Therapeutic Potency of NO Loaded into Anticancer Copper Metal-Organic Framework through Nonclassical Hydrogen Bonding

Metal-organic frameworks (MOFs) are potential exogenous scaffolds for therapeutic nitric oxide (NO) delivery because they can store drug or bioactive gas molecules within pores or on active metal sites. Herein, we employed a Cu-MOF coordinated with glutarate (glu) and 1,2-bis(4-pyridyl)ethane (bpa) to obtain NO-loaded Cu-MOF (NO⊂Cu-MOF). NO loading transformed the space group of Cu-MOF from monoclinic C2/c to triclinic P-1 through nonclassical hydrogen bonding with glu and bpa. Cu-MOF showed good stability in deionized water and phosphate-buffered saline. NO⊂Cu-MOF released up to 1.10 μmol mg-1 NO over 14.6 h at 37 °C, which is suitable for therapeutic applications. NO⊂Cu-MOF showed moderate biocompatibility with L-929 cells and significant anticancer activity against HeLa cells, suggesting an apoptosis-mediated cell death mechanism. These insights into NO bonding modes with Cu-MOF that enable controlled NO release can inspire the design of functional MOFs as hybrid NO donors for drug delivery.

Controllable Nitric Oxide Storage and Release in Cu-BTC: Crystallographic Insights and Bioactivity

Crystalline metal–organic frameworks (MOFs) are extensively used in areas such as gas storage and small-molecule drug delivery. Although Cu-BTC (1, MOF-199, BTC: benzene-1,3,5-tricarboxylate) has versatile applications, its NO storage and release characteristics are not amenable to therapeutic usage. In this work, micro-sized Cu-BTC was prepared solvothermally and then processed by ball-milling to prepare nano-sized Cu-BTC (2). The NO storage and release properties of the micro- and nano-sized Cu-BTC MOFs were morphology dependent. Control of the hydration degree and morphology of the NO delivery vehicle improved the NO release characteristics significantly. In particular, the nano-sized NO-loaded Cu-BTC (NO⊂nano-Cu-BTC, 4) released NO at 1.81 µmol·mg⁻¹ in 1.2 h in PBS, which meets the requirements for clinical usage. The solid-state structural formula of NO⊂Cu-BTC was successfully determined to be [CuC₆H₂O₅]·(NO)_0.167 through single-crystal X-ray diffraction, suggesting no structural changes in Cu-BTC upon the intercalation of 0.167 equivalents of NO within the pores of Cu-BTC after NO loading. The structure of Cu-BTC was also stably maintained after NO release. NO⊂Cu-BTC exhibited significant antibacterial activity against six bacterial strains, including Gram-negative and positive bacteria. NO⊂Cu-BTC could be utilized as a hybrid NO donor to explore the synergistic effects of the known antibacterial properties of Cu-BTC.

Bleeding risk in patients with atrial fibrillation treated with combined anti-platelet and NOAC therapy

Background

The combined use of antiplatelet agents (APT) and non-vitamin K antagonist oral anticoagulants (NOACs) in patient with atrial fibrillation (AF) is commonly encountered in clinical practice. The purpose of this study was to compare the clinical outcomes between combination therapy (NOAC and APT) and monotherapy (NOAC only).

Methods and results

We analyzed patients who were prescribed NOACs between January 2012 and December 2016. The primary outcome was major or any bleeding events and the secondary outcomes were stroke/systemic embolism (SE) and major adverse cardiac events (MACE). Of 1,068 participants, there were 264 (24.7%) patients in the combination group.

The prevalence of diabetes (p=0.017) and history of stroke and transient ischemic attacks (p<0.001) was higher in the combination group than in the monotherapy group. During the mean 14.6±9.8 months of follow-up, the incidence of any bleeding was significantly higher in the combination group than in the monotherapy group (p<0.001). Major bleeding, stroke/SE, and MACE between the two groups were similar. The rate of under-dosage NOACs prescriptions was higher in the combination group than in the monotherapy group (p=0.024).

Conclusions

The combination therapy had higher incidences of any bleeding events compared to the monotherapy. However, there was no difference in stroke/SE and MACE.

The bleeding risk in patients taking the combination of NOACs and APT should be carefully evaluated.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Primary and secondary outcomes

The volume of left atrium measured by multi-detector computed tomography can predict of long term outcome in catheter ablation of atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

This study aimed to identify the volume left atrium (LA) and left atrial appendage (LAA) calculated by multidetector computed tomography (MDCT) is related to the long term out come of radiofrequency catheter ablation (RFCA) for atrial fibrillation(AF).

Methods

We analyzed data from 99 consecutive patients who referred for RFCA due to drug-refractory symptomatic AF (age 56 ± 10 years; 74% men; 64% paroxysmal AF). Prior to the procedure, all patients underwent ECG-gated 128 channels MDCT scan for assessment for pulmonary vein  anatomy, LA and LAA volume estimation, and electro-anatomical mapping integration. 

Results

The volume of LA and LAA calculated by CT was 142.6 ± 32.2 mL and 14.7 ± 6.0 mL, respectively. LA volume was smaller in paroxysmal AF(PAF) than persistent AF(PeAF) (133.9 ± 29.3 mL vs. 158.0 ± 31.4 mL, p < 0.0001) but  LAA volume was not significantly different between PAF and PeAF(13.9 ± 5.0 mL vs. 16.3 ± 7.3 mL, p = 0.09). Patients were classified into 2 groups by the LA volume of 160mL; group 1  (LA volume < 160mL,n = 73) and group 2 (LA volume ≥160mL, n = 26). After a mean follow up 12.6 ± 5.3 months, 78.8% of the patients maintained sinus rhythm after the index ablation. AF free survival was significantly greater in group  1 than group 2 (84.9% vs. 61.5% p = 0.017). No relationship was found between LAA volume and the outcome of RFCA. Multivariate analysis showed that the LA volume >160mL was an independent predictor of arrhythmia-free after ablation (Hazard ration 2.55, 95% confidential interval 1.02-6.35, p = 0.045)

Conclusion

Higher LA volume is independent risk factor for AF recurrence after RFCA but not LAA volume. The LA volume quickly assessed by MDCT could be a good predictor of long term recurrence after AF ablation.

Multidrug-resistant tuberculosis in South Korea: a retrospective analysis of national registry data in 2011-2015

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) poses a threat to public health as a result of high treatment costs and unsatisfactory outcomes.OBJECTIVE: To elucidate trend, demographic and clinical characteristics and treatment outcomes of patients with MDR-TB between 2011 and 2015 in South Korea.METHOD: Data of patients with MDR-TB diagnosed between 1 January 2011 and 31 December 2015 were retrieved from the nationwide Internet-based TB notification system and analysed retrospectively.RESULTS: During the study period, 5192 MDR-TB patients were notified. We identified an increasing number of MDR-TB patients among foreign populations (from 1.3% to 7.7%), decreasing resistance rates to other anti-TB drugs (e.g., resistance to pyrazinamide, from 40.9% to 28.2%), a decreasing interval from treatment initiation to negative conversion of sputum culture (from 165.7 to 103.7 days) and shortening of treatment duration (719.7 to 613.2 days). However, treatment success rates did not change, and had an average of 65.7%.CONCLUSION: Despite decreasing resistance rates to other drugs and faster treatment responses, treatment outcomes did not improve during the study period. Strict management of MDR-TB patients on treatment should be adopted to improve treatment outcomes.

