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Ping Fang

Publications and source records attributed to Ping Fang.

29 records · Page 2Linked to original sources
PubMed2004

[Recent advances in research and application of associated nitrogen-fixation with graminaceous plants].

The category, characteristic of diazotrophs isolated from inside and/or rhizosphere of graminaceous plants in recent year and the mechanism of the promoting effects on their host plant were reviewed in this paper. The current status of application of associative nitrogen-fixation inoculants and the problems in inoculation were discussed. It was indicated that the main factors influencing the effects of inoculants include the competition of indigenous micro-organism with inoculants for nutritions and energy, difference of host plant genotypes in associative relationship, and variance of environmental conditions such as the concentration of ammonium in soil solution and the oxygen partial pressure in soil air. The trends of future research in this field were prospected, for example, to isolate and identify the high nitrogen fixing efficiency strains with wider environmental adaptability, to create associative nitrogen fixing bacteria strain which is able to bear or endure higher concentration of ammonium by gene engineering technique, to induce graminaceous plant forming root nodule for nitrogen fixation and to exert the predominance of endophytic diazotrophs.

Acetobacter↗
PubMed2004

[Analysis of resveratrol by pressurized-capillary electrochromatography].

trans-Resveratrol and cis-resveratrol were analyzed using pressurized-capillary electrochromatography (CEC). The effects of illumination by sunlight to the samples were investigated. The concentration of resveratrol in wines was determined with qualitative and quantitative analysis of resveratrol. As a technique with high efficiency and high resolution, CEC proved to be a viable alternative for the quantitative analysis of wines.

Capillary Electrochromatography↗
PubMed2003

Synthesis of N,N-dimethyl-2-(2-amino-4-[18F]fluorophenylthio)benzylamine as a serotonin transporter imaging agent.

Two 403U76 analogs, N,N-dimethyl-2-(2-nitro-4-bromophenylthio)benzylamine (4) and N,N-dimethyl-2-(2,4-dinitrophenylthio)benzylamine (8) were prepared in multi-steps synthesis as precursors for the synthesis of a new serotonin transporter imaging agent, N,N-dimethyl-2-(2-amino-4-[18F]fluorophenylthio)benzylamine (12a). Reaction of 2,5-dibromonitrobenzene (1) with 2-thio-N,N-dimethylbenzamide gave N N-dimethyl-2-(2-nitro-4-bromophenylthio)benzamide (3). N,N-Dimethyl-2-(2,4-dinitrophenylthio)benzamide (6) was synthesized similarly from the reaction of 2-bromo-1,5-dinitrobenzene (2) with 2-thio-N,N-dimethylbenzamide. Reduction of 3 and 6 with BH(3)/THF gave benzylamines 4 and 8 along with their amine boranes 5 and 7. Nucleophilic substitution of 4 or 8 with K[18F]/Kryptofix 2.2.2 in DMSO at 120 degrees C followed by reduction with NaBH(4)- Cu(OAc)(2) in EtOH at 78 degrees C and purification with HPLC gave compound 12a in approximately 5-10% yield in a synthesis time of 150min from EOB. A preliminary biodistribution study in rats showed that the uptake of compound 12a in rat brain was high (approximately 1%/g) and the ratio of the uptake of compound 12a in hypothalamus (a serotonin transporter-rich area) and cerebellum (a serotonin-transporter-devoid area) was 6/1 at 1h post-injection. These results suggest that compound 12a may be a potential new serotonin transporter PET imaging agent.

Animals↗
PubMed2003

[A clinical study on improving phonation function of larynx after partial laryngectomy].

