bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of a double blind, placebo controlled, artificial food colourings and benzoate preservative challenge on hyperactivity in a general population sample of preschool children
Authors: Reading Richard
Published: December 2004

.
 
Bateman B,
Warner JO,
Hutchinson E,
Dean T,
Rowlandson P,
Gant C,
Grundy J,
Fitzgerald C &
Stevenson J.
 
(
2004
)
Archives of Disease in Childhood
,
89
,
506
–
511
.

Aims

To determine whether artificial food colourings and a preservative in the diet of 3 years old children in the general population influence hyperactive behaviour.

Methods

A sample of 1873 children were screened in their fourth year for the presence of hyperactivity at baseline (HA), of whom 1246 had skin prick tests to identify atopy (AT). Children were selected to form the following groups: HA/AT, not‐HA/AT, HA/not‐AT and not‐HA/not‐AT (n = 277). After baseline assessment, children were subjected to a diet eliminating artificial colourings and benzoate preservatives for 1 week; in the subsequent 3 weeks within subject double blind crossover study they received, in random order, periods of dietary challenge with a drink containing artificial colourings (20 mg daily) and sodium benzoate (45 mg daily) (active period), or a placebo mixture, supplementary to their diet. Behaviour was assessed by a tester blind to dietary status and by parents’ ratings.

Results

There were significant reductions in hyperactive behaviour during the withdrawal phase. Furthermore, there were significantly greater increases in hyperactive behaviour during the active than the placebo period based on parental reports. These effects were not influenced by the presence or absence of hyperactivity, nor by the presence or absence of atopy. There were no significant differences detected based on objective testing in the clinic.

Conclusions

There is a general adverse effect of artificial food colouring and benzoate preservatives on the behaviour of 3 years old children which is detectable by parents but not by a simple clinic assessment. Subgroups are not made more vulnerable to this effect by their prior levels of hyperactivity or by atopy.
Growth hormone receptor expression and function in pituitary adenomas
Authors: Clausen Lene R. , Kristiansen Mikkel T. , Rasmussen Lars M. , Billestrup Nils , Blaabjerg Ole , Ledet Thomas , Jørgensen Jens O. L.
Published: December 2004

objective and design  Hypopituitarism, in particular GH deficiency, is prevalent in patients with clinically nonfunctioning pituitary adenomas (NFPAs) both before and after surgery. The factors regulating the growth of pituitary adenomas in general and residual tumour tissue in particular are not fully characterized, and the effect of GH and IGF‐I on human pituitary cell proliferation has not previously been reported. In NFPA tissue from 14 patients we evaluated GH receptor (GHR) expression and signal transduction, and the effect of GH and IGF‐I exposure on cell proliferation and hormone secretion in vitro.

measurements  Tissue samples from 14 NFPAs were investigated. Expression of GHR in tissue samples was assessed by reverse transcription polymerase chain reaction (RT‐PCR). Six tumours were immunostained with a GHR antibody. In the cell cultures, STAT5 (signal transducer and activator of transcription 5) phosphorylation was measured by Western blot analysis as an index of GHR signalling; cell proliferation was evaluated by [H3]‐thymidine incorporation and glycoprotein hormone production analysed by radioimmunoassay (RIA).

results  All adenomas investigated expressed the GHR, but there was no detection of STAT5 phosphorylation. Overall, GH and IGF‐I administration did not significantly stimulate cell proliferation in vitro, although some individual adenomas exhibited a proliferative response to various extents. GH also did not significantly influence glycoprotein hormone secretion in vitro.

conclusion  GH receptors are expressed in human pituitary adenoma cells but their functional role is uncertain. GH and IGF‐I do not consistently influence the proliferation of cultured pituitary adenoma cells.
Species identification of Chilean Artemia populations based on mitochondrial DNA RFLP analysis
Authors: Gajardo Gonzalo , Crespo Julio , Triantafyllidis Alexander , Tzika Athanasia , Baxevanis Athanasios D. , Kappas Ilias , Abatzopoulos Theodore J.
Published: December 2004

Aim  Two species of the brine shrimp, namely Artemia franciscana Kellogg and A. persimilis Piccinelli and Prosdocimi, inhabit Chile. Most studies so far have shown that A. franciscana is the most widely distributed species in Chile, with A. persimilis present only in Chilean Patagonia. In general, there is good agreement between morphological and genetic comparisons of Chilean populations with respect to species discrimination. However, a number of results indicate an overlap with some populations tending to diverge from A. franciscana and/or resembling A. persimilis. Prior to the mid 90's the use of DNA markers in Artemia was rather limited, despite their successful application in numerous other species. In this study, we investigate whether the conclusions drawn from traditional comparative tools are congruent with the pattern of genetic divergence depicted by DNA analysis at the mitochondrial level.

Location  Eight sites in Chile and two reference samples of A. franciscana and A. persimilis from San Francisco Bay (USA) and Buenos Aires (Argentina), respectively.

Methods  Restriction fragment length polymorphism (RFLP) analysis of a 535 bp segment of the mitochondrial 16S rRNA gene with nine restriction enzymes in 240 individuals.

Results  No haplotype was shared between the two species. Five restriction enzymes produced species‐specific patterns, enabling the unambiguous assignment of populations to species. Very high (100%) bootstrap values supported the clustering of haplotypes in two groups corresponding to the two species. The two species were clearly differentiated with average sequence divergence of 12.3%. High genetic differentiation was also found among con‐specific populations of A. franciscana with an FST estimate of 91%.

