901 and Anopheles fluviatilis James, 1902 and find out the reliable diagnostic characteristics. METHODS: Anopheles minimus were collected from Jinuo Village, Jinghong County, Yunnan Province. Anopheles fluviatilis were collected from Lingyun County, Guangxi Zhuang Autonomous Region. Measurements of the wing-length and the length of pale and dark spots on the costa and V1 were made with a microscope fitted with an ocular micrometer. RESULTS: A total of 52 females and 60 males of Anopheles minimus and 40 females and 60 males of Anopheles fluviatilis were examined. It was found that the presence of presecutor pale spot and the ratio of sector pale spot to sector dark spot were the important diagnostic morphological characteristics between the above mentioned two species. CONCLUSION: Obvious differentiations exist in the morphology of wing spots between Anopheles minimus and Anopheles fluviatilis.

Animals↗
PubMed1998

[The three-dimensional analysis of mandibular overdenture supported by implants].

In recent decade, the treatment in which two or four implants are placed in an edentulous patient to support an overdenture has been more effective and safe, and the retention and stability of overdenture have been improved by the use of attachments fabricated on implant abutments. This study aimed to investigate the supporting tissue stress distributions of implant-overdenture with a 3-D finite element model built by CT scan and CAD technology when various attachments and loads were used respectively. The results demonstrated that the establishment of the three-dimensional finite element model with CT scan and CAD technique had saved time and effort, and it did not damage the experiment model. The tissue structure was quite distinct in imaging. In terms of the stress distribution of bone tissue in the overdenture supported by implant, there was a difference between bar attachment and stud attachment. However, such a difference was minor as compared with the difference caused by the bite force direction. The stress value of cortical bone around abutment with 20 degree oblique force was 2.2-3 times that with vertical force. Therefore, to reduce high stress peaks, attention must be paid to the direction of the bite force, as this variable is much more important than the design of superstructure.

Aged↗