Saeko Hamaoka

Kyoto Prefectural University of Medicine

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Teiji Sawa

Kyoto Prefectural University of Medicine

Yoshifumi Naito

Kyoto Prefectural University of Medicine

Mao Kinoshita

Kyoto Prefectural University of Medicine

Koichi Akiyama

Kindai University

Masaru Shimizu

Brigham and Women's Hospital

Hideya Kato

Saiseikai Shigaken Hospital

Yasufumi Nakajima

Kindai University

Hideya Katoh

Kyoto Prefectural University of Medicine

Atsushi Kainuma

Kyoto Prefectural University of Medicine

Keiichi Itatani

Nagoya City University

Cooperative Institutions

Kyoto Prefectural University of Medicine

University Hospital Kyoto Prefectural University of Medicine

University of California, San Francisco

Kansai Medical University

Cleveland Clinic

The University of Tokyo

Kyoto College of Medical Science

Japan Society for the Promotion of Science

Kyoto University

Osaka University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Erratum to: Vector flow mapping analysis of left ventricular energetic performance in healthy adult volunteers

BMC Cardiovascular Disorders (2017)

Koichi Akiyama Sachiko Maeda Tasuku Matsuyama Atsushi Kainuma Maki Ishii

Angiology

Vector flow

10.1186/s12872-017-0612-4

Cite

Citations (2)

Flow-dynamics assessment of mitral-valve surgery by intraoperative vector flow mapping

Interactive Cardiovascular and Thoracic Surgery (2017)

Koichi Akiyama Naotoshi Nakamura Keiichi Itatani Yoshifumi Naito Mao Kinoshita

We assessed vortex patterns and energy loss in left ventricular flow in patients who underwent mitral valve repair or replacement with bioprosthetic valves.Vector flow mapping was performed before and after the procedure in 15 and 17 patients who underwent repair and replacement, respectively. The preprocedure mitral-septal angle was measured in all patients. Relationships between vortex patterns or energy loss change (ELC) and annuloplasty ring or bioprosthetic valve sizes or the effect of mitral leaflet resection in the repair group were statistically analysed.Normal vortex patterns were observed in 13 and 1 patients who underwent repair and replacement, respectively. Abnormal vortex patterns were observed in 2 and 16 patients who underwent repair and replacement, respectively. ELC was significantly higher in the replacement group (196.6 ± 180.8) than in the repair group (71.9 ± 43.9). In the repair group, preoperative mitral-septal angles in patients with normal vortex patterns (79.2° ± 3.4°) were significantly larger than those in patients with abnormal vortex patterns (67.5° ± 3.5°). No significant differences were observed in the effects of annuloplasty ring and bioprosthetic valve sizes on vortex patterns and ELC, and in the effect of mitral valve resection (80.4 ± 56.3) and respect (without leaflet resection) (53.8 ± 28.4) on ELC in the repair group.Mitral valve replacement alters the intraventricular vortex pattern and increases flow energy loss. A small mitral-septal angle is a risk factor for abnormal vortex patterns after mitral valve repair surgery.

Mitral valve replacement

10.1093/icvts/ivx033

Cite

Citations (39)

Vector flow mapping analysis of left ventricular energetic performance in healthy adult volunteers

BMC Cardiovascular Disorders (2017)

Koichi Akiyama Sachiko Maeda Tasuku Matsuyama Atsushi Kainuma Maki Ishii

Vector flow mapping, a novel flow visualization echocardiographic technology, is increasing in popularity. Energy loss reference values for children have been established using vector flow mapping, but those for adults have not yet been provided. We aimed to establish reference values in healthy adults for energy loss, kinetic energy in the left ventricular outflow tract, and the energetic performance index (defined as the ratio of kinetic energy to energy loss over one cardiac cycle). Transthoracic echocardiography was performed in fifty healthy volunteers, and the stored images were analyzed to calculate energy loss, kinetic energy, and energetic performance index and obtain ranges of reference values for these. Mean energy loss over one cardiac cycle ranged from 10.1 to 59.1 mW/m (mean ± SD, 27.53 ± 13.46 mW/m), with a reference range of 10.32 ~ 58.63 mW/m. Mean systolic energy loss ranged from 8.5 to 80.1 (23.52 ± 14.53) mW/m, with a reference range of 8.86 ~ 77.30 mW/m. Mean diastolic energy loss ranged from 7.9 to 86 (30.41 ± 16.93) mW/m, with a reference range of 8.31 ~ 80.36 mW/m. Mean kinetic energy in the left ventricular outflow tract over one cardiac cycle ranged from 200 to 851.6 (449.74 ± 177.51) mW/m with a reference range of 203.16 ~ 833.15 mW/m. The energetic performance index ranged from 5.3 to 37.6 (18.48 ± 7.74), with a reference range of 5.80 ~ 36.67. Energy loss, kinetic energy, and energetic performance index reference values were defined using vector flow mapping. These reference values enable the assessment of various cardiac conditions in any clinical situation.

