scholarly journals High-pressure liquid chromatographic analysis of anaerobic photoproducts of bilirubin-IX α in vitro and its comparison with photoproducts in vivo

1980 ◽  
Vol 190 (3) ◽  
pp. 527-532 ◽  
Author(s):  
S Onishi ◽  
N Kawade ◽  
S Itoh ◽  
K Isobe ◽  
S Sugiyama
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Biological Fluids ◽  
Gel Filtration ◽  
Filtration Method ◽  
Bilirubin Metabolism ◽  
Liquid Chromatographic

To carry out photochemical experiments under conditions similar to those prevailing for neonatal bilirubin metabolism in jaundice phototherapy, we have studied photoproducts produced by the action of light on a bilirubin—albumin solution and further clarified the relationship between the photoproducts obtained from experiments in vitro and in vivo. (1) An accurate and sensitive separation method by high-pressure liquid chromatography for photoproducts of bilirubin under anaerobic irradiation of visible light is described. (2) There were two main photoproducts obtained from experiments both in vivo and in vitro. (3) Exact correspondence of retention time on high-pressure liquid chromatography, diazo-reactivity, thermal reversion and absorption-spectrum maxima was observed between unknown pigment and photobilirubin-IX alpha from biological fluids, and the comparable peaks 2 and 3 from experiments in vitro. (4) The behaviour of photoproducts in various solutions in the absence of light and O2 is described. (5) A lower affinity of photoproducts, especially unknown pigment, for human serum albumin than with bilirubin-IX alpha for the albumin was demonstrated by the gel-filtration method.

Vasopressin is metabolized by a trypsinlike enzyme in guinea pig amniotic fluid

1989 ◽  
Vol 257 (3) ◽  
pp. E354-E360 ◽  
Author(s):  
C. F. Uyehara ◽  
A. K. Sato ◽  
J. R. Claybaugh
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Guinea Pig ◽  
Amniotic Fluid ◽  
High Pressure Liquid Chromatography ◽  
Trypsin Inhibitor ◽  
Arginine Vasopressin ◽  
Proteolytic Enzyme

We have demonstrated that arginine vasopressin (AVP) is degraded to desglycinamide AVP by a trypsinlike enzyme found in guinea pig amniotic fluid. Incubation of [3H]AVP with guinea pig amniotic fluid in vivo or in vitro produced a metabolite that comigrated on high-pressure liquid chromatography with desglycinamide AVP in three different buffer systems. Also, AVP antisera that cross-reacted with standard desglycinamide AVP could detect this amniotic fluid metabolite. Because the enzyme responsible for the cleavage of glycinamide from AVP was likely to be trypsin, experiments with aprotinin, a trypsin inhibitor, were conducted. Results demonstrated that the production of the amniotic fluid AVP metabolite could be completely blocked in the presence of the trypsin inhibitor. In addition, examination of amniotic fluid collected from fetuses in the second half of gestation (term = 68 days) showed that AVP could not be metabolized to desglycinamide AVP until after 52 days of gestation. In conclusion, AVP appears to be metabolized by a trypsinlike enzyme in amniotic fluid, and because trypsin is a general proteolytic enzyme, the amniotic compartment may also serve as a clearance site for other proteins.

scholarly journals Pitfalls in Cefepime Titration from Human Plasma: Plasma- and Temperature-Related Drug Degradation In Vitro

2002 ◽  
Vol 46 (11) ◽  
pp. 3654-3656 ◽  
Author(s):  
Denis Bugnon ◽  
Eric Giannoni ◽  
Paul Majcherczyk ◽  
Michel P. Glauser ◽  
Philippe Moreillon
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Human Plasma ◽  
High Pressure Liquid Chromatography ◽  
Drug Degradation ◽  
Related Drug

ABSTRACT While developing a high-pressure liquid chromatography assay for cefepime in plasma, we observed significant drug degradation at 20 and 37°C but not at 4°C. This plasma-related degradation persisted after protein removal. This warrants caution regarding cefepime assays for pharmacokinetic and pharmacodynamic studies of cefepime in vitro and in vivo.

