bluuebunny/crossref_metadata_2025 huggingface dataset:
EARLY STRUCTURAL CHANGES OF AORTIC WALL IN SINOAORTIC‐DENERVATED RATS
Authors: Shen Fu‐Ming , Zhang Shu‐Hui , Xie He‐Hui , Jing Qing , Wang Di‐Song , Su Ding‐Feng
Published: March 2006

The present work was designed to observe the early structural changes in the aortic wall in Sprague‐Dawley rats 1, 2 and 4 weeks after sinoaortic denervation (SAD).

Rats were examined 1, 2 and 4 weeks after SAD. Blood pressure (BP) was recorded in the conscious state. The thoracic aortas were taken for investigations, including: light microscopy, electron microscopy, immunohistochemistry and terminal deoxynucleotidyl transferase (TdT)‐mediated dUTP nick‐end labelling (TUNEL).

Blood pressure variability (BPV) was significantly increased in the SAD groups 1, 2 and 4 after the operation when compared with the sham‐operated ones.

Two weeks after SAD the percentage proportion of smooth muscle cell density (SMC%) was obviously increased.

Four weeks after SAD: the SMC%, percentage proportion of collagen density (CD%) and aortic wall thickness (WT) were obviously increased with vascular smooth muscle cells blebbing concomitantly. Endothelial cells showed degenerative changes and swelling with blebbing of the cell membrane and increased condensation of peripheral nuclear chromatin and cytoplasmic vacuolization. It was also found that the number of apoptotic endothelial cells was increased and expression of eNOS was reduced.

This is the first study that shows the time‐course of aortic wall and endothelial cell changes induced by SAD. Increased BPV might be the priming factor in the development of organ damage induced by SAD.
IN VITRO NEUROTOXIC AND MYOTOXIC EFFECTS OF THE VENOM FROM THE BLACK WHIP SNAKE (DEMANSIA PAPUENSIS)
Authors: Kuruppu S , Fry Bryan G , Hodgson Wayne C
Published: March 2006

Black whip snakes belong to the family elapidae and are found throughout the northern coastal region of Australia. The black whip snake (Demansia papuensis) is considered to be potentially dangerous due to its size and phylogenetic distinctiveness. Previous liquid chromatography–mass spectrometry analysis of D. papuensis venom indicated a number of components within the molecular mass ranges compatible with neurotoxins. For the first time, this study examines the in vitro neurotoxic and myotoxic effects of the venom from D. papuensis.

Venom (10 mg/mL) caused significant inhibition of twitches elicited by stimulation (0.2 ms, 0.1 Hz, supramaximal V) of motor nerves in the chick biventer cervicis nerve‐muscle preparation. This neurotoxic effect, which was postsynaptic in origin, was weak in comparison to that of most other Australian elapids. Prior addition (10 min) of polyvalent (PSAV) or tiger snake (TSAV) antivenom (5 units/mL) prevented venom‐induced twitch inhibition. Addition of PSAV (5 units/mL) at t50 failed to reverse the inhibitory effect but prevented further inhibition of nerve‐mediated twitches.

The venom (20–50 mg/mL) is also myotoxic as indicated by a slowly developing contracture and inhibition of twitches elicited by direct stimulation (2 ms, 0.1 Hz, supramaximal V, in the presence of tubocurarine 10 mmol/L) of the chick biventer muscle. This activity was confirmed by histological examination of the muscle.

Fractionation and characterization of venom components is required to further investigate the reasons for the weak neurotoxic activity of D. papuensis venom.
EFFECTS OF ORAL BERAPROST SODIUM, A PROSTAGLANDIN I2 ANALOGUE, ON ENDOTHELIUM DEPENDENT VASODILATATION IN THE FOREARM OF PATIENTS WITH CORONARY ARTERY DISEASE
Authors: Ohata Shuzo , Ishibashi Yutaka , Shimada Toshio , Takahashi Nobuyuki , Sugamori Takashi , Sakane Takeshi , Hirano Yoshifumi , Oyake Nobuyuki , Murakami Yo , Higami Tetsuya
Published: March 2006

Previous clinical studies with prostaglandin I2 (PGI2) analogue beraprost sodium suggested the potential effects on protection of cardiovascular events in patients with peripheral artery disease. Although the mechanism is not well known, experimental studies have shown protective effects of endothelial cells. This study was designed to examine the effects of beraprost sodium on vascular endothelial function in the forearm of patients with coronary artery disease.

Beraprost sodium (120 mg/day) was orally administered to 14 coronary artery disease patients for 4 weeks and then stopped for 4 weeks. Eleven control patients did not receive beraprost sodium treatment. Reactive hyperemia was induced in the forearm, endothelium‐dependent vasodilatation was assessed by plethysmography, and urinary 8‐iso‐prostaglandin F2a (8‐iso‐PGF2a) was measured at baseline, 4 weeks and 8 weeks.

Both groups had similar reactive hyperemic responses at baseline. In the control group, reactive hyperemic response and urinary 8‐iso‐PGF2a remained unchanged for 8 weeks. In the beraprost group, maximum forearm blood flow increased significantly (P = 0.01) after 4 weeks of treatment and returned to baseline at 8 weeks. Duration of hyperemia increased significantly (P = 0.003) after 4 weeks, and remained greater than baseline at 8 weeks (P = 0.02). Urinary 8‐iso‐PGF2a decreased significantly (P = 0.03) after 4 weeks, and tended to be lower at 8 weeks (P = 0.07). Changes in reactive hyperemia correlated weakly but significantly with changes in 8‐iso‐PGF2a (P < 0.001).

