Prevalence of antimicrobial-resistant Cutibacterium isolates and development of multiplex PCR method for Cutibacterium species identification.

INTRODUCTION: Cutibacterium species such as C. acnes, C. avidum, and C. granulosum are known anaerobic skin inhabitants and often cause surgical site infections. These species are genetically similar and are difficult to identify rapidly. In addition, their pathogenicity and antimicrobial resistance remain unknown. In this study, antimicrobial resistance in Cutibacterium isolates was studied and a multiplex PCR method for their identification was developed. METHODS: A total of 497 C. acnes, 71 C. avidum, and 25 C. granulosum strains which were isolated from the acne pustule and infectious regions, were used. RESULTS: The antimicrobial resistance rates of C. acnes, C. avidum, and C. granulosum strains isolated from patients with acne vulgaris were higher than those of strains isolated from patients with infectious diseases. In particular, macrolide-clindamycin-resistant strains were isolated most frequently from all species. Among the resistant strains, strains with 23S rRNA mutations were the most common in C. acnes (24.3%, 71/292), whereas C. avidum and C. granulosum strains were most frequently found with erm(X). For the first time, a C. granulosum strain carrying pTZC1, which codes erm(50) and tet(W), was isolated from patients with acne vulgaris. Regarding the rapid identification of causative pathogens from infectious regions, three Cutibacterium species were identified with 100% sensitivity and specificity using multiplex PCR method. CONCLUSIONS: Our data showed that antimicrobial resistance differed among Cutibacterium species. The multiplex PCR method may contribute to the rapid detection of Cutibacterium species and selection of appropriate antimicrobial agents.

High-Level Quinolone-Resistant Haemophilus haemolyticus in Pediatric Patient with No History of Quinolone Exposure.

The prevalence of antimicrobial resistance among Haemophilus spp. is a critical concern, but high-level quinolone-resistant strains had not been isolated from children. We isolated high-level quinolone-resistant H. haemolyticus from the suction sputum of a 9-year-old patient. The patient had received home medical care with mechanical ventilation for 2 years and had not been exposed to any quinolones for >3 years. The H. haemolyticus strain we isolated, 2019-19, shared biochemical features with H. influenzae. However, whole-genome analysis found this strain was closer to H. haemolyticus. Phylogenetic and mass spectrometry analyses indicated that strain 2019-19 was in the same cluster as H. haemolyticus. Comparison of quinolone resistance-determining regions showed strain 2019-19 possessed various amino acid substitutions, including those associated with quinolone resistance. This report highlights the existence of high-level quinolone-resistant Haemophilus species that have been isolated from both adults and children.

A multicenter, double-blind, randomized, parallel-group, placebo-controlled study to evaluate the efficacy and safety of camostat mesilate in patients with COVID-19 (CANDLE study).

BACKGROUND: In vitro drug screening studies have indicated that camostat mesilate (FOY-305) may prevent SARS-CoV-2 infection into human airway epithelial cells. This study was conducted to investigate whether camostat mesilate is an effective treatment for SARS-CoV-2 infection (COVID-19). METHODS: This was a multicenter, double-blind, randomized, parallel-group, placebo-controlled study. Patients were enrolled if they were admitted to a hospital within 5 days of onset of COVID-19 symptoms or within 5 days of a positive test for asymptomatic patients. Severe cases (e.g., those requiring oxygenation/ventilation) were excluded. Patients were enrolled, randomized, and allocated to each group using an interactive web response system. Randomization was performed using a minimization method with the factors medical institution, age, and underlying diseases (chronic respiratory disease, chronic kidney disease, diabetes mellitus, hypertension, cardiovascular diseases, and obesity). The patients, investigators/subinvestigators, study coordinators, and other study personnel were blinded throughout the study. Patients were administered camostat mesilate (600 mg qid; four to eight times higher than the clinical doses in Japan) or placebo for up to 14 days. The primary efficacy endpoint was the time to the first two consecutive negative tests for SARS-CoV-2. RESULTS: One-hundred fifty-five patients were randomized to receive camostat mesilate (n = 78) or placebo (n = 77). The median time to the first test was 11.0 days (95% confidence interval [CI]: 9.0-12.0) in the camostat mesilate group and 11.0 days (95% CI: 10.0-13.0) in the placebo group. Conversion to negative viral status by day 14 was observed in 45 of 74 patients (60.8%) in the camostat mesilate group and 47 of 74 patients (63.5%) in the placebo group. The primary (Bayesian) and secondary (frequentist) analyses found no significant differences in the primary endpoint between the two groups. No additional safety concerns beyond those already known for camostat mesilate were identified. CONCLUSIONS: Camostat mesilate did not substantially reduce the time to viral clearance, based on upper airway viral loads, compared with placebo for treating patients with mild to moderate SARS-CoV-2 infection with or without symptoms. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04657497. Japan Registry for Clinical Trials, jRCT2031200198.

