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Although the density of tumor-infiltrating lymphocytes (TILs) is known to be linked to prognosis in various cancers, the prognostic impact and immunologic significance of the spatial heterogeneity of TILs have been rarely investigated. In this study, CD3+ and CD8+ TILs were quantified in independent cohorts (discovery, n = 73; and external validation, n = 93) of colorectal carcinomas (CRCs) with microsatellite instability-high (MSI-H) utilizing whole-slide image analysis of CD3/CD8 immunohistochemistry. The Shannon and Simpson indices, which measure intratumoral patch-to-patch evenness of TIL densities, were used to quantitatively assess the spatial heterogeneity of TILs in each case. To uncover immune-related gene expression signatures of spatial heterogeneity-based TIL subgroups of MSI-H CRCs, representative cases were subjected to GeoMx digital spatial profiler (DSP) analysis. As expected, a low density of TILs was significantly associated with poor disease-free survival (DFS) in MSI-H CRCs. The TIL-low tumors were further classified into two subgroups based on the spatial heterogeneity of TILs: TIL-low/heterogeneity-high and TIL-low/heterogeneity-low subgroups. In both discovery and validation cohorts, the TIL-low/heterogeneity-high, TIL-low/heterogeneity-low, and TIL-high subgroups were significantly associated with poor, intermediate, and good DFS, respectively. In the DSP analysis, the TIL-low/heterogeneity-high subgroup showed higher spatial diversity in the expression of immune-related genes than that of the TIL-low/heterogeneity-low subgroup and exhibited upregulation of genes related to immune checkpoints, chemokine/cytokine receptors, and myeloid cells. TIL-low/heterogeneity-high tumors were also enriched with gene sets related to good response to immune checkpoint inhibitor therapy. In conclusion, TIL-low MSI-H CRCs are prognostically heterogeneous and can be divided into prognostically and immunologically distinct subgroups by considering the spatial heterogeneity of TILs. Our data suggest that intratumoral spatial heterogeneity of TILs can be used as a key element for clinically relevant immunologic subtyping of tumors.

Purpose:Despite the well-known prognostic value of the tumor–immune microenvironment (TIME) in colorectal cancers, objective and readily applicable methods for quantifying tumor-infiltrating lymphocytes (TIL) and the tumor–stroma ratio (TSR) are not yet available.Experimental Design:We established an open-source software-based analytic pipeline for quantifying TILs and the TSR from whole-slide images obtained after CD3 and CD8 IHC staining. Using a random forest classifier, the method separately quantified intraepithelial TILs (iTIL) and stromal TILs (sTIL). We applied this method to discovery and validation cohorts of 578 and 283 stage III or high-risk stage II colorectal cancers patients, respectively, who were subjected to curative surgical resection and oxlaliplatin-based adjuvant chemotherapy.Results:Automatic quantification of iTILs and sTILs showed a moderate concordance with that obtained after visual inspection by a pathologist. The K-means–based consensus clustering of 197 TIME parameters that showed robustness against interobserver variations caused colorectal cancers to be grouped into five distinctive subgroups, reminiscent of those for consensus molecular subtypes (CMS1-4 and mixed/intermediate group). In accordance with the original CMS report, the CMS4-like subgroup (cluster 4) was significantly associated with a worse 5-year relapse-free survival and proved to be an independent prognostic factor. The clinicopathologic and prognostic features of the TIME subgroups have been validated in an independent validation cohort.Conclusions:Machine-learning–based image analysis can be useful for extracting quantitative information about the TIME, using whole-slide histopathologic images. This information can classify colorectal cancers into clinicopathologically relevant subgroups without performing a molecular analysis of the tumors.

