An extremely energetic cosmic ray observed by a surface detector array

Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-energy events thought to come from extragalactic sources. Their arrival is infrequent, so detection requires instruments with large collecting areas. In this work, we report the detection of an extremely energetic particle recorded by the surface detector array of the Telescope Array experiment. We calculate the particle's energy as [Formula: see text] (~40 joules). Its arrival direction points back to a void in the large-scale structure of the Universe. Possible explanations include a large deflection by the foreground magnetic field, an unidentified source in the local extragalactic neighborhood, or an incomplete knowledge of particle physics.

Immunohistochemical detection of nm23-H1/NDP kinase in childhood thyroid carcinoma

Childhood thyroid cancer is known to be aggressive. High incidence of lymph node and distant metastasis are characteristic features of these cases. In adult, reduced expression of nm23-H1/nucleoside diphosphate (NDP) kinase has been correlated with cancer invasion and metastasis in some tumor types. Therefore, we examined the expression of nm23-H1 gene product in childhood thyroid carcinomas in Japan. 27 primary thyroid carcinomas and 8 metastatic lymph nodes were analyzed by immunohistochemistry using monoclonal antibody H1-229. 21 out of 23 cases (91%) of papillary carcinomas were positively immunostained, whereas none of the 4 follicular carcinomas showed any immunoreactivity. No correlation was found between the nm23-H1/NDP kinase antigen expression and nodal involvement or distant metastasis in primary tumors. However, only 50% (4 out of 8) of metastatic lymph nodes from papillary carcinoma were positively stained, demonstrating a significant decrease comparing to those of primary sites. These data indicate that the expression of nm23-H1/NDP kinase cannot predict tumor metastatic potential in childhood thyroid cancer.

Antibodies to GAD in Japanese patients classified as Type 2 diabetes at diagnosis. High titre of GAD Ab is a predictive marker for early insulin treatment--report of west Japan (Kyushu, Yamaguchi, Osaka) study for GAD Ab(+) diabetes

AIM

We evaluated the prevalence of GAD Ab in Japanese Type 2 diabetic patients treated with oral hypoglycaemic agents (OHA) and/or diet and followed GAD Ab(+) patients to assess the usefulness of GAD Ab as a marker for future insulin treatment prospectively.

METHODS

A total of 2658 Japanese Type 2 diabetic patients treated by OHA and/or diet were randomly selected between April 1996 and December 1998. The clinical characteristics at entry were assessed and patients were followed for 1-3 years.

RESULTS

The overall prevalence of GAD Ab among Type 2 diabetic patients was 2.0%. Forty-five had a history of diabetes of < or = 5 years (short history) while those with duration > 5 years (long history) totalled nine. Among them, 47% of patients with a short history did not require insulin in the follow-up period. However, none of those with a long history required insulin treatment within 2 years. Comparison of patients based on GAD titre in those with short history showed that 33% of patients in the high-titre group (> or = 20 U) required no insulin treatment in the first year of follow-up. In contrast, this proportion was 80% in the first and 67% in the second year in the low-titre group (< 20 U).

CONCLUSIONS

The prevalence of GAD Ab in Japanese patients with a short and long history of diabetes was 2.8% and 0.9%, respectively. The presence of GAD Ab in Japanese Type 2 diabetic patients with a short history of diabetes is a marker for early insulin treatment.

15 years after Chernobyl: new evidence of thyroid cancer

The Chernobyl nuclear power plant accident happened on April 26, 1986. We investigated the cause of the striking increase in frequency of thyroid cancer in children who lived within a 150 km radius of Chernobyl and who were born before and after the accident. No thyroid cancer was seen in 9472 children born in 1987-89, whereas one and 31 thyroid cancers were recorded in 2409 children born April 27, 1986, to Dec 31, 1986, and 9720 born Jan 1, 1983, to April 26, 1986, respectively. Short-lived radioactive fallout caused by the Chernobyl accident probably induced thyroid cancer in children living near Chernobyl.

[Ocular complications in patients infected with human immunodeficiency virus seen at the Acquired Immunodeficiency Syndrome Clinical Center]

PURPOSE

To examine the ocular complications in patients infected with human immunodeficiency virus(HIV) in Japan.

METHODS

The medical records of 322 patients seen at the acquired immunodeficiency syndrome(AIDS) Clinical Center from July 1, 1997 through December 31, 1998 were reviewed, and the HIV-associated ocular complications were correlated with serum CD 4+ T-lymphocyte counts.

RESULTS

Ocular complications were found in 51 patients: 35 cases with retinal microvasculopathy, 17 cases with cytomegalovirus retinitis(9 quiescent, 6 active, and 2 recurrent), and 1 case each with tuberculous uveitis, phthisis bulbi after necrotizing herpetic retinopathy, conjunctival Kaposi's sarcoma, papilledema, divergence palsy, hemianopia, and abducens palsy. Retinal microvasculopathy was present in patients with CD 4+ T-lymphocyte counts above 500/mm3, but was more common in patients with cell counts below 200/mm3. Among 6 patients with active cytomegalovirus retinitis, 5 patients had a CD 4+ T-lymphocyte count below 50/mm3 at the onset of retinitis, while one patient developed retinitis after the cell count increased to over 200/mm3 with highly active antiretroviral therapy.

CONCLUSION

Cytomegalovirus retinopathy may occur in patients with a CD 4+ T-lymphocyte count of more than 200/mm3.

Hypothalamic-pituitary-thyroidal dysfunctions in anorexia nervosa

There are clinical similarities between anorexia nervosa and hypothyroidism. Circulating levels of T4 and particularly T3 have been reported to be low in this eating disorder. Previous reports have, however, shown normal basal levels of serum TSH with normal or delayed responses to TRH. To assess thyroid function and the hypothalamic-pituitary axis in 21 women with anorexia nervosa, serum levels of free and total thyroid hormones, binding proteins, and TSH employing an extremely sensitive assay (detection limit = 0.02 microU/ml) were measured. Serum T4, free T4, T3, free T3, TSH, TBG and TBPA concentrations were significantly lower and rT3 levels were significantly higher in anorexia nervosa patients than in normal controls. A delayed TSH response to TRH was noted in 66% of patients, hyporesponsiveness was seen in another 24%, and a normal response in only 10%. In 10 anorexia nervosa patients studied after weight gain, T4, T3, free T3, TSH, TBG and TBPA were significantly increased, and rT3 was significantly decreased. No change in mean free T4 levels with weight gain was noted. Other parameters of hypothalamic dysfunction in anorexia nervosa have been reported and the present data suggest that apparent hypothalamic hypothyroidism occurs perhaps as an adaptation to prolonged starvation.

