Successful redo open thoracoabdominal aortic aneurysm surgery in a patient with vascular Ehlers-Danlos syndrome: A case report.

We report a case of a 63-year-old woman diagnosed with vascular Ehlers-Danlos syndrome (vEDS) who survived two prophylactic surgeries for the dilatation of a thoracoabdominal aortic aneurysm. She initially developed acute type B aortic dissection at the age of 44 years. Five years later, her dissected descending aorta was enlarged to 54 mm; thus, the descending aorta was replaced as the first surgery. Fortunately, the intra- and post-operative courses were uneventful. Fourteen years post her first surgery, the dissected thoracoabdominal aorta distal to the graft expanded to 53 mm; however, no anastomotic leakage was observed. Genetic testing revealed a COL3A1 abnormality, confirming the diagnosis of vEDS. Thoracoabdominal aorta replacement using deep hypothermia circulatory arrest was performed because of the high risk of aortic aneurysm rupture. The second surgery was performed without complications, and no complications were observed 13 months post-surgery. The major reason for a successful surgery in this patient was the relatively low vascular fragility associated with vEDS. This case demonstrates that there may be considerable individual differences in vascular fragility in patients with vEDS. Thus, surgical repair, along with endovascular therapy, might still be a beneficial option for patients with vEDS having large aortic aneurysms and a high risk of rupture. Learning objective: Prophylactic surgery for vascular lesions in Ehlers-Danlos syndrome (vEDS) is generally not recommended because of its high vascular fragility. However, if a patient with vEDS has an aortic aneurysm that is at a very high risk of rupture, aggressive treatment is a plausible option as there may be considerable individual differences in vascular fragility among patients with vEDS.

Prevalence of Human Adenovirus Type 3 Associated with Pharyngoconjunctival Fever in Children in Osaka, Japan during and after the COVID-19 Pandemic.

The incidence and type distribution of human adenovirus (HAdV) infections among children with pharyngoconjunctival fever (PCF) in Osaka, Japan between 2019 and 2023 were analyzed to assess the effect of the coronavirus disease 2019 (COVID-19) pandemic. The number of reported PCF cases in Osaka decreased from 2020 to 2022, followed by an unprecedented increase in 2023. HAdV-C strains, including types C1, C2, and C5, were detected in throughout the study period. Conversely, HAdV-B3 was not detected for 2 years and 9 months from March 2020 to December 2022, but the number of detections increased from July 2023. Overall, HAdV-B3 was the most frequently detected type (27 of 52 strains), and genetic analysis of its hexon hypervariable regions showed that, except for one strain, the HAdV-B3 strains identified after 2022 had different amino acid substitutions to those identified in 2019 and 2020. These results suggest that the PCF epidemic in 2023 was predominantly caused by variant strains of HAdV-B3, and that children were susceptible owing to a lack of exposure to HAdV-B3 between 2020 and 2022. Ongoing surveillance is needed to evaluate the impact of COVID-19 on the prevalence of HAdV infection.

Loxapine inhibits replication of hepatitis A virus in vitro and in vivo by targeting viral protein 2C.

No antiviral drugs currently are available for treatment of infection by hepatitis A virus (HAV), a causative agent of acute hepatitis, a potentially life-threatening disease. Chemical screening of a small-compound library using nanoluciferase-expressing HAV identified loxapine succinate, a selective dopamine receptor D2 antagonist, as a potent inhibitor of HAV propagation in vitro. Loxapine succinate did not inhibit viral entry nor internal ribosome entry site (IRES)-dependent translation, but exhibited strong inhibition of viral RNA replication. Blind passage of HAV in the presence of loxapine succinate resulted in the accumulation of viruses containing mutations in the 2C-encoding region, which contributed to resistance to loxapine succinate. Analysis of molecular dynamics simulations of the interaction between 2C and loxapine suggested that loxapine binds to the N-terminal region of 2C, and that resistant mutations impede these interactions. We further demonstrated that administration of loxapine succinate to HAV-infected Ifnar1-/- mice (which lack the type I interferon receptor) results in decreases in the levels of fecal HAV RNA and of intrahepatic HAV RNA at an early stage of infection. These findings suggest that HAV protein 2C is a potential target for antivirals, and provide novel insights into the development of drugs for the treatment of hepatitis A.

Effects of Counterion on the Formation and Hydration Behavior of α-Form Hydrated Crystals (α-Gels).

