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Biomedical subjects

F Qiu

Publications and source records attributed to F Qiu.

At least 37 records · Page 2Linked to original sources
PubMed1999

Studies on hepatocyte apoptosis, proliferation and oncogene c-fos expression in carbon tetrachloride-induced cirrhotic rat liver.

To investigate the significance of hepatocyte apoptosis, proliferation and oncogene c-fos expression in carbon tetrachloride (CCl4)-induced cirrhotic rat liver. Rat cirrhosis was induced by subcutaneous injection of 50% (v:v 1:1) CCl4. Hepatocyte apoptosis, proliferation and oncogene c-fos expression were examined with TUNEL, PCNA and c-fos immunohistochemical methods in control group and treatment group 72 h, 5, 7, 11 and 15 weeks after CCl4 induction. Hepatocyte apoptosis was rarely seen in control rat liver. The hepatocyte apoptosis was obviously increased 72 h after treatment. Fifteen weeks after treatment, the apoptosis was still more obvious in treatment group than that in controls. PCNA was constantly expressed in CCl4 group, with highest level at middle phase. C-fos was positive 7 and 11 weeks after CCl4 treatment. The results suggest that: 1) apoptosis is involved in rat liver damage at the early phase in CCl4-induced injury, and the process can alleviate nodule reconstruction or eradicate potentially mutational hepatocytes at the later phase; 2) hepatocytes constantly proliferate in CCl4-induced rat liver cirrhosis, especially at the middle phase; 3) c-fos might modulate hepatocyte proliferation in CCl4-induced rat liver cirrhosis.

Animals↗
PubMed1999

Complete isomer-specific 1H and 13C NMR assignments of the heme resonances of rat liver outer mitochondrial membrane cytochrome b5.

Singly and doubly labeled delta-aminolevulinic acid derivatives were used to prepare rat liver outer mitochondrial membrane (OM) cytochrome b5 containing a 13C-labeled heme active site. A variety of NMR experiments, including HMBC and INADEQUATE in conjunction with the more commonly used HMQC, NOESY, and COSY, were conducted to make unambiguous assignments of protonated carbons and the quaternary pyrrole-alpha and -beta carbons in both isomeric forms of the paramagnetic active center of OM cytochrome b5. Because the long interpulse delays in the HMBC experiment have a detrimental effect on the detectability of fast relaxing paramagnetically affected resonances. INADEQUATE is proposed as the experiment of choice for assigning quaternary carbons in paramagnetic hemes with carefully chosen macrocycle labeling patterns. Furthermore, the applicability of the INADEQUATE experiment to paramagnetic heme active sites should be facilitated greatly by the availability of biosynthetic methods for producing isotopically labeled b-hemes and, more recently, isotopically labeled c-hemes.

Aminolevulinic Acid↗
PubMed1999

Kinetic model of phase separation in binary mixtures with hard mobile impurities.

We develop a mean-field rate-equation model for the kinetics of phase separation in binary mixtures with hard mobile impurities. For impurities preferentially wet by one of the components, the phase separation is arrested in the late stage. The "steady-state" domain size depends strongly on both the particle diffusion constant and the particle concentration. We compare theoretical results with the simulation data and find good qualitative agreement.

Journal Article↗
PubMed1999

[Portal hypertensive vasculopathy of splenic artery].

OBJECTIVE: To study the pathological changes of splenic artery wall in portal hypertensive patients. METHODS: The pathological changes and iNOS activity of splenic artery wall were studied in 21 patients with liver cirrhosis and 15 normal subjects, using light and electron microscope and immunohistochemistry. RESULTS: Compared with normal individuals, the splenic artery of cirrhotic patients showed that the intima was thickened, split and broken, and the smooth muscle layer of middle membrane was thicker and migrated to underintima space. In cirrhotic patients, regression, atrophy or hypertrophy and hyperplasia were seen in smooth muscle cells whose contractile phenotype changed to synthetic phenotype as well. iNOS activated obviously. Extracellular matrix increased in the wall, resulting in collagenic and fibrous changes. CONCLUSIONS: Hemodynamic alteration due to liver cirrhosis induced pathological changes of splenic artery, including the damage to contractile structure and increase of iNOS activity. It is one of the reasons of decrease of artery reaction to contractile vasoactive materials.

Adult↗
PubMed1998

Thrombomodulin modulates growth of tumor cells independent of its anticoagulant activity.

