bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of experimental venous carbon dioxide embolization on hemodynamic and respiratory variables
Authors: Jersenius U. , Fors D. , Rubertsson S. , Arvidsson D. 
Published: January 2006

Background:  Laparoscopic liver resection is a relatively new surgical procedure. Carbon dioxide (CO2) pneumoperitoneum and laparoscopic liver dissection are recognized as risk factors for CO2 embolism to the pulmonary circulation. The embolization can be difficult to detect and can theoretically increase peri‐operative morbidity. The aim of this study was to evaluate the cardiopulmonary effects in a pig model during a time period of 4 h after an experimental CO2 embolization.Methods:  Eleven piglets were anesthesized. Nine were embolized with a single intravenous injection of 0.4 ml/kg CO2 and two served as controls. Respiratory and cardiovascular variables, including pulmonary artery pressure and cardiac output, were monitored for 4 h after embolization, and arterial blood gases were monitored on‐line.Results:  The embolized piglets had an increase in ventilatory dead space, pulmonary vascular resistance and pulmonary artery pressure and a decrease in cardiac output that lasted throughout the 4‐h observation time. The mean arterial pressure and heart rate were unchanged. An early sign of embolization was a rapid fall in end‐tidal CO2 and Pao2 and a rise in Paco2.Conclusion:  Negative changes in cardiopulmonary physiology persisted for at least 4 h after a single intravenous CO2 injection, in spite of this gas being highly soluble in blood. This is a more prolonged influence of CO2 embolization than previously described. Extensive monitoring for early detection of an embolization may be recommended to limit morbidity in patients undergoing laparoscopic liver surgery.
Ondansetron and tropisetron do not prevent intraspinal morphine‐ and fentanyl‐induced pruritus in elective cesarean delivery
Authors: Sarvela P. J. , Halonen P. M. , Soikkeli A. I. , Kainu J. P. , Korttila K. T. 
Published: January 2006

Background:  Although intraspinal morphine has been shown to be effective in providing analgesia after cesarean delivery, pruritus as a side‐effect remains a common cause of dissatisfaction. The role of ondansetron has been studied in preventing pruritus but the results have been contradictory.Methods:  We randomized 98 parturients undergoing elective cesarean section using combined spinal‐epidural anesthesia into a double‐blinded trial to receive tropisetron 5 mg (T group) or ondansetron 8 mg (O group) or placebo (NaCl group) after delivery, when intrathecal morphine 160 µg and fentanyl 15 µg were used for post‐operative pain control. The patients additionally received ketoprofen 300 mg per day. Post‐operative itching, nausea and vomiting, sedation and need for rescue analgesics were registered every 3 h up to 24 h, and all patients were interviewed on the first post‐operative day.Results:  Seventy‐six percent of the parturients in the placebo group, 87% in the ondansetron, and 79% in the tropisetron group had itching. The incidence of post‐operative nausea and vomiting was 21%, 20% and 11% of the patients in the placebo, ondansetron and tropisetron groups, respectively. Medication for pruritus was needed by 31%, 23% and 39% of the patients in the placebo, ondansetron and tropisetron groups, respectively. In the post‐operative questionnaire, the patients reported less post‐operative nausea in the tropisetron group than in the placebo group (P < 0.01).Conclusion:  Neither ondansetron nor tropisetron prevent itching caused by intrathecal morphine with fentanyl. However, tropisetron reduced post‐operative nausea.
Pyramidodinium atrofuscum gen. et sp. nov. (Dinophyceae), a new marine sand‐dwelling coccoid dinoflagellate from tropical waters
Authors: Horiguchi Takeo , Sukigara Chisa 
Published: January 2006

SUMMARYA new marine sand‐dwelling coccoid dinoflagellate Pyramidodinium atrofuscum Horiguchi et Sukigara gen. et sp. nov. is described from Jellyfish Lake, Republic of Palau. The dinoflagellate alternates a non‐motile vegetative stage with a motile gymnodinioid stage within its life cycle. The non‐motile stage is dominant in the life cycle and the dinoflagellate reproduces itself by means of the production of two motile cells. The released motile cell swims only for a short period and is directly transformed into the non‐motile cell. The non‐motile cell is sessile, pyramidal in shape, with a single longitudinal ridge and a double transverse ridge. The surface of the cell wall is covered with many processes. The motile cell has a Gymnodinium‐like morphology, but no apical groove is present. An ultrastructural study revealed that the dinoflagellate possesses typical dinoflagellate organelles. Based on the unique morphology of the vegetative non‐motile stage, we propose a new genus Pyramidodinium for this dinoflagellate, with the type species Pyramidodinium atrofuscum Horiguchi et Sukigara, gen. et sp. nov.
New records of Peyssonnelia armorica and Peyssonnelia harveyana (Rhodophyta, Gigartinales) from Japan
Authors: Kato Aki , Masuda Michio , Kawai Hiroshi 
Published: January 2006