Supplementary data

Although the criteria for the indication of endoscopic submucosal dissection (ESD) for undifferentiated early gastric cancer (UD-EGC) have been recently proposed, accumulating reports on the non-negligible rate of lymph node metastasis (LNM) after indicated ESD raise questions on the reliability of the current criteria.To investigate the prevalence and risk factors of LNM in UD-EGC cases meeting the expanded indication for ESD.We retrospectively reviewed 4780 UD-EGC cases that underwent surgical resection between January 2008 and February 2019 at Asan Medical Center, a tertiary university hospital in Korea. To identify the risk factors of LNM of UD-EGC meeting the expanded criteria for ESD, we performed a case-control study by matching the cases with LNM to those without at a ratio of 1:4. We reviewed the clinical, endoscopic, and histologic features of the cases to identify features with a significant difference according to the presence of LNM. Univariate and multivariate logistic regression analyses were performed to estimate the odds ratios (ORs).Of the 4780 UD-EGC cases, 1240 (25.9%) were identified to meet the expanded indication for ESD. Of the 1240 cases, 14 (1.1%) cases had LNM. Among the various clinical, endoscopic, and histopathological features that were evaluated, mixed histology (tumors consisting of 10%-90% of signet ring cells) had a marginally significant association (The risk of LNM is higher than expected when using the current expanded indication for UD-EGC. Histological evaluation could provide useful clues for reducing the risk of LNM.

Days alive and out of hospital (DAOH) is a simple estimator based on the number of days not in hospital within a defined period. In cases of mortality within the period, DAOH is regarded as zero. It has not been validated solely in off-pump coronary artery bypass grafting (OPCAB). This study aimed to demonstrate a correlation between DAOH and outcome of OPCAB. We identified 2211 OPCAB performed from January 2010 to August 2016. We calculated DAOH at 30 and 60 days. We generated a receiver-operating curve and compared outcomes. The median duration of hospital stay after OPCAB was 6 days. The median DAOH values at 30 and 60 days were 24 and 54 days. The estimated thresholds for 3-year mortality for DAOH at 30 and 60 days were 20 and 50 days. Three-year mortality was higher for short DAOH (1.2% vs. 5.7% and 1.1% vs. 5.6% DAOH at 30 and 60 days). After adjustment, the short DAOH 30 group showed significantly higher mortality during 3-year follow-up (hazard ratio 3.07; 95% confidence interval 1.45–6.52; p = 0.004). DAOH at 30 days after OPCAB showed a correlation with 3-year outcomes. DAOH 30 might be a reliable long-term outcome measure that can be obtained within 30 days after surgery.

Neuregulin-1 (NRG1) is an epidermal growth factor family member with essential roles in the developing and adult nervous systems. In recent years, establishing evidence has collectively suggested that NRG1 is a new modulator of central nervous system (CNS) injury and disease, with multifaceted roles in neuroprotection, remyelination, neuroinflammation, and other repair mechanisms. NRG1 signaling exerts its effects via the tyrosine kinase receptors ErbB2-ErbB4. The NRG1/ErbB network in CNS pathology and repair has evolved, primarily in recent years. In the present study, we demonstrated that a unilateral microinjection of CoCl

Background: Patients with chronic liver disease (CLD) planned for liver transplantation (LT) often show severe thrombocytopenia, but there is a lack of evidence in deciding the threshold for prophylactic platelet transfusion.Case: A 47-year-old women with acute liver failure was referred for LT. Despite daily transfusion of platelets, platelet counts remained under 10,000/µl. During LT, 2 units of single donor platelets (SDP) were transfused. Although platelet counts remained extremely low (3,000–4,000/µl) no diffuse oozing was observed and the blood loss was 860 ml. Postoperatively, there was no sign of active bleeding or oozing, and the patient received only 1 unit SDP transfusion.Conclusions: CLD patients may have severe thrombocytopenia. However, primary hemostasis may not be significantly hindered due to the existence of rebalanced hemostasis. Prophylactic platelet transfusion in these patients should not be decided based on platelet counts only, but also take other coagulation tests and clinical signs into consideration.

Background: The allocation policy for deceased donor livers in Korea was changed in June 2016 from Child-Turcotte-Pugh (CTP) scoring system-based to Model for End-stage Liver Disease (MELD) scoring system-based. Thus, it is necessary to review the effect of allocation policy changes on anesthetic management.Methods: Medical records of deceased donor liver transplantation (DDLT) from December 2014 to May 2017 were reviewed. We compared the perioperative parameters before and after the change in allocation policy.Results: Thirty-seven patients underwent DDLT from December 2014 to May 2016 (CTP group), and 42 patients underwent DDLT from June 2016 to May 2017 (MELD group). The MELD score was significantly higher in the MELD group than in the CTP group (36.5 ± 4.6 vs. 26.5 ± 9.4, P < 0.001). The incidence of hepatorenal syndrome (HRS) was higher in the MELD group than in the CTP group (26 vs. 7, P < 0.001). Packed red blood cell transfusion occurred more frequently in the MELD group than in the CTP group (5.0 ± 3.6 units vs. 3.4 ± 2.2 units, P = 0.025). However, intraoperative bleeding, vasopressor support, and postoperative outcomes were not different between the two groups.Conclusions: Even though the patient’s objective condition deteriorated, perioperative parameters did not change significantly.

