bluuebunny/crossref_metadata_2025 huggingface dataset:
Explaining Sub‐Saharan Africa's Manufacturing Performance
Authors: Lawrence Peter
Published: December 2005

This article surveys Africa's industrial, and especially manufacturing performance over the last four decades and reviews explanations for that performance which relate to issues of structure and class; structural adjustment policies; exports, technology, finance, and transactions costs. The article considers the extent to which manufacturing success is related to increasing exports and concludes with some consideration of future policy in the wake of the recently published report by the Commission for Africa. A strong role for the state is considered to be essential for successful growth in the future, both as substitute for a non‐existent domestic capitalist class, and as planner and director of manufacturing industrialization.
Bacitracin reveals a role for multiple thiol isomerases in platelet function
Authors: Robinson Aisling , O'Neill Sarah , Kiernan Aoife , O'Donoghue Niaobh , Moran Niamh
Published: December 2005

The platelet‐specific integrin αIIbβ3 has endogenous thiol isomerase activity associated with the CXXC motifs within the β subunit. Using a highly purified form of bacitracin, a thiol isomerase inhibitor, we now provide further evidence of the functional significance of this enzymatic activity in integrin activation. In addition, we demonstrate a role for multiple thiol isomerases in platelet function. This bacitracin prevented platelet aggregation to thrombin and collagen, and directly inhibited αIIbβ3 activation, as detected by PAC‐1 binding. In parallel, bacitracin inhibited the endogenous thiol isomerase activity of purified αIIbβ3 with a 50% inhibitory concentration of 15·5 μmol/l. In order to determine whether the effects of bacitracin are solely mediated by inhibition of integrin enzymatic activity, we examined integrin‐independent indices of platelet activation. We found bacitracin inhibited both platelet secretion (CD62P and CD63) and thromboxane (TxA2) production, with complete inhibition at different concentrations. Thus, we demonstrated a role for multiple thiol isomerases in platelet function. Taken together, these studies support a role for the endogenous integrin thiol isomerase activity in activation of αIIbβ3 and highlight the novel regulation of platelet function by other, as yet undefined thiol isomerases.
Role of prospective screening of blood for invasive aspergillosis by polymerase chain reaction in febrile neutropenic recipients of haematopoietic stem cell transplants and patients with acute leukaemia
Authors: Halliday Catriona , Hoile Rebecca , Sorrell Tania , James Greg , Yadav Satya , Shaw Peter , Bleakley Marie , Bradstock Ken , Chen Sharon
Published: December 2005

Guidelines for the use of polymerase chain reaction (PCR)‐based assays to aid the diagnosis of invasive aspergillosis (IA) in high‐risk haematology patients have not been formulated. We prospectively evaluated a nested PCR assay to detect Aspergillus in blood during 95 febrile neutropenic episodes, in patients with haematological malignancy and haematopoietic stem cell transplant (HSCT) recipients. PCR results were correlated with the diagnostic classification of the 2002 European Organisation for Research and Treatment of Cancer/Mycosis Study Group. When two‐positive results were used to define an episode as ‘PCR positive’, the sensitivity, specificity, positive‐predictive value and negative predictive value for ‘proven’/‘probable’ IA (n = 13) were 100%, 75·4%, 46·4% and 100%, respectively. Consecutive positive results occurred in 61·5% of these 13 episodes. Overall, PCR positivity preceded standard diagnosis by a mean of 14 d and the median time between positive results was shorter than that in other categories of IA. All 13 episodes occurred in the setting of allogeneic HSCT recipients and acute leukaemia. If ‘eligibility’ for antifungal therapy were based on two‐positive‐PCR tests, use of empiric treatment could have been reduced by up to 37%. The nested PCR assay is a practical screening test for excluding IA. Patients with consecutive positive results or intermittent‐positive results (within 14 d) warrant immediate investigations for IA and the initiation of antifungal therapy.
Differential immune effects mediated by Toll‐like receptors stimulation in precursor B‐cell acute lymphoblastic leukaemia
Authors: Corthals Sophie L. , Wynne Kristin , She Kevin , Shimizu Hiromi , Curman Darko , Garbutt Kristy , Reid Gregor S. D.
Published: December 2005

Acute lymphoblastic leukaemia (ALL) is the most common paediatric malignancy and, although current therapy is widely effective, relapse remains a significant clinical problem for which new treatment strategies are required. The ligation of Toll‐like receptors (TLR) on antigen‐presenting cells stimulates the generation of strong T‐cell helper type 1 (Th1) adaptive immune responses. Although TLR9 ligation has been shown to enhance immunogenicity of a number of leukaemia cell types, there have been few reports of the effects mediated through other TLR. In this study we analysed both the expression of TLR by B‐cell precursor ALL cell lines and the effects of individual TLR ligation on the ability of ALL cells to stimulate allogeneic T cells. While ligation of TLR2, TLR 7 and TLR9 led to detectable changes in ALL costimulatory molecule expression, only TLR2 and TLR9 stimulation influenced T‐cell responses. The TLR2 ligand Pam3CysSerLys4 provoked the most significant changes in T‐cell response, dramatically augmenting interferon‐γ production. These results suggest that TLR ligands, in addition to TLR9 agonists, may provide a strategy to enhance the generation of anti‐ALL immune activity by skewing responding T cells towards a Th1 response.
Loss of RanGEF/Pim1 activity abolishes the orchestration of Ran‐mediated mitotic cellular events in S. pombe
Authors: Hirose Eiji , Mukai Mari , Shimada Atsushi , Nishitani Hideo , Shibata Yosaburo , Nishimoto Takeharu
Published: December 2005

