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Mechanisms Other (mechanism + other)
Selected AbstractsReview article: acidity and volume of the refluxate in the genesis of gastro-oesophageal reflux disease symptomsALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2007D. SIFRIM Summary Background A number of mechanisms, other than acid reflux, may be responsible for the symptoms of gastro-oesophageal reflux disease. Aim To assess the importance of non-acid reflux mechanisms. Methods This review is based on presentations and discussion at a workshop, where specialists in the field analysed data relating to these mechanisms. Results Weakly acidic reflux, pH (4,7), detected with impedance,pHmetry is associated with regurgitation and atypical gastro-oesophageal reflux disease symptoms. It is not clear whether pepsin and trypsin can elicit symptoms, but bile can elicit heartburn. The magnitude of reflux-induced oesophageal distension can be determined by high frequency ultrasonography and is not reduced by proton pump inhibition, suggesting that persisting symptoms ,on' a proton pump inhibitor may still be due to oesophageal distension by non-acidic reflux. Exaggerated longitudinal muscle contraction can induce non-acid-related heartburn. Preliminary studies showed a positive effect of baclofen, surgery or endoscopic procedures to reduce weakly acidic reflux. Conclusion Mechanisms other than acid reflux are involved in some of the symptoms of gastro-oesophageal reflux disease. Controlled outcome studies are needed to clarify their roles and the indications for antireflux procedures in patients with persistent symptoms whilst ,on' a proton pump inhibitor. [source] The effects of thermal conduction on the intracluster medium of the Virgo clusterMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2005Edward C. D. Pope ABSTRACT Thermal conduction has been suggested as a possible mechanism by which sufficient energy is supplied to the central regions of galaxy clusters to balance the effect of radiative cooling. Recent high-resolution observations of the nearby Virgo cluster make it an ideal subject for an attempt to reproduce the properties of the cluster by numerical simulations, because most of the defining parameters are comparatively well known. Here, we present the results of a simulated high-resolution, 3D Virgo cluster for different values of thermal conductivity ( times the full Spitzer value). Starting from an initially isothermal cluster atmosphere, we allow the cluster to evolve freely over time-scales of roughly 1.3,4.7 × 109 yr. Our results show that thermal conductivity at the Spitzer value can increase the central intracluster medium (ICM) radiative cooling time by a factor of roughly 3.6. In addition, for larger values of thermal conductivity, the simulated temperature and density profiles match the observations significantly better than for the lower values. However, no physically meaningful value of thermal conductivity was able to postpone the cooling catastrophe (characterized by a rapid increase in the central density) for longer than a fraction of the Hubble time nor explain the absence of a strong cooling flow in the Virgo cluster today. We also calculate the effective adiabatic index of the cluster gas for both simulation and observational data and compare the values with theoretical expectations. Using this method, it appears that the Virgo cluster is being heated in the cluster centre by a mechanism other than thermal conductivity. Based on this and our simulations, it is also likely that the thermal conductivity is suppressed by a factor of at least 10 and probably more. Thus, we suggest that thermal conductivity, if present at all, has the effect of slowing down the evolution of the ICM, by radiative cooling, but only by a factor of a few. [source] Propagating contractions of the circular muscle evoked by slow stretch in flat sheets of guinea-pig ileumNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2001S. J. H. Brookes Flat sheet preparations of guinea-pig ileum were stretched circumferentially and the propagation of circular muscle contractions along the preparation was investigated. Slow stretch, at 100 ,m s,1, of a 50-mm long flat sheet of intestine, evoked circular muscle contraction orally, which propagated, without decrement, for up to 30 mm. This occurred despite