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Biomedical subjects

C Xu

Publications and source records attributed to C Xu.

At least 145 records · Page 8Linked to original sources

[Effects of protocol HX-97 on mobilization, collection and hematopoietic reconstitution of peripheral blood stem cells transplantation].

In order to enhance the effects of peripheral blood stem cell mobilization, collection and hematopoietic reconstitution, we observed and evaluated the effects of Protocol HX-97 on 22 patients who received allogeneic or autologous peripheral blood stem cell transplants from April 1997 to June 1999. rhG-CSF was used for mobilization at a dose of 300 micrograms/day for 6 days; the sixth dose was given an hour and a half before leukapheresis. High dose chemotherapy and rhG-CSF were given for autologous peripheral blood stem cell mobilization; the chemotherapy should be intensive enough to reduce the patients' peripheral WBC to less than 1.0 x 10(9)/L, and the beginning of using rhG-CSF should be just at the time of WBC's rising from the nadir. rhGM-CSF and rhG-CSF were given sequentially for hematopoietic reconstitution after transplantation. The results showed that leukaphereses were successfully performed for peripheral blood stem cell collection. Sixteen cases needed apheresis only once, and 6 cases needed it twice. The harvests were 2.5-10.7 x 10(8)/kg MNC, 2.5-20.0 x 10(6)/kg CD34+ cells (including 1.8-7.5 x 10(6)/kg CD34+CD33-, 0.7-12.5 x 10(6)/kg CD34+CD33+), and 3.5-6.3 x 10(5)/kg CFU-GM. Hematopoietic function recovered to > 0.5 x 10(9)/L of neutrophil count in allo-PBSCT at 14-20 days and in auto-PBSCT at 12-20 days, and to > 20 x 10(9)/L of platelet count in allo-PBSCT and in auto-PBSCT at 16-34 days and 16-28 days, respectively. At day +30 post-transplantation, chromosome analysis and DNA finger print assessment of bone marrow cells indicated that the patients' hematopoietic function had been reconstituted. This study suggests that Protocol HX-97 is an effective approach to mobilization of peripheral blood stem cell transplantation, and it is relatively cost-effective.

Adult↗

Dietary L-arginine attenuates expression of vascular cell adhesion molecule-1 in the aortae of hypercholesterolemic rats.

OBJECTIVE: To determine whether the antiatherogenic effect of L-arginine is due to an inhibition of vascular cell adhesion molecule-1 (VCAM-1) expression in the aortae of hypercholesterolemic rats. METHODS: Twenty-four male Wistar rats were randomized into three groups: Group NC with normal diet (NC, n = 8), Group CC with 4% cholesterol and 1% cholic acid diet (CC, n = 8), Group AC with 4% cholesterol and 1% cholic acid diet supplemented with 3% L-arginine HCl in the drinking water (AC, n = 8). Eight weeks later, the blood samples were collected for biochemical studies, and the aortae were harvested for RT-PCR and immunohistochemical studies. RESULTS: The results showed that dietary L-arginine supplementation reduced expression of VCAM-1 in protein level and mRNA level. CONCLUSION: Inhibitory effect of dietary supplementation of L-arginine on VCAM-1 expression may be one of the mechanisms of its antiatherosclerosis.

Animals↗

Exploration on the characteristics of classification in Huangdi nei jing tai su.

Taishu, a book compiled by Yang Shangshan by imperial order, and completed in the reign of Gaozong of the Tang dynasty is the earliest complete commentary of Neijing now extant as well as early monograph interpreting Neijing by classification. By analysing the text of Taishi, Lingshu, Suwen and Jiayijing, this paper summarizes the characteristics of Yang Shangshan's classified compilation of the classical text. First, the whole text was classifiedly compiled from whole chapters or large paragraphs, with the text from Jiujuan (9 volume) arranged before those from Suwen. Second, deletion of duplicated text. For the duplicated text, those from Juijuan were mostly adopted, with those from Suwen discarded. Third, there are overlapping texts of eight strange channels, indicating the compilors' preference of the theory of channels. Fourth, systematization of Neijing theoretical system by dividing the chapters on the basis of different classes.

China↗

[Studies on the expression of complement regulatory proteins in three kinds of stem cell defect anemias and its clinical implications].