RCC1, a conserved chromosomal protein with a seven‐bladed propeller is a GDP/GTP nucleotide exchange factor for RanGTPase that mediates various cellular events. We isolated 16 temperature‐sensitive (ts) mutants of S. pombe RCC1‐homolog, pim1+, by error‐prone PCR. Five pim1ts mutants had a single mutation. The obtained pim1ts mutations and previously reported mutations were localized on similar sites in seven RCC1 repeats. Those mutations resulted in a reduced binding of Pim1 with Spi1. All pim1ts mutants showed a defect in nucleocytoplasmic protein transports, whereas the majority of them showed a normal mRNA export. In all pim1ts examined, chromosomal DNA replication was completed. However, mitotic spindle formation was abrogated, the septum was formed being uncoupled with nuclear division and abnormally widened, thus resulting in chromosomal DNA mis‐segregation and the accumulation of enucleated cells. As a result, a defect of RanGEF/Pim1 abolished the orchestration of sequential mitotic events, spindle formation, septation and cytokinesis that are essential to produce two identical daughter cells.
The stress‐gradient hypothesis does not fit all relationships between plant–plant interactions and abiotic stress: further insights from arid environments
Authors: MAESTRE FERNANDO T. , VALLADARES FERNANDO , REYNOLDS JAMES F.
Published: December 2005

Our earlier meta‐analysis of the effects of abiotic stress on the outcome of plant–plant interactions, suggested that the magnitude of the net effect provided by neighbours, whether positive or negative, was not higher under high abiotic stress conditions. This result, which does not support predictions of the stress‐gradient hypothesis, has been questioned on the basis of limitations in our analytical approach, on the inappropriateness of some of the studies included in our data bases, and on the criteria used to select the levels of abiotic stress within each study. Here we provide additional arguments in defence of our approach and selection of studies, and perform further analyses of our data base that show that these criticisms are not well founded.

The inclusion of studies with contrasting abiotic stress conditions does not invalidate per se tests of predictions derived from the stress‐gradient hypothesis because the hypothesis does not specify that predictions should hold for a given difference, or range of differences, in abiotic stress.

Our re‐analyses show that differences in the length of stress gradient between the low and high stress levels across studies do not reduce the ability of meta‐analysis to test predictions of the stress‐gradient hypothesis, and that our approach does not suffer from ‘hypothesis bias’.

Species interactions across abiotic stress gradients do not follow a simple pattern, and there are specific circumstances under which the predictions arising from the stress‐gradient hypothesis do not hold. This hypothesis requires profound revision if all situations that emerge when evaluating the relationship between plant interactions and abiotic stress are to be ‘fit’ by a single conceptual paradigm.
Long‐term stability and effective population size in North Sea and Baltic Sea cod (Gadus morhua)
Authors: POULSEN NINA Aa. , NIELSEN EINAR E. , SCHIERUP MIKKEL H. , LOESCHCKE VOLKER , GRØNKJÆR PETER
Published: December 2005

DNA from archived otoliths was used to explore the temporal stability of the genetic composition of two cod populations, the Moray Firth (North Sea) sampled in 1965 and 2002, and the Bornholm Basin (Baltic Sea) sampled in 1928 and 1997. We found no significant changes in the allele frequencies for the Moray Firth population, while subtle but significant genetic changes over time were detected for the Bornholm Basin population. Estimates of the effective population size (Ne) generally exceeded 500 for both populations when employing a number of varieties of the temporal genetic method. However, confidence intervals were very wide and Ne's most likely range in the thousands. There was no apparent loss of genetic variability and no evidence of a genetic bottleneck for either of the populations. Calculations of the expected levels of genetic variability under different scenarios of Ne showed that the number of alleles commonly reported at microsatellite loci in Atlantic cod is best explained by Ne's exceeding thousand. Recent fishery‐induced bottlenecks can, however, not be ruled out as an explanation for the apparent discrepancy between high levels of variability and recently reported estimates of Ne << 1000. From life history traits and estimates of survival rates in the wild, we evaluate the compatibility of the species’ biology and extremely low Ne/N ratios. Our data suggest that very small Ne's are not likely to be of general concern for cod populations and, accordingly, most populations do not face any severe threat of losing evolutionary potential due to genetic drift.
The C‐terminal end of LpxC is required for degradation by the FtsH protease
Authors: Führer Frank , Langklotz Sina , Narberhaus Franz
Published: December 2005

Lipopolysaccharide (LPS) biosynthesis is essential in Gram negative bacteria. LpxC, the key enzyme in LPS formation, catalyses the limiting reaction and controls the ratio between LPS and phospholipids. As overproduction of LPS is toxic, the cellular amount of LpxC must be regulated carefully. The membrane‐bound protease FtsH controls the level of LpxC via proteolysis making FtsH the only essential protease of Escherichia coli. We found that the chaperones DnaK and DnaJ co‐purified with LpxC. However, degradation of LpxC was DnaK/J‐independent in contrast to turnover of the heat shock sigma factor σ32 (RpoH). The stability of LpxC in a bacterial one‐hybrid system suggested that a terminus of LpxC might be important for degradation. Different LpxC truncations and extensions were constructed. Removal of at least five amino acids from the C‐terminus abolished degradation by FtsH in vivo. While addition of two aspartic acids to LpxC did not alter its half‐life, the exchange of the last two residues against aspartic acids resulted in stabilization. All stable LpxC enzymes were active in vivo as assayed by their high toxicity. Our data demonstrate that the C‐terminus of LpxC contains a signal sequence necessary for FtsH‐dependent degradation.
A mannan binding lectin is involved in cell–cell attachment in a toxic strain of Microcystis aeruginosa
Authors: Kehr Jan‐Christoph , Zilliges Yvonne , Springer Andreas , Disney Matthew D. , Ratner Daniel D. , Bouchier Christiane , Seeberger Peter H. , De Marsac Nicole Tandeau , Dittmann Elke
Published: December 2005

