The author investigated the larvicidal action of liquid nitrogen against the metacercariae of Clonorchis sinensis, with an observation on the freshness and change of taste in the flesh of fishes. The results obtained were as follows: The metacercariae in the flesh of Pseudorasbora parva, which were treated with liquid nitrogen (-192C), were not killed within 10 seconds, but completely killed over 30 seconds. In comparison, the metacercariae in the flesh of P. parva kept in a refrigerator (-12C) were killed only in 84 percent in 10-hour exposure group. The freezing speed of fishes by liquid nitrogen was 4 min. (') and 15 seconds(") for Cyprinus carpio, 1'22'' for Carassius carassius and only 30'', for Pseudorasbora parva. As for the freshness and taste of raw fresh water fishes, they were not deteriorated after the treatment with liquid nitrogen. In animal infection experiment of C. sinensis metacercariae after freezing, they were found not infective after they were treated with liquid nitrogen. From the results, it is inferred that the treatment of fresh water fishes for longer than 30 seconds with liquid nitrogen is helpful to reduce the possibility of C. sinensis infection without alteration of the freshness and taste of fishes.
parasitolgy-helminth-trematoda ; Clonorchis sinensis ; metacercaria ; toxicology ; liquid nitrogen

This study was developed and validated for the determination of oxyclozanide residue concentrations in beef and commercial milk, using high-performance liquid chromatography system. Oxyclozanide was successfully separated on a reverse phase column (Xbridge-C18, 4.6x250 mm, 5 microm) with a mobile phase composed of acetonitrile and 0.1% phosphoric acid (60:40, v/v%). This analytical procedure involved a deproteinization process using acetonitrile for beef and 2% formic acid in acetonitrile for commercial milk, dehydration by adding sodium sulfate to the liquid analytical sample, and a defatting process using n-hexane; after these steps, the extract was exposed to a stream of nitrogen dryness. The final extracted sample was dissolved in the mobile phase and filtered using a 0.45 microm syringe filter. This method had good selectivity and recovery (70.70+/-7.90-110.79+/-14.95%) from the matrices. The LOQs ranged from 9.7 to 9.8 microg/kg for beef and commercial milk. The recoveries met the standards set by the CODEX guideline.
Acetonitriles ; Chromatography, High Pressure Liquid ; Chromatography, Liquid ; Dehydration ; Formates ; Milk ; Nitrogen ; Oxyclozanide ; Phosphoric Acids ; Rivers ; Sodium ; Sulfates ; Syringes

OBJECTIVES: To establish the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to detect ethanol metabolites phosphatidylethanol (PEth) in whole blood. METHODS: An appropriate amount of aqueous solution including 1% formic acid was added to 100 μL whole blood, the protein was precipitated with acetone, centrifuged and the supernatant was purified and enriched by using Bond Elut Certify column. The eluent was redissolved with 1/1 isopropanol/acetonitrile (v/v) solution after nitrogen blowing and then tested by UPLC-MS/MS. Selective reaction monitoring scanning was carried out in negative ionization mode, and quantitative analysis was performed by external standard method. RESULTS: PEth showed a linear relationship over the concentration range of 1-160 ng/mL in whole blood (r=0.999 9) with peak area. The detection limit was 0.2 ng/mL, the quantification limit was 1 ng/mL, the recovery rate was 97.43%-103.61%, the accuracy was 0.99%-1.77%, the intra-day precision was 0.4%-2.4%, and the inter-day precision was 1.1%-3.3%, and the matrix effect was 91.00%-99.55%. PEth was not detected in the in vitro blood samples supplemented with ethanol. PEth was detected positive in three drunk driving cases, and the concentration were 195.49, 83.67 and 876.12 ng/mL, respectively. CONCLUSIONS The established method has high sensitivity and specificity and the analysis results are accurate. It is suitable for the qualitative and quantitative analysis of PEth in whole blood.
2-Propanol ; Acetone ; Acetonitriles ; Biomarkers ; Chromatography, High Pressure Liquid/methods* ; Chromatography, Liquid ; Ethanol ; Glycerophospholipids ; Nitrogen ; Tandem Mass Spectrometry/methods*

