bluuebunny/crossref_metadata_2025 huggingface dataset:
Malnutrition and hypermetabolism are not risk factors for the presence of hepatic encephalopathy: A cross‐sectional study
Authors: Sörös Peter , Böttcher Joachim , Weissenborn Karin , Selberg Oliver , Müller Manfred J
Published: November 2007

Background and Aim:  Hepatic encephalopathy is a frequent complication of cirrhosis. The present retrospective investigation was conducted to characterize metabolic alterations in cirrhotic patients with and without hepatic encephalopathy. We tested the hypothesis that reduced nutritional status or the degree of tissue catabolism are associated with the presence of hepatic encephalopathy.

Methods:  We investigated 223 patients with histologically confirmed nonalcoholic cirrhosis without hepatic encephalopathy and with hepatic encephalopathy (grades 1–3). To assess liver function, nutritional status, and energy metabolism, a variety of biochemical and clinical tests were performed including anthropometric measurements, bioelectrical impedance analysis, and indirect calorimetry.

Results:  Nutritional status and tissue catabolism were not significantly different between patients with and without hepatic encephalopathy.

Conclusions:  Our data do not support the hypothesis that malnutrition or tissue catabolism are independent risk factors for the presence of hepatic encephalopathy in patients with nonalcoholic cirrhosis.
Maintaining patient hopefulness: a critique
Authors: Lipscomb Martin
Published: November 2007

It has been proposed that maintaining patient hopefulness is or should be a central nursing duty, and within the nursing literature the maintenance of patient and family hope is generally presented as an unproblematic ‘good thing’. However, here it is argued that hope cannot bear the claims made on its behalf. The concept is variously interpreted and this variation might indicate that hope cannot sustain a real or technical definition. Further, hope may be confused or entangled with teleological assumptions, and this complicates use of the concept in healthcare systems which prize scientific forms of evidence‐informed decision‐making. As currently understood hope cannot be situated within a sustainable scientific theory and nurses are therefore advised to distance themselves from the more extravagant claims that are made regarding the concept.
Development of the New Zealand nursing workforce: historical themes and current challenges
Authors: Gage Jeffrey D. , Hornblow Andrew R.
Published: November 2007

Development of the New Zealand nursing workforce has been shaped by social, political, scientific and interprofessional forces. The unregulated, independent and often untrained nurses of the early colonial period were succeeded in the early 1900s by registered nurses, with hospital‐based training, working in a subordinate role to medical practitioners. In the mid/late 1900s, greater specialisation within an expanding workforce, restructuring of nursing education, health sector reform, and changing social and political expectations again reshaped nursing practice. Nursing now has areas of increasing autonomy, expanding opportunities for postgraduate education and leadership roles, and a relationship with medicine, which is more collaborative than in the past. Three current challenges are identified for nursing in New Zealand's rapidly evolving health sector; development of a nursing‐focused knowledge culture, strengthening of research capacity, and dissemination of new nursing knowledge.
A historical description of the tensions in the development of modern nursing in nineteenth‐century Britain and their influence on contemporary debates about evidence and practice
Authors: Traynor Michael
Published: November 2007

Modern British nursing developed from the mid‐nineteenth century and was seen as a morally purifying activity and as a potential force for social cohesion. It was also considered an activity fit for women. However, it embodied a fundamental tension within Victorian sensibility between a kind of rationalistic utilitarianism and a faith in transcendent values. This paper explores this tension and suggests that it can be detected in current debates about practice and evidence in nursing in the contemporary context of a rise of managerialism in public services.
Withdrawal from Weihui: China missions and the silencing of missionary nursing, 1888–1947
Authors: Grypma Sonya
Published: November 2007

The shift of missionary nursing from the center to the margins of nursing practice can be traced to the unceremonious closure of China as a mission field in the late 1940s. Building on a larger study of Canadian missionary nursing at the United Church of Canada North China Mission between 1888 and 1947, this paper traces Clara Preston's experiences during the last tumultuous days of the mission during the height of China's civil war. Drawing on rich data from the United Church of Canada/ Victoria University Archives, private family collections (photos, letters, memoirs) as well as from three on‐site visits to the Weihui Hospital in Henan, China, this paper focuses on the questions ‘what happened during the last days of Canadian missionary nursing in China?’ and ‘why is so little known about missionary nursing?’ According to this study, three issues contributed to the silencing of missionary nursing after 1947: the self‐censorship of repatriated missionaries, the mission identity crises catalyzed by the ‘failure’ of the missionary enterprise in China, and the equating of the missionary movement with colonialism and imperialism in academic discourse.
Relation between nitrogenase synthesis and activity in a marine unicellular diazotrophic strain, Gloeothece sp. 68DGA (Cyanophyte), grown under different light/dark regimens
Authors: Taniuchi Yukiko , Ohki Kaori
Published: November 2007

