Effectiveness of Indiana's Statewide Smoke-Free Indoor Air Law in Reducing Prevalence of Adult Cigarette Smoking

Indiana recently implemented a statewide smoke-free indoor air law that has prohibited smoking in both restaurants and non-hospitality workplaces. Evidence for the effectiveness of the recent statewide smoke-free indoor law may persuade 14 states that do not have any statewide smoke-free laws to enact such laws. We evaluated the effectiveness of Indiana's State Smoke-Free Air Law, implemented July 2012, in reducing adult smoking prevalence. We analyzed samples of U.S. adults using a nonequivalent control group design with multi-year, cross-sectional data from the 2011-2016 Behavioral Risk Factor Surveillance System ( N= 2,259,014). Four state groups with different levels of comprehensiveness in regard to statewide smoke-free indoor air laws in 2011-2016 served as the comparison groups, namely those with: (1) no law; (2) a partial law (prohibiting smoking in either one or two of these three settings, namely non-hospitality workplaces, restaurants, and bars); (3) a comprehensive law (prohibiting smoking in all non-hospitality workplaces, restaurants, and bars); and (4) those that changed from a partial to a comprehensive law. We used a difference-in-differences approach with multiple logistic regressions to assess the net effect of the policy with a secular trend removed. The decline rate of cigarette smoking in Indiana was steeper, from 21.2% in 2011-2012 to 17.8% in 2013-2016, than in states in our four comparison groups, which suggests a significant reduction in adult cigarette smoking prevalence above and beyond the downward secular trend observed. All the comparison groups showed higher odds of cigarette smoking than Indiana (adjusted odds ratios range from 1.08 to 1.16). Although a long-term effect of Indiana's State Smoke-Free Air Law has yet to be evaluated, current data indicate that such a policy appears to be effective in reducing smoking prevalence. The implementation of statewide smoke-free indoor air laws in all restaurants and non-hospitality workplaces may help reduce smoking rates in the 14 states that still do not have any statewide smoke-free indoor air laws.

Sex and racial/ethnic differences in the prevalence of overweight and obesity among U.S. college students, 2011-2015

To investigate sex and racial/ethnic differences in overweight and obesity in college students. Participants: A nationally representative sample of 319,342 U.S. college students (mean age = 20.4 years; 67.7% female) from Fall 2011 to Spring 2015. Methods: A secondary data analysis of multi-year cross-sectional data was performed. Multiple logistic regression was used to examine factors (e.g. cumulative grade average, year in school, and living place) associated with overweight and obesity determined from BMI calculated by self-reported height and weight. Results: The prevalence of overweight and obesity was significantly higher for both sexes in Spring 2015 than in Fall 2011. Significant differences were found in overweight and obesity by sex and race/ethnicity. Higher adjusted odds ratios for overweight and obesity were observed for men, blacks, and Hispanics (compared to whites). Asians had the lowest adjusted odds of overweight and obesity. Conclusions: Intervention strategies for the prevention and management of overweight and obesity in U.S. college students should consider sex and racial/ethnic inequalities.

Sex differences in weight perception and weight gain among Black college students in the USA

Objectives

The aims of this study were to examine the prevalence of overweight/obesity and to explore sex differences in body weight perceptions and correlates of weight gain among Black students at 2 historically Black colleges and universities (HBCUs) in the USA.

Methods

Participants completed a paper-based survey, and their height and weight were measured (67% completion rate).

Results

The overweight and obesity rates were 33.8% and 26.9%, respectively. More females than males accurately assessed their weight (p<0.05). Body weight underestimation was associated with male sex, excellent/very good perceived overall health, and not being informed by a doctor of having overweight or obesity (p<0.01). Higher odds of ≥5% weight gain were related to female sex, living on campus, and not being informed by a doctor of having overweight or obesity (p<0.05).

Conclusion

Given the high overweight and obesity rates among Black students, HBCUs in the USA should develop intervention strategies for the prevention and management of overweight and obesity. College health educators at HBCUs need to provide regular check-ups or health screenings that help male students perceive their weight accurately and prevent weight underestimation. It is important for HBCUs to monitor and address weight gain among Black students as early as possible.

Relationship between sleep and obesity among U.S. and South Korean college students

Background

Little is known about the relationship between sleep and obesity in young adults, particularly college students. This study examined the relationship between sleep (i.e., sleep duration and quality) and obesity in a large and diverse binational sample of college students.

Methods

Analyses were based on a 40-item paper survey from 2016/2017 to 2017/2018 academic years, with a 72% response rate. The samples were 1578 college students aged 18–25 years from five universities (two in the U.S. and three in South Korea). Weight and height were measured objectively; other measures (e.g., health behaviors) were self-reported. Multinomial logistic regression was used to assess the association between sleep duration and independent variables (race/nationality, gender, and BMI). Poisson regression was used to examine the relationship between sleep quality and independent variables.

Results

Overall, blacks had a higher adjusted odds ratio (AOR) of short sleep (< 7 h/night) than whites (AOR = 1.74, P < .01); overweight participants had a higher AOR of short sleep than normal weight participants (AOR = 1.52, P < .01); and obese participants had a higher AORs of both short and long sleep (> 9 h/night) (AOR = 1.67, P < .01; AOR = 1.79, P < .05, respectively). Among men, being black, overweight, and obesity were associated with short sleep (P < .05), whereas only obesity was related to short sleep among women (P < .05). In analyses stratified by race and nationality, overweight and obesity were related to short sleep among blacks only (P < .05). Overall, sleep quality (getting enough sleep to feel rested in the morning in the past 7 days) was worse in blacks and South Koreans than whites (P < .05), worse in women than men (P < .05), and worse in participants with obesity than normal weight participants (P < .05).

Conclusions

Obesity was associated with both short (< 7 h/night) and long sleep duration (> 9 h/night) and poor sleep quality among all participants. In comparison with whites, blacks were more like to have short sleep, and blacks and South Koreans had worse sleep quality. Further investigations using a larger sample of college students in multiple countries may be helpful to identify target populations who are at a greater risk of obesity and sleep problems.

Factors influencing U.S. physicians' decision to provide behavioral counseling

Prevention and treatment of non-communicable diseases is critical due to high costs of healthcare and increasing prevalence. Historical trends suggest physicians underperform in behavioral counseling (including exercise, diet/nutrition, or weight management). This study investigated physicians' decision-making by examining non-clinical sociological factors that influence ordering and provision of behavioral counseling. This was a retrospective multi-year cross-sectional study. Using the Eisenberg model of physician-decision making, we analyzed data from the 2005-2015 National Ambulatory Medical Care Surveys (unweighted N = 177,599). Four weighted logistic regressions were performed to examine sociological factors associated with physician prescribing or ordering of behavioral counseling. Behavioral counseling was provided at suboptimal rates. Patient age, race/ethnicity, body weight status, and reasons for a medical visit were associated with physicians' decision to provide or order behavioral counseling. There was in general a decreasing trend of odds of provision of behavior counseling from 2005 to 2015. Patients who had been seen before were more likely to receive diet/nutrition and exercise counseling. This study concluded that ordering and provision of behavioral counseling was less than optimal. Policy makers and educators can consider factors that influence physicians' decisions for behavioral counseling to improve training and site policies. Future research examining effective behavioral counseling training and strategies to promote its provision, in particular to patients of different races/ethnicities and with different medical conditions, may increase effectiveness. Integrated care with behavioral health professionals could improve rates and/or delivery of counseling. Physicians can consider providing behavioral counseling when patients present with new problems and to newly seen patients.

Associations of Father's Lifetime Cannabis Use Disorder with Child's Initiation of Cannabis Use, Alcohol Use, and Sexual Intercourse by Child Gender

BACKGROUND

Early initiation of alcohol use, cannabis use, and sexual intercourse among adolescents is an important public health concern in the United States. Parents' history of substance use disorder is an important contributing factor for children's problem behaviors.

OBJECTIVES

The associations of fathers' lifetime cannabis use disorder with children's initiation of cannabis use, alcohol use, and sexual intercourse were examined. In addition, child's gender was considered as a moderator of each association.

METHODS

Data from two companion longitudinal studies was utilized, the Rochester Youth Developmental Study and its intergenerational extension, the Rochester Intergenerational Study. Multiple linear regression analyses were conducted to examine the associations of the father's lifetime cannabis use disorder with the child's initiation of cannabis use, alcohol use, and sexual intercourse. To test gender differences in the associations, the study sample was stratified by child's gender.

RESULTS

The average age of first cannabis use (b = -3.71, p < .05), alcohol use (b = -3.65, p < .05), and sexual intercourse (b = -2.94, p < .05) among daughters of fathers with a lifetime cannabis use disorder was lower than that of their counterparts after adjusting for all other control variables, whereas no significant differences were detected in a father-son relationship.

CONCLUSIONS

Homotypic continuity of cannabis use, as well as heterotypic continuity from the father's cannabis use to the child's alcohol use and sexual intercourse existed in a father-daughter relationship. These findings suggest that family-based interventions for female adolescents whose father has suffered from a cannabis use disorder be developed to prevent better adolescents' early substance use and sexual intercourse.

Adolescent Weight and Electronic Vapor Product Use: Comparing BMI-Based With Perceived Weight Status

INTRODUCTION

This study examined the associations of BMI-based and perceived body weight status with electronic vapor product use, cigarette smoking, and dual use among U.S. adolescents.

METHODS

A cross-sectional analysis was conducted in 2017 on data from 15,129 adolescents in the National Youth Risk Behavior Survey, 2015. Multiple logistic regression analyses were used to examine the associations of BMI-based and perceived weight status with electronic vapor product use, cigarette smoking, and dual use, after adjusting for all other covariates. The regression models were stratified by gender.

RESULTS

Overall, 25.5% of males used electronic vapor products, 11.6% smoked cigarettes, and 8.1% used both; percentages among females were 22.6%, 9.8%, and 6.8%, respectively. Females who perceived themselves as overweight were more likely than those who perceived themselves as normal weight to be current electronic vapor product users (AOR=1.09, 95% CI=1.01, 1.19) and dual users (AOR=1.23, 95% CI=1.01, 1.49). When compared with normal BMI-based category, males with obese BMI status were more likely to be current cigarette smokers (AOR=1.61, 95% CI=1.06, 2.44), however, only females with overweight BMI status were more likely to be current smokers (AOR=1.89, 95% CI=1.25, 2.86).

CONCLUSIONS

Findings suggest that the influence of adolescents' body weight perceptions and BMI-based status should be accounted for when developing nicotine-containing product use prevention programs for adolescents. Specific strategies for influencing female adolescents who perceive themselves as overweight should be included to prevent emerging electronic vapor product and dual use.

BMI and Central Obesity With Falls Among Community-Dwelling Older Adults

INTRODUCTION

This study examined the associations of BMI category and central obesity status, with falls among community-dwelling older adults in the U.S.