α-Form hydrated crystals form a lamellar gel in which the alkyl chains of the amphiphilic molecules are hexagonally arranged within bilayers below the gel-liquid crystal phase transition temperature. In practice, the lamellar gel network with excess water is called an "α-gel", particularly in the cosmetics industry. In this study, the hydration or water sorption of amphiphilic materials in water vapor was assessed using a humidity-controlled quartz crystal microbalance with dissipation monitoring (QCM-D) technique. The amphiphilic materials used in this study were hexadecyl phosphate salts neutralized with L-arginine (C16P-Arg), CsOH (C16P-Cs), KOH (C16P-K), and NaOH (C16P-Na). Small- and wide-angle X-ray scattering measurements revealed that C16P-Arg and C16P-Cs yielded α-form hydrated crystals. Humidity-controlled QCM-D measurements demonstrated that C16P-Arg and C16P-Cs more readily underwent hydration or water sorption than C16P-K and C16P-Na. The key conclusion is that the significant hydration ability of C16P-Arg and C16P-Cs promotes the formation of the corresponding α-form hydrated crystals.

Robot-assisted thoracic surgery versus video-assisted thoracic surgery for mediastinal lesions.

Background: Robot-assisted thoracic surgery (RATS) has become widely used for mediastinal procedures since 2018 when it was included in insurance coverage in Japan. Few studies have compared the surgical outcomes of RATS with the more established video-assisted thoracic surgery (VATS) approach to mediastinal surgery. We aimed to compare the perioperative outcomes of VATS and RATS to examine the advantages of the RATS approach in a single institutional cohort. Methods: A total of 144 patients who underwent VATS and 46 who underwent RATS mediastinal surgery between 2014 and 2022 were enrolled. We compared clinicopathological features such as age, sex, smoking history, respiratory function, surgical field, laterality, surgical procedure, board certification of the surgeon, and histology between the two groups. Perioperative outcomes including operation time, volume of blood lost, number of conversion cases to open surgery, duration of chest drainage, postoperative hospital stay, and postoperative complications were also reviewed. Results: The comparison of patient characteristics between the groups showed significant differences in median age (VATS, 52.5 years; RATS, 67.0 years; P=0.001), combined resection of surrounding tissues of the tumor (VATS, 2.1%; RATS, 10.9%; P=0.02), board certification of the surgeon (VATS, 53.5%; RATS, 100.0%; P<0.001), and histology (RATS group had a higher percentage of thymic epithelial tumors, P=0.01). Regarding perioperative outcomes, the median operation time was 120 min in the VATS group and 88 min in the RATS group, showing a significant difference (P=0.03). There were no significant differences in the volume of blood lost, incidence of conversion to open chest surgery, duration of chest drainage, postoperative length of stay in hospital, and incidence of perioperative complications. In the perioperative outcomes of cases operated on by board-certified surgeons, the median operation time (VATS, 117 min; RATS, 88 min; P=0.02) and median postoperative length of stay in hospital (VATS, 7 days; RATS, 6 days; P=0.001) showed significant differences, while other postoperative outcomes were not significantly different. Conclusions: RATS for mediastinal surgery is as safe as the VATS approach and may result in a shorter operative time and postoperative hospital stay. Further analysis of RATS for mediastinal surgery in a larger cohort is warranted.

[Robot-assisted Thoracic Surgery for Mediastinal Tumor].

In Japan, robot-assisted thoracic surgery (RATS) was introduced in thoracic surgery in 2001, but it did not become widespread. However, surgery for mediastinal tumors and lobectomy for lung cancer with RATS were covered by insurance in 2018 and are currently becoming popular as a general practice, following video-assisted thoracic surgery(VATS). Forty-six patients with mediastinal tumors were treated by RATS from February 2014 to November 2022 in our institution. Theoretically, the RATS approach is performed from one side in a semi-supine position under CO2 insufflation as with the VATS approach of our institution. In the case of extended thymectomy, a bilateral approach is performed by changing the patient's position. The median surgery time was 88 min, and the median surgery time in unilateral and bilateral approaches were 79 and 208 min, respectively. Blood loss during surgery was quite minimum, and no patients required conversion to VATS or thoracotomy. Regarding adverse events, postoperative bleeding was observed in one patient (2.2%). RATS has been successfully introduced and expanded safely for mediastinal tumors. Considering further expansion of RATS indications while conducting verification by comparison with VATS in the future is necessary.

Masitinib Inhibits Hepatitis A Virus Replication.