Lymphovascular invasion (LVI) is a high-risk feature guiding decision making for adjuvant chemotherapy. We evaluated the prognostic importance and reliability of LVI as an adjuvant chemotherapy indicator in 1634 patients with pT3N0 colorectal cancer treated with curative radical resection between 2012 and 2016. LVI and perineural invasion (PNI) were identified in 382 (23.5%) and 269 (16.5%) patients, respectively. In total, 772 patients received adjuvant chemotherapy. The five-year recurrence-free survival (RFS) and OS rates were 92% and 94.8%, respectively. Preoperative obstruction, PNI, and positive margins were significantly associated with RFS and OS; however, adjuvant chemotherapy and LVI were not. Pathologic slide central reviews of 242 patients using dual D2-40 and CD31 immunohistochemical staining was performed. In the review cohort, the diagnosis of LVI and PNI was changed in 82 (33.9%) and 61 (25.2%) patients, respectively. Reviewed LVI, encompassing small vessel invasion, lymphatic invasion, and large vessel invasion, was not an independent risk factor associated with OS but was related to RFS. The prognostic importance of LVI and adjuvant chemotherapy was not defined because LVI may be underrecognized in pathologic diagnoses using hematoxylin and eosin staining slides only, leading to low recurrence rate predictions. Using LVI as a guiding factor for adjuvant chemotherapy requires further consideration.

It has been suggested that Fusobacterium nucleatum (Fn) may differentially impact tumor immune responses according to microsatellite instability (MSI) status in colorectal cancers (CRCs). We aimed to reveal the detailed relationship between intratumoral Fn and immune microenvironmental features in MSI-high CRCs. A total of 126 MSI-high CRCs were subjected to analyses for intratumoral Fn DNA load using quantitative PCR and for densities of tumor-infiltrating immune cells, including CD3+ T cells, CD4+ T cells, CD8+ T cells, FoxP3+ T cells, CD68+ macrophages, CD163+ macrophages, and CD177+ neutrophils, at invasive margin (IM) and center of tumor (CT) areas using computational image analysis of immunohistochemistry. Based on the Fn load, the 126 MSI-high CRCs were classified into Fn-high, -low, and -negative subgroups. The Fn-high subset of MSI-high CRCs was significantly correlated with larger tumor size and advanced invasion depth (p = 0.017 and p = 0.034, respectively). Compared with the Fn-low/negative subgroup, Fn-high tumors demonstrated significantly lower density of FoxP3+ cells in both IM and CT areas (p = 0.002 and p = 0.003, respectively). Additionally, Fn-high was significantly associated with elevated CD163+ cell to CD68+ cell ratio in only CT areas of MSI-high CRCs (p = 0.028). In conclusion, the Fn-enriched subset of MSI-high CRCs is characterized by increased tumor growth and invasion and distinct immune microenvironmental features, including decreased FoxP3+ T cells throughout the tumor and increased proportion of M2-polarized macrophages in the tumor center. These findings collectively support that Fn may be linked to pro-tumoral immune responses in MSI-high CRCs.

Polyimide membranes have been widely investigated in gas separation applications due to their high separation abilities, excellent processability, relatively low cost, and stabilities. Unfortunately, it is extremely challenging to simultaneously achieve both improved gas permeability and selectivity due to the trade-off relationship in common polymer membranes. Diamine modification is a simple strategy to tune the separation performance of polyimide membranes, but an excessive loss in permeability is also generally observed. In the present work, we reported the effects of diamine type (i.e., non-fluorinated and fluorinated) on the physicochemical properties and the corresponding separation performance of a modified membrane using a commercial Matrimid