Beraprost sodium decreased oxidative stress and improved forearm endothelium‐dependent vasodilatation in coronary artery disease patients. The favorable effects on vascular endothelium could potentially lead to a decrease in vascular events.
Rotavirus double‐stranded RNA induces apoptosis and diminishes wound repair in rat intestinal epithelial cells
Authors: SATO AKIKO , IIZUKA MASAHIRO , NAKAGOMI OSAMU , SUZUKI MANABU , HORIE YASUO , KONNO SHIHO , HIRASAWA FUJIKO , SASAKI KENJI , SHINDO KENICHI , WATANABE SUMIO
Published: March 2006

Background:  Recent studies have shown that toll‐like receptor 3 (TLR3) recognizes double‐stranded RNA (dsRNA). Rotaviruses, having a dsRNA genome, infect intestinal epithelial cells (IEC) and cause acute gastroenteritis in young children. The aim of the present study was to clarify the pathophysiological function of rotavirus dsRNA in IEC.

Methods:  Expression of TLR3 mRNA or protein in IEC cell lines (IEC‐6, HT‐29, Caco‐2) was assessed by reverse transcription polymerase chain reaction (RT–PCR), Western blot analysis or immunohistochemistry. Induction of cytokines (TNF‐α, interferon‐β, interleukin‐6) mRNA and activation of signal proteins (ERK1/2 MAPK and IκB‐α) in IEC after stimulation with rotavirus dsRNA were assessed by RT–PCR or Western blot analysis. IEC‐6 cells were wounded and cell migration into wound areas after stimulation with rotavirus dsRNA (1–25 µg/mL) was assessed. Induction of apoptosis after stimulation with rotavirus dsRNA was also assessed.

Results:  Expression of TLR3 mRNA and TLR3 protein was detected in IEC. Expression of TLR3 mRNA in IEC‐6 tended to be up‐regulated by exposure to IFN‐γ. Induction of cytokine mRNA and activation of the signal proteins were detected after stimulation with rotavirus dsRNA. Apoptosis was induced and epithelial migration into the wound area was dose‐dependently diminished (44.1–94.4%, P < 0.01) by exposure to rotavirus dsRNA. Diminishment of wound repair was suppressed by anti‐TLR3 antibody or caspase inhibitor.

Conclusion:  Rotavirus dsRNA induces severe apoptosis and diminishes wound repair in IEC through TLR3, which might be involved in the pathogenesis of rotavirus‐induced enteritis.
Late onset autoimmune thrombocytopenia associated with pegylated interferon‐α‐2b plus ribavirin treatment for chronic hepatitis C
Authors: Elefsiniotis Ioannis S , Pantazis Konstantinos D , Fotos Nikolaos V , Moulakakis Antonios , Mavrogiannis Christos
Published: March 2006

Interferon‐induced, immune‐mediated, thrombocytopenia is a rare event. In this report the case is described of development of severe, reversible, autoimmune thrombocytopenia in a patient with chronic hepatitis C virus infection, 6 months after the discontinuation of pegylated interferon‐α‐2b plus ribavirin treatment. Physicians must be aware that autoimmune thrombocytopenia can occur even after the end of treatment, as a late onset complication, especially when using the pegylated forms of interferons, which have longer half‐lives and prolonged activity.
Population‐based study of the relationship between mutations in the hemochromatosis (HFE) gene and arthritis
Authors: Sherrington Colin A , Knuiman Matthew W , Divitini Mark L , Bartholomew Helen C , Cullen Digby J , Olynyk John K
Published: March 2006

Background and Aim:  Mutations in the hemochromatosis (HFE) gene are carried by one in three individuals of British Isles descent and may result in increased iron stores. These increased iron stores could potentially induce or exacerbate diseases, such as arthritis, in which iron has a role in pathogenesis. Although arthritis is a well‐known association of clinically overt hereditary hemochromatosis, controversy surrounds the role of mutations in the HFE gene as risk factors for arthritis. The aim of the present study was to determine whether mutations in the HFE gene are associated with an increased prevalence of arthritis.

Methods:  A population‐based study was conducted in Busselton, Western Australia, of the prevalence of arthritis in 1372 individuals of British Isles descent. Participants completed a questionnaire and general physical examination. Analysis for C282Y and H63D HFE mutations was undertaken. Unadjusted and adjusted odds ratios (OR) were calculated for the relationship between HFE mutations and the prevalence of self‐reported, doctor‐diagnosed arthritis.

Results:  There was no association between the presence of HFE mutations and the prevalence of self‐reported, doctor‐diagnosed arthritis (C282Y/wild type (WT) adjusted OR = 1.041 (95% confidence interval (CI) 0.68–1.61), H63D/WT OR = 0.76 (95% CI 0.53–1.08), C282Y/C282Y OR = 0.39 (95% CI 0.04–3.63), C282Y/H 63D OR = 0.808 (95% CI 0.27–2.42), H63D/H63D OR = 0.419 (95% CI 0.13–1.36)). Overall adjusted OR for arthritis in participants with one or more HFE mutations was 0.81 (95% CI 0.61–1.09).