Impacts of pre-rigor salting with KCl on technological properties of ground chicken breast

The objective of this study was to determine the impact of pre-rigor salting using KCl on the technological properties of ground chicken breast. Chicken breast muscle (M. pectoralis major and minor) was hot-debonded and salted with 2% NaCl (w/w), 1% NaCl+1% KCl mixture, or 2% KCl, respectively, within 30 min after slaughter. Post-rigor salting treatment was prepared with 2% NaCl at 24 h postmortem. All pre-rigor salting treatments showed higher ultimate pH, protein solubility, and final yield than post-rigor salting treatment (P < 0.05). However, the positive effects of pre-rigor salting on chicken breast differed by salt type. Pre-rigor salting with KCl resulted in higher ultimate pH and R-values of chicken breast than pre-rigor salting with NaCl (P < 0.05). Despite the high ultimate pH, pre-rigor salting with KCl resulted in lower protein solubility, final yield, and hardness of chicken breast than pre-rigor salting with NaCl (P < 0.05). These results indicate that pre-rigor salting with KCl could contribute to the maintenance of relatively excellent technological properties of pre-rigor chicken breasts compared to post-rigor salted chicken breast. However, this current study also suggests that the impact of KCl on technological properties in pre-rigor chicken breast, such as water-holding capacity, protein solubility, and texture, could be less effective than pre-rigor salting with NaCl at an identical percentage concentration.

Potential Protective Effect of Nitric Oxide-Releasing Nanofibers in Hypoxia/Reoxygenation-Induced Cardiomyocyte Injury

Nitric oxide (NO) is involved in several physiological processes including vasodilation, angiogenesis, immune response, and wound healing, as well as preventing ischemia/reperfusion injury in many organs such as the heart, liver, lungs, and kidneys. Recently, various NO delivery systems such as nanoparticles, nanorods, and nanofibers have been widely studied as potential therapeutic agents. In particular, NO-releasing nanofibers have been attracting much attention for various medicinal applications including regenerative medicine, wound dressings, and coatings for implantable medical devices, due to their flexible and open architectures. In this study, we prepared biocompatible NO-releasing nanofibers by electrospinning using mixed solutions of polymers and methylaminopropyltrimethoxysilane (MAP3), which was modified with N-diazeniumdiolate as an NO donor. In addition, we evaluated their protective effects on hypoxia/reoxygenation (HR) injury in H9c2 cells. The total NO amount released from the resulting MAP3 nanofibers was 1.26 µmol ·mg^-1. From the cytotoxicity evaluation of various weights of NO-releasing nanofibers (0 to 2 mg), we selected 1 mg NO-releasing nanofibers for the subsequent experiments. Pre-treatment with NO-releasing nanofibers before hypoxia induction could provide a cytoprotective effect against HR-induced injury in H9c2 cells. The nanofibers could also effectively inhibit the generation of hydrogen peroxide, which was one major contributor to oxidative damage, as well as 8-hydroxyl-2-deoxyguanosine level as an indicator of oxidative DNA damage. In addition, pre-treatment with NO-releasing nano-fibers in a wound model showed wound healing effects similar to those of normal cells. As a result, N-diazeniumdiolate-modified MAP3 nanofibers might protect H9c2 cells from DNA damage by inhibiting the generation of oxidative stress in HR injury. Therefore, we expect that NO-releasing nanofibers could be utilized as a therapeutic strategy for protecting cardiomyocytes from HR injury.

Electrodeposition of SnO2 on FTO and its Application in Planar Heterojunction Perovskite Solar Cells as an Electron Transport Layer

We report the performance of perovskite solar cells (PSCs) with an electron transport layer (ETL) consisting of a SnO₂ thin film obtained by electrochemical deposition. The surface morphology and thickness of the electrodeposited SnO₂ films were closely related to electrochemical process conditions, i.e., the applied voltage, bath temperature, and deposition time. We investigated the performance of PSCs based on the SnO₂ films. Remarkably, the experimental factors that are closely associated with the photovoltaic performance were strongly affected by the SnO₂ ETLs. Finally, to enhance the photovoltaic performance, the surfaces of the SnO₂ films were modified slightly by TiCl₄ hydrolysis. This process improves charge extraction and suppresses charge recombination.

A Study on CYP2C19 and CYP2D6 Polymorphic Effects on Pharmacokinetics and Pharmacodynamics of Amitriptyline in Healthy Koreans

We performed a double-blinded, genotype-based stratification study to explore the pharmacokinetics and pharmacodynamics of amitriptyline according to CYP2C19 and CYP2D6 genotype in Korean subjects. Twenty-four healthy adults were grouped by genotype of CYP2C19 and CYP2D6. After a single dose of 25 mg of amitriptyline, blood samples were collected and anticholinergic effects were measured. The extent of N-demethylation of amitriptyline significantly decreased in subjects carrying two nonfunctional alleles of CYP2C19. The extent of hydroxylation of amitriptyline or nortriptyline was significantly reduced in subjects carrying two CYP2D6 decreased functional alleles compared with those with no or one decreased functional allele. The overall metabolic pathway of amitriptyline was more likely to be dominated by CYP2C19 than CYP2D6. The gene variations of CYP2C19 and CYP2D6 did not change the pharmacodynamic effect. The findings of this study will provide useful information on individualized drug treatment with amitriptyline considering both CYP2D6 and CYP2C19 gene variations.

Robust MR assessment of cerebral blood volume and mean vessel size using SPION-enhanced ultrashort echo acquisition

Intravascular superparamagnetic iron oxide nanoparticles (SPION)-enhanced MR transverse relaxation rates (∆R2(⁎) and ∆R2) are widely used to investigate in vivo vascular parameters, such as the cerebral blood volume (CBV), microvascular volume (MVV), and mean vessel size index (mVSI, ∆R2(⁎)/∆R2). Although highly efficient, regional comparison of vascular parameters acquired using gradient-echo based ∆R2(⁎) is hampered by its high sensitivity to magnetic field perturbations arising from air-tissue interfaces and large vessels. To minimize such demerits, we took advantage of the dual contrast property of SPION and both theoretically and experimentally verified the direct benefit of replacing gradient-echo based ∆R2(⁎) measurement with ultra-short echo time (UTE)-based ∆R1 contrast to generate the robust CBV and mVSI maps. The UTE acquisition minimized the local measurement errors from susceptibility perturbations and enabled dose-independent CBV measurement using the vessel/tissue ∆R1 ratio, while independent spin-echo acquisition enabled simultaneous ∆R2 measurement and mVSI calculation of the cortex, cerebellum, and olfactory bulb, which are animal brain regions typified by significant susceptibility-associated measurement errors.

