bluuebunny/crossref_metadata_2025 huggingface dataset:
Developmental expression patterns of four chemosensory protein genes from the Eastern spruce budworm, Chroistoneura fumiferana
Authors: Wanner K. W. , Isman M. B. , Feng Q. , Plettner E. , Theilmann D. A.
Published: June 2005

Chemosensory proteins (CSPs) are associated with insect sensory organs, including the sensillum lymph in some cases. However, they are also commonly expressed in nonsensory tissues that lack gustatory and olfactory neurones. We characterized the sex and development specific expression patterns of four CSP genes from the Eastern spruce budworm (ESB) using Northern blots. CfumAY426540.2 was detected at high levels in adult moths. Conversely, CfumAY426538 was expressed in all stages except adult moths, and was most abundant during late stages of the 6th instar. CfumAY701858 was expressed in all stages, while CfumAY426539 was detected less frequently, at specific developmental stages such as the 5th to 6th instar moult. During a natural moult, and a premature moult induced by the ecdysteroid agonist tebufenozide, CfumAY701858 and CfumAY426539 were up‐regulated, while CfumAY426538 appeared to be down‐regulated. Our results suggest that some members of the CSP gene family from the ESB may be involved in development, including moulting.
Evaluation of a mobile learning organiser for university students
Authors: Corlett Dan , Sharples Mike , Bull Susan , Chan Tony
Published: June 2005

This paper describes a 10‐month trial of a mobile learning organiser, developed for use by university students. Implemented on a wireless‐enabled Pocket PC hand‐held computer, the organiser makes use of existing mobile applications as well as tools designed specifically for students to manage their learning. The trial set out to identify the most‐used tools for such a learning device and their patterns and problems of usage. The primary uses of the organiser were communication, time‐management and access to content. No single application took precedence. The results from an analysis of questionnaire surveys and focus groups indicate that there was a demand for institutional support of mobile learning, in particular to provide course content and timetabling information. Wireless connectivity was crucial to the usefulness of the organiser. Usability issues relating to the hardware and software had considerable impact on the students' usage and satisfaction with the system.
Teachers' support with ad‐hoc collaborative networks
Authors: Cortez C. , Nussbaum M. , López X. , Rodríguez P. , Santelices R. , Rosas R. , Marianov V.
Published: June 2005

Efforts to improve the educational process must focus on those most responsible for implementing it: the teachers. It is with them in mind that we propose a face‐to‐face computer‐supported collaborative learning system that uses wirelessly networked hand‐held computers to create an environment for helping students assimilate and transfer educational content. Two applications of this system are presented in this paper. The first involves the use of the system by students, transforming classroom dynamics and enabling collaboration and interaction between the students and the teacher. In the second application, the system is used to help teachers update their knowledge of subject content and exchange methodological strategies.
Handheld tools that ‘Informate’ assessment of student learning in Science: a requirements analysis
Authors: Roschelle Jeremy , Penuel William R. , Yarnall Louise , Shechtman Nicole , Tatar Deborah
Published: June 2005

Abstract
An important challenge faced by many teachers as they involve students in science investigations is measuring (‘assessing’) students' progress. Our detailed requirements analysis in a particular school district led to the idea that what teachers need most are ways to increase the quality of the information they have about what students know and can do, not automation of typical assessment practices. We see handheld computers as promising tools for addressing this need because they can give students and teachers frequent, integral access to new ways of expressing and communicating what they know and can do. Our requirements analysis has led us to emphasize a need for handheld‐based tools that ‘informate’ science instruction by:

Being oriented to the needs of teachers in transition to inquiry‐oriented pedagogy;

expanding the range of assessment tasks through a new representational medium and communication infrastructure;

creating new roles for students in expressing what they know and can do; and

focusing both students' and teachers' attention on scientific concepts.
Mobile‐IT Education (MIT. EDU): m‐learning applications for classroom settings
Authors: Sung M. , Gips J. , Eagle N. , Madan A. , Caneel R. , DeVaul R. , Bonsen J. , Pentland A.
Published: June 2005

Abstract In this paper, we describe the Mobile‐IT Education (MIT.EDU) system, which demonstrates the potential of using a distributed mobile device architecture for rapid prototyping of wireless mobile multi‐user applications for use in classroom settings. MIT.EDU is a stable, accessible system that combines inexpensive, commodity hardware, a flexible sensor/peripheral interconnection bus, and a powerful, light‐weight distributed sensing, classification, and inter‐process communications software architecture to facilitate the development of distributed real‐time multi‐modal and context‐aware applications. We demonstrate the power and functionality of this platform by describing a number of MIT.EDU application deployments in educational settings. Initial evaluations of these experiments demonstrate the potential of using the system for real‐world interactive m‐learning applications.
Histology, Immunohistochemistry and Ultrastructure of the Equine Tubal Tonsil
Authors: Kumar P. , Timoney J. F.
Published: June 2005

