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Sevoflurane is associated with a high incidence of emergence agitation in children. Midazolam and propofol have been examined with the aim of reducing emergence agitation after sevoflurane anaesthesia. However the effect of both drugs on emergence agitation is still controversial. Therefore we designed this study to measure the effect of midazolam or propofol at the end of surgery on emergence agitation during the recovery period. One hundred and one children, aged one to 13 years, undergoing strabismus surgery were enrolled in this randomised double-blind study. Anaesthesia was induced and maintained with sevoflurane in N2O/O2. Children were randomly assigned to receive midazolam 0.05 mg/kg (group M, n = 35), propofol 1 mg/kg (group P, n = 31) or saline (group S, n = 35). A four-point scale was used to evaluate recovery characteristics upon awakening and during the first hour after emergence from anaesthesia. The incidence of emergence agitation in group M was 42.9% (15/35), in group P 48.4% (15/31) and in group S 74.3% (26/35). The incidence of emergence agitation in groups M and P was significantly less than in group S. The emergence time was prolonged for patients in groups M and P compared to group S. There was no significant difference in the incidence of emergence agitation or in emergence times between the groups P and M. We conclude that propofol or midazolam administration before the end of surgery may be effective in reducing the incidence of emergence agitation in children undergoing strabismus surgery under sevoflurane anaesthesia. [ABSTRACT FROM AUTHOR]

Several studies have been conducted to evaluate the utilisation of the operating room, a fixed resource, in terms of conditions that prevent day-of-surgery cancellation due to deficient operative capacity. In this study, we surveyed the causes and overall rates of elective surgery cancellation and then compared the number of cancellations that occurred before and after the installation of additional operating rooms. We surveyed all patients undergoing elective surgery for 100 days prior to and after the installation of additional operating rooms. The causes for cancellations were divided into six categories: departmental issues, abnormal laboratory results, patient denial, inadequate preparation, over-booking and other issues. The departmental causes were further divided into four categories: ward overflow, scheduling date errors, unavailable surgeons and other issues. The number of overall cancelled cases and scheduled cases increased following the increase in operating room capacity, although this increase was not statistically significant. However; the cancellation ratio rose significantly after the operating room capacity was increased. The primary reasons for cancellation prior to the increase in operating room capacity were departmental issues, over-booking and abnormal laboratory data, in that order. After the operating room capacity was increased, the primary reasons for cancellation were departmental issues, abnormal laboratory data and over-booking, in that order Taken together the results of this study indicate that increased operating room capacity can prevent cancellation due to over-booking. However; the numbers of cancellations due to ward overflow exceeded the numbers of cancellations that occurred as a result of over-booking. In conclusion, increasing the operating room capacity is not an appropriate option for preventing the cancellation of operations. [ABSTRACT FROM AUTHOR]

Background and Objectives: This study examined the effect of lumbar flexion on the extent of the epidural block during lumbar epidural anesthesia.Methods: The epidural catheter was introduced at the L3-4 interspace with the patient in the lateral decubitus position with the surgical side down. After administering a test drug (3 mL of 2% lidocaine and 15 mug of epinephrine), the patients were randomly allocated to 1 of 2 groups: Group F (n = 16, lumbar spine flexed) and Group N (n = 17, lumbar spine in the neutral position). In both groups, 2% lidocaine (16 mL) mixed with sodium bicarbonate (2 mL) was administered through the epidural catheter while the patient maintained the lateral decubitus position with the lumbar spine either flexed or in the neutral position. All the patients maintained their respective positions for 5 minutes and were subsequently turned to the supine position. The pinprick block level and the degree of motor blockade were assessed every 10 minutes for 60 minutes after administering the local anesthetics. A 2-dermatomal difference in uppermost block between groups was determined to be clinically significant.Results: The median difference between groups in the uppermost pinprick block level was only 1.5 dermatomes and it did not satisfy our criteria for clinical significance. There were no significant differences between the 2 groups in the lowermost pinprick block level and the degree of motor block.Conclusions: Lumbar flexion has no clinically relevant effect on sensory spread during epidural anesthesia. [ABSTRACT FROM AUTHOR]

Air pollution and heavy metal exposure are emerging public health concerns. Prenatal exposure to air pollutants and heavy metals has been implicated in the development of congenital heart disease (CHD). However, the relationship between exposure to airborne heavy metals and CHD has not yet been investigated. Therefore, in this large population-based study, we investigated the association between air pollutants, including airborne heavy metals, and the risk of CHD using national health insurance claims data from South Korea. Data regarding 1,129,442 newborns and their mothers were matched with air pollutant levels during the first 8 weeks of gestation. In the five-air pollutant model, we found significant positive correlations between prenatal exposure to sulfur dioxide (SO 2 ; odds ratio [OR] 6.843, 95% confidence interval [CI] 5.746-8.149) and cadmium (Cd; OR 1.513, 95% CI 1.187-1.930) and the risk of ventricular septal defects in newborns. This study highlights the association between prenatal exposure to air pollutants, including airborne heavy metals, and an elevated CHD risk. Further research is essential to validate and expand these findings, with the ultimate goal of enhancing public health outcomes., (© 2024. The Author(s).)

The systemic inflammatory response syndrome can occur due to an inflammatory reaction to the release of cytokines, and it has been linked to the circulation of pro- and anti-inflammatory cytokines. The cardiopulmonary bypass (CPB) system is known to activate numerous inflammatory pathways. Applying CPB in large animals for an extended period may be useful as a controlled experimental model for systemic inflammatory responses. The authors hypothesized that 0.2 mg/kg NuSepin ® would inhibit CBP-induced proinflammatory cytokine release, and attenuate CPB-induced vasoplegia. CPB was maintained for 2 h in 8 male Yorkshire pigs. Ten ml of saline was administered intravenously to the control group, while the study group received 10 ml of NuSepin ® (0.2 mg/kg), before start of CPB. Blood samples were collected at four different time points to evaluating the level of cytokine (TNF-α, IL-1β, IL-6, IL-8) release during and after CBP. All vital signals were recorded as continuous waveforms using the vital recorder ® . Our study demonstrated that IL-6 increased in both groups during CPB remained unchanged. However, in the Nusepin group, IL-6 levels rapidly decreased when CPB was stopped and the proinflammatory reaction subsided. Furthermore, the dose of norepinephrine required to maintain a mean pressure of 60 mmHg was also lower in the Nusepin group., (© 2024. The Author(s).)

