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Biomedical subjects

X Fu

Publications and source records attributed to X Fu.

At least 73 records · Page 4Linked to original sources
PubMed1998

Heterogeneity of myocardial edema in isolated pig hearts after perfusion with different types of cardioprotective solutions.

The extent and distribution of myocardial edema induced by perfusion with cardioprotective solutions is of great interest. Domestic pig hearts (n = 12) were perfused in situ after aortic cross clamping either with Bretschneider's cardioplegic solution (HTK, 4 degrees C, n = 3), with a heparinized Krebs-Henseleit solution containing 30 mmol/L 2,3 Butanedionemonoxime (BDM, 4 degrees C, n = 3) or with heparinized pig blood (HPB, 24 degrees C, n = 3). After a three-hours storage period, magnetic resonance tomography (MRI) was carried out. The acquired T1-weighted data were used for the subsequent three-dimensional reconstruction based on the "Heidelberg ray-tracing technique". The small myocardial tissue blocks (n = 216) were excised from these hearts for dry weight measurements for 9 preselected regions in duplicate including ventricular papillary muscle, ventricular free wall, ventricular septum, apex, and atrial tissue. In control hearts (n = 3), dry weight was measured immediately after explantation (no MRI). The results of dry-weight measurements and three dimensional visualization were compared. Dry-weight measurements revealed that considerable myocardial edema is induced by any of the experimental procedures. The effects were most pronounced after BDM perfusion. Regardless how the edema was induced, there were significant differences of the water content within the heart: the water content in the heads of the papillary muscles and in the interventricular septum was always smaller than that of the free left- and right-ventricular walls. The heterogeneity of myocardial edema and its spatial distribution pattern could be qualitatively visualized. The experimental data (biophysical data and 3D visualization) clearly show a heterogeneity of myocardial edema induced by different types of cardioprotective solutions. As the presence of myocardial edema represents one of the crucial events in the pathophysiology of myocardial dysfunction occurring during myocardial infarction, ischemia, heart transplantation, and extracorporeal circulation, the present study represents an interesting contribution towards intravital detection and distribution of myocardial edema.

Animals↗
PubMed1998

Progesterone increases cAMP release and accumulation in isolated term human myometrium.

OBJECTIVE: To study the relationship between the action of progesterone on term human myometrial contractile activity and cAMP alterations. STUDY DESIGN: Myometrial tissues were obtained from 13 term pregnant women who underwent elective cesarean section. The contractile activity of muscle strips was recorded isometrically, and the level of cAMP in both superfusion media and experimental biopsies was measured by radioimmunoassay. RESULTS: An increased cAMP release into the superfusion media and an increased accumulation of cAMP in myometrium were observed after the addition of progesterone (3, 15 and 150 microM). Simultaneously, the frequency and tonus of contractions were increased, while the amplitude and activity area of contractions were decreased. CONCLUSIONS: The data indicate that an increase in cAMP concentration plays a role in the action of progesterone on the regulation of term human myometrial contractile activity.

Adult↗
PubMed1998

The effects of fibroblast growth factors on ischemic kidney, liver and gut injuries.

OBJECTIVE: To explore the possibility of reducing reperfusion injuries of internal organ with acidic and basic fibroblast growth factors (aFGF and bFGF). METHODS: Two kinds of ischemia and reperfusion animal models were used in this study. In rat model of superior mesenteric artery (SMA) occlusion, microvascular clamp was placed on the root of SMA to cut off the blood flow for 45 minutes, and then the clamp was removed. In rat model of bilateral renal ischemia and reperfusion, both renal arteries were clipped to get complete cessation of blood flow for 60 minutes, then the blood flow was allowed to return. At the onset of reperfusion, the doses of 4.0 micrograms/rat of bFGF in SMA occluded rats or 2.6 micrograms/rat of aFGF in rats with acute renal injury were administered through the jugular vein. The liver and renal function examination, tissue bacterial study and histopathological evaluation were done to evaluate the treatment results. RESULTS: The functional impairment of ischemic liver, gut and kidney were reduced with venous administration of aFGF or bFGF at the onset of reperfusion. The results of pathological and tissue bacterial examination supported the assertion of significant protective effects of FGFs. CONCLUSIONS: The protective effects of FGFs may come from the non-mitogenic effects of FGFs at the early and the mitogenic effects at the late stage of tissue repair. These results indicate a potential for clinical use of FGFs as a therapeutic modality in ischemic visceral organ injuries in the future.