METHODS

Data were drawn from the 2012 and 2014 U.S. Health and Retirement Study, a nationally representative longitudinal panel study funded by the National Institute of Aging. The study participants were U.S. community-dwelling older adults aged ≥65 years (N=3,383). Multiple logistic regression and Poisson regression analyses examined the associations of BMI category and central obesity (waist circumference >102 cm in men and >88 cm in women) with experiencing a fall and fall injury, after adjusting for all other covariates. A prospective analysis was conducted in which independent variables from 2012 were examined in relation to dependent variables measured in the same participants in 2014.

RESULTS

Overall, 35.2% of older adults experienced at least one fall in the past 2 years. Compared with those who were not, centrally obese older adults were more likely to experience a fall (AOR=1.37, 95% CI=1.01, 1.85) and fall more frequently (incidence rate ratio=1.15, 95% CI=1.03, 1.29). Fallers in the obese BMI category were less likely than normal-weight fallers to experience a fall injury (AOR=0.56, 95% CI=0.35, 0.91).

CONCLUSIONS

These findings suggest that (1) central obesity be measured when assessing older adults' fall risk and (2) specific community prevention strategies for centrally obese older adults be developed to better prevent falls and fall-related injuries.

Association of TNF-alpha promoter polymorphisms with aspirin-induced urticaria

OBJECTIVE

Although the pathogenesis of aspirin-induced urticaria (AIU) is not fully understood, mast cell activation has been noted in patients with AIU. Tumour necrosis factor (TNF)-alpha, a potent pro-inflammatory cytokine, is released by human skin mast cells and other inflammatory cells in patients with urticaria. To investigate the role of TNF-alpha promoter polymorphisms in the development of AIU, we performed an association study of TNF-alpha promoter polymorphisms with AIU phenotype.

METHODS

Two hundred thirty-nine patients with AIU consisting of 120 patients with aspirin intolerant chronic urticaria (AICU) and 119 with aspirin-intolerant acute urticaria (AIAU), and 524 normal controls were enrolled. AIU was confirmed by oral aspirin challenge test. Five SNPs in the TNF-alpha gene (-1031T>C, -863C>A, -857C>T, -308G>A, -238G>A) were genotyped by a single-base extension method. Haplotype analyses were done.

RESULTS

The genotype frequencies of TNF-1031T>C and TNF-863C>A were significantly higher in the AIU patients than in the normal controls in both co-dominant (P = 0.014, P = 0.007) and dominant (P = 0.007, P = 0.004) models. The frequency of TNF-ht2[CACGG] containing a genotype in the AIU group was significantly higher in the normal controls with both co-dominant (P = 0.004, Pc = 0.02) and dominant models (P = 0.002, Pc = 0.01).

CONCLUSIONS

These findings suggest that the two promoter polymorphisms of TNF-alpha at -1031T>C and -863C>A may contribute to the development of AIU.

Relationship between various surrogate indices of insulin resistance and mitochondrial DNA content in the peripheral blood of 18 healthy volunteers

Mutations or deletions of mitochondrial DNA (mtDNA) are associated with diabetes mellitus. In this study, we investigated the relationships between the mtDNA content in peripheral blood and surrogate indices of insulin resistance in 18 healthy young women (mean age 20.8 +/- 1.5 years). The mtDNA content was significantly correlated with the area under the curve of insulin during an oral glucose tolerance test (r = -0.622), the homeostasis model assessment for insulin resistance (r = -0.616), the ratio of fasting glucose to insulin concentration (r = 0.586) and the fasting insulin level (r = -0.552). Further study is warranted to elucidate the mechanism by which the mtDNA content is associated with insulin resistance.

p66Shc expression in proliferating thyroid cells is regulated by thyrotropin receptor signaling

It is almost unanimously accepted that thyrocyte proliferation is synergistically activated by TSH and insulin/IGF-I. Moreover, it was recently suggested that p66Shc, which is an adaptor molecule of the IGF-I receptor, might play a critical role in this synergistic effect. In this study, we undertook to confirm the role and the mechanism underlying the regulation of p66Shc expression via TSH receptor in thyrocytes. We have found that p66Shc expression is elevated in proliferating human thyroid tissues, including adenomatous goiter, adenoma, Graves' disease, and thyroid cancer, but not in normal thyroid. Among growth factors, TSH increased p66Shc expression both in vivo and in vitro; however, IGF-I, epidermal growth factor, or insulin did not. TSH and Graves' Ig increased the p66Shc expression via the TSH receptor-G(s)-cAMP pathway. However, interestingly, IGF-I or epidermal growth factor increased the tyrosine phosphorylations of p66Shc, and this was enhanced by TSH pretreatment. A similar synergism was observed during the DNA synthesis. When we measured the p66Shc levels induced by individual Igs from 130 patients with Graves' disease, TSH receptor stimulating activity and goiter size showed a weak correlation. We conclude that the expression of p66Shc is regulated by signaling through the TSH receptor in proliferating thyroid cells and that p66Shc appears to be an important mediator of the synergistic effect between TSH and IGF-I with respect to thyrocyte proliferation. Moreover, we suggest that TSH potentiates the regulatory effect of IGF-I on thyrocyte growth, at least in part, by increasing the expression of p66Shc.

Clinical significance of elevated level of serum antithyroglobulin antibody in patients with differentiated thyroid cancer after thyroid ablation

OBJECTIVE

This study was designed to investigate whether an elevated serum antithyroglobulin antibody (TgAb) reflects cancer recurrence in thyroglobulin (Tg)-undetectable patients with differentiated thyroid carcinoma (DTC) after thyroid ablation.

DESIGN

We measured serum TgAb level and evaluated the disease status in 226 DTC patients who had undergone remnant ablation and showed an undetectable Tg result as assessed by immunoradiometric assay.

MEASUREMENTS

Radioligand assay of TgAb was performed. Recurrence was assessed by 131I scan, 18F-fluorodeoxyglucose positron emission tomography, sonography, computed tomography, or by surgical operation.

RESULTS

Fifty-one patients (22.6%) of the Tg-undetectable patients showed positive TgAb, and 25 (49.0%) of these were confirmed with recurrence. The recurrence rate of TgAb-positive patients was higher than that of TgAb-negative patients (3.4%; P < 0.0001). During follow-up, 73.1% of the disease-free patients showed spontaneously decreased TgAb levels. A total of 71.4% of patients with recurrent cancer, who showed responses to surgical operation or radio-iodine treatment, also showed a decreased TgAb level.

CONCLUSIONS

Persistently elevated TgAb levels appear to serve as a useful marker for recurrent or persistent DTC in patients with undetectable serum Tg results. Thus, the routine measurement of TgAb in such patient populations may be indicated.

Diagnostic value of serum IGF-I and IGFBP-3 in growth hormone disorders in adults

OBJECTIVE

To investigate the diagnostic value of serum insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) measurements in adult patients with acromegaly and GH deficiency (GHD).

METHODS

Serum IGF-I and IGFBP-3 levels were measured in 39 active acromegalic patients, 34 adult patients with GHD and 150 healthy adults. Disease activity in patients with acromegaly was confirmed by nadir GH levels during an oral glucose tolerance test (OGTT). Among patients with acromegaly, 15 had not been treated previously and 24 had been treated but not cured. GHD in adults was diagnosed by an insulin tolerance test (ITT). Among patients with GHD, 15 were aged 20-40 years (9 men and 6 women) and 19 were aged over 40 years (9 men and 10 women). One hundred and fifty healthy subjects were recruited as a control group. To compare the individual serum IGF-I and IGFBP-3 levels of patients with the results of the gold standard, we calculated age- and sex-corrected standard deviation scores (SDS) for individual IGF-I and IGFBP-3 levels. The sensitivities of serum IGF-I and IGFBP-3 measurements for the disease diagnosis were analyzed using the mean +/- 2 SD of the values of healthy control subjects as a diagnostic cutoff, defining 95% specificity.

RESULTS

The mean IGF-I and IGFBP-3 SDS levels were significantly higher in active acromegalic patients, both untreated and treated but not cured, than in the control subjects (p < 0.05). The sensitivities of serum IGF-I and IGFBP-3 measurements for the diagnosis of acromegaly were 97.4 and 81.8%, respectively. In untreated patients with acromegaly, the sensitivities of serum IGF-I and IGFBP-3 measurements for the diagnosis of disease were 100 and 100%, while these were 95.8 and 72.7% in treated patients with acromegaly. In adult patients with GHD, the mean IGF-I and IGFBP-3 SDS were significantly lower than those of the control subjects (IGF-I, -2.2 +/- 0.8 vs. 0.0 +/- 1.0 SDS, p < 0.0001); IGFBP-3, -1.7 +/- 1.2 vs. 0.0 +/- 1.0 SDS, p < 0.0001), but there was a considerable overlap between GHD in adults and the controls. In all patients with GHD, the sensitivities of serum IGF-I and IGFBP-3 measurements were 64.7 and 52.9%, respectively. In the group of women aged 20-40 years, the sensitivity of IGF-I measurement for the diagnosis of GHD was 100%, although the number of patients was only 6.

CONCLUSION

Both serum IGF-I and IGFBP-3 measurements are comparable to an oral glucose tolerance test in patients with untreated acromegaly, but in acromegalic patients that have undergone surgery and/or radiotherapy, serum IGF-I is more valuable for determining disease activity than serum IGFBP-3. Serum IGF-I and IGFBP-3 measurements are not valuable for the diagnosis of GHD in adults, but in women aged 20-40 years serum IGF-I measurement appears to be useful in the diagnosis of GHD.

Clinical significance of classification of Graves' disease according to the characteristics of TSH receptor antibodies

BACKGROUND

It has been widely accepted that the epitope(s) and/or functional characteristics of thyrotropin receptor antibodies (TSHRAb) from Graves' patients are heterogenous among patients. However, the clinical significance of such heterogeneity has not been systematically evaluated yet. We were to elucidate and find the clinical significance of heterogeneity for TSH receptor antibodies in Graves' disease.

METHODS

We measured stimulating TSHRAb (TSAb) activities using CHO-hTSHR cells, FRTL-5 cells and chimeric receptor expressing cells (Mc1 + 2 and Mc2), specific blocking TSHRAb (TSBAb) activities using Mc2 cells and TBII activities using porcine thyroid membrane in 136 patients with untreated hyperthyroid Graves' disease.

