Influence of pharyngeal airway respiration pressure on Class II mandibular retrusion in children: A computational fluid dynamics study of inspiration and expiration.

OBJECTIVES: To examine the influence of negative pressure of the pharyngeal airway on mandibular retraction during inspiration in children with nasal obstruction using the computational fluid dynamics (CFD) method. SETTING AND SAMPLE POPULATION: Sixty-two children were divided into Classes I, II (mandibular retrusion) and III (mandibular protrusion) malocclusion groups. MATERIAL AND METHODS: Cone-beam computed tomography data were used to reconstruct three-dimensional shapes of the nasal and pharyngeal airways. Airflow pressure was simulated using CFD to calculate nasal resistance and pharyngeal airway pressure during inspiration and expiration. RESULTS: Nasal resistance of the Class II group was significantly higher than that of the other two groups, and oropharyngeal airway inspiration pressure in the Class II (-247.64 Pa) group was larger than that in the Class I (-43.51 Pa) and Class III (-31.81 Pa) groups (P<.001). The oropharyngeal airway inspiration-expiration pressure difference in the Class II (-27.38 Pa) group was larger than that in the Class I (-5.17 Pa) and Class III (0.68 Pa) groups (P=.006). CONCLUSION: Large negative inspiratory pharyngeal airway pressure due to nasal obstruction in children with Class II malocclusion may be related to their retrognathia.

Generation of α-1,3-Galactosyltransferase-Deficient Porcine Embryonic Fibroblasts by CRISPR/Cas9-Mediated Knock-in of a Small Mutated Sequence and a Targeted Toxin-Based Selection System.

The CRISPR/Cas9 system has enabled the editing of mammalian genomes; however, its applicability and efficiency in the pig genome has not been studied in depth. The α-gal epitope synthesized by α-1,3-galactosyltransferase gene (GGTA1) is known as a xenoantigen obtained upon pig-to-human xenotransplantation. We here employed the CRISPR/Cas9 system-mediated knock-in of endogenous GGTA1 via targeted homologous recombination (HR). Linearized donors with ~800-bp homology flanking the CRISPR/Cas9 target site [exon 4 (containing ATG) of GGTA1] served as a template for gene targeting by HR. Using a targeted toxin strategy to select clones lacking α-gal epitope expression, we successfully obtained several knock-in clones within 3 weeks of initial transfection. These results suggest that the use of CRISPR/Cas9-mediated HR to knock-in a mutated fragment at defined loci represents an efficient strategy to achieve the rapid modulation of genes of interest in swine cells and is a promising tool for the creation of KO piglets.

Sevoflurane suppresses tumour necrosis factor-α-induced inflammatory responses in small airway epithelial cells after anoxia/reoxygenation.

BACKGROUND: Lung ischaemia-reperfusion (I/R) injury is correlated with poor clinical outcome. The inflammatory cytokines interleukin (IL)-6, IL-8, and monocyte chemotactic protein-1 (MCP-1) are produced by pulmonary epithelial cells during lung transplantation and are considered to be involved in I/R injury. The volatile anaesthetic sevoflurane has been shown to exert a protective effect on I/R injury in various organs. We investigated the effect of sevoflurane on the inflammatory functions of pulmonary epithelial cells in vitro. METHODS: Human normal small airway epithelial cells (SAEC) were incubated under anoxic conditions for 24 h with or without sevoflurane and then stimulated with tumour necrosis factor (TNF)-α under hyperoxic conditions for 5 h with or without sevoflurane. After incubation, IL-6, IL-8, and MCP-1 mRNA expression was analysed by quantitative real-time RT-PCR. The production of IL-6, IL-8, and MCP-1 was assayed by enzyme-linked immunosorbent assay, the effects of sevoflurane on inflammatory gene expression were examined by DNA microarray analysis, and the effects of sevoflurane on NF-κB-mediated inflammatory cytokine production were examined by immunoblotting. RESULTS: Sevoflurane suppressed TNF-α-induced IL-6, IL-8, and MCP-1 gene expression and the production of IL-6 and IL-8 in SAEC under anoxia/reoxygenation conditions. DNA microarray analysis indicated that sevoflurane modulated NF-κB-related gene expression. Sevoflurane significantly inhibited TNF-α-induced translocation of p65 NF-κB into the nucleus. Sevoflurane enhanced TNF-α-induced gene expression of inhibitor κB (IκB) but not of NF-κB. CONCLUSIONS: Sevoflurane suppressed the NF-κB-mediated production of pulmonary epithelial cell-derived inflammatory cytokines, including IL-6 and IL-8, which are capable of causing I/R injury.

Association between mouth opening and upper body movement with intake of different-size food pieces during eating.