Autoantibodies to multiple islet autoantigens in patients with abrupt onset type 1 diabetes and diabetes diagnosed with urinary glucose screening

It has been reported that there is a heterogeneity in the clinical course of Japanese patients with type 1 diabetes. To elucidate the associations of expression of autoantibodies to multiple islet antigens with age of onset and mode of diagnosis of diabetes in Japanese patients with type 1 diabetes, autoantibodies against the protein tyrosine phosphatase-like molecules ICA512 (IA-2) and phogrin (IA-2beta) (ICA512/phogrin-A), GAD (GADA), insulin (IAA), and islet cell cytoplasm (ICA) were determined in sera from 73 Japanese patients with type 1 diabetes obtained within 14 days of diagnosis. Patients were divided into groups based on the age of onset (</=10 years, n=24 and >10 years, n=49) or the mode of onset (abrupt onset, n=59 and urinary screening identified, n=14). Of 73 new-onset patients with type 1 diabetes, 43 (59%) and 32 (44%) had ICA512A and phogrin-A levels exceeding the 99th percentile of 184 normal control subjects, respectively. Forty-five patients (62%) were positive for either ICA512A or phogrin-A. The frequencies for other autoantibodies were 71% for GADA, 48% for IAA, and 62% for ICA. The frequency of ICA512/phogrin-A was significantly higher in patients with an age of onset less than 10 years (83%) than in patients aged >10 years (51%, P<0.01). The positivity of ICA512/phogrin-A was less in patients whose diabetes was diagnosed by the urine glucose screening test (21%, P<0.001) than in abrupt onset patients (71%). Combined analysis (>/=1 antibody) of GADA, IAA, and ICA512/phogrin-A detected 88% of abrupt onset and 93% of screening-positive patients vs. 70% and 29%, respectively, for ICA (P<0.0005). These results indicate that the expression of ICA512/phogrin-A and cytoplasmic ICA is less in patients identified by urinary glucose testing but indicate that with combined autoantibody testing 90% of patients can be identified independent of the mode of diagnosis.

Significance of glutathione-dependent antioxidant system in diabetes-induced embryonic malformations

Hyperglycemia-induced embryonic malformations may be due to an increase in radical formation and depletion of intracellular glutathione (GSH) in embryonic tissues. In the past, we have investigated the role of the glutathione-dependent antioxidant system and GSH on diabetes-related embryonic malformations. Embryos from streptozotocin-induced diabetic rats on gestational day 11 showed a significantly higher frequency of embryonic malformations (neural lesions 21.5 vs. 2.8%, P<0.001; nonneural lesions 47.4 vs. 6.4%, P<0.001) and growth retardation than those of normal mothers. The formation of intracellular reactive oxygen species (ROS), estimated by flow cytometry, was increased in isolated embryonic cells of diabetic rats on gestational day 11. The concentration of intracellular GSH in embryonic tissues of diabetic pregnant rats on day 11 was significantly lower than that of normal rats. The activity of y-glutamylcysteine synthetase (gamma-GCS), the rate-limiting GSH synthesizing enzyme, in embryos of diabetic rats was significantly low, associated with reduced expression of gamma-GCS mRNA. Administration of buthionine sulfoxamine (BSO), a specific inhibitor of gamma-GCS, to diabetic rats during the period of maximal teratogenic susceptibility (days 6-11 of gestation) reduced GSH by 46.7% and increased the frequency of neural lesions (62.1 vs. 21.5%, P<0.01) and nonneural lesions (79.3 vs. 47.4%, P<0.01). Administration of GSH ester to diabetic rats restored GSH concentration in the embryos and reduced the formation of ROS, leading to normalization of neural lesions (1.9 vs. 21.5%) and improvement in nonneural lesions (26.7 vs. 47.4%) and growth retardation. Administration of insulin in another group of pregnant rats during the same period resulted in complete normalization of neural lesions (4.3 vs. 21.5%), nonneural lesions (4.3 vs. 47.4%), and growth retardation with the restoration of GSH contents. Our results indicate that GSH depletion and impaired responsiveness of GSH-synthesizing enzyme to oxidative stress during organogenesis may have important roles in the development of embryonic malformations in diabetes.

Specificity of omega-conotoxin MVIIC-binding and -blocking calcium channel antibodies in Lambert-Eaton myasthenic syndrome

An immunoprecipitation assay was used to measure omega-conotoxin MVIIC (P/Q-type) binding and blocking calcium channel antibodies in 67 patients with Lambert-Eaton myasthenic syndrome (LEMS) and in a large control population. We first showed the presence of omega-conotoxin MVIIC-blocking antibody in LEMS patients. Binding antibodies were detected in 55 of 67 (82.1%) LEMS patients and in 2 of 296 (0.7%) controls. In contrast, blocking antibodies were positive in 14 of 67 (20.9%) LEMS patients and 8 of 171 (4.7%) controls. No LEMS patient had negative binding antibodies and positive blocking antibodies. The immunoprecipitation assay detected no antibodies against the whole P/Q-type calcium channel in either the paraneoplastic cerebellar degeneration or the amyotrophic lateral sclerosis sera. Neither the omega-conotoxin MVIIC-binding nor the -blocking calcium channel antibodies were correlated with clinical severity across the individuals, but longitudinal studies of some LEMS patients showed an inverse relation between binding antibody titre and disease severity. We concluded that the 125I-omega-conotoxin MVIIC assay for anti-P/Q-type voltage-gated calcium channel antibodies is highly specific for LEMS and that this sensitive binding antibody assay could be more valuable than the blocking antibody assay in the diagnosis of LEMS.

