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An effective vaccine against Pseudomonas aeruginosa would benefit people susceptible to severe infection. Vaccination targeting V antigen (PcrV) of the P. aeruginosa type III secretion system is a potential prophylactic strategy for reducing P. aeruginosa-induced acute lung injury and acute mortality. We created a recombinant protein (designated POmT) comprising three antigens: full-length PcrV (PcrV#1-#294), the outer membrane domain (#190-342) of OprF (OprF#190-#342), and a non-catalytic mutant of the carboxyl domain (#406-613) of exotoxin A (mToxA#406-#613(E553Δ)). In the combination of PcrV and OprF, mToxA, the efficacy of POmT was compared with that of single-antigen vaccines, two-antigen mixed vaccines, and a three-antigen mixed vaccine in a murine model of P. aeruginosa pneumonia. As a result, the 24 h-survival rates were 79%, 78%, 21%, 7%, and 36% in the POmT, PcrV, OprF, mTox, and alum-alone groups, respectively. Significant improvement in acute lung injury and reduction in acute mortality within 24 h after infection was observed in the POmT and PcrV groups than in the other groups. Overall, the POmT vaccine exhibited efficacy comparable to that of the PcrV vaccine. The future goal is to prove the efficacy of the POmT vaccine against various P. aeruginosa strains.

We encountered two female patients with COVID-19 Eone transferred from the cruise ship, Diamond Princess, docked in the Yokohama port, and the other with community transmission of the infection The former patient had asymptomatic pneumonia, which subsided spontaneously The latter patient suffered from severe rapidly worsening pneumonia which necessitated mechanical ventilation and extracorporeal membrane oxygenation, but eventually showed complete resolution of the disease Although the lung involvement in those two cases at their first evaluation seemed to be equal, they exhibited very different clinical courses Eone showing self-limiting asymptomatic pneumonia and the other showing severe progressive pneumonia

In recent years, numerous outbreaks of multidrug-resistant Pseudomonas aeruginosa have been reported across the world. Once an outbreak occurs, besides routinely testing isolates for susceptibility to antimicrobials, it is required to check their virulence genotypes and clonality profiles. Replacing pulsed-field gel electrophoresis DNA fingerprinting are faster, easier-to-use, and less expensive polymerase chain reaction (PCR)-based methods for characterizing hospital isolates. P. aeruginosa possesses a mosaic genome structure and a highly conserved core genome displaying low sequence diversity and a highly variable accessory genome that communicates with other Pseudomonas species via horizontal gene transfer. Multiple-locus variable-number tandem-repeat analysis and multilocus sequence typing methods allow for phylogenetic analysis of isolates by PCR amplification of target genes with the support of Internet-based services. The target genes located in the core genome regions usually contain low-frequency mutations, allowing the resulting phylogenetic trees to infer evolutionary processes. The multiplex PCR-based open reading frame typing (POT) method, integron PCR, and exoenzyme genotyping can determine a genotype by PCR amplifying a specific insertion gene in the accessory genome region using a single or a multiple primer set. Thus, analyzing P. aeruginosa isolates for their clonality, virulence factors, and resistance characteristics is achievable by combining the clonality evaluation of the core genome based on multiple-locus targeting methods with other methods that can identify specific virulence and antimicrobial genes. Software packages such as eBURST, R, and Dendroscope, which are powerful tools for phylogenetic analyses, enable researchers and clinicians to visualize clonality associations in clinical isolates.

Background Perioperative atrial fibrillation (POAF) in noncardiac surgeries is common. However, it is unclear whether such atrial fibrillation (AF) recurs in the long term. Methods This study was a prospective, single-center, observational study that included patients who underwent noncardiac surgeries for malignancies. Patients were followed up for 1 year to evaluate the incidence of AF, ischemic stroke, and mortality. An event-triggered recorder was used in patients with POAF. The incidences were compared according to the presence of POAF. Results Of 752 consecutive patients, 77 (10.2%) developed POAF and wore an event recorder for 19 (12-30) days. AF and ischemic stroke at 1 year were observed in 24 patients (31.1%) and 2 patients (2.6%) with POAF and 4 patients (0.6%) and 3 patients (0.4%) without POAF, respectively. Of the 24 patients with POAF and AF recurrence, 22 (92%) were asymptomatic. Anticoagulation was prescribed in 67 patients (87%) with POAF. Multivariate Cox regression analysis demonstrated that a higher AF recurrence rate in patients with POAF was associated with hypertension (hazard ratio, 2.79; 95% confidence interval, 1.06-7.38) and serum creatinine level (hazard ratio for 20 μmol/L increase, 2.32; 95% confidence interval, 1.16-4.62). Conclusions AF recurs in approximately 30% of patients with POAF with malignancy in the subsequent year; most recurrences are asymptomatic.