SUMMARYTwo species of the crustose red algal genus Peyssonnelia (Gigartinales, Peyssonneliaceae) are reported from Japanese waters for the first time. These species share the following combination of vegetative and reproductive features: thalli with appressed margins, perithallial filaments arising from the whole upper surface of each hypothallial cell (the Peyssonnelia rubra‐type anatomy), unicellular rhizoids, hypobasal calcification and spermatangia that are produced in double chains (the Peyssonnelia harveyana‐type spermatangial filament). However, they differ obviously from each other in the hypothallus orientation as seen from below, the perithallus structure in relation to the consistency of the crust, the origin of gonimoblasts and the elevation of the nemathecia. Peyssonnelia armorica is characterized by: (i) hypothallial filaments comprising a polyflabellate layer; (ii) easily separable perithallial filaments in a gelatinous matrix; (iii) gonimoblasts originating exclusively from the auxiliary cell; and (iv) semi‐immersed (slightly elevated) nemathecia. Peyssonnelia harveyana is characterized by: (i) hypothallial filaments arranged in parallel rows; (ii) closely packed perithallial filaments in a firm matrix; (iii) gonimoblsts originating from both the auxiliary cell and the connecting filament; and (iv) conspicuously elevated nemathecia.
Lotharella vacuolata sp. nov., a new species of chlorarachniophyte algae, and time‐lapse video observations on its unique post‐cell division behavior
Authors: Ota Shuhei , Ueda Kunihiko , Ishida Ken‐ichiro 
Published: January 2006

SUMMARYA new species of chlorarachniophyte alga, Lotharella vacuolata Ota et Ishida sp. nov., is described. This alga has been maintained as strain CCMP240 at the Provasoli‐Guillard National Center for Culture of Marine Phytoplankton at Bigelow Laboratory for Ocean Sciences. We examined in detail its morphology, ultrastructure and life cycle, using light microscopy, transmission electron microscopy and time‐lapse videomicroscopy. The dominant stage in the life cycle was represented by coccoid cells; however, amoeboid and flagellated stages were also observed. This alga showed unique post‐cell division behavior: one of the two daughter cells became amoeboid and escaped through a pore on the parental cell wall; the other daughter cell remained within the parental cell wall. Pyrenoid ultrastructure and nucleomorph location, which are used as the main generic criteria of chlorarachniophytes, confirmed that the strain CCMP240 is a member of Lotharella. This alga, however, was clearly distinguished from other known Lotharella species by the presence of large vacuoles, unusual post‐cell division behavior and some unique ultrastructural characters.
Morphology of Dictyopteris punctata (Dictyotales, Phaeophyceae)
Authors: Hasegawa Kazukiyo , Tanaka Jiro 
Published: January 2006

SUMMARYTaxonomic re‐examination of Dictyopteris punctata Noda revealed vegetative and reproductive characters that were not described in the original description. The outer one‐fifth to two‐fifths of the blade margin was monostromatic. Reproductive organs of female and male gametophytes were observed for the first time. All reproductive organs (sporangia, oogonia, antheridia) were formed on middle to upper parts of thalli and between the midrib and distromatic area of the blades, and never produced on the monostromatic areas. Maturation starts earlier at the lower part. Sporangia were solitary and scattered. Oogonia were scattered singly or in small groups and more densely distributed than sporangia. Antheridial sori were scattered around a midrib, and raised above the wing surfaces. Antheridia were taller around the midrib than in the middle part of a wing. The monostromatic wings and lack of distinct oogonial sori are new taxonomic characters of Dictyopteris punctata and further define this species with scattered sporangia, the taxonomic character hitherto used.
Confirmation of cultivated Porphyra tenera (Bangiales, Rhodophyta) by polymerase chain reaction restriction fragment length polymorphism analyses of the plastid and nuclear DNA
Authors: Niwa Kyosuke , Kobiyama Atsushi , Aruga Yusho 
Published: January 2006

