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C Qian

Publications and source records attributed to C Qian.

At least 109 records · Page 6Linked to original sources
PubMed1993

Molecular cloning of a mouse myosin I expressed in brain.

We have isolated two cDNAs that encode putative myosin I heavy chains by polymerase chain reaction amplification of brain cDNA with degenerate oligodeoxynucleotide primers representing myosin I-specific conserved amino acid sequences. We report the complete deduced amino acid sequence of one of these cDNAs. The sequences is most similar to those of the avian and bovine brush border myosin Is, with five putative calmodulin-binding repeats at the head-tail junction. Northern analysis demonstrates that this myosin heavy chain, unlike the brush border myosins, is expressed in many tissues.

Amino Acid Sequence↗
PubMed1993

Abnormal expression of anion exchanger genes in primary biliary cirrhosis.

BACKGROUND: Chloride-bicarbonate anion exchangers (AE) are thought to be essential to the generation of ion fluxes into biliary, salivary, pancreatic, and other secretions. In primary biliary cirrhosis (PBC), chronic cholestasis is frequently associated with pluriglandular exocrine failure. The present study examined the expression of AE genes in PBC at the messenger RNA (mRNA) level. METHODS: Two AE messages, i.e., AE1 and AE2 mRNAs, were analyzed by a polymerase chain reaction-based procedure in liver specimens and peripheral mononuclear cells of patients with PBC and control subjects (with normal livers or with miscellaneous liver diseases). RESULTS: AE1 mRNA was detected in only a few liver biopsy specimens of patients with PBC and control subjects, whereas AE2 mRNA was found in all liver specimens tested. In lymphoid cells, however, both transcripts were consistently detected. AE2 mRNA levels in liver as well as in lymphoid cells were significantly lower in PBC patients than in controls. In contrast to AE2 mRNA, AE1 mRNA levels were increased in lymphoid cells from patients with PBC. Interestingly, the levels of liver AE2 mRNA in a few PBC patients treated with ursodeoxycholic acid were within the range of the controls. CONCLUSIONS: The expression of AE genes is altered in patients with PBC. It is suggested that this disturbance may have a role in the cholestasis, exocrine failure, and immunodysfunction of PBC.

Adult↗
PubMed1993

Vaccination of bovines against Schistosomiasis japonica with cryopreserved-irradiated and freeze-thaw schistosomula.

Four laboratory tests and one field trial with cryopreserved irradiated (CI) schistosomula vaccine and a freeze-thaw (F/T) vaccine against bovine Schistosomiasis japonica were carried out in 1979 and 1980 with the following results: (1) Single intradermal vaccination in buffalo calves each with 10,000 20 krad CI Schistosomula plus 1 ml BCG gave 62% worm reduction (P < 0.05). Using the same protocol 55% worm reduction (P < 0.01) was obtained in cattle. (2) Buffalo calves immunized twice, at a 1.5 month interval, with 10,000 and 20,000 CI schistosomula, respectively, resulted in a worm reduction 65%. (3) In a preliminary field trial with 10,000 CI schistosomula plus 1 ml BCG resulted in a worm reduction of 53% in buffalo calves. (4) Intradermal vaccination of 30,000 F/T schistosomula with 1 ml BCG was also tried in cattle and revealed a worm reduction of 57% but increasing the number of vaccinations did not improve the protective effect. (5) Evidence regarding the effects of immunization with CI vaccine in buffaloes and F/T vaccine in cattle, on the number of eggs and miracidia and that of female worms themselves was obtained. (6) Immune responses, cellular and humoral, elicited in buffaloes vaccinated with CI schistosomula were detected by means of Lymphocyte Transformation Assay and Enzyme Linked Immunosorbent Assay.

Animals↗
PubMed1993

Changes in platelet-activating factor, catecholamine, and serotonin concentrations in brain, cerebrospinal fluid, and plasma of pichinde virus-infected guinea pigs.