Increased vasoactive-inotropic score (VIS) is a reliable predictor of mortality and morbidity after cardiac surgery. Here, we retrospectively evaluated the association between VIS and adverse outcomes in adult patients after off-pump coronary artery bypass grafting (OPCAB). We included 2149 patients who underwent OPCAB. The maximal VIS was calculated for the initial 48 postoperative hours using standard formulae. The primary outcome was 1-year death. The composite adverse outcome was death, resuscitation or mechanical support, myocardial infarction, revascularization, new-onset atrial fibrillation, infection requiring antibacterial therapy, acute kidney injury, and stroke. Path-analysis was conducted using lactate and prognostic nutritional index (PNI). VIS was associated with 1-year death (odds ratio [OR] 1.07 [1.04–1.10], p p = 0.008). In path-analysis, high VIS showed a direct effect on the increased risk of 1-year death and composite outcome. In the pathway using lactate as a mediating variable, VIS showed an indirect effect on the composite outcome but no significant effect on death. Low PNI directly affected the increased risk of 1-year death and composite outcome, and had an indirect effect on both outcomes, even when VIS was used as a mediating variable. In patients undergoing OPCAB, high VIS independently predicted morbidity and 1-year death. Patients with increased lactate levels following high VIS had an increased risk of postoperative complications, although not necessarily resulting in death. However, patients with poor preoperative nutritional status had an increased risk of unfavourable outcomes, including death, implying the importance of preoperative nutritional support.

Background SMAD family member 4 (SMAD4) has gained attention as a promising prognostic factor of colorectal cancer (CRC) as well as a key molecule to understand the tumorigenesis and progression of CRC. Methods We retrospectively analyzed 1,281 CRC cases immunohistochemically for their expression status of SMAD4, and correlated this status with clinicopathologic and molecular features of CRCs. Results A loss of nuclear SMAD4 was significantly associated with frequent lymphovascular and perineural invasion, tumor budding, fewer tumor-infiltrating lymphocytes, higher pT and pN category, and frequent distant metastasis. In contrast, tumors overexpressing SMAD4 showed a significant association with sporadic microsatellite instability. After adjustment for TNM stage, tumor differentiation, adjuvant chemotherapy, and lymphovascular invasion, the loss of SMAD4 was found to be an independent prognostic factor for worse 5-year progression-free survival (hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.01 to 1.60; p=.042) and 7-year cancerspecific survival (HR, 1.45; 95% CI, 1.06 to 1.99; p=.022). Conclusions We confirmed the value of determining the loss of SMAD4 immunohistochemically as an independent prognostic factor for CRC in general. In addition, we identified some histologic and molecular features that might be clues to elucidate the role of SMAD4 in colorectal tumorigenesis and progression.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Excitatory amino acid carrier 1 (EAAC1) is an important subtype of excitatory amino acid transporters (EAATs) and is the route for neuronal cysteine uptake. CoCl2 is not only a hypoxia-mimetic reagent but also an oxidative stress inducer. Here, we found that CoCl2 induced significant EAAC1 overexpression in SH-SY5Y cells and the hippocampus of mice. Transient transfection of EAAC1 reduced CoCl2-induced cytotoxicity in SH-SY5Y cells. Based on this result, upregulation of EAAC1 expression by CoCl2 is thought to represent a compensatory response against oxidative stress in an acute hypoxic state. We further demonstrated that pretreatment with Neuregulin-1 (NRG1) rescued CoCl2-induced upregulation of EAAC1 and tau expression. NRG1 plays a protective role in the CoCl2-induced accumulation of reactive oxygen species (ROS) and reduction in antioxidative enzyme (SOD and GPx) activity. Moreover, NRG1 attenuated CoCl2-induced apoptosis and cell death. NRG1 inhibited the CoCl2-induced release of cleaved caspase-3 and reduction in Bcl-XL levels. Our novel finding suggests that NRG1 may play a protective role in hypoxia through the inhibition of oxidative stress and thereby maintain normal EAAC1 expression levels.

