牧野 真樹

Chronic kidney disease (CKD) and heart failure (HF) are the first and most frequent comorbidities associated with mortality risks in early-stage type 2 diabetes mellitus (T2DM). However, efficient screening and risk assessment strategies for identifying T2DM patients at high risk of developing CKD and/or HF (CKD/HF) remains to be established. This study aimed to generate a novel machine learning (ML) model to predict the risk of developing CKD/HF in early-stage T2DM patients. The models were derived from a retrospective cohort of 217,054 T2DM patients without a history of cardiovascular and renal diseases extracted from a Japanese claims database. Among algorithms used for the ML, extreme gradient boosting exhibited the best performance for CKD/HF diagnosis and hospitalization after internal validation and was further validated using another dataset including 16,822 patients. In the external validation, 5-years prediction area under the receiver operating characteristic curves for CKD/HF diagnosis and hospitalization were 0.718 and 0.837, respectively. In Kaplan-Meier curves analysis, patients predicted to be at high risk showed significant increase in CKD/HF diagnosis and hospitalization compared with those at low risk. Thus, the developed model predicted the risk of developing CKD/HF in T2DM patients with reasonable probability in the external validation cohort. Clinical approach identifying T2DM at high risk of developing CKD/HF using ML models may contribute to improved prognosis by promoting early diagnosis and intervention.

We propose mini-batch top-n k-medoids to sequential pattern mining to improve CGM interpretation. Mecical workers can treat specific patient groups better by understanding the time series variation of blood glucose results. For 10 years, continuous glucose monitoring (CGM) has provided time-series data of blood glucose thanks to the invention of devices with low measurement errors. We conducted two experiments. In the first experiment, we evaluated the proposed method with a manually created dataset and confirmed that the method provides more accurate patterns than other clustering methods. In the second experiment, we applied the proposed method to a CGM dataset consisting of real data from 163 patients. We created two labels based on blood glucose (BG) statistics and found patterns that correlated with a specific label in each case.

In this paper, we propose feature extraction method for prediction model for at the early stage of diabetic kidney disease (DKD) progression. DKD needs continuous treatment; however, a hospital visit interval of a patient at the early stage of DKD is normally from one month to three months, and this is not a short time period. Therefore it makes difficult to apply sophisticated approaches such as using convolutional neural networks because of the data limitation. The propose method uses with hierarchical clustering that can estimate a suitable interval for grouping inputted sequences. We evaluate the proposed method with a real-EMR dataset that consists of 30,810 patient records and conclude that the proposed method outperforms the baseline methods derived from related work.

OBJECTIVE: Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is an immune-mediated condition that can affect almost any organ. We investigated the association between IgG4-RD and the main characteristics of Graves' disease (GD) at the time of diagnosis. Additionally, we evaluated whether serum IgG4 levels change during treatment. DESIGN AND PATIENTS: Twenty-eight patients with newly diagnosed GD were enrolled into this longitudinal follow-up study. Serum IgG4 levels and thyroid function were measured in all the participants at the time of diagnosis. Further, the serum IgG4 levels of nine of 28 patients with untreated GD were measured after the achievement of euthyroid state (through the use of methimazole). RESULTS: Two (7.1%) of 28 patients with untreated GD had elevated serum IgG4 levels of >135 mg/dL. There was no significant difference in the average IgG4 levels before and after the achievement of euthyroid state (66.2±74.0 mg/dL vs. 50.5±47.3 mg/dL). In two patients, the elevated serum IgG4 levels returned to normal after treatment. However, one patient had an elevated serum IgG4 level of 136.6 mg/dL after treatment. CONCLUSIONS: This study showed that serum IgG4 levels varied with treatment in patients with GD, independent of thyroid function, suggesting that IgG4 might be indirectly related to GD.

