Flow injection chemiluminescence determination of captopril based on its enhancing effect on the luminol–ferricyanide/ferrocyanide reaction

A new flow injection chemiluminescence method is described for the determination of captopril. It is based on the enhancing effect of captopril on the chemiluminescence reaction of luminol with potassium ferricyanide in alkaline solution in the presence of potassium ferrocyanide. The method allows the determination of captopril over 0.1–40 µg/mL range, with a relative standard deviation (SD) of 1.0% for the determination of 0.5 µg/mL captopril solution in 11 repeated measurements. The method was satisfactorily applied to the determination of captopril in commercial captopril tablets. The possible reaction mechanism is also discussed briefly. Copyright © 2002 John Wiley & Sons, Ltd.     

Cloned goats (Capra hircus) from adult ear cells

The average number of available oocytes recovered per ovary collected during the breeding season in dairy goats was 5.5 (1815/330). 66.17% (1201/1815) of oocytes extruded the first polar body after maturation in vitro for 20 h. 75.44% (906/1201) of matured oocytes with membrane evagination around the MⅡchromosomes were enucleated. Ear skin fibroblast cells were derived from an adult female Jining Grey goat (C. hircus). The cells were cryopreserved in liquid nitrogen after passage 2. Thawed cells were further cultured for 3-6 passages and were subjected to serum starvation by 0.5% FBS for 2-10 d, then used as donor cells for nuclear transfer. 98.12% (889/906) of the enucleated oocytes were reconstructed by intracytoplasmic injection of karyoplast. The reconstructed embryos were activated by 5 μmol/L ionomycin for 4.5 min and further activated by culturing with 6-dimethylaminopurine (6-DMAP) for 3 h. After 36 h of culture in mCR1aaBF, 76.69% (645/841) of the cloned embryos cleaved. There were no significant differences in development in vitro between the cloned embryos derived from donor cells precooled at 4℃ for 24 h and nonprecooled donor cells. The cleavage rates, 4-cell development, and blastocyst development of reconstructed embryos were 72.48% (79/109), 53.16% (42/79), and 19.05% (8/42) in precooled group; 68.5% (211/308), 59.72% (126/211), and 17.46% (22/126) in nonprecooled group, respectively. Eighteen cloned 4-cell embryos derived from precooled donor cells were transferred and one cloned kid was born. Eighty-four cloned 4-cell embryos derived from nonprecooled donor cells were transferred and no offspring were produced. Of 18 cloned morale from nonprecooled donor cells transferred, one kid was born. The results of microsatellite DNA analyses indicated that the two cloned kids were from the same donor fibroblast cell line derived from an adult goat ear skin.     

Determination of l-glutamate in various commercial soy sauce products using flow injection analysis with a modified electrode

A flow injection analysis (FIA) system with a modified electrode has been developed and optimized for determination of l-glutamate using l-glutamate oxidase (GLOD) (EC 1.4.3.11). GLOD was immobilized on controlled-pore glass using glutaraldehyde. The optimal potential applied on the working electrode was +700mV against a platinum (Pt) reference electrode. The optimal pH and flow rate of the carrier buffer were 7.4 and 1.5ml/min, respectively. A modified electrode was integrated into the FIA system in order to eliminate electroactive interference and it was used to determine l-glutamate in 39 samples of Thai commercial soy sauce products. The results obtained were compared with those obtained from enzymatic assay using glutamate dehydrogenase and those from a chromatographic assay using an amino acid analyser. Good correlations were observed amongst these methods. The results indicated that use of an FIA system with a modified electrode was able to eliminate electroactive interference and was applicable to the determination of l-glutamate in food samples. The modified FIA was faster and simpler than the more common methods of enzymatic and chromatographic analysis.     

Anxiolytic effect of motilin and reversal with GM-109, a motilin antagonist, in mice

There have been few reports on the effects of the brain-gut peptide motilin on the central nervous system (CNS). We administered motilin intracerebroventricularly to mice and investigated the effect of motilin on anxiety using an elevated plus-maze. Motilin produced a significant decrease in anxiety with an inverted U-shaped dose response. To determine whether the anxiolytic effect of motilin was mediated via motilin receptors in the brain, the effect of GM-109, a novel motilin receptor antagonist, was investigated. GM-109 showed a significant and dose-dependent antagonism on the motilin-induced anxiolytic effect. GM-109 administered alone had no effect on anxiety. These results suggest that motilin receptors are present in the brain and may have a role in anxiety and emotion.     

