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Biomedical subjects

G H Daniels

Publications and source records attributed to G H Daniels.

At least 19 recordsLinked to original sources
PubMed2003

Overexpression of type 2 iodothyronine deiodinase in follicular carcinoma as a cause of low circulating free thyroxine levels.

Thyroid function is normally undisturbed in patients with thyroid carcinoma. We have identified three patients with large or widely metastatic follicular thyroid carcinoma who had a persistently increased ratio of serum T(3) to T(4) in the absence of autonomous production of T(3) by the tumor. To investigate the possibility of tumor-mediated T(4) to T(3) conversion, we assayed types 1 and 2 iodothyronine selenodeiodinase (D1 and D2) activity in a 965-g follicular thyroid carcinoma resected from one of these patients. The V(max) for D2 was 8-fold higher than in normal human thyroid tissue. Resection of this tumor, leaving the left thyroid lobe intact, normalized the serum T(3) to T(4) ratio. In two other patients, treatment with sufficient levothyroxine to suppress TSH was associated with a high normal T(3) and a subnormal free T(4) index. In one, concomitant administration of the D1 inhibitors, propylthiouracil and propranolol, did not decrease the elevated serum T(3) to T(4) ratio. These data illustrate that increased T(4) to T(3) conversion in follicular thyroid carcinomas, probably by D2, can cause a significant perturbation in peripheral thyroid hormone concentrations.

Adenocarcinoma, Follicular↗
PubMed2001

Association between lithium use and thyrotoxicosis caused by silent thyroiditis.

OBJECTIVE: To determine the incidence of silent thyroiditis in lithium users and characterize lithium-associated thyrotoxicosis. DESIGN: Retrospective record review. PATIENTS: 400 consecutive patients (300 with Graves' disease and 100 with silent thyroiditis) who underwent radioiodine scanning of the thyroid. MEASUREMENTS: Odds of lithium exposure. RESULTS: The odds of lithium exposure were increased 4.7-fold in patients with silent thyroiditis compared with those with Graves' disease (95% CI: 1.3, 17). Lithium-associated silent thyroiditis occurred with an incidence rate of approximately 1.3 cases per 1000 person-years, and lithium-associated thyrotoxicosis occurred with an incidence rate of approximately 2.7 cases per 1000 person-years, higher than the reported incidence rates of silent thyroiditis (< 0.03-0.28 cases per 1000 person-years) and of thyrotoxicosis (0.8-1.2 cases per 1000 person-years) in the general population. CONCLUSION: Thyrotoxicosis caused by silent thyroiditis might be associated with lithium use.

Adult↗
PubMed2001

Atypical subacute thyroiditis: preliminary observations.

Nine patients with painless or minimally painful subacute thyroiditis were seen between late June and October 2000. Six had a history of antecedant viral symptoms. Thyroid peroxidase antibodies were negative in eight patients tested; none had a family history of autoimmune thyroid disease. It is possible that these patients represent examples of postviral painless subacute thyroiditis (atypical subacute thyroiditis). In order to establish the nature of the syndrome, cytological examination, HLA typing, and long-term follow-up are necessary.

Adult↗
PubMed2000

American Thyroid Association guidelines for detection of thyroid dysfunction.

OBJECTIVE: To define the optimal approach to identify patients with thyroid dysfunction. PARTICIPANTS: The 8-member Standards of Care Committee of the American Thyroid Association prepared a draft, which was reviewed by the association's 780 members, 50 of whom responded with suggested revisions. EVIDENCE: Relevant published studies were identified through MEDLINE and the association membership's personal resources. CONSENSUS PROCESS: Consensus was reached at group meetings. The first draft was prepared by a single author (P.W.L.) after group discussion. Suggested revisions were incorporated after consideration by the committee. CONCLUSIONS: The American Thyroid Association recommends that adults be screened for thyroid dysfunction by measurement of the serum thyrotropin concentration, beginning at age 35 years and every 5 years thereafter. The indication for screening is particularly compelling in women, but it can also be justified in men as a relatively cost-effective measure in the context of the periodic health examination. Individuals with symptoms and signs potentially attributable to thyroid dysfunction and those with risk factors for its development may require more frequent serum thyrotropin testing.

