Clinical clerkship students' preferences and satisfaction regarding online lectures during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has caused an unprecedented disruption in medical education. Students and lecturers had to adapt to online education. The current study aimed to investigate the level of satisfaction and future preference for online lectures among clinical clerkship students and elucidated the factors that affect these outcomes. METHODS: We selected a sample of 114 medical students undergoing clinical clerkship during the COVID-19 pandemic. We conducted onsite lectures before the pandemic and online lectures after the outbreak. A survey was conducted, and the sample included students and 17 lecturers. The average scores of total satisfaction and future preference related to online lectures were computed. RESULTS: Students' scores on total satisfaction with online lectures and their future preference were higher than those for onsite lectures. Scores on the ease of debating dimension were low and those on accessibility of lectures in online lectures were higher than those in onsite lectures. There was no difference between the two groups in the scores on the comprehensibility and ease of asking questions dimensions. Results of the multiple regression analysis revealed that accessibility determined total satisfaction, and future preference was determined by comprehensibility as well as accessibility. Contrary to students' future preferences, lecturers favored onsite lectures to online ones. CONCLUSION: Online lectures are an acceptable mode of teaching during the COVID-19 pandemic for students undergoing clinical clerkship. Online lectures are expected to become more pervasive to avoid the spread of COVID-19.

Clinically relevant concentration of propofol and benzodiazepines did not affect in vitro angiogenesis.

PURPOSE: Angiogenesis, one of regenerative medicine, is essential in the process of wound healing. The detailed effects of intravenous anesthetics and sedatives used during perioperative period have not yet been clarified. We investigated the effects of benzodiazepines and propofol on in vitro capillary tube formation. METHODS: The effects of midazolam, diazepam and propofol (1, 10, 50 µM each) on proliferation of human umbilical vein endothelial cells (HUVEC) and normal human diploid fibroblasts (NHDF) were determined. Quantitation of migration was achieved by measuring the fluorescence of migrating HUVEC using angiogenesis system. The effects of midazolam, diazepam and propofol on in vitro angiogenesis were investigated in co-cultured HUVEC and NHDF incubated. The effects of midazolam on activation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases were examined by Western blot analysis using phospho-specific antibodies. Parametric data were analyzed with one-way repeated measures analysis of variance followed by the Scheffé test. A value of P < 0.05 was considered statistically significant. RESULTS: Fifty µM of midazolam significantly impaired endothelial cell proliferation, migration, and in vitro capillary tube formation. Propofol, diazepam or lower dose midazolam did not show any enhancing or suppressive effects on in vitro angiogenesis. Fifty µM of midazolam remarkably activated ERK, but not p38 MAPK in HUVEC. CONCLUSION: Propofol and benzodiazepines except high-dose midazolam did not affect in vitro angiogenesis. High-dose midazolam may impair in vitro capillary tube formation due to by suppressing proliferation and migration of endothelial cells via activation of ERK.

Cytoskeleton-disrupting agent cytochalasin B reduces oxidative stress caused by high glucose in the human arterial smooth muscle.

The role of cytoskeleton dynamics in the oxidative stress toward human vasculature has been unclear. The current study examined whether the cytoskeleton-disrupting agent cytochalasin B reduces oxidative stress caused by high glucose in the human arterial smooth muscle. All experiments in the human omental arteries without endothelium or the cultured human coronary artery smooth muscle cells were performed in d-glucose (5.5 mmol/L). The exposure toward d-glucose (20 mmol/L) for 60 min reduced the relaxation or hyperpolarization to an ATP sensitive K+ channel (KATP) opener levcromakalim (10-8 to 3 × 10-6 mol/L and 3 × 10-6 mol/L, respectively). Cytochalasin B and a superoxide inhibitor Tiron, restored them similarly. Cytochalasin B reduced the NADPH oxidase activity, leading to a decrease in superoxide levels of the arteries treated with high d-glucose. Also, cytochalasin B impaired the F-actin constitution and the membrane translocation of an NADPH oxidase subunit p47phox in artery smooth muscle cells treated with high d-glucose. A clinical concentration of cytochalasin B prevented human vascular smooth muscle malfunction via the oxidative stress caused by high glucose. Regulation of the cytoskeleton may be essential to keep the normal vascular function in patients with hyperglycemia.