Animals↗
PubMed1998

[Basic fibroblast growth factor (bFGF) and wound healing: a multi-centers and controlled clinical trial in 1024 cases].

UNLABELLED: To evaluate the effects of bFGF on wound healing and the side-effects of bFGF, a multi-centers and controlled clinical trial were carried out in 32 hospitals in China. One thousand and twenty-four cases with acute wounds such as burn, donor site or operative wound and chronic wounds such as bed sore, draining sinus, ulcer were treated with bFGF. Another 826 cases with the similar wounds were used as control. The results showed: 1. The duration of wound healing was shorted 3-4 days in trial group when compared with the contorl; 2. The successful rates from bFGF on promoting the wound healing for burns, operative wounds and chronic dermal ulcers was 95.2%, 96.5% and 93.5%, respectively; 3. No adverse reaction was found. CONCLUSION: 1. bEGF can make the "silent" reparative cells dividing and proliferating. 2. bFGF can improve the quality and the velocity of wound healing.

Administration, Topical↗
PubMed1998

[Fibronectin mRNA expression in hypertrophic scars].

OBJECTIVE: This study was to compare the content of fibronectin messenger RNA in the normal skin and hypertrophic scars. METHODS: The mRNA levels of fibronectin were measured by quantitative RT-PCR. RESULT: The study revealed that in vivo, the content of fibronectin messenger RNA was higher in hypertrophic scars than in normal skin. CONCLUSION: It indicates that altered regulation of extracellular matrix components is an important factor for abnormal human wound healing.

Adolescent↗
PubMed1998

[Detection of 17-ketosteroid and 17-hydroxycorticosteroid in urine after separation and collection by foam rubber].

Using foam rubber 17-ketosteroid (17-KS) and 17-hydroxycorticosteroid (17-OHCS) were separated and collected in urine. 17-KS and 17-OHCS were eluted down from the foam rubber with alcohol, colour reaction can be respectively produced by m-dinitrobenzene and phenyhydrazine hydrocholoride, then both of them were detected by spectro-photometry. The standard deviation of this method was +/- 0.032, and its minimum detectable concentration was 0.01 microgram.ml-1. The recovery rate of 17-KS and 17-OHCS estimation was from 99.0% to 101.0%, with co-efficients of variation less than 6.23%.

17-Hydroxycorticosteroids↗
PubMed1998

[Ischemia and reperfusion reduce the mRNA expression of endogenous basic fibroblast growth factor (bFGF) in rat skeletal muscles].

OBJECTIVE: To explore the expression of bFGF gene in normal and wounded rat skeletal muscles. METHODS: In situ hybridization and quantitative PCR methods were used to evaluate the location of basic fibroblast growth factor (bFGF) mRNA and the amount of bFGF mRNA expression in normal, ischemic or ischemic and reperfused rat skeletal muscles. RESULTS: According to the intensity of the stain in situ hybridization, four main classes of fibers could be identified: strong, moderate, weak and negative stained fibers. bFGF mRNA was found in the cytoplasm in both normal and wounded muscles; however, the signal intensity was much stronger in normal muscles. In the normal muscles, bFGF mRNA was distributed irregularly and sparsely, and 82% of fibers had positive bFGF mRNA staining, and only 52% and 22% of fibers in ischemic or ischemic and reperfused muscles were positive for bFGF mRNA staining in situ hybridization. The results in quantitative PCR study supported the concept of the reduced bFGF mRNA expression in the wounded muscles. CONCLUSIONS: The loss of stored bFGF in wounded skeletal muscles as we showed previously is also caused by its increased damage and reduced secretion.

Animals↗
PubMed1998

[Clinical study on tripterygium wilfordii complex ester tablet in treating rheumatoid arthritis].

OBJECTIVE: To observe the curative effect, toxic and side effect of Tripterygium Wilfordii Complex Ester Tablet (TWT, a preparation of Folium Tripterygium wilfordii) in treating rheumatoid arthritis. METHODS: Two hundred and seventy seven patients were observed with prospective, multicentric and random double-blind control method. One hundred and forty cases of TWT group were treated with TWT 2 tablets each time, 3 times a day orally, and the other 137 cases treated with Tripterygium Wilfordii Polycoside Tablet (TPT, a preparation of Radix Tripterygium Wilfordii) 2 tablets each time were taken as control, 3 times a day orally. The therapeutic course for both groups was 6 weeks. RESULTS: The markedly controlled rate of the TWT group was 26.71% and the total effective rate was 86.43%, while those in the control group were 26.28% and 83.94% respectively, the difference between the two groups was insignificant (P > 0.05). The occurrence of side-effect in the two groups was 20.00% and 23.35% respectively, also showed no significant difference (P > 0.05). CONCLUSION: The Folium Tripterygium Wilfordii preparation is similar in efficacy and security to the Radix Tripterygium Wilfordii preparation.

