Normal Conditions (normal + condition)

Distribution by Scientific Domains


Selected Abstracts


Infant Affect During Parent,Infant Interaction at 3 and 6 Months: Differences Between Mothers and Fathers and Influence of Parent History of Depression

INFANCY, Issue 1 2004
Erika E. Forbes
Fifty families participated in mother-infant and father-infant still-face interaction at infant ages 3 and 6 months as part of a study of affect in early parent-infant relationships. Infants' positive and negative affect and parents' positive affect and physical play were coded from videotapes. Consistent with previous research, during the normal condition, mothers displayed more positive affect than did fathers, and fathers were more likely than mothers to display physical play. Infants were more positive with mothers than with fathers. Parents' positive affect but not parent gender predicted infants' positive affect at 6 months. During the still-face condition, infants of parents with a lifetime history of depression were more likely to display negative affect and less likely to display positive affect than infants with no such parent history. Infants' affect was unrelated to parents' current level of depressive symptoms, which indicates the value of considering family history of psychopathology when examining individual differences in infants' affect. [source]


Magnetic Resonance Imaging of the Hypothalamic-Neurohypophyseal System

JOURNAL OF NEUROENDOCRINOLOGY, Issue 4 2004
I. Fujisawa
Abstract Magnetic resonance imaging (MRI) is a revolutionary advance in diagnostic imaging of the hypothalamic-neurohypophyseal system (HNS). The detailed anatomy of the sellar and parasellar region is clearly visible using MRI, because it has no bony artifacts and multidirectional capability. The posterior lobe of the pituitary gland displays a characteristic bright signal on the MR T1-weighted image (T1WI), and is distinctly separated from the anterior lobe. The bright signal is absent in patients with central diabetes insipidus, and is thought to reflect normal vasopressin storage in the posterior lobe. The signal intensity ratio of the posterior lobe to the pons on T1WI is strongly correlated with vasopressin content in the posterior lobe. In addition to the morphological evaluation, MRI provides unique information concerning the function of the HNS. The MRI findings of the HNS (normal condition, central diabetes insipidus, a depleted posterior lobe, an ectopic posterior lobe, and a damming-up phenomenon of the neurosecretory vesicles in the pituitary stalk) are demonstrated in this article. [source]


Evodia rutaecarpa protects against circulation failure and organ dysfunction in endotoxaemic rats through modulating nitric oxide release

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2002
Wen Fei Chiou
Using a rat model of septic shock we studied the effects of Evodia rutaecarpa, a Chinese herbal medicine with antimicrobial and anti-inflammatory activity, on haemodynamic parameters, biochemical markers of organ function and nitric oxide (NO) production. Anaesthetized rats challenged with a high dosage of endotoxin (Escherichia coli lipopolysaccharide; LPS; 50 mg kg,1, i.v.) for 6 h showed a severe decrease in mean arterial pressure. This was accompanied by delayed bradycardia, vascular hyporeactivity to phenylephrine and increase in plasma levels of lactate dehydrogenase, aspartate aminotransferase, bilirubin and creatinine, as well as NOx (NO,2 plus NO,3). Pretreatment with ethanol extract of E. rutaecarpa (25,50 and 100 mg kg,1, i.v.), 1 h before LPS, dose-dependently prevented the circulation failure, vascular hyporeactivity to phenylephrine, prevented liver dysfunction and reduced the NOx over-production in plasma in endotoxaemic rats. A selective inducible NO-synthase (iNOS) inhibitor, aminoguanidine (15 mg kg,1, i.v.), also effectively ameliorated the above pathophysiological phenomenon associated with endotoxaemia so that the normal condition was approached. Endotoxaemia for 6 h resulted in a significant increase in iNOS activity in the liver homogenate, which was attenuated significantly by E. rutaecarpa pretreatment. In summary, E. rutaecarpa, at the dosages used, exerted these beneficial effects probably through inhibition of iNOS activity and subsequent modulation of the release of NO. These significant results may offer E. rutaecarpa as a candidate for the treatment of this model of endotoxaemia. [source]


Transgenic rice hybrids that carry the Rf-1 gene at multiple loci show improved fertility at low temperature

PLANT CELL & ENVIRONMENT, Issue 4 2005
TOSHIYUKI KOMORI
ABSTRACT By using a genomic fragment that carries the rice (Oryza sativa L.) fertility restorer gene, Rf-1, rice restorer lines harbouring multiple Rf-1 genes on different chromosomes were developed by genetic engineering and crossing. Hybrid lines that were obtained by crossing the restorer lines having two and three Rf-1 genes with a cytoplasmic male sterile (CMS) line had nearly 75 and 87.5% pollen fertility rates under a normal condition, respectively, whereas a conventional hybrid line showed a 50% pollen fertility rate. Furthermore, the seed set percentage under low temperature conditions was much higher in the hybrid lines with multiple Rf-1 genes than the conventional hybrid line. These results indicate that multiplication of the Rf-1 gene conferred cold tolerance at the booting stage to hybrid rice through increasing the potentially fertile pollen grains. This strategy to improve fertility at low temperature of hybrids could be applied to any grain crops that are developed based on CMS and its gametophytic restorer gene, let alone rice. [source]