Microcystin, a hepatotoxin that represents a serious health risk for humans and livestock, is produced by the bloom‐forming cyanobacterium Microcystis aeruginosa in freshwater bodies worldwide. Here we describe the discovery of a lectin, microvirin (MVN), in M. aeruginosa PCC7806 that shares 33% identity with the potent anti‐HIV protein cyanovirin‐N from Nostoc ellipsosporum. Carbohydrate microarrays were employed to demonstrate the high specificity of the protein for high‐mannose structures containing α(1→2) linked mannose residues. Lectin binding analyses and phenotypic characterizations of MVN‐deficient mutants suggest that MVN is involved in cell–cell recognition and cell–cell attachment of Microcystis. A binding partner of MVN was identified in the lipopolysaccharide fraction of M. aeruginosa PCC7806. MVN is differentially expressed in mutants lacking the hepatotoxin microcystin. Additionally, MVN‐deficient mutants contain much lower amounts of microcystin than the wild‐type cells. We discuss a possible functional correlation between microcystin and the lectin and possible implications on Microcystis morphotype formation. This study provides the first experimental evidence that microcystins may have an impact on Microcystis colony formation that is highly important for the competitive advantage of Microcystis over other phytoplankton species.
Sucrose transporter LeSUT1 and LeSUT2 inhibition affects tomato fruit development in different ways
Authors: Hackel Aleksandra , Schauer Nicolas , Carrari Fernando , Fernie Alisdair R. , Grimm Bernhard , Kühn Christina
Published: December 2005

Sucrose transporters of higher plants belong to a large gene family. At least four different sucrose transporters are known in Solanaceous plants, although their function remains to be elucidated in detail. The isolation of LeSUT1 and LeSUT2from Lycopersicon esculentum has been described earlier. Whereas SUT1 is supposed to be the main phloem loader of sucrose in Solanaceae, the role of SUT2 remains a matter of debate. A transgenic approach was taken to evaluate the potential functions of SUT2/SUC3 proteins in sucrose transport or sensing. Expression of LeSUT1 and LeSUT2 was inhibited independently in transgenic tomato plants, using the antisense technique, in order to analyse their specific functions. Although the phloem‐specific inhibition of LeSUT1 antisense plants showed a phenotype consistent with an essential role in phloem loading, constitutive LeSUT2 antisense inhibition exclusively affected tomato fruit and seed development. Neither LeSUT1, nor the LeSUT2 antisense plants were able to produce normal tomato fruits; however, it is likely that independent mechanisms underlie these phenomena. While phloem loading was blocked in LeSUT1 antisense plants, the fertility of fruits was reduced in LeSUT2 antisense plants. A detailed physiological analysis of these plants established a role for SUT2 in pollen tube growth and thus assigned a physiological role for SUT2.
Downregulation of Solanum americanum genes encoding proteinase inhibitor II causes defective seed development
Authors: Sin Suk‐Fong , Yeung Edward C. , Chye Mee‐Len
Published: December 2005

Proteinase inhibitor II proteins (PIN2) are serine proteinase inhibitors found in the Solanaceae. Here, we assign functions in seed development to two Solanum americanum genes, SaPIN2a and SaPIN2b, encoding proteinase inhibitor II. Their mRNAs and proteins have been previously localized to the reproductive tissues, including the inner cell layers of ovules in senescent flowers at the beginning of fruit development, suggestive of their endogenous roles in reproductive development. We have employed RNA interference (RNAi)‐induced post‐transcriptional gene silencing (PTGS) to further investigate the role of SaPIN2a and SaPIN2b during seed development. A SaPIN2a‐derived construct that shared 83% nucleotide homology to SaPIN2b was used in PTGS to silence both genes. Northern blot analyses confirmed that the PIN2–RNAi transgenic plants contain small interfering RNAs (siRNAs) and exhibit reduced levels of SaPIN2a and SaPIN2b mRNAs at various stages of floral development. A reduction in seed set due to seed abortion was observed in PIN2‐RNAi transgenic lines. Cytological and molecular analyses of these lines showed the lack of SaPIN2a and SaPIN2b mRNAs and proteins at the inner cell layers of the ovules in senescent flowers. Aborted seeds in transgenic fruits had an abnormal endothelium. The anomalous expansion of the endothelium prevented proper development of the endosperm and embryo, leading to seed abortion. Our observations indicate that SaPIN2a and SaPIN2b are essential for seed development and suggest that the endothelium may protect the embryo sac, allowing proper formation of the endosperm and embryo, as a result of its ability to produce proteinase inhibitors.
The Arabidopsis heavy metal P‐type ATPase HMA5 interacts with metallochaperones and functions in copper detoxification of roots
Authors: Andrés‐Colás Nuria , Sancenón Vicente , Rodríguez‐Navarro Susana , Mayo Sonia , Thiele Dennis J. , Ecker Joseph R. , Puig Sergi , Peñarrubia Lola
Published: December 2005

