Calciphylaxis in uraemic and nonuraemic settings: clinical risk factors and histopathological findings.

BACKGROUND: Calciphylaxis is a life-threatening cutaneous ulcerative/necrotic disease characterized by vascular calcification/occlusion. It occurs most commonly in end-stage kidney disease (ESKD), known as uraemic calciphylaxis (UC) but can also occur in patients with chronic kidney disease (CKD) and normal kidney function (nonuraemic calciphylaxis; NUC). There are few large series of NUC in the literature. AIM: To compare the clinicopathological features of UC and NUC. METHODS: We retrospectively compared the clinicopathological features of 35 patients with NUC during the period 2010-2020 with those of 53 patients with UC (control group). Cases were classified as NUC in the absence of all of the following: ESKD, significant CKD (defined as serum creatinine > 3 mg/dL or creatinine clearance < 15 mL/min) and acute kidney injury requiring kidney replacement therapy or kidney transplantation. RESULTS: NUC represented 40% of the total cases, and there was a higher number of women (P < 0.01) and a higher median body mass index (P = 0.06) compared with the control UC group. Elevated parathyroid hormone was present in 44% of patients with NUC. Most of the tested patients were positive for lupus anticoagulants (56%). NUC biopsies showed a higher rate of extravascular calcium deposits (73% vs. 47%, P = 0.03). Dermal reactive vascular proliferation was the most common dermal change (32%). CONCLUSIONS: NUC is more common than previously reported and shows a higher predilection for obese postmenopausal women. Undiagnosed hyperparathyroidism shows a possible association with NUC. Lupus anticoagulants were positive in most patients. NUC biopsies are more likely than UC biopsies to display extravascular calcium deposition.

Relationship Between Intraoperative Bispectral Index and Consciousness Recovery in Patients With Hepatic Encephalopathy Undergoing Liver Transplant: A Retrospective Analysis.

BACKGROUND: Although liver transplant (LT) improves liver function and restores symptoms of hepatic encephalopathy (HE), there is no index to predict the recovery of consciousness in patients with HE during LT. In this study, we evaluated the relationship between intraoperative bispectral index (BIS) values and the recovery of consciousness in patients with HE who were undergoing LT. METHODS: Patients with HE who underwent LT from June 2011 to December 2017 at our institution were enrolled. A total of 64 patients were enrolled, and, using the West Haven Criteria, they were divided into 2 groups: nonsevere HE group (n = 26), grades 1 to 2 HE; and severe HE group (n = 38), grades 3 to 4 HE. Grade of HE, intraoperative BIS, minimum alveolar concentration values, postoperative Glasgow Coma Scale (GCS) score, and the time to recover consciousness were compared. RESULTS: The severe HE group showed lower BIS after anesthetic induction compared with the nonsevere HE group (P = .005). In the severe HE group, intraoperative BIS gradient (the difference between values measured 4 hours after reperfusion and immediately after anesthesia induction) was significantly larger than in the nonsevere HE group (P = .001). Time to recovery of consciousness was prolonged in the severe HE group (P = .002). Model for End-Stage Liver Disease (MELD) score and the GCS score at 24 hours after LT were associated with delayed recovery of consciousness (MELD score: hazard ratio, 1.103; 95% CI, 1.002-1.214; P = .046; GCS score at 24 hours after LT: hazard ratio, 0.688; 95% CI, 0.566-0.835; P < .001). CONCLUSIONS: Our study indicated that BIS values immediately after anesthesia induction were significantly lower in patients with severe HE. However, it did not show a significant relationship with the time to recovery of consciousness after LT. Multivariate analysis demonstrated that MELD score and GCS score at 24 hours after LT were associated with the time to recovery of consciousness.

Weaning of Veno-venous Bypass in Liver Transplantation: A Single Center Experience.

