PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “IODINE, RADIOACTIVE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources

[Study on consequences of radioactive iodine pollution and iodine prophylaxis after the Czernobyl accident in the Krakow region].

Program of investigations of effects of radiation and iodine prophylaxis undertaken after Czarnobyl accident in Kraków region had to be modified due to goiter endemy in this region. These modifications included: 1) Division of the region into 3 areas (voivodship Nowy Sacz, urban voivodship Kraków and area of Kielce and Swietokrzyskie mountains). 2) Study on iodine uptake in food and urinary secretion. 3) Examination of iodine level in drinking water, add an attempt of calculation of radiation dose absorbed by thyroid. Characterization of selected areas, principles of selection of study groups are presented as well as organizational details and methods of data collection.

Adolescent↗

Thyroid cancer following exposure to radioactive iodine.

The thyroid gland is one of the most sensitive organs for radiation-induced oncogenesis and the magnitude of the risk from external radiation is well understood. This is not the case for internal radiation derived from the radioiodines, a matter of practical importance because of medical use and potential accidental exposure. This article reviews current knowledge derived from the follow-up of patients receiving diagnostic or therapeutic 131I and populations exposed to radioactive fallout. The latter includes the nuclear power station accident at Chernobyl and the results of atomic bomb development and testing at Hanford, the Nevada Test Site and the Marshall Islands. The most cogent information comes from Chernobyl where an epidemic of childhood thyroid cancer has followed exposure to radioiodine that was mainly 131I. Although much has been learned from this experience about the nature of radioiodine induced thyroid cancer in young children, the reconstruction of thyroid radiation doses is too preliminary to provide accurate knowledge of the risk in comparison to that from external radiation. In the Marshall Islands, much of the exposure was from short-lived radioiodines as well as external radiation, obviating the possibility to determine the risk from 131I. Exposure to 131I in the continental United States from atomic bomb testing is expected to have caused some thyroid cancers, but only in the immediate vicinity of the Nevada Test Site has any evidence of radiation-induced thyroid neoplasms been adduced. This evidence is minimally significant statistically, and not significant for thyroid cancer per se. Medical use of radioiodine has not been observed to cause thyroid cancer but very few of the patients studied were young children, the group most sensitive to thyroid radiation. Despite these limitations, this information is sufficient to make some suggestions concerning protective measures in the case of nuclear accidents and the follow up of individuals who have been exposed.

Humans↗

Use of radioactive iodine for thyroid remnant ablation in well-differentiated thyroid carcinoma to replace thyroid reoperation.

Complete thyroidectomy was recommended for patients with well-differentiated thyroid carcinoma to remove any potential residual contralateral cancer tissue and to facilitate detection of metastatic lesions by radioactive iodide (131I). Unfortunately, 8-32% incidence of severe complications were noted after reoperation. At present, there are still not enough data about the ablative effect of 131I for such conservative surgical treatment of well-differentiated thyroid cancers. The major goal of the present study was to examine the effects of 311I for ablation of thyroid remnants in order to obviate the severe complications associated with reoperation. From January 1977 to December 1995, 210 papillary or follicular thyroid carcinoma patients received subtotal thyroidectomy or lobectomy. After the operation, 46 of the 210 patients received 131I for remnant ablation. At doses of > or = 30 mCi 131I, 38 thyroid remnants were successfully ablated; 25 of 38 (65.8%) patients successfully ablated patients received 30 mCi 131I one-four times. Five patients expired during the follow-up period, including two follicular carcinoma patients who were misinterpreted as having benign lesions in the first operation. Patients in the overall failure versus success group for thyroid remnant ablation revealed increased age, histopathology of follicular carcinoma, higher postoperative 131I uptake in the neck bed, higher postoperative thyroglobulin levels, bigger tumor size, and higher mortality. In conclusion, repeated 30 mCi 131I treatments were adequate for most thyroid remnant ablations following subtotal thyroidectomy or lobectomy in well-differentiated thyroid cancer patients. Misinterpretation of follicular cancer as benign lesions and unresectable tumor comprised the main reasons for mortality.

Adenocarcinoma, Follicular↗

The use of a new radioactive-iodine labeled lipid marker to follow in vivo disposition of liposomes: comparison with an encapsulated aqueous space marker.

The in vivo disposition of multilamellar liposomes extruded at 0.6 micrometers (PC/DPPA/CH/ alpha-T = 4:1:5:0.1 molar ratio) when injected i.v. into mice has been examined utilizing a novel iodinatable phospholipid derivative as a lipid phase marker (p-hydroxybenzamidine phosphatidylethanolamine: 125I-BPE) and compared to that using 14C-inulin as an aqueous phase marker. At times up to 5 h post-dose the disposition of both markers was essentially identical with the exception of blood and intestine, where 125I-BPE levels were consistently higher than 14C-inulin levels. At time intervals from 5-72 h post-dose 125I-BPE levels in all the organs examined were lower than those of 14C-inulin. These differences in the behaviour of the two labels may be explained in terms of exchange of the iodinated lipids, excretion of released inulin and long term metabolism of the lipid marker. We conclude tha 125I-BPE is a useful marker for following liposome disposition in short-term studies particularly in view of the easily quantifiable nature of gamma-radioactivity which obviates the need for sample preparation.

Animals↗

Radioactively iodinated cyclo(His-Pro) crosses the blood-brain barrier and reverses ethanol-induced narcosis.

Cyclo(His-Pro) (cHP) is a peptide widely distributed in the central nervous system (CNS) and peripheral tissues that can affect brain function after either peripheral or CNS administration. This suggests that cHP may be a neuromodulator capable of crossing the blood-brain barrier (BBB). We, therefore, studied the ability of radioactively labeled cHP (I-cHP) to cross the BBB. We found that I-cHP can cross the BBB in either the direction of blood to brain or brain to blood by nonsaturable mechanisms. The rate of entry of I-cHP into the CNS was low in comparison with other peptides, especially considering its relatively low molecular weight and high lipid solubility. However, this slow entry was offset by a long half-life in blood and extreme enzymatic resistance, allowing cHP to accumulate in the CNS. This accumulation was sufficient to allow intravenous cHP to reverse ethanol-induced narcosis, an effect mediated through the CNS. The rate of entry of I-cHP was resistant to conditions that alter the passage of some other substances across the BBB or that have been shown to affect cHP metabolism such as aging, diabetes, and pretreatment with aluminum. Entry of cHP into the brain was not retarded by binding to serum proteins. Significant amounts of I-cHP entered the serum, brain, and other tissues after intraperitoneal administration, the route used in many studies of cHP. Taken together, these results show that cHP is a highly stable peptide that, after intravenous injection, slowly enters the brain by a nonsaturable mechanism in amounts large enough to affect such aspects of the CNS as ethanol-induced narcosis.

Animals↗