EFFECT OF ADDING HOME-BASED MODERATE-INTENSITY EXERCISE ON METABOLIC FUNCTIONS IN OLDER ADULTS WITH NON-COMMUNICABLE DISEASES WHO REGULARLY PERFORM GYM-BASED MODERATE-INTENSITY EXERCISE.

CONTEXT: Physical activity is important for the management of metabolic functions; however, little is known whether performing home-based moderate-intensity exercise (MIE) obtains further improvement on metabolic functions in adults with non-communicable diseases (NCDs) who already perform regular gym-based MIE. OBJECTIVE: The purpose of this study was to examine the effect of adding home-based MIE on metabolic functions in older adults with NCDs who have regularly performed gym-based MIE. DESIGN: This was a single-center randomized controlled study. The observation period was set for 24 weeks. SUBJECTS AND METHODS: Twenty-one older adults (age, 60-79 years) with uncomplicated NCDs, who have performed 30-40 min MIE, 2-3 days/week at a hospital gym for over 1 year, were randomly divided into two groups: performing home-based MIE, comprising aerobic and resistance exercises, at least 20 min/day, 3 days/week (HOME, n = 11), or not performing home-based MIE (CON, n = 10). All participants completed the study and continued their gym-based MIE as usual. RESULTS: After 24 weeks, there were no significant differences in the values of any outcomes. Conversely, the decrease in waist circumference (WC) was larger in the HOME group (-2.17 [-3.98, -0.36] cm) than in the CON group (0.57 [-1.42, 2.56] cm) (p < 0.05), although not in other outcomes. CONCLUSIONS: Although further studies are needed, we found that adding home-based MIE had a positive effect on WC, but little effect on other metabolic functions in older adults with NCDs who have continued regular gym-based MIE.

Long waiting time before tooth extraction may increase delayed wound healing in elderly Japanese.

In osteoporosis patients receiving antiresorptive medications, stopping the drug and delaying tooth extraction has been suggested to reduce the risk of osteonecrosis of the jaw (ONJ). However, postponing tooth extraction for ≥ 2 months was associated with an increased risk of delayed wound healing beyond 8 weeks after extraction, a risk factor for developing ONJ. INTRODUCTION: A long waiting time before tooth extraction could result from concern about a potential increased risk of osteonecrosis of the jaw (ONJ) in osteoporosis patients. We clarified whether a long waiting time before tooth extraction during the past year may be associated with an increased risk of delayed wound healing beyond 8 weeks after tooth extraction, which may be a risk factor of ONJ. METHODS: Of 5639 patients aged ≥ 60 years who visited our 20 clinics or hospitals and answered a structured questionnaire, 426 patients (151 men, 275 women) aged 60-96 years comprised the final participants in this study. Self-reported kyphosis was used as a surrogate marker of vertebral fractures. Stepwise logistic regression analysis, adjusted for covariates, was used to calculate the odds ratio (OR) and the 95% confidence interval (CI) for the presence of delayed wound healing longer than 8 weeks after tooth extraction during the past year based on the duration before extraction. RESULTS: Subjects who had waited > 2 months for tooth extraction had a significantly higher risk of delayed wound healing compared with those whose tooth was extracted within 1 month (OR = 7.23; 95% CI = 2.19-23.85, p = 0.001) regardless if antiresorptive medications for osteoporosis were used. The presence of self-reported kyphosis was significantly associated with an increased risk of delayed wound healing (OR = 5.08; 95% CI = 1.11-23.32, p = 0.036). CONCLUSIONS: A long waiting time before tooth extraction may be a risk factor for delayed wound healing beyond 8 weeks after extraction in patients aged ≥ 60 years.

Smectic Liquid-Crystalline Structure of Skyrmions in Chiral Magnet Co_{8.5}Zn_{7.5}Mn_{4}(110) Thin Film.

The organizing of magnetic skyrmions shows several forms similar to atomic arrays of solid states. Using Lorentz transmission electron microscopy, we report the first direct observation of a stable liquid-crystalline structure of skyrmions in chiral magnet Co_{8.5}Zn_{7.5}Mn_{4}(110) thin film, caused by magnetic anisotropy and chiral surface twist. Elongated skyrmions are oriented and periodically arranged only in the ⟨110⟩ directions, whereas they exhibit short-range order along the ⟨001⟩ directions, indicating a smectic skyrmion state. In addition, skyrmions possess anisotropic interaction with an opposite sign depending on the crystal orientation, in contrast to existing isotropic interaction.

