Effects of ethanol on conformational changes of Akt studied by chemical cross-linking, mass spectrometry, and (18)O labeling

Although PI3K/Akt signaling that regulates neuronal survival has been implicated in the deleterious effects of ethanol on the central nervous system, underlying molecular mechanisms have not been fully elucidated. Akt-membrane interaction is a prerequisite step for Akt activation since it induces interdomain conformational changes to an open conformer that allows Akt phosphorylation by upstream kinases. In this study, we investigated the effect of ethanol on Akt activation by quantitatively probing Akt conformation using chemical cross-linking, (18)O labeling and mass spectrometry. We found that ethanol at pharmacologically relevant concentrations (20 or 170 mM) directly interacts with Akt and alters the local pleckstrin homology domain configuration near the PIP(3)-binding site. We also found that ethanol significantly impairs subsequent membrane-induced interdomain conformational changes needed for Akt activation. The observed alteration of Akt conformation caused by ethanol during the activation sequence provides a new molecular basis for the effects of ethanol on Akt signaling. The in vitro conformation-based approach employed in this study should also be useful in probing the molecular mechanisms for the action of ethanol or drugs on other signaling proteins, particularly for those undergoing dramatic conformational change during activation processes such as members of AGC kinase super family.

Robotic thyroid surgery using bilateral axillo-breast approach: personal initial experience over two years

AIM

Although endoscopic thyroid surgery is gaining wide acceptance, however, manual endoscopic operation also has shown several limitations. The advent of robotic surgical systems, such as the da Vinci surgical system (Intuitive Surgical, Mountain View, CA, USA), is expected to make it possible to overcome some limitations of manual endoscopic operation. Herein we report a single surgeon (H.Y.K.)'s initial two-year experience of new robotic thyroid operations using the bilateral axillo-breast approach (BABA), the approach which has definite advantages and recently has been widely used for the traditional endoscopic thyroid surgery.

METHODS

Between July 2008 and July 2010, 93 patients underwent robotic thyroid surgery using the BABA, with the da Vinci-S surgical system, at the Korea University Anam Hospital, Seoul, Korea. The data on the patients' clinicopathological characteristics, operation types, operation times, surgical results, postoperative hospital stays and complications were collected in a prospective manner, and later evaluated.

RESULTS

Seventy-two total thyroidectomies with or without central neck dissections mostly for the papillary carcinomas, twenty lobectomies with or without central neck dissections for the minute ‑ smaller than 0.5 cm in their maximal diameter ‑ papillary carcinomas, follicular neoplasms and benign tumors, and a bilateral subtotal lobectomy for the multinodular goiter were performed robotically. There was no conversion of robotic procedure to traditional endoscopic or open procedure. The mean total operation time was 288.5±48.0 minutes. The mean number of retrieved lymph nodes by the central neck dissection was 5.1±1.97 (range, 0-12). The mean hospital stay of the patients was 2.8±1.2 days. And the mean postoperative 3rd month serum thyroglobulin level in patients undergone total thyroidectomy was 0.3±0.14 ng/mL (range, 0.08-1.95). Three (3.2%) patients suffered from transient hoarseness postoperatively, but all of them recovered in three months. Transient hypocalcemias were observed in 17 out of 72 (23.6%) patients who had undergone total thyroidectomy, but none of them left permanent. No other complication, such as bleeding, infection, neither fluid collection, was observed.

CONCLUSION

Our initial surgical results of robotic thyroid surgery using BABA demonstrate the feasibility and safety of the procedure in the treatment of benign tumors and early differentiated carcinomas.

A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticles

In the present study, we had introduced polyurethane (PU) nanofibers that contain hydroxyapatite (HAp) nanoparticles (NPs) as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination of bovine bones. Typically, a colloidal gel consisting of HAp/PU had been electrospun to form nanofibers. In this communication, physiochemical aspects of prepared nanofibers were characterized by FE-SEM, TEM and TEM-EDS, which confirmed that nanofibers were well-oriented and good dispersion of HAp NPs, over the prepared nanofibers. Parameters, affecting the utilization of the prepared nanofibers in various nano-biotechnological fields have been studied; for instance, the bioactivity of the produced nanofiber mats was investigated while incubating in simulated body fluid (SBF). The results from incubation of nanofibers, indicated that incorporation of HAp strongly activates the precipitation of the apatite-like particles, because of the HAp NPs act as seed, that accelerate crystallization of the biological HAp from the utilized SBF.

Post-translational modification by β-lysylation is required for activity of Escherichia coli elongation factor P (EF-P)

Bacterial elongation factor P (EF-P) is the ortholog of archaeal and eukaryotic initiation factor 5A (eIF5A). EF-P shares sequence homology and crystal structure with eIF5A, but unlike eIF5A, EF-P does not undergo hypusine modification. Recently, two bacterial genes, yjeA and yjeK, encoding truncated homologs of class II lysyl-tRNA synthetase and of lysine-2,3-aminomutase, respectively, have been implicated in the modification of EF-P to convert a specific lysine to a hypothetical β-lysyl-lysine. Here we present biochemical evidence for β-lysyl-lysine modification in Escherichia coli EF-P and for its role in EF-P activity by characterizing native and recombinant EF-P proteins for their modification status and activity in vitro. Mass spectrometric analyses confirmed the lysyl modification at lysine 34 in native and recombinant EF-P proteins. The β-lysyl-lysine isopeptide was identified in the exhaustive Pronase digests of native EF-P and recombinant EF-P isolated from E. coli coexpressing EF-P, YjeA, and YjeK but not in the digests of proteins derived from the vectors encoding EF-P alone or EF-P together with YjeA, indicating that both enzymes, YjeA and YjeK, are required for β-lysylation of EF-P. Endogenous EF-P as well as the recombinant EF-P preparation containing β-lysyl-EF-P stimulated N-formyl-methionyl-puromycin synthesis ∼4-fold over the preparations containing unmodified EF-P and/or α-lysyl-EF-P. The mutant lacking the modification site lysine (K34A) was inactive. This is the first report of biochemical evidence for the β-lysylation of EF-P in vivo and the requirement for this modification for the activity of EF-P.

The association between serum osteocalcin levels and metabolic syndrome in Koreans

The association between serum osteocalcin levels and metabolic syndrome (MS) in Korean individuals was investigated. Serum osteocalcin levels are significantly lower in subjects with MS than in those without the disease, regardless of glucose metabolism.

INTRODUCTION

Osteocalcin was recently shown to affect energy metabolism. In the present study, we investigated the possible association between serum osteocalcin concentrations and MS.

METHODS

A cross-sectional community-based survey was conducted. Serum osteocalcin, type 1 collagen C-telopeptide (CTX) and total alkaline phosphatase (ALP) concentrations were determined in 567 subjects. MS was defined according to NCEP-ATP III criteria.

RESULTS

Serum osteocalcin concentrations were significantly lower in subjects with MS than those without MS in postmenopausal women (18.923 ± 7.685 vs 22.513 ± 7.344 ng/ml, P<0.001) and marginally lower in subjects with MS than those without MS in men (14.550 ± 5.090 vs 16.125 ± 4.749 ng/ml, P=0.086) after adjustment for age and BMI. Further controlling with CTX or ALP did not affect this association in postmenopausal women; however, controlling with osteocalcin abolished the association between CTX and MS. Significant differences in serum osteocalcin levels by MS status were noted in subjects with normal glucose tolerance as well as those with abnormal glucose tolerance (P=0.032 and P<0.001, respectively). Compared with subjects with the highest quartile of osteocalcin, those in the lower quartile groups (Q1-Q3) had significantly increased risks of MS (ORs=5.18, CIs=1.15-23.42) in men. In postmenopausal women, the ORs for MS were significantly higher in the lowest quartile than in the highest quartile (ORs=5.25, CIs=2.42-11.36).

CONCLUSIONS

These findings suggest that osteocalcin is associated with MS, independently of glucose metabolism.

