RESUMO
Background Dual-energy CT enterography (DECTE) has been shown to be useful in characterizing Crohn disease activity compared with clinical markers of inflammation but, to the knowledge of the authors, comparison has not been made with histopathologic specimens. Purpose To compare mucosal iodine density obtained at DECTE from Crohn disease-affected bowel with histopathologic specimens from surgically resected ileocolectomy bowel segments or terminal ileum colonoscopic biopsies in the same patients. Materials and Methods This was a retrospective study. Bowel segments in adults with Crohn disease who underwent DECTE from January 2017 to April 2019 within 90 days of ileocolectomy or colonoscopy were retrospectively evaluated with prototype software allowing the semiautomatic determination of inner hyperdense bowel wall (mucosal) mean iodine density, normalized to the aorta. Mean normalized iodine density and clinical activity indexes (Crohn Disease Activity Index [CDAI] and Harvey-Bradshaw Index [HBI]) were compared with histologic active inflammation grades by using two-tailed t tests. Receiver operating characteristic curves were generated for mean normalized iodine density, CDAI, and HBI to determine sensitivity, specificity, and accuracy. A P value less than .05 was considered to indicate statistical significance. Results The following 16 patients were evaluated (mean age, 41 years ± 14 [standard deviation]): 10 patients (five men, five women; mean age, 41 years ± 15) with 19 surgical resection specimens and six patients with terminal ileum colonoscopic mucosal biopsies (four men, two women; mean age, 43 years ± 14). Mean normalized iodine density was 16.5% ± 5.7 for bowel segments with no active inflammation (n = 8) and 34.7% ± 9.7 for segments with any active inflammation (n = 17; P < .001). A 20% mean normalized iodine density threshold had sensitivity, specificity, and accuracy of 17 of 17 (100%; 95% CI: 80.5, 100), six of eight (75%; 95% CI: 35, 97), and 23 of 25 (92%; 95% CI: 74, 99), respectively, for active inflammation. Clinical indexes were similar for patients with and without active inflammation at histopathologic analysis (CDAI score, 261 vs 251, respectively [P = .77]; HBI score, 7.8 vs 6.4, respectively [P = .36]). Conclusion Iodine density from dual-energy CT enterography may be used as a radiologic marker of Crohn disease activity as correlated with histopathologic analysis. © RSNA, 2021 See also the editorial by Ohliger in this issue.
Assuntos
Doença de Crohn/diagnóstico por imagem , Doença de Crohn/patologia , Inflamação/diagnóstico por imagem , Inflamação/patologia , Iodo/farmacocinética , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Biomarcadores , Meios de Contraste/farmacocinética , Doença de Crohn/complicações , Feminino , Humanos , Inflamação/etiologia , Intestinos/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Intensificação de Imagem Radiográfica/métodos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto JovemRESUMO
BACKGROUND: There is a concern regarding the use of iodinated contrast agents (ICA) for chest and neck computed tomography (CT) to localize metastatases in patients with differentiated thyroid cancer (DTC). This is because the iodine in ICA can compete with (131)I and interfere with subsequent whole scans or radioactive iodine treatment. The required period for patients to eliminate the excess iodine is not clear. Therefore, knowing the period for iodine levels to return to baseline after the injection of ICA would permit a more reliable indication of CT for DTC patients. The most widely used marker to assess the plasmatic iodine pool is the urinary iodine (UI) concentration, which can be collected over a period of 24 hours (24U) or as a single-spot urinary sample (sU). As 24U collections are more difficult to perform, sU samples are preferable. It has not been established, however, if the measurement of iodine in sU is accurate for situations of excess iodine. METHODS: We evaluated 25 patients with DTC who received ICA to perform chest or neck CT. They collected 24U and sU urinary samples before the CT scan and 1 week and 1, 2, and 3 months after the test. UI was quantified by a semiautomated colorimetric method. RESULTS: Baseline median UI levels were 21.8 µg/dL for 24U and 26 µg/dL for sU. One week after ICA, UI median levels were very high for all patients, 800 µg/dL. One month after ICA, however, UI median levels returned to baseline in all patients, 19.0 µg/dL for 24U and 20 µg/dL for sU. Although the values of median UI obtained from sU and 24U samples were signicantly different, we observed a significant correlation between samples collected in 24U and sU in all evaluated periods. CONCLUSION: One month is required for UI to return to its baseline value after the use of ICA and for patients (after total thyroidectomy and radioiodine therapy) to eliminate the excess of iodine. In addition, sU samples, although not statistically similar to 24U values, can be used as a good marker to evaluate patients suspected of contamination with iodine.