circular muscle shortening being prevented, and in the absence of propulsion of contents. Thus, propagation in this flat sheet preparation could not explained on the basis of neuro-mechanical interactions, as previously proposed. Irrespective of the length of preparations, contraction amplitude decreased significantly in the most aboral 10,15 mm of intestine. This was not due to descending inhibitory pathways, but was associated with interruption of ascending excitatory pathways near the aboral end. Slow waves were not detected in circular muscle cells in any preparation (n=8). Smooth muscle action potentials evoked in circular muscle cells, in the presence of tetrodotoxin (TTX, 0.6 ,mol L,1), did not propagate for more than 1 mm in the longitudinal axis. Propagation of circular muscle activity, evoked by slow stretch of flat sheet preparations, reveals the presence of a mechanism other than myogenic spread or the neuro-mechanical interactions previously proposed to account for propagation; the nature of this mechanism remains to be determined. [source] Telomerase: not just for the elongation of telomeres,BIOESSAYS, Issue 2 2006Rodrigo T. Calado Telomerase RNA component (TERC) and telomerase reverse transcriptase (TERT) function together to elongate telomeres and to protect chromosomal ends. Recent studies have discovered that overexpression of telomerase's TERT subunit promoted epidermal stem-cell mobilization, hair growth and stem-cell proliferation without changes in length of telomeres.1,2 This telomerase functional characteristic is TERC independent and is operated through a mechanism other than telomere elongation. These findings open new doors for future explorations to understand telomerase function and its interaction with other cell components in the regulation of cell senescence and tumorigenesis. BioEssays 28: 109,112, 2006. © 2006 Wiley periodicals, Inc. [source] STIMULATION OF OESTROGEN RECEPTOR-EXPRESSING ENDOTHELIAL CELLS WITH OESTROGEN REDUCES PROLIFERATION OF COCULTURED VASCULAR SMOOTH MUSCLE CELLSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 3 2008Malin Odenlund SUMMARY 1Oestrogen reduces vascular smooth muscle cell proliferation in mouse vascular injury models. Data on the antiproliferative effect of oestrogen in cultured vascular smooth muscle cells (VSMC) are less conclusive than those obtained in whole animal studies. 2In the present study, we investigated the hypothesis that oestrogen-induced attenuation of VSMC proliferation is facilitated by the presence of endothelial cells (EC) using a coculture system of EC and VSMC. 3Treatment with a physiological concentration of oestrogen (17,-estradiol (E2); 100 nmol/L) had no effect on fetal calf serum (FCS)-stimulated DNA synthesis in either A7r5 VSMC or bEnd.3 EC. However, stimulation of bEnd. 3 cells with E2 in a coculture system of bEnd.3 and A7r5 cells reduced FCS-induced DNA synthesis in A7r5 cells by approximately 45%. The nitric oxide synthase inhibitor NG -nitro- l- arginine methyl ester (l -NAME; 100 µmol/L) did not reverse the oestrogen-induced attenuation of DNA synthesis. The antiproliferative effect of E2 may be mediated via either oestrogen receptor (ER) ,, ER, or both because the bEnd.3 cells expressed immunoreactivity for both ER subtypes. 4These data show that ER,- and ER,-expressing endothelial cells, which are stimulated with a physiological concentration of oestrogen, release a factor(s) that arrests the proliferation of cocultured VSMC. Oestrogen-induced attenuation of vascular smooth muscle cell proliferation is not prevented by l -NAME, suggesting that a mechanism other than endothelial NO is involved. [source] Curcumin downregulates H19 gene transcription in tumor cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 5 2008Renata Novak Kujund Abstract Curcumin (diferuloymethane), a natural compound used in traditional medicine, exerts an antiproliferative effect on various tumor cell lines by an incompletely understood mechanism. It has been shown that low doses of curcumin downregulate DNA topoisomerase II alpha (TOP2A) which is upregulated in many malignances. The activity of TOP2A is required for RNA polymerase II transcription on chromatin templates. Recently, it has been reported that CTCF, a multifunctional transcription factor, recruits the largest subunit of RNA polymerase II (LS Pol II) to its target