AIMS: The aim of this study is to investigate the effects of a low-carbohydrate staple food (i.e., low-carbohydrate bread) on glucose and lipid metabolism and pancreatic and enteroendocrine hormone secretion in comparison with meals containing normal-carbohydrate bread, without consideration of the carbohydrate content of the side dishes. METHODS: T2DM patients (n = 41) were provided meals containing low-carbohydrate bread (LB) together with side dishes or normal-carbohydrate bread (NB) together with side dishes every other day as a breakfast. Blood glucose levels were evaluated by using a continuous glucose monitoring system; blood samples were collected before and 1 and 2 h after the breakfast. RESULTS: Postprandial blood glucose levels, plasma insulin, plasma glucose-dependent insulinotropic polypeptide (GIP) and plasma triglyceride were significantly lower and plasma glucagon levels were significantly higher in LB compared with those in NB. Plasma glucagon-like peptide-1 (GLP-1) levels did not differ in the LB and NB groups. CONCLUSIONS: These results indicate that changing only the carbohydrate content of the staple food has benefits on glucose and lipid metabolism in T2DM patients concomitant with the decrease of insulin and GIP secretion, which ameliorate body weight gain and insulin resistance.

Artificial intelligence (AI) is expected to support clinical judgement in medicine. We constructed a new predictive model for diabetic kidney diseases (DKD) using AI, processing natural language and longitudinal data with big data machine learning, based on the electronic medical records (EMR) of 64,059 diabetes patients. AI extracted raw features from the previous 6 months as the reference period and selected 24 factors to find time series patterns relating to 6-month DKD aggravation, using a convolutional autoencoder. AI constructed the predictive model with 3,073 features, including time series data using logistic regression analysis. AI could predict DKD aggravation with 71% accuracy. Furthermore, the group with DKD aggravation had a significantly higher incidence of hemodialysis than the non-aggravation group, over 10 years (N = 2,900). The new predictive model by AI could detect progression of DKD and may contribute to more effective and accurate intervention to reduce hemodialysis.

This paper proposes a method for modeling event sequences with ambiguous timestamps, a time-discounting convolution. Unlike in ordinary time series, time intervals are not constant, small time-shifts have no significant effect, and inputting timestamps or time durations into a model is not effective. The criteria that we require for the modeling are providing robustness against time-shifts or timestamps uncertainty as well as maintaining the essential capabilities of time-series models, i.e., forgetting meaningless past information and handling infinite sequences. The proposed method handles them with a convolutional mechanism across time with specific parameterizations, which efficiently represents the event dependencies in a time-shift invariant manner while discounting the effect of past events, and a dynamic pooling mechanism, which provides robustness against the uncertainty in timestamps and enhances the time-discounting capability by dynamically changing the pooling window size. In our learning algorithm, the decaying and dynamic pooling mechanisms play critical roles in handling infinite and variable length sequences. Numerical experiments on real-world event sequences with ambiguous timestamps and ordinary time series demonstrated the advantages of our method.

This paper describes a technology for predicting the aggravation of diabetic nephropathy from electronic health record (EHR). For the prediction, we used features extracted from event sequence of lab tests in EHR with a stacked convolutional autoencoder which can extract both local and global temporal information. The extracted features can be interpreted as similarities to a small number of typical sequences of lab tests, that may help us to understand the disease courses and to provide detailed health guidance. In our experiments on real-world EHRs, we confirmed that our approach performed better than baseline methods and that the extracted features were promising for understanding the disease.