RESULTS

Based on various TSHRAb activities from each patient, the patients could be categorized into 7 subgroups by cluster analysis; 1) Group 1 (n = 41) was characterized by moderate TSAb activities both in CHO-hTSHR cells and in FRTL-5 cells, typical TSAb epitope, rare blocking antibodies and high TBII activities. 2) Group 2 (n = 16) was characterized by the presence of blocking TSHRAb in most patients, albeit the other characteristics were the same as those in Group 1. 3) Group 3 (n = 19) patients had low TSAb activities both in CHO-hTSHR cells and in FRTL-5 cells, seldom had blocking TSHRAb, but they had high TBII activities. 4) Group 4 (n = 30) could be categorized as 'mild disease' group, as they had low activities in all kinds of TSHRAb assay and had low antimicrosomal antibody activities. 5) Group 5 (n = 14) was characterized by moderate TSAb activities with atypical epitope(s), rare blocking TSHRAb and moderate TBII activities. 6) Group 6 (n = 10) patients had very high TSAb activities with typical epitopes, seldom blocking TSHRAb and low TBII activities. 7) Group 7 (n = 6) was characterized by very high TSAb activities with atypical epitopes and high TBII activities. Pretreatment serum thyroid hormone level was low only in group 4 patients compared to the other 6 groups (p < 0.05). The size of goiter was significantly larger in those in group 1 and group 3 (p < 0.05) compared to the other 5 groups. The prevalence of clinically significant ophthalmopathy was higher in group 2 patients than the other 6 groups (50% vs. 27.5%, p = 0.06). Among 6 kinds of TSHRAb activities, only the blocking TSHRAb activity was significantly associated with the presence of ophthalmopathy in multivariate analysis.

CONCLUSION

These results suggest that the differences in epitopes for TSAb or the presence of blocking TSHRAb is not a major factor in determining the degree of thyrotoxicosis in Graves' disease. Although the pathogenic mechanism is not clear yet, we suggest that patients with ophthalmopathy have different TSHRAb repertoire from those without ophthalmopathy in Graves' disease.

Homogeneous fluorescent derivatization of large proteins

A method of homogeneously derivatizing large proteins for highly sensitive analysis is described. Homogeneity of the derivative was realized by tagging all the free amino groups of proteins. With this method, alpha-chymotrypsinogen A, ovalbumin and bovine serum albumin were derivatized with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC). Prior to the derivatization, all the proteins were reduced and alkylated. After reacting the resulting unfolded proteins with excessive amounts of AQC, the samples were analyzed with matrix assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) to determine the derivatization degree. The results indicated that all three proteins had been, or had almost been, fully derivatized. HPLC and CE were used for characterizing these protein derivatives. Under the optimized fluorescence detection conditions, the detectability of the tagged proteins was 2400-6200 times better than that detected at UV 280 nm, 170-300 times better than detected at UV 214 nm, and 150-420 times better than measured with their native fluorescence.

Relationship between expression of the sodium/iodide symporter and 131I uptake in recurrent lesions of differentiated thyroid carcinoma

The sodium/iodide symporter (NIS) is known to be responsible for the active accumulation of iodide within the thyroid gland. We evaluated the relationship between the expression of NIS in primary or lymph node lesions and iodine-131 uptake in recurrent lesions of differentiated thyroid cancer. In 67 patients with differentiated thyroid cancer (5 follicular and 62 papillary carcinomas), the expression of NIS was analysed by immunohistochemical staining using polyclonal antibodies against human NIS. We used paraffin block tissues of primary tumours or metastatic lesions, and also assessed 131I uptake in recurrent lesions of thyroid cancer on post-operative 131I whole-body scan. Immunohistochemical staining was positive in 22 patients (32.8%), including 2 of 5 follicular and 20 of 62 papillary carcinomas. Recurrence was confirmed in 40 patients pathologically or clinically by serum thyroglobulin, 131I scan, fluorine-18 fluorodeoxyglucose positron emission tomography and/or computed tomography. Among these 40 patients, 28 showed positive uptake on 131I scan. Fourteen tumour specimens out of 28 (50%) were positive by NIS immunohistochemical staining. The remaining 12 patients with recurrent cancer showed negative 131I scans, and all specimens were negative by NIS immunohistochemical staining. Thus, NIS immunohistochemical staining predicted 131I uptake in recurrent cancer with a 100% positive predictive value and a 46.2% negative predictive value. There was no difference in the positivity of NIS according to the site of recurrence on 131I scan. Outcome of 131I therapy could be assessed in 22 of the 28 patients who showed 131I uptake in recurrent lesions. Patients with positive NIS immunostaining responded to 131I therapy better than did patients with negative immunostaining (P<0.05). In conclusion, NIS immunohistochemical staining showed a high positive predictive value in predicting iodine uptake. Positive immunohistochemical staining of human NIS in primary or lymph node lesions may predict 131I accumulation and effectiveness of 131I therapy in recurrent lesions.

Dissociation between plasma adrenocorticotropin and serum cortisol level during the early postoperative period after gastrectomy

We demonstrated the dissociation between plasma adrenocorticotropin (ACTH) and serum cortisol levels during the early recovery period after radical gastrectomy in 9 of 31 patients with gastric adenocarcinoma. Patients with the dissociation between plasma ACTH and serum cortisol levels (DAC) showed a sustained elevation of serum cortisol level on the first or second postoperative day, while the plasma ACTH level returned to its preoperative state. These patients also had more advanced cancers (p < 0.05) and suffered from more postoperative complications (p < 0.05) than those without DAC. In these patients with DAC, serum cortisol and interleukin (IL)-6 levels remained higher on the second postoperative day than in those of the patients without DAC (21.80 +/- 1.57 vs. 13.68 +/- 0.72 microg/dl, p < 0.001, and 74.31 +/- 15.65 vs. 18.75 +/- 3.14 pg/ml, p < 0.001, respectively). On the second postoperative day, serum IL-6 levels showed a significant correlation with serum cortisol levels in all patients (r = 0.511, p < 0.01). These results suggest that the DAC during the early postoperative period after radical gastrectomy is associated with advanced stage of cancer and postoperative complication, and that the increased serum IL-6 level is at least in part responsible for maintaining the elevated serum cortisol.

F-18-fluorodeoxyglucose positron emission tomography as a presurgical evaluation modality for I-131 scan-negative thyroid carcinoma patients with local recurrence in cervical lymph nodes

BACKGROUND

F-18-labeled fluorodeoxyglucose-positron emission tomography (FDG-PET) has a supplementary role in localizing recurrent sites of differentiated thyroid carcinoma. We evaluated whether FDG-PET is feasible as a presurgical evaluation modality for I-131 scan-negative thyroid carcinoma patients.

METHODS

Preoperative FDG-PET results were compared with the pathologic findings of lymph nodes specimens of 22 papillary thyroid patients. All patients had thyroidectomy and I-131 ablation therapy beforehand and showed negative I-131 scans on follow-up studies.

RESULTS

In 85 cervical lymph node groups dissected, 56 lymph node groups revealed metastasis. The sensitivity and specificity of FDG PET for metastasis were 80% (45 of 56) and 83% (24 of 29), respectively. Among the pathologically positive 33 lymph nodes with normal size(< or =1 cm), FDG-PET detected 23 nodes. Serum thyroglobulin levels were elevated in 12 patients (sensitivity, 55%).

CONCLUSION

FDG-PET accurately detected the recurred cervical lymph nodes of differentiated thyroid carcinoma patients who showed negative I-131 scan. FDG-PET is suitable for the presurgical evaluation of these patients.

Prevalence of Gs alpha mutations in Korean patients with pituitary adenomas

The reported frequencies of Gs alpha mutations (gsp mutations) in growth hormone (GH)-secreting pituitary adenomas are variable (ranging from 4.4 to 43%), and the presence of these mutations in the other pituitary adenomas is still a matter of controversy. Previous clinical and biochemical analyses of patients with GH-secreting pituitary adenomas and gsp mutations produced conflicting results and did not demonstrate obvious characteristics. Therefore, we investigated the prevalence of gsp mutations in Korean patients with pituitary adenomas and elucidated the characteristics of these patients. Forty-four GH-secreting adenomas, 7 prolactin (PRL)-secreting adenomas and 32 clinically non-functioning adenomas were examined for the presence of point mutations in codon 201 and 227 of the Gs alpha gene using a nested PCR and direct sequencing of DNA extracted from fresh tissue or paraffin-embedded pituitary adenoma samples. Seven of the 44 GH-secreting pituitary adenomas had point mutations at codon 201 or 227; of these, five mutations were in codon 201 and two were in codon 227. In patients with gsp mutations, mean tumor size was significantly smaller than in patients without gsp mutations (15.9+/-8.7 mm vs. 24.9+/-14.9 mm, P<0.05). Age, sex, basal GH levels, GH response to oral glucose loading, GH response to octreotide and surgical outcome were not different in the two groups. One of the 32 clinically non-functioning pituitary adenomas had a point mutation at codon 201; none of the seven prolactinomas had these mutations. These results show that gsp mutations are not rare in Korean acromegalic patients and mean tumor size is significantly smaller in acromegalic patients with gsp mutations. Our results also confirm the low frequency of gsp mutations in clinically non-functioning pituitary adenomas and the absence of gsp mutations in prolactinoma.

Increased prevalence of autoimmune thyroid disease in patients with type 1 diabetes

BACKGROUND

Type 1 diabetes mellitus is frequently associated with other autoimmune diseases. The occurrence of common features of autoimmune diseases and the coassociation of multiple autoimmune diseases in the same individual or family supports the notion that there may be common genetic factors.

METHODS

To investigate potential clustering of autoimmune thyroid disease (ATD) among type 1 diabetes patients and the contribution of common susceptibility genes to this, HLA DR/DQ alleles as well as antithyroid autoantibodies were measured in 115 Korean patients with type 1 diabetes and their 96 first-degree family members.

RESULTS

Twenty-five percent of the patients had ATD, whereas 3 of 36 (8%) age-matched normal controls had ATD (RR = 3.7, p < 0.05). Twenty-six of ninty-six (27%) type 1 diabetes family members had ATD. No differences in the distribution of HLA alleles/haplotypes and genotypes between the patients with and without ATD were found.

CONCLUSION

From this finding, we could assess that individuals with type 1 diabetes and their relatives frequently develop ATD, perhaps due to common susceptibility genes that are shared among first degree relatives.

