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Selected AbstractsPhotoepilation Results of Axillary Hair in Dark-Skinned Patients by IPL: A Comparison Between Different Wavelength and Pulse WidthDERMATOLOGIC SURGERY, Issue 2 2006JONG HEE LEE MD BACKGROUND Recently, intense pulsed light (IPL) sources have been shown to provide long-term hair removal. OBJECTIVE This study examined the photoepilatory effects of different wavelengths and pulse width application in the same device and compared their efficiencies in Asian skin. METHODS Twenty-eight Korean women were treated using HR (600,950 nm filter) and 27 using HR-D (645,950 nm filter) in the axillar area. Four treatments were carried out at intervals of 4 to 6 weeks; follow-ups were conducted 8 months after the last treatment. Mean energy settings were 14.9±2.0 J/cm2 for HR and 17.1±0.6 J/cm2 for HR-D. Longer pulse widths were applied in case of HR-D treatment. Hair counts and photographic evaluation of skin sites were made at baseline and at the last follow-up. Final overall evaluations were performed by patients and clinicians. RESULTS Average clearances of 52.8% and 83.4% were achieved by HR and HR-D, respectively. No significant adverse effects were reported after HR-D treatment. One case each of hypopigmentation and hyperpigmentation was reported for HR. CONCLUSION An IPL source by removing 45 nm of the emitted spectra and applying longer pulse width was found to provide a safer and more effective means of photoepilation in Asian patients. [source] Temporal Variability of Ventricular Arrhythmias in Boxer Dogs with Arrhythmogenic Right Ventricular CardiomyopathyJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2009B.A. Scansen Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is prevalent in the Boxer. There is little information on the temporal variability of ventricular arrhythmias within affected dogs. Objective: To evaluate ambulatory electrocardiograms (AECG) from Boxers with ARVC for hourly variation in premature ventricular complexes (PVC) and heart rate (HR). Animals: One hundred and sixty-two Boxer dogs with ARVC. Methods: Retrospective, observational study of 1,181 AECGs collected from Boxer dogs at The Ohio State University from 1997 to 2004 was evaluated. The proportion of depolarizations that were PVCs was compared across each hour of the day, during six 4-hour periods of day, to the time after AECG application, and to the maximum and minimum HR. Results: A lower proportion of PVCs was noted during early morning (midnight to 0400 hours) as compared with the morning (0800,1200 hours) and late (1600,2000 hours) afternoon (P= .012). There was no increase in PVC proportion in the 1st hour after AECG application as compared with all other hours of the day (P= .06). There was poor correlation between maximum (,= 0.19) and minimum (,= 0.12) HR and PVC proportion. Conclusions and Clinical Importance: The likelihood of PVC occurrence in Boxer dogs with ARVC was relatively constant throughout the day, although slightly greater during the hours of 0800,1200 and 1600,2000. A biologically important correlation with HR was not apparent. The role of autonomic activity in the modulation of electrical instability in the Boxer with ARVC requires further study. [source] Accumulation of chlorophyll catabolites photosensitizes the hypersensitive response elicited by Pseudomonas syringae in ArabidopsisNEW PHYTOLOGIST, Issue 1 2010Luis A. J. Mur Summary ,The staygreen (SGR) gene encodes a chloroplast-targeted protein which promotes chlorophyll degradation via disruption of light-harvesting complexes (LHCs). ,Over-expression of SGR in Arabidopsis (SGR-OX) in a Columbia-0 (Col-0) background caused spontaneous necrotic flecking. To relate this to the hypersensitive response (HR), Col-0, SGR-OX and RNAi SGR (SGRi) lines were challenged with Pseudomonas syringae pv tomato (Pst) encoding the avirulence gene avrRpm1. Increased and decreased SGR expression, respectively, accelerated and suppressed the kinetics of HR-cell death. In Col-0, SGR transcript increased at 6 h after inoculation (hai) when tissue electrolyte leakage indicated the initiation of cell death. ,Excitation of the chlorophyll catabolite pheophorbide (Pheide) leads to the formation of toxic singlet oxygen (1O2). Pheide was first detected at 6 hai with Pst avrRpm1 and was linked to 1O2 generation and correlated with reduced Pheide a oxygenase (PaO) protein concentrations. The maximum quantum efficiency of photosystem II (Fv/Fm), quantum yield of electron transfer at photosystem II (,PSII), and photochemical quenching (qP) decreased at 6 hai in Col-0 but not in SGRi. Disruption of photosynthetic electron flow will cause light-dependent H2O2 generation at 6 hai. ,We conclude that disruption of LHCs, possibly influenced by SGR, and absence of PaO produce phototoxic chlorophyll catabolites and oxidative stress leading to the HR. [source] Local early induced resistance of plants as the first line of defence against bacteria,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2003Zoltán Klement Abstract This paper is an overview of a non-specific local early induced resistance (EIR) mechanism, distinct from the incompatible-specific hypersensitive reaction (HR). We have shown that the local induced resistance (LIR) described earlier is not a single and uniform response to pathogen infection, because an early (EIR) and a late form can be distinguished. EIR operates from 3,6,h post-inoculation (hpi) until about 20,hpi, and is inhibited by a short heat-shock or the eukaryotic protein synthesis inhibitor, cycloheximide. In contrast, LIR, which corresponds to the induced resistance forms discovered earlier, requires more time (about 24,h) and intensive illumination to develop, and is effective for a longer period. EIR develops parallel with HR and is sometimes able to prevent it when the induction time of HR is longer than the time required for the development of EIR. It seems that EIR inhibits the metabolism of bacteria and the activity of hrp genes which otherwise are required for the induction of HR. In a compatible host,pathogen relationship the effect of EIR fails to take place. The rapid development of EIR is greatly influenced by temperature and the physiological state of the plant. EIR activates the accumulation of hydrogen peroxide at the bacterial attachment, expressing new peroxidase isoenzymes in the initiated plant tissue. It seems that this is a native general local defence mechanism which can localise foreign organisms even at the penetration site. © 2003 Society of Chemical Industry [source] Proteomic analysis of S-nitrosylated proteins in Arabidopsis thaliana undergoing hypersensitive responsePROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 7 2008Maria C. Romero-Puertas Abstract Nitric oxide (NO) has a fundamental role in the plant hypersensitive disease