Publications by authors named "Akiko Oyamada"
Article Synopsis
- A study examined osteoporosis medication usage in 497 patients over 60 years with fragility hip fractures (FHF), revealing that only 25.5% maintained continuous medication for three years, while 44.1% received no treatment.
- It was found that a low Barthel index at discharge was a significant risk factor for both not starting treatment and not remaining on medication.
- The findings suggest addressing the issues around low Barthel index could improve treatment persistence and overall outcomes for patients at risk of osteoporosis-related fractures.
Article Synopsis
- This study examined the predictors of 1-year mortality after hip fractures in older patients in Japan, analyzing 497 individuals aged 60 and above.
- The findings revealed a mortality rate of 9.1%, with various factors influencing risk differently for men and women, such as previous fractures and body mass index.
- The researchers suggest that improving the Barthel index (a measure of daily living activities) could help prevent mortality, highlighting the need for targeted treatment strategies.
Article Synopsis
- The study aimed to identify immunologically active rheumatoid arthritis (RA) patients by detecting IgM anti-citrullinated protein antibodies (ACPA) in their serum.
- Using enzyme-linked immunosorbent assay, researchers analyzed IgM ACPA levels in 176 RA patients and considered the effects of IgM rheumatoid factor (RF) on detection accuracy.
- The findings indicated that many IgM antibodies detected were not specific to citrullinated proteins and were likely due to IgG ACPA-IgM RF complexes, revealing their potential role in RA's development.
Article Synopsis
- A patient with rheumatoid arthritis on methotrexate therapy developed severe swelling in the left elbow, leading to the discovery of tumor-like lesions through imaging.
- Subsequent tests revealed multiple lesions in the lungs and lymph nodes, prompting a biopsy that diagnosed the patient with methotrexate-related lymphoproliferative disorder (MTX-LPD).
- After stopping methotrexate, the swelling decreased and the patient achieved remission, highlighting the need to consider MTX-LPD in similar cases of joint swelling in RA patients on methotrexate.
Osteoporosis has become a worldwide public health problem, in part due to the fact that it increases the risk of fragility hip fractures (FHFs). The epidemiological assessment of FHFs is critical for their prevention; however, datasets for FHFs in Japan remain scarce. This was a multicenter, prospective, observational study in the northern district of Kyushu Island.
View Article and Find Full Text PDFArticle Synopsis
- Interleukin-21 (IL-21) is a cytokine that may have multiple roles in rheumatoid arthritis (RA) and its signaling was investigated in a study using IL-21 receptor knockout (Il21r KO) mice.
- The study involved immunizing both Il21r KO and wild-type mice with collagen to induce collagen-induced arthritis (CIA) and analyzed immune responses like antibody production and T-cell responses.
- Results showed that Il21r KO mice were resistant to CIA, revealing that IL-21 receptor expression on B cells is crucial for producing harmful autoantibodies, while T-cell responses were not affected.
Article Synopsis
- Tumor necrosis factor inhibitors (TNFi) like infliximab (IFX) are effective treatments for Ankylosing Spondylitis (AS), but there are limited studies on their effects specifically in the Japanese population.
- A study evaluated 11 AS patients treated with IFX, finding significant improvements in disease activity (BASDAI score) and inflammation markers (CRP levels) after an average of 19 months.
- The findings suggest that IFX is both effective and safe for treating AS in Japanese patients, with no serious side effects reported.
Article Synopsis
- - CD30, a receptor found on certain T cells, plays a key role in autoimmune responses, particularly in conditions like experimental autoimmune encephalomyelitis (EAE).
- - Mice lacking CD30 showed reduced levels of specific T cells that contribute to EAE, suggesting that CD30 is important for the disease's development.
- - The study indicates that CD30 signaling on CD4 T cells is crucial for the formation of T cells that cause brain inflammation, highlighting its significance in central nervous system autoimmunity.
Article Synopsis
- The study compares clinical outcomes of joint-preserving surgery (JP) and resection arthroplasty (RA) in patients with rheumatoid forefoot deformities, focusing on 23 feet from 17 patients over an average follow-up of 28 months.
- Both surgical methods showed significant postoperative improvements in foot function, but the JP group exhibited notably better results.
- The findings suggest that joint-preserving surgery may be more effective for certain patients than traditional resection arthroplasty based on improved alignment and function scores.
Article Synopsis
- - The study examined the time it takes for Japanese patients with ankylosing spondylitis (AS) to get diagnosed, finding a significant average delay of 6.7 years from the first symptoms to diagnosis.
- - Patients typically consulted around 2 to 3 medical institutions, with orthopedic surgeons being the most frequently visited specialists; prior misdiagnoses included non-specific back pain and degenerative arthritis.
- - Although the delay has improved for those diagnosed more recently (post-2000), ongoing medical education for identifying inflammatory back pain in younger patients is still necessary.
