Phyllodulcin from the hexane fraction of Hydrangea macrophylla inhibits glucose-induced lipid accumulation and reactive oxygen species generation in Caenorhabditis elegans.

We confirmed that the hexane layer of Hydrangea macrophylla leaf extract (HLH) is rich in phyllodulcin (PD), an alternative sweetener, through high performance liquid chromatography (HPLC) analysis. To investigate in vivo activity of HLH and its PD, acute toxicity and growth rate of Caenorhabditis elegans were tested and there are no clinical abnormalities at 125-500 µg/mL of HLH. HLH decreased the total lipid and triglyceride contents dose-dependently in glucose-induced obese worms. Also, HLH increased survival rates under oxidative and thermal stress and decreased body reactive oxygen species (ROS) contents significantly. Such antioxidant properties of HLH were attributed to the enhanced activity of the antioxidant enzyme catalase. To determine whether the effect of HLH was due to PD, worms were treated with PD (concentration contained in HLH), and inhibitory effects on total lipids and ROS were observed. Our results suggest that HLH and its PD as a natural alternative sweetener can be used as materials to improve metabolic diseases.

Hepatoprotective Effect of Fresh Grape Juice Prepared by a Low-Speed Masticating Juicer in db/db Mice.

This study investigated the hepatoprotective effect of fresh grape juice prepared using a low-speed masticating (LSM) juicer or a high-speed centrifugal (HSC) juicer in mice. Six-week-old db/db mice were fed on an AIN-93G diet or a diet containing 1% freeze-dried LSM or HSC grape juice for 7 weeks. Treatment with LSM grape juice significantly decreased hepatic triglycerides, serum aspartate transaminase activities, and homeostasis model assessment for insulin resistance values, whereas HSC juice did not significantly influence these parameters. The LSM grape juice showed higher antioxidant and anti-inflammatory activities than HSC juice. The benefits of LSM grape juice are probably due to a much higher proanthocyanidin content than that of HSC juice. These results suggest that LSM grape juice can exert hepatoprotective effects in db/db mice, partly through improving insulin resistance and promoting antioxidant and inflammatory activities.

Increased Proportion of Fusion Surgery for Degenerative Lumbar Spondylolisthesis and Changes in Reoperation Rate: A Nationwide Cohort Study With a Minimum 5-Year Follow-up.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: The objectives of the present study were to examine the changes in the number of surgeries, surgical methods selected, and reoperation rates between the years 2003 and 2008. SUMMARY OF BACKGROUND DATA: The selection of the appropriate surgical method between decompression-only (D) and decompression plus fusion (DF) represents a challenging clinical dilemma in patients with degenerative lumbar spinal spondylolisthesis. DF is selected in greater than 90% of patients, mostly due to the associated low reoperation rate. However, the outcomes of D have been improved with minimally invasive decompression surgery techniques. METHODS: The Health Insurance Review and Assessment Service database was used to create cohorts of all Korean patients who underwent surgery for degenerative lumbar spinal spondylolisthesis in 2003 (2003 cohort, n = 5624) and 2008 (2008 cohort, n = 11,706). All patients were followed up for at least 5 years. Reoperation was defined as the occurrence of any type of second lumbar surgery during the follow-up period. The probabilities of reoperation were calculated using the Kaplan-Meier method. RESULTS: The number of surgeries increased 2.08-fold in 2008. Patients older than 60 years comprised 38.6% of the 2003 cohort and 52.4% of the 2008 cohort. The proportion of DF surgery was 31.13% in the 2003 cohort but 91.54% in the 2008 cohort. However, the high proportion of fusion surgery failed to reduce the reoperation probability in the 2008 cohort (8.1%) compared with that in the 2003 cohort (6.2%). The cost of DF was US$5264 and that of D was $2719 in 2008. DF decreased the reoperation probability by 1% at the cost of $421/patient in the 2008 cohort. CONCLUSION: The increased proportion of fusion surgery without improvement in reoperation probability in an aging society may be cautiously addressed in deciding future health policies. LEVEL OF EVIDENCE: 4.

