Utility of outpatient fractionated radioiodine therapy for Graves disease involving a large goiter measuring more than 100 mL in volume

Contrary to large multinodular goiters, reports on ¹³¹I radioiodine therapy (RIT) for Graves disease (GD) involving a large goiter are scarce. We retrospectively reviewed a total of 71 consecutive patients (25 males, 46 females) with GD involving a large goiter (>100 mL) who had received RIT in our clinic. Patients with a history of thyroid surgery or with large thyroid nodules and those who had dropped out less than one year after the initial RIT session were excluded. A fixed ¹³¹I activity of 481 MBq was administered in most cases. RIT was repeated at intervals of 1-47 months, typically 3-6 months. The follow-up duration after the initial RIT session was 13-233 (median: 81) months. The thyroid volume was estimated using ultrasound. The number of ¹³¹I doses were 1 dose in 13 patients, 2 doses in 29, 3 doses in 17, 4 doses in 5, 5 doses in 5, 6 doses in 1, and 8 doses in 1. Sixty-six patients had remission from overt hyperthyroidism after RIT: overt hypothyroidism in 45 patients, subclinical hypothyroidism or euthyroidism in 13, and subclinical hyperthyroidism in 8. Their thyroid volume decreased from 101-481 (median: 126) mL to 1.4-37 (8.2) mL. Three patients still had overt hyperthyroidism under treatment with methimazole after one to three doses, and two dropped out less than six months after the third or sixth dose. Even in GD patients with a large goiter (>100 mL), repeated RIT with an activity of 481 MBq could sufficiently shrink goiters and remit overt hyperthyroidism.

Thyroid Function of Infants Breastfed by Mothers with Graves Disease Treated with Inorganic Iodine: A Study of 100 Cases

Context

We previously reported that inorganic iodine therapy in lactating women with Graves disease (GD) did not affect the thyroid function in 25 of 26 infants despite their exposure to excess iodine via breast milk.

Objective

To further assess thyroid function in infants nursed by mothers with GD treated with inorganic iodine.

Design

Case series

Setting

Tajiri Thyroid Clinic, Japan

Participants

One hundred infants of lactating mothers with GD treated with potassium iodide (KI) for thyrotoxicosis

Main Outcome Measures

Infant blood thyrotropin (TSH) and free thyroxine (FT4) levels were measured by the filter paper method. Subclinical hypothyroidism was defined as TSH ≥10 μIU/mL and ≥5 μIU/mL in infants aged <6 and ≥6 months, respectively.

Results

Overall, 210 blood samples were obtained from 100 infants. The median infant age was 5 (range, 0-23) months; median maternal KI dose, 50 (4-100) mg/day; median blood TSH level, 2.7 (0.1-12.3) μIU/mL; and median blood FT4 level, 1.04 (0.58-1.94) ng/dL. Blood TSH level was normal in 88/100 infants. Twelve infants had subclinical hypothyroidism; among them, blood TSH levels normalized after maternal KI withdrawal or stopping breastfeeding in 3 infants. In 7 infants, blood TSH levels normalized during KI administration without stopping breastfeeding. Two infants could not be followed up.

Conclusion

In Japan, inorganic iodine therapy for lactating women with GD did not affect thyroid function in most of the infants. Approximately 10% of infants had mild subclinical hypothyroidism, but blood TSH level normalized during continued or after discontinuing iodine exposure in all followed up infants.

Long-Term Outcomes of Radioiodine Therapy for Juvenile Graves Disease with Emphasis on Subsequently Detected Thyroid Nodules: A Single Institution Experience from Japan

OBJECTIVE

To investigate the long-term outcomes of radioiodine therapy (RIT) for juvenile Graves disease (GD) and the ultrasonographic changes of the thyroid gland.

METHODS

All of 117 juvenile patients (25 males and 92 females, aged 10 to 18 [median 16] years) who had undergone RIT for GD at our clinic between 1999 and 2018 were retrospectively reviewed. Each RIT session was delivered on an outpatient basis. The maximum 131I dose per treatment was 13.0 mCi, and the total 131I dose per patient was 3.6 to 29.8 mCi (median, 13.0 mCi). 131I administration was performed once in 89 patients, twice in 26, and three times in 2 patients. Ultrasonography of the thyroid gland was regularly performed after RIT. The duration of follow-up after the initial RIT ranged from 4 to 226 (median 95) months.

RESULTS

At the latest follow-up more than 12 months after RIT (n = 111), the patients' thyroid functions were overt hypothyroidism (91%), subclinical hypothyroidism (2%), normal (5%), or subclinical hyperthyroidism (2%). New thyroid nodules were detected in 9 patients, 4 to 17 years after initial RIT. Patients with newly detected thyroid nodules underwent RIT with lower doses of 131I and had larger residual thyroid volumes than those without nodules. None of the patients were diagnosed with thyroid cancer or other malignancies during the follow-up period.

CONCLUSION

Over a median follow-up period of 95 months (range, 4 to 226 months), RIT was found to be effective and safe in juvenile GD. However, cumulative evidence from further studies is required to confirm the long-term safety of RIT for juvenile GD.

ABBREVIATIONS

ATD = antithyroid drug; GD = Graves disease; KI = potassium iodide; LT4 = levothyroxine; MMI = methimazole; PTU = propylthiouracil; RAIU = radio-active iodine uptake; RIT = radioiodine therapy; 99mTc = technetium-99m; TSH = thyrotropin.

Congenital Primary Hypothyroidism with the Homozygous Nonsense Mutation P.K1374* in the Thyroglobulin Gene and a Normal-sized Thyroid Gland on Levothyroxine Replacement

Thyroglobulin (TG) gene mutations cause thyroid dyshormonogenesis, which is typically associated with a congenital goiter. We herein report the case of a 64-year-old man with congenital primary hypothyroidism who had a normal-sized thyroid gland on levothyroxine replacement. He had short stature (-3.1 standard deviations) and mild intellectual impairment. Thyroid autoantibodies were all negative, and the serum TG levels were undetectable. Eventually, he was found to have the novel homozygous nonsense mutation p.K1374* in the TG gene. The possibility of TG mutation should be considered for patients with congenital primary hypothyroidism and a very low serum TG level, regardless of the thyroid size.

Effects of Inorganic Iodine Therapy Administered to Lactating Mothers With Graves Disease on Infant Thyroid Function

Context:

The effects of maternal inorganic iodine therapy on infant thyroid function are not well known.

Objective:

This study investigated the effects on infant thyroid function of maternal inorganic iodine therapy when administered to lactating mothers with Graves disease.

Design and Setting:

This study was a prospective case series performed at the Tajiri Thyroid Clinic, Kumamoto, Japan.

Participants:

Subjects were 26 infants of lactating mothers with Graves disease treated with potassium iodide (KI) for postpartum thyrotoxicosis.