<p>  A 34-year-old woman with type 1 diabetes on hemodialysis was admitted to our hospital for simultaneous pancreas kidney transplantation received from her father. She had suffered from type 1 diabetes mellitus since age 13, and had complained of serious atonic gastroenteropathy and orthostatic hypotension. After the transplantation, she became free from hemodialysis and insulin injection. At the same time, her gastrointestinal symptoms disappeared. However, she still had orthostatic hypotension, which was improved by taking fludrocortisone. Two months after the transplantation, orthostatic hypotension with marked polyuria became obvious. By hypertonic saline challenge test, she was diagnosed as partial central diabetes insipidus. Although treatment with desmopressin was necessary for 5 months, she became free from medication afterwards. Diabetes insipidus seems to be a rare but could be an important complication after simultaneous pancreas kidney transplantation and/or or kidney transplantation.</p>

Autoimmune thyroid diseases (AITDs), including Graves' diseases (GD) and Hashimoto's thyroiditis (HT), are the most common autoimmune diseases, and are mainly mediated by T cells that produce cytokines and chemokines in abnormal amounts. Few reports have described the circulating chemokines active in AITDs. Recently, we used a new multiplex immunobead assay to simultaneously measure cytokines and chemokines in small volume serum samples from patients with AITDs. We measured 23 selected serum chemokines in patients with GD (n=45) or HT (n=26), and healthy controls (n=9). GD patients were further classified as either untreated, intractable, or in remission, while HT patients were classified as either hypothyroid or euthyroid. Of the 23 serum chemokines assayed, only the serum level of IP-10 (CXCL10/interferon-γ-inducible protein 10) was elevated, depending on disease activity, in GD or HT compared with healthy controls. However, the serum level of IP-10 was also increased in both untreated GD patients and hypothyroid HT patients, suggesting that levels of this cytokine may not be affected by disease specificity. In conclusion, autoimmune inflammation in patients with AITD is closely related to the level of the serum chemokine, IP-10. Therefore, IP-10 might be a good biomarker for tissue inflammation in the thyroid, but not a useful biomarker for predicting disease specific activity, the progression of AITDs, or responsiveness to treatment because of its independence from thyroid function or disease specificity.

Background Despite recent progress of immunosuppressive therapy with newly developed agents, long-term pancreatic graft survival after pancreas transplantation still remains low. Therefore, precise assessment of β-cell function after pancreas transplantation is necessary. Methods Pancreatic β-cell secretory activity was measured by means of the peripheral plasma fasting serum C-peptide (CPR) response to 1 mg of glucagon intravenously in 23 patients after pancreas transplantation. The utility of ΔCPR after injection was compared with other indices that reflect insulin secretion. Results When we performed the test, 6 patients still needed insulin injection after the transplantation. Mean CPR before and after glucagon intravenously were 1.9 ± 0.98 ng/mL and 4.6 ± 2.29 ng/mL, respectively. Fasting serum CPR, secretory unit of islet in transplantation (SUIT) index, and ΔCPR after glucagon injection were significantly different between insulin users and nonusers. During follow-up (501 ± 228 days), 3 patients could stop using insulin, and their increase of CPR (1.8 ± 0.5 ng/mL) was significantly higher than that in continuous insulin users (0.3 ± 0.3 ng/mL). Conclusion Fasting CPR, SUIT index, and ΔCPR after glucagon injection could reflect β-cell function for post-pancreas transplant patients, and glucagon stimulation test could give us additional information to predict insulin-free treatment. © 2014 by Elsevier Inc. All rights reserved.

The 112/121 haplotype combination defined by the UCSNP-43, -19, and -63 alleles in the calpain-10 gene is associated with type 2 diabetes in Mexican Americans. To determine whether this genetic variation constitutes risk of type 2 diabetes in Japanese, we investigated its frequency in 177 patients with type 2 diabetes and 172 controls. Though this variation occurs in Japanese more frequently than in Mexican Americans, there is no significant difference in frequency between diabetic (29.9%) and control (31.9%) subjects. We also screened all exons and the putative promoter of the calpain-10 gene for mutations in 96 of the genotyped patients, resulting in the identification of 7 coding variants, including 3 missense mutations and 5 nucleotide alterations in the promoter. However, their frequencies all are similar in patients and controls, suggesting that these genetic variations are not a major factor in the occurrence of type 2 diabetes in Japanese, although they could yet. be associated with various phenotypes of the disease.