Adolescent↗
PubMed1997

Titration kinetics of Asp-85 in bacteriorhodopsin: exclusion of the retinal pocket as the color-controlling cation binding site.

The spectrum (the purple blue transition) and function of the light-driven proton pump bacteriorhodopsin are determined by the state of protonation of the Asp-85 residue located in the vicinity of the retinal chromophore. The titration of Asp-85 is controlled by the binding/unbinding of one or two divalent metal cations (Ca2+ or Mg2+). The location of such metal binding site(s) is approached by studying the kinetics of the cation-induced titration of Asp-85 using metal ions and large molecular cations, such as quaternary ammonium ions, R4N+ (R = Et, Pr, a divalent 'bolaform ion' [Et3N+-(CH2)4-N+Et3] and the 1:3 molecular complex formed between Fe2+ and 1,10-phenanthroline (OP). The basic multi-component kinetic features of the titration, extending from 10(-2) to 10(4) s, are unaffected by the charge and size of the cation. This indicates that cation binding to bR triggers the blue --> purple titration in a fast step, which is not rate-determining. In view of the size of the cations involved, these observations indicate that the cation binding site is in an exposed location on, or close to, the membrane surface. This excludes previous models, which placed the color-controlling Ca2+ ion in the retinal binding pocket.

Aspartic Acid↗
PubMed1997

Time-resolved titrations of ASP-85 in bacteriorhodopsin: the multicomponent kinetic mechanism.

The Asp-85 residue, located in the vicinity of the retinal chromophore, plays a key role in the function of bacteriorhodopsin (bR) as a light-driven proton pump. In the unphotolyzed pigment the protonation of Asp-85 is responsible for the transition from the purple form (lambdamax = 570 nm) to the blue form (lambdamax = 605 nm) of bR (pKa = 3.5 in 20 mM NaCl). The Purple <=> Blue transition can also be induced by deionization (cation removal). These color changes offer a unique opportunity for time resolving the titration of a protein residue using conventional stopped-flow methodologies. We have studied the Purple <=> Blue equilibration kinetics in bR by exposing the system to pH and to cation jumps. Independently of the equilibration direction (Purple-->Blue or Blue-->Purple) and of the inducing concentration jump ([H+] or [cation]), the kinetics are found to exhibit analogous multicomponent features. Analysis of the data over a range of cation concentrations and pH values leads to the conclusion that the rate-determining step in the overall titration of Asp-85 is proton translocation through a specific proton channel. The multicomponent kinetics, extending over a wide time range (10(-2)-10(4) s), are accounted for in terms of a pH-dependent heterogeneity of proton channels. A model is presented in which the relative weight of four proton channels is determined by the state of protonation of two interacting, channel-controlling, protein residues A1 and A2. These findings bear on the mechanism of the vectorial proton translocation associated with the photocycle of bR.

Aspartic Acid↗
PubMed1997

Glucocorticoid regulation of natural cytotoxicity: effects of cortisol on the phenotype and function of a cloned human natural killer cell line.

The ability of glucocorticoids to suppress cellular immune functions, including the cytotoxic activity of natural killer cells, is well known. However, the molecular mechanism(s) of glucocorticoid-mediated suppression of cellular cytotoxicity mediated by natural killer cells is not understood. We have investigated the effects of cortisol on protein expression and cytotoxic function of natural killer cells using NK3.3, a well-characterized, cloned human natural killer cell line. Cortisol, at concentrations up to 2 microM, does not significantly alter the viability or proliferative capacity of NK3.3 cells. However, micromolar concentrations of cortisol induce the expression of a small set of proteins which are not synthesized by NK3.3 cells in the absence of cortisol, and repress the synthesis of another set of proteins including several phenotypic determinants and cytokines. In the presence of added cortisol, the synthesis of perforin mRNA was partially repressed. However, the most striking effect of cortisol on this NK clone was its repression of granzyme A synthesis. In conjunction with the downregulation of adhesion proteins, NK3.3 cells cultured in the presence of cortisol exhibit a reduced capacity to form conjugates with K562 target cells. Whereas cortisol treatment of NK3.3 cells causes an approximately 50% decrease in their ability to form conjugates with K.562 target cells, the cytotoxic function of these cells is completely abolished under the same conditions. This first report of hormonal regulation of granzyme expression and the strong correlation between granzyme A repression and cytotoxic function suggests that cortisol may regulate NK function by repression of granzyme A synthesis. In addition to demonstrating the significant influence of cortisol on natural killer cell function, these studies provide a model system for elucidation of molecular mechanism(s) whereby glucocorticoids repress cellular immune function, especially with respect to natural killer cells.