sites genome-wide. This recruitment of LS Pol II is more pronounced in proliferating cells than in fully differentiated cells. As expression of imprinted genes is often altered in tumors, we investigated the potential effect of curcumin treatment on transcription of the imprinted H19 gene, located distally from the CTCF binding site, in human tumor cell lines HCT 116, SW 620, HeLa, Cal 27, Hep-2 and Detroit 562. Transcription of TOP2A and concomitantly H19 was supressed in all tumor cell lines tested. Monoallelic IGF2 expression was maintained in curcumin-treated cancer cells, indicating the involvement of mechanism/s other than disturbance of CTCF insulator function at the IGF2/H19 locus. Curcumin did not alter H19 gene transcription in primary cell cultures derived from normal human tissues. J. Cell. Biochem. 104: 1781,1792, 2008. © 2008 Wiley-Liss, Inc. [source] The alpha-amino group of l -arginine mediates its antioxidant effectEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2001S. Wallner Antioxidant effects may constitute part of the possible antiatherogenic effects of the amino acid l -arginine. These antioxidant properties were further characterized in a model of lipoprotein oxidation. Oxidation of lipoproteins in unfractionated human serum was continuously monitored by a fluorescent probe. The antioxidant effects of l -arginine, N -,-acetyl-arginine and vitamin E in combination with l -arginine were measured after initiation of free radical generation with either copper or 2,2,-azobis(2-amidinopropane) hydrochloride (AAPH). The half-time of the fast propagation rate for copper-induced lipoprotein oxidation increased after incubation with l -arginine in a dose-dependent manner (P < 0·01). N -,-acetyl-arginine did not show such effects. Vitamin E and l -arginine show different effects on copper-induced oxidation, the former increasing only lag-time, the latter increasing only propagation rate, and do not have reciprocal effects. In contrast to copper-induced oxidation, l -arginine increased the lag-time of AAPH-induced lipoprotein oxidation (P < 0·01), with no effect on the propagation rate at physiological concentrations. Again, N -,-acetyl-arginine did not show any antioxidant effects. Our experiments provide further evidence that mechanisms other than serving as a substrate for the NO-synthase could be involved in the antiatherosclerotic effect of l -arginine. In addition, our experiments clearly show, that the antioxidant effect of l -arginine is due to a chemical moiety different from that serving as the substrate for NO biosynthesis. [source] Lesson from performing SCORADs in children with atopic dermatitis: Subjective symptoms do not correlate well with disease extent or intensityINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 6 2006K. L. E. Hon MBBS Background, Atopic dermatitis (AD) is a distressing disease associated with pruritus and sleep disturbance. It is not known how well these symptoms correlate with the extent and intensity of eczematous involvement. We evaluated whether: (i) the level of sleep loss correlates with pruritus and (ii) the level of pruritus correlates with the extent or severity of AD in children according to the SCORing Atopic Dermatitis (SCORAD) index. Method, Patients with AD younger than 18 years old were recruited from the pediatric dermatology clinic of a university teaching hospital, and AD severity was evaluated by the SCORAD index. Results, One hundred and eighty-two Chinese children with AD (107 boys and 75 girls) [mean (SD) age of 9.6 (4.2) years] were recruited. Their mean (SD) overall SCORAD was 30.1 (19.2). Sleep loss was strongly correlated with pruritus (r = 0.57, P < 0.001). However, the two subjective symptoms were only weakly correlated with the objective signs (extent and intensity) of AD. The correlations between pruritus and extent and intensity were 0.42 (P < 0.001) and 0.38 (P < 0.001), respectively, and the correlations between sleep loss and extent and intensity were 0.38 (P < 0.001) and 0.34 (P < 0.001), respectively. Conclusion, We speculate that the lack of a better correlation was either because pruritus and sleep loss as reported by parents were imprecise, or that mechanisms other than disease extent or severity are responsible for the pathogenesis of these subjective symptoms. [source] Excess silica in omphacite and the