Association between hepatic steatosis and the development of hepatocellular carcinoma in patients with chronic hepatitis B

BACKGROUND/AIMS: Nonalcoholic fatty liver disease (NAFLD) is becoming a worldwide epidemic, and is frequently found in patients with chronic hepatitis B (CHB). We investigated the impact of histologically proven hepatic steatosis on the risk for hepatocellular carcinoma (HCC) in CHB patients without excessive alcohol intake. METHODS: Consecutive CHB patients who underwent liver biopsy from January 2007 to December 2015 were included. The association between hepatic steatosis (≥ 5%) and subsequent HCC risk was analyzed. Inverse probability weighting (IPW) using the propensity score was applied to adjust for differences in patient characteristics, including metabolic factors. RESULTS: Fatty liver was histologically proven in 70 patients (21.8%) among a total of 321 patients. During the median (interquartile range) follow-up of 5.3 (2.9–8.3) years, 17 of 321 patients (5.3%) developed HCC: 8 of 70 patients (11.4%) with fatty liver and 9 of 251 patients (3.6%) without fatty liver. The five-year cumulative incidences of HCC among patients without and with fatty liver were 1.9% and 8.2%, respectively (P=0.004). Coexisting fatty liver was associated with a higher risk for HCC (adjusted hazards ratio [HR], 3.005; 95% confidence interval [CI], 1.122–8.051; P=0.03). After balancing with IPW, HCC incidences were not significantly different between the groups (P=0.19), and the association between fatty liver and HCC was not significant (adjusted HR, 1.709; 95% CI, 0.404–7.228; P=0.47). CONCLUSIONS: Superimposed NAFLD was associated with a higher HCC risk in CHB patients. However, the association between steatosis per se and HCC risk was not evident after adjustment for metabolic factors.

Immunomodulatory Effects of Placenta-derived Mesenchymal Stem Cells on T Cells by Regulation of FoxP3 Expression

The immunomodulatory effects of mesenchymal stem cells (MSCs) are an important mediator of their therapeutic effects in stem cell therapy and regenerative medicine. The regulation mechanism of MSCs is orchestrated by several factors in both intrinsic and extrinsic events. Recent studies have shown that the dynamic expression of cytokines secreted from MSCs control T cell function and maturation by regulating the expression of FoxP3, which figures prominently in T cell differentiation. However, there is no evidence that placenta-derived mesenchymal stem cells (PD-MSCs) have strong immunomodulatory effects on T cell function and maturation via FoxP3 expression. Therefore, we compared the expression of FoxP3 in activated T cells isolated from peripheral blood and co-cultured with PD-MSCs or bone marrow-derived mesenchymal stem cells (BM-MSCs) and analyzed their effect on T cell proliferation and cytokine profiles. Additionally, we verified the immunomodulatory function of PD-MSCs by siRNA-mediated silencing of FoxP3. MSCs, including PD-MSCs and BM-MSCs, promoted differentiation of naive peripheral blood T cells into CD4+CD25+FoxP3+ regulatory T (Treg) cells. Intriguingly, the population of CD4+CD25+FoxP3+ Treg cells co-cultured with PD-MSCs was significantly expanded in comparison to those co-cultured with BM-MSCs or WI38 cells (p < 0.05, p < 0.001). Dynamic expression patterns of several cytokines, including anti- and pro-inflammatory cytokines and members of the transforming growth factor-beta (TGF-β) family secreted from PD-MSCs according to FoxP3 expression were observed. The results suggest that PD-MSCs have an immunomodulatory effect on T cells by regulating FoxP3 expression.

Is Helicobacter pylori Associated Functional Dyspepsia Correlated With Dysbiosis?

