INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 6 2006
Viroj Wiwanitkit
Summary There is a particular concern with toluene because some research has indicated that toluene exposure could result in chronic toxicity including mutagenesis and carcinogenesis. This study aimed to determine the rate of sister chromatid exchanges (SCE), a marker for genotoxicity, and its correlation to the classical urine biomarker for toluene exposure, urine hippuric acid, among a sample of Thai exposed subjects. A total of 26 police (all males) were included in this study. The average (mean ± SD) urine hippuric acid level in these police was 0.8 ± 0.4 mg/g creatinine. The average (mean ± SD) SCE level in these police was 4.5 ± 1.0/cell. The average SCE among the police with high urine hippuric acid levels was non-significantly higher than the average SCE level of those without (P = 0.41). This implies that the cytogenetic response to toluene was not different between the subjects with and without high toluene exposure. High exposure to toluene seems not to be related to high SCE. [source]

Quantification of the expression level of integrin receptor ,v,3 in cell lines and MR imaging with antibody-coated iron oxide particles

MAGNETIC RESONANCE IN MEDICINE, Issue 4 2006
Sabrina Benedetto
Abstract Targeted imaging requires site-specific accumulation of a contrast agent (CA), and the properties of that agent must be selected according to the abundance of the target to obtain a signal above the detection limit of the instrument. However, numerical estimates of receptors per cell are rarely found in the literature. Integrin receptors would be particularly promising targets because of their accessibility from the blood stream and expression on activated neovascular endothelial cells. We systematically estimated the number of integrin receptors of cell lines and primary cells by flow cytometry analysis. Since integrin receptors are heterodimeric molecules, and ,v forms complexes with various , subunits, the numbers of ,v and ,3 subunits are therefore dissimilar. The observed values are 3 · 103,1.4 · 104/cell for ,v, and 5.3 · 102,1.1 · 104/cell for ,3. Despite the low number of exposed receptors, we show that up to single-cell MR visualization can be achieved with the use of iron oxide beads complexed with antibodies as CAs. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc. [source]

Aberrant DNA methylation in contrast with mutations

CANCER SCIENCE, Issue 2 2010
Toshikazu Ushijima
Aberrant DNA methylation is known as an important cause of human cancers, along with mutations. Although aberrant methylation was initially speculated to be similar to mutations, it is now recognized that methylation is quite unlike mutations. Whereas the number of mutations in individual cancer cells is estimated to be ,80, that of aberrant methylation of promoter CpG islands reaches several hundred to 1000. Although mutations of a specific gene are very few in non-cancerous (thus polyclonal) tissues (usually at 1 × 10,5/cell), aberrant methylation of a specific gene can be present up to several 10% of cells. Mutagenic chemicals and radiation are well-known inducers of mutations, whereas chronic inflammation is deeply involved in methylation induction. Although mutations are induced in mostly random genes, methylation is induced in specific genes depending on tissues and inducers. Methylation is potentially reversible, unlike mutations. These characteristics of methylation are opening up new fields of application and research. (Cancer Sci 2009) [source]

DEVELOPMENT OF A BINOCULAR TYPE SIX-COMPONENT LOAD CELL

EXPERIMENTAL TECHNIQUES, Issue 1 2003
D.I. Kang
First page of article [source]

ASSESSING ABSORBABILITY OF BIOACTIVE COMPONENTS IN ALOE USING IN VITRO DIGESTION MODEL WITH HUMAN INTESTINAL CELL

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2010
SOON-MI SHIM
ABSTRACT This study used a simulated in vitro digestion model coupled with caco-2 cell to assess the digestive stability and absorption of aloin, aloe-emodin and aloenin A. Aloenin A and aloe-emodin were stable and entirely recovered during simulated digestion, but 50% of aloin was lost. Approximately 53.2, 7.3 and 28.7% of aloe-emodin, aloenin A and aloin, respectively, was transported into both apical and basolateral compartments after 1 h incubation in caco-2 cell. The involvement of several transporter proteins for aloin and aloenin A was examined. An inhibitor of SGLT1 on apical surface (phloridzin) or that of GLUT2 on basolateral membrane (cytochalasin B) reduced the absorption of aloin by 40 or 60%, respectively, indicating that aloin is likely to be a partial substrate of SGLT1. In the presence of an efflux transporter inhibitor (verapamil), the transport of aloenin A through an intentinal apical membrane increased up to 2.1 times compared with the control (without verapamil). PRACTICAL APPLICATIONS Our results on both digestive stability and intestinal absorption characteristics of bioactive components in aloe could be of helpful information for promoting its bioavailability. The in vitro technique described in this study provides a rapid and cost-effective alternative for predicting bioavailability of biomarkers in aloe functional food. [source]