Effect of exercise on the mitochondrial DNA content of peripheral blood in healthy women

Exercise decreases insulin resistance and increases maximal exercise capacity as estimated from maximal oxygen uptake (VO2max). Recent reports have demonstrated that the mitochondrial DNA (mtDNA) content of blood is correlated with VO2max in healthy subjects (mean age 31 years) and is inversely correlated with insulin resistance parameters. The aim of this study was to determine the effect of regular exercise on the mtDNA content in the peripheral blood of 16 healthy young women of mean age 24.8 (SD 6.2) years and 14 healthy older women of mean age 66.7 (SD 5.8) years. The exercise programme lasted for 10 weeks and consisted of three sessions a week, each of 1 h and aiming to attain 60%-80% of VO2max. The mtDNA content of peripheral blood was measured by competitive polymerase chain reaction. The VO2max had significantly increased following the exercise programme [from 33.1 (SD 3.4) to 35.2 (SD 3.4) ml x kg(-1) min(-1) in the young and from 24.3 (SD 5.3) to 30.3 (SD 7.3) ml x kg(-1) x min(-1) in the older women, both P < 0.05]. Exercise decreased systolic blood pressure, and concentrations of triglyceride, low density lipoprotein-cholesterol (LDL-C), glucose and insulin in the blood of the young and of total cholesterol, LDL-C and glucose in that of the older women. High density lipoprotein-cholesterol (HDL-C) in the young women was increased by exercise. The mtDNA content significantly increased following the exercise programme in both groups [from 27.1 (SD 17.9) to 52.7 (SD 44.6) amol x 5 ng(-1) genomic DNA in the young and from 15.3 (SD 10.2) to 32.1 (SD 30.0) amol x 5 ng(-1) genomic DNA in the older women, both P < 0.05]. There was a significant positive correlation between the change in mtDNA content and the change in VO2max (r = 0.74 in the young and r = 0.71 in the older women, both P < 0.01). In conclusion, 10 weeks of moderate intensity, regular exercise increased the mtDNA content in peripheral blood and decreased insulin resistance parameters. This data suggests that increase in the mtDNA content may be associated with increased insulin sensitivity.

The prevalence and clinical significance of blocking thyrotropin receptor antibodies in untreated hyperthyroid Graves' disease

The goal of this study was to evaluate the clinical significance of the blocking thyrotropin receptor antibodies (TSHRAb) in Graves' disease. The amount of blocking and stimulating TSHRAb were measured in 200 patients with untreated hyperthyroid Graves' disease using several cell lines carrying different TSHR chimera. Stimulating TSHRAb were measured in Chinese hamster ovary (CHO) cells with wild-type human TSHR (CHO-hTSHR) or a TSHR chimera with residues 90-165 (Mc2) or 8-165 (Mc1+2) substituted by equivalent residues of rat luteinizing hormone/chorionic gonadotrophin (LH/CG) receptor or in FRTL-5 cells. Blocking TSHRAb were measured in Mc2 cells. The activities of different TSHRAb were assessed and clinical features were compared to patients who were positive or negative for blocking TSHRAb antibodies. Blocking TSHRAbs were detected in 18.5% of patients (37/200) with hyperthyroid Graves' disease. Patients with blocking antibodies had significantly lower mean stimulating TSHRAb activities than those without blocking antibodies in wild-type CHO-hTSHR cells (301 +/- 179 vs. 446% +/- 537%, p = 0.005). Mean stimulating TSHRAb activities measured by FRTL-5, Mc1+2, or Mc2 cells and mean thyrotropin receptor inhibitor immunoglobulin (TBII) activities were not different between the two groups. The patients with blocking antibodies were not different from those without blocking antibodies in age, gender ratio, initial serum free thyroxine (T4) levels, or goiter size. However, the prevalence of exophthalmos was higher (35.1% vs. 17.5%, p = 0.024) in the patients with blocking antibodies than those without. In summary, the presence of blocking TSHRAb is not rare in patients with hyperthyroid Graves' disease when measured with chimeric receptor expressing cells. Blocking TSHRAb in Graves' sera do not strongly antagonize the action of stimulating TSHRAb in vivo, but could be a major factor responsible for underestimation of stimulating TSHRAb activities measured by CHO-hTSHR. The association of blocking TSHRAb with ophthalmopathy suggests that the TSHRAb repertoire of Graves' patients is different in those who do and who do not have ophthalmopathy.

Polymorphism in the promoter and exon 1 of the cytotoxic T lymphocyte antigen-4 gene associated with autoimmune thyroid disease in Koreans

The objective of this study was to examine the polymorphism in the cytotoxic T lymphocyte antigen-4 (CTLA-4) gene and its relationship with autoimmune thyroid disease in Koreans. Polymorphism in the promoter and exon 1 of CTLA-4, clinical symptoms of disease and thyrotropin receptor antibody (TSHRAb) characteristics were analyzed. Polymorphism was detected using restriction fragment length polymorphism and polymerase chain reaction amplification of genomic DNA. All subjects were Korean (97 Graves' disease, 110 Hashimoto's thyroiditis, and 199 normal controls). Graves' patients had significantly more G allele in exon 1 and C allele in the promoter than controls. When the exon 1 genotype was GG, the frequency of CC genotype in the promoter was higher. Allele frequencies in CTLA-4 did not differ from controls in patients with Hashimoto's thyroiditis. In Graves' patients, there were significant differences between genotypic groups in serum triiodothyronine (T3) levels and the presence of ophthalmopathy. However, TSHRAbs and other clinical characteristics were not significantly different. In conclusion, the CTLA-4 G allele in exon 1 and C allele in the promoter may confer genetic susceptibility to Graves' disease in Koreans. These two polymorphisms are additional and dependent genetic risk markers that help to characterize risk alleles within CTLA-4 gene.

Involvement of JAK/STAT (Janus kinase/signal transducer and activator of transcription) in the thyrotropin signaling pathway

TSH is an important physiological regulator of growth and function in thyroid gland. The mechanism of action of TSH depends on interaction with its receptor coupled to heterotrimeric G proteins. We show here that TSH induces the phosphorylation of tyrosine in the intracellular kinases Janus kinase 1 (JAK1) and -2 (JAK2) in rat thyroid cells and in Chinese hamster ovary (CHO) cells transfected with human TSH receptor (TSHR). The JAK family substrates STAT3 (signal transducers and activators of transcription) are rapidly tyrosine phosphorylated in response to TSH. We also find that JAK1, JAK2, and STAT3 coprecipitate with the TSHR, indicating that the TSHR may be able to signal through the intracellular phosphorylation pathway used by the JAK-STAT cascade. TSH increases STAT3-mediated promoter activity and also induces endogenous SOCS-1 (suppressor of cytokine signaling-1) gene expression, a known target gene of STAT3. The expression of a dominant negative form of STAT3 completely inhibited TSH-mediated SOCS-1 expression. These findings suggest that the TSHR is able to signal through JAK/STAT3 pathways.

Thyrotropin induces SOCS-1 (suppressor of cytokine signaling-1) and SOCS-3 in FRTL-5 thyroid cells

TSH has multiple physiological roles: it is required for growth, differentiation, and function of the thyroid gland, and it regulates transcription of interferon-gamma (IFN-gamma)-responsive genes in thyrocytes, including genes for the major histocompatibility complex and intercellular adhesion molecule-1. This report demonstrates that TSH induces the expression of suppressor of cytokine signaling (SOCS)-1 and -3 proteins and alters the phosphorylation state of signal transducer and activator of transcription (STAT) proteins STAT1 and STAT3. The expression of SOCS-1 and SOCS-3 and the phosphorylation state of STAT1 and STAT3 were examined after treatment with TSH or IFN-gamma in either TSH-sensitive FRTL-5 thyroid cells or TSH-insensitive FRT and buffalo rat liver (BRL) cells, which lack functional TSH receptors. SOCS-1 and SOCS-3 are constitutively expressed in FRTL-5 cells, but not in FRT and BRL cells. IFN-gamma up-regulated SOCS-1 and SOCS-3 RNA and protein in FRTL-5 cells, as reported previously for nonthyroid cells. Interestingly, TSH also significantly induced SOCS-1 and SOCS-3 in FRTL-5 cells, but not in FRT and BRL cells. When SOCS-1 or SOCS-3 was overexpressed in FRTL-5 cells, STAT1 phosphorylation at Y701 and STAT1/DNA complex formation in response to IFN-gamma were reduced. Furthermore, overexpression of either SOCS-1 or SOCS-3 significantly inhibited the IFN-gamma-mediated transactivation of the rat ICAM-1 (intercellular adhesion molecule-1) promoter. TSH and IFN-gamma had different effects on STAT1 and STAT3 phosphorylation. The phosphorylation of Y701 in STAT1, which is responsible for homodimer formation, nuclear translocation, and DNA binding, was specifically stimulated by IFN-gamma, but not by TSH or forskolin. However, the phosphorylation of S727 in STAT1 was induced by IFN-gamma, TSH, and forskolin. TSH induced phosphorylation of both Y705 and S727 in STAT3, while IFN-gamma phosphorylated only the Y705. In addition, we found that SOCS-3 was associated with JAK1 and JAK2 and that these associations were stimulated by TSH. These findings demonstrate that TSH induces SOCS in thyroid cells and provides the evidence of signal cross-talk between TSH and cytokines in thyroid cells.

Metabolic effect of decreasing nonesterified fatty acid levels with acipimox in hyperthyroid patients

Glucose intolerance is often found in patients with hyperthyroidism, but the pathogenetic mechanisms are not fully understood. Since lipolysis is increased in hyperthyroidism, elevated plasma nonesterified fatty acids (NEFAs) may contribute to abnormal glucose metabolism in hyperthyroidism. The aim of this study was to investigate whether decreasing the plasma NEFA level with acipimox can affect glucose metabolism in hyperthyroidism. We performed an intravenous glucose tolerance test (IVGTT) with acipimox 250 mg or placebo in six untreated hyperthyroid men and six age- and body mass index (BMI)-matched controls. Fasting plasma NEFA levels were significantly higher in the hyperthyroid patients versus the controls (997.0 +/- 303.4 v290.5 +/- 169.1 micromol/L, P < .001). Plasma NEFAs decreased rapidly with acipimox treatment in both controls and hyperthyroid patients. In the controls, the glucose disappearance constant (K(G)) was not different for acipimox treatment versus placebo (2.18 +/- 0.62 v 2.42 +/- 1.00% x min(-1)). In hyperthyroid patients, acipimox treatment increased the K(G) significantly compared with placebo treatment (2.44 +/- 0.84 v 1.58 +/- 0.37% x min(-1), P < .05). Changes in K(G) values with acipimox treatment were inversely correlated with changes in plasma NEFA levels (r = -.65, P < .05). Acipimox treatment increased the acute insulin response (AIR) in hyperthyroid patients (943 +/- 381 v 698 +/- 279 microU/mL x min, P < .05), whereas it did not change the AIR in controls. Changes in the AIR with acipimox treatment correlated significantly with changes in the K(G) (r = .70, P < .05). There was a weak correlation between changes in the AIR with acipimox treatment and changes in plasma NEFA levels (r = -.55, P = .06). In summary, decreasing the plasma NEFA level with acipimox in hyperthyroid patients increases both the K(G) and AIR during an IVGTT. These findings suggest that the abnormal glucose metabolism in hyperthyroidism could be attributed, at least in part, to the increase of plasma NEFA.

Value of FDG PET in papillary thyroid carcinoma with negative 131I whole-body scan

The management of metastatic thyroid carcinoma patients with a negative 131I scan presents considerable problems. Fifty-four athyrotic papillary thyroid carcinoma patients whose 1311 whole-body scans were negative underwent 18F-fluorodeoxyglucose (FDG) PET; the purpose was to determine whether this procedure could localize metastatic sites. We also assessed its usefulness in the management of these patients.