Prospective study of deep vein thrombosis in patients with spinal cord injury not receiving anticoagulant therapy.

STUDY DESIGN: Prospective cross-sectional study. OBJECTIVES: To investigate the timing of deep vein thrombosis (DVT) onset secondary to spinal cord injury without anticoagulant therapies. SETTING: Spinal Cord Injury Center in Hokkaido, Japan. METHODS: Between November 2012 and June 2013, patients with spinal cord injury who were admitted to our hospital within 1 day after the injury and treated surgically within 24 h underwent a neurological examination, leg vein ultrasonography and D-dimer test 1, 3, 7, 14 and 28 days after surgery. All patients received treatment with intermittent pneumatic compression and elastic stockings, but without any anticoagulant. RESULTS: DVT developed in 12 patients (11 men and 1 women), with a mean age of 62.2 years (range, 41-80 years; mean age of total sample, 63.2 years (range, 25-78 years)), all distal to the popliteal vein. DVT occurred more often with a more severe paralysis (66.3%, AIS A and B). The median (± standard error) length of time from the operation to DVT detection was 7.5±2.2 days. The mean D-dimer level upon DVT detection was 14.6±11.8 µg ml(-1), with no significant differences between those who developed DVT and those who did not at any of the time points. CONCLUSION: These results suggest that DVT can develop at the very-acute stage of spinal cord injury and the incidence increases with a more severe paralysis. DVT detection was more reliable with ultrasonography, which should be used with DVT-preventive measures, beginning immediately after the injury, for the management of patients with spinal cord injury.

Genetic polymorphism in IFNL4 and response to pegylated interferon-α and ribavirin in Japanese chronic hepatitis C patients.

A genetic polymorphism of the newly discovered interferon-λ 4 (IFNL4) gene was associated with hepatitis C virus (HCV) clearance in individuals of African ancestry. To assess whether a dinucleotide variant of IFNL4 (ss469415590) also affected treatment outcome of antiviral therapy in Japan, we genotyped 213 patients with chronic genotype 1 HCV infection and 176 healthy subjects. The ΔG allele was associated with treatment failure [odds ratio (OR) 4.73, P = 0.019], as was the IFL3 rs8099917 single nucleotide polymorphism (SNP) (OR 5.06, P = 0.068). The correlation between ss469415590 and rs8099917 was high (r(2) = 0.92, D' = 0.98). Multivariate analysis revealed that the rs8099917 SNP was independently associated with treatment failure (OR 5.28, P = 0.009). Therefore, ss469415590 may be another predictive marker of antiviral therapy outcome in the Japanese population.

Efficacy and toxicity of (chemo)radiotherapy for primary subglottic cancer.

BACKGROUND AND PURPOSE: Primary subglottic cancer is a rare malignancy. We investigated the efficacy and toxicity of radiotherapy for subglottic cancer. PATIENTS AND METHODS: Nineteen patients with primary squamous cell carcinoma of the subglottis received radiotherapy, 14 of whom also underwent chemotherapy. Of the 19 patients, 15 received definitive radiotherapy to the gross tumors with total doses of 70-70.2 Gy in 35-39 fractions, and 4 underwent preoperative radiotherapy with total doses of 37.8-55.8 Gy in 21-31 fractions, followed by total laryngectomy. RESULTS: Of the 19 patients, 5 developed local progression and 2 developed distant metastasis at the median follow-up period of 5 years. The 5-year local control and disease-free rates were 74 and 63%, respectively. Three patients died of tumor progression, and the 5-year overall and disease-free survival rates were 80 and 63%, respectively. Regarding acute toxicities, transient mucositis and dermatitis of grade 3 or lower were observed in all patients, but there were no late toxicities of grade 3 or higher. CONCLUSION: Radiotherapy is a safe and effective treatment for patients with primary squamous cell carcinoma of the subglottis. The use of chemotherapy together with radiotherapy may enhance treatment efficacy and contribute to larynx preservation through good local control.

Possible roles of the AP-1 site in the cytosolic T3 binding protein promoter and insights into its physiological significance.