Randomised clinical trial: the efficacy of a 10-day sequential therapy vs. a 14-day standard proton pump inhibitor-based triple therapy for Helicobacter pylori in Korea

BACKGROUND

The eradication rates of Helicobacter pylori (H. pylori) using a proton pump inhibitor (PPI)-based triple therapy have declined due to antibiotic resistance worldwide.

AIM

To compare the eradication rate of the 10-day sequential therapy for H. pylori infection with that of the 14-day standard PPI-based triple therapy.

METHODS

This was a prospective, randomised, controlled study. A total of 409 patients with H. pylori infection were randomly assigned to receive either the 10-day sequential therapy regimen, which consisted of pantoprazole (40 mg) plus amoxicillin (1000 mg) twice a day for 5 days, then pantoprazole (40 mg) with clarithromycin (500 mg) and metronidazole (500 mg) twice a day for another five consecutive days or the 14-day PPI-based triple therapy regimen, which consisted of pantoprazole (40 mg) with amoxicillin (1000 mg) and clarithromycin (500 mg) twice a day for 14 days. The pre- and post-treatment H. pylori status were assessed by rapid urease test, urea breath test, or histology. Successful eradication was confirmed at least 4 weeks after finishing the treatment.

RESULTS

In the intention-to-treat analysis, the eradication rates of the 10-day sequential therapy and of the 14-day PPI-based triple therapy were 85.9% (176/205) and 75.0% (153/205), respectively (P = 0.006). In the per-protocol analysis, the eradication rates were 92.6% (175/205) and 85% (153/204), respectively (P = 0.019). There was no statistically significant difference between the two investigated groups regarding the occurrence of adverse event rates (18.9% vs. 13.3%, P = 0.143).

CONCLUSION

The 10-day sequential therapy achieved significantly higher eradication rates than the 14-day standard PPI-based triple therapy in Korea.

Effects of docosahexaenoic acid on mouse brain synaptic plasma membrane proteome analyzed by mass spectrometry and (16)O/(18)O labeling

Docosahexenoic acid (DHA, 22:6n-3) plays an important role in development of proper brain function in mammals. We have previously reported that DHA promotes synaptogenesis and synaptic function in hippocampal neurons while DHA-depletion in the brain due to n-3 fatty acid deficiency produces opposite effects. To gain insight into underlying molecular mechanisms, we investigated whether the brain DHA status affects the synaptic plasma membrane (SPM) proteome by using nanoLC-ESI-MS/MS and (16)O/(18)O labeling. The DHA level in mouse brains was lowered by dietary depletion of n-3 fatty acids, and SPM was prepared by differential centrifugation followed by osmotic shock. SPM proteins from DHA-adequate and depleted brains were analyzed by nanoLC-ESI-MS/MS after SDS-PAGE, in-gel digestion, and differential O(18)/O(16) labeling. This strategy allowed comparative quantitation of more than 200 distinct membrane or membrane-associated proteins from DHA-adequate or depleted brains. We found that 18 pre- and postsynaptic proteins that are relevant to synaptic physiology were significantly down-regulated in DHA-depleted mouse brains. The protein network analysis suggests involvement of CREB and caspase-3 pathways in the DHA-dependent modulation of synaptic proteome. Reduction of specific synaptic proteins due to brain DHA-depletion may be an important mechanism for the suboptimal brain function associated with n-3 fatty acid deficiency.

Long-term efficacy of entecavir in adefovir-refractory chronic hepatitis B patients with prior lamivudine resistance

This study aimed to evaluate the long-term efficacy of entecavir (ETV) in adefovir (ADV)-refractory chronic hepatitis B (CHB) patients with prior lamivudine (LMV) resistance. A total of 55 ADV-refractory CHB patients with prior LMV resistance, who received rescue therapy with ETV 1 mg daily for at least 12 months, were consecutively enrolled and analysed. Forty-four patients were men, and their median age was 47 (25-69). Ten patients had liver cirrhosis and 46 patients were positive for hepatitis B e antigen (HBeAg). Median hepatitis B virus DNA levels were 6.6 (4.3-8.0) log(10) copies/mL, and the median duration of ETV therapy was 24 (12-47) months. Cumulative virologic response rates at 6, 12, 24 and 36 months were 18%, 29%, 58% and 75%, respectively. HBeAg loss occurred in 10 (21.7%) of 46 HBeAg-positive patients. In multivariate analysis, only initial virologic response at 3 months remained as an independent predictor for virologic response (RR 3.143; 95% CI 1.387-7.120; P = 0.006). The patients with a virological response at 3 months had not only a significantly higher probability of achieving a virologic response (P < 0.001) but also lower probability of experiencing a virologic breakthrough (P = 0.043) than the patients without an early response. Viral breakthrough was observed in 29 patients during the follow-up period. Cumulative breakthrough rates at 6, 12, 24 and 36 months were 0%, 15%, 45% and 73%, respectively. ETV monotherapy may be considerably efficacious in cases with an initial virological response but its efficacy is attenuated by frequent emergence of ETV resistance in ADV-refractory CHB patients with prior LMV resistance.

A synaptogenic amide N-docosahexaenoylethanolamide promotes hippocampal development

Docosahexaenoic acid (DHA), the n-3 essential fatty acid that is highly enriched in the brain, increases neurite growth and synaptogenesis in cultured mouse fetal hippocampal neurons. These cellular effects may underlie the DHA-induced enhancement of hippocampus-dependent learning and memory functions. We found that N-docsahexaenoylethanolamide (DEA), an ethanolamide derivative of DHA, is a potent mediator for these actions. This is supported by the observation that DHA is converted to DEA by fetal mouse hippocampal neuron cultures and a hippocampal homogenate, and DEA is present endogenously in the mouse hippocampus. Furthermore, DEA stimulates neurite growth and synaptogenesis at substantially lower concentrations than DHA, and it enhances glutamatergic synaptic activities with concomitant increases in synapsin and glutamate receptor subunit expression in the hippocampal neurons. These findings suggest that DEA, an ethanolamide derivative of DHA, is a synaptogenic factor, and therefore we suggest utilizing the term 'synaptamide'. This brief review summarizes the neuronal production and actions of synaptamide and describes other N-docosahexaenoyl amides that are present in the brain.

MALDI mass spectrometric imaging of lipids in rat brain injury models

Matrix-assisted laser desorption ionization/ionization imaging mass spectrometry (MALDI IMS) with a time-of-flight analyzer was used to characterize the distribution of lipid molecular species in the brain of rats in two injury models. Ischemia/reperfusion injury of the rat brain after bilateral occlusion of the carotid artery altered appearance of the phospholipids present in the hippocampal region, specifically the CA1 region. These brain regions also had a large increase in the ion abundance at m/z 548.5 and collisional activation supported identification of this ion as arising from ceramide (d18:1/18:0), a lipid known to be associated with cellular apoptosis. Traumatic brain injury model in the rat was examined by MALDI IMS and the area of damage also showed an increase in ceramide (d18:1/18:0) and a remarkable loss of signal for the potassium adduct of the most abundant phosphocholine molecular species 16:0/18:1 (PC) with a corresponding increase in the sodium adduct ion. This change in PC alkali attachment ion was suggested to be a result of edema and influx of extracellular fluid likely through a loss of Na/K-ATPase caused by the injury. These studies reveal the value of MALDI IMS to examine tissues for changes in lipid biochemistry and will provide data needed to eventually understand the biochemical mechanisms relevant to tissue injury.