Assuntos
Meios de Contraste , Radioisótopos do Iodo/uso terapêutico , Iodo/urina , Compostos Radiofarmacêuticos , Neoplasias da Glândula Tireoide/radioterapia , Adolescente , Adulto , Carcinoma/radioterapia , Carcinoma/cirurgia , Carcinoma Papilar , Meios de Contraste/farmacocinética , Feminino , Humanos , Iodo/farmacocinética , Compostos de Iodo/urina , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Compostos Radiofarmacêuticos/farmacocinética , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
INTRODUCTION: Iodine is considered to be an essential micronutrient in pregnant women. Iodine placental transport to the embryo-fetus is essential for hormone synthesis and is crucial for nervous system development. However, the relationship between iodine intake and placental weight and its potential implications for the newborn have not been studied. MATERIAL AND METHODS: Iodine intake was analyzed in 77 pregnant women based on urinary iodine excretion (UIE) levels, measured using Pinós modified method (normal value, ≥ 150 µg/L). Placental weight was measured (PW: normal, ≥500 g). In the newborn, weight, height, and head perimeter (HP) were also measured. Placental index (PI: placental weight/newborn weight) was calculated, and was considered normal if ≥0.15. RESULTS: UIE was normal in 50 pregnant women (mean ± SD, 279 µg/L ± 70.22 µg/L) and decreased in 27 (94 µg/L ± 31.49 µg/L). Newborns of mothers with low UIE had a similar weight (3357 g ± 416.30 g; n: 27) to those of mothers with normal UIE (3489 g ± 560.59 g; n: 50). Forty-four percent of mothers with low UIE had PW <500 g, and statistically lower HPs were found in newborns of mothers with low PW (PW(3)500 g: 36.05 cm ± 0.55 cm, n: 54; PW <500 g: 33.93 cm ± 15 cm, n:23, p<0.019). Similar results were found with PI, but they did not reach statistical significance (0,17 ± 0,04; p=0.066). No differences were seen in all other parameters. CONCLUSION: The study suggests the existence of a relationship between PW and HP. This finding may be related to iodine intake during pregnancy.
Assuntos
Cabeça/embriologia , Recém-Nascido , Iodo/deficiência , Placenta/patologia , Placentação , Complicações na Gravidez/fisiopatologia , Adolescente , Adulto , Argentina , Peso ao Nascer , Estatura , Cefalometria , Dieta , Desenvolvimento Embrionário , Feminino , Cabeça/anatomia & histologia , Humanos , Iodo/farmacocinética , Iodo/urina , Troca Materno-Fetal , Necessidades Nutricionais , Tamanho do Órgão , Gravidez , Complicações na Gravidez/urina , Adulto JovemRESUMO
Sex steroids interfere with the pituitary-thyroid axis function, although the reports have been controversial and no conclusive data is available. Some previous reports indicate that estradiol might also regulate thyroid function through a direct action on the thyrocytes. In this report, we examined the effects of low and high doses of estradiol administered to control and ovariectomized adult female rats and to pre-pubertal females. We demonstrate that estradiol administration to both intact adult and pre-pubertal females causes a significant increase in the relative thyroid weight. Serum T3 is significantly decreased in ovariectomized rats, and is normalized by estrogen replacement. Neither doses of estrogen produced a significant change in serum TSH and total T4 in ovariectomized, adult intact and pre-pubertal rats. The highest, supraphysiological, estradiol dose produced a significant increase in thyroid iodide uptake in ovariectomized and in pre-pubertal rats, but not in control adult females. Thyroperoxidase activity was significantly higher in intact adult rats treated with both estradiol doses and in ovariectomized rats treated with the highest estradiol dose. Since serum TSH levels were not significantly changed, we suggest a direct action of estradiol on the thyroid gland, which depends on the age and on the previous gonad status of the animal.