The tubal tonsil of the horse surrounds the pharyngeal opening of the eustachian tube and is lined by pseudostratified columnar ciliated epithelium interspersed with areas of follicle‐associated epithelium (FAE) heavily infiltrated by lymphocytes but devoid of goblet and ciliated cells. Scanning and transmission electron microscopy revealed microvillous cells and cells with features characteristic of M cells such as reduced microvilli or depressed bare surface, more numerous mitochondria, small vesicles and lysosomes, as well as vimentin filaments and epitopes specific for GS 1‐B4 as previously seen in the nasopharyngeal tonsil. M cells were also identified in areas of respiratory epithelium not associated with lymphoid follicles and appeared to be the nasal mucosal counterparts of recently described intestinal villous M cells in the mouse. The underlying lymphoid tissue of the FAE was generally organized as solitary lymphoid follicles without germinal centres in contrast to the diffuse and large amount of organized lymphoid follicles with germinal centres that characterize the nasopharyngeal tonsil. CD8+ T and B‐lymphocytes were much fewer than in the nasopharyngeal tonsil. High endothelial venules were mainly oriented towards the parafollicular area and contained much fewer endothelial pores and vesiculo‐vacuolar organelles. Finally, scattered small clusters of mucus acini and striated muscles were other features that differentiated the tubal and nasopharyngeal tonsils.
Effects of Supplementation with Ascorbic Acid for a Period of 120 days on the Myosin‐V and NADPHd Positive Myenteric Neurons of the Ileum of Rats
Authors: Zanoni J. N. , de Freitas P. , Pereira R. V. F. , dos Santos Pereira M. A. , de Miranda Neto M. H.
Published: June 2005

We investigated the effect of ascorbic acid (AA) supplementation on the NADPH‐diaphorase (NADPHd) and myosin‐V myenteric neurons in the ileum of rats, after 4 months of treatment. Two groups were compared, i.e. controls rats (C) and AA‐treated rats (CA). Myosin‐V immunohistochemistry and NADPHd histochemistry were employed. We investigated the areas of 500 cell bodies of myosin‐V neurons and of 500 NADPHd stained neurons from all groups. The quantitative analysis was performed using an area of 8.96 mm2 from each ileum. There was an increase of 21.9% in the myosin‐V immunoreactive myenteric neurons (P > 0.05) and of 22.5% in the NADPHd in group CA when compared with C (P < 0.05). There were no significant differences when we compared the area of myosin‐V stained neurons between groups C and CA. However, we verified an area reduction of 7.5% in NADPHd neurons when comparing group C to group CA (P < 0.05).
The Distribution of External Taste Buds in Flower Fish (Pseudophoxinus antalyae)
Authors: ÇInar K. , ŞEnol N.
Published: June 2005

Purpose of this study was to determine the distribution of external taste buds of flower fish (Pseudophoxinus antalyae) on different body locations (lip, lateral, ventral and dorsal areas, dorsal–pelvic–pectoral–anal fins). In this species, it was found that the density of taste buds was greater on lip epithelium than that of lateral (between pectoral–anal, anal–caudal fins), ventral (between pelvic and anal fins) and dorsal (close to the head) locations. It was observed that the shape of taste bud changed depending upon the epithelium thickness and it was found that some of these structures protruded towards to the exterior of epithelium.
Effect of Larval Food Amount on Ovariole Development in Queens ofTrigona spinipes(Hymenoptera, Apinae)
Authors: Lisboa L. C. O. , Serrão J. E. , Cruz‐Landim C. , Campos L. A. O.
Published: June 2005

Caste determination inTrigona spinipesFabricius (Hymenoptera, Apidae, Meliponini) is trophogenic. Larvae that eat about 360 μl of food become queens, while those who consume 36 μl develop into workers. We studied the effect of larval nutrition on the number and length of ovarioles and on ovarian development in fifth instar larvae, white eyed, pink eyed and black‐eyed pupae as well as newly emerged adults. All larvae have four ovarioles per ovary, while in queen pupae this number ranged from 8 to 15. Cyst formation, the cell death and other characteristics of ovary morphogenesis were the same regardless of the quantity of food consumed. These results are discussed in relation to caste differentiation in other bees.
Light and Electron Microscopic Study of the Thoracic Respiratory Air Sacs of the Fowl
Authors: Bezuidenhout A. J.
Published: June 2005

There are conflicting reports in the existing literature on the nature of the epithelial lining and the content of the supporting connective tissue of the respiratory air sacs of birds. The present study describes the light and electron microscopic structure of the thoracic air sacs of the fowl. A simple squamous epithelium lined the greater part of the thoracic air sacs. The squamous cells characteristically contained vesicles filled with lamellar or myelinoid material. Localized areas of cuboidal to columnar ciliated epithelium were randomly distributed and often associated with underlying blood vessels. Isolated ciliated cells first appeared on squamous or low cuboidal cells and increased in frequency as the cells became taller. Occasional basal and goblet cells were seen between the ciliated columnar cells. A fibrous connective tissue stroma supported the epithelium. Fine elastic fibres were particularly prevalent immediately below the epithelium. Isolated smooth muscle myocytes were present in the connective tissue stroma. A sheet of smooth muscle extended some distance into the membrane from the attachment of the latter to the body wall. Numerous small blood vessels, lymphatics and occasional nerve bundles were observed in the stroma.
Histology, Immunohistochemistry and Ultrastructure of the Equine Palatine Tonsil
Authors: Kumar P. , Timoney J. F.
Published: June 2005

