Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Intrinsic

  • neuron intrinsic

  • Terms modified by Intrinsic

  • intrinsic ability
  • intrinsic activity
  • intrinsic ageing
  • intrinsic apoptosi pathway
  • intrinsic apoptotic pathway
  • intrinsic capacity
  • intrinsic change
  • intrinsic characteristic
  • intrinsic clearance
  • intrinsic component
  • intrinsic defect
  • intrinsic difference
  • intrinsic difficulty
  • intrinsic disorder
  • intrinsic excitability
  • intrinsic factor
  • intrinsic feature
  • intrinsic fluorescence
  • intrinsic form
  • intrinsic growth rate
  • intrinsic gtpase activity
  • intrinsic interest
  • intrinsic kinetics
  • intrinsic mechanism
  • intrinsic membrane property
  • intrinsic motivation
  • intrinsic parameter
  • intrinsic pathway
  • intrinsic plasticity
  • intrinsic process
  • intrinsic property
  • intrinsic quality
  • intrinsic rate
  • intrinsic reaction coordinate
  • intrinsic reactivity
  • intrinsic resistance
  • intrinsic sensitivity
  • intrinsic sensory neuron
  • intrinsic signal
  • intrinsic sphincter deficiency
  • intrinsic stability
  • intrinsic type
  • intrinsic value
  • intrinsic variability
  • intrinsic viscosity
  • intrinsic viscosity measurement
  • intrinsic water-use efficiency

  • Selected Abstracts

    Theoretical Studies on Metal,Metal Interaction and Intrinsic 1,3[,*(d),(s/p)] Excited States of Dinuclear d10 Complexes with Bridging Phosphane Ligands

    Qing-Jiang Pan
    Abstract To explore the metal,metal interaction and spectroscopic properties, the ground- and excited-state structures of [M2(dpm)2]2+ [M = Ag (2), Cu (3), dpm = bis(diphosphanyl)methane] and their solvated species [M2(dpm)2]2+·(MeCN)2 were optimized by the MP2 and CIS methods, respectively. In the ground states, the calculated M,M distances and their corresponding M,M stretching frequencies for 2 and 3 indicate the presence of metallophilic attraction; there is strong N,Cu/Ag coordination in acetonitrile, which is different from the case in previous studies of [Au2(dpm)2]2+ (1). CIS calculations show that 2 and 3 have 1,3[,*(d),(s/p)] as their lowest-energy excited state, as is also the case for 1, confirmed by unrestricted MP2 calculations. On the basis of the CIS-optimized structures, the TD-DFT (B3LYP) method was employed to calculate the emission spectra of such complexes. For 3, the phosphorescent emissions were calculated at 424 and 514 nm in the solid state and acetonitrile, which is comparable to the experimental data of 475 and 480 nm, respectively. The comparison between the gas-phase and solution emissions for 1,3 reveals that the N,M coordination results in a large red-shift of the emission wavelength. Taking previous studies into account , we found that the M,M distances are linearly correlated with the M,M stretching frequencies for the dinuclear d10 complexes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

    Intrinsic and spontaneous neurogenesis in the postnatal slice culture of rat hippocampus

    Maki Kamada
    Abstract Organotypic slice culture preserves the morphological and physiological features of the hippocampus of live animals for a certain time. The hippocampus is one of exceptional regions where neurons are generated intrinsically and spontaneously throughout postnatal life. We investigated the possibility that neurons are generated continuously at the dentate granule cell layer (GCL) in slice culture of the rat hippocampus. Using 5-bromodeoxyuridine (BrdU) labelling and retrovirus vector transduction methods, the phenotypes of the newly generated cells were identified immunohistochemically. At 4 weeks after BrdU exposure, BrdU-labelled cells were found in the GCL and were immunoreactive with a neuronal marker, anti-NeuN. There were fibrils immunoreactive with anti-glial fibrillary acidic protein (GFAP), an astrocyte marker, in the layer covering the GCL and occasionally encapsulated BrdU-labelled nuclei. When the newly divided cells were marked with the enhanced green fluorescent protein (EGFP) using a retrovirus vector, these cells had proliferative abilities throughout the following 4-week cultivation period. Four weeks after the inoculation, the EGFP-expressing cells consisted of various phenotypes of both early and late stages of differentiation; some were NeuN-positive cells with appearances of neurons in the GCL and some were immunoreactive with anti-Tuj1, a marker of immature neurons. Some EGFP-expressing cells were immunoreactive with anti-GFAP or anti-nestin, a marker of neural progenitors. The present study suggests that slice cultures intrinsically retain spontaneous neurogenic abilities for their cultivation period. The combination of slice culture and retrovirus transduction methods enable the newly divided cells to be followed up for a long period. [source]