Article Synopsis
- A method was developed to culture synovial tissue explants from patients with rheumatoid arthritis (RA), utilizing air-liquid interface and submerged cultures for comparison.
- The study found that the air-liquid interface culture successfully preserved key features of RA, such as cellular infiltrate and maintained viable immune cells, while submerged cultures did not.
- Additionally, this method allowed for prolonged production of inflammatory cytokines, and the drug infliximab was shown to effectively reduce cytokine levels, indicating its potential for further RA research and therapy development.
The CD30 ligand (CD30L)/CD30 axis plays a critical role in Th1 and Th17 cell differentiation. However, the role in the pathogenesis of central nervous system autoimmunity remains unknown. Here we show the resistance for experimental autoimmune encephalomyelitis (EAE) with markedly reduced induction of antigen-specific Th1 and Th17 cells in CD30L knockout mice.
View Article and Find Full Text PDFArticle Synopsis
- IL-12 is crucial for promoting the development of Th1 cells that help defend against intracellular bacteria like Listeria monocytogenes.
- Research shows that while CD4 T cells with Th1 functions can naturally occur without the influence of IL-12 in mice lacking Tyk2, they still produce IFN-γ in response to IL-12.
- The study concludes that Tyk2 plays a varying role in the development of different Th1 cell subsets, but all rely on Tyk2 for effective IFN-γ production, which aids in early defense against infections.
Article Synopsis
- The study examined the effectiveness and safety of adalimumab in two groups of rheumatoid arthritis patients: those who had never received biologics (bio-naïve) and those who switched from another biologic (bio-switch).
- Results showed that 63% of bio-naïve patients were able to continue using adalimumab for two years, achieving significant improvements in disease activity and no progression in joint damage, while the bio-switch group had a much lower retention rate of 29%.
- The findings suggest adalimumab in combination with methotrexate is a strong first line treatment for bio-naïve patients, but should only be considered for bio-switch patients previously treated with infliximab.
Article Synopsis
- * Researchers identified different susceptible HLA molecules for GD (4 types) and HT (2 types), as well as specific protective HLA haplotypes that may prevent the development of these diseases.
- * The findings suggest that HLA plays a crucial role in the differing immunological pathways of GD and HT, indicating complex interactions between protective and susceptible HLA alleles.
Article Synopsis
- IL-2 signaling is crucial for the clonal expansion and development of Th1 (T helper 1) cells but has a limited role in the development of Th17 (T helper 17) cells, both in vitro and in vivo.
- Research shows that while Th17 cell differentiation is largely unaffected by the absence of IL-2, Th1 cell differentiation is significantly impaired without it.
- In experiments involving mice lacking IL-2 receptors, it was found that blocking IL-2 increases Th17 cell percentages but doesn’t boost overall numbers, confirming that Th17 development can occur independently of IL-2.
Article Synopsis
- Cord factor (TDM) is an effective mycobacterial adjuvant, and the study identifies MCL as a new receptor for TDM, which evolved from the Mincle receptor.
- MCL-deficient mice showed significantly impaired immune responses to TDM, including poor granuloma formation and reduced autoimmune reaction compared to normal mice.
- MCL plays a critical role in driving the immune response to TDM by activating Mincle, highlighting its importance in the immune system's response to mycobacterial infections.
Article Synopsis
- The study aimed to compare CD4 T cell populations in the joints of patients with rheumatoid arthritis (RA) and osteoarthritis (OA) to see if the predominance of Th1 cells in RA was unique.
- Using flow cytometry on samples from both types of patients, researchers found that CD4 T cells in RA joints showed high activation markers and a notable absence of Th17-related molecules, while Th1 cells were the majority in both RA and OA.
- The conclusion suggested that while there were differences in the quantity and expression of activation markers in CD4 T cells between RA and OA, the overall type of CD4 T cells present was quite similar across both conditions.
Article Synopsis
- Tyrosine kinase 2 (Tyk2) plays a key role in signaling related to IL-12 and IL-23, which are important in immune responses.
- In experiments using Tyk2 knockout (KO) mice, researchers found that these mice were resistant to experimental autoimmune encephalomyelitis (EAE), showing impaired Th1 cell differentiation and reduced Th1 cells, while Th17 cells were present but unresponsive to IL-23.
- The study suggests that Tyk2 is essential for pathogenic CD4 T cell responses in EAE, positioning it as a potential target for treating autoimmune diseases.
Article Synopsis
- HSV-2 causes acute infections that can become life-threatening, particularly in individuals with weakened immune systems, but the immune response mechanisms are not fully understood.
- This study investigated the role of Fas-FasL signaling in protecting against severe HSV-2 infection using genetically modified mice, finding increased mortality and viral levels in those lacking functional Fas or FasL.
- Results indicated that CD4+ T cells from healthy mice could protect others from lethal HSV-2 infection by inducing cell death in infected cells via FasL, highlighting the importance of this pathway in immune defense.