A New Concept for an Adhesive Material Inspired by Clingfish Sucker Nanofilaments.

Underwater adhesive materials are in high demand in various fields, and fish species with sucker disks have attracted attention due to their superior performance and interesting structures. The clingfish, in particular, is widely known for using hierarchical sucker disk structures to demonstrate rapid and strong adhesion to rocky surfaces under strong currents. We examined the combination of nanofilaments and mucus in the clingfish sucker disk. Nanofilaments reinforce mucus adhesion force by reducing the compliance without affecting the contact area. We prepared structures from hard polymers and soft polydimethylsiloxane (PDMS) that mimicked clingfish sucker nanofilaments and mucus, with these biomimetic structures showing significant adhesion force underwater. Furthermore, the hardness and length of the nanofilaments and Young's modulus and thickness of the mucus-mimicking PDMS layer had critical effects on the adhesion force. According to the results, clingfish nanofilaments act as hard bracing for the soft mucus, and the structural combination of the conflicting characteristics of hardness and softness, thus achieved, is crucial for strong adhesion.

Asymptomatic latent syphilis in geriatric patients in association with stoke: Analysis using routine syphilis tests.

INTRODUCTION: We investigated the association between stroke and asymptomatic latent syphilis (ALS) in geriatric patients. METHODS: This retrospective observational study included patients aged >65 years who underwent routine qualitative rapid plasma reagin (RPR) and Treponema pallidum Latex Agglutination (TPLA) tests at a 161-bed community acute care hospital with long-term care facilities in Kamakura, Japan, from August 2014 to February 2019. Asymptomatic patients with a positive TPLA test result were diagnosed with ALS. Ninety-six patients with ALS were included in the study. Fifty-one patients (53.1%) had a positive RPR test. Comorbidities included hypertension (n = 44; 45.8%), chronic kidney disease (n = 44; 45.8%), and fracture (n = 29; 30.2%). No significant differences were found in sex, age, or comorbidities in univariate analyses. Multivariate analysis of the TPLA-positive geriatric patients revealed that a positive RPR test (odds ratio = 9.06; 95% confidence interval = 1.69-48.5; p = 0.01) was associated with a history of stroke. CONCLUSIONS: For geriatric patients with ALS, a positive qualitative RPR test was associated with a history of stroke. Medical evaluation and management of the risk factors for stroke are more necessary for ALS with a positive RPR qualitative test.

A case of Shewanella algae-induced bacteremia in Japan: Case report and literature review.

Shewanella algae (S. algae) is a rare bacterium that causes infectious diseases in humans. Herein, we present a case of an 84-year-old man with S. algae-induced bacteremia and performed a review of 12 cases identified via a literature search and this case. Literature review of previous reports in Japan have revealed that 69.2% of patients with S. algae-induced bacteremia had a history of contact with fresh fish. Appropriate interviews of patients, especially in the hot season, and the accurate identification of the causative bacterium, by using techniques such as MALDI-TOF-MS and genetic testing, are necessary if S. algae or other bacteria from the genus Shewanella are detected in blood-culture tests.