Abstract 4746: Type I NKT cells mediate anti-tumor immunity through a TNF-α- and NOS-dependent pathway when stimulated with β-ManCer

CD1d-restricted type I NKT cells have been shown to play a critical role in the induction of tumor immunity by producing IFN-γ, which activates effector arms such as NK cells and CD8+ T cells. It has been considered that IFN-γ is necessary for type I NKT cell-induced tumor immunity. In this study, we show that type I NKT cells can induce strong tumor immunity through an IFN-γ-independent pathway when activated with a new type of agonistic antigen, β-mannosylceramide (β-ManCer). The protection induced by β-ManCer treatment was completely abrogated in type I NKT cell deficient Jα18 KO mice. With the observations that in vitro activation of type I NKT cells by β-ManCer was blocked by anti-CD1d blocking monoclonal antibody and that β-ManCer-loaded CD1d dimers bind to type I NKT cells and stimulate type I NKT cell hybridomas in an APC-free system, we concluded that recognition of CD1d presented β-ManCer by a TCR of type I NKT cells is necessary for the protection. Surprisingly β-ManCer-induced protection was not abrogated in IFN-γ deficient mice, which is in contrast with the protection induced by a prototypic agonist α-galactosylceramide (α-GalCer). Instead, β-ManCer-induced protection was dependent on nitric oxide synthase (NOS) and TNF-α since blockade of either completely abrogated the protection while the blockade did not affect protection induced by α-GalCer. The conclusion that NKT cells activated with β-ManCer utilize a different pathway from that used by the cells activated with α-GalCer to enhance tumor immunity was confirmed with the observation that the combination of both antigens synergistically enhanced tumor immunity when suboptimal doses of each were used. These data demonstrate that NKT cells mediate tumor immunity through a TNF-α- and NOS-dependent pathway when stimulated with β-ManCer and that β-ManCer represents a new class of type I NKT cell agonist. Since we observed that human type I NKT cells also can be activated by β-ManCer, β-ManCer may provide a new intervention against cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4746. doi:10.1158/1538-7445.AM2011-4746

Comparative histopathological characteristics of highly pathogenic avian influenza (HPAI) in chickens and domestic ducks in 2008 Korea

We compared characteristic lesions occurring in chickens and domestic ducks naturally infected with H5N1 HPAI virus in April and May 2008. Infected chickens generally exhibited pale-green, watery diarrhoea, depression, neurological signs and cyanosis of wattles and combs, and infected ducks generally exhibited neurological signs and watery diarrhoea. Gross petechial or ecchymotic haemorrhage affected the heart, proventriculus, liver, muscle, fat, and pancreas in chickens, and muscle in ducks. Necrotic foci were primarily present in the pancreas of both species and in the heart of domestic ducks. Histopathologically, chickens exhibited multifocal encephalomalacia, multifocal lymphohistiocytic myocarditis, multifocal necrotic pancreatitis and haemorrhage of several organs and tissues; ducks exhibited lymphohistiocytic meningoencephalitis with multifocal haemorrhages, multifocal necrotic pancreatitis, and severe necrotic myocarditis with mineralisation. The characteristic histopathologic findings of 2008 HPAI were multifocal encephalomalacia and necrotic pancreatitis accompanied by lymphohistiocytic myocarditis, and haemorrhage in various organs and tissues in chickens, whereas in ducks, they were severe necrotic myocarditis with mineralisation and necrotic pancreatitis, accompanied with lymphohistiocytic meningoencephalitis. The high mortality of domestic ducks may be intimately associated with heart failure resulting from increased H5N1 HPAI viral cardiotropism.

Phosphatidylserine is a critical modulator for Akt activation

Akt activation relies on the binding of Akt to phosphatidylinositol-3,4,5-trisphosphate (PIP(3)) in the membrane. Here, we demonstrate that Akt activation requires not only PIP(3) but also membrane phosphatidylserine (PS). The extent of insulin-like growth factor-induced Akt activation and downstream signaling as well as cell survival under serum starvation conditions positively correlates with plasma membrane PS levels in living cells. PS promotes Akt-PIP(3) binding, participates in PIP(3)-induced Akt interdomain conformational changes for T308 phosphorylation, and causes an open conformation that allows for S473 phosphorylation by mTORC2. PS interacts with specific residues in the pleckstrin homology (PH) and regulatory (RD) domains of Akt. Disruption of PS-Akt interaction by mutation impairs Akt signaling and increases susceptibility to cell death. These data identify a critical function of PS for Akt activation and cell survival, particularly in conditions with limited PIP(3) availability. The novel molecular interaction mechanism for Akt activation suggests potential new targets for controlling Akt-dependent cell survival and proliferation.

Translationally controlled tumor protein induces human breast epithelial cell transformation through the activation of Src

Translationally controlled tumor protein (TCTP) is implicated in cell growth and malignant transformation. TCTP has been found to interact directly with the third cytoplasmic domain of the α subunit of Na,K-ATPase, but whether this interaction has a role in tumorigenesis is unclear. In this study, we examined TCTP-induced tumor progression signaling networks in human breast epithelial cells, using adenoviral infection. We found that TCTP (a) induces Src release from Na,K-ATPase α subunit and Src activation; (b) phosphorylates tyrosine residues 845, 992, 1086, 1148 and 1173 on anti-epidermal growth factor receptor (EGFR); (c) activates PI3K (phosphatidylinositol 3-kinase )-AKT, Ras-Raf-MEK-ERK1/2, Rac-PAK1/2, MKK3/6-p38 and phospholipase C (PLC)-γ pathways; (d) enhances NADPH oxidase-dependent reactive oxygen species (ROS) generation; (e) stimulates cytoskeletal remodeling and cell motility and (f) upregulates matrix metalloproteinase (MMP) 3 and 13. These findings suggest that TCTP induces tumorigenesis through distinct multicellular signaling pathways involving Src-dependent EGFR transactivation, ROS generation and MMP expression.

Mouse and human iNKT cell agonist β-mannosylceramide reveals a distinct mechanism of tumor immunity

Type 1 or invariant NKT (iNKT) cell agonists, epitomized by α-galactosylceramide, protect against cancer largely by IFN-γ-dependent mechanisms. Here we describe what we believe to be a novel IFN-γ-independent mechanism induced by β-mannosylceramide, which also defines a potentially new class of iNKT cell agonist, with an unusual β-linked sugar. Like α-galactosylceramide, β-mannosylceramide directly activates iNKT cells from both mice and humans. In contrast to α-galactosylceramide, protection by β-mannosylceramide was completely dependent on NOS and TNF-α, neither of which was required to achieve protection with α-galactosylceramide. Moreover, at doses too low for either alone to protect, β-mannosylceramide synergized with α-galactosylceramide to protect mice against tumors. These results suggest that treatment with β-mannosylceramide provides a distinct mechanism of tumor protection that may allow efficacy where other agonists have failed. Furthermore, the ability of β-mannosylceramide to synergize with α-galactosylceramide suggests treatment with this class of iNKT agonist may provide protection against tumors in humans.

Effectiveness of slow freezing and vitrification for long-term preservation of mouse ovarian tissue

This study was conducted to evaluate the interaction between cryo-damage and ART outcome after cryopreservation of mouse ovarian tissues with different methods. Either a vitrification or a slow freezing was employed for the cryopreservation of B6CBAF1 mouse ovaries and follicle growth and the preimplantation development of intrafollicular oocytes following parthenogenesis or IVF were monitored. Both cryopreservation protocols caused significant damage to follicle components, including vacuole formation and mitochondrial deformities. Regardless of the cryopreservation protocols employed, a sharp (P < 0.0001) decrease in follicle viability and post-thaw growth was detected. When IVF program was employed, significant (P < 0.05) decrease in cleavage and blastocyst formation was notable in both modes of cryopreservation. However, such retardation was not found when oocytes were parthenogenetically activated. In the IVF oocytes, slow freezing led to better development than vitrification. In conclusion, a close relationship between cryopreservation and ART methods should be considered for the selection of cryopreservation program.