METHODS

Whole-body emission scan was performed 60 min after the injection of 370-555 MBq 18F-FDG, and additional regional attenuation-corrected scans were obtained. Metastasis was pathologically confirmed in 12 patients and was confirmed in other patients by overall clinical evaluation of the findings of other imaging studies and of the subsequent clinical course.

RESULTS

In 33 patients, tumor had metastasized, whereas 21 patients were in remission. FDG PET revealed metastases in 31 patients (sensitivity 93.9%), whereas thyroglobulin levels were elevated in 18 patients (sensitivity 54.5%). FDG PET was positive in 14 of 15 metastatic cancer patients with normal thyroglobulin levels. In 20 of 21 patients in remission, FDG PET was negative (specificity 95.2%), whereas thyroglobulin levels were normal in 16 patients (specificity 76.1%). The sensitivity and specificity of FDG PET were significantly higher than those of serum thyroglobulin. In patients with negative 1311 scans, FDG PET detected cervical lymph node metastasis in 87.9%, lung metastasis in 27.3%, mediastinal metastasis in 33.3% and bone metastasis in 9.1%. In contrast, among 117 patients with 131I scan-positive functional metastases, 131I scan detected cervical lymph node metastasis in 61.5%, lung metastasis in 56.4%, mediastinal metastasis in 22.2% and bone metastasis in 16.2%. In all 5 patients in whom thyroglobulin was false-negative with negative antithyroglobulin antibody, PET showed increased 18F-FDG uptake in cervical lymph nodes, mediastinal lymph nodes, or both. Among patients with increased 18F-FDG uptake only in the cervical lymph nodes, the nodes were dissected in 11. Metastasis was confirmed in all, even in normal-sized lymph nodes.

CONCLUSION

FDG PET scan localized metastatic sites in 131I scan-negative thyroid carcinoma patients with high accuracy. In particular, it was superior to 131I whole-body scan and serum thyroglobulin measurement for detecting metastases to cervical lymph nodes. FDG PET was helpful for determining the surgical management of these patients.

Hormone-dependent regulation of intercellular adhesion molecule-1 gene expression: cloning and analysis of 5'-regulatory region of rat intercellular adhesion molecule-1 gene in FRTL-5 rat thyroid cells

Intercellular adhesion molecule-1 (ICAM-1) has been suggested to play an important role in the perpetuation of autoimmune thyroid disease. To clarify the regulation of ICAM-1 gene in thyroid cells, we investigated ICAM-1 expression in the FRTL-5 thyroid cell model and defined several elements in the 5'-regulatory region that are important for transcriptional regulation of the rat ICAM-1 gene. Cells maintained in medium with 5% serum but without hydrocortisone, insulin, and thyrotropin (TSH) express the highest levels of ICAM-1 RNA. TSH/forskolin downregulate ICAM-1 RNA levels independent of the presence or absence of hydrocortisone or insulin. Moreover, TSH/forskolin decrease ICAM-1 RNA levels that are maximally induced by two cytokines: 100 ng/mL tumor necrosis factor-alpha (TNF-alpha) or 100 U/ml interferon-gamma (IFN-gamma). The effect of TSH/forskolin, as well as TNF-alpha and IFN-gamma, on ICAM-1 RNA levels is transcriptional. Thus, we cloned a 1.8-kb fragment of the 5'-flanking region of the rat ICAM-1 gene, upstream of the translational start site, and showed that TNF-alpha or IFN-gamma caused a 3.5- and greater than 12-fold increase respectively, in its promoter activity, when linked to a luciferase reporter gene and stably transfected into FRTL-5 cells. TSH or forskolin, in contrast, halved the activity of the full length chimera within 24 hours and significantly suppressed the TNF-alpha and IFN-gamma-induced increase (>50%; p < 0.02). Using 5'-deletion mutants, we located the element important for the TNF-alpha effect between -431 and -175 bp; we additionally show that deletion of a NF-kappaB core element within this region, TTGGAAATTC (-240 to -230 bp), causes the loss of TNF-alpha inducibility. The effect of IFN-gamma could be localized between -175 bp and -97 bp from the start of translation. This region contains 2 regulatory elements known to be involved in IFN-gamma action in other eukaryotic cells, an IFN-gamma activated site (GAS), -138 to -128 bp, and Spl site, -112 to -108 bp. Deletion of the 10 bp GAS sequence resulted in the complete loss of IFN-gamma induction of pCAM-175 promoter activity. TSH and forskolin action was also mapped between -175 bp and -97 bp from the start of translation. The mutant construct, pCAM-175delGAS mutl, which has no GAS sequence, exhibited no TSH-mediated suppression of promoter activity. We thus show that TSH/cAMP can downregulate ICAM-1 gene expression and inhibit the activity of cytokines (TNF-alpha and IFN-gamma) to increase ICAM-1 gene expression in FRTL-5 thyroid cells. We also localized elements on the 5'-flanking region of ICAM-1 important for these actions. We propose that this TSH/cyclic adenosine monophosphate (cAMP) action is a component of the mechanism to preserve self-tolerance of the thyroid during hormone-induced growth and function of the gland, and it may attenuate cytokine action during inflammatory reactions.

Expression of the functional extracellular domain of human thyrotropin receptor using a vaccinia virus system: its purification and analysis of autoantibody binding

We produced substantial amount of the extracellular domain of the human TSH receptor (TSHRE) that has a tag of six histidines at C-terminus as a soluble form in the human cell line HeLa using a vaccinia virus system. By sequential nickel-chelating and lentil lectin column chromatography, TSHRE was purified to about 70% purity, with the recovery of around 0.1-0.2 mg TSHRE/L culture (5 x 10(8) cells/liter culture). The purified TSHRE interacted with TSH as well as Graves' autoantibodies to TSHR. However, the affinity of TSHRE for TSH was much lower than that of intact TSHR. The IC50 value for inhibition of TSH-dependent cAMP synthesis by TSHRE was about 10(-8) mol/L. Most importantly, the purified TSHRE inhibited the binding of the IgG of Graves' patients to thyroid membrane. About 1 microg/mL (2 x 10(-8) mol/L) TSHRE neutralized most of the autoantibody activity of patients' sera tested in the TSH binding inhibitory immunoglobulin (TBII) assay. Moreover, this protein neutralized thyroid stimulatory antibody-induced cAMP synthesis with an IC50 of 1 x 10(-9) mol/L and completely at 0.5-1 microg/mL (1-2 x 10(-8) mol/L). In the simple enzyme-linked immunosorbent assay, the TSHRE immobilized on the wells coated with nickel showed significantly higher binding with the IgGs from Graves' patients than in those from normal individuals. This autoantibody-reactive TSHRE will be useful for further studies on the diagnosis, pathogenesis, and the development of therapy of Graves' disease.

Two Graves' disease patients who spontaneously developed hypothyroidism after antithyroid drug treatment: characteristics of epitopes for thyrotropin receptor antibodies

Few reports have identified blocking thyrotropin receptor antibodies (TSHRAbs) as a pathogenic mechanism explaining spontaneous hypothyroidism after antithyroid drug (ATD) treatment of Graves' disease. Here we report 2 Graves' patients who showed different courses of hypothyroidism after ATD treatment. The first patient had Graves' hyperthyroidism and was treated with ATD for 1 year. After a short period of euthyroidism, she developed permanent hypothyroidism with blocking TSHRAb. The second patient became euthyroid after 1 year of ATD treatment. After 3 years, however, she presented with hypothyroidism with blocking TSHRAb activity. Her hypothyroidism was transient, and restoration of euthyroidism was followed by disappearance of blocking TSHRAb. Blocking and stimulating TSHRAbs activities of these 2 patients were serially measured using Chinese hamster ovary (CHO) cells transfected with wild-type human TSHR (CHO-hTSHR) and 2 TSHR chimeras with residues 8-165 (Mc1+2) or 90-165 (Mc2) substituted by equivalent residues of the luteinizing hormone/chorionic gonadotropin receptor (LH/CGR). During their hypothyroid phases, blocking TSHRAbs activities were positive in all 3 kinds of assays and stimulating TSHRAbs activities were negative in CHO-hTSHR or in Mc 1+2 assay. Mc2 stimulating TSHRAb activity was detected in sera of hypothyroid phase of the second patient who had transient hypothyroidism but not in the first whose hypothyroidism was permanent. In these 2 cases, we demonstrate the causative role of blocking TSHRAb in the development of hypothyroidism after ATD treatment in Graves' patients. Interestingly, the difference in the course of blocking TSHRAb-induced hypothyroidism was associated with the difference in epitope reactivities of TRAb during hypothyroid phase that developed after ATD treatment of Graves' disease.

Different bioactivities of human thyrotropin receptors with different signal peptides

For investigation of the mechanism and pathogenesis of Graves' disease, availability of a large amount of functional human thyrotropin receptor (TSHR) capable of recognition by Graves' autoantibodies is essential. Many attempts have been made to produce the extracellular domain of TSH receptor (TSHRE) in a baculovirus expression system. However, the receptor is expressed as an insoluble form and the refolded protein is often not recognized by the autoantibodies. In this study, we found that the TSHRE expressed with its own signal peptide (VL3-RE) in insect cells is retained inside of the cells and found in both soluble and insoluble fractions in equal proportion. The signal peptide is not removed. The receptor in the soluble fraction is not recognized by either TSH or Graves' autoantibodies. The TSHRE with an insect-specific mellitin signal peptide (Mel-RE) is also retained inside of the cell and found in both the soluble and insoluble fractions in equal proportion. However, the signal peptide is removed and the receptor is recognized by the Graves' autoantibodies but not by TSH. Also, the amount of Mel-RE expressed was 5-10-fold higher than VL3-RE. The two receptor preparations apparently have the same degree of glycosylation as evidenced by the same increased mass (approximately 15 kDa) due to glycosylation. However, the two receptors have different affinity for an anion-exchange resin and different pI. Deglycosylated receptors have the same pI. This suggests that the composition of sugars may be different. Taken together, the results suggest that the two receptors are modified and folded differently by different pathways due to the presence of different signal peptides. Use of an insect-specific signal peptide is recommended for expression of TSHR that is recognized by Graves' autoantibodies in a baculovirus system.

