Specific Activities of the UTP Pools of Human Lymphocytes After Uridine-3H Labeling

1973 ◽  
Vol 51 (6) ◽  
pp. 954-957 ◽  
Author(s):  
T. Fields ◽  
L. Brox
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Rna Synthesis ◽  
Specific Activity ◽  
Human Lymphocytes ◽  
Direct Measure ◽  
Specific Activities ◽  
The Relationship

Human lymphocytes were labeled in vitro under various conditions with uridine-5-3H, and the specific activities of the acid-soluble UTP pools were determined by high-pressure liquid chromatography. Essentially, all the acid-soluble counts were in either UTP- or UDP-glucose. The relationship between the intracellular UTP specific activity, the extracellular uridine concentration, and the time of labeling demonstrates that the incorporation of uridine cannot be taken as a direct measure of RNA synthesis in these cells.

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 A tryptophan C-methyltransferase involved in streptonigrin biosynthesis in Streptomyces flocculus

1984 ◽  
Vol 220 (1) ◽  
pp. 309-313 ◽  
Author(s):  
D L Hartley ◽  
M K Speedie
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Amino Acid ◽  
Stationary Phase ◽  
High Pressure Liquid Chromatography ◽  
Absolute Configuration ◽  
Specific Activity ◽  
Shake Culture ◽  
Methyl Group ◽  
The Absolute

A C-methyltransferase that catalyses the transfer of a methyl group from S-adenosylmethionine to C-3 of tryptophan, resulting in beta-methyltryptophan, has been identified in cell-free extracts of streptonigrin-producing Streptomyces flocculus. The absolute configuration of the product was shown to be (2S,3R)-beta-methyltryptophan by high-pressure liquid chromatography and reactivity with D- and L-amino acid oxidases. In shake culture, maximum specific activity occurs after S. flocculus enters stationary phase, but before significant streptonigrin accumulates.

THE RELATIONSHIP BETWEEN CORTICOSTERONE SYNTHESIS FROM ENDOGENOUS PRECURSORS AND FROM ADDED RADIOACTIVE PRECURSORS BY RAT ADRENAL TISSUE IN VITRO

1966 ◽  
Vol 36 (3) ◽  
pp. 231-238 ◽  
Author(s):  
G. P. VINSON
Keyword(s):  
Specific Activity ◽  
Single Point ◽  
Biosynthetic Pathways ◽  
Activity Change ◽  
Adrenal Tissue ◽  
Specific Activities ◽  
The Relationship ◽  
Synthesis Of Hormones ◽  
Venous Plasma

SUMMARY A kinetic study of corticosterone recovered during incubation of rat adrenal tissue with [4-14C]progesterone and [16-3H]pregnenolone shows that both its 3H: 14C ratio and its specific activity change with time throughout incubation. Corticosterone is itself metabolized, and hypotheses based on the rate of production of corticosterone may be therefore deceptive when the amount is measured at a single point in time. Thus disparities between the specific activities of products and intermediates may be expected which alone do not necessarily indicate differences between the biosynthetic pathways involved in production from endogenous precursors and those from added radioactive precursors. Other experiments suggest that steroids in incubation media, in concentrations comparable with those found in adrenal venous plasma, do not inhibit the continued synthesis of hormones.

Mechanism of Development of Bronze Baby Syndrome in Neonates Treated with Phototherapy

PEDIATRICS ◽  
1982 ◽  
Vol 69 (3) ◽  
pp. 273-276
Author(s):  
Shoju Onishi ◽  
Susumu Itoh ◽  
Kenichi Isobe ◽  
Hajime Togari ◽  
Hideyuki Kitoh ◽  
...  
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Radical Reaction ◽  
The Body ◽  
Brown Pigment ◽  
Free Radical Reaction ◽  
Serum Concentrations ◽  
Excretory Function

Comparisons of serum concentrations of unknown pigment and photobiirubin IXα, the two main bilirubin photoproducts, were made during phototherapy in infants with and without bronze baby syndrome who were treated similarly. The serum concentrations of unknown pigment estimated by high-pressure liquid chromatography in infants with the bronze baby syndrome were significantly increased in comparison with those in the control hyperbilirubinemic neonates during phototherapy. However, there was no difference in the serum concentrations of photobilirubin IXα between infants with bronze baby syndrome and the control groups. The unknown pigment separated from bilirubin photoproducts obtained from experiments in vitro by high-pressure liquid chromatography was gradually decomposed into brown products that showed the absorption spectrum similar to that of the serum of infants with bronze baby syndrome. This fact is probably due to reduction in hepatic excretory function of bilirubin photoproducts, especially unknown pigment, because its main excretory pathway is the biliary route. The pigment accumulated in the body may be polymerized and forms bilifuscin-like substances following a free radical reaction. It is concluded that the brown pigment is formed via unknown pigment.

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.

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.

The Effects on Neonatal Hyperbilirubinaemia of Parenteral Administration of Valium to Women in Labour

1978 ◽  
Vol 6 (6) ◽  
pp. 468-470 ◽  
Author(s):  
R Stockmann ◽  
D Sidiropoulos ◽  
G Wendt
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Cord Blood ◽  
High Pressure Liquid Chromatography ◽  
Sodium Benzoate ◽  
Newborn Infants ◽  
Parenteral Administration ◽  
Intramuscular Administration ◽  
Therapeutic Doses

Following intramuscular administration of Valium® Roche to the mother during labour, the concentration of sodium benzoate (included in the solvent of Valium) was measured in the cord-blood of 8 newborn infants. After administration of therapeutic doses of Valium to the mother, it was found that sodium benzoate—which displaces bilirubin from albumin in vitro— was present in the cord blood in concentrations insufficient to cause clinically important displacement of bilirubin from albumin. Benzoate analyses were carried out using high-pressure liquid chromatography.

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