Search results for "Thyroxine"
showing 10 items of 61 documents
Effect of Thyroid Hormones on Urea Biosynthesis and Related Processes in Rat Liver*
1988
The results of the few studies on the effect of the thyroid status on nitrogen metabolism have been inconclusive and/or contradictory. In an attempt to elucidate this important relationship, we have studied the effect of experimental hypo- and hyperthyroidism on urea biosynthesis and related processes. We have found that the capacity of the liver to synthesize urea was increased in hypothyroid rats, as were the activities of the urea cycle enzymes; there were also changes in the activities of some related enzymes and in the levels of intermediates and amino acids. Isolated hepatocytes from these rats showed an increased capacity for urea synthesis. In hyperthyroid rats the picture was more …
A Novel Deletion in the Thyrotropin Beta-Subunit Gene Identified by Array Comparative Genomic Hybridization Analysis Causes Central Congenital Hypoth…
2014
<b><i>Background:</i></b> Isolated central congenital hypothyroidism (ICCH) is rare but important. Most ICCH patients are diagnosed later, which results in severe growth failure and intellectual disability. <b><i>Objective:</i></b> We describe a boy with ICCH due to a large homozygous <i>TSHβ </i>gene deletion. <b><i>Results:</i></b> A 51-day-old male Turkish infant, whose parents were first cousins, was admitted for evaluation of prolonged jaundice. His clinical appearance was compatible with hypothyroidism. Venous thyrotropin (TSH) was undetectably low, with a subsequent low free T4 and a low free T3, sugg…
Abnormal thyroid hormones and non-thyroidal illness syndrome in obstructive sleep apnea, and effects of CPAP treatment
2016
Objective In obstructive sleep apnea (OSA), while both hypothyroidism and hyperthyroidism have been studied, the occurrence of non-thyroidal illness syndrome (NTIS) (normal thyroid stimulating hormone [TSH] with low triiodotironine) has not been investigated. We explored the occurrence of NTIS in patients with moderate to severe OSA and its relationship to the severity of nocturnal respiratory disorders. We also studied the occurrence of subclinical hypothyroidism (SH, ie, high TSH with normal thyroxine) in OSA and changes in circulating TSH, free triiodotironine (fT3) and free thyroxine (fT4) after CPAP treatment. Methods After a nocturnal respiratory polysomnography, 125 consecutive patie…
Plasma levels of lipoproteins and apolipoproteins in congenital hypothyroidism: Effects of l-thyroxine substitution therapy
1995
Thyroid status in humans is an important factor in the regulation of lipoprotein metabolism. There are several data on hypothyroidism in the adult population, but less information is available about congenital hypothyroidism. Since lipid metabolism at birth is substantially different from that of adults, it is not likely that the same abnormalities that occur in adult hypothyroidism are also present when this is diagnosed at early life. We studied 16 subjects with congenital hypothyroidism, seven at the time of diagnosis and also after normalization of thyroid hormone levels over a period of 2.0 +/- 1.0 months of substitution therapy with L-thyroxine (5.9 +/- 1.2 micrograms/kg/d) and nine a…
Relapses of hyperthyroidism in patients treated with radioiodine for nodular toxic goiter: relation to thyroid autoimmunity.
2003
Relapses of hyperthyroidism after treatment with radioiodine for uni- or multi-nodular goiter may be accompanied by the appearance of TSAb. However, this phenomenon has only emerged from one retrospective study on Northern European patients, in which it was not possible to determine whether TSAb also appeared in treated patients who did not relapse. The present study aimed to assess the appearance, immunogenic nature and clinical characteristics of hyperthyroidism relapse after treatment with 131I for nodular toxic goiter in patients from the Mediterranean area. A retrospective study was performed on 76 consecutive patients, born and resident in Sicily and aged 56-80 yr at diagnosis, who we…
Congenital hypothyroidism in a child with unsuspected familial dysalbuminemic hyperthyroxinemia caused by a mutation (R218H) in the human albumin gene
2001
We found familial dysalbuminemic hyperthyroxinemia (FDH) in a 5-month-old boy with congenital hypothyroidism (CH) who had a blood thyrotropin (TSH) level of 479 mU/L but normal total serum thyroxine (T4) and higher than normal total triiodothyronine (T3) levels. Thyroid hormone substitution began at 5 weeks of age when T4 and T3 concentrations were below normal. Until the age of 5 months, treatment with levothyroxine was suboptimal on the basis of high serum TSH levels despite above-normal T4 levels. FDH was confirmed by isoelectric focusing and testing of other family members. DNA analysis of the patient revealed R218H, a mutation in the serum albumin gene associated with FDH, which was al…
A new heterozygous mutation (L338N) in the human Gsalpha (GNAS1) gene as a cause for congenital hypothyroidism in Albright's hereditary osteodystroph…
2003
OBJECTIVE: To identify the molecular defect by which psychomotor retardation is caused in two brothers with congenital hypothyroidism who received adequate treatment with l-thyroxine. CASE REPORT: A six-year-old boy presented with psychomotor retardation and congenital primary hypothyroidism (CH). The patient had a normal blood thyrotrophin (TSH) level on neonatal screening, but low total serum thyroxine and triiodothyronine concentrations prompting thyroid hormone substitution shortly after birth. Nevertheless, psychomotor development was retarded and the patient underwent further investigation. Typical features of Albright's hereditary osteodystrophy (AHO) such as round face, obesity, and…
Differential effect of hypophysectomy and growth hormone treatment on hepatic glucuronosyltransferases in male rats: Evidence for an action at a pret…
1997
International audience; The influence of growth hormone (GH) on 4-nitrophenol, bilirubin, testosterone, androsterone and estrone glucuronidation activities was studied in fully activated male rat hepatic microsomes. Sham-operated and hypophysectomized animals were injected with two different dosages of GH, mimicking either the male or female GH secretion pattern. Half the animals received thyroxine and cortisol in concentrations chosen to compensate for the lack of thyroid hormones and glucocorticoids in hypophysectomized rats. GH induced a decrease in several glucuronidation activities: bilirubin glucuronidation in both sham-operated and cortisol/ thyroxine-treated hypophysectomized rats i…
Effect of L-thyroxine on renal excretion of water and electrolytes in both normal and mercury-intoxicated rats.
1980
The urine output and the change in excretion of electrolytes (sodium, potassium, calcium, chloride, inorganic phosphate) in rats following mercury-induced acute tubular lesions showed marked recovery during L-thyroxine therapy. The kidney mechanisms responsible for this effect are discussed, considering especially the observation that rats treated with L-thyroxine have a reduced urinary output, unlike other species, including man, which react with polyuria. The oliguric effect of thyroid hormone in rats is attributed to the greater length of the vasa recta and loops of Henle.
Risk factors for chronic thromboembolic pulmonary hypertension – Importance of thyroid disease and function
2019
Abstract Introduction Although a number of risk factors for chronic thromboembolic pulmonary hypertension (CTEPH) have been reported, the exact prevalence is controversial and varies between published cohorts. The aim of the present study was to investigate the prevalence of risk factors in operable CTEPH patients with special emphasis on thyroid disease and function. Material and methods Overall, 228 CTEPH patients (47.7% female; median age 63 [IQR 52–72] years) scheduled for pulmonary endarterectomy between 01/2014 and 12/2015 were studied. Prevalence of risk factors was assessed, and patients were classified according to their thyroid function based on laboratory measurements. Results As…