Assuntos
Estradiol/farmacologia , Iodeto Peroxidase/metabolismo , Iodo/farmacocinética , Ovariectomia , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Fatores Etários , Animais , Relação Dose-Resposta a Droga , Estradiol/administração & dosagem , Feminino , Iodeto Peroxidase/sangue , Isótopos de Iodo/administração & dosagem , Isótopos de Iodo/farmacocinética , Tamanho do Órgão , Ratos , Tireotropina/sangue , Tiroxina/sangue , Fatores de TempoRESUMO
OBJECTIVE: We evaluated the influence of intestinal malabsorption on iodine status in patients who had short gut syndrome and received total parenteral nutrition (group I) compared with control subjects who had eutrophia (group II) and patients who had other illnesses but normal digestive tracts (group III). METHODS: Twenty-seven subjects were studied. Iodine intake was determined by the measurement of iodine in ingested food and in parenteral nutrition solutions. Urinary iodine excretion was measured by the Sandell-Kalthoff reaction. Urinary creatinine, anthropometric, and thyroid hormone functions were also determined. RESULTS: Daily iodine intakes were 658 +/- 125 (mean +/- standard deviation), 573 +/- 204, and 629 +/- 208 microg for groups I, II, and III, respectively. Daily urinary iodine excretion levels were 399 +/- 308, 439 +/- 192, and 370 +/- 268 microg and ratios of urinary iodine (micrograms) to creatinine (grams) were 614 +/- 349, 354 +/- 142, and 483 +/- 292, respectively. There were no statistically significant differences across groups. CONCLUSION: In Brazil the iodine provided by food, including iodized salt, has been sufficient to maintain iodine status in patients with short gut syndrome.
Assuntos
Iodo/administração & dosagem , Iodo/farmacocinética , Síndromes de Malabsorção/metabolismo , Oligoelementos/farmacocinética , Adulto , Creatinina/urina , Feminino , Humanos , Absorção Intestinal , Iodo/deficiência , Iodo/metabolismo , Iodo/urina , Síndromes de Malabsorção/terapia , Masculino , Pessoa de Meia-Idade , Nutrição Parenteral Total , Cloreto de Sódio na Dieta/administração & dosagem , Cloreto de Sódio na Dieta/metabolismo , Cloreto de Sódio na Dieta/farmacocinética , Cloreto de Sódio na Dieta/urina , Tireotropina/sangue , Oligoelementos/administração & dosagem , Oligoelementos/deficiência , Oligoelementos/urinaRESUMO
The effect of the phorbol esther phorbol myristate acetate (PMA) on iodide uptake was studied in primary cultures of calf thyroid cells. PMA caused a dose- and time-dependent inhibition of thyrotropin (TSH), forskolin, and db-cAMP stimulation, indicating an effect distal to both TSH receptor and cAMP generation. No action was found on iodide efflux, indicating a selective inhibition of iodide uptake. This inhibition was observed even after 5 minutes of incubation, thus excluding a possible genomic action. Bisindolmaleimide (BS), a specific inhibitor of the protein kinase C (PKC) pathway, reverted the effect of PMA. A similar degree of inhibition of the Na+/K+ adenosine triphosphatase (ATPase) and iodide uptake by PMA was found, thus suggesting a link between both parameters. These results indicate that the PKC pathway inhibits thyroid iodide uptake by an action distal to cAMP generation and probably because of a decrease in Na+/K+-ATPase activity.
