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PubMed1987

Circadian and circannual variations of thyroid function in children 11 +/- 1.5 years of age with and without endemic goiter.

A group of 194 children 11 +/- 1.5 years of age from Tirgoviste, Romania, an endemic goiter area, were studied over a 24-hr span (six blood samples at 4-hr intervals) during all four seasons. One hundred thirty-four of the children had some clinical evidence of endemic goiter, and 60 had none. Total and free T3 and T4, reverse T3, thyroglobulin, thyroxin-binding globulin (TBG; three seasons only), and TSH were studied. The circadian rhythms were analyzed by cosinor and the circannual variations by ANOVA. Children with and without endemic goiter showed circadian rhythms in all functions studied except free T4 for which no statistically significant rhythm was detected in the children with goiter. There were differences in the acrophase of total T3, free T3, and TBG, with phase advance in the children with goiter in total T3 and free T3 and a phase delay in TBG. Mesor and amplitude showed no differences except in total T4 for which the amplitude in the children with goiter was statistically significantly lower than in the children without goiter. Children with and without endemic goiter showed seasonal variations in total T4 and free T4 as well as total T3, free T3, and reverse T3, with the highest values in the fall; in thyroxin-binding globulin the highest values were in the winter; and in TSH the highest values were in the summer. There was no significant seasonal variation in thyroglobulin. There was no difference in the circannual variation between children with and without endemic goiter.

Child↗
PubMed1978

[Indications and procedures in conservative goiter treatment].

A review of the literature shows that thyroid hormone therapy causes 13 to 40% of euthyroid goiters to disappear and brings about a reduction in goiter size in another 30 to 50%. The hormonal treatment is more successful with smaller goiters. Uninodular goiters respond on the average less well than diffuse and multinodular goiters. In Switzerland, about 33% of adult persons have goiters, albeit mostly of small size. This renders impracticable investigation or treatment of all goiters. It is recommended that only goiters which are esthetically disturbing or which cause pressure symptoms be treated. An operation must always be performed when there is suspicion of thyroid cancer or in the presence of threatening pressure symptoms. In all the other cases, thyroid hormone therapy may be tried. If an operation cannot be performed for cardiac or other reasons, radioiodine will relieve pressure symptoms due to goiter in over 65% of cases.

Goiter↗
PubMed1995

Prevalence of goiter in school children in the Wan-Hwa district of Taipei.

Salt has been iodized in Taiwan since 1967. To understand goiter status after salt iodization, we studied the prevalence of goiter in school children in rural areas where tap water or underground water are used. To further elucidate the prevalence of goiter in urban areas where tap water is used, we studied school children from the Tong-Yuan and Lao-Song elementary schools located in the Wan-Hwa District of Taipei. Thyroid enlargement was examined by palpation as recommended by the World Health Organization. Thyroid antibodies and hormones were determined in school children with goiter and in age- and sex-matched normal control children using particle agglutination methods and radioimmunoassay. A total of 4,623 school children were examined. Of these, 129 children (2.8%) had goiters of grade I or above, or nodular goiters. The prevalence of goiter was similar to that of Putai and Peimen in southern Taiwan where tap water is used, but less than that of Tachia and Chingshuei in middle Taiwan where underground water is used. The prevalence of goiter was much lower than recent studies in Tung-Lo, an oil-bearing area in middle Taiwan, where there was a 12.9% prevalence in school children residing in hill districts who relied on underground water for drinking purposes, and 8.2% in school children residing on lower plains, who depended upon tap water for drinking purposes. The prevalence of goiter is highly related to the quality of drinking water.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1994

Thyroxine treatment of benign goiter.

The conservative therapy of endemic as well as sporadic goiter is the TSH suppressive therapy with thyroxine. In the last decade, this therapeutic concept as well as the role of TSH in goiter development fell into disrepute. It has become evident that TSH mainly regulates thyroid function, induces hypertrophy of the follicular cells and increases the blood flow within the thyroid gland. The intrathyroidal iodine deficiency itself and the increased activity of local growth factors, however, may be the main causes of initiation, promotion and maintenance of hyperplasia. The clinical observation of a "shrinking" goiter during thyroxine therapy is now well established by ultrasound investigations as a decrease in goiter volume of maximal 30 to 40% within the first few months of treatment. Afterwards no further significant reduction in goiter size has been demonstrated so far. Stopping treatment results in an increase of goiter volume within a few weeks. These rapid changes can only be related to changes in the size of cells, follicles and vessels and not to growth or necrosis of thyroid cells. In comparison, treatment of endemic goiter with iodine also lead to a reduction of hypertrophy, but as demonstrated in rats, also to a reduction of hyperplasia. Treatment with iodine compared to thyroxine has a prolonged effect on reduction of goiter size even after withdrawal of the substitution. The main question that has to be discussed is whether the hyperplastic part of an endemic goiter in adults can be treated at all, either with thyroxine or iodine or both.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

[Analysis of the factors associated with recurrence of post-thyroidectomy goiter].