Adult↗
PubMed1999

A comparison of recombinant human thyrotropin and thyroid hormone withdrawal for the detection of thyroid remnant or cancer.

Recombinant human TSH has been developed to facilitate monitoring for thyroid carcinoma recurrence or persistence without the attendant morbidity of hypothyroidism seen after thyroid hormone withdrawal. The objectives of this study were to compare the effect of administered recombinant human TSH with thyroid hormone withdrawal on the results of radioiodine whole body scanning (WBS) and serum thyroglobulin (Tg) levels. Two hundred and twenty-nine adult patients with differentiated thyroid cancer requiring radioiodine WBS were studied. Radioiodine WBS and serum Tg measurements were performed after administration of recombinant human TSH and again after thyroid hormone withdrawal in each patient. Radioiodine whole body scans were concordant between the recombinant TSH-stimulated and thyroid hormone withdrawal phases in 195 of 220 (89%) patients. Of the discordant scans, 8 (4%) had superior scans after recombinant human TSH administration, and 17 (8%) had superior scans after thyroid hormone withdrawal (P = 0.108). Based on a serum Tg level of 2 ng/mL or more, thyroid tissue or cancer was detected during thyroid hormone therapy in 22%, after recombinant human TSH stimulation in 52%, and after thyroid hormone withdrawal in 56% of patients with disease or tissue limited to the thyroid bed and in 80%, 100%, and 100% of patients, respectively, with metastatic disease. A combination of radioiodine WBS and serum Tg after recombinant human TSH stimulation detected thyroid tissue or cancer in 93% of patients with disease or tissue limited to the thyroid bed and 100% of patients with metastatic disease. In conclusion, recombinant human TSH administration is a safe and effective means of stimulating radioiodine uptake and serum Tg levels in patients undergoing evaluation for thyroid cancer persistence and recurrence.

Adult↗
PubMed1997

Comparison of administration of recombinant human thyrotropin with withdrawal of thyroid hormone for radioactive iodine scanning in patients with thyroid carcinoma.

BACKGROUND: To detect recurrent disease in patients who have had differentiated thyroid cancer, periodic withdrawal of thyroid hormone therapy may be required to raise serum thyrotropin concentrations to stimulate thyroid tissue so that radioiodine (iodine-131) scanning can be performed. However, withdrawal of thyroid hormone therapy causes hypothyroidism. Administration of recombinant human thyrotropin stimulates thyroid tissue without requiring the discontinuation of thyroid hormone therapy. METHODS: One hundred twenty-seven patients with thyroid cancer underwent whole-body radioiodine scanning by two techniques: first after receiving two doses of thyrotropin while thyroid hormone therapy was continued, and second after the withdrawal of thyroid hormone therapy. The scans were evaluated by reviewers unaware of the conditions of scanning. The serum thyroglobulin concentrations and the prevalence of symptoms of hypothyroidism and mood disorders were also determined. RESULTS: Sixty-two of the 127 patients had positive whole-body radioiodine scans by one or both techniques. The scans obtained after stimulation with thyrotropin were equivalent to the scans obtained after withdrawal of thyroid hormone in 41 of these patients (66 percent), superior in 3 (5 percent), and inferior in 18 (29 percent). When the 65 patients with concordant negative scans were included, the two scans were equivalent in 106 patients (83 percent). Eight patients (13 percent of those with at least one positive scan) were treated with radioiodine on the basis of superior scans done after withdrawal of thyroid hormone. Serum thyroglobulin concentrations increased in 15 of 35 tested patients: 14 after withdrawal of thyroid hormone and 13 after administration of thyrotropin. Patients had more symptoms of hypothyroidism (P<0.001) and dysphoric mood states (P<0.001) after withdrawal of thyroid hormone than after administration of thyrotropin. CONCLUSIONS: Thyrotropin stimulates radioiodine uptake for scanning in patients with thyroid cancer, but the sensitivity of scanning after the administration of thyrotropin is less than that after the withdrawal of thyroid hormone. Thyrotropin scanning is associated with fewer symptoms and dysphoric mood states.