Vector flow

Ventricular outflow tract

Reference range

Cardiac cycle

10.1186/s12872-016-0444-7

Cite

Citations (57)

MITRAL VALVE REPLACEMENT IMPAIRS LEFT VENTRICULAR BLOOD FLOW

Journal of the American College of Cardiology (2016)

Koichi Akiyama Keiichi Itatani Mao Kinoshita Masaru Shimizu Saeko Hamaoka

Mitral valve replacement

10.1016/s0735-1097(16)31702-8

Cite

Citations (1)

成人における血清抗Pseudomonas aeruginosa PcrV力価の疫学的解析

Microbiology and Immunology (2016)

Yasumoto Hiroaki Hideya Katoh Kinoshita Mao Masaru Shimizu Saeko Hamaoka

Pseudomonadales

Source

Cite

Citations (0)

IV Immunoglobulin for Acute Lung Injury and Bacteremia in Pseudomonas aeruginosa Pneumonia*

Critical Care Medicine (2015)

Hideya Katoh Hiroaki Yasumoto Masaru Shimizu Saeko Hamaoka Mao Kinoshita

Virulent and multidrug-resistant Pseudomonas aeruginosa causes a lethal pneumonia, especially in patients who are artificially ventilated. It has been reported that the virulence mechanism used by P. aeruginosa, which is linked to acute lung injury, is strongly associated with the type III secretion system, and specific antibodies targeting this system have shown a protective effect in both experimental and clinical settings. We investigated the effect of administering IV immunoglobulins on P. aeruginosa pneumonia, including its associated bacteremia and mortality, although focusing especially on type III secretion system-associated P. aeruginosa virulence.Prospective randomized and controlled animal study.University laboratory.Male ICR mice.Mice were infected intratracheally with a lethal dose of the virulent P. aeruginosa PA103 strain. IV immunoglobulin administration was examined in three different settings: 1) premixed; 2) pre-IV, prophylactic administration before bacterial infection; and 3) post-IV, therapeutic administration after bacterial infection. The effect of specific antigen titer depletion of IV immunoglobulins was also examined.Survival and body temperature were monitored for 24 hours. Bacteremia, cytokine concentration, myeloperoxidase activity, WBC counts in the blood, and lung bacterial load were evaluated. Survival improved significantly in mice that received IV immunoglobulins (p < 0.05). Lung edema, lung bacteriologic load, and bacteremia decreased significantly in the IV immunoglobulin-treated mice (p < 0.05). The mechanism of protection was associated with the presence of antibodies against both PcrV and some bacterial surface antigens in the IV immunoglobulins.IV immunoglobulin administration had a significantly protective effect against lethal infection from virulent P. aeruginosa. Prophylactic IV immunoglobulin administration at the highest dose was comparable with that achieved by administrating a specific anti-PcrV polyclonal IgG into the mice. The mechanism of protection is likely to involve the synergic action of anti-PcrV titers and antibodies against some surface antigen(s) that block the type III secretion system-associated virulence of P. aeruginosa.

Bacteremia

10.1097/ccm.0000000000001271

Cite

Citations (27)

Efficacy comparison of adjuvants in PcrV vaccine against Pseudomonas aeruginosa pneumonia

Microbiology and Immunology (2017)

Saeko Hamaoka Yoshifumi Naito Hideya Katoh Masaru Shimizu Mao Kinoshita

ABSTRACT Vaccination against the type III secretion system of P. aeruginosa is a potential prophylactic strategy for reducing the incidence and improving the poor prognosis of P. aeruginosa pneumonia. In this study, the efficacies of three different adjuvants, Freund's adjuvant (FA), aluminum hydroxide (alum) and CpG oligodeoxynucleotide (ODN), were examined from the viewpoint of inducing PcrV‐specific immunity against virulent P. aeruginosa . Mice that had been immunized intraperitoneally with recombinant PcrV formulated with one of the above adjuvants were challenged intratracheally with a lethal dose of P. aeruginosa . The PcrV–FA immunized group attained a survival rate of 91%, whereas the survival rates of the PcrV–alum and PcrV–CpG groups were 73% and 64%, respectively. In terms of hypothermia recovery after bacterial instillation, PcrV–alum was the most protective, followed by PcrV–FA and PcrV–CpG. The lung edema index was lower in the PcrV–CpG vaccination group than in the other groups. PcrV–alum immunization was associated with the greatest decrease in myeloperoxidase in infected lungs, and also decreased the number of lung bacteria to a similar number as in the PcrV–FA group. There was less neutrophil recruitment in the lungs of mice vaccinated with PcrV–alum or PcrV–CpG than in those of mice vaccinated with PcrV–FA or PcrV alone. Overall, in terms of mouse survival the PcrV–CpG vaccine, which could be a relatively safe next‐generation vaccine, showed a comparable effect to the PcrV–alum vaccine.