resistance response (HR), and S-nitrosylation is emerging as an important mechanism for the transduction of its bioactivity. A key step toward elucidating the mechanisms by which NO functions during the HR is the identification of the proteins that are subjected to this PTM. By using a proteomic approach involving 2-DE and MS we characterized, for the first time, changes in S-nitrosylated proteins in Arabidopsis thaliana undergoing HR. The 16 S-nitrosylated proteins identified are mostly enzymes serving intermediary metabolism, signaling and antioxidant defense. The study of the effects of S-nitrosylation on the activity of the identified proteins and its role during the execution of the disease resistance response will help to understand S-nitrosylation function and significance in plants. [source] The Effect of Intracavernous Injection of Adipose Tissue-Derived Stem Cells on Hyperlipidemia-Associated Erectile Dysfunction in a Rat ModelTHE JOURNAL OF SEXUAL MEDICINE, Issue 4pt1 2010Yun-Ching Huang MD ABSTRACT Introduction., Hyperlipidemia has been associated with erectile dysfunction (ED) via damage to the cavernous endothelium and nerves. Adipose tissue-derived stem cells (ADSC) have been shown to differentiate into endothelial cells and secrete vasculotrophic and neurotrophic factors. Aim., To assess whether ADSC have therapeutic effects on hyperlipidemia-associated ED. Methods., Twenty-eight male rats were induced to develop hyperlipidemia with a high-fat diet (hyperlipidemic rats, HR). Ten additional male rats were fed a normal diet to serve as controls (normal rats, NR). Five months later, all rats were subjected to ADSC isolation from paragonadal fat. The cells were cultured for 1 week, labeled with 5-ethynyl-2,-deoxyuridine (EdU), and then injected autologously into the corpus cavernosum of 18 HR. The remaining 10 HR rats were injected with phosphate buffered saline (PBS). At 2 and 14 days post-transplantation, four rats in the HR + ADSC group were sacrificed for tracking of the transplanted cells. At 28 days post-transplantation, all remaining rats were analyzed for serum biochemistry, erectile function, and penile histology. Main Outcome Measures., Erectile function was assessed by intracavernous pressure (ICP) measurement during electrostimulation of the cavernous nerve. Cavernous nerves, endothelium, and smooth muscle were assessed by immunohistochemistry. Results., Serum total cholesterol and low-density lipoprotein levels were significantly higher in HR than in NR. High-density lipoprotein level was significantly lower in HR than in NR. Mean ICP/mean arterial pressure ratio was significantly lower in HR + PBS than in NR + PBS or HR + ADSC. Neuronal nitric oxide synthase (nNOS)-positive nerve fibers and endothelial cells were fewer in HR + PBS than in HR + ADSC. Smooth muscle content was significantly higher in both HR groups than in NR. Conclusions., Hyperlipidemia is associated with abnormalities in both the nerves and endothelium. Treatment with ADSC ameliorates these adverse effects and holds promise as a potential new therapy for ED. Huang Y-C, Ning H, Shindel AW, Fandel TM, Lin G, Harraz AM, Lue TF, and Lin C-S. The effect of intracavernous injection of adipose tissue-derived stem cells on hyperlipidemia-associated erectile dysfunction in a rat model. J Sex Med 2010;7:1391,1400. [source] The chloroplast protein RPH1 plays a role in the immune response of Arabidopsis to Phytophthora brassicaeTHE PLANT JOURNAL, Issue 2 2009Khaoula Belhaj Summary Plant immune responses to pathogens are often associated with enhanced production of reactive oxygen species (ROS), known as the oxidative burst, and with rapid hypersensitive host cell death (the hypersensitive response, HR) at sites of attempted infection. It is generally accepted that the oxidative burst acts as a promotive signal for HR, and that HR is highly correlated with efficient disease resistance. We have identified the Arabidopsis mutant rph1 (resistance to Phytophthora 1), which is susceptible to the oomycete pathogen Phytophthora brassicae despite rapid induction of HR. The susceptibility of rph1 was specific for P. brassicae and coincided with a reduced oxidative burst, a runaway cell-death response, and failure to properly activate the expression of defence-related genes. From these results, we conclude that, in the immune response to P. brassicae, (i) HR is not sufficient to stop the pathogen, (ii) HR initiation can occur in the absence of a major oxidative burst, (iii) the oxidative burst plays a role in limiting the spread of cell death, and (iv) RPH1 is a positive regulator of the P. brassicae -induced oxidative burst and enhanced expression of defence-related genes. Surprisingly, RPH1 encodes an evolutionary highly conserved chloroplast protein, indicating a function of this organelle in activation of a subset of immune reactions in response to P. brassicae. The disease resistance-related role of RPH1 was not limited to the Arabidopsis model system. Silencing of the potato homolog StRPH1 in a resistant potato cultivar caused susceptibility to the late blight pathogen Phytophthora infestans. [source] Mechanism of cell death and disease resistance induction by transgenic expression of bacterio-opsinTHE PLANT JOURNAL, Issue 5 2002Dominique Pontier Summary One of the earliest signal transduction events that trigger the hypersensitive response (HR) of plants against pathogen attack is thought to be an alteration of proton flux across the plasma membrane (PM). However, no direct genetic evidence for the involvement of PM-localised proton channels or pumps in the induction of this response has been reported. We previously showed that expression of the bacterial proton pump bacterio-opsin (bO) in transgenic plants resulted in the spontaneous activation of the HR. Here we show that the bO protein is likely localised to the PM in transgenic tobacco plants. Furthermore, mutational analysis shows that induction of the HR by bO expression is dependent upon the capability of bO to translocate protons. Although bO functions as a light-driven proton pump in Halobacteria when assembled with retinal, we also show by mutational analysis that this chromophore binding is unnecessary for its in planta activity. Taken together, our results suggest that expression of bO in plants leads to the insertion of a passive proton channel into the PM. The activity of this channel in the PM results in spontaneous activation of cell death and HR-associated phenotypes including enhanced resistance to a broad spectrum of plant pathogens. Our work provides direct molecular evidence to support a working model in which alterations in ionic homeostasis at the level of the PM may work as one of the critical steps in the signalling pathway for the activation of the HR. [source] Role of hydrogen sulphide in haemorrhagic shock in the rat: protective