BACKGROUND: Veno-venous bypass (VVB) has been used in liver transplantation (LT) to minimize hemodynamic instability during caval anastomosis of anhepatic phase. With the introduction of the piggyback (PB) technique, which is a caval-sparing technique, the use of VVB progressively decreased over the world. The aim of this study was to introduce our experience using VVB with the focus on its weaning process. METHODS: A total of 300 consecutive LT cases from May 1996 to November 2003 were examined. Except for pediatric LT, 242 LT cases were investigated to evaluate the trends in VVB use, surgical technique, the amount of transfusion requirements, and durations of operation and anhepatic phase. RESULTS: For the early 100 LT cases, VVB was used in 97.5% of recipients, especially in all the recipients of deceased donor LT (DDLT). Then, the frequency of VVB use was decreased, and VVB was not used after the 268th recipient. In DDLT, the PB technique was first introduced in the 58th recipient and became a routine procedure of the DDLT since the 191th recipient. Living donor LT was increased, and the amount of transfusion requirement, duration of operation, and duration of anhepatic phase was reduced over time. CONCLUSIONS: The increasing experience and sophisticated surgical and anesthetic techniques were important factors responsible for the weaning of VVB. The advancement of the PB technique used in living donor LT might be a main factor of its weaning.

Association of Platelet Count and Platelet Transfusion With Serotonin Level During Living Donor Liver Transplantation: Possible Connection to Graft Regeneration.

BACKGROUND: We recently showed that platelet counts and the amount of platelet transfusion during liver transplantation are positively associated with early graft regeneration. It was hypothesized that platelet-derived serotonin mediates liver regeneration. OBJECTIVES: This study aimed to evaluate the association between intraoperative platelet count, platelet transfusion, and serum serotonin level. METHODS: Thirty-two recipients undergoing living-donor liver transplantation were enrolled into this prospective observational study. Serum platelet counts and serotonin levels were measured at the following times: anesthetic induction, start of the anhepatic phase, before graft reperfusion, 5 minutes/1 hour/3 hours/5 hours after graft reperfusion, and before/after platelet transfusion. Serotonin was measured by using a liquid chromatography tandem mass spectrometry. RESULTS: Serotonin level at the anesthetic induction was 24.5 µg/mL (interquartile range, 14.6 to 38.1 µg/mL). During surgery, serial changes in platelet counts and serotonin levels showed a similar trend: they decreased during the anhepatic phase, increased during the first hour after graft reperfusion, and thereafter gradually decreased. Serotonin level was positively correlated with platelet counts (correlation coefficient = 0.620, P < .001). Allogeneic platelet transfusion significantly increased platelet count from 22 (19-31) × 109/L to 53 (50-81) × 109/L (P = .008) and it also increased serum serotonin from 11.04 (6.41-15.34) µg/mL to 34.26 (25.86-41.94) µg/mL (P = .008). CONCLUSIONS: Our findings indicate that allogeneic platelets could act as effector cells deriving serotonins. Also, our findings support the hypothesis that the association between platelets and post-transplantation graft regeneration is mediated by serotonin. Further studies are warranted regarding the respective role of serotonin and other platelet-derived molecules mediating liver regeneration.

Cutaneous Adnexal Cylindroma of Breast: Epithelial Immunoreactivities for GATA-3, Mammaglobin, and E-Cadherin Do Not Equate to a Mammary Ductal Neoplasm.

Cylindromas are benign epithelial neoplasms derived from cutaneous eccrine adnexal structures. These tumors are most commonly encountered on the head, neck, and scalp of older women. In rare instances, solitary cylindromas may arise at other body sites. In the current case, a cylindroma of the skin of the breast was diagnosed by complete excision. Immunohistochemical studies confirmed the tumor cells to be immunoreactive with cytokeratin AE1/3, cytokeratin 5/6, cytokeratin 7, p63, and SOX10. The neoplastic cells were also noted to be immunoreactive with markers typically expected to be positive in ductal epithelium of the breast including GATA3, mammaglobin, and E-cadherin. The case emphasizes the importance of correlating clinical setting, imaging studies, patient history, and careful microscopic evaluation in arriving at an accurate diagnosis. This case also illustrates the point that not all "breast" tumors that are confirmed to be positive for GATA3, mammaglobin, and E-cadherin are derived from mammary ducts.

