bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Growth and Endocrinal Disorders during Pubertal Maturation in Girls with Epilepsy
Authors: El‐Khayat Hamed A. , Abd El‐Basset Fatma Z. , Tomoum Hoda Y. , Tohamy Saeid M. , Zaky Amira A. , Mohamed Mervat S. , Hakky Suzan M. , Barbary Nancy S. El , Nassef Nermin M.
Published: December 2004

Summary:  Purpose: This study investigated the effect of epilepsy and/or antiepileptic drugs (AEDs) on the physical growth, pubertal development, and androgenic status of girls with epilepsy between ages 8 and 18 years.

Methods: Sixty‐six female patients with epilepsy, their mean ages 13.47 ± 3.5 years, were included. Anthropometric measurements, staging of pubertal maturation, and clinical manifestations of hyperandrogenism were assessed, as well as measurement of serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone–binding globulin (SHBG), and free androgen index (FAI). Of the included patients, 44 had transabdominal ultrasonic examination of the ovaries and fasting serum insulin levels were measured. Forty healthy age‐matched females served as a control group.

Results: Patients showed reduced mean height percentile compared with controls (z = 2.07; p = 0.04), which was negatively correlated with the duration of their epilepsy. Patients showed increased frequency of obesity, especially postpubertal girls taking valproate (VPA; 67%), who also showed higher insulin levels (t = 8.01; p = 0.0003). Patients showed increased frequency of clinical hyperandrogenemia in the different stages of puberty. High levels of testosterone and DHEAS were found in female patients with epilepsy, especially pubertal and postpubertal girls. Hyperandrogenism (clinical and/or laboratory) was most affected by the types of AEDs, with higher incidence in patients taking VPA compared with those taking enzyme‐inducing AEDs (χ2= 9.16; p = 0.01). Eighteen percent of the patients were diagnosed as having polycystic ovary syndrome (PCOS). No difference was found in the types of seizures, degree of seizure control, type of AEDs, or insulin levels between patients with and those without PCOS.

Conclusions: Longer duration of the disease has a negative impact on the stature of female patients with epilepsy. Postpubertal girls taking VPA are more liable to obesity, which is associated with increased incidence of hyperinsulinemia. Clinical and/or laboratory evidence of hyperandrogenism is seen at a high frequency in patients, especially with the use of VPA. Furthermore, female patients with epilepsy especially in the postpubertal stage of sexual maturation, have a high prevalence of PCOS, independent of the type of AED or the characteristics of the epilepsy disorder.
Sex and Estrus Cycle Differences in the Modulatory Effects of Morphine on Seizure Susceptibility in Mice
Authors: Riazi Kiarash , Honar Hooman , Homayoun Houman , Rashidi Narges , Dehghani Mehdi , Sadeghipour Hamed , Gaskari Seyed Ali , Dehpour Ahmad Reza
Published: December 2004

Summary:  Purpose: To evaluate the effects of sex and estrus cycle on biphasic anticonvulsant and proconvulsant modulation of seizure threshold by morphine.

Methods: The threshold for the clonic seizures (CST) induced by acute intravenous administration of γ‐aminobutyric acid (GABA)‐antagonist pentylenetetrazole (PTZ) was assessed in male and female mice. Estrus cycle was assessed by vaginal smears. The effect of removing circulating sex hormones was assessed by gonadectomy.

Results: At baseline, diestrus females had a higher CST compared with males and estrus females. Morphine at lower doses (0.5–3 mg/kg) had a significant anticonvulsant effect in males and estrus females compared with that in vehicle‐treated controls, whereas female mice in diestrus phase showed a relative subsensitivity to this effect. Morphine at higher doses (30 and 60 mg/kg) significantly decreased CST in males and diestrus females, with less relative effect in estrus mice. In both phases, morphine exerted stronger effects in males compared with females. Ovariectomy brought the baseline CST to the male level and resulted in significant expression of both phases of morphine effect but did not abolish the sex difference in responsiveness to morphine.

Conclusions: The biphasic modulation of seizure threshold is subject to both constitutive sex differences in sensitivity to morphine and hormonal fluctuations during the estrus cycle.
Evaluating a schools' service for children with a facial disfigurement: the views of teaching and support staff
Authors: O'DELL LINDSAY , PRIOR JESS
Published: December 2004

In this article Lindsay O'Dell and Jess Prior present the findings of a small survey, organised as a collaborative project to evaluate a schools’ service, set up in 1998 by the charity Changing Faces1 to assist pupils with facial disfigurements. Twenty schools responded, each of which had a pupil in their school, aged between 3–16 years, with a facial disfigurement. Qualitative and quantitative questions addressed schools’ expectations of the service, ratings of visits from Changing Faces, helpful/unhelpful aspects of the service and suggestions for improvements, as well as information about the child and school. The data was analysed using both quantitative data and a qualitative thematic analysis. Findings point to reasons for initial contact, and effectiveness of any intervention. Whilst many families and schools seek support in times of crisis, sometimes contact is made to try and prevent future difficulties. Professionals working in education may have much to learn from cases where the child, school and family are all coping well. Future research plans include extending this pilot survey to include the views of a wider range of schools as well as those of the children and families involved.
What is the physiological function of mast cells?
Authors: Maurer M. , Theoharides T. , Granstein R. D. , Bischoff S. C. , Bienenstock J. , Henz B. , Kovanen P. , Piliponsky A. M. , Kambe N. , Vliagoftis H. , Levi‐Schaffer F. , Metz M. , Miyachi Y. , Befus D. , Forsythe P. , Kitamura Y. , Galli S.
Published: December 2004

