Surface modification of siliceous materials using maleimidation and various functional polymers synthesized by reversible addition-fragmentation chain transfer polymerization.

A novel surface modification method was investigated. The surface of siliceous materials was modified using polystyrene, poly(acrylic acid), poly(N-isopropylacrylamide), and poly(p-acrylamidophenyl-α-mannoside) synthesized by reversible addition-fragmentation chain transfer polymerization. Thiol-terminated polymers were obtained by reduction of the thiocarbonate group using sodium borohydride. The polymers were immobilized on the surface via the thiol-ene click reaction, known as the Michael addition reaction. Immobilization of the polymers on the maleimidated surface was confirmed by X-ray photoelectron spectroscopy, infrared spectroscopy, and contact angle measurements. The polymer-immobilized surfaces were observed by atomic force microscopy, and the thickness of the polymer layers was determined by ellipsometry. The thickness of the polymer immobilized by the maleimide-thiol reaction was less than that formed by spin coating, except for polystyrene. Moreover, the polymer-immobilized surfaces were relatively smooth with a roughness of less than 1 nm. The amounts of amine, maleimide, and polymer immobilized on the surface were determined by quartz crystal microbalance measurements. The area occupied by the amine-containing silane coupling reagent was significantly less than the theoretical value, suggesting that a multilayer of the silane coupling reagent was formed on the surface. The polymer with low molecular weight had the tendency to efficiently immobilize on the maleimidated surface. When poly(p-acrylamidophenyl-α-mannoside)-immobilized surfaces were used as a platform for protein microarrays, strong interactions were detected with the mannose-binding lectin concanavalin A. The specificity of poly(p-acrylamidophenyl-α-mannoside)-immobilized surfaces for concanavalin A was compared with poly-l-lysine-coated surfaces. The poly-l-lysine-coated surfaces nonspecifically adsorbed both concanavalin A and bovine serum albumin, while the poly(p-acrylamidophenyl-α-mannoside)-immobilized surface preferentially adsorbed concanavalin A. Moreover, the poly(p-acrylamidophenyl-α-mannoside)-immobilized surface was applied to micropatterning with photolithography. When the micropattern was formed on the poly(p-acrylamidophenyl-α-mannoside)-spin-coated surface by irradiation with ultraviolet light, the pattern of the masking design was not observed on the surface adsorbed with fluorophore-labeled concanavalin A using a fluorescent microscope because of elution of poly(p-acrylamidophenyl-α-mannoside) from the surface. In contrast, fluorophore-labeled concanavalin A was only adsorbed on the shaded region of the poly(p-acrylamidophenyl-α-mannoside)-immobilized surface, resulting in a distinctive fluorescent pattern. The surface modification method using maleimidation and reversible addition-fragmentation chain transfer polymerization can be used for preparing platforms for microarrays and micropatterning of proteins.

Influence of motorization and supermarket-proliferation on the prevalence of type 2 diabetes in the inhabitants of a small town on Okinawa, Japan.

BACKGROUND: Motorization and supermarket-proliferation affect lifestyles. About 15 years ago, Okinawans went to several shops on foot, but now they go to supermarkets by car. The influences of these changes on the prevalence of diabetes are uncertain. OBJECTIVE AND MEASUREMENTS: The influence of motorization and supermarket-proliferation on the prevalence of diabetes was studied in the inhabitants of a town on Okinawa, Japan. Measurements were composed of anthropometry and blood chemistry. Participants were asked where they buy food and daily necessities (several shops or a supermarket) and how they get there (by car or on foot). DESIGN: Serial cross-sectional. PARTICIPANTS: Inhabitants of the island of Okinawa were studied. RESULTS: In 1991, 24% went to several shops and 20% to a supermarket. However, in 2004, only 3.1% went to several shops and 83% to a supermarket. In 1991, 55% went to shopping places on foot and 38% by car. However, in 2004, only 14% went on foot and 76% by car. The prevalence of diabetes in Okinawa increased from 4.7% in 1991 to 8.4% in 2004. The prevalence of diabetes correlated positively with the percent of inhabitants going to supermarkets, and those going there by car. In 1991, the prevalence of type 2 diabetes was 4.7% in men and 4.6% in women; no difference was noted between men and women. In 2004, the prevalence of type 2 diabetes increased to 9.2% in men and to 7.5% in women. The increase in the prevalence of type 2 diabetes from 1991 to 2004 was higher in men than in women. CONCLUSIONS: About 15 years ago, Okinawans went to shops on foot, but now they go to supermarkets by car. The prevalence of diabetes is increasing. Motorization and supermarket-proliferation are associated with the increases of the prevalence of diabetes. The increase in diabetes prevalence was higher in men than in women.

False-positive 123I-metaiodobenzylguanidine (MIBG) scan in a patient with angiomyolipoma; positive MIBG scan does not necessarily indicate the presence of pheochromocytoma.

123I-Metaiodobenzylguanidine (123I-MIBG)-accumulation in angiomyolipoma (AML) is demonstrated. A 24-year-old Japanese woman presented with tumors in the right retroperitoneal space. The tumors, which accumulated 123I-MIBG, had been thought to be adrenal pheochromocytoma before surgery. They were removed, and were found to be AML. 123I-MIBG was accumulated in AML. 123I-MIBG-accumulation in AML led to a false-positive diagnosis of adrenal pheochromocytoma. Catecholamine levels had been normal. No chromaffin cells were found in the histological examination of the tumors. MIBG accumulation does not necessarily indicate the presence of pheochromocytoma.