OBJECTIVE: To investigate the expression of membrane associated complement regulatory proteins (CRP)--CD55 and CD59 on the peripheral blood cells in patients with paroxysmal nocturnal hemoglobinuria (PNH), aplastic anemia(AA) and myelodysplastic syndrome (MDS) and its clinical implications. METHODS: Expression of CD55 and CD59 on neutrophils, lymphocytes and erythrocytes was analyzed with flow cytometry, using FITC and PE labeled anti-CD55 and CD59 monoclonal antibodies. RESULTS: CD55 and CD59 expression on neutrophils was significantly decreased in 21 PNH patients (including 2 cases of AA-PNH syndrome). CD59- cells in neutrophils were constantly in excess of 10% in all of the PNH patients. Reduction in CD59 expression on erythrocytes was related to the severity of the disease. CD55- neutrophils were also significantly increased in PNH patients but with a greater variation. Expressions of CD55 and CD59 on neutrophils were remarkably decreased in 31 AA patients but to a less extent as compared to PNH. No significant difference in the expressions of CD55 and CD59 was found in all the 21 MDS patients. CONCLUSION: Expression of CRP is reduced in PNH and its related disorder-AA but remains unchanged in MDS. Flow cytometric analysis of complement regulatory proteins is of value in diagnosis and differential diagnosis of PNH, AA and MDS. In terms of diagnostic sensitivity and specificity, CD59 is superior to CD55, and neutrophil is superior to lymphocyte and erythrocyte.

Adolescent↗

Partial left ventriculectomy for the treatment of end-stage dilated cardiomyopathy.

OBJECTIVE: To report our initial experience of the first 5 cases of partial left ventriculectomy (PLV or Batista operation), a new surgical therapy for treatment of end-stage dilated cardiomyopathy in China. METHODS: From April to August 1998, 5 patients with idiopathic dilated cardiomyopathy received PLV at Anzhen Hospital. The mean age of the patients was 48.4 years (range: 42 to 53 years). Three patients were in New York Heart Association (NYHA) class III and 2 in class IV. All patients had mitral valve insufficiency (3 moderate and 2 severe) and 1 had severe tricuspid valve insufficiency in addition preoperatively. Cardiopulmonary bypass and cardiac arrest with cold blood cardioplegia were used in all patients. The average weight of the resected left ventricle muscle was 46.3 g. All patients underwent mitral annuloplasty and 1 plus tricuspid annuloplasty (De Vega). RESULTS: Echocardiography demonstrated a significant decrease in left ventricular diastolic diameter (8.4 +/- 1.1 cm to 5.4 +/- 0.4 cm, P < 0.01) and an increase in ejection fraction (17.78% +/- 6.26% to 34.82% +/- 3.18%, P < 0.025). One patient died of heart failure on the 6th postoperative day. The mean follow-up period of the 4 discharged patients were 4 months (from 3 to 6 months). One were in NYHA class I and 3 in class II; all had a normal life. CONCLUSION: Batista operation is a new and valuable alternative of the surgical treatment for end-stage dilated cardiomyopathy and the long-term results need further studies.

Adult↗

Effect of immunization in mice with recombinant DNA encoding the hepatitis C virus structural protein.

OBJECTIVE: To explore the possibility and the efficacy of immune responses in mice inoculated with recombinant plasmid pCD-HCV1 and to lay a foundation for HCV nucleic acid vaccine development in the future. METHODS: The gene fragment coding C and E regions of HCV-II (type I b) was inserted into pCD-SR alpha 1 expression vector and formed pCD-HCV1 and then was injected into quadriceps muscles of Balb/c mouse. Serum anti-HCV level of mice was tested by ELISA (A value). Spleen cells proliferation responses to HCV antigens were detected by 3H-TdR incorporation (cpm). RESULTS: Balb/c mice immunized with recombinant plasmid pCD-HCV1 three or four times can generate specific antibody responses to HCV antigens and the antibody levels gradually ascend to the plateaus and did not have the trend of descending in 18 weeks detected. The serum antibodies in mice immunized by recombinant plasmid pCD-HCV1 were 100 percent positive when the serum were diluted 40 times and the positive rate of antibody still were 16.6 percent positive when the serum were diluted 320 times. Balb/c mice immunized with recombinant plasmid pCD-HCV1 (100 micrograms, 50 micrograms 10 micrograms/mouse three times respectively) can elicit antibody responses to HCV antigens and the antibody levels of three groups were 0.70 +/- 0.07, 0.33 +/- 0.04 and 0.11 +/- 0.09 respectively. Spleen cells of Blab/c mice injected with pCD-HCV1 three times were induced to produce proliferation responses to HCVc + e specific antigens. CONCLUSIONS: These results demonstrated that constructs expressioning HCV core and envelope proteins can generate anti-HCVc + e specific antibody responses and lymphoproliferation responses in mice, which suggested it to be possible to elicit immune responses to viral epitopes from HCV via DNA immunization with HCV-DNA recombinant and to warrant further investigation as a potential vaccine against HCV infections.