BACKGROUND/AIMS: To assess the long-term effect of Helicobacter pylori eradication on symptomatic improvement according to the type of antibiotic and the duration of treatment in H. pylori-associated functional dyspepsia. METHODS: We searched Pubmed, Embase, CINAHL, and the Cochrane library databases for randomized controlled trials written in English and undertaken up to August 2016 that met our eligibility criteria. The search methodology used combinations of the following keywords: Helicobacter pylori OR H. pylori OR HP; dyspepsia OR functional dyspepsia OR non-ulcer dyspepsia; eradication OR cure OR treatment. The study outcome was the summary odds ratio (OR) for symptomatic improvement in H. pylori-associated functional dyspepsia with successful eradication therapy. Subgroup analyses were performed based on the type of antibiotic, and the duration of treatment, whether or not patients had symptoms of irritable bowel syndrome, and on race. RESULTS: Sixteen randomized controlled trials met the inclusion criteria. The summary OR for symptomatic improvement in patients in our eradication group was 1.33 (95% confidence interval [CI], 1.16–1.54; P < 0.01). In a subgroup analysis on type of antibiotic, symptomatic improvement with metronidazole-containing regimen (OR, 1.87; 95% CI, 1.26–2.77) was better than treatment with clarithromycin (OR, 1.29; 95% CI, 1.11–1.50). H. pylori eradication therapy given for 10–14 days was the more effective for symptom improvement than 7-day therapy. When the studies excluding irritable bowel syndrome cases were analyzed, there were no therapeutic effects of H. pylori eradication on symptomatic improvement. CONCLUSIONS: In the clinical setting, the most effective H. pylori eradication regimen for functional dyspepsia to provide relief of symptoms is a metronidazole-based treatment regimen for at least 10 days. The explanation for this is that H. pylori-associated functional dyspepsia could be associated with dysbiosis.

Percutaneous radiologic gastrostomy in patients with failed percutaneous endoscopic gastrostomy

BACKGROUND: To determine the technical feasibility and success rate of percutaneous radiologic gastrostomy (PRG) after failure of percutaneous endoscopic gastrostomy (PEG). METHODS: Consecutive patients referred for PRG after failure of PEG between May 2011 and June 2016 were included in this study. The reasons for the failure of PEG, as well as the technical success and complications of PRG were noted. RESULTS: Fifteen patients (14 men, 1 woman; age, 27-93 years) were included. The most common reasons for PEG failure were esophageal stricture due to malignancies (n = 8), unfavorable abdominal wall conditions (n = 3), unstable patient condition during endoscopy (n = 2), and other miscellaneous conditions (n = 2). PRG placement was technically successful in all 15 cases. In one case, early slip-out of the gastrostomy tube occurred, which required removal and repositioning. No mortality was noted. CONCLUSION: PRG is technically feasible in patients with failed PEG insertion, and has advantages over PEG and a high overall success rate.

Pharmacokinetic characteristics of cilostazol 200 mg controlled-release tablet compared with two cilostazol 100 mg immediate-release tablets (Pletal) after single oral dose in healthy Korean male volunteers

Cilostazol controlled-release (CR) tablets have recently been developed by Korea United Pharm (Seoul, Korea). The tablets use a patented double CR system, which improves drug compliance by allowing "once daily" administration and reduces adverse events by sustaining a more even plasma concentration for 24 h. We conducted an open, randomized, two-period, two-treatment, crossover study to compare the pharmacokinetic (PK) characteristics and tolerability of cilostazol when administered to healthy Korean male volunteers as CR or immediate release (IR) tablets (Pletal, Korea Otsuka Pharmaceutical Co., Gyeonggi-do, Korea). Each volunteer was randomly allocated to receive a single tablet of cilostazol CR (200 mg) or two tablets of cilostazol IR (100 mg) with a 7-day washout period between treatments. Plasma cilostazol, OPC-13015 (3,4-dehydrocilostazol), and OPC-13213 (4'-trans-hydroxycilostazol) were assayed using liquid chromatography-tandem mass spectrometry for PK analysis. Thirty participants completed the study with no clinically relevant safety issues. The peak concentrations (C(max), mean ± SD) of cilostazol CR and cilostazol IR were 1414.6 ± 49.3 and 1413.1 ± 35.2 ng/mL, respectively, and the areas under the plasma concentration-time curve from 0 to the last concentration (AUC(last)) were 23928.7 ± 65.9 and 25312.0 ± 62.6 ng·h/mL, respectively. The geometric mean ratios (cilostazol CR/cilostazol IR, GMR) of the C(max) and AUC(last) values were 1.001 (90% CI: 0.822, 1.220) and 0.945 (90% CI: 0.814, 1.098), respectively. The frequencies of adverse events were similar. The present study showed that cilostazol PK and tolerability were comparable when administered to healthy Korean men, regardless of whether administered as cilostazol CR or IR.