Effect of topical loteprednol etabonate with lid hygiene on tear cytokines and meibomian gland dysfunction in prosthetic eye wearers.

PurposeTo assess tear cytokine levels and clinical outcomes in meibomian gland dysfunction (MGD) in the blind eye of patients wearing an ocular prosthesis after 2 months of treatment with topical loteprednol etabonate and eyelid scrubs with warm compresses.Patients and methodsThis study included patients with MGD wearing a unilateral ocular prosthesis for more than 1 year. All patients topically received 0.5% loteprednol etabonate and were instructed to scrub their eyelids with warm compresses on the prosthetic eye for 2 months. We evaluated tear cytokine levels using Multiplex Bead Immunoassays, performed biomicroscopic examination of the lid margins and meibomian gland, conducted meibography imaging, and assessed MGD-related ocular symptoms using a questionnaire for the prosthetic eye before and 2 months after treatment.ResultsThirty consecutive patients were included. There were significant reductions in the levels of interleukin (IL)-6, interferon-γ, monocyte chemotactic protein-1, IL-8, tumor necrosis factor-α, and IL-1ß (P<0.001 for each cytokine). Moreover, there were improvements in ocular symptoms (P=0.001), lid margin abnormalities (P<0.001), meibomian gland expressibility (P<0.001) and meibography findings (P=0.037).ConclusionTopical loteprednol etabonate in conjunction with eyelid scrubs and warm compresses were effective in treating MGD in prosthetic eye wearers. Furthermore, tear cytokine measurements may serve as an additional approach for evaluating the efficacy of anti-inflammatory treatment for MGD in prosthetic eye wearers.

Ischemic Preconditioning Produces Comparable Protection Against Hepatic Ischemia/Reperfusion Injury Under Isoflurane and Sevoflurane Anesthesia in Rats.

BACKGROUND: Various volatile anesthetics and ischemic preconditioning (IP) have been demonstrated to exert protective effect against ischemia/reperfusion (I/R) injury in liver. We aimed to determine whether application of IP under isoflurane and sevoflurane anesthesia would confer protection against hepatic I/R injury in rats. METHODS: Thirty-eight rats weighing 270 to 300 grams were randomly divided into 2 groups: isoflurane (1.5%) and sevoflurane (2.5%) anesthesia groups. Each group was subdivided into sham (n = 3), non-IP (n = 8; 45 minutes of hepatic ischemia), and IP (n = 8, IP consisting of 10-minute ischemia plus 15-minute reperfusion before prolonged ischemia) groups. The degree of hepatic injury and expressions of B-cell lymphoma 2 (Bcl-2) and caspase 3 were compared at 2 hours after reperfusion. RESULTS: Hepatic ischemia induced significant degree of I/R injuries in both isoflurane and sevoflurane non-IP groups. In both anesthetic groups, introduction of IP dramatically attenuated I/R injuries as marked by significantly lower aspartate aminotransferase and aminotransferase levels and better histologic grades compared with corresponding non-IP groups. There were 2.3- and 1.7-fold increases in Bcl-2 mRNA levels in isoflurane and sevoflurane IP groups, respectively, compared with corresponding non-IP groups (both P < .05). Caspase 3 level was significantly high in the isoflurane non-IP group compared with the sham group; however, there were no differences among the sevoflurane groups. CONCLUSIONS: The degree of hepatic I/R injury was significantly high in both isoflurane and sevoflurane groups in rats. However, application of IP significantly protected against I/R injury in both volatile anesthetic groups to similar degrees, and upregulation of Bcl-2 might be an important mechanism.

Effect of Prereperfusion Ephedrine on Postreperfusion Syndrome and Graft Function in Living Donor Liver Transplantation.

