Biomedical subjects

R Zhou

Publications and source records attributed to R Zhou.

At least 37 records · Page 2Linked to original sources

PubMed2001

TGF-alpha induces a stationary, radial-glia like phenotype in cultured astrocytes.

Transgenic mice studies have suggested that transforming growth factor-alpha (TGF-alpha) influences the postnatal differentiation of astrocytes. To understand the role of TGF-alpha during astrocytic differentiation, it is important to determine how this factor affects astrocytes in the absence of other influences. We have thus examined in vitro under serum-free medium conditions the effect of TGF-alpha on the properties of astrocytes derived from the cerebral cortex of newborn rats. When TGF-alpha is added to serum-free medium, most astrocytes lose their polygonal shape and extend two long processes running in opposite directions. This bipolar morphology strikingly resembles that of radial glial cells. Intriguingly, serum inhibits this morphological transformation. TGF-alpha also triggers an increase in glial fibrillary acidic protein (GFAP) expression and a decrease in nestin expression. Another major effect of TGF-alpha is to practically abolish the motility of astrocytes. TGF-alpha, however, does not appear to influence the proliferation and apoptosis of astrocytes. These results suggest that polygonal astrocytes are derived primarily from radial glial cells, and that in vivo TGF-alpha may be instrumental in determining the shape and migratory potential of radial glial cells.

Aging↗

PubMed2001

[Influence of zafirlukast on pulmonary functions and quality of life in patients with asthma].

OBJECTIVES: To explore the influence of zafirlukast on pulmonary functions and quality of life (QOL) in patients with mild-to-moderate asthma at the stage of attack and at the stable stage. METHODS: Patients at the stage of attack were randomly divided into two groups: Group one is zafirlukast 20 mg twice daily plus inhaled the half quantity of glucocorticoid(budelade) of the Global Initiative for Asthma (GINA) standard quantity, long-effection aminophyllin 0.2 g twice daily and inhaled salbutamol when necessary; Group two: inhaled budelade of GINA standard quantity, long-effection aminophyllin 0.2 g twice daily and inhaled salbutamol when necessary). Patients' peak expiratory flow (PEF)/PEF predicted value % and delta PEFR% were determined at the second week and the forth week before and after the treatment. On the standard treatment, patients with the stable stage were added zafirlukast 20 mg twice a day. PEF values in the morning and evening and QOL were evaluated. RESULTS: After treating with zafirlukast, the PEF/PEF predicted value % and delta PEFR% in Group one were higher and lower than those of Group two respevtively. These changes were appeared in two days and were peaked in two weeks and the peak had been gone on for more than 4 weeks, but these were no significant difference between the Groups (P > 0.05); PEF values in the morning and evening in patients with the stable asthma increased 5.9% and 4.6% respectively and their QOL were improved in asthma symptoms, limitative activities, avoiding stimuli, and reacting on stimuli. CONCLUSION: Zafirlukast can improve pulmonary function, reduce the inhalation quantity of steroid in patients with mild-to-moderate asthma, and play an important role in treating and improving QOL in patients with the stable asthma.

Adolescent↗

PubMed2001

[Effects of noninvasive positive pressure ventilation on gas exchange and patients' transformation in chronic obstructive pulmonary disease and respiratory failure].

OBJECTIVE: This paper was to observe the effects of noninvasive positive pressure ventilation (NPPV) on gas exchange and patients' transformation and to evaluate their clinical value. METHODS: Patients were randomly treated by either NPPV, or conventional medicine. The arterial blood gas readings, heart rates (HR), and respiratory rates (HR) were obtained at admission after the treatment. It was necessary to intubate when the clinical deterioation was marked by PaCO2 > 70 mmHg, PaCO2 gradually increasing 5-10 mmHg, pH decreasing 0.05-0.1 or mental obstacle, or PaO2 < 45 mmHg. RESULTS: NPPV significantly decreased the PaCO2 level, HR, and RR, significantly increased the PaO2 level, and also decreased the opportunity of intubation. CONCLUSION: The results suggest that NPPV can improve the gas exchange and reduce the need of intubation in COPD patients with acute respiratory failure.