Background: Gastric insufflation can cause gastric regurgitation, which may be exacerbated in patients who are expected to have difficult airways. The purpose of this study was to investigate the difference in respiratory parameters and the frequency of gastric insufflation according to the ventilation mode during the anesthestic induction on patients who were predicted to have difficult facemask ventilation., Methods: A total of eighty patients with expected airway difficulties were included. Patient were allocated to 2 groups (n = 40 each). In the manual ventilation group, ventilation was performed by putting a mask on the patient's face with 1-hand and adjusting the pressure limiting valve to 15 cm H2O. In the pressure-controlled ventilation group, a mask was held in place using 2-handed jaw-thrust maneuver. The pressure-controlled ventilation was applied and peak inspiration pressure was adjusted to achieve a tidal volume of 6 to 8 mL/kg. The primary outcome was the difference of the peak airway pressure between 2 groups every 30 seconds for 120 seconds duration of mask ventilation. We also evaluated respiratory variables including peak airway pressure, End-tidal carbon dioxide and also gastric insufflation using ultrasonography., Results: The pressure-controlled ventilation group demonstrated lower peak airway pressure than the manual ventilation group (P = .005). End-tidal carbon dioxide was higher in the pressure-controlled ventilation group (P = .012). The incidence of gastric insufflation assessed by real-time ultrasonography of the gastric antrum was higher in the manual ventilation group than in the pressure-controlled ventilation group [3 (7.5%) vs 17 (42.5%), risk ratio (95% confidence interval): 0.06 to 0.56, P = .003]., Conclusions: Pressure-controlled ventilation during facemask ventilation in patients who were expected to have difficult airways showed a lower gastric insufflation rate with low peak airway pressure compared to manual ventilation., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background and Objectives : Cerebral ischemia is one of the major preoperative complications. Dexmedetomidine is a well-known sedative-hypnotic agent that has potential organ-protective effects. We examine the miRNAs associated with preconditioning effects of dexmedetomidine in cerebral ischemia. Materials and Methods : Transient infarcts were induced in mice via reperfusion after temporary occlusion of one side of the middle cerebral artery. A subset of these mice was exposed to dexmedetomidine prior to cerebral infarction and miRNA profiling of the whole brain was performed. We administered dexmedetomidine and miRNA-323-5p mimic/inhibitor to oxygen-glucose deprivation/reoxygenation astrocytes. Additionally, we administered miR-323-5p mimic and inhibitor to mice via intracerebroventricular injection 2 h prior to induction of middle cerebral artery occlusion. Results : The infarct volume was significantly lower in the dexmedetomidine-preconditioned mice. Analysis of brain samples revealed an increased expression of five miRNAs and decreased expression of three miRNAs in the dexmedetomidine-pretreated group. The viability of cells significantly increased and expression of miR-323-5p was attenuated in the dexmedetomidine-treated oxygen-glucose deprivation/reoxygenation groups. Transfection with anti-miR-323-5p contributed to increased astrocyte viability. When miRNA-323-5p was injected intraventricularly, infarct volume was significantly reduced when preconditioned with the miR-323-5p inhibitor compared with mimic and negative control. Conclusions : Dexmedetomidine has a protective effect against transient neuronal ischemia-reperfusion injury and eight specific miRNAs were profiled. Also, miRNA-323-5p downregulation has a cell protective effect under ischemic conditions both in vivo and in vitro. Our findings suggest the potential of the miR-323-5p inhibitor as a therapeutic agent against cerebral infarction.

Patients with peripheral arterial disease (PAD) are at a higher risk of developing postoperative complications. Arachidonate 5-lipoxygenase-activating protein (ALOX5AP) plays an important role in atherosclerosis pathogenesis. In this study, the relationship between PAD and several single nucleotide polymorphisms (SNPs) of ALOX5AP (rs17216473, rs10507391, rs4769874, rs9551963, rs17222814, and rs7222842) was investigated in elderly patients undergoing general surgery. The medical records of 129 patients aged > 55 years who underwent elective general surgery between May 2018 and August 2019 were retrospectively reviewed. The A/A in rs17216473, A/A in rs10507391, G/G in rs4769874, and A/A in rs9551963 were calculated as 0 points and the rest as 1 point to define the genetic risk score. The prevalence of PAD tended to increase with higher genetic risk scores (patients had less ALOX5AP gene polymorphism of A/A in rs17216473, A/A in rs10507391, G/G in rs4769874, or A/A in rs9551963) (p = 0.005). Multivariate logistic regression analysis revealed that the genetic risk score (p = 0.009) and age (p = 0.007) were positively correlated with the prevalence of PAD. Genetic polymorphisms of ALOX5AP and age were associated with the prevalence of PAD in this study.