Cytosolic 3,5,3'-triiodo-l-thyronine-binding protein plays pivotal roles in the regulation of intracellular 3,5,3'-triiodo-l-thyronine concentration in vivo. The expression of the protein, which is identical to µ-crystallin, is regulated by various factors. To elucidate the mechanisms of its expression, we evaluated the promoter transactivity and insulin signaling via the AP-1 site in the promoter. The isolated 600 bp human and 1976 bp mouse 5'-flanking regions were cloned in a luciferase reporter plasmid. The luciferase activity was estimated in GH3, dRLh-84, HEK293, and insulin receptor-overexpressing CHO-IR cells. The effects of 12-O-tetradecanoylphorbol 13-acetate and insulin on µ-crystallin mRNA expression were evaluated in various cells. The region between -200 and the transcriptional start site was crucial for constitutive expression in µ-crystallin-expressing dRLh-84 cells. This region contained an AP-1 site. 12-O-Tetradecanoylphorbol 13-acetate increased the level of µ-crystallin mRNA expression in HEK 293 cells. The compound also increased luciferase activity through the promoter. Mutation in the AP1 site diminished the response to the compound. The promoter was also activated by insulin treatment in CHO-IR cells. Insulin treatment increased µ-crystallin mRNA expression in Raw264.7 cells, but decreased in HEK293, P19, and dRLH-84 cells. The expression of µ-crystallin was regulated through the AP-1 site in the promoter. The signals related to AP-1 activation, such as insulin signaling may have diverse effects on µ-crystallin mRNA expression.

Clinical features of a new disease concept, IgG4-related thyroiditis.

OBJECTIVES: Immunoglobulin (Ig)G4-related disease is a recently proposed systemic disorder that includes autoimmune pancreatitis (AIP), Mikulicz's disease, and various other organ lesions. In the present retrospective study, we examined whether thyroid lesions should also be included in IgG4-related disease (Ig4-RD) under the new term IgG4-related thyroiditis. METHOD: We enrolled 114 patients with Ig4-RD, including 92 patients with AIP, 15 patients with Mikulicz's disease, and seven patients with IgG4-related cholangitis, and analysed clinical findings, function, serum values of activity markers, computed tomography (CT) images, and histology of the thyroid gland. RESULTS: Among the 22 patients (19%) in our cohort who were found to have hypothyroidism [thyroid stimulating hormone (TSH) > 4 mIU/L], 11 patients had clinical hypothyroidism [free thyroxine (FT4) < 1 ng/dL] and 11 patients had subclinical hypothyroidism (FT4 ≥ 1 ng/dL). Serum concentrations of IgG, IgG4, circulating immune complex (CIC), and ß2-microglobulin (ß2-MG) were significantly higher in the hypothyroidism group compared with the remaining 92 euthyroid patients, and serum C3 concentration was significantly lower. After prednisolone treatment, TSH values had decreased significantly (p = 0.005) in this group and FT4 values had increased significantly (p = 0.047). CT images showed that the thyroid glands of patients with clinical hypothyroidism had a significantly greater volume than those of the euthyroid and other groups. Pathological analysis of one resected thyroid gland disclosed a focused lesion with infiltration of lymphocytes and IgG4-bearing plasma cells and loss of thyroid follicles. CONCLUSIONS: Thyroid lesions associated with hypothyroidism can be considered as a new disease termed IgG4-related thyroiditis. Awareness of this condition should lead to appropriate corticosteroid treatment that may prevent progression to a fibrous state.

Loss of autophagy in erythroid cells leads to defective removal of mitochondria and severe anemia in vivo.