effect of inhibitors of hydrogen sulphide biosynthesisBRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2004Ying-Yuan Pamela Mok Haemorrhagic shock (60 min) in the anaesthetized rat resulted in a prolonged fall in the mean arterial blood pressure (MAP) and heart rate (HR). Pre-treatment (30 min before shock) or post-treatment (60 min after shock) with inhibitors of cystathionine , lyase (CSE; converts cysteine into hydrogen sulphide (H2S)), dl-propargylglycine or , -cyanoalanine (50 mg kg,1, i.v.), or glibenclamide (40 mg kg,1, i.p.), produced a rapid, partial restoration in MAP and HR. Neither saline nor DMSO affected MAP or HR. Plasma H2S concentration was elevated 60 min after blood withdrawal (37.5±1.3 ,m, n=18 c.f. 28.9±1.4 ,m, n=15, P<0.05). The conversion of cysteine to H2S by liver (but not kidney) homogenates prepared from animals killed 60 min after withdrawal of blood was significantly increased (52.1±1.6 c.f. 39.8±4.1 nmol mg protein,1, n=8, P<0.05), as was liver CSE mRNA (2.7 ×). Both PAG (IC50, 55.0±3.2 ,m) and BCA (IC50, 6.5±1.2 ,m) inhibited liver H2S synthesizing activity in vitro. Pre-treatment of animals with PAG or BCA (50 mg kg,1, i.p.) but not glibenclamide (40 mg kg,1, i.p., KATP channel inhibitor) abolished the rise in plasma H2S in animals exposed to 60 min haemorrhagic shock and prevented the augmented biosynthesis of H2S from cysteine in liver. These results demonstrate that H2S plays a role in haemorrhagic shock in the rat. CSE inhibitors may provide a novel approach to the treatment of haemorrhagic shock. British Journal of Pharmacology (2004) 143, 881,889. doi:10.1038/sj.bjp.0706014 [source] Relevance of the C-terminal Arg-Phe sequence in ,2 -melanocyte-stimulating hormone (,2 -MSH) for inducing cardiovascular effects in conscious ratsBRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2000M J M A Nijsen The cardiovascular effects by ,2 -melanocyte-stimulating hormone (,2 -MSH) are probably not due to any of the well-known melanocortin subtype receptors. We hypothesize that the receptor for Phe-Met-Arg-Phe-amide (FMRFa) or Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-amide (neuropeptide FF; NPFFa), other Arg-Phe containing peptides, is the candidate receptor. Therefore, we studied various Arg-Phe containing peptides to compare their haemodynamic profile with that of ,2 -MSH(6,12), the most potent fragment of ,2 -MSH. Mean arterial pressure (MAP) and heart rate (HR) changes were measured in conscious rats after intravenous administration of ,2 -MSH related peptides. Phe-Arg-Trp-Asp-Arg-Phe-Gly (,2 -MSH(6,12)), FMRFa, NPFFa, Met-enkephalin-Arg-Phe-amide (MERFa), Arg-Phe-amide (RFa), acetyl-Phe-norLeu-Arg-Phe-amide (acFnLRFa) and desamino-Tyr-Phe-norLeu-Arg-Phe-amide (daYFnLRFa) caused a dose-dependent increase in MAP and HR. ,2 -MSH(6,12) showed the most potent cardiovascular effects (ED50=12 nmol kg,1 for ,MAP; 7 nmol kg,1 for ,HR), as compared to the other Arg-Phe containing peptides (ED50=177,292 nmol kg,1 for ,MAP; 130,260 nmol kg,1 for ,HR). Peptides, which lack the C-terminal Arg-Phe sequence (Lys-Tyr-Val-Met-Gly-His-Phe-Arg-Trp-Asp-Arg-Pro-Gly (,2 -pro11 -MSH), desamino-Tyr-Phe-norLeu-Arg-[L-1,2,3,4 tetrahydroisoquinoline-3-carboxylic acid]-amide (daYFnLR[TIC]a) and Met-enkephalin (ME)), were devoid of cardiovascular actions. The results indicate that the baroreceptor reflex-mediated reduction of tonic sympathetic activity due to pressor effects is inhibited by ,2 -MSH(6,12) and that its cardiovascular effects are dependent on the presence of a C-terminal Arg-Phe sequence. It is suggested that the FMRFa/NPFFa receptor is the likely candidate receptor, involved in these cardiovascular effects. British Journal of Pharmacology (2000) 131, 1468,1474; doi:10.1038/sj.bjp.0703709 [source] Nonnutritive sucking: One of the major determinants of filial loveDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2006David Val-Laillet Abstract The present study investigated the rewarding effects of nonnutritive sucking on the development of a filial preference. Two experiments were conducted to test whether nonnutritive visceral and oral stimuli have reinforcing properties independent from each other or act in synergy. Lambs could interact freely with their dam but were deprived of suckling by covering the udder for the first 12 hr. In Experiment 1, suckling was prevented and replaced by human giving, in the presence of the mother, either a bottle of water (B5 and B2.5: 5% or 2.5% birth weight, BW, divided into seven portions over 12 hr) or water via tube-feeding (I5 and I2.5: 5% or 2.5% BW, also divided into seven portions over 12 hr). During a two-choice test performed at 12 hr after birth, only B5 and I5 lambs preferred their mother to an alien ewe however, B5 were faster at choosing their mother at the beginning of the test. B2.5 and I2.5 lambs made a random choice. In Experiment 2, suckling was prevented and replaced by human giving, in the presence of the mother, either a bottle of water (B2.5: 2.5% BW, divided into seven portions over 12 hr) or water via tube-feeding (I10 and I2.5: 10% or 2.5% BW, also divided into seven portions over 12 hr). During a two-choice test at 12 hr, tube-fed lambs (I10 and I2.5) preferred their mother to a human. B2.5 lambs were equally attracted to both partners and spent more time near the human than lambs from the other groups. In a test of reactivity to a human performed on neonates isolated from their mother, B2.5 lambs explored the human much more than the other lambs. The presence of the human had soothing properties in B2.5 lambs and once the human left, they were the only lambs displaying enhanced vocal and locomotor activity. In these experiments, nonnutritive gastrointestinal stimuli induced a preference for the mother whereas nonnutritive sucking led to a strong positive relationship with the human. These results suggest that when lambs suckle their dam, the development of filial bonding is facilitated through the combined effects of oral and gastrointestinal stimuli. © 2006 Wiley Periodicals, Inc. Dev Psyshobiol 48: 220,232, 2006. [source] Alterations in gene expression profiles and the DNA-damage response in ionizing radiation-exposed TK6 cells,,ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2-3 2005Gregory S. Akerman Abstract Identifying genes that are differentially expressed in response to DNA damage may help elucidate markers for genetic damage and provide insight into the cellular responses to specific genotoxic agents. We utilized cDNA microarrays to develop gene expression profiles for ionizing radiation-exposed human lymphoblastoid TK6 cells. In order to relate changes in the expression profiles to biological responses, the effects of ionizing radiation on cell viability, cloning efficiency, and micronucleus formation were measured. TK6 cells were exposed to 0.5, 1, 5, 10, and 20 Gy ionizing