    Intrinsic and extrinsic factors in skin ageing: a review

    M. A. Farage
    Synopsis As the proportion of the ageing population in industrialized countries continues to increase, the dermatological concerns of the aged grow in medical importance. Intrinsic structural changes occur as a natural consequence of ageing and are genetically determined. The rate of ageing is significantly different among different populations, as well as among different anatomical sites even within a single individual. The intrinsic rate of skin ageing in any individual can also be dramatically influenced by personal and environmental factors, particularly the amount of exposure to ultraviolet light. Photodamage, which considerably accelerates the visible ageing of skin, also greatly increases the risk of cutaneous neoplasms. As the population ages, dermatological focus must shift from ameliorating the cosmetic consequences of skin ageing to decreasing the genuine morbidity associated with problems of the ageing skin. A better understanding of both the intrinsic and extrinsic influences on the ageing of the skin, as well as distinguishing the retractable aspects of cutaneous ageing (primarily hormonal and lifestyle influences) from the irretractable (primarily intrinsic ageing), is crucial to this endeavour. Résumé Comme le pourcentage de la population vieillissante dans les pays industrialisés s'accroît, les préoccupations dermatologiques des personnes âgées augmentent en importance sur le plan médical. Les modifications structurelles intrinsèques sont une conséquence naturelle du vieillissement et sont génétiquement déterminées. La vitesse de vieillissement diffère significativement selon les différentes populations et selon les différents sites anatomiques, même pour un seul individu. La vitesse intrinsèque du vieillissement de la peau pour un individu peut être aussi très influencée par les facteurs personnels et environnementaux, en particulier le taux d'exposition à la lumière ultra-violette. La photodégradation qui accélère considérablement le vieillissement visible de la peau augmente également beaucoup le risque de formation de néoplasme cutané. Au fur et à mesure que la population vieillit, il faut davantage se préoccuper de diminuer la morbidité réelle associée au vieillissement de la peau, plutôt que de palier à ses conséquences cosmétiques. Il est donc crucial de s'efforcer à mieux comprendre les facteurs intrinsèques et extrinsèques qui agissent sur le vieillissement de la peau et aussi de faire la distinction entre les aspects réversibles du vieillissement cutané (facteurs essentiellement hormonaux et mode de vie) et les aspects irréversibles (principalement le vieillissement intrinsèque). [source]

    Second-degree atrioventricular block (Mobitz Type I) in an adolescent with anorexia nervosa: Intrinsic or acquired conduction abnormality

    Nuray Ö. Kanbur MD
    Abstract Anorexia nervosa (AN) can cause both functional and structural cardiac complications, including a variety of different conduction abnormalities. This is the first case report of symptomatic diurnal second-degree atrioventricular (AV) block (Mobitz Type I) in an adolescent with AN. We present a 12-year-old girl with AN, restrictor sub-type who reported cardiac symptoms during weight gain, at the time of the initial diagnosis of AV block. Second-degree AV block (Mobitz Type I) is discussed as a possible complication of the AN, as well as being an intrinsic conduction system disease. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2009 [source]

    Intrinsic and acquired resistance to quaternary ammonium compounds in food-related Pseudomonas spp.

    S. Langsrud
    Abstract Aims: To determine the sensitivity of a strain used for disinfectants testing (Pseudomonas aeruginosa ATCC 15442) and food-associated isolates to benzalkonium chloride and didecyl dimethylammonium chloride (DDAC). To determine whether the increase in bacterial resistance after adaptation to DDAC can be associated with phenotypic changes. To test the activity of alternative disinfectants to eliminate resistant Pseudomonas spp. Methods and Results:Pseudomonas aeruginosa ATCC 15442 was among the most resistant strains tested using a bactericidal suspension test. Growth of a sensitive Ps. fluorescens in gradually higher concentrations of DDAC resulted in stable higher resistance and to some cross-resistance to several antibacterial agents, with the exception of disinfectants containing chloramine T, glutaraldehyde or peracetic acid. It was shown by microscopy that adaptation was followed by loss of flagella, and slime formation. Removal of the slime by sodium dodecyl sulphate resulted in partial loss of the acquired resistance. Conclusions:Pseudomonas spp. may adapt to survive against higher concentrations of quaternary ammonium compounds (QACs), but resistant strains can be eliminated with chemically unrelated disinfectants. Significance and Impact of the Study: The work supports the rotation of disinfectants in food processing environments for avoiding the development of bacterial resistance to QACs. The alternating disinfectants should be chosen carefully, because of possible cross-resistance. [source]

    Comparing Democrats and Republicans on Intrinsic and Extrinsic Values

    Kennon M. Sheldon
    Although claimed differences in values have played a prominent role in recent U.S. politics, the value systems of typical Republicans and Democrats have not been evaluated within a relevant dimensional framework. In 4 studies, party members were compared on extrinsic (money, popularity, image) and intrinsic (intimacy, helping, growth) values. Republicans were consistently higher on extrinsic relative to intrinsic values, a pattern suggested by past research to be personally and socially problematic. In Study 4, Republicans were also lower in a different measure of prosocial values, derived from social-dilemma research. All studies found an interaction such that only nonreligious Republicans were lower than Democrats on the intrinsic value of helping needy others. Implications for contemporary political discourse are discussed. [source]

    Intrinsic and extrinsic determinants of mountain pine beetle population growth

    M. Kurtis Trzcinski
    Abstract 1,Mountain pine beetle Dendroctonus ponderosae populations have large, economically significant outbreaks. Density dependence and environmental variability are expected to have important effects on their dynamics. We analysed time series data from an outbreak in the 1930s to determine the relative importance of population density and environmental variability on local population growth rates. 2,Resource depletion occurred rapidly at the scale of 0.4 ha and population growth rates were strongly density dependent. Annual environmental changes did not have detectable effects on population growth rates, leading to the conclusion that intrinsic processes influenced local population density more than extrinsic factors during this outbreak. 3,Our calculated value of rmax (1.16) does not suggest intrinsically cyclic population dynamics. Our estimate of rmax and density dependence will be useful in developing applied models of mountain pine beetle outbreaks, and the subsequent evaluation of management strategies. [source]