Main Outcome Measures:

Infant blood levels of thyroid-stimulating hormone (TSH) and free thyroxine were measured using the dried filter-paper method. Iodine concentrations in breast milk and infant urine were measured on the same day. Subclinical hypothyroidism was defined as a blood TSH level of ≥10 or ≥5 μIU/mL in <6-month-old and 6- to 12-month-old infants, respectively.

Results:

The median age of the infants was 3 months (range, 0 to 10 months). The median KI dose was 50 mg/d (range, 10 to 100 mg/d). High median iodine concentrations were detected in breast milk (15,050 μg/L; range, 831 to 72,000 μg/L) and infant urine (15,650 μg/L; range, 157 to 250,000 μg/L). Twenty-five of 26 infants had normal thyroid function. Although one infant had subclinical hypothyroidism (blood TSH, 12.3 μIU/mL), the TSH level normalized to 2.3 μIU/mL at 2 months after KI discontinuation.

Conclusion:

In Japan, where iodine intake is sufficient, administration of inorganic iodine to lactating mothers with Graves disease did not affect thyroid function in most infants despite high levels of exposure to iodine via breast milk.

Painful Radiation Thyroiditis after 131I Therapy for Graves' Hyperthyroidism: Clinical Features and Ultrasonographic Findings in Five Cases

BACKGROUND

Radiation thyroiditis caused by ¹³¹I therapy for Graves' hyperthyroidism is asymptomatic in most patients and is rarely associated with pain or fever. Currently, there are few reports on the ultrasonographic findings of radiation thyroiditis after ¹³¹I therapy for Graves' hyperthyroidism.

CASE REPORT

We herein report 5 cases with painful radiation thyroiditis (including 2 febrile cases) after ¹³¹I therapy for Graves' hyperthyroidism. The cases included 4 women, aged 49, 50, 76, and 81 years, and 1 man, aged 60 years. Anterior neck pain developed 0-10 days after ¹³¹I administration (fixed dose of 481 MBq). Each patient visited our clinic 0-4 days after the development of anterior neck pain. The thyroid glands were noticeably enlarged (increasing from 18 g at ¹³¹I administration to 35 g after the development of anterior neck pain in 1 patient, and from 20 to 33 g, 21 to 39 g, 21 to 51 g, and 40 to 51 g in the other patients) and tender. The echogenicity of the thyroid parenchyma was increased, and the parenchyma was more heterogeneous. Granular hyperechoic lesions were scattered throughout the thyroid gland in the most severe case. The border between the thyroid gland and the surrounding tissue was blurred, and the surrounding tissue was hyperechoic.

CONCLUSION

Painful radiation thyroiditis should be reacknowledged as one of the complications of ¹³¹I therapy for Graves' hyperthyroidism. Ultrasonography demonstrated the characteristic changes caused by ¹³¹I-induced radiation thyroiditis.

Iodide Transport Defect and Breast Milk Iodine

BACKGROUND

Iodide transport defect (ITD) is a dyshormonogenetic congenital hypothyroidism caused by sodium/iodide symporter (NIS) gene mutations. In the lactating mammary gland, iodide is concentrated by NIS, and iodine for thyroid hormone synthesis is thereby supplied to the infant in the breast milk.

CASE DESCRIPTION

A 34-year-old Japanese woman was diagnosed with ITD caused by a homozygous NIS gene mutation T354P. She had begun treatment of primary hypothyroidism with levothyroxine at the age of 5. She delivered a baby at the age of 36. The iodine concentration in her breast milk was 54 µg/l. She took a 50-mg potassium iodide tablet daily to supply iodine in the breast milk, starting on the 5th day postpartum. Her breast milk iodine concentration increased to 90 µg/l (slightly above the minimum requirement level). The patient weaned her baby and stopped taking the daily potassium iodide tablet 6 weeks postpartum, and the baby began to be fed with relatively iodine-rich formula milk. The baby's thyroid function remained normal from birth until 6 months of age.

CONCLUSION

Possible iodine deficiency in the infant breast-fed by an ITD patient should be kept in mind. Prophylactic iodine supplementation is essential for such infants in order to prevent severe iodine deficiency.

FREQUENCY OF FLAME SENSOR ACTIVATION IN PUBLIC PLACES AFTER ADMINISTRATION OF RADIOACTIVE IODINE TO TREAT GRAVES DISEASE: A RECENT SURVEY

OBJECTIVE

Ultraviolet (UV)-perception-type flame sensors detect gamma rays emitted from iodine 131 ((131)I). Explaining the possibility of flame sensor activation to patients when they receive (131)I to treat Graves disease or other ablative purposes is important. We investigate the current situation of flame sensor activation after radioactive iodine (RAI) therapy.

METHODS

A total of 318 patients (65 males and 253 females) with Graves disease who received RAI therapy at our clinic between November 2007 and June 2014 participated in this study. Patients were given both written and oral explanations regarding the possibility of flame sensor activation. Participants were surveyed with a questionnaire. The following question was asked: "Did the fire alarm (flame sensor) go off when you used a restroom in places like shopping centers within a few days after your isotope therapy?" To those who answered "yes," we asked where the fire alarm had gone off.

RESULTS

Of the 318 patients, 19 (6.0%) answered "yes," 2 of whom were male while 17 were female. Of the 299 (94.0%) patients who answered "no," 63 were male and 236 were female. As to the place of restroom sensor activation, shopping centers were reported by 9 patients; supermarkets by 5; airports by 2; and a bookstore, the Kyushu Shinkansen (bullet train), and a hospital by 1 each.

CONCLUSION

Explaining to patients the possibility of flame sensor activation after RAI therapy is important to avoid some complications, especially in security-sensitive areas.

ABBREVIATIONS

(131)I = iodine 131 RAI = radioactive iodine UV = ultra-violet.

Development of Primary Thyroid Lymphoma during an Ultrasonographic Follow-up of Hashimoto's Thyroiditis: A Report of 9 Cases

We herein experienced 9 patients with primary thyroid lymphoma that developed during 3-18 years of ultrasonographic follow-up of Hashimoto's thyroiditis. All nine patients had localized mucosa-associated lymphoid tissue (MALT) lymphoma. Two patients had diffuse type, one had mixed type, and six had nodular type according to the ultrasonographic classification. A clearly enlarging goiter was observed before the diagnosis of lymphoma in 3 patients. An enlarging goiter was not apparent in the remaining 6 patients with nodular type lymphoma, however, the emergence or enlargement of a hypoechoic nodular lesion was observed. Thyroid MALT lymphoma may be diagnosed early by an ultrasonographic follow-up of Hashimoto's thyroiditis.

Hypoalbuminemia, influenza vaccination and other factors related to the development of pneumonia acquired outside hospitals in southern Japan: A case-control study

AIM

Pneumonia is the third largest cause of death in Japan. Pneumonia continues to be one of the most common causes of morbidity, hospitalization and mortality, especially in the elderly. The aim of the present study was to evaluate the factors related to the development of pneumonia acquired outside hospitals among the Japanese elderly.