To investigate the N-containing compounds in the seeds of Paganum harmala,fourteen compounds were finally isolated from the 95% Et OH extract of P. harmala seeds by using various chromatographic techniques including silica gel,MCI resin,and ODS column chromatography as well as the semi-preparative HPLC. Depending on spectroscopic techniques and comparison with the reported data in the literatures,the structures of all compounds were identified as N-[3-(2-amino-4-methoxyphenyl)-3-oxopropyl]acetamide(1),dehydroharmalacidine(2),harmalacidine(3),harmine N-oxide(4),harmine(5),tetrahydroharmine(6),demethylharmalacidine(7),harmol(8),tetrahydroharmol(9),harmindol β-D-glucopyranoside(10),tryptophyl β-D-glucopyranoside(11),pegamineβ-D-glucopyranoside(12),vasicol(13) and vasicinone(14). Among them,1 was a new compound,and 2 and 10 were obtained as natural products for the first time.
Chromatography, High Pressure Liquid ; Nitrogen ; analysis ; Peganum ; chemistry ; Phytochemicals ; analysis ; Plant Extracts ; chemistry ; Seeds ; chemistry

OBJECTIVETo investigate the effects of nitrogen concentration on the camptothecin (CPT) content in Camptotheca acuminata seedlings:

METHODThe seedlings of C. acuminata with 6 pair of leaves were subjected to five nitrogen concentrations treatments by sand culture in a greenhouse. The CPT content in the seedlings was determined by HPLC on the 20th, 35th, 50th, 65th and 80th day respectively.

RESULTThe CPT content in the young leaves of C. acuminata seedlings supplied with different nitrogen concentration was significantly higher than that in other organs (P < 0.01), and it showed a single peak curve with the time course, the highest CPT content was observed on the 50th day after treatment. The CPT content in the young leaves obviously declined with increasing nitrogen concentration, and it reached the highest (6.72%) when nitrogen concentration was 4 mmol x L(-1), equal to 1.1 times that of 16 mmol x L(-1) nitrogen.

CONCLUSIONThe results demonstrate that proper deficient nitrogen stress can significantly enhance CPT accumulation in young leaves of C. acuminata seedlings.

Camptotheca ; drug effects ; metabolism ; Camptothecin ; metabolism ; Chromatography, High Pressure Liquid ; Nitrogen ; pharmacology ; Seedlings ; drug effects ; metabolism

OBJECTIVETo develop a HPLC method for the quantitative determination of four nitrogenous compounds in Pinellia peda-tisecta.

METHODThe determination was carried out on Diamonsil-C18 column(4. 6 mm x 250 mm, 5 microm) eluted with acetonitrile-water-triethylamine in gradient elution acetonitrile-water- triethylamine. The mobile phase was a flow rate of 1.0 mL x min(-1) and detection wavelength as 254 nm.

RESULTThe linear ranges of trigonelline, thymine, amidopurine and hypoxanthine were 0.2 - 1.0 microg (r = 0.999 6), 2.6-13 microg (r = 0.999 8), 0.55-2.75 microg (r = 0.999 9), 0.65-3.25 microg (r = 0.999 8), respectively. The average recoveries of trigonelline, thymine, amidopurine and hypoxanthine were 100.6%, 99.89%,100.5% and 100.0% respectively, and the RSD of the above four compounds were 2.4%, 0.20%, 1.1%, 1.4%, respectively.

CONCLUSIONThis method is reliable, accurate and specific. It can be used for quality control of the tube of P. peda-tisecta.