The factors associated with post-thyroidectomy goiter recurrence in benign thyroid disease are not clearly defined, especially prophylactic thyroxine treatment. PURPOSE--To determine the prevalence, characteristics and associated factors of recurrence of goiter post-thyroidectomy in patients submitted to surgery for benign disease. METHODS--Sixty-six patients, 53 female and 13 male (mean age = 51 yrs., range 20-82 yrs.), previously (5.6 +/- 6.1 yrs.) submitted to thyroidectomy (lobectomy, n = 50; nodulectomy, n = 5; subtotal thyroidectomy, n = 11) for benign thyroid disease were included. Measurements of T3, T4, TSH, thyroid microsomal autoantibody titers and thyroid ultrasonography were performed at the time of the study. Recurrence of goiter post-thyroidectomy was defined on ultrasonography as the presence of residual thyroid volume > 20mL and/or new nodules > 0.5mL not detected at surgery. RESULTS--Seven patients (10%) developed recurrence of goiter. The post-operative follow-up period was longer in the recurrence group and there was no difference between the two groups as to age, sex, familial history of thyropathy and preoperative goiter diagnosis. In multiple regression analysis only the following post-operative period was significantly associated to goiter recurrence (beta = 0.02; R2 = 0.16; p < 0.05) and influenced the goiter recurrence rate by 14%. Familial history of thyropathy, thyroxine treatment in non-supressible doses after thyroidectomy and seric T4 and TSH levels did not influence the recurrence. CONCLUSION--Recurrence of goiter post-thyroidectomy occurs in a small number of patients and is related to longer post-operative follow-up time. Thyroxine treatment in non-supressible doses after surgery is not related to goiter recurrence prevention.

Adult↗
PubMedDate not supplied

[Multinodular goiter. Epidemiology and prevention].

Nodular goiter is the natural evolution of nontoxic goiter, that may be endemic, sporadic or familiar. Iodine deficiency is the cause of endemic goiter, while genetical defects, impairing the thyroid hormone biosynthetic efficiency or altering the number and/or activity of growth factor receptors, play the major role in the pathogenesis of sporadic and familiar nontoxic goiter. The prevalence of nodular goiter is directly related to the degree of iodine deficiency that is still present in several areas of the world. In iodine deficient areas such as some Italian regions, nodular goiter is present in 25-33% of the population, its frequency increasing with age. In iodine sufficient areas the prevalence of nodular goiter is comprised between 0.4 and 7.2% high in iodine deficient areas and about 4% in iodine sufficient countries, its frequency increasing with the age. Dysphagia, dyspnea and coarsening of the voice may occur for esophagous, tracheal or laryngeal nerve compression, respectively. Iodine deficiency has little if any effect on the frequency of thyroid carcinoma, while, with regard to the histological pattern, it leads to an increased ratio papillary/follicular. Thyroid function is normal in uncomplicated nontoxic goiter. However, the evolution of nodular goiter is toward the functional autonomy of nodules that may result in thyrotoxicosis. Hypothyroidism is rare and is usually the result of thyroid autoimmunity. All the cases due to iodine deficiency can be prevented by an adequate iodine prophylaxis that can be accomplished in industrialized countries by the use of sale enriched in iodine.

Goiter, Nodular↗
PubMed1991

The problem of the nodular goiter.

Nodular goiter is a worldwide problem involving millions of persons. Endemic goiter, and associated cretinism, is totally preventable by ensuring an adequate dietary iodine intake and eliminating malnutrition and dietary goitrogens. Therapy, on the other hand, is difficult in that the goiters often do not regress and the cretinoid changes are irreversible. Nonendemic goiter due to autoimmune thyroid disease, genetic defects in thyroid hormone biosynthesis, and environmental goitrogens or neoplasia is not usually preventable. The usual therapy, involving TSH suppression by administration of L-thyroxine orally, will frequently bring about regression of early, diffuse goiters but is often ineffective in bringing about regression of large, multinodular goiters. In these patients, surgical removal of the goiter may be necessary for alleviation of obstructive symptoms. Further research is needed to elucidate the factors involved in the development of these multinodular goiters and to control the autocrine and paracrine factors involved in nodule growth.