radiation and cultured for 4 or 24 hr. A significant (P < 0.0001) decrease in cloning efficiency was observed at all doses at 4 and 24 hr after exposure. Flow cytometry revealed significant decreases in cell viability at 24 hr in cells exposed to 5 (P < 0.001), 10 (P < 0.0001), and 20 Gy (P < 0.0001). An increase in micronucleus frequency occurred at both 4 and 24 hr at 0.5 and 1 Gy; however, insufficient binucleated cells were present for analysis at the higher doses. Gene expression profiles were developed from mRNA isolated from cells exposed to 5, 10, and 20 Gy using a 350 gene human cDNA array platform. Overall, more genes were differentially expressed at 24-hr than at the 4-hr time point. The genes upregulated (> 1.5-fold) or downregulated (< 0.67-fold) at 4 hr were those primarily involved in the cessation of the cell cycle, cellular detoxification pathways, DNA repair, and apoptosis. At 24 hr, glutathione-associated genes were induced in addition to genes involved in apoptosis. Genes involved in cell cycle progression and mitosis were downregulated at 24 hr. Real-time quantitative PCR was used to confirm the microarray results and to evaluate expression levels of selected genes at the low doses (0.5 and 1.0 Gy). The expression profiles reflect the cellular and molecular responses to ionizing radiation related to the recognition of DNA damage, a halt in progression through the cell cycle, activation of DNA-repair pathways, and the promotion of apoptosis. Environ. Mol. Mutagen., 2005. Published 2005 Wiley-Liss, Inc. [source] Factors affecting biodegradation of 2-chlorophenol by Alcaligenes sp. in aerobic reactorsENVIRONMENTAL TOXICOLOGY, Issue 4 2001A. Gallego Abstract The influence of variations in carbon source concentration, cell inocula, pH, presence of other substrates, and other organisms on the biodegradation of 2-chlorophenol (2-CP) was studied for Alcaligenes sp. isolated from natural sources. Assays of biodegradation were performed in batch and continuous-flow fluidized-bed aerobic reactors. Evaluation of biodegradation was performed by determining total phenols, chemical oxygen demand (COD), and 2-CP by ultraviolet (UV) spectrophotometry. Measurement of microbial growth was carried out by the plate count method. Bioassays of acute toxicity were performed to evaluate detoxification by using Daphnia magna. Results obtained show that under batch conditions with initial inocula of 106 cells/mL the strain grew exponentially with 100, 200, and 300 mg/L of 2-CP within 48 hr. A lag period was observed with low cell density inocula (105 cells/mL). The strain showed marked delay in the biodegradation of 2-CP at pH 5. Removal of target substrate from mixtures containing other carbon sources demonstrated the possibility of concurrent growth. Mineralization of 2-CP was assessed by gas chromatography carried out at the end of the batch assays and at the exit of the continuous-flow reactor. The presence of other organisms (bacteria, rotifers, ciliate, and algae) that developed in the fluidized-bed reactor did not affect the efficacy of the biodegradation of 2-CP. The removal of 2-CP in the two assayed systems was over 97% in all cases. Toxicity was not detected at the exit of the continuous reactor. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 306,313, 2001 [source] Identifying sequence variants in the human mitochondrial genome using high-resolution melt (HRM) profiling,HUMAN MUTATION, Issue 6 2009Steven F. Dobrowolski Abstract Identifying mitochondrial DNA (mtDNA) sequence variants in human diseases is complicated. Many pathological mutations are heteroplasmic, with the mutant allele represented at highly variable percentages. High-resolution melt (HRM or HRMA) profiling was applied to comprehensive assessment of the mitochondrial genome and targeted assessment of recognized pathological mutations. The assay panel providing comprehensive coverage of the mitochondrial genome utilizes 36 overlapping fragments (301,658,bp) that employ a common PCR protocol. The comprehensive assay identified heteroplasmic mutation in 33 out of 33 patient specimens tested. Allele fraction among the specimens ranged from 1 to 100%. The comprehensive assay panel was also used to assess 125 mtDNA specimens from healthy donors, which identified 431 unique sequence variants. Utilizing the comprehensive mtDNA panel, the mitochondrial genome of a patient specimen may be assessed in less than 1 day using a single 384-well plate or two 96-well plates. Specific assays were used to identify the myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) mutation m.3243A>G, myoclonus epilepsy, ragged red fibers (MERRF) mutation m.8344A>G, and m.1555A>G associated with aminoglycoside hearing loss. These assays employ a calibrated, amplicon-based strategy that is exceedingly simple in design, utilization, and interpretation, yet provides sensitivity to detect variants at and below 10% heteroplasmy. Turnaround time for the genotyping tests is about 1,hr. Hum Mutat 30,1,8, 2009. © 2009 Wiley-Liss, Inc. [source] Induction of 150-kDa adenosine deaminase that acts on RNA (ADAR)-1 gene expression in normal T lymphocytes by anti-CD3-, and anti-CD28IMMUNOLOGY, Issue 4 2007Dama Laxminarayana Summary We and other investigators have demonstrated up-regulation of the expression of the RNA-editing gene 150-kDa adenosine deaminase that acts on RNA (ADAR1) in systemic lupus erythematosus (SLE) T cells and B cells, peripheral blood mononuclear cells (PBMC), natural killer (NK) cells. The presence of a small proportion of activated T cells is the hallmark of SLE. Therefore, it was hypothesized that 150-kDa ADAR1 gene expression is induced by the physiological activation of T cells. To examine this hypothesis, normal T cells were activated by anti-CD3-, plus anti-CD28 for various time periods from 0 to 48 hr. The expression of 110-kDa and 150-kDa ADAR1, and interleukin (IL)-2 and ,-actin gene transcripts was analysed. An approximately fourfold increase in 150-kDa ADAR1 gene expression was observed in activated T cells. ADAR2 gene transcripts are substrates for ADAR1 and ADAR2 enzymes. Therefore, we assessed the role of the 150-kDa ADAR enzyme in editing of ADAR2 gene transcripts. In activated T cells, site-selective editing of the ,2 site was observed. Previous studies indicate that this site is predominantly edited by ADAR1. In addition to this, novel editing sites at base positions ,56, ,48, ,45, ,28, ,19, ,15, +46 and +69 were identified in activated T cells. On the basis of these results, it is proposed that 150-kDa ADAR1 gene expression is selectively induced in T cells by anti-CD3-, and anti-CD28 stimulation and that it may play a role in site-selective editing of gene transcripts and in altering the functions of several gene products of T cells during activation and proliferation. [source] The effect of GHRH antagonists