A characteristic pattern of hemodynamic changes that may occur after reperfusion during liver transplantation (LT) is known as postreperfusion syndrome (PRS). We investigated the effect of prophylactic ephedrine administration on PRS and postoperative laboratory results in living donor LT. The medical records of adult recipients who underwent living donor LT were reviewed. A total of 308 recipients were divided into the prophylaxis group and the nonprophylaxis group. Graft factors, preoperative and intraoperative recipient factors, and postoperative laboratory results were compared between the 2 groups. Graft factors and preoperative and intraoperative recipient factors did not differ between the 2 groups, except the prevalence of diabetes mellitus and etiology of liver disease. After reperfusion, PRS occurred more frequently (43.2% vs 25.0%; P = .006), and mean arterial pressure was more reduced compared with prereperfusion values (33.7 ± 15.8% vs 22.3 ± 23.5%; P < .001) in the nonprophylaxis group than the prophylaxis group. Postoperative laboratory results did not differ between the 2 groups. In conclusion, prereperfusion administration of ephedrine reduced the incidence and severity of PRS. Further prospective studies on the relationship between prophylactic medication and posttransplantation outcomes are needed.

Use of Dexmedetomidine in Liver Transplant Recipients With Postoperative Agitated Delirium.

BACKGROUND AND OBJECTIVE: Agitated delirium has frequently occurred after liver transplantation in the intensive care unit (ICU) and sedative agents are used to treat patients. Recently, dexmedetomidine has been considered to be a promising agent for agitated delirium. METHODS: This study took place between January 2010 and October 2012 and 42 recipients were retrospectively enrolled. Sixteen recipients were enrolled in the dexmedetomidine group and 26 recipients were placed in the haloperidol group. To compare dexmedetomidine and haloperidol, the total ICU length of stay (ICU LOS), the ICU LOS after drug administration, and the supplemental doses of sedative agents used were assessed. The endpoint was discharge from the ICU. RESULTS: There were no significant drug-related complications in either group. Dexmedetomidine significantly decreased the ICU LOS and ICU LOS after the occurrence of delirium compared to haloperidol (13.7 days vs. 8.3 days, P = .039, 10.1 days vs. 3.1 days, P = .009). In the dexmedetomidine group, the dose of supplemental midazolam needed was lower than in the haloperidol group (1.5 mg vs. 6.85 mg, P < .001). CONCLUSION: Dexmedetomidine is a promising agent for the treatment of ICU-associated agitated delirium in liver transplantation recipients.

Evaluation of "flat-line" thromboelastography after reperfusion during liver transplantation.

BACKGROUND: "Flat-line" (no clot formation) thromboelastography (TEG) is frequently observed after graft reperfusion during liver transplantation (LT). We aimed to evaluate the incidence and causes of flat-line TEG after graft reperfusion during LT. METHODS: With institutional review board approval, data of 208 consecutive recipients who underwent LT from May 2010 to May 2012 were retrospectively reviewed. We performed 3 different types of TEG measurements at 5 minutes after graft reperfusion: native TEG (nTEG), tranexamic acid-added TEG (tTEG), and protamine-added TEG (pTEG). The flat-line TEG was defined as having no trace at all at 60 minutes of TEG. We examined the incidence and causes of flat-line nTEG. We also compared recipients with flat-line nTEG (F group) and clot-forming nTEG (C group). RESULTS: One hundred eighty-two recipients were included in the final analysis. The incidence of flat-line nTEG was 27% (49/182 cases). Among 49 recipients in the F group, 28 recipients showed clot formation in both tTEG and pTEG, 19 recipients in only tTEG, and 1 recipient in only pTEG; 1 recipient showed no clot formation in any TEGs. Graft from the deceased donor was more frequently observed in the F group than in the C group (P = .039). The F group showed decreased platelet count (P = .001), increased prothrombin time (P = .002), and decreased fibrinogen (P = .009) compared with the C group. CONCLUSIONS: No clot formation was relatively common after reperfusion during LT, and the main causes were hyperfibrinolysis and heparin effect. Liver graft from deceased donors was associated more frequently with no clot formation after reperfusion during LT.