Cutibacterium acnes phylogenetic type IC and II isolated from patients with non-acne diseases exhibit high-level biofilm formation.

Cutibacterium (formerly Propionibacterium) acnes is an important for not only exacerbating factor of acne vulgaris but also pathogen of surgical site infections (SSIs) in orthopedics and plastic surgery. Although biofilm-forming (BF) C. acnes are associated with intractable SSI, characteristics of these strains were still unknown. Here, we explored detailed molecular epidemiological features of BF C. acnes isolated as causative pathogen of infectious diseases. Phylogenetic types of 205 C. acnes strains isolated between 2013 and 2018 from 18 clinical departments of a university hospital in Japan were determined by single-locus sequence type (SLST). Clade H (traditional type IC) and K (type II) which are less relevant with healthy skin and acne vulgaris, were detected in 26.8% (55/205) and 16.1% (33/205) of the strains, respectively. The incidence of them was significantly higher than that of acne patients (H and K, each 2.9%, P < 0.05). In addition, SLST distribution of C. acnes strains differed by each department and isolation site. When biofilm formation was quantified, 51 strains (24.9%) were defined as high-BF strains. Notably, most high-BF strains were classified into the strains of clade H (56.4%, 31/55) and clade K (54.4%, 18/33), and these strains were frequently found in the strains isolated from patients of medical emergency center and plastic surgery. Similarly, high-BF strains were frequently found among the isolates from blood (35.7%) and catheters (30.0%), with a high proportion belonging to clades H and K. Compared to C. acnes strains isolated from acne patients, antimicrobial-resistant strains were less identified in non-acne patients. Our findings showed that pathogenicity of C. acnes strains differs by their phylogenetic types. Furthermore, we showed clade H and K have the ability of high biofilm formation and suggest that these strains have potential to become a risk factor for SSI.

Effect of the Microstructures on Vulcanized Rubber Frictions.

Vulcanized rubber is widely used in a wide range of applications because of its flexibility, durability, sealing properties, and high degree of friction. However, this high degree of friction can also become an issue, as it leads to the wearing and breakage of parts. In this report, we investigated the effects of the vulcanized rubber microstructures on friction force by using simple, anisotropic microstructures. The line and space master microstructures were prepared from a photoresist, and the structures were transferred to PDMS, PSt, and then Ni. After surface modification of the Ni microstructures by TEOS, the vulcanized rubber microstructures were fabricated by a simple hot press process with the TEOS-coated Ni microstructure molds. The structural parameters of the vulcanized rubber line and space microstructures were found to be successfully varied by elongation, and the structural deformations were also investigated by FEM simulations. Measurements of the frictional force of the vulcanized rubber microstructures revealed the friction coefficient was reduced by the surface microstructures and was affected by the directions of the contact because of the microstructure anisotropy. The reason for of these results can be explained by the changes in the contact area and hysteresis friction. These results suggest that the friction coefficients of vulcanized rubbers can be reduced by the simple surface microstructures that are applicable to a wide range of fields.

Dissemination of quinolone low-susceptible Haemophilus influenzae ST422 in Tokyo, Japan.

INTRODUCTION: Haemophilus influenzae with a reduced susceptibility to quinolones (quinolone low-susceptible H. influenzae) has recently emerged in Japan. In addition, the regional outbreak of the quinolone low-susceptible H. influenzae ST422 clone has been reported. In this study, we isolated this clone from an acute care hospital located in a geographically different area from the previous outbreak and characterised the nature of this clone. METHODS: Eighty-nine H. influenzae isolated between 2017 and 2019 were tested. The antimicrobial susceptibility was determined by the broth dilution method. The genetic background was analysed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Growth ability and ß-lactamase acquisition were evaluated by growth curve analysis and conjugative transfer experiments, respectively. RESULTS: Quinolone low-susceptible isolates accounted for 4.2% (1/24) in 2018 and 13.9% (5/36) in 2019. Most of the quinolone low-susceptible strains (83.3%) were classified as ST422 and had amino acid substitutions in quinolone resistance-determining regions in both GyrA and ParC. The patients' backgrounds were highly diverse. In addition, these isolates showed the same PFGE pattern as outbreak strains. The growth of ST422 clone was relatively faster than other clones. Furthermore, ST422 clone was able to acquire ß-lactamase from a ß-lactamase positive strain by horizontal transfer, becoming highly resistant to ß-lactams. CONCLUSION: Our study indicated that the quinolone low-susceptible H. influenzae ST422 clone has been spreading in the community undetected. In addition, this clone has the potential to grow faster and become more resistant through exogenous gene transfer. Therefore, ST422 clone should be monitored attention throughout Japan.