Background. When an obturator nerve block (ONB) is performed, the conventional landmark method or ultrasound-guided method is used. The major complications of this block are hematoma, but there are very few reports of its complications. We encountered massive bleeding and a huge hematoma after ONB. Case Presentation. A 95-year-old female underwent transurethral resection of the bladder tumor. Induction of anesthesia was accomplished via spinal anesthesia and right ONB using the landmark method. Postoperatively, subcutaneous bleeding was detected in the lower right interior thigh. Concentrated red cell transfusion was conducted to address the anemia. There was no subsequent expansion of the hematoma. It resolved on postoperative day (POD) 53. The hematoma was deemed to be inadvertently introduced due to an obturator artery puncture during the obturator nerve block. Conclusions. Close attention is necessary to avoid advancing the needle too deep into the obturator during obturator nerve block.

We have implemented several preventive measures to reduce central line-associated bloodstream infection (CLABSI) in the general intensive care unit (ICU) of a university hospital in Japan. Here, we analyzed the factors associated with CLABSI in patients with central venous catheter (CVC) insertions and evaluated the effects of our implemented preventive measures. From July 2013 to June 2018, data was collected from the medical records of 1472 patients with 1635 CVC insertions, including age, sex, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, duration of ICU stay, duration of catheter insertion, insertion site, and mechanical ventilation status. During weekly conferences, a surveillance team comprising intensive care and infection control doctors and nurses determined the patients' CLABSI status. The analyzed factors were compared between CLABSI and central line patients without bloodstream infection. Multivariate analysis revealed three factors associated with CLABSI. Adjusted odds ratios with 95% confidence intervals were as follows: duration of ICU stay, 1.032 (1.019-1.044); duration of catheter insertion, 1.041 (1.015-1.066); and APACHE II score, 1.051 (1.000-1.105). The prominent risk factors were associated with the severity of the initial condition and exacerbation of the clinical condition of the patients during their stays in the ICU. Further strategies to reduce CLABSI must be developed.

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.

Perioperative complications have been reported to be associated with a lower incidence of cancer-free survival. Perioperative atrial fibrillation (POAF) is one of occasionally observed complications in patients with malignancies who undergo noncardiac surgeries. However, the long-term clinical impact of POAF on those with malignancies have remained unknown. This was a prospective, single-center, observational study. Patients who underwent noncardiac surgeries for definitive malignancies between 2014 and 2017 were included. The primary and secondary endpoints were 3-year recurrence of malignancies and cancer death, respectively. The present study included consecutive 752 patients (mean age, 68 ± 11 years; males, 62%), and POAF was observed in 77 patients. The follow-up duration was 1037 (interquartile range, 699–1408) days. The 3-year recurrence of malignancies was observed in 239 (32%) patients (POAF, 32 [42%]; non-POAF, 207 [31%]) and 3-year mortality was 130 patients (17%). Cardiac, noncardiac, and cancer deaths were observed in 4 (0.5%), 126 (17%), and 111 (15%) patients, respectively. Multivariate Cox regression analysis demonstrated that POAF was associated with 3-year recurrence of malignancies (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.15–2.52). Landmark analysis demonstrated that POAF tended to be correlated with the incidence of 3-year cancer death (HR, 1.79; 95% CI, 0.96–3.31). In conclusion, POAF is associated with the subsequent recurrence of malignancies. The association of arrhythmia with cancer death may be revealed under longer follow-up durations. Clinical Trial Registration: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000018270 . UMIN ID: UMIN000016146.