Goiter, Endemic↗
PubMed2003

Orthopnea and tidal expiratory flow limitation in patients with euthyroid goiter.

BACKGROUND: Nontoxic goiters can cause extrathoracic upper airway obstruction and, if large, may extend into the thorax, causing intrathoracic airway obstruction. Although patients with goiter often report orthopnea, there are few studies on postural changes in respiratory function in these subjects. PURPOSE: The aim of this study was to investigate the postural changes in respiratory function and the presence of flow limitation (FL) and orthopnea in patients with nontoxic goiter. METHODS: In 32 patients with nontoxic goiter, respiratory function was studied in seated and supine position. Expiratory FL was assessed with the negative expiratory pressure method. Goiter-trachea radiologic relationships were arbitrarily classified as follows: grade 1, no evidence of tracheal deviation; grade 2, tracheal deviation present in lateral and/or anteroposterior plane but with tracheal compression < 20%; and grade 3, tracheal deviation present with compression > 20%. Subgroups were considered according to this classification and occurrence of orthopnea and FL. RESULTS: In all three groups of patients, the average maximal expiratory flow at 50% of FVC/maximal inspiratory flow at 50% of FVC ratios were > 1.1, suggesting the presence of upper airway obstruction. Grade 3 patients had a significantly lower expiratory reserve volume and maximal expiratory flow at 25% of FVC and higher airway resistance and 3-point FL score than patients with grade 1 and grade 2. The prevalence of orthopnea was highest in patients with grade 3 (75%, as compared to 18% in the grade 1 group). In patients with orthopnea, the prevalence of intrathoracic goiter was also higher (78%, vs 21% in patients without orthopnea). CONCLUSION: There is a high prevalence of orthopnea in patients with goiter, especially when the location is intrathoracic and causes a reduction of end-expiratory lung volume and flow reserve in the tidal volume range, promoting FL especially in supine position. Obesity is a factor that increases the risk of orthopnea in patients with goiter.

Cross-Sectional Studies↗
PubMed1985

[Pathomorphism of endemic goiter].

Pathomorphism of goiter developing against the background of goiter prevention in the Bukovina endemic area was studied. Subdivision of goiter into endemic and sporadic lost its significance due to the stabilization and levelling of the goiter morbidity. The true (simple or benign) goiter is characterized by an euthyroid course, predominant affection of adult women and domination of the nodular variants. A goiter node is a hyperplastic structural-functional gland unit--the thyron. The leading role in the goiter etiology belongs to endogenous deficiency of thyroid hormones, local factors are significant in the goiter pathogenesis.

Adult↗
PubMed1976

Evolution of autonomy in idiopathic non-toxic goiter, evaluated by regional suppressibility of 99mTc-uptake and TSH response to TRH.

Seventeen euthyroid patients with non-toxic goiter were studied, 7 had diffuse goiters and 10 had nodular goiters. The TSH response to TRH and the 99mTc-uptake were measured before and after T3 suppression. The uptake, measured with a gamma camera, was calculated for the whole gland and for a maximum of 6 regions within the thyroid gland. The suppressibility of 99mTc-uptake (percent change of uptake) ranged from 0 to 95%, it was significantly greater in patients with diffuse than in those with nodular goiters, and was alike in nodular and internodular tissue. The patients with diffuse goiter were significantly younger than those with nodular goiter. Abolished TSH response to TRH was seen in 2 patients with negative T3 suppression tests. In another 2 patients impaired TSH response was associated with impaired suppressibility. In 13 patients with normal TRH tests, the suppression of uptake was normal in 8 and subnormal in 5. The results suggest that nodularity and functional autonomy may develop in non-toxic goiters. In some of these goiters the mass of autonomous tissue may be large enough to cause negative TRH tests, probably indicating hypersecretion of thyroid hormones, although not necessarily above the normal range.

Goiter↗
PubMed1963

Non-toxic goiter treatment with 1-triiodothyronine and 1-thyroxine.