Accuracy and precision of integumental linear dimensions in a three-dimensional facial imaging system / 대한치과교정학회지

OBJECTIVE: A recently developed facial scanning method uses three-dimensional (3D) surface imaging with a light-emitting diode. Such scanning enables surface data to be captured in high-resolution color and at relatively fast speeds. The purpose of this study was to evaluate the accuracy and precision of 3D images obtained using the Morpheus 3D(R) scanner (Morpheus Co., Seoul, Korea). METHODS: The sample comprised 30 subjects aged 24-34 years (mean 29.0 +/- 2.5 years). To test the correlation between direct and 3D image measurements, 21 landmarks were labeled on the face of each subject. Sixteen direct measurements were obtained twice using digital calipers; the same measurements were then made on two sets of 3D facial images. The mean values of measurements obtained from both methods were compared. To investigate the precision, a comparison was made between two sets of measurements taken with each method. RESULTS: When comparing the variables from both methods, five of the 16 possible anthropometric variables were found to be significantly different. However, in 12 of the 16 cases, the mean difference was under 1 mm. The average value of the differences for all variables was 0.75 mm. Precision was high in both methods, with error magnitudes under 0.5 mm. CONCLUSIONS: 3D scanning images have high levels of precision and fairly good congruence with traditional anthropometry methods, with mean differences of less than 1 mm. 3D surface imaging using the Morpheus 3D(R) scanner is therefore a clinically acceptable method of recording facial integumental data.

Lymphangiography to Treat Postoperative Lymphatic Leakage: A Technical Review

In addition to imaging the lymphatics and detecting various types of lymphatic leakage, lymphangiography is a therapeutic option for patients with chylothorax, chylous ascites, and lymphatic fistula. Percutaneous thoracic duct embolization, transabdominal catheterization of the cisterna chyli or thoracic duct, and subsequent embolization of the thoracic duct is an alternative to surgical ligation of the thoracic duct. In this pictorial review, we present the detailed technique, clinical applications, and complications of lymphangiography and thoracic duct embolization.

Percutaneous Radiologic Gastrostomy Using the One-Anchor Technique in Patients after Partial Gastrectomy

OBJECTIVE: The purpose of our study was to assess the feasibility of performing percutaneous radiologic gastrostomy (PRG) in patients who had undergone partial gastrectomy and to evaluate factors associated with technical success. MATERIALS AND METHODS: Nineteen patients after partial gastrectomy, who were referred for PRG between April 2006 and April 2012, were retrospectively analyzed. The remnant stomach was punctured using a 21-gauge Chiba-needle. A single anchor was used for the gastropexy and a 12-Fr or 14-Fr gastrostomy tube was inserted. Data were collected regarding the technical success, procedure time, and presence of any complications. Univariable analyses were performed to determine the factors related to the technical success. RESULTS: Percutaneous radiologic gastrostomy was technically successful in 10 patients (53%), while a failed attempt and failure without an attempt were observed in 5 (26%) and 4 (21%) patients, respectively. Percutaneous radiologic jejunostomy was successfully performed in 9 patients who experienced technical failure. In the 10 successful PRG cases, the mean procedure time was 6.35 minutes. Major complications occurred in 2 patients, tube passage through the liver and pneumoperitonum in one and severe hemorrhage in the other. The technical success rate was higher in patients with Billroth I gastrectomy (100%, 6/6) than in patients with Billroth II gastrectomy (31%, 4/13) (p = 0.011). CONCLUSION: Percutaneous radiologic gastrostomy can be successfully performed using the one-anchor technique in approximately half of the patients after partial gastrectomy.