A new point mutation (3426, A to G) in mitochondrial NADH dehydrogenase gene in Korean diabetic patients which mimics 3243 mutation by restriction fragment length polymorphism pattern

Mitochondrial tRNA(Leu)(UUR) gene mutation is one of the candidates in the pathogenesis of NIDDM. Especially the 3243 (A-->G) mutation is associated with the maternally-inherited diabetes and deafness. To evaluate the prevalence and characteristics of the 3243 point mutation in Koreans, we screened 433 Korean diabetic patients (220 men and 213 women). Genomic DNA was extracted from peripheral white blood cells and PCR was carried out with mitochondrial DNA primers (3130-3149, 3558-3539) encompassing the 3243 position. After digestion with Apa-1, five subjects showed polymorphism suggesting 3243 point mutation but when we directly sequenced the amplified DNA with an automatic sequencer, only 2 of the 5 patients were shown to have 3243 (A-->G) mutation and the other 3 subjects had 3426 (A-->G) mutation rather than 3243 mutation. Two diabetic patients with 3243 mutation were lean (BMI = 14.4, 17.0 kg/m2), had relatively lower fasting C-peptide concentrations (0.9 ng/ml each), and required insulin for management. In contrast, those with 3426 point mutation were not lean (BMI = 22.6-28.0 kg/m2), had relatively higher C-peptide levels (3.9-5.4 ng/ml), and could be managed with oral hypoglycemic agents. None of the 5 patients had deafness. In conclusion, the prevalence of 3243 point mutation in Korean diabetic patients was approximately 0.5% and we found a new mutation mimicking 3243 mutation by PCR-RFLP (restriction fragment length polymorphism) pattern. We suggest that sequencing of the PCR product or designing smaller PCR fragment size to enhance the specificity may help to identify the exact location of the point mutation.

Characterization of monoclonal thyroid-stimulating and thyrotropin binding-inhibiting autoantibodies from a Hashimoto's patient whose children had intrauterine and neonatal thyroid disease

A multiplicity of TSH receptor autoantibodies (TSHRAbs) have been characterized after subcloning heterohybridomas produced from the lymphocytes of a patient who has Hashimoto's thyroiditis and had three children with intrauterine or neonatal hyperthyroidism. Twelve clones produced stimulating TSHRAbs that increased cAMP levels and iodide uptake in rat FRTL-5 thyroid cells and increased cAMP levels in Chinese hamster ovary (CHO) cells transfected with the human TSHR; like 95% of Graves' stimulating TSHRAbs, all 12 have their functional epitope on the N-terminus of the TSHR extracellular domain, requiring residues 90-165 for activity. All 12 bind to human thyroid membranes in the absence, but not the presence, of TSH, but are only weak inhibitors of TSH binding in assays measuring TSH binding-inhibiting Igs (TBIIs). In contrast, 8 different clones produced TSHRAbs that did not increase cAMP levels, but, instead, exhibited significant TBII activity. Four inhibited the ability of TSH or a stimulating TSHRAb to increase cAMP levels and had their functional epitope on the C-terminal portion of the TSHR external domain, residues 261-370, mimicking the properties of blocking TSHRAbs that cause hypothyroidism in patients with idiopathic myxedema. The 4 other TBIIs inhibited the ability of TSH, but not that of a stimulating TSHRAb, to increase cAMP levels, like TBIIs in Graves' patients. The functional epitope for 3 of these Graves'-like TBIIs was residues 90-165; the functional epitope for the fourth was residues 24-89. The fourth also increased arachidonic acid release and inositol phosphate levels in FRTL-5 thyroid cells and exhibited conversion activity, i.e. the ability to increase cAMP levels in the presence of an anti-human IgG. Thus, this TBII exhibited signal transduction activity, unlike the other 3 Graves'-like TBIIs. The patient, therefore, has stimulating TSHRAbs and 3 different types of TBIIs, each with different functional properties and different epitopes on the TSHR.

Labeling reactions applicable to chromatography and electrophoresis of minute amounts of proteins

Chromatography and electrophoresis have become extremely valuable and important methods for the separation, purification, detection and analysis of biopolymers and HPLC/HPCE may become the premier, preferable approaches for both qualitative and quantitative analyses of most proteins, especially from recombinant materials. This includes smaller peptides, polypeptides, proteins, antibodies and all types of protein or antibody-conjugates (antibody-enzyme, protein-fluorescent probe, antibody-drug and so forth). This entire Topical Issue of Journal of Chromatography emphasizes the application of chromatography and electrophoresis to protein analysis. This particular review deals with approaches to the selective tagging or labeling of proteins at trace (minute) levels, again using either chromatography or electrophoresis, with the emphasis on modern HPLC/HPCE methods and approaches. We discuss here both pre- and post-column labeling methods and reagents, techniques for realizing selective labeling of proteins or antibodies, applicable approaches to protein preconcentration in both HPLC and HPCE areas and in general, methods for improving (lowering) detection limits for proteins utilizing chemical or physical derivatization and/or preconcentration techniques. There are really two major goals or emphases in that which follows: (1) methods for selective labeling of proteins prior to or after HPLC/HPCE and (2) labeling of proteins at trace levels for improved separation-detection and lowered detection limits. We discuss here a large number of specific references related to both pre- and post-column/capillary derivatizations for proteins, as well as methods for improved detectability in both HPLC and HPCE by, for example, analyte preconcentration on a solid-phase extractor or membrane support, capillary isotachophoresis and other methods. Selective reactions or derivatizations on proteins refers to the ability to tag the protein at specific (e.g. reactive amino sites) in a controlled manner, with the products having the same number of tags all at the very same site or sites. The products are all the same species, having the same number of tags at the same locations on the protein. Selective reactions can also refer to the idea of tagging all of the protein sample at only a single, same site or at all available sites, homogeneously.

High-performance capillary electrophoresis of a fermentation-derived cyclic peptide analog, animal growth promoter

We have developed HPCE methods for the analysis of sulfomycin (trivial name) and related compounds (code name, crude material = U82127 = I), which is an animal growth promoter derived from a fermentation beer. The crude material, I, isolated from the fermentation consisted of more than 40 components which were not completely separated by conventional HPLC. Thus, as a complementary analysis method, we have optimized HPCE conditions for I using various capillaries including uncoated, coated, and packed using various buffers. The optimized HPCE conditions were obtained with an uncoated fused-silica capillary and a buffer that consisted of 30 mM Tris-tricine, 10 mM SDS, 10 mM NaCl and 20% MeOH, pH 8.0. Using these HPCE conditions, we were able to separate the one main component collected from the HPLC effluent into two or three components. In order to identify the main components of the fermentation product, an off-line HPLC-HPCE-MS analysis for I was performed. From the MALDI-TOF-MS results, the separated components collected from HPCE had different molecular masses. Four lots of I samples having different characteristics were also analyzed by HPCE to investigate lot-to-lot differences in peak profiles. The four lots of I were found to have very similar peak profiles. In this paper, I refers to the crude fermentation product and sulfomycin to the purified, major HPLC component of I.

Clinical significance of hepatic visualization on iodine-131 whole-body scan in patients with thyroid carcinoma

The purpose of this study was to evaluate the frequency and clinical significance of diffuse hepatic uptake on 131I whole-body scan in 399 patients (53 males, 348 females) with well-differentiated adenocarcinomas of the thyroid.

METHODS

Two hundred and ninety-one diagnostic scans were performed 2 days after the administration of 74-370 MBq (2-10 mCI) 131I, and 824 post-therapy scans were done 3-5 days after the administration of 1.11-7.4 GBq (30-200 mCI) 131I. There was no evidence of liver metastasis in these patients. Liver and thyroid visualization on each 131I scan were graded from 0-4. To evaluate the incorporation of radioiodine to thyroglobulin and thyroid hormones, a patient's serum was extracted by 80% ethanol/20% trichloroacetic acid solution and analyzed by silica gel thin-layer chromatography.

RESULTS

Diffuse hepatic uptake (> Grade 2) was definitely seen in 239 of 399 (59.9%) of the patients and 397 of 1115 (35.6%) of the studies. In the diagnostic scans, 36 (12.0%) showed uptake in the liver. In post-therapy scans, however, the incidence of liver uptake increased according to increased doses of 131I (39.1% with 1.11 GBq, 61.5% with 2.775-3.7 GBq and 71.3% with 5.55-7.4 GBq). The more that uptake appeared in the residual thyroid, the more it appeared in the liver. There were 13 patients whose scans showed metastatic and liver uptake without any thyroid uptake. Fifteen patients showed diffuse liver uptake without uptake by the thyroid or metastasis. Follow-up studies of seven of these patients revealed metastatic lesions. Liver uptake on scan related to the fraction of 131I-labeled thyroglobulin in the serum.

CONCLUSION

Diffuse liver uptake indicated functioning thyroid remnant or metastasis. In a few cases, liver uptake without uptake by the thyroid or metastasis on whole-body scans suggests hidden metastases.

Changes in epitopes for thyroid-stimulating antibodies in Graves' disease sera during treatment of hyperthyroidism: therapeutic implications

To determine whether there are changes in epitope recognition by stimulating TSH receptor antibodies (TSHRAbs) during treatment of hyperthyroidism and to evaluate the clinical relevance of such changes, we serially measured the activity of IgG preparations from 39 patients with Graves' disease over an 8-month period. To measure epitope changes of the stimulating TSHRAbs, we used Chinese hamster ovary (CHO) cells transfected with wild-type human TSHR (hTSHR) or TSHR chimeras with residues 90-165 (Mc2) substituted by equivalent residues of the rat LH/CG receptor. When initially examined, 37 of the 39 patients had significant stimulating TSHRAb activity measured with wild-type CHO-hTSHR cells. Serial measurements of stimulating TSHRAb activity in Mc2 chimera-transfected cells divided the 39 patients into three distinct groups. Thus, 10 patients (heterogeneous epitope group) exhibited low but significant activity in Mc2 chimera assays at the start of the study; 10 patients who were initially negative in Mc2 chimera assays remained negative (persistently homogeneous epitope group); and 19 patients who were initially negative in Mc2 chimera assays became transiently or persistently positive during treatment, despite a simultaneous decrease in TSHRAb activity measured with wild-type TSHR (changing epitope group). The functional stimulating TSHRAb epitope thus changed from residues 90-165 to residues outside this region in the last group, which comprises nearly two-thirds of the initially Mc2-negative patients (19 of 29) and one-half of all patients (19 of 39). Patients in the changing epitope group responded more quickly and to lower doses of methimazole than patients in the persistently homogeneous epitope group, behaving in this respect exactly as the patients in the heterogeneous epitope group. Additionally, although the decrease in stimulating TSHRAb activities during the 8-month treatment period was similar in the two groups, the thyrotropin binding inhibitor immunoglobulin (TBII) activities decreased more rapidly in patients in the persistently homogeneous epitope group than in patients in the changing epitope group (P < 0.05). There were no differences in initial stimulating TSHRAb or TBII activities, degree of hyperthyroidism, goiter size, or prior duration of symptoms between the persistently homogeneous epitope group and changing epitope group. In summation, we show that the epitopes of stimulating TSHRAbs in Graves' disease patients may change during their clinical course or treatment period, and that the change is from antibodies recognizing N-terminal TSHR residues 90-165 to antibodies recognizing other regions of the TSHR. We also show that the development of stimulating TSHRAbs with this heterogeneous epitope or their presence at the initial screening for disease activity seems to be associated with increased responsiveness to antithyroid drug therapy. We suggest, therefore, that Mc2 chimera assays may be useful to predict the response of patients to antithyroid drug therapy.