Since copper (Cu) is essential in key physiological oxidation reactions, organisms have developed strategies for handling Cu while avoiding its potentially toxic effects. Among the tools that have evolved to cope with Cu is a network of Cu homeostasis factors such as Cu‐transporting P‐type ATPases that play a key role in transmembrane Cu transport. In this work we present the functional characterization of an Arabidopsis Cu‐transporting P‐type ATPase, denoted heavy metal ATPase 5 (HMA5), and its interaction with Arabidopsis metallochaperones. HMA5 is primarily expressed in roots, and is strongly and specifically induced by Cu in whole plants. We have identified and characterized plants carrying two independent T‐DNA insertion alleles, hma5‐1 and hma5‐2. Both mutants are hypersensitive to Cu but not to other metals such as iron, zinc or cadmium. Interestingly, root tips from Cu‐treated hma5 mutants exhibit a wave‐like phenotype at early stages and later on main root growth completely arrests whereas lateral roots emerge near the crown. Accordingly, these lines accumulate Cu in roots to a greater extent than wild‐type plants under Cu excess. Finally, yeast two‐hybrid experiments demonstrate that the metal‐binding domains of HMA5 interact with Arabidopsis ATX1‐like Cu chaperones, and suggest a regulatory role for the plant‐specific domain of the CCH Cu chaperone. Based on these findings, we propose a role for HMA5 in Cu compartmentalization and detoxification.
Analysis of the root‐hair morphogenesis transcriptome reveals the molecular identity of six genes with roles in root‐hair development in Arabidopsis
Authors: Jones Mark A. , Raymond Marjorie J. , Smirnoff Nicholas
Published: December 2005

Root‐hair morphogenesis is a model for studying the genetic regulation of plant cell development, and double‐mutant analyses have revealed a complex genetic network underlying the development of this type of cell. Therefore, to increase knowledge of gene expression in root hairs and to identify new genes involved in root‐hair morphogenesis, the transcriptomes of the root‐hair differentiation zone of wild‐type (WT) plants and a tip‐growth defective root‐hair mutant, rhd2‐1, were compared using Affymetrix ATH1 GeneChips®. A set of 606 genes with significantly greater expression in WT plants defines the ‘root‐hair morphogenesis transcriptome’. Compared with the whole genome, this set is highly enriched in genes known to be involved in root‐hair morphogenesis. The additional gene families and functional groups enriched in the root‐hair morphogenesis transcriptome are cell wall enzymes, hydroxyproline‐rich glycoproteins (extensins) and arabinogalactan proteins, peroxidases, receptor‐like kinases and proteins with predicted glycosylphosphatidylinositol (GPI) anchors. To discover new root‐hair genes, 159 T‐DNA insertion lines identified from the root‐hair morphogenesis transcriptome were screened for defects in root‐hair morphogenesis. This identified knockout mutations in six genes (RHM1–RHM6) that affected root‐hair morphogenesis and that had not previously been identified at the molecular level: At2g03720 (similar to Escherichia coli universal stress protein); At3g54870 (armadillo‐repeat containing kinesin‐related protein); At4g18640 (leucine‐rich repeat receptor‐like kinase subfamily VI); At4g26690 (glycerophosphoryl diester phosphodiesterase‐like GPI‐anchored protein); At5g49270 (COBL9 GPI‐anchored protein) and At5g65090 (inositol‐1,4,5 triphosphate 5‐phosphatase‐like protein). The mutants were transcript null, their root‐hair phenotypes were characterized and complementation testing with uncloned root‐hair genes was performed. The results suggest a role for GPI‐anchored proteins and lipid rafts in root‐hair tip growth because two of these genes (At4g26690 and At5g49270) encode predicted GPI‐anchored proteins likely to be associated with lipid rafts, and several other genes previously shown to be required for root‐hair development also encode proteins associated with sterol‐rich lipid rafts.
ABA‐induced NO generation and stomatal closure in Arabidopsis are dependent on H2O2 synthesis
Authors: Bright Jo , Desikan Radhika , Hancock John T. , Weir Iain S. , Neill Steven J.
Published: December 2005

Nitric oxide (NO) and hydrogen peroxide (H2O2) are key signalling molecules produced in response to various stimuli and involved in a diverse range of plant signal transduction processes. Nitric oxide and H2O2 have been identified as essential components of the complex signalling network inducing stomatal closure in response to the phytohormone abscisic acid (ABA). A close inter‐relationship exists between ABA and the spatial and temporal production and action of both NO and H2O2 in guard cells. This study shows that, in Arabidopsis thaliana guard cells, ABA‐mediated NO generation is in fact dependent on ABA‐induced H2O2 production. Stomatal closure induced by H2O2 is inhibited by the removal of NO with NO scavenger, and both ABA and H2O2 stimulate guard cell NO synthesis. Conversely, NO‐induced stomatal closure does not require H2O2 synthesis nor does NO treatment induce H2O2 production in guard cells. Tungstate inhibition of the NO‐generating enzyme nitrate reductase (NR) attenuates NO production in response to nitrite in vitro and in response to H2O2 and ABA in vivo. Genetic data demonstrate that NR is the major source of NO in guard cells in response to ABA‐mediated H2O2 synthesis. In the NR double mutant nia1, nia2 both ABA and H2O2 fail to induce NO production or stomatal closure, but in the nitric oxide synthase deficient Atnos1 mutant, responses to H2O2 are not impaired. Importantly, we show that in the NADPH oxidase deficient double mutant atrbohD/F, NO synthesis and stomatal closure to ABA are severely reduced, indicating that endogenous H2O2 production induced by ABA is required for NO synthesis. In summary, our physiological and genetic data demonstrate a strong inter‐relationship between ABA, endogenous H2O2 and NO‐induced stomatal closure.
Property Right and Organizational Characteristics of Producer‐owned Firms and Organizational Trust
Authors: James Harvey S. , Sykuta Michael E.
Published: December 2005