Aged↗

PubMed2001

Determination of etoposide in human plasma and leukemic cells by high-performance liquid chromatography with electrochemical detection.

This paper describes a high-performance liquid chromatographic method with electrochemical detection for the determination of etoposide levels in plasma, total and non-protein bound concentration, and in leukemic cells. The precision for between-runs (n=6) was 7.0, 4.9, and 9.5%, the accuracy was 3.7, 7.1 and 6.3%, and within-runs precision (n=6) was 3.9, 2.9 and 5.1% for total plasma, non-protein bound plasma fraction and leukemic cells, respectively. The correlation coefficients (R2) were 1.00 for all calibration curves. These assays have been applied to analyze samples from one patient with acute myelogenous leukemia during 24 h after i.v. infusion of etoposide (100 mg/m2).

Antineoplastic Agents, Phytogenic↗

PubMed2001

Synthesis and characterization of oxidized W(6)S(8)L(6) clusters.

Cationic [W(6)S(8)L(6)]PF(6) (L = PEt(3) (3), 4-tert-butylpyridine (4)) clusters were successfully synthesized and isolated for the first time by reacting the corresponding neutral W(6)S(8)L(6) (L = PEt(3) (1), 4-tert-butylpyridine (2)) clusters with [Cp(2)Fe]PF(6) as the oxidant. The products 3 and 4 were characterized by NMR spectroscopy, mass spectroscopy, and X-ray crystallography (only for 3) and shown to be the desired oxidized W(6)S(8) clusters with a metal electron count of 19. Magnetic property studies showed that they are paramagnetic compounds with S = (1)/(2). Their chemical properties and stability are also reported. Crystal data for 3.2 THF: space group, R3 (No. 148); a = 13.91170(10) A; c = 32.4106(2) A; Z = 3.

Journal Article↗

PubMed2001

Synthesis, characterization, and ligand exchange studies of W(6)S(8)L(6) cluster compounds.

Eleven organic Lewis bases were investigated as potential ligands (L) on W(6)S(8)L'(6) clusters by exploring ligand exchange reactions to form W(6)S(8)L(6) clusters. Six new homoleptic W(6)S(8)L(6) cluster complexes were prepared and characterized with L = tri-n-butylphosphine (P(n)Bu(3)), triphenylphosphine (PPh(3)), tert-butylisocyanide ((t)BuNC), morpholine, methylamine (MeNH(2)), and tert-butylamine ((t)BuNH(2)). While partial replacement of ligands occurred with diethylamine (Et(2)NH) and dibutylamine (Bu(2)NH), homoleptic clusters could not be prepared by these exchange reactions. When aniline, tribenzylamine, and tri-tert-butylphosphine were the potential ligands, no exchange was observed. From ligand exchange studies of these ligands and others previously studied, a thermodynamic series of binding free energies for ligands on W(6)S(8)L(6) clusters was established as the following: non-Lewis base solvents, aniline, P(t)()Bu(3), etc. << Et(2)NH, Bu(2)NH < (t)BuNH(2) < morpholine, piperidine < or = (n)BuNH(2), MeNH(2) < or = 4-tert-butylpyridine, pyridine < (t)BuNC < tricyclohexylphosphine (PCy(3)) < PPh(3), P(n)Bu(3) < or = triethylphosphine (PEt(3)). Structures of the new cluster complexes were determined by X-ray crystallography. The new compounds were also characterized by NMR spectroscopy and thermogravimetric analyses (TGA). The W-L bond orders and TGA data qualitatively agree with the thermodynamic series above.

Journal Article↗

PubMed2001

Mass transport characteristics and chromatographic behavior of preparative electrochromatography on hydroxyapatite.

