Association of postoperative atrial fibrillation with higher dosing ratios of protamine-to-heparin.

Background: Postoperative atrial fibrillation (POAF) is defined as new-onset AF in the immediate postoperative period. The relatively high incidence of POAF after cardiac surgery is well described, but pathophysiological mechanisms underlying the initiation, maintenance, and progression of POAF may be multifactorial and have not yet been comprehensively characterized. One of the mechanisms includes altered Ca2+ kinetics. Accumulating evidence has suggested that altered atrial cytosolic calcium handling contributes to the development of POAF, protamine reversibly modulates the calcium release channel/ryanodine receptor 2 (RyR2) and voltage-dependent cardiac RyR2. However, it is currently unknown whether such abnormalities contribute to the arrhythmogenic substrate predisposing patients to the development of POAF. Methods: We have retrospectively analyzed 147 patients who underwent cardiac surgery with cardiopulmonary bypass support. Of these, 40 patients were excluded from the analysis because of pre-existing AF. All patients received heparin followed by protamine at different dosing ratios of protamine-to-heparin, depending on the periods studied. Results: The dosing ratio of protamine-to-heparin = 1.0 was compared with higher dosing ratios of protamine-to-heparin >1.0 up to 1.7. POAF developed in 15 patients (15/107 = 14%), of these, 5 out of 57 patients (33.3%) in the dosing ratio of protamine-to-heparin = 1.0 and 10 out of 35 patients (66.7%) in the higher dosing ratios of protamine-to-heparin. Statistical significance was observed in patients with higher dosing ratios of protamine-to-heparin, compared with the dosing ratio of protamine-to-heparin = 1.0 (odds ratio = 3.890, 95% CI = 1.130-13.300, p-value = 0.031). When types of diseases were analyzed in terms of higher dosing ratios of protamine-to-heparin, only valvular disorders were significantly associated with POAF (p = 0.04). Conclusions: Protamine is clinically utilized to reverse heparin overdose and has been shown to display immunological and inflammatory alterations. However, its association with POAF has not been reported. Our results provide evidence that higher dosing ratios of protamine-to-heparin may increase the incidence of POAF.

Use of Augmented Reality to Assist Teaching for Future Perfusionists in Extracorporeal Technology.

The aim of this study was to foster the better perfusion education when providing extracorporeal circulation (ECC) technology for future perfusionists. For this purpose, we have developed an augmented reality (AR) program for ECC students. Currently, the cost of equipment and its simulator is high. Furthermore, it is desirable for ECC students to practice at any time. AR describes user experiences that add 2D (plane detection) or 3D elements to the live view from a device's camera in a way that makes those elements appear to inhabit the real world. We can use these technologies to create AR experiences using the back camera of a smartphone or tablet. We can also build our own instrument with custom visualization and data analysis. Although AR technology may not be new, its potential in ECC student education is just beginning to be explored. Unlike other computing technologies, AR interfaces offer seamless interaction between the real and virtual worlds, a tangible interface metaphor, and a means for transitioning between real and virtual worlds. Here, we have shown our experiences of cost-effective AR technology for future perfusionists.

Effect of thrombomodulin on the development of monocrotaline-induced pulmonary hypertension.

PURPOSE: The purpose of the present study was to investigate whether thrombomodulin (TM) prevents the development of pulmonary hypertension (PH) in monocrotaline (MCT)-injected rats. METHODS: Human recombinant TM (3 mg/kg/2 days) or saline were given to MCT-injected male Sprague-Dawley rats for 19 (n = 14) or 29 (n = 11) days. Control rats (n = 6) were run for 19 days. The mean pulmonary artery pressure (mPAP), right ventricular hypertrophy (RVH), percentages of muscularized peripheral arteries (%muscularization), and medial wall thickness of small muscular arteries (%MWT) were measured. To determine inflammatory and coagulation responses, broncho-alveolar lavage fluid (BALF) was analyzed in another set of rats (n = 29). Western blotting for endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS (peNOS) in the lung tissue was performed in separate rats (n = 13). Survival was determined in 60 rats. RESULTS: MCT increased mPAP, RVH, %muscularization, and %MWT. TM treatment significantly reduced mPAP, %muscularization, and %MWT in peripheral arteries with an external diameter of 50-100 µm in 19 days after MCT injection, but the effect was lost after 29 days. MCT increased the levels of tumor necrosis factor alpha, monocyte chemoattractant protein-1, and thrombin-antithrombin complex in BALF. Expression of eNOS increased in MCT rats, while peNOS decreased. The relative amount of peNOS to total eNOS increased in MCT/TM rats compared to MCT/Vehicle rats. A Kaplan-Meier survival curve showed no difference with and without TM. CONCLUSION: Although the administration of TM might slightly delay the progression of MCT-induced PH, the physiological significance for treatment is limited, since the survival rate was not improved.

Transient hypogammaglobulinemia of infancy may be associated with reduced switched memory B cells and del (16) (p11.2p12).

Transient hypogammaglobulinemia of infancy may be associated with chromosome del (16)(p11.2) that has reportedly been associated with other forms of primary immunodeficiency (Clin Immunol, 2009, 131, 24; J Allergy Clin Immunol, 2015;135, 1569).

Pulmonary Barotrauma Following Nasal High-Flow Therapy in a Patient with Bronchiolitis Obliterans Syndrome.