The hepatitis A virus (HAV) infection causes acute hepatitis. HAV also induces acute liver failure or acute-on-chronic liver failure; however, no potent anti-HAV drugs are currently available in clinical situations. For anti-HAV drug screening, more convenient and useful models that mimic HAV replication are needed. In the present study, we established HuhT7-HAV/Luc cells, which are HuhT7 cells stably expressing the HAV HM175-18f genotype IB subgenomic replicon RNA harboring the firefly luciferase gene. This system was made by using a PiggyBac-based gene transfer system that introduces nonviral transposon DNA into mammalian cells. Then, we investigated whether 1134 US Food and Drug Administration (FDA)-approved drugs exhibited in vitro anti-HAV activity. We further demonstrated that treatment with tyrosine kinase inhibitor masitinib significantly reduced both HAV HM175-18f genotype IB replication and HAV HA11-1299 genotype IIIA replication. Masitinib also significantly inhibited HAV HM175 internal ribosomal entry-site (IRES) activity. In conclusion, HuhT7-HAV/Luc cells are adequate for anti-HAV drug screening, and masitinib may be useful for the treatment of severe HAV infection.

CSNK2B modulates IRF1 binding to functional DNA elements and promotes basal and agonist-induced antiviral signaling.

Interferon regulatory factor 1 (IRF1) is a critical component of cell-intrinsic innate immunity that regulates both constitutive and induced antiviral defenses. Due to its short half-life, IRF1 function is generally considered to be regulated by its synthesis. However, how IRF1 activity is controlled post-translationally has remained poorly characterized. Here, we employed a proteomics approach to identify proteins interacting with IRF1, and found that CSNK2B, a regulatory subunit of casein kinase 2, interacts directly with IRF1 and constitutively modulates its transcriptional activity. Genome-wide CUT&RUN analysis of IRF1 binding loci revealed that CSNK2B acts generally to enhance the binding of IRF1 to chromatin, thereby enhancing transcription of key antiviral genes, such as PLAAT4 (also known as RARRES3/RIG1/TIG3). On the other hand, depleting CSNK2B triggered abnormal accumulation of IRF1 at AFAP1 loci, thereby down-regulating transcription of AFAP1, revealing contrary effects of CSNK2B on IRF1 binding at different loci. AFAP1 encodes an actin crosslinking factor that mediates Src activation. Importantly, CSNK2B was also found to mediate phosphorylation-dependent activation of AFAP1-Src signaling and exert suppressive effects against flaviviruses, including dengue virus. These findings reveal a previously unappreciated mode of IRF1 regulation and identify important effector genes mediating multiple cellular functions governed by CSNK2B and IRF1.

Shedding of rubella virus in postsymptomatic individuals; viral RNA load is a potential indicator to estimate candidate patients excreting infectious rubella virus.

BACKGROUND: Since the first isolation of rubella virus (RuV) in 1962, comprehensive data regarding the quantitative evaluation of RuV shedding remain unavailable. In this study, we evaluated the shedding of viral RNA and infectious virus in patients with acute RuV infection. STUDY DESIGN: We analyzed 767 specimens, including serum/plasma, peripheral blood mononuclear cells (PBMCs), throat swabs, and urine, obtained from 251 patients with rubella. The viral RNA load and the presence of infectious RuV were determined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and virus isolation. RESULTS: Virus excretion peaked 0-2 days after rash onset and decreased over time. The median viral RNA load dropped to an undetectable level on day 3 after rash onset in serum/plasma, day 2 in PBMCs, days 10-13 in throat swabs, and days 6-7 in urine. Infectious virus could be isolated for up to day 2 after rash onset in serum/plasma, day 1 in PBMCs, days 8-9 in throat swabs, and days 4-5 in urine. The minimum viral RNA load that allowed virus isolation was 961 copies/mL in serum/plasma, 784 copies/mL in PBMCs, 650 copies/mL in throat swabs, and 304 copies/mL in urine. A higher viral RNA load indicated a higher likelihood of the presence of infectious virus. CONCLUSION: These findings would contribute to improve algorithms for rubella surveillance and diagnosis. In addition, this study indicates that the results of RT-qPCR enable efficient rubella control by estimating candidate patients excreting infectious virus, which could help prevent viral transmission at an early stage and eliminate rubella ultimately.

Macrophage Depletion Reactivates Fecal Virus Shedding following Resolution of Acute Hepatitis A in Ifnar1-/- Mice.