Exposure and Toxicity Assessment of Ultrafine Particles from Nearby Traffic in Urban Air in Seoul, Korea

OBJECTIVES: We investigated the particle mass size distribution and chemical properties of air pollution particulate matter (PM) in the urban area and its capacity to induce cytotoxicity in human bronchial epithelial (BEAS-2B) cells. METHODS: To characterize the mass size distributions and chemical concentrations associated with urban PM, PM samples were collected by a 10-stage Micro-Orifice Uniform Deposit Impactor close to nearby traffic in an urban area from December 2007 to December 2009. PM samples for in vitro cytotoxicity testing were collected by a mini-volume air sampler with PM10 and PM2.5 inlets. RESULTS: The PM size distributions were bi-modal, peaking at 0.18 to 0.32 and 1.8 to 3.2 microm. The mass concentrations of the metals in fine particles (0.1 to 1.8 microm) accounted for 45.6 to 80.4% of the mass concentrations of metals in PM10. The mass proportions of fine particles of the pollutants related to traffic emission, lead (80.4%), cadmium (69.0%), and chromium (63.8%) were higher than those of other metals. Iron was the dominant transition metal in the particles, accounting for 64.3% of the PM10 mass in all the samples. We observed PM concentration-dependent cytotoxic effects on BEAS-2B cells. CONCLUSIONS: We found that exposure to PM2.5 and PM10 from a nearby traffic area induced significant increases in protein expression of inflammatory cytokines (IL-6 and IL-8). The cell death rate and release of cytokines in response to the PM2.5 treatment were higher than those with PM10. The combined results support the hypothesis that ultrafine particles from vehicular sources can induce inflammatory responses related to environmental respiratory injury.

Cerebral Oxygenation during Laparoscopic Surgery: Jugular Bulb versus Regional Cerebral Oxygen Saturation

PURPOSE: We hypothesized that regional cerebral oxygen saturation (rSO2) could replace jugular bulb oxygen saturation (SjvO2) in the steep Trendelenburg position under pneumoperitoneum. Therefore, we evaluated the relationship between SjvO2 and rSO2 during laparoscopic surgery. MATERIALS AND METHODS: After induction of anesthesia, mechanical ventilation was controlled to increase PaCO2 from 35 to 45 mm Hg in the supine position, and the changes in SjvO2 and rSO2 were measured. Then, after establishment of pneumoperitoneum and Trendelenburg position, ventilation was controlled to maintain a PaCO2 at 35 mm Hg and the CO2 step and measurements were repeated. The changes in SjvO2 (rSO2) -CO2 reactivity were compared in the supine position and Trendelenburg-pneumoperitoneum condition, respectively. RESULTS: There was little correlation between SjvO2 and rSO2 in the supine position (concordance correlation coefficient=0.2819). Bland-Altman plots showed a mean bias of 8.4% with a limit of agreement of 21.6% and -4.7%. SjvO2 and rSO2 were not correlated during Trendelenburg-pneumoperitoneum condition (concordance correlation coefficient=0.3657). Bland-Altman plots showed a mean bias of 10.6% with a limit of agreement of 23.6% and -2.4%. The SjvO2-CO2 reactivity was higher than rSO2-CO2 reactivity in the supine position and Trendelenburg-pneumoperitoneum condition, respectively (0.9+/-1.1 vs. 0.4+/-1.2% mm Hg-1, p=0.04; 1.7+/-1.3 vs. 0.5+/-1.1% mm Hg-1, p<0.001). CONCLUSION: There is little correlation between SjvO2 and rSO2 in the supine position and Trendelenburg-pneumoperitoneum condition during laparoscopic surgery.