The relationship between the abundance of nitrogenase and its activity was studied in the marine unicellular cyanobacterium Gloeothece sp. 68DGA cultured under different light/dark regimens. The Fe‐ and MoFe‐protein of nitrogenase and nitrogen (N2)‐fixing (acetylene reduction) activity were detected only during the dark phase when the cells were grown under a 12 h light/12 h dark cycle (12L/12D). Nitrogenase activity appeared about 4 h after entering the dark phase. Maximum nitrogenase activity occurred at around the middle of the dark phase, and the activity rapidly decreased to zero before the start of the light phase. The rapid decrease of nitrogenase activity and the Fe‐protein of nitrogenase near the end of the dark phase in 12L/12D were partly recovered by the addition of l‐methionine‐sulfoximine, an inhibitor of glutamine synthetase. Diurnal oscillation of the abundance of nitrogenase was maintained in the first subjective dark phase (i.e. the period corresponding to the dark phase) after the cells were transferred from 12L/12D to continuous illumination. However, enzyme activity was detected only when photosynthetic oxygen (O2) evolution was completely suppressed by reducing the light intensity or by the addition of 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea. Nitrogenase always appeared in the cells about 16 h after starting the light phase, even when the 12L/12D cycle was modified by the addition or subtraction of a single 6 h period of light or dark. These results suggest the following: (i) N2‐fixation by Gloeothece sp. 68DGA is primarily regulated by an endogenous circadian oscillator at the level of nitrogenase synthesis. (ii) The endogenous circadian rhythm resets on a shift of the timing of the light phase. (iii) Nitrogenase activity is not always reflected in the presence of nitrogenase. (iv) The activity of nitrogenase is negatively regulated by fixed nitrogen and the concentration of ambient O2.
Grammephora peyssonnelioides gen. et sp. nov. (Rhodophyta, Rhodymeniaceae) from the Solomon Islands, South Pacific
Authors: N'Yeurt Antoine D. R. , Payri Claude E.
Published: November 2007

A new genus and species of red alga in the Rhodymeniaceae, Grammephora peyssonnelioides, is described from both shallow and deepwater habitats in the Solomon Islands, South Pacific. The new genus and species is characterized by prostrate overlapping lobes with a strongly cartilaginous flexible texture, distinct surface linear markings perpendicular to the growing margins, and a compact three to four celled medulla of relatively small refractive cells. Tetrasporangia are elongate and decussately divided, and occur in large scattered dorsal surface sori. Cystocarps are prominent and conical, on the dorsal surface of the blade, with a network of nutritive filaments and basal nutritive tissue around the suspended, centrally located carposporophyte, with all gonimoblast initials becoming carposporangia. The columnar fusion cell is uniquely crowned by a ring of discoid cells of nonalgal origin.
Research note: Irradiance of photosynthetically active radiation determines ultraviolet‐susceptibility of photosynthesis in Ulva lactuca L.(Chlorophyta)
Authors: Fredersdorf Jana , Bischof Kai
Published: November 2007

The respective ratio of photosynthetically active to ultraviolet radiation is of crucial importance to results obtained in ultraviolet (UV)‐research on photoautotrophic organisms. Specimens of the green macroalga Ulva lactuca L. were exposed to a constant irradiance of UV‐radiation at increasing irradiances of photosynthetically active radiation (PAR). The effects of experimental irradiance and spectral composition on photoinhibition of photosynthesis and its recovery were monitored by chlorophyll fluorescence measurements and the activity of the xanthophyll cycle was assessed by high performance liquid chromatography‐(HPLC) based pigment analysis. Results indicate a UV‐induced delay in recovery from PAR‐induced photoinhibition and a deceleration of violaxanthin conversion within the xanthophyll cycle due to the presence of UV‐radiation. Also the concentration of the protective pigment lutein increased considerably and could be indicative of the existence of an additional light‐protective mechanism, as, for example, the lutein‐epoxid cycle in Ulva. In total, results clearly show that the extent of UV‐induced inhibition of photosynthesis to be found in UV‐exposure experiments is highly dependent on the irradiance of background photosynthetically active radiation: with increasing irradiance of PAR the UV‐effects were diminished. Exemplified by the green algae Ulva lactuca this study demonstrates the crucial importance of the ratios of PAR:UV applied in UV‐research, particularly when conducting laboratory experiments in an ecological context.
Value of power Doppler sonography with 3D reconstruction in preoperative diagnostics of extraprostatic tumor extension in clinically localized prostate cancer
Authors: Zalesky Miroslav , Urban Michael , Smerhovský Zdenek , Zachoval Roman , Lukes Martin , Heracek Jiri
Published: November 2007

Aim:  The aim of the study is to investigate the value of preoperative power Doppler sonography with 3D reconstruction (3D‐PDS) for diagnostics of extraprostatic extension of prostate cancer.

Patients and Methods:  In the prospective study we examined 146 patients with clinically localized prostate cancer who underwent radical prostatectomy. Prior to surgery, each patient underwent 3D‐PDS, transrectal ultrasound (TRUS), and digital rectal examination (DRE). Furthermore, we determined the prostate volume, prostate specific antigen (PSA) level, PSA density (PSAD), and Gleason score. The risk of locally advanced cancer was assessed using Partin tables. We determined the sensitivity, specificity, and predictive values of these diagnostic procedures. We plotted the receiver operating characteristic (ROC) curves and calculated the areas under the curves (AUC). Multivariate logistic regression was used to identify the significant predictors of extraprostatic tumor extension. Based on this we developed diagnostic nomograms maximizing the probability of accurate diagnosis.

Results:  The significant differences between patients with organ confined and locally advanced tumor (based on the postoperative assessment) were observed in the PSA levels (P < 0.014), PSAD (P < 0.004), DRE (P < 0.037), TRUS (P < 0.003), and 3D‐PDS (P < 0.000). The highest AUC value of 0.776 (P < 0.000) was found for 3D‐PDS. The observed AUC value for TRUS was 0.670 (P < 0.000) and for PSAD 0.639 (P < 0.004). In multivariate regression analysis, the PSAD, preoperative Gleason score, and 3D‐PDS finding were identified as significant preoperative predictors of extraprostatic tumor extension.