Abstract:  Under physiological conditions, skin mast cells preferentially localize around nerves, blood vessels and hair follicles. This observation, which dates back to Paul Ehrlich, intuitively suggests that these enigmatic, multifacetted protagonists of natural immunity are functionally relevant to many more aspects of tissue physiology than just to the generation of inflammatory and vasodilatory responses to IgE‐dependent environmental antigens. And yet, for decades, mainstream‐mast cell research has been dominated by a focus on the – undisputedly prominent and important – mast cell functions in type I immune responses and in the pathogenesis and management of allergic diseases. Certainly, it is hard to believe that the very large and rather selectively distributed number of mast cells in normal, uninflamed, non‐infected, non‐traumatized mammalian skin or mucosal tissue is simply hanging around there lazily day and night, just to wait for the odd allergen or parasite‐associated antigen to come by so the mast cell can finally swing into action. Indeed, the past decade has witnessed a renaissance of mast cell research ‘beyond allergy’, along with a more systematic exploration of the surprisingly wide range of physiological functions that mast cells may be involved in. The current debate sketches many of the exciting new horizons that have recently come into our vision during this intriguing, ongoing search.
Palliative care in a coronary care unit: a qualitative study of physicians’ and nurses’ perceptions
Authors: Nordgren Lena , Olsson Henny
Published: December 2004

Background.  Earlier research has shown that physicians and nurses are motivated to provide good palliative care, but several factors prevail that prevent the best care for dying patients. To provide good palliative care it is vital that the relationship between nurses and physicians is one based on trust, respect and sound communication. However, in settings such as a coronary care unit, disagreement sometimes occurs between different professional groups regarding care of dying patients.

Aim and objectives.  The aim of this study was to describe and understand physicians’ and nurses’ perceptions on their working relationship with one another and on palliative care in a coronary care unit setting.

Design.  Using a convenience sample, professional caregivers were interviewed at their work in a coronary care unit in Sweden.

Methods.  Data collection and analysis were done concurrently using a qualitative approach.

Results.  From the interviews, a specific pattern of concepts was identified. The concepts were associated with a dignified death, prerequisites for providing good palliative care and obstacles that prevented such care.

Conclusions.  Caregivers who work in a coronary care unit are highly motivated to provide the best possible care and to ensure a dignified death for their patients. Nevertheless, they sometimes fail in their intentions because of several obstacles that prevent good quality care from being fully realized.

Relevance to clinical practice.  To improve practice, more attention should be paid to increasing dying patients’ well‐being and participation in care, improving strategic decision‐making processes, offering support to patients and their relatives, and improving communication and interaction among caregivers working in a coronary care unit. Caregivers will be able to support patients and relatives better if there are good working relations in the work team and through better communication among the various professional caregivers.
Feeding Experience Modifies the Assessment of Ambush Sites by the Timber Rattlesnake, a Sit‐and‐Wait Predator
Authors: Clark Rulon W.
Published: December 2004

To effectively ambush prey, sit‐and‐wait predators must locate sites where profitable prey are likely to return. One means by which predators evaluate potential ambush sites is by recognizing high‐use areas through chemical cues deposited inadvertently by their prey. However, it is unknown whether ambush predators can use chemical cues associated with past prey items in the assessment of potential ambush sites. I examined selection of ambush sites by timber rattlesnakes (Crotalus horridus) exposed to trails made from chemical extracts of the integument of various prey species. I evaluated the role of feeding experience in ambush site selection by comparing the behavior of timber rattlesnakes before and after feeding experience with different sized prey items. Timber rattlesnakes are more likely to select ambush sites adjacent to chemical trails from prey with which they have had feeding experience, but only those fed relatively large prey showed an increase in responsiveness. Increased responsiveness after feeding experience was exhibited in experiments using integumentary extracts of mammals (the natural prey of timber rattlesnakes), but not in those using extracts of fish. These results indicate that ambush predators may learn to recognize chemicals on the integument of profitable food items, and use that experience when subsequently selecting ambush sites. Additionally, these findings provide evidence that size‐dependent predation by snakes may be, in some species, a result of active prey selection.
Increase in meso‐prefrontal dopaminergic activity after stimulation of CB1 receptors by cannabinoids
Authors: Diana M. , Melis M. , Gessa G. L.
Published: December 2004

The intravenous administration of the psychoactive constituent of marijuana, Δ9‐tetrahydrocannabinol (Δ9‐THC) (62.5–1000 μg/kg), and the synthetic cannabinoid agonist WIN 55212,2 (WIN) (62.5–500 μg/kg), produced a dose‐related increase in the firing rate and burst firing in the majority of antidromically identified meso‐prefrontal dopaminergic neurons.

  In a restricted number of neurons (n = 4), WIN administration did not increase firing rate but produced an increment of bursting activity. These effects of the cannabinoids were reversed by the intravenous administration of SR 141716 A, a selective cannabinoid antagonist (1 mg/kg), per se ineffective to modify the electrical activity of dopaminergic neurons.