SUMMARYPolymerase chain reaction restriction fragment length polymorphism (PCR‐RFLP) analysis of the plastid ribulose‐1,5‐bisphosphate carboxylase (RuBisCo) spacer region was developed for a more reliable and rapid species identification of cultivated Porphyra in combination with PCR‐RFLP analysis of the nuclear internal transcribed spacer (ITS) region. From the PCR‐RFLP analyses of the plastid and nuclear DNA, we examined seven strains of conchocelis that were used for cultivation as Porphyra tenera Kjellman but without strict species identification. The PCR‐RFLP analyses suggested that two strains, C‐32 and 90‐02, were cultivated P. tenera and that the other five strains, C‐24, C‐28, C‐29, C‐30 and M‐1, were Porphyra yezoensis f. narawaensis Miura. To identify species more accurately and to reveal additional genetic variation, the two strains C‐32 and 90‐02 were further studied by sequencing their RuBisCo spacer and ITS‐1 regions. Although RuBisCo spacer sequences of the two strains were identical to each other, each of their ITS‐1 sequences showed a single substitution. The sequence data again confirmed that the two strains (C‐32 and 90‐02) were cultivated P. tenera, and suggested that the two strains showed some genetic variation. We concluded that PCR‐RFLP analysis of the plastid and nuclear DNA is a powerful tool for reliable and rapid species identification of many strains of cultivated Porphyra in Japan and for the collection of genetically variable breeding material of Porphyra.
Stimulation of D1‐like or D2 dopamine receptors in the shell, but not the core, of the nucleus accumbens reinstates cocaine‐seeking behaviour in the rat
Authors: Schmidt Heath D. , Anderson Sharon M. , Pierce R. Christopher 
Published: January 2006

AbstractAlthough increases in dopamine transmission in the brain are clearly involved in the reinstatement of cocaine seeking, the role of nucleus accumbens dopamine in cocaine priming‐induced reinstatement remains controversial. The goal of these experiments was to evaluate the relative contributions of D1‐like and D2‐like dopamine receptors in the nucleus accumbens core and shell in the reinstatement of cocaine‐seeking behaviour. Initially, rats were trained to press a lever for cocaine (0.25 mg, i.v.) using a fixed‐ratio 5 (FR5) schedule of reinforcement. Responding was then extinguished by substituting saline for cocaine. During the reinstatement phase, subtype‐specific dopamine receptor agonists were microinjected into the nucleus accumbens core or medial shell in order to assess their ability to induce cocaine seeking. Administration of the D1/D5 dopamine receptor agonist SKF‐81297 (1.0 µg) into the nucleus accumbens shell, but not core, reinstated drug‐seeking behaviour. Similarly, microinjection of quinpirole (3.0 µg), a D2/D3 dopamine receptor agonist, into the nucleus accumbens shell and not core reinstated drug‐seeking behaviour. In contrast, administration of the D3‐ or D4‐preferring dopamine receptor agonists PD 128,907 (1.5 and 3.0 µg) and PD 168,077 (0.3 and 3.0 µg), respectively, did not promote reinstatement when administered into either the core or the shell. Taken together, these results indicate that activation of D1/D5 or D2 dopamine receptors, in the limbic shell subregion of the nucleus accumbens but not the basal ganglia‐orientated accumbens core, promotes the reinstatement of cocaine‐seeking behaviour.
Spatial discrimination of visually similar environments by hippocampal place cells in the presence of remote recalibrating landmarks
Authors: Paz‐Villagrán V. , Save E. , Poucet B. 
Published: January 2006

AbstractPlace cells in the rat hippocampus commonly show place‐related firing activity in the animal's current environment. Here, we evaluated the capability of the place cell system to discriminate visually identical environments. Place cell activity was first recorded while rats moved freely in a cylinder divided into three connected sectors. Two sectors were visually identical whereas the third sector was made distinctive by the addition of visual and tactile cues. When in a given sector, the rats could not perceive the cues present in the other two sectors. Most cells had distinctive place fields in each sector, including the two identical sectors. To rule out the influence of non‐controlled cues, rotations of the cylinder (± 120 °) were conducted. When successful, cylinder rotations resulted in equivalent field rotation for all cells. These results suggest that the place cell system is able to form a specific spatial representation for all sectors, so that the rat knows, at any time, in which sector it is currently located. Presumably, such discrimination relies on angular path integration in which the computational errors stemming from self‐motion cues would be corrected by environmental landmarks provided by the distinctive sector.
Plasticity‐related regulation of the hippocampal proteome
Authors: McNair Kara , Davies Ceri H. , Cobb Stuart R. 
Published: January 2006