The palatine tonsils of five young horses formed 10–12 cm elongated follicular structures extending from the root of the tongue on either side to the base of the epiglottis and lateral to the glossoepiglottic fold. The stratified squamous non‐keratinized epithelium of the outer surface was modified into crypts as reticular epithelium by heavy infiltration of lymphoid cells from underlying lymphoid follicles. In places, lymphoid tissue reaching almost to the surface and with only one to two cell layers intact was identified as the lymphoepithelium. Langerhans cells with Birbeck granules were interspersed between epithelial cells. Lymphoid tissue organized in lymphoid follicles constituted the parenchyma of the palatine tonsil. CD4‐positive cells were more numerous and CD8‐positive lymphocytes less numerous compared with their distribution in the lingual tonsil. B cells and macrophages were also more numerous than in the lingual tonsil and lectins showed a different pattern of attachment. M cells were not observed. High endothelial venules with well‐developed vesiculo‐vacuolar organelle had structural evidence of transendothelial and interendothelial migration of lymphocytes. Striated muscles as seen in the deeper lamina propria mucosae of the lingual tonsil were absent. The immunohistological and ultrastructural characteristics of the equine palatine tonsil are similar to those of humans but differ from those of the lingual tonsil and are consistent with a role as an effector and inductor immunological organ.
On the Relationship between Herbaceous Cover and Vigilance Activity of Degus (Octodon degus)
Authors: Ebensperger Luis A. , Hurtado María J.
Published: June 2005

A number of studies demonstrate that plant cover provides prey animals with refuges to decrease vulnerability to predators. However, others suggest plant cover to visually obstruct detection of predators or conspecifics. We suggest these seemingly conflicting results can, to some extent, be resolved if overhead vs. lateral cover are distinguished. We recorded seasonal variation in vigilance activity of a natural population of degus (Octodon degus), a diurnal, semi‐subterranean and social rodent from central Chile. We used these data to determine whether cover provided by herbaceous vegetation is mostly obstructive. The height of herbaceous vegetation in the habitat of degus varied seasonally, and the ability of degus (estimated from human observers) to detect potential predators decreased when herbaceous vegetation was high. This effect was more important for degus using quadruped postures and when dealing with terrestrial simulated predators. Accordingly, degus adjusted the quality rather than the quantity of their vigilance activity: male and female degus allocated similarly more time to bipedal vigilance when the height of herbs was high. Such increase in bipedal vigilance seemed to occur at the expense of quadruped vigilance instead of foraging time. Collectively, these results support the hypothesis that cover of herbaceous vegetation is mostly obstructive to degus when active above ground, a finding that contrasts with previous evidence supporting that shrub cover provides refuges against predators. The differential effects of shrubs and herbs on degu vigilance are likely linked to differences in the costs and benefits associated with each cover type. For degus, shrubs may provide more overhead (protective) than lateral (obstructive) cover.
Kinetics and metabolism of zearalenone in young female pigs
Authors: Dänicke S. , Swiech E. , Buraczewska L. , Ueberschär K.‐H.
Published: June 2005

The fate of a single bolus of the Fusarium mycotoxin zearalenone (ZON) given intravenously to pigs was followed up. Pigs were equipped with duodenal re‐entrant cannulas, post‐valvular T‐shape cannulas and with a urinary bladder balloon catheter. The animals were divided into three groups. Pigs of the control group were injected with ZON (Co), and pigs of the second group were also injected with ZON but their duodenal digesta was quantitatively exchanged for 12 h with corresponding pigs of the third group, not injected with ZON. Therefore, the second group had a disrupted entero‐hepatic cycling of ZON (DEHC) and the third one had an induced entero‐hepatic cycling of ZON (IEHC). The kinetic profile of ZON and its metabolites in plasma and their flow with urine, duodenal and ileal digesta and with faeces was examined over the next 72 h after the bolus was given. Eleven days later, pigs were slaughtered for collection of bile, urine and liver to analyse ZON residues. In all specimens examined, α‐zearalenol (ZOL) was detected as the only metabolite of ZON. Kinetic evaluation of the plasma data revealed that the terminal elimination half‐life of ZON was reduced from 2.63 h in pigs of Co‐group to 1.1 h when EHC of ZON was disrupted for 12 h (DEHC‐group). The maximum ZON concentration in plasma of pigs with the IEHC was found at 2.73 h after the bolus was given to their counterparts. The percentage of the α‐ZOL‐ and ZON‐area under the curves (AUC) estimated for the IEHC‐group amounted to approximately 18% of the corresponding AUC of the Co‐group which would suggest that a substantial proportion of both substances are re‐cycled via entero‐hepatic re‐circulation. Cumulative recovery of ZON and α‐ZOL, expressed as percentage of the ZON‐bolus was characterized by a saturation kinetics in urine and duodenal digesta, and after 72 h, the respective values for Co‐, DEH‐, and IEHC‐groups were 70%, 55% and 12%; and 35%, 22% and 11%. Faecal excretion started to increase steeply after 48 h and still continued to increase after 72 h when the cumulative excretion was 6%, 3% and 2% for Co‐, DEHC‐ and IEHC‐groups respectively. Fourteen days after the bolus injection, ZON and α‐ZOL concentrations in bile, liver and urine were lower than the detection limits of the applied method. The results would suggest that within this period of time a massive single bolus of ZON is nearly completely eliminated from the body.
Threonine and tryptophan ratios fed to nursery pigs*
Authors: Guzik A. C. , Pettitt M. J. , Beltranena E. , Southern L. L. , Kerr B. J.
Published: June 2005