Abstract**:  We examine how organizational characteristics of producer‐owned firms are correlated with the level of perceived trust among cooperative members, using survey data from a sample of U.S. agricultural cooperatives. Our results indicate trust is correlated with property right and organizational structures previously identified in the literature as significant for cooperative performance. We find that the norm of equality and the homogeneity of member interests are key correlates of organizational trust in producer‐owned firms. We also find that some property right structures that improve organizational trust are counterproductive for member investment incentives.
Cyclin D1 Protein Expression in Human Thyroid gland and Thyroid Cancer
Authors: Temmim L. , Ebraheem A. K. , Baker H. , Sinowatz F.
Published: December 2005

Cell cycle progression is facilitated by cyclin dependent kinases (CDKs) that are activated by cyclins, including Cyclin D1 and inhibited by CDK inhibitors. Evidence of the involvement of cyclin gene alterations and over expression of various cyclins in human cancer is growing. The role of Cyclin D1 in malignant progression of papillary carcinomas of the thyroid has yet to be established. We therefore studied the expression of Cyclin D1 protein in thyroid carcinomas of young Kuwaiti patients (36 cases of conventional papillary thyroid carcinoma, 12 cases of its follicular variant, one case of tall cell thyroid carcinoma and one case of medullary carcinoma) using immunohistochemistry. In 23 patients (46%) circumscribed areas of cells were detected that showed a distinct to strong nuclear staining for immunoreactive Cyclin D1 whereas the remaining bulk of the carcinoma cells were negative or only showed a slight cytoplasmic staining. None of the tested clinical or path histological parameters showed a statistically significant correlation with the focal immunostaining. This does not rule out that the detected foci with positive nuclear Cyclin D1 immunostaining are areas where a progressive transformation to a more malignant phenotype occurs which eventually leading to lymph node and distant metastases.
Cytochemical Localization of Glycoconjugates in the Secretory Epithelial Cells Lining the Prostate Gland of the Miniature Pig
Authors: Sakairi A. , Tsukise A. , Kuwahara Y. , Nara T. , Meyer W.
Published: December 2005

The aim of the study was to emphasize several specific functional aspects of the mammalian prostate gland. In this connection, the subcellular localization and characterization of glycoconjugates in the secretory epithelial cells were examined that line the prostate gland of the miniature pig, using cytochemistry, including lectin‐gold methods. The results verified a diversified pattern of glycoconjugates in the structures of the secretory cells. The secretory granules and the free surface coat of the plasma membrane contained several sugar moieties such as α‐D‐Man, α‐D‐Glc, α‐L‐Fuc, β‐D‐Gal, GalNAc, GlcNAc and NeuAc (sialic acid), whereas the Golgi apparatus exhibited GlcNAc and sialic acid residues. In addition, the cisterns of the endoplasmic reticulum showed α‐D‐Man and α‐D‐Glc moieties. It seems likely that the secretory glycoconjugates demonstrated contribute to favourable conditions for fertilization.
Differences in Femoral Compact Bone Tissue Microscopic Structure between Adult Cows (Bos taurus) and Pigs (Sus scrofa domestica)
Authors: Martiniaková M. , Grosskopf B. , Vondráková M. , Omelka R. , Fabiš M.
Published: December 2005

The purpose of this investigation was to study in detail compact bone tissue microscopic structure of adult cows and pigs with an emphasis to find an adequate key for the species identification. Altogether 18 femurs were analysed. Each of the bones was sectioned at the smallest breadth of their diaphysis. Specimens were prepared using standard histological equipment, producing thin sections approximately 80–100 μm thick. The qualitative differences between investigated species were examined in anterior, posterior, medial and lateral views of thin sections. The quantitative ones were counted using the specific computer software Scion Image. We measured the area, perimeter, minimal and maximal diameter of the Haversian canals, the Haversian systems and the vascular canals of primary osteons. After that a discriminant function analysis was used for the species identification. According to our results the basic structural pattern of femur diaphysis was primary vascular plexiform in both species. However, non‐vascular bone tissue was identified in cows and resorption lacunae were found between the secondary osteons in pigs. The measured variables of the Haversian canals, the Haversian systems and the primary osteon's vascular canals were higher in most cases in cows. Classification functions for investigated species give a correct classification of 64.69% of cases. This percentage value can be increased by integrating conclusions from the qualitative analysis.
Geography and nursing: convergence in cyberspace?
Authors: Andrews Gavin J. , Kitchin Rob
Published: December 2005

During the last 3 years the interface between geography and nursing has provided fertile ground for research. Not only has a conceptual emphasis on space and place provided nurse researchers with a robust and subtly different way to deconstruct and articulate nursing environments, but also their studies have provided a much needed focus on certain areas of health‐care, and in particular clinical practice, not currently prioritized by health geographers. We argue that, as something that is forcing fundamental re‐considerations of the nature of both nursing and geography, cyberspace is a particularly important phenomenon that lies comparatively under‐researched at this interface. To encourage some interest in researching nursing and cyberspace through a geographical lens, and at least to showcase a range of potentially useful and transportable concepts, we provide an overview of some of the key debates pertaining to cyberspace developed by human geographers, and make some initial and tentative connections to nursing.
Prelude to specialization: US cancer nursing, 1920–50
Authors: Lusk Brigid
Published: December 2005

