[Isolation and characterization of beef thyroid giant RNA]. / Isolement et caractérisation des RNA géants de la glande thyroide de boeuf.

Total HMW-RNAs were prepared by three different methods (method with phenol, method with NaClO4, method without phenol using Ultrogel AcA 22 filtration). Giant RNAs were obtained in the void volume by filtration on Sepharose 2B. The giant RNAs/total HMW-RNA ratio is higher (6.77%) with the gel filtration method than with phenol or NaClO4 methods (1.41% and 1.00% respectively). The nucleotide composition of these RNAs is DNA-like and the sedimentation constants are approximately 70-100 S.

[Rapid technic for preparation of thyroid ribonucleic acids without phenol]. / Technique rapide de preparation des acides ribonucleiques thyroidiens sans phenol.

Thyroid tissue was homogenized in 2 M LiCl. The homogenate was alloued to stand 1 h 30 min at 2 degrees C and then centrifuged. The pellet was suspended in 5% triisopropylnaphthalene sulfonic acid (the sodium salt), 0.05 M Tris--HCl, and 0.1 M NaCl (pH 8). After stirring and centrifuging, the supernatant containing the crude RNA was purified by filtration on Ultrogel AcA 22 (LKB, Sweden). Before adding the sample of crude RNA to the column, pronase was placed on the column. When pronase had entered the gel, we added the sample. The first peak contained pure RNA plus some DNA. The former was precipitated with 2 M LiCl. The RNA species obtained by this technique were undegraded and the yield was 30% better than that of the phenol technique.

Ribosomal and transfer RNA contents of the normal and pathologic human thyroid gland.

One hundred and seventy seven pieces of normal or pathologic thyroid tissue from 17 patients were assayed for rRNA, tRNA and DNA content. The tRNA/DNA and rRNA/DNA ratios in pathologic tissue were statistically compared with the same ratios in normal tissue. In toxic adenoma (5 cases) and anoplastic cancer (2 cases), both ratios were increased. In cold nodules (9 cases), there was in increase of the tRNA/DNA ratio only in 1 case, of the rRNA/DNA ratio only in 4 cases, and of both ratios in 3 cases. In one case of a cold nodule in a Basedow's disease gland, there was no modification of these ratios. In Basedow's disease (3 cases), there was an increase of rRNA/DNA ratio only in one case.

[Radioimmunoassay without extraction of L-triiodothyronine in human serum]. / Dosage radioimmunologique sans extraction de la L-triidothyronine dans le sérum humain

A radio-immunoassay of L-triiodothyronin is described. Blinding of T3 to TBG is prevented by salicylate (1%--w/v). The rabbit antiserum obtained by injection of a complexe T3-bovine serum albumin is diluted between 1/10000 and 1/20000. Bound and free hormone are separated by polyethylene glycol (17%--w/v). Serum T3-concentration in normal subjects averaged 132 +/- 29 ng/dl (SD). In hyperthyroid and hypothyroid patients, these values were respectively 351 +/- 118 ng/dl and 68 +/- 21 ng/dl.