    Intrinsic and extrinsic erythropoietin enhances neuroprotection against ischemia and reperfusion injury in vitro

    Ruiqin Liu
    Abstract This study was designed to investigate the neuroprotective effect of intrinsic and extrinsic erythropoietin (EPO) against hypoxia/ischemia, and determine the optimal time-window with respect to the EPO-induced neuroprotection. Experiments were conducted using primary mixed neuronal/astrocytic cultures and neuron-rich cultures. Hypoxia (2%) induces hypoxia-inducible factor-1, (HIF-1,) activity followed by strong EPO expression in mixed cultures and weak expression in neuron-rich cultures as documented by both western blot and RT,PCR. Immunoreactive EPO was strongly detected in astrocytes, whereas EPOR was only detected in neurons. Neurons were significantly damaged in neuron-rich cultures but were distinctly rescued in mixed cultures. Application of recombinant human EPO (rhEPO) (0.1 U/mL) within 6 h before or after hypoxia significantly increased neuronal survival compared with no rhEPO treatment. Application of rhEPO after onset of reoxygenation achieved the maximal neuronal protection against ischemia/reperfusion injury (6 h hypoxia followed 24 h reoxygenation). Our results indicate that HIF-1, induces EPO gene released by astrocytes and acts as an essential mediator of neuroprotection, prove the protective role of intrinsic astrocytic-neuronal signaling pathway in hypoxic/ischemic injury and demonstrate an optimal therapeutic time-window of extrinsic rhEPO in ischemia/reperfusion injury in vitro. The results point to the potential beneficial effects of HIF-1, and EPO for the possible treatment of stroke. [source]

    Religion as Culture: Religious Individualism and Collectivism Among American Catholics, Jews, and Protestants

    Adam B. Cohen
    ABSTRACT We propose the theory that religious cultures vary in individualistic and collectivistic aspects of religiousness and spirituality. Study 1 showed that religion for Jews is about community and biological descent but about personal beliefs for Protestants. Intrinsic and extrinsic religiosity were intercorrelated and endorsed differently by Jews, Catholics, and Protestants in a pattern that supports the theory that intrinsic religiosity relates to personal religion, whereas extrinsic religiosity stresses community and ritual (Studies 2 and 3). Important life experiences were likely to be social for Jews but focused on God for Protestants, with Catholics in between (Study 4). We conclude with three perspectives in understanding the complex relationships between religion and culture. [source]


    ALCOHOLISM, Issue 2008
    Amina E Jamali
    Alcohol exposure to the developing brain compromises both neurons and glial functions. While neurons are considered the primary targets, microglia may play a neurotoxic role in this process. Previous studies demonstrated that neuron death is due to oxidative stress and mitochondrially mediated (Intrinsic). These studies showed a rapid increase (within minutes) in reactive oxygen species (ROS). Due to the diffusive nature of ethanol and multiple sources of free radicals, we sought to determine the primary source of superoxide targeted by ethanol. Confocal studies of neurons suggest that the superoxide radicals may originate from the mitochondria. Using whole neurons in a luminol-based chemiluminescence assay (Diogenes) we detected superoxide radicals in the extracellular mileu. We observed a two-three fold transient increase in the steady state generation of superoxide radicals between 20 minutes to one hour of ethanol exposure (4mg/ml). However, the presence of Rotenone (mitochondrial complex I inhibitor) and DPI (an inhibitor of all flavinoids) blocked the release of these superoxide radicals. Interestingly, cortical microglia treated identically with ethanol, showed a greater than five fold increase in superoxide generation with a maximum at one hour. Moreover, since ethanol is known to induce hydrogen peroxide generation, it was used as a mimetic. Hydrogen peroxide also induced the production of superoxide different time kinetics. Thus, together these data demonstrate that ethanol induces the steady state production of superoxide radicals in the extracellular mileu in a mitochondrial dependent manner. Since NOX2 an NADPH oxidase is expressed in neurons, it is a potential candidate for the secondary sites of superoxide generation. The ROS network between mitochondria and the plasma membrane highlights new therapeutical targets to counter ethanol toxicity. [source]

    Relative Importance of Intrinsic, Extrinsic, and Anthropic Factors in the Geomorphic Zonation of the Trinity River, Texas,

    Jonathan D. Phillips
    Phillips, Jonathan D., 2010. Relative Importance of Intrinsic, Extrinsic, and Anthropic Factors in the Geomorphic Zonation of the Trinity River, Texas. Journal of the American Water Resources Association (JAWRA) 46(4): 807-823. DOI: 10.1111/j.1752-1688.2010.00457.x Abstract:, The Trinity River, Texas, was characterized according to its geologic framework, valley width and confinement, slope, sinuosity, channel-floodplain connectivity, and flow regime, leading to the identification of 18 hinge points along the 638 km study area where major transitions in two or more criteria occur. These, and effects of human agency, avulsions, and sea level rise, delineate 21 river styles or zones. Each zone was evaluated with respect to dominant factors determining its geomorphological characteristics: geology/lithology, tectonics, Holocene sea level rise, meandering, cutoffs and other lateral channel changes, avulsions, valley constrictions by alluvial terraces, and paleomeander depressions. Direct human influences (a large impoundment and water withdrawals) are also evident. Entropy of the relationships between these controls and the geomorphological zones shows that all the controls are significant, and each accounts for 4-15% of the total entropy. Geologic controls, lateral channel changes, and constriction by terraces are the three most influential controls, illustrating that controls on river morphology include extrinsic boundary conditions, active process-form interrelationships, and inherited features. Extrinsic and intrinsic controls each account for about a third of the entropy, but the latter includes antecedent features as well as active channel dynamics, underscoring the importance of historical contingency even in alluvial rivers. [source]

