bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic unpredictable stress impairs long‐term potentiation in rat hippocampal CA1 area and dentate gyrus in vitro
Authors: Alfarez Deborah N. , Joëls Marian , Krugers Harm J.
Published: May 2003

Rises in corticosteroid levels, e.g. after acute stress, impair synaptic plasticity in the rat hippocampus when compared with the situation where levels are basal, i.e. under rest. We here addressed the question whether basal and raised levels of corticosterone affect synaptic plasticity similarly in animals that experienced chronic stress prior to corticosterone application. To this end, rats were exposed to a 21‐day variable stress paradigm. Synaptic plasticity was examined in vitro in the dentate gyrus and CA1 hippocampal region, 24 h after exposure to the last stressor, i.e. when corticosterone levels are basal (low). First we observed that long‐term potentiation was greatly impaired in both CA1 and dentate gyrus after 3 weeks of exposure to variable stress, when recorded under conditions where plasma corticosterone levels are low. Second, administration of 100 nm corticosterone in vitro reduced synaptic plasticity in CA1 of control rats, but induced no further impairment of synaptic plasticity in chronically stressed rats. Third, in the dentate gyrus, corticosterone incubation did not affect synaptic plasticity in slices from both control and stressed animals. We conclude that: (i) exposure to chronic variable stress per se reduces synaptic plasticity both in CA1 and dentate gyrus; and (ii) acute rises in corticosterone level induce no additional impairment of synaptic plasticity in the CA1 region of chronically stressed rats. It is tempting to speculate that the stress‐induced reduction of hippocampal efficacy provides a cellular substrate for cognitive deficits in hippocampus‐dependent learning tasks seen after prolonged exposure to stressful events.
Reduced spinal cord sensitization to C‐fibre stimulation in mice over‐expressing galanin
Authors: Grass Stefan , Crawley Jacqueline N. , Xu Xiao‐Jun , Wiesenfeld‐Hallin Zsuzsanna
Published: May 2003

The neuropeptide galanin may have a role in spinal nociception. In this study, we examined the excitability of the flexor reflex and its sensitization by repetitive stimulation of nociceptive C‐fibres in anaesthetized mice that over‐express galanin. No difference was seen between over‐expressing galanin and wild‐type mice in the magnitude of the baseline flexor reflex. Repetitive conditioning stimulation of C‐fibres (10 stimuli at 1 Hz) produced a gradual increase in reflex magnitude during the conditioning stimulation (wind‐up), as well as an increase in spinal reflex excitability after the termination of the stimulus train (central sensitization) in wild‐type mice. Although the wind‐up did not differ between over‐expressing galanin and wild‐type mice, the magnitude of central sensitization was significantly reduced in the over‐expressing galanin mice (24 ± 13% peak increase compared with 164 ± 65% in the wild‐type). Intrathecal administration of M35, a galanin receptor antagonist, markedly enhanced central sensitization in over‐expressing galanin mice in association with C‐fibre conditioning stimulation, while having no effect in wild‐type mice. These results provide further electrophysiological evidence for an inhibitory function of galanin in modulation of central sensitization in response to C‐fibre stimulation.
Morphological changes in hippocampal dentate gyrus synapses following spatial learning in rats are transient
Authors: Eyre Mark D. , Richter‐Levin Gal , Avital Avi , Stewart Michael G.
Published: May 2003

The hippocampus is believed to play a crucial role in the formation of memory for spatial tasks. In the present study quantitative electron microscopy was used to investigate morphological changes in the hippocampal dentate gyrus of 3‐month‐old male rats at 3, 9 and 24 h after training to find a hidden platform in a Morris water maze. Average escape latency (time taken to reach the platform) in all trained groups decreased progressively with increased training but data from a probe trial (quadrant analysis test) at the end of training indicated that only animals in the 9‐ and 24‐h groups, not the 3‐h group, displayed significant retention of platform location. Unbiased stereological methods were used to estimate synapse and neuronal density at each time point after training. The majority of synapses had unperforated postsynaptic densities, were localized on small dendritic spines and were classed as axo‐spinous. In comparison to age‐matched untrained rats, significant but transient increases were observed in axo‐spinous synapse density and synapse‐to‐neuron ratio 9 h after the start of training, but not at earlier (3 h) or later (24 h) times. These changes at 9 h post‐training were accompanied by transient decreases in both mean synaptic height and area of postsynaptic density. No such changes were observed in an exercise‐matched control group of rats, indicating that the transient synaptic changes in the dentate gyrus are most likely to be specifically related to processes involved in memory formation for the spatial learning task.
Presence of functional vasopressin receptors in spinal ventral horn neurons of young rats: a morphological and electrophysiological study
Authors: Liu X. , Tribollet E. , Ogier R. , Barberis C. , Raggenbass M.
Published: May 2003