Main conclusions  The mitochondrial DNA (mtDNA) results of this study show a broadly similar pattern to those of previous allozyme and nuclear DNA analyses, with the two New World species appearing as highly divergent. The presence of A. persimilis in southern Chile (Chilean Patagonia) was confirmed. Hence, a species previously regarded as geographically restricted mainly to Argentina, appears to have expanded its range. Populations of A. franciscana appear highly structured with a level of inter‐population genetic differentiation much higher for mtDNA than previously reported with allozymes. Clustering of these populations does not follow a clear geographic pattern. The identification of population‐specific genetic markers for A. persimilis and A. franciscana will help to tackle further aspects of the speciation patterns of these species.
Effect of residual endogenous insulin secretion on the abnormal oxytocin response to hypoglycaemia in insulin‐dependent diabetes
Authors: VOLPI R. , CHIODERA P. , CAPRETTI L. , CAFFARRI G. , GIULIANI N. , CAIAZZA A. , COIRO V.
Published: December 2004

. Volpi R, Chiodera P, Capretti L, Caffarri G, Giuliani N, Caiazza A, Coiro V (University of Parma, Hospital of Codogno, Hospital of Guastalla, Hospital of Fidenza, Italy). Effect of residual endogenous insulin secretion on the abnormal oxytocin response to hypoglycaemia in insulin‐dependent diabetics. J Intern Med 1998; 244: 43–8.

Objectives

Arginine‐vasopressin (AVP) and oxytocin (OT) secretions are abnormally stimulated by hypoglycaemia in patients with IDDM. Since previous studies showed that AVP secretion is influenced by the persistence of residual endogenous insulin secretion, we wondered whether this factor also regulates OT secretion.

Design

Case‐control study: the OT response to insulin‐induced hypoglycaemia was measured in normal and diabetic patients with or without residual endogenous insulin secretion.

Subjects

Ten normal male subjects, 10 C‐peptide positive (CpP) and 11 C‐peptide negative (CpN) male diabetic patients.

Tests

Preliminary studies: plasma C‐peptide levels were measured after intravenous administration of 1 mg glucagon.

Insulin tolerance test (ITT): diabetics were studied after optimization of their metabolic status by 3 days of treatment with constant subcutaneous insulin infusion. CpP and CpN diabetics and normal controls were tested with an intravenous administration of 0.15 IU per kg body weight insulin. Blood samples for OT assay were taken just before the rapid injection of insulin (time 0) and at time 15, 30, 45 and 60 min.

Results

The basal concentrations of OT were similar in all groups. Insulin induced a similar hypoglycaemic nadir in all groups at 30 min, even though diabetic groups showed a delayed recovery in blood glucose levels. The glycaemic pattern was similar in all diabetic patients. Hypoglycaemia‐induced OT rise was significantly higher in the two diabetic groups than in the normal group. However, CpN patients showed significantly higher OT increments than CpP subjects.

Conclusions

These data indicate that a residual endogenous insulin secretion exerts a partial protective action against the hypothalamic‐pituitary disorder affecting the OT secretory system in IDDM.
Do Reforms in Transition Economies Affect Foreign Bank Entry?
Authors: Lensink Robert , de Haan Jakob
Published: December 2004

Using a newly developed database for eight transition economies, this paper examines whether reforms and political freedom are important for foreign bank entry. We provide evidence that foreign bank entry positively responds to reform measures. We also find some support for the importance of political freedom. Our estimates suggest that economic reform affects foreign bank entry by enhancing the efficiency of the financial sector and by stimulating domestic investments.
Purification and mass spectroscopic analysis of human CB2 cannabinoid receptor expressed in the baculovirus system
Authors: Filppula S. , Yaddanapudi S. , Mercier R. , Xu W. , Pavlopoulos S. , Makriyannis A.
Published: December 2004

Abstract:  The cannabinergic system is present in a variety of organs and tissues that perform a wide range of essential physiologic functions making it an inherently important therapeutic target for drug discovery. In order to augment our knowledge regarding the interactions between cannabinoid receptors (CBs) and their ligands, efficient and effective tools are essential for robust expression and purification of these membrane‐bound proteins. In this report, we describe a suitable method for purification of the human cannabinoid receptor 2 (CB2) to a qualitative and quantitative level sufficient for mass spectral analysis. We utilized a baculovirus expression system, incorporating several epitope tags to facilitate purification and to ameliorate the effect the tags have on CB2 expression and function. Expressed protein encoded by a carboxy (C)‐terminal His‐tagged CB2 construct displayed a Bmax value of 9.3 pmol/mg with a KD of 7.30 nm using [3H]CP–55940, a standard cannabinoid radioligand, and was selected for subsequent purification experiments. Western blot analysis of purified membrane protein yielded several forms of CB2, the most abundant being a 41 kDa peptide. A second protein species was observed with an apparent molecular weight of 46 kDa representing a glycosylated form of CB2. In addition, a CB2 homodimer was also identified. The purified receptor was subjected to mass spectroscopic analysis to confirm its identity and purity. Mass spectra corresponding to the intracellular, extracellular and transmembrane domains were obtained. These experiments exemplify the importance of high‐level expression systems when developing membrane‐bound protein purification strategies. This work will aid in the identification of receptor–ligand binding sites, the characterization of molecular features involved in receptor activation, and the elucidation of the CB2 receptor tertiary structure.
Rejection of Conspecific Eggs in Chaffinches: The Effect of Age and Clutch Characteristics
Authors: Stokke Bård G. , Rudolfsen Geir , Moksnes Arne , Røskaft Eivin
Published: December 2004