The optimal ratio of tryptophan (Trp):lysine (Lys) relative to the ratio of threonine (Thr):Lys was studied in 288 crossbred (Cambrough 15 × Canabrid) nursery pigs from 7.1 to 15.6 kg BW. Treatments were arranged in a 3 × 3 factorial with three calculated ratios of true digestible Thr:Lys (0.55, 0.60, or 0.65) in combination with three Trp:Lys ratios (0.145, 0.170, or 0.195). Treatments were replicated with eight pens of four pigs each. The experiment lasted 28 day with Phase II (222.6 g CP and 11.9 g true digestible Lys/kg diet, initially 24 day of age and 7.1 kg BW) and Phase III (196.2 g CP and 10.1 kg true digestible Lys/kg diet, initially 38 day of age and 9.8 kg BW) diets each fed for 14 day. Threonine by Trp interactions were observed for average daily gain during each period, and for daily feed intake during Phase III and overall. Generally, Trp addition linearly increased gain and feed intake at a Thr:Lys ratio of 0.60 and 0.65 but not at a Thr:Lys ratio of 0.55. Gain:feed was increased linearly with increasing levels of Trp during both periods. There were no main effects of Thr in either time period or overall. Overall, optimal performance was obtained in pigs fed the true digestible Trp:Lys ratio of 0.195 at Thr:Lys ratios 0.60 or 0.65. These results indicate that Trp:Lys ratios above 0.195 may be needed to maximize performance in diets containing wheat and barley.
Ultrasonic Assessment of Puerperal Uterine Involution in Balady Goats
Authors: Ababneh M. M. , Degefa T.
Published: June 2005

Twenty‐six postpartum Balady goats (primiparous, n = 13; pluriparous, n = 13) were used in this study. One animal of each group was slaughtered on postpartum days 1, 2, 4, 7, 10, 13, 19 and 25; in addition, three control nulliparous goats were slaughtered, and the genital tracts collected. Progress of uterine involution was monitored by repeated ultrasonographic measurements in live animals (primiparous n = 6; pluriparous n = 6) and measurement of the outer circumference of the uterine horns of slaughtered animals (primiparous n = 8; pluriparous n = 8). A consistent and progressive decrease in ultrasonographic and outer circumference measurements was found, although faster during the first 7 days postpartum than between days 7 and 19 postpartum. Uterine involution, assessed by the upper limit of the measurements in the nulliparous goats, followed a quadratic pattern and was completed by day 19 postpartum. Ultrasonographically, two elliptical–circular echogenic areas separated by an anechoic line of the stratum vascularis were depicted. Regressing caruncles and fluid in uterine lumen were recognized during the first week postpartum. Further analysis revealed a highly positive correlation between the outer circumference and ultrasonographic measurements. In conclusion, uterine involution in Balady goats was completed by day 19 postpartum and was unrelated to parity. The close association between ultrasound findings and macroscopic involution indicated that ultrasonography can dependably be used to monitor uterine involution under field conditions and can be a suitable alternative to animal slaughter for the study of uterine involution.
Post‐pneumonectomy empyema: Current management strategies
Authors: Ng Calvin S. H. , Wan Song , Lee Tak Wai , Wan Innes Y. P. , Arifi Ahmed A. , Yim Anthony P. C.
Published: June 2005

Post‐pneumonectomy empyema is an uncommon but potentially life‐threatening complication. It has a strong association with bronchopleural fistula, which acts as a continued source of infection into the thoracic cavity. Numerous risk factors have been identified and strategies formulated to minimize its occurrence. When bronchopleural fistula occurs, its treatment depends on several factors including extent of dehiscence, degree of pleural contamination and general condition of the patient. Early diagnosis and assessment with appropriate investigations, and aggressive therapeutic strategies are paramount in controlling sepsis, facilitating closure of fistula, and sterilization of the closed pleural space. Recent success with repeat debridement has made routine space obliteration not mandatory in management. The development of minimal‐access interventions including video‐assisted thoracic surgery, endoscopic application of tissue glue and stenting may be additional tools to complement conventional surgery in post‐pneumonectomy empyema management.
Radial nerve morbidity in radial artery free flaps: Harvest of cephalic vein versus venae comitantes
Authors: Grinsell Damien , Theile David
Published: June 2005

Background:  The purpose of the present paper was to determine the radial nerve morbidity associated with harvest of different venous conduits in the radial artery free flap.

Methods:  Retrospective study comparing subjective and objective symptoms of radial nerve morbidity in 51 consecutive free flaps over a 3‐year period.

Results:  Damage to the radial nerve occurred in 9% (1/11) of patients in the cephalic vein group versus 18% (4/28) in the venae comitante group.

Conclusions:  Raising the cephalic vein for venous drainage in the radial artery free flap doubles the incidence of radial nerve morbidity.
POSSUM scoring for laparoscopic cholecystectomy in the elderly
Authors: Tambyraja Andrew L. , Kumar Sudhir , Nixon Stephen J.
Published: June 2005

Background: Physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) scoring is a validated scoring system in the audit of surgical outcomes; however, evaluation of this system has mostly been applied to open surgical techniques. The present study examines the validity of POSSUM in predicting morbidity and mortality in patients undergoing laparoscopic cholecystectomy (LC) with the recognized risk factor for postoperative mortality of advanced age.

Methods: All patients aged 80 years or over undergoing LC in one surgical unit between January 1993 and December 1999 were identified from the surgical operations database of the hospital. Case‐note review was used to collate data in terms of clinical and operative factors as described in POSSUM. Observed/POSSUM estimated (O/E) ratio of morbidity and 30‐day mortality were calculated.

Results: Laparoscopic cholecystectomy was performed in 76 patients aged 80 years or over during the study period. Of these patients, case notes for 70 patients (92%) were available for review. Median (range) age was 83 years (80−93 years) and median (range) American Society of Anesthesiologists score was 2 (2−4). Twenty‐six (34%) of 70 patients underwent cholecystectomy during an acute admission. The mean physiology severity score was 23 and operative severity score, 8. A significant postoperative morbidity was observed in 15 (22%) of 70 patients. There was no 30‐day mortality. Using exponential analysis, POSSUM predicted morbidity in 15 patients and mortality in seven patients. Thus, O/E ratios for morbidity and mortality were 1 and 0, respectively.

