Association between single‐nucleotide polymorphisms in the SEC8L1 gene,which encodes a subunit of the exocyst complex,and rheumatoid arthritis in a Japanese population

Objective

To identify rheumatoid arthritis (RA) susceptibility genes in a Japanese population by conducting a large‐scale case–control association analysis and linkage disequilibrium (LD) mapping on chromosome 7q31–34, a candidate susceptibility locus identified in a preliminary genome‐wide scan in 53 Japanese families, using single‐nucleotide polymorphisms (SNPs).

Methods

We prepared 728 dense, evenly spaced SNPs with a minor allele frequency >0.15 in each gene locus on chromosome 7q31–34. Using these SNPs, a 2‐stage case–control analysis was performed on 760 RA patients (157 men and 603 women) and 806 non‐RA controls (189 men and 617 women). Haplotypes and LD mapping results were assessed based on SNP genotypes in 380 controls.

Results

Forty‐eight SNPs showed allele associations (P < 0.05) in the first set of DNA samples (380 RA cases and 380 non‐RA controls; first‐stage analysis). For 4 of the SNPs in the SEC8L1 gene, the association was replicated (P < 0.05) in the second, independent set of DNA samples (an additional 380 RA cases and 380 non‐RA controls; second‐stage analysis). When data from the 2 groups were combined, the most significant allele association was observed with SNP 441, an intronic SNP of the SEC8L1 gene (P = 0.000059). The SEC8L1 SNPs with significant allele associations were all located in a single conserved LD block (block 4). Haplotype analysis revealed the disease‐risk (P = 0.0015) and disease‐protective (P = 0.0000062) haplotypes. Resequencing of coding exons within block 4 did not identify any nonsynonymous SNPs. Real‐time quantitative polymerase chain reaction revealed that SEC8L1 was expressed ubiquitously in human tissues, including fibroblast‐like synoviocytes from RA patients.

Conclusion

Our locus‐wide association and LD analyses identified intronic SNPs and haplotypes in the SEC8L1 gene that are strongly associated with RA. We propose that SEC8L1, which encodes a component of the exocyst complex, is a candidate susceptibility gene for RA in the Japanese population.

     

Transport of D-[1-14C]-amino acids into Chinese hamster ovary (CHO-K1) cells: implications for use of labeled d-amino acids as molecular imaging agents

INTRODUCTION: The fact that d-amino acids have been found in various tissues and are involved in various functions is a clue to how to develop new imaging agents. We examined d-amino acid transport mechanisms in Chinese hamster ovary (CHO-K1) cells because CHO-K1 cells are widely used in biomedical studies and are thought to be useful for expression of genes involved in metabolism of D-amino acids. METHODS: Uptake experiments were performed. CHO-K1 cells cultured in 60-mm plastic culture dishes under ordinary culture conditions were incubated with 18.5 kBq of radiolabeled amino acid in 2 ml of phosphate-buffered-saline-based uptake solution at 37 degrees C. The following radiolabeled amino acid tracers were used: D-[1-(14)C]-alanine, L-[1-(14)C]-alanine, D-[1-(14)C]-serine, L-[1-(14)C]-serine, D-[1-(14)C]-methionine, L-[1-(14)C]-methionine, D-[1-(14)C]-phenylalanine, L-[1-(14)C]-phenylalanine, D-[1-(14)C]-leucine, L-[1-(14)C]-leucine, D-[1-(14)C]-valine, L-[1-(14)C]-valine, D-[1-(14)C]-tyrosine, L-[1-(14)C]-tyrosine, D-[1-(14)C]-glutamic acid, L-[1-(14)C]-glutamic acid, D-[1-(14)C]-lysine, L-[1-(14)C]-lysine, D-[1-(14)C]-arginine and L-[L-(14)C]-arginine. We tested the inhibitory effects of the following compounds (1.0 mM) on transport: 2-(methylamino)isobutyric acid (a specific inhibitor of system A, in Na(+)-containing uptake solution) and 2-amino-bicyclo[2,2,1]heptane-2-carboxylic acid (a specific inhibitor of system L, in Na(+)-free uptake solution). RESULTS: D-[1-(14)C]-methionine, D-[1-(14)C]-phenylalanine and D-[1-(14)C]-tyrosine accumulated mainly via system L. D-[1-(14)C]-alanine and D-[1-(14)C]-serine accumulated primarily via system ASC. High uptake of D-[1-(14)C]-alanine, D-[1-(14)C]-methionine, D-[1-(14)C]-phenylalanine and D-[1-(14)C]-leucine was observed. The uptake of radiolabeled serine, valine, tyrosine, glutamic acid and arginine into CHO-K1 was highly stereoselective for l-isomers. CONCLUSIONS: We observed high uptake of D-[1-(14)C]-alanine via system ASC (most likely alanine-serine-cysteine-selective amino acid transporter-1) and high uptake of D-[1-(14)C]-methionine and D-[1-(14)C]-phenylalanine via system L (most likely L-type amino acid transporter-1).     