REGENERATION OF A CELL FROM PROTOPLASM

JOURNAL OF PHYCOLOGY, Issue 1 2006
ARTHUR GROSSMAN
First page of article [source]

THE MIRACLE OF THE CELLS: AN EXPERIMENTAL STUDY OF INTERVENTIONS TO INCREASE PAYMENT OF COURT-ORDERED FINANCIAL OBLIGATIONS,

CRIMINOLOGY AND PUBLIC POLICY, Issue 1 2008
DAVID WEISBURD
Research Summary: In this article, we present findings from an experimental study of an innovative program in fine enforcement developed by the Administrative Office of the Courts (AOC) of New Jersey, termed Project MUSTER (MUST Earn Restitution). The project was initiated by the New Jersey AOC as a response to concerns among probation personnel that probationers sentenced to monetary penalties often failed to meet their financial obligations. The program sought to increase payment of court-ordered financial obligations among probationers who are seriously delinquent in paying fines, penalties, and restitution, and was designed to "strengthen the effectiveness of restitution and fine sanctions by forcing those offenders who have the ability to make regular payments to do so." Project MUSTER relied on a combination of intensive probation, threats of violation to court and incarceration, and community service. We find that probationers sentenced to Project MUSTER were significantly more likely to pay court-ordered financial obligations than were those who experienced regular probation supervision. However, probationers sentenced to a second treatment group, in which the only intervention was violation of probation (one part of the MUSTER program), had similar outcomes to the MUSTER condition. These findings suggest that the main cause of fine payment was a deterrent threat of possible incarceration, which is often termed the "miracle of the cells." Policy Implications: Our study shows that it is possible to gain greater compliance with court-ordered financial obligations and that such compliance may be gained with a relatively simple and straightforward criminal justice intervention. Threats of violation of probation are an effective tool for gaining compliance with financial obligations. Given the growing interest in monetary penalties as an alternative to incarceration, these findings have particular policy importance. [source]

THOUGHTS ON THE BROADER IMPLICATIONS OF THE "MIRACLE OF THE CELLS"

CRIMINOLOGY AND PUBLIC POLICY, Issue 1 2008
DANIEL S. NAGIN
First page of article [source]

FOAM CELLS IN NIPPLE ASPIRATION FLUID

CYTOPATHOLOGY, Issue 1 2002
S. Krishnamurthy
No abstract is available for this article. [source]

MULTIPLE HIV-1 INFECTION OF CELLS AND THE EVOLUTIONARY DYNAMICS OF CYTOTOXIC T LYMPHOCYTE ESCAPE MUTANTS

EVOLUTION, Issue 9 2009
Dominik Wodarz
Cytotoxic T lymphocytes (CTL) are an important branch of the immune system, killing virus-infected cells. Many viruses can mutate so that infected cells are not killed by CTL anymore. This escape can contribute to virus persistence and disease. A prominent example is HIV-1. The evolutionary dynamics of CTL escape mutants in vivo have been studied experimentally and mathematically, assuming that a cell can only be infected with one HIV particle at a time. However, according to data, multiple virus particles frequently infect the same cell, a process called coinfection. Here, we study the evolutionary dynamics of CTL escape mutants in the context of coinfection. A mathematical model suggests that an intermediate strength of the CTL response against the wild-type is most detrimental for an escape mutant, minimizing overall virus load and even leading to its extinction. A weaker or, paradoxically, stronger CTL response against the wild-type both lead to the persistence of the escape mutant and higher virus load. It is hypothesized that an intermediate strength of the CTL response, and thus the suboptimal virus suppression observed in HIV-1 infection, might be adaptive to minimize the impact of existing CTL escape mutants on overall virus load. [source]

