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Z Qiu

Publications and source records attributed to Z Qiu.

At least 37 records · Page 2Linked to original sources
PubMed2001

[The effects of high dose atropine on function of isolated diaphragmatic preparation of rats with omethoate poisoning].

OBJECTIVE: The study was designed to examine the influence of high dose atropine on respiratory muscle of rat isolated phrenic diaphragm. METHODS: Rats were divided into 2 groups: (1) a toxic group administered with 2LD(50) omethoate, SC. (2) a contrast group with 0.9% NS, SC. The function of isolated rat phrenic diaphragm was observed by MS-302 analysis instrument physiologically and pharmacologically. RESULTS: In both groups the function of isolated rat phrenic diaphragm was significantly reduced with atropine dose increasing gradually to 0.6 mg (P < 0.01). When the atropine dose amounted to 0.8 mg. The function of isolated rat phrenic diaphragm almost disappeared in the picture. When the atropine in the diaphragm was weed out, the function of isolated rat phrenic diaphragm recovered completely in 50 minutes. CONCLUSION: It is suggested that the cause of respiratory muscle paralysis may be related to high dose of atropine.

Animals↗
PubMed2000

c-Crk, a substrate of the insulin-like growth factor-1 receptor tyrosine kinase, functions as an early signal mediator in the adipocyte differentiation process.

Differentiation of 3T3-L1 preadipocytes into adipocytes is induced by a combination of inducers, including a glucocorticoid, an agent that elevates cellular cAMP, and a ligand of the insulin-like growth factor-1 receptor. Previous studies have implicated protein-tyrosine phosphatase (PTPase) HA2, a homologue of PTPase 1B, in the signaling cascade initiated by the differentiation inducers. Vanadate, a potent PTPase inhibitor, blocks adipocyte differentiation at an early stage in the program, but has no effect on the mitotic clonal expansion required for differentiation. Exposure of preadipocytes to vanadate along with the inducing agents led to the accumulation of pp35, a phosphotyrosyl protein that is a substrate for PTPase HA2. pp35 was purified to homogeneity and shown by amino acid sequence and mass analyses of tryptic peptides to be c-Crk, a known cytoplasmic target of the insulin-like growth factor-1 receptor tyrosine kinase. Transfection of 3T3-L1 preadipocytes with a c-Crk antisense RNA expression vector markedly reduced c-Crk levels and prevented differentiation into adipocytes. Studies with C3G, a protein that binds to the SH3 domain in c-Crk, showed that phosphorylation of c-Crk rendered the SH3 domain inaccessible to C3G. Taken together, these findings indicate that locking c-Crk in the phosphorylated state with vanadate prevents its participation in the signaling system that initiates adipocyte differentiation.

3T3 Cells↗
PubMed2000

Dynamic process of information transmission complexity in human brains.

Based on a complexity analysis of mutual information transmission of EEG developed by us [Xu J, Liu Z, Liu R, Yang Q (1997) Physica D 106: 363-374], dynamic processes of the complexity of mutual information transmission in human brains were studied. To diminish possible problems due to coarse graining preprocessing, some new measures of complexity were used. The results show that, just before and after generalized seizures, the complexities of almost all information transmission between different brain areas drop significantly; there is also a temporary decrease of complexity when subjects shift their attention. The above facts suggest that there is a transient decrease of information transmission complexity when brain state changes occur suddenly. Mental arithmetic tasks activate the left temporal lobe to exchange more information with other brain areas. The results hint that the methods used here might be an approach to observe quick processes in the living brain.

Adult↗
PubMed2000

Modified Aloe barbadensis polysaccharide with immunoregulatory activity.

Aloe barbadensis polysaccharide was partially digested with cellulase and further purified by dialysis, stepwise ethanol precipitation, and size exclusion chromatography. Crude modified Aloe polysaccharide (MAP) activated macrophage cells and stimulated fibroblast growth. Under the same conditions, native Aloe barbadensis gel had no effect on macrophage activation. MAP prevented ultraviolet B (UVB) irradiation-induced immune suppression as determined by contact hypersensitivity (CHS) response in C3H/HeN mice. This in vivo activity was correlated with the activity of MAP to inhibit UVB irradiation-induced tumor necrosis factor alpha (TNF-alpha) release from human epidermoid carcinoma cells (KB cells). MAP with an average molecular weight of 80,000 Dalton (Da) contained mannose, galactose, and glucose in a ratio of 40:1.4:1.0. MAP was likely a linear, highly acetylated molecule.