Conclusions:  Mutations of the HFE gene are not risk factors for arthritis in populations of British Isles descent.
Childhood pancreatitis
Authors: Nydegger Andy , Couper Richard T L , Oliver Mark R
Published: March 2006

Inflammation of the pancreas has many presentations in children and adolescents. The etiology is often elusive, with a great number of cases being idiopathic. However, there have been a number of recent advances in the areas of cell biology, genetics and imaging technology, which should be highlighted. Herein is provided a review for the reader with particular emphasis on some of these newer advances.
Asian contribution to living donor liver transplantation
Authors: Lee Sung‐Gyu
Published: March 2006

Although the shortage of brain‐dead donor organs is a worldwide problem, the situation is especially serious in Asia because of various cultural and social reasons, and cadaveric organ donation remains below 5 per million population per year. Living donor liver transplantation (LDLT) could provide an alternative for liver graft for patients with acute and chronic end‐stage liver disease. This article introduces the important contributions to the development of LDLT by the leading Asian liver transplantation centers. The first successful adult LDLT using a left‐lobe graft was reported by Makuuchi et al. from Japan in 1994. To overcome the barrier of graft‐size matching for adult patients with use of a left‐lobe graft, a trial of adult LDLT using a right‐lobe graft with middle hepatic vein was reported with satisfactory outcome by Fan et al. from Hong Kong in 1997. Despite the impressive results of right‐lobe LDLT, considerable debate persists concerning donor safety. Lee et al. from Korea initiated modified right‐lobe liver grafting with interposition vein grafts to drain anterior segment and two left‐lobe liver grafting to overcome graft‐size insufficiency and to ensure donor safety in 1999 and 2000, respectively. In addition to technical innovations, indications for liver transplantation have been developed by Asian centers as LDLT activity has increased.
Hippocampal up‐regulation of NCAM expression and polysialylation plays a key role on spatial memory
Authors: Venero César , Herrero Ana I. , Touyarot Katia , Cambon Karine , López‐Fernández Miguel A. , Berezin Vladimir , Bock Elisabeth , Sandi Carmen
Published: March 2006

Memory formation has been associated with structural and functional modifications of synapses. Cell adhesion molecules are prominent modulators of synaptic plasticity. Here, we investigated the involvement of the cell adhesion molecules, NCAM, its polysialylated state (PSA‐NCAM) and L1 in spatial learning‐induced synaptic remodeling and memory storage. A differential regulation of these adhesion molecules was found in the hippocampus of rats submitted to one training session in the spatial, but not cued, version of the Morris water maze. Twenty‐four hours after training, synaptic expression of NCAM and PSA‐NCAM was increased, whereas L1 appeared markedly decreased. The regulation of these molecules was spatial learning‐specific, except for L1 reduction, which could be attributed to swimming under stressful conditions rather than to learning. Subsequent psychopharmacological experiments were performed to address the functional role of NCAM and PSA‐NCAM in the formation of spatial memories. Rats received an intracerebroventricular injection of either a synthetic peptide (C3d) aimed to interfere with NCAM function, or endoneuraminidase, an enzyme that cleaves polysialic acid from NCAM. Both treatments affected acquisition of spatial information and lead to impaired spatial memory abilities, supporting a critical role of the observed learning‐induced up‐regulation of synaptic NCAM expression and polysialylation on spatial learning and memory. Therefore, our findings highlight NCAM as a learning‐modulated molecule critically involved in the hippocampal remodeling processes underlying spatial memory formation.
Differential effects of low glucose concentrations on seizures and epileptiform activity in vivo and in vitro
Authors: Kirchner Anne , Velíšková Jana , Velíšek Libor
Published: March 2006

In vivo, severe hypoglycemia is frequently associated with seizures. The hippocampus is a structure prone to develop seizures and seizure‐induced damage. Patients with repeated hypoglycemic episodes have frequent memory problems, suggesting impaired hippocampal function. Here we studied the effects of moderate hypoglycemia on primarily generalized flurothyl‐induced seizures in vivo and, using EEG recordings, we determined involvement of the hippocampus in hypoglycemic seizures. Moderate systemic hypoglycemia had proconvulsant effects on flurothyl‐induced clonic (forebrain) seizures. During hypoglycemic seizures, seizure discharges were recorded in the hippocampus. Thus, we continued the studies in combined entorhinal cortex–hippocampus slices in vitro. However, in vitro, decreases in extracellular glucose from baseline 10 mm to 2 or 1 mm did not induce any epileptiform discharges. In fact, low glucose (2 and 1 mm) attenuated preexisting low‐Mg2+‐induced epileptiform activity in the entorhinal cortex and hippocampal CA1 region. Osmolarity compensation in low‐glucose solution using mannitol impaired slice recovery. Additionally, using paired‐pulse stimuli we determined that there was no impairment of GABAA inhibition in the dentate gyrus during glucopenia. The data strongly indicate that, although forebrain susceptibility to seizures is increased during moderate in vivo hypoglycemia and the hippocampus is involved during hypoglycemic seizures, glucose depletion in vitro contributes to an arrest of epileptiform activity in the system of the entorhinal cortex–hippocampus network and there is no impairment of net GABAA inhibition during glucopenia.
Localization of metabotropic GABA receptor subunits GABAB1 and GABAB2 relative to synaptic sites in the rat developing cerebellum
Authors: Luján R. , Shigemoto R.
Published: March 2006