A COMPLEXITY DRAIN ON CELLS IN THE EVOLUTION OF MULTICELLULARITY

EVOLUTION, Issue 3 2002
Daniel W. McShea
Abstract A hypothesis has been advanced recently predicting that, in evolution, as higher-level entities arise from associations of lower-level organisms, and as these entities acquire the ability to feed, reproduce, defend themselves, and so on, the lower-level organisms will tend to lose much of their internal complexity (McShea 2001a). In other words, in hierarchical transitions, there is a drain on numbers of part types at the lower level. One possible rationale is that the transfer of functional demands to the higher level renders many part types at the lower level useless, and thus their loss in evolution is favored by selection for economy. Here, a test is conducted at the cell level, comparing numbers of part types in free-living eukaryotic cells (protists) and the cells of metazoans and land plants. Differences are significant and consistent with the hypothesis, suggesting that tests at other hierarchical levels may be worthwhile. [source]

FREE RADICAL-SCAVENGING ACTIVITIES OF LOW MOLECULAR WEIGHT CHITIN OLIGOSACCHARIDES LEAD TO ANTIOXIDANT EFFECT IN LIVE CELLS

JOURNAL OF FOOD BIOCHEMISTRY, Issue 2010
DAI-NGHIEP NGO
ABSTRACT Chitin oligosaccharides (NA-COS) with low molecular weight distribution of 229.21,593.12 Da were produced from crab chitin by acid hydrolysis. They showed reducing power and scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) (Sigma Chemical Co., St. Louis, MO), hydroxyl and alkyl radicals. It was observed that the radical-scavenging activity of NA-COS increased in a dose-dependent manner. Their IC50 values for DPPH, hydroxyl and alkyl radicals were 0.8, 1.75 and 1.14 mg/mL, respectively. Furthermore, NA-COS exhibited the inhibitory effect on the oxidative damage of DNA from human lymphoma U937 (American Type Culture Collection, Manassas, VA) and the direct radical-scavenging effect in human fibrosarcoma cells (HT1080) (American Type Culture Collection) in 2,,7,-dichlorofluorescin diacetate (DCFH-DA) assay (Molecular Probes Inc., Eugene, OR). The results suggest that NA-COS can exert antioxidant effect in live cells and have the potential to be applied to food supplements or nutraceuticals. PRACTICAL APPLICATIONS Chitin oligosaccharides (NA-COS) are the hydrolyzed products of chitin (KEUMHO chemical products Co. Ltd., Gyeongbuk, Korea) of which derivatives have shown antioxidant, antimicrobial, anticancer, anti-inflammatory and immunostimulant effects. According to previous studies, NA-COS have beneficial biological activities similar to those of chitin. Furthermore, they are easily soluble in water because of their shorter chain length. Therefore, NA-COS are potentially applicable to improve food quality and human health. [source]

EVALUATION OF CELLS OF LACTOBACILLUS DELBRUECKII SPP.

JOURNAL OF FOOD QUALITY, Issue 6 2003
5 AND PEDIOCOCCUS ACIDILACTICI D3 SUSPENDED IN LACTIC OR ACETIC ACID AS BIOPRESERVATIVES ON FRESH CUT CANTALOUPE AT 7C, LACTIS RM
A small although statistically significant (P < 0.05) inactivation of S. choleraesuis was observed when cantaloupe cubes were additionally inoculated with cells P. acidilactici suspended in 5.5 mM lactic acid or 5.5 mM glacial acetic acid solutions. However, the numbers of S. choleraesuis were not significantly lower than in the control on day 10. The amount of inactivation likely would have no practical importance. No significant decline in numbers of S. choleraesuis was attained when the cells of L. delbrueckii spp. lactis were suspended in 5.5 mM lactic acid. None of the treatments contributed to an effective (P > 0.05) inhibition of the spoilage flora on the melons. [source]