CTLA-4 AT-repeat polymorphism reduces the inhibitory function of CTLA-4 in Graves' disease.

Graves' disease (GD) is thought to be an autoimmune disease with a strong genetic component. Candidate genes include human leukocyte antigen (HLA) class II genes and CTLA-4. The CTLA-4 gene has a variable length AT-repeat polymorphism in the 3'-untranslated region. We previously found that the AT-repeat of 104 bp or longer was associated with GD. In this study, we categorized patients with GD and normal controls (NC) by genotyping the CTLA-4 AT-repeat and investigated the function of CTLA-4. Peripheral blood mononuclear cells (PBMC) and DNA were prepared from adult Caucasians (NC = 34, GD = 37). Genotypes of the AT-repeat polymorphism were divided into three groups according to their alleles. We related the CTLA-4 polymorphism in each genotype to augmentation of T-cell proliferation induced by a soluble anti-CTLA-4 antibody during incubation with irradiated Epstein-Barr virus (EBV)-transformed B cells. Proliferation of T cells from subjects with the 86/86 bp (shorter) allele was less than T cells from patients with longer alleles. The length of the AT-repeat allele correlated inversely with augmentation of proliferation after CTLA-4 blockade in subjects with GD. The CTLA-4 AT-repeat polymorphism affects the inhibitory function of CTLA-4. The long AT-repeat allele is associated with reduced control of T-cell proliferation and thus contributes to the pathogenesis of GD.

Cytotoxic T-lymphocyte antigen-4 gene polymorphisms and human T-cell lymphotrophic virus-1 infection: their associations with Hashimoto's thyroiditis in Japanese patients.

Cytotoxic T-lymphocyte antigen-4 (CTLA-4) decreases the immune response of T cells by inactivating the signal that occurs with interaction between CD28 on T cells and B7 on antigen-presenting cells. Gene polymorphisms involving CTLA-4 promoter (-318 C/T), exon 1 (49 A/G), and exon 4 (microsatellite (AT)n) have been linked to Hashimoto's thyroiditis (HT) and other autoimmune diseases. HT also has a reported association with human T-cell lymphotrophic virus-1 (HTLV-1) infection. We investigated the occurrence of CTLA-4 polymorphisms in Japanese patients with HT with and without anti-HTLV-1 antibodies (HTLV-1 Ab). DNA samples from 143 patients with HT and 199 controls were subjected to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis using the restriction enzymes, Bbv 1, Tse 1, and Mse 1. In the HTLV-1 Ab-positive group the exon 1 G allele was more frequent in patients with HT than in controls (67% vs. 53%, p = 0.0377), and in HTLV-1 Ab-negative group it was also frequent in patients with HT than in controls (68% vs. 53%, p = 0.0041). Frequency of the G allele in HT with HTLV-1 Ab was comparable to those without HTLV-1 Ab. Frequency of polymorphism in the promoter did not differ between patients with HT and controls, nor between controls with and without HTLV-1 Ab. HTLV-1 infection is not associated with CTLA-4 polymorphisms in either HT or controls. HTLV-1 infection is not regulated by genetic factor such as CTLA-4, and may affect occurrence of HT as an independent purely environmental factor.

Remission of Graves' hyperthyroidism and A/G polymorphism at position 49 in exon 1 of cytotoxic T lymphocyte-associated molecule-4 gene.

We studied whether a patient with Graves' disease will go into remission during antithyroid drug (ATD) treatment. Remission of Graves' hyperthyroidism is predicted by a smooth decrease in TSH receptor antibody (TRAb) during ATD treatment. Cytotoxic T cell lymphocyte-associated molecule-4 (CTLA-4) may play an important role in the development of Graves' hyperthyroidism and in its remission. We studied A/G polymorphism at position 49 in exon 1 of the CTLA-4 gene in 144 Japanese Graves' patients. We intended to reveal the possible association of CTLA-4 gene polymorphism with the remission of Graves' hyperthyroidism. All patients with Graves' disease were treated with ATD. Thyroid-stimulating antibody and TSH binding inhibitory Ig were measured as TRAb. We analyzed CTLA-4 genotypes and alleles with PCR. We calculated the frequencies of CTLA-4 genotypes and alleles. A significant increase in the frequency of the G allele was seen in Graves' patients compared with controls (P = 0.0095). Graves' patients were divided into three groups (A, B, and C) according to time of TRAb disappearance after the start of ATD treatment. In group A patients TRAb had disappeared within 1 yr after the start of ATD treatment, in group B TRAb had disappeared between the beginning of the second year and the end of the fifth year of treatment, and in group C TRAb continued to be positive after 5 yr of ATD treatment. The frequencies of the GG genotype and the G allele were significantly higher in group C patients with persistently positive TRAb over 5 yr of ATD treatment than in the other groups (P < 0.0001). Group C patients did not have the AA genotype. The periods of time until remission were significantly shorter in the AA genotype. Graves' patients with the G allele need to continue ATD treatment for longer periods.