Previous experimental studies have found that the majority of chaffinches,Fringilla coelebs, are able to reject both non‐mimetic and mimetic cuckoo eggs and also non‐mimetic conspecific eggs. However, interestingly the frequency of rejecters of moderately mimetic conspecific eggs has been found to be only approx. 50%. We examined the possibility that acceptors of moderately mimetic conspecific eggs are first time breeders, because these individuals may lack the experience needed to reject eggs that deviate only slightly from their own eggs. Older individuals, with good knowledge of their own egg appearance, should therefore reject such eggs. We also examined the possibility that acceptors of moderately mimetic eggs have a higher intraclutch variation in egg appearance, which makes it more difficult to recognize such eggs when compared with rejecters. We obtained no support for any age‐specific pattern in rejection behaviour. Furthermore, there was no relationship between age and intraclutch variation, or intraclutch variation and rejection behaviour. As there is no evidence of intraspecific brood parasitism in this species, the rejection of any foreign eggs is most probably an adaptation to past cuckoo,Cuculus canorus, parasitism. Acceptance of good and moderately mimetic conspecific eggs is probably due to cognitive limitations, because evolution of a more fine‐tuned recognition ability is unnecessary in the absence of intraspecific brood parasitism.
Both ETA and ETB receptors are involved in mitogen‐activated protein kinase activation and DNA synthesis of astrocytes: study using ETB receptor‐deficient rats (aganglionosis rats)
Authors: Sasaki Yukio , Hori Seiji , Oda Kyoko , Okada Toshikazu , Takimoto Misato
Published: December 2004

Endothelin (ET) is known to be a potent mitogen in astrocytes. However, the contribution and signalling pathway of ETA and/or ETB receptor to the proliferation of astrocytes remain unclear. We investigated ET‐induced DNA synthesis in astrocytes using ETB receptor‐deficient mutant rats (aganglionosis rats: sl/sl). Western blotting with anti‐ET receptor subtype‐specific antibodies and Scatchard analysis of binding revealed that ETB receptor expression in astrocytes depended on gene dosage (+/+: sl/+: sl/sl = 2: 1: 0), whereas ETA receptor expression was unchanged among the three genotypes. ET‐1 (10 nm) stimulated [3H]thymidine incorporation and mitogen‐activated protein kinase (MAP kinase) activity not only in +/+ via both ETA and ETB receptors, but also in sl/sl astrocytes via ETA receptor with about half the extent of those observed in +/+ astrocytes. Treatment with pertussis toxin (PTX) suppressed the ET‐1‐induced increases in the incorporation and MAP kinase activity in +/+, but not sl/sl astrocytes, indicating that the ETB receptor‐, but not the ETA receptor‐, mediated pathway to DNA synthesis involves PTX‐sensitive G proteins, e.g. Gi and/or Go (Gi/o). In +/+ astrocytes, ET‐1 (1 nm) stimulated cAMP accumulation, and the ETB receptor‐selective agonist IRL 1620 (1 nm) suppressed 10 μm forskolin‐induced cAMP accumulation, suggesting Gs coupling to the ETA receptor and Gi/o coupling to the ETB receptor. On the other hand, ET‐1 did not increase cAMP accumulation in sl/sl astrocytes, although ET‐1 (1 nm) suppressed the forskolin‐induced response, suggesting Gi/o coupling to the ETA receptor. Our results suggest the possibility that the selectivity of G protein for ETA receptor is changed from Gs to Gi/o in ETB receptor‐deficient astrocytes.
Blockade of M2‐like muscarinic receptors enhances long‐term potentiation at corticostriatal synapses
Authors: Calabresi Paolo , Centonze Diego , Gubellini Paolo , Pisani Antonio , Bernardi Giorgio
Published: December 2004

Acetylcholine (ACh) exerts a crucial role in learning and memory. The striatum contains the highest concentration of this transmitter in the brain. This structure expresses two different forms of synaptic plasticity, long‐term depression (LTD) and long‐term potentiation (LTP), which might contribute to the storage of motor skills and some cognitive processes. We have investigated the role of M2‐like muscarinic receptors in striatal LTP by utilizing intracellular recordings in vitro from a rat corticostriatal slice preparation. Methoctramine (250 nm), an antagonist of M2‐like muscarinic receptors, enhanced striatal LTP induced in the absence of external magnesium (Mg2+) by high‐frequency stimulation (HFS) of corticostriatal fibres. Methoctramine did not affect the amplitude of excitatory postsynaptic potentials (EPSPs) when bath applied either before or after the conditioning tetanus suggesting that a critical increase of ACh concentrations is produced only during HFS. Methoctramine per se failed to enhance the NMDA‐mediated EPSPs recorded in the absence of external Mg2+ and in the presence of 10 μm CNQX. Methoctramine antagonized the presynaptic inhibitory action of neostigmine, an inhibitor of ACh‐esterase, and oxotremorine, an agonist of M2‐like muscarinic receptors. These data indicate that the activation of M2‐like muscarinic receptors exerts a negative influence on striatal LTP, probably by reducing the release of glutamate from corticostriatal fibres and they suggest a complex modulatory effect of ACh in striatal synaptic plasticity.
Cortical inhibitory circuits in eye‐movement generation
Authors: Schiller Peter H. , Tehovnik Edward J.
Published: December 2004