Although hepatitis A virus (HAV) is associated only with acute hepatitis in humans, HAV RNA persists within the liver for months following resolution of liver inflammation and cessation of fecal virus shedding in chimpanzees and murine models of hepatitis A. Here, we confirm striking differences in the kinetics of HAV RNA clearance from liver versus serum and feces in infected Ifnar1-/- mice and investigate the nature of viral RNA persisting in the liver following normalization of serum alanine aminotransferase (ALT) levels. Fecal shedding of virus produced in hepatocytes declined >3,000-fold between its peak at day 14 and day 126, whereas intrahepatic HAV RNA declined only 32-fold by day 154. Viral RNA was identified within hepatocytes 3 to 4 months after inoculation and was associated with membranes, banding between 1.07 and 1.14 g/cm3 in isopycnic iodixanol gradients. Gradient fractions containing HAV RNA demonstrated no infectivity when inoculated into naive mice but contained neutralizing anti-HAV antibody. Depleting CD4+ or CD8+ T cells at this late point in infection had no effect on viral RNA abundance in the liver, whereas clodronate-liposome depletion of macrophages between days 110 and 120 postinoculation resulted in a striking recrudescence of fecal virus shedding and the reappearance of viral RNA in serum coupled with reductions in intra-hepatic Ifnγ, Tnfα, Ccl5, and other chemokine transcripts. Our data suggest that replication-competent HAV RNA persists for months within the liver in the presence of neutralizing antibody following resolution of acute hepatitis in Ifnar1-/- mice and that macrophages play a key role in viral control late in infection. IMPORTANCE HAV RNA persists in the liver of infected chimpanzees and interferon receptor-deficient Ifnar1-/- mice for many months after neutralizing antibodies appear, virus has been cleared from the blood, and fecal virus shedding has terminated. Here, we show this viral RNA is located within hepatocytes and that the depletion of macrophages months after the resolution of hepatic inflammation restores fecal virus shedding and circulating viral RNA. Our study identifies an important role for macrophages in virus control following resolution of acute hepatitis A in Ifnar1-/- mice and may have relevance to relapsing hepatitis A in humans.

Descending thoracic aortic repair outcomes for chronic aortic dissection: a single-centre experience.

OBJECTIVES: Thoracic endovascular aortic repair is a widely accepted treatment for chronic aortic dissection because of good early results compared to open surgical repair. We provide early and long-term results of descending thoracic aortic repair for chronic aortic dissection. METHODS: Patients who underwent descending thoracic aortic repair for chronic aortic dissection between January 2012 and December 2020 at Kawasaki Aortic Centre were included in this analysis. RESULTS: Four hundred ninety-two patients (median age, 64 years; interquartile range, 52-75 years) were included. The median duration of follow-up was 3.2 years (interquartile range, 1.5-5.2 years). The early mortality rate was 2.0% (n = 10); strokes occurred in 17 patients (3.5%); and spinal cord injuries occurred in 30 patients (6.1%). Early major adverse events including early death, stroke, spinal cord injury, tracheostomy and haemodialysis at the time of discharge occurred in 62 patients. Multivariable analysis indicated that age > 70 years and non-elective surgery were predictors of early major adverse events. Among patients without both risk factors (i.e. low-risk patients), 1 early death (0.4%), 3 strokes (1.5%) and 1 spinal cord injury (0.4%) were observed, 2 tracheostomies were performed (0.8%) and no patients required haemodialysis at the time of hospital discharge. The 5-year survival rate was 87.2%. The cumulative incidence of chronic aortic dissection-related aortic reintervention at 5 years was 7.9%. CONCLUSIONS: Descending thoracic aortic repair for chronic aortic dissection resulted in good early and long-term results, and it can serve as the gold standard for low-risk patients.

Novel flavonoid hybrids as potent antiviral agents against hepatitis A: Design, synthesis and biological evaluation.

Two series of flavonoid hybrids, totaling 42 compounds, were designed, synthesized and evaluated to develop antiviral compounds effective against hepatitis A virus (HAV). A recombinant viral screening system revealed that most of the synthesized derivatives exhibited significant anti-HAV activity, and compounds B2, B3, B5 and B27 were identified as potential inhibitors of HAV. Post-treatment of cells with B2, B3, B5 and B27 after HAV infection strongly suppressed HAV infection, whereas pretreatment or simultaneous treatment were ineffective. Furthermore, these four compounds significantly inhibited HAV (HM175/18f strain) production in a dose-dependent manner. Analyses using HAV subgenomic replicon systems indicated that these compounds specifically inhibit HAV RNA replication. More importantly, the most potent compounds B2 and B27 also showed clear inhibitory effects on two other HAV strains, KRM031 and TKM005, which also isolated from clinical patients. Our study is the first to report these newly designed flavonoid hybrids as lead compounds for the development of novel anti-HAV drugs.