Reliable State Feedback Control Synthesis For Uncertain Linear Systems

ASIAN JOURNAL OF CONTROL, Issue 2 2003
Guang-Hong Yang
ABSTRACT This paper is concerned with the problem of designing reliable state- feedback control for a class of uncertain linear systems with norm bounded uncertainty. A procedure for designing reliable state-feedback control is presented for the case of actuator faults that can be modeled by a scaling factor. In the design, the performance of the normal system (without fault) is optimized, as the considered system operates under the normal condition most of the time. In addition, when actuator faults occur, the closed-loop system retains robust stability and satisfies a known quadratic performance bound. A numerical example is provided to illustrate the effectiveness of the proposed design method. [source]


Reserved Strength of Reinforced Concrete Buildings with Masonry Walls

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2005
Nasreddin S. El Mezaini
In this building, damage was limited to some cracks in the walls near the targeted zone. Other parts of the building remained intact. The building was analyzed using two different models. In one model, masonry walls were treated as nonstructural elements represented by applied loads. In the other model, walls were represented by membrane elements connected to concrete frames by link elements. Analysis was carried out for two cases, before and after damage. The study revealed that such buildings possess potential reserved strength. They have the ability to change their designated load path. The role of masonry walls is emphasized. In this case, masonry walls worked as a backup system that prevented major collapse of the building. It is estimated that, under normal conditions, masonry walls increase the building strength by 48%. [source]


Volume natriuresis vs. pressure natriuresis

ACTA PHYSIOLOGICA, Issue 4 2004
P. Bie
Abstract Body fluid regulation depends on regulation of renal excretion. This includes a fast vasopressin-mediated water-retaining mechanism, and slower, complex sodium-retaining systems dominated by the renin,angiotensin aldosterone cascade. The sensory mechanisms of sodium control are not identified; effectors may include renal arterial pressure, renal reflexes, extrarenal hormones and other regulatory factors. Since the pioneering work of Guyton more than three decades ago, pressure natriuresis has been in focus. Dissociations between sodium excretion and blood pressure are explained as conditions where regulatory performance exceeds the precision of the measurements. It is inherent to the concept, however, that sudden transition from low to high sodium intake elicits an arterial pressure increase, which is reversed by the pressure natriuresis mechanism. However, such transitions elicit parallel changes in extracellular fluid volume thereby activating volume receptors. Recently we studied the orchestration of sodium homeostasis by chronic and acute sodium loading in normal humans and trained dogs. Small increases in arterial blood pressure are easily generated by acute sodium loading, and dogs appear more sensitive than humans. However, with suitable loading procedures it is possible , also acutely , to augment renal sodium excretion by at least one order of magnitude without any change in arterial pressure whatsoever. Although pressure natriuresis is a powerful mechanism capable of overriding any other controller, it seems possible that it is not operative under normal conditions. Consequently, it is suggested that physiological control of sodium excretion is neurohumoral based on extracellular volume with neural control of renin system activity as an essential component. [source]


Myosin Va phosphorylated on Ser1650 is found in nuclear speckles and redistributes to nucleoli upon inhibition of transcription

CYTOSKELETON, Issue 6 2008
Maria Cristina S. Pranchevicius
Abstract Nuclear actin and nuclear myosins have been implicated in the regulation of gene expression in vertebrate cells. Myosin V is a class of actin-based motor proteins involved in cytoplasmic vesicle transport and anchorage, spindle-pole alignment and mRNA translocation. In this study, myosin-Va, phosphorylated on a conserved serine in the tail domain (phospho-ser1650 MVa), was localized to subnuclear compartments. A monoclonal antibody, 9E6, raised against a peptide corresponding to phosphoserine1650 and flanking regions of the murine myosin Va sequence, was immunoreactive to myosin Va heavy chain in cellular and nuclear extracts of HeLa cells, PC12 cells and B16-F10 melanocytes. Immunofluorescence microscopy with this antibody revealed discrete irregular spots within the nucleoplasm that colocalized with SC35, a splicing factor that earmarks nuclear speckles. Phospho-ser1650 MVa was not detected in other nuclear compartments, such as condensed chromatin, Cajal bodies, gems and perinucleolar caps. Although nucleoli also were not labeled by 9E6 under normal conditions, inhibition of transcription in HeLa cells by actinomycin D caused the redistribution of phospho-ser1650 MVa to nucleoli, as well as separating a fraction of phospho-ser1650 MVa from SC35 into near-neighboring particles. These observations indicate a novel role for myosin Va in nuclear compartmentalization and offer a new lead towards the understanding of actomyosin-based gene regulation. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source]


Glucose homeostasis and the gastrointestinal tract: insights into the treatment of diabetes

DIABETES OBESITY & METABOLISM, Issue 1 2008
D. Maggs
The gastrointestinal tract is increasingly viewed as a critical organ in glucose metabolism because of its role in delivering glucose to the circulation and in secreting multiple glucoregulatory hormones that, in concert with insulin and glucagon, regulate glucose homeostasis. Under normal conditions, a complex interplay of these hormones acts to maintain plasma glucose within a narrow range despite large variations in the availability of glucose, particularly during transition from the fasting to fed state. In the fed state, the rate at which nutrients are passed from the stomach to the duodenum, termed gastric emptying rate, is a key determinant of postprandial glucose flux. In patients with diabetes, the regulation of glucose metabolism is disrupted resulting in fasting and postprandial hyperglycaemia. Elucidation of the role of the gastrointestinal tract, gut-derived glucoregulatory peptides and gastric emptying rate offers a new perspective on glucose homeostasis and the respective importance of these factors in the diabetes state. This review will highlight the importance of the gastrointestinal tract in playing a key role in glucose homeostasis, particularly in the postprandial period, and the role of established or new therapies that either leverage or modify gastrointestinal function to improve glycaemic state. [source]