Arthritis Caused by MRSA CC398 in a Patient without Animal Contact, Japan.

Clonal complex 398 methicillin-resistant Staphylococcus aureus (MRSA) is a typical lineage of livestock-associated MRSA. We report a case of intractable arthritis of the shoulder joint caused by a multidrug-resistant Panton-Valentine leukocidin-positive livestock-associated MRSA clonal complex 398 sequence type 1232 clone in a patient in Japan who had no animal contact.

Breakthrough Exophiala dermatitidis infection during prophylactic administration of micafungin during second umbilical cord blood transplantation after graft failure.

Exophiala dermatitidis infections in patients with hematological malignancies are very rare. Our patient had a blood stream infection caused by E. dermatitidis following the second umbilical cord blood transplantation (UCBT) after graft failure during the first UCBT. To our knowledge, this is the first report describing a breakthrough fungal infection caused by E. dermatitidis during the prophylactic administration of micafungin (MCFG). Therefore, MCFG-treated patients should be monitored for breakthrough E. dermatitidis infection during hematopoietic stem cell transplantation.

Therapeutic effect of autologous compact bone-derived mesenchymal stem cell transplantation on prion disease.

Prion diseases are fatal neurodegenerative disorders of humans and animals and no effective treatments are currently available. Allogenic transplantation of immortalized human mesenchymal stem cells (MSCs) can prolong the survival of mice infected with prions. However, autologous transplantation is an appropriate model for evaluating the effects of MSCs on prion diseases. Therefore, we isolated and purified MSCs from the femur and tibia of mice as compact bone-derived MSCs (CB-MSCs). Flow cytometric analysis showed that CB-MSCs were negative for myeloid stem cell-derived cell markers CD11b and CD45, but positive for molecules such as Sca-1, CD105 and CD90.2, which are reported to be expressed on MSCs. The ability of CB-MSCs to migrate to brain extracts from prion-infected mice was confirmed by an in vitro migration assay. Intra-hippocampus transplantation of CB-MSCs at 120 days post-inoculation marginally but significantly prolonged the survival of mice infected with the Chandler prion strain. The transplantation of CB-MSCs did not influence the accumulation of disease-specific prion protein. However, the CB-MSC transplantation enhanced microglial activation, which appeared to be polarized to the M2-type activation state. These results suggest that autologous MSC transplantation is a possible treatment for prion diseases, while the modification of microglial activation may be a therapeutic target for neurodegenerative diseases.

Pulmonary Histoplasmosis in a Japanese Man Infected During Travel to Mexico and Management of His Wife's Condition: A Case Report.

We report herein on the case of a 33-year-old Japanese man in whom an abnormal shadow was detected on chest radiography during a medical checkup after a 1-year-stay in Mexico. Chest computed tomography showed a nodule in the left lower lobe adjacent to the visceral pleura. Histopathologic examination of a thoracoscopic partial pulmonary resection specimen showed coagulation necrosis with a number of yeast-like forms on Grocott staining. In addition, serum anti-Histoplasma antibody positivity was detected with an enzyme-linked immunosorbent assay, and Histoplasma-specific nested real-time polymerase chain reaction results were positive in the pulmonary region. Finally, pulmonary histoplasmosis was diagnosed, and treatment with itraconazole was initiated. The patient's wife who had accompanied him to Mexico was asymptomatic and was not found to have histoplasmosis based on diagnostic imaging and serological findings. Although rare in Japan, histoplasmosis should be considered in the differential diagnosis of pulmonary lesions in patients who have returned from travel to endemic areas.