Assuntos
Iodetos/antagonistas & inibidores , Iodetos/farmacocinética , Proteína Quinase C/fisiologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Glândula Tireoide/metabolismo , Animais , Bucladesina/farmacologia , Bovinos , Células Cultivadas , Colforsina/farmacologia , Inibidores Enzimáticos/farmacologia , Indóis/farmacologia , Iodo/farmacocinética , Maleimidas/farmacologia , Proteína Quinase C/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Acetato de Tetradecanoilforbol/farmacologia , Glândula Tireoide/citologia , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia , Fatores de TempoRESUMO
Abnormally low(131)I uptakes were noticed in dogs fed with commercial diets at the University Animal Clinic in Buenos Aires, but the total iodine content of eight different commercial diets examined was found to provide an iodine intake above daily requirements. To investigate this anomaly, 18 dogs were distributed into three groups, fed either: (1) a home-prepared diet; (2) a commercial diet; (3) a home-prepared diet supplemented with potassium iodide equivalent to that found in the commercial diet. The(131)I uptake in dogs of groups B and C was significantly decreased, as was basal serum thyroxine (T(4)) and free thyroxine (FT(4)), whereas urinary iodide excretion and serum thyroid stimulating hormone (TSH), were increased. The thyroid releasing hormone (TRH)-TSH test showed an increased response in dogs from group B, while the TRH-T(4)test was inhibited in both groups B and C. The results demonstrate that the excessive amount of iodine present in some commercial diets in Argentina causes a significant impairment of thyroid function and hypothyroidism.
Assuntos
Dieta/veterinária , Doenças do Cão/prevenção & controle , Cães/metabolismo , Hipotireoidismo/veterinária , Iodo/farmacocinética , Tireotropina/sangue , Tiroxina/sangue , Animais , Animais Recém-Nascidos , Hipotireoidismo/prevenção & controle , Iodo/sangue , Iodo/urina , Radioisótopos do Iodo , Testes de Função Tireóidea/veterináriaRESUMO
Presentamos aqui los resultados de un estudio clinico, con la administracion de yodo en pacientes con Queratoconjuntivitis Sicca (QCS) o Sindrome de Sjogren (SS), con el fin de estimular su secreción lagrimal, más del 80%respondieron al tratamiento satisfactoriamente, asi como el 71%de los tratados con bromhexina (grupo control), conocida ya como lacrimoestimulantes. Ambos tratamientos mejoraron la xerostomia en la mayoria de pacientes son (SS)
Assuntos
Bromoexina/administração & dosagem , Iodo/administração & dosagem , Ceratoconjuntivite/diagnóstico , Síndrome de Sjogren/fisiopatologia , Bromoexina/farmacocinética , Bromoexina/uso terapêutico , Iodo/farmacocinética , Iodo/uso terapêutico , Ceratoconjuntivite/etiologia , Ceratoconjuntivite/terapiaRESUMO
Thyroid autoregulation has been linked to an organified iodocompound. Since several iodolipids are produced by the gland their possible role in thyroid autoregulation was examined. The following pure synthetic compounds were prepared: 1) 14-iodo-15-hydroxy-5,8,11-eicosatrienoic acid (I-OH-A); 2) its omega lactone (IL-omega); 3) 5-hydroxy-6-iodo-8,11,14-eicosatrienoic acid delta lactone (IL-delta). Their action on iodine metabolism was studied. Iodine uptake was measured in calf thyroid slices. At 10(-4)M I-OH-A caused a 64% decrease in the T/M ratio, while IL-omega inhibited it by 36% and IL-delta was without effect. At 10(-5)M the inhibition was 44% for I-OH-A and 19% for IL-omega, while T3 was without action. A possible isotopic dilution effect was excluded, and no change in iodine efflux was observed. The inhibition by I-OH-A of iodide uptake was observed after only 15 min preincubation. This compound also decreased 125I accumulation in rats. In calf thyroid slices, I-OH-A at 10(-4)M, inhibited PB125I formation by 80%, IL-omega by 62% and IL-delta by 37%. T3 and arachidonic acid were without action. I-OH-A also caused a dose-dependent inhibition of TSH-stimulated iodide organification. The present results demonstrate, for the first time, that iodinated derivatives of arachidonic acid inhibit thyroid function and mimic the effect of iodide on thyroid autoregulation.