Conclusion: POSSUM scoring performs well in predicting morbidity, but overpredicts mortality, after LC in patients aged over 80 years. An assessment of its application to other laparoscopic procedures merits evaluation.
Sodium phenylbutyrate prolongs survival and regulates expression of anti‐apoptotic genes in transgenic amyotrophic lateral sclerosis mice
Authors: Ryu Hoon , Smith Karen , Camelo Sandra I. , Carreras Isabel , Lee Junghee , Iglesias Antonio H. , Dangond Fernando , Cormier Kerry A. , Cudkowicz Merit E. , H. Brown Robert , Ferrante Robert J.
Published: June 2005

Multiple molecular defects trigger cell death in amyotrophic lateral sclerosis (ALS). Among these, altered transcriptional activity may perturb many cellular functions, leading to a cascade of secondary pathological effects. We showed that pharmacological treatment, using the histone deacetylase inhibitor sodium phenylbutyrate, significantly extended survival and improved both the clinical and neuropathological phenotypes in G93A transgenic ALS mice. Phenylbutyrate administration ameliorated histone hypoacetylation observed in G93A mice and induced expression of nuclear factor‐κB (NF‐κB) p50, the phosphorylated inhibitory subunit of NF‐κB (pIκB) and beta cell lymphoma 2 (bcl‐2), but reduced cytochrome c and caspase expression. Curcumin, an NF‐κB inhibitor, and mutation of the NF‐κB responsive element in the bcl‐2 promoter, blocked butyrate‐induced bcl‐2 promoter activity. We provide evidence that the pharmacological induction of NF‐κB‐dependent transcription and bcl‐2 gene expression is neuroprotective in ALS mice by inhibiting programmed cell death. Phenylbutyrate acts to phosphorylate IκB, translocating NF‐κB p50 to the nucleus, or to directly acetylate NF‐κB p50. NF‐κB p50 transactivates bcl‐2 gene expression. Up‐regulated bcl‐2 blocks cytochrome c release and subsequent caspase activation, slowing motor neuron death. These transcriptional and post‐translational pathways ultimately promote motor neuron survival and ameliorate disease progression in ALS mice. Phenylbutyrate may therefore provide a novel therapeutic approach for the treatment of patients with ALS.
Presynaptic inhibition of transmitter release from rat sympathetic neurons by bradykinin
Authors: Edelbauer Hannah , Lechner Stefan G. , Mayer Martina , Scholze Thomas , Boehm Stefan
Published: June 2005

Bradykinin is known to stimulate neurons in rat sympathetic ganglia and to enhance transmitter release from their axons by interfering with the autoinhibitory feedback, actions that involve protein kinase C. Here, bradykinin caused a transient increase in the release of previously incorporated [3H] noradrenaline from primary cultures of dissociated rat sympathetic neurons. When this effect was abolished by tetrodotoxin, bradykinin caused an inhibition of tritium overflow triggered by depolarizing K+ concentrations. This inhibition was additive to that caused by the α2‐adrenergic agonist UK 14304, desensitized within 12 min, was insensitive to pertussis toxin, and was enhanced when protein kinase C was inactivated. The effect was half maximal at 4 nm and antagonized competitively by the B2 receptor antagonist Hoe 140. The cyclooxygenase inhibitor indomethacin and the angiotensin converting enzyme inhibitor captopril did not alter the inhibition by bradykinin. The M‐type K+ channel opener retigabine attenuated the secretagogue action of bradykinin, but left its inhibitory action unaltered. In whole‐cell patch‐clamp recordings, bradykinin reduced voltage‐activated Ca2+ currents in a pertussis toxin‐insensitive manner, and this action was additive to the inhibition by UK 14304. These results demonstrate that bradykinin inhibits noradrenaline release from rat sympathetic neurons via presynaptic B2 receptors. This effect does not involve cyclooxygenase products, M‐type K+ channels, or protein kinase C, but rather an inhibition of voltage‐gated Ca2+ channels.
Deafness‐related plasticity in the inferior colliculus: gene expression profiling following removal of peripheral activity
Authors: Holt Avril Genene , Asako Mikiya , Lomax Catherine A. , MacDonald James W. , Tong Ling , Lomax Margaret I. , Altschuler Richard A.
Published: June 2005

The inferior colliculus (IC) is a major center of integration in the ascending as well as descending auditory pathways, where both excitatory and inhibitory amino acid neurotransmitters play a key role. When normal input to the auditory system is decreased, the balance between excitation and inhibition in the IC is disturbed. We examined global changes in gene expression in the rat IC 3 and 21 days following bilateral deafening, using Affymetrix GeneChip arrays and focused our analysis on changes in expression of neurotransmission‐related genes. Over 1400 probe sets in the Affymetrix Rat Genome U34A Array were identified as genes that were differentially expressed. These genes encoded proteins previously reported to change as a consequence of deafness, such as calbindin, as well as proteins not previously reported to be modulated by deafness, such as clathrin. A subset of 19 differentially expressed genes was further examined using quantitative RT–PCR at 3, 21 and 90 days following deafness. These included several GABA, glycine, glutamate receptor and neuropeptide‐related genes. Expression of genes for GABA‐A receptor subunits β2, β3, and γ2, plus ionotropic glutamate receptor subunits AMPA 2, AMPA 3, and kainate 2, increased at all three times. Expression of glycine receptor α1 initially declined and then later increased, while α2 increased sharply at 21 days. Glycine receptor α3 increased between 3 and 21 days, but decreased at 90 days. Of the neuropeptide‐related genes tested with qRT–PCR, tyrosine hydroxylase decreased approximately 50% at all times tested. Serotonin receptor 2C increased at 3, 21, and 90 days. The 5B serotonin receptor decreased at 3 and 21 days and returned to normal by 90 days. Of the genes tested with qRT–PCR, only glycine receptor α2 and serotonin receptor 5B returned to normal levels of expression at 90 days. Changes in GABA receptor β3, GABA receptor γ2, glutamate receptor 2/3, enkephalin, and tyrosine hydroxylase were further confirmed using immunocytochemistry.
Mapping the areas sensitive to long‐term endotoxin tolerance in the rat brain: a c‐fos mRNA study
Authors: Vallès Astrid , Martí Octavi , Armario Antonio
Published: June 2005