This study used historical research methodology to assess the work of US nurses caring for patients with cancer from 1920 to 1950. Primary sources, obtained from several US archives, included nursing procedure books, student nurses’ lecture notes, hospital and nursing annual reports, and meeting minutes. Secondary sources included journal articles and textbooks. The aim was to document the clinical work of nurses caring for patients with cancer and assess this work for evidence of emerging specialization in cancer nursing. Following a review of cancer in the 1920s, nursing education specific to cancer, nursing care related to specific cancer therapies, and the practice of concealing a diagnosis of cancer, were examined. Nurses were consistently educated in cancer nursing, but their cancer education became more focused over the decades. Nurses were closely involved with cancer patients as they monitored their patients’ radium or assisted patients following radical surgery. The issue of concealing the diagnosis of cancer was problematic to some nurses. This paper reveals the nature of nurses’ hospital work with cancer patients and demonstrates a core body of cancer nursing knowledge. The emergence of cancer nursing as a specialty is presented.
Utility values and myopia in medical students in Singapore
Authors: Lim Wei‐Yen , Saw Seang‐Mei , Singh Manoj K , Au Eong Kah‐Guan
Published: December 2005

Abstract

Purpose:  Although technologies to correct myopia have progressed in recent years, it is not known how cost‐effective such technologies are. In this paper, utility values of myopic medical students in Singapore were ascertained as a first step to deriving weights for quality adjustment in future cost‐effectiveness studies of such technologies.

Methods:  Students (n = 120) aged 18–22 years with myopia (spherical equivalent at least −0.5 D) from Singapore's sole medical school were recruited. Information on lifetime intention to undergo refractive surgery, contact lens use, proportion of waking time spent wearing corrective devices, and utility values using the time trade‐off and standard gamble for death methods, were obtained.

Results:  The mean utility values for time trade‐off and standard gamble were 0.97 (95% confidence interval 0.96–0.98, median 1.00) and 0.99 (95% confidence interval 0.98–0.99, median 1.00), respectively. Utility values were significantly higher among those who reported a probability of less than 50% that they would undergo refractive surgery within their lifetime, compared with those who reported a probability of 50% or more (means 0.98 vs. 0.95, P < 0.001).

Conclusion:  Utility values in myopic medical students obtained in this study appear to be relatively high, compared with those obtained for other ophthalmic conditions.
Diagnostic vitreous biopsy in patients with uveitis: a useful investigation?
Authors: Manku Harkiran , McCluskey Peter
Published: December 2005

Abstract

Purpose:  To assess whether the results of microbial and cytological investigations of vitreous biopsy specimens are useful in the management of patients with intraocular inflammation.

Method:  A retrospective review of the medical records of 59 consecutive patients from consulting rooms, outpatient clinics and inpatient consultation who underwent intravitreal sampling between January 1997 and December 2003. Results of the biopsies were examined to determine if they altered management of the patient.

Results:  The clinical diagnosis was correct in 37 of 59 patients (62.7%) with ocular inflammation. The organism was identified in 50% (7/14) of vitreous biopsies in patients with postoperative endophthalmitis. Of patients with endogenous bacterial endophthalmitis 16.7% (1/6) had the diagnosis confirmed by vitreous tap and 83.3% (5/6) had positive cultures from other sites that provided the diagnosis. Of the fungal endophthalmitis 80% (4/5) grew the fungus from the vitreous biopsy. Viral polymerase chain reaction identified the causative organism in 87.5% (7/8) of patients with clinical diagnosis of viral infection. 30.8% (4/13) vitreous biopsies in patients with clinically suspected masquerade syndromes were diagnosed as lymphoma. Vitreous biopsy results altered management significantly in seven (11.9%) patients. These patients included toxoplasmosis that was thought to be viral retinitis; malignant melanoma thought to be fungal endophthalmitis; chronic inflammation secondary to retinal detachment that was thought to be a neoplasm; three patients with infective endophthalmitis thought to be idiopathic uveitis and a patient with known lung carcinoma thought to have metastases who had lymphoma. In 67.8% (40/59) the vitreous sample helped to either confirm the diagnosis or exclude an infective cause. Complications from vitrectomy were hypotony (1/29) and retinal detachment (1/29).

Conclusion:  Clinical diagnosis based on examination findings and vitreous biopsy is highly accurate. Vitreous sampling altered the management of seven of 59 patients. Vitreous biopsy is a safe and useful method for diagnosing and excluding malignancy and infection in patients with ocular inflammation. Viral polymerase chain reaction is highly sensitive and accurate. The sensitivity of microbiological culture techniques for bacteria and fungi limits their usefulness.
Bilateral exudative retinal detachments as the presenting features of idiopathic orbital inflammation
Authors: Yuen Kenneth SC , Lai Connie HY , Chan Wai‐Man , Lam Dennis SC
Published: December 2005