Background: Previous evidence has clearly shown that maintaining normothermia in children undergoing surgery is difficult and is associated with adverse outcomes. Therefore, this study aimed to retrospectively analyze the changes in body temperature over time in 2 different types of microtia reconstruction surgeries, namely, embedding, and elevation surgeries., Methods: We performed a retrospective chart review of patients who underwent microtia reconstruction (embedding and elevation) between July 2012 and February 2015 (n = 38). The changes in body temperature between the 2 types of surgeries were compared., Results: During microtia reconstruction, the body temperature in the embedding surgery group was significantly higher than that in the elevation surgery group from 1 hour after the start of surgery to 1 day after the surgery (P < .001). Time, group, and time-group interaction were associated with an increase in body temperature (P < .001) but not the warming method., Conclusion: We found an increase in body temperature in patients with microtia who underwent embedding surgery (autologous costal cartilage harvest surgery), and this was related to the type of surgery and not to the warming method. Therefore, further research is warranted to determine the cause of the increase in body temperature during this surgery., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The incidence of emergence agitation (EA) after sevoflurane anesthesia is high, especially in pediatric strabismus surgery. However, research thus far has focused on the pharmacological prophylaxis of EA and administering drugs to pediatric patients without EA is problematic. The purpose of this study was to determine whether the use of propofol after sevoflurane anesthesia affects recovery time in patients with EA., Methods: After obtaining informed written consent, 113 children (aged 2-12 years) with the American Society of Anesthesiologists physical status of I or II who underwent strabismus surgery were enrolled. Patients were divided into 2 groups; upon arrival at the postanesthetic care unit (PACU), patients who had EA (pediatric anesthesia emergence delirium [PAED] scale score ≥14) were treated with 1.0 mg/kg 1% propofol (group P: n = 30). Patients who did not have EA (PAED scale score <14, group C: n = 83) were taken care of in the PACU without propofol administration., Results: There was no difference in the PAED scale scores between the 2 groups from 10 minutes to discharge from the PACU (P > .05). There was no difference in PACU stay time between the 2 groups (P > .05)., Conclusions: We concluded that propofol administration for intense EA alleviated EA symptoms and prevented an increase in the duration of PACU stay due to EA in children undergoing strabismus surgery under sevoflurane anesthesia., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: For patients undergoing endoscopic sinus surgery, intranasal injection of epinephrine can cause acute increases in heart rate and blood pressure., Objective: Among the drugs for reducing hyperdynamic effects, dexmedetomidine and remifentanil are expected to blunt the acute hemodynamic responses after intranasal injection of epinephrine. Our study compared a difference in the 2 drugs in their abilities to blunt the hemodynamic responses in intraoperative period and postoperative profile., Methods: In this study, the patients were randomly divided into the dexmedetomidine and remifentanil groups. During the intraoperative period, the hemodynamic values were recorded. The surgical condition was assessed by a single surgeon. During the postoperative period, hemodynamic values, sedation scale score, and pain score were recorded., Result: No significant differences in hemodynamic variables were found between the groups before and after intranasal injection of epinephrine. Comparison of the group mean values before endotracheal intubation revealed that the blood pressure values in the remifentanil group were significantly lower than those in the dexmedetomidine group. At 2 minutes after endotracheal intubation, blood pressure and heart rate values in the remifentanil group were significantly lower than those in the dexmedetomidine group. The sedation score was significantly lower in the dexmedetomidine group on arrival and at 30 minutes after arrival at the postanesthetic care unit ( P  < .001 and P  = .001, respectively). At 30 and 60 minutes after the operation, the pain scores were significantly lower in the dexmedetomidine group ( P  = .015 and P  = .001, respectively)., Conclusion: Dexmedetomidine had better postoperative sedative and analgesic effects than remifentanil for patients undergoing endoscopic sinus surgery in this study. Remifentanil and dexmedetomidine attenuated acute hemodynamic responses to be within normal ranges after intranasal injection of epinephrine, and no significant differences in terms of hemodynamic variables. Remifentanil was superior to dexmedetomidine in inducing hypotension during endotracheal intubation.

Background/aim: Since pathways involving LRRC17 are related to the survival of patients with various cancers, we analyzed LRRC17 as a prognostic gene in serous ovarian cancer., Materials and Methods: Data were collected from Gene Expression Omnibus (GSE9891, GSE13876, and GSE26712) and The Cancer Genome Atlas (TCGA). We performed survival analyses using C statistics, area under the curve, survival plot with optimal cutoff level, and cox proportional regression. Zebrafish embryos were used as an in vivo model., Results: The prognosis of patients with high LRRC17 expression was poorer than that of patients with low LRRC17 expression. Multivariate regression analysis showed that LRRC17 expression, age, and stage were independently related with survival. Knockdown of lrrc17 reduced survival rate and delayed development in zebrafish embryos. We also found that lrrc17 is important for cell viability by protecting from p53-dependent apoptosis., Conclusion: LRRC17 could be a prognostic gene in ovarian cancer as it regulates cancer cell viability through the p53 pathway., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Chlorhexidine and silver sulfadiazine coated central venous catheters (CSS-CVC) may cause loss of antimicrobial efficacy due to friction between the CVC surface and sheer stress caused by the blood flow. Therefore, the aim of this study was to investigate the antibacterial efficacy of CSS-CVC at various flow rates using a bloodstream model., Methods: Each CVC was subjected to various flow rates (0.5, 1, 2, and 4 L/min) and wear-out times (0, 24, 48, 72, 96, and 120 hours), and the optical density (OD) 600 after a Staphylococcus aureus incubation test was used to determine the antibacterial effect of CSS-CVC., Results: In the 0.5 L/min group, there was no significant change in the OD600 value up to 120 hours compared with the baseline OD600 value for CSS-CVC (P > .467). However, the OD600 values of CSS-CVC in the 1 L/min (P < .001) and 2 L/min (P < .001) groups were significantly reduced up to 72 hours, while that in the 4 L/min (p < 0.001) group decreased rapidly up to 48 hours., Conclusion: This study suggests that there is a doubt whether sufficient antibacterial function can be maintained with prolonged duration of catheter placement.

Background and Objective: There are a growing number of porcine models being used for orthopaedic experiments for human beings. Therefore, pain management of those research pigs using ultrasound (US)-guided nerve block can be usefully performed. The aim of this study is to determine optimal US approaches for accessing and localizing the sciatic nerve at the midthigh level, a relevant block site for hindlimb surgery in female Yorkshire pigs., Methods: As a first step, we dissected the intubated, blood-washed out pigs (n = 3) and confirmed the anatomical position of the sciatic nerve at midthigh level. After dissection, we found the sciatic nerve, connected with nerve stimulator, and checked the dorsiflexion or plantar flexion of the hindlimb. We matched the sciatic nerve location with the US image. After the pigs were euthanized, the neural structures of the sciatic nerve were confirmed by histological examination with H&E staining. In second step, a main US-guided sciatic nerve block study was done in the intubated, live pigs (n = 8) based on the above study., Results: In lateral position, the effective US-guided nerve block site was about 6 cm from the patella crease level; immediately proximal to the bifurcation of the sciatic nerve into the tibial nerve and common peroneal nerve. The distal femur was selected as the landmark. There were no vessels or other nerves surrounding the sciatic nerve. The needle-tip was positioned less than 1 cm lateral from the distal femur and about 2 cm deep to skin. 'Donut sign' in US images was confirmed in all 16 nerves., Conclusions: Midthigh level sciatic nerve is located superficially, which enables nerve block to be easily performed using US. This is the first study to describe midthigh sciatic nerve block in the lateral position under US guidance in a porcine model from a clinical perspective., (© 2020 The Authors. Veterinary Medicine and Science Published by John Wiley & Sons Ltd.)

