Endothelium-Derived Extracellular Vesicles Expressing Intercellular Adhesion Molecules Reflect Endothelial Permeability and Sepsis Severity.

BACKGROUND: Currently, clinical indicators for evaluating endothelial permeability in sepsis are unavailable. Endothelium-derived extracellular vesicles (EDEVs) are emerging as biomarkers of endothelial injury. Platelet endothelial cell adhesion molecule (PECAM) and vascular endothelial (VE)-cadherin are constitutively expressed endothelial intercellular adhesion molecules that regulate intercellular adhesion and permeability. Herein, we investigated the possible association between EDEVs expressing intercellular adhesion molecules (PECAM+ or VE-cadherin+ EDEVs) and endothelial permeability and sepsis severity. METHODS: Human umbilical vein endothelial cells (HUVECs) were stimulated with tumor necrosis factor alpha (TNF-α) directly or after pretreatment with permeability-modifying reagents such as angiopoietin-1, prostacyclin, or vascular endothelial growth factor (VEGF) to alter TNF-α-induced endothelial hyperpermeability. Endothelial permeability was measured using the dextran assay or transendothelial electrical resistance. Additionally, a prospective cross-sectional observational study was conducted to analyze circulating EDEV levels in patients with sepsis. EDEVs were examined in HUVEC culture supernatants or patient plasma (nonsepsis, n = 30; sepsis, n = 30; septic shock, n = 42) using flow cytometry. The Wilcoxon rank-sum test was used for comparisons between 2 groups. Comparisons among 3 or more groups were performed using the Steel-Dwass test. Spearman's test was used for correlation analysis. Statistical significance was set at P < .05. RESULTS: TNF-α stimulation of HUVECs significantly increased EDEV release and endothelial permeability. Pretreatment with angiopoietin-1 or prostacyclin suppressed the TNF-α-induced increase in endothelial permeability and inhibited the release of PECAM+ and VE-cadherin+ EDEVs. In contrast, pretreatment with VEGF increased TNF-α-induced endothelial permeability and the release of PECAM+ and VE-cadherin+ EDEVs. However, pretreatment with permeability-modifying reagents did not affect the release of EDEVs expressing inflammatory stimulus-inducible endothelial adhesion molecules such as E-selectin, intracellular adhesion molecule-1, or vascular cell adhesion molecule-1. The number of PECAM+ EDEVs on admission in the septic-shock group (232 [124, 590]/µL) was significantly higher (P = .043) than that in the sepsis group (138 [77,267]/µL), with an average treatment effect of 98/µL (95% confidence interval [CI], 2-270/µL), and the number of VE-cadherin+ EDEVs in the septic-shock group (173 [76,339]/µL) was also significantly higher (P = .004) than that in the sepsis group (81 [42,159]/µL), with an average treatment effect (ATE) of 79/µL (95% CI, 19-171/µL); these EDEV levels remained elevated until day 5. CONCLUSIONS: EDEVs expressing intercellular adhesion molecules (PECAM+ or VE-cadherin+ EDEVs) may reflect increased endothelial permeability and could be valuable diagnostic and prognostic markers for sepsis.

Examination of the frequency of upward and downward fluctuations in the pressure obtained from the cuff pressure-time curve by continuous measurement of endotracheal tube cuff pressure during thyroid surgery: a case series.

BACKGROUND: Few studies examined time-to-time changes of cuff pressure of an endotracheal tube during surgery. We retrospectively analyzed the changes of cuff pressure during thyroid surgery and examined its relationships with postoperative airway complications. CASE PRESENTATION: Cuff pressure was initially adjusted at 26 cmH2O and continuously measured in 61 patients. The cuff pressure-time curve dynamically fluctuated, and exceeded 30 cmH2O in all patients, whereas decreased to ≤ 20 cmH20 in 42 (69%) patients. Ratio of the period with such an increase and decrease of cuff pressure to the total duration of surgery were 40% (28-66%) and 9% (0-21%), respectively (median, interquartile range). No patients showed symptoms of airway stenosis requiring treatment except one who developed recurrent laryngeal nerve palsy. No patients had lower respiratory tract infection. CONCLUSIONS: Cuff pressure dynamically fluctuated during thyroid surgery. Preventing an increase as well as decrease of cuff pressure is required.

Increase in circulating ACE-positive endothelial microparticles during acute lung injury.