We have recently found that a single endotoxin administration to rats reduced the hypothalamic–pituitary–adrenal response to another endotoxin administration 4 weeks later, which may be an example of the well‐known phenomenon of endotoxin tolerance. However, the time elapsed between the two doses of endotoxin was long enough to consider the above results as an example of late tolerance, whose mechanisms are poorly characterized. To know if the brain plays a role in this phenomenon and to characterize the putative areas involved, we compared the c‐fos mRNA response after a final dose of endotoxin in animals given vehicle or endotoxin 4 weeks before. Endotoxin caused a widespread induction of c‐fos mRNA in the brain, similar to that previously reported by other laboratories. Whereas most of the brain areas were not sensitive to the previous experience with endotoxin, a few showed a reduced response in endotoxin‐pretreated rats: the parvocellular and magnocellular regions of the paraventricular hypothalamic nucleus, the central amygdala, the lateral division of the bed nucleus and the locus coeruleus. We hypothesize that late tolerance to endotoxin may involve plastic changes in the brain, likely to be located in the central amygdala. The reduced activation of the central amygdala in rats previously treated with endotoxin may, in turn, reduce the activation of other brain areas, including the hypothalamic paraventicular nucleus.
Occurrence and possible biological role of the endocannabinoid system in the sea squirt Ciona intestinalis
Authors: Matias Isabel , McPartland John M. , Di Marzo Vincenzo
Published: June 2005

A cannabinoid receptor orthologue (CiCBR) has been described in the sea squirt Ciona intestinalis. Here we report that CiCBR mRNA expression is highest in cerebral ganglion, branchial pharynx, heart and testis of C. intestinalis, and that this organism also contains cannabinoid receptor ligands and some of the enzymes for ligand biosynthesis and inactivation. Using liquid chromatography–mass spectrometry, the endocannabinoid anandamide was found in all tissues analysed (0.063–5.423 pmol/mg of lipid extract), with the highest concentrations being found in brain and heart. The endocannabinoid 2‐arachidonoylglycerol (2‐AG) was fivefold more abundant than anandamide, and was most abundant in stomach and intestine and least abundant in heart and ovaries (2.677–50.607 pmol/mg of lipid extract). Using phylogenomic analysis, we identified orthologues of several endocannabinoid synthesizing and degrading enzymes. In particular, we identified and partly sequenced a fatty acid amide hydrolase (FAAH) orthologue, showing 44% identity with human FAAH and containing nearly all the amino acids necessary for a functional FAAH enzyme. Ciona intestinalis also contained specific binding sites for cannabinoid receptor ligands, and an amidase enzyme with pH‐dependency and subcellular/tissue distribution similar to mammalian FAAHs. Finally, a typical C. intestinalis behavioural response, siphon reopening after closure induced by mechanical stimulation, was inhibited by the cannabinoid receptor agonist HU‐210, and this effect was significantly attenuated by mammalian cannabinoid receptor antagonists.
GalR1, but not GalR2 or GalR3, levels are regulated by galanin signaling in the locus coeruleus through a cyclic AMP‐dependent mechanism
Authors: Hawes Jessica J. , Brunzell Darlene H. , Wynick David , Zachariou Venetia , Picciotto Marina R.
Published: June 2005

The galanin receptors GalR1, GalR2 and GalR3 are widely expressed throughout the mouse brain and are enriched in catecholaminergic nuclei. Here, we show that GalR1 protein levels are regulated by neuronal activity and changes in cAMP levels. GalR1, but not GalR2 or GalR3, is specifically up‐regulated in the LC‐like Cath.a cell line in a cAMP‐dependent manner. GalR1 protein and mRNA levels are also up‐regulated in the LC of galanin knockout mice, whereas GalR2 and GalR3 are not. Lack of galanin‐maintained cAMP tone in the galanin knockout mouse appears to result in a loss of negative feedback resulting in increased levels of CREB phosphorylation and increased GalR1 expression. These findings suggest that changes in levels of GalR1 may play an important role in modulating signaling events and neuroplasticity underlying physiological functions of the LC.
Nuclear/cytoplasmic shuttling of the transcription factor FoxO1 is regulated by neurotrophic factors
Authors: Gan Lixia , Zheng Wenhua , Chabot Jean‐Guy , Unterman Terry G. , Quirion Remi
Published: June 2005