Objective: Drug injections and surgery are popular treatments for knee joint osteoarthritis. However, these treatments are invasive, and new noninvasive treatments with similar or better efficacy are needed. Here, we evaluated the application of 4.4 MHz of pulsed radiofrequency (PRF) as a new treatment., Methods: Acute arthritis was induced by injection of carrageenan into the intra-articular space of the knee in male rats. At 4.5 hours after arthritis induction, PRF with the treatment protocol of three seconds on and off was applied to the affected knee joint for 20 minutes. The changes in pain behavior were evaluated by comparing the peak weight load values of both hind paws at pretreatment and four, six, seven, eight, and 24 hours after treatment. And we also used Western blotting and immunohistochemistry to measure the inflammatory changes in the synovial membrane of the inflamed knee., Results: We found that the 20-minute application of PRF with the treatment protocol significantly recovered the weight load reduction at six-, seven-, and eight-hour time points after carrageenan injection. COX-2 and IL-1β levels were significantly reduced in the inflamed rats after PRF application at six and eight hours post-carrageenan injection. Immunohistochemistry showed that PRF significantly reduced inflammatory cell infiltration at six hours post-carrageenan injection., Conclusions: . Our results indicate that noninvasive PRF application inhibited pain-related behavior and decreased inflammatory cytokine expression in the inflamed knee joints of rats. Accordingly, PRF application can serve as a potential therapeutic treatment to relieve pain associated with peripheral joint/tissue damage or inflammation., (© 2019 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Tracheal intubation using a double-lumen endobronchial tube (DLT) causes postoperative sore throat., Objective: To determine the effect of two-handed jaw thrust on postoperative sore throat in patients requiring insertion of a DLT., Design: A randomised study., Setting: A tertiary teaching hospital from December 2017 to May 2018., Patients: One-hundred and six patients undergoing one-lung anaesthesia., Interventions: Patients were allocated to one of two groups (n=53 each). In the jaw thrust group, the two-handed jaw thrust manoeuvre was applied at intubation and advancement of the DLT. In the control group, conventional intubation with a sham jaw thrust was performed., Main Outcome Measures: Incidence of sore throat at 1, 6 and 24 h postoperatively., Results: The incidence of sore throat at 6 h postoperatively was higher in the control group than in the jaw thrust group [31 (59%) vs. 14 (26%), risk ratio (95% confidence interval) 0.45 (0.27 to 0.75), P < 0.01]. The overall incidence of sore throat was higher in the control group than in the jaw thrust group [35 (66%) vs. 18 (34%), risk ratio (95% confidence interval) 0.51 (0.34 to 0.78), P < 0.01]., Conclusion: The jaw thrust manoeuvre can reduce the incidence of sore throat in patients undergoing DLT insertion for one-lung ventilation., Trial Registration: ClinicalTrials.gov identifier: NCT03331809.

Introduction: The preoperative elevation of ammonia may be associated with postoperative neurologic complications. The aim of this study was to evaluate the effect of preoperative ammonia level on the incidence of delirium in patients after liver transplantation (LT)., Materials and Methods: Patients (n = 260) who received LT from January 2010 to July 2017 in a single university hospital were retrospectively reviewed. The patients' demographic data, perioperative managements, and postoperative complications were assessed. Patients were divided into the following 2 groups: those who had a preoperative elevation (Group A, n = 158) and those with a normal range (Group C, n = 102). The cut-off value for a normal serum ammonia level in our hospital was defined as 32 μg/dL., Results: After propensity score matching, there was no difference in the incidence of delirium between the groups (P = .784). Delirium occurred in 8 of 68 (11.76%) patients in Group A and 7 of 68 (10.29%) patients in Group C after LT. In addition, there was no difference in the incidence of delirium between the groups, even patients were categorized based on serum ammonia levels into 3 groups as follows: < 32 μg/dL (28/158 [17.72%]), 32 to 65 μg/dL (28/158 [17.72%]), and >65 μg/dL (28/158 [17.72%]) (P = .134)., Conclusions: The preoperative serum ammonia level was not related with the incidence of postoperative delirium. The high elevation group, especially those with greater than 65 μg/dL of preoperative ammonia, was also not related with the incidence of delirium. However, our study is limited by its retrospective design, so future prospective studies are needed., (Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.)

Various methods of assessing the depth of anesthesia (DoA) and reducing intraoperative awareness during general anesthesia have been extensively studied in anesthesiology. However, most of the DoA monitors do not include brain activity signal modeling. Here, we propose a new algorithm termed the cortical activity index (CAI) based on the brain activity signals. In this study, we enrolled 32 patients who underwent laparoscopic cholecystectomy. Raw electroencephalography (EEG) signals were acquired at a sampling rate of 128 Hz using BIS-VISTA with standard bispectral index (BIS) sensors. All data were stored on a computer for further analysis. The similarities and difference among spectral entropy, the BIS, and CAI were analyzed. Pearson correlation coefficient between the BIS and CAI was 0.825. The result of fitting the semiparametric regression models is the method CAI estimate (-0.00995; P = .0341). It is the estimated difference in the mean of the dependent variable between method BIS and CAI. The CAI algorithm, a simple and intuitive algorithm based on brain activity signal modeling, suggests an intrinsic relationship between the DoA and the EEG waveform. We suggest that the CAI algorithm might be used to quantify the DoA.

Objective: The dose of neuromuscular blocking drugs is commonly based on body weight, but using muscle mass might be more effective. This study investigated the relationship between the effect of neuromuscular blocking drugs and muscle mass measured using bioelectrical impedance analysis., Methods: Patients who were scheduled for elective surgery using a muscle relaxant were screened for inclusion in this study. Under intravenous anaesthesia, 12 mg or 9 mg of rocuronium was administered to males and females, respectively; and the maximal relaxation effect of T1 was measured using a TOF-Watch-SX® acceleromyograph., Results: This study enrolled 40 patients; 20 males and 20 females. For both sexes, the maximal relaxation effect of T1 did not correlate with the body weight-based dose of neuromuscular blocking drugs (males, r 2  = 0.12; females, r 2  = 0.26). Instead, it correlated with the dose based on bioelectrical impedance analysis-measured muscle mass when injected with the same dose of rocuronium (males, r 2  = 0.78, female, r 2  = 0.82)., Conclusions: This study showed that the muscle relaxation effect of rocuronium was correlated with muscle mass and did not correlate with body weight when using the same dose. Therefore, a muscle mass-based dose of neuromuscular blocking drugs is recommended.