Abstract

Idiopathic orbital inflammation, also known as orbital pseudotumour, is a term describing a spectrum of idiopathic, non‐neoplastic, non‐infectious, space‐occupying orbital lesion without identifiable local or systemic cause. This disease occurs mainly in young adults and typically presents with acute proptosis, chemosis and limited extraocular movement. Herein an unusual case of idiopathic orbital inflammation presenting with bilateral exudative retinal detachment in a 9‐year‐old girl is described. It demonstrates that prompt diagnosis and corticosteroid treatment can yield good clinical response and significant visual recovery.
Centennial review of corneal transplantation
Authors: Moffatt S Louise , Cartwright Victoria A , Stumpf Thomas H
Published: December 2005

Abstract

One hundred years ago, on 7 December 1905, Dr Eduard Zirm performed the world's first successful human corneal transplant. This significant milestone was achieved only after many decades of unsuccessful trial and error; however, it did not lead to relatively ‘routine’ keratoplasty success for several more decades. The idea of replacing an opaque cornea had been suggested for centuries, and had stimulated theoretical approaches to the problem by many esteemed physicians throughout history. However, little practical progress was made in the ultimate realization of the dream until the 19th century when pioneering surgeons pursued extensive studies in relation to both animal and human ‘keratoplasty’. Clinical progress and scientific insight developed slowly, and it was ultimately due to parallel advances in medicine such as anaesthesia and antisepsis that Zirm's success was finally achieved. Key concepts were enshrined such as the use of fresh tissue from the same species, careful placement and handling of tissue, and the development of specialized instrumentation such as the circular trephine. In the latter half of the 20th century, many ‘masters’ of corneal surgery evolved significant refinements in technique and instrumentation with the development of corticosteroids, antibiotics, surgical microscopes, improved trephines, viscoelastics and suture materials, that enable this delicate procedure to be routinely performed with the prospect of success. There are still limitations to corneal transplantation, and corneal allograft rejection still poses the greatest challenge to the modern corneal surgeon. In the foreseeable future it may be in the laboratory, rather than the theatre, that further milestones will be achieved. This review aims to highlight the significant milestones in the rich history of corneal transplantation, and to pay tribute to the many inspired and dedicated individuals involved in the development of keratoplasty to a point where the procedure is now a standard tool in the repertoire of ophthalmic surgery and more than a million people have enjoyed restoration of useful sight.
Down‐regulation of metabotropic glutamate receptor 1α in globus pallidus and substantia nigra of parkinsonian monkeys
Authors: Kaneda K. , Tachibana Y. , Imanishi M. , Kita H. , Shigemoto R. , Nambu A. , Takada M.
Published: December 2005

Enhanced glutamatergic neurotransmission via the subthalamopallidal or subthalamonigral projection seems crucial for developing parkinsonian motor signs. In the present study, the possible changes in the expression of metabotropic glutamate receptors (mGluRs) were examined in the basal ganglia of a primate model for Parkinson's disease. When the patterns of immunohistochemical localization of mGluRs in monkeys administered systemically with 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) were analysed in comparison with normal controls, we found that expression of mGluR1α, but not of other subtypes, was significantly reduced in the internal and external segments of the globus pallidus and the substantia nigra pars reticulata. To elucidate the functional role of mGluR1 in the control of pallidal neuron activity, extracellular unit recordings combined with intrapallidal microinjections of mGluR1‐related agents were then performed in normal and parkinsonian monkeys. In normal awake conditions, the spontaneous firing rates of neurons in the pallidal complex were increased by DHPG, a selective agonist of group I mGluRs, whereas they were decreased by AIDA, a selective antagonist of group I mGluRs, or LY367385, a selective antagonist of mGluR1. These electrophysiological data strongly indicate that the excitatory mechanism of pallidal neurons by glutamate is mediated at least partly through mGluR1. The effects of the mGluR1‐related agents on neuronal firing in the internal pallidal segment became rather obscure after MPTP treatment. Our results suggest that the specific down‐regulation of pallidal and nigral mGluR1α in the parkinsonian state may exert a compensatory action to reverse the overactivity of the subthalamic nucleus‐derived glutamatergic input that is generated in the disease.
Chondroitinase ABC combined with neural stem/progenitor cell transplantation enhances graft cell migration and outgrowth of growth‐associated protein‐43‐positive fibers after rat spinal cord injury
Authors: Ikegami Takeshi , Nakamura Masaya , Yamane Junichi , Katoh Hiroyuki , Okada Seiji , Iwanami Akio , Watanabe Kota , Ishii Ken , Kato Fumikazu , Fujita Hiroshi , Takahashi Toyomi , Okano Hirotaka James , Toyama Yoshiaki , Okano Hideyuki
Published: December 2005

We previously reported that the transplantation of neural stem/progenitor cells (NSPCs) can contribute to the repair of injured spinal cord in adult rats and monkeys. In some cases, however, most of the transplanted cells adhered to the cavity wall and failed to migrate and integrate into the host spinal cord. In this study we focused on chondroitin sulfate proteoglycan (CSPG), a known constituent of glial scars that is strongly expressed after spinal cord injury (SCI), as a putative inhibitor of NSPC migration in vivo. We hypothesized that the digestion of CSPG by chondroitinase ABC (C‐ABC) might promote the migration of transplanted cells and neurite outgrowth after SCI. An in vitro study revealed that the migration of NSPC‐derived cells was inhibited by CSPG and that this inhibitory effect was attenuated by C‐ABC pre‐treatment. Consistently, an in vivo study of C‐ABC treatment combined with NSPC transplantation into injured spinal cord revealed that C‐ABC pre‐treatment promoted the migration of the transplanted cells, whereas CSPG‐immunopositive scar tissue around the lesion cavity prevented their migration into the host spinal cord in the absence of C‐ABC pre‐treatment. Furthermore, this combined treatment significantly induced the outgrowth of a greater number of growth‐associated protein‐43‐positive fibers at the lesion epicentre, compared with NSPC transplantation alone. These findings suggested that the application of C‐ABC enhanced the benefits of NSPC transplantation for SCI by reducing the inhibitory effects of the glial scar, indicating that this combined treatment may be a promising strategy for the regeneration of injured spinal cord.
Effects of M‐current modulators on the excitability of immature rat spinal sensory and motor neurones
Authors: Rivera‐Arconada I. , Lopez‐Garcia J. A.
Published: December 2005