Excitatory amino acid carrier 1 (EAAC1) is an important subtype of excitatory amino acid transporters (EAATs) and is the route for neuronal cysteine uptake. CoCl2 is not only a hypoxia-mimetic reagent but also an oxidative stress inducer. Here, we found that CoCl2 induced significant overexpression of EAAC1 in a dose- and time-dependent manner. We further demonstrated that pretreatment with NRG1 rescued the CoCl2-induced upregulation of EAAC1 and tau expression. Neuregulin-1 (NRG1) plays a protective role in the CoCl2-induced accumulation of reactive oxygen species (ROS) and reduction in antioxidative enzyme (SOD and Gpx) activity. Moreover, NRG1 attenuated CoCl2-induced apoptosis and cell death. NRG1 inhibited the CoCl2-induced release of cleaved caspase-3 and reduction in Bcl-XL. Our novel findings suggest that NRG1 may play a protective role in oxidative stress and hypoxia through the regulation of EAAC1.

Neonatal maternal separation (NMS), as an early-life stress (ELS), is a risk factor to develop emotional disorders. However, the exact mechanisms remain to be defined. In the present study, we investigated the mechanisms involved in developing emotional disorders caused by NMS. First, we confirmed that NMS provoked impulsive behavior, orienting and nonselective attention-deficit, abnormal grooming, and depressive-like behaviors in adolescence. Excitatory amino acid carrier 1 (EAAC1) is an excitatory amino acid transporter expressed specifically by neurons and is the route for the neuronal uptake of glutamate/aspartate/cysteine. Compared with that in the normal control group, EAAC1 expression was remarkably reduced in the ventral hippocampus and cerebral cortex in the NMS group. Additionally, EAAC1 expression was reduced in parvalbumin-positive hippocampal GABAergic neurons in the NMS group. We also found that EAAC1-knockout (EAAC1−/−) mice exhibited impulsive-like, nonselective attention-deficit, and depressive-like behaviors compared with WT mice in adolescence, characteristics similar to those of the NMS behavior phenotype. Taken together, our results revealed that ELS induced a reduction in EAAC1 expression, suggesting that reduced EAAC1 expression is involved in the pathophysiology of attention-deficit and depressive behaviors in adolescence caused by NMS.

In 2015, we experienced the largest in-hospital Middle East respiratory syndrome (MERS) outbreak outside the Arabian Peninsula. We share the infection prevention measures for surgical procedures during the unexpected outbreak at our hospital. We reviewed all forms of related documents and collected information through interviews with healthcare workers of our hospital. After the onset of outbreak, a multidisciplinary team devised institutional MERS-control guidelines. Two standard operating rooms were converted to temporary negative-pressure rooms by physically decreasing the inflow air volume (−4.7 Pa in the main room and −1.2 Pa in the anteroom). Healthcare workers were equipped with standard or enhanced personal protective equipment according to the MERS-related patient’s profile and symptoms. Six MERS-related patients underwent emergency surgery, including four MERS-exposed and two MERS-confirmed patients. Negative conversion of MERS-CoV polymerase chain reaction tests was noticed for MERS-confirmed patients before surgery. MERS-exposed patients were also tested twice preoperatively, all of which were negative. All operative procedures in MERS-related patients were performed without specific adverse events or perioperative MERS transmission. Our experience with setting up a temporary negative-pressure operation room and our conservative approach for managing MERS-related patients can be referred in cases of future unexpected MERS outbreaks in non-endemic countries.

Since the inception of membrane-based CO2 separation technology in the late 1970s, a large number of material studies have been performed to improve the material properties of membrane materials and tremendous progress has been made with regard to CO2 separation to increase the trade-off between permeability and selectivity, known as the “Robeson upper bound.” In membrane science, material properties and membrane properties are related but completely different, especially in thin-film composite (TFC) membranes. Compared to the large number of material studies, few studies have been performed on membrane properties, and very few membranes have been successfully commercialized because an extremely thin selective layer is required in CO2/N2 separation membranes for high CO2 permeance; however, defects are easily generated, deteriorating gas transport properties on a large-scale. In this study, we theoretically analyzed the effect of defects on the gas transport properties of a TFC membrane and introduced a method to control defects during the preparation of large-scale membranes. This work will provide a facile and practical approach to preparing TFC membranes and will be helpful toward extending material studies to real membrane demonstrations.