Background: External applied pneumatic pressure is usually used for rapid transfusion of red blood cells (RBCs). However, increased shear stress can cause increased hemolysis and decreased RBC elongation indices. Therefore, the purpose of this study was to measure the degree of hemolysis and the alteration of RBC elongation indices under varying external pressure in fresh and aged blood., Methods: Venous blood samples were obtained from 20 healthy human volunteers. Each blood bag was divided into 2 subgroups (5 or 35 days of storage), and 5 levels of pressure were applied: 0, 150, 200, 250, and 300 mmHg. After infusion, a laboratory study was conducted. The percentages of irreversibly changed cells were evaluated using Bessis classification. RBC elongation indices were measured using a microfluidic ektacytometer., Results: There were no significant differences in the percentage of irreversibly changed RBCs between the pressures of 0 and 300 mmHg. Moreover, there were no significant differences in laboratory test results or elongation indices among all levels of pressure. Irreversibly changed RBCs and hemolysis were increased depending on the storage period., Conclusion: Irreversible changes in RBCs did not occur as a result of external pressure. The hemolysis and elongation indices of fresh RBCs were not influenced by external pneumatic pressure up to 300 mmHg. Only the storage period affected the irreversible changes in RBCs and hemolysis. Therefore, the application of external pressure to RBCs in variously aged blood is likely to be a safe procedure.

Objective: Adenotonsillectomy is a short surgical procedure under general anaesthesia in children. An ideal muscle relaxant for adenotonsillectomy would create an intense neuromuscular block while having a quick recovery time without postoperative morbidity. We compared the effect of different doses of rocuronium for the tracheal intubation in children under 5% sevoflurane and fentanyl., Materials and Methods: 75 children (aged 3-10 years, ASA I) scheduled for adenotonsillectomy were enrolled. Anaesthesia was induced with propofol 2.5 mg/kg, followed by fentanyl 2 μg/kg. After mask ventilation with 5 vol% sevoflurane in 100% oxygen for 2 min, 2 ml of study drug was administered intravenously, i.e., either normal saline (S Group) or one of two doses (0.15 or 0.3 mg/kg) of rocuronium. We assessed conditions during tracheal intubation and also recorded the surgical condition, the time from discontinuation of sevoflurane to extubation and PAED scale, pain scores in PACU., Results: Rocuronium groups (96% and 100%, respectively; P < 0.01) showed statistically superior clinically acceptable intubating conditions than the saline group (72%). The 0.3 mg/kg rocuronium (80%) treatment clearly resulted in excellent intubating conditions compared with the 0.15 mg/kg group (44%; p = 0.028). There was no significant difference in the time to extubation and surgical condition, and in the postoperative measures of emergence delirium, pain, and recovery time among the three groups., Conclusion: A dose of 0.3 mg/kg rocuronium may provide optimal intubating conditions without delayed recovery in 5% sevoflurane anaesthesia with fentanyl in children undergoing adenotonsillectomy., Clinical Trials Registry Number: NCT02467595., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background and Objective: Prediction of postoperative excessive blood loss is useful for management of Intensive Care Unit after cardiac surgery. The aim of present study was to examine the effectiveness of International Society on Thrombosis and Hemostasis scoring system in patients with cardiac surgery., Method: After obtaining approval from the institutional review board, the medical records of patients undergoing elective cardiac surgery using Cardio-Pulmonary Bypass between March 2010 and February 2014 were retrospectively reviewed. International Society on Thrombosis and Hemostasis score was calculated in intensive care unit and patients were divided with overt disseminated intravascular coagulation group and non-overt disseminated intravascular coagulation group. To evaluate correlation with estimated blood loss, student t-test and correlation analyses were used., Results: Among 384 patients with cardiac surgery, 70 patients with overt disseminated intravascular coagulation group (n=20) or non-overt disseminated intravascular coagulation group (n=50) were enrolled. Mean disseminated intravascular coagulation scores at intensive care unit admission was 5.35±0.59 (overt disseminated intravascular coagulation group) and 2.66±1.29 (non-overt disseminated intravascular coagulation group) and overt disseminated intravascular coagulation was induced in 29% (20/70). Overt disseminated intravascular coagulation group had much more EBL for 24h (p=0.006) and maintained longer time of intubation time (p=0.005)., Conclusion: In spite of limitation of retrospective design, management using International Society on Thrombosis and Hemostasis score in patients after cardiac surgery seems to be helpful for prediction of the post- cardio-pulmonary bypass excessive blood loss and prolonged tracheal intubation duration., (Copyright © 2017 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.)

Objectives: Organ transplant in humans is an established therapy for a variety of end-stage organ diseases. However, due to organ shortages and lack of donors, the need for xenotransplant has gradually increased. Xenotransplantation has great potential to solve many of the problems facing organ transplantation. Pigs are being developed as xenogeneic organ donors for use in humans. In this study, we propose a novel and simple method for tracheal intubation in a swine model using neuromuscular blocking agents and laryngeal mask airway., Materials and Methods: Eight Yorkshire pigs were used for the 2 separate experiments, which were conducted 1 week apart. In the first experiment, an anesthesiologist with no previous comparable experience performed endotracheal intubation of pigs. One week later, using the same pig, a second experiment was performed by an experienced anesthesiologist. Anesthesia was induced with intramuscular injection of a mixture of 1 mg/kg xylazine (Rompun, Bayer Korea Ltd., Seoul, Korea) and 7 mg/kg Zoletil (a mixture of tiletamine hydrochloride and zolazepam hydro-chloride, Virbac Laboratory, Carros, France). The laryngeal mask was then placed, and 0.15 mg/kg vecuronium bromide was injected intravenously. Tracheal intubation was attempted after mask removal. The duration and number of intubation attempts were recorded, and the degree of intubation difficulty was scored., Results: In all cases, the laryngeal mask was easily inserted, and endotracheal intubation was successfully completed. Oxygen saturation did not fall below 95%, and there were no hypoxemia episodes. Degree of intubation difficulty and duration were not significantly different between the 2 anesthesiologists., Conclusions: Tracheal intubation in our swine model was successfully performed using neuromuscular blocking agents and laryngeal masks without resulting in hypoxemia, with even anesthesiologists who are unfamiliar with endotracheal intubation of pigs easily able to do so using our protocol. Therefore, our protocol will enable all investigators to perform successful tracheal intubation in swine models.

Malignant hyperthermia (MH) may lead to metabolic crisis of skeletal muscle in susceptible individuals following exposure to triggering agents such as volatile anesthetics or depolarizing muscle relaxants. MH is a rare and a potentially lethal disease, which can lead to cardiac arrest. We report a case of severe MH, in which the rapidly evolving signs of hypermetabolism eventually resulted in cardiac arrest. Despite conventional treatments following cardiopulmonary resuscitation, the patient's vital signs did not improve. Therefore, we applied extracorporeal membrane oxygenation for providing hemodynamic support.