International differences in approaches to 131I therapy for Graves' disease: case selection and restrictions recommended to patients in Japan, Korea, and China

Members of the American Thyroid Association (ATA), European Thyroid Association (ETA), Japan Thyroid Association (JTA), Korean Thyroid Association (KTA), and Chinese Thyroid Association (CTA) were surveyed independently through an identical questionnaire on their management of Graves' disease. One of the major purposes of the survey was to determine how expert thyroidologists in different regions of the world use three different therapies available for a typical Graves' patient as well as for clinical variations provided. In this report, we summarized, contrasted, and interpreted the results of the surveys in three Asian countries by focusing on therapeutic preference of radioiodine. For the index patient with hyperthyroidism due to Graves' disease, radioiodine was the therapy of choice for 69% of ATA respondents but only 22%, 22%, 11%, and 11% of ETA, CTA, JTA, and KTA respondents, respectively. The goal of radioiodine therapy in Asian countries was to restore the euthyroid state. For the case of recurrence after surgery, there was consensus on choosing radioiodine among all countries surveyed. To interpret the reluctance to advocate radioiodine therapy for a typical Graves' patient in Japan, a new survey concerning the current trends in radioiodine therapy in Japan was conducted among clinical members of the JTA. The phobia of radiation and stringent safety rules for radioactive pharmaceuticals were the two major reasons found. Nevertheless, the percentage of JTA respondents who aim for the euthyroid of hypothyroid state by radioiodine therapy for typical Graves' significantly increased compared with respondents to the former survey in 1988. Moreover, a considerable number of JTA members believe that more radioiodine therapy should be applied for achievement of the rapid improvement of hyperthyroidism, for convenience, and for medical cost benefits.

Identification of the peptides that inhibit the stimulation of thyrotropin receptor by Graves' immunoglobulin G from peptide libraries

Graves' disease is characterized by the overproduction of thyroid hormones due to the persistent stimulation of TSH receptor by autoantibodies. To determine the epitopes recognized by the autoantibodies, an enzyme-linked immunosorbent assay was developed that uses the human TSH receptor extracellular domain attached to plastic wells. The total IgG from some of the Graves' patients interacted with the bound TSH receptor (TSHR) at a significantly higher level than that in normal individuals. The IgG preparation that showed the highest binding activity was used for the identification of peptide sequences that prevent binding of Graves' IgG to TSHR from positional scanning synthetic peptide combinatorial libraries. A hexapeptide mixture, X1X2FDDA (X1 is a mixture of E, M, and Y; X2 is a mixture of E, H, and T), was found to be effective for inhibiting the binding of Graves' IgG to the TSHR. Further fractionation of X1X2FDDA showed that the following three sequences were highly effective: EEFDDA, ETFDDA, and EHFDDA. The second position of the three peptides did not appear to be important. The peptides also inhibited the cAMP synthesis induced by IgG of four of eight patients with Graves' disease tested. The synthesis of cAMP by TSH was also inhibited by the peptides to some extent. The peptide sequences most likely mimic a part of the conformational epitopes recognized by at least one class of Graves' IgG.

Immunodetection approaches and high-performance immunoaffinity chromatography for an analogue of bovine growth hormone releasing factor at trace levels

An indirect detection method using high-performance immunoaffinity chromatography (HPIAC) was used to measure low levels of an analogue of bovine Growth Hormone Releasing Factor (bGHRF). An antibody (Ab) labelled with alkaline phosphate (ALP) was incubated with the bGHRF analogue to perform a complex between the antigen (Ag) and the antibody-enzyme (Ab-En) conjugate. The complex was then injected onto a cartridge containing an immobilized Ag affinity support. Species which were not recognized by the affinity cartridge, i.e. eluted, were then directly combined, via a connecting tee, with a buffer containing a substrate. Incubation proceeded on-line, inside a knitted reactor coil, under conditions of constant flow. The subsequent generation of a fluorescently active substrate product was detected by conventional means. The assay described has a linear response region from 1.0 to 25 ng of the bGHRF analogue and a limit of detection of 0.60 ng (1.7 x 10(2) femtomole, 30 p.p.b.). This approach was compared against a method in the antigen/Ab-En complex was injected onto a immobilized Ab affinity cartridge to form an antibody-antigen conjugate sandwich and subsequent stop-flow incubation with substrate.

Immunochromatographic analysis of bovine growth hormone releasing factor involving reversed-phase high-performance liquid chromatography-immunodetection

We have developed high-performance immunoaffinity chromatography (HPIAC) methods for the detection and quantitation of bovine growth hormone releasing factor (GHRF), which could also be applicable to its metabolites in biofluids. These approaches have involved a combination of IAC using immobilized antibody (Ab) to GHRF, together with reversed-phase high-performance liquid chromatography (RP-HPLC) separations of initially isolated and concentrated protein, followed by selective detection, involving on-line immunodetection (ID) schemes. ID methods involved HPIAC supports of the Ab, together with synthesized Ab-fluorescein isothiocyanate conjugates. We have demonstrated optimization methods for each step of the entire hyphenated technique (IAC-HPLC-ID), and then actually quantitated GHRF using this overall system. The minimum detectable concentration was about 1 ng/5 ml (200 ppt) with fluorescence detection (excitation wavelength, 490 nm; emission wavelength, 510-650 nm). We have also tested a single blind, spiked biological sample (bovine plasma), spiked with a known level of GHRF. Accuracy (7.4%) and precision (S.D. = +/- 22%) were quite acceptable for a double immunoassay method.

Relationships between angiotensin I converting enzyme gene polymorphism and renal complications in Korean IDDM patients

OBJECTIVES

The prognosis of IDDM is mainly dependent on complicated diabetic nephropathy which is probably determined by both metabolic abnormalities and genetic predisposition. Angiotensin I converting enzyme (ACE) regulates systemic and renal circulations through angiotensin II formation and kinins metabolism. The insertion(i)/deletion(D) polymorphism in intron 16 of ACE gene is strongly associated with ACE levels, and subjects homozygote for deletion (genotype DD) have the highest plasma values. Recently, it was reported that I/D polymorphism of ACE gene is associated with diabetic nephropathy in Caucasian IDDM patients. We studied the relationship between the ACE gene polymorphism and diabetic nephropathy in Korean IDDM patients.

METHODS

The study population consisted of 59 IDDM patients (duration > 5 yrs) and 107 control subjects. IDDM subjects were divided into 2 groups according to the presence or absence of diabetic nephropathy (with nephropathy: n = 31, without nephropathy: n = 28). After extraction of genomic DNA from peripheral blood leukocytes, PCR was performed using the sense primer (5' -GCC CTG CAG GTG TCT GCA GC-3') and anti-sense primer (3'-TGC CCA TAA CAG TGC TTC ATA -5'), respectively. The PCR products were electrophoresed in 2% agarose gels, and DNA was visualized directly with ethidium bromide staining.

RESULTS

Frequencies for II, ID and DD genotypes were similar in IDDM subjects and controls (23: 19:17 vs 49:41:17, p = 0.142) and derived allele frequencies for I and D alleles were similar in both groups (0.551:0.449 vs 0.649:0.351, p = 0.098). The ACE genotype distributions were not different in diabetic subjects with or without nephropathy (12:9:10 vs 11:10:7, p = 0.78) and derived allele frequencies were also similar (0.532:0.468 vs 0.571:0.429, p = 0.81).

CONCLUSION

The I and D allele frequency in our controls was different compared to ACE allele frequencies of Caucasian populations, but very similar compared to those of Chinese or Japanese subjects. We found that I/D polymorphism of ACE gene is not implicated in the diabetic nephropathy of Korean IDDM patients and may be explained by ethnic differences.

Epitopes for thyroid-stimulating antibodies in Graves' sera: a possible link of heterogeneity to differences in response to antithyroid drug treatment

To evaluate the extent and clinical relevance of epitope heterogeneity for stimulating TSH receptor antibodies (TSHRAbs), we measured the activity of IgG preparations from 66 untreated patients with Graves' disease using Chinese hamster ovary (CHO) cells transfected with wild-type human TSHR and two TSHR chimeras with residues 9-165 (Mc1 + 2) or 90-165 (Mc2) substituted by equivalent residues of the LH/CG receptor. IgG from 68% of patients lose all of the stimulating TSHRAb activity with the chimeras; IgG from 27% lose most of the activity. Thus, we show that 95% of patients have stimulating TSHRAbs that require epitopes on the N-terminal portion of the extracellular domain of the TSHR and demonstrate the importance of epitopes within residues 90-165 for the first time. Heterogeneous epitope distribution, residual activity with one or both chimeras, i.e. with epitopes other than on the N-terminus of the TSHR, occurred in 21 patients (group A). Forty-five patients with homogeneous epitope distribution (group B) had stimulating TSHRAbs that depended only on epitopes on the N-terminus of the TSHR. Patients in group A were more likely to become euthyroid during antithyroid drug therapy and to do so more quickly than group B patients. The CHO-human TSHR cell system described herein appears to be as effective as the FRTL-5 rat thyroid system in stimulating TSHRAb detection; however, the two systems appear to measure different antibody populations in about 30% of cases. Further, stimulating TSHRAb activities measured in the FRTL-5 system tend to correlate better with goiter size and 99mTc pertechnetate uptake, whereas stimulating activities measured in the CHO-human TSHR/chimera system correlate better with free T4 and T3 levels.

High prevalence and little change in TSH receptor blocking antibody titres with thyroxine and antithyroid drug therapy in patients with non-goitrous autoimmune thyroiditis

OBJECTIVE

We have reevaluated the prevalence and pathogenetic importance of TSH receptor blocking antibodies (TRBAb) in autoimmune hypothyroidism, and investigated the changes in TRBAb activities during thyroxine and antithyroid drug treatment.

DESIGN

Serum TSH binding inhibitor immunoglobulin (TBII) and thyroid stimulation blocking antibody (TSBAb) were measured serially in all patients with non-goitrous autoimmune thyroiditis (AT) and measured monthly during methimazole treatment in 6 patients.

PATIENTS

Ninety patients with non-goitrous AT and 95 patients with goitrous AT were entered consecutively into this study. All patients with non-goitrous AT were treated with thyroxine and followed at intervals of 6 months for 2 years initially and then yearly intervals. The duration of follow-up was 1-8 years. Six patients from the TRBAb-positive non-goitrous AT group who were treated with thyroxine were randomly selected and given additional treatments with methimazole (40 mg per day) for 6 months.

MEASUREMENTS

Serum TBII was measured by a radioreceptor assay, TSBAb by using FRTL-5 cells, and antithyroid peroxidase and antithyroglobulin antibodies by radioimmunoassay.