The highest densities of the two metabotropic GABA subunits, GABAB1 and GABAB2, have been reported as occurring around the glutamatergic synapses between Purkinje cell spines and parallel fibre varicosities. In order to determine how this distribution is achieved during development, we investigated the expression pattern and the cellular and subcellular localization of the GABAB1 and GABAB2 subunits in the rat cerebellum during postnatal development. At the light microscopic level, immunoreactivity for the GABAB1 and GABAB2 subunits was very prominent in the developing molecular layer, especially in Purkinje cells. Using double immunofluorescence, we demonstrated that GABAB1 was transiently expressed in glial cells. At the electron microscopic level, immunoreactivity for GABAB receptors was always detected both pre‐ and postsynaptically. Presynaptically, GABAB1 and GABAB2 were localized in the extrasynaptic membrane of parallel fibres at all ages, and only rarely in GABAergic axons. Postsynaptically, GABAB receptors were localized to the extrasynaptic and perisynaptic plasma membrane of Purkinje cell dendrites and spines throughout development. Quantitative analysis and three‐dimensional reconstructions further revealed a progressive developmental movement of the GABAB1 subunit on the surface of Purkinje cells from dendritic shafts to its final destination, the dendritic spines. Together, these results indicate that GABAB receptors undergo dynamic regulation during cerebellar development in association with the establishment and maturation of glutamatergic synapses to Purkinje cells.
Calcium permeability and flux through osmosensory transduction channels of isolated rat supraoptic nucleus neurons
Authors: Zhang Zizhen , Bourque Charles W.
Published: March 2006

Hypertonic stimuli delivered into the supraoptic nucleus provoke neuropeptide release from the somata of magnocellular neurosecretory cells (MNCs) in the presence of tetrodotoxin, suggesting that such stimuli can increase intracellular calcium concentration ([Ca2+]i) in the absence of action potentials. We therefore examined whether the stretch‐inhibited cation (SIC) channels of MNCs can mediate calcium influx. Whole‐cell recordings were made in MNCs isolated from the supraoptic nuclei of adult rats. Measurements of reversal potentials in different solutions revealed that the current induced by a suction‐evoked decrease in cell volume (ISIC) displays a selectivity sequence for monovalent cations of K+ > Cs+ > Na+ > NMDG+. The permeability of SIC channels to Ca2+, relative to Na+, was ∼ 5. In the presence of physiological concentrations of external Na+ and K+, the amplitude of inward ISIC was reduced dose‐dependently by external Ca2+ with an IC50 of 4.9 mm. This was not due to reduced suction‐evoked volume changes or to an accumulation of [Ca2+]i. Confocal imaging of cytoplasmic Calcium Green‐1 fluorescence revealed that activation of ISIC significantly increases [Ca2+]i in physiological solutions. This effect is absent in Ca2+‐free solution, or when Gd3+ (300 µm) is added to Ca2+‐containing solution. Part of this effect is inhibited in the presence of dantrolene (10 µm) and heparin (4 mg/mL), suggesting that release from intracellular Ca2+ stores participates in suction‐evoked Ca2+ signalling. These observations indicate that SIC channels are highly permeable to Ca2+, mediate significant Ca2+ entry and release of Ca2+ from internal stores under conditions when the volume of MNCs is decreased.
Mu‐opioid receptor cellular function in the nucleus accumbens is essential for hedonically driven eating
Authors: Ward Heather G. , Nicklous Danielle M. , Aloyo Vincent J. , Simansky Kenny J.
Published: March 2006

Acute pharmacological studies have implicated mu‐opioid receptors (MORs) in the shell of the nucleus accumbens (NAC) in mediating responses for palatable food and other natural and drug‐induced rewards. However, the long‐term behavioral effects of inactivating signal transduction via accumbal MORs, as quantified by an anatomically defined loss of cellular activity, have never been analysed. We combined microinfusion of the irreversible MOR antagonist, β‐funaltrexamine (β‐FNA; 8.0 nmol/0.8 µL,n = 9; controls,n = 6) with mapping by [35S]GTPγS autoradiography to demonstrate an anatomically specific loss of the coupling of MORs to their G‐proteins in the dorsal caudomedial shell of the NAC in rabbits. β‐FNA did not alter the stimulated coupling of kappa‐opioid receptors. This selective blockade of the cellular function of MORs persistently decreased consumption of a palatable sucrose solution by 40% during a daily 4‐h test conducted 2, 3 and 4 days after infusion. β‐FNA did not alter body weight or 20‐h consumption of standard chow or water. In 10 different rabbits, infusion of the selective, competitive MOR antagonist, CTAP (D‐Phe‐Cys‐Tyr‐D‐Trp‐Arg‐Thr‐Pen‐Thr‐NH2) into the same locus produced a reversible decrease in sucrose consumption, with normal intakes returning on the next day. Together, these data appear to establish that MORs in this accumbal subregion support responding for orosensory reward. Overall, these results visualize a discrete brain locus where cellular actions of endogenous opioids mediate behaviors involved in self‐administration of foods and perhaps other hedonically valued substances, such as ethanol and drugs of abuse.
Brain regions underlying response inhibition and interference monitoring and suppression
Authors: Blasi Giuseppe , Goldberg Terry E. , Weickert Thomas , Das Saumitra , Kohn Philip , Zoltick Brad , Bertolino Alessandro , Callicott Joseph H. , Weinberger Daniel R. , Mattay Venkata S.
Published: March 2006