Accuracy and reliability of continuous blood glucose monitoring during pediatric cardiopulmonary bypass.

The purpose of this study was to assess the accuracy and reliability of a continuous blood glucose monitoring system (artificial endocrine pancreas; STG-55, Nikkiso, Tokyo, Japan) during pediatric cardiopulmonary bypass surgery. Twenty-five pediatric patients scheduled to undergo cardiovascular surgery with cardiopulmonary bypass (age 4 months to 11 years; body weight 5.6-59.7 kg) were enrolled. The glucose sensor line of the artificial endocrine pancreas was connected to the venous side of the cardiopulmonary bypass circuit and used for continuous blood glucose monitoring. We obtained 192 samples for blood gas assessment from the cardiopulmonary bypass circuit, and i-STAT (Abbott, East Windsor, NJ, USA) was used for conventional blood glucose assessment. The accuracies of continuous glucose measurements (STG-55) and conventional intermittent glucose measurements (i-STAT) during cardiopulmonary bypass were compared by means of Clarke error grid analysis. The results were divided into five zones, A, B, C, D, and E, and 78.6% of paired measurements were in zone A, while 21.4% were in zone B. We confirmed that the results of this continuous blood glucose monitoring system for cardiopulmonary bypass during pediatric cardiovascular surgery were highly reliable. An artificial endocrine pancreas may facilitate the safe use of intensive insulin therapy during pediatric cardiovascular surgery.

Involvement of superoxide generated by NADPH oxidase in the shedding of procoagulant vesicles from human monocytic cells exposed to bupivacaine.

It is known that a variety of sized procoagulant vesicles that express tissue factor are released from several types of cells including monocytes by mechanisms related to the induction of apoptosis, while it has not yet been evaluated whether superoxide is involved in the production of such vesicles. Here, we report that a local anesthetic bupivacaine induces apoptosis in human monocytic cells THP-1 within a short observation period, where the shedding of procoagulant vesicles is associated. The property as procoagulant vesicles was evaluated using flow cytometry by the binding of FITC-conjugated fibrinogen to vesicles in the presence of fresh frozen plasma and the suppression of this binding by heparin. Bupivacaine (1 mg/ml) increased the apoptotic cells and procoagulant vesicles. LY294002 (100 µM), that inhibits the recruiting of intracellular component of NADPH oxidase to construct the activated form of this enzyme complex, or superoxide dismutase (1500 unit/ml) suppressed bupivacaine-provoked induction of apoptosis and the increase of procoagulant vesicles. We suggest that this simple experimental system is useful to explore the molecular mechanisms of action of superoxide in the shedding of procoagulant vesicles from human monocytic cells.

Strict blood glucose control by an artificial endocrine pancreas during hepatectomy may prevent postoperative acute kidney injury.

The aim of the present study was to evaluate the usefulness of a closed-loop system (STG-55; Nikkiso, Tokyo, Japan), a type of artificial endocrine pancreas for the continuous monitoring and control of intraoperative blood glucose, for preventing postoperative acute kidney injury (AKI) in patients undergoing hepatectomy. Thirty-eight patients were enrolled in this study. Glucose concentrations were controlled with either a manual injection of insulin based on a commonly used sliding scale (manual insulin group, n = 19) or the programmed infusion of insulin determined by the control algorithm of the artificial endocrine pancreas (programmed insulin group, n = 19). After the induction of anesthesia, a 20-G intravenous catheter was inserted into the peripheral forearm vein of patients in the programmed insulin group and connected to an artificial endocrine pancreas (STG-55). The target range for glucose concentrations was set to 100-150 mg/dL. The mean serum creatinine concentrations of preoperative, postoperative 24 and 48 h were 0.72, 0.78, and 0.79 mg/dL in the programmed insulin group, and 0.81, 0.95, and 1.03 mg/dL in the manual insulin group, respectively. Elevations in serum creatinine concentrations postoperative 48 h were significantly suppressed in the programmed insulin group. The STG-55 closed-loop system was effective for maintaining strict blood glucose control during hepatectomy with minimal variability in blood glucose concentrations and for suppressing elevations in serum creatinine concentrations. Strict blood glucose control by an artificial endocrine pancreas during hepatectomy may prevent postoperative AKI.