Conclusion:  Our data suggest that the 3D‐PDS is a valuable preoperative diagnostic examination to identify locally advanced prostate cancer. Therefore, it can be used to maximize the probability of the accurate diagnosis of extraprostatic tumor extension.
Recovery of skilled reaching following motor cortex stroke: do residual corticofugal fibers mediate compensatory recovery?
Authors: Gharbawie Omar A. , Karl Jenni M. , Whishaw Ian Q.
Published: November 2007

Motor cortex (MC) injury impairs skilled reaching in rats, but success scores are eventually restored to approximate preoperative levels. The improvement is attributed to compensatory strategies, such as substituting trunk rotations for the chronically lost rotatory movement of the forelimb, that occur during transport and withdrawal. The present study examined the contributions of the rostral motor cortex (RMC) and the caudal motor cortex (CMC) to skilled reaching performance. The study also examined the role of the ipsilateral and the contralateral hemispheres in supporting the spontaneous recovery. Rats were trained to reach for single food pellets, and their recovery from partial or complete MC injury was documented with quantitative scores and movement element measures in three experiments: (1) devascularization of the CMC, or the RMC, or both, in the hemisphere contralateral to the reaching paw; (2) additional lesions to the CMC and RMC injuries such that the conjoint damage amounted to an MC lesion; and (3) MC lesion followed by damage in the neocortex lateral to the injury or in the opposite MC. The results showed that the CMC made the main contribution to skilled reaching performance, and that there was a lesser contribution by the RMC. MC damage was exacerbated by additional damage to the ipsilateral neocortex as compared to the contralateral neocortex. The results are discussed in relation to the idea that the involvement of the neocortical areas in skilled reaching performance and its recovery is proportional to the region from which corticospinal projections originate.
Phenotype of V2‐derived interneurons and their relationship to the axon guidance molecule EphA4 in the developing mouse spinal cord
Authors: Lundfald Line , Restrepo C. Ernesto , Butt Simon J. B. , Peng Chian‐Yu , Droho Steven , Endo Toshiaki , Zeilhofer Hanns Ulrich , Sharma Kamal , Kiehn Ole
Published: November 2007

The ventral spinal cord consists of interneuron groups arising from distinct, genetically defined, progenitor domains along the dorsoventral axis. Many of these interneuron groups settle in the ventral spinal cord which, in mammals, contains the central pattern generator for locomotion. In order to better understand the locomotor networks, we have used different transgenic mice for anatomical characterization of one of these interneuron groups, called V2 interneurons. Neurons in this group are either V2a interneurons marked by the postmitotic expression of the transcription factor Chx10, or V2b interneurons which express the transcription factors Gata2 and Gata3. We found that all V2a and most V2b interneurons were ipsilaterally projecting in embryos as well as in newborns. V2a interneurons were for the most part glutamatergic while V2b interneurons were mainly GABAergic or glycinergic. Furthermore, we demonstrated that a large proportion of V2 interneurons expressed the axon guidance molecule EphA4, a molecule previously shown to be important for correct organization of locomotor networks. We also showed that V2 interneurons and motor neurons alone did not account for all EphA4‐expressing neurons in the spinal cord. Together, these findings enable a better interpretation of neural networks underlying locomotion, and open up the search for as yet unknown components of the mammalian central pattern generator.
Heterogeneity of V2‐derived interneurons in the adult mouse spinal cord
Authors: Al‐Mosawie A. , Wilson J. M. , Brownstone R. M.
Published: November 2007

Spinal neurons and networks that generate rhythmic locomotor activity remain incompletely defined, prompting the use of molecular biological strategies to label populations of neurons in the postnatal mouse. During spinal cord development, expression of Lhx3 in the absence of Isl1 specifies a V2 interneuronal fate. In this study, postnatal V2‐derived interneurons were identified by yellow fluorescent protein (YFP) expression in the double‐transgenic offspring of Lhx3Cre/+ × thy1‐loxP‐stop‐loxP‐YFP mice. While some motoneurons were labelled, several populations of interneurons predominantly located in lamina VII could also be distinguished. Small interneurons were located throughout the spinal cord whereas larger interneurons were concentrated in the lumbar enlargement. Some V2‐derived interneurons were propriospinal, with axons that bifurcated in the lateral funiculus. V2‐derived interneurons gave rise to populations of both excitatory and inhibitory interneurons in approximately equal proportions, as demonstrated by in situ hybridization with VGLUT2 mRNA. Immunohistochemical studies revealed YFP+ boutons throughout the spinal cord. Both glutamatergic and glycinergic YFP+ boutons were observed in lamina IX where many apposed motoneuron somata. GABAergic YFP+ boutons were also observed in lamina IX, and they did not form P‐boutons. At P0, more than half of the YFP+ interneurons expressed Chx10 and thus were derived from the V2a subclass. In adult mice, there was an increase in Fos expression in V2‐derived interneurons following locomotion, indicating that these neurons are active during this behaviour. The heterogeneity of V2‐derived interneurons in adult mice indicates that physiologically distinct subpopulations, including last‐order interneurons, arise from these embryonically defined neurons.
The prokineticin receptor agonist Bv8 increases GABA release in the periaqueductal grey and modifies RVM cell activities and thermoceptive reflexes in the rat
Authors: De Novellis Vito , Negri Lucia , Lattanzi Roberta , Rossi Francesca , Palazzo Enza , Marabese Ida , Giannini Elisa , Vita Daniela , Melchiorri Pietro , Maione Sabatino
Published: November 2007