Brain concentrations of platelet-activating factor (PAF), catecholamines, and serotonin were measured in control and Pichinde virus-infected strain 13 guinea pigs on postinoculation day (PID) 12. After virus inoculation, PAF concentrations increased 81% in cerebrum, 147% in diencephalon-brain stem, and 110% in cerebellum from baseline values of 2.6 +/- 0.3, 4.3 +/- 0.2, and 6.1 +/- 0.5 (ng/g wet tissue), respectively. Dopamine concentrations in the infected cerebrum and diencephalon-brain stem increased significantly, whereas norepinephrine concentration increased only in cerebrum. However, serotonin concentrations in all three regions of infected brain decreased significantly as compared with control values. There were no significant changes in epinephrine concentrations of infected brain. Norepinephrine and epinephrine concentrations in plasma and cerebrospinal fluid on PID 7 and 12 increased significantly as compared with control values, while plasma dopamine concentration increased significantly on PID 7. Increased brain PAF, dopamine, and and norepinephrine concentrations with decreased brain serotonin concentrations may mediate the hyperactivity of the hypothalamic-pituitary-adrenal axis and involve some unknown pathophysiologic processes of arenaviral infection. Furthermore, increased plasma catecholamine concentrations are associated with stress and may be partially responsible for the development of cardiovascular dysfunction and pulmonary edema during this viral disease.

Animals↗
PubMed1993

Platelet-activating factor (PAF)-induced cardiopulmonary dysfunctions and their reversal with a PAF antagonist (BN 52021) in strain 13 guinea pigs.

Cardiovascular and respiratory responses to a 2 h intravenous constant infusion of PAF (5 and 10 ng/kg per min) were studied in strain 13 guinea pigs. PAF decreased arterial blood pressure, left systolic ventricular pressure, and cardiac output (CO). These cardiovascular changes were dose-dependent. The PAF-induced hypotension returned to a pre-infusion level spontaneously with increased total peripheral resistance despite continuous infusion of PAF. The decreased CO was most striking, and did not recover to pre-infusion levels due to depressed cardiac contractility and impaired ventricular relaxation. Respiratory responses to PAF infusion at these doses were mild and only occurred after serious cardiovascular dysfunctions developed. A higher dose of PAF (20 ng/kg per min) produced drastically decreased CO and dynamic lung compliance (Cdyn), increased pulmonary airway resistance, hypoventilation and apnea within 10-40 min. BN 52021, a PAF receptor antagonist, administered as a single i.v. dose (6 mg/kg) 15 min after PAF infusion, reversed most of cardiopulmonary dysfunctions and prevented death by increasing cardiac contractility, CO, and minute volume from extremely low values. The data suggest that marked cardiopulmonary disturbances induced by intravenous PAF infusion reflects certain pathophysiological mechanisms of diseases that may involve the cellular release of PAF. The administration of BN 52021 or other potent PAF antagonists may be beneficial under these circumstances.

Animals↗
PubMed1993

Hepatic and extrahepatic HCV RNA strands in chronic hepatitis C: different patterns of response to interferon treatment.

We investigated the presence of positive (genomic) and negative (replicative intermediate) hepatitis C virus RNA strands in liver, peripheral mononuclear cells and serum from patients with chronic hepatitis C using a selective and semiquantitative polymerase chain reaction procedure. Negative and positive hepatitis C virus RNA strands were present in liver, serum and lymphoid cells in all untreated patients and in all those who did not respond to interferon therapy. In the latter group of patients, the titers of RNA strands in the liver and peripheral mononuclear cells at the end of the treatment were similar to those encountered in untreated patients, but the serum titers were about 100 times lower than pretreatment values. In patients who responded to interferon with normalization of serum aminotransferase levels (n = 10), the rate of detection and the titer of the two viral strands in liver, serum and mononuclear cells were markedly decreased at the end of the therapy. In the six responders who did not relapse after interferon withdrawal, both hepatitis C virus RNA strands were absent from the liver, serum and lymphoid cells. By contrast, the positive RNA strand was present in liver cells, mononuclear cells or both at the end of therapy in all patients who experienced posttherapy relapse. In conclusion, our results indicate that interferon can clear hepatitis C virus from hepatic and extrahepatic sites only in responder patients. Disappearance of genomic hepatitis C virus RNA from the liver and from mononuclear cells may predict complete response without posttherapy relapse.