Expression and function of Fas and Fas ligand on peripheral blood lymphocytes in normal subjects

We investigated the expression and function of Fas and Fas ligand (FasL) on peripheral blood lymphocytes (PBLs). The cells were stimulated with various cytokines or 12-0-tetradecanoyl phorbol 13-acetate (PMA) plus ionomycin. About 30% of unstimulated PBLs expressed Fas, and the expression was augmented by interleukin-1beta (IL-1beta), IL-2, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), or PMA plus ionomycin. Although only minimal FasL expression was detected on unstimulated PBLs, FasL expression was markedly induced by IL-2 or PMA plus ionomycin, suggesting that Fas and FasL were both expressed on IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs. Although IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs were positive for both Fas and FasL, no significant increase in apoptosis was demonstrated in these activated PBLs. In addition, treatment of PBLs with IL-2 or PMA plus ionomycin did not change anti-Fas-induced apoptosis, although these activated PBLs expressed Fas strongly when compared with unstimulated PBLs. Only IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs killed Fas+ target cells efficiently via the interaction of Fas on target cells with FasL of PBLs. Bcl-2 was constitutively expressed on unstimulated PBLs, but its expression was significantly augmented by IL-2 or PMA plus ionomycin. The expression of Bax was clearly induced only on IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs and that of other Bcl-2 family proteins such as Bcl-x and Bad could not be detected on human PBLs, including IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs. Our results suggest that PBLs activated by IL-2 or PMA plus ionomycin express both Fas and FasL and that they kill Fas+ target cells by using FasL on the surface. The resistance of these activated PBLs to Fas-mediated apoptosis may be due to the augmented Bcl-2 expression or the presence of Bcl-2:Bax heterodimers on these cells.

Role of apoptosis of thyrocytes in a rat model of goiter. A possible involvement of Fas system

Apoptosis, a physiological process of cell death, may modulate the mass of the thyroid gland. We investigated the role of apoptosis and the possible involvement of Fas/Fas ligand (FasL) system in apoptosis during goiter formation and involution in a rat model of goiter. Rats were fed a low iodine diet and a goitrogen, 6-propyl-2-thiouracil, to induce goiter. Rats with goiter were then fed a high iodine diet to study the phase of involution. We examined the presence of apoptosis by electron microscopy (EM) and terminal deoxy-UTP nick end labeling (TUNEL). We also investigated the association between Fas and FasL expression and thyrocyte apoptosis using immunohistochemistry and Western blotting. To evaluate the proliferation of thyrocytes, proliferating cell nuclear antigen was examined immunohistochemically. The number of apoptotic cells increased during goiter formation and the early stage of involution, which were also associated with increased number of Fas-positive thyrocytes, and some of these cells contained TUNEL-positive nuclei. However, the expression of FasL was almost constant throughout the experiment. Proliferating cell nuclear antigen/TUNEL ratio markedly increased during goiter formation but decreased particularly during the late stage of goiter involution. Our results indicate that apoptosis of thyrocytes is a main factor of cell loss during goiter formation and involution and suggest that the Fas/FasL system is involved in the induction of apoptosis of these cells. Moreover, the delicate balance between apoptosis and cell proliferation may play an important role in the control of thyroid gland mass.

ret rearrangements in Japanese pediatric and adult papillary thyroid cancers

Oncogenic rearrangements of the ret proto-oncogene (ret/PTC) are found uniquely in papillary thyroid carcinomas. The prevalence of ret/PTC in these tumors varies widely, from 0% to 87%, among patient series from different geographical regions. The differences in the prevalence of ret rearrangement have been ascribed to age, genetic, and/or environmental factors. The very high prevalence of ret/PTC in tumors arising in children after the Chernobyl nuclear accident has generated speculation that this oncogene may be an indicator of overt or inadvertent radiation exposure. In Japan, the prevalence of ret activation is reportedly quite low (0% to 9%). Here we examined the frequency of ret rearrangements in papillary carcinomas from Japanese adults and children by means of reverse transcription polymerase chain reaction (RT-PCR) followed by Southern hybridization. Ret rearrangements were detected in 4 of 11 (36%) tumors from the adult population, and in 3 of 10 (30%) pediatric tumors. One child with a solid variant papillary carcinoma had a ret-PTC3 rearrangement, further supporting the association between the solid variant histotype and this particular rearrangement of ret. The present data do not support a major geographic difference in the prevalence of ret/PTC rearrangements in papillary carcinomas between Japan, the United States, and Italy.

[An autopsy case of rheumatoid arthritis accompanied with acute exacerbation of interstitial pneumonia]

An autopsy case of rheumatoid arthritis (RA) with acute exacerbation of interstitial pneumonia is reported. A 57-year-old woman with longstanding RA was admitted to our hospital because of progressive dyspnea. On chest roentogenogram, diffuse interstitial shadow was confirmed in both lungs. Chest computed tomography (CT) showed diffuse lesion of elevated density of CT level in both lung. She was diagnosed as an acute exacerbation of interstitial pneumonia, and treated by methylpredonisolone pulse therapy (1,000 mg/day). Although cyclosporin A (2 mg/kg/day) was combined to steroid therapy, she was died of progressive respiratory failure. The histological findings of the lung showed extensive fibrosis with alveolar damage associated with hyaline membranes, edema and hemorrhage in alveolar space.

Regulation of alkaline phosphatase gene expression in human hepatoma cells by bile acids

Bile acid-dependent secretion and the translationally regulated synthesis of alkaline phosphatase (ALP) in rat liver cell culture and by bile duct ligation has already been demonstrated. With the advent of ALP cDNA cloned sequences, the mechanism of the effect of bile acids on ALP activity and the expression of the ALP gene in different hepatoma cells was investigated. The HuH7 and HepG2 cells were treated with taurine-conjugated cholic acid (CA), chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA) at 0-1 mmol/L and the numbers of viable cells were counted at 24, 48 and 72 h after treatment. A [3H]-thymidine incorporation study was performed with different bile acids at a concentration of 1 mmol/L for 48 h. The cellular activity of ALP in HuH7 and HepG2 cells by bile acids was measured by a substrate-specific enzymatic assay. To elucidate the effects of bile acids on ALP gene expression, a northern blotting experiment using hybridization with mouse placental ALP cDNA was performed. Cellular ALP activity was time- and dose-dependently increased in both HuH7 and HepG2 cells treated by CA and CDCA; however, no change in ALP activity was observed following treatment with UDCA compared with controls. Induction of ALP activity was dominant in HepG2 cells and independent of cell growth and proliferation. The addition of UDCA synergistically reduced the increased activity of ALP produced by CA and CDCA in both HuH7 and HepG2 cells. By northern blot analysis, the level of ALP mRNA was elevated by CA and CDCA; however, levels of ALP mRNA were suppressed by UDCA. In conclusion, CA and CDCA cause up-regulation of ALP mRNA and UDCA leads to down-regulation of ALP mRNA by its interaction with either CA or CDCA. We assume that increased ALP synthesis in hepatoma cells after bile acid treatment results from an enhanced rate of transcription rather than translation of mRNA.