    Novel Aspects of Intrinsic and Extrinsic Aging of Human Skin: Beneficial Effects of Soy Extract,

    Kirstin M. Südel
    ABSTRACT Biochemical and structural changes of dermal connective tissue substantially contribute to the phenotype of aging skin. To study connective tissue metabolism with respect to ultraviolet (UV) exposure, we performed an in vitro (human dermal fibroblasts) and an in vivo complementary DNA array study in combination with protein analysis in young and old volunteers. Several genes of the collagen metabolism such as Collagen I, III and VI as well as heat shock protein 47 and matrix metalloproteinase-1 are expressed differentially, indicating UV-mediated effects on collagen expression, processing and degradation. In particular, Collagen I is time and age dependently reduced after a single UV exposure in human skin in vivo. Moreover, older subjects display a lower baseline level and a shorter UV-mediated increase in hyaluronan (HA) levels. To counteract these age-dependent changes, cultured fibroblasts were treated with a specific soy extract. This treatment resulted in increased collagen and HA synthesis. In a placebo-controlled in vivo study, topical application of an isoflavone-containing emulsion significantly enhanced the number of dermal papillae per area after 2 weeks. Because the flattening of the dermal-epidermal junction is the most reproducible structural change in aged skin, this soy extract appears to rejuvenate the structure of mature skin. [source]

    Intrinsic brain connectivity in fibromyalgia is associated with chronic pain intensity,

    ARTHRITIS & RHEUMATISM, Issue 8 2010
    Vitaly Napadow
    Objective Fibromyalgia (FM) is considered to be the prototypical central chronic pain syndrome and is associated with widespread pain that fluctuates spontaneously. Multiple studies have demonstrated altered brain activity in these patients. The objective of this study was to investigate the degree of connectivity between multiple brain networks in patients with FM, as well as how activity in these networks correlates with the level of spontaneous pain. Methods Resting-state functional magnetic resonance imaging (FMRI) data from 18 patients with FM and 18 age-matched healthy control subjects were analyzed using dual-regression independent components analysis, which is a data-driven approach for the identification of independent brain networks. Intrinsic, or resting-state, connectivity was evaluated in multiple brain networks: the default mode network (DMN), the executive attention network (EAN), and the medial visual network (MVN), with the MVN serving as a negative control. Spontaneous pain levels were also analyzed for covariance with intrinsic connectivity. Results Patients with FM had greater connectivity within the DMN and right EAN (corrected P [Pcorr] < 0.05 versus controls), and greater connectivity between the DMN and the insular cortex, which is a brain region known to process evoked pain. Furthermore, greater intensity of spontaneous pain at the time of the FMRI scan correlated with greater intrinsic connectivity between the insula and both the DMN and right EAN (Pcorr < 0.05). Conclusion These findings indicate that resting brain activity within multiple networks is associated with spontaneous clinical pain in patients with FM. These findings may also have broader implications for how subjective experiences such as pain arise from a complex interplay among multiple brain networks. [source]

    3135: Modulation of apoptotic signaling pathways to promote survival of endothelial cells by gene therapy

    Purpose Corneal transplantation is the most common transplantation worldwide. Surgeons and eye banks face major problems: (1) shortage of tissue in aging populations, (2) loss of high-quality tissue due to cell loss during storage, (3) graft failure. It has been demonstrated that EC loss is mediated by the cells' intrinsic death machinery resulting in apoptosis. Identification of survival strategies could raise the availability of tissue, with a significant impact on transplantation by lowering graft rejection rate. The purpose of this study different apoptotic pathways and to determine the protective effect of the anti-apoptotic proteins bcl-xL and p35. Methods Intrinsic (mitochondria-mediated) and extrinsic (ligand-mediated) apoptotic pathways were selectively activated to provoke apoptosis of murine and human corneal endothelial cells suspensions and corneas. Gene transfer of bcl-xL or p35 was accomplished, survival of EC was determined by flow cytometry and laser scanning microscopy. Results Interestingly, we were able to determine distinct differences in cell survival enhancement depending on the type of overexpressed protein. Whereas uninfected controls showed significant EC death, gene-therapeutically treated EC demonstrated significantly increased cell survival. We will present data on the efficacy of certain anti-apoptotic proteins in select pathways. Conclusion Exploring inhibitory strategies of EC death can lead to clinically relevant survival strategies with significant impact on corneal grafting. [source]