The objective of the present work was double. (i) Light microscopic autoradiography was used to determine the distribution of vasopressin and oxytocin binding sites in the spinal cord of rats. (ii) Whole‐cell recordings were performed in lumbar spinal cord slices in order to assess whether these receptors are functional, whether they are located pre‐ or postsynaptically and whether they are present in motoneurons. In newborns, vasopressin binding sites of the V1a type were present in all laminae of the central gray at all segmental levels, whereas oxytocin binding sites were found only in the superficial layers of the dorsal horn. In adults, binding sites for both neuropeptides were also present, but were less dense. The dissociation constants for vasopressin were similar in newborns and adults. Whole‐cell recordings showed that in identified motoneurons vasopressin exerted a direct effect, by inducing a membrane depolarization or by generating a sustained inward current, and an indirect effect, by enhancing glycinergic and GABAergic inhibitory transmission. Vasopressin‐induced facilitation of inhibitory transmission could also be demonstrated in unidentified ventral horn neurons. All these effects were mediated by V1a but not V1b receptors. In some neurons, glycinergic transmission was also facilitated by a selective oxytocin receptor agonist. Our data, together with data obtained previously in brainstem motor nuclei, suggest that vasopressin of hypothalamic origin could play a role in motricity. The neuropeptide could act as a neuromodulator, because it would not directly activate motoneurons, but rather render them more responsive to incoming excitatory inputs. Vasopressin may thus act as a regulator of muscular force.
Tumor necrosis factor receptor type‐1 in sensory neurons contributes to induction of chronic enhancement of inflammatory hyperalgesia in rat
Authors: Parada Carlos A. , Yeh Jenny J. , Joseph Elizabeth K. , Levine Jon D.
Published: May 2003

Carrageenan‐induced inflammatory pain lasting hours to days produces a protein kinase C epsilon (PKCɛ)‐dependent ‘primed’ state lasting several weeks, during which time injection of prostaglandin E2 induces hyperalgesia which is markedly enhanced and prolonged compared to PGE2‐induced hyperalgesia in normal ‘unprimed’ rats. In the present study, we demonstrate that while inhibition of prostaglandin synthesis and antagonism of β2‐adrenergic receptors markedly attenuated the hyperalgesia induced by carrageenan, these interventions did not affect hyperalgesic priming. Tumor necrosis factor‐α (rat recombinant; rrTNFα), another mediator of carrageenan‐induced inflammation, alone produced hyperalgesia and priming, which were attenuated and prevented, respectively, by intrathecal administration of antisense to PKCɛ. Inhibition of TNFα with thalidomide or a rat polyclonal anti‐TNFα antibody attenuated carrageenan‐induced hyperalgesia and prevented priming. Intrathecal administration of antisense to tumour necrosis factor receptor type‐1 (TNFR1) reduced the level of TNFR1 transported toward the peripheral terminals of sensory neurons, and attenuated both carrageenan‐ and rrTNFα‐induced priming. Acute hyperalgesia induced by carrageenan or rrTNFα remained intact in animals treated with TNFR1 antisense. Our results demonstrate that the generation of the primed state does not require production of hyperalgesia and that TNFα, which is generated during acute inflammation, can act on sensory neurons to induce hyperalgesic priming by activating neuronal PKCɛ.
A subpopulation of rats show social and sleep–waking changes typical of chronic neuropathic pain following peripheral nerve injury
Authors: Monassi Claudia R. , Bandler Richard , Keay Kevin A.
Published: May 2003

Neuropathic conditions for which treatment is sought, the so‐called chronic pain syndrome, are characterized usually by complex behavioural disturbances as well as pain. In this study we evaluated whether social behavioural and sleep disruptions occurred after nerve injury. Before and after chronic constriction of the sciatic nerve, resident–intruder and sleep–wake cycles, as well as mechanical and thermal allodynia/hyperalgesia, were quantified. Sciatic nerve injury in all animals reduced withdrawal thresholds to tactile and thermal (cold) stimuli. Resident–intruder and sleep–waking behaviours were altered in some but not all animals. One group (30%, ‘persistent change’) had enduring reductions in dominant behaviour to an intruder and decreased slow‐wave sleep and increased wakefulness during both light and dark cycles. Another group (25%, ‘recovery’) had a transient reduction in dominant behaviours and decreased slow‐wave sleep and increased wakefulness during only the light cycle. In a third group (45%, ‘no effect’) resident–intruder and sleep–waking behaviours remained normal. Our finding that the degree of ‘pain’ as inferred from the allodynia/hyperalgesia was identical in all animals suggests that the alterations to resident–intruder and sleep–wake cycles were independent of the level of sensory disturbance. An absence of correlation between intensity of sensory disturbances and measures of disability (loss of sleep, familial/social problems) is also characteristic of human neuropathic pain. These data indicate that: (i) in a subpopulation of animals sciatic injury results in two of the major complex behavioural changes which are characteristic of neuropathic pain in humans; (ii) testing only for allodynia and hyperalgesia is not sufficient to detect this subpopulation.
Expression of neuroserpin in the visual cortex of the mouse during the developmental critical period
Authors: Wannier‐Morino Patrizia , Rager Günter , Sonderegger Peter , Grabs Detlev
Published: May 2003