Identification of novel mutations in the VPS33B gene involved in arthrogryposis, renal dysfunction, and cholestasis syndrome.

Arthrogryposis, renal dysfunction, and cholestasis (ARC) syndrome is an autosomal recessive disorder caused by mutations in the VPS33B and VIPAS39. Here, we report novel mutations identified in four patients with ARC syndrome. We analyzed the entire coding regions of the VPS33B and VIPAS39 genes by direct sequencing. To detect novel splice site mutations, mRNA transcripts were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and sequencing. All four patients had compound heterozygous variants in the VPS33B gene. One patient had a previously reported splice site variant with unknown significance, c.239+5G>A, and a novel nonsense mutation, c.621G>A. The other three patients had the c.403+2T>A mutation, and each of them carried one of the splice site variants, c.239+5G>A or c.499-11G>A. c.239+5G>A and c.499-11G>A created novel splice sites which resulted in abnormal transcripts. No significant VIPAS39 mutation was detected in all patients. In patients suspected with ARC syndrome, mutation analysis of the VPS33B gene should be employed as a primary diagnostic test before performing invasive testing procedures such as organ biopsies. Performing mRNA analysis can be useful in predicting the pathogenic phenotype when the mutation seems to affect a normal splicing mechanism.

Acute postoperative pain relief with immediate-release tapentadol: randomized, double-blind, placebo-controlled study conducted in South Korea.

OBJECTIVE: To broaden the ethnic groups in which tapentadol IR is evaluated for treating acute postoperative pain to include Asians. METHODS: In this phase 3, multicenter, double-blind, randomized study, 352 Korean adults with moderate-to-severe pain following hallux valgus surgery received tapentadol IR 50 or 75 mg or placebo orally every 4-6 hours for 72 hours. Patients requesting other (rescue) analgesics during this period were discontinued for lack of efficacy. The primary endpoint, sum of pain intensity difference (SPID) over 48 hours, was evaluated based on the difference between tapentadol IR and placebo in least squares (LS) mean change from baseline using analysis of covariance (ANCOVA). Secondary endpoints included the time to first rescue medication use and the distribution of responder rates. RESULTS: A treatment effect, favoring tapentadol IR, was observed for SPID48 (p < 0.001 for both doses vs. placebo, ANCOVA). The between-group difference (vs. placebo) in LS means of SPID48 was 76.4 (95% CI: 51.0, 101.7) for tapentadol IR 50 mg and 90.6 (95% CI: 65.1, 116.1) for tapentadol IR 75 mg. Time to first rescue medication use was delayed for tapentadol IR (p < 0.001 for both doses vs. placebo; log-rank test). The distribution of responders at 12, 24, 48, and 72 hours favored tapentadol IR (p ≤ 0.001 for both doses vs. placebo; Cochran-Mantel-Haenszel test). Dizziness, nausea, and vomiting were each reported in ≥ 10% tapentadol-treated patients and at an incidence ≥ 2-fold higher vs. placebo. The study findings may be limited by study drug dosing every 4 to 6 hours and frequent monitoring during treatment, neither of which mimic pain treatment in clinical practice. However, any potential bias based on this systematic monitoring of patients would be mitigated by the randomized, double-blind nature of the study, with all treatment groups similarly affected by such biases, if any. CONCLUSIONS: Tapentadol IR reduced acute pain intensity, significantly more than placebo, after orthopedic surgery in Korean patients. CLINICAL TRIAL REGISTRATION: NCT01516008.

The comparisons of hepatitis C virus RNA level between intraoperative blood salvage (cell saver) and systemic hepatitis C virus RNA kinetics during liver transplantation.