Response inhibition and interference monitoring and suppression are two important aspects of cognitive control. Previous functional imaging studies have suggested a common network of brain regions underlying these cognitive processes; the dorsolateral prefrontal cortex (DLPFC), the ventrolateral prefrontal cortex (VLPFC), the dorsal cingulate (dACC), and the parietal cortex (PC). The relative contribution of these regions to these cognitive subprocesses, however, has not been determined. Based on previous findings supporting a role for dACC in the monitoring of conflicting information within a stimulus, we hypothesized greater activity in this cortical region during interference monitoring and suppression relative to response inhibition. On the other hand, as response inhibition is characterized by differential cognitive processes such as control implementation, top down modulation of the response, expectancy, and inhibition of behavioural response, we hypothesized increased activity in the other cortical nodes of the cognitive control network relative to interference monitoring and suppression. To this end, we conducted an event‐related functional magnetic resonance imaging (fMRI) study in 57 healthy volunteers using a task preferentially involving either interference monitoring and suppression or response inhibition. Accuracy for response inhibition was lower than for interference monitoring and suppression. Imaging data showed activation in DLPFC, dACC, VLPFC, PC for both conditions. Comparisons between the two conditions indicated greater activation bilaterally in DLPFC, VLPFC and PC during response inhibition, and greater activation in the dACC during interference monitoring and suppression. These results extend previous findings by suggesting regional functional specialization within a cortical network supporting cognitive control.
Secretion of brain‐derived neurotrophic factor from brain microvascular endothelial cells
Authors: Wang Hong , Ward Nicole , Boswell Mark , Katz David M.
Published: March 2006

The cerebral microvasculature has recently been identified as a source of factors that can influence the generation and survival of neurons, including brain‐derived neurotrophic factor (BDNF). However, relatively little is known about signals that regulate secretion of endothelial cell derived BDNF. To approach this issue the present study examined BDNF secretion from brain endothelial cells in response to reduced oxygen availability (hypoxia), using the mouse brain microvascular endothelial cell line, bEnd.3. We found that exposure of bEnd.3 cells to either sustained or intermittent hypoxia (IH) stimulates BDNF expression and release and that IH is the more potent stimulus. IH‐induced BDNF release can be partially inhibited by either N‐acetyl‐l‐cysteine, a scavenger of reactive oxygen species, or by the stable superoxide dismutase mimetic manganese(III)tetrakis1‐methyl‐4‐pyridylporphyrin, indicating that oxyradical formation contributes to enhanced secretion of BDNF. In addition, we found that IH‐induced BDNF release requires Ca2+ mobilization from internal stores through ryanodine‐ and inositol (1,4,5‐triphosphate) IP3 receptors and is completely blocked by SKF 96365, a nonselective inhibitor of transient receptor potential (TRP) channels. These data demonstrate that bEnd.3 cells respond to oxidative stress by increasing BDNF secretion and, in addition, highlight TRP channels as potential therapeutic targets for enhancing BDNF availability from the cerebral microvasculature.
Diacylglycerol kinase ζ is involved in the process of cerebral infarction
Authors: Nakano Tomoyuki , Hozumi Yasukazu , Ali Hasmat , Saino‐Saito Sachiko , Kamii Hideyuki , Sato Shinya , Kayama Takamasa , Watanabe Masahiko , Kondo Hisatake , Goto Kaoru
Published: March 2006

Diacylglycerol kinase (DGK) is an enzyme that phosphorylates a second messenger diacylglycerol (DG) and is involved in a variety of pathophysiological cellular responses. We have previously reported that DGKζ may be involved in the selective vulnerability of hippocampal CA1 neurons in transient forebrain ischemia. In this study we aimed to further elucidate functional implications of DGK isozymes in the cerebral cortex suffering from infarction using a focal ischemic model. In the early phase of 90 min of middle cerebral artery occlusion, DGKζ‐immunoreactivity is reduced rapidly in the nucleus of cortical neurons in the ischemic core, while DGKι and other neuronal proteins such as MAP‐2 and NeuN remain intact. This suggests that rapid disappearance of DGKζ in ischemic neurons is a quite early event precedent to neuronal degeneration in response to ischemia. Furthermore, in the late inflammatory phase of infarction DGKζ‐immunoreactivity is detected in non‐neuronal cells including factor VIII‐positive endothelial cells and ED‐1‐positive phagocytic cells. The present study suggests that DGKζ may play roles in various processes of ischemic brain damage including neuronal death and non‐neuronal inflammatory response.
Reduced hippocampal neurogenesis and number of hilar neurones in streptozotocin‐induced diabetic mice: reversion by antidepressant treatment
Authors: Beauquis Juan , Roig Paulina , Homo‐Delarche Françoise , De Nicola Alejandro , Saravia Flavia
Published: March 2006

Cerebral dysfunctions, including a high incidence of depression, are common findings in human type 1 diabetes mellitus. An association between depression and defective hippocampal neurogenesis has been proposed and, in rodents, antidepressant therapy restores neuronal proliferation in the dentate gyrus. Hippocampal neurogenesis is also deficient in diabetic mice, which led us to study whether the selective serotonin reuptake inhibitor fluoxetine influences cell proliferation in streptozotocin‐diabetic animals. Diabetic and control C57BL/6 mice received fluoxetine (10 mg/kg/day, i.p., 10 days) and dentate gyrus cell proliferation was measured after a single injection of 5‐bromo‐2′‐deoxyuridine (BrdU). Diabetic mice showed reduced cell proliferation. Fluoxetine treatment, although having no effect in controls, corrected this parameter in diabetic mice. The phenotype of newly generated cells was analysed by confocal microscopy after seven daily BrdU injections, using Tuj‐1/β‐III tubulin as a marker for immature neurones and glial fibrillary acidic protein for astrocytes. In controls, the proportion of Tuj‐1‐BrdU‐positive cells over total BrdU cells was ∼70%. In vehicle‐treated diabetic mice, immature neurones decreased to 56% and fluoxetine brought this proportion back to control values without affecting astrocytes. Therefore, fluoxetine preferentially increased the proliferation of cells with a neuronal phenotype. In addition, neurones were counted in the hilus of the dentate gyrus; a 30% decrease was found in diabetic mice compared with controls, whereas this neuronal loss was prevented by fluoxetine. In conclusion, fluoxetine treatment restored neuroplasticity‐related hippocampal alterations of diabetic mice. These findings may be potentially important to counteract diabetes‐associated depression in humans.
FGF‐2 deficiency does not alter vulnerability of the dopaminergic nigrostriatal system towards MPTP intoxication in mice
Authors: Zechel S. , Jarosik J. , Kiprianova I. , Schober A. , Unsicker K. , von Bohlen und Halbach O.
Published: March 2006