The neuronal serine protease inhibitor neuroserpin is widely expressed in the developing and adult brain. In the neocortex, neuroserpin is displayed particularly during the period of synaptic specification and refinement, indicating a role as modulator of extracellular proteolytic processes. The synaptic connections of the visual system of the mouse are shaped during early postnatal life by an activity‐dependent process. We have studied the expression of the neuronal serine protease inhibitor neuroserpin in the primary visual cortex of mice from birth until the end of the critical period by means of reverse transcription polymerase chain reaction and in situ hybridization. The localization and the level of expression were constant throughout this period. Monocular deprivation with an eyelid sutured induced a decrease in neuroserpin expression in neurons of area 17 after 1 week of deprivation, the decrease being more pronounced on the side contralateral to the closed eye. The expression of neuroserpin in the visual cortex during the critical period and its decrease in parallel to the refinement of synaptic contacts after visual deprivation suggests a regulative role of neuroserpin on these processes.
Somatostatin receptor 2 knockout/lacZ knockin mice show impaired motor coordination and reveal sites of somatostatin action within the striatum
Authors: Allen Jeremy P. , Hathway Gareth J. , Clarke Neil J. , Jowett Mike I. , Topps Stephanie , Kendrick Keith M. , Humphrey Patrick P. A. , Wilkinson Lawrence S. , Emson Piers C.
Published: May 2003

The peptide somatostatin can modulate the functional output of the basal ganglia. The exact sites and mechanisms of this action, however, are poorly understood, and the physiological context in which somatostatin acts is unknown. Somatostatin acts as a neuromodulator via a family of five 7‐transmembrane G protein‐coupled receptors, SSTR1–5, one of which, SSTR2, is known to be functional in the striatum. We have investigated the role of SSTR2 in basal ganglia function using mice in which Sstr2 has been inactivated and replaced by the lacZ reporter gene. Analysis of Sstr2lacZ expression in the brain by β‐galactosidase histochemistry demonstrated a widespread pattern of expression. By comparison to previously published in situ hybridization and immunohistochemical data, Sstr2lacZ expression was shown to accurately recapitulate that of Sstr2 and thus provided a highly sensitive model to investigate cell‐type‐specific expression of Sstr2. In the striatum, Sstr2 expression was identified in medium spiny projection neurons restricted to the matrix compartment and in cholinergic interneurons. Sstr2 expression was not detected in any other nuclei of the basal ganglia except for a sparse number of nondopaminergic neurons in the substantia nigra. Microdialysis in the striatum showed Sstr2‐null mice were selectively refractory to somatostatin‐induced dopamine and glutamate release. In behavioural tests, Sstr2‐null mice showed normal levels of locomotor activity and normal coordination in undemanding tasks. However, in beam‐walking, a test of fine motor control, Sstr2‐null mice were severely impaired. Together these data implicate an important neuromodulatory role for SSTR2 in the striatum.
Interneurons are the local targets of hippocampal inhibitory cells which project to the medial septum
Authors: Gulyás A. I. , Hájos N. , Katona I. , Freund T. F.
Published: May 2003

A subset of GABAergic neurons projecting to the medial septum has long been described in the hippocampus. However, the lack of information about their local connectivity pattern or their correspondence with any of the well‐established hippocampal interneuron types has hampered the understanding of their functional role. Retrograde tracing combined with immunostaining for neurochemical markers in the adult rat hippocampus showed that nearly all hippocampo‐septal (HS) neurons express somatostatin (>95%) and, in the hilus and CA3 stratum lucidum, many contain calretinin (>45%). In contrast, in stratum oriens of the CA1 and CA3 subfields, the majority of HS neurons contain somatostatin (>86%) and calbindin (>73%), but not calretinin. Because somatostatin‐positive hippocampal interneurons have been most extensively characterized in the stratum oriens of CA1, we focused our further analysis on HS cells found in this region. In 18–20‐day‐old rats, intracellularly filled CA1‐HS cells had extensive local axon collaterals crossing subfield boundaries and innervating the CA3 region and the dentate gyrus. Electron microscopic analysis provided evidence that the axon terminals of CA1‐HS cells form symmetrical synapses selectively on GABAergic interneurons, both locally and in the CA3 region. In addition, double retrograde labelling experiments revealed that many CA1‐HS neurons of the dorsal hippocampus also have collateral projections to the ventral hippocampus. Thus, CA1‐HS cells innervate inhibitory interneurons locally and in remote hippocampal regions, in addition to targeting mostly GABAergic neurons in the medial septum. This dual projection with striking target selectivity for GABAergic neurons may be ideally suited to synchronize neuronal activity along the septo‐hippocampal axis.
Neural correlates of memorized associations and cued movements in archistriatum of the domestic chick
Authors: Aoki Naoya , Izawa Ei‐Ichi , Yanagihara Shin , Matsushima Toshiya
Published: May 2003