Timely elimination of damaged mitochondria is essential to protect cells from the potential harm of disordered mitochondrial metabolism and release of proapoptotic proteins. In mammalian red blood cells, the expulsion of the nucleus followed by the removal of other organelles, such as mitochondria, are necessary differentiation steps. Mitochondrial sequestration by autophagosomes, followed by delivery to the lysosomal compartment for degradation (mitophagy), is a major mechanism of mitochondrial turnover. Here we show that mice lacking the essential autophagy gene Atg7 in the hematopoietic system develop severe anemia. Atg7(-/-) erythrocytes accumulate damaged mitochondria with altered membrane potential leading to cell death. We find that mitochondrial loss is initiated in the bone marrow at the Ter119(+)/CD71(High) stage. Proteomic analysis of erythrocyte ghosts suggests that in the absence of autophagy other cellular degradation mechanisms are induced. Importantly, neither the removal of endoplasmic reticulum nor ribosomes is affected by the lack of Atg7. Atg7 deficiency also led to severe lymphopenia as a result of mitochondrial damage followed by apoptosis in mature T lymphocytes. Ex vivo short-lived hematopoietic cells such as monocytes and dendritic cells were not affected by the loss of Atg7. In summary, we show that the selective removal of mitochondria by autophagy, but not other organelles, during erythropoeisis is essential and that this is a necessary developmental step in erythroid cells.

Antiplatelet drugs may increase the risk for checkpoint inhibitor-related pneumonitis in advanced cancer patients.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are indicated for various cancers and are the mainstay of cancer immunotherapy. They are often associated with ICI-related pneumonitis (CIP), however, hindering a favorable clinical course. Recently, non-oncology concomitant drugs have been reported to affect the efficacy and toxicity of ICIs; however, the association between these drugs and the risk for CIP is uncertain. The aim of this study was to assess the impact of baseline concomitant drugs on CIP incidence in ICI-treated advanced cancer patients. PATIENTS AND METHODS: This was a single-center retrospective study that included a cohort of 511 patients with advanced cancer (melanoma and non-small-cell lung, head and neck, genitourinary, and other types of cancer) treated with ICIs. Univariable analysis was conducted to identify baseline co-medications associated with CIP incidence. A propensity score matching analysis was used to adjust for potential CIP risk factors, and multivariable analysis was carried out to assess the impact of the identified co-medications on CIP risk. RESULTS: Forty-seven (9.2%) patients developed CIP. In these patients, the organizing pneumonia pattern was the dominant radiological phenotype, and 42.6% had grade ≥3 CIP, including one patient with grade 5. Of the investigated baseline co-medications, the proportion of antiplatelet drugs (n = 50, 9.8%) was higher in patients with CIP (23.4% versus 8.4%). After propensity score matching, the CIP incidence was higher in patients with baseline antiplatelet drugs (22% versus 6%). Finally, baseline antiplatelet drug use was demonstrated to increase the risk for CIP incidence regardless of cancer type (hazard ratio, 3.46; 95% confidence interval 1.21-9.86). CONCLUSIONS: An association between concomitant antiplatelet drug use at baseline and an increased risk for CIP was seen in our database. This implies the importance of assessing concomitant medications for CIP risk management.

Autophagy deficiency in beta cells leads to compromised unfolded protein response and progression from obesity to diabetes in mice.

AIMS/HYPOTHESIS: The unfolded protein response (UPR) in endoplasmic reticulum (ER) and autophagy are known to be related. We investigated the role of autophagy in UPR of pancreatic beta cells and the susceptibility of autophagy-deficient beta cells to the ER stress that is implicated in the development of diabetes. METHODS: Rat insulin promoter (RIP)-Cre(+);autophagy-related 7 (Atg7)(F/W) mice were bred with ob/w mice to derive RIP-Cre(+);Atg7(F/F)-ob/ob mice and to induce ER stress in vivo. GFP-LC3(+)-ob/ob mice were generated to examine in vivo autophagic activity. Real-time RT-PCR was performed to study the expression of the genes of the UPR machinery. Proteolysis was assessed by determining release of incorporated radioactive leucine. RESULTS: Production of UPR machinery was reduced in autophagy-deficient beta cells, which was associated with diminished production of p85α and p85ß regulatory subunits of phosphoinositide 3-kinase. Because of compromised UPR machinery, autophagy-deficient beta cells were susceptible to ER stressors in vitro. When mice with beta cell-specific autophagy deficiency, which have mild hyperglycaemia, were bred with ob/ob mice to induce ER stress in vivo, severe diabetes developed, which was accompanied by an increase in beta cell death and accumulation of reactive oxygen species. The increased demand for UPR present in obesity was unmet in autophagy-deficient beta cells. Autophagy level and autophagic activity were enhanced by lipid, while proteolysis was reduced. CONCLUSIONS/INTERPRETATION: These results suggest that autophagy is important for intact UPR machinery and appropriate UPR in response to lipid injury that increases demand for UPR. Autophagy deficiency in pancreatic beta cells may contribute to the progression from obesity to diabetes.