Introducing an electric field into chromatography on hydroxyapatite (HAP) was attempted in order to enhance mass transfer and separation performance. A membrane spaced multicompartment electrolyzer was developed for electrochromatography on HAP. The high performance of liquid transport by electroosmotic flux was identified and described in terms of dynamic electroosmotic pressure. The application of the electric field resulted in an improved adsorption of bovine serum albumin as shown by the breakthrough curve as function of the electric field. An improved elution was also obtained in the presence of the electric field. The results show that electroosmosis is a powerful tool of liquid transport and dispersion in a packed bed of fine particles and has potential in the large-scale chromatography of biological molecules.

Adsorption↗

PubMed2001

Altered sensitivity of CD81-deficient mice to neurobehavioral effects of cocaine.

CD81, also known as target of the antiproliferative antibody, is known to be expressed in astrocytes and involved in cell adhesion and, recently, we demonstrated its induction exclusively in the accumbens following cocaine. In the present study, the sensitivity of CD81-deficient mice to behavioral effects of cocaine was evaluated. It was found that CD81-deficient mice exhibited altered sensitivity to cocaine as assessed in the place preference conditioning paradigm and locomotor activity. This deficit in place preference conditioning was not accompanied by a deficit in acquisition or retention of water maze behavior. In addition, CD81 knockout mice exhibited higher levels of nucleus accumbens dopamine as compared to their controls. These observations are discussed in the context of the role of CD81 in cocaine-mediated behaviors.

Animals↗

PubMed2001

In vivo detection of gene expression in liver by 31P nuclear magnetic resonance spectroscopy employing creatine kinase as a marker gene.

In vivo assessment of gene expression is desirable to obtain information on the extent and duration of transduction of tissue after gene delivery. We have developed an in vivo, potentially noninvasive, method for detecting virally mediated gene transfer to the liver. The method employs an adenoviral vector carrying the gene for the brain isozyme of murine creatine kinase (CK-B), an ATP-buffering enzyme expressed mainly in muscle and brain but absent from liver, kidney, and pancreas. Gene expression was monitored by (31)P magnetic resonance spectroscopy (MRS) using the product of the CK enzymatic reaction, phosphocreatine, as an indicator of transfection. The vector was administered into nude mice by tail vein injection, and exogenous creatine was administered in the drinking water and by i.p. injection of 2% creatine solution before (31)P MRS examination, which was performed on surgically exposed livers. A phosphocreatine resonance was detected in livers of mice injected with the vector and was absent from livers of control animals. CK expression was confirmed in the injected animals by Western blot analysis, enzymatic assays, and immunofluorescence measurements. We conclude that the syngeneic enzyme CK can be used as a marker gene for in vivo monitoring of gene expression after virally mediated gene transfer to the liver.

Adenoviridae↗

PubMed2001

Comparison of arrhythmias among different left ventricular geometric patterns in essential hypertension.

The differences of arrhythmias among distinct left ventricular geometric patterns in the patients with essential hypertension were studied. 179 patients with essential hypertension received 24 h dynamic ECG recording, ambulatory blood pressure monitoring, echocardiography examination, etc. According to the examinations, left ventricular geometric patterns and arrhythmias were identified. The comparison of morbidity of arrhythmias between the left ventricular remodeling group and the normal geometric pattern group was performed. The multiple stepwise regression analysis was carried out to identify the independent determinants of arrhythmias. After these predictors were controlled or adjusted, the severity of arrhythmias among different left ventricular geometric patterns was compared. It was found that the morbidity of atrial arrhythmia, ventricular arrhythmia and complex ventricular arrhythmias in the left ventricular remodeling group was significantly higher than in the normal geometric pattern group respectively. There were many independent factors influencing on arrhythmias in essential hypertension. Of all these factors, some indices of left ventricular anatomic structure, grade of hypertension, left atrial inner dimension, E/A, diastolic blood pressure load value at night and day average heart rate and so on were very important. After the above-mentioned factors were adjusted, the differences of the orders of arrhythmias between partial geometric patterns were reserved, which resulted from the differences of the geometric patterns. Many factors contributed to arrhythmias of essential hypertension, such as grade of hypertension, LVMI, LA, PWT and so on. The severity of arrhythmias was different in different left ventricular geometric patterns.