Adjuvants, Immunologic↗
PubMed2000

Mutations in the E1 hydrophobic domain of rubella virus impair virus infectivity but not virus assembly.

Rubella virus (RV) virions contain three structural proteins, a capsid protein that interacts with viral genomic RNA to form a nucleocapsid and two membrane glycoproteins, E2 and E1. We found that substitution of either an aspartic acid residue at Gly93 (G93D) or a glycine residue at Pro104 (P104G) in the internal hydrophobic domain of E1 affected virus infectivity but not virus assembly. Viruses carrying G93D and P104G mutations had impaired infectivity, reduced 1,000-fold and 10-fold, respectively. A revertant was isolated from the G93D mutant. Sequencing analysis showed that the substituted aspartic acid residue in G93D mutant had reverted to the original glycine residue, suggesting the involvement of Gly93 in membrane fusion during viral entry.

Amino Acid Substitution↗
PubMed2000

Anti-fecundity immunity in mice immunized with anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum.

OBJECTIVE: To observe the effects of anti-fecundity and anti-embryonation immunity of anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum on female adult worm. METHODS: The active immunization of C57BL/6 mice was conducted by means of three intraperitoneal injections of NP30. The control group was injected with SP2/0 ascites intraperitoneally. RESULTS: On the twenty-seventh day after challenge infection, the number of eggs in the liver tissue and in uterus of the group immunized with NP30 decreased by 30.91% and by 38.55%, respectively. On the thirty-ninth day after the challenge infection, the number of mature eggs in the liver tissue of the group immunized with NP30 decreased by 66.63% and the number of dead eggs increased by 60.66%. CONCLUSIONS: NP30, with which mice were actively immunized, possesses double effects of anti-fecundity and anti-embryonation immunity on female adult worm of Schistosoma japonicum, therefore it can be used as a promising candidate of anti-pathologic vaccine molecule against Schistosomiasis japonica.

Animals↗
PubMed2000

Vasoactive effects of adrenotensin and its interactions with adrenomedullin.

OBJECTIVE: To investigate the vasoactive effects of adrenotensin and the interactions between adrenotensin and adrenomedullin (ADM). METHODS: Isolated rat aortic tension, rat mean arterial pressure and 3H-TdR incorporation of rat vascular smooth muscle cells were measured. Isolated rat aortas were incubated in K-H solution containing adrenomedullin or adrenotensin. The released adrenotensin or adrenomedullin (in incubation medium) from rat aortas was measured by radioimmunoassay. RESULTS: 1 x 10(-8) and 1 x 10(-7) mol/L adrenotensin augmented rat aortic tension in a dose-dependent manner (P < 0.01). An intravenous bolus injection of adrenotensin (2.5 nmol/kg, i.v.) increased the mean arterial pressure by 28% in anesthetized rats (P < 0.01). 1 x 10(-7) mol/L adrenotensin increased 3H-TdR incorporation in cultured rat vascular smooth muscle cells by 55% (P < 0.01). Adrenomedullin inhibited these activities of adrenotensin to different extents. 1 x 10(-9), 1 x 10(-8) and 1 x 10(-7) mol/L adrenotensin decreased adrenomedullin release rates by 19%, 35% and 46%, respectively (P < 0.05 or P < 0.01) and 1 x 10(-8) mol/L adrenomedullin also inhibited adrenotensin release by 45% from rat aorta (P < 0.01). CONCLUSION: Adrenotensin is a novel peptide that elicits the activities of vasoconstriction, pressor effects and induces the proliferation of vascular smooth muscle cells. There is antagonism in vascular activities and reciprocal inhibition in the release between adrenotensin and adrenomedullin. These interactions are manifestations of intramolecular regulation of proadrenomedullin (Pro-ADM).

Adrenomedullin↗
PubMed2000

[The use of interposed colon for endothoracic anastomosis in esophageal surgery].

OBJECTIVE: To study the use of interposed colon for endothoracic anastomosis in esophageal surgery. METHODS: From May 1991 to December 1993, 28 cases were selected with carcinoma of the middle and/or lower segment of esophagus. After tumor resection, a segment of transverse colon with peduncle was anastomosed in its peristaltic direction to the two ends of the severed esophagus. The vagus nerve innervating esophagus and stomach was intact, the anastomical position of the esophagus-cardia hiatus and the stomach were preserved. RESULTS: No anastomosis leakage, reflux esophagitis or the symptoms caused by the endothoracic stomach occured in this group. The digestive function of the patients remained good. The 1-, 3-, 5-year survical rate was 96.6%, 92.8% and 71.4%, respectively. CONCLUSION: The interposed colon for endothoracic anastomosis is a comparatively ideal method for the reconstruction of esophagus following resection of cancer of mid and lower thind of the esophagus.