Thrombomodulin (TM), recognized as an essential vessel wall cofactor of the antithrombotic mechanism, is also expressed by a wide range of tumor cells. Tumor cell lines subcloned from four patients with malignant melanoma displayed a negative correlation between TM expression and cell proliferation in vitro and in vivo. Overexpression of wild-type TM decreased cell proliferation in vitro and tumor growth in vivo. TM mutants with altered protein C activation capacity lead to a similar effect. In contrast, transfection of melanoma cells with mutant TM constructs, in which a portion of the cytoplasmic or lectin domain was deleted, abrogated the antiproliferative effect associated with overexpression of wild-type TM. Experiments performed with either peptide agonists/antagonists of the thrombin receptor, with hirudin, or with inhibitors of thrombin-TM interaction did not alter the growth inhibitory effect of TM overexpression. These data suggest that TM exerts an effect on cell proliferation independent of thrombin and the thrombin receptor, possibly related to the binding of novel ligands to determinants in the lectin domain which might trigger signal transduction pathways dependent on the cytoplasmic domain.

Animals↗
PubMed1998

An 1H-13C-13C-edited 1H NMR experiment for making resonance assignments in the active site of heme proteins.

In paramagnetic heme proteins, it is often problematic to make proton resonance assignments for heme substituents that do not have large isotropic shifts and consequently lie under the large envelope of polypeptide resonances. Furthermore, assignments that would normally be performed with the aid of HMBC experiments in diamagnetic molecules can prove difficult in the active site of paramagnetic heme proteins if T2(-1) > 2JCH. To circumvent this problem, a new method is presented to selectively detect 1H in 1Hn-13C-13C fragments biosynthetically introduced into the active site of heme proteins. The pulse sequence combines well-known building blocks such as INEPT to transfer 1H spin magnetization to bonded 13C nuclei, followed by INADEQUATE to generate 13C-13C double-quantum coherence that is selected with pulsed field gradients, and finally reverse-INEPT to transfer magnetization back to 1H nuclei for subsequent observation. The new 1Hn-13C-13C edited experiment takes advantage of the relatively large values of 1JCH and 1JCC, avoiding the long interpulse delays in HMBC that compromise the detectability of rapidly relaxing nuclei. The potential applicability of the pulse sequence is demonstrated by its contribution to the unambiguous assignment of the carbonyl carbons in the heme propionates of ferricytochrome b5.

Fourier Analysis↗
PubMed1998

Studies on dammarane-type saponins in the flower-buds of Panax ginseng C.A. Meyer.

From the dried flower-buds of Panax ginseng C.A. Meyer, a new minor dammarane-type triterpene saponin named ginsenoside III together with nine known saponins was isolated. On the basis of spectral and chemical evidence, the structure of the new saponin was elucidated as 3-O-[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-20-O-beta- D-glucopyranosyl-3 beta,12 beta,20(S)-trihydroxy-dammar-25-en-24-one.

Magnetic Resonance Spectroscopy↗
PubMed1998

Influence of octapeptide of cholecystokinin, vasoactive intestinal peptide and substance P on dynamics of biliary system and cardiovascular system.

OBJECTIVE: To examine the effects of cholecystokinin octapeptide (CCK-OP), vasoactive intestinal peptide (VIP) and substance P (SP) on the dynamics of the biliary system and cardiovascular system, and the relationship between the dynamics of the biliary system and cardiodynamics. METHODS: In 91 anesthetized guinea pigs, a triple-lumen, side-hole perfusion catheter (1.0 mmOD) was inserted through the duodenal papilla into the common bile duct (CBD) and the sphincter of Oddi (OS). An end-hole PE-50 catheter was inserted into the left ventricle of heart through the left jugular artery. The left ventricle of heart motility, OS motility and CBD pressure were recorded during the intravenous administration of CCK-OP, VIP, SP and the combination of CCK-OP and VIP. RESULTS: Intravenous CCK-OP increased the fasted OS motility index (MI), decreased the basal pressure in OS, increased CBD pressure, and inhibited the motility of the left ventricle of heart. VIP alone showed no significant effect on the biliary system and cardiovascular system, but when infused together with CCK-OP, it inhibited the effects of CCK-OP on both systems. Exogenous SP acted like CCK-OP on both biliary system and cardiovascular system, but less potently. CONCLUSIONS: The gastrointestinal peptides have important effects on both biliary system and cardiovascular system. There is an important negative correlation between CBD pressure and the motility of the left ventricle of the heart during the infusion of peptides.

Animals↗
PubMed1998

[Timing of surgical treatment for gallstone pancreatitis].