M‐currents have been shown to control neuronal excitability in a variety of central and peripheral neurones. Here we studied the effects of specific M‐current modulators on the excitability of spinal neurones and their response to synaptic activation. Experiments were performedin vitrousing the hemisected spinal cord from 7‐ to 11‐day‐old rats. Intracellular recordings were obtained from lumbar deep dorsal horn and motor neurones. Neuronal excitability was assessed by applying outward current pulses and synaptic responses were elicited by activation of a lumbar dorsal root. The M‐current antagonist 10,10‐bis(4‐pyridinylmethyl)‐9(10H)‐anthracenone (XE‐991) and the agonist retigabine were superfused at 10 µm. Retigabine produced hyperpolarization and a large decrease in the excitability of motor (7/7) and dorsal horn neurones (11/12). The effects of retigabine were fully reversed by XE‐991. XE‐991 induced depolarization of most neurones tested and a large increase in the excitability of motor neurones (7/7) but only a weak increase in the excitability of a proportion of dorsal horn neurones (4/10). The effects of XE‐991 were partly reversed by retigabine. Consistent with their effects on neuronal excitability, retigabine showed a general depressant effect on synaptic transmission, whereas XE‐991 showed the opposite tendency to potentiate responses to dorsal root stimulation, particularly in motor neurones. The results show that retigabine can depress spinal excitability and the transmission of nociceptive information. Results also indicate a post‐synaptic expression of functional M‐currents in most motor neurones and a considerable proportion of deep dorsal horn neurones.
Cardiovascular effects of noradrenaline microinjected into the dorsal periaqueductal gray area of unanaesthetized rats
Authors: Pelosi Gislaine Garcia , Corrêa Fernando Morgan Aguiar
Published: December 2005

The periaqueductal grey area (PAG) is a mesencephalic region that is involved in the modulation of cardiovascular changes associated with behavioural responses. Among the neurotransmitters present in the PAG, noradrenaline (NA) is also known to be involved in central nervous system cardiovascular regulation. In the present study we report the cardiovascular effects of the microinjection of NA into the dorsal portion of the PAG (dPAG) of unanaesthetized rats and the peripheral mechanism involved in their mediation. Injection of NA in the dPAG of unanaesthetized rats evoked a dose‐dependent pressor response accompanied by bradycardia. The magnitude of the pressor responses was higher at more rostral sites in the dPAG and decreased when NA was injected into the caudal portion of the dPAG. The responses to NA were markedly reduced in urethane‐anaesthetized rats. The pressor response was potentiated by i.v. pretreatment with the ganglion blocker pentolinium and blocked by i.v. pretreatment with the vasopressin antagonist dTyr(CH2)5(Me)AVP. The results suggest that activation of noradrenergic receptors within the dPAG can evoke pressor responses, which are mediated by acute vasopressin release.
Alterations of arcuate nucleus neuropeptidergic development in contactin‐deficient mice: comparison with anorexia and food‐deprived mice
Authors: Fetissov Sergueï O. , Bergström Ulrika , Johansen Jeanette E. , Hökfelt Tomas , Schalling Martin , Ranscht Barbara
Published: December 2005

A mutation in the Contactin‐1 gene results in an ataxic and anorectic phenotype that is apparent by postnatal day 10 and lethal by postnatal day 19 [Berglund et al. (1999)Neuron 24, 739–750]. The resemblance of this phenotype with the anorexia (anx/anx) mouse mutation prompted us to investigate the hypothalamic neurochemistry of Contactin knock‐out (KO) mice. Contactin was expressed in the hypothalamic neuropil of wild‐type (WT) but not Contactin KO mice. In the KO condition, neuropeptide Y (NPY) and agouti‐related protein (AgRP) immunoreactivity (IR) accumulated in the somata of arcuate nucleus neurons, whereas IR for these neuropeptides as well as for α‐melanocyte‐stimulating hormone (α‐MSH) decreased in the corresponding axon projections. These changes in the pattern of neuropeptide expression in the Contactin‐deficient hypothalamus were similar but more pronounced than those found in anx/anx mice. Increased levels of NPY and AgRP and decreased concentrations of pro‐opiomelanocortin mRNA in arcuate neurons accompanied these changes. In relating these alterations a 24‐h food deprivation period, we observed in 3‐week‐old WT mice an elevation of NPY‐ and AgRP‐IR in the perikarya of arcuate neurons without notable reduction of NPY‐ or AgRP‐IR in nerve fibers, suggesting that the decrease of arcuate projections can be associated with postnatal anorectic phenotype. Our data implicate Contactin in the postnatal development of the NPY/AgRP and α‐MSH arcuate neurons and suggest that similar to anx/anx mutant mice, compromised orexigenic signaling via NPY/AgRP neurons may contribute to reduced food intake by the Contactin‐mutant animals.