Candidemia Diagnosed from Peripheral Blood Smear: Case Report and Review of Literature 1954-2013.

BACKGROUND: Yeast with pseudohyphae or those that have been phagocytized by white blood cells are coincidentally found in peripheral blood smears. The clinical diagnostic value and outcome of candidaemia diagnosed from peripheral blood smears (CPBSs) are unclear. CASE PRESENTATION: A 45-year-old man with diabetes and panhypopituitarism for 20 years received 10 mg of hydrocortisone and 100 µg of levothyroxine sodium hydrate daily. He has been admitted seven times because of adrenal failure triggered by infections and was admitted for pneumonia. On day 56, some budding yeast was found microscopically in a peripheral blood smear with May-Giemsa staining. Some of them were phagocytized by white blood cells. The two blood cultures yielded Candida parapsilosis. Despite antifungal treatment and removal of an intravenous catheter, on day 98 (42 days after the candidaemia diagnosis), the patient died. CONCLUSION: We analysed 36 cases including the present case. Almost all CPBS patients (96.5 %, n = 29) were using an intravenous catheter. The most frequently isolated species was C. parapsilosis (35.1 %), followed by C. albicans (29.7 %). The overall mortality rate was 53.6 % (n = 28). The time from the discovery of yeast-like pathogens using peripheral blood smears to death ranged from a few hours to 93 days (median 19 days). The present results suggest that intravenous catheter use and the underlying conditions of patients are responsible for CPBSs. The detection of yeast in peripheral blood smears suggests advanced infections with uncontrollable complications, which means a poor prognosis. Rapid detection methods besides blood culture are needed.

Edwardsiella tarda bacteremia. A rare but fatal water- and foodborne infection: Review of the literature and clinical cases from a single centre.

BACKGROUND: Edwardsiella tarda bacteremia (ETB) can be a fatal disease in humans. OBJECTIVES: To determine the significant risk factors associated with death caused by ETB, and to examine the geographical, seasonal, environmental and dietary factors of the disease. METHODS: A retrospective, observational, case control study was performed. The PubMed MEDLINE and Japanese Medical Abstract Society (www.jamas.or.jp) databases were searched for ETB case reports and meeting abstracts. In additon, retrospective chart reviews of patients with ETB at the Tokyo Women's Medical University Hospital (Tokyo, Japan) were conducted to evaluate the risk factors associated with death using multivariate analyses. RESULTS: The literature search yielded 46 publications, comprising 72 cases from the English (n=30), French (n=1), Spanish (n=1) and Japanese (n=14) literature. Five cases at the Tokyo Women's Medical University Hospital were also included. Of the included 77 cases, the mean age was 61 years and 39% of patients were female; 77.2% of the cases occurred between June and November, and 45.5% were reported in Japan. Dietary factors (raw fish/meat exposure) were reported for 10.4% of patients and 12.9% reported environmental (ie, brackish water) exposure. The overall mortality rate was 44.6%; however, this rate increased to 61.1% for ETB patients with soft tissue infections. Liver cirrhosis was determined to be an independent risk factor associated with death (OR 12.0 [95% CI 2.46 to 58.6]; P=0.00213) using multivariate analyses. DISCUSSION: To our knowledge, the present analysis was the first and largest multi-language review of ETB. Clinical characteristics of ETB resemble those of Aeromonas, typhoid fever and Vibrio vulnificus infections, in addition to sharing similar risk factors. CONCLUSION: ETB should be categorized as a severe food- and waterborne infection, which results in high mortality for patients with liver cirrhosis.