OBJECTIVE: To analyse the clinical results of reconstruction of vocal cord using sternohyoid muscle flap after partial laryngectomy and research a new repairing method to improve laryngeal function and living quality of patient. METHOD: The pronunciation of larynx is on the basic of the vibration of the vocal cord by air current. The laryngeal appearance and the function of opposite side vocal cord is very important for improving the quality of pronunciation. We developed a technique of thyroid cartilage membrane and sternohyoid muscle flap to repair the defect left by a vertical laryngectomy and reconstructed the vocal cord. The thyroid cartilage membrane was used to bridge over the upper part defect of laryngeal cavity, the sternohyoid muscle flap forming the opposite side was made a 90 degree bent toward the laryngeal cavity to repaired the lower part defect of laryngeal cavity and reconstruct a new vocal cord. The repaired larynx recovered the normal appearance. The new vocal cord participated speech. The anterior 2/3 part of both vocal cored could contacted in pronunciation of patient. The phonation function of larynx was restored. RESULT: Sixty-one cases partial laryngectomy was taken including vertical partial laryngectomy in 37 cases, extended vertical partial laryngectomy in 24. During their operations, the laryngeal defect was repaired with thyroid cartilage membrane and sternohyoid muscle flap, and a vocal cord was reconstructed in the same time. After operation, the laryngeal cavity repaired has a normal appearance, and the laryngeal satisfactory phonation effect has been obtained. 93.4% of the patients enjoyed a socially acceptable voice and rejoined normal working. CONCLUSION: A technique of thyroid cartilage and sternohyoid muscle flap to repair the defect and reconstructive vocal cord after partial laryngectomy make patient recover normal laryngeal appearance and obtain satisfactory phonation effect. Among the method of repairation for partial laryngectomy sternohyoid muscle flap should be first considered owing to its various merits: 1. abundant material. 2. convenient procedures. 3. smaller trauma. 4. satisfactory effect.

Adult↗
PubMed2003

Portal hypertensive gastropathy and its interrelated factors.

OBJECTIVE: To investigate the influences of helicobacter pylori (Hp) infection, liver function, gastroesophageal varicosity, esophageal varicosity ligation (EVL), and esophageal varicosity sclerotherapy (EVS) on patients with portal hypertensive gastropathy (PHG). METHODS: Fourty-seven patients with liver cirrhosis included 34 patients with PHG and 13 patients without PHG. Liver function, Hp infection, and gastroesophageal varicosity were investigated clinically in all patients, and gastroscopy was made again in patients with EVL 1-2 months after operation to observe the changes of PHG. RESULTS: The rate of Hp infection was lower in patients with liver cirrhosis than in controls. There was no relationship between Hp infection and PHG. The patients with gastroesophageal varicosity had a high incidence of PHG. CONCLUSIONS: Despite no relationship between Hp infection and PHG, liver dysfunction can affect and promote PHG. Gastroesophageal varicosity may be closely related to PHG, but their degrees are not related. PHG can be caused or promoted by EVL.

Adolescent↗
PubMed2003

N,N-dimethyl-2-(2-amino-4-(18)F-fluorophenylthio)-benzylamine (4-(18)F-ADAM): an improved PET radioligand for serotonin transporters.

UNLABELLED: There has been considerable interest in the development of PET radioligands that are useful for imaging serotonin transporter (SERT) in the living human brain. For the last decade, (11)C-(+)McN5652 has been the most promising PET agent for studying SERT in humans. However, this agent has some limitations. Recently, a new promising SERT PET radioligand, 3-(11)C-amino-4-(2-dimethylaminomethylphenylsulfanyl)benzonitrile, has been reported. We recently reported the synthesis of a new (18)F-labeled SERT PET radioligand, N,N-dimethyl-2-(2-amino-4-(18)F-fluorophenylthio)benzylamine (4-(18)F-ADAM), which may have advantages over (11)C-labeled radioligands. The purpose of this study was to evaluate this newly developed (18)F-labeled PET radioligand as a promising agent for studying SERT in the living human brain. METHODS: This agent was evaluated by studying its in vitro binding to different monoamine transporters, its in vivo biodistributions in rats, its integrity and pharmacologic profiles in rat brain, and its distribution in a female baboon brain. RESULTS: In vitro binding assays showed that 4-F-ADAM displayed high affinity to SERT sites (inhibition constant = 0.081 nmol/L, using membrane preparations of LLC-PK1 cells expressing the specific transporter) and showed more than 1,000- and 28,000-fold selectivity for SERT over norepinephrine transporter and dopamine transporter, respectively. Biodistribution of 4-(18)F-ADAM in rats showed a high initial uptake and slow clearance in the brain (2.13%, 1.90%, and 0.95% injected dose per organ at 2, 30, and 60 min after intravenous injection, respectively), with the specific binding peaking at 2 h after injection (hypothalamus/cerebellum = 12.49). The uptake in blood, muscle, lung, kidney, and liver was also initially high but cleared rapidly. The radioactivity in the femur increases with time for 4-(18)F-ADAM, indicating that in vivo defluorination may occur. In vivo metabolism studies in rats showed that 4-(18)F-ADAM was not metabolized in rat brain (>96% of radioactivity was recovered as parent compound at 1 h after injection). However, it metabolized rapidly in the blood. Less than 7% of the radioactivity recovered from plasma was the parent compound, with the majority of radioactivity in the plasma not extractable by ethyl acetate. Blocking studies showed significant decreases in the uptake of 4-(18)F-ADAM in the brain regions (hypothalamus, hippocampus, and striatum) where SERT concentrations are high when rats were pretreated with (+)McN5652 (2 mg/kg 5 min before intravenous injection of 4-(18)F-ADAM). However, changes in the uptake of 4-(18)F-ADAM in these brain regions were less significant when rats were pretreated with either methylphenidate or nisoxetine. The baboon study showed that uptake of 4-(18)F-ADAM in the midbrain peaked at approximately 1 h after injection and then declined slowly. The ratios of the radioactivity in the midbrain to that in the cerebellum (where the concentration of SERT is low) at 2 and 3 h after injection were 3.2 and 4.2, respectively. CONCLUSION: 4-(18)F-ADAM is suitable as a PET radioligand for studying SERT in the living brain. Further characterization of this new radioligand in humans is warranted.