The possible role of abnormal T cell-dependent B-cell activation in Graves' disease was investigated by comparing lymphocyte subset distribution and the production of soluble CD8 (sCD8), sCD23, IL-10 and IL-12 by peripheral blood cells (PBMC) and thyroid-infiltrating lymphocytes (TL) in vitro. In TL, the percentage of CD8(+) cells was slightly higher and the sCD8 concentration was significantly higher than in PBMC. The ratio CD23(+) cells to CD20(+) cells (activated B/pan B cells) was increased in TL compared to PBMC from Graves' or normal controls, although the percentage of CD20(+) cells was decreased. Compared to PBMC in Graves' disease, the relative ratio of IL-10 to IL-12 release (IL-10/IL-12) by unstimulated TL was increased, despite a lack of significant difference between PBMC and TL in mean values for either IL-10 or IL-12 secretion. Incubating PBMC with a combination of anti-CD40 monoclonal antibodies and interleukin-4 (IL-4) resulted in B cell activation, reflected in an increase in the sCD23 level in both controls and Graves' patients, but especially prominent in the latter. Stimulation with anti-CD40 antibody and IL-4 also decreased the percentage of CD8+ cells in PBMC but not TL from both Graves' disease and normal controls, and the percentage of CD8(+) cells in TL was higher than PBMC after the stimulation. The sCD23 concentration in TL was decreased compared to PBMC both in patients with Graves' disease and normal controls. However, in contrast to the increased responses observed in Graves' PBMC or normal controls after stimulation, sCD23 levels remained the same in stimulated TL from Graves' patients. This combination of B cell stimulants increased production of IL-10 in PBMC but not in TL obtained from patients with Graves' disease, and the increased IL-10/IL-12 ratio declined to a value no different from that in PBMC group after stimulation. Thus, T cell-dependent B-cell activation via a CD40 pathway may cause a shift in the Th-1/Th-2 balance to Th-2 dominance in Graves' disease, while increased CD8(+) cells in TL may suppress sCD23 production and IL-10-producing Th2 cells. (C) 2002 Elsevier Science Ltd. All rights reserved.

The possible roles of CD8(+) cells in the abnormal T cell-dependent B-cell activation in Graves' disease were investigated by analysing lymphocyte subsets in peripheral blood mononuclear cells (PBMC) and their production of soluble factors and cytokines such as IL-10 in patients with Graves' disease, Hashimoto's thyroiditis and normal controls. The PBMC were separated into CD8(+) and CDS-depleted cells by magnetic separation columns, and cultured for 7 days with or without anti-CD40 monoclonal antibodies and IL-4. The culture supernatant was assayed for sCD23 and IL-10 using ETA, and the remaining cells were analysed by flow cytometry. Stimulation with anti-CD40 antibody together with IL-4 increased sCD23 levels and the number of CD23(+) cells. The latter was further augmented by depletion of CD8(+) cells. This combination of B cell stimulants increased production of IL-10 by PBMC from patients with Graves' disease. The CD40- and IL-4-activated production of IL-10 was decreased by CD8(+) cell depletion. In contrast, constitutive production of IL-10 was increased after CD8(+) cell depletion in a group of patients with low basal secretion levels (&lt;35 ng/ml). It was, however, decreased in a group with higher basal production levels, but such a relationship was not found in the normal control group. Thus, T cell-dependent B-cell activation via a CD40 pathway activates CD23(+) cells, leading to over-production of IL-10 and a shift of the Th1/Th2 balance to Th2 dominance, while CD8(+) cells may suppress this activation to counteract the Th2 deviation in Graves' disease.