Cuffed oropharyngeal airway for difficult airway management.

Difficulties with airway management are often caused by anatomic abnormalities due to previous oral surgery. We performed general anesthesia for a patient who had undergone several operations such as hemisection of the mandible and reconstructive surgery with a deltopectoralis flap, resulting in severe maxillofacial deformation. This made it impossible to ventilate with a face mask and to intubate in the normal way. An attempt at oral awake intubation using fiberoptic bronchoscopy was unsuccessful because of severe anatomical abnormality of the neck. We therefore decided to perform retrograde intubation and selected the cuffed oropharyngeal airway (COPA) for airway management. We inserted the COPA, not through the patient's mouth but through the abnormal oropharyngeal space. Retrograde nasal intubation was accomplished with controlled ventilation through the COPA, which proved to be very useful for this difficult airway management during tracheal intubation even though the method was unusual.

Novel blood sampling method of an artificial endocrine pancreas via the cardiopulmonary bypass circuit.

We tried to perform continuous blood glucose monitoring during cardiovascular surgery involving cardiopulmonary bypass using an artificial endocrine pancreas (STG-22 or -55; Nikkiso, Tokyo, Japan); however, we often encountered problems during these procedures because insufficient blood was obtained for monitoring. Thus, we started performing the blood sampling via the venous side of the cardiopulmonary bypass circuit. As a result, continuous blood glucose monitoring using an artificial endocrine pancreas was proven to be stable and reliable during cardiovascular surgery involving cardiopulmonary bypass.

Pronounced QT Prolongation During General Anesthesia in a Child with Left Ventricular Noncompaction Cardiomyopathy: A Case Report.

We report the case of an 8-year-old boy with left ventricular noncompaction cardiomyopathy (LVNC) and QT prolongation who experienced further prolongation of the QTc during general anesthesia for extraction of a maxillary mesiodens. Pronounced prolongation of the QTc was observed after induction of general anesthesia with thiamylal and during emergence. No notable fluctuations in blood pressure, heart rate, and estimated continuous cardiac output were observed. We considered it likely that the QT prolongation was triggered by thiamylal and increased sympathetic nervous system activity. During general anesthesia for children with LVNC and QT prolongation, it is necessary to monitor intraoperative hemodynamic fluctuations and prepare for the possible occurrence of arrhythmias.

Isoflurane pretreatment preserves adenosine triphosphate-sensitive K(+) channel function in the human artery exposed to oxidative stress caused by high glucose levels.