Ultrafast 3D spin-echo acquisition improves Gadolinium-enhanced MRI signal contrast enhancement

Long scan times of 3D volumetric MR acquisitions usually necessitate ultrafast in vivo gradient-echo acquisitions, which are intrinsically susceptible to magnetic field inhomogeneities. This is especially problematic for contrast-enhanced (CE)-MRI applications, where non-negligible T₂* effect of contrast agent deteriorates the positive signal contrast and limits the available range of MR acquisition parameters and injection doses. To overcome these shortcomings without degrading temporal resolution, ultrafast spin-echo acquisitions were implemented. Specifically, a multiplicative acceleration factor from multiple spin echoes (×32) and compressed sensing (CS) sampling (×8) allowed highly-accelerated 3D Multiple-Modulation-Multiple-Echo (MMME) acquisition. At the same time, the CE-MRI of kidney with Gd-DOTA showed significantly improved signal enhancement for CS-MMME acquisitions (×7) over that of corresponding FLASH acquisitions (×2). Increased positive contrast enhancement and highly accelerated acquisition of extended volume with reduced RF irradiations will be beneficial for oncological and nephrological applications, in which the accurate in vivo 3D quantification of contrast agent concentration is necessary with high temporal resolution.

The comparison of femoral and radial arterial blood pressures during pediatric liver transplantation

BACKGROUND

Orthotopic liver transplantation (OLT) is frequently associated with dramatic hemodynamic changes; thus, it is critical to accurately monitor blood pressure. Although comparisons between femoral arterial blood pressure (FABP) and radial arterial blood pressure (RABP) have been reported in adult liver recipients, we compared FABP with RABP in pediatric recipients.

METHODS

Thirty-five pediatric liver recipients younger than 13 years of age were included in this prospective, observational study. We measured simultaneous FABP and RABP in the femoral and radial arteries at nine time points during the procedure, including: baseline (after anesthetic induction); 1 hour thereafter; 30 minutes after the beginning of the anhepatic period as well as 0, 1, 3, 5, 15, and 60 minutes after graft reperfusion.

RESULTS

Of the 35 pediatric liver recipients, 2 infants and 1 13-month-old child were excluded from the analysis because of radial arterial catheter malfunction. The remaining 32 patients including 16 infants and 16 children all showed significantly higher systolic and mean FABP than RABP during most stages of pediatric OLT. Overall diastolic FABP measurements were similar to diastolic RABP throughout the study.

CONCLUSIONS

Systolic and mean FABP were significantly higher than RABP during most stages of pediatric OLT. Radial arterial catheter malfunctions were not uncommon during pediatric OLT. Our results indicated that it is useful to cannulate the femoral artery to accurately and reliably measure arterial blood pressure to detect hemodynamic instability during pediatric OLT.

The effects of prolonged inspiratory time during one-lung ventilation: a randomised controlled trial

We evaluated the effects of a prolonged inspiratory time on gas exchange in subjects undergoing one-lung ventilation for thoracic surgery. One hundred patients were randomly assigned to Group I:E = 1:2 or Group I:E = 1:1. Arterial blood gas analysis and respiratory mechanics measurements were performed 10 min after anaesthesia induction, 30 and 60 min after initiation of one-lung ventilation, and 15 min after restoration of conventional two-lung ventilation. The mean (SD) ratio of the partial pressure of arterial oxygen to fraction of inspired oxygen after 60 min of one-lung ventilation was significantly lower in Group I:E = 1:2 compared with Group I:E = 1:1 (27.7 (13.2) kPa vs 35.2 (22.1) kPa, respectively, p = 0.043). Mean (SD) physiological dead space-to-tidal volume ratio after 60 min of one-lung ventilation was significantly higher in Group I:E = 1:2 compared with Group I:E = 1:1 (0.46 (0.04) vs 0.43 (0.04), respectively, p = 0.008). Median (IQR [range]) peak inspiratory pressure was higher in Group I:E = 1:2 compared with Group I:E = 1:1 after 60 min of one-lung ventilation (23 (22-25 [18-29]) cmH2O vs 20 (18-21 [16-27]) cmH2O, respectively, p < 0.001) and median (IQR [range]) mean airway pressure was lower in Group I:E = 1:2 compared with Group I:E = 1:1 (10 (8-11 [5-15]) cmH2O vs 11 (10-13 [5-16]) cmH2O, respectively, p < 0.001). We conclude that, compared with an I:E ratio of 1:2, an I:E ratio of 1:1 resulted in a modest improvement in oxygenation and decreased shunt fraction during one-lung ventilation.

Patterns of pncA mutations in drug-resistant Mycobacterium tuberculosis isolated from patients in South Korea

BACKGROUND

Pyrazinamide (PZA), one of the most effective anti-tuberculosis drugs, becomes toxic to Mycobacterium tuberculosis when converted to pyrazinoic acid by pyrazinamidase (PZase). PZA resistance is caused mainly by the loss of enzyme activity by mutation.

OBJECTIVE

To investigate the patterns of pncA mutations in PZA-resistant mycobacteria isolated from South Korean patients.

METHODS

Mycobacterial isolates with clinically proven drug resistance were cultured to determine susceptibility to anti-tuberculosis agents. pncA mutations were recognised by sequencing and compared with the relevant wild-type DNA sequence.

RESULTS

Among 108 isolates, 102 were successfully cultured and underwent drug susceptibility testing; all were multidrug-resistant (MDR). pncA mutations were found in 86 cultured isolates (85.1%): 55 (84.6%) in MDR and 31 (86.1%) in extensively drug-resistant isolates. Substitution of a single nucleotide was most common. The most frequent mutations were a deletion that caused a frameshift at nucleotide (nt) 71, a substitution at nt 403 and a substitution at nt 11. Combined, these accounted for ≈ 40% of all mutations. However, 15 samples (14.9%) with defective PZase activity showed no mutation.

CONCLUSION

pncA mutation in M. tuberculosis is a major mechanism of PZA resistance in MDR isolates from patients in South Korea. The patterns of mutation might be more scattered and diverse. DNA-based diagnosis of PZA resistance has potential for the rapid detection of drug resistance.

Elevated levels of macrophage migration inhibitory factor in women with metabolic syndrome

Metabolic syndrome is a complex clinical disorder characterized by obesity, a disturbance of glucose metabolism, dyslipidemia, and hypertension, leading to increased cardiovascular risk. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine produced both by innate immune cells and by adipocytes, and it plays an important role in inflammatory and cardiovascular diseases. The goal of this study was to evaluate the expression of circulating MIF in patients with metabolic syndrome. A study was conducted involving 172 persons who attended the Jeju National University Hospital Health Promotion Center. Among the 172 subjects, 88 patients with metabolic syndrome and 84 healthy control subjects were included. Serum MIF levels were considerably higher in patients with metabolic syndrome than in healthy subjects (mean±SEM, 1413.0-pg/ml±102.6 vs. 1077.0-pg/ml±-91.3, p=0.016). Among the metabolic syndrome patients, MIF levels were significantly increased in women (1403.0-pg/ml±114.2 vs. 921.3 pg/ml±117.3, p=0.005), but not in men. Even after further linear regression adjustment for age and body mass index, the expression of MIF for women with metabolic syndrome was still clearly elevated when compared to healthy subjects (p=0.011). Circulating MIF concentrations showed a gender disparity between healthy and metabolic syndrome subjects. An elevation of systemic MIF in women with metabolic syndrome may contribute to pathogenesis of metabolic syndrome or to the development of metabolic syndrome-related diseases, such as atherosclerosis and type 2 diabetes mellitus.

