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Serum Thyroxine (serum + thyroxine)
Selected AbstractsThe Evaluation of Thyroid Functions, Thyroid Antibodies, and Thyroid Volumes in Children with Epilepsy during Short-Term Administration of Oxcarbazepine and ValproateEPILEPSIA, Issue 11 2006Ali Cansu Summary:,Purpose: The aim of this study was to evaluate the effects of short-term oxcarbazepine (OXC) and valproate (VPA) monotherapy on thyroid functions in children. Methods: Fifty-five newly diagnosed epileptic children with normal thyroid functions (confirmed with the thyrotropin releasing hormone stimulation test) participated in this study. VPA treatment was started in 30 patients and OXC in 25 patients. Serum thyroxine (T4), free thyroxine (fT4), triiodothyronine (T3), free triiodothyronine (fT3), reverse T3 (rT3), thyroid peroxidase antibodies (TPO-ab), and urine iodine levels were evaluated at baseline and at the third and sixth months of therapy. Results: In the OXC group, serum T4, fT4, T3, fT3, and rT3 levels were found to be decreased at the third and sixth months, the differences were significant compared to the baseline values except for fT3 levels at the third month and fT4 and rT3 levels at the sixth month (p < 0.05). At the sixth month, serum T4 level dropped below the normal reference value in 8 (32%), fT4 in 5 (20%), T3 in 4 (16%), and fT3 in 3 (12%) patients. In the VPA group, mean T4, fT4, T3, fT3, and rT3 levels at 3 and 6 months remained similar compared to the baseline values (p > 0.05). Mean serum thyroid stimulating hormone levels increased significantly at the sixth month compared to the baseline values in the VPA group (p < 0.05) while it remained unchanged in the OXC group (p > 0.05). There was no effect of either drug on urinary iodine excretion and serum TPO-ab levels remained in normal ranges throughout the study. Conclusions: In this prospective study, it is documented that children under short-term OXC or VPA therapy showed altered thyroid functions similar to the changes observed after long-term treatment. Although, the clinical significance of these results need to be evaluated with future studies, this observation of altered thyroid functions points out that thyroid functions may need to be monitored closely in children receiving antiepileptic treatment, even in the short-time interval. [source] Gastric emptying function changes in patients with thyroid cancer after withdrawal of thyroid hormone therapyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2004PAN-FU KAO Abstract Background:, Hypothyroidism is commonly thought to cause decreased gastric emptying but is mostly associated with autoimmune disease. In the present study the gastric emptying function of thyroid cancer patients with severe hypothyroidism of short duration was evaluated with a radionuclide solid meal gastric emptying study. Methods:, Twenty-two patients who had undergone surgical operation and 131I ablation for thyroid cancer participated in solid meal gastric emptying studies before the withdrawal of thyroxine and then again 4 weeks after the withdrawal of thyroxine. Eleven patients had an additional gastric emptying study at 6 weeks after withdrawal of thyroxine. Gastric emptying curves and emptying parameters were calculated. Student's paired t -test was used for statistical analysis of data for all cases between the baseline and at 4 weeks after withdrawal. An additional repeated measure anova with multiple comparisons was performed on data between baseline, 4 weeks and 6 weeks after withdrawal for the other 11 patients. All P values presented are two-tailed and the significance level is 0.05. Results:, Hypothyroidism status was confirmed by the marked change of the serum thyroxine and thyroid-stimulating hormone 4 weeks and 6 weeks after withdrawal of the thyroxine replacement (P < 0.001). The gastric half-emptying time and emptying rate changed significantly after short-term severe thyroid hormone deficiency (P < 0.005). However, the length of the lag phase did not have a statistically significant change at 4 weeks or 6 weeks after withdrawal of the thyroxin replacement (P = 0.219 and 0.142). Conclusions:, Hypothyroidism following the withdrawal of the thyroxine replacement in thyroid cancer patients preparing for 131I cancer work-up can significantly prolong gastric half-emptying time and emptying rate. [source] Influence of Isoflurane General Anesthesia or Anesthesia and Surgery on Thyroid Function Tests in DogsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2009M.A. Wood Background: Anesthesia and surgery affect thyroid function tests in humans but have not been studied in dogs. Hypothesis: Anesthesia and anesthesia with surgery will affect thyroid function tests in dogs. Animals: Fifteen euthyroid dogs. Methods: Prospective, controlled, interventional study. Dogs were assigned to one of 3 groups: control, general anesthesia, and general anesthesia plus abdominal