Phase Transformations During High-Pressure Torsion of Pure Zr and of a Zr-2.5%Nb Alloy,

ADVANCED ENGINEERING MATERIALS, Issue 8 2010
Alexander P. Zhilyaev
Zirconium at normal conditions (room temperature and atmospheric pressure) has an HCP structure with lattice parameters a,=,3.2313,Å and c,=,5.1477,Å (,-phase). During loading under hydrostatic conditions in diamond anvil cells, a transition from the , -phase to an , -phase occurs at a pressure between 2 and 6 GPa and from , to , (bcc) at 30 GPa. It has been recently reported that the , to ,,+,, transformation might be induced by HPT processing. The resulting microstructures are stable at room temperature and atmospheric pressure. This paper explores the influence of previous processing steps and of composition in the feasibility of the HPT induced , to ,,+,, transformation. It will be shown that neither previous quenching nor high temperature HPT processing prevents the transformation from occurring during subsequent room temperature HPT. The addition of elements such as Nb also seems to favor the transformation. Understanding well the potential of HPT to stabilize high-pressure phases at normal conditions might be critical, as it will open a whole new range of applications for already existing materials. [source]


Impact of S100B on local field potential patterns in anesthetized and kainic acid-induced seizure conditions in vivo

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2007
Seiichi Sakatani
Abstract S100B is a calcium-binding protein predominantly expressed in astrocytes. Previous studies using gene-manipulated animals have suggested that the protein has a role in synaptic plasticity and learning. In order to assess the physiological roles of the protein in active neural circuitry, we recorded spontaneous neural activities from various layers of the neocortex and hippocampus in urethane-anesthetized S100B knockout (KO) and wildtype (WT) control mice. Typical local field oscillation patterns including the slow (0.5,2 Hz) oscillations in the neocortex, theta (3,8 Hz) and sharp wave-associated ripple (120,180 Hz) oscillations in the hippocampus were observed in both genotypes. Comparisons of the frequency, power and peak amplitude have shown that these oscillatory patterns were virtually indistinguishable between WT and KO. When seizure was induced by intraperitoneal injection of kainic acid, a difference between WT and KO appeared in the CA1 radiatum local field potential pattern, where seizure events were characterized by prominent appearance of hyper-synchronous gamma band (30,80 Hz) activity. Although both genotypes developed seizures within 40 min, the gamma amplitude was significantly smaller during the development of seizures in KO mice. Our results suggest that deficiency of S100B does not have a profound impact on spontaneous neural activity in normal conditions. However, when neural activity was sufficiently raised, activation of S100B-related pathways may take effect, resulting in modulation of neural activities. [source]


Calcium-sensing receptor mediates phenylalanine-induced cholecystokinin secretion in enteroendocrine STC-1 cells

FEBS JOURNAL, Issue 18 2008
Tohru Hira
Intraluminal l -phenylalanine (Phe) stimulates cholecystokinin (CCK) secretion in vivo and in vitro. However, the cellular mechanism by which CCK-producing enteroendocrine cells sense Phe is unknown. The calcium-sensing receptor (CaR) can sense amino acids, and is expressed in the gastrointestinal tract. In the present study, we examined whether CaR functions as a receptor for Phe in CCK-producing enteroendocrine cells. CCK secretion and intracellular Ca2+ concentration in response to Phe were measured in the murine CCK-producing enteroendocrine cell line STC-1 at various extracellular Ca2+ concentrations or after treatment with a CaR antagonist. At more than 20 mm, Phe induced dose-dependent CCK secretion and intracellular Ca2+ mobilization in STC-1 cells. In the presence of 3.0 mm extracellular Ca2+, 10 and 20 mm Phe induced significantly higher CCK secretion than under normal conditions (1.2 mm extracellular Ca2+). Intracellular Ca2+ mobilization, induced by 10 or 20 mm Phe, was also enhanced by increasing extracellular Ca2+ concentrations. In addition, intracellular Ca2+ mobilization induced by addition of extracellular Ca2+ was augmented by the presence of Phe. These results closely match the known CaR properties. Treatment with a specific CaR antagonist (NPS2143) completely inhibited Phe-induced CCK secretion and the latter phase of intracellular Ca2+ mobilization. CaR mRNA expression was demonstrated by RT-PCR in STC-1 cells, as well as in other mouse tissues including the kidney, thyroid, stomach and intestine. In conclusion, CaR functions as a receptor for Phe, stimulating CCK secretion in enteroendocrine STC-1 cells. [source]


Regulated expression by PPAR, and unique localization of 17,-hydroxysteroid dehydrogenase type 11 protein in mouse intestine and liver