Anti-Inflammatory Agents↗
PubMed1997

Anisomycin and verapamil influence the action of progesterone on regulation of term human myometrial contractile activity.

OBJECTIVE: Progesterone has been shown to have both stimulatory and inhibitory effects on term human myometrial contractile activity. The mechanisms involved in this action of progesterone are still poorly understood. DESIGN: Myometrial tissues were obtained from the lower uterine segment at elective Caesarean section of 30 term pregnant women. The contractile activity of muscle strips was measured by a superfusion technique and protein synthesis evaluated by [3H]-leucine incorporation. RESULTS: [3H]-leucine incorporation into term myometrial strips was not affected by progesterone (10 mumol/l), but was markedly reduced by the protein synthesis inhibitor anisomycin (P < 0.05). However, progesterone increased frequency and tonus of contractions and reduced the activity-area of contractions (P < 0.01). Anisomycin (100 mumol/l) did not change these effects or the spontaneous contractile activity. Removal or extracellular Ca2+ or addition of the L-type calcium channel blocker verapamil prevented the spontaneous as well as the progesterone-induced contractions, but had less pronounced effects on contractions initiated by oxytocin. CONCLUSION: The results indicate that the actions of progesterone on term myometrial contractile activity occur without protein synthesis and that increased Ca2+ influx or decreased outward transport of Ca2+ may play a possible role)

Adult↗
PubMed1997

Basic fibroblast growth factor reduces the gut and liver morphologic and functional injuries after ischemia and reperfusion.

OBJECTIVE: To explore the possible effects of basic fibroblast growth factor (bFGF) on ischemic gut and liver injuries after trauma. METHODS: Animal models of superior mesenteric artery occlusion (45 minutes) and reperfusion (3 days) were used in this study. Seventy-two Wistar rats were divided into three groups of 24 rats each. The animals in bFGF-treated group were injected with 4 microg bFGF/rat in 0.15 mL normal saline solution containing heparin 0.1% (w/v) through the jugular vein at the onset of reperfusion. In the normal saline control group, all rats received the same vehicle, but without bFGF. Group 3 (sham-operated) underwent the same laparotomy procedure, but without superior mesenteric artery occlusion. Liver function parameters, the levels of serum tumor necrosis factor alpha, nitric oxide, superoxide dismutase, malondialdehyde (MDA), tissue bacterial examination, and pathologic study were used to evaluate the results. RESULTS: In bFGF-treated rats, the amounts of serum alanine transaminase and aspartate aminotransferase and serum tumor necrosis factor-alpha were reduced significantly at 6, 24, and 48 hours when compared with normal saline-treated rats. However, the changes in nitric oxide, superoxide dismutase, and MDA varied from each other as a function of time after injury. The amounts of nitric oxide were increased significantly at 6 hours in intestine in normal saline-treated rats and in liver in bFGF-treated rats (p < 0.05). At 6 hours after reperfusion, the activity of superoxide dismutase in normal saline-treated rats were much lower in liver than those in bFGF-treated and sham-operated rats (p < 0.05), but the levels of MDA were increased in intestine in bFGF-treated rats and in liver in normal saline-treated rats when compared with sham-operated rats (p < 0.05). At 24 hours, the levels of MDA in normal saline-treated rats were much higher than those in both bFGF and sham-operated rats (p < 0.05). Bacterial examination revealed that the ratio and the amounts of bacterial translocation from gut to liver, spleen, and mesenteric lymph nodes in bFGF-treated rats were much lower than those in normal saline-treated rats. The results of pathologic study support the assumption that bFGF provided protective effects against reperfusion injury. CONCLUSIONS: Intravenous administration of bFGF may benefit in reducing gut and liver injuries after ischemia and reperfusion. The mechanisms of those effects may involve mitogenic and nonmitogenic effects of bFGF.

Animals↗
PubMed1997

E2a-Pbx1 induces aberrant expression of tissue-specific and developmentally regulated genes when expressed in NIH 3T3 fibroblasts.