Risk factors for device-associated infection related to organisational characteristics of intensive care units: findings from the Korean Nosocomial Infections Surveillance System

Device-associated infections (DAIs) have been the major causes of morbidity and mortality of patients in intensive care units (ICUs). This study evaluated the risk factors for DAIs in ICUs. Ninety-six medical or surgical ICUs of 56 hospitals participated in the Korean Nosocomial Infections Surveillance System between July 2007 and June 2008. The occurrence of catheter-associated urinary tract infection (CAUTI), central line-associated bloodstream infection (CABSI), and ventilator-associated pneumonia (VAP) were monitored and DAI rates were calculated. Data associated with ICU characteristics were collected and Poisson regression was used for statistical analysis. Rates of CAUTI, CABSI, and VAP were 3.87 per 1000 urinary catheter days, 2.23 per 1000 central line days, and 1.89 per 1000 mechanical ventilator days, respectively. Rates of CAUTI were higher in ICUs in Seoul (P=0.032) and ICUs of major teaching hospitals (P=0.010). The ICUs of university-affiliated hospitals showed lower CAUTI rates (P=0.013). CABSI rates were higher in Seoul (P=0.001) and in medical ICUs (P=0.026). VAP rates were lower in ICUs of hospitals with more than 900 beds compared with hospitals with 400-699 beds (P=0.026). VAP rates were higher in surgical ICUs (P<0.0001) and increased 1.13-fold with each 100-unit increase in beds per infection control professional (P=0.003). The organisational and institutional characteristics of ICUs may influence DAI rates and there is a need for improvement in the incidence of VAP, CAUTI or CABSI.

Phospholipid profile in the postmortem hippocampus of patients with schizophrenia and bipolar disorder: no changes in docosahexaenoic acid species

Previous studies with postmortem brain tissues showed abnormalities not only in n-3 long-chain polyunsaturated fatty acids (PUFA) but also in phospholipid metabolism in the cortex of individuals with schizophrenia and mood disorder. In this study we investigated whether there is similar abnormality in n-3 long-chain PUFAs and/or in phospholipid profile in the hippocampus of schizophrenia and bipolar disorder patients compared to unaffected controls. Using high-performance liquid chromatography/electrospray ionization-mass spectrometry (LC/MS), the phospholipid contents in the postmortem hippocampus from 35 individuals with schizophrenia, 34 individuals with bipolar disorder and 35 controls were evaluated. Unlike the previous findings form orbitofrontal cortex, we found no significant differences in either n-3 long-chain PUFA or total phosphatidylserine (PS), phosphatidylethanolamine (PE) and phosphatidylcholine (PC). However, docosapentaenoic acid (n-6, 22:5n-6)-PS and 22:5n-6-PC were significantly lower in individuals with schizophrenia or bipolar disorder than the controls. When fatty acid contents were estimated from PS, PE and PC, 22:5n-6 was significantly lower in both patient groups compared to the controls. From these results we concluded that DHA loss associated with these psychiatric disorders may be specific to certain regions of the brain. The selective decrease in 22:5n-6 without affecting DHA contents suggests altered lipid metabolism, particularly n-6 PUFA rather than n-3 PUFA, in the hippocampus of individuals with schizophrenia or bipolar disorder.

Substance P sensitizes P2X3 in nociceptive trigeminal neurons

Peripheral inflammation produces pain hypersensitivity by sensitizing nociceptors. Potentiation of P2X3 receptor activity in nociceptors may play an important role in this peripheral sensitization. However, we do not fully understand how P2X3 activity is elevated in inflammation. Thus, we investigated whether P2X3 activity in trigeminal nociceptive neurons is regulated by the neurokinin-1 (NK-1) receptor that is activated by an inflammatory mediator, substance P. Single-cell RT-PCR and immunohistochemistry revealed that NK-1 in nociceptive neurons was mainly co-expressed with P2X3. Ca(2+) imaging and whole-cell patch-clamp recordings indicated that both substance P and Sar-substance P, a selective NK-1 agonist, significantly potentiated α,β-meATP-induced currents and [Ca(2+)](i) responses in nociceptive neurons. These potentiating effects were completely blocked by GR82334, a specific NK-1 antagonist. Our results demonstrate that substance P sensitizes P2X3 receptor through the activation of NK-1, thus warranting these receptors as possible targets for pain therapy in the orofacial region.

ABBREVIATIONS

α,β-methylene adenosine 5'-triphosphate (ATP), α,β-meATP; neurokinin-1, NK-1; single-cell reverse-transcription polymerase chain-reaction, single-cell RT-PCR; [Sar(9),Met(O(2))(11)]-substance P, Sar-substance P.

Putative association of transforming growth factor-alpha polymorphisms with clearance of hepatitis B virus and occurrence of hepatocellular carcinoma in patients with chronic hepatitis B virus infection

Previous studies showed that several genetic polymorphisms might influence the clinical outcome of chronic hepatitis B virus (HBV) infection, including HBV clearance or development of hepatocellular carcinoma (HCC). The aim of this study was to determine whether polymorphisms of the transforming growth factor-alpha (TGF-alpha) gene are associated with clinical outcome of HBV infection. A total of 1096 Korean subjects having either present or past evidence of HBV infection were prospectively enrolled between January 2001 and August 2003. Among 16 genetic variants in TGFA gene, nine variants were genotyped using TaqMan assay and the genetic association with HBV clearance and HCC occurrence was analysed. Statistical analyses revealed that TGFA+103461T>C, TGFA+106151C>G and TGFA-ht2 were marginally associated with clearance of HBV infection. However, only TGFA-ht2 retained significance after multiple correction (OR = 0.39, P(corr) = 0.007 in recessive model). Although no variants were significant after multiple correction, TGFA+88344G>A and TGFA+103461T>C were weakly associated in recessive model in the analysis of HCC occurrence. In addition, Cox relative hazards model also revealed that TGFA+88344G>A was associated with onset age of HCC occurrence in subjects (RH = 1.46, P(corr) = 0.04). TGF-alpha polymorphisms might be an important factor in immunity, progression of inflammatory process and carcinogenesis, which explains the variable outcome of HBV infection at least in part. Further biological evidence is warranted in the future to support these suggestive associations.

Deletions in a dspm insert in a maize bronze-1 allele alter RNA processing and gene expression

The bz-m13 allele of the bronze-1 (bz) locus in maize contains a 2.2-kb defective Suppressor-mutator (dSpm) transposable element inserted in the second exon. We compared bz expression in bz-m13 and five derivatives in which the dSpm insertion had sustained deletions ranging from 2 to 1300 bp. Tissues homozygous for bz-m13 in the absence of Spm-s activity were found to contain from 5 to 13% of the enzymatic activity conditioned by a wild-type allele at the bz locus. Tissues homozygous for the deletion derivatives contained enzymatic activities ranging from less than 1% to 67%. These differences are closely correlated with the steady-state level of one of two alternatively spliced transcripts. In all alleles bz transcription proceeds through the dSpm insert. Subsequent RNA processing uses the donor site of the single bz intron and either one of two alternative acceptor splice sites (AS1 and AS2) located within the dSpm sequence. Use of the AS1 removes all but 2 bp of dSpm sequence and produces the 1.8-kb transcript whose level corresponds closely to the level of enzymatic activity. Use of AS2 produces a transcript which retains more than 600 bp of dSpm sequence. Those derivatives in which AS2 is either deleted or inactivated have substantially increased levels of both the 1.8-kb transcript and enzymatic activity. We therefore document one sequence of events which began with the insertion of a transposable element and resulted in novel and stable introns which retain element-derived sequence and which in certain cases permit substantial host-gene expression.

Comparison of stroke volume variations derived from radial and femoral arterial pressure waveforms during liver transplantation

BACKGROUND

Stroke volume variation (SVV) is being increasingly used to predict fluid responsiveness. Since radial arterial pressure (RAP) and femoral arterial pressure (FAP) frequently showing discrepancies during liver transplantation (LT), we sought to investigate the effect of differing arterial waveforms on SVV and cardiac output (CO) derived from the Vigileo device, by comparing SVV and CO values derived from RAP (SVV(RAP), CO(RAP)) and FAP (SVV(FAP), CO(FAP)) during LT.