Bioequivalence of Two Erlotinib Formulations in Healthy Volunteers

BACKGROUND: Erlotinib is a tyrosine kinase inhibitor prescribed for the treatment of non-small cell lung cancer and pancreatic cancer. The aim of this study was to compare the safety and pharmacokinetics (PK) of a generic (test) formulation of erlotinib with those of a reference formulation in healthy volunteers. METHODS: A randomized, open-label, single-dose two-treatment, two-period, two-sequence, crossover study was conducted in Clinical Trials Center, Chungnam National University Hospital with 40 healthy men. Subjects orally received either one 150 mg tablet of the test or the corresponding dose of the reference, and crossover phases were separated by 14-day washout. Plasma samples were collected up to 72 hr post-dose. Plasma erlotinib concentrations were determined by liquid chromatography-tandem mass spectrometry. PK parameters were calculated by non-compartmental analysis. The safety was monitored throughout the study. RESULTS: A total of 21 cases of adverse events were reported. They are mild and relieved without an intervention. There was no serious adverse event. Median times to peak concentration of two formulations were 3.0. Means [SD] for peak concentration (Cmax) and area under the plasma concentration-time curve (AUC) of the test were 1,298 [346] microg/L and 25,318 [7,668] hrxmicrog/L. Those of the reference were 1,193 [378] microg/L and 24,853 [8,419] hrxmicrog/L. Geometric mean ratios (90% confidence intervals) for the test to the reference were 1.10 (1.02-1.18) for Cmax and 1.02 (0.97-1.09) for AUC. CONCLUSION: Two formulations were safe and well-tolerated. PK findings suggest that the test formulation is equivalent to the reference in terms of pharmacokinetics.

The Anti-calcification Effect of Dithiobispropionimidate, Carbodiimide and Ultraviolet Irradiation Cross-linking Compared to Glutaraldehyde in Rabbit Implantation Models

BACKGROUND: Glutaraldehyde (GA) is a widely used cross-linking agent for improving mechanical properties and resistance to enzymatic degradation of collagenous tissue, but it has several drawbacks such as calcification and cytotoxicity. The aim of this study was to find the alternative effective cross-linking methods to GA. MATERIALS AND METHODS: Bovine pericardium was processed with GA with ethanol+octanol and glycine detoxification, and polyethylene glycol (PG) space filler, dimethyl 3,3'-dithiobispropionimidate (DTBP), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) treatment, and the physical fixation of ultraviolet irradiation were done. The biologic material properties of variously treated pericardial tissues were assessed by biochemical, mechanical and histological tests. Treated pericardial tissues were also implanted subcutaneously or intramuscularly into the rabbit for 10 weeks to assess the xenoreactive antibody response of immunoglobulin G and M, their anti-calcification effect. RESULTS: The biochemical and mechanical properties of EDC fixed pericardial tissues were comparable to the GA fixed tissue. The cytotoxicity was lowest in space filler treated GA fixed group. In rabbit subcutaneous or intramuscular implantation models, decellularization, space filler, EDC treatment group showed significantly lower calcium content than GA only and DTBP treatment group (p<0.05, analysis of variance). The titer of anti Galalpha1-3Galbeta1-4GlcNAc-R antibodies did not change in the postimplantation serial enzyme-linked immunosorbent assay. Hematoxylin and eosin and von Kossa staining showed that decellularization, space filler, EDC, and ultraviolet treatment had less inflammatory cell infiltration and calcium deposits. CONCLUSION: The decellularization process, PG filler, and EDC treatments are good alternative cross-linking methods compared to GA only fixation and primary amine of DTBP treatment for cardiovascular xenograft preservation in terms of the collagen cross-linking stability and in vivo anti-calcification effects.