The role inhibitory circuits play in target selection with saccadic eye movements was examined in area V1, the frontal eye fields (FEF) and the lateral intraparietal sulcus (LIP) of the Rhesus Macaque monkey by making local infusions of the GABA agonist muscimol and antagonist bicuculline. In V1, both agents greatly interfered with target selection and visual discrimination of stimuli placed into the receptive field of the affected neurons. In the FEF, bicuculline facilitated target selection without affecting visual discrimination and generated many spontaneous saccades. Muscimol in the FEF interfered with saccadic eye‐movement generation. In the LIP, bicuculline was ineffective and muscimol had only a small effect. These findings suggest that in the FEF GABAergic inhibitory circuits play a central role in eye‐movement generation whereas in V1 these circuits are essential for visual analysis. Inhibitory circuits in the LIP do not appear to play a central role in target selection and in visual discrimination.
Reduced expression of a novel µ‐opioid receptor (MOR) subtype MOR‐1B in CXBK mice: Implications of MOR‐1B in the expression of MOR‐mediated responses
Authors: Narita Minoru , Imai Satoshi , Ozaki Satoru , Suzuki Masami , Narita Michiko , Suzuki Tsutomu
Published: December 2004

A novel µ‐opioid receptor (MOR) subtype, named MOR‐1B, derived from alternatively spliced variants of MOR gene, has been isolated from the rat brain. Here we found for the first time that CXBK recombinant‐inbred mice display a significant reduction in the expression of MOR‐1B mRNA in the brain as compared to that in their progenitor C57BL/6 mice. In contrast, the expression level of MOR‐1 mRNA in the brain of CXBK mice was similar to that found in C57BL/6 mice. Furthermore, relatively lower levels of MOR‐1B immunoreactivity were detected in the periaqueductal grey matter (PAG) of CXBK mice than that observed in C57BL/6 mice. To investigate further the possible changes in MOR function to activate G‐proteins under the condition of a reduced MOR‐1B expression, the guanosine‐5′‐o‐(3‐[35S]thio)triphosphate ([35S]GTPγS) binding assay was performed. We found that the increased level of [35S]GTPγS bindings to whole brain membranes induced by a selective MOR agonist endomorphin‐1 was significantly decreased in CXBK mice, indicating that CXBK strain can be classified as MOR‐1B‐knockdown mice. We next investigated whether intracerebroventricular (i.c.v.) pretreatment with an antisence oligodeoxynucleotide against exon 5 of MOR gene (MOR‐1B) could affect the endomorphin‐1‐induced supraspinal antinociception. The i.c.v. pretreatment with antisence oligodeoxynucleotide against MOR‐1B produced a significant reduction in the i.c.v.‐administered endomorphin‐1‐induced antinociceptive effect. The present data provide first evidence that a lack of MOR‐1B expression may, at least in part, contribute to the reduced sensitivity to MOR agonists in CXBK mice, and MOR‐1B may play a potential role in the MOR‐mediated supraspinal antinociception.
Transcranial magnetic stimulation of the human frontal eye field facilitates visual awareness
Authors: Grosbras Marie‐Hélène , Paus Tomáš
Published: December 2004

What are the brain mechanisms allowing a stimulus to enter our awareness? Some theories suggest that this process engages resources overlapping with those required for action control, but experimental support for these ideas is still required. Here, we investigated whether the human frontal eye field (FEF), an area known to control eye movements, is involved in visual awareness. Volunteers participated in a backward masking task in which they were able to detect a target in a small proportion of trials. We observed that a single pulse of transcranial magnetic stimulation applied over the FEF shortly before the target's onset facilitated visual sensitivity; subjects were able to detect an otherwise subliminal object. These results show that modulating the neuronal activity of the FEF can enhance visual detection, thereby yielding new insights into the neural basis of visual awareness.
Glutamate receptor binding in the frontal cortex and dorsal striatum of aged rats with impaired attentional set‐shifting
Authors: Nicolle Michelle M. , Baxter Mark G.
Published: December 2004

Aged Long–Evans rats exhibit deficits in attentional set shifting, an aspect of executive function, relative to adult rats. Impairments in set shifting and spatial learning are uncorrelated in aged rats, indicating a possible dissociation of the effects of ageing in prefrontal versus hippocampal systems. Ionotropic glutamate receptor binding was assessed using an in vitro autoradiography method in young and aged rats. The rats had been tested on a set‐shifting task that measured attentional set shifts and reversal learning, as well as in a spatial learning task in the Morris water maze. [3H]Kainate, [3H]AMPA and NMDA‐displaceable [3H]glutamate receptor binding were quantified in orbital cortex, cingulate cortex, medial frontal cortex, dorsolateral and dorsomedial striatum. Age‐related decreases in [3H]kainate binding were apparent in all regions measured. Similarly, NMDA‐displaceable [3H]glutamate binding was decreased in the aged rats in all the regions measured except for the medial frontal area where no age effects were observed. [3H]AMPA receptor binding was preserved with age in all the regions measured. Lower levels of [3H]kainate binding in the cingulate cortex were significantly correlated with poorer set‐shifting performance, whereas higher levels of NMDA binding in the dorsomedial striatum were correlated with poorer set‐shifting performance. There were no significant correlations between the levels of ionotropic glutamate receptors and performance in the reversal task or spatial learning in the Morris water maze. These results indicate that age‐related behavioural deficits in attentional set shifting are selectively associated with neurobiological alterations in the cingulate cortex and dorsomedial striatum.
First‐ and second‐order stimulus length selectivity in New World monkey striate cortex
Authors: Bourne J. A. , Lui L. , Tweedale R. , Rosa M. G. P.
Published: December 2004