The E2a-Pbx1 oncoprotein contains the transactivation domain of E2a joined to the DNA-binding homeodomain (HD) of Pbx1. In mice, E2a-Pbx1 transforms T lymphoblasts and fibroblasts and blocks myeloblast differentiation. Pbx1 and E2a-Pbx1 bind DNA as heterodimers with other HD proteins whose expression is tissue specific. While the transactivation domain of E2a is required for all forms of transformation, DNA binding by the Pbx1 HD is essential for blocking myeloblast differentiation but dispensable for fibroblast or T-lymphoblast transformation. These properties suggest (i) that E2a-Pbx1 causes cellular transformation by activating gene transcription, (ii) that transcription of E2a-Pbx1 target genes is normally regulated by ubiquitous Pbx proteins and tissue-specific partners, and (iii) that DNA-binding mutants of E2a-Pbx1 activate a subset of all gene targets. To test these predictions, genes induced in NIH 3T3 fibroblasts by E2a-Pbx1 were identified and examined for tissue- and stage-specific expression and their differential abilities to be upregulated by E2a-Pbx1 in NIH 3T3 fibroblasts and myeloblasts and by a DNA-binding mutant of E2a-Pbx1 in NIH 3T3 cells. Of 12 RNAs induced by E2a-Pbx1, 4 encoded known proteins (a J-C region of the immunoglobulin kappa light chain, natriuretic peptide receptor C, mitochondrial fumarase, and the 3',5'-cyclic nucleotide phosphodiesterase, PDE1A) and 5 encoded new proteins related to angiogenin, ion channels, villin, epidermal growth factor repeat proteins, and the human 2.19 gene product. Expression of many of these genes was tissue specific or developmentally regulated, and most were not expressed in fibroblasts, indicating that E2a-Pbx1 can induce ectopic expression of genes associated with lineage-specific differentiation.

3T3 Cells↗
PubMed1997

[The expression of proliferating cell nuclear antigen in breast phylloides cystosarcoma and its significance].

OBJECTIVE: To investigate the expression of proliferating cell nuclear antigen (PCNA) in breast phylloides cystosarcoma and its clinicopathological signification. METHODS: Immunohistochemistry (SP method) with monoclonal antibodies PC10 against PCNA was performed in 100 cases of phylloides cystosarcoma and 39 cases of adenofibroma. RESULTS: The positive rate of PCNA in phylloides cystosarcoma was 86%. The average PCNA index (PI) of phylloides cystosarcoma was significantly different among every histologic grading (F = 85.33, P < 0.01). The degree of differentiation was lower, the PI was higher. The PI was closely correlated with histologic grading (r's = 0.77). The PI in grade I phylloides cystosarcoma was higher than that in the group of adenofibroma with abundant mesenchymal cells (t = 3.42, P < 0.01). There was only a low correlation between PI and mitotic figures in phylloides cystosarcoma (r = 0.39). CONCLUSIONS: These findings suggest that the detection of PCNA has considerable practical value in reflecting the proliferation of activity of phylloides cystosarcoma, assisting the pathologists to make histologic grading; distinguishing the malignancy from benign ones (differential diagnosis) and evaluating the prognosis.

Adenofibroma↗
PubMed1997

[Uterine activity in active phase].

This study was designed to understand the uterine activity (UA) in normal labor. 43 nulliparous women(33 in normal course of labor and 10 in abnormal course of labor) were in the active phase of spontaneous labor with cephalic presentation for vaginal delivery. An open-end fluid filled intrauterine catheter connected to a pressure transducer was used to measure the uterine contraction intensity, frequency and duration. UA was quantified by means of Montevideo Unit (MU) and Uterine activity integral(UAI). The receiver operator characteristic(ROC) curve defined the cut-off points of UA between normal labor and abnormal labor. The results showed that MU and UAI were correlated with the rate of cervial dilatation in the active phase of labor (r = 0.3734 and 0.3502 respectively, P < 0.05). There was a strong correlation between MU and UAI (r = 0.7173, P < 0.001). The mean of UA in normal labor as MU = 226(s = 68.45) mmHg/15 min. UAI = 901(s = 258.02) kPa/15 min. The minimum of UA to normal labor in MU was 170 mmHg/15 min, of UAI 650 kPa/15 min. The study suggests that quantification of UA is very useful in the management of labor, especially in the proper use of oxytocin in cases abnormal labor.

Female↗