A Comparative Study on Mechanical and Biochemical Properties of Bovine Pericardium After Single or Double Crosslinking Treatment

BACKGROUND AND OBJECTIVES: Glutaraldehyde (GA) has been used as a representative method of tissue preservation in cardiovascular surgery. However, GA has showed limited durability including calcification, mechanical failure and toxicity. To overcome those unsolved problems, we analyzed the crosslinking differences of primary amines, GA and genipin in their mechanical and biochemical properties with a single or double crosslinking agent for clinical application. MATERIALS AND METHODS: Samples were divided into 3 groups; control, single crosslinking fixation and double crosslinking fixation after decellurarization using bovine pericardium. For analysis of the biochemical and mechanical properties of each crosslinking method, tensile strength, percentage strain, thermal stability, resistance to pronase, nynhydrin and cytotoxicity test were studied. RESULTS: Combined hexamethylene diamine and suberic acid in the carbodiimide hydrochloride/N-hydroxysucinimide solution (EDC/NHS) after decellurarization, tensile strength and strain percentage were not statistically significant compared to the single crosslinking treated groups (p>0.05). Tissue crosslinking stability was weak in single treatment of diphenylphosphoryl azide, suberic acid, low concentration of EDC, hexamethylene diamine and procyanidin groups, but thermal stability and resistance to the pronase and ninhydrin were markedly increased in concentrated EDC/NHS or after combined double treatment with low concentration of GA or genipin (p<0.001). CONCLUSION: Single or double crosslinking with low concentration of carbodiimide, diphenylphosphonyl azide, procyanidin, suberic acid and hexane diamine were not as effective in mechanical, biochemical, cytotoxic and crosslinking properties compared to GA or genipin fixation, but their mechanical and chemical properties were much improved when combined with low concentrations of GA or genipin in the double crosslinking process.

Comparison of loss of resistance technique between Epidrum(R) and conventional method for identifying the epidural space / 대한마취과학회지

BACKGROUND: Epidrum(R) is a recently developed, air operated, loss of resistance (LOR) device for identifying the epidural space. We investigated the usefulness of Epidrum(R) by comparing it with the conventional LOR technique for identifying the epidural space. METHODS: One hundred eight American Society of Anesthesiologists (ASA) physical status I or II patients between the ages of 17 and 68 years old and who were scheduled for elective surgery under combined spinal-epidural anesthesia were enrolled in this study. The patients were randomized into two groups: one group received epidural anesthesia by the conventional LOR technique (C group) and the second group received epidural anesthesia using Epidrum(R) (ED group). While performing epidural anesthesia, the values of variables were recorded, including the number of failures, more than 2 attempts, the incidence of dural puncture, the time needed to locate the epidural space, the distance from the skin to the epidural space and ease of performance, and the satisfaction scores. RESULTS: The ED group showed a lower failure rate, fewer cases of more than 2 attempts, a lesser time to identify the epidural space, and better ease and satisfaction scores of procedure than the C group, with statistical significance. CONCLUSIONS: Using Epidrum(R) compared to the conventional LOR technique is an easy, rapid, and reliable method for identifying the epidural space.

Histologic Characteristics and Mechanical Properties of Bovine Pericardium Treated with Decellularization and alpha-Galactosidase: A Comparative Study

BACKGROUND: Bioprostheses for cardiovascular surgery have limitations in their use following as calicification. alpha-galactosidase epitope is known as a stimulant of immune response and then shows a progressing calcification. The objective of this study was to evaluate histologic characteristics and mechanical properties of decellularization and treated with alpha-galactosidase. MATERIALS AND METHODS: Bovine pericardial tissues were allocated into three groups: fixation only with glutaraldehyde, decellularization with sodium dodesyl sulfate and decellularization plus treatment with alpha-galactosidase. We confirmed immunohistological characteristics and mechanical properties as fatigue test, permeability test, compliance test, tensile strength (strain) test and thermal stability test. RESULTS: Decellularization and elimination of alpha-gal were confirmed through immunohistologic findings. Decellularization had decreased mechanical properties compared to fixation only group in permeability (before fatigue test p=0.02, after fatigue test p=0.034), compliance (after fatigue test p=0.041), and tensile strength test (p=0.00). The group of decellularization plus treatment with alpha-galactosidase had less desirable mechanical properties than the group of decellularization in concerns of permeability (before fatigue test p=0.043) and strain test (p=0.001). CONCLUSION: Favorable decellularization and elimination of alpha-gal were obtained in this study through immunohistologic findings. However, those treatment including decellularization and elimination of alpha-gal implied the decreased mechanical properties in specific ways. We need more study to complete appropriate ioprosthesis with decellularization and elimination of alpha-gal including favorable mechanical properties too.