The prokineticin Bv8, a small protein secreted by the skin of the Bombina variegata frog, is a potent agonist of both the identified prokineticin receptors, the G‐protein‐coupled PK‐R1 and PK‐R2. We found in this study that intraperiaqueductal grey (PAG) Bv8, 100 and 200 pmol per rat, exerted a pronociceptive action and caused opposite effects on the ongoing rostral ventromedial medulla (RVM) On‐ and Off‐cell activities in rats. Bv8 increased and decreased the ongoing activity of RVM On and Off cells, respectively. Bv8 decreased tail flick latency and increased the pause and shortened the onset of the Off‐cell pause. Bv8 did not change either the tail flick‐induced On‐cell burst of activity or the onset of On‐cell peak firing. Microdialysis analysis, applied in combination with the plantar test, showed that intra‐PAG perfusion with Bv8 (0.25 and 0.5 pm) increased GABA, but not glutamate, extracellular levels, and decreased thermoceptive thresholds. These findings show that stimulation of PAG PK‐Rs might worsen pain perception and this effect is consistent with both RVM On‐ and Off‐cell ongoing and tail flick‐related activities, as well as with the increase induced by Bv8 in PAG GABA levels.
Disruption of dopamine homeostasis underlies selective neurodegeneration mediated by α‐synuclein
Authors: Park Soon S. , Schulz Emily M. , Lee Daewoo
Published: November 2007

A key challenge in Parkinson's disease research is to understand mechanisms underlying selective degeneration of dopaminergic neurons mediated by genetic factors such as α‐synuclein (α‐Syn). The present study examined whether dopamine (DA)‐dependent oxidative stress underlies α‐Syn‐mediated neurodegeneration using Drosophila primary neuronal cultures. Green fluorescent protein (GFP) was used to identify live dopaminergic neurons in primary cultures prepared on a marked photoetched coverslip, which allowed us to repeatedly access preidentified dopaminergic neurons at different time points in a non‐invasive manner. This live tracking of GFP‐marked dopaminergic neurons revealed age‐dependent neurodegeneration mediated by a mutant human α‐Syn (A30P). Degeneration was rescued when α‐Syn neuronal cultures were incubated with 1 mm glutathione from Day 3 after culturing. Furthermore, depletion of cytoplasmic DA by 100 µmα‐methyl‐p‐tyrosine completely rescued the early stage of α‐Syn‐mediated dopaminergic cell loss, demonstrating that DA plays a major role in oxidative stress‐dependent neurodegeneration mediated by α‐Syn. In contrast, overexpression of a Drosophila tyrosine hydroxylase gene (dTH1) alone caused DA neurodegeneration by enhanced DA synthesis in the cytoplasm. Age‐dependent dopaminergic cell loss was comparable in α‐Syn vs dTH1‐overexpressed neuronal cultures, indicating that increased DA levels in the cytoplasm is a critical change downstream of mutant α‐Syn function. Finally, overexpression of a Drosophila vesicular monoamine transporter rescued α‐Syn‐mediated neurodegeneration through enhanced sequestration of cytoplasmic DA into synaptic vesicles, further indicating that a main cause of selective neurodegeneration is α‐Syn‐induced disruption of DA homeostasis. All of these results demonstrate that elevated cytoplasmic DA is a main factor underlying the early stage of α‐Syn‐mediated neurodegeneration.
Aggregate formation of mutant protein kinase C gamma found in spinocerebellar ataxia type 14 impairs ubiquitin‐proteasome system and induces endoplasmic reticulum stress
Authors: Seki Takahiro , Takahashi Hideyuki , Adachi Naoko , Abe Nana , Shimahara Takayuki , Saito Naoaki , Sakai Norio
Published: November 2007

Several causal missense mutations in protein kinase Cγ (γPKC) gene have been found in spinocerebellar ataxia type 14 (SCA14), an autosomal dominant neurodegenerative disease. We previously demonstrated that mutant γPKC found in SCA14 is susceptible to two types of aggregation, cytoplasmic dot‐like and perinuclear massive aggregation, and causes cell death in Chinese hamster ovary cells. Long‐term time‐lapse imaging revealed that firstly accumulated dot‐like aggregation of mutant γPKC‐green fluorescent protein (GFP) gradually formed perinuclear massive aggregations, followed by cell death. However, it remains unclear how aggregate formation of mutant γPKC causes cell death. In the present study, we examined whether these mutant aggregations affect the ubiquitin‐proteasome system (UPS) and endoplasmic reticular (ER) stress. Two mutant γPKC‐GFPs (S119P and G128D) were strongly ubiquitinated, and dot‐like aggregations of these mutants were ubiquitin‐positive and colocalized with proteasome 20S. Furthermore, proteasome activity in cells with aggregates, especially massive ones, was significantly decreased. Aggregate formation of mutant γPKC‐GFP induced phosphorylation of PERK (PKR‐like ER kinase) and nuclear expression of CHOP (C/EBP homologous protein), hallmarks of ER stress and subsequently activated caspase‐3. These results indicate that aggregate formation of mutant γPKC found in SCA14 impairs UPS and induces ER stress, leading to apoptotic cell death.
Activation of protease‐activated receptors in astrocytes evokes a novel neuroprotective pathway through release of chemokines of the growth‐regulated oncogene/cytokine‐induced neutrophil chemoattractant family
Authors: Wang Yingfei , Luo Weibo , Reiser Georg
Published: November 2007