Motion is a powerful cue for figure‐ground segregation, allowing the recognition of shapes even if the luminance and texture characteristics of the stimulus and background are matched. In order to investigate the neural processes underlying early stages of the cue‐invariant processing of form, we compared the responses of neurons in the striate cortex (V1) of anaesthetized marmosets to two types of moving stimuli: bars defined by differences in luminance, and bars defined solely by the coherent motion of random patterns that matched the texture and temporal modulation of the background. A population of form‐cue‐invariant (FCI) neurons was identified, which demonstrated similar tuning to the length of contours defined by first‐ and second‐order cues. FCI neurons were relatively common in the supragranular layers (where they corresponded to 28% of the recorded units), but were absent from layer 4. Most had complex receptive fields, which were significantly larger than those of other V1 neurons. The majority of FCI neurons demonstrated end‐inhibition in response to long first‐ and second‐order bars, and were strongly direction selective. Thus, even at the level of V1 there are cells whose variations in response level appear to be determined by the shape and motion of the entire second‐order object, rather than by its parts (i.e. the individual textural components). These results are compatible with the existence of an output channel from V1 to the ventral stream of extrastriate areas, which already encodes the basic building blocks of the image in an invariant manner.
Substance P and enkephalinergic synapses onto neurokinin‐1 receptor‐immunoreactive neurons in the pre‐Bötzinger complex of rats
Authors: Liu Ying‐Ying , Wong‐Riley Margaret T. T. , Liu Jin‐Ping , Wei Xiao‐Yan , Jia Yi , Liu Hui‐Ling , Fujiyama Fumino , Ju Gong
Published: December 2004

Our previous studies have demonstrated that neurokinin‐1 receptor (NK1R)‐immunoreactive (ir) neurons in the pre‐Bötzinger Complex (pre‐BötC), the hypothesized kernel of respiratory rhythmogenesis, receive both glutamatergic excitatory and GABAergic or glycinergic inhibitory inputs. Neuromodulators, such as substance P (SP) and opioids, play important roles in normal respiratory activity and respiratory disorders. The identification of the relationship between neurotransmitters and NK1R‐ir neurons at the cellular level is essential for understanding the synaptic interaction within the pre‐BötC network. Using immunofluorescence and immunogold‐silver staining, we wished to exploit SP and enkephalin (ENK) immunoreactivity and their relationships with glutamate, GABA, glycine, or NK1R in the pre‐BötC in adult Sprague–Dawley rats. The pre‐BötC contained a substantial amount of SP‐ir and ENK‐ir boutons. They were largely colocalized with glutamate and much less so with GABA. Glycine immunoreactivity was rarely found in either SP‐ir or ENK‐ir boutons. A number of SP‐ir boutons were ENK‐ir as well. Synapses were commonly found between SP‐ir or ENK‐ir terminals and NK1R‐ir neurons in the pre‐BötC. Most of them were asymmetric. Symmetric synapses made up 10% of all synapses examined between SP‐ir boutons and NK1R‐ir neurons, and 19% of ENK/NK1R synapses. Colocalization of SP and/or ENK with glutamate in boutons in the pre‐BötC implies the combined synaptic release of excitatory amino acid and neuropeptides, which may exert combined post‐synaptic effects onto NK1R‐ir neurons and contribute to respiratory activity.
Expression of vesicular glutamate transporters, VGLUT1 and VGLUT2, in cholinergic spinal motoneurons
Authors: Herzog E. , Landry M. , Buhler E. , Bouali‐Benazzouz R. , Legay C. , Henderson C. E. , Nagy F. , Dreyfus P. , Giros B. , El Mestikawy S.
Published: December 2004

Mammalian spinal motoneurons are cholinergic neurons that have long been suspected to use also glutamate as a neurotransmitter. We report that VGLUT1 and VGLUT2, two subtypes of vesicular glutamate transporters, are expressed in rat spinal motoneurons. Both proteins are present in somato‐dendritic compartments as well as in axon terminals in primary cultures of immunopurified motoneurons and sections of spinal cord from adult rat. However, VGLUT1 and VGLUT2 are not found at neuromuscular junctions of skeletal muscles. After intracellular injection of biocytin in motoneurons, VGLUT2 is observed in anterogradely labelled terminals contacting Renshaw inhibitory interneurons. These VGLUT2‐ and VGLUT1‐positive terminals do not express VAChT, the vesicular acetylcholine transporter. Overall, our study establishes for the first time that (i) mammalian spinal motoneurons express vesicular glutamate transporters, (ii) these motoneurons have the potential to release glutamate (in addition to acetylcholine) at terminals contacting Renshaw cells, and finally (iii) the VGLUTs are not present at neuromuscular synapses of skeletal muscles.
Central sprouting of uninjured small fiber afferents in the adult rat spinal cord following spinal nerve ligation
Authors: Hu Jian , Mata Marina , Hao Shuanglin , Zhang Gui , Fink David J.
Published: December 2004