GROWTH INHIBITION OF CLOSTRIDIUM PERFRINGENS VEGETATIVE CELLS AND SPORES USING CHICKEN IMMUNOGLOBULIN Y

JOURNAL OF FOOD SAFETY, Issue 4 2009
MIN S. SONG
ABSTRACT Egg yolk antibody (IgY) was isolated by the water dilution method from the egg yolk of chickens immunized with Clostridium perfringens vegetative cells and spores. Specific binding activity of IgY against C. perfringens vegetative cells and spores remained relatively high during the immunization period (up to 9 weeks). The titer of specific IgY against C. perfringens spores was 1.4-fold less than that of specific IgY against C. perfringens vegetable cells. The specific IgY powder (10 µg/mL) was found to inhibit the growth of C. perfringens vegetative cells or C. perfringens spores in a liquid medium. The difference of C. perfringens vegetative cell growth between the treatment and control groups was 8.9 × 106 colony forming units (cfu)/mL at 8 h of incubation and 9.95 × 107 cfu/mL at 24 h of incubation. Significant cfu reductions in C. perfringens spores were also observed with specific IgY powder at 24 h of incubation. PRACTICAL APPLICATIONS IgY antibody exerts an antimicrobial activity against pathogens by binding, immobilizing and consequently reducing or inhibiting the growth, replication or colony forming ability of pathogenic bacteria; thus, it is proved to be a viable alternative for antibiotics and preservatives. In this study, IgY against Clostridium perfringens can be used to replace chemical preservatives in food industries. Because IgY functions well at low temperature, it can be used to inhibit the growth of Clostridia which germinate in refrigerated storage conditions, thus preventing foodborne enterotoxicity caused by such bacteria. In practical applications, natural antimicrobial IgY antibody can be applied to meat products for the improvement of food safety. [source]

VIRULENCE LEVELS OF BIOFILM-GROWN LISTERIA MONOCYTOGENES LO28 ARE LOWER THAN THOSE OF PLANKTONIC CELLS IN AN ORAL INOCULATION TEST ON MICE

JOURNAL OF FOOD SAFETY, Issue 1 2007
ETIENNE ZUNDEL
ABSTRACT The aim of this study was to produce Listeria monocytogenes biofilms suitable for virulence assays and to determine whether the released bacteria had the same virulence potential as their planktonic counterparts. Biofilms of Listeria monocytogenes LO28 strain, with or without Sphingomonas paucimobilis CCL10 strain, containing up to 7 log10 cfu/cm2 were produced in polypropylene syringes. The virulence of strain LO28 was analyzed in mice after intravenous, subcutaneous and oral inoculation. Its virulence level in binary cultures was not significantly different from that of monocultures. L. monocytogenes LO28 virulence in biofilms was lower than that of their planktonic counterparts after oral inoculation. Our results suggest that biofilms pose no greater health risk to the consumer than planktonic bacteria. [source]

MEASUREMENT OF IN SITU SPECIFIC GROWTH RATES OF MICROCYSTIS (CYANOBACTERIA) FROM THE FREQUENCY OF DIVIDING CELLS,

JOURNAL OF PHYCOLOGY, Issue 5 2009
Yoshimasa Yamamoto
Diel changes in the frequency of dividing cells (FDC) of three Microcystis species were investigated in a small eutrophic pond from July to October 2005. The representative species was M. aeruginosa (Kütz.) Kütz., constituting 57%,86% of the Microcystis population throughout the study period, and the remainder were M. viridis (A. Braun) Lemmerm. and M. wesenbergii (Komárek) Komárek. The FDC of M. aeruginosa and M. wesenbergii increased in the daytime and fell in the nighttime in July and August, but this regular variation was not observed in September or October. The in situ specific growth rates of Microcystis species were estimated based on the assumption that the specific growth rate can be given as an absolute value of the derivative of FDC with respect to time. The calculated values were similar among species,0.15,0.38 · d,1 for M. aeruginosa, 0.14,0.63 · d,1 for M. viridis, and 0.18,0.61 · d,1 for M. wesenbergii. The specific growth rates in July and August slightly exceeded those in September and October. The analysis of the in situ specific growth rate of Microcystis indicated that recruitment of the benthic population or morphological change, rather than massive growth, was at least partly responsible for the dominance of M. aeruginosa in the study pond. [source]