  The results indicate that stimulation of cannabinoid CB1 receptors produces an activation of meso‐prefrontal dopaminergic transmission.

  Considering that supranormal stimulation of D1 dopamine receptors in the prefrontal cortex has been shown to impair working memory, the present results suggest that the negative effects of cannabinoids on cognitive processes might be related to the activation of dopaminergic transmission in the prefrontal cortex.
A novel form of long‐term depression in the CA1 area of the adult rat hippocampus independent of glutamate receptors activation
Authors: Berretta Nicola , Cherubini Enrico
Published: December 2004

In young rats, low frequency (1–2 Hz) stimulation of the Schaffer collaterals for 15 min induces in the CA1 area of the hippocampus a homosynaptic and N‐methyl‐d‐aspartate receptor‐dependent form of long‐term depression (LTD) of synaptic efficacy. In the adults, while a similar stimulation paradigm is able to depress previously potentiated synapses, it leads to conflicting results when applied to naive synapses. In the present experiments, different stimulation paradigms have been used to induce LTD in the CA1 area of the adult rat hippocampus in vitro. Thus, stimulation of the afferent pathway at frequencies higher than those used to produce LTD in young animals (5–10 Hz, for 15 min) reliably induced a homosynaptic form of LTD. This form of LTD was associated with a significant increase in paired‐pulse facilitation ratio and was insensitive to ionotropic (CNQX, 10 μm and CPP, 20 μm) and metabotropic (S‐MCPG, 1 mm) glutamate receptors antagonists, suggesting a presynaptic mechanism for both LTD induction and expression. In conclusion, our experiments clearly show that LTD is not a purely developmental phenomenon but is present also in mature rats, which possess the whole machinery for LTD induction and this will greatly enhance the flexibility and the storing capacity of neuronal circuits.
β‐adrenergic and fibroblast growth factor receptors induce neuronal process outgrowth through different mechanisms
Authors: Kwon John H. , Weisenhorn Daniela M. Vogt , Downen Martha , Ruan Kesan , Roback Linda , Joshi Harish , Wainer Bruce H.
Published: December 2004

The mechanisms that initiate and direct neuronal process formation remain poorly understood. We have recently described a neuronal progenitor cell line, AS583‐8.E4.22 (AS583‐8) which undergoes neurite formation in response to β2‐adrenergic and basic fibroblast growth factor (bFGF) receptor activation [Kwon, J.H et al. (1996) Eur. J. Neurosci., 8, 2042–2055]. In the present study, a comparison of these responses revealed that isoproterenol (ISO), a β‐adrenergic receptor agonist, induces multiple, highly branched processes within 30 min while bFGF induces fewer, unbranched processes within 24 h. In contrast to the ISO response, bFGF induces mitogen‐activated protein kinase activation and c‐fos expression in the cell line and results in neurite outgrowth that is dependent on new mRNA and protein synthesis. Two‐dimensional isoelectric focusing‐sodium dodecyl sulphate–polyacrylamide gel electrophoresis of cytoskeletal preparations revealed different patterns following ISO vs. bFGF exposure suggesting selective changes in protein expression and/or post‐translational modifications. Immunoblot analysis of these preparations for β‐tubulin, tyrosinated α‐tubulin and acetylated α‐tubulin also revealed different patterns following each type of treatment. Follow‐up confocal microscopy revealed that following ISO, the distribution of tyrosinated tubulin extends to the distal ends of processes whereas acetylated α‐tubulin is diminished within distal ends. This pattern has been reported to be associated with enhanced microtubule dynamics, a state in which process outgrowth is facilitated. In contrast, following bFGF treatment the distributions of tyrosinated and acetylated α‐tubulin were identical, a state associated with a diminution of microtubule dynamics. These results, a different time course of neurite formation, dependency on new gene expression and differential expression and cellular distribution of major cytoskeleton proteins suggest that neurite outgrowth induced by ISO vs. bFGF is mediated by two distinct intracellular effector mechanisms in AS583‐8 cells. In addition, studies, using the differential distribution of post‐translational modified α‐tubulins in neurites of primary neuronal cultures as marker for the two distinct processes of neurite formation suggest, that similar mechanisms are present in vivo. Therefore, the AS583‐8 cell line provides a useful model to study these signalling mechanisms that couple neurotransmitter and growth factor receptor activation to the cytoskeletal changes that mediate neurite formation.
SR141716A reduces the reinforcing properties of heroin but not heroin‐induced increases in nucleus accumbens dopamine in rats
Authors: Caillé Stéphanie , Parsons Loren H.
Published: December 2004

The present experiments tested the hypothesis that the selective CB1 receptor antagonist SR141716A alters heroin self‐administration by attenuating heroin‐induced increases in nucleus accumbens dopamine levels. SR141716A pretreatment dose‐dependently (0.3–3 mg/kg, i.p.) reduced operant heroin self‐administration by male Wistar rats under a fixed ratio schedule of reinforcement, and significantly lowered the breaking point of responding for heroin under a progressive ratio schedule of reinforcement. These observations are consistent with recent reports that CB1 receptor inactivation reduces the rewarding properties of opiates. Operant responding for water reinforcement by water‐restricted rats was unaltered by these SR141716A doses. Microdialysis tests revealed that heroin self‐administration significantly increases interstitial dopamine levels in the nucleus accumbens shell of vehicle‐pretreated control rats. However, whereas SR141716A pretreatment dose‐dependently reduced heroin self‐administration, it did not alter the heroin‐associated increase in nucleus accumbens dopamine. These findings suggest that the CB1 antagonist‐induced attenuation of heroin reward does not involve dopaminergic mechanisms in the nucleus accumbens shell.
SK channels and the varieties of slow after‐hyperpolarizations in neurons
Authors: Vogalis Fivos , Storm Johan F. , Lancaster Barrie
Published: December 2004