Partial nerve injury results in chronic pain that is difficult to treat effectively. To investigate the anatomic basis of this phenomenon we used wheat germ agglutinin–horseradish peroxidase (WGA‐HRP) to label the central projections of uninjured small fibers (Aδ and C) in a well‐established model of neuropathic pain created by selective spinal nerve ligation in the adult. We found extensive sprouting of uninjured WGA‐HRP‐labeled afferents into the central termination field in lamina II of dorsal horn normally occupied by L5 afferents whose peripheral axons had been ligated distal to the dorsal root ganglion. The formation of new projections by uninjured fibers into a functionally but not anatomically deafferented field in the adult may play a role in the development of chronic pain.
Time course for the reappearance of vibrissal motor representation following botulinum toxin injection into the vibrissal pad of the adult rat
Authors: Franchi G. , Veronesi C.
Published: December 2004

The present study investigates the time course and pattern of movement representation recovery in the motor cortex during the recovery after a peripheral paralysis. To this end a transitory flaccid paralysis of the vibrissae muscle was induced in adult rats that underwent two unilateral injections of 8 U of botulinum toxin (BTX) into a vibrissal pad, at a duration of 12 days from one another. The compound muscle action potential (MAP) of the vibrissae muscle began to reappear 4 weeks after the first BTX injection. Intracortical microstimulation (ICMS) was used to map rat motor cortices 4, 5, 6, 7 and 8 weeks after the first BTX injection. Findings demonstrated that: (i) contralateral vibrissae movement reappears in the medial part of its normal cortical territory when the MAP is almost 10% of the control value; in the remaining part, ICMS elicits eye, ipsilateral vibrissae, neck and forelimb movements; (ii) the contralateral vibrissae movement reappears in sites where ipsilateral vibrissae and/or neck movement are co‐represented; (iii) as MAP recovers, the vibrissae representation expands until it recovers the 90.8% of its territory after 7 weeks, when the MAP was almost 43.4% of the control value; (iv) from 4 to 7 weeks, the ICMS‐evoked contralateral vibrissae movement shows a significantly higher electrical threshold vs. the control group; (v) recovery of the baseline excitability uniformly involves the vibrissae representation 1 week later, after its cortical territory has recovered 93.1% of the control value and the MAP has returned to 78.8% of the baseline value.
Sampling Hubbell's neutral theory of biodiversity
Authors: Alonso David , McKane Alan J.
Published: December 2004

In the context of neutral theories of community ecology, a novel genealogy‐based framework has recently furnished an analytic extension of Ewens’ sampling multivariate abundance distribution, which also applies to a random sample from a local community. Here, instead of taking a multivariate approach, we further develop the sampling theory of Hubbell's neutral spatially implicit theory and derive simple abundance distributions for a random sample both from a local community and a metacommunity. Our result is given in terms of the average number of species with a given abundance in any randomly extracted sample. Contrary to what has been widely assumed, a random sample from a metacommunity is not fully described by the Fisher log‐series, but by a new distribution. This new sample distribution matches the log‐series expectation at high biodiversity values (θ > 1) but clearly departs from it for species‐poor metacommunities (θ < 1). Our theoretical framework should be helpful in the better assessment of diversity and testing of the neutral theory by using abundance data.
Invasion in space and time: non‐native species richness and relative abundance respond to interannual variation in productivity and diversity
Authors: Cleland Elsa E. , Smith Melinda D. , Andelman Sandy J. , Bowles Christy , Carney Karen M. , Claire Horner‐Devine M. , Drake John M. , Emery Sarah M. , Gramling Joel M. , Vandermast David B.
Published: December 2004

Ecologists have long sought to understand the relationships among species diversity, community productivity and invasion by non‐native species. Here, four long‐term observational datasets were analyzed using repeated measures statistics to determine how plant species richness and community resource capture (i.e. productivity) influenced invasion. Multiple factors influenced the results, including the metric used to quantify invasion, interannual variation and spatial scale. Native richness was positively correlated with non‐native richness, but was usually negatively correlated with non‐native abundance, and these patterns were stronger at the larger spatial scale. Logistic regressions indicated that the probability of invasion was reduced both within and following years with high productivity, except at the desert grassland site where high productivity was associated with increased invasion. Our analysis suggests that while non‐natives were most likely to establish in species rich communities, their success was diminished by high resource capture by the resident community.
Conservation of the response regulator gene gacA in Pseudomonas species
Authors: De Souza J. T. , Mazzola M. , Raaijmakers J. M.
Published: December 2004