Alum

CpG Oligodeoxynucleotide

10.1111/1348-0421.12467

Cite

Citations (24)

The prophylactic effects of human IgG derived from sera containing high anti-PcrV titers against pneumonia-causingPseudomonas aeruginosa

Human Vaccines & Immunotherapeutics (2016)

Mao Kinoshita Hideya Kato Hiroaki Yasumoto Masaru Shimizu Saeko Hamaoka

The PcrV cap structure of the type III secretory apparatus of Pseudomonas aeruginosa is a vaccine target. Human immunoglobulin G (IgG) molecules extracted from sera containing high or low anti-PcrV titers were tested for their effects against P. aeruginosa pneumonia in a mouse model. Among 198 volunteers, we selected the top 10 high anti-PcrV titer sera and the bottom 10 low anti-PcrV titer sera and extracted the IgG fraction from each serum sample. First, we examined the effects of the IgG against virulent P. aeruginosa. A lethal dose of P. aeruginosa premixed with saline, low titer human IgG, high titer human IgG, or rabbit-derived polyclonal anti-PcrV IgG was intratracheally administered into the lungs of mice, and their survival and lung inflammation were evaluated for 24 h. The high anti-PcrV titer human IgG had a prophylactic effect. Next, the prophylactic effects of intravenous administration of extracted and pooled high or low anti-PcrV titer human IgG were examined. Here, prophylactic intravenous administration of pooled high anti-PcrV titer human IgG, which showed binding capacity to P. aeruginosa PcrV, was more effective than the administration of its low titer pooled equivalent, and the measured physiological and inflammatory parameters correlated with the anti-PcrV titer levels. This result indirectly implies that high anti-PcrV titers in blood can help to protect against virulent P. aeruginosa infections. In addition, the IgG fractions from such high titer sera have potential to be a source of specific intravenous immunoglobulin products for passive vaccination against virulent P. aeruginosa infections.

10.1080/21645515.2016.1209280

Cite

Citations (19)

The protective effects of nasal PcrV‐CpG oligonucleotide vaccination against Pseudomonas aeruginosa pneumonia

Microbiology and Immunology (2018)

Yoshifumi Naito Saeko Hamaoka Mao Kinoshita Atsushi Kainuma Masaru Shimizu

An effective vaccine against Pseudomonas aeruginosa would be hugely beneficial to people who are susceptible to the serious infections it can cause. Vaccination against PcrV of the P. aeruginosa type III secretion system is a potential prophylactic strategy for improving the incidence and prognosis of P. aeruginosa pneumonia. Here, the effect of nasal PcrV adjuvanted with CpG oligodeoxynucleotide (CpG) was compared with a nasal PcrV/aluminum hydroxide gel (alum) vaccine. Seven groups of mice were vaccinated intranasally with one of the following: 1, PcrV-CpG; 2, PcrV-alum; 3, PcrV alone; 4, CpG alone; 5, alum alone; 6 and 7, saline control. Fifty days after the first immunization, anti-PcrV IgG, IgA and IgG isotype titers were measured; significant increases in these titers were detected only in the PcrV-CpG vaccinated mice. The vaccinated mice were then intratracheally infected with a lethal dose of P. aeruginosa and their body temperatures and survival monitored for 24 hr, edema, bacteria, myeloperoxidase activity and lung histology also being evaluated at 24 hr post-infection. It was found that 73% of the PcrV-CpG-vaccinated mice survived, whereas fewer than 30% of the mice vaccinated with PcrV-alum or adjuvant alone survived. Lung edema and other inflammation-related variables were less severe in the PcrV-CpG group. The significant increase in PcrV-specific IgA titers detected following PcrV-CpG vaccination is probably a component of the disease protection mechanism. Overall, our data show that intranasal PcrV-CpG vaccination has potential efficacy for clinical application against P. aeruginosa pneumonia.

10.1111/1348-0421.12658

Cite

Citations (25)

Pseudomonas aeruginosa Type III Secretory Toxin ExoU and Its Predicted Homologs

Toxins (2016)

Teiji Sawa Saeko Hamaoka Mao Kinoshita Atsushi Kainuma Yoshifumi Naito

Pseudomonas aeruginosa ExoU, a type III secretory toxin and major virulence factor with patatin-like phospholipase activity, is responsible for acute lung injury and sepsis in immunocompromised patients. Through use of a recently updated bacterial genome database, protein sequences predicted to be homologous to Ps. aeruginosa ExoU were identified in 17 other Pseudomonas species (Ps. fluorescens, Ps. lundensis, Ps. weihenstephanensis, Ps. marginalis, Ps. rhodesiae, Ps. synxantha, Ps. libanensis, Ps. extremaustralis, Ps. veronii, Ps. simiae, Ps. trivialis, Ps. tolaasii, Ps. orientalis, Ps. taetrolens, Ps. syringae, Ps. viridiflava, and Ps. cannabina) and 8 Gram-negative bacteria from three other genera (Photorhabdus, Aeromonas, and Paludibacterium). In the alignment of the predicted primary amino acid sequences used for the phylogenetic analyses, both highly conserved and nonconserved parts of the toxin were discovered among the various species. Further comparative studies of the predicted ExoU homologs should provide us with more detailed information about the unique characteristics of the Ps. aeruginosa ExoU toxin.

Pseudomonas exotoxin

10.3390/toxins8110307

Cite

Citations (22)