formation of free silica in eclogiteJOURNAL OF METAMORPHIC GEOLOGY, Issue 1 2007H. W. DAY Abstract Silica lamellae in eclogitic clinopyroxene are widely interpreted as evidence of exsolution during decompression of eclogite. However, mechanisms other than exsolution might produce free silica, and the possible mechanisms depend in part on the nature and definition of excess silica. ,Excess' silica may occur in both stoichiometric and non-stoichiometric pyroxene. Although the issue has been debated, we show that all common definitions of excess silica in non-stoichiometric clinopyroxene are internally consistent, interchangeable, and therefore equivalent. The excess silica content of pyroxene is easily illustrated in a three-component, condensed composition space and may be plotted directly from a structural formula unit or recalculated end-members. In order to evaluate possible mechanisms for the formation of free silica in eclogite, we examined the net-transfer reactions in model eclogites using a Thompson reaction space. We show that there are at least three broad classes of reactions that release free silica in eclogite: (i) vacancy consumption in non-stoichiometric pyroxene; (ii) dissolution of Ti-phases in pyroxene or garnet; (iii) reactions between accessory phases and either pyroxene or garnet. We suggest that reliable interpretation of the significance of silica lamellae in natural clinopyroxene will require the evaluation not only of silica solubility, but also of titanium solubility, and the possible roles of accessory phases and inclusions on the balance of free silica. [source] Glial,Neuronal,Endothelial Interactions are Involved in the Control of GnRH SecretionJOURNAL OF NEUROENDOCRINOLOGY, Issue 3 2002Vincent PrevotArticle first published online: 8 APR 200 Abstract In recent years compelling evidence has been provided that cell,cell interactions involving non-neuronal cells, such as glial and endothelial cells, are important in regulating the secretion of GnRH, the neuropeptide that controls both sexual development and adult reproductive function. Modification of the anatomical relationship that exist between GnRH nerve endings and glial cell processes in the external zone of the median eminence modulates the access of GnRH nerve terminals to the portal vasculature during the oestrous cycle. The establishment of direct neuro-haemal junctions between GnRH neuroendocrine terminals and the portal vasculature on the day of pro-oestrus may be critical for the transfer of GnRH upon its release into the fenestrated capillaries of the median eminence. Notwithstanding the importance of these plastic rearrangements, glial and endothelial cells also regulate GnRH neuronal function via specific cell,cell signalling molecules. While endothelial cells of the median eminence use nitric oxide to effect this regulatory control, astrocytes employ several growth factors, and in particular those of the EGF family and their erbB receptors to facilitate GnRH release during sexual development. Loss of function of each of these erbB receptors involved in the astroglial control of GnRH secretion leads to delayed sexual development. It is clear that regulation of GnRH secretion by cell,cell communication mechanisms other than transsynaptic inputs is an important component of the central neuroendocrine process controlling mammalian reproduction. [source] Effects of interocclusal appliances on EMG activity during parafunctional tooth contactJOURNAL OF ORAL REHABILITATION, Issue 6 2003A. L. Roark summary, To test the hypothesis that a flat plane interocclusal appliance affects the electromyographic (EMG) activity of the temporalis and masseter muscles in pain-free individuals, maxillary splints were fabricated for 20 individuals who reported no history, signs or symptoms of myofascial pain or arthralgia as determined by two trained, independent examiners. Subjects were instructed to establish light tooth contact, maximum clenching, and moderate clenching with/without the splint in place (as determined by random assignment) while EMG data from the left and right temporalis and masseter muscles were recorded. A 5-min biofeedback training session to relax the masticatory muscles was followed by a repetition of the tooth contact/clenching tasks with/without the splint in place. With the splint in place, the activity of the