The archistriatum mediates a neural pathway from the medial part of intermediate hyperstriatum ventrale (in the dorsal pallium) to the lobus parolfactorius (in the medial striatum), thus is possibly involved in memory formation in the domestic chick. To elucidate the functional roles, we examined single neuron activities from archistriatum in unconstrained chicks during execution of a GO/NOGO task. In this task, a brief motor sound was given as initial cue, and immediately followed by presentation of a coloured bead. Chick was required to recall the memorized associations between the colour and reward, and pecked at the bead to gain food after a delay (GO trials) or stayed not pecking (NOGO trials). The ventral part of intermediate archistriatum proved to contain a group of neurons that selectively responded to the reward‐associated colours before the reward was actually presented, possibly coding the memorized associations. Another group of neurons fired during the reward period, thus could code aspects of the food reward. Yet another group of neurons started to fire immediately on the cue sound and prior to the cued movements nonselectively in both GO and NOGO trials, thus could be involved in the sensori‐motor link between the sound and the targeted body movements. It is concluded that even a subregion of archistriatum contains diverse neural codes for memorized associations and food rewards, and neural codes of movements cued by sounds, suggesting that archistriatum is a complex of different functional systems, possibly corresponding to striatum, limbic amygdala, and prefrontal cortex in mammals.
Early establishment of multiple release site connectivity between interneurons and pyramidal neurons in the developing hippocampus
Authors: Groc Laurent , Gustafsson Bengt , Hanse Eric
Published: May 2003

The strength of the synaptic transmission between two neurons critically depends on the number of release sites connecting the neurons. Here we examine the development of connectivity between γ‐aminobutyric acid (GABA)ergic interneurons and CA1 pyramidal neurons in the hippocampus. GABAergic postsynaptic currents (PSCs) were recorded in whole‐cell voltage‐clamped CA1 pyramidal neurons. By comparing spontaneous and miniature (action potential‐independent) GABAergic PSCs, we found that multiple release site connectivity is established already at the first postnatal day and that the degree of connectivity remains unaltered into adulthood. During the same time there is a dramatic increase in the number of GABAergic synapses on each pyramidal neuron as indicated by the increase in frequency of miniature GABAergic PSCs. These results indicate that during development a given interneuron contacts an increasing number of target pyramidal neurons but with the same multiple release site connectivity. It has been shown previously that the connectivity between CA3 and CA1 pyramidal neurons is initially restricted to one release site, and develops gradually. The present result thus suggests different mechanisms to govern the maturation of excitatory and inhibitory synaptic transmissions.
Bioactivity of a peptide derived from acetylcholinesterase: electrophysiological characterization in guinea‐pig hippocampus
Authors: Bon Christelle L. M. , Greenfield Susan A.
Published: May 2003

Acetylcholinesterase is well known to have noncholinergic functions. Only recently, however, has the salient part been identified of the molecule responsible for these nonclassical actions, a peptide of 14 amino acids towards the C‐terminus of acetylcholinesterase. The aim of this study was to test the bioactivity of this ‘acetylcholinesterase‐peptide’ using intracellular recordings in guinea‐pig hippocampal slices. In the presence of tetrodotoxin, acetylcholinesterase‐peptide alone affected neither the membrane potential nor the input resistance of CA1 neurons; however, a modulatory action was observed, as a concentration‐dependent decrease of N‐methyl‐d‐aspartic acid‐induced depolarization. When calcium potentials were elicited by a depolarizing current pulse, application of acetylcholinesterase‐peptide increased or reduced the degree of calcium spike firing in, respectively, the presence or absence of the N‐methyl‐d‐aspartic acid antagonist d(–)‐2‐amino‐5‐phosphonopentanoic acid. In contrast, a peptide derived from the equivalent region of butyrylcholinesterase, which also hydrolyses acetylcholine, had no effect. In conclusion, acetylcholinesterase‐peptide has a selective bioactivity in the hippocampus; it could thus offer new ways of targeting mechanisms of calcium‐induced neurotoxicity.
Micromixers to produce cosmetic emulsions
Authors: Tromeur M. , Mahé C. , Schwesinger N. , Tranchant J.‐F.
Published: May 2003

Synopsis

In the cosmetics industry, emulsions play a key‐role in active solubilization and texture/efficacy optimization. However, depending on their physico‐chemical properties, the active ingredients are often more stable in a single phase: for example, Vitamin A is more stable in an oily phase than in a water phase.

We have developed a special mixing device which produces an emulsion in the body of the pump, immediately before application on the skin. The mixing unit consists of two silicon chips. Each chip has several Y‐shaped microchannels and intersections etched on its upper surface. When the two etched surfaces are bonded together, they produce series of interconnecting micromixing elements which permit the repeat mixing of the two phases, thus producing an extremely homogenous emulsion. These micromixers require carefully designed formulae in which the physico‐chemical properties of each raw material are essential to obtain a spontaneous emulsion. This device has been incorporated into a spray pack and optimized to deliver the spontaneous emulsion when finger pressure is applied.
A keratinocytes–melanocytes coculture system for the evaluation of active ingredients' effects on UV‐induced melanogenesis
Authors: Nicolaÿ J.‐F. , Levrat B.
Published: May 2003

Synopsis

A new experimental design, more reliable for in vitro testing of active ingredients' effect on ultraviolet (UV)‐induced melanogenesis has been carried out. It uses a bicompartmental coculture system where cell communication between keratinocytes and melanocytes can take place. Thus, this experimental situation enables to monitor the effect of biological agents released by both cell types on melanogenesis and the interference of tested compounds with this ‘paracrine linkage’. Experiments with UVB‐irradiated cocultures show the importance of cell communication in the melanogenic response. In this model, the endogenous mediator, nitric oxide (NO), increased melanin production. Different compounds were tested in the coculture system, and comparison with data obtained from irradiated monocultures of melanocytes enables to distinguish a specific effect on cell communication. In addition, this more close‐to‐reality experimental model proved to provide a valuable first approach for the assessment of the ‘bioavailability’ of the tested substances. Finally, the effect of an innovative photoprotective agent capable of ‘boosting’ UV‐induced melanogenic cell communication is presented.
Enzymatic production of atranorin: a component of the oak moss absolute by immobilized lichen cells
Authors: Vicente C. , Fontaniella B. , Millanes A. M. , Sebastián B. , Legaz M. E.
Published: May 2003