Adult↗
PubMed1996

Treatment guidelines for patients with thyroid nodules and well-differentiated thyroid cancer. American Thyroid Association.

A set of minimum clinical guidelines for use by primary care physicians in the evaluation and management of patients with thyroid nodules or thyroid cancer was developed by consensus by an 11-member Standards of Care Committee (the authors of the article) of the American Thyroid Association, New York, NY. The participants were selected by the committee chairman and by the president of the American Thyroid Association based on their clinical experience. The committee members represented different geographic areas within the United States, to reflect different practice patterns. The guidelines were developed based on the expert opinion of the committee participants, as well as on previously published information. Each committee participant was initially assigned to write a section of the document and to submit it to the committee chairman, who revised and assembled the sections into a complete draft document, which was then circulated among all committee members for further revision. Several of the committee members further revised and refined the document, which was then submitted to the entire membership of the American Thyroid Association for written comments and suggestions, many of which were incorporated into a final draft document, which was reviewed and approved by the Executive Council of the American Thyroid Association.

Adenocarcinoma, Follicular↗
PubMed1995

Acute compartment syndrome in a hypothyroid patient.

Acute compartment syndrome (ACS) is caused by conditions that either decrease the size of the compartment of increase the content of the compartment. Intracompartmental pressures are raised, thereby initiating a sequence of events that results in myoneural injury. Although limb trauma is the most common and well-organized etiology of ACS, the cause is frequently not readily apparent. Thyroid disease is not a commonly recognized cause of ACS; only one case of ACS associated with hypothyroidism has been previously reported. We now describe a second case of ACS in a patient with severe hypothyroidism and discuss the possible pathogenesis of this association.

Adult↗
PubMed1994

Diagnostic use of recombinant human thyrotropin in patients with thyroid carcinoma (phase I/II study).

Current diagnostic studies [radioiodine uptake and serum thyroglobulin (Tg) levels] for residual or metastatic thyroid tissue in patients with differentiated thyroid carcinoma require a hypothyroid status necessary for adequate endogenous TSH stimulation. However, almost all patients have symptoms of clinical hypothyroidism during this period. As shown in the present study, recombinant human TSH (rhTSH) allows stimulation of 131I uptake and Tg release from residual thyroid tissue in euthyroid patients. To assess safety, dosage, and preliminary efficacy, comparison was made of the stimulation of 131I uptake and Tg release after rhTSH administration and after T3 withdrawal in 19 patients after a recent thyroidectomy for differentiated thyroid carcinoma. Various doses (10-40 U) of rhTSH were injected im for 1-3 days in patients receiving suppressive doses of T3. Twenty-four hours after the last dose of rhTSH, 1-2 mCi 131I were administered, followed by a neck and whole body scan 48 h later. After discontinuing T3 for a median period of 19 days (range, 15-28), endogenous serum TSH levels were markedly elevated, and the patients were given a second dose of 131I and rescanned 48 h later. The injections of rhTSH were tolerated well. No major adverse effects were reported; nausea was reported in 3 (16%) and vomiting in 1 of the patients treated with high doses. The quality of life, as measured by two psychometric scales, was far better during rhTSH treatment than after T3 withdrawal. The peak levels of serum TSH (mean +/- SD) after a single dose of 10, 20, or 30 U were 127 +/- 19, 309 +/- 156, and 510 +/- 156 mU/L, respectively, and occurred 2-8 h after injection. Twenty-four hours after the injection, TSH levels decreased to 83 +/- 31, 173 +/- 73, and 463 +/- 148 mU/L in these treatment groups, respectively. The quality of the thyroid scans and the number of sites of abnormal 131I uptake were similar after rhTSH treatment and in the hypothyroid scans in 12 (63%) patients. Two additional sites of uptake in the chest and one in the thyroid bed, not visible on the hypothyroid scans, were identified in 3 (16%) patients after rhTSH. In 1 patient a focus of uptake was better visualized after rhTSH than after withdrawal. In 3 (16%) other patients, 1 lesion in the chest and 2 in the neck were seen only after T3 withdrawal.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