Twenty-one patients with goiters-four diffuse and 17 nodular-were treated with I-triiodothyronine and I-thyroxine in doses to tolerance. The four diffuse goiters were barely palpable at the end of the treatment. The average dose of I-triiodothyronine required was 100 mcg. per day. The average dose of I-thyroxine was 0.3 mg. per day. Of the 17 multinodular goiters, 11 showed at least a 50 per cent reduction in size. The average dose of I-triiodothyronine used was 125 mcg. In six cases the gland did not change in size; in three of the six the lesion was diagnosed, at operation, as microfollicular and macrofollicular colloid goiter. Hypermetabolic symptoms may occur when doses of 100 mcg. or more of I-triiodothyronine are used. Results indicated that suppressive therapy with thyroid hormone to tolerance is effective in diffuse goiters. It is only partially effective in the treatment of multinodular goiters. In the cases in which operation was done, no change in the basic histological goiter structure was observed.

Drug Tolerance↗
PubMed2002

Association of tobacco smoking with goiter in a low-iodine-intake area.

BACKGROUND: Goiter development depends on genetic and environmental factors. The major environmental factor is iodine intake, whereas diverging results have been published concerning the association between smoking and goiter. METHODS: A comparable, cross-sectional study was performed of patients from 2 areas in Denmark with mild and moderate iodine deficiency. A random sample of women and men in selected age groups from the general community was investigated; 4649 subjects participated. Smoking habits were investigated with questionnaires and interviews. Ultrasonography and clinical examination of the thyroid were performed, serum thyroglobulin was measured, and iodine concentration in spot urine samples was analyzed. Data were analyzed in linear models and logistic regression analyses. RESULTS: Serum thyroglobulin level and thyroid volume at ultrasonography were positively associated with smoking habits (P<.001); the association was stronger in the area with the lowest iodine intake (interaction: P<.001 for thyroglobulin, P =.04 for thyroid volume). A positive association with smoking was also found for thyroid enlargement (odds ratio, 2.9; 95% confidence interval, 2.2-3.7) and palpable goiter (odds ratio, 3.1; 95% confidence interval, 1.6-5.8). Ex-smokers had a goiter prevalence close to that of never smokers. The fraction of goiter cases attributable to smoking was 49% (95% confidence interval, 29%-65%). CONCLUSIONS: Thyroid volume and goiter prevalence were closely associated with smoking habits, with the strongest association being found in the area with the most pronounced iodine deficiency. This may have implications for future goiter prevalences in Third World countries, with their increasing use of tobacco. Half of goiter cases in this population could be ascribed to smoking.

Adolescent↗
PubMed1994

Endemic goiter and thyroid function in central-southern Sardinia. Report on an extensive epidemiological survey.

UNLABELLED: Although the existence of endemic goiter and cretinism in Sardinia is known since to ancient time, scanty information collected according to WHO criteria is available. In the present paper the results of an extensive epidemiological survey carried out in juvenile population living in some rural and/or hilly villages in the provinces of Nuoro and Oristano in Central-Southern Sardinia and in urban area of Cagliari, are reported. In the majority of the villages the mean urinary iodine excretion was lower than 60 micrograms/L; the goiter prevalence ranged between 39% and 61% in the district of Nuoro and between 21% and 56% in the district of Oristano. In the control area the urinary iodine excretion was 105 micrograms/L with a goiter prevalence of 12%. Goiter prevalence was not always inversely related to urinary iodine excretion. No relevant thyroid function alterations were found. IN CONCLUSION: 1) in extraurban areas of Central-Southern Sardinia mild to moderate iodine deficiency and endemic goiter are still a widespread problems; 2) also in urban area endemic goiter prevalence is still higher than 10%; 3) extemporary urinary samples are inadequate for assessing the severity of goiter endemia in mild to moderate iodine deficiency; 4) in mildly affected districts palpation is inaccurate for assessing the prevalence of goiter; 5) no relevant alterations of thyroid function were documented in juvenile population.

Adolescent↗
PubMed2003

[Is primary total thyroidectomy justified in benign multinodular goiter? Results of a prospective quality assurance study of 45 hospitals offering different levels of care].