Aged↗

PubMed2001

Thymic epithelial tumors can develop along two different pathogenetic pathways.

To investigate genetic abnormalities associated with the development of thymic epithelial tumors, we performed microsatellite analysis of 26 thymomas belonging to three different World Health Organization types (A, B3, and C) using 48 repeats. The most frequent aberration seen was loss of heterozygosity (LOH) in the region 6q23.3-25.3 detected in 11 tumors (45.8% of informative cases). Further consistent LOHs were detected in regions 3p22-24.2, 3p14.2 (FHIT gene locus), 5q21 (APC), 6p21, 6q21-22.1, 7p21-22, 8q11.21-23, 13q14 (RB), and 17p13.1 (p53). Microsatellite instability was extremely rare, occurring in one type B3 thymoma only, although, at 12.5% of the analyzed loci. Comparing the allelotypes of the analyzed thymomas, we were able to identify two pathogenetic pathways these tumors develop along, characterized by the 6q23.3-25.3 and 5q21 LOHs, respectively. The APC aberration on 5q21 showed significant associations with LOH in the 3p22-24.2, 13q14, and 17p13.1 regions. Interestingly, type A thymomas presented with consistent LOH in the region 6q23.3-25.5 only, they did not reveal any aberrations in the APC, RB, and p53 gene loci or regions 3p22-24.2 and 8q11.21-23. The absence of these aberrations might be the reason for the well-known benign behavior of type A thymomas as compared to types B3 and C tumors.

Adult↗

PubMed2001

In vitro topo II--DNA complex accumulation and cytotoxicity of etoposide in leukaemic cells from patients with acute myelogenous and chronic lymphocytic leukaemia.

Topoisomerase II (topo II) is the target enzyme of etoposide, and DNA--topo II complex accumulation is considered crucial for the cytotoxic effect. We used a SDS--KCl precipitation assay to determine the complex accumulation induced by etoposide in leukaemic cells isolated from 58 patients, 31 with acute myelogenous leukaemia (AML), and 27 with chronic lymphocytic leukaemia (CLL). To investigate whether the sensitivity towards etoposide was dependent on the complex accumulation in the cells, we investigated the drug-induced DNA damage using a DNA unwinding assay and the in vitro cytotoxicity of etoposide using the MTT assay. AML cells had higher complex accumulation (P=0.006) and more DNA damage (P=0.029) compared with CLL cells. The data support a relationship between etoposide-induced complex accumulation and DNA damage in leukaemic cells from AML and CLL patients. However, the induced DNA damage did not translate to in vitro cytotoxicity, suggesting that other factors, such as DNA repair and apoptosis functions, also play important roles to determine the etoposide sensitivity.

Adult↗

PubMed2001

Enhancement of hyperglycemia-induced acidification of human melanoma xenografts with inhibitors of respiration and ion transport.

RATIONALE AND OBJECTIVES: The authors performed this study to evaluate the selective acidification of a human melanoma xenograft in mice with severe combined immunodeficiency with the induction of hyperglycemia (mean blood glucose level +/- standard error of the mean, 26 mmol/L +/- 1) and the intraperitoneal administration of metaiodobenzylguanidine (MIBG, 30 mg/kg), alpha-cyano-4-hydroxycinnamate (CNCn, 300 mg/kg), lonidamine (100 mg/kg), cariporide (HOE642, 160 mg/kg), or 4.4'-diisothiocyanatostilbene-2, 2'-disulfonic acid (DIDS, 50 mg/kg). MATERIALS AND METHODS: The intra- and extracellular pH levels of tumor were estimated from the chemical shifts of inorganic phosphate and 3-aminopropylphosphonate, respectively, with phosphorus-31 nuclear magnetic resonance (MR) spectroscopy. The relative level of steady-state lactate was monitored with hydrogen-1 MR spectroscopy. RESULTS: In small tumors (< or = 8.0 mm), hyperglycemia decreased the intra- and extracellular pH levels by less than 0.2. The combination of hyperglycemia and MIBG decreased the intra- and extracellular pH levels by approximately 0.4 and 0.6, respectively, and lowered the beta-nucleoside triphosphate (NTP)/inorganic phosphate (Pi) ratio of tumor and liver by about 60% and 25%, respectively. The combination of hyperglycemia, MIBG, and CNCn produced a transient decrease in the intracellular pH of about 0.6. The combination of hyperglycemia and lonidamine produced a sustained (>3 hours) 0.8-unit decrease in intracellular pH and an 83% and 100% decrease in PCr/P1 and beta-NTP/P1 ratios, respectively. The combination of hyperglycemia. MIBG, cariporide, and DIDS produced a gradual decrease in intra- and extracellular pH by 1.1 and 1.0, respectively. The relative level of steady-state lactate concentration in tumors increased 10% with hyperglycemia alone, about 20% with MIBG plus hyperglycemia, and increased more than twofold when hyperglycemia was combined with MIBG and CNCn administration. CONCLUSION: These preliminary data suggest that hyperglycemia and combinations of respiratory and ion transport inhibitors can be used to selectively acidify tumors and, thereby, sensitize them to hyperthermnia or other pH-sensitive therapeutic modalities.