PHYLOGENY OF FOUR DINOPHYSIACEAN GENERA (DINOPHYCEAE, DINOPHYSIALES) BASED ON rDNA SEQUENCES FROM SINGLE CELLS AND ENVIRONMENTAL SAMPLES,

JOURNAL OF PHYCOLOGY, Issue 5 2009
Sara M. Handy
Dinoflagellates are a highly diverse and environmentally important group of protists with relatively poor resolution of phylogenetic relationships, particularly among heterotrophic species. We examined the phylogeny of several dinophysiacean dinoflagellates using samples collected from four Atlantic sites. As a rule, 3.5 kb of sequence including the nuclear ribosomal genes SSU, 5.8S, LSU, plus their internal transcribed spacer (ITS) 1 and 2 regions were determined for 26 individuals, including representatives of two genera for which molecular data were previously unavailable, Ornithocercus F. Stein and Histioneis F. Stein. In addition, a clone library targeting the dinophysiacean ITS2 and LSU sequences was constructed from bulk environmental DNA from three sites. Three phylogenetic trees were inferred from the data, one using data from this study for cells identified to genus or species (3.5 kb, 28 taxa); another containing dinoflagellate SSU submissions from GenBank and the 12 new dinophysiacean sequences (1.9 kb, 56 taxa) from this study; and the third tree combing data from identified taxa, dinophysiacean GenBank submissions, and the clone libraries from this study (2.1 kb, 136 taxa). All trees were congruent and indicated a distinct division between the genera Phalacroma F. Stein and Dinophysis Ehrenb. The cyanobionts containing genera Histioneis and Ornithocercus were also monophyletic. This was the largest molecular phylogeny of dinophysoid taxa performed to date and was consistent with the view that the genus Phalacroma may not be synonymous with Dinophysis. [source]

CRYOPRESERVATION OF THE GAMETOPHYTIC CELLS OF LAMINARIALES (PHAEOPHYTA) IN LIQUID NITROGEN,

JOURNAL OF PHYCOLOGY, Issue 3 2004
Kazuyoshi Kuwano
The gametophytic cells of six species of Laminariales, Laminaria japonica Areschoug, L. longissima Miyabe, Kjellmaniella crassifolia Miyabe, Ecklonia stolonifera Okamura, E. kurome Okamura, and Undaria pinnatifida (Harvey) Suringar, were subjected to cryopreservation in liquid nitrogen. The cells were suspended in various cryoprotective solutions and slowly cooled to ,40°C over a period of 4 h. After this slow cooling step, the suspensions were immediately immersed in liquid nitrogen. All the species of Laminariaceae used in the present study survived maximally in a mixture of ethylene glycol and proline. On the other hand, the gametophytic cells of Undaria pinnatifida, a member of the Alariaceae, survived maximally in the mixture of glycerol and proline. The viability of the thawed gametophytic cells decreased during postthawing incubation. The decrease in viability continued for 4,6 days, and the minimum levels ranged from 36.2% to 67.2%. After 4,6 days of incubation, the percentage viability of all strains began to increase due to the renewal of cell division. [source]

HIGH-RESOLUTION MAGIC ANGLE SPINNING NMR ANALYSIS OF WHOLE CELLS OF CHAETOCEROS MUELLERI (BACILLARIOPHYCEAE) AND COMPARISON WITH 13C-NMR AND DISTORTIONLESS ENHANCEMENT BY POLARIZATION TRANSFER 13C-NMR ANALYSIS OF LIPOPHILIC EXTRACTS,