FEBS JOURNAL, Issue 18 2007
Yasuhide Yokoi
17,-Hydroxysteroid dehydrogenase type 11 (17,-HSD11) is a member of the short-chain dehydrogenase/reductase family involved in the activation and inactivation of sex steroid hormones. We recently identified 17,-HSD11 as a gene that is efficiently regulated by peroxisome proliferator-activated receptor-, PPAR, in the intestine and the liver [Motojima K (2004) Eur J Biochem271, 4141,4146]. In this study, we characterized 17,-HSD11 at the protein level to obtain information about its physiologic role in the intestine and liver. For this purpose, specific antibodies against 17,-HSD11 were obtained. Western blotting analysis showed that administration of a peroxisome proliferator-activated receptor-, agonist induced 17,-HSD11 protein in the jejunum but not in the colon, and to a much higher extent than in the liver of mice. A subcellular localization study using Chinese hamster ovary cells and green fluorescent protein-tagged 17,-HSD11 showed that it was mostly localized in the endoplasmic reticulum under normal conditions, whereas it was concentrated on lipid droplets when they were induced. A pulse-chase experiment suggested that 17,-HSD11 was redistributed to the lipid droplets via the endoplasmic reticulum. Immunohistochemical analysis using tissue sections showed that 17,-HSD11 was induced mostly in intestinal epithelia and hepatocytes, with heterogeneous localization both in the cytoplasm and in vesicular structures. A subcellular fractionation study of liver homogenates confirmed that 17,-HSD11 was localized mostly in the endoplasmic reticulum when mice were fed a normal diet, but was distributed in both the endoplasmic reticulum and the lipid droplets of which formation was induced by feeding a diet containing a proliferator-activated receptor-, agonist. Taken together, these data indicate that 17,-HSD11 localizes both in the endoplasmic reticulum and in lipid droplets, depending on physiologic conditions, and that lipid droplet 17,-HSD11 is not merely an endoplasmic reticulum contaminant or a nonphysiologically associated protein in the cultured cells, but a bona fide protein component of the membranes of both intracellular compartments. [source]


Simulation study of methemoglobin reduction in erythrocytes

FEBS JOURNAL, Issue 6 2007
Differential contributions of two pathways to tolerance to oxidative stress
Methemoglobin (metHb), an oxidized form of hemoglobin, is unable to bind and carry oxygen. Erythrocytes are continuously subjected to oxidative stress and nitrite exposure, which results in the spontaneous formation of metHb. To avoid the accumulation of metHb, reductive pathways mediated by cytochrome b5 or flavin, coupled with NADH-dependent or NADPH-dependent metHb reductases, respectively, keep the level of metHb in erythrocytes at less than 1% of the total hemoglobin under normal conditions. In this work, a mathematical model has been developed to quantitatively assess the relative contributions of the two major metHb-reducing pathways, taking into consideration the supply of NADH and NADPH from central energy metabolism. The results of the simulation experiments suggest that these pathways have different roles in the reduction of metHb; one has a high response rate to hemoglobin oxidation with a limited reducing flux, and the other has a low response rate with a high capacity flux. On the basis of the results of our model, under normal oxidative conditions, the NADPH-dependent system, the physiological role of which to date has been unclear, is predicted to be responsible for most of the reduction of metHb. In contrast, the cytochrome b5,NADH pathway becomes dominant under conditions of excess metHb accumulation, only after the capacity of the flavin,NADPH pathway has reached its limit. We discuss the potential implications of a system designed with two metHb-reducing pathways in human erythrocytes. [source]


The absence of ribonuclease H1 or H2 alters the sensitivity of Saccharomyces cerevisiae to hydroxyurea, caffeine and ethyl methanesulphonate: implications for roles of RNases H in DNA replication and repair

GENES TO CELLS, Issue 10 2000
Arulvathani Arudchandran
Background RNA of RNA-DNA hybrids can be degraded by ribonucleases H present in all organisms including the eukaryote Saccharomyces cerevisiae. Determination of the number and roles of the RNases H in eukaryotes is quite feasible in S. cerevisiae. Results Two S. cerevisiae RNases H, related to Escherichia coli RNase HI and HII, are not required for growth under normal conditions, yet, compared with wild-type cells, a double-deletion strain has an increased sensitivity to hydroxyurea (HU) and is hypersensitive to caffeine and ethyl methanesulphonate (EMS). In the absence of RNase H1, RNase H2 activity increases, and cells are sensitive to EMS but not HU and are more tolerant of caffeine; the latter requires RNase H2 activity. Cells missing only RNase H2 exhibit increased sensitive to HU and EMS but not caffeine Conclusions Mutant phenotypes infer that some RNA-DNA hybrids are recognized by both RNases H1 and H2, while other hybrids appear to be recognized only by RNase H2. Undegraded RNA-DNA hybrids have an effect when DNA synthesis is impaired, DNA damage occurs or the cell cycle is perturbed by exposure to caffeine suggesting a role in DNA replication/repair that can be either beneficial or detrimental to cell viability. [source]


Epo protects SOD2-deficient mouse astrocytes from damage by oxidative stress

GLIA, Issue 4 2006
Jing Liu
Abstract Erythropoietin (Epo) expression, which regulates erythropoiesis, has been shown in rat and mouse brain after hypoxia. A previous study from our laboratory showed that astrocytes from manganese-superoxide dismutase (SOD2) homozygous knockout (SOD2,/,) mice can survive under 5% O2, but not under normal aerobic conditions. However, the mechanism involved is not clear. Our preliminary study using reverse transcriptase-polymerase chain reaction showed increased Epo mRNA expression in astrocytes cultured with 5% hypoxia compared with astrocytes under normal conditions. After administration of anti-sense Epo, protection decreased with time. Dose-dependent administration of Epo to SOD2,/, mouse astrocytes improved their survivability under normal conditions. Survivability of heterozygous SOD2,/+ mutant and wild-type mouse astrocyte cultures was the same under normal conditions but, after administration of 2 mM of paraquat, a reactive oxygen species generator, survivability of the SOD2,/+ astrocytes decreased remarkably compared with the wild-type cells. Epo administration 24 h before exposure to paraquat significantly improved the survivability of the SOD2,/+ astrocytes. Western blot studies suggest that Jak-Stat signal transduction pathways are involved in this process. Our study demonstrates an important role for Epo in the protection of astrocytes from reactive oxygen species. We suggest that Epo can compensate in part for the antioxidant properties of mitochondrial SOD2 deficiency. © 2005 Wiley-Liss, Inc. [source]