Spin polarization of gapped Dirac surface states near the topological phase transition in TlBi(S(1-x)Se(x))2.

We performed systematic spin- and angle-resolved photoemission spectroscopy of TlBi(S(1-x)Se(x))(2) which undergoes a topological phase transition at x ~ 0.5. In TlBiSe(2) (x = 1.0), we revealed a helical spin texture of Dirac-cone surface states with an intrinsic in-plane spin polarization of ~0.8. The spin polarization still survives in the gapped surface states at x > 0.5, although it gradually weakens upon approaching x = 0.5 and vanishes in the nontopological phase. No evidence for the out-of-plane spin polarization was found, irrespective of x and momentum. The present results unambiguously indicate the topological origin of the gapped Dirac surface states, and also impose a constraint on models to explain the origin of mass acquisition of Dirac fermions.

Molecular epidemiology of meticillin-susceptible Staphylococcus aureus in the neonatal intensive care unit.

BACKGROUND: Staphylococcus aureus - both meticillin-resistant S. aureus (MRSA) and meticillin-susceptible S. aureus (MSSA) - is a major cause of neonatal infections. Infection control measures have not lowered the incidence of MSSA infections to the same degree as that of MRSA infections. AIM: To investigate the transmission pathway of MSSA in neonatal intensive care unit (NICU) using genetic analysis. METHODS: Neonatal patients, their parents, and healthcare workers were swab-tested in the NICU at our hospital at the time of hospitalization and then every month thereafter from October 1st, 2018 to March 31st, 2019. Whole-genome sequencing was performed to test for MSSA strains. Multi-locus sequence typing and single nucleotide polymorphism analysis were used to identify strains and understand their relatedness. FINDINGS: There were 16 MSSA-positive patients. Four MSSA-positive patients shared strains from the same phylogenetic groups as those of healthcare workers. One presented the same strain as the parent. MSSA-positive twin neonates shared the same strain. Ten had sporadic strains; 32 of the 97 tested healthcare workers were MSSA positive. CONCLUSION: The findings of this study suggest that the route of transmission of MSSA in NICU may be through MSSA in the hospital environment in addition to horizontal transmission via healthcare workers. Along with hand hygiene with alcohol, thorough environmental maintenance and parental education are important for infection control in NICUs targeting MSSA.

Expressions of PD-L1 and Nectin-4 in urothelial cancer patients treated with pembrolizumab.

OBJECTIVES: Recently, the standard of care for advanced urothelial cancer (UC) has been changed by developing immune-checkpoint inhibitors (ICIs). However, its response rate is limited to 20-30%. The identification of biomarkers to predict the therapeutic effects of ICIs is urgently needed. The present study explored the association between immunohistochemical biomarkers and clinical outcomes in UC patients treated with pembrolizumab. PATIENTS AND METHODS: A total of 85 patients with UC who received pembrolizumab after chemotherapy from January 2018 to May 2020 were retrospectively reviewed. Tumor tissues were obtained for immunohistochemical study from 47 out of 85 patients. The protein expressions of PD-L1, WT1, Nectin-4, CD4, CD8, Foxp3, and CD68 in tumor cells and/or tumor infiltrating lymphocytes were immunohistochemically examined. The associations between protein expressions and overall survival (OS), progression-free survival (PFS), and disease control rate (DCR) were statistically analyzed. RESULTS: Patients with positive PD-L1 in tumor cells showed significantly worse OS (Log-rank test: HR 5.146, p = 0.001, Cox regression analysis: HR 4.331, p = 0.014) and PFS (Log-rank test: HR 3.31. p = 0.022), along with significantly lower DCR (14.3%) compared to the PD-L1 negative patients (67.5%). In addition, patients with strong expression of Nectin-4 in tumor cells showed significantly higher DCR (100%) than the other patients (50%). CONCLUSION: PD-L1 expression in tumor cells was associated with poor prognosis (OS and PFS) and low DCR. Interestingly, the strong expression of Nectin-4 was correlated with high DCR. PD-L1 and Nectin-4 expression in tumor cells could be prognostic biomarkers useful for pembrolizumab in patients with advanced UC.