Fibroblast growth factor 2 (FGF‐2) was the first growth factor discovered that exerted prominent protective and regenerative effects in an animal model of Parkinson's disease, the MPTP‐lesioned dopaminergic nigrostriatal system. To address the putative physiological relevance of endogenous FGF‐2 for midbrain dopaminergic neurons, we have analysed densities of tyrosine hydroxylase (TH)‐positive cells in the substantia nigra (SN) and TH‐positive fibers in the striatum and amygdala of adult FGF‐2‐deficient mice. We found that densities of TH‐immunoreactive (ir) cells in the SN as well as densities of TH‐ir fibers in the striatum and amygdala were unaltered as compared with wild‐type littermates. There is evidence to suggest that growth factor deficits do not become apparent unless a system is challenged in a lesioning paradigm. We therefore tested the ability of the nigrostriatal system with respect to its ability to cope with MPTP (1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine) intoxication. Treatment with 20 mg/kg MPTP on three consecutive days reduced dopamine levels in the striatum by about 80%. Densities of TH‐positive neurons in the SN were reduced by 71%. However, both parameters did not significantly differ between FGF‐2(–/–) mice and wild‐type littermates. Our results therefore suggest that FGF‐2, despite its prominent pharmacological potency as a neurotrophic factor for the dopaminergic nigrostriatal system, is not crucial for maintaining its structural integrity and ability to cope with MPTP intoxication.
Experimental support of the scaling rule for demographic stochasticity
Authors: Desharnais Robert A. , Costantino R. F. , Cushing J. M. , Henson Shandelle M. , Dennis Brian , King Aaron A.
Published: March 2006

A scaling rule of ecological theory, accepted but lacking experimental confirmation, is that the magnitude of fluctuations in population densities due to demographic stochasticity scales inversely with the square root of population numbers. This supposition is based on analyses of models exhibiting exponential growth or stable equilibria. Using two quantitative measures, we extend the scaling rule to situations in which population densities fluctuate due to nonlinear deterministic dynamics. These measures are applied to populations of the flour beetleTribolium castaneumthat display chaotic dynamics in both 20‐g and 60‐g habitats. Populations cultured in the larger habitat exhibit a clarification of the deterministic dynamics, which follows the inverse square root rule. Lattice effects, a deterministic phenomenon caused by the discrete nature of individuals, can cause deviations from the scaling rule when population numbers are small. The scaling rule is robust to the probability distribution used to model demographic variation among individuals.
Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests
Authors: Muller‐Landau Helene C. , Condit Richard S. , Chave Jerome , Thomas Sean C. , Bohlman Stephanie A. , Bunyavejchewin Sarayudh , Davies Stuart , Foster Robin , Gunatilleke Savitri , Gunatilleke Nimal , Harms Kyle E. , Hart Terese , Hubbell Stephen P. , Itoh Akira , Kassim Abd Rahman , LaFrankie James V. , Lee Hua Seng , Losos Elizabeth , Makana Jean‐Remy , Ohkubo Tatsuhiro , Sukumar Raman , Sun I‐Fang , Nur Supardi M. N. , Tan Sylvester , Thompson Jill , Valencia Renato , Muñoz Gorky Villa , Wills Christopher , Yamakura Takuo , Chuyong George , Dattaraja Handanakere Shivaramaiah , Esufali Shameema , Hall Pamela , Hernandez Consuelo , Kenfack David , Kiratiprayoon Somboon , Suresh Hebbalalu S. , Thomas Duncan , Vallejo Martha Isabel , Ashton Peter
Published: March 2006

The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into the global carbon budget, and deserves careful assessment. We assembled data from 10 old‐growth tropical forests encompassing censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it, and were inconsistent with the predictions of metabolic ecology in all forests.
Plant pathogens drive density‐dependent seedling mortality in a tropical tree
Authors: Bell Thomas , Freckleton Robert P. , Lewis Owen T.
Published: March 2006

One explanation for the extraordinary diversity of tropical forest trees is that density‐dependent mortality from herbivores or pathogens puts locally rare species at an advantage. Density‐dependent mortality of seeds and small seedlings is particularly intense in tropical forests, but its causes remain uncertain. Here, we show experimentally that pathogens from the Oomycota are associated with intense mortality in seedlings of a neotropical tree, Sebastiana longicuspis. Seedlings in untreated plots experienced eight times higher mortality compared with seedlings in plots treated with fungicide. Mortality was strongly density dependent: in fungicide‐treated plots survival was unaffected by density, but survival in unsprayed plots was over three times higher at low density. Density‐dependent mortality observed in a simultaneous, non‐manipulative study was highly transient, suggesting that short‐term observational studies may underestimate the intensity and form of pathogen‐induced mortality. If such effects are widespread, plant pathogens may play a key role in maintaining and structuring tropical diversity.
Biosynthesis of hopanoids by sulfate‐reducing bacteria (genus Desulfovibrio)
Authors: Blumenberg Martin , Krüger Martin , Nauhaus Katja , Talbot Helen M. , Oppermann Birte I. , Seifert Richard , Pape Thomas , Michaelis Walter
Published: March 2006