Activation of protease‐activated receptors (PARs) is known to exert neuroprotection when low concentrations of the agonist protease thrombin are applied. However, the mechanism of protection is still unclear. Here, we showed that activation of multiple PARs, including PAR‐1, PAR‐2 and PAR‐4, was able to elevate the release of the chemokine cytokine‐induced neutrophil chemoattractant (CINC)‐3 from rat astrocytes, in addition to evoking CINC‐1 secretion. Different molecular mechanisms were identified as being involved in the secretion of CINC‐1 and CINC‐3, upon activation of different PARs. Importantly, we found that both CINC‐1 and CINC‐3 could signal to rat cortical neurons. Both chemokines acted via CXCR2 to prevent C2‐ceramide‐induced cytochrome c release from mitochondria. Consequently CINC‐1 and CINC‐3 protected neurons from apoptosis. We further revealed that conditioned media obtained from PAR‐activated astrocytes similarly protected cortical neurons against C2‐ceramide‐induced cell death. The neuroprotection was considerably suppressed by a CXCR2 antagonist. CXCR2 is the cognate receptor for CINC. Therefore, our findings demonstrate that PAR‐activated astrocytes are able to protect neurons against neurodegeneration and cell death via regulation of the secretion of chemokines CINC‐1 and CINC‐3. These data indicate a previously unknown mechanism for astrocyte‐mediated neuroprotection achieved by PAR activation.
Enhanced markers of oxidative stress, altered antioxidants and NADPH‐oxidase activation in brains from Fragile X mental retardation 1‐deficient mice, a pathological model for Fragile X syndrome
Authors: El Bekay Rajaa , Romero‐Zerbo Yanina , Decara Juan , Sanchez‐Salido Lourdes , Del Arco‐Herrera Ignacio , Rodríguez‐de Fonseca Fernando , De Diego‐Otero Yolanda
Published: November 2007

Fragile X syndrome is the most common form of inherited mental retardation in humans. It originates from the loss of expression of the Fragile X mental retardation 1 (FMR1) gene, which results in the absence of the Fragile X mental retardation protein. However, the biochemical mechanisms involved in the pathological phenotype are mostly unknown. The availability of the FMR1‐knockout mouse model offers an excellent model system in which to study the biochemical alterations related to brain abnormalities in the syndrome. We show for the first time that brains from Fmr1‐knockout mice, a validated model for the syndrome, display higher levels of reactive oxygen species, nicotinamide adenine dinucleotide phosphate (NADPH)‐oxidase activation, lipid peroxidation and protein oxidation than brains from wild‐type mice. Furthermore, the antioxidant system is deficient in Fmr1‐knockout mice, as shown by altered levels of components of the glutathione system. FMR1‐knockout mice lacking Fragile X mental retardation protein were compared with congenic FVB129 wild‐type controls. Our results support the hypothesis that the lack of Fragile X mental retardation protein function leads to a moderate increase of the oxidative stress status in the brain that may contribute to the pathophysiology of the Fragile X syndrome.
A potential role for bone morphogenetic protein signalling in glial cell fate determination following adult central nervous system injury in vivo
Authors: Hampton David W. , Asher Richard A. , Kondo Toru , Steeves John D. , Ramer Matt S. , Fawcett James W.
Published: November 2007

Bone morphogenetic proteins (BMPs) and their endogenous inhibitors, including noggin, chordin and follistatin, have roles in pattern formation and fate specification of neuronal and glial cells during nervous system development. We have examined their influence on glial reactions in the injured central nervous system (CNS). We show that penetrating injuries to the brain and spinal cord resulted in the upregulation of BMP‐2/4, BMP‐7, and noggin, with the latter being expressed almost exclusively by reactive astrocytes at the injury site, and we show that astrocytes in vitro produce noggin. As BMPs have been shown to drive cultured NG2‐positive oligodendrocyte precursors (OPCs) towards a multipotential phenotype (type II astrocytes), we investigated the effects of inhibiting noggin with a function‐blocking antibody (noggin‐FbAb). In vitro, BMP‐driven conversion of OPCs to type 2 astrocytes was inhibited by noggin, an effect that was reversed by noggin‐FbAb. Noggin‐FbAb also increased the number of type 2 astrocytes generated from cultured OPCs exposed to an astrocyte feeder layer, consistent with astrocytes producing both BMPs and noggin. In knife cut injuries in vivo, noggin‐FbAb treatment resulted in an increase in the number of NG2‐positive cells and small GFAP‐positive cells in the injury site, and the appearance of glial cells with the morphological and antigenic characteristics of type 2 astrocytes (as generated in vitro), with coexpression of both GFAP and NG2. This potential conversion of inhibitory OPCs to type 2 astrocyte‐like cells in vivo suggests that endogenous BMPs, unmasked by noggin antagonism, might be exploited to manipulate cell fate following CNS trauma.
An experimentally induced duplication of retinotopic mapping within the hamster primary visual cortex
Authors: Trevelyan Andrew J. , Upton A. L. , Cordery Patricia M. , Thompson Ian D.
Published: November 2007