Detection of antigenic proteins expressed by lymphocystis virus as vaccine candidates in olive flounder, Paralichthys olivaceus (Temminck & Schlegel)

Although the major capsid proteins (MCPs) of lymphocystis disease virus (LCDV) have been characterized, little is known about the host-derived immune response to MCPs and other LCDV antigenic proteins. To identify antigenic proteins of LCDV that could be used as vaccine candidates in olive flounder, Paralichthys olivaceus, we analysed the viral proteins responsible for its virulence by applying immuno-proteomics. LCDV proteins were separated by one-dimensional gel electrophoresis, transferred to polyvinylidene difluoride membrane, and probed with homogeneous P. olivaceus antisera elicited by LCDV natural infection and vaccination with formalin-killed LCDV. Four immune-reactive proteins were obtained at 68-, 51-, 41- and 21 kDa using antisera collected from natural infection while two proteins at 51- and 21 kDa exhibited response to antisera from vaccinated fish, indicating that the latter two proteins have vaccine potential. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nanoelectrospray MS/MS, the 51 and 21 kDa proteins were identified as MCP and an unknown protein, respectively.

In vivo quantification of transvascular water exchange during the acute phase of permanent stroke

Mechanisms that underlie early ischemic damages to the blood-brain-barrier (BBB) are not well understood. This study presents a novel magnetic resonance imaging (MRI) technique using a widely available pulse sequence and a long-circulating intravascular contrast agent to quantify water movements across the BBB at early stages of stroke progression. We characterized the integrity of the BBB by measuring the flip angle dependence of the water exchange-affected MRI signal intensity, to generate an efficient quantitative index of vascular permeability (WEI, or water exchange index). We performed in vivo MRI experiments to measure the transvascular WEI immediately after the permanent filament occlusion of the middle cerebral artery of mice (n = 5), in which we monitored changes in blood volume (V(b)), apparent diffusion coefficient (ADC), and intra-/extravascular WEI for 4 hours. Statistically significant elevations (P < 0.05) of WEI in the ischemic tissue were observed as early as 1 hour after ischemic onset. Initial reduction of the apparent blood volume (V(app)) in the infarct cortex was followed by a continuous increase of V(app) over time. Although the measured ADC in the ipsilesional cortex continuously decreased, the abnormally high intra-/extravascular WEI remained constant at a significantly elevated level, indicating apparent BBB injury at this early stage of stroke.

Infectious complications in living-donor liver transplant recipients: a 9-year single-center experience

BACKGROUND

Infectious complications following living-donor liver transplantation (LDLT) remain a major cause of morbidity and mortality. We analyzed the frequency and type of infectious complications according to the post-transplantation period, and their risk factors with regard to morbidity and mortality.

METHODS

We retrospectively analyzed 208 subjects who had undergone LDLT during a 9-year period.

RESULTS

The rate of infection was 1.69 per patient during the study period. The predominant infections were intra-abdominal infections (37.6%), primary bacteremia (17.4%), and pneumonia (14.5%). Within the first post-transplant month, 140 (39.9%) infections were detected, and catheter-related coagulase-negative staphylococci (44) were the most common infectious agents. During the 2-6-month post-transplant period, 109 infectious episodes occurred (31.1%), and Enterococcus sp. (n=16) related to biliary infection was the most frequent isolate. After the sixth month, 96 infectious episodes (29%) occurred, and biliary tract-related Escherichia coli (n=19) was the major causative organism. The overall mortality was 24.5% (51/208); 1-year survival rate was 88% (196/208). Post-transplant infection-related mortality was 52.9% (27/51). Biliary tract complications, such as biliary stenosis or leakage, significantly increased the mortality (P=0.01); however, reoperation (retransplantation or resurgery for biliary tract obstruction/leakage or to control bleeding) significantly reduced the mortality (P=0.01).

CONCLUSIONS

Our data showed that early catheter removal would mainly aid in reducing infectious complications in the 1-month post-transplantation period. Aggressive management, including reoperation, would lower the mortality in the LDLT recipients.

Immunoproteomic analysis of capsulate and non-capsulate strains of Lactococcus garvieae

A comparative immunoproteomic study was carried out to investigate the immunogenicity of capsulate (KG9408) and non-capsulate (NSS9310) strains of Lactococcus garvieae. Immunoblot assays, following two-dimensional gel electrophoresis (2-DE) for L. garvieae strains, revealed a significant difference between anti-capsulate and anti-non-capsulate rabbit sera with respect to the number and antigenicity of antigenic spots. Anti-capsulate and anti-non-capsulate rabbit sera reacted with an average of 72 and 127 antigenic spots, respectively. The strong reaction of anti-non-capsulate sera with elongation factor (EF)-G and -Tu, and GMP synthase, of the L. garvieae strains identifies these as specific major antigens. This study clearly demonstrates the differences in 2-DE immunoblot profiles between the capsulate and non-capsulate strains of L. garvieae. These differences may be the reason for variations in immunogenicity between capsulate and non-capsulate strains. Glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, arginine deaminase and ornithine carbamoyltransferase were identified from the 2-DE immunoblot profiles of both strains. Therefore, these common antigens are potential markers for the development of vaccines against L. garvieae, irrespective of strain. Immunoproteomics, a powerful tool for studying antigens at the proteomic level, allowed a comparative investigation of the immunogenicity of capsulate and non-capsulate strains of L. garvieae for vaccine development.

Therapeutic use of granulocyte-colony stimulating factor could conceal residual malignant cells in patients with AML1/ETO+ acute myelogenous leukemia

We have experienced a number of cases of AML1/ETO+ acute myelogenous leukemia that showed remission based on bone marrow (BM) morphological criteria, but that revealed clonal abnormalities in most cells by fluorescence in situ hybridization (FISH). Interestingly, most of these cases had AML with AML1/ETO rearrangement. The malignant cells were differentiated and considered mature cells after granulocyte-colony stimulating factor (G-CSF) treatment. To clarify the possible mechanisms underlying this phenomenon, we investigated the expression levels of G-CSFR in AML cells with AML1/ETO rearrangement by flow cytometry and real-time polymerase chain reaction (PCR). The number of AML1/ETO+ cells expressing G-CSFR at baseline was significantly higher than that of AML1/ETO- AML cells (2673 vs 522). In addition, the G-CSFR gene was more highly expressed in AML1/ETO+ cells than in AML1/ETO- cells by real-time PCR. This study reveals that cases showing remission after treatment with G-CSF mostly had leukemia with AML1/ETO rearrangement. This finding might be explained by the higher expression of G-CSF receptor in AML1/ETO+ cells than in AML1/ETO- cells. We recommend that remission should be confirmed by FISH, because malignant clones can be differentiated and masked in morphological examination or chromosome test, especially for AML with AML1/ETO rearrangement.