Animals↗

[Experimental study of immunization of mice with hepatitis C virus genetic vaccine constructs].

OBJECTIVE: To inquire into the immune responses to expression protein in mice immunized with genetic vaccine of hepatitis C virus (HCV) and lay a foundation for HCV genetic vaccine development in future. METHODS: The gene fragments coding C and most E regions of HCV-II type were inserted into pCD-SRalpha(1) of eukaryotic expression vector and formed genetic vaccine constructs of pCD-HCV(1) and then was injected into the quadriceps muscles of Balb/c mice. The serum anti-HCV level of mice was tested by ELISA and peripheral blood mononuclear cell (PBMC) proliferative responses to HCV antigens were detected by (3)H-TdR incorporation method (cpm). RESULTS: The serum antibody level reached to 0.71 +/- 0.08 - 0.77 +/- 0.06 (A value, the same below) after genetic vaccine pCD-HCV(1) (100 microg/mouse) were inoculated into the mice (n = 12) three or four times while blank vector pCD-SRalpha(1) could not induce the mice (n = 8) to generate antibody response in same way. After the antibody levels in mice (n = 8) immunized by pCD-HCV(1) had ascended to peak value (0.71), there was no trend of descending during the following 18 weeks of detection (0.68 +/- 0.06 - 0.75 +/- 0.07). Specific fragment of HCV cDNA identified by polymerase chain reaction (PCR) from DNA extracted from the muscles of the mice after pCD-HCV(1) had been inoculated three months. PBMC proliferative responses to HCV synthetic peptides CP(9) and gene recombinant antigens C, E(1) in the mice immunized with pCD-HCV(1) were detected and its stimulation indexes (SI) were 4.07 +/- 1.58, 3.88 +/- 0.70 and 3.69 +/- 1.13 respectively and there was a significant difference (P < 0.001) as compared with that of PBMC in mice immunized with pCD-SRalpha(1). CONCLUSION: These investigations demonstrated that genetic vaccine constructs made of HCV structural region can induce Balb/c mice to generate antibody and PBMC proliferative responses to HCV antigens via DNA immunization.

Animals↗

[Diagnosis and differential diagnosis of primary carcinoma of female peritoneum].

OBJECTIVE: Histogenesis and morphological features of 6 primary carcinomas of female peritoneum were studied. METHODS: H&E staining, histochemical stainings and immunohistochemical stainings were used. RESULTS: Among 6 primary carcinomas there were 4 cases of serous papillary carcinomas, 1 case of endometrioid carcinoma and 1 case of transitional cell carcinoma. CONCLUSION: Primary carcinomas of the female peritoneum were histologically identical to that of the similar epithelial carcinomas arising from the ovaries. The diagnosis was made only when the ovaries are not involved and without no any evidence of similar epithelial carcinoma obtained in the ovaries, uterus or urinary organs. These tumors are considered arising from the secondary Mullerian system. D-PAS and CEA staining are helpful as the accessory criteria for the differential diagnosis between primary carcinoma of the peritoneum and malignant mesothelioma.

Adult↗

[Study on the pharmacokinetics of the liver targeted mitoxantrone polylactic acid extended-release nanoparticles in rabbits].

HPLC was used to analyse the drug concentrations in blood. The 3p87 (practical pharmacokinetic program-version) was used to calculate the parameters of DHAQ-PLA-NP lyophilization injection and DHAQ injection through i.v. administration in rabbit blood. The concentration-time curves of the two kinds of preparations were in keeping with the three-compartment model. The drug concentrations were calculated according to the selecting pharmaceutical model and parameters. The calculated drug concentrations agreed well with the observed. The lyophilization injection sustained the eliminating process in vivo.

Animals↗

[Detecting microorganisms in soil by PCR and molecular hybridization].