Action potentials and associated Ca2+ influx can be followed by slow after‐hyperpolarizations (sAHPs) caused by a voltage‐insensitive, Ca2+‐dependent K+ current. Slow AHPs are a widespread phenomenon in mammalian (including human) neurons and are present in both peripheral and central nervous systems. Although, the molecular identity of ion channels responsible for common membrane potential mechanisms has been largely determined, the nature of the channels that underlie the sAHPs in neurons, both in the brain and in the periphery, remains unresolved. This short review discusses why there is no clear molecular candidate for sAHPs.
In vivo dynamic ME‐MRI reveals differential functional responses of RA‐ and area X‐projecting neurons in the HVC of canaries exposed to conspecific song
Authors: Tindemans I. , Verhoye M. , Balthazart J. , Van der Linden A.
Published: December 2004

HVC (nidopallial area, formerly known as hyperstriatum ventrale pars caudalis), a key centre for song control in oscines, responds in a selective manner to conspecific songs as indicated by electrophysiology. However, immediate–early gene induction cannot be detected in this nucleus following song stimulation. HVC contains neurons projecting either towards the nucleus robustus archistriatalis (RA; motor pathway) or area X (anterior forebrain pathway). Both RA‐ and area X‐projecting cells show auditory responses. The present study analysed these responses separately in the two types of HVC projection neurons of canaries by a new in vivo approach using manganese as a calcium analogue which can be transported anterogradely and used as a paramagnetic contrast agent for magnetic resonance imaging (MRI). Manganese was stereotaxically injected into HVC and taken up by HVC neurons. The anterograde axonal transport of manganese from HVC to RA and area X was then followed by MRI during ≈ 8 h and changes in signal intensity in these targets were fitted to sigmoid functions. Data comparing birds exposed or not to conspecific songs revealed that song stimulation specifically affected the activity of the two types of HVC projection neurons (increase in the sigmoid slope in RA and in its maximum signal intensity in area X). Dynamic manganese‐enhanced MRI thus allows assessment of the functional state of specific neuronal populations in the song system of living canaries in a manner reminiscent of functional MRI (but with higher resolution) or of 2‐deoxyglucose autoradiography (but in living subjects).
Tangential migration of cells from the basal to the dorsal telencephalic regions in the chick
Authors: Tuorto F. , Alifragis P. , Failla V. , Parnavelas J. G. , Gulisano M.
Published: December 2004

The evolutionary relationship between telencephalic regions of the avian and mammalian brains has been a long‐standing issue in comparative neuroanatomy. Based on various criteria, a number of homologous regions have been proposed. Recent studies in mammals have shown that basal regions of the telencephalon give rise to neurons that migrate dorsally and populate the cerebral cortex. In the present study we demonstrate that, similar to mammals, neurons from a ventricular region of the palaeo‐striatal complex – the dorsal subpallial sulcus – of the chick telencephalon migrate dorsally to populate the developing pallium. Further characterization of these cells revealed that they express the neurotransmitter γ‐aminobutyric acid, but not the calcium‐binding protein calbindin. These findings provide evidence that the mouse and chick basal regions are not only homologous in terms of gene expression patterns and connectivity, but they both also contribute inhibitory interneurons to dorsal regions of the developing telencephalon.
Alike performance during nonverbal episodic learning from diversely imprinted neural networks
Authors: Grön Georg , Schul David , Bretschneider Volker , Wunderlich A. P. , Riepe Matthias W.
Published: December 2004

Performance on neuropsychological testing permits inferences to be made regarding neural networks required to solve the task. In healthy young human subjects it is common sense that differential performance in cognitive tasks results from recruitment of different neural networks and that alike performance results from recruitment of alike neural networks. It was the goal of the present study to investigate whether these assumptions are also valid in cross‐cultural studies. To address this, we used functional MRI during a nonverbal episodic memory task with repeated learning of abstract geometric patterns. Behavioural performance in this task was alike over repeated trials in native Chinese and Caucasian subjects. Given this equivalent performance, the distinct pattern of neuronal activation observed is interpreted as the outcome of different culturally imprinted processing routines. In the ‘what’ and ‘where’ framework of visuo‐spatial processing initial learning in Chinese subjects activated the dorsal stream for analysis of spatial features whereas Caucasians recruited the ventral stream for object identification. With repeated learning Chinese subjects integrated visuo‐spatial processing to object coding and vice versa. Thus, imprints of culture result in activation of distinct neural networks and mandate monitoring of both behavioural performance and neural recruitment in cross‐cultural studies of cognition.
Evidence for vesicular glutamate transporter synapses onto gonadotropin‐releasing hormone and other neurons in the rat medial preoptic area
Authors: Kiss J. , Kocsis K. , Csáki Á. , Halász B.
Published: December 2004