Apoptosis induction in synovial fibroblasts by ceramide: in vitro and in vivo effects

Several lipid second messengers are important mediators of extracellular signals. Among them ceramide, which is formed by cell membrane sphingomyelin, influences the apoptotic signal pathway through Fas antigen. We examined the apoptotic effect of cell-permeable C2-ceramide on rheumatoid synovial fibroblasts in vitro and in vivo. Exposure of cultured human rheumatoid synovial fibroblasts to C2-ceramide for 24 hours produced internucleosomal DNA fragmentation and morphologic changes characteristic of apoptosis. This C2-ceramide-mediated apoptosis was dose dependent as confirmed by analysis of cytosolic oligonucleosome-bound DNA of treated synovial fibroblasts. We also demonstrated that intra-articular administration of C2-ceramide into Fas-deficient MRL lpr/lpr mice produced a profound reduction of synovial hyperplasia within 24 hours. In situ nick end labeling analysis confirmed the induction of apoptosis in synovial lining cells. Our results indicate that C2-ceramide may function as a potent inducer of apoptosis in the synovium and suggest that pharmacologically-induced apoptosis may be useful as a new therapeutic modality for rheumatoid arthritis.

Preoperative treatment of growth hormone-producing pituitary adenoma with continuous subcutaneous infusion of octreotide

Preoperative therapy with octreotide, a long-acting somatostatin analog, suppresses GH hypersecretion, shrinks GH-producing tumors and leads to an improvement in subsequent surgical remission in acromegalic patients. A continuous infusion of octreotide has demonstrated more persistent suppression of GH secretion than intermittent injections, and only a few studies were reported on the effect of the tumor shrinkage with a continuous infusion of a small dose of octreotide. We therefore investigated the preoperative effects of small doses of octreotide (120-240 micrograms/day) administered continuously (with a subcutaneous infusion pump) over a short period (2 or 4 weeks) in nine untreated acromegalic patients. Octreotide therapy resulted in suppression of serum GH and IGF-1 concentrations in 8 out of 9 patients and reduction in pituitary tumor size measured by MRI in all patients (by 7.9 to 38.5%). In particular, considerable reduction in tumor size (more than 20%) occurred in 6 of 9 patients. In three patients assessed serially throughout the preoperative period, reduction in tumor size was noted within only one week after the start of octreotide therapy and reduction rate more than 20% was obtained within the first two weeks. In one patient, suprasellar tumor expansion totally disappeared after such therapy. Our results indicate that short-term continuous subcutaneous infusion of a small dose of octreotide results in not only inhibition of GH hypersecretion but also shrinkage of tumor size prior to surgery.

Inhibitory effect of glucocorticoid for osteoblast apoptosis induced by activated peripheral blood mononuclear cells

Recent studies suggest a protective effect of glucocorticoid against progression of bone erosion and periarticular osteoporosis in patients with rheumatoid arthritis (RA), although this steroid hormone itself is believed to increase bone loss. To understand the antagonistic effect of glucocorticoid for osteopenic process in RA patients, we examined the effect of dexamethasone on Fas-mediated apoptosis of cultured human osteoblasts induced by either anti-Fas IgM or activated peripheral blood mononuclear cells (PBMC). Human osteoblastic cell line MG63 and primary osteoblast-like cells obtained from biopsy specimens were used in this study. PBMC isolated from healthy donors were cultured with or without recombinant interleukin-2 (rIL-2) followed by 12-O-tetradecanoyl-phorbol 13-acetate (PMA) with ionomycin in the presence or absence of dexamethasone. Fas was functionally expressed on MG63 and primary osteoblast-like cells, and treatment of these cells with dexamethasone affected neither Fas expression nor anti-Fas IgM-induced apoptosis. Activated PBMC expressing membrane-type Fas ligand (mFasL) efficiently killed both MG63 and primary osteoblasts-like cells, and the addition of human Fas chimeric protein (hFas-Fc) significantly diminished the cytotoxicity, indicating that interactions between mFasL of activated PBMC and Fas on human osteoblasts induce apoptosis of the latter. Although dexamethasone did not affect apoptosis of MG63 and primary osteoblast-like cells induced by anti-Fas IgM, treatment of activated PBMC with dexamethasone markedly inhibited both mFasL expression and cytotoxicity of these cells against human osteoblasts, suggesting that dexamethasone preferentially acts not on osteoblasts but PBMC. Cultured supernatants from activated PBMC induced apoptosis of human osteoblasts and the addition of hFas-Fc also inhibited the cytotoxicity of the supernatants. In addition, soluble form FasL (sFasL) was detected in the supernatants of activated PBMC. Furthermore, both the cytotoxicity and sFasL concentration of cultured supernatants of activated PBMC incubated with dexamethasone was significantly lower than that in the absence of dexamethasone. Our data suggest that glucocorticoid suppresses the apoptotic process of osteoblasts by inhibiting the expression of both mFasL and sFasL derived from activated PBMC, mediating a protective effect against periarticular bone loss and bone erosion in inflammatory arthritis such as RA.