Enzymatic browning reaction of apple juices prepared using a blender and a low-speed masticating household juicer.

The aim of this study was to investigate the effect of juicer type (blender or LSM household juicer) on the browning reaction of apple juice and evaluate the remaining antioxidant activity in the juice. The blender apple juice showed a darker brown color and 4.5 times higher PPO activity than LSM apple juice. This result suggested that the blender caused severer damage to plastids in cells leading to leakage of PPO into the juice than the LSM juicer. The total polyphenol and flavonoid content of LSM apple juice was approximately 2 times higher than that of blender apple juice because polyphenols and flavonoids can be used as substrates by PPO. The antioxidant activity of LSM juice was higher than that of blender juice. Together, these results suggested that the LSM juicer is superior to the blender for preparation of fresh apple juices due to the minimization of enzymatic oxidation reactions. Abbreviations: LSM: low-speed masticating; PPO: polyphenol oxidase; ABTS: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); DPPH: 2,2-diphenyl-1-picrylhydrazyl.

Increased Volume of Surgery for Lumbar Spinal Stenosis and Changes in Surgical Methods and Outcomes: A Nationwide Cohort Study with a 5-Year Follow-Up.

OBJECTIVE: Examining spine surgery patterns over time is crucial to provide insights into variations and changes in clinical decision making. Changes in the number of surgeries, surgical methods, reoperation rates, and cost-effectiveness were analyzed for all patients who underwent surgery for lumbar spinal stenosis without spondylolisthesis in 2003 (2003 cohort) and 2008 (2008 cohort). METHODS: The national health insurance database was used to create the 2003 cohort (n = 10,990) and 2008 cohort (n = 27,942). The surgical methods were classified into decompression and fusion surgery. The cumulative reoperation probability between those surgeries was calculated using the Kaplan-Meier method in the 2003 cohort and 2008 cohort. Comparison of the incremental cost-effectiveness ratios showed the additional direct cost of a 1% change in the reoperation probability. RESULTS: The surgical volume increased 2.54-fold in the 2008 cohort. The age-adjusted number of surgeries per 1 million people increased 2.6-fold (from 154 in the 2003 cohort to 399 in the 2008 cohort) in aged patients and 1.9-fold (from 154 in the 2003 cohort to 291 in the 2008 cohort) in patients 20-59 years old in the 2008 cohort. The proportion of fusion surgeries increased from 20.3% in the 2003 cohort to 37.0% in the 2008 cohort. In total, the 5-year reoperation probabilities increased from 8.1% in the 2003 cohort to 11.2% in the 2008 cohort. Fusion decreased the reoperation probability by 1% at the cost of 1,711 U.S. dollars. CONCLUSIONS: The increased numbers of spinal surgeries, fusion surgeries, and surgeries in older patients in a recent cohort were noteworthy. However, the increased surgical volume and fusion surgeries did not reduce the reoperation rate.

Increased Volume of Lumbar Surgeries for Herniated Intervertebral Disc Disease and Cost-Effectiveness Analysis: A Nationwide Cohort Study.