AbstractPlasticity of glutamatergic synapses is considered to be a pivotal mechanism underlying the ability of the CNS to reconfigure its neural circuits. A large number of studies have focused on investigating how individual proteins, biochemical pathways and structural processes alter both the induction and maintenance of synaptic plasticity. However, it is likely that synaptic plasticity involves temporally and spatially coordinated regulation of multiple protein complexes within the activated neural circuit. By using a global proteomics‐based approach we have now been able to reveal that highly diverse protein classes exhibit altered expression in response to both the activation of glutamate receptors and the induction of long‐term potentiation (LTP) of glutamatergic synaptic strength in the hippocampus; a brain area where plastic synaptic modification is believed to be key to cognitive processes, such as spatial learning. Of the 2946 resolvable protein spots detected in this study, 79 (2.7%) were significantly altered in abundance in response to 100 µm glutamate application (all P < 0.05). The majority (56 out of 79) of these changes were due to the activation of the N‐methyl‐d‐aspartate (NMDA) subtype of glutamate receptor. Likewise, the induction of LTP was associated with an altered abundance of 2.4% of the detectable proteome during the early (10 min) phase and 1.7% during the late (4 h) phase of its development. Observed changes in temporal and protein class‐specific patterns of expression depict a widespread shift from metabolic to structural protein alteration as the plasticity process matures.
Anti‐apoptotic effects of allopregnanolone on P19 neurons
Authors: Xilouri Maria , Papazafiri Panagiota 
Published: January 2006

AbstractProgesterone and its metabolites are potent allosteric modulators of GABAAreceptor function, through a direct, non‐genomic interaction with specific receptor subtypes. In addition, fluctuations in the concentration of progesterone, and allopregnanolone in particular, have been shown to modulate GABAAreceptor gene expression and activity. In this study, mouse P19 cells were induced to differentiate into post‐mitotic neurons which express specific neuronal markers, including GABAAandN‐methyl‐d‐aspartate (NMDA) receptors. Apoptotic cell death, induced in the presence of NMDA, was efficiently prevented by allopregnanolone and dehydroepiandrosterone (DHEA) but not DHEA sulfate. Apoptosis was accompanied by cytochromecrelease to the cytoplasm and Bax translocation to the mitochondria, while the levels of the anti‐apoptotic proteins Bcl‐2 and Bcl‐xL remained unchanged. In the presence of the most potent neurosteroid, allopregnanolone, DNA fragmentation as well as cytochromecand Bax translocation were prevented. On the other hand, short‐term exposure (1–20 µm, 24 h) of P19‐derived neurons to allopregnanolone and DHEA significantly increased the levels of α1 and β2 mRNAs of GABAAreceptor, while the levels of NR1 mRNA of NMDA receptor were not altered. These results suggest that neurosteroids, interfering with the mitochondrial apoptotic pathway, are able to act as survival factors in neuronal cells, while they contribute to GABAAreceptor plasticity modulating the expression of its subunits.
Characterization of the glycinergic input to bipolar cells of the mouse retina
Authors: Ivanova Elena , Müller Ulrike , Wässle Heinz 
Published: January 2006