RESULTS

The prevalences of TBII and TSBAb is non-goitrous AT were 47.8 and 58.9%, respectively, which were significantly higher than those in goitrous AT (6.3% for TBII, 10.5% for TSBAb). All but one patient showed persistent TBII and TSBAb activities during the thyroxine treatment for up to 8 years. A high dose of methimazole (40 mg per day) did not affect the titres of TBII and TSBAb in 5 out of 6 patients with non-goitrous AT tested. However, antithyroid peroxidase and antithyroglobulin antibodies activities were significantly decreased during the methimazole treatment.

CONCLUSION

The high prevalence of TSH receptor blocking antibodies (TRBAb) suggests that TRBAb may play a major role in the development of hypothyroidism and thyroid atrophy in the vast majority of patients with non-goitrous autoimmune thyroiditis. Most TRBAb activities are stable for at least 8 years and are now affected by thyroxine and antithyroid drug treatment.

Insulin restores fatty acid composition earlier in liver microsomes than erythrocyte membranes in streptozotocin-induced diabetic rats

Alterations of fatty acid composition have been observed in a number of tissues in both experimental and human diabetes. Suppression of delta 6 desaturase in the liver, a key enzyme of fatty acid desaturation, has been reported to be responsible for these phenomena. We measured the fatty acid composition of the liver and the erythrocytes, and examined delta 6 desaturase activities to compare the effect of short-term insulin therapy on the tissues with and without delta 6 desaturase, ie., the liver and the erythrocytes using streptozotocin (STZ)-induced diabetic rats. Linoleic (P < 0.05), palmitic (P < 0.01) and docosahexaenoic (DHA) acid (P < 0.01) were higher and arachidonic (P < 0.01) and oleic acid (P < 0.01) were lower in the liver microsomes of diabetic rats when compared to those in control rats. These alterations were partly reversed with insulin treatment. In the erythrocyte membrane, linoleic (P < 0.01) and stearic acid (P < 0.05) were higher, and palmitic (P < 0.05), palmitoleic (P < 0.01), and arachidonic acid (P < 0.01) were lower in diabetic rats. In contrast to the case of the liver microsomes, however, these alterations were persistently observed after 48 h of insulin treatment. The activities of delta 6 desaturase in diabetic rats were 68% of those of controls (P < 0.05), and increased to 119% of controls after insulin treatment. These results show that insulin restores the fatty acid composition earlier in the liver microsome than in the erythrocyte membrane in STZ-induced diabetic rats. The erythrocyte membrane would not be suitable for the investigation dealing with rapid changes of fatty acid composition.

Effect of growth factors on the expression of proto-oncogenes c-fos and c-myc in FRTL-5 cell line

This study was performed to prove the hypothesis that oncogene expressions would have the same patterns with those of cellular growth to growth factors in FRTL-5 cells. Ribonucleic acids of FRTL-5 were extracted at 15', 30', 60' and 120' after administration of growth factors to quiescent FRTL-5, and blotted to the nitrocellulose membrane. They were hybridized with radiolabelled c-fos, c-myc and beta-actin probes. Hybridized dot blots were autoradiographed and the amount of radioactivity was measured by densitometry. Densitometric readings were used as the indices of oncogene expressions. Expressions of c-fos and c-myc were more prominent in combined administrations of TSH (10 mU/ml) and IGF-I (100 ng/ml) or IgG of Graves' disease (Graves' IgG; 1 mg/ml) and IGF-I than in combined administration of TSH and Graves' IgG. IgG of primary myxedema suppressed oncogene expressions by TSH or Graves' IgG, but not by IGF-I. From the above results, it was suggested that expressions of c-fos and c-myc to growth factors would have similar patterns with those of cell growth to growth factors in FRTL-5, and the actions of TSH and Graves' IgG would be manifested through same signal transduction system, but IGF-I would be manifested by its own.

The cytokines, interleukin-1 beta, interleukin-6 and interferon-gamma upregulate the expression of intercellular adhesion molecule-1(ICAM-1) in rat thyroid cell line, FRTL-5

OBJECTIVES

Recently, the role of adhesion molecules in the immune system has been recognized. ICAM-1 plays an important role in a variety of inflammatory and immune mediated mechanisms, including recruitment and targeting of lymphocytes. We observed the effects of cytokines on expression of rat homologue of human intercellular adhesion molecule-1 in rat thyroid cell line, FRTL-5.

METHODS

We have examined expression of rat intercellular adhesion molecule-1 (ICAM-1, CD54), a homologue of human intercellular adhesion molecule-1, by immunocytochemistry (immunoperoxidase staining) in the continuously growing rat thyroid cell line, FRTL-5.

RESULTS

Low level of ICAM-1 expression was noted at basal condition and this basal expression was not influenced by thyrotropin. Expression in rat homologue of ICAM-1 is increased by interferon-gamma, interleukin-1 beta and interleukin-6 with a dose dependent manner.

CONCLUSION

These results show that a pure line of rat thyroid cells can express an ICAM-1 homologue and this is directly enhanced by cytokines such as rat interferon-gamma, human interleukin-1 beta and interleukin-6. Expression of this homologue is partially responsible for lymphocyte adhesion to thyroid cells, which is likely to be a major event in T cell recognition of thyroid antigens in autoimmune thyroiditis.

The tumor necrosis factor beta * 1 allele is linked significantly to HLA-DR8 in Koreans with atrophic autoimmune thyroiditis who are positive for thyrotropin receptor blocking antibody

The localization and functional characteristics of tumor necrosis factor(TNF) beta gene raise the possibility that it may be involved in the susceptibility to autoimmune thyroid diseases. To investigate whether a TNF beta gene polymorphism is associated with autoimmune thyroiditis, we analyzed the TNF beta gene polymorphism with the restriction enzyme NcoI in 48 Korean patients with atrophic autoimmune thyroiditis [23 were found to be thyrotropin binding inhibitor immunoglobulin(TBII) positive, 25 TBII negative], 52 goitrous autoimmune thyroiditis, and 129 healthy controls. Two TNF beta alleles were identified from the restriction fragment length polymorphism studies of amplified genomic DNA. In atrophic autoimmune thyroiditis patients positive for TBII, 7 of 23 patients were homozygous for the TNF beta * 1 allele, 3 were homozygous for the TNF beta * 2 allele, and 13 were TNF beta * 1/2 heterozygous compared to controls(P = 0.20). Also, there were no associations between the TNF beta gene polymorphism and either TBII-negative atrophic autoimmune thyroiditis or goitrous autoimmune thyroiditis. Of the HLA-class II antigens, the frequency of HLA-DR8 was significantly greater among the 23 Korean patients with TBII-positive atrophic autoimmune thyroiditis compared to control subjects (Pc = 0.003). When the HLA-DR8 positive patients with TBII-positive atrophic autoimmune thyroiditis and controls were analyzed separately, the DR8 positive patients with TBII-positive atrophic autoimmune thyroiditis had more homozygotes for the TNF beta * 1 allele(6/12, 50.0%) and no homozygotes for the TNF beta * 2 allele, as compared to the DR8 negative patients with TBII-positive atrophic autoimmune thyroiditis and DR8 positive controls(P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Negative correlation between the conversion of thyrotropin receptor-bound blocking type thyrotropin receptor antibody to the stimulating type by anti-human IgG antibodies and the biological activity of blocking type thyrotropin receptor antibody

It has been reported that receptor-bound blocking type TSH receptor antibody (TRAb) can be converted to the stimulating type by anti-human IgG antibodies. To evaluate the relationship between the conversion of receptor-bound blocking type TRAb to the stimulating type and the biological activity of blocking type TRAb, we compared converting activities of blocking type TRAb from 10 patients with primary nongoitrous hypothyroidism with both the doses of blocking type TRAb which show 50% inhibition of 125I-bTSH binding to the TSH receptor and those which show 50% inhibition of TSH-stimulated cAMP production in cultured rat thyroid cells (FRTL-5). The additions of anti-human IgG antibody to FRTL-5 cell-bound blocking IgGs resulted in the increase in cAMP production in a dose-dependent manner and the converting activities (percent increase of cAMP production) also depended on the doses of blocking IgGs. The converting activities were significantly correlated with the doses of blocking IgGs which showed 50% inhibition of 125I-bTSH binding to the TSH receptor (r = 0.71, p = 0.011). And these converting activities were also significantly correlated with the doses of blocking IgGs which showed 50% inhibition of TSH-stimulated cAMP increase (r = 0.81, p = 0.002), and were negatively correlated with thyroid stimulation blocking antibody activities (r = 0.58, p = 0.02). We have demonstrated that all cell-bound blocking type TRAb were converted to the stimulating type by anti-human IgG antibody and the degree of conversion was negatively correlated with the biological activity of blocking type TRAb.(ABSTRACT TRUNCATED AT 250 WORDS)

A strong association between thyrotropin receptor-blocking antibody-positive atrophic autoimmune thyroiditis and HLA-DR8 and HLA-DQB1*0302 in Koreans

We investigated whether the associations between HLA alleles of patients with autoimmune hypothyroidism varied according to the presence or absence of TSH receptor-blocking antibody (TRBab). We analyzed the HLA-A, -B, -C, and -DR antigens by serotyping and the DQA1 and DQB1 genes using both enzymatic DNA amplification and sequence-specific oligonucleotide hybridizations. The patient population consisted of 47 Korean patients with atrophic autoimmune thyroiditis and 62 patients with goitrous autoimmune thyroiditis. The antigen frequency of HLA-DR8 was significantly increased in 23 atrophic autoimmune thyroiditis patients that were positive for TSH binding inhibitor immunoglobulin (TBII) compared to 136 controls [52% vs. 16%; chi 2 = 13.1; Pc (corrected P value) = 0.003]. This relative risk was 5.7; the etiological fraction was 0.43. HLA-DQB1*0302 was also increased in patients with TBII-positive atrophic autoimmune thyroiditis (24% vs. 7%; chi 2 = 11.2; Pc = 0.012; relative risk = 4.4; etiological fraction = 0.19). No specific DR antigens or DQB1 alleles were increased in either TBII-negative atrophic autoimmune thyroiditis or goitrous autoimmune thyroiditis. A significant decrease in the frequency of HLA-DR6 antigen was observed in both TBII-positive atrophic autoimmune thyroiditis (0% vs. 32%; chi 2 = 8.4; Pc = 0.03) and goitrous autoimmune thyroiditis (0% vs. 32%; chi 2 = 23.2; Pc < 0.001) patients. The frequency of the HLA-Cw1 antigen was significantly increased in all patient groups. We conclude that TRBab-positive atrophic autoimmune thyroiditis is immunogenetically different from both goitrous autoimmune thyroiditis and TRBab-negative atrophic autoimmune thyroiditis. It is possible that HLA-DR8 and/or DQB1*0302 may be related to the susceptibility genes involved in the production of TRBab in Koreans.