    Sensitive skin: closing in on a physiological cause

    CONTACT DERMATITIS, Issue 3 2010
    Miranda A. Farage
    The phenomenon of ,sensitive skin' is a relatively recent complaint in which certain individuals report more intense and frequent adverse sensory effects than the normal population upon use of cosmetic (personal-care) products. Originally defined as a minority complaint, sensitive skin is now claimed by a majority of women in industrialized countries and nearly half of men. Sensitive skin is self-diagnosed and typically unaccompanied by any obvious physical signs of irritation, and the number of individuals who claim sensitivity has risen steadily with the number of consumer products targeted towards this supposedly uncommon group. Believed by many dermatologists, therefore, to be a ,princess and the pea' phenomenon, the problem of sensitive skin has largely avoided focussed research. Over the last few years, however, the evidence of documentable biophysical changes associated with the largely sensory symptoms of this disorder has accumulated, including some gained by improved methods of identifying subclinical signs of skin irritation. Although the understanding of the aetiology of this phenomenon is as yet incomplete, existing research now supports a biophysical origin for this disorder. Effective methods of diagnosis, intrinsic and extrinsic contributors to exaggerated neural sensitivity, and the specific mechanisms of the discomfort associated with the compliant are required, as are appropriate means of prevention and treatment. [source]

    Quality of life of male outpatients with personality disorders or psychotic disorders: a comparison

    Yvonne HA Bouman
    Background,Quality of life (QoL) has become increasingly important as an outcome measure in community-based psychiatry. QoL refers to an individual's sense of well-being and satisfaction with his current life conditions. It is measured both through objective social indicators and life domain-specific subjective indicators. People with a personality disorder (PD) or a major mental disorder (MMD) tend to show poor social adjustment, but their relative subjective QoL is not known. Aim,To compare the QoL of male outpatients in treatment for PD or MMD overall and by means of specific social and subjective indicators. Methods,A sample of 135 men under treatment for PD in Dutch forensic outpatient facilities were compared with 79 men with MMD using the extended Dutch version of the Lancashire Quality of Life Profile (LQoLP). Results,Almost all of the objective indicators of QoL were significantly poorer among men with MMD than those with PD, but the groups did not differ on domain-specific subjective ratings of QoL. Indeed, global subjective QoL was lower in the PD than in the MMD patient group. PD outpatients seemed to have a more complex concept of QoL than the MMD outpatients for whom almost half of the variance in subjective QoL rating was related to their everyday activities and their objective sense of safety. Conclusions and implications for practice,Further study of QoL among PD patients would be warranted to test the extent to which subjective dissatisfaction is intrinsic to PD and to explore the possibility of improving it with targeted treatments. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Symmetry-breaking in mammalian cell cohort migration during tissue pattern formation: Role of random-walk persistence

    CYTOSKELETON, Issue 4 2005
    S. Huang
    Abstract Coordinated, cohort cell migration plays an important role in the morphogenesis of tissue patterns in metazoa. However, individual cells intrinsically move in a random walk-like fashion when studied in vitro. Hence, in the absence of an external orchestrating influence or template, the emergence of cohort cell migration must involve a symmetry-breaking event. To study this process, we used a novel experimental system in which multiple capillary endothelial cells exhibit spontaneous and robust cohort migration in the absence of chemical gradients when cultured on micrometer-scale extracellular matrix islands fabricated using microcontact printing. A computational model suggested that directional persistence of random-walk and dynamic mechanical coupling of adjacent cells are the critical control parameters for this symmetry-breaking behavior that is induced in spatially-constrained cell ensembles. The model predicted our finding that fibroblasts, which exhibit a much shorter motility persistence time than endothelial cells, failed to undergo symmetry breaking or produce cohort migration on the matrix islands. These findings suggest that cells have intrinsic motility characteristics that are tuned to match their role in tissue patterning. Our results underscore the importance of studying cell motility in the context of cell populations, and the need to address emergent features in multicellular organisms that arise not only from cell-cell and cell-matrix interactions, but also from properties that are intrinsic to individual cells. Cell Motil. Cytoskeleton 61:201,213, 2005. © 2005 Wiley-Liss, Inc. [source]

    Oral Isotretinoin as Part of the Treatment of Cutaneous Aging

    Enrique Hernandez-Perez MD
    Background. A number of drugs have been used to prevent aging changes. However, studies of oral isotretinoin, the commonly used acne drug, as an antiaging drug are lacking. Objective. To determine improvement in cutaneous aging utilizing oral isotretinoin combined with different procedures of facial rejuvenation. Methods. Sixty patients ranging in age from 35 to 65 years, in whom additional modalities of rejuvenation were also used, were randomly assigned to receive treatment with oral isotretinoin (10,20 mg three times a week for 2 months, group A). Their results were compared with 60 patients who had undergone the same surgical procedures but with no oral isotretinoin (group B). Results. All patients treated with oral isotretinoin noted improvement in wrinkles, thickness and color of the skin, size of pores, skin elasticity, tone, and reduction in pigmented lesions and mottled hyperpigmentation. A statistically significant difference was found in the improvement of group A (Wilcoxon test <0.01). Using minimal amounts of this drug, the side effects were practically negligible. Conclusion. Utilizing various procedures with oral isotretinoin allowed us to improve the effects of cutaneous aging. Our results using isotretinoin in these cases have been satisfactory. We believe that this is one of the first reports of the use of oral isotretinoin in intrinsic and photoaged skin. [source]