Childhood thyroid cancer: comparison of Japan and Belarus

The high incidence of childhood thyroid cancer in Belarus is suspected to be due to radiation exposure after the Chernobyl reactor accident. To clarify the clinical and histological characteristics of childhood thyroid cancer in Belarus, we therefore compared these patients to a radiation non-exposed control series in Japan. In Belarus, 26 thyroid cancers in subjects aged 15 or younger were diagnosed among 25,000 screened between 1991 and 1995 by Chernobyl-Sasakawa Health and Medical Cooperation Project. The clinical and morphologic features of these 26 cases were compared to 37 childhood thyroid cancers in Japan diagnosed between 1962 and 1995. The age distribution at operation in Belarus showed a peak at 10 years old, with a subsequent fall in numbers. In contrast, the age distribution at operation in Japan showed a smooth increase between the ages of 8 and 14. The mean tumor diameter was smaller in Belarus than that in Japan (1.4 +/- 0.7 vs. 4.1 +/- 1.7 cm, P < 0.001). The sex ratio, regional lymph node metastasis, extension to surrounding tissues or lung metastasis did not differ significantly. Histologically, all cases in Belarus were papillary and in Japan 33 cases were papillary and 4 cases were follicular carcinomas. Among papillary carcinomas, the frequency of a solid growth pattern, a criteria for classifying a tumor as poorly differentiated, was higher in Belarus than that in Japan (61.5 vs. 18.2%, P < 0.001). The difference between the features of childhood thyroid cancer in Japan and Belarus may be due to the difference in the process of carcinogenesis, but more direct evidence and further analysis by molecular epidemiology are needed in Belarussian cases.

Onset age-dependent variations of three islet specific autoantibodies in Japanese IDDM patients

The age related incidence rate of insulin-dependent diabetes mellitus shows a bimodal distribution, not only in Caucasians but also in Japanese. To evaluate the onset age-related autoimmune profile at presentation in insulin-dependent diabetes mellitus (IDDM), glutamic acid decarboxylase (GAD) autoantibody, islet cell antibody (ICA), and insulin autoantibody (IAA) were measured in 137 newly diagnosed Japanese IDDM patients with onset ages between 0-29 years. The prevalence of GAD autoantibody was significantly increased from the lowest (32%) in the 0-5 years onset age group to 75% in the 13-19 years onset age group (P < 0.05), whereas the IAA prevalence significantly decreased from the peak (48%) in the 6-12 years onset age group to 10% in the 20-29 years onset age group (P < 0.05). The ICA prevalence was increased from the lowest (32%) in the 0-5 years onset age group to the highest (53%) in the 20-29 years onset age group similar to that for the GAD autoantibody. Such results demonstrate that there was age-related autoimmune characteristics at presentation of IDDM in Japanese as well as in Caucasians.

Elevated serum levels of soluble E- and L-selectin in patients with human T-cell lymphotropic virus type I-associated myelopathy

We compared soluble E-selectin (sE-selectin) and L-selectin (sL- selectin) levels in sera and cerebrospinal fluid (CSF) of 30 patients with human T-lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM), with those of 10 patients with the relapsing-remitting form of multiple sclerosis (MS), and 16 patients with other neurological diseases (OND). Serum levels of both sE-selectin and sL-selectin, as measured by enzyme-linked immunosorbent assay, were significantly elevated in patients with HAM, compared to patients with OND. In addition, serum levels of sL-selectin were significantly elevated in HAM patients compared to MS patients. No significant difference was found in CSF levels of sL-selectin between HAM patients and controls. However, HAM patients who had received blood transfusions had significantly higher CSF levels of sL-selectin than HAM patients without a past history of transfusions, suggesting that HAM patients with past history of transfusion have a more active immunological state in the central nervous system. sE-selectin was not detected in CSF of HAM patients and controls. This finding might be based on exaggerated inflammatory conditions following increased attachment of lymphocytes to activated endothelial cells in HAM patients.

Use of fructose 1,6-diphosphate aldolase to detect tumour necrosis after transcatheter arterial embolization of hepatocellular carcinoma

Transcatheter arterial embolization (TAE) is a popular and well-established devascularization treatment modality for hepatocellular carcinoma (HCC). The persistent retention of lipiodol on follow-up computed tomography (CT) scan and time-dependent decrease in size of the lipiodol-stained area of tumour after TAE does not reveal the biological death of tumour cells. Moreover, it is difficult to clinically evaluate the effective necrosis of tumour cells by TAE in cases of HCC that do not produce alpha-fetoprotein (AFP). We therefore studied the release of a relatively tumour-specific protein by the necrotic hepatoma cells to evaluate the effectiveness of TAE. Transcatheter arterial embolization was performed in 17 patients with the imaging diagnosis of HCC; either superselective (n = 6) or non-superselective (n = 11) techniques were used. We measured serum levels of relatively tumour-specific fructose 1,6-diphosphate (FDP) aldolase and non-tumour-specific fructose 1-phosphate (F1P) aldolase by substrate-specific enzymatic methods. Enzyme activities were performed before and after TAE. The time-dependent decrease in size of the lipiodol-stained areas was studied on follow-up CT scans after TAE. Pre- and post-treatment serum AFP levels were determined by radio-immunoassay. The six cases of superselective TAE underwent marked tumour regression by CT compared with the 11 cases of non-superselective TAE. Fructase 1,6-diphosphate aldolase output correlated well with post-necrotic tumour regression after TAE (r = 0.87, P= 0.001). The elevation of serum FDP aldolase was also significantly associated with a decrease in serum AFP (r = 0.72, P < 0.01). In contrast, serum F1P aldolase output was inversely correlated with either tumour regression or serum AFP concentrations after TAE. The serum levels of the tumour-specific enzyme FDP aldolase correlated significantly with effective tumour necrosis and consequent tumour regression after TAE. We suggest that measurement of FDP aldolase activity in serum after TAE can be used clinically to detect the degree of tumour necrosis by TAE.