Fine-needle biopsy of cervical lymph nodes in patients with thyroid cancer: a prospective comparison of cytopathologic and tissue marker analysis.

Tissue levels of thyroglobulin (Tg) or calcitonin were compared with specimens from neck lymph node biopsy in patients with suspected recurrent differentiated (papillary or follicular) or medullary thyroid cancer. Thirty-six neck lymph node biopsies were performed in 29 patients. Tissue Tg levels were obtained from 31 specimens from patients with differentiated thyroid cancers, and tissue calcitonin levels were obtained from five specimens from patients with medullary cancer. Thirteen nodes were diagnosed as negative for cancer at surgery (n = 3) or follow-up sonography (n = 10). Malignant disease was confirmed at surgery in 23 of the 36 lymph nodes. Cytopathologic examination had a sensitivity of 91% and a specificity of 100%. Tissue Tg levels ranged from 0 to 3.5 ng/mL (mean, 1.5 ng/mL; median, 1.2 ng/mL) in 12 of the 13 benign lymph nodes and from 21 to 247,500 ng/mL (mean, 30,600 ng/mL; median, 2,330 ng/mL) in the 23 malignant nodes. Tissue calcitonin levels were elevated (range, 850-703,125 pg/mL; mean, 184,762 pg/mL; median, 17,538 pg/mL) in four malignant nodes and were normal (3.0 pg/mL) in one benign node. Diagnostic sensitivity of tissue markers was 91%. Specificity was 91%. The combined diagnostic sensitivity and specificity of tissue marker analysis and cytopathologic examination was 100%.

Adenocarcinoma↗
PubMed1992

Extra-adrenal pheochromocytoma.

Extra-adrenal pheochromocytomas may arise in any portion of the paraganglion system, although they most commonly occur below the diaphragm. The most common site of occurrence of extra-adrenal pheochromocytoma is the superior para-aortic region between the diaphragm and lower renal poles. Although the traditional teaching has been that 10% of all pheochromocytomas are at extra-adrenal sites, this may be an underestimation. Extra-adrenal pheochromocytomas probably represent at least 15% of adult and 30% of childhood pheochromocytomas. They may be malignant in up to 40% of the cases, although conflicting data add to the uncertainty of this point. Patients with tumors arising at extra-adrenal sites commonly present with headache, palpitations, sweating and hypertension. The diagnosis is most often confirmed by demonstrating increased catecholamine production, usually by measurement of urinary catecholamines and/or their metabolites. CT scanning is presently the imaging procedure of choice for localization. The roles of MRI and 131I-MIBG scintigraphy in the localization process are still being determined. Thorough preoperative pharmacological preparation, attentive intraoperative monitoring and aggressive surgical therapy all have an important role in achieving the safest and most successful outcome. Complete surgical excision is the treatment of choice for primary extra-adrenal pheochromocytoma as well as recurrent or metastatic disease. When residual tumor cannot be resected, medical therapy for symptomatic relief is preferred, since radiotherapy and chemotherapy have limited effectiveness. Extra-adrenal pheochromocytomas are more likely to recur and to metastasize than their adrenal counterparts, making lifelong followup with annual determinations of catecholamine production essential.

Humans↗