Direct measurement of the out-of-plane spin texture in the Dirac-cone surface state of a topological insulator.

We have performed spin- and angle-resolved photoemission spectroscopy of Bi(2)Te(3) and present the first direct evidence for the existence of the out-of-plane spin component on the surface state of a topological insulator. We found that the magnitude of the out-of-plane spin polarization on a hexagonally deformed Fermi surface of Bi(2)Te(3) reaches maximally 25% of the in-plane counterpart, while such a sizable out-of-plane spin component does not exist in the more circular Fermi surface of TlBiSe(2), indicating that the hexagonal deformation of the Fermi surface is responsible for the deviation from the ideal helical spin texture. The observed out-of-plane polarization is much smaller than that expected from the existing theory, suggesting that an additional ingredient is necessary for correctly understanding the surface spin polarization in Bi(2)Te(3).

Endoscopic anatomy of persistent trigeminal artery: a cadaveric study.

BACKGROUND: Persistent trigeminal artery (PTA) is one of the carotid-basilar anastomoses and occasionally complicates vascular or neoplastic pathology. The aim of this study was to become more familiar with the anatomy associated with PTA using an endoscopic view. MATERIAL AND METHODS: PTA was incidentally encountered in a fresh cadaver. Purely endoscopic approaches via supraorbital (extradural and intradural routes), endonasal, and retrosigmoid routes were performed with 4-mm, 0- and 30-degree rigid endoscopes. RESULTS: The PTA belonged to Salas's lateral type and Saltzman's type 1. The supraorbital extradural approach allowed good visualization of the origin and the cavernous portion of the PTA through the infratrochlear triangle. Using the endonasal route, the cisternal portion of the PTA and its confluence to the basilar artery were demonstrated after opening the clival dura; however, the origin of the PTA and the cavernous portion of the PTA were not sufficiently exposed even using a direct approach to the cavernous sinus. The retrosigmoid approach revealed the anatomical relationship among the PTA, trigeminal nerve, and abducent nerve in the petroclival region. CONCLUSION: These 3 endoscopic approaches provided a superb image of the PTA and contribute to the anatomical comprehension of PTA. Additionally, these approaches make us more familiar with an endoscopic view of PTA.

Induction of MMP-2 at the interface between epithelial cells and fibroblasts from human periodontal ligament.

BACKGROUND AND OBJECTIVE: MMP-2 can degrade type IV collagen and MMP-14 can activate pro MMP-2. The present study was undertaken to examine the expression of MMP-2 and MMP-14 with respect to interaction between the cells of the epithelial rests of Malassez and fibroblasts from human periodontal ligament. MATERIAL AND METHODS: Explants of human periodontal ligament tissues produced outgrowths containing both putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts after incubation in a modified serum-free medium. The distribution and expression of MMP-2 and MMP-14 were analysed using immunohistochemistry, in situ hybridization and RT-PCR analysis. The conditioned media and cell extracts were collected for western blot analysis for MMP-2. RESULTS: Putative epithelial rests of Malassez cells at the interface between the cells of the epithelial rests of Malassez and fibroblasts expressed MMP-2 and MMP-14 strongly. However, in situ hybridization analysis revealed that human periodontal ligament fibroblasts expressed MMP-2 mRNA while putative epithelial rests of Malassez cells expressed MMP-14 mRNA at the interface. The RT-PCR analysis showed that the expression of MMP-2 mRNA was significantly higher when putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts were cultured together than when cultured alone. Western blot analysis showed that the active form of MMP-2 was detected at higher levels in the conditioned medium of the co-cultured cells. CONCLUSION: These findings indicate that putative epithelial rests of Malassez cells stimulate the production of MMP-2 in human periodontal ligament fibroblasts. Up-regulated proMMP-2 bound by MMP-14 expressed in epithelial rests of Malassez cells can degrade matrix molecules, such as type IV collagen, in the basal membrane between putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts.

The surface composition of asteroid 162173 Ryugu from Hayabusa2 near-infrared spectroscopy.

The near-Earth asteroid 162173 Ryugu, the target of the Hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. We report reflectance spectra of Ryugu's surface acquired with the Near-Infrared Spectrometer (NIRS3) on Hayabusa2, to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micrometers was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, which is consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.