3-Iodobenzylguanidine↗

PubMed2001

Differential effects of overexpression of two forms of ephrin-A5 on neonatal rat cardiomyocytes.

Eph receptors constitute the largest family of receptor tyrosine kinases. Multiple transcripts of ephrin-A5, the cognate ligand of the EphA3 receptor, were found in neonatal rat cardiomyocytes. Two cDNA clones encoding the full-length ephrin-A5 (ephrin-A5 alpha) and a 27-amino acid deletion form (ephrin-A5 beta) were isolated. To examine the role of ephrin-A5 in cardiomyocytes, the cDNAs were inserted into adenoviral vectors, termed Ad.ephrin-A5 alpha and Ad.ephrin-A5 beta, respectively, and overexpressed in cardiomyocytes. The effect of ephrin-A5 on cardiomyocyte gene expression was investigated using a cDNA expression array and Western blot analysis. The results showed that both ephrin-A5 alpha and ephrin-A5 beta downregulated cyclin D2, cyclin-dependent kinase-4 proteins, and their cognate receptor EphA3, which were associated with reduced bromodeoxyuridine incorporation in cardiomyocytes. Whereas ephrin-A5 alpha and ephrin-A5 beta also induced differential gene expression, only ephrin-A5 beta significantly upregulated the transcription of brain natriuretic peptide and downregulated ras-related protein RAB2, protein kinase C inhibitor protein-1, clusterin, and insulin-like growth factor-binding protein. The results suggest that the two forms of ephrin-A5 share similar function while differ in regulating different sets of genes in cardiomyocytes.

Adenoviridae↗

PubMed2001

[Study on expression of caspase-3 and bcl-2 proteins and their relations with cell apoptosis and proliferation in non-Hodgkin's lymphoma].

OBJECTIVE: To explore the possible roles of caspase-3 and bcl-2 proteins in the development and progression of non-Hodgkin's lymphoma (NHL) and their relationship. METHODS: TdT-mediated dUTP nick end labeling (TUNEL) and immunohistochemistry were used to study cell apoptosis and expression of proliferating cell nuclear antigen (PCNA), caspase-3 and bcl-2 in 119 NHL cases. RESULTS: The caspase-3 and bcl-2 positive rates were 86.6% (103/119) and 53.8% (64/119) respectively. Contrasting expression of these two proteins were found in reactive and malignant lymphoid tissues: In reactive lymphoid follicles, caspases-3 exhibited strong immunoactivity in cells located in germinal centers but not in mantle zone lymphocytes, whereas bcl-2 exhibited strong immunoactivity in mantle zone lymphocytes but not in cells located in germinal centers, and in neoplastic follicles, caspase-3 was negatively or weakly expressed, whereas bcl-2 was often positively expressed. In B cell lymphomas, the high grade group had a higher caspase-3 immunointensity and a lower bcl-2 immunointensity than the low grade group (P < 0.01). Apoptotic index correlated positively with expression of caspase-3 (r = 0.512, P < 0.01) and inversely with expression of bcl-2 (r = -0.436, P < 0.01). In addition, apoptotic index and proliferative index were positively related (r = 0.710, P < 0.01). CONCLUSIONS: caspase-3 may participate in the regulation mechanism of lymphoma cell apoptosis. The contrasting expression of caspase-3 and bcl-2 is often seen in reactive and malignant lymphoid tissues, and it may indicate a close relationship between these two proteins in the regulation of lymphocyte proliferation kinetics.