METHODS

We carried out a hospital-based, case-control study. Cases were patients who had been newly diagnosed with pneumonia acquired outside hospitals. For each case, one to three controls were defined as outpatients with other diseases (not pneumonia) at the same hospitals. All participants (i.e. 50 cases and 110 controls) were aged 65 years and older.

RESULTS

Compared with control participants, hypoalbuminemia (<3.5 g/dL) and low body mass index (<18.0) were more common in pneumonia patients, whereas the proportion of those who could go out by themselves (i.e. self-support in activities of daily living) and the vaccination rate of seasonal influenza were lower in patients with pneumonia than control participants. Even after controlling for age, sex, hospital and aforementioned four factors, hypoalbuminemia (OR 9.19, 95% CI 3.70-22.81) increased the risk of pneumonia, whereas seasonal influenza vaccination (OR 0.37, 95% CI 0.16-0.85) reduced the risk. Even after excluding those who lived in a nursing home, hypoalbuminemina (OR 12.19, 95% CI 4.29-34.63) increased the risk of pneumonia.

CONCLUSIONS

Hypoalbuminemia might be a risk factor for pneumonia among the elderly living in the community.

Onset of reversible flaccid quadriplegia during treatment of thyrotoxic crisis

Two unrelated women were hospitalized for thyrotoxic crisis complicated by multiple organ failure. Both patients were treated with antithyroid drugs and hydrocortisone, as well as insulin for hyperglycemia, and underwent mechanical ventilation with sedation. Flaccid quadriplegia became apparent after each patient completely recovered their level of consciousness once sedation was discontinued on days 6 and 15, respectively. Three to six months of rehabilitation was required for the muscle strength to fully improve in both cases. Thyrotoxicosis in addition to critical illness polyneuromyopathy and the administration of glucocorticoid therapy may have contributed to the onset of quadriplegia in these two cases. Flaccid quadriplegia is one of the serious neuromuscular conditions experienced during the treatment of thyrotoxic crisis.

A simplified pull-through angioplasty technique without a snare device. A technical note

The pull-through angioplasty technique allows stable wire tension and stabilization of the device during the procedure. In this technique, a guide wire is passed from one sheath to another, usually with the aid of a snare device. We describe the treatment of occlusive subclavian artery disease and lesion at the origin of the vertebral artery employing a brachiofemoral pull-through technique without using a snare device. In this technique, the guide wire is advanced from the femoral artery to the brachial artery. The guide wire is directly inserted into the sheath placed at the brachial artery. The brachial artery is compressed proximal to the point of sheath insertion to prevent bleeding. The sheath is extracted temporally and the guide wire is caught outside of the body. The sheath is then introduced again through the guide wire. We used the pull-through technique without a snare device in seven cases, and we were able to build the pull-through system in six of these cases without a snare device. This pull-through technique without a snare device is not difficult to use, and may reduce the time and cost of angioplasty procedures.

Simultaneous occurrence of type 1 diabetes mellitus and Graves' disease: a report of two cases and a review of the literature

Two unrelated Japanese women, 41 and 27 years of age, were admitted with histories of thirst, weight loss and palpitations of a few weeks' duration. Both were diagnosed to have diabetic ketosis or ketoacidosis with acute-onset type 1 diabetes (T1D) and Graves' disease (GD) (autoimmune polyglandular syndrome type 3 variant; APS3v), and were treated with intensive insulin therapy and anti-thyroid drugs. Human leukocyte antigen examinations showed that both cases had the HLA-A2, A24, B54, and DRB1*04:05-DQA1*03:03-DQB1*04:01 haplotype, which made them susceptible not only to APS3v, but also to both acute-onset T1D and GD. The genetic background of patients strongly contributes to the simultaneous occurrence of T1D and GD.

Isolated adrenocorticotropin deficiency associated with painless thyroiditis: a case report and review of the literature

A 53-year-old Japanese man was admitted with a 3-month history of transient headache followed by general fatigue and weight loss. He had a history of ocular myasthenia gravis which had been in remission following thymectomy 30 years ago. He had a small diffuse goiter without tenderness, and was diagnosed as having painless thyroiditis with mild thyrotoxicosis on admission. Endocrinological studies showed he had isolated adrenocorticotropin deficiency. Magnetic resonance imaging of the pituitary gland revealed no abnormalities. His symptoms improved soon after replacement of glucocorticoid. After an episode of hypothyroidism, he spontaneously became euthyroid. It is likely that thyrotoxicosis uncovered adrenal insufficiency that had developed insidiously, and hypoadrenocorticism-induced immunological changes may have triggered the development of painless thyroiditis. Moreover, thymectomy might have facilitated the development of pituitary and thyroid autoimmunity.

Bulk- and surface-sensitive high-resolution photoemission study of two mott-hubbard systems: SrVO3 and CaVO3

We study the electronic structure of Mott-Hubbard systems SrVO3 and CaVO3 with bulk and surface-sensitive high-resolution photoemission spectroscopy, using a vacuum ultraviolet laser, synchrotron radiation, and a discharge lamp (hv = 7-21 eV). A systematic suppression of the density of states (DOS) within approximately 0.2 eV of the Fermi level (EF) is found on decreasing photon energy, i.e., on increasing bulk sensitivity. The coherent band in SrVO3 and CaVO3 is shown to consist of surface and bulk-derived features, separated in energy. The stronger distortion on surface of CaVO3 compared to SrVO3 leads to a higher surface metallicity in the coherent DOS at EF, consistent with recent theory.

Stress and thyroid autoimmunity

While many studies have shown a connection between stress and autoimmune disease, most of the evidence for stress contributing to the onset and course of autoimmune disease is circumstantial and the mechanisms by which stress affects autoimmune disease are not fully understood. The best circumstantial evidence for an effect of stress on autoimmune thyroid disease is the well-known relationship between the onset of Graves' hyperthyroidism and major stress but even this is debated. However, most of the recent case-control studies have supported stress as a factor that affects the onset and clinical course of Graves' disease. On the other hand, there have been few reports concerning the possible relationship between stress and Hashimoto's thyroiditis. Because the onset and course of Hashimoto's thyroiditis is generally insidious, the effect of stress on Hashimoto's thyroiditis might be overlooked. Numerous human and animal studies have demonstrated that psychological and physiologic stressors induce various immunologic changes. Stress affects the immune system either directly or indirectly through the nervous and endocrine systems. These immune modulations may contribute to the development of autoimmunity as well as the susceptibility to autoimmune disease in genetically predisposed individuals. Stress can be one of the environmental factors for thyroid autoimmunity.

Eye muscle antibodies in Graves' ophthalmopathy: pathogenic or secondary epiphenomenon?

