bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of oncostatin M receptor β in a specific subset of nociceptive sensory neurons
Authors: Tamura Shinobu , Morikawa Yoshihiro , Miyajima Atsushi , Senba Emiko 
Published: June 2003

AbstractOncostatin M belongs to the interleukin‐6 family of cytokines and acts as a multifunctional cytokine during murine embryogenesis and in inflammatory reactions. Although it has been demonstrated that oncostatin M has biological activities on many types of cells, including hepatocytes, dermal fibroblasts and endothelial cells, the roles of oncostatin M in the murine peripheral nervous system remain unclear. Here, we investigated the expression of specific β‐subunit of oncostatin M receptor in the dorsal root ganglia of adult mice. In the adult dorsal root ganglia, β‐subunit of oncostatin M receptor was exclusively expressed in small‐sized neurons. Approximately 13% of total dorsal root ganglia neurons in mice contained β‐subunit of oncostatin M receptor. The double‐immunofluorescence method revealed that approximately 28% of β‐subunit of oncostatin M receptor‐positive neurons contained TrkA immunoreactivity, 63% expressed Ret immunoreactivity and 58% bound isolectin B4. No neuropeptides, including substance P and calcitonin gene‐related peptide, were contained in the neurons. In addition, all β‐subunit of oncostatin M receptor‐positive neurons expressed both vanilloid receptor 1 and P2X3 purinergic receptor. These neurons projected to the inner portion of lamina II in the dorsal horn of spinal cord and the dermis of skin. Seven days after sciatic nerve axotomy, the expression of β‐subunit of oncostatin M receptor was down‐regulated in the lumbar dorsal root ganglia of the injured side. Our study demonstrated that β‐subunit of oncostatin M receptor was expressed in both cell bodies and processes of nonpeptidergic nociceptive neurons in adult mice, suggesting that oncostatin M may affect the nociceptive function of the neurons through the modulation of vanilloid receptor 1 and P2X3 expression.
Metabolic changes after repetitive transcranial magnetic stimulation (rTMS) of the left prefrontal cortex: a sham‐controlled proton magnetic resonance spectroscopy (1H MRS) study of healthy brain
Authors: Michael Nikolaus , Gösling Michael , Reutemann Michael , Kersting Annette , Heindel Walter , Arolt Volker , Pfleiderer Bettina 
Published: June 2003

AbstractRapid transcranial magnetic stimulation is being increasingly used in the treatment of psychiatric disorders, especially major depression. However, its mechanisms of action are still unclear. The aim of this study was to assess metabolic changes by proton magnetic resonance spectroscopy following high‐frequency rapid transcranial magnetic stimulation (20 Hz), both immediately after a single session and 24 h after a series of five consecutive sessions. Twelve healthy volunteers were enrolled in a prospective single‐blind, randomized study [sham (n = 5) vs. real (n = 7)]. Three brain regions were investigated (right, left dorsolateral prefrontal cortex, left anterior cingulate cortex). A single as well as a series of consecutive rapid transcranial magnetic stimulations affected cortical glutamate/glutamine levels. These effects were present not only close to the stimulation site (left dorsolateral prefrontal cortex), but also in remote (right dorsolateral prefrontal cortex, left cingulate cortex) brain regions. Remarkably, the observed changes in glutamate/glutamine levels were dependent on the pre‐transcranial magnetic stimulation glutamate/glutamine concentration, i.e. the lower the pre‐stimulation glutamate/glutamine level, the higher the glutamate/glutamine increase observed after short‐ or long‐term stimulation (5 days). In general, the treatment was well tolerated and no serious side‐effects were reported. Neither transient mood changes nor significant differences in the outcome of a series of neuropsychological test batteries after real or sham transcranial magnetic stimulation occurred in our experiment. In summary, these data indicate that rapid transcranial magnetic stimulation may act via stimulation of glutamatergic prefrontal neurons.
Tremor‐related activity of neurons in the ‘motor’ thalamus: changes in firing rate and pattern in the MPTP vervet model of parkinsonism
Authors: Guehl D. , Pessiglione M. , François C. , Yelnik J. , Hirsch E. C. , Féger J. , Tremblay L. 
Published: June 2003