Along with the recent spread of multidrug-resistant bacteria, outbreaks of extended-spectrum β-lactamase (ESBL) and carbapenemase-producing bacteria present a serious challenge to clinicians. β-lactam antibiotics are the most frequently used antibacterial agents and ESBLs, and carbapenemases confer resistance not only to carbapenem antibiotics but also to penicillin and cephem antibiotics. The mechanism of β-lactam resistance involves an efflux pump, reduced permeability, altered transpeptidases, and inactivation by β-lactamases. Horizontal gene transfer is the most common mechanism associated with the spread of extended-spectrum β-lactam- and carbapenem resistance among pathogenic bacterial species. Along with the increase in antimicrobial resistance, many different types of ESBLs and carbapenemases have emerged with different enzymatic characteristics. For example, carbapenemases are represented across classes A to D of the Ambler classification system. Because bacteria harboring different types of ESBLs and carbapenemases require specific therapeutic strategies, it is essential for clinicians to understand the characteristics of infecting pathogens. In this review, we summarize the current knowledge on carbapenem resistance by ESBLs and carbapenemases, such as class A carbapenemases, class C extended-spectrum AmpC (ESAC), carbapenem-hydrolyzing class D β-lactamases (CHDLs), and class B metallo-β-lactamases, with the aim of aiding critical care clinicians in their therapeutic decision making.

A 13-month-old infant weighing 8.3 kg with a height of 72.3 cm visited our hospital for surgical resection of facial vascular malformation detected at birth. Because we anticipated the patient would have difficult airway management and massive perioperative bleeding, we postponed surgery to discuss the appropriate timing and general anesthesia approach with anesthesiologists at other institutions, while explaining the risk of general anesthesia and bleeding to the parents. When the patient was 21 months old and 10 kg, he started bleeding while undressing, when his lips touched his clothes. Because the cricothyroid membrane puncture kit (QuickTrach Child™ (VBM Medizintechnik GmbH, Sulz am Neckar, Germany)) can be used on infants weighing over 10 kg, we decided to give him general anesthesia. The infant was successfully intubated by Airwayscope™ and the lesion was surgically removed in accordance with the preoperative plan. The procedure took 65 min and created 8 g of bleeding. The infant had no postoperative bleeding or respiratory complications. There is no data on the timing of safe anesthesia management in infants with difficult airway management. Thus, taking the time to discuss the case with surgeons, other anesthesiologists, and the parents can be helpful.

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.

High-flow nasal cannula (HFNC) therapy has been increasingly applied to treat patients with severe hypoxemic respiratory failure. We investigated whether vital signs reflect the reduction of work of breathing in a simulator study and a clinical study. In the simulator study, a standard model high-fidelity human patient simulator (HPS) directly received 35 L/minute of 100% O2 via the HFNC. In the clinical study, the medical records of patients with hypoxemic respiratory failure who received HFNC therapy between January 2013 and May 2015 were retrospectively reviewed. Statistical analysis was performed using a one-way repeated analysis of variance followed by Bonferroni post-hoc testing. In the HPS, HFNC therapy significantly reduced the partial pressure of alveolar CO2, respiratory rate, and tidal volume ( p < 0.001), and all values returned to baseline following HFNC therapy termination ( p < 0.001). In the clinical study including 48 patients, the respiratory rate was significantly reduced from 27 ± 9 (baseline) to 24 ± 8 (3 hours), 24 ± 8 (5 hours), and 24 ± 8.0 (6 hours) ( p < 0.05). The heart rate also decreased significantly ( p < 0.05). Our results suggested that HFNC therapy reduced work of breathing and assessing vital signs can be important.

The mechanisms underlying the effects of γ-globulin therapy for bacterial infections are thought to involve bacterial cell lysis via complement activation, phagocytosis via bacterial opsonization, toxin neutralization, and antibody-dependent cell-mediated cytotoxicity. Nevertheless, recent advances in the study of pathogenicity in gram-negative bacteria have raised the possibility of an association between γ-globulin and bacterial toxin secretion. Over time, new toxin secretion systems like the type III secretion system have been discovered in many pathogenic gram-negative bacteria. With this system, the bacterial toxins are directly injected into the cytoplasm of the target cell through a special secretory apparatus without any exposure to the extracellular environment and, therefore, with no opportunity for antibodies to neutralize the toxin. However, because antibodies against the V-antigen, which is located on the needle-shaped tip of the bacterial secretion apparatus, can inhibit toxin translocation, this raises the hope that the toxin might be susceptible to antibody targeting. Because multi-drug resistant bacteria are now prevalent, inhibiting this secretion mechanism is attractive as an alternative or adjunctive therapy against lethal bacterial infections. Thus, it would not be unreasonable to define the blocking effect of anti-V-antigen antibodies as the fifth mechanism for immunoglobulin action against bacterial infections.