Cover Picture: Tuning the Dimensions of C60 -Based Needlelike Crystals in Blended Thin Films (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 6 2006
Mater.
Abstract A new ordered structure of the C60 derivative PCBM is obtained in thin films based on the blend PCBM:P3HT, as detailed by Swinnen, Manca, and co-workers on p.,760. Needlelike crystalline PCBM structures, whose dimensions and spatial distribution ca be tuned by adjusting the blend ratio and annealing conditions, are formed. In typical solar-cell applications of these blended films, these results indicate that during long-term operation under normal conditions (50,70,°C) morphology changes and a decrease in cell performance could occur. A new ordered structure of the C60 derivative PCBM ([6-6]-phenyl C61 -butyric acid methyl ester) is obtained in thin films based on the blend PCBM:regioregular P3HT (poly(3-hexylthiophene)). Rapid formation of needlelike crystalline PCBM structures of a few micrometers up to 100,,m in size is demonstrated by submitting the blended thin films to an appropriate thermal treatment. These structures can grow out to a 2D network of PCBM needles and, in specific cases, to spectacular PCBM fans. Key parameters to tune the dimensions and spatial distribution of the PCBM needles are blend ratio and annealing conditions. The as-obtained blended films and crystals are probed using atomic force microscopy, transmission electron microscopy, selected area electron diffraction, optical microscopy, and confocal fluorescence microscopy. Based on the analytical results, the growth mechanism of the PCBM structures within the film is described in terms of diffusion of PCBM towards the PCBM crystals, leaving highly crystalline P3HT behind in the surrounding matrix. [source]


Concentration of IL-2, IL-6, IL-8, IL-10 and TNF-alpha in children with acute lymphoblastic leukemia after cessation of chemotherapy

HEMATOLOGICAL ONCOLOGY, Issue 1 2004
Bogdan Mazur
Abstract The immunosuppressive effect of cytotoxic drugs, basic therapeutic agents in the treatment of childhood acute leukemias, requires monitoring of the immune system following cessation of therapy. The cytokines are soluble proteins that play a key role in the immunoregulation of the lymphocyte function. The cytokines regulate growth, differentiation and function of various cells in normal conditions. The aim of our study was to estimate serum levels of IL-2, IL-6, IL-8, IL-10 and TNF-alpha in children with acute lymphoblastic leukemia (ALL) after cessation of chemotherapy. The study involved 150 children with ALL. This group consisted of: 30 children 1 month after treatment cessation; 30 children, 3 months later; 30 children 6 months later; 30 children, 9 months later and 30 children, 12 months later. The control group consisted of 30 healthy children. The levels of the cytokines under study were assayed using the immunoassay kits (R&D Systems, USA). During the study significant differences in TNF-alpha, IL-2 and IL-8 serum concentrations were observed among treated children and controls. However there were no differences in IL-6 and IL-10 concentrations. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Loss of input from the mossy cells blocks maturation of newly generated granule cells

HIPPOCAMPUS, Issue 7 2007
Ana-Isabel Marqués-Marí
Abstract The objective of this work is to check whether the input from the mossy cells to the inner molecular layer is necessary for the integration and maturation of the newly generated granule cells of the dentate gyrus (DG) in mice, and if after status epilepticus the sprouting of the mossy fibers can substitute for this projection. Newly generated cells were labeled by administration of 5-bromo-deoxyuridine either before or after pilocarpine administration. The neuronal loss in the hippocampus after administration of pilocarpine combined with scopolamine and diazepam seemed restricted to the hilar mossy cells. The maturation of the granule cells was studied using immunohistochemistry for calretinin and NeuN in combination with detection of 5-bromo-deoxyuridine. The sprouting of the mossy fibers was detected using Timm staining for zinc-rich boutons. In normal conditions, granule cells took about 2 weeks to lose the immature marker calretinin. After the loss of the mossy cells, newly generated granule cells remained expressing calretinin for more than a month, until the sprouting of the mossy fibers substituted for the projection of the mossy cells in the inner molecular layer of the DG. Therefore, a proper pattern of connectivity is necessary for the normal development and integration of newly generated granule cells in the adult brain. In a changed environment they cannot adapt transforming in other cell types; simply they are unable to mature. The sprouting of the mossy fibers, although aberrant and a probable source of epileptic activity, may be important for the correct physiology of the granule cells, restoring a likeness of normality in their connective environment. The survival of granule cells incorporated as mature neurons was increased after pilocarpine when compared with normal conditions. Thus, it is likely that the reorganization of the circuitry after the loss of the mossy cells facilitates the survival and incorporation of the newly generated granule cells. © 2007 Wiley-Liss, Inc. [source]