BACKGROUND: Cell Saver (CS; Haemonemic Corp, Braintree, Mass, United States) is frequently used to decrease transfusion requirements of homologous blood during liver transplantation (OLT). However, the use of CS in hepatitis C virus (HCV)-infected recipients is still debated owing to the potential elevation of HCV RNA level. In this study, we compared HCV RNA levels of CS blood with a series of blood samples obtained from HCV-infected OLT recipients. METHODS: Twelve HCV-infected patients with >50,000 copies/mL of HCV RNA were enrolled. HCV RNA was measured immediately after induction (I), at the end of anhepatic period (II), at the end of operation (III), and from the first returned blood in CS (CSb). HCV RNA level at each time period was compared. RESULTS: HCV RNA levels ranged from 77,931 to 9,072,000 copies/mL at I. When compared to I, HCV RNA levels were reduced to 11.1% ± 13.0% and 0.7% ± 1.0% at II and III, respectively. Also, the RNA level reduced to 3.0% ± 2.0% of I after CS processing. The HCV RNA level at I was significantly higher than the levels at II, III, and CSb (P = .012, each), and the level at II was significantly higher than the level at III (P = .012). The HCV RNA level at CSb showed no statistical difference with the levels at II, but it was significantly higher than the level at III (P = .042). CONCLUSIONS: The use of CS in HCV-infected OLT recipients seems to carry no additional risk with respect to intraoperative HCV RNA kinetics.

Risk factors for inadvertent hypothermia during adult living-donor liver transplantation.

BACKGROUND: Hypothermia (core temperature <35°C) causes multiple physiologic disturbances, including coagulopathy and cardiac dysfunction. Patients undergoing liver transplantation are at risk of inadvertent hypothermia and might be more vulnerable to its adverse effects. We sought to identify the factors contributing to hypothermia during living-donor liver transplantation (LDLT), which have not yet been studied in depth. METHODS: Medical records of 134 recipients who underwent adult-to-adult LDLT were reviewed. Core temperature at the following time points were taken: anesthetic induction, skin incision, start and end of the anhepatic phase, and hourly after hepatic reperfusion. RESULTS: Of 134 recipients, 29 (21.6%) developed hypothermia during surgery. Four independent risk factors for hypothermia were identified: small body weight-to-body surface area ratio, acute hepatic failure, high Model for End-Stage Liver Disease (MELD) score, and low graft-to-recipient weight ratio. The amount of core temperature drop was positively correlated with the number of involved risk factors. Each risk factor had a respective contribution according to the operative phases: body weight-to-body surface area ratio and the MELD score for the preanhepatic phase, acute deterioration of hepatic failure for the anhepatic phase, and graft-to-recipient weight ratio was for the postreperfusion phase. CONCLUSIONS: Hypothermia was independently associated with the recipient's morphometric characteristics, emergency of end-stage liver disease, MELD score, and graft volume. These factors showed a cumulative effect, and the role of each factor was different according to the operative phase. These results should aid in the development of an optimal thermal strategy during LDLT.

Analysis of predictors for lactate elimination after reperfusion in recipients of living-donor liver transplantation.

BACKGROUND: Graft-recipient weight ratio (GRWR) is the only documented predictor that influences the lactate elimination after reperfusion in living-donor liver transplantation (LDLT). This study was performed to investigate the predictors of lactate elimination after reperfusion in recipients of adult LDLT. METHODS: The medical records of 159 patients who underwent LDLT were analyzed. Lactate level (mmol/L) was measured from just before the initiation of surgery (P0) and 5, 60, and 120 minutes after reperfusion of graft (R0, R1, and R2, respectively). The change of lactate level after reperfusion was defined as difference between lactate level measured at R0 and R2. Patients were divided into accumulation and elimination groups. Donor and recipient factors were compared between the 2 groups. RESULTS: Lactate accumulation occurred in 80 of 159 recipients (50.3%), and elimination occurred in 79 (49.7%). GRWR and Model for End-Stage Liver Disease (MELD) score were higher in the elimination group. Lactate at R0 was lower in the elimination group. CONCLUSIONS: Higher GRWR and MELD score and lower lactate level immediate after reperfusion of graft were predictors of lactate elimination after reperfusion during adult LDLT.

Factors associated with consciousness recovery time after liver transplantation in recipients with hepatic encephalopathy.