Modulation of Fas-mediated apoptosis of human thyroid epithelial cells by IgG from patients with Graves' disease (GD) and idiopathic myxoedema

The expression of two autoimmune thyroid diseases. GD and idiopathic myxoedema, is associated with antibodies to the thyroid-stimulating hormone (TSH) receptor. Thyroid stimulating antibodies (TSAb) in GD are TSH agonists and cause hyperthyroidism as well as goitre, whereas thyroid stimulation blocking antibodies (TSBAb) in idiopathic myxoedema are TSH antagonists and cause hypothyroidism and thyroid atrophy. We investigated the effect of antibodies to TSH receptor on Fas-mediated apoptosis of thyroid epithelial cells (thyrocytes). Human IgG was isolated from healthy donors, patients with GD and idiopathic myxoedema. Human thyrocytes were obtained from surgical specimens. Thyrocytes were cultured in the presence or absence of human IgG with or without interferon-gamma (IFN-gamma) or IL-1beta for a specified time. After incubation, we examined the level of cAMP in cultured supernatants and both Fas and Bcl-2 expression on thyrocytes. In addition, we examined anti-Fas-mediated apoptosis of thyrocytes. Fas expression on thyrocytes was significantly down-regulated by Graves' IgG and TSH, although idiopathic myxoedema IgG did not affect Fas expression on thyrocytes. Idiopathic myxoedema IgG abrogated the effect of TSH on both cAMP production and inhibition of Fas expression on thyrocytes. Treatment of thyrocytes with IL-1beta or IFN-gamma caused a marked augmentation of Fas expression on thyrocytes. The increase of Fas expression of thyrocytes induced by IL-1beta or IFN-gamma was significantly suppressed in the presence of TSH or Graves' IgG. Anti-Fas-induced apoptosis of thyrocytes was observed in thyrocytes treated with IL-1beta or IFN-gamma, but was markedly inhibited in the presence of TSH or Graves' IgG. Furthermore, idiopathic myxoedema IgG abrogated most of the inhibitory effect of TSH on Fas-mediated apoptosis of thyrocytes treated with IL-1beta or IFN-gamma. Bcl-2 expression of thyrocytes did not change after stimulation with TSH, Graves' IgG, idiopathic myxoedema IgG, IL-1beta or IFN-gamma. These results suggest that TSAb found in Graves' patients may be potentially involved in the development of goitre by inhibition of Fas-mediated apoptosis of thyrocytes. In addition, TSBAb inhibit the action of TSH and increase the sensitivity toward Fas-mediated apoptosis of thyrocytes, inducing thyroid atrophy seen in patients with idiopathic myxoedema.

FK506 potentiates steroid-induced T-cell apoptosis

BACKGROUND

FK506 and glucocorticoids are used for allograft rejection, graft-versus-host disease, and autoimmune diseases.

MATERIALS

We investigated the combined effect of FK506 and glucocorticoids on T-cell apoptosis.

RESULTS

Dexamethasone injection in mice reduced the number of CD4+CD8+ thymocytes by increasing DNA fragmentation. Pretreatment with FK506 significantly augmented thymocyte DNA fragmentation induced by dexamethasone injection. Increased thymic apoptosis resulted in the disappearance of CD4+CD8+ thymocytes after FK506/dexamethasone injection. In addition to thymocytes, mature human peripheral blood T cells undergo apoptosis by exposure to dexamethasone in vitro. FK506 synergistically enhanced dexamethasone-mediated apoptosis of human peripheral blood T cells.

CONCLUSIONS

Thus, our results showed that FK506 enhanced dexamethasone-induced apoptosis of T cells in vivo and in vitro. This interaction may enhance the therapeutic immunosuppression achieved by these two drugs.

Up-regulation of iNOS mRNA expression and increased production of NO in human monoblast cell line, U937 transfected by HTLV-I tax gene

We investigated the mRNA expression of inducible nitric oxide synthase (iNOS) and the production of nitric oxide (NO) in human T cell lymphotropic virus type I (HTLV-I) p40tax-transfected U937 cells, a human monoblast cell line. Transfection of HTLV-I p40tax U937 cells induced up-regulation of iNOS mRNA expression and subsequent NO production. Furthermore, interferon gamma (IFN-gamma) stimulation of HTLV-I p40tax-transfected U937 cells enhanced iNOS mRNA expression and NO production. The kinetics of iNOS mRNA expression and NO production indicated maximal effect at 24 and 48 hours, respectively, after culture with or without IFN-gamma. These findings suggest that HTLV-I p40tax can act as a transactivator of NO production in cells of Mo/M phi lineage. To what extent this mechanism may be involved in the pathogenesis of HTLV-I-associated diseases warrants further investigation.

Cultured oncogenic osteomalacia tumor cells produce a factor(s) that inhibits osteocalcin production by osteoblastic cells

A 34-year-old patient was diagnosed with oncogenic osteomalacia associated with hypophosphatemia, low levels of serum 1,25-dihydroxyviamin D [1,25(OH)(2)D], and osteocalcin (OC). Resection of the tumor normalized these blood abnormalities. While such tumors produce a humoral factor(s) that affects phosphate reabsorption by the proximal renal tubules, the direct action of such factor(s) on osteoblast function has not been examined previously. We investigated the effect of conditioned medium of cultured osteomalacia tumor cells on OC production by human osteoblastic cell line, MG-63. The conditiond medium inhibited OC production induced by 1,25(OH)(2)D-3. Our results indicate that the humoral factor(s) produced by the tumor has direct effect on osteoblasts and may contribute to development of the characteristic syndrome.

Signal transduction of granulocyte macrophage-colony stimulating factor in a human endothelium-derived cell line

Granulocyte macrophage-colony stimulating factor (GM-CSF) regulates the growth and differentiation of hematopoietic cells and is also involved in angiogenesis. The induction of protein tyrosine phosphorylation is critical for cytokines and growth factor-mediated signal transduction. The protein tyrosine kinase (PTK), JAK2 is involved in signaling through a number of cytokine receptors, including GM-CSF receptors. In the present study, we investigated the effect of GM-CSF on the cell cycle and protein tyrosine phosphorylation in a human endothelial cell-derived cell line, EA.hy 926 cells. GM-CSF induced the cell cycle progression and tyrosine phosphorylation of cellular proteins including JAK2 kinase in EA.hy 926 cells. Herbimycin A, a PTK inhibitor, completely blocked the GM-CSF-induced cell cycle progression, protein tyrosine phosphorylation and JAK2 kinase activation in EA.hy 926 cells. Our results demonstrate that protein tyrosine phosphorylation and JAK2 kinase activation are closely related to the GM-CSF-mediated signal transduction and growth in vascular endothelial cells, and suggest the efficacy of herbimycin A in controlling angiogenesis.