Changes of the Structural and Biomechanical Properties of the Bovine Pericardium after the Removal of alpha-Gal Epitopes by Decellularization and alpha-Galactosidase Treatment

BACKGROUND: Bovine pericardium is one of the most widely used materials in bioprosthetic heart valves. Immunologic responses have been implicated as potential causes of limited durability of xenogenic valves. This study aimed to determine the effectiveness of decellularization and alpha-galactosidase (alpha-gal) to remove major xenoreactive antigens from xenogenic tissues. MATERIALS AND METHODS: Recombinant Bacteroides thetaiotaomicron (B. thetaiotaomicron) alpha-gal or decellularization, or both were used to remove alpha-gal from bovine pericardium. It was confirmed by alpha-gal-bovine serum albumin-based enzyme-linked immunosorbent assay (ELISA), high-performance anion exchange chromatography, flow cytometry, 3,3'-diaminobenzidine-staining, and lectin-based ELISA. The mechanical properties of bovine pericardium after decellularization or alpha-gal treatment were investigated by tests of tensile-strength, permeability, and compliance. Collagen fiber rearrangement was also evaluated by a 20,000x transmission electron microscope (TEM). RESULTS: Recombinant B. thetaiotaomicron alpha-gal could effectively remove alpha-gal from bovine pericardium B. thetaiotaomicron (0.1 U/mL, pH 7.2) while recombinant human alpha-gal removed it recombinant human alpha-gal (10 U/mL, pH 5.0). There was no difference in the mechanical properties of fresh and recombinant alpha-gal-treated bovine pericardium. Furthermore, the TEM findings demonstrated that recombinant alpha-gal made no difference in the arrangement of collagen fiber bundles with decellularization. CONCLUSION: Recombinant B. thetaiotaomicron alpha-gal effectively removed alpha-gal from bovine pericardium with a small amount under physiological conditions compared to human recombinant alpha-gal, which may alleviate the harmful xenoreactive immunologic responses of alpha-gal. Recombinant alpha-gal treatment had no adverse effects on the mechanical properties of bovine pericardium.

Xenograft Failure of Pulmonary Valved Conduit Cross-linked with Glutaraldehyde or Not Cross-linked in a Pig to Goat Implantation Model

BACKGROUND: Biologic valved grafts are important in cardiac surgery, and although several types of graft are currently available, most commercial xenografts tend to cause early disfiguration due to intimal proliferation and calcification. We studied the graft failure patterns on non-fixed and glutaraldehyde-fixed pulmonary xenograft in vivo animal experiment. MATERIALS AND METHODS: Pulmonary valved conduits were obtained from the right ventricular outflow tract of eleven miniature pigs. The grafts were subjected to 2 different preservation methods; with or without glutaraldehyde fixation: glutaraldehyde fixation (n=7) and non-glutaraldehyde fixation (n=4). The processed explanted pulmonary valved grafts of miniature pig were then transplanted into eleven goats. Calcium quantization was achieved in all of the explanted xenograft, hemodynamic, histopathologic and radiologic evaluations were performed in the graft which the transplantation period was over 300 days (n=7). RESULTS: Grafts treated with glutaraldehyde fixation had more calcification and conduit obstruction in mid-term period. Calcium deposition also appeared much higher in the glutaraldehyde treated graft compared to the non-glutaraldehyde treated graft (p<0.05). CONCLUSION: The present study suggests that xenografts prepared using glutaraldehyde fixation alone appeared to have severe calcification compared to the findings of non-glutaraldehyde treated xenografts and to be managed with proper anticalcification treatment and novel preservation methods. This experiment gives the useful basic chemical, histologic data of xenograft failure model with calcification for further animal study.