BACKGROUND: Hepatic encephalopathy (HE) occurs as a result of liver failure and is often considered to be a clinical indication for liver transplantation (LT). An assessment of post-transplantation consciousness level in recipients with HE is crucial, because recovery of consciousness implies reestablishment of transplant liver function and lack of perioperative brain damage. The purpose of this study is to evaluate factors associated with consciousness recovery time after LT in recipients with HE. METHODS: Out of 633 adult recipients who underwent LT, recipients who exhibited HE at the time of LT were analyzed retrospectively. The time between graft reperfusion and postoperative consciousness recovery was determined, and recipients were divided into 2 groups: group E with recovery of consciousness early (≤48 hours), and group L with recovery of consciousness late (>48 hours). Analyzed variables included recipient sex, age, graft type, Model for End-Stage Liver Disease score, HE history/duration/type/grade, and preoperative laboratory values, including blood ammonia concentration. RESULTS: HE was present at the time of LT in 69 (10.9%) of 633 recipients. Among the 69 recipients, 11 recipients who died or underwent reoperation before consciousness recovery were excluded, and 58 recipients (group E: n = 32; group L: n = 26) were enrolled into analysis. Multivariate analysis showed that HE duration >5 days (odds ratio [OR], 15.58; 95% confidence interval [CI], 1.35-179.56; P = .028) and HE type C (OR, 30.90; 95% CI, 1.67-573.48; P = .021) were the independent factors associated with late recovery from HE after LT. CONCLUSIONS: We suggest that recipients with long-duration or type C HE should be carefully managed during the post-transplantation period to prevent deterioration of HE.

Rotational resonance of nonaxisymmetric magnetic braking in the KSTAR tokamak.

One of the important rotational resonances in nonaxisymmetric neoclassical transport has been experimentally validated in the KSTAR tokamak by applying highly nonresonant n=1 magnetic perturbations to rapidly rotating plasmas. These so-called bounce-harmonic resonances are expected to occur in the presence of magnetic braking perturbations when the toroidal rotation is fast enough to resonate with periodic parallel motions of trapped particles. The predicted and observed resonant peak along with the toroidal rotation implies that the toroidal rotation in tokamaks can be controlled naturally in favorable conditions to stability, using nonaxisymmetric magnetic perturbations.

The protective effect of ischemic preconditioning against hepatic ischemic-reperfusion injury under isoflurane anesthesia in rats.

PURPOSE: Apoptosis is a central mechanism of ischemic-reperfusion injury (IRI) to the liver. Among the methods to reduce IRI, ischemic preconditioning (IP) has been shown to confer protection. Therefore, the aim of this study was to determine if IP conferred protection against hepatic IRI under isoflurane anesthesia in rats and to investigate underlying protective mechanisms. MATERIALS AND METHODS: Twenty-three rats weighing 270 to 300 grams were randomly divided into three groups: (1) the sham operated group (n = 5); (2) the non-IP group (n = 9; 45 minutes of hepatic ischemia followed by 2 hours of reperfusion); and (3) the IP group (n = 9); IP induced by 10 minutes of hepatic ischemia followed by 15 minutes of reperfusion before 45 minutes of prolonged hepatic ischemia). Anesthesia was maintained with isoflurane (1.5%). We compared the degrees of hepatic injury and expressions of B cell lymphoma 2 (Bcl-2) and caspase 3 and 8 mRNAs. RESULTS: The IP group showed significantly lower levels of aspartate transaminase and alanine transaminase as well as reduced histological grades of hepatocyte injury compared with the non-IP group at 2 hours after reperfusion. At the corresponding time, the Bcl-2 mRNA level was 2-fold higher in the IP group. Caspase 3 mRNA levels were highest in the non-IP group significantly compared with the sham cohort. Similarly, caspase 8 mRNA levels were highest in the Non_IP group albeit not significancely. CONCLUSION: IP protected against hepatic IRI under isoflurane anesthesia in rats. The mechanism of protection appeared to involve upregulation of Bcl-2 expression resulting in inhibited apoptosis.