Synopsis

Cells of the lichen, Evernia prunastri, immobilized in calcium alginate were able to produce the depside atranorin from acetate. The synthesis of the depside was enhanced by molecular oxygen and NADH. This enhancement suggested the participation of an oxidase and an alcohol dehydrogenase to produce an aldehyde‐substituted phenolic acid, hematommic acid, as the most probable precursor of atranorin. The participation of both enzymes was confirmed by loading immobilized cells with sodium azide, an inhibitor of several metallo‐oxidases, and pyrazole, an inhibitor of alcohol dehydrogenase, which impeded atranorin production and accumulated β‐methyl orsellinate (after azide loading) or its alcohol derivative (after pirazole treatment).
Irritation cutanée et vitesse de propagation d'ondes ultrasonores
Authors: Uhoda E. , Piérard G. E.
Published: May 2003

Synopsis

Cutaneous irritation is a stereotyped response of the skin to any physical or chemical insult. Its main manifestations encompass inflammatory erythema and an alteration of the cutaneous microrelief showing increased roughness, dehydration and erratic desquamation. Several instrumental methods can indirectly assess the issues of cutaneous irritation on human stratum corneum.

The aim of the present study was to measure the speed of propagation of ultrasound shear waves in the skin irritated by anionic surfactants. The study was performed in 25 healthy subjects of both sexes. Occlusive patches of a 10% solution of anionic surfactants were applied to a forearm of each volunteer. The other forearm served as an untreated control site. Patches remained in place for 24 h. Three hours later, another patch was placed again for 21 h. Resonance running time measurements (RRTM) of the ultrasound shear wave were performed using a Reviscometer® RVM 600. Measurements were performed at entry in the study and 2 days after removing the second patch.

Desquamative xerosis was obvious at the sites patched with the surfactant solution. RRTM values were significantly (P < 0.0001) lower than those at the control site. Hence, the speed of propagation of ultrasound shear waves was shown to be increased at an irritated site compared to an intact site.

In conclusion, this study shows that the propagation speed of ultrasounds is influenced by the skin surface nature, being considerably increased in skin altered by surfactants.
In vivo study of the physiological impact of stratum corneum sampling methods
Authors: Rosado C. , Rodrigues L. M.
Published: May 2003

Synopsis

Background: Several methods have been developed to study in vivo the stratum corneum with minimal ‘invasion’. Cyanoacrylate adhesives employed in skin surface biopsy (SSB) and tape stripping are commonly used techniques that can be applied to study the different layers of the epidermis or even to permeation studies. However, depending on the type of adhesive tape used and pressure applied, different information is gathered. Aim: The purpose of this study was to identify and compare the impact of both techniques in the normal skin physiology to further establish its potential usefulness and limitations. Methods: Alterations were focused on basic structural related properties, such as epidermal barrier function (assessed by transepidermal water loss evaporimetry) and flow related changes (by laser Doppler velocimetry and colourimetry). Results/conclusions: Results indicate a more pronounced impact of SSB than that of tape stripping, attributable to the removal of a thicker layer of cells. The intertechnique correlation coefficients were good between transepidermal water loss and colourimetry, but poorer between these techniques and laser doppler flowmetry, which probably reflects the difficulties associated with this technique.
Multicentre comparison of skin hydration in terms of physical‐, physiological‐ and product‐dependent parameters by the capacitive method (Corneometer CM 825)
Authors: Heinrich U. , Koop U. , Leneveu‐Duchemin M.‐C. , Osterrieder K. , Bielfeldt S. , Chkarnat C. , Degwert J. , Häntschel D. , Jaspers S. , Nissen H.‐P. , Rohr M. , Schneider G. , Tronnier H.
Published: May 2003

Synopsis

A multicentre study for measuring skin hydration with 349 volunteers was carried out in six different laboratories. The purpose of the study was to investigate physical‐, physiological‐ and product‐dependent parameters of three test emulsions (base, base + moisturizer and base + moisturizer + lipids) in a double‐blind study. A comparison between analogous and digital sensor technology of the Corneometer CM825 was examined. Here, a clear relationship between both sensor types could be highlighted. A vital point of the study was the division of the test subjects according to their skin type. To get more objective limits for three different skin types – very dry, dry and normal skin – visual expert evaluation, self‐assessment and hydration measurements were analysed by means of statistical methods. The moisture‐related skin types were determined as follows: very dry skin was characterized with corneometer units below 30, dry skin between 30 and 40 and normal skin higher than 40 a.u. (arbitrary units). The efficacy of the three test emulsions was examined in relation to the mentioned skin types. Analysing the measured data of all test centres, a clear dependency of skin physiology (skin type) and product efficacy became evident. The drier the skin, the higher the increase of hydration. The product performance of the three test emulsions compared to the untreated control resulted in a significant increase of skin hydration in all measuring centres. The evaluation of a product ranking showed a good differentiation between the basic emulsion and the two other products. An increase of efficacy by adding lipids could be observed in four of six centres. The important influence of the skin type of the volunteers on the degree of product performance, as demonstrated in this study, should be especially considered when drawing up guidelines for efficacy testing.
In vitro stimulation of synthesis of key DEJ constituents in a reconstructed skin model: a quantitative study
Authors: Reymermier C. , Guezennec A. , Branka J. E. , Guesnet J. , Perrier E.
Published: May 2003