Head rotation is coordinated with mandibular movement during mouth opening, and the range of head rotation and mouth opening change with food size. However, past research did not include upper body movement, and no reports have related head and mandibular movement during realistic eating. The purpose of this study was to analyse head and mandibular movements with intake of different-sized food pieces during realistic eating. The test food consisted of apple cut into two different cube sizes (10mm and 20mm). Head and mandibular movements of 20 healthy young adults eating the apple pieces were simultaneously recorded in three dimensions by a wireless opto-electronic system. Reflective markers were attached to the upper lip and chin to measure the mouth opening range. Five markers were attached to eyeglasses frames to measure linear motion and rotation of the head. One marker was attached to the jugular notch of the sternum to measure linear motion of the upper body. Linear motion, and the inclination angle of the head and upper body, and mouth opening range were compared during intake of different-sized apple pieces. Mouth opening, head-neck rotation angle and the amount of upper body forward translation and inclination increased with larger apple pieces. However, isolated relative head motion was stabilized. We conclude that upper body forward motion and head-neck rotation assist mouth opening whilst stabilizing head orientation, and that the range of head-neck rotation angle, upper body translation and range of mouth opening change with food size during realistic eating.

Head motion may help mouth opening in children.

Concomitant head and mandibular movement during jaw function is well known in adults; however, its importance in children has not been studied. The brain attains 85-90% of its adult weight at 5 years of age, though the maximum rate of condylar growth is attained at approximately 14 years of age. These findings suggest that the coordination of the head and mandible may differ between children and adults. This study investigated head and mandibular movements of 19 children with complete primary dentition (average age: 5 years 5 months) and compared their functional integration of jaw and head movements to those of 16 female adults (average age: 20 years 3 months) with permanent dentition. Although the mandibular opening distance was significantly greater in the adults, the magnitude of concomitant head motion was greater in children. The results suggest that head extension in children helps increase the magnitude of mouth opening more than in adult women.

[Atrial pacing with the A-V paceport pulmonary artery catheter].

Atrial pacing is often necessary during cardiac surgery. A total of 20 patients undergoing cardiac surgery were atrially paced with either a multipurpose pulmonary artery catheter (PAC) or an A-V paceport PAC (n = 10 each). Atrial pacing was successful in all the patients before cardiopulmonary bypass. The output threshold was 4.2 +/- 0.7 mA for a multipurpose PAC and 3.8 +/- 0.7 mA for A-V paceport PAC. Atrial pacing with both PAC's was readily performed and useful during cardiac surgery.

Effect of nicardipine and diltiazem on internal carotid artery blood flow velocity and local cerebral blood flow during cerebral aneurysm surgery for subarachnoid hemorrhage.

STUDY OBJECTIVE: To determine the hemodynamic effects of a bolus injection of nicardipine 1 mg or diltiazem 5 mg on local cerebral blood flow (LCBF) and internal carotid blood flow velocity (ICBFV) with isoflurane anesthesia. DESIGN: Randomized study. SETTING: Inpatient neurosurgery and anesthesia clinic at a city hospital. PATIENTS: 26 patients with subarachnoid hemorrhage who were scheduled for cerebral aneurysm clipping. INTERVENTIONS: A bolus injection of either nicardipine or diltiazem was administered to patients whose systolic blood pressure increased to over 150 mmHg after opening of the dura. MEASUREMENTS AND MAIN RESULTS: After the bolus injection, both drugs rapidly decreased arterial blood pressure. Nicardipine increased LCBF [before injection, 42.1 +/- 12.3 ml/100 g/min; after injection, 47 +/- 10.7 ml/100g/min; (p < 0.05 vs control); after recovery, 42.4 +/- 11.1 cm/sec], but diltiazem did not change LCBF. Nicardipine 1 mg moderately increased ICBFV [before injection, 34.2 +/- 9.3 cm/sec; after injection, 40.6 +/- 8.7 cm/sec (p < 0.01 vs. control); after recovery, 34.1 +/- 8.9 cm/sec], but diltiazem did not change ICBFV. In addition, venous partial oxygen pressure and saturation of the internal jugular did not change throughout the study. There was a close correlation between presurgical neurologic status and LCBF (rs = -0.743; p < 0.01) and ICBFV (rs = -0.721; p < 0.01). CONCLUSIONS: Nicardipine increased LCBF and ICBFV, but diltiazem did not change either. These results suggest that both drugs are useful and safe for the treatment of intraoperative hypertension during cerebral aneurysm surgery.

Nitrous oxide does not depress left ventricular contractility in ischemic rat heart.

The direct effects of nitrous oxide on left ventricular contractility and myocardial oxygen consumption (MVO2) in the ischemic isolated rat heart were studied. The rat heart was isolated and perfused by a Langendorf technique. The aortic stump was cannulated and the heart was perfused with Kumpeis solution bubbled with 95% O2 and 5% CO2 (control phase). A latex balloon was inserted into the left ventricle (LV) to measure LV pressures and dP/dt. Coronary flow was measured and MVO2 was calculated. After the control phase, perfusion pressure was decreased to induce global ischemia (ischemic phase). There were four groups of eight hearts each: control, nitrogen, nitrous oxide, and halothane groups. After 15 min of ischemic phase, the perfusion pressure was increased and the gas mixture was changed to the standard gas mixture (reperfusion phase). Nitrous oxide did not further depress myocardial contractility compared with nitrogen in the ischemic phase, and did not alter MVO2 in the ischemic phase compared with nitrogen. Halothane significantly depressed myocardial contractility and decreased MVO2 in the ischemic phase compared with the control.