Background: For patients undergoing general anesthesia, adequate warming and humidification of the inspired gases is very important. The aim of this study was to evaluate the differences in the heat and moisture content of the inspired gases with low-flow anesthesia using 4 different anesthesia machines., Methods: The patients were divided into 11 groups according to the anesthesia machine used (Ohmeda, Excel; Avance; Dräger, Cato; and Primus) and the fresh gas flow (FGF) rate (0.5, 1, and 4 L/min). The temperature and absolute humidity of the inspired gas in the inspiratory limbs were measured at 5, 10, 15, 30, 45, 60, 75, 90, 105, and 120 minutes in 9 patients scheduled for total thyroidectomy or cervical spine operation in each group., Results: The anesthesia machines of Excel, Avance, Cato, and Primus did not show statistically significant changes in the inspired gas temperatures over time within each group with various FGFs. They, however, showed statistically significant changes in the absolute humidity of the inspired gas over time within each group with low FGF anesthesia (P < .05). The anesthesia machines of Cato and Primus showed statistically significant changes in the absolute humidity of the inspired gas over time within each group with an FGF of 4 L/min (P < .05). However, even with low-flow anesthesia, the temperatures and absolute humidities of the inspired gas for all anesthesia machines were lower than the recommended values., Conclusion: There were statistical differences in the provision of humidity among different anesthesia workstations. The Cato and Primus workstations were superior to Excel and Avance. However, even these were unsatisfactory in humans. Therefore, additional devices that provide inspired gases with adequate heat and humidity are needed for those undergoing general anesthetic procedures.

Objective The efficacy of chlorhexidine- and silver sulfadiazine-coated central venous catheters (CSS-CVC) against catheter-related infection remains controversial. We hypothesized that the loss of silver nanoparticles may reduce the antibacterial efficacy of CSS-CVCs and that this loss could be due to the frictional force between the surface of the CVC and the bloodstream. The objective of this study was to investigate whether the antimicrobial effect of CSS-CVCs decreases with increasing exposure time in a bloodstream model and quantitatively assay the antimicrobial effect of CSS-CVCs compared with polyurethane and antiseptic-impregnated CVCs. Methods Each CVC was subjected to 120 hours of saline flow and analyzed at intervals over 24 hours. The analyses included energy-dispersive X-ray spectroscopy, scanning electron microscopy, and optical density after a Staphylococcus aureus incubation test. Results The weight percentage of silver in the CSS-CVCs significantly decreased to 56.18% (44.10% ± 3.32%) with 48-hour catheterization and to 18.88% (14.82% ± 1.33%) with 120-hour catheterization compared with the initial weight percentage (78.50% ± 6.32%). In the S. aureus incubation test, the antibacterial function of CSS-CVCs was lost after 48 hours [3 (N/D) of OD]. Similar results were observed in a pilot clinical study using 18 CSS-CVCs. Conclusions We found that the efficacy of CSS-CVCs decreased over time and that the antibacterial function was lost after 48 hours of simulated wear-out. Therefore, antibiotic-impregnated CVCs may be a better option when longer (>48 hours) indwelling is needed.

Objectives/hypothesis: Laser microlaryngeal surgery (LMS) is a short operation requiring brief and intense paralysis. Adequate muscle relaxation and rapid recovery of neuromuscular function are essential for improving surgical conditions and reducing the incidence of complications during LMS. However, the ideal muscle relaxant with a rapid onset and short duration of action is not yet available. Rocuronium has rapid onset at higher doses, but with a prolonged duration of action. Sugammadex is a selective relaxant-binding agent that allows for rapid reversal of rocuronium-induced neuromuscular blockade. This study aimed to compare the surgical conditions and anesthesia time between two combinations of neuromuscular blocker and reversal agent, rocuronium-sugammadex (R-S) and succinylcholine-cisatracurium-pyridostigmine (S-C-P), and propose an optimal anesthetic regimen for improving the surgical conditions in LMS patients., Study Design: Prospective, randomized, double-blinded clinical study., Methods: Patients in the R-S group received 1 mg/kg rocuronium bromide, whereas those in the S-C-P group received 1 mg/kg succinylcholine. After endotracheal intubation, 0.08 mg/kg cisatracurium was injected in S-C-P patients. After the procedure, R-S patients received 2 mg/kg sugammedex, whereas S-C-P patients received 0.2 mg/kg pyridostigmine plus 10 μg/kg atropine., Results: In the R-S group, surgical condition scores were significantly higher and anesthesia time was significantly shorter. The use of additive neuromuscular blocking agents was significantly higher in the S-C-P group., Conclusions: Muscle relaxation with rocuronium and reversal with sugammadex resulted in better surgical conditions and a shorter anesthesia time in patients undergoing LMS when compared to the S-C-P regimen., Level of Evidence: 1b Laryngoscope, 127:1135-1139, 2017., (© 2016 The American Laryngological, Rhinological and Otological Society, Inc.)

This study aims to develop a window chamber system in the skin of rats and to monitor the primo vascular system (PVS) inside the lymphatic vessels along the superficial epigastric vessels. The PVS in lymphatic vessels has been observed through many experiments under in vivo conditions, but monitoring the in vivo PVS in situ inside lymphatic vessels for a long time is difficult. To overcome the obstacles, we adapted the window chamber system for monitoring the PVS and Alcian blue (AB) staining dye solution for the contrast agent. The lymphatic vessels in the skin on the lateral side of the body, connecting the inguinal lymph nodes to the axillary lymph nodes, were the targets for setting the window system. After AB had been injected into the inguinal lymph nodes with a glass capillary, the morphological changes of the stained PVS were monitored through the window system for up to twenty hours, and the changes in the AB intensity in the PVS were quantified by using image processing. The results and histological images are presented in this study.

Objective: To evaluate whether polymorphisms in the gamma-aminobutyric acid A receptor α1 subunit (GABRA1) gene influence sleep induction time, bispectral index score (BIS) during sleep induction and the total dose of midazolam required to reach a Ramsay Sedation Assessment Scale (RSAS) score of 4., Methods: Patients scheduled for elective orthopaedic surgery were enrolled. All patients received initial doses of 0.02 mg/kg intravenous midazolam. If the RSAS score did not reach 4, an additional 1-mg dose of midazolam was administered. Results were compared among groups of patients with five single-nucleotide polymorphisms (SNPs) in GABRA1: rs4263535, rs980791, rs6556562, rs998754 and rs2279020., Results: A total of 104 patients were evaluated. Polymorphism rs4263535 was associated with the lowest BIS during sedation induction. Multinomial logistic regression analysis demonstrated that polymorphism rs4263535 was significantly associated with the total dose of midazolam required for sedation induction., Conclusions: Polymorphism rs4263535 in GABRA1 intron 4 was associated with deeper sedation by intravenous midazolam. Patients with the A/A rs4263535 genotype required a smaller dose of midazolam., (© The Author(s) 2015.)