AbstractThe pathophysiology of parkinsonian tremor remains a matter of debate with two opposing hypotheses proposing a peripheral and a central origin, respectively. A central origin of tremor could arise either from a rhythmic activity of the internal segment of the globus pallidus (GPi) or from a structure such as the thalamus, outside the basal ganglia. In this study, single‐unit recordings were performed in three 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine‐treated monkeys within the GPi and within three territories of the motor thalamus (delimited by their afferent inputs from the GPi, the substantia nigra and the cerebellum, respectively). For each recorded neuron, we compared the variations in firing rate and pattern in tremor and no tremor periods. Tremor either occurred spontaneously or was induced by external stimulation. When the animals entered into a tremor period we observed: (i) an increase in the mean firing rate in about half of the recorded neurons of the motor thalamus; and (ii), a change from an irregular to a rhythmic discharge within the range of tremor frequency (5–7 Hz) in about 10% of the recorded neurons of the motor thalamus (pallidal and cerebellar territories) and the GPi. Most of the thalamic neurons that exhibited a rhythmic discharge during tremor were found to be sensitive to external stimulation. Because the changes in firing rate occurred predominantly in the motor thalamus and not in the GPi, and because a fast rhythmic discharge of 10–15 Hz was frequently observed in the GPi and not in the motor thalamus, we conclude that thalamic activity is not a simple reproduction of basal ganglia output. Moreover, we suggest that thalamic processing of basal ganglia outputs could participate in the genesis of tremor, and that this thalamic processing could be influenced by sensory inputs and/or changes in attentional level elicited by external stimulation.
Perturbation of CD44 function affects chiasmatic routing of retinal axons in brain slice preparations of the mouse retinofugal pathway
Authors: Lin Ling , Chan Sun‐On 
Published: June 2003

AbstractNeurons generated early in development of the ventral diencephalon have been shown to play a key role in defining the midline and the caudal boundary of the optic chiasm in the mouse retinofugal pathway. These functions have been attributed to a surface bound adhesion molecule, CD44 that is expressed in these chiasmatic neurons. In this study, we investigated the effects of perturbing normal CD44 functions on axon routing in brain slice preparations of the mouse retinofugal pathway. Two CD44 antibodies (Hermes‐1 and IM7) were used that bind to distinct epitopes on the extracellular domain of the molecule. We found that both antibodies produced dramatic defects in routing of the retinal axons that arrive early in the chiasm. In preparations of embryonic day 13 (E13) and E14 pathways, the crossed component in the chiasm was significantly reduced after antibody treatment. However, such reduction in axon crossing was not observed in E15 chiasm, indicating that the lately generated crossed axons lost their responses to CD44. Furthermore, the anti‐CD44 treatment produced a reduction in the uncrossed component in the E15 but not in younger pathways, suggesting a selective response of the lately generated axons, mostly from ventral temporal retina, but not those generated earlier, to the CD44 at the chiasmatic midline in order to make their turn for the uncrossed pathway. These findings provide evidence that a normal function of CD44 molecules in the chiasmatic neurons is essential for axon crossing and axon divergence at the mouse optic chiasm.
GAP‐43 mRNA and protein expression in the hippocampal and parahippocampal region during the course of epileptogenesis in rats
Authors: Tolner Else A. , Van Vliet Erwin A. , Holtmaat Anthony J. G. D. , Aronica Eleonora , Witter Menno P. , Da Silva Fernando H. Lopes , Gorter Jan A. 
Published: June 2003

AbstractIn order to reveal axonal rewiring in the hippocampal and parahippocampal regions after status epilepticus, we investigated the temporal evolution of growth‐associated protein‐43 (GAP‐43) mRNA and protein expression in two rat models of mesial temporal lobe epilepsy (MTLE). Status epilepticus (SE) was induced by electrical stimulation of the angular bundle or by intraperitoneal kainic acid (KA) injections. Despite increased GAP‐43 mRNA expression in dentate granule cells at 24 h after SE, GAP‐43 protein expression in the inner molecular layer (IML) of the dentate gyrus decreased progressively after 24 h after SE in both models. Nevertheless robust mossy fiber sprouting (MFS) was evident in the IML of chronic epileptic rats. Remaining GAP‐43 protein expression in the IML in chronic epileptic rats did not correlate with the extent of MFS, but with the number of surviving hilar neurons. In the parahippocampal region, GAP‐43 mRNA expression was decreased in layer III of the medial entorhinal area (MEAIII) in parallel with extensive neuronal loss in this layer. There was a tendency of GAP‐43 mRNA up‐regulation in the presubiculum, a region that projects to MEAIII. With regard to this parahippocampal region, however, changes in GAP‐43 mRNA expression were not followed by protein changes. The presence of the presynaptic protein GAP‐43 in a neurodegenerated MEAIII indicates that fibers still project to this layer. Whether reorganization of fibers has occurred in this region after SE needs to be investigated with tools other than GAP‐43.
Role of heme oxygenase‐1 protein in the neuroprotective effects of cyclopentenone prostaglandin derivatives under oxidative stress
Authors: Satoh Takumi , Baba Megumi , Nakatsuka Daisaku , Ishikawa Yasuyuki , Aburatani Hiroyuki , Furuta Kyoji , Ishikawa Toshihisa , Hatanaka Hiroshi , Suzuki Masaaki , Watanabe Yasuyoshi 
Published: June 2003