Phase ,: Tracking Down Material Defects

IMAGING & MICROSCOPY (ELECTRONIC), Issue 2 2009
Wanted: Steel to Handle Extreme Demands of Petroleum Extraction
The quest for extraction of petroleum and natural gas requires superior competence from both humans and materials involved. The demands made on both go far beyond normal conditions. The materials used must be produced using the best raw materials and produced at premium quality levels. Then even the tiniest fluctuations in the composition of the steel used for drills, drill rods and their casing can influence and decisively alter their required properties , such as degree of hardness, ductility and malleability. [source]


Induced and repressed genes after irradiation sensitizing by pentoxyphylline,

INTERNATIONAL JOURNAL OF CANCER, Issue 6 2007
Waldemar Waldeck
Abstract Aim in cancer therapy is to increase the therapeutic ratio eliminating the disease while minimizing toxicity to normal tissues. Radiation therapy is a main component in targeting cancer. Radiosensitizing agents like pentoxyphylline (PTX) have been evaluated to improve radiotherapy. Commonly, cells respond to radiation by the activation of specific early and late response genes as well as by inhibition of genes, which are expressed under normal conditions. A display of the genetic distinctions at the level of transcription is given here to characterize the molecular events underlying the radiosensitizing mechanisms. The method of suppression subtractive hybridization allows the visualization of both induced and repressed genes in irradiated cells compared with cells sensitized immediately after irradiation. The genes were isolated by cDNA-cloning, differential analysis and sequence similarity search. Genes involved in protein synthesis, metabolism, proteolysis and transcriptional regulation were detected. It is important that genes like KIAA280, which were only known as unidentified EST sequences before without function, but inaccessible by array technology were recovered as functional genes. Database searches for PTX-induced genes detected a human mRNA completely unknown. In case of suppressed genes, we detected several mRNAs; one thereof shows homology to a hypothetical protein possibly involved in signal transduction. A further mRNA encodes the protein BM036 supposed to associate with the E2F transcription factor. A hypothetical protein H41 was detected, which may repress the Her-2/neu receptor influencing breast cancer, gliomas and prostate tumors. Radiation combined with PTX may lead to a better prognosis by down regulation of the Her-2/neu, which will be proven by clinical studies in the near future. © 2006 Wiley-Liss, Inc. [source]


Wavelength retuning without service interruption in an all-optical survivable network

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2009
Rose Qingyang Hu
Abstract This paper proposes a new wavelength retuning (WRT) scheme in an all-optical WDM network. Compared with the existing WRT schemes developed for all-optical networks, which can alleviate the wavelength-continuity constraint but cannot avoid service interruption or data loss, the proposed scheme is able to alleviate the wavelength-continuity constraint and reduce the connection blocking probability with no service interruption to the on-going traffic. This is achieved by allocating two routes, one for active path and one for backup path, to each incoming connection request and conducting WRT only on the backup path. The backup path provides an alternate path in case of a failure, while the active path carries traffic under normal conditions. Thus, WRT on the backup path will not cause any impact on data transmission. An optimal backup path WRT scheme and a heuristic algorithm are developed and the performance evaluation on the proposed schemes is presented. The simulation results show that the proposed optimal scheme reduces the connection blocking probability by 46.8% on average, while the proposed heuristic scheme reduces the blocking probability by 28.3% on average, all compared with the scheme without WRT. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Standardized Care Planning: Evaluation of ICNP Beta in the Areas of Nutrition and Skin Care in a Practice Setting

INTERNATIONAL JOURNAL OF NURSING TERMINOLOGIES AND CLASSIFICATION, Issue 2003
Jan Florin
PURPOSE To evaluate completeness, granularity, multiple axial content, and clinical utility of the beta version of the International Classification of Nursing Practice (ICNP®). METHODS Standardized care plans were developed based on research in the areas of nutrition and skin care and clinically tested in a 35-bed infectious disease unit at a Swedish university hospital. A convenience sample of 56 computerized and manual patient records were content analyzed and mapped to the terms in ICNP® beta. FINDINGS A total of 1,771 phrases were identified. Approximately 60% of the record content describing nursing phenomena and about one third of the nursing interventions in the areas of nutrition and skin care could be expressed satisfactorily using the terminology of ICNP® beta. For about 25% of the content describing both nursing phenomena and interventions, no corresponding term was found. The most common deficiencies were focus terms for stating patient perspective or collaboration, nonhuman focus, normal findings, more qualitative judgments, and different expressions for stating duration. Some terms are available in the ICNP beta as a whole, but the organization of axes impedes or restricts the use of terms beyond the ICNP categories. Terms needed to express nursing phenomena could sometimes be found in nursing actions axes. CONCLUSIONS The ICNP® beta needs to be further developed to capture relevant data in nursing care. The axial structure needs to be evaluated, and completeness and granularity of terms need to be addressed further before ICNP beta can be used on a daily basis in the clinical setting. Terms need to be developed to express patient participation and preferences, normal conditions, qualitative dimensions and characteristics, nonhuman focuses as well as duration. Empirical studies covering the complexity of information in nursing care are needed. [source]


Applicability of the International Classification of Nursing Practice (ICNP®) in the Areas of Nutrition and Skin Care