FoxO1, a member of the FoxO subfamily of forkhead transcription factors, is an important target for insulin and growth factor signaling in the regulation of metabolism, cell cycle and proliferation, and survival in peripheral tissues. However, its role in the central nervous system is mostly unknown. In this study, we examined the effect of neurotrophic factors on nuclear/cytoplasmic shuttling of FoxO1. We showed that insulin‐like growth factor‐1 (IGF‐1) and nerve growth factor (NGF) potently induced the nuclear exclusion of FoxO1‐green fluorescent protein (GFP) while neurotrophin (NT)‐3 and NT‐4 were much weaker and brain‐derived neurotrophic factor (BDNF) failed to induce FoxO1 translocation in PC12 cells. FoxO1 translocation was inhibited by LY294002, a well‐established PI3K/Akt kinase inhibitor. Moreover, FoxO1 was phosphorylated at Thr24 and Ser256 residues by the above neurotrophic factors, with the exception of BDNF. Triple mutant FoxO1, in which three Akt/PKB phosphorylation sites (Thr24, Ser256 and Ser319) were mutated to alanine, resulted in the complete nuclear targeting of the expressed FoxO1‐GFP fusion protein in the presence of the above neurotrophic factors in both PC12 cells and cultured hippocampal and cortical neurons. Taken together, these findings demonstrate that neurotrophic factors are able to regulate nuclear/cytoplasmic shuttling of FoxO1 via the PI3K/Akt pathway in neuronal cells.
Molecular and neurochemical evidence for the biosynthesis of dehydroepiandrosterone in the adult rat spinal cord
Authors: Kibaly Cherkaouia , Patte‐Mensah Christine , Mensah‐Nyagan Ayikoe G.
Published: June 2005

Various studies have indicated that exogenous dehydroepiandrosterone (DHEA) modulates several mechanisms in the CNS of rodents. As adult rodent glands do not secrete significant amounts of DHEA, its role as endogenous modulator of the CNS remains possible only if DHEA is produced by nerve cells. Therefore, the last decade has been marked by diverse unsuccessful investigations aiming to demonstrate the activity of cytochrome P450c17 (P450c17), the key DHEA‐synthesizing enzyme, in adult rodent CNS. Here, we combined molecular, anatomical, cellular and neurochemical approaches to provide the first demonstration of the existence of P450c17 and bioactivity in adult rat spinal cord (SC). Real‐time RT‐PCR revealed P450c17 gene expression in all SC segments. Western blot analyses allowed identification of a specific P450c17 protein in the SC and immunohistochemical studies localized P450c17 in neurones and glial cells. Pulse‐chase experiments combined with HPLC and radioactive steroid detection showed that SC slices converted [3H]pregnenolone into [3H]DHEA, a conversion markedly reduced by ketoconazole, a P450c17 inhibitor. Kinetics studies revealed accumulation of [3H]DHEA newly synthesized by SC slices in the incubation medium as its amount declined slowly. This first cellular mapping of an active P450c17 in adult rodent SC suggests that endogenous DHEA synthesized in spinal neural networks may control various spinally‐mediated activities.
HIV‐Tat protein induces P‐glycoprotein expression in brain microvascular endothelial cells
Authors: Hayashi Kentaro , Pu Hong , Tian Jing , Andras Ibolya E. , Lee Yong Woo , Hennig Bernhard , Toborek Michal
Published: June 2005

Among the different factors which can contribute to CNS alterations associated with HIV infection, Tat protein is considered to play a critical role. Evidence indicates that Tat can contribute to brain vascular pathology through induction of endothelial cell activation. In the present study, we hypothesized that Tat can affect expression of P‐glycoprotein (P‐gp) in brain microvascular endothelial cells (BMEC). P‐gp is an ATP‐dependent cellular efflux transporter which is involved in the removal of specific non‐polar molecules, including drugs used for highly active antiretroviral therapy (HAART). Treatment of BMEC with Tat1−72 resulted in P‐gp overexpression both at mRNA and protein levels. These alterations were confirmed in vivo in brain vessels of mice injected with Tat1−72 into the hippocampus. Furthermore, pre‐treatment of BMEC with SN50, a specific NF‐κB inhibitor, protected against Tat1−72‐stimulated expression of mdr1a gene, i.e. the gene which encodes for P‐gp in rodents. Tat1−72‐mediated changes in P‐gp expression were correlated with increased rhodamine 123 efflux, indicating the up‐regulation of transporter functions of P‐gp. These results suggest that Tat‐induced overexpression of P‐gp in brain microvessels may have significant implications for the development of resistance to HAART and may be a contributing factor for low efficacy of HAART in the CNS.
Dopaminergic neurons in rat ventral midbrain cultures undergo selective apoptosis and form inclusions, but do not up‐regulate iHSP70, following proteasomal inhibition
Authors: Rideout Hardy J. , Lang‐Rollin Isabelle C. J. , Savalle Magali , Stefanis Leonidas
Published: June 2005

Dysfunction of the ubiquitin‐dependent protein degradation system, either at the level of the proteasome itself, or at the level of ubiquitination, may play a role in the pathogenesis of Parkinson's disease (PD) and other related neurodegenerative disorders. We have employed a cellular model of this dysfunction in which lactacystin or epoxomicin, selective pharmacological inhibitors of the proteasome, are applied to primary cultures of embryonic rat ventral midbrain. Proteasomal inhibition with either agent led to apoptotic death specifically within phenotypically defined tyrosine hydroxylase (TH)‐positive dopaminergic neurons, with little or no apoptotic death induced in GABAergic neurons. Inhibition of the proteasome also led to the formation of ubiquitin and α‐synuclein‐positive cytoplasmic inclusions in TH‐positive and TH‐negative neurons. Inclusions were observed in viable as well as apoptotic neurons, and required new or ongoing transcription. Tyrosine hydroxylase immunolabeling was often present within the inclusions. Such mislocalization may lead to dysfunction of dopamine biosynthesis. Interestingly, dopaminergic neurons, unlike other neurons within these cultures or cultured cortical neurons, failed to induce the chaperone Hsp70 in response to proteasomal inhibition. This failure may explain in part the increased sensitivity of these neurons to proteasomal inhibitors.
Chronic nicotine differentially affects the function of nicotinic receptor subtypes regulating neurotransmitter release
Authors: Grilli Massimo , Parodi Monica , Raiteri Maurizio , Marchi Mario
Published: June 2005