Tissue engineering of small intestinal tissue using collagen sponge scaffolds seeded with smooth muscle cells

In a previously reported attempt to regenerate small intestine with autologous tissues, collagen scaffolds were used without cell seeding or with autologous mesenchymal stem cell seeding. However the regenerated intestine lacked a smooth muscle layer. To accomplish regeneration of a smooth muscle layer, this present study used collagen scaffolds seeded with the smooth muscle cells (SMC) in a canine model. Autologous SMC were isolated from stomach wall and cultured. Two types of scaffolds were fabricated: in SMC (+), cultured SMCs were mixed with collagen solution and poured into a collagen sponge; and in SMC (-), SMCs were omitted. Both scaffolds were implanted into defects of isolated ileum as a patch graft. Animals were euthanized at 4, 8, and 12 weeks; for the last time point, the ileal loop had been reanastomosed at 8 weeks. At 12 weeks, the SMC (-) group showed a luminal surface covered by a regenerated epithelial cell layer with very short villi; however only a thin smooth muscle layer was observed, representing the muscularis mucosae. In the SMC (+) group, the luminal surface was covered completely by a relatively well-developed epithelial layer with numerous villi. Implanted SMCs were seen in the lamina propria and formed a smooth muscle layer. Thus, we concluded that collagen sponge scaffolds seeded with autologous SMCs have a potential for small intestine regeneration.     

Role of inducible costimulator in the development of lupus in MRL/lpr mice

Inducible costimulator (ICOS) is a costimulatory molecule expressed in activated T cells and plays an important role in T-cell-dependent immune responses. We investigated the role of ICOS in the development of autoimmune diseases in MRL/Mpj-lpr/lpr (MRL/lpr) mice. ICOS was expressed on CD4(+) T cells from adult MRL/lpr mice. ICOS-deficient MRL/lpr mice showed mild lymphoadenopathy and a decreased memory type CD4(+) T cells in the spleen. The anti-dsDNA antibody levels were decreased. CD4(+) T cells from ICOS-deficient MRL/lpr mice showed less of a bias to Th1 and an enhanced production of IL-4 in response to anti-CD3 antibody in comparison to those from wild-type MRL/lpr mice. Although ICOS-deficiency abrogated renal vasculitis completely, the severity of glomerulonephritis was not altered. ICOS is considered to play a role in CD4(+) T cell activation, autoantibody production, and renal vasculitis. However, it is not essentially required in the development of glomerulonephritis.     

Osteoarthritis as a Cause of Locomotive Syndrome: Its Influence on Functional Mobility and Activities of Daily Living

“Locomotive syndrome” is defined as a condition associated with restriction in one’s ability to walk or lead a normal life due to a dysfunction in one or more of the parts of the locomotion system, including the muscles, bones, joints, cartilage or intervertebral discs. This syndrome especially refers to individuals who have come to need nursing care services because of problems with the locomotive organs, or those who have conditions which may require them to need such services in the near future. Recent epidemiological studies revealed that the one-fourth of elderly individuals who require special assistance or nursing care have locomotive disorders in Japan. Osteoarthritis of the knee (knee OA) and hip (hip OA), and osteoporosis and spinal canal stenosis due to spondylosis are three major locomotive disorders that cause elderly individuals require special assistance or nursing care. In this review, we focus on the effects of knee and hip OA on the lives of elderly individuals and the recent advantages in clinical research on the pathophysiology and management of these diseases.     