temporalis muscles decreased for all tasks, significantly for the left and right temporalis under maximal clenching and for the right temporalis under moderate clenching. In contrast, the activity of the masseter muscles increased under light and moderate clenching (significantly for the left masseter under moderate clenching) and decreased slightly under maximal clenching. The effectiveness of interocclusal appliances may be due to mechanisms other than redistribution of adverse loading. [source] Cellular and molecular characterization of a murine non-union modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2004P. Choi Abstract Purpose. We have developed a method to study the molecular and cellular events underlying delayed skeletal repair in a model that utilizes distraction osteogenesis. Methods. The clinical states of delayed union and non-union were reproduced in this murine model by altering distraction parameters such as the inclusion and exclusion of a latency phase and variations in the rate and rhythm of distraction. Radiographic, cellular, and molecular analyses were performed on the distraction tissues. Results. Eliminating the latency period delayed bony union, but did not appreciably alter the extent of platelet endothelial cell adhesion marker (PECAM) immunostaining. Following elimination of a latency phase and a threefold increase in the rate of distraction, there was a further delay in bone regeneration and a higher rate of non-union (60%). Instead of bone, the distraction gap was comprised of adipose or fibrous tissue. Once again, despite the rigorous distraction protocol, we detected equivalent PECAM staining within the distraction gap. In a minority of cases, cartilage and osseous tissues occupied the distraction gap likely by a prolonged process of endochondral ossification. Conclusions. Here, we have altered the mechanical environment in such a way to reproducibly create delays in skeletal regeneration. These delays in skeletal tissue regeneration appear to develop even in the presence of endothelial cells, which suggests that mechanisms other than a disruption to the vascular network can account for some cases of non-union. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Pharmacologic Dissociation Between Impulsivity and Alcohol Drinking in High Alcohol Preferring MiceALCOHOLISM, Issue 8 2010Brandon G. Oberlin Background:, Impulsivity is genetically correlated with, and precedes, addictive behaviors and alcoholism. If impulsivity or attention is causally related to addiction, certain pharmacological manipulations of impulsivity and/or attention may affect alcohol drinking, and vice versa. The current studies were designed to explore the relationship among impulsivity, drinking, and vigilance in selectively bred High Alcohol Preferring (HAP) mice, a line that has previously demonstrated both high impulsivity and high alcohol consumption. Amphetamine, naltrexone, and memantine were tested in a delay discounting (DD) task for their effects on impulsivity and vigilance. The same drugs and doses were also assessed for effects on alcohol drinking in a 2-bottle choice test. Methods:, HAP mice were subjected to a modified version of adjusting amount DD using 0.5-second and 10-second delays to detect decreases and increases, respectively, in impulsive responding. In 2 experiments, mice were given amphetamine (0.4, 0.8, or 1.2 mg/kg), naltrexone (3 and 10 mg/kg), and memantine (1 and 5 mg/kg) before DD testing. Another pair of studies used scheduled access, 2-bottle choice drinking to assess effects of amphetamine (0.4, 1.2, or 3.0 mg/kg), naltrexone (3 and 10 mg/kg), and memantine (1 and 5 mg/kg) on alcohol consumption. Results:, Amphetamine dose-dependently reduced impulsivity and vigilance decrement in DD, but similar doses left alcohol drinking unaffected. Naltrexone and memantine decreased alcohol intake at doses that did not affect water drinking but had no effects on impulsivity or vigilance decrement in the DD task. Conclusions:, Contrary to our hypothesis, none of the drugs tested here, while effective on either alcohol drinking or impulsivity, decreased both behaviors. These findings suggest that the genetic association between drinking and impulsivity observed in this population is mediated by mechanisms other than those targeted by the drugs tested in these studies. [source] Role