Sulfate reduction accounts for about a half of the remineralization of organic carbon in anoxic marine shelf regions. Moreover, it was already a major microbial process in the very early ocean at least 2.4 billion years before the present. Here we demonstrate for the first time the capability of sulfate‐reducing bacteria (SRB) to biosynthesize hopanoids, compounds that are quantitatively important and widely distributed biomarkers in recent and fossil sediments dating back to the late Archean. We found high concentrations (9.8–12.3 mg per gram of dry cells) of non‐extended and extended bacteriohopanoids (bacteriohopanetetrol, aminobacteriohopanetriol, aminobacteriohopanetetrol) in pure cultures of SRB belonging to the widely distributed genus Desulfovibrio. Biohopanoids were found – considered as membrane rigidifiers – in more than 50% of bacterial species analysed so far. However, their biosynthesis appeared to be restricted to aerobes or facultative anaerobes with a very few recently described exceptions. Consequently, findings of sedimentary hopanoids are often used as indication for oxygenated settings. Nevertheless, our findings shed new light on the presence of hopanoids in specific anoxic settings and suggests that SRB are substantial sources of this quantitatively important lipid class in recent but also past anoxic environments.
Identification of a complete methane monooxygenase operon from soil by combining stable isotope probing and metagenomic analysis
Authors: Dumont Marc G. , Radajewski Stefan M. , Miguez Carlos B. , McDonald Ian R. , Murrell J. Colin
Published: March 2006

Stable isotope probing (SIP) allows the isolation of nucleic acids from targeted metabolically active organisms in environmental samples. In previous studies, DNA‐SIP has been performed with the one‐carbon growth substrates methane and methanol to study methylotrophic organisms. The methylotrophs that incorporated the labelled substrate were identified with polymerase chain reaction and sequencing of 16S rRNA and ‘functional genes’ for methanotrophs (mxaF, pmoA, mmoX). In this study, a SIP experiment was performed using a forest soil sample incubated with 13CH4, and the 13C‐DNA was purified and cloned into a bacterial artificial chromosome (BAC) plasmid. A library of 2300 clones was generated and most of the clones contained inserts between 10 and 30 kb. The library was probed for key methylotrophy genes and a 15.2 kb clone containing a pmoCAB operon, encoding particulate methane monooxygenase, was identified and sequenced. Analysis of the pmoA sequence suggested that the clone was most similar to that of a Methylocystis sp. previously detected in this forest soil. Twelve other open reading frames were identified on the clone, including the gene encoding beta‐ribofuranosylaminobenzene 5′‐phosphate synthase, which is involved in the biosynthesis of the ‘archaeal’ C1‐carrier, tetrahydromethanopterin, which is also found in methylotrophs. This study demonstrates that relatively large DNA fragments from uncultivated organisms can be readily isolated using DNA‐SIP, and cloned into a vector for metagenomic analysis.
Laparoscopic colonic surgery – mission accomplished or work in progress?
Authors: Kehlet H. , Kennedy R. H.
Published: March 2006

Laparoscopic colonic resection may facilitate early postoperative recovery due to reduced surgical stress, pain and ileus. However, large randomised studies have only shown marginal improvements in outcome compared with open surgery, reporting a median hospital stay of about 5–7 days. Concomitant with these developments multimodal rehabilitation, which involves a revision of general postoperative care principles, improved pain relief with epidural analgesia and early oral nutrition and mobilization, has demonstrated greater improvements in recovery after open surgery, resulting in a median hospital stay of about 2–4 days. Recent single centre, randomised studies where laparoscopic and open colonic resection are combined with multimodal rehabilitation have not resolved the debate regarding which is the optimal operative technique. Therefore, new strategies are required to integrate laparoscopy with multimodal rehabilitation in order to establish its advantages, cost effectiveness and indications in specific groups of patients or colorectal procedures, thus justifying widespread application of the laparoscopic technique.
Comparative myology of the forelimb of Liolaemus sand lizards (Liolaemidae)
Authors: Abdala Virginia , Moro Silvia
Published: March 2006

The lizard genus Liolaemus includes numerous constituent clusters of putatively related taxa, one of which is the Liolaemus boulengeri group, which in turn includes the sand lizards (of the Liolaemus wiegmannii subgroup). Members of the sand lizard group exhibit three different modes of burying into sand. The general morphology of the forelimb muscles of those Liolaemus species is analysed.