Beta 2-microglobulin induces stromelysin production by human synovial fibroblasts

beta 2-Microglobulin (beta 2-m) is a major constituent of amyloid fibrils in hemodialysis-associated amyloidosis (HAA), a serious complication in patients on long-term hemodialysis. The most distinctive pathological feature of HAA is the deposition of amyloid fibrils with subsequent articular inflammation and destruction. However, the pathological role of beta 2-m is not well known at present. We investigated the effects of beta 2-m on the production of proteinases from synovial fibroblasts isolated from patients with rheumatoid arthritis. beta 2-m stimulated synovial fibroblasts to produce stromelysin, a neutral matrix metalloproteinase (MMP-3). The production of MMP-2 and of a tissue inhibitor of metalloproteinase-1 (TIMP-1) were not enhanced by beta 2-m-treated synovial fibroblasts. Stromelysin is capable of degrading several components of the extracellular matrix and believed to be the key enzyme causing articular destruction in inflammatory joint diseases. Our results suggest a novel role for beta 2-m in articular inflammation and destruction mediated by stromelysin in HAA.

Successful application of pentoxifylline in the treatment of HTLV-I associated myelopathy

Fifteen patients with human T-cell lymphotropic virus type-I (HTLV-I)-associated myelopathy (HAM) were treated in an uncontrolled preliminary trial by oral administration of pentoxifylline (PTX). Motor function, neurological evaluation, immunological markers and parameters were evaluated after four weeks. In 13 of the 15 patients, motor disability, especially spasticity, improved substantially. PTX suppressed spontaneous proliferation of peripheral blood mononuclear cells in 14 of the 15 patients at four weeks. No adverse effect was observed. We concluded that PTX may be a safe and beneficial agent for the treatment of HAM.

Prevalence of goiter and urinary iodine excretion levels in children around Chernobyl

The prevalence of goiter among children living in areas affected by the Chernobyl accident was investigated by analysis of data on approximately 120,000 children examined at five medical diagnostic centers in Belarus, Russia, and the Ukraine. Examinations of thyroid gland were conducted with an arch-automatic ultrasonographic instrument at the five centers under the same protocol. The diagnosis of goiter was established when the thyroid volume exceeded a limit calculated from age, height, and body weight of a child. A considerable variation by region was noted in the prevalence of goiter. Highest in the Kiev region, the prevalence in the five regions was 54% in Kiev, 38% in the Zhitomir regions of the Ukraine, 18% in Gomel, 22% in the Mogilev regions of Belarus, and 41% in the Bryansk region of Russia. Urinary iodine content was measured in approximately 5700 children, and an endemic iodine deficient zone was confirmed in the Bryansk, Kiev, and Zhitomir regions. A significant negative correlation was observed between the prevalence of goiter and the median level of urinary iodine content (Spearman's rank correlation coefficient was -0.35, P = 0.025).

Fas and Fas ligand interaction is necessary for human osteoblast apoptosis

We investigated the cellular and humoral interactions between peripheral blood mononuclear cells (PBMCs) and human osteoblasts, leading to apoptosis of osteoblasts. Human osteoblastic cell line MG63 and human primary osteoblast-like cells obtained from biopsy specimens were used in this study. PBMCs were isolated from healthy donors and cultured with or without stimulation by recombinant interleukin-2 followed by 12-o-tetradecanoylphorbol 13-acetate with ionomycin. Fas was functionally expressed on MG63 and primary osteoblast-like cells. Activated PBMCs expressed Fas ligand (FasL) strongly on their surface and killed MG63 and primary osteoblast-like cells. Cultured supernatants of activated PBMCs also induced apoptotic cell death of MG63 and primary osteoblast-like cells. In contrast, both unstimulated PBMCs and cultured supernatants of unstimulated PBMCs did not induce apoptosis of these cells. Furthermore, the cytotoxic effect and induction of apoptosis against MG63 and primary osteoblast-like cells by activated PBMCs and cultured supernatants were inhibited significantly by human Fas chimeric protein. Our data showed that human osteoblasts expressed Fas fuctionally and both membrane-type and soluble form FasL from activated PBMCs induced apoptosis of these cells, providing the one possible mechanism of bone loss in inflammatory diseases such as rheumatoid arthritis.

Troglitazone ameliorates insulin resistance in patients with Werner's syndrome

Insulin resistance in Werner's syndrome (WS) is probably due to defective signaling distal to the insulin receptor. To analyze the metabolic effects of troglitazone (TRO) in these patients, we performed frequently sampled iv glucose tolerance tests. Glucose kinetics were analyzed by the minimal model. Five patients with WS (mean age, 41.2 yr; body mass index, 17.0 kg/m2) were treated with TRO (400 mg/day) for 4 weeks. Each subject underwent a 75-g OGTT and frequently sampled iv glucose tolerance tests. Treatment reduced the area under the curve of glucose and insulin in the OGTT by 26% and 43%, respectively. Glucose tolerance, as manifested by the glucose disappearance rate improved significantly (1.36 +/- 0.16 to 1.94 +/- 0.30%/min; P < 0.05). Although the first phase insulin secretion was unchanged, insulin sensitivity and glucose effectiveness increased significantly [0.47 +/- 0.11 to 1.38 +/- 0.37 x 10(-4) min/pmol.L (P < 0.05) and 1.72 +/- 0.17 to 2.52 +/- 0.24 x 10(-2) min-1 (P < 0.05), respectively]. However, treatment did not change glucose effectiveness at zero insulin. In patients with WS, TRO ameliorates glucose intolerance mediated by increased insulin sensitivity as well as glucose effectiveness, as assessed by minimal model analysis. TRO may modulate the postreceptor signaling component and be a clinically useful regimen for the treatment of patients with the intracellular insulin signaling defect.

[A case of malignant rheumatoid arthritis with transverse myelopathy and multiple lacunar infarction]

We reported a 34-year-old woman with malignant rheumatoid arthritis (MRA) associated with transverse myelopathy and multiple lacunar infarction. She had suffered from MRA for 9 years, then developed sensory disturbance of left big toe and weakness of right lower limb. Neurological examination revealed the muscle weakness of right lower limb. Deep tendon reflexes were hyperactive in bilateral lower limbs. Babinski's sign was positive bilaterally. Superficial sensation was decreased below Th10 level on the left side. Urinary bladder and rectal disturbance were not present. Laboratory examination disclosed perinuclear antineutrophil cytoplasmic autoantibody (p-ANCA) and anti-nuclear antibody (ANA). Multiple lacunar infarction and syringomyelia were found by MRI studies. Histological examinations of skin ulcer biopsied at 17 years of age disclosed vasculitis. We speculated that vasculitis associated with MRA might cause the damage of central nervous system (CNS) in our case. The p-ANCA may accelerate the vasculitic changes in CNS.