Enhanced Detectability and Chromatography of Some Amines by High Pressure Liquid Chromatography

1980 ◽  
Vol 63 (4) ◽  
pp. 702-706
Author(s):  
F Taylor Noggle
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Secondary Amines ◽  
High Pressure Liquid Chromatographic ◽  
Ultraviolet Detection ◽  
Primary And Secondary Amines ◽  
Liquid Chromatographic ◽  
Derivatives Of

Abstract The high pressure liquid chromatographic properties of 13 phenylisothiocyanate derivatives of primary and secondary amines were examined with ultraviolet detection at 254 nm. Urine extracts of subjects who were taking ephedrine, phenylpropanolamine, and phentermine were also examined. The method described improves the chromatographic properties of the amines and also enhances their detectability.

Detection of Low-Level Carbadox Residues in Animal Feeds by High Pressure Liquid Chromatography

1977 ◽  
Vol 60 (2) ◽  
pp. 279-283
Author(s):  
Ronald G Luchtefeld
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
False Positive ◽  
Active Drug ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Low Level ◽  
Liquid Chromatographic ◽  
Positive Results

Abstract The high pressure liquid chromatographic (HPLC) method is capable of detecting from 1 to 0.024 ppm methyl 3-(2-quinoxalinyl-methylene) carhazate-Nl,N4-dioxido (carbadox). Carbadox is extracted from the feed with 2% NH4OH in acetone, passed through a liquid-liquid partition, subjected to HPLC, and detected by using a 365 nm detector. No feed materials or other active drug ingredients produced false positive results.

High-Pressure Liquid Chromatography of Benzo (a) pyrene and Benzo(ghi)perylene in Oil-Contaminated Shellfish

1976 ◽  
Vol 59 (5) ◽  
pp. 989-992 ◽  
Author(s):  
Humberto Guerrero ◽  
Edward R Biehl ◽  
Charles T Kenner
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Petroleum Ether ◽  
Silica Gel ◽  
High Pressure Liquid Chromatography ◽  
High Pressure Liquid Chromatographic ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic ◽  
Polynuclear Aromatics

Abstract A high-pressure liquid chromatographic procedure is described for the determination of benzo (a) pyrene and benzo(ghi)perylene. These polynuclear aromatics are extracted with acetonitrile and partitioned into petroleum ether, the petroleum ether is removed, and the residue is saponified. The compounds are purified and isolated by passing the residue through a silica gel column and a high-pressure liquid chromatographic column, and detected by their ultraviolet absorption. Recoveries of standards through the procedure averaged 104%.

High Pressure Liquid Chromatographic Determination of Vitamin D3 in Mineral Feed Premixes

1980 ◽  
Vol 63 (5) ◽  
pp. 1149-1153
Author(s):  
Dennis G Lein ◽  
Harold M Campbell ◽  
Huguette Cohen
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Vitamin D3 ◽  
Ammonium Hydroxide ◽  
Chromatographic Determination ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Better Than

Abstract A simple and rapid quantitative method is described for determining the presence and amount of vitamin D3 (cholecalciferol) in mineral feed premixes by high pressure liquid chromatography. The samples were extracted with dichloromethane–pentane–methanol (46+46+8) after treatment with ammonium hydroxide, cleaned up by silica Sep-pak, and analyzed by normal phase high pressure liquid chromatography: 10 μm LiChrosorb NH2 column, hexane-isopropanol (98+2) mobile phase, ultraviolet detection at 254 nm. Recoveries were better than 95% in the range 25 000–100 000 IU/kg.

scholarly journals An accurate and sensitive analysis by high-pressure liquid chromatography of conjugated and unconjugated bilirubin IX-α in various biological fluids

1980 ◽  
Vol 185 (1) ◽  
pp. 281-284 ◽  
Author(s):  
S Onishi ◽  
S Itoh ◽  
N Kawade ◽  
K Isobe ◽  
S Sugiyama
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Glucuronic Acid ◽  
Biological Fluids ◽  
Reversed Phase ◽  
Complete Separation ◽  
Bile Pigments ◽  
Human Bile ◽  
Neonatal Liver

An accurate and sensitive method was developed for the complete separation of the native tetrapyrroles, such as bilirubin and its mono- and di-conjugates of glucuronic acid, glucose and xylose, by ion-pair reversed-phase high-pressure liquid chromatography. The application of this method was demonstrated by the analysis of bile pigments in human bile and urine, and the method also makes it possible to estimate very low UDP-glucuronyltransferase activity, such as is found in the human foetal and neonatal liver.

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