Adolescent↗
PubMed1992

The stilbene disulfonic acid DIDS stimulates the production of TNF-alpha in human lymphocytes.

Exposure of human peripheral blood mononuclear cells (PBMC) to the stilbene derivative DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid) (60 microM and above) significantly increased the release of tumor necrosis factor-alpha (TNF-alpha), as determined by TNF-alpha activity in the incubation media. When the TNF-alpha message was analyzed in PBMC by a reverse transcription/polymerase chain reaction (RT/PCR)-based procedure, it was found that incubation with DIDS (60 microM) was followed by a time-dependent accumulation of TNF-alpha mRNA. Measurements of intracellular pH showed that the presence of increasing concentrations of DIDS resulted in a progressive intracellular alkalinization of PBMC. It is suggested that the known DIDS effect of inhibiting transmembrane anion exchange, i.e., chloride/bicarbonate exchange, might play a role in the stimulation of TNF-alpha production by PBMC exposed to DIDS.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1992

Metabolism of platelet-activating factor in neutrophils isolated from Pichinde virus-infected guinea pigs.

Metabolism of platelet-activating factor (PAF) was studied in cultured polymorphonuclear neutrophils (PMNs) obtained from Pichinde virus-infected strain 13 guinea pigs. Neutrophils obtained from control and infected guinea pigs on postinoculation days 10 and 14 were incubated with [3H]lyso-PAF, [3H]PAF, or [3H]acetate. After incubation for 1 h at 37 degrees C, formation of [3H]acyl-PAF from either [3H]lyso-PAF or [3H]PAF increased significantly in PMNs from infected guinea pigs compared to control PMNs. Furthermore, total radioactivity from [3H]lyso-PAF or [3H]PAF was higher in PMNs from infected animals than in those from controls. However, compared to PAF production by control PMNs, production of PAF by infected PMNs was unchanged. These results suggest that PMNs may not be the major source of increased blood PAF levels during Pichinde viral disease.

Acetates↗
PubMed1992

Replication of hepatitis C virus in peripheral blood mononuclear cells. Effect of alpha-interferon therapy.

Hepatitis C virus (HCV) is a positive-stranded RNA virus which replicates through a negative-stranded RNA intermediate. Using a PCR procedure to detect positive and negative strands, we investigated the existence of HCV replication in lymphoid cells. Both positive and negative strands were found in the peripheral blood mononuclear cells (PBMC) of all patients (n = 10) with untreated chronic hepatitis C. No HCV sequences were detected in PBMC in any of the 8 healthy controls. Fifteen patients with chronic hepatitis C were studied at the end of a 12-month course of alpha-interferon therapy. The positive strand was detected in PBMC in all 9 non-responder patients, and the negative strand in 7. In contrast, in PBMC from responder patients (n = 6) the positive strand was found in 4 and the negative strand in only 2 cases. These results demonstrate that HCV can infect PBMC and replicate in these cells and that interferon seems to exert an inhibitory effect on this process. Persistence of HCV-RNA in PBMC may help explain disease relapse after successful interferon therapy.

Adult↗
PubMed1992

Increased platelet-activating factor (PAF) concentrations in hearts and lungs of Pichinde virus-infected guinea pigs.

Platelet-activating factor (PAF) has been implicated as a cause of cardiopulmonary disturbances in certain diseases. In the present study, concentrations of PAF in hearts, lungs, whole blood, and other organs of control and Pichinde virus-infected guinea pigs on post-inoculation days (PID) 10 and 14 were measured by radioimmunoassay. Results were further confirmed by bioassay after separation and purification with thin-layer chromatography. PAF concentration in the hearts and lungs of virus-infected animals increased significantly on PID 10 and 14, as compared with control levels. PAF level in the blood of infected guinea pigs also significantly increased on PID 14. There was little change of PAF levels in liver and kidney after viral inoculation. Increased PAF concentrations in both hearts and lungs of infected strain 13 guinea pigs suggest that this lipid mediator may play an important role in the development of cardiopulmonary disturbances.

Animals↗
PubMed1987

Control of Aedes aegypti larvae in household water containers by Chinese cat fish.