The medial preoptic area is a key structure in the control of reproduction. Several data suggest that excitatory amino acids are involved in the regulation of this function and the major site of this action is the medial preoptic region. Data concerning the neuromorphology of the glutamatergic innervation of the medial preoptic area are fragmentary. The present investigations were focused on: (i) the morphology of the vesicular glutamate transporter 1 (VGluT1)‐ and vesicular glutamate transporter 2 (VGluT2)‐immunoreactive nerve terminals, which are considered to be specific to presumed glutamatergic neuronal elements, in the medial preoptic area of rat; and (ii) the relationship between these glutamate transporter‐positive endings and the gonadotropin‐releasing hormone (GnRH) neurons in the region. Single‐ and double‐label immunocytochemistry was used at the light and electron microscopic level. There was a weak to moderate density of VGluT1‐ and a moderate to intense density of VGluT2‐immunoreactive elements in the medial preoptic area. Electron microscopy revealed that both VGluT1‐ and VGluT2‐immunoreactive boutons made asymmetric type synaptic contacts with unlabelled neurons. VGluT2‐labelled, but not VGluT1‐labelled, axon terminals established asymmetric synaptic contacts on GnRH‐immunostained neurons, mainly on their dendrites. The present findings are the first electron microscopic examinations on the glutamatergic innervation of the rat medial preoptic area. They provide direct neuromorphological evidence for the existence of direct glutamatergic innervation of GnRH and other neurons in the rat medial preoptic area.
Behavioural adaptations to addictive drugs in mice lacking the NMDA receptor ε1 subunit
Authors: Miyamoto Yoshiaki , Yamada Kiyofumi , Nagai Taku , Mori Hisashi , Mishina Masayoshi , Furukawa Hiroshi , Noda Yukihiro , Nabeshima Toshitaka
Published: December 2004

N‐methyl‐d‐aspartate (NMDA) receptors, a subtype of glutamate receptors (GluRs) formed by assembly of the GluRζ subunit (called NR1 in rats) with any one of four GluRε subunits (GluRε1–4; NR2A–D), play an important role in excitatory neurotransmission, synaptic plasticity and brain development. Recent pharmacological studies have also indicated a role for NMDA receptors in drug addiction. In the present study, we investigated the behavioural adaptations to addictive drugs such as phencyclidine (PCP), methamphetamine (MAP) and morphine (MOR) in mice lacking the GluRε1 subunit of the NMDA receptor. GluRε1 mutant mice exhibited a malfunction of NMDA receptors, as evidenced by the reduction of [3H]MK‐801 binding in an autoradiographic receptor binding assay. GluRε1 mutant mice showed an attenuation of acute PCP‐ and MAP‐induced hyperlocomotion. The development of sensitization by repeated treatment with PCP and MAP at a low, but not high, dose was also suppressed. The development of MOR‐induced analgesic tolerance and naloxone‐precipitated MOR withdrawal symptoms were attenuated in GluRε1 mutant mice. In the place conditioning test, PCP‐induced place aversion in naive mice and place preference in PCP‐pretreated mice, as well as MOR‐induced place preference, were diminished whereas MAP‐induced place preference was not affected in GluRε1 mutant mice. These findings provide genetic evidence that GluRε1 subunit‐containing NMDA receptors are involved in certain aspects of drug addiction.
Effect of gene transfer of GLT‐1, a glutamate transporter, into the locus coeruleus by recombinant adenoviruses on morphine physical dependence in rats
Authors: Ozawa Tohru , Nakagawa Takayuki , Sekiya Yumiko , Minami Masabumi , Satoh Masamichi
Published: December 2004

There is a body of evidence implying the involvement of the central glutamatergic system in morphine dependence. We previously reported changes in the mRNA expression of a glial glutamate transporter GLT‐1 in some brain regions of morphine‐dependent and naloxone‐precipitated withdrawal rats, and inhibition of morphine physical dependence by a glutamate transporter activator in mice. These findings support the possibility that glutamate transporters such as GLT‐1 are involved in morphine dependence. In this study, we examined the effects of gene transfer of GLT‐1 into the locus coeruleus (LC) by recombinant adenoviruses on morphine physical dependence in rats. We constructed recombinant adenoviruses that successfully delivered the GLT‐1 gene in vitro and in vivo. Local overexpression of GLT‐1 within the bilateral LC by the recombinant adenoviruses before implantation of the morphine pellet significantly inhibited various somatic signs of naloxone‐precipitated morphine withdrawal, compared with the control. These results suggest that GLT‐1 within the LC plays an inhibitory role in morphine physical dependence.
Execution and observation of bringing a fruit to the mouth affect syllable pronunciation
Authors: Gentilucci Maurizio , Santunione Paola , Roy Alice C. , Stefanini Silvia
Published: December 2004