Blood coagulation and autologous blood transfusion in cardiac surgery.

STUDY OBJECTIVE: To review the basic pathophysiology of altered coagulation associated with cardiopulmonary bypass and autologous blood transfusion in cardiac surgery. DESIGN: Review of rational use of heparin, mechanisms and treatment of coagulation disorders, and autologous blood transfusion. SETTING: Cardiac surgery in community and academic hospitals. PATIENTS: Adult cardiac surgical patients. MAIN RESULTS: Heparin is most commonly used for anticoagulation during cardiopulmonary bypass. Although activated clotting time is widely used to assess heparin-induced anticoagulation, the minimum time to prevent clotting during cardiopulmonary bypass remains unclear. Activated clotting time is affected by many factors other than heparin, such as antithrombin III, blood temperature, platelet count, and age. The rational use of activated clotting time still must be defined. The frequency of abnormal bleeding after cardiopulmonary bypass is significant. Although inadequate surgical hemostasis is the most frequent cause of bleeding, altered coagulation often is present. A decreased number of functional platelets is one of the important causes of bleeding diathesis. Platelet dysfunction is induced by perioperative medication such as aspirin. Cardiopulmonary bypass decreases functional platelets by degranulation, fragmentation, and loss of fibrinogen receptors. Medications such as prostacyclin and iloprost may be useful to protect these platelets. Desmopressin increases factor VIII:C and von Willebrand's factor, leading to a decrease in bleeding time. Desmopressin may be useful to decrease blood loss in repeat cardiac operations, complex cardiac surgery, and abnormal postoperative bleeding. Patients undergoing coronary artery bypass grafting immediately after streptokinase infusion also are at risk for abnormal bleeding. Transfusion of fresh-frozen plasma and cryoprecipitate may be necessary. Autologous blood transfusion is cost-effective and the safest way to avoid or decrease homologous blood transfusion. Predonation, intraoperative salvage, and postoperative salvage are encouraged. Erythropoietin may be useful in increasing the amount of predonation red cells. CONCLUSIONS: Coagulation disorders in cardiac surgery are caused by many factors, such as heparin, platelet dysfunction, and fibrinolysis. Rational use of blood component therapy and medications such as heparin, protamine, and desmopressin are mandatory. Autologous blood transfusion is very useful in decreasing or obviating the use of homologous blood transfusion.

[Usefulness and limitations of transesophageal echocardiography in anesthetic practice].

Transesophageal echocardiography (TEE) has been used as a monitor of cardiovascular function and as a diagnostic tool in anesthetic practice. TEE is the only available monitor to detect anatomical abnormalities such as of wall motion as well as valvular abnormalities. Doppler TEE has wider diagnostic functions. TEE is a very sensitive monitor to detect myocardial ischemia by recognizing wall motion abnormalities and loss of systolic wall thickening. Preload defined by left ventricular end-diastolic volume may not correlate with left ventricular end-diastolic pressure or pulmonary capillary wedge pressure (PCWP) when left ventricular compliance changes such as after coronary artery surgery. PCWP can be misleading when transmural pressure across cardiac chambers are undetermined such as in patients with cardiac tamponade or those on high positive end-expiratory pressure. In these situations, TEE is a powerful tool to link physiologic parameters and anatomy. TEE is also a very sensitive monitor to diagnose air embolism during cardiac surgery and neurosurgery in sitting position. There are, however, several shortcomings such as its cost, "too much sensitivity", requirement of some experience, interobserver variability, and so on. The computer-assisted on-line analysis would greatly augment usefulness of TEE. When these shortcomings are overcome, TEE would be one of the most important monitors in anesthetic practice.

Effect of labetalol or lidocaine on the hemodynamic response to intubation: a controlled randomized double-blind study.

Labetalol, a combined alpha 1- and nonselective beta-adrenergic blocking drug, was compared to lidocaine or saline to minimize the hypertensive and tachycardic response to intubation in a controlled randomized double-blind study in patients undergoing surgical procedures under general anesthesia. Forty adult patients were divided into four groups of 10 each: placebo (saline), lidocaine 100 mg, labetalol 5 mg, or labetalol 10 mg. The double-blind preparation was administered as an IV bolus just prior to induction and 2 min before the stimulus of laryngoscopy and intubation. Heart rate and blood pressure were measured at 1-min intervals for 2 min prior to induction of anesthesia and through 6 min following induction of anesthesia. Labetalol 10 mg prevented a rise in heart rate after intubation compared to patients who received placebo, lidocaine 100 mg, or labetalol 5 mg. The hypertensive response to intubation was similar in all four groups. Labetalol 10 mg IV just prior to induction of anesthesia is a safe and cost-effective means of preventing tachycardia but not hypertension in response to laryngoscopy and intubation.