CONTEXT Thyroidal production of triiodothyronine (T3) is absent in athyreotic patients, leading to the suggestion that T3 deficiency may be unavoidable during levothyroxine (LT4) therapy. However, trials evaluating therapy with combined LT4 and T3 have failed to demonstrate any consistent advantage of combination therapy. OBJECTIVE To determine whether T3 levels in patients treated with LT4 t...

The objective of this study was to determine the feasibility of using airborne T3 coliphage as a viral tracer in microbial aerosols. Although T3 coliphage was relatively stable when stored either at temperatures ranging from 21 to 37 C or in the frozen state at -20 C, there was a 2-log loss in infectivity when stored for 72 days at 4 C. Either agitation of stored coliphage suspensions held at 3...

In Xenopus, termination by RNA polymerase I (pol I) is mediated by the 9 bp sequence GACTTGCNC and RNA 3'-ends are formed -15-20 nt upstream of this terminator element. Here I show that this 9 bp element, also called the 'T3 box', is a pause signal for the elongating transcription complex. The two major transcripts in the paused complex have 3'-ends mapping to 15 and 21 nt upstream of the T3 bo...

AIM To compare the efficacy of manual and oscillating-rotating electric toothbrushes in removing plaque and reducing gingivitis in patients with fixed orthodontic appliances. STUDY DESIGN Randomised clinical trial. MATERIALS AND METHODS 20 subjects aged 10 to 14 years (8 males; 12 females) scheduled for fixed orthodontic treatment were enrolled, randomly divided into two groups, A and B, an...

The response to an intravenous dose of 200 microng of thyrotrophin releasing hormone (TRH) has been studied by estimating, by radioimmunoassay, baseline levels followed by further estimations of thyroid stimulating hormone (TSH) 20 minutes after the injection and triiodothyronine (T3) three hours after the injection in 112 patients referred for routine thyroid assessment. Comparison of diagnost...

2-n-Butyl-3-(4'-diethylaminoethoxy-3',5'-diiodobenzoyl)-benzofurane (amiodarone), a drug used in arrythmias and angina pectoris, contains 75 mg of organic iodine/200 mg active substance. Four studies were performed to test its effect on thyroid hormone metabolism: (a) nine male subjects were treated with 400 mg of amiodarone for 28 days; (b) five male subjects received, for the same period of t...

Although the normal thyroid gland secretes both levothyroxine (L-T4) and levotriiodothyronine (L-T3), normalization of serum TSH with L-T4-replacement therapy alone in hypothyroidism is generally believed to result in a normal serum L-T3 and to reflect a euthyroid state. However several recent studies suggest that this may not be the case. Accordingly, the relationship between serum free L-T4 a...

Ornithine aminotransferase, a mitochondrial matrix enzyme, is expressed constitutively in many mammalian tissues and is subject to complex hormonal and dietary regulation in rat liver and kidney. The kidney enzyme is induced by estrogen and thyroid hormone (3,3',5-triiodo-L-thyronine, T3). We demonstrated previously that the hormonal induction in kidney is the result of an increase in ornithine...

The serum concentrations of tri-iodothyronine (T3), thyroxine (T4), and thyrotrophin (TSH) were measured in 10 term newborn infants between birth and the age of 2 days by radioimmunoassay. The mean concentration of T3 in maternal serum was 1.62 mug/l, and it increased from the low cord blood level of 0-63 mug/l to the peak value of 1-76 mug/l within the first 2 hours of life. Mean serum T4 conc...

To investigate the effect of thyroid hormone on the proliferative activity and apoptosis of granulosa cells at the varying stages of follicular growth, porcine granulosa cells obtained from small (1-2 mm), medium (3-5 mm) and large (6-11 mm) follicles were cultured under a serum-free condition in the presence or absence of follicle stimulating hormone (FSH; 20 ng/ml), with or without triiodothy...