Publications by authors named "Nobuaki Ito"

Context: Causative factors for ectopic ossifications in X-linked hypophosphatemia (XLH) remain to be elucidated.

Objective: This work aimed to investigate the genotype-phenotype correlations between the phosphate-regulating endopeptidase homologue, X-linked gene () and ectopic ossifications in XLH.

Methods: Biochemical data, spinal computed tomography scans, and x-rays of hip/knee joints were retrospectively reviewed.

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  • * The research included data from 147 patients (77 children and 70 adults) who were mostly treated with phosphate and active vitamin D, revealing significant challenges related to height, pain severity, and quality of life (QOL) in both age groups.
  • * Findings showed that while children reported low pain levels, adults experienced mild-to-moderate pain, with both groups experiencing low QOL, which highlights the ongoing need for better understanding and management strategies for XL
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Atrial fibrillation (AF) is the most common cardiac arrhythmia observed in the elderly. Its prevalence rises with age, particularly in individuals over 80 years old. While catheter ablation has emerged as a first line therapy for the patients with symptomatic AF, evidence on its application in elderly patients remains controversial.

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X-linked hypophosphatemia (XLH) is a genetic disease that results in excessive FGF23, chronic hypophosphatemia, and musculoskeletal abnormalities, with affected patients experiencing symptoms such as bone pain, bone deformity, fracture, and pseudofracture. Burosumab is a fully human monoclonal antibody that binds to FGF23, improving lowered serum 1,25(OH)D and phosphate levels in patients with XLH. There are insufficient data on the use of burosumab, its safety, and the outcomes of treated patients in a real-world setting.

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  • - A study analyzed 38 patients with rare subtrochanteric femoral fractures to identify underlying metabolic bone diseases associated with low bone formation, revealing that 4 of them had such disorders.
  • - The research aimed to evaluate the prevalence of risk factors like age, glucocorticoid use, and antiresorptive agents among the patients, many of whom were older adults with a history of these medications.
  • - Key findings included that some patients were diagnosed with specific conditions like hypophosphatemic osteomalacia and a genetic variant linked to bone health, emphasizing the need for clinicians to investigate latent bone diseases in patients with atypical femoral fractures.
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Background: In patients with chronic kidney disease (CKD), fibroblast growth factor (FGF)-23 is suspected to cause death or cardiovascular disease by inducing left ventricular hypertrophy (LVH).

Objectives: This study aims to quantify the mediational effect of LVH in the hypothetical causal pathway from FGF-23 to long-term adverse outcomes.

Methods: From 3,939 adults with CKD stages 2 to 4 enrolled in the CRIC (Chronic Renal Insufficiency Cohort) study, 2,368 participants with available data of FGF-23, left ventricular mass index at 1 year, and covariates were included.

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Chitosan is a product of deacetylated chitin and a natural polymer that is attractive as a functional and biocompatible material in the pursuit of alternative materials to synthetic plastics for a sustainable society. Although hierarchical architectures, from precise molecular structures to nanofibers and twisted structures, have been clarified, the expansion of the anisotropic microstructures of chitosan into millimeter-scale materials is in the process of development. In this study, a chitosan network was reconstructed from an aqueous solution by using the meniscus splitting method to form a three-dimensionally ordered microstructure.

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Background: While clinical features of KCNJ5-mutated aldosterone-producing adenoma (APA) have been reported, evidence of its clinical outcomes is lacking. We aimed to synthesize available literature about the associations between KCNJ5 mutation with cardiovascular and metabolic outcomes among patients with APA.

Methods: In this systematic review of observational studies, MEDLINE and Embase were searched through August 2022.

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  • Synthetic glucocorticoids (GCs) are widely used for treating autoimmune diseases but can lead to glucocorticoid-induced osteoporosis (GIOP), which significantly impacts patient quality of life and leads to fractures in many patients.
  • In 2014, the Japanese Society for Bone and Mineral Research established treatment guidelines for managing GIOP, using risk factors like age and bone density to determine appropriate therapy for patients on GC treatment for over three months.
  • The updated 2023 guidelines recommend starting osteoporosis medications, such as bisphosphonates and anti-RANKL antibodies, alongside GC therapy for high-risk patients to help prevent fractures.
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Introduction: Autosomal dominant hypophosphatemic rickets (ADHR) is caused by pathogenic variants in the fibroblast growth factor 23 (FGF23) gene, which plays a key role in the regulation of phosphorus metabolism. FGF23 has the RXXR motif recognized by furin, leading to cleavage between R179 and S180 and thereby inactivating the protein's function. Previously reported variants in FGF23 causing ADHR occurred only affecting residues R176 or R179, which are located in the RXXR motif, leading to impaired cleavage.