Primary cortical areas normally have a single mapping of the receptor array arising from a ‘point‐to‐point’ projection from the thalamus. We show that, for the visual cortex, this simple mapping rule breaks down when retinal input to the thalamus is altered. We utilize the monocular enucleation paradigm, which alters subcortical mappings ipsilateral to the remaining eye. We show that this manipulation produces an altered visuotopic map in area 17 with two separated, mirror‐imaged representations of the central visual field. Furthermore, thalamic point‐to‐point connectivity is dramatically changed. There are now two overlapping geniculocortical projections: the predominant projection maps with apparently normal topography, and a second projection maps with the opposite polarity. The plane of symmetry of the duplicated anatomical projection coincides precisely with the functional map reversal and, notably, geniculocortical magnification factors are identical in the two projections. We suggest that the duplicated, abnormal geniculocortical projection is retinotopically matched to the normal projection. We speculate that aberrant geniculocortical terminals are stabilized because they have coherent activity patterns with topographically normal terminals.
Cannabinoid regulation in identified synapse of terrestrial snail
Authors: Lemak M.S. , Bravarenko N.I. , Bobrov M.Yu. , Bezuglov V.V. , Ierusalimsky V.N. , Storozhuk M.V. , Malyshev A.Y. , Balaban P.M.
Published: November 2007

In the terrestrial snail a direct monosynaptic glutamatergic connection between the primary sensory neuron and a premotor interneuron involved in withdrawal behaviour can be functionally identified using electrophysiological techniques. We investigated the involvement of cannabinoids in regulation of this synaptic contact. The results demonstrate that the specific binding sites for agonists to mammalian type 1 cannabinoid receptors (CB1Rs) exist in the snail's nervous system. Application of a synthetic cannabinoid agonist anandamide selectively changed the efficacy of synaptic contacts between the identified neurons. A decrease in the long‐term synaptic facilitation of the synaptic contact elicited by high‐frequency nerve tetanization in the presence of cannabinoid agonist anandamide was observed, suggesting a possible role of endocannabinoids in regulation of plasticity at this synaptic site. The selective antagonist of CB1Rs [N‐(piperidin‐1‐yl)‐5‐(4‐iodophenyl)‐1‐(2,4‐dichlorophenyl)‐4‐methyl‐1H‐pyrazole‐3‐carboxamide] AM251 bath application was changing the efficacy of the synaptic contact only when the postsynaptic neuron had been intracellularly activated before its application. This observation implies an involvement of endocannabinoids in plasticity phenomena induced by activity in the postsynaptic target. Additional support of endocannabinoid involvement in synaptic function at this site was given by experiments in which AM251 blocked the short‐term suppression of synaptic excitation evoked by low‐frequency nerve tetanization, a phenomenon qualitatively similar to cannabinoid‐dependent synaptically evoked suppression of excitation demonstrated in the mammalian nervous system. The results of the present study suggest an involvement of cannabinoids in the regulation of synaptic efficacy. Further, anandamide could be a candidate for an endogenous neuromessenger involved in plasticity processes.
Multiple nutrients limit litterfall and decomposition in a tropical forest
Authors: Kaspari Michael , Garcia Milton N. , Harms Kyle E. , Santana Mirna , Wright S. Joseph , Yavitt Joseph B.
Published: November 2007

To explore the importance of 12 elements in litter production and decomposition, we fertilized 36 1600 m2‐plots with combinations of N, P, K, or micronutrients (i.e. B, Ca, Cu, Fe, Mg, Mn, Mo, S, Zn) for 6 years in a lowland Panamanian forest. The 90% of litter falling as leaves and twigs failed to increase with fertilization, but reproductive litter (fruits and flowers) increased by 43% with N. K enhanced cellulose decomposition; one or more micronutrients enhanced leaf‐litter decomposition; P enhanced both. Our results suggest tropical forests are a non‐Liebig world of multiple nutrient limitations, with at least four elements shaping rates of litterfall and decomposition. Multiple metallomic enzymes and cofactors likely create gradients in the break down of leaf litter. Selection favours individuals that make more propagules, and even in an N‐rich forest, N is a non‐substitutable resource for reproduction.
Evolution of virulence: triggering host inflammation allows invading pathogens to exclude competitors
Authors: Brown Sam P. , Le Chat Ludovic , Taddei François
Published: November 2007

Virulence is generally considered to benefit parasites by enhancing resource‐transfer from host to pathogen. Here, we offer an alternative framework where virulent immune‐provoking behaviours and enhanced immune resistance are joint tactics of invading pathogens to eliminate resident competitors (transferring resources from resident to invading pathogen). The pathogen wins by creating a novel immunological challenge to which it is already adapted. We analyse a general ecological model of ‘proactive invasion’ where invaders not adapted to a local environment can succeed by changing it to one where they are better adapted than residents. However, the two‐trait nature of the ‘proactive’ strategy (provocation of, and adaptation to environmental change) presents an evolutionary conundrum, as neither trait alone is favoured in a homogenous host population. We show that this conundrum can be resolved by allowing for host heterogeneity. We relate our model to emerging empirical findings on immunological mediation of parasite competition.
Predictors for acute and chronic pouchitis following restorative proctocolectomy for ulcerative colitis
Authors: Abdelrazeq A. S. , Kandiyil N. , Botterill I. D. , Lund J. N. , Reynolds J. R. , Holdsworth P. J. , Leveson S. H.
Published: November 2007

Objective  This study was undertaken to evaluate the cumulative incidence, onset and risk predicting factors for acute and chronic pouchitis.