Adult↗
PubMed2000

[Bcl-2 antisense oligodeoxyribonucleotide increases apoptosis of lung carcinoma cells induced by cisplatin].

OBJECTIVE: To study the effect of antisense oligodeoxyribonucleotide (ODN) to apoptotic suppress gene bcl-2 on apoptosis of lung carcinoma cells induced by cisplatin. METHODS: The lung carcinoma cells expressing bcl-2 were chosen to participate in this experiment. Cultured cells were divided into 7 groups: ODN, nonsense, ODN + cisplatin, nonsense + cisplatin, cisplatin, lipofectin and control. Bcl-2 antisense or nonsense mixed with lipofectin was added into above corresponding cultured cells. After cultured for 6 hours, cisplatin was added into corresponding groups. The cells were cultured again for 16 hours. And then, the cells were smeared on slides. Apoptotic cells were labeled with TdT-mediated dUTP nick end labeling (TUNEL) method on cell smears. Apoptotic index (AI) was counted to show the percentage of apoptotic cancer cells. The immunocytochemistry was used to detect the expression of bcl-2 in carcinoma cells. RESULTS: The bcl-2 expression of cancer cell in ODN group was significantly decreased compared to the control and nonsense groups. The AI of ODN + cisplatin group was 16.4 +/- 1.7, cisplatin group 4.1 +/- 0.8, antisense group 5.9 +/- 0.2, nonsense group 3.3 +/- 0.7, nonsense + cisplatin 7.6 +/- 1.1, lipofectin 5.1 +/- 0.9, control group 3.6 +/- 0.6. The AI of antisense + cisplatin group was significantly higher than that of other groups. CONCLUSION: Antisense oligodeoxyribonucleotide to bcl-2 can inhibit significantly the expression of bcl-2 of lung cancer cells and increase apoptosis of cancer cells induced by cisplatin.

Antineoplastic Agents↗
PubMed2000

[Protective immunity induced by anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum in goats].

OBJECTIVE: To observe the protective immunity in goats induced by active immunization with anti-idiotypic monoclonal antibody NP30 of S. japonicum. METHODS: Goats were randomly divided into two groups. Experimental group had 12 goats. The NP30 was intramuscularly injected with a dosage of 1 000 microgram into the hind leg for three dosages continuously. The goats were challenged with cercariae eight weeks after the third immunization. Ten goats in the control group were intramuscularly injected with SP2/0 ascites and challenged with cercariae at the same time as the experimental group. All goats were killed at the twelfth week post-challenge. RESULTS: Active immunization with NP30 could produce a protection rate of 42.78% in goats. The number of eggs in liver and feces in the goats immunized with NP30 was decreased by 35.83% and 25%, respectively. The size and number of egg granulomas in the liver were lessened obviously and the weight of the goats increased significantly. CONCLUSION: Active immunization with NP30 could induce a good protection in goats against the infection with Schsitosoma cercariae.

Animals↗
PubMed1999

[Identification of mutations in the phenylalanine hydroxylase gene and exon 5 novel mutation Y166X(C-->G) in Yunnan].

OBJECTIVE: To identify the mutations of the phenylalanine hydroxylase gene in Yunnan so as to enhance the gene diagnosis of classical phenylketonuria (PKU) in that south-western province of China. METHODS: Exons 4,5,6,7,10,11 and 12 of the phenylalanine hydroxylase(PAH) were analyzed in 13/14 children affected with classical PKU from Yunnan by using PCR-single strand conformation polymorphism (PCR-SSCP),PCR-ASO dot blot hybridization,allele specific polymerase chain reaction(ASPCR) and PCR-direct sequencing. RESULTS: Five missense mutations, i.e. R243Q. (5/26), Y204C(3/28), G247V(1/26),R413P(2/28) and T418P(1/28);three nonsense mutations,i.e. Y166X(C-->G)(2/26),W326X(1/28) and Y356X(2/26);and one silent mutation(V399V)(2/26) were identified. The nonsense mutation Y166X(C-->G) should be a novel mutation as compared with the PAH Mutation Database. CONCLUSION: Five kinds of popular PAH gene mutation (R243Q,Y204C,V399V,Y356X and R413P) identified in the people of Yunnan are similar to those in the northern people, but such characteristic is different from that in the southern people. This finding will enhance the efficacy in gene diagnosis of PKU and will be of reference value for studies of population and regional difference in the pattern of PAH mutation distribution.