STUDY DESIGN: Retrospective cohort study of a nationwide database. OBJECTIVE: The primary objective was to summarize the use of surgical methods for lumbar herniated intervertebral disc disease (HIVD) at two different time periods under the national health insurance system. The secondary objective was to perform a cost-effectiveness analysis by utilizing incremental cost-effectiveness ratio (ICER). SUMMARY OF BACKGROUND DATA: The selection of surgical method for HIVD may or may not be consistent with cost effectiveness under national health insurance system, but this issue has rarely been analyzed. METHODS: The data of all patients who underwent surgeries for HIVD in 2003 (n = 17,997) and 2008 (n = 38,264) were retrieved. The surgical methods included open discectomy (OD), fusion surgery, laminectomy, and percutaneous endoscopic lumbar discectomy (PELD). The hospitals were classified as tertiary-referral hospitals (≥300 beds), medium-sized hospitals (30-300 beds), or clinics (<30 beds). ICER showed the difference in the mean total cost per 1% decrease in the reoperation probability among surgical methods. The total cost included the costs of the index surgery and the reoperation. RESULTS: In 2008, the number of surgeries increased by 2.13-fold. The number of hospitals increased by 34.75% (731 in 2003 and 985 in 2008). The proportion of medium-sized hospitals increased from 62.79% to 70.86%, but the proportion of surgeries performed at those hospitals increased from 61.31% to 85.08%. The probability of reoperation was highest after laminectomy (10.77%), followed by OD (10.50%), PELD (9.20%), and fusion surgery (7.56%). The ICERs indicated that PELD was a cost-effective surgical method. The proportion of OD increased from 71.21% to 84.12%, but that of PELD decreased from 16.68% to 4.57%. CONCLUSION: The choice of surgical method might not always be consistent with cost-effectiveness strategies, and a high proportion of medium-sized hospitals may be responsible for this change. LEVEL OF EVIDENCE: 4.

Antioxidant activities of fresh grape juices prepared using various household processing methods.

The purpose of this study was to evaluate and compare the antioxidant activities, and their contents, in grape juices prepared by various household juicers, and grape flesh (GF). The grape juices were prepared using a low-speed masticating (LSM) juicer, a high-speed centrifugal (HSC) juicer, and a blender (BLD). The total polyphenol, total flavonoid, total monomeric anthocyanin, and vitamin C contents were highest in the LSM grape juice, and decreased in the order: LSM > BLD > HSC > GF. The antioxidant activities such as DPPH radical scavenging activity, and SOD-like activity were significantly higher in the LSM juice than in other juices and grape flesh. The antioxidant activities and the quality of grape juices were significantly affected by the household juicing method used, and an LSM juicer is strongly recommended for making healthy grape juice, rich in antioxidants.

Imbalance in Cardiovascular Surgery Medical Service Use Between Regions.

BACKGROUND: This study uses the relevance index to understand the condition of regional medical service use for cardiovascular surgery and to identify the medical service use imbalance between regions. METHODS: This study calculated the relevance index of 16 metropolitan cities and provinces using resident registration address data from the Ministry of Government Administration and Home Affairs and the 2010-2014 health insurance, medical care assistance, and medical benefits claims data from the Health Insurance Review and Assessment Service. We identified developments over the 5-year time period and analyzed the level of regional imbalance regarding cardiovascular surgery through the relative comparison of relevance indexes between cardiovascular and other types of surgery. RESULTS: The relevance index was high in large cities such as Seoul, Daegu, and Gwangju, but low in regions that were geographically far from the capital area, such as the Gangwon and Jeju areas. Relevance indexes also fell as the years passed. Cardiovascular surgery has a relatively low relevance index compared to key types of surgery of other fields, such as neurosurgery and colorectal surgery. CONCLUSION: This study identified medical service use imbalance between regions for cardiovascular surgery. Results of this study demonstrate the need for political intervention to enhance the accessibility of necessary special treatment, such as cardiovascular surgery.

The Association Between Treatment Frequency and Treatment Outcome for Cardiovascular Surgeries.

BACKGROUND: This study analyzed the association between the volume of heart surgeries and treatment outcomes for hospitals in the last five years. METHODS: Hospitals that perform heart surgeries were chosen throughout Korea as subjects using from the Health Insurance Review and Assessment Service. The treatment outcome of the heart surgeries was defined as the mortality within 30 postoperative days, while the annual volume of the surgeries was categorized. Logistic regression was used as the statistical analysis method, and the impacts of the variables on the heart surgery treatment outcomes were then analyzed. RESULTS: The chance of death of patients who received surgery in a hospital that performed 50 or more surgeries annually was noticeably lower than patients receiving operations from hospitals that performed fewer than 50 surgeries annually, indicating that the chance of death decreases as the annual volume of heart surgeries in the hospital increases. In particular, the mortality rate in hospitals that performed more than 200 surgeries annually was less than half of that in hospitals that performed 49 or fewer surgeries annually. CONCLUSION: These results indicate that accumulation of a certain level of heart surgery experience is critical in improving or maintaining the quality of heart surgeries. In order to improve the treatment outcomes of small hospitals, a support policy must be implemented that allows for cooperation with experienced professionals.