In 1980-81 an outbreak of dengue fever occurred in Guangdong province and in Guangxi-Zhuang autonomous region in the central-southern part of China. Subsequently, a nationwide survey indicated that the vector of the disease, Aedes aegypti, was confined to the coastal strip of Guangdong and Guangxi-Zhuang. Since the first case in the outbreak occurred in Guangxi-Zhuang, a community-based programme to control A. aegypti was set up in eight fishing villages of this region where the mosquito was breeding in household water containers. The principal method of control was use of the indigenous edible fish Clarias fuscus (Chinese cat fish), which is highly larvivorous and tolerant of harsh environmental conditions. Each container was stocked with a young fish, which could survive there for periods of up to a year. A team of primary medical personnel (barefoot doctors) made sure that the programme was correctly implemented. The programme was monitored from 1981 to 1985 in three of the villages, and the results indicated that the Breteau index remained at a low level throughout this period.

Aedes↗
PubMed1985

Epidemiologic study on the skin lesions of workers exposed to N,N'-methylene-bis-(2-amino-1,3,4-thiadiazole) and of children in the neighborhood of the factory.

The air in a factory producing N,N' methylene-bis-(2-amino-1,3,4-thiadiazole) (MATDA) and water in a nearby river were often polluted by the intermediate and finished product. The levels of MATDA in the air, soil, and river water were 0.1-0.8 mg/m3, 6-2 650 mg/kg, and 0.5-2 mg/kg, respectively. Seventy-nine workers engaged in MATDA production were observed; 44% of them suffered from contact dermatitis; and 72% showed changes of pigment in the skin (versus 2 and 16%, respectively, for the referents). All of the exposed workers had experienced dermatitis at some time. For 218 pupils of a primary school in the neighborhood of the factory, the incidence of hypopigmentation and pigmentation of the skin was 14 and 72%, respectively, but in the reference group the corresponding incidence rates were 0 and 20%. Pigment changes of workers' children increased with the duration of residence in the neighborhood of the factory. The results of the survey led to a change in the formulation of the product from a powder to an emulsion. Improved technology was also initiated which allowed most of the waste to be reused in the processing. After these control measures the dermatitis of the workers was greatly reduced.

Adolescent↗
PubMed1981

Markov chain as a model of Hill's theory on circulation.

Establishing a model for various kinds of vivid metabolic systems of living organisms is an subject, uneasy but of great significance. Hill has constructed a theoretical framework for discussions of metabolic systems, such as active transport, muscle contraction, etc. The basic method of his framework is diagram calculation for the cycle flux on the metabolic cycles of those systems [2, 7] He has successively found that the result from diagram calculations agrees with the data of the numbers of completing different cycles given by random test (Monte Carlo test), but has not yet proved that the former is just the circulation rate in the sense of trajectory. In this paper, the model of a Markov chain is used to define the circulation rate in the sense of trajectories and, by deriving the remaining Markov chains, we calculate the expression of circulation rate which coincides with Hill's result obtained from diagrams. And hence we verify that Hill's cycle flux is equivalent to the circulation rate defined by trajectory. Besides, this paper establishes a connection between Hill's free energy of small systems and the potential of a Markov chain which is suggested by Hou Zhenting.

Markov Chains↗
PubMedDate not supplied

Different mechanisms of aralkylation of adenosine at the 1- and N6-positions.

The eight products resulting from opening of either enantiomer of styrene oxide at the alpha- or beta-carbon by the 1- or N6-positions of adenosine were prepared and their configurations assigned. These markers allowed the mechanism of aralkylation of adenosine by styrene oxide to be investigated. It was found that formation of alpha-substituted products at the 1-position of adenosine involved total inversion of stereochemistry, whereas at the N6-position inversion: retention was approximately 6:1. These differences in stereochemistry suggest that a more ionic form of styrene oxide is involved in N6-aralkylation than in 1-aralkylation of adenosine. In the course of these studies, it was found that 1-substituted adenosines at the alpha- and beta-carbon of styrene oxide undergo Dimroth rearrangement at neutral pH and 37 degrees C and that the former compound also deaminates fairly readily under these conditions.

Adenosine↗