IRF3-mediated pathogenicity in a murine model of human hepatitis A.

HAV-infected Ifnar1-/- mice recapitulate many of the cardinal features of hepatitis A in humans, including serum alanine aminotransferase (ALT) elevation, hepatocellular apoptosis, and liver inflammation. Previous studies implicate MAVS-IRF3 signaling in pathogenesis, but leave unresolved the role of IRF3-mediated transcription versus the non-transcriptional, pro-apoptotic activity of ubiquitylated IRF3. Here, we compare the intrahepatic transcriptomes of infected versus naïve Mavs-/- and Ifnar1-/- mice using high-throughput sequencing, and identify IRF3-mediated transcriptional responses associated with hepatocyte apoptosis and liver inflammation. Infection was transcriptionally silent in Mavs-/- mice, in which HAV replicates robustly within the liver without inducing inflammation or hepatocellular apoptosis. By contrast, infection resulted in the upregulation of hundreds of genes in Ifnar1-/- mice that develop acute hepatitis closely modeling human disease. Upregulated genes included pattern recognition receptors, interferons, chemokines, cytokines and other interferon-stimulated genes. Compared with Ifnar1-/- mice, HAV-induced inflammation was markedly attenuated and there were few apoptotic hepatocytes in livers of infected Irf3S1/S1Ifnar1-/- mice in which IRF3 is transcriptionally-inactive due to alanine substitutions at Ser-388 and Ser-390. Although transcriptome profiling revealed remarkably similar sets of genes induced in Irf3S1/S1Ifnar1-/- and Ifnar1-/- mice, a subset of genes was differentially expressed in relation to the severity of the liver injury. Prominent among these were both type 1 and type III interferons and interferon-responsive genes associated previously with apoptosis, including multiple members of the ISG12 and 2'-5' oligoadenylate synthetase families. Ifnl3 and Ifnl2 transcript abundance correlated strongly with disease severity, but mice with dual type 1 and type III interferon receptor deficiency remained fully susceptible to liver injury. Collectively, our data show that IRF3-mediated transcription is required for HAV-induced liver injury in mice and identify key IRF3-responsive genes associated with pathogenicity, providing a clear distinction from the transcription-independent role of IRF3 in liver injury following binge exposure to alcohol.

Evaluation of overall and disease-free survival in patients with free flaps for oral cancer resection.

PURPOSE: Sarcopenia is characterized by depletion of skeletal muscle mass (SMM) and can cause increased postoperative complication in free flap procedure. One of the most important considerations while deciding the indication of the procedure is patients' survival. This study aimed to verify the relationship between low SMM and survival in patients who undergo oral cancer resection using free flap. METHODS: SMM was evaluated using the skeletal muscle index (SMI cm2 /m2 ), which was defined using cross-sectional areas of skeletal muscles on computed tomography at the level of the third lumbar vertebrae normalized for height. Overall, 111 patients who underwent primary oral cancer resection and free flaps were included. Multivariate Cox regression analyses were used to evaluate the prognostic factors for survival. RESULTS: A total of 25 patients (22.5%) were diagnosed with low SMM. The mean SMI was 42.2 cm2 /m2 . Multivariable analyses showed that increased age (hazard ratio [HR]; 4.98, p = .004), infiltrative growth pattern INF-c (HR; 3.83, p = .037), and low SMM (HR; 2.59, p = .034) were significant negative prognostic factors for overall survival. Increased age (HR; 3.18, p = .005), extra-nodal extension (HR; 3.30, p = .001), and low SMM (HR; 2.42, p = .017) were significant negative prognostic factors for disease-free survival. CONCLUSIONS: Low SMM is a significant negative prognostic factor for overall and disease-free survival in oral cancer patients undergoing free flap. Future prospective studies are warranted to identify effective preoperative exercise and nutrition programs to improve low skeletal muscle and survival rate in patients undergoing free flap procedures.

Novel human reovirus isolated from children and its long-term circulation with reassortments.