PCR and molecular hybridization provide new methods to detect microorganisms in environment. A simple, sensitive protocol was developed to detect Bacillus thuringiensis HD-1 in soil by PCR and Southern Blotting in this study. Methods of extracting DNA from soil and purification were compared. By a modified total DNA extraction from soil and purification, followed by PCR and Southern Blotting, strain HD-1 released into soil can be detected with a sensitivity of 2.2 x 10(2) cells/g soil. By using other specific primers, this detection protocol can be widely used in the research of ecology and risk assessment of genetically engineered microorganisms released into environment.

Bacillus thuringiensis↗

[Protection of PNH red blood cells from lysis by transferring GPI-anchored protein vesicles of normal human RBCs in vitro].

OBJECTIVE: To observe the transfer of GPI-anchored protein CD59 from vesicles of normal RBCs to paroxysmal nocturnal hemoglobinuria(PNH) RBCs can correct the susceptibility to complement attack in vitro. METHODS: Vesicles released from normal RBCs under ATP depletion or storage, are rich in CD59. PNH CD59- RBCs were separated by elution from immunoaffinity column bound with monoclonal antibody CD59, and then incubated with normal RBCs vesicles. The content of CD59 in vesicles and RBCs was detected by Western blot and flowcytometric analysis respectively and hemolysis of PNH CD59- RBCs was detected by cobra venom factor hemolysis test. RESULTS: The fluorescence intensity of PNH CD59- RBCs were increased from (1.68 +/- 0.57)% to (58.42 +/- 8.25)% and the hemolysis was significantly decreased from (27.13 +/- 9.69)% to (19.49 +/- 7.61)% after incubation with vesicles prepared from normal donors (P < 0.05), while normal RBCs had no obvious change before and after the same treatment. (P > 0.05). CONCLUSIONS: It seems that CD59 protein molecules could be transfered from normal RBCs vesicles to PNH CD59- RBCs and retaining the complement regulatory function. CD59- RBCs could be rendered less liable to hemolyze during complement attack.

CD59 Antigens↗

[Olfactory evoked potentials produced by electrical stimulation of the olfactory mucosa].

OBJECTIVE: To develop an objective olfactometric method. METHODS: Electrically evoked olfactory potentials were recorded in 20 rabbits with 0.2-4.0 mA electrical stimulations. The stimulating electrodes were placed on the olfactory and respiratory regions of the nasal mucosa. Recording electrode was placed on the scalp near the olfactory bulb. RESULTS: Electrically evoked olfactory potentials composed of triphasic negative-positive-negative peaks, named N1, P1, N2 respectively, were detected on the olfactory region. The latencies of N1, P1, N2 were 16.27 ms, 25.36 ms, 49.75 ms respectively in cribriform plate. No electrically evoked potentials were detected on the respiratory mucosa, nor did on the olfactory mucosa after olfactory neurectomy. CONCLUSION: Steady and clear electrically evoked olfactory potentials which originated from olfactory neurosystem were detected on olfactory mucosa in rabbits.

Animals↗

DNA binding activity of the aryl hydrocarbon receptor is sensitive to redox changes in intact cells.

The potential involvement of vicinal dithiols in the transformation of the aryl hydrocarbon (Ah) receptor from its ligand binding to DNA binding form in Hepa-1 cells was explored through the use of diamide and phenylarsine oxide (PAO), which have been shown to specifically form a stable ring complex with vicinal sulfhydryl groups in selected proteins. Pretreatment with diamide and PAO rapidly prevented the inducer-dependent formation of the Ah receptor/xenobiotic response element complex detected by electrophoretic mobility shift assays and suppressed Ah receptor-mediated transcription. Diamide and PAO also inhibited DNA binding activity of the nuclear Ah receptor subsequent to its translocation to the nucleus but to a lesser extent than that observed with pretreatment conditions. The Ah receptor exhibited much higher sensitivity to cellular redox changes than Sp1, a transcription factor previously shown to be very sensitive to redox regulation. Diamide added to nuclear extracts inhibited Ah receptor DNA binding more than when it was added in intact cells. In contrast, Ah receptor DNA binding activity was more sensitive to PAO when it was added to intact cells than when it was added to nuclear extracts. Finally, dithiol 2,3-dimercaptopropanol was over 100 times more effective than monothiol 2-mercaptoethanol in reversing the PAO-dependent inhibition of Ah receptor DNA binding activity. This suggests that vicinal sulfhydryl residues may be involved in DNA binding of the Ah receptor.

Animals↗

Design of organic molecules with large two-photon absorption cross sections.