Animals↗
PubMed2003

[Detection of linear chromosomes and plasmids among 15 genera in the Actinomycetales].

Bacterial chromosomes and plasmids are commonly circular, however, linear chromosomes and plasmids were discovered among 5 genera of the Actinomycetales. Here, we use pulsed field gel electrophoresis to study the genomes of 19 species which belong to 15 genera in the Actinomycetales. All chromosomes of 19 species are linear DNA, and linear plasmids with different sizes and copy numbers are detected among 5 species. This work provide basis for investigating the possible novel functions of linear replicons beyond Streptomyces and also helps to develop Actinomycetales artificial linear chromosome.

Actinomycetales↗
PubMed2002

[Different effects of acetylcholine on the action potential and force contraction in guinea pig atrial and ventricular myocardium].

The purpose of this study was to investigate the different effects of ACh on the action potential and force contraction in guinea pig atrial and ventricular myocardium by using standard microelectrodes and force transducer. The results showed that the duration of the action potential (APD) of atrial myocardium was shortened from 208.57+/-36.05 to 101.78+/-14.41 ms (n=6, P<0.01), and the APD of the ventricular myocardium was shortened from 286.73+/-36.11 to 265.16+/-30.06 ms (n=6, P<0.01).The amplitude of the action potential (APA) of the atrial myocardium was decreased from 88.00+/-9.35 to 62.62+/-20.50 mV (n=6, P<0.01), while the APA of the ventricular myocardium did not change significantly.The force contraction of atrial myocardium was inhibited completely (n=6, P<0.01), while the force contraction of ventricular myocardium was inhibited by 37.57+/-2.58% (n=6, P<0.01). The ACh effects correlated with its concentration. The K(D) of the APD shortening effects in the atrial and ventricular myocardium were 0.275 and 0.575 micromol/L. The K(D) of the negative inotropic in the atrial and ventricular myocardium were 0.135 and 0.676 micromol/L, respectively. The corresponding data points were compared using t test between the atrial and ventricular myocardium, and the differences were significant when the ACh concentration was above 10 nmol/L. Furthermore, atropine (10 micromol/L) and CsCl (20 mmol/L) blocked the effects of 10 micromol/L ACh on the APD of ventricular myocardium, while CdCl2 (0.1 mmol/L) had no influence on these effects. In conclusion, ACh could shorten the action potential duration and inhibit the force contraction of atrial and ventricular myocardium in a concentration-dependent manner. There are differences in the effects of ACh on the atrial and ventricular myocardium. The atrial myocardium is more sensitive to ACh than the ventricular myocardium. It is probable that the muscarinic receptor and the potassium channel, but not the calcium channel, are involved in the ACh-induced shortening of the ventricular APD.

Acetylcholine↗