Child↗
PubMed1999

Alpha2-macroglobulin enhances the clearance of endogenous soluble beta-amyloid peptide via low-density lipoprotein receptor-related protein in cortical neurons.

Apolipoprotein E and alpha2-macroglobulin (alpha2M) are genetic risk factors for late-onset Alzheimer's disease, and both bind a cell surface receptor, the low-density lipoprotein receptor-related protein (LRP). To investigate the role of LRP on preventing the accumulation of beta-amyloid peptide (A beta), we examined the effects of alpha2M on the clearance of endogenous A beta. Studies were performed in primary Tg2576 transgenic mouse cortical neuronal cultures expressing human mutant amyloid precursor protein (APP) 695. This system allowed us to follow endogenous A beta using immunoblots to detect monomeric forms of the peptide. A beta and APP levels were measured in conditioned media. We found that activated alpha2M (alpha2M*) substantially decreased soluble A beta levels and had no effect on secreted or full-length APP levels. Native alpha2M, which is not a ligand for LRP, did not affect A beta levels. The receptor-associated protein, which inhibits interaction of all ligands with LRP in vitro, prevented alpha2M*-induced decreases of soluble A beta levels. These data suggest that alpha2M* affects soluble A beta clearance rather than A beta production. Further studies showed that similar A beta clearance via an LRP-mediated pathway was observed after treatment with another LRP ligand, lactoferrin. Taken together, these data demonstrate that alpha2M* enhances the clearance of soluble A beta via LRP in cortical neurons.

Amyloid beta-Peptides↗
PubMed1999

[Analyze T lymphocyte subsets of HIV/AIDS patients by flowcytometer].

OBJECTIVE: Using flowcytometer (FCM) to detect CD4+, CD8+ lymphocytes in peripheral blood, combine with clinical symptoms to evaluate the HIV/AIDS patients' immune state. METHODS: Anti-coagulated peripheral blood were obtained from 8 HIV-AIDS patients and 5 normal persons. After analyzing their total white cell counts, the whole blood was stained with two-color immunofluorescence using directly conjugated monoclonal antibody pairs, followed by lysis of red erythrocytes, fixation of lymphocytes, and analysis by flowcytometry. Multiplying the CD4 and CD8 percentages by the absolute number of lymphocytes obtained from the total white blood cell (WBC) count divide by the lymphocyte differential percentage, we got the CD4, CD8 counts. RESULTS: The HIV/AIDS patients' CD4 counts were lower than those of normal controls'. Especially, the AIDS patients' CD4 counts were all below 200 cells/mm3 and their clinical symptoms were serious. CONCLUSION: The HIV/AIDS patients' CD4 counts are highly correlated with their clinical symptoms. The result also shows that FCM is accurate, sensitive and reliable in CD4 count.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Chronic interleukin-6 alters NMDA receptor-mediated membrane responses and enhances neurotoxicity in developing CNS neurons.

Recent studies show that the cytokine interleukin-6 (IL-6) is expressed at elevated levels in the CNS in several disease states and contributes to the neuropathological process. The mechanisms through which IL-6 exerts its CNS effects are primarily unknown. We have investigated the pathophysiological effects of IL-6 on developing CNS neurons using a culture model system and a chronic treatment paradigm. Here, we show, using current- and voltage-clamp recordings, that chronic IL-6 treatment of developing cerebellar granule neurons increases the membrane and current response to NMDA and that these effects are the primary mechanism through which IL-6 produces an enhanced calcium signal to NMDA. We also show that calcium influx through voltage-sensitive calcium channels contributes to the enhanced calcium signal to NMDA in the IL-6-treated neurons in a developmentally regulated manner and that the membrane depolarization to NMDA is more sensitive to the NMDA receptor antagonist ifenprodil in the IL-6-treated neurons compared with control neurons at a late developmental stage, consistent with a larger proportion of NMDA receptors containing the NMDAR2B subunit in the IL-6-treated neurons. Additional studies show that IL-6 treatment reduces the number of granule neurons in culture and enhances neurotoxicity involving NMDA receptors. These results support a pathological role for IL-6 in the CNS and indicate that NMDA receptor-mediated functions are likely to play a critical role in neuropathological changes observed in CNS diseases associated with elevated CNS levels of IL-6.

Animals↗
PubMed1998

Neonatal alcohol exposure reduces NMDA induced Ca2+ signaling in developing cerebellar granule neurons.