Shared TCR Vbeta gene expression by the pancreas and salivary gland in immunodeficient alymphoplasic mice

Mice with the homozygous mutation alymphoplasia (aly) lack lymph nodes and Peyer's patches and show defects in both humoral and cellular immunity. In these mice, spontaneous infiltration of mononuclear cells was observed in multiple exocrine organs, including the pancreas, salivary glands, and lacrimal glands from the age of 15 wk, progressing to a marked tissue destruction at the age of 25 wk. Using this strain, we examined the phenotypes and TCR Vbeta gene expression of infiltrating T cells to identify the pathologic role of T cell immunity in idiopathic pancreatitis. Most of the infiltrating cells were CD4+ and Thy-1+ cells. Analysis of the TCR gene expression on T cells infiltrating the pancreas and salivary glands showed a high expression of Vbeta1 and Vbeta5 in both organs at the age of 15 wk. In contrast, a diverse expression of TCR Vbeta genes was noted at 25 wk. Sequence analysis of complementarity-determining region 3 (CDR3) of the most prominent TCR Vbeta gene family expressed in these cells, Vbeta1, showed oligoclonal expansion of infiltrating T cells in both organs. Frequent use of glutamine and proline at position 97 was observed in paired tissues. Our data suggest that oligoclonal expansion of organ specific T cells might be one of the etiologic mechanisms of chronic pancreatitis and that common autoantigens could trigger autoimmunity in multiple organs.

Shared TCR Vbeta gene expression by the pancreas and salivary gland in immunodeficient alymphoplasic mice

Mice with the homozygous mutation alymphoplasia (aly) lack lymph nodes and Peyer's patches and show defects in both humoral and cellular immunity. In these mice, spontaneous infiltration of mononuclear cells was observed in multiple exocrine organs, including the pancreas, salivary glands, and lacrimal glands from the age of 15 wk, progressing to a marked tissue destruction at the age of 25 wk. Using this strain, we examined the phenotypes and TCR Vbeta gene expression of infiltrating T cells to identify the pathologic role of T cell immunity in idiopathic pancreatitis. Most of the infiltrating cells were CD4+ and Thy-1+ cells. Analysis of the TCR gene expression on T cells infiltrating the pancreas and salivary glands showed a high expression of Vbeta1 and Vbeta5 in both organs at the age of 15 wk. In contrast, a diverse expression of TCR Vbeta genes was noted at 25 wk. Sequence analysis of complementarity-determining region 3 (CDR3) of the most prominent TCR Vbeta gene family expressed in these cells, Vbeta1, showed oligoclonal expansion of infiltrating T cells in both organs. Frequent use of glutamine and proline at position 97 was observed in paired tissues. Our data suggest that oligoclonal expansion of organ specific T cells might be one of the etiologic mechanisms of chronic pancreatitis and that common autoantigens could trigger autoimmunity in multiple organs.

Inhibitory effects of interleukin-10 on synovial cells of rheumatoid arthritis

This paper describes the immunoregulatory effects of interleukin-10 (IL-10) on synovial cells in vitro. Synovial cells were cultured with IL-10 in the presence or absence of various cytokines. Following incubation, the costimulatory molecule expression on synovial cells and cytokine production in culture supernatants were analysed by an indirect immunofluorescence method and enzyme-linked immunosorbent assay, respectively. We also examined the effect of IL-10 on the function of synovial cells as antigen-presenting cells (APC). Synovial cells spontaneously express several kinds of costimulatory molecule and produce various kinds of cytokines. Stimulation of synovial cells with interferon-gamma (IFN-gamma), IL-1 beta, or 12-O-tetradecanoyl phorbol 13-acetate (TPA) markedly enhanced the expression of costimulatory molecules and cytokine production of these cells. Both spontaneous and up-regulated costimulatory molecule expression and cytokine production were significantly suppressed by the addition of IL-10. Autologous T-cell proliferation was stimulated by purified protein derivative (PPD) in IFN-gamma-treated synovial cells and treatment of these synovial cells with IL-10 also suppressed T-cell proliferation. Our results suggest that IL-10 has an inhibitory effect on synovial cells and is an important immunoregulatory component of the cytokine network in rheumatoid arthritis.

Thyroid dysfunction in patients with amyloid goitre

OBJECTIVES

Widespread amyloid deposition in the thyroid gland causes diffuse, clinically apparent enlargement of the thyroid (amyloid goitre: AG). The aim of this study was to clarify the abnormalities of thyroid function in patients with AG.

DESIGN

Thirty patients with secondary amyloidosis were retrospectively analysed. Their thyroid status was evaluated using the results of routine thyroid function tests and measurement of thyroid autoantibodies. Thyroid needle biopsy was carried out to identify amyloid deposition in the thyroid gland.

RESULTS

Thyroid enlargement was observed in 19 (63%) of 30 patients with amyloidosis. Eleven of these 19 patients had a thyroid biopsy and/or autopsy and amyloid deposition was histologically revealed in 10 (defined as AG) of these 11 patients. Nine of 10 patients (90%) with AG had abnormalities of thyroid function, including five patients with hypothyroidism, one with hyperthyroidism, one with transient hypothyroidism, and two with low T3 syndrome. Five had thyroid autoantibodies. The patient with hyperthyroidism had positive thyroid stimulating antibody (TSAb) and high 131I thyroidal uptake, suggesting the coexistence of Graves' disease. Another patient suffered from thyroidal pain and showed transient hypothyroidism, high level of serum thyroglobulin and low thyroidal uptake of 123I, the clinical course being compatible with subacute thyroiditis.

CONCLUSIONS

The incidence of thyroid abnormalities accompanied by AG, although asymptomatic, is unexpectedly high. Thyroid function should therefore be regularly assessed during follow-up of patients with systemic amyloidosis.