Comparison of the &lt;i&gt;in vitro&lt;/i&gt; I 131 Triiodothyronine Resin Uptake Test and the Protein Bound Iodine in the Parturient and in the Newborn Infant (Cord Blood)

Evans, N. A.

doi:10.1159/000240022

Cited by 1 publication

(1 citation statement)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…T3 resin uptake test, however, measures the saturation of thyroid activity. Evans (1966) found in normal newborn infants mean cord blood PBI of 7 5 ,ug./100 ml., and 81% for the T3 resin uptake test.…”

Section: Resultsmentioning

confidence: 84%

Thyroid Function Tests in the Newborn

Chadd¹,

Gray²,

Davies³

1970

Archives of Disease in Childhood

View full text Add to dashboard Cite

. (1970). Archives of Disease in Childhood, 45, 374. Thyroid function tests in the newborn. The 131I triiodothyronine (T3) resin uptake test reflects thyroid function more closely than other acceptable tests currently available.The T3 uptake and protein-bound iodine (PBI) level were estimated in 20 premature and 20 full-term infants at birth and at the end of 1 week.The full-term infant has normal adult values, whereas the premature baby has results extending into the hyperthyroid range at birth, but these fall to within normal limits at 1 week.There are few studies of thyroid function in the newborn and neonatal period of infants bom earlier than the 37th week of gestation. Proteinbound iodine (PBI) levels are similar to those obtained for full-term infants (Danowski et al., 1950). The radioactive iodine (1311) uptake test has limited value because of the risk from irradiation.The in vitro test of radioactive 131I-labelled triiodothyronine uptake using red blood cells was introduced by Hamolsky, Stein, and Freedberg (1957). A similar test was used by later workers using a resin substituted for red blood cells (Nava and De Groot, 1962;Godden and Garnett, 1964 The tests were repeated on the 8th day of life. Plasma-bound iodine was estimated by Auto-analyser The 131I tri-iodothyronine (T,) resin uptake test was estimated after the method of Gimlette (1967). The T, adult euthyroid range is for this laboratory 70-140%.The T3 test can now be performed on as little as 0 1 ml. plasma. ResultsThe PBI levels in both the full-term and premature infants confirm the known high mean and wide ranges of cord blood, with even higher levels at the end of the first week (Table). However, T3 resin uptake is normal for the full-term infants both at birth and at the end of the first week. The premature infants' cord results show a high mean with a very wide range at birth, but by the end of the first week these results also show a normal mean and range.The mean cord blood PBI in both term and premature infants is at the upper limit of adult normal euthyroid values (3*5 fig.-8 0 tzg./100 ml.

show abstract

Section: Resultsmentioning

confidence: 84%