Comparison of the trapezius squeezing test and jaw thrust as indicators for laryngeal mask airway insertion in adults / 대한마취과학회지

BACKGROUND: The purpose of this study was to compare the effectiveness of the trapezius squeezing test with that of the jaw thrust maneuver as clinical indicators of adequate conditions for laryngeal mask airway (LMA) insertion in adults under sevoflurane anesthesia. METHODS: One hundred adult patients of ASA physical status 1 or 2 undergoing minor surgical procedures were randomly allocated to the T (trapezius squeezing, n = 50) group or the J (jaw thrust, n = 50) group. The LMA was inserted immediately after the loss of response to trapezius squeezing or jaw thrust. Successful and unsuccessful attempts were recorded. An unsuccessful attempt was defined as the occurrence of coughing, gagging, gross purposeful movements, breath-holding, laryngospasm, or an SpO2 < 90% during LMA insertion. Insertion time, end-tidal sevoflurane concentration, mean arterial pressure, and heart rate were recorded. RESULTS: The incidence of successful attempts was significantly higher in the T than in the J group (48/50 vs. 36/50, respectively). CONCLUSIONS: The trapezius squeezing test is a superior indicator of an adequate condition for LMA insertion compared to the jaw thrust maneuver in adults under sevoflurane anesthesia.

Study on Genipin: A New Alternative Natural Crosslinking Agent for Fixing Heterograft Tissue

BACKGROUND: In cardiac surgery, especially in the reconstruction of vascular structures and intracardiac defects, glutaraldehyde has usually been used as the reagent for fixing porcine or bovine pericardial tissues. But the well-known problem of calcification or cytotoxicity of glutaraldehyde motivates the search for a replacement. The aim of this study is to investigate the physical, mechanical, and biochemical characteristics of bovine pericardial tissues fixed with genipin, which is known to be a less toxic and more natural fixing reagent. MATERIALS AND METHODS: Bovine pericardial tissues were fixed with different concentrations and conditions of glutaraldehyde and genipin. To determine the physical, mechanical, and biochemical differences among different concentrations and conditions, we divided the tissue into 18 groups by concentration, the addition of organic solvents, and the timing of adding the organic solvents, and compared the characteristics of each group. RESULTS: Tensile strength, physical activity, and thermal stability tests revealed that the tissues fixed with glutaraldehyde were better with regard to mechanical strength and biochemical durability. However, the difference was not significant statistically. CONCLUSION: Genipin can be used as an alternative crosslinking agent for pericardial tissue, considering given its physical, mechanical, biochemical characteristics and low cytotoxicity comparable to glutaraldehyde. However, further studies are needed on the immune reaction and the long term changes in genipin-fixed tissues in the human body.

The effect of postoperative pain on postoperative blood loss after sequential bilateral total knee arthroplasty / 대한마취과학회지

BACKGROUND: Bilateral total knee arthroplasty is generally accompanied by a significant amount of blood loss. We investigated the relationship between the intensity of pain and the amount of blood loss in the early postoperative period after bilateral total knee arthroplasty. METHODS: A prospective study was conducted on 91 patients who underwent elective sequential bilateral total knee arthroplasty for osteoarthritis. All patients received combined spinal and epidural anesthesia. Patients were divided into three groups based on their scores on the verbal numerical rating scale (VNRS) for pain at 6 hours postoperatively. The VNRS was classified as follows; mild pain (n = 34, VNRS score 0-4), moderate pain (n = 24, VNRS score 5-6), and severe pain (n = 33, VNRS score 7-10). We compared the mean arterial pressures and the amount of blood loss during the first 24 postoperative hours in the three groups. Factors influencing postoperative blood loss were analyzed. RESULTS: Postoperative mean arterial pressures and blood loss were not different among the groups. Of the factors examined, the amount of postoperative blood loss was only dependent on the amount of intraoperative blood loss (P = 0.001). CONCLUSIONS: Early postoperative pain has no effect on postoperative blood pressure and the amount of blood loss after bilateral total knee arthroplasty. For postoperative blood loss, intraoperative blood loss is the main determinant.