Synopsis

Fighting skin ageing is one of the major targets of cosmetology research. However, traditional approaches to skin ageing using stimulation of basal keratinocyte proliferation and fibroblastic neosynthesis appear today to be incomplete, particularly considering changes occurring at the dermal–epidermal junction (DEJ) during the course of ageing. Unfortunately, the lack of in vitro model limits the exploration process of the phenomena of DEJ ageing, and particularly the evaluation of the changes of key components, that are laminin‐5, types IV and VII collagens. The aim of this work was to provide an in vitro model of reconstructed skin, base for new dosage and identification methods for qualitative and quantitative analysis of the key components of DEJ. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) and quantitative RT‐PCR were successfully applied to this model to analyse mRNA of laminin‐5, types IV and VII collagens and their variation in ‘young’ and ‘mature’ reconstructed skin model. Finally, this model was used to test the activity of ingredients for cosmetic application, in order to modulate the expression of the major components of DEJ. To conclude, we demonstrated that this in vitro model of reconstructed young and mature skin provides a useful tool to get into the biology of the DEJ, key structure of the skin, and specifically into its dynamic changes during the ageing process.
Trends in stratum corneum research and the management of dry skin conditions
Authors: Rawlings A. V.
Published: May 2003

Synopsis

The structure, composition, formation and function of the stratum corneum have been the subject of intense research over the last few decades. As has become apparent, stratum corneum barrier function is not only dependent on one single component but also on its total architecture. Recent developments in understanding lipid composition have led to a new ceramide nomenclature system, a new proposal for a molecular model of the interactions between ceramides, cholesterol and fatty acids, and the demonstration of the presence of crystalline orthorhombic and gel hexagonal lipid phases in the stratum corneum. Linoleate‐containing ceramide one, now known as CER EOS, have been shown to be essential for the formation of the 13 nm long periodicity phase (LPP) observed by electron microscopy and X‐ray diffraction studies, whereas long‐chain fatty acids are important for the formation of the crystalline lipid phases essential for barrier function. The role of the corneocyte envelope, its constituent proteins and its transglutaminase‐mediated maturation processes have been shown to be essential for good skin condition. Several proteases may have a role in corneodesmolysis, particularly serine and cathepsin‐like enzymes. Novel filaggrin polymorphisms have been identified that may be involved in the expression of a dry skin phenotype. Disturbances in lipid packing states, reduction in ceramide levels (particularly the phytosphingosine‐containing ceramides), reductions in the levels of long‐chain fatty acids and loss of the LPP largely account for the perturbations in lipid structure that occur in dry skin. The reduced corneodesmolysis that occurs in this xerotic skin disorder is now well accepted and is caused by reductions in the levels and activities of stratum corneum proteases together with elevated levels of corneodesmosomal glycoproteins in the superficial layers of the stratum corneum. Additionally, increased levels of fragile corneocytes are associated with reduced transglutaminase activity and corneocyte envelope cross‐linking events. However, in comparison with the advances in our understanding of the textural changes that occur in dry skin, the somatosensory changes are poorly understood and the itching associated with dry skin is still an under‐researched area. The unique biosensor role of the stratum corneum essential for a competent natural moisturizing barrier may also have a role to play in the action of anti‐ageing technologies by controlling the expression and secretion of epidermal cytokines and growth factors. Technologies to treat the surface textural skin problems, enhance the differentiation process, particularly lipid biosynthesis, and to control the somatosensory problems in dry skin have received much attention in the last decade. This paper will review the state of the art of stratum corneum biology and the trends in the management of dry skin.
Chronic Daily Headaches: Clinical Profile in Indian Patients
Authors: Chakravarty A
Published: May 2003