JOURNAL OF PHYCOLOGY, Issue 3 2004
Matilde S. Chauton
Lipid composition in extracted samples of Chaetoceros muelleri Lemmermann was studied with 13C-NMR and distortionless enhancement by polarization transfer (DEPT) 13C-NMR, resulting in well-resolved 13C-NMR spectra with characteristic resonance signals from carboxylic, olefinic, glyceryl, methylene, and methyl groups. The application of a DEPT pulse sequence aided in the assignment of methylene and methine groups. Resonance signals were compared with literature references, and signal assignment included important unsaturated fatty acids such as eicosapentaenoic and docosahexaenoic and also phospholipids and glycerols. Results from the extracted samples were used to assign resonance signals in a high-resolution magic angle spinning (HR MAS) DEPT 13C spectrum from whole cells of C. muelleri. The NMR analysis on whole cells yielded equally good information on fatty acids and also revealed signals from carbohydrates and amino acids. Broad resonance signals and peak overlapping can be a problem in whole cell analysis, but we found that application of HR MAS gave a well-resolved spectrum. The chemical shift of metabolites in an NMR spectrum depends on the actual environment of nuclei during analysis, and some differences could therefore be expected between extracted and whole cell samples. The shift differences were small, and assignment from analysis of lipophilic extract could be used to identify peaks in the whole cell spectrum. HR MAS 13C-NMR therefore offers a possibility for broad-range metabolic profiling directly on whole cells, simultaneously detecting metabolites that are otherwise not detected in the same analytical set up and avoiding tedious extraction procedures. [source]

RELATIONSHIPS BETWEEN PRIMARY PLANT CELL WALL ARCHITECTURE AND MECHANICAL PROPERTIES FOR ONION BULB SCALE EPIDERMAL CELLS

JOURNAL OF TEXTURE STUDIES, Issue 6 2004
DAVID G. HEPWORTH
ABSTRACT This article investigates onion epidermal tissue (Allium cepa) using a combination of mechanical testing, microscopy and modeling and relates tissue mechanical properties to the known structure of the cell walls. Onion epidermal tissue has a simple, regular structure of elongated cells, which have been used to enable the contributions to mechanical properties of cell walls and of higher order structures to be separated and analyzed. Two models of wall behavior were used to explore how Poisson's ratio of cell walls parallel to the plane of the epidermal surface may vary with applied strain. In the first model, cellulose microfibrils can be reorientated in an unrestricted way with the result that the cell wall volume decreases. In the second model the volume of the cell wall remains constant, which controls the reorientation of microfibrils, hence the Poisson's ratio. Measurements made from uniaxially stretched cells show that the data most closely fits model I, therefore, it is concluded that the bulk of the matrix has little influence on the observed mechanical properties (at a test rate of 1 mm/min), allowing cellulose microfibrils to reorient through the matrix in an unrestricted way during uniaxial tests. In its mechanical attributes the primary cell wall resembles more a knitted cloth than a semisolid composite material. When biaxial stretching is applied to tissue, so that there is no re-orientation of microfibrils, the cell wall material is still able to reach surprisingly large elastic strains of up to 12.5% and no plastic deformation was recorded. Current theory suggests that cellulose microfibrils can stretch elastically by a maximum of 7%, therefore further work is required to identify mechanisms that could account for the extra elastic strain. [source]

NERVE GROWTH FACTOR RESCUE OF CISPLATIN NEUROTOXICITY IS MEDIATED THROUGH THE HIGH AFFINITY RECEPTOR: STUDIES IN PC12 CELLS AND P75 NULL MOUSE DORSAL ROOT GANGLIA

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2002
SJ Fischer
Nerve growth factor (NGF) rescues dorsal root ganglion neurons and PC12 cells from cisplatin-induced cell death. Two model systems were used to demonstrate that rescue is mediated through the high affinity NGF receptor. In dorsal root ganglion (DRG) neurons isolated from p75(,/,) and control mice, 20 ng/ml NGF completely prevented cisplatin-induced death. In PC12 cells, we overexpressed receptor chimeras between the tumor necrosis factor and NGF receptors. We demonstrated that activation of the intracellular domain of Trk A is responsible for the NGF rescue effect. [source]