AbstractPreviously we found that some cyclopenteone prostaglandin derivatives (PGs), referred to as neurite outgrowth‐promoting PGs (NEPPs), have dual biological activities of promoting neurite outgrowth and preventing neuronal death [Satoh et al. (2000) J. Neurochem., 75, 1092‐1102; Satoh et al. (2001) J. Neurochem., 77, 50‐62; Satoh et al. (2002) In Kikuchi, II. (ed.), Strategenic Medical Science Against Brain Attack. Springer‐Verlag, Tokyo, pp. 78‐93]. To investigate possible cellular mechanisms of the neuroprotective effects, we performed oligo hybridization‐based DNA array analysis with mRNA isolated from HT22, a cell line that originated from a mouse hippocampal neuron. Several transcripts up‐regulated by NEPP11 were identified. Because heme oxygenase 1 (HO‐1) mRNA was the most prominently induced and was earlier reported to protect neuronal and non‐neuronal cells against oxidative stress, we focused on it as a possible candidate responsible for the neuroprotective effects. We found NEPP11 to induce HO‐1 protein (32 kDa) in HT22 cells in both the presence and the absence of glutamate, whereas non‐neuroprotective prostaglandins (PGs) Δ12‐PGJ2 or PGA2 did not. Overexpression of HO‐1‐green fluorescence protein (GFP) fusion protein significantly protected HT22 cells against oxidative glutamate toxicity, whereas that of GFP alone did not. Furthermore, biliverdin and bilirubin, products of HO‐1 enzymatic activity on heme, protected HT22 cells from oxidative glutamate toxicity. These results, together with our previous results, suggest that NEPP11 activates the expression of HO‐1 and that HO‐1 produces biliverdin and bilirubin, which result in the inhibition of neuronal death induced by oxidative stress. NEPP11 is the first molecular probe reported to have a neuroprotective action through induction of HO‐1 in neuronal cells.
A novel Antarctic microbial endolithic community within gypsum crusts
Authors: Hughes Kevin A. , Lawley Blair 
Published: June 2003

SummaryA novel endolithic microbial habitat is described from a climatically extreme site at Two Step Cliffs, Alexander Island, Antarctic Peninsula (71°54′S, 68°13′W). Small endolithic colonies (<3 mm in diameter) are found within the translucent gypsum crust that forms on the surface of sandstone boulders. Gypsum crusts are found on ice‐free rocks throughout the Antarctic and therefore offer potential colonization sites at more inhospitable locations, including sites at higher latitudes. Cyanobacterial, bacterial and fungal components were cultured from the crust material and have been identified as Chloroglea sp., Sphingomonas sp. and Verticillium sp. respectively. A non‐cultured, black‐pigmented fungus was also found. Cyanobacterial primary productivity is low: at depths of 1.2 and 2.5 mm within the crust, estimates of possible cell divisions per year were < 38 and four respectively. This microniche is proposed to provide protection from desiccation, rapid temperature variation and UV radiation flux while allowing penetration of photosynthetically active radiation (PAR) for utilization by phototrophs. The endolithic communities are less extensive than those of the Dry Valleys, continental Antarctica, probably owing to only recent deglaciation (<7000 year ago).
Metabolism of organic compounds in anaerobic, hydrothermal sulphate‐reducing marine sediments
Authors: Tor Jason M. , Amend Jan P. , Lovley Derek R. 
Published: June 2003