Chromatography, High Pressure Liquid ; methods ; Drugs, Chinese Herbal ; analysis ; isolation & purification ; Nitrogen Compounds ; analysis ; isolation & purification ; Pinellia ; chemistry

BACKGROUND: This study investigated the protective mechanism of Prostagladin E1 (PGE1) against intimal hyperplasia after vein interposition grafts in rabbits. It has been demonstrated that active oxygen species contribute to vascular smooth muscle cell growth via early cell cycle gene activation. We attempted to study whether PGE1 had an effect on the inhibition of the oxidative stress injury index (8-OHdG, MDA). METHODS: Forty-eight jugular vein grafts were inserted into the carotid arteries of male hyperlipidemic New Zealand white rabbits, which were divided into 2 groups (saline group and PGE1 group). Saline and Prostaglandin E1 (0.1 microgram/kg/min) were administered as a continuous infusion for 2 hours every day from just before graft interposition to harvest. The vein grafts were harvested at 6 hour, 1 day, 1 week, and 2 week after grafting and rapidly stored in liquid nitrogen ( 70oC). 8-OHdG was measured by using high performance liquid chromatography coupled with electrochemical detection (HPLC-EC), and malondialdehyde (MDA) was measured by using thiobarbituric acid (TBA) assay. PC 10 index and intimal thickness of the grafts were measured with a computer digitalized image analyzer. RESULTS: There was no difference in 8-OHdG levels between the saline and the PGE1 groups. PGE1 had more inhibitory effect on the MDA level as an oxidative stress injury index, but its action was restricted to 1 day. A morphometric analysis and an immunohistochemical study showed that the PGE1 group had more suppressive effects both in intimal thickeness and proliferating cell nuclear antigen (PCNA) expression than the saline group (p<0.05). CONCLUSION: These results suggest that PGE1 is effective in preventing intimal hyperplasia after vein interposition grafts in rabbits and may play a role in inhibiting oxidative stress injury.
Alprostadil ; Carotid Arteries* ; Chromatography, Liquid ; Genes, cdc ; Humans ; Hyperplasia ; Jugular Veins ; Male ; Malondialdehyde ; Muscle, Smooth, Vascular ; Nitrogen ; Oxidative Stress* ; Proliferating Cell Nuclear Antigen* ; Rabbits ; Reactive Oxygen Species ; Transplants* ; Veins*

We examined whether high flux membranes (HF) may induce a greater loss of amino acids compared to low flux membranes (LF). Ten hemodialysis patients participated in this study. Pre- and post-hemodialysis plasma amino acid profiles were measured by reverse-phase high pressure liquid chromatography for both HF and LF. We measured the dialysate amino acid losses during hemodialysis. The reduction difference for plasma total amino acid (TAA), essential amino acid (EAA), and branch chained amino acid (BCAA) was not significantly different in comparisons between the two membranes. (HF vs. LF; TAA 66.85+/-30.56 vs. 53.78+/-41.28, p=0.12; EAA 14.79+/-17.16 vs. 17.97+/-28.69, p=0.12; BCAA 2.21+/-6.08 vs. 4.16+/-10.98 mg/L, p=0.13). For the HF, the reduction in plasma amino acid levels for TAA and EAA were statistically significant. Although it was not statistically significant, the dialysate losses of BCAA were greater than the reduction in plasma (plasma reduction vs. dialysate loss; HF 2.21+/-6.08 vs. 6.58+/-4.32, LF 4.16+/-10.98 vs. 7.96+/-3.25 mg/L). HF with large pores and a sieving coefficient do not influence dialysate amino acid losses. Hemodialysis itself may influence the dialysate amino acid losses and may have an effect on protein metabolism.
Adult ; Aged ; Amino Acids/*blood/chemistry ; Bicarbonates/blood ; Blood Urea Nitrogen ; Chromatography, High Pressure Liquid ; Creatine/blood ; Dialysis Solutions/analysis ; Female ; Humans ; Male ; *Membranes, Artificial ; Middle Aged ; Potassium/blood ; Renal Dialysis/*instrumentation ; Sodium/blood

