Oxygen flask combustion in determination of C14 and H3 in biological materials

Oliverio, Vincent T.; Denham, Charlene; Davidson, Jack D.

doi:10.1016/0003-2697(62)90035-0

Cited by 76 publications

(30 citation statements)

References 2 publications

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“…frozen, and stored under Dry Ice until returned to the laboratory. The radioactive samples were subsequently lyophilized and combusted in oxygen following a modified Schoniger technique (15). Radioactive gas assimilated by the stem tissue was measured by liquid scintillation counting.…”

Section: Methodsmentioning

confidence: 99%

Seasonal Patterns of Acid Metabolism and Gas Exchange in Opuntia basilaris

Szarek¹,

Ting²

1974

Plant Physiol.

116

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Acid metabolism and gas exchange studies were conducted in situ on the cactus Opuntia basilaris Engelm. and Bigel. A pattern of significant seasonal variation was evident. The pattern was controlled by rainfall, which significantly influenced plant water potentials, total gas transfer resistances, and nocturnal organic acid synthesis. In winter and early spring, when plant water stress was mild, stomatal and mesophyll resistances remained low, permitting enhanced nocturnal assimilation of "CO2. The day/night accumulation of acidity was large during these seasons. In summer and fall, plant water stress was moderate, although soil water stress was severe. The nocturnal assimilation of "CO2 was very low during these seasons, even in stems with open stomata, indicating large mesophyll resistances restricting exogenous gas incorporation. The day night accumulation of acidity was reduced, and a low level of acid metabolism persisted throughout this period. The rapid response to a midsummer rainfall emphasizes the importance of plant water potential as a parameter controlling over-all metabolic activity. The seasonal variations of acid metabolism and gas exchange significantly influenced the efficiency of water use and carbon dioxide assimilation. Periods of maximal efficiency followed rainfall throughout the course of the year.Historically, succulents have been considered a group of plants with morphological and anatomical similarities, and recently this classification has been expanded to include physiological similarities (7,16

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Section: Methodsmentioning

confidence: 99%

Seasonal Patterns of Acid Metabolism and Gas Exchange in Opuntia basilaris

Szarek¹,

Ting²

1974

Plant Physiol.

116

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“…Carrier hemoglobin was added to the radioactive hemoglobin solution to yield a total of 200 mg, and the hemin (32) and twice recrystallized (33). One mg hemin-4C was weighed on a Cahn electrobalance, combusted to U4CO (34), and the specific activity determined in a Packard Tri-Carb liquid scintillation spectrometer. The specific activity of the original hemoglobin heme was calculated by correcting for the added carrier hemoglobin.…”

Section: Long-term Studies In Gunn Ratsmentioning

confidence: 99%

The sources of bile pigment in the rat: studies of the "early labeled" fraction.

Robinson¹,

Tsong²,

Brown³

et al. 1966

J. Clin. Invest.

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“…After the biosynthesis of bilirubin-14C by Ostrow, Hammaker, and Schmid in 1961 (1), this material was used to determine the plasma clearance patterns and bilirubin turnover rates in children with Crigler-Najjar synReceived for publication 13 drome (2)(3)(4) and congenital biliary atresia (5). In these unique situations, the existence of a very large whole body bilirubin pool with a slow turnover rate permitted the use of labeled bilirubin of low specific activity, and of relatively simple methods of data analysis.…”

Section: Introductionmentioning

confidence: 99%

“…Feces and urine were collected in 24-hr blocks for 7 days after injection of bilirubin-4C. The total carbon-14 content of each 24-hr stool collection was determined as described by Crigler and Gold (4), using an oxygen flask combustion method (13). No attempt was made to crystallize bilirubin-14C or stercobilin-14C from the feces.…”

mentioning

confidence: 99%

Studies of bilirubin kinetics in normal adults

Berk¹,

Howe²,

Bloomer³

et al. 1969

J. Clin. Invest.

222

132

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A B S T R A C T This report describes studies of bilirubin kinetics in 13 healthy young adults. The plasma content of unconjugated bilirubin-14C was determined at frequent intervals for 24-30 hr after the intravenous injection of a tracer dose of unconjugated isotopic bilirubin. Fecal and urinary radioactivity were measured for 7 days. During this time cumulative recovery averaged 96% of the injected dose. The plasma curves were processed by digital computer. For the 30 hr experimental period, a sum of three exponentials, with average half-times of 18, 81, and 578 min, was required to describe the data. Using the plasma curve integral method, the hepatic bilirubin clearance (47 +10 ml/min, mean +SD), the bilirubin production rate (3.8 ±0.6 mg/kg per day), and the mean red blood cell life span (101 ±13 days) were calculated directly from the parameters of this function. To gain further insight into the metabolism of unconjugated bilirubin, the data were also used to determine the parameters of a multicompartmental model. In the model proposed, plasma unconjugated bilirubin exchanges with two additional pools, one of which is thought to represent extrahepatic extravascular, and the other intrahepatic unconjugated bilirubin. Bilirubin is eliminated from the system via the proposed intrahepatic pool. From the data and the model, pool sizes and exchange rates between compartments were calculated, and the liver: plasma concentration gradient estimated. These studies provide a detailed analysis of the kinetics of unconjugated bilirubin in a healthy normal population and are intended to serve as a reference point for studies of abnormal states.

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Oxygen flask combustion in determination of C14 and H3 in biological materials

Cited by 76 publications

References 2 publications

Seasonal Patterns of Acid Metabolism and Gas Exchange in Opuntia basilaris

Seasonal Patterns of Acid Metabolism and Gas Exchange in Opuntia basilaris

The sources of bile pigment in the rat: studies of the "early labeled" fraction.

Studies of bilirubin kinetics in normal adults

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