Development of Models for Regional Cardiac Surgery Centers.

BACKGROUND: This study aimed to develop the models for regional cardiac surgery centers, which take regional characteristics into consideration, as a policy measure that could alleviate the concentration of cardiac surgery in the metropolitan area and enhance the accessibility for patients who reside in the regions. METHODS: To develop the models and set standards for the necessary personnel and facilities for the initial management plan, we held workshops, debates, and conference meetings with various experts. RESULTS: After partitioning the plan into two parts (the operational autonomy and the functional comprehensiveness), three models were developed: the 'independent regional cardiac surgery center' model, the 'satellite cardiac surgery center within hospitals' model, and the 'extended cardiac surgery department within hospitals' model. Proposals on personnel and facility management for each of the models were also presented. A regional cardiac surgery center model that could be applied to each treatment area was proposed, which was developed based on the anticipated demand for cardiac surgery. The independent model or the satellite model was proposed for Chungcheong, Jeolla, North Gyeongsang, and South Gyeongsang area, where more than 500 cardiac surgeries are performed annually. The extended model was proposed as most effective for the Gangwon and Jeju area, where more than 200 cardiac surgeries are performed annually. CONCLUSION: The operation of regional cardiac surgery centers with high caliber professionals and quality resources such as optimal equipment and facility size, should enhance regional healthcare accessibility and the quality of cardiac surgery in South Korea.

Projections of Demand for Cardiovascular Surgery and Supply of Surgeons.

BACKGROUND: While demand for cardiovascular surgery is expected to increase gradually along with the rapid increase in cardiovascular diseases with respect to the aging population, the supply of thoracic and cardiovascular surgeons has been continuously decreasing over the past 10 years. Consequently, this study aims to achieve guidance in establishing health care policy by analyzing the supply and demand for cardiovascular surgeries in the medical service area of Korea. METHODS: After investigating the actual number of cardiovascular surgeries performed using the National Health Insurance claim data of the Health Insurance Review and Assessment Service, as well as drawing from national statistics concerning the elderly population aged 65 and over, this study estimated the number of future cardiovascular surgeries by using a cell-based model. To be able to analyze the supply and demand of surgeons, the recent status of new surgeons specializing in thoracic and cardiovascular surgeries and the ratio of their subspecialties in cardiovascular surgeries were investigated. Then, while taking three different scenarios into account, the number of cardiovascular surgeons expected be working in 5-year periods was projected. RESULTS: The number of cardiovascular surgeries, which was recorded at 10,581 cases in 2014, is predicted to increase consistently to reach a demand of 15,501 cases in 2040-an increase of 46.5%. There was a total of 245 cardiovascular surgeons at work in 2014. Looking at 5 year spans in the future, the number of surgeons expected to be supplied in 2040 is 184, to retire is 249, and expected to be working is 309-an increase of -24.9%, 1.6%, and 26.1%, respectively compared to those in 2014. This forecasts a demand-supply imbalance in every scenario. CONCLUSION: Cardiovascular surgeons are the most central resource in the medical service of highly specialized cardiovascular surgeries, and fostering the surgeons requires much time, effort, and resources; therefore, by analyzing the various factors affecting the supply of cardiovascular surgeons, an active intervention of policies can be prescribed for the areas that have failed to meet the appropriate market distributions.