Chronic daily headache (CDH) remains a relatively unexplored entity in India. Misconceptions are common, unnecessary investigations often done and inappropriate therapy prescribed. Analgesic overuse is seldom recognized. The present report appears to be the first of its kind from India. CDH has been defined as headaches occurring more than 15 days per month for more than 3 months (secondary causes excluded). Over 2 years (1998-1999) 849 cases (49.6% of all primary headaches) were seen. More than 1 year's follow-up data were available in 205 subjects (M 34; F 171). The distribution of these was as follows: (i), chronic tension-type headache (CTH), 33 (16.1%); (ii), chronic/transformed migraine (TM), 169 (82.4%); (iii), new persistent CDH, 3 (1.5%). There were 169 cases of TM (M:F 1:4.7; age 26-58 years). History of past episodic migraine was present in all. Transformation had been gradual (89.4%) or acute (10.6%). Possible factors in transformation included psychological stress (44.4%), analgesic overuse (28.4%), ergot overuse (4.1%). HRT seemed to be implicated in three female subjects. Analgesic overuse was limited between intake of 600 and 2400 mg of aspirin equivalent per day (mean 735 mg). Ergot overuse varied between 1 and 3 mg/day of ergotamine for ≥ 3 days/week. With medical therapy approximately 70% TM and 40% CTH patients noted significant improvement. About 80% of these relapsed on therapy withdrawal. CDH in India is not uncommon. Analgesic/ergot overuse needs to be recognized early. The average dose of analgesic implicated in CDH seems much less compared with that reported in the West.
Epidemiological and Clinical Characteristics of Migraine and Tension Type Headache in 1146 Females in Kayseri, Turkey
Authors: Köseoglu E , Naçar M , Talaslioglu A , çetinkaya F
Published: May 2003

In a female population of Turkey (1146 adult females), some epidemiological and clinical characteristics of migraine and tension type headache and their subtypes were investigated. The relation of the headache severity to clinical characteristics were inquired.

Migraine prevalence was found to be statistically higher in the 35-44 years age group ( P < 0.01) and those who were university graduates ( P < 0.001), married ( P < 0.01) and living in urban areas ( P < 0.01). Tension type headache was found to be higher in the 45-64 years age group ( P < 0.05). Chronic tension type headache patients were found to be older than episodic type ( P < 0.01) and frequently were in the lowest education level ( P < 0.05).

Presence of impact on daily activities because of the severity of headache was found to be related to aggravation by physical activities ( P = 0.001) in tension type headache, with no clinical characteristics in migraine headache and on consideration of all headache patients with throbbing nature ( P < 0.05), aggravation on physical activities ( P = 0.001), nausea ( P < 0.01), vomiting ( P < 0.05) and phonophobia ( P < 0.05).
Migrainous Cerebral Infarction in the Sagrat Cor Hospital of Barcelona Stroke Registry
Authors: Arboix A , Massons J , García-Eroles L , Oliveres M , Balcells M , Targa C
Published: May 2003

Nine of 2000 consecutive stroke patients included in the Sagrat Cor Hospital of Barcelona Stroke Registry over a 10-year period fulfilled the strictly defined International Headache Society criteria for migrainous stroke and in whom other causes of stroke were ruled out. They accounted for 13% of all first-ever ischaemic stroke of unusual cause. Migrainous stroke was more common in women (67%) and in patients aged ≤ 45 years (78%) compared to the remaining ischaemic strokes of unusual cause. No patient died during hospital stay and 67% were symptom-free at discharge. In the multivariate analysis, nausea or vomiting (odds ratio (OR) 8.40, 95% confidence interval (CI) 1.49-47.21) and age (OR 0.95, 95% CI 0.91-0.99) were predictors of migrainous stroke. Migrainous stroke is a rare entity. Vascular risk factors are uncommon and the prognosis is generally good. Patients with migrainous stroke present some different clinical features from other ischaemic strokes of unusual aetiology.
Nociceptive Temporalis Inhibitory Reflexes Evoked by Co2-Laser Stimulation in Tension-Type Headache
Authors: de Tommaso M , Guido M , Libro G , Losito L , Sciruicchio V , Specchio LM , Puca F
Published: May 2003

The aim of the study was to evaluate the laser-induced suppression periods of the temporalis muscle in patients with tension-type headache, compared with the pattern of temporalis activity suppression induced by electrical stimulation.

Fifteen patients with chronic and 10 with episodic tension-type headaches were selected. Suppression periods were recorded simultaneously from both temporalis muscles using both electrical stimuli and CO2-laser stimuli.

A significant reduction in the later electrically induced suppression period was found in both tension-type headache groups. Laser stimulation induced a first suppression period (LSP1) with a latency of about 50 ms in all patients. The features of LSP1 were similar across groups.

The LSP1 should correspond to the first suppression period induced by electrical stimulus, which is partly a nociceptive response, whereas the second period seemed negligibly linked with the activation of pain-related afferents, though probably their activation may contribute to increase the reflex duration and to emphasize abnormalities in tension-type headache.
Migraine and Tension-Type Headache in Croatia: A Population-Based Survey of Precipitating Factors
Authors: Zivadinov R , Willheim K , Sepic-Grahovac D , Jurjevic A , Bucuk M , Brnabic-Razmilic O , Relja G , Zorzon M
Published: May 2003