Kinematic analysis of lip and voice spectrum analysis were used to assess the influence of both execution and observation of arm–mouth‐related actions on speech production. In experiments 1 and 2 participants brought either a cherry or an apple to their mouth and either pronounced the syllable BA (experiment 1) or emitted a nonspeech‐related vocalization (experiment 2). In the other three experiments participants observed arm actions performed by the experimenter and pronounced the syllable BA. In experiment 3, they observed the action of bringing the cherry or apple to the mouth. In experiments 4 and 5, they observed a pantomime of the same action performed by the experimenter with his own arm (experiment 4) or with a nonbiological arm (experiment 5). The results showed that the formant 2 of the vowel ‘a’ increased when participants executed the bringing‐to‐the‐mouth act with the apple or observed its execution or pantomime with the experimenter's arm (experiments 1, 3 and 4). In contrast, no modification in the vowel formants was found during a nonspeech‐related vocalization (experiment 2) and during observation of an action with a nonbiological arm (experiment 5). Finally, the opening of the lips was larger when the participant brought the apple rather than the cherry to the mouth and pronounced BA (experiment 1). Taken together, the results of the present study suggest that the execution and observation of the bringing‐to‐the‐mouth action activate a mouth articulation posture (probably due to the act of food manipulation with the mouth) which selectively influences speech production. They support the idea that the system involved in speech production shares and may derive from the neural substrate which is involved in the control of arm–mouth interactions and, in general, of arm actions.
Immunocytochemical characterization of rat brainstem neurons with vagal afferent input from the stomach challenged by acid or ammonia
Authors: Danzer Marion , Samberger Claudia , Schicho Rudolf , Lippe Irmgard Th. , Holzer Peter
Published: December 2004

Exposure of the gastric mucosa to backdiffusing acid is signalled to the brainstem via vagal afferents. This study examined whether exposure of the Sprague–Dawley rat stomach to hydrochloric acid (HCl) or ammonium hydroxide (NH4OH), a noxious chemical produced by Helicobacter pylori, activates different vagal afferent pathways as reflected by different circuitries in the medullary brainstem. Two hours after intragastric treatment with HCl or NH4OH the activation of neurons in the nucleus tractus solitarii at the rostrocaudal extension of the area postrema (NTSAP) was visualized by c‐Fos immunohistochemistry and their chemical coding characterized by double‐labelling immunohistochemistry. Exposure of the rat gastric mucosa to HCl (0.15–0.5 m) or NH4OH (0.1–0.3 m) led to a concentration‐dependent expression of c‐Fos in the NTSAP. The number and distribution of NTSAP neurons activated by 0.35 m HCl and 0.3 m NH4OH were similar; the highest number of activated neurons occurring in the medial part of the NTSAP. Some 60% of the NTSAP neurons activated by intragastric HCl and NH4OH stained for the high affinity glutamate transporter EAAC1, while some 30% contained calbindin or neuropeptide Y. Glutamate receptors of the N‐methyl‐d‐aspartate type were found on approximately 50% of the c‐Fos‐positive cells in the NTSAP, whereas tachykinin NK1, NK2 and NK3 receptors were present on 5–10% of the activated neurons. The similar number and distribution of c‐Fos‐expressing neurons within the NTSAP and their identical chemical coding indicate that exposure of the rat stomach to backdiffusing concentrations of HCl and NH4OH activates the same vagal afferent – NTSAP pathway.
Gene expression profiling reveals multiple novel intrinsic and extrinsic factors associated with axonal regeneration failure
Authors: Küry Patrick , Abankwa Daniel , Kruse Fabian , Greiner‐Petter Regine , Müller Hans Werner
Published: December 2004

In contrast to the regeneration‐competent peripheral nervous system (PNS), lesions of nerve tracts within the central nervous system (CNS) lead to chronically impaired neuronal connections. We have analysed changes in gene expression patterns occurring as a consequence of postcommissural fornix transection at a time when spontaneous axonal growth has ceased at the lesion site. This was done in order to describe both extrinsic and intrinsic determinants of regeneration failure. Using a genomic approach we have identified a number of so far undetected factors such as bamacan and semaphorin 6B, which relate to chronic axonal growth arrest and therefore are promising candidates for lesion‐induced axonal growth inhibitors. In addition, we observed that within the subiculum, where the fornix axons originate, neuronal Oct‐6 was induced and NG2 was down‐regulated, indicating that axotomized neurons as well as glial cells react at the level of gene expression to remote axotomy.
Nitric oxide‐induced cell death in developing oligodendrocytes is associated with mitochondrial dysfunction and apoptosis‐inducing factor translocation
Authors: Baud Olivier , Li Jianrong , Zhang Yumin , Neve Rachael L. , Volpe Joseph J. , Rosenberg Paul A.
Published: December 2004