Method  A consecutive series of patients (n = 210), who underwent restorative proctocolectomy (RPC) and had a minimum follow‐up of 12 months was reviewed. The cumulative incidence and onset of pouchitis was determined. Univariate analysis, followed by logistic regression analysis was used to evaluate the association of various demographic, clinical and histopathologic variables with the subsequent development of acute and chronic pouchitis.

Results  A total of 198 patients were included. The mean follow‐up was 64 months (range, 12–180). Sixty‐four patients (32%) developed pouchitis, 35 acute and 29 chronic. The first episode of pouchitis occurred within the first year in 70% of cases. The presence of backwash ileitis (OR, 2.6; P = 0.015), primary sclerosing cholangitis (PSC; OR, 2; P = 0.018) and the duration of follow‐up (OR, 1.1; P = 0.043) were associated with a higher incidence of pouchitis. The duration of follow‐up was the only variable associated with acute pouchitis (P = 0.007). The presence of backwash ileitis and PSC were independent risk factors for chronic pouchitis (OR, 5.9; P < 0.001; OR, 2.8; P = 0.001 respectively).

Conclusion  Pouchitis is a heterogeneous disease which tends to occur early after restoration of gastrointestinal continuity. Patients with backwash ileitis and/or PSC are at considerable risk of developing chronic pouchitis. The strong association between backwash ileitis, PSC and chronic pouchitis suggests a common link in their pathogenesis.
Hereditary colorectal cancer: screen the parents (!)
Authors: Aryal K. R. , Perakath B. , Morton D. G.
Published: November 2007

Hereditary nonpolyposis colorectal cancer is the most common form of hereditary colorectal cancer. Occasionally, the presentation of colorectal cancer may be at an early age when parents may be unidentified obligate carriers. The risk of colorectal cancer increases with increasing age, even in inherited disease. Therefore, it is important to screen parents of patients presenting at a young age and to obtain a complete pedigree to identify and screen those who are at risk. Two such families where the index case presented at a young age were encountered in our practice and both their mothers were found to have colorectal cancer on surveillance colonoscopy. We recommend that parents of the index cases should be screened and more detailed family pedigree obtained when patients present at a young age with colorectal cancer.
Systematic reviews and meta‐analyses in coloproctology: interpretation and potential pitfalls
Authors: Wille‐Jørgensen P. , Renehan A. G.
Published: November 2007

A systematic review (SR) is the unbiased appraisal of systematically identified relevant studies. Implicit in its definition is a robust and scientifically valid process, and when performed as such, SR is an important clinical research tool and influence in health policy decision‐making. This educational paper outlines that, from the original prototype based on randomized trials, there are now many other types of SRs including those based on: nonrandomized comparative studies, observational studies, prognostic studies, and studies of diagnostic and screening tools. While each of these has a similar ‘anatomy’ or format, at an individual class level, there are principles specific to each SR type. Several examples from the coloproctology literature are used as case‐studies to illustrate potential pitfalls, and upon re‐analysis, often reverse or attenuate the conclusions stated in the original publication. These examples serve to emphasize the need for health professionals to understand the process of SR and meta‐analysis so that we all arrive at appropriate interpretations to the benefit of our patients.
Phylogeography and monophyly of the swordtail fish speciesXiphophorus birchmanni(Cyprinodontiformes, Poeciliidae)
Authors: Gutiérrez‐Rodríguez Carla , Shearer A. Eliot , Morris Molly R. , De Queiroz Kevin
Published: November 2007

We used sequences of the mitochondria control region to assess the distribution of genetic variation within and among populations of the poeciliid fish speciesXiphophorus birchmanni. We collected 122X. birchmannisamples from 11 sites in three drainage systems comprising the distribution of the species. We found low levels of polymorphism among aligned sequences and low levels of genetic variation within populations but high levels of genetic differentiation among populations. Haplotypes are exclusive to three river drainages (Los Hules, Calabozo and San Pedro). Mantel tests revealed correlations between geographical (both straight‐line and river distances) and genetic distance, consistent with an isolation by distance scenario, while nested clade analysis suggested allopatric fragmentation between haplotypes from two of the major drainages, and isolation by distance with restricted gene flow within those drainages. Finally, monophyly ofX. birchmanniis strongly supported while the previous hypothesis of the evolutionary origin of this species fromX. malincheis not.
What makes fisheries data informative?
Authors: Magnusson Arni , Hilborn Ray
Published: November 2007