The extra ocular (eye) muscles are one of the principal tissues involved in the autoimmune-mediated inflammation of Graves' ophthalmopathy (GO). Several eye muscle proteins are targeted by autoantibodies or sensitized T lymphocytes, or both, and include: G2s, which is now identified as the terminal 141 amino acids of the winged-helix transcription factor FOXP1, the flavoprotein (Fp) subunit of the mitochondrial enzyme succinate dehydrogenase, the so-called "64kDa protein", a non-tissue specific membrane protein called 1D and the calcium binding protein calsequestrin. Of these, antibodies against G2s and Fp are the most sensitive markers of eye muscle damage in patients with thyroid autoimmunity even though neither antigen is specific to eye muscle and neither antibody is specific to GO. However, the recent finding that the calsequestrin gene is 4.7 times more expressed in eye muscles than other skeletal muscles suggests that we should reconsider the possible role of anti-calsequestrin autoantibodies in ophthalmopathy. GO may comprise two main subtypes with different pathogenetic mechanisms, namely ocular myopathy in which eye muscle inflammation predominates and congestive ophthalmopathy where inflammatory changes occur in the periorbital connective tissues in the absence of eye muscle dysfunction. Anti-G2s and anti-Fp antibodies are closely associated with the ocular myopathy subtype of GO while antibodies targeting type XIII collagen, the only member of the collagen family to have a transmembrane domain, are closely linked to congestive ophthalmopathy. Since both G2s and Fp are intracellular antigens it is unlikely that either antibody causes eye muscle fiber damage in GO, although a role in the later stages of the disease when the fiber has released its cellular contents has not been excluded. Eye muscle antibodies that are cytotoxic to eye muscle cells in antibody-dependent cell-mediated cytotoxicity (ADCC) are more likely to play a role in eye muscle fiber damage since they target a putative eye muscle cell membrane antigen, the identity of which is currently being investigated. While anti-G2s and anti-Fp antibodies are probably secondary to an underlying reaction, such as cytotoxic T lymphocyte targeting of an eye muscle membrane antigen that has yet to be identified, they are reliable markers of immunologically mediated eye muscle fiber damage in patients with Graves' hyperthyroidism. In conclusion, while a pathogenic role for eye muscle antibodies has not been excluded, they are most likely secondary to cytotoxic T cell reactions in GO and, as such, good markers of this autoimmune disease.

Effect of preincubation of cryopreserved porcine epididymal sperm

Preincubation of spermatozoa is important for capacitation and successful fertilization in vitro. The effects of preincubation time on frozen-thawed boar epididymal spermatozoa as measured by sperm motility, acrosomal integrity and fertilization ability in vitro were examined. Epididymal spermatozoa were collected from three Large White boars and frozen. The thawed spermatozoa were preincubated for 0, 15, 30, 60 and 120 min. Their motility was evaluated by a sperm motility analyzer and then the sperm motility indexes (SMIs) were calculated. The status of their acrosomal integrity was evaluated by triple-staining. Then, their fertilization ability was examined by in vitro fertilization (IVF) using porcine oocytes matured in vitro. SMIs of spermatozoa and the incidences of acrosome-intact live spermatozoa from the three boars were high (21-39 for SMI and 50-61% for acrosome-intact live spermatozoa) just after thawing, but both decreased as the duration of preincubation was prolonged (2-10 and 23-40%, respectively). The incidences of sperm penetration were high (61-89% of inseminated oocytes) when the sperm were preincubated for 0-60 min. However, sperm penetration decreased as the preincubation period was prolonged to 120 min. The degree of this decrease differed depending upon the boar from which the spermatozoa were obtained (10-72%). When the two parameters, sperm motility and acrosomal integrity, were analyzed statistically, the latter parameter rather than the former one showed a significant effect on penetration ability in vitro after each duration of preincubation. These results suggest that preincubation of frozen-thawed boar epididymal spermatozoa is not required for IVF and also that the maintenance of acrosomal integrity in unreacted status, rather than the maintenance of sperm motility, is important for fertilization ability after thawing and during preincubation of boar epididymal spermatozoa.

Multiple intracranial recurrent tumors with hyperprolactinemia combined with a parasellar malignant fibrous histiocytoma long after transfrontal surgery and irradiation to a pituitary adenoma

We herein describe a 40-year-old woman with hyperprolactinemia, an empty sella and two extrasellar intracranial recurrent tumors which were revealed 23 years after the first transfrontal craniotomy and 18 years after the second transfrontal surgery and irradiation to a provable prolactin-producing pituitary macroadenoma. One recurrent tumor was in the right orbital apex causing right oculomotor nerve palsy, and the other tumor was in the right apex partispetrosae and foramen jugulare. Although her serum prolactin level decreased after the administration of bromocriptine mesilate, and the size of the two tumors remained unchanged, a malignant fibrous histiocytoma, which might have been induced by the irradiation 18 years before, grew rapidly in the right suprasellar-prepontine cistern to the right pedunculus cerebralis, leading to a poor prognosis. This case confirmed the importance of the life-lasting follow-up of pituitary adenomas treated with surgery and/or irradiation therapy. Not only ectopic recurrence of the primary tumor but also post-irradiation tumors may become apparent long after the removal of the primary tumor.

Increased sensitivity to thyroid hormone replacement therapy followed by hyponatremia and eosinophilia in a patient with long-standing young-onset primary hypothyroidism

We describe a 51-year-old woman with long-standing young-onset primary hypothyroidism. Serum cortisol, adrenocorticotropin, and arginine vasopressin levels were normal, but urinary excretion of 17-hydroxycorticosteroid was decreased. Administration of a very small initial dose of thyroid hormone induced severe acute complications including fever, palpitation, and sweating associated with a rapid decrease in serum thyrotropin level, a dramatic increase in serum alkaline-phosphatase level, and a decrease in serum total cholesterol level. A week later, the late complications of nausea, severe hyponatremia, and eosinophilia occurred. Serum cortisol level decreased slightly but remained within normal limits during this hyponatremic period. This rare case suggests that increased sensitivity to thyroid hormone can occur in long-standing primary hypothyroidism with biphasic clinical course of acute thyrotoxic complications followed by severe hyponatremia resembling hypoadrenocorticism.

Usefulness of surface phenotype study of intrathyroidal lymphocytes obtained by fine needle aspiration cytology in autoimmune thyroid disease and malignant lymphoma of the thyroid

OBJECTIVES

The surface phenotypes of intrathyroidal lymphocytes have been studied in various thyroid diseases. In most of the previous reports, intrathyroidal lymphocytes were obtained by surgical operation. We evaluated the usefulness of surface phenotype study of intrathyroidal lymphocytes obtained by fine needle aspiration in the diagnosis of Graves' disease, chronic thyroiditis, and malignant lymphoma of the thyroid.