on human glioblastomas and their mechanism of action,INTERNATIONAL JOURNAL OF CANCER, Issue 10 2010Eva Pozsgai Abstract The effects of new growth hormone-releasing hormone (GHRH) antagonists JMR-132 and MIA-602 and their mechanism of action were investigated on 2 human glioblastoma cell lines, DBTRG-05 and U-87MG, in vitro and in vivo. GHRH receptors and their main splice variant, SV1 were found on both cell lines. After treatment with JMR-132 or MIA-602, the cell viability decreased significantly. A major decrease in the levels of phospho-Akt, phospho-GSK3, and phosho-ERK 1/2 was detected at 5 and 10 min following treatment with the GHRH antagonists, whereas elevated levels of phospho-p38 were observed at 24 hr. The expression of caspase-3 and poly(ADP-ribose) (PARP), as the downstream executioners of apoptosis were found to be significantly elevated after treatment. Following treatment of the glioblastoma cells with GHRH antagonists, nuclear translocation of apoptosis inducing factor (AIF) and Endonuclease G (Endo G) and the mitochondrial release of cytochrome c (cyt c) were detected, indicating that the cells were undergoing apoptosis. In cells treated with GHRH antagonists, the collapse of the mitochondrial membrane potential was shown with fluorescence microscopy and JC-1 membrane potential sensitive dye. There were no significant differences between results obtained in DBTRG-05 or U-87MG cell lines. After treatment with MIA-602 and JMR-132, the reduction rate in the growth of DBTRG-05 glioblastoma, xenografted into nude mice, was significant and tumor doubling time was also significantly extended when compared with controls. Our study demonstrates that GHRH antagonists induce apoptosis through key proapoptotic pathways and shows the efficacy of MIA-602 for experimental treatment of glioblastoma. [source] Angiopoietin-2 expression in breast cancer correlates with lymph node invasion and short survivalINTERNATIONAL JOURNAL OF CANCER, Issue 4 2003Christian Sfiligoi Abstract Angiogenic factors produced by tumor cells are essential for tumor growth and metastasis. In our study, the expression of Angiopoietin-1 (ANG1) and Angiopoietin-2 (ANG2) mRNA in archival human breast cancer tumor samples and in 6 breast cancer cell lines was investigated. Total RNA from biopsies of 38 breast cancer patients was extracted and ANG1 and ANG2 mRNA expression was measured by means of quantitative real-time RT-PCR (Taqman®). Matching data with available clinicopathologic and biochemical data revealed a significant association between ANG2 expression and axillary lymph node invasion. Univariate and multivariate survival analysis, by means of Kaplan-Meier method and Cox's proportional hazards model, showed significant and independent association between ANG2 mRNA level and both disease-free (p < 0.0001) and overall survival (p < 0.0003). An important fact is that, notwithstanding the small number of cases examined, this association was confirmed also in the group of lymph node-negative patients (DFS, p < 0.003; OS, p < 0.020). Immunohistochemical analysis demonstrated that Ang2 is expressed by both tumor cells and endothelial elements. Expression in tumor cells was confirmed by studying a panel of human breast carcinoma cell lines in culture by RT-PCR. In ZR75.1 and T47D cells, expression of ANG2 mRNA was increased up to 10-fold by treatment with estrogen within 24 hr. Although preliminary, these data suggest a possible role of ANG2 as a prognostic factor for primary breast cancer. © 2002 Wiley-Liss, Inc. [source] Efficacy and safety of DALI LDL-apheresis at high blood flow rates: A prospective multicenter studyJOURNAL OF CLINICAL APHERESIS, Issue 4 2003T. Wendler Abstract Direct adsorption of lipids (DALI) is the first LDL-apheresis method compatible with whole blood. Usually, the blood flow rate is adjusted at 60,80 ml/min, which results in session times of about 2 hr. The present study was performed to test the safety and efficacy of low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] removal by DALI at high blood flow rates in order to reduce treatment time. Thirteen chronic DALI patients in seven centers suffering from hypercholesterolemia (LDL-C 162 ± 42 mg/dl at baseline) and coronary artery disease were treated on a weekly or biweekly basis by DALI apheresis. The blood flow rate QB was held constant for at least two sessions, respectively, and was increased from 60 to 80, 120, 160, 200, and 240 ml/min. All patients had pre-existing av-fistulas. The anticoagulation was performed by a heparin bolus plus ACD-A at a ratio of citrate: blood ranging from 1:20 to 1:90. Clinically, the sessions were well tolerated and only 26/201 sessions (12%) of the treatments were fraught with minor adverse events. Acute LDL-C reductions (derived from LDL-C levels determined by lipoprotein electrophoresis) averaged 72/66/60/53/50/48% for QB = 60/80/120/160/200/240 ml/min. Lp(a) reductions were 68/67/62/60/58/56%, whereas HDL-C losses were ,10%. Routine blood chemistries and blood cell counts remained in the normal range. Treatment times averaged 142/83/45 min at Qb = 60/120/240 ml/min. On average, DALI LDL-apheresis could be performed safely and effectively at high blood flow rates up to at least 120 ml/min in patients with good blood access, which significantly reduced treatment time from 142 to 83 min (,42%). J. Clin. Apheresis 18:157,166, 2003. © 2003 Wiley-Liss, Inc. [source] Comparison of ATP production in whole blood and lymphocyte proliferation in response to phytohemagglutininJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 5 2007Nancy H. Augustine Abstract Lymphocyte proliferation in response to mitogens, phytohemagglutinin (PHA), concanavalin A, pokeweed, and/or specific antigens has been the method of choice for in vitro diagnosis of cell-mediated immune dysfunction. Recently, an assay to measure intracellular adenosine triphosphate (ATP) production in response to PHA has been developed that requires a shorter, overnight incubation. We compared a standard 5- to 7-day lymphocyte mitogen stimulation assay utilizing tritiated thymidine (3H-thy) incorporation to one in which ATP production in response to PHA by CD4-positive cells is measured in a luminometer that requires only 18,24,hr. A total of 20 patient samples suspected of having decreased cell-mediated immunity submitted for mitogen induced lymphocyte proliferation and 21 normal controls were tested in both assays. A comparison of these two methods has demonstrated that the screening ATP assay has a sensitivity at 24,hr of 100% in detecting decreased PHA induced lymphocyte proliferation at 5 days and a specificity of 85% in the samples obtained from normal controls. The data indicate that the ATP assay may be a useful screening tool for more rapid detection of blood samples with decreased cell-mediated immune responses. However, a positive