METHODS

The linear associations and agreements between SVV(RAP) and SVV(FAP) and between CO(RAP) and CO(FAP) were assessed during LT. Hemodynamic variables were measured at nine predefined time points in all 32 recipients, resulting in 288 data pairs.

RESULTS

Correlations were observed between SVV(RAP) and SVV(FAP) (r = .961) and between CO(RAP) and CO(FAP) (r = .848) at all time points. These correlations between SVV(RAP) and SVV(FAP) (r = .923) and between CO(RAP) and CO(FAP) (r = .902) existed even during the period when mean RAP and FAP values differed (10 minutes after reperfusion). Bland-Altman analysis for SVV(RAP) versus SVV(FAP) and for CO(RAP) versus CO(FAP) showed weak biases (-0.2% and -0.5 L/min) and reasonable limits of agreement (-2.2 to 1.8% and -1.9 to 0.9 L/min). The percentage errors for SVV and CO values were 27.0% and 22.2%.

CONCLUSIONS

There was no significant difference between SVV(RAP) and SVV(FAP) when measured using the Vigileo device during LT. This finding indicated that SVV obtained using the Vigileo device offered relatively consistent information regardless of the catheterization site.

Abstract 5613: Beta-mannosylceramide: a novel NKT cell agonist which synergizes with alpha-galactocylceramide to induce protection against tumors

Type I natural killer T (NKT) cells are a unique subset of T cells which express phenotypic and functional characteristics of both NK cells and T cells. NKT cells recognize glycolipid antigens presented by the non-classical MHC-like molecule CD1d. Upon stimulation with the prototypical type I NKT cell antigen α-galactosylceramide (α-GalCer), type I NKT cells promote tumor immunity through IFN-γ-dependent mechanims. In this study the ability of glycosylceramides with alterations of the sugar moiety to induce anti-tumor immune responses in an in vivo model of CT26 colon carcinoma metastasis to lungs of BALB/c mice was investigated. β-mannosylceramide (β-ManCer) induced strong tumor protection, while α-mannosylceramide and α-fucosylceramide did not. This is the first evidence of a glycosylceramide with a β-linked sugar moiety capable of inducing significant NKT cell-dependent anti-tumor immunity. We also confirmed that β-ManCer could protect at least as well as α-GalCer in a model of B16F10 melanoma lung metastasis in C57BL/6 mice. Interestingly, β-ManCer induced little cytokine production and retained protective activity in IFN-γ KO mice, unlike α-GalCer analogs which where completely dependent upon IFN-γ. The protection did not require CD8+ T cells, and was largely independent of NK cells. Blockade of nitric oxide synthase or TNF-α significantly reversed the β-ManCer-induced protection but had no effect on tumor protection for the α-GalCer analogs. Thus, contrary to α-GalCer, β-ManCer protects through a novel TNF-α and NOS-dependent, IFN-γ-independent mechanism. Consistent with the conclusion that β-ManCer and α-GalCer induce tumor immunity by distinct mechanisms, simultaneous administration of sub-therapeutic doses of these glycolipids resulted in synergistic reduction in the number of lung metastases. The distinct mechanism of action and ability to synergize with α-GalCer may suggest that β-ManCer represents a new class of NKT agonists with novel clinical applications.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5613.

Phosphatidylserine-dependent neuroprotective signaling promoted by docosahexaenoic acid

Enrichment of polyunsaturated fatty acids, particularly docosahexaenoic acid (DHA, 22:6n-3), in the brain is known to be critical for optimal brain development and function. Mechanisms for DHA's beneficial effects in the nervous system are not clearly understood at present. DHA is incorporated into the phospholipids in neuronal membranes, which in turn can influence not only the membrane chemical and physical properties but also the cell signaling involved in neuronal survival, proliferation and differentiation. Our studies have indicated that DHA supplementation promotes phosphatidylserine (PS) accumulation and inhibits neuronal cell death under challenged conditions, supporting a notion that DHA is an important neuroprotective agent. This article summarizes our findings on the DHA-mediated membrane-related signaling mechanisms that might explain some of the beneficial effects of DHA, particularly on neuronal survival.

Beta-mannosylceramide represents a new class of NKT agonists that induces tumor immunity by a novel IFN-γ-independent mechanism. (89.7)

Type I NKT cells are a unique lymphocyte population which recognize lipid antigens presented by the non-classical MHC-like molecule CD1d. Activation of type I NKT cells by α-galactosylceramide (α-GC) induces tumor immunity by IFN-γ dependent mechanisms. In this study, we characterized how modifications of the sugar head group of α-GC impacted tumor protection in an in vivo mouse model of lung metastasis. β-mannosylceramide (β-ManCer), but not α-mannosylceramide or α-fucosylceramide, induced strong type I NKT cell-dependent tumor immunity. Because this is the first report of a β-linked glycosylcermide capable of inducing significant type I NKT cell-mediated tumor protection, we further characterized the mechanism by which β-ManCer induced tumor elimination. Interestingly, unlike α-GC and its analogs which protected through IFN-γ dependent mechanisms, β-ManCer induced very little cytokine production both in vitro and in vivo and retained protection in the absence of IFN-γ. Rather, β-ManCer protected through a TNF-α and nitric oxide synthase-dependent mechanism novel for NKT cells. Simultaneous administration of sub-therapeutic doses of β-ManCer and α-GC resulted in synergistic reduction in tumor burden, supporting the conclusion that these glycolipids work through different mechanisms. The distinct mechanism of action of β-ManCer and its ability to synergize with α-GC suggest that β-ManCer is the first representative of a new class of type I NKT cell agonists.

A critical evaluation of influence of ethanol and diet on salsolinol enantiomers in humans and rats

BACKGROUND

(R/S)-Salsolinol (SAL), a condensation product of dopamine (DA) with acetaldehyde, has been speculated to have a role in the etiology of alcoholism. Earlier studies have shown the presence of SAL in biological fluids and postmortem brains from both alcoholics and nonalcoholics. However, the involvement of SAL in alcoholism has been controversial over several decades, since the reported SAL levels and their changes after ethanol exposure were not consistent, possibly due to inadequate analytical procedures and confounding factors such as diet and genetic predisposition. Using a newly developed mass spectrometric method to analyze SAL stereoisomers, we evaluated the contribution of ethanol, diet, and genetic background to SAL levels as well as its enantiomeric distribution.

METHODS

Simultaneous measurement of SAL enantiomers and DA were achieved by high performance liquid chromatography-tandem mass spectrometry (HPLC/MS/MS). Plasma samples were collected from human subjects before and after banana (a food rich in SAL) intake, and during ethanol infusion. Rat plasma and brain samples were collected at various time points after the administration of SAL or banana by gavage. The brain parts including nucleus accumbens (NAC) and striatum (STR) were obtained from alcohol-non-preferring (NP) or alcohol-preferring (P) rats as well as P-rats which had a free access to ethanol (P-EtOH).

RESULTS

Plasma SAL levels were increased significantly after banana intake in humans. Consistently, administration of banana to rats also resulted in a drastic increase of plasma SAL levels, whereas brain SAL levels remained unaltered. Acute ethanol infusion did not change SAL levels or R/S ratio in plasma from healthy humans. The levels of both SAL isomers and DA were significantly lower in the NAC of P rats in comparison to NP rats. The SAL levels in NAC of P rats remained unchanged after chronic free-choice ethanol drinking. There were decreasing trends of SAL in STR and DA in both brain regions. No changes in enantiomeric ratio were observed after acute or chronic ethanol exposure.

CONCLUSIONS

SAL from dietary sources is the major contributor to plasma SAL levels. No significant changes of SAL plasma levels or enantiomeric distribution after acute or chronic ethanol exposure suggest that SAL may not be a biomarker for ethanol drinking. Significantly lower SAL and DA levels observed in NAC of P rats may be associated with innate alcohol preference.