of the MexXY multidrug efflux pump in moderate aminoglycoside resistance in Pseudomonas aeruginosa isolates from Pseudomonas mastitisMICROBIOLOGY AND IMMUNOLOGY, Issue 8 2008Rungtip Chuanchuen ABSTRACT The contribution of the MexXY multidrug efflux system to aminoglycoside resistance was investigated in 18 clinical isolates of Pseudomonas aeruginosa obtained from dairy cows with Pseudomonas mastitis. All of the isolates expressed MexXY as determined by reverse transcription-PCR. The loss of mexXY resulted in increased susceptibility (two- to 16-fold decline in MIC) to aminoglycosides, confirming the contribution of this system in aminoglycoside resistance in these strains. As the impact of ,mexXY varied, overexpression of MexXY alone is not sufficient for aminoglycoside resistance. Expression of mexXY also varied and did not strictly correlate with aminoglycoside insusceptibility. Transcription levels of mexY were independent on mutations in mexZ, suggesting the existence of additional regulatory mechanisms other than mexZ. [source] Population genetic signatures of diffuse co-evolution between leaf-cutting ants and their cultivar fungiMOLECULAR ECOLOGY, Issue 1 2007A. S. MIKHEYEV Abstract Switching of symbiotic partners pervades most mutualisms, despite mechanisms that appear to enforce partner fidelity. To investigate the interplay of forces binding and dissolving mutualistic pairings, we investigated partner fidelity at the population level in the attine ant,fungal cultivar mutualism. The ants and their cultivars exhibit both broad-scale co-evolution, as well as cultivar switching, with short-term symbiont fidelity maintained by vertical transmission of maternal garden inoculates via dispersing queens and by the elimination of alien cultivar strains. Using microsatellite markers, we genotyped cultivar fungi associated with five co-occurring Panamanian attine ant species, representing the two most derived genera, leaf-cutters Atta and Acromyrmex. Despite the presence of mechanisms apparently ensuring the cotransmission of symbiont genotypes, different species and genera of ants sometimes shared identical fungus garden genotypes, indicating widespread cultivar exchange. The cultivar population was largely unstructured with respect to host ant species, with only 10% of the structure in genetic variance being attributable to partitioning among ant species and genera. Furthermore, despite significant genetic and ecological dissimilarity between Atta and Acromyrmex, generic difference accounted for little, if any, variance in cultivar population structure, suggesting that cultivar exchange dwarfs selective forces that may act to create co-adaptive ant,cultivar combinations. Thus, binding forces that appear to enforce host fidelity are relatively weak and pairwise associations between cultivar lineages and ant species have little opportunity for evolutionary persistence. This implicates that mechanisms other than partner fidelity feedback play important roles in stabilizing the leafcutter ant,fungus mutualism over evolutionary time. [source] Modulation of the inflammatory response to cardiopulmonary bypass by dopexamine and epidural anesthesiaACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 10 2002F. Bach Background: Cardiopulmonary bypass (CPB) induces a systemic inflammatory reaction. Microcirculation-dependent alteration of the gut mucosal barrier with subsequent translocation of endotoxins is a postulated mechanism for this inflammatory response. This study was designed to elucidate whether two different approaches to modulate splanchnic perfusion may influence systemic inflammation to CPB. Methods: We examined 40 patients scheduled for elective coronary bypass surgery in a prospective, randomized study. One group (DPX) received dopexamine (1 µg · kg,1 · min,1) continuously after induction of anesthesia until 18 h after CPB. The control group (CON) received equal volumes of NaCl 0.9% in a time-matched fashion. In a third group (EPI) a continuous epidural infusion of bupivacaine 0.25% [(body height (cm) , 100) · 10,1=ml·h,1] was administered for the whole study period. Procalcitonin (PCT), tumor necrosis factor (TNF-,), soluble TNF receptor, human soluble intercellular adhesion molecule-1, C-reactive protein (CRP) and leukocyte count were measured as parameters of inflammation. Results: All parameters