INTRODUCTION: After subtotal resection of multinodular goiter, rates of up to 40% are reported for recurrent goiter in the long-term follow-up. Because of the increased morbidity of surgery for recurrent goiter, this study evaluated the preconditions that would justify total thyroidectomy as part of the primary therapy concept for benign multinodular goiter. MATERIAL AND METHODS: The Quality Assurance Study of Benign and Malignant Goiter covering the period from 1 January to 31 December 1998 assessed 5195 patients treated for benign goiter by primary bilateral resection. With respect to the extent of resection three groups were analyzed: bilateral subtotal resection (ST+ST, n=4580), subtotal resection with contralateral lobectomy (ST+HT, n=527), and total thyroidectomy (TT, n=88). RESULTS: The age of the patients was significantly higher (60.3 years) in the TT group than in the ST+ST (52.5 years) and ST+HT (55.6 years) groups. ASA classification grades III and IV were significantly more frequent in the TT group. The postoperative morbidity increased with the extent of resection. The rate of permanent recurrent laryngeal nerve (RLN) palsy was 0.8% for ST+ST, 1.4% for ST+HT, and 2.3% for TT and of permanent hypoparathyroidism 1.5% for ST+ST, 2.8% for ST+HT, and 12.5% for TT. Multivariate analysis showed that the extent of resection significantly increased the risk of RLN palsy (transient RR 0.5, permanent RR 0.4) and hypoparathyroidism (transient RR 0.2,permanent RR 0.08). The surgeon's experience (RR 0.6) and identification of the RLN (RR 0.5) reduced the risk of permanent RLN palsy. Additionally, the development of permanent hypoparathyroidism was reduced if at least two parathyroid glands (RR 0.4) were identified. CONCLUSION: Total thyroidectomy is associated with an increased rate of RLN palsies and hypoparathyroidism in comparison to less extensive thyroid surgery. In the hands of well-trained surgeons using an appropriate intraoperative technique, primary thyroidectomy is justified if the patient has an increased risk of recurrent goiter. Due to the increased postoperative morbidity after total thyroidectomy, subtotal thyroid resection based on the morphologic changes in the thyroid gland is still recommended as the standard treatment regimen for multinodular goiter.

Female↗
PubMed2000

Therapeutic options in the management of toxic and nontoxic nodular goiter.

Nodular goiter is present in 500 to 600 million people and is usually secondary to endemic iodine deficiency. Despite adequate iodine intake, 4% to 6% of American adults are goitrous. Sporadic nodular goiter ensues from the natural heterogeneity of thyroid follicular cells, which, when amplified by yet unidentified trophic stimuli, results in episodes of proliferating, rapidly dividing micronodules. The initial small diffuse goiter evolves into a multinodular goiter (MNG) with 1 or more dominant nodules that may or may not be autonomous. An autonomous functioning thyroid adenoma (AFTA) usually possesses a somatic gain-of-function mutation of the thyrotropin (TSH) receptor associated with rapid growth, hemorrhagic necrosis, and reparative fibrosis that accentuate goiter nodularity. Diagnostic evaluation consists of patient history and physical examination, serum TSH determination, free thyroxine and free triiodothyronine measurements, and imaging studies assessing goiter function, size, and anatomy. If treatment is required, L-thyroxine, thionamides, surgery, radioiodine (I-131), and percutaneous ethanol injection (PEI) are effective in selected patients. In euthyroid patients, L-thyroxine reduces goiter size in some patients, but continued therapy is required to prevent regrowth. Thionamides control the hyperthyroidism of toxic nodular goiter in preparation for more definitive therapy, but are rarely used long term. Surgery and I-131 are most commonly selected for definitive therapy for the toxic AFTA, and the toxic or euthyroid MNG, but PEI is effective in selected toxic AFTAs.

Goiter, Nodular↗
PubMed1999

Goiter associated with acromegaly: sonographic and scintigraphic findings of the thyroid gland.

Elevation in serum human growth hormone (GH) level is known to be a factor that causes goiter development. The present study was designed to analyze sonographic and scintigraphic appearances of the thyroid in patients with acromegaly. The records of 48 consecutive patients with acromegaly were examined. Two patients had a history of operation for thyroid cancer. One had an atrophic thyroid gland after 131I treatment for Graves' disease. Goiter was palpable in 39 of the remaining 45 patients. Neither ultrasonography (US) nor scintigraphy was performed in 17 patients, including 6 with no palpable goiter and 11 with small diffuse goiter (group 1). Of the remaining 28 patients who underwent US, 14 had a moderately or markedly enlarged diffuse goiter (group 2), 13 were diagnosed as having adenomatous goiter (group 3), and 1 had a solitary cystic nodule. Among 11 patients in group 3 who underwent 123I or 99mTc thyroid scintigraphy, 6 showed uneven uptake, and 2 with undetectably reduced levels of thyrotropin (TSH) showed localized functioning areas. The mean serum TSH concentration in group 3 was significantly lower than that in group 1 or 2 (p<0.01). The duration of illness as acromegaly was significantly longer in group 2 and 3 as compared with group 1 (p<0.05). These results suggest that long-term stimulation by GH and insulin-like growth factor-I of thyroid follicular cells might be responsible for thyroid enlargement, presence of functioning lesions, slight overactivity of the thyroid, and the subsequent formation of multiple nodules in acromegalic patients. In conclusion, excluding two patients with thyroid cancer and one with Graves' disease, goiter was palpable in 39 of the 45 patients with acromegaly, among whom 14 (13 adenomatous goiters and 1 solitary cystic nodule) showed nodular enlargement.