BACKGROUND: Adenosine triphosphate (ATP)-sensitive K(+) channels contribute to significant regulatory mechanisms related to organ blood flow in both physiological and pathological conditions. High glucose impairs arterial ATP-sensitive K(+) channel activity via superoxide production. However, the effects of anesthetics on this pathological process have not been evaluated in humans. In the present study, we investigated whether pretreatment with the volatile anesthetic isoflurane preserves ATP-sensitive K(+) channel activity in the human artery exposed to oxidative stress caused by high glucose. METHODS: All experiments were performed using human omental arteries without endothelium in the presence of d-glucose (5.5 mmol/L). Some arteries were treated with isoflurane (1.15% or 2.3%) in combination with d- or l-glucose (20 mmol/L) for 60 minutes, and then only isoflurane was discontinued. Relaxation and hyperpolarization of arterial segments in response to an ATP-sensitive K(+) channel opener levcromakalim were evaluated using the isometric force recording or electrophysiological study, respectively. Superoxide production was determined by dihydroethidium fluorescence. Immunohistochemical analysis for a subunit of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase p47phox was performed. Data were evaluated using repeated-measures analysis of variance or a factorial analysis of variance as appropriate, followed by Scheffé test. RESULTS: The ATP-sensitive K(+) channel antagonist glibenclamide (10(-6) mol/L) abolished relaxation induced by cumulative addition of levcromakalim (10(-8) to 10(-5) mol/L) in arteries treated with l-glucose (20 mmol/L). Incubation with d-glucose (20 mmol/L) impaired the vasorelaxation induced by levcromakalim. The selective NADPH oxidase NOX2 inhibitor gp91ds-tat (10(-6) mol/L) and pretreatment with isoflurane (1.15% and 2.3%) restored relaxation in response to levcromakalim in arteries treated with d-glucose (20 mmol/L). Isoflurane (2.3%), gp91ds-tat (10(-6) mol/L), and their combination similarly restored hyperpolarization in response to levcromakalim (3 × 10(-6) mol/L) in arteries treated with d-glucose (20 mmol/L). Along with these results, isoflurane (2.3%) reduced superoxide production and the intracellular mobilization of the cytosolic NOX2 subunit p47phox toward smooth muscle cell membrane in arteries treated with d-glucose (20 mmol/L). CONCLUSIONS: We have demonstrated for the first time a beneficial effect from the pretreatment with isoflurane on the isolated human artery. Pretreatment with isoflurane preserves ATP-sensitive K(+) channel activity in the human omental artery exposed to oxidative stress induced by high glucose, whereas the effect seems to be mediated by NADPH oxidase inhibition. Volatile anesthetics may protect human visceral arteries from malfunction caused by oxidative stress.

[Principles, usefulness, and limitations of recent circulatory monitoring].

Less invasive measuring procedures for hemodynamic status and function are increasingly being used. Surgical patients are frequently undifferentiated, need accurate risk assessment and stratification, while their need for diagnosis and therapy is often time-critical. Valid, less invasive hemodynamic monitoring modalities are essential to differentiate high- from low-risk patients, and for goal-directed management. Pulmonary artery catheters, transesophageal echocardiography, pressure pulse waveform analysis, and other less invasive monitoring techniques all are potentially effective for diagnosis and hemodynamic monitoring. This article provides information on the usefulness and limitations of recent circulatory monitoring procedures.

[Dextran-induced anaphylactic shock during general anesthesia: a case report].

We describe a case of dextran-induced anaphylactic shock during general anesthesia. A 34-year-old woman was scheduled for partial hepatic resection under general anesthesia. General anesthesia was induced with intravenous remifentanil, thiamylal and rocuronium, and was maintained with oxygen, air, sevoflurane and remifentanil. The patient developed hypotension (from 90/50 to 49/27 mmHg in 20 min) together with tachycardia (111 beats x min(-1)) and desaturation (83%) subsequent to intravenous infusion of Saviosol (dextran 40). We made a diagnosis of anaphylactic shock on the basis of clinical manifestations and administered adrenaline and hydrocortisone. The patient's blood pressure and oxygen saturation immediately improved, and the operation was resumed. No postoperative complications were evident, and the postoperative course was uneventful. Although low molecular weight dextran is often used as plasma expander or to prevent thromboembolism, it can cause severe hypotension or bronchospasm during general anesthesia.

Total Intravenous Anesthesia Using Remimazolam and Continuous Cardiac Output Monitoring for Dental Anesthesia in a Patient With Takayasu's Arteritis: A Case Report.

Takayasu's arteritis is a persistent chronic progressive inflammation of the large- and medium-caliber arteries. Controlling cardiovascular variability during anesthesia and overcoming difficulties of cardiovascular monitoring due to the impaired vessels are important in patients with Takayasu's arteritis. Remimazolam is a novel short-acting benzodiazepine with mild effects on hemodynamics. We report the case of a patient with Takayasu's arteritis who underwent oral surgery under general anesthesia. This report highlights the use of remimazolam and remifentanil to reduce hemodynamic perturbations using estimated continuous cardiac output monitoring.

Molecular mechanisms of the inhibitory effects of clonidine on vascular adenosine triphosphate-sensitive potassium channels.