Protein 4.1 deficiency and deletion of chromosome 20q are associated with acquired elliptocytosis in myelodysplastic syndrome

We report a case of myelodysplastic syndrome (MDS), associated with prominent elliptocytosis. A 66-year-old male presented with peripheral pancytopenia, and was diagnosed with MDS [refractory anaemia (RA)]. Apart from marked elliptocytosis, dyshaematopoietic features were not evident in his peripheral blood or hypercellular bone marrow. After 18 months, he had progressed to RA with excess blasts in transformation. Analysis of red blood cell membrane proteins by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a reduced quantity of protein 4.1 (30% of control). Deletion of chromosome 20q was identified by conventional cytogenetic analysis and fluorescence in situ hybridization. Marked elliptocytosis, persistent for more than 17 months, decreased strikingly after chemotherapy with idarubicin and Ara-C. These findings suggest that acquired elliptocytosis occurred as an unusual morphological feature of MDS, associated with abnormalities of protein 4.1 and chromosome 20q.

Measurement of tumor interstitial volume fraction: Method and implication for drug delivery

It is important to evaluate the tumor interstitial volume fraction that is accessible for drug accumulation during the distribution phase in order to determine the potential efficacy of cancer chemotherapy. In this study, we performed simulations of magnetic resonance imaging (MRI) signal intensity using a two-compartment tissue model for quantitative analyses of absolute interstitial volume measurements while we experimentally characterized a mouse tumor model with a dual MR contrast-agent method. Previously, consecutive intravenous injections of a strictly intravascular T1 contrast agent followed by an extravasating agent were used as a strategy for the quantification of both relative blood volume (Rel_BV) and relative interstitial volume (Rel_ITST) (Weissleder et al. Eur J Cancer 1998;34:1448-1454; Bogdanov et al. Neoplasia 1991;1:438-435). In the current study, we demonstrate that this approach can be further improved, and that it enables one to accurately evaluate both relative and absolute interstitial volumes. The animal data indicated that a significant difference exists between the absolute interstitial volume fractions of subcutaneously implanted MDA PCa 2b tumor and skeletal muscle tissue (27.5 +/- 9.1% and 15.9 +/- 0.7%, respectively (P < 0.05)), while only a minor difference was found for the absolute blood volumes (Abs_BV) (Kim et al. Magn Reson Med 2002;47:1110-1120) of these tissues.

Water exchange and inflow affect the accuracy of T1-GRE blood volume measurements: implications for the evaluation of tumor angiogenesis

The goal of this study was to determine the degree to which vascular water exchange and blood flowing into an imaging slice affect the accuracy of blood volume measurements of brain and tumor tissue when using intravascular T(1) contrast agents. The study was performed using 2D and 3D gradient-echo imaging sequences, since these are two of the most commonly used MRI methods used to evaluate tissue blood volume fraction. Computer simulations were performed and measurements made in a rat 9L gliosarcoma brain tumor model. The computer simulations demonstrate that, with either water exchange or inflow effects alone, the dependence on the physiologic and imaging parameters can be well characterized and therefore potentially offset. In the exchange only case, the parametric dependence of 3D simulations suggest that the best accuracy is achieved with high flip angles, short TR, and low blood contrast agent concentrations. However, for a 2D GRE sequence which is influenced by both water exchange and inflow, the simulations predict that the error trend as a function of the imaging and physiologic parameters is unpredictable and therefore difficult to compensate. With both 2D and 3D GRE the measured blood volume data in rat brain and tumor tissue demonstrate tissue-specific trends, which reflect differences in the considered physiologic parameters. The experimental data strongly support the computer simulations and also indicate that minimization of the physiological effects by proper selection of imaging parameters, contrast concentration, and volume calculation methods is crucial for accurate assessment of absolute blood volume fraction.

Polymorphisms of the CTLA-4 exon 1 and promoter gene in systemic lupus erythematosus

The objective of this study was to determine whether the polymorphisms of the CTLA-4 exon 1 (+49) and promoter (-318) are associated with susceptibility to systemic lupus erythematosus (SLE) and its clinical features. Polymerase chain reaction of genomic DNA-restriction fragment length polymorphism was used to determine genotypes of the CTLA-4 exon 1 (+49) and promoter (-318) in 80 SLE patients and 86 healthy control subjects. The genotype distribution of the CTLA-4 exon 1 (+49) differed between SLE patients and controls (chi2 = 6.74, 2 degrees of freedom (d.f.), P = 0.03). The CTLA-4 AG genotype occurred more frequently in patients with SLE (46.3% vs 33.7% controls). On the other hand, the CTLA-4 AA genotype as well as the CTLA-4 GG genotype was less frequent among SLE patients than among control subjects (1.3% vs 9.3% and 52.5% vs 57.0%, respectively). The genotype distribution of the CTLA-4 promoter (-318) differed between SLE patients and control subjects (CT, TT, CC; genotypes 27.5%, 0%, 72.5% vs 16.3%, 4.7%, 79.1% controls respectively, chi2 = 6.36, 2 d.f., P = 0.04). However, Fischer's exact or chi2 P-values for each genotypes of the CTLA-4 exon 1 (+49) and promoter (-318) between SLE and control group were > 0.05. Clinically, in the lupus patients there was no significant difference according to the CTLA-4 polymorphisms. In conclusion, no correlation was found between CTLA-4 exon 1 (+49) and promoter (-318) polymorphisms and SLE in our study.

Genetic variations of cholesterol ester transfer protein gene in Koreans

An absence of cholesterol ester transfer protein (CETP, protein; CETP, gene) results in an increase of the apolipoprotein AI levels and a decrease in the low density lipoprotein (LDL) levels. Thus, the CETP polymorphism is important in the assessment of risk of atherosclerosis. This study was conducted to elucidate the genotype distributions of the CETP polymorphism and association with plasma lipid levels in Koreans. The genotypes of the TaqI A and B polymorphic loci were associated with plasma triglyceride levels in the control and coronary artery disease (CAD) groups. There was linkage disequilibrium between TaqI A and B loci in the control group (chi2 = 5.58, p < 0.05). Association studies of the CETP polymorphism have been carried out mainly with Caucasian populations; however, the results have not been consistent among different populations. A possible explanation for this diversity among populations may be differences in genetic backgrounds, which may be more important than environmental factors. We discuss the reasons for the incompatibility of the CETP polymorphism among populations.

Folding and stability of sweet protein single-chain monellin. An insight to protein engineering

Engineered single-chain monellin (SCM) proteins were constructed by recombinant technology without disrupting the topology and sweet activity of native protein. Data from 8-anilinonaphthalene-1-sulfonic acid fluorescence, size-exclusion chromatography, and heteronuclear NMR strongly suggest the presence of a folding intermediate at 1.5 m GdnHCl for SCM protein. The structural feature of the folding intermediate from NMR data reveals that the secondary structures became mostly unstable, and protein experiences a dynamic equilibrium between native and unfolded state. All backbone amide protons exchange within 10 min, which imply that no stable hydrogen bonds exist in the secondary structural regions in the folding intermediate. From equilibrium unfolding and mutagenesis studies, the unfolding transition midpoints of mutant proteins gradually shifted toward lower denaturant concentration, indicating stability reductions of mutant proteins. Our results suggest that stability and folding pathways of SCM proteins could be regulated by a combined study of spectroscopy and mutagenesis, and these studies will provide useful information for understanding the folding kinetics of novel engineered proteins.

p53 codon 72 polymorphism and rheumatoid arthritis

OBJECTIVE

To investigate whether the p53 codon 72 polymorphism is associated with susceptibility to rheumatoid arthritis (RA) and its clinical features.