Comparison of mixed venous oxygen saturation after in vitro calibration of pulmonary artery catheter with that of pulmonary arterial blood in patients undergoing living donor liver transplantation.

INTRODUCTION: Mixed venous saturation (SvO2) reflects the balance between oxygen delivery and consumption throughout the body. A multifunction pulmonary artery catheter (PAC) can monitor continuous SvO2 after in vitro calibration (CSvO2), obviating the need for in vivo calibration with pulmonary arterial blood. In critically ill patients CSvO2 has shown a good correlation with measured SvO2 of pulmonary arterial blood using co-oximetry (MSvO2). The aim of this study was to compare CSvO2 and MSvO2 in liver transplantation (OLT) recipients. METHODS: We enrolled 44 OLT recipients for comparison with 24 coronary artery bypass graft (CABG) controls free of end-stage liver disease. After anesthetic induction, the PAC was inserted after in vitro calibration and CSvO2 and MSvO2 simultaneously measured. In OLT recipients, additional measurements of CSvO2 and MSvO2 were performed at anhepatic and postreperfusion phases. Pearson's correlation analysis was used to evaluate the correlation between the 2 measurements. A Bland-Altman analysis was used to determine precision of and bias between the 2 measurements. With ±3% regarded to be interchangeable. RESULTS: Cardiac output and intrapulmonary shunt in CABG patients were lower than among OLT recipients. OLT recipients, showed a significant correlation between CSvO2 and MSvO2, but the coefficients were different during the three phases of OLT (r = 0.597, 0.753, and 0.756). In addition, bias values between the two measurements were 6.0%, 6.4%, and 2.9% for the preanhepatic, anhepatic, and postreperfusion phases, respectively, with 29.5%, 31.8%, and 50% of them being interchangeable. In contrast CABG patients showed bias in -0.17% with 75% of measurements interchangeable. CONCLUSION: While in vitro calibration of the PAC can be used in CABG patients, MSvO2 is higher than CSvO2 in OLT recipients. Therefore, in vivo calibration with pulmonary arterial blood is necessary for accurate monitoring of SvO2 in OLT recipients.

Vecuronium requirements according to the operative phase during living donor liver transplantation under desflurane anesthesia.

INTRODUCTION: The requirements of nondepolarizing neuromuscular blocking agent during liver transplantation show conflicting results. We sought to evaluate the requirements according to the operative phase and find extrahepatic factors that influence neuromuscular blocking agent requirements. METHODS: We enrolled 35 patients undergoing living donor liver transplantation. Continuous infusion of vecuronium was adjusted every 15 minutes for consistent neuromuscular blockade aimed at T1/Tc of 0.10 monitored with a neuromuscular transmission module. We compared the mean infusion dose in each phase, and investigated whether it is correlated with preoperative Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh (CTP) score, graft-recipient weight ratio (GRWR), or time to recovery of first twitch response to train-of-four (TOF) stimulation. RESULTS: There was a significant difference between vecuronium doses during each phase (P < .001): 0.48 ± 0.16 µg/kg/min, preanhepatic; 0.38 ± 0.14 µg/kg/min, anhepatic and 0.26 ± 0.07 µg/kg/min, neohepatic phase. There was a significant positive correlation between vecuronium infusion dose in the preanhepatic phase and CTP scores (P = .006, correlation coefficient = 0.465). There was also a significant negative correlation between the time to recovery of first twitch response of TOF stimulation and vecuronium infusion dose in the preanhepatic phase (P = .001, correlation coefficient = -0.546). The infusion dose during the preanhepatic phase was not associated with the MELD score, and that of neohapatic phase not with GRWR. CONCLUSIONS: The vecuronium infusion dose requirement during the anhepatic decreased compared with that in the preanhepatic phase. It further decreased during the neohepatic phase compared with the previous phases. Vecuronium infusion dose reduction is suggested especially during the neohepatic phase for early extubation. The dose during the preanhepatic phase is suggested to be determined considering the CTP score and the time to recovery of the TOF response.