Glutamatergic neurotransmission through NMDA receptors is critical for both neurogenesis and mature function of the central nervous system (CNS), and is thought to be one target for developmentally-induced damage by alcohol to brain function. In the current study we examined Ca2+ signaling linked to NMDA receptor activation as a potential site for alcohol's detrimental effects on the developing nervous system. We compared Ca2+ signals to NMDA in granule neurons cultured from cerebella of rat neonates exposed to alcohol (ethanol) during development with responses to NMDA recorded in separated control groups. Alcohol exposure was by the vapor chamber method on postnatal days 4-7. An intermittent exposure paradigm was used where the pups were exposed to alcohol vapor for 2. 5 h/day to produce peak BALs of approximately 320 mg%. Control pups were placed in an alcohol-free chamber for a similar time period or remained with their mother. After culture under alcohol-free conditions for up to 9 days, Ca2+ signaling in response to NMDA was measured using fura-2 Ca2+ imaging. Results show that the peak amplitude of the Ca2+ signal to NMDA was significantly smaller in cultured granule neurons obtained from alcohol-treated pups compared to granule neurons from control pups. In contrast, the Ca2+ signal to K+ depolarization was not depressed by the alcohol treatment. Resting Ca2+ levels were also altered by the alcohol treatment. These results show that intermittent alcohol exposure during development in vivo can induce long-term changes in CNS neurons that affect the Ca2+ signaling pathway linked to NMDA receptors and resting Ca2+ levels. Such changes could play an important role in the CNS dysfunction associated with alcohol exposure during CNS development.

Animals↗
PubMed1998

Effects of mutations in the rubella virus E1 glycoprotein on E1-E2 interaction and membrane fusion activity.

Rubella virus (RV) virions contain two glycosylated membrane proteins, E1 and E2, that exist as a heterodimer and form the viral spike complexes on the virion surface. Formation of an E1-E2 heterodimer is required for transport of E1 out of the endoplasmic reticulum lumen to the Golgi apparatus and plasma membrane. To investigate the nature of the E1-E2 interaction, we have introduced mutations in the internal hydrophobic region (residues 81 to 109) of E1. Substitution of serine at Cys82 (mutant C82S) or deletion of this hydrophobic domain (mutant dt) of E1 resulted in a disruption of the E1 conformation that ultimately affected E1-E2 heterodimer formation and cell surface expression of both E1 and E2. Substitution of either aspartic acid at Gly93 (G93D) or glycine at Pro104 (P104G) was found to impair neither E1-E2 heterodimer formation nor the transport of E1 and E2 to the cell surface. Fusion of RV-infected cells is induced by a brief treatment at a pH below 6. 0. To test whether this internal hydrophobic domain is involved in the membrane fusion activity of RV, transformed BHK cell lines expressing either wild-type or mutant spike proteins were exposed to an acidic pH and polykaryon formation was measured. No fusion activity was observed in the C82S, dt, and G93D mutants; however, the wild type and the P104G mutant exhibited fusogenic activities, with greater than 60% and 20 to 40% of the cells being fused, respectively, at pH 4.8. These results suggest that it is likely that the region of E1 between amino acids 81 and 109 is involved in the membrane fusion activity of RV and that it may be important for the interaction of that protein with E2 to form the E1-E2 heterodimer.

Amino Acid Sequence↗
PubMed1998

Functional comparison of the three isoforms of the Na+/Ca2+ exchanger (NCX1, NCX2, NCX3).

Three distinct mammalian Na+/Ca2+ exchangers have been cloned: NCX1, NCX2, and NCX3. We have undertaken a detailed functional comparison of these three exchangers. Each exchanger was stably expressed at high levels in the plasma membranes of BHK cells. Na+/Ca2+ exchange activity was assessed using three different complementary techniques: Na+ gradient-dependent 45Ca2+ uptake into intact cells, Na+ gradient-dependent 45Ca2+ uptake into membrane vesicles isolated from the transfected cells, and exchange currents measured using giant patches of excised cell membrane. Apparent affinities for the transported ions Na+ and Ca2+ were markedly similar for the three exchangers at both membrane surfaces. Likewise, generally similar responses to changes in pH, chymotrypsin treatment, and application of various inhibitors were obtained. Depletion of cellular ATP inhibited NCX1 and NCX2 but did not affect the activity of NCX3. Exchange activities of NCX1 and NCX3 were modestly increased by agents that activate protein kinases A and C. All exchangers were regulated by intracellular Ca2+. NCX1-induced exchange currents were especially large in excised patches and, like the native myocardial exchanger, were stimulated by ATP. Results may be influenced by our choice of expression system and specific splice variants, but, overall, the three exchangers appear to have very similar properties.

Animals↗