A-33-year-old woman who suddenly developed excessive thirst on March 31, 2001, and was admitted on April 2, 2001, due to an impending abortion lost consciousness after the abortion and was transferred to our hospital. Her blood glucose was 789 mg/dl with severe metabolic acidosis, pH 7.006, and positive serum and urinary ketone bodies, consistent with diabetic ketoacidosis. Her HbA1C was close to normal (6.1%), while urinary C-peptide was very low (1.2 μg/day). Serum concentrations of amylase, lipase, and elastase 1 were elevated. The results of a glucagon loading test showed impaired insulin secretion. Diabetes-related autoantibodies including anti-GAD-antibody, anti-IA-2-antibody, and ICA were all negative. Her HLA type was A2, A 24 (9), B 61 (40), B 51 (5), DR 2, DR 8, DQ 1, and DQ 4. The onset of type 1 diabetes during pregnancy has mostly been reported during the 2nd and 3rd trimesters and is rare in early pregnancy. Fulminant type 1 diabetes has been proposed characterized by near-normal HbA1C despite diabetic ketoacidosis and rapid loss of insulin secretion. Here, we report the case of a pregnant woman who developed typical fulminant type 1 diabetes as early as 7 weeks into gestation.

Thyroid hormones affect reactions in almost all pathways of lipid metabolism. It has been reported that plasma free fatty acid (FFA) concentration in hypothyroidism is generally within the normal range. In this study, however, we show that plasma FFA concentration in some hypothyroid patients is higher than the normal range. Symptoms of thyroid dysfunction in these individuals were less severe than those of patients with lower plasma FFA concentrations. From these findings we hypothesized that the change in FFA concentration must correlate with thyroid function. Using an animal model, we then examined the effect of highly purified eicosapentaenoic acid ethyl ester (EPA-E), a n-3 polyunsaturated fatty acid derived from fish oil, on thyroid function in 1-methyl-2-imidazolethiol (MMI)-induced hypothyroid rats. Oral administration of EPA-E inhibited reduction of thyroid hormone levels and the change of thyroid follicles in MMI-induced hypothyroid rats. These findings suggest that FFA may affect thyroid functions and EPA-E may prevent MMI-induced hypothyroidism.

A high blood concentration of endothelin (ET)-1 may participate in the onset and progress of diabetic microangiopathy, resulting in neuropathy. We examined the therapeutic effects of prostaglandin E1 (PGE1), which possesses both a peripheral vasodilating action and inhibition of platelet aggregation, on diabetic microangiopathy. Increases in both skin temperature and peripheral never conduction velocity in diabetic patients were recorded four weeks after Lipo PGE1 administration. A quantitative decrease in urinary albumin concentration was also observed, suggesting its efficacy of action was on diabetic nephropathy. Lipo PGE1 administration reduced the elevated circulating plasma ET-1 levels in the diabetic patients. As an increase in ET-1 concentrations is thought to correlate with the onset and progress of diabetic microangiopathy, the reduction of plasma ET-1 concentration by Lipo PGE(1) administration may be one reason for the improvement in diabetic neuropathy and nephropathy. (C) 2001 Elsevier Science Inc. All rights reserved.

We have sequenced the insulin gene in 72 unrelated Japanese subjects (52 with type 2 diabetes mellitus and 20 with normal glucose tolerance). We identified 6 mutations and all were found at a low frequency (1% to 4%). Three mutations were new. These included a C-to-G substitution in the promoter region, a G-to-A substitution in codon-2 resulting in an Ala-to-Thr replacement in amino acid -2 of the signal peptide, and a G-to-A substitution in intron 2. We have no evidence that any of the mutations that we found are the cause of diabetes. Thus, mutations in the insulin gene do not appear to be an important genetic factor contributing to the development of diabetes in this population. Copyright (C) 2001 by W.B. Saunders Company.