METHODS

A polymerase chain reaction of genomic DNA-restriction fragment length polymorphism was used to determine genotypes of the p53 codon 72 in 114 patients with RA and 114 healthy controls. Clinical/serological manifestations were analyzed in each patient and correlated with the genotypes.

RESULTS

The genotype distribution of the p53 codon 72 did not differ between patients with RA and controls (Arg/Arg, Arg/Pro, Pro/Pro genotypes 38, 58, 18 vs 37, 60, 17 controls, respectively; chi-square = 0.08, 2 df, p = 0.96). No significant difference was found in allele frequencies between the groups. Clinically there was no significant difference in age at onset, functional class, physician's global assessment, ESR, CRP, RF titer, extraarticular and cervical spine involvement, frequencies of joint operation, and admission in RA patients according to the p53 codon 72 genotypes. However, the number of patients within each group was extremely small, for example only 5 patients with cervical spine involvement. No firm conclusions could safely be reached about clinical manifestations from this study.

CONCLUSION

No association was found between the p53 codon 72 polymorphism and RA. Studies are needed to clarify the role of the p53 polymorphism in the pathogenesis of RA.

Effects of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) on the expression of inflammatory cytokines and apoptosis induction in rheumatoid synovial fibroblasts and monocytes

This study was performed to investigate whether peroxisome proliterator-activated receptor-gamma (PPAR-gamma) exerted an anti-inflammatory effect on rheumatoid synovial cells and inhibited dysregulated proliferation. The expression of PPAR-gamma mRNA in cultured human synoviocytes and THP-1 cells was analysed by RT-PCR. PPAR-gamma was expressed in normal, osteoarthritis (OA), rheumatoid arthritis (RA) synovial cells as well as a human monocytic cell line, THP-1. In RA and OA synoviocytes, the induction of inflammatory cytokine mRNA expression such as TNF-alpha and IL-1beta was significantly inhibited by the natural PPAR-gamma agonist, 15 deoxy-Delta(12,14)prostaglandin J(2)(15d-PGJ(2)). The effect of PPAR-gamma on the nuclear factor (NF)-kappaB activity was tested by electrophoretic mobility shift assay (EMSA). Both troglitazone and 15d-PGJ(2)markedly inhibited TNF-alpha-induced NF-kappaB activation at 30 microM. However, PPAR-gamma agonist neither reduced proliferation nor induced apoptosis in RA synoviocytes when measured by XTT assay and fluorescence activated cell sorter (FACS) analysis. In contrast, it induced apoptosis in a dose-dependent manner in THP-1 cells and augmented TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis as well. In conclusion, these data demonstrate that PPAR-gamma is expressed in human synoviocytes and THP-1 cells, and the PPAR-gamma activation inhibits expression of inflammatory cytokines in RA synoviocytes. Furthermore, PPAR-gamma activation induces apoptosis by itself and augments TRAIL/Apo2L-induced apoptosis in THP-1 cells. These results suggest that PPAR-gamma agonists may provide a new therapeutic approach for RA.

Fas promoter -670 polymorphism is associated with development of anti-RNP antibodies in systemic lupus erythematosus

OBJECTIVE

To evaluate whether the polymorphism of Fas promoter -670 is associated with susceptibility to systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) and their clinical features.

METHODS

A polymerase chain reaction of a genomic DNA-restriction fragment length polymorphism was used to determine genotypes of the Fas promoter -670 in 87 patients with SLE, 87 with RA, and 87 healthy controls. A second cohort of SLE patients (n = 85) was included. Clinical manifestations were analyzed in each patient and correlated with the genotypes.

RESULTS

The genotype distribution of the Fas promoter -670 did not differ between patients with SLE and control subjects (AA, GA, GG genotypes 31, 54, 15% vs 30, 55, 15% controls, respectively; chi-squared = 0.03, 2 df, p = 0.99) and between RA patients and controls (AA, GA, GG genotypes 38, 44, 18% vs 30, 55, 15% controls, respectively; chi-squared = 2.30, 2 df, p = 0.32). Regarding the clinical status of lupus patients according to Fas promoter -670 genotypes, there was no significant difference in age at onset, anti-dsDNA titer, C3, C4 level, renal involvement, number of American College of Rheumatology (ACR) criteria met, SLE Disease Activity Index, SLE International Collaborating Clinics/ACR Damage Index, or autoantibody profiles. However, the frequency of anti-RNP antibody was significantly different in the AA, GA, and GG groups (71, 25, 30%; chi-squared = 13.29, 2 df, p = 0.001). To confirm this finding, the Fas promoter -670 genotype was examined in a second cohort of SLE patients (n = 85). The result in the second cohort replicated the association shown in the first. In patients with RA, there was no significant difference in clinical and laboratory findings according to the Fas promoter -670 genotypes.

CONCLUSION

Our data suggest that the Fas promoter -670 polymorphism is associated with development of anti-RNP antibodies in SLE.

Mitochondrial NADH-cytochrome b(5) reductase plays a crucial role in the reduction of D-erythroascorbyl free radical in Saccharomyces cerevisiae

The relevance of NADH-cytochrome b(5) reductase to the NADH-dependent reduction of D-erythroascorbyl free radical was investigated in Saccharomyces cerevisiae. MCR1, which is known to encode NADH-cytochrome b(5) reductase in S. cerevisiae, was disrupted by the insertion of URA3 gene into the gene of MCR1. In the mcr1 disruptant cells, the activity of NADH-D-erythroascorbyl free radical reductase almost disappeared and the intracellular level of D-erythroascorbic acid was about 11% of that of the congenic wild-type strain. In the transformant cells carrying MCR1 in multicopy plasmid, the intracellular level of D-erythroascorbic acid and the activity of NADH-D-erythroascorbyl free radical reductase increased up to 1.7-fold and 2.1-fold, respectively. Therefore, it indicated that the MCR1 product, mitochondrial NADH-cytochrome b(5) reductase, plays a key role in the NADH-dependent reduction of D-erythroascorbyl free radical in S. cerevisiae. On the other hand, the mcr1 disruptant cells were hypersensitive to hydrogen peroxide and menadione, and overexpression of MCR1 made the cells more resistant against oxidative stress. These results suggested that the mitochondrial NADH-cytochrome b(5) reductase functions as NADH-D-erythroascorbyl free radical reductase and plays an important role in the response to oxidative damage in S. cerevisiae.