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Fibroblast growth factor 23 (FGF23) is a pivotal humoral factor for the regulation of serum phosphate levels and was first identified in patients with autosomal dominant hypophosphatemic rickets and tumor-induced osteomalacia (TIO), the most common form of acquired FGF23-related hypophosphatemic rickets/osteomalacia (FGF23rHR). After the identification of FGF23, many other inherited and acquired forms of FGF23rHR were reported. In this review article, the detailed features of each acquired FGF23rHR are discussed, including TIO, ectopic FGF23 syndrome with malignancy, fibrous dysplasia/McCune-Albright syndrome, Schimmelpenning-Feuerstein-Mims syndrome/cutaneous skeletal hypophosphatemia syndrome, intravenous iron preparation-induced FGF23rHR, alcohol consumption-induced FGF23rHR, and post-kidney transplantation hypophosphatemia.

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  • Extended curettage is used to treat infiltrative bone tumors, but its effectiveness for bone tumor-induced osteomalacia was previously unclear.
  • This study analyzed 12 patients who underwent extended curettage, finding an 83% remission rate and overall positive clinical outcomes, with most patients able to walk without assistance after surgery.
  • The results suggest that extended curettage is a beneficial treatment option, especially for tumors located in challenging areas where complete removal could lead to complications.
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  • Hypophosphatasia (HPP) is a genetic disorder that affects bone health, with adult-onset HPP being a milder form that appears after age 18, causing issues like osteomalacia.
  • A case study of a 64-year-old woman with pseudofractures and low alkaline phosphatase levels led to a diagnosis of HPP, confirmed by a specific genetic variant.
  • Treatment with asfotase alfa (AA) resulted in significant improvements in her bone healing and mobility over six months, suggesting that AA is effective for severe HPP cases, while also identifying a new variant in the gene responsible for the disease.
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The pathophysiology of hypophosphatemia.

Best Pract Res Clin Endocrinol Metab

March 2024

Article Synopsis
  • Identification of FGF 23 as a key regulator of serum inorganic phosphate levels has improved understanding of hypophosphatemic rickets and osteomalacia, making intact FGF23 measurement essential for diagnosis.
  • The article categorizes the causes of chronic hypophosphatemia into four main groups: FGF23-related issues, primary tubular dysfunctions, vitamin D metabolism disturbances, and PTH1R-related factors, with each group having inherited and acquired forms.
  • A flowchart is provided to assist in the differential diagnosis of chronic hypophosphatemia, alongside recommendations to measure bone-specific alkaline phosphatase to distinguish between types of hypophosphatemia.
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Congenital fibroblast growth factor 23 (FGF23)-related hypophosphatemic rickets/osteomalacia is a rare bone metabolism disorder characterized by hypophosphatemia and caused by genetic abnormalities that result in excessive secretion of FGF23. Hyp mice are a model of X-linked hypophosphatemia (XLH) caused by deletion of the PHEX gene and excessive production of FGF23. The purpose of this study was to investigate the potential of TM5614 as a therapeutic agent for the treatment of congenital FGF23-related hypophosphatemic rickets and osteomalacia in humans by administering TM5614 to Hyp mice and examining its curative effect on hypophosphatemia.

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Aging presents fundamental health concerns worldwide; however, mechanisms underlying how aging is regulated are not fully understood. Here, we show that cartilage regulates aging by controlling phosphate metabolism via ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1). We newly established an Enpp1 reporter mouse, in which an EGFP-luciferase sequence was knocked-in at the Enpp1 gene start codon (Enpp1/EGFP-luciferase), enabling detection of Enpp1 expression in cartilage tissues of resultant mice.

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Introduction: Although catheter ablation (CA) of tachycardia-bradycardia syndrome (TBS) in patients with atrial fibrillation (AF) is considered to be an effective treatment strategy, pacemaker implantations (PMIs) are often required even after a successful CA. This study aimed to elucidate the clinical predictors of a PMI after CA.