The Selection of Open or Percutaneous Endoscopic Lumbar Discectomy According to an Age Cut-off Point: Nationwide Cohort Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To provide an age cut-off of percutaneous endoscopic lumbar discectomy (PELD) for optimal reoperation rate with nationwide population-based data. SUMMARY OF BACKGROUND DATA: Open discectomy is the standard operation for lumbar herniated intervertebral disk disease (HIVD). PELD has shown noninferior outcome to open discectomy and there is increasing interest with regard to PELD. However, PELD may not be a suitable option for all age groups. METHODS: We selected 15,817 patients who underwent open discectomy (n = 12,816) or PELD (n = 3001) in 2003 from the Korean Health Insurance Review & Assessment Service (HIRA) database. All patients in the cohort were followed until December 31, 2008, and the minimum follow-up period was 5 years. A time-to-event survival analysis was conducted. The primary endpoint was any type of second lumbar spine surgery during the follow-up period. Minimum P-value approach and a 2-fold cross-validation approach were utilized to determine an age cut-off point. RESULTS: The optimal age cut-off point was determined as 57 years. PELD for older patients (≥57 years) had a higher reoperation risk during the postoperative 3.4 years (hazard ratio [HR] at 1 yr, 1.75; 2 yr, 1.57; and 3 yr, 1.41). However, the reoperation risk was not higher after PELD for patients younger than 57 years, from 1.9 years, than open discectomy (HR at 2 yr, 0.86; 3 yr, 0.78; 4 yr, 0.70; and 5 yr, 0.63). CONCLUSION: In the present study, we showed that an age cut-off point of PELD for optimal reoperation rate may be 57 years, based on nationwide population-based data. The reoperation rate does not seem to be higher for patients younger than 57 years after PELD than after open discectomy; however, PELD for older patients should be applied after careful consideration. LEVEL OF EVIDENCE: 3.

Biosynthesis of glucosyl glycerol, a compatible solute, using intermolecular transglycosylation activity of amylosucrase from Methylobacillus flagellatus KT.

A putative α-amylase gene (accession number, CP000284) of Methylobacillus flagellatus KT ATCC51484 was cloned in Escherichia coli, and its gene product was expressed and characterized. The purified recombinant enzyme (MFAS) displayed a typical amylosucrase (ASase) activity by the demonstration of multiple activities of hydrolysis, isomerization, and polymerization although it was designated as an α-amylase. The optimal reaction temperature and pH for the sucrose hydrolysis activity of MFAS were determined to be 45 °C and pH 8.5, respectively. MFAS has relatively high thermostable characteristics compared with other ASases, as demonstrated by a half-life of 19.3 min at 50 °C. MFAS also showed polymerization activity using sucrose as a sole substrate. Glycerol was transglycosylated by the intermolecular transglycosylation activity of MFAS. Two major products were observed by thin-layer chromatography and isolated by paper chromatography and recycling HPLC. Using (1)H and (13)C NMR, their chemical structures were determined to be (2S)-1-O-α-D-glucosyl-glycerol or (2R)-1-O-α-D-glucosyl-glycerol and 2-O-α-D-glucosyl-glycerol, in which a glucose molecule is linked to glycerol via an α-glycosidic linkage.

Diagnostic radiation exposure of injury patients in the emergency department: a cross-sectional large scaled study.

In contrast to patients with underlying cancer or chronic disease, injury patients are relatively young, and can be expected to live their natural lifespan if injuries are appropriately treated. Multiple and repeated diagnostic scans might be performed in these patients during admission. Nevertheless, radiation exposure in injury patients has been overlooked and underestimated because of the emergent nature of such situations. Therefore, we tried to assess the cumulative effective dose (cED) of injury patients in the emergency department. We included patients who visited the emergency department (ED) of a single tertiary hospital due to injury between February 2010 and February 2011. The cED for each patient was calculated and compared across age, sex and injury mechanism. A total of 11,676 visits (mean age: 28.0 years, M:F = 6,677:4,999) were identified. Although CT consisted of only 7.8% of total radiologic examinations (n=78,025), it accounted for 87.1% of the total cED. The mean cED per visit was 2.6 mSv. A significant difference in the cED among injury mechanisms was seen (p<0.001) and patients with traffic accidents and fall down injuries showed relatively high cED values. Hence, to reduce the cED of injury patients, an age-, sex- and injury mechanism-specific dose reduction strategy should be considered.

Biosynthesis of (+)-catechin glycosides using recombinant amylosucrase from Deinococcus geothermalis DSM 11300.