With chromium-hematoxylin staining, we found evidence for the existence of novel age-dependent network structures in the dura mater of rat brains. Under stereomicroscopy, we noticed that chromium-hematoxylin-stained threadlike structures, which were barely observable in 1-week-old rats, were networked in specific areas of the brain, for example, the lateral lobes and the cerebella, in 4-week-old rats. In 7-week-old rats, those structures were found to have become larger and better networked. With phase contrast microscopy, we found that in 1-week-old rats, chromium-hematoxylin-stained granules were scattered in the same areas of the brain in which the network structures would later be observed in the 4- and 7-week-old rats. Such age-dependent network structures were examined by using optical and transmission electron microscopy, and the following results were obtained. The scattered granules fused into networks with increasing age. Cross-sections of the age-dependent network structures demonstrated heavily-stained basophilic substructures. Transmission electron microscopy revealed the basophilic substructures to be clusters with high electron densities consisting of nanosized particles. We report these data as evidence for the existence of age-dependent network structures in the dura mater, we discuss their putative functions of age-dependent network structures beyond the general concept of the dura mater as a supporting matrix.

This work reports micromachined tethered silicon oscillators (MTSOs) for endoscopic Lissajous fiber scanners. An MTSO comprises an offset silicon spring for stiffness modulation of a scanning fiber and additional mass for modulation of resonant scanning frequency in one body. MTSOs were assembled with a resonant fiber scanner and enhanced scanning reliability of the scanner by eliminating mechanical cross coupling. The fiber scanner with MTSOs was fully packaged as an endomicroscopic catheter and coupled with a conventional laparoscope and spectral domain OCT system. The endomicroscope was maneuvered with the integrated laparoscope and in vivo swine tissue OCT imaging was successfully demonstrated during open surgery. This new component serves as an important element inside an endoscopic Lissajous fiber scanner for early cancer detection or on-demand minimum lesional margin decision during noninvasive endoscopic biopsy.

We report a case of increased values of entropy parameters Response Entropy (RE) and State Entropy (SE) during intravenous general anesthesia in a sleepwalking patient. An ASA class II, 64-year-old woman with stress incontinence underwent mid-urethral sling surgery. Prior to surgery, the patient had been administered paroxetine, valproic acid and clonazepam for the treatment of sleepwalking disorder. After 10 min of target-controlled infusion of propofol and remifentanil, entropy values increased up to 94 (RE) and 88 (SE) for 10 min. The target effect-site concentrations of anesthetics increased from 4 to 7 µg/ml propofol and 4 ng/ml remifentanil, at which point values fell back to adequate anesthesia levels. Episodes of recall or of explicit memories did not occur during the anesthesia. In conclusion, sleepwalking patients with long-term use medications may need increment of anesthetic dose caused by the anesthetic drug metabolism activation or impairment or immaturity of inhibitory circuits in brain.

Objective: Propofol and volatile anesthesia have been associated with metabolic acidosis induced by increased lactate. This study was designed to evaluate changes in pH, base excess (BE), and lactate in response to different anesthetic agents and to characterize propofol infusion-associated lactic acidosis., Methods: The medical records of patients undergoing neurosurgical anesthesia between January 2005 and September 2012 were examined. Patients were divided into 2 groups : those who received propofol (total intravenous anesthesia, TIVA) and those who received sevoflurane (balanced inhalation anesthesia, BIA) anesthesia. Propensity analysis was performed (1 : 1 match, n=47), and the characteristics of the patients who developed severe acidosis were recorded., Results: In the matched TIVA and BIA groups, the incidence of metabolic acidosis (11% vs. 13%, p=1) and base excess (p>0.05) were similar. All patients in the TIVA group who developed severe acidosis did so within 4 hours of the initiation of propofol infusion, and these patients improved when propofol was discontinued., Conclusions: The incidence of metabolic acidosis was similar during neurosurgical anesthesia with propofol or sevoflurane. In addition, severe acidosis associated with propofol infusion appears to be reversible when propofol is discontinued.

Background: Midazolam has been widely studied for preventing emergence agitation. The authors previously reported that in children with sevoflurane anesthesia, intravenous administration of midazolam (0.05 mg/kg) before the end of surgery reduced the incidence of emergence agitation but prolonged the emergence time. This study was designed to test the hypothesis that a lower midazolam dose could suppress emergence agitation with minimal disturbance of the emergence time in children with sevoflurane anesthesia., Methods: In this randomized, double-blind, placebo-controlled trial, 90 children (1 to 13 yr of age) having strabismus surgery were randomized to 1:1:1 to receive 0.03 mg/kg of midazolam, 0.05 mg/kg of midazolam, or saline just before the end of surgery. The primary outcome, the incidence of emergence agitation, was evaluated by using the pediatric anesthesia emergence delirium scale and the four-point agitation scale. The secondary outcome was time to emergence, defined as the time from sevoflurane discontinuation to the time to extubation., Results: The incidence of emergence agitation was lower in patients given 0.03 mg/kg of midazolam (5 of 30, 16.7%) and patients given 0.05 mg/kg of midazolam (5 of 30, 16.7%) compared with that in patients given saline (13/of 30, 43.3%; P = 0.036 each). The emergence time was longer in patients given 0.05 mg/kg of midazolam (17.1 ± 3.4 min, mean ± SD) compared with that in patients given 0.03 mg/kg of midazolam (14.1 ± 3.6 min; P = 0.0009) or saline (12.8 ± 4.1 min; P = 0.0003)., Conclusion: Intravenous administration of 0.03 mg/kg of midazolam just before the end of surgery reduces emergence agitation without delaying the emergence time in children having strabismus surgery with sevoflurane anesthesia.