BACKGROUND: We investigated the effects of the imidazoline-derived α2-adrenoceptor agonist clonidine on vascular adenosine triphosphate-sensitive potassium (K(ATP)) channel activity in rat vascular smooth muscle cells and recombinant vascular K(ATP) channels transiently expressed in COS-7 cells. METHODS: Using the patch-clamp method, we investigated the effects of clonidine on the following: (1) native vascular K(ATP) channels; (2) recombinant K(ATP) channels with different combinations of various types of inwardly rectifying potassium channel (Kir6.0 family: Kir6.1, 6.2) and sulfonylurea receptor (SUR1, 2A, 2B) subunits; (3) SUR-deficient channels derived from a truncated isoform of the Kir6.2 subunit (Kir6.2ΔC36 channels); and (4) mutant Kir6.2ΔC36 channels with diminished sensitivity to ATP (Kir6.2ΔC36-K185Q channels). RESULTS: Clonidine (≥3 × 10(-8) M) inhibited native K(ATP) channel activity in cell-attached configurations with a half-maximal inhibitory concentration value of 1.21 × 10(-6) M and in inside-out configurations with a half-maximal inhibitory concentration value of 0.89 × 10(-6) M. With similar potency, clonidine (10(-6) or 10(-3) M) also inhibited the activities of various recombinant SUR/Kir6.0 K(ATP) channels, the Kir6.2ΔC36 channel, and the Kir6.2ΔC36-K185Q channel. CONCLUSIONS: Clinically relevant concentrations of clonidine inhibit K(ATP) channel activity in vascular smooth muscle cells. This inhibition seems to be the result of its effect on the Kir6.0 subunit and not on the SUR subunit.

[Torsade de pointes associated with severe bradycardia after induction of general anesthesia].

An 80-year-old woman with chronic atrial flutter/fibrillation, and chronic renal failure underwent ileocecal resection. The preoperative electrocadiogram showed normal QT interval. Temporary pacemaker catheter was inserted for sinus arrest (5-6 sec) the day before operation. Anesthesia was induced with remifentanil 0.5 micro x kg(-1) min(-1), thiamylal 125 mg, and rocuronium 30 mg after intravenous atropine sulfate 0.5 mg. Because the heart rate was increased with atropine sulfate, the pacemaker was not started. Anesthesia was then maintained with intravenous remifentanil and sevoflurane-air-oxygen. Just after induction of anesthesia, sinus bradycardia occurred, and 9 minutes after tracheal intubation, ECG suddenly showed torsade de pointes (TdP) and the arterial blood pressure decreased leading to asystole. We immediately started cardiopulmonary resuscitation, and TdP stopped spontaneously within 1 minute. We started pacemaker (VVI, 60 beats x min(-1)) and intravenous injection of lidocaine, and TdP did not recur. In this case, TdP seemed to have occurred because of bradycardia-induced abnormal QT prolongation. This should be considered the risk of lethal arrhythmia in patients with severe bradycardia including TdP.

Human Vascular Smooth Muscle Function and Oxidative Stress Induced by NADPH Oxidase with the Clinical Implications.

Among reactive oxygen species, superoxide mediates the critical vascular redox signaling, resulting in the regulation of the human cardiovascular system. The reduced form of nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase, NOX) is the source of superoxide and relates to the crucial intracellular pathology and physiology of vascular smooth muscle cells, including contraction, proliferation, apoptosis, and inflammatory response. Human vascular smooth muscle cells express NOX1, 2, 4, and 5 in physiological and pathological conditions, and those enzymes play roles in most cardiovascular disorders caused by hypertension, diabetes, inflammation, and arteriosclerosis. Various physiologically active substances, including angiotensin II, stimulate NOX via the cytosolic subunits' translocation toward the vascular smooth muscle cell membrane. As we have shown, some pathological stimuli such as high glucose augment the enzymatic activity mediated by the phosphatidylinositol 3-kinase-Akt pathway, resulting in the membrane translocation of cytosolic subunits of NOXs. This review highlights and details the roles of human vascular smooth muscle NOXs in the pathophysiology and clinical aspects. The regulation of the enzyme expressed in the vascular smooth muscle cells may lead to the prevention and treatment of human cardiovascular diseases.