Amylosucrase (ASase, EC 2.4.1.4) is a glucosyltransferase that hydrolyzes sucrose into glucose and fructose and produces amylose-like glucan polymers from the released glucose. (+)-Catechin is a plant polyphenolic metabolite having skin-whitening and antioxidant activities. In this study, the ASase gene from Deinococcus geothermalis (dgas) was expressed in Escherichia coli, while the recombinant DGAS enzyme was purified using a glutathione S-transferase fusion system. The (+)-catechin glycoside derivatives were synthesized from (+)-catechin using DGAS transglycosylation activity. We confirmed the presence of two major transglycosylation products using TLC. The (+)-catechin transglycosylation products were isolated using silica gel open column chromatography and recycling-HPLC. Two (+)-catechin major transfer products were determined through (1)H and (13)C NMR to be (+)-catechin-3'-O-α-D-glucopyranoside with a glucose molecule linked to (+)-catechin and (+)-catechin-3'-O-α-D-maltoside with a maltose linked to (+)-catechin. The presence of (+)-catechin maltooligosaccharides in the DGAS reaction was also confirmed via recycling-HPLC and enzymatic analysis. The effects of various reaction conditions (temperature, enzyme concentration, and molar ratio of acceptor and donor) on the yield and type of (+)-catechin glycosides were investigated.

Structural features of the Nostoc punctiforme debranching enzyme reveal the basis of its mechanism and substrate specificity.

The debranching enzyme Nostoc punctiforme debranching enzyme (NPDE) from the cyanobacterium Nostoc punctiforme (PCC73102) hydrolyzes the alpha-1,6 glycosidic linkages of malto-oligosaccharides. Despite its high homology to cyclodextrin/pullulan (CD/PUL)-hydrolyzing enzymes from glycosyl hydrolase 13 family (GH-13), NPDE exhibits a unique catalytic preference for longer malto-oligosaccharides (>G8), performing hydrolysis without the transgylcosylation or CD-hydrolyzing activities of other GH-13 enzymes. To investigate the molecular basis for the property of NPDE, we determined the structure of NPDE at 2.37-A resolution. NPDE lacks the typical N-terminal domain of other CD/PUL-hydrolyzing enzymes and forms an elongated dimer in a head-to-head configuration. The unique orientation of residues 25-55 in NPDE yields an extended substrate binding groove from the catalytic center to the dimeric interface. The substrate binding groove with a lengthy cavity beyond the -1 subsite exhibits a suitable architecture for binding longer malto-oligosaccharides (>G8). These structural results may provide a molecular basis for the substrate specificity and catalytic function of this cyanobacterial enzyme, distinguishing it from the classical neopullulanases and CD/PUL-hydrolyzing enzymes.

Antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes mellitus.

Hyperglycemia in the diabetic state increases oxidative stress and antioxidant therapy can be strongly correlated with decreased risks for diabetic complications. The purpose of this study is to determine antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes. The antioxidant activity of garlic and aged black garlic was measured as the activity in scavenging free radicals by the trolox equivalent antioxidant capacity (TEAC) assay. Three week-old db/db mice were fed AIN-93G diet or diet containing 5% freeze-dried garlic or aged black garlic for 7 weeks after 1 week of adaptation. Hepatic levels of lipid peroxides and activities of antioxidant enzymes were measured. TEAC values of garlic and aged black garlic were 13.3 +/- 0.5 and 59.2 +/- 0.8 micromol/g wet weight, respectively. Consumption of aged black garlic significantly decreased hepatic thiobarbituric acid reactive substances (TBARS) level compared with the garlic group which showed lower TBARS level than control group (p<0.05). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of garlic and aged black garlic group were significantly elevated compared to the control group. Catalase (CAT) activity of aged black garlic group was increased compared with the control group. These results show that aged black garlic exerts stronger antioxidant activity than garlic in vitro and in vivo, suggesting garlic and aged black garlic, to a greater extent, could be useful in preventing diabetic complications.