screen should always be confirmed by 3H-thy uptake using mitogens and recall antigens like candida and tetanus. J. Clin. Lab. Anal. 21:265,270, 2007. © 2007 Wiley-Liss, Inc. [source] Latent and lytic infection of isolated guinea pig enteric ganglia by varicella zoster virusJOURNAL OF MEDICAL VIROLOGY, Issue S1 2003Jason J. Chen Abstract Varicella zoster virus (VZV) has been demonstrated to infect guinea pig enteric neurons in vitro. Latent infection of isolated enteric neurons is established when the cultures predominantly consist of neurons and they are exposed to cell-free VZV. Neurons harboring latent infection survive for weeks in vitro and express mRNA encoding ORFs 4, 21, 29, 40, 62, and 63, but not 14(gC) or 68 (gE) (although DNA encoding the glycoproteins is present). The expressed proteins are the same as those that are also expressed in human sensory neurons harboring latent VZV. In addition to mRNA, the immunoreactivities of ORFs 4, 21, 29, 62, and 63 can be detected. ORF 62 and 29 proteins are cytoplasmic and not intranuclear. VZV does not preferentially infect and/or become latent in intrinsic enteric primary afferent neurons indicating that the virus is latent in these neurons. Lytic infection occurs when mixed cultures of neurons and non-neuronal cells of the bowel wall are exposed to cell-free VZV or when isolated enteric neurons are exposed to cell-associated VZV. When lytic infection occurs, enteric neurons die within 48 hr. Prior to their death, neurons express VZV glycoproteins, including gE and gB, and ORF 62 and 29 proteins are intranuclear. This new animal model should facilitate studies of VZV latency and the efficacy of therapies designed to prevent VZV infecion, latency, and reactivation. J. Med. Virol. 70:S71,S78, 2003. © 2003 Wiley-Liss, Inc. [source] Role of mitogen-activated protein kinases in the mechanism of oxidant-induced cell swelling in cultured astrocytesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2010M. Moriyama Abstract Cytotoxic brain edema, usually a consequence of astrocyte swelling, is an important complication of stroke, traumatic brain injury, hepatic encephalopathy, and other neurological disorders. Although mechanisms underlying astrocyte swelling are not fully understood, oxidative stress (OS) has generally been considered an important factor in its pathogenesis. To better understand the mechanism(s) by which OS causes cell swelling, we examined the potential involvement of mitogen-activated protein kinases (MAPKs) in this process. Cultures exposed to theoxidant H2O2 (10, 25, 50 ,M) for different time periods (1,24 hr) significantly increased cell swelling in a triphasic manner. Swelling was initially observed at 10 min (peaking at 30 min), which was followed by cell shrinkage at 1 hr. A subsequent increase in cell volume occurred at approximately 6 hr, and the rise lasted for at least 24 hr. Cultures exposed to H2O2 caused the activation of MAPKs (ERK1/2, JNK and p38-MAPK), whereas inhibition of MAPKs diminished cell swelling induced by 10 and 25 ,M H2O2. These findings suggest that activation of MAPKs is an important factor in the mediation of astrocyte swelling following oxidative stress. © 2010 Wiley-Liss, Inc. [source] Mitochondrial localization of DJ-1 leads to enhanced neuroprotectionJOURNAL OF NEUROSCIENCE RESEARCH, Issue 1 2009Eunsung Junn Abstract Mutations in DJ-1 (PARK7) cause recessively inherited Parkinson's disease. DJ-1 is a multifunctional protein with antioxidant and transcription modulatory activity. Its localization in cytoplasm, mitochondria, and nucleus is recognized, but the relevance of this subcellular compartmentalization to its cytoprotective activity is not fully understood. Here we report that under basal conditions DJ-1 is present mostly in the cytoplasm and to a lesser extent in mitochondria and nucleus of dopaminergic neuroblastoma SK-N-BE(2)C cells. Upon oxidant challenge, more DJ-1 translocates to mitochondria within 3 hr and subsequently to the nucleus by 12 hr. The predominant DJ-1 species in both mitochondria and nucleus is a dimer believed to be the functional form. Mutating cysteine 106, 53, or 46 had no impact on the translocation of DJ-1 to mitochondria. To study the relative neuroprotective activity of DJ-1 in mitochondria and nucleus, DJ-1 cDNA constructs fused to the appropriate localization signal were transfected into cells. Compared with 30% protection against oxidant-induced cell death in wild-type DJ-1-transfected cells, mitochondrial targeting of DJ-1 provided a significantly stronger (55%) cytoprotection based on lactate dehydrogenase release. Nuclear targeting of DJ-1 preserved cells equally as well as the wild-type protein. These observations suggest that the time frame for the translocation of DJ-1 from the cytoplasm to mitochondria and to the nucleus following oxidative stress is quite different and that dimerized DJ-1 in mitochondria is functional as an antioxidant not related to cysteine modification. These findings further highlight the multifaceted functions of DJ-1 as a cytoprotector in different cellular compartments. © 2008 Wiley-Liss, Inc. [source] Thyroid hormone stimulates ,-glutamyl transpeptidase in the developing rat cerebra and in astroglial culturesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2005Asmita Dasgupta Abstract Hypothyroidism in the developing rat brain is associated with enhanced oxidative stress, one of the earliest manifestations of which is a decline in the level of glutathione (GSH). To investigate the role of thyroid hormone (TH) on GSH homeostasis, the effect of TH on ,-glutamyl transpeptidase (,GT), the key enzyme involved in the catalysis of GSH, was studied. Hypothyroidism declined the specific activity of cerebral ,GT at all postnatal ages examined (postnatal day 1,20) with a maximum inhibition of 42% at postnatal day 10. Intraperitoneal injection of TH to 15-day-old rat pups increased the specific activity of ,GT by 25-30% within 4,6 hr. Treatment of primary cultures of astrocytes by TH also enhanced the specific activity of ,GT by 30,40% within 4,6 hr. The induction of ,GT by TH was blocked by actinomycin D or cycloheximide. ,GT is an ectoenzyme that is normally involved in the catabolism of GSH released by astrocytes. In the presence of the ,GT-inhibitor, acivicin, GSH released in the culture medium of astrocytes increased linearly for at least 6 hr and TH had no effect on this accumulation pattern. In the absence of acivicin, GSH content of the medium from TH-treated cells was significantly lower than that of untreated controls due to activation of ,GT by TH and a faster processing of GSH. Because the products of ,GT reaction are putative precursors for neuronal GSH, the activation of ,GT by TH may be conducive to GSH synthesis in neurons and their protection from oxidative stress. © 2005 Wiley-Liss, Inc. [source] Endothelin-1 