BackgroundColorectal cancers (CRCs) with microsatellite instability-high (MSI-H) are hypermutated tumors and are generally regarded as immunogenic. However, their heterogeneous immune responses and underlying molecular characteristics remain largely unexplained.MethodsWe conducted a retrospective analysis of 73 primary MSI-H CRC tissues to characterize heterogeneous immune subgroups. Based on combined tumor-infiltrating lymphocyte (TIL) immunoscore and tertiary lymphoid structure (TLS) activity, MSI-H CRCs were classified into immune-high, immune-intermediate, and immune-low subgroups. Of these, the immune-high and immune-low subgroups were further analyzed using whole-exome and transcriptome sequencing.ResultsWe found considerable variations in immune parameters between MSI-H CRCs, and immune subgrouping of MSI-H CRCs was performed accordingly. The TIL densities and TLS activities of immune-low MSI-H CRCs were comparable to those of an immune-low or immune-intermediate subgroup of microsatellite-stable CRCs. There were remarkable differences between immune-high and immune-low MSI-H CRCs, including their pathological features (medullary vs mucinous), genomic alterations (tyrosine kinase fusions vs KRAS mutations), and activated signaling pathways (immune-related vs Wnt and Notch signaling), whereas no significant differences were found in tumor mutational burden (TMB) and neoantigen load. The immune-low MSI-H CRCs were subdivided by the consensus molecular subtype (CMS1 vs CMS3) with different gene expression signatures (mesenchymal/stem-like vs epithelial/goblet-like), suggesting distinct immune evasion mechanisms. Angiogenesis and CD200 were identified as potential therapeutic targets in immune-low CMS1 and CMS3 MSI-H CRCs, respectively.ConclusionsMSI-H CRCs are immunologically heterogeneous, regardless of TMB. The unusual immune-low MSI-H CRCs are characterized by mucinous histology, KRAS mutations, and Wnt/Notch activation, and can be further divided into distinct gene expression subtypes, including CMS4-like CMS1 and CMS3. Our data provide novel insights into precise immunotherapeutic strategies for subtypes of MSI-H tumors.

Objective To examine whether color parameters of tongue inspection (TI) using a digital camera was reliable and valid, and to examine which color parameters serve as predictors of symptom patterns in terms of East Asian medicine (EAM). Methods Two hundred female subjects' tongue substances were photographed by a mega-pixel digital camera. Together with the photographs, the subjects were asked to complete Yin deficiency, Phlegm pattern, and Cold-Heat pattern questionnaires. Using three sets of digital imaging software, each digital image was exposure- and white balance-corrected, and finally L* (luminance), a* (red-green balance), and b* (yellow-blue balance) values of the tongues were calculated. To examine intra- and inter-rater reliabilities and criterion validity of the color analysis method, three raters were asked to calculate color parameters for 20 digital image samples. Finally, four hierarchical regression models were formed. Results Color parameters showed good or excellent reliability (0.627-0.887 for intra-class correlation coefficients) and significant criterion validity (0.523-0.718 for Spearman's correlation). In the hierarchical regression models, age was a significant predictor of Yin deficiency (β = 0.192), and b* value of the tip of the tongue was a determinant predictor of Yin deficiency, Phlegm, and Heat patterns (β = − 0.212, − 0.172, and − 0.163). Luminance (L*) was predictive of Yin deficiency (β = − 0.172) and Cold (β = 0.173) pattern. Conclusion Our results suggest that color analysis of the tongue using the L*a*b* system is reliable and valid, and that color parameters partially serve as symptom pattern predictors in EAM practice.

Background The unexpected displacement of the endotracheal tube (ETT) as a result of neck movements can cause endobronchial intubation and accidental extubation. The ETT is subject to movement even after its proper placement has been confirmed either clinically or radiographically. Methods One-hundred-seven children (2-8 yr) were divided randomly into three groups. In Group I, the ETT was entered into the main bronchus and withdrawn until equal sounds in both lung were heard, and then withdrawn 2 cm. In Group II, the ETT position was determined by placing the prescribed marks on the ETT at the level of the vocal cords, and in Group III, by palpating the ETT tip at the suprasternal notch. In all groups, the distance between the ETT tip and the carina was measured using a fiberoptic bronchoscope. The relative ETT tip position along the trachea (carina; 0%, vocal cords; 100%) was assessed in each position during neck movement. Results The relative position of the ETT with the patient in the neutral position in Groups I, II, and III was 21.4% +/- 6.7%, 46.5% +/- 13.0%, and 43.4% +/- 11.1%, respectively. In Group I, the relative ETT position after flexion was 9.5% +/- 10.3%, and endobronchial intubation was observed in five children (14.3%). There was no extubation or endobronchial intubation in the other two groups. Conclusions Positioning the ETT by auscultation places the ETT more deeply than the midtrachea, which can increase the risk of endobronchial intubation during neck flexion.