Shapability, memory, and luminal changes in microcatheters after steam shaping: a comparison of 11 different microcatheters

PURPOSE: The purpose of this study was to compare the characteristics of shaped microcatheters, including shapability, durability, and luminal changes. MATERIALS AND METHODS: Eleven brands of steam-shaped microcatheters and one brand of preshaped microcatheter were evaluated. There were 2 nonreinforced and 10 reinforced devices supported by coils. For evaluation of shapability, the tip angle of 6 samples of each brand were measured after steam-shaping for 20 seconds with a shaping mandrel bent at a 90 degrees or 150 degrees angle. The ability to maintain the shaped angle after guidewire insertion stress (durability) was compared by calculation of the change in the tip angle by using 3 samples of each brand. Luminal change after steam shaping was evaluated by calculation of narrowing rate of the smallest diameter and observation of the surface morphology of the mold of each catheter lumen by using a silicone polymer by means of a fluorescent projection method. RESULTS: The nonreinforced microcatheters and the fiber-braided microcatheter showed higher shapability than the others. The degree of distal microcatheter straightening with the microguidewire insertion was less pronounced in the preshaped microcatheter and the fiber-braided microcatheter. Spontaneous recovery to the initial tip angle 5 minutes after the guidewire procedure was observed in 10 brands to various degrees (87%-98%). Irregular luminal surface morphology at the angled portion was found in 6 reinforced brands. One nonreinforced catheter and the fiber-braided catheter showed high narrowing rates >6%. CONCLUSION: There are differences in shapabilty, durability, and luminal changes of steam shaping in 12 brands of microcatheters. These characteristics could be important factors in catheter choice for endovascular procedures.     

Infection control for the treatment of hematological malignancies: a survey of the Kyushu Hematology Organization for Treatment Study Group (K-HOT)

The Kyushu Hematology Organization for Treatment Study Group (K-HOT) consisted of 22 institutions specializing in hematology in Kyushu. This study is aimed at reviewing the daily practice of infection control for the treatment of hematological malignancies in our group. Nominal questionnaires were mailed to the hematology department in each institution from November 2001 to April 2002. For the first general surveys, 19 of 22 (86%) institutions responded. The second survey was mailed to the 19 respondents and 17 answered the detailed questionnaires with a response rate of 89%. Prophylactic use of trimethoprim-sulfamethoxazole (ST) against Pneumocystis carinii and anti-mycobacterial drugs in patients who had a history of tuberculosis was routine especially for patients with adult T-cell leukemia/lymphoma (ATL). Furthermore, the neutrophil counts to start a granulocyte-colony stimulating factor appeared to be high in ATL as compared with other hematological malignancies. In the setting of autologous stem cell transplantation (SCT), prophylactic use of acyclovir, immunoglobulin and ST was not routine and was reduced in duration, if used at all, as compared with allogeneic SCT. For allogeneic SCT, the cumulative dose of immunoglobulin significantly varied from institutions to institutions. The benefit of this study is the ability to recognize practical management patterns for infection control.     

Reverse sequencing syllables of spoken words activates primary visual cortex

Using fMRI, we investigated the neural correlates for sequencing the individual syllables of spoken words in reverse order. The comparison of this task to a control task requiring subjects to repeat identical syllables given acoustically revealed the activation of the primary visual cortex. Because one syllable is generally expressed by one kana character (Japanese phonogram), most subjects used a strategy in which the kana character string corresponding to the word was imagined visually and then read mentally in reverse order to perform the task effectively. Such strategy was not used during a control condition. These results suggest that the primary visual cortex plays a role in the generation of an imagined string.