Informative data in fisheries stock assessment are those that lead to accurate estimates of abundance and reference points. In practice, the accuracy of estimated abundance is unknown and it is often unclear which features of the data make them informative or uninformative. Neither is it obvious which model assumptions will improve estimation performance, given a particular data set. In this simulation study, 10 hypotheses are addressed using multiple scenarios, estimation models, and reference points. The simulated data scenarios all share the same biological and fleet characteristics, but vary in terms of the fishing history. The estimation models are based on a common statistical catch‐at‐age framework, but estimate different parameters and have different parts of the data available to them. Among the findings is that a ‘one‐way trip’ scenario, where harvest rate gradually increases while abundance decreases, proved no less informative than a contrasted catch history. Models that excluded either abundance index or catch at age performed surprisingly well, compared to models that included both data types. Natural mortality rate,M, was estimated with some reliability when age‐composition data were available from before major catches were removed. Stock‐recruitment steepness,h, was estimated with some reliability when abundance‐index or age‐composition data were available from years of very low abundance. Understanding what makes fisheries data informative or uninformative enables scientists to identify fisheries for which stock assessment models are likely to be biased or imprecise. Managers can also benefit from guidelines on how to distribute funding and manpower among different data collection programmes to gather the most information.
Food Standards Agency multidisciplinary workshop: children's food choice in the family setting
Authors: Stockley L. , Lund V. , Levy L.
Published: November 2007

Summary  There has been relatively little research on public health nutrition interventions for families and children, compared with, for example, work in schools. In Spring 2007, the UK Food Standards Agency held a multidisciplinary workshop on food choice in families and children, bringing together researchers from psychology, social sciences, public health and nutrition. The objectives of the workshop were to form an up‐to‐date view of the influences on children's and young people's food choice within the family, and identify future research needs. The participants identified six key areas for future research: multidisciplinary collaboration; using mixed research methods; developing new research methods; identifying family‐related diversity and tailoring interventions towards this; understanding the effects of different parenting styles and the relevance of these to implementing interventions; and developing a more sophisticated understanding of barriers and motivators to food‐related change in families.
Importance of vitamin D, calcium and exercise to bone health with specific reference to children and adolescents
Authors: Lanham‐New S. A. , Thompson R. L. , More J. , Brooke‐Wavell K. , Hunking P. , Medici E.
Published: November 2007

Summary  The optimisation of skeletal health during the life cycle is critical, especially if we are to reduce the continuing rise in osteoporosis – 1 in 2 women and 1 in 5 men over the age of 50 years will suffer an osteoporotic fracture. The foundations of adult bone health are laid down in the early years; therefore, optimisation of bone health in the young is fundamental. Although genetics play a major role, accounting for 70–75% of bone strength, other lifestyle and nutrition factors are known to be highly influential. Calcium (Ca) and vitamin D play critical roles in bone mineralisation as well as generally being key nutrients in health. All living cells require Ca to survive, with the majority (99%) of Ca being found in bones and teeth and the remainder in soft tissues and body fluids. Vitamin D is the generic term for two molecules: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). The former is derived by ultraviolet (UV) irradiation of ergosterol, which is distributed in plants and fungi. The latter is formed from the effect of UV irradiation on the skin. The principal role of vitamin D is to support the serum Ca concentration within narrow limits. Vitamin D is crucial for maximising gut absorption of calcium via vitamin D dependent Ca receptors. It is estimated that adequate vitamin D status increases Ca absorption to 30–40% of intake compared with only 10–15% absorption without adequate vitamin D. Intakes of Ca are a concern among certain groups of the population, for example a high proportion (>12%) of teenage boys and girls fail to meet the lower reference nutrient intake for Ca. For vitamin D, there are no dietary reference values for the age group 4–64 years as it is considered that UV exposure provides sufficient quantities of vitamin D, but there is now mounting evidence of widespread vitamin D insufficiency in the population. Weight‐bearing physical activity is beneficial to the skeleton but clarification is needed of the exact type, intensity and duration required for optimal bone mass. The role of othermicronutrients on bone metabolism remains to be fully quantified. This review investigates the current evidence of the impact of dietary and lifestyle factors on bone health, with specific reference to children and adolescents and with a focus on vitamin D, Ca and weight‐bearing exercise.
Agrobacterium‐mediated transformation of the temperate grass Brachypodium distachyon (genotype Bd21) for T‐DNA insertional mutagenesis
Authors: Vain Philippe , Worland Barbara , Thole Vera , McKenzie Neil , Alves Silvia C. , Opanowicz Magdalena , Fish Lesley J. , Bevan Michael W. , Snape John W.
Published: November 2007

Brachypodium distachyon is a promising model system for the structural and functional genomics of temperate grasses because of its physical, genetic and genome attributes. The sequencing of the inbred line Bd21 (http://www.brachypodium.org) started in 2007. However, a transformation method remains to be developed for the community standard line Bd21. In this article, a facile, efficient and rapid transformation system for Bd21 is described using Agrobacterium‐mediated transformation of compact embryogenic calli (CEC) derived from immature embryos. Key features of this system include: (i) the use of the green fluorescent protein (GFP) associated with hygromycin selection for rapid identification of transgenic calli and plants; (ii) the desiccation of CEC after inoculation with Agrobacterium; (iii) the utilization of Bd21 plants regenerated from tissue culture as a source of immature embryos; (iv) the control of the duration of the selection process; and (v) the supplementation of culture media with CuSO4 prior to and during the regeneration of transgenic plants. Approximately 17% of CEC produced transgenic plants, enabling the generation of hundreds of T‐DNA insertion lines per experiment. GFP expression was observed in primary transformed Bd21 plants (T0) and their progeny (T1). The Mendelian inheritance of the transgenes was confirmed. An adaptor‐anchor strategy was developed for efficient retrieval of flanking sequence tags (FSTs) of T‐DNA inserts, and the resulting sequences are available in public databases. The production of T‐DNA insertion lines and the retrieval of associated FSTs reported here for the reference inbred line Bd21 will facilitate large‐scale functional genomics research in this model system.