Background. Recently, an endothelin (ET-1) with a potent vasoconstrictive activity and stimulative activity of vascular muscular cell growth was discovered and blood ET-1 levels were higher in diabetic patients than in healthy subjects, suggesting that high ET-1 levels assist development and progression of diabetic microangiography. Methods: We examined renal function, and serum and tissue ET-1 levels in streptozotocin (STZ)-induced diabetic rats treated with a prostaglandin (PG) I-2 derivative to investigate the effect of PGI(2) in diabetic vascular disturbance. Results: Renal weight, urinary albumin, urinary N-acetyl-beta,D-glucosaminidase (NAG) and serum ET-1 levels increased in STZ-induced diabetic rats, and a tendency to increase in renal tissue ET-1 levels was observed. Furthermore, electron-microscopic findings in the kidneys showed mesangial cell proliferation and mesangial matrix expansion which might be caused by diabetic nephropathy. The PGI(2) derivative reduced urinary albumin and NAG levels in STZ-induced rats. It was considered, therefore, that the PGI(2) derivative is effective in diabetic nephropathy. As the PGI(2) derivative also reduced renal tissue ET-1 levels, improvement of diabetic nephropathy partially was considered to result from the reduction of renal tissue ET-1 levels. Conclusion: In STZ-induced rats, increased serum ET-1 levels and a tendency to increase in renal tissue ET-1 levels were associated with increases in urinary albumin and NAG levels, and these levels were decreased by a PGI(2) derivative. These findings suggested that increased ET-1 concentrations assist development and progression of diabetic nephropathy, especially diabetic microangiopathy, and the PGI(2) derivative may be effective for inhibition of diabetic microangiopathy mediated by reduction of ET-1 concentrations. Introduction Copyright (C) 2002 S. Karger AG, Basel.

We investigated the effect of T cell-dependent B cell activation on the production of IL-10 and IL-12 by peripheral blood mononuclear cells (PBMCs) obtained from patients with Graves' disease vs Hashimoto's thyroiditis, type 1 diabetes or normal controls. Incubation of PBMCs, from each of the subject groups, with a combination of anti-CD40 monoclonal antibodies and interleukin 4 (IL-4)-activated B cells, as shown by an increased level of soluble CD23, There was also a notable increase in the number of CD23(+) cells in PBMCs from patients with Graves' disease as compared to the other subject groups. This combination of B cell stimulants increased production of IL-10 in PBMCs obtained from patients with Graves' disease relative to those patients with Hashimoto's thyroiditis, type 1 diabetes, or the control subjects. The production of IL-12 showed wide variation that depended on the basal IL-12 level. In subjects with a low basal IL-12 level there was a positive correlation between the production of IL-12 and that of IL-10 from PBMCs stimulated with anti-CD40 antibodies plus IL-4, On the contrary, in the patients with a high basal IL-12 level, no change or a decrease of IL-12 production was observed after the stimulation. Thus, T cell-dependent B cell activation via a CD40 pathway triggers the overproduction of IL-10 and overcome the effect of IL-12 to shift the Th-1/Th-2 balance to Th-2 dominance in patients with Graves' disease but not in Hashimoto's thyroiditis or type 1 diabetes. (C) 2000 Academic Press.

Free radicals, hydroxyperoxides and H2O2 are all known to damage cell components. This study was designed to compare the concentrations of hydroxyperoxide and free radical scavengers in the cardiac muscles of old rats in the hyper- or hypothyroid condition, to determine whether rates of peroxidation would differ with age, thyroid status, or both. Rats were rendered hyper- or hypothyroid by administration of L-thyroxine or methimazole for 4 weeks. Among the old rats, the lipid peroxide (LPO) concentrations, measured as thiobarbituric acid (TBA) reactants, were significantly greater in the hyperthyroid than in the euthyroid state and the LPO concentrations measured as TBA+Fe3+ reactants, which may he precursors of LPO, were significantly greater in the hyperthyroid state, whereas in young rats, the LPO concentrations measured by TEA or TBA+Fe3+ methods did not differ significantly in the hyperthyroid state. In the euthyroid state, the concentration of LPO measured as TBA+Fe3+ reactants was significantly reduced with age. Xanthine oxidase (XOD) activity also was markedly increased with age, being more pronounced in the hyperthyroid than in the euthyroid state. The Mn and Cu/Zn superoxide dismutase activities were greater in the hyperthyroid than in the euthyroid state. Glutathione peroxidase activity decreased with age in the euthyroid and, particularly, in the hyperthyroid state. Catalase activity was not affected in the old rats. Concentrations of alpha-tocopherol in the old rats were high in the hyperthyroid state and low in the hypothyroid state, whereas the levels of beta- and gamma-tocopherols in these rats were unchanged in both conditions as compared with the euthyroid state findings. Data suggest that the site of free radical generation differs in older rats, with additional shifts in the location of intracellular Lipid peroxidation being noted during hyperthyroidism. Thus, as rats age, the reduction of the free radical scavenger system and the increase in LPO and XOD activities might induce myocardial dysfunction.