BACKGROUND: Metformin is an effective oral antihyperglycaemic agent for type 2 diabetes mellitus, with a variety of metabolic effects. In addition to controlling blood glucose level, it has been appeared to decrease the long-period complications of diabetes, including macrovascular disease. Few reports have addressed the metabolite profiling of metformin. The study was to evaluate if targeted metabolic profiling approach is sensitive enough to predict the therapeutic effects of metformin after a single oral dose. METHODS: A randomized, open-label, single-dose study was conducted in twenty eight healthy Korean male volunteers. To determine the concentrations of endogenous metabolites in their pre-dose and post-dose plasma samples, blood samples were collected before and at 2 and 6 h after a single oral dose of 500 mg metformin. Both Modular P/Modular D analyzer and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS)-based metabolic profiling was performed. RESULTS: We quantified pre-dose and post-dose creatinine, blood urea nitrogen (BUN), lactic acid, 7 amino acids (lysine, glutamic acid, alanine, valine, leucine, phenylalanine, tryptophan), and 5 lysophosphatidylcholines (14:0, 16:0, 17:0, 18:0, and 18:1) using autoanalyser and UPLC-MS/MS. The postdose levels of alanine, lactic acid, glutamic acid, lysine, valine, leucine, phenylalanine, tryptophan, and lysoPC (18:1) were slightly decreased with statistical significance, but there is no clinical significance. CONCLUSION: In order to explore the potential endogenous metabolites associated with the therapeutic effects of metformin, further study including non-targeted (global) metabolite profiling is needed.
Alanine ; Amino Acids ; Blood Glucose ; Blood Urea Nitrogen ; Chromatography, Liquid ; Creatinine ; Diabetes Mellitus, Type 2 ; Glutamic Acid ; Humans ; Lactic Acid ; Leucine ; Lysine ; Lysophosphatidylcholines ; Male ; Metformin ; Phenylalanine ; Plasma ; Tandem Mass Spectrometry ; Tryptophan ; Valine

BACKGROUND: Metformin is an effective oral antihyperglycaemic agent for type 2 diabetes mellitus, with a variety of metabolic effects. In addition to controlling blood glucose level, it has been appeared to decrease the long-period complications of diabetes, including macrovascular disease. Few reports have addressed the metabolite profiling of metformin. The study was to evaluate if targeted metabolic profiling approach is sensitive enough to predict the therapeutic effects of metformin after a single oral dose. METHODS: A randomized, open-label, single-dose study was conducted in twenty eight healthy Korean male volunteers. To determine the concentrations of endogenous metabolites in their pre-dose and post-dose plasma samples, blood samples were collected before and at 2 and 6 h after a single oral dose of 500 mg metformin. Both Modular P/Modular D analyzer and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS)-based metabolic profiling was performed. RESULTS: We quantified pre-dose and post-dose creatinine, blood urea nitrogen (BUN), lactic acid, 7 amino acids (lysine, glutamic acid, alanine, valine, leucine, phenylalanine, tryptophan), and 5 lysophosphatidylcholines (14:0, 16:0, 17:0, 18:0, and 18:1) using autoanalyser and UPLC-MS/MS. The postdose levels of alanine, lactic acid, glutamic acid, lysine, valine, leucine, phenylalanine, tryptophan, and lysoPC (18:1) were slightly decreased with statistical significance, but there is no clinical significance. CONCLUSION: In order to explore the potential endogenous metabolites associated with the therapeutic effects of metformin, further study including non-targeted (global) metabolite profiling is needed.
Alanine ; Amino Acids ; Blood Glucose ; Blood Urea Nitrogen ; Chromatography, Liquid ; Creatinine ; Diabetes Mellitus, Type 2 ; Glutamic Acid ; Humans ; Lactic Acid ; Leucine ; Lysine ; Lysophosphatidylcholines ; Male ; Metformin ; Phenylalanine ; Plasma ; Tandem Mass Spectrometry ; Tryptophan ; Valine