Real-time quantification of the patient's consciousness level during anesthesia is an important issue to avoid intraoperative awareness and post-operative side effects. A depth-of-anesthesia (DoA) monitoring method called Bispectral Index (BIS) is generally used for this purpose. However, BIS is known to be inaccurate at the transitory state, and also shows a critical time delay in quantifying the patient's consciousness level. This paper introduces a novel method to reduce the response time in the quantification process. This thesis develops a new index called HDoA by analyzing EEG using Hidden Markov Model. The proposed approach is composed by two steps, training and testing. In the training step, two HMM, awakened and anesthetized model are learned based on each training set. In the testing step, by evaluating the probability of producing the testing EEG from two models respectively, the index HDoA is derived. Since the evaluation of DoA using HMM is training based method, it have better performance with more training process. Experiments show that HDoA has a high correlation with BIS at a steady state, and outperforms BIS in two ways: (1) shorter delay time in transition state, and (2) higher Fisher Score. The validity of HDoA has been tested by 8 real clinical data.

Background. The types of embryonic development probably provoke different paths of novel threadlike structure (NTS) development. The authors hypothesized that NTS may be easily observed on the surface of swine intestines by using trypan blue staining method and visualization under an optical microscope. Methods. General anesthesia was administered to 2 Yorkshire pigs. The abdominal walls of the pigs were carefully dissected along the medial alba. NTSs were identified on organ surfaces under a stereoscopic microscope after trypan blue staining. Isolated NTS specimens obtained from the large intestine were subjected to 4',6-diamidino-2-phenylindole (DAPI) staining and observed using the polarized light microscopy to confirm whether the obtained structure fits the definition of NTS. Results. We found elastic, semitransparent threadlike structures (forming a network structure) that had a milky-white color in situ and in vivo in swine large intestines. The samples showed distinct extinction of polarized light at every 90 degrees, and nucleus was shown to be rod shaped by DAPI staining, indicating that they meet the criteria of NTS. Conclusion. We used a swine model to demonstrate that NTS may be present on large animal organ surfaces. Our results may permit similar studies by using human specimens.

We for the first time reported evidence for the existence of a novel network, a PVS, abovethe epicardium of the rat heart. (1) We were consecutively able to visualize the PVs and the PNs above the epicardial spaces of five rats' hearts by using Cr-Hx spraying or injection. (2) Hematoxylin and eosin (H&E) and toluidine blue staining of the PVs and the PNs showed that they consisted of a basophilic matrix; specifically the PNs contained several mast cells, some of which were degranulating into pericardial space. Also, 4', 6-diamidino-2 phenylindole (DAPI) images of the PVs and the PNs showed that they contained various kinds of cells. (3) Transmission electron microscopic (TEM) longitudinal image of the PVs showed that the sinuses contained many granules with high-electron-density cores in parallel with putative endothelial cells. (4) TEM images of the PNs demonstrated that they consisted of lumen-containing cells surrounded by fibers and that they had mast cells that were degranulating toward the epicardium of the rat heart. The above data suggest that mast-cells-containing novel network exists above the epicardium of the rat heart.

In this paper, a cepstral analysis based approach to measuring the depth of anesthesia (DoA) is presented. Cepstral analysis is a signal processing technique widely used especially for speech recognition in order to extract speech information regardless of vocal cord characteristics. The resulting index for the DoA is called index based on cepstral analysis (ICep). The Fisher criterion is engaged to evaluate the performance of indices. All analyses are based on a single-channel electroencephalogram (EEG) of 10 human subjects. To validate the proposed technique, ICep is compared with bispectral index (BIS), which is the most commonly used method to estimate the level of consciousness via EEG during general anesthesia. The results show that ICep has high correlation with BIS, and is outstanding in terms of the Fisher criterion and offers faster tracking than BIS in the transition from consciousness to unconsciousness.

Background. Primo vascular system is a new anatomical structure whose research results have reported the possibility of a new circulatory system similar to the blood vascular system and cells. Electrophysiology, which measures and analyzes bioelectrical signals tissues and cells, is an important research area for investigating the function of tissues and cells. The bioelectrical study of the primo vascular system has been reported by using modern techniques since the early 1960s by Bonghan Kim. This paper reviews the research result of the electrophysiological study of the primo vascular system for the discussion of the circulatory function. We hope it would help to study the electrophysiology of the primo vascular system for researchers. This paper will use the following exchangeable expressions: Kyungrak system = Bonghan system = Bonghan circulatory system = primo vascular system = primo system; Bonghan corpuscle = primo node; Bonghan duct = primo vessel. We think that objective descriptions of reviewed papers are more important than unified expressions when citing the papers. That said, this paper will unify the expressions of the primo vascular system.

This paper suggests a theoretical framework for the primo vascular system (PVS), a hypothetical circulatory system, in which extracellular DNA microvesicles interact to form and break down cell structures. Since Bonghan Kim reported the existence of Bonghan ducts and the SNU research team reinvestigated and named it the PVS, there has been series of studies trying to examine its structure and functions. In this paper, we hypothesize that the PVS is the network system in which extracellular DNA microvesicles circulate and interact at the subcellular level, forming and breaking down cell structures. This idea integrates A. Béchamp's idea of microzymas and Bonghan Kim's idea of sanals. A proof of this idea may complement modern medical theory, perhaps providing an essential clue for an alternative solution dealing with modern healthcare problem.

Background. The lumen of novel threadlike structures (NTSs) is enclosed by a single layer of endothelial cells surrounded by extracellular matrix (ECM). We hypothesized that collagen may be a component of the ECM associated with lymphatic NTSs. Methods. Six female New Zealand white rabbits were anesthetized, and the NTS structures within lymphatic vessels were identified by contrast-enhanced stereomicroscopy or alcian blue staining. Isolated NTS specimens were stained with acridine orange, YOYO-1, and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). The structural and molecular composition of the ECM was investigated using transmission electron microscopy (TEM), electrospray ionization-mass spectrometry, and proteomic analysis. Results. The lymph vessel wall was stained red by DiI, and rod-shaped nuclei were stained green by YOYO-1. The area surrounding the NTS was also stained red and contained green rod-shaped nuclei. TEM images showed that the NTS consisted of many ECM fibers and the ECM fibers appeared to be ~100 nm in diameter and had narrowly spaced striated bands. Proteomic analysis of the lymphatic NTS-associated ECM identified 4 proteins: keratin 10, cytokeratin 3, cytokeratin 12, and soluble adenylyl cyclase. Conclusion. The TEM study suggested that the lymphatic NTS-associated ECM did not contain collagen. This was confirmed by proteomic analysis, which showed that keratin was the major component of the ECM.