A 58-year-old woman was diagnosed to have pseudohypoparathyroidism (PHP) type II because of the absence of an Increase of urinary phosphate secretion, despite a marked increase in urinary cAMP excretion on the Ellsworth-Howard test. We treated the patient with a cyclic-nucleotide phosphodiesterase inhibitor, theophylline, resulting in increased urinary phosphate and cAMP excretions. Dibutyl cAMP administration induced the increase in the urinary phosphate excretion. In this case, the unresponsiveness of the urinary phosphate secretion to cAMP was recovered by a high dose of cAMP or long-term administration of a phosphodiesterase inhibitor. These data imply that cAMP responsiveness to renal tubular phosphate reabsorption should be more strictly elucidated in the patient with PHP type II.

The deterioration of glucose metabolism frequently observed in hyperthyroidism may be due in part to increased gluconeogenesis in the liver and glucose efflux through hepatocyte plasma membranes. Glucose transporter 2 (GLUT 2), a facilitative glucose transporter localized to the liver and pancreas, may play a role in this distorted glucose metabolism. We examined changes in the levels of GLUT 2 in livers from rats with L-thyroxine-induced hyperthyroidism or methimazole-induced hypothyroidism by using Western blotting to detect GLUT 2. An oral glucose tolerance test revealed an oxyhyperglycemic curve (impaired glucose tolerance) in hyperthyroid rats (n=7) and a flattened curve in hypothyroid rats (n=7). GLUT 2 levels in hepatocyte plasma membranes were significantly increased in hyperthyroid rats and were not decreased in hypothyroid rats compared with euthyroid rats. The same results were obtained with a densitometric assay. These findings suggest that changes in the liver GLUT 2 concentration may contribute to abnormal glucose metabolism in thyroid disorders.

Sorbitol accumulation plays an important role in diabetic complications involving the kidney, nerves, retina, lens and cardiac muscle. To investigate the influence of thyroid hormone on the sorbitol pathway, we studied the effects of thyroid hormone on polyol metabolism in normal and diabetic rats. Rats were divided into three groups: controls, streptozotocin (STZ)-induced diabetic euthyroid rats (DM) and STZ-induced diabetic hyperthyroid (thyroxine-injected) rats (DM+HT). The sorbitol (Sor) concentrations in the kidney, liver and sciatic nerve (2.53 +/- 0.74, 0.97 +/- 0.16 and 24.0 +/- 5.1 nmol/mg protein, respectively) of the DM rats were significantly higher than those (1.48 +/- 0.31, 0.58 +/- 0.13 and 3.1 +/- 0.6 nmol/mg protein) of the control rats. The Sor concentrations in the kidney and sciatic nerve of the DM+HT rats (1.26 +/- 0.29 and 9.40 +/- 1.2 nmol/mg protein) were significantly lower than those in the DM rats. These values were reduced in the liver, unchanged in the kidney, and increased in the sciatic nerve from the hyperthyroid rats without diabetes. Thyroid hormone reduced the aldose reductase (AR) activities in the kidney, liver and sciatic nerve of the DM rats, and similarly reduced AR in the kidney and liver, but not in the sciatic nerve, of the non-diabetic rats. The sorbitol dehydrogenase (SDH) activities were decreased by thyroid hormone in the kidney and liver but not the sciatic nerve of DM rats. In the non-diabetic rats, this enzyme activity was decreased in liver, but not in kidney or sciatic nerve. A positive correlation between the Sor concentration and AR activity was observed in the kidney and liver but not in the sciatic nerve from control, DM and DM+HT rats. A negative correlation was observed between the Sor concentration and SDH activities in the same organs. These data suggest that thyroid hormone affects the sorbitol pathway, but the detailed mechanism whereby this hormone reduces the sorbitol content (especially in diabetic rats) remains to be clarified. (C) 1998 Published by Elsevier Science B.V. All rights reserved.