HISTORIQUE: Chez les humains, la bactériémie à Edwardsiella tarda (BET) peut être mortelle. OBJECTIFS: Déterminer les facteurs de risque importants liés aux décès causés par la BET et examiner les facteurs géographiques, saisonniers, environnementaux et diététiques de la maladie. MÉTHODOLOGIE: Les chercheurs ont effectué une étude castémoins d'observation rétrospective. Ils ont fait des recherches dans les bases de données MEDLINE de PubMed et de la Société japonaise de communications médicales (www.jamas.or.jp) pour trouver les comptes rendus de BET et les communications de cas lors de colloques et congrès. Ils ont également procédé à une analyse rétrospective des dossiers de patients atteints d'une BET à l'hôpital universitaire de Tokyo pour femmes, au Japon, pour évaluer les facteurs de risque liés aux décès à l'aide d'analyses multivariées. RÉSULTATS: L'analyse bibliographique a permis d'extraire 46 publications, soit 72 cas tirés de publications anglophones (n=30), francophones (n=1), espagnoles (n=1) et japonaises (n=14). Cinq cas de l'hôpital universitaire de Tokyo pour femmes étaient également inclus. Les 77 cas avaient un âge moyen de 61 ans, et 39 % étaient de sexe féminin, 77,2 % s'étaient déclarés entre les mois de juin et novembre et 45,5 % provenaient du Japon. Chez 10,4 % des patients, des facteurs diététiques (poisson cru, exposition à la viande) étaient en cause, tandis que 12,9 % présentaient une exposition environnementale (eau saumâtre). Le taux de mortalité globale s'élevait à 44,6 %, mais passait à 61,1 % chez les patients atteints d'une BET et d'infections des tissus mous. D'après les analyses multivariées, la cirrhose était un facteur de risque indépendant de décès (RC 12,0 [95 % IC 2,46 à 58,6]; P=0,00213). EXPOSÉ: En autant que nous le sachions, il s'agissait de la plus vaste analyse sur la BET et de la première à être multilingue. Les caractéris-tiques cliniques de la BET ressemblent à celles des infections à Aeromonas et à Vibrio vulnificus et de la typhoïde en plus de partager des facteurs de risque similaires. CONCLUSION: La BET devrait être classée parmi les graves infections d'origine hydrique et alimentaire qui entraînent des taux de mortalité élevés chez les patients atteints d'une cirrhose.

Fournier's gangrene caused by Listeria monocytogenes as the primary organism.

A 70-year-old man with a history of tongue cancer presented with Fournier's gangrene caused by Listeria monocytogenes serotype 4b. Surgical debridement revealed undiagnosed rectal adenocarcinoma. The patient did not have an apparent dietary or travel history but reported daily consumption of sashimi (raw fish). Old age and immunodeficiency due to rectal adenocarcinoma may have supported the direct invasion of L monocytogenes from the tumour. The present article describes the first reported case of Fournier's gangrene caused by L monocytogenes. The authors suggest that raw ready-to-eat seafood consumption be recognized as a risk factor for listeriosis, especially in cases of skin and soft tissue infection.

Un homme de 70 ans ayant des antécédents de cancer de la langue s'est présenté avec une gangrène de Fournier causée par un Listeria monocytogenes de sérotype 4b. Le débridement chirurgical a révélé un adénocarcinome rectal non diagnostiqué. Le patient n'avait pas d'antécédents alimentaires ou de voyage apparents, mais a déclaré consommer des sashimis (poisson cru) tous les jours.L'âge avancé et l'immunodéficience causée par l'adénocarcinome rectal ont peut-être favorisé l'invasion directe du L monocytogenes par la tumeur. Il s'agit du premier cas déclaré de gangrène de Fournier attribuable au L monocytogenes. Les auteurs proposent d'inclure la consommation de fruits de mer crus prêt-à-manger dans les facteurs de risque de listériose, notamment en cas d'infections de la peau et des tissus mous.

Cefazolin therapy for methicillin-susceptible Staphylococcus aureus bacteremia in Japan.