Adolescent↗

PubMed2001

[Clindamycin soluble suppository-production and its efficacy in treating bacterial vaginosis].

OBJECTIVE: To make the soluble suppository of clindamycin which is an effective drug for treatment of Bacterial vaginosis and to treat patients in clinical trials. METHODS: Outpatients who had vaginal infections from Sept. 1998 to Jan. 1999 were investigated. The diagnoses of bacterial vaginosis were made according to Amsel's criteria and 80 patients were included in this study. They were divided into two groups to be treated respectively by metronidanole suppository and clindamycin suppository which were made by our hospital pharmacy. RESULTS: The cure rate of metronidanole was 87.5% and that of clindamycin 90.3%; No significant difference was noted between the two groups(P > 0.05). The new clindamycin suppository was not irritant and it was easy to dissolve in vagina. There was no discontinued treatment because of side-effect. CONCLUSION: The clindamycin suppository does not irritate the mucosa of vagina, it is an efficacious remedy for bacterial vaginosis.

Administration, Intravaginal↗

PubMed2001

[The influence of IL-2 on the immunologic function of the NPC patients treated with radiotherapy and chemotherapy].

OBJECTIVE: To investigate the combining therapy which not only have cured effect but also can uphold and improve the NPC patient's immunity function after radiotherapy and chemotherapy. METHOD: 90 cases randomly divided into 3 groups 1. Local group (local injected with IL-2 + radiotherapy + chemotherapy); 2. General group (ivdrip with IL-2 + radiotherapy + chemotherapy); 3. Convention group (radiotherapy + chemotherapy). Checked and observed the immunity function around the immunotherapy and after the radiotherapy and chemotherapy. RESULT: Cellular immunity of 3 groups are lower and humoral immunity are hypetuntion than normal person. After treated with IL-2 the cellular immunity improves but there's no great change of the humoral immunity. The immune status of the immune groups have not obvious change than before radiotherapy, at the same time, the cellular immunity of the convention group cut down and the humoral immunity doesn't change obviously. CONCLUSION: 1. It has some effect to uphold and improve the NPC patient's immunity function to treat with small dosage of IL-2 before radiotherapy and chemotherapy, general treatment is better than local injection; 2. The three therapies have not great influence on the patient's humoral immunity.

Adult↗

PubMed2001

[Primary restoration for congenital malformation of external and middle ear].

OBJECTIVE: To promote the hearing, improve the appearance, shorten the therapeutic course in congenital malformation of external and middle ear, the program of primary restoration has been designed. METHOD: Under general or local anaesthesia a Z-shaped incision is made in skin. After turn up the flap A (defective ear) and flap B(retroauricular skin), a periosteal flap C with pedicle in front is made and elevated from mastoid. Then made frameworklize on mastoid and perform tympanoplasty. Once the myringograft is put properly the flap C is turn into the mastoidal cavity to serve as the lining of anterior wall. Flap A is sutured with the edge of retroauricular incision to serve as the lower part of new auricle. Then use the flap B to wrap a siliceous frame to make the upper part of new auricle. Finally, the naked walls of mastoidal cavity are lined with free skin graft and the cavity is packed with vaseline gauze for two weeks. RESULT: Two cases of congenital malformation of external and middle ear were treated with the procedure mentioned above and were followed up for one and 3 years respectively. Both effects of shape and hearing were good. CONCLUSION: The primary restoration for congenital malformation of external and middle ear designed by the authors is an excellent method worthy to be recommended.

Adolescent↗