PATIENTS AND DESIGN

Eighty-seven untreated patients including 24 with Graves' disease, 59 with chronic thyroiditis, and 4 with malignant lymphoma of the thyroid, and 2 treated patients with malignant lymphoma of the thyroid were studied. Surface phenotypes of the peripheral lymphocytes and the intrathyroidal lymphocytes obtained by fine needle aspiration were analyzed using a FACScan and the monoclonal antibodies: anti-Leu5b/CD2, Leu4/CD3, Leu3a/CD4, Leu2a/CD8, and Leu12/CD19. Percentages of cells positive for each monoclonal antibody were calculated. In one case with malignant lymphoma, monoclonal antibodies to surface-immunoglobulin markers were also studied.

RESULTS

In peripheral lymphocytes, the percentage of positive cells in each phenotype was almost normal in each disease. In intrathyroidal lymphocytes, the percentage of CD19 positive cells was increased, and the percentage of CD2 and CD3 positive cells was reduced compared to those of peripheral lymphocytes in each disease. The percentage of intrathyroidal CD19 positive cells was remarkably high in malignant lymphoma, constituting more than 70% of cells. In Graves' disease, a relative decrease in the percentage of intrathyroidal CD4 positive cells and an increase in CD8 positive cells compared to peripheral lymphocytes were observed. In 2 treated patients with malignant lymphoma of the thyroid, the intrathyroidal CD19 positive cells almost disappeared in a patient shortly after successful treatment, and reappeared to constitute 76% of cells in a patient in relapse. In one case with malignant lymphoma in which monoclonal antibodies to surface-immunoglobulin markers were studied, the clonality of the affected cells could be demonstrated; more than 70% of the cells were positive for kappa light-chain and mu and delta heavy-chain. This finding was proved by subsequent immunohistochemical study based on open biopsy.

CONCLUSIONS

Surface phenotype study of intrathyroid lymphocytes obtained by fine needle aspiration has limited utility in the evaluation or diagnosis of Graves' disease and chronic thyroiditis. However, this simple rapid method is very helpful in the diagnosis and follow up of malignant lymphoma of the thyroid.

Localized painful giant-cell thyroiditis without inflammatory signs in a euthyroid patient followed by serial sonography

We describe a patient with localized painful giant-cell thyroiditis. A 45-year-old woman noticed a tender lump in the left side of the neck. Sonography of the thyroid revealed diffuse swelling of the left lobe with irregular hypoechoic areas. Three months later, the tender swelling subsided, and the hypoechoic areas disappeared without any treatment. There were never any systemic signs of inflammation or thyroid dysfunction. Atypical localized subacute thyroiditis was considered to be the most probable diagnosis based on fine-needle aspiration cytology and serial sonography. Serial sonographic evaluations are useful to avoid unnecessary surgery.

Familial isolated hyperparathyroidism due to multiple adenomas associated with ossifying jaw fibroma and multiple uterine adenomyomatous polyps

We describe three siblings with hyperparathyroidism due to multiple parathyroid adenomas without evidence of other endocrinological abnormalities. A 22-year-old woman had two parathyroid adenomas complicated by multiple ossifying jaw fibromas. Her sister, aged 29, also suffered from primary hyperparathyroidism associated with two parathyroid adenomas one of which was also suspected to be a carcinoma. These two female patients had unusual multiple small uterine polyps, which were diagnosed as adenomyomatous polyps. Their brother, aged 17, had two parathyroid adenomas complicated by urolithiasis. These three patients are characterized by young adult-onset familial isolated hyperparathyroidism due to multiple adenomas with various complications including ossifying jaw fibroma and uterine adenomyomatous polyps. These clinical features are different from those of familial hyperparathyroidism associated with multiple endocrine neoplasia.

Anaplastic transformation of a papillary carcinoma of the thyroid in a patient with Graves' disease with varied activity of thyrotropin receptor antibodies

We describe a 75-year-old man who had had a lump in his neck for about 15 years. At his first visit to our hospital, poorly differentiated papillary carcinoma of the thyroid was diagnosed by means of aspiration cytology; x-rays revealed the presence of lung metastases. He was thyrotoxic with positive thyroid stimulating antibody (TSAb). He was reluctant to undergo surgery. In an early stage of the treatment for Graves' disease, he became hypothyroid with decreased TSAb activity and strongly positive thyroid stimulation blocking antibody (TSBAb), and rapid growth of the thyroid carcinoma with anaplastic transformation was observed. The increase in the size of the transformed thyroid carcinoma was shown to be exponential by ultrasonography. This is a rare case in which anaplastic transformation of the thyroid papillary carcinoma became apparent during treatment of Graves' disease with varied activity of thyrotropin receptor antibodies.

Studies on the effects of the spillway on the occlusal table of complete dentures upon the bearing of masticatory force

We studied the effect of spillways in the posterior artificial teeth of complete dentures in reducing masticatory pressure on the basal mucosa by making completely edentulous patients masticate food. Using two kinds of experimental dentures, one with spillways on the occlusal table and the other without, five subjects wearing complete dentures were instructed to masticate four different types of test food. The results showed that the mastication time and the number of masticatory strokes were not much affected by the existence of spillways. However, the masticatory force of artificial teeth with spillways was slightly smaller than that of artificial teeth without spillways.

Condylar surface forms in edentulous patients: examination findings

The incidence of abnormal condylar surface forms was assessed by zonograms on edentulous patients who visited this department with various chief complaints other than temporomandibular disorder. The relation between these abnormal condylar surface forms and the conditions involved in the manifestation of the abnormalities was studied. Abnormal condylar surface forms were observed in 71% of the subjects. Bilateral abnormalities were found in 66% of these subjects: These abnormalities were classified into four types: erosion, flattening, osteophyte, and concavity. Those with erosion showed the highest incidence at 60.6%. The incidence of abnormal condylar surface forms was significantly higher in patients over 70 years old and/or in unstable denture wearers.

Difficulty in differentiating thyrotropin secreting pituitary microadenoma from pituitary-selective thyroid hormone resistance accompanied by pituitary incidentaloma

A 33-year-old woman with inappropriate secretion of TSH and a 2-mm pituitary microadenoma is described. She had a high serum free T4 concentration (31 pmol/L) with an inappropriately nonsuppressible serum TSH concentration (0.93 mU/L). The alpha/TSH molar ratio was 2.3 and magnetic resonance imaging with gadolinium enhancement identified an area of low signal intensity in the left lateral pituitary gland. However, TSH secretion was not completely autonomous. There was a significant response to exogenous TRH stimulation and suppression by T3 administration. Therefore, it was difficult to rule out a nonfunctioning pituitary adenoma with concomitant pituitary selective thyroid hormone resistance syndrome. A 2-mm microadenoma was excised via transsphenoidal surgery. The tumor cells were immunoreactive to antisera to alpha-subunit and minimally immunoreactive to antisera to TSHbeta. The patient's thyroid function normalized after surgery without medication. Because the adenoma could become large and intractable if the patient was treated inadequately, early diagnosis and treatment are important in patients with TSH secreting adenomas.