THE CONNEXIN 32 NERVE-SPECIFIC PROMOTER IS DIRECTLY ACTIVATED BY Egr2/Krox20 IN HeLa CELLS

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2002
M. Musso
Connexin 32 (Cx32) belongs to a protein family that forms intercellular channels mediating the exchange of ions and chemical messengers. In the peripheral nervous system (PNS) Cx32 is expressed in Schwann cells and contributes to the homeostasis and structural integrity of myelin. Mutations of this gene determine X-linked form of Charcot Marie-Tooth (CMTX) disease. Cx 32 is transcriptionally regulated in a tissue-specific manner by two different promoters termed P1 and P2. P2, active in Schwann cells, is located 5 kb downstream from the P1 promoter and at 500 bp from the exon 2 that contains the entire coding region. Previously, by Electrophoretical Mobility Shift Assay (EMSA) we have identified a sequence (-101/-93), within P2, specifically recognized by recombinant Egr2. In order to prove the direct involvement of Egr2 in the transcriptional control of the Cx32 gene, we have performed transfection experiments in HeLa cells with a luciferase driven by the P2 promoter in presence or not of a vector expressing Krox20, the mouse homologue of human Egr2. We have found that the construct in which the sequence -103/-93 is mutated is not activated as well as the wild type sequence. Moreover we have detected another upstream sequence (-236/-213) recognized by recombinant Egr2 and other transcription factors present in HeLa nuclear extract like SP1. The construct, lacking this sequence and carrying the mutated downstream Egr2 recognition sequence, is not activated at all by Krox20. Taken together these findings strongly suggest the role of Egr2 in the transcriptional control of Connexin 32 through both sequences. The laboratory is a member of the European CMT Consortium; partially granted by Ministero della Sanit, to PM, MURST and Ateneo to FA. [source]

PARATHYROID HORMONE HAS A PROSCLEROTIC EFFECT ON VASCULAR SMOOTH MUSCLE CELLS

NEPHROLOGY, Issue 1 2002
Vlado Perkovic
[source]

THERAPY WITH mAb TO CD25 BLOCKS FUNCTION OF CD4+, CD25+ T REGULATORY CELLS WHICH MAINTAIN TRANSPLANTATION TOLERANCE

NEPHROLOGY, Issue 1 2002
Hall Bm
[source]

FAS LIGAND TRANSFECTION OF RENAL TUBULAR CELLS INDUCES APOPTOSIS OF ACTIVATED LEUCOCYTES

NEPHROLOGY, Issue 3 2000
Wang Yp
[source]

ADDRESS OF HIS HOLINESS POPE BENEDICT XVI TO PARTICIPANTS OF THE SYMPOSIUM ON THE THEME: ,STEM CELLS: WHAT FUTURE FOR THERAPY?

CELL PROLIFERATION, Issue 2008
SCIENTIFIC ASPECTS AND BIOETHICAL PROBLEMS'
No abstract is available for this article. [source]

PIOGLITAZONE INHIBITS HOMOCYSTEINE-INDUCED MIGRATION OF VASCULAR SMOOTH MUSCLE CELLS THROUGH A PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ,-INDEPENDENT MECHANISM

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 12 2008
Li Li
SUMMARY 1Peroxisome proliferator-activated receptor (PPAR)-, agonists have been demonstrated to exert protective effects against homocysteine (Hcy)-induced pathogenesis. However, the effects of PPAR-, agonists on Hcy-induced migration are unknown. In the present study, we examined the effect of pioglitazone on the migration of vascular smooth muscle cells (VSMC) induced by Hcy and the possible mechanism involved. 2Vascular smooth muscle cells were isolated from the thoracic aortas of male Sprague-Dawley rats. The migration of VSMC was examined using a transwell technique. The generation of intracellular reactive oxygen species (ROS) was measured using the ROS-sensitive fluoroprobe 2,,7,-dichlorodihydrofluorescein diacetate. The activity of NAD(P)H oxidase was assessed by lucigenin enhanced chemiluminescence. Activation of p38 mitogen-activated protein kinase (MAPK) was determined by western blotting. 3The results showed that pioglitazone dose-dependently inhibited the migration of VSMC induced by Hcy. This was not reversed by the PPAR-, antagonist GW9662. In addition, pretreatment with the NAD(P)H oxidase inhibitor diphenylene iodonium (DPI), the free radical scavenger N -acetylcysteine and the p38 MAPK inhibitor SB202190 blocked Hcy-induced VSMC migration. Furthermore, we observed that pioglitazone suppressed Hcy-induced intracellular ROS production; similar effects were observed with DPI and NAC. Pioglitazone attenuated Hcy-induced activation of NAD(P)H oxidase. Moreover, pioglitazone blocked Hcy-induced p38 MAPK phosphorylation; similar effects were observed for DPI, NAC and SB202190. 4The data demonstrate that pioglitazone inhibits Hcy-induced VSMC migration that is independent of PPAR-,. Furthermore, part of the biological effect of pioglitazone involves a decrease in the levels of NAD(P)H oxidase derived-ROS and p38 MAPK activation. [source]