AbstractGlycine and γ‐aminobutyric acid (GABA) are the major inhibitory transmitters of the mammalian retina, and bipolar cells receive GABAergic and glycinergic inhibition from multiple amacrine cell types. Here we evaluated the functional properties and subunit composition of glycine receptors (GlyRs) in bipolar cells. Patch‐clamp recordings were performed from retinal slices of wild‐type, GlyRα1‐deficient (Glra1spd‐ot) and GlyRα3‐deficient (Glra3–/–) mice. Whole‐cell currents following glycine application and spontaneous inhibitory postsynaptic currents (IPSCs) were analysed. During the recordings the cells were filled with Alexa 488 and, thus, unequivocally identified. Glycine‐induced currents of bipolar cells were picrotoxinin‐insensitive and thus represent heteromeric channels composed of α and β subunits. Glycine‐induced currents and IPSCs were absent from all bipolar cells of Glra1spd‐ot mice, indicating that GlyRα1 is an essential subunit of bipolar cell GlyRs. By comparing IPSCs of bipolar cells in wild‐type and Glra3–/– mice, no statistically significant differences were found. OFF‐cone bipolar (CB) cells receive a strong glycinergic input from AII amacrine cells, that is preferentially based on the fast α1β‐containing channels (mean decay time constant τ = 5.9 ± 1.4 ms). We did not observe glycinergic IPSCs in ON‐CB cells and could elicit only small, if any, glycinergic currents. Rod bipolar cells receive a prominent glycinergic input that is mainly mediated by α1β‐containing channels (τ = 5.5 ± 1.6 ms). Slow IPSCs, the characteristic of GlyRs containing the α2 subunit, were not observed in bipolar cells. Thus, different bipolar cell types receive kinetically fast glycinergic inputs, preferentially mediated by GlyRs composed of α1 and β subunits.
Activation of α7 acetylcholine receptors augments stimulation‐induced hippocampal theta oscillation
Authors: Siok C. J. , Rogers J. A. , Kocsis B. , Hajós M. 
Published: January 2006

AbstractIn the septohippocampal formation α7 nicotinic receptors (α7 nAChRs) are predominantly expressed by neurons well positioned to modulate hippocampal theta oscillation, such as GABAergic interneurons in the hippocampus, and by both GABAergic and cholinergic septal neurons. In the present experiments, we evaluated the efficacy of the recently developed selective α7 nAChR agonist PNU‐282987 on hippocampal theta oscillation in anaesthetized rats. This compound shows high affinity for the rat α7 nAChRs (Ki = 26 nm) but a negligible activity at other nAChRs. Systemic administration of PNU‐282987 significantly enhanced the power (by 40%) of hippocampal theta oscillation induced by electrical stimulation of the brainstem reticular formation. In contrast, the amnesic and muscarinic receptor antagonist scopolamine significantly decreased the power (by 68%) of the stimulation‐induced theta oscillation. Given the connection between hippocampal theta oscillation and cognitive processes, it is proposed that precognitive actions of α7 nAChR agonists could be mediated, at least in part, by modulation of hippocampal oscillatory activity.
A novel role for calcium‐independent phospholipase A2 in α‐amino‐3‐hydroxy‐5‐methylisoxazole‐propionate receptor regulation during long‐term potentiation
Authors: Martel Marc‐André , Patenaude Christian , Ménard Caroline , Alaux Stéphanie , Cummings Brian S. , Massicotte Guy 
Published: January 2006

AbstractA considerable body of evidence indicates that phospholipase A2 (PLA2) enzymes participate in long‐term potentiation (LTP) of excitatory synaptic transmission. In the present study, we have undertaken experiments to identify which calcium‐independent isoform of PLA2 is involved in synaptic plasticity and to determine whether calcium‐independent PLA2 (iPLA2) contributes to post‐synaptic processes of LTP. Using field recordings from rat CA1 hippocampal slices, we found that theta‐burst stimulation (TBS)‐induced LTP of field excitatory post‐synaptic potentials (fEPSPs) was abolished by the iPLA2 inhibitor bromoenol lactone (BEL) but not by the Ca2+‐dependent PLA2 inhibitor arachidonyl trifluoromethyl ketone (AACOCF3). The ionic currents generated during TBS were not affected during iPLA2 inhibition as BEL by itself had no effect on the magnitude of facilitation during burst responses. In addition, (R)‐BEL, an enantioselective inhibitor of iPLA2γ, precluded TBS‐induced LTP, an action that was not replicated by the iPLA2β inhibitors (S)‐BEL and methyl arachidonyl fluorophosphonate. (R)‐BEL was, however, ineffective on pre‐established LTP. Finally, BEL also prevented the potentiation of fEPSPs elicited by brief exposure to 50 µmN‐methyl‐d‐aspartate, as well as the associated up‐regulation of α‐amino‐3‐hydroxy‐5‐methylisoxazole‐propionate (AMPA) receptor GluR1 subunit levels and the increase of 3H‐AMPA binding in crude synaptic fractions. Collectively, these results unravel a new role for iPLA2γ in LTP, which appears to favor the insertion of AMPA receptors at post‐synaptic membranes.