The response regulator gene gacA influences the production of several secondary metabolites in both pathogenic and beneficial Pseudomonas spp. In this study, we developed primers and a probe for the gacA gene of Pseudomonas species and sequenced a 425 bp fragment of gacA from ten Pseudomonas strains isolated from different plant‐associated environments. Polymerase chain reaction analysis and Southern hybridization showed that gacA is highly conserved within the genus Pseudomonas: multiple strains of different Pseudomonas species all responded positively to the probe, whereas no response was obtained from 18 other strains representing 14 species that belong to eight different genera of Gram‐negative bacteria other than Pseudomonas. Furthermore, from a total of approximately 550 indigenous bacterial isolates obtained from the rhizosphere of wheat, all isolates that hybridized with the gacA probe were classified as Pseudomonas spp. by group‐specific primers. Isolates that did not respond with the gacA probe and primers were identified as bacterial genera other than Pseudomonas, including Stenotrophomonas, Cryseomonas and Comamonas spp. These results indicate that gacA can be used as a complementary genetic marker for detection of Pseudomonas spp. in environmental samples. Phylogenetic relationships inferred from the newly sequenced gacA fragments and the sequences of gacA homologues present in the databases, showed six distinct clusters that correspond to the following bacterial families: Pseudomonaceae, Enterobacteriaceae, Alteromonadaceae, Vibrionaceae, Burkholderia and Xanthomonas. Within the Pseudomonadaceae and Enterobacteriaceae, polymorphisms within gacA and its homologues allowed identification of six and five subclusters respectively. Comparison of the gacA gene and GacA protein‐based trees with the tree inferred from 16S rDNA sequences yielded a similar overall clustering. These results suggest that gacA and its homologues may provide complementary markers for phylogenetic studies of Pseudomonas spp. and Gram‐negative bacteria other than Pseudomonas.
Diverse microbial communities inhabit Antarctic sponges
Authors: Webster Nicole S. , Negri Andrew P. , Munro Murray M. H. G. , Battershill Christopher N.
Published: December 2004

Genetic techniques were employed to investigate the archaeal, bacterial and eukaryotic communities associated with the Antarctic sponges Kirkpatrickia varialosa, Latrunculia apicalis, Homaxinella balfourensis, Mycale acerata and Sphaerotylus antarcticus. The phylogenetic affiliation of sponge‐derived bacteria was assessed by 16S rRNA sequencing of cloned DNA fragments. Denaturing gradient gel electrophoresis (DGGE) was used to determine the stability of bacterial associations within each sponge species and across spatial scales. Of the 150 archaeal clones from L. apicalis, K. varialosa and M. acerata screened by restriction fragment length polymorphism (RFLP) analysis, four unique operational taxonomic units (OTUs) were observed and all clustered closely together within the Crenarchaeota. Of the 250 sponge‐derived bacterial clones screened by RFLP analysis, 61 were unique OTUs that were not detected during examination of 160 seawater‐derived clones. Rarefaction analysis indicated that the clone libraries represented between 44 and 83% of the total estimated diversity. Phylogenetic analysis of sequence data revealed that the bacterial communities present in Antarctic sponges primarily clustered within the Gamma and Alpha proteobacteria and the Cytophaga/Flavobacterium of Bacteroidetes group. Bacterial DGGE analysis for replicate sponge and seawater samples at each Antarctic site revealed that bacterial communities were consistently detected within a particular species regardless of the collection site, with six bacterial bands exclusively associated with a single sponge species. Phylogenetic analysis of sequence data from eukaryotic DGGE analysis revealed that the communities present in Antarctic sponges fell into diatom and dinoflagellate clusters with many sequences having no known close relatives. In addition, seven eukaryotic sequences that were not detected in seawater samples or other sponge species were observed in K. varialosa.
Variations in the abundance and identity of class II aromatic ring‐hydroxylating dioxygenase genes in groundwater at an aromatic hydrocarbon‐contaminated site
Authors: Taylor Paul M. , Janssen Peter H.
Published: December 2004

The abundance of genes encoding aromatic ring‐hydroxylating dioxygenases (RHDs) in the groundwater at an aromatic hydrocarbon‐contaminated landfill near Sydney, Australia, was determined by quantitative DNA–DNA hybridization using class II RHD genes as probes. There were marked differences in hybridization signal intensity against DNA extracted from the groundwater at seven different locations across this heterogeneous site. This was interpreted as indicating variation in RHD gene abundance. Clone libraries of polymerase chain reaction (PCR)‐amplified RHD gene fragments were constructed from DNA from each of the groundwater samples. The libraries from the samples with greater RHD gene abundance were dominated by a group of bacterial class II RHD genes, designated the S‐cluster, that has yet to be found in cultured isolates. These groundwater samples contained no detectable petroleum hydrocarbons. A second group of class II RHD gene sequences, designated the T‐cluster, dominated RHD gene clone libraries prepared from groundwater samples that contained detectable levels of total petroleum and aromatic hydrocarbons but lower RHD gene abundance. The hosts and in situ expression of these novel genes, and the substrates of the enzymes they encode, remain unknown. The scarcity of genes from known aromatic hydrocarbon‐degrading bacteria and the numerical dominance of the novel genes suggest that the hosts of these novel genes may play an important role in aromatic hydrocarbon degradation at this site.
Developments in treatment of primary irresectable rectal cancer
Authors: Reerink O. , Mulder N. H. , Szabo B. G. , Sluiter W. J. , Wiggers T. , Bongaerts A. H. H. , Hospers G. A. P.
Published: December 2004