Docosahexaenoic acid promotes hippocampal neuronal development and synaptic function

Docosahexaenoic acid (DHA, 22:6n-3), the major polyunsaturated fatty acid accumulated in the brain during development, has been implicated in learning and memory, but underlying cellular mechanisms are not clearly understood. Here, we demonstrate that DHA significantly affects hippocampal neuronal development and synaptic function in developing hippocampi. In embryonic neuronal cultures, DHA supplementation uniquely promoted neurite growth, synapsin puncta formation and synaptic protein expression, particularly synapsins and glutamate receptors. In DHA-supplemented neurons, spontaneous synaptic activity was significantly increased, mostly because of enhanced glutamatergic synaptic activity. Conversely, hippocampal neurons from DHA-depleted fetuses showed inhibited neurite growth and synaptogenesis. Furthermore, n-3 fatty acid deprivation during development resulted in marked decreases of synapsins and glutamate receptor subunits in the hippocampi of 18-day-old pups with concomitant impairment of long-term potentiation, a cellular mechanism underlying learning and memory. While levels of synapsins and NMDA receptor subunit NR2A were decreased in most hippocampal regions, NR2A expression was particularly reduced in CA3, suggesting possible role of DHA in CA3-NMDA receptor-dependent learning and memory processes. The DHA-induced neurite growth, synaptogenesis, synapsin, and glutamate receptor expression, and glutamatergic synaptic function may represent important cellular aspects supporting the hippocampus-related cognitive function improved by DHA.

Probing Akt-inhibitor interaction by chemical cross-linking and mass spectrometry

The serine/threonine kinase Akt is a critical enzyme that regulates cell survival. As high Akt activity has been shown to contribute to the pathogenesis of various human malignancies, inhibition of Akt activation is a promising therapeutic strategy for cancers. We have previously demonstrated that changes in Akt interdomain arrangements from a closed to open conformation occur upon Akt-membrane interaction, which in turn allows Akt phosphorylation/activation. In the present study, we demonstrate a novel strategy to discern mechanisms for Akt inhibition based on Akt conformational changes using chemical cross-linking and (18)O labeling mass spectrometry. By quantitative comparison of two interdomain cross-linked peptides, which represent the proximity of the domains involved, we found that the binding of Akt to an inhibitor (PI analog) caused the open interdomain conformation where the PH and regulatory domains moved away from the kinase domain, even before interacting with membranes, subsequently preventing translocation of Akt to the plasma membrane. In contrast, the interdomain conformation remained unchanged after incubating with another type of inhibitor (peptide TCL1). Subsequent interaction with unilamellar vesicles suggested that TCL1 impaired particularly the opening of the PH domain for exposing T308 for phosphorylation at the plasma membrane. This novel approach based on the conformation-based molecular interaction mechanism should be potentially useful for drug discovery efforts for specific Akt inhibitors or anti-tumor agents.

Physiology and pathophysiology of the 5‐HT3receptor

OBJECTIVE

Macrophage inhibitory protein-1alpha (MIP-1alpha), a C-C chemokine, stimulates the activation and migration of leukocytes. We investigated the expression of MIP-1alpha in patients with Behçet's disease (BD) and evaluated the association of the MIP-1alpha levels with disease activity of BD.

METHODS

Serum samples were obtained from 67 BD patients and 30 healthy controls. Simultaneously, whole blood cells were isolated from BD patients (n = 25) and healthy controls (n = 11) and cultured in the absence or presence of lipopolysaccharide (LPS), phytohaemagglutinin (PHA), and phorbol 12-myristate 13-acetate (PMA) plus ionomycin. The concentrations of MIP-1alpha, interleukin-8 (IL-8), regulated on activation, normally T cell expressed and secreted (RANTES), and monocyte chemoattractant protein-1 (MCP-1) were measured in the sera and culture supernatants by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The serum levels of MIP-1alpha were higher in BD patients than in healthy controls. When whole blood cells were stimulated with LPS or PMA plus ionomycin, but not PHA, BD patients had higher levels of MIP-1alpha in the culture supernatants compared to healthy controls. In sera and culture supernatants of whole blood cells, MIP-1alpha levels correlated well with those of RANTES, MCP-1, and IL-8 in BD patients. Moreover, patients with active disease had significantly higher levels of serum MIP-1alpha levels compared with those with inactive disease.

CONCLUSION

MIP-1alpha levels were elevated in patients with BD, and correlated well with IL-8, RANTES, and MCP-1 levels. These results suggest that the increased MIP-1alpha levels in serum of BD patients may lead to activation and migration of leukocytes, playing a role, like other chemokines, in the pathogenesis of BD.

Diagnosis in the first trimester of placenta accreta with previous Cesarean section

The prenatal diagnosis of adherent placenta is clinically very important, as this condition can seriously affect perinatal mortality and morbidity. The outcome is generally worse in cases with a history of Cesarean section. Here we report a case of placenta increta associated with previous Cesarean delivery, diagnosed by sonography during the first trimester, enabling earlier counseling of the parents and planning of appropriate treatment.

Conformational changes in Akt1 activation probed by amide hydrogen/deuterium exchange and nano-electrospray ionization mass spectrometry

Amide hydrogen exchange coupled to nano-electrospray ionization mass spectrometry (nano-ESI-MS) has been used to identify and characterize localized conformational changes of Akt upon activation. Active or inactive Akt was incubated in D(2)O buffer, digested with pepsin, and analyzed by nano-ESI-MS to determine the deuterium incorporation. The hydrogen/deuterium (H/D) exchange profiles revealed that Akt undergoes considerable conformational changes in the core structures of all three individual domains after activation. In the PH domain, four beta-strand (beta1, beta2 beta5 and beta6) regions containing membrane-binding residues displayed higher solvent accessibility in the inactive state, suggesting that the PH domain is readily available for the binding to the plasma membrane for activation. In contrast, these beta-strands became less exposed or more folded in the active form, which is favored for the dissociation of Akt from the membrane. The beginning alpha-helix J region and the C-terminal locus (T450-470P) of the regulatory domain showed less folded structures that probably enable substrate entry. Our data also revealed detailed conformational changes of Akt in the kinase domain due to activation, some of which may be attributed to the interaction of the basic residues with phosphorylation sites. Our H/D exchange results indicating the conformational status of Akt at different activation states provided new insight for the regulation of this critical protein involved in cell survival.

Accuracy of preoperative magnetic resonance imaging in assessing lymph node metastasis and myometrial invasion in patients with uterine cancer

OBJECTIVES

Our aim was to know preoperative magnetic resonance imaging (MRI) can accurately predict lymph node metastasis (LNM) and deep myometrial invasion (DMI, > or = 50%) in patients with uterine cancer.

METHODS

From January 1997 to December 2006, 99 patients who were diagnosed with uterine cancer and surgically staged at our institution were retrospectively analyzed. Preoperative clinicopathologic characteristics and MRI findings were reviewed and compared with LNM status and DMI observed in the final pathology.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV) for MRI in determination of pelvic LNM were 77.7%, 85.6%, 35.0%, and 94.7%, respectively. MRI failed to detect the presence of paraaortic LNM in all of the three patients with positive paraaortic lymph nodes. The sensitivity, specificity, PPV, and NPV for MRI in determining DMI were 46.6%, 84.5%, 35%, and 89.8%, respectively.

CONCLUSION

Preoperative evaluation of uterine cancer by MRI does not accurately predict the LNM and DMI.

Evaluation of Subchronic Inhalation Toxicity of Dimethyl Disulfide in Rats

This study was carried out to investigate the potential subchronic inhalation toxicity of dimethyl disulfide (DMDS) via whole-body exposure in F344 rats. Groups of 10 rats of each sex were exposed to DMDS vapor by whole-body exposure at concentrations of 0, 5, 25, or 125 ppm for 6 h/day, 5 days/wk for 13 wk. All the rats were sacrificed at the end of treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were examined. At 25 ppm, a decrease in the body weight gain, food intake, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and blood urea nitrogen (BUN) was observed in the males, but not in the females. However, at 125 ppm, a decrease in the body weight gain, food intake, and thymus weight and an increase in the weights of adrenal glands were observed in both genders. Serum biochemical investigations revealed a decrease in the AST, ALT, BUN, creatine phosphokinase (CPK), and triglyceride levels and an increase in the glucose level. In contrast, no treatment-related effects were observed in the 5 ppm group. The toxic potency of DMDS was slightly higher in males than that in females. In these experimental conditions, the target organ was not determined in rats. The no-observed-adverse-effect concentration (NOAEC) was found to be 5 ppm, 6 h/day for male rats and 25 ppm, 6 h/day for female rats.