Cu,Zn-superoxide dismutase(SOD) activity in erythrocytes is affected by various diseases, including diabetes mellitus (DM). We investigated changes in the Cu,Zn-SOD activity compared to changes in the Cu,Zn-SOD concentration in erythrocytes obtained from patients with Type 2 (non-insulin-dependent) diabetes mellitus. Cu,Zn-SOD activity in erythrocytes was significantly lower in Type 2 DM patients than in healthy non-diabetic subjects. The activity correlated negatively with HbA(1c), but not with other indicators of metabolic control, such as fasting blood glucose or plasma cholesterol or triglyceride. However, there was no statistically significant difference in erythrocyte concentration of Cu,Zn-SOD between diabetic and control samples. Concentration did not correlate with enzymatic activity or HbA(1c). These findings indicate that the inactivation of Cu,Zn-SOD activity in erythrocytes of Type 2 DM patients by hyperglycaemia may be slow, because there is a negative correlation between the enzyme activities and HbA(1c) levels, but not fasting blood glucose levels. This is consistent with glycosylation of the active site of Cu,Zn-SOD, without any effect of hyperglycaemia on the concentration of Cu,Zn-SOD. (C) 1998 John Wiley & Sons, Ltd.

We investigated the effect of T cell-dependent B cell activation on the surface expression and release of the soluble forms of CD8 and CD23 by peripheral blood mononuclear cells (PBMC) obtained from patients with GD, versus patients with Hashimoto's thyroiditis, and normal controls. Incubating the PBMC with anti-CD40 MoAbs and IL-4 increased the soluble CD23 levels in cells from all three groups. An increase in the number of CD23(+) cells was observed in the PBMC from the patients with GD, but not in PBMC from Hashimoto's thyroiditis or controls. Less soluble CD8 was released from anti-CD40 antibody and IL-4-stimulated PBMC obtained from patients with GD relative to those from the controls. In addition, the number of CD8(+) cells was significantly reduced in stimulated PBMC from the GD patients relative to those from controls. Incubation of PBMC with anti-CD40 antibody plus IL-4 did not affect the proportions of CD4(+), CD20(+), Fas(+)CD4(+), and Fas(+)CD8(+) cells. The addition of T-3 to cultured PBMC from controls did not reproduce the changes in CD23(+) and CD8(+) cells noted in the samples from GD patients. Thus, T cell-dependent B cell activation, mediated by a CD40 pathway, may reduce the number of CD8(+) cells, causing exacerbation of GD.

To clarify the different roles of free radical scavenging systems in various thyroid disorders, we measured the levels of alpha-, beta-, and gamma-tocopherols and coenzyme Q in the thyroid tissues of patients with thyroid tumors and Graves' disease using high-performance liquid chromatography. The levels of alpha-tocopherols and gamma-tocopherols in the thyroid tissue of patients with papillary carcinoma and the level of gamma-tocopherol in the thyroid tissue of patients with malignant lymphoma were elevated compared with those in normal thyroid tissues. The level of coenzyme Q was reduced in the thyroid tissue of patients with Graves' disease and follicular and papillary thyroid carcinomas. These findings imply that vitamin E and coenzyme Q as scavengers play some role in thyroid follicular cell hyperfunction or dysfunction.