Reactive nitrogen species are thought to be involved in both hypoxic‐ischemic and cytokine‐induced brain injury, including periventricular leukomalacia (PVL), the major pathological substrate of cerebral palsy in premature infants. PVL appears to be the result of perinatal inflammatory events and hypoxic‐ischemic injury to the cerebral white matter. The chronic disturbance of myelination resulting from PVL suggests that developing oligodendrocytes (OLs) are involved in its pathogenesis. We hypothesized that nitric oxide (NO) could participate in the pathogenesis of PVL through a toxic effect on developing OLs. Using primary cultures of highly enriched OLs we found that NO is toxic to developing OLs (O4+, O1–, MBP–), with an EC50value of 236 ± 125 µmof DETANOnoate. Peroxynitrite formation does not appear to be involved in NO toxicity in developing OLs, as determined by the failure of peroxynitrite scavengers as well as superoxide dismutase overexpression to prevent NO‐induced toxicity. Similarly, several pathways involving PARP, excitotoxicity, guanylyl cyclase and caspase activation were not related to NO toxicity to developing OLs. NO toxicity to OLs resulted in ATP depletion and loss of mitochondrial membrane potential (ΔΨ) in developing OLs. Apoptosis‐inducing factor (AIF) has been shown to be involved in caspase‐independent cell death, and we found that AIF translocated from mitochondria into the nucleus upon NO exposure. In conclusion, we suggest that the vulnerability of developing OLs to NO involves mitochondrial dysfunction and translocation of AIF from mitochondria to nuclei.
Synaptic release of dopamine in the subthalamic nucleus
Authors: Cragg Stephanie J. , Baufreton Jérôme , Xue Yi , Bolam J. Paul , Bevan Mark D.
Published: December 2004

The direct modulation of subthalamic nucleus (STN) neurons by dopamine (DA) neurons of the substantia nigra (SN) is controversial owing to the thick caliber and low density of DA axons in the STN. The abnormal activity of the STN in Parkinson's disease (PD), which is central to the appearance of symptoms, is therefore thought to result from the loss of DA in the striatum. We carried out three experiments in rats to explore the function of DA in the STN: (i) light and electron microscopic analysis of tyrosine hydroxylase (TH)‐, dopamine β‐hydroxylase (DβH)‐ and DA‐immunoreactive structures to determine whether DA axons form synapses; (ii) fast‐scan cyclic voltammetry (FCV) to determine whether DA axons release DA; and (iii) patch clamp recording to determine whether DA, at a concentration similar to that detected by FCV, can modulate activity and synaptic transmission/integration. TH‐ and DA‐immunoreactive axons mostly formed symmetric synapses. Because DβH‐immunoreactive axons were rare and formed asymmetric synapses, they comprised the minority of TH‐immunoreactive synapses. Voltammetry demonstrated that DA release was sufficient for the activation of receptors and abolished by blockade of voltage‐dependent Na+channels or removal of extracellular Ca2+. The lifetime and concentration of extracellular DA was increased by blockade of the DA transporter. Dopamine application depolarized STN neurons, increased their frequency of activity and reduced the impact of γ‐aminobutyric acid (GABA)‐ergic inputs. These findings suggest that SN DA neurons directly modulate the activity of STN neurons and their loss may contribute to the abnormal activity of STN neurons in PD.
Genetically based trait in a dominant tree affects ecosystem processes
Authors: Schweitzer Jennifer A. , Bailey Joseph K. , Rehill Brian J. , Martinsen Gregory D. , Hart Stephen C. , Lindroth Richard L. , Keim Paul , Whitham Thomas G.
Published: December 2004

Fundamental links between genes and ecosystem processes have remained elusive, although they have the potential to place ecosystem sciences within a genetic and evolutionary framework. Utilizing common gardens with cottonwood trees of known genotype, we found that the concentration of condensed tannins is genetically based and is the best predictor of ecosystem‐level processes. Condensed tannin inputs from foliage explained 55–65% of the variation in soil net nitrogen (N) mineralization under both field and laboratory conditions. Alternative associations with litter lignin, soil moisture or soil temperature were relatively poor predictors of litter decomposition and net N mineralization. In contrast to the paradigm that the effects of genes are too diffuse to be important at the ecosystem‐level, here we show that plant genes had strong, immediate effects on ecosystem function via a tight coupling of plant polyphenols to rates of nitrogen cycling.
Beyond biodiversity: individualistic controls of invasion in a self‐assembled community
Authors: Meiners Scott J. , Cadenasso Mary L. , Pickett Steward T. A.
Published: December 2004

Recent experimental and simulation results, and competition‐based ecological theory, predict a simple relationship between species richness and the invasibility of communities at small spatial scales – likelihood of invasion decreases with increasing richness. Here we show data from 42 continuous years of sampling old field succession that reveal quite different dynamics of plant invasion. Contrary to experimental studies, when richness was important in explaining invasion probability, it was typically positively associated with species invasion. Invasion of several species had a unimodal response to resident species richness, which appeared to be a mixture of compositional influences and a richness effect. Interestingly, invasions by native and exotic species did not fundamentally differ. Control of species invasion in this system is individualistic, caused by a variety of community‐level mechanisms rather than a single prevailing richness effect.
Variation in migration propensity among individuals maintained by landscape structure
Authors: Hanski Ilkka , Erälahti Claudia , Kankare Maaria , Ovaskainen Otso , Sirén Heli
Published: December 2004

Metapopulation dynamics lead to predictable patterns of habitat occupancy, population density and trophic structure in relation to landscape features such as habitat patch size and isolation. Comparable patterns may occur in behavioural, physiological and life‐history traits but remain little studied. In the Glanville fritillary butterfly, females in newly established populations were more mobile than females in old populations. Among females from new populations, mobility decreased with increasing connectivity (decreasing isolation), but in females from old populations mobility increased with connectivity. The [ATP]/[ADP] ratio of flight muscles following controlled activity showed the same pattern as mobility in relation to population age and connectivity, suggesting that physiological differences in flight metabolic performance contribute to the observed variation in mobility. We demonstrate with an evolutionary metapopulation model parameterised for the Glanville fritillary that increasing spatial variation in landscape structure increases variance in mobility among individuals in a metapopulation, supporting the general notion that complex landscape structure maintains life‐history variation.
Chaotropic solutes cause water stress in Pseudomonas putida
Authors: Hallsworth John E. , Heim Sabina , Timmis Kenneth N.
Published: December 2004