A case of BOOP developed during bucillamine treatment for rheumatoid

We describe a patient with rheumatoid arthritis(RA) who developed bronchiolitis obliterans organizing pneumonia(BOOP) during the treatment of bucillamine. A 51 year-old man was admitted to the hospital for an abnormal shadow on his chest radiograph. He had been diagnosed as having RA 3 years previously and had been receiving 200 mg of bucillamine for 21 months. Two months prior to admission, he presented with a cough and his chest X-ray showed opacities in both lower lungs. He was treated with antibiotics for 2 months after the development of cough and lesions on the chest X-ray, but the symptoms and lung lesions became more aggravated. On admission, an HRCT revealed airspace consolidations in the subpleural space of both basal lungs and a CT-guided fine needle aspiration biopsy showed Masson's body filling air space, interstitial infiltration of acute and chronic inflammatory cells and type II cell hyperplasia, consistent with BOOP. Bucillamine was stopped and 50 mg of prednisolone was administered. His symptoms and infiltrations on the chest X-ray resolved. We suggest that bucillamine should be considered as a drug possibly associated with BOOP.

Enhancement of lysophosphatidic acid-induced ERK phosphorylation by phospholipase D1 via the formation of phosphatidic acid

We made stable cell lines overexpressing PLD1 (GP-PLD1) from GP+envAm12 cell, a derivative of NIH 3T3 cell. PLD1 activity and extracellular signal-regulated kinase (ERK) phosphorylation were enhanced in GP-PLD1 cells by the treatment of lysophosphatidic acid (LPA). In contrast, these LPA-induced effects were attenuated with the pretreatment of pertussis toxin (PTX) or protein kinase C (PKC) inhibitor. Moreover, accumulation of phosphatidic acid (PA), a product of PLD action, potentiated the LPA-induced ERK activation in GP-PLD1 cells while blocking of PA production with the treatment of 1-butanol attenuated LPA-induced ERK phosphorylation. From these results, we suggest that LPA activate PLD1 through pertussis toxin-sensitive G protein and PKC-dependent pathways, then PA produced from PLD1 activation facilitate ERK phosphorylation.

Regulation of phospholipase D2 by H(2)O(2) in PC12 cells

Phospholipase D2 (PLD2) is expressed in brain and inhibited by synuclein, which is involved in Parkinson's and Alzheimer's diseases. However, the activation mechanism of PLD2 in neuronal cells has not been defined clearly. Hydrogen peroxide (H(2)O(2)) plays roles in the neurodegenerative diseases and also acts as a second messenger of various molecules such as nerve growth factor. To study regulation mechanisms of PLD2 by H(2)O(2) in neuronal cells, we have made stable PC12 cell lines expressing PLD2 (PLD2-PC12 cells). H(2)O(2) treatment stimulated PLD activity in PLD2-PC12 cells in a dose- and time-dependent manner. This activation was inhibited by the treatment with protein kinase C (PKC) inhibitors or by depletion of PKCalpha, -delta, and -epsilon. Phorbol ester markedly activated PLD2. Co-treatment with phorbol ester and H(2)O(2) did not show an additive effect. Chelation of extracellular calcium substantially blocked the H(2)O(2)-induced activation of PLD2. A calcium ionophore induced PLD2 activation in a PKC-dependent manner. Protein-tyrosine kinase inhibitors inhibited H(2)O(2)-induced PLD activation slightly. These data indicate that H(2)O(2) can activate PLD2 in PC12 cells and that this activation is largely dependent on PKC and Ca(2+) ions and minimally dependent on tyrosine phosphorylation.

Galactosylated chitosan-graft-dextran as hepatocyte-targeting DNA carrier

Lactobionic acid bearing galactose group was coupled with chitosan for liver specificity, and dextran was grafted to galactosylated chitosan (GC) for stability in water. Compared to the GC/DNA complex, the stability of the galactosylated chitosan-graft-dextran (GCD)/DNA complex could be enhanced. The particle size of the GCD/DNA complexes decreased as the charge ratio of GCD to DNA increased. Conformational change of DNA did not occur after complex formation with GCD compared with the conformation of DNA itself. The GCD/DNA complexes were only transfected into Chang liver cells and that of Hep G2 having asialoglycoprotein receptors (ASGR), indicative of specific interaction of ASGRs on cells and galactose ligands on chitosan.

Contrast agent-enhanced magnetic resonance imaging of skeletal muscle damage in animal models of muscular dystrophy

Membrane lesions play an early role in the pathogenesis of muscular dystrophy. Using a new albumin-targeted contrast agent (MS-325), sarcolemmal integrity of two animal models for muscular dystrophy was studied by MRI. Intravenously injected MS-325 does not enter skeletal muscle of normal mice. However, mdx and Sgca-null mutant mice, animal models for Duchenne and sarcoglycan-deficient limb-girdle muscular dystrophy, respectively, showed significant accumulation of MS-325 in skeletal muscle. The results suggest that contrast agent-enhanced MRI could serve as a common, noninvasive imaging procedure for evaluating the localization, extent, and mechanisms of skeletal muscle damage in muscular dystrophy. Furthermore, this method is expected to facilitate assessment of therapeutic approaches in these diseases.

A rapid and accurate closed-tube immunoassay for platelets on an automated hematology analyzer

Accurate and precise platelet counts are important for patients with severe thrombocytopenia or who are receiving chemotherapy. We developed a novel flow cytometric analysis of platelets that may be particularly valuable for assessing the necessity for platelet transfusions. This ImmunoPlt (CD61) assay is based in part on CD61 monoclonal antibody labeling and has been automated and implemented on the CELL-DYN 4000 hematology analyzer. It is well suited for thrombocytopenic specimens, since it reduces interference by nonplatelet particles. It takes less than 5 minutes from closed-tube aspiration to report. Data for more than 350 thrombocytopenic specimens demonstrate that the ImmunoPlt (CD61) assay is more accurate than the optical scatter or the impedance count for specimens with platelet counts between 1 and 60 x 10(3)/microL (1 and 60 x 10(9)/L). The ImmunoPlt (CD61) assay is more precise than the optical scatter or the impedance count for specimens with platelet counts between 1 and 50 x 10(3)/microL (1 and 50 x 10(9)/L).

Vibrio vulnificus has the transmembrane transcription activator ToxRS stimulating the expression of the hemolysin gene vvhA

In an attempt to dissect the virulence regulatory mechanism in Vibrio vulnificus, we tried to identify the V. cholerae transmembrane virulence regulator toxRS (toxRS(Vc)) homologs in V. vulnificus. By comparing the sequences of toxRS of V. cholerae and V. parahaemolyticus (toxRS(Vp)), we designed a degenerate primer set targeting well-conserved sequences. Using the PCR product as an authentic probe for Southern blot hybridization, a 1.6-kb BglII-HindIII fragment and a 1.2-kb HindIII fragment containing two complete open reading frames and one partial open reading frame attributable to toxR(Vv), toxS(Vv), and htpG(Vv) were cloned. ToxR(Vv) shared 55.0 and 63.0% sequence homology with ToxR(Vc) and ToxR(Vp), respectively. ToxS(Vv) was 71.5 and 65.7% homologous to ToxS(Vc) and ToxS(Vp), respectively. The amino acid sequences of ToxRS(Vv) showed transmembrane and activity domains similar to those observed in ToxRS(Vc) and ToxRS(Vp). Western blot analysis proved the expression of ToxR(Vv) in V. vulnificus. ToxRS(Vv) enhanced, in an Escherichia coli background, the expression of the V. vulnificus hemolysin gene (vvhA) fivefold. ToxRS(Vv) also activated the ToxR(Vc)-regulated ctx promoter incorporated into an E. coli chromosome. A toxR(Vv) null mutation decreased hemolysin production. The defect in hemolysin production could be complemented by a plasmid harboring the wild-type gene. The toxR(Vv) mutation also showed a reversed outer membrane protein expression profile in comparison to the isogenic wild-type strain. These results demonstrate that ToxR(Vv) may regulate the virulence expression of V. vulnificus.