INVOLVEMENT OF BOTH ENDOPLASMIC RETICULUM- AND MITOCHONDRIA-DEPENDENT PATHWAYS IN CARDIOTOXIN III-INDUCED APOPTOSIS IN HL-60 CELLS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2008
Ching-Ming Chien
SUMMARY 1Cardiotoxin (CTX) III, a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom, has been reported to have anticancer activity. In the present study, we investigated the mechanisms underlying the anticancer activity of CTX III in human leukaemia (HL-60 cells). 2Cardiotoxin III activated the endoplasmic reticulum (ER) pathway of apoptosis in HL-60 cells, as indicated by increased levels of calcium and glucose-related protein 78 (Grp78), and triggered the subsequent activation of µ-calpain and caspase 12. 3In addition, CTX III initiated the mitochondrial apoptotic pathway in HL-60 cells, as evidenced by an increased Bax/Bcl-2 ratio, the release of cytochrome c and activation of caspase 9. 4In the presence of 50 µmol/L Z-ATAD-FMK (a caspase 12 inhibitor) and 100 µmol/L Z-LEHD-FMK (a caspase 9 inhibitor), the CTX III-mediated activation of caspase 9 and caspase 3 was significantly reduced. There was no significant effect of the caspase 12 inhibitor Z-ATAD-FMK on mitochondrial cytochrome c release. 5Cardiotoxin III-mediated activation of caspase 12 was not abrogated in the presence of the caspase 9 inhibitor Z-LEHD-FMK, indicating that caspase 12 activation was not downstream of caspase 9. 6These results indicate that CTX III induces cell apoptosis via both ER stress and a mitochondrial death pathway. [source]

STIMULATION OF OESTROGEN RECEPTOR-EXPRESSING ENDOTHELIAL CELLS WITH OESTROGEN REDUCES PROLIFERATION OF COCULTURED VASCULAR SMOOTH MUSCLE CELLS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 3 2008
Malin 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]

EFFECT OF HYDROGEN SULPHIDE ON ,-AMYLOID-INDUCED DAMAGE IN PC12 CELLS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 2 2008
Xiao-Qing Tang
SUMMARY 1Hydrogen sulphide (H2S) is a well-known cytotoxic gas. Recently, H2S has been shown to protect neurons against oxidative stress caused by glutamate, peroxynitrite and HOCl. Considerably lower H2S levels have been reported in the brain of Alzheimer's disease (AD) patients with accumulation of ,-amyloid (A,). 2The aim of present study was to explore the cytoprotection by H2S against A,25,35 -induced apoptosis and the molecular mechanisms underlying this effect in PC12 cells. 3Our findings indicated that A,25,35 significantly reduced cell viability and induced apoptosis of PC12 cells, along with dissipation of the mitochondrial membrane potential (MMP) and overproduction of reactive oxygen species (ROS). 4Sodium hydrosulphide (NaHS), an H2S donor, protected PC12 cells against A,25,35 -induced cytotoxicity and apoptosis not only by reducing the loss of MMP, but also by attenuating the increase in intracellular ROS. 5The results of the present study suggest that the cytoprotection by H2S is related to the preservation of MMP and attenuation of A,25,35 -induced intracellular ROS generation. These findings could significantly advance therapeutic approaches to the neurodegenerative diseases that are associated with oxidative stress, such as AD. [source]