    Contribution of mesothelium-derived cells to liver sinusoids in avian embryos

    J.M. Pérez-Pomares
    Abstract The developing liver is vascularized through a complex process of vasculogenesis that leads to the differentiation of the sinusoids. The main structural elements of the sinusoidal wall are endothelial and stellate (Ito) cells. We have studied the differentiation of the hepatic sinusoids in avian embryos through confocal colocalization of differentiation markers, in ovo direct labeling of the liver mesothelium, induced invasion of the developing chick liver by quail proepicardial cells, and in vitro culture of chimeric aggregates. Our results show that liver mesothelial cells give rise to mesenchymal cells which intermingle between the growing hepatoblast cords and become incorporated to the sinusoidal wall, contributing to both endothelial and stellate cell populations. We have also shown that the proepicardium, a mesothelial tissue anatomically continuous with liver mesothelium, is able to form sinusoid-like vessels into the hepatic primordium as well as in cultured aggregates of hepatoblasts. Thus, both intrinsic or extrinsic mesothelium-derived cells have the developmental potential to contribute to the establishment of liver sinusoids. Developmental Dynamics 229:465,474, 2004. © 2004 Wiley-Liss, Inc. [source]

    Structural and functional changes in the olfactory pathway of adult Drosophila take place at a critical age

    Jean-Marc Devaud
    Abstract The olfactory system of several holometabolous insect species undergoes anatomical changes after eclosion of the imago, following those occurring during metamorphosis. In parallel, odor experience and learning performance also evolve with age. Here, we analyze the case of adult Drosophila females. Synaptogenesis in the antennal lobe (AL) starts in late pupa and continues during the first days of adult life, at the same time as the behavioral response to odors matures. Individual olfactory glomeruli (DM6, DM2, and V) display specific growth patterns between days 1 and 12 of adult life. Experience can modify the olfactory pathway both structurally and functionally as shown by adaptation experiments. The modifications associated with this form of nonassociative learning seem to take place at a critical age. Exposure to benzaldehyde at days 2,5 of adult life, but not at 8,11, causes behavioral adaptation as well as structural changes in DM2 and V glomeruli. Altered levels in intracellular cAMP, caused by dunce and rutabaga mutants, do not affect the normal changes in glomerular size, at least at day 6 of development, but they prevent those elicited by experience, establishing a molecular difference between glomerular changes of intrinsic versus environmental origin. Taken together, these data demonstrate an imprinting-like phenomenon in the olfactory pathway of young Drosophila adults, and illustrate its glomerulus-specific dynamics. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 13,23, 2003 [source]

    Decreased red blood cell aggregation subsequent to improved glycaemic control in Type 2 diabetes mellitus

    DIABETIC MEDICINE, Issue 4 2003
    B. Chong-Martinez
    Abstract Aims Reports of rheological changes following intensification of metabolic control are limited and not concordant. The present study was designed to test the hypothesis that intensification of management of Type 2 diabetes (T2DM) with diet, exercise and insulin improves haemorheological behaviour by reducing red blood cell (RBC) aggregation. Methods Blood was sampled from 55 subjects before and following 14 ± 3 weeks of intensified management. RBC aggregation was measured in vitro for cells in plasma or in an aggregating 70 kD dextran solution. Plasma viscosity and whole blood viscosity were also measured. Results During treatment, fasting glucose fell 27%, HbA1c fell 21%, and serum triglycerides and total cholesterol fell 28% and 12%, respectively (P < 0.0001 for each). The extent and strength of RBC aggregation in plasma fell by 10,13% (P < 0.002). Similar decreases of RBC aggregation were seen for cells suspended in dextran (P < 0.002). Plasma viscosity decreased by 3% (P < 0.02) and high shear blood viscosity by 6,7% (P < 0.0001). Changes of RBC aggregation in plasma and in dextran were significantly correlated, supporting a cellular rather than a plasmatic origin for these changes. However, there were no significant correlations between RBC aggregation changes and changes of fasting glucose, HbA1c, serum triglycerides, serum cholesterol, or plasma fibrinogen. Conclusions Intensified metabolic control results in a reduction of RBC aggregation that appears to be intrinsic to RBC. Since increased RBC aggregation can impair microcirculatory flow, it is possible that haemorheological factors may contribute to the reduction of microvascular complications resulting from improved metabolic control in T2DM. [source]

    Evaluation of apoptosis in cytologic specimens

    Viktor Shtilbans Ph.D.
    Abstract A hallmark of neoplasia is dysregulated apoptosis, programmed cell death. Apoptosis is crucial for normal tissue homeostasis. Dysregulation of apoptotic pathways leads to reduced cytocidal responses to chemotherapeutic drugs or radiation and is a frequent contributor to therapeutic resistance in cancer. The literature pertaining to detection of apoptotic pathway constituents in cytologic specimens is reviewed herein. Virtually all methods for detecting apoptosis, including classic cytomorphologic evaluation, TUNEL assay, immunocytochemistry, and gene sequence analysis, may be applied to cytologic samples as well as tissue. Components of both intrinsic and extrinsic apoptotic pathways have been studied, including many reports examining p53 and bcl-2, as well as studies of caspase inhibitory proteins XIAP and survivin, death receptors and ligands such as Fas, Fas-ligand, and TRAIL. p53 undergoes oncogenic alteration more than any other protein; its immunocytochemical detection almost always connotes loss of its physiologic role as an inducer of apoptosis in response to a damaged genome. Several reports establish cytologic sampling as being as useful as tissue sampling. In one respect cytologic sampling is superior to tissue sampling in particular, by allowing clinicians to repeat sampling of the same tumor before and after administration of therapy; a number of reports use this approach to attempt to predict tumor response by assaying the effect of chemotherapy on the induction of apoptosis. Diagn. Cytopathol. 2010;38:685,697. © 2010 Wiley-Liss, Inc. [source]