Background: An increasing number of cases of target-controlled infusion (TCI) of propofol have substituted 2% propofol for 1% due to the concerns about lipid deposition and the practical convenience. However, 2% propofol may possess a higher proportion of free aqueous propofol because of the relatively decreased lipid-solvent ratio as compared to that for 1% propofol. We performed a prospective, randomized, double-blind trial to evaluate the pain of 1% and 2% propofol TCI. The efficacy of lidocaine pretreatment to abolish the pain was also tested for each concentration of propofol. Methods: Two hundred adult patients were randomly allocated to 4 groups according to the pretreatment drugs and propofol concentrations; placebo (normal saline) and 1% propofol group (group 1), placebo and 2% propofol group (group 2), lidocaine and 1% propofol group (group 1L), and lidocaine and 2% propofol group (group 2L). Administration of pretreatment drug was followed by TCI with using each concentration of propofol. Pain was assessed using a four-point scale during propofol infusion. Results: Propofol pain was more frequent (82% vs. 63%, respectively, P = 0.026), and severe (P = 0.002) for the group 2 than for group 1. Pain was significantly reduced by lidocaine pretreatment in the group 2L (48%) and group 1L (19%), as compared with group 2 (82%) and group 1 (63%), respectively (P ＜ 0.001, both). However, group 2L still showed considerable pain that was similar to the pain of group 1. Conclusions: TCI of 2% propofol caused more frequent and severe pain despite of lidocaine pretreatment. (Korean J Anesthesiol 2008; 55: 675～9)

We report a patient who developed a large subcutaneous hematoma during internal jugular vein catheterization. We usually find the internal jugular vein by advancing the needle along the medial border of the lateral head of the sternocleidomastoid muscle. The external jugular vein should be identified to avoid puncture. But the external jugular vein is known to exhibit variations in its formation and course. During internal jugular catheterization especially for advanced venous access, identifying the external jugular vein by sono probe may be important. (Korean J Anesthesiol 2008; 54: 563∼5)

Background: We investigated the effect of spinal cord stimulation on intractable chronic pain retrospectively and report our 5-year experience.Methods: 49 patients with the medical history of trial spinal cord stimulation have been retrospectively analyzed. They consist of 34 men and 15 women, ranging in age from 22 to 89 years. Causes of intractable chronic pain included postherpetic neuralgia, failed back surgery syndrome, complex regional pain syndrome, chronic back and leg pain, cauda equina syndrome, perineal pain, diabetic polyneuropathy, and spinal cord injury.Results: The pain due to failed back surgery syndrome, complex regional pain syndrome, chronic low back and leg pain, and spinal cord injury was well controlled by using spinal cord stimulation system. After a trial period of stimulation, 20 patients had permanent stimulators implanted. Most of them reported satisfactory pain relief for maximum 60 months and minimum 9 months. Noticeable complications included electrode displacement and hemorrhage. Conclusions: We may suggest that spinal cord stimulation is an effective and safe therapy for chronic intractable pain.

Background: Self inflating resuscitators are widely used for the patients who need positive pressure ventilation during transport. During self inflating resuscitator ventilation, the may decreases even with the use of the oxygen reservoir. Such phenomenon may increase the difficulty and risk of transport of the critically ill patients. Twin self inflating resuscitator was assembled by being modified from two conventional ones to achieve more stable . Methods: The twin self inflating resuscitator and one conventional adult self inflating resuscitator were tested on a test lung. In the twin resuscitator, two adult self inflating resuscitators were connected serially without distal unidirectional valve plate. The resuscitators were compressed at variable tidal volumes, respiratory rates and oxygen flow rates, guided by the monitor. Results: With conventional self inflating resuscitator ventilation, the was maintained over 95% until minute ventilation of at respectively 5, 10, 15 L/min oxygen flow rate. With serial type, the started to decrease with the minute ventilation over at 5, 10, 15 L/min oxygen flow rate. Conclusions: By simple connection of two self inflating resuscitators, the during self inflating resuscitator ventilation could be maintained during almost two times of minute ventilation compared to conventional ones.