modulates anterograde fast axonal transport in the central nervous systemJOURNAL OF NEUROSCIENCE RESEARCH, Issue 5 2005Martha E. Stokely Abstract Anterograde fast axonal transport (FAxT) maintains synaptic function and provides materials necessary for neuronal survival. Localized changes in FAxT are associated with a variety of central nervous system (CNS) neuropathies, where they may contribute to inappropriate remodeling, a process more appropriately involved in synaptic plasticity and development. In some cases, developmental remodeling is regulated by localized secretion of endothelins (ETs), neuroinflammatory peptides that are also pathologically elevated in cases of neurologic disease, CNS injury, or ischemia. To investigate the potential role of ETs in these processes, we decided to test whether locally elevated endothelin-1 (ET-1) modulates FAxT in adult CNS tissues. We used the established in vivo rat optic nerve model and a novel ex vivo rat hippocampal slice model to test this hypothesis. In vivo, exogenously elevated vitreal ET-1 significantly affected protein composition of FAxT-cargos as well as the abundance and peak delivery times for metabolically-labeled proteins that were transported into the optic nerve. Proteins with molecular weights of 139, 118, 89, 80, 64, 59, 51, 45, 42, 37, and 25 kDa were evaluated at injection-sacrifice intervals (ISIs) of 24, 28, 32, and 36 hr. In acute hippocampal slices maintained on nonvascular supplies of glucose and oxygen, ET-1 significantly decreased the distance traveled along the Schaffer collateral tract by nonmetabolically-labeled lipid rafts at 5 and 10 min after pulse-labeling. In both models, ET-1 significantly affected transport or targeted delivery of FaxT-cargos, suggesting that ET-1 has the potential to modulate FAxT in adult CNS tissues. © 2005 Wiley-Liss, Inc. [source] Neuroprotective effect of hypothermia at defined intraischemic time courses in cortical culturesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2001Sriranganathan Varathan Abstract Many experimental and clinical studies have shown that hypothermia confers cerebroprotective benefits against ischemic insults. Because of the many conflicting reports on hypothermic neuroprotection, we undertook this cellular study to identify the optimal temperature or a range of temperatures for maximal neuroprotection at different times (6,24 hr) during ischemic insults. Cultured Wistar rat cortical neurons were exposed to oxygen deprivation at defined times and temperatures (37°C normothermia, 32°C mild hypothermia, 27°C moderate hypothermia, 22°C deep hypothermia, and 17°C profound hypothermia). The survival rate of neurons was evaluated by assessing viable neurons on photomicrographs. The normothermic group demonstrated a significantly lower survival rate of cultured neurons (6 hr, 80.3% ± 2.7%; 12 hr, 56.1% ± 2.1%; 18 hr, 34.2% ± 1%; 24 hr, 18.1% ± 2.2%) compared to hypothermic groups (P < 0.001). The survival rate for the profound hypothermic group was significantly reduced (P < 0.01) compared to other hypothermic groups (at 17°C: 12 hr, 85.9% ± 2.5%, 18 hr, 74.7% ± 3.7%, 24 hr, 58.7% ± 2.7%). Almost equal survival rates were observed among mild, moderate, and deep hypothermic groups following <18 hr exposure to hypoxia, but the deep hypothermic group showed a significantly higher survival rate (84.1% ± 1.6%; P < 0.001) when subjected to hypoxia for 24 hr. In conclusion, hypothermia offers marked neuroprotection against hypoxia, but attenuation of neuronal cell death was less with profound hypothermia compared to mild, moderate, and deep hypothermia. Deep hypothermia affords maximal protection of neurons compared to mild and moderate hypothermia during long-lasting hypoxia (>18 hr). J. Neurosci. Res. 65:583,590, 2001. © 2001 Wiley-Liss, Inc. [source] Detection of Recent Ethanol Intake With New Markers: Comparison of Fatty Acid Ethyl Esters in Serum and of Ethyl Glucuronide and the Ratio of 5-Hydroxytryptophol to 5-Hydroxyindole Acetic Acid in UrineALCOHOLISM, Issue 5 2005K Borucki Background: At present, recent ethanol consumption can be routinely detected with certainty only by direct measurement of ethanol concentration in blood or urine. Because ethanol is rapidly eliminated from the circulation, however, the time span for this detection is in the range of hours. Several new markers have been proposed to extend the detection interval, but their characteristics have not yet justified their use in routine clinical practice. We therefore investigated three new markers and compared their kinetics and sensitivities: (1) fatty acid ethyl esters (FAEEs) in serum, (2) ethyl glucuronide (EtG) in urine, and (3) the ratio of 5-hydroxytryptophol to 5-hydroxyindole acetic acid (5-HTOL/5-HIAA) in urine. Methods: Seventeen healthy men participated in a drinking experiment. Blood and urine samples were collected twice daily on three consecutive days and once daily on days 4 and 5. Ethanol concentration was determined by gas chromatography, FAEE levels, by gas chromatography with mass spectrometry, EtG concentration, by liquid chromatography-tandem mass spectrometry, and 5-HTOL/5-HIAA ratio, by high-performance liquid chromatography. Results: The peak serum ethanol concentrations of the subjects ranged from 5.4 to 44.7 mmol/liter (mean ± SD, 30.1 ± 9.1 mmol/liter). In the case of the serum ethanol determination, 100% sensitivity was reached only immediately after the end of the drinking experiment, and in the case of FAEE levels and 5-HTOL/5-HIAA ratio, it tested for 6.7 hr after the end of the ethanol intake. Thereafter, these latter parameters declined until 15.3 hr (FAEEs) and 29.4 hr (5-HTOL/5-HIAA), subsequently remaining in a stable range until 78.5 hr without further decrease. In contrast, EtG concentration showed 100% sensitivity until 39.3 hr and thereafter decreased, falling to below the limit of quantification of 0.1 mg/liter at 102.5 hr. Conclusion: After moderate drinking, EtG in the urine proved to be a superior marker of recent ethanol consumption in healthy subjects. This is because EtG is a direct ethanol metabolite, it occurs in the urine only when ethanol has been consumed, and its sensitivity remains at the level of 100% for 39.3 hr. [source] Effects of Ethanol and Transforming Growth Factor , (TGF,) on Neuronal Proliferation and nCAM ExpressionALCOHOLISM, Issue 8 2002Michael W. Miller Background Developmental events targeted by ethanol are cell proliferation, neuronal migration, and neurite outgrowth; the latter processes being mediated by neural cell adhesion molecule (nCAM). TGF,1 affects all three of these events. Therefore, the effects of ethanol on transforming growth factor (TGF) ,1 mediated activities in neocortical neurons in vitro were examined. Methods Primary cultures of cortical neurons were obtained from 16-day-old fetuses and were treated