Fundamental study of the relationship between the lateral mandibular position and the bulging of the temporal muscle region

Greene proposed a temporal-muscle-gripping method to judge the suitability of the mandibular position by gripping the temporal muscle region. Ogiwara examined the relationship between the anteroposterior mandibular position and the bulging of the temporal muscle region. However, the relationship between the lateral mandibular position and the bulging of the temporal muscle region has not been clarified. In this study, the relationship between the lateral mandibular position and the bulging of the temporal muscle region was examined. Five dentulous subjects were required to occlude at the tapping point and laterally deviated mandibular positions from the tapping point. The bulging of the temporal muscle region was measured at each mandibular position. Results were as follows. The bulging of the temporal muscle region at occlusion was influenced by lateral deviations in the mandibular position. The bulging was larger and started earlier on the deviated side than on the opposite side. In the measurement of the starting time of bulging of the temporal muscle region, the value of the difference in the starting time of bulging between the right and the left side at more than 0.4 mm lateral deviated mandibular position was larger than the value of the difference in the starting time of bulging between the right and the left side at the tapping point in all five subjects (p < 0.05).

Immunological and chemical types of reversible hypothyroidism; clinical characteristics and long-term prognosis

OBJECTIVE

Spontaneous improvement occurs in about one-half of patients with primary hypothyroidism who reside in an iodine-sufficient area of Japan, but the pathogenetic factors related to reversible hypothyroidism are still not fully understood. We therefore investigated the clinical features and prognosis of patients with reversible hypothyroidism with or without iodine excess and antithyroid antibodies.

DESIGN

Amelioration of hypothyroidism was diagnosed when the elevated serum TSH concentrations (serum TSH concentration > or = 40 mU/l) decreased by 50% or more during an iodine restriction period of 2-15 weeks without replacement therapy. Reversible hypothyroidism occurred in a post-partum group (n = 20) and a non-post-partum group (n = 91). The latter was then further classified into chemical (n = 28), immunological (n = 20), and mixed (n = 43) groups, according to the presence of iodine excess (serum non-hormonal iodine level > 50 micrograms/l or a history of excess iodine ingestion), antithyroid autoantibody, or both, respectively.

MEASUREMENTS

Clinical characteristics and long-term prognosis were compared among the four groups. The rate at which hypothyroidism recovered was expressed as the number of days required for a 50% decrease in the serum TSH concentration. The level of thyroid echogenicity was measured by 10-MHz ultrasonography.

RESULTS

In the chemical group, the mean age, male:female ratio, and serum non-hormonal iodine concentrations were all higher than those in the immunological group. The estimated rate at which hypothyroidism recovered was rapid (6.1 +/- 3.1 (mean +/- SD) days), the levels of thyroid echogenicity were near normal, and a histological examination (n = 7) revealed either colloid goitre or a normal thyroid in the chemical group. In the immunological and post-partum groups, the recovery rate was slow (16.8 +/- 9.6 days and 16.2 +/- 5.8 days, respectively). The levels of thyroid echogenicity were markedly reduced but increased after the spontaneous recovery of the thyroid function in both groups. Aspiration cytology suggested lymphocytic infiltration in all patients examined in the immunological (n = 6) and post-partum groups (n = 4). Relapse to overt hypothyroidism was observed more frequently in the immunological (38%) and mixed groups (35%) than in the chemical group (5%).

CONCLUSION

Thyroid damage was more severe, recovery slower and the rate of relapse higher in the immunological than in the chemical type of reversible hypothyroidism.

Risk factors for brain infarction in patients with Cushing's disease. Case reports

Two women aged 51 and 52 years old, respectively, developed a brain infarction before and after undergoing treatment for Cushing's disease. A biochemical remission was obtained more than ten years after the onset of signs or symptoms of Cushing's disease. The arteriosclerotic changes of the cerebral vessels progressed even during replacement therapy for posttreatment hypopituitarism after they underwent either ablative surgery or radiotherapy. One patient, who showed the signs of Nelson's syndrome, demonstrated severe progressive cerebrovascular sclerotic changes, especially around the irradiated site. It is thus suggested that hypercortisolemia, external pituitary irradiation, and posttreatment hypopituitarism may be risk factors for brain infarction. The early diagnosis and adequate treatment are therefore important to prevent cerebrovascular complications in patients with Cushing's disease.

Reversible primary hypothyroidism with blocking or stimulating type TSH binding inhibitor immunoglobulin following recombinant interferon-alpha therapy in patients with pre-existing thyroid disorders

OBJECTIVE

Treatment with recombinant interferon-alpha (rIFN-alpha) may induce autoimmunity. We have evaluated the effect of rIFN-alpha on pre-existing thyroid disease with special reference to changes in TSH receptor antibody.

DESIGN AND PATIENTS

Five patients, who had a history of autoimmune thyroid disease diagnosed between 2 and 16 years earlier (three patients had Graves' disease while two had Hashimoto's thyroiditis), were treated with rIFN-alpha for chronic hepatitis C. Before, during and after rIFN-alpha therapy, we determined thyroid function, antithyroid antibody, thyroid echogenicity and the surface phenotype of the peripheral and intrathyroidal lymphocytes.

RESULTS

Four of the patients developed overt hypothyroidism after 4-7 months of rIFN-alpha therapy, and two of them had a preceding history of low-uptake thyrotoxicosis. Recovery of thyroid function was observed in all four patients. Strongly positive blocking type TSH receptor antibody was detected and an increase in the percentage of CD19 positive cells in the intrathyroidal lymphocytes was also observed in three of the patients even though the goitre size increased in two of them. One of the patients became thyrotoxic later when stimulating type TSH receptor antibody became positive. Another patient suffered from reversible hypothyroidism although stimulating type TSH receptor antibody remained strongly positive throughout the clinical course.

CONCLUSIONS

Our data thus indicated a high incidence of an unusual type of reversible hypothyroidism with TSH receptor antibodies in patients with chronic hepatitis C and pre-existing autoimmune thyroid disease after recombinant interferon-alpha therapy through a mechanism involving both the humoral and cellular immune systems.

Acute exacerbation of masked hyperthyroidism after iodine restriction followed by thyrotoxic atrial fibrillation and cerebral embolism. A case report

The authors present a seventy-two-year-old woman complaining of diffuse and firm goiter. At the first visit, she looked almost euthyroid with regular pulse rate of 78 per minute. After iodine restriction, however, she became severely thyrotoxic and developed cerebral embolism associated with atrial fibrillation due to Graves' hyperthyroidism. In conclusion, sudden withdrawal of dietary iodine might lead to exacerbation of Graves' hyperthyroidism resulting in serious cardiovascular or cerebrovascular complications, especially in elderly patients.