    Airborne fungal spores, pollen grains, and vegetable cells in routine Papanicolaou smears

    Ph.D., Rafael Martínez-Girón M.D.
    Abstract The objective was to demonstrate the presence of airborne fungal spores, pollen grains, and vegetable cells in smears and establish their significance. Microscopic examination was of smears stained by the Papanicolaou technique. We found several types of airborne spores (Alternaria, Exserohilum, Aspergillus, Cladosporium, Epicoccum, Curvularia, and Ascosmycete), pollen grains (Lilium, bullrush, Pinus, Acacia, hazelnut, and oak), and several types of vegetable cells. The existence of these structures may be due to intrinsic or to extrinsic contamination of the sample. Anemophilous fungi spores and pollen grains have been shown to possess great allergenic capacity. Pollen grains and vegetable cells may be mistaken for certain microorganisms or malignant cells. Diagn. Cytopathol. 2004;30:381,385. © 2004 Wiley-Liss, Inc. [source]

    The humanitarians' tragedy: escapable and inescapable cruelties

    DISASTERS, Issue 2010
    Alex De Waal
    Paradoxically, elements of cruelty are intrinsic to the humanitarian enterprise., This paper focuses on some of these. Escapable cruelties arise from technical failings, but the gradual professionalisation of the field and improvements in relief technologies mean that they have been significantly reduced in comparison to earlier eras. Other cruelties arise from clashes among rights, and the tensions inherent in trying to promote humanity amid the horrors of war. These are inescapable and constitute the ,humanitarians' tragedy'. Among them is the individual cruelty of failing to do good at the margin: a clash between the individual's impulses and ideals and the constraints of operating in constrained circumstances. This is a version of triage. In addition, there is the cruelty of compromising dearly-held principles when faced with other competing or overriding demands. There is also the cruelty whereby humanitarians feed victims' dreams that there is an alternative reality, which in fact cannot be attained. [source]

    Late Quaternary vadose carbonate diagenesis in coastal and desert dune and beach sands: is there a palaeoclimatic signal?

    Sue McLaren
    Abstract A study of the variation in cement amounts in aeolianite and sandy beach calcarenites that range in age from Holocene to Last Interglacial is used to assess whether a palaeoclimatic control on vadose diagenesis can be identi,ed. Examples are taken from modern-day arid to subhumid settings and represent a geographical distribution ranging from Libya and Oman, to the Mediterranean, the Caribbean and Mexico. The results indicate that a palaeoclimatic signal can be identi,ed in some deposits. However, in other sediments there is substantial variability in mean cement abundance within deposits as well as between these sand bodies. Moreover, many of the better cemented sediments are located in areas where there is accelerated diagenesis, such as in the sea spray zone, close to the groundwater table or near to a palaeosurface, rather than in climatically wet regions. The inference is that palaeoclimatic interpretations are substantially complicated by other factors that affect diagenetic processes and change. Therefore caution is needed when studying the role of climate in vadose diagenesis in the light of the effects of other intrinsic and extrinsic controls. This paper does not aim to provide a de,nitive comparison of sites from different climatic zones. The approach taken here is: (a) to see if there is an overall palaeoclimatic signal in the samples studied; (b) to use examples to illustrate how explanations/controls other than those relating to climate can account for the variabilities observed; and (c) if there is a climatic effect, to see if it is the main over-riding control on vadose diagenesis. The conclusions drawn from this research highlight that it is possible to misinterpret evidence if the study is approached with preconceived notions of simplistic relationships between diagenesis and climate. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    Structural Equations, Treatment Effects, and Econometric Policy Evaluation1

    ECONOMETRICA, Issue 3 2005
    James J. Heckman
    This paper uses the marginal treatment effect (MTE) to unify the nonparametric literature on treatment effects with the econometric literature on structural estimation using a nonparametric analog of a policy invariant parameter; to generate a variety of treatment effects from a common semiparametric functional form; to organize the literature on alternative estimators; and to explore what policy questions commonly used estimators in the treatment effect literature answer. A fundamental asymmetry intrinsic to the method of instrumental variables (IV) is noted. Recent advances in IV estimation allow for heterogeneity in responses but not in choices, and the method breaks down when both choice and response equations are heterogeneous in a general way. [source]

    Is postprandial hypertriglyceridaemia in relatives of type 2 diabetic subjects a consequence of insulin resistance?