Use of a real time continuous glucose monitoring system as a motivational device for poorly controlled type 2 diabetes

OBJECTIVE

The use of a real time continuous glucose monitoring system (RT-CGM) was studied as a behavior modification tool and the effectiveness of a RT-CGM in glucose control for patients with type 2 diabetes was determined.

METHODS

We conducted a prospective, open-label, randomized, controlled clinical trial in 65 patients with poorly controlled type 2 diabetes (8.0</=HbA1c</=10%) over a 3-month period. The intervention group was monitored monthly with a RT-CGM (three days at a time for 3 months) and the control group continued self-monitoring blood glucose (SMBG) at least four times a week for 3 months.

RESULTS

The HbA1c of the RT-CGM group was significantly reduced after 12 weeks compared with the SMBG group (9.1+/-1.0% to 8.0+/-1.2% vs. 8.7+/-0.7% to 8.3+/-1.1%, respectively; P=0.004). In the RT-CGM group, there was a significant reduction in total daily calorie intake, weight, body mass index (BMI), and postprandial glucose level, and a significant increase in total exercise time per week after 3 months.

CONCLUSIONS

We demonstrated that the RT-CGM was useful in modifying a patient's diet and exercise habits and could induce better glycemic control than SMBG for patients with type 2 diabetes.

Kurarinol, tyrosinase inhibitor isolated from the root of Sophora flavescens

It is well known that flavanones, sophoraflavanone G 1, kurarinone 2, and kurarinol 3, from the root of Sophora flavescens, have extremely strong tyrosinase inhibitory activity. This study delineates the principal pharmacological features of kurarinol 3 that lead to inhibition of the oxidation of l-tyrosine to melanin by mushroom tyrosinase (IC(50) of 100 nM). The inhibition kinetics analyses unveil that compounds 1 and 2 are noncompetitive inhibitors. However similar analysis shows kurarinol 3 to be a competitive inhibitor. Compounds 1 and 2 exhibited potent antibacterial activity with 10 microg/disk against Gram-positive bacteria, whereas kurarinol 3 did not ostend any antibacterial activity. Interestingly, kurarinol 3 inhibits production of melanin in S. bikiniensis without affecting the growth of microorganism. It is thus distinctly different from the other tyrosinase inhibitors 1 and 2. In addition, kurarinol 3 manifests relatively low cytotoxic activity (EC(50)>30 microM) compared to 1 and 2. To account for these observations, we conducted molecular modeling studies. These suggested that the lavandulyl group within 3 is instrumental in the interaction with the enzyme. More specifically, the terminal hydroxy function within the lavandulyl group is most important for optimal binding.

Sinonasal inverted papilloma: value of convoluted cerebriform pattern on MR imaging

BACKGROUND AND PURPOSE

A convoluted cerebriform pattern (CCP) has been reported as a valuable MR imaging feature of inverted papilloma (IP). The purpose of this study was to validate the usefulness of CCP for distinguishing IP from various malignant sinonasal tumors in a relatively large number of patients.

MATERIALS AND METHODS

We retrospectively reviewed MR images of 30 patients with IP and 128 patients with various malignant sinonasal tumors proved on histologic examination and compared the prevalence of a CCP between the 2 groups. In 8 patients with IP concomitant with squamous cell carcinoma, we also tried to find the MR features to help suggest coexistent malignancy.

RESULTS

A CCP was demonstrated in all 30 (100%) of the IPs and 17 (13%) of the 128 malignant sinonasal tumors on MR imaging. There was a significant statistical difference in the prevalence of a CCP between IP and malignant sinonasal tumors with the overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy 100%, 87%, 64%, 100%, and 89%, respectively. Of 8 IPs concomitant with squamous cell carcinoma, a focal loss of a CCP was demonstrated in 4 tumors, 3 of which also showed aggressive bone destruction with extrasinonasal extension on MR images.

CONCLUSION

Although a CCP is a reliable MR imaging feature of sinonasal IPs, it can also be seen in various malignant sinonasal tumors. A focal loss of a CCP might be a clue to the diagnosis of IPs concomitant with malignancy.

Biochemical and biological functions of docosahexaenoic acid in the nervous system: modulation by ethanol

Docosahexaenoic acid (DHA, 22:6n-3), an n-3 fatty acid highly concentrated in the central nervous system, is essential for proper neuronal and retinal function. While a high level of DHA is generally maintained in neuronal membranes, inadequate supply of n-3 fatty acid or ethanol exposure leads to a significant loss of DHA in neuronal cells. The roles of DHA in neuronal signaling have been emerging. In this review, biological, biochemical and molecular mechanisms supporting the essential function of DHA in neuronal survival and development are described in relation to n-3 fatty acid depleting conditions.

In vitro evaluation of poly(caporlactone) grafted dextran (PGD) nanoparticles with cancer cell

This study dealt with the preparation and characterization of coumarin-6 loaded poly(caprolactone) grafted dextran (PGD) nanoparticles (NPs) and evaluation of cellular uptake by using human gastric cancer cell line (SNU-638), in vitro. The potential application of these PGD NPs for sustained drug delivery was evaluated by the quantification and localization of the cellular uptake of fluorescent PGD NPs. Coumarin-6 loaded PGD NPs were prepared by a modified oil/water emulsion technique and characterized by various physico-chemical methods such as, laser light scattering for particle size and size distribution, atomic force microscopy (AFM), zeta-potential and spectrofluorometry to identify the release of fluorescent molecules from the NPs. SNU-638 was used to measure the cellular uptake of fluorescent PGD NPs. Confocal laser scanning microscopic images clearly showed the internalization of NPs by the SNU-638 cells. Cell viability was assessed by treating the SNU-638 cells with PGD NPs for 48 h. The results reveal, that these biodegradable polymeric NPs holds promise in biomedical field as a carrier.

Sinonasal organized hematoma: CT and MR imaging findings

BACKGROUND AND PURPOSE

Sinonasal organized hematoma (OH) is an uncommon, nonneoplastic benign condition that can be locally aggressive. The purpose of this work was to characterize the CT and MR imaging findings of sinonasal OH.

MATERIALS AND METHODS

CT (n = 11) and MR (n = 10) images of 12 patients (9 men and 3 women; mean age, 41 years; range, 12-76 years) with pathologically proved sinonasal OH were retrospectively reviewed. Particular attention was put on the location, shape, size, extent, internal architecture, and enhancement pattern of the lesion and associated sinus wall change.

RESULTS

The lesions were seen as an expansile (n = 9) or nonexpansile (n = 3) mass, ranging in size from 2.2 to 6.0 cm (mean, 4.2 cm), primarily involving the maxillary sinus (n = 11) or nasal cavity (n = 1) unilaterally. The ipsilateral nasal cavity was also involved in 9 of 11 maxillary sinus lesions. Smooth sinus wall erosion other than the medial maxillary sinus wall was noted in 8 lesions. The internal architecture was best displayed on T2-weighted MR images on which all of the lesions were seen as a mixture of marked heterogeneous hypointensity and isointensity, surrounded by a hypointense peripheral rim, reflecting histologic heterogeneity of the lesion composed of hemorrhage, fibrosis, and neovascularization. Marked irregular nodular, papillary, or frondlike enhancement at the areas of neovascularization was also a typical finding seen in all of the lesions.