The careful monitoring of the trigger factors of headache could be an important step in treatment, because their avoidance may lessen the frequency and severity of attacks. Furthermore, they may provide a clue to the aetiology of headache. The aim of the present study was to estimate the prevalence of tension-type headache (TTH) and to establish the frequency of precipitating factors in subjects with migraine and TTH in the adult population of Bakar, County of the Coast and Gorski Kotar, Croatia. Another important purpose of the study was to examine the relationship of the precipitating factors with migraine and TTH, and with migraine subtypes: migraine with aura (MA) and migraine without aura (MO). We performed a population-based survey using a ‘face-to-face door-to-door’ interview method. The surveyed population consisted of 5173 residents aged between 15 and 65 years. The 3794 participants (73.3%) were screened for headache history according to the International Headache Society (IHS) criteria. Headache screen-positive responders, 2475 (65.2%), were interviewed by trained medical students with a structured detailed interview focused on the precipitating factors. The following precipitating factors in lifetime migraineurs and tension-type headachers have been assessed: stress, sleep disturbances, eating habits, menstrual cycle, oral contraceptives, food items, afferent stimulation, changes in weather conditions and temperature, frequent travelling and physical activity. A total of 720 lifetime migraineurs and 1319 tension-type headachers have been identified. The most common precipitants for both migraine and TTH were stress and frequent travelling. Stress (odds ratio (OR) 1.4, 95% confidence interval (CI) 1.17, 1.69) was associated with migraine, whereas physical activity (OR 0.72, 95% CI 0.59, 0.87) was related to TTH. Considering MA and MO, frequent travelling (OR 2.2, 95% CI 1.59, 2.99), food items (OR 2.2, 95% CI 1.35, 3.51) and changes in weather conditions and temperature (OR 1.75, 95% CI 1.27, 2.41) exhibited a significant positive association with MA. The present study demonstrated that precipitant-dependent attacks are frequent among both migraineurs and tensiontype headachers. Lifetime migraineurs experienced headache attacks preceded by triggering factors more frequently than tension-type headachers. MA was more frequently associated with precipitating factors than MO. We suggest that some triggering factors may contribute to the higher occurrence of precipitant-dependent headache attacks in susceptible individuals.
Abnormal 5-HT1D Receptor Function in Cluster Headache: A Neuroendocrine Study with Sumatriptan
Authors: Pinessi L , Rainero I , Valfrè W , Giudice R Lo , Ferrero M , Rivoiro C , Arvat E , Gianotti L , Del Rizzo P , Limone P
Published: May 2003

The purpose of this study was to assess the sensitivity of 5-HT1D receptors in patients with episodic cluster headache using sumatriptan as a pharmacological probe. The drug, a selective 5-HT1B/1D agonist, stimulates the secretion of growth hormone and inhibits the release of prolactin, adrenocorticotropic hormone (ACTH) and cortisol. These effects may be used to explore the function of serotonergic systems in vivo. We administered subcutaneous sumatriptan and placebo to 20 patients with cluster headache (10 in the active phase and 10 in the remission period) and to 12 controls. The sumatriptan-induced increase of growth hormone concentrations was significantly ( P < 0.05) blunted in patients with active cluster headache. Prolactin and ACTH responses to the drug were significantly ( P < 0.05) reduced in patients with cluster headache, both in the active and in the remission period. Our results suggest that cerebral serotonergic functions mediated by 5-HT1D receptors are altered in patients with episodic cluster headache.
Effect of Active Treatment is Lower When Using Placebo Control in Clinical Trials on Acute Therapy of Migraine
Authors: Eikermann A , Diener HC
Published: May 2003

Methodological aspects of study design affect therapeutic outcome. We tested the hypothesis that treatment effect of an active drug in studies on acute therapy of migraine is lower in placebo-controlled studies than in those not using a placebo-controlled design. From 522 eligible studies on acute therapy of migraine cited in Pubmed database which were published between 1964 and 1997 we randomly selected 100 studies for evaluation. We excluded five studies because they did not include a quantitative measurement of pain intensity. Of the 95 studies included in the analysis, 61 used placebo control. Response to active drug was significantly lower ( P < 0.05) in placebo-controlled studies (61% [lower and upper quartiles 44% and 75%] vs. 71% [56% and 75%]). We did not find any significant effect of quality of study design on net effect of verum. This observation should be taken into account for future planning of controlled clinical studies in acute migraine.
Physical Interventions with People with Intellectual Disabilities: Staff Training and Policy Frameworks
Authors: Murphy Glynis , Kelly‐Pike Amanda , McGill Peter , Jones Samantha , Byatt James
Published: May 2003

Background  Physical intervention or restraint with people who have intellectual disabilities is sometimes necessary, even though it is known to present dangers to both staff and service users (some service users have died as a result of restraint).

Aims  This study aims to investigate the extent to which staff in intellectual disability services were trained in the use of physical interventions or restraint. Their views of a recent policy framework on physical interventions were also sought.

Methods  There were three groups of participants: (i) group 1 included staff who had attended conferences on the Policy Framework (the conference sample); (ii) group 2 included staff from two geographical areas (the geographical sample); (iii) group 3 included staff in specialist assessment and treatment services (the SpAT sample). All participants were sent a questionnaire asking them about their training in (and use of) physical intervention methods and their opinions on the policy document.

Results  There were at least 12 different types of training recorded, including a number of varieties of Control and Restraint (C&R). By no means did all the senior staff did have training in physical intervention methods. The degree of training varied with the sample and the type of training varied with the employing organization. Most participants in group 1 were very positive about the BILD & NAS Policy Framework but few staff in groups 2 and 3 had read the document. About two‐thirds of the participants said their services had (or were developing) a written policy on physical interventions.

Conclusions  There remained a clear need for further training in physical interventions and evidence on which the effectiveness of different methods of physical interventions could be judged.