Hypopituitarism associated with transient diabetes insipidus followed by an episode of painless thyroiditis in a young man

A 16-year-old male complained of a headache and a high fever followed by polyuria. The endocrinological studies showed he had hypopituitarism and central diabetes insipidus, and magnetic resonance imaging (MRI) revealed a pituitary mass. Diabetes insipidus gradually improved and hydrocortisone treatment was begun at three months after onset, but a month later painless thyroiditis developed. An MRI demonstrated a spontaneous shrinkage of the pituitary mass nine months after onset. Lymphocytic hypophysitis followed by painless thyroiditis was the most probable diagnosis, although it is very uncommon especially among men.

Acute spontaneous hemorrhagic degeneration of the thyroid nodule with subacute thyroiditis-like symptoms and laboratory findings

Seventeen consecutive patients (3 men and 14 women, aged 14-75 years) with a hemorrhagic degeneration of the thyroid nodule, which was confirmed by both ultrasonography and either reddish or brown fluid evacuated by fine-needle aspiration, were classified as either acute type with an episode of abrupt painful swelling of the thyroid (n = 4), or chronic type in which a painless thyroid nodule was incidentally found (n = 13). One of the four acute type patients demonstrated subacute thyroiditis-like symptoms and laboratory findings including transient painful thyrotoxicosis associated with high serum levels of thyroid hormones and thyroglobulin (Tg), a suppressed serum TSH level, a low thyroidal radioactive iodine uptake (RAIU), and accelerated erythrocyte sedimentation rate (ESR). In the other three acute type patients the serum level of Tg increased markedly, the serum thyroid hormones level increased in one, the thyroidal RAIU was low in two, and the ESR was accelerated in one. In the thirteen chronic type patients, the serum levels of the thyroid hormones and the thyroidal RAIU were within the normal range, and few inflammatory signs were observed. These findings suggest that acute hemorrhagic degeneration of the thyroid nodule may thus cause transient subacute thyroiditis-like symptoms and laboratory findings.

Human T-lymphotropic virus type I-associated uveitis in patients with Graves' disease treated with methylmercaptoimidazole

Human T-lymphotropic virus type I (HTLV-I) is responsible for a certain form of uveitis [HTLV-I-associated uveitis (HAU)]. A previous history of Graves' disease has been reported in 9-17% of the patients with HAU. In this study, the prevalence of patients with either HTLV-I antibody or uveitis was evaluated in 819 consecutive patients with thyroid disorders between 1991 and 1992. Serum HTLV-I antibody was found in 25 of 392 patients with Graves' disease, 19 of 257 with chronic thyroiditis, and 3 of 170 with nodular goiter. Five of 25 HTLV-I-positive patients with Graves' disease developed HAU. All of these 5 patients had been treated with methylmercaptoimidazole (MMI). Within a few months before the onset of uveitis, 3 patients were hyperthyroid, and 2 were hypothyroid. In 2 of 5 patients, an exacerbation of uveitis occurred soon after the readministration of MMI for the relapse of hyperthyroidism. None of the 367 HTLV-I negative patients with Graves' disease nor 22 HTLV-I-positive patients with chronic thyroiditis or nodular goiter developed uveitis. It was therefore suggested that Graves' disease, thyroid dysfunction and/or MMI administration might be related to the development of HAU.

Postpartum exacerbation of HTLV-I associated myelopathy/tropical spastic paraparesis followed by an episode of painless thyroiditis

A 28-year-old woman noticed a progressive gait disturbance after her first delivery. At the age of 32, the gait disturbance improved during her second pregnancy, but became worse after delivery and eventually resulted in a scissoring gait. At the age of 34, she became transiently thyrotoxic and was diagnosed as having painless thyroiditis and HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). The findings of this case suggest that the postpartum exacerbation of HAM/TSP was probably due to a rebound phenomenon after immunosuppression during pregnancy, and that the immunological abnormalities associated with HAM/TSP might have played some role in the development of painless thyroiditis.

[A case of Bacillus cereus prosthetic valve endocarditis]

A rare case of prosthetic valve endocarditis by Bacillus cereus was reported. The patient was 43-year-old Japanese man, who had mitral valve replacement 5 months prior to this admission. Remitral valve replacement was immediately done successfully. His postoperative course was uneventful for 8 months.

A high prevalence of human T-lymphotropic virus type I carriers in patients with antithyroid antibodies

Human T-lymphotropic virus type I (HTLV-I) is a causative retrovirus of adult T-cell leukemia lymphoma and HTLV-I associated myelopathy/tropical spastic paraparesis. HTLV-I is also associated with some forms of pulmonary alveolitis, chronic arthropathy, polymyositis, and uveitis. In this study, the possible role of HTLV-I infection in the pathogenesis of autoimmune thyroid diseases with positive antithyroid antibody (ATA) to microsomal antigen or thyroglobulin was evaluated. In Fukuoka Prefecture or the northern part of Kyushu Island located in the southwestern part of Japan, the prevalence of patients with HTLV-I antibody was screened using the particle agglutination test and then was further confirmed either by the indirect immunofluorescence method or the western blot method. The observed prevalence in patients with thyroid disorders and the estimated prevalence calculated considering the sex- and age-specific prevalence among healthy blood donors (n = 16,008) were as follows: 19 (7.4%) vs 7.8 (3.0%) (p < 0.001) for ATA-positive chronic thyroiditis (n = 257), 21 (7.0%) vs 6.6 (2.2%) (p < 0.001) for ATA-positive Graves' disease (n = 298), 4 (4.3%) vs 2.1 (2.2%) (ns) for ATA-negative Graves' disease (n = 94), 1 (2.9%) vs 1.1 (3.1%) (ns) in ATA-negative hypothyroidism (n = 35), and 3 (1.8%) vs 5.0 (2.9%) (ns) for ATA-negative nodular goiter (n = 170). These findings thus suggest that HTLV-I infection may have some relationship to ATA-positive thyroid disorders.

A study of the judging the anteroposterior mandibular position by gripping the temporal muscle region

Greene proposed a method for judging the suitability of the mandibular position from the bulging of the temporal muscle. Using his method, we studied the effect of anteroposterior alteration of mandibular position on the building of this muscle. In the temporal muscle, the area suitable for gripping to check mandibular position was, anteroposteriorly, the point 3/5 of the length between the upper margin of the external auditory meatus and the point of intersection of the Frankfort plane and the line perpendicular to it which was drawn from the outer canthus. Vertically, it was approximately at the point 3/5 of the distance from the bottom of the line from the Frankfort plane to the upper edge of the temporal muscle. In patients whose anteroposterior changes in the tapping point were small, anteroposterior changes of 0.2 mm in mandibular position could be detected. However, in patients who had large anteroposterior changes in the tapping point, anteroposterior changes of 0.5 mm in mandibular position could not be verified.