significantly increased following CPB. Increases of PCT, TNF-, and leukocyte count were significantly attenuated in the DPX and EPI groups at different time points. However, neither splanchnic blood flow nor oxygen delivery and consumption were different when compared with the CON-group. Conclusion: These results do suggest that mechanisms other than an improved splanchnic blood flow by DPX and EPI treatment have to be considered for the anti-inflammatory effects. [source] Ganglioside mimicry and peripheral nerve diseaseMUSCLE AND NERVE, Issue 6 2007Nobuhiro Yuki MD Abstract Four criteria must be satisfied to conclude that a given microorganism causes Guillain,Barré (GBS) or Fisher (FS) syndrome associated with anti-ganglioside antibodies: (1) an epidemiological association between the infecting microbe and GBS or FS; (2) isolation in the acute progressive phase of illness of that microorganism from GBS or FS patients with associated anti-ganglioside IgG antibodies; (3) identification of a microbial ganglioside mimic; and (4) a GBS or FS with associated anti-ganglioside antibodies model produced by sensitization with the microbe itself or its component, as well as with ganglioside. Campylobacter jejuni is a definitive causative microorganism of acute motor axonal neuropathy and may cause FS and related conditions. Haemophilus influenzae and Mycoplasma pneumoniae are possible causative microorganisms of acute motor axonal neuropathy or FS. Acute and chronic inflammatory demyelinating polyneuropathies may be produced by mechanisms other than ganglioside mimicry. Muscle Nerve, 2007 [source] The True and the False: Pixel-Byte SyndromePEDIATRIC DERMATOLOGY, Issue 6 2001Mario Cutrone MD The possible use of retouched images for fraudulent purposes in scientific articles, posters, and conferences is not a future but a present possibility (probably already used) that poses serious questions as to the need for additional control mechanisms other than scientific peer quality review in evaluating and accepting articles. We propose the term "pixel-byte syndrome" to illustrate how easy it might be to electronically create a new syndrome for fraudulent purposes. The aim of this article is to stimulate discussion among professionals, add some examples of easy-to-realize frauds and sow the seeds of doubt in the minds of some of the referees of journal articles and the scientific secretariat of congresses in reviewing digitally retouched images. [source] Hesperidin suppressed proliferations of both Human breast cancer and androgen-dependent prostate cancer cellsPHYTOTHERAPY RESEARCH, Issue S1 2010Choong Jae Lee Abstract Hesperidin, a flavonoid derived from citrus fruits, has been reported to show various biological effects including anticancer activity. This study investigated whether hesperidin affected the proliferation of MCF-7 human breast cancer cells transfected with green fluorescent protein (GFP)/, -tubulin (MCF-7-GFP-Tubulin cells), androgen-independent PC-3 and DU-145 prostate cancer cells, and androgen-dependent LNCaP prostate cancer cells. The results were as follows. (1) Hesperidin inhibited the proliferation of MCF-7-GFP-Tubulin cells, probably not through an antimitotic mechanism. (2) Hesperidin also inhibited both basal and testosterone-induced proliferation of LNCaP cells. (3) However, hesperidin did not significantly affect the cell proliferation of two hormone-independent prostate cancer cells, PC-3 and DU-145. It is concluded that hesperidin can inhibit the proliferation of breast cancer cells through mechanisms other than antimitosis and it is suggested that hesperidin be further investigated for the possible interaction with androgenic receptors and involvement in signaling pathway after receptor binding in prostate cancer cells through future research. Copyright © 2009 John Wiley & Sons, Ltd. [source] Cytosolic Ca2+ concentration and rate of increase of the cytosolic Ca2+ concentration in the regulation of vascular permeability in Rana in vivoTHE JOURNAL OF PHYSIOLOGY, Issue 3 2005C. A. Glass Vascular permeability is assumed to be regulated by the cytosolic Ca2+ concentration ([Ca2+]c) of the endothelial cells. When permeability is increased, however, the maximum [Ca2+]c appears to occur after the maximum permeability increase, suggesting that Ca2+ -dependent mechanisms other than the absolute Ca2+ concentration may regulate permeability. Here we investigate whether the rate of increase of the [Ca2+]c (d[Ca2+]c/dt) may more closely approximate the time course of the permeability increase. Hydraulic conductivity (Lp) and endothelial [Ca2+]c were measured in single perfused frog mesenteric microvessels in vivo. The relationships between the time courses of the increased Lp, [Ca2+]c and d[Ca2+]c/dt were examined. Lp peaked significantly earlier than [Ca2+]c in all drug treatments examined (Ca2+ store release, store-mediated Ca2+ influx, and store-independent Ca2+ influx). When Lp was increased in a store-dependent manner the time taken for Lp to peak (3.6 ± 0.9 min during store release, 1.2 ± 0.3 min during store-mediated Ca2+ influx) was significantly less than the time taken for [Ca2+]c to peak (9.2 ± 2.8 min during store release, 2.1 ± 0.7 min during store-mediated influx), but very similar to that for the peak d[Ca2+]c/dt to occur (4.3 ± 2.0 min during store release, 1.1 ± 0.5 min during Ca2+ influx). Additionally, when the increase was independent of intracellular Ca2+ stores, Lp (0.38 ± 0.03 min) and d[Ca2+]c/dt (0.30 ± 0.1 min) both peaked significantly before the [Ca2+]c (1.05 ± 0.31 min). These data suggest that the regulation of vascular permeability by endothelial cell Ca2+ may be regulated by the rate of change of the [Ca2+]c rather than the global [Ca2+]. [source] Familial transient erythroblastopenia of childhood is associated with the chromosome 19q13.2 region but not caused by mutations in coding sequences of the ribosomal protein S19 (RPS19) geneBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2002Peter Gustavsson Summary., Transient erythroblastopenia of childhood (TEC) is a rare condition, which at onset may be difficult to distinguish from Diamond,Blackfan anaemia (DBA). We have previously shown that mutations in the ribosomal protein S19 gene (RPS19) cause DBA. In order to clarify whether TEC and DBA are allelic, we investigated the segregation of markers spanning the RPS19 gene region on chromosome 19q13.2 and performed sequence analysis of all exons in the RPS19 gene in seven TEC sibling pairs. Linkage analysis supported allelism for TEC and DBA at the RPS19 gene locus and implies molecular mechanisms other than structural mutations in the RPS19 gene. [source] INTRAPERITONEAL GLYCEROL INDUCES OXIDATIVE STRESS IN RAT KIDNEYCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 8 2008Elenara Rieger SUMMARY 1Glycerol has been used for the treatment of intracranial hypertension, cerebral oedema and glaucoma. Experimentally, intramuscular administration of hypertonic glycerol solution is used to produce acute renal failure. In this model, glycerol causes rhabdomyolysis and myoglobinuria, resulting in the development of renal injury. The pathogenesis is thought to involve vascular congestion, the formation of casts and oxidative stress. However, the effect of glycerol itself independent of rhabdomyolysis has not been investigated. Therefore, the aim of the present study was to investigate the effects of i.p. glycerol on some biochemical and oxidative stress parameters in the kidney of young rats. 2Rats received 10 mL/kg, i.p., hypertonic glycerol solution (50% v/v) or saline (NaCl 0.85 g%) followed by 24 h water deprivation. Twenty-four hours after the administration of glycerol, rats were killed. Creatinine levels and the activity of creatine kinase (CK) and lactate dehydrogenase (LDH) were determined in the plasma. In addition, CK, pyruvate kinase and LDH activity and oxidative stress parameters (free radical formation, lipid peroxidation and protein carbonylation) were measured in renal tissue. 3Glycerol did not alter plasma CK activity and increased plasma creatinine levels, suggesting renal insufficiency and the absence of rhabdomyolysis. Renal CK and pyruvate kinase activity was decreased, suggesting diminution of energy homeostasis in the kidney. Plasma and renal LDH activity was decreased, whereas the formation of free radicals, lipid peroxidation and protein carbonylation were increased, suggesting oxidative stress. 4These results are similar to those described after the intramuscular administration of glycerol. Therefore, it is possible that glycerol may provoke renal lesions by mechanisms other than those induced by rhabdomyolysis. [source] | ||||||||||||||||||||||||||||