A strategy for the design of molecules with large two-photon absorption cross sections, delta, was developed, on the basis of the concept that symmetric charge transfer, from the ends of a conjugated system to the middle, or vice versa, upon excitation is correlated to enhanced values of delta. Synthesized bis(styryl)benzene derivatives with donor-pi-donor, donor-acceptor-donor, and acceptor-donor-acceptor structural motifs exhibit exceptionally large values of delta, up to about 400 times that of trans-stilbene. Quantum chemical calculations performed on these molecules indicate that substantial symmetric charge redistribution occurs upon excitation and provide delta values in good agreement with experimental values. The combination of large delta and high fluorescence quantum yield or triplet yield exhibited by molecules developed here offers potential for unprecedented brightness in two-photon fluorescent imaging or enhanced photosensitivity in two-photon sensitization, respectively.

Aniline Compounds↗

Suppression of CYP1A1 transcription by H2O2 is mediated by xenobiotic-response element.

We have previously demonstrated that H2O2 downregulates CYP1A1 and CYP1A2 transcription in isolated rat hepatocytes (C. W. Barker, et al., 1994, J. Biol. Chem. 269, 3985-3990). In the present study, induction of chloramphenicol acetyltransferase (CAT) expression driven by 3.1 kb of rat CYP1A1 upstream regulatory sequences was suppressed by 56% in Hepa-1 cells treated with H2O2. Similarly, H2O2 inhibited CAT expression from vectors containing two copies of either xenobiotic-response element (XRE) 1 or XRE2. H2O2 did not inhibit basal CAT expression in cells that were not treated with the inducer beta-napthoflavone. Electrophoretic mobility shift assays demonstrated that the suppression of XRE-dependent transcription by H2O2 was not due to changes in nuclear aryl hydrocarbon (Ah) receptor DNA binding activity. Several types of experiments indicated that modulation of XRE enhancer strength by various means could modify H2O2-dependent suppression of CAT expression. Conditions that increased the transactivation potential of the Ah receptor (increase in XRE copy number or shortening of the distance between XREs and the minimal CYP1A1 promoter) attenuated the action of H2O2, while conditions that reduced XRE-mediated transactivation potential (decrease in XRE copy number, increase of the distance between the XRE and the promoter, or reduction of the number of bound Ah receptors by lowering the concentration of inducer) potentiated the inhibitory action of H2O2.

Animals↗

Tolerance in the replacement of the benzhydrylic O atom in 4-[2-(diphenylmethoxy)ethyl]-1-benzylpiperidine derivatives by an N atom: development of new-generation potent and selective N-analogue molecules for the dopamine transporter.

The replacement of the benzhydrylic oxygen atom of our previously developed dopamine transporter (DAT)-specific ligands 4-[2-(diphenylmethoxy)ethyl]-1-[(4-fluorophenyl)methyl]piperidine, 1a, and 4-[2-(bis(4-fluorophenyl)methoxy)ethyl]-1-benzylpiperidine, 1b, by a nitrogen atom resulted in the development of the N-analogues 4-[2-((diphenylmethyl)amino)ethyl]-1-[(4-fluorophenyl)methyl]pi peridi ne, 4a, and 4-[2-((bis(4-fluorophenyl)methyl)amino)ethyl]-1-benzylpiperidine, 4b. Biological evaluation of these compounds in rat striatal tissue and in HEK-293 cells expressing the cloned human transporters demonstrated high potency and selectivity of these compounds for the DAT. Thus the potency of the compound 4a for the DAT was 9.4 and 30 nM in rat striatal tissue and in the cloned transporter cells, and its binding selectivity for the DAT compared to the serotonin transporter (SERT) for these two systems was 62 and 195, respectively. The compound 4b similarly exhibited high potency and selectivity for the DAT. Thus, the replacement of the O atom in 1a,b by an N atom in 4a,b only had small effects on potency and selectivity. In comparison with GBR 12909 [1-[2-(bis(4-fluorophenyl)methoxy)ethyl]-4-(3-phenylpropyl)piperazine ] and WIN 35,428 [3beta-(p-fluorophenyl)-2beta-carbomethoxytropane] binding, these two novel N-analogues were slightly more potent and far more selective for the DAT. Thus, these novel N-analogues represent more polar new-generation piperidine congeners of GBR 12909. They might have useful potential application in developing a pharmacotherapy for cocaine dependence.

Animals↗