The treatment options for primary irresectable rectal cancers are discussed. Assessment of tumour stage is the first step for an appropriate choice of treatment. Following a diagnosis of rectal cancer, a vast array of diagnostic procedures is available to determine its stage, and thereby its best treatment options. From the many (new) diagnostic options the merits and drawbacks are discussed. If a diagnosis of irresectability is made, further treatment options should include radiotherapy in most cases, some aspects of timing and application, i.e. intra‐operative treatment are discussed. Chemotherapy options are manifold, the results are discussed and some new options are explored.
Local resection of rectal tumours using the Salvati operating proctoscope – a safe and effective technique
Authors: Zammit M. , O'Dwyer P. , Molloy R.
Published: December 2004

Background  Per‐anal excision can be an effective method for treating large rectal adenomas and selected rectal cancers. This procedure is suitable for adenomas that are too large for colonoscopic excision and for early rectal cancers in patients that are unfit for major resection.

Patients and methods  We retrospectively reviewed 37 patients (16 male, 21 female) that had a local resection using a Salvati operating proctoscope. Fifteen had rectal cancer and 22 had rectal adenoma and all have been followed‐up for a median of 14 months (range 2–65). Most cancers were staged pre‐operatively with endorectal ultrasound and 6 cancer patients received adjuvant therapy.

Results  There were no intra‐operative complications, 6 minor postoperative complications, none requiring re‐intervention (1 peri‐anal haematoma, 2 postoperative anaemia, 2 chest complications, 1 secondary haemorrhage) and no peri‐operative deaths. Lesions were histologically completely excised in 33 (89%). Thirty‐four (92%) did not have any recurrence, 2 (5%) adenomas recurred (both successfully treated with further local resection) and 1 (3%) failed to attend for follow‐up. Six have since died, all from comorbid conditions.

Conclusion  Local resection of rectal tumours using the operating proctoscope is a low cost technique with a low complication rate. Outcome of this treatment is good, and similar to other surgical modalities. Local tumour recurrences are uncommon and can be successfully treated with further local treatment.
Laparoscopic proctocolectomy with restorative ileal‐anal pouch
Authors: Gill T. S. , Karantana A. , Rees J. , Pandey S. , Dixon A. R.
Published: December 2004

Objective  The aim of the study was to analyse the outcome of restorative proctocolectomy carried out by laparoscopic surgery.

Methods  A prospectively collected electronic database of all colorectal laparoscopic procedures performed between April 2001 and July 2003 has been used to identify surgical outcomes in 14 consecutive patients who have undergone laparoscopic RPC.

Results  Fourteen patients (5 male), median BMI 24 kg/m2 have undergone restorative laparoscopic proctocolectomy over a two year period: 13 (ulcerative colitis, one with cancer) and 1 (FAP). The median operation time was 260 min; time has not decreased with experience. There were no intra‐operative surgical complications or deaths. Patient controlled analgesia continued for a median of 36 h. The median time to diet was 48 h and median hospital stay 7 days; three patients required nasogastric aspiration for delayed gastric emptying. Eighteen regional lymph nodes were retrieved local to the carcinoma. There was one anastomotic leak. All covering stomas were closed by 6 months (12 by eight weeks). All 14 patients are fully continent, able to suppress urgency and have a median pouch frequency of 4/24 h. None admit to having problems with potency, orgasm sensation, ejaculation, micturition. One lady reports dysparunia. All are highly satisfied with functional outcome and cosmesis.

Conclusion  We are encouraged to continue to offer our patients the option of a laparoscopic resection.
A randomised controlled trial of a tailored multifaceted strategy to promote implementation of a clinical guideline on induced abortion care
Authors: Foy R. , Penney G.C. , Grimshaw J.M. , Ramsay C.R. , Walker A.E. , MacLennan G. , Stearns S.C. , McKenzie L. , Glasier A.
Published: December 2004

Objective  To evaluate the effectiveness and efficiency of a tailored multifaceted strategy, delivered by a national clinical effectiveness programme, to implement a guideline on induced abortion.

Design  Cluster randomised controlled trial.

Setting and participants  All 26 hospital gynaecology units in Scotland providing induced abortion care.

Intervention  Following the identification of barriers to guideline implementation, intervention units received a package comprising audit and feedback, unit educational meetings, dissemination of structured case records and promotion of a patient information booklet. Control units received printed guideline summaries alone.

Main outcome measures  Compliance with five key guideline recommendations (primary outcomes) and compliance with other recommendations, patient satisfaction and costs of the implementation strategy (secondary outcomes).

Results  No effect was observed for any key recommendation: appointment with a gynaecologist within five days of referral (odds ratio 0.89; 95% confidence interval 0.50 to 1.58); ascertainment of cervical cytology history (0.93; 0.36 to 2.40); antibiotic prophylaxis or screening for lower genital tract infection (1.70; 0.71 to 5.99); use of misoprostol as an alternative to gemeprost (1.00; 0.27 to 1.77); and offer of contraceptive supplies at discharge (1.11; 0.48 to 2.53). Median pre‐intervention compliance was near optimal for antibiotic prophylaxis and misoprostol use. No intervention benefit was observed for any secondary outcome. The intervention costs an average of £2607 per gynaecology unit.

Conclusions  The tailored multifaceted strategy was ineffective. This was possibly attributable to high pre‐intervention compliance and the limited impact of the strategy on factors outside the perceived control of clinical staff.