CONCLUSION

An expansile soft tissue mass, smooth sinus wall erosion, marked heterogeneous signal intensity with a hypointense peripheral rim on T2-weighted MR images, and marked irregular nodular, papillary, or frondlike enhancement are characteristic CT and MR imaging findings of sinonasal OH.

Serum retinol-binding protein 4 levels are elevated in non-alcoholic fatty liver disease

OBJECTIVE

Retinol-binding protein 4 (RBP4) is a recently identified adipokine that is elevated in the serum in several insulin-resistant states. We investigated the relationship between non-alcoholic fatty liver disease (NAFLD) and serum RBP4 in nondiabetic adults.

METHODS

One hundred and fifty-nine nondiabetic, non-alcoholic subjects (95 males and 64 females) participated in this study. Division of subjects into a NAFLD group (n = 73; 45 males and 28 females) or a normal group (n = 86; 50 males and 36 females) was based on the presence of fatty liver disease determined by sonography.

RESULTS

Serum RBP4 levels in the NAFLD group were significantly higher than those in the normal group (62.8 +/- 16.0 mg/l vs. 51.7 +/- 14.6 mg/l, P < 0.0001). Multiple logistic regression analysis revealed that the RBP4 level was an independent factor associated with NAFLD (P = 0.0042). In addition, serum RBP4 levels were positively correlated with serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltranspeptidase (GGT) levels. The significant association between serum RBP4 and GGT levels remained even after adjusting for age, gender, body mass index, the homeostasis model of assessment (HOMA) value and the presence of NAFLD (r = 0.3097, P = 0.0002).

CONCLUSION

Serum RBP4 levels are significantly associated with NAFLD and liver enzymes.

Outcomes of surgical management of total colonic aganglionosis

PURPOSE

The purpose of this study was to assess the long-term clinical outcomes and bowel function of patients with total colonic aganglionosis (TCA) after surgery.

METHODS

The hospital records of 17 TCA patients treated surgically during 1985 to 2004 were reviewed. Long-term follow-up was done by telephone interviews with the parents.

RESULTS

Primary enterostomy was performed in 13 (76%) patients. In three (17%) patients, TCA was not suspected initially. They underwent conservative surgery primarily, which required a second operation soon after. One had transverse colectomy with ileostomy. By pathologic review, nine (53%) patients had small bowel involvement of aganglionosis. Six (35%) patients died before corrective surgery. They all had extensive small bowel involvement. Among 11 patients who had a corrective operation, 10 were treated with Martin's procedure. Long-term (mean 74 months) follow-up was available in seven patients, and the mean weight-for-age percentiles was 27.1% (range 5-50%), the frequency of defecation was three to five times a day in four patients (57%), one or two times a day in two patients (28%), and more than five times a day in one patient (15%).

CONCLUSIONS

TCA is difficult to diagnose; but once it is diagnosed correctly and treated by corrective surgery, outcomes seem promising. Martin's operation brought about a good outcome and enabled patients to have acceptable bowel habits. The prognosis is highly dependent on the extent of aganglionosis.

Effect of kimchi powder level and drying methods on quality characteristics of breakfast sausage

This study was conducted to determine the effect of the addition of kimchi powder on the quality characteristics of meat batter and breakfast sausage. Breakfast sausages were supplemented with freeze dried kimchi powder (FKP) or hot air dried kimchi powder (HKP) at levels of 1% (FKP-1 and HKP-1) or 2% (FKP-2 and HKP-2). The emulsion stability, cooking yield, and apparent viscosity in meat batters improved with increments of kimchi powder (p<0.05). Increased levels of kimchi powder in breakfast sausage decreased the L(∗) value, pH, and springiness, and increased the a(∗) value, b(∗) value, hardness, chewiness, and gumminess (p<0.05). Sensory evaluations indicated that a higher overall acceptability was attained when the kimchi powder was added to breakfast sausage at a level of 2%.

Display of heterologous proteins on the surface of Lactococcus lactis using the H and W domain of PrtB from Lactobacillus delburueckii subsp. bulgaricus as an anchoring matrix

AIMS

The aim of this study was to develop a cell-surface display system for foreign antigens on the surface of a Lactococcus lactis strain using an H and W domain of PrtB from Lactobacillus delburueckii subsp. bulgaricus as an anchoring matrix.

METHODS AND RESULTS

To construct a cell-surface display pACL1 vector, a derivative of pSECE1 vector, we amplified the H and W domain of the cell-surface proteinase Prt B from Lact. bulgaricus using specific primers and then cloned it into a site downstream of the secretion signal sequence in the pSECE1 vector. The new system, designed for cell-surface display of recombinant proteins on L. lactis, was evaluated by the expression and display of the FliC protein of Salmonella enterica serovar Enteritidis as a reporter gene (pALC1:FliC). The expression of the FliC protein by the transformed cells was analysed by Western blot analysis, and the localization of FliC on the cell surface was confirmed by immunofluorescence microscopy and flow cytometry analysis. A specific band corresponding in size (approx. 110 kDa) to FliC plus the anchor residues was detected by anti-FliC antibody in the cell extract of L. lactis H61 harbouring pALC1:FliC, but not L. lactis H61 harbouring pALC1. In addition, flow cytometry and immunofluorescence microscopy revealed FliC-specific positive signals and a significant increase of fluorescence, respectively, in cells harbouring pALC1:FliC compared with that in control cells harbouring the parental pALC1 plasmid. These findings demonstrated that FliC was successfully displayed on the cell surface by the anchor domain of PrtB.

CONCLUSIONS

A pALC1 vector using the H and W domain of PrtB from Lact. bulgaricus as an anchoring matrix can be used to successfully display the FliC protein on the surface of L. lactis.

SIGNIFICANCE AND IMPACT OF THE STUDY

This novel way of displaying heterologous proteins on the cell surface of L. lactis using the PrtB anchor domain should prove useful for the delivery of antigens and other proteins.

Subthalamic lesion on MR imaging in a patient with nonketotic hyperglycemia-induced hemiballism

SUMMARY

Hemiballism with corresponding striatal T1 hyperintensity on MR imaging has occasionally been reported in patients with nonketotic hyperglycemia. However, the subthalamic nucleus lesion, which is believed to be pathogenetically related to hemiballism, is rarely documented in a living patient with nonketotic hyperglycemia. We describe a patient with nonketotic hyperglycemia-induced hemiballism, whose responsible lesion (ie, the subthalamus) was demonstrated by MR imaging.

Effects of tert-butyl acetate on maternal toxicity and embryo-fetal development in Sprague-Dawley rats

This study investigated the potential adverse effects of tert-butyl acetate (TBAc) on maternal toxicity and embryo-fetal development after maternal exposure of pregnant rats from gestational days 6 through 19. TBAc was administered to pregnant rats by gavage at 0, 400, 800, and 1,600 mg/kg/day. All dams were subjected to a Caesarean section on day 20 of gestation, and their fetuses were examined for any morphological abnormalities. At 1,600 mg/kg, maternal toxicity manifested as increases in the incidence of clinical signs and death, lower body weight gain and food intake, increases in the weights of adrenal glands and liver, and a decrease in thymus weight. Developmental toxicity included a decrease in fetal weight, an increase in the incidence of skeletal variation, and a delay in fetal ossification. At 800 mg/kg, only a minimal developmental toxicity, including an increase in the incidence of skeletal variation and a delay in fetal ossification, were observed. In contrast, no adverse maternal or developmental effects were observed at 400 mg/kg. These results show that a 14-day repeated oral dose of TBAc is embryotoxic at a maternally toxic dose (i.e., 1,600 mg/kg/day) and is minimally embryotoxic at a nonmaternally toxic dose (i.e., 800 mg/kg/day) in rats. However, no evidence for the teratogenicity of TBAc was noted in rats. It is concluded that the developmental findings observed in the present study are secondary effects to maternal toxicity. Under these experimental conditions, the no-observed-adverse-effect level of TBAc is considered to be 800 mg/kg/day for dams and 400 mg/kg/day for embryo-fetal development.