Low water availability is the most ubiquitous cause of stress for terrestrial plants, animals and microorganisms, and has a major impact on ecosystem function and agricultural productivity. Studies of water stress have largely focused on conditions that affect cell turgor, i.e. induce osmotic stress. We show that chaotropic solutes that do not affect turgor reduce water activity, perturb macromolecule–water interactions and thereby destabilize cellular macromolecules, inhibit growth, and are powerful mediators of water stress in a typical soil bacterium, Pseudomonas putida. Chaotropic solute‐induced water stress resulted mostly in the upregulation of proteins involved in stabilization of biological macromolecules and membrane structure. Many environmental pollutants and agricultural products are chaotropic chemicals and thus constitute a previously unrecognised but common form of biological stress in water bodies and soils.
Lipid biomolecules in silica sinters: indicators of microbial biodiversity
Authors: Pancost Richard D. , Pressley Sarah , Coleman Joanna M. , Benning Liane G. , Mountain B. W.
Published: December 2004

To explore further the diversity of the microorganisms and their relationship with geothermal sinters, we examined the lipids preserved in six sinters associated with four different hot spring (58–82°C) areas of the Taupo Volcanic Zone (TVZ), New Zealand. These sinters contain microbial remains, but the process of mineralization has rendered them largely unidentifiable. Dominant lipids include free fatty acids, 1,2‐diacylglycerophospholipids, 1,2‐di‐O‐alkylglycerols, glycerol dialkylglycerol tetraethers and 1‐O‐alkylglycerols. These confirm the presence and, in some cases, high abundances of bacteria in all six sinters and archaea in four of the six sinter samples; in addition, the presence of novel macrocyclic diethers and unusual distributions of monoethers and diethers suggest the presence of previously uncharacterized bacteria. The lipid distributions are also markedly dissimilar among the four sites; for example, novel macrocyclic diethers are restricted to the Rotokawa samples while particularly abundant monoethers occur only in the Orakei Korako sample. Thus, biomarkers can provide crucial insight into the complex community structure of thermophilic microorganisms, including both archaea and bacteria, involved with biogenic silica sinter formation.
Real Estate Transactions: Policy Considerations for Law, Technology and Globalization
Authors: MALLOY ROBIN PAUL
Published: December 2004

This essay explores a number of issues related to intellectual property and technology in real estate transactions. It examines these issues with reference to differences in property law concepts in a global context, looking at both civil law and common law ideas, for instance. The essay also discusses the integration of technology into real‐estate development projects and the infrastructure requirements for promoting real estate markets in countries with emerging and transitional economies. A key observation of the essay involves the need to think about property law questions in an integrated manner. It is no longer possible to think in a compartmentalized way regarding real property and intellectual property – in modern real estate transactions these areas are fully integrated.
Spontaneous Oscillations in Cerebral Blood Flow Velocity Give Evidence of Different Autonomic Dysfunctions in Various Types of Headache
Authors: Sliwka U. , Harscher S. , Diehl R.R. , Van Schayck R. , Niesen W.D. , Weiller C.
Published: December 2004

Objectives.—Our objectives were to determine if: (1) patients with migraine have B wave abnormalities in comparison to normal controls and patients with chronic tension headache and (2) patients with chronic tension headache have an imbalance in autonomic activity that is reflected in differences in Mayer wave activity in comparison to normal controls.

Background.—B waves and Mayer waves are spontaneous oscillations in cerebral blood flow velocity with a frequency of 0.5 to 3 or 4 to 7 cycles per minute, respectively, and can be measured by transcranial Doppler sonography. There is experimental evidence that B waves are generated by certain brain stem nuclei which modulate the lumen of the small intracerebral vessels via monoaminergic nerve endings. In contrast, Mayer waves in cerebral blood flow velocity have no central generator but mirror the Mayer waves in arterial blood pressure which represent peripheral autonomic activity. Migraine may be attributed to a neurotransmitter imbalance in brain stem nuclei. Dysfunctions of the peripheral autonomic nervous system are known in patients with chronic tension headache.

Methods.—Using bilateral transcranial Doppler monitoring of the middle cerebral artery B waves and Mayer waves were studied in 30 patients with migraine without aura, 28 subjects with tension‐type headache, and 30 normal controls. Coefficient of variation as a quantitative parameter for amplitude of waves and the mean frequency were calculated from the envelope curves of the Doppler spectra.

Results.—The coefficient of variation of B waves was higher in migrainous patients compared with patients with tension‐type headache and normal controls (P<.05), indicating an increase in activity of brain stem nuclei in migraine only. Patients with chronic tension headaches had lower values for Mayer wave activity in comparison with normal controls (P<.05), a sign of an impairment of sympathetic activity.

Conclusions.—Our data support the dysfunction of the brain stem monoaminergic/serotonergic system in migraine. In contrast, patients with chronic tension headache have an autonomic dysfunction of peripheral origin presenting as a decrease of sympathetic activity.