A study of the influence of arrangement of upper posterior artificial teeth on pronunciation: Japanese sounds articulated on the posterior palate

To clarify the standard of bucco-lingual tooth arrangement in complete denture construction, the influence of the bucco-lingual position of upper posterior artificial teeth on pronunciation was investigated. Wearing 7 kinds of experimental artificial teeth with the upper posterior ones arranged in 7 different positions, patients pronounced 5 test sounds: "ka", "ki", "kw", "ke" and "ko". Resultant sounds were evaluated in terms of how the bucco-lingual position of posterior artificial teeth influenced pronunciation as determined with by aural pronunciation judgment test and frequency analysis using a 1/3 octave-band real-time analyzer. Pronunciation disorders caused by the arrangement of the upper posterior artificial teeth in complete dentures occur when the lingual surfaces of the upper molars is located more than 1/4 inward of the distance between the right and left denture border from the buccal denture border or less than 1/10 of that distance outward from the buccal denture border. Results of the aural pronunciation judgment test indicated that the influence of the arrangement of the upper posterior artificial teeth on pronunciation depends on the vowel following the consonant of the sound. When the vowel following the consonant is a back vowel, as in "ka", "kw" and "ko" the sound was barely influenced, but when the vowel is a front vowel. as in "ke" and "ki", the sound was markedly influenced. We established the frequency spectrum of the consonant of the normally pronounced 5 test sounds as the standard frequency spectral range and compared distorted and misheard sounds with it.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between impression method of mucosa-borne area and denture pressure supportability

In order to develop a more rational impression method, we examined the relationship between impression method and denture pressure supportability through the denture. Measured with denture bases prepared from impressions taken under various pressures, pressure supportability generally increased with increasing impression pressure. However, the pressure supportability of a denture base prepared from a slight-pressure impression taken under minimum pressure was greater in some cases than for a middle-pressure impression performed under a more pressure. The impression pressure required to produce maximum pressure supportability were calculated based on the area projected from the occlusal plane and ranged from 1.24 to 2.44 kg/cm2 (0.12 to 0.24 MPa). Values calculated based on the surface area of the denture-supporting mucosa ranged from 0.83 to 2.48 kg/cm2 (0.08 to 0.24 MPa). Pressure supportability of the great-pressure impression was 1.3 to 2.6 times higher than that of the slight-pressure impression and 1.2 to 1.8 times greater than that of the alginate impression. Viewed from a clinical standpoint, the great-pressure impression is more effective than the alginate and no-pressure (slight-pressure) impressions in increasing denture pressure supportability.

Effect of captopril on isoproterenol-induced cardiac hypertrophy and polyamine contents

It is well known that isoproterenol (ISO) a nonselective beta adrenoceptor agonist induces cardiac hypertrophy. It can be assumed that, in addition to its direct cardiac effect, ISO has a cardiac trophic effect via stimulation of the renin angiotensin system. Synthesis of polyamines is facilitated in cardiac hypertrophy and polyamine levels are rapidly elevated prior to an increase in heart weight. In the present study, we investigated whether captopril (30 mg/kg body weight, daily) could attenuate cardiac hypertrophy and elevation of cardiac polyamine levels in rats, which effects were elicited by a chronic (1- or 2-weeks) and repeated administration of a small dose (0.5 mg/kg body weight) of ISO. Cardiac hypertrophy was assessed by an increase in the wet weight and RNA content of the heart. Polyamines were analyzed by HPLC. Captopril alone did not affect either heart weight/body weight ratio or cardiac contents of polyamines and nucleic acids at the end of the second week. In isoproterenol-treated rats, the above parameters, except for putrescine content on day 14, were significantly increased on both day 7 and day 14. Captopril slightly attenuated ISO-induced cardiac hypertrophy and significantly prevented the ISO-evoked increase in the contents of RNA, spermidine, and spermine at the end of the second week. These results suggest that the ISO-evoked increase in cardiac polyamines was mediated, at least in part, by the renin angiotensin system, which was stimulated by ISO.

Preserved thyroidal secretion of thyroxine in acromegalic patients with suppressed hypophyseal secretion of thyrotrophin

OBJECTIVE

We have assessed the mechanisms which maintain euthyroidism in acromegalic patients despite the suppression of thyrotrophin (TSH) secretion.

MATERIALS

Fourteen untreated patients with acromegaly were analysed. Ten patients were also studied after pituitary surgery.

METHODS

Thyroid hormones, growth hormone (GH), insulin-like growth factor-I (IGF-I) and thyroidal uptake of radioactive iodine, thyrotrophin releasing hormone (TRH) test and basal metabolic rate (BMR) were measured before and after pituitary surgery.

RESULTS

Nine patients had palpable goitres. The TSH response to TRH stimulation was suppressed in eight patients, who maintained normal serum levels of total T3, T4 and free T4. The patients with normal TSH response had lower levels of free and total T4 than controls. The response of TSH to TRH correlated inversely with the serum level of total and free T4, and also with the plasma level of IGF-I (r = -0.74, P less than 0.05, n = 9). After pituitary surgery, the serum levels of total and free T4 were elevated for at least up to 6 months, with a decrease in the T3/T4 ratio and the BMR.

CONCLUSION

GH may have a direct stimulatory action on the thyroid secretion of T4 possibly via increased IGF-I, despite suppressed TSH secretion. The post-operative elevation of serum T4 suggests the persistent secretion of T4 from the thyroid gland, in spite of instantaneous normalization of the accelerated conversion of T4 to T3, even after reduction of excess GH secretion.

Reversible primary hypothyroidism and elevated serum iodine level in patients with renal dysfunction

Recovery of thyroid function in patients with both thyroid and renal dysfunction was studied. Among 245 patients with primary hypothyroidism (serum TSH greater than 10 mU/l), 36 had mild to severe renal dysfunction (serum urea nitrogen greater than 7.1 mmol/l and creatinine greater than 106 mumol/l). Of these 36 patients, recovery of the thyroid function after iodine restriction was observed in 30 (83%), in whom an elevated serum non-hormonal iodine level (median 236, range 67-15,591 micrograms/l, N = 19) and a high thyroidal radioactive iodine uptake (51.5 +/- 29.3% at 24 h, N = 26) were observed. The perchlorate discharge test was positive in 7 of 13 patients examined, suggesting an iodide organification defect rather than an atrophic or destructive change in the thyroid. Antithyroid antibodies were negative in 22 patients (73%) and an almost normal thyroid gland or colloid goitre was confirmed histologically in 8 of them. After a 13.2 mg potassium iodide loading test, 24 h urinary excretion of iodine was about 60% in normal controls, but only 10% in a different group of six euthyroid patients with renal dysfunction. These findings suggest that impaired renal handling of iodine rather than autoimmune mechanism may have a significant role in the pathogenesis of reversible hypothyroidism found in patients with renal dysfunction, probably through a prolonged Wolff-Chaikoff effect.