Characterization of Bacillus polyfermenticus KJS-2 as a probiotic.

The identification and characterization of Bacillus polyfermenticus KJS-2 (B. polyfermenticus KJS-2) was conducted using TEM, an API 50CHB kit, 16S rDNA sequencing, a phylogenetic tree, and catalase and oxidase testing. The conversion rate of glucose to lactic acid by B. polyfermenticus KJS-2 was found to be 60.71+/-4.9%. In addition, treatment of B. polyfermenticus KJS-2 with artificial gastric juice (pH 2.0) and bile acid (pH 6.5) for 4 h resulted in a final viability of 140+/-7.9% and 108+/-3.5%, respectively. Finally, the results of adhesion experiments using Caco-2 cells revealed that the adherence of B. polyfermenticus KJS-2 to Caco-2 cells was approximately 65+/-0.6%.

Role of maltogenic amylase and pullulanase in maltodextrin and glycogen metabolism of Bacillus subtilis 168.

The physiological functions of two amylolytic enzymes, a maltogenic amylase (MAase) encoded by yvdF and a debranching enzyme (pullulanase) encoded by amyX, in the carbohydrate metabolism of Bacillus subtilis 168 were investigated using yvdF, amyX, and yvdF amyX mutant strains. An immunolocalization study revealed that YvdF was distributed on both sides of the cytoplasmic membrane and in the periplasm during vegetative growth but in the cytoplasm of prespores. Small carbohydrates such as maltoheptaose and beta-cyclodextrin (beta-CD) taken up by wild-type B. subtilis cells via two distinct transporters, the Mdx and Cyc ABC transporters, respectively, were hydrolyzed immediately to form smaller or linear maltodextrins. On the other hand, the yvdF mutant exhibited limited degradation of the substrates, indicating that, in the wild type, maltodextrins and beta-CD were hydrolyzed by MAase while being taken up by the bacterium. With glycogen and branched beta-CDs as substrates, pullulanase showed high-level specificity for the hydrolysis of the outer side chains of glycogen with three to five glucosyl residues. To investigate the roles of MAase and pullulanase in glycogen utilization, the following glycogen-overproducing strains were constructed: a glg mutant with a wild-type background, yvdF glg and amyX glg mutants, and a glg mutant with a double mutant (DM) background. The amyX glg and glg DM strains accumulated significantly larger amounts of glycogen than the glg mutant, while the yvdF glg strain accumulated an intermediate amount. Glycogen samples from the amyX glg and glg DM strains exhibited average molecular masses two and three times larger, respectively, than that of glycogen from the glg mutant. The results suggested that glycogen breakdown may be a sequential process that involves pullulanase and MAase, whereby pullulanase hydrolyzes the alpha-1,6-glycosidic linkage at the branch point to release a linear maltooligosaccharide that is then hydrolyzed into maltose and maltotriose by MAase.

Absorption, distribution, metabolism, and excretion of decursin and decursinol angelate from Angelica gigas Nakai.

The pharmacokinetics of decursin and decursinol angelate (D/DA) was investigated in male SD rats following oral and intravenous administration. D/DA and metabolites obtained from in vitro samples were evaluated by LC/MS. The level of D/DA and metabolized decursinol in the blood following oral and intravenous administration declined according to first-order kinetics, with T1/2 values of 56.67, 58.01 and 57.22 h, respectively, being observed after administration of a dose of 2 mg/kg body weight. The large intestine was the major site of disposition following oral administration. These data indicate that D/DA is rapidly absorbed from the gastrointestinal tract. In in vitro experiment utilizing liver microsomal protein, the major metabolic reaction of D/DA occurred to change decursinol. The cumulative biliary, urinary, and fecal excretion of D/DA in bile duct-cannulated rats was 36.10+/-2.9, 25.35+/-3.8, and 34.20+/-3.2%, respectively, at 72 h after administration. These results indicate that the absorption of D/DA is almost complete, and that its metabolites are primarily excreted into feces through the bile. These results indicate that D/DA is subject to enterohepatic circulation.