Methods: From 2011 to 2020, 103 consecutive patients diagnosed with TBS were retrospectively enrolled in the study.

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The vast majority of transcribed RNAs are noncoding RNAs. Among noncoding RNAs, long noncoding RNAs (lncRNAs), which contain hundreds to thousands of bases, have received attention in many fields. The vast majority of the constituent cells in bone tissue are osteocytes, but their regulatory mechanisms are incompletely understood.

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Purpose Of Review: The study aims to provide updated information on the genetic factors associated with the diagnoses 'Diffuse Idiopathic Skeletal Hyperostosis' (DISH), 'Ossification of the Posterior Longitudinal Ligament' (OPLL), and in patients with spinal ligament ossification.

Recent Findings: Recent studies have advanced our knowledge of genetic factors associated with DISH, OPLL, and other spinal ossification (ossification of the anterior longitudinal ligament [OALL] and the yellow ligament [OYL]). Several case studies of individuals afflicted with monogenic disorders, such as X-linked hypophosphatemia (XLH), demonstrate the strong association of fibroblast growth factor 23-related hypophosphatemia with OPLL, suggesting that pathogenic variants in PHEX, ENPP1, and DMP1 are associated with FGF23-phosphate wasting phenotype and strong genetic factors placing patients at risk for OPLL.

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Although there are a few case reports of patients with small cell lung cancer developing hypophosphatemia, detailed information on this condition is scarce. A 52-year-old patient with advanced stage small cell lung cancer developed hypophosphatemia (1.1 mg/dL) during chemotherapy.

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Article Synopsis
  • Adrenal infarction is a rare condition where parts of the adrenal glands get damaged, and it's often caused by blood conditions or diseases.
  • An 81-year-old man came to the hospital with severe back pain, and doctors found he had this condition linked to a blood disease called MDS/MPN.
  • This case is special because it's the first time someone has had adrenal infarction twice, and it shows how important it is to investigate the reasons behind these health issues.
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  • The study examined symptom patterns and insufficiency fractures in 33 patients with tumour-induced osteomalacia (TIO) from January 2000 to June 2022, emphasizing early diagnosis.
  • Major symptoms included low back pain, chest wall pain, and hip pain, with an average pain duration of 3.9 years before diagnosis.
  • Imaging revealed various insufficiency fractures, notably in the spine and lower limbs, highlighting that specific symptoms and fractures can indicate the presence of TIO.
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  • This study compares the performance of two FGF23 measurement kits: the automated CL kit and the manual MED kit, revealing that MED levels are consistently lower than those of the Kainos (KI) kit in both healthy individuals and patients with chronic hypophosphatemia.
  • A total of 580 samples were analyzed, with healthy individuals showing MED FGF23 levels averaging 38.0 pg/mL compared to KI levels at 40.9 pg/mL, and patients exhibiting MED levels averaging 130.2 pg/mL versus KI levels at 172.5 pg/mL.
  • The correlation analysis indicated a strong linear relationship between the two kits, suggesting that despite the lower measurements from MED, the method is
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Article Synopsis
  • - The study investigates the effectiveness of the Medfrontier FGF23 Intact immunoassay in diagnosing hypophosphatemia, specifically in conditions like tumor-induced osteomalacia (TIO) and X-linked hypophosphatemia (XLH), as variations between different assays can impact diagnosis effectiveness.
  • - Serum levels of intact FGF23 were found to be significantly higher in patients with TIO and XLH compared to healthy controls, however, no correlation was observed between FGF23 levels and phosphate concentrations in these groups.
  • - The results indicate that the MedFrontier iFGF23 assay is clinically sensitive and suitable for use in diagnosing FGF23-dependent hypophosphatemia across a diverse patient population.
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  • Tumor-induced osteomalacia (TIO) is often caused by phosphaturic mesenchymal tumors (PMTs), and complete tumor removal can cure TIO, but locating these tumors preoperatively is difficult using standard imaging methods.
  • The study evaluated the effectiveness of different imaging techniques—FDG-PET, SRS, and FGF23 venous sampling (FGF23VS)—in successfully localizing PMTs in patients with TIO.
  • Results showed that combining FDG-PET with FGF23VS achieved a 100% localization rate for PMTs, highlighting the importance of using multiple imaging methods for accurate diagnosis.
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