It is known that nicotine can activate several subtypes of release‐regulating presynaptic nicotinic receptors (nAChRs) including those situated on central noradrenergic, dopaminergic, cholinergic and glutamatergic axon terminals. The objective of this study was to investigate the effects of chronic administration of (–)nicotine on the function of the above autoreceptors and heteroreceptors using rat superfused synaptosomes. In hippocampal synaptosomes prelabelled with [3H]noradrenaline (NA) the nicotine‐evoked overflow of [3H]NA was higher in rats treated with nicotine for 10 days (via osmotic mini‐pumps) than in vehicle‐treated rats. In striatal synaptosomes, prelabelled with [3H]dopamine (DA), chronic nicotine did not modify the releasing effect of nicotine. No significant change was observed in experiments with synaptosomes from nucleus accumbens prelabelled with [3H]DA. Exposure of hippocampal synaptosomes prelabelled with [3H]choline to nicotine elicited release of [3H]acetylcholine; this effect was almost abolished in synaptosomes from animals administered nicotine for 10 days, suggesting down‐regulation of nicotinic autoreceptors. In hippocampal synaptosomes prelabelled with [3H]d‐aspartate, the releasing effect of epibatidine following chronic nicotine treatment did not differ from that in controls. The K+‐evoked exocytotic release of the neurotransmitters tested was not modified by long‐term nicotine administration. The results show that chronic nicotine differentially affects the function of release‐regulating nAChR subtypes.
Lactate induces tumour necrosis factor‐α, interleukin‐6 and interleukin‐1β release in microglial‐ and astroglial‐enriched primary cultures
Authors: Andersson Anna K. , Rönnbäck Lars , Hansson Elisabeth
Published: June 2005

Hyperammonaemia has deleterious effects on the CNS in patients with liver dysfunction. Cellular mechanisms underlying the effects of hyperammonaemia are largely unknown, although astrocytes have been the main target of interest. This study investigated how treatment with NH4Cl and lactate, which increase in the brain as a consequence of hyperammonaemia, affects cells in primary rat cultures enriched in either astrocytes or microglia. Morphological changes were studied over time using light microscopy. Release of the proinflammatory cytokines tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐6 and IL‐1β was measured using ELISA. NH4Cl was found to induce vacuole formation in both culture systems. Lactate treatment altered astrocytic appearance, resulting in increased space between individual cells. Microglia adopted a round morphology with either NH4Cl or lactate treatment. Lactate, but not NH4Cl, induced release of TNF‐α and IL‐6 in both astroglial‐ and microglial‐enriched cultures, while IL‐1β was released only in microglial cultures. Cytokine release was higher in the microglial‐ than in the astroglial‐enriched cultures. Additionally, the astroglial‐enriched cultures containing approximately 10% microglial cells released more cytokines than cultures containing about 5% microglial cells. Taken together, our data suggest that most TNF‐α, IL‐6 and IL‐1β release comes from microglia. Thus, microglia could play an important role in the pathological process of hyperammonaemia.
Metabotropic glutamate receptors and neuroadaptation to antidepressants: imipramine‐induced down‐regulation of β‐adrenergic receptors in mice treated with metabotropic glutamate 2/3 receptor ligands
Authors: Matrisciano F. , Scaccianoce S. , Del Bianco P. , Panaccione I. , Canudas A. M. , Battaglia G. , Riozzi B. , Ngomba R. T. , Molinaro G. , Tatarelli R. , Melchiorri D. , Nicoletti F.
Published: June 2005

Antidepressant drugs have a clinical latency that correlates with the development of neuroadaptive changes, including down‐regulation of β‐adrenergic receptors in different brain regions. The identification of drugs that shorten this latency will have a great impact on the treatment of major depressive disorders. We report that the time required for the antidepressant imipramine to reduce the expression of β‐adrenergic receptors in the hippocampus is reduced by a co‐administration with centrally active ligands of type 2/3 metabotropic glutamate (mGlu2/3) receptors. Daily treatment of mice with imipramine alone (10 mg/kg, i.p.) reduced the expression of β‐adrenergic receptors in the hippocampus after 21 days, but not at shorter times, as assessed by western blot analysis of β1‐adrenergic receptors and by the amount of specifically bound [3H]CGP‐12177, a selective β‐adrenergic receptor ligand. Down‐regulation of β‐adrenergic receptors occurred at shorter times (i.e. after 14 days) when imipramine was combined with low doses (0.5 mg/kg, i.p.) of the selective mGlu2/3 receptor agonist LY379268, or with the preferential mGlu2/3 receptor antagonist LY341495 (1 mg/kg, i.p.). Higher doses of LY379268 (2 mg/kg, i.p.) were inactive. This intriguing finding suggests that neuroadaptation to imipramine – at least as assessed by changes in the expression of β1‐adrenergic receptors – is influenced by drugs that interact with mGlu2/3 receptors and stimulates further research aimed at establishing whether any of these drugs can shorten the clinical latency of classical antidepressants.