内皮素-1前体基因反义寡核苷酸对正常和高血压大鼠血流动力学的影响

我们筛选出针对内皮素－１（ＥＴ－１）前体基因反义硫代寡核苷酸片断（ＥＴＡＳＯＤＮ）,已证明ＥＴＡＳＯＤＮ能显著抑制培养内皮细胞ＥＴ－１的生成,本应用该片断,对下沉和腹主动脉狭窄－高盐摄入型高血压大鼠侧脑室进行注射,记录注射前后血流动力学指标、注射后侧脑室周围组织中ＥＴ－１的含量及分布,ＥＴＡＳＯＤＮ对正常和高血压大鼠的影响,发现高血压大鼠脑干ＥＴ－１含量明显高于正常大鼠;ＥＴＡＳＯＤＮ能降低高血压     

Use of a micro-expanded bed containing immobilised lysozyme for cell disruption in flow injection analysis

A method for cell disruption in Flow Injection Analysis (FIA) systems has been developed. The principle involves on-line cell disruption by means of immobilised lysozyme followed by an ultrasonic treatment. In order to avoid flow problems in the analytical system, the lysozyme was immobilised to Streamline^reg that was used in an expanded bed in the flow system. Samples of suspensions of Micrococcus lysodeikticus were treated and the success of the treatment was evaluated in terms of released protein and as a decrease in the optical density at 450 nm. The new technology offers a powerful tool in flow injection analyses for quantification of intracellular compounds. The concept of integration, i.e. combining cell disruption with handling of cell debris and assay procedure in one continuous flow process facilitates its use and increases the probability of reaching reproducible and reliable results.     

A low temperature microbial biosensor using immobilised psychrophilic bacteria

A psychrophilic bacteria, Deinococcus radiodurans, was used to construct a biosensor to be used in a flow injection system. The transducer used was an O₂ electrode. The response of this cell-based electrode was studied towards a number of sugars. The temperature dependence of the electrode response correlated well with the behavior of the cells. Thus, the optimum temperature for measurement of glucose (0.55 mM) was about +5°C. Since the organism used is psychrophilic, a response time at this low temperature is similar to what is achieved with mesophilic organisms at room temperature. This is the first biosensor constructed using a psychrophilic microorganism.     

Determination of procaine hydrochloride using flow injection inhibitory chemiluminescence

A new flow injection chemiluminescent method has been developed for the determination of procaine hydrochloride, based on the inhibition of the chemiluminescence reaction of luminol–hydrogen peroxide by procaine hydrochloride. The influence of several surfactants and β‐cyclodextrin on the chemiluminescence intensity were studied. It was found that β‐cyclodextrin enhanced the decrease in chemiluminescence intensity. The method is simple, convenient and sensitive, with a detection limit (3 σ) of 0.08 µg/mL. The decreased chemiluminescence intensity is linear, with the concentration of procaine hydrochloride in the range 0.2–100.0 µg/mL and 100.0–400.0 µg/mL. The relative standard deviation for 10 repeated measurements were 4.5% and 3.4% for 1.0 and 20.0 µg/mL procaine hydrochloride, respectively. The method has been successfully applied to the determination of procaine hydrochloride in injection solutions of this drug. Copyright © 2003 John Wiley & Sons, Ltd.     

Determination of parathion residues in rice samples using a flow injection chemiluminescence method

A sensitive ?ow injection chemiluminescence method is described for the determination of parathion pesticide, based upon its direct chemiluminescence reaction with luminol and hydrogen peroxide in the presence of non‐ionic surfactant polyethylene glycol 400. Under the selected experimental conditions, the concentration of parathion is proportional to the CL intensity in the range 0.02–1.0 mg/L. The detection limit was 0.008 mg/L and the relative standard deviation was 2.8% for 0.2 mg/L parathion solution (n = 11). This method was successfully applied to the determination of parathion residue in rice samples. Copyright © 2003 John Wiley & Sons, Ltd.     

Hydrazine-induced post-chemiluminescence phenomenon of permanganate-luminol reaction and its applications.

The post-chemiluminescence phenomenon arising from the permanganate-luminol reaction induced by hydrazine and isoniazid was investigated. When hydrazine or isoniazid was injected into the mixture after the end of the reaction of permanganate with alkaline luminol, a new chemiluminescence (CL) reaction was initiated and strong CL signal was detected. A possible CL mechanism is suggested, based upon the studies of the kinetic characteristics of the CL reaction, the UV-visible spectra, the CL spectra and some other experiments. The present reactions allow the determination of 0.1-10.0 mg/L hydrazine and 0.02-1.0 mg/L isoniazid, with detection limits of 0.03 mg/L and 0.006 mg/L, respectively. The method was applied to the determination of isoniazid in pharmaceutical preparations.