SummaryPrevious studies of hot (>80°C) microbial ecosystems have primarily relied on the study of pure cultures or analysis of 16S rDNA sequences. In order to gain more information on anaerobic metabolism by natural communities in hot environments, sediments were collected from a shallow marine hydrothermal vent system in Baia di Levante, Vulcano, Italy and incubated under strict anaerobic conditions at 90°C. Sulphate reduction was the predominant terminal electron‐accepting process in the sediments. The addition of molybdate inhibited sulphate reduction in the sediments and resulted in a linear accumulation of acetate and hydrogen over time. [U‐14C]‐ acetate was completely oxidized to 14CO2, and the addition of molybdate inhibited 14CO2 production by 60%. [U‐14C]‐glucose was oxidized to 14CO2, and this was inhibited when molybdate was added. When the pool sizes of short‐chain fatty acids were artificially increased, radiolabel from [U‐14C]‐glucose accumulated in the acetate pool. L‐[U‐14C]‐glutamate, [ring‐14C]‐benzoate and [U‐14C]‐palmitate were also anaerobically oxidized to 14CO2 in the sediments, but molybdate had little effect on the oxidation of these compounds. These results demonstrate that natural microbial communities living in a hot, microbial ecosystem can oxidize acetate and a range of other organic electron donors under sulphate‐reducing conditions and suggest that acetate is an important extracellular intermediate in the anaerobic degradation of organic matter in hot microbial ecosystems.
An immunomagnetic separation–reverse transcription polymerase chain reaction (IMS‐RT‐PCR) test for sensitive and rapid detection of viable waterborne Cryptosporidium parvum
Authors: Hallier‐Soulier Sylvie , Guillot Emmanuelle 
Published: June 2003

SummaryThe public health problem posed by the waterborne parasite Cryptosporidium parvum incited the water supply industry to develop very accurate analytical tools able to assess the presence of viable oocysts in drinking water. In this study, we report the development of a viability assay for C. parvum oocysts based on immunomagnetic separation and reverse transcription polymerase chain reaction (IMS‐RT‐PCR). The detection limit of the IMS‐RT‐PCR assay, which targets the hsp70 heat shock‐induced mRNA, was in the range of ten viable oocysts per 100‐l tap water samples. Purified Cryptosporidium parvum oocysts were exposed to heating, freezing and three chemical disinfection treatments namely, chlorination, chlorine dioxide treatment and ozonation under conventional doses used in water treatment plants, then detected by IMS‐PCR and IMS‐RT‐PCR. The results obtained by IMS‐PCR showed that none of the treatments had an effect on oocyst detection. The inactivation of oocysts by boiling resulted in no RT‐PCR signal. Chlorine as well as chlorine dioxide did not influence oocyst viability as determined by IMS‐RT‐PCR. Ozone more effectively inactivated oocysts. The IMS‐RT‐PCR assay in conjunction with IMS‐PCR marks the development of a combined detection and viability test which can be used for drinking water quality control as well as for reliable evaluation of treatment efficiency.
Method of DNA extraction and application of multiplex polymerase chain reaction to detect toxigenic Vibrio cholerae O1 and O139 from aquatic ecosystems
Authors: Rivera Irma N. G. , Lipp Erin K. , Gil Ana , Choopun Nipa , Huq Anwar , Colwell Rita R. 
Published: June 2003

Summary Vibrio cholerae is a free‐living bacterium found in water and in association with plankton. V. cholerae non‐O1/non‐O139 strains are frequently isolated from aquatic ecosystems worldwide. Less frequently isolated are V. cholerae O1 and V. cholerae O139, the aetiological agents of cholera. These strains have two main virulence‐associated factors, cholera toxin (CT) and toxin co‐regulated pilus (TCP). By extracting total DNA from aquatic samples, the presence of pathogenic strains can be determined quickly and used to improve a microbiological risk assessment for cholera in coastal areas. Some methods suggested for DNA extraction from water samples are not applicable to all water types. We describe here a method for DNA extraction from coastal water and a multiplex polymerase chain reaction (PCR) for O1 and O139 serogroups. DNA extraction was successfully accomplished from 117 sea water samples collected from coastal areas of Perú, Brazil and the USA. DNA concentration in all samples varied from 20 ng to 480 µg µl−1. The sensitivity of the DNA extraction method was 100 V. cholerae cells in 250 ml of water. The specificity of multiplex O1/O139 PCR was investigated by analysing 120 strains of V. cholerae, Vibrio and other Bacteria species. All V. cholerae O1 and O139 tested were positive. For cholera surveillance of aquatic environments and ballast water, total DNA extraction, followed by V. cholerae PCR, and O1/O139 serogroup and tcpA/ctxA genes by multiplex PCR offers an efficient system, permitting risk analysis for cholera in coastal areas.
Nitrite reductase activity of sulphate‐reducing bacteria prevents their inhibition by nitrate‐reducing, sulphide‐oxidizing bacteria
Authors: Greene E. A. , Hubert C. , Nemati M. , Jenneman G. E. , Voordouw G. 
Published: June 2003