Development of a fluorogenic probe-based PCR assay for detection of Bacillus cereus in nonfat dry milk

A fluorogenic probe-based PCR assay was developed and evaluated for its utility in detecting Bacillus cereus in nonfat dry milk. Regions of the hemolysin and cereolysin AB genes from an initial group of two B. cereus isolates and two Bacillus thuringiensis isolates were cloned and sequenced. Three single-base differences in two B. cereus strains were identified in the cereolysin AB gene at nucleotides 866, 875, and 1287, while there were no species-consistent differences found in the hemolysin gene. A fluorogenic probe-based PCR assay was developed which utilizes the 5'-to-3' exonuclease of Taq polymerase, and two fluorogenic probes were evaluated. One fluorogenic probe (cerTAQ-1) was designed to be specific for the nucleotide differences at bases 866 and 875 found in B. cereus. A total of 51 out of 72 B. cereus strains tested positive with the cerTAQ-1 probe, while only 1 out of 5 B. thuringiensis strains tested positive. Sequence analysis of the negative B. cereus strains revealed additional polymorphism found in the cereolysin probe target. A second probe (cerTAQ-2) was designed to account for additional polymorphic sequences found in the cerTAQ-1-negative B. cereus strains. A total of 35 out of 39 B. cereus strains tested positive (including 10 of 14 previously negative strains) with cerTAQ-2, although the assay readout was uniformly lower with this probe than with cerTAQ-1. A PCR assay using cerTAQ-1 was able to detect approximately 58 B. cereus CFU in 1 g of artificially contaminated nonfat dry milk. Forty-three nonfat dry milk samples were tested for the presence of B. cereus with the most-probable-number technique and the fluorogenic PCR assay. Twelve of the 43 samples were contaminated with B. cereus at levels greater than or equal to 43 CFU/g, and all 12 of these samples tested positive with the fluorogenic PCR assay. Of the remaining 31 samples, 12 were B. cereus negative and 19 were contaminated with B. cereus at levels ranging from 3 to 9 CFU/g. All 31 of these samples were negative in the fluorogenic PCR assay. Although not totally inclusive, the PCR-based assay with cerTAQ-1 is able to specifically detect B. cereus in nonfat dry milk.

Bright spatial solitons on a partially incoherent background

We present the first observation of incoherent antidark spatial solitons in noninstantaneous nonlinear media. This new class of soliton states involves bright solitons on a partially incoherent background of infinite extent. In the case where the nonlinearity is of the Kerr type, their existence is demonstrated analytically by means of an exact solution. Computer simulations and experiments indicate that these incoherent antidark solitons can propagate in a stable fashion provided that the spatial coherence of their background is reduced below the incoherent modulation instability threshold.

Lyso-PAF analogues and lysophosphatidylcholines from the marine sponge Spirastrella abata as inhibitors of cholesterol biosynthesis

A series of phospholipids, including previously undescribed compounds 4-7, were isolated by a bioactivity-guided fractionation from the marine sponge Spirastrella abata as inhibitors of cholesterol biosynthesis in human liver cells. These compounds were identified as lyso-PAF analogues (1-5) and lysophosphatidylcholines (6, 7) based on NMR and MS analyses. Compounds 1-7 specifically blocked the conversion of lanosterol into cholesterol in the Chang liver cell.

Spectral characterization and chemical modification of FMN-containing ascorbyl free-radical reductase from Pleurotus ostreatus

Ascorbyl free-radical reductase was purified 1143-fold with an overall yield of 9.9% from the cytosolic fraction of Pleurotus ostreatus. The native enzyme had a molecular mass of 127 kDa and SDS/PAGE revealed that the enzyme consists of two subunits, each with a molecular mass of 62 kDa. The enzyme utilized only NADH as an electron donor. The enzyme was highly specific for ascorbyl free radical as an electron acceptor and capable of catalysing the reduction of ferricyanide and 2,6-dichloroindophenol as artificial electron acceptors. The apparent K(m) values of the enzyme towards NADH and ascorbyl free radical were 35+/-0.22 and 2.1+/-0.03 microM, respectively. The catalytic mechanism of this enzyme is of Ping Pong type. The enzyme contained FMN as a prosthetic group and showed the characteristic absorption spectrum ascribed to the charge-transfer interaction of thiolate anion with FMN. The enzyme contained eight cysteine residues per monomer and was inactivated more rapidly by mercurials than by thiol-alkylating reagents. Kinetic analysis of the inactivation process revealed that the enzyme had 1 mol of thiol group/mol of subunit in the active site with a pK(a) of 6.9. The modification of the thiol group of the enzyme caused the loss of charge-transfer absorbance centred at 540 nm and blocked the electron-transfer process from NADH to FMN. The modification of lysine, arginine and histidine residues led to the loss of its activity. Unlike the active enzyme, the fluorescence quenching of NADH was not observed in the lysine-modified enzyme, which implies that lysine residues can participate in the interaction with NADH.

Anti-allergic actions of the leaves of Castanea crenata and isolation of an active component responsible for the inhibition of mast cell degranulation

The anti-allergic actions of the leaves of Castanea crenata (Fagaceae) were studied. The water extract demonstrated potent anti-allergic actions in in vivo and in vitro experiments. The oral or intraperitoneal administration of the extract (100 or 200 mg/kg) caused a significant inhibition of the 48 hr-PCA (up to 90%) and the vascular permeability induced by histamine or serotonin in rats (about 80%). The anaphylactic release of beta-hexosaminidase from RBL-2H3 cells was also significantly inhibited by the extract in a dose-dependent manner with an IC50 value of 230 microg/ml. The activity-guided fractionation of the extract, based on the determination of inhibitory effect upon the release of beta-hexosaminidase, led to the isolation of quercetin as an active principle responsible for the inhibition of degranulation.

Panax ginseng blocks morphine-induced thymic apoptosis by lowering plasma corticosterone level

The effects of Panax ginseng on morphine-induced immune suppression were studied. Morphine (20 mg/kg, SC, 4 days) decreased body weight increment rate and caused atrophy of thymus and spleen. These changes were partly reversed by concomitant administration of ginseng total saponin (GTS, 100 mg/kg, oral, 9 days). Morphine elevated the serum corticosterone level and caused the DNA fragmentation of thymocytes. These sequential events were completely blocked by a concomitant administration of GTS. Flow cytometry analysis showed that GTS specifically blocked morphine-induced apoptosis of thymocytes.