This is a retrospective cohort study of patients who were treated with cefazolin for methicillin-susceptible Staphylococcus aureus bacteremia, at Tokyo Women's Medical University Hospital between January 2006 and December 2010. During the study period, 84/140 (60%) patients received cefazolin (mean age, 54 years; range, 0-94 years, male patients 64%). Of these, 60/84 (71%) cases were hospital acquired infections, 55/84 (65%) had heart disease, and 19/84 (23%) had moderate to severe heart failure (New York Heart Association class III/IV). The treatment failure rate at 12 weeks was 35% (n = 29). All-cause mortality were 15% (n = 13) after 12 weeks and 21% (n = 18) after a year. Secondary endocarditis and neurological events were observed in 10% (n = 8) and 2% (n = 2). Moderate to severe heart failure and retained intravascular devices were associated with treatment failure at 12 weeks by multivariate analysis (P < 0.01, P = 0.018). Our results suggest that hospital-acquired methicillin-susceptible S. aureus bacteremia can cause severe complications in patients with moderate to severe heart failure who retain their intravascular devices. Both effective antimicrobial therapy and removal of infected foci are essential for S. aureus bacteremia treatments.

Serum uric acid is associated with the left ventricular mass index in males of a general population.

The association of serum uric acid (UA) with left ventricular hypertrophy (LVH) remains controversial. We investigated this issue in a general population. Participants consisted of 1,943 subjects (774 males and 1,169 females) aged over 40 years, living in Tanushimaru (a Japanese cohort of the Seven Countries Study). Serum UA and other biochemistry parameters were determined by a standard analytical technique. All individuals underwent anthropometric measurements and 2-dimensional echocardiography. Because serum UA levels are much higher in males than in females, they were analyzed separately. When LV mass index (LVMI) levels were stratified according to tertile as low (≤ 80 cm(2): n = 261), middle (81-103 cm(2): n = 261), and high (≥ 104 cm(2): n = 252) in males, there were significant relationships between LVMI and UA, in addition to age, body mass index, systolic blood pressure, medication for hypertension, triglycerides, and alcohol intake. Multiple stepwise regression analysis revealed LVMI was significantly associated with systolic BP (P < 0.0001), medication for hypertension (P < 0.0001), UA (P = 0.003), BMI (P = 0.019), and alcohol intake (P = 0.038) in males. In females, LVMI was not associated with UA. In a multiple logistic regression analysis, a significantly higher odds ratio of LVH (odds ratio: 1.77, 95%CI: 1.01-3.09, P < 0.05) was observed for males in the highest UA tertile versus the lowest UA tertile after adjustments for confounding factors, but not for females. In this cross-sectional study, there was a clear difference in the relation of UA and LVH between males and females. High serum UA was significantly and independently associated with LVH evaluated by echocardiography in only males of a general population.

Friction-reduction effect of the hierarchical surface microstructure of carrion beetle by controlling the real contact area.

The discovery and elucidation of the surface microstructure functions of living organisms are crucial to resolving issues, such as friction. We newly discovered that Necrophila japonica, a type of carrion beetle that lives on the ground surface, exhibited a hierarchical surface microstructure comprising a submicron-sized wrinkle structure on top of a micron-sized microstructure. The surface microstructure of this beetle improved wettability but did not exhibit superhydrophobicity, a well-known function of hierarchical structures, so it was expected to have a different function. By combining the insights in the field of structural mechanics that avoidance of stress concentration by the structural geometry affects deformation with the basic principles of friction, the frictional properties and mechanisms of the hierarchical surface microstructure of carrion beetle were investigated. The measurements of frictional force indicated that the mimicked structure exerted lower frictional forces than flat and single-layer microstructure surfaces. Analysis of finite element method simulations showed that even though the mimicked structure was prone to pressure concentration due to small contact points, the surface contact pressure was reduced more than that of the single-layer structure by hierarchical load dispersion like that of metamaterials. As a result, the suppression of the increase in the real contact area due to deformation suppression contributed to effective friction-reduction. The effective friction-reduction by the hierarchical structure provides not only new insight into the surface microstructure function of various organisms, but also new design for the lubricant-free friction reduction that has been the focus of attention in carbon neutrality and other fields.