OBJECTIVE: To evaluate the timing of surgery in the treatment of gallstone pancreatitis (GP). METHOD: The records of 53 patients with GP were retrospectively analysed. RESULT: The morbidity and mortality of early surgical treatment (less than 48 hours after admission) were 29.20% and 9.30%, respectively, in contrast to 3.50% and 0 in patients who underwent delayed surgical treatment (more than 48 hours after admission) (P < 0.05). In mild gallstone pancreatitis (APACHE-II 8), the timing of surgery was related to the morbidity and mortality, namely, they were higher in early surgery than in delayed surgery. CONCLUSION: We suggest delayed surgical treatment for mild gallstone pancreatitis, and delayed and selective surgery for severe gallstone pancreatitis.

Female↗
PubMed1997

Role of NFkappaB in the mortality of sepsis.

Binding activity for nuclear factor kappa B (NFkappaB) consensus probes was studied in nuclear extracts from peripheral blood mononuclear cells of 15 septic patients (10 surviving and 5 not surviving). Nonsurvivors could be distinguished from survivors by an increase in NFkappaB binding activity during the observation period (P < 0.001). The increase in NFkappaB binding activity was comparable to the APACHE-II score as a predictor of outcome. Intravenous somatic gene transfer with an expression plasmid coding for IkappaBalpha was used to investigate the role of members of the NFkappaB family in a mouse model of endotoxemia. In this model, increased NFkappaB binding activity was present after injection of LPS. Intravenous somatic gene transfer with IkappaBalpha given before LPS attenuated renal NFkappaB binding activity and increased survival. Endothelial cells and monocytes/macrophages were the major target cells for somatic gene transfer, transfected with an average transfection efficiency of 20-35%. Tissue factor, a gene under regulatory control of NFkappaB, was induced by LPS. Somatic gene transfer with a reporter plasmid containing the functional tissue factor promoter demonstrated NFkappaB-dependent stimulation by LPS. Intravenous somatic gene transfer with IkappaBalpha reduced LPS-induced renal tissue factor expression, activation of the plasmatic coagulation system (decrease of thrombin-antithrombin III complexes) and renal fibrin/fibrinogen deposition. Somatic gene transfer with an expression plasmid with tissue factor cDNA in the antisense direction (in contrast to sense or vector alone) also increased survival. Furthermore, antisense tissue factor decreased renal tissue factor expression and the activation of the plasmatic coagulation system.

Adult↗
PubMed1997

[Interaction of octapeptide of cholecystokinin, vasoactive intestinal peptide and substance P on dynamics of biliary system and cardiovascular system].

We tested in vivo: (a) the effect of an i.v. infusion of cholecystokinin octapeptide, vasoactive intestinal peptide or substance P on dynamics of biliary system and cardiovascular system, (b) the relation of dynamics of biliary system and cardiovascular system. In 91 anesthetized guinea pigs, left ventricle motility of heart, sphincter of Oddi motility and common bile duct pressure were monitored during the intravenous administration of cholecystokinin octapeptide (CCK-OP), vasoactive intestinal peptide (VIP), substance P (SP) and combination of CCK-OP and VIP. Intravenous CCK-OP increased fasting Oddis sphincter motility index, decreased the basal pressure in sphincter of Oddi, increased common bile duct pressure, and decreased the left ventricle of heart motility. VIP alone showed no significant effect on biliary system and cardiovascular system, but in conjunction with CCK-OP it produced inhibition on the effects of CCK-OP on both sides. Exogenous SP acted like CCK-OP on both biliary system and cardiovascular system, but it was less potent. We conclude that it may be an important interaction between dynamics of biliary system and cardiovascular system; and gastrointestinal peptide plays an important role in this interaction in guinea pigs.

Animals↗
PubMed1997

[Twenty-eight alphavirus strains isolated from mosquitoes and ticks captured from Hainan Island, China].

Virus isolation was carried out from mosquitoes and ticks captured in nature from Hainan Island of China from 1983-1988. Twenty-eight non-dengue and non-Japanese encephalitis viral strains were isolated from different places, of which 27 strains were recovered from different species of mosquitoes and 1 strain from ticks. At the Division of Vector-Bore Viral Diseases, National Center for Infectious Diseases, Centers for Disease Control, USA, identification of virus family and virus genus on these 28 viral strains was conducted by the use of a complete set of internationally standardized antibodies against arboviruses and by means of indirect immunofluorescence. Results proved that all these 28 viral strains belonged to the Genus Alphavirus of the Family Togaviridae.

Alphavirus↗