exploratory surgery. Dogs in the anesthesia and surgery groups were premedicated with acepromazine and morphine, induced with propofol, and maintained on isoflurane. Samples for measurement of serum thyroxine (T4), free T4 (fT4) by equilibrium dialysis, triiodothyronine (T3), reverse T3 (rT3), and thyroid-stimulating hormone concentrations were collected from each dog immediately before premedication, at multiple times during anesthesia, surgery, 4, 8, 12, 24, 36, and 48 hours after anesthesia, once daily for an additional 5 days, and once 14 days after anesthesia. Sampling was performed at identical times in the control group. Results: Serum T4 decreased significantly from baseline in the surgery and anesthesia groups compared with the control group at 0.33 (P= 0.043) and 1 hour (P= 0.018), and 2 (P= 0.031) and 4 hours (P= 0.037), respectively, then increased significantly in the surgery group compared with the control group at 24 hours (P= 0.005). Serum T3 decreased significantly from baseline in the anesthesia group compared with the control group at 1 hour (P= 0.034). Serum rT3 increased significantly from baseline in the surgery group compared with the control and anesthesia groups at 8 (P= 0.026) and 24 hours (P= 0.0001) and anesthesia group at 8, 12, 24, and 36 hours (P= 0.004, P= 0.016, P= 0.004, and P= 0.014, respectively). Serum fT4 increased significantly from baseline in the surgery group compared to the control at 24 hours (P= 0.006) and at day 7 (P= 0.037) and anesthesia group at 48 hours (P= 0.023). Conclusions and Clinical Importance: Surgery and anesthesia have a significant effect on thyroid function tests in dogs. [source] Comparison of Serum-Free Thyroxine Concentrations Determined by Standard Equilibrium Dialysis, Modified Equilibrium Dialysis, and 5 Radioimmunoassays in DogsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2004Sara Schachter Measurement of serum-free thyroxine (fT4) concentration provides a more accurate assessment of thyroid gland function than serum thyroxine (T4) or 3,5,3'-triiodothyronine (T3). Techniques for measuring serum fT4 concentration include standard equilibrium dialysis (SED), radioimmunoassay (RIA), and a combination of both (modified equilibrium dialysis [MED]). This study compared results of serum fT4 measurements by means of SED, MED, and 5 RIAs in 30 healthy dogs, 10 dogs with hypothyroidism, and 31 euthyroid dogs with concurrent illness for which hypothyroidism was a diagnostic consideration. Serum fT4 concentrations were comparable when determined by the SED and MED techniques, and mean serum fT4 concentrations were significantly (P<.01) lower in dogs with hypothyroidism than in healthy dogs and euthyroid dogs with concurrent illness. Significant (P < .05) differences in fT4 concentrations were identified among the 5 RIAs and among the RIAs and MED and SED. Serum fT4 concentrations were consistently lower when fT4 was determined by the RIAs, compared with either equilibrium dialysis technique. Serum fT4 concentrations were significantly lower (P < .01) in dogs with hypothyroidism than in healthy dogs for all RIAs; were significantly lower (P < .05) in dogs with hypothyroidism than in euthyroid dogs with concurrent illness for 4 RIAs; and were significantly lower (P < .01) in euthyroid dogs with concurrent illness than in healthy dogs for 4 RIAs. RIAs had the highest number of low serum fT4 concentrations in euthyroid dogs with concurrent illness. This study documented differences in test results among fT4 assays, emphasizing the importance of maintaining consistency in the assay used to measure serum fT4 concentrations in the clinical or research setting. [source] Thyrotropin-Releasing Hormone Stimulation Test to Assess Thyroid Function in Severely Sick CatsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2001Kamil Tomsa Basal serum thyroxine (T4) concentration and the thyrotropin-releasing hormone (TRH) stimulation test were used to assess thyroid function in 36 critically ill cats examined between July 1996 and October 1998. Of the 36 cats, hyperthyroidism (as underlying or complicating disease) was suspected in 22 based on clinical signs, palpable thyroid nodules, and abnormal thyroid gland histology (study group). Hyperthyroidism was not suspected in the remaining 14 cats, which served as the control group. Based on serum T4 concentrations, suppression of thyroid function was documented in 14 (64%) cats of the study group and in 10 (71%) cats of the control group. The TRH stimulation test revealed an increase in serum T4 of less than 50% of the baseline concentration in 18 (82%) cats of the study group, and in 6 (43%) cats of the control group. In conclusion, based on the results of serum T4 determinations and the TRH stimulation tests, it was not possible to differentiate between cats with clinical and histologic evidence of thyroid dysfunction (hyperthyroidism) and cats with severe nonthyroidal illnesses. [source] | ||||||||||