BACKGROUND Pulmonary barotrauma is considered as complication of the use of positive-pressure ventilations. Nasal high-flow therapy is increasingly being used as an alternative to them. Nasal high-flow therapy rarely causes pulmonary barotrauma probably because airway pressures are lower when compared with invasive mechanical ventilation. Bronchiolitis obliterans syndrome after allogenic hematopoietic stem cell transplantation is triggered by an alloimmune response in the bronchioles and causes obstruction of the bronchioles. However, the threshold of additional positive pressure has not been determined in a patient with bronchiolitis obliterans syndrome. CASE REPORT A 14-year-old female patient with acute myeloid leukemia at high risk of recurrence received an allogeneic hematopoietic stem cell transplantation from an unrelated bone marrow donor. After engraftment, she developed acute graft-versus-host disease, followed by chronic graft-versus-host disease. Ten months post-transplantation, she developed bronchiolitis obliterans syndrome. She continued to receive nasal supplemental oxygen therapy for persistent dyspnea due to bronchiolitis obliterans syndrome. At month +25, hypercapnia was noted. Therefore, we carefully initiated nasal high-flow therapy for dyspnea and adjusted the oxygen dose to maintain 90% SpO2 to avoid life-threatening apnea. The flow rate was as low as 14 to 20 L/min to avoid the risk of barotrauma and the deterioration of air trapping. Unfortunately, she died of respiratory failure at month +31 post-transplantation. A lung autopsy revealed pulmonary barotrauma. CONCLUSIONS Nasal high-flow therapy, even at low flow rates, may cause fatal pulmonary barotrauma in bronchiolitis obliterans syndrome.

Thrombomodulin protects against lung damage created by high level of oxygen with large tidal volume mechanical ventilation in rats.

BACKGROUND: Ventilator-induced lung injury (VILI) is associated with inflammatory responses in the lung. Thrombomodulin (TM), a component of the coagulation system, has anticoagulant and anti-inflammatory effects. We hypothesized that the administration of recombinant human soluble TM (rhsTM) would block the development of lung injury. METHODS: Lung injury was induced by high tidal volume ventilation for 2 h with 100% oxygen in rats. Rats were ventilated with a tidal volume of 35 ml/kg with pretreatment via a subcutaneous injection of 3 mg/kg rhsTM (HV (high tidal volume)/TM) or saline (HV/SAL) 12 h before mechanical ventilation. Rats ventilated with a tidal volume of 6 ml/kg under 100% oxygen with rhsTM (LV (low tidal volume)/TM) or saline (LV/SAL) were used as controls. Lung protein permeability was determined by Evans blue dye (EBD) extravasation. RESULTS: Lung injury was successfully induced in the HV/SAL group compared with the LV/SAL group, as shown by the significant decrease in arterial oxygen pressure (PaO2), increased protein permeability, and increase in mean pulmonary artery pressure (mPAP) and ratio of mean pulmonary artery pressure to mean artery pressure (Pp/Ps). Treatment of rats with lung injury with rhsTM (HV/TM) significantly attenuated the decrease in PaO2 and the increase in both mPAP and Pp/Ps, which was associated with a decrease in the lung protein permeability. Lung tissue mRNA expressions of interleukin (IL)-1α, IL-1ß, IL-6, tumor necrosis factor-α, and macrophage inflammatory protein (MIP)-2 were significantly higher in HV than in LV rats. Rats with VILI treated with rhsTM (HV/TM) had significantly lower mRNA expressions of IL-1α, IL-1ß, IL-6, and MIP-2 than those expressions in HV/SAL rats. CONCLUSIONS: Administration of rhsTM may prevent the development of lung injury created by high level of oxygen with large tidal volume mechanical ventilation, which has concomitant decrease in proinflammatory cytokine and chemokine expression in the lung.

Optical assessment of silicon nanowire arrays fabricated by metal-assisted chemical etching.

Silicon nanowire (SiNW) arrays were prepared on silicon substrates by metal-assisted chemical etching and peeled from the substrates, and their optical properties were measured. The absorption coefficient of the SiNW arrays was higher than that for the bulk silicon over the entire region. The absorption coefficient of a SiNW array composed of 10-µm-long nanowires was much higher than the theoretical absorptance of a 10-µm-thick flat Si wafer, suggesting that SiNW arrays exhibit strong optical confinement. To reveal the reason for this strong optical confinement demonstrated by SiNW arrays, angular distribution functions of their transmittance were experimentally determined. The results suggest that Mie-related scattering plays a significant role in the strong optical confinement of SiNW arrays.

Biomechanical characteristics of the lateral ligament of the ankle joint.

The purpose of this study was to investigate the biomechanical properties of the lateral ankle ligaments and to correlate these properties with the distribution of mechanoreceptors in the ligaments reported previously. Biomechanical tensile tests were performed by using a video dimension analyzer to monitor the distortion of the lateral ligament at the pole and center in the animals. The mean upward slope of the load-elongation curves of the pole group was 38.1+/-14.2, and that of the center group was 79.1+/-6.5. The pole of the ligaments tended to be elongated more than the center. These biomechanical results suggest that mechanoreceptors in the pole of the ligaments, compared with those in the center, may receive more mechanical stress and be effective in monitoring of tension applied to the ligament.