Circulating endothelial microparticles (EMPs) are considered to be markers of endothelial injury, and lung microvascular endothelial cells express higher levels of angiotensin-converting enzyme (ACE). The aim of this study is to examine whether the number of ACE+ microvascular EMPs could be a prognostic marker for the development of acute respiratory distress syndrome (ARDS) in septic patients.The numbers of EMPs and ACE+ EMPs in the culture supernatant from human microvascular endothelial cells, as well as in the blood of mouse lung injury models and septic patients (n=82), were examined using flow cytometry.ACE+ EMPs in the culture supernatant from pulmonary microvascular endothelial cells increased after exposure to an inflammatory stimulus. In the mouse lung injury models, the circulating ACE+ EMPs and ACE+ EMP/EMP ratio were higher than in the controls (p<0.001). The ACE+ EMP/EMP ratio was correlated with the wet/dry lung ratio (rs=0.775, p<0.001). The circulating ACE+ EMPs and ACE+ EMP/EMP ratio on admission were significantly increased in septic patients who developed ARDS compared with septic patients who did not (p<0.001).Therefore, circulating ACE+ EMPs may be a prognostic marker for the development of ARDS in the septic patients.

Comparison of Clinical Efficacy and Anatomical Investigation between Retrolaminar Block and Erector Spinae Plane Block.

Retrolaminar block (RLB) and erector spinae plane block (ESPB) are alternative approaches to paravertebral block (PVB) and are advantageous in that they are easier and safer techniques compared with the traditional PVB. Many clinical reports of these blocks have described their efficacy for ipsilateral thoracic analgesia. The local anesthetic injection points of RLB and ESPB are the lamina and transverse process, respectively. Despite the similarity of the puncture sites, there have been no clinical studies comparing RLB and ESPB. In addition, the underlying mechanism of these blocks has not been clarified. Recent anatomical investigations indicated that the injectate was distributed in the paravertebral space and spread laterally into the intercostal spaces. The limited distribution into the paravertebral space indicated that compared to PVB, RLB and ESPB exert their effects via a different mechanism. In this review, we describe the features of and differences between RLB and ESPB based on current clinical and anatomical reports. We also propose the clinical indication and discuss the differences, clinical outcomes, and anatomical mechanisms of the techniques.

A case of congenital central hypoventilation syndrome.

We encountered a 2-year-old female infant with congenital central hypoventilation syndrome (CCHS) who underwent an abdominal operation for strangulated ileus. Prior to the surgery, at home, the infant had been receiving non-invasive positive-pressure ventilation (NPPV) support only during sleep. However, after postoperative extubation, the blood oxygen saturation (SpO(2)) decreased to approximately 90 % with NPPV during sleep alone, necessitating the use of biphasic cuirass ventilation (BCV) along with NPPV for 2 days. The infant was weaned from the BCV on hospital day 9, and was discharged from the intensive care unit (ICU) on hospital day 13. Although it has been said that CCHS is not under the control of the respiratory center, there are no reports of the true CO(2) response curves in these patients. Therefore, during respiratory management in the ICU post-surgery, we examined (with the consent of the mother) the relationship of the end-tidal carbon dioxide (ETCO(2)) to the tidal volume and respiratory rate, for a period of 6 min in the absence of sedation, using a respiratory profile monitor. Electrocardiographic and SpO(2) monitoring was also conducted at the same time, to ensure the patient's safety. In this patient, while the ETCO(2) increased, the tidal volume and respiratory rate remained unchanged. No relationship was found between the tidal volume and the respiratory rate. Various modalities have been used for the treatment of CCHS (tracheotomy, NPPV, and diaphragmatic pacing). Treatment of these patients in the ICU should be tailored to the needs of individual patients and their families.

Fractal and periodic heart rate dynamics in fetal sheep: comparison of conventional and new measures based on fractal analysis.

The physiological significance of spectral and fractal components of spontaneous heart rate (HR) variability in the fetus remains unclear. To examine the relationship between circadian rhythms in different measures of HR variability, R-R interval time series obtained by fetal ECGs were recorded continuously over 24 h in five pregnant sheep at 116-125 days gestation. Conventional measures of short-term (STV) and long-term variability (LTV), low-frequency (LF; 0.025-0.15 cycles/beat) and high-frequency (HF; 0.2-0.5 cycles/beat) spectral powers, the LF-to-HF ratio, and fractal dimension values were calculated from 24-h ECG recordings and quantified every 60 min. STV, LTV, and LF and HF spectral powers were minimal during the day but increased significantly to their highest values at night. We found a significant positive correlation between these measures, whereas the cosinor method showed significant similarity between their circadian rhythm patterns. Fetal R-R intervals also exhibited fractal structures. Fetal HR variability had a fractal structure, which was similar between day and night. These results suggested that the circadian rhythms exhibited by STV and LTV during the day were mainly due to changes in frequency components rather than to fractal components of fetal HR fluctuation.