The V-antigen, a virulence-associated protein, was first identified inYersinia pestismore than half a century ago. Since then, other V-antigen homologs and orthologs have been discovered and are now considered vital molecules for the toxic effects mediated by the type III secretion system in infections caused by various pathogenic Gram-negative bacteria. After purifying recombinant V-antigen proteins including PcrV fromPseudomonas aeruginosa, LcrV fromYersinia, LssV fromPhotorhabdus luminescens, AcrV fromAeromonas salmonicida, and VcrV fromVibrio parahaemolyticus, we developed an enzyme-linked immunoabsorbent assay to measure titers against each V-antigen in the sera collected from 186 adult volunteers. Different titer-specific correlation levels were determined for the five V-antigens. The anti-LcrV and anti-AcrV titers shared the highest correlation with each other, with a correlation coefficient of 0.84. The next highest correlation coefficient was between anti-AcrV and anti-VcrV titers at 0.79, while the lowest correlation was found between anti-LcrV and anti-VcrV titers, which were still higher than 0.7 Sera from mice immunized with one of the five recombinant V-antigens displayed cross-antigenicity with some of the other four V-antigens, supporting the results from the human sera. Thus, the serum anti-V-antigen titer measurement system could potentially be used for epidemiological investigations on various pathogenic Gram-negative bacteria.

The secondary in-hospital epidemiological investigation for drug-resistant Pseudomonas aeruginosa infections was conducted to evaluate the in-hospital situation and identify any associations between exoenzyme genotypes and other genotypes and antimicrobial resistance characteristics, at the University Hospital in Kyoto, Japan, following a reported outbreak of antimicrobial-resistant P. aeruginosa ST357 between 2005 and 2014. Twelve of the 546 P. aeruginosa isolates collected during the follow-up period were resistant to more than two classes of antimicrobials. All isolates were resistant to fluoroquinolones and 8 (66.7%) showed carbapenem resistance. None of the isolates fulfilled the clinical criteria for multidrug-resistant P. aeruginosa. All isolates were metallo-β-lactamase test-negative. Among five exoS (−)exoU (+) isolates, three possessing a class 1 integron with gene cassette aadB + cmlA6 were classified as ST357, and one isolate containing a class 1 integron with aacA31 was ST235. Collectively, the second survey results confirm that the initial outbreak is currently undergoing convergence. By combining data from the first and second surveys, we showed that prevalent STs such as ST357 and ST235 are associated with fluoroquinolone resistance, class 1 integron-associated resistance to β-lactams and aminoglycosides, and cytotoxic exoU (+) genotypes. With the current worldwide spread of ST357 and ST235 isolates, it is important to evaluate epidemiological trends for high-risk P. aeruginosa isolates by continuous hospital monitoring.

Massive leaks in the anesthesia circuit may cause intraoperative hypoventilation and awareness; we experienced this with a disposable CO2 absorber in Perseus A500, which uses turbine ventilation to create positive-pressure ventilation. Consequently, manual ventilation was rendered impossible. During prolonged surgeries, CO2 absorbers may be replaced by a new one. In our case, the replacement had an occult leak. Absorbers should be checked before the exchange, and the econometer or reservoir bag's filling state should be monitored. Anesthesia providers should know an anesthesia machine's dynamics and breathing system to provide appropriate management of such a leak.

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.

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.

BackgroundPerioperative atrial fibrillation (POAF) is one of the common arrhythmias in the setting of non-cardiac surgeries for malignancy. As POAF may cause subsequent adverse events, it is important to confirm its characteristics and risk factors.Materials and methodsThe prospective cohort study of surveillance for perioperative atrial fibrillation recurrence (PREDICT AF RECURRENCE) is an ongoing prospective, single-center, observational study that aims to illustrate the clinical impact of POAF in major non-cardiac surgery for malignancy. Patients who planned to undergo non-cardiac surgery for definitive/suspected malignancy were registered. Those with a history of AF and atrial flutter were excluded. Any 30-day complications included acute myocardial infarction, congestive heart failure, bleeding, thrombosis, any infection, and acute kidney injury. The primary endpoint was an incidence of POAF.ResultsThe present study included 799 patients (age, 68 ± 11; male, 62%). Of these, 80 patients (10.0%) developed POAF. Notably, 66 patients (83%) had no symptoms. Any 30-day complications occurred in 180 patients (23%) (with POAF: 34 (43%); without POAF: 146 (20%); p < 0.001). POAF in 17 patients (50%) was preceded by the development of complications. No patient developed cardiogenic shock and/or acute heart failure. The association between 30-day complications and POAF development were analyzed using the multivariate adjusted model (odds ratio: 2.84; 95% confidence interval: 1.74-4.62; p < 0.001).ConclusionTen percent of patients who underwent non-cardiac surgery for malignancy developed POAF, which was strongly associated with perioperative complications. As a majority were asymptomatic, careful observation using electrocardiography monitoring is important to avoid oversights.Clinical trial registrationUMIN ID: UMIN000016146.