    A. Kriketos
    Abstract Background, Higher postprandial triglyceride responses reported in first degree relatives of people with type 2 diabetes (REL) were postulated to be the result of an early, possibly intrinsic, defect in oral lipid handling. The postprandial triglyceride response to high fat meals (HFM) in normal subjects is reduced by the insulin response to dietary carbohydrate (CHO) in the meal. The aims of this study were to examine whether (1) insulin resistance is associated with an intrinsic defect in triglyceride handling in insulin-resistant REL and (2) insulin resistance is associated with altered triglyceride handling after HFM with high CHO content. Materials and methods, Postprandial responses to a HFM in normolipidaemic, normoglycaemic REL were compared with subjects without a family history of diabetes mellitus (CON). Over 6 h, the insulin, glucose, triglyceride and nonesterified fatty acid (NEFA) responses after a high fat (80 g fat), low CHO (HFM-LC; 20 g CHO, 4250 kJ) meal and a high fat, high CHO (HFM-HC; 100 g CHO, 5450 kJ) meal were examined. Results, The 10 (7F/3M) REL were significantly more insulin-resistant, determined by glucose infusion during a hyperinsulinaemic euglycaemic clamp than the 10 (5F/5M) CON (glucose infusion rate 44·6 ± 4·9 vs. 60·0 ± 4·8 µmol min,1 kg FFM,1, P = 0·037). Subjects were similar for age and body mass index (BMI). The triglyceride increments after the HFM-LC were similar in both, peaking at 180,240 min (,0·77 ± 0·11 mmol L,1), demonstrating no postprandial defect in REL, despite insulin resistance. There was a significantly lower postprandial triglyceride response in CON following the HFM-HC compared with the HFM-LC, but not in REL. In contrast, the higher insulin level during the HFM-HC was associated with significantly greater NEFA level suppression than in the HFM-LC (2·13 ± 0·51 vs. 0·70 ± 0·35 mmol L,1, P = 0·03), only in the REL. Conclusions, These results are inconsistent with a primary aetiological role for postprandial hypertriglyceridaemia in already insulin resistant type 2 diabetic REL, but raise the possibility that this potentially atherogenic manifestation is secondary to insulin resistance lessening VLDL production and/or release from the liver. [source]

    Evidence for RPE65-independent vision in the cone-dominated zebrafish retina

    Helia B. Schonthaler
    Abstract An enzyme-based cyclic pathway for trans to cis isomerization of the chromophore of visual pigments (11- cis -retinal) is intrinsic to vertebrate cone and rod vision. This process, called the visual cycle, is mostly characterized in rod-dominated retinas and essentially depends on RPE65, an all- trans to 11- cis -retinoid isomerase. Here we analysed the role of RPE65 in zebrafish, a species with a cone-dominated retina. We cloned zebrafish RPE65 and showed that its expression coincided with photoreceptor development. Targeted gene knockdown of RPE65 resulted in morphologically altered rod outer segments and overall reduced 11- cis -retinal levels. Cone vision of RPE65-deficient larvae remained functional as demonstrated by behavioural tests and by metabolite profiling for retinoids. Furthermore, all- trans retinylamine, a potent inhibitor of the rod visual cycle, reduced 11- cis -retinal levels of control larvae to a similar extent but showed no additive effects in RPE65-deficient larvae. Thus, our study of zebrafish provides in vivo evidence for the existence of an RPE65-independent pathway for the regeneration of 11- cis -retinal for cone vision. [source]

    Glutamate regulates retinal progenitors cells proliferation during development

    Rodrigo A. P. Martins
    Abstract The precise coordination of cell cycle exit and cell fate specification is essential for generating the correct proportion of retinal cell types during development. The decision to exit the cell cycle is regulated by intrinsic and extrinsic cues. There is growing evidence that neurotransmitters can regulate cell proliferation and cell fate specification during the early stages of CNS development prior to the formation of synaptic connections. We found that the excitatory neurotransmitter glutamate regulates retinal progenitor cell proliferation during embryonic development of the mouse. AMPA/kainate and N -methyl- d -aspartate receptors are expressed in embryonic retinal progenitor cells. Addition of exogenous glutamate leads to a dose-dependent decrease in cell proliferation without inducing cell death or activating the p53 pathway. Activation of AMPA/kainate receptors induced retinal progenitor cells to prematurely exit the cell cycle. Using a replication-incompetent retrovirus to follow the clonal expansion of individual retinal progenitor cells, it was observed that blockade of AMPA/kainate receptors increased the proportion of large clones, showing that modulation of endogenous glutamatergic activity can have long-term consequences on retinal cell proliferation. Real time reverse transcriptase-polymerase chain reaction and immunoblot analyses demonstrated that glutamate does not alter the levels of the mRNA and proteins that regulate the G1/S-phase transition. Instead, the activity of the Cdk2 kinase is reduced in the presence of glutamate. These data indicate that glutamate regulates retinal progenitor cell proliferation by post-translational modulation of cyclin/Cdk2 kinase activity. [source]

    Gene networks controlling early cerebral cortex arealization

    Antonello Mallamaci
    Abstract Early thalamus-independent steps in the process of cortical arealization take place on the basis of information intrinsic to the cortical primordium, as proposed by Rakic in his classical protomap hypothesis [Rakic, P. (1988)Science, 241, 170,176]. These steps depend on a dense network of molecular interactions, involving genes encoding for diffusible ligands which are released around the borders of the cortical field, and transcription factor genes which are expressed in graded ways throughout this field. In recent years, several labs worldwide have put considerable effort into identifying members of this network and disentangling its topology. In this respect, a considerable amount of knowledge has accumulated and a first, provisional description of the network can be delineated. The aim of this review is to provide an organic synthesis of our current knowledge of molecular genetics of early cortical arealization, i.e. to summarise the mechanisms by which secreted ligands and graded transcription factor genes elaborate positional information and trigger the activation of distinctive area-specific morphogenetic programs. [source]