INTERNATIONAL JOURNAL OF NURSING TERMINOLOGIES AND CLASSIFICATION, Issue 1 2003
Margareta Ehnfors PhD
PURPOSE. To evaluate completeness, granularity, multiple axial content, and clinical utility of the beta version of the ICNP® in the context of standardized nursing care planning in a clinical setting. METHODS. An 35-bed acute care ward for infectious diseases at a Swedish university hospital was selected for clinical testing. A convenience sample of 56 patient records with data on nutrition and skin care was analyzed and mapped to the ICNP. FINDINGS. Using the ICNP terminology, 59%-62% of the record content describing nursing phenomena and 30%-44% of the nursing interventions in the areas of nutrition and skin care could be expressed satisfactorily. For about a quarter of the content describing nursing phenomena and interventions, no corresponding ICNP term was found. CONCLUSIONS. The ICNP needs to be further developed to allow representation of the entire range of nursing care. Terms need to be developed to express patient participation and preferences, normal conditions, qualitative dimensions and characteristics, nonhuman focus, and duration. PRACTICE IMPLICATIONS. The practical usefulness of the ICNP needs further testing before conclusions about its clinical benefits can be determined. Search terms: ICNP®, nursing classification, standardized terminology, VIPS [source]


Indices of Drought Tolerance in Wheat Genotypes at Early Stages of Plant Growth

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 1 2004
S. S. Dhanda
Abstract Thirty diverse genotypes of bread wheat were evaluated for seed vigour index, germination percentage, root length, shoot length, root-to-shoot length ratio, coleoptile length and osmotic membrane stability under laboratory conditions. Considerable variation was observed for all the characters. Discrimination among the genotypes on the basis of mean values was better under normal than under moisture stress conditions, indicating suppression of variability under moisture stress conditions. Comparison of mean performance under normal and osmotic stress conditions indicated that the seed vigour index was the most sensitive trait, followed by shoot length, germination percentage and root length. The root-to-shoot length ratio, however, increased under osmotic stress. The magnitude of genetic components of variance and heritability were, in general, lower under osmotic stress than under normal conditions. All the characters except germination percentage, shoot length and coleoptile length showed considerable genetic variability. Heritability in the broad sense was also moderate to high for all the characters under both environments. Due to high heritability and genetic advance great benefit from selection can be expected for the osmotic membrane stability of leaf segments and root-to-shoot length ratio. Moderate progress can be expected from root length and seed vigour index. Correlation studies indicated that the osmotic membrane stability of the leaf segment was the most important trait, followed by root-to-shoot ratio and root length on the basis of their relationships with other traits. [source]


Intervertebral disc, sensory nerves and neurotrophins: who is who in discogenic pain?

JOURNAL OF ANATOMY, Issue 1 2010
José García-Cosamalón
Abstract The normal intervertebral disc (IVD) is a poorly innervated organ supplied only by sensory (mainly nociceptive) and postganglionic sympathetic (vasomotor efferents) nerve fibers. Interestingly, upon degeneration, the IVD becomes densely innervated even in regions that in normal conditions lack innervation. This increased innervation has been associated with pain of IVD origin. The mechanisms responsible for nerve growth and hyperinnervation of pathological IVDs have not been fully elucidated. Among the molecules that are presumably involved in this process are some members of the family of neurotrophins (NTs), which are known to have both neurotrophic and neurotropic properties and regulate the density and distribution of nerve fibers in peripheral tissues. NTs and their receptors are expressed in healthy IVDs but much higher levels have been observed in pathological IVDs, thus suggesting a correlation between levels of expression of NTs and density of innervation in IVDs. In addition, NTs also play a role in inflammatory responses and pain transmission by increasing the expression of pain-related peptides and modulating synapses of nociceptive neurons at the spinal cord. This article reviews current knowledge about the innervation of IVDs, NTs and NT receptors, expression of NTs and their receptors in IVDs as well as in the sensory neurons innervating the IVDs, the proinflammatory role of NTs, NTs as nociception regulators, and the potential network of discogenic pain involving NTs. [source]


Low-temperature-driven early spawning migration of a temperate marine fish

JOURNAL OF ANIMAL ECOLOGY, Issue 2 2004
David W. Sims
Summary 1It is often assumed that the timing of annual migrations of marine fish to spawning grounds occurs with very little change over time. However, it is unclear how much migration is influenced by climate change in marine species that spawn at sea but spend most time in estuarine conditions, especially as thermal regimes in estuaries may differ significantly from those in the open sea. 2Migration phenology was studied in a population of flounder, Platichthys flesus (L.) off south-west England using high-temporal resolution trawling data over a 13-year period. 3Flounder migrated from their estuarine habitat to spawning grounds at sea some 1,2 months earlier in years that were up to 2 °C cooler. Flounder arrived on the spawning grounds over a shorter time period (2,6 days) when colder than normal conditions prevailed in the estuary, compared to warmer years (12,15 days). This suggests that they were responding to low temperatures by exhibiting a more synchronous, population-level early migration. 4The timing of migration was earlier when the largest differences in temperatures between near-estuary and offshore environments occurred, differences that were related significantly to cold, negative phases of the North Atlantic Oscillation (NAO). 5Flounder migration phenology appears to be driven to a large extent by short-term, climate-induced changes in the thermal resources of their overwintering habitat. This suggests that climate fluctuations characterizing the NAO may have significant effects on the timing of the peak abundance of fish populations generally, which, in turn, may have implications for fisheries management. [source]


Treatment with oxidizing agents damages the inner membrane of spores of Bacillus subtilis and sensitizes spores to subsequent stress

JOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2004
D.E. Cortezzo
Abstract Aims:, To determine if treatment of Bacillus subtilis spores with a variety of oxidizing agents causes damage to the spore's inner membrane. Methods and Results:, Spores of B. subtilis were killed 80,99% with wet heat or a variety of oxidizing agents, including betadine, chlorine dioxide, cumene hydroperoxide, hydrogen peroxide, OxoneTM, ozone, sodium hypochlorite and t-butylhydroperoxide, and the agents neutralized and/or removed. Survivors of spores pretreated with oxidizing agents exhibited increased sensitivity to killing by a normally minimal lethal heat treatment, while spores pretreated with wet heat did not. In addition, spores treated with wet heat or the oxidizing agents, except sodium hypochlorite, were more sensitive to high NaCl in plating media than were untreated spores. The core region of spores treated with at least two oxidizing agents was also penetrated much more readily by methylamine than was the core of untreated spores, and spores treated with oxidizing agents but not wet heat germinated faster with dodecylamine than did untreated spores. Spores of strains with very different levels of unsaturated fatty acids in their inner membrane exhibited essentially identical resistance to oxidizing agents. Conclusions:, Treatment of spores with oxidizing agents has been suggested to cause damage to the spore's inner membrane, a membrane whose integrity is essential for spore viability. The sensitization of spores to killing by heat and to high salt after pretreatment with oxidizing agents is consistent with and supports this suggestion. Presumably mild pretreatment with oxidizing agents causes some damage to the spore's inner membrane. While this damage may not be lethal under normal conditions, the damaged inner membrane may be less able to maintain its integrity, when dormant spores are exposed to high temperature or when germinated spores are faced with osmotic stress. Triggering of spore germination by dodecylamine likely involves action by this agent on the spore's inner membrane allowing release of the spore core's depot of dipicolinic acid. Presumably dodecylamine more readily alters the permeability of a damaged inner membrane and thus more readily triggers germination of spores pretreated with oxidizing agents. Damage to the inner spore membrane by oxidizing agents is also consistent with the more rapid penetration of methylamine into the core of treated spores, as the inner membrane is likely the crucial permeability barrier to methylamine entry into the spore core. As spores of strains with very different levels of unsaturated fatty acids in their inner membrane exhibited essentially identical resistance to oxidizing agents, it is not through oxidation of unsaturated fatty acids that oxidizing agents kill and/or damage spores. Perhaps these agents work by causing oxidative damage to key proteins in the spore's inner membrane. Significance and Impact of the Study:, The more rapid heat killing and germination with dodecylamine, the greater permeability of the spore core and the osmotic stress sensitivity in outgrowth of spores pretreated with oxidizing agents is consistent with such agents causing damage to the spore's inner membrane, even if this damage is not lethal under normal conditions. It may be possible to take advantage of this phenomenon to devise improved, less costly regimens for spore inactivation. [source]


Induction of complement sensitivity in Escherichia coli by citric acid and low pH

JOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2001
C. Ocaña-Morgner
Aims:,The lytic functions of the complement system play an important role in the control of Gram-negative infections. Complement-resistant Escherichia coli LP1395 (O18) grown under normal conditions can survive the bactericidal action of complement present in human serum. Towards elucidating the mechanisms of complement resistance, the resistance of E. coli LP1395 grown under conditions of low pH and in the presence of citric acid was tested. Methods and Results:,E. coli LP1395 becomes sensitive to complement after growth in the presence of citric acid at pH 5. Complement resistance could be restored when the cells were transferred to pH 7 media. However, this recovery was greatly impaired when the cells were transferred to pH 7 media with chloramphenicol. This implies that protein synthesis may be involved in complement resistance. The cells exposed to citric acid at pH 5 showed no indication of a generalized outer membrane (OM) permeability when compared with those grown under normal conditions in terms of sensitivity to lysozyme, uptake of lipophilic dye, or sensitivity to a number of antibiotics. Conclusions:,Complement-resistant LP1395 may acquire a sensitivity to complement due not to a generalized disruption of the OM barrier, but possibly to the alteration of the activity of one or more normal complement resistance factors. Significance and Impact of the Study:,The elucidation of the echanisms of complement resistance of Gram-negative pathogens would bring important information about bacterial infections. Complement resistance factors could also be potential targets in antimicrobial therapies. [source]


Amino-terminus domain of the androgen receptor as a molecular target to prevent the hormonal progression of prostate cancer

JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2006
Gang Wang
Abstract Prostate cancer has a propensity to metastasize to the bone. Currently the only effective systemic treatment for these patients is androgen ablation therapy. However, the tumor will invariably progress to an androgen-independent stage and the patient will succumb to his disease within approximately 2 years. The earliest indication of hormonal progression is the rising titer of serum prostate specific antigen. Current evidence implicates the androgen receptor (AR) as a key factor in maintaining the growth of prostate cancer cells in an androgen-depleted state. Under normal conditions, binding of ligand activates the receptor, allowing it to effectively bind to its respective DNA element. However, AR is also transformed in the absence of androgen (ligand-independent activation) in prostate cells via multiple protein kinase pathways and the interleukin-6 (IL-6) pathway that converge upon the N-terminal domain of the AR. This domain is the main region for phosphorylation and is also critical for normal coregulator recruitment. Here we discuss evidence supporting the role of the AR, IL-6 and other protein kinase pathways in the hormonal progression of prostate cancer to androgen independence and the mechanisms involved in activation of the AR by these pathways. Receptor-targeted therapy, especially potential drugs targeting the N-terminal domain, may effectively prevent or delay the hormonal progression of AR-dependent prostate cancer. J. Cell. Biochem. 98: 36,53, 2006. © 2006 Wiley-Liss, Inc. [source]