Herein, we present a study of the forelimb musculature of all species considered by Halloy et al. (1998). This study has three principal goals. First, we are seeking myological characters that will be useful in formulating phylogenetic hypothesis about the species of Liolaemus. With these characters, we also wish to compile morphological data that represent the morphological space implied in the diverse locomotor behaviours of these animals. Second, we are looking for derived features that reflect functional changes in the use of forelimb. Third, we wish to provide a cladistic analysis that can be used to test phylogenetic hypothesis derived from other sources of data. We present 48 characters in a data set and analyse it cladistically. We obtained a hypothesis of relationships of the Liolaemus species and compared this with previous hypotheses based on other characters. The trees obtained are not congruent with previously proposed phylogenies. We were unable to identify in our trees nodes that are based on structures reflecting functional changes in the use of the forelimb. The morphological similarities in the forelimb musculature of all species analysed seems to conform a very conservative general anatomical pattern with which Liolaemus sand lizards perform most of their locomotor behaviours.
Taxonomy and distribution of the hydrozoan and protozoan epibionts on Pagurus bernhardus (Linnaeus, 1758) (Crustacea, Decapoda) from Scotland
Authors: Fernandez‐Leborans Gregorio , Gabilondo Regina
Published: March 2006

Protozoan and hydrozoan epibionts on the hermit crab Pagurus bernhardus and its shell, collected near Cumbrae Island (Scotland) were studied. The epibionts found were the following: (1) protozoans: the suctorian ciliates Ephelota plana, Acineta compressa, Conchacineta constricta, Corynophrya anisostyla; the peritrich ciliates Cothurnia mobiusi and Zoothamnium plumula; the chonotrich ciliate Chilodochona quennerstedti; and (2) hydrozoans: the species Leuckartiara sp. and Clytia sp. The morphological characteristics of the epibionts were analysed, as well as their taxonomic position. The distribution of epibionts on the crab surface and its shell was studied, and the density and biomass of epibionts were calculated on each anatomic unit. There was a differential distribution according to the type of epibiont: hydrozoans dominated in biovolume and were present mainly on the shell, meanwhile protozoans represented the highest fraction of density and they were found exclusively on the crab (principally on eyes, antennulae, antennae, maxillipeds, pereopods and uropods). The anterior area of the cephalothorax was the most colonized. On this area, the maxillipeds and second pereopods showed the highest densities. The location of each epibiont species was described. There was a correlation between the length of the crab and the total number of hydrozoans. There was a significant correlation between the right and the left units of the crab, taking into consideration the mean densities of epibionts on each anatomical unit. The shell was colonized by the same species of hydrozoa that appeared on the crab, although in a much higher density (mean 3024.38 per shell; 6.9 per crab). There was a significant difference between both species of hydrozoan epibionts with respect to the mean densities on the different areas of the shell. The zone of the shell more occupied by Clytia sp. was the apical zone of the shell, while the highest densities of Leuckartiara sp. were registered near the aperture of the shell. The hydrozoan and protozoan epibiont species found on P. bernhardus in this study represent the first mention of their presence on this hermit crab.
Brood care among basommatophorans: a unique reproductive strategy in the freshwater limpet snailProtancylus(Heterobranchia: Protancylidae), endemic to ancient lakes on Sulawesi, Indonesia
Authors: Albrecht Christian , Glaubrecht Matthias
Published: March 2006

In molluscan taxa inhabiting marine environments oviparity and reproduction via planktonic larvae is predominant while incubation and viviparity is most frequently found in taxa inhabiting brackish or freshwater aquatic habitats. Brooding has evolved repeatedly and independently in several limnic taxa among Bivalvia and Gastropoda. However, among basommatophoran gastropods no such cases were yet known. We here report on a unique reproductive strategy involving brood care in the lacustrine freshwater limpet genusProtancylus, endemic to the ancient lakes on central Sulawesi (former Celebes), Indonesia, namely the Lake Poso and the Malili lake system, because this constitutes the first known case of this behaviour among the Basommatophora.Protancyluslive exclusively as epizoans on those pachychilid gastropods of the viviparous genusTylomelania, also a Sulawesi endemic species, that inhabit mostly soft substrates. We found that the two known speciesProtancylus pileolusfrom Lake Poso andP. adhaerensfrom the Malili lake system both retain gelatinous egg strings underneath their outer mantle, where up to 15 (mostly eight or nine) shelled juveniles are brooded. Nourishment is provided within the egg capsule only. Thus, brood care inProtancylusresembles the reproductive strategy found recently among pachychilid gastropodsJagorafrom the Philippines, but differs from euviviparous (i.e. matrotrophic) incubation among thiarid gastropods possessing a brood pouch with juveniles being nourished via a ‘pseudoplacenta’ in several taxa.
‘What she says she needs doesn’t make a lot of sense’: seeing and knowing in a field study of home‐care case management
Authors: Ceci Christine
Published: March 2006

Abstract  Foucault's preoccupation with the visual, specifically his positing of a sort of ‘positive unconscious of vision’, offers an entry point for examining data generated through a field study of home‐care case management practice. In Foucault's work, our attention is directed not so much to what is seen but to what can be seen and to the effects of practices of knowledge and power in constituting these particular realities. Knowledge emerges as a matter of what it is possible for knowers, for nurses, to see and to say, as well as the conditions that constitute these specific possibilities for seeing and saying in a given context. Given the significance of practices of seeing in case management – seeing clients, seeing situations – examining how possibilities for understanding are constituted through ways of seeing helps us to ‘see’ the limits of currently possible practice. In the case examined in this paper, these limits constitute a gap between what a client may actually need and what it is possible, in the context of current practice, to provide. To change practice it seems important, if only as a first step, to recognize the constraints of thought in what we see.
Whiteness and difference in nursing
Authors: Allen David G.
Published: March 2006

Abstract  This paper uses a semiotic, performative theory of language and post‐colonial theory to argue that nursing's representations of ‘multiculturalism’ need to be grounded in a theory of whiteness, an historicized understanding of how ethnic/cultural differences come to be represented in the ways they are and informed by Foucault's notions of power/knowledge. Using nursing education and ‘cultural compentency’ as examples, the paper draws on a range of literatures to suggest more critical and politically productive ways of approaching difference from within nursing's largely white interpretive framework.