Mammalian orthoreovirus (MRV), also known as reovirus, was discovered in the 1950s and became the first reported segmented double-stranded RNA virus. MRVs have since been found in a variety of animal species, including humans. However, reports on MRV infections are scarce due to the rarity of their symptomatic occurrence. In Japanese surveillance studies, MRVs have been detected as gastrointestinal pathogens since 1981, with a total of 135 records. In Osaka City, Japan, MRV was first isolated in 1994 from a child with meningitis, and then in 2005 and 2014 from children with gastroenteritis. Here, we conducted the first molecular characterization of human MRV isolates from Japan and identified a novel human reovirus strain belonging to MRV type 2, designated the MRV-2 Osaka strain. This strain, with all three isolates classified, is closely related to MRV-2 isolates from sewage in Taiwan and is relatively close to an MRV-2 isolate from a bat in China. Our data suggest that the MRV-2 Osaka strain, which has circulated amongst humans in Japan for at least two decades, has spread internationally.

Dengue Virus Type 1 Infection in Traveler Returning from Tanzania to Japan, 2019.

The largest outbreak of dengue fever in Tanzania is ongoing. Dengue virus type 1 was diagnosed in a traveler who returned from Tanzania to Japan. In phylogenetic analysis, the detected strain was close to the Singapore 2015 strain, providing a valuable clue for investigating the dengue outbreak in Tanzania.

An Epidemic of Hand, Foot, and Mouth Disease Caused by Coxsackievirus A6 in Osaka City, Japan, in 2017.

The second largest epidemic of hand, foot, and mouth disease since 1982 occurred in 2017, which involved 6,173 cases in Osaka City, Japan. The main causative agent was coxsackievirus A6 (CV-A6). Phylogenetic analysis revealed that the detected CV-A6 strains belonged to genetic groups A3 and A4 in clade A.

Basal expression of interferon regulatory factor 1 drives intrinsic hepatocyte resistance to multiple RNA viruses.

Current models of cell-intrinsic immunity to RNA viruses centre on virus-triggered inducible antiviral responses initiated by RIG-I-like receptors or Toll-like receptors that sense pathogen-associated molecular patterns, and signal downstream through interferon regulatory factors (IRFs), transcription factors that induce synthesis of type I and type III interferons1. RNA viruses have evolved sophisticated strategies to disrupt these signalling pathways and evade elimination by cells, attesting to their importance2. Less attention has been paid to how IRFs maintain basal levels of protection against viruses. Here, we depleted antiviral factors linked to RIG-I-like receptor and Toll-like receptor signalling to map critical host pathways restricting positive-strand RNA virus replication in immortalized hepatocytes and identified an unexpected role for IRF1. We show that constitutively expressed IRF1 acts independently of mitochondrial antiviral signalling (MAVS) protein, IRF3 and signal transducer and activator of transcription 1 (STAT1)-dependent signalling to provide intrinsic antiviral protection in actinomycin D-treated cells. IRF1 localizes to the nucleus, where it maintains the basal transcription of a suite of antiviral genes that protect against multiple pathogenic RNA viruses, including hepatitis A and C viruses, dengue virus and Zika virus. Our findings reveal an unappreciated layer of hepatocyte-intrinsic immunity to these positive-strand RNA viruses and identify previously unrecognized antiviral effector genes.

Characterizing Water Behavior in α-Gel (α-Type Hydrated Crystal) Formed from Monohexadecyl Phosphate and L-Arginine.

Monohexadecyl phosphate, neutralized by L-arginine (C16MP-Arg), forms an α-gel (α-type hydrated crystal) with water. In this study, we characterized the behavior of water in the C16MP-Arg α-gel system by means of small/wide angle X-ray scattering (SWAXS), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and 1H nuclear magnetic resonance (NMR) spectroscopy. An increased water concentration resulted in an increase in the d-spacing of the lamellar bilayers as well as an increased wavenumber for the O-H stretching vibration peak. In addition, the melting enthalpy increased with increasing water concentration, while freezing was not observed below a water concentration of 20 wt%. These results suggest that the overall properties of water changed as a function of its concentration in the sample. 1H-NMR spin-spin relaxation time (T2) measurements further suggest that the protons of water and C16MP-Arg can be classified into three components (low-, middle-, and high-T2 components) as a function of the temperature and concentration. The low-T2 component mainly arose from the protons of C16MP-Arg alkyl chains, and its mobility increased with increasing temperature. The high-T2 component arose from the protons of water. The water behaved as "bound water" for the C16MP-Arg headgroups at -30°C and a water concentration of 20 wt%, and the mobility increased with increasing temperature and water concentration. These changes suggest that an increased water concentration results in an increased amount of water being incorporated between the C16MP-Arg lamellar bilayers as well as in spaces surrounded by α-gel domains.