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.

Background Proteomics is increasingly leading to biomarker discovery in human disease. Epithelial lining fluid (ELF), until now only recovered indirectly, diluted in BAL fluid, is an attractive sample for lung disease proteomics. The direct recovery of undiluted ELF is now possible using a bronchoscopic microsampling (BMS) probe. In this preliminary study of anesthetized ventilated rabbits, we applied this probe to recover ELF and to analyze the resulting samples with the aim of determining their potential in lung disease biomarker discovery. Methods In order to do so, a method was devised and evaluated in preliminary experiments both for nonbronchoscopic use of the probe and for recovering undiluted ELF from probe tips. To verify the proteomic potential of the sample, the recovered ELF was separated by one-dimensional polyacrylamide gel electrophoresis, and the resulting lane was cut into multiple fractions, each of which was digested and analyzed by liquid chromatography tandem mass spectrometry. The identified proteins were then searched against Medline for association with broad categories of lung disease. Results Nonbronchoscopic use of the probe allowed successful ELF sampling and the recovery of undiluted ELF from probe tips. Proteomic analysis showed that ELF contains many proteins that have already been reported as being associated with lung disease as well as proteins potentially correlated with lung disease. Conclusions This preliminary study of undiluted ELF, as recovered by the BMS probe, shows that it may be an ideal sample for lung proteomics. The potential application of this sampling technique in various lung diseases will need to be confirmed by future studies.

Purpose Pulse oximetry is routinely used to continuously and non-invasively monitor arterial oxygen saturation (SaO2). When oxygen saturation by pulse oximeter (SpO2) overestimates SaO2, hypoxemia may be overlooked. We compared the SpO2 - SaO2 differences among three pulse oximeters in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who spent their daily lives in a poor oxygen state. Material and Method This prospective observational study recruited 32 patients with CTEPH undergoing elective cardiac catheterization. As we collected arterial blood samples in the catheter laboratory, SpO2 values were simultaneously recorded. Three pulse oximeters were used on each patient, and SpO2 values were compared with oximetry readings using a blood gas analyzer. To determine the optimal SpO2 value by which to detect hypoxemia (SaO2≦90%), we generated receiver operating characteristic (ROC) curves for each pulse oximeter. Result The root mean square of each pulse oximeter was 1.79 (OLV-3100), 1.64 (N-BS), and 2.50 (Masimo Radical). The mean bias (SpO2 - SaO2) for the 90%–95% saturation range was significantly higher for Masimo Radical (0.19 +/- 1.78% [OLV-3100], 0.18 +/- 1.63% [N-BS], and 1.61 +/- 1.91% [Masimo Radical]; p

Pseudomonas aeruginosa uses a complex type III secretion system to inject the toxins ExoS, ExoT, ExoU, and ExoY into the cytosol of target eukaryotic cells. This system is regulated by the exoenzyme S regulon and includes the transcriptional activator ExsA. Of the four toxins, ExoU is characterized as the major virulence factor responsible for alveolar epithelial injury in patients with P. aeruginosa pneumonia. Virulent strains of P. aeruginosa possess the exoU gene, whereas non-virulent strains lack this particular gene. The mechanism of virulence for the exoU+ genotype relies on the presence of a pathogenic gene cluster (PAPI-2) encoding exoU and its chaperone, spcU. The ExoU toxin has a patatin-like phospholipase domain in its N-terminal, exhibits phospholipase A2 activity, and requires a eukaryotic cell factor for activation. The C-terminal of ExoU has a ubiquitinylation mechanism of activation. This probably induces a structural change in enzymatic active sites required for phospholipase A2 activity. In P. aeruginosa clinical isolates, the exoU+ genotype correlates with a fluoroquinolone resistance phenotype. Additionally, poor clinical outcomes have been observed in patients with pneumonia caused by exoU+-fluoroquinolone-resistant isolates. Therefore, the potential exists to improve clinical outcomes in patients with P. aeruginosa pneumonia by identifying virulent and antimicrobial drug-resistant strains through exoU genotyping or ExoU protein phenotyping or both.