SummarySulphate‐reducing bacteria (SRB) can be inhibited by nitrate‐reducing, sulphide‐oxidizing bacteria (NR‐SOB), despite the fact that these two groups are interdependent in many anaerobic environments. Practical applications of this inhibition include the reduction of sulphide concentrations in oil fields by nitrate injection. The NR‐SOB Thiomicrospira sp. strain CVO was found to oxidize up to 15 mM sulphide, considerably more than three other NR‐SOB strains that were tested. Sulphide oxidation increased the environmental redox potential (Eh) from −400 to +100 mV and gave 0.6 nitrite per nitrate reduced. Within the genus Desulfovibrio, strains Lac3 and Lac6 were inhibited by strain CVO and nitrate for the duration of the experiment, whereas inhibition of strains Lac15 and D. vulgaris Hildenborough was transient. The latter had very high nitrite reductase (Nrf) activity. Southern blotting with D. vulgaris nrf genes as a probe indicated the absence of homologous nrf genes from strains Lac3 and Lac6 and their presence in strain Lac15. With respect to SRB from other genera, inhibition of the known nitrite reducer Desulfobulbus propionicus by strain CVO and nitrate was transient, whereas inhibition of Desulfobacterium autotrophicum and Desulfobacter postgatei was long‐lasting. The results indicate that inhibition of SRB by NR‐SOB is caused by nitrite production. Nrf‐containing SRB can overcome this inhibition by further reducing nitrite to ammonia, preventing a stalling of the favourable metabolic interactions between these two bacterial groups. Nrf, which is widely distributed in SRB, can thus be regarded as a resistance factor that prevents the inhibition of dissimilatory sulphate reduction by nitrite.
Development and validation of a diagnostic microbial microarray for methanotrophs
Authors: Bodrossy Levente , Stralis‐Pavese Nancy , Murrell J. Colin , Radajewski Stefan , Weilharter Alexandra , Sessitsch Angela 
Published: June 2003

SummaryThe potential of DNA microarray technology in high‐throughput detection of bacteria and quantitative assessment of their community structures is widely acknowledged but has not been fully realised yet. A generally applicable set of techniques, based on readily available technologies and materials, was developed for the design, production and application of diagnostic microbial microarrays. A microarray targeting the particulate methane monooxygenase (pmoA) gene was developed for the detection and quantification of methanotrophs and functionally related bacteria. A microarray consisting of a set of 59 probes that covers the whole known diversity of these bacteria was validated with a representative set of extant strains and environmental clones. The potential of the pmoA microarray was tested with environmental samples. The results were in good agreement with those of clone library sequence analyses. The approach can currently detect less dominant bacteria down to 5% of the total community targeted. Initial tests assessing the quantification potential of this system with artificial PCR mixtures showed very good correlation with the expected results with standard deviations in the range of 0.4–17.2%. Quantification of environmental samples with this method requires the design of a reference mixture consisting of very close relatives of the strains within the sample and is currently limited by biases inherent in environmental DNA extraction and universal PCR amplification.
Nitrogenase gene diversity and microbial community structure: a cross‐system comparison
Authors: Zehr Jonathan P. , Jenkins Bethany D. , Short Steven M. , Steward Grieg F. 
Published: June 2003

SummaryBiological nitrogen fixation is an important source of fixed nitrogen for the biosphere. Microorganisms catalyse biological nitrogen fixation with the enzyme nitrogenase, which has been highly conserved through evolution. Cloning and sequencing of one of the nitrogenase structural genes, nifH, has provided a large, rapidly expanding database of sequences from diverse terrestrial and aquatic environments. Comparison of nifH phylogenies to ribosomal RNA phylogenies from cultivated microorganisms shows little conclusive evidence of lateral gene transfer. Sequence diversity far outstrips representation by cultivated representatives. The phylogeny of nitrogenase includes branches that represent phylotypic groupings based on ribosomal RNA phylogeny, but also includes paralogous clades including the alternative, non‐molybdenum, non‐vanadium containing nitrogenases. Only a few alternative or archaeal nitrogenase sequences have as yet been obtained from the environment. Extensive analysis of the distribution of nifH phylotypes among habitats indicates that there are characteristic patterns of nitrogen fixing microorganisms in termite guts, sediment and soil environments, estuaries and salt marshes, and oligotrophic oceans. The distribution of nitrogen‐fixing microorganisms, although not entirely dictated by the nitrogen availability in the environment, is non‐random and can be predicted on the basis of habitat characteristics. The ability to assay for gene expression and investigate genome arrangements provides the promise of new tools for interrogating natural populations of diazotrophs. The broad analysis of nitrogenase genes provides a basis for developing molecular assays and bioinformatics approaches for the study of nitrogen fixation in the environment.