with TGF,1 (0 or 10 ng/ml) and ethanol (0 or 400 mg/dl) for 48 hr. The effects of these substances on cell numbers, [3H]thymidine incorporation, and the expression of nCAM were determined. Results Both cell growth (the change in cell numbers over time) and cell proliferation were inhibited by TGF,1 and ethanol. The action of these two anti-mitogenic factors was additive. In contrast, TGF,1 also promoted the expression of three isoforms of nCAM. Likewise, ethanol also up-regulated nCAM expression. On the other hand, ethanol blocked TGF,1-mediated nCAM expression, particularly of the 120 and 180 kDa isoforms. Conclusions TGF, ligands inhibit neuronal proliferation and stimulate the expression of cell adhesion proteins that promote the movement of postmitotic neurons and process outgrowth. Ethanol alters these phenomena as well. Thus, in neurons, as in astrocytes, TGF,1 and ethanol may interact. [source] Ethanol Effects on Nitric Oxide Production in Cerebral Pial CulturesALCOHOLISM, Issue 4 2001Chin-Lung Shih Background: Although alcohol abusers are known to have higher incidences of hemorrhagic cerebrovascular diseases, it is not known whether these changes are associated with ethanol (EtOH) action on nitric oxide (NO) production in the cerebrovascular cells. The purpose of this study was to examine the effects of EtOH treatment on basal and cytokine-induced NO production in cortical pial cultures. Methods: Cell cultures for this study included murine primary pial vascular cells, primary glial cells and cortical neurons. These cells were exposed to cytokines or EtOH for 24 to 48 hr. The culture media were used for measurement of nitrite, as an indication for NO release, and lactate dehydrogenase (LDH), as an index of cell membrane integrity. In addition, immunocytochemical determinations were carried out to identify cell types and to assess inducible nitric oxide synthase (iNOS). Results: Exposure of primary pial vascular cultures to cytokines that consisted of interleukin-1, (IL-1,; 250 pg/mL) and interferon-, (IFN,; 2 ng/mL) or to EtOH (50 to 100 mM) for 24 to 48 hr significantly elevated NO production. NO production could be attenuated by N -nitro-L-arginine (N-arg), a nonspecific NOS inhibitor, or aminoguanidine (AG), an iNOS inhibitor. Increased iNOS immunoreactivity was observed in cytokines- or EtOH-treated pial cells. When pial cells were cocultured with cortical neurons, prolonged EtOH exposure led to a large increase in NO production as well as LDH release. However, this increase was not observed in pial culture alone or in mixed cortical culture. Nevertheless, inhibition of NO production with N-arg or AG did not alter the EtOH-induced LDH release in the pial cells cocultured with cortical neurons. Conclusion: These results show that EtOH exposure led to increased production of NO in primary pial cell culture. In mixed culture that contained cortical neurons and pial cells, EtOH induced increase in NO as well as LDH release, which is an indication of loss of cell membrane integrity. However, EtOH-mediated LDH release in mixed cortical pial cultures was not a consequence of the increase in NO production by these cells. Studies that use mixed cortical-pial cultures may provide a unique in vitro system for examining the interactions among glial cells, neurons, and cerebrovascular cells. [source] Orbofiban: An orally active GPIIb/IIIa platelet receptor antagonistMEDICINAL RESEARCH REVIEWS, Issue 3 2001Nancy S. Nicholson Abstract A key role has been established for platelet activation and thrombus formation in the pathogenesis of acute coronary syndromes, and restenosis after percutaneous interventions. Antiplatelet agents that have a wider spectrum of activity than aspirin, and clopidogrel would be expected to provide improved antithrombotic protection. Preclinical studies were used to predict clinical efficacy of orally active GPIIb/IIIa antagonists such as xemilofiban, sibrafiban, lefradafiban, and orbofiban. While clinical trials have shown potent and sustained platelet inhibition, outcomes of trials with these first generation GPIIb/IIIa compounds have been disappointing. The active moiety of orbofiban is a potent and specific inhibitor of fibrinogen binding to GPIIb/IIIa, leading to inhibition of platelet aggregation to a wide variety of agonists. Studies comparing inhibition of aggregation and bleeding suggest that chronic inhibition of platelet aggregation can be achieved without major bleeding side effects. Thrombus formation is prevented in canine models of thrombosis. Orbofiban is approximately 28% bioavailable with a t1/2 of 18,hr. The high bioavailability, long half-life, and potential safety suggest orbofiban would be suitable for chronic oral administration. Clinical data demonstrate that orally administered orbofiban has the desired pharmacodynamic effect of inhibiting platelet aggregation but does not demonstrate clinical benefit when examined in large-scale trials. © 2001 John Wiley & Sons, Inc. Med Res Rev, 21, No. 3, 211,226, 2001 [source] Sialidase of Streptococcus intermedius: a putative virulence factor modifying sugar chainsMICROBIOLOGY AND IMMUNOLOGY, Issue 10 2010Ayuko Takao ABSTRACT A sialidase gene of Streptococcus intermedius was cloned. It was most similar to nanA, a major sialidase gene in Streptococcus pneumoniae, and was expressed in Escherichia coli. Since the gene-knockout S. intermedius strain lost detectable sialidase activity, the gene might code, either solely or mainly, the glycosidase in the bacterial genome. Polymerase chain reaction using the primers for the nanA homologue in S. intermedius (described as nanA below) showed that this sialidase gene was commonly distributed within the isolates of S. intermedius, but not found in the strains of other species among the anginosus group. In biofilm formation assay under cultivation with mucin, the nanA -deleted S. intermedius maintained the amount of biofilm for 72 hr, while that of the parent strain decreased during incubation from 24 to 72 hr. Since sialidase activity in the parent strain increased during that time period, sialidase might contribute to the degradation of biofilm under sialic acid-rich conditions. When S. intermedius was added into the HepG2 hepatoma culture, the calculated disassociation constant (Kd) of EDTA-releasable bacterial adhesion to the cells was higher in the nanA -deleted strain than in the parent. Furthermore, the rate constant, assuming endocytosis of the bacterium mediated by ASGP-R in HepG2 cells, seemed to be increased by sialidase pretreatment of the bacterial cells before addition to the cell culture. According to the results, modification of sugar chains by sialidase on the bacterial surface and in the surrounding environment might influence both bacterial interaction and host,bacterial interaction in S. intermedius. [source] | |||||||||||||||||||||||||||||||