Acromegaly↗
PubMedDate not supplied

Cytologic characterization of postiodization residual goiter in schoolchildren by fine needle biopsy.

OBJECTIVE: To determine the relevance and utility of fine needle biopsy (FNB) for providing a tissue-level diagnosis during a community-based survey of postiodization residual goiter in schoolchildren in India. STUDY DESIGN: A total of 14,762 schoolchildren (56.0% girls and 44.0% boys), aged 6-18 years, with a countrywide representation, were clinically screened for the presence of goiter. FNB was performed under field conditions by means of a nonaspiration technique from both lobes of goitrous glands. The cytologic diagnosis and findings were correlated with age, sex, goiter grade and biochemical parameters of serum T4, TSH, thyroid microsomal (TMA) and thyroglobulin (TGA) antibodies. RESULTS: The overall prevalence of goiter was 23.0%, with a greater frequency in girls (27.1%) than boys (17.8%). FNB was successful in 75.6% of subjects without any significant complications. The cytologic diagnoses in 1,312 successful cases were colloid goiter (92.8%), Hashimoto's thyroiditis (4.6%), focal lymphocytic thyroiditis (1.7%) and hyperplastic goiter (0.9%). Autoimmune thyroiditis (AIT), which accounted for only 6.3% cases, showed a strikingly different age-specific prevalence between girls and boys. Serologic markers of TMA and TGA at various titers were observed to lack requisite sensitivity and specificity for establishing an accurate diagnosis of AIT. CONCLUSION: The nonaspiration technique of FNB is capable of yielding valuable diagnostic information during an epidemiologic survey of goiter. The technique can be easily performed under field conditions on children without significant complications. FNB is preferable to serologic markers for accurate diagnosis of AIT. A relatively low frequency of AIT, as observed in the present study, raises the possibility of a significant role of environmental goitrogens as the underlying pathogenetic factor in postiodization residual goiter in Indian schoolchildren.

Adolescent↗
PubMed1978

Afrikander cattle congenital goiter: characteristics of its morphology and iodoprotein pattern.

The morphology and some properties of the complex iodoprotein pattern of the genetically determined congenital goiter in Afrikander cattle is described. The goiter contained irregularly shaped follicles which were devoid of colloid and the follicular epithelial cells were elongated, measuring about 20 micrometer in length compared to 10 micrometer for normal thyroid cells. The goiter cells contained apical clusters of larger and more numerous lysosomes than normal thyroid cells. Apical vesicles containing electron-dense material which were in contact with the plasma membrane could be seen in most normal thyroid cells, but were extremely scarce in the goiter. In 36 cell profiles studied none was found. The endoplasmic reticulum cisternae of the goiter differed significantly from normal thyroid cells. Fewer ribosomes were seen to be attached to the membranes of goiter cells. Furthermore, unlike normal thyroid cells, many free polysomes were seen in goiter cells. The characteristics of the unusual iodoprotein pattern of the goiter extract, resolved by gel chromatography and sucrose density gradient centrifugation, were qualitatively and quantitatively similar to that described previously (Endocrinology 91, 470, 1972). A relatively small amount of the total soluble protein was iodinated. Of these, only a 12S sedimenting species was precipitated by antithyroglobulin immunoglobulin. When separated on polyacrylamide gels containing sodium dodecyl sulfate and mercaptoethanol, this 12S species was resolved into at least 14 polypeptide components ranging in molecular weights from less than 66,000--330,000. Three of the bands, representing a small percentage of the total protein, seemed to comigrate with the major polypeptides of thyroglobulin and were also precipitated with rabbit antihyroglobulin immunoglobulin. The data indicate that glycosylation of iodoproteins was not affected although 19S thyroglobulin synthesis and subsequent storage were drastically impaired.

Animals↗